Search PubMed⌕ Search

Biomedical subjects

K R Jones

Publications and source records attributed to K R Jones.

At least 145 records · Page 8Linked to original sources
PubMed1981

Effect of cyproterone acetate on rate of hair growth in hirsute females.

We determined by trichometry the rate of hair growth in ten hirsute patients receiving a combination of cyproterone acetate (CA) 50 mg/daily and 'Diane' (CA 2 mg + ethinyl oestradiol 0.05 mg). In two patients there was a prompt and persistent reduction in hair growth; in three the response was less marked, and in the remaining five patients the rate of hair growth fluctuated during therapy. However, there was an overall reduction in hair growth in all but one patient during the 12 months of treatment and all patients noticed that their hair became softer, thinner and lighter in colour.

Androgen Antagonists↗
PubMed1981

Transformation of Streptococcus sanguis with monomeric pVA736 plasmid deoxyribonucleic acid.

Monomeric and oligomeric forms of a 5.0 x 10(6)-dalton plasmid (conferring erythromycin resistance) were able to genetically transform naturally competent Streptococcus sanguis. Transformation with electrophoretically purified monomer was a second-order process, whereas transformation with a dye-buoyant density gradient-purified plasmid preparation followed one-hit kinetics.

Centrifugation, Density Gradient↗
PubMed1980

Simple method for demonstrating small plasmid deoxyribonucleic acid molecules in oral streptococci.

A simple procedure for rapidly demonstrating small plasmids (less than 10 megadaltons) in oral streptococci is described. Logarithmic-phase, glycine-treated cells from 1.5-ml broth cultures were converted to osmotically fragile forms and lysed with sodium dodecyl sulfate. After the hydrodynamic shearing of host chromosomal deoxyribonucleic acid, such lysates were analyzed by low-voltage agarose gel electrophoresis. Small plasmids, migrating significantly faster than chromosomal deoxyribonucleic acid under such conditions, were readily visualized by ethidium bromide staining.

DNA, Bacterial↗
PubMed1980

Genetic transformation of Streptococcus sanguis (Challis) with cryptic plasmids from Streptococcus ferus.

By using the basic methodology initially published by Kretschmer et al. (J. Bacteriol. 124:225-231, 1975), we have been able to introduce phenotypically cryptic plasmids from Streptococcus ferus (formerly Streptococcus mutans subsp. ferus) into Streptococcus sanguis by genetic transformation. In this system, the entry of the cryptic plasmids is selected indirectly. This is effected with transforming deoxyribonucleic acid mixtures in which the cryptic plasmid deoxyribonucleic acid is present in an approximate 10-fold molar excess with respect to a plasmid (pVA1) known to confer erythromycin resistance. Under such conditions, 5 to 10% of the pVA1-containing erythromycin-resistant transformants were cotransformed with cryptic plasmid deoxyribonucleic acid. pVA1 may be selectively eliminated by growth of its S. sanguis host strain at 42 degrees C, enabling the construction of isogenic strains with and without S. ferus cryptic plasmids. Comparative physiological studies of such strains have failed to reveal any plasmid-conferred phenotypes in S. sanguis. With this procedure, we have been able to physically separate two small cryptic plasmids (2.4 x 10(6) and 2.8 x 10(6) daltons) of S. ferus. Although these plasmids were found naturally to exist in a single S. ferus host, they were able to replicate independently of one another in S. sanguis. Restriction enzyme fingerprinting indicated that these plasmids did not share a common ancestry.

Bacteriocins↗
PubMed1980

Chimeric streptococcal plasmids and their use as molecular cloning vehicles in Streptococcus sanguis (Challis).

Chimeric plasmids, which were useful as cloning vehicles in a Streptococcus sanguis (Challis) host vector system, have been constructed. By using three different strategies of restriction endonuclease digestion and ligation, a deoxyribonucleic acid (DNA) fragment bearing an erythromycin resistance determinant was ligated in vitro to a phenotypially cryptic plasmid from Streptococcus ferus. Recombinant plasmids could be recovered after transformation of S. sanguis (Challis) with these preparations. Three useful chimeras were constructed. pVA680, 5.5 megadaltons in size, contained a single KpnI site into which passenger DNA may be spliced. pVA736, 5.0 megadaltons in size, contained single EcoRI, HindIII, and KpnI sites into which passenger DNA may be spliced. The EcoRI and KpnI sites of pVA736 may be used in combination with one another when ligating DNA into this plasmid. pVA738, 3.7 megadaltons in size, contained single HindIII and AvaI sites into which passenger DNA may be spliced. pVA680, pVA736, and pVA738 were stably maintained as multicopy plasmids in S. sanguis (Challis). None of them continued to replicate (amplify) in chloramphenicol-treated cells. By using pVA736 as a vector, we have cloned a chloramphenicol resistance determinant obtained from a large, conjugative streptococcal R plasmid. In addition, chromosomal DNA sequences from Streptococcus mutans have been inserted into pVA736 by using the KpnI-EcoRI site combination.

Chloramphenicol↗
PubMed1979

Impact of alcohol, drug abuse and mental health treatment on medical care utilization. A review of the research literature.

