The presence of multiple NS5A RASs is associated with the outcome of sofosbuvir and ledipasvir therapy in NS5A inhibitor-naïve patients with chronic HCV genotype 1b infection in a real-world cohort

It is unclear whether multiple nonstructural (NS) 5A resistance-associated substitutions (RASs) correlate with the outcome of sofosbuvir (SOF) and ledipasvir (LDV) therapy. We investigated the effects of multiple NS5A RASs in NS5A inhibitor-naïve patients with chronic hepatitis C virus genotype 1b infection treated with SOF/LDV. In 313 patients treated with SOF/LDV, we assessed the effects of multiple NS5A RASs on the sustained virological response (SVR). RASs at L28, R30, L31, Q54, P58, Q62, A92, and Y93 in the NS5A region were examined by direct sequencing. The prevalence of RASs was as follows: 2.6% at L28, 8.7% at R30, 6.1% at L31, 48.7% at Q54, 9.9% at P58, 9.9% at Q62, 5.1% at A92, 13.8% at Y93, and 19.2% at L31 or Y93. A total of 133 patients had no RASs. SVR was achieved in 98.7% of the patients. SVR rates significantly differed between patients with and without the L31 or Y93 RAS (93.0% [53/57] vs 100% [250/250], P = .0011). In addition, among patients with the L31 or Y93 RAS, 29.8%, 45.6% and 24.6% had one, two and three or more NS5A RASs, respectively. The SVR rate was significantly lower in patients with the L31 or Y93 RAS with more than three NS5A RASs compared to those with fewer than three NS5A RASs (71.4% [10/14] vs 100% [43/43], P = .0025). Although the prevalence of multiple NS5A RASs at baseline was low in NS5A inhibitor-naïve patients, the presence of multiple NS5A RASs was associated with the effectiveness of SOF/LDV therapy.

Development of non-invasive method for assessment of hepatic steatosis

Steatosis is a critical feature of liver disease and is considered to play a pivotal role in the progression of nonalcoholic fatty liver disease, as well as being a surrogate marker of metabolic syndrome. The purpose of this study was to develop a non-invasive diagnostic method for assessment of liver steatosis. It is well known that ultrasonic velocity depends on materials and temperature. For example, the ultrasonic velocity in water is 1530m/s at 37°C and 1534m/s at 39°C, while that in fat is 1412m/s at 37°C and 1402m/s at 39°C. On this basis, we thought that the percentage of fat in hepatic steatosis could be assessed by detecting changes of ultrasonic in the liver, caused by warming. In order to confirm the effectiveness of this method, we obtained the ultrasonic velocity changes of tissue phantom including lard oil and the liver of living rabbit by ultrasonic warming, and then succeeded in 2-D imaging of ultrasonic velocity changes of the phantom and the liver of living rabbit. We named this the ultrasonic velocity-change method. The experimental results show the possibility that hepatic steatosis could be characterized using our novel, non-invasive method.

Induction of elastin expression in vascular endothelial cells relates to hepatoportal sclerosis in idiopathic portal hypertension: possible link to serum anti-endothelial cell antibodies

Hepatoportal sclerosis accompanied by dense elastic fibre deposition is generally regarded as the primary lesion in the development of idiopathic portal hypertension (IPH). This study was performed to clarify the mechanism of elastic fibre deposition in the peripheral portal tracts of IPH liver in relation to serum anti-endothelial cell antibodies (AECA). In-vitro experiments were performed using human dermal microvascular endothelial cells (HMVEC) and patients' sera. The presence of serum AECA was assayed by a cell-based enzyme-linked immunosorbent assay (ELISA) using HMVEC. Immunohistochemical analysis of elastin was performed using liver tissue sections of IPH patients. IPH sera contained one or more AECA that could bind to the vascular endothelial cells of the peripheral portal tracts of the liver. When the value of AECA greater than the mean ± 2 standard deviations of healthy controls was regarded as positive, the positive detection rate of either immunoglobulin (Ig)G, IgA or IgM AECA in IPH sera was 30% (10 of 33 cases). IPH sera induced the expression of elastin in HMVEC, which appeared to be associated with the presence of AECA. Apoptosis was also induced in HMVEC by the stimulation with IPH sera. In vivo, elastin expression was observed in the endothelial cells of the peripheral portal tracts of IPH livers in a proportion of cases. The disease pathogenesis of IPH seems to be heterogeneous, and this study elucidated a possible contribution of the induction of elastin expression in the portal vessels to hepatoportal sclerosis of IPH, which might be linked to serum AECA as a causative factor.

Dynamic regulation of midbrain dopamine neuron activity: intrinsic, synaptic, and plasticity mechanisms

Although the roles of dopaminergic signaling in learning and behavior are well established, it is not fully understood how the activity of dopaminergic neurons is dynamically regulated under different conditions in a constantly changing environment. Dopamine neurons must integrate sensory, motor, and cognitive information online to inform the organism to pursue outcomes with the highest reward probability. In this article, we provide an overview of recent advances on the intrinsic, extrinsic (i.e., synaptic), and plasticity mechanisms controlling dopamine neuron activity, mostly focusing on mechanistic studies conducted using ex vivo brain slice preparations. We also hope to highlight some unresolved questions regarding information processing that takes place at dopamine neurons, thereby stimulating further investigations at different levels of analysis.

