Micrometer-scale monolayer SnS growth by physical vapor deposition

Recently, monolayer SnS, a two-dimensional group IV monochalcogenide, was grown on a mica substrate at the micrometer-size scale by the simple physical vapor deposition (PVD), resulting in the successful demonstration of its in-plane room temperature ferroelectricity. However, the reason behind the monolayer growth remains unclear because it had been considered that the SnS growth inevitably results in a multilayer thickness due to the strong interlayer interaction arising from lone pair electrons. Here, we investigate the PVD growth of monolayer SnS from two different feed powders, highly purified SnS and commercial phase-impure SnS. Contrary to expectations, it is suggested that the mica substrate surface is modified by sulfur evaporated from the Sn2S3 contaminant in the as-purchased powder and the lateral growth of monolayer SnS is facilitated due to the enhanced surface diffusion of SnS precursor molecules, unlike the growth from the highly purified powder. This insight provides a guide to identify further controllable growth conditions.

Efficacy of cardiac rehabilitation with motion assistance from wearable cyborg hybrid assistive limb in patients with chronic heart failure: a randomized controlled trial

Background

Recent Cochrane Systematic Review suggested that the participation in cardiac rehabilitation is associated with approximately 20% lower cardiovascular mortality and morbidity. Exercise therapy is the key component of cardiac rehabilitation programs. In recent years, innovative technologies have been introduced into the field of rehabilitation, and a typical example is the wearable cyborg Hybrid Assistive Limb (HAL). The wearable cyborg HAL provides motion assistance based on detection of bioelectrical signals on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in performing usual cardiac rehabilitation programs, such as bicycle pedaling or walking.

Purpose

We aim to compare the efficacy of exercise therapy performed with motion assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure.

Methods

This clinical trial is a randomized, non-blinded, and controlled study. Twenty-eight heart failure patients (73.1±13.8 years) who have difficulty in walking at the usual walking speed of healthy subjects were randomly assigned to 2 groups (HAL group or control group) with a 1:1 allocation ratio and performed sit-to stand exercise either with HAL or without HAL for 5 to 30 minutes once a day, and 6 to 10 days during the study period. The brain natriuretic peptide (BNP), isometric knee extensor strength, standing ability (30-seconds chair-stand test: CS-30), short physical performance battery (SPPB) and 6-minute walking distance (6MWD) were measured before and after the completion of cardiac rehabilitation. Cardiac events such as death, re-hospitalization, myocardial infarction and worsening of angina pectoris and heart failure during 1 year after discharge were evaluated.

Results

There was no significant difference in the number of days of exercise therapy between the two groups. BNP, SPPB and 6MWD were improved in both groups. In the HAL group, the isometric knee extensor strength (0.29±0.11 vs 0.35±0.11 kgf/kg, p=0.003) significantly improved and CS-30 (5.5±5.1 vs 8.2±5.3, p=0.054) tended to improve. However, in the control group, either the isometric knee extensor strength (0.35±0.11 vs 0.36±0.14 kgf/kg, p=0.424) or CS-30 (6.0±4.3 vs 9.2±6.2, p=0.075) did not significantly change. HAL group showed significantly more improvement in the isometric knee extensor strength than control group (p=0.045). Cardiac events occurred in 20% in the HAL group and 43% in the control group.

Conclusion

The improvement in isometric knee extensor strength with the assistance from lumbar-type HAL suggests that exercise therapy using this device may be useful in chronic heart failure patients with flail or sarcopenia, a strong poor prognostic factor in these patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (JSPS KAKENHI grant number JP17K09485) and funded by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) (grant number 2017-PM05-03-01).

P6530Clinical outcomes of dialysis patients treated with current generation DES for left main distal bifurcation

Objectives

We assessed clinical outcomes after percutaneous coronary intervention (PCI) for unprotected left main (ULM) using current generation drug eluting stents (cDES) in hemodialysis (HD) patients compared to general populations.

Methods

We identified 1269 consecutive patients who underwent PCI for ULM distal bifurcation lesions. Of them, 563 patients were treated with cDES (512 non HD and 51 HD patients). The primary endpoint was target lesion failure (TLF) at 3 years, defined as a composite of cardiac death, target lesion revascularization (TLR) and myocardial infarction (MI).

