Intrathecal midazolam increases the analgesic effects of spinal blockade with bupivacaine in patients undergoing haemorrhoidectomy

In the present double-blind study we aimed to evaluate the postoperative analgesic effects of intrathecal midazolam with bupivacaine following haemorrhoidectomy. Forty-five patients were randomly allocated to one of three groups: the control group received 1 ml of 0.5% heavy bupivacaine plus 0.2 ml of 0.9% saline intrathecally, group BM1 received 1 ml of 0.5% bupivacaine plus 0.2 ml of 0.5% preservative-free midazolam and group BM2 received 1 ml of 0.5% bupivacaine plus 0.4 ml of 0.5% midazolam. Time to first analgesia was significantly greater in the midazolam groups than in the placebo and significantly less in the BM1 group than in the BM2 group.

Y chromosome microdeletions in idiopathic azoospermia and non-mosaic type of Klinefelter syndrome

The objective of this study was to elucidate the cause of the spermatogenic defect in idiopathic azoospermia and non-mosaic type of Klinefelter syndrome. Genomic DNAs from 9 cases of Korean idiopathic azoospermia and 6 of Korean non-mosaic type of Klinefelter syndrome were used for the detection of Y chromosome microdeletions by polymerase chain reaction using 60 primers. Microdeletions of the Y chromosome were found in 1 of 9 (11.1%) patients with idiopathic azoospermia, whereas none was deleted in non-mosaic type of Klinefelter syndrome. This result suggests that Y chromosome microdeletions could be one of the etiologic factors in idiopathic azoospermia.

A small-scale survey on the status of intestinal parasite infections in rural villages in Nepal

The status of intestinal parasite infections was investigated in two rural villages (Chitrasar, Jerona) in Chitwan District, Nepal in 1999. Stool examination was performed with a total of 300 specimens from schoolchildren by formalin-ether sedimentation technique. The prevalence rate of intestinal parasite infections in the surveyed areas was 44.0%. The prevalence rate in Jerona was slightly higher than that in Chitrasar. The prevalence rate of intestinal parasite infections in female was slightly higher than that in male without statistically significant difference. Entamoeba coli was the most commonly found protozoan parasite (21.0%) followed by Giardia lamblia (13.7%) and others (5.3%). Hookworm was the most prevalent intestinal helminth (13.0%) followed by Trichuris trichiura (3.0%) and others (5.0%). Forty-three specimens (14.3%) showed mixed infections. It is necessary to implement large-scale treatment with anthelminthics, health education and sanitary improvement for intestinal parasite control in the surveyed areas.

Protein kinase C inhibitors attenuate protective effect of high glucose against hypoxic injury in H9c2 cardiac cells

In this study, we demonstrated that PKC inhibitors significantly attenuated the cardioprotective effect produced by high-glucose (22 mM) treatment for 48 h against hypoxic injury in H9c2 cardiac cells. PKC activators mimicked the cardioprotective effect of high glucose. These results suggest a possible role of PKC activation in high-glucose--induced protection.

Effects of digoxin on acute, atrial fibrillation-induced changes in atrial refractoriness

BACKGROUND

Atrial fibrillation (AF) shortens the atrial effective refractory period (ERP) and predisposes to further episodes of AF. The acute changes in atrial refractoriness may be related to tachycardia-induced intracellular calcium overload. The purpose of this study was to determine whether digoxin, which increases intracellular calcium, potentiates the acute effects of AF on atrial refractoriness in humans.

METHODS AND RESULTS

In 38 healthy adults, atrial ERP was measured at basic drive cycle lengths (BDCLs) of 350 and 500 ms after autonomic blockade. Nineteen patients had been treated with digoxin for 2 weeks. After a several-minute episode of AF, atrial ERP was measured serially at alternating BDCLs. Compared with pre-AF ERPs, the first post-AF ERPs were significantly shorter in both the digoxin and the control groups (P:<0.001). The post-AF ERP at a BDCL of 350 ms shortened to a greater degree in the digoxin group (37+/-16 ms) than in the control group (20+/-13 ms, P:<0.001); similar changes occurred at a BDCL of 500 ms. During post-AF determinations of the atrial ERP, secondary AF episodes occurred significantly more often in the digoxin group (32% versus 16%; P:<0. 04).

