A New Segmented Virus Associated with Human Febrile Illness in China.

BACKGROUND: In 2017, surveillance for tickborne diseases in China led to the identification of a patient who presented to a hospital in Inner Mongolia with a febrile illness that had an unknown cause. The clinical manifestation of the illness was similar to that of tickborne encephalitis virus (TBEV) infection, but neither TBEV RNA nor antibodies against the virus were detected. METHODS: We obtained a blood specimen from the index patient and attempted to isolate and identify a causative pathogen, using genome sequence analysis and electron microscopy. We also initiated a heightened surveillance program in the same hospital to screen for other patients who presented with fever, headache, and a history of tick bites. We used reverse-transcriptase-polymerase-chain-reaction (RT-PCR) and cell-culture assays to detect the pathogen and immunofluorescence and neutralization assays to determine the levels of virus-specific antibodies in serum specimens from the patients. RESULTS: We found that the index patient was infected with a previously unknown segmented RNA virus, which we designated Alongshan virus (ALSV) and which belongs to the jingmenvirus group of the family Flaviviridae. ALSV infection was confirmed by RT-PCR assay in 86 patients from Inner Mongolia and Heilongjiang who presented with fever, headache, and a history of tick bites. Serologic assays showed that seroconversion had occurred in all 19 patients for whom specimens were available from the acute phase and the convalescent phase of the illness. CONCLUSIONS: A newly discovered segmented virus was found to be associated with a febrile illness in northeastern China. (Funded by the National Key Research and Development Program of China and the National Natural Science Foundation of China.).

Heterozygous/dispermic complete mole confers a significantly higher risk for post-molar gestational trophoblastic disease.

Hydatidiform moles are classified at the genetic level as androgenetic complete mole and diandric-monogynic partial mole. Conflicting data exist whether heterozygous complete moles are more aggressive clinically than homozygous complete moles. We investigated clinical outcome in a large cohort of hydatidiform moles in Chinese patients with an emphasis on genotypical correlation with post-molar gestational trophoblastic disease. Consecutive products of conceptions undergoing DNA genotyping and p57 immunohistochemistry to rule out molar gestations were included from a 5-year period at Beijing Obstetrics and Gynecology Hospital. Patient demographics and clinical follow-up information were obtained. Post-molar gestational trophoblastic disease or gestational trophoblastic neoplasia was determined by the 2002 WHO/FIGO criteria. A total of 1245 products of conceptions were classified based on genotyping results into 219 complete moles, 250 partial moles, and 776 non-molar gestations. Among 219 complete moles, 186 were homozygous/monospermic and 33 were heterozygous/dispermic. Among 250 partial moles, 246 were triploid dispermic, 2 were triploid monospermic, and 2 were tetraploid heterozygous partial moles. Among 776 non-molar gestations, 644 were diploid without chromosomal aneuploidies detectable by STR genotyping and 132 had various genetic abnormalities including 122 cases of various trisomies, 2 triploid digynic-monoandric non-molar gestations, 7 cases of possible chromosomal monosomy or uniparental disomy. Successful follow-up was achieved in 165 complete moles: post-molar gestational trophoblastic disease developed in 11.6% (16/138 cases) of homozygous complete moles and 37.0% (10/27 cases) of heterozygous complete moles. The difference between the two groups was highly significant (p = 0.0009, chi-square). None of the 218 partial moles and 367 non-molar gestations developed post-molar gestational trophoblastic disease. In conclusion, heterozygous/dispermic complete moles are clinically more aggressive with a significantly higher risk for development of post-molar gestational trophoblastic disease compared with homozygous/monospermic complete moles. Therefore, precise genotyping classification of complete moles is important for clinical prognosis and patient management.

Evidence of recombinant strains of porcine epidemic diarrhea virus, United States, 2013.

To investigate the evolutionary process by which porcine epidemic diarrhea virus (PEDV) in the United States hypothetically descended from strains in China, we analyzed PEDV-positive samples collected in China during January 2012-July 2013. Recombination in 2 strain sublineages was likely associated with identification of PEDV in the United States in 2013.

N-acetylcysteine alleviated silica-induced lung fibrosis in rats by down-regulation of ROS and mitochondrial apoptosis signaling.

