Surgical management of paralytic scoliosis in myelomeningocele.

A retrospective analysis of 54 patients with paralytic scoliosis due to myelomeningocele, who underwent surgical treatment, was performed. The aim of this study was to compare different surgical techniques and to identify clinical parameters influencing primary and midterm results. Three surgical techniques were used: 1) group I, posterior fusion/instrumentation; 2) group II, anterior fusion/no instrumentation combined with posterior fusion/instrumentation; and 3) group III, anterior and posterior fusion/instrumentation. Average age at surgery was 13.1 years. A preoperative scoliosis angle of 90 degrees [interquartile range (25th-75th percentile) (IQR), 76-106 degrees] was primarily reduced to 38 degrees (IQR, 30-50 degrees). At final follow-up (mean, 3.3 years), correction deteriorated to 44 degrees (IQR, 38-65 degrees). The group III procedure resulted in a better midterm correction of scoliosis compared with group I (P = 0.02). The extension of anterior fusion correlated with primary and midterm correction of scoliosis (P < 0.03). Patients with a thoracic level of paralysis had a higher relative loss of correction compared with patients with a lumbar level (P < 0.06). This finding can be attributed mostly to group I patients (P = 0.011). Hardware complications occurred in 16 patients (30%). Relative loss of correction among these patients was high (P < 0.01) and relative midterm correction low (P = 0.001). We recommend anterior and posterior fusion, each with instrumentation for the treatment of paralytic scoliosis in myelomeningocele. In patients with a thoracic level of paralysis, the two-stage procedure is mandatory to reduce the risk of hardware complications and subsequent major loss of correction.

Results of kyphectomy with the technique of Warner and Fackler in children with myelodysplasia.

Pathological lumbar kyphosis occurs in approximately 8% to 20% of patients with myelomeningocele. During the past 4 years, nine patients with an average preoperative kyphosis of 152 degrees were surgically corrected. They had a short fusion and a long stabilization with Luque rod instrumentation using a technique described by Warner and Fackler (1993). The average degree of correction was 104 degrees and, on average, 2.5 vertebrae were resected. The average surgical time was 225 minutes, and blood loss averaged 635 ml. We saw two complications: one penetration of the distal part of the rod through the sacrum after 32 months, and a dislocation of the rods out of the first sacral foramen after 33 months. From our experience, this procedure is highly demanding, but effective. It should be limited to patients below the weight of 30 kg.

The promise of object technology: what's in it for healthcare?

This article focuses on the application of a new business computing model--Objects. Although Object Technology is not new, its widespread use in healthcare information management executives struggle with the integration demands of the new enterprise, Object Technology will unleash the true power of desktop computing and lessen the many quandaries faced with the integration and aggregation of strategic enterprise data. As we move forward, the new healthcare business model will attempt to create the "virtual enterprise." This new enterprise, will be lean and nimble and allow the Integrated Delivery System (IDS) to deliver care to a broader population with fewer requirements for expensive and scarce resources. To do this, the IDS must possess the technology to share key data, with partners and providers, that will allow faster and more accurate decision making. This article presents the "natural fit" of Object Technology and its ability to solve the complex computing issues of the new healthcare enterprise.

[Results of laparoscopic cholecystectomy in elderly patients]. / Ergebnisse der laparoskopischen Cholecystektomie beim alten Patienten.

The results of 277 patients aged 70 years and over are compared to 1522 operations performed on younger patients. Older patients had significantly more postoperative complications; the conversion rate was also higher than in the younger patient collective. Compared to open cholecystectomy, however, the results are in favor of laparoscopic cholecystectomy and also aged patients benefit from this approach.

[Laparoscopic cholecystectomy in pregnancy. A description of 2 cases and review of the literature]. / Laparoskopische Cholecystektomie in der Schwangerschaft. Eine Beschreibung zweier Fälle und Literaturübersicht.

