Cellular mechanism underlying leptin-induced anion secretion of rat epididymal epithelial cells.

BACKGROUND: A large number of studies have shown that leptin plays an important role in the regulation of fertility via the hypothalamus-pituitary-gonad axis. However, its peripheral function in epididymis was still elusive. OBJECTIVE: The purpose of this study was to determine the pro-secretion effect of leptin on the rat epididymal epithelium. MATERIALS AND METHODS: In the present study, real-time quantitative polymerase chain reaction, western blot, and immunohistochemical analysis were employed to detect the expression pattern of leptin receptors in rat epididymis. The pro-secretion effect of leptin on epididymal epithelial cells was measured by short-circuit current, and the prostaglandin E2 and cyclic adenosine monophosphate level was evaluated by enzyme-linked immunosorbent assay. RESULTS: We verified that the leptin receptor was located on the epididymal epithelium, with a relatively high expression level in corpus and cauda epididymis. Ussing chamber experiments showed that leptin stimulated a significant rise of the short-circuit current in rat epididymal epithelial cells, which could be abolished by the specific leptin receptor antagonist peptide Allo-aca, or by removing the ambient Cl- and HCO3 -. Furthermore, the leptin-stimulated short-circuit current response could be abrogated by blocking the apical cystic fibrosis transmembrane regulator or the basolateral Na+-K+-2Cl- cotransporter. Our pharmacological experiments manifested that interfering with the prostaglandin H synthase-2-prostaglandin E2-EP2/EP4-adenylate cyclase pathways could significantly blunt the cystic fibrosis transmembrane regulator-mediated anion secretion induced by leptin. The enzyme-linked immunosorbent assay demonstrated that leptin could induce a substantial increase in prostaglandin E2 release and cyclic adenosine monophosphate synthesis of primary cultured rat cauda epididymal epithelial cells. Our data also suggested that JAK2, ERK, and PI3K-dependent phosphorylation may be involved in the activation of prostaglandin H synthase-2 and the subsequent prostaglandin E2 production. CONCLUSIONS: The present study demonstrated the pro-secretion function of leptin in rat epididymal epithelium via the activation of cystic fibrosis transmembrane regulator and Na+-K+-2Cl- cotransporter, which was dependent on the paracrine/autocrine prostaglandin E2 stimulated EP2/EP4-adenylate cyclase pathways, and thus contributed to the formation of an appropriate microenvironment essential for sperm maturation.

Case report: 177Lu DOTA-TATE: a new scheme for the treatment of prostate neuroendocrine cancer.

Background: Most instances of small cell carcinoma originate from the lungs, while the gastrointestinal tract serves as a secondary site. Only a minuscule proportion of cases manifest within the urogenital system. Prostate small cell carcinoma (SCCP) represents an exceedingly uncommon pathological subtype within the realm of prostate cancer, displaying significant rarity in clinical settings. This scarcity has resulted in a paucity of adequate foundational and clinical research for SCCP treatment. While investigations have unveiled a certain therapeutic efficacy of radiotherapy and chemotherapy for SCCP, clinical practice has revealed suboptimal treatment outcomes. We hereby present a case report detailing the utilization of 177Lu-DOTA-TATE in the treatment of SCCP, aiming to investigate the therapeutic efficacy of 177Lu-DOTA-TATE for SCCP. Case presentation: A male patient in his 80s presented with elevated prostate-specific antigen (PSA) levels and underwent a biopsy that revealed prostate adenocarcinoma. The patient received CAB (bicalutamide + goserelin) therapy. One year later, disease progression was detected, and a second biopsy confirmed the presence of prostate small cell carcinoma. Following the diagnosis of prostate small cell carcinoma, the patient underwent two cycles of 177Lu-DOTA-TATE treatment. Subsequent to the treatment, the original lesions showed shrinkage, metastatic lesions disappeared, and there was significant improvement, approaching complete remission. Conclusion: SCCP exhibits a high degree of malignancy and aggressive invasiveness, currently lacking effective therapeutic modalities. The treatment course of this patient serves as compelling evidence for the efficacy of 177Lu-DOTA-TATE in managing SCCP, thereby opening new avenues for future SCCP treatments.

