LncRNA Lethe protects sepsis-induced brain injury via regulating autophagy of cortical neurons

OBJECTIVE

To investigate the role of long non-coding RNA (lncRNA) Lethe in mediating autophagy of cortical neurons in mice with sepsis-induced brain injury (SIBI).

MATERIALS AND METHODS

A total of 60 wild-type C57BL/6 mice were divided into sham-operated wild-type (SWT) group and wild-type model (MWT) group. Sixty Lethe-/- mice were divided into sham-operated knockout (SKO) group and model knockout (MKO) group. Each group had 30 mice. Sepsis model in mice was established by cecal ligation and puncture (CLP). Neurobiological score was recorded at 6 h after CLP. Mice with lower than 6 scores of neurobehavioral tests were diagnosed with SIBI. Quantitative Real-time polymerase chain reaction (qRT-PCR) was performed to determine mRNA levels of Lethe and interferon-γ (INF-γ) in cortical neurons of SIBI mice. Western blot was conducted to detect protein levels of LC3-II, LC3-I and SQSTM1 in mice. Neuronal impairment in mouse brain was evaluated by hematoxylin and eosin (HE) staining.

RESULTS

Expressions of LC3-I and LC3-II in cerebral cortex of MWT group began to increase at 6 h after CLP, and remained at high levels until 96 h. On the contrary, SQSTM1 expression in cerebral cortex of MWT group began to decrease at 6 h after CLP. Compared with SWT group, expressions of Lethe and IFN-γ were remarkably upregulated in cortex of MWT group at 12 h after CLP. Expression of LC3-II in MWT group was remarkably upregulated, while SQSTM1 was downregulated at 12 h after CLP, which were contrary to those in MKO group. At 12 h after CLP, the neurobiological scores of the MKO group (4.97±0.71) were markedly lower than those of the MWT group (5.43±0.86). HE staining showed worse damage in cerebral cortex and fewer neurons of MKO group relative to MWT group.

CONCLUSIONS

Lethe has a protective effect on SIBI mice by regulating autophagy in mouse cortical neurons.

High consumption of sucrose induces DNA damage in male Wistar rats

The purpose of this study was to determine the effects of the high consumption of sucrose on the levels of DNA damage in blood, hippocampus and bone marrow of rats. Male Wistar rats were treated for 4 months with sucrose (10% for 60 initial days and 34% for the following 60 days) in drinking water, and then, glycemia and glycated hemoglobin (A1C) were measured. Levels of DNA damage in blood and hippocampus were evaluated by the comet assay. The micronucleus test was used to evaluate chromosomal damages in the bone marrow. The sucrose treatment significantly increased (p<0.01) the serum glucose levels (~20%) and A1C (~60%). The level of primary DNA damage was significantly increased (p<0.05) in hippocampal cells (~60%) but not in peripheral blood leukocytes (p>0.05). Additionally, it was observed a significative increase (p<0.05) in the markers of chromosomal breaks/losses in bone marrow, as indicated by the micronucleus test. This is the first study that evaluated DNA damage induced by high sucrose concentration in the hippocampus and bone marrow of rats. Sucrose-induced DNA damage was observed in both tissues. However, the mechanism of sucrose toxicity on DNA remains unknown.

Influence of vitamin intake and MTHFR polymorphism on the levels of DNA damage in tobacco farmers

BACKGROUND

Genetic damage may occur spontaneously under normal metabolic circumstances, inadequate intake of nutrients, and excessive exposure to environmental mutagens.

OBJECTIVES

To evaluate the influence of the intake of micronutrients vitamin B12, vitamin B6, and folate and of the polymorphism methylenetetrahydrofolate reductase (MTHFR) C677T on the induction of DNA damage in tobacco farmers.

METHODS

The study involved 66 men and 44 women engaged in tobacco cultivation in the region of Venâncio Aires (Rio Grande do Sul state, Brazil). Peripheral blood samples were collected to analyze DNA damage using the Comet assay, the micronucleus (MN) test and MTHFR C677T polymorphism. Dietary intake was evaluated based on the mean values obtained from three 24-h diet recall questionnaires, and nutrient intake data were computerized and estimated in the Food Processor SQL 10.9 program. The statistical tests used to generate the stated results were Kruskal-Wallis test, Exact Fisher's test, and multivariate linear regression analysis.