Results

HD group was more likely to have diabetes mellitus (70.0% vs. 45.8%, p=0.002), peripheral artery disease (56.0% vs. 14.9%, p<0.001), and lower ejection fraction (52.6% vs. 56.3%, p=0.026). The rate of TLF at 3 years was significantly higher in the HD group (adjusted Hazard ratio [HR] 2.59; 95% confidence interval [CI], 1.54–4.37; p<0.001). Cardiac mortality was significantly higher in the HD group (adjusted HR 4.49; 95% CI, 2.07–9.74; p<0.001). The rates of TLR for LM-left anterior descending artery (LAD) and left circumflex ostium (LCXos) were significantly higher in the HD group (LMT-LAD: adjusted HR 3.10; 95% CI, 1.31–7.33; p=0.01, LCXos: adjusted HR 2.56; 95% CI, 1.32–4.94; p=0.005). The rate of MI was similar between the 2 groups.

Conclusions

Hemodialysis was strongly associated with adverse events after PCI for ULM distal bifurcation lesions even with cDES.

A case of combined laparoscopic reduction and open preperitoneal mesh repair for incarcerated small bowel in a retroperitoneal hernia between the external and internal iliac vessels

We report a rare case of an incarcerated retroperitoneal hernia with or involving the small bowel through the orifice between the right external and internal iliac vessels. A 39-year-old woman was admitted to our hospital because of vomiting and abdominal pain. She had a history of right oophorocystectomy and appendectomy. Abdominal computed tomography revealed small bowel obstruction resulting from an incarcerated retroperitoneal hernia. The small bowel herniated into the retroperitoneal fossa through the orifice between the right external and internal iliac vessels. Laparoscopic reduction of the small bowel was performed, followed by ligation of the sac and placement of a mesh prosthesis through the preperitoneal approach, using a lower midline incision along the previous laparotomy scar. Her postoperative course was uneventful and no recurrence has been observed after surgery.

Development of an MR-compatible configurable brush stimulation device

In order to evaluate sensory disturbance, a subjective method is performed, so that the evaluation result is influenced by subjective factors. fMRI is used for observing brain activity objectively. Therefore the brain response to a stimulation measured by fMRI could become a useful identification tool for the objective evaluation of the sensory disturbance. The purpose of this study is to develop an MR-compatible sensory stimulation device capable of providing brush stimulation to several positions with separate modules, and to confirm the feasibility of the device by a basic operation experiment and an fMRI experiment. The developed device consists of both an MR-compatible stimulator placed inside the MRI room, a tube-rod mechanism and a driver placed outside the MRI room. The tube-rod mechanism is adopted for power transmission from the driver to the stimulator. Also, in order to provide the stimulation to several positions in the limited space, the device consists of the stimulation module and the positioning module that moves the stimulation module. For the basic operation experiment, we measure a variation of the automated and manual brush stimulation period. For the fMRI experiment, the brush stimulation is provided to the middle fingertip and the palm of a subject in a trial using the developed device. As a result, the standard deviations of the automated brush stimulation period is less than 7.0 ms. This result was smaller than that of the manual stimulation period. Also, the brush stimulation to the fingertip and the palm activated the somatosensory areas respectively. In conclusion, we confirmed the feasibility of the developed device through the experiments.

High-dose chemotherapy for high-risk retinoblastoma: clinical course and outcome of 14 cases in the National Cancer Center, Japan

The prognosis of high-risk retinoblastoma (RB) with extraocular disease, relapse, or invasion of the cut end of the optic nerve is extremely poor. Following the discontinuation of thiotepa production in Japan, BU- and melphalan (Mel)-based regimens have been used, followed by the standard treatment for neuroblastoma. This study retrospectively analyzed 14 high-risk RB patients who underwent high-dose chemotherapy (HDC) and hematopoietic SCT; 8 received a BU/Mel conditioning regimen and 6 received other regimens. The disease status at HDC was relapse in 8 patients and extraocular involvement in 5. All patients received peripheral blood stem cell infusion >1.5 × 10(6)/kg. Engraftment occurred within a median of 11 days (BU/Mel: 10-13, others: 9-13). Primary toxicities included mucositis (⩾grade 3) in 9 patients (4 with BU/Mel, 5 with others). Veno-occlusive disease (VOD) occurred in two 1-year-old patients in the BU/Mel group. There were no treatment-related deaths. Of 4 (2 with BU/Mel, 2 with others) patients with central nervous system (CNS) relapse after HDC, 3 died. In conclusion, the BU/Mel regimen may be feasible for high-risk RB under careful monitoring for VOD, particularly in younger patients. CNS relapse associated with a lethal prognosis occurred after all regimens; therefore, further evaluation of HDC efficacy for high-risk RB is required.

