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Biomedical subjects

D H Smith

Publications and source records attributed to D H Smith.

At least 235 records · Page 13Linked to original sources
PubMed1987

Effect of dietary fat and lactation status on insulin binding to bovine milk fat globule membranes.

Lactating cows were used to examine the relationship between lactation status and insulin binding to milk fat globule membranes. Variables evaluated were daily milk yield, stage of lactation, breed, age, lactation number, daily milk fat and protein yields, milk fat and protein percentages, breeding status, body weight, body weight.75, and mammary health. Milk yield was correlated with insulin binding and accounted for 20% of the binding variability. No other variables were related to insulin binding. Insulin binding to milk fat globule membranes increased with supplemental dietary fat up to 4% added fat in the diet dry matter. Milk fat globule membranes may provide a useful model for assessing insulin receptor regulation in the mammary gland. Sources of variation in insulin binding to mammary membranes remain to be identified.

Animals↗
PubMed1986

Vaccines consisting of periodate-cleaved oligosaccharides from the capsule of Haemophilus influenzae type b coupled to a protein carrier: structural and temporal requirements for priming in the human infant.

Reducing oligosaccharides from the Haemophilus influenzae type b capsular polymer (PRP) coupled by reductive amination to diphtheria toxoids (DTd) had been shown to elicit potentially protective serum anti-PRP antibodies (Ab) in infants too young for an adequate response to PRP vaccine. Here we report that cleavage of PRP with periodate gives antigenic oligosaccharides that couple with high efficiency. DTd-coupled saccharides of mean length eight or 20 repeat units (Dpo8 and Dpo20, respectively) were tested for immunogenicity in young adults (single injection) and in infants 9 to 15 mo old who received a sequence of primary (1 degree) and secondary (2 degrees) injections. Both vaccines consistently induced high anti-PRP Ab responses in adults. In infants, Dpo8 elicited only modest anti-PRP responses, whereas Dpo20 gave consistently high titers; post-2 degrees responses were higher when the interval between 1 degree and 2 degrees injections was 6 to 14 wk than with an interval of 2 to 4 wk. Thus with this type of immunogen, priming responses in infancy has more stringent structural requirements than does triggering responses in adults, and the priming appears to maximize more slowly than the Ab level.

Adult↗
PubMed1986

A Parkinson-like neurologic deficit in primates is caused by a novel 4-substituted piperidine.

A neurologic deficit characterized by hypokinesia, postural flexion, and to a lesser extent, rigidity, tremor and myoclonus, has been observed in cynomolgus monkeys following administration of 1-methyl-4-(1-methylpyrrol-2-yl)-4-piperidinol (MMPP), a novel 4-substituted piperidine. The syndrome, similar to that described for 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), developed within 3-7 days after oral or i.v. dosing, and was accompanied by lesions in the substantia nigra. The behavioral syndrome was seen to a lesser extent in dogs but not in rats. MMPP contains a hydroxyl group on the 4-position of the pyridine ring; the corresponding dehydration product was inactive.

Animals↗
PubMed1986

BIONET: national computer resource for molecular biology.

This paper describes briefly the BIONET National Computer Resource for Molecular Biology. This presentation is intended as information for scientists in molecular biology and related disciplines who require access to computational methods for sequence analysis. We describe the goals, and the service and research opportunities offered to the community by BIONET, the relationship of BIONET to other national and regional resources, our recent efforts toward distribution of the resource to BIONET Satellites, and procedures for investigators to gain access to the Resource.

Amino Acid Sequence↗
PubMed1986

Massive eosinophilia in rheumatoid arthritis: report of four cases.

We report four cases of massive eosinophilia (greater than 1.5 X 10(9)/l) a phenomenon uncommon in rheumatoid arthritis. In two patients it preceded therapy with second line anti-rheumatic drugs. The others developed it during therapy with penicillamine and gold, though neither had an adverse reaction. It appears there are two patterns of massive eosinophilia in RA; one is related to the disease process the other to drug therapy. It does not necessarily predict adverse drug reactions nor preclude treatment with anti-rheumatic therapy.

Adult↗
PubMed1986

A review of second-look laparotomy for ovarian cancer.

