[Study on optimization of image processing parameters of pneumoconiosis by DR]

Objective: To explore the effect of different post-processing parameters of digital radiography (DR) on the quality of chest X-ray for pneumoconiosis diagnosis, and to provide suggestions on parameter setting suitable for this kind of DR machine. Methods: From January 1, 2022 to June 30, 2022, the chest films of 35 workers in the department of radiology of Hangzhou occupational disease prevention and treatment hospital were randomly selected and printed after setting different image post-processing parameters. The quality of chest film was evaluated by the measurement of optical densitometer and the combination of subjective and objective by professional physicians. Results: When the density is set to 2 and the contrast/detail contrast is 4.5, the optical density of each area of DR chest film meets the requirements of chest X-ray quality, and the qualified rate of physician quality evaluation is the highest. Conclusion: Reasonable setting of image post-processing parameters can improve the quality of chest radiograph.

[Research progress on the relation and related mechanism of night shift work and cardiovascular disease]

Cardiovascular disease is a class of diseases involving the heart or blood vessels, which accounts for about one-third of all deaths worldwide each year. Unhealthy diet, lack of physical activity, smoking and excessive alcohol consumption are all risk factors for cardiovascular disease. With the increasing number of night shift workers, the number of patients with cardiovascular disease has increased, and night shift work has gradually become a risk factor of cardiovascular disease. At present, the mechanism of cardiovascular disease caused by night shift work is still unclear. This review summarizes the relationship between night shift work and cardiovascular disease and its related biochemical indicators, and discusses the research on related mechanisms.

Quantum enhancement of a single quantum battery by repeated interactions with large spins

A generalized collision model is developed to investigate coherent charging a single quantum battery by repeated interactions with many-atom large spins, where collective atom operators are adopted and the battery is modeled by a uniform energy ladder. For an initially empty battery, we derive analytical results of the average number of excitations and hence the charging power in the short-time limit. Our analytical results show that a faster charging and an increased amount of the power in the coherent protocol uniquely arise from the phase coherence of the atoms. Finally, we show that the charging power defined by the so-called ergotropy almost follows our analytical result, due to a nearly pure state of the battery in the short-time limit.

[Feasibility study on the preparation of novel negative pressure materials for constructing new matrix of full-thickness skin defect wounds in rats]

Objective: To explore the feasibility on the preparation of novel negative pressure materials for constructing new matrix of full-thickness skin defect wounds in rats. Methods: The experimental research method was applied. The microstructure of polyurethane foam dressing which was commonly used in negative pressure treatment was observed under scanning electron microscope, and its pore diameter was detected (n=5). Polycaprolactone (PCL) and polybutylene succinate (PBS) were used respectively as raw materials for the preparation of PCL and PBS negative pressure materials by melt spinning technology, with the measured pore diameter of polyurethane foam dressing as the spinning spacing at the spinning rates of 15, 25, and 35 mm/s, respectively. The microstructures of the prepared negative pressure materials were observed under scanning electron microscope, and their fiber diameters were measured. The tensile strength and tensile modulus of the prepared negative pressure materials and polyurethane foam dressing were measured by tensile testing machine and composite testing machine, respectively (n=5), to screen the spinning rate for subsequent preparation of negative pressure materials. Human skin fibroblasts (Fbs) in logarithmic growth phase were co-cultured with PCL negative pressure material and PBS negative pressure material prepared at the selected spinning rate, respectively. After 1, 4, and 7 day (s) of co-culture, the cell activity and adhesion in the materials was detected by living/dead cells detection kit, and the cell proliferation level in the materials was detected by cell counting kit 8 method (n=5). A full-thickness skin defect wound was prepared on the back of 18 5-6 weeks old Sprague-Dawley rats (gender unlimited). Immediately after injury, the injured rats were divided into PCL+polyurethane group, PBS+polyurethane group, and polyurethane alone group according to the random number table (with 6 rats in each group). The wounds were covered with materials containing corresponding component and performed with continuous negative pressure suction at the negative pressure of -16.7 kPa. The wound tissue along with materials directly contacted to the wound (hereinafter referred to as wound specimens) were collected from 3 rats in each group after 7 and 14 days of negative pressure treatment (NPT), respectively. The growth of granulation tissue and the attachment of material to wound surface were observed after hematoxylin-eosin staining, the collagen fiber deposition was observed after Masson staining, and CD34 and interleukin-6 (IL-6) positive cells were detected and counted by immunohistochemical staining. Data were statistically analyzed with one-way analysis of variance, analysis of variance for factorial design, least significant difference-t test, Kruskal-Wallis H test, Mann-Whitney U test, and Bonferroni correction. Results: The microstructure of polyurethane foam dressing was loose and porous, with the pore diameter of (815±182) μm. The spinning spacing for the subsequent negative pressure material was set as 800 μm. The microstructures of PBS negative pressure material and PCL negative pressure material were regular, with vertically interconnected layers and continuous fibers in even thickness, but the fibers of PBS negative pressure material were straighter than those of PCL negative pressure material. There was no obvious difference in the microstructure of negative pressure materials prepared from the same raw material at different spinning rates. The fiber diameters of PCL negative pressure materials prepared at three spinning rates were similar (P>0.05). The fiber diameters of PBS negative pressure materials prepared at spinning rates of 25 mm/s and 35 mm/s were significantly smaller than the fiber diameter of PBS negative pressure material prepared at the spinning rate of 15 mm/s (with t values of 4.99 and 6.40, respectively, P<0.01). Both the tensile strength and tensile modulus of PCL negative pressure materials prepared at three spinning rates were similar (P>0.05). The tensile strength of PBS negative pressure materials prepared at spinning rates of 15 mm/s and 25 mm/s was significantly lower than that of PBS negative pressure materials prepared at the spinning rate of 35 mm/s (with t values of 9.20 and 8.92, respectively, P<0.01), and the tensile modulus was significantly lower than that of PBS negative pressure materials prepared at the spinning rate of 35 mm/s (with t values of 2.58 and 2.47, respectively, P<0.05). Subsequently, PCL negative pressure material was prepared at the spinning rate of 35 mm/s, and PBS negative pressure material was prepared at the spinning rate of 15 mm/s. After 1, 4, and 7 day (s) of co-culture, the number of human skin Fbs that adhered to PCL negative pressure material and PBS negative pressure material increased with time, and there was no significant difference between the two materials. After 1 and 7 day (s) of co-culture, the proliferation levels of human skin Fbs between the two negative pressure materials were similar (P>0.05). After being co-cultured for 4 days, the proliferation level of human skin Fbs in PBS negative pressure material was significantly higher than that in PCL negative pressure material (t=6.37, P<0.01). After 7 days of NPT, the materials were clearly identifiable and a small amount of collagen fibers were also observed in the wound specimens of rats in the three groups; a small amount of granulation tissue was observed in the wound specimens of rats in polyurethane alone group. After 14 days of NPT, a large number of granulation tissue and collagen fibers were observed in the wound specimens of rats in the three groups; the materials and wound tissue in the wound specimens of rats in PCL+polyurethane group could not be clearly distinguished. After 7 and 14 days of NPT, the collagen fibers in the wound specimens of rats in polyurethane alone group were denser than those in the other two groups. After 7 days of NPT, the number of CD34 positive cells in the wound specimens of rats in PBS+polyurethane group was 14.8±3.6 per 400 times visual field, which was significantly less than 27.8±9.1 in polyurethane alone group (t=3.06, P<0.05); the number of IL-6 positive cells was 60 (49, 72), which was significantly more than 44 (38, 50) in polyurethane alone group (Z=2.41, P<0.05). After 14 days of NPT, the number of IL-6 positive cells in the wound specimens of rats in PBS+polyurethane group was 19 (12, 28) per 400 times visual field, which was significantly more than 3 (1, 10) in PCL+polyurethane group and 9 (2, 13) in polyurethane alone group (with Z values of 2.61 and 2.40, respectively, P<0.05). Conclusions: The prepared PCL negative pressure material and PBS negative pressure material have good biocompatibility, and can successfully construct the new matrix of full-thickness skin defect wounds in rats. PCL negative pressure material is better than PBS negative pressure material in general.

