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Biomedical subjects

O Friedman

Publications and source records attributed to O Friedman.

11 recordsLinked to original sources
PubMed2006

Blood-brain barrier disruption results in delayed functional and structural alterations in the rat neocortex.

Disruption of the blood-brain barrier (BBB) is a characteristic finding in common neurological disorders. Human data suggest BBB disruption may underlie cerebral dysfunction. Animal experiments show the development of epileptiform activity following BBB breakdown. In the present study we investigated the neurophysiological, structural and functional consequences of BBB disruption. Adult rats underwent focal BBB disruption in the rat sensory-motor cortex using the bile salt sodium deoxycholate (DOC). Magnetic resonance imaging in-vivo showed an early BBB disruption with delayed reduction in cortical volume. This was associated with a reduced number of neurons and an increased number of astrocytes. In-vitro experiments showed that the threshold for spreading depression and the propagation velocity of the evoked epileptic potentials were increased 1 month after treatment. Furthermore, animals' motor functions deteriorated during the first few weeks following BBB disruption. Treatment with serum albumin resulted in a similar cell loss confirming that the effect of DOC was due to opening of the BBB. Our findings suggest that delayed neurodegeneration and functional impairment occur following the development of the epileptic focus in the BBB-permeable cerebral cortex.

Animals↗
PubMed2005

Acute and fatal hyponatraemia after resection of a craniopharyngioma: a preventable tragedy.

Central diabetes insipidus developed for the first time in a 14-year-old female during the resection of a craniopharyngioma. The water diuresis persisted until a vasopressin analogue (dDAVP) was given. Professor McCance was asked to explain why hypernatraemia developed, to anticipate dangers that might develop in the salt and water area with therapy, and to provide insights into why this patient died, due to the subsequent development of hyponatraemia that caused a lethal rise in intracranial pressure. The team specifically wanted Professor McCance's opinions as to why a PNa of 124 mmol/l was uniquely dangerous for this patient, and this was a particularly challenging conundrum. Nevertheless, with the aid of a mini-experiment, a careful chart review, and creative thinking, he was able to offer a novel solution, and to suggest ways to prevent its occurrence in other patients.

Adolescent↗
PubMed2000

Xanthoma of the temporal bone: a unique case of this rare condition.

Xanthoma of the temporal bone is extremely rare; we describe only the fourteenth reported case. Our case is further remarkable because it is the first report of such an occurrence in a patient with familial type III hyperlipoproteinemia. Moreover, while otalgia, infection, hearing loss, and tinnitus were the most common initial symptoms in the previous 13 cases, our patient reported only diplopia, vertigo, and unstable gait. The patient underwent a simple mastoidectomy and debulking, and his diplopia, vertigo, and unstable gait resolved.

Adult↗
PubMed2000

[Folic acid use by pregnant women in Israel for preventing neural tube defects].

Spina bifida and anencephaly are the most common, serious malformations in neural tube defects (NTD). Randomized trials in the last 2 decades have demonstrated that folic acid, 0.4 mg/d, reduces the incidence of NTD by more than 50%. We investigated the use of folic acid and multivitamins containing folic acid in childbearing women. Of 221 women interviewed, 67 (30%) regularly took pills containing 0.4 mg folic acid. Women with higher educational levels were more likely to take multivitamins with folic acid than were the less educated (p = 0.05). Of the women who took folic acid, only 5 (7.5%) used separate folic acid tablets, before and during their pregnancy. The rest used multivitamins containing folic acid. The 5 women who took folic acid separately were college-educated and nonreligious, and they took multivitamins in addition (p > 0.05). Of the women interviewed, 58 (26.2%) were Bedouin of the Negev. 24 (41.4%) of them took pills containing folic acid on a regular basis. This percentage is higher than that in the Jewish women in the study who took folic acid for prevention of NTD (17%; p = 0.038). Most of the women took folic acid after the first trimester. Only a minority took daily periconceptional folic acid. Multivitamins containing 0.4 mg of folic acid were more popular than folic acid tablets alone. This study emphasizes the need for continuing efforts to increase consumption of folic acid and awareness of its benefits among women of childbearing age.

Adult↗
PubMed1999

Postoperative bilevel positive airway pressure ventilation after tonsillectomy and adenoidectomy in children--a preliminary report.

Obstructive sleep apnea (OSA) in children, characterized by hypoventilation secondary to upper airway obstruction, often results from tonsil and adenoid hypertrophy. Adenotonsillectomy is the standard therapy in this patient population. The immediate postoperative period is complicated occasionally by respiratory difficulties that may require intubation and mechanical ventilation. Recently, physicians have provided temporary airway support using continuous and bilevel positive airway pressure (BiPAP) devices. Reported complications of positive airway pressure devices include local abrasions to the nose and mouth; dryness of the nose, eyes, and mouth; sneezing; nasal drip, bleeds, and congestion; sinusitis; increased intraocular pressure; non-compliance; and pneumocephalus. Subcutaneous emphysema following facial trauma, dental extractions, adenotonsillectomy, and sinus surgery has been reported. There is also a hypothetically increased risk of subcutaneous emphysema following the use of positive airway pressure ventilation in the tonsillectomy patient. Between January 1997 and July 1998, 1321 patients underwent tonsillectomy and/or adenoidectomy at our institution. In reviewing the records of all pediatric intensive care unit admissions during that time period, we identified nine patients, of the 1321, who required BiPAP postoperatively. Of these, four children were obese, four had preexisting neurological disorders, and one underwent endoscopic sinus surgery and adenoidectomy. Three children were asthmatic, and three were less than 3 years of age. Two obese children were discharged with home BiPAP, one of whom had been on BiPAP prior to surgery. All patients tolerated BiPAP without complications. This preliminary report suggests that BiPAP is a safe and effective method of respiratory assistance in the adenotonsillectomy patient with preexisting conditions who is predisposed to postoperative airway obstruction. Furthermore, with BiPAP, the risks of intubation and ventilator dependence are avoided.

Adenoidectomy↗
PubMed1999

Transcription control and neuronal differentiation by agents that activate the LXR nuclear receptor family.

LXR and PPAR receptors belong to the nuclear receptor superfamily of transcriptional activating factors. Using ligand-dependent transcription assays, we found that 5-tetradecyloxy-2-furancarboxylic acid (TOFA) transactivates chimeric receptors composed of the glucocorticoid receptor DNA binding domain and the ligand binding regions of PPARalpha, PPARbeta (NUC-1) and LXRbeta (NER) receptors. In the same assays, ligands for PPARs (oleic acid, WY-14643 and L-631,033) and LXRs (hydroxycholesterols) maintain their respective receptor selectivity. TOFA and hydroxycholesterols also stimulate transcription from a minimal fibrinogen promoter that is under the control of AP-1 or NF-kappaB transcription factor binding sites. In addition to their effects on transcription, these LXRbeta activators induce neuronal differentiation in rat pheochromocytoma cells. TOFA and the natural LXR agonist, 22 (R)-hydroxycholesterol, stimulate neurite outgrowth in 55 and 28% of cells, respectively. No neurite outgrowth was induced by the related 22(S)-hydroxycholesterol, which does not activate the LXR family. These results suggest that the hydroxycholesterol signaling pathway has a complex effect on transcription that mediates the activity of TOFA and hydroxycholesterol on neuronal differentiation in pheochromocytoma cells.

Animals↗