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Biomedical subjects

A Levy

Publications and source records attributed to A Levy.

At least 109 records · Page 6Linked to original sources
PubMed1998

Diurnal changes in the expression of genes encoding for arginine vasotocin and pituitary pro-opiomelanocortin in the rainbow trout (Oncorhynchus mykiss): correlation with changes in plasma hormones.

Using quantitative in-situ hybridization, this study monitored diurnal changes in the abundance of the gene transcripts of two corticotropin-releasing peptides, arginine vasotocin (AVT) and isotocin in hypothalamic neurones, and of pro-opiomelanocortin (POMC) mRNA in the pituitary of the rainbow trout (Oncorhynchus mykiss). A significant diurnal pattern of gene expression was only displayed in the hypothalamus by the parvocellular AVT neurones of the preoptic nucleus. Abundance of AVT mRNA in these neurones was low at lights on (06.00 h), increased during the morning to reach a plateau of peak values between 14.00 h and 22.00 h, and then declined during the dark phase. This pattern was the inverse of that shown by plasma cortisol values. Changes in AVT transcript abundance are also considered in terms of the reported diurnal change in circulating AVT concentration. Pituitary and hypothalamic AVT peptide content did not change. Transcripts of both POMC genes (POMC-A and POMC-B) were monitored in pituitary corticotropes and melanotropes. Only POMC-A mRNA was detected in corticotropes where it showed no diurnal change in abundance. Transcripts of both POMC genes were found in the melanotropes, although, judging from autoradiographic intensity, POMC-A mRNA predominated. Both genes showed diurnal differences in their transcription with POMC-A mRNA showing peak values at 10.00 h and a nadir at 02.00 h, while POMC-B mRNA showed an inverse pattern. The results indicate that the two POMC genes can be independently regulated.

Animals↗
PubMed1998

Haemodynamic stability and ketamine-alfentanil anaesthetic induction.

We have determined if alfentanil could obtund the haemodynamic instability commonly seen at induction of anaesthesia with ketamine. Five groups of ASA I and II patients received ketamine 1 mg kg-1 i.v., preceded by saline (group 1) or alfentanil 10, 20, 30 or 40 micrograms kg-1 (groups 2-5, respectively). Heart rate (HR), mean arterial pressure (AP), postoperative patient complaints and dysphoria were noted. All groups showed increases (P < 0.05) in both HR and AP after administration of ketamine, which were progressively smaller as the dose of alfentanil increased. After tracheal intubation, all groups showed further increases in HR and AP, with groups 3-5 (alfentanil 20-40 micrograms kg-1) showing significant obtundation (P < 0.05) of these increases compared with group 1. No patient in any group reported postoperative dysphoria or dissatisfaction with their anaesthetic. Ketamine 1 mg kg-1 with alfentanil 20-40 micrograms kg-1 provided statistically significant obtundation of the haemodynamic instability that is common with ketamine alone.

Adolescent↗
PubMed1998

Prevalence of intestinal infections caused by diarrheagenic Escherichia coli in Bedouin infants and young children in Southern Israel.

OBJECTIVE: To evaluate the prevalence of different Escherichia coli categories in symptomatic and asymptomatic infants and children residing in a Bedouin township in Southern Israel. METHODS: A total of 1613 stool samples were collected from a cohort of 234 infants and young children followed from birth up to 2 years of age. E. coli colonies from stool cultures from children during a diarrhea episode and those from nondiarrhea stools were hybridized with DNA probes specific for enteropathogenic, enteroinvasive, enterotoxigenic (ETEC), enteroaggregative, diffuse adherent and enterohemorrhagic strains. RESULTS: There were 1469 of 1613 (91%) samples positive for E. coli. The prevalence of E. coli categories was: enteroaggregative (25.9%); diffuse adherent (21.8%), ETEC (12.9%); enteropathogenic (7.3%); enterohemorrhagic (0.5%); and enteroinvasive (0.2%). ETEC, expressing the heat-stable enterotoxin (ST), was the only category isolated significantly more often from cases than from controls (P = 0.005). Of the two heat-stable enterotoxins screened in this study, only ETEC-heat stable enterotoxin (STh), the form isolated from human pathogenic ETEC, could be associated with diarrhea, whereas ETEC-STp, produced by ETEC of porcine origin, was not related to diarrhea. ETEC infections peaked during the warm, dry season. Prolonged shedding of E. coli postdiarrhea was not found in this population. CONCLUSION: The present cohort study confirmed that in this semiurban area, highly endemic for diarrheal disease, ETEC is an important cause of diarrhea in children.

