Thoracoscopic wedge resection

Summary Thoracoscopic surgery is decidedly expanded by the ability to perform pulmonary wedge resections of the lung by using the Endo-GIA-stapler. In addition to thoracoscopic biopsies, since July 1991 we have carried out wedge resections in 12 patients suffering from spontaneous pneumothorax (nine) or peripheral bronchial carcinoma (three). Postoperatively one air fistula persisted over 9 days. The chest tube was removed within 48 h in all other patients. There was no other major complication. The postoperative hospitalization period lasted 4.6 days (1–9 days). Operating time was 44 min (30–70 min). The benefit for the patient consists in the little-impaired breathing mechanics, the short hospital stay, and the favorable cosmetic result.     

Cell proliferation in human tumours growing in nude mice: renal cell carcinomas,larynx and hypopharynx carcinomas

Summary Cell proliferation of 51 human renal cell carcinomas and 9 larynx and hypopharynx carcinomas has been studied in vitro and using xenotransplants. The proliferative activity ([³H]thymidine labelling index) increases during the first passages in nude mice and then remains almost constant throughout subsequent passages. A comparison of cell kinetic parameters of 8 human renal cell carcinomas, 1 hypopharynx and 2 larynx carcinomas, with data of xenografts and of human tumours in situ published up to now, shows that the cell kinetic parameters of human tumour xenografts presently studied range between those of human tumours in situ and those of autochthonous or transplantable mouse tumours. S-phase durations and potential doubling times are considerably shorter in xenotransplants than in human tumours in situ, whereas the cycle time is about the same. This means that the growth fraction increases considerably after xenotransplantation. This change of human tumour cell proliferation after transplantation into nude mice should be kept in mind if one wishes to draw conclusions from the nude mouse model on conditions in human beings, particularly with respect to therapeutic regimens, which are frequently tested in the nude mouse model.Abbreviations used RCC renal cell carcinoma - HPC larynx or hypopharynx carcinoma - LI labelling index - PLM percentage of labelled mitoses - t _s S-phase duration - t _c cycle time - t _pot potential doubling time This work was supported by the Deutsche Forschungsgemeinschaft (Ma 876/2-1)     

Regional preferences of AMPA receptor modulators determined through agonist binding autoradiography

Autoradiographic techniques were used to test if positive modulators of AMPA-type glutamate receptors have regionally differentiated effects on ligand binding. Cyclothiazide, a drug with ten fold greater effects on `flip' than `flop' splice variants of the receptors, had unequal effects across the subdivisions of hippocampus; i.e., it reduced [³H]AMPA binding in field CA3 with an EC₅₀ of 24 μM and in field CA1 and dentate gyrus with EC₅₀s between 60 and 100 μM. The EC₅₀ for the drug's influence on binding was also significantly lower in the superficial than in the deeper layers of the neocortex, though these differences were not as pronounced as those in the hippocampus. The ampakine CX614, a compound with a modest preference for flop variants, had a slightly lower EC₅₀ for its effects on [³H]AMPA binding in CA1 than in CA3. This result was confirmed with [³H]fluorowillardiine binding. The effects of the ampakine in neocortex tended to be greater in the deeper than superficial layers but this did not reach statistical significance. These results indicate that differential effects of modulators on AMPA receptor subunits are reflected in their relative potency across brain subdivisions. This raises the possibility that subclasses of positive modulators will exhibit a measurable degree of selectivity in their physiological and behavioral influences.     

P物质及其受体在慢性胰腺炎组织的表达和临床意义

目的 了解P物质及其受体NK－1R在正常胰腺和慢性胰腺炎中的表达，探讨它们与慢性胰腺炎时疼痛发生的关系。方法 25个慢性胰腺炎标本取自慢性胰腺炎手术，男性18例，女性7例，正常胰腺组织取自20个器官捐献者，男性11例，女性9例。应用实时定量逆转录整合酶链反应（RT－PCR）技术，检测正常胰腺和慢性胰腺炎组织中P物质和NK－1R的mRNA水平，应用Western blot技术检测NK－1R的蛋白水平，应用免疫组织化学方法进行NK－1R的组织学定位。将P物质及其受体NK－1R mRNA水平与疼痛的程度，发作频率和病程进行分析，寻找其中的相关性。结果 与正常胰腺相比，慢性胰腺炎组织中P物质和NK－1R mRNA和蛋白都过度表达，NK－1RmRNA水平与疼痛的程度，发作频率和病程明显相关。免疫组化检查显示，NK－1R的表达主要位于胰腺腺泡，胰腺导管，神经纤维和炎性细胞。结论 慢性胰腺炎组织中P物质和NK－1R的表达水平都明显上调，扰乱了神经激肽的作用环节，NK－1R的过度表达与疼痛发生有关。     

In vivo measurement of the shear modulus of the human vocal fold: interim results from eight patients

The shear modulus of the vocal fold is an essential parameter required to enhance our understanding of how the vocal fold operates, to develop mathematical models of phonatation, and to provide benchmarks to quantify the effectiveness of surgical procedures. The authors announced the successful deployment of an instrument to measure vocal fold elasticity in vivo last year, and now present the data taken from eight patients in vivo. The shear modulus was measured at the mid-membranous point, in a transverse direction with respect to the axis drawn between the anterior commissure and vocal process. The range of mean shear modulus results is 701–2,225 Pa, with a mean value of 1,371 Pa.     

