赛赓啶对 KBV200细胞多药抗性的逆转作用

研究赛赓啶对KB_V200细胞多药抗性的逆转作用及逆转机制。在KB_V200细胞,采用MTT法,测出赛赓啶对长春新碱、阿霉素和鬼臼乙叉甙耐药的逆转系数分别为5.5,2.0和1.9,而对5-氟尿嘧啶、美法仑的细胞毒性作用无明显影响,表明赛赓啶为多药抗性逆转剂。荧光分光光度法测定表明,赛赓啶可使KB_V200细胞内阿霉素蓄积量增加。流式细胞荧光测定显示赛赓啶可增加罗丹明123的蓄积并减慢其外排。免疫细胞化学及狭缝杂交表明赛赓啶不影响KB_V200细胞的P-糖蛋白染色深度和 mdr1 RNA 表达水平。以上结果提示赛赓啶的多药抗性逆转机制是抑制P-糖蛋白泵的功能。     

Fidgetin-like 1 gene inhibited by basic fibroblast growth factor regulates the proliferation and differentiation of osteoblasts.

The FIGNL1 gene was proven to be a new subfamily member of ATPases associated with diverse cellular activities (AAA proteins). In this in vitro study, the AAA proteins inhibited osteoblast proliferation and stimulated osteoblast differentiation. We showed that FIGNL1 may play some regulatory role in osteoblastogenesis. INTRODUCTION: The fidgetin-like 1 (FIGNL1) gene encodes a new subfamily member of ATPases associated with diverse cellular activities (AAA proteins). Although the FIGNL1 protein localizes to both the nucleus and cytoplasm, the function of FIGNL1 remains unknown. In a previous study, we identified several genes that mediate the anabolic effects of basic fibroblast growth factor (bFGF) on bone by using microarray data. FIGNL1 was one of the genes that downregulated >2-fold in MC3T3-E1 cells after treatment with bFGF. Therefore, this study was aimed to identify and confirm the function of FIGNL1 on osteoblastogenesis. MATERIALS AND METHODS: We examined the effect of the FIGNL1 gene on proliferation, differentiation, and apoptosis in mouse osteoblast cells (MC3T3-E1 and mouse primary calvarial cells) using flow cytometry, RT-PCR, cell proliferation assay, and cell death assay. MC3T3-E1 cells and mouse calvarial cells were transfected with small interfering RNA (siRNA) directed against the FIGNL1 or nontargeting control siRNA and examined by cell proliferation and cell death assays. Also, FIGNL1 was fused to enhance green fluorescent protein (EGFP), and the EGFP-fused protein was transiently expressed in MC3T3-E1 cells. RESULTS: Reduced expression of FIGNL1 by bFGF and TGF-beta1 treatment was verified by RT-PCR analysis. Overexpression of FIGNL1 reduced the proliferation of MC3T3-E1 and calvarial cells, more than the mock transfected control cells did. In contrast, siFIGNL1 transfection significantly increased the proliferation of osteoblasts, whereas overexpression of FIGNL1 did not seem to alter apoptosis in osteoblasts. Meanwhile, overexpression of FIGNL1 enhanced the mRNA expression of alkaline phosphatase (ALP) and osteocalcin (OCN) in osteoblasts. In contrast, siFIGNL1 decreased the expression of ALP and OCN. A pEGFP-FIGNL1 transfected into MCT3-E1 cells had an initially ubiquitous distribution and rapidly translocated to the nucleus 1 h after bFGF treatment. CONCLUSIONS: From these results, we proposed that FIGNL1, a subfamily member of the AAA family of proteins, might play some regulatory role in osteoblast proliferation and differentiation. Further analyses of FIGNL1 will be needed to better delineate the mechanisms contributing to the inhibition of proliferation and stimulation of osteoblast differentiation.     

华蟾蜍毒素对离体豚鼠输精管的作用

华蟾蜍毒素(华蟾素)使离体豚鼠输精管产生剂量依赖性收缩反应,利血平化豚鼠输精管及冷藏输精管对华蟾素反应减弱。给酚妥拉明、维拉帕米后,输精管对华蟾素反应均受抑制,溴苄胺可使反应潜伏期缩短。结果提示华蟾素收缩输精管反应可能与其促进肾上腺素能神经末稍NA释放有关。     

Simple Partial Status Epilepticus Localized by Single-Photon Emission Computed Tomography Subtraction in Chronic Cerebral Paragonimiasis

A patient with chronic cerebral paragonimiasis began to have new motor seizures of the right face manifested by clonic contractions that occurred several hundred times a day, consistent with simple partial status epilepticus. Ictal electroencephalogram discharges started from the left frontal region and then spread to the left hemisphere with left frontal maximum. But clinical seizures were limited to the right face. The frequent partial seizures were controlled by the intravenous infusion of phenytoin. Brain magnetic resonance imaging showed multiple conglomerated round nodules with encephalomalacia in the left temporal and occipital lobes. Applying the technique of ictal-interictal single-photo emission computed tomography subtraction, the authors were able to localize the focal ictal-hyperperfusion on left precentral cortex adjacent to the lesions that correspond to the anatomical distribution of left face motor area.     

