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Biomedical subjects

E Johnson

Publications and source records attributed to E Johnson.

At least 217 records · Page 12Linked to original sources
PubMed1993

[Rectal prolapse. Experiences with rectopexy and Delorme's operation].

During the period 1982-91, 52 patients were treated for rectal prolapse. We present the results for 25 treated with Delorme's operation and 14 with rectopexy, all of whom were observed for more than 12 months after operation. Four patients who had internal prolapse were treated with rectopexy. Eight (15%) of 52 patients had postoperative complications, including six in the Delorme group and two in the rectopexy group. A 75 year-old woman operated with rectopexy died from peritonitis. Eight patients (32%) developed recurrent prolapse after Delorme's operation. Five of these were successfully reoperated. No patients in the rectopexy group had a recurrent prolapse. Incontinence and bleeding were reduced in both groups. Despite a relatively high rate of recurrence, we consider Delorme's operation to be a good alternative, also for old debilitated patients, and to involve a minimal risk of serious complications. If recurrence occurs, reoperation can be carried out with good results.

Adult↗
PubMed1993

[Laparoscopic surgery in Norway. Operational statistics from surgical departments after 1990].

In October 1992 all Norwegian hospitals were asked whether or not they currently performed laparoscopic cholecystectomy. 36 hospitals performed laparoscopic surgery, 15 did not and 20 hospitals did not reply. During 1990 six hospitals began to use the laparoscopic technique. The number had increased to 21 hospitals in 1991. Altogether 497 cholecystectomies were performed laparoscopically i 1991, comprising 36% of all cholecystectomies in the 51 responding hospitals. In October 1992 the number of hospitals performing laparoscopic cholecystectomy had increased to 36, and the mini-invasive technique was used in 920 cases, i.e. in 68% of the total number of cholecystectomies. Only approximately 7.5% of all appendectomies were performed laparoscopically in 1992 as well as in 1991. Until 1992, cholecystectomy was the only operation where the mini-invasive technique is widely used in Norway.

Appendectomy↗
PubMed1993

Prediction of cardiovascular death in men undergoing noninvasive evaluation for coronary artery disease.

OBJECTIVE: To develop prediction rules from clinical and exercise test data identifying patients at high and low risk for cardiovascular events among a group of male veterans. DESIGN: Prognostic study with prospective gathering of data and routine follow-up of consecutive patients referred for exercise testing. Patients only underwent noninvasive evaluation for coronary artery disease. No validation cohort is yet available. SETTING: A 1200-bed Veterans Affairs Medical Center. PATIENTS: Of 3609 men referred for exercise testing between 1984 and 1990, 2546 patients remained evaluable after exclusion of those who underwent subsequent cardiac catheterization, those with significant valvular heart disease, and those who had previous coronary artery bypass surgery. MEASUREMENTS: Evaluation included recording of clinical data on a standardized form and a standard treadmill test followed by assessment of cardiovascular events. RESULTS: During a mean follow-up period (+/- SD) of 2.75 (+/- 18) years, 119 cardiovascular deaths and 44 nonfatal myocardial infarctions occurred in 2546 patients. The Cox proportional hazards model showed the following characteristics to be statistically independent predictors of time until cardiovascular death: history of congestive heart failure or digoxin use, exercise-induced ST depression, change in systolic blood pressure during exercise, and exercise capacity. Using a simple score based on one item of clinical information (history of congestive heart failure or digoxin use) and three exercise test responses (ST depression, exercise capacity, and change in systolic blood pressure), 77% of patients were categorized as low risk (annual cardiac mortality rate, less than 2%), 18% as moderate risk (annual cardiac mortality rate, 7%), and 6% as high risk (annual cardiac mortality rate, 15%; hazard ratio, 10; 95% confidence interval, 6 to 17). This model has not yet been validated. CONCLUSIONS: Variables available from the usual non-invasive work-up of patients with known or suspected coronary artery disease can be used to predict future risk for cardiovascular death.

Aged↗
PubMed1993

Chemical exposure in manufacture of phenoxy herbicides and chlorophenols and in spraying of phenoxy herbicides.

Exposure patterns are reported for manufacturing and sprayer cohorts incorporated in the "IARC International Register of Workers exposed to Phenoxy Herbicides and Contaminants." Information was based on company questionnaires, company reports, plant visits, and serum 2, 3, 7, 8-TCDD measurements. In addition to phenoxy herbicides and chlorophenols, workers in manufacturing plants may have been exposed to raw materials, process chemicals, other agents synthesized or formulated, and impurities of all these agents. Sprayers also had a complex exposure pattern, including phenoxy herbicides and some other pesticides, their carriers and additives, and residues of chemicals formed during manufacture. Occurrence of agents, including dioxins, varied between countries. Biological monitoring and industrial hygiene data were rarely available, most since the late 1970s. Exposure of workers depended mainly on the jobs they performed, but several factors influenced level of exposure. A quantitative exposure classification is not feasible in this study. Semiquantitative exposure estimates may be derived through a critical interpretation of biological monitoring and industrial hygiene data together with individual work histories.

