Differential diagnosis of autism spectrum disorder and global developmental delay based on machine learning and Children Neuropsychological and Behavioral Scale / 中国当代儿科杂志

OBJECTIVES@#To investigate the efficacy and required indicators of Children Neuropsychological and Behavioral Scale-Revision 2016 (CNBS-R2016) in the differential diagnosis of autism spectrum disorder (ASD) and global developmental delay (GDD).@*METHODS@#A total of 277 children with ASD and 415 children with GDD, aged 18-48 months, were enrolled as subjects. CNBS-R2016 was used to assess the developmental levels of six domains, i.e., gross motor, fine motor, adaptive ability, language, social behavior, and warning behavior, and a total of 13 indicators on intelligence age and developmental quotient (DQ) were obtained as the input features. Five commonly used machine learning classifiers were used for training to calculate the classification accuracy, sensitivity, and specificity of each classifier.@*RESULTS@#DQ of warning behavior was selected as the first feature in all five classifiers, and the use of this indicator alone had a classification accuracy of 78.90%. When the DQ of warning behavior was used in combination with the intelligence age of warning behavior, gross motor, and language, it had the highest classification accuracy of 86.71%.@*CONCLUSIONS@#Machine learning combined with CNBS-R2016 can effectively distinguish children with ASD from those with GDD. The DQ of warning behavior plays an important role in machine learning, and its combination with other features can improve classification accuracy, providing a basis for the efficient and accurate differential diagnosis of ASD and GDD in clinical practice.

Clinical Characteristics of Recurrent-positive Coronavirus Disease 2019 after Curative Discharge: a retrospective analysis of 15 cases in Wuhan China

In China, the patients with previously negative RT-PCR results again test positive during the post-discharge isolation period. We aimed to determine the clinical characteristics of these "recurrent-positive" patients. We retrospectively reviewed the data of 15 recurrent-positive patients and 107 control patients with non-recurrent, moderate COVID-19 treated in Wuhan, China. Clinical data and laboratory results were comparatively analyzed. We found that recurrent-positive patients had moderate disease. The rate of recurrent-positive disease in our hospital was 1.87%. Recurrent-positive patients were significantly younger (43(35-54) years) than control patients (60(43-69) years) (P=0.011). The early LOS (length of stay in hospital before recurrence) was significantly longer in recurrent-positive patients (36(34-45) days) than in control patients (15(7-30) days) (P =0.001). The time required for the first conversion of RT-PCR results from positive to negative was significantly longer in recurrent-positive patients (14(10-17) days) than in control patients (6(3-9) days) (P =0.011). Serum COVID-19 antibody levels were significantly lower in recurrent-positive patients than in control patients (IgM: 13.69 {+/-} 4.38 vs. 68.10 {+/-} 20.85 AU/mL, P = 0.015; IgG: 78.53 {+/-} 9.30 vs. 147.85 {+/-} 13.33 AU/mL, P < 0.0001). Recurrent-positive patients were younger than control patients. The early LOS (length of stay in hospital before recurrence) was significantly longer in recurrent-positive group than that in control group. COVID-19 IgM/IgG antibody levels were significantly lower in recurrent-positive group than those in control group, which might explain why the virus RNA RT-PCR was positive after the initial "clinical cure"(with three times of virus RNA RT-PCR negative). The virus might not be fully eliminated because of the lower IgG level and their later replicating might result in recurrent-positive virus RNA RT-PCR.

Efficacy and safety of chloroquine or hydroxychloroquine in moderate type of COVID-19: a prospective open-label randomized controlled study

The outbreak of novel coronavirus disease 2019 (COVID-19) has become a pandemic. Drug repurposing may represent a rapid way to fill the urgent need for effective treatment. We evaluated the clinical utility of chloroquine and hydroxychloroquine in treating COVID-19. Forty-eight patients with moderate COVID-19 were randomized to oral treatment with chloroquine (1000 mg QD on Day 1, then 500 mg QD for 9 days; n=18), hydroxychloroquine (200 mg BID for 10 days; n=18), or control treatment (n=12). Adverse events were mild, except for one case of Grade 2 ALT elevation. Adverse events were more commonly observed in the chloroquine group (44.44%) and the hydroxychloroquine group (50.00%) than in the control group (16.67%). The chloroquine group achieved shorter time to clinical recovery (TTCR) than the control group (P=0.019). There was a trend toward reduced TTCR in the hydroxychloroquine group (P=0.049). The time to reach viral RNA negativity was significantly faster in the chloroquine group and the hydroxychloroquine group than in the control group (P=0.006 and P=0.010, respectively). The median numbers of days to reach RNA negativity in the chloroquine, hydroxychloroquine, and control groups was 2.5 (IQR: 2.0-3.8) days, 2.0 (IQR: 2.0-3.5) days, and 7.0 (IQR: 3.0-10.0) days, respectively. The chloroquine and hydroxychloroquine groups also showed trends toward improvement in the duration of hospitalization and findings on lung computerized tomography (CT). This study provides evidence that (hydroxy)chloroquine may be used effectively in treating moderate COVID-19 and supports larger trials.

