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Biomedical subjects

G Eshel

Publications and source records attributed to G Eshel.

At least 55 records · Page 3Linked to original sources
PubMed1991

Role of dopamine and GABA in the control of motor activity elicited from the rat nucleus accumbens.

The application of 1.2 and 12.0 micrograms/side of the GABAA receptor agonist 3-aminopropane sulphonic acid bilaterally into the nucleus accumbens (Acb) of rats nonsignificantly depressed locomotor activity as assessed in automated Animex activity cages, while the highest dose (60 micrograms/side) significantly stimulated activity. The GABAA receptor antagonists picrotoxinin (0.0625 and 0.125 micrograms/saide) and bicuculline (0.895 micrograms/side) produced forward locomotion around the cage accompanied by a number of other behaviours. The GABAB agonist baclofen (0.023 and 0.092 micrograms/side) induced a short-lasting (18 min) locomotor depression. None of the GABAB antagonists tested (2-hydroxysaclofen 2.6 micrograms/side, two novel beta-(benzo[b]furan) analogues of baclofen 9G or 9H each 6.8 micrograms/side, 4-aminobutylphosphonic acid 1.32 micrograms/side and phaclofen 0.535 and 2 micrograms/side) significantly affected locomotor activity. In rats pretreated with reserpine and alpha-methyl-p-tyrosine, picrotoxinin (0.0625 and 0.125 micrograms/side) did not significantly alter locomotor activity. Furthermore, when picrotoxinin (0.0625 micrograms/side) was combined with either the selective dopamine (DA) D1 agonist SKF38393 or the selective D2 agonist quinpirole, no significant alteration in locomotor function occurred. When SKF38393 and quinpirole were coadministered, significant stimulation occurred which was further enhanced by the addition of picrotoxinin. It is concluded that GABAA receptors, together with D1 and D2 receptors, play a major role in modulating the control of motor function by the Acb of rats.

Animals↗
PubMed1991

The iron chelator desferrioxamine (Desferal) retards 6-hydroxydopamine-induced degeneration of nigrostriatal dopamine neurons.

A selective increase in content of iron in the pars compacta of the substantia nigra has been implicated in the biochemical pathology of Parkinson's disease. Iron is thought to induce oxidative stress by liberation of oxygen free radicals from H2O2. Because 6-hydroxydopamine (6-OHDA) is thought to induce nigrostriatal dopaminergic neuronal lesions via metal-catalyzed free radical formation, the effect of the iron chelator desferrioxamine was investigated on 6-OHDA-induced dopaminergic neuron degeneration in the rat. Intracerebroventricular injection of 6-OHDA (250 micrograms) caused a 88, 79, and 70% reduction in striatal tissue content of dopamine (DA), 3,4-dihydroxyphenylacetic acid, and homovanillic acid (HVA), respectively, and a 2.5-fold increase in DA release as indicated by the HVA/DA ratio. Prior injection of desferrioxamine (130 ng i.c.v.) resulted in a significant protection (approximately 60%) against the 6-OHDA-induced reduction in striatal DA content and a normalization of DA release. Dopaminergic-related behavioral responses, such as spontaneous movements in a novel environment and rearing, were significantly impaired in the 6-OHDA-treated group. By contrast, the desferrioxamine-pretreated rats exhibited almost normal behavioral responses. The ability of iron chelators to retard dopaminergic neurodegeneration in the substantia nigra may indicate a new therapeutic strategy in the treatment of Parkinson's disease.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1990

Recurrent seizures in children with Shigella-associated convulsions.

Fifty-five children with Shigella-associated convulsions were followed prospectively to investigate their risk of subsequent febrile or nonfebrile seizures. The duration of the follow-up period was between 6.9 and 14.1 years (9.7 +/- 3.1 years). No case of nonfebrile seizures and only 2 cases (3%) of subsequent febrile seizures were observed during this period. We conclude that although febrile and Shigella-associated convulsions share many clinical features, the natural history of these two conditions seems to be distinctly different. Shigella-related convulsions are not associated with an increased incidence of subsequent febrile or nonfebrile convulsions.

Child↗
PubMed1990

Hyperthermia-induced cardiac arrest in dogs and monkeys.

