Fast backward steps and detachment of single kinesin molecules measured under a wide range of loads.

To understand force generation under a wide range of loads, the stepping of single kinesin molecules was measured at loads from -20 to 42 pN by optical tweezers with high temporal resolution. The optical trap has been improved to halve positional noise and increase bandwidth by using 200-nm beads. The step size of the forward and backward steps was 8.2 nm even over a wide range of loads. Histograms of the dwell times of backward steps and detachment fit well to two independent exponential equations with fast (~0.4 ms) and slow (>3 ms) time constants, indicating the existence of a fast step in addition to the conventional slow step. The dwell times of the fast steps were almost independent of the load and ATP concentration, while those of the slow backward steps and detachment depended on those. We constructed the kinetic model to explain the fast and slow steps under a wide range of loads.

Oscillatory movement of a dynein-microtubule complex crosslinked with DNA origami.

Bending of cilia and flagella occurs when axonemal dynein molecules on one side of the axoneme produce force and move toward the microtubule (MT) minus end. These dyneins are then pulled back when the axoneme bends in the other direction, meaning oscillatory back and forth movement of dynein during repetitive bending of cilia/flagella. There are various factors that may regulate the dynein activity, e.g. the nexin-dynein regulatory complex, radial spokes, and central apparatus. In order to understand the basic mechanism of dynein's oscillatory movement, we constructed a simple model system composed of MTs, outer-arm dyneins, and crosslinks between the MTs made of DNA origami. Electron microscopy (EM) showed pairs of parallel MTs crossbridged by patches of regularly arranged dynein molecules bound in two different orientations, depending on which of the MTs their tails bind to. The oppositely oriented dyneins are expected to produce opposing forces when the pair of MTs have the same polarity. Optical trapping experiments showed that the dynein-MT-DNA-origami complex actually oscillates back and forth after photolysis of caged ATP. Intriguingly, the complex, when held at one end, showed repetitive bending motions. The results show that a simple system composed of ensembles of oppositely oriented dyneins, MTs, and inter-MT crosslinkers, without any additional regulatory structures, has an intrinsic ability to cause oscillation and repetitive bending motions.

Parathyroid carcinoma detected within the thyroid.

Parathyroid carcinoma (PC) is a rare disease accounting for approximately 1% of primary hyperparathyroidism cases. The preoperative differentiation of PC is critical because PC can occasionally metastasise and invade the local tissue. However, this is challenging in asymptomatic cases and when the tumour is adjacent to the thyroid. Herein, we report a rare case of PC without clinical symptoms. Fine needle aspiration was performed, despite being contraindicated in PC, and an intrathyroidal tumour was preoperatively suggested.

Intracranial subarachnoid hemorrhage following cervical laminoplasty: a report of two cases.

Intracranial hemorrhage is a rare complication of spinal surgery. Case 1 was a 58-year-old man who underwent cervical laminoplasty. No apparent iatrogenic dural rupture or cerebrospinal fluid leakage was observed. An hour after the surgery, the patient had convulsions and became restless thereafter. CT revealed an intracranial subarachnoid hemorrhage (SAH). The patient recovered normal consciousness the next morning. Case 2 was a 68-year-old woman who underwent cervical laminoplasty without postoperative cerebrospinal fluid leakage. Six days after the surgery, the patient continued to complain of nausea and headache. By 13 days, the patient reported relief from her symptoms. There was no evidence of cerebral aneurysm, or vascular malformation in both cases. Patients undergoing cervical laminoplasty might be at risk for developing SAH. Careful attention to intraoperative neck positioning, strict monitoring and control of perioperative blood pressure, and complete dural repair are essential measures for preventing SAH.

Impaired Value of 99m Tc-GSA Scintigraphy as an Independent Risk Factor for Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma.

