Recurrent focal segmental glomerulosclerosis following renal transplantation in Korean pediatric patients

The recurrence of focal segmental glomerulosclerosis (FSGS) in transplants is a well-known problem in pediatric renal transplantation (Tx). Recently, the race of the recipient was recognized as a major variable associated with disease recurrence. In view of this finding, we report on our single-center experience of FSGS recurrence in Korean children, an ethnically homogeneous Far East Asian population. Clinical records and renal biopsy specimens, both native and graft, were reviewed for all pediatric renal Txs (recipient age < or = 18 yr) performed at Seoul National University Hospital from 1984 to 1999. Twenty-two children with primary FSGS received 22 allografts for renal replacement. The mean age of disease onset in these patients was 5.9 yr. The grafts were from 12 living-related, six living-unrelated, and four cadaveric donors, and all recipients were immunosuppressed with cyclosporin A (CsA)-based regimens. Post-transplant recurrence of FSGS was confirmed in nine patients (41%). Long-term graft survival in recurrent and non-recurrent groups was not significantly different. Risk factor analysis showed that patients with a disease duration shorter than 48 months (odds ratio 11.7, 95% CI 1.53-89.1) and a glomerulosclerosis percentage of < 55% by renal biopsy (odds ratio 16.0, 95% CI 1.45-176) were at greater risk of disease recurrence. These results suggest that Korean children are similar to non-African-American youngsters in the USA and Europe with respect to post-transplant recurrence of FSGS. The same may be true of other Far Eastern Asian children.

K5.76Ga5.76Si10.24O32.3.4H2O, a gallosilicate with the zeolite gismondine topology

The title compound, K-GaSi-GIS, potassium gallium silicon oxide hydrate, was synthesized hydrothermally and its crystal structure was determined from data collected on a single crystal of dimensions 10 x 10 x 8 microm at a synchrotron X-ray source. The compound, which has the aluminosilicate (AlSi) zeolite gismondine (GIS) topology, Ca(4)[Al(8)Si(8)O(32)].16H(2)O, crystallizes in the tetragonal space group I4(1)/a. A disordered distribution of the framework Si/Ga sites leads to higher symmetry of the GIS-type network compared with the usual monoclinic symmetry in AlSi-GIS. Framework Ga substitution for Al in AlSi-GIS leads to substantial distortion of the crankshaft chains, reducing the effective pore dimensions and suggesting the possibility of pore-dimension control via partial framework-cation substitution.

Capsaicin inhibits the voltage-operated calcium channels intracellularly in the antral circular myocytes of guinea-pig stomach

Studies of the effect of capsaicin (CAP) on the smooth muscle contractions have shown both contraction and relaxation in various preparations. The direct effect of CAP on gastric smooth muscle itself has not yet been reported, though CAP was reported to relax the isolated guinea-pig stomach by releasing nitric oxide from the CAP-sensitive sensory neurons. Here we showed an evidence that CAP evokes a prolonged relaxation of gastric antral circular smooth muscle (CAP-induced relaxation) by blocking the voltage-operated Ca2+ channels (VOCC) from inside of the cell. CAP suppressed dose-dependently the spontaneous contractions of guinea-pig gastric circular muscle strip under the condition without neural influence (IC50 = 5.8 microM). The inhibitory effects of CAP both on the high K+ contracture induced by 50 mM K+ Tyrode solution and on the slow waves recorded using a conventional intracellular microelectrode technique were similar to those of Ca2+ channel antagonists, indicating that Ca2+ influx through the VOCC is decreased by CAP. Ca2+ channel current (I(Ba)) decreased in a concentration-dependent manner on superfusing the physiological salt solution containing various concentrations of CAP. The steady-state activation and inactivation curves of I(Ba) were not affected by the treatment with CAP. The experiment using a synthetic water-soluble analog of CAP, DA-5018 x HCl, suggested that the acting site of CAP is present in the intracellular side. Spontaneous transient outward K+ currents (STOCs) recorded at a holding potential of 0 mV were also inhibited by CAP and verapamil, Ca channel blocker. Taken together, these results indicate that CAP-induced relaxation is associated with the direct inhibitory action on the VOCC from inside of the cell.

