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Biomedical subjects

G Leach

Publications and source records attributed to G Leach.

At least 19 recordsLinked to original sources
PubMed2003

Vibrating membrane filtration for recovery and concentration of insect killing nematodes.

New experimental data are reported that demonstrate the use of a novel vibrating membrane filter (VMF) for the combined recovery and concentration of two species of nematodes, S. feltiae and P. hermaphrodita, from mature liquid fermentation cultures. The disk membrane module had a working surface area of 0.2 m(2) and was operated at a constant flow rate of 0.2 m(3) h(-1). The recovery of the viable nematodes from the spent media and nonviable nematodes was assisted by an independently imposed oscillatory motion of the disk assembly, which produced an intense shear field at the membrane surface with calculated mean values on the order of 10(4) s(-1). Adult (nonviable) nematodes in the fermentation culture were preferentially dissolved in a detergent (sodium dodecylsulfate) and successfully separated from the juveniles using the VMF equipment. Permeate fluxes on the order of 15 to 30 L/m(2/)h were achieved for an operating transmembrane pressure of 800 mbar. Industrial-scale liquid fermentation for the manufacture of nematodes as biopesticides produces the viable nematode life stages in low-concentration suspension containing large quantities of spent media and other waste material. The VMF equipment provided a flexible operation for separation, cleaning, and concentration of viable nematodes from the fermentation broths.

Animals↗
PubMed1999

Serial murder of six victims by an African-American male.

A case of a 22-year-old African-American male who sexually assaulted and murdered six African-American females who were strangers to him is reported. Formal study of the subject eight years after the homicides revealed a mildly mentally retarded individual who had, at various times, diagnosable anxiety and depressive disorders. His diagnosed paraphilia was sexual sadism. He also met criteria for both Antisocial and Schizoid Personality Disorder, which are discussed in the context of the comorbidity of psychopathy and schizotypy among some serial murderers. Traumagenic events from his childhood and adolescence included an absent father, sexual and physical abuse, the witnessing of adult sex, and the viewing of violent pornography.

Adult↗
PubMed1999

Health related quality of life in a population sample with arthritis.

OBJECTIVE: To determine the prevalence and health related quality of life of a community sample of people with arthritis and compare it with persons with other chronic diseases and the healthy population in South Australia. METHODS: A representative population survey by trained interviewers in autumn 1995 using a multi-stage, systematic, clustered area sample of 4200 urban and country households. There were 3001 (73.6%) respondents aged 15 or over. Subjects were asked, "Have you ever been told by a doctor that you have arthritis?" and "What type?", in addition to the Medical Outcome Survey Short Form-36 (SF-36) health status survey. RESULTS: Medically confirmed arthritis was self-reported in 666 (22.1%) as osteoarthritis (OA) (8.6%), rheumatoid arthritis (RA) (4.0%), and other, or unspecified arthritis (9.6%). People with arthritis were more likely to be female, aged, and of lower socioeonomic status. SF-36 scores were compared to nonarthritic subjects and adjusted for differences in age, sex, and occupational status. Scores were significantly lower for respondents with arthritis, compared with the rest of the population across all subscales of the SF-36 (p<0.05). This was most marked in the subscales measuring physical function and pain. CONCLUSION: Self-reported arthritis is common in the South Australian population, particularly in those aged over 65 years. Arthritis has a major impact on the health related quality of life in the community setting.

Adolescent↗
PubMed1998

Public perceptions and self-reported prevalence of osteoporosis in South Australia.

