A Bbeta 14 Arg --> Cys fibrinogen variant in a patient with thrombotic complications (fibrinogen St-Germain III).
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Publications and source records attributed to P de Mazancourt.
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We sequenced the adhesin-cell wall-anchoring domain of the atlE gene of 49 invasive and commensal Staphylococcus epidermidis strains. We identified 22 alleles, which could be separated into two main groups: group 1 (alleles 1 and 6 to 16, 32/49 strains) and group 2 (alleles 2 to 5 and 17 to 22, 17/49 strains). Allele 1 (the type strain sequence) was by far the most prevalent (21 of 49 strains). Multilocus sequence typing showed a clear relationship between the atlE allele and the sequence type (ST), with the "nosocomial" ST27 clone and closely related STs expressing group 1 alleles.
A total of 212 coagulase-negative Staphylococcus strains recovered prospectively during 119 surgeries for proven or suspected bone and joint infection (BJI) were identified by sodA sequencing. These strains were identified as 151 Staphylococcus epidermidis isolates, 15 S. warneri isolates, 14 S. capitis isolates, 9 S. hominis isolates, 6 S. lugdunensis isolates, 5 S. haemolyticus isolates, 4 S. caprae isolates, 4 S. pasteuri isolates, 3 S. simulans isolates, and 1 S. cohnii isolate. Only S. epidermidis, S. lugdunensis, S. capitis, and S. caprae were found to be infecting organisms and were involved, respectively, in 35 (81.4%), 3 (7.0%), 3 (7.0%), and 2 (4.6%) cases of BJI.
This study evaluated the possible advantages provided by a genotypic method over commercially available biochemical systems for the identification of clinical isolates of coagulase-negative staphylococci (CNS). Partial sequencing of the sodA gene was performed for 168 coagulase-negative clinical isolates of staphylococci identified previously with the ID32 STAPH system. Of these, 101 (60.1%) were identified to the species level with ID32 STAPH, while 67 (39.9%) were misidentified or not identified with certainty. Sequencing of sodA proved useful for resolving all ambiguities or inconclusive identifications generated by the commercially available biochemical identification system.
Identification of spermatozoa is the biological evidence most often sought in specimens from rape victims. Absence of spermatozoa usually terminates biological investigations, and the victim's testimony can be contested. We assessed the utility and reliability of PCR amplification using Y-chromosomal STR polymorphisms in specimens from female victims of sexual assault with negative cytology. One hundred and four swabs without spermatozoa detected by cytology were collected from 79 alleged sexually assaulted female victims and amplification of Y-STR and of amelogenin was performed.Overall, Y-chromosome was detected and evidenced sexual penetration in 28.8% of swabs. In the population of victims examined more than 48 h after the sexual assault, Y-STR were still evidenced in 30% of the cases. These results show that swabs should be taken from victims for Y-chromosome DNA typing even after long delays between sexual assault and medical examination.
Male phenotype associated with a 45,X karyotype is an infrequent finding. We present a case diagnosed prenatally on amniocentesis performed for maternal age. The male phenotype was associated with a translocation of a distal part of Yp including the pseudoautosomal SHOX gene and SRY gene on the short arm of a chromosome 21. By DNA analysis we could show that the X chromosome was of maternal origin and that the breakpoint was in interval 3 of the Y chromosome. Mechanisms and genetic counselling are discussed based on a review of published cases of 45,X and XX males.
A fibrinogen variant was suspected based on the results of routine coagulation tests in a 2-year-old asymptomatic child. Coagulation studies showed marked prolongation of both the thrombin and reptilase times, and discrepancy was noted between the level of plasma fibrinogen as measured by a kinetic versus immunological determination. Family studies revealed that the father beared the same abnormality. Studies of purified fibrinogen revealed an impaired release of both fibrinopeptides by thrombin. Fibrin monomer polymerization and fibrin stabilization were normal. DNA sequencing revealed a heterozygous G --> T point mutation in exon 2 of the gene coding for the Aalpha chain, which substituted a Gly for Val at position 12. Although the mutation is the same as in fibrinogen Rouen, fibrinogen Saint-Germain I shows a different fibrinopeptide release pattern and a mild factor V deficiency.