Activation of inflammatory signaling by lipopolysaccharide produces a prolonged increase of voluntary alcohol intake in mice

Previous studies showed that mice with genetic predisposition for high alcohol consumption as well as human alcoholics show changes in brain expression of genes related to immune signaling. In addition, mutant mice lacking genes related to immune function show decreased alcohol consumption (Blednov et al., 2011), suggesting that immune signaling promotes alcohol consumption. To test the possibility that activation of immune signaling will increase alcohol consumption, we treated mice with lipopolysaccaride (LPS; 1mg/kg, i.p.) and tested alcohol consumption in the continuous two-bottle choice test. To take advantage of the long-lasting activation of brain immune signaling by LPS, we measured drinking beginning one week or one month after LPS treatment and continued the studies for several months. LPS produced persistent increases in alcohol consumption in C57BL/6J (B6) inbred mice, FVBxB6F1 and B6xNZBF1 hybrid mice, but not in FVB inbred mice. To determine if this effect of LPS is mediated through binding to TLR4, we tested mice lacking CD14, a key component of TLR4 signaling. These null mutants showed no increase of alcohol intake after treatment with LPS. LPS treatment decreased ethanol-conditioned taste aversion but did not alter ethanol-conditioned place preference (B6xNZBF1 mice). Electrophysiological studies of dopamine neurons in the ventral tegmental area showed that pretreatment of mice with LPS decreased the neuronal firing rate. These results suggest that activation of immune signaling promotes alcohol consumption and alters certain aspects of alcohol reward/aversion.

The pharmacokinetic profile of crocetin in healthy adult human volunteers after a single oral administration

Crocetin, a unique carotenoid with a short carbon chain length, is an active compound of saffron and Gardenia jasminoides Ellis used as traditional herbal medicine. The present study was undertaken to investigate the pharmacokinetic profiles of crocetin in healthy adult subjects. The study was conducted as an open-label, single dose escalation with 10 Filipino volunteers (5 men and 5 women). The subjects received a single dose of crocetin at three doses (7.5, 15 and 22.5 mg) in one week interval. Blood samples were collected from the brachial vein before and at 1, 2, 4, 6, 8, 10 and 24 h after administration. Plasma concentrations of crocetin were determined by high-performance liquid chromatography (HPLC). Crocetin was rapidly absorbed and detected within an hour of administration with a mean time to reach maximum concentration (T(max)) of crocetin ranging from 4.0 to 4.8 h. The mean values of C(max) and AUC(0-24h) ranged from 100.9 to 279.7 ng/ml and 556.5 to 1720.8 ng. h/ml respectively. C(max) and AUC values increased with dose proportional manner. Crocetin was eliminated from human plasma with a mean elimination half life (T(½) of 6.1 to 7.5 h. In summary, there were no serious adverse events up to 22.5 mg dose of crocetin while crocetin was found to be absorbed more quickly than the other carotenoids such as β-carotene, lutein and lycopene.

GABAergic transmission modulates ethanol excitation of ventral tegmental area dopamine neurons

Activation of the dopaminergic (DA) neurons of the ventral tegmental area (VTA) by ethanol has been implicated in its rewarding and reinforcing effects. We previously demonstrated that ethanol enhances GABA release onto VTA-DA neurons via activation of 5-HT2C receptors and subsequent release of calcium from intracellular stores. Here we demonstrate that excitation of VTA-DA neurons by ethanol is limited by an ethanol-enhancement in GABA release. In this study, we performed whole-cell voltage clamp recordings of miniature inhibitory postsynaptic currents (mIPSCs) and cell-attached recordings of action potential firing from VTA-DA neurons in midbrain slices from young Long Evans rats. Acute exposure to ethanol (75 mM) transiently enhanced the firing rate of VTA-DA neurons as well as the frequency of mIPSCs. Simultaneous blockade of both GABA(A) and GABA(B) receptors (Picrotoxin (75 μM) and SCH50911 (20 μM)) disinhibited VTA-DA firing rate whereas a GABA(A) agonist (muscimol, 1 μM) strongly inhibited firing rate. In the presence of picrotoxin, ethanol enhanced VTA-DA firing rate more than in the absence of picrotoxin. Additionally, a sub-maximal concentration of muscimol together with ethanol inhibited VTA-DA firing rate more than muscimol alone. DAMGO (3 μM) inhibited mIPSC frequency but did not block the ethanol-enhancement in mIPSC frequency. DAMGO (1 and 3 μM) had no effect on VTA-DA firing rate. Naltrexone (60 μM) had no effect on basal or ethanol-enhancement of mIPSC frequency. Additionally, naltrexone (20 and 60 μM) did not block the ethanol-enhancement in VTA-DA firing rate. Overall, the present results indicate that the ethanol enhancement in GABA release onto VTA-DA neurons limits the stimulatory effect of ethanol on VTA-DA neuron activity and may have implications for the rewarding properties of ethanol.