[Research progress on the role of lncRNA in the occurrence and development of malignant mesothelioma]

Malignant mesothelioma (MM) is a long latency, poor prognosis and asbestos exposure related malignant disease. Long non-coding RNA (lncRNA) is a kind of RNA with a length of more than 200 nucleotides that does not encode protein. It plays an important role in epigenetic regulation, cell cycle regulation and cell differentiation regulation. Recent studies have shown that the abnormal expression or function of lncRNA is closely related to the diagnosis and prognosis of MM. In this paper, the lncRNA research on MM is reviewed to better understand the role of lncRNA in MM.

[Effect of PPAR-γ agonist pioglitazone on the prolifeiration of malignant nesothelionma cells induced by HMGB1]

Objective: To investigate the effect and mechanism of PPAR-γ agonist Pioglitazone (PGZ) on the proliferation of malignant mesothelioma (MM) cells. Methods: In December 2019, MM cell lines MSTO-211H and NCI-H2452 were incubated with different final concentrations of PGZ (0, 10, 50, 100, 150, and 200 μmol/L) for different periods of time (24 h, 48 h, and 72 h) , and then the cell proliferation level was detected by CCK8 assay. After given various final concentration of PGZ (0, 10, 50, 100, 150, 200 μmol/L) the for 72 hours, the changes of number and morphology of MM cells were observed under an inverted microscope. The expressions of PPAR-γ and HMGB1 mRNA were determined by real-time fluorescence quantitative reverse transcription-polymerase chain reaction (qRT-PCR) after treatment of MM cells with PGZ of 0, 10, 50, 100 μmol/L for 72 h. The MM cells were treated with PGZ at concentration of 0, 100 μmol/L for 72 h, and the protein expressions of HMGB1 were examined using Western blotting and immunofluorescence; the protein expressions of Ki67 were assessed by immunohistochemistry. Results: The cell viability rate of MM cells was decreased after treated with PGZ (P<0.05) . Cell number in PGZ-treated group was significantly less than that in control group and morphology changes were observed under light microscope. QRT-PCR results revealed significantly increased PPAR-γ mRNA expression in the PGZ-treated group compared to the control group (P<0.05) . There was a significant decrease in the mRNA expression level of HMGB1 in the PGZ-treated group (100 μmol/L) as compared to the control group in MSTO-211H (P<0.05) ; however, the expression level of HMGB1 in NCI-H2452 was an increase or no significant differences (P>0.05) . Western blotting and immunofluorescence results showed that the protein expression of HMGB1 was reduced in the PGZ-treated group compared with the control group in MSTO-211H (P<0.05) , but the protein expression of that in NCI-H2452 was no significant differences (P>0.05) . Immunohistochemistry results showed increased expression of proliferation marker Ki-67. Conclusion: Pioglitazone suppresses the proliferation of MM cells through inhibition of HMGB1 by the activation of PPAR-γ.

[The impact of CD8 and CTLA-4 expression on histopathological character and survival in mesothelioma]

Objective: To investigate the survival and death risk factors of mesothelioma cases stratified by the expression levels of CD8 and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) , providing new clue to evaluate disease progression and clinical outcome. Methods: This was a retrospective case report, which included 47 clinically and pathologically confirmed mesothelioma cases on November 2016. Their clinical and pathological information, asbestos exposure history and survival data were collected. Infiltrated lymphocyte, 5-methylcytosine (5-mC) , CTLA-4, CD8 and Ki-67 antigen were detected using hematoxylin-eosin staining and immunohistochemistry. Survival time and death risk factors of mesothelioma patients with different CD8 and CTLA-4 protein expression characteristics were analyzed. And analyze the influence of Ki-67 expression on the survival of patients with different CD8 and CTLA-4 protein and gene expression characteristics. Results: Among the 47 cases, 63.8% (30/47) had low/medium level of infiltrated lymphocyte. The immunohistochemistry scores of CTLA-4, CD8, 5-mC and Ki-67 were 92.97 (54.95, 120.65) , 72.41 (36.62, 89.82) , 11.09 (3.40, 52.89) and 5.88 (2.41, 11.48) , respectively. Patients with CD8(high) CTLA-4(high) had higher 5-mC level than those with CD8(high) CTLA-4(low) (P<0.01) . The median survival time of 27 cases was 0.83±0.29 year. The median survival times of those with CD8(high) CTLA-4(high) and CD8(high) CTLA-4(low) were 0.58±0.51 year and 0.83±0.30 year, respectively (P=0.521) . The immunohistochemistry score of Ki-67 ≥5.88 was an independent death risk factor for patients with CD8(high) CTLA-4(low) (HR=8.40, P=0.01) . Under different CD8 and CTLA-4 protein expression characteristics, in the patients with CD8(high) CTLA-4(low), the median survival times of those with high and low Ki-67 expression were 0.57±0.11 years and 2.31±0.46 years, respectively (P<0.01) . Under different CD8 and CTLA-4 mRNA expression characteristics, in the patients with CD8(high) CTLA-4(low), the median survival times of those with high and low Ki-67 mRNA expression were 1.20±0.36 years and 3.38±0.43 years, respectively (P=0.018) . Conclusion: Mesothelioma case with high CD8 but low CTLA-4 content might coexist DNA hypomethylation. In the presence of high Ki-67 expression, their survival time appears to be shortened with increased death risk.

