Clinicopathological factors associated with clinical outcomes of endoscopic submucosal dissection for colorectal epithelial neoplasms

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) permits removal of colorectal epithelial neoplasms en bloc, but a substantial risk of procedure-related perforation has been reported. We sought to unravel the clinicopathological factors associated with the clinical outcomes of ESD for colorectal epithelial neoplasms in a large series.

PATIENTS AND METHODS

ESD was done in 278 patients with 292 colorectal tumors that fulfilled the inclusion criteria. The criteria for ESD were: lesion greater than 20 mm in size, lesion with fibrotic scarring, locally residual colorectal lesion, or invasive carcinoma with slight submucosal penetration. Resection was assessed as en bloc or piecemeal, complete (en bloc with tumor-free lateral and basal margins) or incomplete. Complications including perforation and bleeding were assessed, and factors related to each were analyzed using logistic regression. Patients underwent multiple follow-up endoscopic examinations (mean 4.6; median 4; range 2 - 9; total number 1010).

RESULTS

En bloc resection was achieved in 90.1 % of lesions (263/292) and resection was deemed to be complete in 233 (79.8 %). Right-side colonic location and the finding of fibrosis were the significant contributors to incomplete resection. Perforation was seen in 24 cases (8.2 %), and was associated with large tumor size and the presence of fibrosis. When the contributive factors for each were combined, the risks of incomplete resection and perforation were substantially increased.

CONCLUSION

The present study provides useful information for predicting risks for incomplete resection and complication in colorectal ESD.

Beneficial effects of leptin on glycaemic and lipid control in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and a high-fat diet

AIMS/HYPOTHESIS

We have previously demonstrated the therapeutic usefulness of leptin in lipoatrophic diabetes and insulin-deficient diabetes in mouse models and could also demonstrate its dramatic effects on lipoatrophic diabetes in humans. The aim of the present study was to explore the therapeutic usefulness of leptin in a mouse model of type 2 diabetes with increased adiposity.

METHODS

To generate a mouse model mimicking human type 2 diabetes with increased adiposity, we used a combination of low-dose streptozotocin (STZ, 120 microg/g body weight) and high-fat diet (HFD, 45% of energy as fat). Recombinant mouse leptin was infused chronically (20 ng [g body weight](-1) h(-1)) for 14 days using a mini-osmotic pump. The effects of leptin on food intake, body weight, metabolic variables, tissue triacylglycerol content and AMP-activated protein kinase (AMPK) activity were examined.

RESULTS

Low-dose STZ injection led to a substantial reduction of plasma insulin levels and hyperglycaemia. Subsequent HFD feeding increased adiposity and induced insulin resistance and further augmentation of hyperglycaemia. In this model mouse mimicking human type 2 diabetes (STZ/HFD), continuous leptin infusion reduced food intake and body weight and improved glucose and lipid metabolism with enhancement of insulin sensitivity. Leptin also decreased liver and skeletal muscle triacylglycerol content accompanied by an increase of alpha2 AMPK activity in skeletal muscle. Pair-feeding experiments demonstrated that leptin improved glucose and lipid metabolism independently of the food intake reduction.

CONCLUSIONS/INTERPRETATION

This study demonstrates the beneficial effects of leptin on glycaemic and lipid control in a mouse model of type 2 diabetes with increased adiposity, indicating the possible clinical usefulness of leptin as a new glucose-lowering drug in humans.

A case of atypical aortic coarctation with refractory congestive heart failure--treatment with axillo-iliac artery bypass

Coarctation of the aorta is rare. We present a case of atypical coarctation due to aortitis syndrome with congestive heart failure refractory to conventional medical treatment. Although indications for surgical treatment are not well established and, in general, treatment of choice is an aorto-aortic bypass, we selected axillo-iliac bypass with subcutaneous tunnel because of severe heart failure. Postoperatively, the pressure gradient disappeared and heart failure was improved.

C-type natriuretic peptide is a Schwann cell-derived factor for development and function of sensory neurones

Cyclic GMP (cGMP) is known to play important roles for neuronal development and neurite pathfinding. However, the regulatory mechanism that governs the synthesis of cGMP in the nervous system is not well defined. In the present study, we examined the role of C-type natriuretic peptide (CNP), which increases intracellular cGMP upon binding to its receptor, guanylyl cyclase (GC)-B, in the peripheral nervous system. Immunohistochemistry revealed that CNP is demonstrated in Schwann cells, whereas GC-B mRNA is highly expressed in dorsal root ganglion (DRG) neurones. In cultured DRG neurones, GC-B was demonstrated in dendrites of TrkA-positive cells, where it co-exists with cGMP-dependent protein kinase I (cGKI), the major intracellular mediator of cGMP actions. Addition of CNP in the culture medium increased the density of fine neurites, which was accompanied by the increase in phosphorylation of vasodilator-stimulated phosphoprotein, a cGKI substrate. Furthermore, in mice deficient for the CNP gene (CNP-KO), the numbers of TrkA-positive DRG neurones were diminished. Likewise, there were much less cGKI-positive neurones in DRG and cGKI-positive fibres in the dorsal spinal cord of CNP-KO than wild-type mice. Finally, the bone deformity-rescued CNP-KO mice displayed a decreased response to formalin-induced pain compared to wild-type. Taken together, these results suggest that CNP is derived from Schwann cells and plays an important role for the development and function of nociceptive sensory neurones.

