Extremely low frequency magnetic field effects on premorbid behaviors produced by cocaine in the mouse

We investigated the premorbid behavioral changes produced by the administration of cocaine and acute exposure to extremely low frequency (ELF) magnetic field (MF) in the mouse. ICR mice received intraperitoneal injections of cocaine at two doses (65 and 70 mg/kg) and were subsequently exposed to one of eight ELF-MF fields (2, 3, 4, 8, 10, 15, 25, or 60 Hz) of about 20 G (2 mT) intensity immediately after injection. Twelve mice were used for each of applied cocaine dose and ELF-MF level. For a given dose of cocaine, the applied MF frequencies were randomly ordered, and blind tests were carried out in which the behavior observer did not know the frequencies of MF. The premorbid behaviors were defined in the ICR mice and their changes were observed over the exposure of various ELF-MFs. Our data show that the onset times of stop rearing and tonic-clonic seizure in the 4 Hz MF exposure group are significantly different from those of the sham group.     

Isoform-specific induction of PKC-epsilon by high glucose protects heart-derived H9c2 cells against hypoxic injury

We investigated which PKC isoforms are involved in high glucose-induced protection against hypoxic injury. Treatment for 48 h with high glucose (22 mM) markedly increased the expression of PKC- epsilon in the particulate fraction (213+/-22.1% of the control) but had no effect on other types of PKC isoforms, suggesting that the high glucose-induced increase in PKC expression is isoform-specific. The mRNA level for PKC- epsilon was also substantially increased, reaching its peak after 4h of high glucose treatment. The high glucose increased PKC-epsilon activity in the particulate fraction up to 183+/-32.2% of the control. During hypoxia, the amount of PKC-epsilon in the particulate fraction was remarkably diminished in the low glucose-treated cells, but remained at a higher level in high glucose-treated cells. The treatment with epsilon V1-2 (10 microM), a specific inhibitor of PKC epsilon, abolished the protective effect of high glucose against hypoxia. These results suggest that isoform-specific induction of PKC-epsilon is involved in high glucose-induced protection against hypoxic injury in heart-derived H9c2 cells.     

Role of BMP, betaig-h3, and chitosan in early bony consolidation in distraction osteogenesis in a dog model

The purpose of this investigation was to study the effect of bone morphogenetic protein (BMP), transforming growth factor beta-induced gene h3 (betaig-h3), and chitosan on early bony consolidation in distraction osteogenesis in a dog model. Sixteen dogs were used for this study. The lateral surface of the mandibular body was exposed in the subperiosteal plane and the vertical osteotomy on the mandibular body was extended downward. An external distraction device was applied to the mandibular body, and the mandibular distraction was started 5 days after the operation at a rate of 2 mm/day up to a 10-mm distraction after 5 days. The experimental group was then divided into a control group, a BMP group, a betaig-h3 group, and a chitosan group, depending on the type of implantation material used in the distracted area. On the same day after completing the distraction, BMP, betaig-h3, or chitosan was implanted into the distracted area. No material was implanted into the distracted area in the control group. After implanting the materials, the distraction device was left in place for 7 weeks to allow for bony consolidation. Four dogs were allocated to each group. Two dogs in each group, a total of eight dogs, were killed 4 weeks after completing the distraction and the other eight dogs were killed after 7 weeks. Serial radiographs were obtained every week after completing the distraction. New bone was generated in the distracted zone in all groups. In the BMP group, the formation of active woven bone was observed throughout the distracted zone, and the new bone appeared to be nearly normal cortical bone 7 weeks after implantation. In the betaig-h3 and chitosan groups, the development of new bone was observed in the distracted zone after 7 weeks; however, the amount was less than that in the BMP group. In the control group, the new bone was observed at the edges of the distracted zone. These findings suggest that BMP seems to be very effective in early bony consolidation in distraction osteogenesis.     

Monitoring flap for buried free tissue transfer: its importance and reliability

To improve the success rate of microsurgical flap transfers into a buried area, it is important to monitor the circulation of the flap during the early stage. A monitoring flap includes such advantages as simplicity, reliability, noninvasiveness, and the ability to continuously monitor the vascular status of various buried flaps. This article describes experiences related to the importance and reliability of a monitoring flap. A total of 109 flaps in 99 patients were treated with buried free flaps, including a monitoring flap, between 1990 and 1999. Forty-nine patients received a tubed free radial forearm flap with a skin-monitoring flap, and six received a free jejunal flap with a jejunal segment monitoring flap for the reconstruction of the esophagus. Vascularized fibular grafts with a skin monitoring flap or peroneus longus muscle monitoring flap were used for reconstructing the mandible in six patients and for treating osteonecrosis of the femoral head in 48 flaps in 38 patients. Monitoring flap abnormalities were indicated in 14 flaps; therefore, immediate revisions were performed on the pedicle of the monitoring flap and microanastomosis site. Among these 14 flaps, nine showed true thrombosis and five showed false-positive thrombosis. Among the nine flaps that showed true thrombosis, five were salvaged and four were finally lost. The false-positive thrombosis in the five flaps was attributed to torsion or tension of the perforator of the monitoring flap in three flaps, an unclear determination in one flap because the monitoring flap size was too small, and damage to the perforator in the last flap. The total thrombosis rate was 8.3 percent (nine of 109), and the failure rate of the free tissue transfer was 3.7 percent (four of 109). The overall sensitivity of the monitoring flap was 100 percent, the predictive value of a positive test was 64 percent (nine of 14), and false-positive results occurred in 36 percent (five of 14). The salvage rate was 55.6 percent. To improve the reliability of a monitoring flap, it is recommended that the size of the flap be larger than 1 x 2 cm to assess the arterial status, and that a perforator with the appropriate caliber be selected. When a monitoring flap is fixed to a previous incision line or a newly created wound, any torsion or tension of the perforator should be avoided. In conclusion, the current results suggest that a monitoring flap is a simple, extremely useful, and reliable method for assessing the vascular status of a buried free flap.     