Add-on combination therapy with adefovir dipivoxil induces renal impairment in patients with lamivudine-refractory hepatitis B virus

Combination therapy with adefovir dipivoxil (ADV) and lamivudine (LAM) is recommended for patients infected with LAM-refractory hepatitis B virus (HBV). However, the effects of such therapy on renal function and serum phosphorus levels have not been fully evaluated. Combination therapy with ADV and LAM was given to 37 patients infected with LAM-refractory HBV, including 17 with hepatic cirrhosis. Serum HBV DNA levels decreased to below 2.6 log(10) copies/mL in 23 (62%) of 37 patients at 12 months, 25 (78%) of 32 patients at 24 months, and 16 (84%) of 19 patients at 36 months. Except for one cirrhotic patient, serum alanine aminotransferase levels were below 50 IU/L in all patients during combination therapy. Serum creatinine levels increased in 14 (38%) of 37 patients, and serum phosphate levels decreased to below 2.5 mg/mL in 6 (16%) of 37 patients during combination therapy. Patients who received combination therapy for 36 months or longer had a significantly incidence of elevated serum creatinine levels. Fanconi syndrome occurred in a 57-year-old woman with cirrhosis after ADV was added to LAM. Combination therapy with ADV and LAM can maintain biochemical remission in patients with LAM-refractory HBV. However, the dosing interval of ADV should be adjusted according to renal function and serum phosphate levels in patients receiving long-term treatment.

Use of real‐time magnetic resonance image guidance in endoscopic sinus surgery

We evaluated the effectiveness of magnetic resonance image (MRI) guidance using an optical tracking system (MRI-guided therapy: MRT) in performing endoscopic sinus surgery (ESS). The profiles of the fourteen patients in the present study were as follows: eleven with mucocele in the paranasal sinus, one with recurrent chronic sinusitis, one with maxillary cancer, and one with Graves' ophthalmopathy. Preparation of the MRT system required an additional 54 min in cases involving general anesthesia, and an additional 17 min in cases involving local anesthesia, in comparison with corresponding control groups undergoing ESS in a traditional operating room. We developed nonmetal probes that were visualized in a real-time mode and assistive devices for the optical tracking system that were equipped to avoid obstruction caused by surgical instruments as well as by the hands of surgeons. Using these unique devices, anatomic landmarks were visualized using the present MRT system. The prognosis of patients was favorable, and in particular, no patients with sinus mucocele showed a recurrence of their lesions. We concluded that the MRT system used here for performing ESS was beneficial, especially in terms of the intranasal marsupialization of sinus mucoceles and for the verification of orbital contents.

Favorable Acute and Long-Term Outcomes after the Resection of Pulmonary Aspergillomas

OBJECTIVE

This retrospective study was designed to examine the acute and long-term outcomes after surgical treatment of patients with pulmonary aspergillomas.

PATIENTS AND METHODS

From 1992 to 2006, 24 patients (21 men, mean age 58.4 years) with pulmonary aspergillomas underwent pulmonary resection. Operative indications were massive or repetitive hemoptysis in 6 patients, medically unmanageable localized infection in 14 patients, and undetermined mass in 4 patients. Eighteen patients (75.0 %) had background pulmonary diseases and four patients (16.7 %) were mildly immunocompromised. Eight patients had simple aspergillomas, while sixteen patients had complex aspergillomas. Two patients with pleural empyema had their pleural spaces sterilized before pulmonary resections. Fungus balls and pulmonary cavities along with the surrounding lung were removed in all patients.

RESULTS

Surgical procedures consisted of 13 lobectomies, 5 pneumonectomies including one completion pneumonectomy, 2 segmentectomies and 4 wedge resections. Postoperative complication occurred in 10 patients (41.6 %) and one patient died from aortic bleeding due to postoperative empyema. Other major complications were prolonged air leaks, bleeding, and chylothorax. In the follow-up period, all but one patient were free from aspergillosis. Hemoptysis was not seen in any patient. Overall survival rates at 2, 5, and 10 years were 86.6 %, 79.4 % and 79.4 %, respectively. Disease-free survival rates from aspergillosis were 86.6 %, 72.6 % and 72.6 % at 2, 5, and 10 years, respectively.

CONCLUSION

Pulmonary resection for aspergilloma showed favorable acute and long-term outcomes when surgical treatment was applied in selected patients.

