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Biomedical subjects

T Smith

Publications and source records attributed to T Smith.

At least 559 records · Page 31Linked to original sources
PubMed1991

Quantitative measurement of faecal blood loss: comparison of radioisotopic and chemical analyses.

Blood loss in faeces was assessed by three different methods in five patients with recurrent iron deficiency. In short term (12 day) studies chemical analysis of complete stool collections for haemderived porphyrins (HemoQuant) gave results closely correlated with those obtained by measuring stool loss of 51Cr-labelled red blood cells. Whole body counting for 59Fe was relatively insensitive to small blood losses but allowed losses to be followed up over longer periods. Chemical analysis of faecal porphyrins thus provides a satisfactory alternative to radioisotopic techniques in short term quantitation of faecal blood loss, while longer term whole body counting of 59Fe may still be appropriate in a few patients for the detection and quantification of intermittent blood losses.

Adult↗
PubMed1991

Reduction in the incidence of acute bronchitis by an oral Haemophilus influenzae vaccine in patients with chronic bronchitis in the highlands of Papua New Guinea.

Following the administration of a standardized questionnaire, 62 adult patients with chronic bronchitis were enrolled into a double-blind controlled trial of an oral killed Haemophilus influenzae vaccine in the highlands of Papua New Guinea. A 3-day course of vaccine or placebo was given monthly for 3 consecutive months. Participants were monitored weekly over 12 months for acute exacerbations; early morning sputum specimens were collected monthly and during acute exacerbations. Density of colonization by H. influenzae and H. parainfluenzae was determined by standard quantitative and semiquantitative techniques, and the latter method (quadrant score) was used to determine the density of growth of pneumococci. A total of 30 patients received vaccine and 32 placebo. The incidence rate of acute bronchitis in the vaccine group (0.011 episodes/person-weeks) was significantly lower than that in the placebo group (0.021 episodes/person-weeks), but there was no difference between the two groups in the incidence rates of more severe disease. Vaccine efficacy was maximal at times of peak incidence of disease. There was no evidence of a decline in vaccine efficacy for acute bronchitis over the 12-month follow-up period. The number of viable H. influenzae in the sputum declined in both vaccine and placebo groups over the 12-month follow-up period. The average concentration of H. influenzae in the vaccine group fell below that in the placebo group within 1 to 2 months after first immunization and remained so for 12 months, although the difference between the two groups narrowed during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1991

Abdominal wall actinomycosis associated with use of an intrauterine device: a case report.

The association between pelvic actinomycosis and the use of intrauterine devices is well established. However, abdominal wall actinomycosis without clinical involvement of the pelvic organs has been reported only once in the literature. The authors present a second case, which occurred in a 24-year-old woman who was using a copper 7 intrauterine device.

Abdominal Muscles↗
PubMed1991

Enzyme mechanisms in the metabolism of nitrosamines.

Many nitrosamines are metabolized by cytochromes P450, one of which (P450IIE1) has received much attention because of its role in the metabolic activation of N-nitrosodimethylamine. This enzyme exists in man, rat, mouse, hamster and other animal species. It is inducible by fasting, diabetes and exposure to ethanol, acetone, isoniazid, benzene and other chemicals. P450IIE1 is responsible for the low Km form of N-nitrosodimethylamine demethylase and is the major enzyme catalysing the metabolic activation of this carcinogen. In addition, P450IIE1 is the most active P450 species known in the metabolism of N-nitrosoethylmethylamine and N-nitrosopyrrolidine. In the metabolism of N-nitrosobutylmethylamine, P450IIE1 preferentially oxidizes the methyl group over the butyl group, whereas P450IIB1 efficiently oxidizes both the methyl and butyl groups. P450IIB1 also catalyses the alpha-oxygenation of both the pentyl and methyl groups of N-nitrosopentylmethylamine, forming pentaldehyde and formaldehyde at a rate ratio of 2:1, as well as oxygenation at other carbons of the pentyl group. Many nitrosamines are effectively activated in nonhepatic target tissues. The metabolism of 4-(N-nitroso-methylamino)-1-(3-pyridyl)-1-butanone in lung and nasal microsomes is discussed.

Animals↗
PubMed1991

Accidents, poisoning and violence as a cause of hospital admissions in children.

