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Biomedical subjects

G M Walker

Publications and source records attributed to G M Walker.

30 records · Page 2Linked to original sources
PubMed1993

Unemployment and health: a review.

Unemployment has an adverse effect on health. This effect is still demonstrable when social class, poverty, age and pre-existing morbidity are adjusted for. Unemployed men and their families have increased mortality experience, particularly from suicide and lung cancer. Unemployed men also have a reduction in psychological well-being with a greater incidence of parasuicide, depression and anxiety. Unemployed men are more likely to use general practitioner and hospital services and receive more prescribed medicines. Smoking and alcohol consumption are often increased after the onset of unemployment. Women are less affected by enforced unemployment, but families are put at greater risk of physical illness, psychological stress and family breakdown. Maintaining financial security, providing proactive health care and retraining for re-employment can all reduce the impact of unemployment on health.

Family Health↗
PubMed1986

Magnesium and cell cycle control: an update.

Accumulating evidence, from bacteria to human cells, points to a universal role for magnesium in controlling the cell cycle. In microorganisms, the co-ordinate sequence of events which culminate in biomass doubling and cell division may be modulated through expression of differential magnesium effects during the cell cycle. For example, it has been suggested in bacteria that growth and cell division may possess different affinities for magnesium; whilst in yeast, cell cycle-dependent fluxes in intracellular magnesium are postulated to regulate cell proliferation. In mammalian cells, magnesium is important in governing key rate-limiting steps in the cell cycle, particularly at the onset of DNA synthesis and at mitosis. Furthermore, it has been demonstrated that cell transformation may cause selective loss of this regulatory role for magnesium, implying that magnesium is important in oncogenesis and perhaps in the expression of malignancy.

Animals↗
PubMed1984

A proposed method for the analysis of public health policy in less developed countries.

The study of public health policy in the less developed countries (LDCs) is handicapped by both lack of adequate data and gaps in conceptual apparatus. A new conceptual model is proposed that would be used for future policy analyses to assess what changes in health status of populations in LDCs can be expected as direct functions of increased health service resources, and of improved environmental and econosociocultural conditions. While direct policy analysis is ill-advised at this time due to data inadequacy, the model is illustrated using data presently available for twenty-five relatively homogeneous sub-Sahara African countries. Within the limitations of available data, the findings suggest that reductions in mortality in the region might best be achieved by making appropriate health resources available to the populations. Study findings also suggest that physicians contributed more during the study period to the variance in physical health status than did medical assistants.

Africa↗
PubMed1984

Magnesium and the regulation of germ-tube formation in Candida albicans.

Candida albicans requires Mg2+ for germ-tube formation. Mg-deficient media, metal ion chelators and the ionophore A23187 inhibited germ-tube formation. Cell Mg content during exponential yeast-phase growth remained constant but increased throughout germ-tube formation. The onset of germ-tube formation coincided with a sharp peak in Mg concentration within the cells. Yeast-phase cells of strain CA2, which did not form germ-tubes, had a lower Mg content and failed to accumulate Mg when incubated under conditions for germ-tube formation. Mg also increased the uptake and incorporation of N-acetylglucosamine. These findings point to a central regulatory role for Mg in C. albicans morphogenesis.

Acetylglucosamine↗
PubMed1982

Cell cycle specificity of certain antimicrotubular drugs in Schizosaccharomyces pombe.

