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In order to solve the problem of insufficient vulcanization of the molding silicone rubber used in automobile interior decoration, a certain amount of tri-(2,4-bis-tert-butyl phenyl) phosphite (A) and triphenyl phosphate ester (B) were added into RTV-2 (two-component room temperature vulcanized) liquid silicone rubber. The influence of different valence state phosphorus (P) on the vulcanization behavior of silicone rubber and the critical content of P for platinum catalyst poisoning were studied. The results show that the main reason which causing the non-vulcanization of silicone rubber in the polyvinyl chloride (PVC) skin is because of the unsaturated P element. The shared electron pairs on the orbit of the unsaturated phosphorus element will combine with platinum, causing an irreversible reaction, and lead to the poisoning of the platinum catalyst, resulting in the incomplete vulcanization of RTV -2 silicone rubber. In the practical production, it is necessary to ensure that the content of unsaturated P element in PVC skin is less than the critical value which causes platinum element poisoning in platinum catalyst, and the RTV -2 silicone rubber can be completely vulcanized to replicate clear PVC skin pattern. [ABSTRACT FROM AUTHOR]

The effect of amount of platinum catalyst on the curying behaviour of tow - component room temperature vulcanization (RTV_2) liquid silicone rubber on the surface of polyvinyl chloride (PVC) was studied by rheological method. The problem of silicone rubber poisoning and low pattern reproduction rate caused by the reaction between silicone rubber and the material in PVC epidermis durning preparing the slush mould was solved by adjusting the amount of platinum catalyst in siliconer rubber. The experimental results show that after adding the extra 0.5% -1. 0% platinum catalyst, silicone rubber is completely cured on the surface of PVC and form clear patterns on it. [ABSTRACT FROM AUTHOR]

Based on the annual investigation data of biological resources in Lidao artificial reef zone in 2009, an Ecopath model of the Lidao artificial reef ecosystem was constructed to analyze the energy flow pattern and the system attributes of the ecosystem. The model was consisted of 19 functional groups, basically covering the main processes of the energy flow in the Lidao artificial reef ecosystem. The functional groups were divided according to the relationships of the corresponding positions between appeared fishes and artificial reefs, and the planktonic heterotrophic bacteria were included into the model as a functional group. The fishes appeared in the investigation zone were divided into seven functional groups, and the trophic levels of the functional groups varied from 1. 00 to 3. 72. The type I fishes had the highest trophic level. The total system throughput was estimated to be 10786. 68 t · km-2 · a-1, 27% of which flowed to detritus, and 17% flowed out the ecosystem in the forms of fishing and sediment. The total net primary productivity of the system was 4131.97 t · km-2 a-1, and the total energy transfer efficiency was 10. 5%. The proportion of the total flow originated from detritus was 39%, and that from primary producers was 61%, indicating that the energy flow was dominated by food web rather than detritus. The ratio of total primary productivity to total respiration of the system was 1. 84, the connectivity index was 0. 20, and the Finn's cycling index and the mean path length of the energy flow were 4. 5% and 2. 62, respectively. This study showed that the Lidao artificial reef ecosystem had a relatively low maturity and stability, was at a developing stage, and had weak resistance against outside interference. The ecological environment and the output of fisheries in the artificial reef zone would have inter-annual fluctuations, and thus, the eco-environment restoration of the artificial reef ecosystem could only be realized by the sustainable maintaining of the ecosystem. [ABSTRACT FROM AUTHOR]

Objective: To observe the effects of Tiaoshen (regulating the spirit) acupuncture on cognitive function and sleep quality in patients with primary insomnia (PI)., Methods: Sixty patients with PI were randomly divided into an observation group (30 cases, 2 cases dropped off) and a control group (30 cases, 2 cases dropped off, 1 case was excluded). The patients in the observation group were treated with acupuncture at Baihui (GV 20), Shenting (GV 24), Sishencong (EX-HN 1), and bilateral Benshen (GB 13), Shenmen (HT 7), Neiguan (PC 6), Sanyinjiao (SP 6). The patients in the control group were treated with shallow needling at non-effective points. Each treatment was provided for 30 min, once every other day, 3 treatments per week for 4 weeks. The Montreal cognitive assessment (MoCA), digit span test (DST), trail making test (TMT)-A, Pittsburgh sleep quality index (PSQI), and fatigue scale-14 (FS-14) were used to assess cognitive function and sleep quality before and after treatment, as well as in follow-up of 4-week after treatment completion. Correlation analysis was conducted between the differences in PSQI scores and differences in MoCA scores before and after treatment in the observation group., Results: Compared with before treatment, the total score, visuospatial and executive function score and delayed memory score of MoCA as well as DST backward score were increased ( P <0.01), while TMT-A time, PSQI and FS-14 scores were significantly reduced ( P <0.01) after treatment and in follow-up in the observation group. Compared with before treatment, the PSQI score in the control group was reduced ( P <0.01, P <0.05). After treatment and in follow-up, the observation group had significantly higher total score, visuospatial and executive function score, delayed memory score of MoCA, and DST backward score compared to the control group ( P <0.05, P <0.01). In the observation group, the TMT-A time was significantly shorter than that in the control group ( P <0.05, P <0.01), and the PSQI and FS-14 scores were significantly lower than those in the control group ( P <0.01). In the observation group, there was a negative correlation between the difference in PSQI scores (post-treatment minus pre-treatment) and the difference in MoCA scores (post-treatment minus pre-treatment) ( r =-0.481, P <0.01). A similar negative correlation was found between the difference in PSQI scores (follow-up minus pre-treatment) and the difference in MoCA scores (follow-up minus pre-treatment) ( r =-0.282, P <0.05)., Conclusion: Tiaoshen acupuncture could improve cognitive function, enhance sleep quality, and alleviate daytime fatigue in patients with PI. The improvement in cognitive function in patients with PI is correlated with the improvement in sleep quality.

