Liver-related mortality in human-immunodeficiency-virus-infected patients between 1995 and 2003 in the French GERMIVIC Joint Study Group Network (MORTAVIC 2003 Study)

The objective of the present study was to determine mortality because of end-stage liver disease (ESLD) in a nationwide population of HIV-infected patients, 7 years following the introduction of highly active antiretroviral therapy (HAART). All departments of internal medicine and infectious diseases from the GERMIVIC Study Group prospectively recorded all deaths in HIV-infected patients during 2003. Fifty-nine departments, following a total of 20 940 HIV-infected patients, participated in the study. Results were compared with those of previous surveys conducted using similar methodology in 1995, 1997 and 2001. Among 215 deaths observed during 2003, 101 (46.9%) were related to AIDS, 27 (12.6%) to ESLD and 87 (40.5%) to other causes. Mortality because of ESLD represented 23.7% of non-AIDS-related deaths. Patients dying from ESLD had chronic hepatitis because of hepatitis C virus (HCV) in 92.6% of cases and moderate (30-60 g) or high (>60 g) alcohol consumption (43.5% and 26.0%, respectively). In this population, deaths because of ESLD were 1.5% in 1995, 6.6% in 1997, 14.3% in 2001 and 12.6% in 2003. The prevalence of hepatocellular carcinoma as a cause of death remained high in 2003 but stable when compared with 2001 (25%vs 14.8%). Treatment of hepatitis C in patients who died from ESLD was more frequent in 2003 (44.4%) than in 2001 (26.3%). Seven years after the introduction of HAART, ESLD associated with HCV infections is a leading cause of mortality in HIV-infected patients, which did not increase between the years 2001 and 2003.

Comparison of established and emerging biodosimetry assays

Rapid biodosimetry tools are required to assist with triage in the case of a large-scale radiation incident. Here, we aimed to determine the dose-assessment accuracy of the well-established dicentric chromosome assay (DCA) and cytokinesis-block micronucleus assay (CBMN) in comparison to the emerging γ-H2AX foci and gene expression assays for triage mode biodosimetry and radiation injury assessment. Coded blood samples exposed to 10 X-ray doses (240 kVp, 1 Gy/min) of up to 6.4 Gy were sent to participants for dose estimation. Report times were documented for each laboratory and assay. The mean absolute difference (MAD) of estimated doses relative to the true doses was calculated. We also merged doses into binary dose categories of clinical relevance and examined accuracy, sensitivity and specificity of the assays. Dose estimates were reported by the first laboratories within 0.3-0.4 days of receipt of samples for the γ-H2AX and gene expression assays compared to 2.4 and 4 days for the DCA and CBMN assays, respectively. Irrespective of the assay we found a 2.5-4-fold variation of interlaboratory accuracy per assay and lowest MAD values for the DCA assay (0.16 Gy) followed by CBMN (0.34 Gy), gene expression (0.34 Gy) and γ-H2AX (0.45 Gy) foci assay. Binary categories of dose estimates could be discriminated with equal efficiency for all assays, but at doses ≥1.5 Gy a 10% decrease in efficiency was observed for the foci assay, which was still comparable to the CBMN assay. In conclusion, the DCA has been confirmed as the gold standard biodosimetry method, but in situations where speed and throughput are more important than ultimate accuracy, the emerging rapid molecular assays have the potential to become useful triage tools.

Severe hepatic cytolysis: incidence and risk factors in patients treated by antiretroviral combinations. Aquitaine Cohort, France, 1996-1998. Groupe dEpidémiologie Clinique de Sida en Aquitaine (GECSA)

OBJECTIVE

To study hepatic cytolysis in patients treated by highly active antiretroviral therapy (HAART) with protease inhibitor or with two nucleoside reverse transcriptase inhibitors (NRTIs).

