Mss51 protein inhibition serves as a novel target for type 2 diabetes: a molecular docking and simulation study

Myostatin is a widely recognized inhibitory factor of skeletal muscle growth and significantly influences muscle development and metabolism. In mice, myostatin inhibition improves insulin sensitivity, increases glucose uptake by skeletal muscle, and reduces body fat. Furthermore, Mss51 is downregulated in response to myostatin inhibition, and its deletion appears to improve the metabolic state of skeletal muscle and reduce adipose tissue, which makes Mss51 a potential target for the treatment of obesity and type 2 diabetes. Here, we report a computationally predicted and validated three-dimensional structure of Mss51. Computational screening was used to identify naturally occurring compounds from the Herbal and Specs chemical database that might inhibit Mss51, based on binding affinities and physiochemical and ADMET properties. ZINC00338371, ZINC95099599 and ZINC08214878 were found to bind to Mss51 with high binding affinity and specificity. In addition, 100 ns molecular dynamics simulations were conducted to assess the stabilities of the interactions between the three compounds and Mss51. MD simulation demonstrated that all three compounds bind to the active pocket site of Mss51 stably and cause conformation changes. ZINC00338371 was found to bind most stably with binding free energy -229.022 ± 13.776 kJ/mol to Mss51, suggesting that it has therapeutic potential as a treatment option for obesity and type 2 diabetes.Communicated by Ramaswamy H. Sarma.

Targeting myostatin using quercetin as a media supplement to improve myogenesis for cultured meat production: An in silico and in vitro study

Cultured meat (CM) is an alternative protein food and is produced by cultivating muscle satellite (stem) cells (MSCs) derived from livestock animals (bovine, chickens, and porcine) through myogenesis leading to generate muscle mass. Myostatin (MSTN) is well well-known negative regulator of myogenesis, and in the present study, in silico screening of natural compounds was performed to identify MSTN inhibitors. Interestingly, quercetin was found to inhibit MSTN (binding energy -7.40 kcal/mol), and this was further validated by a 100 ns molecular dynamics simulation. Quercetin was added to culture media to boost myogenesis, and its potent antioxidant property helped maintain media pH. Furthermore, quercetin increased the myotube thickness and length, increased MSC differentiation, and upregulated the gene and protein expressions of myoblast determination protein 1 (MYOD), Myogenin (MYOG), and Myosin heavy chains (MYH) in vitro. In addition, quercetin inhibited the activities of MSTN, activin receptor type-2B (ACVR2B), and SMAD2 and 3, and thus significantly enhanced MSC differentiation and myotube formation. Overall, this study shows that quercetin might be useful for enhancing large-scale CM production. It is hoped that this study provides a starting point for research in the CM area aimed to enhancing product quality, nutritional values, and the efficacy of large-scale production.

Therapeutic applications of ginseng for skeletal muscle-related disorder management

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

Therapeutic application of natural compounds for skeletal muscle-associated metabolic disorders: A review on diabetes perspective

Skeletal muscle (SM) plays a vital role in energy and glucose metabolism by regulating insulin sensitivity, glucose uptake, and blood glucose homeostasis. Impaired SM metabolism is strongly linked to several diseases, particularly type 2 diabetes (T2D). Insulin resistance in SM may result from the impaired activities of insulin receptor tyrosine kinase, insulin receptor substrate 1, phosphoinositide 3-kinase, and AKT pathways. This review briefly discusses SM myogenesis and the critical roles that SM plays in insulin resistance and T2D. The pharmacological targets of T2D which are associated with SM metabolism, such as DPP4, PTB1B, SGLT, PPARγ, and GLP-1R, and their potential modulators/inhibitors, especially natural compounds, are discussed in detail. This review highlights the significance of SM in metabolic disorders and the therapeutic potential of natural compounds in targeting SM-associated T2D targets. It may provide novel insights for the future development of anti-diabetic drug therapies. We believe that scientists working on T2D therapies will benefit from this review by enhancing their knowledge and updating their understanding of the subject.

Extracellular matrix: the critical contributor to skeletal muscle regeneration-a comprehensive review

The regenerative ability of skeletal muscle (SM) in response to damage, injury, or disease is a highly intricate process that involves the coordinated activities of multiple cell types and biomolecular factors. Of these, extracellular matrix (ECM) is considered a fundamental component of SM regenerative ability. This review briefly discusses SM myogenesis and regeneration, the roles played by muscle satellite cells (MSCs), other cells, and ECM components, and the effects of their dysregulations on these processes. In addition, we review the various types of ECM scaffolds and biomaterials used for SM regeneration, their applications, recent advances in ECM scaffold research, and their impacts on tissue engineering and SM regeneration, especially in the context of severe muscle injury, which frequently results in substantial muscle loss and impaired regenerative capacity. This review was undertaken to provide a comprehensive overview of SM myogenesis and regeneration, the stem cells used for muscle regeneration, the significance of ECM in SM regeneration, and to enhance understanding of the essential role of the ECM scaffold during SM regeneration.