2-Methyl-4-chlorophenoxyacetic Acid↗
PubMed1993

Heterosexually acquired human immunodeficiency virus infection and the United States blood supply: considerations for screening of potential blood donors. HIV Blood Donor Study Group.

The impact of heterosexual transmission of the human immunodeficiency virus (HIV) on the United States blood supply was assessed, and deferral criteria that may exclude potential donors who are at high risk for heterosexually acquired HIV infection were evaluated. Interviews were conducted with 508 HIV-seropositive blood donors from May 1, 1988, to August 31, 1989 (Phase 1), and with 472 donors from January 1, 1990, to May 31, 1991 (Phase 2), at 20 blood centers. From Phase 1 to Phase 2, the overall HIV prevalence decreased from 0.021 to 0.018 percent (p < 0.001). HIV risk factors among HIV-1-seropositive donors were similar during both study phases. Eleven percent of the men and 56 percent of the women reported as their only risk that they had a heterosexual partner who was at increased risk for HIV or was known to have HIV. These percentages were similar during both study periods. During Phase 2, 13 percent of the men and 17 percent of the women with heterosexual transmission risk had a positive serologic test for syphilis, hepatitis B core antibody, or hepatitis C antibody. Among HIV-1-seropositive donors reporting heterosexual risk, the median numbers of previous-year and lifetime sex partners for men were 2 and 30, respectively; for women, those numbers were 1 and 7, respectively. Thirty-one percent of the men and 6 percent of the women reporting heterosexual transmission risk also reported having had syphilis or gonorrhea within 3 years of donation. It is concluded that the impact of heterosexual transmission of HIV infection on transfusion safety is not worsening at this time.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Banks↗
PubMed1993

The toxicity of daily inhaled amphotericin B.

Inhaled amphotericin was administered to 29 patients with prolonged neutropenia and toxicity was analyzed. Treatment consisted of 30 mg of amphotericin B administered by nebulizer once daily via either a hand-held nebulizer or face mask. The mean duration of treatment was 16 days. Toxicity was minimal and patient had significant toxic reaction to the inhaled medication. This study documents that nebulized amphotericin B has less than 10% incidence of severe toxicity with 95% confidence level. Guidelines for future trials and use are suggested.

Administration, Inhalation↗
PubMed1993

Phytochrome A null mutants of Arabidopsis display a wild-type phenotype in white light.

Phytochrome is a family of photoreceptors that regulates plant photomorphogenesis; the best-characterized member of this family is phytochrome A. Here, we report the identification of novel mutations at three Arabidopsis loci (fhy1, fhy2, and fhy3) that confer an elongated hypocotyl in far-red but not in white light. fhy2 mutants are phytochrome A deficient, have reduced or undetectable levels of PHYA transcripts, and contain structural alterations within the PHYA gene. When grown in white light, fhy2 mutants are morphologically indistinguishable from wild-type plants. Thus, phytochrome A appears to be dispensable in white light-grown Arabidopsis plants. fhy2 alleles confer partially dominant phenotypes in far-red light, suggesting that the relative abundance of phytochrome A can affect the extent of the far-red-mediated hypocotyl growth inhibition response. Plants homozygous for the recessive fhy1 and fhy3 mutations have normal levels of functional phytochrome A. The FHY1 and FHY3 gene products may be responsible for the transduction of the far-red light signal from phytochrome A to downstream processes involved in hypocotyl growth regulation.

Arabidopsis↗
PubMed1993

Genetic differentiation of cocoa (Theobroma cacao L.) populations revealed by RAPD analysis.

In order to preserve and exploit the valuable genetic resources of tropical forest trees, such as cocoa, a systematic assessment of the available genetic variability is necessary. The approach we have used is based on a simple mini-prep DNA extraction procedure together with a polymerase-chain-reaction- (PCR)-based polymorphic assay procedure (RAPD). Twenty-five cocoa accessions: IMCs and PAs collected from Peru and LCTEENs collected from Ecuador, which are difficult to distinguish using morphological or biochemical descriptors, were uniquely fingerprinted using a minimum of three oligonucleotide primers. Analysis of the variability detected using RAPDs clearly discriminated between the geographical origin of the three cocoa populations. Partitioning of variability into within and between population components revealed that most variation was detected within a population. The potential of RAPD analysis to facilitate the rationalization of field gene banks and provide accurate estimates of diversity to allow optimization of collecting strategies is discussed.

Base Sequence↗
PubMed1993

Bleomycin affects cell wall anchorage of mannoproteins in Saccharomyces cerevisiae.

