Search PubMed⌕ Search

Biomedical subjects

H E Jones

Publications and source records attributed to H E Jones.

At least 55 records · Page 3Linked to original sources
PubMed1997

Response of cell growth and retinoic acid receptor expression to retinoic acid in neoplastic and non-neoplastic prostate cell lines.

BACKGROUND: Retinoic acid (RA) is recognized as an inhibitor of tumorigenesis, but conversely, has also been shown to act as a tumor enhancer, therefore its role in prostate tumor cell growth was investigated. METHODS: The response of two human prostate tumor cell lines (PC-3 and DU-145), and cell lines derived from a well-differentiated canine prostate adenocarcinoma (CPA) and normal canine prostate epithelium (CAPE) to all-trans RA was determined using growth curve analysis. Additionally, the constitutive expression and RA-challenged expression of retinoic acid receptors (RARs) -alpha, -beta, and -gamma mRNA was examined using Northern blotting techniques. RESULTS: In response to all-trans RA, the PC-3 and DU-145 cell lines showed considerable growth promotion, while CAPE and CPA cell growth was dramatically inhibited. Each cell line expressed RAR alpha and RAR gamma, with either negligible or no RAR beta transcripts being detected. RAR alpha and -gamma mRNAs detected in the four cell lines were variably regulated in response to RA, and no distinct patterns of RAR regulation that could be related to cell growth responses were observed. CONCLUSIONS: The data indicates that no simple association exists between the expression or regulation of RAR subtype mRNAs and the divergent growth responses to RA displayed by the prostate cell lines.

Adenocarcinoma↗
PubMed1997

Oral terbinafine in the treatment of toenail onychomycosis: North American multicenter trial.

BACKGROUND: Onychomycosis is an increasing problem with limited therapeutic options. OBJECTIVE: We evaluated the safety and efficacy, of oral terbinafine, a new fungicidal antimycotic, in patients with toenail onychomycosis. METHODS: A North American multicenter, double-blind, placebo-controlled study evaluated the mycologic and clinical efficacy of oral terbinafine 250 mg/day for 12 or 24 weeks in 358 patients with toenail onychomycosis. RESULTS: A total of 74% of patients treated with 12 or 24 weeks of terbinafine achieved a successful clinical outcome. Approximately 11% of terbinafine responders showed evidence of relapse 18 of 21 months after cessation of treatment. Terbinafine was well tolerated; most adverse events were transient and mild to moderate in severity. CONCLUSION: The results of this study confirm that oral terbinafine is a safe and effective therapy for the treatment of onychomycosis.

Abdominal Pain↗
PubMed1997

Prenatal stress alters the size of the rostral anterior commissure in rats.

In rodents and other mammals, prenatal stress disrupts both sexual differentiation and sexual behavior. The present study examined the area of the anterior division of the anterior commissure (the Aca) in coronal, thionin-stained sections of prenatally stressed (P-S), and control male and female rats. Pregnant rats were exposed to thrice-daily heat, light, and restraint stress or left undisturbed during days 15-22 of pregnancy. Adult P-S and control males and females were killed, perfused, and their brains removed. Serial coronal sections (total of approximately 200 microm) through the rostral portion of the Aca (the rAca) were taken and stained with thionin. The sections were examined and traced under x25 using computerized microscopy to obtain the area in mm2. The data revealed that control females had a larger rAca compared to control males, and that P-S males had a larger rAca compared to control males; further, control males and P-S females were not significantly different, nor were control females and P-S males. These results suggest that, in rats, the Ac may be sexually dimorphic (in a direction similar to that described in humans) and that prenatal stress an event that modifies sex-typical behavior, physiology, and neuroanatomy reverses that sex difference.

Aging↗
PubMed1997

Past and present levels of some radionuclides in fish from Bikini and Enewetak Atolls.