The roles of growth factors and hormones in the regulation of muscle satellite cells for cultured meat production

Cultured meat is a potential sustainable food generated by the in vitro myogenesis of muscle satellite (stem) cells (MSCs). The self-renewal and differentiation properties of MSCs are of primary interest for cultured meat production. MSC proliferation and differentiation are influenced by a variety of growth factors such as insulin-like growth factors (IGF-1 and IGF-2), transforming growth factor beta (TGF-β), fibroblast growth factors (FGF-2 and FGF-21), platelet-derived growth factor (PDGF) and hepatocyte growth factor (HGF) and by hormones like insulin, testosterone, glucocorticoids, and thyroid hormones. In this review, we investigated the roles of growth factors and hormones during cultured meat production because these factors provide signals for MSC growth and structural stability. The aim of this article is to provide the important idea about different growth factors such as FGF (enhance the cell proliferation and differentiation), IGF-1 (increase the number of myoblasts), PDGF (myoblast proliferation), TGF-β1 (muscle repair) and hormones such as insulin (cell survival and growth), testosterone (muscle fiber size), dexamethasone (myoblast proliferation and differentiation), and thyroid hormones (amount and diameter of muscle fibers and determine the usual pattern of fiber distributions) as media components during myogenesis for cultured meat production.

Dipeptidyl peptidase-4 inhibitory potentials of Glycyrrhiza uralensis and its bioactive compounds licochalcone A and licochalcone B: An in silico and in vitro study

Type 2 diabetes mellitus (T2DM) is a growing global public health issue, and dipeptidyl peptidase-4 (DPP-4) is a potential therapeutic target in T2DM. Several synthetic anti-DPP-4 medications can be used to treat T2DM. However, because of adverse effects, there is an unmet demand for the development of safe and effective medications. Natural medicines are receiving greater interest due to the inherent safety of natural compounds. Glycyrrhiza uralensis (licorice) is widely consumed and used as medicine. In this study, we investigated the abilities of a crude water extract (CWE) of G. uralensis and two of its constituents (licochalcone A (LicA) and licochalcone B (LicB)) to inhibit the enzymatic activity of DPP-4 in silico and in vitro. In silico studies showed that LicA and LicB bind tightly to the catalytic site of DPP-4 and have 11 amino acid residue interactions in common with the control inhibitor sitagliptin. Protein-protein interactions studies of LicA-DPP4 and LicB-DPP4 complexes with GLP1 and GIP reduced the DPP-4 to GLP1 and GIP interactions, indicated that these constituents might reduce the degradations of GLP1 and GIP. In addition, molecular dynamics simulations revealed that LicA and LicB stably bound to DPP-4 enzyme. Furthermore, DPP-4 enzyme assay showed the CWE of G. uralensis, LicA, and LicB concentration-dependently inhibited DPP-4; LicA and LicB had an estimated IC50 values of 347.93 and 797.84 μM, respectively. LicA and LicB inhibited DPP-4 at high concentrations, suggesting that these compounds could be used as functional food ingredients to manage T2DM.

Identification and Evaluation of Traditional Chinese Medicine Natural Compounds as Potential Myostatin Inhibitors: An In Silico Approach

Myostatin (MSTN), a negative regulator of muscle mass, is reported to be increased in conditions linked with muscle atrophy, sarcopenia, and other muscle-related diseases. Most pharmacologic approaches that treat muscle disorders are ineffective, emphasizing the emergence of MSTN inhibition. In this study, we used computational screening to uncover natural small bioactive inhibitors from the Traditional Chinese Medicine database (~38,000 compounds) for the MSTN protein. Potential ligands were screened, based on binding affinity (150), physicochemical (53) and ADMET properties (17). We found two hits (ZINC85592908 and ZINC85511481) with high binding affinity and specificity, and their binding patterns with MSTN protein. In addition, molecular dynamic simulations were run on each complex to better understand the interaction mechanism of MSTN with the control (curcumin) and the hit compounds (ZINC85592908 and ZINC85511481). We determined that the hits bind to the active pocket site (Helix region) and trigger conformational changes in the MSTN protein. Since the stability of the ZINC85592908 compound was greater than the MSTN control, we believe that ZINC85592908 has therapeutic potential against the MSTN protein and may hinder downstream singling by inhibiting the MSTN protein and increasing myogenesis in the skeletal muscle tissues.

Myostatin and its Regulation: A Comprehensive Review of Myostatin Inhibiting Strategies

Myostatin (MSTN) is a well-reported negative regulator of muscle growth and a member of the transforming growth factor (TGF) family. MSTN has important functions in skeletal muscle (SM), and its crucial involvement in several disorders has made it an important therapeutic target. Several strategies based on the use of natural compounds to inhibitory peptides are being used to inhibit the activity of MSTN. This review delivers an overview of the current state of knowledge about SM and myogenesis with particular emphasis on the structural characteristics and regulatory functions of MSTN during myogenesis and its involvements in various muscle related disorders. In addition, we review the diverse approaches used to inhibit the activity of MSTN, especially in silico approaches to the screening of natural compounds and the design of novel short peptides derived from proteins that typically interact with MSTN.