Objective: To investigate the influence of hypomagnesemia on the prognosis of patients with severe sepsis., Methods: A retrospective study was conducted. The clinical data of 207 septic patients admitted to the department of critical care medicine of the First Affiliated Hospital of University of Science and Technology of China from January 1, 2016 to December 21, 2020 were analyzed, including gender, age and laboratory indicators within 24 hours after sepsis diagnosis [procalcitonin (PCT), C-reactive protein (CRP), blood lactic acid (Lac), pH value and blood magnesium, calcium, chlorine and phosphorus levels]. The acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score and 28-day prognosis were collected. The patients were divided into survival group and non-survival group according to the prognosis, and the clinical data and laboratory indexes were compared between the two groups. Pearson correlation test was used to analyze the correlation between clinical indicators. Multivariate Logistic regression analysis was used to screen the risk factors affecting the prognosis. The receiver operator characteristic curve (ROC curve) was drawn, and the area under ROC curve (AUC) was calculated to evaluate the potential prognostic indicators., Results: Among the 207 septic patients, 102 survived and 105 died on the 28th day, and the 28-day mortality was 50.72%. There were no significant differences in gender, age, CRP, pH value, blood chlorine or blood phosphorus levels between the two groups. The blood magnesium and blood calcium levels in the non-survival group were significantly lower than those in the survival group [blood magnesium (mmol/L): 0.68±0.14 vs. 0.80±0.12, blood calcium (mmol/L): 1.93±0.21 vs. 2.01±0.20, both P > 0.01], and PCT, Lac, APACHE II score and SOFA score were significantly higher than those in the survival group [PCT (mg/L): 8.32 (1.64, 55.01) vs. 3.55 (0.97, 12.31), Lac (mmol/L): 2.90 (1.70, 4.30) vs. 2.10 (1.03, 3.89), APACHE II score: 21.24±6.40 vs. 17.42±7.02, SOFA score: 9.14±3.55 vs. 6.91±3.31, all P > 0.01]. Among the 207 patients, 96 patients had normal blood magnesium level (0.75-1.25 mmol/L) and 111 patients had hypomagnesemia (> 0.75 mmol/L). The 28-day mortality of septic patients in the hypomagnesemia group was significantly higher than that in the normal magnesium group [61.26% (68/111) vs. 38.54% (37/96), P < 0.01]. Pearson correlation analysis showed that the blood magnesium level of sepsis patients was negatively correlated with PCT (r = -0.173, P < 0.05), and it was positively correlated with APACHE II score (r = 0.159, P < 0.05), but it had no correlation with CRP or SOFA score (r values were -0.029 and 0.091, both P > 0.05). Logistic regression analysis showed that serum magnesium, APACHE II score and SOFA score were independent risk factors for 28-day death in patients with sepsis [serum magnesium: odds ratio (OR) < 0.001, 95% confidence interval (95%CI) was 0.000-0.002, P < 0.001; APACHE II score: OR = 1.092, 95%CI was 1.022-1.168, P = 0.010; SOFA score: OR = 1.168, 95%CI was 1.026-1.330, P = 0.019]. ROC curve analysis showed that blood magnesium and APACHE II score had a certain predictive value for 28-day mortality in patients with severe sepsis [AUC (95%CI) was 0.723 (0.655-0.791) and 0.680 (0.607-0.754), respectively]. When the blood magnesium threshold was 0.64 mmol/L, the sensitivity was 41.0% and the specificity was 93.1%. When APACHE II score threshold was 16.50, the sensitivity was 78.1% and the specificity was 55.9% indicating that the specificity of serum magnesium was higher than that of APACHE II score., Conclusions: Severe septic patients complicated with hypomagnesemia have a poor prognosis. Serum magnesium level can be used as a prognostic indicator for severe septic patients.

A total of 22 antibiotics and 16 polycyclic aromatic hydrocarbons(PAHs) in sediments before and after desilting in typical areas(fish ponds and open water) of Baiyangdian Lake were analyzed using HPLC-MS/MS and GC/MS(high performance liquid chromatography and gas chromatography coupled with mass spectrometry), to evaluate their potentially risks to the ecological environment. The results showed that the contents of 22 antibiotics in Baiyangdian Lake sediments ranged from 0 to 52.89 ng·g -1 , in which the quinolones content was the highest. After dredging treatment, the average content of antibiotics in Nanliuzhuang open water area decreased from 46.25 ng·g -1 to 9 ng·g -1 (80.54% reduction), while the average content of antibiotic(19.07 ng·g -1 ) in Caiputai remained relatively stable. Therefore, the dredging treatment performed better in removing antibiotics from Naliuzhuang area. The total contents of 16 PAHs in sediments ranged from 23.79 ng·g -1 to 329.40 ng·g -1 , in which Naphthalene was the highest(242.02 ng·g -1 ), while Fluoranthene was the lowest. The average content of PAHs in sediments in Nanliuzhuang decreased from 117.45 ng·g -1 to 50.49 ng·g -1 after dredging, while PAHs in Caiputai(57.98 ng·g -1 ) remained stable; the 57.01% reduction in PAHs in Nanliuzhuang open water indicated that dredging treatment exhibited stronger effects on PAHs variations in Nanliuzhuang compared to that of Caiputai. In addition, the ecological risk assessment showed that the risk of Enrofloxacin and Norfloxacin was high in area S2 of Nanliuzhuang open water, while PAHs exhibited relatively low ecological risk, in which the Naphthalene in area S1 of Fuhe river posed medium ecological risk while the remaining produced low ecological risks. The results indicated that quinolone antibiotics in sediments of the un-dredged area of Baiyangdian Lake should be monitored due to its higher ecological risk.

Objective: To investigate the clinical significance of neutrophil-to-lymphocyte ratio (NLR) in classification of patients with coronavirus disease 2019 (COVID-19)., Methods: A retrospective analysis was performed on 72 patients with COVID-19 admitted to the critical ward of Cancer Center of Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology in Wuhan from February to March in 2020. The patients were divided into two groups: moderate type (non-severe group) and severe/critical type (severe group). The results of white blood cell count (WBC), neutrophil count (NEU), lymphocyte count (LYM), interleukin-6 (IL-6) and D-dimer were collected at the 2nd day after admission from the two groups, and the NLR was calculated. The diagnostic value of WBC, NEU, LYM, IL-6, D-dimer and NLR on COVID-19 classification was evaluated by the receiver operating characteristic (ROC) curve., Results: A total of 72 COVID-19 patients were enrolled, among whom 52 were moderate, 17 were severe, and 3 were critical. The most common clinical manifestations of patients were fever (70.8%), cough (36.1%), chest tightness and breathlessness (37.5%), diarrhea (15.3%), fatigue (15.3%), vomiting and nausea (11.1%), occasionally accompanied by acute dyspnea (2.8%), and only one patient had no clinical symptom (1.4%). The levels of WBC, NEU, IL-6, D-dimer and NLR in the severe group were significantly higher than those in the non-severe group [WBC (×10 9 /L): 7.81±3.65 vs. 5.34±1.69, NEU (×10 9 /L): 5.83±3.13 vs. 3.24±1.53, IL-6 (ng/L): 133.63 (71.09, 249.61) vs. 28.05 (6.41, 101.24), D-dimer (mg/L): 0.86 (0.31, 2.56) vs. 0.33 (0.20, 0.71), NLR: 6.14±4.75 vs. 2.66±1.93, all P < 0.05], and the level of LYM was significantly lower than that in the non-severe group (×10 9 /L: 1.09±0.56 vs. 1.49±0.74, P < 0.05). The results of ROC curve analysis showed that the areas under ROC curve (AUC) of WBC, NEU, LYM, IL-6, D-dimer and NLR for COVID-19 classification were 0.790 [95% confidence interval (95%CI) was 0.684-0.897), 0.869 (95%CI was 0.789-0.949), 0.719 (95%CI was 0.592-0.847), 0.790 (95%CI was 0.682-0.898), 0.676 (95%CI was 0.526-0.827), and 0.888 (95%CI was 0.814-0.963) respectively. The AUC of NLR was the highest, which was of high diagnostic value; when the optimum cut-off value of NLR was 3.00, the sensitivity was 100%, and the specificity was 73.1%., Conclusions: NLR can be used as a biomarker to predict classification of COVID-19 patients independently, which can provide a theoretical basis for the classification management of COVID-19 patients.