Development of Canine Models of Type 1 Diabetes With Partial Pancreatectomy and the Administration of Streptozotocin

We created canine models of type 1 diabetes that were suitable for the assessment of cell therapies, such as islet transplantation and bioartificial pancreas, with low-dose streptozotocin (STZ) injection and partial pancreatectomy. In our model, a 50% pancreatectomy was performed with general anesthesia, followed by systemic injection of 35 mg/kg STZ into a vein of the foreleg. Four weeks after the administration of STZ, the fasting blood glucose level of our model dogs was found to be over 200 mg/dl twice on different days, and we could not detect any canine insulin by the intravenous glucose tolerance test (IVGTT). We therefore diagnosed the dogs to have induced diabetes. Some studies have reported high-dose STZ to be very toxic for both the kidney and liver, and therefore a lower dose is desirable to induce diabetic models without any associated kidney or liver damage. We think that the combination of a partial pancreatectomy can thus make it possible to reduce the dose of STZ, and it is therefore useful for the creation of type 1 diabetes models. We believe that our model is a safe and reliable model for type 1 diabetes in canines to assess the efficacy of pancreas-targeted cell therapies.

Establishment of an immortalized porcine liver cell line JSNK-1 with retroviral transduction of SV40T

Maintenance of freshly isolated porcine liver cells in vitro is limited for a short period of time. Therefore, establishment of easy handling cell lines is extremely important for in vitro study for liver cells and their possible utilization for cell differentiation and growth of stem cells. Porcine liver cells were transduced with a retroviral vector SSR#69 expressing SV40T, one of SSR#69-immortalized porcine liver cell lines, JSNK-1, was established and characterized. Morphology of JSNK-1 cells was spindle shaped. When the cells became confluent, JSNK-1 cells revealed hills-and-valleys pattern. In the presence of vitamin A, JSNK-1 cells showed big droplets inside the cytoplasm, which were positive with PAS staining. JSNK-1 cells showed the gene expression of collagen type 1α1, collagen type 1α2, FLT-1, β-actin, and SV40T. Immunostaining study revealed that JSNK-1 cells produced collagen, vimentin, and α-smooth muscle actin. JSNK-1 cells possessed the characteristics of the liver stellate cells. JSNK-1 cells produced hepatocyte growth factor (HGF) in a time-dependent manner. When cocultured with iPS cells towards the hepatic differentiation, JSNK-1 cells facilitated their hepatic differentiation in terms of albumin production. In conclusion, JSNK-1 cells would be valuable in the study of liver stellate cell pathophysiology and contribute to the optimization of hepatic differentiation of iPS cells.

Hepatic differentiation of mouse iPS cells in vitro

Induced pluripotent stem (iPS) cells are pluripotent and are able to unlimitedly proliferate in vitro. This technical breakthrough in creating iPS cells from somatic cells has noteworthy implications for overcoming the immunological rejection and the ethical issues associated with the derivation of embryonic stem cells from embryos. In the current work, we present an efficient hepatic differentiation of mouse iPS cells in vitro. iPS cells were cultured free floating to induce the formation of embryoid bodies (EB) for 5 days. EB were transferred to a gelatin-coated plate and treated with 100 ng/ml activin A and 100 ng/ml basic fibroblast growth factor (bFGF) for 3 days to induce definitive endoderm. Cells were further cultured for 8 days with 100 ng/ml hepatocyte growth factor (HGF) to generate hepatocytes. Characterization was performed by RT-PCR assay. Functional analysis for albumin secretion and ammonia removal was also carried out. iPS cell-derived hepatocyte-like cells (iPS-Heps) were obtained at the end of the differentiation program. Expression levels of a gestational hepatocyte gene and lineage-specific hepatic genes intensified in iPS-Heps. The production of albumin increased in a time-dependent manner. iPS-Heps were capable of metabolizing ammonia. We present here instant hepatic differentiation of mouse iPS cells using combined 3-day treatments of activin A and bFGF with subsequent 8-day HGF. Our study will be an important step to generate hepatocytes from human iPS cells as a new source for liver-targeted cell therapies.

Characteristics of CD133(+) human colon cancer SW620 cells

Worldwide, colorectal cancer is the third most common type of cancer affecting both sexes. It has been proposed that a small subset of cancer cells (cancer stem cells) within each tumor is able to initiate tumor growth. In 2007, two research groups simultaneously identified a colon cancer stem cell population in human tumors by the use of CD133 expression. In the present study, we used a human colon cancer cell line, SW620, to analyze the cancer stem cell-like characteristics of CD133(+) cells in vitro and in vivo. In vitro, CD133(+) SW620 cells had a higher proliferative capacity, were more irradiation- and chemotherapy-resistant, and had a higher expression of β-catenin compared with CD133(-) cells. Injections of either CD133(+) or CD133(-) cells into the skin or rectal mucosa of NOD/SCID mice led to tumors; however, injection of CD133(+) cells resulted in the formation of larger tumors. Tumors derived from injections of CD133(-) cells did not contain any CD133(+) cells, whereas tumors derived from injections of CD133(+) cells did contain CD133(+) cells, suggesting self-renewing capability. However, the proportion of CD133(+) cells in the newly formed tumors in vivo was lower than the proportion of CD133(+) cells in vitro. In conclusion, the human colon cancer cell line, SW620, contains both CD133(+) and CD133(-) phenotypes, and the CD133(+) phenotype has characteristics consistent with those of cancer stem cells.

