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Biomedical subjects

C Lambert

Publications and source records attributed to C Lambert.

At least 217 records · Page 12Linked to original sources
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[Hereditary C5 deficiency and recurrent Neisseria meningitidis meningitis].

Deficiencies of the terminal C fragments of the complement system are known to be associated with a remarkable increase in the frequency of Neisseria infections. The correlation is even closer between deficiency of C5 and recurrent N. meningitidis meningitis. The reasons for this bacterial specificity and the immunopathological mechanisms involved have not been clearly established. However, it is known that only adult subjects with homozygous deficiency are affected and that the deficiency is transmitted as an autosomal recessive trait unrelated to the HLA system.

Adult↗
PubMedDate not supplied

Expression of PGP9.5 on Langerhans' cells and their precursors.

Langerhans' cells are epidermal dendritic cells, derived from blood precursors. Their main function is antigen presentation to T-cells. They are able to express neuronal proteins, such as neuron-specific enolase or substance P-receptor. They are closely associated with nerve fibres. PGP9.5 is the most specific neuronal protein in the epidermis. Epidermal Langerhans' cells can express PGP9.5 if denervated. Using flow cytometry, we found that cultured CD34+ precursors did not express PGP9.5, whereas suspensions of fresh or cultured Langerhans' cells could express this neuronal protein. Precursors of Langerhans' cells are not able to express PGP9.5, suggesting that they are not mature enough or that the capacity to express PGP9.5 may be acquired only in the epidermis. The function of PGP9.5 on Langerhans' cells and mature dendritic cells remains unknown. PGP9.5 might be related to dendritic cell maturation or to the lack of contacts with nerve endings.

Antigens, Differentiation↗
PubMedDate not supplied

Food-contact epoxy resin: co-variation between migration and degree of cross-linking.

In order to predict the behaviour towards foodstuffs of an epoxy resin composed of bisphenol A diglycidyl ether (BADGE), 4,4'-methylenedianiline (MDA) and additives (plasticizers: dibutylphthalate (DBP), dioctylphthalate (DOP); accelerator: salicylic acid; inorganic fillers), a co-variation was established between the parameters evaluating the degree of cross-linking of the three-dimensional network and the migration of constituent molecules into various food simulants (distilled water, distilled water/ethanol/acetic acid, distilled water/ethanol). Varied degrees of cross-linking were obtained by subjecting the resin to different curing temperatures: respectively, 5 degrees C, 20 degrees C, 50 degrees C and 90 degrees C for 7 days. Irrespective of the food stimulant tested, specific migrations (DBP, DOP, salicylic acid, primary aromatic amines) diminished greatly as the curing temperature increased. At the same time, the degree of cross-linking increased with curing temperature, as indicated by the increase in glass transition temperature, the decrease in residual reaction exotherms and increased stability of the rubber storage modulus E'rub (increase in cross-link nodes), the fall in relaxation enthalpies (reduction in physical ageing) and the decreased amplitude of the loss-factor, tan delta (reduction in chain mobility). Maximum cross-linking was obtained in the resin cured at 90 degrees C (temperature above Tg infinity). In contrast to the degree of cross-linking, evaporation contributed little to the reduction of migration due to the elevation of curing temperature.

Chemical Phenomena↗
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Relationship between an arrhythmogenic action of lidocaine and its effects on excitation patterns in acutely ischemic porcine myocardium.

To investigate the relationship between the effects of lidocaine on excitation patterns and its effects on the incidence of arrhythmias, the left anterior descending coronary artery was occluded for 6-min periods separated by 30 min of reperfusion, under control conditions and after injection of lidocaine, at a dose of either 2.5, 5.0, or 10.0 mg/kg i.v., in 29 open-chest anesthetized pigs. Sixty-three unipolar electrograms and a surface lead electrocardiogram were continuously recorded during atrial pacing and spontaneous ventricular arrhythmias. Ventricular fibrillation (VF) occurred only in four of a total of 45 control occlusions. VF occurred in two of five pigs following injection of lidocaine 2.5 mg/kg, in 15 or 17 pigs following injection of a 5 mg/kg dose, and in all three preparations following injection of a 10 mg/kg dose. Just prior to VF during occlusions preceded by injections of lidocaine 5 mg/kg, activation time of ischemic myocardium in atrial-paced beats was delayed by only 30 +/- 17 ms beyond preocclusion values, compared with 18 +/- 11 ms at a similar time during control occlusions and 33 +/- 18 ms at the end of control occlusions (mean +/- SD; n = 8). As ventricular tachycardia (VT) developed in the presence of lidocaine, conduction was further slowed or blocked in ischemic areas, and slowed in nonischemic regions; at the transition from VT to VF, excitation patterns displayed circus movement involving nonischemic regions.

