Feline parvovirus in pedigree kittens.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
H Thompson
Publications and source records attributed to H Thompson.
Serial position and temporal cue effects in multiple sclerosis: two subtypes of defective memory mechanisms.
Neurocognitive studies of multiple sclerosis (MS) have identified a robust long-term memory deficit. We hypothesized that this is due in part to the limited representation and use of serial order information. MS patients and controls were studied with a supraspan list learning procedure with post-encoding retrieval and recognition trials. MS patients demonstrated post-encoding negative recency with normal recognition, and word order recall was impaired. These findings appear to be in part to difficulty using temporal order cues in long-term memory. Two dissociable memory deficits were identified, suggesting that there are at least two neurocognitive mechanisms underlying memory impairment in MS.
Adult↗
Assessment of feeding response of tumor-bearing rats to hypothalamic injection and infusion of neuropeptide Y.
Tumor-bearing rats exhibited significant decreases in 1- to 4-h intake of rat chow following the intrahypothalamic injection of 2 micrograms neuropeptide Y (NPY). This refractory feeding response was present prior to the onset of anorexia and became more severe as anorexia worsened. The constant infusion of NPY (125 ng/h) into the perifornical hypothalamus of TB and control rats elicited increased feeding for only 2 days. Because chromatography revealed minipump NPY to be intact after 10 infusion days, downregulation of NPY receptors may have occurred. Daily injection of increasing doses of NPY stimulated ad lib feeding in non-TB rats, while having no effect on TB rats. Desensitization to NPY-induced feeding following daily injections of the peptide was suggested by the loss of feeding response to a dose (500 ng) of NPY that increased food intake prior to the daily NPY treatments. These results suggest that hypothalamic NPY feeding systems are refractory in TB rats, even before they exhibit anorexia. In addition, a rapid loss of the feeding response occurred in rats with constant infusion of NPY into hypothalamic tissue or with daily intrahypothalamic injections of the peptide, suggesting possible NPY receptor-mediated alterations. Therefore, control of obesity or anorexia through NPY feeding mechanisms may prove difficult due to rapid compensatory receptor changes.
Animals↗
The intensive care unit cost of surviving and dying.
Explore the source record for details and available documents.
England↗
The prevalence of seat belt use in Jamaica. An observational study.
An observational cross-sectional survey showed that 21.1% of private motor vehicle drivers and 13.5% of front seat passengers voluntarily wore seat belts in Kingston, Jamaica, where there is no law requiring this. Rear passenger utilisation was not examined. Compared to males, females were significantly more likely to wear seat belts when driving but not as front seat passengers. Of all motor vehicles examined, 10.1% were not equipped with seat belts. The oldest group of vehicles were mostly not fitted with seat belts. Drivers of older vehicles were significantly less likely to use seat belts even when the vehicles were equipped with belts. Implementation of legislation can reduce mortality, morbidity and costs from road traffic accidents which are relatively frequent in Jamaica. Male drivers, drivers of older vehicles and all passengers may require specific targeting in an educational and enforcement campaign should legislation, which is highly desirable, be implemented.
Adult↗
Physical map and organization of Arabidopsis thaliana chromosome 4.
A physical map of Arabidopsis thaliana chromosome 4 was constructed in yeast artificial chromosome clones and used to analyze the organization of the chromosome. Mapping of the nucleolar organizing region and the centromere integrated the physical and cytogenetic maps. Detailed comparison of physical with genetic distances showed that the frequency of recombination varied substantially, with relative hot and cold spots occurring along the whole chromosome. Eight repeated DNA sequence families were found in a complex arrangement across the centromeric region and nowhere else on the chromosome.
Arabidopsis↗
Dissociation of the genotoxic and growth inhibitory effects of selenium.
The effects of forms of selenium compounds that enter the cellular selenium metabolic pathway at different points were investigated in a mouse mammary carcinoma cell line. The goal of these experiments was to determine if the genotoxicity of selenium, defined as its ability to induce DNA single-strand breaks, could be dissociated from activities proposed to account for its cancer inhibitory activity. The results demonstrated that growth inhibition, measured as inhibition of cell proliferation and induction of cell death, was induced by all the forms of selenium evaluated. However, sodium selenite and sodium selenide, which are metabolized predominantly to hydrogen selenide, caused the rapid induction of DNA single-strand breaks as an early event that preceded growth inhibition. Interestingly methylselenocyanate and Se-methylselenocysteine, which are initially metabolized predominantly to methylselenol, induced growth inhibition in the absence of DNA single-strand breakage. Differences in the time course of selenium retention, in the occurrence of membrane damage, and in the induction of morphological changes by selenite versus methylselenocyanate were noted. Collectively, these data indicate that different pathways affecting cell proliferation and cell death are induced depending on whether selenium undergoes metabolism predominantly to hydrogen selenide or to methylselenol.
