Sildenafil might impair maternal-fetal immunotolerance by suppressing myeloid-derived suppressor cells in mice

Myeloid-derived suppressor cells (MDSCs) as an important population of immune cells were found to restrain T cell function, polarize T-helper cells (Th) 1/Th2 toward Th2 response and induce regulatory T cells (Tregs), therefore enhancing the immunotolerance during pregnancy. Sildenafil has been applied for poor endometrial quality in implantation failure patients. Nevertheless, investigations have shown that sildenafil could reduce MDSCs-dependent immunosuppression. Whether sildenafil affects embryo implantation by suppressing MDSCs? To address this question, using the mice model, we investigated the amounts of immune cells in peripheral blood and endometrial cells from control group (CG), sildenafil low-dose group (LDG) and high-dose group (HDG). We found that both treatment groups displayed a marked deficiency in polymorphonuclear (PMN)-MDSCs and Th2 from mice blood and endometrium as compared to these from CG. The frequency of Tregs in endometrium from HDG was lower than those from CG. Th1/Th2 ratio in both periphery and uterus from study groups showed a significant increase as compared to those from CG. By relevance analysis, we found that the level of Tregs positively correlated with the level of PMN-MDSCs, whereas the Th1/Th2 ratio negatively correlated with the frequency of PMN-MDSCs in uterus. Moreover, there was a positive relationship between the amount of blood PMN-MDSCs and endometrial PMN-MDSCs. These results suggest that we should carefully weigh the pros and cons of using sildenafil when applied to patients with poor endometrial receptivity.

A network pharmacology-based study on Alzheimer disease prevention and treatment of Qiong Yu Gao

Background and objective

As the pathological mechanisms of AD are complex, increasing evidence have demonstrated Chinese Medicine with multi-ingredients and multi-targets may be more suitable for the treatment of diseases with complex pathogenesis. Therefore, the study was to preliminarily decipher the bioactive compounds and potential mechanisms of Qiong Yu Gao (QYG) for AD prevention and treatment by an integrated network pharmacology approach.

Methods

Putative ingredients of QYG and significant genes of AD were retrieved from public database after screening. Then QYG ingredients target proteins/genes were obtained by target fishing. Compound-target-disease network was constructed using Cytoscape to decipher the mechanism of QYG for AD. KEGG pathway and GO enrichment analysis were performed to investigate the molecular mechanisms and pathways related to QYG for AD treatments.

Results

Finally, 70 compounds and 511 relative drug targets were collected. In which, 17 representative direct targets were found. Gene ontology enrichment analysis revealed that the adenylate cyclase-inhibiting G-protein coupled acetylcholine receptor signaling pathway was the key biological processes and were regulated simultaneously by the 17 direct targets. The KEGG pathway enrichment analysis found that three signaling pathways were closely related to AD prevention and treatment by QYG, including PI3K-Akt signaling pathway, regulation of actin cytoskeleton pathway and insulin resistance pathway.

Conclusion

This study demonstrated that QYG exerted the effect of preventing and treating AD by regulating multi-targets with multi-components. Furthermore, the study demonstrated that a network pharmacology-based approach was useful for elucidation of the interrelationship between complex diseases and interventions of Chinese herbal medicines.

[Eosinophilic granulomatosis with polyangiitis: 30 cases report]

Objective: To improve the understanding of Eosinophilic granulomatosis with polyangiitis (EGPA). Methods: A total of 30 EGPA patients from the China-Japan Friendship Hospital between August 2005 and April 2017 were included, and a systematic retrospective study about clinical manifestations, laboratory findings, imaging features, pathology and so on was conducted. Results: There were 9 males and 21 females. Mean age was (44.5±13.9) years at diagnosis. Among these patients, 26 (86.7%) had asthma, duration was 45.0 (20.0, 78.7) months, and 15 (50.0%) had asthma as their first symptom. Rhinitis/nasosinusitis occurred in 27 (90.0%), skin lesions in 13 (43.3%), neuropathy in 10 (33.3%), heart disease in 8 (26.7%), renal involvement in 3 (10.0%) and gastro-intestinal manifestations in 3 (10.0%) of the patients. Peripheral blood eosinophil>10% accounted for 23/30 (76.7%). There were 3 patients (10.0%) who had positive anti-neutrophil antibody, and the pattern by immunofluorescence was mainly perinuclear. Migratory infiltrates often observed on the chest radiograph, and the main presentation was ground-glass opacity, amounting for 21/30 (70.0%). The pathological manifestations were extravascular eosinophilic tissue infiltration, necrotizing vasculitis, and extravascular granulomas, and the latter two of which were fewer. Conclusion: The manifestations of EGPA are individual, complex, with a lack of pathognomonic symptoms, and female predominated.

Medicolegal Identification of Medical Malpractices in Orthopaedic Surgery

OBJECTIVES

To analyze the characteristics of medical malpractices in orthopaedic surgeries, to explore principles and methods in medical legal identification, and to provide basic data for uniform medicolegal standard for the future medical identification.

METHODS

A retrospective analysis was conducted on 100 cases of medical malpractices in orthopaedic surgery, among the 364 cases archived in Medicolegal Expertise Center of Xi'an Jiaotong University during 2002-2015.

RESULTS

In the 100 cases of orthopedic medical malpractices, with 104 hospitals involved in, 95 cases were judged with medical errors and the other 9 cases with no error. The top 3 reasons for errors were （1） inadequate observation or estimation of diseases （27.9%）, （2） intraoperative improper operation （17.3%）, and （3） delayed or missed diagnosis and treatment （12.5%）. The consequences of medical malpractices were mostly disability （61%）, followed by prolonged diseases （31%） and death （8%）. With regard to the causal relationship between medical errors and consequences, 95 cases （91.4%） were with causality and the other 9 cases （8.6%） with no causality. Specifically, 56 cases （53.9%） were with medical errors as the secondary causes accounting for 25% causative potency, and 20 cases （19.2%） were with medical errors as the major causes accounting for 75% causative potency.

CONCLUSIONS

It is pivotally important for determining the causative potency of medical errors to analyse the causes of damages in orthopaedic surgery and to distinguish subjective factors from objective ones of medical errors.

Abstract P2-06-12: Oncogenic potential of Trefoil factor 3 in initiation of mammary carcinoma through suppression of p53 pathway

Background

Oncogenic transformation is a complex multistep process where normal cells acquire the hallmarks of cancer, leading to unrestrained outgrowth of malignant clones. Trefoil Factor 3 (TFF3) is a clinically validated and functionally potent oncogene in mammary carcinoma. Elevated TFF3 expression has been consistently observed in mammary carcinoma, being involved in cancer progression. The present study investigates the potential functional role and the underlying mechanisms of TFF3 in promoting oncogenic transformation early in the onset of mammary carcinoma.

Material and method

Immortalized human mammary epithelial cells (HMECs): HMEC-hTERT, MCF10A and MCF12A, with forced expression of TFF3, were used as in vitro models and in an orthotopic xenograft model to study the oncogenic roles of TFF3. Furthermore, microarray analysis, immunofluorescence, and ubiquitination and CHX chase assays were used to examine the involvement of p53 pathway in TFF3 mediated-oncogenic transformation.