[Analysis of influencing factors of textile workers' occupational stress]

Objective: To explore the occupational stress status and influencing factors of workers in a textile factory in Zhejiang Provice. Methods: In October 2018, 505 workers from a textile factory in Zhejiang Province were selected as research objects by convenient sampling method. A total of 505 questionnaires were distributed, 495 of which were effective and the effective recovery rate was 98.0%. Job Content Questionnaire (JCQ) and Effort Reward Imbalance Questionnaire (REI) were used to investigate textile workers' occupational stress and analyze its influencing factors. The differences of the composition ratio of different groups were tested by χ(2) test. The influencing factors such as age, gender and occupation on occupational stress were analyzed by multivariate logistic regression. Results: ERI analysis results showed that the high and low occupational stress accounted for 30.1% and 69.9%, respectively. The differences of occupational stress among workers of different job types and working ages were statistically significant (P<0.05) . The detection rates of high occupational stress of paper workers and spinners were 47.8% (11/23) and 44.8% (30/67) , respectively, higher than other jobs. The detection rate of high occupational stress for workers with more than 5 years of service was 46.4% (13/28) . The results of JCQ analysis showed that there was no statistical significance in the differences of daily working hours and length of service between different gender, education levels, types of work patterns, and occupational stress (P>0.05) . Job types had significant effects on the occupational stress defined by ERI (P<0.05) , the risk of occupational stress was 2.151 times than that of the coiler. Conclusion: There are significant differences in occupational stress risk among workers of different types of work in textile industry, so different measures should be taken to prevent and control occupational stress in different jobs.

[Task-related functional connectivity of anterior cingutate in opiate drug addicts during physical detoxification: a task fMRI study]

Objective: To explore the brain areas which have abnormal functional connectivity with anterior cingutate in opiate drug dependence during physical detoxification using a task-related functional magnetic resonance imaging(fMRI), and to find out the role of anterior cingutate dysfunction in the relapse of opiate drug addicts during physical detoxification. Methods: From January to December 2016, eighteen participants of opiate drug addicts during physical detoxification who completed in Drug Rehabilitation Center of Anhui Province, and eighteen healthy controls recruited performed a cue-elicited craving task in a MRI scanner while signal data were collected. Two regions of interest were the right anterior cingutate and the left anterior cingutate, then the linear correlation between the whole brain and the anterior cingutates was calculated to find out the abnormal functional connectivity of the anterior cingutates. Results: Contrasted experimental group with the healthy controls, the functional connectivity of bilateral fusiform gyrus, caudate nucleus, and the anterior cingutates was increased in the opiate drug addicts during physical detoxification group (P<0.05),and the functional connectivity between anterior cingutates and polus temporalis, hippocampi, Middle frontal gyrus of orbit, Supplementary motor area, dorsolateral superior frontal gyrus was decreased(P<0.05). Conclusion: The anterior cingutates dysfunction of functional connectivity in a cue-elicited craving task may play a important role in the relapse of opiate drug addicts during physical detoxification.

[Comparison of the accuracy of neuronavigation and linear measurement in the positioning of parasagittal meningioma]

Objective: To explore the accuracy of preoperative positioning of neuronavigation and linear measurement localization in the parasagittal meningioma. Methods: Thirty-eight patients with parasagittal meningioma who underwent neurosurgery in the First Affiliated Hospital of Bengbu Medical College from January 2016 to April 2018 were preoperatively positioned with neuronavigation localization and linear measurement localization. The actual position of the tumor was observed during operation, and the accuracy of the two methods was compared. The time taken by the neural navigation positioning and the linear measurement positioning method was recorded, and the difference between the two methods was compared. Results: All cases were treated with neuronavigation and linear measurement, and the tumors were completely exposed after localization. Compared with the actual tumor center position measured during surgery, the average error distance between 38 nerve navigation and actual tumor center position was (2.7±1.9) mm, and the average error distance between linear measurement and actual tumor center position was (3.2±1.3) mm. The difference was not statistically significant, P value=0.207. Neuronavigation includes booting, data import, registration, positioning, etc., which takes an average of (22.3±2.3) minutes. The linear positioning method included image data measurement and localization, and the average time was(1.7±0.3) minutes. The difference between the two groups was statistically significant, and the P value was less than 0.001. Conclusion: The linear measurement localization method and the neuronavigation localization method have good accuracy for preoperative localization of the parasagittal meningioma.

[Application of modified brain protection double-lumen drainage tube in external drainage of chronic subdural hematoma]

Objective: To compare the clinical effects of modified double-lumen drainage tube and traditional silicone tube in external drainage of chronic subdural hematoma. Methods: Selected 49 patients suffering from chronic subdural hematoma hospitalized in the Department of Neurosurgery, the First Affiliated Hospital of Bengbu Medical College between July 2016 and June 2018 who underwent external drainage, and divided them randomly into experimental groups (using modified brain protection double lumen drainage tube in 23 cases) and control group (using traditional silicone drainage tube in 26 cases). Comparison of postoperative hematoma residual volume, the tube indwelling time, the numbers of drainage tube contact with brain tissue and arachnoid membrane, the numbers of infections, the numbers of postoperative epilepsy cases, and changes in Modified Rankin Scale scores between the two groups. Results: At the time of extubation, the residual amount of hematoma in the experimental group was (13±7) ml, and that in the control group was (17±8) ml. There was no significantly statistical difference in the residual amount of hematoma between the experimental group and the control group (P>0.05). The tube indwelling time of the experimental group was (2.0±0.9) days, and that of the control group was (2.7±0.8) days. The difference between the experimental group and the control group in the drainage tube indwelling time was statistically significant (P<0.05). No cases of drainage tube contact with brain tissue and/or arachnoid membrane appeared in the experimental group, and 7 cases of drainage tube contact with brain tissue or arachnoid membrane appeared in the control group. No infection occurred in both groups. No cases of epilepsy occurred in preoperative, and there were 0 cases of epilepsy in the experimental group and 1 case in the control group in postoperative. There were significantly statistical differences in each of the two groups in the modified Rankin scale before and after surgery (P<0.001), there was no significant difference in postoperative Modified Rankin Scale scores between the two groups. Conclusion: The modified brain protection double-lumen drainage tube has good drainage effect in the external drainage of chronic subdural hematoma, and the short tube retention time, causing fewer complications. It is a safe and effective tool for treating chronic subdural hematoma, and it is worthy of clinical promotion.

