结肠肿瘤细胞株体外培养过程中的自发性凋亡的观察

研究了Ｖ２３５Ｅ、Ｖ２３５Ｌ、Ｖ４１１三个结肠肿瘤细胞株的细胞凋亡现象。ＤＮＡ电泳分析和ＡＯ／ＥＢ荧光染色形态学检查表明，这三个肿瘤细胞株均存在自发性凋亡。提示肿瘤细胞，包括恶变的癌细胞仍可保留与增殖相对立的凋亡过程。肿瘤细胞存在自发性细胞凋亡的观察，有助于更好地认识肿瘤的发生和发展过程。此外，这些细胞株也为进一步研究细胞凋亡的诱导及其调控提供了有用的细胞模型。     

Synthesis and post-translational modification of the androgen receptor in LNCaP cells

Androgen receptor synthesis and modification were studied in the human LNCaP cell line. Immunoblotting with a specific polyclonal antibody showed that the androgen receptor migrated as a closely spaced 110–112 kDa doublet on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. Most of the receptor protein is present in the higher molecular mass form. Pulse labelling experiments with [³⁵S]methionine showed that the androgen receptor is synthesized as a single 110 kDa protein which is rapidly converted to a 112 kDa protein. Alkaline phosphatase treatment of cytosols from [³⁵S]methionine pulse labelled cells caused a gradual elimination of the 112 kDa isoform with a concomitant increase of the 110 kDa isoform. This indicates that the observed 110 to 112 kDa upshift of the newly synthesized androgen receptor reflects receptor phosphorylation. Both isoforms can bind hormone and can undergo a hormone dependent transformation to a tight nuclear binding form, indicating that the 110 to 112 kDa conversion is not an obligatory step for hormone binding or receptor transformation.     

In Vitro Growth of Thymic Tumor Cell Lines from Xenopus

A spontaneous lymphoid thymus tumor was discovered in a male Xenopus of the MHC ff genotype. The tumor cell can be transplanted in histocompatible larval ff hosts, but not in ff adults unless irradiated (3000 rad). The tumor is rejected by allogeneic hosts. The tumor cells express neither markers of the B-cell lineage nor MHC encoded molecules; they express only markers of the T-cell lineage. Its lymphoid population is clonal as revealed by the existence of a stable rearrangement pattern of the immunoglobulin genes. Cell lines growing continuously in vitro have been derived from the tumor.     

Experimental study of spinal cord compression by epidural tumors using electron probe X-ray microanalysis and confocal laser scanning microscopy

Changes in the nerve fibers of the spinal cord were studied in rat experimental epidural tumor models. Light microscopy showed demyelinization in all with rats paraparesis and paraplegia. Cross-sectional views of nerve fibers stained with 3,3dipentyloxacarbo-cyanine iodide, obtained by confocal laser scanning microscopy, showed distorted, shrunken fibers with a low fluorescence intensity. Changes in the electrolyte contents of nerve fibers were studied by electron probe X-ray microanalysis. The K concentration in axons and the myelin sheath was increased in the paraparesis group, but was decreased in the paraplegia group. These findings suggest that, in the paraparesis group, compression of the spinal cord damaged cell membrane channels, which subsequently caused an increase in intracellular K, a decline in the action potential, and low-intensity fluorescence of nerve fibers. On the other hand, in the paraplegia group, destruction of cell membranes caused a decrease in intracellular K until it approached the extracellular level. This reduced both the action potential and the fluorescence intensity. As Ca and Mg concentrations in both axons and the myelin sheath increased in relation to the severity of neurologic damage, it appears that these electrolytes may also play an important role in damage to nerve fibers.     

Second nonocular tumors in cured unilateral retinoblastoma patients

Summary According to recent data the incidence of second tumors in cured hereditary unilateral retinoblastoma patients is 20% within 10 years, 50% after 20 years and rises to 90% after 30 years. Nonhereditary unilateral retinoblastoma patients have not been regarded as susceptible for second nonocular tumors so far. A case is reported of such a patient having developed a second presacral retroperitoneal tumor after successful treatment of a nonhereditary unilateral retinoblastoma group V without intracranial extension or pulmonary metastases. Consequently all (hereditary and non-hereditary) retinoblastoma patients should receive at least quarterly intensive follow-up examinations after primary ophthalmologic treatment.     

Splanchnic ischaemia and its role in multiple organ failure

Multiple organ failure remains the leading cause of death in the intensive care unit. Increasing numbers of investigators have focused their attention on the role of gastrointestinal tract in the pathogenesis of this syndrome. Their data indicate that inadequate gut perfusion leads to a measurable imbalance between oxygen delivery and the needs of the tissues, i.e., ischaemia. Gut ischaemia of sufficient duration impairs gastrointestinal tract barrier function, facilitating the passage of enteric bacterial endotoxin into the circulation. It has been hypothesized that production of tumor necrosis factor α, and other biologic mediators by endotoxin–stimulated macrophages, triggers a generalized and uncontrolled inflammatory response that ultimately leads to multiple organ failure.
Preliminary evidence suggests that survival can be improved significantly if gut ischaemia is promptly identifed and aggressively treated by administration of fluids and inotropic drugs, using gastric intramucosal pH as the therapeutic endpoint. Future studies are needed to determine whether additional treatment modalities can improve outcome once the inflammatory response has fully developed.     

