[Epidemiological characteristics and spatiotemporal distribution of schizophrenia in Ningbo, 2018-2022].

Objective: To explore the temporal and spatial distribution characteristics of reported incidence of schizophrenia in Ningbo from 2018 to 2022 and to provide a scientific basis for rational allocation of mental health resources and comprehensive prevention and treatment of schizophrenia. Methods: The reported incidence data of schizophrenia from 2018 to 2022 were collected from Ningbo's mental health information management system, and the reported incidence was calculated by township. The spatial correlation analysis and the spatiotemporal scan analysis were used to study the spatiotemporal distribution of schizophrenia. Results: The reported incidence of schizophrenia decreased from 2018 to 2022, with 4 133 new cases reported, and the annual average reported incidence was 9.76/100 000. Global and local spatial autocorrelation analysis showed positive spatial correlations and hot spots in 2018-2020. The space-time scan analysis showed an incidence cluster in Dongqiao Town, Haishu District, during 2018-2019. The RR was 2.46, and the log-likelihood ratio was 256.89. Conclusions: The reported incidence of schizophrenia in Ningbo has obvious temporal and spatial aggregation, and the high incidence area explored can provide clues for further research on the correlation between environmental factors and the incidence of schizophrenia and has certain guiding significance for the rational allocation of mental health resources in Ningbo.

[Establishment and effect evaluation of nomogram model for diagnosis and prediction of pulmonary hypertension in patients with chronic obstructive pulmonary disease].

Objective: To construct a diagnostic and predictive model for chronic obstructive pulmonary disease complicated with pulmonary hypertension (COPD-PH) and evaluate its effect. Methods: A total of 1 514 COPD patients treated in 5 hospitals from January 1, 2014 to December 31, 2019 were retrospectively collected and divided into training cohort (1 072 cases) and validation cohort (442 cases) according to the ratio of 7∶3 according to the inclusion time. Data including demographic data, smoking status, history of disease, and clinical examination were collected through patient medical records and electronic medical record systems. Multivariate logistic regression models were used to explore the related factors of COPD-PH, and the nomogram model was constructed using the "rms" program package. The calibration curve was used to evaluate the consistency between the prediction probability of the model and the actual results. The C index and the area under the receiver operating characteristic curve (ROC) were used to evaluate the discrimination of the model. The decision curve analysis (DCA) was used to evaluate the clinical practicability of the model. Results: In the training cohort, 3.7%, 15.2% and 81.1% were aged 50-59, 60-69 and ≥70 years, respectively, which were significantly different from the age composition of the validation cohort (7.9%, 27.8% and 64.3%, respectively) (P=0.041). There was no significant difference between the training cohort (79.4%) and the validation cohort (84.6%) (P=0.243). Multivariate logistic regression analysis of the training cohort showed that age ≥70 years [OR (95%CI): 3.32 (1.49-7.36)] and smoking status [former (current) smoking, OR (95%CI)] were 3.67 (2.51-5.37) and 2.04 (1.44-2.90), respectively], NT-probNP≥1 400 ng/L[OR (95%CI): 9.88 (6.23-15.66)], right atrial diameter [OR (95%CI): 1.11 (1.07-1.15)] was COPD-related factors of PH, based on the above factors-PH nomogram COPD model was set up and develop for online tools (https://ph-666.shinyapps.io/zhonghua-PH/). The calibrated C index (95%CI) of the training cohort and the validation cohort were 0.82 (0.77-0.87) and 0.77 (0.68-0.86), respectively. The calibration curve was close to the diagonal in both the training cohort and the validation cohort. The AUC (95%CI) of the nomogram model was 0.82 (0.80-0.85) in the training cohort and 0.77 (0.73-0.82) in the validation cohort. ROC curve showed that the optimal threshold in the training cohort was 0.60, and the sensitivity and specificity under this value were 0.74 and 0.78, respectively; the optimal threshold for the validation cohort was 0.70, and the sensitivity and specificity under this value were 0.76 and 0.65, respectively. DCA analysis showed that the nomogram model provided better net benefits than the all-variable selection and no-variable selection strategies with threshold probabilities greater than 15.0% and 13.0% in the training and validation cohorts, respectively. Conclusions: The nomogram model for the diagnosis and prediction of COPD-PH is simple and accurate, which has a good clinical application prospect.

