Biomedical subjects

A Friedmann

Publications and source records attributed to A Friedmann.

At least 19 recordsLinked to original sources

PubMed2002

A PCR-based method for the detection of Streptococcus agalactiae in milk.

Bovine mastitis caused by Streptococcus agalactiae is mainly subclinical and therefore can be diagnosed only in the laboratory. We developed a polymerase chain reaction (PCR)-based method for specific and sensitive detection of S. agalactiae in raw milk. The specificity of the PCR reaction is based on unique S. agalactiae DNA sequences within the 16S subunit of the rRNA genes. Two pairs of sequences were used as positive controls; general streptococci primers, which anneal to conserved areas within the 16S rRNA subunit gene, and primers, which anneal to sequences within bovine mitochondrial DNA. The method of detection includes selective enrichment of S. agalactiae in the milk sample, followed by DNA extraction using a rapid and simple procedure developed for this purpose, and specific PCR reaction with appropriate controls. The method enables the detection of one bacterium in 1 ml of raw milk. The method developed can be easily incorporated as part of routine screening of bulk milk collection tanks for early detection of infected cows in a herd.

Animals↗

PubMed2001

The UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase gene is mutated in recessive hereditary inclusion body myopathy.

Hereditary inclusion body myopathy (HIBM; OMIM 600737) is a unique group of neuromuscular disorders characterized by adult onset, slowly progressive distal and proximal weakness and a typical muscle pathology including rimmed vacuoles and filamentous inclusions. The autosomal recessive form described in Jews of Persian descent is the HIBM prototype. This myopathy affects mainly leg muscles, but with an unusual distribution that spares the quadriceps. This particular pattern of weakness distribution, termed quadriceps-sparing myopathy (QSM), was later found in Jews originating from other Middle Eastern countries as well as in non-Jews. We previously localized the gene causing HIBM in Middle Eastern Jews on chromosome 9p12-13 (ref. 5) within a genomic interval of about 700 kb (ref. 6). Haplotype analysis around the HIBM gene region of 104 affected people from 47 Middle Eastern families indicates one unique ancestral founder chromosome in this community. By contrast, single non-Jewish families from India, Georgia (USA) and the Bahamas, with QSM and linkage to the same 9p12-13 region, show three distinct haplotypes. After excluding other potential candidate genes, we eventually identified mutations in the UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (GNE) gene in the HIBM families: all patients from Middle Eastern descent shared a single homozygous missense mutation, whereas distinct compound heterozygotes were identified in affected individuals of families of other ethnic origins. Our findings indicate that GNE is the gene responsible for recessive HIBM.

Amino Acid Sequence↗

PubMed2001

A whole genome scan for quantitative trait loci affecting milk protein percentage in Israeli-Holstein cattle, by means of selective milk DNA pooling in a daughter design, using an adjusted false discovery rate criterion.

Selective DNA pooling was employed in a daughter design to screen all bovine autosomes for quantitative trait loci (QTL) affecting estimated breeding value for milk protein percentage (EBVP%). Milk pools prepared from high and low daughters of each of seven sires were genotyped for 138 dinucleotide microsatellites. Shadow-corrected estimates of sire allele frequencies were compared between high and low pools. An adjusted false discovery rate (FDR) method was employed to calculate experimentwise significance levels and empirical power. Significant associations with milk protein percentage were found for 61 of the markers (adjusted FDR = 0.10; estimated power, 0.68). The significant markers appear to be linked to 19--28 QTL. Mean allele substitution effects of the putative QTL averaged 0.016 (0.009--0.028) in units of the within-sire family standard deviation of EBVP% and summed to 0.460 EBVP%. Overall QTL heterozygosity was 0.40. The identified QTL appear to account for all of the variation in EBVP% in the population. Through use of selective DNA pooling, 4400 pool data points provided the statistical power of 600,000 individual data points.

Alleles↗

PubMed2001

Observations on a new collagen barrier membrane in 16 consecutively treated patients. Clinical and histological findings.

