Personalised follow-up and management schema for patients with screen-detected pulmonary nodules: A dynamic modelling study

BACKGROUND

Selecting the time target for follow-up testing in lung cancer screening is challenging. We aim to devise dynamic, personalized lung cancer screening schema for patients with pulmonary nodules detected through low-dose computed tomography.

METHODS

We developed and validated dynamic models using data of pulmonary nodule patients (aged 55-74 years) from the National Lung Screening Trial. We predicted patient-specific risk profiles at baseline (R0) and updated the risk evaluation results in repeated screening rounds (R1 and R2). We used risk cutoffs to optimize time-dependent sensitivity at an early decision point (3 months) and time-dependent specificity at a late decision point (1 year).

RESULTS

In validation, area under receiver operating characteristic curve for predicting 12-month lung cancer onset was 0.867 (95 % confidence interval: 0.827-0.894) and 0.807 (0.765-0.948) at R0 and R1-R2, respectively. The personalized schema, compared with National Comprehensive Cancer Network (NCCN) guideline and Lung-RADS, yielded lower rates of delayed diagnosis (1.7% vs. 1.7% vs. 6.9 %) and over-testing (4.9% vs. 5.6% vs. 5.6 %) at R0, and lower rates of delayed diagnosis (0.0% vs. 18.2% vs. 18.2 %) and over-testing (2.6% vs. 8.3% vs. 7.3 %) at R2. Earlier test recommendation among cancer patients was more frequent using the personalized schema (vs. NCCN: 29.8% vs. 20.9 %, p = 0.0065; vs. Lung-RADS: 33.2% vs. 22.8 %, p = 0.0025), especially for women, patients aged ≥65 years, and part-solid or non-solid nodules.

CONCLUSIONS

The personalized schema is easy-to-implement and more accurate compared with rule-based protocols. The results highlight value of personalized approaches in realizing efficient nodule management.

The influence of respiratory movement on preoperative CT-guided localization of lung nodules

AIM

To evaluate the motion amplitude of lung nodules in different locations during preoperative computed tomography (CT)-guided localization, and the influence of respiratory movement on CT-guided percutaneous lung puncture.

MATERIALS AND METHODS

A consecutive cohort of 398 patients (123 men and 275 women with a mean age of 53.9 ± 10.7 years) who underwent preoperative CT-guided lung nodule localization from May 2021 to Apr 2022 were included in this retrospective study. The respiratory movement-related nodule amplitude in the cranial-caudal direction during the CT scan, characteristics of patients, lesions, and procedures were statistically analyzed. Univariate and multivariate logistic regression analyses were used to evaluate the influence of these factors on CT-guided localization.

RESULTS

The nodule motion distribution showed a statistically significant correlation within the upper/middle (lingular) and lower lobes (p<0.001). Motion amplitude was an independent risk factor for CT scan times (p=0.011) and procedure duration (p=0.016), but not for the technical failure rates or the incidence of complications. Puncture depth was an independent risk factor for the CT scan times, procedure duration, technical failure rates, and complications (p<0.01). Female, prone, and supine (as opposed to lateral) positions were significant protective factors for pneumothorax, while the supine position was an independent risk factor for parenchymal hemorrhage (p=0.025).

CONCLUSION

Respiratory-induced motion amplitude of nodules was greater in the lower lobes, resulting in more CT scan times/radiation dose and longer localization duration, but showed no statistically significant influence on the technical success rates or the incidence of complications during preoperative CT-guided localization.

SIRT6 Improves Hippocampal Neurogenesis Following Prolonged Sleep Deprivation Through Modulating Energy Metabolism in Developing rats

OBJECTIVE

Prolonged sleep deprivation is known to have detrimental effects on the hippocampus during development or in adulthood. Furthermore, it is well-established that sleep deprivation disrupts energy metabolism broadly. SIRT6 is a critical regulator of energy metabolism in both central and peripheral tissues. This study aims to investigate the role of SIRT6 in modulating hippocampal neurogenesis following sleep deprivation during development, and elucidate the underlying mechanism.

METHODS

Male Sprague-Dawley rats, aged three weeks, were subjected to 2 weeks of sleep deprivation using the modified multiple platform method. Metabolomic profiling was carried out using the liquid chromatography-electrospray ionization-tandem mass spectrometry (LC‒ESI‒MS/MS). To investigate the role of SIRT6 in energy metabolism, the rats were administered with either the SIRT6-specific inhibitor, OSS128167, or SIRT6-overexpressing adeno-associated virus (AAV). Hippocampal neurogenesis was assessed by immunostaining with markers for neural stem cells (SOX2), immature neurons [doublecortin (DCX)] and newborn cells (BrdU). Sparse labeling of adult neurons was used to determine the density of dendritic spines in the dentate gyrus (DG). The Y-maze and novel object recognition (NOR) tests were performed to evaluate the spatial and recognition memory. SIRT6 expression was examined using immunofluorescence and western blotting (WB). The inhibition of SIRT6 was confirmed by assessing the acetylation of histone 3 lysine 9 (aceH3K9), a well-known substrate of SIRT6, through WB.

RESULTS

Sleep deprivation for a period of two weeks leads to inhibited hippocampal neurogenesis, reduced density of dendritic spines in the DG, and impaired memory, accompanied by decreased SIRT6 expression and disrupted energy metabolism. Similar to sleep deprivation, administration of OSS128167 significantly decreased energy metabolism, leading to reduced neurogenesis and memory dysfunction. Notably, the abnormal hippocampal energy metabolism, neurogenetic pathological changes and memory dysfunction caused by sleep deprivation were alleviated by SIRT6 overexpression in the DG.

CONCLUSION

Our results suggest that SIRT6 plays a critical role in maintaining energy metabolism homeostasis in the hippocampus after sleep deprivation, promoting hippocampal neurogenesis and enhancing memory during development.

Prediction of acute toxicity to Daphnia magna and interspecific correlation: a global QSAR model and a Daphnia-minnow QTTR model

Acute toxicity is an important basis for the assessment of hazardous chemicals, but currently there is a huge data gap in chemical toxicity information. The in silico Quantitative Structure Activity Relationship (QSAR) models can use the existing experimental data information to predict the missing chemical toxicity information data and thus reduce animal testing. In the present study, a global QSAR model for the prediction of acute Daphnia magna toxicity has been developed based on the five principles proposed by the Organization for Economic Co-operation and Development (OECD). Moreover, a Daphnia-minnow (referring specifically to the fathead minnow) Quantitative Toxicity-Toxicity Relationship (QTTR) prediction model has been developed based on the present study and our previous work on fathead minnow (Pimephales promelas). Both the QSAR and QTTR prediction models have good goodness-of-fit, robustness, and predictive ability. Finally, the acute toxicity mode of action (MOA) for fathead minnow and Daphnia magna was compared by toxicity ratio based on interspecies toxicity data. By comparison, Daphnia magna was found more sensitive to anilines and phosphorothioates than fathead minnow. The present models can fill the acute toxicity data gap and contribute to the chemicals risk assessment and priority setting.

