Knockdown of the Shwachman-Diamond syndrome gene, SBDS, induces galectin-1 expression and impairs cell growth

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by exocrine pancreatic insufficiency and bone marrow failure. The depletion of SBDS protein by RNA interference has been shown to cause inhibition of cell proliferation in several cell lines. However, the precise mechanism by which the loss of SBDS leads to inhibition of cell growth remains unknown. To evaluate the impaired growth of SBDS-knockdown cells, we analyzed Epstein-Barr virus-transformed lymphoblast cells (LCLs) derived from two patients with SDS (c. 183_184TA > CT and c. 258 + 2 T > C). After 3 days of culture, the growth of LCL-SDS cell lines was considerably less than that of control donor cells. By annealing control primer-based GeneFishing PCR screening, we found that galectin-1 (Gal-1) mRNA expression was elevated in LCL-SDS cells. Western blot analysis showed that the level of Gal-1 protein expression was also increased in LCL-SDS cells as well as in SBDS-knockdown 32Dcl3 murine myeloid cells. We confirmed that recombinant Gal-1 inhibited the proliferation of both LCL-control and LCL-SDS cells and induced apoptosis (as determined by annexin V-positive staining). These results suggest that the overexpression of Gal-1 contributes to abnormal cell growth in SBDS-deficient cells.

Superconducting vortices carrying a temperature-dependent fraction of the flux quantum

Magnetic field penetrates type-II bulk superconductors by forming quantum vortices that enclose a magnetic flux equal to the magnetic flux quantum. The flux quantum is a universal quantity that depends only on fundamental constants. Here we investigate isolated vortices in the hole-overdoped Ba_1-xK_xFe₂As₂ (x = 0.77) by using scanning superconducting quantum interference device (SQUID) magnetometry. In many locations, we observed vortices that carried only part of a flux quantum, with a magnitude that varied continuously with temperature. We interpret these features as quantum vortices with non-universally quantized (fractional) magnetic flux whose magnitude is determined by the temperature-dependent parameters of a multiband superconductor. The demonstrated mobility and manipulability of the fractional vortices may enable applications in fluxonics-based computing.

Microscopic Imaging Homogeneous and Single Phase Superfluid Density in UTe_{2}

Odd-parity superconductor UTe_{2} shows spontaneous time-reversal symmetry breaking and multiple superconducting phases, which imply chiral superconductivity, but only in a subset of samples. Here we microscopically observe a homogeneous superfluid density n_{s} on the surface of UTe_{2} and an enhanced superconducting transition temperature near the edges. We also detect vortex-antivortex pairs even at zero magnetic field, indicating the existence of a hidden internal field. The temperature dependence of n_{s}, determined independent of sample geometry, does not support point nodes along the b axis for a quasi-2D Fermi surface and provides no evidence for multiple phase transitions in UTe_{2}.

Discovery of FXR/PPARγ dual partial agonist

Farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR)γ are nuclear receptor 1 superfamily of transcription factors. FXR and PPARγ agonists have been individually investigated in clinical trial of anti-diabetic agents in the patients with nonalcoholic fatty liver disease (NAFLD). Regarding recent agonist development, the partial agonists for FXR and PPARγ are drawing attention from the standpoint of avoiding overactive responses caused by full agonists. In this article, we report that 18 with a benzimidazole scaffold possesses FXR/PPARγ dual partial agonistic activity. In addition, 18 shares the ability to reduce cyclin-dependent kinase 5-mediated phosphorylation of PPARγ-Ser273 and the metabolic stability in mouse liver microsome assay. To date, there are no published reports on FXR/PPARγ dual partial agonists with biological profiles similar to 18. Thus, the analog would be a feasible candidate as an unprecedented approach to NAFLD associated with type 2 diabetes mellitus.

