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Biomedical subjects

Y Shapira

Publications and source records attributed to Y Shapira.

At least 163 records · Page 9Linked to original sources
PubMed1992

Brain edema and neurologic status following head trauma in the rat. No effect from large volumes of isotonic or hypertonic intravenous fluids, with or without glucose.

Disagreement exists regarding the need to restrict the administration of fluid and glucose following head injury to prevent cerebral edema and neurologic deterioration. We examined whether blood osmolality and glucose, neurologic outcome, and the development of brain edema following head trauma were altered by intravenous infusion of large volumes of isotonic or hypertonic fluids that contained or did not contain glucose. Fifty-five rats that survived ether anesthesia and closed head trauma (delivered using a weight drop device) were assigned to one of five groups. In the first group no fluid was infused. In the second group minimal volumes of saline were infused during placement of a jugular vein catheter. In the three remaining groups 10 ml.kg-1.h-1 of either total parenteral nutrition (TPN) (glucose 25%, amino acids 4.25%, 40 mEq/l sodium and 40 mEq/l potassium, 1935 mOsm/kg), dextrose 5% in 0.45% saline (495 mOsm/kg), or Haemaccel (isotonic plasma expander, 298 mOsm/kg) was infused via the jugular vein. Following head trauma and cannula placement, ether was discontinued. Neurologic severity score at 1 and 18 h after head trauma was used to assess neurologic outcome. A score between 0 and 6 was assigned by an observer who was blinded as to the experimental groups, with 0 representing no neurologic damage and 6 representing severe damage. Specific gravity of brain tissue samples containing gray matter and subcortical white matter from the traumatized and contralateral hemispheres was measured at 18 h after head trauma to determine the development of brain edema. There were no statistically significant differences in neurologic outcome and brain edema between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Electroencephalogram, cerebral metabolic, and vascular responses to propofol anesthesia in dogs.

Previous studies on the cerebral effects of propofol report conflicting results regarding the cerebral metabolic rate for oxygen (CMRO2), cerebral blood flow (CBF), autoregulation of CBF, intracranial pressure, and cerebral perfusion pressure (CPP). The present studies were designed to examine these issues as well as propofol effects on the CBF responses to hypocapnia and on the electroencephalogram (EEG) in a well-known canine model that permits continuous determination of EEG activity, CMRO2, CBF, and cerebrospinal fluid (CSF) pressure. Dogs were studied at normocapnia (n = 6) and at hypocapnia (n = 6) during three doses of propofol (12, 24, and 48 mg kg(-1) h(-1)) and during a combination of propofol and elevated (20-25 mm Hg) CSF pressure. In both groups propofol caused dose-related decreases of EEG power and number of waveforms, CMRO2 (by 25-30%), and CBF (by 73-76%). The cerebral vasoconstrictor response to hypocapnia was preserved at all three doses of propofol. Autoregulation of CBF was preserved at the low and moderate doses of propofol but was impaired at the high dose of propofol (where CPP decreased significantly to approximately 41 +/- 13 mm Hg) and at the high dose of propofol combined with elevated CSF pressure (where CPP decreased significantly to approximately 32 +/- 12 mm Hg). Cerebrospinal fluid pressure decreased (by 33-42%) when the continuous infusion of propofol was begun, but returned to prepropofol values as infusion of propofol continued. The authors conclude that low and moderate doses of propofol decrease EEG activity and CMRO2, causing an associated decrease of CBF and CSF pressure. Autoregulation of CBF and cerebral vascular CO2 reactivity are preserved at these propofol doses. In contrast, high dose propofol significantly decreases CPP, resulting in impaired autoregulation of CBF.

Journal Article↗
PubMed1992

Ketamine decreases cerebral infarct volume and improves neurological outcome following experimental head trauma in rats.