Prevalence of interrelated autoantibodies in thyroid diseases and autoimmune disorders

OBJECTIVE

We determined the autoantibody profile in autoimmune thyroid diseases (AITD) and examined the distribution of thyroid-related autoantibodies in other autoimmune disorders.

METHODS

We tested sera from 234 patients with Graves' disease (GD), 130 with Hashimoto's thyroiditis (HT), 249 with other autoimmune diseases, and 50 healthy controls by enzyme-linked immunosorbent assay or radioimmunoassay.

RESULTS

Autoantibodies except TSH receptor antibody (Ab), anti-thyroglobulin (Tg) Ab and anti-thyroid peroxidase (TPO) Ab were not significantly prevalent in patients with AITD despite a significantly high elevation of thyroid-related Ab. Significant prevalence of autoantibodies related to AITD was observed in type 1 diabetes patients. Elevation of anti-Tg Ab was seen in patients with primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH), and anti-TPO Ab was elevated in patients with PBC. Although the prevalence of anti-acetylcholine receptor Ab and systemic lupus erythematosus (SLE)- related Ab was significant in AIH, primary Sjögren's syndrome (pSS)-related Ab were also found in both liver diseases. In myasthenia gravis (MG) patients, thyroid-related Ab and pSS-related Ab were detected in both MG groups, although SLE-related Ab were limited to the anti-muscle specific kinase Ab-positive MG patients. In patients with connective tissue diseases, anti- Tg Ab and anti-TPO Ab were significantly prevalent.

CONCLUSION

Thyroid-related Ab were significantly elevated in all autoimmune diseases. Conversely, the elevations of Ab were not significant in the patients with AITD, suggesting a close relationship between AITD and other immune-mediated diseases.

[How to treat arrhythmias in thoracic surgery]

After major noncardiac thoracic operations, various types of arrhythmia would occur. Particularly atrial fibrillation (Af), have remained one of the most frequent complications. In the literatures, risk factors for post operative Af have identified age, male, extent of pulmonary resection and mediastinal lymph node dissection. When we would meet the patients complicated with arrhythmia, the etiology of it must be identified and treated before operations. If accidental arrhythmia occurred during or after operations, the etiology of arrhythmia as hypoxia, hypercapnea, electrolyte disorder, overhydration and cardiac ischemia would be checked and cleared at first. Then appropriate drugs should be considered to use due to the type of arrhythmia. In supraventricular tachyarrhythmia, especially Af, landiolol and verapamil would be effective for the rate control and disopyramide and procaineamide for the defibrillation. Lidocaine and propranolol would be an appropriate choice for ventricular tachyarrhythmia during operations. For ventricular tachyarrhythmia related with acute myocardial infarction, lidocaine and mexiletine would be proper. In bradyarrhythmias a temporary pacing should be the first choice for urgent therapy. A prompt assessment and an adequate therapy must be mandatory for the arrhythmias after major noncardiac thoracic operations.

Cigarette smoking increases the mean platelet volume in elderly patients with risk factors for atherosclerosis

To study the effects of cigarette smoking and atherosclerosis on platelet size, we measured the mean platelet volume (MPV) and other platelet parameters in 142 elderly smokers and nonsmokers with or without atherosclerotic risk factors. The MPV and the platelet count were highest and their inverse correlation was strongest in the atherosclerotic smokers (r = 0.54, P < 0.05) when compared with the nonsmoking and non-atherosclerotic groups. A 10% decrease of MPV was found in 8 smoking subjects in the atherosclerotic group, who successfully discontinued smoking (P < 0.05). These results suggest that smoking may increase platelet consumption in atherosclerotic vessels and that subsequently megakaryocytes are activated to produce larger platelets, which are more active. Thus, an increase in MPV due to smoking may also contribute to the acceleration of atherosclerosis and should be considered as a risk factor for atherosclerotic disease.

Cerebellar ataxia in a patient receiving calcineurin inhibitors after living donor liver transplantation: a case report

Neurological complications of calcineurin inhibitors are frequent problems after transplantation. Cerebellar ataxia with other neurological findings and an abnormal density area in the subcortical white matter are found by MRI in the brains of most patients with central nervous system complications caused by calcineurin inhibitors. Such neurological complications are not life-threatening, but have a negative impact on the quality of life. We describe a 58-year-old woman who developed cerebellar ataxia at 4 days after living donor liver transplantation. She walked with a swaying gait, and after walking for 5 minutes she was unable to stand. Her symptoms persisted after a change from tacrolimus to cyclosporine, but dose reduction of cyclosporine and addition of mycophenolate mofetil cured the ataxia. We diagnosed a case of cerebellar ataxia without leukoencephalopathy or other neurological symptoms, as a new complication of calcineurin inhibitor treatment. We concluded that careful attention should be paid to neurological complications of calcineurin inhibitors.

