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Biomedical subjects

R A Anderson

Publications and source records attributed to R A Anderson.

At least 235 records · Page 13Linked to original sources

Handling health-care costs in the '90s.

Managed-care programs with utilization reviews may be the best approach to cost cutting. But to really curb costs, providers, insurers, employers and employees must form partnerships to overcome the outrageous inflation in the U.S. health-care system.

Cost Control↗

The relationship between size and parity status of field collected Culiseta melanura.

The relationship between body size and parity status of adult female Culiseta melanura collected from 3 locations in northeastern United States was studied by measuring wing lengths and examining ovaries of individual mosquitoes. Virus isolation was attempted from Cs. melanura collected in Maryland and in New Jersey. At all 3 locations, the size of Cs. melanura collected varied from large in the spring, to small in the summer. In New Jersey and Maryland mosquitoes collected in the fall were again large. The size of Massachusetts mosquitoes collected in the summer versus the fall was not different. In general, parous mosquitoes were larger than nulliparous mosquitoes in the spring but smaller than nulliparous ones in the fall. Eastern equine encephalomyelitis (EEE) and Highlands J (HJ) viruses were recovered from Cs. melanura only during the late summer when mosquitoes were small or during the fall months when larger mosquitoes were collected. We conclude that there is no detectable association between Cs. melanura size and parity status and that there is no obvious effect of mosquito size on EEE or HJ virus transmission.

Animals↗

Body size variation of Culiseta morsitans in relation to vector potential for eastern equine encephalomyelitis virus.

Variation in the body size of wild Culiseta morsitans collected from Massachusetts was examined. No significant size variation was detected at any time during the collection period, nor was there a significant size difference between parous and nulliparous mosquitoes. We conclude that size variation in this species does not affect survivorship, an important aspect of vectorial capacity.

Animals↗

Objective assessment of meconium content of amniotic fluid.

The amount of meconium in amniotic fluid is subjectively estimated by visual inspection and classified as thin (light), moderate, or thick (heavy). This estimate may be important for assessing the neonatal risk of perinatal asphyxia and meconium aspiration syndrome. This study reports on the "meconium-crit," a simple, rapid, inexpensive, and reproducible method of quantifying meconium concentration in amniotic fluid. The purpose of the study was to determine the relationship between the meconium-crit and meconium concentration. Specimens were prepared by placing 3.0 g of fresh neonatal meconium into clear amniotic fluid and vortexing for 15 minutes to obtain a stock solution of 15.0 g meconium/100 mL amniotic fluid. Stock solutions were then diluted with clear amniotic fluid to obtain concentrations of 10.0, 7.5, 5.0, 3.0, and 1.5 g/100 mL. One-tenth milliliter of the amniotic fluid/meconium mixture was drawn into a standard hematocrit tube and centrifuged. The meconium-crit was then measured directly as with a hematocrit. Regression analysis indicated that meconium-crit values were linearly related to meconium concentration (r = 0.901-0.995). This method provides a reproducible means of quantifying meconium in amniotic fluid.

Amniotic Fluid↗

HLA-DRB1 and -DRB4 genes are differentially regulated at the transcriptional level.

The mechanism regulating the differential expression of DR beta 1 and DR beta 4 proteins on the surfaces of cultured EBV-transformed DR7 cell lines was investigated at the level of gene transcription. Steady-state levels of mRNA coding for DR7 beta 1 and DR beta 4 proteins were evaluated with the use of locus-specific oligonucleotide probes and relative transcriptional activity at the DR7B1 and DRB4 gene loci was measured with nuclear run-on transcription assays. Steady-state levels of DR7B1 mRNA were found to be three- to nine-fold higher than those of DRB4 in DR7,Dw7 cell lines, but no mature steady-state DRB4 mRNA was detectable in a DR7,Dw11 cell line which shows no detectable DR beta 4 protein. Run-on transcription assays performed with nuclei isolated from DR7,Dw7 cells showed a five-fold excess of DRB1 over DRB4 transcriptional activity, but, surprisingly, no difference in activity at the two DRB loci in nuclei isolated from DR7,Dw11 cells. Both DRB mRNA were quite stable as indicated by actinomycin D time course experiments. Thus the differential expression of the DR7 beta 1 and DR beta 4 proteins in the DR7,Dw7 cell lines arises at the level of mRNA production; the lack of detectable DR beta 4 protein in the DR7,Dw11 cell line, however, appears to be due to a different mechanism in which transcribed DRB4 sequences fail to be processed into mature mRNA molecules.