A new antisarcoma strategy: multisubtype heat shock protein/peptide immunotherapy combined with PD-L1 immunological checkpoint inhibitors

Osteosarcoma, a common malignant tumor in orthopedics, often has a very poor prognosis after lung metastasis. Immunotherapy has not achieved much progress in the treatment because of the characteristics of solid tumors and immune environment of osteosarcoma. The tumor environment is rather essential for sarcoma treatment. Our previous study demonstrated that heat shock proteins could be used as antitumor vaccines by carrying tumor antigen peptides, and we hypothesize that an anti-osteosarcoma effect may be increased with an immune check point inhibitor (PD-L1 inhibitor) as a combination treatment strategy. The present study prepared a multisubtype mixed heat shock protein osteosarcoma vaccine (mHSP/peptide vaccine) and concluded that the mHSP/peptide vaccine was more effective than a single subtype heat shock protein, like Grp94. Therefore, we used the mHSP/peptide vaccine in combination with a PD-L1 inhibitor to treat osteosarcoma, and the deterioration of osteosarcoma was effectively hampered. The mechanism of combined therapy was investigated, and AKT expression participates with sarcoma lung metastasis. This study proposed an antisarcoma strategy via stimulation of the immune system as a further alternative approach for sarcoma treatment and elucidated the mechanism of combined therapy.

Role of the active cycle of breathing technique combined with phonophoresis for the treatment of patients with chronic obstructive pulmonary disease (COPD): study protocol for a preliminary randomized controlled trial

Background

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease characterized by coughing, the production of excess sputum, and dyspnea. Patients with excessively thick sputum may have frequent attacks or develop more serious disease. The guidelines recommend airway clearance for patients with excessive sputum who are hospitalized with COPD. The active cycle of breathing technique is the most common non-pharmacological airway clearance technique used by physiotherapists. However, the effectiveness of the technique is not always guaranteed. Active cycle of breathing techniques require the initial dilution of the sputum, usually by inhalation drugs, which may have limited effects. Recent studies have found that phonophoresis decreases inflammation, suggesting the potential of the combined usage of active cycle of breathing techniques and phonophoresis. Therefore, the aim of this study is to explore the effectiveness and safety of combining active cycle of breathing technique and phonophoresis in treating COPD patients.

Methods and analysis

We propose a single-blind randomized controlled trial using 75 hospitalized patients diagnosed with COPD with excessive sputum production. The patients will be divided into three groups. The intervention group will receive active cycle of breathing techniques combined with phonophoresis. The two comparison groups will be treated with active cycle of breathing techniques and phonophoresis, respectively. The program will be implemented daily for 1 week. The primary outcomes will be changes in sputum viscosity and production, lung function, and pulse oximetry. Secondary outcomes include the assessment of COPD and anxiety, measured by the COPD Assessment Test scale and the Anxiety Inventory for Respiratory Disease, respectively; self-satisfaction; the degree of cooperation; and the length of hospital stay. All outcome measures, with the exception of sputum production and additional secondary outcomes, will be assessed at the commencement of the study and after 1 week’s intervention. Analysis of variance will be used to investigate differences between the groups, and a p-value of less than 0.05 (two-tailed) will be considered statistically significant.

Discussion

This study introduces a combination of active cycle of breathing techniques and phonophoresis to explore the impact of these interventions on patients hospitalized with COPD. If this combined intervention is shown to be effective, it may prove to be a better treatment for patients with COPD.

Trial registration

The trial was registered prospectively on the Chinese Clinical Trial Registry on 24 December 2019.ClinicalTrials.gov ChiCTR1900028506. Registered on December 2019.

The gene NtMYC2a acts as a 'master switch' in the regulation of JA-induced nicotine accumulation in tobacco

The biosynthesis and transport of nicotine has been shown to be coordinately upregulated by jasmonate (JA). MYC2, a member of basic helix-loop-helix (bHLH) transcription factor family, is well-documented as the core player in the JA signalling pathway to regulate diverse plant development processes. Four MYC2 genes were found in the tobacco genome, NtMYC2a/2b and 1a/1b. In this study, we tested whether one of them, NtMYC2a, acts as a 'master switch' in the regulation of nicotine biosynthesis and transport in tobacco. We generated NtMYC2a knockout tobacco plants using the CRISPR-Cas9 technique and analysed the effect of NtMYC2a knockout on expression of the nicotine biosynthesis genes (NtAO, NtQS, NtPMT1a, NtQPT2, NtODC2, NtMPO1, NtA622 and NtBBLa) and transport genes (NtMATE2 and NtJAT1), as well as leaf accumulation of nicotine in the NtMYC2a knockout plants. We found that all the nicotine biosynthesis and transport genes tested in this study were significantly downregulated (>50% reduction compared with wild-type control) in the NtMYC2a knockout plants. Moreover, the leaf nicotine content in knockout plants was dramatically reduced by ca 80% compared with the wild-type control. These results clearly show that NtMYC2a acts as a 'master switch' to coordinate JA-induced nicotine accumulation in tobacco and suggests that NtMYC2a might play an important role in tobacco nicotine-mediated defence against herbivory.

CT and MRI features of giant cell tumours with prominent aneurysmal bone cysts in the extremities: a comparison with primary aneurysmal bone cysts

AIM

To test the hypothesis that computed tomography (CT) and magnetic resonance imaging (MRI) could help distinguish between giant cell tumours with prominent aneurysmal bone cysts (GABCs) and primary aneurysmal bone cysts (PABCs) of the extremities.

MATERIALS AND METHODS

CT and MRI features of 13 patients with GABCs and 13 patients with PABCs in the extremities were analysed retrospectively. The ages and sex of the patients were also recorded. Independent-samples t-tests were used for continuous variables and Fisher's exact tests were used for categorical variables to compare the differences between the two groups. Diagnostic accuracy, sensitivity, and interobserver agreement were calculated.

RESULTS

The average age of patients with GABCs (38.2±15.8 years) was higher than that of patients with PABCs (19.3±12.7 years; p=0.003). The transverse/longitudinal diameter ratio was different between GABCs (0.8±0.3) and PABCs (0.6±0.2; p=0.007). Subchondral bone involvement (92.3% versus 30.8%, p=0.004) and deep lobulation (38.5% versus 0%, p=0.039) were more likely to be noted in patients with GABCs. Surrounding blood vessels were identified in six cases of PABCs (6/13), but not in GABCs (p=0.015). The following characteristics were suggestive of GABCs, older patient age, higher transverse/longitudinal diameter ratio, subchondral bone involvement, and deep lobulation indicated a sensitivity of 84.6%, 76.9%, 75%, and 100%, and a specificity of 84.6%, 69.2%, 90%, and 61.9%, respectively. Conversely, surrounding blood vessels were suggestive of PABCs, with a sensitivity of 46.2% and specificity of 100%. The concordance between the two readers was moderate to nearly perfect.

CONCLUSION

Age, subchondral bone involvement, lobulation, transverse/longitudinal diameter ratio, and surrounding blood vessels can be used to distinguish GABCs from PABCs.

MiR-9 accelerates epithelial-mesenchymal transition of ovarian cancer cells via inhibiting e-cadherin

OBJECTIVE

To investigate the influence of micro-ribonucleic acid (miR)-9 on epithelial-mesenchymal transition (EMT) of ovarian cancer cells by targeted inhibition on E-cadherin (CDH1).

