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941.
BACKGROUND/PURPOSE: The development of thoracoscopic surgery has made many procedures possible, including the treatment of mediastinal cysts in children. The authors report their experience with this procedure between 1992 and 1997. METHODS: Surgery was performed on 22 children aged from 1 month to 9 years (median, 27 months), weighing 5 to 49 kg (median, 12.5 kg). Diagnosis was made by antenatal ultrasound scan in six cases (27%), with a chest x-ray performed for respiratory symptoms in 14 cases, and with a chest x-ray performed for positive tuberculin intradermoreaction in two cases. Decision to resect the cyst was determined by thoracoscopy in 21 of the 22 cases, and by open surgery in one case only (subcarinal compressive cyst with left lung distension and a mediastinal shift). RESULTS: Eighteen of the 21 (86%) cases were treated successfully by thoracoscopy. In three cases of bronchogenic cysts, we performed an associated thoracotomy because the dissection was too difficult and dangerous. In three cases, a small part of a common wall between the cyst and the bronchus was not removed. The pathological diagnosis was bronchogenic cysts in 15 cases (71%), pleuropericardiat cysts in three cases (14%), esophageal duplication in two cases (10%), and cystic hygroma in one case (5%). Two postoperative complications were observed: one esophageal wound and a case of recurrent pneumothorax after chest tube removal. Patients were discharged after 2 to 11 days (median, 3 days). Follow-up was uneventful. CONCLUSIONS: Treatment of mediastinal cyst by thoracoscopy is feasible in most cases. Compressive cysts with lung distension and mediastinal shift remain a contraindication. If the cysts have a common wall with the bronchus or esophagus, or if they are subcarinal, the dissection may be difficult and dangerous, and thoracotomy may be preferable.  相似文献   
942.
The external region of a cell membrane, known as the glycocalyx, is dominated by glycosylated molecules, which direct specific interactions such as cell-cell recognition and contribute to the steric repulsion that prevents undesirable non-specific adhesion of other molecules and cells. Mimicking the non-adhesive properties of a glycocalyx provides a potential solution to the clinical problems, such as thrombosis, that are associated with implantable devices owing to non-specific adsorption of plasma proteins. Here we describe a biomimetic surface modification of graphite using oligosaccharide surfactant polymers, which, like a glycocalyx, provides a dense and confluent layer of oligosaccharides. The surfactant polymers consist of a flexible poly(vinyl amine) with dextran and alkanoyl side chains. We show that alkanoyl side chains assemble on graphite through hydrophobic interaction and epitaxial adsorption. This constrains the polymer backbone to lie parallel to the substrate, with solvated dextran side chains protruding into the aqueous phase, creating a glycocalyx-like coating. The resulting biomimetic surface is effective in suppressing protein adsorption from human plasma protein solution.  相似文献   
943.
BACKGROUND: In an effort to intensify osteosarcoma therapy, systemic ifosfamide was added pre- and postoperatively to an already aggressive three-drug regimen. In a subgroup of patients, loco-regional treatment intensification was attempted by using the intraarterial route to give cisplatin. PATIENTS AND METHODS: Patients < or = 40 years at diagnosis of a localised, de novo high-grade central extremity osteosarcoma were eligible for inclusion into study COSS-86 if registered within three weeks from biopsy. Doxorubicin, high-dose methotrexate, and cisplatin were given to all patients. Patients who fulfilled one or more of three defined high-risk criteria received early systemic treatment intensification by adding ifosfamide as the fourth agent. Preoperatively, these high-risk patients received cisplatin either intraarterially or intravenously. RESULTS: 171 eligible patients were entered, of which 128 were stratified into the high-risk group. When all 171 were analysed by intention-to-treat, actuarial overall and event-free survival rates at ten years were 72% and 66%, respectively. No benefit of intraarterial cisplatin application was detected. Cumulative treatment toxicity was considerable. CONCLUSIONS: In a multicenter setting, intensive treatment of osteosarcoma according to protocol COSS-86 led to long-term disease-free survival for two thirds of patients. We saw no benefit of using the intraarterial route to administer cisplatin.  相似文献   
944.
HL-60 cells derived from a human promyelocytic leukemia underwent apoptosis by heat treatment. When the heat-treated HL-60 cells were injected into guinea pig skin, monocyte/macrophage infiltration was observed 24 or 36 hours later, and the apoptotic cells were phagocytically cleared by 48 hours after their injection. The infiltration and clearance patterns were quite different from those observed in injection of necrotic or boil-fixed HL-60 cells. The apoptotic cells released a monocyte chemotactic factor in vitro 24 hours after the heat treatment. The chemotactic factor generated was identified as the cross-linked homodimer of S19 ribosomal protein by its immunologic and physicochemical properties. A serine protease that inactivates the monocyte chemotactic factor was also released from the apoptotic cells 30 hours after the heat treatment. A super infusion of this protease into the skin where the apoptotic cells had been injected diminished the number of infiltrated monocytes. The present results indicate an important role of the S19 ribosomal protein dimer in the phagocytic clearance of apoptotic cells.  相似文献   
945.
