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.     

Cadmium-induced changes in antioxidant enzyme activities in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L. cv. Dongjin)

We studied how the relationship between cadmium (Cd) toxicity and oxidative stress influenced the growth, photosynthetic efficiency, lipid peroxidation, and activity of ntioxidative enzymes in the roots and leaves of rice(Oryza sativa L Dongjin). Plants were exposed to Cd for 21 d. Both seedling growth and photosynthetic efficiency decreased gradually with increasing cadmium concentrations. Lipid peroxidation increased slowly in both roots and leaves, causing oxidative stress. However, each tissue type responded differently to Cd concentrations with regard to the induction/ inhibition of antioxidative enzymes. The activity of Superoxide dismutase (SOD) increased in both roots and leaves. Ascorbate peroxidase (APX) activity increased in leaves treated with up to 0.25 μM Cd, then decreased gradually at higher concentrations. In contrast, APX activity in roots increased and remained constant between 0.25 and 25 μM Cd. Enhanced peroxidase (POD) activity was recorded for treatments with up to 25/M Cd, gradually decreasing at higher concentrations in the leaves but remaining unchanged in the roots. Catalase (CAT) activity increased in the roots, but decreased in the leaves, whereas the activity of glutathione reductase (GR) was enhanced in both roots and leaves, where it remained elevated at higher Cd concentrations. These results suggest that rice seedlings tend to cope with free radicals generated by Cd through coordinated, enhanced activities of the antioxidative enzymes involved in detoxification.     

Production of monoclonal antibodies and immunohistochemical studies of brain myo-inositol monophosphate phosphatase

Five monoclonal antibodies that recognize porcine brain myo-inositol monophosphate phosphatase (IMPase) have been selected and designated as mAb IMPP 9, IMPP 10, IMPP 11, IMPP 15, and IMPP 17. These antibodies recognize different epitopes of the enzyme and one of these inhibited the enzyme activity. When the total proteins of the porcine brain homogenate separated by SDS-PAGE were probed with monoclonal antibodies, a single reactive protein band of 29 kDa, co-migrating with the purified porcine brain IMPase, was detected. Using the anti-IMPase antibodies as probes, the cross reactivities of the brain IMPase from human and other mammalian tissues, as well as from avian sources, were investigated. Among the human and animal tissues tested, the immunoreactive bands on Western blots appeared to have the same molecular mass of 29 kDa. In addition, there was IMPase immunoreactivity in the various neuronal populations in the rat brain. These results indicate that mammalian brains contain only one major type of immunologically similar IMPase, although some properties of the enzymes that were previously reported differ from each another. The first demonstration of the IMPase localization in the brain may also provide useful data for future investigations on the function of this enzyme in relation to various neurological diseases.     

Dysfunction of rat liver mitochondria by selenite: induction of mitochondrial permeability transition through thiol-oxidation

Selenium is an essential trace element in mammals and is thought to play a chemopreventive role in human cancer, possibly by inducing tumor cell apoptosis. Mitochondria play a pivotal role in the induction of apoptosis in many cell types. The effects of selenite on mitochondrial function were therefore investigated. Selenite induced the oxidation and cross-linking of protein thiol groups, mitochondrial permeability transition (MPT), a decrease in the mitochondrial membrane potential, and the release of cytochrome c in mitochondria isolated from rat liver. Induction of the MPT by selenite was prevented by cyclosporin A, EGTA, or N-ethylmaleimide. These results thus indicate that selenite induces the MPT as a result of direct modification of protein thiol groups, resulting in the release of cytochrome c and a loss of mitochondrial membrane potential.     

Simulation on long-term operation of an anaerobic bioreactor for Korean food wastes

A mathematical model was formulated to simulate the long-term performance of an anaerobic bioreactor designed to digest Korean food wastes. The system variables of various decomposition steps were built into the model, which predicts the temporal characters of solid waste, and volatile fatty acid (VFA) in the reactor, and gas production in response to various input loadings and temperatures. The predicted values of VFA and gas production were found to be in good agreement with experimental observations in batch and repeated-input systems. Finally, long-term reactor performance was simulated with respect to the seasonal temperature changes from 5°C in winter to 25°C in summer at different food waste input loadings. The simulation results provided us with information concerning the success or failure of a process during long-term operation.     

Stilbenes from the roots of Pleuropterus ciliinervis and their antioxidant activities

Two stilbene glycosides, pieceid-2"-O-gallate and pieceid-2"-O-coumarate, were isolated from the MeOH extract of the roots of Pleuropterus ciliinervis Nakai (Polygonaceae), together with two known compounds, resveratrol and pieceid. Their structures were determined spectroscopically, particularly by 2D NMR spectroscopic analysis. The antioxidant activities of stilbenes isolated were determined in vitro against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide radicals and by determining their lipid peroxidation inhibitory activities. Among the compounds isolated, pieceid-2"-O-gallate had the most potent inhibitory scavenging effect on DPPH, superoxide radicals and upon lipid peroxidation inhibition with IC50 values of 16.5, 23.9 and 5.1 microM, respectively.     

Changes in lignin content of leaf litters during mulching

Alkaline nitrobenzene oxidation, ozonation and methoxyl content determinations were applied to decomposing leaf litter of Ginkgo biloba L., Cinnamomum camphora sieb., Zelkova serrata Makino and Firmiana simplex W. F. Wight, respectively, during mulching to investigate the properties and estimate changes in lignin composition and content. Since the Klason lignin residue originated from components highly resistant to degradation by acid, the methoxyl content of Klason residue was used to estimate the lignin content of leaf litter. Quantitative analysis of presumed lignin-derived fragments, by use of alkaline nitrobenzene oxidation and ozonation methods, suggested that the estimated lignin content approximates that of the real lignin content of leaves, which is greatly overestimated by the Klason procedure. The estimated lignin contents ranged from 3.9 to 10.0% while the Klason lignan residue varied from 37.1 to 46.7% in un-mulched leaf litter. The absolute amounts of the measured lignin somewhat decreased during mulching, while the structure of lignin remaining in leaf litters after mulching was considered not to be very different from its original structure.