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Biomedical subjects

A Girard

Publications and source records attributed to A Girard.

At least 145 records · Page 8Linked to original sources
PubMed1967

Studies on bluetongue. 3. Comparison of two complement-fixation methods.

The complement-fixation test used at Onderstepoort was compared with the method used at A.D.R.I. on infected calf and sheep sera. In the first method, the tests are incubated at 37 degrees C for 90 minutes and the test sera are inactivated at 53 degrees C; whereas in the A.D.R.I. method, the test sera are inactivated at 60 degrees C for 30 minutes, incubation is at 9 degrees C for 18 hours, and guinea-pig complement is supplemented with 5 per cent fresh, non-inactivated, normal calf serum. Serial serum samples from one of six experimentally infected calves were negative in the Onderstepoort test, three calves gave only trace reactions and two showed maximum titres of 1:10 whereas all six had maximum serum titres of 1:10 to 1:80 in the A.D.R.I. test. A good correlation was obtained, however, between the results of the two methods with the sera of experimentally inoculated sheep although titres 3 to 8 times higher were obtained with the A.D.R.I.'s test. Post inoculation bleedings from each sheep reacted in both tests.

Animals↗
PubMed1967

Studies on bluetongue. IV. Studies of three strains in primary bovine foetal kidney cell cultures.

Three different strains of bluetongue virus were adapted to grow in primary bovine foetal kidney cell cultures. The cytopathic effects observed from the three strains were similar, and were characterized by shrinkage of cells and increased granularity. The specificity of the changes was confirmed by the fluorescent antibody technique. No significant immunological cross-reaction was detected by serum-virus neutralization tests from the strains studied.

Culture Techniques↗
PubMed1967

Studies on bluetongue. V. Detection of the virus in infected materials by immunofluorescence.

The fluorescent-antibody technique was employed for the detection of bluetongue virus in bovine foetal kidney cell cultures inoculated with tissues and blood from experimentally infected animals. In the first series, a total number of 79 inoculated suckling-mouse brains were examined, 36 as frozen sections alone and 43 as impression slides in conjunction with tissue culture inoculation of the same material. With the combined tissue culture immunofluorescent methods, 36 suspicious were detected by impression smears and 37 positives by the tissue culture out of 43 brains examined. Twenty-two were suspicious out of the 36 examined as frozen sections. Results obtained with the second series, using sheep tissues, showed that the combined tissue culture-fluorescent antibody method was satisfactory for demonstrating the virus in blood of infected animals 1 to 9 days postinfection, and in some organs after death. No false positive reactions were obtained.

Animals↗
PubMed1967

Studies on bluetongue. VI. Animal transmission studies.

The Cyprus strain of bluetongue virus was successfully transmitted through six passages and the Station strain through one passage in calves. Although the animals developed no visible evidence of infection, viremia as shown by both passage and fluorescent antibody examination of infected foetal bovine kidney culture, and by serological conversion was nevertheless demonstrated. No enhancement of virulence for calves or sheep was shown following bovine passage. A ewe inoculated in late pregnancy with blood drawn from a calf 59 days after its infection, gave birth to a lamb from whose blood the virus was isolated. Significant complement-fixation titres persisted for at least 200 days.

Animals↗
PubMed1965

Hog cholera IV. Detection of the virus in tissue culture preparations by the fluorescent antibody technique.

The fluorescent-antibody technique was employed for detection of hog cholera virus in tissue cultures inoculated with spleens of infected animals. As controls, cultures were also inoculated with material from normal swine and from those infected with other agents. In the first series 71 of 73 infected spleens, or 97 per cent, were detected. There were no false positive reactions among the controls. Results obtained with the second series of pigs showed that spleens collected during advanced stages of the disease were more satisfactory specimens than those collected earlier during the high temperature phase of infection. Findings with the third series of older swine indicated that their spleens were less satisfactory as a source of virus than those from young pigs. Tissues from freshly killed animals provided better specimen material than those from animals which had died.

Animals↗
PubMedDate not supplied

Impact of local radiation in the management of salivary gland carcinomas.

Seventy patients with salivary gland carcinoma (63% major gland and 37% minor gland) are reviewed. Histologies included adenoid cystic (54%), mucoepidermoid (16%), and adenocarcinoma (14%). Patients were analyzed according to extent of surgery and whether or not adjuvant postoperative radiotherapy was given. There is no difference in survival in patients who had complete excision of gross tumor with or without adjuvant radiotherapy. Patients who did not undergo radiotherapy had a 62% actuarial risk of locoregional failure at 5 years, with a 20% risk in the adjuvantly irradiated group (P less than 0.001). A failure analysis demonstrates that among the 44% of patients with recurrence 71% (22/31) failed locoregionally and 69% (21/31) had distant metastases. Twenty-seven percent (19/70) died of disease, with 31% (6/19) dying of locoregional disease and 26% (5/19) of distant disease. Implications for management are discussed.

