Chitin is one of the most important component in fungal cell wall.Biosynthesis of chitin is a complex processes and needs several chitin synthase isoenzymes.The knowledge of structure,function and regulation of chitin synthases is mainly derived from the study of Saccharomyces cerevisiae.In contrast with the 3 chitin synthases in S.cerevisiae,7 were found in most filamentous fungi.In this review the classification and function of chitin synthases are summerized,and progress in the studies on chitin synthases of filamentous fungi which are of theoretical or medical or agricultural importance,including Aspergillus nidulans,Aspergillus fumigatus and Ustilago maydis are emphasized.Recent ad-vance of research on chitin synthase as antifungal target is also discussed.

Objective To evaluate the effect of endoscopic ultrasonography(EUS)in diagnosing e- sophageal and gastric varices in portal hypertension(PHT)patients.Methods Fifty-three patients with e- sophageal and gastric varices(EV、GV)of decompensation PHT and 20 patients without PHT as control were undergone EUS and esophagogastroduodenoscopy(EGD)simultaneously.EUS detected mainly the EGV,e- sophagus and stomach collateral veins.Results EUS identified EV endoscopically in 29(54.7%)patients. EUS detected GV in 24(45.3%)patients,compared with detection in 18(34.0%)patients by esopha- gogastroduodenoscopy(EGD)(P＜0.001).EUS detected PEV in 27(51%)patients.Distribution rates of PEV in F1,F2 and F3 are 0%,28.6% and 75% respectively.The comparison between groups shows sig- nificant difference(P＜0.001).Splenic vein can be seen in both control and experimental groups with di- ameter 7.5?1.35mm VS 11.5?3.5mm respectively,the difference between two groups is significant(P＜0.001).Proximal diameters of Azygos vein in two groups is 7.36?1.29mm VS 8.77?2.94mm respective- ly.Significant difference can be found(P＜0.05).Conclusion EUS had significant value in the diagnosis of PHT with EV and GV,and especially in detecting abnormalities of extra-luminal veins.

Anemia, Hemolytic, Autoimmune ; etiology ; Female ; Humans ; Infant, Newborn ; Male ; Pregnancy ; Pregnancy Complications ; Sjogren's Syndrome ; complications

Child, Preschool ; Cysts ; Diagnostic Errors ; Humans ; Leiomyoma ; diagnosis ; Male ; Nose Neoplasms ; diagnosis ; Vestibular Diseases

Withanolide A is a biologically active secondary metabolite occuring in roots and leaves of Withania somnifera. In the present study, adventitious roots from leaf explants of W. somnifera were induced for the production of withanolide-A by Agrobacterium tumefaciens strain C58C1 to obtain hair roots. Hair roots induction rate reached 30%. The withanolide A was determined by HPLC in different hair roots lines and different parts of W. somnifera. The average content of withanolide A in all hair roots lines were 1.96 times as high as that in wild-plant, the concentration of withanolide A in hair roots (1.783 mg x g(-1) dry weight) were 1.51 times as high as the roots of wild W. somnifera (1.180 mg x g(-1) dry weight), respectively. It is possible to obtain withanolide A from hair roots culture of W. somnifera.
Agrobacterium tumefaciens ; physiology ; Plant Extracts ; analysis ; biosynthesis ; Plant Roots ; chemistry ; growth & development ; metabolism ; microbiology ; Withania ; chemistry ; growth & development ; metabolism ; microbiology ; Withanolides ; analysis ; metabolism

Mean hemoglobin (Hb) concentration of about 3 500 subjects derived from 17 studies of Himalayan highlanders (Tibetans, Sherpas, and Ladakhis) was compared with lowlanders (Chinese Han, Indian Tamils) lived in the Himalayas, and European climbers during Everest expeditions as well as Andean natives. The results found that Hb concentration in Himalayan highlanders was systemically lower than those reported for Andean natives and lowland immigrants. These comparative data demonstrated that a healthy native population may successfully reside at high altitude without a significant elevation in Hb, and the lower Hb levels of Himalayan highlanders than those of migrated lowlanders and Andean natives are an example of favourable adaptation over the generations. In addition, excessive polycythemia has frequently been used as a marker of chronic mountain sickness (CMS). Altitude populations who have a higher Hb concentration also have a higher incidence of CMS. The low Hb in Himalayans suggested as showing adaptation over many generations in Tibetan stock. Recent work in Tibet, suggested that Tibetans there may have adapted to high altitude as a result of evolutionary pressure selecting for genes which give an advantage at altitude. All of the population genomic and statistical analysis indicated that EPAS1 and EGLN1 are mostly likely responsible for high altitude adaptation and closely related to low Hb concentration in Tibetans. These data supported the hypothesis that Himalayan highlanders have evolved a genetically different erythropoietic response to chronic hypoxia by virtue of their much longer exposure to high altitude.
Adaptation, Physiological ; Altitude ; Asian Continental Ancestry Group ; genetics ; Basic Helix-Loop-Helix Transcription Factors ; genetics ; Evolution, Molecular ; Hemoglobins ; genetics ; Humans ; Hypoxia-Inducible Factor-Proline Dioxygenases ; genetics ; Tibet

