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Biomedical subjects

M Zack

Publications and source records attributed to M Zack.

50 records · Page 3Linked to original sources
PubMed1990

The risk of large bowel cancer after partial gastrectomy for benign ulcer disease.

The relative risk (standardized incidence ratio [SIR] for colorectal cancer after partial gastrectomy for ulcer disease was examined in a population-based cohort comprising 6459 patients operated during 1950 to 1958. Follow-up through 1983 revealed 131 cases of colorectal cancer versus 150.3 expected cases (SIR = 0.87; 95% confidence limits 0.73, 1.03). The relative risk was decreased during the first 19 years of follow-up (SIR = 0.75; 0.58, 0.96) and close to equal thereafter (SIR = 1.02; 0.79, 1.29). Sex, age at operation, type of operation, and diagnosis at operation (stomach or duodenal ulcer) did not affect the relative risk significantly. Confounding by socioeconomic status is one conceivable explanation for the decreased relative risk during the first years of follow-up, whereas the increasing risk with longer duration of follow-up might be a consequence of the surgical procedure itself.

Adult↗
PubMed1989

Time trends in incidence rates of first hip fracture in the Uppsala Health Care Region, Sweden, 1965-1983.

Time trends from 1965 through 1983 for age-specific and age-standardized rates of first hospital admission for a proximal femur fracture were studied in the Uppsala Health Care Region, Sweden, using a centralized register for inpatient care. During the 19-year study period, 29,277 hospital admissions for a first hip fracture were recorded in this population of about 1.5 million persons. The total number of first hip fracture admissions per year increased for both sexes. Age-standardized admission rates for both cervical and trochanteric fractures increased in men (average change per year of 1.8% and 2.6%, respectively) in contrast to the decreased admission rate for cervical fractures (-1.6% per year) and a stable rate for trochanteric fractures (0.4% per year) in women. The cumulative rate of cervical or trochanteric fracture at ages 30-79 years increased 46% in men (from 42/1,000 population in 1965 to 61.5/1,000 population in 1983) in contrast to a 24% decrease in women (from 134/1,000 population in 1965 to 101.5/1,000 population in 1983). The female:male ratio of age-standardized incidence rates decreased for both types of fracture during the study period. This finding of stable or decreasing rates of hip fracture in women contrasts with the findings of most previous studies.

Adult↗
PubMed1988

Stomach cancer after partial gastrectomy for benign ulcer disease.

We followed for 25 to 33 years 6459 patients who had undergone partial gastrectomy for benign ulcer disease to determine the incidence of stomach cancer. The overall risk was no different from that among sex- and age-matched controls from the Swedish Cancer Registry (standardized incidence ratio = 0.96; 95 percent confidence limits, 0.78 and 1.16). However, when the patients were classified according to the duration of follow-up after operation, sex, surgical procedure, diagnosis at the time of operation, and age at operation, differences in risk were observed between the subgroups. After adjustment for potential confounding variables, the average adjusted risk increased 28 percent (adjusted standardized incidence ratio = 1.28; 95 percent confidence limits, 1.11 and 1.49) for each successive five-year interval after operation. The adjusted risk was greater among women than men (adjusted standardized incidence ratio = 1.96; 95 percent confidence limits, 1.18 and 3.24). Patients who had undergone a Billroth I anastomosis had a lower crude risk, both overall (standardized incidence ratio = 0.40; 95 percent confidence limits, 0.20 and 0.71) and after we controlled for other confounding variables (adjusted standardized incidence ratio = 0.27; 95 percent confidence limits, 0.12 and 0.62), than did those who had undergone a Billroth II procedure. The adjusted risk of stomach cancer was greater among patients operated on for gastric ulcer than among those operated on for duodenal ulcer (adjusted standardized incidence ratio = 2.21; 95 percent confidence limits, 1.45 and 3.35). Risk decreased with increased age at operation. Between successive strata of age at operation (less than 39, 40 to 49, 50 to 59, and greater than or equal to 60 years of age), the adjusted risk decreased on the average by about half (adjusted standardized incidence ratio = 0.52; 95 percent confidence limits, 0.41 and 0.66).

Adult↗
PubMed1985

Life-style factors among patients with melanoma.

For the period 1975 to 1980, melanoma incidence in persons 10 through 49 years of age in a southwest Georgia town was significantly increased compared with US rates (expected = 9; observed = 41) and Atlanta rates (expected = 13; observed = 41). We surveyed 36 white patients with melanoma and 74 unaffected control subjects to identify risk factors possibly associated with melanoma in this population. When compared with the controls, the patients more often had a history of melanoma in family members [odds ratio (OR) = 8.00; 95% confidence limits (CL) = 0.89 to 71.6; P = .063]; skin sensitivity to sun exposure (OR = 1.63; CL = 1.04 to 2.56; P = 0.016); or preexisting pigmented nevi (OR = infinity; one-sided 95% lower limit = 1.94, P = .005). More male patients had melanomas on covered body sites, though 67% of melanomas in both sexes occurred on normally covered sites. Patients in our study also had been exposed more often than controls to sick animals in the year before onset (OR = 3.18; CL = 0.92 to 11.0; P = .055) and to pesticides in nonoccupational settings (OR = 3.56; CL = 0.87 to 14.5; P = .059).

