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Biomedical subjects

D Barnes

Publications and source records attributed to D Barnes.

214 records · Page 12Linked to original sources
PubMed1976

Stimulation of sugar uptake in cultured fibroblasts by epidermal growth factor (EGF) and EGF-binding arginine esterase.

Mouse epidermal growth factor causes a rapid increase in 2-deoxyglucose uptake in stationary phase mouse (3T3) cells or human fibroblasts. Maximum effect is approximately two fold over control levels for 3T3 cells and about 50% over controls for human fibroblasts. Maximum effect on 3T3 cells is seen about two hours after addition of 10 ng/ml EGF to the culture medium. Stimulation is easily measureable within the first fifteen minutes after addition of the hormone and may be detected at hormone concentrations as low as 0.1 ng/ml. The EGF-binding arginine esterase found associated with EGF in the mouse submaxillary gland causes an enhancement of the EGF effect. In serum-free medium, the EGF effect is still readily observed, but no enhancement by the esterase is seen. SV40 virus-transformed 3T3 cells show no effect on deoxyglucose uptake after addition of 10 ng/ml EGF to the culture medium, but a response may be demonstrated after these cells are incubated for 12 hours or more in serumless medium. EFG stimulates transport of 3-O-methylglucose in stationary phase 3T3 and human fibroblasts but no EGF stimulation of alpha-amino-isobutyrate uptake in 3T3 cells is seen under conditions is reproted to inhibit intracellular degradation of human EGF by human fibroblasts, does not diminish the EGF effect on deoxyglucose uptake in human fibroblasts.

Aminoisobutyric Acids↗
PubMed1976

The lead, copper and zinc content of tree rings and bark. A measurement of local metallic pollution.

Analysis of samples of wood taken from different tree rings for lead by atomic absorption spectrometry showed that there was little correlation between the sample site or ring age and air borne lead concentrations. However, the concentration of lead in tree bark at several sites was particularly sensitive to traffic flow at that site. The concentration of lead, zinc and copper in the tree bark decreased with increased distance from the road and with height above the ground. The method offers a simple technique for effectively tracing atmospheric metal concentrations.

Air Pollutants↗
PubMedDate not supplied

QT dispersion in microalbuminuric Type 1 diabetic patients without myocardial ischemia.

Microalbuminuria is associated with an increased risk of cardiac death. We assessed whether urinary albumin excretion is related to abnormalities of the QT interval independently of myocardial ischemia. Thirty-four patients with type 1 diabetes who were free from ischemic heart disease on the basis of normal stress electrocardiography and echocardiography were studied. Maximal QT interval and dispersion were significantly greater in the group with microalbuminuria (n=17) compared to controls (n=17) with normal urinary albumin excretion (394 [26.1] vs. 373.8 [27.8] ms; P=.044 and 62.4 [21.8] vs. 42.7[11.6] arbitrary units; P=.009). Autonomic function was similar between the groups. Urinary albumin excretion correlated positively with QT dispersion (P=.023). These data suggest that in type 1 diabetic patients, QT abnormalities can occur independently of autonomic dysfunction or myocardial ischemia and may be related to the processes which increase urinary albumin leakage.

Adult↗
PubMedDate not supplied

Fish embryo cell cultures for derivation of stem cells and transgenic chimeras.

It has been demonstrated in mammalian systems that techniques using embryonal stem cells provide advantages over conventional injection of DNA into embryos for generation of transgenic animals. We employed cell culture approaches in an attempt to develop this technology for fish transgenesis. Using a trout embryo-derived mitogenic preparation in a specialized culture medium, we initiated replication of zebrafish blastula-derived cell cultures and expressed marker genes introduced into the cells by plasmid transfection. Reintroduction of cells from the cultures into blastula-stage embryos indicated that the cultured cells survived and may contribute to the developing organism.

Animals↗
PubMedDate not supplied

Factors affecting the tolerance of muscle circulation and function for increased tissue pressure.

The tolerance of neuromuscular tissue for increased tissue pressure has been observed clinically to vary among individuals. In experimental operations on rabbits, various factors may affect tissue pressure tolerance. Arterial hypoxia, halothane anesthesia, local arterial occlusion, and acute hemorrhage each reduced the amount of pressure necessary to produce circulatory and functional deficits. Extrapolation of these observations suggest that patients with hemorrhage, arterial hypoxia, and peripheral vascular disease may be at greater risk from a given tissue pressure than patients without these conditions.

Action Potentials↗
PubMedDate not supplied

Multicultural considerations in the use of advance directives.

PURPOSE/OBJECTIVES: To describe advance directives and the Patient Self-Determination Act (PSDA), to explore the European American sociocultural values underlying advance directives, and to describe the ethical and cultural issues that arise when attempting to encourage and use advance directives in culturally diverse populations. DATA SOURCES: Research articles, case studies, and theoretical articles from clinical and bioethical literature. DATA SYNTHESIS: An overview of advance directives and the PSDA is provided. The European American cultural values underlying advance directives are reviewed and contrasted with sociocultural values of culturally diverse groups to raise the question of cross-cultural applicability of advance directives and European-based bioethics. CONCLUSIONS: The sociocultural values of many culturally diverse groups conflict with the values on which the use of advance directives is based. Thus, working with end-of-life decisions and advance directives for people from culturally diverse groups may be problematic. IMPLICATIONS FOR NURSING PRACTICE: Nurses should be sensitive to sociocultural beliefs that influence decisions affecting end-of-life care, especially the use of advance directives. Practitioners must incorporate this knowledge to increase flexibility of institutional practices and standards of care in the application of advance directives.

Advance Directives↗