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Biomedical subjects

P Collins

Publications and source records attributed to P Collins.

At least 379 records · Page 21Linked to original sources

Isolation of mycobacteria from dairy creamery effluent sludge.

Sixty three samples of dairy creamery effluent were examined for the presence of mycobacteria. Thirty two strains were isolated from 27 samples. These were classified as follows: M. fortuitum (13), M. peregrinum (6), M. gordonae(5), M. marianum (scrofulaceum) (4), unidentified (4). Ten strains, representative of the groups isolated, were tested for their effect on experimental animals. None were pathogenic for guinea pigs or mice but a number produced a minimal amount of skin sensitization in guinea pigs to avian and mammalian tuberculin.

Animals↗

The occurrence of salmonellas, mycobacteria and pathogenic strains of Escherichia coli in pig slurry.

Ninety-eight samples of pig slurry from 54 farms were examined for the presence of salmonellas, porcine enteropathogenic strains of haemolytic Escherichia coli and mycobacteria. Salmonellas were isolated from 12 farms (22%) and enteropathogenic E. coli from 13 farms (24%). Pathogenic mycobacteria were not isolated. Salmonellas were isolated from 7 of 16 farms (44%) stocked with 'minimal disease' pigs compared with only 5 of 38 farms (13%) stocked with conventionally reared pigs. Conversely enteropathogenic coliforms were isolated from 3 of 16 farms (19%) stocked with 'minimal disease' pigs compared with 10 of 38 farms (26%) stocked with conventionally reared pigs.

Animals↗

Optimal schedules for use of interferon in the corneas of rabbits with herpes simplex keratitis.

The 50% infectious dose of a preparation of herpes simplex virus was measured in eyes of rabbits by a multiple corneal inoculation method. One hour after inoculation of virus, one eye was treated with drops of human leukocyte interferon, and the other was treated with saline or with a different dose of interferon. Results from groups of three to four rabbits were combined for analysis. Treatment reduced the 50% infectious dose of virus in proportion to the concentration of interferon applied (within the range of 6.5 X 10(4)-1.3 X 10(6) units/ml) and not according to the total number of units instilled. Different treatment schedules were tried. Two applications of interferon each day were as effective as eight applications at intervals of 15 min or 1 hr. One application produced near-maximal antiviral effects for 18-24 hr. Thus, in human herpetic keratitis, a single daily application of the most concentrated available preparation of human interferon might be the most efficient schedule of treatment.

Animals↗

Symptomatic mitral myxomatous transformation in the elderly.

The clinical and pathological features of four patients with intractable heart failure, due to myxomatous change in the mitral valve, are described. It is suggested that this change may represent a response of ageing connective tissue to mechanical stress.

Aged↗

Isoprenaline-induced changes in regional myocardial perfusion in the pathogenesis of myocardial necrosis.

Isoprenaline in a single dose induces impairment in perfusion of the subendocardial myocardium of the rat left ventricle. This defect in perfusion persists for up to 150 min and corresponds in distribution to the myocardial necrosis produced by similar doses of isoprenaline. It is mediated by the beta-receptors as it is prevented by beta-blockade with propranolol. It is considered that isoprenaline-induced myocardial necrosis represents myocardial infarction.

Animals↗

Comparative value of four methods of investigating the pancreas.

In a prospective study for the diagnosis of pancreatic cancer, ultrasonography, radionuclide scanning, selective arteriography, and endoscopic retrograde cholangiopancreatography (ERCP) were compared. Eighty-nine consecutive patients were investigated; 58 underwent laparotomy, and 36 were found to have periampullary cancer; seven had other malignant tumors within the abdomen, and nine had pancreatitis on biopsy. Five had other benign disease, and there was one negative laparotomy. Thirty-one patients who did not have laparotomy have shown no evidence of cancer at one year follow-up. Ultrasonography was found to be more reliable than scan or arteriography in the detection and diagnosis of a mass in the pancreas. ERCP achieved the highest rate of correct definitive diagnosis.

Angiography↗

Psychoactive drugs in mania. A controlled comparison of lithium carbonate, chlorpromazine, and haloperidol.

Lithium carbonate, haloperidol, and chlorpromazine hydrochloride were compared in a double-blind controlled study with severely ill hospitalized manics. Lithium carbonate and haloperidol produced a highly significant improvement of manic symptoms without sedation. Although producing considerable sedation, chlorpromazine did little to alter the underlying mania qualitatively. Qualitative differences between lithium carbonate and haloperidol indicate that, while haloperidol has a more dramatically rapid impact on behavior-motor activity, lithium carbonate acted more evenly on the entire manic picture, with total normalization realized during active treatment. The majority of lithium carbonate-treated patients met discharge criteria at study termination, but not the patients receiving either neuroleptic drug. The rating scales are not sensitive enough to monitor manic psychopathology; this accounts for the lack of statistically significant differences among drug groups at treatment termination, despite the widely disparate discharge rates.

Adult↗

Quantitation of isoprenaline-induced changes in the ventricular myocardium.

Small doses of isoprenaline sulphate given intermittently produce a characteristic cardiopathy consisting of subendocardial scarring and myocardial hypertrophy. A morphometric technique was successfully applied to the quantitation of these changes. This technique improves the use of the isoprenaline model for the study of cardiac necrosis as statistical analysis can be applied and objective comparisons made. No hypertrophy was seen in the absence of myocardial necrosis which suggests that it is at least in part compensatory.

Animals↗

Changes in the surface features of choroid plexus of the rat following the administration of acetazolamide and other drugs which affect CSF secretion.

The surface of the choroid plexus of the rat was examined by scanning electron microscopy before and after administration of acetazolamide and other drugs (cardiac glycosides and pilocarpine) which affect the rate of secretion of the CSF. In control animals, bleb-covered cells were more common on the IVth ventricle choroid plexus than on the lateral ventricle choroid plexus (20 per specimen compared to 0-3 per specimen). Following administration of acetazolamide the number of bleb-covered cells was reduced significantly (P less than 0-001). The effects of the other drugs were less well defined. Since acetazolamide is known to interfere with the active transport of the extra chloride ions normally added to the CSF in the IVth ventricle, it is suggested that the bleb-covered cells of the IVth ventricle choroid plexus are the specific site for chloride secretion.

Acetazolamide↗