Effects of reactive oxygen species on proliferation of Chinese hamster lung fibroblast (V79) cells

Reactive oxygen species (ROS) have emerged as important signaling molecules in the regulation of various cellular processes. In our study, we investigated the effect of a wide range of ROS on Chinese hamster lung fibroblast (V79) cell proliferation. Treatment with H2O2 (100 microM), superoxide anion (generated by 1 mM xanthine and 1 mU/ml xanthine oxidase), menadione, and phenazine methosulfate increased the cell proliferation by approximately 50%. Moreover, a similar result was observed after partial inhibition of superoxide dismutase (SOD) and glutathione peroxidase. This upregulation of cell proliferation was suppressed by pretreatment with hydroxyl radical scavengers and iron chelating agents. In addition to ROS, treatment with exogenous catalase and SOD mimic (MnTMPyP) suppressed the normal cell proliferation. Short-term exposure of the cells to 100 microM H2O2 was sufficient to induce proliferation, which indicated that activation of the signaling pathway is important as an early event. Accordingly, we assessed the ability of H2O2 to activate mitogen-activated protein kinases (MAPK). Jun-N-terminal kinase (JNK) and p38 MAPK were both rapidly and transiently activated by 100 microM H2O2, with maximal activation 30 min after treatment. However, the activity of extracellular signal-regulated kinase (ERK) was not changed. Pretreatment with SB203580 and SB202190, specific inhibitors of p38 MAPK, reduced the cell proliferation induced by H2O2. The activation of both JNK and p38 MAPK was also suppressed by pretreatment with hydroxyl radical scavenger and iron chelating agents. Our results suggest that the trace metal-driven Fenton reaction is a central mechanism that underlies cell proliferation and MAPK activation.

Signaling pathways in the induction of c-met receptor expression by its ligand scatter factor/hepatocyte growth factor in human glioblastoma

Scatter factor/hepatocyte growth factor (SF/HGF) and its tyrosine kinase receptor c-met are developmentally expressed, neuroprotective, and tumorigenic within the CNS. In the present study SF/HGF is shown to induce the expression of c-met in two human glioblastoma cell lines, U-373 MG and T98G, and the signaling pathways involved in this induction are dissected. SF/HGF activated mitogen-activated protein kinase (MAPK) and inhibition of either Ras or MAPK-kinase completely inhibited SF/HGF-mediated c-met induction. Inhibition of phospholipase-C (PLC) did not affect c-met induction in either cell line. Inhibition of phosphoinositide 3-kinase (PI3-kinase) substantially reduced c-met induction by SF/HGF in T98G cells but had no effect in U-373 MG cells. Protein kinase C (PKC) inhibition reduced c-met induction in T98G cells but not in U-373 MG cells. SF/HGF induced the expression of c-fos and c-jun mRNA and increased the levels of AP-1 transcription factor in both cells lines as determined by AP-1-luciferase reporter expression. Transfection of either cell line with TAM-67, a dominant negative for the jun transactivation domain, completely inhibited AP-1 and c-met induction by SF/HGF. These results support a model of c-met induction by SF/HGF in human glioma cells that uniformly involves Ras, MAPK, and AP-1 and additionally involves PI3-kinase and PKC in some cell lines.

Lymphoscintigraphy using (99m)Tc filtered sulfur colloid in chylothorax: a case report

OBJECTIVE

A 66-y-old man was diagnosed with esophageal carcinoma and underwent a right thoracotomy and esophagectomy. Postoperatively, a recurring right pleural effusion developed. Because an attempt at lymphangiography failed, lymphoscintigraphy was suggested. Because of the inability to obtain radiolabeled albumin, dextran, or nanocolloid, we used filtered sulfur colloid. (0.1 um). The study confirmed the diagnosis of chylothorax.

Contamination of a bracelet following iodine-131 therapy: a case report

A 73-y-old patient who had thyroid carcinoma had a post-treatment, whole-body 131I scan. The scan demonstrated an artifact caused by a bracelet contaminated with radioactive perspiration. This finding resulted in an artifact on the scan and had potential radiation safety implications.

