The Virus

The family Astroviridae encompasses small nonenveloped viruses that infect a variety of animal species. They were originally classified among the small round structured viruses (SRSV) causing diarrhea in humans. They are round with icosahedral symmetry and 27-30 nm in diameter. They were first described by Madeley and Cosgrove 1 as a potential cause of diarrheal disease in human infants and named for the characteristic five- or six-pointed star (astron is Greek for a star), visible on the...

Multiplex Nasba And

Greijer et al. 5 designed a multiplex real-time NASBA using molecular beacon probes labeled with three different fluorophores to quantify human cytomegalovirus (CMV) IE1 mRNA by competitive coamplification of wild-type and calibrator RNA. A simultaneous detection of late pp67mRNA in whole-blood samples of CMV-infected lung transplant patients was also obtained. Despite the somewhat lower sensitivity of the real-time NASBA compared with the conventional NASBA, the simultaneous quantification of...

Retargeting Of Adenoviral Vectors

The adenovirus contains a protein capsid with protruding fibers. These fiber proteins form a trimer and the C-terminal region of these fibers is called the fiber knob. The fiber knob recognizes and binds to the host cell via the coxsackievirus-adenovirus receptor (CAR), which is present on many cell types. Upon binding to CAR, secondary interactions between the adenovirus and cell surface receptors cause the internalization of the adeno-virus. By shielding or modifying the fiber of the...

Overview Technical Description

Ramification amplification (RAM), 1,2 also termed hyperbranched rolling circle amplification1-3-1 or cascade rolling circle amplification,1-4-1 utilizes a closed C-probe or padlock probe and a DNA polymerase under isothermal conditions. The choice of DNA polymerase is based on the following requirements a good strand displacement activity in order to separate downstream DNA from the template strand and a high processivity (i.e., incorporating nucleotides continuously on a given primer without...

Tobacco Related Diseases

GSTM1 and GSTT1 have been particularly studied as risk candidates for tobacco-related cancers. 14,15 While some studies show significantly increased risk for GSTM1*0 and GSTT1*0 homozygotes, others have not replicated these findings prompting the use of meta-analysis. For example, analysis using 43 studies indicates that GSTM1 null is not associated with increased lung cancer risk and that there is no evidence for an interactive effect between the genotype and tobacco consumption.1-15-1...

Nat And Disease

The role of NATs in human disease has recently been extensively reviewed. 3 The following is a summation of findings to date. The association between acetylator status and the risk of various diseases has been extensively reported. Altered risk with either the slow or rapid phenotype has been observed for bladder, colon and breast cancer, systemic lupus erythematosis, diabetes, age-related cataracts, Gilbert's disease, Parkinson's disease, and Alzheimer's disease. These associations imply a...

Clinical Features

Haas 4 provided the first clinical description of the disease in 1898. The phenotype of RS and its variability have been described by several authors. 5-8 The predominant phenotype includes foveal and peripheral retinoschisis and vitreous veils of partial retinal layers in the vitreous. Fundus examination may show the Mizuo phenomenon, an inner retinal sheen that occurs with the onset of light exposure after a period of dark adaptation. 9 An area of schisis may leave a retinal vessel...

Practical RCA formats

Generally, the RCA-based diagnostics can be classified into two groups some of them operate with the preformed circular probes Fig. 1D and E for the peptide nucleic acid (PNA)-assisted, nick-induced RCA and immuno-RCA, Fig. 1 Schematics of different RCA processes the arrowhead symbolizes the DNA polymerase. Given a small, < 100-nt size of DNA minicircles used in RCA and the strong rigidity of dsDNA fragments with these lengths, only part of the circular probe can be base-paired at any given...

Pathophysiologic And Genetic Features

The first step in the telangiectasia formation consists a focal dilatation of postcapillary venules with predominant stress fibers in pericytes along the luminal border. As the venules enlarge, they become convoluted and form excessive layers of smooth muscle cells without elastic fibers and connect directly with the dilated arterioles.1-1-1 The molecular basis consists of a defect of the TGF-p signaling pathway which, in normal conditions, plays an important role in vascular remodeling and...

Conclusion Genomics And Vaccination

Despite the advances associated with molecular techniques, meningococcal disease remains a globally significant health problem, and the prospect of comprehensive vaccination remains elusive. Whereas vaccines based on the capsular polysaccharide are either licensed or under development against meningococci associated with serogroups A, C, and Y, as well as W-135, attempts to develop a polysaccharide-based serogroup B vaccine have proven unsuccessful. This fact is especially relevant as much of...

Principles Of Rna Storage

Basically, RNA can be stored in purified form after its extraction or synthesis, or unprocessed samples containing the RNA of interest are stored. However, even in the latter case, proper care must be taken to avoid (re) contamination of RNA with RNases once it is extracted from the stored sample. Little information is available on the long-term stability of isolated and purified RNA during storage. Most studies have been carried out focusing on various storage conditions of unprocessed samples...

Principle Of The Taqman Assay

Like several eubacterial DNA polymerases, Thermus aquaticus (Taq) polymerase is a bifunctional enzyme consisting of a polymerization domain and a nuclease domain, and it is the latter that is crucial for the TaqMan assay. 1 In essence, the TaqMan assay is identical to a standard PCR reaction powered by Taq polymerase, except for the addition of the TaqMan probe, a nonextendable fluorescently labeled oligonucleotide hy bridizing on the target DNA between the forward and reverse primers 2-3 (Fig....

Sample Preparation for PFGE

Standard sample preparation procedures for DNA isolation involving mechanical forces are inappropriate for the analysis of fragile, high-molecular weight DNA molecules that easily break into small pieces. To prevent DNA damage, intact cells mixed with warmed, liquid agarose are pipetted into plug molds, 10 x 5 x 1.5 mm in size. Cells embedded in the agarose plugs are lysed in situ by detergents and enzymes. The agarose matrix keeps the large DNA molecules intact, while permitting diffusion of...

