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Biomedical subjects

T Watts

Publications and source records attributed to T Watts.

At least 37 records · Page 2Linked to original sources
PubMed1999

Variation of pesticide concentration in sheep dips operated according to traditional and revised methods.

OBJECTIVE: To quantify stripping in traditional dipping operations and to revise dipping methods, based on prediction of stripping so that a more stable concentration of pesticide in the dipwash is achieved. DESIGN AND METHODS: Plunge and shower dips were operated sequentially according to traditional and revised dipping instructions. Dips were operated by continuous and intermittent replenishment. Samples of mixed dipwash were collected periodically and assayed for pesticide (diazinon) concentration. RESULTS: Diagrammatic representations of pesticide concentration versus number of sheep dipped indicated traditional dipping leads to wide variations in the concentration of pesticide in dipwash during dipping. Intermittent replenishment led to a 'saw-tooth' pattern in the pesticide concentration. Traditional continuous replenishment (using the starting concentration of pesticide) indicated both the rate and extent of stripping was higher in shower dipping. If sufficient sheep were dipped, equilibrium was reached between the rate of pesticide replenishment and removal. An alternative method of dip operation by continuous replenishment, using a low starting concentration of pesticide and a replenishment concentration high enough to offset the pesticide loss through stripping resulted in a more stable concentration of pesticide in the dip. CONCLUSION: Revision of dipping instructions can lead to exposure of sheep to stable concentrations of stripping pesticide during dipping.

Administration, Topical↗
PubMed1998

Water hyacinths.

Explore the source record for details and available documents.

Africa↗
PubMed1998

A re-audit of pulmonary function laboratories in the West Midlands.

In 1991 the West Midlands Pulmonary Function Audit Group examined the consistency between pulmonary function laboratories in the West Midlands. Three healthy subjects visited 22 centres and performed a standard set of pulmonary function tests. Demographic data on nine hypothetical subjects was also supplied for the laboratories to produce predicted values. Equipment was checked for accuracy using standard methods. The 1991 audit revealed significant inter-laboratory variability. Sources of error were identified and after consultation, recommendations were made to improve consistency. In addition, national and regional training workshops were organized for laboratory staff. In 1995 the audit was repeated using the same three subjects. Significant differences continued for all predicted results except for residual volume (RV) and forced vital capacity (FVC) and for all measured results except for functional residual capacity (FRC). However, improvements in the coefficient of variation were seen compared with 1991 for predicted forced expiratory volume (FEV1), total lung capacity (TLC), gas transfer (TLCO), FVC, FRC and RV. Similar improvements were seen in measured results for FEV1 and FVC. Increased variation was seen for predicted corrected transfer factor (KCO) and actual RV. The majority of variables in the 1995 audit had a coefficient of variation of less than 5% between laboratories. Analysis of the predicted results from the hypothetical subjects continued to show unacceptable variation reflecting continuing computer algorithm inconsistency. The improvements seen are encouraging and suggest that a regular audit programme is worthwhile.

Adult↗
PubMed1998

Intradermal immunization with a bovine herpesvirus-1 DNA vaccine induces protective immunity in cattle.

Although intramuscular (i.m.) injection of DNA encoding glycoprotein D (gD) of bovine herpesvirus-1 (BHV-1) induces immune responses in cattle, this route of delivery is inefficient. Here we assessed three parameters that may enhance the efficacy of a gD DNA vaccine in cattle. First, the immune response generated by i.m. injected plasmid expressing a secreted form of gD (tgD) was determined and found to be very similar in magnitude to the response induced by gD-expressing plasmid. Secondly, gD- and tgD-expressing plasmids were administered by intradermal (i.d.) immunization, which resulted in a superior immune response to the secreted form, but no improvement in the response to the membrane-associated form. However, the form of gD used for immunization did not influence the immunoglobulin subtype, the ratio of antigen-specific IgG1 to IgG2 being approximately 4:1. Finally, the effect of promoter strength was assessed by replacing the Rous sarcoma virus (RSV) promoter, which was used in the original experiments, with the human cytomegalovirus immediate early promoter and first intron A (HCMV/IA). Although upon transfection in vitro the HCMV/IA promoter appeared to be stronger than the RSV promoter, there was only a 2-fold higher antibody response in vivo upon i.d. injection of cattle. Protection against virus challenge was obtained in the calves immunized i.d. with tgD-encoding plasmid, as shown by a significant reduction in weight loss, virus excretion, temperature response and clinical disease. No significant protection was observed in the animals vaccinated i.d. with the gD-expressing plasmid, which correlates with the lower level of immunity pre-challenge.

