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Biomedical subjects

E Ward

Publications and source records attributed to E Ward.

At least 91 records · Page 5Linked to original sources
PubMed1990

Neuroblastoma and parental occupation.

A matched case-control study of neuroblastoma investigated parental occupational risk factors. Cases diagnosed in 1970-1979 were identified through tumor registries in the Greater Philadelphia area. Controls were selected by random digit dialing and were matched to cases on race, birth date, and telephone exchange. Parents of 104 matched pairs were interviewed by telephone. In contrast to results of a previous study, no significant associations were noted for paternal employment in a job cluster of occupations in electricity, electronics, insulation, utility, and printing; in jobs with electromagnetic field exposure; or in jobs as workers in electronics. Six cases and one control, however, had a father or mother who worked in electrical or electronic products assembly.

Case-Control Studies↗
PubMed1990

Screening workers exposed to 4,4'-methylenebis(2-chloroaniline) for bladder cancer by cystoscopy.

A bladder cancer incidence study was conducted among 540 workers exposed to the potential bladder carcinogen 4,4'-methylenebis(2-chloroaniline) from 1969 to 1979. Among the 385 workers who participated in a urine screening examination, none had suspicious or positive cytology. Twenty-one workers had at least one reading of atypia and 60 had either a positive dipstick for heme or greater than five red blood cells per low power field. The study protocol initially involved referral to private physicians for follow-up of any suspicious laboratory results. However, the diagnosis by cystoscopy of a bladder tumor in a nonsmoking man less than 30 years old with low-level hematuria prompted us to offer cystoscopy to all members of the cohort. A total of three tumors were identified in 200 persons who received cystoscopy. All were low-grade, papillary tumors and two occurred in men with completely normal urine screening results. These findings suggest that cystoscopy of asymptomatic persons should be considered in designing bladder cancer screening programs in high-risk cohorts.

Adult↗
PubMed1989

Emergency department detection and follow-up of high blood pressure: use and effectiveness of community health workers.

This study introduced trained paraprofessionals, community health workers (CHWs), into the emergency department (ED) to supplement providers' routine efforts in high blood pressure (HBP) detection, treatment, and follow-up among high-risk black men. In a demonstration project over a 2-year period, CHWs provided (1) BP and pulse measurements, and educational counseling regarding HBP and cardiovascular risk factors; (2) telephone preappointment reminders to improve ED follow-up visit rates; and (3) recontact of patients failing to show for their ED follow-up visits to improve return rates even after missed BP appointments. Results of preappointment reminders by CHWs showed a 19% improvement in appointment keeping (P less than .001). With a sample of patients who had failed to return for a follow-up visit, CHW contact was also effective, showing an overall improvement rate of 7% (P less than .001). The results reported support the idea that individuals from the community, trained as paraprofessionals, can improve appointment keeping as well as be useful in assisting in screening and counseling for chronic conditions within the ED. These CHWs are seen as having the additional advantage of enhancing the integration of the ED, the community, and continuing care sites. The approaches used in this study should be applicable and may serve as a model for the approach to other chronic conditions experienced in urban high-risk communities.

Adult↗
PubMed1989

Anatomic evaluation of cisternal puncture.

Cisternal puncture, although less frequently used since the advent of computed tomography and magnetic resonance imaging, is an important tool in the neurodiagnostic armamentarium. An anatomic study of cisternal puncture was conducted on fresh cadavers by direct visualization and fluoroscopic guidance of cisternal puncture. Anatomic and radiographic analyses demonstrated a dramatic dynamic anatomy of the cisternal space during cisternal puncture and indicated that "tenting" of the dura mater over the needle occurs reliably during cisternal puncture. Lateral fluoroscopy may decrease the risk of cisternal puncture by allowing visualization of needle depth in the cisternal space.

Cerebrospinal Fluid Shunts↗
PubMed1988

Study of mortality among chemical workers in the Kanawha Valley of West Virginia.

To assess the mortality experience of a cohort of chemical workers in the Kanawha Valley of West Virginia, 29,139 males who worked at any one of three facilities over a 39-year period were followed-up for vital status. The facilities include two chemical manufacturing plants and a research and development center. From this cohort, 5,785 men were found to have died as of the study end, December 31, 1978. This was less than the 6,148.5 men expected to have died, based upon the United States white male population (standardized mortality ratio (SMR) = 94, 95% confidence interval (CI) = 92-96). Eighty-six specific causes of death were examined. Statistically significant increased deaths were observed for two causes; cancers of the liver (not specified as primary or secondary) (SMR = 174; CI = 102-280) and lympho- and reticulosarcoma (SMR = 140; CI = 104-187). When all biliary and liver cancer was examined by duration and time since initial employment, the SMR for those who worked at least 25 years and whose deaths occurred 30 years or more after first employment was 301 (95% confidence limit = 168-497). The identification and follow-up of this complete cohort provides the basis for future study of subcohorts with specific chemical and process exposures and case control studies of specific causes of death.

