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Biomedical subjects

A H Smith

Publications and source records attributed to A H Smith.

At least 163 records · Page 9Linked to original sources
PubMed1982

Some biochemical findings during pregnancy and after delivery in relation to mood change.

Thirty-four women who had vaginal deliveries of live infants completed behavioural ratings and supplied blood and 24-hour urine samples on three occasions during pregnancy and on three occasions after delivery. Approximately one third of the women indicated a distinct upswing in mood between Days 2 and 4 following delivery. These "positive mood change' subjects showed changes in urinary cyclic AMP (adenosine 3'5' cyclic monophosphate), plasma cyclic AMP, whole blood cell cyclic AMP, whole blood cell ATP (adenosine triphosphate), haematocrit and urinary 11 OHCS (11-hydroxycortisol steroids) following delivery which were different from those observed in the rest of the subjects and comparable with the biochemical changes described during upswings in mood in short-cycle manic-depressive subjects. There was also an indication that the women showing this upswing in mood following delivery were distinct in some respects on both behavioural ratings and biochemical findings during pregnancy.

11-Hydroxycorticosteroids↗
PubMed1982

Changes in eggshell conductance after transfer of hens from an altitude of 3,800 to 1,200 m.

Hens acclimated to an altitude of 3,800 m (PB 480 Torr) were transferred to 1,200 m (PB 657 Torr). Eggs were collected before departure and daily after the transfer so that changes in eggshell conductance could be studied. Over the next 2 mo eggshell conductance increased 30%, presumably to compensate for the 37% reduction (from 657 to 480 Torr) in gas diffusivity at the lower altitude. Measurements of shell thickness and number of pores in the shell allow one to calculate that most of the change in total pore area occurred by an increase in cross-sectional area of individual pores.

Adaptation, Physiological↗
PubMed1982

Relationship between vitamin A and lung cancer.

Current evidence indicates that vitamin A and carotene (a precursor) protect against cancer at many sites. The relationship with lung cancer has been studied more extensively than other cancer sites by retrospective and prospective dietary surveys and serum studies, most of which support an inverse association between vitamin A or carotene and lung cancer. Further retrospective serum studies should include family members of patients and controls for determination of what family differences are present that could not be attributed to the effect of cancer on the patients. Nutritional studies are also warranted for identification of determinants of serum vitamin A and carotene and for comparisons of dietary intake and serum levels between populations with different cancer incidence.

Diet↗
PubMed1981

Cholecystectomy and cancer of the large bowel.

A matched case control study was conducted in order to determine the association between previous cholecystectomy and the development of large bowel cancer. One hundred and sixty men and 145 women presenting with large bowel cancer were studied. One control was selected for each case matched according to age, sex and date of admission. The medical records for each patient in the study were reviewed for evidence of previous cholecystectomy. No association was found among male patients, but for women an estimate of relative risk of 2.7 was obtained for patients who had had previous cholecystectomy. This association was largely a consequence of the fact that 10 female patients with rectal cancer had had a previous cholecystectomy compared with only of their controls. It is possible that carcinogenic breakdown products of bile salts are most concentrated in the distal portion of the large bowel, but it is difficult to explain why the association should be confined to women only.

Cholecystectomy↗
PubMed1981

Vanadium: a possible aetiological factor in manic depressive illness.

The effect of Vitamin C in manic-depressive psychosis was assessed by a double-blind, placebo controlled, crossover trial. Both manic and depressed patients were significantly better following a single 3 g dose of Vitamin C than following a placebo. Preliminary results of a double-blind, crossover comparison of normal vanadium intake with reduced intake in manic and depressed subjects are reported. Both manic and depressed patients were significantly better on reduced intake. These results are in keeping with the suggestion that vanadium may be an aetiological factor in manic depressive illness.

Ascorbic Acid↗
PubMed1981

A case-control study of bladder cancer in the United States rubber and tyre industry.