CONCLUSIONS

After a brief episode of AF, digoxin augments the shortening that occurs in atrial refractoriness and predisposes to the reinduction of AF. These effects occur in the setting of autonomic blockade and therefore are more likely to be due to the effects of digoxin on intracellular calcium than to its vagotonic effects.

Tumor vessel: a valuable cholangioscopic clue of malignant biliary stricture

BACKGROUND

An irregularly dilated and tortuous vessel, the so-called tumor vessel, is considered to be one of the cholangioscopic features that suggest biliary malignancy. This is a prospective analysis of the presence of a tumor vessel as a finding that discriminates between benign and malignant biliary strictures.

METHODS

From August 1997 to August 1998, a total of 63 patients with biliary strictures diagnosed with endoscopic retrograde cholangiography or percutaneous transhepatic cholangiography obtained during percutaneous transhepatic biliary drainage tube placement were included in this study. Strictures were characterized as benign or malignant based on the observation of tumor vessels. The results were compared with those of percutaneous transhepatic cholangiography-guided biopsy and final diagnosis.

RESULTS

Forty-one patients were confirmed to have malignant strictures and 22 had benign biliary strictures. Cancer was confirmed by histopathologic evaluation of biopsies in 33 of 41 patients with malignancy (80.4%). Tumor vessel was seen in 25 of 41 patients with malignancy (61%). No patients with benign stricture had tumor vessels. Of the 8 patients with negative percutaneous transhepatic cholangioscopy-guided biopsies but with a final diagnosis of malignancy, 6 had tumor vessels. Combining the observation of tumor vessel and percutaneous transhepatic cholangiography-guided biopsy resulted in a diagnosis of malignancy in 39 of 41 patients (96%) and significantly increased the rate of preoperative diagnosis when compared with percutaneous transhepatic cholangiography-guided biopsy or presence of tumor vessel alone (p<0.05).

CONCLUSION

The presence of tumor vessel may be a valuable cholangioscopic finding that indicates the presence of a malignant biliary stricture. The combination of tumor vessel observation and percutaneous transhepatic cholangiography-guided biopsy may improve the preoperative diagnosis of malignancy.

Radiation exposure for human Mars exploration

One major obstacle to human space exploration is the possible limitations imposed by the adverse effects of long-term exposure to the space environment. Even before human space flight began, the potentially brief exposure of astronauts to the very intense random solar energetic particle events was of great concern. A new challenge appears in deep-space exploration from exposure to the low-intensity heavy-ion flux of the galactic cosmic rays since the missions are of long duration, and accumulated exposures can be high. Because cancer induction rates increase behind low to moderate thicknesses of aluminum shielding, according to available biological data on mammalian exposures to galactic cosmic ray-like ions, aluminum shield requirements for a Mars mission may be prohibitively expensive in terms of mission launch costs. Alternative materials for vehicle construction are under investigation to provide lightweight habitat structures with enhanced shielding properties. In the present paper, updated estimates for astronaut exposures on a Mars mission are presented and shielding properties of alternative materials are compared with aluminum.

Safety and usefulness of percutaneous transhepatic cholecystoscopy examination in high-risk surgical patients with acute cholecystitis

BACKGROUND

The aim of the present study was to evaluate the diagnostic and therapeutic usefulness of percutaneous transhepatic cholecystoscopy in high-risk surgical patients with acute cholecystitis.

METHODS

Between January 1992 and June 1998, there were 33 consecutive patients who underwent percutaneous transhepatic cholecystostomy and subsequent percutaneous transhepatic cholecystoscopy for the management of acute cholecystitis.

