Rac1-PAK2 pathway is essential for zebrafish heart regeneration

P-21 activated kinases, or PAKs, are serine-threonine kinases that play important roles in diverse heart functions include heart development, cardiovascular development and function in a range of models; however, the mechanisms by which PAKs mediate heart regeneration are unknown. Here, we demonstrate that PAK2 and PAK4 expression is induced in cardiomyocytes and vessels, respectively, following zebrafish heart injury. Inhibition of PAK2 and PAK4 using a specific small molecule inhibitor impedes cardiomyocyte proliferation/dedifferentiation and cardiovascular regeneration, respectively. Cdc42 is specifically expressed in the ventricle and may function upstream of PAK2 but not PAK4 under normal conditions and that cardiomyocyte proliferentation during heart regeneration relies on Rac1-mediated activation of Pak2. Our results indicate that PAKs play a key role in heart regeneration.

Ultrastructural and Cytochemical Properties of Peripheral Blood Cells of Piebald Naked Carp (Gymnocypris eckloni)

The ultrastructural and cytochemical properties of peripheral blood cells of Gymnocypris eckloni were investigated by transmission electron microscopy and a range of cytochemical techniques to provide clear insight into the structure and function of blood cells from this fish. Ultrastructurally, erythrocytes, leucocytes (neutrophils, eosinophils, lymphocytes, monocytes), thrombocytes and plasma cells were identified in the peripheral blood of G. eckloni. The most special ultrastructural characteristics of blood cells in this fish were that neutrophils exhibited only one type of cytoplasmic granules containing an eccentric, spherical or oval electron-dense core, and eosinophils presented two types of granules with non-uniform electronic density and without crystalloids in their cytoplasm. Neutrophils, eosinophils, lymphocytes, monocytes and thrombocytes were positive for periodic acid-Schiff and α-naphthyl acetate esterase staining. Intense peroxidase positive staining was observed in neutrophils and monocytes, but not in eosinophils, lymphocytes and thrombocytes. Neutrophils, eosinophils and monocytes were stained positively for acid phosphatase, whereas lymphocytes and thrombocytes did not stain. Leucocytes and thrombocytes were negative for alkaline phosphatase and Sudan black B staining. Erythrocytes were negative for all cytochemical staining. The cytochemical and ultrastructural features of peripheral blood cells of G. eckloni were similar to those of other fish species. However, some important differences were identified in G. eckloni.

The Fusarium toxin zearalenone and deoxynivalenol affect murine splenic antioxidant functions, interferon levels, and T-cell subsets

This study aimed to evaluate the effects of the Fusarium toxin zearalenone (ZEA) and deoxynivalenol (DON) on splenic antioxidant functions, IFN levels, and T-cell subsets in mice. Herein, 360 mice were assigned to nine groups for a 12-day study. Mice were administered an intraperitoneal injection for 4 consecutive days with different concentrations of ZEA alone, DON alone, or ZEA+DON. Spleen and blood samples were collected on days 0, 3, 5, 8, and 12. Mice in each of the experimental groups showed dysreglated splenic antioxidant functions, IFN levels, and T-cell subset frequencies, suggesting that the immune system had been affected. The ZEA+DON-treated groups, especially the group that received a higher concentration of ZEA+DON (Group D2Z2), showed more obvious effects on the dysregulation of splenic antioxidant functions, IFN levels, and T-cell subsets. This finding suggested that DON and ZEA exerted synergistic effects.

Idiopathic massive fetomaternal hemorrhage in the third trimester of pregnancy causing neonatal death

Fetomaternal hemorrhage (FMH), which can occur throughout pregnancy, is still a poorly understood clinical condition. It is very difficult to be timely diagnosed and often results in poor pregnancy outcomes. Here the authors reported two rare cases of silent massive FMH of unknown cause in the third trimester of pregnancy, which presented with non-reactive fetal heart rhythm or decreased fetal movement at the very beginning, and resulted in severe fetal anemia and neonatal deaths. A pregnant woman at late pregnancy with a com- plain of unspecific signs such as decreased fetal movement should arouse a high index of clinical suspicion of idiopathic FMH, and an urgent ultrasound or lab tests detecting FMH could be suggested. Considering emergent delivery versus expectantly management will de- pend upon acute or chronic FMH, gestational age, results of fetal testing, availability of experienced personnel, and procedural difficulty.