Although pregnancy is still widely considered to be a contraindication to laparoscopic cholecystectomy, several successful cases have been published so far. This paper reports on two cases of laparoscopic cholecystectomy performed during the second trimester for recurrent biliary pancreatitis and acute cholecystitis. There were no intra- or postoperative complications, the obstetric course was also uneventful in both cases. Important aspects to be considered are the placement of trocars and the pressure of the pneumoperitoneum, which should not exceed 12 mmHg. The need for intraoperative monitoring and cholangiography is controversial. The results show, that laparoscopic cholecystectomy is not contraindicated during pregnancy, however, as in open cholecystectomy it should be performed only in cases, where conservative management fails.

[Complications after 1,000 laparoscopic cholecystectomies]. / Komplikationen nach 1000 laparoskopischen Cholecystektomien.

Between November 1990 and November 1993 we performed 1000 laparoscopic cholecystectomies. The conversion rate was 1%. Also the rate of relaparotomies was 1%. Postoperative complications occurred in 5%. Intraoperative problems are described and analysed. We had no bile duct injuries in our series. One 87-year-old patient died on the fourth postoperative day due to mesenterial ischaemia.

The alpha-tubulin of the growth cone is predominantly in the tyrosinated form.

Growth cone cytoskeletons were prepared by detergent extraction of growth cones isolated from neonatal rat forebrain by the method of Gordon-Weeks and Lockerbie (Neuroscience, 13 (1984) 119-136). SDS-PAGE analysis of growth cone cytoskeletons revealed the presence of several major bands, identified by their mobility as actin (43 kDa Mr), myosin heavy chain (195 kDa Mr), spectrin (235 and 240 kDa Mr), and tubulin (51-54 kDa Mr). The identity of these proteins was confirmed by immunoblot analysis using specific antibodies to these proteins which further revealed that the predominant form of alpha-tubulin in the growth cone cytoskeleton and in the soluble pool of tubulin is tyrosinated at the C-terminal.

Proteolysis of ankyrin and of band 3 protein in chemically induced cell fusion. Ca2+ is not mandatory for fusion.

Human erythrocytes were fused by incubation with 0.5-2 mM-chlorpromazine hydrochloride at pH 6.8-7.6. Fusogenic preparations of chlorpromazine were cloudy suspensions of microdroplets, and below pH 6.8 chlorpromazine gave clear solutions that were inactive. Unlike control cells, the lateral mobility of the intramembranous particles of the PF-fracture face of chlorpromazine-treated cells was relatively unrestricted, since the particles were partly clustered at 37 degrees C and they exhibited extensive cold-induced clustering. Ca2+ stimulated fusion, but fusion was only very weakly inhibited by EGTA (10 mM) and by N-ethylmaleimide (50 mM); pretreatment of the cells with Tos-Lys-CH2Cl (7-amino-1-chloro-3-L-tosylamidoheptan-2-one) (7.5 mM) markedly inhibited fusion. Changes in the membrane proteins of erythrocytes fused by chlorpromazine, before and after treatment with chymotrypsin to remove band 3 protein, were investigated. The several observations made indicate that the Ca2+-insensitive component of fusion is associated with degradation of ankyrin (band 2.1 protein) to band 2.3-2.6 proteins and to smaller polypeptides by a serine proteinase that is inhibited by Tos-Lys-CH2Cl, and that the component of fusion inhibited by EGTA and N-ethylmaleimide is associated with degradation of band 3 protein to band 4.5 protein by a Ca2+-activated cysteine proteinase. Proteolysis of ankyrin appeared to be sufficient to permit the chlorpromazine-induced fusion of human erythrocytes, but fusion occurred more rapidly when band 3 protein was also degraded in the presence of Ca2+. Since other cells have structures comparable with the spectrin-actin skeleton of the erythrocyte membrane, the observations reported may be relevant to the initiation of naturally occurring fusion reactions in biomembranes. It is also suggested that, should polypeptides with fusogenic properties be produced from integral and skeletal membrane proteins by endogenous proteolysis, their formation would provide a general mechanism for the fusion of lipid bilayers in biomembrane fusion reactions.

