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Biomedical subjects

F Denis

Publications and source records attributed to F Denis.

At least 37 records · Page 2Linked to original sources

Real-time PCR for quantification of human herpesvirus 6 DNA from lymph nodes and saliva.

A real-time quantitative PCR assay has been developed to measure human herpesvirus 6 (HHV-6) DNA in biological specimens. The assay sensitivity was 10 copies of DNA per well, with a linear dynamic range of 10 to 10(7) copies of HHV-6 DNA. Intra- and interassay variations were, respectively, 0.88 and 0.8% for samples containing 10(2) DNA copies, 0.99 and 0.96% for samples containing 10(4) copies, and 0.76 and 0.9% for samples containing 10(6) copies. Among 34 saliva samples from healthy subjects, 26 were found to contain HHV-6 DNA (76.5%; median, 23,870 copies/ml), and following a single freeze-thaw cycle, 25 of the same samples were found to be positive for HHV-6 DNA, although at a statistically significantly lower concentration (median, 3,497 copies/ml). The assay enabled detection of HHV-6 DNA in lymph node biopsies from patients with Hodgkin's disease (HD) (13 of 37 patients [35.1%]), B-cell neoplasms (8 of 36 patients [22.2%]), and T- or NK-cell neoplasms (3 of 13 patients [23.1%]), with concentrations ranging from 100 to 864,640 HHV-6 copies per microg of DNA (HHV-6B being found in every case except two). All HD patients infected with HHV-6 presented clinically with the nodular sclerosis subtype of HD. The real-time quantitative PCR assay developed here was simple to perform and was sensitive over a wide range of HHV-6 concentrations. It therefore appears to be of potential value in clinical investigation or diagnosis of HHV-6 infection.

Adult↗

Reactivation of human herpesvirus type 6 in multiple organ failure syndrome.

Human herpesvirus type 6 (HHV-6) and cytomegalovirus (CMV) are known to interact with the production of cytokines. In this study, we sought to determine the incidence of HHV-6 and CMV reactivation during multiple organ failure syndrome (MOFS) and to evaluate the potential effects of viral replication on both the morbidity and mortality associated with MOFS. Viral reactivation was assessed by use of specific polymerase chain reaction (PCR) analysis of the serum samples obtained from 48 consecutive patients with MOFS (the MOFS group) and from 48 sex- and age-matched patients with <2 organ failures (the control group). In addition, HHV-6 replication was assessed in 106 blood donors (the normal group). The incidence of HHV-6 replication was higher in the MOFS group than in the control and normal groups (26 [54%] of 48 vs. 7 [15%] of 48 and 5 [5%] of 106, respectively; P<.0001), with apparently no influence on morbidity and mortality rates. In contrast, reactivation of CMV was found in a single patient. Further studies are needed to evaluate the pathogenesis of HHV-6 replication in critically ill patients.

Adolescent↗

Extension of fusions to the pelvis in idiopathic scoliosis.

STUDY DESIGN: Retrospective study of patients after extension of previous scoliosis fusions to the pelvis. OBJECTIVE: To determine whether modern instrumentation and surgical techniques provide for increased fusion rates with fewer complications. SUMMARY OF BACKGROUND DATA: Traditionally, long fusions to the pelvis in adults with idiopathic scoliosis have resulted in high complication rates, including pseudarthrosis. METHODS: The hospital and clinic charts of 41 patients (40 female, 1 male) were reviewed 41 months (range: 24-116) after surgery for extension to the pelvis of previous scoliosis fusions. Thirty-nine of 41 had a combined anteroposterior fusion extension; two had posterior extension only. In 37 of 41 patients, Cotrel-Dubousset (CD) instrumentation was used; in two, Isola (Acromed Corp., Cleveland, OH), in one, TSRH; (Sofamor-Danek, Memphis, TN), and in one, Synergy (Cross Medical Products, Columbus, OH). Parameters analyzed were fusion rate, sagittal and coronal balance, lumbar lordosis, length of fusion extension, and distal fixation method. RESULTS: Complications were seen in 30 of 41 patients. The pseudarthrosis rate was 37% (15/41) and was significantly related to the method of distal posterior fixation. With sacral fixation only, the rate was 53% (8/15), with iliac fixation only 42% (3/7), and with both iliac and sacral fixation 21% (4/19; P < 0.05). This was not correlated with fusion rate, and the length of fusion extension did not affect the pseudarthrosis rate or sagittal balance. CONCLUSION: When fixed to the ilium and sacrum, modern instrumentation appears capable of maintaining sagittal balance with lower rates of pseudarthrosis when previous scoliosis fusions are extended to the pelvis. The complication rate remains significant.