Adult↗
PubMed1988

Bladder tumors in two young males occupationally exposed to MBOCA.

MBOCA (4,4' methylenebis (2-chloroaniline) is a structural analogue of benzidine and is carcinogenic in mice, rats, and dogs. MBOCA has not yet been demonstrated to be carcinogenic in humans and is not regulated as an occupational carcinogen in the United States. We report two noninvasive papillary tumors of the bladder identified in a screening study of 540 workers exposed to MBOCA during its production at a Michigan chemical plant from 1968 to 1979. Both tumors occurred in men under 30 years old who had never smoked. Although the prevalence of grade 1-2 tumors among asymptomatic males in this age group is unknown, the incidence of clinically apparent tumors on U.S. males aged 25-29 is only 1 per 100,000 per year. The detection of the two tumors in young, nonsmoking males is consistent with the hypothesis that MBOCA induces bladder neoplasms in humans.

Adult↗
PubMed1987

The nucleotide sequence of the tnpA gene of Tn21.

The nucleotide sequence of the tnpA gene of Tn21 is presented. The transposase encoded by this gene is exactly the same length (988 amino acids) as the Tn501 transposase (4), and shows 72% homology overall with this protein, with greater homology towards the C-terminus. The sequence of the transposase is discussed in the context of the evolution of Class II transposable elements and of the characteristics of the enzyme's action.

Amino Acid Sequence↗
PubMed1987

4,4'-Methylenebis (2-chloroaniline): an unregulated carcinogen.

4,4'-Methylenebis (2-chloroaniline) (MBOCA) is a confirmed animal carcinogen. It is used commercially as a curing agent for polymers containing isocyanate. There are no adequate studies documenting a carcinogenic risk for MBOCA in humans; however, studies in rats and dogs have shown that MBOCA is a carcinogen. Also, MBOCA is structurally similar to aromatic amines, which cause bladder cancer in workers with occupational exposure. Manufacture of MBOCA in the United States ceased in 1979. However, estimates of the number of workers potentially exposed range from 1,400 to 33,000 in the manufacture of MBOCA-cured products. Presently, there are no federal regulations limiting occupational exposure to MBOCA. An occupational standard for MBOCA proposed by the Occupational Safety and Health Administration was remanded by the Third Circuit Court of Appeals on procedural grounds in 1974. NIOSH recommended in 1978 that MBOCA be treated as a potential human carcinogen and that worker exposure be controlled so that it does not exceed 3 micrograms/m3 of air determined as a time-weighted average concentration for up to a 10-hour workshift (the lowest level that can be reliably measured). In this paper, we will review the literature in regard to MBOCA's carcinogenicity, describe industrial use and extent of worker exposure, and review MBOCA's status in relation to occupational regulations in the United States and abroad.

Animals↗
PubMed1987

Arm function after stroke: measurement and recovery over the first three months.

Four short, simple measures of arm function, suitable for use with patients recovering from acute stroke, are described. These tests are: the Frenchay Arm Test, the Nine Hole Peg Test, finger tapping rate and grip strength. Good interobserver and test-retest reliability was demonstrated for all tests, and the Frenchay Arm Test was shown to be valid. Normal values for all tests were established on 63 controls. It was found that the limited sensitivity of the Frenchay Arm Test could be improved using the Nine Hole Peg Test and grip strength. Recovery of arm function has been studied in a sample of 56 patients seen regularly over the first 3 months after their stroke, using these standard measures. The results demonstrated a wide variation in recovery curves between patients. The use of the Nine Hole Peg Test enabled further recovery to be detected after patients achieved a top score on the Frenchay Arm Test. Failure to recover measureable grip strength before 24 days was associated with absence of useful arm function at three months. Measurement of finger tapping rate was not useful.

Aged↗
PubMed1987

Medical and drug risk factors associated with neuroblastoma: a case-control study.

A matched case-control study of prenatal risk factors for neuroblastoma was conducted, including 104 cases diagnosed over the period 1970-79 in the Greater Delaware Valley. Significantly elevated odds ratios (ORs) were associated with maternal use of a neurally active drug during pregnancy (OR = 2.83), sex hormone exposure 3 months prior to or during pregnancy (OR = 2.25), frequent alcohol consumption during pregnancy (OR = 9.0), and maternal use of diuretic drugs during pregnancy (OR = 5.75). Significantly more case mothers than control mothers reported use of hair coloring products during pregnancy (OR = 3.0). No association was found between cigarette smoking, coffee consumption, or medical irradiation and case-control status.

Alcohol Drinking↗
PubMed1986

Efficacy of urinary monitoring for 4,4'-methylenebis (2-chloroaniline).

