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Biomedical subjects

Y Melamed

Publications and source records attributed to Y Melamed.

At least 55 records · Page 3Linked to original sources
PubMed1997

Insight and competence to consent to psychiatric hospitalization.

Informed consent and insight are among the most important issues in medical treatment, especially for psychiatric patients. In this study, we examined the competence to consent to psychiatric hospitalization of 113 psychiatric patients who were voluntarily admitted to a mental hospital in various psychotic states and compared it with their insight. We found a significant correlation between the patients' competence and insight into their illnesses. There is a discussion of the problematic issues of informed consent, competence and psychosis and the importance of insight in the context of mental illness.

Adult↗
PubMed1996

Nonspecific vertigo with normal otoneurological examination. The role of vestibular laboratory tests.

Vestibular laboratory tests are not generally necessary in the diagnosis of patients with a clear description of vertigo accompanied by positive otoneurological examination findings. The purpose of the study was to investigate the role of conventional vestibular laboratory tests in the diagnosis of patients complaining of nonspecific vertigo, despite their having a documented normal otoneurological examination. The results of the standard electronystagmography (ENG) and sinusoidal harmonic acceleration (SHA) tests of 52 patients referred for ambulatory vestibular laboratory tests due to a nonspecific illusion of movement, but with a normal otoneurological examination, were reviewed. Abnormalities were found in the vestibular tests of 35 patients (67 per cent), 22 of whom (63 per cent) were finally diagnosed as having a unilateral peripheral vestibular lesion, and 13 (37 per cent) benign positional vertigo. These results suggest that a high percentage of patients with nonspecific vertigo and a normal otoneurological examination probably suffer from peripheral vestibular dysfunction, which can be objectively documented by the ENG and SHA tests.

Adult↗
PubMed1996

The impact of the Gulf War on the mental health of schizophrenic patients.

The Gulf War, which took place during January-February 1991, strongly affected the lives of Israeli civilians. The missiles that landed on the home front were a threat to the entire civilian population, thus differentiating the Gulf War from prior Israeli wars (Danon and Shemer 1991). This was similar to the London blitz during World War II (Scoville 1942).

Acute Disease↗
PubMed1995

Gas embolism complicating obstetric or gynecologic procedures. Case reports and review of the literature.

Gas embolism is a rare life-threatening complication of obstetric or gynecologic procedures, arising as a result of gas bubbles being introduced into the circulation via severed blood vessels. Extensive brain damage and acute cardiovascular collapse will lead to a fatal outcome. A favourable outcome depends on early diagnosis and prompt treatment. Hyperbaric oxygenation, which reduces bubble size and increases the supply of oxygen to hypoxic tissues, is the definitive treatment for gas embolism. We report four cases of gas embolism complicating obstetric or gynecologic procedures which were treated at the Israel Naval Medical Institute followed by an updated review of the literature.

Abortion, Induced↗
PubMed1995

Salvage of the severely injured limb in children: a multidisciplinary approach.

Massive trauma to a limb, even in young children, may lead to loss of viability and function. A combination of open fracture with vascular, crush, and avulsion injury resulting in acute peripheral ischemia may place the extremity at risk of necrosis and imminent amputation. We suggest a combined, multidisciplinary approach that includes initial vascular repair and fractures fixation, with early institution of hyperbaric oxygen therapy.

Blood Vessels↗
PubMed1995

Oxygen diving-induced middle ear under-aeration.

Middle ear negative pressure and effusions have been described after oxygen diving. The prevalence, dynamics and pathophysiology of this phenomenon are not clear, and were hence investigated in the present study. Thirty-four oxygen divers with normal otoscopic and tympanometric evaluation participated in the study. The subjects' symptoms were documented, and pneumatic otoscopy and tympanometry were repeated immediately after the completion of a 3 h, 15 feet oxygen dive, and 7 h later on awakening from the night's sleep. Most divers had positive otoscopic findings the morning after the dive, all of which cleared within 4 h of rising. A significant decrease was observed in average middle ear compliance (p = 0.0463, one way ANOVA), and an increase was found in the number of ears with tympanic compliance less than 0.3 ml (p = 0.0001, Kruskal-Wallis non-parametric ANOVA). In addition, 14.7% of the ears had type C, and 27.9% type B tympanograms the morning after the dive (p = 0.0001 chi2). The generalized nature of oxygen-induced middle ear under-aeration, combined with the dynamics of the symptoms and signs observed, make middle ear barotrauma, tympanic cavity oxygen absorption, and middle ear epithelial oxygen toxicity all unlikely explanations. The observed phenomenon and its dynamics might stem from a reversible derangement in a middle ear chemoreceptor reflex arch, which has recently been suggested as regulating middle ear aeration.

