Search PubMed⌕ Search

Biomedical subjects

G Rosenberg

Publications and source records attributed to G Rosenberg.

At least 19 recordsLinked to original sources
PubMed2006

A novel phospholipid derivative of indomethacin, DP-155 [mixture of 1-steroyl and 1-palmitoyl-2-{6-[1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl acetamido]hexanoyl}-sn-glycero-3-phosophatidyl [corrected] choline], shows superior safety and similar efficacy in reducing brain amyloid beta in an Alzheimer's disease model.

Indomethacin has been suggested for the treatment of Alzheimer's disease (AD), but its use is limited by gastrointestinal and renal toxicity. To overcome this limitation, D-Pharm Ltd. (Rehovot, Israel) developed DP-155 (mixture of 1-steroyl and 1-palmitoyl-2-{6-[1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl acetamido] hexanoyl}-Sn-glycero-3-phosophatidyl [corrected] choline), a lecithin derivative of indomethacin. Safety was tested by daily oral administration of DP-155 or indomethacin to rats in a dose range of 0.007 to 0.28 mmol/kg. The prevalence of gastrointestinal ulceration was significantly lower (10-fold) for DP-155 than for indomethacin, and the ulcerations were delayed. Signs of renal toxicity, namely reduced urine output and increased urine N-acetyl glycosaminidase to creatinine ratio, were 5-fold lower for DP-155. Indomethacin, but not an equimolar dose of DP-155, reduced urine bicyclo-prostaglandin E(2). An equimolar oral dose of DP-155 or indomethacin, administered every 4 h for 3 days, was equally efficacious in reducing the levels of Abeta42 in the brains of Tg2576 mice. Indomethacin was the principal metabolite of DP-155 in the serum. After DP-155 oral administration, indomethacin's half-life in the serum and the brain was 22 and 93 h, respectively, compared with 10 and 24 h following indomethacin oral administration. The brain to serum ratio was 3.5 times higher for DP-155 than indomethacin. This finding explains the efficacy of DP-155 in reducing Abeta42 brain levels, despite the low systemic blood concentrations of indomethacin derived from DP-155. In conclusion, compared with indomethacin, DP-155 has significantly lower toxicity in the gut and kidney while maintaining similar efficacy to indomethacin in lowering Abeta42 in the brains of Tg2576 mice. This superior safety profile highlights DP-155's potential as an improved indomethacin-based therapy for AD.

Alzheimer Disease↗
PubMed2001

Modifications in surgical implantation of the Penn State electric total artificial heart.

BACKGROUND: Two modifications of the surgical implantation protocol for the Penn State Total Artificial Heart (ETAH) were evaluated: Phrenic nerve ischemia was prevented by minimizing dissection and traction; and hemostasis was augmented and ETAH cuff anastomoses reinforced by using fibrin glue. METHODS: Thirteen Holstein calves underwent orthotopic surgical implantation of the Penn State ETAH between February 1998 and August 2000. Mean hemodynamic and laboratory chemistry variables from the first postoperative week were compared between calves receiving the original (n = 7) and modified (n = 6) protocol. RESULTS: Calves assigned to the modified protocol displayed an improvement in the Po2/FiO2 ratio compared to original (419.4 +/- 17.5 vs 336.3 +/- 35.4, respectively; p = 0.05). All additional parameters were equivalent between groups. The percent survival of animals receiving the modified protocol at 2, 4, and 12 weeks was higher than that of animals that underwent the original protocol. Original-protocol calf deaths consisting of hemothorax (n = 3), and respiratory failure (n = 1) were prevented in the modified protocol. CONCLUSIONS: Our results suggest that manipulations in surgical protocol may promote increased survival in calves implanted with the Penn State ETAH.

Animals↗
PubMed2001

The LionHeart LVD-2000: a completely implanted left ventricular assist device for chronic circulatory support.

Management of patients with end-stage cardiac disease remains a vexing problem. Limitations in medical management and a fixed supply of donor organs for cardiac transplant have a continued impact on this growing population of patients. Mechanical circulatory support has proved very successful as a means of bridging patients to cardiac transplant when all medical options have been exhausted. The development of a chronic system of circulatory support has been underway at the Pennsylvania State University for nearly 30 years. These efforts have been recently merged with the industrial partnership with Arrow International toward the development of the LionHeart LVD-2000 (Arrow International, Reading, PA) completely implanted left ventricular support system. We present an overview of the system, details of implantation, a review of preclinical studies, and a synopsis of the first European implants. Early results have demonstrated the system to be safe, effective, and reliable. Transcutaneous energy transmission and the compliance chamber have been validated.

