Infrequent microsatellite instability in liver fluke infection-associated intrahepatic cholangiocarcinomas from Thailand

The liver fluke infection-associated intrahepatic cholangiocarcinoma (ICC) is a major liver cancer in Northeast Thailand. The molecular basis of this ICC is poorly understood. To address possible roles of the DNA mismatch repair (MMR) system in ICC carcinogenesis, a fluorescence-labeling PCR/laser scanning technique with high sensitivity was employed to analyze genomic instability in the nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) in 24 fresh and 13 formalin-fixed, paraffin-embedded tissues of ICC and their corresponding normal parts. Microsatellite instability (MSI) was assessed in nDNA, using 12 highly polymorphic loci including 5 Bethesda markers. These loci were mainly related to major MMR genes, hMSH2 and hMLH1. Also 3 (C)n and/or (C)n(A)n repeat instability at 1 noncoding region in the displacement-loop (D-loop) and 2 coding sequences in NADH dehydrogenase subunit 1 and subunit 5 gene in mtDNA were analyzed. MSI was only detected in 1 (2.7%), 6 (16.7%), 1 (2.9%), 1 (2.9%) or 2 (6.3%) out of 37, 36, 35, 35 or 32 cases at BAT-25, D2S123, D3S1611, D11S904 or D17S250, respectively. LOH was found at D3S1298, D3S1561, D5S346 and TP53 in 4 (18.2%) out of 22, 2 (18.2%) out of 11, 6 (33.3%) out of 18 and 3 (12.5%) out of 24 informative cases, respectively. In mtDNA, none except a single case out of the 37 (2.7%) exhibited repeat sequence instability in the D-loop. We conclude that the liver fluke infection-associated ICC in Thailand is classified as low frequency MSI or microsatellite stable type and that DNA MMR system, through hMSH2 and hMLH1 gene mutations, does not play a major role in its carcinogenesis.     

Effect of muscle tensing on cerebral oxygen status during sustained high +Gz

BACKGROUND: Successful monitoring of oxyhemoglobin during +Gz exposure was recently achieved using near-infrared spectroscopy (NIRS). To assess the effects of muscle tensing on sustained +Gz tolerance, we measured muscle activity and cerebral oxygen status (COS) during anti-G straining maneuvers at sustained high +Gz. METHOD: We exposed 21 male pilots wearing CSU-13/P anti-G suit to two different centrifuge profiles: 1) short-term repeated exposure (5 to 20 s) at 4, 5, 6, 5.5, or 7 Gz; 2) sustained exposure to a + 7Gz plateau for 30 s. During the Gz exposures, surface electromyographic (EMG) measurements were taken from the vastus medialis (VM) and rectus abdominis (RA) muscles. At the same time, the COS was recorded from the left forehead area using a commercial NIRS system. Mean muscular tensing for each muscle was calculated as a percentage of maximal voluntary contraction (% MVC). RESULTS: Oxyhemoglobin (O2Hb) and total hemoglobin (sum of O2Hb and deoxyhemoglobin) were decreased during both short-term and sustained +Gz exposure. RA muscle tensing was positively correlated with changes in the concentration of O2Hb during sustained + 7Gz exposure (r = 0.540, p < 0.05). RA tensing ranged from 6.2 to 36.8%MVC, and O2Hb ranged from -41.3 to -7.28 micromol x L(-1) during the exposures. No significant correlation was observed between VM tensing and O2Hb. CONCLUSION: NIRS measurements confirmed that a muscle straining maneuver increases G tolerance. Higher RA muscle tensing helps preserve brain blood volume during sustained high +Gz.     

Cancer gene therapy with HSV-tk/GCV system depends on T-cell-mediated immune responses and causes apoptotic death of tumor cells in vivo.

