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Biomedical subjects

G Martin

Publications and source records attributed to G Martin.

At least 217 records · Page 12Linked to original sources
PubMed1994

An overview of the rationale, process, and nursing implications of peripheral blood stem cell transplantation.

Peripheral blood stem cell transplantation (PBSCT) is the process of removing circulating stem cells from the peripheral blood through apheresis and returning these cells to the patient after dose-intensive chemotherapy. Clinical trials using PBSCT and dose-intensive chemotherapy are underway at cancer centers across the country. Nurses caring for patients who are undergoing PBSCT need an understanding of all aspects of the process in order to competently manage the toxicities, as well as to educate patients, families, and other staff. Nurses need to consider issues for nursing research to improve the quality of life for these patients.

Antineoplastic Agents↗
PubMed1994

Guiding patients and their families through peripheral stem cell transplantation with the help of a teaching booklet.

PURPOSE/OBJECTIVE: To present a booklet designed to educate patients and their families about peripheral blood stem cell transplantation (PBSC). DATA SYNTHESIS: The booklet describes the procedure, self-care, preliminary chemotherapy regimens, necessary follow-up tests, and appropriate resources. CONCLUSIONS: Preliminary evaluation indicates the booklet has been well-received and appreciated by patients and nursing staff alike. IMPLICATIONS FOR NURSING PRACTICE: The booklet supplements basic patient education in regard to PBSC, anticipates patient questions, and provides patients and families with a take-home, written resource.

Aftercare↗
PubMed1993

Communication between patients with breast cancer and health care providers. Determinants and implications.

BACKGROUND: This study evaluated the perceptions of patients with breast cancer of their medical interactions with providers. The determinants and psychological consequences of communication problems also were examined. METHODS: Ninety-seven patients with Stage I or II breast cancer completed a set of validated questionnaires before initiating postoperative therapy. Data on psychological distress were collected at baseline and 3-month follow-up, and multivariate models were fit to explain the relationship between pretreatment communication problems and subsequent psychological distress. Data on clinical variables were abstracted from medical records. RESULTS: A substantial proportion of patients (84%) reported difficulties communicating with the medical team. Communication problems were more common among patients who were less optimistic about their disease and had less assertive coping styles. Patient-reported communication problems were associated with increased anxiety, depression anger, and confusion at the 3-month follow-up. The association between communication problems and mood disturbance remained significant, although small, after adjusting for baseline mood disturbance, demographic, clinical, and coping style variables. CONCLUSION: Interventions that enhance communication between patients with breast cancer and their providers may improve patients' psychological adjustment to treatment. Conversely, interventions that lower distress and modify coping style may enhance communication.

Adaptation, Psychological↗
PubMed1993

Isolation and molecular characterization of a hyperglycemic neuropeptide from the sinus gland of the terrestrial isopod Armadillidium vulgare (Crustacea).

The major peptide from the sinus gland of the terrestrial isopod Armadillidium vulgare (Crustacea) has been extracted and purified by reverse-phase HPLC. This neuropeptide exhibited a high hyperglycemic activity and was therefore named A. vulgare crustacean hyperglycemic hormone (Arv-CHH). Its average molecular mass measured by mass spectrometry was 8729.3 Da. Its complete amino acid sequence was determined by a combination of Edman degradation and mass spectrometry. The N-terminal amino acid was found to be unblocked, the C-terminal residue was found amidated and none of the other 72 residues was affected by any post-translational modification. Disulfide bond assignment was made unambiguously by mass spectrometry and Edman degradation was performed on peptides produced by enzymatic cleavage. Relationships with other, similar neuropeptides from decapod sinus glands are discussed.

Amino Acid Sequence↗
PubMed1993

A simple model for alanine metabolism in isolated rat hepatocytes.

