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Biomedical subjects

R M Kenney

Publications and source records attributed to R M Kenney.

At least 73 records · Page 4Linked to original sources

Statistical approach to antigen screening.

Pretransfusion testing includes screening the serum of patients for clinically significant antibodies. When discovered, attempts are made to identify the antibody in the hopes of providing the patient with compatible blood that lacks the corresponding antigen. The statistical relationships among the probability of finding the desired number of units, the number of units screened, and the antigen frequency will be discussed. Graphic presentations highlight the relationships and provide a convenient method of assessing the likelihood of finding the desired number of units. A program to perform the necessary calculations on a microcomputer is discussed and is available upon request from the author.

Blood Grouping and Crossmatching↗

Lesions of contagious equine metritis in mares.

Twenty-three mares were infected with contagious equine metritis organism by intrauterine inoculation, and necropsied after intervals of two to 116 days. Severe diffuse subacute salpingitis was seen in one mare, and mild multifocal subacute salpingitis was common. Severe diffuse endometritis and cervicitis initially were acute and became more severe, subacute and predominantly plasmacytic by 14 days, then declined but persisted as mild diffuse or multifocal inflammation for the rest of the experimental period. Vaginitis arose in parallel but resolved after 70 days. There were no lesions in the clitoral fossa or clitoral sinus.

Animals↗

Contagious equine metritis: distribution of organisms in experimental infection of mares.

After contagious equine metritis bacteria were inoculated into the uterus of mares, genital tract tissues were examined for presence of the organism by bacteriologic cultural technique and an indirect immunofluorescent staining technique. Up to 14 days after mares were inoculated, the organism was frequently in the lumen of the uterus and in the cervix and, less frequently, in the vagina, vestibule, clitoral fossa, clitoral sinus, and uterine tubes. After 21 to 116 days, the organism was occasionally found on the ovarian surface, in the uterine tubes, uterus, cervix, and vagina and more frequently in the clitoral sinus and clitoral fossa. The distribution of organisms in the remainder of the genital tract was not different in mares that had been clitorectomized.

Animals↗

Studies on the composition and antibacterial activity of uterine fluid from mares.

Forty uterine fluid samples were obtained during oestrus and dioestrus of successive cycles from 4 mares classified as resistant to bacterial infection of the uterus. The flushings were assayed for peroxidase activity and ability to influence phagocytosis by polymorphonuclear neutrophils. Uterine fluid volumes and protein concentrations and serum oestrogen values were similar during oestrus and dioestrus. Serum progesterone concentrations were depressed during oestrus. Equine neutrophils adherent to glass slides were exposed to a genital strain of Streptococcus zooepidemicus suspended in saline. Neutrophil phagocytosis was significantly higher when cells were incubated with oestrous uterine fluid than with dioestrous fluid. The addition of 5% serum to the incubation medium increased the rates of in-vitro phagocytosis, but these did not differ between oestrus and dioestrus. Rates of phagocytosis with and without serum were not correlated with serum oestrogens or progesterone, or with protein content of uterine fluid. Peroxidase activity of uterine fluid in the absence of infection was negligible throughout the oestrous cycle. There were no significant correlations between peroxidase levels and serum oestrogens or progesterone, but the correlation between peroxidase and protein concentration of uterine fluid was significant (r = 0 X 87). Bacterial or fungal infections led to increased protein content of uterine fluid, and usually marked increases in peroxidase, both probably derived from the visibly obvious populations of leucocytes.

Animals↗

Recovery of contagious equine metritis organisms and development of lesions in experimental infection of mares.

Twenty-three of 24 mares were infected experimentally with contagious equine metritis organisms by intrauterine inoculation, and killed 2-116 days later. From mares killed within 14 days after infection the organism could be recovered from many sites in the uterus, and most sites in the cervix, a few sites in the vagina and oviduct and from one clitoral sinus. At this time the endometrial folds were swollen and there were 10-20 ml of fluid in the uterus. In mares killed after 14 days, the organism was recovered from the ovarian surface (1 mare), oviduct (4 mares), uterus (2 mares) and the clitoral sinus (3 mares). Severe diffuse endometritis and cervicitis was initially acute, and became more severe subacute and predominantly plasmacytic by 14 days, then declined but persisted throughout the experiment.

Acute Disease↗

Comparison between two techniques for endometrial swab culture and between biopsy and culture in barren mares.