Characterization of salt tolerance in ectoine-transformed tobacco plants (Nicotiana tabaccum): photosynthesis, osmotic adjustment, and nitrogen partitioning

Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) biosynthetic genes (ect. ABC) from Halomonas elongata were introduced to tobacco plants using an Agrobacterium-mediated gene delivery system. The genes for ectoine biosynthesis were integrated in a stable manner into the tobacco genome and the corresponding transcripts were expressed. The concentration of ectoine under salt-stress conditions was higher in the roots than in leaves. A close relationship was found between stomatal conductance and the amount of transported nitrogen, suggesting that water transport through the xylem in the stem and transpiration may be involved in nitrogen transport to leaves. The data indicate that the turgor values of the ectoine transgenic lines increased with increasing salt concentration. The data revealed two ways in which ectoine enhanced salinity tolerance of tobacco plants. First, ectoine improved the maintenance of root function so that water is taken up consistently and supplied to shoots under saline conditions. Second, ectoine enhanced the nitrogen supply to leaves by increasing transpiration and by protecting Rubisco proteins from deleterious effects of salt, thereby improving the rate of photosynthesis.

Overexpression of a DEAD box/RNA helicase protein, rck/p54, in human hepatocytes from patients with hepatitis C virus-related chronic hepatitis and its implication in hepatocellular carcinogenesis

Hepatitis C virus (HCV) infection is the most common cause of chronic hepatitis, which frequently progresses to hepatocellular carcinoma. The pathogenesis of its persistent infection and tumour progression has not been fully characterized yet. The RCK gene was previously cloned at the breakpoint of the t(11;14)(q23;q32) chromosome translocation observed in human B-cell lymphoma cell line RC-K8. The RCK protein, rck/p54, which is a 54-kDa cytoplasmic protein belonging to the DEAD box/RNA helicase family, is considered to facilitate the translation of mRNA(s) of genes for cell proliferation and malignant transformation not only in B-cell lymphomas having the t(11;14) translocation but also in other solid tumours. The aim of this work was to examine the involvement of rck/p54 in carcinogenesis of hepatocellular carcinoma from HCV-related chronic hepatitis. We examined the expression of rck/p54 in 29 cases of HCV-related chronic hepatitis and eight cases of hepatocellular carcinoma by immunohistochemistry and Western blot analysis. Twenty-six of 29 cases with HCV-related chronic hepatitis and all cases with hepatocellular carcinoma tested overexpressed rck/p54 protein. The expression of rck/p54 was lowered by treatment with IFN-alpha in two cases who showed the decrease in HCV RNA levels. These findings suggest that rck/p54 protein is possibly involved in the replication of HCV genomes in hepatocytes and in tumourigenesis of hepatocellular carcinomas.

A case of dermatomyositis complicated with pneumomediastinum successfully treated with cyclosporin A

We describe a rare case of a 46-year-old Japanese man with dermatomyositis (DM) and interstitial lung disease who developed spontaneous pneumomediastinum and subcutaneous emphysema. Relatively mild myositis, mild elevation of CK values and the absence of anti-Jo-1 antibody were observed and the case was similar to amyopathic DM. Treatment of this patient with oral prednisolone and cyclosporin A (CsA) was effective for the myositis and interstitial lung disease. The administration of CsA enabled rapid tapering of the dose of prednisolone without aggravating the disease. Pneumomediastinum and subcutaneous emphysema disappeared 5 months later without recurrence. The serum levels of KL-6 were monitored every 2 weeks to help determine whether this may have contributed to the recurrence of interstitial pneumonitis. This is a rare case of pneumomediastinum in a patient with DM.

Co-overexpression of DEAD box protein rck/p54 and c-myc protein in human colorectal adenomas and the relevance of their expression in cultured cell lines

The RCK gene was cloned through a study of the breakpoint of the t(11;14)(q23;q32) chromosomal translocation observed in a human B-cell lymphoma and overexpression of the protein (rck/p54) due to the translocation was shown to be associated with malignant transformation. The rck/p54 protein belongs to the DEAD box protein/RNA helicase family, which has a variety of functions such as translation initiation, pre-mRNA splicing and ribosome assembly. It is considered that rck/p54 protein may have significant effects on the mRNA structure of genes associated with cell proliferation, facilitating protein synthesis. Expression of rck/p54 in colorectal adenomas, which are a premalignant lesion of colorectal cancer, was examined by Western blot analysis and immunohistochemistry. The rck/p54 protein was found to be overexpressed in tumor tissues resected from 17 of 26 cases (65.4%) of colorectal adenomas and 13 of 14 c-myc-positive cases (92.8%) also co-overexpressed rck/p54 protein. Thus, a significant correlation between rck/p54 and c-myc co-overexpression was found (Spearman's rank correlation, P = 0.0018). We demonstrate that overexpression of rck/p54 in two different cell lines, COS 7 and human colorectal cancer cell line SW480, caused an increase in c-myc protein levels by enhancement of its translation efficiency and/or stabilization of its mRNA. These results suggest that rck/p54 of the DEAD box protein/RNA helicase family may contribute to cell proliferation and carcinogenesis in the development of human colorectal tumors at the translational level by increasing synthesis of c-myc protein.

Activation of mu-opioid receptor induces expression of c-fos and junB via mitogen-activated protein kinase cascade

BACKGROUND

Opioid-induced long-term functional alterations of the nervous system, such as tolerance, addiction, and dependence, conceivably involve changes in gene expression. The authors have previously reported that opioid receptors are functionally coupled to extracellular signal-regulated kinase, a class of the mitogen-activated protein kinase. To address whether activation of the opioid receptor induces changes in gene expression through the activation of extracellular signal-regulated kinase, the authors examined mu-opioid receptor (MOR)-induced immediate early gene expression.

