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Biomedical subjects

D H Smith

Publications and source records attributed to D H Smith.

At least 271 records · Page 15Linked to original sources
PubMed1983

Genetic analysis of the folding pathway for the tail spike protein of phage P22.

Temperature-sensitive mutations in the gene encoding the trimeric tail spike protein of phage P22 interfere with protein maturation at 39 degrees C. We show here that temperature-sensitive mutations at many sites block the folding pathway prior to accumulation of the partially folded protrimer intermediate. Temperature-shift experiments indicate that at least some of the mutants accumulate an earlier intermediate in the folding pathway. Immunoprecipitation experiments suggest that the conformation of the isolated temperature-sensitive polypeptide chains is closer to that of the unfolded chain than to that of the mature spike formed at permissive temperature. The sites of these mutations probably represent amino acid sequences that play key roles during the folding of the tail spike polypeptide chain but are not important in the mature protein.

Genes↗
PubMed1983

In vitro fertilization and the surgeon.

The recent successes with in vitro fertilization and embryo transfer in the management of female infertility have ramifications outside of gynaecology. Procedures of a general surgical nature in young women should be carried out with possible future oocyte aspiration via the laparoscope kept in mind.

Embryo Transfer↗
PubMed1983

A comparison of intraamniotic prostaglandin and extraamniotic prostaglandin gel for midtrimester termination of pregnancy.

A comparison between midtrimester abortion induced by the intraamniotic injection of prostaglandin F2 alpha and abortion induced by prostaglandin F2 alpha in Tylose gel administered extraamniotically was made in a group of 40 patients. The induction-abortion interval in the extraamniotic group was 12.1 hours which was significantly shorter (P less than 0.001) than the intraamniotic group (27.6 hours). The placenta was expelled completely more often and there were no cervical lacerations using the extraamniotic method whereas 2 patients required repair of cervical lacerations after intraamniotic prostaglandin. Extraamniotic administration of prostaglandin F2 alpha in Tylose gel is recommended as a safe and more effective method for inducing midtrimester abortion than intraamniotic prostaglandin.

Abortion, Induced↗
PubMed1983

Lactoperoxidase and Iodo-Gen-catalyzed iodination labels inner and outer membrane proteins of Haemophilus influenzae.

Both inner and outer membrane proteins of Haemophilus influenzae type b were labeled by iodination procedures believed to be specific for exposed surface proteins only. It is suggested that this is due to specific properties of the outer membrane of H. influenzae and that use of these procedures with other gram-negative bacteria be evaluated carefully.

Carbon Radioisotopes↗
PubMed1983

Eosinophilia in D-penicillamine therapy.

Cross-sectional and longitudinal studies have been carried out to determine the incidence and clinical significance of eosinophilia in patients taking penicillamine for rheumatoid arthritis. In a cross-sectional study of 204 patients eosinophilia was found with equal frequency during treatment with penicillamine, gold, and nonsteroidal anti-inflammatory drugs. A longitudinal study of 89 patients treated with penicillamine showed no consistent relationship between eosinophilia and adverse reactions to the drug. It is concluded that routine monitoring of eosinophil counts is unlikely to be of value in the management of patients taking penicillamine.

Anti-Inflammatory Agents↗
PubMed1983

Reduced pregnancy rates in AID women with unsuspected ovulatory failure.

A review over five years of 232 patients attending an artificial insemination by donor (AID) clinic was undertaken in order to detect abnormalities in ovulation patterns. Ovulation was determined by luteal phase progesterone estimations. Unexpected anovulation was found in 36% of the patients attending despite an apparently normal previous menstrual history and investigations. This group consisted of 22% who were anovulatory from commencement in the programme and 14% who became anovulatory during treatment. The cumulative pregnancy rates at 15 months for these two groups were lower (73% and 55%) than that for the remaining patients who ovulated normally (90%). A proportion (16%) of the latter group were receiving clomiphene therapy for anovulation recognized before entering the programme. The lower pregnancy rate could not be related to other factors influencing conception and occurred in spite of clomiphene therapy. These results should assist in advising patients on their chances of conception, preventing early discouragement but not encouraging long term insemination which may not improve the pregnancy rate.

Anovulation↗
PubMed1983

Virilizing hilus (Leydig) cell tumor of the ovary: the challenge of an accurate preoperative diagnosis.