In brain injury, concentrations of extracellular excitatory amino acids are increased and stimulate glutamate receptors in general and the N-methyl-D-aspartate (NMDA)-preferring subtype in particular. That stimulation causes substantial calcium influx, which appears to initiate a cascade of events leading to neuronal death. Blockage of NMDA receptors with specific antagonists or noncompetitive ion channel blockers provides protection against excitatory amino acid-induced neurotoxicity. We previously reported that the NMDA receptor antagonist dizocilpine maleate improved the neurological severity score (NSS) after head trauma in rats. The present study was designed to determine whether ketamine, a NMDA receptor antagonist like dizocilpine maleate, improves neurological outcome following head trauma in rats. Thirty-two male Sprague-Dawley rats (235-250 g) were divided into four groups. Groups A and B were surgically prepared only. Groups C and D were surgically prepared and then a nonpenetrating impact was delivered to the cranium over the left hemisphere. Groups A and C received no treatment. Groups B and D were treated with ketamine, 180 mg/kg i.p., 1 h after head trauma. The NSS was determined at 1, 2, 4, 10, 24, and 48 h following head trauma. After killing at 48 h, cortical slices were taken adjacent to the lesion on the traumatized hemisphere and from comparable sites on the nontraumatized hemisphere to measure the tissue specific gravity and water content. Brains were then placed in 4% formaldehyde and the volume of hemorrhagic necrosis measured 4 days later. Head trauma increased the NSS and, in the traumatized hemisphere, decreased the specific gravity, increased the water content, and caused cerebral infarction. With ketamine, the NSS at 24 and 48 h following head trauma was 7.4 +/- 2.6 and 6.7 +/- 2.6 (mean +/- SEM), respectively, significantly improved compared to the NSS in the untreated group of 12.6 +/- 2.6 and 11.3 +/- 2.6, respectively (p <0.02, Mann-Whitney U test). With ketamine, the volume of hemorrhagic necrosis was 88.0 +/- 23.1 mm, significantly less than that in the untreated group (147.4 +/- 22.4 mm; p <0.05, unpaired t test). The brain tissue specific gravity and water content at 48 h and the rectal temperature at 4 and 48 h after head trauma were not significantly different between treated and untreated groups. It is concluded that in this model of closed cranial impact, ketamine improves neurological outcome and decreases the volume of hemorrhagic necrosis without altering brain edema.

Journal Article↗
PubMed1992

Methylprednisolone does not decrease eicosanoid concentrations or edema in brain tissue or improve neurologic outcome after head trauma in rats.

Methylprednisolone was recently reported to significantly improve motor and sensory function after acute spinal cord injury in patients. Our study was designed to determine whether methylprednisolone exerts a beneficial effect after head injury. Diethyl ether-anesthetized rats were assigned to receive surgery with no cranial impact and no methylprednisolone (group A, n = 13); surgery with no cranial impact and intraperitoneal methylprednisolone (greater than or equal to 60 mg/kg) (group B, n = 8); surgery with cranial impact and no methylprednisolone (group C, n = 8, and group E, n = 8); or surgery with cranial impact and methylprednisolone (greater than or equal to 60 mg/kg) (group D, n = 15, and group F, n = 13). Neurologic severity score was determined at 1, 2, 4, and 24 h (when appropriate) after injury, and brain tissue eicosanoid levels and cerebral edema were determined when the animals were killed (4 h after injury in groups C and D and 24 h after injury in groups E and F). Treatment with methylprednisolone did not improve neurologic severity score or edema formation and did not alter brain tissue levels of prostaglandin E2, thromboxane B2, or 6-keto-prostaglandin F1 alpha at any time period. The authors conclude that methylprednisolone does not exert a beneficial effect on brain tissue edema or functional activity after cranial impact in rats.

Animals↗
PubMed1991

Diagnosis and treatment of primary and recurrent retroperitoneal liposarcoma.

We retrospectively reviewed 16 patients in whom primary retroperitoneal liposarcoma was diagnosed and treated. These patients were classified according to the first definitive surgical procedure employed: complete excision with or without radiotherapy; partial excision followed by radiotherapy; only biopsy of tumor followed by radiotherapy. Distribution of tumors according to histologic type was: well differentiated myxoid type, 10; poorly differentiated myxoid type, 4; and mixed type, 2. The main factor in determining resectability was extent and fixation of tumor to vital structures. Recurrent retroperitoneal disease developed in four patients all of whom underwent secondary intervention. We concluded from our experience that complete surgical excision is the most effective primary therapeutic approach for patients with primary and recurrent retroperitoneal liposarcoma.

Adult↗
PubMed1991

Primary fibromyalgia and the chronic fatigue syndrome.

Thirty-three primary fibromyalgia patients were investigated for chronic fatigue syndrome symptoms. Significant fatigue was reported by 21/33 patients (63.6%), and patients reported various flulike symptoms, yet only 7/33 patients (21.2%) fulfilled criteria for the chronic fatigue syndrome. Only one patient reported painful lymph glands and four patients reported fever. Thus, symptoms of painful glands or fever might serve as clinical indicators, distinguishing between fibromyalgia and the chronic fatigue syndrome.

Diagnosis, Differential↗
PubMed1991

An autosomal recessive form of benign familial neonatal seizures.

