[Analysis of 9 patients with adolescence-onset methylenetetrahydrofolate reductase deficiency]

Objective: To explore the diagnosis and treatment of adolescence-onset methylenetetrahydrofolate reductase (MTHFR) deficiency. Methods: This was a retrospective case study. Nine patients with adolescence-onset MTHFR deficiency were diagnosed at Peking University First Hospital from January 2016 to December 2022, and followed up for more than 1 year. Their general information, clinical manifestations, laboratory tests, cranial images, MTHFR gene variants, diagnosis, treatment, and outcome were analyzed retrospectively. Results: The 9 patients came from 8 families. They had symptoms at age of 8.0 years to 17.0 years and diagnosed at 9.0 years to 17.5 years. Eight were male and 1 was female. Two patients were brothers, the elder brother developed abnormal gait at 17.0 years; and the younger brother was then diagnosed at 15.0 years of age and treated at the asymptomatic stage, who was 18.0 years old with normal condition during this study. The main manifestations of the 8 symptomatic patients included progressive dyskinesia and spastic paralysis of the lower limbs, with or without intellectual decline, cognitive impairment and behavioral abnormalities. Totally, 15 variants of MTHFR gene were identified in the 9 patients, including 8 novel variants. Five patients had brain image abnormalities. Increased plasma total homocysteine level (65-221 μmol/L) was found in all patients, and decreased to 20-70 μmol/L after treatment with betaine and calcium folinate. Besides, the 8 symptomatic patients had their behavior and cognitive problems significantly improved, with a legacy of lower limb motor disorders. Conclusions: Late-onset MTHFR deficiency can occur in adolescence. The diagnosis is usually delayed because of non-specific clinical symptoms. The test of blood total homocysteine could be used as a selective screening test. Eight novel varients of MTHFR gene were identified. Timely treatment can improve clinical condition significantly, and pre-symptomatic treatment may prevent brain damage.

Organotins in a food web from the Three Gorges Reservoir, China: Trophic enrichment and potential health risk

Triphenyltin (TPhT) and tributyltin (TBT) remain widely present in various aquatic environments despite restrictions on their use in many countries for many years. The biomagnification of these compounds in the aquatic food web remains controversial. This study reports the bioaccumulation of TPhT and TBT in aquatic animals in the Three Gorges Reservoir (TGR), a deep-water river channel-type reservoir and the largest reservoir in China. We measured TPhT, TBT and their metabolites in 2 invertebrates, 27 fish and the aquatic environment. The logarithmic bioaccumulation factors of TPhT and TBT were 4.37 and 3.77, respectively, indicating that TPhT and TBT were enriched in organisms of the TGR. Both TPhT and TBT concentrations were significantly and positively correlated with trophic level, with trophic magnification factors of 3.71 and 3.63, respectively, indicating that TPhT and TBT exhibited similar trophic enrichment in the freshwater food web of the TGR. The results of health risk assessment showed that although all hazard index (HI) values were <1, more attention should be paid to the health risk to children associated with consumption of aquatic products (HI = 0.67). This study provides powerful evidence of trophic enrichment of TPhT and TBT in a freshwater food web in a deep-water river channel-type reservoir and provides valuable data regarding organotins in aquatic animals in the TGR.

[Phenotypes and genotypes of 78 patients with propionic acidemia]

Objective: Propionic acidemia is a rare inherited metabolic disorder caused by propionyl CoA carboxylase (PCC) deficiency. This study aims to analyze the clinical characteristics and gene variations of Chinese patients with propionic acidemia, and to explore the correlation between clinical phenotypes and genotypes. Methods: Single-center, retrospective and observational study. Seventy-eight patients of propionic acidemia (46 males and 32 females) from 20 provinces and autonomous regions were admitted from January 2007 to April 2022. Their age of initial diagnosis ranged from 7 days to 15 years. The clinical manifestations, biochemical and metabolic abnormalities, genetic variations, diagnosis, treatment and outcome were studied. Chi-Square test or Mann-Whitney U test were used for statistical analysis. Results: Among 78 cases, 6 (7.7%) were identified by newborn screening; 72 (92.3%) were clinically diagnosed after onset, and the age of onset was 2 hours after birth to 15 years old; 32 cases had early-onset disease and 40 cases had late-onset disease. The initial manifestations included lethargy, hypotonia, vomiting, feeding difficulties, developmental delay, epilepsy, and coma. Among the 74 cases who accepted gene analysis, 35 (47.3%) had PCCA variants and 39 (52.7%) had PCCB variants. A total of 39 PCCA variants and 32 PCCB variants were detected, among which c.2002G>A and c.229C>T in PCCA and c.838dupC and c.1087T>C in PCCB were the most common variants in this cohort. The variants c.1228C>T and c.1283C>T in PCCB may be related to early-onset type. The variants c.838dupC, c.1127G>T and c.1316A>G in PCCB, and c.2002G>A in PCCA may be related to late-onset disease. Six patients detected by newborn screening and treated at asymptomatic stage developed normal. The clinically diagnosed 72 cases had varied complications. 10 (12.8%) cases of them died. 62 patients improved after metabolic therapy by L-carnitine and diet. Six patients received liver transplantation because of recurrent metabolic crisis. Their clinical symptoms were markedly improved. Conclusion: The clinical manifestations of propionic acidemia are complex and lack of specificity. Newborn screening and high-risk screening are keys for early treatment and better outcome. The correlation between the genotype and phenotype of propionic acidemia is unclear, but certain variants may be associated with early-onset or late-onset propionic acidemia.

[Clinical characteristics and CBS gene analysis of 13 cases with classic homocystinuria]

Objective: To analyze the clinical features and CBS gene variants of 13 patients with classic homocystinuria, and the strategies of individual treatment and prevention were explored. Methods: The general information, clinical manifestations, laboratory tests, cranial images, CBS gene variants, diagnosis and therapeutic strategies of 13 patients with classic homocystinuria admitted to the Department of Pediatrics of Children's Hospital Affiliated to Zhengzhou University and Peking University First Hospital from November 2013 to June 2021 were analyzed retrospectively. Results: There were 13 patients diagnosed at the age of 10 days to 14 years, 6 were male and 7 were female. There were 3 patients detected by newborn screening and received treatment at the asymptomatic stage. There were 10 patients clinically diagnosed at the age of 5 to 14 years. Their symptoms appeared at age of 1 to 6 years. The major clinical manifestations were marfanoid features, lens dislocation and (or) myopia, developmental delay, osteoporosis, and cardiovascular diseases. Brain magnetic resonance imaging showed asymmetric infarcts in 4 patients and hypomyelination in 1 case. Increased blood methionine, plasma total homocysteine and urinary total homocysteine with normal urinary methylmalonic acid were found in 13 patients. The biochemical features were consistent with classic homocystinuria. Totally 18 variants were identified in CBS gene of 13 patients, 10 variants were novel and 8 were reported. only 1 patient was partially responsive to vitamin B₆ treatment, while 12 cases were non-responsive. They were mainly treated with low methionine diet and betaine supplement. Three vitamin B₆ non-responsive cases received liver transplantation at age of 3, 8 and 8 years, respectively. Their blood methionine and total homocysteine returned to normal within a week after liver transplantation. One patient died. Prenatal diagnosis was performed for a fetus when the mother was pregnant again. Two pathogenic CBS gene variants were identified from the amniocytes as same as the proband. Conclusions: The clinical manifestations of classic homocystinuria are complex and variable. Blood amino acid analysis, serum or urine total homocysteine assay and gene analysis are critical for its diagnosis. There were 10 novel CBS gene varients were identified expanding the CBS gene varient spectrum. Liver transplantation is an effective treatment. Prenatal diagnosis is important to prevent classic homocysteinuria.