Reactive oxygen species (ROS) is a normal metabolic product of cellular respiration, but too much ROS can induce cell apoptosis. Here, we used N-acetylcysteine (NAC) to inhibit ROS activity to explore the effects of NAC on silica-induced pulmonary fibrosis in rats and provide evidence for study on the mechanism of silicosis. 24 adult male Sprague-Dawley rats weighing 180-220 g were randomly divided into three groups with eight rats in each group. Silicosis model group and NAC group were adopted non-tracheal exposure method of disposable intrapulmonary injection of 50 g/L, silica suspension 1 mL to establish animal silicosis model, NAC group treated with 600 mg/kg NAC by gavage from the right day of modeling, all animals were sacrificed after 28 days. The level of ROS contents and mitochondrial transmembrane potential changes of AM, the mRNA expression level of type I and type III procollagen, cytochrome C, cysteinyl aspartate specific protease-9 and caspase-3 were detected. The severity of pathological changes and pulmonary fibrosis were observed by pathologic specimens. It was showed that ROS contents and MTP changes were lower in the NAC group compared with the silicosis model group, other indexes were lower in the NAC group than the model group, but higher than those of the control group, the degree of lung fibrotic lesions observed from the pathological slices showed the same trend. These data indicated that NAC can reduce ROS content of AM in silica exposure rats, the mitochondrial apoptosis pathway can also be inhibited, the severity of pulmonary fibrosis alleviated as a result.

SbPL1CE8 from Segatella bryantii combines with SbGH28GH105 in a multi-enzyme cascade for pectic biomass utilization.

Pectinases are useful biocatalysts for pectic biomass processing and are extensively used in the food/feed, textile and papermaking industries. Two pectinase genes, a pectate lyase (SbPL1CE8) and a polygalacturonase (SbGH28GH105) were isolated from Segatella bryantii and functionally characterized. Recombinant rSbPL1CE8 was most active against polygalacturonic acid (PGA) and pectin with a 60 % degree of esterification, with kcat/Km values of 721.18 ± 64.77 and 327.02 ± 22.44 mL/s/mg, respectively. Truncated rSbPL1 acted as a mesophilic alkaline pectate lyase, which was highly resistant to inactivation by methanol and ethanol. The rSbPL1CE8 exclusively digested PGA and pectin into unsaturated digalacturonate (uG2), which was further converted into galacturonic acid by rSbGH28GH105. The rSbPL1CE8 was highly effective for saccharification of waste materials from Zea mays, Oryza sativa and Arachis hypogaea processing, and for ramie fiber degumming. This novel pectate lyase has great potential for application in industrial pectic biomass processing.

[Autophagy in lung tissue of rats exposed to silica dust].

OBJECTIVE: To investigate the autophagy of effector cells in lung tissue at different time points when rats were exposed to free SiO2 dust. METHODS: Sixty Wistar rats (220∼230 g) were selected and allocated to experimental group (n = 30) and control group (n = 30). In the experimental group, a rat silicosis model was established by infusing SiO2 suspension into the trachea of rats. Six rats in each group were sacrificed on days 1, 7, 14, 21, or 28 of dust exposure. Lung tissue samples were collected to prepare lung tissue sections. The pulmonary inflammation and fibrosis were observed by HE staining. The proautophagosome, autophagosome, and autophagolysosome in lung tissue sections were observed under a transmission electron microscope. RESULTS: On day 1 of dust exposure, many proautophagosomes and autophagosomes were seen in both experimental group and control group. On day 7 of dust exposure, the experimental group had more autophagosomes in lung tissue than the control group. On day 14 of dust exposure, the experimental group had fewer autophagosomes than the control group. On days 21 and 28, autophagolysosomes were seen in macrophage plasma in both experimental group and control group; the autophagolysosomes in experimental group showed cloudy swelling and expansion, and some were vacuolated, and these changes were more significant on day 28. CONCLUSION: Free SiO2 dust can induce autophagy in the lung tissue of rats, with varying degrees at different time points of dust exposure.

[Effects of mast cells on degradation of collagen fibers in dimethylnitrosamine-induced hepatic fibrosis of rat].

