Biomedical subjects

R Ron

Publications and source records attributed to R Ron.

9 recordsLinked to original sources

PubMed2004

Optimal oxygen pressure and time for reduced bubble formation in the N2-saturated decompressed prawn.

Bubbles that grow during decompression are believed to originate from preexisting gas micronuclei. We showed that pretreatment of prawns with 203 kPa oxygen before nitrogen loading reduced the number of bubbles that evolved on decompression, presumably owing to the alteration or elimination of gas micronuclei (Arieli Y, Arieli R, and Marx A. J Appl Physiol 92: 2596-2599, 2002). The present study examines the optimal pretreatment for this assumed crushing of gas micronuclei. Transparent prawns were subjected to various exposure times (0, 5, 10, 15, and 20 min) at an oxygen pressure of 203 kPa and to 5 min at different oxygen pressures (PO2 values of 101, 151, 203, 405, 608, and 810 kPa), before nitrogen loading at 203 kPa followed by explosive decompression. After the decompression, bubble density and total gas volume were measured with a light microscope equipped with a video camera. Five minutes at a PO2 of 405 kPa yielded maximal reduction of bubble density and total gas volume by 52 and 71%, respectively. It has been reported that 2-3 h of hyperbaric oxygen at bottom pressure was required to protect saturation divers decompressed on oxygen against decompression sickness. If there is a shorter pretreatment that is applicable to humans, this will be of great advantage in diving and escape from submarines.

Animals↗

PubMed2001

In vivo molecular imaging of met tyrosine kinase growth factor receptor activity in normal organs and breast tumors.

Molecular imaging techniques allow visualization of specific gene products and their physiological processes in living tissues. In this study, we present a new approach for molecular imaging of endogenous tyrosine kinase receptor activity. Met and its ligand hepatocyte growth factor scatter factor (HGF/SF), which mediate mitogenicity, tumorigenicity, and angiogenesis, were used as a model. HGF/SF and Met play a significant role in the pathogenesis and biology of a wide variety of human epithelial cancers and, therefore, may serve as potential targets for cancer prognosis and therapy. We have shown previously that in vitro activation of Met by HGF/SF increases oxygen consumption. In this study, we demonstrate that Met activation in vivo by HGF/SF alters the hemodynamics of normal and malignant Met-expressing tissues. Tumor-bearing BALB/C mice were i.v. injected with HGF/SF and imaged using magnetic resonance imaging (MRI) and Doppler ultrasound. Organs and tumors expressing high levels of Met showed the most substantial alteration in blood oxygenation levels as measured by blood oxygenation level depended (BOLD)-MRI. No significant alteration was observed in tumors or organs that does not express Met. In the liver, which expresses high levels of Met, MRI signal alteration of about 60% was observed. In the kidneys, signal alteration was approximately 30%, and no change was observed in muscles. The extent of MRI signal alteration was also in correlation with HGF/SF doses. Injection of 7 and 170 ng/g body weight resulted in signal alteration of 5% and 30%, respectively, in tumors. Doppler ultrasound measurements demonstrated that these MRI changes are at least partially attributable to altered blood flow. These hemodynamic alterations, measured by MRI and Doppler ultrasound, were used in this study for the molecular imaging of Met activity in vivo. This novel molecular imaging technique may be used for in vivo diagnosis, prognosis, and therapy of Met-expressing tumors.

Adenocarcinoma↗

PubMed1993

Quality nursing care survey, 1988-1990.

In a quality nursing care survey conducted in Israel, 1988-1990, the four nursing process components were examined. The survey covered 13 hospitals with 119 medical and surgical wards, in which the nursing care quality for a sample of 2065 patients was assessed. Instruments used were (a) the Patient Classification Form, to assess patient dependency level, and (b) Monitor--an index of the quality of nursing care for acute medical and surgical wards [Goldstone et al., Polytechnic Products, Newcastle upon Tyne, 1982], a British adaptation of the Rush Medicus methodology [Jelinek et al., US Dept of Health, Education and Welfare, 1974]. The survey process involved orientation of the hospitals' senior staff, and training of participants in the administration of patient classification and of Monitor. The highest quality nursing care was found in "Meeting the patient's physical needs"; the lowest in "Assessment and planning of patient care". Factors chosen for possible influence on quality of nursing care were: patient dependency category, type of ward (medical, surgical), ward size and hospital size. The most influential factor was found to be the patient dependency category.

Adolescent↗

PubMed1991

Planning and developing an academic curriculum in Israel.

The authors trace the development of academic curricula in nursing in Israel from the early 1960s to the present day. The foundation was laid with the first post-basic programme in 1968, and the new basic nursing degree scheme was launched at Tel Aviv University in 1989. The initial success of this project has encouraged nursing schools to pursue means of upgrading their courses from diploma to degree level.

Curriculum↗

PubMed1983