Search PubMed⌕ Search

Biomedical subjects

M Pellerin

Publications and source records attributed to M Pellerin.

At least 73 records · Page 4Linked to original sources
PubMed1994

Current status of valvular surgery.

Surgical treatment of valvular heart disease is a field of constant clinical and experimental research. Recently, much attention has been devoted to the improvement of valve repair techniques. The physiopathology of the left ventricular outflow tract obstruction following mitral valve repair has become better understood. Surgical techniques to correct this infrequent complication have been developed. Conservative valvular surgery or homograft use are among the surgical treatments for infective endocarditis; innovative experimental and clinical studies on mitral and tricuspid homografts have provided interesting results. New biological valves have come into use; intraoperative creation of a cardiac bioprosthesis using glutaraldehyde-treated autologous pericardium is an attractive surgical innovation. Stentless bioprostheses are also under investigation, to evaluate their hemodynamic and clinical characteristics. The biology of bioprosthesis deterioration progresses at the cellular level, with the implication of phagocytosis as a contributing factor.

Animals↗
PubMed1993

Effects of pressure and duration of hyperkalemic infusions on endothelial function.

Infusions of crystalloid hyperkalemic cardioplegic solutions (CHCSs) are known to impair endothelium-dependent coronary relaxation. This impairment might also be influenced by high perfusion pressure and duration of CHCS infusion. To verify this hypothesis, we designed experiments to study the influence of pressure and duration of CHCS infusion as modulating factors in CHCS-related endothelial impairment. Isolated hearts of Sprague-Dawley rats were studied in a Langendorff apparatus for coronary endothelial function. Hearts (n = 6) were exposed to four different CHCSs containing 12, 24, 40, or 100 mmol/L of potassium chloride (KCl). Endothelial and smooth muscle functions were respectively tested by infusion of 5-hydroxytryptamine (1 x 10(-6) mol/L) and sodium nitroprusside (1 x 10(-5) mol/L) before and after CHCS perfusion. In group I (n = 24), 37 degrees C CHCSs were perfused at 80 cm H2O of pressure for 30 minutes. In group II (n = 24), the same CHCSs were perfused at 160 cm H2O for 30 minutes. In group III (n = 18), CHCSs containing 24, 40, and 100 mmol/L of KCl were infused at 160 cm H2O for 10 minutes. In all groups, response to sodium nitroprusside was unaltered by CHCS infusion, indicating that smooth muscle function was preserved. However, in group II, 5-hydroxytryptamine-induced vasodilation was significantly impaired in hearts perfused with CHCS containing 24 mmol/L of KCl or more, suggesting endothelial damage. This study demonstrates that, in addition to KCl concentration, pressure and duration of infusion are two major determinants in CHCS-mediated endothelial damage.

Animals↗
PubMed1993

Effects of University of Wisconsin solution on endothelium-dependent coronary artery relaxation in the rat.

University of Wisconsin (UW) solution has been reported to enhance myocardial preservation in heart transplantation. To evaluate the effects of UW solution on coronary artery endothelial function, we designed experiments to compare UW solution with a standard crystalloid hyperkalemic cardioplegic solution (CHCS). Isolated rat hearts were studied in a modified Langendorff apparatus for coronary endothelial function. Groups 1 and 2 were perfused with 4 degrees C CHCS (24 mmol/L of KCl) and UW solution, respectively, for 10 minutes at a pressure of 80 cm H2O, whereas group 3 underwent warm ischemia for 10 minutes. Groups 4 and 5 were perfused with and stored for 4 hours in cold (4 degrees C) CHCS and UW solution, respectively. Group 6 underwent 4 hours of topical cooling (4 degrees C) without any cardioplegic perfusion. All groups had 6 hearts each. Endothelium-dependent relaxation and endothelium-independent relaxation of the coronary arteries were tested by infusing 5-hydroxytryptamine (5HT) (10(-6) mol/L) and sodium nitroprusside (10(-5) mol/L), respectively, before and after perfusion with and storage in one of the two cardioplegic solutions. The coronary vasodilatation induced by 5HT and sodium nitroprusside was not altered in hearts perfused with (group 1) or perfused with and stored in CHCS (group 4). Coronary flow increase after 5HT infusion was significantly decreased in hearts perfused with (group 2) (before, 35% +/- 10%; after, 13% +/- 10%; p < 0.01) or perfused with and stored in UW solution (group 5) (before, 34% +/- 5%; after, -5% +/- 12%), indicating severe endothelial dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1993

[Surgical treatment of pneumothorax in AIDS patients].

A retrospective review of the charts of 26 patients with the acquired immunodeficiency syndrome (AIDS) treated at the Hotel-Dieu de Montréal was performed. Patients presented a total of 37 pneumothoraces. Eleven cases were recurrent. Bilateral pneumothoraces were documented in three patients, most of them (17) were severe (> 75%). Pneumocystis carinii pneumonia was the most frequently associated pathology. The initial treatment consisted in chest tube drainage. A definitive treatment was indicated in 7 patients with prolonged air leaks (> 10 days) or without lung expansion. Two median sternotomies with bilateral pleurectomies, bullae plication, and talcage were done, and 5 unilateral thoracotomies with pleurectomies and bullae plications were completed. The post-operative survival was variable and related to diseases associated with the syndrome. AIDS related pneumothoraces is a morbid condition which should be treated on an individual basis.