Kras

Associated malignancies and their penetrance Associated malignancies and their penetrance Gastric cancer (70 ) Lobular breast cancer in females (39 ) Colorectal cancer (70-85 ) Endometrial cancer (40-60 ) Ovarian cancer (12 ) Stomach, uroepithelial, hepatobiliary, brain, small bowel cancers Colorectal cancer Ovarian stromal tumors Uterine and cervical cancer Gastrointestinal tract polyposis and cancers, breast and testis, cancers Thyroid cancer Breast cancer Gastric cancer Leukemia Breast...

Principles Of Qfish

As stated above, Q-FISH requires the use of fluorescently labeled telomeric PNA probes. The most commonly used probe is Cy3-labeled (CCCTAA)3. Following hybridization of this probe with the metaphase chromosome preparations, high stringency washes are performed to eliminate background fluorescence that may interfere with the quantitation of telomere fluorescence. Separate images of metaphase chromosomes and telomeres are then acquired using appropriate image-acquisition software packages and...

Dominantly Inherited PD

Golbe et al. 7 described the first large kindred of autosomal dominant PD with autopsy verification in 1990 and later reported a clinical genetic analysis of 60 individuals in five generations. The kindred originated from Contursi, a hill town in the Salerno province of the southcentral region of Italy. There was severe neuronal loss and Lewy bodies in the substantia nigra, typical of PD. Mean age at onset was 46.5 years 15 years younger than that of PD in the community and the disease had a...

The Fish Technique

Fish Labelled Probes

The FISH technique is based on the ability of single-stranded DNA to anneal to complementary DNA. In the case of FISH, the target DNA is the nuclear DNA of interphase cells or the DNA of metaphase chromosomes that are affixed to a glass microscope slide. FISH can be accomplished with bone marrow or peripheral blood smears, or other fixed tissue, and modifications of FISH methodology have also permitted the analysis of nuclei extracted from paraffin-embedded tissues or frozen sections from solid...

Ar

Partial loss or complete skipping of exon 6 Procollagen-N-proteinase ADAMTS-2 gene Molecular screening for mutations in COL5A1 or COL5A2 Not available Biochemical analysis of type III collagen by SDS-PAGE Molecular screening for mutations in COL3A1 Increased ratio deoxypyridoline to pyridoline cross-links in urine by HPLC Measurement of lysyl hydroxylase-1 activity Molecular screening of PLOD1 gene Biochemical analysis of type I collagen by SDS-PAGE Detection of complete or partial skipping of...

Genotype To Phenotype Correlations

In 1930, Wolff, Parkinson, and White 1 described patients with electrocardiograms showing a short PR interval, a delta wave, and a wide QRS complex. It was postulated an accessory atrial ventricular pathway would explain the particular ECG and the recurrent tachycardias. Electro-physiological investigations, cardiac electrical mapping, surgical findings, anatomic studies, and results of ablation treatment have confirmed the presence of accessory conduction pathways (Fig. 1). The normal cardiac...

Snp Analysis In Coding And Noncoding Dna Regions

Within the chromosomal DNA, SNPs are highly abundant occurring on average 1 base in every 1000. 11,12 As the human genome is now known to be around 3 billion bases Fig. 2 Analysis of two SNP loci on the human mitochondrial genome. (Taken from research work by Dr. Barbara Llewellyn at the University of Strathclyde.) The top panel shows the results of hybridization of a segment of DNA mitochondrial DNA to oligonucleotide sequences on a silicone chip. The position on the chip where the DNA binds...

Consequences of Immune System Cells Stimulation by Superantigens

The excessive activation of an unusual high proportion of T lymphocytes and APCs in vivo and in vitro upon binding the SAg molecules triggers massive production of a wide array of inflammatory and other Th1 Th2 and APC-derived cytokines, by the stimulated cells. This process takes place through a complex of upregulated and downregulated immunological networks, activation signals, and the cooperation of adhesion molecules on target cells leading to a cascade of events including further release...

Herpes Simplex Resistance History

Acyclovir (ACV) is the gold standard for the treatment of HSV infections. This drug is a nucleoside analogue of guanosine that has to be phosphorylated three times. The first phosphorylation is achieved by the thymidine kinase (TK) encoded by the virus this step is important as it allows ACV to become active only in infected cells. The second and third phosphorylations are carried out by cellular thymidylate kinases. Acyclovir triphosphate is a competitive inhibitor of viral DNA polymerase and...

FISH for Aneuploidy Screening

Cytogenetic studies have shown that up to 60 of the early spontaneous abortions in humans are caused by numerical chromosomal abnormalities and that as many as 70 of all human preimplantation embryos may contain aneuploid cells. 5 This prompted the development of PGD for aneuploidy screening of oocytes and preimplantation embryos (PGD-AS). Fluorescent in situ hybridization is Fig. 2 Polar body biopsy. Removal of the first and second polar body. Fig. 2 Polar body biopsy. Removal of the first and...

Info

The TMA has been divided into four subsections to facilitate navigation during microscopy. 2. Taking a cylindrical sample from the tissue sample (donor) paraffin block. 3. Placing the cylindrical tissue sample in the premade hole in the recipient block. Commercially available or various kinds of homemade tissue-arraying systems are used for TMA manufacturing. Exact positioning of the tip of the tissue cylinder at the level of the recipient block surface is crucial...

Single Molecule Sensors

All DNA biosensors discussed so far use DNA as the biological recognition probe to obtain specificity. Several novel methods use nonspecific proteins such as ion channels or enzymes to detect sequence information from single molecules of DNA. The most commonly employed ion channel is the a-hemolysin ion channel reconstituted in an artificial bilayer. Using a 120-mV applied potential, the channel samples unlabeled DNA from solution. Capture of a DNA molecule is observed as an ionic current...

Familial Adenomatous Polyposis Syndrome

Familial adenomatous polyposis syndrome is characterized by accelerated tumorigenesis from normal mucosa to polyps. It occurs in 1 8000 to 1 13,000 live births and shows no racial, gender, or geographical predilection. It has autosomal dominant inheritance with 100 pene-trance, and if left untreated, patients affected with FAP will inevitably develop colorectal cancer, typically by the age of 35-40 (mean age 39 years). 1 It accounts for about 1 of all colorectal cancers. Approximately 15 , 75 ,...

