Biomedical subjects

R Benkert

Publications and source records attributed to R Benkert.

3 recordsLinked to original sources

PubMed2001

Hypertension outcomes in an urban nurse-managed center.

PURPOSE: To assess the quality of hypertension (HTN) care in an urban nurse-managed center (NMC) by chart audits of insured and uninsured (N = 52) African Americans who were managed by nurse practitioners. DATA SOURCES: A chart audit form was developed by the authors that merged Health Plan Employer Data and Information Set (HEDIS) criteria with the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) criteria. CONCLUSIONS: There was near comparable hypertension control among the two groups. No difference was found in systolic blood pressure (BP) control; however, the uninsured group had a slightly greater average diastolic BP compared with the insured group. There was no significant difference in the number of HTN medications or the number of risk factors. A significant difference was found in the number of NP visits per year between the two groups; the uninsured group averaged 3.2 more visits per year. IMPLICATIONS FOR PRACTICE: Nurse practitioners in this NMC were able to manage HTN in a high-risk population despite a lack of insurance coverage for anti-hypertensive prescriptions. The finding that the uninsured group had more clinic visits per year than the insured group is significant in that it increases the cost of providing care for these patients and the health care system. The patient cost in time, transportation and burden needs further assessment.

Antihypertensive Agents↗

PubMed1998

Electrorotation of isolated generative and vegetative cells, and of intact pollen grains of Lilium longiflorum.

The dielectric structure of mature pollen of the angiosperm Lilium longiflorum was studied by means of single-cell electrorotation. The use of a microstructured four-electrode chamber allowed the measurements to be performed over a wide range of medium conductivity from 3 to 500 mS m-1. The rotation spectra of hydrated pollen grains exhibited at least three well-resolved peaks in the kHz-MHz frequency range, which obviously arise due to the multilayered structure of pollen grains. The three-shell model can explain the complex rotational behavior of pollen grains in terms of conductivities, permittivities and thicknesses of the following compartments: the exine and intine of the pollen grain wall as well as the membrane and cytoplasm of the vegetative cell. However, the number of unknown parameters (more than 8) was too large to allow unambiguous values to be assigned to any of them. Therefore, to facilitate the evaluation of the pollen grain parameters, additional rotational measurements were made on isolated vegetative and generative cells. The rotation spectra of these cells could be fitted very accurately on the basis of the single-shell model by assuming a dispersion of the cytoplasm. The data on the membrane and cytoplasmic properties of isolated vegetative cells were then used for modeling the rotation spectra of pollen grains. This greatly facilitated the fitting of the theoretical model to the experimental data and allowed the dielectric properties of the major structural units to be determined. The dielectric characterization of pollen is of enormous interest for plant biotechnology, where pollen and isolated germ cells are successfully used for production of transgenic crop and drug plants of economic importance by means of electromanipulation techniques.

Electric Conductivity↗

PubMed1995

Quantitative NMR microscopy on intact plants.

Quantitative high resolution images on intact young maize plants were acquired by using magnetization-prepared NMR microscopy. Although the spatial resolution is low compared with that of light microscopy, the calculated spin density and T1 maps exhibit contrasts that are in excellent agreement with photomicrographic images. The T2 map gives image contrasts that are not visible in a usual light microscopic image. The diffusion images show an anisotropic behavior of the water self-diffusion coefficient in the vascular bundles, which can be understood by the cell morphology in this plant section. This work demonstrates that quantitative imaging on intact plant systems is possible and that long total acquisition times are no obstacle. Furthermore, the different single parameter maps give a better insight into the morphology of plants under in vivo conditions.

Magnetic Resonance Spectroscopy↗