Search PubMed⌕ Search

Biomedical subjects

R Hudson

Publications and source records attributed to R Hudson.

At least 91 records · Page 5Linked to original sources

A hospital cafeteria-related food-borne outbreak due to Bacillus cereus: unique features.

Although Bacillus cereus is a well-known cause of food-borne illness, hospital-related outbreaks of food-borne disease due to B. cereus have rarely been documented. We report a hospital employee cafeteria outbreak due to foods contaminated with B. cereus in which an outside caterer was employed to prepare the suspect meals. Data were collected from 249 of 291 employees who had eaten either of the two meals. With a mean incubation period of 12.5 hours, 64% (160 of 249) of employees manifested illness. Symptoms, which averaged 24.3 hours in duration, included diarrhea (96.3%), abdominal cramps (90%), nausea (50.6%), weakness (24.7%), and vomiting (13.8%). Eighty-seven employees sought medical attention, 84 of whom were seen in an emergency room. Although a significant difference was not demonstrated in food-specific attack rates, B. cereus was cultured from both rice and chicken items that were served at both meals. Sixty-three employees submitted stools for culture that grew no enteric pathogens, but none were examined for B. cereus. This food-borne outbreak demonstrates: the need for hospital kitchen supervisors to ensure proper handling of food when outside caterers are employed; that significant differences in food-specific attack rates may not be demonstrated in outbreaks, which may be related to several factors; and the importance of notifying microbiology laboratory personnel when B. cereus is a suspect enteric pathogen, since many laboratories do not routinely attempt to identify this organism in stool specimens.

Animals↗

Do newborn rabbits learn the odor stimuli releasing nipple-search behavior?

Rabbit pups do not need to learn postnatally the pheromonal cues releasing nipple-search behavior. Pups delivered by caesarean section were able to attach to nipples as quickly as normally delivered controls in their first encounter with a lactating doe (Experiment I), and pups hand raised to Day 5 without postnatal experience of the nipple-search pheromone even showed an improvement in their reactivity to it similar to normally raised controls (Experiment II). However, 1-day-old pups could be conditioned during the first nursing episode to respond with nipple-search behavior to artificial odors painted on the mother's ventrum (Experiment III). Finally, pups conditioned on Day 1 but subsequently raised by hand or normally nursed showed retention of the conditioned responsiveness when tested on Day 5 (Experiment IV). These experiments suggest that although rabbit pups are capable of rapidly associating odors with suckling, they do not appear to depend on this ability under normal nursing conditions.

Animal Population Groups↗

The contribution of the olfactory and tactile modalities to the nipple-search behaviour of newborn rabbits.

By performing uni- and bilateral olfactory bulb lesions and uni- and bilateral transsections of the infraorbital branches of the trigeminal nerves in 2-day-old rabbits, it could be shown that: Both the olfactory and tactile modalities are essential for the successful performance of nipple-search behaviour. While bilateral bulbectomy completely eliminates searching, and hence suckling, unilateral bulbectomy has relatively little effect. Bilateral denervation of the muzzle does not eliminate searching, but pups are unable to suckle as they fail to show the mouth-opening component necessary for nipple attachment. In contrast to unilateral bulbectomy, unilateral denervation of the muzzle results in a lateralization of head movements during searching, nipple grasping and nipple release.

Animal Population Groups↗

Ophthalmic trauma.

Explore the source record for details and available documents.

Burns, Chemical↗

Electrophysiology of Necturus urinary bladder: II. Time-dependent current-voltage relations of the basolateral membranes.

As reported previously (S.R. Thomas et al., J. Membrane Biol. 73:157-175, 1983) the current-voltage (I-V) relations of the Na-entry step across the apical membrane of short-circuited Necturus urinary bladder in the presence of varying mucosal Na concentrations are (i) time-independent between 20-90 msec and (ii) conform to the Goldman-Hodgkin-Katz constant field flux equation for a single cation over a wide range of voltages. In contrast, the I-V relations of the basolateral membrane under these conditions are (i) essentially linear between the steady-state, short-circuited condition and the reversal potential (Es); and (ii) are decidedly time-dependent with Es increasing and the slope conductance, gs, decreasing between 20 and 90 msec after displacing the transepithelial electrical potential difference. Evidence is presented that this time-dependence cannot be attributed entirely to the electrical capacitance of the tissue. The values of gs determined at 20 msec are linear functions of the short-circuit current, Isc, confirming the relations reported previously, which were obtained using a more indirect approach. The values of Es determined at 20 msec are significantly lower than any reasonable estimate of the electromotive force for K across the basolateral membrane, indicating that this barrier possesses a significant conductance to other ions which may exceed that to K. In addition, these values increase linearly with decreasing Isc and approach the value of the electrical potential difference across the basolateral membrane observed when Na entry across the apical membrane is blocked with amiloride or when Na is removed from the mucosal solution. A possible explanation for the time-dependence of Es and gs is offered and the implications of these findings regarding the interpretation of previous microelectrophysiologic studies of epithelia are discussed.

Animals↗

Detection of rotavirus in human stools by using monoclonal antibody.

