The action of nerveside, a peptide extracted from brain, on myenteric ganglia in Auerbach's plexus

1. In the rabbit jejunum nerveside causes alternating contractions of the longitudinal and circular muscles, which are similar to the peristaltic reflex produced by distension of the gut. These effects are abolished by dibucaine (Nupercaine) and tetrodotoxin. The site of action is located in Auerbach's plexus.

2. Circular muscle contractions due to nerveside are blocked by hexamethonium, nicotine, morphine, atropine and hyoscine. There is no circular response to nerveside after removal of Auerbach's plexus. It is suggested that nerveside acts by stimulating presynaptic nerve terminals which are cholinergic and that the circular muscle is innervated by cholinergic nerve fibres.

3. Longitudinal muscle contractions due to nerveside are not affected by hexamethonium but can be blocked by paralysis of myenteric ganglia with nicotine. They are not abolished by morphine or by cholinolytic drugs. It is suggested that nerveside acts by stimulating either receptors insensitive to acetylcholine in ganglion cells or non-cholinergic presynaptic nerve terminals. It is further suggested that the longitudinal muscle of the rabbit gut is supplied by non-cholinergic as well as cholinergic nerve fibres.

     

Salvage of contaminated fractures of the distal humerus with thin wire external fixation

Fractures and osteotomies of the distal humerus that are contaminated or infected represent a difficult management problem. Stable anatomic fixation with plates and screws, the acknowledged key to a good result in the treatment of bicondylar fractures, may be unwise. A thin wire circular (Ilizarov) external fixator was used as salvage treatment in such complex situations in five patients. The fixator allowed functional mobilization of the elbow while allowing achievement of the primary goal of eradicating the infection or colonization. Two patients required a second operation for fixation of a fibrous union of the lateral condyle. One patient with a vascularized fibular graft later required triple plate fixation for malalignment at the distal host and graft junction. Four of five patients ultimately achieved complete union. The fracture remained ununited in one patient who has declined additional intervention. All five patients achieved at least 85 degrees ulnohumeral motion, two after a secondary elbow capsulectomy performed after healing was achieved. This experience suggested that the Ilizarov construct, although not a panacea, represents a reliable method of skeletal stabilization that allows functional mobilization while elimination of infection or colonization is ensured. If necessary, stiffness and incomplete healing can be addressed with an increased margin of safety at subsequent operations.     

Vascularized free flaps for reconstruction after resection of congenital arteriovenous malformations of the hand

Between 1981 and 1996, the authors performed reconstructions with vascularized free flaps in four patients with congenital arteriovenous malformations of the hand. This series included one man and three women, whose ages at the time of surgery ranged from 20 to 57 years, with an average of 41 years. All were categorized as fast-flow type B malformations. The locations of the arteriovenous malformations were the thumb only, thumb to palm, index to palm, and thumb and index to palm. In all cases, free vascularized flaps (two dorsalis pedis, one wrap-around, and one peroneal) were utilized to replace the resected abnormal skin lesions. Follow-up ranged from 1 year to 18 years and 9 months, with an average of 7 years. All flaps survived with no complications, and all patients were relieved of their preoperative symptoms. One patient unfortunately committed suicide for unknown reasons. The authors recommend that complete resection be carried out whenever possible. When skin is involved, repair should be carried out with a free flap. Based on the good results achieved in the case followed-up for over 18 years, vascularized free flaps proved very useful for the treatment of arteriovenous malformations.     

Multigenic control of skin tumor susceptibility in SENCARA/Pt mice

Skin tumors induced in mice by initiation-promotion (2 microg DMBA-2 microg TPA) protocols were found to be under multigenic control. Eighty- one N2 mice from the cross (BALB/cAnPt x SENCARA/Pt)F1 x SENCARA/Pt that were either solidly resistant (no papillomas) or highly susceptible (> or = 7 papillomas/mouse) were subjected to a 'genome scan' using 89 microsatellite markers to check for associations with susceptible and resistant phenotypes. A locus on Chr 5 (Skts4) was found to control the susceptibility of SENCARA/Pt mice and the resistance of BALB/cAnPt mice to papilloma formation. In addition, higher than expected linkage scores were seen for the markers D9Mit271, D11Mit268 and D12Mit56. Further work is required to establish whether genes determining papilloma formation are located in these regions of the genome. In general, no evidence was seen for loss of heterozygosity in microsatellite markers on Chrs 5, 9 and 11 in 17 microdissected papillomas from (BALB/c x SENCARA)F1 hybrid mice.      

羧乙基锗倍半氧化物对正常和异丙基肾上腺素损伤培养乳鼠心肌细胞的影响

羧乙基锗倍半氧化物(Ge—132)能促进培养乳鼠心肌细胞DNA和RNA的合成,提高超氧化物歧化酶(SOD)的活性,维持细胞膜结构的稳定。异丙基肾上腺素可使心肌细胞乳酸脱氢酶(LDH)释放增加,细胞搏动停止,超微结构显示肌膜和线粒体严重受损。Ge—132可显著减少异两基肾上腺素引起心肌细胞释放LDH,维持细胞的搏动功能和超微结构的完整。     

固相法合成心肌兴奋肽及其类似物

用Boc-和Tos-基团分别保护氨基和侧链胍基,以1%交联度聚苯乙烯二苯甲氨基树脂为载体,用DCC固相法合成肽,HF断裂肽树脂键和去除侧链保护基团,粗产物经高效液相层析纯化,合成了心肌兴奋肽Phe-Met-Arg-Phe-NH_2及其类似物Phe-Pro-Arg-Phe-NH_2,并观察了此二种肽对大鼠血压和心率的影响。     

Feasibility study for the quantification of total protein content by multiple prompt gamma-ray analysis

Protein is an important nutrient in foods. The classical nitrogen analysis method is the Kjeldahl technique, which is time-consuming and inconvenient. As a convenient method to quantify protein content in biological samples, the feasibility of application of multiple prompt gamma-ray analysis (MPGA) to the quantification was studied. Results for protein content are reported for several reference materials and prove the method to be reliable.