METHODS

Chinese hamster ovary cells stably expressing MOR were used. Cells were stimulated by MOR agonists after 24-h serum starvation. Expression of c-fos and junB genes was analyzed by RNA blot hybridization. To explore the mechanism of MOR-mediated c-fos and junB expression, activity of a transcription factor, Elk-1, was assessed by reporter assay. Furthermore, to investigate the functional consequences of c-fos and junB induction, MOR-mediated formation of the functional transcription factor complex AP-1 was examined by reporter assay and electrophoretic mobility shift assay.

RESULTS

Mu-opioid receptor activation induced c-fos and junB messenger RNAs, which were inhibited by pretreatment of the cells with pertussis toxin and PD98059, an inhibitor of extracellular signal-regulated kinase cascade. MOR stimulation elevated Elk-1-mediated transcriptional activity by about 10-fold. AP-1-mediated transcriptional activity was stimulated by MOR agonists by about twofold. Electrophoretic mobility shift assay revealed that AP-1 binding activity in the nuclear extract was elevated by MOR activation and further showed that products of c-fos and junB genes are involved in formation of AP-1 complex.

CONCLUSIONS

Mu-opioid receptor activation induces c-fos and junB expression and elevates AP-1-mediated transcriptional activities via the mitogen-activated protein kinase cascade.

Intestinal motility in an in vivo rat model of intestinal ischemia-reperfusion with special reference to the effects of nitric oxide on the motility changes

BACKGROUND

To clarify the relation between intestinal ischemia-reperfusion (IR) and dysmotility, the authors investigated changes in the motility pattern in the duodenum and jejunum in an in vivo rat model of IR when artery- (and vein-) fed jejunum was clamped transiently. The authors also studied the effect of nitric oxide on the motility changes in this model by means of the administration of L-NAME (N(G)-nitro-L-arginine methyl ester) or S-methylisothiourea sulfate (SMT).

MATERIALS AND METHODS

A force transducer was sutured onto the serosal side of the duodenum or jejunum. After a 3-to 4-day recovery period, contractions were recorded during periods of preischemia, ischemia (60 minutes), and reperfusion (90 minutes). An intestinal IR was produced by clamping and releasing the mesenteric artery and vein with artery forceps.

RESULTS

In the jejunum, there was a prolongation in the duration of contraction and there were decreases in the number of contractions (NC) during the IR. When treated with L-NAME, no decrease in the NC was observed during the 45 to 90 minutes after reperfusion. S-methylisothiourea sulfate did not affect the IR-induced motility changes significantly. In the duodenum, there was a prolongation in the duration of contraction and a decrease in the NC and AC only during the reperfusion. L-NAME or S-methylisothiourea sulfate inhibited the decreases in the NC during the reperfusion.

CONCLUSIONS

Intestinal IR causes motility changes in the ischemic site during the IR and in the nonischemic site during the reperfusion. The IR-induced motility changes partly depend on nitric oxide production.

Loss of heterozygosity of nucleotide excision repair factors in sporadic oral squamous cell carcinoma using microdissected tissue

The deficiencies of nucleotide excision repair (NER) factors are involved in rare genetic diseases such as xeroderma pigmentosum (XP) with increased risk of developing cancer on sun-exposed areas of the skin. However, the abnormality of NER factors in human sporadic carcinoma remains unclear. Loss of heterozygosity (LOH) analysis, using the microdissected tissues, for the XPA, XPB, XPC, XPD, XPE, XPF, XPG and the transcription-coupled repair factor, Cockayne syndrome B (CSB) revealed that NER factors were abnormal in 30.0% (3/10 cases) of oral squamous cell carcinomas. Furthermore, 10.0% of oral carcinomas exhibited LOH for NER factors without LOH for tumor suppressor genes such as p53, FHIT, APC, BRCA1, BRCA2 and DCC. These observations raise the possibility that alterations of NER factors may be involved in carcinogenesis in human oral squamous cell carcinoma.

Cutaneous mastocytosis associated with a mixed germ cell tumour of the ovary: report of a case and review of the literature

A 10-year-old girl with a mixed germ cell tumour of the ovary, treated by surgery and chemotherapy, developed cutaneous mastocytosis approximately 8 months after starting chemotherapy. This is the sixth report of a germ cell tumour associated with mastocytosis. c-kit receptor point mutations, including Asp816Val and Val560Gly were absent in a biopsy specimen obtained from lesional skin.