Heteroduplex Analysis Matrices

At its earliest inception, the sensitivity of HA was limited by the availability of suitable gel matrices. Slab-gel systems are limited to agarose and polyacrylamide. The improved MDE gel solution (Cambrex) is a polyacryl-amide-like matrix with a high sensitivity for DNA conformational changes. The gel's unique structure allows DNA separation on the basis of both size and conformation, thus increasing the probability of detecting sequence differences from as low as 15 achieved in standard...

X

Fig. 3 Microarray-CGH profile of BT474 cell line (test), reference normal kidney DNA (A), oligonucleotides as probe DNAs spotted on the glass slide moving average applied to the log2 ratio (B), BAC PAC PCR representations as probe DNAs spotted on the glass slide. Vertical bars indicate spacing between chromosomes. (View this art in color at www.dekker.com.) oncogene mapping to the amplified region at 20q13.2 in breast tumors. 26 This amplicon was also analyzed in stomach tumors by array-CGH, as...

Volume

Accreditation of the Medical Laboratory ISO 15189 ISO 17025 Mario Plebani 1 ACE Genotyping Michael Rudnicki and Gert Actinomyces spp. Val Hall Acute Myeloid Leukemia (AML) Cytogenetic Detection of Selected Recurrent Chromosomal Abnormalities Hon Fong L. Mark, Robert A. Sokolic, and Yvonne Adeno-Associated Viral Vectors Barrie J. Adenoviral Gene Therapy Willemijn M. Gommans, Hidde J. Haisma, and Marianne G. Rots Alagille Syndrome Michelle Hadchouel and Michele Allele-Specific Oligonucleotide...

Therapy of Infections

Vancomycin is the first-line antibiotic used for the treatment of infections caused by MRSA. Newer agents with in vitro and in vivo efficacy against MRSA include Table 1 Oligonucleotides used for conventional multiplex PCR Nucleotide sequence (5' to 3') of primer (F forward, R reverse) mecA (X52593) F primer TGG CTA TCG TGT CAC AAT CG R primer CTG GAA CTT GTT GAG CAG AG nuc (V01281) F primer GCG ATT GAT GGT GAT ACG GTT R primer AGC CAA GCC TTG ACG AAC TAA AGC femA (X17688) F primer CTT ACT TAC...

Singlecell Fish Analysis

Preimplantation genetic diagnosis for the age-related aneuploidies is currently performed by FISH analysis using commercially available chromosome-specific probes (Abbott, Downers Groves, IL). It was first applied in 1991 for gender determination using DNA probes specific either for the X or Y chromosome. 9 Because testing for only one of the sex chromosomes could lead to misdiagnosis of gender because of a possible failure of hybridization, a dual FISH was introduced, involving the...

Repertoire And Biochemistry Of S Pyogenes Superantigens

The repertoire of S. pyogenes SAgs includes 11 structurally and functionally related, single-chain proteins with molecular weights ranging from ca. 23 to 27 kDa. 14 Most of these proteins have been purified to homogeneity. The repertoire comprises 1) the classical erythrogenic (scarlatinal) toxins A and C (due to their likely association with scarlet fever), also designated streptococcal pyrogenic exotoxins A and C (SPE A, SPE C) 2) a series of recently discovered mitogenic exoproteins, called...

References

Nucleic acid based tests move slowly into clinical labs. Am. Soc. Microbiol. News 2001, 67, 560565. 2. Mackay, I.M. Real-time PCR in the microbiology laboratory. Clin. Microbiol. Infect. 2004, 10, 190-212. 3. Kricka, L.J. Microchips, microarrays, biochips and nano-chips Personal laboratories for the 21st century. Clin. Chim. Acta 2001, 307, 219-223. 4. St-Louis, P. Status of point of care testing Promise, realities and possibilities. Clin. Biochem. 2000, 33, 427440. 5. O'Brien, J.A....

Procedures For Msms Screening

Specimen preparation for MS-MS screening requires an extraction and derivatization process, 3 which is performed using 96-well polypropylene microplates in routine analysis. 4-6 One 3.2-mm disk of dried blood spot is punched out into the individual wells of a microplate. To the disk in each well, a methanol solution containing known concentrations of stable isotope-labeled standards is added. The microplate is covered and the samples are mixed. The extract is transferred to a second microplate...

Outline Of The Method

The comet assay can be conducted on virtually any nucleated cell that can be brought into suspension. Thus, both cultured or freshly isolated cells from any organ can be used. Isolating cells from solid tissues usually involves time-consuming procedures, often implying the use of extracellular matrix-digesting enzymes, which can damage DNA. Instead, for the study of endogenous levels of DNA damage, it is necessary to use rapid isolation techniques to reduce the onset of artefacts, and, for some...

Molecular Genetic Pathogenesis

For many years, RS was thought to be a result of a defect in the Muller cell that acted as a cellular scaffold within the retinal architecture. Recent studies on gene expression and immunolocalization of retinoschisin indicate that it is expressed in all major classes of adult retinal neural cells, with the possible exception of horizontal cells, and that there is no retinoschisin detected in Muller cells or processes, 22 although this is reported by others. 33,34 RS is abundantly expressed in...

Mitochondrial Dna And Forensic Science

The current situation in forensic science is that there are a number of autosomal STR loci that can be analyzed leading to possible links between a crime scene sample and that taken from a suspect. Mitochondrial DNA has been used in forensic science for human identification and Single Nucleotide Polymorphisms SNPS Single Nucleotide Polymorphisms SNPS Fig. 1 Example of minisequencing of 12 SNP sites on the human mitochondrial genome. Panel 1 shows a DNA sequence trace from four samples of...

Management

Replacement of factor IX is essential for the prevention and treatment of hemorrhage in hemophilia B. Earlier forms of replacement therapy were crude preparations of donated plasma that were often only partially effective. The production of highly concentrated factor IX preparations had a major impact in the management of hemophilia B, facilitating home therapy, early treatment of bleeds, amelioration of joint damage, and a marked improvement in quality of life. However, their use was...

