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Biomedical subjects

Y Weiss

Publications and source records attributed to Y Weiss.

At least 19 recordsLinked to original sources
PubMed1996

[Epidural analgesia for postoperative pain in infants and children].

Until recently it was thought that children do not suffer as much from postoperative pain as adults. Coupled with the fear of administering systemic opiates to young children, this meant that babies were often left "to cry it out." Lately it has been acknowledged that children and even babies not only feel pain, but similar to adults, suffer from the physiologic consequences of the untreated stress response. It has also been shown that preventing this response improves the postoperative period in babies after undergoing cardiac surgery. Regional analgesia is commonly used to provide postoperative pain control in adults and children. Following minor lower abdominal surgery, pain relief is often provided by caudal analgesia or specific nerve blocks. Epidural and spinal anesthesia are also gaining popularity for young children and even babies. We describe 3 cases of continuous epidural analgesia in babies, and review other methods for postoperative pain relief. These cases are representative of the many which we have treated over the past 2 years. We use epidural analgesia in children who undergo major thoracic, abdominal, pelvic and major lower limb surgery, and are expected to suffer significant postoperative pain for more than 24 hours. We have not encountered any major complications or inadvertent dural punctures. We judiciously monitor these children, especially their respiratory function, as long as they receive epidural narcotics.

Adult↗
PubMed1996

Positive end-expiratory pressure-induced hemodynamic changes are reflected in the arterial pressure waveform.

OBJECTIVE: To examine whether the hemodynamic changes due to mechanical ventilation with positive end-expiratory pressure (PEEP) can be assessed by the respiratory-induced variations in the arterial pressure waveform during normovolemia and experimental acute ventricular failure. DESIGN: Prospective, controlled experimental study. SETTING: Institutional experimental laboratory. SUBJECTS: Adult mongrel dogs. INTERVENTIONS: Experimental acute ventricular failure was induced by the infusion of pentobarbital (a cardiodepressant) and methoxamine (a vasoconstrictor), combined with volume loading. Both the control and acute ventricular failure groups were subjected to ventilation with incremental levels of PEEP up to 20 cm H2O. MEASUREMENTS AND MAIN RESULTS: Cardiac function was evaluated by cardiac output and left and right ventricular change in pressure over time (dP/dt) measurements. Arterial pressure waveform analysis was performed by measuring the systolic pressure variation, which is the difference between the maximal and minimal systolic blood pressure values during one mechanical breath. The components of the systolic pressure variation, namely, dUp and dDown, which are the increase and decrease in the systolic pressure during the mechanical breath relative to the systolic pressure during apnea, were also measured at each PEEP level. PEEP caused significant reduction of cardiac output in normovolemic dogs, and was associated with significant increases in systolic pressure variation and dDown. Acute ventricular failure decreased the variations in the systolic pressure and caused the dDown component to disappear. The application of PEEP did not affect cardiac output in dogs with acute ventricular failure, nor did it change systolic pressure variation and the dDown. CONCLUSIONS: Analysis of arterial pressure waveforms during mechanical ventilation reflected the decrease in cardiac output in dogs with normal cardiac function subjected to incremental PEEP. In dogs with acute ventricular failure in which PEEP did not affect cardiac output, the systolic pressure variation was similarly unaffected by PEEP. In the absence of cardiac output measurement during mechanical ventilation with PEEP, the analysis of the respiratory variations in the arterial pressure waveform may be useful in assessing changes in cardiac output.

Animals↗
PubMed1995

Prevention of diabetes-associated embryopathy by overexpression of the free radical scavenger copper zinc superoxide dismutase in transgenic mouse embryos.

OBJECTIVES: It has recently been suggested that oxygen free radicals are involved in the high incidence of fetal dysmorphogenesis that is associated with diabetic pregnancies. The purpose of the current investigation was to study the effect of copper zinc superoxide dismutase, a free radical scavenging enzyme, on the prevention of diabetes-associated embryopathy in mice. STUDY DESIGN: Mice used in this study were either transgenic, bearing the human copper zinc superoxide dismutase gene, or nontransgenic controls. Diabetes was generated by streptozotocin administration on days 6 and 7 of gestation. Hyperglycemia developed on day 8 and was maintained through day 10 (critical period of organogenesis). On day 10 fetuses were examined for external anomalies, and their crown-rump lengths and deoxyribonucleic acid content were determined. RESULTS: Induction of maternal diabetes produced a significant reduction in mean crown-rump length of control embryos (4.48 +/- 0.7 mm vs 3.65 +/- 0.6 mm, p = 0.0001), whereas transgenic embryos were not affected (4.72 +/- 0.6 mm vs 4.45 +/- 0.8 mm, p > 0.05). After induction of diabetes fetal loss and malformation rates were significantly higher in control embryos (6.0% vs 23.8% and 8.4% vs 16.5%, respectively). Transgenic embryos were practically unaffected by diabetes and showed fetal loss and malformation rates of 5.9% and 4.4%, respectively, after induction of diabetes. CONCLUSIONS: Elevated levels of copper zinc superoxide dismutase, a key enzyme in the metabolism of free oxygen radicals, elicit a protective effect against diabetes-associated embryopathy.

