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Biomedical subjects

R B Jones

Publications and source records attributed to R B Jones.

At least 19 recordsLinked to original sources
PubMed1992

A controlled trial of a single dose of azithromycin for the treatment of chlamydial urethritis and cervicitis. The Azithromycin for Chlamydial Infections Study Group.

BACKGROUND: Currently, there is no single-dose therapy that is effective in the treatment of urethral or endocervical infections with Chlamydia trachomatis. Azithromycin is a new azalide antibiotic that has substantial activity against C. trachomatis, is concentrated intracellularly, and has a long half-life in serum and tissue. METHODS: We conducted a trial in which 299 female patients and 158 male patients with uncomplicated genital infection and a positive C. trachomatis antigen test were randomly assigned to receive either azithromycin (1 g once orally) or doxycycline (100 mg orally twice daily for seven days). Only patients subsequently determined to have a culture positive for C. trachomatis at base line were included in the evaluation of efficacy. RESULTS: Among the patients who could be evaluated, 5 of the 141 patients (4 percent) treated with azithromycin did not respond to treatment, as compared with 3 of the 125 patients (2 percent) treated with doxycycline (difference between groups, 2 percent; 95 percent confidence interval, 0 to 6 percent). Of the patients evaluated 21 to 35 days after treatment, none of 112 treated with azithromycin and 1 of 102 treated with doxycycline had a positive culture. The rates of bacteriologic cure were similar for the 98 female patients (97 percent) and the 43 male patients (95 percent) treated with azithromycin. Seventeen percent of the patients who received azithromycin and 20 percent of those treated with doxycycline had mild-to-moderate drug-related side effects, mainly gastrointestinal symptoms. CONCLUSIONS: A single 1-g dose of azithromycin is as effective for the treatment of uncomplicated genital chlamydial infections as a standard seven-day course of doxycycline.

Adolescent↗
PubMed1992

Effect of flosequinan upon isoenzymes of phosphodiesterase from guinea-pig cardiac and vascular smooth muscle.

The effect of flosequinan and its sulphone metabolite BTS 53,554, on phosphodiesterase isoenzymes isolated from guinea-pig cardiac and vascular smooth muscle using DEAE-cellulose chromatography was investigated. Zaprinast and milrinone showed peak I and peak III selectivity, and IBMX non-selective activity respectively, against both cardiac and vascular smooth muscle isoenzymes, as expected for these reference inhibitors. Flosequinan and BTS 53,554 demonstrated non-selective inhibition with similar potency against both cardiac and vascular smooth muscle isoenzymes and, overall, were the least potent compounds tested. The high inhibitory concentrations observed (IC50 peak III 660 microM for cardiac tissue and 230 microM for vascular smooth muscle with flosequinan) relative to its clinically effective plasma concentration (10 microM) questions the relevance of phosphodiesterase inhibition to the efficacy of flosequinan in heart failure.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1992

Fear and distress in Japanese quail chicks of two lines genetically selected for low or high adrenocortical response to immobilization stress.

Behavioral and adrenocortical reactivity to stressful stimulation was examined in 12- and 13-day-old chicks of two lines of Japanese quail selected over several generations for exaggerated (HS: high stress) or reduced (LS: low stress) plasma corticosterone (B) response to brief immobilization stress. Plasma B concentrations and tonic immobility (TI) fear reactions were measured in unstressed (control) and stressed (overnight cooping) chicks of both lines. The stress treatment was applied over a period of 12-20 hr and it involved capture by the experimenter, inescapable exposure to an unfamiliar environment and to strange conspecifics, reductions in ambient temperature and floor space, and the deprivation of food and water. Chicks of the HS line were more susceptible to the induction of TI and they remained immobile longer than did LS chicks. Therefore HS chicks were considered to be more fearful than their LS counterparts. Stress treatment elicited a marked adrenocortical response that was more pronounced in HS than in LS chicks. Stress treatment also increased susceptibility to TI but did not significantly affect the duration of immobility. These findings suggest that selecting the quail for differential corticosterone response to a particular stressor had exerted an unconscious and concomitant effect on underlying fearfulness as well as on their adrenocortical reactivity to several other stressful situations. The results are further discussed in terms of a putative relationship between adrenocortical activation and fearfulness.