[Genetic variants, circulating levels of monocyte chemoattractant protein-1 with risk of breast cancer: a case-control study and Mendelian randomization analysis]

Objective: To assess the association of genetic polymorphisms and circulating levels of chemokine monocyte chemoattractant protein-1 (MCP1) with risk of breast cancer. Methods: A total of 820 patients with pathologically confirmed breast cancer and 900 age-and area-of-residence-matched healthy controls who visited the hospital for routine health screening during the same period were included in this case-control study. Mendelian randomization analysis was performed using three widely followed functional single nucleotide polymorphisms (SNPs) of the MCP1 gene rs1024611, rs2857656 and rs4586 to construct instrumental variables. Results: MCP1 rs1024611 (OR=1.26, P=0.002), rs2857656 (OR=1.23, P=0.006) and rs4586 (OR=1.23, P=0.003) were significantly associated with increased risk of breast cancer. SNP rs1024611 (β=1.194, P<0.001), rs2857656 (β=1.221, P<0.001) and rs4586 (β=1.137, P<0.001) were positively correlated with higher circulating level of MCP1. The case-control study showed that an increase of 23.7 pg/ml of circulating levels of MCP1 was associated with a 0.25-fold increased risk of breast cancer. MR analysis confirmed that the genetic predicted circulating levels of MCP1 were associated with an increased risk of breast cancer, and the risk of breast cancer increased by 0.20 times with an increase of 23.7 pg/ml in MCP1. Conclusion: Genetic variants and circulating levels of MCP1 are significantly associated with the risk of breast cancer and can be used as a biomarker for early prediction of breast cancer.

[Proteinuria associated with hookworm infection: a case report]

As a common soil-borne nematode, hookworm is mainly parasitized in the intestine, and the clinical manifestations of hookworm infections mainly include gastrointestinal symptoms and iron-deficiency anemia. In addition, hookworm may be also parasitized in other organs in addition to gastrointestinal system, resulting in development of disorders in other systems. Proteinuria caused by hookworm infections is rare and easy to be misdiagnosed in clinical practices. Hereby, the diagnosis and treatment of a case of proteinuria associated with hookworm infections was reported, in order to increase the understanding of hookworm infection-associated proteinuria among clinicians.

[Clinical and genetic studies on 76 patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria]

Objective: To analyze the clinical features, genetic characteristics, treatment and follow-up results of patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria, and to discuss the optimal strategies for assessing and treating such patients. Methods: From January 1998 to December 2020, 76 patients with hydrocephalus due to methylmalonic acidemia combined with homocysteinuria in the Department of Pediatrics in 11 hospitals including Peking University First Hospital were diagnosed by biochemical, genetic analysis and brain imaging examination. The patients were divided into operation-group and non-operation-group according to whether they underwent ventriculoperitoneal shunt. The clinical features, laboratory examinations, genotype, and follow-up data were retrospectively analyzed. Data were compared between the two groups using rank sum test, and categorical data were compared using χ² test. Results: Among the 76 patients (51 male, 25 female), 5 were detected by newborn screening, while 71 were diagnosed after clinical onset, 68 cases (96%) had early-onset, 3 cases (4%) had late-onset. The most common clinical manifestations of 74 cases with complete data were psychomotor retardation in 74 cases (100%), visual impairment in 74 cases (100%), epilepsy in 44 cases (59%), anemia in 31 cases (42%), hypotonia or hypertonia in 21 cases (28%), feeding difficulties in 19 cases (26%) and disturbance of consciousness in 17 cases (23%). Genetic analysis was performed in 76 cases, all of whom had MMACHC gene variations, including 30 homozygous variations of MMACHC c.609G>A. The most common variations were c.609G>A (94, 62.7%), followed by c.658_660del (18, 12.0%), c.567dupT (9, 6.0%) and c.217C>T (8, 5.3%). Therapy including cobalamin intramuscular injection, L-carnitine and betaine were initiated immediately after diagnosis. A ventriculoperitoneal shunt operation was performed in 41 cases (operation group), and 31 patients improved after metabolic intervention (non-operation group). There was no significant difference in the age of onset, the age of diagnosis, the blood total homocysteine, methionine, and urinary methylmalonic acid concentration between the two groups (all P>0.05). The symptoms of psychomotor development, epilepsy, and visual impairments improved gradually after a long-term follow-up in the operation group. Conclusions: Hydrocephalus is a severe complication of methylmalonic acidemia combined with homocysteinuria. The most common clinical manifestations are psychomotor retardation, visual impairment, and epilepsy. It usually occurs in early-onset patients. Early diagnosis and etiological treatment are very important. Hydrocephalus may improve after metabolic intervention in some patients. For patients with severe ventricular dilatation, prompt surgical intervention can improve the prognosis.

[Analysis of respiratory syncytial virus detection outcomes of 973 cases with severe respiratory infection during 2016-2019, Yuhang district of Hangzhou]

This study collected nasopharyngeal swab specimens from severe respiratory infection cases in First People's Hospital of Yuhang District during 2016-2019. Real-time PCR was used to detect respiratory syncytial virus (RSV). Rate of RSV positive detection were analysised in different age groups and different months. A total of 973 nasopharyngeal swab specimens of severe respiratory infection cases were collected, and the total positive rate of nucleic acid test of RSV was 6.47%; The detection rate of nucleic acid in male is higher than that in female, with no statistical differences (P=0.023). The positive rate of nucleic acid test was negatively correlated with age. The positive rate was 15.2% in the group aged 0-1 years and 12% in the group aged 1-2 years. There are obvious seasonal differences in the prevalence of RSV, human are easier to infect RSV in spring and winter.