BACKGROUND: Posthepatectomy liver failure (PHLF) was recently defined with the corresponding recommendations as follows: grade A, no change in clinical management; grade B, clinical management with noninvasive treatment; and grade C, clinical management with invasive treatment. In this study, we identified the risk factors for grade B and C PHLF in patients with hepatocellular carcinoma (HCC). METHODS: Of 339 HCC patients who underwent curative hepatic resection, 218 were included for analysis. The LHL15 index (uptake ratio of the liver to that of the liver and heart at 15 min) was measured by 99m Tc-GSA (99m technetium-labelled galactosyl human serum albumin); remnant LHL15 was calculated as LHL15 × [1 - (resected liver weight - tumor volume)/whole liver volume without tumor]. RESULTS: A total of 163 patients were classified as having no PHLF, whereas 17, 37, and 1 patient had PHLF grade A, B, and C, respectively. There were significant differences in indocyanine green R15, serum albumin, prothrombin time, Child-Pugh classification, LHL15 and remnant LHL15 between patients with grades B/C PHLF and patients with grade A or no PHLF. Only remnant LHL15 was identified as an independent risk factor for grades B/C PHLF (p = 0.023), with a cut-off value of 0.755. CONCLUSIONS: Remnant LHL15 was an independent risk factor for grades B/C PHLF. Patients with impaired remnant LHL15 value of <0.755 should be carefully monitored for PHLF.

Lower early postnatal oxygen saturation target and risk of ductus arteriosus closure failure.

BACKGROUND: Early postnatal hyperoxia is a major risk factor for retinopathy of prematurity (ROP) in extremely premature infants. To reduce the occurrence of ROP, we adopted a lower early postnatal oxygen saturation (SpO2 ) target range (85-92%) from April 2011. Lower SpO2 target range, however, may lead to hypoxemia and an increase in the risk of ductus arteriosus (DA) closure failure. The aim of this study was therefore to determine whether a lower SpO2 target range, during the early postnatal stage, increases the risk of DA closure failure. METHODS: Infants born at <28 weeks' gestation were enrolled in this study. Oxygen saturation target range during the first postnatal 72 h was 84-100% in study period 1 and 85-92% in period 2. RESULTS: Eighty-two infants were included in period 1, and 61 were included in period 2. The lower oxygen saturation target range increased the occurrence of hypoxemia during the first postnatal 72 h. Prevalence of DA closure failure in period 2 (21%) was significantly higher than that in period 1 (1%). On multivariate logistic regression analysis, the lower oxygen saturation target range was an independent risk factor for DA closure failure. CONCLUSION: Lower early postnatal oxygen saturation target range increases the risk of DA closure failure.

Parenchyma-preserving hepatectomy based on portal ramification and perfusion of the right anterior section: preserving the ventral or dorsal area.

BACKGROUND: Anatomical hepatectomy aims to eliminate the spread of malignant tumor cells via portal vein systemically. An anatomical concept of the right anterior section (RAS) and preservation of the liver parenchyma within the RAS has been proposed. METHODS: We focused on the anatomical concept of the RAS based on portal perfusion and described surgical procedures to preserve the ventral or dorsal RAS using preoperative simulation. RESULTS: In 370 patients undergoing a preoperative simulation, the ramification of the tertiary portal branches of the RAS could be divided into three types including the cranio-caudal type; Couinaud's classification in 50% of patients, ventro-dorsal type in 26% of patients, and multiple type in 24% of patients. Then in 32 patients of the ventro-dorsal type, curative parenchyma-sparing hepatectomy of the RAS was performed, preserving the ventral and dorsal RAS in 14 and 18 patients, respectively. There were no differences in the postoperative complications and long-term survival compared with the results obtained after segment 5 or 8 resection (n = 33). CONCLUSION: Three-dimensional simulation revealed three types of portal vein ramification of the RAS. Parenchyma-preserving hepatectomy based on the precise portal ramification may contribute to safe and curative hepatectomy in selected cases with liver neoplasm involving the RAS.

Analysis of unique liver volume restoration after laparoscopic fenestration of liver cysts.

