Search PubMed⌕ Search

Biomedical subjects

M Smith

Publications and source records attributed to M Smith.

At least 649 records · Page 36Linked to original sources
PubMed1994

Phenotypic variation of tuberous sclerosis in a single extended kindred.

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder with a great degree of phenotypic variability. Given the presence of two gene loci underlying this disorder, locus heterogeneity may account for some of the variability. However, significant within family variation suggests that different genes do not explain the majority of this variation. The purpose of this research is to identify physical and behavioural variation in expression of TSC in a single large extended kindred. TSC in this kindred is cosegregating with markers localised to chromosome 16p13.3. The expression of TSC in this kindred is quite variable with a substantial proportion of persons showing very mild physical expression of TSC. In contrast to very mild physical expression of TSC in some family members, there is a significant clustering of psychiatric disorders among persons affected with TSC compared to their unaffected relatives. This finding, coupled with the mild physical expression of TSC in some family members, supports a hypothesis that the TSC2 gene may present phenotypically as mild skin signs and significant behavioural problems.

Adolescent↗
PubMed1994

Imaging and differential diagnosis of the large eye.

The initial step in the differential diagnosis of an enlarged eye is to determine whether an intraocular mass is present. The globe may be expanded by a mass, seen mainly in children with retinoblastoma. Buphthalmos with or without neurofibromatosis also enlarges the eye. Diffuse enlargement may be associated with a connective tissue disorder or be related to axial myopia. Focal enlargement represents staphyloma, which can be unilateral or bilateral. In the presence of one small eye, the normal-sized eye may be incorrectly diagnosed as large.

Diagnosis, Differential↗
PubMed1994

Role of redox systems on Fe3+ uptake by transformed human intestinal epithelial (Caco-2) cells.

Caco-2 cells were used as a model of human intestinal epithelium to investigate the role of redox systems in transepithelial transport of 59Fe3+. The cells reduced Fe3+ present in the apical medium; the reduction was 50% inhibited by adriamycin and p-chloromercuribenzoate. Addition of [14C]ascorbate to the basolateral medium resulted in accumulation of 14C radioactivity in both cells and apical medium; apical radioactivity increased with time and was probably caused by paracellular flux. The cells provided Fe3+ reduction capacity to the apical incubation medium. Addition of ascorbate to the basolateral medium increased this reduction capacity 2-fold and the cellular uptake of 59Fe3+ 1.8-fold. Adriamycin significantly inhibited both cellular 59Fe uptake and Fe transport into the basolateral side. The results indicate that Caco-2 cells reduce apical Fe3+ by two parallel mechanisms: by a plasma membrane ferrireductase and by the secretion of reductants of either cellular or basolateral origin. The data support a model for Fe3+ intestinal absorption in which cell-mediated Fe3+ reduction occurs before cellular Fe uptake.

Ascorbic Acid↗
PubMed1994

Strength training increases resting metabolic rate and norepinephrine levels in healthy 50- to 65-yr-old men.

Resting metabolic rate (RMR) decreases with age, largely because of an age-related decline in fat-free mass (FFM). We hypothesized that a strength-training program capable of eliciting increases in FFM would also increase RMR in older individuals. To test this hypothesis, RMR, body composition, and plasma concentrations of certain hormones known to affect RMR were measured before and after a 16-wk heavy-resistance strength-training program in 13 healthy men 50-65 yr of age. Average strength levels, assessed by the three-repetition maximum test, increased 40% with training (P < 0.001). Body weight did not change, but body fat decreased (25.6 +/- 1.5 vs. 23.7 +/- 1.7%; P < 0.001) and FFM increased (60.6 +/- 2.2 vs. 62.2 +/- 2.1 kg; P < 0.01). RMR, measured by indirect calorimetry, increased 7.7% with strength training (6,449 +/- 217 vs. 6,998 +/- 226 kJ/24 h; P < 0.01). This increase remained significant even when RMR was expressed per kilogram of FFM. Strength training increased arterialized plasma norepinephrine levels 36% (1.1 +/- 0.1 vs. 1.5 +/- 0.1 nmol/l; P < 0.01) but did not change fasting glucose, insulin, or thyroid hormone levels. These results indicate that a heavy-resistance strength-training program increases RMR in healthy older men, perhaps by increasing FFM and sympathetic nervous system activity.