The self-reported prevalence of, and attitudes to and perceptions of, osteoporosis in the South Australian community were assessed using data collected as part of the 1995 South Australian Health Omnibus Survey (household interviews)--a clustered, self-weighting, multistage sample of households in metropolitan and country centers. The self-reported prevalence was 4.8 (95% CI: 3.7-5.8) and 1.4% (95% CI: 0.8-2.0) for women (n = 1531) and men (n = 1485) respectively. For individuals with osteoporosis, calcium was the favored treatment (52%), while 33% of women were on hormone replacement therapy. An appropriate definition of osteoporosis was given by 62% of women and 37% of men. The main risk factors were reported as lack of calcium and age. There was a significant association between knowledge of the definition of osteoporosis and identification of correct risk factors. A high perceived risk of osteoporosis was reported in 23% of women and 7% of men. Osteoporosis risk was assessed as higher in those who did not adopt recognized prevention measures. Perception of risk was not related to the individual's own risk factors. Self-reported prevalence of osteoporosis significantly underestimates the likely true prevalence and general awareness and knowledge is much lower for men than women. The importance of individual risk factors for osteoporosis are not understood by the general community.

Adolescent↗
PubMed1997

Acute oral toxicity study of pyridostigmine bromide, permethrin, and DEET in the laboratory rat.

This study investigated the lethal interaction of pyridostigmine bromide (PB), permethrin, and DEET when given to adult male rats by gavage and was separated into two phases. Phase I determined the acute oral lethal dose-response relationship of each compound with the vehicle, propylene glycol. Phase II was divided into two portions: a dose-response study using probit units obtained from phase I [lethal dose (LD) 16, 30, 50, 70, and 84], and an interaction study that contained low levels (calculated LD16, additive LD32) of the two compounds while the concentration of the third compound was varied. Rats were fasted overnight, dosed, and observed for 14 d. A significant increase in lethality occurred when PB, permethrin, and DEET were given concurrently when compared to expected additive values. Furthermore, solutions containing PB and permethrin or PB and DEET also caused a significant increase in lethality when compared to expected additive values. This information suggests that lethality in this study was more than an additive effect.

Animals↗
PubMed1993

Effect of stress management on blood pressure in mild primary hypertension.

OBJECTIVE: To establish whether stress management had a larger effect than a control treatment on resting blood pressure, ambulatory blood pressure, and left ventricular mass. DESIGN: A 12 week baseline period of habituation to measurement of blood pressure was followed by randomisation to either stress management or mild exercise for six months and follow up six months later. SETTING: General practice, district general hospital, and medical school. PATIENTS: Of the 184 patients aged under 60 with mild primary hypertension who entered the baseline habituation period, 88 were excluded because they failed to meet the entry criteria or they withdrew from the study. The remaining 46 men and 50 women underwent treatment. INTERVENTIONS: 10 clinical sessions and daily practice at home of either stress management based on relaxation or non-aerobic stretching exercises. Mildly stressful 15 minute interviews before and after treatment. MAIN OUTCOME MEASURES: Diastolic and systolic blood pressure in the clinic and during 12 hours of ambulatory recording, and left ventricular mass measured by echocardiography. RESULTS: The patients' blood pressure fell during habituation (systolic pressure from 152 mmHg to 140 mmHg, diastolic pressure from 98 to 93 mm Hg), but neither resting nor ambulatory blood pressure was changed by the treatments. Left ventricular mass was also unchanged. Blood pressure rose during the stressful interview, but this rise was reduced by stress management (systolic pressure rose by 7.4 mmHg before treatment and by 3.7 mmHg after treatment). CONCLUSION: Stress management of a type advocated for treating mild primary hypertension is ineffective in lowering blood pressure in patients who are well habituated to measuring blood pressure.

Adult↗
PubMed1991

[Bladder neck suspension using the modified Pereyra-Raz procedure in the treatment of stress urinary incontinence in women].

The authors describe the technique of bladder neck suspension with the modified Pereyra-Raz procedure in the surgical treatment of stress urinary incontinence in women. This critical analysis of the technique permits to review its robe the context of the surgical treatment of urinary incontinence and to emphasize the important points to achieve the best possible result.

Adult↗
PubMed1989

Prospective evaluation of an assessment strategy for geriatric urinary incontinence.

