Cardiac vectors in the healthy human fetus: developmental changes assessed by magnetocardiography and realistic approximations of the volume conductor

This study sought to characterize the developmental changes of three measures used to describe the morphology of the fetal cardiac vector: QRS peak-amplitude, QRS duration and QRS time-amplitude integral. To achieve this objective, we rely on a recently developed methodology for fetal cardiac vector estimation, using multichannel fetal magnetocardiographic (fMCG) recordings and realistic approximations of the volume conductors obtained from free-hand ultrasound imaging. fMCG recordings and 3D ultrasound images were obtained from 23 healthy, uncomplicated pregnancies for a total of 77 recordings performed at gestational ages between 22 and 37 weeks. We report the developmental changes of the cardiac vector parameters with respect to gestational age and estimated fetal weight, as well as their dependence on the estimated ventricular mass derived from cardiac dimensions measured with M-mode ultrasound. The normative values can be used along with the cardiac time intervals reported by previous fMCG studies to assist future clinical studies investigating conditions that affect fetal cardiac function.

Preparation of microencapsulated VEGF gene-modified human umbilical cord mesenchymal stem cells and in vitro culture

BACKGROUND AND OBJECTIVES

The application of microencapsulated stem cells has been shown to have many advantages in various fields of medical research. However, optimal modes for preparation of microencapsulate stem cells need to be improved, and expression and release of products of microencapsulated gene modified stem cells need to be studied in vitro.

AIM OF THE STUDY

To explore the optimal parameters when preparing microencapsulated stem cells, and to investigate the effect of microencapsulation on growth, secretion, and metabolism of genetically modified human Umbilical Cord Mesenchymal Stem Cells (hUCMSCs).

MATERIALS AND METHODS

In this study, the parameters of preparation were regulated by observing the microcapsule shape and size. Live/dead cell viability kits and fluorescein isothiocyanate-labeled dextrans (FD) were used to detect the microencapsulated cell viability, and the permeability of microcapsules, respectively. Vascular endothelial growth factor (VEGF) production in the supernatant of microencapsulated and non-microencapsulated VEGF gene-modified hUCMSCs cultures was measured by ELISA.

RESULTS

The optimal parameters of preparing microcapsules were regulated as followed: bolus velocity was 6 ml/h, and airflow velocity was 3 L/min. The morphology of microcapsules was a spherical structure with a diameter of 450 ± 30 µm. More than 90% of the cells were viable after 21 days of culture. Low and middle molecular weight FD was able to pass through the microcapsules; however, high molecular weight FD was not. Also, the VEGF concentration in microencapsulated and non-microencapsulated cell culture supernatants exhibited no significant difference at each time point.

CONCLUSIONS

Microencapsulated stem cells can be ideally prepared via specifically regulated preparation. Lastly, microencapsulation does not alter growth, secretion, and metabolism of the genetically modified hUCMSCs.

Genome-wide analysis of the AP2/ERF superfamily in peach (Prunus persica)

We identified 131 AP2/ERF (APETALA2/ethylene-responsive factor) genes in material from peach using the gene sequences of AP2/ERF amino acids of Arabidopsis thaliana (Brassicaceae) as probes. Based on the number of AP2/ERF domains and individual gene characteristics, the AP2/ERF superfamily gene in peach can be classified broadly into three families, ERF (ethylene-responsive factor), RAV (related to ABI3/VP1), and AP2 (APETALA2), containing 104, 5, and 21 members, respectively, along with a solo gene (ppa005376m). The 104 genes in the ERF family were further divided into 11 groups based on the group classification made for Arabidopsis. The scaffold localizations of the AP2/ERF genes indicated that 129 AP2/ERF genes were all located on scaffolds 1 to 8, except for two genes, which were on scaffolds 17 and 10. Although the primary structure varied among AP2/ERF superfamily proteins, their tertiary structures were similar. Most ERF family genes have no introns, while members of the AP2 family have more introns than genes in the ERF and RAV families. All sequences of AP2 family genes were disrupted by introns into several segments of varying sizes. The expression of the AP2/ERF superfamily genes was highest in the mesocarp; it was far higher than in the other seven tissues that we examined, implying that AP2/ERF superfamily genes play an important role in fruit growth and development in the peach. These results will be useful for selecting candidate genes from specific subgroups for functional analysis.