Double heterozygosity for factor V R506Q and prothrombin G20210A mutations was identified in a 24-year-old man with beta-thalassemia major. The patient experienced a first thrombotic event at the age of 19 years and three recurrent thromboses in a short time interval, the third occurring while the patient was receiving long-term anticoagulant treatment. This case suggests that patients with major thalassemia and congenital thrombophilic mutations need intensive and long-lasting anticoagulant treatment. Thus, even if thrombotic events could be explained by a hypercoagulable state observed in patients with major thalassemia, after a first thrombotic event has occurred these patients should be screened for acquired and congenital thrombophilia.
We describe the successful identification of the remains of a saponified body found in a dam by typing of nuclear DNA. Whereas DNA extracted from soft tissues yielded negative PCR results, DNA extracted from the bone by a slightly modified Qiagen procedure allowed the typing of sex (AMG locus) and of 10 additional STR loci. An identity document was found belonging to a man missing for 3 years and comparison of the results to the DNA profiles of his son and wife confirmed the identity. The longest delay reported until now for successful nuclear DNA genotyping after immersion in river water was 18 months. This case demonstrates a delay of up to 3 years.
Adenylyl cyclase catalytic activity is low in preadipocyte membranes when compared to adipocytes. Under conditions promoting inhibition of adipocyte adenylyl cyclase activity by Gpp(NH)p, a stable GTP analog, a paradoxical increase in preadipocyte adenylyl cyclase activity was obtained. In order to explain this contradiction, expression of types II, IV, V and VI adenylyl cyclase isoforms was compared in adipocytes and undifferentiated preadipocytes both by western blots and by a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) assay. Type II, IV, V and VI mRNAs and proteins were present in both adipocytes and preadipocytes. However, in undifferentiated preadipocytes, expression of type II mRNA and protein were significantly higher whereas expression of type IV, V and VI adenylyl cyclase mRNAs and proteins were significantly weaker than in adipocytes. In late differentiated preadipocytes, the adenylyl cyclase subtype mRNA expression pattern was intermediary between the undifferentiated and the full differentiation states except for type IV which remained weakly expressed. Moreover, one of the representative regulators of G-protein signaling (RGS protein), RGS4, was less expressed in undifferentiated preadipocyte membranes and cytosol extracts, which contrasts with adipocytes where RGS4 is clearly expressed. Thus, the preferential expression of type II adenylyl cyclase (G(betagamma) subunit-stimulated) in preadipocytes might explain why Gpp(NH)p elicits stimulation of adenylyl cyclase under conditions designed to promote inhibition. Conversely, the preferential expression of type V and VI adenylyl cyclases and the slightly higher expression of type IV adenylyl cyclase in adipocytes could contribute to explain the elevated total catalytic activity observed in mature fat cells compared to their precursor cells.
In order to identify unknown mutations, the FAMA method was used to rapidly screen the fibrinogen chain genes in individuals with dysfibrinogenemias. Chemical cleavage at mismatches on heteroduplexes DNA end-labeled with strand-specific fluorescent dyes reliably detects sequence changes in DNA fragments of up to 1.5 kb and locates them precisely. This method was successfully used for the detection of three new dysfibrinogenemias: Poissy III, Tahiti (heterozygous Aalpha Arg16His) and Saint-Germain I (heterozygous AalphaGly12Val). The mutations were confirmed by dideoxy sequencing.
INTRODUCTION: Cutaneous necrosis occurring in the course of treatment by alpha interferon is an uncommon side-effect. Its physiopathologic mechanism remains obscure. A local thrombotic action of interferon has been suggested to explain its occurrence. EXEGESIS: A 64-year-old male patient with human immunodeficiency virus-related cutaneous Kaposi's sarcoma presented cutaneous necrosis after a 9-month treatment by interferon alpha, while his resistance to activated protein C had already been demonstrated. To our knowledge, this is the first case ever described regarding the association of interferon-induced cutaneous necrosis with activated protein C resistance. CONCLUSION: This suggests that in case of interferon treatment-induced cutaneous necrosis coagulation disorders should be investigated and questions the existence of a particular "pro-coagulant profile" facilitating this side effect.
