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Biomedical subjects

R K Young

Publications and source records attributed to R K Young.

At least 19 recordsLinked to original sources
PubMed1995

Duplicate publication in the nursing literature.

The purpose of this study was to identify examples of duplicate publication in the nursing literature and determine what types of duplicate articles are published. From the sample of 642 articles published by 77 authors during a 5-year period, 181 articles were classified as duplicate. Forty-one authors published at least one form of duplicate article. Fifty-nine duplicate articles did not reference the primary article. Duplicate publication itself is not unethical, but duplicate publication without referencing duplicate work is unethical and may violate copyright law.

Authorship↗
PubMed1994

High frequency of Gag- and envelope-specific cytotoxic T lymphocyte precursors in children with vertically acquired human immunodeficiency virus type 1 infection.

Circulating human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTL) are seen less frequently in unstimulated peripheral blood mononuclear cells (PBMC) from children with vertically acquired HIV infection than in PBMC from HIV-infected adults. HIV-1 Gag-, reverse transcriptase (RT)-, and envelope (Env)-specific cytotoxic activity was studied in PBMC from HIV-infected children. Only 9% of subjects had Gag- or RT-specific CTL in unstimulated PBMC. However, in PBMC studied after CD3 stimulation, Gag- and Env-specific CTL were found in PBMC from 91% and 78% of HIV-infected children, respectively. Limiting dilution analysis of precursor CTL (pCTL) frequencies in PBMC from children > 12 months old demonstrated Gag- and Env-specific pCTL frequencies from 0.5 to 6.3/10,000 PBMC and from 0.66 to 33.0/10,000 PBMC, respectively. Thus, children with vertically acquired HIV infection have high frequencies of HIV-specific pCTL.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Inhibition of human immunodeficiency virus type 1 replication in vitro by the bisheteroarylpiperazine atevirdine (U-87201E) in combination with zidovudine or didanosine.

The bisheteroarylpiperazine nonnucleoside reverse transcriptase (RT) inhibitor atevirdine effectively inhibits human immunodeficiency virus type 1 (HIV-1) in vitro. Clinical isolates with a wide range of 50% inhibitory concentrations (IC50s) of zidovudine (IC50, 0.003 to > 2.0 microM) and didanosine (IC50, 0.02 to > 10.0 microM) were inhibited by atevirdine (median IC50, 0.74 microM; range, 0.06-1.60). Cross-resistance to atevirdine in zidovudine- or didanosine-resistant isolates was not observed. Combinations of atevirdine and zidovudine were highly synergistic against zidovudine-resistant clinical isolates of HIV-1. By contrast, these combinations were mostly additive when tested against zidovudine-susceptible isolates. Combinations of atevirdine and didanosine were additive in their effects against both didanosine-susceptible and -resistant isolates. These data suggest that the interaction of atevirdine with HIV-1 RT is different than that of other nonnucleoside RT inhibitors and that combinations of atevirdine and zidovudine may be useful in patients with AIDS who have initially received monotherapy with zidovudine.

Antiviral Agents↗
PubMed1991

Washing, drying, and anointing in adult humans (Homo sapiens): commonalities with grooming sequences in rodents.

Very few behavioral patterns generalize across human and nonhuman species. We describe washing, drying, and anointing sequences in humans (Homo sapiens) that may have analogies with other species. The rank ordering of washing, drying, and anointing body parts was obtained over 3 successive days for 37 men and 60 women. Variation in rank ordering of body parts was nonrandom, and a cephalocaudal progression was evident for each behavior. Reliability of the behaviors as well as the correlations across rankings were highly significant, which indicates a generalized cephalocaudal progression for all 3 behaviors. Women's anointing was most variable, which suggests a more specific function. The cephalocaudal action pattern described for humans is similar to that for Mongolian gerbils and laboratory rats. Cross-species functions, such as these, may add to our understanding of common developmental and learning processes.

Adult↗
PubMed1988

Movement initiation characteristics in young adult rats in relation to the high- and low-affinity agonist states of the striatal D2 dopamine receptor.