IgLON5 Regulates the Adhesion and Differentiation of Myoblasts

IgLON5 is a cell adhesion protein belonging to the immunoglobulin superfamily and has important cellular functions. The objective of this study was to determine the role played by IgLON5 during myogenesis. We found IgLON5 expression progressively increased in C2C12 myoblasts during transition from the adhesion to differentiation stage. IgLON5 knockdown (IgLON5kd) cells exhibited reduced cell adhesion, myotube formation, and maturation and reduced expressions of different types of genes, including those coding for extracellular matrix (ECM) components (COL1a1, FMOD, DPT, THBS1), cell membrane proteins (ITM2a, CDH15), and cytoskeletal protein (WASP). Furthermore, decreased IgLON5 expression in FMODkd, DPTkd, COL1a1kd, and ITM2akd cells suggested that IgLON5 and these genes mutually control gene expression during myogenesis. IgLON5 immunoneutralization resulted in significant reduction in the protein level of myogenic markers (MYOD, MYOG, MYL2). IgLON5 expression was higher in the CTX-treated gastrocnemius mice muscles (day 7), which confirmed increase expression of IgLON5 during muscle. Collectively, these results suggest IgLON5 plays an important role in myogenesis, muscle regeneration, and that proteins in ECM and myoblast membranes form an interactive network that establishes an essential microenvironment that ensures muscle stem cell survival.

Quality Improvement of Capsular Polysaccharide in Streptococcus pneumoniae by Purification Process Optimization

Streptococcus pneumoniae is the causative agent of many diseases, most notably pneumonia. Most of the currently used vaccines to protect against this pathogen employ pneumococcal capsular polysaccharides (CPSs) as antigens, but purifying CPS of sufficient quality has been challenging. A purification process for CPS comprising conventional methods such as ultrafiltration, CTAB precipitation, and chromatography was previously established; however, this method resulted in high cell wall polysaccharide (CWPS) contamination, especially for serotype 5. Thus, a better purification method that yields CPS of a higher quality is needed for vaccine development. In this study, we significantly reduced CWPS contamination in serotype 5 CPS by improving the ultrafiltration and CTAB precipitation steps. Moreover, by applying an acid precipitation process to further remove other impurities, serotype 5 CPS was obtained with a lower impurity such as decreased nucleic acid contamination. This improved method was also successfully applied to 14 other serotypes (1, 3, 4, 6A, 6B, 7F, 9V, 11A, 14, 18C, 19A, 19F, 22F, and 23F). To assess the immunogenicity of the CPS from the 15 serotypes, two sets of 15-valent pneumococcal conjugate vaccines were prepared using the previous purification method and the improved method developed here; these vaccines were administered to a rabbit model. Enzyme-linked immunosorbent assay and opsonophagocytic assay demonstrated higher immunogenicity of the conjugate vaccine prepared using CPS produced by the improved purification process.

Influence of systemic bone mineral density on atlantoaxial subluxation in patients with rheumatoid arthritis

Osteopenia and osteoporosis were independent predictive factors for higher atlantoaxial subluxation occurrence in patients with lower body mass index. Our findings suggest that patients with rheumatoid arthritis with osteopenia or osteoporosis, particularly those with lower body mass index (BMI), should be screened regularly to determine the status of their cervical spines.

INTRODUCTION

Cervical spine involvement in rheumatoid arthritis (RA) patients may cause serious adverse effects on quality of life and overall health. This study aimed to evaluate the association between atlantodental interval (ADI), atlantoaxial subluxation (AAS), and systemic bone mineral density (BMD) based on BMI variations among established patients with RA.

METHODS

The ADI was transformed to the natural log scale to normalize distributions for all analyses. Multivariable linear regression analyses were used to identify independent predictive factors for ADI based on each BMD classification. Multivariate Cox regression analyses were also performed to identify independent predictive factors for the risk of AAS, which were classified by tertile groups of BMI.

RESULTS

A total of 1220 patients with RA who had undergone at least one or more cervical radiography and BMD assessments were identified and enrolled. We found that the association between BMD and ADI (β, -0.029; 95% CI, -0.059 to 0.002; p = 0.070) fell short of achieving statistical significance. However, the ADI showed a 3.6% decrease per 1 BMI increase in the osteoporosis group (β, -0.036; 95% CI, -0.061 to -0.011; p = 0.004). The osteopenia and osteoporosis groups showed about a 1.5-fold and a 1.8-fold increased risk of AAS occurrence among the first tertile of the BMI group.

CONCLUSIONS

Our study showed a possible association between lower BMD and AAS occurrence in patients with RA with lower BMI. Further studies are needed to confirm our findings.

Contrast-enhanced magnetic resonance angiography in the early period after kidney transplantation

Our objective was to evaluate the usefulness of three-dimensional (3-D) contrast-enhanced (CE) magnetic resonance angiography (MRA) to assess renal parenchyma, arterial inflow stenosis, and peritransplant fluid collections in the early period after kidney transplantation (KT). Between January 2010 and April 2011, we examined a consecutive series of 144 renal transplants using 3-D CE MRA at 14 days after KT. MRA showed parenchyma infarctions (n = 17, 11.8%), arterial inflow stenoses (n = 23, 16%), lymphoceles (n = 14, 9.7%), and hematomas (n = 6, 4.2%). The degree of renal transplant artery inflow stenosis was graded qualitatively based on diameter criterion; <50% = mild, 50% to 70% = moderate, and >70% = severe in 10 (6.9%), 5 (3.5%), and 8 (5.6%) subjects, respectively. The study recipients were divided into 3 groups according to the degree of renal artery inflow stenosis (group I: normal; group II: mild and moderate, <70%; group III: severe, >70%). Among group III patients who underwent digital subtraction angiography, 5 had percutaneous transluminal angioplasty or stenting performed after 1 month. Their mean resume creatinine levels at 1, 6, and 12 months after transplantation were not significantly different from those in the other groups (P = .391, .447, .110). The prevalence of graft loss (n = 2) was high in group III (P = .012), although the frequency of acute rejection episodes was not different among the groups (P = .890). The incidences of renal parenchyma infarction, peritransplant fluid collection and arterial inflow stenosis were unexpectedly high in the early period after KT. Thus, 3-D CE MRA provided a rapid global assessment of the renal parenchyma, transplant arterial system, and peritransplant fluid collection that can be helpful to detect or exclude many causes of renal transplant dysfunction.

