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Biomedical subjects

A Phillips

Publications and source records attributed to A Phillips.

At least 163 records · Page 9Linked to original sources
PubMed1988

Effects of photoperiod, the pineal gland and the gonads on agonistic behavior in female golden hamsters (Mesocricetus auratus).

Four studies were conducted to determine the role of photoperiod, the pineal gland and the gonads in the regulation of intrasex agonistic behavior in female hamsters. In the first experiment animals maintained under Long or Short photoperiods were tested in same or opposite photoperiod pairs. Under both testing conditions, Short-day animals tended to exhibit a higher ratio of offensive to defensive behaviors, which was due primarily to a reduced level of defensive behavior in Short-day groups. In the second experiment animals under Long and Short photoperiods were tested following sham surgery or pinealectomy. Short-day sham animals exhibited the highest level of offensive behavior, the lowest level of defensive behaviors and the highest offensive/defensive ratio; pinealectomy eliminated the Short-day advantage. In the third experiment, Long-day animals receiving exogenous melatonin showed a higher level of agonistic responding than animals injected with control vehicle, indicating that Short-day effects are probably mediated through pineal melatonin. The results of the last experiment in which ovariectomy to Long-day animals was not able to mimic the effects of photoperiod or exogenous melatonin indicated that the photoperiod effects on aggression are probably not mediated through the gonads.

Aggression↗
PubMed1988

25- to 30-nm virus particle associated with a hospital outbreak of acute gastroenteritis with evidence for airborne transmission.

Between November 1 and 22, 1985, an outbreak of acute, nonbacterial gastroenteritis occurred in a 600-bed hospital in Toronto, Ontario, Canada. Illness in 635 of 2,379 (27%) staff was characterized by fatigue, nausea, diarrhea, and vomiting and had a median duration of 24-48 hours. The finding of virus-like particles measuring 25-30 nm in six stool specimens and low rates of seroresponse to Norwalk virus (3/39) and Snow Mountain agent (1/6) suggest that a Norwalk-like virus was responsible for the outbreak. The outbreak was of abrupt onset and high incidence, affecting 79 people in a single day. No common food or water exposure could be identified. The attack rate was greatest (69%) for staff who had worked in the Emergency Room. Of 100 patients and their companions who visited the Emergency Room on November 11-12 for unrelated problems, 33 (33%) developed gastroenteritis 24-48 hours after their visit, versus 0 of 18 who visited the Emergency Room on November 8 (p less than 0.001). An analysis of housekeepers who worked at least once during the period from November 9-13, which included those who became ill during the period of November 9-14, showed that the risk of becoming ill was four times greater for those who visited or walked through the Emergency Room than for those who did not (p = 0.028). These data are consistent with the possibility of the airborne spread of a virus.

Adult↗
PubMed1988

Plasma bupivacaine concentrations during caudal analgesia and ilioinguinal-iliohypogastric nerve block in children.

Plasma bupivacaine concentrations were measured in 27 children aged 3-7 years who received one of two analgesic regimens for herniotomy or orchidopexy. Analgesia was provided either by caudal epidural bupivacaine 0.2% 2 mg/kg (n = 14) or by ilioinguinal-iliohypogastric nerve block with bupivacaine 0.5% 1.25 mg/kg (n = 13). Mean (SD) peak venous bupivacaine concentrations were 0.57 (0.17) microgram/ml and 0.79 (0.38) microgram/ml respectively. Time to peak plasma concentrations were 29.6 (7.9) and 22.3 (10.9) minutes respectively. These concentrations are well below the potentially toxic level of 4.0 micrograms/ml, but suggest that uptake of bupivacaine is more rapid after ilioinguinal-iliohypogastric nerve block than during caudal analgesia.

Anesthesia, Caudal↗
PubMed1988

Intertypic genomic rearrangements of poliovirus strains in vaccinees.

