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Biomedical subjects

M A Wilson

Publications and source records attributed to M A Wilson.

At least 325 records · Page 18Linked to original sources
PubMed1972

Biochemical heterogeneity of rat liver mitochondria separated by rate zonal centrifugation.

1. Rat liver mitochondria were separated on the basis of their sedimentation coefficients in an iso-osmotic gradient of Ficoll-sucrose by rate zonal centrifugation. The fractions (33, each of 40ml) were collected in order of decreasing density. Fractions were analysed by spectral analysis to determine any differences in the concentrations of the cytochromes and by enzyme analyses to ascertain any differences in the activities of NADH dehydrogenase, succinate dehydrogenase and alpha-glycerophosphate dehydrogenase. 2. When plotted as% of the highest specific concentration, the contents of cytochrome a+a(3) and cytochrome c+c(1) were constant in all fractions but cytochrome b was only 65% of its maximal concentration in fraction 7 and increased with subsequent fractions. As a result, the cytochrome b/cytochrome a+a(3) ratio almost doubled between fractions 7 and 25 whereas the cytochrome c+c(1)/cytochrome a+a(3) ratio was unchanged. 3. Expression of the dehydrogenase activities as% of highest specific activity showed the following for fractions 6-26: NADH dehydrogenase activity remained fairly constant in all fractions; succinate dehydrogenase activity was 62% in fraction 6 and increased steadily to its maximum in fraction 18 and then decreased; the activity of alpha-glycerophosphate dehydrogenase was only 53% in fraction 6 and increased slowly to its peak in fractions 22 and 24. 4. These differences did not result from damaged or fragmented mitochondria or from microsomal contamination. 5. These results demonstrate that isolated liver mitochondria are biochemically heterogeneous. The importance of using a system for separating biochemically different mitochondria in studies of mitochondrial biogenesis is discussed.

Animals↗
PubMedDate not supplied

Ro 15-1788-induced seizures in rats continually exposed to diazepam for prolonged periods.

Previous reports using rats have failed to demonstrate convulsions upon withdrawal from chronic benzodiazepine (BZ) treatment. We have shown earlier that rats develop tolerance to benzodiazepines following continuous exposure to low levels of diazepam (DZ) obtained by treatment with s.c. diazepam-filled silastic capsules. This report shows that intravenous infusion of the benzodiazepine antagonist Ro 15-1788 can induce seizures in rats treated for prolonged periods (4 weeks) with such diazepam-filled capsules. Precipitated seizures are also seen in rats 24 h after the cessation of chronic diazepam exposure. This procedure may provide a useful paradigm with which to study in rats the neural changes which are related to the physical dependence and withdrawal associated with prolonged exposure to the benzodiazepines.

Animals↗
PubMedDate not supplied

DNA sequence and expression analysis of root-knot nematode-elicited giant cell transcripts.

Fifty-eight cDNA clones isolated from a library of transcripts exhibiting up regulation in tomato root giant cells induced by infection with the parasitic nematode Meloidogyne incognita were characterized. A survey of plant tissues identified 31 transcripts present in tissues other than root, including actively dividing and expanding tissues and mature leaf tissues. The identities of approximately 20% of the giant cell transcripts were inferred from DNA sequence data; they include sequences encoding a plasmalemma proton ATPase, a putative Myb-type transcription factor, and the largest subunit of RNA polymerase II.

Amino Acid Sequence↗
PubMedDate not supplied

The gap between practice and genetics education of health professionals: HuGEM survey results.

PURPOSE: To determine the genetics education needs and priorities of dietitians, occupational therapists, physical therapists, psychologists, speech-language-hearing specialists, and social workers. METHODS: A random sample mail survey of 3,600 members of 6 national health professional organizations was undertaken in 1998 and resulted in 1,958 responses. RESULTS: A majority worked with clients with genetic conditions, most were providing genetic services to some clients, few had high confidence in providing genetic services, most had little or no education in genetics, and two-thirds wanted continuing education. CONCLUSION: The study shows a critical need for genetics education of allied and counseling health professionals.

Adult↗
PubMedDate not supplied

Dental erosion: a case study of a marathon runner.

This paper presents a case study of a recreational runner who unwittingly has caused severe damage to her dentition through her lifestyle and dietary habits. It should serve as a reminder to all dental practitioners that dental problems occur even in patients who seem to be following a healthy lifestyle.

Beverages↗
PubMedDate not supplied

Major and trace elements of selected pedons in the USA.

Few studies of soil geochemistry over large geographic areas exist, especially studies encompassing data from major pedogenic horizons that evaluate both native concentrations of elements and anthropogenically contaminated soils. In this study, pedons (n = 486) were analyzed for trace (Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Zn) and major (Al, Ca, Fe, K, Mg, Na, P, Si, Ti, Zr) elements, as well as other soil properties. The objectives were to (i) determine the concentration range of selected elements in a variety of U.S. soils with and without known anthropogenic additions, (ii) illustrate the association of elemental source and content by assessing trace elemental content for several selected pedons, and (iii) evaluate relationships among and between elements and other soil properties. Trace element concentrations in the non-anthropogenic dataset (NAD) were in the order Mn > (Zn, Cr, Ni, Cu) > (Pb, Co) > (Cd, Hg), with greatest mean total concentrations for the Andisol order. Geometric means by horizon indicate that trace elements are concentrated in surface and/or B horizons over C horizons. Median values for trace elements are significantly higher in surface horizons of the anthropogenic dataset (AD) over the NAD. Total Al, Fe, cation exchange capacity (CEC), organic C, pH, and clay exhibit significant correlations (0.56, 0.74, 0.50, 0.31, 0.16, and 0.30, respectively) with total trace element concentrations of all horizons of the NAD. Manganese shows the best inter-element correlation (0.33) with these associated total concentrations. Total Fe has one of the strongest relationships, explaining 55 and 30% of the variation in total trace element concentrations for all horizons in the NAD and AD, respectively.

Geological Phenomena↗