INTRODUCTION: Laparoscopic fenestration is a standard procedure for the treatment of non-parasitic liver cysts. After fenestration, the remnant liver often restores its volume. However, no systematic analysis of the phenomenon exists. In the present study, the pattern of liver volume restoration after laparoscopic fenestration of liver cysts was analyzed, and the mechanism for the unique restoration was investigated. METHODS: Seven patients with giant non-parasitic liver cysts underwent laparoscopic fenestration. Liver volume restoration in each section and changes in the diameter of the portal branch were analyzed after fenestration with CT or MRI. In two patients, regional liver volume restoration was assessed in detail using region-growing software, and change in portal flow distribution was estimated using computational fluid dynamics. Then, the regional liver volume restoration rate was compared with the portal hemodynamic changes. RESULTS: Liver volume restoration after fenestration was dependent on the size and position of the cysts; it not uniform throughout the remnant liver. The liver volume restoration in sections that had been compressed by giant cysts was significantly greater than in other areas after fenestration. This volume restoration was accompanied by an increase in the diameters of the portal branches in these sections. In addition, a strong correlation between the regional liver volume restoration rate and the changes in portal flow distribution existed in the computationally analyzed cases. CONCLUSION: Liver volume restoration after the fenestration of giant liver cysts non-uniformly occurs in the remnant liver. Improved portal vein circulation in the hepatic area adjacent to the excised giant liver cysts most likely regulates the greater regional volume restoration rate in the area.

Safety of hepatic resection for hepatocellular carcinoma in obese patients with cirrhosis.

PURPOSE: This study aimed at investigating the safety of hepatic resection for hepatocellular carcinoma (HCC) in obese patients with cirrhosis in Japan. METHODS: We reviewed the clinical records of 202 patients with liver cirrhosis, who underwent hepatic resection for HCC between January, 2001 and August, 2011. The patients were divided into three groups according to their body mass index (BMI): the normal body weight (BMI < 24.9 kg/m(2)), obese class I (BMI 25.0-29.9 kg/m(2)), and obese class II (BMI ≥ 30 kg/m(2)) groups. We compared the patient backgrounds, intraoperative factors, and postoperative complications among the three groups. RESULTS: The normal body weight, obese class I, and obese class II groups comprised 138 (68.3 %), 55 (27.2 %), and 9 (4.5 %) patients, respectively. The incidence of non-B non-C cirrhosis was higher in the obese class II group (22 %) than in the normal body weight group (14 %, p = 0.034). Intraoperative blood loss tended to be higher in the obese class II patients than in the other two groups. Postoperative complications and mortality did not differ significantly among the three groups. According to multivariate analysis, obesity was not a risk factor for postoperative complications (Clavien-Dindo classification Grade III or higher) or mortality. CONCLUSION: Hepatic resection for HCC can be performed safely in obese patients with cirrhosis.

Regional hepatic regeneration after liver resection correlates well with preceding changes in the regional portal circulation in humans.

BACKGROUND AND AIMS: While portal hemodynamics largely affects the liver regeneration after partial hepatectomy, whether the remnant liver homogeneously regenerates is unclear, especially in humans. We hypothesized that change in flow distribution varies in each remnant portal branch after liver resection in humans and the liver consequently regenerates heterogeneously. METHODS: Twenty-two patients who underwent anatomical hepatic resection preserving intact drainage veins were analyzed. Based on perioperative contrast-enhanced computed tomography, the regional hepatic regeneration in each segment was analyzed using a region growing software. The perioperative change in the distribution of blood flow in each portal branch was assessed using the computational flow dynamics technique. The correlation between the change in the portal flow distribution and the later regional hepatic regeneration was investigated. RESULTS: The distribution of portal blood flow in each remnant branch largely changed at 2 weeks (71-389 %). Each remnant segment also heterogeneously regenerated at 3 months (85-204 %). Meanwhile, a good correlation between the regional regeneration rate at 3 months and the relative change in the flow distribution in each circulating portal branch at 2 weeks was detected in each patient (r = 0.74-0.99). CONCLUSIONS: After partial hepatectomy, the change in blood flow varies in each remnant portal branch and the liver heterogeneously regenerates in humans. The good correlation between the earlier change in the portal flow distribution and the later regional hepatic regeneration strongly suggests that the portal venous flow most likely regulates the non-uniform liver regeneration after hepatic resection in humans.