A survey of spinal and epidural techniques in adult cardiac surgery

OBJECTIVE

To determine if a significant number of anesthesiologists are performing spinal and epidural techniques in adults undergoing cardiac surgery and if any neurologic injuries have been associated with these techniques.

DESIGN

Anonymous survey of clinical practice.

SETTING

Data collected via mail from members of the Society of Cardiovascular Anesthesiologists.

PARTICIPANTS

Attending anesthesiologists.

INTERVENTIONS

Anesthesiologists completed an anonymous survey of their use of spinal and epidural techniques in adult patients undergoing cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Of 3974 anesthesiologists, 974 (24%) responded to the questionnaire; 892 are at institutions that perform cardiac surgery. Of the 892 responders, 68 (7.6%) reported they use spinal techniques, whereas 62 (7%) reported they use epidural techniques. Nine (1%) anesthesiologists reported they use both techniques. There were no reports of neurologic complications related to the use of spinal or epidural techniques performed by the anesthesiologists responding to the survey.

CONCLUSIONS

A significant number of anesthesiologists are performing spinal and epidural techniques in adult patients undergoing cardiac surgery. Prospective, controlled trials should be performed to evaluate the benefits and risks of spinal and epidural techniques in this population.

Up-regulation of MUC5AC mRNA expression in endotoxin-induced otitis media

We investigated the expression levels of MUC5AC in endotoxin-induced otitis media with effusion (OME) in the rat using competitive polymerase chain reaction (PCR) and the morphology of middle ear mucosa using transmission electron microscopy (TEM). Experimental OME in the rat was induced after middle ear instillation of Escherichia coli lipopolysaccharides (LPS). Middle ear mucosa were obtained at 0 h, 12 h, Day 1, Day 3, Day 7 and Day 14 and reverse transcriptase (RT)-PCRs were then performed for the identification of MUC1, MUC2, MUC5AC and submandibular mucin 1 expression, followed by competitive PCRs for MUC5AC and beta2-microglobulin expression. Normal middle ear mucosa revealed no expression of mucin genes, whereas endotoxin upregulated the expression of MUC5AC mRNA between 12 h and Day 7, with maximal expression at Days 1 and 3. Middle ears treated three times with LPS upregulated more MUC5AC mRNA expression, by a factor of approximately 3.5, than those 1 day after one instillation. On TEM, dark granulated cells were observed at Day 3 after endotoxin instillation, but mixed granulated cells were seen on the ears treated three times with LPS. These results suggest that MUC5AC could be one of the major mucin genes in the middle ear mucosa related to otitis media.

Effect of biflavones of Ginkgo biloba against UVB-induced cytotoxicity in vitro

The effect of Ginkgo biloba extract on Ultraviolet B (UVB) irradiated fibroblasts was examined by using a neutral red dye uptake assay and a lactic dehydrogenase (LDH) release assay. Crude extract along with individual components, including flavone-glycosides and biflavones, were applied to cultured normal human skin fibroblasts for 12 hours, and 0, 20, 40 and 80 mJ/cm2 of UVB were irradiated. Two synthetic flavonoids, quercetin and rutin, which have polyphenol structures close to the flavonoids in Ginkgo biloba extract, were used to compare any structure-related activity under the same conditions. At the concentrations (from 0.25 to 2 mg/ml) treated with biflavone components (isoginkgetin/ginkgetin, sciadopitysin) and quercetin, high neutral red dye uptake was detected with gradual increases in UVB irradiation. The time-course release of LDH was determined as the cytotoxicity index (%) during 24 hours following a high dose UVB irradiation (200 mJ/cm2), and the pattern of this cytotoxicity index was similar to that of the neutral red dye uptake results. Sciadopitysin, isoginkgetin/ginkgetin and quercetin treatments lowered cytotoxicity indices to 50.81, 67.81 and 62.19%, respectively, compared to 95.38% for the untreated control. The antioxidant potential of biflavones of Ginkgo biloba could be explained on the basis of structure-related activity; hydroxy- and methyl-substitutions on the basic structure of these flavonoids played a role, as other reports have suggested.

