Simulation in surgical training using freeze dried material

The acquisition of manual dexterity and surgical skills is usually achieved in the operating theatre under supervision. We describe an efficient way of learning intestinal anastomosis procedures with the use of gamma irradiated, lyophilized porcine or bovine tissues together with a purpose designed holding jig. Preliminary evaluation of this method with untrained subjects showed that they were able to improve their performance. Because the tissues are sterile, health hazards are avoided and no special laboratory facilities are required. This approach has promise as an aid to evaluation as well as training.

Space-time clustering of nasopharyngeal carcinoma in Greenland Eskimos

Evidence of epidemicity of nasopharyngeal carcinoma (NPC) was sought in Greenland Inuits, who have a high incidence of this cancer, by examining the births of NPC cases for evidence of clustering in time and space. Births of cases were concentrated in autumn and winter. Fifty-four cases were analysed, and a two-fold excess of clustering within one year was observed, both within single districts and between adjacent districts. This excess was not significant at the 5% level; about 90 cases would have been required to confirm the observed effect at this level of significance. It is suggested that a search for space-time clustering of NPC cases in larger high-risk populations might prove more fruitful.

Virus-associated cancers in Greenland: frequent hepatitis B virus infection but low primary hepatocellular carcinoma incidence

The incidence of primary hepatocellular carcinoma (PHC) in Greenland between 1960 and 1981 was determined and compared with the rate of this disease in Denmark. The annual age and sex rate (per 100,000) was not significantly different (overall, 1.9 vs. 2.2) despite a large difference in the prevalence of hepatitis B surface antigen (HBsAg) and anti-HBs markers of hepatitis. On the basis of a recent report of a very strong risk of PHC among male HBsAg carriers, 4.0 cases of PHC per year were expected in male Eskimos, but only 0.2 cases per year were observed. The incidence rates of other cancers suggested to be virally associated, including nasopharyngeal carcinoma, salivary gland cancer, and carcinoma of the cervix, were all high in Greenland compared to rates for the Danish population, and these high incidence rates are in accord with the markedly higher prevalences in Greenland Eskimos of viruses with which these other cancers have been associated. Thus Greenland Eskimos do not have a high incidence of PHC despite a high prevalence of HBsAg carriers, which suggests that other carcinogenic factors in this environment may be absent or that protective factors are present.

Normal sister chromatid exchange levels in hospital sterilization employees exposed to ethylene oxide

This study was undertaken to determine whether a specific group of hospital workers exposed to ethylene oxide (ETO) in sterilizing areas showed evidence of increased levels of sister chromatid exchange (SCE) formation. SCE frequencies were determined for 14 sterilizer workers and 14 matched controls. Time-weighted average (TWA) and peak ambient levels of ETO were measured in the sterilizing areas. Results indicated that all sterilizer workers were exposed to less than 5 parts per million TWA of ETO and that there were no statistically significant differences in SCE levels between sterilizer workers and controls. Smoking habits did appear to be associated with increased SCE levels. In this particular hospital setting no evidence of genetic effects stemming from employees' exposure to low levels of ETO was found.

Clinical practice plans in family practice residency programs

This paper examines clinical practice plans (CPPs), systems for remunerating physician faculty based on their clinical productivity, in family practice residency programs. A stratified random sample of residency directors responded to a CPP survey. CPPs were found significantly more frequently in residencies (usually operated by universities) either with CPPs in their parent institutions or with high patient volume. Residencies operated by community hospitals were more likely to distribute CPP benefits to faculty based on individual clinical activity, whereas residencies operated by universities were more likely to distribute equal benefits to all faculty or to include academic as well as clinical activities in the benefit determination. While most residency directors felt that CPPs brought financial benefits to a residency and to individual faculty, many directors who did not have CPPs feared that such a plan would create conflicts between patient care and teaching. A case report tracing the evolution of a CPP in one university-administered residency is presented.

