Isoniazid (INH) is highly effective for the management of tuberculosis. However, it can cause liver injury and even liver failure. INH metabolism has been thought to be associated with INH-induced liver injury. This review summarized the metabolic pathways of INH and discussed their associations with INH-induced liver injury.

Humans ; Reconstructive Surgical Procedures ; Trachea ; surgery

In order to characterize a thermostable urate oxidase (Uox) from Microbacterium sp. strain ZZJ4-1, we cloned its gene (uox). The open reading frame of uox contained 894 base pairs and encoded a protein with 297 amino acids. Alignment of gene sequences indicated there was no obvious identity with the most reported uox and that 72% identity was found with uox from Arthrobacter globiformis. We inserted the gene into the plasmid pET-15b to construct an expression vector pET-15b-uox and got it induced expression in Escherichia coli BL21 (DE3). After the purification of the recombinant Uox by the HisBind column, we studied some properties of it. It was composed of subunits with a molecular mass of about 35 kDa. The optimal temperature and pH was 30 degrees C and pH 7.5. It was stable below 65 degrees C and from pH 8.5 to 11.0. The Km value was 0.22 mmol/L with the uric acid as the substrate. Ag+, Zn2+, CU2+ and SDS could totally inhibit its activity while Tween 20, Tween 80 and Triton X-100 had a slight promotion effect. The thermal stability of this enzyme was the most excellent among the reported recombinant Uox. Based on this property, it would be very useful in the application.
Actinomycetales ; enzymology ; genetics ; Amino Acid Sequence ; Cloning, Molecular ; Enzyme Stability ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Molecular Sequence Data ; Recombinant Proteins ; biosynthesis ; genetics ; Urate Oxidase ; genetics ; metabolism

We purified a sarcosine oxidase from Bacillus sp. strain BSD-8 isolated from soil. We purified the enzyme by ammonium sulfate precipitation, DEAE-cellulose, Toyopearl hydrophobic and Sephadex G-75 molecular sieve chromatography and characterized the purified sarcosine oxidase. This sarcosine oxidase was a flavin enzyme containing a noncovalently bound flavin with the subunit molecular mass of 51 kDa. The optimal temperature for this enzyme was 60 degrees C and it showed its highest activity at pH 8.5. It was stable in the pH range of 8.0-10.0 and at the temperature of 60 degrees C. Estimated by Lineveaver-Burk plots, the K(m) of the enzyme was 3.1 mmol/L. Ag+, Hg2+, SDS and Tween 80 dramatically inhibted the enzyme activity, whereas Tween 20 and Triton X-100 had no effect on enzyme activity. The thermostability of this enzyme was better than reported sarcosine oxidases, and it could be applied in enzymatic measuring of creatinine.
Bacillus ; enzymology ; isolation & purification ; Bacterial Proteins ; chemistry ; isolation & purification ; metabolism ; Chemical Precipitation ; Enzyme Stability ; Sarcosine Oxidase ; chemistry ; isolation & purification ; metabolism ; Soil Microbiology

Neurocytoma, a rare brain tumor, is characterized by a mass located mainly in cerebral ventricles. It is prone to be misdiagnosed as oligodendroglioma or ependymoma due to their similar histopathological features in clinical practice. This study aimed to examine the clinicopathological features and differential diagnosis of central and extraventricular neurocytoma. The clinical and histopathological data of 17 patients (male: female=7:10; age: 4-41 years; mean age: 27.4 years) with central or extraventricular neurocytoma were retrospectively analyzed. These patients showed typical radiological, histopathological and immunohistochemical features of neurocytoma. The tumor tissue was found to be composed of small uniform cells with round nuclei and clear cytoplasm resembling that of oligodendroglioma and ependymoma. Immunohistochemistry revealed the tumor tissues were positive for neuronal markers such as synaptophysin (SYN) and neuronal nuclear antigen (NeuN). It was concluded histopathological features of neurocytoma overlaps with some tumors in the central neural system. Immunopositivity for SYN and NeuN can help differentially diagnose neurocytoma.
Adolescent ; Adult ; Antigens, Nuclear ; metabolism ; Biomarkers, Tumor ; metabolism ; Brain Neoplasms ; pathology ; Brain Stem ; pathology ; Cerebral Ventricle Neoplasms ; pathology ; Child ; Child, Preschool ; Female ; Humans ; Male ; Nerve Tissue Proteins ; metabolism ; Neurocytoma ; pathology ; Retrospective Studies ; Synaptophysin ; metabolism ; Young Adult