Characterizing hepatocellular carcinoma using multi-breath-hold two-dimensional susceptibility-weighted imaging: comparison to conventional liver MRI

AIM

To characterize the imaging manifestations of hepatocellular carcinoma (HCC) using multi-breath-hold two-dimensional susceptibility-weighted imaging (SWI) and compare to conventional liver magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Forty-three patients with histopathologically confirmed HCC underwent conventional liver MRI, multi-breath-hold two-dimensional SWI, and contrast-enhanced CT preoperatively. The T1-weighted imaging (WI), T2WI, and SWI images were evaluated in consensus by two experienced radiologists. The tumour boundaries, blood products in the tumour, venous vessels, and non-tumour liver parenchyma were compared.

RESULTS

SWI demonstrated significantly better tumour boundary detection than T1WI and T2WI imaging (67.4 and 25.6%, respectively). The detection rate for intra-tumoural blood products using SWI was higher than that of T1WI and T2WI (76.7 and 16.3%, respectively). The detection rate for tumour venous vessels using SWI was 72.1%, while none was detected with conventional T1WI and T2WI. The detection rate for siderotic nodules in non-tumour liver parenchyma using SWI was higher than that of conventional T1WI and T2WI (65.1 and 20.9%, respectively).

CONCLUSIONS

SWI can provide more detailed information than conventional liver MRI in evaluation of tumour boundaries, blood products, venous vasculature, and non-tumour liver parenchyma. SWI is a valuable complement to conventional liver MRI.

Survival time comparison between Hawley and clear overlay retainers: a randomized trial

The objectives of this study were to compare the survival time of the Hawley retainer (HR) and the clear overlay retainer (COR) over one-year follow-up and to analyze risk factors contributing to their breakage. In this randomized, controlled clinical trial, we assigned 120 adolescent patients to receive either the HR or the COR. All specific data on breakage dates, the reasons for breakage, and the broken parts of the retainers were recorded. A survival analysis was used to describe retainer survival over time. No significant differences were observed in survival times between the 2 groups for either the maxillary retainer (p = 0.254) or the mandibular retainer (p = 0.188). Both retainers tended to fracture, but the fracture locations were different. The findings indicate that clinicians should avoid increasing buccal root torque and reinforce the retainer base plates. Breakage rates may not influence the choice of retainer (Trial Registration number is ChiCTR-TRC-00000055).

Reducing blood viscosity with magnetic fields

Blood viscosity is a major factor in heart disease. When blood viscosity increases, it damages blood vessels and increases the risk of heart attacks. Currently, the only method of treatment is to take drugs such as aspirin, which has, however, several unwanted side effects. Here we report our finding that blood viscosity can be reduced with magnetic fields of 1 T or above in the blood flow direction. One magnetic field pulse of 1.3 T lasting ~1 min can reduce the blood viscosity by 20%-30%. After the exposure, in the absence of magnetic field, the blood viscosity slowly moves up, but takes a couple of hours to return to the original value. The process is repeatable. Reapplying the magnetic field reduces the blood viscosity again. By selecting the magnetic field strength and duration, we can keep the blood viscosity within the normal range. In addition, such viscosity reduction does not affect the red blood cells' normal function. This technology has much potential for physical therapy.