Blotting, Northern↗

Essentiality of chromium in humans.

Chromium is an essential nutrient required for normal sugar and fat metabolism. Insufficient dietary chromium is associated with maturity-onset diabetes and/or cardiovascular diseases. Dietary chromium intake in the U.S. and other developed countries is roughly half of the minimum suggested intake of 50 micrograms. Well controlled studies involving human subjects have demonstrated beneficial effects of supplemental chromium on fasting glucose, glucose tolerance, blood lipids, insulin binding, and hypoglycemic blood glucose values and symptoms. Since chromium is a nutrient and not a therapeutic agent, it will only benefit those people whose signs and symptoms are due to marginal or overt chromium deficiency. Stresses including high sugar diets, strenuous exercise, physical trauma, infection and certain diseases exacerbate the signs and symptoms associated with marginal intakes of dietary chromium. While excessive levels of chromium are usually limited to industrial settings, marginal dietary chromium intake is widespread in the general population and may lead to serious health problems.

Chromium↗

Restriction fragment length polymorphisms associated with abnormal lipid levels in an adolescent population.

The association of restriction fragment length polymorphism genetic markers at the apolipoprotein AI-CIII-AIV gene locus with lipid and lipoprotein levels was evaluated in subsets of the 666 Caucasian students from the junior high school (11-14 years old) population of Muscatine, Iowa. Male students whose leukocyte DNA had an uncommon haplotype consisting of the minor allele of a SacI restriction site polymorphism (S2) in combination with the more common allele of an MspI site variation (M1) had significantly lower levels of high density lipoprotein (HDL)-cholesterol (P less than 0.05) when compared to a random sample of males; these levels were stable over a 2-year follow-up. The minor allele of an XmnI restriction site polymorphism (X2) was more frequent in females with triglyceride levels in the upper decile of the age and gender-specific triglyceride distribution than in normotriglyceridemic females (0.10 less than P less than 0.15) and triglyceride levels were higher in random sample females with an X2 allele than in X1 homozygotes (P less than 0.10). These results suggest that alleles of the known apolipoprotein genes (AI, CIII, AIV) at this locus or closely linked gene sequences may have major effects on lipid levels in members of the general population.

Adolescent↗

Biochemical and structural evidence for ethanol-induced impairment of testicular development: apparent lack of Leydig cell involvement.