Skin cancer in Greenland 1955-1974

During the period from 1955 to 1974, a total of 23 cases of skin cancer in indigenous Greenlanders was diagnosed, 15 in males and eight in females. There were ten basal cell carcinomas, four squamous-cell carcinomas, five malignant melanomas of the skin, and four sarcomas. Eight of the ten basal cell carcinomas were located on the head, half of these on the eyelids. Three of the four squamous-cell carcinomas were found on the lower lip. The number of malignant melanomas in females and the number of remaining, nonmelanotic skin cancers in both males and females were significantly lower than expected if the incidence in the Greenland population had been the same as in Denmark. Since recent investigations seem to indicate that the annual ultraviolet radiation is of almost the same magnitude as in northwest Europe, the low incidence may be due to less skin exposure and/or ethnic factors such as a higher degree of pigmentation. No accumulation of cases within definite geographical areas was found and no occupational clustering was apparent. As regards both squamous-cell carcinomas and malignant melanomas, the degree of metastases and survival indicated that Greenlandic patients sought medical assistance very late.

Epstein-Barr virus in nasopharyngeal and salivary gland carcinomas of Greenland Eskimoes

Biopsy specimens from nasopharyngeal carcinomas (NPC) or salivary-gland carcinomas (SGC) in Greenland Eskimoes were examined for the presence of Epstein-Barr virus (EBV) DNA and sera from the patients were tested for EBV-specific antibody titres. Six out of 7 NPCs and one from an undifferentiated SGG were positive for EBV DNA. The EBV-specific antibody spectra and titres of the patients with NPC or undifferentiated SGG conformed to the results of earlier studies in other high-incidence areas.

Factors related to an effective referral and consultation process

A study of 141 consecutive referrals from family physicians in four clinic sites was undertaken to obtain descriptive characteristics of the referral-consultation process and to identify factors associated with effective outcomes. Consultation reports were returned to referring physicians in 88 percent, 75 percent, and 43 percent of referrals from consultants in community practice, university faculty practice, and university outpatient clinics, respectively. The quality of the consultation reports, as determined by the referring physician's opinion, increased directly with the amount of referral information originally sent to the consultant. The referral-consultation process appears to be functioning well in this site. The data suggest that this process might function even better if referring physicians would personally contact and send letters to consultants.

Lung cancer in Greenland--selected epidemiological, pathological, and clinical aspects

One hundred and seven cases of lung cancer were first diagnosed among indigenous Greenlanders during the 25 years from 1955 to 1979. Compared with the Danish population, relative risk of lung cancer among male Greenlanders increased from 0.4 in 1955-1959 to 1.1 in 1975-1979. Relative risk among women increased from 0.7 to 2.1. The age-adjusted rate for women during the period 1975-1979 is one of the highest on record. This increase in lung-cancer risk followed a sharp rise in the use of cigarettes in the general population. An association with cigarette consumption was also suggested by tumor histology and location. A synergistic role of other risk hazards is possible. Local factors arising from previous tuberculosis involvement may have favored lung cancer development in men. More than 2/3 of the cases of lung cancer diagnosed between 1955 and 1974 were brought to medical attention because of clinical symptoms although most of the population was screened annually or biannually for tuberculosis. Intervention through screening had little impact on the overall very low survival rate.

Inadequate sensitivity of tuberculin tine test for screening employee populations

Tuberculin Tine and Mantoux skin tests were simultaneously applied to opposite arms of 1,065 medical center employees during their usual preemployment and annual health examinations for the purpose of evaluating the Tine test sensitivity. Of 829 skin tests read, 39 (5%) were positive by the Mantoux method. Tine tests were positive in 27 of the 39: a sensitivity of 69% and a false-negative rate of 31%. In view of these results, the tuberculin tine test is not sensitive enough and is not indicated for employee screening programs when finding tuberculosis infection, and not disease, is the primary goal.

Isolated systolic hypertension in Evans county--I. Prevalence and screening considerations

Studies suggest that isolated hypertension involves pathophysiological change different from essential hypertension; while clinical trials of drug treatment of isolated systolic hypertension are underway, little is known of its descriptive epidemiology. This paper reports characteristics of isolated systolic hypertension in biracial Evans County, Georgia, 1967-69. Isolated systolic hypertension was rare below age 40, but the percent prevalence increased greatly at older ages. Defining isolated systolic hypertension as diastole blood pressure (DBP) less than 95 and systolic blood pressure (SBP) greater than 160, age-adjusted percent prevalence at ages 40 and above were 9.6, 10.6, 15.1, and 18.3 for white males, black males, white females, and black females respectively. Percent prevalence declined to 4.8, 6.3, 9.7, and 12.7 in the four race/sex groups when a DBP cutoff of 90 was used. Unlike essential hypertension, percent prevalence of isolated systolic hypertension varied more by sex than by race: it was 60-100% higher in females than in males and only 10--30% higher in blacks than in whites. Percent prevalence of isolated systolic hypertension for the second and third of three BP readings (one clinic visit) increased compared to the first reading, the reverse of what is usually found for essential hypertension. DBP variability was relatively greater than SBP variability and probably accounted for the changes in percent prevalence. These data support clinical studies indicating isolated systolic hypertension is a distinct syndrome. This condition, shown to be a risk factor for death and disease in other studies, was common at older ages and may increasingly become health problem as the population ages.

