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Biomedical subjects

L M Carpenter

Publications and source records attributed to L M Carpenter.

15 recordsLinked to original sources
PubMed1998

Cancer mortality in relation to monitoring for radionuclide exposure in three UK nuclear industry workforces.

Cancer mortality in 40,761 employees of three UK nuclear industry facilities who had been monitored for external radiation exposure was examined according to whether they had also been monitored for possible internal exposure to tritium, plutonium or other radionuclides (uranium, polonium, actinium or other unspecified). Death rates from cancer were compared both with national rates and with rates in radiation workers not monitored for exposure to any radionuclides. Among workers monitored for tritium exposure, overall cancer mortality was significantly below national rates [standardized mortality ratio (SMR) = 83, 165 deaths; 2P = 0.02] and none of the cancer-specific death rates was significantly above either the national average or rates in non-monitored workers. Although the overall death rate from cancer in workers monitored for plutonium exposure was also significantly low relative to national rates (SMR = 89, 581 deaths; 2P = 0.005), mortality from pleural cancer was significantly raised (SMR = 357, nine deaths; 2P = 0.002); none of the rates differed significantly from those of non-monitored workers. Workers monitored for radionuclides other than tritium or plutonium also had a death rate from all cancers combined that was below the national average (SMR = 86, 418 deaths; 2P = 0.002) but prostatic cancer mortality was raised both in relation to death rates in the general population (SMR = 153, 37 deaths; 2P = 0.02) and to death rates in radiation workers who had not been monitored for exposure to any radionuclide [rate ratio (RR) = 1.65; 2P = 0.03]. Mortality from cancer of the lung was also significantly increased in workers monitored for other radionuclides compared with those of radiation workers not monitored for exposure to radionuclides (RR = 1.31, 164 deaths; 2P = 0.01). For cancers of the lung, prostate and all cancers combined, death rates in monitored workers were examined according to the timing and duration of monitoring for radionuclide exposure, with rates of radiation workers not monitored for any radionuclide forming the comparison group. In tritium-monitored workers, RRs for prostatic cancer varied significantly according to the number of years in which they were monitored (2P = 0.03). In workers monitored for plutonium exposure, RRs for all cancers combined increased with the number of years in which they were monitored (2P = 0.04) and with the number of years since first monitoring (2P = 0.0003). There was little suggestion of systematic variation in RRs for workers monitored for other radionuclides in relation to the timing or duration of monitoring, nor did it appear that their raised rates of cancer of the lung and prostate were explained by external radiation dose. These analyses of cancer mortality in relation to monitoring for radionuclide exposure reported in a large cohort of nuclear industry workers suggest that certain patterns of monitoring for some radionuclides may be associated with higher death rates from cancers of the lung, pleura, prostate and all cancers combined. Some of these findings may be due to chance. Moreover, because of the paucity of related data and lack of information about other possible exposures, such as whether plutonium workers are more likely to be exposed to asbestos, firm conclusions cannot be drawn at this stage. Further investigations of the relationship between radionuclide exposure and cancer in nuclear industry workers are needed.

Adolescent↗
PubMed1997

Breast cancer risk in mothers of twins.

The risk of breast cancer associated with delivering a twin birth was examined in a population-based nested case-control study of nearly 4800 Swedish women with breast cancer and 47000 age-matched control subjects. All were aged less than 50 years and parous. After adjustment for age at first birth and parity, a 29% reduction in breast cancer risk was observed in mothers of twins relative to those who were not (odds ratio = 0.71, 95% confidence interval 0.55-0.91). These results provide evidence that women who bear twins are at reduced risk of breast cancer, one explanation for which may be their unusual levels of hormonal exposure.

Breast Neoplasms↗
PubMed1997

Mortality of doctors in different specialties: findings from a cohort of 20000 NHS hospital consultants.

