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Biomedical subjects

G Tremblay

Publications and source records attributed to G Tremblay.

At least 55 records · Page 3Linked to original sources
PubMed1990

Airborne microbial contents in two types of swine confinement buildings in Quebec.

Airborne microorganisms were isolated with a sampler in two types of swine confinement buildings (farrowing units and fattening units). Respirable (particles less than 5 microns) and total dust fractions were obtained. Samplings were repeated every 2 weeks for a total of 6 samplings per unit between January and April. The predominant microorganisms isolated were bacteria (up to 1.25 x 10(6) CFU/m3) with an important fraction in the respirable size range (up to 0.5 x 10(6) CFU/m3). Only small quantities of gram-negative bacteria, yeasts, and molds were found. Identification of the colonies isolated revealed a great diversity of microorganisms present in the air of the different buildings. Enterobacter agglomerans, Moraxella, Acinetobacter calcoaceticus, and Pseudomonas were the most frequently identified bacteria. Scopulariopsis, Aspergillus, Penicillium, and Candida were the most numerous fungi. Faenia rectivirgula, the causative agent of farmer's lung, was not a major contaminant. The results show some differences in airborne microbial contamination between farrowing and fattening units; the distinction, however, is not clear-cut and was observed only for the total bacteria. The level of airborne microbial contamination in swine units does not significantly vary as a function of the outside temperature. Some species of bacteria and fungi isolated in this study are known to induce extrinsic allergic alveolitis. Other fungi are known to be potentially pathogenic for man. The air of swine confinement buildings is highly contaminated with bacteria, yeasts, and molds at a level up to 1200 time higher than so-called "normal air."

Air Microbiology↗
PubMed1990

Sequential bronchoalveolar lavages by endotracheal intubation in guineapigs.

We examined the feasibility of performing repeated bronchoalveolar lavage (BAL) on guineapigs. We also determined the influence of lavage volume on cell recovery in these animals, verified if the free cell populations were altered by repeated lavage, and compared the results with those obtained after euthanasia. Live animals were intubated orotracheally by direct vision laryngoscopy and lavaged, except for the last BAL which was done on isolated lungs after euthanasia. Each animal was lavaged weekly for 8 weeks: weeks 1-5 lavages were done with 5 aliquots of 2 ml of normal saline, week 6 with 3 aliquots of 1 ml, week 7 with 3 aliquots of 2 ml, and week 8 with 5 aliquots of 2 ml after euthanasia. The first 5 BAL gave similar results in volumes recovered, total number of cells, cell viability and differentials. The total cell yield of lavages 6 and 7 was less than that of the first 5 BAL and BAL 8; cell differentials with these smaller lavages were similar except for the percentage of neutrophils which was slightly higher than with the 10 ml lavage at week 3. The final lavage gave similar results as the first 5 BAL in terms of total cells recovered, cell viability, and differentials. We conclude that repeated BAL is feasible in live guineapigs, and that it gives a similar cells yield as lung lavage obtained after euthanasia.

Animals↗
PubMed1989

Transgenic mice carrying the mouse mammary tumor virus ras fusion gene: distinct effects in various tissues.

Transgenic mice carrying the v-Ha-ras oncogene under the control of the mouse mammary tumor virus long terminal repeat were produced. These mice exhibit several phenotypes: mammary tumors, bilateral hyperplasia of the harderian lacrimal gland, primary bronchio-alveolar lung adenocarcinoma, and splenomegaly. High levels of the transgene RNA were detected in mammary, harderian, and lung tumors. Accumulation of cells of the myeloid lineages was found in enlarged spleens. This phenotype may represent an indirect effect of v-Ha-ras expression on myeloid progenitors. Our data illustrate the cell-specific effects of v-Ha-ras.

Animals↗
PubMed1988

Cloning, sequencing and expression of a Bacillus bacteriolytic enzyme in Escherichia coli.