[The phenotypes and genotypes in 314 patients with isolated methylmalonic acidemia]

Objectives: To summarize the clinical and genetic characteristics of the patients with isolated methylmalonic acidemia and investigate the strategies for the diagnosis, treatment and prevention. Methods: Three hundred and fourteen patients (180 males, 134 females) with isolated methylmalonic acidemia were ascertained from 26 provinces or cities across the mainland of China during January 1998 to March 2020. Genetic analysis was performed by Sanger sequencing, gene panel sequencing, whole exome sequencing, multiplex ligation-dependent probe amplification or quantitative PCR. According to the age of onset, the patients were divided to early-onset group (≤12 months of age) and the late-onset group (>12 months of age). They were treated by cobalamin, L-carnitine and (or) special diet and symptomatic treatment. Statistical analysis was done using Chi-square test. Results: Fifty-eight of 314 (18.5%) patients were detected by Newborn screening using liquid chromatography tandem mass spectrometry. Five cases (1.6%) had a postmortem diagnosis. Two hundred and fifty-one patients (79.9%) were clinically diagnosed with an age of onset ranged from 3 hours after birth to 18 years. One hundred and fifty-nine patients (71.0%) belonged to early-onset groups, 65 patients (29.0%) belonged to the late-onset group. The most common symptoms were metabolic crises, psychomotor retardation, epilepsy, anemia and multiple organ damage. Metabolic acidosis and anemia were more common in early-onset patients than that in late-onset patients (20.8%(33/159) vs. 9.2% (6/65), 34.6% (55/159) vs. 16.9% (11/165), χ(2)=4.261, 6.930, P=0.039, 0.008). Genetic tests were performed for 236 patients (75.2%), 96.2%(227/236) had molecular confirmation. One hundred and twenty-seven variants were identified in seven genes (MMUT, MMAA, MMAB, MMADHC, SUCLG1, SUCLA2, and MCEE), of which 49 were novel. The mut type, caused by the deficiency of methylmalonyl-CoA mutase, was the most common (n=211, 93%) cause of this condition. c.729_730insTT, c.1106G>A and c.914T>C were the three most frequent mutations in MMUT gene. The frequency of c.914T>C in early-onset patients was significantly higher than that in late-onset patients (8.3% (18/216) vs. 1.6% (1/64), χ(2)=3.859, P=0.037). Metabolic crisis was more frequent in mut type than the other types (72.6% (114/157) vs. 3/13, χ(2)=13.729, P=0.001),developmental delay and hypotonia were less frequent in mut type (38.2% (60/157) vs. 9/13, 25.5% (40/157) vs. 8/13, χ(2)=4.789, 7.705, P=0.030, 0.006). Of the 58 patients identified by newborn screening, 44 patients (75.9%) who were treated from asymptomatic phase developed normally whereas 14 patients (24.1%) who received treatment after developing symptoms exhibited varying degrees of psychomotor retardation. Conclusions: The characteristics of phenotypes and genotypes among Chinese patients with isolated methylmalonic acidemia were analyzed. Expanded the mutation spectrum of the associated genes. Because of the complex clinical manifestations and severe early onset of isolated methylmalonic acidemia, Newborn screening is crucial for early diagnosis and improvement of prognosis. MMUT gene is recommended for carrier screening as an effort to move the test earlier as a part of the primary prevention of birth defects.

[Jiangsu Province Coronary Artery Bypass Grafting Registry study: a report of 4 661 patients in 13 centers]

Objective: To examine the overall status of the Jiangsu Province Coronary Artery Bypass Grafting Registry database. Methods: The patients date of Jiangsu Province Coronary Artery Bypass Grafting Registry database from October 2017 to December 2019 was collected retrospectively.Risk factors, history, cardiac function (New York Heart Association class), extent of coronary artery lesion, European system for cardiac operative risk evaluation Ⅱ (EuroSCORE Ⅱ), cardiopulmonary bypss, arterial grafts, the numbers and flow of grafts and postoperative major adverse cardiac and cerebrovascular event(MACCE) information were analyzed. The clinical data of patients underwent on-pump CABG(ONCABG) or off-pump CABG (OPCAB) were compared by t test or χ(2) test. Results: Up till December 2019, the database enrolled 7 138 patients, in which 4 661 patients receiving primary isolated CABG. There were 3 486 males and 1 175 females with the age of (64.6±8.1) years (range:31 to 87 years). There were coronary left main disease in 960 patients, triple vessel disease in 3 934 patients, both left main and triple vessel disease in 837 patients, ejection fraction>50% in 3 841 patients, cardiac function class Ⅲ to Ⅳ in 1 664 patients. EuroSCORE Ⅱ was (2.3±0.7)% (range: 0.5% to 35.8%). There were 2 731 patients (58.59%) underwent ONCABG and 1 930 patients (41.41%) underwent OPCAB. There were 4 144 patients (88.91%) for whom the left internal thoracic artery was harvested. Seven centers (2 centers routinely) used left radial artery, 5 centers (3 centers routinely) used the transit time flow meter. The graft was 3.4±0.7 (range:1 to 7), the aortic crossclamp time was (65.0±20.4) minutes (range: 21 to 196 minutes), the cardiopulmonary bypass time was (90.0±24.2) minutes (range: 33 to 227 minutes). In-hospital death ocurred in 84 patients(1.80%), while re-operation in 93 patients (2.00%), myocardial infarction in 71 patients (1.52%), cerebral infarction in 33 patients (0.71%) and dialysis in 56 patients (1.20%). There were 2 936 patients prescribed with secondary prevention drugs(62.99%).Comparing with OPCAB group, ONCABG group had younger age, more female, more diabetes mellitus, more history of myocardial infarction and percutaneous transluminal coronary angioplasty, poorer cardiac function and coronary lesions, higher EuroSCORE Ⅱ, preoperatively (all P<0.05), and was associated with higher MACCE (135/2 731 vs. 71/1 930, χ(2)=4.280, P=0.039), and of more grafts, transfusion and intra-aortic balloon counterpulsation application (all P<0.05). Conclusions: Jiangsu Province Coronary Artery Bypass Grafting Registry database is generally in good operation, and some parameters still need to be improved. Comparing with OPCAB group, ONCABG has more severe preoperative general conditions, while the outcomes is acceptable.

MicroRNA-421 inhibits caspase-10 expression and promotes breast cancer progression

Breast cancer is one of the most prevalent and fatal diseases around the world. The mechanism of tumorigenesis in breast cancer remains to be clarified. miR-421 plays an oncogenic role in many cancers. Although, the clinical significance of miR-421 in patients with breast cancer is still to be investigated. Caspase-10 is one of the initiator of apoptosis. But the relationship between miR-421 and caspase-10 has not been investigated. In the present study, we found that miR-421 was expressed much higher in breast cancer tissues compared to those in adjacent non-tumor tissues. Furthermore, miR-421 promotes cell proliferation and colony formation in vitro. miR-421 inhibits cell apoptosis probably through restraining caspase-10 expression. Thus, miR-421 might be a potential diagnostic maker and therapeutic target for breast cancer.

Remote sensing image segmentation based on a robust fuzzy C-means algorithm improved by a parallel Lévy grey wolf algorithm

Due to the insufficient use of local information, the traditional fuzzy C-means (FCM) algorithm and its extension algorithm combined with spatial information show poor robustness and low segmentation accuracy. In addition, in the process of image segmentation based on the FCM algorithm, the initial center estimation is regarded as the process of searching the appropriate value in the gray range. To solve these problems, a new robust algorithm is proposed in this paper. The algorithm searches the optimal initial center by introducing an improved parallel Lévy grey wolf optimization algorithm, which is an improved fuzzy C-means segmentation algorithm that combines local information and adaptive gray weighting. Experimental results infer that both the precision and efficiency of the proposed method are superior to those of the state-of-arts.

