Analysis of rapid increase in the plasma density during the ramp-up phase in a radio frequency negative ion source by large-scale particle simulation

Numerical simulations become useful for the developing RF-ICP (Radio Frequency Inductively Coupled Plasma) negative ion sources. We are developing and parallelizing a two-dimensional three velocity electromagnetic Particle-In-Cell code. The result shows rapid increase in the electron density during the density ramp-up phase. A radial electric field due to the space charge is produced with increase in the electron density and the electron transport in the radial direction is suppressed. As a result, electrons stay for a long period in the region where the inductive electric field is strong, and this leads efficient electron acceleration and a rapid increasing of the electron density.

Applicability of ultrasound muscle thickness measurements for predicting fat-free mass in elderly population

OBJECTIVE

This study aimed to examine the applicability of ultrasound muscle thickness (MT) measurements for predicting whole body fat-free mass (FFM) in elderly individuals.

DESIGN AND SETTING

Cross-sectional study of 77 healthy elderly individuals.

METHODS

MTs at nine sites of the body and FFM were determined using B-mode ultrasound and dual-energy x-ray absorptiometry (DXA), respectively, in 44 women and 33 men aged 52 to 78 yrs. Stepwise multiple regression analysis produced two equations for predicting DXA-based FFM with sex (dummy: woman = 0 and man = 1) and either MTs at the anterior and posterior of thigh and lower leg (Eq1) or the product of MT and limb length (MT×LL) at thigh anterior and posterior, lower leg posterior, and upper arm anterior (Eq2) as independent variables.

RESULTS

The R2 and SEE for each of the two equations were 0.929 and 2.5 kg for Eq1 and 0.955 and 2.0 kg for Eq2. The estimated FFM from each of Eq1 (44.4 ± 8.9 kg) and Eq2 (44.4 ± 9.0 kg) did not significantly differ from that of the DXA-based FFM (44.4 ± 9.2 kg), without systematic error. However, the absolute value of the difference between the DXA-based and estimated FFM was significantly greater with Eq1 (2.0 ± 1.5 kg) than with Eq2 (1.5 ± 1.3 kg).

CONCLUSION

The current results indicate that ultrasound MT measurement is useful to predict FFM in the elderly, and its accuracy is improved by using the product of MT and limb length as an independent variable.

[Two cases of acute large bowel obstruction caused by advanced cancer treated with stenting "bridge to surgery" procedure]

Obstructive colorectal cancer accounts for 3.1-15.8% of total colorectal cancer cases, therefore it is not a rare condition. Formerly, it has been often treated with emergent operation such as colostomy or trans-anal tube decompression. Since 2012, revision of the medical payment system, it has become possible to be treated with elective operation when using endoscopic metal stent placement that enable to decompress enlarged intestine by transanal approach. This procedure provides safe elective surgery with sufficient preoperative inspection and conventional bowel preparation. We report two cases of acute large bowel obstruction due to colon cancer treated with endoscopic stent placement as a "bridge to surgery".

Leptomeningeal carcinomatosis originating from advanced gastric cancer--a report of three cases and review of the literatures