Results

Immortalized HMECs with forced expression of TFF3 exhibited the capacity of anchorage independent growth in the soft agar colony formation assay, which is a hallmark of oncogenic transformation. The forced expression of TFF3 also enhanced 3D growth of the immortalized HMECs in matrigel. Furthermore, immortalized HMECs with forced expression of TFF3 gaverise to orthotopic xenograft tumors in nude mice, which are not observed in mice injected with immortalized HMECs. These observations suggest that TFF3 stimulates the oncogenic transformation of non-malignant immortalized HMECs. In addition, the forced expression of TFF3 promoted aberrant cell proliferation, resistance to apoptosis, and increased cell migration and invasion of the HMECs, all these being important hallmarks of cancer. Here, we showed that TFF3-mediated oncogenic transformation of the immortalized HMEC-hTERT cells is dependent on p53 signaling pathway suppression. Mechanistically, TFF3 downregulated NF-κB (p65)-mediated transcription of p53 through decreasing NF-κB (p65) expression and nuclear accumulation. TFF3 also decreased p53 protein levels through post-transcriptional regulation. The forced expression of TFF3 increased MDM2 expression, resulting in an increased ubiquitin-mediated proteasomal degradation of p53. Moreover, forced expression of TFF3 decreased the cleaved form of MDM2, which is responsible for stabilizing p53 protein. Concordantly, HMECs with forced expression of TFF3 exhibited shorter p53 protein half-life as compared to vector control HMECs .

Conclusion

In summary, our study highlights the oncogenic potential of TFF3 in the initiation of mammary carcinoma through the suppression of the p53 pathway.

Citation Format: Chen RM, Pandey V, Chong QY, Poh HM, Zhang MY, Kumar AP, Lobie PE. Oncogenic potential of Trefoil factor 3 in initiation of mammary carcinoma through suppression of p53 pathway [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-12.

[Pleural amoebic empyema: a case report]

In this paper, a case of pleural amoebic empyema and its diagnosis and treatment were reported.

Submucosal tunneling endoscopic resection for treatment of esophageal leiomyomas arising from the muscularis propria

AIM

To investigate the safety and indications of submucosal tunneling endoscopic resection (STER) by comparing the results of STER with other operations for the treatment of esophageal leiomyomas originating from the muscularis propria layer.

METHODS

We enrolled 121 patients with esophageal leiomyomas originating from the muscularis propria layer who underwent resection from November 1, 2011 to March 1, 2018 in this retrospective study. The clinical features and treatment results were collected and analyzed.

RESULTS

There was a significant difference between the thoracoscopic enucleation (TE) group and the endoscopic resection (ER) group in tumor location and size, operation time, en bolc resection rate, average hospital stay and cost (P < 0.05). There was also a significant difference in the en bolc resection rate, operative time, average hospital stay and cost between the STER group and the ER group (P < 0.05). Although tumor diameter of the STER group (2-40 mm; mean, 17.68 mm) was smaller than that of the TE group (5-80 mm; mean, 20.33 mm), the difference was not significant (P = 0.229). Tumor size, en bolc resection rate, average hospital stay and cost also differed significantly between the STER group and the endoscopic submucosal dissection (ESD) group (P < 0.05). The en bolc resection rate of the STER group was lower than those of other groups, but no tumor recurrence or metastasis was detected during the follow-up period (mean: 22.4 mo; range: 3-60 mo) in the three groups.

CONCLUSION

STER is safe and effective for the treatment of esophageal leiomyomas originating from the muscularis propria layer. We recommend STER for the tumors smaller than 4 cm.

Differentially expressed circular RNAs in systemic lupus erythematosus and their clinical significance

It has been reported that circRNAs are diff ;erentially expressed in many diseases and can be used as new biomarker to facilitate disease diagnosis. Circular RNAs (circRNAs) microarray were used to identify dysregulated circRNAs in plasma of systemic lupus erythematosus (SLE) patients. Then, we confirmed the microarray data by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in both plasma and peripheral blood mononuclear cells (PBMCs) of SLE. One hundred and twelve circRNAs were identified to dysregulated expressed in plasma of SLE as compared to healthy controls. The results of qRT-PCR showed that the levels of hsa_circRNA_407176 and hsa_circRNA_001308 were decreased in both plasma and PBMCs of SLE when compared with healthy controls. The receiver operating characteristic (ROC) curve area of hsa_circRNA_407176 and hsa_circRNA_001308 in plasma were 0.599 and 0.662, respectively. The area under the ROC curves of hsa_circRNA_407176, hsa_circRNA_406567 and hsa_circRNA_001308 in PBMCs were 0.806, 0.744, and 0.722, respectively. Our study illustrated that hsa_circRNA_407176 and hsa_circRNA_001308 in plasma and PBMCs could be potential biomarkers for SLE.

Long non-coding RNA HOST2 enhances proliferation and metastasis in gastric cancer

This study investigates the influence of long noncoding RNA HOST2 on the biological functions of gastric cancer cells; including proliferation, migration and invasion. Differentially expressed lncRNAs in gastric cancer (GC) were screened by microarray analysis, and HOST2 expression in GC tissues and cell lines was determined by quantitative real-time PCR (qRT-PCR). GC cell proliferation, migration and invasion were detected by CCK-8, wound healing and transwell assays. Western blot investigated expression of epithelial-mesenchymal transition (EMT) related proteins, and association was established between over-expressed HOST2 and the number of patients with lymph node and distant metastasis. HOST2 expression was also positively related to GC cell invasion ability, and although its expression in the p-shHOST2 group was remarkably decreased, it was significantly higher than in the Mock and NC groups. Compared to the Mock and NC groups, the p-shHOST2 group presented significant decreases in proliferation and wound healing rates, and the reverse result was noted in the p-HOST2 group. In addition, the number of p-shHOST2 group invasive cells was remarkably less than in the Mock and NC group, and the opposite result was achieved in the p-HOST2 group. Moreover, p-HOST2 had more significant EMT, but this was suppressed in the p-shHOST2 group. Finally, HOST2 silencing suppressed GC cell proliferation, migration and invasion; and it could therefore be considered as a novel biomarker and therapeutic target in gastric cancer.

Down-regulation of telomerase reverse transcriptase-related anti-apoptotic function in a rat model of acrylamide induced neurobehavioral deficits

Although the precise mechanism is unknown, neuron apoptosis is believed to participate in neuropathy caused by acrylamide (ACR). Telomerase reverse transcriptase (TERT) exhibits an anti-apoptotic function, but its contribution to the pathogenesis of ACR neurotoxicity is unclear. We investigated adult male rats that were given 30, 40 and 50 mg/kg ACR three times/week for 4 weeks. We found that ACR treatment caused significant deficits in sensory/motor function as measured by gait score, landing foot spread distance, movement initiation test and tail immersion test. Histological examination showed that the cerebral cortex in all ACR treated animals exhibited fewer neurons and more condensed nuclei than normal cortex. A significant increase in apoptosis was found in the cerebral cortex of rat brains subjected to ACR treatment in a dose-dependent manner. The expression of TERT in the brain was significantly reduced by ACR treatment. The pro-apoptotic cleaved caspase-3 protein level was increased, while the anti-apoptotic Bcl-2 protein level was decreased by 30 - 50 mg/kg ACR. Our findings indicate that TERT and its downstream regulators of neuron apoptosis, including Bcl-2 and cleaved caspase-3, were involved in ACR neurotoxicity.