Sexual behavior characteristics and influencing factors of gonorrhea patients in Yunnan Province / 中华疾病控制杂志

Objective To investigate the sexual behavior types, condom use and influencing factors of gonorrhea patients in Yunnan Province, and to provide evidence for the adjustment of sexually transmitted disease (STD) prevention and control strategy. Methods A cross-sectional study was carried out to investigate gonorrhea patients in 14 STD clinics in 7 more prevalent prefectures (cities) of Yunnan Province. A questionnaire survey was conducted to investigate the socio-demographic and sexual characteristics of the patients in a one-to-one way. Multiple Logistic regression model was used to analyze the influencing factors of sexual behavior. Results A total of 179 cases of gonorrhea were investigated. The average age was (29.01±8.93) years old. 95.53% (171/179) patients were 40 years old and 88.27% were male patients (158/179). Unmarried patients accounted for 55.31% (99/179). Service and self-employed patients accounted for 34.64% (62/179) and 23.46% (42/179) respectively. The rate of sexual intercourse with opposite sex was 98.32% (176/179), the rate of men who have sex with men was 1.68% (3/179) and the rate of having more than two sexual partners was 27.93% (50/179). The rate of sexual intercourse between temporary partners, spouses/fixed partners and commercial partners were 53.07% (95/179), 37.99% (68/179) and 8.94% (16/179) respectively. Recent sexual activity had lower condom use rate, 17.89% (17/95), 19.12% (13/68) and 18.75% (3/16) respectively. The main ways for gonorrhea patients to make temporary partners were friend introductions or gatherings, accounting for 66.32% (63/95). Condom use in male patients was worse than that in female patients (OR=0.234, 95% CI: 0.084-0.656, P=0.006). Conclusions The patients with gonorrhea were mainly unmarried young adults. The main risk behaviors were unprotected behaviors between heterosexual temporary and spouse/fixed sexual partners. The condom use consciousness was generally low. The promotion of safe sex education for young adults should be further strengthened, with special attention to the use of condoms for temporary sexual behavior and spouse/fixed sexual intercourse.

Increased expressions of leptin and its receptor in the epididymis of varicocele model rats and their implications / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the expressions of leptin and its receptor in the epididymis of experimental varicocele (EV) rats.</p><p><b>METHODS</b>Forty male Sprague-Dawley rats were randomly divided into four groups: 4-week EV (n = 12), 8-week EV (n = 12), 4-week control (n = 8), and 8-week control (n = 8). EV models were established by partial ligation of the left renal vein. The expressions of leptin and its receptor in the rat epididymis were measured by immunohistochemistry, and their mRNA expressions determined by real-time quantitative PCR.</p><p><b>RESULTS</b>The expressions of leptin and its receptor in the epididymis were significantly higher in the 4- and 8-week EV groups than in the 4- and 8-week control groups (P < 0.01), with no significant difference between the two EV groups (P > 0.05). So were their mRNA expressions in the former two than in the latter two groups (P < 0.01), with no significant difference between the former two (P > 0.05).</p><p><b>CONCLUSION</b>The expressions of leptin and its receptor are markedly increased in the epididymis of varicocele rats. Leptin may be involved in the mechanisms of varicocele inducing male infertility.</p>