[A case of Bellini duct carcinoma producing granulocyte colony-stimulating factor (G-CSF)]

A case of Bellini duct carcinoma producing granulocyte colony-stimulating factor (G-CSF) is reported. The patient was a 75-year-old female with the chief complaint of appetite loss. Abdominal ultrasonography and abdominal computed tomography revealed left renal pelvic tumor. Left radical nephrouretrectomy was performed. The histopathological report showed Bellini duct carcinoma. Immunohistochemical staining using the anti-G-CSF antibody showed positive staining in the cancer cells. Preoperatively, the white blood cell count and serum G-CSF concentration were elevated to 34,100/microliter and 334 pg/ml respectively. After operation these values became normal. However, these values were elevated again and CT scan revealed a left pulmonary metastasis 3 months after the operation. In spite of chemotherapy, she died of brain metastases 7 months after the operation.

Simultaneous separation of common mono- and divalent cations on a zirconium-modified silica gel column by ion chromatography with non-suppressed conductimetric detection and tartaric acid-15-crown-5 as eluent

The application of laboratory-made zirconium-modified silica gels (Zr-silicas) as cation-exchange stationary phases to ion chromatography with conductimetric detection (IC-CD) for common mono- and divalent cations (Li+, Na+, NH4+, K+, Mg2+ and Ca2+) was carried out. Zr-silicas were prepared by the reaction of the silanol group on the surface of silica gel with zirconium tetrabutoxide (Zr(OCH2CH2CH2CH3)4) in ethanol. Zr-silica adsorbed on 10 mg zirconium g(-1) silica gel was a suitable cation-exchange stationary phase in IC-CD for the separation of these mono- and divalent cations. Excellent simultaneous separation and highly sensitive detection for these cations were achieved in 10 min by IC-CD using a Zr-silica column (150x4.6 mm I.D.) and 10 mM tartaric acid containing 10 mM 15-crown-5 (1,4,7,10,13-pentaoxacyclopentadecane) as the eluent. The proposed IC-CD method was successfully applied to the determination of major mono- and divalent cations in natural water samples.

Nitrite reductase gene enrichment improves assimilation of NO(2) in Arabidopsis

Transgenic plants of Arabidopsis bearing the spinach (Spinacia oleracea) nitrite reductase (NiR, EC 1.7.7.1) gene that catalyzes the six-electron reduction of nitrite to ammonium in the second step of the nitrate assimilation pathway were produced by use of the cauliflower mosaic virus 35S promoter and nopaline synthase terminator. Integration of the gene was confirmed by a genomic polymerase chain reaction (PCR) and Southern-blot analysis; its expression by a reverse transcriptase-PCR and two-dimensional polyacrylamide gel electrophoresis western-blot analysis; total (spinach + Arabidopsis) NiR mRNA content by a competitive reverse transcriptase-PCR; localization of NiR activity (NiRA) in the chloroplast by fractionation analysis; and NO(2) assimilation by analysis of the reduced nitrogen derived from NO(2) (NO(2)-RN). Twelve independent transgenic plant lines were characterized in depth. Three positive correlations were found for NiR gene expression; between the total NiR mRNA and total NiR protein contents (r = 0.74), between the total NiR protein and NiRA (r = 0.71), and between NiRA and NO(2)-RN (r = 0.65). Of these twelve lines, four had significantly higher NiRA than the wild-type control (P < 0.01), and three had significantly higher NO(2)-RN (P < 0.01). Each of the latter three had one to two copies of spinach NiR cDNA per haploid genome. The NiR flux control coefficient for NO(2) assimilation was estimated to be about 0.4. A similar value was obtained for an NiR antisense tobacco (Nicotiana tabacum cv Xanthi XHFD8). The flux control coefficients of nitrate reductase and glutamine synthetase were much smaller than this value. Together, these findings indicate that NiR is a controlling enzyme in NO(2) assimilation by plants.

Presence of an SAR-like sequence in junction regions between an introduced transgene and genomic DNA of cultured tobacco cells: its effect on transformation frequency

A 12.5-kb DNA fragment with junction regions between the transgene and genomic DNA was cloned from a transgenic tobacco cell line obtained by microprojectile bombardment of plasmid pCaMVNEO. Nucleotide sequence analysis of the fragment (DDBJ accession no. D84238) showed that it carried a 7.7-kb core sequence (concatemer of a complete pCaMVNEO and a partial pCaMVNEO) and two identical 1.3-kb junction sequences that flanked both the 5' and 3' ends of the core sequence and had inverted orientations. These sequences had topoisomerase II (Topo II) cleavage sites and adenine and thimine-rich sequences known to be specific to nuclear scaffold-attachment regions (SARs). An in vitro binding assay showed that a 507-bp fragment (designated TJ1) from the 1.3-kb sequence had the ability to bind to nuclear scaffold preparations of cultured tobacco cells, confirmation that the 1.3-kb sequence is an SAR. Insertion of TJ1 at the 5' and 3' sides of the expression cassette for the npt II gene increased transformant yields 5- to 10-fold and the NPT II enzyme activity per copy of the gene 5-fold. TJ1 enhances the integration or expression of the transgene, or both. Clearly, TJ1 is very useful for producing transgenic plants. This is the first report on an SAR-like sequence that is located in the transgene locus and enhances transformation efficiency in eukaryotic cells. The possible role of TJ1-SAR in the molecular evolution of plant genome is discussed.