Clinical Significance and Potential Role of LSM4 Overexpression in Hepatocellular Carcinoma: An Integrated Analysis Based on Multiple Databases.

Background: Hepatocellular carcinoma (HCC) is a solid tumor with high recurrence rate and high mortality. It is crucial to discover available biomarkers to achieve early diagnosis and improve the prognosis. The effect of LSM4 in HCC still remains unrevealed. Our study is dedicated to exploring the expression of LSM4 in HCC, demonstrating its clinical significance and potential molecular mechanisms. Methods: Clinical information and LSM4 expression values of HCC were obtained from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Survival analysis and receiver operating characteristic (ROC) curve analysis were applied to evaluate the prognostic and diagnostic significance of LSM4. Calculating pooled standardized mean difference (SMD) and performing summary receiver operating characteristic (sROC) curve analysis to further determine its expression status and diagnostic significance. LSM4-related co-expressed genes (CEGs) were obtained and explored their clinical significance in HCC. LSM4-associated pathways were identified through Gene set enrichment analysis (GSEA). Results: Up-regulated LSM4 was detected in HCC tissues (SMD = 1.56, 95% CI: 1.29-1.84) and overexpressed LSM4 had excellent distinguishing ability (AUC = 0.91, 95% CI: 0.88-0.93). LSM4 was associated with clinical stage, tumor grade, and lymph node metastasis status (p < 0.05). Survival analysis showed that high LSM4 expression was related to poor overall survival (OS) of HCC patients. Cox regression analysis suggested that high LSM4 expression may be an independent risk factor for HCC. We obtained nine up-regulated CEGs of LSM4 in HCC tissues, and six CEGs had good prognostic and diagnostic significance. GSEA analysis showed that up-regulated LSM4 was closely related to the cell cycle, cell replication, focal adhesion, and several metabolism-associated pathways, including fatty acid metabolism. Conclusion: Overexpressed LSM4 may serve as a promising diagnostic and prognostic biomarker of HCC. Besides, LSM4 may play a synergistic effect with CEGs in promoting the growth and metastasis of HCC cells via regulating crucial pathways such as cell cycle, focal adhesion, and metabolism-associated pathways.

FAM225A promotes sorafenib resistance in hepatocarcinoma cells through modulating miR-130a-5p-CCNG1 interaction network.

Chemotherapy resistance is still a key hurdle in current hepatocellular carcinoma (HCC) treatment. Therefore, clarifying the molecular mechanisms contributing to this acquired resistance is urgent for the effective treatment of liver cancer. In this research, we observed that lncRNA FAM225A expression is dramatically upregulated not only in hepatocellular carcinoma tissues and cell lines but also in sorafenib-resistant HepG2/SOR cells. Moreover, FAM225A knockdown significantly weakened HepG2/SOR cells resistance to sorafenib treatment by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Similar results were obtained from the tumor xenograft model in mice. Further mechanistic researches revealed that the direct interaction between FAM225A and miR-130a-5p, while miR-130a-5p negatively modulated CCNG1 expression by targeting 3'UTR of CCNG1. MiR-130a-5p inhibition or CCNG1 overexpression could partially offset FAM225A knockdown-induced increased viability of HepG2/SOR cells in response to sorafenib challenge. Collectively, our findings provide evidence that FAM225A/miR-130a-5p/CCNG1 interaction network regulates the resistance of HCC cells to sorafenib treatment and could supply a possible strategy for restoring sorafenib sensitivity in HCC therapy.

