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Biomedical subjects

M S Wolff

Publications and source records attributed to M S Wolff.

At least 55 records · Page 3Linked to original sources
PubMed1995

Environmental organochlorine exposure as a potential etiologic factor in breast cancer.

Known risk factors for breast cancer do not account for a significant proportion of the overall incidence. Reproductive factors and endogenous hormones are thought to be responsible for a large component of risk. An environmental contribution has been sought in the past to explain the international trends in breast cancer rates and changes in risk among migrating populations. Recently, environmental research has turned to investigation of exogenous chemical exposures, including environmental contamination, as potential risk factors that may arise from the hormonal activity or from the carcinogenicity of many of these chemicals. Several reports since 1991 suggest that organochlorines may be a risk factor for breast cancer. The data are strongest for DDT. For PCBs, the results to date have been equivocal if not entirely negative. However, different groups of polychlorinated biphenyl (PCB) congeners are known to provoke biological responses that are structure specific. A wide divergence of estrogenic response, cytochrome P450 activity, and biological half-life exists within these groups of PCB congeners. Therefore, understanding breast cancer risk from PCB exposure requires attention to congener structures in complex mixtures and to temporal changes in exposure. Investigation of environmental contributions to breast cancer risk offers the potential for understanding more about the etiology of this complex disease and may also provide opportunities for prevention of the most common cancer among women in the United States.

Breast Neoplasms↗
PubMed1994

Breast cancer and serum organochlorines: a prospective study among white, black, and Asian women.

BACKGROUND: Five small case-control studies have examined the relationship between exposure to organochlorines and the risk of breast cancer and have found inconsistent results. In these studies, organochlorine levels in breast cancer patients were measured after (or at most 6 months before) diagnosis. PURPOSE: We tested the hypothesis that organochlorines are a risk factor for breast cancer, using prospectively gathered data on serum levels of DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] (the main metabolite of the pesticide DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane]) and polychlorinated biphenyls (PCBs). METHODS: Study subjects belonged to a cohort of 57,040 women (46,629 white, 8123 black, and 2288 Asian) from the San Francisco Bay Area who took a multiphasic health examination, independent of concern about risk of breast cancer, in the late 1960s. At that time, a sample of blood was obtained, then frozen and stored. Follow-up was through December 31, 1990. We conducted a nested case-control study of 150 case patients and 150 matched control subjects. A random sample of 50 women per racial/ethnic group who had been diagnosed with breast cancer more than 6 months after the multiphasic examination (mean follow-up = 14.2 years) was selected, and each case patient was matched to a cancer-free control subject. RESULTS: Matched analyses found no differences in the case patients' and control subjects' serum levels of DDE (mean difference = 0.2 parts per billion [ppb]; 95% confidence interval [CI] = -6.7, 7.2) or PCBs (mean difference = -0.4 ppb; 95% CI = -0.8, 0.1). DDE levels, however, tended to be higher among black case patients compared with black controls (mean difference = 5.7 ppb; 95% CI = -3.3, 14.8), and PCBs were lower among white case patients compared with white controls (mean difference = -0.6 ppb; 95% CI = -1.2, -0.1). Organochlorine levels were significantly higher among black and Asian women compared with white women. The mean difference for DDE was 11.0 ppb for black women (95% CI = 4.3, 17.6) and 12.6 ppb for Asian women (95% CI = 6.0, 19.2); for PCBs, the respective differences were 0.8 ppb for black women (95% CI = 0.2, 1.4) and 1.4 ppb for Asian women (95% CI = 0.8, 1.9). The results were not altered by adjusting for relevant confounders, and the lack of association between exposure to organochlorines and breast cancer was present regardless of length of follow-up, year of diagnosis, or the case patient's menopausal and estrogen-receptor status. CONCLUSION: The data do not support the hypothesis that exposure to DDE and PCBs increases risk of breast cancer. IMPLICATIONS: Future investigations must consider the biologic mechanisms involved and variations in exposure to chemical pollutants and of breast cancer incidence rates among diverse groups of women.

