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Biomedical subjects

A Shahar

Publications and source records attributed to A Shahar.

At least 19 recordsLinked to original sources
PubMed2005

Development of a tissue-engineered composite implant for treating traumatic paraplegia in rats.

This study was designed to assess a new composite implant to induce regeneration of injured spinal cord in paraplegic rats following complete cord transection. Neuronal xenogeneic cells from biopsies of adult nasal olfactory mucosa (NOM) of human origin, or spinal cords of human embryos, were cultured in two consecutive stages: stationary cultures in a viscous semi-solid gel (NVR-N-Gel) and in suspension on positively charged microcarriers (MCs). A tissue-engineered tubular scaffold, containing bundles of parallel nanofibers, was developed. Both the tube and the nanofibers were made of a biodegradable dextran sulphate-gelatin co-precipitate. The suturable scaffold anchored the implant at the site of injury and provided guidance for the regenerating axons. Implants of adult human NOM cells were implanted into eight rats, from which a 4 mm segment of the spinal cord had been completely removed. Another four rats whose spinal cords had also been transected were implanted with a composite implant of cultured human embryonic spinal cord cells. Eight other cord-transected rats served as a control group. Physiological and behavioral analysis, performed 3 months after implantation, revealed partial recovery of function in one or two limbs in three out of eight animals of the NOM implanted group and in all the four rats that were implanted with cultured human embryonic spinal cord cells. Animals of the control group remained completely paralyzed and did not show transmission of stimuli to the brain. The utilization of an innovative composite implant to bridge a gap resulting from the transection and removal of a 4 mm spinal cord segment shows promise, suggesting the feasibility of this approach for partial reconstruction of spinal cord lesions. Such an implant may serve as a vital bridging station in acute and chronic cases of paraplegia.

Animals↗
PubMed2001

Seasonal variations in dietary intake affect the consistency of dietary assessment.

BACKGROUND: Nutritional epidemiology studies are usually based on one dietary assessment without taking into account the season in which the interview is taken or adjusting for the difference in reporting dietary intake in different seasons. The semiquantitative food frequency questionnaire has become the primary questionnaire method for measuring dietary intake in epidemiological studies. The aims of this report were (a) to evaluate the effect of season on dietary intake as measured by a semiquantitative food frequency questionnaire (FFQ) conducted twice: once in summer and a second time in winter; and (b) to assess the effect of the differences in dietary intake on biochemical and anthropometric seasonal related changes, such as serum cholesterol and body mass index (BMI). POPULATION AND METHODS: The study population consisted of 94 male industrial employees who participated in clinical biochemical and physical examinations as well as evaluation of their dietary intake twice a year. Dietary intake was assessed using the semiquantitative FFQ that included 96 items and was conducted by a personal interview. RESULTS: We found a significant increase in the intake of selected nutrients in winter as compared to summer as well as an increased intake of animal fat-containing foods such as meat and dairy products. Significant correlation coefficients were shown between the increase in dietary intake of saturated fat and the increase in BMI, serum total and LDL cholesterol. The increase in dietary cholesterol was significantly and positively correlated with the increase in serum total and LDL cholesterol. CONCLUSION: Although FFQ are designed to assess average yearly food intake, we identified significant seasonal changes in dietary intake as measured by FFQ. These changes have a health impact on our population.

Adult↗
PubMed2001

The effect of widowhood on weight change, dietary intake, and eating behavior in the elderly population.

OBJECTIVES: To assess the effect of recent widowhood on weight, dietary intake, and habits. METHODS: Participants included 58 recently widowed elderly subjects and 58 married subjects who were matched on age, sex, and race. Weight change from baseline and following widowhood, dietary intake, eating behavior, depression, and cognitive and physical functioning were assessed in a clinic interview. RESULTS: Mean weight loss and the prevalence of weight loss were significantly higher among widowed participants. They ate more meals alone, more commercial meals per week, and fewer snacks and homemade meals. They also enjoyed their eating less. A significant difference between cases and controls was evident after adjusting for all the variables. Higher cognitive functioning score, younger age, and better appetite were protective against weight loss. DISCUSSION: Widowed people were found to be at increased risk for weight loss. This may well be due to decreased appetite and enjoyment of their meals.