Animals↗
PubMed2001

Verrucous carcinoma of the renal pelvis.

We report a case of a verrucous carcinoma of the renal pelvis after a long history of a renal pelvis stone. Only 1 case of verrucous carcinoma of the renal pelvis has been previously reported, and ours is the first case not associated with a horseshoe kidney.

Carcinoma, Verrucous↗
PubMed2001

Quality assurance of nurse triage: consistency of results over three years.

The study objective was to evaluate the capability and the consistency of the triage nurse to categorize correctly emergency patients and its impact on the waiting time for physician examination over a period of 3 years. The study was performed at the emergency department of the Barzilai Medical Center, Ashkelon, Israel. A retrospective review of the medical records was performed. All patients who were examined by a triage nurse during 2 randomly chosen consecutive weeks during the years 1995 and 1998 participated. All the medical records were reviewed by the authors and the following information was extracted from the medical records: nurse triage category, time of initial evaluation by a triage nurse, duration of employment of the nurse in the ED, and her experience as a triage nurse, time of initial examination by a physician, the total length of stay in the ED, the history taken by the triage nurse and the physician, and the physician's urgency category. Patient in urgency category 1 is a patient whose condition may deteriorate if not examined within 1 hour; patient in category 2 is a patient whose condition may deteriorate if not examined within 2 hours; category 3 is all the rest. Any deterioration and or delay of treatment of the patients were also recorded. Data concerning patients with an initial complaint of chest pain were extracted separately. The data were analyzed using the SPSS software and the results were tested by the student t test and chi square test. Interobserver agreement was measured using the kappa value. A total of 2,886 completely full medical records were reviewed by the authors: 1,310 records from period I (1995) and 1576 from period II (1998). Of the patients 92% and 88.2% were classified by the triage nurse as category 3 in periods I and II respectively, 7% and 9.8% as category 2, and 1% and 2% as category 1 respectively. Full agreement of triage category between nurse and physician was found in 90.5% of the cases in period I and 93% in period II (kappa = 0.90 and kappa = 0.93 respectively). In period I, 70% of the patients in category 1 were examined by a physician in 1 hour versus 100% in period II. Almost all the patients in category 2 were examined within 2 hours (98%, 97%), and 98% of those in category 3 were examined within 3 hours. The average waiting time for physician examination in category 1 patients dropped from 43.1 minutes in period I to 18.2 minutes in period II. The average waiting time for the triage nurse was 9 minutes in period I, and 7.42 minutes in period II. The average length of stay in the ED in period I was 1 hour and 24 minutes and 1 hour and 30 minutes in period II. Of the anamneses taken by the triage nurse 91.8% were fully identical with the physicians' anamneses, but in period II this percentage jumped to 98%. Patients with chest pain were categorized correctly by the triage nurse in 76.8% of the cases in period I and 72.4% in period II, with an overtriage of 18.6% and 20.7% respectively (kappa = 0.75, kappa = 0.70 respectively). In our study, nurse triage was safe and effective in classifying patients to urgency categories. The results are consistent and even improved over a 3-year period. The rates of incorrect classification, deterioration, and delay of treatment of patients because of incorrect triage are very low. Most of the patients were examined by the physician within the expected time. Triage nurse predicted correctly the urgency category of patients with chest in most of the cases and the rate of missing acute coronary events was very low.

Chest Pain↗
PubMed2000

Fluid dynamics of a pediatric ventricular assist device.