Overexpression of connective tissue growth factor in podocytes worsens diabetic nephropathy in mice

Connective tissue growth factor (CTGF) is a potent inducer of extracellular matrix accumulation. In diabetic nephropathy, CTGF expression is markedly upregulated both in podocytes and mesangial cells, and this may play an important role in its pathogenesis. We established podocyte-specific CTGF-transgenic mice, which were indistinguishable at baseline from their wild-type littermates. Twelve weeks after streptozotocin-induced diabetes, these transgenic mice showed a more severe proteinuria, mesangial expansion, and a decrease in matrix metalloproteinase-2 activity compared to diabetic wild-type mice. Furthermore, diabetic transgenic mice exhibited less podocin expression and a decreased number of diffusely vacuolated podocytes compared to diabetic wild-type mice. Importantly, induction of diabetes in CTGF-transgenic mice resulted in a further elevation of endogenous CTGF mRNA expression and protein in the glomerular mesangium. Our findings suggest that overexpression of CTGF in podocytes is sufficient to exacerbate proteinuria and mesangial expansion through a functional impairment and loss of podocytes.

Partial functional overlap of the three ras genes in mouse embryonic development

In mammals, three ras genes, H-ras, N-ras and K-ras, encode homologous but distinct 21-kDa Ras proteins. We examined the in vivo functional relationship of the three ras genes in mouse embryonic development by investigating the phenotypes of mice deficient in one or multiple ras genes. H-ras-/- mice and N-ras-/- mice as well as a substantial proportion of H-ras-/-/N-ras-/- mice expressing only the K-ras gene were viable, while K-ras-/- mice were embryonically lethal, as have been reported previously. N-ras-/-/K-ras+/- mice died neonatally, while H-ras-/-/K-ras-/- embryos died much earlier than K-ras homozygous mutant fetuses. To further investigate the functional relationship of the ras genes in embryonic development, we introduced a human H-ras transgene into single or multiple ras mutant mice and found that the transgene rescued mice, including triple ras mutants, from embryonic lethality in association with correction of thin ventricular walls of the heart in null K-ras mutant mice. In situ hybridization revealed that the expression of the H-ras transgene on embryonic day E13.5 and E15.5 was more intense in major organs, including the heart, than those of endogenous ras genes. We therefore conclude that the functions of the ras genes are partially overlapping in mouse embryonic development.

Phase I study of S-1 combined with irinotecan (CPT-11) in patients with advanced colorectal cancer

PURPOSE

To determine the maximum tolerated dose, recommended dose and dose-limiting toxicities of irinotecan plus S-1 in advanced colorectal cancer.

PATIENTS AND METHODS

S-1 was administered orally at 80 mg/m2/day for 21 consecutive days followed by a 2-week rest. CPT-11 was given intravenously on days 1 and 15 of each course, at an initial dose of 60 mg/m2/day, stepping up to 80, 100, 120 or 140 mg/m2/day. Courses were repeated every 5 weeks, unless disease progression or severe toxicities were observed.

RESULTS

A total of 20 patients were entered in this study. The maximum tolerated dose of CPT-11 was considered to be 100 mg/m2, because 2 of 3 patients developed dose-limiting toxicities, such as anorexia, fatigue and diarrhea. Therefore, the recommended dose of CPT-11 was set at 80 mg/m2. Tumor responses were seen in 8 of 14 patients with measurable lesions.

CONCLUSION

A combination of S-1 with CPT-11 is safe and can be recommended for further phase II studies in patients with advanced colorectal cancer.

Ceramide and adenosine 5'-monophosphate-activated protein kinase are two novel regulators of 11beta-hydroxysteroid dehydrogenase type 1 expression and activity in cultured preadipocytes

Increased activity of intracellular glucocorticoid reactivating enzyme, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) in obese adipose tissue contributes to adipose dysfunction. As recent studies have highlighted a potential role of preadipocytes in adipose dysfunction, we tested the hypothesis that a variety of metabolic stress mediated by ceramide or AMP-activated protein kinase (AMPK) would regulate 11beta-HSD1 in preadipocytes. The present study is the first to show that 1) expression of 11beta-HSD1 in 3T3-L1 preadipocytes was robustly induced when cells were treated with cell-permeable ceramide analogue C(2) ceramide, bacterial sphingomyelinase, and sphingosine 1-phosphate, 2) 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR)-induced activation of AMPK augmented the expression and enzyme activity of 11beta-HSD1, and 3) these results were reproduced in human preadipocytes. We demonstrate for the first time that C(2) ceramide and AICAR markedly induced the expression of CCAAT/enhancer-binding protein (C/EBP) beta and its binding to 11beta-HSD1 promoter. Transient knockdown of C/EBPbeta protein by small interfering RNA markedly attenuated the expression of 11beta-HSD1 induced by C(2) ceramide or AICAR. The present study provides novel evidence that ceramide- and AMPK-mediated signaling pathways augment the expression and activity of 11beta-HSD1 in preadipocytes by way of C/EBPbeta, thereby highlighting a novel, metabolic stress-related regulation of 11beta-HSD1 in a cell-specific manner.

Intermittent force induces high RANKL expression in human periodontal ligament cells

Intermittent compressive force stimulates bone resorption in orthodontic treatment. This study examined the molecular mechanism in human periodontal ligament (PDL) cells stimulated by an intermittent force. PDL cells were subjected to compressive force (2.0 or 5.0 g/cm(2)) for 2-4 days. Continuous or intermittent force was applied all day or for 8 hrs per day, respectively. At days 3 and 4, cell damage was less with intermittent force than with continuous force. At day 4, RANKL and IL-1beta expressions were greater with intermittent force than with continuous force. An IL-1 receptor antagonist inhibited the compressive force-induced RANKL expression. These findings indicate that IL-1beta is an autocrine factor regulating compressive force-induced RANKL expression in PDL cells, and that intermittent force can effectively induce RANKL in PDL cells with less cell damage.