Hyodeoxycholic Acid (HDCA) Prevents Development of Dextran Sulfate Sodium (DSS)-Induced Colitis in Mice: Possible Role of Synergism between DSS and HDCA in Increasing Fecal Bile Acid Levels

Secondary bile acids (SBAs) with high hydrophobicity are abundant in the colonic lumen. However, both aggravating and protective roles of SBAs have been proposed in the pathogenesis of inflammatory bowel diseases (IBDs). We observed that oral administration of hyodeoxycholic acid (HDCA), a hydrophilic bile acid, prevented the development of dextran sulfate sodium (DSS)-induced colitis in mice. We then examined the individual effects of DSS and HDCA as well as their combined effects on fecal bile acid profile in mice. HDCA treatment increased the levels of most of fecal bile acids, whereas DSS treatment had limited effects on the levels of fecal bile acids. The combined treatment with DSS and HDCA synergistically increased the levels of fecal chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA) in feces, which are potent activators of the farnesoid X receptor (FXR) and Takeda G-protein-coupled receptor 5 (TGR5). The overall hydrophobicity of fecal bile acids was not modified by any treatments. Our data suggest that the preventive effect of HDCA on DSS-induced colitis in mice is due to the synergism between DSS and HDCA in increasing the levels of the fecal bile acids with potencies to activate FXR and TGR5.

Dual Agonist of Farnesoid X Receptor and Takeda G Protein-Coupled Receptor 5 Inhibits Hepatitis B Virus Infection In Vitro and In Vivo

BACKGROUND AND AIMS

Chronic HBV infection is a major health problem worldwide. Currently, the first-line treatment for HBV is nucleos(t)ide analogs or interferons; however, efficient therapeutic approaches that enable cure are lacking. Therefore, anti-HBV agents with mechanisms distinct from those of current drugs are needed. Sodium taurocholate cotransporting polypeptide (NTCP) was previously identified as an HBV receptor that is inhibited by several compounds. Farnesoid X receptor (FXR) activation also inhibits NTCP function.

APPROACH AND RESULTS

In this study, we investigated the inhibitory effect of bile acid (BA) derivatives-namely obeticholic acid (OCA), 6α-ethyl-24-nor-5β-cholane-3α,7α,23-triol-23 sulfate sodium salt (INT-767; a dual agonist of FXR and Takeda G protein-coupled receptor [TGR5]), and 6α-ethyl-23(S)-methyl-cholic acid (INT-777; a TGR5 agonist)-3-(2,6-dichlorophenyl)-4-(3'-carboxy-2-chlorostilben-4-yl)oxymethyl-5-isopropylisoxazole (GW4064; a FXR agonist), cyclosporin A, and irbesartan. OCA and INT-777 suppressed HBV infection in HepG2-human NTCP-C4 cells. Interestingly, INT-767 showed potent inhibition by attaching to HBV particles rather than binding to NTCP. As an entry inhibitor, INT-767 was stronger than various natural BAs. Furthermore, in chimeric mice with humanized liver, INT-767 markedly delayed the initial rise of HBsAg, HBeAg, and HBV DNA and reduced covalently closed circular DNA. The strong inhibitory effect of INT-767 may be due to the cumulative effect of its ability to inhibit the entry of HBV and to stimulate FXR downstream signaling, which affects the postentry step.

CONCLUSIONS

Our results suggest that BA derivatives, particularly INT-767, are prospective candidate anti-HBV agents. Clarifying the underlying mechanisms of BA derivatives would facilitate the development of anti-HBV agents.

Design and identification of a new farnesoid X receptor (FXR) partial agonist by computational structure-activity relationship analysis: Ligand-induced H8 helix fluctuation in the ligand-binding domain of FXR may lead to partial agonism

Farnesoid X receptor (FXR) controls gene-expression relevant to various diseases including nonalcoholic steatohepatitis and has become a drug target to regulate metabolic aberrations. However, some side effects of FXR agonists reported in clinical development such as an increase in blood cholesterol levels incentivize the development of partial agonists to minimize side effects. In this study, to identify a new partial agonist, we analyzed the computational structure-activity relationship (SAR) of FXR agonists previously developed in our laboratories using molecular dynamics simulations. SAR analysis showed that fluctuations in the H8 helix, by ligand binding, of the ligand-binding domain (LBD) of FXR may influence agonistic activity. Based on this observation, 6 was newly designed as a partial agonist and synthesized. As a result of biological evaluations, 6 showed weak agonistic activity (40.0% relative agonistic activity to the full-agonist GW4064) and a potent EC₅₀ value (55.5 nM). The successful identification of the new potent partial agonist 6 suggested that helix fluctuation in the LBD induced by ligands could be one way to develop partial agonists.