METHODS

We selected patients of the Aquitaine Cohort who initiated HAART or two NRTIs before 1 January 1998, had alanine amino-transferase (ALT) < or = 200 IU/I at baseline and at least one follow-up measure. Cox model was used to study the association between occurrence of severe hepatic cytolysis (ALT>200 IU/l) and age, gender, HIV transmission group, baseline CD4 and CD8 cell count, history of hepatic cytolysis, antiretroviral drug, baseline liver enzymes (WHO classification level 0: < or = 50 IU/l, level 1: 51 to 100, level 2: 101 to 200), hepatitis B and C co-infection.

RESULTS

Sixty-four of 748 (8.5%) patients treated with HAART and 71 of 1249 (5.7%) treated with two NRTIs developed cytolysis. The probability of occurrence was 7.9% after 1 year [95% confidence interval (CI), 5.9-10.4] for patients treated with HAART and 4.8% (95% CI, 3.6-6.4) for patients treated with two NRTIs (log-rank test, P = 0.01). The median time to occurrence was 164 days for HAART-treated patients and 252 days for those treated with two NRTIs. In multivariate analysis, the history of cytolysis [hazard ratio (HR) = 2.3; 95% CI, 1.2-4.4], baseline value of ALT (HR = 2.4; 95% CI, 1.2-4.8 and HR = 3.3; 95% CI, 1.4-7.4 for levels 1 and 2, respectively), hepatitis B (HR = 3.0; 95% CI, 1.4-6.2) and C co-infections (HR = 3.2; 95% CI, 1.7-6.2) remained significantly associated with the occurrence of severe hepatic cytolysis among HAART-treated patients. History of cytolysis, hepatitis B and C were associated with cytolysis in patients treated with two NRTIs (HR = 14.8, 2.6 and 2.7, respectively).

CONCLUSION

Hepatic cytolysis is more frequent among patients treated with HAART than with two NRTIs. Hepatitis B and C are the major risk factors after initiation of HAART or treatment with NRTIs. Co-infections with hepatitis B virus or hepatitis C virus may modify the management of HIV-infected patients treated by HAART.

Lead concentrations in feathers and blood of common blackbirds (Turdus merula) and in earthworms inhabiting unpolluted and moderately polluted urban areas

Despite the dramatic decrease of atmospheric lead (Pb) concentrations in urban areas of most industrialised countries, we hypothesised that urban common blackbirds (Turdus merula) may still be contaminated by Pb concentrations of toxicological concern due to transfer from soil through the food chain. We sampled blackbirds and earthworms, one of their main preys, in Besançon, a middle-size city of Eastern France (where atmospheric Pb concentrations decreased from 0.5 microg/m(3) in 1987 to nearly 0 in 2002) and in a rural reference site. Lead concentrations were determined in the tissues of the different functional groups of earthworms (anecic, epigeous and endogeous) and in blood, washed and unwashed outermost tail feathers and breast feathers of blackbirds. Fresh masses and an index of individual body condition were measured in the two blackbird populations as biomarkers of possible toxic effects. Lead concentrations in earthworms did not differ among functional groups but were significantly higher in urban individuals than in rural ones. Concentrations in outermost tail feathers, breast feathers and blood were significantly higher in urban blackbirds (7.75+/-4.50, 3.15+/-1.77 and 0.15+/-0.09 microg/g, respectively) than in rural individuals. In urban blackbirds, concentrations in washed and unwashed outermost tail feathers allowed estimating the external contamination (probably due to deposition of dusts and/or to excretion of the uropygial gland) at 37% of the total Pb concentration of the unwashed feathers. Remaining 63% should be linked to food chain transfer of persistent Pb from urban soils. Among the 23 sampled blackbirds, 4 of them (3 in the urban site and 1 in the rural site) exhibited blood Pb concentrations higher than the benchmark value (0.20 microg/g) related to subclinical and physiological effects in birds. Variations in body condition index were not correlated to Pb concentrations in blackbird tissues. Present results suggest that Pb may still be of environmental concern for blackbirds in urban areas because of the persistence of Pb in soils and its transfer through the food chain.