Adult↗
PubMed1994

Organochlorine exposure estimation in the study of cancer etiology.

This paper discusses sampling and design considerations relevant to the estimation of exposure to organochlorine compounds in epidemiological studies. We consider exposures measured directly via biomarkers of exposure in the body. It is critical for the design, implementation, and evaluation of studies that epidemiologists and biostatisticians be familiar with methodological issues relevant to the direct measure of exposure. Etiologic, toxicokinetic, quality control and quality assurance, and statistical sampling are discussed. Finally, the limitations of these studies and the need for complete reporting of methods are discussed.

Calibration↗
PubMed1993

Blood levels of organochlorine residues and risk of breast cancer.

BACKGROUND: Organochlorines such as DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] and PCBs (polychlorinated biphenyls), which have been used extensively as insecticides and as fluid insulators of electrical components, respectively, are known to be persistent environmental contaminants and animal carcinogens. These agents have been found in human tissue due to their inefficient metabolism and their solubility in lipids, which lead to lifelong sequestration in adipose tissue. Their association with human cancer occurrence, however, has been explored only marginally, with most studies having 20 or fewer cases. PURPOSE: This blinded study was designed to determine whether exposure to PCBs and to DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene], the major metabolite of DDT, is associated with breast cancer risk in women. METHODS: We analyzed sera from the stored blood specimens of 14,290 participants enrolled between 1985 and 1991 in the New York University Women's Health Study, a prospective cohort study of hormones, diet, and cancer. Cohort members who developed breast cancer were included as case patients in our nested case-control study. DDE and PCBs were measured by gas chromatography in the sera of 58 women with a diagnosis of breast cancer 1-6 months after they entered the cohort and in 171 matched control subjects from the same study population who did not develop cancer. RESULTS: Mean levels of DDE and PCBs were higher for breast cancer case patients than for control subjects, but paired differences were statistically significant only for DDE (P = .031). After adjustment for first-degree family history of breast cancer, lifetime lactation, and age at first full-term pregnancy, conditional logistic regression analysis showed a fourfold increase in relative risk of breast cancer for an elevation of serum DDE concentrations from 2.0 ng/mL (10th percentile) to 19.1 ng/mL (90th percentile). For PCBs, the relative risk for a change in serum levels from 3.9 ng/mL (10th percentile) to 10.6 ng/mL (90th percentile) was less than twofold, a nonsignificant association that was further reduced after adjustment for DDE. CONCLUSION: In this population of New York City women, breast cancer was strongly associated with DDE in serum but not with PCBs. IMPLICATIONS: These findings suggest that environmental chemical contamination with organochlorine residues may be an important etiologic factor in breast cancer. Given the widespread dissemination of organochlorine insecticides in the environment and the food chain, the implications are far-reaching for public health intervention worldwide.

Adult↗
PubMed1992

Changes in PCB serum concentrations among capacitor manufacturing workers.

To assess the elimination of PCBs in humans, PCB concentrations in serum from 165 capacitor manufacturing workers were measured twice within a 46-month interval (March 1976-December 1979). Use of PCBs at the facility was entirely eliminated in 1977. PCB congeners with lower chlorination (LPCBs--mainly tri- and tetrachlorobiphenyls) had decreased in concentration, with six of the LPCB 7 peaks observed by packed column GC showing average reductions of 25-90%. Higher chlorinated PCBs did not decrease significantly as a whole, although three of the six constituent congener peaks showed some decline (15-25%). As expected, decreases in PCB congener concentrations were associated with chlorine substitution configurations known to be amenable to metabolism.

Adult↗
PubMed1992

Use of PCB blood levels to assess potential exposure following an electrical transformer explosion.