Objective To investigate the utility of bedside electromyography (EMG) in diagnosis and management of critical illness patients with suspected neuromuscular diseases.Methods Bedside EMG was performed in 34 critical illness patients with weakness and respiratory involvement,including segmental motor nerve conduction studies,sensory nerve conduction studies,F waves,concentric needle EMG and repetitive nerve stimulation.The clinical manifestations and clinical utility of bedside EMG in critical illness patients with suspected neuromuscular diseases were analyzed. Results EMG was normal in 5 patients.Low-frequency repetitive nerve stimulation showed decrement response of compound muscle action potential (CMAP) in 4 of 8 patients.Motor nerve conduction studies showed CMAP amplitude decreased in 73.3％(22/30) patients,and demyelinating changes was detected in 20.0％ (6/30)patients.F-wave persistence was 0 in 55.0％ (11/20) patients.Amplitude of sensory nerve action potential decreased in 28.6％ (6/21)patients.Bedside EMG could help to confirm or exclude diagnoses and guide the management in 82.4％(28/34) patients,confirm the diagnoses of peripheral neuropathy but have no effect on management in 11.8％ (4/34) patients,and bedside EMG was inconclusive in 2 patients.Conclusions Bedside EMG is useful for the diagnosis and management of critical ill with suspected neuromuscular diseases,while motor nerve conduction studies and repetitive nerve stimulation are more valuable.Individualized protocol for EMG studies should be made on the basis of clinical problem.

Objective To observe the MR findings of myxoid-round cell liposarcoma of the lower extremities and to evaluate therelationship between MR findings and pathologic features. Methods MR findings of 6 myxoid-round cell liposarcomas of the lowerextremities confirmed pathologically were retrospectively reviewed,including tumor's location,size,morphology,internal architecture and signal intensity characteristics on T_1WI,T_2WI and SPIR T_2WI and the pattern of enhancement.Results All tumors were located in thedeep space among skeletal muscles of the lower extremities,with unregular shape,sharp borber and thick septal structures.Tumors werehomogeneous or heterogeneous isointense on T_1WI and hyperintense on T_2WI relative to the signal intensity of skeletal muscles and heterogeneous enhancement after the injection of GdDTPA.Conclusion MRI may lead to a correct diagnosis of myxoidround cell liposarcoma of the lower extremities.

Objective To study the changes of serum interleukin(IL)-4,IL-12 and correlation with cellular immunity in children with asthma of different stages.Methods Fifty asthmatic children were randomly selected, including 30 cases in attack stage (group A) and 20 cases in remission stage (group R). At the same time, 22 healthy children were studied as normal controls (group N).The levels of IL-12 and IL-4 ,T cells subgroups and erythrocyte immunity were detected.Results 1.Serum IL-12 levels were (24.44? 13.26 ),(42.30?12.65),(44.68?28.28) ng/L in group A, R and N,respectively. There was significant difference in three groups (F=8.92 P

Objective To compare the efficacy of a modified percutaneous transhepatic variceal embolization (PTVE) with 2-Octyl-Cyanoacrylate (2-OCA) and endoscopic variceal obturation (EVO) in preventing gastric variceal bleeding.Methods Seventy-seven patients with history of gastric variceal bleeding who underwent either EVO or PTVE were retrospectively reviewed.The rebleeding rate,survival rate and complications were compared between the two groups.Results EVO was performed in 45 patients; PTVE was performed in 32 patients.During the follow-up (19.78 ± 7.70 months in EVO group,vs.21.53 ± 8.56 months in PTVE group),rebleeding occurred in 17 patients (37.78％) of EVO group,and in 4 patients (12.5％) of PTVE group (P =0.028).The cumulative rebleeding free rate for EVO was 75％,59％,and 49％ in 1,2,and 3 years,respectively; 93％,84％,84％ for PTVE (P =0.011).There is no significant different in survival rate and the incidence of complications was similar in two groups.Conclusion Compared with EVO,PTVE with 2-OCA demonstrates advantage as an effective and safe method for gastric varices.