Biomedical subjects

R Attewell

Publications and source records attributed to R Attewell.

At least 37 records · Page 2Linked to original sources

PubMed1990

Mortality and cancer morbidity in workers exposed to low levels of vinyl chloride monomer at a polyvinyl chloride processing plant.

To study whether exposure to low levels of vinyl chloride monomer (VCM) causes increased risk for cancer morbidity and death from ischemic heart disease, a cohort study was performed among 2,031 male workers at a polyvinyl chloride (PVC) processing plant who had been employed for at least 3 months during the period 1945-1980. An almost significantly increased total mortality (SMR = 116, 95% CI 99-136) was found. Deaths caused by violence or intoxication were significantly increased (SMR = 153, 95% CI 109-213), but not deaths from ischemic heart disease (SMR = 100, 95% CI 73-135). A significant increase in total cancer morbidity was observed (SMR = 128, 95% CI 101-161). Respiratory cancers were significantly increased (SMR = 213, 95% CI 127-346). Furthermore, six brain tumors (vs. 2.6 expected) were observed. This increase, however, was not significant (SMR = 229, 95% CI 84-498). No liver hemangiosarcoma was observed. Applying a latency period of greater than or equal to 10 years from start of employment did not change the risk patterns. There were no significant exposure-response associations between exposure estimates for VCM, asbestos, and plasticizers and cancer morbidity.

Adult↗

PubMed1990

Gastrointestinal cancer among cement workers. A case-referent study.

A matched case-referent study was conducted to investigate the risk of gastrointestinal cancer in cement workers. All male cases of cancer in esophagus, stomach, colon and rectum in the period 1922-1988 from two parishes surrounding a cement plant were identified. For each case, four referents were chosen, matched to age and year of death. Employment in the cement plant was confirmed as from plant records or job title noted in the parish books. Of 25 cases with a definite colorectal tumour, 40% had been blue-collar cement workers for 25 years or more, compared with 20% of their referents [odds ratio (OR) 3.2; 95% confidence limits (CI) 1.1-9.4]. There were indications of a dose (time of employment)-response relationship. For 18 cases with an esophageal or stomach tumour, the OR for those ever employed as cement workers was 3.2 (CI 1.0-11), but short-term employment predominated, thus making a causal relationship less likely.

Case-Control Studies↗

PubMed1990

Acute atrial endocardial P wave amplitude and chronic pacemaker sensitivity requirements: relation to patient age and presence of sinus node disease.

Data are reviewed from 88 patients who received double, passive-fixation unipolar endocardial leads for DDD pacemaker treatment. Identical electrodes were used in the right atrium and the right ventricle. Intra-atrial P wave amplitudes, intraventricular QRS complex amplitudes, and atrial and ventricular pacing thresholds were determined at implantation. The intra-atrial P wave amplitudes were not significantly correlated to the intraventricular QRS complex amplitudes. No significant correlation was found between the atrial stimulation thresholds and the ventricular pacing thresholds. The intra-atrial P wave amplitude showed a significant inverse and logarithmic correlation with patient age (P = 0.007). Furthermore, patients with sinus node disease had significantly lower intra-atrial P wave amplitudes (P = 0.04) than patients without this abnormality. The acute atrial and ventricular pacing thresholds and the intraventricular QRS complex amplitude were not correlated to patient age or presence of sinus node disease. Patients requiring higher atrial amplifier sensitivity settings during follow-up were significantly older (P less than 0.05) than those in whom lower atrial sensitivities were sufficient. A postoperative attenuation of the atrial electrogram was detectable by sensitivity programming procedures in 29 of the patients (35%). This phenomenon did not significantly relate to patient age or presence of sinus node disease. No case of permanent atrial undersensing occurred. It is suggested that the lower intra-atrial P wave amplitudes in older patients and patients with sinus node disease reflect degenerative changes in the atrial myocardium. The statistical relations found appear to motivate special attention to atrial sensing in these patient groups.

Adolescent↗

PubMed1990

Atrial and ventricular stimulation threshold development: a comparative study in patients with a DDD pacemaker and two identical carbon-tip leads.