Adult↗

Congenital HCMV infection: a collaborative and comparative study of virus detection in amniotic fluid by culture and by PCR.

Cytomegalovirus (HCMV) infection is the leading cause of congenital virus infection in developed countries, affecting an estimated 1% of births. This antenatal infection can cause serious sequelae. Strategies for prevention and treatment must, therefore, be agreed upon, entailing a preliminary performance assessment of antenatal virus diagnosis techniques. Between 1992 and 1999, HCMV serology status was established for 19456 pregnant women in four French hospitals. Seronegative patients (55.4%) were given serology screening, and antenatal diagnosis was given to 152 women who had shown seroconversion during their pregnancies (1.4%). The detection of HCMV transmission from mother to fetus was finally established in 95 cases, using polymerase chain reaction (PCR) and viral culture methods for detecting HCMV in the amniotic fluid. These results were compared with viral culture of children's urine after birth, enabling us to distinguish between children really infected in utero (30%) and non-infected children (70%). The results of the virus culture and those of PCR were identical in 94 of the 95 cases, with one discrepancy (culture-/PCR+). The two diagnosis techniques had identical sensitivity (72%), with culture proving slightly more specific than PCR (98.4% as opposed to 96.9%). Positive prediction values for culture and for PCR were, respectively, 95.6 and 91.3%. Antenatal virus diagnosis on amniotic fluid was negative with both techniques in 8 out of 29 cases of children born with HCMV infection (VPN=89%). Over half of these wrongly negative results can be explained by amniocentesis carried out too early in the pregnancy or too early with respect to the mother's primary infection.

Amniotic Fluid↗

[Erysipelas: microbiological and pathogenic data].

Streptococcus pyogenes is considered as the primary cause of erysipelas and the virulence factors of this species are reviewed. The role of Staphylococcus aureus alone or associated with Streptococcus pyogenes remains unclear. Other etiologies are infrequent. Several techniques were used to detect bacteria (direct examination, culture, antigen or genome assay) in local samples (needle aspiration, swab.), in others sites (throat, blood cultures), or specific antibodies. The performance of the various diagnosis methods is evaluated. Despite the combination of 2 or more methods, the etiology remains unknown in almost 20 p. 100 of the cases.

Erysipelas↗

Prevalence and characteristics of Sjögren's syndrome or Sicca syndrome in chronic hepatitis C virus infection: a prospective study.

OBJECTIVE: To describe the prevalence and clinical and laboratory characteristics of sicca syndrome and Sjögren's syndrome (SS) in chronic hepatitis C virus (HCV) infection. METHODS: Forty-five consecutive HCV infected patients referred for liver biopsy were enrolled in a prospective study. Subjective and objective criteria of xerophthalmia or xerostomia were systematically investigated and the patients classified according to 3 sets of criteria (European, Manthorpe, and Fox criteria) for the diagnosis of SS. RESULTS: Sicca syndrome was present in 28 (62%) patients; all had oral dryness and 14 had both oral and ocular dryness. Twenty-four (53%) patients had SS by the European criteria, 25 (56%) by Manthorpe criteria, and 4 (8%) by Fox criteria. Salivary gland biopsy was positive for SS (grade III or IV by Chishom classification) in 21 samples (47%); 9 samples (21%) were classified grade 0, and 15 (32%) grade I or II. No patient had anti-SSA or anti-SSB antibodies. The presence of SS or sicca syndrome was associated with older age and liver disease activity according to the METAVIR scoring system, but not with the presence of other extrahepatic manifestations or with HCV genotype. A high METAVIR activity score was only statistically associated with primary SS. CONCLUSION: HCV infection appears to account for a subgroup of patients with sicca syndrome in which half the cases meet the definition for SS according to European and Manthorpe criteria. This subgroup is characterized by the constant finding of xerostomia, the absence of classical systemic manifestations observed in primary SS, and the absence of anti-SSA or anti-SSB antibodies. Such characteristics delineate a distinctive, virus associated entity that differs from primary SS.

Adult↗

Molecular cloning and characterization of beluga whale (Delphinapterus leucas) interleukin-1beta and tumor necrosis factor-alpha.

Interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) are cytokines produced primarily by monocytes and macrophages with regulatory effects in inflammation and multiple aspects of the immune response. As yet, no molecular data have been reported for IL-1beta and TNF-alpha of the beluga whale. In this study, we cloned and determined the entire cDNA sequence encoding beluga whale IL-1beta and TNF-alpha. The genetic relationship of the cytokine sequences was then analyzed with those from several mammalian species, including the human and the pig. The homology of beluga whale IL-1beta nucleic acid and deduced amino acid sequences with those from these mammalian species ranged from 74.6 to 86.0% and 62.7 to 77.1%, respectively, whereas that of TNF-alpha varied from 79.3 to 90.8% and 75.3 to 87.7%, respectively. Phylogenetic analyses based on deduced amino acid sequences showed that the beluga whale IL-1beta and TNF-alpha were most closely related to those of the ruminant species (cattle, sheep, and deer). The beluga whale IL-1beta- and TNF-alpha-encoding sequences were thereafter successfully expressed in Escherichia coli as fusion proteins by using procaryotic expression vectors. The fusion proteins were used to produce beluga whale IL-1beta- and TNF-alpha-specific rabbit antisera.

Amino Acid Sequence↗

Coronal plane imbalance in adolescent idiopathic scoliosis with left lumbar curves exceeding 40 degrees: the role of the lumbosacral hemicurve.

STUDY DESIGN: Retrospective radiographic analysis of the potential role the lumbosacral hemicurve has on adolescent idiopathic scoliosis coronal trunk imbalance. OBJECTIVE: To determine if the lumbosacral hemicurve predisposes adolescent idiopathic scoliosis to coronal decompensation preoperatively and postoperatively. SUMMARY OF BACKGROUND DATA: Although coronal decompensation remains a clinical problem in adolescent idiopathic scoliosis, the literature regarding the role of potential intrinsic structural properties of the lumbosacral hemicurve is sparse. METHODS: Fifty patients with adolescent idiopathic scoliosis were used to measure several potential parameters predisposing to coronal decompensation including lumbosacral hemicurve magnitude and flexibility, sacral and iliac obliquity. RESULTS: Overall, 84% (42/50) demonstrated preoperative decompensation. A more rigid lumbosacral hemicurve was significantly related to preoperative coronal decompensation in the combined and the King I groups. Preoperatively, significant correlation with decompensation was observed for sacral and iliac obliquity in the King I group and for iliac obliquity in the combined group. Postoperatively, coronal decompensation remained significantly correlated to sacral obliquity in the combined group and King I groups. Iliac obliquity was significantly related to postoperative decompensation in the combined group. CONCLUSIONS: The lumbosacral hemicurve represents an important structure predisposing to left coronal plane imbalance in adolescent idiopathic scoliosis that includes a large left lumbar curve as a component of the curve pattern. "At-risk" signs for persistent postoperative coronal decompensation include iliac and sacral obliquity noted on the preoperative standing full-length radiographs.

Adolescent↗

Activation of glial cells by human coronavirus OC43 infection.

Multiple sclerosis (MS) is an immune-mediated demyelinating disease that could be triggered by a viral infection. Coronaviruses induce an MS-like disease in rodents, are neuroinvasive in humans and can infect primary cultures of human astrocytes and microglia. Infection of the human astrocytic cell line U-373MG by the OC43 strain of human coronavirus caused an upregulation of IL-6, TNF-alpha, and MCP-1 mRNA expression. This virus also modulated the activity of matrix metalloproteinases-2 and -9 and augmented nitric oxide production in both U-373MG cells and the human microglial cell line CHME-5. Thus, a coronaviral infection of glial cells could lead to the production of inflammatory molecules that have been associated with central nervous system pathologies such as MS.

Astrocytes↗

A novel mutation in the alpha-helix 1 of the C subunit of the F(1)/F(0) ATPase responsible for optochin resistance of a Streptococcus pneumoniae clinical isolate.

Previously reported mutations involved in optochin resistance of Streptococcus pneumoniae clinical isolates changed residues 48, 49 or 50, in the transmembrane alpha-helix 2 of the F(1)/F(0) ATPase subunit. We report here an unusual mutation which changes the sequence of the transmembrane alpha-helix 1 of the AtpC subunit. This mutation involves a Gly to Ser substitution resulting from a G to A transition at codon 14 of the atpC gene.

Amino Acid Sequence↗

Estimation of the prevalence of epilepsy in the Benin region of Zinvié using the capture-recapture method.

BACKGROUND: The prevalence of epilepsy was estimated in two villages of 3134 inhabitants, in Benin, in April and May 1997 using the capture-recapture method. METHODS: Information was obtained from (i) a door-to-door cross-sectional study, (ii) a non-medical source consisting of key informants (traditional practitioners, teachers, village leaders, and religious representatives) and (iii) a medical source through evaluation of medical records in health centres. In all the three situations, the diagnosis of epilepsy was confirmed by a neurologist. RESULTS: The door-to-door survey found 50 epileptics, i.e. a prevalence of 15.9 per 1000. The non-medical source found 26 patients. The medical source found only four patients. In total, 66 epileptics were found by combining the three sources, giving a prevalence of 21.1 per 1000. After application of the capture-recapture method, the estimated number of cases from the door-to-door survey and non-medical source was 105, and 110 cases when the medical source was considered as well. The respective prevalences were 33.5 per 1000, and 35.1 per 1000. CONCLUSIONS: The door-to-door survey has been usefully improved by using key informants. The epilepsy prevalence estimate found by capture-recapture is clearly higher than that found by traditional cross-sectional methods, and could better depict the frequency of epilepsy in Africa.