A study has been carried out to assess the pattern of child admissions to Tayside Hospitals as a result of accidents, poisoning and violence (hereafter referred to simply as 'accidents') during 1989, and to determine if any major changes have taken place since 1980. The length of stay resulting from each class of accident was used as an approximate indicator of severity and the consumption of Health Service resources. In 1989, 1,388 of Tayside's 70,609 children were admitted to hospital as a result of accidents. With a total of 4,140 days spent in hospital, an average of 11.3 beds are constantly occupied by child accident victims (not including the long-term disabled). Falls resulted in the largest number of admissions to hospital, with poisoning, and having been accidentally struck by persons or objects, in second and third place. Analysis of bed usage, however, revealed a different pattern. While falls remained the biggest consumer of bed days, these were now followed by motor vehicle traffic accidents (MVTAs) and scalds. The average length of stay for MVTAs and scalds was 9.1 and 9.0 days respectively compared with an average of 2.8 days for all types of accident. Poisoning and scalds showed a remarkable age dependence with 81% of children admitted for poisoning or suspected poisoning being in the 1-3 year age group, and 63% admitted for scalds under the age of two.

Accidental Falls↗
PubMed1991

Mid-upper-arm circumference (MUAC) in relation to other indices of nutritional status in Papua New Guinea.

Mid-upper-arm circumference (MUAC) measurements made during the 1982-1983 National Nutrition Survey were compared to other anthropometrics indices of nutritional status and it was found that MUAC was a poor predictor of the other measures. Whilst this does not necessarily imply that MUAC cannot be used to identify children at high risk it is one of a number of considerations which limit its utility in Papua New Guinea. Low MUAC measurements were particularly common in middle-altitude zones, where malnutrition is more frequent; this suggests that MUAC may be more useful in identifying malnourished groups than individuals.

Age Factors↗
PubMed1990

CUG as a mutant start codon for cat-86 and xylE in Bacillus subtilis.

The cat-86 gene specifies chloramphenicol acetyltransferase (CAT). The cat-86 start codon is UUG, although related genes have AUG as the start codon. Changing the start codon to AUG increased expression of cat-86 by 36% in Bacillus subtilis. Changing the start codon to GUG and CUG decreased expression to 65% and 30%, respectively, of the level obtained when AUG was the start codon. CUG has not been previously shown to function as a start codon in B. subtilis. N-terminal sequencing of purified CAT protein specified by the CUG mutant, revealed that CUG was indeed the start codon and specified methionine. The gene xylE, which specifies catechol 2,3-dioxygenase, has AUG as its start codon. Changing the start codon for xylE to CUG decreased expression by 98%. However, when the ribosome-binding site sequence for xylE was optimized and the spacing between it and the start codon was increased to 8 nucleotides, xylE activity increased to 13% of the activity observed for AUG. CUG did not function efficiently as a start codon for cat-86 in Escherichia coli. These data suggest conditions under which CUG can function, with modest efficiency, as a start codon in B. subtilis.

Bacillus subtilis↗
PubMed1990

Analysis of the int-1, int-2, c-myc, and neu oncogenes in human breast carcinomas.

We have examined the DNA obtained from 100 primary breast carcinomas for oncogene markers which might have predictive value for poor prognosis. Ninety-six of the tumors were analyzed for the presence of restriction fragment length polymorphisms (RFLPs) previously identified in the int-2 gene. An 8.4-kilobase BamHI fragment and a 3.9-kilobase PstI fragment specific for the int-2 gene, in the absence of other restriction fragments, was found in 17 of 50 (34%) lymph node-negative patients and in 27 of 44 (61%) lymph node-positive patients. This combination of int-2 RFLPs (8.4/3.9) was found in a significantly different proportion (P = 0.02) of patients with greater than 3 positive lymph nodes compared to patients with fewer positive lymph nodes, suggesting that these RFLPs may be valuable for distinguishing among node-negative patients for chemotherapy. In contrast, the observed low frequency of int-1, int-2, neu, and c-myc amplification limited their usefulness as clinical predictors of disease recurrence.

Breast Neoplasms↗
PubMed1990

Medical audit.

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Feedback↗
PubMed1990

Esorubicin (deoxydoxorubicin) has low grade activity in malignant melanoma. Results of an Eastern Cooperative Oncology Group study (EST 2685).

In this phase II trial, twenty patients with advanced, measurable melanoma from ECOG institutions were treated with esorubicin 30 mg/m2 iv every three weeks. Doses were escalated or reduced based on nadir counts. The dose limiting toxicity was leukopenia with no significant thrombocytopenia or anemia. Other toxicities were mild. One patient had skin necrosis with extravasation. Two patients with soft tissue disease had partial remissions and were treated with 9 and 17 courses. One patient was stable for 8 courses. No cardiac toxicity was seen in three patients receiving more than 150 mg/m2. The response rate was 10% (90% CI = 2 to 30%). Low level activity was seen, but it is unlikely that this drug has sufficient activity to warrant further development in melanoma.

Adult↗