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Biomedical subjects

J Doucet

Publications and source records attributed to J Doucet.

At least 73 records · Page 4Linked to original sources
PubMed1997

Low-molecular-weight heparin and abciximab for thrombo-occlusive saphenous vein graft disease. Report of 2 cases.

Both reoperation and alternative treatments for thrombo-occlusive disease of saphenous vein grafts have been fraught with a high rate of complications and a low rate of long-term success. We report 2 cases in which thrombo-occlusive saphenous vein graft disease was treated with the aid of abciximab during the intervention and with low-molecular-weight heparin for 7 to 12 days in an outpatient setting.

Abciximab↗
PubMed1996

Effects of angiotensin-converting enzyme and neutral endopeptidase inhibitors: influence of bradykinin.

These experiments compare the effects of a neutral endopeptidase inhibitor, retrothiorphan, 1-[(1-mercaptomethyl-2-phenyl)ethyl]amino-1-oxopropanoic acid, a converting enzyme inhibitor, enalaprilat, and the combination of the two inhibitors on changes in blood pressure and renal function induced by exogenous and endogenous bradykinin in deoxycorticosterone acetate (DOCA)-salt rats. Enalaprilat potentiated the exogenous bradykinin-induced hypotensive responses while retrothiorphan potentiated the effects on urinary cyclic-GMP (cGMP) and bradykinin. The combination potentiated the exogenous bradykinin-induced hypotensive effects and the bradykinin-induced urinary excretion of cGMP, bradykinin and prostaglandin. The bradykinin B2 receptor antagonist, Hoe 140, had no effect on the enalaprilat- and retrothiorphan-induced changes in blood pressure and renal function. In conclusion, while angiotensin-converting enzyme and neutral endopeptidase are involved in the vascular and renal catabolism of exogenous bradykinin, the effects of the peptidase inhibitors do not appear to depend on the protection of endogenous bradykinin under acute conditions in DOCA-salt rats.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Surgical advances. A comprehensive approach to surgical rejuvenation of the eyes.

Methods to rejuvenate the eye region include shortening of the forehead, raising the brow, improving the upper eyelids by excision of blepharochalasis tissue, and reducing lower eyelid fat pads by a transconjunctival approach and at the same time elevating the stretched lateral canthus by an effective canthopexy. The risks and complications of these procedures are minimal, circumscribing the shortcomings of conventional blepharoplasty.

Forehead↗
PubMed1996

Is presentation of bacteremia in the elderly the same as in younger patients?

OBJECTIVE: To compare the presentation of bacteremia in young and elderly patients. PATIENTS AND METHODS: Seventy-one elderly (mean age 80.4 years) and 34 younger inpatients (mean age 45.7 years) with bacteremia were prospectively studied. These were compared with a control group of 187 geriatric patients (mean age 81.3 years) with clinical signs of bacteremia but in whom blood cultures were negative. Bacteremia was defined as one or more positive blood cultures showing a pathogenic bacteria in patients with clinical signs of bacteremia. In all 105 patients with bacteremia, 16 common clinical or biological signs of the disease were immediately investigated after blood culture. Patients were classified into three groups: elder patients and young patients with bacteremia and elderly patients without bacteremia. RESULTS: Only three clinical findings of the 16 studied were found in at least 70% of the bacteremic elderly patients: fever, increased erythrocyte sedimentation rate, and a clinical indication of the source of infection. These three signs were found statistically more often in bacteremic elderly compared with nonbacteremic elderly patients (P < 0.01). Seven other signs (hypothermia, altered mental state, leukopenia, and lymphopenia) had a specificity above 80%. On a logistic regression analysis, four variables were significantly and independently associated with bacteremia in the elderly: rapid onset of infection (defined as a period < or = 48 hours between the earliest manifestation of bacteremia and the time of blood blood sample), fever, altered general state, and clinical indication of the source of infection. Younger infected patients had more chills, sweating, alter general state, altered mental state or lymphopenia than did the bacteremic elderly patients. Bacteremic elderly patients had statistically few symptoms than the young infected patients (P < 0.001). CONCLUSIONS: In elderly patients with early stage bacteremia, most of the signs or symptoms that are considered typical in the literature appear irregularly. None appeared pathognomonic. Elderly patients with bacteremia had fewer signs or symptoms than younger infected patients.

Aged↗
PubMed1996

DNA mesophases induced by spermidine: structural properties and biological implications.

