The colchicine derivative CT20126 shows a novel microtubule-modulating activity with apoptosis

New colchicine analogs have been synthesized with the aim of developing stronger potential anticancer activities. Among the analogs, CT20126 has been previously reported to show immunosuppressive activities. Here, we report that CT20126 also shows potential anticancer effects via an unusual mechanism: the modulation of microtubule integrity and cell cycle arrest at the G2/M phase before apoptosis. When we treated COS-7 cells with CT20126 (5 muM), the normal thread-like microtubules were disrupted into tubulin dimers within 10 min and thereafter repolymerized into short, thick filaments. In contrast, cells treated with the same concentration of colchicine exhibited microtubule depolymerization after 20 min and never underwent repolymerization. Furthermore, optical density (OD) analysis (350 nm) with purified tubulin showed that CT20126 had a higher repolymerizing activity than that of Taxol, a potent microtubule-polymerizing agent. These results suggest that the effects of CT20126 on microtubule integrity differ from those of colchicine: the analog first destabilizes microtubules and then stabilizes the disrupted tubulins into short, thick polymers. Furthermore, CT20126 induced a greater level of apoptotic activity in Jurkat T cells than colchicine (assessed by G2/M arrest, caspase-3 activation and cell sorting). At 20 nM, CT20126 induced 47% apoptosis among Jurkat T cells, whereas colchicine induced only 33% apoptosis. Our results suggest that the colchicine analog CT20126 can potently induce apoptosis by disrupting microtubule integrity in a manner that differs from that of colchicine or Taxol.

Phosphatidylinositol phosphates directly bind to neurofilament light chain (NF-L) for the regulation of NF-L self assembly

Phosphatidylinositol phosphates (PtdInsPs) are ubiquitous membrane phospholipids that play diverse roles in cell growth and differentiation. To clarify the regulation mechanism acting on neurofilament light chain (NF-L) self assembly, we examined the effects of various PtdInsPs on this process. We found that PtdInsPs, including PI(4,5)P2, directly bind to the positively charged Arg54 of murine NF-L, and this binding promotes NF-L self assembly in vitro. Mutant NF-L (R53A/R54A) proteins lacking binding affinity to PtdInsPs did not have the same effect, but the mutant NF-L proteins showed greater self assembly than the wild-type in the absence of any PtdInsP. These results collectively suggest that Arg54 plays a pivotal role in NF-L self assembly by binding with PtdInsPs.

A double point mutation in PCL-gamma1 (Y509A/F510A) enhances Y783 phosphorylation and inositol phospholipid-hydrolyzing activity upon EGF stimulation

Growth factor stimulation induces Y783 phosphorylation of phosphoinositide-specific PLC-gamma1, and the subsequent activation of this enzyme in a cellular signaling cascade. Previously, we showed that a double point mutation, Y509A/F510A, of PLC-gamma1, abolished interactions with translational elongation factor 1-alpha. Here, we report that the Y509A/F510A mutant PLC-gamma1 displayed extremely high levels of Y783 phosphorylation and enhanced catalytic activity, compared to wild-type PLC-gamma1, upon treatment of COS7 cells with EGF. In quiescent COS7 cells, the Y509A/F510A mutant PLC-gamma1 exhibited a constitutive hydrolytic activity, whereas the wild-type counterpart displayed a basal level of activity. Upon treatment of COS7 cells with EGF, the Y783F mutation in Y509A/F510A PLC-gamma1 (Y509A/F510A/Y783F triple mutant) cells also led to an enhanced catalytic activity, whereas Y783F mutation alone displayed a basal level of activity. Our results collectively suggest that the Y509A/F510A mutant is more susceptible to receptor tyrosine kinase-induced Y783 phosphorylation than is wild-type PLC-gamma1, but no longer requires Y783 phosphorylation step for the Y509A/F510A mutant PLC-gamma1 activation in vivo.

The Feasibility and Safety of Endoscopic Submucosal Dissection for Gastric Neoplasm in Elderly Korean Patients / 대한소화기내시경학회지

BACKGROUND/AIMS: Elderly patients often have high operative risk due to their comorbid diseases, and the feasibility of performing endoscopic submucosal dissection (ESD) for such patients should be investigated. The aim of this study is to evaluate the efficacy and safety of performing ESD in elderly patients. METHODS: From 2005 to 2007, 269 patients with gastric neoplasm were treated by ESD in our hospital. These patients were divided into the elderly patients who were 65 years of age or older and the younger patients. The number of enrolled elderly patients was 123. The en bloc complete resection rate and the complications were assessed and compared with those of the younger patients. RESULTS: The average age of the old age group of patients was 71.1. Of these patients, 53.7% had comorbid diseases and 51.2% revealed adenocarcinoma. The en bloc plus complete resection rate was 85.4%. Perforation during ESD occurred in 4.1% of the patients, and this was immediately closed with endoclips and then it was managed by conservative medical treatment. Bleeding occurred in 17.9% and there were no patients with severe bleeding. The en bloc plus complete resection rate and the complication rate for the elderly patients were not significantly different from those of the younger patients. CONCLUSIONS: The present study shows that ESD could be a safe and reliable treatment for gastric neoplasms in elderly patients.

