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Biomedical subjects

Y Weisman

Publications and source records attributed to Y Weisman.

At least 19 recordsLinked to original sources
PubMed2005

S1 gene characteristics and efficacy of vaccination against infectious bronchitis virus field isolates from the United States and Israel (1996 to 2000).

The S1 genes of isolates of avian coronavirus infectious bronchitis virus (IBV) from commercial chickens in the US and Israel (20 isolates from each country) were studied using reverse transcription-polymerase chain reaction restriction fragment length polymorphism and sequencing. Partial sequences spanning the amino terminus region of S1 from amino acid residues 48 to 219, based on the Beaudette strain, were used for analysis. Phylogenetic clustering and high-sequence identity values were used to identify isolates that appeared to be derived from live IBV vaccines used in the two countries. Novel variant strains, unrelated by S1 sequencing and restriction fragment length polymorphism analyses to reference and vaccine strains, were also identified. Based on S1 sequence identity to available vaccines, the potential to use vaccination to control IBV infections was evaluated. Vaccination with commercial live strains Massachusetts (Mass), Arkansas (Ark) or DE/072/92, generally produced immunity against vaccine-related field isolates displaying high S1 sequence similarities (> or = 90%) to the respective vaccine strains. Immunization with a bivalent vaccine containing the Mass and Ark strains provided good cross-protection, averaging 81% against challenge with five variant isolates from the US having amino acid identity values ranging from 62 to 69% to Mass and from 68 to 83% to Ark, respectively. In contrast, the H120 vaccine strain induced low levels of protection, ranging from 25 to 58% against variant field isolates from Israel with amino acid identity values from 65 to 67%.

Animals↗
PubMed2002

Antigenic heterogeneity among the field isolates of Newcastle disease virus (NDV) in relation to the vaccine strain: 1. Studies on viruses isolated from wild birds in Israel.

In order to reveal the viruses strongly differing from the VH NDV strain used in Israel for poultry vaccination, 54 NDV strains isolated during the last 15 years in Israel from feral birds were studied by means of the panels of 39 monoclonal antibodies. Six isolates were found to have considerable antigenic differences in envelope proteins as compared to the vaccine strain. In four cases, the differences were related mostly to the hemagglutinin-neuraminidase glycoprotein, in one case to the fusion glycoprotein, and in one case to the matrix protein.

Animals↗
PubMed2002

Antigenic heterogeneity amongst the field isolates of Newcastle Disease Virus (NDV) in relation to the vaccine strain. Part II: studies on viruses isolated from domestic birds in Israel.

Forty three Newcastle disease virus (NDV) strains isolated before and during 1997 in Israel from domestic birds were studied by means of the three panels of monoclonal antibodies prepared against all the viral envelope proteins in order to reveal the possible antigenic differences between them and the VH strain used in Israel for poultry vaccination. Three isolates were found to have significant antigenic differences in the hemagglutinin-neuraminidase (HN) and fusion (F) glycoproteins as compared to the vaccine strain. As to the matrix protein, almost all the viruses isolated during the year 1997 were found to have considerable differences from the vaccine strain in two of four antigenic sites.

Animals↗
PubMed2002

A low-dose adrenocorticotropin test reveals impaired adrenal function in cancer patients receiving megestrol acetate therapy.