Multicentric biatrial myxoma in a young female patient: case report

We report a case of multicentric, biatrial cardiac myxoma in a 29-year-old female who complained of exertional dyspnea, abdominal distension and peripheral edema. Any other associated skin lesions, breast mass or endocrine disorder presenting complex form were' not seen on her. Also, there was no contributory medical history, hypertension and diabetes mellitus. By using transthoracic echocardiography, we identified a biatrial myxoma attached to the interatrial septum. During surgical excision, we found a large right atrial myxoma with extension through the fossa ovalis into the left atrium and small myxoma attached to the right atrial free wall. After successful resection of interatrial septum and free wall, atrial septal defect was created during the resection and safely repaired by bovine pericardial patch.

Mutagenesis of the glucoamylase signal peptide of Saccharomyces diastaticus and functional analysis in Saccharomyces cerevisiae

To improve the efficiency of the glucoamylase signal peptide (GSP) of Saccharomyces diastaticus for the secretion of foreign proteins, hybrid plasmids containing one of four types of GSP mutant (m1, Pro(-18)-->Leu(-18); m2, Tyr(-13)-->Leu(-13); m3, Ser(-9)-->Leu(-9); m4, Asn(-5)-->Pro(-5)) were constructed and evaluated in Saccharomyces cerevisiae using Bacillus endo-1,4-beta-D-glucanase (CMCase) as a reporter gene. CMCase secretion by m1, m2 and m3 GSP mutants was increased, likely resulting from a higher probability of the modified GSP to assume an alpha-helical structure. Especially in the case of m3, the substitution of Leu for a polar residue, Ser(-9), in the hydrophobic region resulted in approximately a twofold increase in extracellular CMCase activity. In mutant 4, which disrupts the alpha-helix of GSP, CMCase was less efficiently secreted.

Chlorophyllin suppression of lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells

Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, functions as an anticarcinogen and antioxidant. In the present study, we investigated the effect of CHL on nitric oxide production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Treatment with CHL inhibited nitric oxide production in the LPS-stimulated RAW 264. 7 cells in a dose-related manner. Competitive RT-PCR analysis, using a DNA competitor as an internal standard, demonstrated that the treatment with 1, 10, and 50 microM CHL decreased LPS-induced iNOS mRNA expression in a concentration-dependent manner. Since the expression of the iNOS gene is mainly regulated by NF-kappaB, we then examined the effects of CHL on the NF-kappaB DNA binding activity, using an electrophoretic mobility shift assay. CHL down-regulated the NF-kappaB DNA binding on its cognate recognition site at the concentrations just noted. Employing a transfection and reporter gene expression system with p(NF-kappaB)(3)-chloramphenicol acetyl transferase (CAT), the treatment of CHL produced a dose-dependent inhibition of CAT activity in RAW 264.7 cells. Furthermore, CHL partially restored LPS-decreased IkappaBalpha, an inhibitory protein against NF-kappaB activation, in the cytosolic extract from the LPS-treated cells determined by immunoblot analysis. CHL also protected the hydroxyl radical-induced cytotoxicity in RAW 264.7 cells, indicating its antioxidant effect. These results suggest that CHL suppresses the nitric oxide production and iNOS mRNA expression mediated by the inhibition of NF-kappaB activation, and its action mechanism may be based on its antioxidant effect.

Inhibition of phospholipase cgamma1 and cancer cell proliferation by triterpene esters from Uncaria rhynchophylla

Investigation of the hooks of Uncaria rhynchophylla resulted in isolation of six phospholipase Cgamma1 (PLCgamma1) inhibitors (1-6). The structures of these compounds were elucidated as pentacyclic triterpene esters by spectroscopic and chemical analysis. Three of them, namely uncarinic acids C (1), D (2), and E (3), are newly reported as natural products. All the compounds showed dose-dependent inhibitory activities against PLCgamma1 in vitro with IC(50) values of 9.5-44.6 microM and inhibited the proliferation of human cancer cells with IC(50) values of 0.5-6.5 microg/mL.