The pattern of dying from immersion hyperthermia was documented in 8 dogs, 9 rhesus monkeys and 12 pigtail monkeys. Under light general anesthesia and spontaneous breathing, the animals were immersed into water of 45 degrees C, which was subsequently adjusted to control brain (parietal epidural) temperature at 42 +/- 0.5 degrees C. Transient initial hypertension, tachycardia, tachypnea and hypocarbia were followed by progressive hypotension with decreasing central venous pressure and pulmonary artery occlusion pressures (measured in three dogs only), bradycardia and bradypnea. Cardiac arrest occurred in the dogs after immersion of 288 +/- 66 min and more rapidly (P less than 0.02) in the rhesus monkeys (at 137 +/- 75 min) and pigtail monkeys (at 178 +/- 26 min). EEG silence occurred in the monkeys at MAP 40 mmHg and in the dogs at MAP 25 mmHg. Cardiac arrest occurred in form of sudden ventricular fibrillation (2/5 dogs, 2/9 rhesus monkeys, 3/12 pigtail monkeys), or later in electromechanical dissociation leading to electric asystole (3/5 dogs, 7/9 rhesus monkeys, 9/12 pigtail monkeys). The mean blood glucose levels decreased to less than 30 mg/dl (P less than 0.002), whereas hematocrit, serum osmolality, lactate and potassium levels increased. Necropsies revealed macroscopic petechial hemorrhages in all extracerebral organs, but not in the brain. There was no gross evidence of cerebral edema. Death seemed to be the result of primary cardiovascular failure leading to secondary (ischemic) cerebral failure (EEG silence) and apnea, which coincided with pulselessness.

Acid-Base Equilibrium↗
PubMed1990

Alpha 1 (but not alpha 2)-adrenoceptor agonists in combination with the dopamine D2 agonist quinpirole produce locomotor stimulation in dopamine-depleted mice.

Mice were premedicated with reserpine and alpha-methyl-p-tyrosine to deplete stores of dopamine (DA) (and other neurotransmitters) and to stop DA (and noradrenaline (NA] synthesis. In DA-depleted mice, the mixed alpha 1/alpha 2 agonist clonidine potentiated locomotor stimulation induced by a low dose of apomorphine as measured in automated activity cages. Clonidine and the slightly alpha 1-selective agonist ST587, but not ST91, an alpha-agonist which does not readily cross the blood brain barrier, produced marked stimulation when combined with the selective D2 agonist quinpirole. The D1 -selective agonist SKF38393 also produced marked excitation when combined with quinpirole. All the selective agonists, bar quinpirole which in some cases produced a significant locomotor stimulation, were relatively inactive when given alone. A "blind" observational analysis of the animals challenged with clonidine plus quinpirole indicated an increase in sniffing, rearing and shaking behaviour. In contrast, observation of the animals challenged with SKF38393 plus quinpirole indicated increased sniffing, rearing and biting and, in one case, increased grooming behaviour. Clonidine did not produce excitation (in automated cages) when combined with the selective D1 agonist SKF38393. The excitation produced by clonidine plus quinpirole was blocked by the selective D2 antagonist raclopride but not by the selective D1 antagonist SCH23390. The stimulation was also blocked by the alpha 1 antagonist prazosin but not by the alpha 2 antagonists idazoxan or yohimbine. Biochemical analysis in the striata of mice challenged with clonidine plus quinpirole did not provide any obvious biochemical basis for the behavioural interaction. It is concluded that alpha 1 receptor agonists in combination with D2 DA agonists can produce marked stimulation in DA depleted mice.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1990

Hereditary chondrocalcinosis in an Ashkenazi Jewish family.

A hereditary chondrocalcinosis is described for the first time in an Ashkenazi Jewish kindred. Of 34 family members in five generations, seven had medical history suggesting the disease. Five of 25 members of generations III-V had direct evidence for their disease. Characteristically, symptoms started at a fairly early age (third decade) while radiological evidence of chondrocalcinosis was delayed to the fourth decade. Joints commonly affected were knees, wrists, and elbows. The course was chronic with acute, exercise induced exacerbations.

Adult↗
PubMed1990

Acute gastroenteritis due to double infection with enteropathogenic Escherichia coli or Salmonella and another bacterial pathogen.

