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Biomedical subjects

B Johnson

Publications and source records attributed to B Johnson.

At least 55 records · Page 3Linked to original sources
PubMed1999

Chronic mentally ill individuals reentering the community after hospitalization. Phase II: The urban experience.

The purpose of this qualitative study was to explore the experiences of persons reentering an urban community after hospitalization for mental illness. The sample consisted of five men and three women, aged early 30's to mid-50's, mostly diagnozed with schizophrenia, and who had had several hospitalizations within the previous year. Most returned to places where they had lived before, frequently to boarding homes for former psychiatric patients. Most lived alone. Each participant was interviewed shortly before discharge and one to two times in the community. The tape-recorded interviews were analyzed according to the Giorgi method. Three themes emerged from the data, related, respectively, to the hospital and its environs remaining a focus of the participants' lives, the added burden of social and financial conditions, and the presence of goals which nevertheless had barriers to their achievement. Contrasts are drawn with the findings of Phase I (Montgomery & Johnson 1998), in which there was found a much stronger sense of discharge marking a new beginning. The findings add to our knowledge about what it is like for chronic mentally ill individuals to live outside hospital, but also raise questions about the influence of particular diagnoses, community characteristics and changes in adjustment over time.

Adaptation, Psychological↗
PubMed1999

A study of client-focused case management and consumer advocacy: the Community and Consumer Service Project.

OBJECTIVE: The study investigated the provision of client-focused services to community-based clients with schizophrenia and bipolar disorder. It hypothesised that the delivery of more client-focused services would improve client outcome in terms of functioning, disability and satisfaction with services. Client-focused services were developed using an empowerment model of case management and by the addition of consumer advocates. METHOD: Clients referred for case management were randomly allocated to one of three groups: standard case management (n = 35), client-focused case management (n = 39), or client-focused case management plus consumer advocacy (n = 45). Measures of functioning, disability, quality of life, burden of care and service satisfaction were measured at baseline and 12 months. Outcome data were collected concerning number and duration of hospital readmission, crisis intervention and compliance with treatment and services. RESULTS: While there were no differences between the groups on quantitative measures of functioning, disability, quality of life, service satisfaction and burden of care, there were significant between-group differences on qualitative measures of satisfaction with services. CONCLUSIONS: Several methodological difficulties hampered interpretation of the findings. Although clients did not differ on outcome measures of functioning and disability, the group receiving client-focused case management reported greater satisfaction with service delivery.

Adolescent↗
PubMed1999

Cross-study hierarchical modeling of stratified clinical trial data.

Hierarchical random-effects models can be used to estimate treatment or other covariate effects in single-study analyses coordinated over multiple clinical units and can also be extended to a wide variety of cross-study applications. After reviewing the single-study case, we use data from five trial protocols to look for units that tend to have treatment effects consistently above or below the study-specific grand mean across several studies. As a first step, we summarize the patient-level data as study-specific and unit-specific estimated treatment effects and standard errors using independent Cox regression models. We then compare the results of a hierarchical model using these data summaries as input to those produced by a more fully Bayesian method that uses the actual patient-level survival data. We also compare various different models using a deviance information criterion, a recent extension of the Akaike information criterion designed for hierarchical models. Our procedure appears to be effective at answering the question whether certain clinical units of the Terry Beirn Community Programs for Clinical Research on AIDS are better than others at identifying treatment effects where they exist.

AIDS-Related Opportunistic Infections↗
PubMed1999

Spiradenoma arising in a nevus sebaceus of Jadassohn: case report and literature review.

Nevus sebaceus (NS) of Jadassohn is usually a verrucous plaque on the scalp or face that arises secondary to disordered development of epithelial, pilar, sebaceous, and apocrine structures. The emergence of neoplasia is a late stage in the natural history of NS. Although most neoplastic proliferations are benign, several malignant tumors have arisen in this lesion. We describe the first case of a benign spiradenoma arising in an NS on the scalp in a 72-year-old Caucasian woman. Reexcision was recommended to prevent the development of a second neoplastic process and to avoid the rare occurrence of a malignant transformation of the existing neoplasia. The patient declined reexcision and remains under observation. The spectrum of tumors arising in NS are described and are categorized according to behavior. Syringocystadenoma papilliferum is the most commonly observed benign growth, whereas basal cell carcinoma is the most frequently seen malignant process. The signs of tumor development (benign or malignant) within an NS are reviewed, and treatment recommendations are provided. The clinical course of rare and unique aggressive neoplasms originating in NS is summarized.