[Analysis of 833 times measured hepatic venous pressure gradient]

Objective: To summarize and analyze the clinical data of hepatic venous pressure gradient (HVPG) and to explore the application value of HVPG in the diagnosis, evaluation and clinical treatment of portal hypertension in cirrhosis. Methods: The patient data of HVPG measurement performed in Shandong Provincial Hospital from April 2010 to November 2017 were collected. Results: A total of 633 patients with 833 times of HVPG measurements were included. There was significant difference in HVPG between patients with different etiologies, different Child-pugh grades and different degrees of decompensated cirrhosis. Conclusion: The HVPG test is suitable for the diagnosis and evaluation of portal hypertension. The HVPG of patients with different severity of liver cirrhosis can guide the choice of the treatment plan, and the HVPG measurement should also be strictly standardized and quality control.

Beneficial Phytochemicals with Anti-Tumor Potential Revealed through Metabolic Profiling of New Red Pigmented Lettuces (Lactuca sativa L.)

The present study aimed to compare polyphenols among red lettuce cultivars and identify suitable cultivars for the development and utilization of healthy vegetables. Polyphenols, mineral elements, and antioxidant activity were analyzed in the leaves of six red pigmented lettuce (Lactuca sativa L.) cultivars; thereafter, we assessed the anti-tumor effects of cultivar B-2, which displayed the highest antioxidant activity. Quadrupole-Orbitrap mass spectrometry analysis revealed four classes of polyphenols in these cultivars. The composition and contents of these metabolites varied significantly among cultivars and primarily depended on leaf color. The B-2 cultivar had the highest antioxidant potential than others because it contained the highest levels of polyphenols, especially anthocyanin, flavone, and phenolic acid; furthermore, this cultivar displayed anti-tumor effects against the human lung adenocarcinoma cell line A549, human hepatoma cell line Bel7402, human cancer colorectal adenoma cell line HCT-8, and HT-29 human colon cancer cell line. Hence, the new red-leaf lettuce cultivar B-2 has a distinct metabolite profile, with high potential for development and utilization of natural phytochemical and mineral resources in lettuces and can be used as a nutrient-dense food product.

[The Role of CBS in Injury Time Estimation after Brain Contusion]

OBJECTIVES

To observe the changes of cystathionine β-synthase （CBS） expression in the cerebral cortex after brain contusion at different times.

METHODS

An experimental model of traumatic brain injury （TBI） in mice was established by an improved weight-drop device. Then Western blotting and immunohistochemical examination were used to detect the CBS expression in cerebral cortex around injury at different time points （1 h, 6 h, 12 h, 1 d, 2 d, 3 d, 7 d）.

RESULTS

The results of Western blotting revealed that the expression level of CBS was down-regulated and reached its lowest level at the 3rd days after injury, and then restored to normal level after 7 days. The results of immunohistochemistry showed that CBS was present in the normal brain cortex. CBS expression gradually decreased at the 3rd days after injury, and then restored to normal level after 7 days.

CONCLUSIONS

CBS has the potential to be a reference index for time estimation after brain contusion in forensic practice.

[Present situation and influencing factors on classroom mobile phone dependence syndrome in college students]

Objective: To explore the current situation and influencing factors on Classroom Mobile Phone Dependence Syndrome (CMPDS) among college students, and to provide scientific basis for guiding college students to use mobile phones reasonably and healthily. Methods: Stratified cluster sampling method was used. Students from different majors and different grades in Lanzhou University were included as the research objects. Classes were recognized as a unit in receiving basic field investigation in this questionnaire related study. Informed consent principles were followed and process of survey was anonymously carried out. Results: The overall rate of CMPDS in college students was 8.7%, including 'mild rate' as 6.6% and 'seriously mild rate' as 2.1%. No significant differences were found on genders or grades. Factors as shopping in the classroom shopping (OR=3.720), being bored on courses (OR=1.740), WiFi coverage (OR=1.787), time of practice in the classrooms (OR=1.514), and the total time of daily mobile phone use (OR=1.513) etc, appeared as risk factors related to CMPDS among the college students. However. shooting courseware (OR=0.579) appeared as a protective factor. Conclusions: Rate of CMPDS was high in college students and we suggested to form a joint task force among the college authority, teachers and students to work on the related problems. Hopefully, the serious CMPDS condition will be minimized and both physical and mental health of the college students be improved.

Revealing Extremely Low Energy Amplitude Modes in the Charge-Density-Wave Compound LaAgSb_{2}

Using infrared spectroscopy and ultrafast pump probe measurement, we have studied the two charge-density-wave (CDW) instabilities in the layered compound LaAgSb_{2}. The development of CDW energy gaps was clearly observed by optical spectroscopy, which removed most of the free carrier spectral weight. More interestingly, our time-resolved measurements revealed two coherent oscillations that softened by approaching the two phase transition temperatures, respectively. We addressed that these two oscillations come from the amplitude modes of CDW collective excitations, the surprisingly low energies (0.12 THz and 0.34 THz for the higher and lower temperature ones, respectively) of which are associated with the extremely small nesting wave vectors. Additionally, the amplitude and relaxation time of photoinduced reflectivity of LaAgSb_{2} single crystals stayed unchanged across the CDW phase transitions, which is quite rare and deserves further investigation.

[Ventilator-associated pneumonia among premature infants <34 weeks' gestational age in neonatal intensive care unit in China: a multicenter study]

Objective: To investigate the incidence and pathogen distribution of ventilator-associated pneumonia (VAP) among preterm infants admitted to level Ⅲ neonatal intensive care units (NICU) in China. Method: A prospective study was conducted in 25 level Ⅲ NICU, enrolling all preterm infants <34 weeks gestational age admitted to the participating NICU within the first 7 days of life from May 2015 to April 2016. Chi-square test, t test and Mann-Whitney U test were used for statistical analysis. Result: A total of 7 918 patients were enrolled, within whom 4 623(58.4%) were males. The birth weight was (1 639±415) g and the gestational age was (31.4±2.0) weeks; 4 654(58.8%) infants required non-invasive mechanical ventilation and 2 154(27.2%) required intubation. Of all the mechanically ventilated patients, VAP occurred in 95 patients. The overall VAP rate was 7.0 episodes per 1 000 ventilator days, varying from 0 to 34.4 episodes per 1 000 ventilator days in different centers. The incidence of VAP was 9.6 and 6.0 per 1 000 ventilator days in children's hospitals and maternity-infant hospitals respectively, without significant differences (t=1.002, P=0.327). Gram-negative bacilli (76 strains, 91.6%) were the primary VAP microorganisms, mainly Acinetobacter baumannii (24 strains, 28.9%), Klebsiella pneumonia (23 strains, 27.7%), and Pseudomonas aeruginosa (10 strains, 12.0%). Conclusion: The incidence of VAP in China is similar to that in developed counties, with substantial variability in different NICU settings. More efforts are needed to monitor and evaluate the preventable factors associated with VAP and conduct interventions that could effectively reduce the occurrence of VAP.

Cardiotoxicity evaluation of nine alkaloids from Rhizoma Coptis

PURPOSE

Alkaloids derived from Rhizoma Coptis (RC) has been widely applied to clinical treatments in China. However, the toxicity of RC and the alkaloids from RC remained controversial. The research is designed to clarify the cardiotoxic compounds found in RC.

METHODS

In this study, the real-time cellular analysis cardio system and the high-content analysis were applied to monitor the function of cardiomyocytes (CMs) in the treatment of nine alkaloids in RC. Luciferase-coupled adenosine triphosphate (ATP) assay was used to detect cell viability.

RESULTS

The results showed that berberine, palmatine, berbamine, and oxyberberine were cardiotoxic, which resulted in arrhythmia and cardiac arrest on CMs in a time- and dose-dependent manner. Meanwhile, berbamine and oxyberberine caused shrinkage and detachment on CMs at 10 μM. Cytotoxicity was induced by these two compounds with decline in cell index and ATP depletion. Cardiotoxicity or cytotoxicity was not observed in the other five alkaloids within 10 μM.