A simple novel endoscopic successive suture device: a validation study for closure strength and reproducibility

BACKGROUND AND STUDY AIMS

Endoscopic surgical technology has been developing rapidly. Although several successful endoscopic closure devices have already been introduced, only a few of them have demonstrated improvements in closure strength and reproducibility over conventional endoscopic clip closures or hand sutures. The objective of this study was to test the feasibility of a novel successive suturing device (SSD) by measuring closure strength and reproducibility.

MATERIAL AND METHODS

Porcine stomach models were used in this study. Endoclips, full-thickness hand sutures, and the novel SSD sutures were used to close a perforation in the stomach wall, with 10 stomachs being tested for each closure method. Endoclips and SSD sutures were performed using a two-channel endoscope, and the hand sutures were performed from outside of the stomach wall. Air leakage pressure was measured to determine the closure strength and reproducibility of each method.

RESULTS

The mean air leakage pressure of the SSD closure was 62.7 ± 8.2 mmHg. SSD-treated stomachs exhibited significantly greater air leakage pressure than Endoclip-treated stomachs. The standard deviation of bursting pressure in SSD stomachs was found to be significantly smaller than that of hand-sewn stomachs but was not different from that of Endoclip stomachs.

CONCLUSIONS

The consistent closure strength of SSD stomachs demonstrated the reliability and reproducibility of this new closure method. These promising results in closure strength and reproducibility suggest the feasibility of the proposed device for clinical applications.

Clinical usefulness of 3-dimensional computerized tomographic renal angiography to detect transplant renal artery stenosis

OBJECTIVE

The aim of this study was to evaluate whether 3-dimensional computerized tomographic angiography (3D-CTA) is useful to detect transplant renal artery stenosis (TRAS).

METHODS

Fourteen patients with clinically suspected TRAS underwent color Doppler ultrasonography (CDU) and 3D-CTA before renal angiography. We compared 3D-CTA and CDU for accuracy based on the results of renal angiography. The safety of 3D-CTA was investigated by measuring the estimated glomerular filtration rate (eGFR) before and after the 3D-CTA examination.

RESULTS

The 10 men and 4 women who participated in this study showed a mean eGFR of 75 mL/min/1.73 m(2) (range 60-94). Of these, 9 patients were diagnosed with TRAS. 3D-CTA detected stenoses in all 9 patients, but CDU failed to detect it in 3, including, 2 with end-to-side arterial anastomoses, which may be more challenging to detect compared with end-to-end anastomoses. The stenotic area in 3D-CTA was similar to that detected by renal angiography (70 ± 12 vs 68 ± 11). The eGFR did not differ significantly before versus after the 3D-CTA examination; 72 ± 13 vs 69 ± 14 mL/min/1.73 m(2).

CONCLUSIONS

3D-CTA was an effective safe method to detect renal artery stenosis among transplant recipients with an eGFR >60 mL/min/1.73 m(2).

The effect of the respiratory cycle on liver stiffness values as measured by transient elastography

The findings of several studies suggest that liver stiffness values can be affected by the degree of intrahepatic congestion respiration influence intrahepatic blood volume and may affect liver stiffness. We evaluated the influence of respiration on liver stiffness. Transient elastography (TE) was performed at the end of inspiration and at the end of expiration in patients with chronic liver disease. The median values obtained during the inspiration set and during the expiration set were defined as inspiratory and expiratory liver stiffness, respectively. A total of 123 patients with chronic liver disease were enrolled (mean age 49years; 64.2% men). Liver cirrhosis coexisted in 29 patients (23.6%). Expiratory liver stiffness was significantly higher than inspiratory liver stiffness (8.7 vs 7.9kPa, P=0.001), while the expiratory interquartile range/median ratio (IQR ratio) did not differ from the inspiratory IQR ratio. Expiratory liver stiffness was significantly higher than inspiratory liver stiffness in 49 (39.8%) patients (HE group), expiratory liver stiffness was significantly lower than inspiratory stiffness in 15 (12.2%) patients, and there was no difference in 59 (48.0%) patients. Liver cirrhosis was more frequent in those who had a lower liver stiffness reading in expiration, and only the absence of liver cirrhosis was significantly associated with a higher reading in expiration in multivariate analysis. In conclusion, liver stiffness was significantly elevated during expiration especially in patients without liver cirrhosis. The effect of respiration should be kept in mind during TE readings.

