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Biomedical subjects

M Ross

Publications and source records attributed to M Ross.

At least 271 records · Page 15Linked to original sources
PubMed1985

Are the renal functional changes of human pregnancy caused by prostacyclin?

To investigate the hypothesis of others that the many characteristic physiological alterations of pregnancy are due to prostacyclin, the effects of this vasodilator prostaglandin on renal function and related variables were measured. Intravenous infusion of prostacyclin (7 ng/kg/min) for 90 minutes in seven healthy male volunteers resulting in a significant fall in diastolic blood pressure and increase in heart rate. No significant change occurred in renal plasma flow or glomerular filtration rate in response to the prostacyclin, but there were significant falls in uric acid clearance (16 +/- 1.3----10 +/- 1.5 ml/min/ 1.73m2) and in free water clearance (4.0 +/- 1.1-----0.5 +/- 0.4 ml/min) both of which rose rapidly to pre-infusion levels upon cessation of prostacyclin infusion. Plasma renin and aldosterone levels rose sharply during prostacyclin infusion, falling to pre-infusion levels rapidly afterwards. Although the haemodynamic alterations were similar, the renal functional effects of prostacyclin infusion were quite different from (and often opposite in direction to) those of normal pregnancy. This acute study therefore does not add support to the hypothesis suggested by others that these alterations in pregnancy are due to prostacyclin, and that deficiency of prostacyclin will lead to the changes of pregnancy-associated hypertension.

Adult↗
PubMed1985

Arachidonic acid and isolated human umbilical vein: concentration-limited prostacyclin generation and absence of direct toxic effects on endothelial integrity.

Previous studies show that administration of high doses of arachidonic acid to rabbits causes disruption of vascular integrity. To examine if similar changes would occur in isolated human vascular tissue, we treated human umbilical veins with arachidonic acid (0, 0.01, 0.1, 1.0 mM). Prostacyclin biosynthesis was quantitated in the supernatants and the endothelial integrity was evaluated by scanning electron microscopy. Prostacyclin synthesis was maximum at low concentrations (0.01-0.1 mM) with no additional increase with higher concentrations of arachidonic acid (1mM) confirming previous observations. There was no evidence for endothelial disruption with any concentration of arachidonic acid. This study shows that arachidonic acid has no direct effects on the vascular lining of isolated human umbilical vein, arachidonic acid-induced sudden death in experimental animals is not due to limitation of prostacyclin synthesis.

Arachidonic Acid↗
PubMed1985

Primary modality for speech perception in children with normal and impaired hearing.

The relationships between each of seven predictor variables and the relative degree to which 84 normal and hearing-impaired children used audition or vision in their perception of word stimuli were investigated. The children's relative use of audition or vision was assessed by the auditory-visual presentation of monosyllabic word stimuli in which the visual word stimuli were in conflict with those presented acoustically. Six of the seven predictor variables were significantly correlated with the performance scores obtained within the auditory-visual conflict condition. Only pure-tone average hearing level and auditory word identification performance, however, made unique contributions toward predicting the degree to which audition or vision was used in the perception of the word stimuli. We concluded that the relative use of audition or vision was almost completely related to their auditory capabilities as represented by the children's unaided threshold sensitivity and aided speech reception performance.

Adolescent↗
PubMed1985

Cross-national study of perceived parental rearing behaviour in healthy subjects from Australia, Denmark, Italy, The Netherlands and Sweden: pattern and level comparisons.

Samples of healthy subjects from Australia, Denmark, Italy, The Netherlands and Sweden completed the EMBU, a Swedish questionnaire aimed at assessing the experience of parental rearing practices. For the purpose of comparison three factors - "emotional warmth", "rejection" and "overprotection" - obtained in a previous factor analytic study, have been used. The most pronounced differences occurred between the Dutch and the Swedish sample on the one hand, and the Italian and Australian sample on the other, with the Danish sample in between. Differences in perceived parental rearing should be considered when comparing personality characteristics and/or psychopathological conditions in subjects from different countries.

Adult↗
PubMed1985

Decreased platelet aggregation but increased thromboxane A2 generation in polycythemia vera.

Patients with polycythemia vera have been described to have hemorrhagic as well as thrombotic tendencies. In a patient with polycythemia vera and angina pectoris, we observed markedly decreased platelet aggregation response to epinephrine but increased platelet and whole-blood thromboxane A2 generation compared with normal subjects. Electron microscopy mostly showed partially activated forms of platelets, which may account for decreased aggregation response in vitro and hemorrhagic tendencies. Young and large platelets found in this disease, however, can generate large amounts of vasoconstrictor and platelet proaggregatory prostanoid thromboxane A2 in response to endogenous thrombin, which may be a basis for thrombotic tendencies.