CONCLUSION

For the first time, the cardiotoxicity of the nine alkaloids was evaluated to clarify the cardiotoxic components in RC. Furthermore, the experimental evidences were provided to support the safety of drug application.

Involvement of xanthine oxidase and paraoxonase 1 in the process of oxidative stress in nonalcoholic fatty liver disease

Xanthine oxidase (XOD) and paraoxonase 1 (PON1) are important enzymes in redox reactions in vivo, and are predominantly synthesized by the liver. The aim of the present study was to investigate the redox state in nonalcoholic fatty liver disease, and determine the association between the activities of XOD and PON1 and the severity of NAFLD. Sprague‑Dawley rats were randomly divided into control, model and α‑lipoic acid (high and low dose) groups. The rats in the NAFLD model were induced by feeding a high fat diet for 12 weeks and the in vitro cell model of hepatocyte steatosis was induced by treating L‑02 cells with oleic acid for 24 h. The body weight, liver function, lipid and oxidative stress indices, and histological features of the liver were examined in the rats. Compared with the control group, the rats in the NAFLD model group showed impaired liver function, lipid disorders and damage from oxidative stress. The serum activity of XOD increased significantly from the 4th week and was markedly higher, compared with that in the control group, reaching a peak in the 12th week. The activity of PON1 was negatively correlated with that of XOD. Compared with the control cells, the activity of XOD and levels of free‑fatty acids were significantly higher, and the activity of PON1 was significantly lower in the NAFLD L‑02 cell model. All the above indicators were significantly improved by treatment with the antioxidant, α‑lipoic acid. The activities of XOD and PON1 may be promising as markers in a noninvasive approach for detecting the severity of NAFLD clinically. α‑lipoic acid had protective effects on the NAFLD rats, and the potential mechanism may be associated with the inhibition of oxidative stress and lipid peroxidation.

[Clinical features of malignant tumor liver infiltration with liver failure as initial clinical manifestation: a single-center retrospective analysis of 9 cases]

Objective: To investigate the clinical features of patients with liver failure caused by tumor diffuse liver infiltration. Methods: A retrospective analysis was performed for the clinical data of 1008 patients with liver failure who were admitted to our hospital from July 2009 to December 2015. Among these patients, 9 had acute liver failure caused by liver metastasis of malignant tumor. Their clinical manifestations, laboratory markers, clinical progress, and outcome were observed, and the clinical features were summarized. Results: Such patients were manifested as liver enlargement and rapid clinical progression, and imaging examination showed stenosis due to external compression in the inferior vena cava. The patients might be easily misdiagnosed with Budd-Chiari syndrome and had a poor prognosis, with a mortality rate as high as 100%. Conclusion: As for the liver failure patients with unexplained liver enlargement, the possibility of liver metastasis of malignant tumors should be considered. Liver biopsy should be performed as early as possible before the deterioration of liver function, in order to facilitate the targeted therapy for the primary tumor.

[Effects of desmopressin acetate and pituitrin on proliferation, contraction, and secretion of hepatic stellate cells]

Objective: To investigate the effects of desmopressin acetate and pituitrin on the proliferation, contraction, and secretion of hepatic stellate cells (HSCs). Methods: The human HSC cell line LX-2 was selected as the research model. And three groups were designed: blank control group, desmopressin acetate group (three subgroups: 1×10^-10mol/L, 1×10^-9mol/L, and 1×10^-8mol/L desmopressin acetate), and pituitrin group (three subgroups: 0.1 U/L, 1.0 U/L, and 10.0 U/L pituitrin). Water-soluble tetrazolium salt (WST)-1 assay was used to evaluate cell proliferation; collagen gel contraction assay was used to assess cell contraction; enzyme-linked immunosorbent assay (ELISA) was used to identify cell secretion. The data was subjected to one-way analysis of variance. Results: (1) The results of WST-1 assay showed that the values of A₄₅₀in three desmopressin acetate subgroups (1×10^-10mol/L, 1×10^-9mol/L, and 1×10^-8mol/L) were 0.459±0.017, 0.467±0.024, and 0.436±0.015, respectively. And the values of A450 in three pituitrin subgroups (0.1 U/L, 1.0 U/L, and 10.0 U/L) were 0.495±0.011, 0.507±0.015, and 0.501±0.009, respectively. Compared with the control group, the desmopressin acetate at high concentration significantly inhibited the cell proliferation (P< 0.05), but the pituitrin at three different concentrations significantly promoted the cell proliferation (P< 0.05). (2) The collagen gel area ratios in three desmopressin acetate subgroups (1×10^-10mol/L, 1×10^-9mol/L, and 1×10^-8mol/L) were 77.07±4.42, 75.85±3.70, and 72.74±3.92, respectively. And the collagen gel area ratios in three pituitrin subgroups (0.1 U/L, 1.0 U/L, and 10.0 U/L) were 57.83±3.96, 50.28±6.69, and 43.56±7.68, respectively. Compared with the control group, the pituitrin at three different concentrations significantly reduced the collagen gel area (P< 0.01). (3) The matrix metalloproteinase(MMP)-2 concentrations in three desmopressin acetate subgroups (1×10^-10mol/L, 1×10^-9mol/L, and 1×10^-8mol/L) were 13.321±0.098, 12.230±0.153, and 12.061±0.126, respectively. And the MMP-2 concentrations in three pituitrin subgroups (0.1 U/L, 1.0 U/L, and 10.0 U/L) were 12.899±0.150, 13.662±0.152, and 13.698±0.119, respectively. Compared with the control group, the desmopressin acetate at low concentration significantly increased the secretion of MMP-2 (P< 0.01); the desmopressin acetate at high concentration significantly decreased the MMP-2 concentration (P< 0.05); the pituitrin at three different concentrations significantly increased the MMP-2 concentration (P< 0.01). The transforming growth factor-beta 1 (TGF-β1) concentrations in three desmopressin acetate subgroups (1×10^-10mol/L, 1×10^-9mol/L, and 1×10^-8mol/L) were 5.233±0.102, 17.749±0.188, and 36.060±0.227, respectively. And the TGF-β1 concentrations in three pituitrin subgroups (0.1 U/L, 1.0 U/L, and 10.0 U/L) were 15.615±0.099, 38.460±0.209, and 49.053±0.115, respectively. Compared with the control group, desmopressin acetate and pituitrin significantly promoted the secretion of TGF-β1 in a concentration-dependent manner (P< 0.01) and pituitrin had a stronger effect than desmopressin acetate (P< 0.01). Desmopressin acetate and pituitrin had no effect on the secretion of the collagenase type I and III (P> 0.05). Conclusion: Desmopressin acetate and pituitrin can induce the changes in the function and morphology of HSCs and may increase vascular resistance in the hepatic sinus. However, desmopressin acetate has less influence on HSCs than pituitrin.