Bleomycin induces strand breakage in DNA through disruption of glycosidic linkages. We investigated the ability of bleomycin to damage yeast cell walls, which are composed primarily of carbohydrate. Bleomycin treatment of intact yeast cells facilitated enzymatic conversion of yeasts to spheroplasts. Bleomycin treatment also altered anchorage of mannoproteins to the cell wall matrix in intact cells or isolated cell walls. Cell surface mannoproteins were labelled with 125I, and their solubilization was monitored. Seventeen hour treatments with bleomycin released some of the label directly into treatment supernatants and facilitated extraction of mannoproteins by dithiothreitol and lytic enzymes. Bleomycin treatments as short as 10 min caused changes in extraction of mannoproteins from intact cells. Specifically, cell wall anchorage of several mannoproteins was affected by the drug. There were drug-induced changes in extractability of mannoproteins with apparent molecular weights of 96,000, 80,000, 61,000, 41,000, 31,500, and 21,000 (determined after deglycosylation with endo-N-acetylglucosaminidase H). The similarity of results obtained in the presence and absence of cycloheximide, the appearance of cell wall effects after only 10 min of treatment, and the similarity of effects in intact cells and isolated cell walls are consistent with direct drug-induced damage and inconsistent with a mechanism dependent on expression of bleomycin-damaged genes or other intracellular mediators. The results are consistent with bleomycin-mediated increases in cell wall permeability through disruption of glycosidic cross-linking structures in the cell wall.

Bleomycin↗
PubMed1993

Chemical pleurodesis in malignant pleural effusions: a randomised prospective study of mepacrine versus bleomycin.

BACKGROUND: The treatment of recurrent pleural effusion in advanced malignant disease should be efficient and with tolerable side effects. Since 1983 intrathoracic instillation of the anti-malaria drug mepacrine has been used to achieve pleurodesis. The cytotoxic drug bleomycin has been claimed to be equally effective and with fewer side effects. The present study was designed to compare these two agents. METHODS: Forty patients with carcinoma and pleural effusions refractory to repeated pleural aspirations over the previous 12 weeks were randomised to receive treatment with intrathoracic instillation of mepacrine or bleomycin. Fluid volumes before and after pleurodesis, drainage time, and side effects were registered and analysed, and the response to treatment was evaluated by clinical examination and chest radiography. RESULTS: The amount of fluid produced after treatment in the patients receiving mepacrine was lower than in those receiving bleomycin, and the duration of chest drainage was shorter. After 30 days 16 of 20 in the mepacrine group responded to treatment and 10 of 20 in the bleomycin group. Most patients died during the three months observation period. Moderate side effects occurred equally in both groups. CONCLUSIONS: Chemical pleurodesis can reduce or stop pleural effusion in many patients, and in this study mepacrine appeared to be more efficient than bleomycin. A prospective study with a larger number of patients is now warranted.

Adult↗
PubMed1993

Socioeconomic status and prediction of ventricular fibrillation survival.

OBJECTIVES: The association between socioeconomic status and cardiac arrest is less well known than some other associations with cardiac arrest. We used property tax assessments as a measure of socioeconomic status in a study of victims of out-of-hospital cardiac arrest found in ventricular fibrillation. METHODS: We studied patients attended by the Seattle Fire Department's emergency medical services system between May 1986 and August 1988. During the period studied, 356 episodes met the study criteria; 114 (32%) of these patients survived without major neurologic deficit. Residential property tax assessments were available for 253 of the patients. RESULTS: After adjustments were made for age, witnessed collapse, bystander-initiated cardiopulmonary resuscitation, time from call to paramedic arrival, activity, location of collapse, and chronic morbidity, an association of survival with greater assessed value per living unit was observed. An increase of $50,000 in value per unit was associated with a 1.6-fold increase in survival rate. CONCLUSIONS: Not only are persons in the lower socioeconomic strata at greater risk for cardiac mortality, but they are also less likely to survive an episode of out-of-hospital cardiac arrest.

Aged↗
PubMed1993

Effect of formulation adjuvants on gastrointestinal absorption of leuprolide acetate.

Leuprolide acetate, [D-Leu6-desGly10]LH-RH ethylamide, a highly potent superagonist of luteinizing hormone-releasing hormone (LH-RH), was administered by intraduodenal (ID) injection to male castrate rats in a saline solution. Absorption was low, approximately 0.01% and 0.08% by oral (PO) and ID administration respectively, compared with intravenous (i.v.) controls. An aqueous formulation and a water in oil emulsion of a lipophilic salt, a decane sulfonic acid derivative of [D-Leu6-desGly10]LH-RH ethylamide gave ID bioavailabilities of approximately 0.2% and 1%, respectively. Evaluation of formulation effects on the oral absorption of leuprolide showed that lipophilicity, surfactant and vehicle properties significantly affected ID absorption of leuprolide. Absolute bioavailability of the drug in typical emulsion systems ranged from approximately 3 to 10% and represent an improvement of about 100 fold in gastrointestinal bioavailability of this peptide. The implications of these findings relative to the effect of formula adjuvants on oral absorption of leuprolide and other peptides following ID administration are discussed.

