Search PubMed⌕ Search

Biomedical subjects

M Johnson

Publications and source records attributed to M Johnson.

At least 307 records · Page 17Linked to original sources
PubMed1997

Cervical abnormality and sexually transmitted disease screening in human immunodeficiency virus-positive women.

OBJECTIVE: To determine the incidence of genital tract infections and cervical abnormalities in 185 human immunodeficiency virus (HIV)-positive outpatients with a view toward establishing an effective policy for gynecology screening. METHODS: Gynecology results were reviewed for 185 HIV-positive women seen as outpatients at the Royal Free Hospital in London. All subjects underwent screening for cervical abnormalities (smear and colposcopy) and sexually transmitted disease (STD) at 6-month intervals for 6 years. The STD prevalence was calculated, and the relationship between the occurrence of STDs and the demography and sexual lifestyle of the women was examined to determine whether these factors were predictive for women at risk for STDs. The incidence of cervical intraepithelial neoplasia (CIN) was determined. We reviewed the use of colposcopy in addition to cytology as a primary screening test to see whether it improved the detection rate of CIN. RESULTS: Sixty-five (35.1%) women had a history of previous STDs, and new STDs were detected in 18 women at their first visits. None were detected at subsequent visits. Sexual lifestyle details did not predict women at risk for STDs. Ninety-eight (53%) cervical smears were reported as normal at the first visit, but there was a 3.1% (95% confidence interval 0, 6.6) false-negative rate when compared with colposcopy and directed biopsy. Five of fifty women (10%) with CIN I had progressed to higher-grade lesions by 6-month follow-up. CONCLUSIONS: Given the low prevalence of STDs detected, except for initial screening at presentation, regular, repeat STD screening of HIV-positive women appears to be unnecessary. Because of the high incidence of cervical abnormalities, screening for cervical biopsy improved the detection rate of cervical abnormalities.

Adult↗
PubMed1997

The role of emergency medical services in primary injury prevention. Consensus workshop. Arlington, Virginia, August 25-26, 1995.

Injury is a leading cause of death and disability. Preventing injuries from ever occurring is primary injury prevention (PIP). The objective of this statement is to present the consensus of a 16-member panel of leaders from the out-of-hospital emergency medical services (EMS) community on essential and desirable EMS PIP activities. Essential PIP activities for leaders and decision makers of every EMS system include: protecting individual EMS providers from injury; providing education to EMS providers in PIP fundamentals; supporting and promoting the collection and utilization of injury data; obtaining support for PIP activities; networking with other injury prevention organizations; empowering individual EMS providers to conduct PIP activities; interacting with the media to promote injury prevention; and participating in community injury prevention interventions. Essential PIP knowledge areas for EMS providers include: PIP principles; personal injury prevention and role modeling; safe emergency vehicle operation; injury risk identification; documentation of injury data; and one-on-one safety education.

Accident Prevention↗
PubMed1997

The efficacy of exit site povidone-iodine ointment in the prevention of early peritoneal dialysis-related infections.

Infections are the main complications of peritoneal dialysis, and currently there is no established method for prevention. A prospective, randomized, single-blind study was performed to evaluate the efficacy of regular application of povidone-iodine ointment at the catheter site (during the entire time on the study) in peritoneal dialysis. One hundred twenty patients were randomized; three were excluded for not completing the study. Sixty-one patients received application of povidone-iodine and 56 patients received standard care. Povidone-iodine ointment was effective in delaying infectious complications, with a lower proportion of treated patients having infections (exit site and peritonitis) within 140 days of starting dialysis compared with the controls (P = 0.04, Wilcoxon test). This protective benefit was lost after 140 days on dialysis. Staphylococcus aureus infections developed in only two (3.3%) of the treated patients compared with 10 (21.4%) of the controls (P = 0.009), despite the higher rate of S aureus nasal carriage in the treated group (22 of 61 patients [36%] v 14 of 56 patients [25%]).

Adult↗
PubMed1997

Density and composition of microorganisms during long-term (418 day) growth of potato using biologically reclaimed nutrients from inedible plant biomass.

