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Biomedical subjects

S Nissim

Publications and source records attributed to S Nissim.

7 recordsLinked to original sources
PubMed1999

Transplantation of neural progenitor and stem cells: developmental insights may suggest new therapies for spinal cord and other CNS dysfunction.

Multipotent neural progenitors and stem cells may integrate appropriately into the developing and degenerating central nervous system. They may also be effective in the replacement of genes, cells, and nondiffusible factors in either a widespread or a more circumscribed manner, depending on the therapeutic demands of the clinical situation. In addition, they may be uniquely responsive to some types of neurodegenerative conditions. We believe that these various appealing capabilities are the normal expression of basic biologic properties and attributes of a stem cell. The therapeutic utility of some of those properties is illustrated in this review of ongoing work in our laboratory, particularly with regard to spinal dysfunction. In these examples, we believe we have tapped into a mechanism that underlies a remarkable degree of natural plasticity programmed into the nervous system at the cellular level, and we have now exploited those properties for therapeutic ends.

Animals↗
PubMed1984

Thromboxane, prostacyclin, beta-thromboglobin, and diabetes mellitus.

Plasma levels of beta-thromboglobin (beta-TH) and of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1-alpha, the stable metabolites of thromboxane A2 and prostacyclin, were determined by radioimmunoassay methods in eight patients with noninsulin-dependent diabetes before and after dietary treatment and after administration of the sulfonylurea drug glibenclamide. Blood examinations were performed when hyperglycemia was detected for the first time, four weeks after a dietary regimen was started, and four and eight weeks after glibenclamide treatment was begun. Drug treatment was instituted because, despite a suitable diet, patients' postprandial blood sugar was higher than 8 mmol/L (145 mg/dl). At the initial examination, elevated TXB2 and beta-TH levels indicating platelet hyperactivity and hyperglycemia were found. TXB2 and beta-TH levels decreased significantly after glibenclamide treatment was started, as did the blood glucose level. There was no change in 6-keto-PGF1-alpha. We interpret these results to indicate that diabetes is associated with hyperactivity of platelet aggregation and that control of blood glucose is important because a lower blood glucose level attenuates platelet hyperactivity. Whether the decrease in platelet hyperactivity is a direct result of the lowered blood sugar or reflects the influence of the drug treatment requires clarification.

6-Ketoprostaglandin F1 alpha↗
PubMed1975

Visual evoked responses in the assessment of field defects in glaucoma.

A technique for producing steady state visual evoked responses (VERs) to pattern reversal stimulation of retinal areas corresponding to discrete field quadrants is described. Patients examined included 10 normal individuals, 11 patients with ocular hypertension, and 21 with glaucomatous field defects (unilateral except in two cases with bilateral defects). The VERs relating to normal homonymous field quadrants were in phase in all three groups, excluding patients with cataracts. The VERs corresponding to quadrants with small field defects showed a phase shift compared with responses from normal homonymous quadrants in all cases, but were not detectable if the defect filled more than three quarters of the quadrant tested in most cases. The method offers a means for the objective assessment of visual fields in patients with unilateral optic nerve lesions, provided that central visual acuity is 20/80 or better

Evoked Potentials↗
PubMed1975

Complete avulsion of the optic nerve. A clinical, angiographic, and electrodiagnostic study.

A case of traumatic complete avulsion of the optic nerve is reported together with fluorescein angiography and electrodiagnostic findings. Despite the disappearance of the central vessels, circulation remained in the branch retinal vessels and angiography demonstrated communication between peripapillary choroidal vessels and the superior temporal artery. The visually-evoked cortical response was abolished. Electroretinography showed a normal a-wave but reduced amplitude b-wave, not supporting the theory of the existence of centrifugal retino-suppressive fibres in the optic nerve of man.

Adult↗