Adolescent↗

Postoperative deep wound infection in adults after posterior lumbosacral spine fusion with instrumentation: incidence and management.

The authors reviewed 817 instrumented lumbosacral fusions in adults and found an incidence of 3.2% deep wound infections. The primary focus of this study was the management of these infections, with particular attention to whether the implants needed to be removed. A consulting infectious disease specialist indicated that an acute infection of a low back fusion wound could not be healed without removal of the metallic implants. This opinion was in contrast to the authors' daily experience and prompted this study. The authors identified and reviewed 817 cases of instrumented posterior lumbosacral arthrodeses in adults. A detailed analysis of any case with a deep wound infection was performed and yielded and infection rate of 3.2% (26 patients). Of these, 24 achieved a clean, closed wound without removal of instrumentation through a protocol of aggressive debridement and secondary closure. Instrumentation removal is not necessary to obtain a clean, closed wound using an aggressive approach with early diagnosis, vigorous debridement in the operative room under general anesthesia, delayed primary or secondary closure, and appropriate antibiotic coverage.

Acute Disease↗

Management of symptomatic lumbar pseudarthrosis with anteroposterior fusion. A functional and radiographic outcome study.

STUDY DESIGN: An independent retrospective review of 37 patients undergoing 39 anteroposterior lumbar fusions for lumbar pseudarthrosis repair between 1984 and 1990. OBJECTIVES: To evaluate radiographically and functionally the results of the combined anteroposterior fusion for the management of symptomatic lumbar pseudarthrosis, and to assess risk factors for functional failure after the procedure. SUMMARY OF BACKGROUND DATA: Most reported techniques of pseudarthrosis repair involve posterior fusion with no instrumentation, posterior fusion with instrumentation, or anterior fusion alone. The results of lumbar pseudarthrosis repair are poor. Fusion rates range from 30% to 70%, with only a 30% to 50% rate of functional success. METHODS: Thirty-nine procedures were assessed in 37 patients. The outcomes were assessed radiographically (solid fusion vs. pseudarthrosis) and functionally (success vs. failure). Radiographs were assessed at follow-up examination for consolidation of fusion anteriorly and posteriorly. Functional outcome was graded by using multiple instruments, including data from chart review and the follow-up outcome questionnaire. A functional failure score that took into account 10 items was developed. RESULTS: In this patient population (37 patients, 59% with a smoking history, 71% with compensation or legal claims), there was a 10% pseudarthrosis rate. Pseudarthrosis was defined when one or more levels were involved and when it occurred anteriorly and posteriorly. In 12 patients (35%), the outcome was rated as functional failure. The presence of one or more abnormal neurologic findings and significant narcotic use before surgery significantly increased the chance of a patient's outcome being functional failure. Workmen's Compensation or legal status before surgery also increased the chance of functional failure, though this correlation was not statistically significant. CONCLUSIONS: A combined anterior and posterior approach for the management of symptomatic lumbar pseudarthrosis is a viable alternative to posterior fusion alone. In fact, this procedure affords a higher fusion rate based on radiographic assessment. Functional failure rates may be decreased by using caution for those patients using narcotics regularly before surgery or in those with unexplained preoperative neurologic abnormal findings.

Adult↗

Molecular characterization of integrons in Acinetobacter baumannii: description of a hybrid class 2 integron.

Twenty Acinetobacter baumannii strains resistant to various antibiotics were analyzed for integron content and sequences of the amplification products. Sixteen clinical isolates had a class 1 integron, 2 contained an additional class 1 or class 2 integron, but no class 3 integron was detected. Thirteen strains had integrons with a single cassette: aac(3)-Ia (9 strains), ant(2")-Ia (2 strains), or aac(6')-Ib (2 strains); 1 had aac(6')-Ib and oxa20 cassettes and an unknown gene; and 1 had an integron containing ant(2")-Ia and an oxa3 cassette truncated by IS6100. The remaining strains harbored class 1 integrons with gene cassettes previously found in Enterobacteriaceae. One integron had a hybrid structure composed of intI2 and the 3' conserved segment of class 1 integrons. These data indicate that integrons play a major role in multidrug resistance in Acinetobacter.

Acinetobacter↗