OBJECTIVES: To examine patterns of cause specific mortality in NHS hospital consultants according to their specialty and to assess these in the context of potential occupational exposures. METHODS: A historical cohort assembled from Department of Health records with follow up through the NHS Central Register involving 18,358 male and 2168 female NHS hospital consultants employed in England and Wales between 1962 and 1979. Main outcome measures examined were cause specific mortality during 1962-92 in all consultants combined, and separately for 17 specialty groups, with age, sex, and calendar year adjusted standardised mortality ratios (SMRs) for comparison with national rates, and rate ratios (RRs) for comparison with rates in all consultants combined. RESULTS: The 2798 deaths at ages 25 to 74 reported during the 30 year study period were less than half the number expected on the basis of national rates (SMR 48, 95% confidence interval (95% CI) 46 to 49). Low mortality was evident for cardiovascular disease, lung cancer, other diseases related to smoking, and particularly for diabetes (SMR 14, 95% CI 6 to 29). Death rates from accidental poisoning were significantly raised among male consultants (SMR 227, 95% CI 135 to 359), the excess being most apparent in obstetricians and gynaecologists (SMR 934); almost all deaths from accidental poisoning involved prescription drugs. A significantly raised death rate from injury and poisoning among female consultants was due largely to a twofold excess of suicide (SMR 215, 95% CI 93 to 423), the rate for this cause being significantly raised in anaesthetists (SMR 405). Compared with all consultants, significantly raised mortality was found in psychiatrists for all causes combined (RR 1.12), ischaemic heart disease (RR 1.18), and injury and poisoning (RR 1.46); in anaesthetists for cirrhosis (RR 2.22); and in radiologists and radiotherapists for respiratory disease (RR 1.68). There were significant excesses of colon cancer in psychiatrists (RR 1.67, compared with all consultants) and ear, nose, and throat surgeons (RR 2.25); melanoma in anaesthetists (RR 3.33); bladder cancer in general surgeons (RR 2.40); and laryngeal cancer in ophthalmologists (RR 7.63). CONCLUSIONS: Lower rates of smoking will have contributed substantially to the low overall death rates found in consultants, but other beneficial health related behaviours, and better access to health care, may have also played a part. The increased risks of accidental poisoning in male consultants, and of suicide in female consultants are of concern, and better preventive measures are needed. The few significant excesses of specific cancers found in certain specialties have no obvious explanation other than chance. A significant excess mortality from cirrhosis in anaesthetists might reflect an occupational hazard and may warrant further investigation.

Adult↗
PubMed1996

Cancer in electrical workers: an analysis of cancer registrations in England, 1981-87.

Associations between work in the electrical and electronic industry and cancer incidence were assessed using data for 371 890 cancers registered in England between 1981 and 1987, of which 7981 were in electrical workers. Proportional registration ratios (PRRs) were calculated, both with and without the commonest cancers, with adjustment for age, social class, cancer registry of origin and sex. Of four cancers previously linked with work in the electrical and electronic industry (leukaemia, brain, breast and melanoma), only two were significantly raised: leukaemia (PRR=124, 95% CI=109-142, based on 217 cases) and malignant brain cancer (PRR=118, 95% CI=103-136, based on 204 cases). A significantly increased risk was also observed for pleural cancer (PRR=201, 95% CI=167-241, based on 115 cases). The histology of almost 90% of pleural cancers was coded as mesothelioma, confirming the previously observed association between pleural cancer and exposure to asbestos in electrical workers. The extent to which workplace exposures to extremely low frequency electromagnetic fields explains the excesses seen here for leukaemia and brain cancer requires further study.

Adult↗
PubMed1996

Oral contraceptives and cervical cancer--further findings from the Oxford Family Planning Association contraceptive study.

In 1983, we reported results from the Oxford Family Planning Association contraceptive study regarding the association between oral contraceptives (OCs) and cervical neoplasia, after a 10 year follow-up of a cohort of 17,000 women. Further findings from this study are reported here after an additional 12 years of follow-up. A nested case--control design was used in which cases were all women diagnosed under 45 years of age with invasive carcinoma (n = 33), carcinoma in situ (n = 121) or dysplasia (n = 159). Controls were randomly selected from among cohort members and matched to cases on exact year of birth and clinic attended at recruitment to study. Conditional logistic regression analysis was used to determine odds ratios (ORs) and 95% confidence intervals (CIs) associated with various aspects of OC use relative to never users adjusted for social class, smoking, age at first birth and ever use of diaphragm or condom. Ever users of OCs had a slightly elevated OR for all types of cervical neoplasia combined (OR = 1.40, 95% CI 1.00-1.96). Odds ratios were highest for invasive carcinoma (OR = 4.44, 95% CI 1.04-31.6), intermediate for carcinoma in situ (OR = 1.73, 95% CI 1.00-3.00) and lowest for dysplasia (OR = 1.07, 95% CI 0.69-1.66). The elevated risk associated with OC use appeared to be largely confined to current or recent (last use in the past 2 years) long-term users of OCs. Among current or recent users, ORs for all types of cervical neoplasia combined were 3.34 (95% CI 1.96-5.67) for 49-72 months of use, 1.69 (95% CI 0.97-2.95) for 73-96 months and 2.04 (95% CI 1.34-3.11) for 97 or more months. These results suggest a possible effect of OC use on later stages of cervical carcinogenesis, although residual confounding due to sexual factors or human papillomavirus (HPV) infection cannot be ruled out.

