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Biomedical subjects

C E Barr

Publications and source records attributed to C E Barr.

At least 55 records · Page 3Linked to original sources
PubMed1969

Localization of hydrogen ion and chloride ion fluxes in Nitella.

Alternating bands of acid and base formation have been detected along the length of the internodal cell of Nitella clavata when it is illuminated, while in the dark this phenomenon is minimal. Chloride influx occurs only or largely in the acid-extruding regions, and this is also a light-dependent ion movement. Chloride efflux is slightly dependent on illumination and is not localized as are H(+) efflux and Cl(-) influx. The results obtained support Kitasato's (1968) proposal that a large passive H(+) influx is balanced by an active efflux of this ion. Transport mechanisms suggested by the correlations of Cl(-) and HCO(3) (-) influxes with H(+) extrusion are discussed.

Biological Transport↗
PubMed1966

Energy balancing in Nitella cells treated with dinitrophenol.

The toxic action of 2,4-dinitrophenol on the large cells of the alga, Nitella clavata, was evaluated, with the rate of protoplasmic streaming and the survival time at three light intensities used as criteria. At a sufficiently high intensity the cells survived several weeks, an indication that the energy-uncoupling action of dinitrophenol could be counterbalanced to some extent by an increased energy input. In the treated cells chloroplasts moved from the outer gel-type cytoplasm into the inner, streaming cytoplasm.

Chloroplasts↗
PubMedDate not supplied

Dental care for HIV-positive patients.

This case-controlled study compared the types of routine dental services provided to an HIV-infected group with those provided to an HIV-negative cohort. No statistical differences in requesting dental treatment (routine or emergency) or in the types of dental treatment provided to the two groups were reported, except in the provision of prosthetic dentistry and the development of a comprehensive treatment plan.

Adult↗
PubMedDate not supplied

Clinical and radiographic presentations of HIV-1 necrotizing ulcerative periodontitis.

HIV-1-associated periodontal diseases have been reported in the literature for several years. Criteria for the diagnosis of these diseases have not been universally accepted, although there are numerous papers describing the clinical entity. These case reports provide clinical and radiographic evidence of a type of periodontal disease with bone and soft tissue destruction which differentiates it from "conventional" periodontal diseases found in both HIV-1-infected patients and those not infected by the virus. It is important, from both diagnostic and therapeutic aspects, for clinicians to be able to make this distinction. The appropriate use of clinical and radiographic findings is extremely helpful in the diagnosis, particularly in the case of defining HIV-1 necrotizing ulcerative periodontitis (NUP). Whether the patterns of gingival changes and bone loss described in these case reports are specific to HIV-1-seropositive persons or rather represent severe immunosuppression requires further investigation.

AIDS-Related Opportunistic Infections↗