Methylation in the p53 promoter is a supplementary route to breast carcinogenesis: correlation between CpG methylation in the p53 promoter and the mutation of the p53 gene in the progression from ductal carcinoma in situ to invasive ductal carcinoma

Aberrant methylation in the CpG sites located in the promoter region of several tumor suppressor genes has been reported in various types of cancers. However, the methylation status of the p53 promoter has not been clearly determined and no information is available on its role in breast cancer. The aim of the study was to determine the presence and timing of the methylation of CpG sites in the p53 promoter, in the progression from ductal carcinoma in situ to invasive cancer. We also explored the correlation between the CpG methylation of the p53 promoter and p53 mutation during the progression of breast cancer. The corresponding lesions of both the invasive and noninvasive types were microdissected in paraffin-embedded tissue of 26 breast carcinomas. Bisulfite-modified DNA sequencing for methylation status in the p53 promoter was carried out, and double-strand DNA sequencing was performed in the promoter region and exons 4 to 9 of the p53 gene. CpG site methylation in the p53 promoter was detected in three cases (11.5%). Two noninvasive and three invasive lesions harbored CpG methylation in the p53 promoter. Methylations in more than one site were observed in three lesions, all of which contained methylation in two sites. The methylated CpG sites were located near the AP1 and YY-1 binding sites and at the YY-1 binding site. The p53 mutation was not found in the lesions where methylation in p53 promoter region was evident. In 16 cases (61.5%), neither methylation nor p53 mutation was detected. We conclude that the methylation in the p53 promoter region is found in the breast cancer irrespective of the status of invasion, and that the hypermethylation in the p53 promoter region is an alternative pathway to tumorigenesis where there is no p53 gene mutation.

Sequence-specific enhancer binding protein is responsible for the differential expression of ERT/ESX/ELF-3/ESE-1/jen gene in human gastric cancer cell lines: Implication for the loss of TGF-beta type II receptor expression

Transcriptional repression of the TGF-beta type II receptor (RII) is one of the mechanisms leading to TGF-beta resistance. The newly identified epithelium-specific ets transcription factor ERT/ESX/ELF-3/ESE-1/jen binds to the TGF-beta RII promoter and induces promoter activity. The human gastric cancer cell lines, which show undetectable level of TGF-beta RII mRNA, do not express ERT mRNA. To study the molecular mechanisms of loss of ERT expression, we have cloned and characterized the human ERT promoter. DNA transfection experiments and electrophoretic mobility shift assays have revealed the existence of a distinct enhancer element (-186 to -177) which we named ESE (ERT promoter specific element). Deletion of the ESE markedly decreased expression of the target gene. ESE interacts with two distinct nuclear protein complexes, at least one of which appears to be inactivated in a cell line which does not express the ERT mRNA, compared to a cell line expressing the ERT mRNA. These results suggest the possibility that inactivation of the sequence-specific DNA binding protein to the region from -186 to -177 contributes to the loss of ERT expression, leading to the loss of TGF-beta type II receptor mRNA in human gastric cancer cell lines.

Caspase-mediated Cdk2 activation is a critical step to execute transforming growth factor-beta1-induced apoptosis in human gastric cancer cells

Although TGF-beta1, a growth inhibitor, is known to also induce apoptosis, the molecular mechanism of this apoptosis is largely undefined. Here, we identify the mechanism of TGF-beta1-induced apoptosis in SNU-16 human gastric cancer cells. Cell cycle and TUNEL analysis showed that, upon TGF-beta1 treatment, cells were initially arrested at the G1 phase and then driven into apoptosis. Of note, caspase-3 was activated in accordance with TGF-beta1-induced G1 arrest. Activated caspase-3 is targeted to cleave p21(cip1), p27(kip1), and Rb, which play important roles in TGF-beta-induced G1 arrest, into inactive fragments. Subsequently, Cdk2 was aberrantly activated due to the cleavage of p21 and p27. We found that the inhibition of Cdk2 activity efficiently blocks TGF-beta1-induced apoptosis, whereas it did not prevent caspase-3 activation or the subsequent cleavage of target proteins. In contrast, the suppression of caspase-3 activity inhibited the cleavage of target proteins, the activation of Cdk2, and the induction of apoptosis. Taken together, our results suggest that activation of caspase-3 by TGF-beta1 may initiate the conversion from G1 cell cycle arrest to apoptosis via the cleavage of p21, p27 and Rb, which in turn causes Cdk2 activation and, most significantly, Cdk2 activation as a downstream effector of caspase is a critical step for the execution of TGF-beta1-induced apoptosis.