[The impact of male circumcision on the natural history of genital HPV infection: a prospective cohort study]

Objective: To analyze the correlation between circumcision and incidence and clearance of male genital HPV infection. Methods: From May to July 2014, 18-55 year old men who had sexual behavior history were recruited from the general population in Liuzhou, Guangxi to set up a cohort. Totally, 113 circumcised and 560 uncircumcised men were enrolled and interviewed using a questionnaire (including information on demographic characteristics and sexual behaviors), then they were followed-up with 6-month interval for 2 times. On each visit, specimens of male external genitalia were collected and genotyped for HPV DNA. The differences of incidence and clearance of genital HPV infections between circumcised and uncircumcised men were analyzed by Log-rank test. Cox regression was used to analyze the relationship between circumcision and incidence and clearance of HPV infection. Results: The median age (P(25), P(75)) of circumcised and uncircumcised men were 28 (24, 35) and 32 (24, 31), respectively. The incidences of any HPV infections were 9.1 (95%CI: 2.4-15.7) and 8.4 (95% CI: 5.6-11.2) per 1 000 person-months (χ(2)=0.10, P=0.758), respectively. The clearance of circumcised men [136.3 (95%CI: 70.0-202.7) per 1 000 person-months] was higher than that in uncircumcised men [89.6 (95%CI: 65.9-113.3) per 1 000 person-months] (χ(2)=8.19, P=0.004). In multivariate COX regression analysis, compared with uncircumcised men, circumcised men had higher possibility to clear any HPV infections (HR: 2.41, 95%CI: 1.30-4.46). Compared with men having one sexual partner, people having more than 4 sexual partners had lower possibility to clear any HPV infections (HR: 0.49, 95%CI: 0.25-0.96). Compared with 18-25 years old men, men aged 26-35 years old had higher possibility to clear high-risk HPV infections (HR: 2.14, 95%CI: 1.08-4.23). Conclusion: Circumcised and uncircumcised men had similar incidence of genital HPV infection, whereas, men conducted circumcision and having fewer sexual partners could increase the clearance of genital HPV infections.

[Prevalence of type-specific human papillomavirus infection among 18-45 year-old women from the general population in Liuzhou, Guangxi Zhuang Autonomous Region: a cross-sectional study]

Objective: To analyze the type-specific prevalence of human papillomavirus (HPV) among women aged 18-45 years from the general population in Liuzhou, Guangxi Zhuang Autonomous Region. Methods: Totally, 2 300 women aged 18-45 years old were enrolled in Liuzhou,from March to July, 2013. Cervical exfoliated cells were collected for liquid based cytological and HPV DNA tests. Women were referred to colposcopy exam, based on the clinical practice guideline. Results: Overall, the prevalence rates of any HPV or oncogenic HPV appeared as 22.7% (95% CI: 21.0%-24.4%) and 17.3% (95% CI: 16.0%-19.1%), respectively in this population under study. The high-risk HPV prevalence peaked at the age groups of 18-25 and 41-45, increasing along with the severity through cytological and histological tests. Statistically significant differences between the prevalence of CIN2+ (Cervical intraepithelial neoplasia 2+) in women older than 26 years (1.7%, 95% CI: 1.0%-2.4%) and 18-25 years (1.2%, 95% CI: 0.5%-1.9%) of age, were not observed. Among samples diagnosed as CIN2+, positivity of HPV bivalent (16/18) and nine-valent (6/11/16/18/31/33/45/52/58) vaccine, related high risks on the types of HPV types appeared as 44.1% and 97.1%. Conclusions: The age-specific HPV prevalence rates in the general women aged 18-45 in Liuzhou presented as having bimodal distribution, suggesting that the disease burden of cervical diseases in women aged 26-45 years should not be ignored. Nine-valent HPV vaccine might provide more effective prevention outcomes on cervical cancer in China.

[Analysis for protection rate and antibody levels of epidemic cerebrospinal meningitis among children aged between 3-23 months in Liuzhou, in 2012]

Objective: To understand the level of bactericidal antibodies against Neisseria meningitidis and their rate of protection in children aged between 3 and 23 months, in Liuzhou, in 2012. Methods: Convenience sampling was performed in Liujiang, Rong'an and Sanjiang Counties from May through August, 2012. The inclusion criteria for 603 subjects were: Children aged between 3 and 23 months; no history of meningococcal meningitis; no vaccination against Neisseria meningitidis serogroup C; more than 30 days from the last vaccination against Neisseria meningitidis serogroup A. Demographic information and immunization history of the subjects were obtained using questionnaires. Venous blood samples (2.0 ml each) were collected and levels of Neisseria meningitides antibodies determined using a Serum Bactericidal Assay (SBA). The geometric mean titer (GMT) of serum bacterial antibodies was positive when it was greater than or equal to 1∶2 and protective when greater than 1∶8. Chi-square and Fisher's exact tests were used to compare differences in the positive and protective rates of serum antibodies of Neisseria meningitidis serogroup A and Neisseria meningitidis serogroup C, among children with different demographic characteristics. Kruskal-Wallis H test was used to compare differences in the GMT of serum antibodies of Neisseria meningitidis serogroup A and Neisseria meningitidis serogroup C, among children with different demographic characteristics. Results: Of 603 subjects, 325 (53.9%) were female and 278 (46.1%) were male; 276 (45.8%), 143 (23.7%) and 184 (30.5%) subjects were administered, respectively, no treatment, 1 dose vaccine and 2 doses vaccine. The GMT of serum antibodies against group A Neisseria meningitidis was 1∶1.11, the positive rate was 7.6% (46) and the protective rate was 2.0% (12). The GMT of antibodies in children receiving 1 vaccine dose was 1∶1.16 and the protective rate was 3.5% (5), both values higher than those in children receiving 2 vaccine doses (GMT: 1∶1.2, protective rate: 3.5% (5)). However, these differences were not statistically significant (GMT: H=0.64, P=0.728; protective rate: Fisher's exact test, P= 0.080). The GMT of antibodies in children receiving 1 and 2 doses of meningococcal polysaccharide vaccines were 1∶1.12 and 1∶2.30, respectively (≤180 d). The GMT of serum antibodies for group C meningococcal vaccine was 1∶1.18 and its positive and protective rates were 14.6% (88) and 2.2% (13), respectively. Conclusion: Children aged between 3 and 23 months are susceptible to Neisseria meningitidis groups A and C. The immune effectiveness of group A meningococcal polysaccharide vaccine is relatively poor in this age group and their antibody levels decreased rapidly.