Discovery of Orally Active and Nonsteroidal Farnesoid X Receptor (FXR) Antagonist with Propensity for Accumulation and Responsiveness in Ileum

We describe the discovery of analog 15 (FLG249), which is an orally active and nonsteroidal farnesoid X receptor (FXR) antagonist in mice with unique profiles, such as a propensity for ileum distribution and the significant control in the expression level of three FXR target genes in mouse ileum. Key design features incorporated in 15 were the introduction of metabolically stable groups in potent and metabolically labile antagonist 9. Our pursuit ultimately identified FXR antagonist 15, which has enabled its assessment in a drug discovery program.

Aortic annular enlargement techniques using an original patch for prosthetic valve endocarditis

Background

Prosthetic valve endocarditis (PVE) is a serious complication, and it is difficult to treat marked adhesion and infectious tissue.

Case presentation

There were four patients with aortic PVE, whose ages ranged from 59 to 80 years. In all patients, transoesophageal echocardiography revealed periannular abscess formation. We applied aortic annular enlargement techniques using a composite three-layer patch to repair the defects after radical debridement of the abscesses, and then replaced the prosthetic valves on the reconstructed annuli. All patients received antibiotics after surgery and recovered well without recurrence.

Conclusions

The aortic annular enlargement techniques provided a good field of vision at the complicated annulus, and our original patch was useful for repairing the aortic annulus and its surrounding apparatus.

Synthesis of Novel Farnesoid X Receptor Agonists and Validation of Their Efficacy in Activating Differentiation of Mouse Bone Marrow-Derived Mesenchymal Stem Cells into Osteoblasts

The modulators of farnesoid X receptor (FXR), a bile acid receptor, regulate various biological processes including bile acid metabolism, and are associated with the control of fatty liver and osteoporosis. Thus, the control of FXR activity and development of FXR modulators are critical not only for research, but also for clinical application. In this study, we synthesized novel FXR agonists 1–4 possessing isoxazole and N-substituted benzimidazole moieties, and compared their effects on osteoblast differentiation with the known FXR agonists, chenodeoxycholic acid and a synthetic compound, GW4064. Two (3 and 4) of the four novel FXR agonists 1–4 showed high specificities for FXR. Computer-assisted modeling suggested that the binding of the FXR agonist 3 with ligand binding domain of FXR was similar to GW4064. FXR was expressed in mouse bone marrow-derived mesenchymal stem cell (MSC)-like ST2 cells (ST-2 MSCs). The FXR agonists activated the BMP-2-induced differentiation of ST-2 MSCs into osteoblasts and enhanced the expression of RUNX2. Moreover, the potency of the FXR agonist 3 was comparable to GW4064 in promoting osteoblast differentiation of ST-2 MSCs. These results indicate that FXR activation enhanced the BMP-2-induced differentiation of MSCs into osteoblasts through activating RUNX2 expression. FXR could be a potential therapeutic target for the treatment of bone diseases such as osteoporosis.

Nonacidic Chemotype Possessing N-Acylated Piperidine Moiety as Potent Farnesoid X Receptor (FXR) Antagonists

Farnesoid X receptor (FXR) plays a major role in the control of cholesterol metabolism. Antagonizing transcriptional activity of FXR is an effective means to treat the relevant metabolic syndrome. Some of antagonists so far have the charged functions; however, they may negatively affect the pharmacokinetics. We describe herein a structure-activity relationship (SAR) exploration of nonacidic FXR antagonist 6 focusing on two regions in the structure and biological evaluation of nonacidic 10 with the characteristic N-acylated piperidine group obtained from SAR studies. As the robust affinity to FXR is feasible with our nonacidic analogue, 10 is among the most promising candidates for in vivo testing.

Molecular and morphological analyses revealed a cryptic species of dojo loach Misgurnus anguillicaudatus (Cypriniformes: Cobitidae) in Japan

Although it has been reported that populations of the Japanese dojo loach Misgurnus anguillicaudatus (Cypriniformes: Cobitidae) belong to two distinct mitochondrial (mt)DNA (Type I and Type II), the taxonomic status of the species remains unresolved. To address this question, nuclear DNA and morphological analyses were performed on M. anguillicaudatus population in the Nakaikemi Wetland, where Type I and Type II lineages are sympatric. Results suggest the existence of a cryptic species (Type I) within the Japanese dojo loach.

