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Biomedical subjects

J M Watt

Publications and source records attributed to J M Watt.

At least 37 records · Page 2Linked to original sources
PubMed1990

Lead intake and blood lead in two-year-old U.K. urban children.

A comprehensive study of a group of 2-year-old urban children (n = 97), designed to provide quantitative information simultaneously for lead intakes via all identified pathways, has been carried out in Birmingham (U.K.). Results showed that for children whose blood levels and exposure to environmental lead were within the normal range for the U.K., blood lead concentration was significantly related to a combination of house dust lead loading and an overall rate of touching objects, to water lead concentration and to the parents' smoking habits. On the basis of assumptions used by the Royal Commission on Environmental Pollution (RCEP), the estimated average total uptake of lead was 36 micrograms day-1; of this, 97% was from ingestion from dust, food and water and only 3% from inhalation.

Air Pollutants↗
PubMed1990

Lead exposure in young children from dust and soil in the United Kingdom.

A survey of metals in United Kingdom dusts and soils has confirmed widespread lead contamination with a geometric mean value for lead in surface (0-5 cm) garden soils of 266 micrograms/g and in housedusts of 561 micrograms/g (excluding old mining areas). A subsequent detailed survey of 97 householders in Birmingham with 2-year-old children showed dust lead loading in the home environment to be an important predictor of blood lead concentrations in young children, when both variables fell within the normal range for the U.K. The total estimated lead uptake by the young child was 36 micrograms/day of which 1 microgram was by inhalation and 35 micrograms by ingestion.

Child, Preschool↗
PubMed1990

B-mode ultrasound scanning in the detection of proximal venous thrombosis after total hip replacement.

A prospective study of the accuracy of real-time B-mode ultrasonography in detecting deep venous thrombosis in the femoral and popliteal veins of the lower extremity was conducted on a consecutive series of patients who had had a total hip replacement. Ascending venography was used as a diagnostic standard. One hundred and forty-three patients had ultrasound studies of both lower extremities and a venographic study of the operatively treated lower extremity at an average of 7.6 days postoperatively. The two tests were done within twenty-four hours of each other. Both ultrasonography and venography were done on 152 extremities. Two paired studies were excluded from the analysis of results because the ultrasound scans could not be interpreted. In 131 extremities, both diagnostic tests were negative for proximal thrombosis. Eight extremities had isolated thrombosis of a vein in the calf that was detected only by venography. In nineteen extremities, old or fresh thrombosis was diagnosed by venography. In four extremities, an old thrombosis of the superficial femoral vein was detected by both studies. In four of the extremities that had a new thrombus in the common femoral vein and in nine that had a new thrombus in the superficial femoral vein, abnormal findings on ultrasound scans correlated with those on venograms. There were two false-negative ultrasound scans and one false-negative venogram. The sensitivity, specificity, and accuracy of ultrasonography were 89, 100, and 99 per cent for the diagnosis of thrombosis of the proximal veins of the lower limb and 63, 100, and 93 per cent for the diagnosis of thrombosis when the entire venous system of the limb was included.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Early prognosis for ambulation of neonatal intensive care survivors with cerebral palsy.

The ambulatory status of 74 neonatal intensive care unit survivors with cerebral palsy, excluding those with central nervous system malformations and syndromes, was assessed at eight years of age. Detailed examinations were completed at two and eight years of age; of the 47 who were sitting by two years, 46 became ambulatory, and a total of 47 of the 74 children became ambulatory. The clinical type of cerebral palsy at two years of age related significantly to eight-year ambulation. However, between two and eight years the diagnosis was changed for 18 children. At two years of age the tonic labyrinthine, asymmetrical and symmetrical tonic neck and Moro reflexes related significantly to ambulation; in five of 27 children not walking, these reflexes were absent by two years of age. Foot placement and/or parachute reactions at two years were found in more than one-third of children not walking. Multivariate analysis determined that age at sitting explained 91 per cent of the variance in ambulation. No other variables, combined with sitting, increased this prediction.