BACKGROUND: Space-maintaining capacity, cell disclusive potential, and stability over time are crucial factors to achieving sufficient bone augmentation with membrane barriers. The case series presented here assessed a new collagen barrier used in bone augmentation. Clinically, the healing pattern, especially in cases of secondary healing, was studied. METHODS: Soft tissue healing was documented by photographs, and the size of the dehiscences calculated by image analysis. The measurements were performed on digitized photographs. During reentry, barrier remnants were dissected and histologically evaluated. RESULTS: The mean value for dehiscences was 35.5 mm2; all dehiscences healed within 4 weeks after the exposure became evident. The difference was statistically significant between the week 2 and week 6 visits (P = 0.008) for each previously exposed site. The histologic observation of barrier remnants revealed direct apposition of fibrous and bone tissues on the membrane surface. CONCLUSION: In cases of membrane exposure, gingival dehiscences always disappeared in the following weeks without affecting the healing process. Histologic results showed barrier stability over a 6-month period, promoting bone regeneration.

Adult↗

PubMed2000

A novel technique for monitoring the development of bacterial biofilms in human periodontal pockets.

A new technique is presented for analyzing subgingival bacterial plaque. Different materials (polytetrafluoroethylene, gold, dentin) kept for several days in periodontal pockets of patients suffering from periodontitis were analyzed by electron microscopy and fluorescence in situ hybridization (FISH). Those parts of the carriers extending into the deepest zone of the pockets were predominantly colonized by spirochetes and Gram-negative bacteria whereas those segments in contact with a shallower region were colonized by streptococci. Independent of the material used, the bacterial colonization of the carriers appears to be similar. FISH using eubacteria- and species-specific oligonucleotides on semi-thin cross-sections of the carriers in combination with confocal laser scanning microscopy allowed detailed analysis of the architecture of biofilms and identification of putative periodontal pathogens with single cell resolution.

Bacteria↗

PubMed2000

The age of onset of schizophrenia and the theory of anticipation.

The clinical phenomenon called anticipation is usually defined as a decrease in age at onset and/or an increase in disease severity in successive generations of afflicted families. The purpose of this study was to examine variables that might influence anticipation in schizophrenia. A total of 380 Austrian patients, born between 1935 and 1964, met criteria for schizophrenia with ICD-8 or ICD-9, SADS-L and DSM-III-R criteria. The inclusion criteria also required medical records of patients to contain information about the year of birth, season of birth, age at onset, accidents or meningoencephalitic diseases during childhood, first- and second-degree relatives afflicted with schizophrenia, sibship size, sib order, education of patient, age of parents, occupation of parents, loss of parents, and place of residence. A Cox multiple-regression analysis showed three factors as having a significant influence on the age of disease onset, including year of birth (which had the largest influence), family history (sporadic cases showed an onset 2 years later than familial cases) and residence (urban dwellers showed psychotic symptoms approximately 1 year sooner than rural ones). A Kaplan-Meier Survival Analysis showed that younger cohorts had onset approximately 10 years earlier in sporadic and familial cases. This cohort effect might be a major source of bias in studies of anticipation.

Adult↗

PubMed2000

Physicochemical properties of harpagoside and its in vitro release from Harpagophytum procumbens extract tablets.

The objective of this investigation was to characterize the active-component harpagoside of Harpagophytum extract from a physico-chemical perspective and to determine its in-vitro release from tablets according to DAB 1996. It was found that both pure harpagoside and harpagoside in Harpagophytum extract have an octanol-water distribution coefficient of approximately 4 which is neither dependent on temperature nor on pH. The mean harpagoside content in Harpagophytum tablets of Batch 9102 was 16.4 mg (S.D. 0.2; S.E. 0.03). Related to a tablet weight of 365 mg (100%), this corresponds to a haragoside content of 4.5% (S.D. 0.049; S.E. 0.006). On average the tablets disintegrate after 18 +/- 3 minutes (mean +/- SD). The tablets taken from Batch 9102 released the active component harpagoside well, with a t50 of 13.5 min, a t90 of 23 min and a t95 of 25 min in relation to 16.5 mg of harpagoside per dose. Harpagoside content decreased by about 10% in artificial gastric fluid within a period of 3 hours and remained stable in artificial intestinal fluid for a period of 6 hours.