The number of pediatric patients requiring some form of mechanical circulatory assistance is growing throughout the world because of new surgical procedures and the success of pediatric cardiac transplantation. However, the salvage rate for those patients requiring circulatory support may be as low as 25%. Despite the fact that Penn State's 70 cc pneumatic ventricular assist device has been used with a success rate of over 90% in more than 250 patients worldwide, efforts to scale down the pump have encountered difficulties. Animal experiments with a 15 cc version were unsuccessful, with explanted pumps showing extensive thrombus deposition within the pumping chamber. The materials used to fabricate the smaller pump as well as the basic operating principles are identical to the successful adult-sized version. It is therefore believed that reducing the size of the pump altered the internal flow field, and that fluid dynamic factors were responsible for the high degree of thrombus observed with the implanted devices. A dimensional analysis was conducted that revealed significant differences in both Reynolds (Re) and Strouhal (St) numbers between the successful and unsuccessful pumps. Two component laser Doppler velocimetry was then used to characterize the internal flow field quantitatively. Comparison with data from the 70 cc pump showed a reduction in wall shear stress and turbulence levels in the 15 cc pump that would yield an environment conducive to clot formation.

Adult↗
PubMed2000

In vivo and in vitro stability of modified poly(urethaneurea) blood sacs.

In the present study, we investigate the in vivo and in vitro stability of modified poly(urethaneurea) (BioSpan MS/0.4) blood sacs. Blood sacs were utilized primarily in left ventricular assist devices that were implanted in calves for times ranging from 5 to 160 days. Cyclic testing in vitro was also conducted on similar sacs. Various analytical methods were employed to characterize the sacs after in vivo or in vitro service and corresponding retained "control" sacs. These methods included ATR-FTIR spectroscopy, scanning electron microscopy and gel permeation chromatography. In general, the characteristics of implanted and in vitro cycled sacs were similar to their control sacs. Thermal and microtensile properties were unchanged after testing. The same was true for the ATR-FTIR spectra, indicating relative chemical stability for the time frames explored here. The only significant changes occurred in molecular weight and gross surface morphology. A modest increase in weight average molecular weight was observed for most implanted blood sacs, indicating some type of chain extension or branching reaction in vivo. Although the surface morphologies of implanted blood sacs were often similar to their control sacs, we sometimes observed limited pitting on the nonblood contacting surfaces in regions of the sac that experience maximum bending during service.

Animals↗
PubMed2000

Longitudinal pathways to condom use: a psychosocial study of male IDUs.

This longitudinal study examined the psychosocial risk and protective factors involved in condom use among 265 male IDUs. Subjects were individually interviewed at two points in time using a structured questionnaire, which included psychosocial measures and questions about drug use and condom use. Data were analyzed using Pearson correlations and hierarchical regression analyses. T1 condom use was the most powerful predictor of T2 condom use, with or without control on other variables. T1 family support for condom use, friends' support for condom use, adaptive coping with AIDS or the threat of AIDS, and planning to use condoms were significantly related to T2 condom use. Protective father factors enhanced the effects of other protective psychosocial factors, increasing T2 condom use. The results suggest several approaches for changing risk-taking sexual behavior in male IDUs: enhancing coping abilities, selecting peers who take fewer risks, and planning to use condoms.

Acquired Immunodeficiency Syndrome↗
PubMed1999

An investigation of the in vivo stability of poly(ether urethaneurea) blood sacs.

In this paper we investigate the biostability of a series of Biolon blood sacs that were utilized in electric total artificial hearts for time periods of up to 19 weeks. A battery of experimental probes, including scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), were used to characterize the bulk and surface properties of explanted and control blood sacs. Gel permeation chromatography (GPC) experiments showed that generally there was a dramatic increase in average molecular weight at longer implantation times. However, SEM and GPC observations suggest significant deterioration of the flex regions of right blood sacs after 17 weeks of service. XPS experiments indicated appreciable silicon and hydrocarbon concentrations on blood-contacting surfaces both before and after implantation, and we speculate as to their origin.

Animals↗
PubMed1998

Marine latitudinal diversity gradients: tests of causal hypotheses.

Latitudinal diversity gradients are first-order expressions of diversity patterns both on land and in the oceans, although the current hypotheses that seek to explain them are based chiefly on terrestrial data. We have assembled a database of the geographic ranges of 3,916 species of marine prosobranch gastropods living on the shelves of the western Atlantic and eastern Pacific Oceans, from the tropics to the Arctic Ocean. Western Atlantic and eastern Pacific diversities are similar, and the diversity gradients are strikingly similar despite many important physical and historical differences between the oceans. This shared diversity pattern cannot be explained by: (i) latitudinal differences in species range-length (Rapoport's rule); (ii) species-area effects; or (iii) recent geologic histories. One parameter that does correlate significantly with diversity in both oceans is solar energy input, as represented by average sea surface temperature. If this correlation is causal, sea surface temperature is probably linked to diversity through some aspect of productivity. In this case, diversity is an evolutionary outcome of trophodynamic processes inherent in ecosystems, and not just a byproduct of physical geographies.