Magnetoelectrical control of nonreciprocal microwave response in a multiferroic helimagnet

The control of physical properties by external fields is essential in many contemporary technologies. For example, conductance can be controlled by a gate electric field in a field effect transistor, which is a main component of integrated circuits. Optical phenomena induced by an electric field such as electroluminescence and electrochromism are useful for display and other technologies. Control of microwave propagation is also important for future wireless communication technology. Microwave properties in solids are dominated mostly by magnetic excitations, which cannot be easily controlled by an electric field. One solution to this problem is to use magnetically induced ferroelectrics (multiferroics). Here we show that microwave nonreciprocity, that is, different refractive indices for microwaves propagating in opposite directions, could be reversed by an external electric field in a multiferroic helimagnet Ba₂Mg₂Fe₁₂O₂₂. This approach offers an avenue for the electrical control of microwave properties.

Control of microwave propagation is important for future communication technology. Here, Iguchi et al. report the reversal of microwave nonreciprocity by an external electric field in a multiferroic helimagnet Ba₂Mg₂Fe₁₂O₂₂.

Discovery and optimization of benzimidazole derivatives as a novel chemotype of farnesoid X receptor (FXR) antagonists

We describe here a novel chemotype with substituted benzimidazole scaffold for nonsteroidal farnesoid X receptor (FXR) antagonists starting from the identification of a screening hit, BB-4. Structure diversity in four regions A-D of BB-4 or 1 is discussed. In particular, regions A and C had an effect on an antagonism against FXR as demonstrated by the derivatives represented by 7 and 15, respectively. Thus, compound 19 arising from the combination of regions A and C underscored an important fact on antagonism against FXR, also showing the reduced small heterodimer partner and the increased cholesterol 7α-hydroxylase expression levels.

Japanese Direct Investment and its Impact on Migration in the ASEAN 4

Although the manufacturing sector's share of employment is still small in ASEAN-4 countries, the development of manufacturing, especially labor-intensive industries, will be indispensable for absorbing part of the increase in labor force. In these countries, Japanese direct investment (JDI) has been more highly concentrated in the manufacturing sector than JDI in other regions. The Japanese “New Asian Industrial Development (AID) Plan” is a comprehensive economic cooperation package, which supports the introduction of JDI and the promotion of exports in ASEAN-4 countries. JDI and AID may, in turn, help alleviate the domestic labor market situation and reduce the incentive for workers of ASEAN-4 countries to migrate to work overseas.

Effectiveness of third-line chemotherapy in recurrent ovarian cancer patients

OBJECTIVE

Despite recent advances in the treatment of recurrent ovarian cancer, little evidence exists describing the benefit of third- line chemotherapy. The present authors previously reported that the treatment-free interval (TFI) after second-line chemotherapy may predict a survival benefit of third-line chemotherapy, however the length of TFI was uncertain due to limited cases. In this study, the authors evaluated the length of TFI, which is correlated with the effectiveness of third-line chemotherapy and a prognostic factor of third-line chemotherapy.

MATERIALS AND METHODS

The authors reviewed the medical records of 85 women with recurrent ovarian cancer who received third-line chemotherapy after a paclitaxel/carboplatin (PC) regimen as first-line chemotherapy.

RESULTS

The response rate [complete response (CR) + partial response (PR)] and clinical benefit rate [(CBR): CR + PR + stable disease (SD)] during the TFI after second-line chemotherapy for 0-3 months, 3-6 months, and 6-12 months and ≥ 12 months were 9.8%, 0%, 0%, 43.8% and 15.7%, 50%, 66.7%, and 93.8%, respectively. The median overall survival (OS) from the onset of third-line chemotherapy was longer for TFI ≥ 3 months than for TFI 0-3 months (795 days vs. 281 days, p < 0.001). Finally, according to univariate (HR = 0.256; p < 0.001) and multivariate (HR = 0.264; p < 0.001) analyses, TFI was the independent significant prognostic factor for OS.