BACKGROUND

Leptomeningeal carcinomatosis (LMC) is a rare complication of gastric cancer. Case 1. A 57-year-old female was diagnosed with gastric cancer and underwent distal gastrectomy with D2 lymph node dissection. Two years later, the patient suffered from para-aortic lymph node metastases and provided chemotherapy. During the chemotherapy, the patient emergently visited our hospital with chief complaints of a severe headache and dizziness. The above symptoms promptly abated by meningeal drainage, with a high value of the cerebrospinal fluid (CSF) pressure. Despite the administration of subsequent chemotherapy, the patient's clinical state rapidly worsened, including gradual progression of both blindness and hearing loss. Case 2. A 42-year-old male was diagnosed with Stage IV gastric cancer due to both distant lymph node metastases and an ascites. Chemotherapy with S-1 plus docetaxel was initiated. Upon finishing the fifth course of treatment, the patient complained of a severe headache. The magnetic resonance imaging (MRI) findings were suggestive of LMC. Under suspicion of carcinomatous meningitis, the patient underwent both cerebrospinal drainage with a high pressure value of 180 mmH2O and a cytological examination with a diagnosis of Class V. Immediately following the cerebrospinal drainage, the patient's symptoms promptly diminished. Case 3. A 66-year-old female was diagnosed with gastric cancer and underwent total gastrectomy with D2 dissection. About a year later, the patient suffered from the peritoneal dissemination, and provided serial chemotherapy regimens for 13 months. Thereafter the patient suffered from mildly stiff shoulders followed by serial severe headaches, and meningeal drainage was performed. The CSF showed pleocytosis and the presence of neoplastic cells, leading a diagnosis of LMC. After the placement of an Ommaya reservoir, the intrathecal chemotherapy was performed. Within two weeks of treatment, the patient's condition improved significantly, and the cell counts in the CSF obtained from the Ommaya reservoir remained low for six months after the first diagnosis of LMC.

CONCLUSIONS

Although gastric LMC-affected patients often exhibit a fatal clinical course, the administration of intrathecal chemotherapy may improve survival. Systemic chemotherapy may be also administered in a limited number of patients with a superior performance status. At present, each case requires the individual making treatment decisions. Further accumulation of clinical cases and improving the overall understanding of the pathogenesis of this disease is needed in order to advance in the treatment of gastric LMC.

Minimally invasive total pharyng-laryngo-esophagectomy and reconstruction with gastric tube: report of three cases

Total pharyngo-laryngo-esophagectomy (TPLE) is indicated for either cervical esophageal cancer or synchronous double cancer of the thoracic esophagus and head and neck and this operation is extremely invasive. We adopted minimally invasive surgery for three patients who underwent this operation: VATS (video-assisted thoracoscopic surgery) esophagectomy was undergone in left semi-prone position and laparoscopic approach was also applied to reconstruction with gastric tube. After pharyngo-laryngectomy and gastric tube pull-up through post-mediastinal route, cervical anastomosis was performed. Free jejunal interposition was added in a case, while microvascular venous anastomosis between short gastric vein and cervical vein in another two cases. All patients recovered well without any postoperative complications. This is the first report, which describes minimally invasive TPLE using both VATS and laparoscopic technique in addition with plastic surgery.

Outcome of hepatectomy in hepatocellular carcinoma patients aged 80 years and older

BACKGROUND/AIMS

The aim of this retrospective study was to determine the effect of age on the outcome of hepatic resection in octogenarian patients with hepatocellular carcinoma (HCC).

METHODOLOGY

Data of 408 consecutive primary HCC patients who underwent curative hepatectomy were studied. The surgical results of the younger group (<80 years of age) and the elderly group (≥80 years of age) were compared.

RESULTS

Preoperative parameters, such as comorbid conditions and liver function tests, of the younger group (n=385) were comparable with those of the elderly group (n=23). Surgical data and the prevalence of postoperative complications did not differ significantly between the two groups. The long-term prognosis of the elderly group patients was almost identical to that of the younger group patients. Overall 3-year survival rates for the elderly group and the younger group were 95.7% vs. 84.8%, respectively (p=0.56). Disease-free three-year survival rates for the elderly group and the younger group were 47.2% vs. 47.7%, respectively (p=0.65).

CONCLUSIONS

Hepatectomy is a viable treatment alternative with satisfactory surgical outcome for HCC even in patients aged 80 years or older.

Positive and negative regulation of podoplanin expression by TGF-β and histone deacetylase inhibitors in oral and pharyngeal squamous cell carcinoma cell lines

OBJECTIVES

Podoplanin, a transmembrane sialomucin-like glycoprotein, is known to express at high frequency in oral squamous cell carcinomas (OSCC) and possess metastasis-promoting activity such as increased invasion and platelet-aggregating activity. However, the regulatory mechanism of podoplanin expression in OSCC remains unknown.