Lactobacillus plantarum ldhL gene: overexpression and deletion

Lactobacillus plantarum is a lactic acid bacterium that converts pyruvate to L-(+)- and D-(-)-lactate with stereospecific enzymes designated L-(+)- and D-(-)-lactate dehydrogenase (LDH), respectively. A gene (designated ldhL) that encodes L-(+)-lactate dehydrogenase from L. plantarum DG301 was cloned by complementation in Escherichia coli. The nucleotide sequence of the ldhL gene predicted a protein of 320 amino acids closely related to that of Lactobacillus pentosus. A multicopy plasmid bearing the ldhL gene without modification of its expression signals was introduced in L. plantarum. L-LDH activity was increased up to 13-fold through this gene dosage effect. However, this change had hardly any effect on the production of L-(+)- and D-(-)-lactate. A stable chromosomal deletion in the ldhL gene was then constructed in L. plantarum by a two-step homologous recombination process. Inactivation of the gene resulted in the absence of L-LDH activity and in exclusive production of the D isomer of lactate. However, the global concentration of lactate in the culture supernatant remained unchanged.

Knockout of the two ldh genes has a major impact on peptidoglycan precursor synthesis in Lactobacillus plantarum

Most bacteria synthesize muramyl-pentapeptide peptidoglycan precursors ending with a D-alanyl residue (e.g., UDP-N-acetylmuramyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala). However, it was recently demonstrated that other types of precursors, notably D-lactate-ending molecules, could be synthesized by several lactic acid bacteria. This particular feature leads to vancomycin resistance. Vancomycin is a glycopeptide antibiotic that blocks cell wall synthesis by the formation of a complex with the extremity of peptidoglycan precursors. Substitution of the terminal D-alanine by D-lactate reduces the affinity of the antibiotic for its target. Lactobacillus plantarum is a lactic acid bacterium naturally resistant to vancomycin. It converts most of the glycolytic pyruvate to L- and D-lactate by using stereospecific enzymes designated L- and D-lactate dehydrogenases, respectively. In the present study, we show that L. plantarum actually synthesizes D-lactate-ending peptidoglycan precursors. We also report the construction of a strain which is deficient for both D- and L-lactate dehydrogenase activities and which produces only trace amounts of D- and L-lactate. As a consequence, the peptidoglycan synthesis pathway is drastically affected. The wild-type precursor is still present, but a new type of D-alanine-ending precursor is also synthesized in large quantities, which results in a highly enhanced sensitivity to vancomycin.

Use of homologous expression-secretion signals and vector-free stable chromosomal integration in engineering of Lactobacillus plantarum for alpha-amylase and levanase expression

The genuine alpha-amylase gene from Bacillus licheniformis (amyL) is not expressed in Lactobacillus plantarum, but replacement of the amyL promoter by a strong L. plantarum promoter leads to efficient expression of the gene and secretion of more than 90% of the alpha-amylase into the culture supernatant. A series of L. plantarum genetic cassettes (transcription and translation with or without secretion) were cloned by translation fusion of random DNA fragments to the silent amyL coding frame in the pGIP212 probe vector (P. Hols, A. Baulard, D. Garmyn, B. Delplace, S. Hogan, and J. Delcour, Gene 118:21-30, 1992). Five different cassettes were sequenced and found to harbor genetic signals similar to those of other gram-positive bacteria. The functions of the cloned cassettes and the cassettes isolated previously from Enterococcus faecalis were compared in E. faecalis and L. plantarum, respectively. All signals were well recognized in L. plantarum, but cassettes isolated from L. plantarum led to a low level of amylase production in E. faecalis, suggesting that the L. plantarum signals are more species specific. Six transcriptional or translational fusions were constructed to express the Bacillus subtilis levanase gene (sacC) in L. plantarum. All of these constructions were capable of inducing levanase production and secretion in the culture supernatant, and, furthermore, L. plantarum strains harboring the most efficient fusions could grow in MRS medium containing inulin as the major carbon source. Finally, a two-step chromosomal integration procedure was used to achieve efficient stabilization of an amylase construction without any residual resistance marker or vector sequence.