AIDS-Related Opportunistic Infections↗
PubMed1990

Effects of daptomycin and vancomycin on tobramycin nephrotoxicity in rats.

Daptomycin is a new biosynthetic antibiotic which belongs to a new class of drugs known as lipopeptides. The objective of this study was to evaluate the effects of daptomycin and vancomycin on tobramycin-induced nephrotoxicity. Female Sprague-Dawley rats were treated during 4 and 10 days with either saline (NaCl, 0.9%) or tobramycin at doses of 4 and 40 mg/kg per day (given every 12 h [q12h] intraperitoneally). Each treatment was combined with saline, daptomycin at a dose of 20 mg/kg per day (given q12h subcutaneously), and ancomycin at a dose of 50 mg/kg per day (given q12h subcutaneously). Daptomycin and vancomycin had no effect on the intracortical accumulation of tobramycin. Daptomycin did not accumulate in renal tissue even after 10 days of treatment. Tobramycin given at a dose of 40 mg/kg per day during 10 days induced a significant inhibition of sphingomyelinase activity in the renal cortex (P less than 0.01) and increased cellular regeneration (P less than 0.01), as measured by the incorporation of [3H]thymidine into DNA of the renal cortex. These changes were minimal when daptomycin was combined with tobramycin. Histologically, signs of tobramycin toxicity were also less severe in the presence of daptomycin. The intracortical accumulation of vancomycin was not modified by tobramycin. The sphingomyelinase activity was significantly more inhibited (P less than 0.01) when vancomycin was associated with tobramycin (4 and 40 mg/kg) without affecting the rate of [3H]thymidine incorporation into DNA. Histologically, signs of tobramycin toxicity were not affected by vancomuycin, but the cellular vacuolizations which were also observed in vancomycin-treated animals were still present in the proximal tubular cells of animals that were treated with the combination vancomycin-tobramycin. This study strongly suggests that daptomycin protects animals from tobramycin-induced nephrotoxicity but that vancomycin may enhance the effect of tobramycin. We conclude that daptomycin is safe and protects kidney cells from tobramycin-induced nephrotoxicity.

Animals↗
PubMed1990

Effect of E. coli pyelonephritis on the intracortical accumulation kinetics of gentamicin and netilmicin in rats.

The role of serum levels on the intrarenal accumulation kinetics of gentamicin and netilmicin in normal and infected kidneys was evaluated in a short-term infusion model in conscious rats. Female Sprague-Dawley rats were infused over a period of 6 h with gentamicin and netilmicin achieving individual steady-state serum levels ranging from 0.5 to 120 micrograms/ml. The model of pyelonephritis used resulted in severe left pyelonephritis and mild right pyelonephritis. Only the right infected kidneys were studied. Gentamicin and netilmicin cortical concentrations were analysed as a function of serum levels by linear (least-squares regression analysis) and non-linear regression. For the non-linear regression analysis, the Michaelis-Menten kinetic was the best fitting curve. Steady-state elevation of serum concentrations of gentamicin and netilmicin was associated with a non-linear increase of cortical concentrations in normal kidneys, suggesting a saturable process. By contrast, in the mildly-infected right kidneys, the steady-state elevation of serum concentrations of gentamicin was associated with a linear increase of cortical concentrations while the accumulation kinetic of netilmicin showed a saturable process. At lower serum levels (therapeutic range, from 0.5 to 15 micrograms/ml) both gentamicin and netilmicin showed a first order kinetics of accumulation and netilmicin accumulated less than gentamicin in normal kidneys (p = 0.0004). By contrast, the uptake of netilmicin was higher in the right infected kidneys, as compared to the uptake of netilmicin in the normal kidneys, (p = 0.00005), and as compared to gentamicin in the respective kidneys. We conclude that renal infection modifies the intrarenal accumulation of aminoglycosides.

Animals↗
PubMed1987

[Chronic refractory pain in cancer patients. Value of the spinal injection of lysine acetylsalicylate. 60 cases].

