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Biomedical subjects

R S Levine

Publications and source records attributed to R S Levine.

At least 19 recordsLinked to original sources
PubMed1992

Experience, skill and knowledge gained by newly qualified dentists during their first year of general practice.

This study was commissioned by the Department of Health in 1988 for the assessment of the preparation of newly qualified dentists for general practice and the effect of the Vocational Training Schemes on their development. Newly qualified dentists working either as VTS trainees or associates were assessed in three ways. During the third and the twelfth months of practice they were asked to keep a one-week clinical diary record. They were also asked to complete a questionnaire to give a subjective assessment of their skill and knowledge related to general practice. Similar questionnaires were completed by their trainers or principals in order to provide an objective assessment. An indication of the volume of treatment they provided was also obtained from DPB records. The results showed that associates saw more patients and provided more treatment than VTS trainees during their first year. The difference between the two groups was greater at 3 months than at 12 months; however, wide variations were found, especially in the VTS group. The results from the questionnaires suggest that, with the exception of practice administration, oral surgery, orthodontics, anaesthesia and sedation, the undergraduate course provides adequate preparation for the initial demands of general practice. However, initially both groups were judged to be unprepared for independent practice. The results suggest that during the first year of practice the support and guidance of a more experienced colleague is essential, together with the provision of adequate and varied clinical experience.

Clinical Clerkship↗
PubMed1992

Global estimates of acute pesticide morbidity and mortality.

Mathematical models have projected increasing numbers of pesticide poisoning throughout the world, rising from 500,000 cases/yr in 1972 to 25,000,000 cases/yr in a 1990 estimate. Among 148 outbreaks (excluding Bhopal and three probable epidemics of pesticide-related suicide) reported between 1951-90, the known number of cases was 24,731 with 1065 deaths (4.3% case fatality); these are probably underestimates. Among the known outbreaks, the most commonly identified agents were organophosphates (58), carbamates (23), chlorinated hydrocarbons (23), and organic mercurials (11). Food was the most common vehicle of exposure in these epidemics (83 outbreaks), followed by skin contact (26), multiple types of exposure (22), and respiratory exposure (16). Two countries, the United States and Thailand, accounted for more than half the reports. Both the mathematical models and the outbreak investigations support the need for continuing investigation and improved surveillance throughout the world.

Accidents↗
PubMed1992

Pregnancy and breast cancer: a possible explanation for the negative association.

We propose that pregnancy protects against breast cancer, in part, because it results in excretion of lipophilic carcinogens by the mother through the fetal fat and vernix caseosa. We review several lines of epidemiologic and toxicologic evidence in support of this idea, including concordances between known or suspected risk factors for cancer of the female breast and known or suspected risk factors for increased body burdens of lipophilic carcinogens.

Breast Neoplasms↗
PubMed1991

Diet and the risk of in situ cervical cancer among white women in the United States.

A case-control study of women with incident in situ and invasive cervical cancer was conducted during 1982-83 in five US areas reporting to the Comprehensive Cancer Patient Data System: Birmingham, AL; Chicago, IL; Denver, CO; Miami, FL; and Philadelphia, PA. Controls were selected by random-digit dialing and matched to invasive cases on age, race, and telephone exchange. Of the white non-Hispanic in situ cases and controls identified, 229 (78 percent) and 502 (74 percent) were successfully interviewed. Diet was assessed by asking about the usual adult frequency of consumption of 75 food items and the use of vitamin supplements. Included were the major sources of the four micronutrients postulated to reduce the risk of cervical cancer: carotenoids, vitamin A, vitamin C, and folate. Weak inverse associations between risk of in situ disease and intake of carotenoids, vitamin C, folate, fruit, and vegetables/fruits were noted but, with further analysis, these seemed attributable to residual confounding by the multiple lifestyle-related risk factors for this disease and possibly to selection bias. Vitamin A and vegetable intake were unrelated to risk. Dark yellow-orange vegetable consumption and duration of multivitamin use were each strongly related to reduced risk of in situ disease (P for trend = 0.02 and 0.002, respectively) and need to be evaluated in other studies. The absence of persuasive protective effects for the four micronutrients and the similar findings from our analysis of invasive cervical cancer do not concur with other epidemiologic studies and suggest that the role of diet and nutrition in the etiology of cervical cancer is not yet resolved.