Ataxia↗
PubMed1988

Effect of lysine-8-vasopressin on retention and retrieval of a discrimination reward task in the rat.

The effect of vasopressin on memory of a brightness discrimination reward task was investigated in 20 male Sprague-Dawley rats. Two measures of retention were used: resistance to extinction and savings scores on a reacquisition task given 45 days after the completion of extinction training. The effect of the peptide on both memory consolidation and retrieval was assessed. There were two major findings: (a) The peptide enhanced memory consolidation of the task whether measured after a short time interval (6 days) or after a long time interval (45 days after completion of extinction training) using a measure of trials to relearn the task, and (b) the peptide had no effect on memory retrieval. These results were compared to those of other studies designed to access memory consolidation and retrieval on appetitive tasks. The mechanisms of the peptide's effect on memory was briefly discussed with respect to three theories on the subject. This study extends the vasopressin research on memory consolidation by suggesting that it pertains to appetitive as well as to aversive tasks.

Animals↗
PubMed1987

Lead levels in Birmingham dusts and soils.

Lead concentrations were measured in housedust, pavement dust, road dust and garden soil in and around 97 inner-city houses in Birmingham, England. The highest mean dust lead concentration within the home, 615 micrograms g-1, was noted in samples from under the doormat. Generally, the housedust lead levels were lower than the national mean (507 micrograms g-1), although soil lead concentrations were slightly higher. The age of the property was found to influence the lead levels in both housedust and garden soil, with older houses (greater than 35 years) having significantly higher concentrations than newer properties (less than 35 years). Houses being decorated at the time of sampling were found to have significantly higher lead concentrations than those that were not. Elevated lead levels were also noted in housedust and garden soil from houses located within a 500 m radius of commercial garages. Increased lead concentrations were found in soil samples from gardens in close proximity to waste land (demolition sites and tips), metal-using industries and from those within 10 m of a road. Road dust samples from industrial areas had significantly higher lead concentrations than those from residential areas.

Dust↗
PubMed1986

The comparative economic performance of investor-owned chain and not-for-profit hospitals.

We examined the differences in the economic performance of 80 matched pairs of investor-owned chain and not-for-profit hospitals in eight states during 1978 and 1980, and considered how their operating strategies might affect their relative success in a more price-conscious market. We found that total charges (adjusted for case mix) and net revenues per case were both significantly higher in the investor-owned chain hospitals, mainly because of higher charges for ancillary services; there were no significant differences between the two groups of hospitals in regard to patient-care costs per case (adjusted for case mix), but the investor-owned hospitals had significantly higher administrative overhead costs; investor-owned hospitals were more profitable; investor-owned hospitals had fewer employees per occupied bed but paid more per employee; investor-owned hospitals had funded more of their capital through debt and had significantly higher capital costs in proportion to their operating costs; and the two groups did not differ in patient mix, as measured by their Medicare case-mix indexes or the proportions of their patients covered by Medicare or Medicaid. We conclude that investor-owned chain hospitals generated higher profits through more aggressive pricing practices rather than operating efficiencies - a result not unexpected in view of past cost-based reimbursement policies. Recent changes in these policies are creating new pressures for cost control and moderation in charges, to which both types of hospitals must adapt. Neither type has a clear-cut advantage in the ability to make the necessary changes.

Capital Financing↗
PubMed1986

Analysis of impedance cardiography longitudinally applied in pregnancy.

Data gathered during a longitudinal study of cardiac output throughout pregnancy, measured by application of impedance cardiography, have been reassessed in respect to individual items of measurement. Examination of the pattern of change in these values did not reveal any flaw in the proposition that impedance cardiography, with the invocation of the Kubicek equation, can confidently be applied in such a study.

Cardiac Output↗
PubMed1985

The effects of ownership and system affiliation on the economic performance of hospitals.