[Two cases with generalized intracranial calcification due to hereditary folate malabsorption and literature review]

Objective: This study aimed to investigate the clinical, biochemical and genetic features of two Chinese children with hereditary folate malabsorption. Method: Clinical features, laboratory examinations, treatment and SLC46A1 gene of two cases were studied. Reports on hereditary folate malabsorption utill September of 2016 were searched and the clinical and genetic characteristics of reported cases were summarized. Result: The two patients presented with megaloblastic anemia from their infant period and seizures, psychomotor retardation and regression. In case1, mean corpuscular volume (MCV) was 100 fl. Serum folate was 9.96 nmol/L. Folate and 5-methylenetetrahydrofolate in cerebrospinal fluid were 0 and 0.01 separately. In case 2, MCV was 93.9 fl. Serum folate was 4.49 nmol/L. The concentration of folate and 5-methylenetetrahydrofolate in cerebrospinal fluid were both zero. On their brain CT, progressive bilateral symmetrical calcification was observed. On their SLC46A1 gene, four mutations were identified. Case 1 had one novel mutation, c. 1238T>C (L413P) and c. 194-195insG (p.Cys66LeufsX99). From Case 2, two reported mutations, c. 1A>T (M1L) and c. 194-195insG (p.Cys66LeufsX99) were identified. The administration of folinic acid (60 to 120 mg per day) was initiated after diagnosis. Clinical improvement and normalized hematologic markers were observed after treatment. Totally 37 cases were reported in reviewed English literature, including 30 cases with mutations on SLC46A1 gene (only one Chinese patient). All the cases had the onset in infancy. The ratio of boys to girls was 1 to 1.5. Main manifestations were characterized by megaloblastic anemia (77%), failure to thrive (50%), diarrhea (27%), psychomotor retardation (63.6%), epilepsy (27%), and infection of respiratory system (45.5%). The concentration of folate in both serum and cerebrospinal fluid was decreased (72.7% and 63.6% respectively). Hypoimmunoglobulinemia accounted for 27.3%. Most of mutations in HFM were distributed between p. 65 and p. 68 (c.194-c.204), mainly due to insertion- or deletion-related frame shifts or generation of stop codons. Oral and parenteral folinic acid treatment was effective. Conclusion: Hereditary folate malabsorption often presented with megaloblastic anemia, abnormalities of digestive and nervous system, and hypoimmunoglobulinemia with recurrent infections. Low level of serum and CSF folate and screening SLC46A1 gene are keys to the etiologic study of the patients. Early supplement with folinic acid is beneficial to the prognosis.

[Effect of lumbar dorsal muscle injuries on lumbar vertebral bone quality of rat]

Objective: To explored the effects of lumbar dorsal muscle damage on local lumbar vertebral bone quality. Methods: Thirty SD female rats, at age of 20 weeks, were randomly divided into three groups: control group, or say pseudo surgery group, an incision in the back were performed as CNT; bilateral erector spinal muscle group in which group bilateral lumbar erector spinal muscle were removed as RESM; castration group in which bilateral ovaries were resected as OVX.After three months, bone mineral density, microscopic CT and vertebral compression test were taken in lumbar vertebral (L4-6) in turn. Results: After three months bone mineral density in RESM group was obviously lower than the control group [(0.211±0.028) g/cm² vs(0.253±0.021) g/cm², P<0.01], however, there was no significant difference between OVX and RESM[(0.197±0.015) g/cm² vs(0.211±0.028) g/cm², P>0.05]. In microscopic CT three-dimensional reconstruction and bone histomorphometry analysis, compared with control group CNT , in the experimental groups OVX and RESM, bone trabecula of vertebral bodies were more sparse, the overall number and interconnection of trabecula were less.Especially in the OVX, osteoporotic trend of trabecular network trend is more obvious.In vertebral compression test, the maximum load, energy absorption, the maximum stress and elastic modulus in both OVX and RESM were significantly reduced (P<0.01). In the RESM the above four biomechanical parameters were significantly higher than those of OVX (P<0.05). Conclusion: Integrity and vigor of paravertebral muscles would be of great significance to maintain adjacent vertebral bone quality.Resection of lumbar dorsal muscles could lead to a significant decrease of local vertebral bone quality.Damage and atrophy of lumbar dorsal muscle could cause osteoporosis of vertebral bodies.

[Frequency and clinical features of ASXL2 gene mutation in acute myeloid leukemia patients with AML1- ETO fusion gene positive]

目的

探讨伴AML1-ETO融合基因的急性髓系白血病（AML）患者ASXL2基因突变情况、突变阳性患者临床特征及ASXL2基因突变与c-kit基因突变的关系。

方法

采用PCR扩增产物片段直接测序分析法，检测59例伴AML1-ETO融合基因初发AML患者ASXL2基因第11、12外显子编码区突变情况，比较ASXL2基因突变阳性和阴性组患者的临床特征、生存及c-kit基因突变情况。

结果

59例患者中7例存在ASXL2突变，突变率为11.9%。ASXL2基因突变阳性组患者初诊时外周血红蛋白浓度中位数为56.2（38.0~72.0）g/L，显著低于ASXL2突变阴性组患者的69.0（37.2~154.0）g/L，差异有统计学意义（P=0.038）；外周血WBC、PLT、嗜酸粒细胞比例、骨髓原始细胞比例与ASXL2突变阴性组相比，差异均无统计学意义（P值均>0.05）。两组均未见肝、脾、中枢神经系统浸润；淋巴结不同程度肿大，但ASXL2基因突变阳性、阴性两组间差异无统计学意义（P=0.859）。免疫表型分析显示：ASXL2基因突变阳性组CD33表达显著低于阴性组（P=0.033）；两组患者均未表达cCD3，CD117、cMPO、HLA-DR、CD34、CD38、CD13、CD44、CD15、CD64、CD11b、CD56、CD19、cCD79a、CD7两组表达差异均无统计学意义（P值均>0.05）。ASXL2基因突变阳性与阴性组患者总缓解率、总生存时间差异均无统计学意义（P值分别为0.577、0.631）。两组c-kit基因突变检出率分别为14.3％和29.4%，差异无统计学意义（P=0.697）。

结论

该组伴AML1-ETO融合基因AML患者ASXL2基因突变率为11.9%。ASXL2突变阳性患者外周血红蛋白浓度、CD33表达方面呈现一定的临床特征。ASXL2基因突变与c-kit基因变突可能没有特定的关联性。

[Stereotactic brain biopsy guided by iMRI co-registration combined with PET/CT]

OBJECTIVE

To explore the clinical value of intraoperative magnetic resonance imaging (iMRI) coregistration combined with position emission tomography/computed tomography (PET/CT) in stereotactic brain biopsy.

METHODS

Forty nine patients with intracranial lesions were operated by stereotactic biopsy from June 2010 to June 2015 in Tianjin Medical University General Hospital. Seventeen patient's operation was guided by iMRI only (group A), thirty two patients' operation was guided by iMRI and PET/CT (group B). The diagnosis success rate and operation related complications were compared between the two groups.

