PubMed Health⌕ Search

Biomedical subjects

A Ben-David

Publications and source records attributed to A Ben-David.

At least 19 recordsLinked to original sources
PubMed2002

Antibody responses and morbidity following infection with infectious bronchitis virus and challenge with Escherichia coli, in lines divergently selected on antibody response.

We evaluated the association between antibody (Ab) production and disease resistance. A controlled-challenge protocol was developed to mimic natural infection and to yield a higher rate of mortality following Escherichia coli (EC) challenge. Chicks were first infected with infectious bronchitis virus (IBV) by injecting a high dose of vaccine (attenuated virus) into their air sacs and then were infected with pathogenic EC introduced intratracheally. The experimental population consisted of lines divergently selected for high (HH) or low (LL) Ab response to EC vaccination, an HH x LL cross (HL), and commercial broilers (CC). When chicks were vaccinated with EC vaccine, mean Ab titer 15 d post-EC challenge was threefold higher in HH than LL lines, but both lines exhibited very low mortality (approximately 2%). When chicks were not vaccinated prior to EC challenge, high mortality (8 to 20%) occurred in the slow-growing HH, LL, and HL lines, and much higher mortality (approximately 40%) occurred among the CC broilers that were 38% heavier than the HH, LL, and HL lines. Mean level of Ab to EC, 7 d after EC challenge, was about twofold higher in HH vs. LL chicks and intermediate in HL and CC chicks. Within each line, Ab levels were higher in chicks exhibiting colibacillosis than in healthy ones, suggesting that these Ab were produced as a result of ongoing infection but were too late to fully prevent morbidity and mortality. These results indicate that rapid growth rate substantially reduces broiler viability, whereas Ab levels produced in response to acute pathogenic challenge without prior vaccination do not contribute to disease resistance. Among the relatively slow-growing lines, mortality was about twofold higher in HH than in LL lines. This finding may confirm previous reports that without prior vaccination, high Ab response to acute challenge increases consequent mortality; alternatively, the LL line may be superior in nonspecific defense mechanisms.

Animals↗
PubMed2002

Genetic and phenotypic correlations between antibody responses to Escherichia coli, infectious bursa disease virus (IBDV), and Newcastle disease virus (NDV), in broiler lines selected on antibody response to Escherichia coli.

The genetic control of antibody (Ab) response to Escherichia coli (EC), infectious bursa disease virus, and Newcastle disease virus and the genetic and phenotypic correlation between these Ab responses, were evaluated under farm conditions in which chicks were simultaneously exposed to these antigens. The experimental population comprised five groups: two lines divergently selected for high (HH) or low (LL) Ab response to EC vaccination; a commercial broiler dam-line (CC), from which HH and LL had been derived; and the HH x CC and LL x CC hybrid groups (HC and LC, respectively). Lines LL and HH expressed similar symmetric divergence to all three antigens. The ranking of the LL, LC, CC, HC, and HH genetic groups according to their mean Ab responses and their very high linear correlation with the LL vs. HH genomic scale clearly indicate the additive nature of the genetic divergence between these lines. Several estimates of correlation were calculated between Ab responses of each pair of antigens and between BW and Ab to each antigen. The high correlation between group means, the near-zero within-group correlation, and the low phenotypic correlation indicate the strongly positive genetic correlation between Ab responses and no correlation with BW. The results of this study suggest that overall immunocompetence of commercial broilers can be improved by selection for high Ab response of young chicks to controlled immunization with a single antigen, without counteracting further selection for high BW.

Animals↗
PubMed2000

CT findings in ten patients with failed renal allografts: comparison with findings in functional grafts.

Our aim is to report the computed tomography (CT) features of the long-term failed renal allograft. Ten patients with failed renal transplants in whom the graft was left in situ underwent CT for various unrelated indications. The majority of the failed grafts showed marked shrinkage and coarse punctate diffuse parenchymal calcifications. Small cysts were seen in four grafts. A long-term failed renal transplant appeared on CT as a small rounded soft tissue mass. The graft was almost always heavily calcified. Lack of awareness of the nature of such a mass may mislead the radiologist in interpreting it as a space-occupying lesion.

Adult↗
PubMed2000

Immunocompetence and viability under commercial conditions of broiler groups differing in growth rate and in antibody response to Escherichia coil vaccine.