Acoustic Impedance Tests↗
PubMed1995

Salutary consequences of oxygen therapy on the long-term outcome of hemorrhagic shock in awake, unrestrained rats.

Decreased oxygen delivery and cellular hypoxia are major factors in the pathophysiology of shock. We studied the effects of 100% O2 at 0.1 and 0.3 MPa (1 and 3 atm abs) in severe hemorrhagic shock in awake, unrestrained rats. Shock was induced by withdrawing 50% of the total blood volume within 120 min. Blood pressure, heart rate, and the electroencephalogram (EEG) were recorded during the first 6 h of the protocol. The animals were observed for 7 days. The shock protocol resulted in 60 and 90% mortality after 1 day and at the end of 7 days, respectively. A single 90-min exposure to O2 at 0.1 and 0.3 MPa, which was started 30 min after bleeding, maintained mean arterial blood pressure at significantly higher values compared to untreated controls throughout the exposure period (P < 0.05). Oxygen therapy at both doses also improved the long-term survival rate and survival time significantly (P < 0.01). No clinical or EEG sign of CNS O2 toxicity was detected in O2-treated animals. Our results indicate that O2 given alone after severe bleeding exerts a beneficial effect on the long-term outcome of hemorrhagic shock in awake, unrestrained rats.

Animals↗
PubMed1994

[Hyperbaric oxygen for hydrogen sulfide poisoning].

Hydrogen sulfide (H2S) is a toxic gas produced in decaying substances containing organic sulfur. Exposure to the gas causes severe disturbances in the central nervous and respiratory systems. The mechanism of toxicity is disruption of the electron transport chain in mitochondria, resulting in intracellular hypoxia. Treatment of H2S poisoning includes mechanical ventilation with 100% oxygen and immediate administration of sodium nitrate. Treatment with hyperbaric oxygen (HBO) has been studied in animal models, and has also been used in a number of patients. However, the clinical effectiveness of this mode of therapy has not been clearly proven. Having recently treated a case of H2S poisoning, we suggest HBO to reduce mortality.

Humans↗
PubMed1994

[Attitudes of courts, physicians and psychiatric committees to court-ordered psychiatric hospitalization].

Legal responsibility for the mentally ill has long been a dilemma. Public opinion with regard to the current law, which holds that the mentally ill are not responsible for their actions, is divided. We assessed 30 cases of psychiatric patients committed by court order following a criminal act. No relation was found between the nature of the transgression and the nature or seriousness of the psychiatric disorder. Interestingly, those who committed the more serious crimes, such as murder, usually had committed fewer criminal acts in the past. The functioning of the psychiatric committees in charge of releasing patients committed by court order has improved substantially under the new law for the treatment of the mentally ill. They now assess patients with considerably greater frequency. The reports to the courts of examining physicians tend to be general, with little attempt to differentiate ability to stand trial and responsibility for actions. On the other hand, treating physicians relate mainly to the patient's illness, rather than to the crime for which he was committed.

Attitude↗
PubMed1994

Hyperbaric oxygen for perianal Crohn's disease.

Perianal involvement in Crohn's disease is common (< or = 50%), distressing, and frequently refractory to treatment. Clinical features include painful induration and stenosis, discharging fistulas, and fissures. The pathogenesis of these lesions is unclear, but local ischemia and secondary anaerobic infection may play a role. Following three sporadic reports of successful treatment with hyperbaric oxygen (HBO), we undertook a trial of this method in 10 patients with refractory perianal disease. These patients' perianal Crohn's disease had not responded to treatment that included local medications, salicylates, corticosteroids, metronidazole, or 6-mercaptopurine were treated. Treatment was administered in a hyperbaric chamber at a pressure of 2.5 atm absolute. Each session lasted 90 min, and each course consisted of 20 daily sessions. Complete healing occurred in 5 patients after one to two courses. In an additional 2, after three courses, 1 patient improved but did not heal, and 2 did not improve. No adverse effects were noted by any of the 10 patients. Follow-up of 18 months did not reveal any recurrence. These preliminary results confirm that HBO therapy is a safe and efficient therapeutic option for perianal Crohn's disease.

Adult↗
PubMed1994

Oligodontia, short stature and small head circumference with normal intelligence.

Complete absence of third molars and mandibular permanent second molars is reported in a 19-year-old female, with occipito-frontal head circumference and height at the 3rd centile. The patient's intelligence, appearance and physical examination were normal. Direct count of the patient's sweat pores in different areas of the palms and digits was normal. Microcephaly, short stature and normal intelligence have been reported in two families as a distinct autosomal dominant syndrome. To the best of our knowledge, oligodontia, in addition to these findings, has not been previously reported.