The atrial and ventricular pacing threshold development during the first postoperative year was studied in a group of patients receiving DDD pacemakers. Identical carbon-tip endocardial leads were implanted in atrium and ventricle. Atrial and ventricular voltage stimulation thresholds were measured at implantation, and noninvasively at 1 and 12 months thereafter. The atrial amplifier sensitivity required for adequate P wave sensing during follow-up was also determined. The possible influence of a number of factors upon atrial and ventricular threshold evolution was statistically assessed. The threshold data were complete in 57 patients (mean age +/- SD, 65.2 +/- 12.4 years). Thirteen patients had a diagnosis of sinus node disease, whereas 44 had not. Patient age and diagnosis did not significantly influence atrial or ventricular stimulation threshold development. Atrial sensing thresholds were not related to atrial stimulation thresholds during follow-up. Atrial pacing thresholds were higher than ventricular thresholds at pacemaker implantation (P less than 0.00005), but the postoperative threshold rise and thresholds at 1 and 12 months postoperatively did not differ significantly between the atrium and ventricle. The ratio of chronic to acute stimulation thresholds was higher on the ventricular than on the atrial level (0.001 greater than P greater than 0.0005). The chronic atrial threshold showed a logarithmic relation to the threshold at implantation (P = 0.0006); postoperative threshold rise was not a significant determinant of the chronic atrial threshold (P = NS). On the ventricular level, the reverse was seen: The chronic threshold was related to the postoperative threshold rise (P = 0.0015, logarithmic relation), but not to the implantation threshold (P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Mineral fibres, fibrosis, and asbestos bodies in lung tissue from deceased asbestos cement workers.

Lung tissue from 76 deceased asbestos cement workers (seven with mesothelioma) exposed to chrysotile asbestos and small amounts of amphiboles, has been studied by transmission electron microscopy, together with lung tissue from 96 controls. The exposed workers with mesothelioma had a significantly higher total content of asbestos fibre in the lungs than those without mesothelioma, who in turn, had higher concentrations than the controls (medians 189, 50, and 29 x 10(6) fibres/g (f/g]. Chrysotile was the major type of fibre. The differences were most pronounced for the amphibole fibres (62, 4.7, and 0.15 f/g), especially crocidolite (54, 1.8 and less than 0.001 f/g), but were evident also for tremolite (2.9, less than 0.001, and less than 0.001 f/g) and anthophyllite (1.7, less than 0.001, and less than 0.001 f/g). For amosite, there was no statistically significant difference between lungs from workers with and without mesothelioma; the lungs of workers had, however, higher concentrations than the controls. Strong correlations were found between duration of exposure and content of amphibole fibres in the lungs. Asbestos bodies, counted by light microscopy, were significantly correlated with the amphibole but not with the chrysotile contents. Fibrosis was correlated with the tremolite but not the chrysotile content in lungs from both exposed workers and controls. Overall, similar results were obtained using fibre counts and estimates of mass.

Adult↗

PubMed1990

Deaths and tumours among rotogravure printers exposed to toluene.

A cohort of 1020 rotogravure printers exposed to toluene and employed for a minimum period of three months in eight plants during 1925-85 was studied. Air levels of toluene were available since 1943 in one plant and since 1969 in most. Based on these measurements and on present concentrations of toluene in blood and subcutaneous fat, the yearly average air levels in each plant were estimated. They reached a maximum of about 450 ppm in the 1940s and 1950s but were only about 30 ppm by the mid-1980s. Exposure to benzene had occurred up to the beginning of the 1960s. Compared with regional rates, total mortality did not increase during the observation period 1952-86 (129 observed deaths v 125 expected; SMR = 1.03). There was no increase in mortality from non-malignant diseases of the lungs, nervous system, or gastrointestinal and urinary tracts. There was no overall excess of tumours 1958-85 (68 v 54, SMR = 1.26; 95% confidence interval, CI = 0.95-1.7). Among the specific cancers, only those of the respiratory tract were significantly increased (16 v 9; SMR = 1.76, CI = 1.03-2.9). Statistical significance was not attained, however, when only subjects with an exposure period of at least five years and a latency period of at least 10 years were considered. Further, there were no dose response relations with cumulated toluene dose (ppm years). There were no significant increases of tumours at other sites, including leukaemias/lymphomas/myelomas.

Adult↗

PubMed1990

Mortality and cancer morbidity in cohorts of asbestos cement workers and referents.

