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Biomedical subjects

Z H Rappaport

Publications and source records attributed to Z H Rappaport.

At least 19 recordsLinked to original sources
PubMed2006

Robotics and artificial intelligence: Jewish ethical perspectives.

In 16th Century Prague, Rabbi Loew created a Golem, a humanoid made of clay, to protect his community. When the Golem became too dangerous to his surroundings, he was dismantled. This Jewish theme illustrates some of the guiding principles in its approach to the moral dilemmas inherent in future technologies, such as artificial intelligence and robotics. Man is viewed as having received the power to improve upon creation and develop technologies to achieve them, with the proviso that appropriate safeguards are taken. Ethically, not-harming is viewed as taking precedence over promoting good. Jewish ethical thinking approaches these novel technological possibilities with a cautious optimism that mankind will derive their benefits without coming to harm.

Biomedical Technology↗
PubMed2006

Endovascular treatment of isolated dissecting aneurysm of the posterior inferior cerebellar artery.

BACKGROUND AND PURPOSE: Isolated dissecting aneurysms of the posterior inferior cerebellar artery (PICA) carry a high risk of rebleeding with an associated increased mortality rate. Although rare, they present a therapeutic challenge. Surgical treatment carries a significant risk of neurologic complications, predominantly lower cranial nerve deficits because of the close relationship of the aneurysm with the brain stem and cranial nerves. The purpose of this article is to show that endovascular treatment of dissecting aneurysms of the PICA can be effective and can allow the patient to avoid the complications associated with surgery. METHODS: Six patients (age range, 28-70 years) with dissecting aneurysms of the PICA were treated at our center by endovascular occlusion with Guglielmi detachable coils or glue and followed for up to 30 months. Inclusion of patients in the study was based on careful angiographic assessment of the vascular anatomy and collateral supply of the posterior fossa. When on the basis of the anatomy, potential lack of sufficient collaterals was suggested, a test occlusion was performed to determine the feasibility of an endovascular approach. Four additional cases, which have been described in the literature, were included in the analysis of results. RESULTS: In all patients, the aneurysm was successfully occluded with no apparent procedure-related complications. Follow-up studies showed stable and complete occlusion of the aneurysm in all patients with no long-term neurologic deficits. CONCLUSIONS: Endovascular treatment by aneurysm and parent artery occlusion is a relatively safe and reliable alternative to surgery for isolated dissecting aneurysms of the PICA.

Adult↗
PubMed2002

Surgical treatment of painful spasticity after spinal cord injury.

STUDY DESIGN: There are several conservative methods of painful spasticity treatment. However, conservative methods do not always provide long-term and complete antispastic effects in cases of spinal cord injury with severe painful spasticity. OBJECTIVES: The aim of the present study was to analyse and compare the effectiveness of myelotomy by Bischof II and Pourpre in patients with paraplegia and severe painful spasticity in the late period after spinal cord trauma. SETTING: Spinal Care Unit, Meir General Hospital, Israel. METHODS: Twenty patients had longitudinal T-myelotomy by the Bischof II technique and 20 longitudinal myelotomy en croix (Pourpre). The spasticity was determined by evaluated muscle tone and muscle spasm according to the Ashworth and spasm-frequency scales. The pain was determined by McGill short questionnaire. The results were calculated by the Wilcoxon signed rank test, by Mann-Whitney U-test and Students t-test. Clinical outcomes after myelotomy in-patients with chronic spinal cord injury and painful spasticity were evaluated after 6 months, 5 and 10 year follow-up period. RESULTS: Pain was relieved in all cases. The best motor antispastic effect was achieved after Pourpre myelotomy in 18 of the patients (90%) were evaluated after a follow-up of 6 months, 15 patients (75%) after 5 years, and 11 patients (64.7%) after 10 years. Following Bischof II myelotomy results were classified as good: in 13 patients-(65%) at 6 months; in nine patients (45%) at 5 years and in six patients-(40%) at 10 years. Statistical analysis showed no reliable relationship between the level of Spinal cord lesion (T4-T10) and the type of operation. No instability occurred as a result of antispastic operation in any patient. CONCLUSION: A higher rate of beneficial outcome was achieved after Pourpre myelotomy. We recommend this operation for patients with paraplegia and painful spasticity, who do not have hope of regaining voluntary motor function. However, transections of basic pathways of spasticity are not always sufficient for complete antispastic effects. Good results after the operation may deteriorate in time. Therefore further investigations into the mechanism of the spasticity syndrome in the spinal cord injured patient are required.

Adult↗
PubMed2001

Comparative analysis of the NF2, TP53, PTEN, KRAS, NRAS and HRAS genes in sporadic and radiation-induced human meningiomas.