[Immunization efficacy and safety of Brucella 104M against aerosol challenge in BALB/c mice].

Objective: To evaluate the protective efficacy and safety of Brucella 104M against aerosol challenge in BALB/c mice and characterize its immunological effects. Methods: Female mice of 6-8 weeks old were immunized with Brucella abortus strain 104M by intratracheal aerosol delivery or intranasal instillation or subcutaneous injection route. Six mice of each group were sacrificed at 4, 8, 16, 24 weeks after immunization. At each time point, the clinical manifestations of mice were investigated, the serum, spleen and lung samples of mice were collected, body weight, spleen weight, bacteria loads in spleens, the anti-Brucella antibodies titers in serum and the cytokines concentrations of IFN-γ, IL-18 in serum or lung homogenate of the mice were detected. Twenty two weeks after immunization, all the mice were challenged with Brucella A19 through intratracheal aerosol delivery. Results: Compared with the control group, neither abnormal clinical symptoms nor significant changes in body weight were found in 104M immunization groups, at each time point when immunized through either nose dropping route, subcutaneous injection or aerosol routes; and the spleen weight of immunization groups were lower than control group after challenge (P<0.05): *M1 (0.26±0.16)g

LncRNA LINC00467 contributes to osteosarcoma growth and metastasis through regulating HMGA1 by directly targeting miR-217.

OBJECTIVE: Osteosarcoma (OS) is a common primary bone tumor. Despite multiple treatment strategies have made great progress, the overall clinical outcome of OS patients is frustrating. Long non-coding RNA (lncRNA) LINC00467 has been reported in several cancers, while the research of the role of LINC00467 in OS is limited. The aim of this study was to figure out the potential mechanism of LINC00467 in OS. PATIENTS AND METHODS: The expression levels of LINC00467, microRNA-217 (miR-217) and high mobility group A1 (HMGA1) were quantified by reverse transcription quantitative polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8), flow cytometry and transwell assay were performed to detect cell proliferation, apoptosis, migration and invasion, respectively. The protein levels of HMGA1, B-cell lymphoma-2 (Bcl-2), Bax, Cleaved Caspase-3 (C-Caspase 3), E-cadherin, N-cadherin and vimentin were measured by Western blot assay. Online software starbase was used to predict the binding sites of miR-217. Luciferase report assay and RNA Binding Protein Immunoprecipitation (RIP) assay were carried out for detecting the interaction between miR-217 and LINC00467 or HMGA1. RESULTS: The expression of LINC00467 and HMGA1 was increased in OS tissues and cells, while miR-217 expression was reduced. High expression of HMGA1 led to the poor overall survival. Down-regulation of LINC00467 or up-regulation of miR-217 could accelerate cell apoptosis, and slump cell proliferation, migration, invasion and EMT. However, miR-217 under-expression or HMGA1 over-expression could rescue these effects. Moreover, it was indicated that LINC00467 directly targeted miR-217 and HMGA1 was a target of miR-217. CONCLUSIONS: LINC00467 promoted cell proliferation, migration, invasion and EMT, and suppressed cell apoptosis by up-regulating HMGA1 via targeting miR-217.

MicroRNA-29c-3p inhibits osteosarcoma cell proliferation through targeting PIK3R3.