Disseminated neonatal herpes simplex virus infection with necrotizing encephalitis--an autopsy case

An autopsy case of disseminated HSV type 2 infection occurring in a neonate at 32 weeks' gestation, delivered by cesarean section after premature rupture of membrane of 7 days duration, is presented. Herpes simplex virus type 2 was isolated from the vesicular skin lesion. The mother and patient had specific antibody to type 2 herpes simplex virus. Patient's parents had denied any herpetic orolabial or genital lesion during or before this pregnancy. Cultures from the cervical and vaginal swabs of the mother were negative for HSV. Postmortem examination showed hepatic necrosis, skin vesicle, devastating necrotizing inflammation of the brain, chorioretinitis and interstitial pneumonitis.     

An effective pharyngoesophageal reconstruction with free radial forearm flaps

Summary Treatment of cancer of the cervical aerodigestive tract is challenging due in part to the difficulty in reestablishment of pharyngoesophageal continuity after resection of the involved tract. From May 1989 to August 1990, six patients underwent immediate reconstruction utilizing microvascular transfer of free radial forearm flaps following resection of pharyngoesophageal neoplasms. A small island flap connected to the radial vascular pedicle by fasciocutaneous branch was used to monitor the vascular condition of the hidden fabricated free forearm flap. Stricture is the most troublesome complication of esophageal reconstruction using a conventional free forearm flap. Two small triangular flaps were designed and inserted bilaterally in the distal anastomosis of both lateral esophageal walls to prevent circular contracture. The outer layer sutures were anchored to surrounding rigid structures to withstand shrinkage and circular contraction. The problem of stricture was solved by these procedures. This one-stage, easily monitored operation for pharyngoesophageal reconstruction is considered to be as useful as a free jejunal transfer.     

The immunomodulatory effects of 3-monochloro-1,2-propanediol on murine splenocyte and peritoneal macrophage function in vitro.

3-Monochloro-1,2-propanediol (MCPD) is a well-known by-product of acid-hydrolyzed soy sauce during its manufacturing process. MCPD has been reported genotoxic in vitro, and reproductive toxicity and carcinogenicity in rats. To evaluate the immunomodulatory effect of MCPD on murine splenocyte and macrophage in vitro, we investigated splenocyte blastogenesis by concanavalin A (Con A), anti-CD3, and lipopolyssacharide (LPS), the production of cytokines from splenocyte, and the activity of mouse peritoneal macrophages. There was a significant decrease in lymphocyte blastogenesis to Con A or anti-CD3 at subtoxic dose of MCPD. A significant decrease in splenocyte blastogenesis to LPS was also observed. The production level of interferon (IFN)-gamma on splenocyte culture with Con A was significantly reduced at the higher concentration than 1.0mM of MCPD. The levels of interleukin (IL)-4 and IL-10 were also decreased at high concentrations of MCPD. There was a significant decrease in production of nitric oxide (NO) by peritoneal macrophages treated with MCPD. MCPD also inhibits tumor necrosis factor (TNF)-alpha production of stimulated macrophages. These results indicate that MCPD might be able to reduce the functionality of lymphocytes and peritoneal macrophages in vitro.     

Functional uncoupling of MCM helicase and DNA polymerase activities activates the ATR-dependent checkpoint

The ATR-dependent DNA damage response pathway can respond to a diverse group of lesions as well as inhibitors of DNA replication. Using the Xenopus egg extract system, we show that lesions induced by UV irradiation and cis-platinum cause the functional uncoupling of MCM helicase and DNA polymerase activities, an event previously shown for aphidicolin. Inhibition of uncoupling during elongation with inhibitors of MCM7 or Cdc45, a putative helicase cofactor, results in abrogation of Chk1 phosphorylation, indicating that uncoupling is necessary for activation of the checkpoint. However, uncoupling is not sufficient for checkpoint activation, and DNA synthesis by Polalpha is also required. Finally, using plasmids of varying size, we demonstrate that all of the unwound DNA generated at a stalled replication fork can contribute to the level of Chk1 phosphorylation, suggesting that uncoupling amplifies checkpoint signaling at each individual replication fork. Taken together, these observations indicate that functional uncoupling of MCM helicase and DNA polymerase activities occurs in response to multiple forms of DNA damage and that there is a general mechanism for generation of the checkpoint-activating signal following DNA damage.     

Expression of interleukin-6 in polymorphic reticulosis--immunohistochemical study of 5 cases.

Peripheral T cell lymphoma encompasses lymphomas with a variety of histologic appearances and clinical patterns. Recently, it has been suggested that almost all of the histologic features described under the name of polymorphic reticulosis(PR), lethal midline granuloma, and midline malignant reticulosis can be included in those generally described for malignant lymphomas of peripheral T cell origin(PTCL). There have been few studies of pathogenesis or tissue damage mechanism in PR patients. The need for a precise mechanism for tissue damage has important therapeutic implications. Using immunohistochemical methods with polyclonal anti IL-6 antibody, the authors describe 5 cases of PR with clinically and pathologically typical PR demonstrating a high expression of IL-6. According to classification, 2 cases of grade 1 PR showed the highest expressions, and 2 cases of grade 2 PR with atypical lymphoid cells showed moderate activity, but one case progressed into frank lymphoma(grade 3) and lost IL-6 expression. This strongly implies that some cases of PR have a different mechanism of tissue damage from frank PTCL, despite the one disease spectrum. Further studies on more cases may help clarify the pathogenesis.