Arabs↗
PubMed1998

Limitations of radionuclide angiographic assessment of left ventricular systolic function before lung transplantation.

To evaluate the influence of increased right ventricular afterload on radionuclide assessment of the left ventricular ejection fraction (LVEF), we compared the preoperative and postoperative value of isotopic LVEF in 11 patients who underwent lung transplantation and had a preoperative LVEF value below 55% (normal value: 68 +/- 8%). The underlying disease conditions were obstructive lung disease (n = 7) and pulmonary fibrosis (n = 4). The transplantation procedure was unilateral in 10 patients and bilateral in one. The mean value of isotopic LVEF prior to transplantation was 51 +/- 3% (range: 49% to 55%). At 42 +/- 13 mo postoperatively, isotopic LVEF increased significantly, to 65 +/- 10% (p = 0.001), suggesting that intrinsic left ventricular systolic function was in fact normal in these patients. We hypothesize that the low preoperative isotopic LEVF was not related to intrinsic dysfunction of the left ventricle, but rather to right ventricular pressure overload, leading to bulging of the interventricular septum into the left ventricle and to subsequent geometric distortion of the left ventricle. We conclude that isotopic LVEF may underestimate intrinsic left-ventricular systolic function in patients with severe chronic lung disease. Candidates for lung transplantation should not be rejected on the basis of a low isotopic LVEF, provided echocardiographic examination does show apparently normal left ventricular contraction.

Adult↗
PubMed1997

Effects of metrifonate on radial arm maze acquisition in middle-aged rats.

The efficacy of metrifonate, a well-tolerated cholinesterase (ChE) inhibitor, in attenuating the normal aging- and corticosterone-induced impairments of radial maze performance of rats was compared. Middle-aged Fischer 344 rats were screened for their spatial orientation performance in the Morris water escape task. Good and bad performers were selected: good performers (N= 22) were treated with subcutaneous sustained-release corticosterone pellets, resulting in hippocampal cell damage and impaired spatial orientation in the radial maze; age-induced bad performers (N = 20) were tested without additional pharmacological intervention. Metrifonate (MFT), administered daily during radial maze testing, 30 min before training, at a dose of 15 mg/kg p.o., facilitated the acquisition of the task in age-impaired rats, but not in corticosterone-impaired rats.

Age Factors↗
PubMed1997

[Pneumopathy caused by minocycline].

BACKGROUND: Minocycline has been identified as a pathogenic agent in drug-induced pneumonia. We report a new case. CASE REPORT: A 38-year-old female asthmatic patient was given minocycline (100 mg/j) for facial acne. She was allergic to penicillin. Other treatments were theophylline, salbutamol and inhaled budesonide. Severe bilateral hypoxemia pneumonia developed with high eosinophil blood counts within a few days of treatment onset. The lung disease regressed with minocycline withdrawal. DISCUSSION: This case is exceptional because the minocycline-induced lung disease continued to progress despite high-dose corticosteroids in this asthmatic patient.

Adult↗
PubMed1997

[Reporting maternal behavior during diarrhea in Bedouin children].

Diarrhea is still a major cause of morbidity and mortality among children in developing countries. The Bedouin population of southern Israel is in transition from a nomadic to a settled life-style. We examined maternal knowledge and reported behavior when their children had diarrhea. Mothers defined diarrhea as the passing of 4-5 stools per day. The most frequent signs of the illness were an increased number of watery stools with changes in either color or form. The most frequent symptom that prompted mothers to seek medical aid was blood in the stool. All mothers reported increasing fluid intake in their children during diarrhea, and most reported giving herbal tea. About half of the women avoided milk products and used special foods for the treatment of diarrhea. A quarter of the women reported stopping or decreasing the frequency of breast feeding during diarrhea. Reported cessation of breast feeding during diarrhea was associated with changing to special foods, and failure to note the onset of diarrhea or to recognize signs of dehydration. The withdrawal of breast feeding during episodes of illness and diarrhea is related to lack of knowledge regarding diarrhea. These data indicate that even in this population, with free access to preventive and curative medical care, there should be greater efforts to educate mothers to detect diarrheal disease and to maintain breast feeding during the diarrhea.

Arabs↗
PubMed1997

[Epidemiologic characteristics of pediatric emergency room referral and hospitalization for diarrhea in the Negev].