Perflubron Emulsion in Prolonged Hemorrhagic Shock: Influence on Hepatocellular Energy Metabolism and Oxygen-dependent Gene Expression

Background: Liver dysfunction as a result of impaired oxygen availability frequently occurs following hemorrhage and contributes to delayed mortality. Artificial oxygen carriers may improve oxygen supply to vital organs while avoiding the need for allogeneic transfusion.

Methods: Rats were subjected to hemorrhagic hypotension (mean arterial pressure = 35-40 mmHg for 120 min) and were subsequently resuscitated with (1) stored whole rat blood, (2) pentastarch, or (3) pentastarch combined with perflubron emulsion (PFE; 2.7 or 5.4 g/kg body weight), a second-generation artificial oxygen carrier. Recovery of liver adenosine triphosphate, hepatocellular injury, and expression of glutamine synthetase 1, a gene that is induced by exposure of hepatocytes to low partial pressure of oxygen, were studied at 4 h of resuscitation.

Results: Stored whole blood or pentastarch failed to restore liver adenosine triphosphate concentrations after prolonged shock as compared to sham controls and resulted in increased gene expression of glutamine synthetase 1. Addition of 2.7 g PFE/kg restored liver adenosine triphosphate to control, whereas 5.4 g PFE/kg resulted in adenosine triphosphate concentrations significantly above control. Improved hepatocellular oxygen supply was also confirmed by restoration of the physiologic expression pattern of glutamine synthetase 1. Serum enzyme concentrations were highest after resuscitation with stored blood, whereas addition of PFE failed to further decrease enzyme concentrations as compared to pentastarch alone.     

Characterization of 18F-FDG uptake in human endothelial cells in vitro.

The contribution of (18)F-FDG uptake by endothelial cells to uptake values measured by PET in various tissues is as yet unclear. We therefore sought to characterize (18)F-FDG uptake in an in vitro model of human endothelial cells. METHODS: Commercially obtained human umbilical vein endothelial cells (HUVECs) were seeded in 6-multiwell plates 48-96 h before incubation with 1-2 MBq (18)F-FDG per well. Radioactivity measurements were performed after washing and mechanical dissolvation of the cellular monolayers. Cellular (18)F-FDG uptake was referred to protein concentration. This experimental protocol was subsequently varied to study the effect of different parameters of interest. Furthermore, radio-thin-layer chromatography was used to identify intracellular (18)F-FDG metabolites. (18)F-FDG uptake in HUVECs was compared with that by a human monocyte-macrophage (HMM) preparation and by glioblastoma cells (GLIOs) under identical experimental conditions. RESULTS: (18)F-FDG accumulated in HUVECs in a time-dependent manner and was trapped mainly as (18)F-FDG-6-phosphate and (18)F-FDG-1,6-diphosphate. Unlabeled glucose and cytochalasin B competitively inhibited (18)F-FDG uptake, whereas phlorizin had no significant effect. Glucose deprivation significantly enhanced (18)F-FDG uptake by a factor of 2.7, whereas sodium depletion had no significant influence. HUVECs treated with vascular endothelial growth factor (VEGF) showed a significant 82% increase in (18)F-FDG accumulation after a 2-h exposure to 50 ng/mL VEGF. (18)F-FDG uptake in HUVECs was significantly higher than that in HMMs and in the range of the uptake values measured in GLIOs. CONCLUSION: (18)F-FDG accumulates in HUVECs by mechanisms analogous to those in neoplastic cells or neurons. VEGF significantly stimulates endothelial (18)F-FDG uptake. The observed differences in (18)F-FDG uptake between HUVECs, HMMs, and GLIOs are difficult to extrapolate to in vivo conditions but stimulate further studies on the contribution of endothelial (18)F-FDG uptake to the overall uptake of that tracer in neoplastic or vascular lesions.     

