Biomedical subjects

C Brunet

Publications and source records attributed to C Brunet.

At least 127 records · Page 7Linked to original sources

PubMed1994

Stability and compatibility studies of cefaloridine, cefuroxime and ceftazidime with PVC infusion bags.

A rapid isocratic technique was developed for the analysis of three cephalosporins: cefaloridine, cefuroxime and ceftazidime in parenteral solutions using high-performance liquid chromatography (HPLC) with UV detection and C18 column. The availability and compatibility of drugs from solutions infused via plastic infusion bags through plastic administration sets have been examined. No significant drugs loss was observed during the simulated infusions (n = 4) for 1 h using PVC infusion bags and administration sets. No significant difference was found between infusion solutions (5% glucose or 0.9% NaCl). The stability of drugs was also studied in solution in PVC bags after storage at room temperature and at +4 degrees C without protection from light. The results show the stability of drugs during 24 h at room temperature and 7 d storage at +4 degrees C to be satisfactory, irrespective of the infusion solution (5% glucose or 0.9% NaCl).

Ceftazidime↗

PubMed1994

Quantification of CD24 and CD45 antigens in parallel allows a precise determination of B-cell maturation stages: relevance for the study of B-cell neoplasias.

Quantitative expression, i.e. absolute number of monoclonal antibody molecules bound per cell, was evaluated for CD24 and CD45 by flow cytometry with standards of fluorescence intensity on a panel of normal and neoplastic B cells. The CD24 antigen was expressed at homogeneous high level in fetal bone marrow and liver. Its density decreased progressively in the other normal tissues in parallel with the B-cell maturation. The ratio between CD24 density measured on fetal bone marrow B cells and that seen on adult peripheral B cells was 6:1. The CD45 antigen density was lower on fetal bone marrow cells than in the more mature stages. Fetal spleen lymphocytes and all the mature B lymphocytes displayed the same CD45 density than that seen on normal adult peripheral T cells. The CD24/CD45 antigen density ratio was precisely related to the stage of B-cell maturation. The same pattern of variation of CD24 and CD45 antigen density was seen on B-cell neoplasias, with a significantly higher value of CD24 and lower value of CD45 in acute lymphoblastic leukemias than in chronic malignancies. CD24 and CD45 antigen levels were frequently out of the range observed in the corresponding normal population. Among ALL patients, a low CD24/CD45 antigen density ratio was associated with a good prognosis. These data confirm the interest of an absolute quantitative study for widely distributed antigens.

Antigens, CD↗

PubMed1993

Comparison of the Drosophila melanogaster, human and murine Sm B cDNAs: evolutionary conservation.

To analyze the evolutionary stability of the Sm B polypeptides, the cDNA nucleotide (nt) sequence was derived for the Drosophila melanogaster Sm B polypeptide and compared to the cDNAs encoding human and murine Sm B. The three cDNAs were transcribed and translated in reticulocyte lysates followed by analysis of the synthesized proteins by SDS-PAGE. D. melanogaster B migrated at approximately 25 kDa, in comparison to 28 kDa for the murine and human B proteins, although all three proteins were immunoprecipitated by human anti-Sm autoantibodies and by the Y12 anti-Sm murine monoclonal antibody (Y12 mAb). Immunoblots and immunoprecipitations of [35S]methionine-labeled D. melanogaster S2/M3 cells confirmed the smaller size of the D. melanogaster protein, and revealed that B' was absent in this cell line, as in murine cells. In comparison to the 231 amino acids (aa) of human and murine B, the deduced sequence for the D. melanogaster clone was 199 aa (predicted M(r) of 24,598) with two 5-aa deletions and a 19-aa truncation at the 3' end, compared to the other two clones. D. melanogaster protein B shared 65% aa sequence identity with the human and mouse clones, and 80% similarity when conservative aa substitutions were noted. The C-terminal portion of the D. melanogaster protein was the most evolutionarily variable in comparison to the deduced aa sequences for the other two proteins; however, autoantigenic epitopes bound by human anti-Sm antibodies and the Y12 mAb in this region of the protein were conserved across species lines.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1993

HRF of 30 kDa: evidence for active synthesis.

A variety of mediators are involved in the pathophysiology of a number of clinical conditions. Among them histamine-releasing factors (HRF) act as secretagogue for basophils and mast cells to cause cell degranulation and histamine release. Studies on the kinetics of HRF production by activated mononuclear cells (MNC) have suggested an active synthesis of this cytokine. Using a [35S]-metabolic cell labeling method, we first analyzed the capacity of MNC from patients with allergic rhinitis to ragweed to actively synthesize HRF. We then found that stimulation of MNC with allergen promoted a synthesis of large quantities of proteins, including a protein of about 30 kDa. Secondly, we developed a method for the enrichment of HRF molecules from crude supernatants of ragweed-stimulated MNC using ion exchange and gel filtration chromatography. We observed that the yield of HRF activity is seen just before the chymotrypsinogen marker. The estimated molecular weight was 30-35 kDa.