BACKGROUND: We report experience with patients presenting with a specific combination of symptoms: unilateral sciatica, unilateral sensibility loss in the dermatomes S1 to S5 (hemi-saddle) and subjective micturation problems secondary to ruptured lumbar disc. Because of its similarities with a cauda equina syndrome, this combination of symptoms was thought to be a unilateral cauda equina syndrome and it was called hemi-cauda equina syndrome. Consequently, it was treated as an emergency. METHODS: Ten patients were evaluated. They compromised 2.3% of all patients undergoing lumbar discectomy. RESULTS: Outcome is good with only 10% persisting minor neurologic deficit (sensibility loss in dermatomes S3 to S5). With the exception of urinary retention or incontinence, duration of symptoms and signs does not seem to influence outcome. Comparing signs, symptoms and radiographic findings with those of a cauda equina syndrome which were recently and thoroughly studied, they were found to be more severe in cases of cauda equina syndrome. Especially, the good outcome, (apparently unrelated to the duration of symptoms in cases of hemi-cauda equina syndrome) contrasted with the treatment results of cauda equina syndrome. CONCLUSIONS: We defined the hemi-cauda equina syndrome from ruptured disc as a combination of unilateral leg pain, unilateral sensibility loss in dermatomes S1 to S5 and sphincter paralysis (proven urinary retention or incontinence). Motor deficit is not necessarily present. Emergency surgery is warranted. Patients presenting with micturation complaints other than urinary retention or incontinence do not suffer from a hemi-cauda equina syndrome.  相似文献   
946.
Ligand binding to neurotransmitter and hormone receptors which couple to the Gq subclass of GTP-binding protein leads to the activation of phospholipase Cbeta (PLCbeta) which hydrolyses phosphatidyl-inositol 4,5-bisphosphate, yielding a pair of second messengers, diacylglycerol and inositol 1,4,5-trisphosphate (IP3). The expression of PLCbeta1-4 mRNAs was comparatively examined by in situ hybridization in the mouse brain. In adults, PLCbeta1 mRNA was expressed predominantly in the telencephalon, including the cerebral cortex, hippocampus, amygdala, lateral septum and olfactory bulb, with little expression in most thalamic nuclei. PLCbeta2 mRNA was distributed in the white matter, suggesting its expression in non-neuronal cells, most likely oligodendrocytes. PLCbeta3 mRNA was specifically expressed in cerebellar Purkinje cells. The highest levels of PLCbeta4 mRNA were detected in Purkinje cells. High levels of PLCbeta4 mRNA were also found in the thalamus and medial septum, whereas weak signals were detected in most telencephalic regions, thus showing an expression pattern almost reciprocal to that of PLCbeta1 mRNA. During development, such characteristic regional expression of PLCbeta1 and PLCbeta4 were observed starting in late foetal stages, while specific expression of PLCbeta2 and PLCbeta3 appeared in early postnatal stages. We conclude that despite the existence of four PLCbeta isoforms, only one or two of them is expressed in individual neurons and glial cells. The distinct expression of PLCbetas provides a molecular basis for analysing the nature of the specific signal transduction pathway leading to the production of diacylglycerol and IP3 in distinct cell types and in different regions of the brain.  相似文献   
947.
The cytotoxic effects of beta-thujaplicin and five kinds of metal chelates were examined on mouse melanoma B16BL6 cells by cell viability and lactate dehydrogenase (LDH) release assay. Beta-thujaplicin-zinc chelate and beta-thujaplicin-copper chelate had higher cytotoxic effects than beta-thujaplicin, and the 50% effective doses (ED50) of these metal chelates were 12.5 and 25 microM, respectively. In addition, the zinc chelate induced DNA ladder formation in B16BL6 cells, as shown by the DNA fragmentation assay, suggesting that cell death induced by the zinc chelate is apoptosis. The zinc chelate also had a cytotoxic effect and induced DNA fragmentation on other tumor cell lines: HeLa, Meth A, and B16F1 cells, but not on normal human diploid fibroblasts FS-4. These results suggest that beta-thujaplicin-zinc chelate induces apoptotic cell death in various tumor cell lines and is a potent antitumor agent for tumor cells including malignant melanomas.  相似文献   
948.
After intravenous administration of the vitamin D3 analog, 22-oxacalcitriol (OCT), to normal rats plasma metabolites were investigated by HPLC, GC-MS and LC-MS. Five side-chain oxidation metabolites, 24R(OH)OCT, 24S(OH)OCT, (25R)-26(OH)OCT, (25S)-26(OH)OCT and 24oxoOCT, were identified by comparison with the corresponding synthetic compounds. These side-chain oxidation metabolites were similar to those of calcitriol [1alpha,25(OH)2 vitamin D3] described previously. Besides these five metabolites, two unique side-chain cleavage metabolites, 20S(OH)-hexanor-OCT and 17,20S(OH)2-hexanor-OCT, were identified as main metabolites in plasma by GC-MS and LC-MS using a specific chemical reaction. Our studies suggest that OCT is extensively metabolized and circulates in blood as a number of metabolites as well as unchanged OCT. This metabolism includes both unique pathways of C23-O22 cleavage and 17-hydroxylation, in addition to the side-chain oxidation metabolites similar to those of 1alpha,25-(OH)2D3.  相似文献   
949.
This paper describes a flexible random allocation program that assigns treatments to patients according to their prognostic factors in multi-institutional clinical trials. The source lists are available in the appendix of this paper. This program is based on Pocock and Simon's minimization method and Zelen's method for institution balancing. The numbers of institutions, treatments, and prognostic factors can be set arbitrarily. The maximum number of institutions, treatments, or prognostic factors that can be accommodated by the program is limited only by the size of the main memory. For example, an IBM-PC with a 640KB main memory can run a program of 1500 institutions, 4 treatments and 20 prognostic factors.  相似文献   
950.
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