RESULTS

PET/CT and iMRI were integrated successfully in all cases of group B. Fourteen patients (82.4%) of group A and all 32 patients (100%) of group B had final diagnosis confirmed by histopathological and immunohistochemical observation. The diagnosis success rate of group B was higher than group A (P<0.05). There were 5 patients in total who had postoperative complication, 2 (11.8%) in group A and 3 (9.3%) in group B, but the difference was not statistically significant.

CONCLUSIONS

PET/CT based metabolic imaging can be automatically integrated with standard MRI guided stereotactic biopsy. Compared with iMRI only, the combined treatment improves diagnosis success rate without increasing complications; it's safe, and has high clinical efficacy.

Plastic responses in the metabolome and functional traits of maize plants to temperature variations

Environmentally inducible phenotypic plasticity is a major player in plant responses to climate change. However, metabolic responses and their role in determining the phenotypic plasticity of plants that are subjected to temperature variations remain poorly understood. The metabolomic profiles and metabolite levels in the leaves of three maize inbred lines grown in different temperature conditions were examined with a nuclear magnetic resonance metabolomic technique. The relationship of functional traits to metabolome profiles and the metabolic mechanism underlying temperature variations were then explored. A comparative analysis showed that during heat and cold stress, maize plants shared common plastic responses in biomass accumulation, carbon, nitrogen, sugars, some amino acids and compatible solutes. We also found that the plastic response of maize plants to heat stress was different from that under cold stress, mainly involving biomass allocation, shikimate and its aromatic amino acid derivatives, and other non-polar metabolites. The plastic responsiveness of functional traits of maize lines to temperature variations was low, while the metabolic responsiveness in plasticity was high, indicating that functional and metabolic plasticity may play different roles in maize plant adaptation to temperature variations. A linear regression analysis revealed that the maize lines could adapt to growth temperature variations through the interrelation of plastic responses in the metabolomes and functional traits, such as biomass allocation and the status of carbon and nitrogen. We provide valuable insight into the plastic response strategy of maize plants to temperature variations that will permit the optimisation of crop cultivation in an increasingly variable environment.

Development of polymorphic SSR markers in the razor clam (Sinonovacula constricta) and cross-species amplification

Next-generation sequencing provides large-scale sequencing data with relative ease and at a reasonable cost, making it possible to identify a large amount of SSR markers in a timely and cost-effective manner. On the basis of the transcriptome database of Sinonovacula constricta obtained by Illumina/Solexa pyrosequencing, 60 polymorphic SSR markers were developed and characterized in 30 individuals. The number of alleles per polymorphic locus ranged from 2 to 7 with an average of 3.75 alleles. The observed and expected heterozygosities varied from 0.050 to 1.000 and from 0.050 to 0.836, respectively. Nineteen loci significantly deviated from Hardy-Weinberg equilibrium (P < 0.01) after Bonferroni's correction for multiple tests. In addition, interspecific transferability revealed that 20 polymorphic loci in Solen linearis were first characterized in this study. To the best of our knowledge, this is the highest number of SSRs in S. constricta and the first report of cross-species amplification. These novel polymorphic SSR markers will be particularly useful for conservation genetics, evolutionary studies, genetic trait mapping, and marker assisted selection in the species.

Hydroxycamptothecin shows antitumor efficacy on HeLa cells via autophagy activation mediated apoptosis in cervical cancer

OBJECTIVES

To investigate the effect and the mechanism of anti-tumor agent hydroxycamptothecin (HCPT) on HeLa cells in cervical cancer.

MATERIALS AND METHODS

Autophagy and apoptosis were detected by western blotting and the transfection of GFP-LC3 shRNA as well as Hoechst staining.

RESULTS

The authors found that the expression of the regulators of Beclin-1, p62, and microtubule-associated protein 1 light chain 3 (LC3) upregulated and then triggered the occurrence of cell autophagy. On the other hand, HCPT could induce to the formation of autophagy and resulted in cell apoptosis after autophagy.

CONCLUSION

HCPT can alter cell autophagy and then trigger cell apoptosis to achieve antitumor effects.

Metabolic response of maize plants to multi-factorial abiotic stresses

Clarification of the metabolic mechanisms underlying multi-stress responses in plants will allow further optimisation of crop breeding and cultivation to obtain high yields in an increasingly variable environment. Using NMR metabolomic techniques, we examined the metabolic responses of maize plants grown under different conditions: soil drought, soil salinity, heat and multiple concurrent stresses. A detailed time-course metabolic profile was also performed on maize plants sampled 1, 3 and 7 days after initiation of soil drought and heat stress. The metabolic profile of maize plants subjected to soil drought was more similar to plants exposed to salt stress than to heat-stressed plants. Drought-stressed maize plants subjected to salt or heat stress showed distinct integrated metabolic profiles compared with those exposed to either stressor individually. These differences show the considerable metabolic plasticity of maize in response to different growth conditions. Moreover, glucose, fructose, malate, citrate, proline, alanine, aspartate, asparagine, threonine and one unknown compound fluctuated obviously between maize plants grown in controlled growth cabinet and a natural regime. These changes were associated with the TCA cycle and core nitrogen metabolism, and could be related to their multiple functions during plant growth. The evident stress-induced trajectory of metabolic changes in maize indicated that the primary metabolic responses to soil drought, heat and combined drought and heat stresses occurred in a time-dependent manner. Plasticity at the metabolic level may allow maize plants to acclimatise their metabolic ranges in response to changing environmental conditions.

Effect of siRNA targeting HER2/neu on the proliferation and viability of prostate cancer PC-3M cells

The aim of this study was to investigate the effect of a small interfering RNA (siRNA) targeting human epidermal growth factor receptor 2 (HER2/neu) on the proliferation and viability of prostate cancer PC-3M cells. Chemically synthesized siRNA targeting HER2/neu was transfected into PC-3M cells by using liposomes, and cells transfected with empty liposomes, a negative siRNA sequence, or nothing (untransfected) were used as controls. mRNA and protein levels of HER2/neu were detected using reverse transcription-polymerase chain reaction and western blot, respectively. The inhibitory action of HER2/neu siRNA on the in vitro growth of PC-3M cells was assessed by the cholecystokinin 8 assay and apoptosis was detected using flow cytometry. Cells transfected with HER2/neu siRNA showed decreased mRNA and protein levels of HER2/neu compared to control groups (P < 0.05). The survival rate of PC-3M cells decreased significantly after transfection with HER2/neu siRNA compared to that of untransfected cells (55.39 ± 1.60 and 81.42 ± 0.80%, respectively; P < 0.05). The apoptosis rate in cells transfected with HER2/neu siRNA was quite high (45.60 ± 0.70%) compared to that of blank control, empty liposome, and negative siRNA sequence groups (P < 0.05). In conclusion, siRNA targeting HER2/neu inhibits HER2/neu expression in PC-3M cells, resulting in an inhibition in proliferation and an induction of apoptosis.

