Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genetic analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources
PubMed2004

Microbiological and genetic analysis of probiotic products licensed for medicinal purposes.

BACKGROUND: The purpose of our study was to investigate both qualitatively and quantitatively the microbial content of probiotic products licensed for medicinal purposes. MATERIAL/METHODS: Microbiological analysis was performed on five different brands of probiotic products that claimed to contain lactobacilli and/or bifidobacteria. The species were determined based on phenotypic characters, using API 50CH, API 20A, and API rapid ID 32A kits. Bacterial strains belonging to the Bifidobacterium genus were further identified using genotypic methods (amplification of specific DNA fragments by PCR and analysis of their nucleotide sequences). The products were also analyzed for pathogenic bacteria. The number of microorganisms contained in four of the products was determined using the plate-count method and the most-probable-number method. The actual and claimed content of probiotic products was analyzed statistically. RESULTS: Microbiological and genetic analysis showed that, in terms of quality, only three of the five products contained the bacterial strains claimed on the label. None of the tested products contained pathogens. Quantitative analysis demonstrated that 57 of 64 samples (89% [95% CI: 81-97]) contained bacterial counts at the cell densities (doses) claimed on the label. CONCLUSIONS: Our study demonstrates unsatisfactory qualitative microbiological specification in the tested products. However, there was good quantitative agreement with the labeling. Our findings indicate that regulations governing the labeling of probiotic products are urgently required.

Bacterial Typing Techniques↗
PubMed1995

Molecular and genetic analysis of the toxic effect of RAP1 overexpression in yeast.

Rap1p is a context-dependent regulatory protein in yeast that functions as a transcriptional activator of many essential genes, including those encoding ribosomal proteins and glycolytic enzymes. Rap1p also participates in transcriptional silencing at HM mating-type loci and telomeres. Overexpression of RAP1 strongly inhibits cell growth, perhaps by interfering with essential transcriptional activation functions within the cell. Here we report a molecular and genetic analysis of the toxic effect of RAP1 overexpression. We show that toxicity does not require the previously defined Rap1p activation and silencing domains, but instead is dependent upon the DNA-binding domain and an adjacent region of unknown function. Point mutations were identified in the DNA-binding domain that relieve the toxic effect of overexpression. Two of these mutations can complement a RAP1 deletion yet cause growth defects and altered DNA-binding properties in vitro. However, a small deletion of the adjacent (downstream) region that abolishes overexpression toxicity has, by itself, no apparent effect on growth or DNA binding. SKO1/ACR1, which encodes a CREB-like repressor protein in yeast, was isolated as a high copy suppressor of the toxicity caused by RAP1 overexpression. Models related to the regulation of Rap1p activity are discussed.

Alleles↗
PubMed1989

Genetic analysis of immortalizing functions of Epstein-Barr virus in human B lymphocytes.

Epstein-Barr virus (EBV), a herpes virus, infects human B lymphocytes in vitro and efficiently immortalizes them. About 10 of the approximately 100 genes of EBV are expressed in recently immortalized B cells and although there is circumstantial evidence that at least three of these may contribute to the process of immortalization, there is no direct evidence that any particular gene is required. We have developed a genetic analysis of EBV that uses a transformation-defective strain of the virus as a helper virus in conjunction with DNA that contains all of the viral cis-acting elements required for replication, cleavage and packaging during the lytic phase of the viral life cycle. This DNA can include viral genes required for immortalization that complement the transformation-defective virus strain. The DNA can be amplified and packaged by the products of the helper virus and the packaged DNA is infectious. We have analysed two viral genes expressed in immortalized cells and find that the gene encoding EBV nuclear antigen-2 is required for immortalization, whereas the gene for the EBV nuclear antigen leader protein is not.

Antigens, Viral↗
PubMed2004

[Genetic analysis of X-chromosome neurodegenerative mutants of Drosophila melanogaster induced by ethyl methansulfonate and nitrosoethylurea].

In a series of Drosophila mutants with changes in the brain structure, some characters (reduced life span, behavioral changes, and neuronal loss in various brain regions) resemble symptoms observed in human patients with neurodegenerative diseases. In addition, similar specific phenotypes shared by different species suggest that common mechanisms underlie degeneration of their nerve cell. This study reports the results of a genetic analysis of new X-chromosome mutants with neurodegenerative changes in brain structure, which were induced by chemical mutagenesis. According to complementation test, all mutants were divided into three complementation groups, in which the life span and dynamics of neurodegenerative changes were studied. The life span of Drosophila melanogaster flies was found to depend on the state of their nervous system.

