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E Ward

Publications and source records attributed to E Ward.

At least 55 records · Page 3Linked to original sources
PubMed1997

Incidence of HIV and HTLV-1 infection among sexually transmitted disease clinic attenders in Jamaica.

Of 970 sexually transmitted disease (STD) patients enrolled at the Comprehensive Health Centre, Kingston, Jamaica, between November 1990 and January 1991, 710 (73%, 333 men and 377 women) were reexamined between January 1992 and July 1993 to estimate the incidence of HIV and HTLV-I infection and to identify risk factors for infection. Of those reexamined, 20% were recruited passively when they returned to the clinic of their own accord, and 80% were recruited actively through field visits to their homes. Passively recruited persons were significantly more likely than active recruits to have had a sexually transmitted disease since enrollment or at their follow-up visit. Seven men and one woman became HIV positive during the period of follow-up. The overall HIV incidence rate was 0.7 per 100 person years (95% confidence interval [CI] = 0.3 to 1.4), 1.4 (CI = 0.6 to 2.8) for men and 0.2 (CI = 0.004 to 0.9) for women. Four of 270 men and 4 of 318 women were HTLV-I positive, an overall incidence of 0.9 per 100 person years (CI = 0.4 to 1.7), 1.0 for men and 0.8 for women. HTLV-I infection was associated with an age of 30 years or older (p < 0.01). The presumed lower transmission probability for HTLV-I may combine with a higher prevalence of HTLV-I in sexual partners to produce similar overall incidence rates for the two infections. The HIV and HTLV-I incidence rates may have been underestimated, because the study subjects who did not return to the clinic may have had a somewhat higher risk. On univariate analysis, there were significant associations between HIV infection in men and drinking alcohol before sex, cocaine use, total number of sex partners, sex with a prostitute since enrollment, ever accepting money for sex, the average number of sex partners per month, bruising during sex, and genital ulcers found on follow-up examination. This analysis needs to be interpreted with caution in view of the small number of seroconverters, which did not allow testing for independent effects in a logistic regression model.

Adult↗
PubMed1997

Proportionate mortality among unionized construction ironworkers.

This report presents the results of proportionate mortality ratios (PMR) and proportionate cancer mortality ratios (PCMR) among 13,301 members of the International Union of Bridge, Structural, and Ornamental Ironworkers who had been members for a minimum of 1 year, were actively paying dues into the death beneficiary fund, and had died between 1984-1991. Using the United States proportionate mortality rates as the comparison population, statistically significant elevated risks, using 95% confidence intervals (CI), were observed for several types of injuries: falls (N = 259, PMR = 3.57, CI = 3.15-4.03), transportation injuries (N = 363, PMR = 1.22, CI = 1.10-1.35), and other types of injuries (N = 225, PMR = 1.63, CI = 1.43-1.86). The deaths due to falls were significantly elevated for each 10-year age group under age 60 (PMR > 7.00) and for those workers with < 20 years in the union (PMR > 6.00). Elevated mortality risks were also observed for all malignant neoplasms combined (N = 3,682, PMR = 1.09, CI = 1.06-1.13) as well as for site-specific malignant neoplasms of the lung (N = 1,523, PMR = 1.28, CI = 1.21-1.35), pleural mesothelioma (N = 7, PMR = 1.67, CI = 0.67-3.44) and "other and unspecified sites" (N = 307, PMR = 1.29, CI = 1.15-1.44). The category "pneumoconiosis and other respiratory diseases" was also significantly elevated (N = 690, PMR = 1.11, CI = 1.03-1.20); in this category, deaths due to asbestosis had the greatest elevated risk (N = 10, PMR = 3.56, CI = 1.70-6.54). No elevation in risk was found for kidney cancer or for chronic nephritis which were of interest because of Ironworkers' potential exposure to lead. The present study underscores the importance of fall protection and other injury prevention efforts in the construction industry, as well as the need to control airborne exposures to asbestos, welding fumes and other respirable disease hazards.

Accidents, Occupational↗
PubMed1997

Mechanosensitive expression of a lipoxygenase gene in wheat.