Analysis of Variance↗
PubMed1995

Aortic distensibility in normotensive, untreated and treated hypertensive patients.

BACKGROUND: Compared with normotensive subjects, untreated hypertensive patients show a decrease of their aortic distensibility. Whether antihypertensive treatment, by reducing blood pressure and changing functional and/or structural abnormalities of the arterial wall, may prevent or reverse the arterial damage due to the accelerated ageing process remains unclear. The objective of the present study was to determine, using a cross-sectional approach, whether aortic distensibility as measured by pulse wave velocity, in treated hypertensive patients whose diastolic blood pressure had been normalised for several months, was significantly improved over that of untreated hypertensive patients. METHODS: Carotid femoral pulse wave velocity was measured in 124 normotensive subjects and 388 hypertensive patients. The latter group included 164 treated patients with well controlled diastolic blood pressure and 224 untreated hypertensive subjects. The three groups did not differ in other cardiovascular risk factors. RESULTS: In each group there was a significant relationship between age and pulse wave velocity. When compared with untreated hypertensives, treated hypertensives with well controlled diastolic blood pressure had significantly lower blood pressure and pulse wave velocity according to age. However, although diastolic blood pressure of well controlled hypertensives was not significantly different from that of normotensive subjects, the aortic distensibility of the controlled hypertensives remained reduced showing two characteristics: a faster increase in pulse wave velocity with age and a negative relationship with HDL-cholesterol. CONCLUSION: These results suggest that long-term antihypertensive treatment and control of blood pressure using only diastolic blood pressure criteria may not fully reverse arterial alteration associated with hypertensive vascular disease.

Adolescent↗
PubMed1994

Overexpression of liver-type phosphofructokinase (PFKL) in transgenic-PFKL mice: implication for gene dosage in trisomy 21.

The human liver-type subunit of the key glycolytic enzyme, phosphofructokinase (PFKL), is encoded by a gene residing on chromosome 21. This chromosome, when triplicated, causes the phenotypic expression of Down's syndrome (trisomy 21). Increased phosphofructokinase activity, a result of gene dosage, is commonly found in erythrocytes and fibroblasts from Down's syndrome patients. We describe the construction of transgenic mice overexpressing PFKL for use as a well-defined model system, in which the effects of PFKL overexpression in various tissues, and throughout development, can be studied. Mice transgenic for a murine PFKL 'gene cDNA' hybrid construct were found to overexpress PFKL in a tissue-specific manner resembling that of the endogenous enzyme. Although unchanged in adult brain, PFK specific activity was found to have been almost doubled in brains of embryonic transgenic-PFKL mice, suggesting that the extra copies of the PFKL gene are expressed during the developmental period. This pattern of overexpression of PFKL in brains of transgenic-PFKL mice suggests that gene-dosage effects may be temporally separated from some of their consequences, adding an additional layer of complexity to the analysis of gene dosage in trisomy 21.

Aging↗
PubMed1994

Isolation, chromosomal localization, and sequence analysis of human chromosome 21 zinc finger domains.

The zinc finger element is a conserved motif among a group of proteins involved in binding to nucleic acid. This motif has been detected in many regulatory factors and is highly represented in the human genome. To investigate the presence of zinc-finger-encoding genes on human chromosome 21, chromosome-specific libraries were screened with an oligodeoxynucleotide probe representing the conserved H-C link region between adjacent fingers. Three distinct genomic clones, designated ZF21-1, ZF21-2, and ZF21-3, were isolated and mapped to the long arm of chromosome 21 as well as to the heterochromatic short arm of several other chromosomes. DNA sequence analysis has shown that these genomic clones contain multiple zinc finger elements of the Kruppel type with only partial similarity to other known zinc finger genes. However, in each clone, few fingers were degenerated; they contain inframe stop codons and frameshifts that would preclude their translation. It seems therefore, that these chromosome 21 zinc finger sequences are not parts of functional genes. Nevertheless, the possibility that these domains are transcribed, and thus might have a regulatory role, is considered.

Animals↗
PubMed1994

Prevalence of left ventricular systolic dysfunction in Duchenne muscular dystrophy: an echocardiographic study.