Of the seven antimicrotubular drugs tested, nocodazole, mebendazole and trifluralin at saturable concentrations failed to inhibit cell division in Schizosaccharomyces pombe, while carbendazim, thiabendazole and chloropropham each at 50 micrograms ml- and amiprophos methyl at 200 micrograms ml-1 completely arrested cell division. This inhibition was associated with striking morphological changes in which carbendazim- and thiabendazole-treated cells became elongated and pseudohyphal, whereas chloropropham- and amiprophos methyl-treated cells appeared small and rounded with occasional V-shaped pairs. Lomofungin staining revealed that nuclear division was also arrested by these drugs. Suspected blockage of defined cell cycle stages was confirmed by pulse-induction experiments which revealed that cells could be synchronized into division using exposure to a drug for one generation. Further experiments with synchronous cultures prepared by size selection showed that different drugs possessed different transition points; for example, carbendazim and thiabendazole were effective in blocking a late stage of the cell cycle just prior to division, whereas amiprophos methyl affected a very early stage. The results suggest that some of the drugs used exert cell cycle specificity in S. pombe either by impairing microtubule assembly mechanisms (as with carbendazim and thiabendazole) or by inhibiting synthesis of tubulin subunits (as with amiprophos methyl). These drugs could prove useful in studies of microtubule biogenesis during the cell cycle in yeast.

Ascomycota↗
PubMed1980

Magnesium ions and the control of the cell cycle in yeast.

A study has been made of the role of magnesium ions in cell division cycle control in the fission yeast, Schizosaccharomyces pombe, and the budding yeast, Kluyveromyces fraglis. Synchronization of cell division in these organismms can be induced by restoring magnesium to magnesium-exhausted cultures. In S. pombe, a correlation exists between the time taken for cells to enter the first synchronous division and the period of magnesium exhaustion. During short-term incubation in magnesium-deficient media, S. pombe cells are observed to continue growth in length, but they fail to make a cell plate and divide; long-term magnesium deficiency results in the production of aberrant cell forms, and a reduction in viability. Analysis of total cell magnesium in cultures of both S. pombe and K. fragilis, synchronized by various induction and selection procedures, revealed that there is a fairly steady fall in magnesium concentration as cells grow, terminating in a rapid influx of magnesium just before cell division. This leads to the hypothesis that falling magnesium concentration may act as a transducer of cell size, eventually triggering spindle formation and a membrane change which permits rapid uptake of magnesium to a concentration which brings about spindle breakdown. The hypothesis was tested directly using the divalent cation ionophore, A23187, in the absence of calcium ions; the results obtained showed that a short pulse of A23187, very late in the cell cycle, accelerated cells into division and shortened the subsequent cycle. The hypothesis is discussed in relation to current models of cell cycle regulation.

Calcimycin↗
PubMed1979

Utilization of health care: the Laredo migrant experience.

In 1973, three groups of randomly selected migrant labor families resident in Laredo, Texas were enrolled in a prepaid health insurance study. A study was implemented to determine the kinds and costs of medical care used by Mexican American migrant labor families in their homebase and travel areas where financial barriers to care were eliminated or reduced. At the end of three years it was found that the study population used ambulatory services about one-half as much as the general U.S. population while hospital use approached regional norms. The differences between homebase and out-of-area use are highlighted, and the reported failure to use any public facilities outside of Laredo is discussed.

Adolescent↗
PubMed1978

Breast biopsy. A comparison of outpatient and inpatient experience.

Nine hundred ninety-seven breast biopsies that were performed at one hospital over the five-year period from 1971 through 1975 were reviewed because of a changing pattern in the use of breast biopsies on outpatients who were under local anesthesia. In 1971, 17% of all breast biopsies were performed as outpatient procedures; by 1975, the figure was 60%. In 1971, 5% of all malignant neoplasms were diagnosed by the use of biopsies as outpatient procedures and 30% in 1975. Hospital charges for biopsy on an inpatient basis of benign breast disease were 7.2 times higher than for biopsy on an outpatient basis. Interviews of 102 patients clearly suggested that most patients were satisfied with the outpatient breast biopsy experience. Outpatient breast biopsy under local anesthesia is a safe procedure that is more economical in terms of medical cost, surgeons' time, and patients' time away from home and/or job. Preliminary biopsy of malignant lesions using local anesthesia permits more efficient use of diagnostic procedures to stage the extent of disease prior to treatment. Patient acceptance of breast biopsy as an outpatient procedure under local anesthesia was similar to their acceptance of biopsy on an inpatient basis under general anesthesia.

Ambulatory Care↗