The treatment of deep vein thrombosis immediately after kidney transplantation: a case report

Ipsilateral acute iliofemoral deep vein thrombosis (DVT) immediately after kidney transplantation is rare but highly morbid, resulting in allograft failure, rupture, or even death. Treatment modalities for iliofemoral DVT occurring just after transplantation are limited due to bleeding risk and impaired renal function. A 55-year-old woman with end-stage renal disease from hypertension underwent a living nonrelated donor procedure using a kidney from her husband. On postoperative day 1, the patient presented edema and pain in the right lower extremity associated with local heat and redness. The symptoms became aggravated with time. Duplex ultrasonography (US) revealed a DVT involving from the right femoral vein to the common iliac vein and an increased resistive index of 0.96 to 0.97. A venogram using carbon dioxide as the contrast medium showed also same findings as the duplex US. After inferior vena cava filter insertion, percutaneous transluminal thromboaspiration (PTA) was performed with complete removal of the thrombus. Early PTA with carbon dioxide as intravenous contrast material seemed to be an effective and safe procedure to treat this complication.

Efficacy of Helicobacter pylori eradication therapy in chronic liver disease

BACKGROUND/AIMS

Peptic ulcers occur more commonly in patients with liver cirrhosis (LC). Helicobacter pylori is recognized as the most important etiology in the pathogenesis of peptic ulcers. We investigated the efficacy of proton pump inhibitor (PPI)-based triple therapy in patients with chronic liver disease and peptic ulcer.

PATIENTS AND METHODS

One hundred sixty-three patients with LC or chronic hepatitis (CH) with a peptic ulcer and proven H. pylori infection were included. The combination of PPI, amoxicillin (1.0 g), and clarithromycin (500 mg), each given twice daily, was administered for 1 or 2 weeks. The eradication of H. pylori was determined by the rapid urease test, histology, or the 13C-urea breath test at least 4 weeks after completing the treatment.

RESULTS

The eradication rate of H. pylori was similar between the LC and CH groups; 82.6% and 88.1%, respectively. In addition, there were no significant differences in eradication rates between the patients with Child-Pugh class A and Child-Pugh class B/C disease. The side effects in each group were generally mild. Only the serum ALT levels showed a significant correlation with the success of H. pylori eradication in both the LC and CH groups.

CONCLUSION

The PPI-based triple therapy achieves high eradication rates for H. pylori infection, in patients with chronic liver disease, without significant side effects.

A phase II study of biweekly dose-intensified oral capecitabine plus irinotecan (bXELIRI) for patients with advanced or metastatic gastric cancer

Capecitabine, a prodrug of 5-FU, has been reported to generate maximal tumour activity at tumour sites and/or to improve drug tolerability as compared with 5-FU infusion, and it has also been demonstrated to act synergistically with irinotecan against some solid cancers. A previous study concluded that dose-intensified biweekly capecitabine seems to be more effective at increasing both response rate and progression-free survival time than conventional dose and schedule of capecitabine in colon cancer. We conducted this study to ascertain the efficacy and toxicity of dose-intensified biweekly capecitabine and irinotecan combination chemotherapy in chemotherapy-naïve advanced or metastatic gastric cancer patients. Patients were treated with irinotecan 130 mg m⁻² intravenously for 90 min on days 1 and 15. Capecitabine at 3500 mg m⁻² day⁻¹, divided into two sessions per day, was administered for seven consecutive days from days 1 and 15, and followed by a 7-day drug-free period, respectively. Fifty-five eligible patients were enrolled in this study from November 2003 to April 2006. There were 22 women and 33 men: median patient age was 54 years (range: 27–81). A total of 200 treatment cycles were administered at a median number of four per patient (range: 1–9). Intent-to-treatment analysis showed that one patient achieved complete response (1.8%), 23 partial response (41.8%), 15 stable disease (27.3%), 10 progressive disease (18.2%) and 6 were non-evaluable (10.9%). The overall response rate was 43.6% (95% confidence interval: 30.2–56.9). The common grade 3–4 toxicities were neutropenia in 12 (21.8%), nausea/vomiting in 3 (5.4%) and diarrhea in 4 (7.2%) patients. Median time to progression was 5 months (range: 0.5–11 months), median survival duration was 11 months (range: 0.5–45 months) and median response duration was 6 months (range: 0.5–9 months). Biweekly dose-intensified capecitabine and irinotecan combination chemotherapy was active for the treatment of advanced or metastatic gastric cancers with a tolerable safety profile.

Merlin facilitates ubiquitination and degradation of transactivation-responsive RNA-binding protein

The Nf2 tumor suppressor codes for merlin, a protein whose function is largely unknown. We have previously demonstrated a novel interaction between merlin and TRBP, which inhibits the oncogenic activity of TRBP. In spite of the significance of their functional interaction, its molecular mechanism still remains to be elucidated. In this report, we investigated how merlin inhibits the oncogenic activity of TRBP in association with cell growth conditions. In the human embryonic kidney 293 cell line, the level of endogenous merlin increased, whereas that of endogenous TRBP significantly decreased along with the increase in cell confluence. We demonstrated that the carboxyl-terminal region of TRBP was responsible for this phenomenon using stable cell lines expressing deletion mutants of TRBP. The overexpression of merlin decreased the protein level of TRBP, and the ubiquitin-like subdomain of merlin's FERM domain was important for this activity. We also demonstrated that TRBP is ubiquitinylated and the ubiquitinylated forms of TRBP are accumulated by ectopically expressed merlin or cell confluence in the presence of MG132, a proteasome inhibitor. Furthermore, we showed that the regulation of TRBP in response to cell confluence was abolished upon knockdown of merlin expression by specific small interfering RNA. Finally, we showed that ectopically expressed merlin restored cell-cell contact inhibition in cells stably expressing TRBP but not in TRBPDeltac. These results suggest that merlin is involved in the regulation of TRBP protein level by facilitating its ubiquitination in response to such cues as cell-cell contacts.