OBJECTIVE: MicroRNAs (miRNAs) are endogenous, non-coding small RNAs involving in pathological regulation. Previous studies have shown that microRNA-29c-3p is a tumor-suppressor gene. However, the role of microRNA-29c-3p in osteosarcoma (OS) has not been reported. This study aims to investigate the potential influence of microRNA-29c-3p on the progression of OS. PATIENTS AND METHODS: Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) was applied to examine microRNA-29c-3p levels in 40 matched pairs of OS tumor tissues and adjacent ones. The correlation between microRNA-29c-3p expression and clinical indicators in OS patient was analyzed. At the same time, qRT-PCR was used to detect microRNA-29c-3p level in OS cell lines. In addition, microRNA-29c-3p knockdown and the overexpression models were constructed in OS cell lines. The effects of microRNA-29c-3p on the biological functions of OS cells were analyzed via cell counting kit-8 (CCK-8) and transwell assays. Finally, the potential mechanism underlying microRNA-29c-3p in OS was explored by Western Blot and cell recovery experiment. RESULTS: QRT-PCR results revealed that microRNA-29c-3p level in OS tumor tissues was conspicuously lower than that in adjacent tissues. Compared with OS patients with the high expression of microRNA-29c-3p, those with low expression of microRNA-29c-3p had a higher incidence of distant metastasis and worse overall survival. Cell proliferative capacity and invasiveness in OS were enhanced after knockdown of microRNA-29c-3p; while the opposite results were observed after the overexpression of microRNA-29c-3p. QRT-PCR results revealed that microRNA-29c-3p negatively regulated PIK3R3 expression in OS cells. Moreover, microRNA-29c-3p and PIK3R3 levels were confirmed to be negatively correlated in OS tissues. In addition, cell reverse experiment demonstrated that PIK3R3 was responsible for the malignant progression of OS regulated by microRNA-29c-3p. CONCLUSIONS: MicroRNA-29c-3p expression was reduced in OS, and conspicuously associated with distant metastasis and poor prognosis. MicroRNA-29c-3p might inhibit the malignant progression of OS by modulating PIK3R3 expression.

The significant role of ATG5 in the maintenance of normal functions of Mc3T3-E1 osteoblast.

OBJECTIVE: To observe the effects of autophagy-related gene 5 (ATG5) on the proliferation, differentiation, and apoptosis of Mc3T3-E1 osteoblast as well as the effects of ATG5 on apoptosis of osteoblasts under the conditions of non-oxidative stress and oxidative stress. MATERIALS AND METHODS: ATG5 overexpressing and silencing cell lines were established in this experiment with lentiviral vector and transcription activator-like effect or nuclease (Talen) technique, respectively, using Mc3T3-E1 cells. Cell counting kit-8 (CCK-8) was used to detect the proliferation rate of osteoblasts, and flow cytometry was applied to detect the impacts of overexpressed and silenced ATG5 on the cell cycle. Alizarin red staining was used to detect the mineralization capacity of osteoblasts after 4-week osteoinduction differentiation. Quantitative Real-time polymerase chain reaction (qRT-PCR) and Western blot methods were adopted to detect the levels of gene and protein expressions of runt-related transcription factor 2 (Runx2), osteocalcin (OCN) and collagen I (COL-I) correlated with osteoblast differentiation after 48 h of osteoinduction differentiation. The staining with Annexin V-phycoerythrin/7-amino-actinomycin D (Annexin V-PE/7AAD) and flow cytometry were performed to detect the influence of ATG5 on osteoblast apoptosis. RESULTS: Stable ATG5 overexpressing and silencing Mc3T3-E1 cell lines were established successfully. CCK-8 test results showed that ATG5 silence inhibited cell proliferation, but the overexpression of ATG5 did not result in an obvious change in cell proliferation. Cell cycle did not change when ATG5 was overexpressed, while was stagnated in S-phase when silenced. The number of mineralized nodules of cells was reduced notably when ATG5 was silenced, while the overexpression of ATG5 did not have an impact on mineralization capacity of the cell after 4-week of osteoinduction differentiation. The test results of qRT-PCR and Western blotting suggested that ATG5 silence inhibited the gene and protein expressions of Runx2, OCN, and COL-I, while the influence of overexpressed ATG5 on the expressions of genes related to osteoblastic differentiation was not obvious after 48 h of osteoinduction differentiation. ATG5 silence made the cells easier to be damaged by hydrogen peroxide, which resulted in the rise of apoptosis rate of osteoblasts, while the overexpressed ATG5 inhibited osteoblast apoptosis after treatment with hydrogen peroxide for 12 h. CONCLUSIONS: ATG5 silence can lead to inhibition of osteoblast proliferation and differentiation. Moreover, it makes the cells easier to be damaged by oxidative stress, and it causes an increase in apoptosis. However, the overexpression of ATG5 strengthens the anti-oxidative capacity of osteoblasts and reduces apoptosis. ATG5 may be an effective target of anti-oxidative therapy for osteoporosis, which brings a new direction for the treatment of osteoporosis.

