Coffee and tea and the risk of recurrent colorectal adenomas

Consumption of coffee has been associated with a reduction in the risk of cancer of the colon, and (less consistently) drinking tea has been associated with a reduction in the risk of rectal cancer. The effect of these beverages on the risk of colorectal adenomas, however, has not been well investigated. We used data from an adenoma prevention trial to investigate these associations. Patients with at least one recent large bowel adenoma were followed with colonoscopy 1 and 4 years after their qualifying examinations. Adenomas detected at the year 4 colonoscopy were used as end points. A food frequency questionnaire was administered at study entry and study completion; average intake over the study period was used to estimate the exposures of interest. There was no apparent association between the intake of regular coffee, decaffeinated coffee, or tea and the risk of recurrent colorectal adenomas. The relative risks and 95% confidence intervals per cup daily were 0.96 (0.87-1.05) for regular coffee, 0.97 (0.84-1.12) for decaffeinated coffee, and 1.02 (0.83-1.25) for tea. These negative findings were present both overall and for adenomas of the right and left large bowel.

Assessment of cellular telephone and other radio frequency exposure for epidemiologic research

Epidemiologists are now embarking on the evaluation of the hypothesis that exposure to radio frequency energy from low-power wireless communication devices, such as portable cellular telephones, causes brain cancer and other adverse health outcomes. Even in the laboratory, exposures from radio frequency sources are difficult to quantify; their measurement in large populations for epidemiologic study is challenging. In this paper, we outline the nature and magnitude of these exposures and discuss the prospects for obtaining useful measures of exposure for epidemiologic research.

Calcium supplementation and rectal mucosal proliferation: a randomized controlled trial

BACKGROUND

Data from studies using rodents suggest that dietary calcium inhibits bile acid-induced mucosal damage and experimental carcinogenesis in the large bowel. However, in humans, the effect of dietary calcium and calcium supplementation on proliferation and carcinogenesis in the large bowel has been unclear.

PURPOSE

To assess the effect of calcium supplementation on rectal mucosal proliferation in humans, we conducted a multicenter, randomized, placebo-controlled, double-blinded trial.

METHODS

Participants were part of a larger multicenter chemoprevention trial; all were at high risk for large-bowel neoplasia, with at least one large-bowel adenoma removed endoscopically within the 3 months before study entry but with no known polyps remaining. Subjects were randomly assigned to receive daily either 3000 mg of calcium carbonate (providing 1200 mg elemental calcium) or an identical-appearing placebo tablet. During a scheduled endoscopy 6-9 months after random assignment (approximately 1 year after the qualifying endoscopy), rectal mucosal samples were obtained from 333 patients (173 assigned to calcium and 160 assigned to placebo). Proliferating cell nuclear antigen (PCNA) labeling indices (LIs) were computed as the measure of proliferation in specimens from 146 patients receiving calcium and 129 patients receiving placebo. Bromodeoxyuridine (BrdU) labeling was used to measure proliferation in a smaller number of specimens (27 calcium-receiving and 31 placebo-receiving participants). For each scorable crypt having at least one labeled cell (or surrounded by crypts with at least one labeled cell), a crypt LI was calculated as the number of labeled cells divided by the total number of crypt cells. Crypt LIs were averaged to produce a participant's average LI.

RESULTS

The overall unadjusted mean PCNA LIs (+/- SE) were similar in the calcium and placebo groups (3.85% +/- 0.08% versus 3.92% +/- 0.08%, respectively, P = .30). The overall unadjusted mean BrdU LIs (+/- SE) were 3.88% +/- 0.30% in the calcium group and 3.54% +/- 0.21% in the placebo group (P = .54). PCNA labeling indices in the most luminal 40% of the crypt were small but, if anything, were higher in the calcium group. There was no patient subgroup within which calcium had an antiproliferative effect; the overall findings persisted among patients with high and low calcium intake, high and low fat intake, and high and low fiber intake.

