The association between RhEPO and FN expression in glomerular mesangial cells

AIM

Erythropoietin (rhEPO) is increasingly being used in the treatment of anemia caused by miscellaneous reasons. The aim of our research is to investigate the effects of recombinant human erythropoietin (rhEPO) on cellular growth and fibronectin (FN) expression in glomerular mesangial cells.

METHODS

Western blot was used to detect the expression of FN induced by rhEPO (1, 10, 100 and 1000U/mL). In vivo studies, male CD-1 mice were administered rhEPO subcutaneously at a single dose of 1000U/Kg. The cellular hypertrophy was quantified by counting cell number and calculating the ratio of cell protein to cell number.

RESULTS

1) Compared with the control group, the results of mesangial cells' growth stimulated by rhEPO were not significantly different; 2) RhEPO lead to hypertrophy of mesangial cells; 3) rhEPO induced FN expression of mesangial cell in a dose-dependent way. Compared to control, 100U/mL rhEPO enhanced the expression of FN significantly; 4) indirect immunofluorescence showed that rhEPO induced large amount deposition of FN in the intercellular space of mesangial cells; 5) in vivo studies, there were markedly increase of FN expression in mice received the injection of rhEPO.

CONCLUSION

RhEPO could up-regulated the expression of FN and induced glomerular mesangial cells hypertrophy. These results suggested rhEPO could induce dysfunction of renal glomerulus through its influence on the function of mesangial cells.

Management of treatment-emergent peripheral neuropathy in multiple myeloma

Peripheral neuropathy (PN) is one of the most important complications of multiple myeloma (MM) treatment. PN can be caused by MM itself, either by the effects of the monoclonal protein or in the form of radiculopathy from direct compression, and particularly by certain therapies, including bortezomib, thalidomide, vinca alkaloids and cisplatin. Clinical evaluation has shown that up to 20% of MM patients have PN at diagnosis and as many as 75% may experience treatment-emergent PN during therapy. The incidence, symptoms, reversibility, predisposing factors and etiology of treatment-emergent PN vary among MM therapies, with PN incidence also affected by the dose, schedule and combinations of potentially neurotoxic agents. Effective management of treatment-emergent PN is critical to minimize the incidence and severity of this complication, while maintaining therapeutic efficacy. Herein, the state of knowledge regarding treatment-emergent PN in MM patients and current management practices are outlined, and recommendations regarding optimal strategies for PN management during MM treatment are provided. These strategies include early and regular monitoring with neurological evaluation, with dose modification and treatment discontinuation as indicated. Areas requiring further research include the development of MM-specific, patient-focused assessment tools, pharmacogenomic analysis of patient DNA, and trials to assess the efficacy of pharmacological interventions.

The biological function of the WD40 repeat-containing protein p55/Caf1 in Drosophila

BACKGROUND

The p55 family WD40 repeat-containing histone chaperone proteins are components of several chromatin regulatory complexes (such as PRC2, NURF and CAF-1) and interact with histone H4, yet their functional relevance in vivo is unclear.

RESULTS

Here we use Drosophila as a genetic model to dissect the function of p55/Caf1 during development. In agree with a recent report, we find that p55 is essential for Drosophila development and is required for cell proliferation and viability. However, our data further demonstrate that histone H3K27 di-/tri-methylation and PRC2-mediated gene silencing still occur normally when p55 is missing. p55 is also implicated in bridging chromatin regulatory complexes to the chromatin by binding to histone H4, but we find that a transgene of p55 whose binding pocket is disrupted could still functionally substitute the wild-type p55 for the survival.

CONCLUSIONS

Our studies suggest that p55 is not crucial for PRC2-mediated gene silencing in vivo, and the vital function of p55 is probably not dependent on its interaction with histone H4.

Genetic alterations in pulmonary epithelioid hemangioendothelioma and epithelioid angiosarcoma

Epithelioid hemangioendothelioma (EHE) is a low-to-intermediate-grade vascular tumor that occurs in many organs, and epithelioid angiosarcoma (EA) is a subtype of angiosarcoma that is associated with high-grade malignancy. These two types of tumors have different forms of biological behavior. Pulmonary epithelioid hemangioendothelioma (PEH) and epithelioid angiosarcoma (PEA) are both very rare, and genetic studies on them are extremely limited. We examined and compared the cytogenetic characteristics of these two types of lung tumors in two patients utilizing the Array-Comparative Genomic Hybridization (Array-CGH) method. Considerable differences in the cytogenetic characteristics were observed between the two types of tumors. Small fragment gains (<10 MB) were dominant in PEH, whereas large fragment gains and deletions (>10 MB) were dominant in PEA. Some large fragment alterations, such as gains in chromosomes 19q and 19p, and deletions in chromosomes 9p and 13q, involved over half of a chromosome arm. PEH and PEA showed great cytogenetic differences; therefore, further genetic studies on these two types of tumors are warranted.