Basophils↗

PubMed1993

Chronic idiopathic urticaria: possible contribution of histamine-releasing factor to pathogenesis.

BACKGROUND: Histamine-releasing factor was recently shown to be clinically relevant in allergic rhinitis and asthma. HRF could also be involved in the pathogenicity of chronic idiopathic urticaria (CU). The purpose of this study was to investigate the role of HRF in the pathophysiology of CU. METHODS: Blisters were induced on lesional and nonlesional skin of 12 patients with CU and on normal skin of five control subjects. HRF activity and histamine content were measured in all samples recovered from each skin site. RESULTS: Significantly more HRF was found in blister fluids from lesional skin of patients with CU as compared with nonlesional skin and skin of control subjects. In addition, histamine content in blister fluids from affected skin of patients with CU was significantly higher in comparison with both nonlesional skin of patients with CU and skin of control subjects. HRF activity was also higher in blister fluids from nonlesional skin of patients with CU than that of control subjects, in spite of equivalent histamine content. CONCLUSION: These data suggest that the inflammatory reaction found in CU disease is associated with the cutaneous release of HRF.

Adult↗

PubMed1993

[Treatment of splenic trauma. Apropos of a series of 52 cases].

Our serial is composed of 52 cases analysed after a backward upper two years. Because the happening of flashing infections sometimes many years after splenectomy, the therapic gesture must be prioritally leaded by splenic conservation, possible in all cases except the lesions of type 4 (spleen burst or pedicule extract): the perisplenic resorbable prothesis is a precious contribution. The analysis of results confirms the reliability of splenic conservation (47%) with 91% excellent results.

Accidents, Occupational↗

PubMed1993

Comparison of in vitro effects of two thiol-containing drugs on human neutrophils hydrogen peroxide production.

During inflammatory disorders, potentially destructive reactive oxygen species, especially hydrogen peroxide, are produced by activated phagocytic cells. It was demonstrated in vitro that mesna and N-acetylcysteine (NAC), mucolytic thiols, have antioxidant properties. An estimation was made of the 50% inhibitory concentration (IC50) of mesna and NAC for PMA-induced H2O2 production by human neutrophils, the results being 70 mcM and 77 mcM, respectively. The mechanism which governs mesna and NAC reactions results from a scavenging effect of H2O2: the calculated IC50s of this effect were 30 mcM and 42 mcM, respectively, in free cellular experimentation. The results suggest that mesna and NAC might be used as antioxidants in aerosols to prevent tissue damage inflicted by this reactive oxygen species, especially in the lungs.

Acetylcysteine↗

PubMed1993

[The so-called "celio-mesenteric button-hole" region, an anatomico-surgical study].

Average biometric values of the abdominal aorta and its collaterals, together with their variations, were studied during 80 multiple organ biopsies and 60 cadaver dissections. Two morphotypes were detected raising technical and tactical problems during multiple organ biopsies, particularly since this region includes the origin of the renal arteries. The left transplexic approach provides enhanced safety during control of arterial ostia.

Celiac Artery↗

PubMed1992

Stability and compatibility of four anthracyclines: doxorubicin, epirubicin, daunorubicin and pirarubicin with PVC infusion bags.

A rapid isocratic technique was developed for the analysis of four anthracyclines (doxorubicin, epirubicin, daunorubicin and pirarubicin) in parenteral solutions using high pressure liquid chromatography (HPLC) with fluorescence detection and a C18 Hypersil ODS column. The availability and compatibility of these drugs from solutions infused via PVC infusion bags through PVC administration sets have been examined. No significant drug loss was observed during simulated infusions (n = 4) for 24 h using PVC infusion bags and administration sets. No significant difference was found between infusion solutions (5% glucose or 0.9% NaCl), except for pirarubicin. The reconstitution of pirarubicin in 0.9% NaCl was impossible, because we observed a precipitation of the compound in solution. The stability of the drugs was also studied in solution, in PVC bags after storage at 4 degrees C with protection from light. The results show the stability of doxorubicin, epirubicin and daunorubicin during 7 days of storage to be satisfactory, irrespective of the infusion solution (5% glucose or 0.9% NaCl). In the case of pirarubicin, the stability of the drug was satisfactory during 5 days of storage in 5% glucose, but beyond, we observed a degradation of the compound with formation of doxorubicin in the infusion solution.