Extraction of DNA from Sperm Cells in Mixed Stain by Nylon Membrane Bushing Separation Technique

OBJECTIVES

To establish a novel method for the separation of sperm cells in mixed stain, and to evaluate its application value.

METHODS

Totally 40 mixed stain samples were collected from sexual assault cases. Sperm cells were separated by the conventional differential lysis method and the nylon membrane bushing separation technique, respectively. The DNA of sperm cells was extracted with the silicon membrane kit （Forensic DNA Extraction Kit for Soft Tissues）. The PCR amplification was performed using AmpFℓSTR® Identifiler® Plus kit, and the products were electrophoresed by 3500xL genetic analyser. The results of two separation methods were then compared.

RESULTS

Complete and single-source male STR genotypes could be obtained from all the 40 mixed stain samples except three samples with minimal residual of female DNA by the nylon membrane bushing separation technique. The STR genotypes of sperm cells could not be detected in 25 samples, which were obtained in 15 samples （seven were of incomplete male STR genotypes, six with residual of female DNA, two were complete and single-source STR genotypes of sperm cells）.

CONCLUSIONS

The nylon membrane bushing separation technique developed in present study can be used in the separation of sperm cells in mixed stain, especially for the extraction of a small amount of sperm from a large quantity of female cells, which is inexpensive, rapid and simple.

[Application of star card in edge enhancement processing of pneumoconiosis DR image]

Objective: The feasibility of applying DR card in the quality control of chest film of pneumoconiosis was discussed by using the image detail change of 1 degree star card. Methods: With different types of grid DR device for star card photography, to ensure that the grid bars are orthogonal to the direction of star card image quality is stable, conforms to the DR standard of pneumoconiosis image edge enhancement processing, analysis of the relationship between lung tissue image changes and changes with fuzzy star card. By 3 physicians blind reading way, compare the use of auxiliary judgment and direct x-ray star catu judgment in the accuracy evaluation of whether the use of edge enhancement function. Results: Fuzzy images of star card were consistent with lung tissues details as DR images were treated with edge enhancement. The fuzzy zore was closer to the start card center with more image edge enhancement and more image details sharpening. on the opposite, it was farther from the center with less with edge enhancement and less image sharpening. It's valuable for star card analysis to evaluate the accuracy of the application of image edge enhancement (P<0.001). Conclusion: To determine whether the use of X-ray star catu edge feasible enhancements can be used for health supervision and quality supervision and quality control of the institution itself of radiology.

[Window settings in the application of pneumoconiosis digital radiography]

Objective: To explore window settings technology in the digital radiography of pneumoconiosis, and to improve the quality of the digital chest radiographs. Methods: 25 female workers in a asbestos product processing enterprise were examined with high-kV and DR chest radiographies on same day. Consistency of pneumoconiosis diagnosis results: were assessed. Results In the 75 groups of radiograph quality results, there are 62 groups that need to be processed window in order to make the correct diagnosis. The crude agreement among two chest radiographs was 28% for the profusion of small opacities and 76% for the classification of pneumoconiosis, the weighted kappa value (κ) was 0.33 (95%CI: 0.12-0.54) and 0.67 (95%CI: 0.42-0.92) . Conclusions: window settings technology can display different parts of chest and make DR chest radiograph to meeting the requirements of chest radiograph quality for pneumoconiosis.

[Analyzing the mental health status and its impact factors among female nurses in China]

Objective: To analyze the mental health status and its impact factors among nurses, finding ways to improve the mental health of nurses. Methods: A total of 13 425 female healthcare workers aged from 18 to 65 were selected as study objects. The survey was conducted with unified design questionnaire. The survey included the basic situation of the individuals and SCL-90 questionnaire. Comparing the female doctors, the mental health status and its impact factors of nurses were analyzed. Results: The income, age, education and occupation, which include shift work, heavy work load and overtime work are different between nurses and doctors. The main mental health problems of nurses were obsessive-compulsive symptoms, depressive symptoms and somatization. The results of univariate analysis indicated that shift work, overtime work, and heavy work load affected the positive rate of each factor. The results of multivariate analysis showed that occupation, shift work, overtime work, and heavy work load have significant adverse effects on the positive rate of the total score in female healthcare workers (P<0.01) . The positive rate of each dimension of SCL-90 in nurses is significantly higher than that of doctors. Conclusion: The mental health problems of nurses are significantly higher than doctors. The main reasons are low occupational level and adverse workstyles which include shift work, heavy workload and so on. Health administration and hospital management departments should pay much more attention to the mental health of nurses, improving their mental health through a variety of ways.

[Curative effect analysis of two surgical methods for removal of pituitary adenoma via endonasal transsphenoidal approach]

Objective: To compare the efficacy of endoscopic endonasal transsphenoidal surgery and microsurgery for pituitary adenomas. Methods: One hundred and ten patients with pituitary adenoma who were treated by single nostril transsphenoidal surgery in the department of neurosurgery of the First Affiliated Hospital of Bengbu Medical College from June 2014 to December 2016 were enrolled.These cases were randomly divided into endoscopic group 53 cases (including 36 cases of functional pituitary adenoma and 17 cases of non-functional pituitary adenoma) and microscope group 57 cases (including 34 cases of pituitary adenoma and 23 cases of non-functional pituitary adenomas), with no significant difference in preoperative clinical data about gender, age, tumor size and endocrine function (P>0.05). The total tumor resection rate, postoperative complication rate and the rate of functional tumor hormone levels were compared between the two groups. Results: The total resection rate of tumor in patients with endoscope and microscope group were 75.5% (40/53) and 70.2% (40/57) without statistically significant difference (P>0.05). The total resection rate and hormone level decline effective rate of functional pituitary adenomas in neuroendoscope group (91.7%, 33/36; 83.3%, 30/36) were higher than those in microscope group (70.6%, 24/34; 61.8%, 21/34) with statistically significant difference (P<0.05). Another side, there was no statistically significant difference in total resection of non-functional pituitary adenomas between endoscope group (41.2%, 7/17) and microscope group (69.6%, 16/23) (P>0.05). The total incidence of postoperative complications in endoscopic group (9.4%, 5/53) was lower than that in the microscope group (24.6%, 14/57), with statistically significant difference (P<0.05), in which the rate of postoperative complications of functional pituitary adenomas and nonfunctional pituitary adenoma in endoscopy group (8.3%, 3/36; 11.8%, 2/17) and in microscope (20.6%, 7/34; 30.4%, 7/23) had no statistical significance (P>0.05). Conclusion: Pituitary adenoma resection rate in two ways had no obvious difference, but the advantages of endoscopic surgery for functional pituitary adenomas were obvious.The incidence of postoperative complications of endoscopic surgery was lower than that of microscopic surgery, but there was no difference between functional and non-functional tumors.