Following the explosion of a transformer, passersby, building occupants, and cleanup personnel had potential exposure to the transformer dielectric fluid containing polychlorinated biphenyls (PCBs). As part of a medical evaluation, blood serum was analyzed for PCBs, and the concentrations found were similar to that of a regional comparison group (median 4.0 ng/mL or parts per billion, range 1-10, n = 60). Some workers employed by the utility company that owned the transformer had potential exposure to PCBs in the past. This positive comparison group had significantly higher serum PCB concentrations, related to known direct contact (median 5.0, mean 14 ng/mL, 1-187, n = 25) or not (median 4.0, mean 11 ng/mL, 2-72, n = 17). Therefore, in this investigation, elevation of serum PCB levels could be related to past contact during work with transformers, but not to potential short-term exposure at the time of a transfer explosion.

Aroclors↗
PubMed1992

Use of multiple sensitivity measurements and logit statistical analysis to assess the effectiveness of a potassium-citrate-containing dentifrice in reducing dentinal hypersensitivity.

A potassium citrate-SMFP containing dentifrice was tested in a double-blind 8-week clinical trial on subjects with a history of dentinal hypersensitivity. A dentifrice containing SMFP but no potassium salt was used as the control and a 2nd test dentifrice containing potassium nitrate-SMFP was assessed at the same time. The sensitivity of the subjects was evaluated at 0, 3 and 8 weeks using electrical and tactile methods plus a 1-s air blast. The sensitivity scores for each subject at each examination were summarised as a proportion of the examined teeth deemed sensitive. Assessment of any effects of the dentifrices was via an analysis of covariance of the logit transformation of these proportions with the baseline value as the covariate. The use of this novel method of analysis had the advantage of taking into account changes in sensitivity of all of the teeth, both sensitive and non-sensitive, since electrical measurements indicated effects on both. Of the original 120 subjects, 111 completed the trial and the 3 dentifrice groups remained well balanced for age, sex and sensitivity. All 3 dentifrice groups showed statistically significant reductions in sensitivity over the 8 weeks. However, the potassium citrate-SMFP dentifrice was significantly more effective than either the control SMFP dentifrice, or the potassium nitrate-SMFP dentifrice, at reducing sensitivity after 3 weeks, and this difference plus further sensitivity reduction with all 3 dentifrices was observed after 8 weeks.

Adolescent↗
PubMed1992

Preventive resin restorations: indications, technique, and success.

Although preventive resin restorations have been reported since 1977, there is little uniformity concerning the indications for this procedure, nor is there a standard technique. This article proposes diagnostic criteria for pit and fissure occlusal caries and diagnosis-related considerations for treatment planning for preventive resin restorations. A step-by-step "laminate" technique, which includes, successively, a glass-ionomer cement liner, a posterior composite resin, and a sealant, is described. The success rates reported for several clinical studies of preventive resin restorations are presented, although the criteria for this restoration, treatment methodology, and the determinates of success vary from study to study.

Composite Resins↗
PubMed1991

Accidental exposure of children to polychlorinated biphenyls.

Children exposed to polychlorinated biphenyls (PCBs) while playing with parts of a capacitor had elevated serum concentrations of lower chlorinated PCBs, similar to Arochlor 1242. These levels declined over 11 months of followup to about half their initial values, from a mean of 12.9 to 6.3 ppb (parts per billion, ng/mL) among four children. In comparison, other persons in the same household and a reference group of persons seen in the same geographic area had serum levels of Aroclor 1242-like PCBs below the limit of detection (less than 5 ppb). All three groups--the children, household members, and geographic referents--also had higher chlorinated PCBs in their serum similar to Aroclor 1260 (HPCBs). HPCB concentrations were similar in these groups (approximately 2 ppb) and did not decline significantly.

Accidents↗
PubMed1991

The effect of powder/liquid ratio on the in vivo solubility of polycarboxylate cement.

A clinical study of the solubility of three powder/liquid ratios of polycarboxylate cement demonstrated a threefold increase in the solubility for the lower powder/liquid ratios. The three liquid/powder ratios tested were within the range recommended by the manufacturer. The data suggest that the higher powder/liquid ratio (1.5:1) is preferable when minimal solubility is a primary requirement.