PATIENTS AND METHODS

The human ovarian cancer cells were cultured and miR-9 was repressed by inhibitors and overexpressed by miRNA mimics. The expression of EMT-related proteins was measured via Western blotting (WB). The action target of miR-9 was determined through the dual-luciferase reporter gene assay. The changes in protein levels were detected using WB.

RESULTS

The expression of miR-9 was markedly up-regulated in ovarian cancer tissues, that is, the expression level of serum miR-9 in ovarian cancer patients was higher than that in control group. After the inhibition of miR-9, the expression level of epithelial indicator CDH1 was increased, while that of interstitial indicator Vimentin was decreased. MiR-9 contained a complementary site in the 3'-untranslated region (UTR) of CDH1 messenger RNA (mRNA) and the mRNA and protein expressions of CDH1 in the cells were down-regulated obviously by miR-9 overexpression.

CONCLUSIONS

MiR-9 promotes the EMT of ovarian cancer cells through the targeted inhibition on CDH1.

Sodium butyrate relieves cerebral ischemia-reperfusion injury in mice by inhibiting JNK/STAT pathway

OBJECTIVE

The aim of this study was to investigate whether sodium butyrate (NaB) attenuated cerebral ischemia-reperfusion injury (IRI) in mice by inhibiting JNK/STAT pathway, thereby exerting a neuroprotective role.

MATERIALS AND METHODS

ICR mice were randomly assigned into five groups, including the sham group, the model group, the 1 mg/kg NaB group, the 5 mg/kg NaB group and the 10 mg/kg NaB group, respectively. IRI model was established in mice using the bilateral common carotid artery occlusion (BCCAO) method. Open-field test was performed to evaluate degree of IRI damage by recording central travel distance and central active time. The morphology of hippocampal neurons was observed by hematoxylin and eosin (HE) staining. TUNEL staining was conducted to detect apoptotic neurons in the brain of mice. Meanwhile, activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in brain tissues of mice were determined by relative commercial kits. The expression levels of inflammatory factors in brain tissues of mice were accessed using enzyme-linked immunosorbent assay (ELISA). In addition, the protein expressions of Jak2 and STAT3 in brain tissues of mice were detected by Western blot.

RESULTS

10 mg/kg NaB treatment remarkably alleviated impaired neurological defect and hippocampal neurons, as well as significantly improved neuronal survival. Mice in the 10 mg/kg NaB group showed significantly lower central travel distance and shorter central active time than those in the sham group. In addition, 10 mg/kg NaB treatment markedly increased SOD activity, whereas significantly decreased MDA activity in IRI mice. Mice in the NaB treatment group showed significantly lower levels of IL-1β, TNF-α and IL-8. Meanwhile, TUNEL-positive neurons in mice of the NaB treatment group were remarkably fewer. In addition, the protein expression levels of Jak2 and STAT3 were obviously upregulated in IRI mice, which were significantly downregulated after 10 mg/kg NaB treatment.

CONCLUSIONS

Sodium butyrate exerts neuroprotective effects on cerebral ischemia-reperfusion injury by preventing oxidative stress, inflammatory response and neuronal apoptosis through inhibiting JNK/STAT pathway.

The relationship between plasma homocysteine levels and MTHFR gene variation, age, and sex in Northeast China

Background

Hyperhomocysteinemia (HHcy) is the risk factor for cardiovascular disease and stroke. However, the impacts on the genetic variation of methylene tetrahydrofolate reductase (MTHFR) on plasma homocysteine levels in the Northeast Chinese population have not been studied. Therefore, this study was carried out to determine the relationship between HHcy and MTHFR gene variation, and whether it was influenced by age and sex of the population in Northeast China.

Materials and Methods

A total of 466 subjects were randomly enrolled in this study. According to the homocysteine levels (Hcy ≥ 15 μmol/L) of the subjects, they were divided into hyperhomocysteine (HHcy = 206) and normal homocysteine (Hcy = 260). Polymerase chain reaction/high-resolution dissolution curve and homocysteine determination kit methods were used for genotype testing and homocysteine detection, respectively.

Results

High plasma homocysteine levels are associated with MTHFR 677T and 1298A [P < 0.00, odds ratio (confidence interval) = 1.842 (1.418-2.394) >1], which is related to increasing age (P_range = 0.0005-0.0161), with the homocysteine levels of males higher than females (P < 0.0001).

Conclusion

High plasma homocysteine levels were linked to the MTHFR gene mutation. In addition, plasma homocysteine levels increased significantly with age with male's homocysteine levels higher than that of females.

Inhibition of the NF-κB signaling pathway on endothelial cell function and angiogenesis in mice with acute cerebral infarction

This study was aimed to investigate whether interferon (IFN)-induced protein 35 (IFI35) affects the signaling pathway of nuclear factor-kappa B (NF-κB) and to observe the effect of different expressions of IFI35 on the proliferation of endothelial cells and angiogenesis in rats with acute cerebral infarction. A suture method was adopted to prepare a mouse model of permanent middle cerebral artery occlusion (PMCAO). After the treatment of cerebral artery occlusion in 200 healthy male mice (weighting 20g-40g), 47 mice were selected and the double luciferase assay was used to identify different structural domains of IFI35; for the remaining 153 mice, RT-PCR and immunohistochemical assays were used to detect the mRNA expression of glioma-associated oncogene homolog 1 (Gli1), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and CD105 (endoglin). The results showed that IFI35 could reduce the level of p65 protein (REL-A) in the nucleus while affecting the production of p-p65 in the cytoplasm. At the same time, IFI35 could be used in combination with a NID1 protein domain + Nmi protein to inhibit the signaling pathway of NF-κB. Expressions of Gli1, VEGF, bFGF, and CD105 in the IFI35 treatment group were all significantly reduced (P less than0.05). In conclusion, IFI35 could suppress the activation of the NF-κB signaling pathway, reduce the proliferating potential of vascular endothelial cells, and lower the expression of vascular growth factors, thereby inhibiting angiogenesis in mice with acute cerebral infarction.

Clinical utility of quantitative dual-energy CT iodine maps and CT morphological features in distinguishing small-cell from non-small-cell lung cancer

AIM

To evaluate the clinical usefulness of quantitative dual-energy (DE) computed tomography (CT) iodine enhancement metrics combined with morphological CT features in distinguishing small-cell lung cancer (SCLC) from non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

One hundred and six untreated lung cancer patients who underwent DECT before biopsy or surgery were prospectively enrolled. Twenty-seven routine CT descriptors, including tumour location, size, shape, margin, enhancement heterogeneity, and internal and surrounding structures, and associated findings were assessed and DECT parameters were measured in all patients. Multiple logistic regression analyses were applied to identify independent predictors of SCLC. The area under the receiver operating characteristic curve was compared between CT features combined with DECT metrics and CT features alone for distinguishing SCLC from NSCLC.