Animals↗
PubMed1992

Genetic analysis of ras homologs in yeasts.

Ras proteins with extensive structural homology to mammalian p21ras have been studied in the two yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. Comparative analysis of these two yeasts has revealed significant differences in the biochemical and physiological functions that are controlled by this subgroup of eukaryotic GTP-binding regulatory proteins. Despite such divergence of cellular functions, proteins and mechanisms involved in the regulation and modification of Ras proteins are highly conserved in yeasts and other eukaryotes. Genetic analysis of the function of yeast proteins that regulate or modify Ras proteins has provided important information about Ras proteins in general.

Adenylyl Cyclases↗
PubMed2003

Pseudomigraine with lymphocytic pleocytosis: a calcium channelopathy? Clinical description of 10 cases and genetic analysis of the familial hemiplegic migraine gene CACNA1A.

OBJECTIVE: To report the clinical findings of 10 patients diagnosed with pseudomigraine with lymphocytic pleocytosis and the results of mutational analysis of the CACNA1A gene in 8 of these patients. BACKGROUND: Pseudomigraine with lymphocytic pleocytosis, also referred to as headache with neurologic deficits and cerebrospinal fluid lymphocytosis (HaNDL), is characterized by episodic transient neurologic dysfunction associated with moderate to severe headache and cerebrospinal fluid lymphocytic pleocytosis. Episodes are recurrent and the condition is self-limiting. The etiology of this sporadic condition remains unknown, but the episodic nature and its ability to be triggered by angiography is somewhat reminiscent of the phenotypic features of familial hemiplegic migraine, a condition caused by mutations in the CACNA1A gene. DESIGN/METHODS: Utilizing retrospective chart review, we describe the clinical features of pseudomigraine with lymphocytic pleocytosis in 10 patients. Whole blood was taken from 8 patients (2 were lost to follow-up) and used for DNA testing. The CACNA1A gene was screened for mutations using heteroduplex analysis and direct DNA sequencing. RESULTS: Clinical features of pseudomigraine with lymphocytic pleocytosis included transient episodes of weakness, sensory and visual symptoms, aphasia, and confusion lasting minutes up to 4 hours. Sensory symptoms, typically affecting the face and arm, were the most common presentation. Localization of symptoms did not conform to vascular territories. Headache was typically throbbing and most often bilateral. Genetic analysis did not identify any mutations in the CACNA1A gene. CONCLUSIONS: Similarities between familial hemiplegic migraine and pseudomigraine with lymphocytic pleocytosis include recurrent headache with reversible neurologic deficit, cerebrospinal fluid lymphocytic pleocytosis, and triggers such as angiography. Even so, heteroduplex analysis and DNA sequencing failed to identify any sporadic mutations or shared polymorphisms in the exons or the intron/exon boundaries of the CACNA1A gene. These results do not support a role of the CACNA1A gene in the etiology of pseudomigraine with lymphocytic pleocytosis.

Adult↗
PubMed2004

Genetic analysis of RNA-mediated transcriptional gene silencing.

The 'nuclear side' of RNA interference (RNAi) is increasingly recognized as an integral part of RNA-mediated gene silencing networks. Current data are consistent with the idea that epigenetic changes, such as DNA (cytosine-5) methylation and histone modifications, can be targeted to identical DNA sequences by short RNAs derived via Dicer cleavage of double-stranded RNA (dsRNA). To determine the relationships among RNA signals, DNA methylation and chromatin structure, we are carrying out a genetic analysis of RNA-mediated transcriptional gene silencing (TGS) in Arabidopsis. Results obtained so far indicate that in response to RNA signals, different site-specific DNA methyltransferases (DMTases) cooperate with each other and eventually with histone-modifying enzymes to establish and maintain a transcriptionally inactive state at a homologous target promoter. Processing of dsRNA in Arabidopsis occurs in the nucleus and in the cytoplasm, where distinct Dicer-like (DCL) activities are thought to generate functionally distinct classes of short RNAs. RNA silencing pathways thus operate throughout the cell to defend against invasive nucleic acids and to regulate genome structure and function.

Animals↗
PubMed2001

Genetic analysis of Brugada syndrome in Israel: two novel mutations and possible genetic heterogeneity.

