315 research outputs found

    Microvascular autologous submandibular gland transplantation in severe cases of keratoconjunctivitis sicca

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    Dry eye syndrome is a relatively common disease of the tears and ocular surfaces that results in discomfort, visual disturbance, and tear film instability with possible damage to the ocular surfaces. Microvascular submandibular gland (SMG) transfer offers a surgical alternative for a permanent autologous substitution of tears using the basal secretion of a transplanted SMG. Long-term follow-up reveals that this technique is a lasting and effective solution for patients with severe dry eye syndrome. The uncomfortable symptoms were relieved, and the frequency of use of pharmaceutical tear substitutes was reduced. Objective examination showed significant improvement in tear film and some features of ocular surface such as breakup time of tear film and corneal staining. Patients may suffer from obstruction of Wharton's duct or epiphora after surgery. Activation of secretion-related receptors could improve the early hypofunction of the denervated SMG and prevent the duct obstruction. Reduction surgery, partial SMG transplantation, uses of atropine gel or Botulinum toxin A could be the choices of treatment for epiphora.PubMed0153

    Toxicological evaluation of precocene II isolated from Ageratum conyzoides L. (Asteraceae) in Sprague Dawley rats

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    Precocene II (6,7-dimethoxy-2,2-dimethyl-2-chromene) was the main constituent isolated from Ageratum conyzoides L. and reportedly possessed antifungal activity. The study investigated the isolation, purification and toxicological effects of precocene II from A. conyzoides in Sprague Dawley rats. Precocene II was isolated from the petroleum ether fraction of the plant and the structure was determined by 1H-,13C-,DEPT-NMR and MS spectral techniques. Three groups of eight rats per group were used for the study. While groups B and C were respectively administered with 25 and 50 mg/kg of precocene II in 0.25% CMC-Na for 11 days by gastric intubation, group A was administered with 0.25% CMC-Na and served as the control group. After the last treatment, animals were fasted overnight and on the 12th day, they were injected intravenously with 0.2 ml/kg body weight of phenobarbital. Animals were subsequently dissected from the abdominal region; blood was collected from the pulmonary vein into EDTA anti-coagulated and non anti-coagulated tubes. The liver, kidney and spleen tissues were extracted into separate bottles for histopathological examinations. Results from hematological study indicated that the white blood cell (WBC), red blood cell (RBC), plateletcrit (PCT) and mean corpuscular hemoglobin count (MCHC) were significantly higher across the treated groups. Biochemical result showed that serum glucose level was significantly reduced in the treated groups. No apparent damage was noticed in the liver, kidney and spleen tissues. The result therefore suggests that precocene II possesses hypoglycemic property and could alter some hematopoietic elements but was not toxic to the liver, kidney and spleen tissues

    Benzyl 2-ethyl­hexyl sulfoxide

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    The mol­ecule of the title compound, C15H24OS, shows S conformations for the S atom and the asymmetric C atom of the isooctyl group. The long axes of the mol­ecules are directed along the c axis. In the crystal structure, the mol­ecules are linked by weak inter­molecular bifurcated C—H⋯O hydrogen bonds

    A new norlignan from Taxodium ascendens

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    A new norlignan, (2R,3R,4S,5S)-2,4-bis(4-hydroxyphenyl)-3,5-dihydroxy-tetrahydropyran (1), together with 9 known compounds were isolated from the branches and leaves of Taxodium ascendens. Their structures were mainly determined on the basis of MS, IR, 1D and 2D NMR spectral evidences. Methanol extract showed inhibitory activity on carbonic anhydrase II with an IC50 value of 4.27 μg/ml, acetone extract and methanol extract inhibited activity of cathepsin B with IC50 values of 2.12 and 3.71 μg/ml, respectively.