[Application of low profile visualized intraluminal support (LVIS)stents in assisting coil embolization of intracranial aneurysms]

Objective: To evaluate the safety and effectiveness of application of LVIS stent-assisted coiling endovascular procedures in cerebral aneurysms . Methods: The clinical data of 41 patients with intracranial aneurysms , which were performed in LVIS stent-assisted coiling endovascular therapies from June 2015 to October 2017 in The First Affiliated Hospital of Bengbu Medical College were analyzed retrospectively. 13 patients were unruptured and 28 patients were ruptured. Immediate angiography outcomes and follow-up angiography outcomes were assessed by DSA. Clinical outcomes were evaluated by modified Rankin Scale (mRS). Results: The LVIS stents were successfully delivered in 39 cases, however there were 2 cases in which the LVIS stents did not fully open.The technical success rate was 95.1%(39/41). There were 2 cases had complications during perioperation, the rate of complications was 4.9%(2/41). One was thrombus formation in operation, there was no nerve function defect.The other was infarction three days after operation and which had mild function defect(mRS grade 2). Raymond grade 1 was 31 cases, Grade 2 was 2 cases , grade 3 was 8 cases, the effective embolism rate was 80.5%(33/41). Mean follow up time was 14.4 months, 32 cases were cured, the cure rate was 78.0%(32/41), 2 cases were reappeared, the recurrence rate was 4.9%(2/41). mRS grade 0 was 16 cases, grade 2 was 24 cases , grade 2 was 1 case , the cure rate of clinical symptom is 100%. Conclusion: LVIS stent-assisted coiling is safe and effective in the treatment of cerebral aneurysms.

Comparison and analysis of Wuding and avian chicken skeletal muscle satellite cells

Chicken skeletal muscle satellite cells are located between the basement membrane and the sarcolemma of mature muscle fibers. Avian broilers have been genetically selected based on their high growth velocity and large muscle mass. The Wuding chicken is a famous local chicken in Yunnan Province that undergoes non-selection breeding and is slow growing. In this study, we aimed to explore differences in the proliferation and differentiation properties of satellite cells isolated from the two chicken breeds. Using immunofluorescence, hematoxylin-eosin staining and real-time polymerase chain reaction analysis, we analyzed the in vitro characteristics of proliferating and differentiating satellite cells isolated from the two chicken breeds. The growth curve of satellite cells was S-shaped, and cells from Wuding chickens entered the logarithmic phase and plateau phase 1 day later than those from Avian chicken. The results also showed that the two skeletal muscle satellite cell lines were positive for Pax7, MyoD and IGF-1. The expression of Pax7 followed a downward trend, whereas that of MyoD and IGF-1 first increased and subsequently decreased in cells isolated from the two chickens. These data indicated that the skeletal muscle satellite cells of Avian chicken grow and differentiate faster than did those of Wuding chickens. We suggest that the methods of breeding selection applied to these breeds regulate the characteristics of skeletal muscle satellite cells to influence muscle growth.

[Research on the application of "H shaped" single-tube double-lumen drainage tube in the treatment of chronic subdural hematoma]

OBJECTIVE

To explore the effect of chronic subdural hematoma external drainage surgery using self-made "H shaped" flush type single-tube double-lumen drainage tube.

METHODS

There were 56 cases chosen from the First Affiliated Hospital of Bengbu Medical College between Jan 2013 and Aug 2015. These patients with unilateral chronic subdural hematoma requiring surgery to place drilling external drainage catheter were randomly divided into group A (21 cases, using self-made single-tube double lumen "H shaped" drainage tube) and group B (35 cases, traditional silicone drainage tube), then the residual liquid volume after drainage on the first day, the days that the tube stay in body and the residual fluid volume after removing the tube were compared between the two groups.

RESULTS

The residual liquid volume after drainage on the first day in group A was (23±15)ml, in group B was (31±15)ml. The days that the tube stay in body in group A was (2.7±1.0)d, in group B was (3.3±1.1)d, the two groups had statistical differences (P<0.05). The residual fluid volume after removing the tube in group A was (13±7) ml, in group B was (16±8)ml, but the data in these two groups had no significantly statistical differences (P>0.05).

CONCLUSION

The effect of self-made "H shaped" flush type single-tube double-lumen drainage tube in the drainage of chronic subdural hematoma drainage is good, with short tube stay in the body; therefore, it is a safe and effective way to treat chronic subdural hematoma, and is worthy of clinical application.

Effect of early vitamin D supplementation on asthma and the possible mechanisms

Asthma is a chronic inflammatory disease of the airways with variable airflow obstruction and bronchial hyper-responsiveness. It is believed that Th2-derived cytokines orchestrate the asthmatic response and the maintenance of the balance of Th1/Th2 plays a crucial role in prevention of asthma. Moreover, 1,25(OH)2D3, the biologically activate form of vitamin D, was reported with an almost opposite role in prevention and treatment of asthma. Therefore, in this study, we elucidated the evaluations of in vivo anti-asthma effects when treated with different doses of vitamin D and validated the relationship between vitamin D and asthma. Our data demonstrated that intervention with the appropriate dose of 1,25(OH)2D3 in early life could improve pulmonary function and reduce eosinophil cell infiltration in the airways of rat asthma models. However, overdose might play a detrimental effect. Its mechanism may correlate with the effect of 1,25(OH)2D3 on interleukin (IL)-4, IL-12, IL-13, interferon-γ, and ovalbumin-specific immunoglobulin E secretion and the expression of p-JAK1/p-STAT6/SOCS5.

