Glutathione protects against myocardial ischemia-reperfusion injury by detoxifying peroxynitrite

Peroxynitrite (ONOO(-)) formation during acute reperfusion of the ischemic heart contributes to the poor recovery of mechanical function. As glutathione (GSH) detoxifies ONOO(-), we studied whether it could protect isolated rat hearts subjected to exogenous ONOO(-)or to ischemia-reperfusion. We showed that GSH (300 microm, n=5) abolished the detrimental effect of ONOO(-)(80 microm, n=5) on mechanical function of aerobically perfused hearts. Hearts were subjected to 25 min aerobic perfusion, 20 min global, no-flow ischemia and 30 min reperfusion. GSH (3-300 microm, n=7-12) or saline vehicle (control, n=22) were infused for 10 min prior to ischemia and throughout reperfusion. During reperfusion, GSH caused a concentration-dependent improvement in the recovery of mechanical function, which was not associated with significant changes in the intracellular concentration of GSH. The concentration of dityrosine (a marker of ONOO(-) formation) in the coronary effluent during reperfusion was significantly reduced in GSH-treated hearts. The concentration of myocardial cGMP was significantly elevated by GSH during ischemia and early reperfusion. GSH improves the recovery of myocardial mechanical function after ischemia-reperfusion, an effect which may be related to the detoxification of ONOO(-)by GSH and the stimulation of soluble guanylate cyclase.     

Surgical validation and implications for transcatheter closure of quantitative echocardiographic evaluation of atrial septal defect

Accurate evaluation of secundum atrial septal defect (ASD) is important for the success of transcatheter closure. The purpose of this study was (1) to describe a quantitative evaluation by transthoracic (TTE) and transesophageal (TEE) echocardiography of the various morphologic features of ASD that might be important for patient selection for transcatheter closure, and (2) to assess the reliability of these 2 methods by surgical findings. Preoperative TTE and TEE were used to evaluate the ASD of 27 children undergoing surgical closure. Measurements included the diameters of ASD and the atrial septal lengths in the transverse and longitudinal axis, and the width of the superior, inferior, anteroinferior, and posterior septal margins. The shape and location of the ASD and the adequacy of the septal margins for anchoring occluding devices were determined. Echocardiographic data were compared with corresponding surgical measurements. No significant difference occurred in the means of all the parameters measured with the 3 methods, except for the transverse ASD diameter (p <0.05). Good agreement occurred between TTE and TEE and surgical data, except for the transverse ASD diameter, transverse atrial septal length, and the posterior septal margin on TTE. Intraclass correlations between TTE and TEE and surgical measurements of all parameters were good, except for the transverse ASD diameter. The accuracy in determining shape and location of the ASD by TTE and TEE were 100%, whereas that for determining the adequacy of septal margins was 98% and 97%, respectively. In conclusion, TTE and TEE are reliable methods for quantitative evaluation of ASD.     

Combined resection and radiofrequency ablation for multifocal hepatocellular carcinoma: Prognosis and outcomes

AIM: To analyze the combined treatment of resection and intraoperative radiofrequency ablation (RFA) for multifocal hepatocellular carcinoma in terms of prognosis and surgical outcomes.METHODS: This study was a retrospective case comparison study using prospectively collected data. The study covered the period from April 2001 to December 2006. The data of 200 patients with histologically confirmed hepatocellular carcinoma were reviewed. Nineteen patients (17 men and 2 women) having received resection in com...     

Resection margin in laparoscopic hepatectomy: a comparative study between wedge resection and anatomic left lateral sectionectomy

Background

Experience from open hepatectomy shows that anatomic liver resection achieves a better resection margin than wedge resection. In recent years, laparoscopic hepatectomy has increasingly been performed in patients with liver pathology including malignant lesions. Wedge resection (WR) and left lateral sectionectomy (LLS), which also represent non-anatomic and anatomic resection respectively, are the two most common types of laparoscopic hepatectomy performed. The aim of the present study was to compare the two types of laparoscopic hepatectomy with emphasis on resection margin.

Methods

Between November 2003 and July 2009, 44 consecutive patients who underwent laparoscopic hepatectomy were identified and retrospectively reviewed. The WR and LLS group of patients were compared in terms of operative outcomes, pathological findings, recurrence patterns and survival.