CONCLUSIONS

Calcium supplementation does not decrease rectal mucosal proliferation, as measured by PCNA (and BrdU) immunohistochemistry, in patients with previous large-bowel adenomas. This study, therefore, does not provide evidence for an anticarcinogenic effect of calcium.

p53 and disease progression in patients with non-small cell lung cancer

Present methods of predicting nodal progression preoperatively in patients with non-small cell lung cancer (NSCLC) are inadequate. Our hypothesis was that p53 expression in primary NSCLC would predict disease progression, making it a useful marker of adverse outcome. From 1987 to 1992, sixty-eight consecutive NSCLC patients underwent potentially curative lung resection and mediastinal lymph node dissection by one surgeon. Primary tumours were analysed using the p53 monoclonal antibody 1801. p53 overexpression was found in 53% of tumours. p53 expression did not correlate with age, gender, histology or stage. A trend toward a higher incidence of p53 expression was seen in tumours with nodal spread (P = 0.06), and p53 expression correlated significantly (P = 0.03) with improved disease-free survival in patients with squamous cell carcinoma (SCC). p53 was the fourth most important independent predictor of survival, behind histology, gender and nodal disease. As a weak independent predictor of survival, the correlation of p53 expression with survival in patients with SCC must be evaluated with caution. If borne out in a larger patient population, p53 expression may be a marker of nodal disease progression in patients with NSCLC.

Imipramine binding to blood platelets and aggressive behavior in offenders, schizophrenics and normal volunteers

The relationships between [3H]imipramine binding to blood platelets and manifestation of aggressive behavior was studied in three different groups of subjects. Arrested offenders displayed high imipramine binding compared to controls, with violent offenders exceeding their nonviolent counterparts. Hostile schizophrenic patients showed imipramine binding higher than nonhostile matched patients. In normal volunteers, on the other hand, no correlation between imipramine binding and scores of aggression was found. The results support the notion about the involvement of a neuronal serotonergic system in the regulation of aggressive behavior. The contribution of this biological factor is detectable in pathological manifestation of aggression but not in normal behavior.

The paradigm shift: behavioral home care

Home care agencies looking to compete in today's competitive market must learn to target their services to market niches and to keep their eyes on marketplace trends. This article examines the changes occurring in behavioral home care and how agencies can tailor their services to their communities.

Ethical, behavioral, and social aspects of HIV vaccine trials in developing countries

ISSUE

Several investigators are preparing to conduct efficacy trials of human immunodeficiency virus (HIV) vaccines in the developing world. Failure to adequately address the unique ethical, behavioral, and social issues that surround vaccine testing in that setting will jeopardize the success of these trials and future acquired immunodeficiency syndrome (AIDS) research in the host nation.

DESCRIPTION OF THE PROJECT

Twelve investigators from Africa, Asia, North America, and South America reviewed previous experience with HIV trials in developing countries and explored potential solutions to these issues.

CONCLUSIONS

Host country scientists, government officials, and media must be actively involved in all aspects of the trials. Minimum prerequisites for conducting the trial include the following: (1) researching vaccines active against developing world HIV isolates; (2) establishing and maintaining an adequate technological infrastructure; (3) assessing the feasibility of recruitment in countries where the existence of HIV may be denied; (4) designing methods to obtain informed consent from each individual subject, rather than exclusively from family members or community elders; (5) creating locally appropriate instruments to measure risk behavior; (6) identifying a behavioral intervention for placebo and treatment groups; (7) making available laboratory methods to distinguish between natural HIV infection and vaccine-induced seropositivity; and (8) guaranteeing that an effective vaccine is available free of charge to the placebo group and at affordable prices to other host country residents.

AIDS education for hospital workers in Manila: effects on knowledge, attitudes, and infection control practices

OBJECTIVE

To evaluate an AIDS education intervention for health workers in Metro Manila hospitals.

METHODS

A randomized controlled education program consisting of lectures, role-plays, posters and pamphlets was delivered to physicians, nurses, laboratory technologists and orderlies in Manila hospitals. Knowledge, attitudes and infection control practices were measured before, immediately after, and 2 months after the intervention.