Laboratory intercomparison of gene expression assays

The possibility of a large-scale acute radiation exposure necessitates the development of new methods that could provide rapid individual dose estimates with high sample throughput. The focus of the study was an intercomparison of laboratories' dose-assessment performances using gene expression assays. Lithium-heparinized whole blood from one healthy donor was irradiated (240 kVp, 1 Gy/min) immediately after venipuncture at approximately 37°C using single X-ray doses. Blood samples to establish calibration curves (0.25-4 Gy) as well as 10 blinded test samples (0.1-6.4 Gy) were incubated for 24 h at 37°C supplemented with an equal volume of medium and 10% fetal calf serum. For quantitative reverse transcription polymerase chain reaction (qRT-PCR), samples were lysed, stored at -20°C and shipped on ice. For the Chemical Ligation Dependent Probe Amplification methodology (CLPA), aliquots were incubated in 2 ml CLPA reaction buffer (DxTerity), mixed and shipped at room temperature. Assays were run in each laboratory according to locally established protocols. The mean absolute difference (MAD) of estimated doses relative to the true doses (in Gy) was calculated. We also merged doses into binary categories reflecting aspects of clinical/diagnostic relevance and examined accuracy, sensitivity and specificity. The earliest reported time on dose estimates was <8 h. The standard deviation of technical replicate measurements in 75% of all measurements was below 11%. MAD values of 0.3-0.5 Gy and 0.8-1.3 Gy divided the laboratories contributions into two groups. These fourfold differences in accuracy could be primarily explained by unexpected variances of the housekeeping gene (P = 0.0008) and performance differences in processing of calibration and blinded test samples by half of the contributing laboratories. Reported gene expression dose estimates aggregated into binary categories in general showed an accuracies and sensitivities of 93-100% and 76-100% for the groups, with low MAD and high MAD, respectively. In conclusion, gene expression-based dose estimates were reported quickly, and for laboratories with MAD between 0.3-0.5 Gy binary dose categories of clinical significance could be discriminated with an accuracy and sensitivity comparable to established cytogenetic assays.

Cloning of the D-lactate dehydrogenase gene from Lactobacillus delbrueckii subsp. bulgaricus by complementation in Escherichia coli

A strain of Escherichia coli (FMJ144) deficient for pyruvate formate lyase and lactate dehydrogenase (LDH) was complemented with a genomic DNA library from Lactobacillus delbrueckii subsp. bulgaricus. One positive cloned showed LDH activity and production of D(-)lactate was demonstrated. The nucleotide sequence of the D-LDH gene (ldhA) revealed the spontaneous insertion of an E. coli insertion sequence IS2 upstream of the gene coding region. The open reading frame encoded a 333-amino acid protein, showing no similarity with known L-LDH sequences but closely related to L. casei D-hydroxyisocaproate dehydrogenase (D-HicDH).

Genome scans reveal candidate regions involved in the adaptation to host plant in the pea aphid complex

A major goal in evolutionary biology is to uncover the genetic basis of adaptation. Divergent selection exerted on ecological traits may result in adaptive population differentiation and reproductive isolation and affect differentially the level of genetic divergence along the genome. Genome-wide scan of large sets of individuals from multiple populations is a powerful approach to identify loci or genomic regions under ecologically divergent selection. Here, we focused on the pea aphid, a species complex of divergent host races, to explore the organization of the genomic divergence associated with host plant adaptation and ecological speciation. We analysed 390 microsatellite markers located at variable distances from predicted genes in replicate samples of sympatric populations of the pea aphid collected on alfalfa, red clover and pea, which correspond to three common host-adapted races reported in this species complex. Using a method that accounts for the hierarchical structure of our data set, we found a set of 11 outlier loci that show higher genetic differentiation between host races than expected under the null hypothesis of neutral evolution. Two of the outliers are close to olfactory receptor genes and three other nearby genes encoding salivary proteins. The remaining outliers are located in regions with genes of unknown functions, or which functions are unlikely to be involved in interactions with the host plant. This study reveals genetic signatures of divergent selection across the genome and provides an inventory of candidate genes responsible for plant specialization in the pea aphid, thereby setting the stage for future functional studies.

