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Biomedical subjects

B Guidet

Publications and source records attributed to B Guidet.

At least 55 records · Page 3Linked to original sources
PubMed1994

Generalized air cysts complicated by fatal bilateral pneumothoraces in a patient with AIDS-related Pneumocystis carinii pneumonia.

We describe a case of air cyst lesions in an AIDS patient suffering from Pneumocystis carinii pneumonia. This case is unique because these lesions were generalized to both lungs and initially well tolerated. Pathologic examination revealed extensive tissue invasion by P carinii. The prognosis was complicated by bilateral pneumothoraces. Surgical right pleurodesis allowed lung re-expansion but did not prevent recurrence of fatal contralateral pneumothorax.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Enteral nutrition in patients with chronic obstructive bronchopathy treated by artificial ventilation. Effect of conventional feeding on anthropometric and biochemical parameters].

The influence of conventional gastric tube feeding on anthropometric and biochemical parameters was studied prospectively during 12 months in 14 patients with chronic obstructive lung disease put on mechanical ventilation for respiratory failure. The anthropometric parameters were: body weight, tricipital skin fold, brachial and brachial muscle circumferences. The biochemical parameters included albumin, transferrin, retinol binding protein, transthyretin, acid alpha-1-glycoprotein, C-reactive protein, fibronectin and amino acids in blood, and 3-methylhistidine in urine. Measurements were performed on inclusion, then every 3 days until D15. After 15 days of a nutrition bringing 28.8 +/- 8.9 calories/kg/day and 13.9 +/- 2.2 grams of nitrogen per day, no improvement in anthropometric parameters was observed. On D0, comparisons with healthy controls showed that visceral serum proteins levels were significantly lower and inflammatory proteins levels significantly higher (P < 0.05); the levels of protein metabolism markers were higher, but not significantly, and those of the principal glucose-forming amino acids were significantly lower (P < 0.01). On D15, comparisons with the initial values showed that the values of retinol binding protein and transthyretin were increased (P < 0.05 and 0.01 respectively), whereas the values of the other visceral proteins were little modified; yet their concentrations remained significantly lower than those found in controls, except for the retinol binding protein. Inflammatory proteins levels were high, with a significant (P = 0.05) difference for the acid alpha-1-glycoprotein, and the patients remained in slight catabolism while their nitrogen balance was positive. These results should encourage to carry out studies on the qualitative composition of artificial nutrition in order to optimize its effectiveness in the treatment of these patients.

Aged↗
PubMed1993

[Interleukins and TNF in septic shock].

Tumor necrosis factor alpha (TNF alpha) and interleukins (IL) are the principal cytokines involved in the clinical and biological manifestations of septic shock. Their secretion are triggered mainly by endotoxin, but products of Gram positive cocci as well as of virus or of parasites are equally effective. Cytokines represent a normal protective defense against infection, but an excessive production have toxic effects. In experimental models of endotoxinemia, TNF alpha is the first cytokine produced, then IL-1 and IL-6. Other inflammatory mediators are secreted later. Thus it seems logical to try to modulate cytokine production or actions. However, several questions remains since experimental data are sometimes not applicable too human diseases, cytokines are organised in a network with several interaction. It is too early to propose routine anti-cytokines drugs in septic shock.

Animals↗
PubMed1993

[Therapeutic perspectives of severe infectious states].

Mortality from sepsis is still unacceptably high which justifies a new therapeutic approach complementary of antibiotics and symptomatic treatment. Recent advances in the understanding of sepsis and septic shock opened new fields of therapeutic intervention. Nevertheless, there are so many potential targets that is hard to make a choice for evaluation of these new agents: anti-endotoxin (monoclonal antibodies, lipid A analogs, BPI), anticytokines (monoclonal antibodies, soluble receptors, IL-1 receptor antagonist), anti-inflammatory agents (non-steroidal anti-inflammatory agents, anti-PAF, reactive oxygen radicals scavengers...), extracorporeal removal of toxic molecules, inhibition of the adhesion of polymorphonuclear leucocytes on endothelial surface, optimisation of general and regional circulation. The use of these new and often costly drugs must rely on multicenter randomized clinical trials since extrapolation to the human of experimental data gathered in animal studies are hazardous.

Cytokines↗
PubMed1993

Prospective evaluation of self-extubations in a medical intensive care unit.