Changes in the speed of movement initiation as a function of age, brain damage, or rat strain are associated with altered characteristics of nigrostriatal dopamine (DA) neurons and of striatal D2 DA receptors. In the present study we investigated the relationship between movement initiation (response parameters: percent of successful responses and response latency) and the agonist binding states of the D2 DA receptor in corpus striatum in 3-month-old Sprague-Dawley rats (n = 51). In contrast to the typical experimental procedure, the variances of the behavioral and receptor binding data were intentionally made as small as possible to provide the most stringent test of putative relationships among variables. Rats were trained to release a lever as rapidly as possible in response to a light/buzzer (CS) combination in order to avoid a mild footshock (UCS). Percent avoidance scores, latencies of the fastest successful trials (successful latencies) and mean latencies for all responses (mean latencies) were collected for 1000-, 500-, 300- and 200-ms CS-UCS intervals. Twenty-four hours following the last behavioral test, animals were euthanized for measurements of the high- and low-affinity binding of DA to D2 receptors in corpus striatum. The standard errors of the mean for both behavioral and receptor binding parameters were, generally, less than 10%. The tightness of the receptor binding data appeared to be related to a lack of biological variance in the animals rather than to an artifact associated with the behavioral testing procedure, since a parallel experiment indicated that different numbers of behavioral shaping sessions had no effects on striatal D2 binding characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Scales for measuring fear of AIDS and homophobia.

Two scales, one for measuring attitudes toward the fear of Acquired Immune Deficiency Syndrome (AIDS) and one for measuring attitude toward homosexuality, were constructed using Thurstone's method of equal-appearing intervals. After construction, the scales were given to 528 students at the University of Texas at Austin in the fall of 1985 to determine their respective reliabilities. Factor analyses were also done to determine what factors underlie the attitudes measured by the two scales and to determine if fear of AIDS and homophobia are in fact simply two facets of the same attitude: fear of homosexuals. The results indicated high reliabilities of both scales and a relatively low correlation between the two scales suggesting that the scales do measure different attitudes.

Acquired Immunodeficiency Syndrome↗
PubMed1986

The effect of age on plasma zinc uptake and taste acuity.

Plasma uptake of a 25 mg oral dose of zinc was measured at 0, 1, 2, 3, and 4 h postdose in 16 elderly (mean age = 7.25 yr) and 12 young (mean age = 24.0 yr) subjects selected from a group of 62 healthy nonsmokers. Elderly and young subjects were divided into two groups based upon low or high detection thresholds for solutions of sodium chloride and sucrose. Mean fasting concentrations of plasma zinc were almost identical for the two age groups. Plasma response to a zinc dose was lower (p less than 0.05) in the elderly compared to that in the young, as indicated by plasma zinc levels at hours 2 and 3 postdose and by total area under the response curve. Moderate but significant age-associated increases in detection thresholds for both sodium chloride and sucrose were found; taste thresholds were not correlated to plasma uptake of the zinc dose in either age group.

Adolescent↗
PubMed1986

A demographic and social profile of age- and sex-matched vegetarians and nonvegetarians.

A demographic and social profile was compiled for 150 vegetarians and 150 nonvegetarians who were matched for age and sex. A 328-item questionnaire containing both closed- and open-ended questions was administered. Information collected included personal and demographic data, personal habits, social activities, and possible influences of vegetarianism. No differences were observed in the cultural, ethnic, or familial background of the groups. Vegetarians were less influenced by parents and traditional religions, were slightly less well educated, and were employed in less-skilled occupations. However, vegetarians socialized more than nonvegetarians, as evidenced by their greater frequency of entertaining, going out with friends, and joining organizations. The commitment to vegetarianism was strong and appeared to be reinforced by an extensive network of family and friends who were also vegetarians. This strong support network was particularly evident for those who practiced the more restrictive forms of vegetarianism, the only major difference observed within the types of vegetarians studied.

Adolescent↗
PubMed1986

Health practices, attitudes, and beliefs of vegetarians and nonvegetarians.