Megestrol acetate (MA) has glucocorticoid activity and can induce significant secondary adrenal suppression. We designed this study to determine the extent of adrenal insufficiency in cancer patients receiving MA by utilising a sensitive low-dose adrenocorticotropin (ACTH) stimulation test. Adrenal function was assessed by a low-dose (0.625 microg) ACTH (1-24) stimulation test in 30 patients receiving MA for metastatic cancer. 10 of the patients who failed this test underwent a standard (250 microg) test on another day. Adrenal function was also evaluated in 15 of the patients by measuring the excretion of free cortisol in 24-h urine samples. Peak serum cortisol levels following stimulation with low-dose (0.625 microg) ACTH (1-24) were <18 microg/dl in 16 of 30 (53%) patients, of whom 9 had a basal serum cortisol level of <5 microg/dl. Five of 16 poor responders to the low-dose test showed normal stimulation with the standard (250 microg) ACTH (1-24) test. Thus, adrenal insufficiency would fail to be detected by the standard high dose test in these patients. Patients who failed the low-dose ACTH (1-24) test had lower 24-h urinary free cortisol excretion (8.7+/-10.3 microg/24 h) than normal responders (35+/-12.7 microg/24 h). Impaired adrenal function is common in cancer patients receiving MA. The low-dose ACTH (1-24) test is apparently capable of revealing adrenal insufficiency undetected by the standard high-dose ACTH test. Patients receiving MA might have inadequate adrenal function during episodes of infection or after withdrawal of MA therapy and this may require prompt corticosteroid treatment.

Adrenal Insufficiency↗
PubMed2002

Molecular identification of the Marek's disease virus vaccine strain CVI988 in vaccinated chickens.

The study describes three polymerase chain reaction (PCR) systems for the CVI988 vaccine virus: the meq gene, the MDV BamHI-D/H 132 bp tandem repeat fragment and the MDV-gB gene. Whereas the PCR product of virulent MDV strains and of the CVI988 virus strain with the meq and the 132 bp primer sets differed for the two templates, the MDV-gB PCR products were similar. The sensitivity of the three PCRs was determined for the two templates: the CVI988 DNA was detected up to 2.48 plaque forming units, and a MDV-1 DNA, was amplified with the 132 bp primers up to the 10(-3) DNA dilution, and up to the 10(-2) with the MDV-gB and meq gene primers. As conventional detection for the CVI988 vaccine virus is by tissue culture, the aim was to analyse the feasibility of the molecular detection of the vaccine virus in the vaccinated chick. In two experimental trials employing specific pathogen free and commercial Lohmann chicks, respectively, the vaccine virus replicated to a limited extent; it was detected only in the spleen of up to 60% chicks at 2-4 weeks and in one chick at 3 weeks, respectively. The survey of three commercial Lohmann flocks, kept in biosecurity conditions, revealed the vaccine virus only in the spleen of 40% of 30-day-old chicks. The present study shows that CV1988 DNA is present in vaccinated chicks in a low quantity and it is difficult to detect directly from the chick, probably because vaccine viruses are latent in vivo. For an efficient detection it is pertinent to cultivate the vaccine virus on chicken embryo fibroblasts (CEF), as then the virus escapes the latent state, enters into the productive mode of replication, and a high viral copy number is produced.

Animals↗
PubMed2001

The comparative antigenic characterization of Newcastle disease virus strains isolated in Kenya and Kazakhstan.

Twenty six Newcastle disease viruses--12 reference strains and 14 strains isolated in Kenya and Kazakhstan--were characterized by means of a large panel of 38 monoclonal antibodies (MAB) directed against all the three envelope proteins: matrix, hemagglutinin-neuraminidase and fusion. The essential distinctions were revealed between the viruses isolated in Kenya and Kazakhstan while the differences amongst the viruses belonging to the same local group were much smaller. The heterogeneity amongst the viruses isolated in Kenya was more expressed as compared to the Kazakhstanian strains.

Animals↗
PubMed2001

Benign occipital epilepsy mimicking a catastrophic intracranial event.