Isolation and propagation of a human CD133(-) colon tumor-derived cell line with tumorigenic and angiogenic properties

It has been proposed in human colorectal cancers (CRC) a minority subset of cancer cells within tumors able to initiate tumor growth, defined as cancer stem cells (CSC). Solid human primary colonic and its ovarian metastatic cancer tissues were collected from fresh surgical samples and subsequent xenografts were established in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. The resulting tumors were disaggregated into single-cell suspensions and a CD133(-) cell line (NANK) was newly established and analyzed by flow cytometry. Surface markers of progenitor cells were immunophenotypically analyzed, and expression of stem cell and cancer-related genes was characterized. Secreted angiogenesis-associated molecules were investigated by proteomic array technology. Finally, different numbers of NANK were implanted and their tumor-initiating properties were investigated in NOD/SCID mice. Intraperitoneal injection of NANK in NOD/SCID mice induced tumors with developing progressive peritoneal dissemination and ascites. NANK cells maintained a differentiated phenotype and reproduced the full morphologic and phenotypic heterogeneity of their parental lesions. Noticeably, NANK lacked the expression of conventional CSC markers CD133 and CD44, self-renewal genes Oct-4 and Nanog, but showed the expression of an important gastrointestinal development marker CDX-2 and BMI-1 that is essential in regulating the proliferative activity of normal and leukemic stem cells. In addition, NANK secreted high amounts of important angiogenic cytokines. These results provide a novel and extensive model in human CSC for studying the generation and maintenance of phenotypic heterogeneity in CRC.

Characteristics of CD133(+) human colon cancer SW620 cells

Worldwide, colorectal cancer is the third most common type of cancer affecting both sexes. It has been proposed that a small subset of cancer cells (cancer stem cells) within each tumor is able to initiate tumor growth. In 2007, two research groups simultaneously identified a colon cancer stem cell population in human tumors by the use of CD133 expression. In the present study, we used a human colon cancer cell line, SW620, to analyze the cancer stem cell-like characteristics of CD133(+) cells in vitro and in vivo. In vitro, CD133(+) SW620 cells had a higher proliferative capacity, were more irradiation- and chemotherapy-resistant, and had a higher expression of β-catenin compared with CD133(-) cells. Injections of either CD133(+) or CD133(-) cells into the skin or rectal mucosa of NOD/SCID mice led to tumors; however, injection of CD133(+) cells resulted in the formation of larger tumors. Tumors derived from injections of CD133(-) cells did not contain any CD133(+) cells, whereas tumors derived from injections of CD133(+) cells did contain CD133(+) cells, suggesting self-renewing capability. However, the proportion of CD133(+) cells in the newly formed tumors in vivo was lower than the proportion of CD133(+) cells in vitro. In conclusion, the human colon cancer cell line, SW620, contains both CD133(+) and CD133(-) phenotypes, and the CD133(+) phenotype has characteristics consistent with those of cancer stem cells.

Treatment of acute liver failure in mice by hepatocyte xenotransplantation

Liver diseases still have a high mortality even though liver transplantation has become a standard treatment. Currently, hepatocyte transplantation has been proposed as another promising strategy. One limitation is the availability of human livers as a source of hepatocytes. Because of an unlimited supply, the use of porcine hepatocytes might address this problem. Regardless of the source, once isolated hepatocytes lose specific functionality due to the loss of the natural microenvironment. For this reason, we tested the ability of a self-assembling peptide nanofiber (SAPNF) to provide a provisional three-dimensional (3D) support to interact with cells to control their function in vivo. Isolated porcine hepatocytes were embedded in SAPNF, or collagen type I and transplanted by direct injection into the splenic pulp of SCID mice suffering from acute liver failure (ALF) by 90% hepatectomy. SAPNF porcine hepatocyte transplantation produced engraftment that was far superior to that obtained using collagen and prolonged the survival of mice with ALF, in contrast with controls. An ultrastructural evaluation using transmission electron microscopy indicated extensive cell-cell communication and preservation of hepatocyte architecture. The transplanted SAPNF hepatocytes showed higher expression of albumin and PAS and lower apoptotic events assessed by TUNEL staining. Hepatocytes culture in a truly 3D network allows in vivo maintaining of differentiated functions, and once transplanted between widely divergent species can function to correct acute liver failure in mice and prolong their survival.