    Reducing the aerodynamic drag of high-speed trains by air blowing from the nose part: Effect of blowing speed

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    To reduce the aerodynamic drag of high-speed trains, this work proposes an air blowing configuration on the head and tail cars of high-speed trains. The variation in the aerodynamic drag and slipstream velocity is analyzed under different blowing velocities, and the flow mechanism for train aerodynamic performance alteration is explained. The results show that under the blowing speeds of Ub = 0.05Ut, 0.10Ut, 0.15Ut, and 0.20Ut, where Ut is the train speed, the total drag coefficient (Cd) decreases by 5.81%, 10.78%, 13.70%, and 15.43% compared to the without-blowing case, respectively. However, with the increase in the blowing speed, the reduction trend of Cd tends to be smoother; namely, the decrement ratio compared to the previous blowing speed for the head car is 9.08%, 0.11%, 0.60%, and 1.14% for Ub = 0.05Ut, 0.10Ut, 0.15Ut, and 0.20Ut, respectively. The blowing measure generates an air gap between the coming flow and train surface, consequently causing a reduction in the viscous and pressure drag. In addition, the structure size and strength of the wake flow under different blowing cases show a decreasing trend from Ub = 0.00Ut to 0.10Ut and then an increasing trend from Ub = 0.10Ut to 0.20Ut. Thus, considering the blowing cost, efficiency, and flow structure evolution comprehensively, the case of Ub = 0.10Ut is recommended. Under this blowing speed, the reduction ratio of the aerodynamic drag is 9.18%, 12.77%, 10.90%, and 10.78% for the head, middle, tail car, and total train, respectively

    Biochemical, haematological and histopathological studies of extract of Ageratum conyzoides L. in Sprague Dawley rats

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    This study was conducted to evaluate the safety potential of the leaf extract of Ageratum conyzoides Linnaeus in Sprague Dawley (SD) rats using biochemical, haematological and histological indices of toxicity. Four groups of seven male SD rats per group were used for the study. To group A was administered 0.25% CMC-Na/ kg body weight and was used as the control group, while groups B, C and D were respectively administered with 500, 1000 and 1500 mg/kg body weight of the ethanolic leaf extract of A. conyzoides by gastric intubation for 14 days. Animals were subsequently anaesthetized, blood samples were collected for biochemical and haematological assays; organs were isolated and weighed, while the liver, kidney and spleen were processed for histopathological studies. Aspartate amino transferase, lactate dehydrogenase, creatine kinase and alkaline phosphatase were significantly (p < 0.05) reduced in the groups treated with 1000 and 1500 mg/kg body weight of the extract. Furthermore, there was a significant (p < 0.05) elevation in white blood cell count, mean platelet volume and % platelet distribution width. Histopathological studies indicated various degrees of hepatocellular necrosis in all the treated groups accompanied by significant increases in the weight of liver and spleen. The results showed that the ethanolic leaf extract of A. conyzoides significantly alters the biomarkers of cardiac and skeletal muscle disorders, and higher doses could induce liver cell injury

    Cell surface sialylation and fucosylation are regulated by the cell recognition molecule L1 via PLCγ and cooperate to modulate embryonic stem cell survival and proliferation

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    AbstractCell surface glycosylation patterns are markers of cell type and status. However, the mechanisms regulating surface glycosylation patterns remain unknown. Using a panel of carbohydrate markers, we have shown that cell surface sialylation and fucosylation are upregulated in L1-transfected embryonic stem cells (L1-ESCs). Consistently, the mRNA levels of sialyltransferase ST6Gal1 and ST3Gal4, and fucosyltransferase FUT9 were significantly increased in L1-transfected ESCs. Activation of L1 signaling promoted cell survival and inhibited cell proliferation. ShRNAs knocking down FUT9, ST6Gal1 and ST3Gal4 blocked these effects. A phospholipase Cγ (PLCγ) inhibitor and shRNA reduced ST6Gal1, ST3Gal4 and FUT9 mRNA levels in the L1-ESCs. Thus, embryonic stem cell surface sialylation and fucosylation are regulated via PLCγ by L1, with which they cooperate to modulate cell survival and proliferation

    Extramedullary versus intramedullary tibial alignment technique in total knee arthroplasty: A meta-analysis of randomized controlled trials

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    The aim of this study was to establish whether the use of an extramedullary or intramedullary tibial cutting guide leads to superior mechanical leg axis and implant positioning. A meta-analysis of six randomized controlled trials including 350 knees was performed. For the mechanical axis, frontal tibial component angle and tibial slope, there were no significant differences in the mean values or the number of outliers (±3°) between the extramedullary and intramedullary groups. A reduced tourniquet time was associated with the intramedullary guide. No significant difference in the complication rate was noted between the two groups. Neither extramedullary nor intramedullary tibial alignment was more accurate in facilitating the tibial cut. Use of an intramedullary guide results in a shorter tourniquet time and exhibits a similar complication rate as the extramedullary guide
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