The purinergic receptor P2Y, G-protein coupled, 2 (P2RY2) gene associated with essential hypertension in Japanese men

P2RY2 has an important function in the regulation of blood pressure by activating adenosine triphosphate (ATP). The aim of this study was to investigate the association between the human P2RY2 gene and essential hypertension (EH) through a haplotype-based case-control study that included two gender groups. The 273 EH patients and 255 age-matched controls were genotyped for five single-nucleotide polymorphisms (SNPs) of the human P2RY2 gene (rs4944831, rs1783596, rs4944832, rs4382936 and rs10898909). Data were analysed for men and women separately and then as a combined total group. For the total and the men only groups, the genotype distribution of the T allele of rs4944831 and the recessive model (GG vs TG+TT) of rs4944831 differed significantly between the EH patients and controls (P=0.028 and 0.019; P=0.009 and 0.008, respectively). Logistic regression showed that for the total and men groups, the TG+TT genotype of rs4944831 was more prevalent in EH patients than in the controls (P=0.026 and 0.011, respectively). For men, the overall distribution of the haplotype (SNP2-SNP4-SNP5) was significantly different between the EH patients and the controls (P=0.006). As compared with controls, the frequency of the T-A-G haplotype was significantly higher, whereas the T-C-G haplotype was significantly lower for the EH patients (P=0.001 and 0.014, respectively). In conclusion, the present results indicate that rs4944831 and the T-A-G haplotype of the human P2RY2 gene might be genetic markers for EH in Japanese men.

Methodologies to assess blood flow in cerebral aneurysms: current state of research and perspectives

With intracranial aneurysms disease bringing a weakened arterial wall segment to initiate, grow and potentially rupture an aneurysm, current understanding of vessel wall biology perceives the disease to follow the path of a dynamic evolution and increasingly recognizes blood flow as being one of the main stakeholders driving the process. Although currently mostly morphological information is used to decide on whether or not to treat a yet unruptured aneurysm, among other factors, knowledge of blood flow parameters may provide an advanced understanding of the mechanisms leading to further aneurismal growth and potential rupture. Flow patterns, velocities, pressure and their derived quantifications, such as shear and vorticity, are today accessible by direct measurements or can be calculated through computation. This paper reviews and puts into perspective current experimental methodologies and numerical approaches available for such purposes. In our view, the combination of current medical imaging standards, numerical simulation methods and endovascular treatment methods allow for thinking that flow conditions govern more than any other factor fate and treatment in cerebral aneurysms. Approaching aneurysms from this perspective improves understanding, and while requiring a personalized aneurysm management by flow assessment and flow correction, if indicated.

Cutaneous accumulation of abnormal polyglutamine proteins of patients with dentatorubral-pallidoluysian atrophy

BACKGROUND AND PURPOSE

Dentatorubral-pallidoluysian atrophy (DRPLA) is a hereditary spinocerebellar degeneration caused by expansion of a trinucleotide CAG repeat encoding a polyglutamine tract in a disease protein atrophin-1. The clinical features include ataxia, choreoathetosis, and dementia, which result from neural degeneration caused by the mutant atrophin-1.

METHODS

We performed skin biopsy in two patients with DRPLA.

RESULTS

We found multiple clear cells in the epidermis, which were positive for proteins containing an expanded polyglutamine stretches. The clear cells were p63 (+), S-100 (-), and cytokeratin 20 (-), showing that they were keratinocytes. Negative or weak signals of pan-cytokeratin were consistent with the finding of decreased tonofilaments at the electron microscopic level.

CONCLUSIONS

The presence of clear keratincoytes showed that the mutant proteins interfered in cellular functions not only in neural cells but also in keratinocytes. The skin is accessible by biopsy, making it important in the diagnosis. Furthermore, the polyglutamine staining in the skin may be useful for evaluation of therapeutic modalities for DRPLA and other polyglutamine diseases.

A new rapid and sensitive detection method for cereulide-producing Bacillus cereus using a cycleave real-time PCR

AIMS

To develop a rapid and sensitive detection method for cereulide-producing Bacillus cereus using a real-time PCR based on the sequence of the cereulide synthesis gene.