Comparative Analysis of Endoderm Formation Efficiency between Mouse ES Cells and iPS Cells

Definitive endoderm (DE) derived from stem cells holds potential to differentiate into hepatocytes. Stem cell therapy using those cells has potential for a treatment of liver disease. To date, various ways of inducing hepatocytes from embryonic stem (ES) cells have been reported by researchers. However, it has not been proved enough that induced pluripotent stem (iPS) cells behave in the same manner as ES cells in endoderm differentiation. The purpose of this study was to establish an efficient method to induce DE from iPS cells, through comparatively analyzing the efficacy of endoderm formation from mouse ES cells. Furthermore, the efficiency of a serum-free medium in the differentiation into DE was investigated. Mouse ES cells and iPS cells were floated in culture medium for 2 or 5 days and embryoid bodies (EB) were formed. Subsequently, DE was induced with 100 ng/ml activin A and 100 ng/ml basic fibroblast growth factor (bFGF). RT-PCR and real-time PCR analyses were carried out at each step to determine the gene expression of EB markers. The difference in cellular proliferation between serum-containing and serum-free media was examined by an MTS assay in EB and DE induction. iPS cells showed the paralleled mRNA expression to ES cells in each step of differentiation into EB, but the levels of expression of Sox17 and Foxa2 were relatively higher in ES cell-derived DE, whereas Cxcr4 expression was higher in iPS cell-derived DE. The utilization of serum-free medium for iPS cells showed significantly favorable cellular proliferation during EB formation and subsequent DE induction. Forming EB for 5 days and subsequently DE induction with activin A and bFGF with serum-free medium was an appropriate protocol in iPS cells. This may represent an important step for generating hepatocytes from iPS cells for the development of cell therapy.

Bone repair by transplantation of hTERT-immortalized human mesenchymal stem cells in mice

BACKGROUND

Human mesenchymal stem cells (hMSCs) are multipotent stem cells found in the adult bone marrow that have the capacity to differentiate into various mesenchymal cell types. The hMSCs may provide a potential therapy to restore damaged tissues or organs of mesenchymal origin; however, a drawback is their limited life span in vitro.

METHODS

We immortalized normal hMSCs with retrovirally transmitted human telomerase reverse transcriptase cDNA. One of the immortalized clones (YKNK-12) was established, and the biological characteristics were investigated in vitro and in vivo.

RESULTS

YKNK-12 cells were capable of differentiating adipocytes, osetoblasts, and chondrocytes. Osteogenically differentiated YKNK-12 cells produced significant levels of growth factors BMP4, BMP6, FGF6, FGF7, transforming growth factor-beta1, and transforming growth factor-beta3.. Microcomputer tomography T and soft X-ray assays showed an excellent calvarial bone healing in mice after transplantation of osteogenically differentiated YKNK-12 cells. These cells expressed human-specific osteocalcin and increased the gene expression of runt-related transcription factor 2, alkaline phosphatase, osteocalcin, and osterix in the bone regenerating area. YKNK-12 cell transplant corrected the bone defect without inducing any adverse effects.

CONCLUSIONS

We conclude that hMSCs immortalized by transduction with human telomerase reverse transcriptase may provide an unlimited source of cells for therapeutic use in bone regeneration.

Cancer stem cell research: current situation and problems

The concept of a "cancer stem cell system" that continues to supply cancer component cells has been proposed. It is time to apply stem cell studies, which is a field of expertise in regenerative medicine, to cancer treatment. Cancer treatments that effectively attack cancer stem cells acting as a manufacturing plant for producing differentiated cancer progenies will be designed by revealing the cancer stem cell system. Therefore, in the near future we hope that revolution will occur in cancer therapy to eradicate cancer and prevent the recurrence thereof. In this review we discuss the current situation and problems of cancer stem cell research.