Animals↗
A cluster of cases of feline dysautonomia (Key-Gaskell syndrome) in a closed colony of cats.
Twenty-five cases of feline dysautonomia (Key-Gaskell syndrome) occurred in a closed cat colony over a period of three weeks. The clinical and pathological signs were sufficiently similar to those reported during the 1982-1986 outbreak to establish a positive diagnosis. The special epidemiological and environmental circumstances of the outbreak provide a new insight into the cause(s) of the syndrome.
Animals↗
Comparison of isolates of canine parvovirus by restriction enzyme analysis, and vaccine efficacy against field strains.
Canine parvovirus isolates from clinical cases of enteritis were obtained from the United Kingdom, Germany and the USA and differentiated by restriction enzyme analysis into three groups, namely CPV2, CPV2a and CPV2b. The three groups were readily identified by their HphI restriction profile. CPV2 was not prevalent in cases of canine parvovirus disease after 1986. Only two CPV2 strains (original type) were found among 110 strains isolated after 1980. In Europe the frequency of isolation of the CPV2a and CPV2b field strains was similar whereas in the USA the CPV2b strain predominated. Dogs inoculated with a vaccine strain were resistant to infection after challenge with UK isolates of CPV2a and CPV2b.
Animals↗
Suppression of experimental proliferative vitreoretinopathy by sustained intraocular delivery of 5-FU.
Treatment of proliferative vitreoretinopathy (PVR) requires a multidimensional approach. Recent studies have focused on pharmacologic techniques to inhibit intraocular cell proliferation by applying antimetabolite drugs. Side effects associated with these drugs and difficulties in achieving effective concentration inside the eye make drug delivery an important and difficult part of this approach. We have developed a sustained-release bioerodible device with modifiable release properties for intraocular drug delivery. In this study, we evaluated the efficacy of the device with two different concentrations of 5-fluorouracil (5-FU) in an experimental model of PVR in rabbit eyes. Both devices showed significant (P < 0.05) efficacy in prevention of PVR. Devices containing 20% 5-FU (total of 1 mg) were 100% effective in prevention of tractional retinal detachment. No significant complications, other than mild vitreous hemorrhage in a few cases, were associated with this method. Because pharmacologic therapy is used as an augmenting method to surgical therapy, these devices can be easily implanted inside the eye through a sclerotomy at the completion of surgery without any discomfort to patients. Slow release of drug by this method reduces the incidence of toxicity and increases the efficacy by providing a constant concentration of drug during the active period of the disease.
Animals↗
Anorectic and neurochemical effects of pituitary adenylate cyclase activating polypeptide in rats.
Pretreatment of rats with intrahypothalamic injections of pituitary adenylate cyclase activating peptide (PACAP) 10 min prior to the injection of neuropeptide Y (NPY) significantly reduced food and water intake during the 4-h measurement period. Intrahypothalamic injection of PACAP in schedule-fed rats also reduced food and water intake for 2 h. A smaller 1-h reduction of water intake was observed in water-deprived rats, suggesting that the anticonsummatory effects of PACAP were primarily against food intake. PACAP treatment did not alter hypothalamic concentration of NPY, nor were neurotransmitters, precursors, or metabolites altered substantially in corpus striatum or nucleus accumbens regions. These results demonstrate primary anorectic effects of intrahypothalamic injection of PACAP. The demonstration of these anorectic effects may suggest a role of cyclic AMP activation and inhibition in the control of satiety and hunger.
Adenylyl Cyclases↗
Effect of timing and duration of dietary conjugated linoleic acid on mammary cancer prevention.
Conjugated linoleic acid (CLA) is a minor fatty acid found predominantly in the form of triglycerides in beef and dairy products. Previous work by Ip and co-workers showed that free fatty acid-CLA at < or = 1% in the diet is protective against mammary carcinogenesis in rats. The present study verified that the anticancer activities of free fatty acid-CLA and triglyceride-CLA are essentially identical. This is an important finding, because it rules out a nonspecific free fatty acid effect. In terms of practical implication, we can continue the in vivo research with the less-expensive free fatty acid-CLA without compromising the physiological relevance of the data. A primary objective of this report was to investigate how the timing and duration of CLA feeding might affect the development of mammary carcinogenesis in the methylnitrosourea (MNU) model. We found that exposure to 1% CLA during the early postweaning and pubertal period only (from 21 to 42 days of age) was sufficient to reduce subsequent tumorigenesis induced by a single dose of MNU given at 56 days of age. This period incidentally corresponds to a time of active morphological development of the mammary gland to the mature state. In contrast to the above observation, a continuous intake of CLA was required for maximal inhibition of tumorigenesis when CLA feeding was started after MNU administration, suggesting that some active metabolite(s) of CLA might be involved in suppressing the process of neoplastic promotion/progression.
