Search PubMed⌕ Search

Biomedical subjects

R Robert

Publications and source records attributed to R Robert.

At least 91 records · Page 5Linked to original sources
PubMed1995

Purification of a Candida albicans germ tube specific antigen.

In a previous work, Marot-Leblond et al. identified a Candida albicans germ tube-specific antigen by the use of a monoclonal antibody (mAb 3D9.3). In the present report, we used a two-step procedure to obtain a purified preparation of this antigen from a Zymolyase extract of Candida albicans germ tubes. The extract was first fractionated by gel filtration chromatography. The immunoreactive fractions were pooled, and the 3D9.3 antigen was further purified by hydrophobic interaction chromatography using a Phenyl-superose column. Analysis by SDS-PAGE, immunoblotting and Concanavalin A staining, revealed a single, polydisperse band ranging from 110 to 170 kDa. The antigen was purified 126-fold by protein content and 16.4-fold by carbohydrate content. Recovery of the antigen was 6.8% following the two-step purification.

Animals↗
PubMed1994

Enhancement of hypoxemia by right-to-left atrial shunting in severe asthma.

We report two cases of severe hypoxemia due to right-to-left shunt in acute asthmatic patients. During acute asthma, the transmural right atrial pressure can be higher than left atrial pressure during inspiration and then induce a right-to-left shunt through inter-atrial communication leading to hypoxemia. Contrast echography as well as Doppler analysis can easily confirm the diagnosis.

Acute Disease↗
PubMed1994

[Rhabdomyolysis in community-acquired pneumonia].

Several cases of rhabdomyolysis associated with pneumococcal pneumonia have been recently reported. However their significance have been poorly investigated. In this retrospective study, we have compared the patients admitted in ICU for acute community-acquired pneumonia with or without rhabdomyolysis (group A: CPK > or = 1,000 Ul/l and group B: CPK < 1,000 Ul/l). Among the 41 patients of the study, 12 (29%) belonged to the group A (CPK = 1,852 +/- 535 Ul/l) and 29 (71%) to group B (CPK = 190 +/- 35 Ul/l). Neither the initial severity, nor renal impairment were different in the two groups. However the mortality was significantly higher in the group A (4/12) than in group B (2/29) (P < 0.05). In this study, pneumonia is frequently associated with rhabdomyolysis, without etiologic significance. In patients with pneumonia, rhabdomyolysis seems to be a bad prognostic indice unrelated with renal impairment.

Adult↗
PubMed1994

Modulation of cell surface-associated mannoprotein antigen expression in experimental candidal vaginitis.

The monoclonal antibody (MAb) AF1 recognizes an oligosaccharide epitope present on highly immunogenic and immunomodulatory mannoproteins (MP) of Candida albicans. The expression of this epitope (AF1-MP) during experimental candidal vaginitis was studied in two strains of C. albicans (3153 and CA-2) which were equally vaginopathic but differed in the mode of hypha formation in the vagina. In both strains, immunofluorescence of vaginal samples, taken 1 h after challenge, revealed an intense, MAb AF1-specific labelling of the yeast cells. This labelling was very scarce in fungal cells taken at 24 h and on subsequent days during the development of filamentous forms. Electron-microscopic gold immunolabelling observations showed that molecules carrying AF1-MP spanned the entire cell wall in the initial yeast cells but were absent on the cell surface and in the outermost, capsular layer of the cell wall of the germ tubes and filamentous forms. In both strains, at any time and for any form of intravaginal growth, AF1-MP was clearly expressed in the cytoplasm and cytoplasmic vesicles, and was fully incorporated into the inner layers of the cell wall. As seen by immunofluorescence, the vaginal fluid from C. albicans-infected rats did not hinder the expression of AF1-MP on the yeast cells surface in vitro. In electron-microscopic gold immunolabelling, a hypha-specific MAb (3D9) labelled the surface of the hyphal but not of the yeast cells of C. albicans harvested from rat vagina. Overall, these data strongly suggest that cell surface expression of MP antigen is modulated during intravaginal growth and morphogenesis of C. albicans.