Massive gastrointestinal bleeding from jejunal varices

We report a patient with massive gastrointestinal bleeding from jejunal varices, confirmed by emergency laparotomy. A 54-year-old woman was admitted to Chonnam National University Hospital with a 5-day history of melena with hematochezia. Fifteen years previously, she had undergone cholecystectomy for gallstone. Seven years previously, she had undergone an operation because of possible common bile duct stone. The details of this operation were not known. Upper gastrointestinal endoscopy revealed no varices in the esophagus, stomach, and proximal duodenum. Colonoscopy demonstrated black-colored blood clots throughout the colon. A technetium-99m-labeled red blood cell (RBC) scan showed active proximal small bowel bleeding. Abdominal aortic angiography revealed mesenteric varices in the upper abdomen, but no active bleeding source was recognized. Because of the patient's continued massive gastrointestinal bleeding despite medical therapy, emergency laparotomy was performed. We found evidence of micronodular cirrhosis of the liver and an apparent Roux-en-Y anastomosis. There were numerous collateral variceal vessels in the jejunal limb with the liver and abdominal wall. Segmental resection of the involved jejunum and end-to-end anastomosis were perdilated formed. Histologic examination revealed submucosal veins with mucosal erosion.

A ferric-cyanide-bridged one-dimensional dirhodium complex with (18-crown-6)potassium cations

The crystal structure of the title compound, catena-poly[bis[aqua(18-crown-6)potassium] diaqua(18-crown-6)potassium [[tetra-mu-benzoato-2:3 kappa(8)O:O'-mu-cyano-1:2 kappa(2)C:N-tetracyano-1 kappa C-irondirhodium(Rh-Rh)]-mu-cyano-1 kappa C:3' kappa N] octahydrate], [K(18-crown-6)(H(2)O)](2)[K(18-crown-6)(H(2)O)(2)][FeRh(2)(C(7)H(5)O(2))(4)(CN)(6)] x 8H(2)O, where (18-crown-6) is 1,4,7,10,13,16-hexaoxacyclooctadecane (C(12)H(24)O(6)), has been determined. Ferric cyanides connect the dirhodium units to form a one-dimensional chain compound. [K(18-crown-6-ether)(H(2)O)(2)] cations (with inversion symmetry) and [K(18-crown-6-ether)(H(2)O)] cations (in general positions) are located between the chains.

The properties of carbachol-activated nonselective cation channels at the single channel level in guinea pig gastric myocytes

We investigated the properties of carbachol (CCh)-activated nonselective cation channels (NSC(CCh)) at the single channel level in the gastric myocytes of guinea pigs using a magnified whole-cell mode or an outside-out mode. The channel activity (NPo) recorded in a magnified whole-cell mode increased with depolarization (from -120 to -20 mV) and had the half activation potential of -81 mV under the symmetrical 140 mM Cs+ condition. The single channel conductance depended upon the extracellular monovalent cations with the order of Cs+ (35 pS) > Na+ (25 pS) > Li+ (21 pS). The channel activities markedly diminished or disappeared when external Cs+ was replaced with Na+ or N-methyl-D-glucamate (NMDG+). With Cs+ and Na+ as external cations, the channel showed a monotonic increase in NPo with the increased mole fraction of Cs+ over Na+, and it had an intermediate conductance value in solution containing 67% Cs+ with 33% Na+. These data suggested that the extracellular monovalent cations regulate the whole-cell current of NSC(CCh) by modulating both the open state probability and the unitary conductance, and there is one binding site for the extracellular cations within the pore.

