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Biomedical subjects

C Richard

Publications and source records attributed to C Richard.

At least 145 records · Page 8Linked to original sources
PubMed1995

Global energetic failure in brain-dead patients.

The objective of this prospective, clinical study of consecutive patients was to test the hypothesis of a global energetic failure in brain-dead patients by analyzing indices of peripheral oxygenation during brain-dead resuscitation. Subjects comprised 24 subjects with brain death criteria from a multidisciplinary intensive care unit. The causes of brain death were multiple: severe traumatic head injury, cerebrovascular event, cerebral anoxia, primary brain tumor, and gunshot wound to the head. Interventions used were radial and pulmonary artery catheterization. Hemodynamic and gasometric parameters and blood lactate levels were measured immediately after the diagnosis of brain death (T0) and 4 hr later (T4), while patients were receiving a therapeutic protocol (fluids, vasopressive drugs) adjusted to reach a mean arterial pressure of 75 mmHg. In 18 of our 24 patients, a blood lactate level > or = 2 mmol/L (mean +/- SD: 4 +/- 2 mmol/L) associated with an increased mean lactate to pyruvate ratio (14.4 +/- 3.2) was observed at T0, while oxygen delivery (DO2) was high (533 +/- 208 ml/min/m2) and mean arterial pressure was 76 +/- 21 mmHg. Patients were subdivided into two groups according to changes in DO2 from T0 to T4: group D comprised 14 patients (10 with hyperlactatemia and 4 with normal lactate) in whom DO2 and oxygen consumption (VO2) simultaneously decreased from T0 to T4 without significant change in lactate level; group I comprised 10 patients (8 with hyperlactatemia and 2 with normal lactate) in whom DO2 and VO2 simultaneously increased, while the blood lactate level decreased significantly from 3.5 +/- 2.5 mmol/L at T0 to 2.1 +/- 1.0 mmol/L at T4 (P < 0.05). Our results indicate that the brain-dead state was frequently associated with a global energetic failure probably due to a cellular oxygen deficit, despite blood pressure within the normal range. This energetic failure, because it is associated with high levels of DO2, could result from a defect in peripheral oxygen extraction. Aggressive therapy, achieved by producing a further increase in DO2, may reduce this global tissue oxygen deficit.

Adolescent↗
PubMed1995

Down-regulation of c-Myc and Max genes is associated to inhibition of protein phosphatase 2A in K562 human leukemia cells.

Treatment of the human myeloid leukemia K562 cells with the protein phosphatase inhibitors okadaic acid or calyculin A resulted in down-regulation of both c-myc and max genes at the mRNA and protein levels. The extent of the down-regulation was similar for both genes and was dependent on the dose and on the treatment time. Interestingly, c-myc and max down-regulation was concomitant with apoptosis induced by okadaic acid and calyculin A in K562 cells. The expression of c-myc and max returned to control levels after the removal of okadaic acid from the media, although apoptosis was irreversible. These effects were observed at okadaic acid concentrations (15 nM) that inhibited the activity of protein phosphatase type 2A but not of phosphatase type 1. We conclude that the inhibition of protein phosphatase 2A is associated to decreased levels of c-Myc/Max heterodimers in K562 cells.

Apoptosis↗
PubMed1995

Fibroblast growth factor-2 can mediate cell attachment by linking receptors and heparan sulfate proteoglycans on neighboring cells.

The myeloid 32D cell line, which grows in suspension and does not express FGF receptors or heparan sulfate proteoglycans, was transfected with the cDNA encoding FGF receptor-1 (32D-flg cells). When co-cultured with glutaraldehyde-fixed Chinese hamster ovary (CHO) cells, the 32D-flg cells remained in suspension in the absence of FGF-2 but attached to the CHO monolayer in the presence of 10 ng/ml FGF-2. In contrast, 32D cells transfected with the vector alone did not attach to the CHO monolayer in the presence of FGF-2. FGF-2-dependent attachment of 32D-flg cells was prevented by inclusion of 10 micrograms/ml heparin in the incubation medium and was diminished when CHO mutants in glycosaminoglycan synthesis or wild-type CHO cells treated with heparinase were used, indicating that the attachment occurred through FGF-2 interactions with heparan sulfates on the CHO cells. Attachment of 32D-flg cells to wild-type CHO cells was half-maximal at 0.4 ng/ml FGF-2 and was also observed with FGF-1 but not FGF-4. 32D-flg cells also attached to living CHO cells in a FGF-2-dependent manner, but attachment was transient at 37 degrees C. Induction of new proteins was not required for FGF-2-dependent attachment, since attachment occurred when the co-cultures were incubated at 4 degrees C and when the 32D-flg cells were preincubated with cycloheximide. FGF-2-dependent attachment of 32D-flg cells was also observed with Balb/C 3T3, NIH 3T3, and bovine capillary endothelial cells. We conclude that attachment is due to FGF-2 binding simultaneously to receptors on the 32D-flg cells and heparan sulfates on the CHO monolayers; thus, the FGF-2 acts as a bridge between receptor-expressing cells and heparan sulfate-bearing cells. In addition, induction of DNA synthesis in 32D-flg cells in response to FGF-2 was potentiated by the CHO-associated heparan sulfates to the same extent as by soluble heparin, indicating that this interaction has functional significance.