Mortality and morbidity due to infectious diseases are an increasing source of losses to the broiler industry. Breeding chickens for improved disease resistance may reduce these losses. A study was designed to evaluate the contribution of selection for immune response to viability of broilers under farm conditions. The experimental populations consisted of six groups: two lines divergently selected for high (HH) or low (LL) antibody (Ab) response to Escherichia coli vaccination; commercial broilers (CC); and the HH x CC, LL x CC, and HH x LL crosses. Chicks were tested under standard vaccination program and management on commercial farms in two years (1997 and 1998). Mortality was recorded in the whole groups, each consisting of several hundred or thousand of chicks, whereas BW and Ab to natural exposure to E. coli and to vaccination with Newcastle disease virus (NDV) were determined in samples of 50 to 120 chicks/group per yr. Groups were clustered into three levels of BW: CC representing contemporary fast-growing broilers; HH, LL, and HL representing broilers 10 yr earlier; and HC and LC with intermediate BW. The HH and LL groups exhibited the highest and lowest E. coli Ab titers, respectively. Mean Ab of the CC group equaled the average of the selected lines, and all crosses exhibited mid-parent Ab titers, indicating additive genetic control. Group means for Ab to NDV were highly correlated with those of E. coli, suggesting a common genetic control for the immune response to these two antigens. In both years, the highest mortality was found in the fast-growing group (CC), and the lowest mortality was in the slow-growing HH, LL, and HL groups. In the crosses, despite their similar mean BW, mortality was one-third higher among LC vs. HC birds. These results suggest that Ab response and potential growth rate interact in their effect on mortality due to infectious diseases.

Animals↗
PubMed1999

Anti-cardiolipin, anti-endothelial-cell and anti-malondialdehyde-LDL antibodies in uremic patients undergoing hemodialysis: relationship with vascular access thrombosis and thromboembolic events.

Patients with chronic renal failure requiring regular hemodialysis are known to be prone to thromboembolic events due to a hypercoagulable state. Vascular access thrombosis (VAT; including thrombosis of the vascular shunt or graft) represents a serious complication and jeopardizes life in these patients. In the current study, conducted on 81 consecutive patients from the Hemodialysis Unit, we have employed ELISA for the estimation of various autoantibody levels (anti-endothelial cell antibodies, anti-cardiolipin, anti-beta 2GPI and anti-modified LDL antibodies) and correlated them with the occurrence of thromboembolic events in general, and VAT in particular. We have found that the levels of antibodies reactive with human umbilical vein endothelial cells (HUVEC) but not with other EC lines (microvascular or EaHy 929) were significantly higher in hemodialysed patients with VAT in comparison with patients with no VAT (p = 0.001). A weaker but yet positive correlation was observed between the levels of anti-HUVEC and anti-cardiolipin antibodies and the occurrence of thromboembolic events including deep vein thrombosis, pulmonary infarction, cerbrovascular events and VAT (both p-values equal 0.02). Anticardiolipin antibodies (aCL) were not cross reactive with beta 2GPI or with HUVEC. Antibodies to modified LDL, although higher in hemodialyzed patients, did not correlate with thromboembolic events. The results of this study suggest that antibodies to HUVEC may prove as a fairly good marker of VAT in hemodialysis. High levels of aCL are weakly associated with thromboembolic events and antibodies to modified LDL do not correlate with a prothrombotic state.

Adult↗
PubMed1998

Hantavirus seropositivity in Israeli patients with renal failure.

The hantavirus is known to cause hemorraghic fever with renal syndrome (HFRS), which is widely spread in Europe and Asia. Several reports have shown an association of hantavirus antibody titers and the occurrence of renal dysfunction. From these observations, it appears that the virus is widely distributed, and different strains prevail in various areas. In the present work we studied 81 patients with end-stage renal-failure under hemodialysis (HD) treatment, 55 with mild to moderate renal failure, and 50 healthy subjects for the presence of antibodies to Hantaan and Puumala viruses. We found that 12.3% of the hemodialysis patients and 9% of the mild to moderate renal failure patients had elevated IgG anti-body titers to Puumala virus compared with 2% of the controls. IgM antibodies to Puumala virus was principally elevated in patient with chronic renal failure (CRF) not on hemodialysis (14.5%) compared with the hemodialyzed (1.2%) and controls (0%) subjects. Hantaan virus IgG antibodies were detected in 3.7% of the HD patients, 5.5% of the CRF not on HD, and in none of the controls. IgM Hantaan antibodies were found only in the non-HD renal failure patients. None of the sera were found to contain antibodies to phospholipids or single-stranded DNA. These results emphasize the widespread nature of infection with hantaviruses and imply that elaborate testing for these serologies should be performed, especially in patients with unexplained renal failure.