RESULTS

DNA damage was significantly higher in individuals who had an inadequate intake of folate, vitamin B12, and vitamin B6 (P < 0.01) assessed by Comet assay. In relation to MN test results, buccal cells showed MN frequency higher in individuals with inadequate intake of vitamin B6 (P < 0.01). No difference was observed in MN lymphocytes frequency. No significant association was detected between MTHFR C677T polymorphism and DNA damage in tobacco farmers.

CONCLUSION

Our results suggest that folate, vitamin B12, and vitamin B6 deficiency may be associated with genotoxic effect in individuals exposed to pesticides.

Biotechnology in the wood industry

Wood is a natural, biodegradable and renewable raw material, used in construction and as a feedstock in the paper and wood product industries and in fuel production. Traditionally, biotechnology found little attention in the wood product industries, apart from in paper manufacture. Now, due to growing environmental concern and increasing scientific knowledge, legal restrictions to conventional processes have altered the situation. Biotechnological approaches in the area of wood protection aim at enhancing the treatability of wood with preservatives and replacing chemicals with biological control agents. The substitution of conventional chemical glues in the manufacturing of board materials is achieved through the application of fungal cultures and isolated fungal enzymes. Moreover, biotechnology plays an important role in the waste remediation of preservative-treated waste wood.

Surgical Treatment of Recurrent Carotid Artery Stenosis and Carotid Artery Stenosis after Neck Irradiation: Evaluation of Operative Risk

Surgical treatment of recurrent carotid artery stenosis after endarterectomy and carotid artery stenosis after neck irradiation purportedly has a higher complication rate than primary carotid endarterectomy (CEA). Accordingly, carotid angioplasty has been proposed as a safer alternative. The purpose of this study was to evaluate operative risks on the basis of our experience with these lesions. A series of 679 carotid revascularizations (CRV) performed over a period of 9 years was retrospectively reviewed. Immediate outcome and operative technique was analyzed in three groups: group 1 included 549 "routine" CRV, group 2 included 8 CRV for recurrent stenosis after CEA, and group 3 consisted of 11 CRV for stenosis after neck irradiation. No difference in revascularization techniques was found between groups 1 and 2. In contrast there were fewer CEA and resection-anastomosis procedures in group 2 than in group 1 (62.5% vs. 98.2%; p < 0.0006) and more bypass procedures (37.5% vs. 1.8%; p = 0.0015). The cumulative neurological morbidity/mortality rate (CMMR) was 0% in groups 2 and 3 as compared to 4.4% in group 1. In comparison with group 1, early and permanent neurological morbidity rates were significantly higher in both group 2 (2.2% vs. 25.0%; p = 0.015 and 0.2% vs. 12.5%; p = 0.028, respectively) and group 3 (2.2% vs. 18.2%; p = 0.028 and 0.2% vs. 9.1%; p = 0.039, respectively). Surgical treatment of recurrent stenosis after CEA and stenosis after neck irradiation is not associated with a higher CMMR. The only potentially valid justification for using percutaneous transluminal angioplasty in these patients would be a higher risk of cervical neurological morbidity.

Modification of lignin for the production of new compounded materials

The cell walls of woody plants are compounded materials made by in situ polymerization of a polyphenolic matrix (lignin) into a web of fibers (cellulose), a process that is catalysed by polyphenoloxidases (laccases) or peroxidases. The first attempt to transform the basic strategy of this natural process for use in human craftsmanship was the ancient lacquer method. The sap of the lacquer tree (Rhus verniciflua) contains large amounts of a phenol (urushiol), a polysaccharide and the enzyme laccase. This oil-in-water emulsion solidifies in the presence of oxygen. The Chinese began using this phenomenon for the production of highly creative artwork more than 6,000 years ago. It was the first example of an isolated enzyme being used as a catalyst to create an artificial plastic compound. In order to apply this process to the production of products on an industrial scale, an inexpensive phenol must be used, which is transferred by an enzyme to active radicals that react with different components to form a compounded material. At present, the following approaches have been studied: (1) In situ polymerization of lignin for the production of particle boards. Adhesive cure is based on the oxidative polymerization of lignin using phenoloxidases (laccase) as radical donors. This lignin-based bio-adhesive can be applied under conventional pressing conditions. The resulting particle boards meet German performance standards. By this process, 80% of the petrochemical binders in the wood-composite industry can be replaced by materials from renewable resources. (2) Enzymatic copolymerization of lignin and alkenes. In the presence of organic hydroperoxides, laccase catalyses the reaction between lignin and olefins. Detailed studies on the reaction between lignin and acrylate monomers showed that chemo-enzymatic copolymerization offers the possibility to produce defined lignin-acrylate copolymers. The system allows control of the molecular weights of the products in a way that has not been possible with chemical catalysts. This is a novel attempt to enzymatically induce grafting of polymeric side chains onto the lignin backbone, and it enables the utilization of lignin as part of new engineering materials. (3) Enzymatic activation of the middle-lamella lignin of wood fibers for the production of wood composites. The incubation of wood fibers with a phenol oxidizing enzyme results in oxidative activation of the lignin crust on the fiber surface. When such fibers are pressed together, boards are obtained which meet the German standards for medium-density fiber boards (MDF). The fibers are bound together in a way that comes close to that by which wood fibers are bound together in naturally grown wood. This process will, for the first time, yield wood composites that are produced solely from naturally grown products without any addition of resins.