Neutrophil gelatinase-associated lipocalin as the real-time indicator of active kidney damage

Neutrophil gelatinase-associated lipocalin (Ngal, 24p3, SIP24, lipocalin 2, or siderocalin) was originally purified from neutrophils, but with unknown function. Recently, it was identified that Ngal activates nephron formation in the embryonic kidney, is rapidly and massively induced in renal failure and possesses kidney-protective activity. We would like to propose that blood, urine, and kidney Ngal levels are the real-time indicators of active kidney damage, rather than one of many markers of functional nephron number (as Forest Fire Theory). Ngal is a novel iron-carrier protein exerting pleiotropic actions including the upregulation of epithelial marker E-cadherin expression, opening an exciting field in cell biology.

Substance P stimulates late-stage rat osteoblastic bone formation through neurokinin-1 receptors

Substance P (SP) is a widely distributed neuropeptide that works as a neurotransmitter and neuromodulator. Recently, SP receptors, particularly neurokinin-1 receptors (NK(1)-Rs) that have a high affinity for SP, have been observed not only in neuron and immune cells, but also in other peripheral cells, including bone cells. To identify the role of SP in bone formation, we investigated the expression of NK(1)-Rs in osteoblastic cells and the effects of SP on bone formation by rat calvarial osteoblastic cells. Rat calvarial osteoblastic cells were isolated and cultured for 3 weeks in alpha-MEM containing 10% serum, ascorbic acid, dexamethasone, and beta-glycerophosphate. We then investigated NK(1)-R expression, SP effects on osteoblastic bone formation, and osteocalcin mRNA expression in osteoblastic cells. RT-PCR and immunocytochemistry showed that NK(1)-R mRNA was expressed and NK(1)-R was present in 14-day, but not 7-day, cultured calvarial osteoblasts. Bone formation by cultured osteoblastic cells significantly increased after the addition of 10(-8)-10(-6)MSP. During 3 weeks of culture, the addition of SP in the first week did not significantly increase bone formation, whereas adding SP during the first and second week or all 3 weeks significantly increased calvarial osteoblastic bone formation. Furthermore, semi-quantitative RT-PCR indicated that SP stimulated osteocalcin mRNA expression in the osteoblasts at day 14 or day 21, whereas SP did not stimulated the runX2 or type I collagen mRNA expression at day 7 but stimulated them at day 14. These results indicate that SP stimulates bone formation by osteoblastic cells via NK(1)-Rs at late-stage bone formation. These effects were dependent on the expression of NK(1)-R in osteoblastic cells. Our findings suggest that SP secreted from sensory neurons may modulate bone formation after the expression of SP receptors.

Transgenic overexpression of brain natriuretic peptide prevents the progression of diabetic nephropathy in mice

AIMS/HYPOTHESIS

Brain natriuretic peptide (BNP) is a potent vasorelaxing and natriuretic peptide that is secreted from the heart and has cardioprotective properties. We have previously generated hypotensive transgenic mice (BNP-Tg mice) that overproduce BNP in the liver, which is released into the circulation. Using this animal model, we successfully demonstrated the amelioration of renal injury after renal ablation and in proliferative glomerulonephritis. Glomerular hyperfiltration is an early haemodynamic derangement, representing one of the key mechanisms of the pathogenesis of diabetic nephropathy. Based on the suggested involvement of increased endogenous natriuretic peptides, the aim of this study was to investigate their role in the development and progression of diabetic nephropathy.

MATERIALS AND METHODS

We evaluated the progression of renal injury and fibrogenesis in BNP-Tg mice with diabetes induced by streptozotocin. We also investigated the effect of BNP on high glucose-induced signalling abnormalities in mesangial cells.

RESULTS

After induction of diabetes, control mice exhibited progressively increased urinary albumin excretion with impaired renal function, whereas these changes were significantly ameliorated in BNP-Tg mice. Notably, diabetic BNP-Tg mice revealed minimal mesangial fibrogenesis with virtually no glomerular hypertrophy. Glomerular upregulation of extracellular signal-regulated kinase, TGF-beta and extracellular matrix proteins was also significantly inhibited in diabetic BNP-Tg mice. In cultured mesangial cells, activation of the above cascade under high glucose was abrogated by the addition of BNP.

CONCLUSIONS/INTERPRETATION

Chronic excess of BNP prevents glomerular injury in the setting of diabetes, suggesting that renoprotective effects of natriuretic peptides may be therapeutically applicable in preventing the progression of diabetic nephropathy.

2'-,5'-Oligoadenylate synthetase response ratio predicting virological response to PEG-interferon-α2b plus ribavirin therapy in patients with chronic hepatitis C

OBJECTIVE

Although all the mechanisms of elimination of hepatitis C virus (HCV) by Interferon (IFN) have not been fully elucidated, the 2'-5'-oligoadenylate (2-5A) system is one of the mechanisms of the antiviral effect of IFN. Consequently, the measurement of 2'-5'-oligoadenylate synthetase (2-5AS) activity could be useful for the evaluation of IFN treatment. This retrospective study was aimed at assessing whether 2-5AS activity functions as a clinical marker of virological response to PEG-interferon-alpha2b (PEG-IFN) plus ribavirin therapy of chronic hepatitis C.