Touch stimulation of wheat (Triticum aestivum L.) seedlings led to a strong and dose-dependent increase in the level of lipoxygenase mRNA transcripts. The touch-induced response occurred within 1 h and was transient. A similar response was observed after wind treatment and wounding. The mechanical strain-regulated lipoxygenase might translate mechanical strain into lipoxygenase pathway-dependent growth responses.

Amino Acid Sequence↗
PubMed1997

A comparison of prevalence rates of genital ulcers among persons attending a sexually transmitted disease clinic in Jamaica.

Two cross-sectional surveys were undertaken, from December 1982 to August 1983 and from November 1990 to January 1991, to estimate the prevalence rates of genital ulcer disease (GUD) in all patients presenting with a new sexually transmitted disease (STD) complaint to the STD clinic at the Comprehensive Health Centre in Kingston, Jamaica. Diagnosis of syphilis and human immunodeficiency virus (HIV) infection was based on results of laboratory tests, but diagnosis of the other STDs was based on clinical features. Data from these two surveys were compared, and reported national annual incidence data for GUD reviewed. In 1982/83 6.8% of 23,050 patients had GUD, men (9.3%) more often than women (4.2%; p < 0.001). In 1990/91 the prevalence rate was 12.8%, with increased rates for both men (18.2%) and women (6.8%; p < 0.001). In patients with GUD, a clinical diagnosis of genital herpes was made, in 1982/83 and 1990/91, respectively, in 16.8% and 7.8% of the patients; syphilis, in 12.9% and 18.8%; chancroid, in 12.4% and 13.3%; viral warts, in 5.7% and 6.3%; lymphogranuloma venereum, in 4.1% and 3.9%; and granuloma inguinale, in 3.6% and 2.3%. In men the rate for syphilis was 19% in 1990/91 and 8% in 1982/83 (p = 0.001); and for genital herpes it was 7% in 1990/91 and 17% in 1982/83 (p = 0.025). These reversals were attributed to intense media coverage of herpes in 1982/83. There was no difference in prevalence rates between the two surveys for these diseases in women, or for lymphogranuloma venereum, granuloma inguinale and genital warts in men and women. A clinical diagnosis could not be made in 44.4% of cases in 1982/83 (particularly in men), and in 47.6% of cases in 1990/91. GUDs facilitate transmission and adversely affect the prognosis of HIV. The increase in their prevalence has implications for the evolution of the local HIV epidemic, and should be addressed effectively by strengthening the STD/HIV control programme.

Chancroid↗
PubMed1996

The mode of action and the structure of a herbicide in complex with its target: binding of activated hydantocidin to the feedback regulation site of adenylosuccinate synthetase.

(+)-Hydantocidin, a recently discovered natural spironucleoside with potent herbicidal activity, is shown to be a proherbicide that, after phosphorylation at the 5' position, inhibits adenylosuccinate synthetase, an enzyme involved in de novo purine synthesis. The mode of binding of hydantocidin 5'-monophosphate to the target enzyme was analyzed by determining the crystal structure of the enzyme-inhibitor complex at 2.6-A resolution. It was found that adenylosuccinate synthetase binds the phosphorylated compound in the same fashion as it does adenosine 5'-monophosphate, the natural feedback regulator of this enzyme. This work provides the first crystal structure of a herbicide-target complex reported to date.

Adenylosuccinate Synthase↗
PubMed1996

Risk of low red or white blood cell count related to estimated benzene exposure in a rubberworker cohort (1940-1975)

This study evaluated the relationship between benzene exposure and low white blood cell (WBC) and red blood cell (RBC) counts. Hematologic screening data collected over a 35 year period at a rubber hydrochloride manufacturing plant were analyzed; an increased risk of leukemia had been demonstrated previously among workers at the plant [Infante et al. (1977).' Lancet 2:76-78; Rinsky et al. (1981): Am J Ind Med 2:217-45 (1987): NEJM 316:1044-1050/. Hematologic screening data were available for 657 of 1,037 (63.3%) individuals employed at the plant from 1939 through 1976. There was a total of 21. 710 blood test records (range per individual 1-354). The study utilized a case-control design and estimated benzene exposures using the job exposure matrix developed by Rinsky et al. (1987): NEJM 316:1044-1050]. The effects of benzene exposure in the 30, 90, and 180 days before the blood test date, as well as cumulative exposure up until the blood test date, were examined using conditional logistic regression. For WBCs there was a strong exposure response and all of the exposure metrics selected showed a significant relationship with low blood count. For RBCs there was a weak positive exposure-response, which was significant (p = 0.03) for one of the dose metrics. The finding of an exposure-response relationship in the range of exposures represented in this study, where the maximum daily benzene exposure estimate was 34 ppm, is consistent with findings of several animal studies demonstrating a decrease in peripheral lymphocyte counts at benzene exposures as low as 10 ppm, and a stronger effect of benzene exposure on lymphocytes (as reflected in total WBC count) than on red cells. There was no evidence for a threshold for the hematologic effects of benzene exposure, suggesting that even exposure to relatively low levels of benzene (e.g., <5 ppm) may result in hematologic suppression.