Necrosectomy and postoperative local lavage in patients with necrotizing pancreatitis: Results of a prospective clinical trial

Seventy-four patients with necrotizing pancreatitis were included in a prospective clinical trial of a surgical management protocol comprising necrosectomy and postoperative local lavage of the lesser sac and of the necrosis cavity. Fifty-eight patients showed preoperative organ failures such as pulmonary dysfunctions (57%), renal dysfunctions (37%), shock (12%), and sepsis (26%) in spite of intensive care treatment. The median value of the early prognostic signs was 4.5 points. Intraoperatively, 62% of the patients revealed extensive intrapancreatic parenchymal necrosis, 69% had extrapancreatic necrosis, and 39% showed bacterial contamination of the necrotic material. Following the necrosectomy, postoperative local lavage was performed for an average period of 25 days with 7 liters (median) of lavage fluid per 24 hours. In each of 18 studied patients, a considerable release of immunoreactive trypsin was demonstrated and, in each of 20 studied patients, a high concentration of immunoreactive phospholipase A₂ was demonstrated in the lavage fluid up to the 12th/14th postoperative day. The intensive care period averaged 6 1/2 days, the hospital stay averaged 54 days. The hospital mortality rate was 8.1%. It is concluded that restricted necrosectomy and postoperative local lavage treatment correspond in particular to the pathomorphologic conditions and to the local release of biologically active compounds such as bacteria, endotoxin, trypsin, and phospholipase A₂ in patients with necrotizing pancreatitis.

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Resumen Setenta y cuatro pacientes con pancreatitis necrotizante fueron incluídos en un ensayo clínico prospectivo aplicando un protocolo de manejo quirÚrgico que comprende necrosectomía y lavado peritoneal postoperatorio de la transcavidad de los epiplones y de la cavidad necrótica. Cincuenta y ocho pacientes exhibierion fallas orgánicas postoperatorias tales como disfunción pulmonar (57%), disfunción renal (37%), shock (12%), y sepsis (26%) a pesar de cuidado intensivo. El valor promedio de los signos précoces pronóstico (Ranson), con exclusión de la retención de líquido fue de 4.5 puntos. Los hallazgos intraoperatorios revelaron necrosis pancreática extensa en 62% de los pacientes, necrosis extrapancreática en 69%, y contaminación bacteriana del material necrótico en 39%. Realizada la necrosectomía se instauró lavado peritoneal postoperatorio por un período promedio de 25 días con 7 litros (promedio) de líquido por cada 24 horas. En cada uno de los 18 pacientes estudiados se demostró liberación considerable de tripsina inmunorreactiva, así como una elevada concentración de fosfolipasa A₂ inmunorreactiva, en el líquido de lavado hasta el 12/14 días postoperatorios. El período de cuidado intensivo fue de 6 1/2 días, y la hospitalización de 54 días en promedio. La mortalidad hospitalaria fue de 8.1%. En conclusión, se plantea que el tratamiento mediante la necrosectomía restringida y el lavado peritoneal local postoperatorio está indicado en pacientes con las condiciones patomorfológicas de pancreatitis necrotizante que resultan en la liberación local de compuestos biológicamente activos tales como bacterias, endotoxina, tripsina, y fosfolipasa A₂. Serán necesarios ulteriores estudios clínicos controlados para confirmar los resultados favorables que hemos obtenido con la necrosectomía y el lavado peritoneal postoperatorio en pacientes con pancreatitis necrotizante y extensa e infectada necrosis pancreática.

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Résumé Un essai prospectif d'une méthode de traitement chirurgical consistant en nécrosectomie associée au lavage de l'arrière cavité des épiploons et de la cavité nécrotique a concerné 74 malades présentant une pancréatite nécrotique. Malgrè le traitement intensif 58 d'entre eux ont accusé des complications telles que troubles pulmonaires (57%), rénaux (37%), choc (12%), et infection (26%). La valeur moyenne des signes de pronostic précoce fut de 4.5 points. A l'intervention 62% des opérés présentaient une nécrose pancréatique étendue, 69% des opérés une nécrose extra-pancréatique, 39% une surinfection du tissu pancréatique. Après l'exèrése de la nécrose le lavage fut pratiqué quotidiennement avec en moyenne 7 litres de liquide pendant une période de 25 jours. Chez 18 malades fut constaté une libération importante de trypsine immunoactive et chez 20 malades un taux élevé de phospholipase cA dans le liquide de lavage pendant 12/14 jours après l'intervention. La durée des soins intensifs fut en moyenne de 6.5 jours et celle de l'hospitalisation de 54 jours. Le taux de mortalité opératoire fut de 8.1%. On peut conclure de ces faits que la nécrosectomie limitée, associée au lavage local constitue un traitement adapté aux lésions et à la libération locale d'éléments biologiques pathologiques: bactérie, endotoxine, trypsine, et phospholipase A au cours de la pancréatite nécrotique.

     

CO2 laser techniques in destruction of verrucae plantaris: discussion of the blister technique, a more complete method of wart ablation

The popular "Cross-hatch" method of CO2 laser surgery is compared with the "blister" technique of verrucae destruction. The blister technique provides greater reliability of wart tissue destruction through better visualization of normal skin lines and verrucoid tissue. The procedure can be performed quickly and easily, and is less painful to the patient than other conventional methods of wart destruction.