Bikini and Enewetak were the sites in the Northern Marshall Islands that were used by the United States as testing grounds for nuclear devices between 1946 and 1958. The testing produced close-in fallout debris that was contaminated with different radionuclides and which entered the aquatic environment. The contaminated lagoon sediments became a reservoir and source term of manmade radionuclides for the resident marine organisms. This report contains a summary of all the available data on the concentrations of 137Cs, 60Co and 207Bi in flesh samples of reef and pelagic fish collected from Bikini and Enewetak Atolls between 1964 and 1995. The selection of these three radionuclides for discussion is based on the fact that these are the only radionuclides that have been routinely detected by gamma spectrometry in flesh samples from all fish for the last 20 y. Flesh from fish is an important source of food in the Marshallese diet. These radionuclides along with the transuranic radionuclides and 90Sr contribute most of the small radiological dose from ingesting marine foods. Some basic relationships among concentrations in different tissues and organs are discussed. The reef fish can be used as indicator species because their body burden is derived from feeding, over a lifetime, within a relatively small contaminated area of the lagoon. Therefore, the emphasis of this report is to use this extensive and unique concentration data base to describe the effective half lives and cycling for the radionuclides in the marine environments during the 31-y period between 1964 and 1995. The results from an analysis of the radionuclide concentrations in the flesh samples indicate the removal rates for the 3 radionuclides are significantly different. 137Cs is removed from the lagoons with an effective half life of 9-12 y. Little 60Co is mobilized to the water column so that it is depleted in both environments, primarily through radioactive decay. The properties of 207Bi are different at Enewetak and Bikini. At Enewetak the radionuclide is lost from the environment with an effective half live of 5.1 y. At Bikini only radioactive decay can account for the rate at which the radionuclide is lost from the lagoon. The difference in the binding properties of the sedimentary materials for 207Bi among the two Atolls is not understood.

Animals↗
PubMed1997

Double-blind, randomized comparison of itraconazole capsules vs. placebo in the treatment of toenail onychomycosis.

Three multicenter, randomized, double-blind, placebo-controlled studies were conducted to determine whether twelve weeks of therapy with itraconazole, 200 mg, was effective in the treatment of dermatophyte infection of the toenail. Significantly more patients treated with itraconazole (110 patients) than with placebo (104 patients) achieved clinical (65 percent vs. 3 percent) and mycologic (54 percent vs. 6 percent) success. The mean percentage of affected reference nail before the initiation of therapy was 76 percent. Adverse events were comparable in the two treatment groups. These findings demonstrate that twelve weeks of continuous itraconazole, 200 mg once daily, is a highly effective, well-tolerated therapy for the management of toenail onychomycosis.

Adolescent↗
PubMed1997

Evaluation of the reinforcing and discriminative stimulus effects of the N-methyl-D-aspartate competitive antagonist NPC 17742 in rhesus monkeys.

The phencyclidine (PCP)-like effects of the N-methyl-D-aspartate (NMDA) competitive antagonist 2R,4R,5S-2-amino-4,5-(1,2-cyclohexyl)-7-phosphonoheptanoic acid (NPC 17742) were evaluated in three behavioral tests in rhesus monkeys. The discriminative stimulus properties of NPC 17742 (2-24 mg/kg, i.m.) were tested in four rhesus monkeys trained to discriminate PCP from saline under a fixed-ratio (FR) 50 schedule of food reinforcement. In three of the monkeys, NPC 17742 showed complete substitution for PCP at doses which did not decrease rates of responding. Intravenous self-administration of NPC 17742 (50-800 micrograms/kg/infusion) was tested under a FR schedule of reinforcement in four monkeys trained to lever press for infusions of PCP. At least one dose of NPC 17742 functioned as a reinforcer in two of the monkeys. A second self-administration study, employing a 10 min fixed interval schedule of reinforcement, was performed in three monkeys trained to self-administer PCP during three daily sessions. Compared with PCP, NPC 17742 (0.4-1.6 mg/kg/infusion) maintained very low rates of responding; NPC 17742 could not be clearly established as a reinforcer in this procedure. The data show that NPC 17742 has some PCP-like behavioral effects, and may function as a weak reinforcer in some subjects under specific conditions. The results provide further evidence that both similarities and differences exist between the behavioral effects of PCP and competitive NMDA antagonists.