MATERIALS AND METHODS

In the present study, we investigated the podoplanin expression in both clinical specimens from total 80 patients (50 OSCC and 30 pharyngeal SCC) and in 4 OSCC cell lines in vitro.

RESULTS

Immunohistochemical analysis of surgically resected specimens of OSCC revealed podoplanin expression in 70% of OSCC cases with localization primarily in the basal layer of squamous cancer nest and the expression was inversely correlated with squamous cell differentiation. In vitro analysis of OSCC cell lines revealed 36 that podoplanin expression was decreased in response to the squamous cell differentiation (Cytokeratin 10 expression as a marker) induced by treatment with histone deacetylase (HDAC) inhibitors such as sodium butyrate and trichostatin. Furthermore, transforming growth factor-β (TGF-β) significantly enhanced podoplanin expression in OSCC cell lines in line with increased phosphorylation of Smad2. A TGF-β type I receptor inhibitor (SB431542) significantly inhibited such induction of podoplanin expression by TGF-β at both the protein and mRNA level. However, in a subset of OSCC cell line, its expression was only weakly dependent on TGF-β and squamous differentiation.

CONCLUSION

These results suggest that regulation of podoplanin is not simple, but in the majority of OSCC cell lines, its expression is positively and negatively regulated by TGF-β receptor/Smad signaling pathway and epigenetic mechanism leading to squamous differentiation, respectively.

[Thoracic surgery in patients with autoimmune diseases]

Autoimmune diseases arise from an inappropriate immune response against substances and tissues normally present in the body. Although the pathogenesis are still unclear, several autoimmune diseases, such as dermatomyositis, systemic sclerosis, have a higher incidence of thoracic neoplasm. Also in the mediastinum several autoimmune diseases are known to associate thymoma. While the manifestations of the disease diverse, administration of immunosuppressant are commonly used for the management of aberrant immune response. Immunosuppressive therapies likely to increase susceptibility to infections and associate other side-effects, which could increase the risk of surgery and complicate the perioperative management. In this article we discuss the autoimmune diseases which are known to associate with thoracic and mediastinal neoplasms, and the perioperative management of thoracic surgery in patients with autoimmune diseases.

Excessive axial plaque redistribution during coronary stent implantation confirmed by intravascular ultrasound

We report a case of excessive axial plaque redistribution leading to luminal narrowing at the reference segment confirmed by serial intravascular ultrasound during coronary stent implantation.

Results of a national survey on laparoscopic bariatric surgery in Japan, 2000-2009

INTRODUCTION

In Japan, laparoscopic bariatric surgery has not been popular until recently because morbidly obese patients were infrequently encountered previous and Japanese health insurance does not cover this type of surgery. In 2010, the Japan Research Society for Endoscopic and Laparoscopic Treatments of Obesity undertook the first nationwide survey on laparoscopic bariatric surgery to evaluate its current status and outcomes.

METHODS

A mail survey was sent to the society's 64 member institutions, which included almost all institutions in Japan actively performing laparoscopic gastrointestinal surgery.

RESULTS

From 2000 to 2009, 340 laparoscopic bariatric procedures, in total, were performed in nine of the 64 institutions (14%). The most popular procedure was laparoscopic Roux-en-Y gastric bypass (LRYGB, n=147), second was laparoscopic sleeve gastrectomy (LSG, n=102), and third was laparoscopic adjustable gastric banding (LAGB, n=55). However, the number of LRYGB procedures has decreased while the number of LSG procedures has rapidly increased. Total morbidity rates were 12.2% for LRYGB, 10.9% for LAGB, and 7.8% for LSG. Percent excess weight loss was 78% at 5 years after LRYGB, 52% at 4 years after LAGB, and 68% at 2 years after LSG. Although the bariatric procedures frequently resolved or improved obesity-related comorbidities, LRYGB appears to be superior to LAGB, as was previously reported.