A 73-year-old woman developed temporal balding and "hoarseness" over a 3-year interval. Investigation including extensive endocrinologic screening, abdominal computed tomography scanning, pelvic ultrasonography, iodocholesterol (NP-59) adrenal scanning, and selective retrograde venous sampling revealed only an elevated serum testosterone level without localization of the source. At laparotomy a 2.0 cm left ovary was found to contain a hilus (Leydig) cell tumor. The testosterone level in a blood sample from the left ovarian vein obtained intraoperatively was 9000 ng/dl, whereas a blood sample from the right ovarian vein contained 213 ng/dl. One week later her peripheral blood testosterone level was normal (8 ng/dl). The records of six other patients with ovarian hilus cell tumors were reviewed from the Memorial Hospital Registry (from 1959 to 1982). All tumors were small (ovaries were 2 to 4 cm in diameter) and benign. The average patient's age was 63 years (range: 57 to 73 years). Only three of the seven patients in our series were first seen with virilization; the tumors in the remaining four patients were found incidentally. Ovarian hilus cell tumors are rare and are difficult to diagnose, but surgeons and endocrinologists should think of this tumor when they investigate older female patients with virilization. Careful intraoperative examination of even normal-appearing ovaries is imperative, particularly if no adrenal disease is found.

Aged↗
PubMed1983

Viral haemorrhagic fever surveillance in Kenya, 1980-1981.

Following two cases of Marburg virus disease in Kenya in 1980, viral haemorrhagic fever surveillance was undertaken in western Kenya. Over a 21-month period investigations, including virus isolation attempts, patient and contact serology, visits to areas where suspected cases occurred, interviewing family members and neighbours of suspected cases and following up any additional illnesses in these areas, were carried out. During the study two cases were found that were likely to have been Ebola haemorrhagic fever based on rising antibody titres or positive serology in contacts. Diagnoses of hepatitis A, hepatitis B, malaria, bacterial septicaemia or other causes were arrived at in 24 cases. No diagnosis could be made in 26 instances. 741 human sera were tested for antibodies against Marburg, Ebola, Congo haemorrhagic fever, Rift Valley fever or Lassa fever viruses by indirect fluorescence. Eight sera were positive for Ebola virus antibodies, all of which were from suspected cases or contacts of suspected cases. Two sera were antibody positive to Congo virus and one had antibodies against Rift Valley fever virus. No Marburg or Lassa virus antibodies were detected.

Adolescent↗
PubMed1983

Effects of clomiphene administration on ovarian function as measured by estradiol and ultrasound.

The growth and rupture of the graafian follicle were studied in 23 women during 40 cycles (20 spontaneous, 20 clomiphene-induced) by the estimation of plasma estradiol levels and ultrasound scan. The mean preovulatory estradiol peak level was 415 pg/ml in spontaneous cycles and 626 pg/ml after clomiphene administration when one follicle was present. Ultrasonic examination revealed the presence of more than one developing follicle in one of 20 spontaneous cycles, and in 11 of 20 cycles after clomiphene treatment. The determination of follicle size and number by ultrasound scan during ovulation induction by the routinely used starting dosage of clomiphene has revealed a previously unrecognized incidence of ovarian overstimulation, and may allow the rationalization of ovulation induction regimens.

Clomiphene↗
PubMed1982

Do pili play a role in pathogenicity of Haemophilus influenzae type B?

Surface components of Haemophilus influenzae type b (Hib) responsible for mucosal adherence were identified through assay of in-vitro attachment to human buccal epithelial cells (EC). Among many Hib strains from cerebrospinal fluid, blood, or the nasopharynx (NP), two isolates from NP were found to be exceptionally adherent. Adherence correlated with agglutination of human red blood cells (RBC). The adherent strains displayed pili, not previously described for Hib or other encapsulated H. influenzae. Moreover, highly adherent, piliated subpopulations of bacteria could be selected from any strain, but were lost upon subculture. Thus, the potential to express pili may be general for Hib and may aid the NP colonisation which precedes systemic invasion by this organism. Piliation was correlated with the amount of an outer membrane protein with a molecular weight of about 20,000 daltons, which had proved to be immunogenic in an 8-month-old child.

Adhesiveness↗
PubMed1982

Prevalence and disease spectrum in a new focus of visceral leishmaniasis in Kenya.