Effects of different anesthetic approaches on postoperative complications in HIV-infected patients

The aim of this study was to investigate the effects of three different methods of anesthesia on patients with human immunodeficiency virus (HIV) infection, which could lead to an improvement in postoperative outcomes in these patients. A total of 90 patients undergoing an operation while being treated for an HIV infection were included in this study. Patients were divided into three groups (N = 30/group) based on the type of anesthesia administered: general anesthesia, local anesthesia, and combined spinal epidural anesthesia (CSEA). The effects of local infiltration of anesthesia and peripheral nerve block local anesthesia were examined in the local anesthesia group. The CSEA group examined the effects of spinal anesthesia in HIV-infected patients. We compared the vital signs of the three groups during the preoperative period, at incision, and during the postoperative recovery period. The CSEA group had a significantly higher mean preoperative CD4(+) T lymphocyte count compared with the general anesthesia and local anesthesia groups (P < 0.05). We found that the three kinds of anesthesia methods administered to HIV-infected patients could be used with considerable safety and can be selected according to the clinical need and type of surgical procedure.

Computed tomography for the diagnosis of solitary thin-walled cavity lung cancer

BACKGROUND AND AIM

Lung cancer is the most commonly diagnosed neoplasm and the leading cause of cancer-related death worldwide. Despite the high incidence of lung cancer, the diagnosis of solitary thin-walled cavity lung cancer is rare. The aim of this review is to explore the potentials of computed tomography (CT) as diagnostic tool for solitary thin-walled cavity lung cancer.

METHOD

The literature search was made in electronic databases including PudMed, Ovid SP, Embase, Web of Sciences, EBSCO and Wiley online by using relevant key terms. Because of the rarity of the subject, no precise exclusion or inclusion criteria were used for article selection and the outcome dissemination was decided to be more descriptive rather than quantitative.

RESULTS

The detection of cavitation in lungs is frequently done utilizing chest radiographs CT scans. However, the diagnostic challenge remains the accurate detection of solitary thin-walled cavity lung cancer among the prevalence of cavitary lung lesions in multiple thoracic disorders including benign disorders, infectious disease and malignant tumors. Moreover, an accurate diagnosis of solitary thin-walled cavity lung cancer is further complicated by its subjective classification within the literature. In order to facilitate early diagnosis of this disease and circumvent the need for more invasive tests that may not be warranted, the overarching goal is to establish definitive radiological features of lung cavities that are indicative of malignancy. Herein, we describe the benefits of using CT to identify and diagnose solitary thin-walled cavity lung cancer, as well as explore the underlying mechanisms that contribute to thin-walled cavity formation in oncology patients.

CONCLUSION

CT is the best modality for the noninvasive differentiation between malignant and nonmalignant cavities as it provides reliable information regarding the morphology and density of lesions. Besides, CT densitometry can efficiently detect the calcifications in lesions.

High color rending index and high-efficiency white organic light-emitting diodes based on the control of red phosphorescent dye-doped hole transport layer

We have investigated the transport characteristics of red phosphorescent dye bis(1-(phenyl)isoquinoline) iridium (III) acetylanetonate (Ir(piq)₂acac) doped 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), and found that the increasing doping ratio was facilitated to improve the ability of hole transporting. A high color rendering index (CRI) and high-efficiency WOLED was achieved by employing Ir(piq)₂acac doped TCTA film as an effective red emissive layer due to the generation of charge transfer complex (CTC) at the interface. The relative proportion in red: green: blue emission intensity can be controlled by the CTC concentration to obtain high CRI WOLEDs. The WOLED with an optimal red dye doping concentration of 5 wt% exhibits a high CRI of 89 and a power efficiency of 31.2 lm/W and 27.5 lm/W at the initial luminance and 100 cd/m², respectively. The devices show little variation of the Commission Internationale de I'Eclairage coordinates in a wide range of luminance.

Mild hypothermia attenuates mitochondrial oxidative stress by protecting respiratory enzymes and upregulating MnSOD in a pig model of cardiac arrest

Mild hypothermia is the only effective treatment confirmed clinically to improve neurological outcomes for comatose patients with cardiac arrest. However, the underlying mechanism is not fully elucidated. In this study, our aim was to determine the effect of mild hypothermia on mitochondrial oxidative stress in the cerebral cortex. We intravascularly induced mild hypothermia (33°C), maintained this temperature for 12 h, and actively rewarmed in the inbred Chinese Wuzhishan minipigs successfully resuscitated after 8 min of untreated ventricular fibrillation. Cerebral samples were collected at 24 and 72 h following return of spontaneous circulation (ROSC). We found that mitochondrial malondialdehyde and protein carbonyl levels were significantly increased in the cerebral cortex in normothermic pigs even at 24 h after ROSC, whereas mild hypothermia attenuated this increase. Moreover, mild hypothermia attenuated the decrease in Complex I and Complex III (i.e., major sites of reactive oxygen species production) activities of the mitochondrial respiratory chain and increased antioxidant enzyme manganese superoxide dismutase (MnSOD) activity. This increase in MnSOD activity was consistent with the upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA and protein expressions, and with the increase of Nrf2 nuclear translocation in normothermic pigs at 24 and 72 h following ROSC, whereas mild hypothermia enhanced these tendencies. Thus, our findings indicate that mild hypothermia attenuates mitochondrial oxidative stress in the cerebral cortex, which may be associated with reduced impairment of mitochondrial respiratory chain enzymes, and enhancement of MnSOD activity and expression via Nrf2 activation.

Shen-fu injection attenuates postresuscitation lung injury in a porcine model of cardiac arrest

OBJECTIVE

To investigate the effects of Shen-Fu injection (SFI) on postresuscitation lung injury in a porcine model of cardiac arrest.

METHODS

Twenty-four anaesthetised male Landrace pigs were subjected to 4 min of untreated ventricular fibrillation (VF), followed by standard cardiopulmonary resuscitation. Sixteen successfully resuscitated pigs were randomised into two groups (eight pigs per group); one group received an SFI infusion and the other group received a normal saline infusion, at an infusion rate of 0.24 mg/min from 15 min after the return of spontaneous circulation (ROSC) until 6h after ROSC.

RESULTS

Oxygenation index, respiratory index, oxygen delivery, oxygen consumption, oxygen extraction, dynamic lung compliance, airway resistance, external vascular lung water index, and pulmonary vascular permeability index at 15 min, 30 min, 1h, 2h, 4h, and 6h after ROSC were all worse than baseline in the saline group, and were all better in the SFI group than in the saline group. The pulmonary protective effects of SFI were further confirmed by histopathological and ultrastructural observations of lung tissue. SFI infusion resulted in lower apoptosis index, caspase-3 protein expression, and malondialdehyde content of lung tissue after ROSC, and increased Bcl-2 protein expression and superoxide dismutase, Na+ -K+ -ATPase, and Ca2+ -ATPase activity compared with the saline group.

CONCLUSION

Shen-Fu injection can attenuate postresuscitation lung injury through suppression of lung cell apoptosis and improvement of energy metabolism and antioxidant capacity.

Molecular mechanisms of therapeutic hypothermia on neurological function in a swine model of cardiopulmonary resuscitation

OBJECTIVE

To explore the molecular mechanisms by which mild hypothermia following resuscitation improves neurological function in a porcine model of cardiac arrest.

METHODS

Thirty-three inbred Chinese Wuzhishan (WZS) minipigs were used. After 8 min of untreated ventricular fibrillation (VF), the surviving animals (n=29) were randomly divided into two groups including serum group (n=16) and molecular group (n=13). Serum group animals were used to measure porcine-specific tumour necrosis factor-alpha (TNF-α), interleukin (IL-6, IL-10), matrix metalloproteinase (MMP9), Aquaporin-4 (AQP4), tissue inhibitor to metalloproteinase-1 (TIMP1), neuron-specific enolase (NSE) and S100B at 0.5 h, 6 h, 12 h, 24 h and 72h recovery by enzyme-linked immunosorbent assay (ELISA). Molecular group animals were used to measure cerebral cortex messenger RNA (mRNA) and protein expression of nuclear factor-κB (NF-κB), MMP9 and AQP4 by real-time (RT) quantitative polymerase chain reaction (PCR) and Western blotting at 24 h and 72 h recovery. Animals were further divided into either normothermia or hypothermia groups. Hypothermia (33°C) was maintained for 12 h using an endovascular cooling device. Swine neurologic deficit scores (NDS) were used to evaluate neurological function at 24-h and 72-h recovery.