CONCLUSION

The first nationwide survey of laparoscopic bariatric surgery in Japan clearly showed the current status and outcomes of this group of procedures. The Japanese results appear to be comparable to similarly undertaken surveys in Europe and the USA.

True Atomic Resolution Imaging on Semiconductor Surfaces with Noncontact Atomic Force Microscopy

The constant vibration mode and the constant excitation mode in noncontact atomic force microscopy were compared to investigate the force interaction between tip and surface. As a result, we found that the constant excitation mode is much more gentle than the constant vibration mode. We also succeeded in atomic resolution imaging on InP(110) surface not only in the noncontact region but in the contact region for the first time. Furthermore, we found the discontinuity of the force gradient curve on reactive Si(111)7×7 reconstructed surface. We proposed a model to explain the discontinuity with the crossover between the physical and chemical bonding interaction.

Remote access laparoscopic (REAL) surgery: a novel approach for single-port surgery without a visible scar

INTRODUCTION

Single-port laparoscopic surgery usually uses the transumbilical approach. However, the transumbilical incision may be associated with a high frequency of wound-related complications, including trocar site hernia and infection. Therefore, we developed remote access laparoscopic (REAL) surgery, a new access technique for single-port surgery within the pubic hairline. This study reports on a technique developed at our institution and describes our preliminary results.

MATERIALS AND SURGICAL TECHNIQUE

Ten patients with cholecystolithiasis underwent REAL surgery. A single 2.5-cm transverse incision was made medially within the pubic hairline area, and a SILS Port was inserted. A 5-mm flexible endoscope and an articulating grasper or a long laparoscopic grasper were used. Dissection of the gallbladder was achieved with laparoscopic ultrasonic shears just as in the conventional laparoscopic cholecystectomy. All procedures were successfully performed without conversion to conventional laparoscopic technique. There were no postoperative complications, and outpatient evaluation showed a clean scar within the pubic hair area in all patients.

DISCUSSION

Our early experience shows that REAL surgery is feasible and safe. This novel access technique can preserve the native umbilicus and provides an invisible scar that is concealed within the pubic hair.

Comparison of the prevalence of chronic kidney disease in Japanese patients with Type 1 and Type 2 diabetes

AIMS

The relationship between type of diabetes and risk of chronic kidney disease has not been studied in detail. We conducted this study to determine the prevalence of chronic kidney disease in Japanese adults with diabetes, with a particular emphasis on the comparison of Type 1 and Type 2 diabetes.

METHODS

We studied 3,575 Japanese patients with diabetes, 504 with Type 1 (mean +/- SD age 38 +/- 13 years; 350 women and 154 men) and 3071 with Type 2 diabetes (60 +/- 13 years; 1187 women and 1884 men). Prevalence rates of albuminuria [urinary albumin/creatinine ratio (> or = 30 mg/g], decreased estimated glomerular filtration rate (eGFR < 60 ml/min/1.73 m(2)) and chronic kidney disease (defined as albuminuria and/or decreased eGFR) were compared between the two diabetic groups.

RESULTS

The prevalence of albuminuria was higher in Type 2 than Type 1 diabetic patients by both Fisher's exact test (36.1 vs. 15.9%, P < 0.001) and multivariate logistic regression analysis [adjusted odds ratio (OR) = 1.482, 95% confidence interval (CI) = 1.050-2.091, P = 0.025]. The prevalence of decreased eGFR was also higher in Type 2 diabetic patients (25.2 vs. 7.9%, P < 0.001); however, the statistical significance disappeared after adjusting for covariates, including age (OR = 0.656, 95% CI = 0.395-1.088, P = 0.102). The prevalence of chronic kidney disease was also higher in Type 2 diabetic patients (46.0 vs. 19.1%, P < 0.001); however, the statistical significance disappeared in the multivariate analysis. CONCLUSIONS Type 2 diabetic patients are more than twice as likely as Type 1 diabetic patients to have chronic kidney disease due to an age-independent higher prevalence of albuminuria and age-dependent decreased eGFR.