Adipose tissue is an important source of angiotensinogen (ATG), and hypertension is commonly associated with android obesity. Therefore, we tested the hypothesis that androgens may control ATG gene expression and secretion in rat fat cells. In intact male rats, ATG mRNA expression (Northern blot and co-reverse transcription-polymerase chain reaction analysis) and protein secretion were significantly higher in deep intra-abdominal (perirenal and epididymal) than in subcutaneous adipocytes. After castration, ATG mRNA was reduced almost 50% in the three fat deposits, with parallel changes in ATG protein secretion. Conversely, testosterone treatment fully restored the ATG mRNA decrease after castration, whatever the anatomical origin of the adipocytes. Finally, a 24-h in vitro exposure of perirenal fat cells or differentiated preadipocytes from castrated rats to testosterone or dihydrotestosterone (10 nM free hormone concentration) increased ATG mRNA expression by 50-100%, an effect that was prevented by the anti-androgen cyproterone acetate. These data, demonstrating both in vivo and in vitro androgen induction of ATG mRNA expression in rat adipocytes, add further weight to the hypothesis of a link between adipose tissue ATG production, androgens, and android obesity-related hypertension.
We describe a method combining in a single-round polymerase chain reaction amplifications of both cytochrome b and hypervariable D-loop mitochondrial DNA allowing species determination and individual human identification. Following the amplification step, amplicons are first screened on an agarose gel. The presence of only one band indicates that the sample is nonhuman, while the presence of two bands indicates a human origin. Subsequent DNA sequencing of the hypervariable D-loop region DNA allows for individual human identification as the presence of cytochrome b fragment does not interfere with the analysis. Similarly, further species determination on the basis of the phylogenetically variable cytochrome b gene is possible by sequencing of the cytochrome b DNA fragment.
Antibodies to alpha and beta subunits of guanine nucleotide regulatory proteins (G proteins) were used to identify which G proteins are present in mature human spermatozoa and to determine their subcellular localization. Immunoblots of membranes from spermatozoa demonstrate the presence of Galphai2, Galphai3, Galphaq/11 and Gbeta35 and the absence of Galphai1, Galpha0, Galphas, Galpha12, Galpha13, Galpha16, Galpha and Gbeta36. Indirect immunofluorescence demonstrates the presence of Galphaq/11 in the acrosome, with the highest proportion in the equatorial segment. Galphai2 is present in the acrosome, midpiece and tailpiece and Galphai3 in the postnuclear cap, midpiece and tailpiece. The Gbeta35 subunit is found mostly in the midpiece, with marginal labelling of the head, tailpiece and the equatorial segment of the acrosome. The distinct pattern of distribution of G proteins suggests that they may couple to receptors or effectors which also have discrete regions of localization in spermatozoa. These highly localized signal transduction pathways may regulate discrete functions, such as activation of the acrosome reaction, fusion with the oocyte and motility.
The SMN1 gene is homozygously deleted for at least exon 7, interrupted or converted to a non-functional telomeric copy in most cases of proximal spinal muscular atrophies. The presence of a pseudogene hampers direct detection of the exon 7 deletion. We describe a method for the detection of the of exon 7 deletion, based on the amplification refractory mutation system (ARMS), in a multiplex PCR with fluorescent-labelled primers. The gene and pseudogene amplification products differ in the dye bound and in their size, which allows distinction of both products on electrophoresis. The pseudogene is used as an internal control, and this method gives a clear and specific pattern for the patients. Amplification is achieved with 30 cycles, and specificity is retained up to 40 cycles.
A simple method is reported here for the semi-quantitative assay of mRNAs in the presence of an exogenous mRNA (pBR322 transcript) as a standard. This method uses the co-reverse transcription and co-amplification (co RT-PCR) of the target and standard mRNAs. This procedure enables transcripts to be compared when the differentiation process affects the transcription pattern of the beta-actin housekeeping gene, a commonly used internal standard. This method is sensitive and avoids constructing internal competitive RNA standards. As an example, it is shown that beta-actin transcription decreases and type V adenylyl cyclase transcription increases in adipocytes, when compared to preadipocytes.