Amino Acids↗
PubMed1996

Developmental consequences of intermittent and continuous prenatal exposure to 1,1,1-trichloroethane in mice.

The effects of 1,1,1-trichloroethane (TCE) on physical and behavioral development were examined in CD-1 mice prenatally exposed under two regimens. In the first study, pregnant mice were exposed to either 2,000 ppm TCE or filtered air for 17 hrs. during gestational days (GD) 12-17. A third group remained untreated. The results revealed no differences on pregnancy outcome. TCE-exposed pups gained less weight, exhibited delays in developmental landmarks and acquisition of the righting reflex, had poorer performance on tests of motor coordination and exhibited delays in negative geotaxis relative to sham or untreated pups. A second experiment was designed to more closely parallel the intermittent, acute, high-concentration pattern of solvent abuse. Pregnant mice were exposed for 60 min. to 8,000 ppm TCE or sham placement in exposure chambers three times/day during GD's 12-17. The results were very similar to what were obtained in the more continuous exposure study. TCE-exposed pups gained less weight, had delays in developmental landmarks and acquisition of the righting reflex and exhibited weaker grip strength, poorer negative geotaxis and less rooting intensity in comparison to sham pups. These data provide evidence for the behavioral and developmental teratogenicity of prenatal TCE exposure late in gestation.

Animals↗
PubMed1996

Context-dependent interactions and visual processing in V1.

We examined the influence of stimulus context on the response of cells in primate V1 utilising both concentric and spatially discrete stimuli. The majority of cells (63/71) showed marked patch suppression, including non-oriented cells. This suppression was reduced or lost if there was an orientation discontinuity in the stimulus overlying the receptive field. Cross-oriented stimuli could exert strong facilitatory effects so that a cell's response to an optimally oriented stimulus over its receptive field was increased by the presence of an adjacent cross-oriented stimulus. This increase appeared to involve both disinhibition as well as a direct facilitation. The strength of the cross-orientation effects was such that for some cells it seemed appropriate to define a cross-oriented stimulus configuration as the 'optimal' stimulus. Effects following from orientation context could be strongly influenced by stimulus direction. Subcortical as well as cortical interactions may contribute to these observations. It is suggested that the properties of the network as a whole define the responses of individual cells and that the representation of discontinuities is an important component of network function in V1.

Animals↗
PubMed1996

Efficacy of feedback from quarterly laboratory comparison in maintaining quality of a hospital capillary blood glucose monitoring program.

OBJECTIVE: A 1-year randomized prospective study was conducted to investigate the efficacy of feedback from split-sample testing as part of a capillary blood glucose quality assurance program. RESEARCH DESIGN AND METHODS: A total of 124 nurses were randomized to either group A (quarterly comparisons with feedback) or group B (no feedback). The measure of nurse accuracy against the laboratory at 0, 6, and 12 months was determined by an additional five to seven split-sample tests without giving feedback to either group. Mean accuracy was determined in terms of percent absolute deviation from the laboratory result and a clinical consensus limit of +/- 20% deviation from the laboratory. RESULTS: By 12 months, there was a significant effect of feedback on nurse agreement with the laboratory method (P = 0.022 when agreement was scored as the mean percent absolute difference and P = 0.002 when agreement was scored in terms of the +/- 20% clinical consensus limit). Nurses in the group who had received no quarterly feedback from split-sample testing produced a 3.5% greater mean percent absolute deviation from the laboratory method and 12% fewer comparisons within the acceptable +/- 20% range. CONCLUSIONS: Feedback received from split-sample testing has a significant effect in maintaining accuracy in capillary blood glucose monitoring.

Blood Glucose↗