Involvement of SH2-SH2-SH3 domain of phospholipase cgamma1 in NF-kappaB signaling

To directly define the role of phospholipase Cgamma1 (PLCgamma1) in NF-kappaB activation, NF-kappaB promoted luciferase reporter gene plasmid (pNF-kappaB-Luc) was transfected into rat-3Y1 fibroblasts that overexpress whole PLCgamma1 (PLCgamma1-3Y1), src homology domains SH2-SH2-SH3 of PLCgamma1 (SH223-3Y1) and v-src (Src-3Y1). Transient transfection with pNF-kappaB-Luc remarkably increased the luciferase activity in all three transformants compared with normal rat-3Y1 cells. Pretreatment with inhibitors of protein tyrosine kinase reduced this increase in luciferase activity, but U73122 (a PLC inhibitor) did not. While PD98059, an inhibitor of mitogen activated protein kinase (MAPK), significantly reduced the luciferase activity, there was no effect by wortmannin and Ro-31-8220, inhibitors of phosphatidylinositol 3-kinase (PI3K) and protein kinase C (PKC), respectively. This study shows a direct evidence that the SH2-SH2-SH3 region of PLCgamma1 contributes to the NF-kappaB signaling and that MAPK, but not PI3K and PKC, is involved in SH2-SH2-SH3 mediated NF-kappaB activation in these cells.

Video assisted thoracoscopic ligation of patent ductus arteriosus. Technique of sliding loop ligation

Variant video-assisted thoracoscopic surgical technique for closure of patent ductus arteriosus has been introduced. Although the endoscopic clipping device may be a preferred method for interruption of the patent ductus arteriosus, there is always the risk of inadequate clip placement and limitation of application in width of ductus arteriosus. In an effort to overcome this problem we have used a self-made endoscopic loop ligation in 10 patients and herein report the method. Only a small window and one port of access are necessary to dissect the patent ductus arteriosus from the surrounding tissues and to apply the extracorporeally created sliding loop. Successful ligation without shunt is obtained in all cases. The technique is simple and safe even in the presence of a wide ductus.

Anti-Helicobacter pylori activity of quinolone alkaloids from Evodiae fructus

A biologically monitored fractionation of methanol extract of the fruit of Evodia rutaecarpa led to the isolation of six quinolone alkaloids, evocarpine (1), 1-methyl-2-[(4Z,7Z)-4,7-tridecadienyl]-4(1H)-quinolone (2), 1-methyl-2-[(6Z,9Z)-6,9-pentadecadienyl]-4(1H)-quinolo ne (3), 1-methyl-2-undecyl-4(1H)-quinolone (4), dihydroevocarpine (5), 1-methyl-2-pentadecyl-4(1H)-quinolone (6). They showed potent anti-Helicobacter pylori activity with the minimum inhibitory concentration (MIC) value of 10-20 microg/ml. However, they had no effect on Helicobacter pylori urease activity at the concentration of 300 microg/ml.

Long-period fiber gratings based on periodic microbends

We demonstrate a new type of high-performance long-period fiber grating based on arc-induced periodic microbends. The fabrication method is simple and does not require special fibers. Flexibility in controlling the filter parameters makes it possible to produce arbitrary filter profiles by use of a simple apodization technique, which is difficult to do with conventional long-period gratings.

Frequency-division-multiplexed polarimetric fiber laser current-sensor array

We demonstrate a novel frequency-domain-multiplexing technique for implementing polarimetric fiber laser current sensors. Each sensor operates at a different polarization-mode beat frequency that is modulated in response to applied electric current. A bank of bandpass filters can be used to separate signals from different sensors. A simple frequency-demodulation technique based on a phase-locked loop is used for signal processing.

pp60v-src reactivation inhibits serum-induced accumulation of inositol phosphates and phosphatidylethanol in tsNRK

