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Biomedical subjects

J D Kerr

Publications and source records attributed to J D Kerr.

36 records · Page 2Linked to original sources
PubMed1978

Boophilus microplus: rejection of larvae from British breed cattle.

Larvae of Boophilus microplus were labelled with [32P] and used to study the rejection of larvae from British breed cattle with different levels of resistance. On animals of high resistance the loss of larvae due to grooming ranged from 9-54% during the first 24 h of infestation, and more time was spent grooming by these animals. Most of the grooming activity could be attributed to the presence of tick larvae and the presence of older tick stages did not increase the percentage of larvae lost. Grooming was directed to attached larvae and these could be removed. Animals of low resistance did not lose a significant number of larvae as a result of grooming, but all previously infested hosts lost a proportion of the larvae (18-39%) which could not be accounted for by grooming. This loss was greater than the total loss of larvae (11%) on animals not previously exposed to B. microplus.

Animals↗
PubMed1976

Boophilus microplus: the effect of host resistance on larval attachments and growth.

Growth and behaviour of Boophilus microplus larvae on British breed cattle, with different resistance levels to the tick, were studied to elucidate the nature of resistance. On highly resistant animals, larval growth rate was slower for the first 3 days, but by day 4 they had attained the normal weight and the majority were subsequently able to moult. Using phosphorus-32 labelled larvae, it was found that attachment times were shorter and more time was spent wandering on highly resistant animals during the first 16 h. On the second day, attachments had stabilized, but more detachments were still made from highly resistant animals. This was considered to impose an additional stress as the cattle skin environment can rapidly desiccate larvae. However, the larvae were able to compensate by uptake of fluid from the host. Loss by repulsion of live larvae from the host or drowning in serous exudate were also not considered of major importance. The nature of rejection is discussed in a further paper. The distribution of larvae after 24 h suggests that their early behaviour largely determines the areas favoured by adults. Movement to, and accumulation in, favoured areas is discussed.

Animals↗
PubMed1975

Effect of trasylol on packed cell volume and plasma kallikrein activation in acute Babesia argentina infection of splenectomised calves.

Three groups of four splenectomised calves, three months old, were infected with Babesia argentina parasites. One group was inoculated intravenously with 2000 kallikrein inhibitor units (kiu)/kg body weight of the broad-spectrum proteinase inhibitor, Trasylol, three times a day for 5 days commencing on the 3rd day after infection (early treatment). The same dose of Trasylol was given to a second group for 3 days commencing 8 days after infection (late treatment). The third group was untreated. Parasite multiplication rates were similar in the three groups. In the early treated group levels of activated kallikrein in plasma were significantly lower than those in the other two groups. The early treatment group also showed significantly higher levels of plasma kallikrein inhibitor. No significant differences in total plasma kallikrein levels were seen among the three groups. Packed cell volumes in the treated groups remained significantly higher than those in the controls. The implications of these findings are discussed.

Analysis of Variance↗
PubMed1975

Feeding of Boophilus microplus larvae on a partially defined medium through thin slices of cattle skin.

Larvae of the cattle tick Boophilus microplus will attach to thin (0-3--0-5 mm) slices of cattle skin and engorge on a partially defined medium at 35 degrees C. Forty-seven to 83 per cent of the larvae had engorged by 8 days, and 51--71 per cent of these moulted to nymphs. Tissue culture medium alone allowed little growth unless supplemented with dialysed, freeze dried bovine serum (7 per cent, w/v). This medium could be further difined by substituting purified bovine serum albumin (Cohn fraction V) for the dialysed bovine serum. In one experiment, nymphs of Haemaphysalis longicornis engorged and later moulted to adults. Skin slices were used fresh or after freeze-drying and storing at --25 degrees C. The possible uses of the culture method are discussed.

Animals↗
PubMedDate not supplied

MRI safety: everyone's job.

It seems that in most hospitals, the MRI department is the only department charged with ensuring MRI safety. Unfortunately, it took the tragic loss of a patient's life in a New York hospital has served to bring the topic of MRI safety forward in the minds of many healthcare leaders. Of course, safety in the MR imaging suite has long merited the attention it is now receiving. Medical professionals agree it should receive the very highest of priority. However, bringing that goal from concept to reality is a real challenge--one that St. Luke's Episcopal Hospital in Houston, Texas, accepted and met. Our success, we believe, resulted from promoting MRI safety as a hospital-wide concern and investigating and then implementing several specific measures to maximize patient safety. In addition to our own evaluation of existing procedures and policies, St. Luke's enlisted the help of two outside consultants to perform separate comprehensive MR safety evaluations of our facility. Among the suggestions offered by the consultants was improvement in our MRI safety form. Taking the safety form on the MRIsafety.com Web site as a guide, we made certain modifications to our form, then met with our nursing councils to gain their input. The result has been a dramatic increase in compliance. All MRI technologists must have the backing of management--and know that they have it. Management must empower the technical staff to adhere to safety principles, even when it means enforcing safety rules with physicians. Disseminating MR safety information to the appropriate personnel in a health facility can be a daunting task. We found video to be the most effective means of presenting MR safety information. Some MR vendors can supply a safety video that gives excellent examples of non-MRI safe equipment. The MR supervisor will find it beneficial to distribute the video to any department that might have access to the MRI suite. Today at St. Luke's, MRI safety is not a topic for annual review; instead, it is on the minds of our staff with each and every patient.

Communication↗