Analgesics↗

PubMed2000

Attitude towards prophylactic surgery and effects of genetic counselling in families with BRCA mutations. Austrian Hereditary Breast and Ovarian Cancer Group.

The intent of this study was to evaluate the effect that an awareness of being a BRCA1 or BRCA2 mutation carrier has on the attitude towards prophylactic surgery and on developing depression symptoms. Thirty-five families were selected on the basis of previously detected BRCA1 or 2 mutations and 90 family members were given the appropriate questionnaires. Prophylactic mastectomy (PM) was considered by 21% of the Austrian mutation carriers (29% affected and 8% non-affected carriers). The majority of affected and non-affected carriers expected PM to impair the quality of their life. Fifty per cent would undergo prophylactic oophorectomy (53% affected and 46% non-affected carriers). The self-rating depression scale indicated that following mutation result disclosure the depression scores of carriers decreased (40 baseline vs 38 after result disclosure, P = 0.3), whereas, for non-carriers, scores increased (36 baseline vs 40 after result disclosure, P = 0.05). We conclude that information about carrier status is not associated with increased depression symptoms in mutation carriers. In non-carriers, depression scores increased slightly, probably reflecting survivor guilt. The option of having PM was associated with a negative impact on the quality of life and was declined by the majority of Austrian mutation carriers.

Adult↗

PubMed2000

X inactivation-specific transcript expression in mouse oocytes and zygotes.

Expression of the X inactivation-specific transcript (XIST:) gene has previously been shown by reverse transcription-polymerase chain reaction (RT-PCR) to be present at the 4-cell stage of female mouse embryos. This early expression, which is followed by X inactivation in the extra-embryonic tissues, is maternally imprinted. By the blastocyst stage, as the embryonic lineages begin to form, the imprint is lost and expression becomes random. By applying in-situ RT-PCR, we showed that XIST: is expressed even earlier in development, in unfertilized mouse oocytes as well as in pronuclei stage zygotes. Our data demonstrate XIST: expression in oocytes and suggest that XIST: transcripts may occur in both XX and XY zygotes. A difference in the pattern of expression (rod-like or rounded punctate signal) is found among pronuclear-stage embryos. Early expression is in agreement with findings reported in human embryos.

Animals↗

PubMed2000

KorSA from the Streptomyces integrative element pSAM2 is a central transcriptional repressor: target genes and binding sites.

pSAM2, a 10.9-kb mobile integrative genetic element from Streptomyces ambofaciens, possesses, as do a majority of Streptomyces conjugative plasmids, a kil-kor system associated with its transfer. The kor function of pSAM2 was attributed to the korSA gene, but its direct role remained unclear. The present study was focused on the determination of the KorSA targets. It was shown that KorSA acts as a transcriptional repressor by binding to a conserved 17-nucleotide sequence found upstream of only two genes: its own gene, korSA, and pra, a gene positively controlling pSAM2 replication, integration, and excision. A unique feature of KorSA, compared to Kor proteins from other Streptomyces conjugative plasmids, is that it does not directly regulate pSAM2 transfer. KorSA does not bind to the pSAM2 genes coding for transfer and intramycelial spreading. Through the repression of pra, KorSA is able to negatively regulate pSAM2 functions activated by Pra and, consequently, to maintain pSAM2 integrated in the chromosome.

Base Sequence↗

PubMed2000

The CD44 receptor of the mouse LB T-cell lymphoma: analysis of the isoform repertoire and ligand binding properties by reverse-transcriptase polymerase chain reaction and antisense oligonucleotides.