Antibiotics, Antineoplastic↗

PubMed1992

Chronic idiopathic urticaria: profiles of skin mast cell histamine release during active disease and remission.

Chronic idiopathic urticaria (CIU) is characterized by the increased releasability of histamine by mast cells in normal-appearing skin. In active CIU, this abnormality is consistently present. To determine if this finding subsides when the disease goes into remission phase, we analyzed the histamine secretion in patients with CIU in remission (CIUR) compared with that of patients with CIU and in normal control (NC) subjects, with the skin-chamber technique. The profiles of histamine release in sites challenged with compound 48/80 were significantly different in the groups with CIU and CIUR. Furthermore, patients with CIUR did not differ from NC subjects in terms of histamine releasability under compound 48/80 stimulation (p greater than 0.1). These data suggest that the state of excessive skin mast cell sensitivity is a reversible and transient phenomenon in CIU disease.

Analysis of Variance↗

PubMed1992

Allergic rhinitis to ragweed pollen. I. Reassessment of the effects of immunotherapy on cellular and humoral responses.

This work presents a double-blind, placebo-controlled study of 27 patients with allergic rhinitis to ragweed who received preseasonal desensitization immunotherapy [IT] with alum-precipitated aqueous ragweed extracts. We reassessed the following parameters in relation to clinical responses: clinical scores, nasal reactivity to a provocative dose of ragweed causing a 75% fall in airflow rate (PD75), ragweed IgE and IgG, and ragweed-induced basophil histamine release (BHR). First, the nasal PD75 correlated with the severity of nasal symptoms (p less than 0.05). Second, we confirmed a significant symptomatic improvement in the IT-treated group either by clinical scores (p less than 0.05) or the prevention of the seasonal fall of the PD75 (p less than 0.005). Also, IT reduced the seasonal rise of IgE (p less than 0.02) and induced an increase in IgG (p less than 0.01) and a decrease in BHR (p less than 0.03). There was a significant correlation between IgE and BHR (r = 0.80; p less than 0.01). After selecting out the effects of IgE, the BHR was still higher in the placebo-treated group than in the IT-treated group (p less than 0.02), suggesting the involvement of other modulating factors. Symptomatic improvement after IT correlated only with the summation of both IgE and BHR (PD75; r = 0.64; p less than 0.005). This observation suggests that the severity of clinical symptoms is determined by several interacting factors and not by the antibody response alone.

Adult↗

PubMed1992

Allergic rhinitis to ragweed pollen. II. Modulation of histamine-releasing factor production by specific immunotherapy.

A number of cytokines, including histamine-releasing factors (HRFs), have a role to play in IgE-mediated asthma. However, the influence of HRF in allergic rhinitis without asthma remains to be revealed. This article presents a double-blind, placebo-controlled study on the role of HRF in ragweed-allergic rhinitis and its modulation by natural pollen exposure and specific immunotherapy (IT). Twenty-seven patients allergic to ragweed were randomly assigned to receive either preseasonal alum-precipitated aqueous extracts of ragweed or placebo. Before the onset of therapy and during the ragweed-pollen season, subjects were evaluated for each of the following: clinical scores, ragweed IgE and IgG antibody levels, and spontaneous and allergen-driven HRF production. Thirteen nonatopic volunteers were also studied in the same protocol. First, before the initiation of therapy, more HRF was produced by both unstimulated and ragweed-stimulated mononuclear cells (MNCs) of atopic subjects as compared to MNCs of nonatopic subjects. Second, MNCs of the placebo-treated group produced significantly more spontaneous and ragweed-specific HRF during the pollen season compared to the preseasonal values. Finally, specific IT not only improved the clinical manifestation of allergy but also prevented the seasonal rise of spontaneous and ragweed-driven HRF production, along with a well-known change in other immunologic parameters associated with successful IT.

Adult↗

PubMed1992

[Gangrene of the perineum. Plea for a standardized therapeutic management apropos of 50 cases].

From 1988 to 1992, 50 cases of perineal gangrene were treated with a therapeutic protocol combining: a) repeated extensive excisions, b) hyperbaric oxygen therapy, even before surgery if this was possible, and c) intensive care. The mortality rate was 24% (12/50). It was even higher in patients admitted more than 6 hours after diagnosis. The average stay in hospital was of 20 (+/- 2) days. Four patients presented with residual signs. Twenty-eight (56%) had had colostomy for lesions originating in the rectum or threatening the anal margin; 9 of these patients died, while gastrointestinal continuity was restored in another 17 cases. There were three predictive factors of survival in this series: a) early diagnosis and treatment, b) severity index on admission, c) some associations of bacteria.