Several hundred bacterial isolates were screened for bacteriolytic activity by growing them on agar medium containing autoclaved, lyophilized Micrococcus lysodeikticus cells as the substrate. A Bacillus sp. producing the largest lytic zone was selected. A genomic bank of this selected bacterium was constructed in the multi-functional vector pTZ18R, with partial SauIIIA DNA fragments inserted at the SalI restriction site. Screening of 800 colonies of this bank for cell lysis gave 5 recombinants exhibiting lytic activity, as detected by analysis of extracts of sonicated Escherichia coli cells on denaturing polyacrylamide gels containing autoclaved, lyophilized M. lysodeikticus cells as the substrate. One clone (pBH2500), expressed in E. coli strain NM522, was found to code for a lytic enzyme corresponding, in molecular weight, to the 27 kDa Bacillus sp. hydrolase. This clone with an insertion of 2.5 kb was then subcloned as a 929 bp EcoRI-SauIIIA fragment in pTZ18R (pBH929) and showed higher cell lytic activity. A unique open reading frame for a protein of 251 amino acids, followed by a putative terminator sequence, was found after a consensus ribosome binding site. A putative leader sequence was identified in the first 37 amino acids. One truncated subclone (pBH703), corresponding to 196 out of 251 residues from the protein N-terminal end, still possessed lytic activity.

Amino Acid Sequence↗
PubMed1987

Diversity among Opine-Utilizing Bacteria: Identification of Coryneform Isolates.

Bacteria were isolated from soil and crown gall tumors by selection in minimal medium with an opine, such as succinamopine or mannopine, as the sole carbon source. The isolates were characterized for the pattern of opine utilization and identified. They were classified as mannityl opine or imino diacid utilizers and exhibited specificity of utilization similar to that described previously for Agrobacterium species. A minority of isolates were gram negative and were identified as Agrobacterium or Pseudomonas species; most were gram positive and belonged to the coryneform group. These results indicate that any specific effect of opines on the ecology of Agrobacterium tumefaciens is modulated by activities of other types of soil- and plant-associated bacteria.

Journal Article↗
PubMed1987

Muscular compensatory mechanism in the presence of a tendinitis of the supraspinatus.

The aim of this study was to assess the electromyographic (EMG) activity of the middle part of the deltoid and of the supraspinatus muscles in subjects suffering from supraspinatus tendinitis. This experimental group (N = 10) was compared to a control group (N = 10). Each subject performed three isometric contractions for each of four pre- determined levels (5, 20, 35 and 50%) of their maximal voluntary contraction (MVC) during shoulder abduction. These contractions were carried out at angles of 0 degree and 45 degrees of abduction. The EMG signals obtained for each subject were integrated and normalized in a Z score form. Trend analysis, performed on the data of each of the two groups, revealed the existence of a significant (p less than 0.001) linear relationship between the integrated EMG (IEMG) and torque levels for each muscle investigated, at both angles of abduction. Furthermore, in the control group, similar EMG amplitudes were obtained for each muscle at these two angles of abduction. However, in the experimental group, the IEMG of the deltoid muscle showed a significant decrease in activity relative to the activity of the supraspinatus at an angle of 45 degrees of abduction (ANOVA, p less than 0.05). It is suggested that this inhibition of the deltoid reflects a compensatory mechanism. The purpose of this mechanism could be to prevent the compression of the affected supraspinatus tendon between the humeral head and the acromion that could occur while abducting the arm.

Adult↗
PubMed1986

Differential long-term intrarenal and neurohormonal effects of captopril and prazosin in patients with chronic congestive heart failure: importance of initial plasma renin activity.

Fifty patients with congestive heart failure received, by infusion, 15 ml/kg body weight water load, and systemic hemodynamic, renal function, and neurohumoral parameters values were measured before, 2 days, and 1 month after randomly allocating patients to prazosin or captopril therapy. Both prazosin and captopril caused similar and persistent hemodynamic changes, but important differences existed between their renal and neurohumoral effects. After 1 month of continuous therapy, captopril increased creatinine clearance from 71 to 84 ml/min/1.73(2) (p less than .05), increased the water load excreted in 5 hr from 50% to 71% (p less than .005), and increased 5 hr sodium excreted from 6.8 to 14.7 meq (p less than .005), Captopril also caused a decrease in plasma norepinephrine from 568 to 448 pg/ml (p less than .005), in plasma epinephrine from 94 to 73 pg/ml (p less than .05), and in plasma aldosterone from 57 to 28 ng/dl (p less than .005), without changing plasma vasopressin. These beneficial effects were greater after 1 month of therapy than after 2 days. The only beneficial effect of prazosin was to increase water excretion from 49% to 59% (p less than .05). The long-term response to captopril was similar in patients with higher (greater than 2.5 ng/ml/hr) and lower renin levels. However, in patients with lower renin levels, prazosin decreased pulmonary capillary wedge pressure (24.8 to 21.8 mm Hg, p less than .05), decreased plasma arginine vasopressin (1.16 to 0.75 pg/ml, p less than .05), increased water excretion (62% to 85%, p less than .005), and decreased plasma epinephrine (81 to 46 pg/ml, p less than .05), while in patients with higher renin levels none of these beneficial effects were noted. We conclude that captopril produces long-term beneficial renal and neurohumoral effects that prazosin does not despite similar hemodynamic changes with the two drugs, that these effects are at least partially dependent on the initial neurohumoral and hemodynamic status of the patient, and that through hemodynamic improvement vasodilators may chronically interrupt vasopressin overstimulation.