OBJECTIVE: To investigate the relationship between mast cell and hepatic fibrosis by histopathological method and semi-quantitative measurement. METHODS: Seventy-two Wistary male rats, the control group and the normal group of each only 16, experimental group of 40 rat liver fibrosis was induced by injection of DMN and was sampled at eight different time points. HE, histochemistry, immunohistochemistry (ABC method) and immunofluorescence were performed. The size of fibrosis and the number of mast cells were counted. The expression of MMP-2 and TIMP-2 was documented and electron microscopic examination was performed. RESULTS: After injection of DMN, the fibrosis was the most severe in the 2 week (3.72%) and the first month (3.73%, P = 0.2626), and then gradually diminished, although residual fibrosis was still present at 12 months (1.42%, P = 0.0003). The appearance of mast cells began at 2 weeks (1.73 per 200 power field in average by light microscope) after the injection and reached the peak at 4 months (3.06, P = 0.008). Residual amount of mast cells were present at 12 months (1.04, P = 0.045). However, the degree of fibrosis was not proportional or overlapping with the number of mast cells in this experiment model. Mast cells expressed MMP-2 but not TIMP-2. CONCLUSIONS: In the DMN-induced rat liver fibrosis model, mast cell may be an integral player in the pathogenesis of liver fibrosis and may contribute to the degradation of fibrosis by synthesizing and secreting MMP-2.

Metastatic low-grade endometrial stromal sarcoma with variable morphologies in the ovaries and mesentery: A case report.

BACKGROUND: Low-grade endometrial stromal sarcoma (LGESS) classically exhibits a proliferative morphology. However, morphological variation of extrauterine tumors presents a diagnostic challenge. CASE SUMMARY: We report the case of a 76-year-old female patient with extensive extrauterine and abdominal neoplastic lesions. Computed tomography showed massive pleural and ascitic fluid, and there was an increase in serum cancer antigen 125. She underwent bilateral adnexectomy and tumor resection. The right ovary had been replaced by a multinodular mass that was 8.5 cm × 4.5 cm × 3.5 cm in size. In addition, there was a 24 cm × 15 cm × 13 cm mesenteric mass, which was also multinodular, with local invasion of the intestinal serosa and underlying muscle. Under the microscope, the tumors in different places exhibited two different patterns, thus presenting great challenges to diagnosis and treatment. Thorough pathological assessment eliminated all differential diagnoses in favor of metastatic LGESS derived from a 20-year-old primary tumor initially misdiagnosed as leiomyosarcoma. CONCLUSION: LGESS morphology varies according to tumor location. Accurate diagnosis is critical for appropriate treatment and improved prognosis and patient care.

The Inactivated gE/TK Gene-Deleted Vaccine Against Pseudorabies Virus Type II Confers Effective Protection in Mice and Pigs.

The highly virulent and antigenic variant of Pseudorabies virus (PRV) that emerged from classical Bartha-K61-vaccinated pig herds has caused substantial economic losses to the swine industry in China since 2011. A safe and more effective vaccine is most desirable. In this study, a gE/TK gene-deficient PRV, namely, HD/c, was constructed based on a PRV type II DX strain isolated from a commercial vaccine-immunized farm and the HD/c-based inactivated vaccine was formulated and evaluated for its safety, immunogenicity, and protective efficacy in mice and piglets. The resulting PRV HD/c strain has a similar growth curve to the parental DX strain. After vaccination, the inactivated HD/c vaccine did not cause any visible gross pathological or histopathological changes in the tissues of mice and piglets and provided rapid and potent protection against the challenge of the classical and variant PRVs at day 21 post-vaccination in mice. A single immunization of 108.5TCID50 inactivated PRV HD/c strain-elicited robust immunity with high titer of neutralizing antibody and provided complete protection from the lethal challenge of PRV DX strain in piglets. These results indicated that the inactivated PRV HD/c vaccine with the deletion of gE/TK genes was a safe and effective PRV vaccine candidate for the control of PRV.

[Macrophage apoptosis and the levels of interleukin-1 and interleukin-8 in the rats exposed to silica].