Effects of erector spinae plane block on postoperative pain and side-effects in adult patients underwent surgery: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Recently, the effects of erector spinae plane block on postoperative pain have become increasingly controversial. This meta-analysis compared the effects of ESP block versus placebo on postoperative analgesia and side effects to determine whether the new technique is a reliable alternative for pain management. METHODS: PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang Database were searched for clinical studies investigating the analgesic effect of ESP block versus placebo. The primary outcomes included the visual analogue scale (VAS) at rest and during movement, as well as the postoperative morphine consumption in 24 h, and the secondary outcome was the rate of postoperative nausea and vomiting (PONV). The choice of using the fixed or random-effects model depended on whether the heterogeneity tested by I2 statistic was more than 50%. Seeking sources of heterogeneity and exploring the effect of clinical details on the final result were performed by subgroup analysis. Additionally, the test for stability of the pooled result was realized by sensitivity analysis. Finally, we evaluated the quality of the evidence for the outcomes. STATA 13.0 software was selected as the main analysis software in the meta-analysis. RESULTS: Eighteen randomized controlled trials (RCTs) comprising 1041 patients were reviewed. This meta-analysis showed that ESP block could significantly reduce patients' pain scores at 1 h, 6 h, 12 h, and 24 h after surgery at rest or during movement; 24-h postoperative morphine consumption; and the incidence of PONV. CONCLUSIONS: ESP block as a novel technique exhibited superior postoperative analgesic effects, reducing the postoperative complications in spinal, thoracic, and abdominal surgeries during the early postoperative period. However, as a new nerve block technique, numerous large-sized RCTs are needed for further research.

Nitric Oxide Inhibitory Sesquiterpenoids and Its Dimers from Artemisia freyniana.

Two new disesquiterpenoids (1 and 2) and 11 new (3-13) and 10 known (14-23) sesquiterpenoids were isolated from the whole plants of Artemisia freyniana. Their structures were elucidated by spectroscopic data analysis and comparison with published NMR data. The absolute configurations of the new isolates (1-13) were assigned based on single-crystal X-ray diffraction data and comparison of the experimental and calculated ECD data. The eremophilane derivatives 8 and 9 possess an unprecedented 2-isopropyl-3,7,7a-trimethyl-2,4,5,6,7,7a-hexahydro-1 H-indene scaffold, and a putative biosynthetic pathway for these compounds is proposed. Compounds 4, 5, and 9 exhibited inhibitory effects against LPS-stimulated nitric oxide (NO) production in RAW 264.7 macrophage cells with IC50 values of 10.8, 12.6, and 11.7 µM, respectively.

Characterization of a new sesquiterpene and antifungal activities of chemical constituents from Dryopteris fragrans (L.) Schott.

One new sesquiterpene and six known compounds were isolated from Dryopteris fragrans (L.) Schot. They were identified as 3-O-ß-D-glucopyranosylalbicanol- 11-O-ß-D-glucopyranoside (1), dihydroconiferylalcohol (2), (E)-3-(4-hydroxyphenyl)acrylic acid (3), esculetin (4), 5,7-dihydroxy-2-hydroxymethylchromone (5), eriodictyol (6) and isoorientin (7) by UV, MS, 1D-NMR and 2D-NMR spectroscopy. The antifungal activities of the seven isolated compounds were screened. Compounds 2, 3, 4 and 5 showed obvious activities against Microsporum canis and Epidermophyton floccosum.

Dermatomyositis associated with gallbladder carcinoma: A case report.

Patients with gallbladder carcinoma can present with a variety of paraneoplastic syndromes, including Cushing's syndrome, hypercalcemia, acanthosis nigricans, bullous pemphigoid, dermatomyositis and the sign of Leser-Trélat. Surgical resection of the primary tumor results in resolution of these paraneoplastic syndromes. We present a 67-year old female with facial and cervical erythema who was initially diagnosed with dermatomyositis. However, an abdominal computed tomography (CT) and positron emission tomography-CT scan was suspicious for gallbladder carcinoma with lymph node metastasis. After surgical resection, her dermatomyositis was resolved. This case demonstrates that dermatomyositis may be a manifestation of preexisting gallbladder carcinoma.

Correlation of inflammatory cells in adventitia and formation and extending of atherosclerotic lesions in coronary artery of apolipoprotein E gene knockout mice.