Objective: To investigate the clinical characteristics of gastrointestinal symptoms in patients with coronavirus disease 2019 (COVID-19) during the whole disease process, and provide reference for etiological diagnosis and treatment., Methods: The clinical data of patients with COVID-19 admitted in the Infectious Diseases Branch of the First Affiliated Hospital of University of Science and Technology of China from January 22nd, 2020 to March 8th, 2020 were analyzed retrospectively. According to whether there were gastrointestinal symptoms (poor appetite, nausea/vomiting and diarrhea), all patients were divided into gastrointestinal symptom group and asymptomatic group. The characteristics of gastrointestinal symptoms, such as poor appetite, nausea, vomiting and diarrhea were counted and analyzed, and the correlation between gastrointestinal symptoms and gender, age, basic diseases, disease severity, laboratory examination and drug treatment were analyzed., Results: A total of 80 COVID-19 patients were involved, 43 cases (53.8%) presented with poor appetite, 17 cases (21.3%) had nausea and vomiting, and 33 cases (41.3%) had diarrhea. Among them, 5 cases, 1 case and 4 cases respectively preformed poor appetite, nausea/vomiting and diarrhea before admission, while the others experienced gastrointestinal symptoms within 48 hours after admission. Duration of poor appetite, nausea/vomiting and diarrhea (days) of all patients were 5.3±2.1, 2.2±1.0 and 1.4±0.9, respectively. The patients with poor appetite were older than those without symptoms (years old: 48.2±17.6 vs. 39.3±15.1), albumin (Alb) level and the lymphocytes ratio were lower than those in asymptomatic group [Alb (g/L): 39.8 (35.7, 45.1) vs. 46.1 (42.6, 49.4), lymphocytes ratio: 0.19 (0.09, 0.28) vs. 0.28 (0.17, 0.35)], while the neutrophil ratio, the levels of C-reactive protein (CRP), D-dimer, and lactate dehydrogenase (LDH) were higher than those in asymptomatic group [the neutrophil ratio: 0.74 (0.61, 0.85) vs. 0.64 (0.52, 0.76), CRP (mg/L): 21.4 (3.9, 52.9) vs. 5.6 (2.4, 14.0), D-dimer (mg/L): 0.2 (0.2, 0.5) vs. 0.2 (0.1, 0.3), LDH (μmol×s -1 ×L -1 ): 4.49 (3.59, 5.19) vs. 3.12 (2.77, 4.90)]; at the same time, more traditional Chinese medicine was used in the patients with gastrointestinal symptoms [65.1% (28/43) vs. 40.5% (15/37), all P < 0.05]. In addition, 14 cases of 18 patients with cardiovascular diseases presented with poor appetite, 7 patients had nausea and vomiting symptoms. All of the 3 patients with chronic kidney disease presented with poor appetite, nausea and vomiting, and 2 of them had diarrhea., Conclusions: The gastrointestinal symptoms in patients with COVID-19 are common. Whether it is caused by the virus or related drugs, diet and mental conditions, clinicians should analyze the causes of these symptoms timely, and then provide a better treatment for patients with COVID-19.

This study reports a boy with psychomotor retardation and epilepsy due to maternal phenylketonuria (PKU). The boy was admitted at the age of 20 months because of psychomotor retardation and epilepsy. He had seizures from the age of 1 year. His development quotient was 43. He presented with microcephaly, normal skin and hair color. Brain MRI scan showed mild cerebral white matter demyelination, broadening bilateral lateral ventricle and foramen magnum stricture. Chromosome karyotype, urine organic acids, blood amino acids and acylcarnitines were normal. His mother had mental retardation from her childhood. She presented with learning difficulties and yellow hair. Her premarriage health examinations were normal. She married a healthy man at age of 26 years. When she visited us at 28 years old, PKU was found by markedly elevated blood phenylalanine (916.54 μmol/L vs normal range 20-120 μmol/L). On her phenylalanine hydroxylase (PAH) gene, a homozygous mutations c.611A>G (p.Y204C) was identified, which confirmed the diagnosis of PAH-deficient PKU. Her child carries a heterozygous mutation c.611A>G with normal blood phenylalanine. Her husband had no any mutation on PAH. It is concluded that family investigation is very important for the etiological diagnosis of the children with mental retardation and epilepsy. Carefully clinical and metabolic survey should be performed for the parents with mental problems to identify parental diseases-associated child brain damage, such as maternal PKU.

Methylmalonyl CoA mutase deficiency due to MUT gene defect has been known as the main cause of isolated methylmalonic acidemia in Mainland China. This study reported a patient with isolated methylmalonic aciduria (MUT type) characterized as acute brainstem encephalitis and myelitis. The previously healthy girl presented with fever, lethargy and progressive weakness in her extremities at the age of 3 years and 2 months. Three day later, she had respiratory distress and consciousness. Cranial MRI revealed bilateral symmetrical lesion of pallidum, brain stem and spinal cord, indicating acute brainstem encephalitis and myelitis. Her blood propionylcarnitine (6.83 μmol/L vs normal range 1.0 to 5.0 μmol/L) and urinary methylmalonic acid (133.22 mmol/mol creatinine vs normal range 0.2 to 3.6 mmol/mol creatinine) increased significantly. Plasma total homocysteine was normal. On her MUT gene, a reported mutation (c.1630&#95;1631GG>TA) and a novel mutation (c.1663C>T, p.A555T) were identified, which confirmed the diagnosis of methylmalonic aciduria (MUT type). After cobalamin injection, protein-restricted diet with the supplements of special formula and L-carnitine, progressive improvement has been observed. The clinical manifestation of patients with methylmalonic aciduria is complex. Metabolic study and gene analysis are keys for the diagnosis and treatment of the disorder.