In vivo toxicity of nano-alumina on mice neurobehavioral profiles and the potential mechanisms

The rapid development and expanding applications of nanotechnology have led to enhanced exposure of human body to nanoparticles. It is, therefore, necessary to address the safety issue via rigorous toxicological evaluation and to understand the underlying interaction mechanism. However, only a few studies to date have evaluated the safety of nano-sized materials and their potential adverse effects on biological systems. In this study, we sought to investigate the potential toxicity of aluminum oxide (alumina) nanoparticles in ICR strained mice, focusing on potential neurobehavioral defects and the possible mechanisms. The results demonstrated that nano-alumina impaired neurobehavioral functions, including lengthened escape latency, shorter time spent in the target quadrant and reductions in the number of platform crossing. In addition, it induced cell necrosis and apoptosis, which were likely mediated by the reduction of MMP and ROS, and the induction of the caspase-3 gene. Our results implicated that mitochondrial impairment plays a key role in neurotoxicity of nano-alumina, sequent oxidative damage and neural cell loss, especially necrosis, may be direct causes for the neurobehavioral defects. Collectively, nano-alumina presents a strong pro-cell death effect on ICR mice in vivo, suggesting that nano-alumina may serve as an inducer for neural toxicology. Findings in the present study indicating that surface chemical characteristics and nanoscale sizes of nano-alumina could co-contribute significantly to neurotoxicity. The impaired neurobehavioral patterns indicate that nano-alumina particles are more toxic to the cerebrum than those of nano-carbon with the same nanoparticle size and micro-alumina with the same surface chemical characteristics.

Congenital lumbosacral limb duplication: a case report

We report a case of congenital lumbosacral limb duplication at the pelvis, lower limb, and foot of a 4-year-old boy. The patient presented with a supernumerary lower limb joined at the lumbosacral region by a bony connection. A pseudo-navel and a pseudo-penis were found on the supernumerary limb and foot duplication was noted at the end. Radiography and a 3-dimensional computed-tomography reconstruction revealed duplication of an inversely oriented pelvis dorsal to the normal pelvis, semi-vertebrae in T7 to T9, thoracolumbar scoliosis, lumbosacral vertebral dysplasia, and dislocation of the left hip. Magnetic resonance imaging demonstrated a tethered spinal cord and an adipoma in the sacral canal. Motor conduction velocity was reduced in the left peroneal nerve. Surgery to remove the supernumerary limb was successfully performed. The patient recovered well and further surgery is planned for functional reconstruction of the left lower limb.

Anti-proliferative Effects of Oridonin on SPC-A-1 Cells and its Mechanism of Action

Oridonin, an extract from the Chinese herb Rabdosia rubescens, is currently one of the most important traditional Chinese herbal medicines. We investigated the anti-proliferative effect of oridonin on the lung cancer cell line SPC-A-1 and its mechanism of action. Growth inhibition was measured using a microculture tetrazolium assay and apoptosis was measured by several standard methods. Western blot analysis measured the expression of bcl-2 and bax proteins. Oridonin (> 28 μmol/l) inhibited the growth of SPC-A-1 cells and induced apoptosis. Marked morphological changes indicative of apoptosis were observed, especially in cells treated with oridonin for 48–60 h. Western blot analysis revealed downregulation of bcl-2 and upregulation of bax proteins following treatment with oridonin for 48 h. We conclude that oridonin demonstrated anti-proliferative and apoptosis-inducing effects on SPC-A-1 cells in vitro, and that changes in bcl-2 and bax protein levels may play an important role in its mechanism of action.

Nanoscale analysis of biofunctional molecules and components

In basic medical research, as well as in concrete clinical applications, the nanoscale analysis of biofunctional units is of strongly increasing relevance. Dedicated investigations on molecules, molecular composites or functional units can efficiently be performed ex or in situ by scanning probe methods and, namely, by scanning force microscopy. In the following investigations, the folding behavior of DNA is presented as an example of basic research in medicine. In contrast, the investigation of bioadsorption phenomena in systems on which apheresis therapies are based provides a real contribution to applied medicine.

[Allografting for massive bone defect: bone and soft tissue reconstruction and postoperative rehabilitation]

OBJECTIVE

To evaluate the results of limb function and the methods of bone and soft tissue reconstruction of patients treated with allografting.

METHODS

From May 1992 to January 1999, 90 patients suffered from bone malignant tumor were treated with allografting in different methods of internal fixations. The average follow-up was 37.5 months. The limb postoperative function, complications related to different surgical methods were compared according to Enneking evaluation system.

RESULTS

Skin necrosis, infection, non-union, fracture of allograft were the main complications which affect patients' limb postoperative functions. Of the 90 fresh-frozen allografting procedures, the final results of operation showed that hip joints and knee joints were better than the shoulder joints. More than 80% of the patients treated with interlocked intramedullary nail and allograft-prosthesis combination led to an over-all result that was excellent and good. Interlocked intermedullary nail was of recommended method of internal fixation. Early exercises of operative limbs could promote function recovery.

CONCLUSION

Using of interlocked intramedullary nail and allograft-prosthesis combination are of recommended operation method and can be applied with better results, and early exercises of operative limbs will lead to better functions.

[Resolution of overlapping mass spectra of azobiphenyl dyes by subwindow factor analysis technique]

Subwindow factor analysis(SWFA) has been proven to be an effective data processing technique. In this paper, it is applied to the resolution of overlapping GC-MS peaks. A two-component sample of azobiphenyl dyes (3,3'-dichlorobenzidine, 4,4'-methylene-bis-(2-chloroaniline)) was prepared and a data set from a mixture of azobiphenyl dyes recorded by GC-MS was obtained. Then the overlapping GC-MS data were resolved by SWFA. The results show that both mass spectrum and chromatogram of components can be resolved from multicomponent overlapping data. The resolved spectra were in good consistence with the mass spectra of standard samples. At the same time, overlapping GC-MS data were also resolved by WFA. In Comparing with WFA technique, SWFA is more convenient, and the speed of resolution could be increased.

The structure of the nucleosome core particle of chromatin in chicken erythrocytes visualized by using atomic force microscopy

The structure of the nucleosome core particle of chromatin in chicken erythrocytes has been examined by using AFM. The 146 bp of DNA wrapped twice around the core histone octamer are clearly visualized. Both the ends of entry/exit of linker DNA are also demonstrated. The dimension of the nucleosome core particles is approximately 1-4 nm in height and approximately 13-22 nm in width. In addition, superbeads (width of approximately 48-57 nm, height of approximately 2-3 nm) are occasionally revealed, two turns of DNA around the core particles are also detected.

Visualization of chromatin folding patterns in chicken erythrocytes by atomic force microscopy (AFM)

The organization of the higher order structure of chromatin in chicken erythrocytes has been examined with tapping-mode scanning force microscopy under conditions close to their native environment. Reproducible high-resolution AFM images of chromatin compaction at several levels can be demonstrated. An extended beads-on-astring (width of approximately 15-20 nm, height of approximately 2-3 nm for each individual nucleosome) can be consistently observed. Furthermore, superbeads (width of approximately 40 nm, height of approximately 7 nm) are demonstrated. Visualization of the solenoid conformation at the level of 30 nm chromatin fiber is attained either by using AFM or by using electron microscopy. In addition, tightly coiled chromatin fibers (approximately 50-60 nm and approximately 90-110 nm) can be revealed. Our data suggest that the chromatin in the interphase nucleus of chicken erythrocyte represents a high-order conformation and AFM provides useful high-resolution structural information concerning the folding pattern of interphase chromatin fibers.