Adaptation, Psychological↗
PubMed2001

High prevalence and impact of subnormal serum vitamin B12 levels in Israeli elders admitted to a geriatric hospital.

BACKGROUND: The elderly are known to have higher rates of low and subnormal vitamin B12 levels than younger persons. Vitamin B12 deficiency has been extensively studied in the elderly, but primarily in outpatient settings. There is a paucity of data regarding the prevalence of low and low-normal B12 in frail, hospitalized, elderly patients, and its implications. Additionally, there is little information regarding vitamin B12 status in Israeli elders. OBJECTIVES: The objectives of the study were to estimate the prevalence of low and borderline vitamin B12 levels among frail, hospitalized, elderly patients, and their clinical implications. METHODS: We conducted a chart review, using a retrospective cohort design. The participants were 895 patients admitted to Harzfeld Medical Center in Gedera, Israel. Records were abstracted for vitamin B12 and Folic Acid levels, gastric disease, and outcomes including death, cognitive impairment and neurologic disease. RESULTS: Six hundred and forty patients were eligible for the study. In 15% of the patients, vitamin B12 level was in the low range (<150pmol/L) and in 25% in the low-normal range (150-250pmol/L). Gastric disease and antacid use were not associated with the vitamin B12 status. Mortality was higher in the high vitamin B12 group (p=0.02), perhaps reflecting a selection toward higher acuity in this group. Cerebrovascular disease was more common in patients with lower vitamin B12 levels (p=0.046). CONCLUSIONS: Forty percent of hospitalized elderly patients have low or borderline serum levels of vitamin B12, which may contribute to cerebrovascular disease and cognitive decline.

Aged↗
PubMed2000

An international training program to assist with establishing emergency medicine in Ethiopia.

Ethiopia has a population of 56 million and an area of 1,110,000 km(2). Ethiopia is one of the poorest nations in the world, and its health services system reflects that poverty. Accidental injury, violence, infectious diseases, and natural and manmade disasters abound, yet emergency medicine is practically nonexistent. Poorly equipped and staff emergency "rooms" supply substandard service even in the capital. Significant work and planning are under way by a group of high-quality and dedicated local physicians and nurses with international support from Israel and the United States. A coherent plan is due at the end of the year. Much financial and professional support from outside sources will be required for significant advances in the quality of emergency care to improve. Human as well are material resources are vital.

Curriculum↗
PubMed2000

[Hospitalization for renal colic in the emergency room of a large central hospital in Israel: epidemiological features and clinical manifestations].

The medical records of all patients referred to the emergency department (ED) of Sheba Medical Center for renal colic during 1996 were analyzed. Patients discharged from the ED and those hospitalized were compared. There was no significant difference between the 2 groups with regard to average age or sex distribution. Statistically significant differences were found with regard to frequency of chills and fever, history of renal colic, referral for renal colic during that year or hospitalization for renal colic or nephrolithiasis, previous positive imaging, stone removal by surgery or extracorporeal shock wave lithotripsy, fever exceeding 37.5 degrees and administration of fluids, pethidine or pramin in the ED, prolonged stay in the ED and previous appendectomy. A conditional regression model tested the predictive value of each of those factors. Inclusion of independent variables into the model led to an overall correct classification rate of 84.43%, with 44.83% sensitivity and 93.16% specificity. There were correlations between referrals for renal colic, overall renal colic rate and average monthly temperature, so there was no pure correlation between average monthly temperature and referrals to the ED for renal colic. The major indications for hospitalization were actually the clinical ones, indicating either an active metabolic disease or suspected obstruction of the urinary tract. Treatment in the ED and duration of the visit indicated disease severity.