Expression of Eag1 K(+) channel in prostate cancer and its significance / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the expression of the Eag1 K( +) channel in the prostate cancer (PCa) tissue, its correlation with the development and progression of PCa, and whether it could be a target for the diagnosis and treatment of PCa.</p><p><b>METHODS</b>We used RT-PCR and immunohistochemistry to determine the mRNA and protein expressions of the Eag1 K(+) channel in the normal peritumoral tissue of androgen-dependent PCa (ADPCa) (group A) and androgen-independent PCa (AIPCa) (group B) as well as in the tumorous tissue of ADPCa (group C) and AIPCa (group D).</p><p><b>RESULTS</b>The relative coefficients of the mRNA expression of the Eag1 K(+) channel were 0.265 +/- 0.413, 0.167 +/- 0.511, 2.673 +/- 2.988 and 2.815 +/- 2.901 in groups A, B, C and D, respectively, increased significantly in the latter two groups (P < 0.05). The positive rates of the protein expression of the Eag1 K (+) channel were significantly higher in groups C (88.9%) and D (86.7%) than in A (7.4%) and B (6.7%) (P < 0.05).</p><p><b>CONCLUSION</b>The Eag1 K(+) channel might be involved in the pathophysiological processes of PCa, and is expected to be a valuable target for the diagnosis and treatment of PCa.</p>

Clinical study of different bowel preparations on changes of gut flora in patients undergoing colorectal resection / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare the impact of traditional and fast bowel preparation on the changes of gut flora in the patients following colorectal resection.</p><p><b>METHODS</b>Sixty patients undergoing colorectal resection from March 2010 to March 2011 in the Nanfang Hospital were randomly divided into the control group(n=27, 3 days of bowel preparation) and the experimental group(n=33, 1 day of bowel preparation). Fresh feces were collected before bowel preparation and on the first defecation after surgery. The postoperative changes in gut flora and septic complications were observed.</p><p><b>RESULTS</b>Gut flora disturbance was found in both groups. The postoperative population of Bifidobacterium and Lactobacillus decreased significantly(P<0.05), and the decrease was more significant in the experimental group compared to the control group(P<0.05), while E.coli and Staphylococcus were much higher than the preoperative level(P<0.05), which was more significant in the control group. The incidence of postoperative infection was 9.1%(3/33) in the experimental group, which was significantly lower than 29.6%(8/27) in the control group(P<0.05).</p><p><b>CONCLUSION</b>Fast bowel preparation is effective in reducing gut flora disturbance and the incidence of postoperative infection.</p>

Concealed penis affects the morphology of the corpus cavernosum in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the influence of concealed penis on the morphology of the corpus cavernosum in rats.</p><p><b>METHODS</b>Rat models of concealed penis were established by intra-pocket-suture of the root of the penis. Fifty rats were equally assigned to Groups A (2-month) and B (4-month), each further divided into a buried (n = 15) and a normal subgroup (n = 10). Changes in the morphology of the penile cavernous tissue were observed under the light microscope and transmission electron microscope.</p><p><b>RESULTS</b>Compared with Group A, Group B showed significant ultra-structural pathological changes in the corpus cavernosum, including abnormal arrangement of endothelial and smooth muscle cells, massive hyperplasia of interstitial tissues, narrowed cavernous sinus, atrophic smooth muscle cells, degenerated mitochondria, dilated endoplasmic reticula, decreased dense bodies and contractile fibers, and cytoplasmic vacuolization. No significant differences were found in the appearance and weight of the corpus cavernosum between the buried and normal groups (P > 0.05).</p><p><b>CONCLUSION</b>Concealed penis does not significantly affect the appearance and weight of the corpus cavernosum, but causes ultra-structural pathological changes in it with the lengthening of time.</p>

Effects of buried penis on the structure and function of corpus cavernosum in a rat model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>While the abnormal appearance of the concealed penis has been well recognized, the effect of buried penis on the structure and function of corpus cavernosum has not been well studied. To explore this issue, we established a rat model and evaluated the effect of buried penis on cavernosum weight, contents and ultrastructure of tissue, and nitric oxide synthase (NOS) activity.</p><p><b>METHODS</b>Two hundred and ten rats were randomly divided into 3 equal cohorts for 2, 4 and 6 months study (groups A, B and C). Each group was randomly divided into buried group (n = 40), control group (n = 15), and normal group (n = 15), respectively. Intra-purse-string suture of the root of the penis was used to establish the model. Macroscopic development was judged by measuring the weight of the corpus cavernosum. Masson's trichrome staining was performed for observing microstructure while a transmission electron microscope was used for observing ultrastructure. The NOS activity was detected by a NOS activity assay kit.</p><p><b>RESULTS</b>Buried penis had no significant influence on the appearance and weight of the corpus cavernosum. Buried penis resulted in decreased smooth muscle content (P > 0.05 in group A, and P < 0.05 in groups B and C) and increased fibrous connective tissue content (P > 0.05 in groups A and B, and P < 0.05 in group C) compared with the normal and control groups. Ultrastructural abnormalities of corpus cavernosum were observed in the 6-month buried group. Moreover, there was decrease of NOS activity in groups B and C (P < 0.05 in group B and P < 0.01 in group C) when compared with the normal and control groups.</p><p><b>CONCLUSION</b>Buried penis affects the structure and function of corpus cavernosum in rats and the effect is positively correlated with the buried time, but there is no significant effect on the macroscopic development.</p>