CD44 is a cell surface glycoprotein involved in cell migration and cell docking in target organs via interactions with various ligands, including hyaluronic acid (HA), which is the principal ligand of this receptor. Alternative splicing generates many isoforms of CD44, including standard CD44 (CD44s) and CD44 variants (CD44v). LB T-cell lymphoma, which predominantly expresses CD44s, acquires additional CD44v and HA binding capacity after activation with phorbol ester. The HA9 cell line, isolated from parental LB cells, expresses CD44v and constitutively binds HA. Downregulation of CD44v isoforms of HA9 cells, by CD44v specific antisense inhibited their ability to bind HA, indicating that CD44v, rather than CD44s, is associated with the activation status of this molecule. Using the reverse transcriptase polymerase chain reaction, we found that LB cells after infiltrating spleen and lymph nodes of BALB/c mice, contain an enriched repertoire of CD44v, implying that the metastatic cells acquired the activated form of this receptor.

Animals↗

PubMed1999

Neuroelectric assessment of nutrient intake.

Electroencephalographic (EEG) activity and auditory event-related brain potentials (ERPs) were assessed in two groups (n = 12 each) of subjects. The 'food-nutrient' group had fasted from the night before and consumed a 500 cal nutrient drink; the 'control' group consumed breakfast but did not consume any nutrients during the recordings. All subjects were assessed every 15 min for six trial blocks at the same time of day, with the fast/nutrient group measured initially before and after consuming the nutrient drink. No effects of the nutrient drink were obtained on the post-stimulus EEG spectral power or mean frequency measures. However, the fast/nutrient group demonstrated less delta, theta, and alpha-1 power than the no-fast/control group. Increases in spectral power were generally observed across trial blocks especially for the alpha and beta bands, and are consistent with increases in arousal level. P300 amplitude was unaffected by the nutrient consumption, but target stimulus N100 amplitude was smaller for the food-nutrient compared to the control group. Taken together, the results suggest that nutrient consumption does not directly affect EEG or cognitive ERP measures.

Adolescent↗

PubMed1999

A shared TCR CDR3 sequence in NOD mouse autoimmune diabetes.

T cells involved in autoimmune diseases have been characterized by the genetic elements used to construct their autoimmune TCR. In the present study, we sequenced the alpha and beta chains of the TCR expressed by a CD4(+) T cell clone, C9, functional in NOD mouse diabetes. Clone C9 can adoptively transfer diabetes or, when attenuated, C9 can be used to vaccinate NOD mice against diabetes. Clone C9 recognizes a peptide epitope (p277) of the 60 kDa heat shock protein (hsp60) molecule. We now report that the C9 TCR beta chain features a CDR3 peptide sequence that is prevalent among NOD mice. This CDR3 element is detectable by 2 weeks of age in the thymus, and later in the spleen and in the autoimmune insulitis. Thus, a TCR CDR3beta sequence appears to be a common idiotope associated with mouse diabetes.

Amino Acid Sequence↗

PubMed1998

Quantitative trait locus mapping in dairy cattle by means of selective milk DNA pooling using dinucleotide microsatellite markers: analysis of milk protein percentage.

"Selective DNA pooling" accomplishes quantitative trait locus (QTL) mapping through densitometric estimates of marker allele frequencies in pooled DNA samples of phenotypically extreme individuals. With poly(TG) microsatellites, such estimates are confounded by "shadow" ("stutter") bands. A correction procedure was developed on the basis of an observed linear regression between shadow band intensity and allele TG repeat number. Using this procedure, a selective DNA pooling study with respect to milk protein percentage was implemented in Israel-Holstein dairy cattle. Pools were prepared from milk samples of high and low daughters of each of seven sires and genotyped with respect to 11 markers. Highly significant associations with milk protein percentage were found for 5 of the markers; 4 of these markers confirmed previous reports. Selective DNA pooling accessed 80.6 and 48.3%, respectively, of the information that would have been available through individual selective genotyping or total population genotyping. In effect, the statistical power of 45,600 individual genotypings was obtained from 328 pool genotypings. This methodology can make genome-wide mapping of QTL accessible to moderately sized breeding organizations.

