Clinical Features and Treatment Modes of Mandibular Fracture at the Department of Oral and Maxillofacial Surgery,Shimane University Hospital,Japan

Background

The number of elderly patients with maxillofacial trauma is rapidly increasing due to active lifestyles and longevity. Shimane prefecture has the fastest growing proportion of elderly individuals in Japan. The aim of this study was to reveal the distinctive features and treatment modes of mandibular fracture treatment mode in patients requiring hospitalization at the Department of Oral and Maxillofacial Surgery, Shimane University Hospital, Japan.

Patients and Methods

Patient age, sex, period between injury and first consultation, years since injury, cause of injury, fracture site, treatment, and duration of hospitalization were evaluated. Univariate Poisson regression, relative risk with 95% confidence interval based on the Wald test, Fisher’s exact test, and Kruskal-Wallis test were used to explore associations among clinical and demographic variables.

Results

In total, 305 patients were diagnosed with and hospitalized for mandibular fracture from 1980 to 2010. Younger age increased the risk for mandibular fracture. Incidence was higher in males than females, particularly in the young, but the male to female ratio decreased with age. The period until first hospital consultation decreased progressively over the study period. Fall was a much more frequent cause in patients aged ≥60 than in those aged <60 years. Mandibular fracture with condyle, symphysis, and angle involvement were most common and were associated with sex, age, and treatment mode. Length of hospitalization has decreased since 1980.

Conclusion

In our department, patients aged ≥60 years accounted for a greater proportion of mandibular fracture cases than in many previous studies, reflecting the greater proportion of elderly residents in Shimane prefecture.     

Adaptive Responses Limited by Intrinsic Noise

Sensory systems have mechanisms to respond to the external environment and adapt to them. Such adaptive responses are effective for a wide dynamic range of sensing and perception of temporal change in stimulus. However, noise generated by the adaptation system itself as well as extrinsic noise in sensory inputs may impose a limit on the ability of adaptation systems. The relation between response and noise is well understood for equilibrium systems in the form of fluctuation response relation. However, the relation for nonequilibrium systems, including adaptive systems, are poorly understood. Here, we systematically explore such a relation between response and fluctuation in adaptation systems. We study the two network motifs, incoherent feedforward loops (iFFL) and negative feedback loops (nFBL), that can achieve perfect adaptation. We find that the response magnitude in adaption systems is limited by its intrinsic noise, implying that higher response would have higher noise component as well. Comparing the relation of response and noise in iFFL and nFBL, we show that whereas iFFL exhibits adaptation over a wider parameter range, nFBL offers higher response to noise ratio than iFFL. We also identify the condition that yields the upper limit of response for both network motifs. These results may explain the reason of why nFBL seems to be more abundant in nature for the implementation of adaption systems.     

Involvement of androgen receptor and glucose-regulated protein 78 kDa in human hepatocarcinogenesis

Previous studies demonstrated that androgen receptor (AR) is expressed in human hepatocellular carcinoma (HCC), one of the male-dominant diseases. Glucose-regulated protein 78 kDa (GRP78/Bip), which has a role in cancer development, is one of the androgen response genes in prostate cell lines. The aim of this study was to investigate the impact of AR on endoplasmic reticulum (ER)-stress signaling in human hepatoma. AR and GRP78 expressions were examined in human liver tissue panels. Human hepatoma cells stably expressing short hairpin RNA targeting AR and cells over-expressing AR were generated. The expressions of ER-stress molecules and AR were measured by real-time RT-PCR and Western blotting. The effect of AR on ER-stress responsive gene expression was examined by reporter assay. Strong positive correlation between AR mRNA and GRP78 mRNA was observed in stage I/II-HCCs. AR enhanced ER-stress responsive element activities and GRP78 expression, and regulated ER-stress response in hepatocytes. Sorafenib strongly induced significant apoptosis in HepG2 cells by the inhibition of AR and inhibition of the downstream GRP78. AR seems a co-regulator of GRP78 especially in earlier-stage HCC. AR plays a critical role in controlling ER-stress, providing new therapeutic options against HCC.     

Effects of nitrite inhibition on anaerobic ammonium oxidation

In order to assess the stability of nitrogen removal systems utilizing anaerobic ammonium oxidation (anammox), it is necessary to study the toxic effects of nitrite on these biochemical reactions. In this study, the effects of nitrite on anammox bacteria entrapped in gel carriers were investigated using batch and continuous feeding tests. The results showed that the nitrite concentration in a reactor must be less than 274-mg N/L in order to prevent a decrease in the anammox activity, which occurred when the gel carriers were soaked in nitrite solutions with concentrations greater than 274-mg N/L in a batch test. In a continuous feeding test, nitrite inhibition was not observed at low concentrations of nitrite. However, the anammox activity decreased to 10% when the nitrite concentration increased to 750-mg N/L over a 7-day period in the reactor. In addition, it was shown that the effects of nitrogen on the anammox reaction were reversible because the anammox activity completely recovered within 3 days when the influent nitrite concentration was decreased to less than 274-mg N/L.     

