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Biomedical subjects

G Bouchard

Publications and source records attributed to G Bouchard.

At least 37 records · Page 2Linked to original sources

[Agrarian overpopulation and household structure in Saguenay (1881-1931)].

"Our paper investigates the effect of land shortage in the Saguenay region [of Quebec, Canada,] upon the household structures, more precisely on the frequency of a) complex structures, b) celibacy, c) cohabitation with strangers (non-relatives). The data come from 28 parish censuses of the period 1881-1931. For each of these three indicators, findings show that the saturation of arable land did not entail significant changes." (SUMMARY IN ENG)

Agriculture↗

Decreased biliary glutathione content is responsible for the decline in bile salt-independent flow induced by ethinyl estradiol in rats.

Glutathione appears to be a major osmotic factor in the generation of bile salt-independent flow (BSIF). This study was designed to investigate its importance in the pathology of 17-alpha-ethinyl estradiol (EE)-induced cholestasis. Five-day EE treatment at the dose level of 5 mg/kg/day significantly decreased bile flow (57% of controls) and biliary glutathione secretion. Evaluation of the contribution of bile salt dependent flow (BSDF), glutathione dependent flow (GSDF) and the bile flow generated independently of both bile salts and glutathione (BS-GSIF) revealed that EE decreased all portions of the flow (63, 44 and 52% of control values, respectively). At 4 and 20 h after a single administration of the same EE dose, a significant diminution of bile flow was noted (decreases of 17 and 29%, respectively) in association with a significant fall in biliary glutathione content. Under these conditions, BSDF and BS-GSIF were not modified (98 and 112% of control BSDF values, respectively; 96 and 99% of control BS-GSIF values, respectively) while GSDF was decreased markedly, representing 65 and 50% of control values. Biliary glutathione secretion was diminished without modification of liver and blood glutathione concentration or redox status following single EE dose whereas, after 5 days of EE treatment, a significant increase in liver glutathione was observed, suggesting that EE may interfere with the glutathione secretory process. This study demonstrates that EE rapidly alters biliary glutathione content, leading to a marked decline in GSDF. This reduction may explain the decrease in BSIF produced by EE at the outset of cholestasis.

Analysis of Variance↗

Moderate long-term physical activity improves the age-related decline in bile formation and bile salt secretion in rats.

This study examined the effect of moderate long-term exercise, begun soon after weaning, on the age-related decline in bile formation and the secretory rate maximum (SRm) of taurocholate (TC), the major bile salt (BS) in rats. Eight-month-old sedentary (S) female Sprague-Dawley rats showed a significant decrease in basal and TC-stimulated bile formation when compared with 2.5-month-old S controls. As in younger rats, decreased biliary phospholipid (PL) output was associated with the TC SRm, but this change appeared much more rapidly in S animals, which also exhibited significant increased plasma lipids and higher TC concentrations in plasma and liver at the end of the TC infusion. Exercise significantly improved bile flow (BF), including the bile salt-dependent and -independent fractions under basal and TC-stimulated conditions in 8 month-old rats. Although all the biliary parameters evaluated were improved, maximal BF and PL secretion values were affected the most and were virtually not different from those obtained in younger S animals. Exercise also significantly lowered the age-related elevation of plasma PL. Thus, moderate long-term exercise exerts a beneficial effect on hepatobiliary function and the BS SRm, an effect that may be attributed in part to increased availability of a biliary PL pool previously implicated in regulation of the BS SRm.

Age Factors↗

Radiographic features of cauda equina syndrome complicating ankylosing spondylitis.

Cauda equina syndrome is an uncommon complication of ankylosing spondylitis. The characteristics of this disease, as shown by plain radiography, computed tomography and magnetic resonance imaging (MRI) in a 56-year-old man, are described. The MRI features are pathognomonic, allowing accurate noninvasive diagnosis of the disorder.

Cauda Equina↗

Magnetic resonance imaging in moyamoya disease.

The authors describe the characteristic magnetic resonance imaging (MRI) findings of moyamoya disease in a 51-year-old woman; the disease was confirmed by angiography. MRI demonstrated well the occlusions and collateral vessels that typically occur secondary to this rare disease. Although hemorrhagic complications often result in a poor prognosis for patients with moyamoya disease, the patient described here recovered.

