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Biomedical subjects

P A Martin

Publications and source records attributed to P A Martin.

At least 19 recordsLinked to original sources
PubMed1995

Finding time for research.

If nurses wish to conduct research and there is no time, they can try these tools, and they probably will reclaim some time to do research. Make research activity a priority, find some collaborators, use opportunities to make one task meet multiple goals, and garner available resources to lighten the load.

Nursing Research↗
PubMed1995

Perineal descent at defecography in women with straining at stool: a lack of specificity or predictive value for future anal incontinence?

OBJECTIVE: To determine (1) whether patients complaining of straining at stool have pelvic floor descent and anal abnormalities similar to those of patients with anal incontinence and (2) whether these patients are prone to develop anal incontinence. METHODS: To answer the first question we used defecography to study perineal floor position at rest, during maximal contraction of the anal sphincter and during straining, and we performed anorectal manometry in 46 women with straining at stool but without anal incontinence at the beginning of the study, and in 46 women with idiopathic anal incontinence, matched for age. To answer the second question, we performed a 5-year follow-up study to determine whether anal incontinence had developed in those women with straining at stool. RESULTS: Perineal floor position at rest, during maximal contraction of the sphincter and during straining, resting pressure in the upper part of the anal canal, maximal amplitude and duration of the voluntary contraction were similar in the 46 women with straining at stool and the 46 women with idiopathic anal incontinence. In the follow-up study, 24 of the 46 women with straining at stool were contacted. The incidence of anal incontinence after 5 years was higher among these 24 women than in a control group of 20 women (13 out of 24 versus three out of 20, for women with straining at stool versus controls respectively; P < 0.01). The 13 patients with straining at stool who became incontinent had, at the initial investigation, a lower maximal amplitude of voluntary contraction, greater perineal descent at rest and less elevation of the pelvic floor during maximal contraction of the anal sphincter than the other women (P < 0.05). CONCLUSION: Women with chronic straining at stool have perineal descent at rest and during straining similar to that of incontinent women. Women with chronic straining are also prone to develop anal incontinence, suggesting that perineal descent at defecography in women with straining at stool may predict future anal incontinence.

Aged↗
PubMed1994

Responsibilities when a patient is a research subject.

Subject recruitment must be performed with attention to subject rights and research protocols. Subject retention is critical to a good study, but continued participation must be voluntary (Raudonis, 1992). Good communication and support can benefit both subjects and researcher. The RN must know the agency's policies and procedures that guide in caring for a patient who is also a research subject. Attention must be paid to improving communications with the researcher.

Communication↗
PubMed1994

Building a local research consortium.

Although state, regional, and national networking often are critical to the nurse researchers, local support that is broader than what is found in any single agency may be the foundation needed by clinicians who want "more" research than that prescribed by their current role. More formal consortiums have successfully implemented a variety of research projects and are another possibility to explore (Beaman & Strader, 1990; Bolton, 1991; Chenitz et al., 1990; Keefe et al., 1988; Thiele, 1989). Another option is some state nurses' associations that have formal research assemblies (eg., Ohio Nurses Association, Assembly of Nurse Researchers). However, forming a local, less formal group with a few expert advisors may supply the energy and momentum necessary for both using and conducting research at a grassroots level. The expert advisors should be research-trained nurses (almost always with a PhD or DNS) who are active group members. Although Fitzpatrick encouraged collaborative research and writing early in the history of Applied Nursing Research (Fitzpatrick, 1989), in 1993 approximately two thirds of the articles in Applied Nursing Research still were single authored. Nurses are not using collaboration to its fullest extent. An informal group in one community has been one way to release the scholarship that was latent in many nurses.

Nursing Research↗
PubMed1994

A formal method of determining the dietary amino acid requirements of laying-type pullets during their growing period.