A study evaluating alternative methods for long term operation of biomass production systems was recently completed at the Kennedy Space Center (KSC). The 418-day study evaluated repeated batch versus mixed-aged production of potato grown on either standard 1/2-strength Hoagland's nutrient solution or solutions including nutrients recycled from inedible plant material. The long term effects of closure and recycling on microbial dynamics were evaluated by monitoring the microbial communities associated with various habitats within the plant growth system (i.e., plant roots, nutrient solution, biofilms within the hydroponic systems, atmosphere, and atmospheric condensate). Plate count methods were used to enumerate and characterize microorganisms. Microscopic staining methods were used to estunate total cell densities. The primary finding was that the density and composition of microbial communities associated with controlled environmental plant growth systems are stable during long term operation. Continuous production resulted in slightly greater stability. Nutrient recycling, despite the addition of soluble organic material from the waste processing system, did not significantly increase microbial density in any of the habitats.

Air Microbiology↗
PubMed1997

Transient increases in catecholaminergic activity in medial prefrontal cortex and nucleus accumbens shell during novelty.

Voltammetric recordings with electrochemically modified carbon-fiber electrodes were obtained from specific regions of the forebrain in rats given free-choice access to a novel environment. Entry into novelty increased the catechol signal in the medial prefrontal cortex and shell of the nucleus accumbens by more than 100%, but had no consistent effect in either the neostriatum or accumbal core. In both the medial prefrontal cortex and accumbal shell, moreover, the novelty-induced increase in catecholaminergic activity was detectable only during the initial entry into the novel compartment and did not reappear when animals returned to the familiar environment. These results support increasing evidence for a functional distinction between the accumbal core and shell, with the latter having been linked to brain reward mechanisms. The results also indicate that novelty activates, albeit very transiently, some of the same neurochemical systems believed to play a critical role in the reinforcing effects of certain drugs of abuse.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1997

Using cluster analysis to develop a healing typology in vascular ulcers.

A clinically meaningful typology of healing was developed to assist nurses in assessing patients' healing potential. A descriptive correlational design was used to determine similarities in healing characteristics of older people with venous, venous-arterial, and arterial leg ulcers (n = 156). Hierarchical clustering techniques dendrogram using Ward's method suggested that three clusters existed based on the ankle/brachial pressure index, liposclerosis (hardening and induration of the skin of the lower limb), edema and wound characteristics: thus a healing typology was potentially formed. Nonhierarchical techniques such as analysis of variance examined cluster differences for the initial ulcer area (p < 0.013) and suggested that these groupings were reflective of differing ulcer areas. However, significant differences in the rate of healing (difference between ulcer surface area in week 4 and week 1) (measured by topographic mapping) group comparisons were not significant at the 0.05 level. Clinical differences in the healing rate were apparent, and three individual profiles of leg ulcer sufferers based on the three differing clusters of factors were outlined: rapid healers, slow healers, and nonhealers. Further research into the clustering of these factors and their application to longer healing times or time to complete healing may be significant and support the utility of this typology.

Aged↗
PubMed1997

The duration of action of non-beta 2-adrenoceptor mediated responses to salmeterol.

