Br-DIF-1 accelerates dimethyl sulphoxide-induced differentiation of P19CL6 embryonic carcinoma cells into cardiomyocytes

BACKGROUND AND PURPOSE

Stem cell transplantation therapy is a promising option for treatment of severe ischaemic heart disease. Dimethyl sulphoxide (DMSO) differentiates P19CL6 embryonic carcinoma cells into cardiomyocyte-like cells, but with low differentiation capacity. To improve the degree of this differentiation, we have assessed several derivatives of the differentiation-inducing factor-1 (DIF-1), originally found in the cellular slime mould Dictyostelium discoideum, on P19CL6 cells.

EXPERIMENTAL APPROACH

P19CL6 cells were cultured with each derivative and 1% DMSO for up to 16 days. Differentiation was assessed by measuring the number of beating and non-beating aggregates, and the expression of genes relevant to cardiac tissue. The mechanism of action was investigated using a T-type Ca(2+) channel blocker.

KEY RESULTS

Of all the DIF-1 derivatives tested only Br-DIF-1 showed any effects on cardiomyocyte differentiation. In the presence of 1% DMSO, Br-DIF-1 (0.3-3 µM) significantly and dose-dependently increased the number of spontaneously beating aggregates compared with 1% DMSO alone, by day 16. Expression of mRNA for T-type calcium channels was significantly increased by Br-DIF-1 + 1% DMSO compared with 1% DMSO alone. Mibefradil (a T-type Ca(2+) channel blocker; 100 nM) and a small interfering RNA for the T-type Ca(2+) channel both significantly decreased the beating rate of aggregates induced by Br-DIF-1 + 1% DMSO.

CONCLUSIONS AND IMPLICATIONS

Br-DIF-1 accelerated the differentiation, induced by 1% DMSO, of P19CL6 cells into spontaneously beating cardiomyocyte-like cells, partly by enhancing the expression of the T-type Ca(2+) channel gene.

Endoscopic management of malignant biliary obstruction by means of covered metallic stents: primary stent placement vs. re-intervention

BACKGROUND AND STUDY AIMS

Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Occlusion of covered metallic stents now occurs in about half of all patients with malignant biliary strictures. The removal of metallic stents followed by placement of a second stent has been attempted, but outcomes remain controversial. The aim of the current study was to evaluate the effectiveness and safety of the primary placement and secondary placement (re-intervention) of covered metallic stents and to assess the feasibility and safety of stent removal.

PATIENTS AND METHODS

The study included 186 patients with unresectable malignant biliary strictures who underwent primary stent placement between October 2001 and March 2010.  Covered biliary self-expandable metal stents (SEMSs) were removed in 39 of these patients, and 36 underwent re-intervention. The patency times, occlusion rates of the first stent and re-intervention, success rates of stent removal, and complications were investigated.

RESULTS

Covered SEMSs were placed in 186 patients. The median patency time of the first stent was 352 days. Stent occlusion occurred in 48.9 % of the patients and was mainly caused by debris or food residue (37 %), dislocation (19 %), and migration with hyperplasia (19 %). Stent removal was attempted in 50 patients and was successful without complication in 39 (78 %). Most of the patients in whom stent removal was unsuccessful had migration with hyperplasia. The median patency time of the second stent was 263 days. The stent patency time did not significantly differ between the first and the second stent.

CONCLUSIONS

Covered SEMSs could be safely removed at the time of stent occlusion. Patency rates were similar for initial stent placement and re-intervention.

Phylogenetic study of the species within the family Streptomycetaceae

Species of the genus Streptomyces, which constitute the vast majority of taxa within the family Streptomycetaceae, are a predominant component of the microbial population in soils throughout the world and have been the subject of extensive isolation and screening efforts over the years because they are a major source of commercially and medically important secondary metabolites. Taxonomic characterization of Streptomyces strains has been a challenge due to the large number of described species, greater than any other microbial genus, resulting from academic and industrial activities. The methods used for characterization have evolved through several phases over the years from those based largely on morphological observations, to subsequent classifications based on numerical taxonomic analyses of standardized sets of phenotypic characters and, most recently, to the use of molecular phylogenetic analyses of gene sequences. The present phylogenetic study examines almost all described species (615 taxa) within the family Streptomycetaceae based on 16S rRNA gene sequences and illustrates the species diversity within this family, which is observed to contain 130 statistically supported clades, as well as many unsupported and single member clusters. Many of the observed clades are consistent with earlier morphological and numerical taxonomic studies, but it is apparent that insufficient variation is present in the 16S rRNA gene sequence within the species of this family to permit bootstrap-supported resolution of relationships between many of the individual clusters.