Adrenal Cortex↗
PubMed1992

Factors associated with condom use among sexually active female adolescents.

A health belief model of condom use was used to identify factors associated with condom use in 390 sexually active female adolescents, aged 12 through 19 years, recruited at the time of a visit for reproductive health care. Fifty-six percent were white and the remainder black. Nineteen percent had genitourinary infections with Chlamydia trachomatis. Forty-six percent reported having had more than one sexual partner in the preceding year. Reported condom use for at least one specific reason (prevention of pregnancy, sexually transmitted disease, or acquired immunodeficiency syndrome) increased as behavioral, emotional, and sexually transmitted disease risk decreased, and as cognitive maturity and positive condom attitudes increased. Although uses of condoms to prevent pregnancy, sexually transmitted disease, and acquired immunodeficiency syndrome were positively intercorrelated, each made a contribution to explaining condom use at most recent coitus (odds ratios 2.95, 3.96, and 2.81, respectively). After statistical adjustment for the reported reasons for previous condom use, behavioral risk was the only additional factor associated with condom use at the most recent sexual encounter; women who participated in more risk behaviors (substance and alcohol use and minor delinquency) were less likely to have used a condom (odds ratio 0.61). Knowledge about sexually transmitted disease and acquired immunodeficiency syndrome, and concurrent use of contraceptive pills, were not related to condom practices. The data suggest that adolescents' perceptions about condoms, including the individual functions of condoms for contraception and for prevention of sexually transmitted disease, may be important in determining their use. Engaging in unprotected intercourse may be part of a larger behavioral domain that includes other unhealthy behaviors.

Adolescent↗
PubMed1992

Recurrent genitourinary chlamydial infections in sexually active female adolescents.

To determine the recurrence rate of chlamydial infections, we initially screened an urban population of 1308 sexually active female adolescents for chlamydial infection at the urethral and endocervical sites; these young women were followed and had additional examinations for infection. Chlamydial infection was documented by tissue culture in 31.1% (407) of them at some time during the study. After appropriate antibiotic treatment, 68.3% (278/407) returned for test-of-cure cultures within 3 months of their initial infection; of those 278, a total of 254 had sterile cultures. These patients were followed to determine the recurrence rate of chlamydial infections. Of these 254 patients, 177 (69.7%) had one or more follow-up visits; 38.4% (68/177) had a recurrent chlamydial infection. The majority of recurrent infections were documented within 9 months of the initial infection. Recurrent infections with the same serovar were frequent, suggesting reinfection by untreated partners or possible relapse of the initial chlamydial infection. This high rate of recurrent infection suggests that female adolescents should be rescreened frequently for genitourinary chlamydial infections.

Adolescent↗
PubMed1992

Trends in mortality from stroke in Scotland, 1950-1986.

The Scottish Registrar General's Annual Reports have been used to study trends in mortality from stroke in Scotland during 1950-1986 in those aged 45 to 74. In 1950 the age-adjusted mortality rate was 347.4 per 100,000 population for men and 360.8 for women, falling to 199.6 for men and 155.8 for women in 1986. This downward trend has increased from 1976 for males. The average annual decline in age-adjusted mortality from stroke over the 37-year period was 4.0 per 100,000 in males and 5.5 in females. This reduction in death rates was proportionally higher for women compared with men in all age groups over 55 years. As with cardiovascular deaths, mortality from stroke was lower in the east than in the central region and west of Scotland. The reduction in mortality resulted in a substantial 'saving' of lives, estimated at 12,500 between 1980 and 1984.

Age Factors↗
PubMed1992

Purging of autologous bone marrow for transplantation: the protection and selection of the hematopoietic progenitor cell.