Animals↗
PubMed1998

Long-term mechanical circulatory support system reliability recommendation: American Society for Artificial Internal Organs and The Society of Thoracic Surgeons: long-term mechanical circulatory support system reliability recommendation.

Jointly developed by members of the American Society for Artificial Internal Organs and the Society of Thoracic Surgeons along with staff from the Food and Drug Administration, the National Heart, Lung and Blood Institute and other experts, this recommendation describes the reliability considerations and goals for Investigational Device Exemption and Premarket Approval submissions for long-term, mechanical circulatory support systems. The recommendation includes a definition of system failure, a discussion of an appropriate reliability model, a suggested in vitro reliability test plan, reliability considerations for animal implantation tests, in vitro and animal in vivo performance goals, the qualification of design changes during the Investigational Device Exemption clinical trial, the development of a Failure Modes Effects and Criticality Analysis, and the reliability information for surgeons and patient candidates. The document will be periodically reviewed to assess its timeliness and appropriateness within five years.

Animals↗
PubMed1998

Dynamic in vitro and in vivo performance of a permanent total artificial heart.

In vivo characterization studies were performed to compare the dynamic in vivo performance of the Penn State/3M Health Care electric total artificial heart to existing in vitro data. Fully implanted systems were utilized including the artificial heart, controller, backup batteries, compliance chamber, and transcutaneous energy transmission. Catheters were implanted to measure central venous pressure (CVP), left atrial pressure (LAP), right atrial pressure (RAP), pulmonary artery pressure (PAP), and aortic pressure (AoP). Cardiac output (CO) was determined from the implanted controller, and systemic vascular resistance (SVR) was calculated. Steady state data were collected for each animal along with data regarding the transient responses to changes in preload and afterload. Preload was manipulated through volume changes. Afterload changes were accomplished through vasoactive agents. Increased preload caused little change in cardiac output because the pump output was nearly maximum at baseline. LAP, AoP, and SVR increased with increasing RAP. Decreased preload caused a reduction in CO, LAP, and SVR. Afterload increase resulted in a slight decrease in flow and an increase in system power and SVR. Afterload reduction was accompanied by a decrease in preload and a concomitant reduction in flow. Overall, the system response was similar to the response observed in vitro.

Animals↗
PubMed1998

Social work in health care: do practitioners' writings suggest an applied social science?

There are two sources of literature in social work-one from academics and the other from practitioners. Each group is driven by different motivations to write. Academics seek a 'scientific rationality' for the field, while practitioners assume practical and intuitive reasoning, experience aligned with theory, and the 'art of practice' to guide them. It has been said that practitioners do not write and that 'faculty' are the trustees of the knowledge base of the profession, and are responsible for its promulgation via publication. Practitioners, however, do write about their practice and their programs, and analyze both, but publish much of their work in non-social work media. Their work tends not to be referenced by academic writers. One department's social workers' publications are described. We learn, from their practice writings, what concerns clinicians. Theirs is case-based learning, theoretically supported, in which the organization of services calls for their participation in multi-professional decision-making. There is the growing realization among social workers that practice wisdom and scientific technologies need to be reassessed together to find ways to enhance social work services. Clinicians' knowledge can lead to continuing refinement of practice and enhanced institutional services. If practitioners' writings can be assessed, they may lead to a written practice knowledge base, subject to timely change. Academic and practitioner separateness hampers progress in the field. They need each other, and a shared professional literature. There is beginning indication they are getting together.

Humans↗
PubMed1997

The hospital social work self-efficacy scale: a partial replication and extension.

The Hospital Social Work Self-Efficacy Scale (HSWSE) was developed to assess social workers' confidence about their ability to perform hospital social work. The scale was originally tested with master's-level social work students. This partial replication and extension included both students and professional social workers. In addition, we used a new scale to assess construct validity and added another hospital to assess external validity. In general, findings continue to support the use of the HSWSE. In addition, anecdotal evidence suggests that this is an outcome measure that practitioners see as easy to use, specific, and highly relevant.

Educational Measurement↗