CONCLUSIONS

TFI less than three months after second-line chemotherapy may predict little survival benefit of third-line chemotherapy.

Admission hyperglycemia causes infarct volume expansion in patients with ICA or MCA occlusion: association of collateral grade on conventional angiography

BACKGROUND AND PURPOSE

Hyperglycemia (HG) is associated with infarct volume expansion in acute ischaemic stroke patients. However, collateral circulation can sustain the ischaemic penumbra and limit the growth of infarct volume. The aim of this study was to determine whether the association between HG and infarct volume expansion is dependent on collateral circulation.

METHODS

We performed a retrospective analysis of 93 acute ischaemic stroke patients with internal carotid artery or middle cerebral artery occlusion within 24 h of onset were retrospectively studied. HG was diagnosed in patients with an admitting blood glucose value ≥140 mg/dl. Angiographic collateral grade 0-1 was designated as poor collateral circulation and grade 2-4 as good collateral circulation. Infarct volume was measured at admission and at again within 7 days using diffusion-weighted magnetic resonance images.

RESULTS

Among 34 patients with poor collateral grade, the change in infarct volume was significantly greater in the HG group than in the non-HG group (106.0 ml vs. 22.7 ml, P = 0.002). Among the 59 patients with good collateral circulation, the change in infarct volume was greater in the HG group than in the non-HG group (53.3 ml vs. 10.9 ml, P = 0.047). Multiple regression analysis indicated that admission HG (P = 0.004), baseline National Institutes of Health Stroke Scale score (P = 0.018), and poor collateral circulation (P = 0.040) were independently associated with infarct volume expansion.

CONCLUSIONS

Infarct volume expansion was greater in individuals with HG on admission regardless of collateral circulation status.

Plasma brain natriuretic peptide predicts death during hospitalization in acute ischaemic stroke and transient ischaemic attack patients with atrial fibrillation

BACKGROUND AND PURPOSE

atrial fibrillation (AF) is the most powerful predictor of early death in patients with acute ischaemic stroke. We investigated whether the plasma brain natriuretic peptide (BNP) level on admission can serve as a biological marker of in-hospital death in acute ischaemic stroke and transient ischaemic attack (TIA) patients with AF.

METHODS

we prospectively enrolled ischaemic stroke and TIA patients with AF within 24 h of onset and measured plasma BNP on admission. Patients were divided into two groups: the deceased group, who died during hospitalization, and the survival group. The factors associated with in-hospital death were investigated by multivariate logistic regression analysis.

RESULTS

a total of 221 patients with AF were enrolled. Death occurred in 24 (10.9%) patients. The mean ± SD of the plasma BNP level of the deceased group was significantly higher than that of the survival group (714.1 ± 716.3 vs. 320.0 ± 380.7 pg/ml, P < 0.0001). The optimal cutoff level, sensitivity, and specificity of BNP levels to distinguish the deceased group from the survival group were 320 pg/ml, 79.2, and 69.0%, respectively. Multivariate logistic regression analysis demonstrated that age per 10 years increase (OR, 3.56; 95% CI, 1.728-7.346, P = 0.0006), internal carotid artery occlusion (OR, 10.20; 95% CI, 2.525-41.177, P = 0.0011), NIHSS score of >17 (OR, 4.68; 95% CI, 1.137-19.286, P = 0.0325), and plasma BNP level of > 320 pg/ml (OR, 4.74; 95% CI, 1.260-17.800, P = 0.0213) were independent factors associated with in-hospital death.

CONCLUSION

the plasma BNP level on admission can predict in-hospital death in acute ischaemic stroke and TIA patients with AF.

Structure-activity relationship of bile alcohols as human farnesoid X receptor agonist

FXR (farnesoid X receptor) is a bile acid-activated nuclear receptor that regulates not only the biosynthesis and enterohepatic circulation of bile acids, but also triglyceride, cholesterol and glucose metabolism. FXR-mediated signaling pathways have become promising novel drug targets for the treatment of common metabolic and hepatic diseases. With the aim of uncovering novel modulators of FXR and further elucidating the molecular basis of FXR activation, we investigated the structure-activity relationships of a variety of naturally occurring sterols structurally related to bile acids in terms of their FXR agonist activity. Here, we report that the ability of bile alcohols to activate FXR varied with the position and number of hydroxyl groups existing in the steroid side chain of bile alcohols. In addition, we showed that the shortening of the steroid side chain of bile acids as well as bile alcohols resulted in a decline of the ability of these agents to activate FXR. Thus, we provide new insights into the structure-activity relationships of bile acids and bile alcohols as FXR agonists.