In vivo intertypic RNA recombination has previously been observed in excreted type 3 poliovirus isolates from a normal asymptomatic primary vaccinee. This study examines isolates from additional primary vaccinees to determine whether intertypic recombination is a general occurrence in excreted polioviruses. T1 RNase oligonucleotide finger-printing and limited dideoxy primer extension RNA sequencing demonstrated no evidence of intertypic recombination among type 1 or type 2 excreted strains. However, vaccinees excreting type 3 strains for long periods of time eventually produced recombinant strains involving either type 1 or type 2 poliovirus. Moreover, a characteristic time course of appearance of excreted type 3 intertypic recombinant polioviruses was established. Type 3/type 1 and type 3/type 2 recombinant strains appeared at Days 10-11 with a single crossover site in the gene for nonstructural protein 2C. Type 3/type 2/type 3 complex recombinant strains with an additional crossover site in the polymerase gene replaced type 3/type 2 strains at approximately Day 28. A significant portion of the genome of the type 3 Sabin vaccine strain is thus replaced during long-term excretion by vaccinees, and the appearance of some genomic arrangements coincided with a base deletion at the 3' terminus.

Feces↗
PubMed1988

A competitive enzyme-linked immunosorbent assay for alpha 1-acid glycoprotein in serum and urine samples.

In this solid-phase competitive enzyme-linked immunosorbent assay for alpha 1-acid glycoprotein in serum or urine, antiserum to human alpha 1-acid glycoprotein is incubated with solid-phase-bound alpha 1-acid glycoprotein in the presence of standard or sample. Incubation with second antibody labeled with alkaline phosphatase then follows, before development with substrate. Results obtained correlate well with a fluorescent assay involving the dye Auramine O (r = 0.953) and with radial immunodiffusion (r = 0.921). The present assay covers the range 0.2 to 5 mg/L and 16 samples take 2.5 h to complete. This assay is useful for measuring concentrations of alpha 1-acid glycoprotein in serum and also in urine, for which other assay methods are not sufficiently sensitive.

Arthritis, Rheumatoid↗
PubMed1987

Feasibility of contact surveys in general practice.

Surveys to evaluate risk factors for disease in the general population are popular with health authorities for assessing the effectiveness of their preventive measures. A contact survey of the lifestyles of 2000 randomly selected patients aged 25-64 was conducted in five general practices over 18 months; the medical records of the patients selected were tagged, and when the patients first visited the surgery they were given a questionnaire by the receptionists, which they completed in the waiting room. Over the 18 months at least 1400 of these patients visited the practices, of whom 1106 (55%) completed a questionnaire and 20 refused to do so; 896 (81%) completed it within one year. Information on the patients who were not surveyed was obtained by sending the questionnaire by post and by audit of medical records. The population surveyed on contact with the surgeries contained a higher proportion of young women, and possibly a higher proportion of patients from social classes IIIM-V, than the other patients. No important or consistent bias towards unhealthy patients at high risk was identified in the contact survey. A one year contact survey of a random, tagged sample is feasible in estimating the risk factors in a population and may be the method of choice in general practice because of its low cost and adaptability.

Adult↗
PubMed1987

Anaphylactoid and anti-ovulatory activities of LHRH antagonists in rats.

Studies were conducted with LHRH antagonists examining the relationship of structure to anaphylactoid-like activity and the relationship of anaphylactoid-like activity to anti-ovulatory activity in rats. Substitution of basic amino acids appeared to enhance the anaphylactoid-like activity of these peptides but other complex structural characteristics may also be involved. Anaphylactoid and anti-ovulatory activities were clearly independent and potent LHRH antagonists with minimal anaphylactoid-like activity were identified.

Amino Acid Sequence↗
PubMed1987

Sensitivity differences in reproductive/endocrine organs to chronically administered LHRH agonists in female rats.