3T3 Cells↗
PubMed1995

[Neoplastic ureteral obstruction: drainage by percutaneous nephrostomy or double J catheterization].

OBJECTIVES: Neoplasic obstruction of the ureter is observed in patients with pelvic or extra-pelvic cancer. Indications of upper urinary tract drainage need to be clarified. METHODS: Percutaneous nephrostomy or double J catheter drainage was performed in 104 patients with ureteral obstruction due to pelvic cancer (bladder, prostate, uterus, ovary, rectum) or extra-pelvic cancer (usually breast and digestive cancers). Percutaneous nephrostomy or double J catheter was the first drainage procedure in 85 and 76 patients respectively. RESULTS: Success rate in first intention drainage was 74.5% with the double J catheter. When this procedure was impossible, percutaneous nephrostomy was always performed. In 52 cases we attempted to convert the nephrostomy to double J catheter drainage. Success rate was 68.8%. The main complications observed were ineffective drainage (12.5%) and infection (10.5%). CONCLUSION: These patients have a mean survival of 6.8 months despite the chemotherapy which is facilitated by the improved renal function.

Adult↗
PubMed1995

[Research on prognostic factors in large-cell lymphomas].

BACKGROUND: To carry out a study on the prognostic factors in large cell lymphomas (LCL) treated during the last decade and validate the international prognostic index (IPI). METHODS: One hundred twenty-four cases of newly diagnosed LCL, treated from 1978 to 1990, with a mean follow up of 27 months (1-142) were included in the study. The chemotherapy used was: CHOP (65%), ProMACE-CytaBOM (17%) and others (C-MOPP, MACOP-B). RESULTS: Complete remission (CR) was achieved in 71% of the cases and partial in 11%. Logistic analysis allowed the identification of three adverse factors to CR: Ann Arbor stage III, IV (p = 0.004; odds ratio, OR = 0.19), elevated tumoral load (p = 0.006; OR = 0.22) and age > or = 60 years (p = 0.02; OR = 0.31). Recurrence free survival (RFS) at 3 years was 67% (CI 95%; 55-79) with the median not having been achieved. Cox analysis allowed the identification to the ECOG > or = 2 scale as the only independent adverse factor (p = 0.0006; RR = 4.85) while Ann Arbor staging demonstrated marginal influence (p = 0.08). Global survival (GS) at 5 years was 45% (CI 95%; 35-55) with a median of 38 months. Multivariant analysis of independent adverse factors of GS were ECOG scale > or = 2 (p < 0.00001; RR = 6.07), Ann Arbor stage (p = 0.004; RR = 2.64) and hypoalbuminemia (p = 0.01; RR = 2.28). On inclusion of therapeutic response (TR) in the analysis, the factors chosen were absence of CR (p < 0.00001; RR = 9.58) and ECOG > or = 2 (p = 0.0004; RR = 4.24). CONCLUSIONS: Three variables evaluated at diagnosis, general state (ECOG), Ann Arbor stage and albumin, determined the prognosis in this series of large cell lymphoma. A prognostic model was designed from the same with three risk groups. The application of the international prognostic index to this series separated the patients into 4 groups of differentiated prognosis.

Adolescent↗
PubMed1995

Processing and hydrolytic mechanism of the cgkA-encoded kappa-carrageenase of Alteromonas carrageenovora.

The cgkA gene of Alteromonas carrageenovora encodes a kappa-carrageenase with a predicted mass of 44212 Da, much larger than the 35 kDa estimated from SDS/PAGE of the protein purified from culture supernatants. Immunoblotting experiments showed the presence of a protein of 44 +/- 2 kDa in both native and recombinant bacterial intracellular extracts, suggesting that the kappa-carrageenase is produced as a preproprotein which undergoes proteolytic processing twice during secretion. To determine the exact site of C-terminal cleavage, the precise mass of the purified extracellular kappa-carrageenase was measured by electrospray-ionization/mass spectrometry and found to be 31,741 +/- 3 Da. The mature kappa-carrageenase of A. carrageenovora thus appears to be composed of 275 amino acids, from residue Ala26 to residue Asn301 of the cgkA gene product. To assess the molecular mechanism of this member of family 16 of glycosyl hydrolases, hydrolysis of neocarrahexaitol by the kappa-carrageenase was monitored by gel filtration chromatography and 13C-NMR. Results show that neocarrabiitol and beta-neocarratetraose are initially formed, demonstrating that the enzyme operates with a molecular mechanism retaining the anomeric configuration. Consistent with this result, the enzyme was also shown to be able to catalyze transglycosylation.