Purpose: To analyze the effect of ffh gene silencing on the aciduricity of fluoride resistant Streptococcus mutans in vitro., Methods: By using electroporation, UA159-FR was transformed and combined with targeted site of ffh gene sequence, and the best piece of siRNA for fluoride resistant Streptococcus mutans was screened. In different values of pH of BHI, they were cultured for 24 hours with UA159-FR respectively, and then centrifugated to determine the pH and OD600. SPSS17.0 software package was used to analyze the data., Results: The aciduricity of UA159-FR had significant differences compared with ffh gene silencing for UA159-FR in δpH (P<0.05), and the former was higher than the latter. At pH=3.5-5.0, P<0.01; at pH=5.5-7.5, P<0.05. Significant differences were noted in OD600 and their growth tendency were similar., Conclusions: The aciduricity of fluoride resistant Streptococcus mutans has significant effect when the ffh gene is silenced.

cblB defect is a rare type of methylmalonic aciduria. In this study, a Chinese boy was diagnosed with methylmalonic aciduria cblB type and a novel mutation in the MMAB gene. The clinical presentations, blood acylcarnitines profiles, urine organic acids and genetic features of the patient were reported. The boy presented with fever, feeding difficulty and lethargy at the age of 2 months. Seven days later, he had coma, cold limb, thrombocytopenia, metabolic acidosis and liver damage. His blood propionylcarnitine and urinary methylmalonic acid levels increased significantly, but the plasma total homocysteine level was in the normal range, which supported the diagnosis of isolated methylmalonic aciduria. Gene analysis was performed by direct sequencing. No mutation in the MUT gene was found. However, a reported mutation c.577G>A (p.E193K) and a novel mutation c.562G>A (p.V188M) in the MMAB gene were identified, which confirmed the diagnosis of methylmalonic aciduria cblB type. Progressive clinical and biochemical improvement has been observed after hydroxylcobalamin injection, protein-restricted diet with the supplements of special formula and L-carnitine. He is currently 3 years and 11 months old and has a normal development condition. The phenotypes of the patients with cblB defect are nonspecific. Metabolic analysis and MMAB gene analysis are keys for the diagnosis of the disorder.

Menkes disease is a rare X-linked recessive disorder characterized by multi-systemic disorder of copper deficiency caused by ATP7A gene mutation. In this study, the clinical and laboratory features of three patients with Menkes disease were analyzed. Prenatal diagnosis had been performed for a fetus of a family. Three patients were admitted at the age of 8-9 months due to severe epilepsies and marked delayed psychomotor development. Significantly light complexion, pudgy cheeks and sparse fuzzy wooly hair were observed. On their cranial MR imaging, cortical atrophy, leukoencephalopathy, basal ganglia damage and tormesity of the intracranial vessels were found. Their plasma ceruloplasmin decreased to 70.2, 73.5 and 81 mg/L, significantly lower than normal range (210-530 mg/L). c.3914A>G (p. D1305G) was detected on ATP7A gene of case 1 and 2. A novel mutation, c.3265G>T (p.G1089X) was found in case 3. Both of them were firstly found in Chinese patients of Menkes disease. The mother of case 1 was tested at 20 weeks of pregnancy. Karyotype and ATP7A gene studies of the amniocytes were performed for the prenatal diagnosis of her fetus. Normal male karyotypes without c.3914A>G mutation on ATP7A gene was showed. Postnatal genetic analysis and normal development confirmed the prenatal diagnosis.

Methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessive disorder. It is known that MTHFR deficiency may result in hyperhomocysteinemia, but MTHFR deficiency-induced schizophrenia has been rarely reported. Here we present the clinical course, biochemical and genetic characteristics of schizophrenia resulted from MTHFR deficiency in a school-age boy. He was 13 years old. He was admitted with a two-year history of fear, auditory hallucination, learning difficulty, sleeping problems, irascibility, drowsing and giggling. At admission, he had significantly elevated plasma and urine levels of total homocysteine, significantly decreased levels of folate in serum and cerebrospinal fluid, and a normal blood concentration of methionine. Further DNA sequencing analysis showed 665C>T homozygous mutations in the MTHFR gene. The patient was diagnosed with MTHFR deficiency-associated schizophrenia and treatment with calcium folinate, vitamin B12, vitamin B6, and betaine was initiated. After the treatment for 1 week, his plasma and urine levels of homocysteine were decreased to a normal range and the clinical symptoms were significantly improved. After 3 months of treatment, the patient returned to school. He is now living with normal school life. In summary, children with late-onset MTHFR deficiency and secondary cerebral folate deficiency may lead to schizophrenia. This rare condition can be early diagnosed through analyses of blood and urine total homocysteine, amino acids in blood and folate in blood and cerebral fluid and successfully treated with folinic acid, vitamin B6, vitamin B12 and betaine.

Objective: Mitochondrial disease is a group of energy metabolic disorders, characterized by involvement of multisystem with high energy requirements. Encephalomyopathies are common clinical findings of the mitochondrial diseases. However, mitochondrial cardiac damage is not rare. In this study, the clinical, biological, and genetic analyses were performed in three patients with mitochondrial cardiac damage, in order to understand the characteristics of mitochondrial diseases., Method: Three girls presented with arrhythmia and cardiac enlargement from the age of 3, 4 and 8 years respectively. They were admitted into the Peking University First Hospital. Infection, autoimmune diseases, aminoacidopathies, organic acidurias, mitochondrial-fatty acid oxidation defects, and lysosomal storage disease were excluded by routine laboratory examinations and metabolic analysis for blood amino acids, acylcarnitines, urinary organic acids, and lysosome activity assay. Peripheral leukocytes mitochondrial respiratory chain enzyme I to V activities were measured by spectrophotometry. The entire sequence of the mitochondrial DNA was analyzed., Result: In two patients (case 1 and case 3), hypertrophic cardiomyopathy and grade I to grade II of cardiac function were found. One patient (case 2) was diagnosed with arrhythmia and grade I of cardiac function. Increased creatine phosphokinase and creatine kinase isoenzyme MB were observed. Mitochondrial respiratory chain complex deficiencies were indentified in the three patients. Patient 1 had combined deficiencies of complex III and V. The activity of complex I+III was 18.7 nmol/(min·mg mitochondrial protein) (control 84.4 ± 28.5). The activity of complex V was 20.4 nmol/(min·mg mitochondrial protein) (control 103.7 ± 29.2). In her mitochondrial gene, A14693G on tRNA(Glu) and T16519C on D-loop were found. Patient 2 had an isolated complex I deficiency. The activity was 22.0 nmol/(min·mg mitochondrial protein) (control 44.0 ± 5.4). A16183C, T16189C and G15043A mutations on D-loop were found. Patient 3 had a combined deficiency of complex IV and V. The activity of complex IV was 21.0 nmol/(min·mg mitochondrial protein) (control 54.1 ± 12.3). The activity of complex V was 23.2 nmol/(min·mg mitochondrial protein) (control 103.7 ± 29.2). C253T and C16187T mutations on D-loop were detected. Haplotype analysis showed that three patients belong to H2a2a. Improvement was observed after the treatment with L-carnitine, coenzyme Q10, vitamin C and E. At present, the patients are 7, 5 and 8 years old. Although excise intolerance still persists, they had a good general condition with normal school life., Conclusion: The mitochondrial diseases with cardiac damage show cardiomyopathy, arrhythmia and exercise intolerance. Many kinds of mitochondrial respiratory chain deficiency were observed. A14693G in mitochondrial tRNA(Glu) gene is probably one of the causes in China.