Increases of calcium and magnesium and decreases of phosphorus and iron with aging in human uterine tubes

To elucidate compositional changes of the uterine tube by aging, the authors studied age-related changes of elements in human uterine tubes by inductively coupled plasma-atomic emission spectrometry. The uterine tubes were resected postmortem or surgically removed from patients with uterine myoma. It was found that the contents of calcium and magnesium increased progressively with aging in uterine tubes, whereas the contents of phosphorus and iron decreased gradually with aging. The sulfur content of uterine tubes remained constant and independent of aging. Regarding relationships between elements, significant relationships were found between calcium and magnesium contents, between phosphorus and iron contents, between phosphorus and sulfur contents, and between phosphorus and sodium contents in human uterine tubes.

Amphetamine selectively blocks inhibitory glutamate transmission in dopamine neurons

Amphetamine is a highly addictive psychostimulant that promotes the release of the catecholamines dopamine and norepinephrine. Amphetamine-induced release of dopamine in the midbrain inhibits the activity of dopamine neurons through activation of D2 dopamine autoreceptors. Here we show that amphetamine may also excite dopamine neurons through modulation of glutamate neurotransmission. Amphetamine potently inhibits metabotropic glutamate receptor (mGluR)-mediated IPSPs in dopamine neurons, but has no effect on ionotropic glutamate receptor-mediated EPSCs. Amphetamine desensitizes the mGluR-mediated hyperpolarization through release of dopamine, activation of postsynaptic alpha1 adrenergic receptors, and suppression of InsP3-induced calcium release from internal stores. By selectively suppressing the inhibitory component of glutamate-mediated transmission, amphetamine may promote burst firing of dopamine neurons. Through this mechanism, amphetamine may enhance phasic release of dopamine, which is important in the neural processing of reward.

[Costimulatory molecule expression on allergen-stimulated PBMC in cedar pollinosis subjects]

B7-1 (CD80) and B7-2 (CD86) play important roles in the differentiation of Th1 and Th2 phenotypes. CD40-CD40L interaction supports the expression of CD80 and CD86 on antigen-presenting cells. Blocking studies suggest these molecules also play important roles in sensitization to a cedar pollen antigen by, but very few studies have concerned their effects on subsequent induction by antigens. We investigated the roles of CD80, CD86, and CD40 in the differentiation of Th1 and Th2 subsets after stimulation with the antigen in subjects with cedar pollinosis. Peripheral blood mononuclear cells (PBMC) were isolated from 12 subjects with pollinosis and 11 healthy controls and stimulated with cedar pollen extract. After in vitro stimulation, CD80, CD86, and CD40 expression on CD19+ cells were analyzed by flow cytometry. The production of type 1 and type 2 cytokines in culture supernatants was measured by FLISA. Proliferation studies were conducted in the presence or absence of anti-CD40 or CD86 mAbs. After in vitro stimulation, CD86 and CD40 were significantly up-regulated following stimulation in pollinosis subjects (p = 0.02 and p = 0.04). A significantly higher level of IL-5 (p = 0.02) was produced by PBMC of pollinosis subjects than by those of controls. Allergen-induced proliferation and IL-5 production of PBMC of pollinosis subjects were inhibited by anti-CD86 mAb but not CD40 mAb. These results indicate that the Th2 response predominated in pollinosis subjects and that CD86 rather than CD80 may be the costimulatory molecule involved in the allergen-induced activation of PBMC.

[Antioxidative effects of fluvastatin, and its major metabolites [II]]

We investigated the antioxidative effects of fluvastatin (FV or (+/-)-FV), each enantiomer ((+)-FV, (-)-FV) and its major metabolites on lipid peroxidation using rat and human liver microsomes. The extent of NADPH induced microsomal (Ms) lipid peroxidation was determined by thiobarbituric acid (TBA) assay. The antioxidative effect of each compound was shown as the percentage of inhibition on the formation of TBA reactive substance (TBARS) against vehicle control. The antioxidative effects of alpha-tocopherol (Toc), a potent antioxidative vitamin, probucol (PR), a potent antioxidative drug, pravastatin (PV) and simvastatin (SV), HMG-CoA reductase inhibitors, were also tested. The (+/-)-FV inhibit the formation of TBARS by 40 to 70% depending on Ms concentrations. The antioxidative effects of PR and TOC were comparable to those of FV. The inhibitory effects of PV and SV on the formation of TBARS were less potent than (+/-)-FV, PR and TOC. (+)-FV, (-)-FV, and (+/-)-FV inhibited the formation of TBARS by approximately 50% using rat hepatic microsomes. The antioxidative effects of (+)-FV was comparable to that of (-)-FV using human hepatic microsomes. These results indicated that the antioxidative effects of (+)-FV were comparable to those of (-)-FV, although the HMG-CoA reductase inhibitory activity of (+)-FV was 30-fold higher than that of (-)-FV.