Health practices, attitudes, and beliefs were studied in 150 vegetarians and 150 nonvegetarians matched for age and sex. A questionnaire was administered that included a medical history and questions concerning use of medications, recreational drugs, nutrition supplements, and alcohol; smoking habits; exercise; and relaxation activities. The questionnaire also included Likert scales on which the subjects rated themselves according to their knowledge and practice of nutrition and diet and their agreement or disagreement with statements concerning health. Vegetarians believed in visiting a physician when they were ill but were more willing to try alternative or unusual therapies and/or preventive treatments. Substances that are potentially harmful to the body, such as alcohol, tobacco, or prescription drugs, were used less frequently by vegetarians. Conversely, greater use was seen of substances that are thought to improve health. The area of greatest difference between the groups was in their attitudes and beliefs concerning health. Although the vegetarians believed that they as a group were healthier than nonvegetarians, the lack of differences in self-ratings of health and incidence of health problems suggest that that perception may not be true.

Activities of Daily Living↗
PubMed1984

Effects of ascorbate on a dopaminergic response: apomorphine-induced modification of pentylenetetrazol-induced seizures in mice.

The threshold for pentylenetetrazol (PTZ)-induced clonic seizures is below control levels 15 min after administration of apomorphine (APO) but above them 60 min after APO administration. Pretreatment with ascorbic acid (10 mg/kg) or the presence of ascorbic acid in the APO solution (1 mg/ml) inhibited the early (15 min) decrease in seizure threshold caused by 60 mg/kg APO and reversed the increase in seizure threshold 60 min after a 50 mg/kg APO challenge. Ascorbate co-administration concomitant with APO also counteracted the increase in seizure threshold 60 min after 70/kg APO. Results suggest a potential model for modulation of a seizure system through dietary supplementation.

Animals↗
PubMed1983

Development and expression of autogrooming in the Mongolian gerbil, Meriones unguiculatus.

Adult gerbils, Meriones unguiculatus, autogroom their body parts in the order: mouth--nose, face, ears, flank, ventrum, and tail. This is the identical order in which the autogroom matures during the first 33 days of life. The parallel sequencing increases our understanding of neurophysiological processes underlying movement patterns and also indicates how movement patterns evolve.

Age Factors↗
PubMed1979

The role of concanavalin A dissociation on positive cooperativity of binding with native and fixed erythrocytes.

Positive cooperativity demonstrated by Scatchard plot analysis of concanavalin A (con A) binding was found with native or glutaraldehyde-fixed erythrocytes. This suggests that factors other than membrane changes might be involved in the apparent increase in receptor binding affinity with increasing site occupancy. The elution pattern of 125I-con A chromatographed on Bio-Gel P-150 with decreasing concentration showed a drop in average molecular weight compatible with con A dissociation to dimers, protomers, and protomer fragments. Similarly, the per cent of 125I-con A specifically binding to Sephadex G-75 fell with decreasing concentration of con A applied. The inclusion of unlabeled carrier con A suppressed the dissociation of labeled con A in Bio-Gel P-150 and increased the per cent binding to Sephadex G-75. Both labeled and unlabeled con A were multibanded in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. As previously reported, the three major bands are consistent with intact protomer (approximately 25,000 daltons) and two fragments (approximately 13,000 and 10,000 daltons) with minor bands representing undissociated species. These observations indicate that there is a concentration-dependent association of Con A subunits which contribute to the observed positive cooperativity of con A binding to erythrocytes.

Binding Sites↗
PubMed1974

Respiratory intensive care: a 10-year survey.

The work of the respiratory intensive care unit at the Glasgow Royal Infirmary covering a period of 10 years and involving more than 2,000 patients has been analysed. The rate of admission of patients with acute respiratory or metabolic disturbances remained surprisingly constant over the years, allowing for the increase in available beds after 1965. A disturbing feature was the notable increase in the incidence of severe self-poisonings. The continued importance of infection as a life-threatening complication is also emphasized. The reduction in mortality observed in some of the most gravely ill patients appears to justify this approach to patient care.

Adolescent↗