Results

Out of the 44 patients, 21 underwent LLS and 23 a WR. The two groups of patients were comparable in demographics. The two groups did not differ in conversion rate, blood loss, blood transfusion, mortality, morbidity and post-operative length of stay. The LLS group patients had significantly larger liver lesions, wider resection margin and less sub-centimetre margins. In patients with malignant liver lesions, there was no difference between the two groups in incidence of intra-hepatic recurrence and 3-year overall and disease-free survival.

Conclusion

Operative outcomes are similar between laparoscopic WR and LLS. However, WR is less reliable than LLS in achieving a resection margin of more than 1 cm. Larger studies involving more patients with longer follow-up are warranted to determine the impact of the resection margin on intra-hepatic recurrence and survival.     

p21-activated kinase 4 regulates ovarian cancer cell proliferation, migration, and invasion and contributes to poor prognosis in patients

Ovarian cancer is a lethal gynecological malignancy, and to improve survival, it is important to identify novel prognostic and therapeutic targets. In this study, we present a role for p21-activated kinase 4 (Pak4) in ovarian cancer progression. We show a significant association between increased expression of Pak4 and its activated form, phosphorylated (p)-Pak4 Ser(474), with metastasis of ovarian cancers, shorter overall and disease-free survival, advanced stage and high-grade cancers, serous/clear cell histological subtypes, and reduced chemosensitivity. Pak4 overexpression was also observed in ovarian cancer cell lines. Pak4 and p-Pak4 expression were detected both in the nucleus and cytoplasm of ovarian cancer cells, in vitro as well as in vivo. Stable knockdown of Pak4 in ovarian cancer cell lines led to reduced cell migration, invasion, and proliferation, along with reduced c-Src, ERK1/2, and epidermal growth factor receptor (EGFR) activation and decreased matrix metalloproteinase 2 (MMP2) expression. Conversely, Pak4 overexpression promoted ovarian cancer cell migration and invasion in a c-Src, MEK-1, MMP2, and kinase-dependent manner, and induced cell proliferation through the Pak4/c-Src/EGFR pathway that controls cyclin D1 and CDC25A expression. Stable knockdown of Pak4 also impeded tumor growth and dissemination in nude mice. This report reveals the association between Pak4 and important clinicopathologic parameters, suggesting Pak4 to be a significant prognostic marker and potential therapeutic molecular target in ovarian cancer. The implied possible cross-talk between Pak4 and EGFR suggests the potential of dual targeting of EGFR and Pak4 as a unique therapeutic approach for cancer therapy.     

A randomized trial of topical anesthesia comparing lidocaine versus lidocaine plus xylometazoline for unsedated transnasal upper gastrointestinal endoscopy

BACKGROUND:

The optimal topical anesthesia regimen for unsedated transnasal endoscopy is unknown. The addition of a nasal decongestant, such as xylometazoline (X), to a topical anesthestic may improve patient comfort.

OBJECTIVE:

To determine the effectiveness of lidocaine (L) versus L plus X (LX) for anesthesia in unsedated transnasal endoscopy.

METHODS:

Consecutive participants of the Aklavik Helicobacter pylori project were prospectively randomly assigned to receive LX or L for unsedated transnasal 4.9 mm ultrathin endoscopy. The primary outcome was overall procedure discomfort on a validated 10-point visual analogue scale (1 = no discomfort, 10 = severe discomfort). Secondary outcomes included pain, endoscope insertion difficulty, gagging, adverse events and encounter times. Results were presented as mean ± SD, difference in mean, 95% CI.

RESULTS:

A total of 181 patients were randomly assigned to receive LX (n=94) and L (n=87). Baseline characteristics between the two groups were similar (mean age 40 years, 59% women). Overall, patient procedural discomfort with LX and L were 4.2±2.4 versus 3.9±2.1, respectively (0.29; 95% CI −0.39 to 0.96). Transnasal insertion difficulty was significantly lower with LX than with L (2.4±2.1 versus 3.2±2.8, respectively [−0.80; 95% CI −1.54 to −0.06]). Compared with L, the use of LX was associated with significantly less time needed to apply anesthesia (2.4±1.8 min versus 3.5±2.2 min, respectively [−1.10; 95% CI −1.71 min to −0.50 min]) and less time for insertion (3.2±1.8 min versus 3.9±2.2 min, respectively [−0.70 min; 95% CI −1.30 min to −0.10 min]). Epistaxis was rare but occurred less frequently with LX (1.1%) than with L (4.6%) (P=0.19).

