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Biomedical subjects

M Gill

Publications and source records attributed to M Gill.

At least 217 records · Page 12Linked to original sources
PubMed1981

Kinetics of large ciliate protozoa in the rumen of cattle given sugar cane diets.

1. Experiments were undertaken to examine the kinetics of large ciliate protozoa in the rumen of cattle on sugar-cane diets. 2. Three Zebu bulls were fed once daily on a diet of sugar cane and wheat bran. The diurnal patterns of volatile fatty acids and ammonia concentrations, and the numbers of protozoa in rumen fluid were determined. The numbers of protozoa reached values of 5 X 10(4)/ml for holotrichs (large ciliates) mainly Isotricha and Dasytricha spp and 4 X 10(5) for smaller protozoa, mainly Entodinia (small ciliates). 3. A method was developed which allowed large ciliate protozoa in rumen fluid to be separated from plant material and bacteria and concentrated in a relatively uncontaminated form. Analysis of these protozoa indicated that 1.8 X 10(5) large ciliates contained 1 mg nitrogen and approximately 32 mg dry matter. 4. A labelled preparation consisting mainly of large ciliates (principally Isotricha spp.) was obtained by incubating isolated protozoa in rumen fluid (free of plant materials) containing [14C-methyl]choline and then isolating them by sedimentation and differential centrifugation. 5. A portion of the preparation containing labelled protozoa was incubated in vitro with rumen fluid to determine the turnover of 14C-labelled metabolites. There was no apparent dilution of the label in the protozoa over a 22 h period. 6. A major portion of the preparation containing labelled protozoa was returned to the rumen of each of the donor cattle as a single injection. The specific radioactivity in the large protozoa (microCi/mg N) was monitored frequently for over 30 h, and thereafter daily for a further 12 d. The kinetics of tracer dilution were analyzed to give estimates of the size of the pool of these large ciliates in the rumen (24-46 g N), and of their apparent rate of turnover. 7. In contrast to the slow turnover of the large ciliates, the rate of turnover of the rumen fluid pool (approximately 54 1), estimated from the rate of dilution of polyethylene glycol, was considerably faster. Large ciliates were therefore selectively retained within the rumen.

Ammonia↗
PubMed1979

The metabolism of methionine in silage-fed sheep.

1. L-[U-14C]methionine was used to study methionine metabolism in sheep fed on untreated silage, silage treated with formaldehyde and untreated silage plus intraperitoneal infusion of L-methionine. 2. Over-all the values ranged from 0.43 to 0.86 mmol/h for methionine turnover rate, from 13.3 to 19.9 for the percentage of methionine oxidized to carbon dioxide and from 245 to 1089 mumol for methionine pool size.

Animal Feed↗
PubMed1978

[Renewal of noradrenaline in different zones of the central nervous system of inbred mice strains and their recombinants].

A good correlation exists between the learning capacity and norepinephrine metabolism in the neocortex of C57 and Balb inbred Mice strains, as well as their F1 hybrids and seven recombinant inbred strains derived from their cross. The animals with a better learning performance are characterised by low levels of norepinephrine, as well as a slow metabolic rate of this neurotransmitter in the cortex. Such a correlation has not been found to exist in the other cerebral regions studied.

Animals↗
PubMed1976

Effect of long photoperiod on the maturation of ovary of the catfish, Mystus tengara (Ham.)

A study has been made of the effect of photoperiodism on the ovarian maturation of fresh water teleost, Mystus tengara (Ham.). The magnitude of ovarian recrudescence is more during maturing virgin phase as compared to during immature virgin and preparatory virgin phases in long photoperiod (14 hours/day) treated fish. Thus, the response of the ovary to long photoperiod increases with the approach of natural spawning period. The mature eggs are more in long photoperiod treated fish than in controls exposed to 12 hours/day photoperiod. In long photoperiod treated fish, prespawning period is reduced considerably. During spawning and post-spawning periods, the ovaries are refractory, since long photoperiod is ineffective in maintaining gravid ovaries beyond spawning period and the ovarian regression during post spawning period sets in regardless of nature of photoperiod treatment.

Animals↗
PubMed1976

Effects of acute morphine administration on the catecholamine metabolism of three strains of mice.

Inbred mouse strains exhibit differences in motor activity and brain catecholamine metabolism after acute morphine injection. The two strains C57BL/6J and Balb/cJ, which increased motor activity after morphine present also an increased noradrenaline turnover in the pons medulla, whereas no difference were found in the DBA/2J strain whose motor activity was unchanged. A correlation seems to exist between motor activity and the noradrenaline metabolism in the brain stem.

Animals↗
PubMedDate not supplied

Motor activity effects in female Fischer 344 rats exposed to isopropanol for 90 days.