We investigated differences among five types of hospitals, defined by ownership (investor-owned or not-for-profit), system affiliation (system-affiliated or freestanding), and government sponsorship on 24 measures of economic performance. Using multivariate analysis of 1980 Medicare cost report and other data from a national sample of 561 hospitals, we found that investor-owned chain hospitals charged significantly more, and were more profitable, than all other types of hospitals except freestanding for-profits; there were no differences in productive efficiency that could be attributed to ownership or affiliation; the investor-owned hospitals had higher debt-to-asset ratios, less-capital-intensive plants, and greater capital costs as a percentage of operating costs than the not-for-profits; and there were no consistent case-mix differences among the hospitals.

Capital Expenditures↗
PubMed1981

A longitudinal study of cardiovascular dynamic changes throughout pregnancy.

Systemic blood pressure (measured with a zero-randomized sphygmomanometer), stroke volume and heart-rate (measured with a Minnesota Impedance Cardiograph), hematocrit, and their derivatives -- cardiac output and peripheral vascular resistance--have been assessed in three groups of subjects. First, a control group of 19 nonpregnant women were matched for age and weight with the subjects in the second group, which consisted of 19 patients who were seen at regular intervals on 12 to 15 occasions from 8 to 11 wk of pregnancy until 6 wk postpartum. The third group consisted of 8 patients seen from before conception, throughout pregnancy and to several months postpartum. Readings were made with the subject in each of six positions: supine, reclining, left and right lateral, left and right tilt. This paper concerns the readings obtained in the left lateral position. The data showed that pulse rate rose throughout pregnancy. Stroke volume and cardiac output rose shortly after conception, the increase over the prepregnancy level being statistically significant by 12 wk. Thereafter both values fell throughout the rest of pregnancy and were below prepregnancy levels by about term, taking some weeks to regain the prepregnancy value. There were irregular fluctuations in the level of systolic blood pressure; diastolic blood pressure fell during the first 16 wk and then rose to reach almost the prepregnancy value by term. Peripheral resistance fell during the first trimester, then increased markedly throughout the remainder of pregnancy.

Blood Pressure↗
PubMed1981

The influence of posture upon cardiovascular dynamics throughout pregnancy.

Systemic blood pressure (measured with a zero-randomized sphyngmomanometer), stroke volume and heart-rate (measured with a Minnesota Impedance Cardiograph), hematocrit and their derivatives--cardiac output, pulse pressure, mean arterial blood pressure and peripheral vascular resistance, were assessed in 19 nonpregnant women of child-bearing age and in 27 patients who were examined at regular intervals on 12 to 15 occasions from 8 to 11 wk of pregnancy until 6-wk postpartum. Readings were made with the subjects in each of six positions: supine, reclining, left and right lateral, left and right tilt. The purpose of this paper is to compare the results of these different postures. Systolic and diastolic blood pressure readings were lowest in the left lateral and second lowest in the left tilt. We suggest that this reflects a hydrostatic pressure difference. Stroke volume and cardiac output were lowest in the right lateral and second lowest in the right tilt. Thus, the derived values of peripheral resistance were lowest when subjects were turned towards the left and highest when turned towards the right. The rank orders of values were maintained with impressive consistency between subjects (pregnant and nonpregnant) and throughout pregnancy, reaching levels of statistical significance in almost all instances. No evidence was found that aortocaval compression led to a change in the measured attributes of central cardiovascular dynamics. For the 'normal unembarrassed parturient' it is suggested that aortocaval compression is rapidly succeeded by a restablization of these attributes to their previous levels, reflecting the prompt establishment of a suitably diminished circulating blood volume within a reduced vascular capacity. It is nevertheless likely that aortocaval compression will interfere markedly with uteroplacental vascular dynamics and hence pose a hazard to the fetus.

Blood Pressure↗
PubMed1977

Child health revisited.

Much discussion has taken place over the recently published mortality statistics for infants and young children. These statistics are critically examined and conclusions reached. Suggestions with regard to the improving of Child Health Services are made.

Accidents↗
PubMed1972

Ill-thrift.

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Affective Symptoms↗