Introduction

Glycogen storage diseases (GSDs) are inherited disorders affecting glycogen metabolism. The glycogen found in GSDs is abnormal either in quantity or quality. Liver and muscle are the most common and seriously affected tissues. The liver GSDs usually present with hepatomegaly and hypoglycemia. The GSDs primarily affecting the liver are types I, III, IV, VI, and IX. The most common features of muscle GSDs are muscle cramps, exercise intolerance, fatigue, and progressive weakness. GSDs principally...

Immunotherapy

Immune responses to infection are vital as evidenced by the fact that healthy, immunocompetent individuals resolve infection. An interesting correlation between administration of highly active antiretroviral therapy (HAART) and a decrease in cryptosporidiosis in AIDS patients has been observed. HAART does not directly affect the parasite but exerts its effects through enhancing the immune system of these patients. A picture is slowly emerging of the immune responses during infection. CD4+ T...

Genetic Bases Of Long Qt Syndrome

The discovery of the genetic basis of LQTS started in the early 1990s with the mapping of four LQTS loci on chromosomes 11, 3, 7, and 4 5 (OMIM IDs 192500, 152427, 603830, 600919) (Table 1). Subsequently, the gene on chromosome 11 (LQT1) was identified as KCNQ1 by Wang et al. 6 using positional cloning whereas the candidate gene approach led to the identification of KCNH2 and SCN5A as the genes on chromosomes 7 (LQT2) and 3 (LQT3). 7,8 More recently, mutations in two additional genes on...

Gene Mapping Studies

Southern analysis was used to map the FSHD locus to chromosome 4q35 2,3 by using probe p13E-11 derived from the complex locus D4F104S1. 3 Indeed, the FSHD locus is closely linked to the locus D4F104S1 (Fig. 1). However, there are some evidence of genetic heterogeneity in FSHD because about 5 of families manifest an inherited pattern that is unlinked to 4q35. A provisional linkage to chromosome 15 has been suggested, but the gene still remains to be identified.

Future Of Personalized Medicine

Future medicine will be practiced in an environment in which molecular classification of diseases based on genomic analysis will replace the one based on symptoms. Molecular diagnostics to predict the results of therapy will be based on patient's genomic profile. There is still a considerable amount of work to be done before personalized medicine is established in clinical practice. Enables the monitoring of viral load and detection of resistance to treatment in personalized protocols for...

Frequency Of Resistance

Generally in S. pneumoniae, parC mutations are observed alone in isolates with low-resistance MICs (ciprofloxacin MIC 4 mg mL). As the MICs increase, isolates usually have mutations in both parC and gyrA. The presence of resistance mutations (in ParC, GyrA, and ParC and GyrA) and active efflux based on ciprofloxacin MICs is demonstrated in Fig. 1. The most common mutation in ParC is Ser-79-Phe. 1,10 Of all isolates with a ParC 4ug mL 8ug mL 16ug mL 32ug mL 64ug mL (n 36) (n 15) (n 9) (n 14) (n...

Fiber Optic Sensors

Fiber-optic biosensors use total internal reflectance to measure fluorescent-labeled targets captured at the glass fiber surface. Fibers have been configured for use in large or small clusters. Large clusters of 6000 fibers are used in an array format with probe-coated beads seated at the tip of each fiber (Illumina, San Diego, CA.). With this system, Epstein and colleagues 12 showed that zeptomole levels of fluoroscene-labeled 21-mer containing the cystic fibrosis F508C mutation could be...

Extracellular Fetal Dna Clinical Applications

The discovery of cell-free fetal DNA quickly led to a clinical application, namely the determination of the fetal RhD genotype in pregnancies at risk for hemolytic disease of the fetus and newborn (HDN). 10 This is largely because of the fortunate constellation existing in Caucasians where the RhD gene is generally absent in RhD individuals. Therefore the analysis of the fetal RhD genotype in pregnancies with an RhD constellation (father RhD, mother RhD) is similar to the facile detection of Y...

Evidence Examination

Irrespective of possible chain of custody rules, examination of evidence starts with photographic and or drawn descriptions of the items received by the forensic biologist. In every photograph, an absolute scale must be visible (millimeters centimeters no pennies, no matches). Resolution should be > 2816 x 2112 pixels 4 MPixel to allow blowing up of the pictures. Flash light should be avoided because brighter parts of the objects will flash out (become white a digital artefact). Biological...

Duplications Of Proximal 15q

The region of chromosome 15q11-13 has long been known to be chromosomally unstable, being the site of deletions, duplications, triplications, translocations, inversions, and the breakpoints for supernumerary chromosomes. The resulting phenotype of such rearrangements is further complicated by the abundance of imprinted genes in the region. Thus, paternal deletions of the region result in Prader-Willi syndrome (PWS), whereas maternal duplications of the exact same region cause the...

Discussion

Fetal DNA has been known to be present in maternal blood since the work of Lo et al. 9 in 1997. They first showed that Y-chromosomal sequences could be amplified from DNA isolated from the plasma of pregnant women carrying a male fetus. Fetal DNA is present in maternal serum at 5 weeks' gestation 10 and the concentration of fetal DNA increases with gesta-tional age. Fetal DNA represents 3.4 (0.4-12 ) and 6.2 (2.3-11.5 ) of total plasma DNA in the first and third trimesters of pregnancy,...

Detection Of Homoplasmic And Heteroplasmic Mutations In Mitochondrial Genome

Energy metabolism disorders caused by mutations in mtDNA represents a group of heterogeneous diseases. The most frequently found mtDNA point mutations are A3243G for mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), A8344G for myoclonus epilepsy, ragged red fibers (MERRF), T8993G C for neuropathy, ataxia, retinitis pigmentosa (NARP), and Leigh syndrome, and G11778A for Leber's hereditary optic neuropathy (LHON). 16,22 Molecular analysis of the known...