Animals↗
PubMed1994

A kidney biopsy is clearly mandatory to confirm the indication of plasma exchanges in adult haemolytic uraemic syndrome.

In case of haemolytic uraemic syndrome, it is not always possible to identify on a pure clinical basis the different kidney lesions responsible for the syndrome. We report a series of six cases without thrombotic microangiopathy, which emphasizes the need to perform a kidney biopsy as early as possible, so as to confirm the actual usefulness of plasma exchanges (PE) commonly carried out in emergency in every case of adult haemolytic uraemic syndrome. PATIENTS AND METHODS--Files of patients who were treated for haemolytic uraemic syndrome over the past 14 years were reviewed. Patients in whom thrombotic microangiopathy had been excluded by renal histology data were studied. Every patient was promptly treated with hypotensive drugs, so as to obtain blood pressure levels not exceeding 160-90 mmHg. Dialysis was performed in two patients. Daily PE with fresh frozen plasma were carried out in three patients as early as the first 24 hours after admission, and discontinued immediately after thrombotic microangiopathy could be excluded. RESULTS--All the patients met the usual criteria for diagnosis of haemolytic uraemic syndrome. Elevated liver enzymes were also found in the four cases of preeclampsia, consisting with diagnosis of severe HELLP syndrome. One case was associated with oestrogen therapy. Glomerular lesions were seen in four patients: slight endotheliosis in three cases of preeclampsia; marked lesions of IgA mesangial deposits in the patient who had been treated by contraceptive pill. Three patients had acute tubular necrosis and three had intense lesions of nephrosclerosis. Complete remission was obtained in every case of preeclampsia. Renal failure persisted in two cases (IgA glomerulopathy and one case of nephrosclerosis). DISCUSSION--The histological heterogeneity of haemolytic uraemic syndrome has been already well demonstrated. Typical lesions of thrombotic microangiopathy are usually classified into predominant glomerular lesions, pure arteriolar and mixed lesions. In other cases, thrombotic microangiopathy is not found: kidney lesions may be glomerular (endotheliosis, various subtypes of glomerulonephritis), tubular (acute tubular necrosis) or vascular (nephroangiosclerosis). In every aetiological circumstance, several different lesions may be found together. The usefulness of PE has been proved in thrombotic thrombocytopenic purpura, has been suggested in haemolytic uraemic syndrome and to a lesser extent in persistently severe HELLP syndrome. Unfortunately, none of these reports gave any information about kidney lesions responsible of acute renal failure. CONCLUSION--The haemolytic uraemic syndrome is a syndrome: thrombotic microangiopathy has to be proven when treatment by PE is planned, except in some severe clinical circumstances.

Adult↗
PubMed1993

Anatomical study of five prenataly diagnosed sternopagus twins.

Among conjoined twins (1 out 50000 births), thoracopagus occurs most frequently and is generally lethal. Our anatomical study of five sets of sternopagus twins (3 female, 2 male) was performed to determine the ability of prenatal sonography to detect these anomalies. Autopsy in four cases revealed identical malformations: common sternum, single malformed heart, joined hepatic parenchyma, and a common small bowel leading to a cystic dilatation situated on the ileal segment at the end of the superior mesenteric artery. The diagnosis of conjoined twins was made in all cases by prenatal sonography at the mean time of 24.6 gestation weeks (range 19-34). The malformations detected by prenatal sonography were a single cardiac mass (all cases), joined hepatic parenchymas (3 cases), and an ileal cystic dilatation (1 case). Pregnancy was terminated in four cases. In one case cesarean delivery was performed, and the infants died 48 hours later. Prenatal sonography currently seems to be the best examination for diagnosis of sternopagus twins and the detection of lethal malformations thus allowing interruption of pregnancy.

Abortion, Eugenic↗
PubMed1993

[A fatal case of viper bite in an adult in France].

Vipera bites in France are supposed to be benign. We report here, the case of a snake bite with fatal outcome due to hypoxemia and shock, occurring in a young woman without previous disease. This case could lead to reevaluate the indication of antivenomous serotherapy in the severe envenomations. However the tolerance of the new serums has to the confirmed.