Diarrheal diseases weigh heavily on the health of children, especially in developing countries, but also impose burdens on health care services worldwide. This study was performed to determine whether patterns of referrals in the Negev to the pediatric emergency room (PER) for diarrhea differ between the Jewish and Bedouin populations of the Negev, and the extent of the burden imposed on the PER and in-hospital services in the Negev. Characteristics of referrals and hospitalizations were examined from March 1994 to February 1995. Of the 27,834 referrals to the PER for children under 16, 2518 (9%) had diarrhea and there were 5,169 hospital admissions, 701 (13.6%). The annual rates of referral were 146 per 10,000 in Jews and 225 in Bedouin, giving an odds ratio (OR) of 1.5 (p < 0.001). for Bedouin. The rates of hospitalization were 23 per 10,000 in Jews and 99 in Bedouin (OR 4.4, p < 0.001). 1380 (54.8%) of the PER referrals were of infants under a year of age. For hospitalization, the annual rates were 164 per 10,000 in Jews and 756 in Bedouin (OR 4.9, p < 0.001). During June to August referrals and hospitalizations for diarrhea were significantly higher, and from December to February significantly lower than during the remaining months. These differences arise from the marked seasonal pattern in the Bedouin population, whereas in the Jewish population there was no seasonal variation. Even in the 90's the burden on health services in the Negev as a result of diarrheal illness is considerable and the Bedouin population still contributes to that burden disproportionately. There is need both to reduce the gap in referrals and hospitalization between the populations, as well as to reduce the rates, using currently available means such as education, while developing new technologies, such as vaccines.

Adolescent↗
PubMed1997

Association of the Epstein-Barr virus with Hodgkin's disease in Southern Israel.

Epstein-Barr virus (EBV) has been frequently documented in the putative neoplastic Hodgkin-Reed-Sternberg (HRS) cells, in lymph nodes from patients with Hodgkin's disease (HD). This association varies in different geographic areas and between industrialized and developing countries, as does the epidemiological pattern of the disease. In the present study of 106 cases of HD from the Soroka Medical Center in Beer-Sheva, which serves as the only hospital for most of the southern part of Israel, we found an association with EBV expression in only 30% of the patients; 45% of mixed cellularity (MC) cases compared with 21% of nodular sclerosis (NS) cases were positive for EBV. The number of patients in the 0-14-year-old age group was limited; however, 8 of these II children were EBV positive. This low association rate of HD with the presence of EBV sequences is probably related to the small number of children in our series. A low proportion of EBV-associated disease in older adults may be contributory. Other factors may be involved.

Adolescent↗
PubMed1997

[Between "transparent room" and "sealed room:" professional confidentiality and therapeutic judgement].

Patients and therapists are concerned with the complexities of protecting medical confidentiality. The traditional perception of protection of patient confidentiality is that the individual's interest in protecting his confidentiality may conflict with the public's need for information, especially in cases involving possible danger. In fulfilling his dual role of representing both the patient and the public, the therapist acts according to existing laws and regulations. We describe 3 cases in which refraining from providing the Army with information in accordance with the law was recognized in retrospect as having caused the patient suffering, and even danger. It is recommended that the therapist's judgement be considered in addition to other legal criteria for determining whether or not to protect patient confidentiality.

Adult↗
PubMed1997

Nimodipine's protection against corticosterone-induced morphological changes in the hippocampus of young rats.

Sustained high levels of corticosterone (CORT), one of the major stress-induced hormones in the rat, were suggested as generating 'accelerated brain aging' and were shown to induce both specific brain changes in the hippocampus and learning impairments in young and middle-aged Fischer-344 rats. Evidence that altered calcium (Ca) homeostasis may play a major role in brain aging has accumulated over the last decade. Recently, new data established a connection between glucocorticoids and voltage-activated Ca influx in aged hippocampal neurons. In the present study, an attempt was made to block the CORT-induced 'accelerated aging' by the simultaneous administration of the L-type Ca channel blocker nimodipine. CORT or placebo sustained-release (SR) pellets were implanted subcutaneously in 3 months old Fischer male rats. Each group was further sub-divided between nimodipine and placebo SR treatments. Characteristic CORT-induced morphological changes were observed in pyramidal hippocampal cells, such as at the CA1 and CA4 sub-regions (22.2% +/- 7.7 and 28.6% +/- 8.4 of pyknotic cells without clear nuclei, respectively). Concomitant treatment with nimodipine conferred full protection against CORT-induced morphological changes (e.g. 3.2% +/- 0.8 and 2.1% +/- 1.9 of pyknotic cells in CA1 and CA4, n = 7 rats in each group; P < 0.04). The neuroprotective efficacy of nimodipine supports the theory of Ca involvement in CORT related 'accelerated brain aging'.