In a previous subchronic neurotoxicity study, increases in motor activity were observed for female rats after 9 and 13 weeks of exposure to 5000 ppm of isopropanol vapor. The present study was conducted to evaluate the reproducibility of these effects and, if reproducible, to assess the potential for reversibility following cessation of exposure. Two groups, each containing 30 female Fischer 344 rats, were exposed to concentrations of zero (control) and 5000 ppm of isopropanol vapor for 6 h per day, 5 days per week. Fifteen of the animals in the control and 5000 ppm groups were exposed for 9 weeks (designated as the 9-week subgroup), while the other 15 animals in each group were exposed for 13 weeks (designated as the 13-week subgroup). Motor activity was assessed for both subgroups prior to exposure and following 4, 7 and 9 weeks of exposure. Motor activity was also measured for rats in the 13-week subgroup following 11 and 13 weeks of exposure. These motor activity measurements were made 18-20 h following the end of the last exposure for that week. In addition, to evaluate the reversibility of motor activity effects, measurements were made on three occasions during the week following the final exposure for rats in both the 9-week and 13-week subgroups and weekly thereafter for five additional weeks for rats in the 13-week subgroup. Increases in cumulative test session motor activity counts were observed following 4, 7 and 9 weeks of exposure for rats in the 9-week subgroup. Increases in cumulative test session motor activity counts were also observed following 4, 7, 9, 11 and 13 weeks of exposure for rats in the 13-week subgroup. Reversibility of this effect was observed for rats in the 9-week subgroup within 2 days following the last exposure. Reversibility was also noted for rats in the 13-week subgroup but not until Study Week 15 (2 weeks following the last exposure). Minor changes were observed in the shape of the motor activity habituation curves for isopropanol-exposed animals in the 9-week and 13-week subgroups at ca. 50% of the measurement intervals beginning at Study Week 4. While most of these statistical changes were observed in conjunction with increases in cumulative test session motor activity, some were observed following time points where recovery of the cumulative test session motor activity counts had occurred. No change in the shape of the motor activity habituation curve was observed at 42 days following the last exposure, indicating that complete recovery of motor activity effects had occurred. Thus, repeated exposure of female rats to 5000 ppm of isopropanol produced reversible increases in motor activity.

2-Propanol↗
PubMedDate not supplied

No association between RFLPs at the porphobilinogen deaminase gene and schizophrenia.

An association study of restriction fragment length polymorphisms (RFLPs) in the porphobilinogen deaminase (PBGD) gene and schizophrenia was conducted. RFLPs detected by MspI, PstI, ApaLI and BstNI in intron 1 of the gene were studied in 49 patients and 79 controls. There were no significant differences between the groups in allele frequencies, genotype counts or haplotype distribution.

Adult↗
PubMedDate not supplied

Late onset Alzheimer's disease and apolipoprotein association in the Irish population: relative risk and attributable fraction.

BACKGROUND: Familial and sporadic late onset Alzheimer's disease (LOAD) shows a consistent genetic association with APOE epsilon4. AIMS: To examine the role of APOE in the AD Irish population. METHODS: One hundred and ten Irish LOAD patients and 217 ethnically-matched controls were genotyped for APOE marker as described by Crook et al. Chi square test was used to compare allelic and genotypic frequencies between patients and controls samples. Attributable fractions were calculated as described by Levin. RESULTS: A highly significant association between AD and APOE epsilon4 was observed (chi2=37.9, p=0.0000000, RR=2.18). Further, the influence of APOEepsilon4 seems to follow a dose-dependent manner whereby individuals with the genotype APOEepsilon4/4 have a higher relative risk than those heterozygous for the epsilon4 allele (RR=4.03 and 1.76 respectively). The relative risk and the attributable fraction calculated for APOE epsilon4 are consistent with those reported for other European populations. This places the influence of this locus on AD development in the Irish population between those of the Spanish and New York white populations. CONCLUSION: These findings provide further evidence for the importance of APOE in the development of AD.

Aged↗
PubMedDate not supplied

Low intensity strength training for ambulatory stroke patients.

PURPOSE: To investigate feasibility and effectiveness of an individually-directed, group strength-training programme on knee muscle strength after stroke. METHOD: Ten volunteers (62 +/- 11 years, mean +/- SD), 6 - 12 months after first-ever unilateral stroke, walking independently with or without aids were recruited. Using an A1-B-A2 design, 3 sets of baseline measures were taken at 2 weekly intervals; volunteers then attended twice weekly sessions of low intensity progressive strengthening exercises and were assessed after each series of 8 sessions to a maximum of 24 sessions; post training, measures were repeated after 4 - 6 weeks. Measures included isometric and concentric knee extensor muscle strength and 10 m walking velocity. RESULTS: Strength of knee extensor muscles was improved after training (ANOVA, p < 0.05). On cessation of training, isometric strength increased by 58 +/- 19% and concentric strength at 30 degrees /s by 51 +/- 14%; walking velocity quickened from 0.47 +/- 0.06 m x s-1 to 0.57 +/- 0.08 m x s-1 (t = -3.31, p < 0.01). These gains were maintained 4 - 6 weeks after completion of training. CONCLUSIONS: These findings support the use of low intensity strength training after stroke and confirm published evidence. It was feasible for one therapist to deliver the training programmes for 4 - 6 participants at a time; an important feature when resources are limited.

Aged↗
PubMedDate not supplied

No evidence for linkage between schizophrenia and eight microsatellite markers on chromosome 19.

We report the results of a linkage study of eight markers on chromosome 19 in a sample of 24 families multiply affected with schizophrenia and related psychoses. This study forms part of a systematic search of the entire genome using microsatellite markers spaced at 10-20 cM intervals. These data provide no evidence for the presence of a gene of major effect on chromosome 19 under the assumption of genetic homogeneity or heterogeneity. We have attempted to describe the extent to which this region has been excluded and demonstrate that while it is possible to exclude near-dominant and recessive models under the assumption that all families are linked to the same locus, power for exclusion falls away rapidly when incomplete penetrance and heterogeneity are invoked.

Chromosomes, Human, Pair 19↗
PubMedDate not supplied

Constituents of Agaricus xanthodermus Genevier: the first naturally endogenous azo compound and toxic phenolic metabolites.

Extraction of fresh sporophores of the fungus Agaricus xanthodermus yields 4,4'-dihydroxy-azobenzene, phenol, p-quinol, and 4,4'-dihydroxybiphenyl. This is the first report of an azo compound arising endogenously in nature, while phenol, p-quinol and 4,4'-dihydroxybiphenyl have not previously been isolated from higher fungi. Phenol is present in fruitbodies in sufficiently high concentration to account for the toxicity of A. xanthodermus.

Agaricales↗