RESULTS

Histology revealed NSCLC in 80 and SCLC in 26 patients. In univariate analysis, 12 morphological CT features and two DECT metrics differed significantly between NSCLC and SCLC. When DECT parameters were combined with CT features for multivariate analysis, the independent predictors of SCLC were large tumour size, central location, confluent mediastinal lymphadenopathy, homogeneous enhancement, absence of coarse spiculation, and lower iodine density and iodine ratio (all p<0.05). The area under the receiver operating characteristic curve was improved from 0.908 to 0.981 after adding DECT metrics compared with CT features alone (p=0.007).

CONCLUSION

The combination of DECT measures and CT morphological features can be used to distinguish SCLC from NSCLC, with higher diagnostic performance compared with CT morphological features alone.

Individuals with obesity but no other metabolic risk factors are not at significantly elevated all-cause mortality risk in men and women

Studies have examined mortality risk for metabolically healthy obesity, defined as zero or one metabolic risk factors but not as zero risk factors. Thus, we sought to determine the independent mortality risk associated with obesity or elevated glucose, blood pressure or lipids in isolation or clustered together. The sample included 54 089 men and women from five cohort studies (follow-up = 12.8 ± 7.2 years and 4864 [9.0%] deaths). Individuals were categorized as having obesity or elevated glucose, blood pressure or lipids alone or clustered with obesity or another metabolic factor. In our study sample, 6% of individuals presented with obesity but no other metabolic abnormalities. General obesity (hazard ratios [HR], 95% CI = 1.10, 0.8-1.6) and abdominal obesity (HR = 1.24, 0.9-1.7) in the absence of metabolic risk factors were not associated with mortality risk compared to lean individuals. Conversely, diabetes, hypertension and dyslipidaemia in isolation were significantly associated with mortality risk (HR range = 1.17-1.94, P < 0.05). However, when using traditional approaches, obesity (HR = 1.12, 1.02-1.23) is independently associated with mortality risk after statistical adjustment for the other metabolic risk factors. Similarly, metabolically healthy obesity, when defined as zero or one risk factor, is also associated with increased mortality risk (HR = 1.15, 1.01-1.32) as compared to lean healthy individuals. Obesity in the absence of metabolic abnormalities may not be associated with higher risk for all-cause mortality compared to lean healthy individuals. Conversely, elevation of even a single metabolic risk factor is associated with increased mortality risk.

MiR-18a upregulation decreases Dicer expression and confers paclitaxel resistance in triple negative breast cancer

OBJECTIVE

MiR-18a is a miRNA that is aberrantly overexpressed in triple-negative breast cancer (TNBC). However, its biophysical function in TNBC is still not clear. In this study, we investigated the association among miR-18a dysregulation, Dicer dysregulation and paclitaxel (PTX) resistance in TNBC cells.

PATIENTS AND METHODS

20 TNBC patients who received neoadjuvant chemotherapy before surgery were recruited. MiR-18a expression was quantified using QRT-PCR. The effects of miR-18a overexpression or knockdown on cell viability and apoptosis of PTX sensitive MDA-MB-231 cells and PTX resistant MDA-MB-231 cells after PTX treatment were studied. The influence of miR-18a overexpression on Dicer expression was measured by qRT-PCR and Western blot analysis.

RESULTS

Tissues from patients with stable disease (SD, n = 5) and progressive disease (PD, n = 2) to paclitaxel (PTX) containing neoadjuvant chemotherapy had significantly higher miR-18a expression than that from patients with partial response (PR, n = 13). MDA-MB-231/PTX cells had higher miR-18a expression than MDA-MB-231 cells. MiR-18a overexpression directly led to Dicer repression at mRNA and protein level. MiR-18a overexpression significantly increased PTX IC50 and reduced PTX induced cell apoptosis, while miR-18a suppression substantially decreased PTX IC50 and increased PTX induced cell apoptosis.

CONCLUSIONS

This study found that miR-18a is an important miRNA that suppresses Dicer expression and increases PTX resistance in TNBC cells.

Mating system patterns of natural populations of Pinus koraiensis along its post-glacial colonization route in northeastern China

To understand the genetic mechanisms underlying the endangerment of Pinus koraiensis, we studied the mating system of 49 families of this species in 3 natural populations along its post-glacial colonization route across ~1500 km in northeastern China using the chloroplast simple sequence repeat technique. We analyzed 11 polymorphic loci with clear and repeating bands, and we calculated the multi-locus outcrossing rate (tm), single-locus outcrossing rate, inbreeding index, and fixation index (F). Intra-population variation was not observed, but a large inter-population variation was observed in the outcrossing rate, and the tm increased from 0.767 (the south population) to 0.962 (the north population) along the post-glacial colonization route. The tm values within a population did not change with time over 2 consecutive years. The F values for the 3 populations were <0, which indicates an excess of heterozygotes. The mean effective number of alleles, Shannon diversity index, and Nei's genetic diversity index did not show a south-north pattern. The north population had the highest outcrossing rate but the lowest genetic diversity. The average genetic differentiation of P. koraiensis populations was 0.1251, which was within the average range of woody plants with outcrossing and wind pollination. This study suggests that the current endangerment of P. koraiensis is not related to its genetic structure; perhaps it is mainly caused by man-made and natural disturbances such as deforestation and fire. Therefore, reducing disturbances and enhancing habitats, rather than the genetic aspects, play more important roles in the long-term protection of P. koraiensis.

Body adiposity index and incident hypertension: the Aerobics Center Longitudinal Study

BACKGROUND AND AIM

The body adiposity index (BAI) has been recently proposed as a new method to estimate the percentage of body fat. The association between BAI and hypertension risk has not been investigated yet. The aim of our study was to evaluate the ability of BAI to predict hypertension in males and females compared with traditional body adiposity measures.

METHODS AND RESULTS

The present follow-up analysis comprised 10,309 individuals (2259 females) free of hypertension from the Aerobics Center Longitudinal Study, who completed a baseline examination between 1988 and 2003. Body adiposity measures included BAI, body mass index (BMI), waist circumference, hip circumference, percentage of body fat and waist to hip ratio (WHR). Incident hypertension was ascertained from responses to mail-back surveys between 1990 and 2004. During an average of 9.1 years of follow-up, 872 subjects (107 females) became hypertensive. Hazard ratios (HRs) and 95% confidence intervals (95% CI) showed that males in the highest categories of all body adiposity measures showed a higher incident risk of hypertension (HRs ranged from 1.37 to 2.09). Females showed a higher incident risk of hypertension only in the highest categories of BAI, BMI and WHR (HRs ranged from 1.84 to 3.36).

CONCLUSION

Our results suggest that in order to predict incident hypertension BAI could be considered as an alternative to traditional body adiposity measures.