Angina Pectoris↗
PubMed1985

An evaluation of the effectiveness of individual and group cognitive therapy in the treatment of depressed patients in an inner city health centre.

Depressed patients were allocated randomly to individual cognitive therapy, group cognitive therapy or a waiting list ;treatment as usual' control group. Blind clinical and psychometric assessment of patients revealed that those who underwent cognitive therapy did significantly better than those on the waiting list. There was no significant difference between patients treated with group or individual cognitive therapy. Threatment gains were maintained at follow-up at 12 months. Prognostic characteristics for the selection of depressed patients for cognitive therapy on the basis of the chronicity and social stresses are identified. It is concluded that cognitive therapy is an effective treatment which can be applied cost-effectively in general practice.

Adult↗
PubMed1984

Oxytocin secretory response to breast stimulation in pregnant women.

Plasma oxytocin levels were measured serially in 10 pregnant women prior to labor and 16 women during labor in response to 12 minutes of Egnell breast pump stimulation. There was no increase in plasma oxytocin concentrations during either the second or third trimesters in 24 of the 26 subjects studied. Five minutes of manual autostimulation of the breast in 10 additional women at term also had no effect on plasma oxytocin levels.

Breast↗
PubMed1984

A diagnostic "patch test" for onchocerciasis using topical diethylcarbamazine.

There is great need for a simple, inexpensive, and sensitive diagnostic test for onchocerciasis, especially in endemic areas where trained personnel and laboratory facilities are limited. Diethylcarbamazine (DEC) was applied as a "patch test" to the skin of 45 patients with onchocerciasis in the Southern Sudan. 75 tests were done on these 45 patients, and 69 (92%) were positive. A positive reaction was a papular eruption beneath the patch. Histopathological studies of the skin beneath the patch revealed the microscopic features of a severe Mazzotti reaction, including degenerating microfilariae in the upper dermis and within epidermal eosinophilic abscesses.

Administration, Topical↗
PubMed1984

Maduromycosis (Madurella mycetomatis) in a horse.

A case of maduromycosis mycetoma caused by Madurella mycetomatis is reported. The horse presented with multiple subcutaneous swelling over the right scapula. There were no discharging fistulae present. Macroscopically the lesion contained a black granular material embedded in a granulomatous mass. Microscopically large numbers of microcolonies were present containing segmented hyphae. No typical chlamydospores were observed. Cultures yielded a fungus identified as Madurella mycetomatis. Treatment consisted of surgical excision and local treatment with thiabendazole powder.

Animals↗
PubMed1983

Social Security Amendments of 1983: legislative history and summary of provisions.

This article traces the legislative history of the new law from the report, on January 20, 1983, of the recommendations of the National Commission on Social Security Reform (which formed the basis of this legislation) to enactment, on April 20, 1983, of Public Law 98-21. It also analyzes the provisions of Public Law 98-21, which, among other things, delay the annual cost-of-living adjustments in benefits from July to January of each each year, make up to one-half of the benefits received by higher-income beneficiaries subject to income taxes, gradually raise the retirement age early in the next century, call for the earlier implementation of schedule payroll tax increases, and put new Federal employees under the Social Security program. The legislation also establishes a new system of prospective payment for hospital services under Medicare and extends supplementary unemployment compensation benefits that otherwise would have expired in March 1983.

Costs and Cost Analysis↗
PubMed1982

Female sterilization - a follow-up report.

A retrospective study of 1204 patients who made use of a free sterilization service is reported. The mean length of follow-up was 21 months. Of the patients, 95% were satisfied with the results of the procedure and only 0,25% wanted a reversal. The rate of hysterectomies performed subsequent to sterilization was 1,2%. Sterilization did not adversely influence the menstrual pattern or menstrual discomfort.

Adult↗
PubMed1982

Primary care and medical education.

There is considerable argument for the value of educating medical students in the basics of primary care, comprehensive care and concern for psychological needs of patients. However, medical schools do not place much emphasis on primary care. Most clinical experiences take place in tertiary care centers, and most teaching is provided by specialists. Relatively little attention is paid to psychological issues of care and development of interpersonal skills among would-be physicians. The impact of the tertiary care orientation is widespread. Medical students are expected to adopt the role of the physician-specialist or technologist. Those who want to be primary care physicians have to face value conflicts with the establishment, and some develop emotional problems. The effects carry over into practice. Physicians who do not develop adequate personal skills are less likely to be viewed as competent by their patients. They are also more likely to develop mental health problems themselves. This article argues for a modification of the medical school curriculum to reflect the orientation of the primary care model.

Clinical Competence↗