Adolescent↗
PubMed1984

Polycythemia vera among participants of a nuclear weapons test.

Two cases of polycythemia vera and two cases of suspected polycythemia vera were found among 3,217 nuclear test participants present during the detonation of the nuclear device, "Smoky," on Aug 31, 1957, and traced through December 1981. The observed occurrence of four cases of polycythemia vera in a group this size significantly exceeds that expected. However, the small individual whole-body doses of radiation reported for these four participants makes the association with ionizing radiation tenuous, although this was the only known unusual risk factor.

Adult↗
PubMed1984

Childhood cancer and occupational radiation exposure in parents.

To test the hypothesis that a parent's job exposure to radiation affects his or her child's risk of cancer, the authors compared this exposure during the year before the child's birth for parents of children with and without cancer. Parents of children with cancer were no more likely to have worked in occupations, industries, or combined occupations and industries with potential ionizing radiation exposure. Bone cancer and Wilms' tumor occurred more frequently among children of fathers in all industries with moderate potential ionizing radiation exposure. Children with cancer more often had fathers who were aircraft mechanics (odds ratio (OR) = infinity, one-sided 95% lower limit = 1.5; P = 0.04). Although four of these six were military aircraft mechanics, only children whose fathers had military jobs with potential ionizing radiation exposure had an increased cancer risk (OR = 2.73; P = 0.01). Four cancer types occurred more often among children of fathers in specific radiation-related occupations: rhabdomyosarcoma among children whose fathers were petroleum industry foremen; retinoblastoma among children whose fathers were radio and television repairmen; central nervous system cancers and other lymphatic cancers among children of Air Force fathers. Because numbers of case fathers are small and confidence limits are broad, the associations identified by this study need to be confirmed in other studies. Better identification and gradation of occupational exposure to radiation would increase the sensitivity to detect associations.

Adult↗
PubMed1983

Mortality and cancer frequency among military nuclear test (Smoky) participants, 1957 through 1979.

Follow-up of health status has been completed through 1979 for 3,072 (95.5%) of 3,217 nuclear test participants on military maneuvers during the 1957 nuclear test "Smoky." In these participants, 112 cases of cancer were diagnosed, compared with 117.5 cases expected. During the same follow-up period (1957 through 1979), 64 persons died of cancer, compared with an expected 64.3. Statistically significantly increased frequency of occurrence and mortality was found only for leukemia. The amount of cumulative gamma radiation exposure for 1957 ranged from 0 to 10,397 mrem as measured by individual personnel film badges. Although uncertainty remains about the exact amount of radiation exposure, the lack of a significant increase after 22 years in either the incidence of or the mortality from any other cancer and the apparent lack of a dose effect by unit lead to the consideration that the leukemia findings may be attributable either to chance, to factors other than radiation, or to some combination of risk factors possibly including radiation.

Follow-Up Studies↗
PubMed1982

Risk factors associated with acute myocardial infarction in Kuwait, 1978.

Two hundred and ninety-nine of 428 patients diagnosed with acute myocardial infarction (AMI) in Kuwait during 1978 were matched with hospitalized controls by sex, nationality, and same year of age. Patients were almost six times as likely as controls to be smokers (odds ratio [OR] = 5.6; 95% confidence limits [CL] = 2.8-12.3; P less than 0.0001) and 50% more likely to be diabetic (OR = 1.49; 95% CL = 0.96-2.32; P = 0.06). Patients were less likely than controls to be currently married (OR = 0.23; 95% CL = 0.04-0.84; P = 0.02) or to have a personal history of hypertension (OR = 0.60; 95% CL = 0.39-0.92; P = 0.01). Each of these four exposures affected AMI risk more strongly when considered together with the other three than when considered separately. Although in this study personal history of hypertension appears to reduce AMI risk, selection bias from using a hospital source of controls does not fully account for this reduction. Neither occupation nor socioeconomic status affected AMI risk.

Adult↗
PubMed1980

Cancer in children of parents exposed to hydrocarbon-related industries and occupations.

