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Biomedical subjects

R Klein

Publications and source records attributed to R Klein.

At least 667 records · Page 37Linked to original sources
PubMed1989

The politics of modernization: Britain's National Health Service in the 1980s.

The history of the British National Health Service (NHS) over the past decade demonstrates both institutional adaptation and insulation from more basic structural change. Reflecting international trends, the NHS has, on the one hand, recentralized decision making, adopted strong managerialist policies, accommodated a modicum of privatization, and stressed the client's role in some service choices. On the other hand, the government has skirted introducing unbridled competition into the health service. Assessment of a 1989 "Government Review" highlights the tensions the NHS faces between budgetary pressures and consumer demands, and between centralized controls and medical autonomy, among others.

Delivery of Health Care↗
PubMed1989

[Nonspecific eye autoantibodies in uveitis].

Under certain pathologic circumstances autoantigens lead to the formation of autoantibodies. In uveitis, autoimmunologic phenomena will also be discussed. We studied 149 sera of uveitis patients for various organ specific and non-organ specific autoantibodies. We found antisarcolemal autoantibodies (ASA) mainly in patients with acute iritis (59% positive) but also in panuveitis (40%) and iridocyclitis (29%). On the other hand antiendothelial antibodies (AEA) could be found in 43% of patients with chorioretinitis. Antisinusoidal antibodies (SA) have been detected in iritis and panuveitis patients more often than in the control group which show positive autoantibodies in 5% of all cases. Using ELISA we looked for antibodies against keratin, laminin and microsomes. Because antimicrosomal-, antilaminin- and antisarcolemal-antibodies recognize the same epitope, there was a good correlation of these three autoantibodies. Similar clusters of autoantibodies (ASA, AEA and SA) have been found in various infectious diseases and in chronic inflammatory diseases in which an infectious component is discussed. These results may indicate that iritis, iridocyclitis, chorioretinitis and panuveitis are secondary reactions of eye tissue following a systemic primary disease. Especially viruses are well-known for their production of autoantibodies. In patients with intermediate uveitis we could not demonstrate these autoantibodies more often than in the control group, favouring theories which believe in an autoimmune reaction against vitreous elements.

Antibodies, Antinuclear↗
PubMed1989

Treatment of adolescents in a residential facility: a study of three approaches.

This study examined the preferred professional treatment approach at a residential treatment center for socially and emotionally maladjusted girls. The dorm child-care workers and the clinical and educational staff responded to a questionnaire composed of statements reflective of three theoretical orientations: psychoanalytic, person-centered, and cognitive-behavioral therapy. No significant differences were found between the three departments (clinical, school, dorm) for each model of therapy. The results also indicated that the professional personnel employed at this treatment facility were all in agreement that the cognitive-behavioral model of therapeutic intervention is the one preferred. Implications of these findings are discussed.

Adolescent↗
PubMed1989

Thymic epithelial cultures 30 years ago, and their interpretation.

In cultures of human fetal thymus giant cells comprising of epithelial cells and lymphocytes were observed. These epithelial-lymphocyte complexes are interpreted with regard to the growth and cell division of lymphocytes. These observations were the first on in vitro nurse cell formation.

Cell Division↗
PubMed1989

Are seven standard photographic fields necessary for classification of diabetic retinopathy?

Stereoscopic fundus photography of seven fields has become standard procedure for detecting diabetic retinopathy. However, the question has arisen as to whether adequate detection of retinopathy can be achieved with fewer fields. This question was investigated in a population-based study of 2694 diabetic persons. Retinopathy levels derived from the detailed grading of all seven fields were compared with those derived from combinations of two, three or four fields, the data for these being selected from the grading of the full seven fields. For eight retinopathy levels, the rate of agreement with seven fields ranges from 80% for two fields to 91% for four fields. For four retinopathy levels, agreement increases to 85 to 95%. The rate of agreement also varies with the specific retinopathy level, with level 65 being especially sensitive to the number of fields. The sensitivity of two to four fields compared to seven fields for detecting any retinopathy varies from 87 to 95%. For detecting proliferative retinopathy, sensitivity varies from 74 to 90%, and for Diabetic Retinopathy Study high-risk characteristics, it varies from 81 to 91%. Analysis of two groups of 50 eyes in which the combinations of fields were graded independently shows a small but nonsignificant effect of field overlap. These results indicate that in some situations, fewer fields may be adequate.

Diabetic Retinopathy↗
PubMed1989

Is blood pressure a predictor of the incidence or progression of diabetic retinopathy?