To examine the immunological mechanisms involved in cancer gene therapy using the herpes simplex virus thymidine kinase (HSV-tk) gene and ganciclovir (GCV), murine hepatocellular carcinoma (HCC) cells, BNL1ME A.7R.1, were transduced retrovirally with the HSV-tk gene. HSV-tk-transduced cells exhibited a more than 2,000-fold higher sensitivity to GCV compared with untransduced parental cells. When HSV-tk-transduced HCC cells were mixed with parental cells at a 50% ratio and implanted subcutaneously into immunocompetent syngeneic mice, complete inhibition of tumor formation was achieved by GCV treatment. Conversely, no significant inhibitory effects on tumor formation were observed in athymic nude mice. When established solid tumors in immunocompetent mice containing HSV-tk-transduced cells at an only 5% ratio were treated with GCV, marked infiltration by lymphocytes including CD4(+) and CD8(+) ones, and apoptotic death of tumor cells were induced, and significant reduction or even complete regression of tumors was achieved. Furthermore, such cured mice rejected rechallenge with parental HCC cells into the contraflank regions. Our results indicate that cancer gene therapy with the HSV-tk/GCV system can indeed induce efficient antitumor effects and protective immunity in immunocompetent mice but not in nude mice, indicating that T-cell-mediated immune responses may be a critical factor for achieving successful gene therapy against cancer using the HSV-tk/GCV system.     

Hepatocellular carcinoma in an orthotopic mouse model metastasizes intrahepatically in cirrhotic but not in normal liver

Prognosis of hepatocellular carcinoma (HCC) still remains poor mainly because of intrahepatic metastasis. In the majority of cases, HCC is found in conjunction with liver cirrhosis. It is, therefore, of great importance to investigate the invasive and metastatic behavior of HCC in cirrhotic liver. To examine this, a liver cirrhosis model was produced by injecting thioacetamide i.p. into mice. Murine HCC cells were labeled with the fluorescent carbocyanine dye, DiI, and implanted directly under the capsule of cirrhotic and normal livers of syngeneic mice. DiI‐labeled HCC cells in the liver were observed under fluorescent and confocal microscopy. Histological analysis of cirrhotic and normal livers revealed that implanted HCC cells migrated to and invaded the adjacent periportal regions, but not the adjacent centrolobular areas. This characteristic behavior of HCC was more evident in cirrhotic liver than in normal liver. Furthermore, intrahepatic metastasis to unimplanted hepatic lobes was observed in cirrhotic liver as early as 7 days after implantation, while it was not detected in normal liver even 4 weeks later. Thus, an orthotopic animal model for HCC with cirrhosis described here may be suitable for investigating the invasive and metastatic behavior of HCC. Importantly, labeling tumor cells with a fluorescent dye before orthotopic implantation may be a convenient and useful method to investigate the invasive and metastatic behavior of various types of cancer. Int. J. Cancer 80:471–476, 1999. © 1999 Wiley‐Liss, Inc.     

The evaluation of ultrasonic oocyte collection techniques for IVF-ET--comparing the transabdominal and transvaginal methods

In order to evaluate the effectiveness and safety of ultrasonic oocyte collection for IVF-ET, a comparative study was performed on the results of IVF-ET by the transabdominal and transvaginal methods in 145 cycles of 51 patients. The oocyte collection rate for the transvaginal method was significantly higher than that for the transabdominal method (77.1% vs. 68.7% per follicle, p less than 0.01). The majority of the oocytes were collected in three follicular flushings. The fertilization rate for oocytes collected by the transabdominal method was significantly higher than that for those collected by the transvaginal method in cases of tubal damage and endometriosis (81.1% vs. 65.6% per oocyte, p less than 0.01). There was no significant difference between the signs of complications seen with the two methods. Six successful pregnancies were obtained by IVF-ET in our hospital (4 cases by the transabdominal method, and 2 cases by the transvaginal method). Two of these cases have already delivered full term healthy male infants. In conclusion, these results indicate that ultrasonic oocyte collection has been established as the most effective method for IVF-ET by means of either the transabdominal or the transvaginal methods.     

Detection of a uteroglobin-like phospholipase A2 inhibitory protein in the circulation of rabbits

