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Biomedical subjects

M Clarke

Publications and source records attributed to M Clarke.

At least 235 records · Page 13Linked to original sources
PubMed1989

Cardiac catheterisation by the Judkins technique as an outpatient procedure.

OBJECTIVE: To assess the safety and cost benefit of left heart catheterisation by a modified Judkins technique performed as a day patient procedure. DESIGN: Review study of case notes of consecutive patients examined by the procedure over three years (January 1984 to December 1986). SETTING: Outpatient referrals in a regional cardiac centre within a district general hospital. PATIENTS: Nine hundred patients aged 18-76 (mean 54) selected at a previous clinic as suitable for the procedure. MAIN RESULTS: Eight hundred and fifty patients (94.4%) were discharged home on the day of the procedure. Forty others (4.4%) could not be discharged owing to complications during or just after the procedure. Of these patients, two died (0.2%), six suffered a myocardial infarction (0.7%), and two had major vascular complications. The remaining 30 patients were admitted because of chest pain without infarction (10 cases), minor vascular incidents (six), haemorrhage at the puncture site (five), arrhythmia (four), pulmonary oedema (three), and contrast reaction (two). Ten patients were admitted for either urgent coronary artery bypass grafting or social reasons. CONCLUSIONS: Cardiac catheterisation is safe as an outpatient procedure in most cases. Beds are spared and roughly 35,000 pounds is saved for every 500 procedures performed.

Adolescent↗
PubMed1989

Ventilatory response to an inhaled constant CO2 load and added dead space in healthy men, awake and asleep.

Experiments were conducted in ten adult men to determine if rapid-eye-movement sleep (REMS) reduced the ventilatory response to two 'steady-state' respiratory loads compared to slow wave sleep (SWS). A constant addition of 150 (or 200) ml/min pure CO2 to the inspirate (7 subjects) and 230 ml of added dead space (5 subjects) were the two respiratory loads. Inspiratory ventilation was measured by pneumotachygraph for at least five continuous minutes in wakefulness, SWS and REMS. The increase in ventilation to both stimuli was equal in SWS and REMS with no suggestion of an impaired response during the latter: increases in ventilation during CO2 loading being 49 and 51%, SWS and REMS, respectively, and during additional dead space they were 53 and 59%, SWS and REMS, respectively. Following the addition of extra dead space, end tidal PCO2 levels did not rise significantly more during REMS compared to SWS (P greater than 0.5). These findings show that when ventilatory responses to CO2 are considered across the whole of REMS (including periods with and without actual eye-movements) then they do not appear to be blunted compared to SWS.

Adult↗
PubMed1989

Mental and physical health of elderly people: five-year follow-up of a total population.

The change in mental and physical functioning over 5 years for 594 survivors of a community survey of the elderly is described. An increase in cognitive impairment, physical disability and incontinence over the period was found with increasing age. Women in the two oldest age groups had a significantly greater increase in physical disability than men. An annual incidence of cognitive impairment of 1.4% was found and the implications of this are discussed.

Aged↗
PubMed1988

Fertility and legal abortion in England and Wales: performance indicators for family planning services.

The relation between fertility rates and legal abortion rates was investigated in a sample of health authorities in England and Wales to see how these varied. Total period fertility rates and total period legal abortion rates were derived from the average number of live births or legal abortions that would be experienced per woman if women experienced the age specific rates of the year in question throughout their childbearing years. The sample of 30 health authorities was selected by taking the districts with the highest and lowest fertility rates in each English region and in Wales in 1986. Total period fertility rates varied from 1.37 in Riverside to 2.42 in Tower Hamlets, while abortion rates varied from 0.25 in East Yorkshire to 0.99 in Riverside. When the two rates were added to provide a potential fertility rate it became clear that some districts with similar potential fertility rates had very different underlying component rates. Such comparisons can be used for service monitoring, indicating the need for better abortion and family planning services in districts with high fertility rates and for better family planning services in those with high abortion rates.

Abortion, Legal↗
PubMed1988

Asian mothers' risk factors for perinatal death--the same or different? A 10 year review of Leicestershire perinatal deaths.