OBJECTIVE: To evaluate the incidence, associated factors and gravity of self-extubations. DESIGN: Prospective study about all patients intubated over an 8 month period. SETTING: A medical intensive care unit of a University Hospital. PATIENTS: Patients were divided into two groups: self-extubated and those that did not. The self-extubations were separated into deliberate acts by the patients and accidental. RESULTS: 24 of the 197 patients included presented a total of 27 extubations (12%). There were 21 deliberate incidents and 6 accidental. The only differences between the cases and the rest of the population were a higher mean age (67 vs 59 years) and a larger proportion of chronic respiratory failure (66% versus 35%). Reintubation was necessary in 20 cases (74%) within 30 min in 16 cases. The main indication for reintubation was acute respiratory distress (90%). Reintubation was associated with one death. CONCLUSION: Self-extubation is a frequent and serious complication of mechanical ventilation. Deliberate self-extubation, the most frequent type of incident could possibly be reduced by better sedation of agitated patients and accidental self-extubation by better training of the nursing staff.

Adult↗
PubMed1993

Gentamicin-induced mobilization of iron from renal cortical mitochondria.

Iron, presumably by participating in generation of hydroxyl radical or other oxidant species or initiation of lipid peroxidation, has been shown to play an important role in several models of tissue injury, including acute renal failure induced by the antibiotic gentamicin. However, the sources of iron remain unknown. Rat renal mitochondria incubated at 37 degrees C with gentamicin resulted in a time- (15-60 min) and a dose-dependent (0.01-5 mM) iron release as measured by formation of iron-bathophenanthroline sulfonate complex FeII-(BPS)3 [at 60 min, control: 1.2 +/- 0.1 nmol/mg protein, n = 7; gentamicin (5 mM): 5.1 +/- 0.4 nmol/mg protein, n = 7]. No formation of FeII(BPS)3 complex was detected in the absence of mitochondria or when incubations were carried out at 0 degrees C. Similar results were obtained when 2,2'-dipyridyl, another iron chelator, was used for measurement of iron release. On the basis on our previous study that gentamicin enhances generation of hydrogen peroxide by renal cortical mitochondria, we examined whether effect of gentamicin on iron release is mediated by hydrogen peroxide. Catalase (which decomposes hydrogen peroxide), but not heat-inactivated catalase, as well as pyruvate, a potent scavenger of hydrogen peroxide, prevented gentamicin-induced iron mobilization. Superoxide dismutase, a scavenger of superoxide anion, or hydroxyl radical scavengers (dimethylthiourea or sodium benzoate) had no effect. Taken together, the data with scavengers indicate that gentamicin-induced iron mobilization from mitochondria is mediated by hydrogen peroxide.

2,2'-Dipyridyl↗
PubMed1993

Four markers of collagen metabolism as possible indicators of disease in the adult respiratory distress syndrome.

During the adult respiratory distress syndrome (ARDS), an irreversible fibrotic process can occur extremely rapidly. To establish indices of ARDS in pneumonia as well as the severity of the lung fibrosis, we have undertaken for the first time a study of four markers of collagen metabolism obtained from both bronchoalveolar lavage fluid (BALF) and serum: Type I (CI), Type III (CIII), N-terminal peptide of Type III procollagen (PIIINP), and galactosylhydroxylysylglucosyltransferase activity (GGT). We studied 61 patients (13 coma controls, 29 with pneumonia, and 19 with ARDS). In BALF, the average values of CI, CIII, PIIINP, and GGT were significantly higher in ARDS than in the control patients. The values for patients with pneumonia, although increased, were significantly lower than those in ARDS for CI, CIII, and PIIINP. In serum, the mean CI and PIIINP were significantly increased in pneumonia and ARDS, but the mean CIII was significantly increased only in ARDS compared with the control group. Significant positive linear correlations were observed for ARDS between CI and CIII or PIIINP and CIII in BALF and serum. Such correlations were observed for pneumonia only in serum. Molecular mass determinations demonstrated that CI- and CIII-related antigens in BALF were essentially intact triple helices of collagens or procollagens. Among patients with histologically defined interstitial fibrosis, the level of PIIINP in BALF was significantly higher for those with an additional intraalveolar fibrosis. In conclusion, measurements of these collagen markers may be useful for assessing disease activity and reflecting the flux of collagen molecules in the lung.

Adult↗
PubMed1993

Mechanical ventilation for Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome. Is the prognosis really improved?