Laparoscopic management of giant splenic true cyst with partial splenectomy: a case report.

Non-parasitic splenic cysts are relatively rare, and the optimal surgical treatment for them remains controversial. Laparoscopic unroofing is a relatively safe and easy technique, but a significant number of recurrences has been reported. Thus, complete cystectomy with partial splenectomy is recommended by several surgeons. However, patients sometimes suffer from intraoperative bleeding. Here, we report a patient with a giant non-parasitic splenic cyst who underwent subtotal cystectomy with partial splenectomy. After the dissection of the vessels circulating the upper pole at the splenic hilum, the resection line of the splenic parenchyma was on the ischemic side of the cyanotic demarcation line. A vessel sealing system and laparoscopic coagulation shears were used for the resection. We intentionally left about 10% of the cyst wall to avoid bleeding from the non-ischemic splenic parenchyma and remaining vessels. No recurrence has been detected after 6 months of observation. We believe this method could be a useful alternative procedure for the treatment of non-parasitic splenic cysts and preservation of the splenic parenchyma.

Liver cirrhosis treated by living donor liver transplantation in a patient with AGL mutation c.2607-2610delATTC and c.1672dupA.

Glycogen storage disease type III (GSD III) is an inherited disorder characterized by the accumulation of abnormal glycogen in the liver. Hepatic manifestations were considered as improving with age; however, patients live longer and liver cirrhosis is being recognized. We report a patient of GSD IIIa with liver cirrhosis, which was treated successfully by living donor liver transplantation. The patient proved to be a compound heterozygote for a novel small deletion c.2607-2610delATTC and a known duplication c.1672dupA in AGL, a gene coding glycogen debranching enzyme responsible for GSD III. Molecular diagnosis helped clinical decision-making.

Rare form of extraovarian primary peritoneal papillary serous carcinoma with solitary cystic lesion mimicking a liver tumor; report of a case.

Extraovarian primary peritoneal serous papillary carcinoma (EOPPC) has a similar clinical presentation to that of ovarian cancer in advanced stages, such as peritoneal dissemination and a large amount of ascites, while EOPPC with a solitary tumor is very rare. We report here a 47-year-old Japanese woman with solitary form of EOPPC mimicking a liver tumor. Ovaries of both sides had no malignant lesion, which was histologically confirmed. Histological examination revealed that the tumor was located at the right diaphragm and partially invaded into the liver, and papillary or ductal proliferation of the tumor cells with an occasional appearance of psammoma bodies was detected. Immunohistologically, the tumor cells were positive for CA 125 and Ber-EP4 and negative for D2-40 or calretinin, ruling out the possibility of mesothelioma, and the diagnosis of the tumor was EOPPC. After the operation, the patient received chemotherapy with carboplatin and paclitaxel, but died 10 months later due the progression of recurrence. The present case is very rare form of EOPPC without any ascites or peritoneal dissemination.

Abnormal Movements of Japanese Infants following Treatment with Midazolam in a Neonatal Intensive Care Unit: Incidence and Risk Factors.

Background. This study was conducted to investigate the incidence of, and factors associated with, myoclonus-like abnormal movements of Japanese infants following treatment with midazolam in a neonatal intensive care unit (NICU). Methods. We retrospectively investigated abnormal movements and associated risk factors in Japanese infants (less than 1 year old) who received continuous intravenous midazolam treatment in the NICU of the Neonatal Medical Center, Kumamoto City Hospital, Japan, between April 2007 and March 2009. Results. The study included 94 infants who received 119 sessions of midazolam treatment in total. Nine infants (9.6%) developed abnormal movements attributable to midazolam. These nine patients had a significantly lower gestational age at birth, a significantly lower number of weeks after conception at the start of midazolam treatment, and significantly lower body weight compared with patients free of abnormal movements. Logistic regression analysis revealed neonatal asphyxia as a factor associated with an elevated risk of abnormal movements (P = 0.03). Conclusion. The incidence of abnormal movements after midazolam treatment was about 9.6% among the Japanese NICU infants. This result suggests that neonatal asphyxia may be involved in the onset of abnormal movements in infants treated with midazolam.

