[Prediction of Cellulose, Hemicellulose, Lignin and Ash Content of Four Miscanthus Bio-Energy Crops Using Near-Infrared Spectroscopy].

Biomass energy is being industrialized rapidly in China in recent years, whereas, research on energy grass is still in primary stage. Only if near-infrared spectroscopy mode was constructed which was used to predict the lignin, cellulose and hemicellulose contents in energy crop, the varieties screening, performance evaluation and on-line control of industrialization would be facilitated. In this study, the prediction model for quality indices (cellulose, hemicellulose, lignin and ash) of four energy grass (Miscanthus) was built using Fourier transform near-infrared (FT-NIR) spectroscopy combined with partial least squares regression (PLSR), and the impacts exerted by particle size on the model were also revealed. The results showed that (1) the root mean error of cross validation (RMSECV) of cellulose, hemicelluloses and lignin contents were 1.35% (R = 0.88), 0.39% (R = 0.91) and 0.35 (R2 = 0.80), respectively in stalk and 0.72% (R = 0.88), 0.85% (R2 = 0.85) and 0.44 (R2 = 0.87), respectively in leaf. The model showed good performance in prediction of corresponding contents in unknown samples, however, no satisfying performance in ash content. (2) Both 2 mm and 0.5 mm grades of particle size can meet accuracy requirements of the model. But considering the time and labor cost, 2 mm grade was suggested for model building.

[Clinical analysis of 6 cases of Bartter syndrome].

OBJECTIVE: To summarize the clinical characteristics of Bartter syndrome and investigate its pathogenesis. METHODS: The clinical data of 6 cases of Bartter syndrome at our hospital from November 2006 to May 2010 were analyzed retrospectively. RESULTS: The onset age of Bartter syndrome was 13-35 years old. The main symptoms included weakness (6/6), paralysis (1/6), numbness (5/6) and tetany (4/6). All patients had normal blood pressure. The biochemical tests showed persistent hypokalemia, metabolic alkalosis (6/6) and hyperreninemia. The pathological examination of deltoid muscle biopsy showed the swelling, degeneration and necrosis of myocytes and the deposition of immunocomplex in myolemma. And the pathological examination of renal biopsy showed the hyperplasia of juxtaglomerular apparatus (5/6) and the deposition of immunocomplex. All symptoms were relieved after a therapy of potassium supplementation or a combination of indomethacin, spironolactone and immunosuppressant. CONCLUSION: When such clinical features as weakness, paralysis, tetany, hypokalemic alkalosis and normotension are encountered, Bartter syndrome should be suspected. Serum electrolytes, blood gas analysis and activation of the renin-angiotensin-aldosterone system should be examined for a definite diagnosis. The treatment of choice includes potassium and magnesium supplementation or in combination with prostaglandin synthetase inhibitor, aldosterone antagonist and immunosuppressant. Immunologic mechanism may participate in the course of Bartter syndrome.

[A novel mutation in the myocilin gene identified in a Chinese primary open angle glaucoma family].

OBJECTIVE: To determine the possible myocilin molecular genetic defect underlying POAG in China and to identify the pathogenic mutation causing the disease. METHODS: The majority of 1 branch of a large Chinese POAG family were personally examined by two senior ophthalmologists. The diagnoses were made by both doctors according to the signs of elevated intraocular pressure, glaucomatous optic neuropathy and glaucomatous visual field defect. All coding sequences of the myocilin gene plus the flanking sites were amplified by polymerase chain reaction (PCR) using genomic DNA from all examined family members followed by sequencing of the PCR products. One hundred normal control subjects were screened by single strand confirmational polymorphism analysis for the mutation. RESULTS: This Chinese pedigree exhibited autosomal dominant mode of inheritance. The onset age ranged from 26 to 59 years. A novel disease-causing missense mutation T455K in the third exon of the myocilin gene was identified in all affected family members, all glaucoma suspects and 4 individuals who have not shown apparently signs of glaucoma. None of the subjects without the mutation had glaucoma. Affected individuals with the T455K mutation showed variable onset between 26 and 59 years of age. Filtering surgery was performed on all of 7 affected family members. The T455K mutation in myocilin gene was not found in the normal controls. A previously reported polymorphism IVS2+35(A to G)was detected in 4 individuals. CONCLUSION: The novel myocilin sequence alteration T455K that is highly associated with the development of glaucoma and locates in a very conserved residue is proven to be a disease-causing missence mutation. All affected individuals and all POAG suspects in this family are identified to have this mutation. The mutation in this family is associated with a phenotype characterized by mix-onset open angle glaucoma and associated with a high penetrance. It is important for the mutation screening and periodical checkups of presymptomatic individuals belonging to the family of a POAG patient with T455K mutation.