RESULTS

Percutaneous transhepatic cholecystostomy and subsequent percutaneous transhepatic cholecystoscopy were successfully accomplished in all 33 patients. During percutaneous transhepatic cholecystoscopy, minor complications (2 episodes of minor bleeding during electrohydraulic lithotripsy, 2 of tube dislodgement, and 1 of bile leakage to peritoneum) occurred in 5 patients. Percutaneous transhepatic cholecystoscopy revealed gallstones in 26 cases, sludge ball in 3, gallbladder carcinoma in 3, and 1 case of clonorchiasis related with acute cholecystitis. The 3 gallbladder cancers which were not identified radiologically were found incidentally during percutaneous transhepatic cholecystoscopy. For the 26 patients with gallstones, percutaneous transhepatic cholecystoscopy and concomitant stone removal were successful in 1 to 4 consecutive sessions (mean 2.2 sessions). Gallstones recurred in 3 of 22 patients (14%) during the mean follow-up period of 27 months. All of them remain asymptomatic.

CONCLUSION

Percutaneous transhepatic cholecystostomy may be justified in the management of acute cholecystitis in selected patients with high surgical risk.

Cholangioscopic findings in bile duct tumors

BACKGROUND

Cholangioscopy has been used in the treatment of bile duct stones and the diagnosis of various bile duct tumors. However, the cholangioscopic characteristics of the various types of bile duct tumors have not been clearly described. We analyzed the results of cholangioscopic examinations and classified the findings according to tumor histology.

METHODS

Cholangioscopic findings from 111 patients with benign or malignant bile duct tumors were reviewed. The mucosal changes, the presence of neovascularization, and the patterns of luminal narrowing were analyzed and compared with the histologic diagnosis.

RESULTS

Bile duct adenocarcinoma can be classified into 3 different types according to the cholangioscopic findings: nodular, papillary, and infiltrative. Bile duct adenoma, hepatocellular carcinoma and other types of bile duct cancer such as mucin-hypersecreting cholangiocarcinoma, biliary cystadenocarcinoma, and squamous cell carcinoma also presented unique cholangioscopic characteristics.

CONCLUSIONS

Bile duct tumors exhibit characteristic cholangioscopic findings and cholangioscopy seems to be useful for differential diagnosis.

Cost analysis of transthoracic cardioversion of atrial fibrillation with and without ibutilide pretreatment

BACKGROUND

Ibutilide may result in chemical cardioversion of atrial fibrillation and facilitates transthoracic cardioversion by lowering the defibrillation energy requirement. Whether routine pretreatment with ibutilide increases or decreases the cost of cardioversion is unknown. The purpose of this study was to compare the cost of outpatient transthoracic cardioversion of atrial fibrillation with and without ibutilide pretreatment.

METHODS

Using a model based on published literature and hospital accounting information, a hypothetical group of 100 patients with atrial fibrillation and a left ventricular ejection fraction >0.30 underwent 2 strategies of outpatient cardioversion: transthoracic cardioversion with and without routine pretreatment with 1 mg ibutilide, and with and without involvement of an anesthesiologist for sedation. If transthoracic cardioversion was unsuccessful in patients who did not receive ibutilide, transthoracic cardioversion was repeated after administration of ibutilide.

RESULTS

If an anesthesiologist was involved, transthoracic cardioversion with ibutilide was associated with incremental cost-savings as the efficacy of ibutilide alone in restoring sinus rhythm increased above the critical values of 20%, 27%, and 35% when the efficacy of transthoracic cardioversion alone was 60%, 80%, and 100%, respectively. In the absence of an anesthesiologist, routine pretreatment with ibutilide increased the cost of cardioversion at all success rates of transthoracic cardioversion.

CONCLUSIONS

In the presence of an anesthesiologist, whether or not routine pretreatment with ibutilide lowers the mean cost of cardioversion is determined by the success rates of chemical cardioversion with ibutilide and transthoracic cardioversion. In the absence of an anesthesiologist, ibutilide pretreatment increases the cost of cardioversion.

A new strategy to predict the neoplastic polyps of the gallbladder based on a scoring system using EUS

BACKGROUND

A new method to predict neoplastic polyps of the gallbladder using a scoring system based on five endoscopic ultrasonography (EUS) variables is presented.

METHODS

EUS data from patients with gallbladder polyps who were to undergo cholecystectomy were used for the construction of an EUS scoring system in polyps between 5 and 15 mm in diameter (reference group). The EUS scoring system developed from those patients was applied to other patients (validation group).

