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Biomedical subjects

C Girard

Publications and source records attributed to C Girard.

At least 91 records · Page 5Linked to original sources
PubMed1995

Non-neoplastic lesions in beluga whales (Delphinapterus leucas) and other marine mammals from the St Lawrence Estuary.

In a 3-year (1988-1990) pathological study, 24 carcasses of beluga whales from the St Lawrence Estuary, Québec, Canada, showed numerous severe lesions, many of which had never been reported in cetaceans. The most common lesions were found in the digestive tract (21 animals) and consisted mainly of periodontitis and of erosions and ulcers in the oesophagus and the first two gastric compartments. Pneumonia, usually of parasitic origin, was also a common finding (12 animals). The adrenal glands often contained nodules (five animals) or cysts (seven animals), and mastitis was observed in five females. Overall, the incidence of degenerative, infectious, hyperplastic or necrotic lesions, in addition to numerous neoplasms described in another paper, was considerably higher than that found in marine mammals elsewhere or in other species of marine mammal from the same waters.

Animal Diseases↗
PubMed1995

Comparison between acute hypoxia-induced and mechanically-induced pulmonary artery hypertension on the hemodynamics, myocardial contractility and regional blood flow in dogs.

Two groups of eight anesthetized dogs with pulmonary artery hypertension (PAH) were compared. PAH was induced by submitting one group (HP) to hypoxia (FiO2 range: 6-10%) and the other group (ME) to microemboli through glass microbead injection into the pulmonary circulation. Hypoxia-induced PAH was moderate (PAP: +65%; PVR: +152%) contrasting with marked PAH after microbead injection (PAP: +190%; PVR: +389%). For similar effects on left ventricular contractility (LV dP/dt max and segmental myocardial shortening), heart rate and systemic vascular resistance, left ventricular end-diastolic pressure showed significant differences between the two groups (HP group: +75%, ME group: -9%), and so did left ventricular end-diastolic length (HP: +9%, ME: -11%). Thus, contrary to the injection of microbeads, hypoxia did not give rise to any pulmonary barrier, and consequently the changes in cardiac output (HP: +19%, ME: -15%) and hepatic blood flow (HP: +383%, ME: -77%) were significantly different. Hypoxia, and not microbead injection, was responsible for systemic hypertension (MAP: +34% and -4%, respectively). The microbead model resulted in a significantly higher PVR/SVR ratio compared to the hypoxic model (HP: 0.14, ME: 0.41). Hypoxia increased left and right myocardial blood flows whereas microbead injection affected only right ventricular blood flow, leading to significantly different RV/LV endocardial perfusion ratios (HP: +10%, ME: +98%). We conclude that microbead-induced PAH is more appropriate than hypoxia-induced PAH for hemodynamic and pharmacological studies.

Acute Disease↗
PubMed1995

[Systematic transesophageal echocardiography during the postoperative first 24 hours after mitral valve replacement].

Systematic transoesophageal echocardiography after the 10th day of mitral valve replacement with a mechanical prosthesis has enable diagnosis of several abnormal conditions: thrombi, strands and paravalvular leaks. The aim of this prospective study was to determine the prevalence of these conditions by biplane transoesophageal echocardiography in the first 24 postoperative hours. Transthoracic and transoesophageal echocardiography was performed on average 12 +/- 3 hours after coming out of the surgical block in 77 consecutive patients who underwent mitral valve replacement with a mechanical prosthesis. Nine patients (11.7%) had appearances of thrombi or strands in the left atrium or auricle. These small thrombi (1 to 1.5 cm2) were not obstructive. No embolic events were observed in the first month of these patients. Spontaneous contrast was seen in the left atrium of 31 patients (40%). The factors associated with the presence of thrombus or strands were advanced age (p = 0.02), presence of spontaneous contrast (p = 0.02) and more dilated left atrium (p = NS) Paraprosthetic leaks were seen in 11 cases (14.3%). In 10 cases, the regurgitant jets were narrow at their origin with little extension into the left atrium. Only one patient had severe regurgitation associated with raised transprosthetic pressure gradients. Cases with paravalvular leaks had a lower incidence of spontaneous contrast (3.2% vs 21.7%) and no thrombosis. Transoesophageal echocardiography demonstrated spontaneous contrast, thrombi and strands in the initial hours following implantation of a mechanical mitral valve prosthesis. The prevalence of these appearances, comparable to that of the results reported with later investigations, underlines the importance of effective anticoagulation from the fist postoperative hours.