OBJECTIVE: To study the roles of macrophage apoptosis, IL-1, and IL-8 in the pathogenesis of rat pulmonary fibrosis induced by silica. METHODS: Forty eight male Wistar rats were divided into the 4 control groups (24 rats) and 4 experimental groups (24 rats). Rats in the control groups were treated with 1 ml normal saline by trachea instillation, whereas the rats in experimental groups were exposed 1 ml silica suspension (100 mg/ml) by trachea instillation for 1, 7, 14 and 28 days, respectively. Six rats of each group were sacrificed, then the bronchoalveolar lavage fluid and lung tissues were collected, respectively. Pulmonary inflammation, fibrosis and other pathological changes were detected with H.E. staining. Morphological changes of the early stage apoptosis in macrophages were detected with transmission electron microscope (TEM). The early apoptosis rates of macrophages in BALF were also assessed using Annexin V-FITC/PI kit. The IL-1 and IL-8 levels of serum were measured with the ELISA. RESULTS: The apoptotic rates (11.48% +/- 0.24%, 16.03% +/- 0.68%, 15.53% +/- 1.07%, 18.92% +/- 2.70%, respectively) of macrophage in the experimental groups increased obviously with time, as compared to the controls (5.47% +/- 2.06%, 6.39% +/- 0.215, 9.07% +/- 0.61% and 8.54% +/- 0.16%, Respectively) (P < 0.05). The IL-1 levels of serum in the experimental groups were 23.64 +/- 0.84, 23.38 +/- 1.10, 22.21 +/- 0.86 and 24.29 +/- 1.31 pg/ml, respectively, which were significantly higher than those (18.52 +/- 1.23, 18.40 +/- 1.6, 17.92 +/- 2.21 and 18.53 +/- 2.64 pg/ml, respectively) in the control groups (P < 0.05) without time-effect relationship. The serum IL-8 levels on the 1st, 7th and 14th days in the experimental groups were 21.32 +/- 1.44, 21.90 +/- 2.08 and 22.00 +/- 2.80 pg/ml, respectively, which were significantly higher than those (17.69 +/- 1.09, 16.98 +/- 2.09 and 17.54 +/- 1.62 pg/ml, respectively) in the control groups (P < 0.05). CONCLUSION: The early macrophage apoptosis and changes of IL-1 and IL-8 may in lungs may play an important role in the development of pulmonary fibrosis induced by silica.

Fine mapping of antigenic epitopes on capsid proteins of porcine circovirus, and antigenic phenotype of porcine circovirus type 2.

Type 2 porcine circovirus (PCV2) is associated with post-weaning multisystemic wasting syndrome in pigs. In this study, three monoclonal antibodies (mAbs) against the capsid protein (Cap) of PCV2, eight mAbs to Cap of type 1 porcine circovirus (PCV1) and five mAbs specific for Cap of both PCV1 and PCV2, were generated and used to finely map the antigenic sites of PCV1 and PCV2, and to identify the antigenic phenotype of PCV2 with different length of genome. Five linear B-cell epitopes, including the residues 231-233 and 195-202 specific for PCV2, residues 92-103 specific for PCV1, and residues 156-162 and 175-192 shared between PCV1 and PCV2, were finely defined with synthetic peptides, and the critical residue in epitope 231-233 and 156-162 was located at residues 233 ((233)Proline) and 156 ((156)Tyrosine), respectively. The conformational epitopes recognized by mAbs with neutralizing activity against both PCV1 and PCV2 were detected in transfected PK-15 and the residues 231-233 also participated in the formation of conformational epitopes. Analysis of antigenic diversity on these epitopes exhibited three antigenic phenotypes of PCV2, (1766)PCV2, (1767)PCV2 and (1768)PCV2 using mAbs. The results from this study first demonstrated the different antigenic phenotype between PCV2 isolates.

[Clinicopathologic study of sinonasal inflammatory myofibroblastic tumor].