Adolescent↗
PubMedDate not supplied

Comparison of the reaction time, the Berg Scale and the ABC in non-fallers and fallers.

Postural sway, reaction time, the Berg Scale and the Activities-specific Balance Confidence Scale (ABC) were administered to 80 elderly subjects (40 fallers and 40 healthy non-fallers) in order to determine reliable predictor for those at risk of falling. Non-fallers showed significantly faster reaction times when compared with fallers experimental group. Postural sway results show a higher oscillation displacement in the Y axis (lateral) than the X axis (anterior-posterior) and that fallers oscillate at a higher frequency than non-fallers. All variables were submitted to a multiple regression analysis. Only three of the four variables were found to be significant predictors of fall status. The variables in order of their inclusion are reaction time, Total Berg Balance Score and mean ABC. It was further determined that reaction time was indeed the best predictor of fall status in the present study.

Journal Article↗
PubMedDate not supplied

Tuning non-linear adaptive compensators in non-ideal noise environment.

Adaptive compensation has been popular in a variety of biomedical signal processing applications. One of the major limitations of this method is the requirement for a primary signal + noise channel and a secondary noise channel, with the noises in the two channels being strongly correlated. In the majority of real-life biomedical applications this requirement can rarely be fulfilled since the secondary channel inevitably contains certain representation of the signal from the primary channel thus jeopardizing the adaptive compensation process. In the present work we describe a method for tuning an adaptive compensator containing a non-linear real-time multiplier in the reference channel in such non-ideal noise environment. The method is based on iterative adjustments of an exponential non-linear function which modifies in real-time the signal-to-noise balance in the reference channel in favor of the noise, preserving the correlation of the latter with the noise in the primary (signal + noise) channel but diminishing the signal content in the reference channel. Sets of model signals and noises are used to illustrate this methodology with a particular emphasis on biomedical signal applications. A quantitative description of the iterative tuning procedure is provided and the capabilities and limitations of this novel method for adaptive compensation are outlined.

Artifacts↗
PubMedDate not supplied

Sulbactam/ampicillin: in vitro spectrum, potency, and activity in models of acute infection.

More than 90% of community hospital-isolated strains of Staphylococcus (including methicillin-resistant isolates), Streptococcus, Haemophilus, Neisseria, Branhamella, Bacteroides, Escherichia coli, Klebsiella, Enterobacter aerogenes, Proteus, and Acinetobacter calcoaceticus were inhibited by the sulbactam/ampicillin (1:2) combination at concentrations of 8 micrograms/16 micrograms per ml. The peak serum level from a 15-min infusion of 1 g/2 g of sulbactam/ampicillin is more than seven times this 90% end point. Excellent bactericidal activity was demonstrated against ampicillin-resistant isolates. Ampicillin-resistant strains did not develop resistance to sulbactam/ampicillin when they were serially transferred in the presence of sublethal concentrations of the combination. In mice the combination was active against a variety of acute, fatal infections produced by ampicillin-resistant bacterial isolates, including methicillin-resistant strains of Staphylococcus aureus and mixed anaerobes. The in vitro and in vivo properties of sulbactam/ampicillin, coupled with its reliable pharmacokinetic performance, appear to make the combination ideally suited for the treatment of polymicrobial (aerobe-anaerobe) infections.

Acute Disease↗
PubMedDate not supplied

Altered turnover of polyphosphoinositides in the erythrocyte membrane of the spontaneously hypertensive rat.

The metabolism of inositol phospholipids of the erythrocyte membrane was compared in normotensive Wistar-Kyoto (WKY), spontaneously hypertensive (SHR), and stroke-prone SHR (SHR-SP) rats. This was performed on isolated ghost membranes by measuring the incorporation of 32P from [ gamma-32P ] adenosine triphosphate (ATP) into the diphosphoinositides (DPI) and the triphosphoinositides (TPI) which were the only 32P-labeled phospholipids. 32P-labeling of TPI was altered in adult and 3-week-old SHR as well as in SHR-SP compared to WKY controls; the radioactivity associated with TPI in hypertensive rats was about 30% lower than that associated with TPI in age-matched normotensive controls. By contrast, the radioactivity associated with DPI was similar in both hypertensive and normotensive rats. Measurement of the phosphoinositide distribution in both SHR and WKY indicates that the change observed in 32P-TPI could not be accounted for by a reduced phosphatidylinositol content in SHR membrane. Measurement of the Mg2+-activated TPI-phosphomonoesterase and of the Ca2+-activated polyphosphoinositide phosphodiesterase activities did not show any significant difference between SHR and WKY. It thus appears that the altered phosphoinositide metabolism observed in hypertensive rats was a consequence of some alteration in the activity of kinases which are responsible for the conversion of phosphatidylinositol into DPI and TPI. These results also suggest that the defect in phosphoinositide metabolism observed in genetically hypertensive rats was not a consequence of the blood pressure elevation and could be related to the pathogenesis of hypertension.

Animals↗