The endometria of 77 barren mares was swabbed simultaneously using a swab guarded with a single cannula and distal, gelatin capsule (completely guarded swab - CGS) and a partially guarded swab (PGS) with an open cannula. Sheep blood (5%) agar plates were inoculated with each swab, while MacConkey's agar plates were inoculated with the swabs from 44 mares. The presence of bacterial or fungal growth was determined after 24 and 48 hours of aerobic incubation at 37 C. Organisms present were identified, counted, and categorized as saprophytic or pathogenic flora. The endometria of all mares were biopsied immediately following swabbing. Histologic evidence of inflammation in biopsy specimens was classified as (1) none, (2) slight, discrete, focal, and (3) slight or moderate, diffuse, widespread infiltration of inflammatory cells. The number of inflammatory cells migrating through the luminal epithelium was counted and averaged. There were significantly fewer CGS than PGS cultures that yielded growth at 24 and 48 hours of incubation after being streaked on blood agar and MacConkey's agar plates. There were fewer pathogenic bacterial or fungal colonies present at 48 hours of incubation on blood agar plates after being streaked with CGS as compared to PGS. There were no differences in the number of pathogenic bacterial or fungal colonies present at 24 hours of incubation on blood agar or at 24 and 48 hours of incubation on MacConkey's agar plates. There was no correlation between CGS or PGS culture of pathogens and severity of histologic inflammation. There was a positive correlation between culture of pathogens and number of inflammatory cells migrating through the luminal epithelium.

Journal Article↗

Comparison of two techniques for obtaining endometrial bacteriologic cultures in the mare.

The endometria of 39 mares were cultured simultaneously using a swab guarded with a double cannula and distal, teflon plug and an unguarded swab with a single, open cannula. Sheep blood (5%) agar, Mac-Conkey's agar, and Sabourad's agar media were innoculated with each swab. The presence of bacterial or fungal growth was determined after 24 and 48 hours of aerobic incubation at 37 C. There were significantly more plates that failed to yield bacterial or fungal growth when streaked with swab specimens obtained with the guarded cannula than when streaked with those obtained with the unguarded cannula. It was concluded that while culturing the endometrium of mares for bacteria or fungi, the use of a guarded instrument consisting of a double cannula with a closed end will result in the recovery of fewer contaminants; therefore, it will be more likely to result in a more accurate representation of uterine bacterial and fungal flora.

Journal Article↗

Poisoning with N-3-pyridylmethyl-N'-p-nitrophenylurea (Vacor). Immunoperoxidase demonstration of beta-cell destruction.

A 49-year-old woman ate N-3-pyridylmethyl-N'-p'nitrophenylurea (PNU; Vacor) and was admitted to the hospital 12 hours later with a blood glucose level of 940 mg/dl and an anion-gap metabolic acidosis. Her diabetes was successfully treated, but she contained to manifest severe orthostatic hypotension. A painless ileus developed, followed by cecal perforation and death. Immunoperoxidase staining of paraffin-embedded pancreatic tissue obtained during postmortem examination clearly demonstrated the pancreatic beta-cell destruction. Results of this same staining technique also suggested that fewer alpha cells were present.

Brain↗

Two glutamine synthetases from Bacillus caldolyticus, an extreme thermophile. Isolation, physicochemical and kinetic properties.