1. The amino acid requirements of laying type pullets during the growing period can be estimated by measuring the growth of different components of the body and making use of nutritional constants that define the amount of each amino acid that is required for the production of the tissues being formed. 2. In this experiment, carcase analyses of each of three breeds of pullets were conducted at weekly intervals throughout the growth of the pullets, to 18 weeks of age. Measurements were made of body weight, gut-fill and feather weight, and chemical analyses consisted of water, protein, lipid and ash measurements of both the body and the feathers. Each age group comprised 10 birds of each breed. 3. Gompertz functions accurately estimated the growth of both body protein and feather protein, to 18 weeks of age, from which the rate of growth of these two components of the body could be estimated. The mature weight of pullets was overestimated by the Gompertz growth curve, which may indicate that a pullet ceases to increase in body protein content once sexual maturity has been reached. 4. Using allometric relationships between the chemical components of the body and of feathers, all the components of growth could be estimated from the growth of body protein and feather protein. These components were then added together to determine the growth rate of the body as a whole. 5. The daily amino acid requirements for 4 functions were calculated, namely, those for the maintenance of body protein and feather protein, and for the gain in body protein and feather protein. These requirements were then summed to determine the requirement of pullets on each day of the growing period. 6. Using the 'effective energy' system, the amount of energy required by these pullets was calculated for each day of the growing period, from which the desired daily food intake of the pullets could be predicted. By dividing the amino acid requirement by this daily food intake it was possible to determine the concentration of amino acids that would be needed in the diet in order to meet the requirements of a pullet. 7. The results indicate that the ratio between the requirement for lysine and for methionine and cysteine changes dramatically during the growing period, negating the concept of a fixed ratio between all the amino acids during growth.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1993

Effects of glucagon-like peptide-1(7-36)amide on the concentrations of insulin and glucose in sheep.

1. The effects of glucagon-like peptide-1(7-36)amide (GLP-1) and/or glucose on the concentration of insulin in fed and starved sheep were studied. Insulin concentrations in starved sheep increased with increasing doses of GLP-1 (0.23-2.27 nmol) when given together with glucose. 2. Hyperglycaemia was necessary for GLP-1 to stimulate increases in serum insulin but the level required was low (0.4 mmol/l or less). 3. In fed sheep hyperglycaemia alone caused an increase in serum insulin. 4. GLP-1 improved the ability of both fed and starved sheep to remove exogenous glucose from the circulation. 5. GLP-1 did not augment insulin secretion in response to other known insulin secretagogues.

Animals↗
PubMed1993

Effects of consumption of milk and milk constituents on plasma concentrations of gastric inhibitory polypeptide and metabolites in preruminant goat kids.

Plasma concentrations of gastric inhibitory polypeptide (GIP) were measured in preruminant goat kids before and after consumption of milk, skimmed milk or solutions of milk fat, lactose, glucose or casein plus lactose. GIP concentrations increased significantly within 1 h of consumption of milk or milk fat, and were elevated for the remainder of the 5-h sampling period. The integrated mean change in GIP concentration during this period did not differ between these two meals. GIP levels were slightly increased above basal values 5 h after skimmed milk consumption, probably reflecting the absorption of a small amount of fat, but overall there was no significant GIP response to this or to any of the other test meals. The marked increase in GIP concentration after a milk feed indicates a physiological role for the hormone in preruminants but, in contrast to the situation in simple-stomached animals, carbohydrate absorption does not elicit GIP secretion in the preruminant goat. The data strongly suggest that fat is the major nutrient to stimulate GIP secretion in these animals.

Administration, Oral↗
PubMed1992

Magnetic resonance spectroscopy and imaging of muscle--a physiological approach.

Magnetic resonance spectroscopy (MRS) and imaging (MRI) are now well established techniques for the study of cellular metabolism and gross structure of muscle. Using non-ferrous materials, we have constructed a system for the measurement of isometric force of quadriceps in response to percutaneous electrical stimulation and voluntary effort within the bore of a 48 cm diameter 1.5 T General Electric SIGNA whole body MR system. Using this system we have been able to study the relationship between electromechanical coupling and chemistry of muscle, with 31P MRS for the measurement of high-energy phosphates and pH, during electrically stimulated activity. Image analysis using the Context Vision system enables a distinction to be made, in 1H MRI by T1/T2 mapping, of muscle, fat and connective tissue to give force per unit cross sectional area of muscle. The combination of MR and functional measurements provide a valuable tool for further detailed analysis of human muscle weakness and fatigue.