One hundred twenty-seven patients underwent second-look laparotomies from July 1969 to June 1982. To be included in this report they must have met the following criteria: a documented ovarian neoplasm; previous surgery; adequate chemotherapy for cessation if no disease was found; and no X-ray, chemical, or clinical evidence of disease including an exam under anesthesia. Forty-one percent had residual disease at second-look laparotomy. The original stage and the percentage of tumor debulked at initial surgery were inversely related to the likelihood of finding residual disease. Age, histologic type and grade, and type of chemotherapy did not show a significant relationship with the likelihood of disease persisting. Recurrent tumor was subsequently detected in 16% of patients who had been found to be free of disease at second-look laparotomy. Of thirty stage III and IV patients treated with combinations containing cis-platinum, 10 (33%) had recurrences. This rate of recurrence was significantly greater than the 17.6% recurrence rate in 17 patients with Stage III and IV disease whose chemotherapy consisted of single alkylating agents or with combinations without cis-platinum. Twenty patients underwent a third-look laparotomy after completion of additional chemotherapy. Nine were found to have no residual disease. Two of the nine (22%) subsequently had recurrence of disease. Three of the eleven patients with persistent disease at the time of a third-look laparotomy underwent a fourth-look laparotomy. All were found free of disease and none have recurred. Six (55%) of those with persistent disease at the third-look laparotomy have died despite continued therapy. The ability to successfully treat some patients with persistent disease continues to be a justification for the use of a second-look laparotomy. However, the high rate of recurrence after cessation of treatment following the finding of no residual disease raises the question of whether it is appropriate to discontinue all therapy at this time.

Alkylating Agents↗
PubMed1986

Characterization of insulin binding to bovine liver and mammary microsomes.

Bovine liver and mammary gland (MG) appear metabolically independent of insulin, yet the specificity and kinetics of 125I-insulin (125I-INS) binding to bovine liver and MG microsomes (MIC) indicate the presence of insulin receptors in MIC from both tissues. The insulin receptors from bovine liver (Kd = 7.6 X 10(-10) M) and MG (Kd = 9.6 X 10(-11) M) were similar to each other and to other insulin receptors in their binding affinities and pH optima. Perturbation of rat liver and bovine MG MIC by phospholipase or NaCl treatment increased 125I-INS binding to the membranes, suggesting exposure of cryptic insulin receptors. Different responses in 125I-INS binding to membrane perturbation suggest differences between rat and bovine membranes.

Animals↗
PubMed1986

Timing of multiple ovulations in the ewe after treatment with FSH or PMSG with and without GnRH.

Ovulation rate, median time to first ovulation, median time of all ovulations and median time from first to last ovulation were studied by repeated laparoscopy in Merino ewes. Treatments with FSH or PMSG significantly affected ovulation rate (8.4 +/- 0.81 and 7.3 +/- 1.21 respectively, P less than 0.05) and in median time of all ovulations (60 and 54 h respectively after progestagen sponge removal, P less than 0.05). Differences in the median time to first ovulation (60 and 48 h) and median time from first to last ovulation (6 and 6 h) for the respective treatments were not significant. The synchrony of ovulation after both treatments was adversely affected by (1) the occurrence of premature ovulations before the onset of superovulation, (2) variability in the time of commencement of superovulation, and (3) variability in the time from first to last ovulation. Administration of GnRH synchronized the timing of ovulation with both gonadotrophin treatments. This synchrony was due to a reduction in the period during which superovulation began and in the interval from first to last ovulation. The median time of all ovulations was significantly less with FSH + GnRH than with PMSG + GnRH (45 and 48 h after progestagen sponge removal, respectively, P less than 0.05). Administration of GnRH at 16, 20 or 24 h after progestagen sponge removal significantly affected all traits examined except ovulation rate. Administration at 20 and 24 h produced an equally good synchrony of ovulation which was better than that obtained at 16 h. We suggest that the use of GnRH in embryo collection programmes appears justified and is likely to improve embryo yields due to improved rates of fertilization.

Animals↗
PubMed1985

Structure and chromosomal localization of the human lymphotoxin gene.