MagNA Pure Lc Instrument

Magnetism is the underlying principle of the automated nucleic acid isolation performed by the MagNA Pure system (Roche Diagnostics, Mannheim, Germany). The instrument has a completely closed housing as well as an automatic clot and tip loss detection. No filtration, centrifugation, or vacuum pumps are necessary, which minimizes the risk of cross-contamination. Up to 32 nucleic acid isolations (the eight-nozzle pipette head allows a variable number of samples from 1 to 32 per run) can be...

Genetic Testing And Counseling In Hereditary Breast And Ovarian Cancer Syndrome

Genetic testing for HBOC has become generally accepted as part of standard clinical practice and should be offered to any patient that has personal or family history features suggestive of HBOC (Table 3) and when genetic testing results could influence the medical management of that patient or the patient's family members. Clinical laboratories employ a variety of molecular techniques to detect germline mutations in BRCA1 and BRCA2 in a peripheral blood sample (Table 4). The sensitivity of...

Identification of E faecalis in GPCPCPositive Blood Culture Bottles

VRE have become a serious nosocomial pathogen because of the widespread use of vancomycin and require aggressive therapy with novel antibiotics, such as line-zolid and quinupristin dalfopristin. Resistance to vanco-mycin and also ampicillin among enterococci is primarily associated with Enterococcus faecium and a few other rare-occurring Enterococcus species, whereas E. faecalis, the most frequent species accounting for approximately two thirds of enterococcal isolates, is rarely resistant to...

Features Of Fraxa And Fraxe

Fmr1 Southern Blot

Clinical Phenotype, Genetics, and Biochemistry The fragile X syndrome affects males to a greater extent than females in males, learning and social deficits are moderate to severe, with social impairments usually preventing them from fathering offspring although sperm production is thought to be unaffected. In adult males, visible signs of the condition often include a large head, long face, large ears, and macroorchidism however, in children, the phenotype is likely to be restricted to...

Staphylococcal Enterotoxins

In addition to their nature as superantigens, SEs function as potent gastrointestinal toxins causing SFP, which has a major public health impact. 1,3-5 Superantigenicity and emesis activities of SEs have been shown to result from distinct regions of the toxin protein. SEs comprise a family of homologous but antigenically different exotox-ins, which are heat stable and resistant to inactivation by gastrointestinal proteases. SEs have also been implicated in several allergic and autoimmune...

Molecular Testing

With an increasing number of cases of IC but lack of a sensitive detection method, it has become essential to develop techniques that overcome traditional limitations. Molecular methods detecting nonculturable nonviable cells or circulating free fungal DNA have been developed, which may provide an alternative to culture-based techniques. Owing to these culture limitations, most diagnostic molecular mycology techniques have focused on detecting IC, with little work performed on detecting...

In Vivo Applications Liver Transduction

The liver is an attractive gene therapy target because the fenestrated endothelium permits exposure to intravenously delivered vector, hepatocytes are well suited for secretion of therapeutic proteins into the circulation for systemic delivery, and it is the affected organ in many genetic disorders. Helper-dependent adenoviral vectors are particularly attractive vectors for liver-directed gene therapy because of their ability to efficiency transduce hepatocytes following intravenous injection....

In Vitro Diagnostic Applications

The generic PNA-FISH assay procedure allows PNA-FISH to be applied for various blood pathogens without procedural changes, such that separate tests can be performed in parallel. Using the results from Gram staining, appropriate PNA-FISH tests can be selected to identify or rule out relevant pathogens (Fig. 2). Fig. 2 Application of PNA-FISH tests for direct identification of positive blood culture bottles. The result of the Gram stain provides a basis for the selection of appropriate PNA-FISH...

Molecular Basis And Implications For Genetic Counseling

Angelman syndrome is divided into five major types Type I. De novo interstitial deletions of region 15q11q13 are found in about 70 of all AS cases (Table 1). 7 Similar deletions have been reported in association with Prader-Willi syndrome (PWS), a disorder with different phenotype (see Prader-Willi syndrome). The deleted chromosomal area in AS is of maternal origin in contrast to PWS where the origin of the deletions is paternal. 8 These findings suggested the presence of imprinted genes in the...

Distance Dependence Of Fret

Fret Efficiency

Fluorescence resonance energy transfer efficiency is inversely proportional to the sixth power of the distance between a donor and acceptor, and therefore is extremely Fig. 1 A) General mechanisms of excited-state deactivation of a fluorophore. Up arrow represents transition from ground state (S0) to an Si excited state (thick line) or higher (thin lines) after photon absorption (wavy upward arrow). Down arrows represent relaxation, first from higher states down to Si (short arrow). Relaxation...

Aat Deficiency And Disease

Aat Deficiency

Homozygous Z individuals are predisposed to developing childhood cirrhosis 7 and pulmonary emphysema in early Fig. 1 Interaction of the protease trypsin with AAT. Trypsin docks on to the exposed RCL, cleaves the RCL, and the loop inserts into a sheet. The protease is then translocated to the opposite pole of the molecule and the active site of the protease is distorted. (See Ref. 1 .) Fig. 1 Interaction of the protease trypsin with AAT. Trypsin docks on to the exposed RCL, cleaves the RCL, and...

Combining Sample Preparation And Analysis In One Platform

The ideal handheld nucleic acid-based analysis device would incorporate both sample processing and real-time analysis and detection in one instrument. The technical challenges are formidable but some progress in fabricating such a device is underway. Nanosphere's proposed Verigene Mobile instrument (Fig. 4) promises to combine microfluidic purification of the sample and subsequent nucleic acid detection via hybridization with probe-bound nanoparticles, all in one handheld device. The Verigene...

Molecular Characterization

Methicillin resistance in S. aureus and other staphylococci is caused by the production of penicillin-binding protein 2a (PBP2a, also known as PBP2'), a novel 78-kilo Dalton penicillin-binding protein encoded by the mecA gene. 10 PBP2a, along with PBPs normally produced by S. aureus, are enzymes that catalyze peptidoglycan cross-linking reactions in the bacterial cell wall, resulting in a rigid structure that protects the bacterium against osmotic cell lysis and death. 10 However, PBP2a is...