A case-control study of all perinatal deaths in Leicestershire was established in 1976. By 1985 some 1342 singleton perinatal deaths had occurred. Perinatal mortality among patients of Asian origin was consistently higher than that among European women. Many of the sociomedical risk factors for perinatal death known at booking were common to both population groups. In this population of Asian women, however, low social class was not associated with perinatal risk and illegitimacy hardly ever occurred. In contrast, previous infertility among the Asian women was associated with risk of perinatal death, while no such association was found with European women. In 19% of perinatal deaths care was either inadequately provided or taken up. The case-control design in these circumstances provides a practicable way to evaluate causal factors and at the same time to provide information of value to educators and health service planners.

Adolescent↗
PubMed1988

Analysis of the prestarvation response in growing cells of Dictyostelium discoideum.

We have previously shown that growing cells of Dictyostelium discoideum (strains NC4 and AX3) produce a soluble substance that accumulates in the medium in proportion to cell density; this substance regulates the production of certain proteins previously thought to be induced by starvation [Clarke et al., 1987]. We suggest the name PSF (prestarvation factor) for this substance. During growth, Dictyostelium cells monitor the relative concentrations of PSF and food bacteria. When PSF reaches a sufficiently high level relative to the concentration of bacteria, synthesis of PSF-regulated proteins is induced. We propose the name prestarvation response for this induction, which takes place in exponentially growing cells several generations before the food bacteria are depleted. We have explored the mechanism by which the food bacteria inhibit the response of Dictyostelium cells to PSF. We find that the bacteria do not inactivate PSF or inhibit its production; instead, they affect the ability of NC4 cells to detect PSF, possibly by binding to the same cell surface receptor. In the absence of bacteria, as during axenic growth of AX3 cells, the prestarvation response occurs at much lower cell densities, probably accounting for the presence of certain developmentally regulated mRNAs and proteins in axenic cultures.

Dictyostelium↗
PubMed1988

Two DNA endonuclease activities from normal human and xeroderma pigmentosum chromatin active on psoralen plus ultraviolet light treated DNA.

DNA endonuclease activities from the chromatin of normal human and xeroderma pigmentosum, complementation group A (XPA), lymphoblastoid cells were examined on DNA treated with 8-methoxypsoralen (8-MOP) or 4,5',8-trimethylpsoralen (TMP) plus long wavelength ultraviolet (UVA) light, which produce monoadducts and DNA interstrand cross-links, and angelicin plus UVA light, which produces mainly monoadducts. 9 chromatin-associated DNA endonuclease activities were isolated from normal and XPA cells and assayed for activity on PM2 bacteriophage DNA that had been treated with 8-MOP or TMP in the dark and then exposed to UVA light. Unbound psoralen was removed by dialysis and a second dose of UVA light was given. Cross-linking of DNA molecules was confirmed by alkaline gel electrophoresis. In both normal and XPA cells, two DNA endonuclease activities were found which were active on 8-MOP and TMP plus UVA light treated DNA. One of these endonuclease activities, pI 4.6, is also active on intercalated DNA and a second one, pI 7.6, is also active on UVC (254 nm) light irradiated DNA. The major activity against angelicin plus UVA light treated DNA in both normal and XPA cells was found in the fraction, pI 7.6. The levels of activity of both of these fractions on all 3 psoralen-damaged DNAs were similar between normal and XPA cells. These results indicate that in both normal and XPA cells there are at least two different DNA endonucleases which act on both 8-MOP and TMP plus UVA light treated DNA.

Cell Line↗
PubMed1988

motA1552, a mutation of Dictyostelium discoideum having pleiotropic effects on motility and discoidin I regulation.

The Dictyostelium discoideum mutant MC2 exhibits temperature-sensitive growth, temperature-sensitive motility, and temperature induction of discoidin I synthesis. These three phenotypes of MC2 were not separated in the genetic experiments reported here. They were therefore assigned to the mutation motA1552, which was mapped to linkage group II by segregation analysis and by analysis of mitotic recombinant diploids. In one motA1552 strain, loss of motility preceded accumulation of discoidin I by 3 hr, indicating that discoidin I is not involved in generation of the motility defect. Expression of motA1552 phenotypes varied both among strains carrying the mutation, and among different clones of a particular strain. MC2 and its derivatives displayed elevated levels of recombination between whiA and acrA on linkage group II, and yielded highly unstable mutations at the acrA locus. Accumulation of large amounts of discoidin I during axenic growth of strain AX3 was found to depend on the presence of a second linkage group II mutation, daxA1551. This mutation was already present in the strain mutagenized to isolate motA1552, complicating explication of motA1552 action.