Autophagy and chemotherapy resistance: a promising therapeutic target for cancer treatment

Induction of cell death and inhibition of cell survival are the main principles of cancer therapy. Resistance to chemotherapeutic agents is a major problem in oncology, which limits the effectiveness of anticancer drugs. A variety of factors contribute to drug resistance, including host factors, specific genetic or epigenetic alterations in the cancer cells and so on. Although various mechanisms by which cancer cells become resistant to anticancer drugs in the microenvironment have been well elucidated, how to circumvent this resistance to improve anticancer efficacy remains to be defined. Autophagy, an important homeostatic cellular recycling mechanism, is now emerging as a crucial player in response to metabolic and therapeutic stresses, which attempts to maintain/restore metabolic homeostasis through the catabolic lysis of excessive or unnecessary proteins and injured or aged organelles. Recently, several studies have shown that autophagy constitutes a potential target for cancer therapy and the induction of autophagy in response to therapeutics can be viewed as having a prodeath or a prosurvival role, which contributes to the anticancer efficacy of these drugs as well as drug resistance. Thus, understanding the novel function of autophagy may allow us to develop a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes in the treatment of cancer patients.

Synthesis and studies on the anticonvulsant activity of 5-alkoxy-[1,2,4]triazolo[4,3-a]pyridine derivatives

In this study, a series of new 5-alkoxy-[1,2,4]triazolo[4,3-a]pyridine derivatives was synthesized and their anticonvulsant activity and neurotoxicity was evaluated with the maximal electroshock and rotarod tests, respectively. The most promising compounds, 3p (5-(4-chlorophenoxy)-[1,2,4]triazolo[4,3-a]pyridine) and 3r (5-(4-bromophenoxy)-[1,2,4]triazolo[4,3-a]pyridine), showed a median effective dose of 13.2 and 15.8 mg/kg and had a protective index value of 4.8 and 6.9, respectively. For exploring the putative mechanism of action, compounds 3n, 3p and 3r were tested in chemically induced models.

Generation of pancreatic insulin-producing cells from rhesus monkey induced pluripotent stem cells

AIMS/HYPOTHESIS

The generation of induced pluripotent stem cells (iPSCs) provides a promising possibility for type 1 diabetes therapy. However, the generation of insulin-producing cells from iPSCs and evaluation of their efficacy and safety should be achieved in large animals before clinically applying iPSC-derived cells in humans. Here we try to generate insulin-producing cells from rhesus monkey (RM) iPSCs.

METHODS

Based on the knowledge of embryonic pancreatic development, we developed a four-stage protocol to generate insulin-producing cells from RM iPSCs. We established a quantitative method using flow cytometry to analyse the differentiation efficiency. In addition, to evaluate the differentiation competence and function of RM iPSC-derived cells, transplantation of stage 3 and 4 cells into immunodeficient mice was performed.

RESULTS

RM iPSCs were sequentially induced to definitive endoderm (DE), pancreatic progenitors (PP), endocrine precursors (EP) and insulin-producing cells. PDX1(+) PP cells were obtained efficiently from RM iPSCs (over 85% efficiency). The TGF-β inhibitor SB431542 promoted the generation of NGN3(+) EP cells, which can generate insulin-producing cells in vivo upon transplantation. Finally, after this four-stage differentiation in vitro, insulin-producing cells that could secrete insulin in response to glucose stimulation were obtained. When transplanted into mouse models for diabetes, these insulin-producing cells could decrease blood glucose levels in approximately 50% of the mice.

CONCLUSIONS/INTERPRETATION

We demonstrate for the first time that RM iPSCs can be differentiated into functional insulin-producing cells, which will provide the basis for investigating the efficacy and safety of autologous iPSC-derived insulin-producing cells in a rhesus monkey model for type 1 diabetes therapy.

Comparisons of leisure-time physical activity and cardiorespiratory fitness as predictors of all-cause mortality in men and women

OBJECTIVE

To examine the combined associations and relative contributions of leisure-time physical activity (PA) and cardiorespiratory fitness (CRF) with all-cause mortality.

DESIGN

Prospective cohort study. Setting Aerobics centre longitudinal study.

PARTICIPANTS

31,818 men and 10 555 women who received a medical examination during 1978-2002. Assessment of risk factors Leisure-time PA assessed by self-reported questionnaire; CRF assessed by maximal treadmill test. Main outcome measures All-cause mortality until 31 December 2003.

RESULTS

There were 1492 (469 per 10,000) and 230 (218 per 10,000) deaths in men and women, respectively. PA and CRF were positively correlated in men (r = 0.49) and women (r = 0.47) controlling for age (p < 0.001 for both). PA was inversely associated with mortality in multivariable Cox regression analysis among men, but the association was eliminated after further adjustment for CRF. No significant association of PA with mortality was observed in women. CRF was inversely associated with mortality in men and women, and the associations remained significant after further adjustment for PA. In the PA and CRF combined analysis, compared with the reference group "not meeting the recommended PA (< 500 metabolic equivalent-minute/week) and unfit", the relative risks (95% CIs) of mortality were 0.62 (0.54 to 0.72) and 0.61 (0.44 to 0.86) in men and women "not meeting the recommended PA and fit", 0.96 (0.61 to 1.53) and 0.93 (0.33 to 2.58) in men and women "meeting the recommended PA and unfit" and 0.60 (0.51 to 0.70) and 0.56 (0.37 to 0.85) in men and women "meeting the recommended PA and fit", respectively.

CONCLUSIONS

CRF was more strongly associated with all-cause mortality than PA; therefore, improving CRF should be encouraged in unfit individuals to reduce risk of mortality and considered in the development of future PA guidelines.

Immunophenotype of myeloid granulocytes: a pilot study for distinguishing myelodysplastic syndrome and aplastic anemia by flow cytometry

It is often difficult to distinguish myelodysplastic syndrome (MDS) from aplastic anemia (AA) because of the considerable clinical, cytologic histologic similarities between these two disorders; however, distinguishing between AA and MDS is of great importance because there is a higher risk of progression to acute leukemia in patients with MDS compared with AA. Up to now, CD34(+) cells in MDS and AA patients have been studied extensively; however, little information is available on myeloid granulocytes. The aim of this study was to determine whether immunophenotype of myeloid granulocytes in AA patients was different from that of MDS. Flow cytometry was used to assess the immunophenotype of myeloid granulocytes in 22 patients with MDS, 12 with AA, and 10 normal subjects. Our data showed that the percentages of CD13(+) granulocytes, CD33(+) granulocytes, CD34(+) granulocytes, and HLA-DR(+) granulocytes were significantly higher in patients with MDS than in AA patients and normal subjects (P < 0.05). The percentages of CD15(+) granulocytes and CD10(+) granulocytes were significantly lower in patients with MDS than in AA patients and normal subjects (P < 0.05). There were no significant differences in the expression of these markers between patients with AA and normal subjects (P > 0.05). As refractory anemia progressing to refractory anemia with excess blasts, the percentages of CD13(+) granulocytes, CD33(+) granulocytes, CD34(+) granulocytes and HLA-DR(+) granulocytes were significantly increased, whereas, the percentage of CD15(+) granulocytes was significantly decreased (P < 0.05). These data suggest that immunophenotype of myeloid granulocytes may be a useful parameter for the differential diagnosis of MDS and AA.

The association of cardiorespiratory fitness and physical activity with incidence of hypertension in men

BACKGROUND

Few prospective studies have simultaneously investigated the relationship between physical activity, cardiorespiratory fitness (CRF), and the development of hypertension in initially normotensive individuals. In the Aerobics Center Longitudinal Study (ACLS), we examined this association among initially healthy normotensive men.