Total and cause specific mortality and cancer morbidity were studied among 1929 asbestos cement workers with an estimated median cumulative exposure of 2.3 fibre (f)-years/ml (median intensity 1.2 f/ml, predominantly chrysotile). A local reference cohort of 1233 industrial workers and non-case referents from the exposed cohort were used for comparisons. The risk for pleural mesothelioma was significantly increased (13 cases out of 592 deaths in workers with at least 20 years latency). No case of peritoneal mesothelioma was found. A significant dose response relation was found for cumulative exposure 40 years or more before the diagnosis, with a multiplicative relative risk (RR) of 1.9 for each f-year/ml. No relation was found with duration of exposure when latency was accounted for. There was a significant overrisk in non-malignant respiratory disease (RR = 2.6). The overall risks for respiratory cancer, excluding mesothelioma, and for gastrointestinal cancer were not significantly increased. Surprisingly, colorectal cancer displayed a clear relation with cumulative dose, with an estimated increase of 1.6% in the incidence density ratio for each f-year/ml (but not with duration of exposure).

Asbestos↗

PubMed1990

The blunting of the thyrotropin response to repeated thyrotropin-releasing hormone administration is reduced by dopaminergic blockade both at normal and elevated serum levels of thyroid hormones.

Fifteen premenopausal women were investigated in the follicular phase of the menstrual cycle with two TRH tests within an interval of 48 to 96 h. Ninety min before each TRH test either 10 mg metoclopramide or saline was injected iv in randomized order. The same procedure was repeated in the following menstrual cycle after pretreatment with T4 (0.5 mg daily for 6-14 days). At least 2 months later the same procedure was repeated with T3 pretreatment (60-120 micrograms for 6-8 days) in 9 of them. A multiple regression analysis was used in modelling the relationships between TSH release and serum free T3, T4 and estradiol levels, adjusting for the presence of metoclopramide and the order of the test. No correlation was found between the TSH response to TRH and the serum estradiol level. The TSH response to the second TRH test was approximately half the first one, both in the control situation and after treatment with T4 or T3. The blunting of the TSH response to the second TRH administration was significantly reduced by metoclopramide, both at normal and elevated thyroid hormone levels, suggesting that a dopaminergic mechanism takes part in the blunting.

Adult↗

PubMed1990

Delaying factors in primary treatment of breast cancer.

An effort has been made to study possible delaying factors in the diagnosis and primary treatment of breast cancer. The data are based on 273 female patients, referred to the Department of Oncology, Lund, constituting 50% of all primary breast carcinomas without a previous malignancy diagnosed in 1986 in a catchment area of 1.2 million. Of these, 68% initially consulted a general or private practitioner, whereas only 21% directly consulted surgical departments. The interval from the initial consultation to operation, analysed multivariately, was correlated to the number of referral-steps (13 vs. 75 days), the category of physician initially consulted (15 vs. 33 days), and the outcome of a combined positive or negative mammography + aspiration cytology (13 vs. 58 days). If one or both of these diagnostic procedures were negative, the delay varied considerably between the four categories of physicians initially consulted. The median time between decision and start of radiotherapy was 38 days, constituting 46% of the time from the initial consultation to start of this treatment modality.

Adult↗

PubMed1989

Deaths and tumors among workers grinding stainless steel.

This study examined a cohort of 1,164 males who, during the period 1927-1981, had been employed for 3 months or more in an industry that produced objects from stainless steel. These workers were exposed to the dust of grinding materials, grinding agents, and stainless steel. From 1975 to 1980, measurements of the total dust in the workroom air have shown levels of about one mg/m3 (consisting of chromium at about 0.1 mg/m3 and nickel at about 0.05 mg/m3) during grinding and several mg/m3 (chromium at about 0.01 mg/m3 and nickel at about 0.005 mg/m3) during polishing. Before 1950, the concentrations were probably considerably higher. Compared to a local reference population, a decrease in mortality (63 observed deaths, standardized mortality (SMR) = 0.79, 95% confidence limits CL = 0.61, 1.01) took place during the 1951-1983 observation period among 318 subjects who had been employed for at least five years, allowing a latency period of at least 20 years. Mortality from cancer of the colon/rectum increased (observed deaths = 6, SMR = 2.47, CL = 0.97, 5.58). The mortality from nonmalignant pulmonary disease did not increase (SMR = 0.29, CL = 0.01, 1.81). During the observation period (1958-1983), there was no significant overall excess of tumors (observed cases = 33, standardized morbidity [SMR] = 1.09, CL = 0.76, 1.54). However, tumor morbidity of the colon/rectum (observed 11, SMR = 2.83, CL = 1.47, 5.19) significantly increased. There were no cases of respiratory cancer (expected 4.7, CL = 0, 0.21). Thus, the results indicate an increased risk of intestinal cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromium↗

PubMed1989

Elimination of toluene from venous blood and adipose tissue after occupational exposure.