Bile alcohols function as the ligands of membrane-type bile acid-activated G protein-coupled receptor

TGR5 is a G protein-coupled receptor that is activated by bile acids, resulting in an increase in cAMP levels and the subsequent modulation of energy expenditure in brown adipose tissue and muscle. Therefore, the development of a TGR5-specific agonist could lead to the prevention and treatment of various metabolic disorders related to obesity. In the present study, we evaluated the ability of bile alcohols, which are structurally and physiologically similar to bile acids and are produced as the end products of cholesterol catabolism in evolutionarily primitive vertebrates, to act as TGR5 agonists. In a cell-based reporter assay and a cAMP production assay performed in vitro, most bile alcohols with a side chain containing hydroxyl group(s) were highly efficacious agonists for TGR5 comparable to its most potent ligand in the naturally occurring bile acid, lithocholic acid. However, the abilities of the bile alcohols to activate TGR5 varied with the position and number of the hydroxyl substituent in the side chain. Additionally, the conformation of the steroidal nucleus of bile alcohols is also important for its activity as a TGR5 agonist. Thus, we have provided new insights into the structure-activity relationships of bile alcohols as TGR5 agonists.

Development of special rotor for centrifugal separation of isotopes in solid pure metals

A prototype rotor with two grooves for the multistage centrifugal isotope separation in solid state was developed to test a new idea. This idea is based on the sedimentation of constitutional atoms in solid. In the performance test using indium specimen, it is verified that the developed rotor can receive all injected molten-indium droplets from an automatic raw-material feeding system even at the high rotational speed of 97,000 rpm without the loss of rotational stability, and the received indium specimens can be transferred in/between two grooves through the plastic flow under the influence of strong centrifugal force even in the solid state. The isotope ratio of centrifuged indium specimens was analyzed employing the secondary ion mass spectrometry, and it is confirmed that intended isotope separation by the centrifugation is realized in the solid state. The developed rotor can be used to perform the isotope separation on at least solid metals under the conditions of up to 400 degrees C in specimen temperature and 0.4x10(6)g in centrifugal force field.

Microembolic signals at 48 hours after stroke onset contribute to new ischaemia within a week

BACKGROUND AND AIMS

We investigated whether new ischaemic lesions (NIL) on follow-up diffusion weighted magnetic resonance imaging (DWI) are associated with microembolic signals (MES) within 24 h or at 48 h after stroke onset.

METHODS

Patients had acute ischaemic stroke and were studied within 24 h of onset. Transcranial Doppler ultrasonography (TCD) was prospectively examined twice, within 24 h and at 48 h after onset. DWI was conducted twice, on admission and on day 7. NIL were defined as the presence of hyperintense lesions undetected on initial DWI.

RESULTS

125 patients were consecutively enrolled from November 2004 to March 2006. TCD detected MES in 49% within 24 h and in 29% at 48 h after onset. In 27 patients with small vessel disease, MES were found in 8 (30%) patients within 24 h and in 5 (19%) patients at 48 h after stroke onset. In contrast, in 20 patients with large vessel disease, 11 (55%) patients within 24 h and 7 (35%) at 48 h had MES. Follow-up DWI detected NIL in 28 of 125 patients (22%) and NIL were significantly more frequent in MES positive patients (42%) than in MES negative patients at 48 h (15%; p = 0.002). MES at 48 h (OR 3.9; 95% CI 1.5 to 10; p = 0.005), atrial fibrillation (OR 3.6; 95% CI 1.3 to 11; p = 0.013) and arterial lesions (OR 4.3; 95% CI 1.5 to 12; p = 0.007) represented independent factors for NIL.