Genomic organization of the SLC1A1/EAAC1 gene and mutation screening in early-onset obsessive-compulsive disorder

The first genome scan conducted in early-onset obsessive-compulsive disorder used a non-parametric analysis to identify a peak in a region of chromosome 9 containing the gene SLC1A1, which codes for the neuronal and epithelial glutamate transporter EAAC1. Interaction between the glutamatergic and serotonergic systems within the striatum suggests EAAC1 as a functional candidate in OCD as well. We determined the genomic organization of SLC1A1 primarily by using primers designed from cDNA sequence to amplify from adaptor-ligated genomic DNA restriction fragments. In order to confirm SLC1A1 as a positional candidate in early-onset OCD, common single nucleotide polymorphisms (SNPs) were identified that enabled mapping of SLC1A1 within the region of the lod score peak. Based on the linkage evidence, the coding region was sequenced in the probands of the seven families included in the genome scan. No evidence was found for a functional mutation, but several SNPs were identified. Capillary electrophoresis SSCP typing of a haplotype consisting of two common SNPs within EAAC1 revealed no significant linkage disequilibrium.

Evaluation of chondromalacia of the patella with axial inversion recovery-fast spin-echo imaging

The purpose of our study was to assess the accuracy of inversion recovery-fast spin-echo (IR-FSE) imaging for the evaluation of chondromalacia of the patella. Eighty-six patients were included, they underwent magnetic resonance (MR) examination and subsequent knee arthroscopy. Medial and lateral facets of the patella were evaluated separately. Axial images were obtained by using IR-FSE (TR/TE/TI = 3000/25/150 msec; echo train length, 8; 4-mm thickness; 12-cm field of view; 512 x 256 matrix; two, number of excitations) with a 1.5-T MR machine. MR interpretation of chondromalacia was made on the basis of the arthroscopic grading system. Of a total of 172 facets graded, arthroscopy revealed chondromalacia in 14 facets with various grades (G0, 158; G1, 1; G2, 3; G3, 6; G4, 4). Sensitivity, specificity, and accuracy in the chondromalacia grades were 57.1%, 93.0%, and 90.1%, respectively. There was one false-negative case (G4) and 11 false-positive cases (G1, eight; G2, two; G3, one). Sensitivity and specificity corrected by one grade difference were improved to 85.7% and 98.1%, respectively. When cartilage changes were grouped into early (corresponding to grade 1 and 2) and advanced (grade 3 and 4) diseases, sensitivity and specificity of the early and advanced diseases were 75% and 94% and 80% and 99%, respectively. IR-FSE imaging of the knee revealed high specificity but low sensitivity for the evaluation of chondromalacia of the patella.

Effect of astaxanthin on the hepatotoxicity, lipid peroxidation and antioxidative enzymes in the liver of CCl4-treated rats

Astaxanthin is one of many carotenoids present in marine animals, vegetables and fruits. Since carotenoids are known to have antioxidant properties, we tested to determine if astaxanthin could have protective effects in the CCl4-treated rat liver by activating the antioxidant system. Astaxanthin blocked the increase of glutamate-oxalacetate transaminase (GOT) and glutamate-pyruvate transaminase (GTP) activity and thiobarbituric acid reactive substances (TBARS) in response to carbon tetrachloride (CCl4), while causing an increase in glutathione (GSH) levels and superoxide dismutase (SOD) activities in the CCl4-treated rat liver. These results suggest that astaxanthin protects liver damage induced by CCl4 by inhibiting lipid peroxidation and stimulating the cellular antioxidant system.

4d Electronic structure analysis of ruthenium in the perovskite oxides by Ru K- and L-edge XAS

The 4d electronic structure of ruthenium in the perovskite oxides, La2MRuIVO6 (M = Zn, Mg, and Li) and Ba2YRuVO6, has been investigated by the Ru K-and L-edge XANES and EXAFS analyses. Such X-ray absorption spectroscopic results clarify that the RuIV (d4) and RuV (d3) ions are stabilized in nearly regular Oh site. Comparing the Ru L-edge XANES spectra of perovskites containing isovalent ruthenium, it has been found that the t2g state is mainly influenced by A site cation, whereas the eg is mainly affected by neighboring B site cation. The experimental EXAFS spectra in the range of R < or = approximately 4.5 A are well reproduced by ab-initio calculation based on crystallographic data, which supports the long-range structure presented by Rietveld refinement.