The prevalence and hemodynamic consequences of regional wall motion abnormalities (RWMA) were evaluated in 84 advanced-stage Duchenne muscular dystrophy (DMD) patients who underwent echocardiographic and systolic time interval (STI) examination. A satisfactory echocardiogram was obtained in 72 patients who were divided into two groups: group I (33 patients) had normal wall motion or minor changes, and group II (39 patients) had akinetic and/or dyskinetic areas. In group II, 15 patients had ventricular dilation; 8 of the 15 had a history of cardiac failure and 4 died during the study. Wall motion index (WMI), end-diastolic volume (EDV), and STI values increased significantly from group I to group II. In the whole group, a strong correlation was found between WMI and STI ratios. This study demonstrates a high prevalence of RWMA and supports the viewpoint that RWMA, consequences of the myopathic process, result in progressive left ventricular dilation, heart failure, and cardiac death.

Adolescent↗
PubMed1994

Prevalence of hepatitis B virus markers among hospital personnel in Israel: correlation with some risk factors.

During 1986-1987, 480 employees of the Tel-Aviv Medical Center were screened for hepatitis B virus (HBV) markers as a preliminary step in a vaccination campaign. One hundred and seventeen (24.4%) had evidence of previous infection, including nine (1.9%) carriers. The effect of potential risk factors on seropositivity was evaluated by multiple logistic regression analysis, which enabled assessment of the individual contribution of each risk factor under the specific environmental conditions. The following risk factors were found to influence seropositivity: origin from Third World countries as opposed to the Western World, employment as sanitary workers, age over 40 years, and history of accidental needle punctures. In the heterogeneous Israeli population, hospital workers had a relatively high prevalence of HBV markers, probably resulting from occupational exposure.

Adult↗
PubMed1994

Protein kinase C (PKC) level is increased in PC12 cells overexpressing transfected liver-type phosphofructokinase.

PC12 cells which overexpress transfected liver-type phosphofructokinase (PFKL) have previously been described as a model system for PFKL overexpression in Down's syndrome and have been shown to perform glycolysis at enhanced rates. Here we report that levels of protein kinase C (PKC) in PC12-PFKL cells were almost doubled, as estimated from in vitro activity and phorbol ester binding experiments and from an increase found in PKC-alpha mRNA levels. Most of the added PKC was found to be associated with the cellular membrane while the cytoplasmic levels of PKC were barely increased. The steady-state levels of 1,2-sn-diacylglycerol in PC12-PFKL cells were found to be unaltered, suggesting that enhanced glycolysis in these cells did not influence PKC by altering the amounts of this compound. PFKL is one of several genes known to be overexpressed in Down's syndrome. Upregulation of PKC due to PFKL overexpression could result in widespread disturbances of gene expression and play a part in causing some of the many symptoms of the disease.

Animals↗
PubMed1993

A first instance of human philophthalmosis in Israel.

Conjunctivitis due to the trematode Philophthalmus in a 13-year-old Israeli girl is described. A single worm, probably a mature Philophthalmus palpebrarum, was detected on the palpebral conjunctiva of the upper eyelid of the right eye. Removal of the worm resulted in rapid abatement of the ocular symptoms. This is the first documentation of human philophthalmosis in Israel.

Adolescent↗
PubMed1993

Teaching bedside interviewing skills in a social work training program.

Teaching interviewing skills has become a permanent feature of the training of social workers, although no standardization exits for interview training. At a learning center established through a collaborative effort between Haifa University and the Kupat Holim, an effective program for teaching bedside interviewing skills was established.

Adult↗
PubMed1991

Maintenance of blood pressure control in elderly hypertensives on ketoprofen.

In elderly patients, nonsteroidal anti-inflammatory drugs (NSAIDs) are often used concomitantly with antihypertensive agents. It is therefore important to assess the potential for interactions between NSAIDs and these agents. In a double-blind, placebo-controlled study, 40 elderly hypertensive patients treated with acebutolol or atenolol, together with frusemide, were randomized to receive either ketoprofen, 200 mg/day (50 mg q.i.d.), or matching placebo for 7 days. Arterial blood pressure and heart rate were monitored for a 24-hour period at baseline and at the end of treatment. Standard sphygmomanometric measurements of blood pressure and heart rate were conducted twice a day during the study. No clinically significant side effects or blood pressure or heart rate alterations were observed during the trial. The results indicate that ketoprofen does not interfere with blood pressure control in elderly hypertensive patients being treated with a combination of beta-blockers and diuretics.

Acebutolol↗
PubMed1990

Traumatic central retinal artery occlusion.

A healthy 6-year-old boy with a clinical picture of central retinal artery occlusion (CRAO) of his left eye is presented here. The underlying cause was a trauma to the boy's left cheek some 6 months earlier. Possible pathophysiological mechanisms are discussed. To the best of our knowledge, the late onset of traumatic CRAO has not yet been reported in the literature.

Blindness↗