Fine needle aspiration using forward-viewing endoscopic ultrasonography

BACKGROUND AND STUDY AIM

A prototype forward-viewing instrument has been developed for therapeutic endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA). We had the opportunity to use this forward-viewing echo endoscope and to study its clinical usefulness, mainly for diagnostic EUS-FNA.

PATIENTS AND METHODS

The prototype forward-viewing echo endoscope was used for 15 months between November 2006 and March 2010, in a study group comprising 47 consecutive patients. Diagnostic EUS-FNA was done in 38 patients and the diagnostic accuracy of the forward-viewing device was compared with that from an oblique-viewing echo endoscope in reference patients who were matched by disease and puncture route. Therapeutic EUS was done in nine patients (pseudocyst drainage in six; celiac ganglia neurolysis, biliary drainage, and pancreatic duct drainage in one each).

RESULTS

Diagnostic EUS-FNA provided a correct diagnosis in 97.4 % (37/38 patients), which was not significantly different from the 94.7 % (36/38) in the reference patients. Lesions considered difficult to access with an oblique-viewing scope, such as those located at the fornix, or the head of the pancreas, or associated with strictures, were easily punctured, as were those located at the body or tail of the pancreas or at the porta hepatis. Treatment was successful in all nine patients who underwent therapeutic EUS procedures. None of the 47 patients had any complications.

CONCLUSIONS

A forward-viewing echo endoscope that allows target sites to be punctured more perpendicularly with minimal effort, can be used for diagnostic EUS-FNA and this may be advantageous, depending on the site of target lesions.

Expression and localisation of calbindin D28k in all intestinal segments of the laying hen

1. The aim of the present study was to investigate expression and localisation of a 28-kDa calcium-binding protein (CaBP-D28k) related to active calcium (Ca) absorption, in the entire intestine of egg-laying hens. 2. Western blotting analysis showed that the entire intestine expressed CaBP-D28k to the following degree: duodenum > jejunum > caecum > ileum > colon. Immunohistochemistry showed strong CaBP-D28k localisation in enterocytes along the villus tip-crypt axis in the duodenum and in villus tips in the caecum and colon. The jejunum and ileum had moderate localisation with respect to the number of immunoreactive cells and staining intensity. 3. These results suggest that laying hens actively absorb Ca in both the large and small intestines.

Interleukin-6 and silent cerebral infarction in hemodialysis patients: a cross-sectional study

BACKGROUND

In patients with chronic renal failure undergoing hemodialysis (HD), silent cerebral infarctions (SCI) are associated with high mortality. Levels of interleukin-6 (IL-6) increase with renal dysfunction and may be a novel predictor for cerebrovascular events. We tested the hypothesis that increased IL-6 levels correlate with the occurrence of SCI in HD patients.

METHODS

Using cranial magnetic resonance imaging findings, we divided 50 Japanese patients undergoing HD into two groups: with SCI (60 ± 7 years, mean ± SD, n = 27) and without SCI (60 ± 6 years, n = 23). We compared the gender, body mass index, metabolic profiles, IL-6 levels, and smoking habits between the two groups.

RESULTS

We made the following observations: (i) The prevalence of diabetes or hypertension did not differ between the two groups, (ii) the level of IL-6 was higher in the with-SCI group than in the without-SCI group (P < 0.0001), (iii) the proportion of smokers was higher in the with-SCI group (P < 0.05), (iv) plasma level of high-density lipoprotein cholesterol was lower, whilst uric acid level was higher, in the with-SCI group (P < 0.05 and P < 0.05, respectively), and (v) multiple logistic regression analysis identified IL-6 levels as being significantly associated with the presence of SCI (odds ratio 3.13, 95% CI = 1.42-7.89, P < 0.0001).