Pleckstrin homology domain of phospholipase C-gamma1 directly binds to 68-kDa neurofilament light chain

Phosphoinositide-specific phospholipase C-gamma1 (PLC-gamma1) has two pleckstrin homology (PH) domains: an amino-terminal domain (PH1) and a split PH domain (PH2). Here, we show that overlay assay of bovine brain tubulin pool with glutathione-S-transferase (GST)-PLC-gamma1 PH domain fusion proteins, followed by matrix-assisted laser-desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), identified 68-kDa neurofilament light chain (NF-L) as a binding protein of amino-terminal PH domain of PLC-gamma1. NF-L is known as a component of neuronal intermediate filaments, which are responsible for supporting the structure of myelinated axons in neuron. PLC-gamma1 and NF-L colocalized in the neurite in PC12 cells upon nerve growth factor stimulation. In vitro binding assay and immunoprecipitation analysis also showed a specific interaction of both proteins in differentiated PC12 cells. The phosphatidylinositol 4, 5-bisphosphate [PI(4,5)P2] hydrolyzing activity of PLC-gamma1 was slightly decreased in the presence of purified NF-L in vitro, suggesting that NF-L inhibits PLC-gamma1. Our results suggest that PLC-gamma1-associated NF-L sequesters the phospholipid from the PH domain of PLC-gamma1.

The association of elevated alanine aminotransferase activity with obesity in health screenig subjects / 대한내과학회지

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has recently been recognized to be one of the leading causes of chronic liver disease. Obesity and type 2 diabetes are associated strongly with NAFLD. Although often used to detect liver disease, sometimes the cause of elevated Alanine Transaminase (ALT) activity was unclear. In the absence of other causes, the author examined whether BMI and metabolic markers of NAFLD can explain the cause of abnormal ALT in Korean. METHODS: From April 2002 to November 2003, 9997 persons visited health promotion center of Kyungpook National University Hospital and took health screening. After excluding persons with excessive alcohol consumption, abnormal gamma-GTP, hepatitis B, hepatitis C, 8379 persons were included in this study. All patients underwent anthropometric measures, blood chemistry analysis and abdominal ultrasonographic exam. RESULTS: Elevated ALT levels were found in 10% (835 persons) of the all subjects. In univariate analysis, factors associated with elevated ALT levels (por=23 kg/m2) was 79% in abnormal ALT group. In multivariate logistic regression study, total cholesterol and blood pressure were eleminated but sex, BMI, triglyceride level, ultrasonographic fatty change were strongly associated with elevated ALT level (p<0.01). CONCLUSION: In this study, unexplained ALT elevation was strongly associated with obesity, adiposity and other features of metabolic syndrome, and thus may represent nonalcoholic fatty liver disease. However, more research is needed for the definite clinical determinants of nonalcoholic fatty liver disease in Korean.

Phage Typing of Staphylococcus intermedius Isolated from Canine Clinical Specimens

Bacteriophages were induced from staphylococcus intermedius isolates from dogs and used for a phage typing. Mitomycin C induction was performed on 60 strains of S. intermedius and all phages were reacted with the strains. Twenty-eight strains (46.7%) were found to be lysogenic. Based on host ranges, eight phages were selected. By using the eight phages, 129 strains isolated from canine clinical specimens were subjected to the phage typing at the routine test dilution (RTD) and 100xRTD. Typability of the phage set was 78.3%, yielding 40 phage patterns. The phage set was considered useful for differentiating S. intermedius strains isolated from dogs. None of 50 strains of S. aureus, 2 (3.6%) of 56 S. simulance strains, 13 (24.5%) of 53 S. chromogenes strains and 46 (28.1%) of 164 S. hyicus strains were typable by the phages at 100xRTD.

A Case of Endosulfan Intoxication Occurring in Groups

Endosulfan is an agricultural chemical of organic chlorine, is toxic in both the central nervous system and the cardiovascular system, and causes respiratory system disorder and deaths by status epilepticus, respiratory distress, and so on. The use of this agricultural chemical of organic chlorine is limited by its toxicity. However, it is still used as a common insecticide, so it is readily to available. Four elderly people were admitted with depression of consciousness and convulsions after eating pan-fried food. During their treatment, the patients were diagnosed with endosulfan intoxication, completely by accident. We are reporting these cases of endosulfan intoxication that showed variable clinical findings from mild sequelae to death.