METHODS

The 32 patients included in this study had high viral loads of serum HCV-RNA of genotype 1b with chronic hepatitis C. All the patients received a regimen of PEG-IFN plus ribavirin for 48 weeks, and were then divided into two groups: one group (effective group) with undetectable serum HCV-RNA levels at 24 weeks (n = 22) of therapy, the other group (ineffective group) with persistent presence of HCV-RNA in serum at 24 weeks (n = 10). The 2-5AS activity in serum was measured 2, 8 and 12 weeks before initial administration.

RESULTS

The 2-5AS response ratio (measured value/measured value of baseline 2-5AS) at 2, 8 and 12 weeks after the administration in the effective group was significantly higher than that in the ineffective group.

CONCLUSIONS

These results suggest that the ratio of 2-5AS is closely related to the antiviral effect, and that the measurement of 2-5AS response ratio may be a useful clinical parameter of virological response to PEG-IFN plus ribavirin therapy of chronic hepatitis C.

Physical and functional interactions between Daxx and STAT3

Signal transducer and activator of transcription 3 (STAT3) play key roles in the intracellular signaling pathways of the interleukin (IL)-6 family of cytokines, which exhibit a diverse set of cellular responses, including cell proliferation and differentiation. Dysregulated IL-6/STAT3 signaling is involved in the pathogenesis of several diseases, for example autoimmune diseases and tumors. Type I interferon (IFN) induces the expression of proapoptotic genes and has been used in the clinical treatment of several tumors. In the present study, we found that type I IFN suppressed IL-6/STAT3-mediated transcription and gene expression. Furthermore, a type I IFN-induced protein, Daxx, also suppressed STAT3-mediated transcriptional activation, while overexpression of Daxx inhibited IL-6/STAT3-mediated gene expression. Importantly, small-interfering RNA-mediated reduction of Daxx expression enhanced IL-6/leukemia inhibitory factor (LIF)-induced STAT3-dependent transcription. Co-immunoprecipitation studies revealed a physical interaction between Daxx and STAT3 in transiently transfected 293T cells. We further found that Daxx and STAT3 were co-localized in the nucleus. These results indicate that Daxx may serve as a transcriptional regulator of type I IFN-mediated suppression of the IL-6/STAT3 signaling pathway.

Expression of the gene for a membrane-bound fatty acid receptor in the pancreas and islet cell tumours in humans: evidence for GPR40 expression in pancreatic beta cells and implications for insulin secretion

AIMS/HYPOTHESIS

G protein-coupled receptor 40 (GPR40) is abundantly expressed in pancreatic beta cells in rodents, where it facilitates glucose-induced insulin secretion in response to mid- to long-chain fatty acids in vitro. However, GPR40 gene expression in humans has not been fully investigated, and little is known about the physiological and pathophysiological roles of GPR40 in humans. The aim of this study, therefore, was to examine GPR40 expression and its clinical implications in humans.

METHODS

GPR40 mRNA expression in the human pancreas, pancreatic islets and islet cell tumours was analysed using TaqMan PCR.

RESULTS

GPR40 mRNA was detected in all human pancreases collected intraoperatively. It was enriched approximately 20-fold in isolated islets freshly prepared from the pancreases of the same individuals. The estimated mRNA copy number for the GPR40 gene in pancreatic islets was comparable to those for genes encoding sulfonylurea receptor 1, glucagon-like peptide 1 receptor and somatostatin receptors, all of which are known to be expressed abundantly in the human pancreatic islet. A large amount of GPR40 mRNA was detected in insulinoma tissues, whereas mRNA expression was undetectable in glucagonoma or gastrinoma. The GPR40 mRNA level in the pancreas correlated with the insulinogenic index, which reflects beta cell function (r=0.82, p=0.044), but not with glucose levels during the OGTT, the insulin area under the OGTT curve or the index for the homeostasis model assessment of insulin resistance (HOMA-IR).

CONCLUSIONS/INTERPRETATION

The present study provides evidence for GPR40 gene expression in pancreatic beta cells and implicates GPR40 in insulin secretion in humans.

Induction of apoptosis by carbazole alkaloids isolated from Murraya koenigii

In the current study, we isolated 10 carbazole alkaloids from the plant species Murraya koenigii (Rutaceae), and examined their effects on the growth of the human leukemia cell line HL-60. Three carbazole alkaloids, mahanine (6), pyrayafoline-D (7) and murrafoline-I (9), showed significant cytotoxicity against HL-60 cells. Fluorescence microscopy with Hoechst 33342 staining revealed that the percentage of apoptotic cells with fragmented nuclei and condensed chromatin was increased in a time-dependent manner after treatment with each alkaloid. Interestingly, each carbazole alkaloid induced the loss of mitochondrial membrane potential. In addition, both caspase-9 and caspase-3 were also time-dependently activated upon treatment with the alkaloids. Caspase-9 and caspase-3 inhibitors suppressed apoptosis induced by these alkaloids. The results suggest that these three alkaloids induced apoptosis in HL-60 cells through activation of the caspase-9/caspase-3 pathway, through mitochondrial dysfunction.

Negative correlation between bone mineral density and TSH receptor antibodies in male patients with untreated Graves' disease

INTRODUCTION

Although it has been established that hyperthyroidism leads to reduced bone mineral density (BMD), with accelerated bone turnover promoting bone resorption in female patients, there is a dearth of data for male patients with hyperthyroidism. This study evaluated BMD and bone metabolism in male patients with Graves' disease.