Adult↗
PubMed1991

Fluoride and caries prevention: 1. Scientific rationale.

In order to achieve the greatest clinical benefit from the use of fluoride, we must understand its mechanism of action, so that fluoride can be given at the right time, by the best route, at the optimum dosage and in the most suitable form. The first article in this two-part series reviews the scientific rationale behind the use of fluoride. Part 2 will illustrate fluoride therapy in practical terms, by examining eight clinical cases.

Dental Caries↗
PubMed1990

Risk factors for in situ cervical cancer: results from a case-control study.

A case-control study of 293 patients with in situ cervical cancer and 801 community controls was conducted between 1982 and 1984 in five geographic areas in the United States. Relative risk (RR) was elevated among women reporting multiple sexual partners (RR for greater than or equal to 5 partners = 5.0), a history of an abnormal Papanicolaou smear (RR = 5.0), interval since last Papanicolaou smear (RR for greater than or equal to 10-year interval versus 0- to 2-year interval = 4.1), use of oral contraceptives (RR for greater than or equal to 10 years use = 1.4), a history of nonspecific genital infection (RR = 2.6), and smoking (RR for current smokers = 1.9). Risk was low among diaphragm users (RR for greater than 2 years use = 0.5). Neither age at first coitus nor number of births was predictive of risk of in situ disease. Comparisons between this analysis and risk factors previously identified for invasive cervical cancer in this same study indicate that the risk factors were quite similar.

Adult↗
PubMed1990

Diet and the risk of invasive cervical cancer among white women in the United States.

A case-control study of incident invasive cervical cancer was conducted in Birmingham, Alabama; Chicago, Illinois; Denver, Colorado; Miami, Florida; and Philadelphia, Pennsylvania, during 1982-1983. Controls were selected by random-digit dialing and were matched to cases by age, race, and telephone exchange. Of the white, non-Hispanic cases and controls identified, 271 (73%) and 502 (74%), respectively, were successfully interviewed. Diet was assessed by asking about the usual adult frequency of consumption of 75 food items and the use of vitamin supplements. Included were the major sources of the four micronutrients believed to reduce the risk of cervical cancer: carotenoids, vitamin A, vitamin C, and folate. Women in the highest quartiles of intake of each of these micronutrients had adjusted relative risks of invasive squamous cell cervical cancer comparable to those of women in the lowest quartiles, although their micronutrient intake was estimated to be 3-4 times as high. Risk was not affected by increased consumption of vegetables, dark green vegetables, dark yellow-orange vegetables, fruits, or legumes, or by high intake of the basic food groups. These generally negative findings stand in contrast to findings in previous epidemiologic studies, and the discrepancy is not readily explained by bias, uncontrolled confounding, or inadequate power. The question of the role of diet and nutrition in the etiology of cervical cancer is not yet resolved.

Adult↗
PubMed1990

Historical patterns of pesticide epidemiology research from 1945 to 1988.

Review of four questions faced by pesticide epidemiologists from 1945 to 1988 shows a transition from maternal to paternal concerns in Agent Orange reproductive research, greater emphasis on accidents than suicide in acute-injury research, and an apparent focus away from diagnoses specific to women in both occupational mortality and cancer research. Further study of such historical research trends might assist both causal inference and the ethical evaluation of epidemiologic research.

Epidemiology↗
PubMed1989

A photographically recorded assessment of enamel hypoplasia in fluoridated and non-fluoridated areas in England.

This study assesses the effect on enamel formation of the use of fluoride toothpaste in a fluoridated area. The prevalence of enamel hypoplasia in 251 9-10-year-old children born and raised in a fluoridated city (Birmingham) was compared with that in 319 similar children born and raised in a non-fluoridated city (Leeds). Observer bias was eliminated by the use of a new photographic technique, enabling colour slides of both groups to be assessed together in a random order. Scoring was done using both the Jackson-Al-Alousi (J-A) index, which is designed to record nonspecific hypoplasias and the Tooth Surface Index of Fluorosis (TSIF). Both were compared to the results from conventional clinical recording using the J-A index. The results showed that the photographic method was highly reproducible and more sensitive than conventional recording and showed a higher level of mild fluorosis in the fluoridated area. However, no evidence of an increase in the higher grades of fluorosis was found. It is concluded that the use of fluoride toothpaste by young children in fluoridated areas is unlikely to produce aesthetically unacceptable levels of enamel fluorosis.