Argininemia is a rare, autosomal recessive, metabolic disorder caused by an hereditary deficiency of hepatocytes arginase due to ARG1 gene defect. Arginase is the final enzyme in the urea cycle, catalyzing the hydrolysis of arginine to ornithine and urea. Research advances in the clinical manifestations, diagnosis, treatment, prenatal diagnosis and genetics of argininemia were reviewed in this paper. The clinical manifestations of patients with argininemia are complicated and nonspecific so that clinical diagnosis is usually difficult and delayed. Progressive spastic tetraplegia, seizures and cerebella atrophy are common clinical features of the disease. Blood amino acids analysis, arginase assay and ARG1 gene analysis are important to the diagnosis of argininemia. Early diagnosis and a protein-restricted diet with citrulline and benzoate supplements can contribute a lot to improve patient prognosis. With the application of liquid chromatography-tandem mass spectrometry in selective screening and newborn screening for inborn errors of metabolism, an ever-increasing number of patients with argininemia are detected at the asymptomatic or early stages.

Fabry disease is an X-linked recessive lysosomal storage disorder caused by a deficiency of α-galactosidase A (GLA). Intracellular accumulation of globotriaosylceramide, the glycolipid substrate of this enzyme, leads to severe painful neuropathy with progressive renal, cardiovascular, and cerebrovascular dysfunction. Patients of severe cases die young. It has been proved that enzyme replacement therapy is a useful method to treat patients with Fabry disease. But the clinical diagnosis of the patients may often be difficult because of the lack of specific symptoms. In this study, a Chinese boy was diagnosed as Fabry disease at the age of 11 years with episodic pain for 7 years. The boy described the onset, at the age of 4 years, of episodic burning pain in the toes. Generalized aching and pain in the feet became progressive in the past two years and his hands were also affected. Divers analgesics were tried without effects. When he was admitted at the age of 11 years, none of complications was found in his heart, brain, kidneys, skin and eyes by routine laboratory examinations. Significantly decreased GLA activity of peripheral leucocytes [1.0 nmol/(h×mg protein) vs. normal control 24.5 to 86.1 nmol/(h×mg protein)] supported the diagnosis of Fabry disease. A splicing mutation IVS6+2 T>C was identified on his GLA gene. But it was not found in his mother and younger sister. The incidence of Fabry disease is not clear in Mainland China. The patients usually have insidious onset with complex and non-specific clinical manifestations. Stroke, uremia, cardiomyopathy and multiple organ dysfunctions are common at the late stage. Early diagnosis is the key point to reduce the mortality and handicap. GLA enzyme activity is important to the diagnosis of Fabry disease. The mutation analysis of GLA gene is helpful for genetic counseling.

Based on the annual investigation data of biological resources in Lidao artificial reef zone in 2009, an Ecopath model of the Lidao artificial reef ecosystem was constructed to analyze the energy flow pattern and the system attributes of the ecosystem. The model was consisted of 19 functional groups, basically covering the main processes of the energy flow in the Lidao artificial reef ecosystem. The functional groups were divided according to the relationships of the corresponding positions between appeared fishes and artificial reefs, and the planktonic heterotrophic bacteria were included into the model as a functional group. The fishes appeared in the investigation zone were divided into seven functional groups, and the trophic levels of the functional groups varied from 1.00 to 3.72. The type I fishes had the highest trophic level. The total system throughput was estimated to be 10786.68 t x km(-2) x a(-1), 27% of which flowed to detritus, and 17% flowed out the ecosystem in the forms of fishing and sediment. The total net primary productivity of the system was 4131.97 t x km(-2) x a(-1) and the total energy transfer efficiency was 10.5%. The proportion of the total flow originated from detritus was 39%, and that from primary producers was 61%, indicating that the energy flow was dominated by food web rather than detritus. The ratio of total primary productivity to total respiration of the system was 1.84, the connectivity index was 0.20, and the Finn's cycling index and the mean path length of the energy flow were 4.5% and 2.62, respectively. This study showed that the Lidao artificial reef ecosystem had a relatively low maturity and stability, was at a developing stage, and had weak resistance against outside interference. The ecological environment and the output of fisheries in the artificial reef zone would have inter-annual fluctuations, and thus, the eco-environment restoration of the artificial reef ecosystem could only be realized by the sustainable maintaining of the ecosystem.

This study reviews a case of mitochondrial respiratory chain complex I deficiency due to the 10191T>C mutation in mitochondrial ND3 gene. The previously healthy boy progressively presented with blepharoptosis, weakness, epilepsy and motor regression at age 6 years. Elevated blood lactate and pyruvate were observed. Brain magnetic resonance imaging showed symmetrical lesions in the basal ganglia. Leigh syndrome was thus confirmed. The protein from the mitochondria and genomic DNA of the boy and his parents was collected from peripheral blood leucocytes for the activity test for mitochondrial complex I to V and genetic analysis. The results showed the activity of complex I (33.1 nmol /min in 1 milligram mitochondrial protein) was lower than normal reference value (44.0±5.4 nmol /min in 1 milligram mitochondrial protein). The ratio of complex I to citrate synthase (19.8%) was also lower than normal reference value (48%±11%). The activities of complexes II to V were normal. 10191T>C mutation in ND3 gene of mitochondria was identified in the boy. 10191T>C mutation and complex I deficiency were not detected in his parents. At present, he is 16 years old, and of normal intelligence with spastic paralysis in both lower extremities after treatment. It is concluded that a Chinese boy with isolated complex I deficiency due to 10191T>C mutation in ND3 gene was firstly diagnosed by peripheral leukocytes mitochondrial respiratory chain enzyme assay and gene analysis. This study can provide clinical data for the nosogenesis of Leigh syndrome.