In a group of 37 rotogravure printers a close correlation (rs = 0.78) was found between the time weighted toluene exposure during a five day working week (range 8-416 mg/m3, median 75) and the concentration of toluene in subcutaneous adipose tissue (range 1.1-20.7 mg/kg, median 3.8). After exposure ceased, the elimination of toluene was followed up in 11 subjects. The toluene concentration in venous blood decreased non-linearly and the elimination curves contained at least three exponential components. The first two had median estimated half times of nine minutes and two hours respectively. The third component, with a median half time of 90 hours, reflected the decline in adipose tissue, which had a median half time of 79 hours (range 44-178). The study showed protracted endogenous toluene exposure from adipose tissue depots long after the end of exogenous exposure. The observations also suggest that the blood toluene concentrations on Monday mornings might be used as an index of the exposure in the previous week.

Adipose Tissue↗

PubMed1989

Self-reported symptoms in the neck and upper limbs of female assembly workers. Impact of length of employment, work pace, and selection.

In a questionnaire study 148 women in assembly work reported statistically significantly higher rates of pain, in the last 7 d, in their shoulders (odds ratio 3.4) and hands (odds ratio 2.8) as compared to 60 referents age-adjusted. There was a strong association between duration of employment and complaints in the hands. For the younger women, but not the older ones, there was an increase in pain in the shoulders, neck, and upper back with duration of employment. The odds ratio for pain in the shoulders and neck increased with an increasing work pace, except for very high paces, for which there was a decrease. Among 76 former assembly workers 26% reported pain as the cause of having left this work. There was no overall increase in the frequency of complaints among those who had left.

Adolescent↗

PubMed1988

Environmental exposure to lead and arsenic among children living near a glassworks.

Concentrations of lead (Pb) in blood (B-Pb, geometric mean 34.6 micrograms l-1, n = 127) and inorganic arsenic (As) and its metabolites in urine (U-As, mean 5.1 micrograms/g creatinine, n = 35) did not differ between children living in a village close to a glassworks emitting both Pb and As and children living in a reference area. There was no significant effect on B-Pb and U-As related to parents working at the glassworks or consumption of domestically grown vegetables. Neither was there any significant effect upon B-Pb of sex, age, potentially lead-exposing hobbies, or consumption of canned foods. Boys had higher U-As than girls (5.8 vs 4.2 micrograms/g creatinine, p = 0.005), and there was a decrease with age (range 8.4-10.4 years, 27% per year, p = 0.01). Further, parental smoking habits had a significant effect on both B-Pb and U-As. In children of non-smoking parents the B-Pb was 30 micrograms l-1, in children with one parent who smoked 39 micrograms l-1 (smoking father 37, smoking mother 41 micrograms l-1) and in children with two parents who smoked 47 micrograms l-1 (p less than 0.001). The corresponding values for U-As were 4.2, 5.5, and 13 micrograms/g creatinine, respectively (p = 0.01).

Adult↗

PubMed1988

Epidemiology of Kaposi's sarcoma in Sweden prior to the acquired immunodeficiency syndrome.

We studied retrospectively 529 cases of Kaposi's sarcoma (KS) reported to the Swedish Cancer Registry between 1958 and 1982 to determine incidence rates, survival and rate ratios, together with the frequency and types of associated malignancies. The age-standardized (Swedish population 1970) incidence rate generally increased over the time period, with a mean of 0.27 cases per 100,000 population per year (males 0.40, females 0.14). The incidence rate ratio (based on 5-year intervals and relative to the earliest period) reached 2.06 for males and 3.76 for females in the 1968-1972 interval, while the actual peak occurred between 1971 and 1974 for both sexes. Poisson regression modelling suggested a transient shift in the age-specific male incidence rate pattern with a relative increase of the disease in younger age groups (p = 0.05) up to 1968-1972. The age-adjusted male:female ratio did not change significantly from 2.9 during the period of study. In relation to the general population, 18% fewer men and 24% fewer women were alive 10 years after the diagnosis had been made. Ninety-nine (19%) cases had other primaries, of which 17 were neoplasms of lymphocytic origin. Lymphoproliferative malignancy was 2.5 times (95% CI 1.38, 4.37) more common than expected in patients with KS (in particular in females) but a definite increase in other malignancies was not apparent. It is questionable whether immune dysfunction due to other malignant disease or drug therapy can account for the epidemiologic changes in KS, which began almost 2 decades prior to the AIDS epidemic in Sweden.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Prognostication in soft tissue sarcoma. A model with four risk factors.