The effect of ions on the enzymatically induced synthesis of lignin graft copolymers

The effect of different ions which are constituents of technical lignin sulfonates (LS) on chemo-enzymatic graft co-polymerization was determined. The application of the iron chelator desferrioxamine in the initial reaction mixture revealed that iron impurities of LS which catalyzed a Fenton-like reaction were crucial for the initiation of grafting, whereas calcium or chloride ions showed no such effect. The addition of laccase (ATCC 11235) to the reaction mixture which contained desferrioxamine caused a significantly higher yield compared to the control; this indicates a crucial effect of laccase with regard to the initiation of copolymerization. The involvement of laccase in the initiation of the graft copolymerization was additionally confirmed by the application of low molecular weight phenolics instead of LS. In the presence of the lignin-like substrates, 3,4-dihydroxybenzoic acid and guaiacol, the rate of the decomposition of t-butylhydroperoxide was significantly enhanced by laccase. It can be assumed that the enzymatically generated phenoxy radicals mediate the production of oxygen centered radicals (alkoxy or peroxy) which initiate grafting.

Chemo-enzymatically induced copolymerization of phenolics with acrylate compounds

Initiation of copolymerization of lignin-like phenolic and acrylic compounds by the phenoloxidase laccase (EC 1.10.3.2) and a peroxide species (t-butylhydroperoxide, t-BHP) was compared to a Fenton-like system (ferrous ion, t-BHP). Initially, the relative activity of laccase towards different phenolic compounds and the optimum pH of some characteristic phenolics were determined. The polymer yield and the average molecular weight (Mw) of chemo-enzymatically produced polymers were dependent both on the type of each phenolic tested and on the phenol/monomer ratio. Furthermore, the success of copolymerization of the phenolics was dependent both on their redox potential and on the type of acrylic monomer applied. The extent of phenol incorporation into the polymer chain was enhanced by the presence of laccase in the reaction mixture and was significantly higher than in polymerization initiated by a Fenton-like reaction.

Quantitative impact of pediatric sinus surgery on facial growth

OBJECTIVE/HYPOTHESIS

To quantitatively evaluate the long-term impact of sinus surgery on paranasal sinus development in the pediatric patient.

STUDY DESIGN

Longitudinal review of eight pediatric patients treated with unilateral sinus surgery for periorbital or orbital cellulitis with an average follow-up of 6.9 years. Control subjects consisted of two groups, 9 normal adult patients with no computed tomographic evidence of sinusitis and 10 adult patients with scans consistent with sinusitis and a history of sinus-related symptoms extending to childhood.

METHODS

Application of computed tomography (CT) volumetrics, a technique allowing for precise calculation of volumes using thinly cut CT images, to the study and control groups.

RESULTS

Paired Student t test analyses of side-to-side volume comparisons in the normal patients, patients with sinusitis, and patients who had surgery revealed no statistically significant differences. Comparisons between the orbital volumes of patients who did and did not have surgery revealed a statistically significant increase in orbital volume in patients who had surgery.

CONCLUSIONS

Only minimal changes in facial volume measurements have been found, confirming clinical impressions that sinus surgery in children is safe and without significant cosmetic sequelae.