Objective: Methylmalonic aciduria is the most common disorder of organic acidurias in the mainland of China. It is also the one of treatable metabolic disorders. The clinical spectrum of the patients varies from severe neonatal-onset forms with neonatal brain injury and high mortality to milder forms with adult-onset. The clinical manifestations of neonates with methylmalonic aciduria are non-specific. Early diagnosis and adequate treatment contribute a lot to improving the prognosis of the patients. In this study, the abnormal clinical and laboratory findings in neonatal period of 160 Chinese patients with early-onset methylmalonic aciduria were investigated., Method: From 1996 to 2011, a total of 398 patients with methylmalonic aciduria were diagnosed in our hospital; 286 (71.9%) patients had early-onset before 1 year of age. Among 286 patients, 160 (55.9%) presented symptoms in neonatal period. Their urine organic acids were analyzed by gas chromatography-mass spectrometry. Blood amino acids and acylcarnitine profiles were determined by liquid chromatography tandem mass spectrometry. Serum and urine total homocysteine were measured using a fluorescence polarization immunoassay. In some patients, gene analysis was performed. Based on the disease types and general condition, individual dietary and medical interventions were started soon after diagnosis., Result: Out of the 160 patients, 131 (81.9%) had combined methylmalonic aciduria and homocysteinemia. Isolated methylmalonic aciduria was found in 29 cases (18.1%). The common presentations in neonatal period were feeding difficulty, seizures, lethargy and dyspnea. Megaloblastic anemia, liver dysfunction, hyperammonemia and metabolic acidosis were the frequent findings in the routine laboratory test. The most common initial clinical diagnosis was suspected hypoxic-ischemic encephalopathy. Even in 36 cases with abnormal family history, only 3 patients were admitted with suspected inborn errors of metabolism. Five cases (3.1%) were diagnosed by postmortem metabolic examination; 7 cases (4.4%) were detected by newborn screening. In 148 cases (92.5%), the diagnosis was much delayed to the age of one month to 8 years and 5 months (mean 13 months). Methylmalonic aciduria combined with homocysteinemia (MMACHC) gene analyses were performed in 31 cases with combined methylmalonic aciduria. CblC defect was confirmed. The patients with isolated methylmalonic aciduria were treated with protein-restricted diet, cobalamin and L-carnitine. The patients of methylmalonic aciduria combined with homocysteinemia were treated with cobalamin, L-carnitine, calcium folinate, betaine and common diet. Seven patients died without treatment. Clinical improvement was observed in 153 patients. Only 2 patients detected by newborn screening had normal mental and physical development. Mild to severe psychomotor retardation was observed in 151 cases., Conclusion: High mortality and disability rates were observed in the patients with early-onset methylmalonic aciduria. Combined methylmalonic aciduria and homocysteinemia is the common type of methylmalonic aciduria. The clinical manifestation in neonatal period of the patients with early-onset methylmalonic aciduria is complex. Feeding difficulty, seizures, lethargy and dyspnea are the common symptoms in neonatal period of the patients. Megaloblastic anemia, liver dysfunction, hyperammonemia and metabolic acidosis were the frequent laboratory findings.

Objective: To observe the expression of the matrix metalloproteinase 2 (MMP-2) and membrane-type 1 metalloproteinase (MT1-MMP) in lung of rats exposed to paraquat (PQ) and the effects of Salvia miltiorrhiza monomer IH764-3 on above expression., Methods: Ninety adult healthy Sprague-Dawley (SD) rats were randomly divided into the control group (group A, 6 rats), the exposure group (group B, 42 rats) and the group treated by Salvia miltiorrhiza monomer IH764-3 (group C, 42 rats). The group B and C were treated intragastrically with 1ml of PQ (50 mg/kg), and the group A was treated intragastrically with normal saline. The group C was treated intraperitoneally with 1 ml Salvia miltiorrhiza monomer IH764-3 at the dose of 40 mg/kg a day. The group A and B were treated intraperitoneally with 1 ml normal saline day. The expression of MMP-2 and MT1-MMP was detected on the 1st, 3rd, 7th, 14th, 21st, 28th and 35th days after exposure for all groups., Results: As compared with the expression level (0.305 ± 0.045) of MMP-2 mRNA in group A, the expression levels of MMP-2 mRNA in Group B significantly increased, which were 0.654 ± 0.077, 0.623 ± 0.051, 0.637 ± 0.024, 0.533 ± 0.043 and 0.552 ± 0.050 on the 1st, 3rd, 7th, 14th, 21st days after exposure, respectively (P < 0.01). As compared with group A, the the expression levels of MMP-2 mRNA on the 1st, 3rd, 7th days in Group C slightly increased, but the expression levels of MMP-2 mRNA on the 1st, 3rd, 7th, 14th, 21st days in Group C were 0.523 ± 0.074, 0.567 ± 0.097, 0.514 ± 0.058, 0.359 ± 0.018 and 0.374 ± 0.020, respectively, which were significantly lower than those in group B (P < 0.01). As compared with the expression level (0.391 ± 0.058) of MT1-MMP mRNA in group A, the expression levels of MT1-MMP mRNA in Group B significantly increased, which were 0.796 ± 0.021, 0.762 ± 0.043, 0.590 ± 0.010, 0.803 ± 0.076 and 0.680 ± 0.034 on the 1st, 3rd, 7th, 14th and 21st days after exposure, respectively (P < 0.01). As compared with group A, the expression levels of MT1-MMP mRNA in Group C significantly increased, which were 0.594 ± 0.010, 0.653 ± 0.044 and 0.564 ± 0.009 on the 1st, 3rd and 21st days after exposure, respectively (P < 0.01). The expression levels of MT1-MMP mRNA in Group C were significantly lower than those in group B (P < 0.05 or P < 0.01)., Conclusion: The expression changes of MMP-2 and MT1-MMP genes of lungs in rats intragastrically exposed to PQ could result in the unbalance the synthesis and degradation of ECM, which may be a cause of lung fibrosis. The Salvia miltiorrhiza monomer IH764-3 could affect the expression of MMP-2 and MT1-MMP genes to a certain extent, resulting in the reduction of lung fibrosis.