CONCLUSION

The presence of MES at 48 h, atrial fibrillation and arterial lesions were associated with recurrence of cerebral ischaemia on DWI.

Two-stage formation model and helicity of gold nanowires

A model for the formation of helical multishell gold nanowires is proposed and is confirmed with quantum mechanical molecular dynamics simulations. The model can explain the magic number of the helical gold nanowires in the multishell structure. The reconstruction from ideal nonhelical to realistic helical nanowires consists of two stages: dissociations of atoms on the outermost shell from atoms on the inner shell and slip deformations of atom rows generating (111)-like structure on the outermost shell. The elementary processes are governed by competition between energy loss and gain by s and d electrons together with the width of the d band. The possibility for the helical nanowires of platinum, silver, and copper is discussed.

Right-to-left shunt and lacunar stroke in patients without hypertension and diabetes

We analyzed the frequency of cardiac embolic sources in 62 patients with acute lacunar stroke vs 50 controls. In post hoc analysis, 11 patients with lacunar stroke having neither hypertension nor diabetes mellitus (non-HDM group) had a higher frequency of right-to-left shunt (RLS) (82%) than patients with risk factors for lacunar stroke. RLS was also independently associated with the non-HDM group. Thus, RLS may contribute to lacunar stroke in patients without risk factors for lacunar stroke.

Ischaemic stroke with malignancy may often be caused by paradoxical embolism

BACKGROUND

Although ischaemic stroke with malignancy occasionally occurs, the mechanisms of stroke in such cases have not been investigated in detail.

OBJECTIVE

To examine the mechanisms of ischaemic stroke with malignancy, particularly in relation to right-to-left shunt (RLS).

METHODS

Consecutive patients with ischaemic stroke within 24 h of stroke onset were prospectively studied. Contrast saline transcranial Doppler examination was carried out for all patients, to investigate the presence of RLS. When patients with stroke had RLS, deep venous thrombosis (DVT) or pulmonary embolism was assessed to diagnose paradoxical brain embolism.

RESULTS

Participants comprised 184 consecutive patients (115 men and 69 women) with a mean (standard deviation (SD)) age of 73 (11.8) years and mean (SD) National Institutes of Health Stroke Scale (NIHSS) score of 8 (7.4). RLS was detected in 32 of 184 (18%) patients. Malignancy was present in 11 (5%) patients. RLS was more frequent in patients with malignancy than in patients without malignancy (55% v 15%, respectively; p = 0.001). All six patients with RLS and malignancy displayed DVT or pulmonary embolism with severe disability (modified Rankin Scale 4-5) before stroke onset.

CONCLUSION

Paradoxical brain embolism should be considered to be an important mechanism in patients with stroke and malignancy.

Confocal endomicroscopy for the diagnosis of gastric cancer in vivo

BACKGROUND AND STUDY AIMS

Advances in endoscopy have led to imaging of the details of the gastric mucosa, but the histological diagnosis usually has to be confirmed by endoscopic biopsy. A method of confocal endomicroscopy that has recently been developed allows the observation of living cells in vivo. Several investigators have reported that the technique is of value, but there have as yet been no studies describing its application in gastric cancer.

PATIENTS AND METHODS

Twenty-seven patients with early gastric cancer underwent confocal endomicroscopy (Pentax EG-3870CIK; Pentax, Tokyo, Japan). After intravenous administration of fluorescein sodium, confocal images obtained from the normal mucosa and from cancerous lesions were interpreted by two pathologists independently and compared with the histological findings, including CD34 immunostaining of biopsy specimens or resected specimens from the same sites.

RESULTS

Fluorescein yielded high-quality confocal images of the gastric mucosa; if cancer could be targeted (59%) images were mostly graded good. The images corresponded to the hematoxylin-eosin staining of transverse sections of specimens from the same sites. In the results for the interpretation by the two pathologists, the accuracy for the diagnosis of gastric cancer was 94.2% (pathologist A), and 96.2% (pathologist B), respectively. The accuracy decreased substantially when poor images and inaccessible lesions were included.

CONCLUSIONS

Confocal endomicroscopy is useful in the diagnosis of gastric cancer but good quality images cannot always be obtained. In the future, it may allow virtual biopsy and help reduce unnecessary biopsies.