Preparation and clinical observation of Jiangya Wentie Pian / 中国针灸

<p><b>OBJECTIVE</b>To probe into an effective method for treatment of hypertension.</p><p><b>METHODS</b>Eighty cases of hypertension were treated with sticking Jiangya Wentie Plan at Shenque (CV 8) and Yongquan (KI 1) as main.</p><p><b>RESULTS</b>Forty-eight were markedly effective, 29 cases were effective, 3 cases were ineffective, with an total effective rate of 96.25%.</p><p><b>CONCLUSION</b>Acupoint sticking of Jiangya Wentie Plan has obvious therapeutic effect on hypertension.</p>

Experimental varicocele affects the ipsilateral testis in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the impact of experimental varicocele (EV) on the ipsilateral testis in rats.</p><p><b>METHODS</b>EV was induced by partial ligation of the left renal vein in male SD rats, the control rats subjected to sham operation, and the testes of the EV models and controls were extirpated 6, 12, and 18 weeks later. Johnson's score, ultrastructure of seminiferous tubules, intratesticular testosterone concentration (ITC) and germ cell apoptotic index (AI) of each left testis were evaluated.</p><p><b>RESULTS</b>Johnson's scores were (6.92 +/- 0.52), (4.83 +/- 0.41) and (2.95 +/- 0.26), ITCswere (6.32 +/- 0.85), (5.17 +/- 0.76) and (4.11 +/- 0.69) and AIs were (5.32 +/- 1.23), (15.21 +/- 0.97) and (21.13 +/- 1.12) respectively in the 6 w , 12 w and 18 w EV groups, significantly lower than in the corresponding control groups, (9.56 +/- 0.35, 9.63 +/- 0.31, 9.39 +/- 0.46), (9.64 +/- 1.23, 9.38 +/- 0.69, 9.73 +/- 0.49) and (3.21 +/- 1.15, 3.43 +/- 1.21, 3.61 +/- 1. 15) (P < 0.05), the former two showing a gradual decline while the latter a significant elevation with the increasing duration of varicocele. The damage to the ultrastructure of seminiferous tubules was aggravated with the prolonging of varicocele.</p><p><b>CONCLUSION</b>EV can cause a progressive decline of ITC, dyszoospermia and increased AI of germ cells.</p>

Buried penis decreases nitric oxide synthase of the corpus cavernosum / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the influence of buried penis on nitric oxide synthase (NOS) activity of the corpus cavernosum in rats.</p><p><b>METHODS</b>The experimental model of concealed penis was established by intra-pocket-suture of the root of the penis. Two hundred and forty rats were equally randomized into a 2, a 4 and a 6 months group, each further divided into a buried (n = 50), a sham operation (n = 15) and a normal subgroup (n = 15). The development of the corpus cavernosum was surveyed by measuring its weight and the ratio to the body weight, followed by determination of NOS activity in the corpus cavernosum by spectrophotometry.</p><p><b>RESULTS</b>No significant differences were found in the corpus cavernosum weight, the body weight and their ratio among the buried, sham operation and normal groups in any experimental stage (P > 0.05). Buried penis decreased NOS activity in the 4- and 6-month groups (P < 0.05 and P < 0.01) compared with the normal group, but effected no significant change in the 2-month group.</p><p><b>CONCLUSION</b>Buried penis decreases the NOS activity of the corpus cavernosum in a positively time-related manner, but with no significant influence on its appearance and weight.</p>

Two ways of constructing concealed penis model in rats: a comparative and analytical study / 中华男科学杂志