Interobserver agreement in endoscopic evaluation of reflux esophagitis using a modified Los Angeles classification incorporating grades N and M: a validation study in a cohort of Japanese endoscopists

The Los Angeles classification system is the most widely employed criteria associated with the greatest interobserver agreement among endoscopists. In Japan, the Los Angeles classification system has been modified (modified LA system) to include minimal changes as a distinct grade of reflux esophagitis, rather than as auxiliary findings. This adds a further grading M defined as minimal changes to the mucosa, such as erythema and/or whitish turbidity. The modified LA system has come to be used widely in Japan. However, there have been few reports to date that have evaluated the interobserver agreement in diagnosis when using the modified LA classification system incorporating these minimal changes as an additional grade. A total of 100 endoscopists from university hospitals and community hospitals, as well as private practices in the Osaka-Kobe area participated in the study. A total of 30 video clips of 30-40 seconds duration, mostly showing the esophagocardiac junction, were created and shown to 100 endoscopists using a video projector. The participating endoscopists completed a questionnaire regarding their clinical experience and rated the reflux esophagitis as shown in the video clips using the modified LA classification system. Agreement was assessed employing kappa (kappa) statistics for multiple raters. The kappa-value for all 91 endoscopists was 0.094, with a standard error of 0.002, indicating poor interobserver agreement. The endoscopists showed the best agreement on diagnosing grade A esophagitis (0.167), and the poorest agreement when diagnosing grade M esophagitis (0.033). The kappa-values for the diagnoses of grades N, M, and A esophagitis on identical video pairs were 0.275-0.315, with a standard error of 0.083-0.091, indicating fair intraobserver reproducibility among the endoscopists. The study results consistently indicate poor agreement regarding diagnoses as well as fair reproducibility of these diagnoses by endoscopists using the modified LA classification system, regardless of age, type of practice, past endoscopic experience, or current workload. However, grade M reflux esophagitis may not necessarily be irrelevant, as it may suggest an early form of reflux disease or an entirely new form of reflux esophagitis. Further research is required to elucidate the pathophysiological basis of minimal change esophagitis.

Aspirin: recent developments

Aspirin exerts anti-thrombotic action by acetylating and inactivating cyclooxygenase-1, preventing the production of thromboxane A2 in platelets. Through this inhibition of platelet function, aspirin is considered as a preventative of ischemic diseases such as coronary and cerebral infarction. However, many studies have revealed that aspirin has other beneficial actions in addition to its anti-platelet activity. For example, aspirin may confer some benefit against colorectal cancer. Here, we discuss the involvement of inflammation in atherosclerosis and how aspirin exerts its beneficial actions in atherosclerotic diseases and cancer.

Therapeutic efficacy of leukocytapheresis in a pregnant woman with severe active ulcerative colitis

Leukocytapheresis has recently been used to induce remission in patients with ulcerative colitis (UC) who fail to respond to corticosteroids. We could not find a report in the literature on leukocytapheresis for UC with gestational exacerbation. We have recently encountered this unique condition and report the details here. A 30-year-old Japanese woman with left-sided severe UC was corticosteroid-dependent and had recurrence of the active disease during tapering of corticosteroid. She declined any dose increase and the use of any immunosuppressive agent because she was in the 13th week of pregnancy. Then, concomitant leukocytapheresis was performed without increasing the corticosteroid dose. Recovery was rapid and dramatic. Mucous and bloody stool decreased after the first session, and she had remission 2 weeks later. She underwent a total of four sessions without complications. After 6 weeks, she was discharged from our hospital and underwent maintenance treatment as an outpatient with mesalazine and corticosteroid tapering. Subsequently, she gave birth to a healthy baby girl by an uncomplicated vaginal delivery while keeping the remitted stage of UC.

Clinical characteristics of synchronous colorectal cancer are different according to tumour location

AIMS

The purpose of this study was to investigate the clinical characteristics of synchronous cancer patients, with particular attention given to variations in tumour location.

METHODS

A retrospective evaluation of 249 synchronous cancer cases out of 3061 consecutive colorectal cancer patients.

RESULTS

Multivariate analysis of risk factors for synchronous cancer according to tumour location revealed that male gender was a significant risk for synchronous lesions in the left colon only (odds ratio=2.05, 95% confidence interval 1.34-3.13). Meanwhile, aging was a risk factor for synchronous cancer in the right colon only (odds ratio=1.05, 95% confidence interval 1.02-1.08), and in both sides of the colon (odds ratio=1.03, 95% confidence interval 1.01-1.05), but not in the left colon only (odds ratio=0.98, 95% confidence interval 0.97-1.00). In addition, patients with synchronous lesions in the right colon only tended to have adenomas in the right colon, while those with synchronous lesions in the left colon only tended to have adenomas in the left colon (each P value <0.05).

CONCLUSION

The risk factors and status of concurrent adenomas of synchronous cancer cases varied according to tumour location, suggesting that the colonic site susceptible to neoplasia varies according to patient characteristics.