Adenoma, Sweat Gland↗
PubMed1999

Preferential cerebrospinal fluid acetylcholinesterase inhibition by rivastigmine in humans.

This study sought to examine the feasibility of prolonged assessment of acetylcholinesterase (AChE) activity in the cerebrospinal fluid (CSF) of volunteers and to test the hypothesis that rivastigmine (ENA-713; Exelon, Novartis Pharma AG, Basel, Switzerland) selectively inhibits AChE in CSF in humans at a dose producing minimal inhibition of the peripheral enzyme. Lumbar CSF samples were collected continuously (0.1 mL x min(-1)) for 49 hours from eight healthy volunteers who took either placebo or a single oral dose of rivastigmine (3 mg). CSF specimens and samples of blood cells and blood plasma were analyzed at intervals for rivastigmine and its metabolite NAP 226-90 ([-] [3-([1-dimethylaminolethyl)-phenol]), erythrocyte AChE activity, CSF AChE activity, and plasma and CSF butyrylcholinesterase (BuChE) activity. Safety evaluations were performed 23 hours after drug dosing and at the end of the study. Evaluable data were obtained from six subjects. The mean time to maximal rivastigmine plasma concentration (tmax) was 0.83 +/- 0.26 hours, the mean maximal plasma concentration (Cmax) was 4.88 +/- 3.82 ng x mL(-1), the mean plasma area under the concentration versus time curve (AUC0-infinity) was 7.43 +/- 4.74 ng x hr x mL(-1), and the mean plasma t1/2 was 0.85 +/- 0.115 hours. The concentration of rivastigmine in CSF was lower than the quantification limit for assay (0.65 ng x mL(-1)), but NAP 226-90 reached a mean Cmax of 3.14 +/- 0.57 ng x mL(-1). Only minimal inhibition of erythrocyte AChE activity (approximately 3%) was observed. Inhibition of AChE in the CSF after rivastigmine administration was significantly greater than after placebo for up to 8.4 hours after the dose and was maximal (40%) at 2.4 hours. Plasma BuChE activity was significantly lower after rivastigmine than after placebo, but this was not clinically relevant. BuChE activity in CSF was significantly lower after rivastigmine than after placebo for up to 3.6 hours after dosing, but this difference was not sustained. This study confirms the feasibility of using continuous measurement of AChE activity in CSF over prolonged periods, that rivastigmine markedly inhibits CSF AChE after a single oral dose of 3 mg, and that the inhibition of central AChE is substantially greater than that of peripheral AChE or BuChE.

Acetylcholinesterase↗
PubMed1999

Crystallization by settling in suspensions of hard spheres.

We examine crystallization by settling for two different model hard-sphere suspensions. Sedimentation velocities, internal shock velocities, and crystal growth velocities are measured. Dynamic light scattering experiments measure volume fraction profiles in fluid phases, while Bragg scattering experiments determine volume fraction profiles in crystal phases. Centrifugation experiments determine the particle Péclet number above which samples will not crystallize. The sedimentation velocities, as a function of volume fraction, agree with other "hard-sphere" data. Remarkably, the value of the reduced crystal growth velocity (approximately 0.075) obtains for two orders of magnitude of the particle Péclet number. Kynch theory provides an adequate description of the data in the fluid phase, but is less adequate for volume fraction profiles in the crystal phase. The crystals in the dense sediment are compressed more along a vertical axis relative to the horizontal axis. Predicted Wilson-Frenkel crystal growth velocities, calculated using known hard-sphere equations of state and a short-time self-diffusion constant, rationalize the measured crystal growth velocities.

Journal Article↗
PubMed1999

Cross-sectional study of gastric ulcers of the squamous mucosa in thoroughbred racehorses.