Female↗
PubMed1997

Israeli and Palestinian families in the peace process: sources of stress and response patterns.

The Israeli-Palestinian peace process is characterized by its unknown outcomes and consequences for the families involved. The purpose of this study was to identify family processes under conditions of prolonged uncertainty. Data were collected from both Israeli and Palestinian families in the West Bank by means of semi-structured interviews. Qualitative and quantitative analyses showed cross-cultural differences in the perception of the situation; different kinds of concerns and sources of stress; different coping responses; and differences in dyadic interaction patterns and intrafamily processes. The findings are discussed in social-contextual terms, particularly the ways in which political and cultural contexts shape the perception of the situation and family processes under prolonged stressful conditions.

Adaptation, Psychological↗
PubMed1997

Family, migration, and psychosocial adjustment to illness.

The present study examines the coping style of new immigrants in Israel from the former Soviet Union who have been diagnosed with cancer. One hundred and six new immigrants, who were being treated at the Linn Clinical Oncological Institute in Haifa during the first six months of 1992, participated in the study. They were assessed regarding family functioning, the stresses of the migratory process, other life stresses, and psychosocial adjustment to the illness. Contrary to expectations about the influence of family adaptability and cohesion on coping with illness, immigrant participants reported that the combination of stressful events related both to the migratory process and to the illness itself is the best predictor of coping with illness.

Adaptation, Psychological↗
PubMed1996

Successful treatment of secondary hyperparathyroidism in hemodialysis patients with oral pulse 1-alpha-hydroxy-cholecalciferol therapy.

We have used high-dose oral pulse therapy with 1 alpha-hydroxycholecalciferol (1 alpha-OH-D3) to treat 40 hemodialysis patients suffering form secondary hyperparathyroidism. Forty patients with intact parathyroid hormone (PTH) levels of > 150 pg/ml were treated with 4 micrograms oral 1 alpha-OH-D3 twice weekly for 1 year. The mean PTH level was 515 +/- 50 pg/ml prior to treatment, which fell to 191 +/- 42 pg/ml after 6 months of treatment (p < 0.00001), and to 164 +/- 39 pg/ml after 12 months of treatment. Patients with very high PTH levels (> 800 pg/ml) suppressed less well than patients with lower levels (150-300 pg/ml). The therapeutic end point of PTH < 100 pg/ml was achieved in 23 patients (58%). The main side effect of the treatment was hypercalcemia, but this was symptomatic in only 3 patients, all above the age of 70 years. In summary, oral high-dose pulse therapy with 1 alpha-OH-D3 was highly effective in suppressing PTH levels in hyperparathyroid hemodialysis patients, and side effects were relatively few.

Administration, Oral↗
PubMed1996

Cross-cultural differences between Russian immigrants and Israeli college students: the effect of the family on the sense of coherence.

Differences between Israeli-born and Soviet-born college students were investigated in relation to their sense of coherence, family functioning and gender. 167 Soviet born and 127 Israeli born college students were compared on the Sense of Coherence scale, the General Functioning Scale of the McMaster FAD, and the scales of cohesiveness and adaptability of the FACES III, as well as on a variety of demographic variables. Results indicated that the stress of migration had a negative effect on the Sense of Coherence. Family functioning was the only variable that added significantly to the explanation of the variance of Sense of Coherence.

Acculturation↗
PubMed1992

Families in the sealed room: interaction patterns of Israeli families during SCUD missile attacks.