Muscle type-specific response of PGC-1 alpha and oxidative enzymes during voluntary wheel running in mouse skeletal muscle

AIM

It is generally accepted that endurance exercise increases the expression of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha), which governs the expression of oxidative metabolic enzymes. A previous report demonstrated that the regulation of mitochondrial protein expression in skeletal muscles in response to cold exposure depends on muscle fibre type. Cold exposure and endurance exercise are both metabolic challenges that require adjustments in mitochondrial energy metabolism, we hypothesized that the exercise-induced increase in oxidative enzymes and PGC-1alpha expression is higher in fast-type than in slow-type muscle.

METHODS

Female ICR mice were individually housed in cages equipped with running wheel for 1, 2, 4, 6 or 8 weeks. The soleus, plantaris (PLA) and tibialis anterior (TA) muscles were then prepared from each mouse. The expression levels of PGC-1alpha, mitochondrial proteins and GLUT4 were evaluated by Western blotting.

RESULTS

The expression level of PGC-1alpha was increased only in the PLA muscle. Furthermore, the expression levels of all mitochondrial proteins and GLUT4 in the PLA muscle were increased. In the TA muscle, although there was no increase in PGC-1alpha expression, the expression levels of mitochondrial proteins and GLUT4 were increased.

CONCLUSIONS

These results suggest that muscle type-specific responses occur during endurance exercise, and that the increase in PGC-1alpha expression is not the only factor that promotes oxidative capacity as a result of endurance exercise.

Endoscopic submucosal dissection for early gastric cancer: results and degrees of technical difficulty as well as success

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) is a new method for the curative treatment of early gastrointestinal neoplasms, which was developed in order to increase the en bloc and R0 resection rate, especially for lesions larger than 20 mm in diameter. Drawbacks of ESD include the fact that it is technically a substantially more difficult procedure and that it is associated with a higher perforation rate. A retrospective study was therefore carried out to analyze cases in relation to the procedure time and resection success, and these factors were correlated with the characteristics of the lesions.

PATIENTS AND METHODS

From January 2002 to November 2005, 196 lesions in 185 patients with early gastric cancer were treated using ESD in our hospital. The rates of curative en bloc resection, the incidence of perforation, and the procedure times were analyzed in relation to lesion size (small, 20 mm or less in diameter; large, over 20 mm), location (upper, middle, or lower third of the stomach) and the presence or absence of ulceration.

RESULTS

The rate of curative en bloc resection was 84 % (93 % of the lesions overall were resected in one piece), with a perforation rate of 6.1 % (all perforations were managed endoscopically) and a mean procedure time of 68 min. The rate of curative en bloc resection differed significantly depending on the location of the lesion (upper vs. middle vs. lower, 74 % vs. 77 % vs. 91 %; P < 0.05), as well as on the size of the lesion (> 20 mm vs. 20 mm or less, 59 % vs. 89 %; P < 0.0001). There were also significant differences in the mean procedure times in relation to the location of the lesion (upper vs. middle vs. lower, 105 min vs. 81 min vs. 45 min; P < 0.0001) and the size of the lesion (> 20 mm vs. 20 mm or less, 124 min vs. 55 min; P < 0.0001), as well as the presence of ulceration (positive vs. negative, 97 min vs. 65 min; P < 0.05). With regard to perforation rates, significant differences were also observed in relation to the location of the lesion (upper vs. middle vs. lower, 22.6 % vs. 2.8 % vs. 3.2 %; P < 0.0005) and size of the lesion (> 20 mm vs. 20 mm or less, 16.2 % vs. 3.8 %; P < 0.005). No local recurrences of curatively resected lesions (n = 119) were observed after a follow-up period of 1 year.

CONCLUSIONS

The difficulty of ESD depends on the location and size of the lesion, as well as on the presence of ulceration. We would recommend that trainees should begin by carrying out ESD on lesions with a diameter of less than 20 mm without ulceration that are located in the lower third of the stomach.

Endoscopic submucosal dissection for early gastric cancer: results and degrees of technical difficulty as well as success

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) is a new method for the curative treatment of early gastrointestinal neoplasms, which was developed in order to increase the en bloc and R0 resection rate, especially for lesions larger than 20 mm in diameter. Drawbacks of ESD include the fact that it is technically a substantially more difficult procedure and that it is associated with a higher perforation rate. A retrospective study was therefore carried out to analyze cases in relation to the procedure time and resection success, and these factors were correlated with the characteristics of the lesions.

PATIENTS AND METHODS

From January 2002 to November 2005, 196 lesions in 185 patients with early gastric cancer were treated using ESD in our hospital. The rates of curative en bloc resection, the incidence of perforation, and the procedure times were analyzed in relation to lesion size (small, 20 mm or less in diameter; large, over 20 mm), location (upper, middle, or lower third of the stomach) and the presence or absence of ulceration.

