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Biomedical subjects

D Segal

Publications and source records attributed to D Segal.

At least 163 records · Page 9Linked to original sources
PubMed1976

Endorphins: profound behavioral effects in rats suggest new etiological factors in mental illness.

The endogenous morphinomimetic brain peptides Met5-enkephalin and alpha-, beta-, and gamma-endorphins have been evaluated in rats after intracerebrospinal fluid injection. beta-Endorphin produces marked, prolonged muscular rigidity and immobility similar to a catatonic state, counteracted by the opiate antagonist naloxone; this effect occurs at molar doses 1/100 to 1/400 that at which the other peptides or morphine block the response to painful stimuli. All peptides evoked dose-related, naloxone-reversible, wet-dog shakes in rats that had not been exposed to drugs. beta-Endorphin produced hypothermia, whereas gamma-endorphin produced hyperthermia. Such potent and divergent responses to naturally occurring subtances suggest that alterations in their homeostatic regulation could have etiological significance in mental illness.

Animals↗
PubMedDate not supplied

Behavioral analysis of Drosophila mutants displaying abnormal male courtship.

We describe six recessive autosomal male sterile mutations in Drosophila, generated by mobilization of single P-elements, exhibiting abnormal male courtship behavior. Detailed analysis of courtship behavior elicited by virgin wild type females indicated that five of the six mutants are affected in the early steps of courtship. The sixth mutant is blocked at the step of attempted copulation which occurs later in the courtship sequence. All of the mutants have normal olfactory responses and normal locomotor activity. No defect in the visual modality has been observed for the five mutants affected in the initiation of courtship. The mutant blocked at attempted copulation lacks the 'on' and 'off' transients, but this appears to be due to genetic background rather than the mutation itself. Abnormal spermatogenesis was observed in five of the mutants. Spermatogenic defects vary and include lesions in the proliferation of the germline, in meiosis, and in the differentiation and maturation of the spermatids into motile sperm.

Animals↗
PubMedDate not supplied

Targeting endothelium for gene therapy via receptors up-regulated during angiogenesis and inflammation.

Endothelial cells are an attractive target for gene therapy because they are intimately involved in disease processes associated with inflammation and angiogenesis and because endothelial cells are readily accessible to gene therapy vectors via the circulation. Furthermore, specific receptors are up-regulated during angiogenesis or during inflammation. Therefore it should be possible to target the specific populations of endothelial cells involved in each of these disease processes. We have utilized two bispecific antibodies to target entry of an adenovirus vector into endothelial cells expressing a receptor up-regulated during angiogenesis (alpha v integrins) and a receptor up-regulated during inflammation (E-selectin). Both bispecific antibodies contain the anti-FLAG M2 mAb, which binds to a FLAG epitope genetically incorporated into the penton base protein of the vector, AdFLAG. The anti-alpha v-integrin x anti-FLAG bsAb was able to direct binding and entry of AdFLAG into endothelial cells via alpha v integrins. Likewise, the anti-E-selectin x anti-FLAG bsAb was able to direct binding and entry of AdFLAG into tumor-necrosis-factor(TNF)-activated endothelial cells via E-selectin. Endothelial cells not activated with TNF were not efficiently transduced by the AdFLAG/E-selectin bsAb complex. These results demonstrate that bispecific antibodies can be successfully used to target adenovirus to endothelially expressed receptors that are up-regulated during angiogenesis or inflammation.

Adenoviridae↗
PubMedDate not supplied

Ender nailing of acute humeral shaft fractures in multiple injuries.

From January 1987 to April 1993, 25 multiply injured patients were treated with closed intramedullary Ender nail fixation of the humeral shaft. Criteria for the procedure were humeral diaphyseal fractures with associated multiple injuries. Seventeen distal and mid-shaft fractures were treated via a modified anterograde approach in which the rotator cuff is not violated. Eight proximal third fractures were treated via the standard retrograde approach. Postoperative follow-up averaged 36 months. Full range of motion was attained 17 of the 25 patients. Of the eight remaining patients, three with a slightly limited range of motion achieved full range of motion following nail removal; three had preoperative radial nerve palsy which resolved within 1 year, and two patients required follow-on plating. In 92 per cent (23 of 25) there were no incidences of infection or non-union. Flexible nails avoid complications of reaming. The modified anterograde approach allows excellent shoulder motion since it does not violate the rotator cuff. Ender nails provide excellent fixation and clinical outcome in the multiply injured patient and are cost effective compared with interlocking nails.

Adolescent↗
PubMedDate not supplied

Gerdy's tubercle osteotomy for the treatment of coronal fractures of the lateral femoral condyle.

Coronal fractures of the femoral condyle (Hoffa fractures) are intraarticular fractures that are commonly treated surgically by open reduction and internal fixation. Surgical fixation is demanding because anatomic reduction is mandatory and adequate exposure is often difficult. Herein we describe a new technique that permits excellent visualization and fixation of lateral Hoffa fractures based on osteotomy of Gerdy's tubercle and reflection of the attached iliotibial band.

Cartilage, Articular↗