Idiopathic ventricular fibrillation in patients with an electrocardiogram (ECG) pattern of right bundle branch block and ST-segment elevation in leads V1 to V3 (now frequently called Brugada syndrome) is associated with a high incidence of syncopal episodes or sudden death. The disease is inherited as an autosomal dominant trait. Mutations in SCN5A, a cardiac sodium channel gene, have been recently associated with Brugada syndrome. We have analyzed 7 patients from Israel affected with Brugada syndrome. The families of these patients are characterized by a small number of symptomatic members. Sequencing analysis of SCN5A revealed two novel mutations, G35S and R104Q, in two Brugada patients, and a possible R34C polymorphism in two unrelated controls. No mutations were detected in 5 other patients, suggesting genetic heterogeneity. Low penetrance is probably the cause for the small number of symptomatic members in the two families positive for the SCN5A mutations.

Adult↗
PubMed2003

Time-course genetic analysis of albuminuria in Dahl salt-sensitive rats on low-salt diet.

The Dahl salt-sensitive hypertensive (S) rat develops albuminuria early in life even on a low-salt diet. In contrast, the spontaneously hypertensive rat (SHR) is highly resistant to developing albuminuria despite elevated BP. An F(1) hybrid of S and SHR showed a low urinary albumin excretion (UAE) and low urinary protein excretion (UPE) similar to SHR, i.e., SHR was dominant. A genetic analysis was carried out on a large population (n = 276) obtained by backcrossing F(1) rats to the recessive S strain; the population was fed a low-salt diet. Genome scans done at 8, 12, and 16 wk of age yielded ten quantitative trait loci (QTL) for UAE and/or UPE with variable time-course patterns on nine rat chromosomes (RNO), i.e., RNO1, RNO2, RNO6, RNO8, RNO9, RNO10, RNO11, RNO13, and RNO19. There were two UPE QTL on RNO6. At most of the UAE and/or UPE QTL, the S allele was associated with increased excretion, except for one of the QTL on RNO6 and the QTL on RNO11, where the S allele caused decreased excretion. Only the UAE and UPE QTL on RNO10 co-localized with a BP QTL. The S allele on RNO10 caused higher BP and higher UAE. Two additional BP QTL were detected on RNO1 and RNO6. Most of the UAE and UPE QTL co-localized with QTL for kidney lesions characteristic of S rats. Multiple interactions were observed for UAE, many of which involved RNO2. In summary, UAE is highly polygenic and the majority of the QTL altering UAE do not co-localize with QTL for BP as evaluated by tail-cuff measurements of BP.

Albuminuria↗
PubMed2005

Genetic analysis of biosurfactant production in Ustilago maydis.

The dimorphic basidiomycete Ustilago maydis produces large amounts of surface-active compounds under conditions of nitrogen starvation. These biosurfactants consist of derivatives of two classes of amphipathic glycolipids. Ustilagic acids are cellobiose lipids in which the disaccharide is O-glycosidically linked to 15,16-dihydroxyhexadecanoic acid. Ustilipids are mannosylerythritol lipids derived from acylated beta-d-mannopyranosyl-d-erythritol. Whereas the chemical structure of these biosurfactants has been determined, the genetic basis for their biosynthesis and regulation is largely unknown. Here we report the first identification of two genes, emt1 and cyp1, that are essential for the production of fungal extracellular glycolipids. emt1 is required for mannosylerythritol lipid production and codes for a protein with similarity to prokaryotic glycosyltransferases involved in the biosynthesis of macrolide antibiotics. We suggest that Emt1 catalyzes the synthesis of mannosyl-d-erythritol by transfer of GDP-mannose. Deletion of the gene cyp1 resulted in complete loss of ustilagic acid production. Cyp1 encodes a cytochrome P450 monooxygenase which is highly related to a family of plant fatty acid hydroxylases. Therefore we assume that Cyp1 is directly involved in the biosynthesis of the unusual 15,16-dihydroxyhexadecanoic acid. We could show that mannosylerythritol lipid production is responsible for hemolytic activity on blood agar, whereas ustilagic acid secretion is required for long-range pheromone recognition. The mutants described here allow for the first time a genetic analysis of glycolipid production in fungi.

Amino Acid Sequence↗
PubMed2001

HOW GIBBERELLIN REGULATES PLANT GROWTH AND DEVELOPMENT: A Molecular Genetic Analysis of Gibberellin Signaling.