[The surgical treatment of partial atrioventricular canal defect]

This paper reports 11 cases of partial atrioventricular canal defect in our hospital. It also discusses the diagnosis of complication prevention and treatment with patient and the disposal during operation term, emphasizes that once definite diagnosis has been made, operation must be taken as soon as possible. Skillfully grasp surgery anatomy and exact suture techniques is the key to avoid conduction damage.

Interaction between HMG proteins (1 + 2) and the negative regulatory region 1 (NCR1) in the 5'-flanking sequence of the human beta-globin gene

The pattern of high mobility group proteins 1 and 2 (HMG1,2) interaction with the 5'-flanking sequence of the human beta-globin gene has been analyzed by scanning tunnelling microscopy (STM). A 200 bp negative regulatory region in the 5'-flanking sequence of the human beta-globin gene can be folded by HMG proteins 1 and 2 into a circular structure (diameter 70 +/- 6 A) with a linear tail which seems to be a left-handed double helix structure.

Atomic force microscopy of uncoated plasmid DNA: nanometer resolution with only nanogram amounts of sample

Reproducible, high-contrast, nanometer-resolution AFM images of uncoated plasmid DNA can be obtained with nanogram quantities of DNA with the help of two advances in sample preparation: (1) Heating a DNA solution at 35 degrees C for 10 to 20 minutes before deposition on mica helps separate and spread the DNA, and (2) Using 5 microliter drops of the heated DNA solution in the concentration range of 2 to 10 nanogram/microliter in contact with a specially prepared mica surface for 5 to 10 minutes gives optimal coverage with only nanograms of DNA.

[Effects of 3 Chinese medical prescriptions on alkaline reflux gastritis in rats]

The experimental alkaline reflux gastritis in rats was established after 9 weeks of anastomosis between stomach and jejunum. The experiment shows that xiangsha liujunzi decoction, xiaochaihu decoction and dahuang gancao decoction all help to inhibit edema, hyperamia and extravasted blood, as well as depress inflammatory infiltration and hyperplasia. The number of intestinal metaplasia in the group treated with xiangsha liujunzi decoction is decreased. All the three prescriptions are not able to lower the contents of bile acid in the stomach.

An occupational hygiene survey in a Chinese viscose rayon factory

The retinopathy (microaneurysm/small dot hemorrhage) is an early and specific biological indicator to quantitatively evaluate the CS2 exposure. The appearance of retinal lesions was observed among Yugoslavian, German and American workers exposed to CS2. However, among Finnish CS2 workers a positive result was not obtained. We suggested a different response to CS2 exposure between two ethnic populations. We had an opportunity to do a cross-sectional medical and occupational hygiene survey in a Chinese rayon staple plant. Cross-sectional medical examinations failed to show any chronic CS2 effects on the Chinese workers.

Atomic force microscopy of single- and double-stranded DNA

A method has been developed for imaging single-stranded DNA with the atomic force microscope (AFM). phi X174 single-stranded DNA in formaldehyde on mica can be imaged in the AFM under propanol or butanol or in air. Measured lengths of most molecules are on the order of 1 mu, although occasionally more extended molecules with lengths of 1.7 to 1.9 mu are seen. Single-stranded DNA in the AFM generally appears lumpier than double-stranded DNA, even when extended. Images of double-stranded lambda DNA in the AFM show more sharp kinks and bends than are typically observed in the electron microscope. Dense, aggregated fields of double-stranded plasmids can be converted by gentle rinsing with hot water to well spread fields.

Parallel stranded DNA under the scanning tunnelling microscope

Using scanning tunnelling microscopy, we have directly observed parallel stranded DNA helixes of 43 nucleotides in length. The double helix is right-handed and has an average spacing, 17.43 A (+/- 1 S.D.: 2.30 A), and an average apparent depth, 4.79 A (+/- 1 S.D.: 1.04 A) for each groove. The average pitch of the helical turn is 34 A (+/- 1 S.D.: 3.35 A) and consists of no more than ten base pairs. The diameter of the helix is approx. 17-20 A. Our results provide direct evidence for the existence of a parallel structure of DNA in vitro and some details of its fine structure.

Conformation of DNA-DNA polymerase I complex observed by scanning tunneling microscopy

The conformation of a complex of a 41 mer/31 mer DNA fragment and the Klenow fragment of DNA polymerase I of Escherichia coli was studied by scanning tunnelling microscopy (STM). The results shows that near two turns of double helix of this DNA fragment was outside of enzyme while another part containing more than one turn of helix and 10 nucleotides single strand was combined with enzyme. The dimension and shape of DNA polymerase I (KF) in complex were different from that of free enzyme. The conformation of DNA-DNA polymerase I (KF) complex and the application of STM in studying structure of complex of DNA polymerase with DNA were discussed.

Determination of eight elements in six human cancer cell lines and two human normal cell lines by PIXE

Gastric, hepatic, and pulmonary cancer cell lines, and the third passage of normal gastric and pulmonary cell lines were analyzed by proton induced X-ray emission (PIXE) method. The contents of element Sr, Ca, Fe, Zn, P, K, Cu, and As in the cell lines were determined. The Sr, Ca, Fe, Zn, and As contents in cancer cell lines were significantly lower than those in the normal cell lines (p less than 0.05), whereas there were no significant differences for the P, K, and Cu contents (p greater than 0.1). The results suggest that the need of some essential elements has been diminished in cancer cell proliferation.

An epidemiological study on carbon disulfide angiopathy in a Chinese viscose rayon factory

To assess long-term vascular effects of occupational carbon disulfide (CS2) exposure, we examined 376 exposed and 325 unexposed Chinese workers with a medical and work-history questionnaire, a chest-pain questionnaire, blood pressure and blood cholesterol measurements, routine urinary tests, monochromatic fundus photography and other tests. Data from 354 exposed and 177 age- and sex-matched reference workers were evaluated. Personal exposure monitorings were performed simultaneously with a passive dosimeter using gas chromatography. Monochromatic fundus photography revealed no CS2-retinopathy characterized by microaneurysms and/or small dot hemorrhages, and no effects of CS2 on blood pressure and blood cholesterol were found. These negative results may have been due to the low daily exposure averages, which varied between 0.01 and 12.8, with a mean of 1.5 ppm. The present study suggested that the no-effect level of CS2 exposure on the development of retinopathy was around 2 ppm (8-h time weighted average), and the absence of adverse CS2 effects among the workers studied supported the current standard for occupational CS2 exposure of 10 mg m-3 in China.