Aged↗
PubMed1994

Investigation of the nucleolar organizer regions in Alzheimer's disease.

The Ag-stained nucleolus organizer regions and the satellite association (SA) were studied in peripheral lymphocyte cultures derived from 10 patients with Alzheimer's disease (AD), 10 elderly controls and 10 young controls. Our results showed a significant lower frequency of Ag staining and SA in relation to the chromosome pair 21 in the AD patient group when compared with the elderly and young control groups. These results point to a reduction in the activity of ribosomal genes in the AD patient group.

Adult↗
PubMed1994

Ways to promote successful training.

With today's financial cutbacks, long-term care facilities are looking for low-cost ways to help nurses meet licensing requirements. In-house training can be one economical way, but getting employees involved is another challenge.

Attitude of Health Personnel↗
PubMed1994

Caring and curing.

Explore the source record for details and available documents.

Communication↗
PubMed1994

Palliative care in the home. The GP/home hospice team.

The family doctor has always had a significant role in caring for terminally ill patients. Giving support to patients in their last few weeks or hours of life can be an emotionally demanding, clinically frustrating, time-consuming task. The advent of home palliative care services has given patients, families and doctors access to a home hospice team that can provide invaluable support.

Family Practice↗
PubMed1994

Development and significance of nucleoside drug resistance in infection caused by the human immunodeficiency virus type 1.

Nucleoside antagonists of human immunodeficiency virus (HIV) reverse transcriptase (RT) activity have been commonly used in the therapy of HIV-associated disease. The prolonged use of such drugs has led to the development of HIV variants that display resistance against these compounds. HIV drug resistance has been documented clinically for each of the following nucleosides: 3'-azido-3'-deoxythymidine (AZT; zidovudine, ZDV), 2',3'-dideoxyinosine (ddI; didanosine), and 2',3'-dideoxycytidine (ddC; zalcitabine). In addition, resistance has been demonstrated against a series of non-nucleoside inhibitors of the viral RT. Several groups have documented that a series of point mutations within the HIV pol gene, that encodes the RT enzyme, is responsible for HIV drug resistance. Diminished sensitivity to anti-viral drugs results from both the selective pressure exerted by these compounds in individuals receiving prolonged therapy and the error-prone nature of the viral RT itself, thus permitting the outgrowth of mutated forms. Patients suffering from both disease progression and/or low CD4 counts are most likely to develop HIV drug resistance.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Vascular endothelial growth factor, platelet-derived growth factor, and insulin-like growth factor-1 promote rat aortic angiogenesis in vitro.

The purpose of this study was to evaluate the vasoformative response of isolated vascular explants to a variety of growth factors that have been shown to stimulate angiogenesis. Rings of rat aorta were cultured in collagen gels under serum-free conditions in the presence or absence of vascular endothelial growth factor (VEGF), natural platelet-derived growth factor (PDGF), PDGF-AA, PDGF-BB, insulin-like growth factor-1 (IGF-1), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta 1 (TGF-beta 1), epidermal growth factor (EGF), interleukin-1 alpha (IL-1 alpha), or hepatocyte growth factor (HGF). The angiogenic response of the rat aorta was stimulated by VEGF, PDGF, PDGF-AA, PDGF-BB, and IGF-1. Maximum stimulatory effects were obtained with VEGF and PDGF-BB. By contrast, TGF-beta 1 and IL-1 alpha had inhibitory activity. No significant effects were observed with TGF-alpha, EGF, or HGF. The vascular outgrowth of VEGF-stimulated cultures was primarily composed of microvessels, whereas that of PDGF- and IGF-1-stimulated cultures contained an increased number of fibroblast-like cells. The inability of TGF-alpha, TGF-beta 1, IL-1 alpha, EGF, and HGF to stimulate rat aortic angiogenesis in serum-free culture suggests that either these factors require the mediatory activity of accessory cells that are not present in the rat aorta model or that blood vessels are heterogeneous in their capacity to respond to different angiogenic factors.

Animals↗