RESULTS

Baseline survey among 641 hospital workers revealed poor knowledge, negative attitudes towards AIDS patients, and inappropriate infection control practices. Immediately after the intervention, there was significant improvement in (1) knowledge scores (8.7-11.2 in the intervention group versus 8.5-9.5 in the control group; range, 0-14), (2) attitude scores (54.4-60.6 versus 54.6-56.8; range, 22-88), and (3) needle-recapping practices (14-43% versus 39-43%) (all P values < 0.001). After 2 months, attitude scores in the experimental group fell to the same level as those of the control group, while improvements in knowledge and needle recapping were largely maintained. Role-playing was considered by the participants to be the most effective component of the intervention.

CONCLUSIONS

These results suggest that AIDS training for hospital workers in the Philippines and in similar countries is necessary and can be effective. Ideally, such training should include role-playing and should be ongoing in order to sustain the effect.

A spreadsheet for AIDS: estimating heterosexual injection drug user population size from AIDS statistics in San Francisco

A single-page computer spreadsheet can be used to back-calculate the size of the population at risk from the reported number of AIDS cases and HIV seropositivity levels for that population. However, Cohen (1988:35) has cautioned that "this method requires some heroic assumptions, and is, therefore, fraught with difficulty." Slight variations in the definition of AIDS, in the progression rate, and in reported seropositivity rates used as data in the spreadsheet can make enormous differences in the results obtained through back-calculation. Despite the limitations of the method, an estimate of the possible size of the IDU population can be derived from back-calculation, with careful consideration of ethnographic realities taken into account. In San Francisco, the present authors believe that there were approximately 13,000 heterosexual IDUs as of the end of 1989. Further demographic divisions by ethnicity, age, sex, and even neighborhood could be made using the same techniques, if AIDS cases and seropositivity levels could be obtained for each variable. Table II predicts a cumulative 705 AIDS diagnoses among San Francisco heterosexual IDUs by the end of 1993, or nearly six times as many as reported through 1988. This prediction is based on an assumption of 2.5% seroconversion per year (1989-1993) and on modest progression-rate increments of 5%, 5%, 4%, 3%, and 3% in the eleventh through fifteenth years after HIV infection. Thus, it shows the magnitude of the epidemic that San Francisco will shortly face and emphasizes the need to act vigorously to prevent further HIV contagion among IDUs as well as from them to their heterosexual partners (drug using or not).(ABSTRACT TRUNCATED AT 250 WORDS)

Are lower penalties a green light for drug users?

It is probable that DAWN reporters have become more thorough over the years and that the police have become more active in the drug arena during the first half of the 1980's. If this is in fact the case, both sets of statistics would suggest that marijuana use has declined while the use of other illegal drugs, for which possession is penalized as heavily as ever, has risen substantially--although not quite so much as the statistics imply. In sum, the two best statistical indicators of drug use in California show that lowering penalties for marijuana possession did not cause a rise in the use of that drug. On the contrary, these indicators point to a stable situation regarding marijuana use in the decade after the implementation of the Moscone Act, while the use of other illegal drugs soared.

Long-term results of dialysis and transplantation in patients with end-stage renal failure from hypernephroma

We analyzed long-term, 2- to 9-year results and risk factors in 13 patients treated with dialysis and transplantation for hypernephroma. Eight were dialyzed only, 6 died, 4 of them from metastatic disease that occurred in less than 8 months in 3. Five patients were also transplanted. Three died, 1 of metastatic disease. Two are alive, 1 with metastatic disease, 6 years after transplant, 3 years after diagnosis of metastasis. There were no differences in age and sex in those with early metastatic disease when compared to those without, but stage III-IV disease and time of less than 5 years between first and second nephrectomy were more common in those with early metastatic disease. These data indicate that a 7-month waiting time on dialysis is enough to avoid transplanting those with early recurrence, and that patients with stage III-IV and early reappearance of tumor in the second kidney are best treated with conservative management rather than a second total nephrectomy.