Accumulating evidence shows that adventitial inflammation contributes to the development of atherosclerotic lesions. The aim of this study was to investigate the relationship between atherosclerotic lesions in coronary artery (CA) and accumulation of inflammatory cells at local adventitia in apolipoprotein E gene knockout (apoE-/-) mice. Modified Movat's pentachrome staining, HE staining, immunohistochemistry and transmission electron microscopy were used to observe and to identify serial paraffin sections of aortic foot and inflammatory cells in CA adventitia of apoE-/- mice of 60 weeks old. There was always accumulation of inflammatory cells in the adventitia of CA with extending lesions from aortic orifice to CA trunks. The CA samples were divided into type I: infiltration of inflammatory cells in CA adventitia without lesions extending in the intima, type II: infiltration of inflammatory cells in CA adventitia with the top of extending lesions in the intima and type III: infiltration of inflammatory cells at CA adventitia with lesions covering all the face of intima. The three types of CA sample represent the different developmental processes of atherosclerotic lesions, respectively. No extending lesions were found in the CA trunks without inflammatory cells in adventitia. In type I samples, 60% of infiltrated inflammatory cells were macrophages 57% of infiltrated cells were neutrophils in type II samples; 67% of infiltrated cells were lymphocytes in type III samples. Our studies revealed that adventitial inflammation may be an early event in the development of atherosclerotic lesions. Different cell types predominate in different stages of CA adventitia. The neutrophils are closely related to the extending of atherosclerotic lesions.

CYP1B1 Leu432Val polymorphism and colorectal cancer risk among Caucasians: a meta-analysis.

Studies investigating the association between cytochrome P450 1B1 (CYP1B1) Leu432Val (432 C/G, rs1056836) polymorphism and colorectal cancer (CRC) risk report conflicting results. The aim of this study was to quantitatively summarize the evidence for such a relationship. Two investigators independently searched the Medline, Embase, China National Knowledge Infrastructure, and Chinese Biomedicine Databases. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) for CYP1B1 polymorphism and CRC were calculated in a fixed-effects model and a random-effects model when appropriate. The pooled ORs were performed for co-dominant model (GG vs. CC, GC vs. CC), dominant model (GG + GC vs. CC), and recessive model (GG vs. GC + CC). This meta-analysis included ten case-control studies, which included 8,466 CRC cases and 9,301 controls. Overall, the variant genotypes (GG and GC) of the 432 C/G were not associated with CRC risk when compared with the wild-type CC homozygote (GG vs. CC, OR = 1.01, 95% CI = 0.93-1.10; GC vs. CC, OR = 0.97, 95% CI = 0.90-1.04), without any between-study heterogeneity. Similarly, no associations were found in the dominant and recessive models (dominant model, OR = 0.98, 95% CI = 0.92-1.05; recessive model, OR = 1.03, 95% CI = 0.96-1.11). Limiting the analysis to the studies within Hardy-Weinberg equilibrium, the results were persistent and robust. When stratifying for country, matched control and source of controls, no evidence of significant association was observed in any subgroup. No publication bias was found in the present study. No association is found between the CYP1B1 Leu432Val polymorphism and risk of CRC among Caucasians.

Reversal of multidrug resistance by guggulsterone in drug-resistant MCF-7 cell lines.

BACKGROUND: Multidrug resistance (MDR) presents a serious problem in cancer chemotherapy. Our previous studies have shown that the MDR of K562/DOX cells could be reversed by guggulsterone through inhibiting the function and expression of P-glycoprotein. The purpose of this study was to investigate the reversal effect of guggulsterone on MDR in drug-resistant MCF-7 cells and the parental MCF-7 cells. METHODS: MTT cytotoxicity assays, flow cytometry, and Western blot analysis were performed to investigate the antiproliferative effects of the combination of anticancer drugs with guggulsterone, to study the reversal of drug resistance and to examine the inhibitory effects on MRP1 expression. RESULTS: The results showed that co-administration of guggulsterone (10 µM) resulted in a significant increase in chemosensitivity of MCF-7/DOX cells to doxorubicin, compared with doxorubicin treatment alone (p < 0.01). The fold reversal of 10 µM guggulsterone (11.48) was comparable to that of 10 µM verapamil (13.23). Rhodamine123 and doxorubicin accumulation in MCF-7/DOX cells was significantly enhanced after the incubation with guggulsterone (10 µM), compared with untreated MCF-7/DOX cells (p < 0.01). When doxorubicin (10 µM) was combined with guggulsterone (10 µM), the mean apoptotic population of MCF-7/DOX cells was 24.91%. It was increased by 6.15 times, compared with doxorubicin (10 µM) treatment alone. However, guggulsterone had little inhibitory effect on the expression of MRP1 proteins. CONCLUSION: Guggulsterone is a novel and potent MDR reversal agent with the potential to be an adjunctive agent for tumor chemotherapy.