Gibberellins are hormones that control growth and a wide variety of other plant developmental processes. In recent years, significant progress has been made on the biochemistry of gibberellin biosynthesis and on the mechanisms by which gibberellin levels are regulated in plants. There have also been major advances in the understanding of gibberellin signaling, with several key genes being cloned. This review discusses our current understanding of gibberellin signaling, as seen from the perspective of molecular genetic analysis, and relates these observations to previous biochemical studies. In particular, we highlight an important conclusion of recent years: that GAI/RGA and orthologs play major roles in gibberellin signaling in diverse plant species, and that gibberellin probably stimulates growth by derepression of GAI/RGA.

Journal Article↗
PubMedDate not supplied

Genetic analysis of Leishmania mexicana infection in mice: single gene (Scl-2) controlled predisposition to cutaneous lesion development.

Subcutaneous inoculation of Leishmania mexicana amastigotes into the shaven rumps of DBA/2 mice results in a unique 'no lesion growth' phenotype not observed in other mouse strains. Statistical analysis (Kolmogorov-Smirnov and log likelihood tests) of lesion diameters in F1, F2 and backcross progeny from (C57BL/6 x DBA/2) matings indicate that segregation between lesion growth and no lesion growth phenotypes comes under single gene control. The gene has been designated Scl-2 for susceptibility to cutaneous leishmaniasis locus 2. Preliminary mapping studies using 12 of the 26 BXD recombinant inbred mouse strains suggest a location for Scl-2 near Xmmv-8 on a region of mouse chromosome 4 showing homology with human 9p. The identification and mapping of this murine resistance gene could provide an important tool for genetic analysis of susceptibility and resistance to cutaneous leishmaniasis in man.

Animals↗
PubMed2005

The importance of non-invasive genetic analysis in the initial diagnostics of Alport syndrome in young patients.

Alport syndrome is an important hereditary disorder characterized by nephritis and sometimes accompanied by impairment or loss of vision and hearing. The most common form of Alport syndrome is an X-linked dominant trait that has been associated with the gene COL4A5, one of the six types of IV collagen genes. More than 300 different mutations have been identified in the COL4A5 gene, and appear randomly along the whole gene. Three novel mutations, G198E, G3189D and G669R, were found in 5 young patients from 3 different Slovenian families. On the basis of the results of our study and the existing national register of Alport syndrome patients, we demonstrated that non-invasive methods, such as the genetic analysis of collagen genes, particularly in the case of young patients with undefined clinical features, may be of great importance and could diminish the need for invasive skin and renal biopsy. Our study showed the importance of molecular genetic data for the purpose of providing quick and precise diagnoses for affected family members and their offspring, particularly small children.

Age Factors↗
PubMed2005

Genetic analysis of the kinome and phosphatome in cancer.

Protein phosphorylation is a well-characterized biochemical process for reversible regulation of protein activity. Protein kinases and protein phosphatases are the key complementary players in this process, and through their coordinated activity cell homeostasis is tightly controlled. If these enzymes display aberrant activity, cells may undergo unrestrained growth, thus giving rise to complex diseases such as cancer. The technological platform gathered during the Human Genome Project recently allowed the systematic identification of the genetic alterations present in the kinase (the kinome) and the phosphatase (the phosphatome) gene families. These studies suggest that most if not all human tumors carry genetic alterations in at least one phosphatase or kinase gene. Here we integrate the biochemical knowledge on the properties of these molecules with the information collected through their systematic genetic analysis in cancer. We also analyze why the molecular profiling of the kinome and phosphatome in individual cancers is revolutionizing basic and clinical oncology.

DNA Mutational Analysis↗
PubMed1996

Ovarian small cell carcinoma with K-ras mutation: a case report with genetic analysis.

A rare case of ovarian small cell carcinoma is reported. Laboratory examination of a 46-year-old woman with a lower abdominal tumor showed marked hypercalcemia. Her condition deteriorated progressively, and she died one month after admission. A right ovarian tumor, 8 cm in diameter, metastases to multiple organs, and intraperitoneal bleeding were confirmed by autopsy. Microscopically, the small tumor cell had rounded nuclei with small distinct nucleoli and a scanty cytoplasm. Small cell carcinoma was diagnosed from these histological features and the clinical course associated with hypercalcemia. Immunohistochemical studies showed positive staining of neuron specific enolase (NSE) and keratin. Genetic analysis using DNA extracted from paraffin sections of metastatic lesions revealed mutation of K-ras codon 12. Loss of heterozygosity of the p53 and adenomatous polyposis coli (APC) genes was not informative. Previous reports have shown that ras gene mutations occur in 30% of epithelial ovarian tumors and significantly more frequently in mucinous than in other types of ovarian tumors. These results suggest that small cell carcinoma is of epithelial origin and may have a genetic alteration similar to that of mucinous tumors.