1. To investigate further the mechanism of the long duration of action of the selective beta 2-adrenoceptor agonist, salmeterol, we have determined the duration of action of some responses to salmeterol which are not mediated through beta 2-adrenoceptors. 2. In the presence of propranolol (1 microM), salmeterol (1-30 microM) caused concentration-related relaxation of superfused, pre-contracted strips of guinea-pig gastric fundus. On washing the tissues, these relaxant responses were rapidly lost, the time to 50% recovery being approximately 30 min. 3. In human neutrophils, salmeterol (1-100 microM) caused concentration-related inhibition of FMLP-induced O2- release. Propranolol (1 microM) had little or no effect on the inhibitory activity of salmeterol. Washing the cells twice over a 40 min period caused a marked reduction of the inhibitory activity of salmeterol. 4. In guinea-pig superfused trachea, in the absence of propranolol, infusions of (RS)-salmeterol (10-30 nM) and the less potent (S)-enantiomer of salmeterol (300-3000 nM) inhibited electrically-induced contractile responses. When the infusion was stopped, there was no recovery from the inhibitory responses within 200 min. In the presence of propranolol (1 microM), infusions of (RS)-salmeterol (10 microM) and (S)-salmeterol (10-100 microM) also inhibited the contractile responses, but, in contrast, on stopping the infusions differences were observed in recovery times. Thus no appreciable recovery was observed from the responses to (RS)-salmeterol, whereas a rapid loss of inhibition was observed on stopping the infusion of (S)-salmeterol, the time to 50% recovery being 30-35 min. 5. These relatively short-lasting effects of salmeterol which are not mediated through beta 2-adrenoceptors, contrast with the persistence of the responses which are mediated through beta 2-adrenoceptors seen in a variety of tissues, but are similar to the rate of dissociation of salmeterol observed from artificial membranes. These observations suggest that the sustained agonist activity of salmeterol is peculiar to responses mediated by beta 2-adrenoceptors.

Adrenergic beta-Agonists↗
PubMed1997

Acute effect of exercise and low-fat diet on energy balance in heavy men.

OBJECTIVE: To quantify the acute effect of the exercise-low-fat diet combination on energy balance compared with sedentarity and a high fat diet in overweight individuals. DESIGN AND MEASUREMENTS: We assessed the acute effect of exercise and ad libitum intake of low-fat foods on daily energy balance. Six heavy men participated in two randomly assigned sessions which required a 24 h stay in a whole body indirect calorimeter. Sessions were preceded by either a 60 min aerobic exercise at 50% VO2 max or a 60 min rest. Subjects were fed a low-fat diet (mean FO = 0.89) after exercise and a mixed diet (mean FQ = 0.85) after the resting period. RESULTS: The difference in energy balance between the two conditions was 7.3 MJ. About half of the effect was attributable to the energy surplus expended during exercise whereas the remaining fraction was explained by the difference in post-exercise energy balance. CONCLUSION: In heavy men, the combination of a low-fat diet and exercise has a strong acute effect on energy balance compared to a rest-mixed diet condition.

Adult↗
PubMed1997

Observations on the neglected concept of intervention in nursing research.

In this paper I will examine the concept of researcher intervention in nursing research. I will suggest that the concept is essentially problematic for both positivist and qualitative researchers, which may have some bearing upon its relative neglect as an area for discussion. I will examine the redundancy of the more popular moral frameworks in dealing with the problems raised by intervention and suggest that nursing research, being 'messy', requires the articulation of a more reflexive and contextual approach. This applies both to moral justification and to more pragmatic methodological issues. In the paper I suggest that humanistic action research, informed by recent feminist thinking, has potential to produce a more creative and clinically relevant future for nursing research than is currently so.

Confounding Factors, Epidemiologic↗
PubMed1997

Effect of pretreatment of germanium-132 on Na(+)-K(+)-ATPase and galactose cataracts.

PURPOSE: Recently, we reported that topical administration of 2-carboxyethyl germanium sesquioxide (Ge-132) concurrently with 50% galactose feeding delayed the establishment of mature cataracts and reduced advance glycation product. This study was to determine the effect of pretreatment of Ge-132 on galactose associated morphological changes and Na(+)-K(+)-ATPase activity. METHODS: Young Sprague Dawley rats received topical eye drops four times a day of either saline or Ge-132 seven days prior to the 50% galactose diet and during galactose feeding. At desired intervals the lenses were extracted, photographed and processed for either light microscopy, scanning electron microscopy or the determination of Na(+)-K(+)-ATPase activity. RESULTS: In Ge-132 pretreated lenses as compared to saline pretreated lenses the following results were observed: (a) the galactose-induced morphological alterations in the majority of lenses were delayed and (b) Na(+)-K(+)-ATPase activity was protected. CONCLUSIONS: Our previous and current studies show that in addition to osmotic stress post-translational protein modification, such as glycation, including enzymes may play a role in initiating changes that lead to cataract development. The inhibition of protein glycation by antiglycating compounds, such as Ge-132, delays sugar cataract formation. Currently, we are investigating the status of protein glycation and advanced glycation end products following pretreatment with Ge-132 and the role of Ge-132 on the activities of enzymes such as aldose reductase and Na(+)-K(+)-ATPase.