Child↗
PubMed1989

Photographic technique for the recording of children's teeth for signs of enamel mottling.

A photographic method is described for recording children's teeth in large numbers on location. The essential features of the dental study were that the photography should be consistent, accurate, and fast, since the subjects were to be photographed at a rate of 45 children per hour. Details are given on how this was achieved including the technique and equipment used.

Child↗
PubMed1987

Epidemiology of cervical cancer by cell type.

A multicenter case-control study of 481 invasive cervical cancer patients and 801 population controls enabled comparison of risk factors for squamous cell tumors (n = 418), adenosquamous cancers (n = 23), and adenocarcinomas (n = 40). The epidemiology of the squamous cell tumors resembled that found in other studies, with the major risk factors being absence of Pap smear screening (relative risk = 3.6 to 4.8 for those not screened within 5 yr), multiple sexual partners (relative risk = 2.9 for over ten partners), and history of genital infections or sores (relative risk = 2.3). Although based on small numbers, adenosquamous tumors appeared to share some of these risk factors, notably number of sexual partners, years since last Pap smear, and level of education. Adenocarcinomas were not similarly affected, although sexual practices were marginally predictive. Obesity increased the risk of adenocarcinoma, but no other similarities to endometrial adenocarcinoma were observed. Smoking was a significant predictor of squamous cell tumors but did not affect adenocarcinomas. Extended use of oral contraceptives was a risk factor for all tumor types, especially adenocarcinoma, and a familial tendency to cervical cancer was also observed for all cell types.

Adenocarcinoma↗
PubMed1987

Genetic variance of weight and length in infant twins.

A population-based cohort of 166 twin pairs (67 monozygotic and 99 dizygotic) born at the Jackson Memorial Hospital/University of Miami Medical Center, from July 1, 1976 to December 31, 1980 was identified. Body weight and length were measured at 14 days and at one, three, six, nine, and 12 months of age. Statistically significant genetic variance was found for both body weight and length at each data point. Heritability for body weight increased from 0.28 at 14 days to 0.64 at one year. Corresponding values for body length were 0.16 and 0.48.

Body Height↗
PubMed1987

Comparison of computer-assisted learning with tutorial teaching in a group of first-year dental students.

Two identical groups of first-year dental students were instructed in the pathology of dental caries and periodontitis using computer-assisted learning (CAL) or tutorial teaching (TT). A cross-over arrangement, in which the first group was taught about dental caries by CAL and periodontitis by TT and the second group in the reverse order, allowed comparison of the two methods. The comparison included a knowledge test and completion of a questionnaire. CAL and TT were equally effective as far as acquisition of knowledge was concerned. Students felt pressurized with CAL and had problems with note-taking. They liked a teacher to be present. Nevertheless, CAL was an acceptable method of instruction and was more economical, in terms of staff involvement, than TT.

Computer-Assisted Instruction↗
PubMed1987

Sexual and reproductive risk factors for invasive squamous cell cervical cancer.

A case-control study of 418 women with invasive squamous cell cervical cancer and 704 population controls enabled evaluation of risk factors for this relatively rare cancer. Consistent with an infectious etiology was a pronounced effect of multiple sexual partners, with those reporting 10 or more partners being at a significant threefold excess risk. Early first intercourse also was associated with some residual effect on risk, although the relationship was not linear, nor the explanation readily apparent. Those with multiple births were at significantly elevated risks, even after adjustment for sexual parameters. Menstrual and hygiene factors, including use of tampons, vaginal deodorants, and douching products, were not consistently related to risk. Histories of specific infections involving the genital tract were poor predictors of risk, since few women provided positive responses, but those with nonspecific diseases were at a significant twofold excess risk.

Adult↗