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Biomedical subjects

D Baird

Publications and source records attributed to D Baird.

At least 19 recordsLinked to original sources
PubMed2006

Response of meiofauna and nematode communities to increased levels of contaminants in a laboratory microcosm experiment.

This study was undertaken to assess the response of meiofauna and nematode (multispecies) associations in terms of density, diversity, and composition to different environmental contaminants and also to evaluate the use of meiofauna and nematodes as indicators in pollution monitoring. Sediment was collected from the mouth of the Swartkops River estuary and defaunated by successive freezing and thwarting. The sediment was then subdivided into flasks and treated with different contaminants (organic carbon, Zn, Cu, Pb, Fe) at different concentrations, before meiofauna-rich sediment was added to each of them. The setup was allowed to mature for 32 days. Various biological indices were used to assess the biological status of the nematode communities in the laboratory experiment. Nematode identification was done to the genus level. The results indicate that higher concentrations of heavy metals and organic carbon had an impact on the nematode density, diversity, and community structure. Nematode genera such as Axonolaimus, Theristus, and Paramonohystera were found to be tolerant to metal pollution. This study also observed that nematode communities react differently to metal and organic pollution.

Animals↗
PubMed2006

[Role of FSH and LH in follicle development].

Much of the research into the physiology of the ovary has concentrated on the terminal stages of follicle development, and as a result, our knowledge of the endocrine, paracrine, and autocrine mechanisms regulating antral follicle development is extensive. In contrast, our knowledge of the factors controlling the initiation and development of earlier follicles is limited, particularly in monovular species such as large domestic ruminants and humans in whom it takes several months for follicles to progress from initiation to the antral stage. This study summarizes recent data concerning the factors controlling the initiation and development of follicles from the primordial through the preovulatory stage of development.

Animals↗
PubMed2005

Evaluation of the susceptibility of the cultured shrimp Litopenaeus vannamei to vibriosis when orally exposed to the insecticide methyl parathion.

The causes of disease in cultured shrimp are difficult to ascertain but there is evidence that disease is correlated with environmental factors. Crustaceans are particularly sensitive to insecticides due to their close phylogenetic relationship with insects. The objective of this study was to investigate whether there was an increased susceptibility of the shrimp Litopenaeus vannamei to Vibrio parahaemolyticus, when exposed to methyl parathion. The outline of the study was the following: An LC50 96 h was determined to methyl parathion orally offered to juvenile shrimp. Further experiments were carried out in order to determine a concentration that affected the shrimp (verified by measuring the acethylcholinesterase activity) while producing minimal mortalities. This sublethal concentration was used in a susceptibility experiment where methyl parathion was offered to shrimp which were later injected with V. parahaemolyticus in a dose expected to kill less than 15%. Probit analysis estimated a 96 h median lethal concentration (LC50) of 1.56 microg g(-1). Mortality and AChE activity showed a concentration-response relationship in the exposure treatments. The median inhibitory concentration (IC50) determined was 0.029 microg g(-1). These results suggested that a concentration of 0.1 microg g(-1) was appropriate for the bacteria-pesticide interaction test as it was able to elicit 11.1% mortality after 10 days of exposure, while producing an AChE inhibition of 57.12%. Cumulative mortalities were significantly increased (P<0.01) in the treatment that combined exposure to methyl parathion and V. parahaemolyticus (35.19%) in comparison with methyl parathion or V. parahaemolyticus alone (9.26% and 7.41%, respectively).

Acetylcholinesterase↗
PubMed2005

Uraba lugens (Lepidoptera: Nolidae) in New Zealand: pheromone trapping for delimitation and phenology.

A synthetic sex pheromone trapping survey of the leaf skeletonizer Uraba lugens Walker (Lepidoptera: Nolidae) demonstrated the unexpectedly widespread distribution of the insect across > 40,000 ha of urban Auckland, New Zealand. A survey of eucalyptus trees planted in parks and other public areas showed a significant spatial correlation between trap catch and breeding populations, validating the trap survey results. Traps in trees showing damage had four-fold higher catches than traps placed in undamaged or nonhost trees, and < 1% of damaged trees with traps failed to catch adult moths. Damage by larval feeding was correlated with male trap catch in the previous generation, offering good prospects for a pest management decision support system, provided that an economic threshold is developed. Catches increased by 3.4-fold in the same georeferenced trapping grid between November and December 2003 and between March and April 2004 across two generations, over the summer. A vertical transect showed that catches increased with height up to the top trap at 13 m (60% of mean tree height). Options for managing the insect will need to overcome the high rate of increase, the rate of spread, and the vertical distribution of the insect on tall eucalyptus trees.