Self-compatibility in 'Cristobalina' sweet cherry is not associated with duplications or modified transcription levels of S-locus genes

Sweet cherry shows S-RNase-based gametophytic self-incompatibility, which prevents self- and cross-fertilization between genetically related individuals. The specificity of the self-incompatible reaction is determined by two genes located in the S-locus. These encode a pistil-expressed ribonuclease (S-RNase) that inhibits self pollen tube growth, and a pollen-expressed F-box protein (SFB) that may be involved in the cytotoxicity of self-S-RNases. Initial genetic and pollination studies in a self-compatible sweet cherry cultivar, 'Cristobalina' (S (3) S (6)), showed that self-compatibility was caused by the loss of pollen function of both haplotypes (S (3) and S (6)). In this study, we further characterize self-compatibility in this genotype by molecular analysis of the S-locus. DNA blot analyses using S-RNase and SFB probes show no duplications of 'Cristobalina' S-locus genes or differences in the restriction patterns when compared with self-incompatible cultivars with the same S-genotype. Furthermore, reverse transcriptase-PCR of S-locus genes and quantitative reverse transcription-PCR of SFBs revealed no differences at the transcription level when compared with a self-incompatible genotype. The results of this study show that no differences at the S-locus can be correlated with self-compatibility, indicating the possible involvement of non-S-locus modifiers in self-incompatibility breakdown in this cultivar.

Inactivation of AMPK alters gene expression and promotes growth of prostate cancer cells

AMP-activated protein kinase (AMPK) serves as a fuel-sensing enzyme that is activated by binding of AMP and subsequent phophorylation by upstream kinases such as the tumor suppressor LKB1, when cells sense an increase in the ratio of AMP to ATP. Acute activation of AMPK stimulates fatty acid oxidation to generate more ATP and simultaneously inhibits ATP-consuming processes including fatty acid and protein syntheses, thereby preserving energy for acute cell surviving program, while the chronic activation leads to inhibition of cell growth. The goal of the present study is to explore the mechanisms by which AMPK regulates cell growth. Toward this end, we established stable cell lines by introducing a dominant negative mutant of AMPK α1 subunit or its shRNA into the prostate cancer C4-2 cells and other cells, or wild type LKB1 into the lung adenocarcinoma A549 and breast MB-MDA-231 cancer cells, both of which lack functional LKB1. Our results showed that the inhibition of AMPK accelerated cell proliferation and promoted malignant behavior such as increased cell migration and anchorage-independent growth. This was associated with decreased G1 population, downregulation of p53 and p21, and upregulation of S6K, IGF-1 and IGF1R. Conversely, treatment of the C4-2 cells with 5-aminoimidazole-4-carboxamide 1-Dribonucleoside (AICAR), a prototypical AMPK activator, caused opposite changes. In addition, our study using microarray and RT-PCR revealed that AMPK regulated gene expression involved in tumor cell growth and survival. Thus, our study provides novel insights into the mechanisms of AMPK action in cancer cells and presents AMPK as an ideal drug target for cancer therapy.

A novel DFNA5 mutation, IVS8+4 A>G, in the splice donor site of intron 8 causes late-onset non-syndromic hearing loss in a Chinese family

We report here the clinical, genetic, and molecular characteristics of a large Chinese family exhibiting non-syndromic, late-onset autosomal dominant sensorineural hearing loss. Clinical evaluation revealed variable phenotypes of hearing loss in terms of severity and age-at-onset of disease in these subjects. Genome-wide linkage analysis mapped the disease gene to the DFNA5 locus with a maximum two-point log odds score of 5.39 at [theta] = 0 for marker D7S2457. DNA sequencing of DFNA5 revealed a novel heterozygous IVS8+4 A>G substitution in the splice donor site of intron 8. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed skipping of exon 8 in the mutant transcript. This mutation faithfully cosegregated with hearing loss in the family. In addition, the mutation was absent in 100 unrelated control DNA samples of Chinese origin. The IVS8+4 A>G mutation is predicted to create a shift in the reading frame and introduce a stop codon at position 372, thereby resulting in a prematurely truncated DFNA5 protein. Up to date, a total of four mutations in DFNA5 have been reported to lead to hearing impairment, all of them result in skipping of exon 8 at the mRNA level. Our findings provide further support for the hypothesis that DFNA5-associated hearing loss is caused by a very specific gain-of-function mutation.