The mortality rate among patients with human immunodeficiency virus (HIV) requiring mechanical ventilation (MV) for acute respiratory failure (ARF) secondary to Pneumocystis carinii pneumonia (PCP) is still a matter of discussion. For some authors, it is in the 50 percent range, while for others the prognosis is grim, with virtually no survivors. The aim of this retrospective study conducted between January 1987 and January 1992 was to analyze the outcome of such patients. We studied 33 patients, 29 men and 4 women (38.6 +/- 9.9 years, 21 homosexuals, 8 intravenous drug users, 3 transfusion related, 1 heterosexual) infected by HIV for at least 19.7 +/- 21.6 months. It was the first PCP episode in all but 2 patients and the diagnosis was made by bronchoalveolar lavage (n = 32) or lung biopsy specimen (n = 1). Only three patients were receiving primary prophylaxis for PCP (trimethoprim-sulfamethoxazole [TMP-SMZ], n = 2; pentamidine, n = 1). Pneumocystis carinii pneumonia was the first manifestation of AIDS in nine patients. The duration of symptoms prior to treatment was 19.6 +/- 11.3 days. At the time of hospital admission, laboratory findings were as follows: PaO2 = 40.7 +/- 7.8 mm Hg on room air; serum LDH = 1,172 +/- 792 IU/L; T4 cell count = 60.2 +/- 67/mm3. Mechanical ventilation was always required for ARF, which was never induced by bronchoscopy. The interval between treatment and MV was 8.1 +/- 6.5 days and the duration of MV was 11.4 +/- 9.9 days. The patients were classified into 3 groups on the basis of the duration and type of treatment before MV, as follows: group 1, n = 10: TMP-SMZ (20-100 mg/kg) IV and methylprednisolone (MP) < 5 days before MV; group 2, n = 4: TMP-SMZ > or = 5 days and MP < 5 days; group 3, n = 19: TMP-SMZ and MP > or = 5 days before MV. (The MP dose was as follows: 240 mg/d once a day from day 1 to day 3; 120 mg/d from day 4 to day 6; and 60 mg/d from day 7 to day 9.) Despite MV, TMP-SMZ, and MP, death secondary to PCP-related ARF occurred in 81.9 percent of patients, 20 +/- 4.8 days after the beginning of treatment and 11.4 +/- 9.9 days after the beginning of MV. Six patients survived, five in group 1 and one in group 3.(ABSTRACT TRUNCATED AT 400 WORDS)

AIDS-Related Opportunistic Infections↗
PubMed1993

[Cytokines and severe infections].

In severe infections two factors play a part: the infectious agent and the response of the host. The response of the host involves production of a large number of endogenous mediators including a number of cytokines that are currently the focus of many studies: tumor necrosis factor (TNF alpha), interleukins (IL-1 and IL-6), and interferon gamma (IGN gamma). These cytokines are part of the body's normal defense mechanisms but can have toxic effects when produced in excessive amounts. Although levels of these cytokines are often high in the blood of patients with sepsis, persistence of these elevations is the main indicator of severe infection. Experimentally, injections of TNF alpha and IL-1 reproduce the manifestations of severe sepsis. Mice that are genetically unable to produce TNF alpha are resistant to the injection of endotoxin. Severe sepsis can be prevented by pretreatment of animals with anticytokine agents (polyclonal and monoclonal antibodies and anti-receptor agents ...). Many issues remain unresolved: for instance, the experimental results obtained with an intravenous bolus of endotoxin or bacteria have not been confirmed in some animal models of subacute infection. These models may more closely resemble human infections. The interrelations between these cytokines are extremely complex. Synergistic effects do occur, but the effects of combinations of cytokines can be different from those of each cytokine given alone... It follows that therapeutic use in humans of anti-cytokine molecules is still an approach of uncertain outcome that will perhaps be clarified by ongoing multicenter clinical trials.

Animals↗
PubMed1992

Meningoencephalitis due to penicillin-resistant Streptococcus pneumoniae.

The case of a 68-year-old man suffering from pneumococcal meningoencephalitis is reported. Antibacterial susceptibility tests revealed a multiply resistant pneumococcal strain. High doses of cefotaxime were necessary to sterilize the cerebrospinal fluid despite the achievement of a satisfactory level of antibiotic in the cerebrospinal fluid with moderate dosage. In France, as well as in many countries, high doses of third-generation cephalosporins such as cefotaxime or ceftriaxone should be administered for the initial therapy of suspected pneumococcal meningitis.

Aged↗
PubMed1992

[Efficacy and tolerance of Elohes in plasma exchanges].

This study aimed to compare two plasma substitution regimens used during plasma exchanges (PE). It was a prospective cross-over randomized trial. Each patient (n = 12) had two PE at a 48 h interval. During one PE, only albumin was administered (PEA), and during the other one, equal volumes of albumin and low molecular weight hydroxyethylstarch (HES) (Elohes) were given (PEA+E). The order in which these different protocols were used was random. Plasma was separated by filtration, and the total volume extracted was one and a half the plasma volume. The parameters recorded every 15 min until 1 h after the end of PE, were heart rate, blood pressure and central venous pressure (CVP). Plasma volume, calculated from the mean body haematocrit and blood volume, was measured before and after PE. The clinical and biological tolerance of the rapid infusion of a large volume of HES was also assessed. PE characteristics were similar in both groups. For PEA and PEA+E, PE lasted 152 +/- 21 min and 154 +/- 25 min; the plasma volume extracted was 3,907 +/- 772 ml and 3,933 +/- 717 ml; the volume of plasma substitute infused was 4,097 +/- 617 ml and 3,933 +/- 717 ml, respectively. As haemodynamic and biochemical values were not significantly different in both groups, they were pooled together irrespective of the order of PE.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Immunotherapy of severe infectious states].

