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Biomedical subjects

R Klein

Publications and source records attributed to R Klein.

At least 829 records · Page 46Linked to original sources
PubMed1980

Fluorophotometry. II. Streptozocin-treated guinea pigs.

Normal and streptozocin-treated guinea pigs were examined with a fluorophotometer one hour after receiving an intravenous injection of fluorescein sodium. The level of fluorescence in the vitreous was significantly greater in animals showing marked glucosuria than in normal animals or those showing little glucosuria. The excessive fluorescence of the vitreous is similar to that reported by others in diabetic humans and rats but is found in the guinea pig, an animal known normally to have no retinal vasculature.

Animals↗
PubMed1980

Fluorophotometry. III. Streptozocin-treated rats and rats with pancreatectomy.

To determine whether elevated vitreous fluorescence levels are a result of a direct ocular toxic effect of streptozocin or a consequence of the diabetic state, we compared hyperglycemic streptozocin- and insulin-treated or non-insulin-treated rats, hyperglycemia rats with pancreatectomy, and normal rats. Streptozocin, 65 mg/kg, was injected intravenously in one group of hooded rats, and pancreatectomy was performed on another group of hooded rats. Eight to 16 days later, fluorescein sodium, 16.6 mg/kg, was injected in the femoral vein of 21 hyperglycemic rats and 18 normal animals. One hour later, the aqueous, vitreous, and plasma fluorescence levels were measured using fluorophotometry. We did not find a significant difference between vitreous fluorescence levels of the hyperglycemic streptozocin- and insulin-treated or non-insulin-treated and normal rats. Moreover, we did not find a significant difference between the vitreous fluorescence of hyperglycemic rats with pancreatectomy and normal rats.

Animals↗
PubMed1980

Insertion of muntjac gene segment into hamster cells by cell fusion.

Indian muntjac diploid cells that have only three pairs of easily discernible large chromosomes were fused with hamster cells deficient in hypoxanthine guanine phosphoribosyltransferase (HGPRT) using polyethylene glycol. Cells that survived in hypoxanthine-aminopterine-thymidine (HAT)-oubaine medium were analyzed. Hybrid cells containing both muntjac and hamster chromosomes in a given cell were not found. Instead, the cells had the same chromosomal sets as those of either parental muntjac or hamster cells. A clonal isolate that had the same chromosomal sets as those of parental hamster cells were analyzed in detail and showed the following characteristics: (1) portions of the survival curve in various concentrations of HAT medium were intermediate between those of parental cells; (2) expressions of both muntjac and hamster antigen(s) were detected by immunofluorescence staining; (3) the mobility of the enzyme HGPRT in gel electrophoresis differed from that of parental hamster or muntjac cells. These results indicate that the clonal isolate (AD202h) is a somatic cell hybrid of hamster and muntjac that contains chromosomal sets of hamster with an inserted segment of the muntjac genome, including HGPRT. The formation of such an unusual hybrid and a possible explanation of transfer of some gene segments in the hybrid cell in this system are discussed.

Animals↗
PubMed1980

Diabetic papillopathy.

A 13-year-old girl and a 20-year-old man with juvenile-onset diabetes mellitus developed transient bilateral optic disk edema with minimal impairment of optic nerve function and with minimal diabetic retinopathy. This conditions, termed diabetic papillopathy appears to be a local optic disk vasculopathy, and generally resolves without treatment. Diabetic papillopathy should not be mistaken for papilledema or for the optic disk neovascularization of diabetic retinopathy.

Adolescent↗
PubMed1980

Formation of N-nitroso compounds of the pesticides atrazine, simazine and carbaryl with nitrogen oxides.

The nitrosation of atrazine, simazine and carbaryl by nitrogen oxides was investigated in model experiments. Pure pesticides and their corresponding formulations were exposed, as dry powders and as aqueous suspensions, to defined concentrations of NOx (1000, 100, 10 and 1 ppm) in a reaction chamber. Nitrosated pesticides were determined by HPLC-TEA. Generally, the amount of nitrosation increased with the reaction time. At high NOx concentrations (1000 and 100 ppm), nitrosation approached saturation. For atrazine and simazine, further reaction with nitrogen oxides might occur. Nitrosation rates of dry powdered pesticides were inversely proportional to grain size and to air moisture content. Nitrosation of aqueous pesticide suspensions by nitrogen oxides was strongly inhibited at pH values higher than 5.

Atrazine↗
PubMed1980

Models of man and models of policy: reflections of "Exit, Voice, and Loyalty" ten years later.

The challenge of health care policy is how to combine sensitivity to both consumer preferences (the economic model) and citizen wishes (the political model): what either wants the other may wish to deny him. Competing economic (exit) and political (voice) activities in response to deterioration in the quality of a service, however, may be an inadequate framework to encompass discontent with the complex mix of types of services offered. The "political market" in which decisions about health care are made is suggested for further exploration.

Community Participation↗
PubMed1980

Post-traumatic bronchial stenosis and acute respiratory insufficiency.