Adult↗
PubMed1999

Survival without surgical repair of acute rupture of the right ventricular free wall.

Rupture of the myocardial free wall is an infrequent complication of acute myocardial infarction. Unless it occurs in a space confined by pericardial adhesions, only surgical emergency repair of ruptured myocardium can prevent death. In this paper we report the case of an 81-year-old woman who was admitted to the emergency room with cardiac tamponade, resulting from inferolateral acute myocardial infarction and a subsequent rupture of the right ventricular free wall, with the formation of pericardial thrombus and effusion. The patient refused to undergo any surgical or invasive intervention, and therefore she was only treated conservatively. Nevertheless, her condition improved dramatically, as her blood pressure increased and echocardiography abnormalities almost disappeared. Follow-up echocardiography 7 months post discharge was unremarkable. We believe that this rare case emphasizes that in special circumstances, such as creation of a thrombus that prevents more blood from extravasating, free-wall rupture without surgical repair is compatible with long-term survival.

Aged↗
PubMed1999

Endothelial trophic support of neuronal production and recruitment from the adult mammalian subependyma.

Vascular endothelial cells are among the first cells that ventricular zone neuroblasts encounter during early development. The ventricular zone cells promote angiogenesis by the invading vasculature, with the release of endothelial mitogens. Yet the feedback support of young neurons by endothelial cells (ECs) has not hitherto been explored. We therefore asked whether ECs might participate in neuronal recruitment, by providing neurotrophic support to newly generated neurons. We used the neurogenic subependymal zone (SZ) of the adult rat forebrain as a model system, because of its well-characterized and relatively homogeneous population of neuronal precursor cells. We found that explants of the adult rat SZ raised on ECs generated more neurons, which survived longer, than explants raised on astrocytes, fibroblasts, or laminin. This endothelial trophic effect was humoral, in that it was also noted in SZ explants raised in noncontiguous coculture with ECs grown on porous inserts. RT-PCR for neurotrophin family members revealed that cultures of both human brain- and umbilical cord-derived ECs produced brain-derived neurotrophic factor (BDNF) mRNA, but no detectable NGF, NT-3, or NT-4 mRNA. ELISA revealed that BDNF protein was secreted by ECs into the medium at >1 ng/ml. The neurotrophic effect of ECs could be replaced by added BDNF, and was blocked by addition of 5 microg/ml trkB-Fc to endothelial-SZ cocultures. Thus, endothelial cells can act as sources of secreted BDNF, through which the capillary microvasculature may act to support neuronal recruitment and survival in the CNS.

Animals↗
PubMed1999

Patients with stages III and IV endometriosis have a poorer outcome of in vitro fertilization-embryo transfer than patients with tubal infertility.

OBJECTIVE: To evaluate the outcome of IVF in patients with stages III and IV endometriosis. DESIGN: Retrospective study. SETTING: The Sara Racine IVF Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Israel. PATIENT(S): Fifty-eight patients with stages III and IV endometriosis and 60 patients with tubal infertility. INTERVENTION(S): IVF-ET for all couples. MAIN OUTCOME MEASURE(S): Fertilization, pregnancy, and birth rates. RESULT(S): The comparison between patients with endometriosis and those with tubal infertility indicated that the former had a poor IVF outcome in terms of reduced fertilization rate (40% vs. 70%), reduced pregnancy rate per cycle (10.6% vs. 22.4%), and reduced birth rate per cycle (6.7% vs. 16.6%). The differences were statistically significant. CONCLUSION(S): The results show an unfavorable outcome of IVF-ET in patients with endometriosis when compared with those who have tubal infertility.

Adult↗
PubMed1999

A single nucleotide change in the 5' noncoding region of Sindbis virus confers neurovirulence in rats.