Two distinctly different glutamine synthetase enzymes (EI and EII) have been isolated from the extreme thermophile Bacillus caldolyticus, grown on chemically defined medium at 70 degrees C. Purification to homogeneity mainly involves affinity chromatography and heat treatment with substrate protection. Biosynthesis of total enzyme activity can be repressed by at least 8-fold by high ammonia, with synthesis of EI being repressed more strongly than EII. A variety of chemical and biochemical tests failed to provide evidence for regulation of EI or EII by covalent modification, e.g. proteolysis, phosphorylation, or adenylylation. Neither of the thermophiic enzymes will cross-react with antibodies for the Escherichia coli or Bacillus subtilis glutamine synthetases. Both enzymes are composed of 12 subunits, each approximately 51,000 daltons. However, EI and EII differ significantly in their amino acid composition, isoelectric points (5.2 and 5.5, respectively), rates of migration on polyacrylamide electrophoresis gels at pH 6.8, and kinetic properties, EI is more active with Mg(II) than with Mn(II), but EII is more active with Mn(II) than Mg(II). Cd(II) activates EII more than EI, and only EI shows activity with Co(II). For both enzymes, the Mn(II)-stimulated activity is optimal at pH 6.0 to 6.5, with Mn(II)/ATP = 1.0, but the pH optimum with Mg(II) is near pH 7.5, however, with a ratio of Mg(II)/ATP > 2. Substrate Km values at 70 degrees C differ for EI versus EII but are quite comparable to those seen for mesophilic glutamine synthetases. Studies with structural analogs of substrates indicate that active site specificity is maintained at extreme temperatures: substitution of alpha-OH for alpha-HN2 is allowed, but unfavorable changes occur upon substitution of methyl groups for the alpha-H or onto the alpha-NH2 of L-Glu, and for D-Glu or L-Asp. EII is almost absdolutely specific for ATP, but EI can also use ITP, GTP, and UTP as substrates to some extent. The divalent metal ion that is present can affect both specificity for analogs and substrate Km values. Kinetic binding plots (v versus [S]) are biphasic for NH3 and L-Glu with the more active forms of each enzyme, EI-Mg and EII-Mn, respectively; but no positive cooperativity is observed. ATP binding is strictly hyperbolic, in contrast to the positive cooperativity previously observed with other Bacillus sp. enzymes. For purified EI and EII, Arrhenius plots are nonlinear with Mn(II) or Mg(II), exhibiting slope changes in the range of 55-65 degrees C; however, for EI-EII mixtures in crude cell extracts these plots are nearly linear.

Amino Acids↗

A cohort study of canine testicular neoplasia.

A prospective epidemiologic study of canine testicular neoplasia was undertaken in the Philadelphia area in 1971, with the cooperation of private veterinary practitioners. By the end of 1975, 938 dogs had been monitored for an average of 2 years. The cohort consisted of 609 cryptorchid and 329 age- and breed-matched controls. The incidence of testicular neoplasia in the cryptorchid subcohort was 12.7/1,000 dog-years at risk. Testicular neoplasms did not develop in controls. A large proportion of the dogs were below the average age at onset for this neoplasm. Among dogs over 6 years of age, the incidence was 68.1/1,000 dog-years at risk. The incidence of Sertoli cell tumors and seminoma was approximately twice as high in dogs with unilaterally retained inguinal testicles as in abdominal cryptorchids. Sertoli cell tumors developed in 10 dogs and seminoma developed in 6. One half of the testicular neoplasms that developed did so within the first year of observation. This study demonstrated the feasibility of conducting prospective epidemiologic studies of canine diseases with the assistance of practicing veterinarians.

Animals↗

Morphological and biochemical correlates of equine ovarian follicles as a function of their state of viability or atresia.

The histological features and hormonal content of follicular fluid of antral follicles during oestrus were correlated. As a result it was possible to characterize several categories of viable and atretic follicles. A seemingly important stage in maturation appeared to be at 3 cm in diameter since follicular oestrogens and androgens underwent a 3-fold increase in concentration at that size. Evidence was obtained to suggest that oestrogens are anti-atretogenic. However, a drop in oestrogens was not the cause of atresia since degeneration commenced when levels were high. Contrary to the concept that androgens are atretogenic in some species, it was also evident that elevated androgens did not precipitate spontaneous atresia. Theca epithelioid cells not only underwent histological luteinization in viable follicles as they matured toward ovulation but occasionally in atretic follicles as well. Elevated prostaglandin F levels were associated with follicles in the transitory states of either luteinization or atresia. Granulosa cells of viable follicles only were capable of specifically binding hCG. It was not determined whether loss of binding capacity or atresia occurred first. Follicular atresia in the mare appears to be a gradual process of which the initiating cause remains unknown.

Androgens↗

Catecholamines and equine luteal progestagens.

Corpora lutea (CL) from 7 mares were sliced and incubated for 2 h with ovine LH and various sympathomimetic agonists and blockers. None of these compounds was able to cause a significant increase in either progesterone or total progestagens by the luteal tissue. This is in contrast to earlier studies with bovine luteal tissue, and indicates that the equine CL is more refractory to exogenous stimulation than in the bovine CL.

Animals↗

Clinical, microbiological and histological changes associated with uterine involution in the mare.

The surprisingly rapid rate of uterine involution detected is consistent with a high rate of conception as the first post-partum heat. Furthermore, many of the immediately post-partum features have attained the pregravid state by the end of the first post-partum oestrus and virtually all by the second post-partum oestrus. There was no specific cause detected for the higher rate of early embryonic death associated with conception at the foal heat.

Animal Husbandry↗