A 31-year-old woman sustained multiple injuries, including severe contusion of the right lung with massive subcutaneous emphysema. Four weeks later she was transferred to our institution with post-traumatic adult respiratory distress syndrome and carbon dioxide retention, resulting from a postlaceration stenosis of the left main-stem bronchus. Bronchoplasty was contraindicated because of the serious condition of the patient. Repeated bronchial dilatations produced initial improvement in oxygenation and minute ventilation requirements. However, because of the nature of the stenosis and the lack of recovery of right lung function, the patient's encouraging clinical course reached a plateau and attempts at weaning from the respirator were unsuccessful. Bronchoplasty was performed on postadmission day 50 and resulted in gradual recovery of pulmonary function. Six months following discharge, the patient continues a steady improvement. Management of the patient's injuries represented a unique challenge previously unencountered.

Adult↗
PubMed1979

Health insurance in America: a vision of health in the world's richest nation.

Alone among industrialised countries, the USA does not have a comprehensive national health insurance system. There are some federal and state schemes, but for most people the choice is between hefty private insurance premiums or no coverage at all. Now the establishment of an effective NHI has become a key issue in the presidential campaign, says Reva Klein.

National Health Insurance, United States↗
PubMed1979

Tumorigenicity of Indian muntjac diploid cells by the proviral integration of sarcoma gene of a mouse retrovirus.

The transformed clonal isolates of Indian muntjac diploid cells by a mouse sarcoma virus, 43-2XV, were tested for tumorigenicity in athymic nude mice. In spite of the indistinguishable transformed morphology, the tumorigenicity exhibited four different patterns: (a) no tumor formation; (b) slowly growing regressive tumor formation; (c) rapidly growing regressive tumor formation; and (d) rapidly growing progressive tumor formation. This demonstrates that the same diploid host cells transformed by the same virus reveal variable patterns of tumorigenic expression and some transformed host cells lack the tumorigenicity entirely. The findings that there are at least two chromosomes and four recombinant sites assigned for the proviral integrations of the sarcoma gene into the Indian muntjac gene (M. Hatanaka, R. Klein, R. Kominami, T. Oikawa, H. Okabe, N. Tsuchida, E. C. Connors, and A. Carrano. Transformation of Indian muntjac diploid cells by the proviral integration of sarcoma gene of a mouse retrovirus. Manuscript in preparation.) lead us to propose a hypothesis that variable expressions of tumorigenicity under the neutral background of immune responses, may arise from variable integrations of the sarcoma gene into the host chromosome.

Animals↗
PubMed1979

Rhythms in human performance: 1 1/2-hour oscillations in cognitive style.

Performance on verbal and spatial matching tasks was assessed every 15 minutes for 8 hours. Significant 60- to 100-minute oscillations were observed for each task. These oscillations were 180 degrees out of phase, supporting the hypothesis that in humans the basic rest activity cycle involves alternating activation of processing systems residing in the two cerebral hemispheres.

Behavior↗
PubMed1979

Carcinogenic N-nitrosodimethylamine as a contamination in drugs containing 4-dimethylamino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (amidopyrine, aminophenazone).

A total of 68 commercially available drugs containing amidopyrine were investigated for contamination with the strong carcinogen N-nitrosodimethylamine (NDMA). All samples contained varying amounts of NDMA. About half of the drugs contained 1--10 micrograms/kg, 40% contained 11--50 micrograms/kg, 7% contained 51--10 micrograms/kg and one sample had 370 micrograms/kg. NDMA-contents in batches of pure amidopyrine that had been utilized for preparation of drugs were higher than those in the respective drugs: about one-third was in the range of 20--50 micrograms/kg, one-third had 51--100 micrograms/kg, and one-third was above 100 micrograms/kg. There was, however, no correlation between NDMA-contents of batches of the pure substance and NDMA-contents of the drugs prepared from these batched. NDMA concentrations in the samples were inhomogenously distributed. It could be demonstrated that amidopyrine in substance reacts extremely rapidly with nitrogen oxides from the air to form NDMA. Ascorbic acid, which prevents nitrosamine formation in aqueous-acidic solution, under these conditions had no protective effect.

Aminopyrine↗
PubMed1979

Ideology, class and the National Health Service.

Since the start of the British National Health Service, disputes between the government and the medical profession have become formalized battles with well-recognized rules. But between 1974 and 1976 the consensus underlying the conflict was challenged by the Labour Government's policy on private practice and pay beds. This paper examines the course of the conflict and analyzes the factors underlying the eruption of this issue. It draws attention to the role of the trade-unions in activating the Labour Party's latent ideological commitment on private practice. Although the issue appears to conform to a class-conflict model, this simple symmetry becomes blurred on closer analysis. In conclusion the paper argues that while socio-structural factors extrinsic to the health service explain the appearance of private practice on the political agenda, it is factors endogenous to the NHS which explain the outcome of the dispute. In turn, however, these endogenous factors have little to do with the fact that the NHS is delivering a commodity called "health." Instead, what is important is that the NHS is a complex organization and, as such, depends on the co-operation of a variety of groups--ranging from the medical profession to laundry workers. The analysis, therefore, concludes that the power of the medical profession derives not from its elite status but from its position as an organized group in a complex industry.

Beds↗