OBJECTIVE: To describe the rare, dramatic, presentation of benign occipital epilepsy. METHODS: We describe three children who presented to the pediatric emergency department from 1992 to 1996 with a clinical picture of catastrophic intracranial event. RESULTS: The main signs and symptoms were loss of consciousness in all patients, apnea in two, hemiclonus in two, general hypertonicity in two, eye deviation in two, fixed dilated pupils in one, and decorticate rigidity in two. All underwent emergency intubation, brain scan, and lumbar puncture, and all were treated with antibiotics, in addition to antiviral drugs in two. Two patients were also treated for suspected increased intracranial pressure. Two patients recovered within a few hours and one within 24 hours of admission without any residual neurologic deficit. Electroencephalograms, done within 48 hours after the event, revealed the classic pattern of occipital epilepsy in two patients and bilateral occipital slow wave in one. A 3- to 5-year clinical and electroencephalographic follow-up supported the diagnosis. CONCLUSION: Benign occipital epilepsy in children can mimic a catastrophic intracranial event. Electroencephalography, performed early in the Pediatric Intensive Care Unit, may avoid or shorten unnecessary and aggressive treatments such as hyperventilation, diuretic agents, and prolonged antiviral therapy.

Apnea↗
PubMed2001

West Nile fever in Israel 1999-2000: from geese to humans.

West Nile virus (WNV) caused disease outbreaks in Israel in the 1950s and the late 1970s. In 1998 an outbreak of WNV in goose farms and evidence of infection in dead migratory birds were reported. Consequently, human diagnostic services for WNV were resumed, including virus isolation, serology, and RT-PCR. Risk factors for infection were assessed by a serological survey in 1999, which revealed a seroprevalence of (a) 86% in people who had close contact with sick geese, (b) 28% in people in areas along bird migration routes, and (c) 27% in the general population. Following two fatal cases in Tel Aviv in September 1999 and one encephalitis case in the southern Eilot region, a regional serological survey was initiated there. The survey revealed two more WNV-associated acute encephalitis cases, an IgG seroprevalence of 51%, and an IgM seroprevalence of 22%. In the summer of 2000, acute cases of WN disease were identified in the central and northern parts of Israel, involving 439 people. The outbreak started in mid-August, peaked in September, and declined in October, with 29 fatal cases, primarily in the elderly. During the outbreak, diagnosis was based on IgM detection. Four virus isolates were subsequently obtained from preseroconverted frozen sera. Sequence and phylogenetic analysis of 1662 bases covering the PreM, M, and part of the E genes revealed two lineages. One lineage was closely related to a 1999 Israeli bird (gull) isolate and to a 1999 New York bird (flamingo) isolate, and the other lineage was closely related to a 1997 Romanian mosquito isolate and to a 1999 Russian human brain isolate.

Adult↗
PubMed2001

Use of live and inactivated vaccines in the control of West Nile fever in domestic geese.

The recent epizootic of West Nile fever in Israel affected predominantly young domestic geese between three and eight weeks old. Clinically, the birds presented paralytic signs while morbidity and mortality were severe in affected flocks. The condition was encountered from early September through late November on goose farms located throughout the country. Losses incurred by goose flocks were sufficiently great as to warrant investigation of ways to protect young geese against the neurological form of the disease. We have conducted a series of vaccination trials in which three-week old geese were immunized with an attenuated, commercial flavivirus vaccine derived from Israel turkey meningoencephalitis virus (TME). Birds were challenged two weeks later with a low Vero cell passage of West Nile virus by the intracerebral route. In a second group of experiments, inactivated and live TME vaccines were given in tandem at an interval of two weeks and challenged two weeks later. The third vaccination trial was based on West Nile virus (WNV) harvested from infant mouse brain, inactivated with formalin and oil adjuvanted. A single injection given either subcutaneously or intramuscularly resulted in 75% protection of the vaccinated groups, while two injections spaced two weeks apart resulted in 94% protection. Groups of geese, vaccinated at the farms and challenged under controlled conditions in the laboratory, showed levels of protection ranging from 39% to 72% for TME vaccine and 52% and 80% for WNV vaccine. The lower levels of protection are attributable to flocks being affected with intercurrent infections at the time of vaccination.

Animals↗
PubMed2001

The role of the vitamin D receptor in regulating vitamin D metabolism: a study of vitamin D-dependent rickets, type II.