This study attempted to delineate styles of family interaction and behavior during war. Sixty-six families were randomly selected during the first week of the Gulf War and were telephone-interviewed using a semi-structured questionnaire. Qualitative methodology was used to analyze the interview transcripts. Three themes emerged: the emotional atmosphere (degree of expressed stress), mode of family organization, and extent and form of interpersonal relationship. When these categories were considered, four types of families were found: (1) the Anxious Family, characterized by high level of stress, low role distribution, negative interaction style; (2) the Cautious Family, with high stress, clear role allocation, positive interaction among members; (3) the Confident Family, typified by low stress level, clear role allocation, and positive non-interaction; and (4) the Indifferent family, characterized by low stress level, no role allocation, and negative non-interaction. These findings are discussed in terms of recent attempts to clarify the concept and describe the process of family coping, as well as in terms of understanding family behavior in other stressful situations.

Adaptation, Psychological↗
PubMed1991

Effect of intrahypothalamic injections of norepinephrine and serotonin on plasma arginine vasotocin and mesotocin in the White Leghorn cockerel.

1. Saline (10 microliters), norepinephrine (NE) and Serotonin (5-HT), 500 nmol each, were injected into the anterior third ventricle (A3V; n = 7) or the posterior third ventricle (P3V; n = 11) of ananesthetised, unrestrained White Leghorn cockerels. Plasma arginine vasotocin (AVT) and mesotocin (MT) were measured 20, 60 and 120 min after injection. 2. Injection of NE into both the A3V and P3V had no significant effect on either plasma AVT or plasma MT at any of the sampling times. 3. Administration of 5-HT into the A3V significantly increased plasma MT about two-fold 20 min following injection. At 120 min time, plasma MT returned to normal. 4. In P3V birds, 5-HT had no effect on plasma MT in the first 20 min, but a significant increase in plasma MT occurred 60 to 120 min after injection. The magnitude of the response was lower than in the A3V cockerels. 5. Plasma AVT was not affected by 5-HT administration into the A3V at any of the sampling times, but 5-HT administration into the P3V caused significant rises in plasma AVT at 120 min. 6. Serotonergic, but not noradrenergic, induction of neurohypophysial peptide secretion was demonstrated.

Animals↗
PubMed1989

Using hospital site visits for teaching occupational health.

In medical schools, the factory visit is an important ingredient of occupational health instruction at all levels. Usually the time allotted for teaching this subject in the undergraduate curriculum is limited; as a response to this constraint, the Tel Aviv University Sackler Faculty of Medicine has used its associated teaching hospitals as the "factory" since 1982. Following an introductory discussion, the students are divided into small groups and sent to various departments of the hospital--wards, kitchen, laundry, maintenance workshop, X-ray department, and surgery--to observe and evaluate the work environment. Following this activity, the students reconvene and discuss the health implications of what they have seen. This way of providing the factory visit is well accepted by the students, saves time, and contributes directly to the students' awareness of their own working environment.

Education, Medical, Undergraduate↗
PubMed1988

The calcium channel blocker nisoldipine delays progression of chronic renal failure in humans (preliminary communication).

Chronic renal failure (CRF) patients with a stable course were asked to participate in a follow-up program in which they were randomized into two groups: 1) the placebo group taking their standard antihypertensive therapy without any calcium ion blocker: and 2) the nisoldipine group, those patients taking the calcium channel blocker nisoldipine as the only antihypertensive drug. The two groups had similar blood pressures on entering the study (151 +/- 21.3/90.7 +/- 7.4 mmHg in the nisoldipine and 146.7 +/- 18/94 +/- 9.4 mmHg in the placebo group). Their protein intake was also similar (daily average throughout the follow-up period: 0.83 +/- 0.18 g protein per kg body weight in the nisoldipine and 0.9 +/- 0.12 g in the placebo group). The patients were checked monthly. The follow-up averaged 11.1 +/- 4.8 months in the nisoldipine group and 13.7 +/- 4.2 months in the placebo group. The rate of progression of CRF, as expressed by the slope of the regression line of 1/serum creatinine versus time, decreased in the nisoldipine group from the initial (-8.03 +/- 4.91) x 10(-3) to (-5.57 +/- 5) x 10(-3) (two-tailed P-test = 0.016) after intervention. The slopes tended to become steeper in the placebo group, with an initial slope of (-4.1 +/- 3.2) x 10(-3) changing to (-7.9 +/- 5) x 10(-3) after intervention. This difference did not reach statistical significance (two-tailed P = 0.072). The rate of progression of CRF decreased in 12 of 14 patients in the nisoldipine-treated group versus 3 of 11 patients in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