Enhanced stability of laccase in the presence of phenolic compounds

The storage stability of laccase (EC 1.10.3.2) from the white-rot basidomycete Trametes versicolor in potassium-citrate buffer was enhanced by various phenolic compounds as well as by lignin sulfonate. The highest storage stability was obtained with phenolics, e.g. phloroglucin and 3,5-dihydroxybenzoic acid; these represent substrates of laccase which are oxidized slowly because of their relatively high redox potential and which did not precipitate from the solution within the tested period of time. Sterilization enhanced the stability of laccase but additional stabilization by phenolics was observed both under sterile and non-sterile conditions. We thus concluded that stabilization occurred not only through prevention of microbial degradation.

Chemoenzymatical grafting of acrylamide onto lignin

Laccase (E.C.1.10.3.2.) from white-rot basidiomycete Trametes versicolor and dioxane peroxides were essential in the copolymerization of acrylamide and a derivative with lignin in a dioxane-H(2)O (7:3) mixture. Both a solubility test and an elemental analysis of the eluted and separated fractions provided evidence of grafting. Gel permeation chromatography on Sephadex G-100 showed that the side chain and the lignin backbone migrate as one unit through the column. Copolymers obtained were characterized by UV-VIS-spectroscopy as well as FT-IR, and 13C-CPMAS-NMR spectroscopy. Freeze-dried copolymers of lignin and acrylamide appeared as homogeneous fibril-like particulate. The mechanism of the enzymatical grafting is discussed.

Phototherapeutic keratectomy combined with photorefractive keratectomy for treatment of myopia with corneal scars

To evaluate the effect of phototherapeutic keratectomy combined with photorefractive keratectomy in the treatment of myopia with corneal scars, corneal epithelium was removed with laser plus scraping. Corneal scars were removed with PTK, followed by PRK for myopia. Healon was used to make corneal surface smoother during operation. 30 eyes of 24 cases of myopia with corneal scars were followed up for one year. Mean corrected vision was 0.51 and myopic degree was -6.42 D +/- 4.26 D before operation. After operation, corneal scars of 21 eyes (70.0%) were removed in operative zone. The vision of 27 operated eyes (90.0%) was equal to or better than best corrected vision. Mean postoperative visual acuity was 0.72. Corneal surface was smoother and astigmatism was reduced after the surgery. Our study showed that PTK combined with PRK is a safe and effective treatment for myopia with corneal scars.

Selectivity of ferric enterobactin binding and cooperativity of transport in gram-negative bacteria

The ligand-gated outer membrane porin FepA serves Escherichia coli as the receptor for the siderophore ferric enterobactin. We characterized the ability of seven analogs of enterobactin to supply iron via FepA by quantitatively measuring the binding and transport of their 59Fe complexes. The experiments refuted the idea that chirality of the iron complex affects its recognition by FepA and demonstrated the necessity of an unsubstituted catecholate coordination center for binding to the outer membrane protein. Among the compounds we tested, only ferric enantioenterobactin, the synthetic, left-handed isomer of natural enterobactin, and ferric TRENCAM, which substitutes a tertiary amine for the macrocyclic lactone ring of ferric enterobactin but maintains an unsubstituted catecholate iron complex, were recognized by FepA (Kd approximately 20 nM). Ferric complexes of other analogs (TRENCAM-3,2-HOPO; TREN-Me-3,2-HOPO; MeMEEtTAM; MeME-Me-3,2-HOPO; K3MECAMS; agrobactin A) with alterations to the chelating groups and different net charge on the iron center neither adsorbed to nor transported through FepA. We also compared the binding and uptake of ferric enterobactin by homologs of FepA from Bordetella bronchisepticus, Pseudomonas aeruginosa, and Salmonella typhimurium in the native organisms and as plasmid-mediated clones expressed in E. coli. All the transport proteins bound ferric enterobactin with high affinity (Kd </= 100 nM) and transported it at comparable rates (>/=50 pmol/min/10(9) cells) in their own particular membrane environments. However, the FepA and IroN proteins of S. typhimurium failed to efficiently function in E. coli. For E. coli, S. typhimurium, and P. aeruginosa, the rate of ferric enterobactin uptake was a sigmoidal function of its concentration, indicating a cooperative transport reaction involving multiple interacting binding sites on FepA.

An analysis of 1,001 blinding patients with corneal disease in 1960-1989

PURPOSE

To investigate the condition and change of corneal blindness (CB) in the past 30 years.

METHODS

1,001 blinding patients of corneal disease were clinically analysed from 1960 to 1989, including etiology, sex, age, occupation, difference between the urban and rural areas etc.