Two pairs of Sindbis virus (SV) variants that differ in their neuroinvasive and neurovirulent traits in mice have been isolated. Recently, we mapped the genetic determinants responsible for neuroinvasiveness in weanling mice. Here, we extend this study to newborn and adult rats and to rat neuronal cultures. Remarkably, certain aspects of the pathogenesis of these strains in rats were found to be quite distinct from the mouse model. Suckling rats were susceptible to all four isolates, and replication in the brain was observed after both intraperitoneal and intracranial (i.c.) inoculation. None of the isolates was neuroinvasive in adult rats, although all replicated after i.c. inoculation. For the isolate pair that was highly neurovirulent in mice, SVN and SVNI, only SVNI caused death after i.c. inoculation of adult rats. Similarly, only SVNI was cytotoxic for primary cultures of mature neurons. The genetic determinants responsible for the pathogenic properties of SVNI were mapped to the E2 glycoprotein and the 5' noncoding region (5'NCR). Substitution of two amino acids in SVN E2 with the corresponding residues of SVNI (Met-190 and Lys-260) led to paralysis in 3- and 5-week-old rats. More dramatically, a single substitution in the 5'NCR of SVN (G at position 8) transformed the virus into a lethal pathogen for 3-week-old rats like SVNI. In 5-week-old rats, however, this recombinant was attenuated relative to SVNI by 2 orders of magnitude. Combination of the E2 and 5'NCR determinants resulted in a recombinant with virulence properties indistinguishable from those of SVNI. These data indicate that the 5'NCR and E2 play an instrumental role in determining the age-dependent pathogenic properties of SV in rats.

5' Untranslated Regions↗
PubMed1999

CEBQ: Composite Eating Behavior Questionnaire--development and performance.

Poor eating behavior is an important nutritional risk factor among community dwelling elders, and precedes overt malnutrition in the majority of cases. Several tools were developed to assess nutritional risk through evaluating eating behavior. All containing elements shown to be related to nutritional decline. Given the diversity of the geriatric population each tool may apply to specific subsets of the population but not to all. The ideal tool may be a questionnaire tailored for the study population based on a pool of methods and questions. We describe the development and use of such a composite tool, and compares its performance to other questionnaires. Our results show that in community dwelling elders nutrition risk assessments such as the NRI or eating behavior score were not predictive of nutritional status measured by dietary intake, weight change or BMI. Subjective appetite assessment was the most predictive question for nutritional decline. We describe the questionnaire and its development and offer general advice to its future implementations.

Aged↗
PubMed1998

Xiphodynia masking acute myocardial infarction: a diagnostic cul-de-sac.

A 52-year-old hypertensive woman is described in whom a clinically evident diagnosis of xiphodynia, the painful xiphoid process, complicated the diagnosis of impending myocardial infarction. The authors suggest that xiphodynia be considered a second-line assumption after more dangerous conditions have been thoroughly ruled out.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

[Angioedema caused by splenectomy with malignant lymphoma followed by multiple myeloma 7 years later].

Acquired C1-inhibitor (C1-INH) deficiency has been reported in patients with immunoglobulin abnormalities and lymphoproliferative disorders, and angioedema has appeared simultaneously with the lymphoproliferative disease. We present a 50-year-old woman with acquired C1-INH deficiency and angioedema which preceded by 7 years the diagnosis of malignant mantle cell lymphoma. During the interval she was treated with Danazole and there were no attacks of angioedema. When routine follow-up bone marrow aspiration revealed infiltration of nonspecified lymphoma cells, exploratory laparotomy and splenectomy were performed. A month later Danazol was stopped, C1-INH levels returned to normal and there were no attacks of angioedema. Mantle cell lymphoma consisting of lymphocytes with cytoplasmic IgM-lambda was diagnosed in the excised spleen but chemotherapy was not initiated. 6 months later, a second lymphoproliferative disorder, multiple myeloma IgA kappa, was diagnosed.

Angioedema↗