Screening for primary hyperparathyroidism (PHPT) in clinic patients: differential diagnosis between PHPT and malignancy-associated hypercalcemia by routine blood tests

Screening for primary hyperparathyroidism (PHPT) by measurement of the serum calcium concentration detects one patient per 500-1000 individuals in Western countries, and one patient per 2500-5000 subjects in Japan. Among clinic patients, however, the presence of many false-positive cases due to malignancy-associated hypercalcemia (MAH) reduces the benefit of such screening. We evaluated a new method of screening for PHPT based on the results of routine blood tests using the hospital information system (HIS) at our hospital. This new method could distinguish PHPT from MAH. This study included 25179 blood samples in which the serum calcium (Ca), albumin (Alb), chloride (Cl) and inorganic phosphate (IP) concentrations had been measured between March, 1994 and February, 1995 at Osaka University Medical Hospital. The HIS was programmed to pick blood samples that satisfied Formula 1 [Ca(mEq/ml) > 0.3 x Alb(g/dl) + 4.1] and Formula 2 ([Cl(mEq/ml)-84] x [10 x Alb-15]/[IP(mg/dl)/3.1] > 400). Of data from 25179 blood samples collected, those from 54 patients satisfied both Formulae 1 and 2. The patients from which these samples were derived from were subject to further analysis: medical records were studied and the intact-parathyroid hormone concentration was measured if necessary. Of these 54 cases, 19 patients (35.2%) were subsequently diagnosed with PHPT, including two, who were newly diagnosed with PHPT by this screening procedure. Although 35 (64.8%) of 54 patients were false-positive, many of them were treated with blood purification therapies in the Department of Pediatrics or the Intensive Care Unit (ICU). On the other hand, there were four false-positive cases (7.4%) caused by MAH. False-negative case in this study was only one patient (5%), whose diagnosis was normocalcemic PHPT. When omitting samples from pediatric patients and those in ICU, this screening procedure for PHPT has the advantage of being able to differentiate this diagnosis from MAH.

Expression of vascular endothelial growth factor by human renal cancer cells enhances angiogenesis of primary tumors and production of ascites but not metastasis to the lungs in nude mice

We determined the role that vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), plays in the progression of human renal cell cancer in nude mice. Low metastatic and low VEGF/VPF-expressing human renal cancer cells SN12C were transfected with the VEGF165 cDNA or plasmid alone as control. VEGF165-transfected SN12C cells produced large amounts of biologically active VEGF in culture that did not affect cell doubling time or confluence. Subsequent to implantation into the renal subcapsule of nude mice, the VEGF165-transfected SN12C cells produced fast-growing (PCNA labeling), large tumors that expressed high levels of VEGF/VPF and were well vascularized (CD3-positive vessels). The tumors produced hyperpermeability of peritoneal blood vessels (Evans blue dye-leak assay), bloody ascites, and short survival time. Parental or control transfected SN12C cells produced less vascularized, slower growing tumors with no ascites. Regardless of in vivo expression level of VEGF, the incidence of spontaneous lung metastasis was low, suggesting that in itself, the expression of VEGF/VPF by renal cancer cells is not sufficient to produce metastasis.

Ligand binding profiles of delta-opioid receptor in human cerebral cortex membranes: evidence of delta-opioid receptor heterogeneity

In this study, receptor binding profiles of opioid ligands for subtypes of opioid delta-receptors were examined employing [3H]D-Pen2,D-Pen5-enkephalin ([3H]DPDPE) and [3H]Ile(5,6)-deltorphin II ([3H]Ile-Delt II) in human cerebral cortex membranes. [3H]DPDPE, a representative ligand for delta1 sites, labeled a single population of binding sites with apparent affinity constant (Kd) of 2.72 +/- 0.21 nM and maximal binding capacity (Bmax) value of 20.78 +/- 3.13 fmol/mg protein. Homologous competition curve of [3H]Ile-Delt II, a representative ligand for delta2 sites, was best fit by the one-site model (Kd = 0.82 +/- 0.07 nM). Bmax value (43.65 +/- 2.41 fmol/mg) for [3H]Ile-Delt II was significantly greater than that for [3H]DPDPE. DPDPE, [D-Ala2,D-Leu5]enkephalin (DADLE) and 7-benzylidenaltrexone (BNTX) were more potent in competing for the binding sites of [3H]DPDPE than for those of [3H]Ile-Delt II. On the other hand, deltorphin II (Delt II), [D-Ser2,Leu5,Thr6]enkephalin (DSLET), naltriben (NTB) and naltrindole (NTI) were found to be equipotent in competing for [3H]DPDPE and [3H]Ile-Delt II binding sites. These results indicate that both subtypes of opioid delta-receptors, delta1 and delta2, exist in human cerebral cortex with different ligand binding profiles.

