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L Polissar

Publications and source records attributed to L Polissar.

At least 19 recordsLinked to original sources
PubMed1991

Prostate specific antigen in the management of patients with localized adenocarcinoma of the prostate treated with primary radiation therapy.

The records of 143 patients treated at 5 institutions with external beam megavoltage irradiation for localized prostatic cancer were reviewed to evaluate post-treatment changes in prostate specific antigen (PSA) in the context of subsequent events. Complete responders were defined as patients clinically well with normal PSA, clinical failures were patients with documented local tumor recurrence or distant metastases and chemical failures were patients clinically well but with a PSA level above the upper limits of normal. Correlations with pre-treatment PSA values were also made for the 50 of 143 patients for whom pre-treatment PSA data were available. Median patient followup was 27 months (range 18 to 91 months). The data were analyzed with parametric and nonparametric univariate and multivariate statistical procedures. Pre-treatment PSA levels increased with increasing tumor stage (p = 0.004) but not with increasing summed Gleason pattern scores (p = 0.15). The probability of remaining a complete responder decreased with increasing stage (p = 0.008) but not with increasing Gleason score (p = 0.14). Increasing pre-treatment PSA correlated with clinical failure (p = 0.01) and chemical failure (p = 0.006). Of the patients with a pre-treatment PSA level of less than 4 times the upper limits of normal 83% remained as complete responders compared to 30% of those with a higher pre-treatment PSA (p = 0.0002). The return of PSA levels to the normal range within 6 months after treatment was strongly correlated with a favorable outcome when analyzed by multivariate logistic regression. The status at last followup of patients who had a normal PSA level at 6 months versus those with an elevated PSA level 6 months after treatment is 94% versus 8% for complete responders (p = 0.0001), 0% versus 60% for clinical failures (p = 0.002) and 6% versus 32% for chemical failures (p = 0.14). Similar results occurred when analyzing outcomes in relationship to PSA normalization within 12 months after treatment (p = 0.001 for clinical failures, p = 0.02 for chemical failures and p = 0.001 for complete responders). We conclude that the pre-treatment level of PSA is an independent prognostic factor for prostate cancer patients treated with primary radiation therapy, and that the failure of PSA to return to the normal range within 1 year after completion of treatment identifies a group of patients at high risk for tumor recurrence.

Adenocarcinoma↗
PubMed1991

Six- and twelve-month abstinence rates in inpatient alcoholics treated with aversion therapy compared with matched inpatients from a treatment registry.

Two hundred forty-nine patients who were treated for alcoholism in an inpatient multimodal treatment program that included aversion therapy were matched post hoc on 17 baseline variables with patients from a national treatment outcome registry. The latter patients received inpatient treatment that emphasized individual and group counseling as the primary therapeutic elements but did not include aversion therapy for alcohol. Six- and 12-month abstinence rates from alcohol and all mood-altering chemicals are reported. The patients treated with aversion therapy for alcohol had higher alcohol abstinence rates at 6 and 12 months (p less than 0.01). The abstinence rates from all mood-altering chemicals were higher in the aversion group at 6 months (p less than 0.05) but not at 12 months. The largest differences between treatment groups in 6-month alcohol abstinence rates were noted for males (p less than 0.001), those over 35 (p less than 0.001), daily drinkers (p less than 0.001), and those with alcohol-related work performance problems (p less than 0.05).

Adult↗
PubMed1991

Relative contribution of gravity to pulmonary perfusion heterogeneity.