Dietary energy source and feeding levels during the rearing period affect ovarian follicular development and oocyte maturation in gilts.

Fifty-four Landrace x Yorkshire gilts (59.0 +/- 4.2 kg and 147 +/- 3 d old) were used to examine the effects of dietary energy source (starch or mixed fat) at high [112.5% of energy requirements recommended by NRC (1998)], normal (100%), and low (87.5%) energy feeding levels on ovarian follicular development and oocyte maturation. Forty-seven estrus gilts were slaughtered at Day 19 after the second estrus; oocytes were recovered from follicles >4 mm in diameter, and matured in vitro for 44 h. Gilts fed high-energy diets had more follicles >4 mm (mean, 25.8 vs. 19.1, P < 0.05) and more oocytes that reached metaphase II (80.3 vs. 64.0%, P < 0.05) than those fed the low-energy diet. Furthermore, gilts fed starch-rich diets had enhanced oocyte nuclear maturation relative to those fed fat-rich diets (75.4 vs. 68.0%, P < 0.05). Compared to the lower-energy feeding groups, high-energy feeding groups had higher (P < 0.05) blood concentrations of postprandial insulin (1562.4 vs. 990.0 ng/4 h), IGF-I (321.2 vs. 256.9 ng/mL), and LH pulses (2.7 vs. 1.4 pulses/6 h). Follicular fluid concentrations of IGF-I (198.5 vs. 143.1 ng/mL) and estradiol (152.6 vs. 124.8 ng/mL) were higher (P < 0.05) in the high-energy group than in the normal group. Compared with gilts fed the high-energy diet supplemented with fat, gilts fed the high-energy diet supplemented with starch had a tendency (P < 0.10) towards increased IGF-I concentration in both blood and follicular fluid, and improved oocyte nuclear maturation during culture in vitro. We inferred that starch-rich, high-energy diets during rearing may improve ovarian follicular development and oocyte maturation in replacement gilts.

Chemosensory basis of behavioural plasticity in response to deterrent plant chemicals in the larva of the Small Cabbage White butterfly Pieris rapae.

Behavioural and electrophysiological responsiveness to three chemically different secondary plant substances was studied in larvae of Pieris rapae L. (Lepidoptera: Pieridae). Three groups of caterpillars were studied that during their larval development were exposed to different rearing diets: an artificial diet or one of two host-plants, cabbage, Brassica oleracea, or nasturtium, Tropaeolum majus. In dual-choice leaf disc assays, caterpillars reared on cabbage were strongly deterred by the phenolic chlorogenic acid, the flavonol glycoside naringin and the alkaloid strychnine. However, behavioural plasticity was found in caterpillars reared on nasturtium or artificial diet in that these did not discriminate against chlorogenic acid. Caterpillars reared on the artificial diet were also significantly less sensitive to naringin and strychnine in the behavioural assay. Electrophysiological studies of the maxillary sensilla styloconica revealed that the deterrent neuron in the medial sensillum, but not in the lateral sensillum, of cabbage-reared caterpillars was more sensitive than the same neuron type of caterpillars reared on nasturtium or artificial diet. We conclude that (1) the diet-induced behavioural habituation to deterrents can at least partly be explained by chemosensory desensitisation of a generalist type of maxillary deterrent neuron; (2) behavioural cross-habituation to the three structurally diverse deterrent compounds can be traced back to cross-sensitivity for these compounds in the same gustatory neuron.