Adult↗
PubMed1995

Breast cancer in Swedish women before age 50: evidence of a dual effect of completed pregnancy.

We set out to detect a transient increase in risk of breast cancer following childbirth, the existence of which has been postulated, but for which empirical evidence is contradictory. Breast cancers and births occurring among the cohort of Swedish women born after 1939 were linked, yielding 3,439 cases and 25,140 age-matched controls with at least two children. Within three years of their last childbirth, women had an estimated rate of breast cancer of 1.21 (95 percent confidence interval [CI] = 1.02-1.44) times that of women whose last birth was 10 or more years earlier, after adjustment for parity and age at first birth. Further analyses suggested that this effect reflected, in part, a small transient increase in breast cancer risk that lasts for about three years following completed pregnancy. The effect of age at first birth on breast cancer risk appears to be confounded by time since last birth; the parity-adjusted rate ratio for having a first birth at age 35 years or more compared with under 20 years is reduced from 1.72 (CI = 1.14-2.58) to 1.36 (CI = 0.88-2.09) on additional adjustment for time since last birth. A transient increase in breast cancer risk after childbirth appears thus appears to account for part of the effect of age at first birth on breast cancer risk.

Adult↗
PubMed1993

A cohort study of cystic fibrosis and malignancy.

A cohort of 412 patients first attending a cystic fibrosis (CF) clinic between 1961 and 1989 were followed up to 30 June 1989. The number of malignancies observed in the cohort was compared with the number expected based on the age, sex and calendar-year-specific cancer registration rates for England and Wales. Four CF patients were diagnosed as having malignancies before 30 June 1989. The tumours were: adenocarcinoma of the terminal ileum; adenocarcinoma of the pancreas, testicular teratoma, and B-cell lymphoma. This compares with 0.89 malignancies expected on the basis of rates in England and Wales (Standardised Registration Ratio = 452; 95% confidence interval 122-1150, P = 0.03). The single case of adenocarcinoma of the terminal ileum contrasts with less than 0.001 expected (P = 0.003) and that of the pancreas with 0.007 expected (P = 0.01). A further adenocarcinoma of the pancreas was diagnosed 2 years after the end of the study period. The two cases of pancreatic cancer compare with 0.008 expected (P = 0.0001) during the period to mid 1991. On the basis of the present findings and previous case reports in the literature adenocarcinoma of the pancreas and adenocarcinoma of the terminal ileum may be associated with cystic fibrosis.

Adenocarcinoma↗
PubMed1993

Mortality and cancer incidence in patients with dermatitis herpetiformis: a cohort study.

One hundred and fifty-two patients in whom a diagnosis of dermatitis herpetiformis was made at St John's Hospital for Diseases of the Skin, London, during 1950-85, were followed from the date of diagnosis to the end of 1989 for mortality, and from 1971, or the date of diagnosis if later, to 1986 for cancer incidence. Thirty-eight deaths occurred under the age of 85, slightly fewer than expected on the basis of national general population rates [standardized mortality ratio (SMR) = 87; 95% confidence interval (CI) 61-119]. All-cause mortality was somewhat lower in patients who had followed a gluten-free diet (SMR = 51; 17-120) than in those who had not (SMR = 97; 66-136), but the difference in SMRs was not significant (P = 0.3). Cancer mortality was non-significantly below expectations from national rates (SMR = 72; 31-142), but cancer incidence was significantly increased [standardized registration ratio (SRR) = 394; 180-749]. No particular cancer site accounted for the cancer incidence excess. One death occurred from cancer of the small intestine (SMR = 4953, P = 0.04), and one lymphoma was incident (SRR = 1555, P = 0.12). Increased risks of these malignancies have previously been found to be associated with coeliac disease (which is present in many patients with dermatitis herpetiformis), and with dermatitis herpetiformis, respectively. Mortality from ischaemic heart disease (IHD) was significantly below national rates (SMR = 37; 95% CI 12-86), and was similar in patients who had followed a gluten-free diet and those who had not.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Radiographic manifestations of congenital anomalies affecting the airway.