<p><b>OBJECTIVE</b>To establish a stable rat experimental model of concealed penis for studying the effect of buried penis on the structure and function of the corpus cavernosum.</p><p><b>METHODS</b>Ninety male SD rats, aged 2 weeks, were randomly divided into 3 groups (A, B and C) of equal number. Groups A and B underwent surgery with intra-purse suture of the penile root and folding suture of the prepuce, respectively, to bury the penis, while Group C were included as sham operation controls.</p><p><b>RESULTS</b>In Group A, death resulted in 4 cases from acute post-operative urine retention, failure in burying the penis occurred in 5 cases because of soft tissue ulceration around the urethral orifice and in another 3 due to loose concealment. In Group B, 1 died from deep anesthesia and 2 from acute post-operative urine retention. With the penile development and erection, 7 in Group A and 10 in Group B protruded the penis in different stages. In Group C, 1 died from deep anesthesia. The operations succeeded in all the other rats in Groups A and B, with the success rates of 36.7% and 56.7%, respectively. And the concealment could be relieved any time during the experiment.</p><p><b>CONCLUSION</b>The experimental rat model of concealed penis can be successfully established by both intra-purse suture of the penile root and folding suture of the prepuce, which is stable and similar to the natural course of this disorder in human.</p>

Progress in pharmacotherapy of female sexual dysfunction / 中华男科学杂志

Recent years have seen great progress in the researches on the pharmacotherapy of female sexual dysfunction( FSD). Estrogen replacement therapy is effective on female sexual pain and dyspareunia; androgen can improve female hyposexuality; and a variety of drugs and medication forms are being studied for their efficacy on FSD, including the 5-phosphodiesterase inhibitor, dopamine receptor stimulant, prostaglandin E1, adrenergic receptor blocker, some traditional Chinese medicine, and so on, which have yielded lots of inspiring findings.

Effects of injection of Huangqi injectio into Zusanli (ST 36) on immune function in the patient of schizophrenia / 中国针灸

<p><b>OBJECTIVE</b>To study on effects of injection of Huangqi Injectio into Zusanli (ST 36) on the hospital infection and immune function in the patient of schizophrenia.</p><p><b>METHODS</b>Thirty inpatients of chronic schizophrenia were treated with injection of Huangqi Injectio into bilateral Zusanli (ST 36), 2 mL each point, thrice each week, for 8 weeks. Relative immune indexes and the hospital infection were investigated.</p><p><b>RESULTS</b>The hospital infection and the sub-infection were 4 cases (13.3%), 7 cases-times (23.3%) in the injection group; and 9 cases (15.0%), 19 cases-times (31.7%) in the control group, respectively, with no significant difference between the two groups (P>0.05). The drug-administration duration was 7.77 days/case and 11.87 days/case in the two groups, respectively (P<0.01). In the injection group, as compared with that of last 3 years the duration was 7.77 days/case and 14.08 days/case (P<0.01). IgG, IgA, IgM and T-cell subgroups did not have significant changes, but there was the most different value before and after injection in SIL-2R of the no-infection group, and the longer the drug administration duration, the smaller the different values.</p><p><b>CONCLUSION</b>Injection of Huangqi Injectio into Zusanli (ST 36) has definite effect for prevention of the hospital infection in inpatients of chronic schizophrenia, and SIL-2R is a valuable index for investigation of the hospital of infection.</p>

Proteomics technology for screening biomarkers of oligospermic candidates / 中华男科学杂志

<p><b>OBJECTIVE</b>To screening specific biomarkers of oligospermic candidates from seminal plasma by proteomics technology.</p><p><b>METHODS</b>The protein spectra of 20 seminal plasma from oligospermic patients and healthy male individuals were analyzed by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) to compare different protein expressions.</p><p><b>RESULTS</b>Compared with normal control group, a specific protein peak of molecular weight 11 022.9 in the protein spectra of oligospermic patients'semen on H4 protein-chip reduced significantly, but the protein peak of molecular weight 11 507.4 elevated apparently. For SAX-2 protein-chip, a specific protein peak of molecular weight 16 751.6 in the protein spectra of oligospermic patients' semen elevated significantly.</p><p><b>CONCLUSION</b>Screening specific proteins in seminal plasma of oligospermic patients is important for understanding the mechanism of oligospermia and screening suspected oligospermic individuals.</p>

Hydrogenation properties of mechanically milled Mg2Ni0.8Cr0.2-CoO/Al2O3 composites / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Mg2Ni0.8Cr0.2-x wt.% CoO/Al2O3 (x=0.5, 1, 2 and 3) composites were prepared by mechanically milling sintered Mg2Ni0.8Cr0.2 alloy and CoO/Al2O3 compound for 45 h. The addition of CoO/Al2O3 compound resulted in the good kinetics properties of hydriding/dehydriding reaction of the composites. The composite with 1.0 wt.% CoO/Al2O3 catalyst could reach the maximum hydrogen absorption capacity (2.9 wt.%) within 5 min at 393 K under H2 pressure of 4 MPa, and can desorb rapidly at 493 K. The decomposition and synthesis of hydrogen molecule on Mg2Ni0.8Cr0.2 alloy surface was promoted by addition of CoO/Al2O3 catalyst. In addition, the formation of metallic Ni particles, strain and defects during the ball milling process also resulted in the improved hydrogenation performance of Mg2Ni-based alloys.