Sedative Effect of Etomidate and Fentanyl by the Combinational Administration During Closed Thoracostomy

PURPOSE: As a sedative hypnotic agent, etomidate has a little side effect like respiratory depression and has an excellent pharmacokinetics and hemodynamics. The objective of this study is comparison of etomidate effect in the two groups, only lidocaine injection group and combinational administration group, during closed thoracostomy in the emergency department. METHODS: The patients with respiratory problems, which needed a closed thoracostomy, from March 1, 2003 to February 29, 2004 were enrolled in this prospective study. Thus, we were enrolled 68 patients. etomidate were used for 34 patients and only lidocaine local injection was used for 34 patients. Patients of combinational administration were randomized to receive intravenous boluses of etomidate (0.2 mg/kg) prior to fentanyl (1.0 ug/kg) during PSA (procedural sedation anesthesia). We recorded pre-administration and interval of 5 minute, 10 minute, 15 minute and transcutaneous oxygen saturation, heart rate, respiratory rate, blood pressure, degree of sedation, satisfaction of sedation, and side effects after administration. RESULTS: Of all combinational administration group, significant hemodynamic, as hypotension or bradycardia etc. and respiratory depression, as apnea or tachypnea etc. were absent. With comparison of two groups, significant clinical problems and statistics were not different and degree of sedation was fast and impaired conscious was effective in the combinational administration group. CONCLUSION: We conclude combinational administration with etomidate and fentanyl during procedural sedation is safty and excellent effectiveness. Therefore we recommened the use of etomidate for emergency procedural sedation in emergency department.

Evaluation of the Effect Factor on Replantation and Revascularization of an Amputated Digit

PURPOSE: To find the factors influencing the immediate and late outcome of replantation and revascularization of the digits, we carried out a prospective study from 1998 to 1999 with at least a 1-year followup. Traumatic total and subtotal amputations with inadequate circulation of the digits distal to the metacarpal head were included in the study. METHODS: This study was carried out as a prospective study from 1998 to 1999 with at least a 1- year followup. The relationship between age, sex, extent of injury, type of injury, ischemic time, regular smoking, level of injury, and survival rate were analyzed. There were 234 patients with 155 males (254 digits) and 79 females (129 digits). RESULTS: Successful operation was found in 203 patients (86.3%), 314 digits (82%). Although male patients seemed to have poorer survival rates than female, it should be noted that male patients had more severe injuries than female patients. All patients who were regular cigarette smokers were males. Cigarette smoking has been shown to cause cutaneous vasoconstriction, decrease the digital blood flow, and impair the wound healing. These two reasons might explain the lower survival rate in males than in females. Type of injury significantly affected the survival rate. The survival rate was very low in extensive crushed amputation (11.1% survival rate), followed by degloving (21.1% survival rate) and avulsion (64.7% survival rate) amputation. The level of injury also seemed to determine the survival rate as injury at Zone I (65% survival rate) resulted in a poor survival rate compared to the injury at Zone II, III, or IV (92%, 97.6%, or 90.9% survival rate). Ischemic time longer than 8 hours might lessen the survival rate. CONCLUSION: All patients who had successful replantation and revascularization were satisfied with the results even though they had rather poor hand movement. In single digital replantation, no patients needed reamputation, but all preferred to have their finger replanted than udergo a primary amputation. All could accommodate and adapt their injured digits to their work.

Diagnostic Accuracy of Ultrasonography-guided Needle Biopsy of the Liver as determined by Postsurgical Sampling / 대한간학회지

BACKGROUND/AIMS: It is questionable whether the needle biopsy of the liver can represent the whole pathology of the liver. This study evaluates the diagnostic accuracy of ultrasonography-guided needle biopsy of the liver as determined by surgically resected liver. METHOD: The histopathologic findings of preoperative ultrasonography-guided needle biopsy for confirming the background liver disease and surgically resected liver were compared in the 40 patients with primary hepatocellular carcinoma. RESULTS: 1) Of the 40 cases, 30 (75.0%) cases showed the same histopathological diagnosis between the two methods. Their histopathological results were: 20 cases of cirhosis, 6 cases of chronic hepatitis and 4 cases of normal tissue. 2) There was a direct proportion between histologic concordance, the number of portal areas, and the size of the needle biopsy specimen. The histologic concordance rate was 79.2% in the cases with 4 portal areas in their biopsy sample and 100% in the cases with more than 5 areas. 3) Of the 10 cases in which diagnostic discrepancy was found between the two methods, 8 cases of chronic hepatitis and 1 case of normal tissue, all diagnosed by needle biopsy, proved to be cirrhosis by surgically resected liver. One case of normal tissue proved to be chronic hepatitis. The causes of diagnostic error were fragmentations of tissue and inadequate specimens. CONCLUSION: The diagnostic accuracy of the ultrasonography-guided needle biopsy of the liver was 75.0% in our study. To lessen the diagnostic error, at least 4 or more portal areas should be contained in the biopsy sample and the fragmentation of tissue should be minimized.