[Expression of CAR in myocardial of viral myocarditis and dilated cardiomyopathy].

OBJECTIVE: In order to improve accuracy and reliability of forensic diagnosis of sudden cardiac death, pathogenesis and relationship between the viral myocarditis (VMC) and dilated cardiomyopathy (DCM) were investigated. METHODS: Improved immunohistochemical technique was used to detect the expression of the CAR in myocardium samples, including 22 deceased with VMC, 20 deceased with DCM and 16 control deceased. RESULTS: The brown staining on the cell membrane of myocardium showed positive result. There was a prominent CAR expression in VMC group and DCM group, which were statistically significant difference compared with control group (P < 0.05). CONCLUSION: The CAR expression showed significantly higher in VMC and DCM groups. The viral infection can result in myocardial necrosis and impaired cardiac functions. These abnormalities can trigger a cascade of events that contributed to the progress of VMC to DCM.

Reversal of P-glycoprotein-mediated multidrug resistance by guggulsterone in doxorubicin-resistant human myelogenous leukemia (K562/DOX) cells.

Multidrug resistance (MDR) has been a major problem in cancer chemotherapy. The development of P-glycoprotein inhibitors could be effective to reverse multidrug resistance. The aim of this study was to observe the effects of guggulsterone, the active component of gugulipid, on multidrug resistance in doxorubicin-resistant K562 cells (K562/DOX) and the parental K562 cells. Its cytotoxicity and reversal effects on multidrug resistance were assessed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Apoptosis percentage of cells was obtained from Annexin V/fluorescein isothiocyanate (FITC) and propridium iodide (PI) double staining. The effects of guggulsterone on P-glycoprotein activity were evaluated by measuring rhodamine 123 (Rh123)-associated mean fluorescence intensity and P-glycoprotein expression on the basis of the flow cytometric technology, respectively. The results showed that guggulsterone up to 100 microM had little cytotoxicity against K562/DOX cells. When combined with doxorubicin, it significantly promoted the sensitivity of K562/DOX cells toward doxorubicin through increasing intracellular accumulation of doxorubicin in a dose-dependent manner. Further study demonstrated that the inhibitory effect of guggulsterone on P-glycoprotein activity was the major cause of increased stagnation of doxorubicin inside K562/DOX cells, indicating that guggulsterone may effectively reverse multidrug resistance in K562/DOX cells via inhibiting expression and drug-transport function of P-glycoprotein.

Protection against hydrogen peroxide-induced cytotoxicity in PC12 cells by guggulsterone.

The present study is to investigate the protective actions of guggulsterone against the cytotoxicity produced by exposure to hydrogen peroxide (H2O2) in PC12 cells. It was evaluated by MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide] reduction assay, lactate dehydrogenase (LDH) release assay, and the release of nitric oxide (NO). ROS and Ca2+ in cells were evaluated by DCFH and Fura 2-AM, respectively. Mitochondrial membrane potential (MMP) was assessed by the retention of rhodamine 123 (Rh 123). Apoptosis and morphological alteration in PC12 cells were monitored with flow cytometry and electric microscope. Vitamin E, a potent antioxidant, was employed as a comparative agent. The results showed that preincubation of PC12 cells with guggulsterone (0.1 - 10 micromol x L(-1)) prevented cytotoxicity induced by H2O2. Extracellular accumulation of LDH, NO and intracellular accumulation of ROS, Ca2+ resulting from H2O2 were significantly reduced by guggulsterone. Incubation of cells with H2O2 caused a marked decrease in MMP, which was significantly inhibited by guggulsterone. The percentage of H2O2-induced apoptosis in PC12 cells was 24.3%, and decreased in the presence of guggulsterone (0.1 - 10 micromol x L(-1)) by 18.4%, 15.9%, 11.8%, respectively. Guggulsterone exhibited comparable potency against oxidative stress induced by H2O2 in PC12 cells as that of vitamin E. The present findings showed that guggulsterone attenuated H2O2-induced cytotoxicity, extracellular accumulation of LDH and NO, intracellular accumulation of ROS and Ca2+, loss of MMP, and apoptosis, which may represent the cellular mechanisms for its neuroprotective action.