Although symptomatic treatments have been optimized, mortality in severe infectious conditions still exceeds 50% in many instances. Excessive activation of inflammation mediators, the endogenous relay of the initial stimulus, may account for the secondary occurrence of polyvisceral failure. This "internal" conception of severe infectious conditions opens new therapeutic possibilities including the modulation of the host's response. However, this new treatment of severe septic conditions, which complements antibiotic therapy and symptomatic measures, encounters several difficulties: a) proinflammatory mediators also have beneficial effects; b) as the mediator cascade is activated within a few hours, ordering immunity-modulating treatments early appears to be a logical step; c) monoclonal antibodies and recombining molecules are very expensive. Costs may be further increased by the probable need to use "cocktails" of antiinflammatory molecules. All these reservations show how technically blameless future clinical trials have to be. Cost efficiency and cost/benefit studies are also required. We may wonder whether society will make the financial choice to use these new treatments.

Anti-Inflammatory Agents↗
PubMed1992

[Bacteriostatic activity and killing curves of eight antibiotics against seven strains of penicillin G-resistant pneumococci].

Increasing resistance to multiple antimicrobial agents including penicillins is a current problem with Streptococcus pneumoniae. Seven cases of severe infection due to penicillin G-resistant pneumococci were seen in two teaching hospitals in Paris (France) during the first half of 1991; six of the strains were recovered from pulmonary secretions (protected brush specimens) and one from cerebrospinal fluid (CSF). The bacteriostatic activity and killing curves of eight antimicrobials against these seven strains were studied. Antimicrobial agents tested included penicillin G (PEN), amoxicillin (AMX), cefotaxime (CTX), imipenem (IPM), rifampin (RIF), vancomycin (VAN), fosfomycin (FOS), and erythromycin (ERO). MICs were determined using the agar dilution method. Killing curves were obtained using a liquid medium inoculated with 10(5) to 10(6) CFU/ml and subjected to continuous agitation; survivors were counted at baseline and after 1, 3 and 5 hours incubation. MICs of each antimicrobial (mg/l) for the seven strains were in the following ranges: PEN: 0.5-2, AMX: 0.5-2; CTX: 0.125-1; IPM: 0.03-0.25; RIF: 0.12-0.25; VAN: 0.25-1; FOS: 16; ERO: 0.06 greater than 4. Overall, bactericidal activity was greatest with vancomycin, followed by imipenem, then amoxicillin. The cefotaxime-fosfomycin combination proved synergistic and exhibited bactericidal activity (2MIC + 2MIC) for three of the seven strains. This study demonstrated the value of the cefotaxime-fosfomycin combination. Both these antimicrobials seem appropriate for the treatment of meningitis caused by penicillin G-resistant pneumococci provided their dosage is adjusted to achieve adequate drug levels in the cerebrospinal fluid.

Amoxicillin↗
PubMed1991

[Severe immunoallergic hemolytic anemia caused by a glafenine metabolite].

Three weeks after a surgical operation, a 74-year old woman was admitted to hospital for severe haemolytic anaemia. A strongly positive IgG type direct Coombs test pointed to a iatrogenic origin, but a search for anti-molecule antibodies directed against all medicines taken by the patient after surgery was negative. We extended our immunological investigations and were able to demonstrate the presence of IgG type antibodies directed against an ex vivo metabolite of glafenine.

Aged↗
PubMed1991

[Acidoketosis in a chronic alcoholic woman].

A 37-year-old chronic alcoholic female was admitted with epigastric pain, complete anorexia, vomiting and diarrhoea. She was dehydrated, and had polypnoea. Laboratory investigations revealed severe metabolic acidosis (pH 7.14) with a major anion gap (37.4 mmol.l-1), and ketone bodies in blood and urine. Blood glucose concentration was 6.1 mmol.l-1, there was no glycosuria. Rehydration (2 l.day-1 of 5% glucose) together with sodium bicarbonate (500 ml of 1.4% sodium bicarbonate over the first four hours) normalized the pH (7.37). The ketone bodies disappeared on the following day. During the acute illness, were found high blood levels of glucagon and low levels of insulin. The diagnosis of alcoholic ketoacidosis, the pathogenesis of which remains unknown, is discussed.

Acid-Base Equilibrium↗