High-level production of β-1,3-1,4-glucanase by Rhizomucor miehei under solid-state fermentation and its potential application in the brewing industry

AIMS

To improve the β-1,3-1,4-glucanase production by Rhizomucor miehei under solid-state fermentation (SSF) for industrial application.

METHODS AND RESULTS

The fermentation conditions for β-1,3-1,4-glucanase production by R. miehei CAU432 under SSF were optimized using a 'one-factor-at-a-time' method. Under the optimized fermentation conditions, viz. oatmeal (0·45-0·9 mm) as sole carbon source, 5% (w/w) peptone as sole nitrogen source, initial moisture of 80% (w/w), initial culture pH of 5·0, incubation temperature of 50°C and incubation time of 6 days, the highest β-1,3-1,4-glucanase activity of 20,025 U g(-1) dry substrate was achieved, which represents the highest yield for β-1,3-1,4-glucanase production ever reported. The crude enzyme was extracted and purified to homogeneity with a purification fold of 4·6 and a recovery yield of 9·0%. The addition of the purified β-1,3-1,4-glucanase in mash obviously reduced its filtration time (24·6%) and viscosity (2·61%).

CONCLUSIONS

The optimal fermentation conditions for maximal β-1,3-1,4-glucanase production under SSF was obtained, and the enzyme was suitable for application in the malting process.

SIGNIFICANCE AND IMPACT OF THE STUDY

The high production yield and excellent capability of the enzyme may enable it great potential in industries, especially in brewing industry.

Astragalus membranaceus lectin (AML) induces caspase-dependent apoptosis in human leukemia cells

OBJECTIVES

Recently, plant lectins have attracted great interest due to their various biological activities such as anti-cancer, anti-fungal and anti-viral activities. We have reported earlier concerning anti-proliferation of human cancer cell lines by a galactose-binding lectin (AML), from a Chinese herb, ASTRAGALUS MEMBRANACEUS: In the present study, detailed investigations into the mechanism of such anti-proliferation properties have been carried out.

MATERIALS AND METHODS

Mechanism of apoptosis initiation in K562 cells by AML was investigated by morphology, flow cytometry and western blot analysis.

RESULTS

AML induced apoptosis in a caspase-dependent manner in the chronic myeloid leukemia cell line, K562. Furthermore, we observed that cytotoxicity and apoptosis of K562 cells induced by AML were completely abolished in presence of lactose or galactose.

CONCLUSIONS

Our results suggest that AML could act as a potential anti-cancer drug.

A xylose-tolerant beta-xylosidase from Paecilomyces thermophila: characterization and its co-action with the endogenous xylanase

An extracellular beta-xylosidase from the thermophilic fungus Paecilomyces thermophila J18 was purified 31.9-fold to homogeneity with a recovery yield of 2.27% from the cell-free culture supernatant. It appeared as a single protein band on SDS-PAGE with a molecular mass of approx 53.5 kDa. The molecular mass of beta-xylosidase was 51.8 kDa determined by Superdex 75 gel filtration. The enzyme was a glycoprotein with a carbohydrate content of 61.5%. It exhibited an optimal activity at 55 degrees C and pH 6.5, respectively. The enzyme was stable in the range of pH 6.0-9.0 and at 55 degrees C. The purified enzyme hydrolyzed xylobiose and higher xylooligosaccharides but was inactive against xylan substrates. It released xylose from xylooligosaccharides with a degree of polymerization ranging between 2 and 5. The rate of xylose released from xylooligosaccharides by the purified enzyme increased with increasing chain length. It had a K(m) of 4.3mM for p-nitrophenol-beta-d-xylopyranoside and was competitively inhibited by xylose with a K(i) value of 139 mM. Release of reducing sugars from xylans by a purified xylanase produced by the same organism increased markedly in the presence of beta-xylosidase. During 24-hour hydrolysis, the amounts of reducing sugar released in the presence of added beta-xylosidase were about 1.5-1.73 times that of the reaction employing the xylanase alone. This is the first report on the purification and characterization of a beta-xylosidase from Paecilomyces thermophila.

Production of xylobiose from the autohydrolysis explosion liquor of corncob using Thermotoga maritima xylanase B (XynB) immobilized on nickel-chelated Eupergit C

In this study, a thermostable recombinant xylanase B (XynB) from Thermotoga maritima MSB8 was immobilized on nickel-chelated Eupergit C 250L. This immobilized XynB was then used to hydrolyze the autohydrolysis explosion liquor of corncob (AELC) in a packed-bed enzyme reactor for continuous production of xylooligosaccharides, especially xylobiose. When tested in batch hydrolysis of AELC, the immobilized XynB still retained its relative activity of 92.5% after 10 cycles of hydrolysis at 90 degrees C. The immobilized XynB retained 83.6% of its initial hydrolysis activity even after 168 h of hydrolysis reaction at 90 degrees C and demonstrated a half-life time of 577.6 h (24 days) for continuous hydrolysis. HPLC showed that xylobiose (49.8%) and xylose (22.6%) were the main hydrolysis products yielded during continuous hydrolysis. Xylobiose was adsorbed on an activated charcoal column and eluted with a linear gradient of 15% (v/v) ethanol to yield xylobiose with 84.7% of recovery. Also, the purity of xylobiose was up to 97.2% as determined by HPLC. Therefore, the immobilized XynB was suitable for the efficient production of xylobiose from AELC. This is the first report on the immobilization of xylanase for xylobiose production.

Ethnicity and risk factors in needle sharing among intravenous drug users in Sichuan Province, China

Combining survey and ethnographic data, this research examined differences in the risk factors associated with needle sharing amongst intravenous drug users (IDUs) in the Sichuan Province of China. A comparison was made between the province's majority Han population and its Yi minority. We developed a theoretical framework consisting of risk factors at the individual level (including risk factors such as lack of AIDS knowledge, low self-efficacy, and economic pressure), interpersonal level (having an IDU primary partner and lack of family support), and community level (social discrimination). The findings suggested that the Yi minority group was more socially disadvantaged and had a higher risk of contracting HIV than the Han group. Furthermore, the factors that put them at risk were different to those which affected the Han group. OLS regression results showed that, for Han IDUs, needle sharing was positively associated with having an IDU primary partner and with economic pressure. On the other hand, for the minority group, needle sharing was significantly associated with being male, AIDS knowledge, the lack of family support, and social discrimination. These findings highlight the need for HIV prevention work to target marginalized populations in China, such as ethnic minorities, and to tailor appropriate prevention strategies to meet the specific needs of different groups.