Conditions of formation of DNA aggregates by the addition of spermidine were determined with 146 base pair DNA fragments as a function of spermidine and NaCl concentration. Two different phases of spermidine-DNA complexes are obtained: a cholesteric liquid crystalline phase with a large helical pitch, with interhelix distances ranging from 31.6 to 32.6 A, and a columnar hexagonal phase with a restricted fluidity in which DNA molecules are more closely packed (29.85 +/- 0.05 A). In both phases, the DNA molecule retains its B form. These phases are always observed in equilibrium with the dilute isotropic solution, and their phase diagram is defined for a DNA concentration of 1 mg/ml. DNA liquid crystalline phases induced by spermidine are compared with the DNA mesophases already described in concentrated solutions in the absence of spermidine. We propose that the liquid crystalline character of the spermidine DNA complexes is involved in the stimulation of the functional properties of the DNA reported in numerous experimental articles, and we discuss how the nature of the phase could regulate the degree of activity of the molecule.

Animals↗
PubMed1996

Endothelin antagonists in salt-dependent hypertension associated with renal insufficiency.

Bosentan is a nonspecific antagonist for endothelin (ET) receptors, and BQ123 is a specific inhibitor for ET-A receptors. We compared the effects of bosentan (10 mg/kg intravenously, i.v.) and BQ123 (10 mg/kg/h i.v.) on blood pressure and renal function in deoxycorticosterone acetate (DOCA)-salt rats, Dahl salt-sensitive (Dahl-S) rats, and normotensive Wistar rats. In normotensive Wistar rats, bosentan and BQ123 decreased blood pressure. Only BQ123 decreased glomerular filtration rate (GFR) and filtration fraction. These results indicate that ET-A receptors play a role in glomerular function. In DOCA-salt rats, bosentan and BQ123 caused a decrease in blood pressure to normal range and a decrease in renal vascular resistances. Bosentan decreased filtration fraction. Paradoxically, BQ123 caused a decrease in GFR. In Dahl-S rats, bosentan and BQ123 decreased blood pressure, but blood pressure did not reach normal ranges. Bosentan did not modify renal function, but BQ123 caused a decrease in the GFR and filtration fraction. Our results confirm the importance of specific and nonspecific ET antagonists in decreasing blood pressure in models of salt-dependent hypertension. However nonspecific inhibition of ET action did not improve renal function and specific inhibition of ET-A receptors by BQ123 temporarily worsened renal function.

Animals↗
PubMed1996

Drug-drug interactions related to hospital admissions in older adults: a prospective study of 1000 patients.

OBJECTIVE: To investigate the frequency, nature, and side effects of drug-drug interactions (DDI) in a group of geriatric inpatients. DESIGN: Study of drugs administered at home in the 2 weeks preceding hospitalization. SETTING: Evaluation of patients admitted to a geriatric unit from the emergency unit. PATIENTS: One thousand inpatients more than 70 years of age (83.0 +/- 7.1 years), admitted consecutively to a hospital for acute illness. MEASUREMENTS: All possible two by two combinations of drugs administered at home were considered to determine whether these associations could lead to a DDI and whether side effects resulted from these interactions. RESULTS: Five hundred thirty-eight patients were exposed to 1087 DDI. The most frequently involved drugs were cardiovascular and psychotropic medications. There were 189 side effects observed in 130 patients. The most frequent side effects were neuropsychological impairment, arterial hypotension, and acute renal failure. The number of side effects did not differ between the 66 contraindicated drug associations and the 1021 associations that only required precautionary use. CONCLUSIONS: DDI frequently lead to side effects in older adults. Classifications of DDI must be adapted to increased DDI sensitivity in this population. Nevertheless the frequency of side effects might be reduced by limiting the prescription of the most frequent and dangerous DDI.

Aged↗
PubMed1996

Differences in the signs and symptoms of hyperthyroidism in older and younger patients.