[Interaction between protein and ciprofloxacin].

AIM: To study the interaction between ciprofloxacin and BSA in physiological condition by fluorescence spectroscopy. METHODS: The affection of drug to the protein conformation was investigated. The binding constant between drug and BSA from a double reciprocal Lineweaver-Burk plot was determined and the main sort of binding force was found according to the thermodynamic parameters. RESULTS: The binding constants between BSA and ciprofloxacin at 26 degrees C and 45 degrees C are about 10(4). At 26 degrees C, the thermodynamic parameters of reaction between BSA and ciprofloxacin are delta H = -49.13 kJ.mol-1, delta G = -26.45 kJ.mol-1, delta S = -75 kJ.mol-1. The maximum wavelength of the synchronous fluorescence spectra of BSA moved from 279 nm to 289 nm with the increasing of the amount of ciprofloxacin. CONCLUSION: There exists fluorescence energy transfer between BSA and ciprofloxacin. The main sort of binding force between BSA and ciprofloxacin is Van der Waals' interaction. Ciprofloxacin can be deposited and be transported by serum protein in vivo. Ciprofloxacin affects the protein conformation.

Immunohistochemical study of the c-kit expressing cells and connexin 43 in the guinea-pig digestive tract.

The distribution of the c-kit receptor expressing cells and gap junction protein, connexin (Cx) 43 in the guinea-pig stomach (antrum), small intestine (jejunum) and colon (ascending) was studied by immunohistochemistry. The anti-c-kit protein immunopositive cells were regularly observed in the myenteric region throughout all three organs. The immunopositive cells were also sparsely distributed in the circular muscle layer of both the stomach and the colon, but not in the small intestine. They were densely located in the regions of the deep muscular plexus (DMP) of the small intestine and submuscular plexus (SMP) of the colon. In contrast, strong immunoreactivity to anti-Cx 43 antibody was observed in almost the entire thickness of the circular muscle layer of the stomach and the small intestine, but not in the colon. Dense immunoreaction deposits were observed in the region of the DMP and SMP. However, only very weak immunoreactivity to anti-Cx 43 antibody was detected in the myenteric region of all three organs. These results suggest that the c-kit receptor expressing cells or interstitial cells of Cajal (ICC) in the myenteric region of the three organs, and in the SMP of the colon, are poorly coupled with the bulk of circular muscle tissue by gap junctions, while ICC in the DMP and in the circular muscle layer of the stomach couple well with the surrounding muscle tissue.

Neutralizing mechanism of a monoclonal antibody against Japanese encephalitis virus glycoprotein E.

The neutralization of Japanese encephalitis virus (JEV) was studied using JEV-specific neutralizing (NT) monoclonal antibody (MAb) 503 that recognizes the envelope glycoprotein. Analysis using radiolabeled JEV and observations by confocal laser microscopy and electron microscopy indicated that the NT and protection activities of MAb 503 did not result from the prevention of the first step of JEV infection, binding of virus to the cell surface. Treatment with MAb 503 strongly inhibited JEV-induced cell fusion and internalization of JEV into the cells, and resulted in enhanced release of JEV-RNA from the cells. These observations suggested that the NT activity of MAb 503 is involved in the later steps of JEV infection.

Anti-c-kit protein immunoreactive cells corresponding to the interstitial cells of Cajal in the guinea-pig small intestine.