Altered expression of heme oxygenase-1 in the livers of patients with portal hypertensive diseases

This study was designed to determine changes in expression of heme oxygenase (HO)-1, the stress-inducible and carbon monoxide-producing enzyme, in normotensive and portal hypertensive human livers. GTS-1, a monoclonal antibody against rat HO-1 cross-reacted with the human HO-1 and blocked its enzyme activity, allowing us to examine the activity and localization of HO-1. In controls, approximately 50% of the total HO activity was from HO-1 as judged by the sensitivity to GTS-1, while the rest of activity was from other isozymes such as HO-2. HO-1 was expressed mainly in a subpopulation of Kupffer cells, and the expression in hepatic stellate cells, sinusoidal endothelial cells, and hepatocytes was little, if any. The HO-1 expression exhibited quite different pictures in the livers of portal hypertensive diseases. In cirrhotic livers, which undergo portal hypertension through increases in intrasinusoidal resistance and regenerative changes in the parenchyma, HO-1 occurred in a majority of Kupffer cells and was also observed in hepatocytes. Consequently, the total HO-1 activities became significantly greater in these tissues than those from normal individuals. By contrast, livers of idiopathic portal hypertension that are characterized by an increase in presinusoidal resistance displayed a significant decrease in the HO-1 expression in Kupffer cells, and its hepatocellular expression was not detectable. Although factors involved in altered HO-1 expression in these cells remain unknown, the results suggest that Kupffer cells could alter their expression of HO-1 in response to local hemodynamic changes associated with chronic portal hypertension in humans.

Surface hardness changes induced by O-, Ca- or P-ion implantation into titanium

Titanium or titanium alloys are very attractive biomedical materials. Biocompatible elements of oxygen, calcium and phosphorus were implanted into titanium and changes of surface hardness were measured using an ultra micro indenter (UMIS-2000). A multiple load-partial unload procedure that can reveal a hardness versus depth profile was adopted. Depth profiles of concentration of implanted ions were obtained by SIMS measurement. For O and P implantation, it is observed that the hardness increases with the increases in the dose. O implantation produced the largest increase in hardness, up to 2.2 times higher than the unimplanted titanium. On the other hand, Ca implantation produced only a small increase in the hardness that was independent of the ion dose. The surface oxide layer of a Ca implanted titanium sample was much thicker than the unimplanted samples or those implanted with O and P ions. The depth of maximum hardness increases with increasing energy of implanted ions. The depths of the maximum hardness occur at indentation depths of one-third to one-eighth of the mean ranges of implanted ions.

Regulation of central synaptic transmission by 5-HT(1B) auto- and heteroreceptors

Although 5-HT(1B) receptors are believed to be expressed on nerve terminals, their precise mode of action is not fully understood because of the lack of selective antagonists. The 5-HT(1B) receptor knockout mouse was used in the present investigation to assess the function of 5-HT(1B) receptors in the modulation of synaptic transmission in three areas of the central nervous system: the dorsal raphe, the ventral midbrain, and the nucleus accumbens. N-(3-Trifluoromethylphenyl)piperazine, a 5-HT(1B) receptor agonist, potently inhibited 5-HT(1A) receptor-mediated slow inhibitory postsynaptic potentials (IPSPs) in the dorsal raphe of wild-type but not knockout mice. Both synaptically released 5-HT and exogenous 5-HT caused a presynaptic inhibition that outlasted the postsynaptic hyperpolarization only in wild-type mice. In the ventral midbrain, 5-HT(1B) receptor-dependent inhibition of gamma-aminobutyric acid(B) IPSPs in dopamine neurons was present in wild-type animals and absent in knockout animals. Similar results were obtained in the nucleus accumbens measuring glutamate-mediated excitatory postsynaptic currents in medium spiny neurons. Finally, cocaine, which blocks 5-HT uptake, inhibited IPSPs in the dorsal raphe and the ventral midbrain of wild-type but not knockout mice, whereas cocaine produced comparable inhibition of excitatory postsynaptic currents in the nucleus accumbens of both types of animals. These results indicate that 5-HT(1B) receptors function as autoreceptors and heteroreceptors to exert presynaptic inhibition of transmitter release in the central nervous system. Furthermore, this study underscores the role played by presynaptic 5-HT(1B) receptors in mediating the effects of cocaine on synaptic transmission.

Frequent altered expression of fragile histidine triad protein in human colorectal adenomas

Fragile histidine triad (FHIT) gene is involved in deletions on the short arm of chromosome 3 in various human cancers. We found that 47% of colorectal adenomas, which is a higher frequency than that of K-ras, showed altered expression of the Fhit protein by Western blot analysis. The amount of Fhit protein was inversely correlated with the degree of dysplasia. Importantly, 27% of low-grade dysplastic adenomas showed altered expression of Fhit protein. Additionally, expression of human Fhit protein in human colon carcinoma cell line SW480 exhibited a marked inhibition of growth and rendered SW480 cells highly susceptible to undergo apoptosis compared with control cells. These findings suggest that altered expression of the FHIT gene is a quite early aberration in the development of colorectal tumors and that Fhit protein may act as a tumor suppressor.