Although gastric ulcers have been identified relatively frequently in racing Thoroughbreds, there have been no large scale studies to determine their effect on health and performance. Two hundred and two Thoroughbred horses in active race training were selected by the attending veterinarians for gastro-endoscopic examination. Images of the stomach mucosa were stored in a digitised format for subsequent evaluation. The number of ulcers and a score of severity were determined. Gastric ulceration of the squamous mucosa was identified in 82% of horses. Seventy-three (39%) horses displayed clinical signs consistent with gastric ulceration. Increasing Furr and Murray Score was associated with poor hair coat (P = 0.03), colic (P = 0.03), and increasing serum creatinine concentration (P = 0.029). There were no associations between haematology and serum biochemistry values (other than serum alkaline phosphatase concentration and serum creatinine concentration) and gastric ulceration. Our study confirmed the relatively high incidence of gastric ulceration in Thoroughbred horses involved in active race training. Gastric ulceration is a potential, but rare, cause of overt colic, but may produce more subtle detrimental effects on a horse's condition. It is concluded that the diagnosis of gastric ulceration should be based on an endoscopic examination of the stomach, although future studies are required to elucidate further the aetiology and clinical significance of gastric ulceration.

Animals↗
PubMed1999

Three perspectives on addiction.

Three perspectives on addiction promulgated during the 1990s are reviewed, along with many earlier contributions to the understanding of addictive illness. It is suggested that these distinct yet overlapping formulations of the dynamics of addiction form a hierarchy for each patient suffering from an addiction. Assessment of a patient's ego strength, and of the relative importance of addictive behaviors in overall character structure, allows referral to various types of treatment, including psychoanalytic therapy. Case examples are presented, including material from the psychoanalysis of a woman addicted to heroin, methadone, cocaine, amphetamines, nicotine, alcohol, and shopping.

Adult↗
PubMed1999

Evaluations of the effects of Sweden's spanking ban on physical child abuse rates: a literature review.

Sweden's 1979 law banning corporal punishment by parents was welcomed by many as a needed policy to help reduce physical abuse of children. This study reviews the published empirical evidence relevant to that goal. Only seven journal articles with pertinent data were located. One study reported that the rate of physical child abuse was 49% higher in Sweden than in the USA, comparing its 1980 Swedish national survey with the average rates from two national surveys in the United States in 1975 and 1985. In contrast, a 1981 retrospective survey of university students suggested that the Swedish abuse rate had been 79% less than the American rate prior to the Swedish spanking ban. Some unpublished evidence suggests that Swedish rates of physical child abuse have remained high, although child abuse mortality rates have stayed low there. A recent Swedish report suggested that the spanking ban has made little change in problematic forms of physical punishment. The conclusion calls for more timely and rigorous evaluations of similar social experiments in the future.

Child Abuse↗
PubMed1999

Survivors' perspectives on the impact of prostate cancer: implications for oncology nurses.

Providing effective care for individuals with prostate cancer is an important issue for oncology nurses. However, the paucity of empirical work regarding the impact of prostate cancer presents a limitation in designing and implementing appropriate nursing interventions. This article presents the findings from a national survey of 621 Canadian men living with prostate cancer regarding the impact of their disease and the availability of support. The most frequently identified problems included sexual function, side effects, fear of dying, incontinence, anger and pain. Approximately one-third of the respondents experienced a lifestyle change, but relatively few indicated experiencing a negative impact from the changes they experienced. The majority of respondents indicated they had been informed accurately about their treatment, but dissatisfaction was expressed regarding lack of information about emotional reactions, alternative therapies, how to speak with other prostate cancer patients and the availability of counselling and self-help groups. Clearly these results have implications for oncology nurses.

Adaptation, Psychological↗
PubMed1999

Weighing risks and taking chances: adolescents' experiences of the regimen after renal transplantation.