RESULTS

Twenty-nine of the 33 (87.9%) animals were successfully resuscitated. The hypothermia group exhibited higher survival rates at 24 h (75%) and 72 h (62.5%) compared to the normothermia group (37.5% and 25%, respectively). Hypothermia markedly inhibited expression of NF-κB, TNF-α, MMP9 and NSE, and promoted expression of TIMP1 (P<0.01). The mean NDS at 24-h and 72-h recovery was 112.5 and 61, respectively, in the hypothermic group, and 230 and 207.5, respectively, in the normothermia group.

CONCLUSION

Brain protection induced by hypothermia involves inhibition of inflammatory and brain edema pathways.

Relation between prognosis and expression of metastasis-associated protein 1 in stage I non-small cell lung cancer

Metastasis-associated protein 1 (MTA1 protein) has been reported to be correlated with the biological behavior and prognosis of several malignant carcinomas. We hypothesized that stage I non-small cell lung cancer (NSCLC) patients with MTA1 protein overexpression would be more likely to have a poor prognosis. Therefore, we tested the expression of MTA1 protein in 60 stage I NSCLC and 30 paracarcinous normal lung tissues using the streptavidin-perosidase method. The Kaplan-Meier method was used to calculate the survival rate, and Cox regression analysis was performed to identify prognostic risk factors. MTA1 protein overexpression was detected in 22 stage I NSCLC tissues in this study. Tumor differentiation and tumor diameter were significantly associated with MTA1 protein overexpression, while not correlated with age, sex, pathological type or smoking status. The five-year survival rate of patients with MTA1 protein overexpression was significantly lower than that of those without expression (40.9% vs. 84.1%; P<0.001). The results of multivariate analysis confirmed that MTA1 protein overexpression was an independent prognostic factor (risk ratio=5.23, P=0.007). These findings demonstrated MTA1 might be a prognostic factor in NSCLC.

Lifetime prevalence of suicide ideation, plan, and attempt in metropolitan China

OBJECTIVE

This is the first community-based epidemiological study examining the prevalence of suicidal behaviors, their transitional pathways, and their relationship with mental disorders in metropolitan China.

METHOD

Suicidal behaviors, including ideation, plans, and attempts were assessed by face-to-face household interviews among 5201 respondents in Beijing and Shanghai in 2001-2002. Lifetime prevalence and risk factors were examined using multivariate discrete-time survival models.

RESULTS

The lifetime prevalence estimates of suicidal ideation, plans, and attempts were 3.1%, 0.9%, and 1.0% respectively. Among suicide ideators, the conditional probability of ever making a plan and an attempt was 29.5% and 32.3% respectively. Progression from ideation to plan and attempt was the highest during the first year after onset. Suicide attempt was predicted by young adulthood, being unmarried, recent onset of ideation and plan, and the presence of mental disorders, especially mood disorder.

CONCLUSION

Suicidal behaviors in metropolitan China exhibit a low prevalence and an epidemiological profile resembling that found in Western countries.

Delay in initial treatment contact after first onset of mental disorders in metropolitan China

OBJECTIVE

There has been no community-based research on treatment delay among people with mental disorders in China. This study examines lifetime treatment and treatment delay in metropolitan China.

METHOD

A multi-stage probability survey of 5201 respondents was administered in Beijing and Shanghai. Age of first treatment contact after onset of each of the three lifetime DSM-IV/CIDI disorder classes was compared with retrospective information on age of disorder onset. Length and predictors of treatment delay were examined using survival analysis.

RESULTS

Survival curves estimate that 44.7%, 25.7%, and 7.9% of people with anxiety, substance, and mood disorders, respectively, will ever make treatment contact. Delays in first treatment contact of anxiety (21 years) and substance (17 years) disorders are longer than that of mood disorders (1 year). These delays are largely unrelated to sociodemographic variables.

CONCLUSION

Failure to receive treatment is a pervasive phenomenon among people with mental disorders in metropolitan China.

A new ultrasound instrument for in vivo microimaging of mice

We report here on the design and evaluation of the first high-frequency ultrasound (US) imaging system specifically designed for microimaging of the mouse. High-frequency US or US biomicroscopy (UBM) has the advantage of low cost, rapid imaging speed, portability and high resolution. In combination with the ability to provide functional information on blood flow, UBM provides a powerful method for the investigation of development and disease models. The new UBM imaging system is demonstrated for mouse development from day 5.5 of embryogenesis through to the adult mouse. At a frequency of 40 MHz, the resolution voxel of the new mouse scanner measures 57 microm x 57 microm x 40 microm. Duplex Doppler provides blood velocity sensitivity to the mm per s range, consistent with flow in the microcirculation, and can readily detect blood flow in the embryonic mouse heart, aorta, liver and placenta. Noninvasive UBM assessment of development shows striking similarity to invasive atlases of mouse anatomy. The most detailed noninvasive in vivo images of mouse embryonic development achieved using any imaging method are presented.

[Repair and reconstruction of radial nerve injury]

OBJECTIVE

To investigate the reparative method and effect of radial nerve injury.

METHODS

From 1990 to 2000, 50 cases with radial nerve injuries were adopted in this study. Among them, there were 38 males and 12 females, aged from 5 to 65 years. For the 50 cases, there were 28 cases with complete nerve rupture, 3 cases with incomplete nerve rupture, 10 cases with compressive injury, 5 cases with contusion injury and 4 cases with defect and irreversible injury. All the patients were treated with radial nerve exploration in 1 hour to 6 months after injury. 31 cases were treated with nerve anastomosis, 10 cases with nerve lytic operation, 4 cases with tendon transfer and 5 cases with palliative treatment.

RESULTS

All the cases were followed up 3 months to 10 years. The curative effect was assessed according to Highest grade method. There were excellent and good results in 46 cases, moderate results in 4 cases.

CONCLUSION

It is necessary to explore and repair the radial nerve injury immediately after the diagnosis being confirmed. If the function of radial nerve could not recover in 6 months, tendon transfer should be carried out to reconstruct the extension of elbow, thumb and fingers.

Antibody-based resistance to plant pathogens

Plant diseases are a major threat to the world food supply, as up to 15% of production is lost to pathogens. In the past, disease control and the generation of resistant plant lines protected against viral, bacterial or fungal pathogens, was achieved using conventional breeding based on crossings, mutant screenings and backcrossing. Many approaches in this field have failed or the resistance obtained has been rapidly broken by the pathogens. Recent advances in molecular biotechnology have made it possible to obtain and to modify genes that are useful for generating disease resistant crops. Several strategies, including expression of pathogen-derived sequences or anti-pathogenic agents, have been developed to engineer improved pathogen resistance in transgenic plants. Antibody-based resistance is a novel strategy for generating transgenic plants resistant to pathogens. Decades ago it was shown that polyclonal and monoclonal antibodies can neutralize viruses, bacteria and selected fungi. This approach has been improved recently by the development of recombinant antibodies (rAbs). Crop resistance can be engineered by the expression of pathogen-specific antibodies, antibody fragments or antibody fusion proteins. The advantages of this approach are that rAbs can be engineered against almost any target molecule, and it has been demonstrated that expression of functional pathogen-specific rAbs in plants confers effective pathogen protection. The efficacy of antibody-based resistance was first shown for plant viruses and its application to other plant pathogens is becoming more established. However, successful use of antibodies to generate plant pathogen resistance relies on appropriate target selection, careful antibody design, efficient antibody expression, stability and targeting to appropriate cellular compartments.