Structure of intramembrane particles in proteoliposomes containing yeast mitochondrial ATPase.

Oligomycin-sensitive ATPase was isolated from yeast mitochondria and incorporated into phospholipid vesicles by cholate dialysis. The structure of the membranes was examined by freeze-fracture electron microscopy. Liposomes formed without the ATPase were small with diameters in the range 20 to 40 nm and they had smooth fracture faces. When the ATPase was introduced, larger vesicles formed (up to 500 nm in diameter) which bore intramembrane particles (IMPs) on their fracture faces. The IMP frequency was dependent on the ratio of protein to lipid used in the reconstitution. After unidirectional shadowing at an angle of 45 degrees, IMPs had a mean width of 12.7 nm and a mean shadow length of 5.9 nm. After rotary shadowing, the mean IMP diameter was 12.9 nm. When the amount of protein was higher than 1 mg/10 mg phospholipid in the initial incorporation mixture, the ATPase formed small hexagonal arrays in the liposome membranes. Computer-based image processing of such arrays showed that the IMPs had a centre-to-centre spacing of 13.7 nm. Calculations showed that each IMP may correspond to an oligomer of the ATPase.

Ultrastructure of sheep erythrocyte plasma membranes and cytoskeletons bound to solid supports.

Sheep erythrocyte plasma membrane monolayers were formed on positively charged supports by means of controlled lysis and squirting of cells so that the original protoplasmic or inner surfaces (PS) were exposed. The appearance of the surface was studied by transmission electron microscopy of platinum/carbon replicas following freeze-drying of the membranes. After gentle washing with water or dilute buffer, a network of filaments and particles was found to cover the surface. Whole cells bound to positively charged supports were treated with Triton X-100 and hypertonic KCl, which left the protein components of the cytoskeleton on the support. Stereo electron microscopy of Pt/C replicas of these residues showed complex networks of filaments, similar to those seen on the cytoplasmic surfaces of the intact membranes. In both cases the lengths of the filaments correspond to that of the spectrin dimer. Removal of spectrin, actin and other proteins by alkaline treatment led to loss of this network and revealed 15.4-nm particles on the membranes PS. These particles, which were also visible after negative staining, could be removed by treatment with trypsin and were found to correspond to band 4 protein (the equivalent of human erythrocyte band 3 protein). Membranes freeze-fractured following treatment with alkali showed normal intramembranous particles with frequencies similar to those of native membranes. This indicates that band 4 protein spans the sheep erythrocyte membrane and forms a very high proportion of the intramembranous particles. The protoplasmic portions of these particles may be membrane binding sites for the cytoskeleton in sheep erythrocytes.

A study of rapid mitochondrial structural changes in vitro by spray-freeze-etching.

The spray-freeze-etching technique has been used to study energy-linked mitochondrial structural changes in rat liver mitochondria incubated in vitro. The technique involves spraying the suspension of mitochondria into liquid propane at -190 degrees C, and does not require the use of cryoprotectants or chemical fixatives. The results confirmed that freshly isolated mitochondria have a condensed matrix and that this expands at the expense of the outer compartment to give the orthodox configuration when the mitochondria are incubated in a K+ medium in the presence of substrate and phosphate. Addition of adenosine diphosphate (ADP) caused a rapid shrinkage of the matrix compartment, and the time-course and extent of this shrinkage has been measured quantitatively by coupling a rapid sampling device to the spray-freezing apparatus. These data show that for orthodox mitochondria the onset of phosphorylation is accompanied by a reduction of 30% in the matrix volume in 20's, and there is no evidence that the decrease in matrical volume affects the phosphorylation efficiency. These results suggest that natural ionophores in the mitochondrial inner membrane make it permeable enough to permit a rapid readjustment of matrix volume after the addition of ADP, and that the associated ion movement does not cause uncoupling of oxidative phosphorylation.