METHODS

Participants were 16,601 men aged 20-82 years who completed a baseline examination during 1970-2002 and were followed for hypertension incidence. Physical activity was self-reported and CRF was quantified from the duration of a maximal treadmill test.

RESULTS

A total of 2,346 men reported hypertension during a mean 18 years of follow-up. Event rates per 10,000 man-years adjusted for age and examination year were 86.2, 76.6, and 66.7 across physical activity groups of sedentary, walker/jogger/runner (WJR), and sport/fitness, respectively, and 89.8, 78.4, and 64.6 for low, middle, and high CRF, respectively (trend P < 0.0001). These associations persisted after further adjustment for body mass index (BMI), smoking, alcohol intake, resting systolic blood pressure, baseline health status, family history of diseases, and survey response patterns.

CONCLUSION

Both physical activity and CRF are associated with lower risk of developing hypertension in a graded fashion. These findings provide a basis for health professionals to emphasize the importance of participating in regular physical activity to improve fitness for the primary prevention of hypertension in men.

Body mass index as a predictor of hypertension incidence among initially healthy normotensive women

BACKGROUND

Few prospective studies have evaluated the risk for incident hypertension (HTN) across the normal range of body mass index (BMI). Even fewer studies included body composition and fat distribution measurements in their analyses. In the Aerobics Center Longitudinal Study, we examined HTN risk in women across a wide spectrum of baseline BMI (kg/m(2)) values and also studied waist circumference (WC, cm), percent body fat, fat mass (FM, kg), and fat-free mass (FFM, kg) on incident HTN in subgroup analyses.

METHODS

A total of 5,296 healthy normotensive women between 20 and 77 years of age completed a baseline examination during 1971-2004, and were followed for HTN incidence. Incident HTN was identified using mail-back surveys.

RESULTS

A total of 592 women reported HTN during a mean 16.7 years of follow-up. Higher BMI, even within the "normal" range, was associated with greater risk of HTN. Compared with women in the lowest fifth of BMI (18.5-20.0 kg/m(2)), the hazard ratios (HRs) (95% confidence interval (CI)) of developing HTN for women with a BMI of 20.1-21.2, 21.3-22.5, 22.6-24.7, and >24.7 were 1.19 (0.89-1.60), 1.33 (0.99-1.78), 1.36 (1.03-1.81), and 2.01 (1.52-2.66), respectively (P(trend) < 0.001). In a subgroup (n = 3,189) with complete data on all the five adiposity measures, significant positive associations with HTN were seen across incremental fifths of BMI, percent body fat, and FM (P(trend) < 0.05 each), but not WC and FFM.

CONCLUSIONS

Clinicians should emphasize the importance of weight management for the primary prevention of HTN in women.

Androgen regulation of the cell-cell adhesion molecule-1 (Ceacam1) gene

Previous studies have established that the cell-cell adhesion molecule-1 (CEACAM1, previously known as C-CAM1) functions as a tumor suppressor in prostate cancer and is involved in the regulation of prostate growth and differentiation. However, the molecular mechanism that modulates CEACAM1 expression in the prostate is not well defined. Since the growth of prostate epithelial cells is androgen-regulated, we investigated the effects of androgen and the androgen receptor (AR) on CEACAM1 expression. Transient transfection experiments showed that the AR can enhance the Ceacam1 promoter activity in a ligand-dependent manner and that the regulatory element resides within a relatively short (-249 to -194 bp) segment of the 5'-flanking region of the Ceacam1 gene. This androgen regulation is likely through direct AR-promoter binding because a mutant AR defective in DNA binding failed to upregulate reporter gene expression. Furthermore, electrophoretic mobility shift assays demonstrated that the AR specifically binds to this sequence, and mutation analysis of the potential ARE sequences revealed a region within the sequence that was required for the AR to activate the Ceacam1 gene. Therefore, the regulation of Ceacam1 gene expression by androgen may be one of the mechanisms by which androgen regulates prostatic function.

Repression of androgen-regulated gene expression by dominant negative androgen receptors

The androgen receptor (AR) is a ligand-dependent transcription activator responsible for male sexual development. In order to specifically inhibit the AR pathway, dominant negative ARs were constructed by inactivation of the major transactivation domains of the wild type AR and fusing this mutant (AR122) to the Krüppel-associated box (KRAB) repressor domain and/or histone deacetylase (HDAC1). The HDAC1-KRAB-AR122 protein was the most successful dominant negative AR, capable of repressing the wild type AR ninefold when co-expressed at a 1:1 plasmid ratio. A maximal repression of 41-fold was achieved when HDAC1-KRAB-AR122 was cotransfected with the wild type AR at a 4:1 plasmid ratio. HDAC1-KRAB-AR122 repressed transcription in a ligand-dependent manner since it inhibited a constitutively active AR mutant (AR5) only in the presence of agonists. High concentrations of partial agonists such as RU486, cyproterone acetate, and estradiol were also capable of triggering repression by HDAC1-KRAB-AR122. The potent dominant negative AR proteins might prove useful tools to inhibit AR function in vitro and in vivo.

[Super heavy oil produced water treatment by surface flow constructed wetland]

This paper adopts a new economic technology of treating super heavy oil produced water using surface flow reed wetland system. The field test was conducted at the average filtration rate of 3.33 cm/d. The average influent concentrations per year of COD, Oil, BOD5, TN were 459.16 mg/L, 27.65 mg/L, 33.52 mg/L, 13.74 mg/L, and the average effluent concentrations per year of above indices were 77.21 mg/L, 1.42 mg/L, 3.90 mg/L, 1.60 mg/L, respectively. Its respective removal ratios of COD, Oil, BOD5, TN and pH were 83.18%, 94.86%, 88.37%, 88.36%, 7.87-7.77. Analyses showed that super heavy oil produced water had no obvious effect on soil and almost no effect on growth volume and quality of reeds. Results indicated that the surface flow reed wetland could provide an efficient economical, stable new means of treating super heavy oil produced water.

Monocyte adhesion to balloon-injured arteries: the influence of endothelial cell seeding

OBJECTIVE

Deendothelialization of injuries of the artery disrupts normal vascular homeostasis, affecting both the structural integrity of the blood vessel wall, as well as the interaction of the arterial surface with blood components such as platelets, leukocytes, and circulating proteins. Leukocyte and, in particular, monocyte recruitment to damaged vessels has been implicated in the pathogenesis of intimal hyperplasia. We hypothesize that reendothelialization is an important modulator of monocyte adhesion to healing arterial surfaces.

METHODS

New Zealand white rabbits (n = 20) were subjected to bilateral iliofemoral artery balloon injury. Cultured, autologous venous endothelial cells (ECs) were immediately seeded onto one vessel, whereas the contralateral artery received medium alone, to accelerate endothelial relining. Vessels were harvested (5-9 days after injury) for analysis of permeability (Evans Blue dye exclusion), endothelial coverage (anti-CD31 immunohistochemistry), monocyte adhesion (ex vivo binding of 51Na2CrO4-labeled monocytic THP-1 cells), and monocyte recruitment (RAM-11 immunohistochemistry).