We designed a series of experiments and analyses to quantify the contribution of gravity to pulmonary perfusion heterogeneity. Regional pulmonary perfusion was measured in five anesthetized and ventilated dogs in both supine and prone positions by use of radiolabeled microspheres injected during apnea at functional residual capacity. Measurements of flow were repeated in each position, and the sequence of positions was prospectively designed to nullify any effect of order. The lungs of each animal were excised, perfused with saline until clear, dried at an inflation pressure of 25 cmH2O, and cut into 1.9-cm3 pieces. Each piece was weighed and the radioactivity determined in a scintillation counter. Measurement errors were minimized by excluding lung pieces that had greater than 25% airway and weighed less than 10 mg or greater than 60 mg. Weight-normalized flows in each position and repetition were determined for each lung piece. An analysis of variance model was used to identify the percentage of variation in regional flow that was due to position (supine vs. prone), to random error and time (measurement and repetition), and to structure, where structure was defined as the component of flow that remained constant across position and replication. The contributions of position, error/time, and structure to the total variability of flow across the five dogs were 7.8 +/- 0.6, 8.4 +/- 8.3, and 83.8 +/- 8.4%, (SD), respectively. Because the contribution of position represents the additive effect of gravity between two opposite positions, the contribution of gravity to perfusion heterogeneity in one position may be as little as 4%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Carpal tunnel syndrome: objective measures and splint use.

One hundred five adults with carpal tunnel syndrome (CTS) were studied to assess the efficacy of a neutral-angle wrist splint, and to identify criteria for splint referral. Ten observations before and after treatment were analyzed with descriptive and inferential statistics. After splint use, 67% of the subjects reported symptom relief. T-test comparison of sensory latency of values before and after treatment indicated improvement for the total group. Chi-square and t-tests failed to reveal significant differences between relief and no-relief groups for gender, affected hand, presence of concomitant conditions, duration of symptoms before treatment, age, length of time between pretreatment and posttreatment nerve conduction testing, initial nerve latency of motor and sensory fibers, or the difference between pretreatment and posttreatment sensory latencies. A significant difference was found for motor latency; the relief group improved and the no-relief group deteriorated. Data suggest that splinting is most effective if applied within three months of symptom onset. Those with damage to the wrist structures or median nerve were least responsive to splinting.

Adult↗
PubMed1990

Pathways of human exposure to arsenic in a community surrounding a copper smelter.

Several studies have found elevated levels of urinary arsenic among residents living near a copper smelter in Tacoma, Washington. To assess pathways of exposure to arsenic from the smelter, biological and environmental samples were collected longitudinally from 121 households up to 8 miles from the smelter. The concentration of inorganic and methylated arsenic compounds in spot urine samples was used as the primary measure of exposure to environmental arsenic. Urinary concentration of arsenic dropped off to a constant background level within one-half mile of the smelter in contrast to environmental concentrations, which decreased more steadily with increasing distance. Among all age-sex-specific groups in all areas, only children ages 0-6 living within one-half mile of the smelter had elevated levels of arsenic in urine. A separate analysis of data for these children suggests that hand-to-mouth activity was the primary source of exposure. Inhalation of ambient air and resuspension of contaminated soil were not important sources of exposure for children or adults.

Adolescent↗
PubMed1990

The effect of variable environmental arsenic contamination on urinary concentrations of arsenic species.

Urinary arsenic species have been determined for approximately 3000 urine samples obtained from residents of a community surrounding an arsenic-emitting copper smelter. Levels of inorganic, monomethylated and dimethylated arsenic species ranged from less than 1 microgram/L (the instrumental detection limit) to 180 micrograms/L seen for dimethyl arsenic. Comparison of a subsample of this population that had the least environmental contamination with the subsample having highest environmental arsenic concentrations showed small but statistically significant differences in urinary arsenic levels for all species except dimethylated arsenic. However, for children under 7 years of age living in areas with increased environmental arsenic contamination, there was a larger and equally significant (p less than 0.001) increase in all urinary species. This effect was more pronounced in males (5-fold increase in median sum of species concentration over control group) than in females (2-fold increase in median sum of species concentration over control group) and was observed as a weaker effect in the next higher age group (7-13 years of age). Reported consumption of seafood also was significantly related to increased urinary dimethyl arsenic, but changes in distribution among the urinary arsenic species detected was not a sensitive indicator of recent seafood consumption.