We have isolated, sequenced, and determined the chromosomal localization of the gene encoding human lymphotoxin (LT). The single copy gene was isolated from a human genomic library using a 32P-labeled 116 bp synthetic DNA fragment whose sequence was based on the NH2-terminal amino acid sequence of LT. The gene spans 3 kb of DNA and is interrupted by three intervening sequences. The LT gene is located on human chromosome 6, as determined by Southern blot analysis of human-murine hybrid DNA. Putative transcriptional control regions and areas of homology with the promoters of interferon and other genes are identified.

Amino Acid Sequence↗
PubMed1985

Nalbuphine.

Nalbuphine is a potent analgesic with a low side effect and dependence profile in animals and man. Nalbuphine is distinguished from other agonist/antagonist analgesics in having greater antagonist activity and fewer behavioral effects at analgesic doses than pentazocine, butorphanol or buprenorphine. At equi-analgesic doses, nalbuphine is quantitatively similar to nalorphine in regard to its large ratio of antagonist to analgetic activity. Clinical studies have confirmed this balance of strong antagonist to analgesic activity. Nalbuphine has been shown to effectively antagonize the respiratory depressant activity of narcotic analgesics while concomitantly adding to their analgetic responses. Unlike nalorphine or pentazocine, nalbuphine produces few overt behavioral or autonomic effects in animals at doses over 300 times its analgesic range. These findings are confirmed by clinical results which show that nalbuphine produces few psychotomimetic effects, even at elevated dose levels, in contrast to nalorphine or pentazocine. Nalbuphine produces limited respiratory depression in animals and in man. Significant cardiovascular effects have not been found. Nalbuphine was found to produce significantly less inhibition of gastrointestinal activity than any of the clinically useful narcotic or agonist/antagonist analgesics tested in animals. Nalbuphine's analgetic effects are reversed by naloxone doses similar to those which reverse nalorphine's agonist effects. Results in this and other tests suggest that nalbuphine is primarily a kappa-agonist/mu-antagonist analgesic. Unlike pentazocine or buprenorphine, nalbuphine does not suppress the narcotic abstinence syndrome in partly-withdrawn morphine-dependent animals or man. Rather, due to nalbuphine's strong antagonist activity, analgesic-range doses of nalbuphine severely exacerbate the withdrawal syndrome in partly-withdrawn mice, monkeys and humans. Nalbuphine also precipitates a strong abstinence response in non-withdrawn morphine-dependent animals and man. In post-addict humans, analgesic-range doses of nalbuphine are perceived as minimally morphine-like, but higher doses are judged to be progressively more nalorphine-like (i.e. dysphoric), which further limits nalbuphine's abuse potential in drug-seeking individuals. Primary dependence studies have demonstrated that physical dependence is possible at high dose levels that produce marked side effects. Other studies show that dependence is unlikely to be of significance within nalbuphine's usual analgesic range. Six-month studies in patients with chronic pain have confirmed that analgesic tolerance or physical dependence is uncommon.(ABSTRACT TRUNCATED AT 400 WORDS)

Analgesics↗
PubMed1985

Parental pressure for tonsillectomy: attitudes and knowledge of parents accompanying their children to an ear, nose and throat clinic.

The parents of 120 children referred for possible tonsillectomy to an ear, nose and throat (ENT) surgeon were studied. There was no evidence that a desire for the operation fulfilled 'psychological needs' for parents or was a means of coping with a 'deviant' child. Parents favouring tonsillectomy were less well informed, and the educational role of the general practitioner in reducing the small number of those who inappropriately pressurize medical services is highlighted.

Adolescent↗
PubMed1985

Preparation and antiarthritic and analgesic activity of 4,5-diaryl-2-(substituted thio)-1H-imidazoles and their sulfoxides and sulfones.

A series of 4,5-diaryl-2-(substituted thio)-1H-imidazoles was synthesized and evaluated as antiinflammatory and analgesic agents in the rat adjuvant induced arthritis assay and the mouse phenyl-p-benzoquinone writhing (PQW) assay. Several analogues were found to be more potent than phenylbutazone and indomethacin. Structure-activity relationships are discussed. One of the compounds, 4,5-bis(4-fluorophenyl)-2-[(1,1,2,2-tetrafluoroethyl)-sulfonyl]-1H- imidazole (8d, tiflamizole), was found to be 8 times as potent as indomethacin in the rat adjuvant induced arthritis assay and is presently undergoing clinical trial as an antiarthritic drug.

Analgesia↗