The relationship between blood pressure and the 4-year incidence and progression of diabetic retinopathy was examined in a population-based study in Wisconsin. Younger- (n = 891) and older-onset (n = 987) persons participating in baseline and follow-up examinations were included. Blood pressure was measured using the Hypertension Detection and Follow-up Program protocol. Retinopathy was determined from stereoscopic fundus photographs. In the younger-onset group, comparing the highest with the lowest quartile of systolic blood pressure, the relative risk for developing any diabetic retinopathy was 1.8 and for diastolic blood pressure it was 1.2; for progression of diabetic retinopathy, it was 1.1 and 1.3 for systolic and diastolic blood pressure, respectively. After controlling for other risk variables, systolic blood pressure remained a significant predictor of the incidence of diabetic retinopathy; diastolic blood pressure was of borderline significance in predicting progression in the younger-onset group. Blood pressure was not related to incidence or progression of retinopathy either in the older-onset group using insulin or the older-onset group not using insulin.

Age Factors↗
PubMed1989

Optic disc cupping: prevalence findings from the WESDR.

Increased cupping of the optic disc is considered to be an indication of pressure-related damage of the optic nerve. This paper explores the relationship of intraocular pressure and cupping in persons with diabetes mellitus, a group of people whose optic nerves may be more susceptible to the effects of intraocular pressure. Stereoscopic fundus photographs of the seven standard fields were obtained in all persons participating in the Wisconsin Epidemiologic Study of Diabetic Retinopathy at the time of the initial prevalence survey. Measurements of disc and cup diameters in the vertical and horizontal meridia were made by two trained graders. Cup-to-disc ratios were computed for both diameters of each eye and the mean of the two gradings was used. A history of glaucoma was significantly associated with larger cup-to-disc ratios at the prevalence examination. Cup-to-disc ratios were not larger in those with high IOP, nor in those who had panretinal photocoagulation.

Adult↗
PubMed1989

Optic disc cupping: four year follow-up from the WESDR.

Change in optic disc cupping was evaluated in a 4-year follow-up of a well defined cohort of people with diabetes mellitus. Cup-to-disc ratios were computed for both vertical and horizontal diameters of each eye at the baseline and 4-year follow-up examinations. Graders were masked as to the identity of participants and to the dates of the photographs. Increases of at least 0.1 between baseline and follow-up were used as clinically significant change in the ratios. None of the following factors at baseline were consistent predictors of such a change: intraocular pressure, age, duration of diabetes, hypertension or severity of diabetic retinopathy. People who developed proliferative retinopathy by the follow-up examination were not more likely to have such an increase in ratio at the follow-up. We conclude that clinically significant increases in cup-to-disc ratio cannot be consistently predicted in people with diabetes from the risk factors evaluated with the grading system used in this study.

Diabetes Complications↗
PubMed1989

Relation of ocular and systemic factors to survival in diabetes.

The relationship of survival to systemic and ocular factors in diabetic persons was studied using data collected as part of the Wisconsin Epidemiologic Study of Diabetic Retinopathy. Six years after the baseline examination, 9.5% of 996 insulin-taking people who were younger than age 30 years when their diabetes was diagnosed (younger onset) had died. Of 1370 people whose diabetes was diagnosed after age 30 years (older onset), 35.3% had died. After adjusting for age and sex, longer duration of diabetes, presence of proteinuria, a history of cardiovascular disease, higher blood pressure, diuretic use, a history of smoking, poorer visual acuity, and more severe retinopathy were significantly associated with decreased survival in both groups. Glaucoma was associated with decreased survival in the younger onset group and cataract in the older onset group. These findings suggest that some ocular complications are important risk indicators for death. Their presence in diabetic patients suggests the need for frequent examinations to detect systemic complications and to intervene to minimize their effect.

Adult↗
PubMed1988

Phorbol 12-myristate 13-acetate modulates the cAMP-induced light-scattering response of a Dictyostelium discoïdeum cell population.

The effect of phorbol 12-myristate 13-acetate upon the light-scattering response to cAMP of a D. discoïdeum cell suspension was investigated. It was found that the first spike of the cAMP-mediated light-scattering change (peaking at about 15-20 s after stimulation) was inhibited by the phorbol ester. This effect was concentration dependent with an half-maximum value for the inhibition of 4 nM. The inhibition was found to be maximal after a 10-20 min incubation time. The phorbol ester was shown to affect the dose-response relationship between the cAMP concentration and the relative amplitude of the light-scattering change, more by decreasing the number of cAMP receptors than by decreasing their apparent affinity for cAMP.

Chemotaxis↗
PubMed1988

Glycosylated hemoglobin predicts the incidence and progression of diabetic retinopathy.