A case of primary adenosquamous carcinoma of the liver presented with liver abscess

Primary adenosquamous carcinoma of the liver is a very rare type of cholangiocarcinoma and is defined as a cancer containing both squamous and adenomatous components in the same lesion. Recently, we experienced a primary adenosquamous carcinoma of the liver presented as liver abscess. A 63-year-old man was presented with a 4-day history of fever and chill. The radiologic study showed a 4 cm-sized, central hypoattenuated mass with peripheral rim enhancement in the left lobe of the liver. Ultrasonography-guided aspiration and biopsy suggested an adenocarcinoma with abscess in the liver. At laparotomy, the tumor occupied the left lobe of the liver and invaded the right diaphragm. An extended left lobectomy and a partial excision of the involved diaphragm were done. Grossly, the tumor was 6 x 5 x 5 cm in size and had an eccentric necrosis. Microscopically, the tumor was composed of adenocarcinoma and squamous cell carcinoma with a transitional area.

Caspase-10 is an initiator caspase in death receptor signaling

A role for caspase-10, previously implicated in the autoimmune lymphoproliferative syndrome, in death receptor signaling has not been directly shown. Here we show that caspase-10 can function independently of caspase-8 in initiating Fas- and tumor necrosis factor-related apoptosis-inducing ligand-receptor-mediated apoptosis. Moreover, Fas crosslinking in primary human T cells leads to the recruitment and activation of caspase-10. Fluorescent resonance energy transfer analysis indicates that the death-effector domains of caspase-8 and -10 both interact with the death-effector domain of FADD. Nonetheless, we find that caspase-8 and -10 may have different apoptosis substrates and therefore potentially distinct roles in death receptor signaling or other cellular processes.

New approach to radial expansive force measurement of self expandable esophageal metal stents

The accurate measurement of radial expansive force is crucial for optimal design and implantation of self expandable esophageal metal stents. In the present study, a new method of measurement under experimental conditions simulating actual stent implantation has been developed. This method offers precise and reproducible measurements and can be applied to a wide variety of stent types. In particular, the method enables one to measure expansive pressure as well as the true radial expansive force up to the radial compression ratio of 72%, covering the range of compression often encountered in a partially obstructed lumen. The test results for various kinds of metal stents are presented and compared. Based on these results, three important points of observation critical in explaining and predicting the expansion characteristics of stents have been reported. Further understanding and characterization of these findings will be necessary for developing new stents with outstanding clinical efficacy.

Hypothalamic-pituitary-adrenal axis function and corticosterone receptor expression in behaviourally characterized young and aged Long-Evans rats

In the current investigation, hypothalamic-pituitary-adrenal (HPA) axis function was examined in young and aged male Long-Evans rats that were initially assessed on a version of the Morris water maze sensitive to cognitive impairment during ageing. In behaviourally characterized rats, a 1-h restraint stress paradigm revealed that plasma corticosterone concentrations in aged cognitively impaired rats took significantly longer to return to baseline following the stressor than did those in young or aged cognitively unimpaired rats. No differences in basal or peak plasma corticosterone concentrations, however, were observed between young or aged rats, irrespective of cognitive status. Using ribonuclease protection assays and in situ hybridization, we evaluated mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) mRNA abundance in young and aged rats characterized on the spatial task. Abundance of MR mRNA was decreased as a function of age in stratum granulosum but not hippocampus proper, and the decrease in MR mRNA was largely unrelated to cognitive status. However, GR mRNA was significantly reduced in several hippocampal subfields (i.e. stratum granulosum and temporal hippocampus proper) and other related cortical structures (medial prefrontal and olfactory regions) of aged cognitively impaired rats compared to either young or aged cognitively unimpaired cohorts, and was significantly correlated with spatial learning ability among the aged rats in each of these brain regions. In agreement with previous stereological data from this ageing model, no changes were detected in neuron density in the hippocampus of the rats used in the in situ hybridization analysis. These data are the first to describe a coordinated decrease in GR mRNA in a functional brain system including hippocampus and related cortical areas that occurs in tandem with impairments of the HPA response to stress and cognitive decline in ageing.

Inconsistent association of esophageal symptoms, psychometric abnormalities and dysmotility

OBJECTIVES

The aim of this study was to characterize the psychometric profiles of symptomatic patients with abnormal esophageal motility and symptomatic patients with normal manometric findings compared to asymptomatic controls.