The Amplicor HCV Monitor 20 and Cobas Amplicor HCV Monitor 20 Test Roche Diagnostic Systems

Based on reverse transcription polymerase chain reaction (RT-PCR), the Amplicor HCV Monitor test (Roche Diagnostic Systems) was developed. 5 Recently, an improved version 2.0 was introduced, which achieved an equivalent quantitation of each genotype over the quantitative range (5 x 102 to 5 x 105 copies of RNA mL). 6,7 HCV RNA is extracted from plasma by chaotropic salt and is then precipitated by isopropanol. Both RT and PCR of RNA are accomplished in one tube using the recombinant...

Nuclic Acids Conclution

Alagille syndrome was initially described as the association of five major features paucity of interlobular bile ducts, peripheral pulmonary artery stenosis, butterfly-like vertebral arch defect, posterior embryotoxon, and a peculiar facies. Because of the variable expressivity of the syndrome, individuals presenting with three of the five main features are considered to have AGS. There is a general agreement for considering that genetic testing is not necessary for the diagnosis of AGS which...

Biomarker Discovery Using Other Microarray Platforms

In addition to transcriptome expression microarrays, specific oligonucleotide microarrays have been applied to the study of DNA variation in clinical material. Multiple probes of short length that differ in sequence at a single base have been designed to identify simple polymorphisms and allelic variations in DNA. The primary applications of these types of microarrays have dealt with automated high-throughput identification of mutations in critical genes such as TP53, a valuable predictor for...

Retinitis Pigmentosa

Retinitis pigmentosa (RP) is an inherited disorder of the retina and is the sixth leading cause of blindness. Whereas current clinical strategies are primarily palliative in nature, research in animal models demonstrates that neurotrophic factors inhibit retinal degeneration caused by RP. Studies in the rd model of retinal degeneration demonstrated that CNTF gene transfer maintains retinal morphology, 17 and later studies in the rcdl dog model 18 using intravitreal implants of encapsulated...

Etiological Agent

M. leprae is a nonmotile, nonspore-forming, microaero-philic, acid-fast-staining bacterium that usually forms slightly curved or straight rods. M. leprae has never been grown on artificial media but can be maintained in axenic cultures in a metabolically active state for a few weeks. 5 As a result, propagation of M. leprae has been restricted to animal models including the armadillo, normal, and athymic rodents. 1 These systems have provided the basic resources for genetic, metabolic, and...

Well MADGE and 768Well MADGE

384-well microplates have become an established new standard in higher-throughput genomics research laboratories for clone operations (arrayed libraries, gridding, spotting, storage, etc.) and for PCR. The difficulties in thin-walled plastics manufactured for the latter have been solved. 384-well microplates have wells in a 16 x 24, 4.5-mm pitch array. A diagonal turn of this array would result in MADGE wells and tracks too narrow (< 1 mm) for manual access, but we have devised a 384-well...

Leprosy

Leprosy (Hansen's Disease) is a chronic infectious disease caused by infection with Mycobacterium leprae affecting the skin, mucous membranes, and peripheral nerves. 1 The predilection of M. leprae for peripheral nerves can result in nerve damage leading to sensory and motor paralysis which in turn can cause deformities of the hands and feet and blindness. It is estimated that 2-3 million patients suffer from irreversible nerve damage as a long-term consequence of M. leprae infection and that...

Clinical Features Of

Although hamartomas typically occur in several organ systems in TSC, the vast majority display limited growth potential and do not require intervention. A small fraction display persistent growth, necessitating surgical control. However, progression to malignancy is very rare in TSC and has been seen only in TSC renal hamartomas, termed angiomyolipoma AML , at a frequency of about 2 of all TSC patients. 1'2 Another remarkable feature of TSC hamartomas is that they first appear at different ages...

Macromolecular Composition

Chlamydiae have a bilayered cell membrane similar to other Gram-negative bacteria. The cell membrane contains species-specific antigens such as the major outer membrane protein MOMP , as well as common antigens such as lipopolysaccharide LPS . 4 Major outer membrane protein is the most prominent membrane protein making up about 60 of the surface proteins. Variable domains of this protein allow the division of C. trachomatis but not C. pneumoniae, into different serovars. In the genome of C....

The Importance Of Determining Pon1 Status

In recent years, the importance of determining an individuals' PON1 status has been repeatedly highlight-ed. 7,9-13 The term PON1 status includes both the PON1192 genotype as well as PON1 activity. The concept was prompted by examination of a number of epidemi-ological studies, which examined only the PON1192 and PON155 genotypes, without considering the large Fig. 1 The PON1 gene is located on human chromosome 7, near the genes encoding PON2 and PON3. The expanded PON1 gene diagram shown...

Genetic Variation In Echinococcus

E. granulosus comprises a number of intraspecific variants or strains that exhibit considerable variation at the genetic level. 2-4 Conversely, there is very limited genetic variation within E. multilocularis 2,3 although recent microsatellite analysis has shown such markers can be used to examine E. multilocularis population structure.1-5-1 There are no available data to indicate that either Echinococcus vogeli or Echinococcus oligarthrus, the other recognized Echinococcus species, is...

Minor Groove Binder Probes

A recent improvement on classical TaqMan probes is the development of minor groove binders MGB chemistry.1-12-1 Modification of an oligonucleotide with an MGB such as dihydroclyclopyrroloindole tripeptide DPI3 results in a substantial increase in the interaction of the oligonucleotide with a complementary DNA strand. The MGB effectively acts as a clamp that secures the base-pairing interaction between the oligonucleotide and the target DNA sequence Fig. 2 . The MGB interacts with the minor...

Qbl

In the absence of any ''gold standard'' method for genetic testing, reference materials must be certified by a consensus approach. The range of approaches used for each RM will be determined by the nature of the genetic change contained in the RM. For example, large triplet repeat expansions fragile X syndrome, myotonic dystrophy are not amenable to standard polymerase chain reaction PCR amplification and must be analyzed by Southern blotting or by a modified PCR method, whereas single-base...