Animals↗
PubMed1997

Cancer of the skin in Zimbabwe: an analysis based on the Cancer Registry 1986 to 1992.

OBJECTIVES: To determine whether skin cancers are increasing. DESIGN: Cancer Registry series. SETTING: Cancer Registry Office in Harare, Zimbabwe. This registry serves the referral hospitals in Harare and Bulawayo. SUBJECTS: All cancer patients (9,029 males, 8,730 females) notified from 1986 to 1992. MAIN OUTCOME MEASURE: Proportion of skin cancer to the total cancers notified. RESULTS: The limitations of the Cancer Registry were noted. In Black Zimbabweans, skin cancers increased from 381 (11% of all notifications) in 1986 to 1,346 (29.7% of all notifications) in 1992. The increase was due to an increase in Kaposi's sarcoma in both men and women although the number notified in women was a quarter of that notified in men. In White Zimbabweans, there was a significant increase in basal cell carcinoma in men and this cancer increased with age from 6.52 per 1,000 population in people 30 to 54 years to 25.04 per 1,000 in those over 54 years of age. CONCLUSION: Our findings show that the number of people with skin cancers is on the increase probably due to the AIDS epidemic and also the aging of the White population, with implications for the demand for health care for treating these cancers in a health service working on a very tight budget.

Adult↗
PubMed1997

Housing conditions in a high density town near Harare, Zimbabwe.

OBJECTIVES: To determine the living conditions of people and to compare the results with census figures. DESIGN: Cross sectional. SETTING: A high density dormitory suburb of Harare, Zimbabwe. SUBJECTS: 108 stands containing 293 households were surveyed in 1990 and 90 stands containing 454 households in 1993. MAIN OUTCOME MEASURE: Crowding index. RESULTS: An average increase of five people per stand in the three years to an average of 15 to 18 people on each stand was observed, allowing 16.4 to 19.6 m2 per person. Although the number of households living in one room increased from 101 (48.6%) in 1990 to 243 (72.5%) in 1993, the actual number of people per room did not increase. The Chitungwiza population was older than the overall population in Zimbabwe with an increased proportion of men of working age. About one tenth (10.8%) of heads of households who were resident for more than 20 years were still lodgers and 77.0% of these heads of households maintained that they still had a rural home. About three quarters (76.4%) of households had no kitchen and 74.1% of all households cooked on paraffin stoves or occasionally wood fires. CONCLUSION: Many new rooms had been built on the stands leading to overcrowding with possible implications for health.

Adolescent↗
PubMed1995

An audit of pulmonary function laboratories in the West Midlands.

BACKGROUND: Pulmonary function testing has become an integral part of the assessment and follow-up of patients with pulmonary disease. Many factors can influence the results produced by a laboratory. This audit was performed to examine the extent of variation in the pulmonary function test results amongst all laboratories in the West Midlands. This was followed by an attempt to determine the cause of this variation. METHODS: Phase 1. Three normal healthy subjects each underwent a set of pulmonary function tests in all 22 laboratories in the West Midlands. Information regarding technicians' qualifications, training and seniority, protocol and equipment used were obtained in the form of a questionnaire. Phase 2. All 22 laboratories were asked to calculate the predicted values on the same nine sets of demographic data. These data included both sexes, ethnic minorities and range of ages. In addition technical aspects of each laboratory were investigated including the assessment of volume and gas analysers with standard gases containing known concentrations of helium and carbon monoxide. RESULTS: Phase 1. Significant variations (P < 0.05) were observed in all measured values of pulmonary function tests of the three subjects. Significant variations (P < 0.05) were also observed in all predicted values except total lung capacity. Phase 2. There were significant variations (P < 0.05) amongst laboratories in calculating the predicted values of all components of pulmonary function tests. No significant differences were observed in the measurement of volume or concentration of carbon monoxide or helium.