Aged↗
PubMed1995

[Palinacousis with hemianacusia caused by left temporal lesion].

Palinacousis (auditory perseveration) is reported in a 78-year-old patient with a left temporo parietal astrocytoma. The patient complained of "echoing voice" in his right ear. Palinacousis was associated with sensitive partial seizures. Neuropsychological investigations revealed hemianacusia with normal performance for phonological discrimination and verbal repetition. We suggest that these preserved abilities allowed emergence of palinacousis.

Aged↗
PubMed1995

Porcine colonic spirochetosis: a retrospective study of eleven cases.

This retrospective study of porcine colonic spirochetosis was done in order to characterize the clinical signs, the macroscopical and microscopical changes, and the bacteriological results of cases observed in Quebec. Necropsy records of all cases of colitis were reviewed. Eleven cases with filamentous bacteria colonizing the colonic epithelium were selected. This condition was only observed in weaned piglets, and was associated with mild persistent diarrhea and growth retardation. Macroscopic changes were generally limited to the presence of soft to liquid colonic contents. Adherence of filamentous helicoidal bacteria to the apical surface of the colonic epithelium and mild diffuse infiltration of the colonic lamina propria by mononuclear cells were the main histological findings. Weakly beta-hemolytic spirochetes were isolated in 6 cases. This condition seems to be underestimated for various reasons, and it is possible that some cases diagnosed as nonspecific colitis or superficial colitis, in fact, represent later stages of porcine colonic spirochetosis.

Animals↗
PubMed1994

Pathology and toxicology of beluga whales from the St. Lawrence Estuary, Quebec, Canada. Past, present and future.

An indigenous population of 450-500 beluga whales (Delphinapterus leucas) inhabiting the St. Lawrence Estuary has been exposed chronically for more than 50 years to a complex mixture of industrial pollutants including organochlorinated compounds (OC), polycyclic aromatic hydrocarbons (PAH) and heavy metals. From 1983 to 1990, we have necropsied 45 well preserved carcasses out of a total of 120 beluga whales reported dead over this period. Of these 45 animals, nine were affected by 10 malignant neoplasms. Fifteen animals (33%) were affected by pneumonia. Milk production was compromised in eight of 17 mature females (41%), by inflammatory changes (seven animals) and cancer (one animal) which affected the mammary glands. Opportunistic bacteria were found in pure culture, and/or in significant amounts in at least two organs in 20 belugas (44%). The concentrations of both total PCBs and highly chlorinated PCB congeners were much higher in St. Lawrence animals than in Arctic beluga whales. OC-induced immunosuppression has been repeatedly demonstrated in a wide variety of animal species. Therefore, it is probable that the immune functions of St. Lawrence beluga whales are impaired. Benzo[a]pyrene adducts were detected in 10 of the 11 St. Lawrence beluga whales of which tissues (six livers, 10/11 brains) were analyzed by a method based on HPLC. No such adducts were found in four Arctic animals. Since benzo[alpha]pyrene is one of the most potent chemical carcinogens known to man, these compounds might be responsible for some of the cancers observed in that population. Overall, our findings contrast vividly with those of others who found that cancers are exceedingly rare in free-ranging odontocete populations and that the major causes for mortalities in these populations are bacteria, parasites, and trauma.

Animals↗
PubMed1994

Pathogenicity of porcine respiratory coronavirus isolated in Québec.

Porcine respiratory coronavirus (PRCV) is present in many countries, including Canada, but controversy still exists concerning its pathogenicity. Eight-week-old piglets were inoculated intratracheally with a Quebec PRCV isolate (1Q90). Two contact piglets were kept with the inoculated animals. Three animals served as control. Polypnea and dyspnea were the main clinical signs observed. Diffuse bronchioloalveolar damage occurred 24 hours postinoculation. Changes compatible with bronchointerstitial pneumonia were present six days postinoculation. The inoculated virus was recovered from the respiratory tract and mesenteric lymph nodes, but not from the digestive tract, of the inoculated as well as the contact piglets. No virus was isolated from the control piglets. The development of clinical signs and histopathological changes in inoculated as well as in contact piglets and the reisolation of the inoculated virus demonstrated that PRCV can be an important respiratory pathogen.

Animals↗