In tsRSV-infected NRK (tsNRK) cells, pp60(v-src) reactivation by temperature-shift from a nonpermissive temperature, 39 C, to a permissive one, 32 degrees C, induced the production of inositol phosphates (IPt) and phosphatidylethanol (PEt). This was accompanied by an increase in membrane-associated protein kinase C (PKC) activity in the absence of exogenous growth factors. However, with serum-stimulation, the amounts of IPt and PEt at 32 degrees C were less than those at 39 degrees C. Pretreatment with PKC inhibitors, Ro-31-8220 and staurosporine, enhanced the accumulation of IPt but not of PEt at 32 degrees C. The tyrosine phosphorylation of phospholipase Cgamma1 (PLCgamma1) was increased either by serum or by pp60(v-src) reactivation. These results suggest that serum transduces its signal through PLCgamma1 mediation, and that pp60(v-src), possibly through the PKC mediation, negatively affects serum-induced PLCgamma1 activation.

Induction of seizures by the potent K+ channel-blocking scorpion venom peptide toxins tityustoxin-K(alpha) and pandinustoxin-K(alpha)

The scorpion venom peptide toxins tityustoxin-K(alpha) (TsTx-K(alpha)) and pandinustoxin-K(alpha) (PiTx-K(alpha)) are novel, highly potent and selective blockers of voltage-activated K+ channels. PiTx-K(alpha) preferentially blocks rapidly inactivating (A-type) K+ channels whereas TsTx-K(alpha) is selective for slowly inactivating (delayed rectifier-type) channels. K+ channel blockers are known to induce seizures, but the specific K channel types that can serve as convulsant targets are not well defined. To address this issue, we examined for convulsant activity the K+ channel type-specific scorpion toxins and the selective K+ channel antagonists 4-aminopyridine (4-AP), an inhibitor of A-type voltage-activated K+ channels, and paxilline, a selective blocker of large conductance (maxi K) Ca(2+)-activated K+ channels. Intracerebroventricular injection of recombinant TsTx-K(alpha) and PiTx-K(alpha) in mice produced limbic and clonic-tonic seizures. The severity of the seizures increased during the 60-min period following injection, culminating in continuous clonic seizure activity (status epilepticus), tonic hindlimb extension, and eventually in death. The estimated doses producing limbic and clonic seizures in 50% of animals (CD50) for TsTx-K(alpha) and PiTx-K(alpha) were 9 and 33 ng, respectively. 4-AP produced seizure activity similar to the toxins (CD50, 76 ng) whereas paxilline failed to induce seizures at doses up to 13.5 microg. Carbamazepine protected fully against the toxin- and 4-AP-induced seizures whereas phenytoin had variable activity against the clonic component although it was protective against tonic hindlimb extension. The AMPA receptor antagonist GYKI 52466 also conferred full protection against toxin-induced seizures, but the NMDA receptor antagonists (R)-CPP and dizocilpine failed to affect limbic and clonic seizures, although they protected against hindlimb extension. We conclude that selective blockade of delayed rectifier- or A-type voltage-activated K+ channels can produce limbic, clonic and tonic seizures, whereas blockade of maxi K-type Ca(2+)-activated K+ channels does not. The convulsant effects may be related to enhanced glutamate release and, in the case of the limbic and clonic convulsions, activation of AMPA receptors.

Up-regulation of glial cell line-derived neurotrophic factor (GDNF) expression in regenerating muscle fibers in neuromuscular diseases

Glial cell line-derived neurotrophic factor (GDNF) has been shown to exert a target-derived trophic factor for motor neurons. Immunohistochemical analyses revealed that expression of GDNF in regeneration muscle fibers was up-regulated in polymyositis (PM) and Duchenne type muscular dystrophy (DMD). Reverse transcriptase polymerase chain reaction (RT-PCR) analyses showed that the full length GDNF was up-regulated in PM and DMD muscle; normal muscle exhibited mostly truncated GDNF. The results indicate that the GDNF expression is regulated in regeneration of human skeletal muscle.