[Source and distribution characteristic of atmospheric organochlorine pesticides in the Pearl River Estuary and adjacent South China Sea].

Ship-board air samples were collected during the winter and spring cruise to the Pearl River Estuary (PRE) and adjacent South China Sea (SCS) in 2003 and were analyzed for organochlorine pesticides (OCPs). Meanwhile, air samples were collected at land-based sites in Guangzhou and Zhongshan for comparison. Results indicated that the detected OCPs were mainly of HCHs, DDTs and chlordane, its concentration ranged between 13-99, 73-390, 63-224 pg/m3 and 10-106, 429-1003, 1724-9638 pg/m3 during the winter and spring cruise, respectively. In general, the concentrations of OCPs were higher during spring cruise than in winter cruise. The measured OCPs concentration in the atmosphere over the PRE and adjacent SCS were found higher at sites close to continent and lower in outer sea, it is suggested that land-based source were to play a key role in the delivery of atmospheric OCPs. The alpha-HCH concentrations had significantly declined, higher gamma-HCH level may attribute to the present usage of lindane. Dicofol application and antifouling paints for fishing ships was suggested to be the important current "fresh" DDT source. The observed high level of chlordane during spring cruise could be related to the large amount usage of chlordane for termite control, as well as the long range transport from the west pacific region.

[Effects of paeoniflorin on cerebral energy metabolism, nitric oxide and nitric oxide synthase after cerebral ischemia in mongoliagerbils].

OBJECTIVE: To explore the effects of paeoniflorin on antagonising the delayed neuronal death (DND) induced by cerebral ischemia,and the relation between DND, cerebral tissue energy metabolism, nitric oxide (NO) and nitric oxide synthase (NOS). METHOD: Incomplete cerebral ischemia induced was induced by ligating bilateral arteries carotis communis for 20 min followed by reperfusion 48 h in rats. The indexes including Na(+)-K(+)-ATPase activity, lactic acid content, Ca(2+)-ATPase, Mg(2+)-ATPase activity, NO content and NOS activity were determined in fore brain cortex at 48 h after reperfusion. RESULT: Na(+)-K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase activity were lowered (P < 0.01), NO level was decreased (P < 0.01), NOS activity dropped (P < 0.01) in cerebral tissue at 48h after reperfusion, but lactic acid level had no change. Paeoniflorin could prevent reduction of Na(+)-K(+)-ATPase activity (P < 0.05, P < 0.01), increase NO level (P < 0.01), enhance NOS activity (P < 0.01) at 48h after reperfusion. CONCLUSION: DND induced by ischemia may be concerned with energy metabolism disorder and decrease of NO formation. Paeoniflorin may play the role of antagonising cerebral ischemia by adjusting cerebral energy metabolism and nitric oxide formation.

Up-regulation of P-glycoprotein expression by glutathione depletion-induced oxidative stress in rat brain microvessel endothelial cells.

Glutathione (GSH) depletion has been implicated in the pathogenesis of neurological diseases. During GSH depletion, cells of the blood-brain barrier (BBB) are subjected to chronic oxidative stress. In this study, we investigated the effect of such stress, produced with the GSH synthesis inhibitor l-buthionine-(S,R)-sulfoximine (BSO), on expression of P-glycoprotein (Pgp) in primary cultured rat brain microvessel endothelial cells that comprise the blood-brain barrier (BBB). Application of BSO to cell monolayers at concentrations up to 800 microm caused increases in expression of Pgp. Concentrations >or= 400 microm BSO decreased cell viability. Application of 200 microm BSO caused a significant increase in Pgp function activity, as assessed by rhodamine 123 (Rh123) accumulation experiments. At this concentration, BSO produced time-dependent decreases in levels of intracellular GSH and increases in levels of intracellular reactive oxygen species (iROS). The increases were also observed within 48 h following BSO treatment in mdr1a and mdr1b mRNA. Exposure of cells to BSO for 24 h produced maximal effects in the accumulation of iROS, and in expression and function of Pgp. The ROS scavenger N-acetylcysteine prevented ROS generation and attenuated the changes of both expression and activity of Pgp induced by BSO. Therefore, the transport of Pgp substrates may be affected by changing Pgp expression under conditions of chronic oxidative stress induced by GSH depletion.