OBJECTIVE: To study the clinicopathologic features, immunophenotype and ultrastructural features of sinonasal inflammatory myofibroblastic tumors (IMT). METHODS: The clinical and histologic features of 5 cases of sinonasal IMT were reviewed. Immunohistochemical study for vimentin, MSA, SMA, calponin, h-caldesmon, desmin, ALK, fibronectin, CK, S-100 and Ki-67 was carried out. Ultrastructural examination was also performed in two of the cases. RESULTS: The patients age ranged from 28 to 62 years (mean = 43 years). The male-to-female ratio was 2:3. The clinical presentation included nasal obstruction, nasal discharge, nasal bleeding, facial pain, facial swelling, toothache and tear overflow. All of the 5 patients suffered from disease relapses; and 4 of them had recurrences for more than 5 times. One patient had lymph node metastasis and 3 patients died of the disease. Histologically, the tumor cells were arranged in interlacing fascicles and sometimes haphazard in fashion. They were spindly in shape, cytoplasm eosinophilic with mild nuclear atypia and a low mitotic activity. The intervening stroma was myxoid in appearance accompanied by lymphocyte and plasma cell infiltration, abundant blood vessels and focal collagenized areas. In 3 of the recurrent cases, the tumor cells displayed increased nuclear atypia and mitotic activity (average about 5 to 6 per 10 high-power fields), accompanied by patchy necrosis, less inflammatory cell infiltration and focal sarcomatous changes. Immunohistochemical study showed that the tumor cells were diffusely positive for vimentin. SMA, MSA, calponin and fibronectin were variably expressed. Desmin was weakly positive in 1 case. The staining for h-caldesmon, ALK, S-100 and CK was negative. The Ki-67 proliferation index increased with tumor recurrences. Electron microscopy revealed abundant rough endoplasmic reticulum and dense body formation in the cytoplasm. There were an increased amount of collagen fibers in the stroma. CONCLUSIONS: IMT rarely occurs in nasal cavity and paranasal sinuses. The tumor is prone to local invasion and recurrences, with subsequent progression to frank malignancy and distant metastasis, resulting in high mortality and poor prognosis. Complete surgical resection remains the main modality of treatment.

Increased proline loading to phloem and its effects on nitrogen uptake and assimilation in water-stressed white clover (Trifolium repens).

The aim of this study was to investigate the physiological significance of increased proline loading to phloem caused by water-deficit stress in relation to nitrogen (N) uptake and assimilation. N uptake and N assimilation were quantified by 15N tracing in well-watered (control) and water deficit-stressed white clover (Trifolium repens). De novo proline synthesis and proline loading to the phloem were also compared between treatments. The relationships among proline concentrations in phloem exudates, N uptake, and assimilation of newly absorbed N were assessed. The newly synthesized proline in the phloem exudates increased rapidly after 3 d of water deficit. The water-deficit treatment significantly reduced the maximum nitrate reductase activity (NRA), and also attenuated de novo synthesis of amino acids and proteins in the roots. The increase in proline concentrations in phloem exudates was closely related to reductions in NRA in the roots, N uptake, and the assimilation of newly absorbed N. The accumulation of proline induced in roots by exogenous proline and NH4Cl treatments was closely associated with the decrease in NRA. These results indicate that increased proline transport to roots via phloem caused by water deficit has a significant influence on the down-regulation of N uptake and the assimilation of newly absorbed N.

[Pathologic diagnosis of specific infections in upper aerodigestive tract].

OBJECTIVE: To find a fast and simple method for detection of specific pathogens in upper aerodigestive tract. METHODS: Sixty-one cases of specific infections in upper aerodigestive tract encountered during a 10-year period in Beijing Tongren Hospital were retrospectively studied. Six histochemical stains, including PAS, Giemsa, Gram, methylene blue, modified Warthin-Starry and acid-fast stains were applied. The morphology of different pathogens was studied and the staining patterns were compared. RESULTS: There were 23 cases of pharyngeal treponemal infection, 10 cases of short treponemal infection, 4 cases of mycobacterial infection, 4 cases of infection by rhinoscleroma bacilli, 1 case of sinonasal fungal infection, 1 case of combined infection of bacteria and Oidium albicans, 2 cases of tonsillar Actinomycetes and 16 cases of non-specific bacterial infections. Both pharyngeal treponemal infection and infection by rhinoscleroma bacilli could be detected by modified Warthin-Starry stain. As for sinonasal fungal infection, PAS, Giemsa and modified Warthin-Starry stains were useful in differentiating different types of fungi. Mycobacteria were best demonstrated by conventional acid-fast stain. CONCLUSIONS: Special histochemical stains performed on histologic sections are useful for diagnosing specific infections in upper aerodigestive tract.

[Clinicopathologic evaluation of 36 cases of allergic fungal sinusitis].