A minimal cytoplasmic subdomain of the erythropoietin receptor mediates p70 S6 kinase phosphorylation

Erythropoietin (EPO) is a lineage-restricted growth factor that is required for erythroid proliferation and differentiation. EPO stimulates the phosphorylation and activation of p70 S6 kinase (p70 S6K), which is required for cell cycle progression. Here, the minimal cytoplasmic domains of the EPO receptor (EPO-R) required for p70 S6K activation were determined.Ba/F3 cells were stably transfected with wild-type (WT) EPO-R or EPO-R carboxyl-terminal deletion mutants, designated by the number of amino acids deleted from the cytoplasmic tail (-99, -131, -221). Transfected cells were growth factor deprived and then stimulated with EPO. p70 S6K, JAK2, IRS-2, and ERK1/2 phosphorylation/activation were examined. The ability of transfected 3-phosphoinositide-dependent protein kinase 1 (PDK1) to reconstitute p70 S6K phosphorylation in EPO-R mutants also was determined. Phosphorylation and activation of p70 S6K, JAK2, IRS-2, and ERK1/2 in Ba/F3 cells transfected with EPO-R-99 or EPO-R-99Y343F were similar to WT EPO-R. In contrast, EPO-dependent p70 S6K phosphorylation/activation, as well as IRS-2 and ERK1/2 phosphorylation, were minimal or absent in cells transfected with EPO-R-131 or EPO-R-221. JAK2 phosphorylation was reduced significantly in cells transfected with EPO-R-131 and abolished with EPO-R-221. To examine the role of PDK1, a kinase known to phosphorylate p70 S6K, Ba/F3 EPO-R-131 cells were transiently transfected with PDK1. WT constitutively active PDK1 restored p70 S6K phosphorylation in Ba/F3 EPO-R-131 cells but not in Ba/F3 EPO-R-221 cells. The results demonstrate that a minimal cytoplasmic subdomain of the EPO-R extending between -99 and -131 is required for p70 S6K phosphorylation and activation. The results also demonstrate that PDK1 is a critical component in this signaling pathway, which requires the presence of domains between -131 and -221 for its activation of p70 S6K.

Recombinant single chain cardiac troponin I-C polypeptides: superior calibration and control materials for cardiac troponin I immunoassays

There has been a need to create stable and reproducible calibration and control materials for cardiac troponin I assays. Free troponin I, native or recombinant, has been known to be unstable, while troponin CI complex can be easily dissociated in low concentrations or in the presence of chelating agents. In order to overcome these difficulties, two single chain troponin I-C polypeptides have been engineered and expressed separately in Escherichia coli. One consists of a full-length of human cardiac troponin I and C, termed as ScTnI-C and the other consists of a stable fragment (aa28-110) of human cardiac troponin I and a full-length troponin C, termed as ScTnI-C-2. Both ScTnI-C and ScTnI-C-2 were purified to homogeneity by affinity chromatography using anti-cTnI monoclonal antibodies. ScTnI-C and ScTnI-C-2 have apparent molecular weights of 45 kD and 30 kD by SDS-PAGE, respectively. Stability studies by Stratus showed that ScTn I-C and ScTnI-C-2 were stable for 4 months at 2-8 degrees C and at least one year at -20 degrees C. When incubated in human serum at 37 degrees C, ScTnI-C-2 was more resistant to proteolysis than ScTnI-C. ScTnI-C can be recognized by all commercial TnI immunoassays with excellent activity. ScTnI-C-2 can be recognized by all immunoassays that target the stable region of cardiac troponin I. Judging by their performances, ScTnI-C and ScTnI-C-2 are both superior materials to be used as calibrators and controls in clinical laboratories.

Renal expression of the sodium/phosphate cotransporter gene, Npt2, is not required for regulation of renal 1 alpha-hydroxylase by phosphate

Several reports have suggested that the regulation of renal 1,25-dihydroxyvitamin D [1,25-(OH)(2)D] synthesis by extracellular phosphate (Pi) is dependent on normal transepithelial Pi transport by the renal tubule. Mice homozygous for the disrupted Na/Pi cotransporter gene Npt2 (Npt2(-/-)) exhibit renal Pi wasting, an approximately 85% decrease in renal brush border membrane Na/Pi cotransport, hypophosphatemia, and an increase in serum 1,25-(OH)(2)D concentration. We undertook 1) to determine the mechanism for the increased circulating levels of 1,25-(OH)(2)D in Npt2(-/-) mice and 2) to establish whether renal 1alpha-hydroxylase was appropriately regulated by dietary Pi in the absence of Npt2 gene expression. On a control diet, the 2.5-fold increase in the serum 1,25-(OH)(2)D concentration in Npt2(-/-) mice, relative to that in Npt2(+/+) littermates, is associated with a corresponding increase in renal mitochondrial 25-hydroxyvitamin D-1 alpha-hydroxylase (1 alpha-hydroxylase) activity and messenger RNA (mRNA) abundance. A low Pi diet elicits an increase in serum 1,25-(OH)(2)D concentration, renal 1alpha-hydroxylase activity, and mRNA abundance in Npt2(+/+) and Npt2(-/-) mice to similar levels in both mouse strains. A high Pi diet has no effect on serum 1,25-(OH)(2)D concentration, renal 1 alpha-hydroxylase activity, or mRNA abundance in Npt2(+/+) mice, but normalizes these parameters in Npt2(-/-) mice. In addition, renal 24-hydroxylase mRNA abundance is significantly reduced in Npt2(-/-) mice compared with that in Npt2(+/+) mice under all dietary conditions. In summary, we demonstrate that 1) increased renal synthesis of 1,25-(OH)(2)D is responsible for the increased serum 1,25-(OH)(2)D concentration in Npt2(-/-) mice; and 2) renal 1alpha-hydroxylase gene expression is appropriately regulated by dietary manipulation of serum Pi in both Npt2(+/+) and Npt2(-/-) mice. Thus, intact renal Na/Pi cotransport is not required for the regulation of renal 1alpha-hydroxylase by Pi.

GST fusion proteins cause false positives during selection of viral movement protein specific single chain antibodies

Glutathione S-transferase (GST) fusion proteins are used frequently for investigating protein-protein and protein-DNA interactions. The present study demonstrates that the use of GST fusion proteins caused false positives during selection of phage-displayed single-chain antibody fragments (scFvs) specific for three domains of the movement protein (NS(M)) of tomato spotted wilt virus (TSWV). To identify and exclude the false positives when using GST as a fusion partner linked to the antigen of interest, indirect phage enzyme-linked immunosorbent assay (ELISA) was compared with capture phage ELISA. Of 210 enriched phage clones, indirect phage ELISA identified 106 clones specific for binding to GST-domain fusions but not to GST. In contrast, using capture phage ELISA, all 106 selected clones were identified as false positives, reacting with the GST fusion proteins and GST. This was confirmed by characterization of soluble scFv antibodies. The data indicate that GST fusion proteins seem unsuitable for screening of phage-displayed antibody fragments and it is essential to use capture phage ELISA, instead of the indirect phage ELISA used commonly to exclude false positives in characterization of selected clones with GST fusion proteins.