RESULTS

The male predominated. Infection stood the first cause of blinding corneal diseases, followed by trauma, malnutrition and the others. HSV-1 keratitis was the most frequent infection in 1980s. The highest incidence of CB was 20-40 year-old. The number of CB caused by occupational trauma was more than that by ordinary trauma in 1960s, but from 1970s, the latter was more than the former. The number of CB in rural area was more than that in the urban in 1960s, but from 1970s, there was no significant difference between the two areas. The percentage of bilateral CB was gradually decreased.

CONCLUSION

We should try to find more effective strategies to prevent and treat CB caused by HSV-1 keratitis, pay special attention to preschool blindness caused by perforation injuries and avoid infection after corneal injuries of foreign bodies.

[Surgical therapy of esophageal perforation. A determination of current status based on 4 personal cases and the literature]

We present four cases of esophageal rupture (three iatrogenic, one Boerhaave syndrome) to demonstrate the difficulty in diagnosis and therapy. The current literature is discussed and conclusions are drawn as regards the modus operandi. All our patients were operated on. The site of esophageal rupture was always closed with a primary suture and substantial irrigation and drainage were performed. In two cases the suture line was in addition covered with fibrin glue or by an omentum flap, respectively. All patients survived and recovered was unremarkable. Our own results and a subsequent analysis of literature allow the following conclusions. At an early stage of esophageal rupture surgical intervention is indicated. The method of choice is primary closure of the rupture site by suture, possibly combined with a muscle or omentum flap. In cases of delayed diagnosis with advanced mediastinitis, suture of the rupture site should also be striven for. Additional coverage is advisable in these cases. Resection procedures with or without reconstruction should be done only in exceptional cases before of the high surgical risk.

[A study on histochemistry and electron microscopy of corneal nerves in experimental diabetic rabbits]

OBJECTIVE

To observe the changes of corneal nerves in diabetes mellitus.

METHODS

Alloxan-induced diabetes in rabbits was used as the experimental model. Histochemical techniques and electron microscopy were applied to examine the corneal nerves.

RESULTS

In the diabetic rabbits, from 6 weeks, the density of nerve plexus became markedly sparser, the fibers thinner and the activity of nerves lower than those of the control group. Ultrastructural changes showed swelling of axons, irregular distribution of fibril and degeneration of mitochondria of varying degree; with the progress of disease the above changes became more marked gradually.

CONCLUSION

The abnormal corneal nerve changes might be a pathologic basis for the reduction in corneal sensitivity in diabetes.

[A study on the course of corneal epithelial healing in diabetic rabbits]

OBJECTIVE

In order to approach the course of corneal epithelial healing of diabetes mellitus.

METHODS

The experimental rabbit diabetes models were produced by the injection of alloxan. The corneal epithelium of each rabbit was removed by freezing with a 6 mm diameter brass probe cooled in liquid nitrogen. The rate of corneal epithelial healing following freezing in the normal rabbit was compared to that in the diabetic one. Contrasted with the normal rabbits, the ultrastructural changes of the epithelium with and without freezing were also observed in the diabetic rabbits.

RESULTS

It is shown that there is no statistical significant difference in the overall rate of epithelial healing between the normal and diabetic rabbit. In contrast with the normal rabbit, the epithelial basement membrane of the diabetic rabbit without freezing revealed markedly thickened, and the mitochondria and glycogen particles in the epithelial cell increased. In the diabetic rabbit with freezing, the epithelial basement membrane appeared absent or discontinuous. After complete healing, the corneal epithelium was edematous in diabetic rabbit.

CONCLUSION

The abnormal basemenet membrane and edematous epithelial cell were responsible for the diabetic corneal epithelial poor healing and recurrent erosion.

Intraoperative use of mitomycin in trabeculectomy

Mitomycin (0.2 mg/ml) was applied intraoperatively to 26 glaucomatous patients (33 eyes) during conventional trabeculectomy procedure. Most of them were considered to be at high risk of surgical failure. The conjunctival flap was fornix-based in 9 patients (11 eyes). The success rate was 84.8% without any serious side effect.

Increased carbon dioxide production in two patients with malignant hyperpyrexia and its control by dantolene

Two patients with successfully treated malignant hyperpyrexia are reported. Carbon dioxide output, calculated from the respiratory minute volume and PaCO2, was found to be greatly increased in both patients. In the patient who received dantolene 7.5 mg kg-1 the carbon dioxide output decreased rapidly to normal values, whereas in the other patient carbon dioxide output remained increased for several hours.