We present a consanguineous sibship with benign familial neonatal seizures. The mode of transmission of the disorder in this family seems to be autosomal recessive, which is contrary to the usual autosomal dominant type. Linkage analysis failed to show tight linkage between the disease locus and the autosomal dominant locus assigned to chromosome 20q. We thus conclude that benign familial neonatal seizures is a genetically heterogeneous type of epilepsy.

Chromosomes, Human, Pair 20↗
PubMed1991

Deglutition syncope with coexistent carotid sinus hypersensitivity.

A 63-year-old man had symptomatic deglutition-induced atrioventricular (A-V) block. There was also a coexistent mixed type carotid sinus hypersensitivity presenting as A-V block. No A-V nodal dysfunction was revealed during electrophysiologic studies. The vasodepressor response to carotid massage implies a central vagal hyperresponsiveness, which can also explain the cardioinhibitory responses to swallowing and carotid sinus massage, both possibly unmasked by posterior myocardial infarction.

Blood Pressure↗
PubMed1990

Genetic homogeneity between acute and chronic forms of spinal muscular atrophy.

The childhood-onset spinal muscular atrophies (SMAs) describe a heterogeneous group of disorders that selectively affect the alpha motoneuron. We have shown that chronic childhood-onset SMA (SMA II and III) maps to a single locus on chromosome 5q. Acute SMA (SMA Type I/Werdnig-Hoffmann/severe/infantile) is the main cause of heritable infant mortality. Mapping the acute SMA locus by conventional methods is complicated by the rapidly fatal course of the disease and its recessive mode of inheritance. We present here the typing of four inbred acute-SMA families with DNA markers on chromosome 5q and analysis of these together with acute families from our previous study to demonstrate genetic homogeneity between the acute and chronic forms of SMA. The data indicate that the acute SMA locus maps to chromosome 5q11.2-13.3. Two families seem unlinked to 5q markers, raising the possibility of genetic heterogeneity or disease misclassification within the acute and chronic family sets.

Acute Disease↗
PubMed1990

Muscle involvement in mucolipidosis IV.

A 15-month-old boy, thought to have a congenital myopathy, was subsequently diagnosed as having mucolipidosis type IV, with typical membranous inclusions in muscle fibers. Involvement of skeletal muscle in this lysosomal storage disease may explain the motor delay and hypotonia that are its most common presenting signs.

Conjunctiva↗
PubMed1990

Protective effect of MK801 in experimental brain injury.

The effect of a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, MK801, was studied in a model of closed head injury in rats. Head trauma (HT) was induced over the left cerebral hemisphere by a calibrated weight-drop device. One or 3 h later, MK801 in saline was given i.p. in a single bolus of either 1, 3, or 10 mg/kg. The rats were killed at 4, 24, or 48 h after HT. Cortical tissue samples were taken from the injured zone and from the corresponding region of the contralateral hemisphere and analyzed for specific gravity (SG) by linear gradient columns. The neurological status of the traumatized rats was evaluated by a neurological severity score (NSS) 1 h after trauma and just before death. Pathological evaluation, based on size and severity of the lesion, was performed 24 and 48 h after HT on control and MK801-treated rats. A dose of 3 mg/kg MK801 given 1 h after trauma effectively prevented the reduction in tissue SG only at 24 h. The NSS could not be evaluated at 24 h after trauma because of the sedating effect of the drug. At 48 h posttrauma, however, the drug significantly improved the neurological state of the rats. No significant difference was found in the pathological score between treated and untreated rats. The results demonstrate neuroprotective properties of MK801, as expressed in two different variables--reduced edema formation and improved neurological recovery after HT. These findings support existing evidence that pharmacological intervention with NMDA receptor antagonist after head injury may be of clinical value in the management of head-injured patients.

Animals↗
PubMed1990

Antiproteinuric effect of captopril in a patient with lupus nephritis and intractable nephrotic syndrome.

A 22 year old woman presented with lupus nephritis, hypertension, and intractable nephrotic syndrome. Albumin and furosemide given intravenously was ineffective. Captopril administered in a daily dose of 62.5 mg was associated with a reduction in proteinuria from 28 g/24 hours to 11.5 g/24 hours over 10 weeks, resulting in a weight reduction of 16 kg. This was achieved with relative preservation of renal function. Captopril should be considered in the treatment of intractable proteinuria in patients with lupus nephritis, or when cytotoxic drugs are refused, because of its efficacy and relative safety. Captopril should, however, be used as an adjunct and not as a substitute for standard treatment.

Adult↗