The purpose of this study, which used a descriptive qualitative design, was to describe adolescents' experiences of the treatment regimen that follows renal transplantation in order to gain a better understanding of their experience. Five adolescents each participated in one in-depth, semistructured interview. Participants were asked to speak about the requirements of the recommended regimen related to medications, blood pressure and fluid monitoring, and diet and activity restrictions. The interviews were analyzed using Giorgi's data analysis method. The following overarching theme was identified: Weighing risks and taking chances. The consequences of the regimen and adhering or nonadhering to it were evident in the physiological, social, and psychological domains. Following the initial period, the adolescents were more selective in their adherence to the regimen, based on their perceptions of the risks involved in modifying the regimen. The modifications made to the posttransplantation regimen, which at times placed the adolescents' health at risk, were influenced by how the regimen interfered with their daily routines, such as school, leisure activities, and peer reactions as well as changes in their self-concept and self-image.

Adolescent↗
PubMed1998

Blue-green algae toxicosis in cattle.

Twenty-four of 175 heifers died after ingesting water from a stock pond containing blue-green algae (genus Microcystis) in southern Colorado. Affected cattle were found dead or had signs of nervousness, and were recumbent, weak, anorectic, and hypersensitive to noise when first examined. All cattle died within 3 days after the onset of signs. At necropsy, the rumen contained blue-green algae, and the liver was larger than normal, friable, and dark red. The most important histologic lesion was hepatocyte degeneration and necrosis. Intraperitoneal administration of lyophilized cell material from the bloom caused hepatic necrosis and death in mice, and water from the pond had clumps of cells surrounded by a clear calyx, consistent with the appearance of organisms of the genus Microcystis. Samples of pond water were examined by means of high-pressure liquid chromatography; microcystin-LR, one of the hepatotoxins produced by Microcystis spp, was found. Chromatography may be useful in the diagnosis of blue-green algae toxicosis.

Animals↗
PubMed1998

Effects of acute intravenous cocaine on cardiovascular function, human learning, and performance in cocaine addicts.

Continuous non-invasive cardiovascular monitoring in eight healthy cocaine addicts receiving intravenous cocaine (0.325 mg/kg or 0.650 mg/kg) or placebo in double-blind, randomized, cross-over fashion demonstrated significant dose-dependent increases in pulse and mean arterial pressure following cocaine. Pulse and mean arterial pressure peaked 5 min post-cocaine injection and maximal response was sustained for a further 15 min and 35 min afterwards, respectively. Cocaine administration had no significant effect on peripheral oxygen saturation, and no clinically significant abnormalities of rhythm or conduction were seen on the electrocardiogram. These doses and method of single-dose intravenous cocaine administration, and our procedures for cardiovascular monitoring, appear relatively safe for laboratory studies of healthy cocaine addicts with no pre-existing cardiovascular disease. In addition, cocaine-taking (0.325 mg/kg i.v. and 0.650 mg/kg i.v.) was associated with enhanced attention (i.e. increased numbers of correct responses on the Rapid Visual Information Processing Task), but the trend towards reduced reaction time did not achieve statistical significance. Cocaine-taking resulted in a small but statistically insignificant improvement in learning on the Digit Symbol Substitution Task. These results suggest that cocaine-taking in rested subjects is associated with some cognitive enhancement.

Adult↗
PubMed1998

Recombinant interleukin 2 adjunctive therapy in multidrug-resistant tuberculosis.

Multidrug-resistant tuberculosis patients respond poorly to antituberculosis therapy and therefore require new modalities of treatment to overcome the infection. Administration of low dose recombinant human interleukin 2 (rhuIL-2) in combination with chemotherapy to multidrug-resistant tuberculosis patients resulted in reduced or cleared sputum acid-fast bacilli in about 60% of the patients in association with enhanced activation of the immune system. Daily rhuIL-2 administration for 30 days induced increases in CD25+ and CD56+ cells in the blood. rhuIL-2 therapy also resulted in increased expression of gamma-interferon and IL-2 mRNA at the site of a delayed-type hypersensitivity (DTH) response to purified protein derivative of tuberculin. Differential display reverse transcriptase PCR revealed several genes expressed at the DTH skin test site that were up- or down-regulated during rhuIL-2 treatment. The differentially regulated genes included components of endocytic vacuoles, enzymes of the respiratory pathway and other regulators of cellular function. The physiological importance of the differential expression of these genes is under investigation to determine their roles in leukocyte activation and in the development of an antimycobacterial response.

Adjuvants, Immunologic↗