Bacterial Proteins↗
PubMed1995

CDP571, a humanized antibody to human tumor necrosis factor-alpha: safety, pharmacokinetics, immune response, and influence of the antibody on cytokine concentrations in patients with septic shock. CPD571 Sepsis Study Group.

OBJECTIVES: To determine the safety of a "humanized" antibody to human anti-tumor necrosis factor-alpha (TNF-alpha) in patients with septic shock, and to examine the pharmacokinetics, immune response, and influence of the antibody on cytokine concentrations in this patient group. DESIGN: Prospective, randomized, placebo-controlled, phase II multicenter clinical trial, with escalating doses of a fully humanized anti-TNF-alpha antibody (CDP571). SETTING: Seven academic intensive care units in Europe. PATIENTS: Forty-two patients with rapidly evolving septic shock who received CDP571 in addition to standard supportive care. INTERVENTIONS: Patients received intravenously either placebo or one of four single doses of CDP571: 0.1, 0.3, 1.0, or 3.0 mg/kg. MEASUREMENTS AND MAIN RESULTS: The humanized anti-TNF-alpha antibody was well tolerated. The overall all-cause 28-day mortality rate was 62%. Mortality rate was similar in the placebo and treatment groups, except that all six patients who received 0.3 mg/kg of CDP571 died within 7 days. This outcome, which was not dose-related, is consistent with the poorer prognostic characteristics of this group at baseline. The peak CDP571 concentrations and area under the curve increased proportionately with the dose. The low level of the immune response detected had little effect on the ability of circulating CDP571 to bind TNF-alpha and on the pharmacokinetics of the antibody. An abrupt reduction in circulating TNF-alpha concentration was observed 30 mins after CDP571 administration at all active dosage levels. While interleukin-1 beta and interleukin-6 plasma concentrations decreased with time in all dosage groups, these cytokine concentrations decreased more rapidly during the initial 24 hrs in the treatment groups than in the placebo group. CONCLUSIONS: The humanized anti-TNF-alpha antibody, CDP571, is well tolerated and able to cause a dose-dependent reduction in circulating TNF-alpha concentrations in patients with septic shock. Further studies are needed to determine the efficacy of this antibody to improve the survival rates of critically ill patients with severe sepsis.

APACHE↗
PubMed1995

Arylsulphatase from Alteromonas carrageenovora.

Arylsulphatase activity was identified in cultures of the marine bacterium Alteromonas carrageenovora, using methylumbelliferyl sulphate as substrate. In contrast with most other microbial arylsulphatases, arylsulphatase production in A. carrageenovora was not repressed by sulphate. The structural gene of arylsulphatase (atsA) was cloned and sequenced. An ORF of 984 bp was found, specifying a primary translation product of 328 amino acids with a molecular mass of 35797 Da. Arylsulphatase was partially purified from cell extracts of both A. carrageenovora and recombinant Escherichia coli. Both the recombinant and native enzymes exhibited a pI of 5.5, a Michaelis constant for methylumbelliferyl sulphate of 68 microM, and a molecular mass of approximately 35,000 Da in SDS-PAGE analysis. Secondary structure comparisons using hydrophobic cluster analysis suggest functional analogies between the arylsulphatase of A. carrageenovora, that of Mycobacterium leprae and a 33.5 kDa protein from Porphyromonas gingivalis. It is speculated that these proteins are all glycosulphohydrolases, involved with desulphatation of sulphated polysaccharides.

Amino Acid Sequence↗
PubMed1995

Excluded from universal coverage: ESRD patients not covered by Medicare.

Medicaid is believed to serve as the major insurer for end stage renal disease (ESRD) patients who are ineligible for Medicare coverage. Demographics, receipt of dialysis services, and costs of Medicaid-only populations were compared with Medicare ESRD populations in California, Georgia, and Michigan. Notable differences in patient demographics, dialysis practice patterns, and inpatient health resource utilization between the Medicaid and Medicare ESRD populations were observed. Medicaid expenditures for Medicare-ineligible ESRD patients were considerable: in 1991, California spent $46.4 million for 1,239 ESRD patients; Georgia and Michigan each spent nearly $5 million for approximately 140 ESRD patients.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1995

Detection of anti-neutrophil cytoplasmic antibodies by immunoprecipitation.