Angiography↗

Influence of oral treatment with ursodeoxycholic and tauroursodeoxycholic acids on estrogen-induced cholestasis in rats: effects on bile formation and liver plasma membranes.

In this study, we examined whether ursodeoxycholic acid (UDC) and its taurine conjugate, tauroursodeoxycholic acid (TUDC), given per os, can prevent the cholestasis induced in rats by 17-alpha-ethynyl estradiol (EE) and whether this protection is mediated by choleretic activity or altered plasma membrane composition. EE (5 mg/kg body weight/day for 5 days) markedly reduced bile flow and bile salt secretion without significantly affecting plasma membrane composition and function. Treatment with UDC or TUDC (100, 150 or 200 (TUDC only) mumol/100 g body weight/day for 5 days) did not significantly modify bile flow, but the bile salt secretion rate increased in a dose-dependent manner. UDC was the main biliary bile acid secreted in groups given higher doses of UDC or TUDC. At these dose levels, bile acid treatment did not affect plasma membrane fluidity as assessed by fluorescence anisotropy, the cholesterol/phospholipid molar ratio as well as Na+K(+)- and Mg(++)-ATPase activities. The highest dose of UDC and TUDC prevented the reduction of both bile flow and bile salt secretion induced by EE, re-establishing these parameters to the values of the corresponding control for the UDC group. In conclusion, UDC and TUDC, given per os, improve EE-induced cholestasis, an effect that cannot be attributed to choleretic activity or altered plasma membrane composition.

Administration, Oral↗

Thoracic splenosis after blunt trauma: frequency and imaging findings.

OBJECTIVE: Thoracic splenosis is an uncommon sequela of simultaneous splenic and diaphragmatic injury. The aim of this prospective study was to evaluate the prevalence of thoracic splenosis in 17 subjects who had sustained splenic and diaphragmatic injury and to describe the CT and MR features of thoracic splenosis. SUBJECTS AND METHODS: All patients had 99mTc-RBC scintigraphy. Subjects with radionuclide uptake in the thorax were further examined with radiography, CT, and MR imaging of the chest. RESULTS: Three subjects (18%) had evidence of ectopic splenic activity in the left side of the thorax. The CT features consisted of one pleural nodule and two pleural masses. The MR appearance of the ectopic splenic tissue was similar to that of normal spleen. CONCLUSION: Thoracic splenosis occurs with moderate frequency after combined splenic and diaphragmatic injury. The CT appearance is that of pleural masses or nodules. The MR appearance is relatively similar to that of normal spleen.

Adult↗

Primary pulmonary hypertension associated with HIV infection.

A Haitian woman with the human immunodeficiency virus (HIV) presented with dyspnea, cough, fatigue and lower abdominal pain of recent onset. Clinical, radiologic and hemodynamic investigations demonstrated pulmonary hypertension. The patient died a few days later. The pathological findings were compatible with primary pulmonary hypertension. This case is similar to others that have been reported and indicates a possible link between HIV infection and rapidly progressive primary pulmonary hypertension.

Acquired Immunodeficiency Syndrome↗

Ultrasonographic features of abdominal ectopic splenic tissue.

Ectopic splenic tissue may be congenital (an accessory spleen) or a result of traumatic autotransplantation (splenosis). The purpose of this study was to identify the features of ectopic splenic tissue in ultrasonography (US) scans. Selective spleen scintigraphy (with heat-denatured erythrocytes labelled with technetium 99m) was performed on 33 patients who had undergone splenectomy after trauma; the 25 (76%) for whom the results were positive subsequently underwent US. Of the 25 patients, 23 (92%) had one to five foci of ectopic splenic tissue; 62 of the 68 foci (91%) were in the left upper quadrant. US identified splenic tissue in 17 of the 25 patients (68%). All 44 foci visible with US were hypoechoic, and 33 of them (75%) exhibited acoustic enhancement or an incomplete hyperechoic rim or both. Nineteen of the foci revealed by US (43%) were smaller than 1 cm2. No criteria were found to permit differentiation of accessory spleens from splenosis. In three of every four patients who undergo splenectomy after trauma, ectopic splenic tissue eventually develops. Radiologists should be aware of this condition to avoid incorrectly diagnosing this ectopic tissue as metastasis, adenopathy or another solid tumour. US, in combination with selective spleen scintigraphy, permits a specific diagnosis without invasive procedures.

