Search PubMed⌕ Search

Biomedical subjects

M Williams

Publications and source records attributed to M Williams.

At least 667 records · Page 37Linked to original sources
PubMed1982

Effects of estradiol-17 alpha on nuclear occupancy of the estrogen receptor, stimulation of nuclear type II sites and uterine growth.

Estriol and estradiol-17 alpha (E2-17 alpha) have classically been described as weak or impeded estrogens since they are incapable of stimulating true uterine growth when administered acutely by single injection. We have demonstrated [16] that estriol is capable of stimulating true uterine growth when the hormone is administered by paraffin implant. The possibility that E2-17 alpha is similar to estriol was examined. A single injection of E2-17 alpha causes a rapid accumulation of the estrogen receptor in uterine nuclei and this is correlated with the stimulation of early uterotropic responses. The nuclear receptor content declines rapidly and no stimulation of nuclear type II sites or true uterine growth is observed. E2-17 alpha does however stimulate the replenishment of cytoplasmic estrogen receptor. This receptor-response profile is typical of a short acting estrogen such as estriol. Chronic exposure (96 h) of mature-ovariectomized rats to estradiol-17 alpha (4 mg) by beeswax implant results in continual nuclear occupancy by estrogen receptors, dramatic stimulation of nuclear type II sites and true uterine growth. It is not possible to determine whether the uterotropic stimulation was due to direct effects of E2-17 alpha since this isomer was partially metabolized to E2-17 beta and both isomers were found in uterine nuclei after an implant of E2-17 alpha. We conclude that E2-17 alpha is capable of acting as an estrogen, either by its inherent estrogenicity or by its conversion to E2-17 beta, and that it may be dangerous to consider this steroid to be an ineffective or inadequate estrogen.

Animals↗
PubMed1982

Unusual vascular findings in transplanted kidneys.

Of 189 unsuccessful renal transplant cases, eight were selected for retrospective analysis because they had been classified histologically as "chronic rejection with marked vascular changes" even though they had been removed less than 60 days after transplantation. Review of these cases revealed that only one of the eight transplants had postoperative function and that this transplant had only marginal functions. All eight kidneys had intimal damage that was unlike the usual lesions of rejection. Five kidneys showed evidence of thrombosis with recanalization, and five had what appeared to be a double layer of the intima. The findings in eight cases suggest that severe intimal damage occurred within 60 days of implantation and may not represent the usual rejection processes; it may reflect, in part, damage to the intima prior to or during implantation.

Adult↗
PubMed1982

Aminomethyl-1,2,4-benzothiadiazines as potential analogues of gamma-aminobutyric acid. Unexpected discovery of a taurine antagonist.

A series of 6- and 8-(aminomethyl)-4H-1,2,4-benzothiadiazine 1,1-dioxides has been synthesized and tested for interaction with various GABA systems. None of the compounds showed significant GABA-mimetic properties, but unexpectedly, compound 7 [6-(aminomethyl)-3-methyl-4H-1,2,4-benzothiadiazine 1,1-dioxide] possessed the properties of a selective antagonist of taurine, as measured by the antagonism of taurine-induced inhibition of rat cerebellar Purkinje firing.

4-Aminobutyrate Transaminase↗
PubMed1982

Use of (S)-(trifloxymethyl)oxirane in the synthesis of a chiral beta-adrenoceptor antagonist, (R)- and (S)-9-[[3-(tert-butylamino)-2-hydroxypropyl]oximino]fluorene.

Two synthetic approaches were used to prepare, in chirally pure form, the beta-adrenoceptor antagonist 9-[[3-(tert-butylamino)-2-hydroxypropyl]oximino]fluorene (1a). One of these employed the oxazolidine (S)-6 generated from D-mannitol, while the other utilized (S)-[[(trifluoromethanesulfonyl)oxy]methyl]oxirane (4) as the chiral three-carbon fragment. This latter synthesis was designed to incorporate the amino function in the last step. In vitro, a beta 2 selectivity of only 2.2 was observed for 1a. The example, (S)-9-[[3-(tert-amylamino)-2-hydroxypropyl]oximino]fluorene (1b), was also prepared and found to be selective for the beta 1 receptor by a factor of 2.5. In contrast to other beta-adrenoceptor antagonists, the enantiomers of 1a exhibited no chiral preference; i.e., (S)-1a and (R)-1a possessed a similar order of beta-adrenoceptor antagonistic activity.