Immunoprecipitation (IP) of radiolabeled PMN extracts was used as the gold standard for anti-proteinase 3 (PR-3) autoantibody detection to validate immunofluorescence (IF) and alpha granule (alpha) ELISA. A myeloperoxidase (MPO) ELISA was also used in parallel. We studied 48 patients with strictly defined vasculitic syndromes in the initial active phase of their disease. The 3 methods confirmed the high (> 90%) sensitivity and specificity of anti-PR-3 for patients with Wegener's granulomatosis (WG). Similarly, a high (86%) sensitivity of MPO-ELISA was found in microscopic polyarteritis as defined. Using alpha-ELISA, we could not improve the detection rate of anti-PR-3 obtained by IF-cANCA-pattern reading. Moreover, a small proportion (< 15%) of biopsy-proven WG patients had anti-MPO antibodies detected by IF, usually as pANCA but also, even if rarely, as bona fide cANCA (< 5%). Thus, IF would seem to be the most reliable screening method and alpha-ELISA should be used for confirmation. On the other hand, because MPO-ELISA detected twice as many anti-MPO positive sera as did pANCA pattern reading by IF, we suggest that in the clinical context of a vasculitis, MPO-ELISA should also be used as a screening test. Although IP is not designed for routine clinical use, it should be required when reporting the presence of anti-PR-3 in vasculitis-like diseases that are fertile grounds for false positive reactions.

Adult↗
PubMed1995

[Comparative prospective study of effects of Biovisc and Healonid on endothelial cell loss and intraocular pressure in cataract surgery].

PURPOSE: The goal of this trial was to evaluate the efficacy (protective action on corneal endothelium and ability to facilitate the procedure) as well as safety (effect on intraocular pressure and inflammation) of Biovisc (new viscoelastic agent made of 1% sodium hyaluronate produced by bacterial fermentation) versus Healonid) postcataract surgery (manual or phacoemulsification). METHODS: 106 patients, 45 males and 61 females (31-94 years) were included in this prospective randomized multicentre trial and followed up for three months. Specular microscopy and intraocular pressure (IOP) measurement were the main evaluation criteria. RESULTS: At D 90, no significant difference was observed between the two viscoelastic agents on the mean endothelial cell loss (group Viovis: -8.6%; group Healonid: -6%) as well as on IOP (early peaks were transitory and resolutive). CONCLUSION: Biovisc and Healonid were similar in terms of efficacy and tolerance.

Adult↗
PubMed1995

Allogeneic BMT in a patient with CML and prior disseminated infection by mycobacterium avium complex.

A patient with chronic myeloid leukemia (CML) who developed a disseminated infection by mycobacterium avium complex (MAC) was successfully treated with rifampin, ethambutol, isoniazid, cycloserin and ciprofloxacin. Diagnosis was proven by histologic examination of hepatic biopsy and culture of the liver biopsy material. Two years later the patient underwent allogeneic bone marrow transplantation (BMT) from an HLA-matched sibling donor. Antimycobacterial prophylaxis to MAC with ethambutol, cycloserin and ciprofloxacin was given throughout the immediate post-transplant period. On day +25 post-BMT secondary prophylaxis was changed to ciprofloxacin and clarithromycin due to hepatic toxicity. Treatment was maintained until day 100 without side effects. There was no evidence of recurrent mycobacteriosis. Eight months after BMT the patient is well, with a good performance status and chronic graft-versus-host disease (GVHD) limited to the oral mucosa. Thus, MAC infection prior to transplant need not be a contraindication to successful BMT.

Adult↗
PubMed1995

Recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) administration after autologous bone marrow transplantation for acute myeloblastic leukemia enhances activated killer cell function and may diminish leukemic relapse.

Leukemic relapse is the major complication following autologous bone marrow transplantation (BMT) in acute myeloblastic leukemia (AML). Previously, we have shown that recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) infusion after autologous BMT has the ability to augment endogenous activated killer (AK) cell function which may play a role in the eradication of minimal residual disease. However, the clinical application of rhGM-CSF in patients with AML has been limited by its potential stimulatory effect on the malignant clone. Here we report the effect of rhGM-CSF 5 micrograms/kg/day infusion on AK cell function in 20 patients with AML undergoing autologous BMT. AK cell function was investigated before autologous BMT, during rhGM-CSF therapy and after withdrawal. In addition, its influence on the actuarial risk of relapse is analyzed and compared with a historical control group of 20 patients transplanted immediately before initiation of this study. rhGM-CSF significantly enhanced AK cell function. During rhGM-CSF treatment, median AK cell function rose from 1.8% before autologous BMT (range 0-8%) to 35% (range 3-80%) and remained increased after cessation of rhGM-CSF (median 20%; range 0-36%; P < 0.001). After a median follow-up of 24 months, the actuarial risk of relapse is 37.4% in rhGM-CSF-treated patients compared with 49.5% in controls (P = 0.05). Interestingly, none of the 7 patients with an AK cell activity > or = 20% in the first 2-5 weeks after autologous BMT have relapsed compared with 6 of 9 patients with an AK cell activity < 20% (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