The present study was conducted to provide biochemical and morphological evidence for ethanol-induced impairment of testicular development. The specific activities of testicular postmeiotic enzyme markers--sorbitol dehydrogenase (SDH), lactate dehydrogenase (LDH), and alpha-glycerophosphate dehydrogenase (GDH)--increased with age in CFW mice from ages 23 to 60 days, providing a biochemical measure of testicular development during puberty. Chronic ethanol treatment via liquid diets from ages 20 to 55 days resulted in decreased activities of SDH and LDH at ages 40 and 44 days, and of GDH at ages 34, 40, and 44 days. These decreases were consistent with an arrest in the developmental increase in SDH, LDH, and GDH at ages 31 +/- 0.6, 31 +/- 2.6, and 24 +/- 0.5 days, respectively. After 29 days of ethanol treatment (age 50 days), testicular weights, epididymal sperm content, and sperm motility were reduced, relative to controls, by 37, 83, and 60%, respectively (p less than 0.05). Epididymal weights were unaffected. Light microscopic evaluation of testes revealed disorganization of spermatogenesis, germ cell degeneration, decreased tubular luminal diameter, and vacuolation of Sertoli cells in ethanol-treated mice at age 50 days. Electron microscopic analysis showed that germ cell degeneration was not restricted to a specific cell type. Stage IX-XI tubules were observed in which spermatids had been retained and underwent phagocytosis within the Sertoli cell. Sertoli cells showed evidence of atypical nuclear invaginations. Sertoli cells underwent degenerative changes and were sloughed into the rete testis. However, relative Leydig cell size, as well as fractional volume occupied by the nucleus, mitochondria, and endoplasmic reticulum were unaffected by ethanol. The data (1) confirm previous findings suggesting ethanol-induced delayed testicular development; (2) suggest that certain aspects of testicular development are arrested relatively early in ethanol treatment (4-11 days); and (3) indicate that the Sertoli cell, rather than the Leydig cell, is the primary target with regard to the deleterious effect of chronic ethanol treatment on testicular maturation.

Administration, Oral↗

Testosterone production by the prepubertal mouse testis is not depressed by ethanol.

The purpose of the present study was to evaluate the sensitivity of testicular steroidogenesis during pubertal development to inhibition by ethanol. In vivo and in vitro human chorionic gonadotropin (hCG)-stimulated steroidogenesis were examined in CFW mice as a function of age. Plasma androstenedione, testosterone, and dihydrotestosterone (DHT) increased from ages 23 to 60 days in control mice. Acute ethanol treatment (3 g/kg) yielded static levels of androstenedione (0.45 +/- 0.03 ng/mL), testosterone (6.4 +/- 0.56 ng/mL), and DHT (2.3 +/- 0.18 ng/mL) from ages 23 to 60 days, 30 to 60 days, and 35 to 60 days, respectively, resulting in reduction of plasma androstenedione, testosterone, and DHT (P less than 0.05) relative to control values, but not until ages 35, 50, and 45 days, respectively. A similar insensitivity of the prepubertal testis to ethanol was seen in vitro. Inhibition of in vitro androstenedione and testosterone accumulation was seen only after ages 26 and 45 days, respectively. The data indicate that testosterone production by the pubertal testis is relatively insensitive to direct inhibition by ethanol. Previous studies have shown that chronic ethanol treatment of adolescent mice delays testicular maturation. The present study suggests that if chronic ethanol-induced delayed testicular development were due to impaired steroidogenesis, such impairment would be secondary to reduced gonadotropin stimulation and/or due to a chronic, rather than an acute, effect of ethanol.

Aging↗

Ethanol-induced delayed male puberty in mice is not due to impaired Leydig cell function.

The present study was performed to evaluate the involvement of reduced testosterone in ethanol-induced impairment of male reproductive tract development. In vivo and in vitro gonadotropin (hCG)-stimulated steroidogenesis were examined in CFW mice as a function of chronic ethanol treatment during pubertal development. Chronic ethanol treatment from ages 20 to 49 days impaired testicular growth from ages 35 days (29 +/- 2 mg vs 37 +/- 2 mg for pair-fed controls) to 50 days (42 +/- 2 mg vs 63 +/- 2 mg for pair-fed controls). Consistent with a reduction in testicular weight, testicular content of androstenedione, testosterone, and dihydrotestosterone (DHT) was depressed in ethanol-treated mice. At age 50 days, the content (expressed as pg/testis) of androstenedione, testosterone, and DHT was reduced in ethanol-treated animals by 49%, 31%, and 38%, respectively, as compared to that of their respective controls. However, no difference in plasma (ng/mL) or testicular (pg/mg protein) concentrations of steroids was observed. Except for the DHT response at ages 35 to 40 days, neither in vivo nor in vitro steroidogenesis was impaired by chronic ethanol treatment at ages 26 to 50 days; similarly, the acute ethanol effect on steroidogenesis was unaffected. However, an adaptive increase (54%-173%) in the in vivo testosterone response to hCG was seen at ages 26 to 40 days. The data indicate that 1) chronic ethanol treatment does not impair gonadotropin-stimulated steroidogenesis or result in tolerance to acute ethanol effects on steroidogenesis in older animals; and 2) ethanol-induced reduction in testosterone is not a likely mechanism for delayed sexual maturation.