Captopril↗
PubMed1985

Chickenpox with delayed contralateral hemiparesis caused by cerebral angiitis.

Chickenpox and herpes zoster ophthalmicus are caused by the same virus. Herpes zoster ophthalmicus can be followed by contralateral hemiparesis, which is thought to be caused by spread of varicella-zoster virus to blood vessels contiguous to the trigeminal nerve and its branches. We report what we believe to be the first case of a patient with chickenpox followed by hemiparesis in whom there was angiographic evidence of an associated vasculitis similar to that found with herpes zoster ophthalmicus.

Brain Ischemia↗
PubMed1985

Giant intraductal papilloma of the breast: a case report.

A case of an unusually large solitary intraductal papilloma of the breast is reported. This benign neoplasm presented as a 15-cm breast mass, enlarging over a 2-year period. The case illustrates that benign intraductal papilloma may rarely present as a large breast mass and therefore should be considered in the differential diagnosis of very large breast lesions.

Breast Neoplasms↗
PubMed1985

High-dose isosorbide dinitrate in management of angina pectoris.

The hypothesis was tested that selected patients with coronary artery disease whose rate of angina attacks do not respond to low doses of isosorbide dinitrate (ISDN) (40 mg/day) may respond to high doses (480 mg/day), tolerate them, and maintain their responsiveness over the long term. Twenty-four patients with grade 3 stable angina pectoris were given a placebo for 4 weeks and then had their ISDN dosages titrated up to 120 mg four times a day during another 6 weeks in a single-blind fashion. The 20 patients who responded to (and tolerated) a high dose of ISDN were maintained at that dose for an average of 1 year. The weekly rate of angina attacks fell by 74%, from 6.05 during placebo to 1.6 (p less than 0.01) during long-term ISDN treatment. Nitroglycerin consumption fell similarly. Patient assessment of activity level, well-being, and angina threshold improved in the majority of patients. The within-patient trend of their weekly rate of angina episodes was stable in 13 patients, downward in six, and upward in only one patient. Exercise performance evaluated by a submaximal graded multistage treadmill test showed a small but nonsignificant improvement of 1.8%. It is concluded that (1) some patients who do not respond to the antianginal action of low-dose ISDN may respond to a high dose and tolerate it, (2) this responsiveness and tolerability may last for over a year, and (3) ISDN may be clinically useful in patients with coronary disease even when exercise performance is not significantly improved.

Adult↗
PubMed1985

Autoradiographic demonstration of estrogen binding in human breast cancer after in vitro incubation.

This report describes the localization of bound radioactivity as visualized by thaw-mount autoradiography in 35 cases of human breast carcinoma after in vitro incubation with [3H]estradiol. The findings have been compared qualitatively with results of biochemical assays. Twenty-six tumors were considered to be estrogen receptor positive by autoradiographic criteria. Of these, 23 were assayed biochemically; 21 were found to be positive. Specific uptake of radioactivity was observed primarily in neoplastic epithelial cells. The grains were localized mainly over the nuclear region of putative target cells. Within nests of infiltrating carcinoma, positive cells could be identified admixed with negative cells. There were no autoradiographic criteria established for borderline cases. The remaining nine cases were considered negative. In these cases the appearance of tissue exposed only to [3H]estradiol resembled that of tissue incubated with excess unlabeled estradiol. The few grains were randomly scattered with no evidence of nuclear localization. Of these negative cases, two were positive by biochemical assay, four borderline, and three negative. It is concluded that, as assessed in this investigation, estrogen receptor-positive mammary carcinomas may be composed of target and nontarget neoplastic cells. Thaw-mount autoradiography should prove useful in the laboratory investigation of steroid hormone responsiveness of human breast carcinoma.