CONCLUSIONS:

LX did not improve patient comfort for transnasal endoscopy compared with L alone. However, LX was associated with less difficulty with endoscope transnasal insertion and reduced insertion time. Further studies on the optimal regimen and dosing of anesthesia are required.     

From the Cover: FERONIA receptor-like kinase regulates RHO GTPase signaling of root hair development

Plant RHO GTPases (RAC/ROPs) mediate multiple extracellular signals ranging from hormone to stress and regulate diverse cellular processes important for polarized cell growth, differentiation, development, reproduction, and responses to the environment. They shuttle between the GDP-bound inactive state and the GTP-bound activated state and their activation is predominantly mediated by a family of guanine nucleotide exchange factors (GEFs) referred to as ROPGEFs. Using the Arabidopsis ROPGEF1 as bait, we identified members of a receptor-like kinase (RLK) family as potential upstream regulators for RAC/ROP signaling. NADPH oxidase-derived reactive oxygen species (ROS) are emerging as important regulators for growth and development and play a crucial role in mediating RAC/ROP-regulated root hair development, a polarized cell growth process. We therefore screened T-DNA insertion mutants in these RLKs for root hair defects and found that mutations in one of them, At3g51550 encoding the FERONIA (FER) receptor-like kinase, induced severe root hair defects. We show that the fer phenotypes correlated with reduced levels of active RAC/ROPs and NADPH oxidase-dependent, auxin-regulated ROS accumulation in roots and root hairs and that up-regulating RAC/ROP signaling in fer countered the mutant phenotypes. Taken together, these observations strongly support FER as an upstream regulator for the RAC/ROP-signaled pathway that controls ROS-mediated root hair development. Moreover, FER was pulled down by ROP2 GTPase in a guanine nucleotide-regulated manner implying a dynamic signaling complex involving FER, a ROPGEF, and a RAC/ROP.     

Capsule endoscopy in small bowel tumors: A multicenter Korean study

Background and Aim: Capsule endoscopy (CE) has proven to be highly effective at detecting small bowel lesions in a variety of clinical conditions, but studies concerning the practical impact of CE on small bowel tumors are still scarce, especially in the Asian population. The aim of this study was to evaluate the diagnostic and therapeutic impact of CE in the field of small bowel tumors. Methods: CE records consecutively pooled from the beginning of use of CE in Korea, October 2001 until April 2008, in 14 centers throughout Korea were reviewed. Clinical information and CE video images of small bowel tumors were analyzed. Results: A total of 1332 cases undergoing CE were reviewed with all clinical indications. Small bowel tumors were diagnosed with CE in 57 (4.3%) of 1332 patients. The tumors were malignant in 33 cases, and included three adenocarcinomas, eight lymphomas, 20 gastrointestinal stromal tumors, and two metastatic cancers. The most frequent indications for CE in malignant tumors were obscure gastrointestinal bleeding, followed by abdominal pain and weight loss. Thirty of 57 tumors were identified exclusively by CE (diagnostic impact = 30/57), and they were smaller in size (mean, range: 14.3 mm, 2–35 mm) compared to the other tumors detected in radiological studies (48.7 mm, 10–110 mm). Seven patients underwent surgical resection (therapeutic impact = 7/57). Conclusion: CE effectively identifies small bowel tumors that are undetectable by conventional radiological studies (diagnostic impact = 52.6%) and can critically change the therapeutic course (therapeutic impact = 12.3%).     

Validation of the Hong Kong Chinese version of the St. George Respiratory Questionnaire in patients with bronchiectasis