Adult↗
PubMed1993

Monoclonal antibodies against methionyl recombinant human prolactin.

Hybridoma cell lines producing monoclonal antibody (Mab) against recombinant human prolactin (rhPrl) were established from fusion between X63-Ag8 myeloma cells and Balb/c mice splenocytes. Four Mabs numbered I to IV were selected by ELISA, purified and characterized. All these Mabs were of the Ig1 kappa isotype and able to recognize oxidized as well as reduced rhPrl. As shown by a competitive inhibition assay, Mab IV did not compete with any of the three others. Moreover, both rhPrl and hPrl extracted from human pituitaries, were recognized equally by this Mab. Properties displayed by Mab IV make it very attractive for the evaluation of prolactin levels by sandwich immunoassays.

Animals↗
PubMed1993

Identification and immunochemical characterization of a germ tube specific antigen of Candida albicans.

Germ tube specific fractions of the dimorphic pathogenic fungus Candida albicans were fractionated according to their ability to link to fibrinogen. These fibrinogen binding factors were used as immunogens to prepare monoclonal antibodies (mAbs) with BALB/c mice. Among the resulting mAbs, one (mAb 3D9.3) was shown by indirect immunofluorescence to be specific to the surface of the mycelial phase of the C. albicans species. No labelling of the cell wall of any other Candida species was observed. This morphological shape specificity was confirmed by immunoblotting where a polydispersed high molecular mass component was identified. The molecular mass varied with the extraction procedure used; over 210 kDa with EDTA-2ME treatment, and ranging from 110 to 220 kDa after Zymolyase digestion. This phase-specific epitope was sensitive to proteolysis with pronase E, proteinase K and trypsin, but not to periodate treatment. Further purification of this material would allow further development of new serodiagnostic assays that might be more specific for invasive disease than currently available tests.

Animals↗
PubMed1993

Characterization of Candida albicans cell wall antigens with monoclonal antibodies.

The antigenic composition of Candida albicans is very complex. In order to study the antigenic relationship between blastoconidia and germ tubes of C. albicans, we produced several monoclonal antibodies and analyzed their reactivity against cell wall antigens either in intact cells or in cells treated with dithiothreitol. Overall, four types of reactivity were found. Monoclonal antibodies 3D9 and 15C9 stained the germ tubes only when tested by indirect immunofluorescence. However, they showed a different reactivity by immunoblotting. Monoclonal antibody 3D9 reacted with antigens with molecular masses of > 200 and 180 kDa specifically expressed in the germ tube. Monoclonal antibody 15C9 reacted with antigens of 87, 50, and 34 kDa present in the germ tube extract and with antigens of 92, 50, 34, and 32 kDa present in the blastoconidium extract. The reactivity of blastoconidia treated for different times with dithiothreitol with these monoclonal antibodies was also studied by enzyme-linked immunosorbent assay. The reactivity of monoclonal antibody 3D9 did not significantly change during the cell wall extraction. However, the reactivity of monoclonal antibody 15C9 was increased for blastoconidia extracted for 60 min and decreased markedly for blastocondia extracted for 120 min. Monoclonal antibody G3B was nonreactive by indirect immunofluoresence but reacted with antigens of 47 and 38 kDa present in the germ tube extract and with an antigen of 47 kDa present in the blastoconidium extract. Monoclonal antibody B9E stained both morphological phases by indirect immunofluorescence. By immunoblotting, it reacted with antigens of > 70 kDa present in the germ tube extract and with antigens of > 63, 56, 47, and 38 kDa present in the blastoconidium extract. Based on the results presented in this study, four types of antigens are described. Type I antigens are expressed on the outermost layers of the germ tube cell wall only. Type II antigens are expressed both on the germ tube cell wall surface and within the blastoconidium cell wall. Type III antigens are found within the cell wall of both blastoconidia and germ tubes. Type IV antigens are expressed on both the blastoconidium and germ tube surface. Two types more can be hypothesized for antigens expressed on the blastoconidium cell surface and within the germ tube cell wall (type V) and for those expressed on the blastoconidium surface only (type VI).