Adjuvants, Pharmaceutic↗
PubMed1993

Digoxin-like factors in herbal teas.

Forty-six commercially packaged teas and 78 teas prepared from purchased herbs were assayed for digoxin-like factors (DLF) by their crossreactivity with digoxin antibody (immuno-crossreactive DLF) and by their inhibition of ouabain binding to membrane Na,K-ATPase (NKA inhibitory DLF). Three packaged teas and 3 herbs gave NKA inhibitory DLF values > 30 micrograms digoxin equivalents/cup. Two packaged teas and 3 herbs gave immuno-crossreactive DLF values > .050 micrograms digoxin equivalent/cup. One herb, pleurisy root, had a crossreactive DLF value of 187 micrograms/cup and NKA inhibitory DLF equivalent to 3658 micrograms/cup. Plasma digoxin-like factors were measured after ingestion of the 3 commercially packaged herbal teas with highest values for NKA inhibitory DLF. After ingestion of each of the 3 teas, plasma NKA inhibitory DLF increase, in one case more than 100-fold. Two teas produced a measurable increase in plasma immuno-crossreactive DLF after ingestion. Some digoxin-like factors in human plasma may have a dietary source.

Beverages↗
PubMed1992

Ultrastructure of spared dopamine terminals in caudate-putamen nuclei of adult rats neonatally treated with intranigral 6-hydroxydopamine.

Residual dopamine terminals in the dorsal striatum, caudate-putamen nuclei (CPN), of adult rats neonatally lesioned with 6-hydroxydopamine (6-OHDA) sustain a relatively high level of dopamine release. We examined whether there were morphological differences in the spared dopamine terminals that might correlate with this increased efficacy. Postnatal male rat pups from 50 litters were pretreated with desmethylimipramine (DMI) to protect from non-specific monoamine damage, then given unilateral intranigral injections of 6-OHDA or vehicle. Coronal sections through the CPN and substantia nigra of the surviving adult animals from each litter were co-processed for immunoautoradiographic or immunoperoxidase localization of the catecholamine synthesizing enzyme, tyrosine hydroxylase (TH). Quantitative ultrastructural analysis established that in animals showing maximal (greater than 90%) depletions in immunoautoradiographic labeling for TH, the number of TH-labeled axons in the CPN ipsilateral to the 6-OHDA injections was reduced to one third of the number seen in the contralateral, unlesioned hemisphere, or the CPN from vehicle-injected animals. The ultrastructural features of residual terminals ipsilateral to 6-OHDA lesions were morphologically similar to those of the contralateral side or in vehicle-injected animals. However, in comparison with controls, these TH-labeled terminals had significantly larger mean cross-sectional diameters. When subdivided into groups according to size, there were significantly fewer small (0.0-0.1 micron 2) and more large (0.41-0.50 micron 2) TH-immunoreactive profiles in lesioned versus unlesioned CPN. The remaining TH-labeled terminals ipsilateral to the 6-OHDA lesions also appeared to be more often in direct contact with unlabeled soma and proximal dendrites as opposed to dendritic spines in the unlesioned CPN. These results suggest that the enhanced activity of dopamine neurons innervating the CPN after nigral 6-OHDA lesions may contribute to changes in size and target of their terminals. Alternatively, the observed large size of remaining dopamine terminals may reflect selective vulnerability of smaller axons to 6-OHDA toxicity.

Aging↗
PubMed1992

An isoform of protein disulfide isomerase isolated from chronic myelogenous leukemia cells alters complex formation between nuclear proteins and regulatory regions of interferon-inducible genes.

We have previously shown that the electrophoretic mobility of complexes formed in vitro between nuclear proteins and the regulatory domains of interferon-inducible genes is altered by an extranuclear protein present in elevated levels in the myeloid cells of chronic myelogenous leukemia patients. Interferon-alpha reduces the level of this activity only in the cells of patients who are clinically sensitive to the antiproliferative effects of interferon-alpha. We have purified this protein to homogeneity and found it to be a 57-kDa protein which corresponds to an isoform of protein disulfide isomerase. Protein disulfide isomerase is an oxidoreductase which catalyzes the interconversion between the reduced and oxidized states of proteins which contain multiple sulfhydryl groups and disulfide bonds. These studies suggest that this protein may play an important role in the transcriptional activation of interferon-inducible genes, perhaps through redox mechanisms.

Base Sequence↗