METHODS AND RESULTS

A total of 56 cereulide-producing B. cereus and 15 cereulide-negative strains were tested. We designed specific primers and probes for the detection of cereulide-producing B. cereus. The new cycleave real-time PCR assay gave positive detections for all of 56 cereulide-producing B. cereus strains, whereas all other strains including 10 systemic infectious disease strains were negative. No cross-reaction was observed and the internal control showed positive for all samples.

CONCLUSIONS

The performance of the assay was highly reproducible and specific for cereulide-producing B. cereus. The positive detection was obtained within only 2 h for cereulide-producing strains. The detection limit of this assay was evaluated as 10(4) CFU g(-1) food sample. The assay also confirmed that strains from systemic infectious cases were cereulide-negative.

SIGNIFICANCE AND IMPACT OF THE STUDY

This assay is applicable for contaminated foods as well as specimens from infectious disease cases. We recommend this assay for routine examination of suspected B. cereus food poisonings.

[Outcomes of bronchoplasty procedures for lung cancer]

A sleeve lobectomy is an established general thoracic surgical procedure. To improve clinical outcomes following the procedure, we reviewed the records of 60 patients who underwent a bronchoplasty procedure in our department from 1992 to 2007. Induction chemotherapy was performed for 20, of whom 10 underwent radiotherapy as well. For all subjects, the postoperative mortality and morbidity rates were 1.7% and 33.3%, respectively. Induction therapy did not significantly affect those rates, though complications related to bronchial anastomoses occurred exclusively in subjects who received that therapy. The overall 5-year survival rate was 51.0%, while subjects with pN0 (67.9%) and pN1 (60.0%) disease, and those in stage I (79.1%) and stage II (59.9%) had better survival as compared with patients with pN2 (16.9%) disease, and those in stage III (21.8%) and stage IV (0%). Furthermore, the survival rate of yp-stage I and II patients was significantly greater than that of those in yp-stage III and IV (59.9% vs. 14.3%, p = 0.0158). We concluded that patients in stages I, II or with pN0-1 disease are good candidates for a bronchoplasty procedure, though induction therapy should be considered thereafter. In addition, due diligence for postoperative complications is necessary.

[Full-thickness pleural biopsy using an Insulation-tipped Diathermic Knife in a patient with malignant pleural mesothelioma]

A 72-year-old woman was pointed out a right pleural effusion and thickening pleura on the chest computed tomography. The patient underwent semiflexible thoracoscopy under local anesthesia at the endoscopy room. The patient was placed in the lateral decubitus position, and flexible trocar was inserted with the single puncture technique. At the macroscopic findings, the parietal pleura were thickened prominently, and patchy plaques were occasionally recognized. A standard biopsy forceps hardly grasped pleura because of presence of scar, so we performed pleural biopsy using Insulation-tipped Diathermic (IT) knife. A subpleural injection of saline containing 0.5% lidokine and 0.005% epinephrine was performed for raising the affected parietal pleura with an injection needle. After a pin hole was made, the pleural lesion was incised in a circle by manipulating the IT knife, and the incised pleura were removed. Pathology revealed extensive fibrosis and epithelial mesothelioma by the specimen. This biopsy technique using IT knife through semiflexible thoracoscopy enabled to obtain a full-thickness pleura It is thought to be useful for the diagnosis of malignant pleural mesothelioma (MPM) in which standard forceps are difficult to grasp.

Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model--a report on the Virtual Intracranial Stenting Challenge 2007

This paper presents the results of the Virtual Intracranial Stenting Challenge (VISC) 2007, an international initiative whose aim was to establish the reproducibility of state-of-the-art haemodynamical simulation techniques in subject-specific stented models of intracranial aneurysms (IAs). IAs are pathological dilatations of the cerebral artery walls, which are associated with high mortality and morbidity rates due to subarachnoid haemorrhage following rupture. The deployment of a stent as flow diverter has recently been indicated as a promising treatment option, which has the potential to protect the aneurysm by reducing the action of haemodynamical forces and facilitating aneurysm thrombosis. The direct assessment of changes in aneurysm haemodynamics after stent deployment is hampered by limitations in existing imaging techniques and currently requires resorting to numerical simulations. Numerical simulations also have the potential to assist in the personalized selection of an optimal stent design prior to intervention. However, from the current literature it is difficult to assess the level of technological advancement and the reproducibility of haemodynamical predictions in stented patient-specific models. The VISC 2007 initiative engaged in the development of a multicentre-controlled benchmark to analyse differences induced by diverse grid generation and computational fluid dynamics (CFD) technologies. The challenge also represented an opportunity to provide a survey of available technologies currently adopted by international teams from both academic and industrial institutions for constructing computational models of stented aneurysms. The results demonstrate the ability of current strategies in consistently quantifying the performance of three commercial intracranial stents, and contribute to reinforce the confidence in haemodynamical simulation, thus taking a step forward towards the introduction of simulation tools to support diagnostics and interventional planning.

Impact of stent design on intra-aneurysmal flow. A computer simulation study

SUMMARY

In addition to providing a skeleton for vessel reconstruction, stent implantation as used for cerebral aneurysm treatment can induce flow redirection, thus reducing vortical flow velocities within the aneurysm cavity. Further, stent characteristics such as strut size, porosity and cell shape influence the changes in intra-aneurysmal flow by analog simulations. The purpose of this computer simulation study was to visualize the flow pattern over the entire neck area of a side wall aneurysm while changing the stent parameters. A 3-D computer model aneurysm was constructed to have a parent artery of 5 mm diameter and an aneurysm of 10 mm diameter. The distance between the midline of main artery and center point of the aneurysm was 6.8 mm, providing a neck length of 5 mm, a width of 3.6 mm, and a neck area of 14 mm 2. The simulations were carried out with a Finite Element Method based flow simulation package. The incompressible Navier-Stokes equation was solved for a steady flow with a mean speed of 290 mm/s, steady viscosity of 3.83 cp, and density of 1.0 g/cm3. Two parallel stent struts (dimensions: 100 mum m 100 mum m 2.0 mm) were introduced into the plane of the aneurysm neck. The fraction of the aneurysm neck cross-section occupied by the stent was 2.83% in all cases. The velocity distribution through the neck of the aneurysm was calculated for three different choices of separation between the struts for each of two orientations of the struts (parallel and perpendicular) relative to the vessel axis. The flow pattern in the aneurysm was composed of an inflow zone at the distal neck and of an outflow zone at the proximal neck. The placement of stent struts at the aneurysm neck resulted in a decrease in the mean speed in the aneurysm. The degree of reduction and the distribution of flow through the neck did depend on the orientation of the stent struts. The struts, when placed parallel or perpendicular to the parent vessel axis affected the mean speed through the aneurysm neck differently.

Studies on Design Optimization of Coronary Stents

The stent design itself seems to be one of the factors responsible for restenosis. As a remedy, the present work attempts to perform a design optimization of coronary stents from a hemodynamic point of view. For the purpose, we have applied the principles of modern exploration of design space restricting ourselves to two-dimensional considerations. Width, thickness, and spacing of the struts of the stent formed the design variables. The objectives chosen for optimization were the vorticity generated, length of recirculation zone, and the reattachment distance in between the struts. Both semicircular and rectangular cross sections of stents were included. Starting with the range of design variables, sample stent cases were generated using Latin hypercube sampling. Objective functions were calculated for each of these by computing the two-dimensional flow using software FLUENT under the assumption of a steady, Newtonian flow considering a model stent with three struts. This was followed by Kriging to construct a response surface, which gives the relationship between the objectives and the design variables. The procedure gave nondominated fronts, which consist of optimized designs. Stents with minimum vorticity, with minimum recirculation distance, and the ones with maximum reattachment length in between struts were generated. The procedure is capable of producing the optimum set of design variables to achieve the prescribed objectives.