Electric Stimulation↗
PubMed1992

Relationship between selected bacteria and the growth of immature house flies, Musca domestica, in an axenic test system.

To investigate the relationship between immature (maggot) house flies, Musca domestica, and bacteria, we compared the development of sterile first-instar maggots in each of 10 pure blood agar cultures of bacteria with growth on sterile blood agar (negative control) and on standard house fly rearing medium (positive control). Nine species of bacteria representing gram-negative and gram-positive rods, coccoid, and micrococcoid cell types supported house fly growth on blood agar. One bacterium, a strain of Bacillus cereus, inhibited maggot growth. The percent pupation for maggots that developed in the presence of eight of nine bacteria (range, 41-69%), was significantly greater than in sterile blood agar (0-5%), and did not differ significantly from maggot growth in the rearing medium (50-90%). Average pupal weight for maggots that developed on blood agar with bacteria ranged from 19 to 21 mg, a reflection of favorable growth conditions. Average pupal weight in the presence of three bacteria (19.9, 19.4, and 19.4 mg) was significantly less than respective pupal weights in house fly rearing medium (24.0, 22.3, and 22.1 mg), but there was no difference in average pupal weight with six bacteria and the house fly rearing medium. These findings illustrate that bacteria or their metabolic products are essential as nutrients for house fly maggot growth in blood agar; a wide variety of adventitious bacteria can contribute to the suitability of an organic substrate for maggot growth; and a naturally occurring isolate of B. cereus limits house fly maggot growth in blood agar, a relationship that has not been reported previously.

Animals↗
PubMed1992

Changes in the plasma concentration of gastric inhibitory polypeptide and other metabolites in response to feeding in sheep.

Plasma concentrations of gastric inhibitory polypeptide (GIP)-like activity were determined in sheep before and after refeeding following a 48-h fast. Plasma concentrations increased significantly after feeding, from about 250 pg/ml to about 550 pg/ml. Other metabolites in plasma also increased at this time, reflecting the absorption of nutrients from the gastrointestinal tract. Significant increases were observed in the plasma concentrations of acetate, beta-hydroxybutyrate and triacylglycerol. By comparing the time-courses of the changes in concentration of GIP and other metabolites in plasma, possible sites of secretion and secretagogues of GIP in ruminant animals are proposed. The results demonstrate that GIP is secreted in response to nutrient absorption in adult ruminants and that, as in simple-stomached animals, the absorption of long-chain free fatty acids plays an important role in this secretion.

3-Hydroxybutyric Acid↗
PubMed1991

Energy metabolism during damaging contractile activity in isolated skeletal muscle: a 31P-NMR study.

Creatine kinase (CK) release in response to excessive electrically stimulated contractile activity has been studied in isolated rat soleus muscles. The exacerbation of CK release induced by contractile activity was found to be directly related to the length of time for which the muscle was stimulated and indirectly related to the recovery of force following the end of stimulation. 31P-NMR studies were undertaken using a recirculating superfused muscle preparation and demonstrated that muscles subjected to two different stimulation protocols (stimulation for 0.5 s every 2 s in oxygenated medium or for 1.5 s every 2 s in anoxic medium) had similar falls in ATP content and pH despite a substantially greater release of CK from the muscles stimulated under anoxia. However, stimulated muscles under anoxia showed a more rapid fall and reduced recovery of phosphocreatine and a greater sustained elevation of inorganic phosphate than muscles in oxygenated medium. It is concluded that only part of the increased loss of CK from muscles stimulated in anoxic medium can be explained by release from cells which have lost energy supplies and therefore that other mechanisms must exist which allow release of CK and other cytosolic enzymes from muscle cells.

Adenosine Triphosphate↗