Benzene↗
PubMed1996

Benzothiadiazole, a novel class of inducers of systemic acquired resistance, activates gene expression and disease resistance in wheat.

Systemic acquired resistance is an important component of the disease resistance repertoire of plants. In this study, a novel synthetic chemical, benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH), was shown to induce acquired resistance in wheat. BTH protected wheat systemically against powdery mildew infection by affecting multiple steps in the life cycle of the pathogen. The onset of resistance was accompanied by the induction of a number of newly described wheat chemically induced (WCI) genes, including genes encoding a lipoxygenase and a sulfur-rich protein. With respect to both timing and effectiveness, a tight correlation existed between the onset of resistance and the induction of the WCI genes. Compared with other plant activators, such as 2,6-dichloroisonicotinic acid and salicylic acid, BTH was the most potent inducer of both resistance and gene induction. BTH is being developed commercially as a novel type of plant protection compound that works by inducing the plant's inherent disease resistance mechanisms.

Amino Acid Sequence↗
PubMed1995

Evidence for cross-pathway regulation of metabolic gene expression in plants.

In Arabidopsis thaliana, blocking histidine biosynthesis with a specific inhibitor of imidazoleglycerol-phosphate dehydratase caused increased expression of eight genes involved in the biosynthesis of aromatic amino acids, histidine, lysine, and purines. A decrease in expression of glutamine synthetase was also observed. Addition of histidine eliminated the gene-regulating effects of the inhibitor, demonstrating that the changes in gene expression resulted from histidine-pathway blockage. These results show that plants are capable of cross-pathway metabolic regulation.

Arabidopsis↗
PubMed1995

Risk factors for HTLV-I among heterosexual STD clinic attenders.

Human T-cell lymphotropic virus type 1 (HTLV-I) status was assessed in 994 patients attending a sexually transmitted disease (STD) clinic in Kingston, Jamaica, between November 1990 and January 1991 for a new STD complaint. Of 515 heterosexual men, 36 (7.0%) were HTLV-I seropositive, as were 38 (7.9%) of 479 women. HTLV-I seroprevalence increased with age in women. A history of blood transfusion was associated with HTLV-I in both sexes, significantly so in men [odds ratio (OR) 4.7, confidence interval (CI) 1.1-17 for men; OR 1.9, CI 0.6-5.0 for women]. Further analysis excluded all persons reporting a transfusion. On multiple logistic regression analysis, independent associations with HTLV-I infection in men were shown for marital status (OR 3.5, CI 1.2-10 for married/common law vs. single/visiting unions), agricultural occupation (OR 9.0, CI 2.0-41), bruising during sex (OR 2.9, CI 1.0-8.1), > or = 15 years at first sexual intercourse (OR 2.9, CI 1.0-8.2), and a positive test for hepatitis B surface antigen (OR 7.3, CI 1.2-52). In women, associations were shown for two or more sex partners in the 4 weeks prior to complaint (OR 4.9, CI 1.8-13), 11 or more lifetime sexual partners (OR 5.9, CI 1.3-27), aged < 15 years at first sexual intercourse (OR 2.3, 1.0-5.4), bruising during sex (OR 2.7, CI 1.1-6.6), microhaemagglutination-Treponema pallidum positivity (OR 3.6, CI 1.6-8.4), and human immunodeficiency virus infection (OR 14, CI 2.1-92).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Management of vaginal discharge in women treated at a Jamaican sexually transmitted disease clinic: use of diagnostic algorithms versus laboratory testing.