Threat Agent Detection Impetus For Handheld Nucleic Acid Analyzer Development

Food Bacteria Analyzer

Successful performance of PCR obviously depends on the ability of the thermal cycling platform to maintain accurate gradations of temperature in the manifold or block containing the reaction tubes. The heating and cooling apparatus necessary to provide these temperature changes places constraints on the size and weight of the thermal cycler. ''First-generation'' thermal cyclers, such as the Perkin Elmer 480 model instrument, while reasonably light in weight and small in footprint, were not...

Mechanisms Of Drug Resistance In Giardia

Many effective drugs are available for treatment, as shown in Table 1. Albendazole has been reported to be as efficacious as metronidazole. Chromosome mapping of a gene expressed in drug-resistant lines revealed that chromosomes could rearrange and that segments could be lost. Further mapping studies indicated that the minor chromosomes observed earlier were partial duplications of major chromosomes with loss of substantial subtelomeric regions from different chromosomal termini. The extensive...

Pathophysiology

Mutations in the ABCC6 gene have recently been found to underlie PXE in nearly all affected individuals.1-2-4,7-9-1 ABCC6 is located on chromosome 16p13.1, and its 31 exons are dispersed over 73 kb of genomic sequence. 2 Its translated region spans 4.5 kb and encodes multidrug resistance-associated protein 6, MRP6, 10,11 an ATP-dependent efflux pump that is expressed at the basolateral membranes of hepatocytes and the proximal tubules in the kidneys. 12 The protein is composed of three...

Laboratory Methods Protein And Dna Analysis

The initial step in investigation of a suspected hemoglo-binopathy is to obtain a complete blood count CBC . Inspection of the blood smear red cell morphology is particularly useful in detecting an unstable hemoglobin, SCD, or thalassemia. A reticulocyte count is indicated whenever there is hemolysis, which may occur with unstable hemoglobins or SCD. Proteomic diagnosis using electrophoretic separations is the foundation for analysis of hemoglobin variants. Presumptive diagnosis of an abnormal...

Snp Typing Using The Lamp Method

To detect a single nucleotide difference by LAMP-based SNP typing, both FIP and BIP were designed to contain SNP nucleotides on the target sequence at each 5' end. Figure 3A shows the basic principles of the LAMP cycling reaction with the WT primer set, using WT DNA Fig. 3A, upper and MUT DNA Fig. 3A, lower as templates. When LAMP reaction using the WT primer set is carried out with WT DNA as the template, a dumbbelllike structure is generated with both ends being overlapped by self-annealing...

Histotoxic Infections Disease Summary

C. perfringens causes three histotoxic infections simple wound infections, anaerobic cellulitis, and clostridial myonecrosis or gas gangrene. The most serious of these diseases, gas gangrene, is an aggressive invasive infection that advances rapidly despite antibiotic therapy. 16 Most gas gangrene cases result from major traumatic injuries that allow for the introduction of exogenous or endogenous C. perfringens responsible for 80 of gas gangrene cases into an ischemic environment.1-16-1 Gas...

Tct Ggg Tag Cca Ttt Atg Gcg Aac Cag

50 nL reaction 0.5 mM dNTPs, 1.0 mM MgCl2, 1.5 U Taq polymerase 35 cycles 94 C 30 sec, 62 C 1 min, 72 C 2 min 1 cycle 72 C 5 min blotting alkali blotting to a nylon filter antidigoxigenin-alkaline phosphatase labeling 100 nL reaction 0.2 mM dNTPs, 1.5 mM MgCl2, 2.5 U Taq polymerase 1 cycle 94 C 3 min, 59 C 1 min, 72 C 1.5 min 40 cycles 94 C 45 sec, 59 C 1 min, 72 C 1.5 min restriction fragment length polymorphism RFLP as instructed by manufacturer 5'-AGC CTT TCC TTC TGG GTA GCC ATT fluorescein...

Genetic Counseling Dm1

Genetic counseling of an affected proband or an asymptomatic mutation carrier aims to clarify their genetic status and relies on the family history and genetic testing. In case of an affected proband it is essential to investigate the parents, sibs, and offsprings of the proband. Offsprings of a DM1 patient carry a 50 chance of inheriting the mutant allele. The chance of a female DM1 patient of having an affected child increases with the severity of the maternal phenotype. A mother who has had...

Conventional Cytogenetics In Detecting Recurring Chromosomal Abnormalities In Hematopoietic Disorders

Conventional cytogenetic analysis using G-banding is a powerful technique that enables one to gain a complete picture of the human genome at a glance Fig. 2 . Bone marrow is the tissue of choice for conventional cytoge-netic studies of acquired chromosomal abnormalities in most hematological conditions. Nevertheless, a stimulated culture of peripheral blood is sometimes performed besides an unstimulated culture of the bone marrow to ascertain whether an observed chromosomal abnormality, when...

Quantitative Nasba And Tma Applications

Quantitative nucleic acid amplification tests are gradually introduced into the laboratory. These assays are used for determination of the viral load of patients infected with blood-borne viruses such as human immunodeficiency virus type 1 HIV-1 and hepatitis C virus HCV . HIV-1 RNA Using the NucliSens HIV-1 QT bio-Merieux , 13'14 between 25 and gt 5 x 106 copies mL of HIV-1 RNA can be detected with a 95 detection rate of 176 copies mL, by using 1 mL of EDTA, citrate, or heparin plasma as a...

Human Platelet Antigens Nomenclature

Historically, multiple names existed for the human platelet antigens. In 1990, the Platelet Serology Working Party of the International Society of Blood Transfusion ISBT and the International Committee for Standardization in Haematology ICSH suggested a numerical terminology which has been widely accepted. 1 The term HPA was introduced to indicate human platelet antigen. By convention, ''system'' is assigned to an HPA where both SNP and alloantibodies have been identified. The different...

Problems Associated With Telomere Length Measurement

The most authoritative recent review on telomere biology and papers describing the key discoveries mentioned above as well as methodological advances are listed in the reference list. 1-6 The classical method for telomere length measurement is based on Southern blot analysis. In a typical protocol, DNA is extracted from a cell sample and the resulting DNA mix is exposed to frequently cutting restriction enzymes, which will produce a series of DNA fragments, and those fragments containing...