High-rate nitrogen removal from livestock manure digester liquor by combined partial nitritation–anammox process

In this study, combination of a partial nitritation reactor, using immobilized polyethylene glycol (PEG) gel carriers, and a continuous stirred granular anammox reactor was investigated for nitrogen removal from livestock manure digester liquor. Successful nitrite accumulation in the partial nitritation reactor was observed as the nitrite production rate reached 2.1 kg-N/m³/day under aerobic nitrogen loading rate of 3.8 kg-N/m³/day. Simultaneously, relatively high free ammonia concentrations (average 50 mg-NH₃/l) depressed the activity of nitrite oxidizing bacteria with nitrate concentration never exceeding 3% of TN concentration in the effluent of the partial nitritation reactor (maximum 35.2 mg/l). High nitrogen removal rates were achieved in the granular anammox reactor with the highest removal rate being 3.12 kg-N/m³/day under anaerobic nitrogen loading rate of 4.1 kg-N/m³/day. Recalcitrant organic compounds in the digester liquor did not impair anammox reaction and the SS accumulation in the granular anammox reactor was minimal. The results of this study demonstrated that partial nitritation–anammox combination has the potential to successfully remove nitrogen from livestock manure digester liquor.     

2-Haloacrylate Hydratase,a New Class of Flavoenzyme That Catalyzes the Addition of Water to the Substrate for Dehalogenation

Enzymes catalyzing the conversion of organohalogen compounds are useful in the chemical industry and environmental technology. Here we report the occurrence of a new reduced flavin adenine dinucleotide (FAD) (FADH₂)-dependent enzyme that catalyzes the removal of a halogen atom from an unsaturated aliphatic organohalogen compound by the addition of a water molecule to the substrate. A soil bacterium, Pseudomonas sp. strain YL, inducibly produced a protein named Caa67_YL when the cells were grown on 2-chloroacrylate (2-CAA). The caa67_YL gene encoded a protein of 547 amino acid residues (M_r of 59,301), which shared weak but significant sequence similarity with various flavoenzymes and contained a nucleotide-binding motif. We found that 2-CAA is converted into pyruvate when the reaction was carried out with purified Caa67_YL in the presence of FAD and a reducing agent [NAD(P)H or sodium dithionite] under anaerobic conditions. The reducing agent was not stoichiometrically consumed during this reaction, suggesting that FADH₂ is conserved by regeneration in the catalytic cycle. When the reaction was carried out in the presence of H₂¹⁸O, [¹⁸O]pyruvate was produced. These results indicate that Caa67_YL catalyzes the hydration of 2-CAA to form 2-chloro-2-hydroxypropionate, which is chemically unstable and probably spontaneously dechlorinated to form pyruvate. 2-Bromoacrylate, but not other 2-CAA analogs such as acrylate and methacrylate, served as the substrate of Caa67_YL. Thus, we named this new enzyme 2-haloacrylate hydratase. The enzyme is very unusual in that it requires the reduced form of FAD for hydration, which involves no net change in the redox state of the coenzyme or substrate.Dehalogenases catalyze the removal of halogen atoms from organohalogen compounds. These enzymes have been attracting a great deal of attention partly because of their possible applications to the chemical industry and environmental technology. Several dehalogenases have been discovered and characterized (6, 11, 14, 17, 22). Some of them act on unsaturated aliphatic organohalogen compounds in which a halogen atom is bound to an sp²-hybridized carbon atom. Examples include various corrinoid/iron-sulfur cluster-containing reductive dehalogenases (1, 7), cis- and trans-3-chloroacrylic acid dehalogenases (4, 19), and LinF (maleylacetate reductase), which acts on 2-chloromaleylacetate (5).In order to gain more insight into the enzymatic dehalogenation of unsaturated aliphatic organohalogen compounds, we searched for microorganisms that dissimilate 2-chloroacrylate (2-CAA) as a sole source of carbon and energy (8). 2-CAA is a bacterial metabolite of 2-chloroallyl alcohol, an intermediate or by-product in the industrial synthesis of herbicides (26). Rats treated orally with the herbicides sulfallate, diallate, and triallate excrete urinary 2-CAA (16). Various halogenated acrylic acids are produced by a red alga (27). We obtained three 2-CAA-utilizing bacteria as a result of screening (8). For one of these bacteria, Burkholderia sp. strain WS, we previously discovered a new NADPH-dependent enzyme, 2-haloacrylate reductase (12, 13). Although this enzyme does not directly remove a halogen atom from the substrate, it is supposed to participate in the metabolism of 2-CAA by catalyzing the conversion of 2-CAA into l-2-chloropropionate, which is subsequently dehalogenated by l-2-haloacid dehalogenase.Another bacterium that we obtained, Pseudomonas sp. strain YL, also dissimilates 2-CAA. However, the metabolic fate of 2-CAA in this bacterium remains unclear. In the present study, we analyzed proteins from 2-CAA- and lactate-grown cells of Pseudomonas sp. YL by two-dimensional polyacrylamide gel electrophoresis (PAGE) and identified a 2-CAA-inducible protein. We found that the protein catalyzes the dehalogenation of 2-CAA by the addition of a water molecule to the substrate, representing a new family of dehalogenases that act on unsaturated aliphatic organohalogen compounds. Remarkably, the enzyme requires reduced flavin adenine dinucleotide (FAD) (FADH₂) for its activity, although the reaction does not involve a net change in the redox state of the coenzyme or substrate. Here we describe the occurrence and characteristics of this unusual flavoenzyme.     