Recent animal and human studies suggest that prenatal exposure to carcinogens may increase the risk of childhood malignancy. The Texas Childhood Cancer Study (1976-1977) was designed to test the hypothesis that parental exposure to hydrocarbon-related occupations or industries increases this risk. The study subjects, parents of children with and without cancer, were questioned about their job histories. Parents of 296 children with cancer were not exposed to hydrocarbon-related occupations or industries more often than the uncles and aunts of these children, the parents of neighborhood children, or the parents of 283 children without cancer. During the year before birth, odds ratios for fathers of children seen at a hematology clinic with cancer relative to the uncles of these children (0.93), the fathers of neighborhood children (1.33), and the fathers of children seen at the clinic without cancer (0.50) were not statistically significantly different from 1.00 (p greater than 0.05). This lack of association persisted for the year after birth, the year before diagnosis, and the interval from the year before birth to the year of diagnosis; for different diagnoses; for different ages at diagnosis; and for the industries and occupations of female as well as male parents.

Adolescent↗
PubMed1978

Epidemic malathion poisoning in Pakistan malaria workers.

In 1976, epidemic organophosphate insecticide poisoning due to malathion occurred among 7500 field workers in the Pakistan malaria control programme. In July, the peak month of the epidemic, it is estimated that there were about 2800 cases. In field studies low red-cell cholinesterase activities were associated with the signs and symptoms of organophosphate insecticide intoxication. Toxicity was seen with 3 different formulations of the insecticide and was greatest with the products containing increased amounts of isomalathion, a toxic malathion degradation product. Poor work practices, which had developed when D.D.T. was the primary insecticide for malaria control, resulted in excessive skin contact with and percutaneous absorption of the pesticide. Airborne malathion concentrations were very low. Implementation of good work practices and proscription of use of the 2 pesticide formulations most contaminated with isomalathion halted the epidemic in September. An extensive training programme and surveillance system for pesticide toxicity preceded 1977 spraying operations.

Cholinesterases↗
PubMedDate not supplied

Effect of low-level body burdens of lead on the mental development of children: limitations of meta-analysis in a review of longitudinal data.

The effect of low-level body burdens of lead on the intelligence of children, as measured by intelligence quotient (IQ), was assessed. We reviewed 35 reports from five longitudinal studies conducted in the United States and Australia. In each of these studies, infants were followed for 58 mo or less. The study populations consisted of low- and middle-socioeconomic-class infants who had low-level exposure to environmental lead. Blood-lead levels were measured in a standard fashion at various times, beginning in the prenatal period, and intelligence was first measured at 6 mo of age and was followed by subsequent assessments. Studies were assessed for quality by a review panel blinded to the identity of the investigators and their affiliations. Efforts were made to pool the data with meta-analytic techniques, but efforts were unsuccessful because the methods used to analyze and report data were inconsistent. Inconsistencies were as follows: (a) there were few instances in which IQ and blood-lead levels were measured at comparable times in different studies; (b) incompatibilities existed among the studies, including differences in independent variables, data transformations, and statistical parameters reported; (c) results conflicted when measurement intervals were comparable (i.e., heterogeneity); (d) patterns of regression and correlation coefficients were inconsistent; and (e) data were insufficient to interconvert the parameters reported. Consequently, definitive conclusions regarding the effect of low-level body burdens of lead on IQ could not be determined from the longitudinal data. Examination of the weight of the evidence from this and other studies, however, suggests an adverse relationship of lead on the intelligence of children.

Bias↗
PubMedDate not supplied

Prenatal and neonatal risk factors for childhood myeloid leukemia.

Information about the etiology of childhood myeloid leukemia is limited. A population-based nested case-control study of prenatal and neonatal risk factors for childhood myeloid leukemia was performed with the use of the Swedish National Cancer Register and the Swedish Birth Register. A total of 98 cases of myeloid leukemia were identified in successive birth cohorts from 1973 through 1989. From the Birth Register, five controls were matched to each case. Fourteen of the 98 cases with myeloid leukemia and none of the controls had Down syndrome [odds ratio (OR) = infinity; 95% confidence interval (CI) = 21.0-infinity]. The risk for myeloid leukemia also increased among children who had physiological jaundice (OR = 2.5; 95% CI = 1.2-5.0; children who had been treated with phototherapy (OR = 7.5; 95% CI = 1.8-31.9); or who had been treated in an incubator (OR = 3.5; 95% CI = 1.2-10.2). Excluding cases with Down syndrome, however, decreased these risks, so that their 95% lower confidence interval included the no-effect value. Maternal age < 20 years old (OR = 2.5; 95% CI = 1.1-6.0), hypertension (OR = 2.4; 95% CI = 1.2-5.0), Cesarean section (OR = 2.5; 95% CI = 1.3-4.9), maternal smoking (OR = 2.4; 95% CI = 0.9-6.5), and being one of a multiple birth (OR = 3.6; 95% CI = 1.1-11.3) increased the risk for myeloid leukemia among those without Down syndrome. When the analyses were repeated, by restricting the cases to those with acute myeloid leukemia, the risk associated with young maternal age declined and became nonsignificant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