Animals↗
PubMed1997

Access to medical care one year prior to diagnosis in 100 HIV-positive women.

BACKGROUND: Anonymous antenatal testing for HIV antibodies suggests that the majority of HIV-positive women in the UK remain undiagnosed. Primary care reaches the majority of the population and women present more often than men. Sexual health matters are frequently raised, so there is an opportunity to discuss concerns with respect to HIV. Women often present with advanced HIV disease and with antiviral treatments proving to be more effective, there is now an even greater incentive to diagnose HIV early. OBJECTIVE: We aimed to look at access to medical care 1 year prior to HIV diagnosis in 100 HIV-positive women and to establish whether a discussion regarding HIV was recalled. METHOD: The setting was an established clinic for HIV-positive women in the Royal Free Hospital, London. In a 6-month period a questionnaire was completed by 100 women with their clinic doctor. RESULTS: Women were young (mean age 31). Most (84%) were infected by heterosexual sex. Forty-six per cent of the women presented with symptomatic HIV or AIDS and 50% were black Africans, hence there is a large ethnic bias in this sample. General practice was accessed by 65% of the women 1 year prior to HIV diagnosis. Few (14%) women recalled a discussion concerning HIV. Secondary care settings such as gynaecology and general outpatients were also frequently attended, but again HIV was apparently rarely discussed. There was no significant difference when variables such as time since diagnosis, health care setting, or ethnic group were concerned with respect to recall of a discussion concerning HIV. CONCLUSIONS: Despite coming from 'high risk' groups or presenting with symptomatic disease in the year prior to HIV diagnosis, few women recalled discussing HIV in either primary or secondary care settings. As these sites were commonly accessed, we feel that doctors and other health care workers should be encouraged and trained to raise HIV more routinely in their consultations.

Adult↗
PubMed1997

Three medical schools' responses to the HIV/AIDS epidemic and the effect on students' knowledge and attitudes.

PURPOSE: To assess the relative importance of factors influentail by the prevalence of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), such as didactic and clinical training, and the number of HIV-infected individuals known personally, on students' HIV-related knowledge and attitudes. METHOD: A survey was undertaken of the classes of 1991 and 1994 at the University of Colorado School of Medicine, the University of New Mexico School of Medicine, and the University of South Dakota School of Medicine. The questionnaire contained 40 knowledge questions, 20 attitude questions, and demographic questions. The students reported estimates of HIV-related didactic hours and clinical encounters experienced during their training, as well as the number of HIV-infected individuals known personally. Data analysis employed two-way analysis of variance (ANOVA) and Pearson correlation coefficients. RESULTS: In 1991 the response rates were 73% from Colorado, 54% from New Mexico, and 50% from South Dakota; in 1994 the rates were 80%, 63%, and 60%, respectively. Training programs were similar between schools and over time, varying only in the amounts of didactic information offered. The 1994 students scored significantly better than did 1991 students on knowledge, overall attitude, fear of infection, and willingness to treat HIV-infected patients; these variables were significantly correlated with the numbers of HIV-infected individuals known personally by the students. Didactic training hours were not significantly correlated with any study variable, and clinical experiences were correlated only with increased knowledge. CONCLUSION: Differences in HIV/AIDS prevalences did not affect the schools' training programs, but indirectly affected the students' knowledge and attitudes, which were related to the numbers of HIV-infected individuals known personally by the students. The authors recommend that medical schools increase students' opportunities for meaningful personal contact with HIV-infected individuals.

Academic Medical Centers↗
PubMed1997

Murine model of interleukin-8-induced otitis media.