In vitro studies and animal experiments suggest that the production of 1,25-dihydroxyvitamin D [1,25-(OH)(2)D] and 24,25-(OH)(2)D is reciprocally controlled by 1,25-(OH)(2)D. To investigate the role of the vitamin D receptor (VDR) in controlling vitamin D metabolism in humans, we studied 10 patients with vitamin D-dependent rickets type II due to a defective VDR. After a period of high dose calcium therapy, 7 of the patients had normal serum calcium, phosphorus, alkaline phosphatase, and plasma PTH levels (PTH-N), and 3 showed increased serum alkaline phosphatase and plasma PTH (PTH-H). Serum calcium, phosphorus, alkaline phosphatase, PTH, vitamin D metabolites, urinary calcium/creatinine, and renal phosphate threshold concentration were compared with unaffected family members that comprised the control group. Vitamin D metabolites were measured before and after an oral load of 50,000 U/m(2) cholecalciferol. Compared with the control group, 1,25-(OH)(2)D levels were significantly higher and 24,25-(OH)(2)D levels were lower in the PTH-N group and even more so in the PTH-H group. 1alpha-Hydroxylase (1-OHase) and 24-OHase activities were estimated by the product/substrate ratio. In the PTH-N group, 1-OHase activity was higher and 24-OHase activity was lower than in controls. In the PTH-H group, 1-OHase activity was even higher, probably due to an additive effect of PTH. Thus, 1,25-(OH)(2)D-liganded VDR is a major control mechanism for vitamin D metabolism, and PTH exerts an additive effect. Assessment of the influence of 1,25-(OH)(2)D shows reciprocal control of enzyme activity in man, suppressing 1-OHase and stimulating 24-OHase activity.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed2001

The hormonal milieu in early stages of bone cell differentiation modifies the subsequent sex-specific responsiveness of the developing bone to gonadal steroids.

We have established previously that rat bone tissue, as well as rat and human-derived bone cells in culture, show a sex-specific response to gonadal steroids in stimulation of the specific activity of the BB isozyme of creatine kinase (CK) and DNA synthesis. This response could be modified by manipulation of the endocrine environment during early stages in rat development. To further examine the influence of changing hormonal steroid milieu and vitamin D status on the action of gonadal steroids in developing bone tissue, we used two models of ectopic bone formation: demineralized tooth matrix (DTM) implanted under the skin, and femoral bone marrow (BM) transplanted under the kidney capsule of a syngeneic recipient mouse. The response to gonadal steroids in ossicles developed from implanted DTM depended on the recipient's gender; injection of estradiol 17beta (E2; 5 microg) into young female mice 21 days after DTM implantation increased, 24 h later, CK activity in the newly formed ossicles by approximately 60%, whereas injection of dihydrotestosterone (DHT; 50 microg) had no effect on CK activity. In contrast, in male mice, DHT but not E2 increased CK activity in the ossicles by approximately 50%. This sex-specific response was abolished in gonadectomized mice resulting in a similar response of the ossicles to both E2 and DHT. When DTM was implanted into vitamin D- deficient female mice, there was a lower basal CK activity and a significantly diminished response to E2 in the newly formed bone tissues. When BM, which contains mesenchymal and stromal cells and committed osteoprogenitor cells, was transplanted into 6-week-old intact or gonadectomized female or male mice, the response of the newly formed bone ossicles, 21 days after transplantation, to E2 or to DHT was according to the gender of the donor. Bone formed from BM obtained from female mice responded to E2 only and those formed from male BM responded to DHT only. Ossicles developed from BM obtained from gonadectomized mice showed lack of response to either gonadal steroid. Furthermore, only approximately 25% of the BM transplants obtained from castrated (CAST) male donors developed into ossicles. Ossicles formed from BM obtained from vitamin D-deficient female donors showed lack of response to gonadal steroids. These findings suggest that the manipulation of the hormonal milieu in early stages of the differentiation sequence of bone cells modifies the subsequent selective responsiveness of the developing bone tissue to gonadal steroids.