Animals↗
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Pulmonary malakoplakia diagnosed by fine needle aspiration. A case report.

BACKGROUND: Pulmonary malakoplakia is an uncommon disorder, with 24 previously reported cases, only 4 of which were diagnosed by bronchial washings, bronchial brushings or aspiration cytology. We report a case that was diagnosed initially by computed tomography (CT)-guided fine needle aspiration (FNA) cytology. CASE: A 56-year-old male with follicular small cleaved cell lymphoma had a 10-cm left lower lobe mass compressing the main bronchus to that lobe. A transthoracic, CT-guided FNA specimen consisted predominantly of foamy macrophages, many of which contained typical Michaelis-Gutmann bodies. Microbiologic cultures identified Rhodococcus equi. A subsequent transbronchial biopsy and left pneumonectomy specimen confirmed the cytologic diagnosis. CONCLUSION: Pulmonary malakoplakia associated with R equi pneumonia is a rare lesion that is essentially limited to immunocompromised hosts. Awareness of the FNA cytomorphology of this lesion permits resolution of the typical clinical differential diagnosis of pulmonary masses in the immunocompromised host and can facilitate treatment.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Three-year effectiveness of highly active antiretroviral treatment in the Luxembourg HIV cohort.

UNLABELLED: Clinical trials have shown that highly active antiretroviral treatment (HAART) is able to reduce HIV plasma viral loads to undetectable in 70% to 90% of patients and to increase CD4 cell counts. HAART in community settings (i.e., nonclinical trial situations) is reported to be much less effective. STUDY DESIGN: Observational study. PURPOSE: The aim of our study was to evaluate the effectiveness of protease inhibitor (PI)-based HAART in the Luxembourg HIV cohort after 36 months of treatment in previously treated and untreated patients. The secondary aim was to identify surrogate markers associated with long-term virologic and immunologic outcomes. PATIENTS AND METHOD: Seventy-three PI-naive patients, who started on HAART, combining one PI and two nucleoside reverse transcriptase inhibitors (NRTIs),with a follow-up of 3 years, were evaluated with plasma viral load and CD4 cell counts every 3 months and were analyzed retrospectively. Patients who had been treated previously with NRTI (n = 48) were at a more advanced stage of disease. RESULTS: Overall, there was a mean decrease in viral load compared to baseline of -1.89 log RNA copies/mL (SD = 1.40) that persisted at month 36. Sixty-two percent (62%) of patients reached an undetectable viral load (i.e., below 500 copies/mL): 82% and 53% of NRTI-naive and NRTI-experienced patients, respectively (p =.013). CD4 cell counts increased progressively in both groups with a sustained effect (mean increase of 146 cells/mL +/- 241) at month 36. NRTI-naive patients had a mean increase of 257 cells/mL (SD = 305), in contrast to experienced patients who had an increase of 108 cells/mL (SD = 206) at 3 years. Proportions of patients with a CD4 count under 200 cells/mL fell after 3 years for NRTI-naive (from 66% to 43%) and for experienced patients (from 32% to 13%). Predictors of short duration of viral load response were in decreasing order of importance: clinical AIDS, the use of saquinavir hard gel formulation as initial PI, and the number of NRTIs previously used. Viral load response was the only significant predictor of CD4 changes. CONCLUSION: In a community setting, effectiveness of PI-based HAART at 3 years is still achieved for most patients. NRTI-experienced patients have a good long-term response rate even if it is lower than NRTI-naive patients. A poor treatment response is associated with a more advanced stage of disease before HAART is introduced.

Adult↗
PubMedDate not supplied

Fast genotypic detection of drug resistance mutations in the HIV-1 reverse transcriptase gene of treatment-naive patients.

OBJECTIVES: This study was performed to assess the frequency of drug resistance mutations in treatment-naive HIV-1-infected patients. STUDY DESIGN/METHODS: Frozen plasma samples from 135 treatment-naive HIV-infected adults were available from the first time the patients were seen for their infection in our center between 1992 and 1997. A rapid genotypic assay based on reverse DNA hybridization (LiPA HIV-1 RT, Murex, London, U.K.) was used to study substitutions at reverse transcriptase (RT) codons 41, 69, 70, 74, 184, and 215. Additionally, a selective polymerase chain reaction (PCR) for the multiple dideoxynucleoside resistance (MddNR) mutation Q151M was performed. RESULTS: 16 patients (12%) harbored virus with one or more drug resistance mutations. The prevalence of patients with drug-resistant virus was 0% in 1992, 17% in 1993, 0% in 1994 (only 6 samples tested), 18% in 1995, 14% in 1996, and 9% in 1997. Mutation K70R (resistance to zidovudine) was found in 8 patients, M41L (resistance to zidovudine) in 5 patients, M184V/I (resistance to ddI/ddC/3TC) in 2 patients, and T215Y/F (resistance to zidovudine) in 4 patients. All samples were wild type at codons 69 (ddC), 74 (ddI), and 151 (MddNR). CONCLUSIONS: Virus strains containing drug resistance mutations are now found in about 1 of 10 treatment-naive HIV-1-seropositive patients in Luxembourg. We believe that testing for drug-resistant virus before starting treatment should be recommended and will help to improve the selection of the most effective antiretroviral treatment. We also suggest the need for an international surveillance program on HIV drug resistance in treatment-naive patients.