Two enteric bacterial pathogens were concomitantly isolated from the feces of 18 infants less than 6 months of age admitted to the Assaf Harofeh Medical Center over a 7-year period. In all but two patients stool cultures grew enteropathogenic Escherichia coli, six of serogroup 0119. The other organisms cultured were Shigella, Salmonella, Campylobacter jejuni and Aeromonas hydrophila. The usual clinical presentation was diarrhea, dehydration and vomiting of acute onset, and low grade fever. Patients with gastroenteritis due to a single agent compared with multiple pathogens had a milder course of disease, a milder degree of dehydration and acidosis, a lesser need for i.v. fluid treatment and shorter hospitalization.

Academic Medical Centers↗
PubMed1989

Neurogenic bladder due to herpes zoster infection in an infant.

A case is presented of Herpes zoster (HZ) infection in a 2.5-month-old infant with the added complication of a neurogenic bladder. The patient's mother suffered from varicella during the 18th week of pregnancy. The patient had a typical herpetic rash at the age of 2.5 months, and developed constipation and a neurogenic bladder. While the constipation improved, bladder atonicity led to hydroureters necessitating bilateral ureterostomies. Urinary tract involvement of HZ is well known in adults and is reversible. To our knowledge this is the first report of such a complication of HZ infection in infants.

Chickenpox↗
PubMed1989

Elevated serum creatine kinase. Following febrile seizures.

Serum creatine kinase (CK) was determined in 52 children admitted following an episode of febrile convulsions. Enzyme levels correlated with the estimated duration of the seizure. Twenty-four hour values were significantly higher than those observed 1 hour after the convulsive episode. Serum CK levels are frequently used for diagnostic purposes, so the questionable validity of this test when drawn after a convulsive episode must be considered.

Age Factors↗
PubMed1989

Chorea associated with systemic lupus erythematosus in children. A case report.

In the past most cases of childhood chorea were related to rheumatic fever and were treated appropriately. With the decrease in the incidence of rheumatic fever less common etiologies of chorea should be investigated. This report demonstrates the difficulties of distinguishing between chorea associated with rheumatic fever and chorea associated with systemic lupus erythematosus.

Child↗
PubMed1988

Acute rheumatic fever in the young: changing prevalence and pattern.

Acute rheumatic fever (ARF) is rare in young people. A group of 28 patients is described who were hospitalized during the years 1960-1984. Patients were divided into two groups: children who were admitted between 1960 and 1966 and those admitted between 1966 and 1984. The annual incidence of ARF declined from 1.17 to 0.44 cases per 10,000 population at risk. The incidence of arthritis declined in parallel to the decrease in number of children presenting with ARF, whereas the incidence of carditis remained the same.

Acute Disease↗
PubMed1988

Peripheral facial nerve paralysis in children: the value of routine diagnostic work-up studies.

Acute facial nerve paralysis is a relatively common pediatric disorder. Idiopathic facial nerve palsy (Bell's palsy) has to be distinguished from other etiologies. Retrospective review of the results of routine diagnostic work-up studies of our patients, failed to reveal any clinically significant abnormalities and did not provide more data as far as etiology or indication for management. Significant history and positive findings on physical examination should direct the physician towards specific diagnostic procedures.

Adolescent↗
PubMed1988

Phytobezoar following raisin ingestion in children.

A rare childhood phytobezoar is reported in a two-and-one-half-year-old male infant with bowel obstruction, following raisin ingestion. Complete recovery followed conservative treatment. It was preceded by passage of a large, bulky stool, containing numerous undigested, fluid-filled raisins.

Bezoars↗
PubMed1987

Cardiac injuries caused by blunt chest trauma in children.

Two illustrative cases with different features of cardiac injury caused by blunt chest trauma are described. The first patient had mild and obscure symptoms, detected on physical examination, and required observation only. The second patient had acute pericardial tamponade, necessitating surgical treatment. We present the different medical procedures that should be taken into consideration in management of such cases, although continuous monitoring, repeated physical examination, electrocardiograms, chest x-rays, and echocardiography proved sufficient in managing our two children. It is important that physicians who provide care to children suffering from blunt chest trauma have increased awareness of possible cardiac injuries.

Child↗
PubMed1987

Tachycardia and heart failure after ritual circumcision.

Four newborn babies developed acute heart failure a few hours after circumcision at 8 days. During this procedure, a sponge soaked in epinephrine was applied to the circumcision site and left there for several hours. Treatment was with digoxin and diuretics and signs of heart failure disappeared within 24-72 hours.

Circumcision, Male↗