In vitro radiation sensitivity of the lncap prostatic tumor cell line

Because there is extremely limited information on the intrinsic radiosensitivity of human prostatic cancer cells, we have investigated the in vitro radiation response of exponentially growing LNCaP cells. Due to the very poor colony-forming potential of the LNCaP cells, radiation survival was investigated using the dose-dependent (0-6 Gy) changes seen after X-irradiation in the shapes of regrowth curves. Survival was described using both the single-hit, multitarget (SHMT) equation and the linear-quadratic (LQ) equation. The values and 95% confidence limits of the extrapolation number (n), quasi-threshold dose (D_q), and mean lethal dose (D_o) in SHMT terminology were respectively: 0.9 (0.7-1.0), 0.0 Gy, and 1.39 (0.11) Gy. The LQ alpha and beta parameters were respectively 6.80 (1.13) and -0.53 (2.89). The X-ray dose response of the LNCaP line is, therefore, purely exponential. The mean survival at the clinically relevant dose of 2 Gy (S₂) was 51.2% for the LNCaP line. Comparison of the S₂ value for the LNCaP line with previous investigations with other human prostatic cancer cell lines (DU145 and PC-3) indicates a mean S₂ value of 47.6%, which suggests that human prostate cancer cells might lie toward the resistant side of the spectrum for various classes of human neoplasms. © 1994 Wiey-Liss, Inc.     

数字化曲面全景X线系统造影在腮腺非肿瘤类疾病诊断中的应用

目的　本文报告普通X线机腮腺造影与数字化曲面X线机腮腺造影结果及其对比应用。方法　用3种不同的X线机对 3组腮腺非肿瘤类疾病患者进行腮腺造影 ,第 1组患者 10人应用普通 30 0mAX线机 ,第 2组患者 10人应用普通曲面全景X线机 ,第 3组患者 36人应用数字化曲面全景X线系统一套 ,分别行造影检查。结果腮腺造影侧位投照第 2组与第 1组末梢导管及腺泡有显著差异 (P <0 .0 5 ) ,第 3组与第 1组末梢导管及腺泡无显著差异 (P >0 .0 5 ) ,腮腺造影后前位投照第 2组与第 1、3组之间有显著差异 (P <0 .0 5 )。结论　本研究对比了 3种X线投照技术在腮腺非肿瘤性疾病造影诊断中的效果 ,用数字化曲面全景X线系统造影在诊断此类疾病中显示出较好的效果。     

Geometric Resistance and Microvascular Network Architecture of Human Colorectal Carcinoma

Objective : To measure the geometric resistance to blood flow in human colorectal carcinoma. Although tumor blood flow is of central importance in both the detection and the treatment of cancer, the determinants of blood flow through the neoplastic circulation are poorly understood. Methods : Human colorectal carcinomas (tissue weight = 272 g ± 43 g (SD), n = 6) were perfused ex vivo with a buffered physiological salt solution of known viscosity at flow rates ranging from 2.5 to 40 ml/min and perfusion pressures from 8 to 100 mm Hg. The geometric resistance was determined from the slope of the pressure-flow curve. For examination of the principal determinant of geometric resistance, the vascular architecture, one of the tumors was perfused with Batson's No. 17 polymer and macerated in KOH to produce a positive vascular cast that was used for measurement of vascular branching patterns and dimensions. Results : The pressure-flow relationship was linear at perfusion pressures above 40 mm Hg, and the geometric resistance, z₀, was constant at approximately 6.5 ± 10⁹g/cm³. Below 40 mm Hg, z₀ increased rapidly. The architecture of the arteriolar and capillary networks of human colorectal carcinoma is similar to those of experimental rodent tumors. Capillaries in planar and nonplanar mesh-works had mean segment diameters of 11 ± 2 and 9.6 ± 2 μm, lengths of 46 ± 24 and 107 ± 40 μm, and intercapillary distances of 46 ± 13 and 74 ± 24 μm, respectively. Conclusions : The geometric flow resistance in neoplastic tissue is 1–2 orders of magnitude higher than that observed in normal tissues. A decrease in functional vascular cross-sectional area may explain the additional increase in resistance at small perfusion pressures. The observed flow resistance may be due to the specialized arteriolar and capillary network architecture, pressures exerted by proliferating cancer cells, and/or coupling between vascular and extravascular flow. These observations demonstrate that tumor vascularity alone may not be indicative of flow resistance or tumor susceptibility to blood-borne therapeutic agents.     

Resection of pulmonary metastases following chemotherapy for high stage testicular tumors

BACKGROUND: Our objective was to analyze retrospectively our experience with 19 patients who had metastatic germ cell testicular tumor and had undergone resection of pulmonary metastases following chemotherapy. We wished to determine the necessity of thoracic surgery on these patients. METHODS: Of 103 patients in need of postchemotherapeutic surgery for metastatic germ cell testicular tumors, 19 patients (mean age 31) underwent surgery for thoracic masses following cis-platin based chemotherapy. Resection of pulmonary metastases was performed on patients with normal tumor markers after chemotherapy, who did not achieve complete radiological remission. Histopathological findings, correlation with the pathology of abdominal surgery and probable prognostic factors for disease-free and overall survivals were evaluated. RESULTS: Disease-free and overall survival rates were 14/19 (73%) and 16/19 (84%), respectively, within a median follow-up time of 30 months (15-212 months). Patients with and without viable tumor cells in their thoracic histopathological specimen had 40% and 85% disease-free survival rates, respectively (P < 0.05). Eight patients had both abdominal and thoracic postchemotherapy surgery. Only two (25%) of these patients had the same histopathological features at both sites. CONCLUSIONS: All patients with residual thoracic masses must be considered candidates for surgery, because there are no predictive factors to determine the thoracic pathology without surgery. With the resection of the pulmonary metastases only, surgery can be performed without significant morbidity and is essential to select patients for further chemotherapy, to remove all visible masses and to provide histopathological confirmation. Patients with viable tumor cells in the thoracic surgical specimen have a poor prognosis.