Lipoprotein and blood pressure changes during weight reduction at Duke's Dietary Rehabilitation Clinic

The influence of a weight-reducing diet among 129 obese patients after only 4 weeks at Duke's Dietary Rehabilitation Clinic is evaluated in its effect on cholesterol, HDL and LDL cholesterol, and on hypertension in combination with and without drugs. The 700-cal diet consists of 60 g protein, 60 g carbohydrates and 25 g invisible fat. After 4 weeks, total cholesterol decreased on the average by 44 mg% and serum triglycerides by 65 mg%. While LDL cholesterol declined by 30 mg% and VLDL cholesterol by 10 mg%, HDL cholesterol showed a small decrease of 7 mg%. Blood pressure levels were normalized in the 63 hypertensive patients. The conclusion is that a very moderate weight loss of only 9-12 kg has profound influences on important risk factors.

Hepatitis B in a medical center

The Employee Health Service of Duke University has been evaluating all employees with known blood product exposures through a standardized protocol since January 1977. All known cases of hepatitis B among employees were also evaluated. During the 40-month period of this report, 1,235 substantiated blood product or body fluid exposures occurred. The blood involved in 155 of the exposures was positive for HBsAg. Of the 155 employees involved in these exposures, 101 were found to be nonimmune to hepatitis B and were followed for at least nine months after exposure. Three (3.0%) developed clinical hepatitis B. An additional 24 employees also developed hepatitis B during this 40-month period, a cumulative incidence of 106.0 per 100,000 employee years. Hepatitis B appears to be a significant occupational hazard for hospital personnel in a tertiary medical center.

Chelatable lead body burden (by calcium-disodium EDTA) and blood lead concentration in man

The cheletable part of lead body burden was measured in 32 workers and seven office workers after an infusion test with CaNa2EDTA. The workers had been exposed to lead at a lead and zinc processing unit for one to three years (mean one year). There was good correlation (r = 0.87) between blood lead and chelatable urinary lead excretion described by the equation y = 0.07 . 10(0.46.x). From this equation it can be predicted that the generally accepted limit value for chelatable urinary lead excretion, 0.42 mumol/mmol CaNa2EDTA administered per 24 hours (3.1 mumol/24 hours or 650 micrograms/24 hours), corresponds to a blood lead concentration (PbB) of 1.7 mumol/l (or 35 micrograms/100 ml), which is lower than the commonly accepted limit value of 2.9 mumol/l (or 60 micrograms/100 ml) for occupationally lead-exposed persons. There was a better correlation between the cheletable lead excretion and the urinary ALA-excretion (r = 0.45; p less than 0.001) than between PbB and the urinary ALA-excretion (r = 0.26; p greater than 0.05).

Breast cancer in Greenland--selected epidemiological, clinical, and histological features

Fifty-seven breast cancers were diagnosed among indigenous Greenlandic women from 1950 to 1974. An additional 22 cases registered between 1975 and 1979 represent a minimum number and were only used as basis for minimum incidence rates. Changes in age-adjusted rate, age-specific incidence pattern, and relative risk were consistent with an upward shift from a population of low risk between 1950 and 1969 to one of intermediate risk from 1970 onward, a finding that relates well to increased urbanization and westernization. The risk of breast cancer in Greenland may be associated with consumption of saturated fats but is seemingly not correlated to total fat intake which has always been on a par with high-risk Danish levels. An association with diet may in reality have been stronger than suggested but weakened by a counterbalancing effect of high fertility, especially in the youngest age groups. Evaluation of histological features and survival did not suggest differences which could favorably compare with findings in white population groups contrary to reported results from the population of Japan, also one of low risk and of mongoloid origin. Further studies should consider dietary intakes, endocrine variations, and breast fluid secretion with special attention to girls at the age of menarche.