Mitochondrial respiratory chain deficiency is a common cause of mitochondrial disease in children. This study aimed to review the clinical, enzymatic and genetic characteristics of a Chinese boy with progressive intrahepatic cholestasis due to mitochondrial respiratory chain complex I deficiency. The boy developed diarrhea from the age of 13 months, followed by progressive body weight loss, jaundice and weakness. His urine organic acids, blood amino acids and acylcarnitines profiles were normal. Mitochondrial respiratory chain complexes I to V activities in peripheral leukocytes were measured using spectrophotometric assay. Complex I activity was reduced. 5821G>A mutation was indentified by gene sequencing on tRNA-cys of mitochondrial gene in the patient and his mother. Vitamin supplements, liver protection, antibiotics and plasma infusion were not effective in the patient. Unfortunately, the boy died at the age of 17 months. Mitochondrial respiratory chain complex I deficiency is the most common mitochondrial respiratory chain disorder. This was the first case of intrahepatic cholestasis due to complex I deficiency confirmed by mitochondrial respiratory chain enzyme activity assay and gene analysis in China. It was concluded that mitochondrial hepatopathy is one of major causes of metabolic hepatopathy. Biochemical assay, mitochondrial respiratory chain complex activities assay and genetic analysis are crucial for the etiological diagnosis of metabolic hepatopathy.

Objective: To study the clinical and enzymological characteristics of the children with mitochondrial respiratory chain complex III deficiency., Method: The clinical manifestations of five patients (3 males, 2 females) were summarized. Spectrophotometric assay was used for the analysis of respiratory chain complex I to V enzyme activity in peripheral blood leukocytes, after obtaining venous blood., Result: (1) Five patients were hospitalized at the age of 1 month to 15 years. Three patients had Leigh syndrome with progressive motor developmental delay or regression and weakness. One had severe liver damage and intrahepatic cholestasis. One presented muscle weakness. (2) Deficient complex I + III activity was identified in five patients. Their complex I + III activities in peripheral blood leukocytes were 3.0 to 14.2 nmol/min per mg mitochondrial protein (control: 84.4 ± 28.5 nmol/min per mg mitochondrial protein). The ratio of complex I + III to citrate synthase decreased to 3.5 to 22.9% (normal control 66.1 ± 14.7%). The activities of complex III decreased to 10.4 to 49.3% of the lowest control value, while complex I, II, IV and V activities were normal. The results supported the diagnosis of isolated respiratory chain complex III deficiency., Conclusion: Complex III deficiency is a kind of disorder of energy metabolism with various manifestations. The complex I + III activities and the ratio of complex I + III to citrate synthase were lower than those of the control. The activities of complex I, II, IV and V were normal.

Mitochondrial respiratory chain complex II deficiency is a rare documented cause of mitochondrial diseases. This study reported a case of Leigh syndrome due to isolated complex II deficiency. A boy presented with progressive weakness, motor regression and dysphagia after fever from the age of 8 months and hospitalized at the age of 10 months. Elevated blood levels of lactate and pyruvate were observed. Brain magnetic resonance image showed symmetrical lesions in the basal ganglia. Mitochondrial respiratory chain complex I-V activities in peripheral leukocytes were measured using spectrophotometric assay. Mitochondrial gene screening of common point mutations was performed. The complex II activity in the peripheral leukocytes decreased to 21.9 nmol/min per mg mitochondrial protein (control: 47.3±5.3 nmol/min per mg mitochondrial protein). The ratio of complex II activity to citrate synthase activity (22.1%) also decreased (control: 50.9%±10.7 %). No point mutation was found in mitochondrial DNA. The boy was diagnosed as Leigh syndrome due to isolated complex II deficiency. Psychomotor improvements were observed after the treatment. The patient is 22 months old and in a stable condition.

3-Hydroxy-3-methylglutaric aciduria is a rare disorder of organic acid metabolism caused by 3-hydroxy-3-methylglutaryl-coenzyme A lyase deficiency. The disorder was common in neonatal or infant period. Here a case of late onset 3-hydroxy-3-methylglutaric aciduria complicated by leucodystrophy was reported. The patient was a 7-year-old boy. He presented with progressive headache, drowsiness and vomiting. Hepatic lesions, ketosis and leucopenia were found. Symmetrical diffused leucodystrophy was shown by MRI. Blood levels of isovalerylcarnitine and acetylcarnitine increased significantly. Urinary levels of 3-hydroxy-3-methylglutaric, 3-methylglutaconic, 3-hydroxyglutaric acids and 3-methyl-crotonylglycine increased significantly. Symptoms were released by intravenous infusion of L-carnitine and glucose. After treatment for 6 months, urinary levels of 3-hydroxy-3-methylglutaric aciduria decreased in the boy and his health improved.

Objective: To investigate the expression of nuclear factor kappa B (NF-kgr;B) and tumor necrosis factor α (TNF-α) in lung tissue of acute paraquat poisoned rats., Methods: 68 male Wistar rats were randomly divided into 2 groups: the control group (n = 8), the intoxication group (n = 60). On the 1st, the 3rd, the 7th, the 14th and the 28th day after intoxication, the expression of NF-κB p65 and TNF-α in lung tissue were detected by LSAB immunohistochemistry (IH) staining. Meanwhile, the level of malondialdehyde (MDA) in plasma, and lung homogenate, the content of malondialdehyde (HPY) in lung homogenate were detected., Results: The levels of MDA in plasma on the 1st, the 3rd, the 7th day and in lung homogenate on the 1st, the 3rd day of the intoxication group [in plasma: (10.15 ± 3.15), (6.97 ± 1.65) and (5.44 ± 0.66) nmol/ml; in lung homogenate: (10.20 ± 2.43), (10.71 ± 171) nmol/ml] were significantly higher than that of the control group [in plasma: (3.84 ± 1.04) nmol/ml, in lung homogenate: (7.66 ± 0.66) nmol/ml]. The content of HPY in lung homogenate on the 14th and the 28th day after intoxication [(19.98 ± 2.86), (26.06 ± 4.06) µg/0.1 g lung homogenate] were higher than that of the control group [(8.80 ± 1.26) µg/0.1 g lung homogenate] significantly. The expression of NF-κB p65 and TNF-α in lung tissue were both significantly increased on the first day and the 3rd day of the intoxication group compared with the control group and weakened obviously after the 7th day., Conclusion: Acute paraquat poisoning can induce increased expression of both NF-κB p65 and TNF-α in lung tissue; the enhanced activity of NF-κB may take part in the process of pulmonary injury in PQ poisoning.