METHODS

The study included 56 Japanese male patients with newly diagnosed Graves' disease and 34 normal Japanese male control subjects of similar age and body mass index. We used dual energy x-ray absorptiometry to measure BMD at sites with different cortical/cancellous bone ratios (lumbar spine, femoral neck, and distal radius).

RESULTS

At the lumbar spine and the distal radius, BMD and T-scores were significantly lower for patients than for controls. At the femoral neck, on the other hand, the same values were relatively, but not significantly, lower in patients than in controls. However, Z-scores at all three sites were significantly lower for patients than for controls. The Z -score at the distal radius of patients was significantly lower than that at their lumbar spine and femoral neck. In addition, Z-score at the distal radius correlated negatively with age, free thyroxine, thyroid stimulating hormone receptor antibodies, thyroid stimulating antibody, and urinary N-terminal telopeptide of type I collagen normalized by creatinine.

CONCLUSIONS

These results indicate a high prevalence of cortical bone loss in male patients with Graves' disease, especially elderly patients. We conclude that BMD measurement is crucial in all Graves' disease patients regardless of their gender and that the radial BMD as well as BMD at the lumbar spine and femoral neck should be monitored to effectively prevent bone loss and subsequent fracture.

Importance of lymph vessels in gastric cancer: a prognostic indicator in general and a predictor for lymph node metastasis in early stage cancer

BACKGROUND

Metastasis to regional lymph nodes (LNs) through lymphatic vessels is common in cancer progression and is an important prognostic factor in many cancers. Recent evidence suggests that tumour lymphangiogenesis promotes lymphatic metastasis.

AIMS

To study the role of lymph vessel density (LVD) in gastric cancer and investigate whether LVD is associated with LN metastasis/prognosis.

METHODS

Lymphatics of 117 primary human gastric cancer cases were investigated by quantitative immunohistochemical staining for podoplanin. The relation between LVD and LN metastasis and other established clinicopathological parameters was analysed. The relation between LVD and prognosis was also studied.

RESULTS

Mean LVD of "hot spots" was 11.6/case. LVD significantly correlated with LN and podoplanin positive lymphatic invasion. High LVD was associated with worse overall survival. In multivariate analysis, positive LVD was a significant independent predictor of overall survival, depth of invasion, and TNM stage. LVD significantly correlated with LN metastasis at surgery and podoplanin positive lymphatic invasion. In multivariate analysis, positive LVD was an independent significant predictor of LN metastasis.

CONCLUSIONS

Increased podoplanin expression is significantly associated with LN metastasis, and may play an important role in detecting LN metastasis in gastric cancer. Furthermore, LVD may be a significant prognostic factor in gastric cancer at any stage. In addition, LVD and lymph vessel invasion detected by podoplanin immunohistochemistry are associated with LN metastasis in T1 early gastric cancer. LVD assessment by podoplanin immunohistochemistry may become a useful predictor of LN metastasis in T1 early gastric cancer and may influence the decision making process for additional surgery.

Modification of lipases with poly(ethylene glycol) and poly(oxyethylene) detergents and their catalytic activities in organic solvents

The alpha-chymotrypsin-poly(ethylene glycol) complex, which was prepared by lyophilizing an aqueous solution, was found to have high catalytic activity in organic media even when the molar ratio of polymer/enzyme in its preparation stage is unity. In this study, we obtained freeze-dried complexes of lipases and poly(ethylene glycol) or poly(oxyethylene) detergents including newly synthesized gemini-type detergents, and their transesterification activity in organic solvents was evaluated. The freeze-dried lipase from Pseudomonas cepacia prepared by using each modifier showed enhanced transesterification activity, exhibiting a similar dependence on the concentration of the modifier in the preparation stage to that of the alpha-chymotrypsin-poly(ethylene glycol) complex; in contrasts, the one from Candida rugosa did not do so.

Effect of glycine on 5-aminolevulinic acid biosynthesis in heterotrophic culture of Chlorella regularis YA-603

Chlorella regularis strain YA-603 was previously found to exhibit a comparatively high growth rate and improved 5-aminolevulinic acid (ALA) productivity when cultured heterotrophically. Although the universal tetrapyrrole precursor ALA is synthesized from glutamate in algae and higher plants, in this study the addition of glutamate to the medium did not enhance ALA production in the heterotrophic culture of C. regularis YA-603. On the other hand, the addition of glycine, which is a precursor of ALA biosynthesis via the Shemin pathway in animal cells and some bacteria, enhanced both the specific growth rate and ALA production. Moreover, when a second glycine addition was made during the culture, the ALA concentration increased by about 1.5 times compared to that obtained with one glycine addition. From these results, it is suggested that the Shemin pathway contributes to ALA production, and that addition of glycine in the heterotrophic culture of C. regularis YA-603 can significantly increase the amount of ALA produced.