[A case of pyogenic spondylitis mimicking spinal invasion of lung cancer].

A 65-year-old man who had suffered from traumatic spinal cord injury had chronic lumbar pain. He had exacerbation of lumbar pain and intermittent fever and consulted several doctors, but the cause of the lumbar pain was unknown. An orthopedic specialist took an MRI. Spinal MRI showed increased signal intensity at the level of T10-11 and a mass in his right lower lung field, so he was referred to our hospital. Two transbronchial lung biopsy procedures failed to obtain malignant cells. CT guided biopsy showed fibrous and hyalinizing tissue contained plasma cells and lyphocytes. Staphylococcus aureus was cultured from the second bronchial lavage fluids of brush and blood cultures, so we began administration of ampicillin-sulbactam. Avoiding threatened or actual cord compression due to collapse resulting from spinal instability, posterior fusion with instrumentation was done through the back of his chest wall. At once, bone biopsy was done, and showed no malignant cells. As soon as antibacterial treatment was stopped after the operation, he had bloody sputa and fever. The antibacterial agent was resumed and the symptoms improved. The mass decreased in size and lumbar pain improved gradually, so we concluded the diagnosis was pyogenic spondylitis caused by S. aureus. After about 5 months of antibacterial treatment, the tumor substantially diminished.

Evaluation of the vancomycin dosage regimen based on serum creatinine used in the neonatal intensive care unit.

BACKGROUND: Vancomycin is frequently used for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections; however, determining the optimal dosage for neonates is difficult because of their immature renal function. METHODS: Serum creatinine-based dosing was introduced in Kumamoto City Hospital Neonatal Medical Center. Serum trough concentration and therapeutic efficacy of vancomycin were evaluated before and after the introduction of the creatinine-based dosing. RESULTS: When the therapeutic range of serum trough concentration of vancomycin at steady state was set to 5-15 µg/mL, 20 trough concentrations (48.8%) were within the therapeutic range and 21 trough concentrations were outside the therapeutic range before the introduction of the serum creatinine-based dosing. After the introduction of serum creatinine-based dosing, 18 trough concentrations (81.8%) were within the therapeutic range and 4 trough concentrations were not, and there was an increase in the number of patients with trough concentrations in the therapeutic range (P= 0.01; Fisher's exact test). CONCLUSIONS: The serum creatinine-based dosing of vancomycin is useful in maintaining the appropriate serum level of vancomycin in neonates.

Direct synthesis of water-dispersible FePt nanoparticles capped with L-cysteine.

A direct synthetic route of FePt nanoparticles (NPs) has been developed. Reduction of platinum acethylacetonate (Pt(acac)2) and thermal decomposition of iron carbonyl (Fe(CO)5) in the presence of L-cysteine produced fcc FePt NPs with a mean diameter of 2.9 nm. Capping of the FePt NPs with L-cysteine is accomplished by a thiolate linkage between the amino acid and the NP surfaces, which renders them water-dispersible rather than in organic solvents. SQUID magnetization study demonstrated that the FePt NPs exhibited superparamagnetic behavior at 300 K. For the structural model of the FePt NPs, the Fe K-edge and Pt L(III)-edge XAFS results suggest that most of the Pt atoms are preferentially located in the core region, the Fe atoms are preferentially located in the shell region.

Minimally invasive laparoscopic liver resection: 3D MDCT simulation for preoperative planning.