24,25-Dihydroxyvitamin D 3↗
PubMed2001

Physicians' attitudes towards patients' rights legislation.

Patients' rights laws, bills and charters aim at delineating the patient-physician relationship in regard to consent to medical treatment, confidentiality and related issues. The need to shape such an intimate relationship by way of legislation seems anomalous to some, but imperative to others. We present for the first time an insight into Israeli physicians' attitudes towards Israel's patients' rights laws, in a changing medical and socio-legal environment. The research results suggest that physicians are reluctant to participate in the implementation of such laws, demonstrated by the level of their misunderstanding of the law's norms and regulations, and subjective attitudes and perceptions. In order to ensure the medical community's participation in augmenting patients' rights, efforts should focus on improved legal and ethical education, enhanced cooperation of professional associations and joint action with legislators to assure a productive composition of these important acts.

Attitude of Health Personnel↗
PubMed2001

Vitamin D deficiency and insufficiency in Orthodox and non-Orthodox Jewish mothers in Israel.

BACKGROUND: The modest clothing that Orthodox Jewish women wear exposes very little of their skin to sunlight. Under these conditions they may develop vitamin D deficiency, even in sunny Israel. OBJECTIVES: To determine and compare the vitamin D nutritional status in Jewish orthodox mothers to that of non-orthodox mothers who live in the same metropolitan area in Israel. METHODS: 25-Hydroxyvitamin D was measured by competitive protein-binding radioassay in the sera of 341 Jewish Israeli mothers (156 orthodox and 185 non-orthodox). The sera were obtained 48-72 hours after childbirth during the late summer of 1998 and the spring of 1999. RESULTS: The mean (SD) serum concentration of 25-OHD was significantly (P < 0.002) lower (13.5 +/- 7.5 ng/ml) in the orthodox than in the non-orthodox mothers (18.6 +/- 9.6 ng/ml). Vitamin D deficiency (< 5 ng/ml) and insufficiency (< 10 ng/ml) were more common in the orthodox mothers (5.1% and 32.7% respectively) than in the non-orthodox mothers (2.7% and 13%, respectively). In subgroups of mothers supplemented with 400 units of vitamin D daily during pregnancy, vitamin D deficiency and insufficiency were less common (2.2% and 13%, respectively) in orthodox and non-orthodox mothers (0% and 8.1%, respectively). Vitamin D insufficiency was more common in the winter than in the summer only among non-orthodox mothers. CONCLUSIONS: The high prevalence of vitamin D deficiency and insufficiency in Israeli mothers raises the question whether vitamin D supplements should be given to pregnant women in Israel, at least to orthodox mothers.

Adult↗
PubMed2000

Antigenic characterization of the nucleocapsid protein of Newcastle disease virus by means of a new panel of monoclonal antibodies.

Nine monoclonal antibodies (MAB) against nucleocapsid protein (NP) of Newcastle disease virus (NDV) have been prepared and characterized. All the MABs were classified into three groups by means of the competitive binding assay. At least three antigenic sites were delineated on the NP. The 1st site includes two closely located epitopes; the 2nd site includes two related and two distinct epitopes; the 3rd site includes two closely related and one distinct epitopes.

Antibodies, Monoclonal↗
PubMed2000

Interaction of monensin and sulfadimethoxine in broilers, as mediated by hepatic microsomal cytochrome P-450 monooxygenases.

The influence of monensin + sulfadimethoxine on cytochrome P-450 monooxygenase activity in broilers, and the possible consequences of modification of this system, including changes in blood levels of sulfadimethoxine, influence on the duration of xylazine-ketamine anesthesia, total antioxidant status and superoxide dismutase activity were studied. The results indicate that the combination of monensin + sulfadimethoxine gave a short-term inhibition of microsomal cytochrome P-450 monooxygenase activity but apparently did not influence the metabolism of other (exogenic) substances (ketamine, xylazine), and did not change the state of antioxidant systems or the relative liver weight. There was a rise in blood sulfadimethoxine levels.

Animals↗