Decreased bone mineral density at the distal radius, but not at the lumbar spine or the femoral neck, in Japanese type 2 diabetic patients

The purpose of this study is to assess the association between type 2 diabetes and bone mineral density. This study included 145 Japanese patients (64 men and 81 women) with type 2 diabetes and 95 non-diabetic control subjects (41 men and 54 women) of similar age. We measured bone mineral density (BMD) at the sites with different cortical/cancellous bone ratio (lumbar spine, femoral neck, and distal radius) using dual-energy X-ray absorptiometry. BMD and Z score at the distal radius were significantly lower in type 2 diabetic patients than those in control subjects, and in type 2 diabetic patients, the Z score at the distal radius was lower than that at their own lumbar spine and femoral neck. In type 2 diabetic patients, negative correlation between BMD and the mean HbA1c during the previous 2 years was found significantly at the distal radius in both genders and at the femoral neck in women. These results indicate the selective cortical bone loss in type 2 diabetes and suggest the importance of also determining BMD at the radius and keeping good metabolic control to prevent bone loss in type 2 diabetic patients.

Free-prefabricated auricular composite graft: a new method for reconstruction following extended hemilaryngectomy

A free-prefabricated auricular composite graft was applied in two patients who underwent extended hemilaryngectomy. Good phonatory and respiratory functions were obtained without any significant aspiration. Although this reconstructive method is a two-staged procedure involving microsurgical techniques, we believe that it provides a good physiologic reconstruction of the larynx and trachea.

Interferon-beta induction/interferon-alpha2b plus ribavirin therapy in patients with chronic hepatitis C

Treatment of chronic hepatitis C virus (HCV) infection with interferon (IFN) and ribavirin improves the rate of eradication of the virus by less than 20% in patients with genotype 1b and a high viral load. In this study we assessed whether IFN-beta induction/IFN-alpha2b plus ribavirin enhances the efficacy of the therapy in patients with chronic hepatitis C. The efficacy of IFN-beta induction/IFN-alpha2b plus ribavirin therapy (group A, n=7) was compared with that of IFN-alpha2b plus ribavirin (group B, n=7) in 14 patients with high levels of HCV-RNA (> 100 K/U/ml). No significant differences were observed in the clearance of HCV-RNA between the two groups (A and B, respectively) 2 weeks after the start of the treatment (0% and 14.3%), at the end of the treatment (71.4% and 100%) and 6 months after the end of the treatment (28.6% and 14.3%). Recovery was complete in 28.6% and 14.3%, transient in 42.9% and 85.7% and absent in 28.6% and 0% in groups A and B, respectively. Early log changes in the viral load from the baseline after 2 weeks of treatment were 2.41 +/- 0.91 and 2.77 +/- 0.20 in groups A and B, respectively, with no significant difference between the two groups. In the present study, we were not able to demonstrate that IFN-beta induction/IFN-alpha2b plus ribavirin therapy was superior to IFN-alpha2b plus ribavirin therapy in patients with genotype 1b and high viral loads.

Osteoprotegerin (OPG) acts as an endogenous decoy receptor in tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis of fibroblast-like synovial cells

We examined the role of osteoprotegerin (OPG) on tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in rheumatoid fibroblast-like synovial cells (FLS). OPG protein concentrations in synovial fluid from patients with rheumatoid arthritis (RA) correlated with those of interleukin (IL)-1beta or IL-6. A similar correlation was present between IL-1beta and IL-6 concentrations. Rheumatoid FLS in vitro expressed both death domain-containing receptors [death receptor 4 (DR4) and DR5] and decoy receptors [decoy receptor 1 (DcR1) and DcR2]. DR4 expression on FLS was weak compared with the expression of DR5, DcR1 and DcR2. Recombinant TRAIL (rTRAIL) rapidly induced apoptosis of FLS. DR5 as well as DR4 were functional with regard to TRAIL-mediated apoptosis induction in FLS; however, DR5 appeared be more efficient than DR4. In addition to soluble DR5 (sDR5) and sDR4, OPG administration significantly inhibited TRAIL-induced apoptogenic activity. OPG was identified in the culture supernatants of FLS, and its concentration increased significantly by the addition of IL-1beta in a time-dependent manner. Neither IL-6 nor tumour necrosis factor (TNF)-alpha increased the production of OPG from FLS. TRAIL-induced apoptogenic activity towards FLS was reduced when rTRAIL was added without exchanging the culture media, and this was particularly noticeable in the IL-1beta-stimulated FLS culture; however, the sensitivity of FLS to TRAIL-induced apoptosis itself was not changed by IL-1beta. Interestingly, neutralization of endogenous OPG by adding anti-OPG monoclonal antibody (MoAb) to FLS culture restored TRAIL-mediated apoptosis. Our data demonstrate that OPG is an endogenous decoy receptor for TRAIL-induced apoptosis of FLS. In addition, IL-1beta seems to promote the growth of rheumatoid synovial tissues through stimulation of OPG production, which interferes with TRAIL death signals in a competitive manner.

Bone marrow engraftment in a rodent model of chemical carcinogenesis but no role in the histogenesis of hepatocellular carcinoma

BACKGROUND AND AIM

Recent studies indicated that hepatic stem cells in the bone marrow could differentiate into mature hepatocytes, suggesting that bone marrow cells could be used for replacement of damaged hepatocytes in a variety of liver diseases. Hepatocellular carcinoma (HCC) is thought to arise from hepatic stem cells. In this study, we investigated the malignant potential of hepatic stem cells derived from the bone marrow in a mouse model of chemical hepatocarcinogenesis.

METHODS

Bone marrow cells were obtained from the male beta-galactosidase (beta-gal) transgenic mouse and transplanted into female recipient mice. Hepatocarcinogenesis was induced by a year of treatment with diethylnitrosamine and phenobarbital (NDEA/PB). One year later, the liver was removed from each treated mouse and evaluated by x-gal staining, immunohistochemistry, and fluorescence in situ hybridisation (FISH).