Efficiently differentiating vascular endothelial cells from adipose tissue-derived mesenchymal stem cells in serum-free culture

Adipose tissue-derived mesenchymal stem cells (ASCs) have been reported to be multipotent and to differentiate into various cell types, including osteocytes, adipocytes, chondrocytes, and neural cells. Recently, many authors have reported that ASCs are also able to differentiate into vascular endothelial cells (VECs) in vitro. However, these reports included the use of medium containing fetal bovine serum for endothelial differentiation. In the present study, we have developed a novel method for differentiating mouse ASCs into VECs under serum-free conditions. After the differentiation culture, over 80% of the cells expressed vascular endothelial-specific marker proteins and could take up low-density lipoprotein in vitro. This protocol should be helpful in clarifying the mechanisms of ASC differentiation into the VSC lineage.     

ISOLATION AND REGENERATION OF HAPLOID PROTOPLASTS FROM BANGIA ATROPURPUREA (RHODOPHYTA) WITH MARINE BACTERIAL ENZYMES1

Three kinds of enzymes, agarase, β-1,4-mannanase, and β-1,3-xylanase, required for isolation of protoplasts from the red alga Bangia atropurpurea (Roth) C. Ag. were prepared from bacterial culture fluids of Vibrio sp. PO-303, Vibrio sp. MA-138, and Alcaligenes sp. XY-234, respectively, isolated from the sea environment. The optimal pH of all enzymes was around 7.5. Suitable conditions for protoplast isolation from B. atropurpurea were examined. The pretreatment of the fronds with pa-pain solution (20 mM Mes buffer, pH 7.5, containing 2% papain and 0.5 M mannitol) contributed to successful protoplast isolation. When razor-cut fragments of the fronds (about 200 mg in fresh weight) immersed in 20 mM Mes buffer, 7.5, containing 0.5 M mannitol and one unit each of agarase, β-1,4-mannanase, and β-1,3-xylanase were incubated at 22°C for 90 min with gentle agitation, 5.7 × 10⁶ protoplasts were released from them. Many protoplasts regenerated into fronds of regular or irregular shape.     

Oviposition-stimulatory activity of phenanthroindolizidine alkaloids of host-plant origin to a danaid butterfly, Ideopsis similis

Oviposition response of Ideopsis similis (L.) (Lepidoptera: Danaidae) was examined for 12 phenanthroindolizidine alkaloids present in its host plant, Tylophora tanakae (Maxim.) (Asclepiadaceae). At least five alkaloids, i.e. (+)‐isotylocrebrine (3,4,6,7‐tetramethoxyphenanthroindolizidine; l ), (+)‐3‐demethyliso‐ tylocrebrine ( 3 ), (+)‐isotylocrebrine N‐oxide ( 5 ), (+)‐6‐demethyltylocrebrine ( 8 ) and (–)‐7‐demethyltylophorine ( 10 ), were found to individually stimulate oviposition by females. Of these, compounds 1, 3 and 10 were regarded as key components most responsible for host recognition or preference. However, female egg‐laying was much higher in response to a mixture of the five alkaloids. In two‐choice bioassays, more eggs were deposited on samples comprising the five alkaloids than on samples consisting of a single alkaloid. This suggests strongly that host selection by the butterfly is mediated by the synergistic action of several phenanthroindolizidine alkaloids present in the host plant.