Autologous bone marrow transplantation (ABMT) is the treatment of choice for selected patients with acute myelogenous leukemia, non-Hodgkin's lymphoma, and poor prognosis breast cancer. A possible limitation of this approach is that clonogenic tumor cells could be collected and infused back into the patient along with the normal bone marrow. The major emphasis in our laboratory has been the development of marrow purging regimens for breast cancer patients. This paper describes two investigative approaches hematopoietic progenitor cell protection and selection. We describe how the use of G-CSF in the patients who receive positively selected marrow shortens the rate of engraftment.

Bone Marrow Purging↗
PubMed1992

The quality and relevance of peripheral neuropathy data on a diabetic clinical information system.

Routinely collected peripheral neuropathy data entered on a diabetic clinical information system since 1979 have been audited for completeness, consistency, accuracy (inter-observer variation), validity by comparison with biothesiometry, and relevance by life table analysis for foot ulceration. Peripheral neuropathy was defined by a neuropathy disability score > or = 4. The data were 98% complete. Forty-nine of 3405 (1.4%) had inconsistent records. Agreement between observers for clinical examination was significant (p < 0.05) for aggregate neuropathy score and its individual components except the knee jerk: Kappa score for observer variation for neuropathy score 0.56 (95% confidence interval 0.36-0.76). There was good agreement between neuropathy defined as aggregate score > or = 4, and as combined vibration perception thresholds for both feet > 60 V: Kappa statistic 0.62 (95% confidence interval 0.44-0.80). The chance of developing a foot problem in 3 years increased from 3% for patients with a score of zero to 45% for people with a score of between 9 and 12. We conclude that the calculation of a clinical neuropathy score is a simple, valid and relevant method for diabetes care both in hospital and the community. When combined with palpation of peripheral pulses most patients at risk of foot ulceration can be identified allowing targeting of preventive chiropody and orthotic resources.

Diabetic Neuropathies↗
PubMed1992

Oral health and oral health behaviour in a population of diabetic outpatient clinic attenders.

The control of oral health in individuals suffering from diabetes mellitus may affect a diabetic individual's insulin requirements. This study examined the oral health status and behaviours of a group of diabetic patients and compared the results to those obtained in a recent UK national survey of oral health. The results showed that, despite reporting higher levels of oral self-care, the diabetic population suffered from higher rates of caries than "normal" individuals. These differences could not be accounted for by the treatment received from dentists. It is concluded that diabetic patients are more caries prone than the general population and that the cause of this difference should be sought, as the traditional aetiological agent for caries cannot account for the increased caries rate. If the aetiology of the findings of this study were determined, progress could be made in the search for indicators of increased caries risk.

Adolescent↗
PubMed1992

Comparison of immunotyping of Chlamydia trachomatis by indirect fluorescent-antibody staining and radioimmunoassay.

Chlamydia trachomatis isolates from 58 patients were immunotyped by radioimmunoassay (RIA) and fluorescent-antibody staining (FA) by using monoclonal antibodies. Unambiguous typing was observed with 55 isolates by FA and 53 isolates by RIA, although 3 isolates were typed by RIA but not FA. FA required less antigen and was more sensitive in detecting mixed infections.

Antibodies, Monoclonal↗
PubMed1992

Research note: open-field behavior of Japanese quail chicks genetically selected for low or high plasma corticosterone response to immobilization stress.

Open-field behavior was examined in Japanese quail chicks genetically selected for either reduced (LS, low stress) or exaggerated (HS, high stress) plasma corticosterone response to immobilization stress. Chicks of the LS line showed less freezing and ambulated sooner than did their HS counterparts. These findings suggest that exposure to an open-field or novel environment elicited less fear in LS than in HS chicks. They also support the suggestion that fearfulness and adrenocortical activation are positively associated and indicate that selection for differential adrenocortical responsiveness exerted concomitant effects on fear-related behavior.

Animals↗