Several animal studies have demonstrated that pain is modulated by spinal mechanisms involving prostaglandins and that acetylsalicylic acid (ASA) administered intrathecally has an analgesic effect. We report our experience of this treatment in 60 patients with proven and advanced cancer. An isobaric solution of lysine acetylsalicylate was administered by lumbar puncture in doses ranging from 120 to 720 mg of ASA. The results were evaluated using the habitual criteria: scoring system, behaviour, consumption of analgesic drugs. In this trial the method proved astonishingly effective (78% of the cases). Analgesia was strong, almost immediate and without influence on motricity. No thermic or neurovegetative changes were noted. The effect of one injection lasted from 3 weeks to 1 month on average; it was reproduced and often more prolonged after a repeat injection. Pain associated with bone metastases seems to constitute the best indication, notably in breast and lung cancer and in myeloma. Visceral (pancreas) or neural pain requires higher doses to respond. Failures (22%) were due to such factors as insufficient dosage at the very beginning of our experience or severe depressive syndrome. The perineal and sphincteral pain of rectal cancer often resists treatment. This simple, inexpensive and very effective method with no other complication than a frequent tendency to fatigue should rank among other analgesic measures in cancer. The lack of respiratory depression is a major advantage over catheter spinal opiate analgesia. We consider that its main indications are pain associated with osteolytic metastases of adenocarcinomas, and myelomas. Owing to the absence of formal toxicological data, its use must be limited to cancer pain and to patients with a life expectancy of less than 2 years.

Adult↗
PubMed1986

[Clonidine and treatment of arterial hypertension in the pregnant woman].

From the results of a non-controlled trial about the successful use of clonidine in 14 hypertensive pregnant women on and on the basis of a bibliographical analysis, the investigators studied efficacy and safety of this central antihypertensive drug. This risk-improvement study reveals that clonidine can be prescribed for the treatment for hypertension during pregnancy.

Adult↗
PubMed1985

Serum bactericidal activity of ceftazidime increased by netilmicin.

Cephalosporins are often used in combination with aminoglycoside antibiotics in the treatment of gram-negative infections. Although ceftazidime possesses activity against gram-negative bacteria, especially against Pseudomonas, combined use with aminoglycosides is useful. In this study, 12 healthy volunteers (6 men, 6 women; mean age 21.5 yr) received a single dose of ceftazidime 1 g iv and one week later ceftazidime 1 g iv with netilmicin 100 mg iv. Both antibiotics were infused over five minutes. Concentrations of ceftazidime were determined by high performance liquid chromatography. Serum bactericidal activity (SBA) was evaluated against seven microorganisms isolated from clinical specimens. The mean peak serum level of ceftazidime was 113.4 micrograms/ml. At eight hours, we observed a concentration of 2.6 micrograms/ml. The total clearance was 126 ml/min, while the renal clearance was 100 ml/min. Ceftazidime exhibited a half-life of 1.9 hours. Up to ten hours, the SBA of ceftazidime against Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, and Salmonella typhi was greater than 1:8 in more than 90 percent of samples. At one hour, ceftazidime exhibited a SBA of 1:4 for Staphylococcus aureus, and 1:16 for Pseudomonas aeruginosa. With the addition of netilmicin, median SBA against Staph. aureus and P. aeruginosa were 1:32 and 1:64, respectively, at one hour. Netilmicin enhanced the SBA of ceftazidime. The combination was not effective against Streptococcus faecalis.

Adult↗
PubMed1984

[Postoperative pernicious malarial attack in a subject, a native of an endemic zone].

The case of an Angolan woman who underwent, in her country, an hysterectomy requiring the transfusion of two whole blood units is reported. In the immediate postoperative period, acute renal failure with anuria set in, justifying the patient's transfer to an intensive care unit in France. Upon admission, she had a thick blood film and serology work-up for Plasmodium falciparum, both of which were negative. On the 20th day, the patient presented a pernicious malarial crisis with a concurrent rise in IgG and IgM titres, indicating recent contamination. The mode of infection is discussed: contaminating anopheline bites associated with the interruption of chemoprophylaxis rigorously followed up till then; post transfusion malaria, almost unavoidable in an endemic country; accidental inoculation by Plasmodium falciparum of the dialysis equipment. Finally, the possibility of pernicious malaria aggravating the initial acute renal failure and hypocalcaemia is also discussed.

Acute Kidney Injury↗
PubMed1983

[Voluntary poisoning by intravenous injection of caustic soda].

A voluntary intoxication by injection in the left basilic vein of 10 ml of concentrated caustic soda is reported. The main effects were, besides local necrosis, haemolysis, acute renal failure with initial anuresis, intravascular coagulation and cyanosis with a normal Pao2 due to methaemalbuminaemia. This was confirmed by using the usual spectrophotometric methods as well as electrophoretic methods.

Acute Kidney Injury↗
PubMed1981

[Acute respiratory distress syndrome of tuberculous origin in an intensive care unit. Clinical presentation and course (author's transl)].

The authors have observed 6 cases of acute respiratory distress syndrome (ARDS) of tuberculous origin. The condition presented as pulmonary oedema in 4 cases and as extensive bilateral pneumonia in 2. Pulmonary oedema was treated by artificial ventilation with intermittent positive pressure in 2 patients who died, and by continuous positive airway pressure in 2 patients who survived. The 2 patients with pneumonia survived without respiratory assistance. In these patients with atypical symptoms, early diagnosis (which may involve liver and bone marrow biopsies) and immediate therapeutic measures are life-saving. The diagnosis of tuberculosis should be systematically considered in adult ARDS, especially i patients with pulmonary oedema of unknown origin.

Acute Disease↗