The hepatitis B virus encoded oncoprotein pX amplifies TGF-beta family signaling through direct interaction with Smad4: potential mechanism of hepatitis B virus-induced liver fibrosis

Hepatitis B, one of the most common infectious diseases in the world, is closely associated with acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Many clinical investigations have revealed that hepatic fibrosis is an important component of these liver diseases caused by chronic hepatitis B. TGF-beta signaling plays an important role in the pathogenesis of fibrosis in chronic hepatitis and cirrhosis. As these diseases are associated with hepatitis B virus (HBV) infection, we examined the possibility that the HBV-encoded pX oncoprotein regulates TGF-beta signaling. We show that pX enhances transcriptional activity in response to TGF-beta, BMP-2, and activin by stabilizing the complex of Smad4 with components of the basic transcriptional machinery. Additionally, confocal microscopic studies suggest that pX facilitates and potentiates the nuclear translocation of Smads, further enhancing TGF-beta signaling. Our studies suggest a new paradigm for amplification of Smad-mediated signaling by an oncoprotein and suggest that enhanced Smad-mediated signaling may contribute to HBV-associated liver fibrosis.

Inhibitory activity of berberine on DNA strand cleavage induced by hydrogen peroxide and cytochrome c

The inhibitory activity of berberine on the DNA single-strand cleavage induced by hydrogen peroxide and cytochrome c was measured. Berberine effectively inhibited single-strand cleavage of DNA and its effectiveness was concentration-dependent. As the berberine concentration increased, the inhibitory activity against the DNA single-strand cleavage increased. The treatments with 1, 5, 10, 50, and 100 microM berberine showed 7.7, 10.8, 32.2, 39.5, and 51.6% inhibition of DNA cleavage. This inhibitory activity of berberine against the DNA single-strand cleavage has never been reported previously. The inhibitory activity of berberine against DNA cleavage was stronger than caffeic acid and ascorbic acid. Berberine did not show strong hydroxyl radical scavenging activity, but showed strong superoxide anion radical quenching ability.

MS-275, a histone deacetylase inhibitor, selectively induces transforming growth factor beta type II receptor expression in human breast cancer cells

Transcriptional repression of the transforming growth factor (TGF)-1P type II receptor (TPRII) gene appears to be a major mechanism to inactivate TGF-beta responsiveness in many human cancers. Because histone acetylation/deacetylation plays a role in transcriptional regulation, we have examined the effect of MS-275, a synthetic inhibitor of histone deacetylase, in human breast cancer cell lines. MS-275 showed antiproliferative activity against all human breast cancer cell lines examined and induced TbetaRII mRNA, but not TGF-beta type I receptor mRNA. MS-275 caused an accumulation of acetylated histones H3 and H4 in total cellular chromatin. An increase in the accumulation of acetylated histones H3 and H4 was detected in the TbetaRII promoter after treatment with MS-275. However, the level of histone acetylation did not change in chromatin associated with the TGF-beta type I receptor gene. MS-275 treatment enhanced TGF-beta1-induced plasminogen activator inhibitor 1 expression. Thus, antitumor activity of MS-275 may be mediated in part through the induction of TbetaRII expression and consequent potentiation of TGF-beta signaling.

Cutaneous myiasis of the breast: mammographic and us features-report of five cases

Five patients with breast myiasis underwent mammography, and three also underwent ultrasonography (US). Mammography revealed indistinct masses in all patients, with associated pairs of microcalcifications in three. US showed each larva as a fusiform hyperechoic mass surrounded by a hypoechoic halo, which included larval movement in one patient. These imaging features of breast myiasis facilitate correct diagnosis.