Congenital anomalies of the airway are generally uncommon, but a vast array of possibilities exists. Some present life-threatening emergencies at birth, and others go undiagnosed for years. Clinical symptoms are often nonspecific, and radiographic evaluation is frequently requested to localize and characterize the lesion before endoscopy, surgery, or medical management. The most common intrinsic congenital anomalies causing airway compromise in infants include choanal atresia, mandibular hypoplasia, laryngomalacia, vocal cord paralysis, and congenital subglottic stenosis. The radiologist must be on the alert for unsuspected additional anomalies involving the airway, lungs, and esophagus, which occur with relative frequency. Numerous extrinsic congenital masses of the head, neck, and mediastinum may compromise the airway. Hemangiomas, lymphangiomas, and teratomas are more likely to be noted at birth, whereas branchial cleft cysts, thyroglossal duct anomalies, and dermoid cysts frequently present later. Mass location and radiographic characteristics usually allow accurate preoperative diagnosis. Intracranial involvement by nasal or nasopharyngeal masses, intrathoracic involvement by lower neck mass, and intraspinal involvement by posterior neck mass must always be sought for radiographically. Persistence of respiratory symptoms after removal of such masses is not uncommon because tracheal deformity and laxity may take months or years to resolve. Recent advances in cine CT and MR imaging promise to improve imaging of the airway in general and in the pediatric population in particular. Significant limitations in imaging of the pediatric larynx remain. As a result, endoscopy continues to be the primary diagnostic tool for airway anomalies of this region.

Head and Neck Neoplasms↗
PubMed1986

Breast self-examination in an urban population: estimates of prevalence and quality of performance.

Interview data from 434 women (aged greater than or equal to 20 years) in two Wellington suburban areas were used to estimate the prevalence and quality of performance of breast self-examination. Although 98% of women were familiar with breast self-examination, and 73% had performed it at least once, only 39% did so at least monthly. Its practice was significantly more common in the middle years (30-59), among Europeans, and in women with tertiary education. Thoroughness or quality of performance was assessed by comparison with Cancer Society recommendations. Scores for examination technique were generally high (mean = 73%) compared with those assessing timing (mean = 47.5%) and conditions under which breast self-examination was performed (mean = 43.3%). Results from this study were compared with 1975-76 New Zealand survey data which produced lower estimates of the prevalence of monthly breast self-examination. Both studies found that more than a quarter of women have never practiced it. Future research and intervention efforts should be directed toward this group of women.

Adult↗
PubMed1986

Cancer mortality and type of water source: findings from a study in the UK.

The age-adjusted, sex-specific mortality rates from certain cancers of the digestive system were analysed by type of water source supplied to 238 urban areas in England, Wales and Scotland using weighted multiple regression. Of the types of water source, the per cent supplied from upland rivers best described the pattern in cancer mortality for each cancer site and each sex. After adjustment was made for a number of socioeconomic factors, the regression coefficient for the percentage of upland river supply remained statistically significant only for female stomach cancer and female intestinal cancer. The association with intestinal cancer could equally well be explained by some other factor with a strong north-west/south-east geographical distribution. The association found for female stomach cancer could not be accounted for by a geographical trend, but suggests a small effect, equivalent to a relative risk of only 1.11. This is an unexpected finding and must be considered a hypothesis, to be tested further by studies conducted by other researchers, in different locations, preferably on individuals.

Adult↗
PubMed1986

Stability of total cholesterol, high-density-lipoprotein cholesterol, and triglycerides in frozen sera.

When human serum must be stored for extended periods before analysis, conditions must be such that samples give results comparable with those for "fresh" (unstored) samples. In a balanced experiment with statistically pre-determined sample size, we assessed, at three-weekly intervals for 18 weeks, the stability of total cholesterol, high-density-lipoprotein cholesterol, and triglycerides in human serum stored at -15 degrees C. No significant changes were observed.

Cholesterol↗
PubMed1985

Neonatal thyroid function: influence of perinatal factors.

Indices of thyroid function were measured in 229 healthy term neonates at birth and at 5, 10, and 15 days of age. Results were analysed to assess whether maternal diabetes mellitus, toxaemia of pregnancy, intrapartum fetal distress, duration of labour, method of delivery, asphyxia at birth, race, sex, birthweight, birth length, head circumference, or method of feeding influenced any index. Thyroxine, the free thyroxine index, and free thyroxine concentrations at birth correlated with birthweight. Method of delivery influenced mean thyroxine and free thyroxine index values at birth and at age 5 days. Mean values of triiodothyronine, reverse triiodothyronine, thyroxine binding globulin, and thyroid stimulating hormone were not affected by any of the perinatal factors studied. Birthweight and perhaps method of delivery should be taken into account when interpreting neonatal thyroxine parameters but determination of thyroid stimulating hormone as a screen for congenital hypothyroidism in healthy term neonates circumvents these considerations.

Birth Weight↗