Aging↗
PubMed1997

Isocratic non-aqueous reversed-phase high-performance liquid chromatographic separation of capsanthin and capsorubin in red peppers (Capsicum annuum L.), paprika and oleoresin.

A simple, rapid high-performance liquid chromatography method has been devised in order to separate and quantify the xanthophylls capsorubin and capasanthin present in red pepper (Capsicum annuum L.) fruits and preparations made from them (paprika and oleoresin). A reversed-phase isocratic non-aqueous system allows the separation of xanthophylls within a few minutes, with detection at 450 nm, using methyl red as internal standard to locate the various carotenoids and xanthophylls found in plant extracts. The selection of extraction solvents, mild saponification conditions, and chromatographic features is evaluated and discussed. The method is proposed for rapid screening of large plant populations, plant selection, as well as for paprika products and oleoresin, and also for nutrition and quality control studies.

Azo Compounds↗
PubMed1997

Clastogenic factors in the plasma of children exposed at Chernobyl.

Clastogenic factors (CFs), as they were described previously in accidentally or therapeutically irradiated persons, in A-bomb survivors and in liquidators of the Chernobyl nuclear power plant, were also detected in the plasma of Chernobyl-exposed children. A high percentage of plasma ultrafiltrates from 170 children, immigrated to Israel in 1990, exerted clastogenic effects in test cultures set up with blood from healthy donors. The differences were highly significant in comparison to children immigrated from 'clean' cities of the former Soviet Union or children born in Israel. The percentage of CF-positive children and the mean values of the adjusted clastogenic scores (ACS) were higher for those coming from Gomel and Mozyr, which are high exposure sites (IAEA measurements), compared to those coming from Kiev. There was no correlation between residual 137-Caesium body burden and presence of CFs. However, both measurements were not done at the same time (in 1990 and 1992-1994, respectively). Also no relationship could be revealed between enlargement of the thyroid gland and CF-positivity. CFs are not only observed after irradiation, but in a variety of chronic inflammatory diseases with autoimmune reactions. They were also described in the congenital breakage syndromes, which are hereditary diseases with the highest cancer incidence in humans. Whether the clastogenic effects continuously produced by circulating CFs represent a risk factor for malignant late effects deserves further study and follow-up. Since CF formation and CF action are mediated by superoxide radicals, prophylactic treatment with antioxidants may be suggested for Chernobyl-exposed children, whose plasma induces a strongly positive CF-test.

Autoimmune Diseases↗
PubMed1997

Expression of MCH and POMC genes in rainbow trout (Oncorhynchus mykiss) during ontogeny and in response to early physiological challenges.

The expression of the neuropeptide melanin-concentrating hormone (MCH) in two groups of hypothalamic neurones (NLT- and LVR-MCH neurones), and POMC in the pituitary corticotropes and melanotropes, has been examined in rainbow trout larvae using immunocytochemistry and quantitative in situ hybridization. The aim was to establish at what stage in ontogeny these cells first respond to two physiological challenges-background color and stress. Trout reared in black or white trays showed adaptive skin pigmentary changes at 10 days posthatching, when fish in a pale environment abruptly exhibited melanin aggregation from a prior dispersed state, although the pigment cells were already competent to respond to adrenalin and MCH in vitro at 3 days. Immunoreactive MCH was detectable in the neurohypophysis at hatching and MCH mRNA in the NLT-MCH neurones (which project to the pituitary) was enhanced at 7 days in the white-reared trout. Immunostainable POMC was also present in the pars intermedia at hatching but their POMC mRNA was unaffected by tank color until 28 days, when it was enhanced in the black-reared trout. It is suggested that early pigment concentration depends on neural signals from the sympathetic nervous system in conjunction with MCH from the NLT rather than on a reduction in alphaMSH secretion from the pars intermedia. MCH mRNA in the LVR-MCH neurones was increased on a pale environment only 28 days after hatching, suggesting that these cells play little role in the early adaptive pigment response. Previous studies on the ontogeny of cortisol secretion indicate the hypothalamopituitary-interrenal axis can respond to stress by about 14 days. However, the pituitary ACTH cells showed no stress-induced changes in POMC mRNA until 28 days. ACTH release may therefore be dissociated from POMC transcription in the early stages of development. The LVR- and NLT-MCH neurones were both stimulated by stress, LVR-MCH mRNA responding by 14 days and NLT-MCH mRNA by 21 days. Melanotrope POMC mRNA was reduced by stress but the physiological significance of this is not known.

Aging↗