Neonatal cryoanesthesia affects the morphology of the visual cortex in the adult rat

Hypothermia is often employed as an anesthetic for manipulations of neonatal animals. We previously reported [J. Nuñez, J.M. Juraska, The effect of neonatal cryoanesthesia on the gross size of the splenium of the corpus callosum, Dev. Psychobiol. 30 (1997) 259; J. Nuñez, J.M. Juraska, The size of the splenium of the rat corpus callosum: influence of hormones, sex ratio and neonatal cryoanesthesia, Dev. Psychobiol., in press.] that the area of the splenium of the adult rat corpus callosum negatively correlated with the time neonatal pups spent in the cold. In the present study, we examined the effect of exposure to neonatal hypothermia (0, 15, 30 and 60 min at 4 degreesC, within 2 h of birth) on the thickness and volume of the binocular (Oc1B) and monocular (Oc1M) fields of the adult rat visual cortex. The number of neurons and glia in layer 2/3 in these areas was also assessed in the 0 and 60 min cold-exposed groups. Cryoanesthesia significantly decreased the length, thickness, volume and number of neurons and glia in both Oc1M and Oc1B. We also observed significant effects of cold exposure on the thickness of individual cortical layers, with some layers affected more than others after differential exposure times. Sex differences (males greater than females) were observed in a number of measures after varying amounts of time in cold and in the absence of cold exposure, in confirmation of previous work from our lab [S.N.M. Reid, J.M. Juraska, Sex differences in the gross size of the rat neocortex, J. Comp. Neurol. 321 (1992) 442-447; S.N.M. Reid, J.M. Juraska, Sex differences in neuron number in the binocular area of the rat visual cortex, J. Comp. Neurol. 321 (1992) 448-455.]. The present study points to the potential confound of using cryoanesthesia on neonatal animals to study cortical structure or function.

Post-liver transplantation myocardial dysfunction

Patients with end-stage liver disease usually show a hyperdynamic circulatory state. It has previously been reported that patients who develop myocardial depression in the early post-liver transplantation period are more prone to organ failure and death. We reviewed the records of 754 adult patients undergoing liver transplantation at our institution and identified 7 patients who initially showed hyperdynamic circulation, but then developed reversible dilated cardiomyopathy in the early posttransplantation period. All identifiable causes of cardiac dysfunction, such as myocardial ischemia, thyroid dysfunction, and electrolyte imbalances, were excluded. Left ventricular ejection fraction decreased from a preoperative median baseline of 60% to 20% (P = .02), with four-chamber dilatation on echocardiogram. All these patients required supportive care, including mechanical ventilation, afterload reduction, inotropic support, and monitoring in the intensive care unit. Cardiac function subsequently improved in all patients, with ejection fraction increasing to a median of 50%. All patients were discharged from the hospital. At a median follow-up of 15 months, there was no recurrence of heart failure. The increased peripheral resistance seen after successful liver transplantation may be an important causative factor.

Interrogation of fiber grating sensor arrays with a wavelength-swept fiber laser

We demonstrate a novel application of a wavelength-swept fiber laser to fiber Bragg grating sensor-array interrogation. The laser provides high signal powers of >3 mW with <0.1-nm spectral resolution over a 28-nm wavelength span. Using time-interval counting, we demonstrate static-dynamic strain measurements with a resolution of 0.47mu? rms at a sampling rate of 250 Hz.

[Facioscapulohumeral muscular dystrophy (FSHD)]

Facioscapulohumeral muscular dystrophy (FSHD; MIM 158900) is one of the major forms of muscular dystrophy, and is inherited in an autosomal dominant fashion. In most patients with FSHD, deletion of 3.3 kb tandemly repeated units within the EcoRI fragment, as detected by p13E-11 (D4F104S1) on chromosome 4q35, is associated with the disease (FSHD1A or 4q35-FSHD). Rare (< 5%) 4q35-unlinked FSHD (FSHD1B) is also known, and therefore genetic heterogeneity exists among FSHD. Recent studies based on the distinction of 4q35 EcoRI fragments from those of 10q26 improved the reliability of molecular diagnosis of the disease (> 95% accuracy). However, gene for FSHD1A has not been identified yet. Identification of the FSHD gene and characterization of the gene product are waited on tiptoe with expectation.