Adult↗
PubMed1995

Postnatal depression. Facilitating peer group support.

Health visitors and lay people have been working together in Maidenhead to support women suffering from postnatal illness. Alison Jones, Tricia Watts and Sybil Romain describe how the group supplements medical and psychiatric services, by tackling the isolation women with postnatal depression can feel, and helping them through until the illness ends.

Community Health Nursing↗
PubMed1990

Children in an urban township in Zambia. A prospective study of children during their first year of life.

In a prospective study of 257 children in Lusaka during their first year of life the infant mortality rate was 118 per thousand live births. Deaths were due to prematurity and respiratory problems during the first few months of life, and diarrhoea, measles, and malnutrition during the later months. The low birth weight rate was 11 per cent. Growth was good during the first 6 months, but thereafter there was faltering in weight gain and gain in length faltered after 8 months. By age year 1 only 12 per cent attained the average weight-for-age and 8 per cent the average height-for-age. Breast feeding decreased in frequency very gradually over the first year with 66 per cent of children still being breast-fed more than six times a day at a year. Meals were usually given only three times a day and consisted mainly of maize porridge with vegetables, beans, or meat when it could be afforded. Over 70 per cent of children were fully immunized. Milestones were generally achieved at expected ages or even earlier. Where they were delayed most of the children affected died within a couple of months. Recommendations are made on the surveillance of infants in urban areas and the provision of a precooked fortified appropriate weaning food obtained at Health Centres.

Birth Weight↗
PubMed1989

Mothers in an urban township in Zambia.

Two hundred and forty-nine mothers living in an urban township were followed at their home from delivery for 1 year. Sixty-four families were lost to follow up due to moving house. The neonatal mortality was 50.6 per thousand and the infant mortality 118 per thousand live births. Child loss increased after parity 8 of the mother. The mean (SD) weight of mothers was 56.8 kg (8.8), the mean height 157.8 cm (6.1) and the mean ponderal index 22.53 (3.51). The mid-arm circumference was 26.1 cm (2.8). Body size varied considerably with around 10 per cent of mothers being undernourished and 10 per cent obese. Weight and mid-arm circumference generally decreased after 6 months post-partum. Breast feeding became less frequent after 8 months and by a year four babies had stopped receiving any breast milk. Average birth intervals were around 30 months, but thirty-seven mothers (20 per cent of multiparous mothers) had intervals of less than two years often following the loss of a previous child. Women generally received less education than their husbands with 35 (17 per cent) having had no education and only 23 (11 per cent) with some secondary education. Thirty-five mothers (18 per cent) had no men living at home with them although some fathers provided support. By one year fifteen fathers had abandoned the mother. Incomes of most families were insufficient and half the mothers worked, usually by selling food at the market or outside their homes.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Intervals↗
PubMed1987

Monitoring untreated periodontal disease.

The purpose of this study was to monitor clinical attachment levels, using a constant force probe, in patients with untreated periodontal disease, and to use darkfield microscopy to monitor changes in subgingival plaque. 10 patients with untreated disease were studied over 12 weeks. The parameters measured at baseline and every 4 weeks were probing depth, attachment level and bleeding. The subgingival microflora of the deepest site in each quadrant was examined by darkfield microscopy, using a Hellber counting chamber, at baseline and 12 weeks. The subgingival plaque from any site which lost more than 2 mm clinical attachment was also sampled and the microflora examined. Analysis of the results shows that 91% of probing depths and attachment levels remained the same or within +/- 1 mm. 3.5% of probing depths and 3.7% of attachment levels became deeper by 2 mm. 6.9% of probing depths and 4.5% of attachment levels became shallower by 2 mm. Only 6 sites out of 1029 showed loss of clinical attachment greater than 2 mm. Darkfield microscopy showed no differences in the proportion of microorganisms at the 6 sites which lost more than 2 mm of clinical attachment, compared with the baseline value. A surprising result was the tendency for probing depths and attachment levels to decrease, especially in deeper pockets. This study showed that none of the parameters monitored, i.e., probing depth, attachment level, bleeding or subgingival microflora, indicated which sites would lose attachment over a 12-week period.