METHODS

A total of 113 patients with abnormal esophageal motility (7 achalasia, 8 diffuse esophageal spasm, 27 nutcracker esophagus, 37 hypertensive lower esophageal sphincter, 21 hypotensive peristalsis, 13 failed peristalsis), 23 symptomatic controls with similar esophageal symptoms but normal manometry, and 27 asymptomatic controls were enrolled. Validated questionnaires assessing depression (Beck Depression Inventory), anxiety (Spielberger State Anxiety Inventory or Trait Anxiety Inventory), and somatization (Psychosomatic Symptom Checklist) were administered to all subjects.

RESULTS

Patients with both esophageal symptoms and either hypertensive lower esophageal sphincter, nutcracker esophagus, or hypotensive contractions exhibited increased somatization, acute anxiety, or depression compared to asymptomatic controls but not compared to symptomatic controls. On the other hand, the psychometric profiles of patients with achalasia and diffuse esophageal spasm were strikingly normal. Among esophageal symptoms, chest pain was closely correlated with psychometric abnormalities.

CONCLUSIONS

The esophageal symptoms of patients with abnormal esophageal motility may relate to the underlying psychological abnormalities, independent of manometric abnormalities.

Endoscopic removal of sharp foreign bodies impacted in the esophagus

BACKGROUND AND STUDY AIMS

Impacted sharp foreign bodies in the esophagus can be very difficult to manage. When attempts are made to remove such objects inappropriately, life-threatening complications such as perforation can occur. The aim of this study was to evaluate the safety and efficacy of endoscopic removal of impacted sharp foreign bodies in the esophagus using proximal dilatation with an oral side balloon or transparent cap.

PATIENTS AND METHODS

A total of 22 patients (10 men, 12 women) with impacted sharp foreign bodies in the esophagus underwent endoscopic extraction. The following technique was successfully performed at our hospital. An oral side balloon (Top Co., Japan) for esophageal variceal sclerotherapy was attached to the distal part of the endoscope. With the patient under local anesthesia, the endoscope was inserted as far as the proximal part of the esophageal foreign body. The oral side balloon was then gradually inflated. Dilatation of the proximal part of the esophagus made it possible to release the impacted sharp foreign body from the esophageal wall. A transparent cap was used for foreign bodies in the upper esophagus when there were difficulties with the oral side balloon.

RESULTS

The types of foreign body removed were fish bones (n = 9), press-through packages (n = 8), chicken bones (n =3), dentures (n = 1), and a wrist watch (n = 1). Endoscopic removal was successful in all but one of the cases, in which a fish bone had to be extracted surgically.

CONCLUSIONS

The proximal dilatation method using an oral side balloon or transparent cap is safe and effective in removing sharp foreign bodies from the esophagus, avoiding surgery and possible perforation.

Noninvasive graft flow and patency assessment following minimally invasive direct coronary artery bypass (MIDCAB) grafting

OBJECTIVE

Assessment of graft patency following minimally invasive direct coronary artery bypass (MIDCAB) surgery is essential in order to determine the efficacy of this technique. This study was conducted to evaluate the role of intraoperative and postoperative noninvasive flow and velocity measurements to follow and predict graft performance.

METHODS

Between April 1996 and July 1997, 130 patients had 133 grafts placed using MIDCAB techniques. Intraoperative transit-time ultrasound was used to assess graft patency and flow prior to wound closure. Also, serial transcutaneous doppler examinations were performed to evaluate graft patency on the first postoperative day, at two weeks, and at three months. Peak values for systolic and diastolic waveforms were measured for both flow and velocity, and the diastolic-to-systolic ratio was calculated at each time interval. Recatheterization was performed selectively for inadequate ultrasound flow or doppler velocity, or for patient symptoms.

RESULTS

Seven (5.3 %) grafts developed stenosis or occlusion. When compared to normal grafts, mean intraoperative flows, flow ratios, and velocity ratios were lower. Mean postoperative diastolic peak velocity (DPV) to systolic peak velocity (SPV) ratio remained stable over time for normal grafts; however, grafts with stenosis or occlusion demonstrated a diminished DPV/SPV ratio.

CONCLUSIONS

Intraoperative transit-time ultrasound and outpatient transcutaneous doppler examinations did not reach a predictive value for graft stenosis or occlusion following MIDCAB surgery in this series of patients. However, these data demonstrate trends that may help identify patients at an increased risk for unfavorable events, guiding the use of postoperative recatheterization in such patients.

Prevalence of endoscopic reflux esophagitis among Koreans

BACKGROUND AND AIM

Although reflux esophagitis is believed to be common in the Western population, very few epidemiologic data on reflux esophagitis in Koreans are available. The aims of this study were to evaluate the prevalence of endoscopic reflux esophagitis in patients who came for a physical check-up at Korea University Hospital, and to study the relationship between various factors relevant to reflux disease.

METHODS

This study was carried out prospectively on 7,015 patients who received an esophagogastroduodenoscopy from September 1996 to December 1997. Most of the patients were free of symptoms and had come for their self-paid check-up.

RESULTS

The overall prevalence of reflux esophagitis was 3.4%, and most of the patients had a mild degree of esophagitis representing grade 1 in 98.3% and grade 2 in 1.7%. The male: female ratio for esophagitis was 7 : 1, and the body mass index (BMI) was significantly higher in patients with reflux esophagitis. A hiatal hernia was found in 166 patients with esophagitis (68.6%), but only in 9.2% patients without esophagitis (P < 0.05). Smoking and alcohol consumption were associated with the development of reflux esophagitis (P < 0.05).