Two-Dimensional Optimization of a Stent for an Aneurysm

This work attempts to optimize stents that are implanted at the neck of coronary or cerebral aneurysms to effect a flow diversion. A two-dimensional version of the stent, which is a series of struts and gaps placed at the neck, is considered as the first step. Optimization is carried out based on the principles of exploration of design space using reductions in velocity and vorticity in the aneurysm dome as the objective functions. Latin hypercube sampling first develops 30–60 samples of a strut-gap arrangement. Flow past an aneurysm with each of these samples is computed using the commercial software FLUENT and the objective functions evaluated. This is followed by a Kriging procedure that identifies the nondominated solutions to the system, which are the optimized candidates. Three different cases of stents with rectangular or circular struts are considered. It is found that placing struts in the proximal region of the neck gives the best flow diversion.

Serum folate and homocysteine and depressive symptoms among Japanese men and women

BACKGROUND/OBJECTIVES

Folate and homocysteine have been implicated to have a role in depression. However, results of epidemiologic studies on this issue have been inconsistent. The objective of this study was to clarify the association between serum folate and homocysteine concentrations and depressive symptoms in Japanese adults.

SUBJECTS/METHODS

We analyzed cross-sectional data for 530 municipal employees (313 men and 217 women), aged 21-67 years, who participated in a health survey at the time of periodic checkup. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Logistic regression analysis was used to estimate odds ratios of depressive symptoms (CES-D scale scores of >or=16) with adjustment for potential confounding variables.

RESULTS

In total, 113 men (36.1%) and 79 women (36.4%) had depressive symptoms. A higher serum folate was associated with a decreased prevalence of depressive symptoms in men. The multivariate-adjusted odds ratios (95% confidence interval) of depressive symptoms for the lowest to highest quartiles of serum folate were 1.00 (reference), 0.53 (0.27-1.03), 0.33 (0.16-0.68) and 0.51 (0.25-1.03), respectively (trend P=0.03). Furthermore, the data suggested a positive association between serum homocysteine and depressive symptoms in men (trend P=0.06). In women, neither folate nor homocysteine was associated with depressive symptoms.

CONCLUSIONS

Low serum folate may be related to an increased prevalence of depressive symptoms in Japanese men.

Outcome of repeat hepatectomy in patients with hepatocellular carcinoma aged 75 years and older

BACKGROUND

We sought to evaluate the influence of age on the outcome of repeat hepatectomies in patients > or = 75 years with recurrent hepatocellular carcinoma (HCC).

METHODS

We studied 121 curative repeat hepatectomies retrospectively. Among the 121 patients, 100, 20, and 1 received second, third, and fourth hepatectomies, respectively. The short-term surgical results of a younger group (<75 years; n = 88) and those of an elderly group (> or = 75 years; n = 33) were compared. The long-term prognosis of the patients who underwent second hepatectomies was also compared between a younger group (<75 years; n = 77) and an elderly group (> or = 75 years; n = 23).

RESULTS

The patients in the elderly group displayed more comorbid conditions pre-operatively, including hypertension and cardiovascular diseases, than the younger group (P < .05); however, there was no significant difference in the incidence of postoperative complications or the duration of postoperative hospital stay. The long-term prognosis in the elderly group was almost identical to that in the younger group. The 3-year overall survival rates for the younger group and the elderly group were 83 vs 73% (P = .51). Disease-free, 3-year survival rates for the younger group and the elderly group were 35% vs 38% (P = .88).

CONCLUSION

Our findings suggest that advanced age by itself does not have an adverse effect on operative outcomes, including postoperative complications and long-term prognosis. Repeat hepatectomy may, therefore, be justified for recurrent HCC in selected elderly patients.