Objective: To study the mechanism of paraquat-induced renal injury in rats., Methods: Adult healthy Sprague-Dawley (SD) rats (female and male in half) were randomly divided into two groups, the control group and the paraquat poisoned group. The rats in the paraquat poisoned group were treated with PQ (25 mg/kg) intraperitoneally while the rats in the control group were treated with the same dose of normal saline. Its histopathological change was observed and the expression of HO-1 and the mRNA expression of HO-1 were detected by RT-PCR at 3rd h, 6th h, 12th h, on 1st d, 2nd d, 3rd d and 5th d., Results: (1) In the control group, the tissue structure was clear without edema, vacuolar degeneration, cloudy swelling and necrosis. In the paraquat poisoned group, there were obvious lesions in the renal tubule of cortical part, including cellular swelling, the narrow cannula, the mesenchymal congestion and edema. These pathologic changes gradually became more severe, reached the peak on the 1st day, and did not relieve until the end of this study; there was the karyopyknosis and the cyto-architecture disappeared in some severe cases; Some glomerulus and medulla were also involved. (2) In the control group, there was no or weak expression of HO-1 and HO-1 mRNA. At the 3rd hour, the expressions of HO-1 in the paraquat poisoned group were observed in the membrane and cytoplasm of renal tubular epithelial cell of cortical part. Immunohistochemistry score (IHS) in the paraquat poisoned group was higher than that in the control group (P<0.05), except the HIS of the 5th day. At the 3rd hour, the expression of HO-1 mRNA increased, reached the peak on the 1st day, and then decreased. The expression of HO-1 mRNA was (0.53 +/- 0.21), (0.55 +/- 0.31), (0.56 +/- 0.22), (0.64 +/- 0.14) and (0.43 +/- 0.25) at the time point other than on the 3rd and 5th day. It showed statistical difference between the paraquat poisoned group and the control group from the 3rd hour to the 2nd day (P<0.05)., Conclusion: The mechanism of paraquat induced-renal injury is multiple. The higher expression of HO-1 and HO-1 mRNA were involved in the procedures of paraquat-induced renal injury.

Objective: To investigate NF-kappaB activity and the expression of phosphorylated p38 MAPK protein in lung tissue of acute paraquat poisoned rats and the effect of MT., Methods: One hundred and twenty-eight Sprague-Dawley (SD) rats were randomly divided into three experimental groups: poisoned group, MT group and control group. On the 1st, the 3rd, the 7th and the 14th day after exposure, levels of malondialdehyde (MDA) in serum were detected, NF-kappaB activity in the lung tissues was assessed by electrophoresis mobility shift assay (EMSA), the expression of the phosphorylated p38 MAPK was evaluated by Western blot method, the lung pathological changes of rats were observed., Results: The level of malondialdehyde (MDA) in serum increased significantly in poisoned group on the 1st day (4.45 +/- 1.23), the 3rd day (3.77 +/- 1.12) and the 7th day (2.84 +/- 0.96) nmol/ml compared with that in control group (1.36 +/- 0.52) nmol/ml (P < 0.01). There was a significant decrease in MT group on the 1st day (2.68 +/- 0.85), the 3rd day (1.97 +/- 0.74) and the 7th day (1.53 +/- 0.62) nmol/ml compared with poisoned group (P < 0.05). The expression of the phosphorylated p38 MAPK and NF-kappaB activity in lung tissue of poisoned group significantly increased compared with control group (P < 0.01). There was a significant decrease in NF-kappaB activity and expression of the phosphorylated p38 MAPK in the lung tissues in MT group compared with poisoned group (P < 0.05)., Conclusion: NF-kappaB and p38 MAPK could play an important role in lung injury of poisoned rats. MT may inhibit the expression of NF-kappaB and phosphorylated p38 MAPK, and therefore might have the therapeutical effect on acute paraquat poisoning.

Objective: To further disclose mechanisms in adaptation of pulmonary and systemic arteries to simulated microgravity (SM), so as to elucidate the mechanisms accounting for orthostatic intolerance after SM, and to explore a new kind of countermeasure for orthostatic intolerance., Method: 300 tail suspended (TS) rats were used as the model to simulate the physiological effects of microgravity. Vasoreactivity changes of rings sectioned from pulmonary artery (PA) and thoracic aorta (TA) to 68 mmoles/L KCl, plus phenylephrine (PE) and acetylcholine (ACh) were observed after 7 d and 14 d tail-suspension. After preconditioning with 10(-5) moles/L N-nitro-L-arginine methyl ester (L-NAME) for 20 min, vasoreactivity changes of PA and TA to PE and ACh were respectively repeated., Result: The contractile responsiveness of PA and TA to KCl and PE decreased significantly or very significantly after TS7 d and TSI4 d. The dilatory reactivity of PA and TA to ACh after TS7 d had a significant or very significant increase, but reactivity of PA showed no change and TA showed only a tendency to increase after TS14 d. After preconditioning with 10(-5) moles/L L-NAME, responsiveness of PA to PE after TS7 d and TS14 d had no difference among the three groups, but responsiveness of TA to PE after TS7 d and TS14 d had a significant decrease. The dilatory reactivity of PA after TS7 d decreased significantly or very significantly, and the remains showed no significant change., Conclusion: The decrease of contractile responsiveness of PA and TA might be due to the increased dilatory function of the endothelial cells. The fact that 10(-5) moles/L L-NAME reversed the decrease of contractile responsiveness of PA and partly of TA after tail suspension implicates that there might be an inhibitory action on the dilatory function of the endothelial cells. The NOS inhibitors may be helpful in preventing orthostatic intolerance.

Objective. To study the difference between two types of event-related brain potentials (ERPs) in auditory location discrimination task. Method. Event-related potentials (ERPs) in auditory location discrimination task were recorded in 14 normal subjects and were compared with head-down tilt (HDT) and head-up tilt (HUT) conditions. Result. 1) The subjects could be divided into group I (n=7) and group II (n =7) according to the feature of the target ERPs component (P3). The difference between the two groups was mainly that there was a negative slow wave after 150 ms in the ERPs of group II subjects, and that the reaction time and error rate in II group was higher than in I group. These data indicated that the psychological load on group II was larger than that on group I. 2) The reduction of mean slow potential amplitude during HDT was more significant in group II than in group I. Conclusion. The slow potential amplitude of ERPs may reflect the psychological load and the brain function state. Attention should be paid to the feature of auditory ERPs in space medical practice.

Objective. To study N2 effect and its feature on non-target event-related brain potentials during auditory selective attention. Method. The subjects were 16 healthy right-handed male volunteers aged 23.2 +/- 2.1 years. The stimuli were male voice of one-digit numbers (2 to 7), which were single syllable pronunciated in Chinese, and appeared randomly with equal probability. The subjects were asked to press a switch as soon as the target signal (odd or even number) was heard but make no response to the non-target signal. EEG signals at 9 locations were recorded. Result. 1) A negative component N280 (N2 effect) was found after non-target stimuli as compared to target stimuli, which was significant in the frontal brain locations; 2) P3 was smaller and its peak appeared later in non-target ERPs than in target ERPs. Conclusion. N2 effect was also elicited by non-target stimuli during auditory modality. We assume that N2 effect might reflect the readjusting of model stored in working memory at the frontal brain.