Influence of estradiol benzoate on the testis development of rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the influence of estradiol benzoate (E2B) on the testis development of Sprague-Dawley (SD) rats.</p><p><b>METHODS</b>Newborn male SD rats were injected subcutaneously with E2B (0.2 mg/5 g body weight). At days 14, 21, 28, 42 and 56 after birth, the rats were sacrificed after anaesthesia, and their testes were taken out and weighed. The cranial and caudal SEH and TD were measured respectively, the TD/SEH ratio in each part of the testis and the caudal SEH/cranial SEH ratio were calculated, and different stages of spermatogenesis were analysed.</p><p><b>RESULTS</b>In the experimental group, the testis weight was significantly lower than that of the control (P < 0.01), the testes constantly remained in the abdominal cavity, and there was much fluid retention in the rete testis all the time. From day 21 on, the TD/SEH ratio in the cranial testis was much higher than in the control (P < 0.01), and so was the caudal SEH/cranial SEH ratio (P < 0.01). And spermatogenesis was obviously retarded as compared with the control (P < 0.01).</p><p><b>CONCLUSION</b>Exposure of newborn male SD rats to E2B can cause fluid retention in the testis and cryptorchid, which in turn may retard spermatogenesis.</p>

Influence of estradiol benzoate on fluid reabsorption capacity of rat efferent ductuli / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the influence of estradiol benzoate (E2B) on the fluid reabsorption capacity of rat efferent ductuli.</p><p><b>METHODS</b>Newborn male Sprague-Dawley rats were injected subcutaneously with E2B (0.2 mg/5 g body weight), and the histological morphology of efferent ductulus, epithelial ultrastructure, and immunoexpression of AQP-1 were investigated on postnatal day 14, 21, 28, 42 and 56, respectively. Vehicle was given to the controls.</p><p><b>RESULTS</b>After exposure to E2B, the lumina of the efferent ductuli dilated greatly (P < 0.05), and the epithelium height decreased significantly (P < 0.01), microvilli of nonciliated cells short and sparse, endocytic apparatus implicated in fluid reabsorption scarce, and with no AQP-1 expression.</p><p><b>CONCLUSION</b>High dosage of E2 B neonatally administrated to rats damages the fluid reabsorption capacity of efferent ductuli.</p>

Effects of veratryl alcohol and tween 80 on ligninase production and its roles in decolorization of azo dyes by white-rot basidiomycete PM2 / 生物工程学报

Basidiomycete PM2, a lignin-degrading white rot fungus, produces lgnin peroxidase (Lip) and manganese peroxidase (Mnp) in nutrient nitrogen limited liquid cultures. This fungus was selected for its ability to decolorize azo group of dyes. In order to improve production of the peroxidases and rapid dye decolorizing activity by basidiomycete PM2, the addition of veratryl alcohol or Tween 80 to nutrient nitrogen limited liquid cultures were tested. It was found to have a large stimulatory effect on Mnp activities and decolorization rate of azo dyes. A maximum Mnp activities of 254.2 u/L with veratryl alcohol and 192.2 u/L with Tween 80 were achieved respectively. These values were about 3.4-fold and 2.5-fold higher than that obtained in the control cultures (without alcohol or Tween 80), whereas the levels of Lip activity detected were very low (about 12 u/L)in all the cultures. In further experiments using three kinds of azo dyes of congo red, orange G and orange IV, enzyme activities and dye decolorization were investigated in the above-mentioned cultures. The results showed that Mnp activities and decolorization were notably higher than those obtained in the control cultures in the presence of azo dyes. Cultures supplemented with Tween 80 were more adequate for dye decolorization. The rates of the decolorization with Tween 80 of congo red (95.4%), orange G (98.5%) and orange IV (54.4%) after 24 hours of dye incubation were higher than that supplemented with veratryl alcohol. According to the results, Mnp activities secreted by basidiomycete PM2 play an essential role in the process of dye decolorization. Tween 80 was the main factor affecting the decolorization. The analysis of structure of the three kinds of azo dyes indicats that the extent of decolorization is affected by the dye molecular structure. The types and quantity of the substituted groups on the aromatic ring of azo dyes have effect on the percentage of biological decolorization.