RESULTS

Improved EC coverage was evidenced by positive staining for CD31 in the seeded vessels. Vessel wall permeability was markedly reduced in EC-seeded arteries (29% +/- 10% vs 99% +/- 0% surface Evans blue staining, P <.005), consistent with restoration of a functional endothelial barrier. EC seeding significantly reduced ex vivo THP-1 binding to vessels explanted at a mean of 8 days after injury (45,170 +/- 8939 vs 85,994 +/- 16,500 cells/cm2, P <.05). However, RAM-11 staining revealed no significant difference in overall macrophage accumulation between seeded and control vessels 1 week after injury (111 +/- 22 vs 95 +/- 14 cells/section, P =.36).

CONCLUSIONS

Immediate seeding of a balloon-injured rabbit artery with cultured ECs results in accelerated restoration of the endothelial lining. At 1 week, barrier function is improved, and the seeded vessel surface is less adhesive to activated monocytes ex vivo, as compared with injured controls. Nonetheless, EC-seeded and nonseeded arteries demonstrate similar total macrophage accumulation over 1 week. These data suggest that after mechanical arterial injury, endothelial coverage may be one important variable influencing leukocyte adhesion.

Stem cell factor and erythropoietin inhibit apoptosis of human erythroid progenitor cells through different signalling pathways

Erythropoietin (EPO) and stem cell factor (SCF) are two important factors in human erythropoiesis. We have recently demonstrated that SCF and EPO synergistically activate mitogen-activated protein (MAP) kinase, thereby promoting growth of human erythroid colony-forming cells (ECFCs). In the present study, we have examined the intracellular mechanisms by which SCF and EPO maintain survival of these cells. In the absence of SCF and EPO, human ECFCs underwent rapid apoptosis. The process was significantly inhibited by addition of a single factor and was totally prevented in the presence of both factors. Treatment of ECFCs with wortmannin, a specific inhibitor of phosphoinositide 3-kinase (PI3K), inhibited the antiapoptotic effect of SCF but had no effect on that of EPO, indicating that SCF but not EPO inhibits apoptosis through the PI3K pathway. In contrast, treatment of ECFCs with PD98059, a specific inhibitor of MAP kinase/ERK kinase (MEK), inhibited cell growth but had no effect on the antiapoptotic activity of either SCF or EPO, suggesting that SCF and EPO prevent apoptosis of human ECFCs independent of the extracellular signal-regulated kinase (ERK) pathway. Interestingly, both EPO and SCF induced activation of PI3K. However, through PI3K, SCF caused activation of protein kinase B (PKB), an anti-apoptosis signal, whereas EPO led to activation of ERKs. Furthermore, the SCF- and EPO-maintained expression of antiapoptotic protein Bcl-XL was correlated with the activation of ERKs and was inhibited by PD98059, suggesting that Bcl-XL may not have a major role in preventing apoptosis of human ECFCs. Phosphorylated BAD was not affected by SCF, EPO or wortmannin. Taken together with our previous results, the present study indicates that SCF and EPO support survival and growth of human ECFCs through different signalling pathways and that they transduce distinctly different signals through activation of PI3K.

Gene delivery to in situ veins: differential effects of adenovirus and adeno-associated viral vectors

PURPOSE

Gene transfer offers the potential to modify vein graft biology at the time of surgical implantation. Efficiency of gene delivery, stability of expression, and host responses are critical parameters for candidate vectors. We compared the effects of intraluminal exposure with adenovirus (AD) and adeno-associated virus (AAV) vectors on transgene expression and monocyte adhesion (MA) in treated vein segments.

METHODS

Adult New Zealand white rabbits (N = 51) were anesthetized, and the jugular veins were cannulated bilaterally. Veins were gently distended with either vector (2.10(8) to 1.10(10) infective particles/mL) or vehicle (control) for 30 minutes, after which venous flow was restored. AD and AAV vectors encoding for the marker genes beta-galactosidase (LacZ) and green fluorescent protein (GFP) were used. Vessels were explanted 2 to 40 days postinfection for analysis of gene expression (X-gal staining, reverse transcriptase-polymerase chain reaction), MA, and immunohistochemistry. Ex vivo adhesion assays used (51)Cr-labeled THP-1 cells. Statistical significance was tested by using analysis of variance with a P value less than.05.

RESULTS

All animals survived, and all treated veins were patent at sacrifice. Intraluminal exposure to AD at a titer of 1.10(9) resulted in near complete transduction of the endothelium at 2 days, with no detectable expression by day 14. At an equal titer of infectious particles, transgene expression was markedly less for AAV at 2 to 7 days, but improved at 2 weeks and persisted to 40 days. MA was significantly increased 2 days after AD exposure (2.7-fold vs control, *P <.002); AAV treatment had no discernible effect on MA.

CONCLUSION

AD-mediated gene transfer to vein segments resulted in robust, transient gene expression that disappeared after 2 weeks. In comparison, AAV-mediated gene delivery was less efficient, but resulted in delayed onset, persistent expression beyond 30 days. AD exposure induced an early increase in MA to the vein surface that was not seen with AAV treatment. Current generations of both AD and AAV vectors have significant, albeit different, limitations for vascular gene therapy.

Tyrosine phosphorylation of myelin P(0) and its implication in signal transduction

P(0), a major structural protein of peripheral myelin, belongs to the immunoglobulin superfamily. Sequence comparison of P(0) with PZR, a tyrosine phosphatase SHP-2 binding protein we recently cloned, revealed the presence of an immunoreceptor tyrosine-based inhibitory motif (ITIM) in the intracellular portion of the P(0) molecule. To study the role of this putative ITIM in signal transduction, we have expressed P(0) in HT-1080 and 293 cells. Stimulation of the transfected cells with pervanadate, a powerful inhibitor of tyrosine phosphatases, resulted in tyrosine phosphorylation of P(0) and its association with several tyrosine-phosphorylated proteins. Mutation of Y(220) embedded in the ITIM to phenylalanine abolished the tyrosine phosphorylation and the association. Tyrosine phosphorylation of P(0) and its association with other signaling proteins were also observed in pervanadate-treated RN22 Schwannoma cells, which express endogenous P(0). Furthermore, injection of pervanadate induced tyrosine phosphorylation of P(0) in peripheral nerves of newborn but not adult mice. The physiological importance of the ITIM in P(0) is implied by the fact that a naturally occurred P(0) mutant with a disrupted ITIM has a dominant role in causing Dejerine-Scotts syndrome. Taken together, P(0) is phosphorylated on Try(220). The presence of an ITIM in P(0) and its ability to mediate protein-protein interaction through tyrosine phosphorylation indicate that P(0) is not merely a structural protein but may also be a crucial player in cell signaling.

An analysis for death causes in 45 cases of liver cancer treated with traditional Chinese drugs

Among the 165 cases of late-stage liver cancer treated in our hospital, 65 (39.4%) died, with an average survival time of 8.1 months and a median survival time of 7 months. Among the 65 dead patients, 45 were treated with traditional Chinese drugs and 20 with western medicine. The average survival time was 8.4 months in the former and 7.3 months in the latter group. The direct causes of death for the 65 patients were hepatic coma, severe hemorrhage of the upper digestive tract, Heyd's syndrome, hepatorrhexis, respiratory failure, cardiac failure, etc. The incidence rates of hemorrhage of the upper digestive tract and hepatorrhexis in the 45 patients treated with traditional Chinese drugs were obviously lower than those treated with western medicine.