A simple model describing reactions of alanine metabolism in isolated hepatocytes from fasted rats is proposed and applied to radioactive data obtained in experiments in which L-[1-14C]-, L-[2-14C]-, L-[3-14C]-, and L-[U-14C]alanine as well as L-alanine plus NaH14CO3 were used as substrates in parallel. Measurements of the rates of incorporation of the label into glucose and CO2 and of accumulation of [1-14C]pyruvate, [1-14C]lactate, [1-14C]alanine and [1-14C]glutamate plus [1-14C]glutamine from the different substrates used allows to calculate flux of alanine carbon through the various metabolic steps taken into account in the model. The validity of this model is indicated by the agreement found between calculations and measurement of the 14CO2 released from [1-14C]alanine as well as between the values of flux through pyruvate carboxylase calculated in two different ways. It is shown that the oxaloacetate synthesized by pyruvate carboxylase enters into the Krebs cycle and into the pathway of phosphoenolpyruvate synthesis in about equal proportions and that about 40% of the oxaloacetate synthesized as a result of alanine metabolism is derived from the Krebs cycle operation. These results, together with the conclusion that flux of alanine carbon through pyruvate dehydrogenase is negligible, are in agreement with known characteristics of hepatic alanine metabolism in the fasted state and, therefore, provide further evidence for the validity of the model proposed in the present study.

Alanine↗
PubMed1993

Older women as the focus for research and treatment of ovarian cancer. An overview for the National Institute on Aging, National Cancer Institute, and American Cancer Society Multidisciplinary Working Conference.

Ovarian cancer disproportionately affects women 65 years of age and older who are likely to have concomitant changes in physical ability, physiological functioning, and other chronic conditions associated with advancing age. The National Institute on Aging, National Cancer Institute, and the American Cancer Society cosponsored a multidisciplinary working conference, "Perspectives on Ovarian Cancer in Older-Aged Women: Current Knowledge and Recommendations for Research," at the National Institutes of Health on November 20-21, 1991 to confront the age-related aspects of ovarian cancer in epidemiology, etiology, clinical investigations, and patient management. Conference participants devoted attention to such special topics as drug resistance, dose intensity, patterns of care, and screening potential for ovarian cancer. After exploring these areas with existing data, the task was then to generate recommendations for research and practice. The scope of the conference and an introduction to the proceedings are presented in this paper.

Aged↗
PubMed1993

Effect of intravenous dopamine on blood pressure and plasma insulin in hypertensive patients.

Eleven patients with moderate to severe hypertension were pre-treated with oral labetalol 800-1200 mg/day for one week, prior to receiving two i.v. infusions of dopamine 1-3 micrograms/kg/min each of 30 min each, before and after the i.v. bolus injection of metoclopramide 30 mg. There were washout periods before and after the metoclopramide administration. Dopamine induced a significant decrease of blood pressure from 172/104 to 153/94 mm Hg without altering heart rate, and it increased the plasma insulin level from 8.3 to 12.1 microU.ml-1. Metoclopramide did not itself affect blood pressure or plasma insulin, but it did block the hypotensive response and rise in plasma insulin due to dopamine. We conclude that the pharmacological actions of intravenous dopamine on the cardiovascular system and on insulin secretion may be mediated by dopaminergic receptor stimulation.

Blood Glucose↗
PubMed1993

Adolescent suicide: music preference as an indicator of vulnerability.

OBJECTIVE: This preliminary study investigated possible relationships between adolescents' music preference and aspects of their psychological health and lifestyle. METHOD: Students (mean age 14.76 years) from two randomly chosen high schools completed self-report questionnaires on preferred music types and messages in the music. In addition the Youth Self-Report provided information about suicide ideation, deliberate self-harm, "depression," and "delinquency." Brief risk taking and drug taking scales were administered in addition to questions about family environment. RESULTS: A marked gender bias was shown to exist with 74% of girls preferring pop music compared with 70.7% of boys preferring rock/metal. Significant associations appear to exist between a preference for rock/metal and suicidal thoughts, acts of deliberate self-harm, "depression," "delinquency," drug taking, and family dysfunction. This was all particularly true for girls. In addition, feeling sadder after listening to the preferred music appeared to distinguish the most disturbed group. CONCLUSIONS: The authors recommend that further academic study of these associations is warranted. Both preference for rock/metal music, particularly in girls, and feeling worse after listening to the music may be indicators in adolescents of vulnerability to suicidal thoughts and actions.