NAD(+)-dependent D-2-hydroxyisocaproate dehydrogenase of Lactobacillus delbrueckii subsp. bulgaricus. Gene cloning and enzyme characterization

A genomic library from Lactobacillus delbrueckii subsp. bulgaricus was used to complement an Escherichia coli mutant strain deficient for both lactate dehydrogenase and pyruvate formate lyase, and thus unable to grow anaerobically. One recombinant clone was found to display a broad specificity NAD(+)-dependent D-2-hydroxyacid dehydrogenase activity. The corresponding gene (named hdhD) was subcloned and sequenced. The deduced amino acid sequence of the encoded enzyme indicates a 333-residue protein closely related to D-2-hydroxyisocaproate (i.e. 2-hydroxy-4-methyl-pentanoate) dehydrogenase (D-HO-HxoDH) of Lactobacillus casei and other NAD(+)-dependent D-lactate dehydrogenases (D-LDH) from several other bacterial species. The hdhD gene was overexpressed under the control of the lambda phage PL promoter and the enzyme was purified with a two-step method. The L. delbrueckii subsp. bulgaricus enzyme, like that of L. casei, was shown to be active on a wide variety of 2-oxoacid substrates except those having a branched beta-carbon.

Role of autoantibodies in the pathogenesis and association of endocrine autoimmune disorders

This review has focused on the nature and significance of aAB detected in the serum of patients with EAD. Although many antibodies are characteristically detected in the serum of patients with such disorders, only a few are of known pathogenic significance. Antibodies that react with soluble cytoplasmic antigens are not expected to be harmful. On the other hand, membrane or cell surface-directed antibodies are likely to be damaging, either by lysis of the cell membrane, or by reaction with hormone or other surface receptors. Clinically, measurement of aAB has important diagnostic and management value. Moreover, detection of certain antibodies before the onset of disease raises hope that the corresponding disorders may be preventable, e.g. by specific immunosuppression of those subjects, or patients, with positive tests. The possible role of aAB in the association of organ-specific AID by cross-reacting with shared epitopes in various tissues has been highlighted by the recent finding, from the authors' laboratory, of antibodies reactive with a 64-kDa membrane protein found in several tissues, including thyroid, eye muscle, and pancreas, which are frequent sites for autoimmune inflammation. Study of such antibodies and the molecular characterization of the corresponding antigens in the various involved tissues should provide information concerning the role of cross-reactivity in autoimmunity as well as leading to the development of specific immunotherapeutic agents.

Kinetics of appearance of neutralizing antibodies in 12 patients with primary or recent HIV-1 infection and relationship with plasma and cellular viral loads

HIV-1 primary infection is characterized by a short high titer viremia, which rapidly declines as the immune response emerges. The role of autologous neutralizing antibodies in the decline of viral replication was evaluated in 12 patients with primary or recent HIV-1 infection. Neutralizing antibodies detected for each patient could not generally be observed before several months after isolation of the first obtained HIV isolate. The plasma viral load, as measured by quantitation of the HIV-1 RNA, underwent a global decrease during the first 6 months of the infection, but this decrease did not seem to be associated with the emergence of neutralizing antibodies. The proviral load in peripheral blood mononuclear cells, which was studied by quantitative DNA polymerase chain reaction, exhibited fluctuations and was not as well curtailed as the plasma viremia in the majority of patients.

Risk factors for lactic acidosis in HIV-infected patients treated with nucleoside reverse-transcriptase inhibitors: a case-control study

A case-control study was undertaken to determine risk factors for lactic acidosis in human immunodeficiency virus-infected patients treated with nucleoside reverse-transcriptase inhibitors (NRTIs). From May 1996 to June 2000, 9 patients with lactic acidosis (defined as a plasma lactic acid level of >5 mM and plasma pH of <7.38) were identified. Control patients were randomly selected from among a large cohort of patients who initiated a dual NRTI regimen in 1996 or after. Two factors were associated with an increased risk of lactic acidosis: first, a creatinine clearance of <70 mL/min before lactic acidosis (OR, 15.8 [range, 3.0-86.5], P<10(-4)), and, second, a low nadir CD4+ T lymphocyte count before the inception of NRTI therapy (OR, 8.4 [range, 1.2-infinity], P=.03). The total cumulative exposure to NRTIs was not associated with an increased risk of lactic acidosis, nor was the cumulative exposure to any of the 4 NRTIs studied. According to these results, monitoring of creatinine clearance, especially in patients with a low nadir CD4+ T lymphocyte count, could lead to modifications in antiretroviral therapy in order to diminish the risk of occurrence of lactic acidosis.