Adult↗
PubMed1987

Validity of a hinged constant force probe and a similar, immobilised probe in untreated periodontal disease.

The validity of a hinged constant force probe (0.25 N) was compared with that of a similar but immobilised instrument, using the same interchangeable tip for both (0.64 mm diameter; 2 mm divisions). 60 sites were measured on teeth which were extracted subsequently, in patients with untreated periodontal disease, and the connective tissue attachment level was used as validity criterion. The clinical measurements of both probes correlated well with each other, but they differed significantly from the post-extraction connective tissue attachment level measurements, indicating a point 1.2 mm coronally to this, on average. A companion investigation of intra-operator probing depth reproducibility with the 2 probes, was undertaken in 14 patients, at 2 visits separated by 1 week in each case. All patients had untreated periodontal disease. A difference between probes was found at the first visit, but not at the second; the immobilised probe showed a difference between visits, reducing mean probing depth slightly at the second; when the immobilised probe was used first, there was a difference between probes. Further analysis of the results indicated that there was greatest agreement between probes when the constant force probe had been used before the immobilised probe at the second visit. The results suggested that these probes indicated a point above the connective tissue attachment level, related to pocket morphology, and that there was a moderate learning effect due to operator use of the constant force probe, which modified use of the immobilised probe.

Connective Tissue↗
PubMed1987

Constant force probing with and without a stent in untreated periodontal disease: the clinical reproducibility problem and possible sources of error.

There is presently no satisfactory method of detecting periodontal disease activity at a specified site by means of clinical measurements. This study was designed to examine the possible sources of error with regard to probing measurement reliability. Intra-examiner reproducibility of probing measurements was studied at 766 sites in 10 patients with untreated periodontitis, using a 0.25 N hinged constant force probe (a) with a stent for guidance and landmark, and (b) without stent. The stent made little difference to overall reproducibility of probing depths, though it appeared to reduce variation in different areas. Repeated probing led to an increase in some measurements, perhaps by an effect on tissues. Reproducibility of probing depth was lower in deep pockets, and about 2% of all probing depth scores varied by 3 mm or more at the same site. 4 possible sources of measurement error were noted: visual and tactile observational error, positional error and tissue change. The results are discussed in relation to the clinical detection of periodontal disease activity.

Diagnostic Errors↗
PubMed1987

Inhibition of human bone marrow-derived stem cell colony formation (CFU-E, BFU-E, and CFU-GM) following in vitro exposure to organophosphates.

Cholinergic toxicity of organophosphate insecticides is regarded as the principal health hazard associated with both human and animal exposures. Recent studies indicate that these pesticides may have important effects on both the immune and hematopoietic systems. In the present study, human bone marrow cells were exposed in vitro to paraoxon and malaoxon (the primary metabolites of parathion and malathion). These compounds produced dose-dependent depression of colony formation by erythrocyte (burst-forming units-erythroid [BFU-E] and colony-forming units-erythroid [CFU-E]) and granulocyte-macrophage progenitors (colony-forming units-granulocyte-macrophage [CFU-GM]). CFU-E colony formation was reduced 15%-57%, by both paraoxon and malaoxon, in the range of 10(-8)-10(-5) M. No effects were seen at 10(-9) and 10(-10) M. Colony formation by BFU-E was reduced 15%-75%, at 10(-9)-10(-5) M organophosphate (OP), then returned to normal at 10(-10) M OP. In comparison to CFU-E, BFU-E appeared to be more sensitive to the suppressive action of OPs. Numbers of CFU-GM colonies were reduced 16%-59% in the range of 10(-9)-10(-5) M OP, then returned to normal at 10(-10) M OP. Choline chloride added to marrow cultures (final concentration, 10 mM) enhanced CFU-GM colony formation at all concentrations of paraoxon and malaoxon. Our results provide a rationale for assessing hematologic parameters in occupationally exposed individuals, and indicate the need to determine both the mechanism and the environmental health consequences of the observed hematopoietic effects.

Bone Marrow↗