Base Sequence↗
PubMed1987

Genetic analysis of a transposon carrying toluene degrading genes on a TOL plasmid pWW0.

Toluene degrading (xyl) genes on a Pseudomonas TOL plasmid pWW0 are located within a 39-kb DNA portion. The 56-kb region including these xyl genes and its 17-kb derivative with a deletion of the internal 39-kb portion transposed to various sites on target replicons such as pACYC184 and R388 in Escherichia coli recA strains. Thus the 56- and 17-kb regions were designated Tn4651 and Tn4652, respectively. Genetic analysis of Tn4652 demonstrated that its transposition occurs by a two-step process, namely, cointegrate formation and its subsequent resolution. The presence in cis of DNA sequences of no more than 150 bp at both ends of Tn4652 was prerequisite for cointegrate formation, and this step was mediated by a trans-acting factor, transposase, which was encoded in a 3.0-kb segment at one end of the transposon. Cointegrate resolution took place site-specifically within a 200-bp fragment, which was situated 10 kb away from the transposase gene. Based on the stability of cointegrates formed by various mini-Tn4652 derivatives, it was shown that the cointegrate resolution requires two trans-acting factors encoded within 1.0- and 1.2-kb fragments that encompass the recombination site involved in the resolution.

Chromosome Deletion↗
PubMed2005

Genetic analysis of feline caliciviruses associated with a hemorrhagic-like disease.

Feline calicivirus (FCV) is 1 of the most common causes of upper respiratory tract disease in cats. Other disease syndromes associated with FCV infection have been reported. Recently, calicivirus infection associated with a hemorrhagic-like disease leading to significant mortality in cats has been reported. The clinical signs are similar to those observed with the calicivirus of rabbit hemorrhagic disease. This study characterized 2 FCV isolates associated with hemorrhagic-like disease. Nucleotide sequencing of the complete genome has been done for these 2 isolates as well as for 4 additional isolates representing other disease syndromes. Previously reported sequence data for the entire genome of classical FCV (6 isolates) and a portion of the capsid gene for hemorrhagic-like FCV (3 isolates), isolated in different regions of United States were used in the genetic analysis. Sequence data were used to determine relationships among the isolates and any correlation with phenotype. Nucleotide sequence comparisons of the entire genome and individual open reading frames revealed high homology among all isolates. Data suggest that the virulence may have genetic determinants on the basis of phylogenetic clustering of the isolates associated with hemorrhagic-like disease.

Amino Acid Sequence↗
PubMed1999

Applications of constant denaturant capillary electrophoresis/high-fidelity polymerase chain reaction to human genetic analysis.

Constant denaturant capillary electrophoresis (CDCE) permits high-resolution separation of single-base variations occurring in an approximately 100 bp isomelting DNA sequence based on their differential melting temperatures. By coupling CDCE for highly efficient enrichment of mutants with high-fidelity polymerase chain reaction (hifi PCR), we have developed an analytical approach to detecting point mutations at frequencies equal to or greater than 10(-6) in human genomic DNA. In this article, we present several applications of this approach in human genetic studies. We have measured the point mutational spectra of a 100 bp mitochondrial DNA sequence in human tissues and cultured cells. The observations have led to the conclusion that the primary causes of mutation in human mitochondrial DNA are spontaneous in origin. In the course of studying the mitochondrial somatic mutations, we have also identified several nuclear pseudogenes homologous to the analyzed mitochondrial DNA fragment. Recently, through developments of the means to isolate the desired target sequences from bulk genomic DNA and to increase the loading capacity of CDCE, we have extended the CDCE/hifi PCR approach to study a chemically induced mutational spectrum in a single-copy nuclear sequence. Future applications of the CDCE/hifi PCR approach to human genetic analysis include studies of somatic mitochondrial mutations with respect to aging, measurement of mutational spectra of nuclear genes in healthy human tissues and population screening for disease-associated single nucleotide polymorphisms (SNPs) in large pooled samples.

Base Sequence↗