The relationship between hyperglycemia, measured by glycosylated hemoglobin at the initial examination, and the four-year incidence and progression of diabetic retinopathy was examined in a population-based study in Wisconsin. Younger- (n = 891) and older-onset (n = 987) persons participating in baseline and follow-up examinations were included. Glycosylated hemoglobin was measured by microcolumn. Retinopathy was determined from stereoscopic fundus photographs. In the younger-onset group, comparing the highest with the lowest quartile of glycosylated hemoglobin, the relative risk for developing any diabetic retinopathy was 1.9; for proliferative retinopathy, 21.8; and for progression, 4.0. Among older-onset persons taking insulin, the corresponding relative risks were 1.9, 4.0, and 2.1. Among older-onset persons not taking insulin, relative risks were 4.0 for any retinopathy and 6.2 for progression. A positive relationship between incidence and progression of retinopathy and glycosylated hemoglobin remained after controlling for duration of diabetes, age, sex, and baseline retinopathy. These data suggest a strong and consistent relationship between hyperglycemia and incidence and progression of retinopathy.

Adult↗
PubMed1988

[Prognostic significance of antimitochondrial antibody profiles A-D in primary biliary cirrhosis].

Sera from 550 patients with primary biliary cirrhosis were tested by ELISA and the complement-fixation test (CFT) for the antimitochondrial antibodies (AMA) anti-M2, anti-M4, anti-M8 and anti-M9. Four profiles were defined and correlated with morphological and biochemical criteria - A: only anti-M9 positive by ELISA; B: anti-M9 and (or) anti-M2 positive by ELISA; C: anti-M2, anti-M4 and (or) anti-M8 positive by ELISA; D: anti-M2, anti-M4 and (or) anti-M8 positive by ELISA; D: anti-M2, anti-M4 and (or) anti-M8 positive by ELISA and CFT. Liver biopsies were obtained in 385 patients. Analysis of histological stage at the time of first serological testing revealed PBC stages I/II or only nonspecific lesions in all group A patients and in 90% of group B patients, while 49% of patients in group C and 59% of those in group D had stage III/IV or had histological features of chronic active hepatitis or "mixed form". Levels of alkaline phosphatase and GPT were significantly higher in groups C/D than groups A/B patients (P less than 0.05), and bilirubin and IgG levels were more frequently elevated in the former groups of patients (P less than 0.05). It is concluded that classification of PBC into AMA profiles may help in identifying patients at high or low risk of progression of the disease.

Adult↗
PubMed1988

Inhibitory tagging system facilitates visual search.

Two visuospatial phenomena, serial search and inhibition of return, have recently gained the attention of scientists from such diverse disciplines as neuroscience, artificial intelligence and cognitive psychology. A linear increase in search latency with increasing display size has been assumed to reflect serial focused attention to each item in the display. A delay in the detection of a signal in a previously attended location has been assumed to reflect an inhibitory process that may be used to prevent attention from returning to the same stimulus. The following study of human performance supports these assumptions and, by demonstrating that inhibition of return operates in serial search, presumably to improve search efficiency, provides a functional link between these two phenomena.

Attention↗
PubMed1988

Aspects of the rationale for the Women's Health Trial.

A 5.5-fold range in breast cancer incidence rates in 21 countries shows strong correlation with national estimates of per capita intake of dietary fat, but not with other caloric sources (proteins and carbohydrates). It is argued that certain breast cancer and hormone factors may contribute little to the explanation of such international variations in incidence of this neoplasm. It is further argued that experimental studies in animals support a specific role for dietary fat in the promotion of mammary tumors, but the effects of calories alone seem to be largely restricted to tumor initiation. Finally, data from international, migrant-population, and analytic epidemiologic investigations are used to motivate the basic relative risk assumption of study designs thus far proposed for the Women's Health Trial, and some continuing motivations for a dietary intervention (low-fat diet) trial are discussed.

Aged↗
PubMed1988

Nucleotide sequence of cDNA clones encoding the complete precursor for the "10-kDa" polypeptide of photosystem II from spinach.

By screening lambda gt11 cDNA expression libraries prepared from poly(A+) RNA of illuminated (4 and 16 h) spinach seedlings (Spinacia oleracea var. Monatol), we have recovered phage containing inserts corresponding to the complete "10-kDa" precursor polypeptide associated with the water oxidizing photosystem II. The amino acid sequence deduced from the nucleotide sequence indicates a polypeptide of 140 amino acid residues (15.0 kDa). The mature protein is predicted to consist of 99 amino acid residues (10.8 kDa). The identity of the recombinant DNAs was established serologically and by determining an N-terminal sequence of 25 amino acid residues from the purified authentic protein. This sequence was found in the cDNA-derived amino acid sequence. In addition, a monospecific antiserum detected the appropriate polypeptides when copy-RNA was translated into protein which was imported into isolated unbroken chloroplasts. The transit sequence (41 amino acid residues; 4.2 kDa) is markedly dissimilar to those of the three extrinsic, luminal photosystem II proteins. Secondary structure prediction suggests a transmembrane arrangement of the 10-kDa polypeptide in the thylakoid membrane, with the N terminus in the thylakoid lumen and a 17-amino acid C-terminal sequence at the outside partitions. This is consistent with biochemical and functional data for the protein. A major transcript of 1.0 kilobases has been observed in polyadenylated RNA.

Amino Acid Sequence↗