Prognosis of patients with intrahepatic recurrence after hepatic resection for hepatocellular carcinoma: a retrospective study

AIMS

Hepatic resection is the most effective therapy for hepatocellular carcinoma (HCC); however, intrahepatic recurrence is common. Predictors of survival after intrahepatic recurrence have not been fully investigated. To clarify the prognosis and choice of treatment of intrahepatic recurrence after hepatic resection, we conducted a comparative retrospective analysis of 147 patients with HCC who underwent hepatic resection.

METHODS

We retrospectively examined the relations between clinicopathologic factors, including the number of recurrent intrahepatic tumors and long-term prognosis after recurrence in 147 HCC patients who underwent resection. We also examined long-term survival after recurrence based on treatment types and recurrence pattern.

RESULTS

Patients with multiple tumors (n=83) showed less tumor differentiation, more frequent portal invasion, a higher alpha-fetoprotein level, and larger tumors than did patients with solitary tumor (n=64). In the solitary tumor group, local ablation therapy and repeat hepatic resection were performed in 25 and 10, respectively. In the multiple tumor group, 59 were treated by transarterial chemoembolization. Multivariate analysis showed intraoperative blood transfusion and multiple tumors to be independent risk factors for poor cancer-related survival after recurrence. By subset analysis based on treatment types and recurrence pattern, survival after recurrence was significantly better in patients treated by local ablation therapy than those treated by other therapies in both solitary and multiple tumor groups.

CONCLUSIONS

For patients with solitary recurrence, a good prognosis is predicted. Local ablation therapy is a best candidate for treatment of solitary and multiple intrahepatic recurrences after hepatic resection.

Peripheral nerve regeneration through the space formed by a chitosan gel sponge

The clinical treatment of traumatized peripheral nerves often requires grafting of autologous cutaneous nerves. However, there are drawbacks in sacrificing healthy nerves and tissue scarring. In this study, an artificial material, freeze-dried chitosan gel sponge, was examined as a scaffold for nerve regeneration in rats. An 8-mm gap was made by removing a segment of the sciatic nerve, and the distal and proximal stumps were sandwiched by chitosan gel sponge. Rats were killed at 4, 7, 14, and 28 days, and 2 and 4 months after the operation and histological and morphometric evaluations were performed. Regenerating axons were observed at 4 days after the operation. Regenerating nerves extended the distal stump at 14 days after surgery. By electron microscopy, numerous macrophages appeared to phagocyte chitosan, and made a dense cell layer on the chitosan. Regenerating axons did not touch the chitosan, and extended through the space surrounded by macrophage-stacked chitosan. Regenerating nerves were well-myelinated 2 months after surgery. Regenerating nerves were on average 2.45 and 2.75 microm in diameter at 2 and 4 months, respectively, after surgery. These results indicate that the chitosan gel sponge sandwich might be suitable as a graft for peripheral nerve regeneration.

Clinical and experimental features of MuSK antibody positive MG in Japan

We investigated the presence of antibodies (Abs) against muscle-specific tyrosine kinase (MuSK) in Japanese myasthenia gravis (MG) patients. MuSK Abs were found in 23 (27%) of 85 generalized seronegative MG (SNMG) patients but not in any of the ocular MG patients. MuSK Ab-positive patients were characterized as having female dominance (M:F, 5:18), age range at onset 18 to 72 (median 45) years old, and prominent oculobulbar symptoms (100%) with neck (57%) or respiratory (35%) muscle weakness. Limb muscle weakness was comparatively less severe (52%), thymoma absent. Most patients had good responses to simple plasma exchange and steroid therapy. MuSK IgG from all 18 patients was exclusively the IgG 4 subclass and bound mainly with the MuSK Ig 1-2 domain. Serial studies of 12 individuals showed a close correlation between the variation in MuSK Ab titers and MG clinical severity (P = 0.01 by Kruskal-Wallis). MuSK Ab titers were sharply decreased in patients who had a good response to early steroid therapy or simple plasma exchange, but there was no change, or a rapid increase on exacerbation after thymectomy. Measurement of MuSK Ab titers aids in the diagnosis of MG and the monitoring of clinical courses after treatment.