A cross-sectional community study was conducted in the village of Kivaa in Machakos District, Kenya, to determine the prevalence and disease spectrum of visceral leishmaniasis. The disease was first diagnosed in 1978. Demographic data was collected from 50 households comprising 374 individuals. Clinical examination, laboratory investigations and leishmanin skin tests were performed. The results showed that in spite of the presence of a susceptible population, visceral leishmaniasis occurred with a low prevalence in Kivaa as evidenced by the small number of individuals with active disease (0.30%), a low leishmanin positivity rate (7.2%) and the presence of leishmanial antibodies in only 3.7% of the population. The infection affected individuals in homesteads with or without nearby termite hills. Leishmanial antibodies and leishmanin positivity were found among asymptomatic household contacts of patients as well as in isolated individuals in non-infected homesteads. These findings suggest the existence of a spectrum of disease ranging from asymptomatic to self-healing to severe clinical illness. Furthermore, there was significant clustering of leishmanin reactors in the households of patients. The aetiology of this striking focality of visceral leishmaniasis remains obscure. Possible explanations are discussed.

Adolescent↗
PubMed1982

Some social and psychological factors related to suicide in primitive societies: a cross-cultural comparative study.

Using a sample of primitive and peasant societies from the Human Relations Area Files, this paper examines some of the social and psychological factors related to suicide prevalence. Although the sample is small, the results are quite striking, and a multivariate analysis accounts for about 70 percent of the variance in suicide prevalence. In these data, suicide prevalence is quite consistently high where (a) the society involved is of the stable agricultural type (vs. hunting-gathering type), (b) the society customarily expects either very restrained or very open expression of the emotions (vs. more moderate expression of the emotions), and (c) the society customarily places a great deal of importance on individual pride and shame (vs. little or no emphasis on such matters).

Cross-Cultural Comparison↗
PubMed1982

Human antibody response to individual outer membrane proteins of Haemophilus influenzae type b.

To evaluate the potential of outer membrane proteins of Haemophilus influenzae as a vaccine, sera from 11 healthy persons and from 23 patients convalescing from disease caused by Haemophilus influenzae type b were assayed for antibodies to individual outer membrane proteins of a single type b isolate, strain Eag, by a gel radioimmunoassay. All 23 patients, ranging in age from 2 months to 62 years, with 17 patients being 24 months or less, had antibodies to some of these proteins in their sera (range, antibodies to 4 to 17 proteins per patient). Although the intensity and spectrum of the response varied, all patients had antibodies to one particular outer membrane protein and 19 patients had antibodies to another, with those patients 5 years and older having antibodies to more proteins than did infants (<==24 months). In the two cases examined, convalescent sera had greater amounts and broader spectra of antibodies than did acute sera. In addition, 10 of 11 healthy subjects not known to have had systemic H. influenzae disease also had antibodies to individual outer membrane proteins, with older children having greater amounts than did their younger siblings and with children showing a different spectrum of response than that for adults. Thus, antibodies to outer membrane proteins are commonly found in humans. Also, these results and those demonstrating that hyperimmune rabbit antisera to strain Eag reacted with each of five type b substrains possessing some different outer membrane proteins indicate considerable cross-reactivity among these proteins. These results encourage continued consideration of outer membrane proteins in a vaccine.

Adolescent↗
PubMed1982

Serum gamma-glutamyltransferase and alkaline phosphatase in rheumatoid arthritis.

Serum gamma-glutamyltransferase (GGT) and alkaline phosphatase (AP) were assayed in 98 consecutive patients with rheumatoid arthritis. Twenty-three patients had increased GGT activities and 45 an increased AP activity. Twelve patients showed an increase in both enzyme activities and AP isoenzyme studies were performed on seven of this group. In three subjects an increase in the bone isoenzyme was observed and in three others the increase in activity was attributed to the liver isoenzyme. The remaining patient, who probably suffered from coexistent primary biliary cirrhosis, showed an increase in both bone and liver isoenzymes. The liver involvement, suggested by the alkaline phosphatase isoenzyme results, was largely confirmed by the butanol extraction of GGT. The changes in these enzymes in this small series could not be related definitely to drug therapy. It is concluded that though increases in GGT and AP are common in rheumatoid arthritis, this does not necessarily indicate hepatic involvement. Further isoenzyme studies are needed to define the extent to which organs other than the liver bring about increases in these serum enzymes in rheumatoid disease.

Adult↗