OBJECTIVE: To characterize clinicopathological features of allergic fungal sinusitis (AFS). METHODS: Thirty-six cases of AFS were retrieved from the department archival files of Beijing Tongren Hospital from 2002 to 2006. AB-PAS, GMS and MUC5B stain were performed using paraffin-embedded tissues of the cases. Ten cases with available fresh diagnostic tissue were investigated by electron microscopy. RESULTS: Patients included 21 males and 15 females. The age of patients ranged from 11 to 53 years. Atopy was very common in these patients. On plain CT scans, the affected nasal sinuses were filled with soft tissue shadow with patchy hyperdensity. The bony sinus wall showed areas of pressure erosion. Skin antigen tests showed fungal positivity in 31 of 36 cases. Serum levels of the total IgE and/or the specific fungal IgE were elevated in 20 cases. The eosinophil quantity was elevated in 23 cases. Fungal culture was positive in 10 cases. Gross examination showed thick putty secretions within the lesions. Light microscopy showed typical "eosinophilic mucin". Fungal elements were seen with AB-PAS, GMS and MUC5B stains. Electron microscopy demonstrated degranulation by the eosinophils. CONCLUSIONS: "Eosinophilic mucin" is the typical histopathological feature of AFS. AB-PAS, GMS and MUC5B staining methods can used to detect fungal species in mucin. Accurate diagnosis of AFS requires correlations among clinical findings, radiologic examinations, laboratory tests and histopathologic features. However, the ultimate diagnosis requires a histopathologic confirmation.

A Robust Gene Expression Prognostic Signature for Overall Survival in High-Grade Serous Ovarian Cancer.

The objective of this research was to develop a robust gene expression-based prognostic signature and scoring system for predicting overall survival (OS) of patients with high-grade serous ovarian cancer (HGSOC). Transcriptomic data of HGSOC patients were obtained from six independent studies in the NCBI GEO database. Genes significantly deregulated and associated with OS in HGSOCs were selected using GEO2R and Kaplan-Meier analysis with log-rank testing, respectively. Enrichment analysis for biological processes and pathways was performed using Gene Ontology analysis. A resampling/cross-validation method with Cox regression analysis was used to identify a novel gene expression-based signature associated with OS, and a prognostic scoring system was developed and further validated in nine independent HGSOC datasets. We first identified 488 significantly deregulated genes in HGSOC patients, of which 232 were found to be significantly associated with their OS. These genes were significantly enriched for cell cycle division, epithelial cell differentiation, p53 signaling pathway, vasculature development, and other processes. A novel 11-gene prognostic signature was identified and a prognostic scoring system was developed, which robustly predicted OS in HGSOC patients in 100 sampling test sets. The scoring system was further validated successfully in nine additional HGSOC public datasets. In conclusion, our integrative bioinformatics study combining transcriptomic and clinical data established an 11-gene prognostic signature for robust and reproducible prediction of OS in HGSOC patients. This signature could be of clinical value for guiding therapeutic selection and individualized treatment.

Water-deficit accumulates sugars by starch degradation--not by de novo synthesis--in white clover leaves (Trifolium repens).

Labeling 13CO2 in steady-state condition was used to estimate quantitative mobilization of recently fixed carbon or stored sugar during water-deficit in white clover (Trifolium repens L.). Water-deficient gradually decreased leaf-water parameters and total amount of recently fixed carbon. Amount of 13C incorporated into glucose, sucrose and soluble sugars fraction rapidly decreased after 3 days of water-deficit treatment. In contrast, the previously stored soluble sugars significantly increased after 5 days of water-deficit with a coincidence of significant decrease in starch concentration. A highly significant (P < or = 0.001) relationship between the decrease in leaf-water potential caused by water-deficit and the increase in ratio of soluble sugar/starch concentration was observed in water deficit-stressed plants. The data indicate that soluble carbohydrate accumulated by water-deficit treatment is mainly because of the hydrolysis of previously stored starch rather than to de novo synthesis.

[Investigation on job stress of pediatricians and nurses working in pediatric department].

OBJECTIVE: To investigate the occupational stressors and modifiers of pediatricians and nurses in order to find the measurements for control of the job stress. METHODS: 427 pediatricians and nurses working in five hospitals of a city served as subjects. Of them, the staff in section of pharmacy and toll offices in each hospital mentioned above served as control group. The General Job Stress Questionnaire was used to investigate the job stress by self-assessment. RESULTS: The scores of job demand, job risk, drug using, daily job stress, positive feelings, patient A behavior, physical environment and feeling balance in pediatricians and nurses were higher than those of control group, but the scores of job-person conflict, environmental control, technology utility, mental health, responsibility on things were lower than those of control group (P<0.05). The points of job future, job locus of control, self-esteem, job satisfaction, job load variance, depression in nurses were higher than those of pediatricians, and non-work activities, job risk and daily life stress were lower than those of doctors (P<0.05). The main affecting factors on job strain of pediatric staff included job monotony, higher job demand, more non-work job, lower job control, more job risk, job future ambiguous, poorer social support, lower job locus control and lower self-esteem. CONCLUSION: The stress degree of pediatric staff is higher than that of controls. The pediatricians have more job stress than that of nurses. The main stressors of pediatric staff are job monotony, higher job demand, more non-worker activity, lower job control, higher job risk and ambiguous job future. The main modifiers are good social support, external job locus of control and higher self-esteem.