Pronounced slow β-relaxation in La-based bulk metallic glasses

Most metallic glasses (MGs) exhibit weak evidence of slow β-relaxation in their dynamic mechanical spectroscopy spectra. In contrast to other MGs, the La-based MGs we report here show a distinct slow β-relaxation peak in the mechanical relaxation measurements. We find that the slow β-relaxation behavior can be tuned by modification of the chemical composition and fragility. The structural origin of the slow β-relaxation and correlation between β-relaxation and α-relaxation in the MGs are also discussed. MGs with pronounced slow β-relaxation and tunable properties might provide a model system to investigate some long-standing issues in the glass field.

Uncertainty and sensitivity analysis for anisotropic inhomogeneous head tissue conductivity in human head modelling

The accuracy of an electroencephalography (EEG) forward problem partially depends on the head tissue conductivities. These conductivities are anisotropic and inhomogeneous in nature. This paper investigates the effects of conductivity uncertainty and analyses its sensitivity on an EEG forward problem for a spherical and a realistic head models. We estimate the uncertain conductivities using an efficient constraint based on an optimization method and perturb it by means of the volume and directional constraints. Assigning the uncertain conductivities, we construct spherical and realistic head models by means of a stochastic finite element method for fixed dipolar sources. We also compute EEG based on the constructed head models. We use a probabilistic sensitivity analysis method to determine the sensitivity indexes. These indexes characterize the conductivities with the most or the least effects on the computed outputs. These results demonstrate that conductivity uncertainty has significant effects on EEG. These results also show that the uncertain conductivities of the scalp, the radial direction of the skull and transversal direction in the white matter are more sensible.

Superficial primary small cell carcinoma of the esophagus: clinicopathological and immunohistochemical analysis of 15 cases

Primary esophageal small cell carcinoma (PESCC) is a relatively rare and aggressive tumor with poor prognosis. Systemic spreading and metastasis often occur at diagnosis. Although 5-year survival rate of superficial squamous cell carcinoma of the esophagus can be 86.1%, 5-year survival rate of superficial PESCC is still relatively low. This study mainly retrospectively analyzed clinicopathological and immunohistochemical features of 15 cases of superficial PESCC in our hospital from 1990 to 2004, in order to find suitable diagnostic markers and applicable therapies for this disease. The records mainly included presenting symptoms, demographics, diagnostic method, histopathology, follow-up, and therapy. Immunohistochemical staining of chromogranin A (CgA), neuron-specific enolase (NSE), synaptophysin (Syn), neuronal cell adhesion molecules (CD56), thyroid transcription factor-1 (TTF-1), cytokeration 34betaE12 (CK34betaE12), cytokeratin (AE1/AE3), and cytokeratin 10/13 was performed. Incidence of superficial PESCC accounted for 4.8% of that of superficial carcinoma of the esophagus during the same period. Initial symptoms of all patients were dysphagia or accompanied with retrosternal pain and upper abdominal pain, and duration of these symptoms was 75 days averagely. Mean age of patients was 58.8 years old, and the male-to-female ratio was 2.75 : 1. Lesions were mainly located at middle thoracic esophagus. One, 2, and 5-year survival rates were 66.7, 33.3, and 6.7%, respectively. The median survival time was 19 months and mean survival time was 23.7 months after diagnosis. The percentages of PESCC samples with positive immunoreactivity were NSE 100%, Syn 100%, AE1/AE3 100%, CD56 93.3%, TTF-1 60%, CgA 53.3%, CK34betaE12 6.7%, and cytokeratin 10/13 0%, respectively. Our study suggested that PESCC was a rare and aggressive tumor with high malignancy. Superficial PESCC had rapid progression and poor prognosis compared with superficial squamous cell carcinoma of the esophagus at the same stage. The systemic therapy based on combination of postoperative chemotherapy and radiotherapy might be an effective approach for the treatment of superficial PESCC as a systemic disease. Higher proportion of positive labeling of NSE, Syn, AE1/AE3, CD56, TTF-1, and CgA in PESCC was valuably applied in diagnosis and differential diagnosis.

Identification of tumor stem-like cells in a mouse myeloma cell line

We used colony formation assay in the soft agar media or the serum-free media, the methods of identifying BrdU-label-retaining cells and the SP cells as well as the tumorigenicity test in BALB/c mice, respectively, to analyze tumor stem like cells in the SP2/0 cell line. The results showed that a few SP2/0 cells were capable of forming colonies in the soft agar media, contained BrdU-label-immortal strand in the SP2/0 cell line. The SP2/0 cells in the serum-free media gained higher tumorigenicity in the BALB/c mice than the SP2/0 cells cultivated in the complete media did. Overall, only a few of the SP2/0 cells were found to possess the characteristics of tumor stem-like cells, such as high proliferative potency, more self-renewal and stronger tumorigenesis, or greater similarity to the tumor stem cells (TSCs) traits. The biology of tumor stem-like cells contributes to the identification of molecular targets important for future tumor therapy.