Adult↗
PubMed1994

Multiple supernumerary teeth (MSNT) and Ehlers-Danlos syndrome (EDS): a case report.

Familial occurrence of supernumerary teeth is reported in a father and his son. While the father had only one supernumerary tooth in the maxillary premolar region, his son had 8 unerupted supernumerary teeth. In addition, both patients had joint hypermobility and stretchable skin, typical of EDS syndrome type III. To the best of our knowledge, the association of supernumerary teeth with Ehlers-Danlos syndrome has never been previously reported. Single supernumerary teeth (SSNT) are most commonly found in the maxillary anterior region, whereas multiple supernumerary teeth prevail in the mandibular premolar region. We suggest that the aetiology of multiple supernumerary teeth may be different from that of single supernumerary teeth.

Adult↗
PubMed1994

Beta-carotene and CNS oxygen toxicity in rats.

Beta-carotenes are reported to be potent free radical quenchers, singlet oxygen scavengers, and lipid antioxidants. Oxygen free radicals that are produced in excess during exposure to oxygen at high pressures and overwhelm the body's normal antioxidant defense systems seem to mediate the hyperoxic insult. We decided to test the possible protective effect against central nervous system oxygen toxicity of a natural beta-carotene composed of equal amounts of the all-trans and 9-cis isomers obtained from the unicellular halotolerant alga Dunaliella bardawil. Rats implanted with chronic cortical electrodes for continuous electroencephalogram monitoring were fed on ground commercial food enriched with natural beta-carotene (1 g/kg diet). On completion of 1 wk of the diet, the rats were exposed to 0.5 MPa oxygen and then their livers were removed for beta-carotene and vitamin A analysis. A significant increase was noted in the latent period preceding oxygen seizures in the group of rats in which the diet was supplemented by natural beta-carotene compared with rats given a normal diet (38.5 +/- 3.4 vs. 16.8 +/- 1.8 min; P < 0.05). Further experiments are required to evaluate the potential benefit of supplementing the diet of divers and patients exposed to high pressures of oxygen with the beta-carotene-rich D. bardawil.

Animals↗
PubMed1994

Effect of hyperbaric oxygen on tissue distribution of mononuclear cell subsets in the rat.

In a previous study we found a significant temporary decrease in the ratio of CD4/CD8 (helper, inducer/suppressor, cytotoxic) T lymphocytes in the peripheral blood of healthy human volunteers after exposure to a single commonly used profile of hyperbaric oxygen (HBO). The transient nature of the changes suggested redistribution of T-cell subsets. The purpose of the present study was to verify such a redistribution and to locate possible target organs in an animal model. A single exposure of rats to HBO (0.28 MPa) induced a highly significant rapid decrease in the CD4/CD8 ratio in peripheral blood count (P < 0.0001), confirming our previous findings in humans. HBO also induced a significant increase in the CD4/CD8 ratio in the lungs and lymph nodes (P < 0.001) and a significant decrease in the ratio in the spleen (P < 0.01). Furthermore, exposure to HBO induced a significant increase in T cells bearing surface interleukin-2 receptors in the blood, spleen, lungs, and lymph glands (P < 0.001) and a significant decrease in T cells expressing alpha beta-receptors in the lungs (P < 0.001) and lymph glands (P < 0.05). Our findings suggest rapid T-cell activation after a brief exposure to HBO, with shifts of CD4 and CD8 subsets and variations in T-cell receptor type. These rapid changes in the parameters of cell-mediated immunity may represent the activation of protective mechanisms against the toxic effect of oxygen or the early stages of pulmonary oxygen toxicity.

Animals↗
PubMed1994

Effect of cinnarizine in the prevention of seasickness.

In a double-blind, placebo-controlled study, we evaluated the effect of two different doses of cinnarizine in the prevention of seasickness in very rough seas. We divided 95 healthy male subjects into 3 groups which received: cinnarizine 50 mg, cinnarizine 25 mg, and placebo. Seasickness susceptibility and severity were evaluated by a standard questionnaire concerning the subject's condition on previous voyages (seasickness susceptibility), and the subject's condition immediately after a 4-6-h voyage in very rough seas with 3.5 m waves (seasickness severity). Possible side effects of the drug were also evaluated by filling in a further questionnaire. Of the 31 subjects who received cinnarizine 50 mg, 65% felt better during the present voyage than on previous voyages, compared to 41% of the 32 subjects who received cinnarizine 25 mg and 31% of the 32 who received placebo. A significant difference (p < 0.05) was found between the cinnarizine 50 mg and placebo groups, while cinnarizine 25 mg was no more effective than placebo. No notable side effects were found for any drug group. In conclusion, cinnarizine 50 mg was found to be effective in the prevention of seasickness in rough seas.

Adolescent↗