The nuclear migration gene NudC and human hematopoiesis

The filamentous fungus Aspergillus nidulans nudC (nuclear distribution C) gene is required for movement of nuclei following mitosis and for normal colony growth. It is highly conserved, structurally and functionally, throughout most of evolution. The human homolog, called HnudC, has been cloned and has an important role in cell proliferation. In hematopoiesis, HNUDC is highly expressed in early hematopoietic precursors and declines during normal differentiation. Stimulation of proliferation of the erythroleukemia cell line TF-1 with GM-CSF enhances HnudC protein and mRNA expression and treatment with antisense (but not sense) oligonucleotides to HnudC mRNA significantly reduces cell division. A significant increase in HNUDC is present in bone marrow aspirates from patients with acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) compared to the level in normal cellular counterparts, demonstrating dysregulated expression in leukemia. These data support the conclusion that HnudC plays a functional role in promoting hematopoietic cell growth and that it is involved in leukemogenesis.

Expression of angiotensin II type I receptor on erythroid progenitors of patients with post transplant erythrocytosis

BACKGROUND

The pathogenesis of posttransplant erythrocytosis (PTE) has been elusive. Angiotensin converting enzyme inhibitors (ACEI) are efficacious in lowering the hematocrit of patients with PTE and angiotensin II (AII) type I receptors (AT1R) were recently detected on red blood cell precursors, burst-forming unit-erythroid- (BFU-E) derived cells. The purpose of this study was to determine whether there is increased expression of the AT1R on BFU-E-derived cells of patients with PTE, which might contribute to the pathogenesis of PTE.

METHODS

Twelve healthy volunteers and 25 transplant recipients (13 patients with and 12 without PTE) were studied. BFU-E from peripheral blood were cultured in methylcellulose and BFU-E-derived colonies were harvested on day 10. Western blotting was used to detect AT1R and erythropoietin receptor (EpoR) expression. Intracellular free calcium in response to AII and erythropoietin (Epo) was measured with digital video imaging.

RESULTS

There were no differences between transplant patients, with and without PTE, with respect to weight, age, sex, blood pressure, serum creatinine, circulating renin, angiotensin II, and Epo levels. Hematocrit, red blood cell number, BFU-E-derived colony number,and size were significantly increased in PTE compared with other two groups. AT1R expression was increased by 44% on the erythroid progenitors of PTE versus non posttransplant erythrocytosis patients and by 32% in PTE patients versus normal volunteers. AT1R expression correlated significantly with the hematocrit in PTE (Spearman r=0.68, P=0.01). In contrast, EpoR expression was equivalent in all groups. The AT1R was functional since a significant increase in [Ca(i)] was observed in Fura-2 loaded day 10 cells when stimulated with AII (182%, P<0.0001).

CONCLUSION

An increase in AT1R density was observed in erythroid precursors of transplant patients with PTE compared to those without PTE and normal volunteers, and the level of AT1R expression in PTE correlated significantly with the hematocrit. In contrast, EpoR expression was not different in PTE compared with non posttransplant erythrocytosis or normal controls. This study supports a role for the AT1 receptor signaling pathway in the pathogenesis of PTE.

[Studies on the construction and expression of recombinant human fusion gene Nm23-H1/HbFGF in Escherichia coli]

First, a piece of intermediate nucleic acid chain was designed according to the nucleic acid sequences of Nm23-H1 and HbFGF cDNA, then it was combined with the upstream primer of Nm23-H1 or the downstream primer of HbFGF to perform Polymerase Chain Reaction (PCR) respectively. The fusion gene Nm23-H1/HbFGF was constructed by four steps of PCR, and it was cloned into the plasmid vector pBV220. The recombinant was induced at 42 degrees C and analyzed by SDS-PAGE. Results show that the fusion gene Nm23-H1/HbFGF highly expresses its product in inclusion body in E. coli BL21(DE3). The expressing product is 14% of the total bacterial protein and it is 34 kD. ELISA assay and Western blot indicate that the inclusion body contains antigens of Nm23-H1 and HbFGF. By denaturation, renaturation and purification, the inclusion body was purified. Determination and biological activity assay show that the purified product contains two kinds of antigens which have biological activities of Nm23-H1 and HbFGF. All these data establish good base to study the tumor suppressor activity and oncogenicity of the fusion gene Nm23-H1/HbFGF in eukaryocyte.

Inhibitory effects of 8-(N,N-diethylamino)-n-octyl-3,4,5-trimethoxybenzoate (TMB-8) on intracellular Ca2+ elevated by neurotransmitters in brain cells

AIM

To study the effects of TMB-8 on [Ca2+]i elevation induced by neurotransmitters in dissociated brain cells.

METHODS

The brain cell suspension was made using a gentle trituration for 1 min with a polished pipette. The changes of [Ca2+]i were detected by the fluorescent indicator, Fura 2-AM.

RESULTS

In the presence of extracellular Ca2+ 1.3 mmol.L-1, sodium glutamate (Glu), histamine (His), and serotonin (5-HT) markedly increased the [Ca2+]i which were reduced by TMB-8 30 mumol.L-1. TMB-8 3 mumol.L-1 produced inhibitory effects on the increase of [Ca2+]i by His and 5-HT in a Ca(2+)-free Hanks' solution. The increase of [Ca2+]i by His and 5-HT was reduced to control level by TMB-8 10 mumol.L-1.

CONCLUSION

TMB-8 inhibited the [Ca2+]i elevation induced by Glu, 5-HT, and His in brain cells.

Identification of the erythropoietin receptor domain required for calcium channel activation

Erythropoietin (Epo) activates a voltage-independent Ca2+ channel that is dependent on tyrosine phosphorylation. To identify the domain(s) of the Epo receptor (Epo-R) required for Epo-induced Ca2+ influx, Chinese hamster ovary (CHO) cells were transfected with wild-type or mutant Epo receptors subcloned into pTracer-cytomegalovirus vector. This vector contains an SV40 early promoter, which drives expression of the green fluorescent protein (GFP) gene, and a cytomegalovirus immediate-early promoter driving expression of the Epo-R. Successful transfection was verified in single cells by detection of GFP, and intracellular Ca2+ ([Ca]i) changes were simultaneously monitored with rhod-2. Transfection of CHO cells with pTracer encoding wild-type Epo-R, but not pTracer alone, resulted in an Epo-induced [Ca]i increase that was abolished in cells transfected with Epo-R F8 (all eight cytoplasmic tyrosines substituted). Transfection with carboxyl-terminal deletion mutants indicated that removal of the terminal four tyrosine phosphorylation sites, but not the tyrosine at position 479, abolished Epo-induced [Ca]i increase, suggesting that tyrosines at positions 443, 460, and/or 464 are important. In CHO cells transfected with mutant Epo-R in which phenylalanine was substituted for individual tyrosines, a significant increase in [Ca]i was observed with mutants Epo-R Y443F and Epo-R Y464F. The rise in [Ca]i was abolished in cells transfected with Epo-R Y460F. Results were confirmed with CHO cells transfected with plasmids expressing Epo-R mutants in which individual tyrosines were added back to Epo-R F8 and in stably transfected Ba/F3 cells. These results demonstrate a critical role for the Epo-R cytoplasmic tyrosine 460 in Epo-stimulated Ca2+ influx.