Irradiation to the head is associated with a significantly increased incidence of meningiomas. Radiation-induced meningiomas morphologically resemble their sporadically arising counterparts; however, they frequently exhibit a more malignant phenotype. Several genes have been shown to carry mutations in meningiomas, with the NF2 gene being most frequently affected. To examine whether the NF2 gene also plays a role in the development of radiation-induced meningiomas, we compiled a series of meningiomas from 25 patients with a history of previous cranial radiation. This series was compared with 21 atypical WHO grade II meningiomas and 15 anaplastic WHO grade III meningiomas, all from patients without a history of prior irradiation. NF2 mutations occurred significantly more often in sporadic atypical and anaplastic than in radiation-induced meningiomas (p < 0.02). In addition, all meningiomas were examined for mutations in the PTEN, TP53, HRAS, KRAS and NRAS genes. Two mutations in the TP53 gene in a sporadic and a radiation-induced tumor were detected. PTEN mutations were observed in 1 anaplastic and 1 radiation-induced meningioma. No structural alterations were seen in the RAS genes. Our data suggest that, while there is a certain overlap in the mutational spectrum, NF2 mutations may not play such a prominent role in the pathogenesis of radiation-induced compared to sporadic meningiomas.

Adult↗
PubMed2001

Comparative genomic hybridization analysis of radiation-associated and sporadic meningiomas.

Ionizing irradiation to the skull is a known risk factor for meningioma development. To gain insight into the molecular mechanisms that underlie radiation-associated meningioma (RAM), we characterized the somatic genetic alterations in 16 RAMs by using comparative genomic hybridization and compared the pattern of alterations with 17 nonradiation-associated meningiomas (non-RAM). Most tumors (29/33;87.9%) displayed at least one DNA copy number alteration, and 11 out of 33 (33%) exhibited four or more changes. The mean number of DNA copy number changes was similar in RAMs (2.4+/-1.9) and in non-RAMs (2.5+/-1.9). The most common DNA losses were noted in chromosome 22 (56.2% in RAM, and 47% in non-RAM) and chromosome 1 (37.5% in RAM and 35.3% in non-RAM), with no significant differences between the two groups. Noteworthy, gain in DNA copy number of chromosomes 8 and 12 was detected in two RAM tumors only. In conclusion, no significant differences were noted between RAMs and non-RAMs regarding the number of genetic changes and the extent and frequency of chromosomes 1 and 22 losses. These preliminary data suggest that the tumorogenic pathways of meningioma formation are similar, regardless of previous skull irradiation.

Adult↗
PubMed2001

Safety of perioperative minidose heparin in patients undergoing brain tumor surgery: a prospective, randomized, double-blind study.

OBJECT: Thromboembolic phenomena (TEPs) continue to be a significant source of morbidity and mortality in patients undergoing neurosurgery. Although the efficacy of low-dose heparin in preventing TEPs in neurosurgical patients is well established, neurosurgeons are reluctant to use it perioperatively because of concern for increased bleeding complications. To clarify this issue, the authors used a prospective, randomized, double-blind design to evaluate the safety of minidose heparin treatment in patients undergoing surgery for supratentorial brain tumors. METHODS: One hundred three patients, all 40 years of age or older, were treated with either 5000 U of heparin (55 patients) or placebo (48 patients) starting 2 hours before surgery and continuing until full mobilization or for 7 days. Both groups were well matched for sex, weight, duration of surgery, and tumor diagnosis. Subjective and objective parameters were used to estimate and calculate the perioperative bleeding tendency in all patients. Red blood cell mass loss was calculated by assessing the preoperative and postoperative hematocrit and the patient's weight. Intraoperative blood loss was determined by measuring the quantity of blood in the suction containers and subtracting the amount of irrigation fluids. Postoperative bleeding was measured by determining the amount of fluid in the subgaleal drain, and blood cell replacement was monitored during and after the procedure. Intracranial bleeding was graded according to findings on the postoperative computerized tomography scan obtained 48 to 72 hours after surgery. In addition, the senior surgeon in each case was asked to assess each patient's bleeding tendency during the operation. The results showed that perioperative administration of heparin did not significantly alter bleeding tendency by any measured parameter. The surgeon was blinded to which group individual patients had been allocated. CONCLUSIONS: Perioperative minidose heparin is safe for use in patients undergoing craniotomy for supratentorial tumors. This relatively simple and inexpensive measure is recommended as a routine regimen for the prevention of TEPs in patients undergoing neurosurgery.

Anticoagulants↗
PubMed2001

Spinal dural arteriovenous fistulae--a diagnostic challenge.