The management of cervical infections is difficult in developing countries because laboratory facilities for diagnosing these infections are seldom available; therefore, syndrome-based management has been recommended by the World Health Organization (WHO). However, such alternative approaches need to be evaluated in real field settings. We used algorithms (flowcharts) for syndromic management of abnormal vaginal discharge to treat 752 women who presented at a Jamaican sexually transmitted disease (STD) clinic. Laboratory testing revealed cervical infection (gonococcal and/or chlamydial) in 34% of these women; trichomoniasis was documented for 25%; and at least one STD was documented for 54% of the women. Use of a clinical algorithm for diagnosing cervical infection was 73% sensitive (95% CI, 67-78) and 55% specific (95% CI, 49-62) when compared with laboratory testing. The risk-assessment-inclusive flowchart developed by WHO was 84% sensitive (95% CI, 80-89) and 40% specific (95% CI, 34-46) for diagnosing cervical infection. Positive predictive values for diagnosing cervical infection with use of the algorithms ranged from 42% to 43%, and negative predictive values ranged from 78% to 81%. The sensitivity of the algorithms for diagnosing trichomoniasis ranged from 85% to 88%. To treat as many infected women as possible, the most sensitive algorithm was selected for routine use in Jamaican STD clinics.

Adult↗
PubMed1995

The HIV/AIDS epidemic in Jamaica.

OBJECTIVE: To describe the HIV/AIDS epidemic in Jamaica. METHODS: Data from the national surveillance system for HIV infection and AIDS based in the Epidemiology Unit, Ministry of Health, were reviewed. These include case reports; HIV screening of blood donors, migrant farmworkers and US visa applicants; sentinel surveillance among antenatal clinic (ANC) attenders and sexually transmitted disease (STD) clinic attenders; and various serosurveys. RESULTS: A total of 669 AIDS cases were reported in Jamaica from December 1993 representing a cumulative AIDS case rate of 28 per 100,000 population. Since 1987 the annual AIDS case rate doubled every 2 years with 69% of individuals having died with AIDS. Heterosexual transmission predominates with the cumulative adult AIDS male-to-female case ratio declining from 2.8:1 in 1988 to 1.9:1 in 1993. A total of 55 children with AIDS account for 8.2% of all cases. The HIV infection rate per 1000 in 1993 was 3.8 among blood donors, 1.4 among ANC attenders and significantly higher among STD clinic attenders (men 6%, women 2.7%), homosexuals (9.6%), female prostitutes (12%) and individuals with repeat STD infections (10%). Consistent condom use increased from 27% in 1989 to 47% in 1993. CONCLUSIONS: HIV infection was introduced into Jamaica from abroad through several different routes including the Jamaican homosexual community, migrant farmworkers, female prostitutes, and informal commercial importers. HIV transmission is well established locally and is spreading more rapidly in Western Jamaica and along the North Coast, which may reflect increased sexual activity associated with tourism. Although awareness of AIDS and HIV is high and condom use has increased considerably, there are no grounds for complacency concerning the HIV/AIDS epidemic in Jamaica.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Insect cell expression of recombinant imidazoleglycerolphosphate dehydratase of Arabidopsis and wheat and inhibition by triazole herbicides.

Imidazoleglycerolphosphate dehydratase (IGPD; EC 4.2.1.19), which is involved in the histidine biosynthetic pathway of Arabidopsis thaliana and wheat (Triticum aestivum), has been expressed in insect cells using the baculovirus expression vector system. N-terminal amino acid sequencing indicated that recombinant IGPDs (rIGPDs) were produced as mature forms via nonspecific proteolytic cleavages in the putative transit peptide region. The wheat rIGPD contained one Mn atom per subunit, and the Mn was involved in the assembly of the subunits to form active IGPDs. Protein-blotting analysis, using antibodies raised against the wheat rIGPD, indicated that IGPD was located in the chloroplasts of wheat. The rIGPDs of Arabidopsis and wheat, which were 86% identical in their primary structures deduced from the cDNAs, exhibited similar properties in terms of the molecular mass, pH optimum, and the Km for the substrate, imidazoleglycerolphosphate. However, the nonselective herbicides 3-amino-1,2,4-triazole and a newly synthesized triazole [(1R*, 3R*)-[3-hydroxy-3-(2H-[1,2,4]triazole-3-yl)-cyclohexyl]- phosphonic acid], inhibited Arabidopsis and wheat IGPDs in a mixed-type and a competitive manner, respectively.