Interleukin-8 (IL-8), a potent inflammatory mediator that is thought to control leukocyte recruitment and activation during inflammatory reactions, has been implicated in a variety of inflammatory diseases. Recent studies in our laboratory have demonstrated the presence of IL-8 in chronically inflamed human middle ear effusions. These data have led us to hypothesize that IL-8 is responsible for the leukocyte recruitment seen in otitis media. Because the effect of IL-8 on the middle ear mucosa has not been investigated and therefore its role in middle ear inflammation is not known, we investigated the ability of IL-8 to directly induce inflammation in the murine middle ear. For these studies, ICR mice were used to test the hypothesis that IL-8 could directly induce inflammation in the middle ear. Murine middle ears received 8-mL transtympanic injections of human IL-8 (25 mg/mL) in saline, heat-killed Streptococcus pneumoniae (1 x 10(8)/mL), or normal saline. Temporal bones were removed at 1, 4, 8, 24, and 48 hours, decalcified, and processed for histologic examination. Noninjected murine temporal bones served as controls. Normal saline-injected ears demonstrated little to no change as compared with temporal bones from noninjected ears. IL-8-injected ears histologically demonstrated thickening of the epithelial layer and subepithelial space (SES), with inflammatory cell infiltration in the SES peaking at 4 to 8 hours and resolving by 48 hours. Bacteria-injected ears demonstrated findings similar to, although not as extensive as, those found in IL-8-injected ears (i.e., inflammatory reactions peaked at 8 to 24 hours and resolved by 72 hours). Our results demonstrate that IL-8 is a potent inducer of middle ear inflammation and support the concept that IL-8 may be one of the key cytokines responsible for the leukocyte accumulation and activation seen in otitis media.

Animals↗
PubMed1997

American College of Sports Medicine position stand. The Female Athlete Triad.

The Female Athlete Triad is a syndrome occurring in physically active girls and women. Its interrelated components are disordered eating, amenorrhea, and osteoporosis. Pressure placed on young women to achieve or maintain unrealistically low body weight underlies development of the Triad. Adolescents and women training in sports in which low body weight is emphasized for athletic activity or appearance are at greatest risk. Girls and women with one component of the Triad should be screened for the others. Alone or in combination, Female Athlete Triad disorders can decrease physical performance and cause morbidity and mortality. More research is needed on its causes, prevalence, treatment, and consequences. All individuals working with physically active girls and women should be educated about the Female Athlete Triad and develop plans to prevent, recognize, treat, and reduce its risks.

Adolescent↗
PubMed1997

Emergency admission of patients to general surgical beds: attitudes of general practitioners, surgical trainees, and consultants in Liverpool, UK.

OBJECTIVES: To determine (a) whether doctors involved in the process of emergency surgical admission could agree about which patients should be admitted, (b) whether there were consistent differences between doctors in different specialty groups, and (c) whether these opinions were greatly influenced by non-clinical factors. DESIGN: Independent assessment of summarised case histories by three "expert" clinicians (two consultant surgeons and one general practitioner (GP)), by a group of 10 GPs, and by a group of 10 junior and senior surgeons. Experts, but not other observers, scored admissions both independently and as a consensus group. Observers indicated for each patient whether they would admit, would not admit, or were unsure. SETTING: An urban general hospital with teaching status. SUBJECTS: Fifty consecutive patients admitted to the general surgical unit as emergencies during 1995. MAIN OUTCOME MEASURES: Proportion of admissions considered unnecessary or uncertain: agreement between observers on these proportions: effect of social and procedural factors on the admission decision. RESULTS: Between 8 and 34% of admissions were considered unnecessary and 20-38% of unclear necessity. Agreement between the groups of clinicians was not good. GPs and consultant surgeons showed the poorest agreement (kappa = 0.08 to 0.25, 4 comparisons), and the GPs scored a higher percentage of admissions as unnecessary (34 v 8-12%). After discussion, the consensus group achieved good to very good agreement (kappa 0.61-0.84). CONCLUSIONS: Different groups of doctors vary widely in their views about the need for emergency surgical admission. Good agreement can be reached by consensus discussion. GPs are less likely than surgeons to consider emergency surgical admission necessary.

Attitude of Health Personnel↗