Uteroglobin (UG) or blastokinin is a steroid-dependent low molecular weight secretory protein in the rabbit. This protein has many immunomodulatory properties. Recently, UG has been reported to be a potent phospholipase A2 (E.C. 3.1.1.4) inhibitor and this property may explain, at least in part, the immunomodulatory/antiinflammatory effects of this protein. Although UG has been detected in many reproductive and non-reproductive tissues of the rabbit it has not been reported in the circulation of this animal. Here, we present biochemical and immunochemical evidence for the presence of a low molecular weight circulating protein with progesterone binding and phospholipase A2 inhibitory properties similar to rabbit uterine UG. The major organs which contribute UG-like protein in circulation seem to be the tracheobronchial tree and to a lesser extent the uterus. The concentration of this protein is much higher in the vicinity of these organs as compared to peripheral circulation. Phospholipase A2 (PLA2)-catalyzed reaction is the major pathway of arachidonic acid production from cell membrane phospholipids. Arachidonic acid participates in the stimulation of guanylate cyclase, adenylate cyclase, protein kinase C and release of calcium from intracellular stores. These processes are thought to be involved in cellular signal transduction. Arachidonic acid is also essential for eicosanoid synthesis and many eicosanoids (e.g. prostaglandins, leukotrienes, etc.) are proinflammatory. Thus, the UG-like protein by inhibiting PLA2 may play a vital role in the regulation of cellular signal transduction, control of inflammation and platelet aggregation.     

Pancreatic pleural effusion with a pancreaticopleural fistula diagnosed by magnetic resonance cholangiopancreatography and cured by somatostatin analogue treatment

A 69-year-old man with chronic alcoholic pancreatitis developed a left-sided massive pleural effusion. Magnetic resonance cholangiopancreatography clearly demonstrated the pancreatic cyst and the fistula connecting the cyst with the left pleural cavity, resulting in the diagnosis of pancreatic pleural effusion with a pancreaticopleural fistula. Conservative somatostatin analogue treatment completely eradicated the pancreatic pleural effusion and closed the pancreaticopleural fistula.     

Effects of diabetes on nitric oxide-mediated relaxations in male rat corpus cavernosum smooth muscle

INTRODUCTION: We evaluated the effects of diabetes on nitric oxide-mediated relaxations and nitric oxide synthase activity in male rat corpus cavernosum smooth muscles. METHODS: Eight-week-old male rats were assigned to three groups: control (injected with the vehicle), DM (diabetes mellitus, induced by injection with 65 mg/kg streptozotocin), and TES (testosterone, testosterone supplemented after induction of diabetes). After 8 weeks, corpus cavernosum smooth muscle strips were mounted in an organ bath for isometric tension recordings. Electrical field stimulation (EFS, 2-ms pulse duration, 0.3-20 Hz and 3 s train) was applied to the strips precontracted with 30 microM phenylephrine. The microdialysis probe was inserted into the strip, and Krebs-Henseleit solution was perfused into the probe. The dialysate during EFS was collected, and the amount of NO(-)(2)/NO(-)(3) (NOx) released in the dialysate was measured by the Greiss method. Sodium nitroprusside (0.1 nM to 10 mM) and carbachol (1 nM to 10 mM) were cumulatively added to the strips precontracted with 30 microM phenylephrine. RESULTS: EFS caused frequency-dependent relaxations and NOx releases of the strips. Pretreatment with N(omega)-nitro-L-arginine (100 microM) and tetrodotoxin (1 microM) completely inhibited the relaxations and NOx releases. The maximum relaxation was significantly greater in the DM group than in the control or TES group. The release of NOx was significantly greater in the DM group than in the control or TES group. Sodium nitroprusside, the endothelium-independent vasodilator, relaxed the tissues in all three groups. There were no significant differences among control, DM and TES groups in the maximum relaxation to sodium nitroprusside. CONCLUSION: The present data suggest that diabetes enhances nitric oxide synthase activity and nitric oxide-mediated relaxations in the male rat corpus cavernosum by the reduced testosterone level in the diabetic animals.     

Venous thromboembolic diseases associated with uterine myomas diagnosed before hysterectomy: a report of two cases

Large uterine myomas (compressed veins in the pelvis), and the resulting impaired blood flow have been associated with deep vein thrombosis and pulmonary embolism. Careful detection of the preoperatively formed thrombi and strict perioperative management, such as in the following cases we report, may reduce lethal pulmonary embolism and may positively affect patient prognosis.     

Leiomyosarcoma of the larynx: emergency tracheostomy

Leiomyosarcoma of the larynx is extremely rare. Histological diagnosis for excluding other tumours remains extremely difficult. A rare case of leiomyosarcoma of the larynx, treated by surgery and radiotherapy, is reported. We discuss the clinical presentation, diagnosis, and treatment of leiomysarcoma with a review of the literature.