Arsenic↗
PubMed1989

Bicycle helmet use by children. Evaluation of a community-wide helmet campaign.

To assess the effect of a community-wide bicycle helmet campaign on helmet use, we observed 9827 children riding bicycles at sites in high-, middle-, and low-income census tracts in Seattle, Wash (intervention city), and Portland, Ore (control city); observations were made during 2-week intervals before and 4, 12, and 16 months after the campaign's start. Helmet use increased from 5.5% before the campaign to 15.7% afterward in Seattle and from 1.0% to 2.9% in Portland. Strong associations were found between helmet use and white compared with black or other race; riding geared vs nongeared bicycles; riding at playgrounds, in parks, or on bicycle paths vs on city streets; and riding with adults or other children compared with riding alone. The proportions of helmet wearers, adjusted for these variables, increased from 4.6% to 14.0% in Seattle and from 1.0% to 3.6% in Portland, a significantly greater increase in use in Seattle compared with Portland. We conclude that a community-wide bicycle helmet campaign can increase helmet use among children.

Adolescent↗
PubMed1989

Factors affecting place of death of hospice and non-hospice cancer patients.

We identified factors associated with death at home for 28,828 hospice and non-hospice cancer patients in 13 counties of western Washington State. Hospice participation was found to be the variable most strongly associated with death at home. Admission to hospice appears to override the tendency for certain subgroups of patients, such as the extreme elderly and those diagnosed close to death, to die in an institutional setting. These findings are discussed with respect to the problem of selection bias.

Adolescent↗
PubMed1989

Grading of soft tissue sarcomas: necrosis as a determinant of survival.

All cases of sarcomas of soft tissue occurring in males age 20-79 in Western Washington from 1981 to 1984 were studied with respect to the influence of multiple clinical, gross, and histologic parameters in predicting survival. Among histologic parameters studied, a strong and statistically significant association of necrosis of more than 15% of the tumor with death was observed. This effect was seen even when controlling for the influence of histology, site, stage of disease, and other factors. It is concluded that necrosis can serve as a prognostically relevant criterion for separating aggressive (nongrade 1) soft tissue sarcomas into intermediate grade (grade 2) and high grade (grade 3) tumors.

Adult↗
PubMed1988

Evaluation and synthesis of health effects studies of communities surrounding arsenic producing industries.

Epidemiological studies designed to detect lung cancer risk and other health effects in communities surrounding arsenic-producing copper smelters were reviewed. The studies were about evenly divided in finding deleterious and 'beneficial' effects of arsenic. All of the studies had insufficient statistical power to detect the small increases in risk that may occur. Even the most powerful studies were not designed to detect relative risks less than about 1.2 and the majority of the studies had little power to detect risks under 2.0. Confidence intervals for the relative risks from these studies were not very useful in putting an upper bound on adverse effects of arsenic. Sources of bias and other difficulties with community health studies are also discussed. We argue that these studies may be a good and economical first investigation but, due to a lack of power, null findings do not rule out the possibility of excess risks that may be significant from a public health viewpoint.

Air Pollutants↗
PubMed1987

Factors affecting place of death in Washington State, 1968-1981.