Pathogenesis of thyroid-associated ophthalmopathy: an autoimmune disorder of the eye muscle associated with Graves' hyperthyroidism and Hashimoto's thyroiditis

Thyroid-associated ophthalmopathy, the progressive eye disorder which occurs frequently in patients with Graves' hyperthyroidism and, occasionally, in those with Hashimoto's thyroiditis, may be a two-stage disorder of the eye muscle. In the first stage, which may occur in the great majority of patients with Graves' hyperthyroidism and in an unknown, but probably small, proportion of those with Hashimoto's thyroiditis, antibodies and CD4+ (helper) T lymphocytes reactive with eye muscle and thyroid shared antigens, of which 64-kDa membrane proteins are good candidates, may initiate a mild eye muscle inflammation, manifested as eye muscle swelling on orbital imaging. The second stage, which occurs in about 25% of patients with Graves' hyperthyroidism and in 2% of those with Hashimoto's thyroiditis, may be due to reactivity of cytotoxic antibodies against eye muscle-specific membrane antigens, one of which at approximately 35 kDa appears a likely candidate, and, possibly, cytotoxic T cells in the context of the appropriate class I MHC molecule. Orbital connective tissue inflammation, which plays an important role in the development of progressive orbital inflammation, is likely to be secondary to the eye muscle reaction. The recent cloning of a 64-kDa thyroid and eye muscle antigen which shares significant homology with the muscle protein tropomodulin and mapping of its antibody-reactive epitopes provide structural information about one candidate eye muscle autoantigen and promise for a more rational approach to the diagnosis and management of this common, progressive eye disorder.

Long term production of acute-phase proteins by adult rat hepatocytes co-cultured with another liver cell type in serum-free medium

Three acute-phase proteins, haptoglobin, alpha 2-macroglobulin and hemopexin, as well as albumin, have been measured daily in the hydrocortisone-supplemented serum-free medium of pure and mixed cultures of adult rat hepatocytes for 5 and 20 days respectively. Whereas plasma protein production rapidly declined in pure culture, it remained relatively stable when hepatocytes were co-cultured with rat liver epithelial cells. In the latter cultures, an early stimulation of albumin and alpha 2-macroglobulin secretion was observed. In addition, four other plasma proteins, fibrinogen, alpha 1-acute-phase protein, alpha 1-acid glycoprotein and alpha 1-antitrypsin were shown by immunodiffusion to still be produced by day 20 of co-culture. These results suggest that hepatocyte co-cultures represent a suitable model for studying the mechanism which controls synthesis of plasma proteins, including acute-phase proteins by liver cells.

A cohort study of nevirapine tolerance in clinical practice: French Aquitaine Cohort, 1997-1999

We performed a retrospective study to evaluate, under routine circumstances, the tolerance and immunovirological changes associated with antiretroviral regimens that contain nevirapine in 137 patients (88% were antiretroviral experienced). During a mean follow-up of 11 months, 33% of patients reported side effects attributed to nevirapine, and 21% discontinued treatment because of poor tolerance. Administration of antihistamines or corticosteroids at the initiation of treatment was not protective against adverse events (relative risk, 0.82; 95% confidence interval, 0.49-1.38). The proportion of patients with hepatitis C virus (HCV) and/or hepatitis B virus (HBV) coinfection who had alanine aminotransferase levels of >100 IU/L increased from 19.4% at baseline to 42.9% at month 12 of follow-up (P=.02). We noticed a significant increase of the proportion of patients with total cholesterol levels of >5.5 mM (P=.02). We have shown that there is a high level of discontinuation of nevirapine therapy in clinical practice and that side effects were not prevented by administration of antihistamines or corticosteroids. Coinfection with HCV or HBV increased the risk of hepatotoxicity, which lead to the cautious use of nevirapine for such patients.