Molecular identification of Echinococcus granulosus on the Tibetan Plateau using mitochondrial DNA markers

Cystic echinococcosis (CE) is an important worldwide zoonotic disease that causes large economic losses and human suffering. Echinococcus granulosus, the causative agent of CE, exhibits different genotypes in different locations. In order to identify its genotypes and analyze its genetic structure on the Tibetan Plateau, we collected 72 hydatid cysts from different intermediate hosts and amplified and sequenced their mitochondrial cytochrome c oxidase subunit 2 (cox2) genes. Seventy isolates were identified as the E. granulosus G1 genotype, while two isolates belonged to the G6 genotype. There were 18 haplotypes among the 70 E. granulosus isolates, which exhibited a star-like network pattern and shared a common haplotype (H1). There was little difference between geographical sub-populations. Our results suggest that a recent E. granulosus population expansion occurred on the Tibetan Plateau, suggesting that E. granulosus was introduced into China. This study increases the basic molecular data needed for the molecular diagnosis, epidemiology, prevention, and control of Echinococcus diseases.

A dead-zone free ⁴He atomic magnetometer with intensity-modulated linearly polarized light and a liquid crystal polarization rotator

We demonstrate an all-optical (4)He atomic magnetometer experimental scheme based on an original Bell-Bloom configuration. A single intensity-modulated linearly polarized laser beam is used both for generating spin polarization within a single (4)He vapor and probing the spin precessing under a static magnetic field. The transmitted light signal from the vapor is then phase-sensitively detected at the modulation frequency and its harmonics, which lead to the atomic magnetic resonance signals. Based on this structure, a liquid crystal is added in our magnetometer system and constitutes a polarization rotator. By controlling the voltage applied on the liquid crystal, the light linear polarization vector can be kept perpendicular with the ambient magnetic field direction, which in turn provides the maximum resonance signal amplitude. Moreover, the system exhibits a magnetic-field noise floor of about 2pT/√Hz, which is not degraded due to the presence of the liquid crystal and varying magnetic field direction. The experiment results prove that our method can eliminate the dead-zone effect, improve the system spatial isotropy, and thus be suitable in mobile applications.

MicroRNAs in avian influenza virus H9N2-infected and non-infected chicken embryo fibroblasts

There is limited information about microRNAs (miR-NAs) in H9N2 subtype influenza virus-infected chicken cells or tissues. In this study, 10,487,469 and 13,119,795 reads were obtained from in-fected and non-infected chicken embryo fibroblasts, respectively. Seven hundred and thirty-six and 1004 miRNAs, including mature miRNAs and precursors, were obtained from the infected and non-infected fibro-blasts, respectively. Of those miRNAs, 48 were expressed differently between the groups: 37 had a low expression level in the infected chick-en embryo fibroblast, and the remaining 11 had a higher expression level. Every miRNA was predicted to target immune response-related genes. It has been found that some of the miRNAs, such as gga-miR-146c, gga-miR-181a, gga-miR-181b, gga-miR-30b, gga-miR-30c, gga-miR-30e, and gga-miR-455, are expressed differently in other types of influenza-infected chicken cells or tissues.

Reirradiation of nasopharyngeal carcinoma focusing on volumetric modulated arcs with flattening filter-free beams

OBJECTIVE

The goal of this study was to assess the role of flattening filter-free (FFF) beams in volumetric modulated arc radiotherapy for patients with recurrent nasopharyngeal carcinoma (rNPC).

METHODS

13 patients with rNPC were replanned for FFF RapidArc(®) (RA-FFF) and conventional RapidArc (RA) (Varian Medical Systems, Palo Alto, CA). Quantitative evaluation was performed for the planning target volume (PTV) and organs at risk (OARs). Phantom dose verifications, treatment delivery time and monitor units (MUs) were also assessed.

RESULTS

Each technique delivered similar doses to the PTV. RA-FFF had a better sparing effect on the brain stem and normal tissue when compared with RA, whereas RA provided lower mean doses to the skin. No significant difference between the two techniques could be established for other OAR parameters. Both techniques showed equally good gamma scores in dosimetric verification. RA-FFF required more MUs than RA, whereas the delivery time for RA-FFF was slightly shorter than for RA.