Crowns↗
PubMed1991

Chronic pain--assessment of orthopedic physical therapists' knowledge and attitudes.

Orthopedic physical therapists' knowledge of pain mechanisms and methods of pain management and their attitudes toward working with patients with benign chronic pain were studied. A random sample of 500 members of the American Physical Therapy Association's Section on Orthopaedics received by mail a 36-item questionnaire. Statistical analysis of scores, using frequencies, means, and correlations was performed on the 119 (23.8%) usable returns. All but 4% of the respondents preferred to work with patients who are not likely to have chronic pain. Seventy-two percent believed their entry-level education in pain management and theory was very inadequate or less than adequate to deal with an orthopedic patient population. Pain knowledge scores were low (35.8 out of 46 points), and the scores on positive attitudes toward treating patients with benign chronic pain were lower (20.5 out of 36 points). The study suggests specific deficiencies in orthopedic physical therapists' knowledge of clinical pain mechanisms and management and potentially undesirable attitudes toward treating patients with chronic pain.

Attitude of Health Personnel↗
PubMed1990

Detection of adducts of deoxyribonucleic acid in white blood cells of roofers by 32P-postlabeling. Relationship of adduct levels to measures of exposure to polycyclic aromatic hydrocarbons.

To assess the utility of adducts of deoxyribonucleic acid (DNA) as biomarkers of exposure to carcinogens in an industrial population, a pilot study of roofers occupationally exposed to polycyclic aromatic hydrocarbons was conducted. DNA isolated from white blood cells of roofers and nonoccupationally exposed comparison subjects matched for age, sex, and smoking status was analyzed for DNA adducts with the use of 32P-postlabeling methods. Occupational exposures to polycyclic aromatic hydrocarbons were assessed by personal air sampling and skin wipes. Ten of the 12 roofers, but only 2 of the 12 comparison subjects, had detectable levels of aromatic DNA adducts in the 32P-postlabeling assay. Among the roofers, the post-shift levels of polycyclic aromatic hydrocarbons in the skin wipes were correlated with the DNA adduct levels. These results suggest that 32P-postlabeling assay may be useful for monitoring internal exposures to complex mixtures of aromatic hydrocarbons in industrial populations.

Adult↗
PubMed1990

A pilot study of detection of DNA adducts in white blood cells of roofers by 32P-postlabelling.

To assess the utility of DNA adducts as biomarkers of exposure to carcinogens in an industrial population, a pilot study of roofers occupationally exposed to a mixture of polycyclic aromatic hydrocarbons was conducted. DNA was isolated from peripheral white blood cells of roofers and non-occupationally exposed subjects matched for age, sex and smoking status. Occupational exposures to anthracene, fluoranthene, pyrene, benzanthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[g,h,i]perylene and benzo[k]fluoranthene were assessed by personal breathing zone air sampling and skin wipes. Exposures to benzo[a]pyrene in air of exposed subjects ranged from 0.60 microgram/m3 to 1.39 micrograms/m3, and exposures to total polycyclic aromatic hydrocarbon (the sum of eight hydrocarbons) ranged from 6.0 micrograms/m3 to 13.8 micrograms/m3 on the day before blood collection. In the biomarker studies 10 of 12 roofers, but only 2 of 12 comparison subjects, had detectable levels of aromatic DNA adducts by 32P-postlabelling assay (p less than 0.01). The two non-roofers with detectable adducts had levels at or near the detection limit of 2 adducts per 10(9) nucleotides. In two roofer samples which were studied in a mixing experiment, the major adduct spots did not co-migrate with the guanosine N2 adduct of benzo[a]pyrene diol epoxide. These results suggest that the 32P-postlabelling assay may be useful for monitoring exposures to complex mixtures of aromatic hydrocarbons in industrial populations.

Adult↗