Prevalence of antibodies reactive with a 64 kDa eye muscle membrane antigen in thyroid-associated ophthalmopathy

We have determined the prevalences of antibodies reactive with certain pig eye muscle membrane antigens, as determined from SDS-polyacrylamide gel electrophoresis (PAGE) and western blotting, in patients with autoimmune thyroid disorders with or without associated ophthalmopathy. The most frequently detected antibody was that directed against a protein of 64 kDa. Antibodies against this antigen were detected in 33% of unselected patients with ophthalmopathy and in 75% of those with severe, active, orbital inflammation of less than 12 months duration. Such antibodies were detected also in 33% of patients with Graves' hyperthyroidism with no apparent eye disease and in 17% of patients with Hashimoto's thyroiditis with no eye disease but were not detected in patients with nonautoimmune thyroid disorders in 25 normal subjects tested. In the majority of sera showing reactivity with this protein, reactivity with membrane antigens of 55 and 95 kDa also were observed, suggesting that the three proteins were conformationally associated. Cytotoxic antibodies against human eye muscle cells, measured in antibody-dependent cell-mediated cytotoxicity (ADCC), were demonstrated in 37% of patients with ophthalmopathy. There was no significant correlation, in patients with eye disease, between positive ADCC tests and antibodies to the 64 kDa protein, the 64 kDa reactive antibody being found in 50% of patients with positive ADCC and in 35% of those with negative tests. In this study, a clear association has been shown between thyroid-associated ophthalmopathy and the detection, in immunoblotting, of antibodies reactive with a 64 kDa eye muscle membrane antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

D175 discriminates between NADH and NADPH in the coenzyme binding site of Lactobacillus delbrueckii subsp. bulgaricus D-lactate dehydrogenase

The NAD-dependent D-(-)-lactate dehydrogenase (D-LDH) from Lactobacillus delbrueckii subsp. bulgaricus (in short, L. bulgaricus) has been modified at position 175 by site-directed mutagenesis, changing a conserved aspartate residue into an alanine. The D175A mutant enzyme displays a 40-fold shift in coenzyme preference from NADH to NADPH. This demonstrates that D175 truly belongs to the amino acid consensus GXGXXGX(17)D (where X represents any residue) which is the signature of the coenzyme binding site of most NAD-dependent dehydrogenases.

Determination of nalidixic acid and its two major metabolites in human plasma and urine by reversed-phase high-performance liquid chromatography

This paper describes a precise and sensitive method for analysis of nalidixic acid and its two major metabolites in plasma and urine following the oral administration of a therapeutic dose in humans. After addition of an internal standard (oxolinic acid), 1-ml samples of plasma or urine are extracted at acidic pH with chloroform. The extracts are purified by re-extraction with sodium hydroxide solution and then chloroform. The final extracts are evaporated to dryness, reconstituted in mobile phase and injected into a high-performance liquid chromatograph equipped with RP-8 column and UV detector operating at 254 nm. The limit of sensitivity of the method is lower than 0.5 micrograms/ml of plasma or urine for each compound. The applicability of the method to pharmacokinetic studies of nalidixic acid in humans is demonstrated.

Hepatitis C virus infection and lymphoproliferative diseases in France: a national study. The GERMIVIC Group