Abdominal Neoplasms↗

Multilocus markers for mouse genome analysis: PCR amplification based on single primers of arbitrary nucleotide sequence.

Polymerase chain reaction (PCR) based on single primers of arbitrary nucleotide sequence provides a powerful marker system for genome analysis because each primer amplifies multiple products, and cloning, sequencing, and hybridization are not required. We have evaluated this typing system for the mouse by identifying optimal PCR conditions; characterizing effects of GC content, primer length, and multiplexed primers; demonstrating considerable variation among a panel of inbred strains; and establishing linkage for several products. Mg2+, primer, template, and annealing conditions were identified that optimized the number and resolution of amplified products. Primers with 40% GC content failed to amplify products readily, primers with 50% GC content resulted in reasonable amplification, and primers with 60% GC content gave the largest number of well-resolved products. Longer primers did not necessarily amplify more products than shorter primers of the same proportional GC content. Multiplexed primers yielded more products than either primer alone and usually revealed novel variants. A strain survey showed that most strains could be readily distinguished with a modest number of primers. Finally, linkage for seven products was established on five chromosomes. These characteristics establish single primer PCR as a powerful method for mouse genome analysis.

Animals↗

Absorption of an alternate source of immunoglobulin in pups.

Newborn pups from 4 large litters were alloted to 6 groups to determine effect of time and route of administration on absorption of an alternate source of immunoglobulin. Selective absorption of specific classes of immunoglobulins was also investigated. The alternate source of immunoglobulin consisted of pooled serum that was administered either PO or SC. Control groups were either left with the dam (group C1) or fed milk replacer (group C2). Blood samples were collected from pups at birth and 24 hours. Immunoglobulin (IgA, IgG, IgM) concentrations were determined by use of radial immunodiffusion on samples of pooled serum, colostrum, and pups' serum (birth and 24 hours). Serum IgA concentration was less than the sensitivity of the procedure and was not included in the statistical analysis. Pups fed 8 ml of pooled serum at birth and 12 hours later (group T1) absorbed more (P less than 0.05) IgG and IgM than did group-C2 pups, but less (P less than 0.05) than did group-C1 pups. Pups fed 8 ml of pooled serum at 12 hours only had significant (P less than 0.05) increase of IgG concentration, but no absorption of IgM (P greater than 0.05) at 24 hours, compared with control pups (group C2). Pups administered 8 ml of pooled serum SC at birth (group SC1) had similar (P greater than 0.05) absorption of IgG and higher (P less than 0.05) absorption of IgM than did pups of group T1.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗

Polypoid cystitis, pyelonephritis, and obstructive uropathy in a cow.

Polypoid cystitis, pyelonephritis, and obstructive uropathy was found in a cow with hematuria, dysuria, and colic. The cow was treated with penicillin, multiple B vitamin supplementation, and isotonic sodium chloride. Polypoid cystitis, diagnosed in this cow by use of endoscopic examination, is a common response to chronic inflammation of the bladder and can lead to obstructive uropathy. Although endoscopic confirmation of this diagnosis may not always be feasible, recognition of corresponding clinical signs can allow timely, appropriate treatment.

Animals↗

[Images of Quebec's population and society: the learning of diversity].

"Recent studies in social sciences and human genetics have led to the conclusion that the traditional image of [a] highly homogeneous Quebec society needs to be substantially retouched. After a brief presentation of the traditional homogeneity discourse, the author discusses some significant examples of heterogeneity, and suggests some of the revisions these imply." (SUMMARY IN ENG AND SPA)

Americas↗

Fertility in couples heterozygous for the tyrosinemia gene in Saguenay Lac-St-Jean.

A case-control study of 84 couples from Saguenay-Lac-St-Jean, jointly heterozygous for the tyrosinemia gene, was done to determine whether the birth of an homozygous child affected their fertility rates. The mean number of children born to tyrosinemia and control couples between 1940 and 1986 was not different (p greater than 0.05). The knowledge that tyrosinemia was an autosomal recessive disorder, with risk of recurrence in these families, did not appear to modify reproductive behaviour. Fertility fell significantly in both the tyrosinemia and control families in the period of observation. This change reflects the decline in fertility of French Canadians in general during this period.

Amino Acid Metabolism, Inborn Errors↗