A multivariate analysis of risk factors for death due to tumor was performed in 82 patients with highly malignant, histologic Grades III and IV primary soft tissue sarcoma of the locomotor system. All the patients had been operated on with a wide or radical surgical margin. Male sex, histologic malignancy Grade IV, extensive tumor necrosis, and tumor size greater than 10 cm were identified as risk factors. Patients with no or one risk factor had a 6(10)-year survival rate of 100% (100%), equal to 96% (96%) in a group with Grade I and Grade II tumors operated on with the same margin. These two groups comprised 50% of all the patients operated on with a wide or radical margin. The 6(10)-year survival rate decreased to 75% (75%) for patients with two risk factors and to 33% (22%) for patients with three or four risk factors. The risk factor model also applied to 62 patients operated on with marginal surgery; and for patients with three or four risk factors, more extensive surgery only had a small effect on long-term survival. The model could be of value when eligibility criteria for trials with adjunctive chemotherapy are determined.

Female↗

PubMed1988

Mortality and cancer morbidity in workers exposed to sulphur dioxide in a sulphuric acid plant.

To evaluate the risk of non-malignant respiratory disease and tumours at exposure to sulphur dioxide, a retrospective cohort study was performed on a group of 400 male workers, employed for at least six months during the period 1961-1981, in a sulphuric acid factory. Since 1969, fairly extensive measurements have been performed in the respiratory zone of the workers. The median level of total dust, over the years, was 2.2 mg/m3 (time-weighted average), of respirable dust 0.6 mg/m3, of sulphur dioxide 3.6 mg/m3, and of arsenic 11 micrograms/m3. There was a significantly increased total mortality in the period 1961-1985. Applying greater than or equal to 5 years latency period there were 47 observed deaths, giving a standardized mortality rate (SMR) of 1.57 (P = 0.002). The increased mortality was due to violence and intoxication (observed 9, SMR = 2.83; P = 0.006) and cardiovascular disease (SMR = 1.51, P = 0.05). The total tumour morbidity was not increased (observed 17, SMR = 1.17, P greater than 0.5) and there was no rise of either non-malignant or malignant lung diseases. However, there was an increase of bladder cancer (observed 5, SMR = 4.36, P = 0.006).

Chemical Industry↗

PubMed1988

Selenium status in females with occupational cervico-brachial complaints.

A hypothesis that selenium deficiency predisposes the development of occupational cervicobrachial complaints was tested in 134 females working in an assembly factory, with constrained work postures and repetitive work tasks. Seventeen subjects, who reported intake of selenium tablets, had higher plasma selenium levels than the others (104 vs 89 micrograms/l, P = 0.01). Among those who did not take selenium tablets, 21% reported symptoms from the upper back during the last 7d, 21% from the neck, 38% from the shoulders, 15% from the elbows, and 27% from the hands. Subjects with pain in their elbows had slightly, but significantly, lower plasma selenium levels than asymptomatics (84 vs 90 micrograms/l, P = 0.048). For the other anatomical regions, there were no statistically significant differences. Thus, there was no major association between selenium status and pain; conclusions regarding any minor association must await further studies.

Adult↗

PubMed1988

Biological effects in a chemical factory with mutagenic exposure. I. Cytogenetic and haematological parameters.

Analysis in two independent laboratories demonstrated no significant differences in chromosome aberrations or micronuclei in lymphocytes from peripheral blood between workers in a chemical factory (exposed to a mixture of chemicals, such as piperazine, low levels of ethylene oxide and formaldehyde, aromatic nitrogen compounds, and other aromatic compounds) compared to unexposed control subjects. The chemical workers had significantly higher counts of lymphocytes (3.57 vs. 2.82 X 10(9)/l; P less than 0.001), eosinophils (0.27 vs. 0.20 X 10(9)/l; P = 0.005), and basophils (0.06 vs. 0.05 X 10(9)/l; P = 0.01) than the controls. Twenty workers exposed to piperazine had higher total numbers of B-lymphocytes than control subjects.

Adult↗