Cell Movement↗
PubMed1988

Mortality risks in the elderly: five-year follow-up of a total population.

The health and social status was assessed by interview for all people aged 75 years and over, living in and around Melton Mowbray. This initial survey took place in 1981 and five years later, data are now available on the mortality status of the original survey population. Significantly lower survival rates were found for various subgroups including those respondents who perceived their health poor, those with high disability scores and severe cognitive impairment and those taking hypoglycaemic agents and diuretics.

Aged↗
PubMed1988

The nursing prevention of pressure sores in hospital and community patients.

The main purpose of the study was to evaluate the amount of time which was spent in giving preventive pressure area care in both a sample of hospital patients (n = 88) and a sample of community patients (n = 30). Bedfast or chairfast patients were studied from admission to the selected hospital wards or community nursing areas for a period of a maximum of 6 weeks or until they were discharged from care, developed pressure sores, died or became mobile. Data were collected by means of a diary sheet which was designed for use by nurses in the hospital and by nurses and relatives in the community. They were asked to record pressure area care as it was given on the diary sheets. The researcher also collected data about the patients' appetite, Norton score, age, sex and diagnosis. The outcome measure used was whether or not the patient developed a pressure sore, which was defined for this study as a break in the skin due to pressure. Some descriptive analysis of the data has been carried out. Results available so far show that a higher percentage of the hospital patients developed pressure sores (29%) than among the community patients studied (20%). The study appears to show that nursing care devoted to the prevention of pressure sores in terms of time and frequency is significantly related to outcome and thus to effectiveness.

Aged↗
PubMed1988

Epilepsy precipitated by bathing.

A case of epilepsy precipitated by bathing is described and previously reported cases are reviewed. The prognosis for this rare form of reflex epilepsy seems to be good, in that the seizures resolve with age and neurodevelopment remains normal.

Baths↗
PubMed1988

Determinants of delayed gastric emptying in anorexia nervosa and bulimia nervosa.

Gastric emptying was measured using a gamma camera in 22 patients with anorexia nervosa, in 10 patients of normal or high weight with bulimia nervosa and in 10 controls. Patients with anorexia nervosa were tested (1) while underweight and selecting their own diet (10 patients); (2) underweight, but receiving an adequate diet on an inpatient unit (refeeding diet) (12 patients); and (3) under refeeding diet conditions after weight gain (eight patients). Three meals, each labelled with technetium 99m-sulphur colloid, 3.7 MBq were used: (1) a mixed solid meal containing labelled poached egg; (2) 200 ml d-glucose solution, 0.5 kcal/ml, and (3) 200 ml physiological saline. Only gastric emptying rates of the solid meal and glucose solution were significantly delayed. Gastric emptying of saline was normal. The gastric disturbance was confined to patients with anorexia nervosa selecting their own diet. Patients receiving adequate nutrition on the ward had normal gastric emptying and weight gain in this group had no significant effect on emptying. Slow emptying was observed in patients who maintained a low weight solely by food restriction as well as in patients whose anorexia nervosa was complicated by episodes of bulimia. Thus, slow gastric emptying occurred when the quantity of food reaching the duodenum was sufficiently reduced to result in severe weight loss. Moreover, abnormal gastric emptying was seen only after the two meals that contained calories and were hypertonic to plasma, either of which properties could mediate the disturbance. Gastric emptying in bulimia nervosa was normal. Slow gastric emptying could exacerbate undereating in starving patients with anorexia nervosa by enhancing satiety.

Adult↗
PubMed1987

Lethal malformations and perinatal mortality: a 10 year review with comparison of ethnic differences.

During 1976 to 1985 perinatal mortality in Leicestershire decreased from 21 to 9.5 per 1000 births. Throughout this period the incidence of lethal malformations, excluding neural tube defects, remained relatively constant at around 1.8 per 1000 births. Analysis of the malformations present in 201 lethally malformed babies showed that 147 (73%) had a disorder carrying a recurrence risk of 1% or greater. Only 7% of these malformations might have been predicted from the family history or advanced maternal age. The incidence of lethal malformations was significantly increased in the Asian population, largely because of an excess of autosomal recessive disorders. The contribution of lethal malformations to perinatal mortality has almost doubled over the past 10 years and is likely to increase despite prenatal diagnosis and improvements in obstetric and paediatric services.

Asia↗