Soluble interleukin-6 (IL-6) receptor with IL-6 stimulates megakaryopoiesis from human CD34(+) cells through glycoprotein (gp)130 signaling

We have recently shown that stimulation of glycoprotein (gp) 130, the membrane-anchored signal transducing receptor component of IL-6, by a complex of human soluble interleukin-6 receptor (sIL-6R) and IL-6 (sIL-6R/IL-6), potently stimulates the ex vivo expansion as well as erythropoiesis of human stem/progenitor cells in the presence of stem cell factor (SCF). Here we show that sIL-6R dose-dependently enhanced the generation of megakaryocytes (Mks) (IIbIIIa-positive cells) from human CD34(+) cells in serum-free suspension culture supplemented with IL-6 and SCF. The sIL-6R/IL-6 complex also synergistically acted with IL-3 and thrombopoietin (TPO) on the generation of Mks from CD34(+) cells, whereas the synergy of IL-6 alone with TPO was barely detectable. Accordingly, the addition of sIL-6R to the combination of SCF + IL-6 also supported a substantial number of Mk colonies from CD34(+) cells in serum-free methylcellulose culture, whereas SCF + IL-6 in the absence of sIL-6R rarely induced Mk colonies. The addition of monoclonal antibodies against gp130 to the suspension and clonal cultures completely abrogated the megakaryopoiesis induced by sIL-6R/IL-6 in the presence of SCF, whereas an anti-TPO antibody did not, indicating that the observed megakaryopoiesis by sIL-6R/IL-6 is a response to gp130 signaling and independent of TPO. Furthermore, human CD34(+) cells were subfractionated into two populations of IL-6R-negative (CD34(+) IL-6R-) and IL-6R-positive (CD34(+) IL-6R+) cells by fluorescence-activated cell sorting. The CD34(+) IL-6R- cells produced a number of Mks as well as Mk colonies in cultures supplemented with sIL-6R/IL-6 or TPO in the presence of SCF. In contrast, CD34(+) IL-6R+ cells generated much less Mks and lacked Mk colony forming activity under the same conditions. Collectively, the present results indicate that most of the human Mk progenitors do not express IL-6R, and that sIL-6R confers the responsiveness of human Mk progenitors to IL-6. Together with the presence of functional sIL-6R in human serum and relative unresponsiveness of human Mk progenitors to IL-6 in vitro, current results suggest that the role of IL-6 may be mainly mediated by sIL-6R, and that the gp130 signaling initiated by the sIL-6R/ IL-6 complex is involved in human megakaryopoiesis in vivo.

Specific androgen receptor activation by an artificial coactivator

Transcription activation of steroid receptors, such as the androgen receptor (AR), is mediated by coactivators, which bridge the receptor to the preinitiation complex. To develop a tool for studying the role of the AR in normal development and disease, we constructed artificial coactivators consisting of the transcription activation domains of VP16 or p65/RelA and the AR hinge and ligand-binding domain (ARLBD), which has been shown to interact with the AR N-terminal domain. The artificial VP16-ARLBD and ARLBD-p65 coactivators interacted with the AR N terminus and wild-type AR in an androgen-dependent and androgen-specific manner. VP16-ARLBD and ARLBD-p65 enhanced the AR transactivity up to 4- and 13-fold, respectively, without affecting the expression of the AR protein. The coactivators did not enhance the transcription activity of the progesterone receptor (PR) or the glucocorticoid receptor (GR), showing their specificity for the AR. In addition, to construct PR- and GR-specific coactivators, the VP16 activation domain was fused to the PR and GR hinge/ligand-binding domain. Although VP16-PRLBD and VP16-GRLBD interacted with the C-terminal portion of steroid receptor coactivator-1, they did not enhance the transcription activity of their receptor. The presented strategy of directing activation domains or other protein activities into the DNA-bound AR complex provides a novel means of manipulating AR function in vitro and in vivo.

[Expression of bcl-2 gene in the evolution of chronic myelogenous leukemia to blast crisis and its implication]

OBJECTIVE

To investigate the expression of bcl-2 gene and cell apoptosis and cell cycle in bone marrow of chronic myelogenous leukemia (CML).

METHODS

APAAP assay and in situ hybridization were used for the expression of BCL-2 protein and bcl-2 mRNA in fresh bone marrow samples from 60 cases of CML. Flow cytometry was used to assess the extent of apoptosis and cell cycle percentage.

RESULTS

The expression of bcl-2 gene had no statistical difference between CMLs at presentation and in chronic phase, but was much lower in blast crisis (P < 0.05). The percentage of bcl-2 mRNA positive cells was consistent with BCL-2 protein expression. In addition, BCL-2 protein was related to the Hb levels, BPC, and immature cells in the peripheral blood and bone marrow. Notably, the extent of apoptosis in accelerated phase/blast crisis was much lower than that in chronic phase(P = 0.028), while the cell cycle had no difference.

CONCLUSION

High level of bcl-2 gene expression and low extent of apoptosis in bone marrow cells of CML might partially be the mechanism of poor prognosis of blast crisis, and this provides a new experimental basis for early diagnosis and treatment of CML blast crisis.

[Isolation and identification of Agrobacterium spp. from cherry crown galls and their sensitivities to agrocin 84]

Crown galls were sampled from cherry yards of Shandong, Hebei, and Liaoning provinces. 46 pathogenic strains were isolated. Physiological and biochemical tests revealed that 4 strains were Agrobacterium tumefaciens(bio. 1) and that the other 42 strains were A. rhizogenes (bio. 2), according to the classifications and nomenclatures of the genus Agrobacterium and the species revised by Sawada et al and Bouzar. The Ti plasmids of all strains were nopaline type. All strains were sensitive to agrocin 84, which suggested that crown gall disease of cherry could be controlled by K84 strain.

Synergistic activation of MAP kinase (ERK1/2) by erythropoietin and stem cell factor is essential for expanded erythropoiesis

Stem cell factor (SCF) and erythropoietin (EPO) work synergistically to support erythropoiesis, but the mechanism for this synergism is unknown. By using purified human erythroid colony-forming cells (ECFC), we have found that SCF and EPO synergistically activate MAP kinase (MAPK, ERK1/2), which correlates with the cell growth and thus may be responsible for the synergistic effects. Treatment of the cells with PD98059 and wortmannin, inhibitors of MEK and PI-3 kinase, respectively, inhibited the synergistic activation of MAPK and also the cell growth, further supporting this conclusion. Wortmannin only inhibits MAPK activation induced by EPO but not that by SCF, suggesting that SCF and EPO may activate MAPK through different pathways, which would facilitate synergy. Furthermore, EPO, but not SCF, led to activation of STAT5, whereas SCF and wortmannin had no effect on the EPO-induced STAT5 activation, suggesting that STAT5 is not involved in the synergistic action of SCF and EPO. Together, the data suggest that synergistic activation of MAPK by SCF and EPO is essential for expanded erythropoiesis.