BACKGROUND: Spinal dural arteriovenous fistulae comprise the majority of spinal vascular malformations. The most common clinical presentation is that of progressive myeloradiculopathy, probably related to venous hypertension, which may lead to permanent disability and even death. OBJECTIVE: To report our clinical experience with spinal dural arteriovenous fistulae. METHODS: Nine patients with spinal dural AVF were managed at our center during a one year period (1998-1999). The patients, eight men and one woman ranging in age from 46 to 75 years, presented with initially fluctuating and eventually permanent and progressive paraparesis, sensory disturbances and sphincter dysfunction. The neurological signs generally began symmetrically and progressed from the distal to proximal limb regions. The duration of symptoms before diagnosis ranged from 6 to 36 months during which the patients underwent an extensive but fruitless work-up and even unnecessary operations due to misdiagnosis. All patients finally underwent magnetic resonance imaging and spinal angiography, which demonstrated the pathological vascular fistula. Interruption of the AVF was achieved by embolization or by surgical resection. RESULTS: Following treatment, six patients experienced improvement of gait and sphincter control, and the severe neurological deficits stabilized in the other three patients with long duration of illness. There was no further deterioration in any of the treated patients. CONCLUSIONS: The history, neurological findings and radiological changes on MRI scan should alert clinicians to the possibility of spinal dural AVF, leading to diagnostic spinal angiography. Early diagnosis and treatment may significantly improve outcome and prevent permanent disability and even mortality.

Aged↗
PubMed2000

Spontaneous pneumocephalus in the posterior fossa in a patient with a ventriculoperitoneal shunt: case report.

OBJECTIVE AND IMPORTANCE: A unique case of spontaneous pneumocephalus is described. It appeared a few years after the uneventful introduction of a cerebrospinal fluid shunt and was probably attributable to a defect of the posterior mastoid plate. CLINICAL PRESENTATION: A 65-year-old man presented with a subacute onset of vertigo, vomiting, and atactic gait instability. The patient had undergone a ventriculoperitoneal shunt implantation 2 years previously for communicating hydrocephalus. A computed tomographic scan revealed a posterior fossa pneumatocele without hydrocephalus. INTERVENTION: A simple mastoidectomy was performed. Detection of the area of the bone defect was followed by mastoid obliteration with abdominal fat. CONCLUSION: Clinicians should be aware that pneumocephalus can occur spontaneously, with or without obvious shunt problems. Treatment should be directed toward the area through which air penetrated the posterior fossa.

Aged↗
PubMed2000

Treatment of spontaneous carotid-cavernous fistula in Ehlers-Danlos syndrome by transvenous occlusion with Guglielmi detachable coils. Case report and review of the literature.

The authors report on a young woman with Ehlers-Danlos syndrome (EDS) Type IV in whom a spontaneous direct carotid-cavernous fistula (CCF) was treated by transvenous occlusion with regular and fiber-coated Guglielmi detachable coils. To the authors' knowledge, this is the first time this approach has been used in a patient with EDS. The different treatment options are discussed, and the literature on endovascular treatment of direct CCFs in EDS is reviewed.

Adult↗
PubMed1999

Principles and concepts of brain death and organ donation: the Jewish perspective.

The harvesting of organs for transplantation is dependent on a stringent definition of brain death. Different societies have had to struggle with their cultural heritage, adapting it to conform to the advances in medical science and the need of the sick. In this article, the development of the concept of brain death as it applies to organ transplantation in Judaism is outlined. The ability of traditional Jewish values to address themselves to the challenges of modern medicine can serve as a basis for cultural cross-fertilization and comparison in modern societies.

Attitude↗
PubMed1999

Endoscopic transnasal transsphenoidal microsurgery versus the sublabial approach for the treatment of pituitary tumors: endonasal complications.

OBJECTIVE: To evaluate the nasal complications after transnasal transsphenoidal operations for pituitary tumors, comparing two surgical techniques: traditional sublabial transseptal and endoscopic transseptal techniques. STUDY DESIGN: We retrospectively evaluated by self-reported questionnaire and endoscopic examination the nasal condition of 40 consecutive patients with pituitary tumors: 20 patients had endoscopic surgery and 20 had surgery with the traditional sublabial technique. RESULTS: Compared with the traditional technique, the endoscopic approach was associated with a shorter operative time (about 40 min), shorter hospitalization time (about half), absence of recurrent epistaxis snoring and denture problems, and lower incidence of septal perforation, synechia, and crust formation. Furthermore, loss of nasal tip projection was found only in the group that had surgery with the sublabial technique. CONCLUSIONS: Endoscopically guided transseptal transsphenoidal surgery is simple to perform and time-saving, and it results in fewer nasal and denture complications than the sublabial technique. At the same time, it allows the surgeon all the benefits of the binocular microscopic surgical field that are associated with the traditional approach.

Adenoma↗
PubMed1998

Principles and concepts of brain death and organ donation: the Jewish perspective.