Benefits versus risks in conservation surgery with irradiation for breast cancer

This report analyzes the survival and complications inherent in the conventional treatment of breast cancer, radical mastectomy, and the more conservative procedure, conservation surgery with irradiation. Both procedures have benefits and risks. The benefits as measured by survivorship appear to be approximately the same. The major benefit of conservation surgery with irradiation is that the breast is left intact. The possible complication of irradiation carcinogenesis is addressed, and the literature analyzed. This review indicates that the absolute risk of breast cancer developing in the second breast is not nearly as great as originally thought. It is concluded that if a woman with breast cancer is a candidate for either mastectomy or the conservative procedure, it is the clinician's obligation to objectively present the evidence regarding the benefits and risks of these procedures.

Comparison of two isotope dilution/mass spectrometric methods for determination of total serum cholesterol

Isotope dilution/mass spectrometric methods for total serum cholesterol, developed separately at the Karolinska Institutet (KI) and the National Bureau of Standards (NBS), were compared by applying them to a common set of serum pools. A search for the cause of a systematic difference of a few percent in results from the two methods revealed that the KI cholesterol standard contained lathosterol, which interfered with the calibration of the method. With NBS Standard Reference Material cholesterol used for new analyses at the KI, the average difference in mean values dropped to 0.2%. The NBS results are more precise. This is attributed to the protocols NBS used for sample preparation and mass spectrometry. However, these protocols make the NBS method more complex and time-consuming. A recent critical article on the use of this technique for total cholesterol is also examined.

Comparison of two isotope dilution/mass spectrometric methods for determination of total serum cholesterol

Isotope dilution/mass spectrometric methods for total serum cholesterol, developed separately at the Karolinska Institutet (KI) and the National Bureau of Standards (NBS), were compared by applying them to a common set of serum pools. A search for the cause of a systematic difference of a few percent in results from the two methods revealed that the KI cholesterol standard contained lathosterol, which interfered with the calibration of the method. With NBS Standard Reference Material cholesterol used for new analyses at the KI, the average difference in mean values dropped to 0.2%. The NBS results are more precise. This is attributed to the protocols NBS used for sample preparation and mass spectrometry. However, these protocols make the NBS method more complex and time-consuming. A recent critical article on the use of this technique for total cholesterol is also examined.

A multilaboratory-evaluated reference method for the determination of serum sodium

We carried out a statistically designed, multilaboratory study to evaluate a flame atomic emission spectroscopic (FAES) method for serum sodium as a Reference Method. definitive values for the serum pools for the study, with sodium in the 110-160 mmol/L range, were determined at the National Bureau of Standards by an ion-exchange/gravimetry method. The multilaboratory FAES results were judged against the preselected performance criteria for the Reference Method: maximum imprecision 1.5 mmol/L, maximum bias 2.0 mmol/L. The standard error of a single laboratory's performance of the method varied with concentration from 0.46 to 0.86 mmol/L with a maximum bias of 1.0 mmol/L; thus, the criteria were satisfied. The cooperating laboratories performed the method with either manual or semi-automated pipetting. Although both modes of pipetting satisfied our acceptability criteria, only the method with semi-automated pipetting is described here as the Reference Method. The statistical results indicate that the precision criterion can be fulfilled with fewer than four replicate analyses.

Statistics blur minority distinctiveness

In their study of the success of drug treatment, Sirotnik and Roffe blurred and probably minimized racial and ethnic distinctions. Their problem was trying to compare Whites, Blacks, and Chicanos with a statistic requiring two-art or scalar variables. Of non-Blacks (compared to Blacks), 29% were Chicanos, and of non-Browns (compared to Chicanos), 32% were Blacks. Nonetheless, of nine variables significantly associated with "staying in treatment," five were blackness, brownness, or synonymous with them. A format with only percentages would enable analysis to see substantive results clearly and in more detail.

The parameterization of predictive value for multisite screening

In the design of a medical screening program, it is standard practice to employ the parameters of sensitivity and specificity of the test, together with the population disease prevalence, in order to obtain the predictive values of the test. Multiphasic screening, i.e. the use of two or more tests on the same occasion to screen for more than a single disease, has stimulated the need for a formulation of the joint predictive value of these tests employed in combination. In this communication a parameterization of joint predictive value is presented in the context of multisite cancer screening. The resulting parameters are related to the separate disease prevalences, as well as to the sensitivities and specificities of the separate tests, under the assumption of statistical independence among cancer screens.