The biological activity of chitinase in degrading chitin has garnered extensive attention,particularly for its potential applications in biological control.This study utilized four spore-form-ing Bacillus strains isolated from Dermacentor nuttalli ticks collected in the Hulunbuir region.Traditional bacterial culture methods were employed for isolation and identification,followed by 16S rRNA sequencing and phylogenetic analysis of the purified cultures.chitin-hydrolyzing strains were screened using colloidal chitin plates,and specific chitinase genes were detected via PCR.Fer-mentation was conducted at 37.0 ℃ for 4 d,and the supernatants were subjected to enzyme activity analysis using the DNS method.Four Gram-positive Bacillus strains were successfully isolated from tick tissue samples,they were identified as B.proteolyticus,B.paramycoides,B.thuringien-sis,and B.cereus,and renamed IMH/B-1,IMH/P-1,IMH/T-1,and IMH/C-1,respectively.PCR a-nalysis detected chitinase genes in B.proteolyticus and B.thuringiensis,while B.cereus and B.pa-ramycoides lacked these genes.However,three strains B.proteolyticus,B.thuringiensis,and B.ce-reus demonstrated significant(P＜0.01)chitin degradation activity on colloidal chitin.Enzyme ac-tivity assays revealed that chitinase activity ranged from 1.292 to 2.032 U/mL,with B.proteolytic-us exhibiting the highest activity 2.032 U/mL,followed by B.cereus 1.496 U/mL and B.thuring-iensis 1.324 U/mL.This study provides a foundation for further research and application of chiti-nase-producing Bacillus strains.

The biological activity of chitinase in degrading chitin has garnered extensive attention,particularly for its potential applications in biological control.This study utilized four spore-form-ing Bacillus strains isolated from Dermacentor nuttalli ticks collected in the Hulunbuir region.Traditional bacterial culture methods were employed for isolation and identification,followed by 16S rRNA sequencing and phylogenetic analysis of the purified cultures.chitin-hydrolyzing strains were screened using colloidal chitin plates,and specific chitinase genes were detected via PCR.Fer-mentation was conducted at 37.0 ℃ for 4 d,and the supernatants were subjected to enzyme activity analysis using the DNS method.Four Gram-positive Bacillus strains were successfully isolated from tick tissue samples,they were identified as B.proteolyticus,B.paramycoides,B.thuringien-sis,and B.cereus,and renamed IMH/B-1,IMH/P-1,IMH/T-1,and IMH/C-1,respectively.PCR a-nalysis detected chitinase genes in B.proteolyticus and B.thuringiensis,while B.cereus and B.pa-ramycoides lacked these genes.However,three strains B.proteolyticus,B.thuringiensis,and B.ce-reus demonstrated significant(P＜0.01)chitin degradation activity on colloidal chitin.Enzyme ac-tivity assays revealed that chitinase activity ranged from 1.292 to 2.032 U/mL,with B.proteolytic-us exhibiting the highest activity 2.032 U/mL,followed by B.cereus 1.496 U/mL and B.thuring-iensis 1.324 U/mL.This study provides a foundation for further research and application of chiti-nase-producing Bacillus strains.

Objective To analyze the relationship between leukoaraiosis (LA) and cerebral microbleeds (CMBs).Methods One hundred and thirteen patients with cerebral small vessel diseases,admitted to our hospitals from June 2009 to January 2010,were chosen in our study; MR imagings,including T 1WI,T2WI,fluid-attenuated inversion recovery sequence (FLAIR) and susceptibility weighted imaging (SWI),were performed in all the patients.All patients accepted related blood biochemical tests.The basic clinical data,including gender,age,histories of smoking,alcohol consumption,hypertension and diabetes,and levels of cholesterol (CHOL),triglyceride (TG),high density lipoprotein (HDL),low density lipoprotein (LDL) and fibrinogen (FIB),were collected.Leukoaraiosis was divided into periventricular LA (grade 0-3) and subcortex LA (grade 0-3) according to the results of MR imagings.The number of CMBs lesions were calculated and graded into 0-3.Results The risk factors of age,histories of diabetes and lacunar infaction,and levels of blood glucose and HDL were significantly different between LA patients with or without CMBs (P＜0.05).The distribution of CMBs in patients with periventricular LA and subcortex LA of different grades showed significant differences (P＜0.05).Different classifications ofperiventricular LA were related to different classifications of CMBs (rs=0.506,P=0.000); different classifications of subcortex LA were related to different classifications ofCMBs (rs=0.448,P=0.000); correlation between CMBs and LA was also significant (rs=0.439,P=0.000).Conclusion Old age,histories of diabetes and lacunar infaction,high blood glucose level and low HDL level are risk factors for patients with both LA and CMBs; CMBs and LA are risk factors to each other,and positive correlation between CMBs and LA is noted,which both influenced by cardiovascular risk factors

OBJECTIVETo analyze the risk factors of cerebral microbleeds (CMBs).

METHODSA total of 113 patients with cerebrovascular diseases underwent examinations of magnetic resonance imaging (MRI) of the brain (including T1WI, T2WI, FLAIR, and SWI) and blood biochemical tests, and the brain regions, number and grades of the CMBs were analyzed. The association between CMBs and the cardiovascular risk factors were analyzed.

RESULTSA The occurrence and grade of CMBs were associated with the patients' age, hypertension, diabetes, lacunar infarction, diastolic blood pressure, systolic blood pressure and high-density lipoprotein (HDL) levels (P<0.05). CMB occurrence was significantly associated with diabetes, hypertension, and lacunar infarction (P<0.05), and its incidence varied significantly between different brain regions (P<0.05).

CONCLUSIONAge, hypertension, diabetes, lacunar infarction, diastolic blood pressure, systolic blood pressure, and HDL are all risk factors for CMBs, among which diabetes, hypertension, and lacunar infarction are significant risk factors. CMBs occurs most frequently in the cortex and subcortical region, followed by the basal ganglia, thalamus, and the cerebellum, and most unlikely in the brainstem.

Cerebral Hemorrhage ; epidemiology ; etiology ; pathology ; China ; epidemiology ; Diabetes Complications ; Female ; Humans ; Hypertension ; complications ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Risk Factors