OBJECTIVES: To determine if aging modifies the clinical presentation of hyperthyroidism and the signs of thyrotoxicosis in older people. DESIGN: Prospective cohort study. SETTING: A French university hospital. SUBJECTS: Eighty-four new patients with overt hyperthyroidism confirmed chemically between January 1992 and January 1993. Controls were 68 older euthyroid patients matched to the older hyperthyroid patients. MEASUREMENTS: Comparison of 19 classical signs of hyperthyroidism between 34 older patients (> or = 70 years; mean age 80.2) and 50 younger patients (< or = 50 years; mean age 37.4). Older patients were also compared with controls (mean age 81.3). RESULTS: Three signs were found in more than 50% of older patients: tachycardia, fatigue, and weight loss. Seven signs were found significantly less frequently in older patients (P < .001): hyperactive reflexes, increased sweating, heat intolerance, tremor, nervousness, polydipsia, and increased appetite. Only anorexia (32% vs 4%) and atrial fibrillation (35% vs 2%) were more found frequently in older people (P < .001). A goiter was present in 94% of the younger and in 50% of the older patients (P < .001). The mean number of clinical signs found in the older subjects was significantly smaller than the number found in younger patients (6 vs 10.8; P < .001). Comparison with older controls showed three signs that were highly associated with thyrotoxicosis in older people: apathy (Odd ratio (OR): 14.8), tachycardia (OR: 11.2), and weight loss (OR: 8.7). CONCLUSION: This study confirms the paucity of clinical signs of hyperthyroidism in older adults. These results suggest the necessity of routine screening for thyroid disease in this age group.

Adult↗
PubMed1996

The aging eye: pathophysiology and management.

As humans go through the normal process of aging, there is drooping of many of the deep structures of the eyes. For generations, and continuing today, aesthetic plastic surgeons are removing superficial structures (i.e., skin and fat) as the primary management of drooping upper and lower eyelids. However, the dissatisfaction of patients with the results of these conventional approaches (Fig. 1) has led to further research and the development of innovative techniques that give a more youthful and harmonious appearance to the face.

Journal Article↗
PubMed1995

PCB and organochlorine pesticides in Canadian human milk--1992.

Human milk (497 samples) representing donors from across Canada were analyzed for 24 organochlorine pesticides and industrial chemicals and 40 PCB congeners. PCBs, p,p'-DDE, hexachlorobenzene (HCB), and trans nonachlor were present in all samples. Compared to earlier surveys in Canada, concentrations of most residues determined declined, and were lower than those reported recently in European countries. Although regional differences were minor, residues of PCBs, p,p'-DDE, and trans nonachlor were higher in the Ontario, Quebec, and Eastern regions, and all residues were slightly higher in the Great Lakes Basin compared to the rest of Canada. Concentrations of PCBs, DDTs, HCB, and trans nonachlor were higher in participants who consumed greater than 100 g of fish weekly.

Canada↗
PubMed1995

[Small bowel metastasis disclosing malignant melanoma].

In a 72 year-old woman with microcytic anemia, small bowel study showed tumoral lesions. Malignant melanoma was histologically proved. Clinical and radiological aspects of metastatic malignant melanoma of the small bowel are discussed and hypothesis advanced to explain absence of an identifiable primary lesion.

Aged↗
PubMed1994

Organization of stratum corneum lipids in relation to permeability: influence of sodium lauryl sulfate and preheating.

The role of the structural organization of intercorneocyte lipids in the barrier function of human stratum corneum was evaluated by treatment with heat and sodium lauryl sulfate. Measurement of transepidermal water loss in treated samples was used to quantify variations in stratum corneum permeability. Thermodynamic transition of lamellar lipids and their degree of organization were evaluated by differential scanning calorimetry and small-angle X-ray diffraction, respectively. Progressively preheating stratum corneum samples from 75 degrees C to 90 degrees C increased stratum corneum permeability to water vapor, while the fusion temperature of lamellar lipids and the intensity of the X-ray diffraction peaks of the polar lipids decreased. Sodium lauryl sulfate induced similar variations of these three parameters. These results support the hypothesis that, in addition to the chemical nature of intercorneocyte lipids, their structural arrangement and thermodynamic properties play an important role in the barrier function of the stratum corneum to water vapor.

Calorimetry, Differential Scanning↗
PubMed1994

Correlated intramolecular motions and diffuse X-ray scattering in lysozyme.

Correlated motions of protein atoms are of biological significance in processes involving ligand binding, conformational change and information transmission. X-ray scattering patterns from protein crystals contain diffuse scattering that originates from correlated displacements of atoms. Here we present experimental data on diffuse X-ray scattering from lysozyme crystals. We show that the diffuse scattering is similar in form to scattering derived from molecular dynamics simulation and normal mode analysis of the isolated protein, the normal modes giving the closest agreement with experiment.

Animals↗