RESULTS

Forty per cent of recipient mice survived and developed multiple HCC. Clusters of beta-gal positive mature hepatocytes were detected sporadically in the entire liver of NDEA/PB treated mice who underwent bone marrow transplantation (BMT) with while no such hepatocytes were identified in the liver of BMT mice that were not treated with NDEA/PB. The Y chromosome was detected with the same frequency as the donor male liver in clusters of beta-gal positive mature hepatocytes by FISH. However, no HCC was positive for beta-gal or the Y chromosome. Immunohistochemically, beta-gal positive mature hepatocytes did not express CD34 or alpha-fetoprotein.

CONCLUSIONS

Our results suggest that hepatic stem cells derived from the bone marrow have low malignant potential, at least in our model.

Serum leptin level is a regulator of bone mass

Leptin is a powerful inhibitor of bone formation in vivo. This antiosteogenic function involves leptin binding to its receptors on ventromedial hypothalamic neurons, the autonomous nervous system and beta-adrenergic receptors on osteoblasts. However, the mechanisms whereby leptin controls the function of ventromedial hypothalamic antiosteogenic neurons remain unclear. In this study, we compared the ability of leptin to regulate body weight and bone mass and show that leptin antiosteogenic and anorexigenic functions are affected by similar amounts of leptin. Using a knock-in of LacZ in the leptin locus, we failed to detect any leptin synthesis in the central nervous system. However, increasing serum leptin level, even dramatically, reduced bone mass. Conversely, reducing serum-free leptin level by overexpressing a soluble receptor for leptin increased bone mass. Congruent with these results, the high bone mass of lipodystrophic mice could be corrected by restoring serum leptin level, suggesting that leptin is an adipocyte product both necessary and sufficient to control bone mass. Consistent with the high bone mass phenotype of lipodystrophic mice, we observed an advanced bone age, an indirect reflection of premature bone formation, in lipodystrophic patients. Taken together, these results indicate that adipocyte-derived circulating leptin is a determinant of bone formation and suggests that leptin antiosteogenic function is conserved in vertebrates.

Reduction of diet-induced obesity in transgenic mice overexpressing uncoupling protein 3 in skeletal muscle

AIMS/HYPOTHESIS

It has been suggested that uncoupling protein 3 (UCP3) can increase energy expenditure, thereby regulating body weight. Although studies on UCP3 knock-out mice suggest that lack of UCP3 function does not cause obesity or Type 2 diabetes, it is possible that up-regulation of UCP3 function improves these disorders or their clinical sequelae. A 10- to 20-fold increase of UCP3 gene expression is achievable through physiological or pharmacological stimuli. We examined the phenotype of transgenic mice with approximately 18-fold overexpression of mouse UCP3 mRNA in skeletal muscle.

METHODS

We generated transgenic mice with approximately 18-fold overexpression of mouse UCP3 mRNA in skeletal muscle under control of the skeletal muscle-specific muscle creatine kinase gene promoter. The phenotype of these mice was analysed either on a standard diet or on a 4-week high-fat diet.

RESULTS

In mice on standard chow, there was no difference in body weight, oxygen consumption and mitochondrial protonmotive force between transgenic mice and non-transgenic littermates. However, transgenic mice tended to have lower body weight, increased oxygen consumption and decreased mitochondrial protonmotive force than the control mice. Transgenic mice on a 4-week high-fat diet consumed much more oxygen and had noticeably less weight gain and less epididymal fat, as well as better glucose tolerance than non-transgenic littermates.

CONCLUSIONS/INTERPRETATION

Our study shows that 18-fold overexpression of UCP3 mRNA in the skeletal muscle reduced diet-induced obesity. An 18-fold increase of UCP3 mRNA can be attained by physiological or pharmacological stimuli, suggesting that UCP3 has therapeutic potential in the treatment of obesity.

Recombinant monoclonal thyrotropin-stimulation blocking antibody (TSBAb) established from peripheral lymphocytes of a hypothyroid patient with primary myxedema

Anti-TSH receptor antibodies (TRAbs) have been known to be involved in Graves' disease and primary hypothyroidism. We previously isolated and reconstituted immunoglobulin (Ig) genes of Epstein-Barr virus-transformed B cell clones producing monoclonal TRAbs obtained from Graves' patients. In the present study, we performed a similar experiment using a B cell clone, 32A-5, derived from a patient with primary hypothyroidism. The variable region genes of Ig heavy (H) and light (L) chains were isolated and sequenced from the 32A-5 clone. A significant number of somatic mutations were found in variable regions of H and L chain gene segments. Each pair of H and L chain cDNAs was ligated into an expression vector for IgG1 production and stably introduced into myeloma cells. The transfectants were injected ip into BALB/c mice to yield ample volume of the antibody for following applications. Interactions of recombinant 32A-5 with Graves' sera with varying thyroid-stimulating antibody (TSAb) activities were studied. The recombinant antibody tended to suppress TSAb activities in 10 of 15 Graves' sera, in which four were significantly inhibited. In summary, this is the first study to analyze human monoclonal TSH-stimulation blocking antibodies (TSBAb) at the molecular level. Use of human recombinant monoclonal TSBAb may be an analytical tool for molecular-basis etiology and an alternative therapeutic path for Graves' disease.