Amino Acid Sequence↗
PubMed1995

Overview of preventable industrial causes of occupational cancer.

This paper summarizes what is known about preventable causes of occupational cancer, including single agents, complex mixtures, and broad occupational associations. Epidemiologic methods have been very successful in documenting cancer risks associated with single agents. Epidemiologic data are most conclusive when an exposure-response relationship can be demonstrated. Examples of agents for which epidemiologic studies provide evidence of an exposure-response relationship include benzene and (concurrent exposure to) ortho-toluidine and aniline. Vinyl chloride and bischloromethyl ether are examples of associations between single agents and rare histologic types of cancer. It is more difficult to conduct epidemiologic studies to identify cancer risks associated with complex mixtures. Studies of diesel exhaust and lung cancer and metal machining oils are cited as having employed advanced industrial hygiene and epidemiologic methods for studies of complex mixtures. Elevated cancer risks have also been identified in broad occupational groups, including painters and dry cleaners. Epidemiologic case-control studies are often used to detect such associations but are limited in their abilities to detect the causal agents. Major gaps exist in knowledge of occupational cancer risks among women workers and workers of color. Because epidemiologic research measures illness and mortality that have already occurred, a positive study can be interpreted to represent a failure in prevention. The challenge we face in the next decade is to identify interventions earlier in the causal pathway (toxicologic testing, biomarkers of exposure or precancerous changes, institution of engineering and good industrial hygiene practices to reduce occupational exposure levels) so that occupational cancer can be prevented.

Carcinogens↗
PubMed1995

Induction of cytochrome P450 genes by ethanol in maize.

Ethanol treatment of etiolated maize seedlings led to a marked enhancement in metabolism of the herbicides metolachlor and prosulfuron. cDNA clones representing eight genes that encode putative cytochrome P450 enzymes were isolated from maize. They fall into three families and are designated CYP71C5, CYP73A6, A7, and A8, and CYP81A1, A2, A3, and A4. Ethanol treatment induced the CYP81A subfamily at the mRNA level in both roots and shoots of etiolated seedlings.

Acetamides↗
PubMed1994

Wheat acetyl-coenzyme A carboxylase: cDNA and protein structure.

cDNA fragments encoding part of wheat (Triticum aestivum) acetyl-CoA carboxylase (ACC; EC 6.4.1.2) were cloned by PCR using primers based on the alignment of several biotin-dependent carboxylases. A set of overlapping clones encoding the entire wheat ACC was then isolated by using these fragments as probes. The cDNA sequence contains a 2257-amino acid reading frame encoding a 251-kDa polypeptide. The amino acid sequence of the most highly conserved domain, corresponding to the biotin carboxylases of prokaryotes, is 52-55% identical to ACC of yeast, rat, and diatom. Identity with the available C-terminal amino acid sequence of maize ACC is 66%. The biotin attachment site has the typical eukaryotic EVMKM sequence. The cDNA does not encode an obvious chloroplast targeting sequence. Various cDNA fragments hybridize in Northern blots to a 7.9-kb mRNA. Southern analysis with cDNA probes revealed multiple hybridizing fragments in hexaploid wheat DNA. Some of the wheat cDNA probes also hybridize with ACC-specific DNA from other plants, indicating significant conservation among plant ACCs.

Acetyl-CoA Carboxylase↗
PubMed1994

Salicylic acid as a signal molecule in plant-pathogen interactions.

Significant insight has been gained in the past year into the roles of salicylic acid (SA) in plant-pathogen interactions. The ability to accumulate SA has been shown to be essential for systemic acquired resistance in tobacco plants. Further experiments have shown that SA is apparently not a systemic, vascular-mobile signal, but rather is required for signal transduction at the local level. Its mode of action may include inhibition of catalase activity, leading to increased levels of hydrogen peroxide.

Bacteria↗