BACKGROUND/PURPOSE: Laparoscopic liver resection has not gained wide acceptance compared with other laparoscopic procedures. We evaluated the impact of simulated surgery using data from multidetector CT scanning on planning for laparoscopic hepatectomy. METHODS: The hepatectomy simulation system was programmed to perform three-dimensional reconstruction of the vasculature and to calculate the liver resection volume and surgical margin. In 35 patients undergoing laparoscopic hepatectomy or laparoscopy-assisted hepatectomy, the liver resection volume and margin were estimated by simulation preoperatively. Then, the estimated values were compared with the actual resected liver weight and margin. RESULTS: Three-dimensional reconstruction allowed stereoscopic identification of the tumor-bearing portal vein and draining vein. The predicted liver resection volume and margin both showed a significant correlation with the actual values: the mean difference was 21 mL (P < 0.0001) and 1.3 mm (P < 0.01), respectively. Preoperative planning based on simulated resection facilitated laparoscopic mobilization of the liver and mini-laparotomy resection of a large tumor located in the upper right lobe. CONCLUSIONS: Three-dimensional simulation of hepatectomy facilitated intraoperative identification of the vascular anatomy, and accurately predicted the resected liver volume and surgical margin. This simulation method should contribute to preoperative planning for safe and curative laparoscopic hepatectomy.

Synthesis and characterization of FePd magnetic nanoparticles modified with chiral BINAP ligand as a recoverable catalyst vehicle for the asymmetric coupling reaction.

The initial thermal decomposition of iron carbonyl (Fe(CO)(5)), followed by reduction of palladium acetylacetonate (Pd(acac)(2)) produced FePd nanoparticles (NPs) with an Fe(x)O(y)-rich core and a Pd-rich shell. The as-synthesized NPs were subsequently treated with (S)-2,2'-bis(diphenylphosphino)-1,1'-binaphthene ((S)-BINAP) as a chiral modifier, which provides them with the optical activity to show a negative Cotton effect in the circular dichroism (CD) spectrum. Characterization by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), superconducting quantum interface device (SQUID) and X-ray absorption fine structure (XAFS) measurements was performed. The FePd NPs modified with (S)-BINAP had a mean diameter of ca. 5.6 nm, and exhibited superparamagnetic behavior at 300 K with zero remanence and coercivity. The FePd-(S)-BINAP was shown to catalyze the asymmetric Suzuki-Miyaura coupling reaction with easy recovery from the reaction mixture by applying an external magnet. The designed architecture enabled the powerful combination of two functionalities, magnetism that responds to a magnetic field for easy recycling, as well as an optically active catalytic center that promotes the asymmetric coupling reaction.

Administration of IL-33 induces airway hyperresponsiveness and goblet cell hyperplasia in the lungs in the absence of adaptive immune system.

Systemic administration of IL-18 induces polyclonal IgE responses by causing NKT cells to express CD40 ligand and to produce IL-4. Administration of IL-33 also induces IgE response, although the mechanism underlying IgE response is unclear. Here, we compared the effects of IL-18 and IL-33 on bone marrow-derived mast cells and basophils as well as non-polarized and T(h)2-polarized CD4(+) T cells in vitro. Basophils, comprising IL-18Ralpha(+) cells (14.2%) and IL-33Ralpha(+) cells (34.6%), and mast cells, comprising IL-18Ralpha(+) cells (2.0%) and IL-33Ralpha(+) cells (95.6%), produce IL-4, IL-6, IL-13, granulocyte macrophage colony-stimulating factor (GM-CSF) and chemokines (RANTES, MIP-1alpha, MIP-1beta and MCP-1), upon stimulation with IL-18 and/or IL-33 in the presence of IL-3. Only basophils strongly produce IL-4. Furthermore, compared with mast cells, basophils produce larger amounts of the above cytokines and chemokines in response to IL-33. Level of IL-33Rbeta-mRNA expression in basophils is higher than that in mast cells. Effect of IL-33 is dependent on ST2 binding, and its signal is transduced via MyD88 in vitro. We also found that IL-2 plus IL-18 or IL-33 alone stimulates non-polarized or T(h)2-polarized CD4(+) T cells to produce IL-4 and IL-13 or IL-5 and IL-13, respectively. We finally showed that administration of IL-33 into mice ST2/MyD88 dependently induces airway hyperresponsiveness (AHR) and goblet cell hyperplasia by induction of IL-4, IL-5 and IL-13 in the lungs. Furthermore, same treatment of RAG-2(-/-) mice, lacking T and B cells, more strikingly induced AHR with marked goblet cell hyperplasia and eosinophilic infiltration in the lungs. Thus, IL-33 induces asthma-like symptom entirely independent of acquired immune system.