The harvesting of organs for transplantation is dependent on a stringent definition of brain death. Different societies have had to struggle with their cultural heritage, adapting their traditional attitudes to conform to the advances in medical science and the needs of the sick. In this article, the development of the concept of brain death as it applies to organ transplantation in Judaism is outlined. The ability of traditional Jewish values to address themselves to the challenges of modern medicine can serve as a basis for cultural cross-fertilization and comparison in modern societies.

Abortion, Induced↗
PubMed1997

Adrenosensitivity of injured afferent neurons does not require the presence of postganglionic sympathetic terminals.

Nerve injury sometimes triggers neuropathic pain states that are exacerbated by sympathetic efferent activity. A classic example is causalgia. The mechanism of coupling between sympathetic efferent activity and the afferent discharge responsible for pain sensation is a subject of controversy. Some authors hold to the 'direct coupling hypothesis' which proposes that noradrenaline (NA), released from sympathetic varicosities, acts directly on alpha-adrenoreceptors located in the membrane of injured primary afferents. Others believe that coupling is indirect; that the effects of NA are mediated by additional, non-adrenergic, chemical substances and their receptors (the 'indirect coupling hypothesis'). For example, it has been proposed that in inflamed skin NA acts back on the sympathetic endings which, secondarily, release a prostanoid mediator which sensitizes afferent endings. We report that the responsiveness of injured afferent axons to systemically applied NA persists, and in fact increases in prevalence, in rats that underwent prior chemical or surgical sympathectomy. The observation of adrenosensitivity in injured afferents in the absence of sympathetic postganglionic endings is consistent with the direct coupling hypothesis, which associates adrenosensitivity with the injured afferent axon. It is not consistent with the indirect coupling hypothesis which requires the presence of sympathetic endings as a source for NA-evoked prostanoid release.

Adrenergic alpha-Agonists↗
PubMed1997

Endoscopic transseptal transsphenoidal surgery for pituitary tumors.

OBJECTIVE: Transseptal transsphenoidal surgery of pituitary tumors is a well-established surgical technique. The sublabial approach and the open rhinoplasty approach are most commonly used. In both cases, the surgical avenue is along the entire length of the nasal septum, removing both nasal cartilage and the vomer. Septal perforations and upper dental anesthesia are frequent complications of the standard approaches. We describe our initial experience in using the nasal endoscope for the first stage of the operation. METHODS: A nasal endoscope was used to open the anterior wall of the sphenoid sinus. Our initial incision was in the posterior third of the septum, removing only the vomer. After the sphenoid sinus was opened, we inserted a speculum and proceeded with the operation with an operating microscope. After the speculum was in place, it was easier to proceed with the microscope, which allows binocular vision and bimanual operation. RESULTS: The procedure was used for our most recent 14 consecutive patients with pituitary adenomas. No complications related to the approach were encountered for any of the patients in follow-up monitoring. CONCLUSION: The endoscopic transseptal approach to the sphenoid sinus for pituitary surgery was found to be easy, time-saving, and without septal or sublabial complications.

Adenoma↗
PubMed1997

An electron-microscopic analysis of biopsy samples of the trigeminal root taken during microvascular decompressive surgery.

During surgical exposure of the trigeminal root for the treatment of trigeminal neuralgia, biopsy specimens of the nerve root were taken in 12 consecutive patients. The biopsies were taken from areas as close as possible to the site of vascular compression, when present. The tissue was prepared for electron-microscopic evaluation. Except for 1 case, massive disruption of tissue ultrastructure was observed. The major findings included zones of de- and dysmyelination, juxtaposition of denuded axons, apparent axon loss and degeneration, and collagen deposition. Adjacent areas of normal root structure were present in most specimens. The ultrastructural changes observed in the biopsy samples demonstrate important pathology within the trigeminal root. Dysmyelination and the proximity of denuded axons in close apposition to each other support neurophysiological theories of pain production including ectopic electrogenesis, ephaptic contacts, and crossed after-discharge. The findings in this study demonstrate a pathophysiological basis for the syndrome of trigeminal neuralgia.

Adult↗
PubMed1996

[Microvascular decompression in trigeminal neuralgia].

30 cases of trigeminal neuralgia (TN) were operated between 1988-1995. 26 underwent microvascular decompression (MVD) and 4 others had partial rhizotomies. 87% of the patients became and remained pain-free, while 13% had only partial relief of pain. Permanent side-effects included unsteadiness of gait in 1 and hearing loss on the operated side, in another. There was no serious morbidity or mortality. In the same period, 119 patients underwent retrogasserian glycerol injections for TN. MVD is recommended as an effective procedure in those under 65 years of age, in whom there is no medical contraindication to craniotomy.

Adult↗