Hiv Viral Load Assays

There are four commercially available HIV RNA viral load assays in common use Nucleic acid sequence-based amplification NASBA , branched chain DNA amplification bDNA , reverse transcription PCR RT-PCR , and the ligase chain reaction LCx . The NASBA assay Organon Technica utilizes the Boom method for the extraction of total RNA from a plasma sample and this method produces sufficient high-quality RNA that can be used for other investigations such as HIV genotyping. The major difficulty with...

Ns4

Gen. region genomic region of the HCV used for genotyping Routine lab suitable for routine diagnostic laboratory settings 5'NC 5' noncoding region DM direct method based on molecular typing 5'UTR 5' untranslated region E1 envelope 1 IM indirect method NS4 nonstructural 4 region. OpenGene DNA sequencing system Bayer that is combined with the automated Long-Read Tower for the separation of the sequenced fragments. Data are acquired with the GeneLibrarian module of the GeneObjects Bayer software....

Bioassays For Diphtheria Toxin

Bioassays are based on the ability of diphtheria toxin to cause death, dermonecrosis, inhibition of protein synthesis, or other toxic effects in highly susceptible animals such as rabbits or guinea pigs or in cultured cells derived from them. The molecular basis for the toxicity of diphtheria toxin has been well studied reviewed in Ref. 10 . Diphtheria toxin is secreted by C. diphtheriae as a single mature polypeptide of 28,350 Da, containing 535 amino acid residues. Proteolytic nicking of...

Epidemiology And Typing

Although the origin of a particular Campylobacter infection is rarely traced, transmission probably occurs via fecal contamination. Other sources of Campylobacter infection include unpasteurized milk, water, and pet contact. The infective dose is low, being about 800 cells ingested. Campylobacter species represent a taxonomically heterogeneous group and many typing methods have been used to study the epidemiology of Campylobacter infections. These include biotyping, serotyping, phage typing,...

Sn38g

Fig. 3 The metabolic pathway of UGT1A1 action. View this art in color at www.dekker.com. most important inactivation pathway of CPT-11. This step is catalyzed by UGT1A1, an enzyme that is also responsible for bilirubin conjugation. The formation of glucuronide is the limiting step for renal clearance, which provides the solubility in water. Therefore, decreased UGT1A1 might not only cause hyperbilirubinaemia unconjugated bilirubin , but also the accumulation of SN-38 and the toxic side effects...

COBAS Ampli Prep

The COBAS AmpliPrep robotic workstation Roche Diagnostics, Mannheim, Germany is a fully automated system which isolates DNA and RNA targets. It is based on silico-coated glass particles which bind the extracted nucleic acids. Internal controls allow target recovery monitoring. Up to 72 samples three racks of 24 specimens each can be loaded on the system simultaneously. Reagents are delivered in sealed, bar-coded, ready-to-use cassettes. The pipetting integrity check ensures the accurate...

D13s797 I

Annotation created toy DNannotator 99 25974_143 99-25965_399 99-16 047_115 99-16105_152 G3 6 exon4 99 25966_241 99-25973.317 99-25989.393 G30 exonl 99-24553_410 99-5919_215 99-16 052_214 99-16 032.292 99-15375.165 03 0 X0n6 G301exon7 99-15880.162 072 exoni G30 exon5I 0721exona G72_ isol Iexoni G72 exon3 G72_iso1 exon2 99 15 038_IIS 8-155.258 G aiexon4 I 072_isol xon3 I 99-1587 99-5897_143 8-130_143 G72 exon5I C72_isoi e on4 G7 exone G72_isol xonS I G301exon3 I G301exon2 99-24644_194 cnromosome...

Immunoassays For Diphtheria Toxin

Immunoassays are based on the ability of specific polyclonal or monoclonal antitoxic antibodies to bind diphtheria toxin. Typically, immunoassays do not distinguish between biologically active forms of diphtheria toxin and biologically inactive forms that retain full or partial antigenicity such as diphtheria toxoid or partially denatured diphtheria toxin . Immunoassays provide inexpensive and fairly rapid substitutes for bioassays in determining the toxigenicity of clinical isolates of C....

Genotypic Tests For Diphtheria Toxin

A genotypic test is designed to detect the nucleotide sequence for a particular gene. Unlike an immunoassay for a protein, a genotypic test does not require that the gene product be produced. Therefore a genotypic test for tox is one step more remote from a bioassay for diphtheria toxin than an immunoassay. Because many tests for specific DNA sequences have high sensitivity, it is possible to develop tests for tox that will have few false-negative results. However, the converse is not true,...

Peculiarities Of Iso 151892003

ISO 151189 2003 recognizes the major particularities of medical laboratories in comparison to other chemical test laboratories. In contrast to calibration and testing laboratories, the methods applied in laboratory medicine are a compromise between available amount of sample material, turnaround time, test feasibility, and economical reality. Table 2 summarizes the principal differences regarding methods, sample size, validation of results, time span between sampling and the availability of a...

Molecular Diagnosis Of Alphathalassemia

The presence of alpha-thalassemia, suspected on the basis of hematological and or clinical findings i.e., micro-cytosis with normal HbA2 and F and normal serum iron status in carriers microcytic and hypocromic hemolytic anemia with RBC inclusion bodies and a fast-moving band HbH at the hemoglobin electrophoresis presence of Hb Bart's in the newborn , should be confirmed, if requested, by globin gene synthesis or even better by globin gene DNA analysis. The exact definition of the genotype with...

Biochemical and Molecular Evidence for the Pathogenicity of A1555G

Because aminoglycosides bind the small rRNA and exert their effect by inhibiting or inducing errors in protein synthesis, it is not surprising that mutations in the corresponding 12S rRNA in humans are responsible for AID. 1 Aminoglycosides bind at, or near, two regions of the Escherichia coli small rRNA and these regions, brought together in the secondary and tertiary structures, surround the decoding site of the ribosome Fig. 1A . The A1555G mutation introduces a new base pair at a region of...