A study was carried out to determine factors affecting place of death (home, hospital, nursing home or "other places") among all 426,115 resident deaths in Washington State during 1968-1981, using death certificate information. Sixteen percent of deaths occurred at home, 74% in institutions (51% in hospitals, 23% in nursing homes) and 9% at "other places." Age, marital status and cause of death all strongly affect place of death. Further, the effect of each factor was strongly dependent on the others. Sex had no effect on place of death after controlling for other factors. Elderly people died relatively more frequently in nursing homes, infants and middle aged people in hospitals and young adults in "other places." The frequency of deaths at home was quite constant by age. Hospitals were the most common place of death following both vascular disease (including heart attack) and neoplasms, and nursing homes were the most common place of death following cerebrovascular disease (including "stroke"). Race, socioeconomic status and urban or rural residents affected the place of death only slightly or not at all. The place of death pattern changed little during the time period 1968-1981, except for a slight increase in frequency of home deaths and a corresponding decrease in the frequency of deaths in other places. Among cancer patients, the likelihood of death at home was positively associated with longer periods of survival after diagnosis. Cancer patients of hospitals serving targeted populations, such as veterans, were relatively more likely to die in a hospital and less likely to die in a nursing home compared to other cancer patients, suggesting that the "targeted" hospitals are sometimes serving a nursing home function. There was a marked difference in the terminal cancer caseload by hospital. The number of cancer deaths per cancer diagnosis varied widely across hospitals (0.1 to 1.6) and was unrelated to size of the hospital or level of services offered. Intervention aimed at affecting place of death, such as increasing the number of deaths at home, will need to take account of the joint effect of age, marital status and disease.

Adolescent↗
PubMed1987

Race, socioeconomic status, and other prognostic factors for survival from colo-rectal cancer.

Survival data on colo-rectal cancer patients from eleven comprehensive cancer centers were analyzed to examine the effect of race, socioeconomic status and other factors on the probability of survival. Complete data on variables of interest were available for 3617 colon cancer patients (2545 Caucasians and 1072 Blacks) and 1528 rectal cancer patients (1179 Caucasians and 349 Blacks). No significant difference was observed between the races with respect to either the follow-up time or the censoring pattern. For each site, Caucasian patients had a lower risk of death at any time point compared to Black patients, and this difference was maintained within categories of disease stage, sex, age and SES. The race effect was statistically significant in all multivariate models. Moreover, only race was significant in models that considered both race and SES. For either cancer, the racial difference in survival was most prominent for localized disease.

Age Factors↗
PubMed1987

Soft tissue sarcoma and non-Hodgkin's lymphoma in relation to phenoxyherbicide and chlorinated phenol exposure in western Washington.

A population-based case-control study was conducted in western Washington State to evaluate the relationship between occupational exposure of men aged 20-79 to phenoxyacetic acid herbicides and chlorinated phenols and the risks of developing soft tissue sarcoma (STS) and non-Hodgkin's lymphoma (NHL). Occupational histories and other data were obtained by personal interviews for 128 STS cases and 576 NHL cases, diagnosed between 1981 and 1984, and for 694 randomly selected controls without cancer. Among the study subjects with any past occupational exposure to phenoxyherbicides, the estimated relative risk and 95% confidence interval of developing STS was 0.80 (0.5-1.2), and of developing NHL, 1.07 (0.8-1.4). Risk estimates of developing STS and NHL associated with past chlorophenol exposure were 0.99 (0.7-1.5) and 0.99 (0.8-1.2), respectively. No increasing risk of either cancer was associated with overall duration or intensity of chemical exposure or with exposure to any specific phenoxyherbicide per se. However, estimated risks of NHL were elevated among men who had been farmers, 1.33 (1.03-1.7), forestry herbicide applicators, 4.80 (1.2-19.4), and for those potentially exposed to phenoxyherbicides in any occupation for 15 years or more during the period prior to 15 years before cancer diagnosis, 1.71 (1.04-2.8). Increased risks of NHL were also observed among those with occupational exposure to organochlorine insecticides, such as DDT [1.82 (1.04-3.2)] and organic solvents [1.35 (1.06-1.7)], and to other chemicals typically encountered in the agricultural, forestry, or wood products industries. These results demonstrate small but significantly increased risks of developing NHL in association with some occupational activities where phenoxyherbicides have been used in combination with other types of chemicals, particularly for prolonged periods. They do not demonstrate a positive association between increased cancer risks and exposure to any specific phenoxyherbicide product alone. Moreover, these findings provide no evidence of increased risks of developing NHL associated with chlorinated phenol exposure or of developing STS associated with exposure to either class of chemical.