High-level of xylanase production by the thermophilic Paecilomyces themophila J18 on wheat straw in solid-state fermentation

The production of extracellular xylanase by a newly isolated thermophilic fungus, Paecilomyces themophila J18, on the lignocellulosic materials was studied in solid-state fermentation (SSF). The strain grew well at 50 degrees C and produced a high-level of xylanase activity using the selected lignocellulosic materials, especially wheat straw. Production of xylanase by P. themophila J18 on wheat straw was enhanced by optimizing the particle size of wheat straw, nitrogen source, initial moisture level, growth temperature and initial pH of the culture medium. Under the optimized conditions, yield as high as 18,580 Ug(-1) of carbon source of xylanase was achieved. No CMCase activity was observed. The xylanase exhibited remarkable stability and retained more than 50% of its original activity at 70 degrees C for 4h at pH 7.0-8.0. Therefore, P. themophila J18 could to be a promising microorganism for thermostable, cellulase-free xylanase production in SSF.

Characterization of a cellulase-free, neutral xylanase from Thermomyces lanuginosus CBS 288.54 and its biobleaching effect on wheat straw pulp

A xylanase purified from the thermophilic fungus Thermomyces lanuginosus CBS 288.54 was characterized and its potential application in wheat straw pulp biobleaching was evaluated. Xylanase was purified 33.6-fold to homogeneity with a recovery yield of 21.5%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of approx. 26.2 kDa. The purified xylanase had a neutral optimum pH ranging from pH 7.0 to pH 7.5, and it was also stable over pH 6.5-10.0. The optimal temperature of the xylanase was 70-75 degrees C and it was stable up to 65 degrees C. The purified xylanase was found to be not glycosylated. The xylanase was highly specific towards xylan, but did not exhibit other enzyme activity. Apparent Km values of the xylanase for birchwood, beechwood, soluble oat-spelt and insoluble oat-spelt xylans were 4.0, 4.7, 2.0 and 23.4 mg ml-1, respectively. The potential application of the xylanase was further evaluated in biobleaching of wheat straw pulp. The brightness of bleached pulps from the xylanase pretreated wheat straw pulp was 1.8-7.79% ISO higher than that of the control, and showed slightly lower tensile index and breaking length than the control. Although chlorine consumption was reduced by 28.3% during bleaching, the xylanase pretreated pulp (15 U g-1 pulp) still maintained its brightness at the control level. Besides, pretreatment of pulp with the xylanase was also effective at an alkaline pH as high as pH 10.0.

Biobleach boosting effect of recombinant xylanase B from the hyperthermophilic Thermotoga maritima on wheat straw pulp

The recombinant xylanase B (XynB) of Thermotoga maritima MSB8 was found to be highly specific towards xylans and exhibit very low activity towards carboxymethylcellulose in previous study. XynB was thermostable at neutral to alkaline pH region at 90 degrees C and retained more than 90% activity after 1 h over the pH range of pH 6.1 to 11.1. The suitability of XynB for use in the biobleaching of wheat straw pulp was investigated. Pretreatment of the pulp with XynB resulted in a substantial improvement in the bleachability of wheat straw pulp. When XynB at 10 U g(-1) was used to treat wheat straw pulp, it reduced pulp kappa number by 1.1 point, enhanced pulp brightness by 5.5% (% ISO) and improved other pulp properties, such as tensile index and breaking length. Biobleaching of wheat straw pulp with XynB saved active chlorine up to 34.5% while still maintaining the brightness at the control level. Besides, pretreatment of pulp with XynB was also effective at an alkaline pH as high as pH 10.1. This is the first report on the potential application of XynB from T. maritima MSB8 in the pulp and paper sector.

Characterization of a xylanase from the newly isolated thermophilic Thermomyces lanuginosus CAU44 and its application in bread making

AIMS

A xylanase from the newly isolated thermophilic fungus, Thermomyces lanuginosus CAU44, was characterized and evaluated for its suitability in bread making.

METHODS AND RESULTS

Xylanase was purified 3.5-fold to homogeneity with a recovery yield of 32.8%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of c. 25.6 kDa. The purified xylanase had an optimum pH of 6.2, and it was stable over pH 5.6-10.3. The optimal temperature of xylanase was 75 degrees C and it was stable up to 65 degrees C at pH 6.2. Study was further carried out to investigate the effect of the purified xylanase on the properties of wheat bread and its staling during storage.

CONCLUSIONS

The purified xylanase from T. lanuginosus CAU44 was stable up to 65 degrees C and had a broad pH range. The presence of thermostable xylanase during bread making led to an improvement of the specific bread volume and better crumb texture. Besides, addition of xylanase provided an anti-staling effect.

SIGNIFICANCE AND IMPACT OF THE STUDY

The xylanase from the newly isolated Thermomyces lanuginosus CAU44 shows great promise as a processing aid in the bread-making industry.

[Artificial reconstituted pulmonary surfactant used for prevention and treatment of adult respiratory distress syndrome. III. Prevention in animal model]

Based on two major factors resulted in adult respiratory distress syndrome (ARDS), lack of pulmonary surfactant and damage of free radicals, an artificial reconstituted pulmonary surfactant (APS) was prepared. The results of prevention of ARDS in ARDS rats showed that APS reduced the mortality of animal model significantly (from 46.47% to 16.17%) and the ratio of wet/dry lung weight (from 5.55 to 4.84). The surface properties of lung lavage of treated animals were improved effectively [balancing surface tension from 61.86 mN.m-1 to 47.02 mN.m-1, (normal 43.94 mN.m-1), minimal surface tension from 30.41 mN.m-1 to 7.16 mN.m-1(normal 3.49 mN.m-1)]. These results indicate that the APS preparation showed better effect on prevention of ARDS in rats.

[Artificial reconstituted pulmonary surfactant used for prevention and treatment of adult respiratory distress syndrome. II. Bioluminescence method for optimizing formulation]

Based on optimizing the formulations of artificial reconstituted pulmonary surfactant (APS) used for the prevention and treatment of adult respiratory distress syndrome (ARDS) by a surface chemical method, a quartz lung animal model to obtain active alveolar macrophages (AMs) was established, using a bioluminescence technique to optimize APS's formulation according to the free-radical-scavenging abilities of APS. An optimal formulation was obtained, which showed good surface properties and free-radical-scavenging abilities. The APS preparation will be used in ARDS animal model test.