A new steroidal saponin, yuccalan, from the leaves of Yucca smalliana.

An extract of the leaves of Yucca smalliana Fern. (Agavaceae) showed potential antimicrobial activity. Employing a bioassay linked fractionation method, one of the active principles, namely yuccalan, was isolated as a new steroidal saponin. The structure of the new steroidal saponin was elucidated as 3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(3beta, 5alpha, 6alpha, 25S)-spirostan-3,6,27-triol (1) using various spectroscopic techniques, including IR, MS, 1D and 2D 1H-NMR, and 13C-NMR. The purified yuccalan showed antifungal activities against both Rhizoctonia solani and Fusarium oxysporum.

[Morphologic observation and pathogenesis investigation of regenerated sinusoidal endothelial cells in remodelling rat hepatic necrotic tissue].

OBJECTIVE: To investigate the morphological changes and regeneration mechanism of sinusoidal endothelial cell. METHODS: Sixty male Wistar rats (bought from SLC company limited of Japan) were divided into three groups. Fifty of them belonged to experiment group, five rats belonged to untreated group, and the rest five ones belonged to normal saline treated group. The experiment group was then divided into ten subgroups. All the rats of the experiment group were killed under anaesthesia using aether at 12, 24, 36 hrs, and 2, 3, 5, 7, 8, 10 and 14 days subsequently after an one-off injection of dimethylnitrosamine (DMN) (50 mg/kg). The liver tissues, bone marrows and peripheral blood of the rats were taken out rapidly. All the tissues received with HE staining, immunohistochemistry staining and double immunofluorescence labelings, and they were observed under a light microscope and electron microscope. The livers, bone marrows and peripheral blood from the rats at 24 hrs to 14 days after an injection of DMN were examined by light microscopic, immunohistochemical, and ultrastructural methods. RESULTS: Small focal necrosis of the liver tissues was found at 12 hrs after the DMN injection, and gradually becomes more obvious from the 24 hrs. The most obvious necrosis, with lots of ED-1 (monocyte/phagocyte marker of rats) positive cells infiltration, was observed at 36 hrs. On the 2nd day and 3rd day after injection, the necrotic fragments and red cells were phagocyted by ED-1 positive macrophages. On the 5th day, some of the ED-1-positive cells were transformed from round to spindle in shape. On the 7th day, these cells contacted with residual reticulin fibers and became positive for SE-1, a marker of hepatic sinusoidal endothelial cells and Tie-1, an endothelial cell-specific surface receptor, associated with frequent occurrence of ED-1/SE-1 and ED-1/Tie-1 double positive spindle cells. On the 8th day, the histomorphology of liver tissue was similar with that on day 7, except that the range of the lesions had become smaller. On the 10th day, the regeneration of liver tissue increased, filling in the necrosis. On the 14th day, the necrotic tissues were almost replaced by regenerated liver tissues and thin bundles of central-to-central bridging fibrosis. 12 hrs after the DMN injection, bone marrow studies showed an increase in the number of ED-1 positive mononuclear cells, some of which were both BrdU/ED-1 positive. The number of ED-1 positive mononuclear cells reach their highest level at 36 hrs. These cells are morphologically similar to round mononuclear cells in bone marrows and could be found in the peripheral blood from 24 hrs to the 10 days. They reached their highest level in peripheral blood at the same time as in the bone marrow. These cells morphologically resembled ED-1 positive cells in necrotic tissues of the liver. CONCLUSIONS: These findings suggest that round mononuclear ED-1-positive cells proliferate first in the bone marrow after DMN treatment, reach necrotic areas of livers through circulation, and differentiate to sinusoidal endothelial cells. Namely, hepatic sinusoids in DMN-induced necrotic areas may partly be reorganized possibly by vasculogenesis.