Animals↗

PubMed1998

Replicase, excisionase, and integrase genes of the Streptomyces element pSAM2 constitute an operon positively regulated by the pra gene.

pSAM2 is a site-specific integrative element from Streptomyces ambofaciens. The pra gene described earlier as an activator of pSAM2 replication is shown here to be also involved in the activation of its integration and excision. This was evidenced with derivatives of pSAM2 mutant B3 in which the pra gene was placed under the control of the inducible tipAp promoter. Transformation of Streptomyces lividans by these derivatives was efficient only when pra expression was induced, indicating its involvement in pSAM2 integration activation. Once established, these constructions remained integrated in the chromosome under noninduced conditions. Activation of the pra expression provoked strong activation of their excision, leading to the appearance of free forms. The results of functional, transcriptional, and sequence analyses allowed to conclude that the three genes repSA, xis, and int coding for the pSAM2 replicase, excisionase, and integrase, respectively, constitute an operon directly or indirectly activated by pra.

Base Sequence↗

PubMed1997

Complete conversion of antibiotic precursor to pristinamycin IIA by overexpression of Streptomyces pristinaespiralis biosynthetic genes.

A Streptomyces pristinaespiralis strain, which produces a streptogramin antibiotic pristinamycin II (PII) as a mixture of two biologically active molecules PIIB and PIIA, was genetically engineered to produce exclusively PIIA. The snaA,B genes, which encode a PIIA synthase that performs oxidation of the precursor (PIIB) to the final product (PIIA), were integrated in the chromosome of S. pristinaespiralis using an integrative derivative of the pSAM2 genetic element from Streptomyces ambofaciens. Integration was due to site-specific recombination at the attB site of S. pristinaespiralis, and no homologous recombination at the snaA,B locus was observed. The attB site of S. pristinaespiralis was sequenced and found to overlap the 3' end of a pro-tRNA gene. The integrants were stable in industrial conditions of pristinamycin production and showed no decrease in PII biosynthesis. Western blot analysis showed a constant production of the PIIA synthase in the overall fermentation process due to expression of the cloned snaA,B genes from the constitutive ermE promoter. This allows the complete conversion of the PIIB form into PIIA.

Attachment Sites, Microbiological↗

PubMed1996

The immunology of bullous oculo-muco-cutaneous disorders.

In skin-blistering diseases, alteration of cellular adhesion results in a loss of cohesion of the epithelium of the skin and the mucous membranes. These disorders are often genetically determined and involve highly specific autoantibodies. A recent workshop discussed the immunology of these diseases.

Eye Diseases↗

PubMed1996

RhD genotype determination by single sperm cell analysis.

OBJECTIVE: An Rh-negative woman with preexisting anti-D antibodies may affect some or all subsequent fetuses, depending on the genotype of her Rh-positive partner. Currently, a reliable technique for an absolute determination of RhD genotype is not available. This study was initiated to develop an accurate method for RhD genotyping in men. STUDY DESIGN: RhD genotype was determined by deoxyribonucleic acid amplification of a D-specific sequence in single sperm cell samples. Micromanipulation techniques were used for sampling of single sperm cells, which were further amplified by multiplex nested polymerase chain reaction at the RhD locus. A RhD sequence amplification product was expected in all of the successfully amplified samples from Rh-positive homozygotes, in some of the samples from heterozygotes, and in none of the samples form Rh-negative subjects. RESULTS: RhD genotype was accurately determined in 10 of 10 donors. A total of 132 single sperm cells were analyzed (8 to 17 samples per donor), of which 96 were successfully amplified as assessed by an internal control. As expected, the specific region of the RhD gene was amplified in all, some, and none of the signal-positive sperm samples from Rh-positive homozygotes, heterozygotes, and Rh-negative subjects, respectively, allowing accurate determination of the genotype. CONCLUSION: An accurate diagnosis of the RhD genotype can be attained from single sperm cell analysis by means of polymerase chain reaction and may have major clinical applications in the management of Rh isoimmunization.

Base Sequence↗