The acute and chronic effects of two LHRH agonists on reproductive endocrine target organs were examined in female rats. Animals were injected twice daily with [(ImBzl)-D-His6,Pro9-NEt]LHRH (histrelin) or [D-Trp6,Pro9-NEt]LHRH for 1, 3, 5, 7, 11 or 28 days at 1, 10, 100 or 1000 micrograms/kg/day beginning in the luteal phase. The responses observed with the two agonists were similar. An initial stimulatory phase was observed on the first day of treatment with substantial increases in serum LH and progesterone levels. A significant diminution of hormone response was seen by day 3. Only 1000 micrograms/kg abolished the pituitary LH response at later treatment periods. Estrous cyclicity, ovarian and uterine weight, and progesterone and estradiol levels were inhibited in a time and dose dependent manner. The results demonstrate target organ sensitivity differences. In contrast to the relatively high doses needed to inhibit the pituitary response and decrease ovarian weight, doses as low as 1 microgram/kg were sufficient to decrease uterine weight. If these findings extrapolate to humans, it may be that conditions in which the desired therapeutic action is suppression of uterine tissue, may be treated with lower doses of LHRH agonists than conditions requiring complete gonadal suppression.

Adrenal Glands↗
PubMed1987

Recombination between the factor VIII gene and the DXS52 locus gives the most probable genetic order as centromere-fra(X)-DXS15-DXS52-F8C-telomere.

The linkage relationship between the factor VIII gene (F8C) and the DXS52 locus was examined in 8 families. Two recombinations were identified in 35 informative meioses (Zmax = 5.67; theta = 0.05), one in a family with hemophilia A, the other in a family with the fra(X) syndrome. Based on the latter recombination, the most probable order of loci was determined to be centromere-fra(X)-DXS15-DXS52-F8C-telomere. When these data are added to those reported previously the most probable genetic distance between F8C and DXS52 is 3 cM (Z = 14.62). Identification of these and other recombinations suggests that the use of DXS52 as a genetic marker for carrier detection and prenatal diagnosis of hemophilia A has an error rate between 3-5%.

Chromosome Fragility↗
PubMed1987

A comparison of the potencies and activities of progestogens used in contraceptives.

The potencies and activities of six progestational agents, norethindrone, levonorgestrel, desogestrel, medroxyprogesterone acetate (MPA), progesterone (P) and norgestimate have been evaluated using standard laboratory bioassays. The endocrine activities measured are those most closely related to the clinically important actions of contraceptives. Relative potencies varied with parameter measured, route of administration and species showing clearly that each progestogen is a distinct pharmacological entity. The order of potency using oral administration for either ovulation inhibition or endometrial stimulation in rabbits was desogestrel greater than levonorgestrel greater than MPA greater than norgestimate greater than norethindrone. Levonorgestrel was more androgenic than desogestrel, and P, norethindrone, norgestimate and MPA were essentially devoid of androgen activity. This profile demonstrates clear differences in the potencies and activities of these progestogens and in their selectivity for target organs.

Androgens↗
PubMed1987

Conservation in vivo of protease cleavage sites in antigenic sites of poliovirus.

Polioviruses possess three major antigenic sites which have been located chemically and structurally on the particle. One of these sites, designated site 1, is strongly immunodominant for serotype 3, but highly immunorecessive for type 1. We report that monoclonal antibodies directed against site 1 of type 1 poliovirus may be isolated by an altered route of immunization of the donor mice. Site 1 is shown to be highly variable for type 1, but highly conserved for type 3 poliovirus, although the converse would be predicted from their immunodominance. The evidence presented suggests that the antigenic conservation is associated with a strong selective pressure for a proteolytic cleavage site within site 1 of type 3. As proteolytic cleavage results in the loss of the antigenicity of site 1 the presence of the cleavage site in a virus replicating in the gut in the presence of proteases would protect the virus from neutralizing antibodies directed against uncleaved site 1. The conservation of the site in type 3 is thus consistent with the view that site 1 is a significant target of a human as well as a murine immune response against type 3.

Animals↗