Adult↗

PubMed1991

Rapid determination by high performance liquid chromatography of di-2-ethylhexyl phthalate in plasma stored in plastic bags.

A rapid sensitive technique was developed for the analysis of di-2-ethylhexyl phthalate (DEHP) in plasma stored in plastic bags by using high performance liquid chromatography (HPLC) with UV detection and a Hypersil ODS column. The compound was easily and efficiently extracted with a mixture of sodium hydroxide and acetonitrile, which allowed the deproteinization of plasma samples. The recovery was greater than 95% and the intra- and inter-assay coefficients of variation were better than 6.5%. The results obtained showed that the amount of DEHP accumulated in plasma varied according to different parameters and depended on the storage conditions (time, temperature and shaking) and also on the lipid content of the stored plasma and the sterilization process of the PVC bags.

Blood Specimen Collection↗

PubMed1991

3-Thienyl- and 3-furylaminobutyric acids. Synthesis and binding GABAB receptor studies.

Baclofen (beta-(p-chlorophenyl)-GABA) is a selective agonist for the bicuculline-insensitive GABAB receptor. The search for new compounds that bind to the GABAB receptor is very important to clarify structural requirements. We report herein the synthesis and the binding studies of variously substituted 3-thienyl- and 3-furylaminobutyric acids. 4-Amino-3-(5-methyl-2-thienyl)butyric acid (5d) and 4-amino-3-(5-chloro-2-thienyl)butyric acid (5h) are potent and specific ligands for GABAB receptor. The IC50 values for the displacement of (R)-(-)-[3H]baclofen are 1.34 and 0.61 microM for 5d and 5h, respectively, as compared to 0.33 microM for baclofen.

Animals↗

PubMed1991

Pharmacokinetics of epirubicin after intravenous administration: experimental and clinical aspects.

A method is described for the extraction and determination of epirubicin and its main metabolites epirubicinol and glucuronides in plasma, using high performance liquid chromatography (HPLC) with fluorescence detection. The extraction was performed with column Sep-Pak C18, which allowed a quantitative recovery of compounds. This method was used first in studies performed in five rabbits after intravenous administration of 3 mg/kg epirubicin, and later in a cancer patient, who received 50 mg/m2 epirubicin in rapid intravenous infusion. Although not statistically significant, kinetics of epirubicin were fitted in both cases to a tri-exponential model. Common metabolites were detected in rabbits and human, particularly the glucuronides. However, kinetics of epirubicin glucuronides and epirubicinol glucuronides were very different. Production and elimination were very fast in rabbit at very low levels and were undetectable two hours after administration, while in human, elimination was slower and greater amounts were detected 1-2 h after administration. The rabbit seemed to be an interesting animal species for pharmacokinetic studies because of easy blood sampling, detection of small amounts of glucuronides and because of a good fit to tri-exponential kinetics model.

Animals↗

PubMed1990

Rapid quantitative determination of epirubicin and its metabolites in plasma using high performance liquid chromatography and fluorescence detection.

A rapid sensitive and selective isocratic technique was developed for the analysis of plasma epirubicin and three of its known fluorescent metabolites epirubicinol, 4'-O-beta-D-glucuronyl-4'-epidoxorubicin and 4'-O-beta-D-glucuronyl 1,3-dihydro-4'-epidoxorubicin, with daunorubicin as an internal standard, by using high performance liquid chromatography (HPLC) with fluorescence detection and a 'Hypersil ODS' column. The drugs were easily and efficiently extracted with a Sep-Pak C18 cartridge and the mean recoveries were greater than 85%. Intraassay and Interassay coefficients of variation (plasma samples) were better than 8.25%. An example of pharmacokinetic study obtained in a cancer patient after intravenous injection of epirubicine is described.

Chromatography, High Pressure Liquid↗

PubMed1990

Familial hypermethioninemia partially responsive to dietary restriction.

Hypermethioninemia and absolute methionine intolerance were observed in three siblings. These patients had several peculiar clinical features comprising failure to thrive, mental and motor retardation, facial dysmorphy with abnormal hair and teeth, and myocardiopathy. Hepatic S-adenosylhomocysteine hydrolase activity was decreased by 80% in the three children. These clinical and biochemical features differ from those of hypermethioninemias previously described, and thus represent a new form of inherited disorder of methionine metabolism. Whether S-adenosylhomocysteine hydrolase deficiency is primary or secondary to an unknown metabolic defect remains to be determined.

Adenosylhomocysteinase↗