Aging↗

Exercise training and dietary chromium effects on glycogen, glycogen synthase, phosphorylase and total protein in rats.

The effects of exercise training and dietary chromium intake on rat liver and muscle glycogen metabolism, tissue and body weight and feed consumption were examined. After 16 wk of training, liver, gastrocnemius and biceps femoris glycogen concentrations were higher in the trained compared to sedentary groups, independent of dietary chromium. There was a chromium x training interaction on glycogen synthase activities in the liver and gastrocnemius muscle. Liver glycogen phosphorylase activities (expressed per g liver) were lower in the chromium-supplemented rats as compared to the non-supplemented rats after 5 wk of dietary treatment, but were similar after 8 wk and higher after 18 wk. Gastrocnemius phosphorylase activity (expressed per mg protein) was lower in the trained rats as compared to the sedentary rats after 16 wk, independent of dietary chromium. Biceps femoris phosphorylase activities were not altered due to training or dietary chromium. Total protein concentration increased in the liver but decreased in the gastrocnemius due to dietary chromium. In summary, liver glycogen synthase and phosphorylase activities were dependent upon dietary chromium. Dietary chromium altered gastrocnemius synthase, but not phosphorylase activities. Changes in enzyme activities may be related to the chromium-dependent effects on liver protein and the chromium and training-dependent effects on gastrocnemius total protein.

Animals↗

Demystifying the boardroom. Tips for timid trustees.

The complexity of a modern hospital can mystify and intimidate trustees; they may have difficulty understanding how the hospital works and thus may feel unable to contribute to its success. Stripping away some of the mystery may enable them to more effectively fulfill their roles to "hold in trust" and "govern." Some strategies trustees can use to gain control include hiring a chief executive officer (CEO) who can communicate, remembering who works for whom, assuming that anyone who makes more than $80,000 a year expects to earn it, and stifling the urge to seek "fairness." To clarify the relationship between board and CEO, trustees should ask the following questions: Are all subsystems contributing to the system's overall goals, or are some serving their own ends? Does the system allow interaction among subsystems to promote synergy, or does it isolate the parts? How does the CEO plan to produce the required product or service and achieve profit goals within the organizational policies? How will the trustees know whether the intended product or service has been produced within the organizational policies at the desired profit? By following a code of conduct, trustees will become more effective. The seven elements of the code include observing behaviors and reporting observations, asking questions and insisting on clear answers, establishing relationships with constituencies, making decisions and being willing to explain those decisions, making sure solutions fit problems, realizing that management is a series of approximations, and seeing that adherence to the hospital's mission dominates the criteria used in free choices.

Communication↗

A theory development role for nurse administrators.

Nurse administrators can formulate useful theories while solving the complex problems of practice. An awareness of the mental perspective that frames one's thoughts about experiences can aid in theory development. Examples are developed to illustrate how different mental perspectives lead to different theories, decisions, and outcomes. It is argued that a system perspective, when used as an aid for conceptualizing experiences, will assist nursing administrators in developing theories that address their comprehensive sphere of activity and influence.

Administrative Personnel↗

Dual degree. Future preparation for nurse executives?

What is the best educational preparation for top-level nurse executives? Which educational degrees will improve marketability? These questions were asked of nurse executives and their chief executive officers in a national market survey. The authors discuss the results of the survey which provides information that may be useful in selecting educational programs and in planning and revising graduate curriculum.

Administrative Personnel↗