STUDY OBJECTIVES: To validate the Hong Kong Chinese version of the St. George Respiratory Questionnaire (SGRQ-HK) in patients with bronchiectasis. DESIGN AND SETTING: Outpatients (93 patients; 61 women; mean age [+/- SD], 59.0 +/- 14.2 years) were assessed at baseline by the SGRQ-HK, the Hong Kong Chinese version of the 36-item short form health survey (SF-36-HK), and the hospital anxiety and depression scale (HADS). Forty randomly selected patients also were reassessed at 2 weeks for repeatability. Seventy-two patients were further reassessed at 6 months for responsiveness. Measurements and results: Cronbach alpha coefficients, which reflected internal consistency, were > 0.7 for all SGRQ-HK components except for symptoms (alpha = 0.59), and the intraclass correlation coefficients between baseline and the 2-week follow-up visits were between 0.80 and 0.94 (p > 0.05). SGRQ-HK component scores and total scores correlated with all the component scores of the SF-36-HK and the HADS (p < 0.02). SGRQ-HK component scores and total scores correlated with the scores of the SF-36-HK and the HADS, confirming the concurrent validity. All SGRQ-HK scores correlated negatively with FEV(1), FVC, and arterial oxygen saturation (p < 0.005), while the activity score correlated with the Karnofsky performance scale and the number of bronchiectatic lobes (p < 0.001). SGRQ-HK scores positively correlated with Borg scale scores, exacerbation frequency, and 24-h sputum volumes (p < 0.03). Patients with 24-h sputum volumes of > or = 10 mL or < 10 mL had significantly different SQRG-HK component scores and total scores (p < 0.002), although this sensitivity was not displayed by scores on the HADS or the SF-36-HK. Patients with 25% reductions in 24-h sputum volumes had significant improvements in SGRQ-HK activity scores, impact scores, and total scores (p < 0.02), but not in other quality-of-life measures or clinical parameters, indicating the responsiveness of the SGRQ-HK. CONCLUSION: The SGRQ-HK is a valid and sensitive instrument for determining quality of life in bronchiectasis patients.     

Stage-specific embryonic antigen-3 (SSEA-3) and β3GalT5 are cancer specific and significant markers for breast cancer stem cells

The discovery of cancer stem cells (CSCs), which are responsible for self-renewal and tumor growth in heterogeneous cancer tissues, has stimulated interests in developing new cancer therapies and early diagnosis. However, the markers currently used for isolation of CSCs are often not selective enough to enrich CSCs for the study of this special cell population. Here we show that the breast CSCs isolated with CD44⁺CD24^-/loSSEA-3⁺ or ESA^hiPROCR^hiSSEA-3⁺ markers had higher tumorigenicity than those with conventional markers in vitro and in vivo. As few as 10 cells with CD44⁺CD24^-/loSSEA-3⁺ formed tumor in mice, compared with more than 100 cells with CD44⁺CD24^-/lo. Suppression of SSEA-3 expression by knockdown of the gene encoding β-1,3-galactosyltransferase 5 (β3GalT5) in the globo-series pathway, led to apoptosis in cancer cells specifically but had no effect on normal cells. This finding is further supported by the analysis of SSEA-3 and the two related globo-series epitopes SSEA4 and globo-H in stem cells (embryonic stem cells and induced pluripotent stem cells) and various normal and cancer cells, and by the antibody approach to target the globo-series glycans and the late-stage clinical trials of a breast cancer vaccine.Cancer stem cells (CSCs), which are rare cells with the ability of self-renewal and tumor initiation, are closely related to cancer progression and specific targets for effective therapy and early diagnosis (1–5). To date, many CSCs have been identified and characterized by protein markers. Breast CSCs (BCSCs) were first discovered in 2003 by Al-Hajj et al. (6); it was demonstrated that breast cancer cells with CD44⁺CD24^-/lo expression have higher level of tumorigenicity than others and can form tumor in animals with ∼100 of such cells. In addition, other proteins such as ALDH-1, CD133, CD326 (ESA), CD201 (PROCR), and their combinations, are also reported as BCSCs biomarkers (7–9). However, the BCSCs obtained from the enrichment process based on these markers still contain a large number of noncancer stem cells, and study of such cells would provide nonspecific characteristics of CSCs. Therefore, new markers are required to enrich and obtain better-defined BCSCs for analysis and study.Glycolipids are known to be altered during cancer development (10–15). In our previous study, the globo-series glycans SSEA-3 (Gb5), SSEA-4 (sialyl-Gb5), and globo-H (fucosyl-Gb5) are found exclusively on the cell surface of many cancers, including breast cancer and BCSCs (16–18). We also reported that BCSCs carrying either ESA^hiPROCR^hi or CD44⁺CD24^-/lo showed high expression of these globo-series epitopes (19). SSEA-3 is synthesized from Gb4 by β3GalT5 (20), and globo-H and SSEA-4 are synthesized from SSEA-3 by fucosyltransferases 1 and 2 (FUT1, FUT2) (21, 22) and ST3 β-galactoside α-2,3-sialyltransferase 2 (ST3Gal2) (23), respectively. These reports prompt us to investigate whether SSEA-3 and the related glycans and enzymes in the globo-series pathway are cancer specific and are BCSC markers.