Interstitial cells of Cajal (ICC) of the guinea-pig small intestine were studied with whole-mount preparations by using the zinc iodide-osmic acid method (ZIO) and immunohistochemistry for vimentin and c-kit receptor tyrosine kinase, and by electron microscopy. The myenteric ICC visualized with ZIO staining are immunopositive to both anti-c-kit antibody (ACK-2) and anti-vimentin antibody (V9), and constitute an independent cellular network from the myenteric plexus. Those cells are characterized by many mitochondria, abundant intermediate filaments, and surface cell membranes not covered with a basal lamina. They are connected with each other by gap junctions at tips of the cytoplasmic processes. It is concluded that the myenteric ICC of the guinea-pig intestine are fibroblast-like cells and that they correspond to the c-kit expressing cells regarded as the intestinal pacemaker.

Identification of the interstitial cells of Cajal.

Observation of whole mount stretch preparations using the zinc-iodide-osmic acid method reveals a wide variety of interstitial cells in different tissue layers of the guinea-pig small intestine. And a subsequent electron-microscopic examination and survey of references makes clear that the interstitial cells of Cajal (ICC) depicted in original drawings of Cajal are heterogeneous and correspond to different types of interstitial cells. The myenteric ICC are characterized by long dichotomous branching processes which constitute cellular networks independent from the nerve plexus and form many gap junctions at their tips. Their ultrastructure is similar to that of fibroblasts and they have no basal lamina. The myenteric ICC show strong immunoreactivity for vimentin and the c-kit receptor, and probably correspond to the intestinal pacemaker cells. Within the circular muscle layer, ICC are represented by the cells that are closely associated with fine nerve bundles. The ICC have various shapes, ranging from bipolar to stellate, depending on the running pattern of the nerve fibers that they are associated with. They show fibroblast-like ultrastructure and have no basal lamina. They form gap junctions with smooth muscle cells and are immunoreactive for vimentin. On the other hand, ICC associated with the deep muscular plexus described in the guinea-pig by Cajal could not be clearly identified. However, it is suggested that the ICC in this location may correspond to glycogen-rich cells possessing a basal lamina. Although they show a fairly well-developed rough endoplasmic reticulum, Golgi apparatus and immunoreactivity for vimentin, ICC of the deep muscular plexus are probably specialized smooth muscle cells in nature.

Neuro-muscular junctions of longitudinal and circular muscle fibers of the guinea-pig esophagus and their relation to myenteric plexus.

The structure of the neuromuscular junctions (NMJs) and their relation to the myenteric plexus were studied by zinc iodide-osmic acid (ZIO) staining and by scanning electron microscopy in the guinea-pig esophagus. The esophageal muscle coat consisted of the inner circular and outer longitudinal striated muscle fibers. The myenteric plexus was located between the two muscle layers along its whole length and was characterized by a loose and irregular network. It was demonstrated that unmyelinated nerve fibers form NMJs with the muscle fibers of both layers. The NMJs in the longitudinal muscle can be classified as 'plate' type, whereas those of the circular muscle resemble the 'grape' type. The different NMJs in the two muscle layers probably correspond to different contractile properties. The whole-mount preparations with ZIO staining also demonstrated that some NMJs receive minute branches from the myenteric plexus. Therefore, it is likely that the myenteric plexus is involved in the control of striated muscles of the guinea-pig esophagus.

Ultrastructure of the zinc iodide-osmic acid stained cells in guinea pig small intestine.

This study has demonstrated that cells stained using the zinc iodide-osmic acid (ZIO) method have the same fine structural features as those of fibroblasts. They have a well developed Golgi apparatus, granular endoplasmic reticulum and many mitochondria. They have no basal lamina. They are distributed in association with the deep muscular plexus, within the outer circular muscle layer and in the space between the circular and longitudinal muscle layers. Since this staining method is believed to co-stain nerves and interstitial cells of Cajal, we concluded that these ZIO-positive, fibroblast-like cells represent at least some, if not all, of the interstitial cells which appeared in the original description by Cajal.

The cellular network of interstitial cells associated with the deep muscular plexus of the guinea pig small intestine.