RESULTS

In the reference group, size was the most significant predictor of neoplastic polyp. All polyps 5 mm or less in diameter were non-neoplastic and 94% of polyps of greater than 15 mm were neoplastic in the reference group. For polyps between 5 and 15 mm in diameter, the area under the receiver-operating characteristic curves (ROC) plots for the endoscopic scoring system was significantly greater than that under the ROC plots for polyp size alone (p < 0.01). In the validation group, the risk of neoplastic polyp was significantly higher for polyps with a score of 6 or greater compared with those with a score of less than 6 (p < 0.01).

CONCLUSIONS

Our data show that a score based on five EUS variables identifies those patients at risk of neoplasia when polyps are between 5 and 15 mm in diameter. (Gastrointest Endosc 2000;52:372-9).

Expression of matrix metalloproteinases and their inhibitors by rat NK cells: inhibition of their expression by genistein

In this study, we describe rat NK cell-derived MMPs including membrane-type MMPs (MT-MMPs) and tissue inhibitors of MMP (TIMPs). RT-PCR analysis from cDNA of rat A-NK cells revealed mRNA for MMP-2, MMP-9, MMP-7, MMP-10, MMP-11, MMP-13, MT1-MMP, MT2-MMP, TIMP-1, and TIMP-2. The RNK-16 cells expressed mRNA for MMP-7, MMP-10, MMP-11, MT1-MMP, MT2-MMP, TIMP-1, and TIMP-2, in addition to MMP-3 and MMP-13. Western blot analysis confirmed proteins for MT1-MMP and MT2-MMP in RNK-16 cells. TIMP-1 in rat A-NK cells was present at molecular mass of 34-kDa protein which may represent a highly glycosylated form. Genistein, a natural isoflavone found in soybeans, inhibited proliferation of RNK-16 cells in dosage dependent manner. In addition, it down-regulated the expression of MMP-13, MT1-MMP, TIMP-1 and TIMP-2. Moreover, genistein greatly impaired the ability of RNK-16 cells to invade through a model basement membrane. This effect might be mediated by the observed down-regulation of MMP-13 and MT1-MMP.

Anaerobic bacteria and intrahepatic stones: detections of Clostridium sp. and Bacteroides fragilis

OBJECTIVE

To detect anaerobic bacteria Clostridium sp. and Bacteroides fragilis in intrahepatic stones by molecular genetic method.

METHODS

DNA was extracted from 59 stone samples and subjected to polymerase chain reaction (PCR) amplification targeting the 16S rRNA gene of Clostridium sp. and the glutamine synthetase gene of Bacteroides fragilis. Single-strand conformational polymorphism (SSCP) analysis was performed to identify the Clostridium sp.

RESULTS

16S rRNA gene sequences for Clostridium sp. were identified in 49 stones (83%, 49/59). The two most common groups were detected in 19 (41%) and 17 (37%) of the 46 samples using SSPC analysis, and 25/59 (42%) stones were tested positive for Bacteroides fragilis.

CONCLUSIONS

Anaerobes such as Clostridium sp. and Bacteroides fragilis present in intrahepatic stones and may play a role in stone formation. PCR is a useful technique to detect fastidious pathogens, which are difficult to culture. SSCP of PCR products is a rapid method in differentiating bacterial species.

Effect of Fiber-Polymer Interactions on Fracture Toughness Behavior of Carbon Fiber-Reinforced Epoxy Matrix Composites

The effect of anodic oxidation on high-strength polyacrylonitrile-based carbon fibers has been studied in terms of fiber surface energetics and fracture toughness of the composites. According to contact angle measurements based on the wicking rate of a test liquid, anodic oxidation leads to an increase in surface free energy, mainly due to the increase of its specific (or polar) component. For the carbon-fiber-reinforced epoxy resin matrix system, a direct linear relationship is shown between the specific component and the critical stress intensity factor measured by the single edge notched beam fracture toughness test. From a surface-energetic point of view, the anodic treatment may be suitable for carbon fibers incorporated in a polar organic matrix, resulting in an increased specific component of the surface free energy. Good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices of the resulting composites. Copyright 2000 Academic Press.