Adrenergic beta-Antagonists↗
PubMed1982

Third report of the ASCP/CAP/APC joint task force on pathology manpower.

This report concerns the results of pathology manpower surveys encompassing responses from four groups of pathologists: (1) solo and group practitioners; (2) training program directors; (3) house staff; (4) diplomates seeking positions. The rate of response by all four groups is judged highly satisfactory. The results show an approximate balance between supply and demand with respect to manpower in pathology. Comparison with the results of two similar surveys conducted by the Joint Task Force shows the following trends: (1) a continued marked reduction of foreign medical graduate (FMG) trainees; (2) continued increase in the proportion of women entering pathology; (3) an increase in the size of the average practice and a corresponding decrease in the proportion of pathologists in solo practice; (4) a decreased tendency of practicing pathologists to relocate; (5) an increase in pathologists lost to the profession because of death, disability and retirement; (6) a slight decrease (approximately 50) in the number of funded full-time positions and a slight increase in the number of part-time vacancies.

Aged↗
PubMed1982

Bacteriuria in patients undergoing prostatectomy.

A review of the literature revealed that the reported incidence of bacteriuria arising before and after prostatectomy varied considerably, that there had been little investigation of the organisms isolated, and that the value of chemoprophylaxis at the time of prostatectomy was unproven. Using standard criteria and technical procedures, 248 patients undergoing prostatectomy were studied over a two-and-a-half-year period. Preoperative bacteriuria occurred in 28% of patients. The incidence was significantly increased in patients catheterised before operation (44%) compared with those who had not been catheterised (18%). The incidence of bacteriuria was directly related to the duration of catheter drainage. Postoperatively, 40% of patients with sterile urine at the time of prostatectomy developed bacteriuria. There was an increased prevalence of Enterococcus and coagulase-negative Staphylococcus isolates from postprostatectomy bacteriuria compared with preprostatectomy bacteriuria. Based on this information, suggestions can be made regarding the choice of a suitable chemoprophylactic agent and the optimum timing and duration of its administration.

Anti-Bacterial Agents↗
PubMed1982

Interaction of the benzodiazepine antagonists, CGS 8216 and Ro 15-1788, with central adenosine A-1 receptors.

Although the potent benzodiazepine antagonist CGS 8216 has in vitro activity indicative of an interaction with central adenosine systems, neither it, nor the benzodiazepine antagonist Ro 15-1788 showed any great degree of interaction with central adenosine A-1 receptors as measured by radioligand binding. It is concluded that interaction of benzodiazepine antagonists with A-1 receptors is not a property related to their antagonist activity.

Adenosine↗
PubMed1982

Effectiveness of ivermectin in the treatment of equine Parascaris equorum and Oxyuris equi infections.

Fifteen horses harboring naturally acquired, patent Parascaris equorum and Oxyuris equi infections were equally allotted to 3 treatment groups given (1) injectable vehicle; (2) injectable ivermectin at the dose rate of 200 microgram/kg of body weight; and (3) injectable ivermectin at the rate of 300 microgram/kg. All treatments were given IM in the neck. All animals were killed 14 days after treatment and examined for the targeted nematodes. Regardless of dose rate, ivermectin proved 100% effective in the removal of adult O equi and P equorum infections. Levels of immature P equorum were decreased by 98.5% in both ivermectin-treated groups. Oxyuris equi 4th-stage larval injections were decreased by 95.7% and 99.9% by the 200 and 300 microgram/kg ivermectin treatments, respectively. Adverse reactions to the injections of drug were not seen.

Animals↗