Animals↗
PubMed2003

Assessing socio-economic factors in relation to stigmatization, impairment status, and selection for socio-economic rehabilitation: a 1-year cohort of new leprosy cases in north Bangladesh.

The current leprosy elimination strategy focuses almost exclusively on delivery of leprosy diagnostic services and multi-drug treatment (MDT). However, the specific problems of people newly diagnosed with leprosy or cured with MDT primarily relate to impairment of nerve function and social and economic consequences of the diagnosis of leprosy. This study was carried out to investigate the relation between socio-economic factors and the development of nerve impairments and stigma. In addition the relation between socio-economic factors and selection for socio-economic assistance was studied. The study population was a cohort of 2364 newly diagnosed people with leprosy in rural Bangladesh in 1996, including 42.5% women, with an overall mean age of 31.4 years. Three hundred and sixty people (15.2%) had WHO grade 1 or 2 disability identified at diagnosis, and 50 (2.1%) had stigma identified on interview at home visit conducted within one month of diagnosis. One hundred and eighty-eight people (8%) were selected for specific assistance for rehabilitation, primarily interest-free loans for income generating activities or vocational training. Factors independently associated with WHO grade 1 or 2 disability at diagnosis were multibacillary (MB) classification, adult status, and manual occupations. Smear positivity, female sex, and the presence of dependents were associated with an increase in the experience of stigma. The presence of nerve impairments and stigma, as well as several indices of poverty were clearly associated with selection for inclusion in an integrated program for socio-economic assistance. An increased focus by leprosy services on the socio-economic factors associated with poorer physical and social outcomes is recommended. Where adequate finances and trained staff are available, efforts could be made to identify those at higher risk of poor outcomes, and to provide or to mobilize appropriately targeted socio-economic interventions.

Adolescent↗
PubMed2001

The importance of definitions and methods in surgical wound infection audit.

We investigated the value of a full-time audit nurse personally following up every patient from admission to 30 days postoperatively in order to obtain accurate surgical wound infection rates. Our results show that this type of audit is an effective, although time-consuming, way of collecting accurate data on wound infection rates. It enabled the early identification of problem areas in practice and facilitated the adoption of evidence based practice. As a result of the audit there was a significant reduction in the clean wound infection rate from 13.9% in November 1995 to 7.9% in March 1998 (P= 0.05).

Aftercare↗
PubMed2001

Protective effect of pregnancy for development of uterine leiomyoma.

Many factors that can modulate the risk of developing uterine leiomyoma have been identified, including parity. Epidemiological data on decreased risk of developing this disease has been subject to different interpretations regarding whether pregnancy per se is protective or, as leiomyomas are a major cause of infertility, women that develop these tumors are less fertile and thus have lower pregnancy rates. We have utilized an animal model genetically predisposed to uterine leiomyoma to investigate the potential protective effect of pregnancy on the risk of developing this disease. Female Eker rats that carry a mutation in the tuberous sclerosis 2 (Tsc-2) tumor suppressor gene develop uterine leiomyoma with a frequency of 65% when nulliparous. These animals were bred with intact or vasectomized males and tumor incidence determined after a single pregnancy (to confirm fertility) or multiple pregnancies over the lifetime of the animals. Females with multiple litters displayed a dramatic shift in tumor incidence and presentation. Tumor incidence decreased from 71% in single litter females to 10% in females that had multiple litters (average: five litters/animal). Interestingly, females bred with vasectomized males also exhibited a reduced tumor incidence of 41%, suggesting that the hormonal changes associated with early stages of pregnancy that occur in pseudopregnant females may have contributed to the protective effect of pregnancy.

Animals↗
PubMed1998

The effects of self-administering emergency contraception.