Artificial reconstituted pulmonary surfactant in prevention and treatment of respiratory distress syndrome in neonates

AIM

To test an artificial reconstituted pulmonary surfactant (APS) for prevention and treatment of respiratory distress syndrome (RDS).

METHODS

A membrane-formed method combined with supersonic dispersing was used to prepare APS. A pulsating bubble surface tension measurement was established to compare surface properties of APS with natural pulmonary surfactant (NPS). A preliminary clinical trial was made for prevention and treatment of RDS.

RESULTS

The APS reduced surface tension from 44.0 mN/m to < 1.0 mN/m in vitro. The changes of APS lipid contents were < 5% of labeled content at 37 degrees C. Clinical trial showed that the APS prevented RDS in 20/20 and cured RDS in 2/2 premature neonates.

CONCLUSION

The APS had good surface properties similar to NPS.

[The establishment of human anti-tetanus toxoid hybridomas with in vitro immunized human tonsil cells]

Human tonsil cells in vitro immunized with tetanus toxoid were fused with human-mouse heteromyeloma line RF to generate human-mouse hybridomas. Hybridoma 891112-50 was cloned and 2 subclones (891112-50-3 and -4) were obtained. The secreted antibodies from the subclones were antigen specific, since they did not cross react with three irrelevant antigens (OVA, TCS and F gamma G). The hybridomas were quite stable. After 13 passages in tissue culture flasks, they still retained their antibody secreting ability. From flow cytometry analysis the subclone 50-3 was more stable than the subclone 50-4. The human immunoglobulin contained in supernatant collected during regular passages was equivalent to 69.6 micrograms/ml.

[Quantitative evaluation of the stability of antibody production by human-mouse hybridoma clones with flow cytometry analysis]

The paper described a method of quantitative stability analysis of antibody production by hybridoma clones with flow cytometry (FACS). Through FACS analysis the frequency of antibody-negative variants was measured. The rate of generation of antibody-negative variants/cell/generation (mu) could be calculated through Luria-Delbrück fluctuation analysis. The results showed that the value of mu was correlated to the antibody production of hybridoma clones: the larger was the mu value, the more unstable was the antibody production by the hybridoma clones. The experimental results suggested that the clone was stable if its mu value was on the magnitude of 10(-3), while the clone was not stable if its mu value was on the magnitude of 10(-2). According to requirements of single cell for FACS analysis and presence of a variety of methods for dispersing cell aggregates to single cells, the authors regard that this method is fully suitable for analysis of cells in suspension or even in the form of aggregate.

Central nervous system congenital malformations, especially neural tube defects in 29 provinces, metropolitan cities and autonomous regions of China: Chinese Birth Defects Monitoring Program

Data from the Chinese Birth Defects Monitoring Program (CBDMP) over the period of October 1986 to September 1987 were analysed to study the descriptive epidemiology of congenital malformations of the central nervous system (CNS), especially neural tube defects (NTDs) in China. A total of 4628 CNS congenital malformations were recorded within seven days of delivery among 1,243,284 live and stillbirths of 28 or more weeks gestation in 945 hospitals from all 29 provinces, metropolitan cities and autonomous regions of China. Neural tube defects account for 73.55% of these cases, hydrocephaly for 24.63% and microcephaly for 1.82%. The prevalence rates at birth of NTDs and congenital malformations of the CNS in China were 27.37 and 37.22 per 10,000 respectively. More NTDs were observed in females (35.68 per 10,000 female births) as compared to males (19.23 per 10,000 male births). The prevalence of NTDs in rural areas (51.69 per 10,000 births) was higher than that in urban areas (15.45 per 10,000 births).

[Comparative study of outer envelope protein and LPS of five strains of leptospires by SDS-PAGE and 2D-PAGE]

We applied SDS-PAGE, 2D-PAGE and Western blot to analyse the outer envelopes protein and LPS of five strains of leptospires. The work would lay foundations for taxonomy, the development of vaccination regimens and the elucidation of pathogenic mechanisms. The outer envelope proteins of leptospires were analyzed by SDS-PAGE and silver staining. We found that the protein profiles of the pathogenic leptospires were basically identical. A comparison of the protein profiles of the pathogenic L. with those exhibited by two nonpathogenic L. indicated that there was no obvious relationship between these organisms and any of the L. interrogans strains examined. The quantity of 21.5 kd protein of strain 017 was greater than that of strain 601 and 156. Approximately 200, 225, 238 distinct polypeptides were detected in the strain 017, 601 and 156 in 2D-PAGE by silver staining respectively. The profiles of 2D-PAGe showed obvious differences in pI. The pI of strain 017, 601 and 156 were mainly 6.68-7.4, 6.55-6.9, 5.85-7.1 respectively. The 21.5 kd protein of strain 017 was made up of six polypeptides. Our immunoblots revealed that McAb (LB1) reacted with a 41 kd antigen, which was common to the three virulent leptospires tested. SDS-PAGE profiles of silver stained outer envelope LPS of pathogenic L. differed greatly from those of the nonpathogenic L. There was a distinct differences between strain Patoc I and 3055. Our studies showed that each of the five strains of leptospires possessed characteristic outer envelope LPS, which may be used to identify the genus, species and serovars of a strain of L.

[In vitro assessment of candidacidal activity of human leukocyte myeloperoxidase preparation]

Myeloperoxidase (MPO), present in the azurophilic granules of human polymorphonuclear neutrophils, is important in the oxygen-dependent microbicidal activity of neutrophils. The purpose of our study was to investigate the therapeutic potency of the MPO preparations. This paper is to present our primary work on MPO isolation and its microbicidal activity assay. White blood cells, isolated freshly from normal donors, were lysed with cetyltrimehylammonium bromide to liberate myeloperoxidase. The enzyme preparation was partially purified by 50% (NH4)2SO4 precipitation followed by 65% (NH4)2SO4 precipitation. A hundred million leukocytes yielded 1.03 mg protein of the MPO preparation with the RZ of 0.31. The specific activity of the MPO preparation was about 29.25 u/mg. When 0.672 units of the MPO preparation were incubated with about 10(7) clinical isolates of Candida albicans in the presence of 0.2 mmol/L H2O2 and 0.14 mol/L NaCl. It was detected that 95.58 +/- 0.64% of the organisms were killed in the methylene blue staining system.