RESULTS

The rate of curative en bloc resection was 84 % (93 % of the lesions overall were resected in one piece), with a perforation rate of 6.1 % (all perforations were managed endoscopically) and a mean procedure time of 68 min. The rate of curative en bloc resection differed significantly depending on the location of the lesion (upper vs. middle vs. lower, 74 % vs. 77 % vs. 91 %; P < 0.05), as well as on the size of the lesion (> 20 mm vs. 20 mm or less, 59 % vs. 89 %; P < 0.0001). There were also significant differences in the mean procedure times in relation to the location of the lesion (upper vs. middle vs. lower, 105 min vs. 81 min vs. 45 min; P < 0.0001) and the size of the lesion (> 20 mm vs. 20 mm or less, 124 min vs. 55 min; P < 0.0001), as well as the presence of ulceration (positive vs. negative, 97 min vs. 65 min; P < 0.05). With regard to perforation rates, significant differences were also observed in relation to the location of the lesion (upper vs. middle vs. lower, 22.6 % vs. 2.8 % vs. 3.2 %; P < 0.0005) and size of the lesion (> 20 mm vs. 20 mm or less, 16.2 % vs. 3.8 %; P < 0.005). No local recurrences of curatively resected lesions (n = 119) were observed after a follow-up period of 1 year.

CONCLUSIONS

The difficulty of ESD depends on the location and size of the lesion, as well as on the presence of ulceration. We would recommend that trainees should begin by carrying out ESD on lesions with a diameter of less than 20 mm without ulceration that are located in the lower third of the stomach.

Clinical utility of FDG-PET for evaluation of the viability in post-chemotherapeutic residual lesions in pediatric solid tumors

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Background: Exact evaluation of viability in post-chemotherapeutic residual lesions in patients with solid tumors should allow us to select the appropriate therapeutic options. F-18 fluorodeoxyglucose position emission tomography (FDG-PET) is one of the promising modality to evaluate it without invasive procedure. Methods: The cohort is a total of 14 patients with pediatric solid tumors (rhabdomyosarcoma 7, Ewing sarcoma 4, Wilms tumor 2 and neuroblastoma 1), which are either newly diagnosed or newly relapsed between January 2005 and December 2005. A total of 15 residual tumors from the 14 patients after chemotherapy underwent 51 FDG-PET scans. Seven residual tumors out of 6 patients, who were newly diagnosed, and another 8 tumors out of 8 patients, who were relapsed, were evaluated after induction or reinduction chemotherapy. Parameters of FDG-PET were assessed by area of FDG uptake and standardized uptake values (SUV). Results of FDG-PET were compared either with histological examination of the residual tumors (n=11) or with the clinical status 6-month after the last FDG-PET (n=4) in order to judge whether the findings of FDG-PET were true or false. Results: Three of 15 residual lesions showed increased SUV, while 12 lesions obtained negative SUV. Three lesions with positive SUV consisted of 2 true-positive and 1 false-positive lesions. Among twelve lesions were negative SUV, 11 lesions were true-negative, and 1 was false-negative. The sensitivity and specificity of FDG-PET in predicting the viability of residual lesions were 66% and 91%, respectively. A lesion of rhabdomyosarcoma which obtained negative SUV in FDG-PET histological showed viable cells. A lesion of another rhabdomyosarcoma which showed positive SUV was evaluated as inflammatory lesion. Conclusions: Although FDG-PET showed excellent sensitivity and fair specificity in predicting the viability of residual lesions in patients with pediatric solid tumors, possibility of false-negativity should give us a caution not to rely on FDG-PET to judge the termination of therapy.

No significant financial relationships to disclose.

Prognosis of small thyroid cancer in patients with Graves' disease

Background

To find the best ways to follow up patients with small thyroid cancer (STC; 1 cm or less in diameter) and concomitant Graves' disease, this study examined whether such patients had the same excellent prognosis as those with STC without Graves' disease.

Methods

Between 1970 and 1996, 2199 patients were diagnosed as having STC by pathology after thyroidectomy. Of those, 509 patients (33 males and 476 females, mean age 43·5 years) underwent thyroidectomy for Graves' disease. Control patients with STC without Graves' disease were matched for age, sex, treatment year and tumour size (33 males and 476 females, mean age 44·0 years).

Results

Patients with STC and Graves' disease had a longer disease-free survival than those with STC alone (99 and 93 per cent at 20 years' follow-up, respectively; P &lt; 0·001). The Cox's proportional hazard analysis showed that concomitant Graves' disease and age at surgery are more significant factors for predicting disease-free survival than surgical procedures.

Conclusion

Patients who undergo thyroidectomy for Graves' disease and are found to have STC have an excellent prognosis and longer disease-free survival than patients with STC alone.