BACKGROUND: Emergency postcoital contraception prevents pregnancy, but it must be prescribed by a doctor and taken within 72 hours of intercourse. It has been proposed that emergency contraception be made available without a prescription. We undertook a study to learn how women might behave if given a supply of emergency contraceptive pills to keep at home. METHODS: We assigned 553 women to be given a replaceable supply of hormonal emergency contraceptive pills to take home (the treatment group) and 530 women to use emergency contraception obtained by visiting a doctor (the control group). The frequency of use of emergency contraception, the use of other contraceptives, and the incidence of unwanted pregnancy were determined in both groups of women one year later. RESULTS: The results for 549 women in the treatment group and 522 women in the control group were available for analysis. Three hundred seventy-nine of the women in the treatment group (69 percent) and 326 of the women in the control group (62 percent) contributed detailed information at follow-up. One hundred eighty of the women in the treatment group (47 percent) used emergency contraception at least once. Among those who returned the study questionnaire, 98 percent used emergency contraception correctly. There were no serious adverse effects. Eighty-seven women in the control group (27 percent) used emergency contraception at least once (P<0.001 for the comparison with the treatment group). The women in the treatment group were not more likely to use emergency contraception repeatedly. Their use of other methods of contraception was no different from that of the women in the control group. There were 18 unintended pregnancies in the treatment group and 25 in the control group (relative risk, 0.7; 95 percent confidence interval, 0.4 to 1.2). CONCLUSIONS: Making emergency contraception more easily obtainable does no harm and may reduce the rate of unwanted pregnancies.

Adolescent↗
PubMed1997

Differences between men and women in dual-diagnosis treatment.

The authors reviewed the charts of all women and a randomly selected sample of men over a 6-month period on two addiction treatment units at Bellevue Hospital Center in New York. The men were more likely to be admitted with schizophrenia and to have used substances of abuse other than alcohol, and the women were more likely to be admitted with affective disorders. Also, the women on the dual-diagnosis ward were more likely to be domiciled (i.e., not homeless), and the women on both units were significantly more likely to report having been crime victims. These findings suggest that dually diagnosed women need a substantially different treatment paradigm from men.

Adult↗
PubMed1996

The Pathogenicity of Serratia Strains to Lucilia sericata (Diptera: Calliphoridae)

Adult blowflies, Lucilia sericata, were tested for susceptibility to 11 strains of Serratia marcescens, 2 strains of Serratia liquefaciens, and 1 strain of Serratia entomophila in a series of 14 laboratory bioassays. Most bacterial strains were initially isolated from insects. S. marcescens strains were characterized to biotype level. Most strains conformed to biotype A2a, the group most commonly associated with insects. Flies were held individually in small tubes and fed bacterial suspensions containing approximately 1 x 10(9) bacteria ml-1 in a single 24-hr feeding period. For the remainder of the experiment, flies were fed sucrose solution. Eight of the S. marcescens strains caused significant mortality (P < 0.05-0.001), measured as death rate compared to untreated flies. Four strains had no effect on the flies (P > 0.05). The time taken to reach 50% mortality (LT50) ranged from 6.38 to 7.49 days for the pathogenic S. marcescens strains compared to LT50s of 8.81-11.73 days for the nonpathogenic strains, which did not differ significantly from the untreated control flies (LT50 of 10.38 days). After 7 days, mortality caused by the pathogenic strains ranged from 21 to 45% of treated insects. One strain of S. liquefaciens also caused significant mortality while the other was nonpathogenic. No mortality resulted from treatment of flies with S. entomophila.

Journal Article↗
PubMed1994

Cancer and noncancer risk to women in agriculture and pest control: the Agricultural Health Study.

The Agricultural Health Study is a collaborative effort involving the National Cancer Institute, the US Environmental Protection Agency, and the National Institute of Environmental Health Sciences. A goal of this investigation is to establish a large cohort of men and women that can be followed prospectively for 10 years or more to evaluate the role of agricultural exposures in the development of cancer, neurologic disease, reproductive difficulties, childhood developmental problems, and other chronic diseases. The study also will provide an opportunity to assess the role that diet, cooking methods, and other lifestyle factors have on the cause of cancer and other diseases. The cohort will be composed of approximately 112,000 adult study subjects, including 42,000 women, making this one of the largest cohorts of women ever assembled for an epidemiologic investigation of environmental and occupational exposures. Children of farm families also will be enrolled. The study will be conducted in Iowa and North Carolina. Enrollment will begin in December 1993 and continue for 3 years.

Adult↗