A monoclonal antibody, 3F7, that reacts with the common rotavirus antigen on the sixth viral gene product was prepared. It was used in a direct monoclonal antibody radioimmunoassay (RIA) as a diagnostic reagent for detection, in 3.5 h, of rotavirus in human pediatric stool specimens. In the 177 samples tested, a concordance of 96% was seen between the monoclonal RIA and the well-established and commonly used commercially available Rotazyme test. Six discrepant specimens that were positive by monoclonal RIA but negative by Rotazyme were shown to be positive by either electron microscopy or confirmatory blocking immunoassay. A seventh discrepant specimen was positive by Rotazyme and negative by monoclonal RIA as well as by both direct and immune electron microscopy. The monoclonal RIA test appears to be highly sensitive and specific, and merits additional evaluation as a rapid, convenient diagnostic assay that can reduce currently encountered problems associated with diagnosing rotavirus infection by immunoassay.

Antibodies, Monoclonal↗

Visual versus computerised assessment of left ventricular function from cinéangiography.

Visual assessment of left ventricular function from cinéangiography was compared with computerised assessment in 48 randomly selected cinéangiograms. The parameters compared included end-diastolic volume, end-systolic volume, stroke volume, ejection fraction and left ventricular output. There was poor agreement between visual and calculated values for end-diastolic volume, stroke volume and left ventricular output, but good agreement for ejection fraction and moderately good agreement for end-systolic volumes. Absolute values are particularly difficult to assess.

Cardiac Output↗

Alfathesin and enflurane: synergistic central nervous system excitation?

This case report describes signs of central nervous system excitation occurring after administration of alfathesin and enflurane in doses lower than those previously associated with this type of phenomena (alfathesin 36 microlitres/kilogram, enflurane two volumes per cent). This suggests that these drugs may interact to increase the probability of seizure-like activity.

Adult↗

Experimental observations on the effects of leg lengthening by the Wagner Method.

A proximal tibial epiphysiodesis was successfully performed on the right hind legs of 23 young lambs, producing an average shortening of 12% of the total length of the tibia. A lengthener was attached to stainless steel pins which were then tapped into the shortened tibia prior to osteotomy. In 16 of the 23 animals it was possible to lengthen the shortened bone at a rate of 0.5 mm twice daily until the discrepancy was corrected. The gait was normal in most of the animals, all had full knee motion with no thigh atrophy, and 16 had limited hock (ankle) joint motion. Lengthening of the tibia by more than 11% consistently produced muscle changes in the leg and cartilage damage in the hock (ankle) joint. Any malalignment of the tibial fragments during lengthening intensified these changes.

Animals↗

Saint Augustine's College training program in industrial hygiene and safety.

The Occupational Safety and Health Program at St. Augustine's College leads to a Bachelor of Science degree in Industrial Hygiene. This program enables the students to enter careers in practice and research in industry and government or to pursue graduate studies. The curriculum in industrial hygiene provides a broad academic foundation during the first two years of college, after which, students proceed with advanced studies in industrial hygiene and supporting courses in the natural and behavioral sciences. St. Augustine's College industrial hygiene and safety curriculum course descriptions are presented and other aspects of the program are discussed.

Curriculum↗

Lymphocyte-like cells of the tunicate, Pyura stolonifera: binding of lectins, morphological and functional studies.

In vitro investigations were carried out to determine whether lymphocyte-like (small round) cells of the tunicate Pyura stolonifera react to allogeneic cells and mitogens in a manner comparable to that of vertebrate immunocytes. The lymphocyte-like cells possessed receptors for concanavalin A, wheat germ agglutinin and soybean lectin as shown by binding of radioiodinated lectins in scintillation counting and autoradiographic assays. This binding did not induce mitogenesis. Mixtures of cells of P. stolonifera individuals taken from the same or distinct localities did not show enhanced DNA synthesis when assayed at time intervals ranging from 3 to 10 days. The small round cells of this and other tunicates are not completely similar to vertebrate lymphocytes in morphology. Our observations support the concept that these cells are not directly homologous to immunologically competent vertebrate lymphocytes, but may serve as haemopoietic stem cells as proposed by other (Endean, 1954; Freeman, 1970).

Animals↗

Rapid antibiotic disk sensitivities of burn eschar and infected wounds.

This study was undertaken to develop a more rapid antibiotic sensitivity test of the pathogens in soft tissue infections and burn wound eschar. The proposed rapid antibiotic sensitivity test was performed directly on the clinical specimen rather than on single strains of bacteria isolated from the tissue. By performing the antibiotic sensitivity tests directly on the tissue sample, the physician obtains the test results within seven hours after receiving the specimen rather than 38 to 52 hours later, the time delay encountered with the conventional technique. The modification used did not alter most of the standards advised by the Food and Drug Administration (3), since there was no inclusive change in medium, agar depth or antibiotic sensitivity disk. The changes in the Kirby-Bauer (1) test necessitated by using the clinical specimen did not alter significantly the interpretation of the antibiotic susceptibility. If clinically significant numbers of bacteria, 10(6)-10(9), were present, variations in the inoculum size did not appreciably change the results of the antibiotic susceptibility tests. If the incubation requirement for the standard Kirby-Bauer (1) antibiotic susceptibility test was reduced to seven hours, it also did not significantly limit the accuracy of the test. As expected, the variable most difficult to standardize was the heterogeneous inoculum containing large numbers, 10(7), of different organisms. A zone of inhibition interpreted as sensitive with one organism was occasionally masked by the presence of the confluent growth of an organism in which the zone of inhibition was considered resistant. However, even in this instance, it is possible that mixed culture sensitivities may provide the most valid information in mixed infections, since they more closely simulate the real clinical situation.

Anti-Bacterial Agents↗