ObjectiveTo survey the clinical epidemiology and correlations between pathology and clinical features of major groups of kidney diseases in a rural area of China.MethodsFrom January 1996 to December 2010, histologic diagnosis of renal disease was made on samples collected from 919 patients from a single center in the midland rural area of China. Demographic data were obtained from all patients, and clinical profiles were analyzed in 917 patients.ResultsThe mean age of the whole group was 33.13 (14.13) years (range 16–72 years). Men accounted for 55.28% (n = 508) and women made up 45.72% (n = 408). Patients aged 16 to 50 years comprised 83.75% of the sample (n = 770). Lupus nephritis was the predominant diagnosis in women; renal diseases were predominant in men. In patients with nephrotic syndrome, mesangial proliferative glomerulonephritis was the most frequent pathologic pattern (39.46%), followed by IgA nephropathy (18.39%), whereas in patients with nephritic syndrome, IgA nephropathy (39.64%) was the most frequent pathologic pattern, followed by mesangial proliferative glomerulonephritis (32.38%). The most common pathologic pattern in patients with secondary glomerulonephritis was Henoch-Schoˇnlein purpura nephritis, followed by lupus nephritis.ConclusionsMesangial proliferative glomerulonephritis was the most common renal pathologic pattern. Male adolescents were predominant in this group of patients. The most common clinical syndrome was nephrotic syndrome.

A new xylanase gene (xyn43A) from Aspergillus niger XZ-3S was cloned and expressed in Escherichia coli BL21-CodonPlus (DE3)-RIL. The coding region of the gene was separated by only one intron 86 bp in length. It encoded 318 amino acid residues of a protein with a calculated molecular weight (MW) of 33.47 kDa plus a signal peptide of 19 amino acids. The amino acid sequence of the xyn43A gene showed 77.56% amino acid identity to A. nidulans xylanase, and the phylogenetic tree analysis revealed that xyn43A had close relationships with those of family 43 of glycosyl hydrolases reported from other microorganisms. Three-dimensional structure modeling showed that Xyn43A had a typical five-blade β-propeller fold. The mature peptide encoding cDNA was subcloned into pET-28a (+) expression vector. The resultant recombinant plasmid pET-28a-xyn43A was transformed into Escherichia coli BL21-CodonPlus (DE3)-RIL, and xylanase activity was measured. A maximum activity of 61.43 U/mg was obtained from the cellular extract of E. coli BL21-CodonPlus (DE3)-RIL harboring pET-28a-xyn43A. The recombinant xylanase had optimal activity at pH5.0 and 45 C. Fe 3+ , Cu 2+ and EDTA had an obvious active effect on the enzyme.