CONCLUSIONS

The prevalence of endoscopic reflux esophagitis among Koreans is 3.4%, and most of the patients had a mild grade esophagitis. Smoking, alcohol consumption, the presence of a hiatal hernia and a higher BMI are associated with the development of reflux esophagitis.

A novel cold-inducible zinc finger protein from soybean, SCOF-1, enhances cold tolerance in transgenic plants

Cold stress on plants induces changes in the transcription of cold response genes. A cDNA clone encoding C2H2-type zinc finger protein, SCOF-1, was isolated from soybean. The transcription of SCOF-1 is specifically induced by low temperature and abscisic acid (ABA) but not by dehydration or high salinity. Constitutive overexpression of SCOF-1 induced cold-regulated (COR) gene expression and enhanced cold tolerance of non-acclimated transgenic Arabidopsis and tobacco plants. SCOF-1 localized to the nucleus but did not bind directly to either C-repeat/dehydration (CRT/DRE) or ABA responsive element (ABRE), cis-acting DNA regulatory elements present in COR gene promoters. However, SCOF-1 greatly enhanced the DNA binding activity of SGBF-1, a soybean G-box binding bZIP transcription factor, to ABRE in vitro. SCOF-1 also interacted with SGBF-1 in a yeast two-hybrid system. The SGBF-1 transactivated the beta-glucuronidase reporter gene driven by the ABRE element in Arabidopsis leaf protoplasts. Furthermore, the SCOF-1 enhanced ABRE-dependent gene expression mediated by SGBF-1. These results suggest that SCOF-1 may function as a positive regulator of COR gene expression mediated by ABRE via protein-protein interaction, which in turn enhances cold tolerance of plants.

Differentiation between reinfection and recrudescence of helicobacter pylori strains using PCR-based restriction fragment length polymorphism analysis

The aim of this study was to evaluate whether PCR-based restriction fragment length polymorphism (RFLP) analysis was effective in differentiating between reinfection and recrudescence of H. pylori strains. Following a 1-2 week regimen of omeprazole 20 mg, amoxicillin 1.0 g, and clarithromycin 500 mg twice daily, twenty patients with duodenal ulcer were enrolled in the study. Ten patients (group 1, control) were not successfully treated, and another 10 patients (group 2) exhibited recurrence of infection 6-24 months following the therapy. Follow-up diagnosis was performed by Giemsa stain and CLO test. RFLP profiles of antral and midbody biopsy specimens were compared before and after therapy. PCR products using the ureC gene were digested with restriction enzymes Hha I, Mbo I, and Hind III, and the fragments generated were analyzed by agarose gel electrophoresis. Hha I, Mbo I, and Hind III digestion produced 13, 7, and 2 distinguishable digestion patterns, respectively. There was no difference in RFLP profiles seen before and after the therapy in 17 duodenal ulcer patients, while different RFLP profiles were discovered in 3 patients. Following treatment, one (group 2) patient differed in Mbo I, and two (one each from both groups) patients differed in Hha I and Mbo I RFLP patterns. Eight of group 2 patients showed recrudescence of previous infection and two patients had reinfection by another strain. This study supports the hypothesis that PCR-based RFLP analysis can be effective for differentiating reinfection and recrudescence of H. pylori strains following triple therapy.

The multifaceted role of Fas signaling in immune cell homeostasis and autoimmunity

Originally identified as a cell surface receptor that triggered the death of lymphocytes and tumor cells, it is now recognized that Fas (also known as CD95 or Apo-I) has distinct functions in the life and death of different cell types in the immune system. Fas signaling may also be involved in T cell costimulation and proliferation. Although Fas deficiency in humans and mice predisposes them towards systemic autoimmunity, Fas-FasL interactions can also facilitate organ-specific immunopathology. Proximal signaling by Fas and related receptors depends on subunit preassembly, which accounts for the dominant-negative effect of pathogenic receptor mutants and natural splice variants.

Effect of biphenyl dimethyl dicarboxylate on the humoral immunosuppression by ethanol

The present study was undertaken to investigate the effect of biphenyl dimethyl dicarboxylate (PMC) on the humoral immunosuppression by ethanol (EtOH) in ICR mice. PMC at a dose of 6 mg/kg was orally administered to mice daily for 28 consecutive days, and the control mice were given vehicle. Mice treated with EtOH were given freely with 20% EtOH instead of water. The results of this study are summarized as follows; a gain of body weight and the relative weights of spleen and liver were significantly increased by combination of PMC and EtOH, as compared with those in mice treated with EtOH alone. Splenic plaque forming cells (PFC) and hemagglutination (HA) titers to sheep red blood cells (SRBC), and the secondary IgG antibody response to bovine serum albumin (BSA) were decreased by the treatment of EtOH alone, then restored to normal level by PMC treatment. The elevations of serum glutamic-pyruvic transaminase (S-GPT) and total protein levels caused by EtOH were reduced to normal level by the combination of PMC and EtOH. In addition, lower serum albumin and A/G ratio were also increased to normal level. These findings indicate that PMC has a protective effect against EtOH-induced humoral immunosuppression.