CONCLUSION

Both treatment plans met the planning objectives. Dose measurements also showed good agreement with computed doses. In addition to slightly faster delivery times, RA-FFF produced better sparing of brain stem and normal tissue with uncompromised target coverage compared with RA.

ADVANCES IN KNOWLEDGE

FFF beams have recently been assembled for clinical use. Our findings show RA-FFF is useful in the salvage treatment of rNPC owing to better brain stem and normal tissue sparing with uncompromised target coverage compared with RA. This may be beneficial in the case of tumour invasion close to the brain stem.

Effects of sex and age on chicken TBC1D1 gene mRNA expression

The objective of this study was to investigate the effects of sex and slaughter age of chickens on fatty acid composition and TBC1D1 gene expression in 4 different tissues: breast muscle, thigh muscle, abdominal fat, and subcutaneous fat. Sixty Erlang mountainous chickens (hybrid SD02 x SD03) were raised under the same conditions and slaughtered at 8, 10, and 13 weeks of age. The results showed that the sex of the animal significantly affected the content of arachidic acid (C20:0), sinapic (C22:1), linoleic (C18:2n-6), eicosapentaenoic (C20:5n-3), and docosahexaenoic acids (C22:6n-3), whereas other fatty acid contents were not affected. Age had a significant effect on most monounsaturated fatty acids, except for octadecenoic acid (C18:1). TBC1D1 mRNA was abundant in all tissues at all 3 ages of slaughter. Cocks exhibited higher TBC1D1 mRNA levels than hens in the thigh muscle and abdominal fat at 10 and 13 weeks, respectively.

Detection of the long noncoding RNAs nuclear-enriched autosomal transcript 1 (NEAT1) and metastasis associated lung adenocarcinoma transcript 1 in the peripheral blood of HIV-1-infected patients

OBJECTIVES

Long noncoding RNAs (lncRNAs) in HIV-1 infection have not been extensively studied. Here we detected two lncRNAs, nuclear-enriched autosomal transcript 1 (NEAT1) and metastasis associated lung adenocarcinoma transcript 1 (MALAT1), in peripheral blood mononuclear cells (PBMCs) and plasma of HIV-1-infected patients.

METHODS

Fifty-nine HIV-1-infected patients and 21 healthy controls were recruited for the study, of whom 31 patients were highly active antiretroviral therapy (HAART)-naïve and 28 patients had been receiving HAART for more than 1 year with undetectable viral loads. Total RNA was extracted from PBMCs and plasma, and levels of NEAT1 and MALAT1 were determined by quantitative real-time polymerase chain reaction.

RESULTS

We found that the levels of NEAT1 and MALAT1 in PBMCs were up-regulated in HAART-naïve patients and were reduced in patients receiving HAART. NEAT1 was down-regulated in the plasma of infected patients and expression was correlated with CD4 T-cell count.

CONCLUSIONS

Our findings suggest that NEAT1 and MALAT1 may interact with HIV-1 in vivo and that the presence of NEAT1 in plasma is a potential biomarker of HIV-1 infection.

A point mutation of zebrafish c-cbl gene in the ring finger domain produces a phenotype mimicking human myeloproliferative disease

Controlled self-renewal and differentiation of hematopoietic stem/progenitor cells (HSPCs) are critical for vertebrate development and survival. These processes are tightly regulated by the transcription factors, signaling molecules and epigenetic factors. Impaired regulations of their function could result in hematological malignancies. Using a large-scale zebrafish N-ethyl-N-nitrosourea mutagenesis screening, we identified a line named LDD731, which presented significantly increased HSPCs in hematopoietic organs. Further analysis revealed that the cells of erythroid/myeloid lineages in definitive hematopoiesis were increased while the primitive hematopoiesis was not affected. The homozygous mutation was lethal with a median survival time around 14-15 days post fertilization. The causal mutation was located by positional cloning in the c-cbl gene, the human ortholog of which, c-CBL, is found frequently mutated in myeloproliferative neoplasms (MPN) or acute leukemia. Sequence analysis showed the mutation in LDD731 caused a histidine-to-tyrosine substitution of the amino acid codon 382 within the RING finger domain of c-Cbl. Moreover, the myeloproliferative phenotype in zebrafish seemed dependent on the Flt3 (fms-like tyrosine kinase 3) signaling, consistent with that observed in both mice and humans. Our study may shed new light on the pathogenesis of MPN and provide a useful in vivo vertebrate model of this syndrome for screening drugs.