[Relevant factors of lymphatic metastasis in rectal carcinoma].

OBJECTIVE: To investigate the rules of lymphatic metastasis of rectal carcinoma, and to help clinical diagnosis and treatment. METHODS: A retrospective analysis was performed in the 979 patients with rectal carcinoma who underwent surgical resection from 1995 to 2004. The associations between lymphatic metastasis and clinicopathologic variables were evaluated by Chi-squared test and logistic regression. RESULTS: The rate of lymph node metstasis was 71.4% for patients younger than 30 years old, 40.7% in the patients with tumor diameters over 6 centimeters, 82.5% in the patients with extraneous tumor invasion, 71.6% for patients of poor-differentiated adenocarcinoma, 70.4% for patients with mucoid adenocarcinoma, 100% for patients with signet-ring cell carcinoma and 46.4% for patients with more than half intestinal circumference invasion. Logistic regression analysis showed that the degree of lymphatic metastasis was related to the differentiating degrees, depths of tumor invasion and intestinal circumference invasion, and the differentiating degree was the major factor. CONCLUSION: The lymphatic metastasis of rectal carcinoma is related to age, tumor size, intestinal circumference invasion, depth of tumor invasion and the differentiating degree of the tumor; the differentiating degree is the major factor.

[One stage repairing operation in neonatal hypospadias].

OBJECTIVE: To explore the feasibility of one stage repairing operation on hypospadias in neonatal. METHODS: Sixteen newborn infants with congenital hypospadias dated from May 1998 to Jun. 2004, who was 1 to 29 days old with average 13 days, were performed one stage repairing operation, among whom hypospadias were classified: 4 cases of type I hypospadias, 8 cases of type II, 3 cases of type III and 1 case of type IV. RESULTS: Fourteen cases were cured, 1 case had urethral stricture, and 1 case had fistula. The cure rate of one stage operation was 87.5% (14/16). CONCLUSION: On the premise of the anesthetic safety, one stage hypospadias repairing operation is feasible in some selective cases in neonate.

Reversal of P-glycoprotein mediated multidrug resistance in K562 cell line by a novel synthetic calmodulin inhibitor, E6.

The overexpression of P-glycoprotein (P-gp) is associated with multidrug resistance (MDR) of tumor cells to a number of chemotherapeutic drugs. P-gp inhibitors have been shown to effectively reverse P-gp-mediated MDR in both in vitro and in vivo. Our previous studies demonstrated that E6, a novel synthetic calmodulin inhibitor, exhibited potent inhibitory effect on P-gp in rat brain microvessel endothelial cells (RBMECs). In the present study, the effect of E6 on MDR in a K562 MDR cell line (K562/DOX) highly expressing P-gp was studied and compared with that of a conventional P-gp inhibitor, verapamil (VER). E6 at concentrations of 1, 3, 10, 30 microM reduced the IC50 value of doxorubicin in K562/DOX cells from 79.19 microM to 35.18, 21.86, 6.31 and 1.97 microM, respectively. However, the IC50 value of doxorubicin in K562 sensitive subline was not significantly changed by E6. Using a DNA content analysis and an annexin V binding assay, the effects of E6 on doxorubicin-induced apoptosis were also examined. The results indicated that E6 effectively reversed the resistance to doxorubicin-induced apoptosis in K562/DOX cells. In addition, co-treatment of E6 and doxorubicin resulted in a remarkably G2/M blocking effect in K562/DOX cells. Furthermore, the treatment of K562/DOX cells with 10 microM E6 led to increased intracellular accumulation and decreased efflux of doxorubicin. Overall, the pharmacological effects of E6 on P-gp-mediated MDR is much stronger than that of positive control drug VER. These results suggested that E6 is a novel and potent MDR reversal agent and may be a potential adjunctive agent for tumor chemotherapy.