Adult↗
PubMedDate not supplied

In the red.

Explore the source record for details and available documents.

England↗
PubMedDate not supplied

Flow cytometric analysis of antigen expression in malignant and normal renal cells.

UNLABELLED: Flow cytometry allows quantitative analysis of cancer cells. The aim of this study was to make a quantitative study of antigen expression in malignant and normal renal cells in order to find the efficient monoclonal antibodies (mAbs) for labelling renal cancer cells. MATERIAL AND METHODS: 15 malignant and adjacent normal renal tissues and three renal carcinoma cell lines (ACHN, A704 and CAKI-2) were analyzed. The malignant and normal renal tissues were dissociated mechanically into cell suspension. The mAbs and isotype controls were used for immunochemical labelling. The stained cells were analyzed by flow cytometry. RESULTS: Renal tumor associated antigen G 250 was frequently detected in malignant renal cells but not in normal renal cells. Renal tumor associated antigen gp200 recognized by 66.4.C2 and PN-15 was frequently detected in malignant cells, normal renal cells and also in all three carcinoma cell lines. Epithelial antigens were strongly positive in normal renal cells. Compared with MOC 31, Ber-EP4 and E 29, W-lD9 was mostly reactive to malignant renal cells. VU-1D9 was strongly positive on ACHN and A704. The carbohydrate carcinoma antigens CA 125, DF3 and Sialyl Lewis(a) were detectable in some of the malignant and normal renal cells. Sialyl Lewis(a) could be weakly detected on ACHN and A 704. Pan-cytokeratins and cytokeratin (CK) 8 were strongly expressed in malignant and normal renal cells and in all three cell lines. CONCLUSION: Our results indicated that G 250, 66.4.Ca, PN-15, VU-1D9, MNF116 and anti-ckg were efficient mAbs for labelling renal cancer cells. Their potential clinical application by flow cytometry should be explored.

Adult↗
PubMedDate not supplied

Residual renal function in a large cohort of peritoneal dialysis patients: change over time, impact on mortality and nutrition.

OBJECTIVE: Residual renal function contributes importantly to total solute clearance in peritoneal dialysis (PD) patients. This study was designed to examine the progression of residual renal function over time and its impact on nutrition and mortality in PD patients in the six New England states (ME, NH, VT, CT, MA, RI) comprising End Stage Renal Disease (ESRD) Network 1. DESIGN: As part of the ESRD Clinical Indicators Project, data on 990 PD patients in Network 1 were abstracted from data supplied by dialysis units in the fourth quarter of 1997. This included demographic information; dose of PD in L/day; weekly renal, dialysis, and total Kt/V urea; weekly renal, dialysis, and total creatinine clearance (CCr); serum albumin level; and mortality and transplantation information. Data collection was repeated in the second and fourth quarters of 1998 and in the second quarter of 1999. PATIENTS: 990 PD patients in Network 1. OUTCOME MEASURES: The change in total and renal solute clearances over time, the relationship between renal clearance and mortality, and the relationship between renal clearance and nutritional status, as represented by serum albumin. RESULTS: Over the 2-year period, mean weekly renal Kt/V urea and weekly renal CCr dropped significantly. To examine the effect of residual renal function on mortality, patients were divided into high and low (above and below the median) weekly renal Kt/V urea and weekly renal CCr groups. Patients above the median levels of both weekly renal Kt/V urea and weekly renal CCr had a significantly decreased risk of dying during the observation period, after controlling for age, gender, serum albumin level, and diabetic status [OR for high vs low renal Kt/V urea 0.54 (CI 0.34 - 0.84), OR for high vs low renal CCr 0.61 (CI 0.40 - 0.94)]. The mean weekly renal Kt/V urea was significantly and directly correlated with the mean serum albumin level by Spearman rank correlation (R = 0.133, p < 0.001), as was the mean weekly renal CCr (R = 0.115, p < 0.001). CONCLUSIONS: Residual renal function is an important contributor to total solute clearance in PD patients. Even at low levels it is linked to decreased mortality and better nutritional status.

Adolescent↗