Adult↗
PubMed1986

Menopausal estrogen use and the risk of breast cancer.

The relationship between the occurrence of female breast cancer and menopausal estrogen replacement was investigated in a population-based case-control study. One hundred and eighty-three white female residents of King County, Washington (ages 50-74) in whom breast cancer was diagnosed from July, 1977, through August, 1978, were interviewed with respect to reproductive and other factors, with emphasis on the use of estrogen-containing medication. For purposes of comparison, the same data were collected from 531 white female King County residents of the same ages without breast cancer. Use of menopausal estrogens was reported somewhat more commonly among controls than among cases (relative risk = 0.74, 95% confidence interval = 0.51-1.08) and some variation in proportions of users was present between different hysterectomy-oophorectomy subgroups. However, each of these differences could easily have been due to chance. No substantial trends in risk were apparent with increasing duration of use, time since first use, time since last use, or average dose. The findings suggest that in King County no important relationship exists between use of menopausal estrogens and the occurrence of breast cancer.

Aged↗
PubMed1986

A population-based study of lung cancer incidence trends by histologic type, 1974-81.

All incident cases of microscopically confirmed lung cancer diagnosed between 1974 and 1981 in western Washington State were identified through the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, Bethesda, MD. The incidence of lung cancer by histologic type was studied in relation to time, with age, sex, and stage of disease at diagnosis being taken into account. Overall and within each sex, the incidence of adenocarcinoma has increased significantly since 1974. The rate of increase has been higher among females (86% increase) than among males (54% increase), with most of the increase in both sexes being among those over age 65 years with distant or unstaged disease at diagnosis. Similar patterns were not observed for squamous cell carcinoma. The potential effects of changes in diagnostic and pathology practice during the study period in producing these results were explored, and etiologic implications of the observed increase in adenocarcinoma were discussed.

Adenocarcinoma↗
PubMed1985

Time trends and key factors in the choice of one-step or two-step biopsy and surgery for breast cancer.

The relationship between type of biopsy-mastectomy procedure and four sets of independent variables (physician, patient, hospital and tumor characteristics) was examined for 993 locally-staged breast cancer patients diagnosed between 1974 and 1981 in 13 counties of western Washington State. Time trends were also investigated. Cases were selected from records of a population-based cancer registry. The frequency of the two-step procedure, in which biopsy and surgery occur on different days, increased from 28 to 57% during the 8-year study period. Use of the two-step procedure was associated with younger age of the patient, less suspicious symptoms or mammogram results, younger physician cohorts and hospitals with government and health maintenance organization proprietorship. These relationships remained unchanged after controlling for potentially confounding variables. There were also substantial differences between individual hospitals in the frequency of the two-step procedure, suggesting differing schools of thought in different locales.

Adult↗
PubMed1985

Race, socioeconomic status, and other prognostic factors for survival from prostate cancer.

Survival data on prostate cancer patients from 11 Comprehensive Cancer Centers contributing data to the Centralized Cancer Patient Data System were analyzed to examine the contribution of various factors to the probability of survival from prostate carcinoma. Application of a number of exclusion criteria resulted in a series of 2,513 patients (1,032 blacks and 1,481 Caucasians) for whom complete data on variables of interest were available. The stage of disease at diagnosis was a major determinant of survival. The proportion of blacks presenting the disease in advanced stage was substantially higher than that of Caucasians--a difference which was maintained within each socio-economic status (SES) category. Caucasian patients had a better prognosis than blacks for each disease stage. A dose-response relationship between SES and survival prognosis was observed and this relationship persisted for each stage of the disease. Although both race and SES turned out to be significant in regression models in which one or the other was considered, the model including both race and SES showed only SES to be a significant factor. Hence it can be hypothesized that the racial difference in the survival prognosis for prostate cancer is, to a large extent due to the differences in the distribution of SES in the two races.

Adult↗