A case-control study of bladder cancer was conducted in five United States rubber and tyre companies to determine if there were high-risk jobs and work areas within the industry. The study included 220 male cases of bladder cancer, of whom 107 were identified from hospital record reviews and 113 from death certificates. Each case was matched individually with two industry controls by sex, race, year of birth, and company. One control was matched additionally by year of hire and duration of employment. Comparisons of cases and controls not matched by year of hire and age of hire showed no differences for those variables, which suggests that age and calendar period of first exposure to the industry were not risk determinants. When the work histories of both cases and controls were contrasted it was found that cases were more likely than controls to have worked in milling (odds ratio (OR) = 1.91) and calender operation (OR = 2.21) jobs. The relative risk estimates for milling and calender operation both exhibited linear trends of increase with duration of exposure. Milling and calender operation jobs entail potential exposures to volatilised reaction products from heated rubber stock. A better understanding of aetiological associations with job type will require more detailed characterisation of the work environment with regard to the sources and levels of aromatic amines and other suspected bladder carcinogens.

Adult↗
PubMed1981

The reliability and validity of two assessment scales in the elderly mentally handicapped.

The Clifton Assessment Schedule and the Shortened Stockton Rating Scale were administered to 38 elderly, mentally handicapped patients. Inter-rater reliability was high and the CAS was found to be a useful measure of cognitive ability. The tests measure different features of patients, but both correlated significantly with estimated levels of independence.

Aged↗
PubMed1981

Excess lung cancer risk in a synthetic chemicals plant.

A standardized mortality ratio of 1.49 for respiratory system cancer (42 observed deaths versus 28.2 expected, p less than 0.01) was observed among a cohort of 4806 males employed at a synthetic chemicals plant since its startup in 1942. Upon review of pathologic material, the excess was found to be limited to adenocarcinoma and large cell undifferentiated lung cancer. Many of the workers had been exposed to vinyl chloride, as well as to chlorinated solvents, poly(vinyl chloride) (PVC) dust, acrylates and acrylonitrile. To evaluate the association between lung cancer and occupational chemical exposures, detailed work histories for each cohort member were combined with exposure ratings for each of 19 chemicals for each job for each calendar year since 1942. A serially additive expected dose model was then constructed which compared the doses of the chemicals observed for the lung cancer cases to the doses expected based on subcohorts without lung cancer individually matched to the cases. PVC dust appeared to be the most likely etiologic agent (p = 0.037). Time trends of PVC dust exposure indicated a potential latent period of 5-16 years before death.

Adenocarcinoma↗
PubMed1981

Serum vitamin A (retinol) and cancer incidence in Evans County, Georgia.

A total community sample of 3,102 individuals from Evans County, Georgia, was followed for 12-14 years. During this period, 129 documented new cases of cancer were ascertained from medical records and death certificates. Cases were considered for inclusion only if documented at least 12 months after subjects were inducted into the cohort study. Cases were classified as definite, probable, and possible by strict criteria. Blood samples were drawn at the beginning of the study in 1960-62 and sera were frozen. Serum vitamin A (retinol) levels were measured in 1976 on the stored sera of 85 cancer patients and for 174 age-, race-, and sex-matched controls. Retinol estimations were performed by a fluorometric method after alumina column separation. Experiments conducted to simulate the exposure to light, thawing, and refreezing that sera may have undergone during the 14-16 years of storage showed retinol to be quite stable in response to these possible insults. As compared to controls, persons that eventually developed cancer had significantly lower mean serum retinol levels at least 12 months before the cancer diagnosis. The association was in the same direction for all 4 race-sex groups, although stronger overall for males than females, and was consistent for the various cancer sites and cell types. Both matched and regression residual analyses were used to control for the confounding variables considered: age, race, sex, obesity, social class, and smoking.

Age Factors↗
PubMed1980

An examination of the relationship between fluoridation of water and cancer mortality in 20 large US cities.

A comparison of mortality of 10 US cities with fluoridated water supplies compared with 10 non-fluoridated cities has been used as evidence that artificial fluoridation of drinking water causes cancer and has been widely publicised in New Zealand. Several deficiencies are noted in the analysis used by the investigators in this study and it is shown that appropriate analysis of the data from these cities yields additional evidence for the safety of fluoridation. This finding agrees with that from previous examinations of the same data in spite of the fact that they included an error in the mortality report from one city.

Aged↗