Conservative open anterior acromioplasty

The records of 29 consecutive patients treated by a pure, open, anterior acromioplasty were reviewed retrospectively. Excluded from consideration were patients with the following pathologic diagnoses or histories: (1) previously attempted acromioplasty on the same shoulder; (2) intraoperatively confirmed rotator cuff tear; (3) any surgically treatable biceps tendon or acromioclavicular abnormality; (4) lost to follow-up study. Three different techniques were employed to perform the acromioplasties. The first technique required partial deltoid origin detachment with an osteotome. The second technique spared the deltoid origin, while again using an osteotome to perform the acromioplasty. The third technique also spared the deltoid origin but used a high-speed burr to perform the acromioplasty. Evaluated in terms of patient satisfaction, residual pain, length of convalescence, suboptimal results, and complications, the first technique proved to be the least effective. The second technique produced early, excellent results. The third technique, in which a burr was employed through an intact deltoid origin, was most effective; technically, the method was also relatively simple and reliable.     

Fine structure of surviving heart muscle cells in ventricular aneurysms

Surgically-obtained tissue specimens from 41 patients with ventricular aneurysm were studied electron microscopically. The tissue from the resected aneurysms showed substantially varied morphological differences. In some, there were extensive regions of scar containing increased fibrotic material and few cells, in others there were also larger contiguous regions of myocardium with an essentially normal appearance. In the preserved myocardial regions, the cardiac cells showed moderate hypertrophy. There was an increase in contractile substance in parallel with an increase in mitochondria and enlargement of the nucleus with frequent waves and invaginations in the cell membrane. The cells at the marginal regions between fibrous tissue and preserved myocardium were frequently isolated from adjacent cells. In particular, when the isolated cells were completely surrounded by fibrous tissue, clear degeneration was apparent. These cells showed mainly a fibrillolysis with dissolution of the cross-bands and loss of the entire contractile apparatus. In compensation, occasionally there was proliferation of other cell structures, especially the free sarcoplasmatic reticulum. The hypertrophy of the still intact myocardial cells is considered compensatory for the infarct-incurred loss of tissue. The degenerative appearance is mainly attributable to fibrous tissue invasion. The diminished oxygen supply, compromised or abolished impulse conduction, loss of function and passive stretch during systole may be regarded as causes of the degeneration.     

Gangliosides of human melanoma: altered expression in vivo and in vitro

The ganglioside composition of human melanoma was analyzed in five sets of tumor specimens obtained directly from surgery, from the autologous tissue culture cell lines, and from the autologous cell lines grown in athymic nude mice. Total gangliosides of these 15 melanoma specimens were isolated and purified, and the amount of each component ganglioside was analyzed by thin-layer chromatography and a thin-layer chromatography scanner. The ganglioside composition of the five surgical melanoma specimens clearly exhibited different patterns from each other. Moreover, none of the autologous cultured melanomas possessed the same ganglioside composition as their original biopsied tumors. However, when these melanoma cell lines were transplanted into nude mice, the ganglioside composition was converted back to the same ganglioside pattern as in the original surgical specimens. The results support the view that changes in the ganglioside composition of melanoma during in vitro growth are caused by the culture environment rather than by selection of melanoma cells with a particular genotype. Reestablishment of the original ganglioside patterns after passage in nude mice provides clear evidence that in vivo expression of gangliosides is a conserved and stable function specified by the human melanoma cells.     

Specific selection of osteosynthetic material in the treatment of thoracic or lumbar spinal injuries by the posterior approach

Summary The authors report 165 cases of thoraco-lumbar lesions with neurological dysfunction. All the patient were operated. They analyze the neurological and mechanical results and indicate the use of different osteosynthesis apparatus according to the type and level of lesions.Harrington's rods seem to give more precise repositioning while Roy Camille's plates give more stability. When the posterior wall of the spinal canal is intact, Kempf's compression rods can be used.Thoraxic spine injuries seem to be an indication for Harrington's rods, while lumbar injuries seem to call for Camille's plates.     

Intubating conditions after vecuronium and atracurium given in divided doses (the priming technique)

Intubating conditions have been assessed at 60 s following administration of vecuronium 0.1 mg kg-1 or atracurium 0.5 mg kg-1 given either as a single dose after induction of anaesthesia with thiopentone or in divided doses; vecuronium 0.015 mg kg-1 followed 4 or 6 min later by 0.085 mg kg-1, or atracurium 0.075 mg kg-1 followed 4 or 6 min later by 0.425 mg kg-1. In the divided dose groups the smaller initial (priming) dose was given prior to induction of anaesthesia. Onset and duration of clinical relaxation were assessed using a peripheral nerve stimulator. The intubating conditions at 60 s improved significantly, with the use of relaxants in divided doses being acceptable in 80 and 70% of patients, respectively, with vecuronium and atracurium, but the conditions are not as good as those commonly found using suxamethonium. Priming at 6 min has no advantage over priming at 4 min. The onset of complete block was accelerated with priming, but the difference was not significant. The duration of clinical relaxation of vecuronium was significantly prolonged by giving it in divided doses. Unpleasant awareness of muscle weakness was observed in 15 patients, requiring early induction of anaesthesia in five of them.