Adolescent↗
PubMed1993

Locus of control as an indicator of risk for suicidal behaviour among adolescents.

Using a sample of high school students, this pilot study investigated the relationship between locus of control and a range of suicidal behaviours, the proportion of high school students in an Australian sample who report having engaged in such behaviours and the proportion of suicide attempters who received medical attention following an attempt. Two hundred male and 205 female students aged between 13 and 19 years (mean = 15, SD = 1), attending one randomly chosen metropolitan state high school, completed a questionnaire that included demographic details, the Nowicki-Strickland Locus of Control Scale for Children and questions concerning suicide. The findings indicated that a substantial proportion of individuals in the sample have suicidal ideation. A smaller proportion have engaged in a range of more serious and overt self-destructive and suicidal behaviours. Further, a majority of attempters in the sample had not received medical attention following their attempt. There was also a clear association between locus of control and suicidal behaviour, with the individuals who had engaged in suicidal behaviours characterized by a more external locus of control orientation. This study adds further weight of evidence to the suggestion that the locus of control construct is useful in identifying adolescents at risk of engaging in suicidal behaviour.

Adolescent↗
PubMed1993

Ontogeny of small intestinal glutaminase and glutamine synthetase in the rat: response to dexamethasone.

The ontogeny of small intestinal glutaminase (GA) and glutamine synthetase (GS) was studied with relation to the maternal administration of dexamethasone (DEX). Pregnant Sprague-Dawley rats were administered 0.2 mg/kg of DEX or saline twice daily on days 19 and 20 of gestation. Activity of GA did not increase from the fetus to the 10-day-old rat; however, GS activity increased 7-fold. DEX induced doubling of GA activity and mRNA, but only a slight increase is GS activity and mRNA was observed in the fetus. GA and GS activities appear to be regulated by different mechanisms.

Animals↗
PubMed1993

Effects of dopaminergic antagonists on dopamine-induced cardiovascular and insulin secretion actions in hypertensive patients.

A comparative study between two dopaminergic antagonists: metoclopramide and domperidone, was undertaken in nineteen (19) hypertensive patients at the Vargas Hospital, Caracas. The patients were pretreated with labetalol, 800-1,200 mg/day, orally, over a period of one week, after which they were divided into two groups: group A, a total of eleven patients were intravenously infused with dopamine hydrochloride 0.5-3 micrograms/kg/min, before and after treatment with metoclopramide (10 mg, i.v. as a bolus); group B (n = 8), was pretreated with domperidone, 20 mg b.i.d., p.o. over a period of one week and intravenously infused with dopamine hydrochloride, 0.5-3 micrograms/kg/min. In group A, dopamine induced a decrease of blood pressure from 171.9 +/- 6.35/103.6 +/- 3.12 to 152.7 +/- 7.55/93.8 +/- 2.97 mmHg (p < 0.001) without altering heart rate, and it increased plasma insulin levels from 8.29 +/- 0.70 microunits/ml to 12.09 +/- 1.83 microunits/ml (p < 0.01). Metoclopramide caused no changes of blood pressure or plasma insulin levels. However, hypotensive responses and plasma insulin rises due to dopamine were blocked by metoclopramide. In group B, domperidone also blocked dopamine-induced antihypertensive effect (from 170.0 +/- 9.23/102.8 +/- 3.80 to 160.2 +/- 9.84/95.5 +/- 2.50 mmHg) although it was less effective than metoclopramide. Domperidone also blocked dopamine-induced increase of plasma insulin levels from 9.65 +/- 4.50 microunits/ml to 11.78 microunits/ml. We conclude that a dopaminergic receptor may be involved in some cardiovascular responses and in modulating insulin secretion in man.