Animals↗
PubMed1993

Study of antiatherogenic properties of indapamide in a pharmacologic model.

A localized atheromatous plaque was induced in rabbits after transmural electrical stimulation of the carotid and a cholesterol-rich diet (1.33% cholesterol) for 4 weeks. This model was used to investigate the antiatherogenicity of indapamide. The treatment given per os started 14 days before the stimulation period. Animals were divided into six groups: group 1 (control) received gelatin 2%, group 2 received hydrochlorothiazide at 20 mg/kg/day, group 3 was treated with flunarizine at 25 mg/kg/day, and groups 4, 5, and 6 received indapamide at 0.3, 1, and 3 mg/kg/day, respectively. During the experimental period, all rabbits showed similar weight gain, regardless of the treatment. Image analysis showed an antiatherogenic effect for indapamide (0.3 mg/kg/day) characterized by a reduction in the number of cell layers (NCL; 10.5 +/- 1.8 vs. 18.0 +/- 2.9; p < 0.05) and in the intima/media area ratio (I/M; 17.5 +/- 4.5 vs. 42.7 +/- 7.0%; p < 0.01). Indapamide appeared to be more active than the reference drug flunarizine (NCL = 14.2 +/- 2.5, N.S.; I/M = 24.5 +/- 4.3, p < 0.05). The maximum effect occurred at the lowest dose tested (0.3 mg/kg/day). The reason for the loss of antiatherogenic activity of indapamide at higher doses is discussed. Hydrochlorothiazide did not show any effect on the formation of the atheromatous plaque.

Animals↗
PubMed1993

Different effects of interleukin-1 on reactivity of arterial vessels isolated from various vascular beds in the rabbit.

During septic shock, arterial smooth muscle is thought to be hyporeactive to vasoconstrictors. This hyporeactivity, however, seems to be different from one vascular bed to another. Interleukin-1 (IL-1), which is released during septic shock, might play a role in the different regional vascular responses to norepinephrine. Thus, the aim of the present study was to examine in vitro the effect of IL-1 on the response to norepinephrine of arteries isolated from different territories in the rabbit. Three types of responses were identified: IL-1 decreased NE-induced contraction by 54% in aorta, 42% in carotid artery, 54% in pulmonary artery, and 18% in renal artery; and IL-1 was devoid of significant effect in hepatic and mesenteric arteries; and IL-1 increased NE-induced contraction by 25% in femoral arteries. In conclusion, IL-1 might contribute to the regional blood flow abnormalities during septic shock.

Animals↗
PubMed1992

Interleukin-1 impairs both vascular contraction and relaxation in rabbit isolated aorta.

Incubation of rabbit aortic rings with interleukin-1 (100 U/ml) in vitro led to a depressed contractile response to norepinephrine, whether the endothelium was present or not. In both cases norepinephrine-induced contraction was restored in the presence of NG-methyl-L-arginine (300 microM), an inhibitor of nitric oxide synthesis. In interleukin-1-treated rings precontracted with norepinephrine (1 microM), the relaxing response to acetylcholine was totally suppressed independently on the presence of endothelium. High concentrations of acetylcholine (greater than 1 microM) induced a slight contraction which was of lower amplitude than that obtained in control endothelium-denuded rings and was increased in the presence of NG-methyl-L-arginine. These results show that interleukin-1 (i) affects not only vascular contraction but also relaxation and (ii) involves both endothelial and non-endothelial factors. These observations suggest an impairment of the whole vascular reactivity during septic shock.

Acetylcholine↗
PubMed1992

[Pain and its pathways. A study for therapeutic action].

Pain is as old as mankind. It has a threshold beyond which nobody can escape it. Pain is a biological and physiological phenomenon, an integrated part of our body and ego. Will all our efforts eventually make it disappear? Is its disappearance desirable? Pain is one of the major expressions of sensation. It is integrated by the central structures and expressed as a behavior of avoidance or attenuation of the effects produced by the cause of pain. The study of this behavior and of the transmission of the pain message corresponds to the study of how to fight against this message, which means that it should logically lead to the treatment of pain.

Analgesia↗