Effect of arousing stimuli on circulating corticosterone and the circadian rhythms of luteinizing hormone (LH) surges and locomotor activity in estradiol-treated ovariectomized (ovx+EB) Syrian hamsters

In most proestrous hamsters, novel wheel exposure phase advances activity rhythms and blocks the preovulatory LH surge, which occurs 2h earlier the next day. Because wheel immobilization does not prevent these effects we hypothesized that arousal alone blocks and phase advances the LH surge. Ovariectomized (ovx) hamsters received a jugular vein cannula and estradiol benzoate (EB) or vehicle was injected sc. The next day (Day 1), at zeitgeber time (ZT) 4-5 (ZT 12 = lights off), after obtaining a blood sample, each hamster was exposed to constant darkness (DD), and either remained in her home cage or was transferred to a new cage and exposed to a running wheel or a 2-hour arousal paradigm. Blood samples were obtained in dim red light and activity was recorded hourly until ~ZT 10-11 on Days 1 and 2. For the next 1-2 weeks, activity was monitored in DD. Plasma LH and corticosterone were assessed by RIA. Novel wheel exposure or arousal at ZT 4 greatly attenuated the Day 1 LH surge in ovx+EB hamsters, and phase advanced the Day 2 LH surge by about 2h. In proestrous hamsters, novel wheel exposure led to a prolonged (>2h) increase in corticosterone levels only when LH surges were blocked. Phase advances in activity rhythms were enhanced by estradiol and arousal. The results suggest that estradiol modulates the effectiveness of non-photic stimuli. The role of the increased activity of the hypothalamic-pituitary-adrenal axis associated with novel wheel-induced attenuation of LH surges in ovx+EB hamsters remains to be determined.

Comparison of valsartan and benazepril when combined with atorvastatin in protecting patients with early cardio-renal syndrome (CRS)

OBJECTIVE

The aims to investigate the different protective effects of valsartan and benazepril when combined with atorvastatin in the cardio-renal functions of cardio-renal syndrome (CRS) patients.

PATIENTS AND METHODS

A total of 200 early CRS patients were enrolled in the present study, including 104 males and 96 females, with an average age of 62.2 ± 7.7 years. The same group of patients were set as the control group prior to treatment, and then randomly divided into two groups; the A group was treated with valsartan (80 mg/d) and atorvastatin (20 mg/d); the B group was treated with benazepril (10 mg/d) and atorvastatin (20 mg/d). The treatment period was 24 months.

RESULTS

The clinical efficacy and clinical events were observed and the following parameters of each patient were measured before and after treatment: 24h urine protein; creatinine clearance; serum brain natriuretic peptide (BNP); high sensitivity C-reactive protein (hsCRP); blood lipid level; liver function and ejection fraction (EF) value. Compared with the control group, the clinical symptoms of the treatment groups were improved with decreased blood lipid levels, significantly decreased serum BNP and hsCRP levels and significantly increased EF values and creatinine clearance rates (p < 0.01). The differences between the two treatment groups were not statistically significant. The number of patients that stopped treatment due to the development of a cough was significantly higher in the B group than the A group (p < 0.01).

CONCLUSIONS

When combined with atorvastatin, both valsartan and benazepril effectively improved the cardio-renal functions of early CRS patients. There was no significant difference between the two treatments however, valsartan appeared to be better tolerated by patients.

Reconstruction of maxillary defects with free fibula flap assisted by computer techniques

OBJECTIVE

Free fibula flaps are widely used for maxillary reconstruction. The three-dimensional position of the fibula flap is very difficult to control in conventional operations based solely on the surgeon's experience. We aimed to improve this surgery by using computerized techniques.

METHODS

Twenty-seven patients with maxillary tumors underwent maxillectomy and free fibula flap reconstruction in our department between 2011 and 2013. Virtual planning and surgical navigation were used for eight patients, and conventional surgery was performed in 19 patients. The three-dimensional fibular positions were evaluated in the two groups. Differences between the postoperative position of the fibular segments and the virtual plans were evaluated in the computer-assisted surgery group.