Blood Glucose↗
PubMed1993

Effect of calcium antagonists on endothelin-induced contraction of isolated human resistance arteries: differences related to site of origin.

Small resistance arteries were isolated from human subcutaneous fat and omentum and studied using a myograph. Endothelin-1 induced a concentration-dependent contraction in both type of arteries. In subcutaneous arteries preincubation with calcium antagonists partially inhibited responses to endothelin-1. The effectiveness of the calcium antagonists was nisoldipine > nimodipine > verapamil = flunarizine > diltiazem. In omental arteries nimodipine and diltiazem had no significant effect on endothelin-1-induced contraction and removal of extracellular calcium also had little effect on responses to endothelin-1. The role of influx of extracellular calcium through voltage operated calcium channels in endothelin-1-induced contraction appear to differ between subcutaneous and omental resistance arteries.

Adipose Tissue↗
PubMed1993

Effect of butter, mono- and polyunsaturated fatty acid-enriched butter, trans fatty acid margarine, and zero trans fatty acid margarine on serum lipids and lipoproteins in healthy men.

The effect of diets containing 50% of fat calories from butter, butter enriched with mono- and polyunsaturated fatty acids, and margarines with and without trans fatty acids on the serum lipids of 38 healthy men in a free-living condition have been determined. Serum lipid responses to the high level of individual dietary fats were unexpectedly small. The butter diet produced a small, but significant rise (5%) in the total serum cholesterol and low density lipoprotein (LDL)-cholesterol, relative to all other diets. Enrichment of butter with either olive oil (50/50) or sunflower oil (50/50) failed to reduce serum lipid levels below habitual diet values. Hard margarine, containing 29% trans fatty acids, caused a decrease in apolipoprotein A-I and B levels, but did not change total serum cholesterol or LDL-cholesterol levels, relative to habitual diet values. A soft margarine, high in linoleate, with no trans fatty acids reduced total cholesterol, LDL-cholesterol, and apolipoprotein B significantly, relative to all diets. Soft margarine high density lipoprotein (HDL)-cholesterol levels remained unchanged, but apolipoprotein A-I values were decreased relative to habitual and butter diets. The quantities of saturated fatty acids and the sum of monounsaturated and polyunsaturated fatty acids consumed on the hard and soft margarines were equal; therefore, the different response of serum cholesterol and LDL-cholesterol between these two diets is attributable to the trans fatty acids in the hard margarine. The data indicate that trans fatty acids are not metabolically equivalent to the natural cis isomers and that they affect the serum lipid profile adversely.

Adult↗
PubMed1992

Glycine, a new regulator of glutamine metabolism in isolated rat-liver cells.

Glycine (0.1-10 mM) caused a dose-dependent increase in the removal of 5 mM [1-14C]glutamine by isolated rat-liver cells; at low concentrations of glycine, an increase in the formation of 14CO2, urea and glucose from glutamine occurred. At 2-10 mM, glycine also caused an accumulation of ammonia, a well-established activator of glutaminase (E.C. 3.5.1.2) and, at concentrations found in the presence of glutamine plus glycine, ammonia stimulated glutamine removal. The inhibition of urea synthesis from glutamine observed with 10 mM glycine was relieved by the addition of ornithine, suggesting that this inhibition occurred by reducing the availability of ornithine for the ornithine transcarbamoylase reaction. The metabolism of glycine as sole substrate led to a small increase in the accumulation of ammonia. Glycine did not alter hepatic glutaminase activity but swelling of rat hepatocytes, a factor considered to stimulate glutamine metabolism, was observed in the presence of glycine (1 mM). It is concluded that stimulation by glycine of hepatic utilization of glutamine is mediated by the accumulation of ammonia arising from both glycine and glutamine metabolism and by hepatocyte osmotic swelling secondary to glycine transport.

Ammonia↗