The objectives of this study were to design and prospectively evaluate a strategy to assess geriatric urinary incontinence in primary care settings. A management plan for urinary incontinence was determined for 264 elderly incontinent patients (205 females and 59 males) based on a clinical evaluation, simple tests of lower urinary tract function, and several criteria for referral for further evaluation derived from the literature on incontinence. Of the 264 patients, 168 (64%) also consented to undergo a urologic and formal urodynamic evaluation. Half of these 168 patients met at least one criterion for referral for further evaluation. At least one-quarter of the patients who met one or more of the criteria were found not to require surgical intervention, and probably did not benefit from the urologic and urodynamic evaluation. Among 84 patients who did not meet any of the criteria for referral, the urologic and urodynamic evaluation changed the initial treatment plan in only 10 (12%). The risks associated with the treatment plan based on the clinical assessment in these patients were, however, relatively small. While further refinement and testing in larger numbers of incontinent patients are needed, the data presented document that a substantial proportion of elderly patients with a treatable and often ignored problem can be appropriately managed based on a relatively simple and inexpensive assessment, which can easily be carried out in primary care settings.

Aged↗
PubMed1988

Simple versus multichannel cystometry in the evaluation of bladder function in an incontinent geriatric population.

Bladder capacity and stability were determined among 171 incontinent geriatric patients (mean age 80 years) with 2 techniques: a simple procedure for cystometry involving incremental bladder filling by gravity and a continuous water filling multichannel cystometrogram. Bladder capacities measured by both methods in 164 patients were correlated significantly by simple linear regression (r equals 0.75, p equals 0.0001) and they were not significantly different by paired t tests (t equals 1.20, p equals 0.23). Of the patients 110 (64 per cent) had detrusor motor instability or hyperreflexia on the multichannel cystometrogram, and simple cystometry had a sensitivity of 75 per cent, specificity of 79 per cent and positive predictive value of 85 per cent for this finding. The simple procedure was practical, well tolerated and helped to provide information for management decisions that would have been difficult to obtain from many of these geriatric patients without a formal and more complex urodynamic evaluation. When performed with other simple tests of lower urinary tract function and interpreted in conjunction with a few straightforward clinical criteria, simple cystometry can be helpful to assess bladder function among incontinent geriatric patients in settings in which formal urodynamics are either unavailable or impractical.

Aged↗
PubMed1987

A 13-week vapor inhalation study of 3,3-dimethyl-2-butanol in Sprague-Dawley rats.

Four groups of male and female Sprague-Dawley rats were exposed for 13 weeks to 3,3-dimethyl-2-butanol (PA) at concentrations of 0.00, 0.20, 1.00 or 5.00 mg/l (1 mg/l = 240 ppm). Exposures were for 6 hr per day, 5 days per week with sacrifices at 7 and 13 weeks of exposure, and at 4 weeks after exposure. The test animals were evaluated for abnormalities in physiology, behaviour, clinical laboratory parameters, and gross and microscopic morphology. No abnormalities were detected in electrocardiograms, respiratory indices, spontaneous activity, passive avoidance activity and open-field behaviour. Clinical signs related to PA exposure included alopecia, ataxia and lacrimation. There were no biologically significant between-group differences in body-weights during the study. The clinical laboratory data demonstrated a 30% increase in serum cholesterol and bilirubin at 7 weeks in high-dose males and an increase in urea nitrogen in intermediate and high-dose males at 13 weeks. There were no abnormalities in hematologic or coagulation parameters. At necropsy there were no significant gross abnormalities; however, examination of organ weights revealed enlarged kidneys in high-dose male rats at 13 weeks, enlarged ovaries in high-dose female rats at 13 weeks, and microscopic study of tissue sections revealed minimal to mild renal tubular injury in high and possibly intermediate dose males at several sacrifices. These findings suggest that the primary target organ of PA, when given by inhalation, is the kidney in male rats and possibly the ovary in female rats. The renal changes in the high-dose males were not fully reversible during the recovery period.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants, Occupational↗