Systematic examination using electron microscopic montages and serial sections has demonstrated that three types of interstitial cell, namely gap junction-rich cells, glycogen-rich cells and fibroblast-like cells, are densely located along the whole extent of the deep muscular plexus of the guinea pig small intestine. They tend to be distributed in an alternating fashion in the cellular network, connected with muscle cells of the outer, circular layer by means of gap junctions. These three types of interstitial cell show close relations to two types of nerve varicosity: one type is characterized by clear round vesicles with diameters of about 50 nm, and the other by flattened vesicles measuring about 35 nm by 70 nm. Electron-dense patches have been observed at the cytoplasmic side of the axonal membranes. Muscle cells of both inner and outer circular layers also show close relations to these two types of nerve varicosity. These morphological features are discussed with the implication that they may have some regulatory role in intestinal movement.

Interstitial cells associated with the deep muscular plexus of the guinea-pig small intestine, with special reference to the interstitial cells of Cajal.

Interstitial cells associated with the deep muscular plexus of the guinea-pig small intestine were studied by electron microscopy, and three-dimensional cell models were reconstructed from serial ultrathin sections with a computer graphic system. Three types of cells were recognized. The first type was similar in shape to smooth muscle cells, but did not contain an organized contractile apparatus. Many large gap junctions comprising about 4% of the cell surface were present; they connected cells of the first type to each other, to the second type of cell and to smooth muscle cells of the outer circular layer. The second type of cell had a well-demarcated cell body with long slender processes and was characterized by a large amount of glycogen comprising about 9% of the cell volume. The third type of cell was similar to fibroblasts, and contained well-developed Golgi apparatus and rough endoplasmic reticulum. Some of these fibroblast-like cells (a possible subtype) formed small gap junctions. All three types of cells showed close relationships with nerve varicosities. This cellular network consisting of gap-junction-rich cells, glycogen-rich cells and smooth muscle cells may be involved in the pacemaking activity of intestinal movement.

[Study on risk factors involving train traffic accidents--effects of human factors on accidents].

This article analysed human factors involving train traffic accidents by using log-linear model. The results showed that lower degree of culture (OR = 2.571) and weak nervous type (OR = 2.099) were risk factors involving train traffic accidents. Interactions were shown to exist between nervous type and degree of culture, average sleeping time everyday, and visuomotor reaction time.

[Epidemiological features and causes of railway traffic accidents].

This article reports on epidemiological features of railway traffic accidents and factors influencing traffic safety. An analysis of various kinds of railway traffic accidents over 30 years in Nanjing Railway Branch, Showed that railway traffic accidents have become a sort of modern social disease, and had particular epidemiological features. The peak of the epidemic curve appeared cyclically and had a close relation to social disturbances, Frequency of accident occurrence was the highest in the first season (period of spring transport) and the third season (period of high temperature) of the year thus most accidents happen in February and August. Most accidents occurred on Fridays and least on Mondays. Distribution of accidents had obvious "antenna" phenomenon in round graph which had a 24-hour cycle. Analysing the multiple factors influencing traffic safety, the results showed that the upper-limit-age of a train driver should not be more than 50 years old; The phenomenon "bathtub" between personage accident rate and age must be taken seriously. More attention should be paid to the psychological aspects when recruiting train drivers. In our country, it is urgent to set up standard of psychomovement function for choosing train locomotive drivers. Fatigue was one of the direct causes resulting in accident occurrences. No statistical correlation was found between biorhythm and accident occurrence.

Studies on social medicine and leprosy in east China.

Leprosy is a disease in which the social, economic, cultural and environmental factors play an important role in occurrence, spread, control, eradication and rehabilitation. Eliminating the unfavourable factors hindering leprosy control can make achieving the goal of basic eradication of leprosy in China before the end of this century possible. For this reason, since 1984 we have carried out systematic studies of the social aspects of leprosy in Baoying County, a former high-endemic area in Jiangsu Province of East China, where the endemicity of leprosy is nearing full control.