Multiple virus resistance in transgenic plants conferred by the human dsRNA-dependent protein kinase

We have developed a new strategy for engineering resistance to multipleviruses in plants. The strategy exploits the human double stranded (ds)RNA-dependent protein kinase (PKR). PKR is one of theinterferon-induced enzymes. It confers viral resistance in mammals byinhibitingviral replication through the inactivation of the translational initiationfactor, eIF-2, upon activation by dsRNA. The humanPKR gene was fused to the promoter of theArabidopsis blue copper binding protein gene(BCB) that is induced rapidly in response to wounding. Thechimeric gene cassette was introduced into tobacco plants. Expression of thePKR gene in transgenic tobacco plants was demonstrated byRNA gel blot analysis and autophosphorylation assay of anM _r 68,000 protein. The transgenic plantsexpressing the PKR gene showed significantly reduced viralsymptoms or no viral symptoms at all, when challenged by different plant RNAviruses, such as Cucumber mosaic virus, Tobaccoetch virus, or Potato virus Y. Thus, expressionof a single component in the human interferon pathway, thePKR gene, can effectively confer resistance to multipleviruses in transgenic plants.     

Seasonal variations in yields of Hwangchil lacquer and major sesquiterpene compounds from selected superior individuals of<Emphasis Type="Italic">Dendropanax morbifera</Emphasis> Lév.

We studied fluctuations in the production of Hwangchil lacquer and major essential oils byDendropanax morbifera Lev. Considerable seasonal as well as intraspecific (individual-tree) variations were observed. Yields of Hwangchil lacquer as well as ß-elemene, α-selinene, ß-selinene, germacrene D, and δ-cadinene also depended on harvesting time, with levels being generally higher in July and August.     

Identification by the phage-display technique of peptides that bind to H7 flagellin of Escherichia coli

The four peptides interacting with H7 flagellin of Escherichia coli were selected from a phage display library. The library was selected four times, and the interacting phage peptides were competitively eluted with H7 flagellin. An enzyme-linked immunosorbent assay (ELISA) showed that these peptides were reactive with the H7 flagellin in a dose-dependent manner. Among them, a D1 phage clone showed the highest binding affinity to the H7 flagellin. We synthesized the D1 peptide (LHIHRPTLSIQG) corresponding to the peptide-encoding region of the D1 phage clone. The synthetic peptide showed micro-molar affinity (EC(50) value=1.9 microM) for the H7 flagellin. Furthermore, this D1 peptide interacted more specifically with the H7 flagellin than with the other flagellins (H1, H5, H12, or H23) of E. coli. In situ hybridization clearly showed that the peptide only detected those cells harboring the H7 flagellin gene (fliC). The peptide may specifically bind to the H7 flagellin on the cell surface. These results suggest that the phage-display technique could be used as a tool for identifying peptides as an alternative to using a ligand as a diagnostic reagent in food products or in clinical testing.     

High glucose enhances IL-1beta-induced cyclooxygenase-2 expression in rat vascular smooth muscle cells

The changes in vascular prostaglandin production are implicated in the derangement of vascular reactivity in diabetes. However, the mechanism of altered prostaglandin (PG) production in diabetes is largely unknown. In this study, we investigated the effect of high glucose on IL-1beta-induced PG production and the possible underlying mechanism in cultured vascular smooth muscle cell (VSMC). High glucose evoked an augmentation of IL-1beta-induced PG synthesis in a dose dependent manner and enhanced cyclooxygenase (COX) activity, which reached to maximum at 8-12 hours after stimulation. Western blot analysis supported the activity data. Protein kinase C (PKC) inhibitors, H-7 and chelerythrine, significantly inhibited the enhancement of IL-1beta-induced COX-2 expression by high glucose. The activation of PKC by PMA resulted in marked increase of PG production in low glucose group, whilst this was not the case in high glucose group. Furthermore, glucose-enhancing effect was significantly suppressed by zopolrestat, an aldose reductase inhibitor, and sodium pyruvate. These results suggest that the augmenting effect of high glucose on IL-1beta-induced PG production and COX-2 expression is, at least in part, due to increased glucose metabolism via sorbitol pathway following PKC activation.     

Metabolic Dysfunction in Familial, but Not Sporadic, Amyotrophic Lateral Sclerosis

Abstract: Autosomal dominant familial amyotrophic lateral sclerosis (FALS) is associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1). Previous studies have implicated the involvement of metabolic dysfunction in ALS pathogenesis. To further investigate the biochemical features of FALS and sporadic ALS (SALS), we examined SOD activity and mitochondrial oxidative phosphorylation enzyme activities in motor cortex (Brodmann area 4), parietal cortex (Brodmann area 40), and cerebellum from control subjects, FALS patients with and without known SOD mutations, SALS patients, and disease controls (Pick's disease, progressive supranuclear palsy, diffuse Lewy body disease). Cytosolic SOD activity, predominantly Cu/Zn SOD, was decreased ∼50% in all regions in FALS patients with SOD mutations but was not significantly altered in other patient groups. Marked increases in complex I and II–III activities were seen in FALS patients with SOD mutations but not in SALS patients. We also measured electron transport chain enzyme activities in a transgenic mouse model of FALS. Complex I activity was significantly increased in the forebrain of 60-day-old G93A transgenic mice overexpressing human mutant SOD1, relative to levels in transgenic wild-type animals, supporting the hypothesis that the motor neuron disorder associated with SOD1 mutations involves a defect in mitochondrial energy metabolism.