Animals↗
Cellular and metabolic effects of triphenylselenonium chloride in a mammary cell culture model.
Triphenylselenonium chloride, a novel synthetic organic selenium compound in which selenium is bonded to three unsubstituted benzene rings, possesses significant chemopreventive activity against chemically-induced mammary carcinogenesis. The effects of triphenylselenonium chloride on a mammary tumor cell line (MOD) were compared to selenite, a reference compound in selenium chemoprevention research. It was observed that triphenylselenonium chloride treatment exerted a cytostatic effect in the absence of membrane damage or DNA strand breaks. The observed cytostasis was associated with a selenium concentration-dependent inhibition of cell proliferation, measured by [3H]thymidine incorporation into DNA, and delayed cell cycle progression. In contrast, selenite treatment rapidly induced DNA damage and cell death. These marked differences were observed across the same levels of cellular selenium. In addition, triphenylselenonium chloride treatment increased glucose consumption and lactate production, indicating an effect of the compound on cellular energy metabolism. Collectively these observations demonstrate that the toxic activities associated with selenite treatment do not occur when cells are treated with triphenylselenonium chloride. This compound represents a new type of selenium compound that exerts significant cellular effects through mechanisms distinct from those induced by selenite.
Animals↗
Sentence comprehension in multiple sclerosis.
INTRODUCTION: Explanations of sentence processing difficulty in aphasia have implicated slowed information processing speed. We tested this hypothesis by evaluating sentence comprehension in multiple sclerosis (MS), and relating comprehension performance to measures of information processing speed. MATERIAL & METHODS: Twenty right-handed, high school-educated, non-demented, native English speakers with clinically definite MS and 16 age- and education-matched control subjects were examined on 3 different sentence comprehension measures that stress grammatical appreciation. Performance was related to quantitative assessments of mental information processing speed. RESULTS: Group-wide analyses demonstrated a trend toward sentence comprehension difficulty in MS. Analyses of individual patient profiles identified a subgroup of MS patients who were consistently impaired to a significant extent across all sentence comprehension tasks. Their sentence comprehension difficulty was associated with selectively compromised mental information processing speed. CONCLUSION: Sentence comprehension difficulty in MS is associated with slowed information processing speed. This finding supports the claim that information processing speed contributes to sentence processing.
Adult↗
Vaginal cysts causing tenesmus in a bitch.
An eight-year-old female border collie was referred with a two-month history of faecal tenesmus. Ultrasonography and radiology identified fluid-filled masses in the cranial vagina. The fluid was drained from the vaginal cysts via an episiotomy and the clinical signs resolved. Histological examination confirmed that the cysts were of urogenital origin. This is believed to be the first report of vaginal cysts causing faecal tenesmus in the dog.
Animals↗
KCl cotransport activity in light versus dense transferrin receptor-positive sickle reticulocytes.
A subset of sickle cells becomes K(+)-depleted and dehydrated before or soon after leaving the bone marrow. These young cells may be identified in blood as transferrin receptor-positive (TfR+) dense reticulocytes. KCl cotransport, which is normally active in young erythroid cells with a maximum at pH 6.8, is a candidate pathway for K+ depletion of sickle reticulocytes. In this investigation, KCl cotransport activity was evaluated in young, TfR+ cells which had become dense in vivo and in age-matched cells which had retained normal hydration. Sickle erythrocytes were first separated into three primary density fractions, with care taken to preserve the in vivo hydration state. After normalization of intracellular hemoglobin concentration with nystatin, the cells were incubated at 37 degrees C for 20 min at pH 6.8 and 7.4. Before and after incubation, each primary fraction was separated into four secondary density fractions. The percentage of TfR+ cells in each secondary fraction was measured and a density distribution for TfR+ cells was determined for each primary fraction before and after incubation. The density shift during incubation was a measure of KCl cotransport. TfR+ cells from the denser primary fractions II and III had significantly more density shift than TfR+ cells from the light fraction I. Although the shifts were larger at low pH, differences between primary fractions were also observed at pH 7.4. These data indicate that the cells which become dense quickly in vivo have more KCl cotransport activity than those which remain light in vivo, and support this pathway as a primary mechanism for dehydration of young sickle cells.
Anemia, Sickle Cell↗
Phasic insulin dependent diabetes mellitus: manifestations and cellular mechanisms.
Explore the source record for details and available documents.
Chromosome Mapping↗
Feline dysautonomia in group-housed cats.
Explore the source record for details and available documents.
Animals↗