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Biomedical subjects

M Walker

Publications and source records attributed to M Walker.

At least 433 records · Page 24Linked to original sources
PubMed1989

GATAAG; a cis-control region binding an erythroid-specific nuclear factor with a role in globin and non-globin gene expression.

An erythroid-specific nuclear protein factor binds to a sequence motif (GATAAG) which is present in the promoter region of the mouse alpha and beta major globin genes, and in the erythroid-specific promoter of the human porphobilinogen deaminase (PBG-D) gene. The protein activity is conserved across species, being found in mouse erythroleukaemia (MEL) cells, chicken erythrocytes, the human erythroid K562 and KMOE cell lines, but not in a variety of non-erythroid mouse tissues or in HeLa cells. Functional analysis of this element in the alpha globin gene promoter by stable transfection experiments show that the GATAAG motif resides in a 68 bp sequence which has a stimulatory effect on transcription in mouse erythroleukaemia but not fibroblast cells. The GATAAG motif is conserved in the promoters and 3' enhancers of a variety of globin and non-globin genes implying that it is a cis-element involved in the tissue-specific up-regulation of several genes that are co-expressed during erythroid cell differentiation.

Animals↗
PubMed1989

RFrAP: a computer program for analysis of complex HLA RFLPs. Assignment of restriction fragments to haplotypes by segregation analysis.

The availability of HLA class II cDNA probes has led to the development of a powerful method for the discrimination of genetic variation in this region of the major histocompatibility complex. There are problems with this approach which reduce its usefulness, including the hybridization of a probe with multiple restriction fragments (RFs) from the same locus or of two different cDNA probes with the same RF (cross-hybridizing). These problems may now be largely overcome by the relatively simple computer program presented here, which allows the entry, storage, and editing of phenotype data. It includes utilities for the automatic assignment of bands to haplotypes and also statistical functions to determine several types of correlations. The outputs are presented in a format familiar to HLA serologists and immunogeneticists. In addition, the data is stored in a manner that allows the user to easily prepare "ad hoc" figures and tables that illustrate the more complex relationships among bands and between them and other variables.

Computers↗
PubMed1989

Short stature, lung function and risk of a heart attack.

In a large prospective study of cardiovascular disease in 7735 middle-aged men--the British Regional Heart Study--the 443 subjects who experienced a major ischaemic heart disease event within 7.5 years of follow-up were on average 1.6 cm shorter than the other men (p less than 0.001). The risk of heart attack was approximately twice as great in the shortest quintile of men compared with the tallest quintile. When a number of recognized risk factors for ischaemic heart disease were taken into account--age, social class, serum total cholesterol, HDL-cholesterol, systolic blood pressure, cigarette smoking--there was a marked reduction in the risk of heart attack associated with height. When a measure of lung function (FEV1 not standardized for height) was adjusted for in addition to these risk factors, the height-related risk of heart attack disappeared. Indeed, FEV1 alone was sufficient to account for most of the association between height and the risk of heart attack.

Adult↗
PubMed1989

Analysing qualitative data: ethnography and the evaluation of medical education.

Quantitative methods of evaluating the outcomes of medical education may not always deliver the information which course organizers and teachers most need in order to improve their courses. Qualitative methods of research could provide such information. However, the use of qualitative methods has been limited by the difficulties associated with the analysis of subjective data and by the validity of its results. Qualitative data from an evaluation of the 2-year part-time MSc Course in General Practice at Guy's and St Thomas's Hospitals are presented and a rigorous method of analysis demonstrated. It is argued that for qualitative research validity is progressively achieved through the process of analysis, unlike experimental research where validity is ascribed in the research design. The relationship of research methods and approaches to evaluation is discussed and the potential contribution of qualitative research methods is outlined.

Attitude of Health Personnel↗
PubMed1989

Functional assessment of infant breastfeeding patterns.

As breastfeeding rates have increased in the United States, the need has arisen for coordinated approaches to the assessment of normal and problem situations. Since some difficulties are related to the manner in which baby feeds, guidelines are discussed for the visual assessment of breastfeeding. These include the when, why, and how of assessing seven common situations or problems: initial breastfeeding experiences, inadequate infant weight gain or low milk intake, insufficient milk supply (real or perceived), nipple problems, latch-on and sucking disorganization, high-risk situations, and the good baby syndrome.

Breast Feeding↗
PubMed1989

Management of selected early breastfeeding problems seen in clinical practice.

Management guidelines for six common clusters of breastfeeding situations or problems commonly seen in clinical practice are discussed. These include inadequate infant weight gain, insufficient milk supply, nipple problems, latch-on and sucking disorganization, high-risk situations, and the "good baby" syndrome. Charts are provided describing devices and specialized techniques from which to choose when creating a feeding plan.