Diagnostic value of tachycardia features and pacing maneuvers during paroxysmal supraventricular tachycardia

OBJECTIVES

The purpose of this prospective study was to quantitate the diagnostic value of several tachycardia features and pacing maneuvers in patients with paroxysmal supraventricular tachycardia (PSVT) in the electrophysiology laboratory.

BACKGROUND

No study has prospectively compared the value of multiple diagnostic tools in a large group of patients with PSVT.

METHODS

One hundred ninety-six consecutive patients who had 200 inducible sustained PSVTs during an electrophysiology procedure were included. The diagnostic values of four baseline electrophysiologic parameters, nine tachycardia features and five diagnostic pacing maneuvers were quantified.

RESULTS

The only tachycardia characteristic that was diagnostic of atrioventricular (AV) nodal reentry was a septal ventriculoatrial (VA) time of <70 ms, and no pacing maneuver was diagnostic for AV nodal reentry. An increase in the VA interval with the development of a bundle branch block was the only tachycardia characteristic that was diagnostic for orthodromic tachycardia, but it occurred in only 7% of all tachycardias. An atrial-atrial-ventricular response upon cessation of ventricular overdrive pacing was diagnostic of atrial tachycardia, and this maneuver could be applied to 78% of all tachycardias. Burst ventricular pacing excluded atrial tachycardia when the tachycardia terminated without depolarization of the atrium, but the result could be obtained only in 27% of patients.

CONCLUSIONS

This prospective study quantitates the diagnostic value of multiple observations and pacing maneuvers that are commonly used during PSVT in the electrophysiology laboratory. The findings demonstrate that diagnostic techniques rarely provide a diagnosis when used individually. Therefore, careful observations and multiple pacing maneuvers are often required for an accurate diagnosis during PSVT. The results of this study provide a useful reference with which new diagnostic techniques can be compared.

Detection of Helicobacter pylori DNA in human biliary tree and its association with hepatolithiasis

Recently, several authors have reported that Helicobacter pylori DNA has been found in human bile. The aim of this study is to investigate the presence of H. pylori in the biliary tree of Koreans, including the bile, biliary epithelium, and gallstones. This study analyzed intrahepatic bile, bile duct tissue, and gallstones from 43 patients with hepatobiliary disease (PTCS group), gallbladder bile and tissue from 23 patients with gallbladder disease (CCT group), and eight patients without hepatobiliary disease (control group). H. pylori was examined by PCR with two different primers. PCR was positive in 4/43 (9.3%) by 26 kDa protein antigen primer and in 5/43 (11.6%) by urease A gene primer in bile from the PTCS group. However, in intrahepatic duct tissue, PCR was positive in only one case. PCR of gallbladder bile, tissue, and intrahepatic duct stones was negative. Upon intrahepatic bile analysis, the pH was significantly lower in PCR-positive than in negative cases (P < 0.05). In conclusion, H. pylori DNA may be present in the bile when there are certain environmental changes, such as lowered pH; however, H. pylori does not colonize the bile duct epithelium. We could find no pathogenetic role for H. pylori in the formation of hepatolithiasis.

Effect of chronic amiodarone therapy on defibrillation energy requirements in humans

INTRODUCTION

The effect of oral amiodarone therapy on defibrillation energy requirements in patients with an implantable defibrillator has not been established.

METHODS AND RESULTS

Twenty-one consecutive patients with implantable biphasic waveform defibrillators underwent a step-down determination of the defibrillation energy requirement 211 +/- 12 days before and 73 +/- 22 days after initiation of amiodarone therapy (mean total dose 26.7 +/- 11.1 g). Serum amiodarone and desethylamiodarone concentrations were measured at the time of defibrillation energy requirement determination. The mean defibrillation energy requirement before amiodarone therapy was 9.9 +/- 4.6 J. After initiation of amiodarone therapy, the mean defibrillation energy requirement increased to 13.7 +/- 5.6 J (P = 0.004). A linear relationship between the amiodarone (P = 0.02, r = 0.6), desethylamiodarone (P = 0.02, r = 0.6), and combined amiodarone-desethylamiodarone concentrations (P = 0.01, r = 0.6) and the defibrillation energy requirement was noted. Stepwise regression analysis demonstrated that the combined amiodarone-desethylamiodarone concentration was the only independent predictor of increase in the defibrillation energy requirement.