RESULTS

The three-dimensional position of the fibula flap in the computer-assisted surgery group, including the vertical distance (p = 0.013), horizontal position (p = 0.019) and extension of the posterior end (p = 0.041), was significantly more accurate and nearer to the ideal position than that in the conventional surgery group. The average difference between the actual postoperative position of the fibular segments and the virtual plan in the computer-assisted surgery group was <5 mm.

CONCLUSION

Application of computer-assisted techniques such as virtual planning and surgical navigation significantly improve the clinical outcomes of maxillary reconstruction with free fibula flaps.

Assessment of re-aggregated human pancreatic islets for secondary drug screening

BACKGROUND AND PURPOSE

Insulin secretion from isolated pancreatic islets is a pivotal assay in developing novel insulin secretagogues, given its good correlation with in vivo efficacy. Because the supply of human islets is limited, this assay is typically run with rodent islets, which do not address species differences and are low-throughput, because of the size matching or volume normalization required. Here we have evaluated the suitability of human re-aggregated islets for this assay.

EXPERIMENTAL APPROACH

We generated re-aggregated human islets of a consistent size, using micromolds and compared their responses with those of native human and rat islets, to known secretagogues and inhibitors of insulin release.

KEY RESULTS

Insulin secretion from rat islets, human islets and human re-aggregated cell clusters was concentration-dependently increased by glucose. The calcium channel agonist, Bay K 8644, stimulated insulin secretion in native rat islets and human re-aggregated islets, but not native human islets. Glibenclamide and tolbutamide were more effective and potent in re-aggregated human clusters compared with the other two preparations. Rat islets outperformed both human preparations of islets in response to caffeine, carbachol and glucagon-like peptide-1. Re-aggregated human islet clusters were more sensitive to somatostatin, diazoxide and sodium azide, but rodent islets were more sensitive to nifedipine.

CONCLUSIONS AND IMPLICATIONS

Human re-aggregated clusters of islet cells, of a constant size were more responsive to all compounds tested than native human islets. Importantly, the assay variability was less in the re-aggregated cluster preparations, which suggests that such re-aggregated cells could be useful for drug development.

Effects of antibacterial peptide on cellular immunity in weaned piglets

The aim of this study was to evaluate the effects of antibacterial peptide (ABP) sufficiency on cellular immune functions by determining the spleen cell cycle and apoptosis, peripheral blood T cell subsets, and T cell proliferation function in weaned piglets. A total of 90 piglets (Duroc × Landrace × Yorkshire) of both sexes were randomly allotted to 5 dietary treatments. Each treatment consisted of 3 replicates with 6 piglets per replicate. The dietary treatments consisted of the negative control (NC; basal diet), positive control (PC; basal diet supplemented with 400 mg/kg Astragalus polysaccharide), and ABP (basal diet mixed with 250, 500, and 1,000 mg/kg ABP). The experimental lasted for 28 d. Two piglets from each replicate were selected randomly for blood samples extraction from the jugular vein to obtain peripheral blood T cell subsets, and T cell proliferation function analysis was performed on d 32, 39, 46, and 53. Two piglets from each replicate were selected and euthanized to observe the spleen cell cycle and apoptosis on d 39 and 53. In ABP-sufficient piglets, the G0/G1 phase of the spleen cell cycle was much lower (P < 0.05) and the S and G2 + M phases and proliferation index (PI) were greater (P < 0.05) than in NC piglets. The percentage of apoptotic cells in the spleen significantly decreased under ABP sufficiency (P < 0.05). The proliferation function of peripheral blood T cells increased (P < 0.05) in ABP-sufficient piglets. Percentages of CD3 (+) and CD3 (+)CD4 (+) ratios (d 39, 46, and 53) and CD4 (+)CD8 (+) ratios (d 32, 39, 46, and 53) increased remarkably (P < 0.05) under ABP sufficiency compared with NC. These results suggest that ABP sufficiency could increase the T cell population and proliferation function of T cells and could induce decreased percentages of apoptotic cells. Overall, the cellular immune function was evidently improved in weaned piglets. We suggest optimal dosages of 500 mg/kg ABP for 4-wk addition and 1,000 mg/kg ABP for 2-wk addition.