The aromatic amine 4,4'-methylenebis (2-chloroaniline) (MBOCA), an animal carcinogen, is used commercially as a curing agent for isocyanate-containing polymers. It is structurally similar to other aromatic amines that cause bladder cancer in occupationally exposed workers. Since the late 1970s, MBOCA users have relied on urinary monitoring as the primary method of assessing MBOCA exposure in the workplace. This paper (1) outlines uncertainties about MBOCa's metabolism in humans that complicate interpretation of urinary MBOCA results; (2) describes alternative laboratory techniques for measuring MBOCA in urine; and (3) discusses observations from site visits concerning the practical application of urinary monitoring. Recommendations to improve the efficacy of monitoring programs for urinary MBOCA are outlined.

Animals↗
PubMed1985

Junction sequences generated by 'one-ended transposition'.

In the presence of the cognate transposase, plasmids containing a single inverted repeat (IR) sequence of Tn21 or of Tn1721 can fuse efficiently with other plasmids ('one-ended transposition'). The junctions across the sequences of donor and recipient DNA in recombinants generated by this process have been determined. These show that the segment of donor DNA starts precisely at the IR sequence (it is variable at the other end), and is flanked by a direct repeat of host DNA (usually 5bp) that was present only once in the original host sequence. These are characteristics of recombinants generated by transposition of Tn21 and Tn1721 themselves, suggesting that the mechanism of one-ended transposition is very similar to that of the corresponding entire elements.

Base Sequence↗
PubMed1984

Plasmids containing one inverted repeat of Tn21 can fuse with other plasmids in the presence of Tn21 transposase.

In the presence of the Tn21 transposase, plasmids that contain a single Tn21 inverted repeat sequence fuse efficiently with other plasmids. This reaction occurs in recA strains, is independent of the transposon-encoded resolution system, and results in insertions into different sites in the recipient plasmid. All fusion products studied contained at least one complete copy of the donor plasmid; most also contained some duplication of it as well. The data are consistent with processive models of transposition.

Base Sequence↗
PubMed1984

A genetic component in human lysosomal enzyme excretion.

Acid hydrolases are present in normal human urine in appreciable amounts. Their source appears to be lysosomes released by kidney proximal tubule epithelial cells. For a given lysosomal enzyme the total amount excreted is the product of two parameters, a general one describing the rate of lysosome secretion and a specific one describing the relative concentration of that enzyme in lysosomes. There is considerable population variation in both parameters. Studies of beta-glucuronidase, beta-galactosidase, beta-hexosaminidase, and alpha-galactosidase in monozygotic and dizygotic twins show that an appreciable part of this variation is genetic in origin. This appears to be true for both total enzyme excretion and lysosome composition. Although it was not possible to test directly whether this is also true for the rate of lysosome secretion, the fact that the two former parameters are both heritable strongly suggests that the rate of lysosome excretion is also a heritable trait. Taken together with previous data, the results suggest polygenic control of these biochemical traits. It is particularly significant that beta-glucuronidase excretion in normal individuals is a heritable trait since the excretion of this enzyme has frequently been used as a measure of normal and pathological physiological changes.

Adolescent↗
PubMed1982

The addict's perceptions of their own drug-taking: implications for the treatment of drug dependence.

The attitudes, beliefs and expectations of the addict have received surprisingly little research attention. The present study looks at the relationship between the addict's perception of their own drug taking and their behaviour in treatment. The subjects who took part in the study were receiving treatment at a London drug dependence unit: 60 were inpatients, 40 were outpatients. All completed an attitude questionnaire and a personality inventory, the EPQ). Several attitudinal differences were found between inpatient and outpatient groups, the outpatients being more generally resistant to the prospect of giving up drugs. Among the inpatients, those subjects who saw their addiction as a sort of sickness were least likely to remain in treatment. The attitude items related more clearly to the addict's behaviour in treatment than did the personality measures. The implications of these findings for the treatment of drug addicts are discussed.

Adolescent↗
PubMed1982

Absence of seasonal variation in antipyrine metabolism.

The induced activity of aryl hydrocarbon hydroxylase (AHH), measured by the metabolism of benzo[a]pyrene to fluorescent products in cultured human lymphocytes, shows a strong seasonal variation. The in vivo metabolism of antipyrine, which is also catalyzed by microsomal cytochrome P-450-dependent monooxygenases, has been reported to be correlated with AHH inducibility in human lymphocytes. To determine whether antipyrine metabolism also showed seasonal changes, we measured antipyrine half-life (t 1/2) in 10 nonsmokers and eight smokers at the two times of the year that correspond to the high and low peaks of inducible AHH activity as measured in lymphocytes. The mean antipyrine t 1/2 determined in all 18 subjects in summer was almost identical to that found in winter (mean +/- SEM = 10.90 +/- 0.65 and 10.96 +/- 0.78 hr). AHH activity in cultured human lymphocytes from the nonsmoking subjects was determined in control and 3-methylcholanthrene-induced cells to obtained inducibility ratios of 4.2 +/- 0.56 (SEM) in the summer and 1.4 +/- 0.14 (SEM) in winter. These results indicate that the seasonal variation in AHH inducibility in human lymphocytes is not reflected by a corresponding seasonal variation in antipyrine metabolism in vivo.

Adult↗