Breast Feeding↗
PubMed1989

Diurnal variations in serum biochemical and haematological measurements.

Twenty five biochemical and haematological measurements were determined on nonfasting blood and serum samples collected between 9 am and 7 pm from a representative group of 7685 British middle-aged men. Most measurements showed significant diurnal variations, but only for bilirubin, phosphate, and triglyceride did time of day account for more than 5% of the between subject variance. Serum bilirubin concentrations showed a pronounced downward trend in the afternoon, the mean value after 6 pm being 30% lower than the mean value in the morning. Mean serum triglyceride and phosphate concentrations increased steadily through the day. Mean concentrations of potassium, haemoglobin, and haematocrit and red cell count were higher in the morning, while urea and creatinine concentrations and white cell count had higher means in the afternoon. Glucose showed a pattern consistent with short term response to meals. The effects of these diurnal trends on routine use of biochemical tests needs careful consideration, and a greater understanding of their biological mechanisms is required.

Adult↗
PubMed1989

Measurements of acute cerebral infarction: lesion size by computed tomography.

As part of a prospective therapy study of 65 patients with acute, nonhemorrhagic, cerebral infarction, computed tomographic scans of the head were obtained at admission, 7-10 days, and 3 months. The scans were analyzed for the presence, site, size, and volume measurement of the infarction. At 7-10 days, the mean infarction volume as measured by computed tomography was 55 cm3 or about 4 x 4 x 3.5 cm (range = 0-507 cm3). At 3 months, the mean infarction volume decreased by 25% to 41 cm3. For the 26 scans showing infarction at the time of admission, the mean lesion volume was 33 cm3 at admission, 51 cm3 at 7-10 days, and 49 cm3 at 3 months. With lesion size at 7-10 days expressed as percentage of total brain volume, the mean infarction size was only 5%. Of the 49 patients with lesions revealed by computed tomography at 7-10 days, 20 had an infarction of 1% or less of total brain volume, while only six had an infarction of 20% or more of total brain volume. The lesion volumes as measured by the 7-10-day computed tomography correlated with the neurologic examination scores on admission (Spearman's rank-order correlation = 0.78) and with the scores at 1 week (Spearman's rank-order correlation = 0.79).

Acute Disease↗
PubMed1989

Distinctive role of IgG1 and IgG3 isotypes in Fc gamma R-mediated functions.

Polyclonal and monoclonal anti-Rh (D) antibodies of IgG1 and IgG3 subclass were evaluated for their capacity to sensitize erythrocytes and (i) to trigger monocyte and K-cell mediated antibody-dependent cellular cytotoxicity (ADCC); (ii) to mediate binding to monocyte and lymphocyte Fc gamma R; (iii) to stimulate phagocytosis by monocytes. All antibodies were equally effective in mediating monocyte or activated U937 cell ADCC but IgG1 was more active than IgG3 in K-cell mediated ADCC. IgG3-sensitized erythrocytes inhibited IgG1-induced lysis, suggesting that each subclass engages the same Fc gamma R receptor but that lysis requires a further 'signal' that the IgG3 molecule can not deliver. Two monoclonal IgG3 anti-D antibodies were shown to have higher binding (two times) and phagocytic (three times) indices than IgG1 antibody for monocytes; similar differences were observed for polyclonal IgG1 and IgG3 antibodies. The same pattern was observed in an EA rosette assay when a total lymphocyte population was used; however, this difference was not seen with a B-cell depleted (T+ null cell) lymphocyte population.

Antibodies, Monoclonal↗
PubMed1989

Redundant colon and carcinoma of the right colon.

The combination of redundant colon, multiple villose, adenomas, and a colloid adenocarcinoma arising in one villous adenoma in a black man is rare. The authors report such a case.

Adenocarcinoma, Mucinous↗
PubMed1989

A protocol for outpatient management of asymptomatic human immunodeficiency infection.

The epidemic of HIV infection and its consequences are being increasingly encountered by primary care community physicians. The management of these patients is especially challenging. Presented here is a protocol that utilizes a flow chart for laboratory and treatment decisions and a checklist highlighting signs and symptoms to look for in regular office visits of HIV patients. Matters of legality, physicians' responsibility, insurance, lifestyle management, and prevention of opportunistic infections are discussed. The use of zidovudine (AZT) and alternative drugs is reviewed. More understanding of the special needs of HIV patients will enable the primary care physician to better serve the future needs of his community.

Clinical Protocols↗