CONCLUSIONS

This study indicates that patients with chronic renal failure who are maintained on HD exhibit an increased prevalence of SCI and that IL-6 is significantly associated with the presence of SCI in HD patients.

The change in characteristics of microcrystalline cellulose during wet granulation using a high-shear mixer

The objective of this study was to investigate the mechanism of hard granule formation and to demonstrate the applicability of X-ray diffraction methods for studying the polymeric pharmaceutical excipients. Using a high-shear mixer, microcrystalline cellulose (MCC) was granulated with water as the granulating liquid. The hardness of the MCC granules increased with granulation time and the amount of water added. The specific surface area measured by the N2 adsorption method was reduced during the process. Crystallite size of cellulose, calculated by Scherrer's equation adapted for wide angle X-ray diffraction method, decreased with granulation time and with increasing amounts of water added. Debye plots for X-ray small scattering patterns suggested that the average magnitude of the continuous solid region in MCC granules became significantly greater, whereas the specific surface area of the MCC granules, calculated from Debye plots, became smaller in comparison with that of intact MCC. These findings suggested that the long-chain structures in MCC were disrupted, resulting in smaller units with shorter chain lengths due to the strong shear force of the impeller. These smaller units then form a network within the granules. Thus, MCC granules are strengthened with longer granulation time and greater amounts of water, resulting in a more intricate network. The change in MCC chain length and physical structure can be experimentally detected using the small-angle X-ray scattering and wide-angle powder X-ray diffraction methods.

Spin configuration in the 1/3 magnetization plateau of azurite determined by NMR

High magnetic field (63,65)Cu NMR spectra were used to determine the local spin polarization in the 1/3 magnetization plateau of azurite, Cu3(CO3)(2)(OH)(2), which is a model system for the distorted diamond antiferromagnetic spin-1/2 chain. The spin part of the hyperfine field of the Cu2 (dimer) sites is found to be field independent, negative and strongly anisotropic, corresponding to approximately 10% of fully polarized spin in a d orbital. This is close to the expected configuration of the quantum plateau, where a singlet state is stabilized on the dimer. However, the observed nonzero spin polarization points to some triplet admixture, induced by strong asymmetry of the diamond bonds J1 and J3.

Histopathology of the ruptured pulmonary artery aneurysm in a patient with Behçet's disease

OBJECTIVE

Vascular involvement (vasculo-Behçet's disease) is relatively common in Behçet's disease. Although pulmonary artery aneurysm (PAA) is rare, it is the most serious and sometimes fatal complication. However, the mechanism of the development of PAA is unclear. In the present study, we carried out immunohistological examination of the ruptured pulmonary aneurysm in a patient with vasculo-Behçets disease.

METHODS

Light microscopic examination was carried out on paraffin-embedded sections of autopsied pulmonary arteries of a Behçet's disease patient who died of the rupture of the left pulmonary artery aneurysm.

RESULTS

Histopathology of the ruptured aneurysm revealed the formation of thrombus and recanalization. In addition, there was proliferation of small vessels in the vascular wall, as if the recanalization was extended to the vascular wall. Of note, marked perivascular cuffing of mononuclear cells, consisting of CD45RO+ T cells and CD68+ monocytes, were observed around the recanalizing capillaries as well as around the proliferating small vessels in the wall of the pulmonary artery. Of note, pericapillary infiltration of CD20+ B cells was noted exclusively in the vascular wall. The ruptured portion of the aneurysm lacks the lamina elastica, indicating that the aneurysm was so called pseudo-aneurysm.

CONCLUSION

It is likely that the first event might be the formation of inflammatory thrombus in the pulmonary artery. During the process of recanalization of the thrombus, the basic inflammatory process of Behçet's disease caused marked angiogenesis as well as perivascular cuffing of inflammatory cells in the thrombus and the wall, leading to fragility of the wall.