This monograph reviews and assesses twenty-five studies that examined the question of whether treatment for mental illness, alcohol abuse or drug abuse reduces subsequent medical care utilization. In general, the studies found that such a reduction did take place. Twelve of thirteen studies found reductions of 5 to 85 per cent in medical care utilization subsequent to a mental health intervention. The median reduction was 20 per cent. The thirteenth study found that mental health services provided in a new neighborhood health center in a medically underserved neighborhood were followed by a 72 per cent increase in medical care encounters. The remaining twelve studies found reductions of 26 to 69 per cent in either medical care utilization or surrogate measures of such utilization subsequent to treatment for alcohol abuse. The median reduction was 40 per cent. The drug abuse literature in this area is sparse and primarily indirect. Although many of the studies suggested that alcohol, drug abuse or mental health (ADM) treatment was a cause of the subsequent reduction in medical care utilization, such causality was not definitively established, due to frequent methodological limitations, such as inadequate comparison groups, short time spans, small samples and lack of trend analysis. In addition, the studies focused primarily on outpatient psychotherapy in organized health care settings, particularly health maintenance organizations (HMOs), and on alcoholism treatment provided through employee-based programs and HMOs. Only very limited policy implications on such topics as health insurance and the linkage of health and ADM services can be drawn from the current body of literature. There is a need for additional research that is broader and more rigorous. To encourage such research, methodological recommendations for future studies are presented.

Alcoholism↗
PubMedDate not supplied

Organ volume determination by CT scanning: reduction of respiration-induced errors by feedback monitoring.

Computed tomography potentially provides an accurate means of determining organ volume, by summation of serial section areas. Variation in level of held respiration for each serial scan, however, severely limits accuracy in the thorax and upper abdomen. A simple strain gauge has been used to provide the patient with visual indication of the level of held respiration, so that biofeedback regulation may be achieved. Change in liver area between nominally identical pairs of images, with and without biofeedback regulation, has been used as an indicator of section reproducibility. Significant improvement in reproducibility was seen for all pairs of images where biofeedback regulation was used, compared with those pairs with conventional breath-holding. Biofeedback regulation has many applications in imaging the thorax and upper abdomen.

Adult↗
PubMedDate not supplied

Reactive airway disease in patients with prolonged exposure to industrial solvents.

This study examines the effects of volatile organic compounds (VOCs) at the workplace on pulmonary function tests. Forty-two patients with a history of industrial exposure to organic solvents and pulmonary symptomatology were studied. Lung function tests were determined utilizing screening spirometry lung volumes, diffusion capacity and methacholine stimulation test. While only 10-15% of the symptomatic patients had abnormal screening spirometry, 42% of the patients had significantly abnormal methacholine stimulation tests. These data show that exposure to volatile organic solvents is associated with bronchial hyperreactivity not commonly detected by screening spirometry and requires methacholine stimulation testing in individuals with unexplained symptomatology and history of exposure to industrial solvents. These findings indicate that the incidence of bronchial hyperreactivity is underestimated in patients with (1) verifiable exposure history to volatile organic compounds known to be pulmonary irritants, (2) pulmonary symptomatology with normal screening spirometry.

Adult↗
PubMedDate not supplied

Usefulness of patient symptoms and nasal endoscopy in the diagnosis of chronic sinusitis.

The diagnosis of chronic sinusitis can be difficult due to the variety and lack of specificity of presenting symptoms. Sinus CT scanning is presently considered the most sensitive and specific diagnostic method, but is expensive. In order to determine whether a combination of patient symptoms and nasal endoscopy could be used to predict which patients would have CT evidence of chronic sinusitis, we conducted a prospective study in which 92 consecutive patients referred for chronic sinusitis were required to fill out a questionnaire detailing their symptoms. Their responses were then correlated with subsequent findings on nasal endoscopy and CT scanning. Briefly, we found that patients with headache or facial pain as their chief complaint were less likely to have evidence of sinusitis than patients whose chief complaint was nasal obstruction or postnasal drip. Also, nasal endoscopy was shown to be moderately sensitive and highly specific in predicting results of CT scanning.

Chronic Disease↗
PubMedDate not supplied

Evaluation of the multifunctional worker role: a stakeholder analysis.

Health care organizations are rethinking how care is delivered because of incentives generated by managed care and a competitive marketplace. An evaluation of a work redesign project that involved the creation of redesigned unlicensed caregiver roles is described. The effect of model implementation on patients, multiple categories of caregivers, and physicians was measured using several different approaches to data collection. In this evaluation, caregivers perceived the institutional culture to be both market-driven and hierarchical. The work redesign, along with significant changes in unit configuration and leadership over the same period, significantly reduced job security and satisfaction with supervision. Quality indicators suggested short-term declines in quality during model implementation with higher levels of quality after implementation issues were resolved. Objective measurement of the outcomes of work redesign initiatives is imperative to assure appropriate adjustments and responses to caregiver concerns.

Attitude of Health Personnel↗
PubMedDate not supplied

Maintaining quality in a changing environment.

The turbulent health care environment has led to an increasing interest in assessment of quality of care, with a primary focus being outcomes analysis. The emphasis on organizational and clinical outcomes demands a total commitment to quality improvement and restructuring of the hospital environment.

Costs and Cost Analysis↗
PubMedDate not supplied

Evolution of the prospective payment system: implications for nursing.

Many changes have occurred in the financing and organization of health care services in recent years. Medicare's prospective payment system, a major financing innovation implemented by the federal government, is continuing to evolve in response to demands that costs be controlled while quality of care and access are ensured.

Delivery of Health Care↗