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Biomedical subjects

M A Maher

Publications and source records attributed to M A Maher.

7 recordsLinked to original sources
PubMed1999

Evaluation of graduates of an associate degree nursing program.

Approximately 58% of the RN nursing programs in the United States are associate degree programs (ADN). The curricula of these programs are designed to prepare graduates to competently provide direct patient care. The purpose of this descriptive comparative study was to evaluate the nursing performance of ADN graduates as perceived by graduates, faculty, and employers. In the first phase of the study, graduates and faculty completed the Six-Dimension Scale of Nursing Performance (6-DSNP) at the time of graduation. Six months later, the graduates again were asked to complete the same questionnaire along with their employers. Findings indicated a significant difference in the planning and evaluation performance of graduates at graduation and 6 months later as perceived by the graduates. Graduates rated themselves significantly higher in all areas of performance when compared to faculty and employers. There was no significant difference in the perception of graduate performance between faculty and employers. This outcome assessment provides needed data on perceptions of ADN programs.

Adult↗
PubMed1998

Chromium picolinate modulates rat vascular smooth muscle cell intracellular calcium metabolism.

We have previously shown that insulin attenuates vasoconstriction, accelerates both vascular relaxation and [Ca2+]i recovery from pressor agonist-induced Ca2+ loads, and stimulates Ca2+-ATPase gene expression in rat and human vascular smooth muscle cells (VSMC). Moreover, these functions are impaired in VSMC from both insulin resistant and insulinopenic rats, suggesting that hypertension in insulin resistant states may result, in part, from impaired insulin-regulation of VSMC Ca2+ transport. Accordingly, we have now evaluated the effect of improving cellular insulin sensitivity with chromium picolinate (CrPic) on regulation of VSMC Ca2+ transport. Cultured VSMC from rats were grown from passage to confluence in the presence or absence of 1 micromol/L CrPic, maintained in a quiescent medium for 24 h and incubated with or without insulin (10(-8) mol/L) for the final 2 h. Cells were then harvested and RNA and protein extracted for Northern and Western blot analysis, respectively. Insulin caused a significant stimulation of plasmalemmal Ca2+-ATPase mRNA and protein (P < 0.05). A comparable stimulation of the mRNA and protein levels was caused by CrPic in the absence of insulin (P < 0.05), while the CrPic + insulin treatment caused a greater percentage stimulation of the Ca2+-ATPase mRNA level than either separate treatment (P < 0.05). Fluorometric analysis of the rate of [Ca2+]i recovery following stimulation with arginine vasopressin support these findings: insulin caused an 83% increase, CrPic caused a 35% increase and insulin + CrPic caused a 133% increase in [Ca2+]i recovery rate. These data suggest that CrPic may be an effective modality to reduce VSMC [Ca2+]i loads and thereby reduce peripheral vascular resistance in insulin resistant states.

Animals↗
PubMed1996

Dietary fat and sex modify heterozygote effects of the rat fatty (fa) allele.

Rats carrying one copy of the obesity gene fa may exhibit intermediate phenotypes between lean (+/+) and homozygous mutants (fa/fa). Previous data suggested to us that fa heterozygotes may be more sensitive than wild-type rats to high fat diets. To test this hypothesis, we generated +/+ and fa/+ rats and fed them diets containing 12% or 48% energy as fat for 7 wk. Energy efficiency was significantly greater in males than in females and in high fat-fed vs. low fat-fed rats. Perirenal fat pad weights were significantly greater in males than in females, in high fat-vs. low fat-fed rats and in fa/+ vs. +/+ rats. Adipose and soleus plasma membrane calcium-ATPase concentrations were significantly lower in rats fed the high fat diet. This protein was also lower in soleus of fa/+ rats compared with +/+ rats. There were significant diet x genotype interactions such that the high fat diet had the greatest effect on fat pads and calcium-ATPase in fa/+ rats. The results of the present study show heterozygote effects of the fa allele and suggest that these effects may be modulated by both sex-related factors and dietary manipulation.

Adipocytes↗
PubMed1996

Adipose tissue stearoyl-CoA desaturase mRNA is increased by obesity and decreased by polyunsaturated fatty acids.

Stearoyl-CoA desaturase (SCD) is a key regulatory enzyme in the synthesis of unsaturated fatty acids. Although regulation of hepatic SCD by obesity and polyunsaturated fatty acids (PUFA) has been well investigated, no studies have addressed whether similar regulation occurs in adipose tissue. We addressed these questions by feeding control (12% corn oil) and high-PUFA (48% corn oil) diets to lean and obese Zucker rats and analyzing SCD mRNA levels in adipose tissue and liver. We report that SCD mRNA content was dramatically elevated in adipose tissue of obese vs. lean rats on both diets and was significantly decreased by PUFA in both genotypes. Interestingly, we demonstrate that SCD expression was directly downregulated in a dose dependent manner by PUFA in 3T3-L1 adipocytes. We conclude that 1) obese Zucker rats overexpress the SCD gene in both liver and adipose tissue and 2) PUFA directly suppress SCD expression in adipocytes. Further studies will elucidate the mechanisms responsible for obesity- and PUFA-mediated regulation of SCD in adipose cells.

Adipocytes↗
PubMed1995

Variations of blood pressures in lean Zucker rats fed low or high fat diets.

The purpose of this study was to determine whether lean (Fa/?) Zucker rats which exhibit greater metabolic efficiency in response to a high (48%) fat diet also exhibit hypertension.Twenty-nine lean (Fa/?) and eleven obese (fa/fa) Zucker rats were fed low (12% energy) and high (48% energy) fat diets. Food intake and weight change were recorded weekly to obtain an index of energy efficiency. After 6 wk, direct intra-arterial blood pressure was measured in conscious, unrestrained animals. Arterial blood was collected for analyses of plasma insulin and glucose. The high fat diet had no effect on blood pressure in obese rats, although obese animals fed both diets had significantly higher blood pressure than lean siblings. High fat feeding in lean rats unmasked a heterogeneity in blood pressure. Blood pressure in this group was significantly correlated with weight change, energy efficiency ratio and plasma glucose concentration. Lean rats fed the high fat diet with blood pressures above the group median exhibited significantly greater plasma insulin (P < 0.02) and glucose (P < 0.01) concentration and energy efficiency ratios (P < 0.01) than those with lower blood pressures. Thus, it appears that there were two groups of lean animals present, one of which was more phenotypically sensitive to high fat feeding than the other. This suggests a possible gene dosage effect of the fa allele in the Zucker rat model.

Animals↗
PubMedDate not supplied

Monkey versus human performance in the NCTR Operant Test Battery.

A battery of operant behavioral tasks, designed to monitor complex "cognitive" functions in monkeys, was adapted for use in children. Adaptations were then incorporated into the monkey battery so that monkeys and children performed exactly the same tasks. Food pellets served as reinforcers for monkeys; nickels for children. Correct responding in a task is thought to depend upon relatively specific brain functions including short-term memory and attention, learning, time perception, motivation, and color and position discrimination. Eight 4-year-old rhesus monkeys served as subjects, and groups (n = 10 to 20) of 4- to 8-year-old children were recruited if they were not known to have any neurological, academic or behavioral problems. In performance of only the learning task was there any significant difference between monkeys and children. This difference was in response rate (not accuracy), with the monkeys responding faster than children. This lone difference in operant responding between monkeys and children was likely due to the fact that monkeys generally use all four appendages to respond whereas children generally do not.

Animals↗