CONCLUSION

Chronic oral amiodarone therapy increases the defibrillation energy requirement by approximately 62% in patients with an implantable defibrillator. The combined amiodarone-desethylamiodarone concentration is directly related to the increase in the defibrillation energy requirement.

Detection of Helicobacter pylori DNA in human biliary tree and its association with hepatolithiasis

Recently, several authors have reported that Helicobacter pylori DNA has been found in human bile. The aim of this study is to investigate the presence of H. pylori in the biliary tree of Koreans, including the bile, biliary epithelium, and gallstones. This study analyzed intrahepatic bile, bile duct tissue, and gallstones from 43 patients with hepatobiliary disease (PTCS group), gallbladder bile and tissue from 23 patients with gallbladder disease (CCT group), and eight patients without hepatobiliary disease (control group). H. pylori was examined by PCR with two different primers. PCR was positive in 4/43 (9.3%) by 26 kDa protein antigen primer and in 5/43 (11.6%) by urease A gene primer in bile from the PTCS group. However, in intrahepatic duct tissue, PCR was positive in only one case. PCR of gallbladder bile, tissue, and intrahepatic duct stones was negative. Upon intrahepatic bile analysis, the pH was significantly lower in PCR-positive than in negative cases (P < 0.05). In conclusion, H. pylori DNA may be present in the bile when there are certain environmental changes, such as lowered pH; however, H. pylori does not colonize the bile duct epithelium. We could find no pathogenetic role for H. pylori in the formation of hepatolithiasis.

2B4 stimulation of YT cells induces natural killer cell cytolytic function and invasiveness

2B4 is a surface molecule found on all human natural killer (NK) cells, a subset of CD8+ T cells, monocytes and basophils. It was originally identified on mouse NK cells and the subset of T cells that mediate non-major histocompatibility complex (MHC)-restricted killing. Recently,9 we have cloned the human homologue of 2B4 (h2B4) and found h2B4 to also mediate non-MHC-restricted cytotoxicity. In this study, we examine h2B4 in regulating various functions of NK cells using a human NK cell line YT, with monoclonal antibody (mAb) C1.7, an antibody that specifically recognizes h2B4. Ligation of surface 2B4 with mAb C1.7 increases YT's ability to destroy tumour cells. In the presence of mAb C1.7, the production of interferon-gamma (IFN-gamma) by YT cells is greatly enhanced. Engagement of surface 2B4 by mAb C1.7 downregulates the expression of h2B4 at the cell surface as well as the expression of h2B4 mRNA. Also, signalling through h2B4 causes the increased expression of matrix metalloproteinase-2, a member of the matrix degrading proteinase family. Thus, in addition to modulating cytolytic function and cytokine production of NK cells, activation through surface 2B4 may play a role in upregulating the machinery for degradation of extracellular matrices to promote invasion of the tumour by NK cells.

Phosphorylation of the rat vesicular acetylcholine transporter

Metabolic labeling of a mutant PC12 cell line, A123.7, expressing recombinant rat vesicular acetylcholine transporter (VAChT) with radiolabeled inorganic phosphate was used to demonstrate phosphorylation of the transporter on a serine residue. Mutational analysis was used to demonstrate that serine 480, which is located on the COOH-terminal cytoplasmic tail, is the sole phosphorylation site. Phosphorylation of serine 480 was attributable to the action of protein kinase C. Using a permanently dephosphorylated form of rat VAChT, S480A rVAChT, it was shown that this mutant displays the same kinetics for the transport of acetylcholine and the binding of the inhibitor vesamicol as does the wild type transporter. However, sucrose gradient density centrifugation showed that, unlike wild type VAChT, the S480A mutant did not localize to synaptic vesicles. These results suggest that phosphorylation of serine 480 of VAChT is involved in the trafficking of this transporter.