The putative role of hepatitis C virus (HCV) infection in the pathophysiology of lymphoproliferative diseases (LPD) is supported by North American and southern European studies reporting high HCV seroprevalence in patients with B-cell-non-Hodgkin lymphoma (NHL). In order to evaluate the situation in France, we conducted a retrospective national study about the association of chronic HCV infection and LPD. 72 Internal Medicine and Infectious Diseases departments were contacted. Response rate was 51.4%. We recorded 43 LPD (19 males, 24 females): 31 B-cell-NHL, 4 Waldenström's macroglobulinemia, 3 chronic lymphocytic leukemia, 2 multiple myeloma, 2 lymphomas of the mucosa-associated lymphoid tissue, and 1 Hodgkin's disease. Mean age at HCV diagnosis was 62 years (range 33-84). In 16 cases, LPD occurred in patients known to be HCV-infected. For 11 patients, LPD diagnosis preceded the diagnosis of HCV infection, whereas diagnosis was done simultaneously in 11 patients. For those with accurate infection date, mean interval between both events was 15.2 years. Fourteen patients had HCV extrahepatic manifestations: 9 mixed cryoglobulinemia, including 7 with NHL, 5 sicca syndrome (5 NHL), and both in one patient. Cohort of HCV-infected patients could be accurately determined for 16 departments, totaling 1,485 patients and 37 cases. Thus, from our data the frequency of LPD among HCV-infected patients approximates 2. 49%. Despite possible bias inherent to this retrospective study, our data support the hypothesis of HCV-associated LPD and particularly B-cell-NHL. In France, this association is much lower than in Italy. Further studies are needed to assess the precise role of HCV in the multistep process leading to monoclonal proliferation.

Myasthenia gravis exacerbation or unmasking associated with telithromycin treatment

Telithromycin, a new ketolide antibiotic, has been implicated in the exacerbation or unmasking of myasthenia gravis. This retrospective study presents two clinical reports and summarizes eight other suspected cases notified to the French pharmacovigilance system, highlighting a potentially life-threatening risk of telithromycin treatment in myasthenic patients. An important common feature was that, in seven cases, symptomatology occurred within 2 hours of first telithromycin intake--notably in cases of severe exacerbation.

Reproducibility of the cardiovascular reactivity to a computerized version of the Stroop stress test in normotensive and hypertensive subjects

The 1-month reproducibility of haemodynamic and sympathoadrenal responses to a standardized mental stress test was studied in ten normotensive and ten hypertensive individuals. The stress test was a computerized adaptation of the Stroop test and sympathetic activity was evaluated by measuring urinary catecholamine excretion. Three-way analysis of variance (stress, session, blood pressure) revealed significant increases in systolic and diastolic blood pressures and in heart rate during the stress test. Test-retest correlation coefficients for basal stress levels, and stress-induced variations were significant (r from 0.59 to 0.88). The stress test induced a significant increase in urinary noradrenaline excretion with large intra- and interindividual variability. The significant test-retest correlations and the lack of period effect for haemodynamic parameters indicated good temporal stability. However, a slight decrease in stress-induced reactivity was observed. This standardized mental stress test may be useful in epidemiological and therapeutic trials to measure blood pressure and heart rate responses, but measurement of urinary catecholamine excretion does not provide any additional information.

Mechanical properties of pathological equine superficial digital flexor tendons

The objective of this study was to mechanically characterise superficial digital flexor tendon (SDFT) lesions. Eight pathological SDFTs, isolated from 6 adult horses, were tested in traction until rupture (at 1 mm/s). The stresses and strains simultaneously undergone by each of the 7 segments of a tendon were determined throughout the test, and the modulus of elasticity of each segment was evaluated from the segmental stress-strain curve thus obtained. These mechanical data were compared to those obtained on 10 normal SDFTs. After the test, the tendinous segments were submitted to a histological examination in order to characterise the tissues. Three lesional categories (I to III, of increasing maturity), as well as the normal tendinous tissue, were defined and assessed quantitatively according to their extent in the histological sections. The most recent and severe lesions (categories I and II) were correlated with a large degree of hypertrophy (often above 200%) of the corresponding segments, with a resulting decrease in the stress at tendon rupture, and a slight decrease in the strain at tendon rupture in spite of a low modulus of elasticity (low stiffness). In contrast, the adjacent areas, less or not injured, underwent compensatory strains. This relative overstraining was especially critical with category III tissue, often present in the transitional areas between sound and severely injured segments. Here the modulus of elasticity was low whereas the hypertrophy was only slight. Therefore, the corresponding segments seemed to be the most fragile sites, and those most predisposed to recurring injury, in an injured SDFT.