Adult↗
PubMed1984

Autoradiographic demonstration of 3H-estradiol incorporation in benign human mammary lesions.

This study reports the distribution of 3H-estradiol incorporation as assessed by thaw-mount autoradiography after in vitro incubation of fresh tissue obtained from a series of 17 benign human mammary lesions. In four out of nine cases of fibroadenoma examined, putative estrogen target cells were identified in ducts where the specific labeling was confined to some but not all epithelial cells. Elsewhere in these lesions, negative ducts could be found. Similarly, in three out of eight cases of fibrocystic disease specific labeling was seen over epithelial cells in some areas but not others. Histologically identifiable myoepithelial cells were negative as well as the vast majority of stromal cells.

Adenofibroma↗
PubMed1983

The localization of 3H-estradiol in estrogen receptor-positive human mammary carcinoma as visualized by thaw-mount autoradiography.

Biochemical assays of human mammary carcinomas for estrogen receptors (ER) are of proven clinical usefulness. The reliability of histochemical or immunocytochemical methods for ER localization are less well established, and less is known about the distribution of estrogen binding proteins in breast cancer. In this report we present results of a study of the uptake and retention of 3H-estradiol after in vitro incubation as visualized by thaw-mount autoradiography in five cases of biochemically estrogen receptor-positive breast cancer. These neoplasms appeared to be composed of a heterogeneous population of labeled and unlabeled tumor cells. The number of nuclear grains varied among putative target cells, and the relative percentage of labeled cells differed from area to area. Non-neoplastic mammary ductal epithelium on occasion revealed significant nuclear labeling, but stromal cells, inflammatory cells, and endothelial cells were generally negative. The possible significance of these findings is discussed.

Autoradiography↗
PubMed1983

High-dosage isosorbide dinitrate therapy for angina.

We investigated the possibility that high dosages (480 mg/d) of isosorbide dinitrate might reduce the frequency of angina attacks in selected patients who had not responded to low dosages of the drug (40 mg/d), and that the patients could tolerate the high levels of medication and maintain their responsiveness over the long term. In the single-blind phases of this trial 24 patients with grade 3 stable angina pectoris were given a placebo for 4 weeks and then increasing doses of isosorbide dinitrate for a further 6 weeks. The 19 patients who both responded to and tolerated high doses of the drug kept taking 480 mg/d for an average of 1 year. The average weekly rate of angina attacks fell by 74%, from 6.05 in the placebo phase to 1.6 during long-term active treatment (p less than 0.01). Nitroglycerin consumption decreased accordingly. The patients' assessments of their levels of activity and well-being and their angina thresholds showed improvement among most of them. The trend of angina frequency was stable in 12 cases, downward in 6 and upward in only 1 case. Exercise performance as evaluated by a graded treadmill test showed a small but nonsignificant improvement of 18%. It was concluded that some patients who do not respond to the antianginal action of low-dosage isosorbide dinitrate and cannot be given beta-blockers may respond to high dosages and tolerate them for over a year. Isosorbide dinitrate may be clinically useful in patients with coronary heart disease even though their exercise performance is not significantly improved.

Adult↗
PubMed1982

[The usefulness of an exercise test on a treadmill shortly after a myocardial infarction].

A program of reconditioning through walking was prescribed for 130 patients following an exercise test on a treadmill 3 weeks after a myocardial infarction. At 8 and at 12 weeks the patients again underwent an exercise test. The protocol is safe and permits the detection of angina, arrhythmias and dyspnea during the exercise, thus avoiding delays in treatment. The heart rate and the systolic blood pressure were measured at the end of each stage of the test and after 3 minutes of recuperation. About 75% of the patients attained the target energy output of the two submaximal tests (4 and 7 mets at 3 and 8 weeks respectively); an output of 7 mets permits a patient to resume his or her usual daily activities. The results of the tests at 3 and 12 weeks (the latter a maximal test) showed that the probability of an aerobic capacity of 7 mets or greater at 12 weeks is 86% if the 3-week test is completed. Clinical observations alone did not have the same prognostic value 3 weeks after the infarction.

Aged↗