Nociceptin/orphanin FQ decreases serotonin efflux in the rat brain but in contrast to a kappa-opioid has no antagonistic effect on mu-opioid-induced increases in serotonin efflux

Similar to kappa-opioids, nociceptin/orphanin FQ (OFQ) exerts anti-mu-opioid actions. This may involve interactions within the circuitry controlling 5-HT neurons in the dorsal raphe nucleus (DRN) that project to the nucleus accumbens (NAcc). To test this hypothesis, we compared the effects of OFQ and kappa-opioids on 5-HT efflux in the CNS of freely behaving rats. First, OFQ (30-300 microM) infused into the DRN for 120 min dose-dependently decreased 5-HT efflux in the DRN. The opioid receptor-like 1 (ORL-1) antagonist [Nphe(1)]nociceptin(1-13)NH(2) blocked this effect. Using dual-probe microdialysis we observed that OFQ (300 microM) infused into the DRN for 120 min produced parallel decreases in 5-HT efflux in the DRN and NAcc, suggesting that ORL-1 receptors in the DRN inhibit serotonergic neurons projecting to the NAcc. Also, 5-HT efflux in the NAcc was dose-dependently decreased during OFQ (30-300 microM) infusion into the NAcc. This suggests that OFQ can reduce 5-HT efflux in the NAcc both by inhibiting serotonergic neurons in the DRN and by stimulating ORL-1 receptors in the NAcc. Similar to OFQ, the kappa-opioids U-50,488 (300 microM) and dynorphin A(1-13) (300 microM) infused into the DRN for 120 min decreased 5-HT efflux in the DRN. This effect was blocked only by the kappa-opioid receptor antagonist nor-BNI. Lastly, we compared the ability of OFQ and U-50,488 to block mu-opioid-induced increases in 5-HT. The kappa-opioid U-50,488 (1000 microM) attenuated the increase in 5-HT induced by the mu-opioid agonist endomorphin-1 (300 microM) in the DRN. In contrast, OFQ (300-1000 microM) did not alter mu-opioid-induced increases in 5-HT efflux. In summary, kappa-opioids and OFQ both decreased 5-HT efflux in the CNS. However, in contrast to kappa-opioids, which reversed mu-opioid-induced increases in 5-HT efflux, the anti-mu-opioid effects of OFQ apparently do not involve changes in 5-HT transmission under our experimental conditions.

Cross-tolerance of recipient-derived transforming growth factor-beta dendritic cells

Administration of donor-derived immature dendritic cells (DC) treated with transforming growth factor-beta (TGF-beta) to prevent allograft rejection is not applicable for clinical use. We therefore attempted to explore the use of recipient-derived DC pulsed with donor antigens via the indirect pathway (cross-priming). DC were propagated from C3H (H2(k)) bone marrow (BM) using granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). TGF-beta (0.2 ng/mL) was added at the initiation of culture. The resultant TGF-beta DC were pulsed with B10 (H2(b)) splenocyte lysate. Expression of major histocompatibility complex (MHC) class I and II was not affected, while CD40, CD80, and CD86 costimulatory molecules on DC were significantly inhibited by treatment with TGF-beta. C3H DC pulsed with B10 antigens stimulated a proliferative response in C3H T cells which was inhibited when DC were treated with TGF-beta, and the cytotoxic T-lymphocyte (CTL) activity was also inhibited. This observation correlated with reduced interferon-gamma (IFN-gamma) and increased IL-10 production. A single injection of TGF-beta DC prolonged allograft survival (median survival time [MST] 18 days vs 10 days in no-DC treatment control; P < .05). These data indicated that an approach utilizing recipient DC as a "vaccine" strategy is possible.

Differential effect of orexins (hypocretins) on serotonin release in the dorsal and median raphe nuclei of freely behaving rats

Orexin (hypocretin)-containing neurons in the perifornical hypothalamus project to widespread regions of the brain, including the dorsal and median raphe nuclei [Peyron C, Tighe DK, van den Pol AN, de Lecea L, Heller HC, Sutcliffe JG, Kilduff TS (1998) Neurons containing hypocretin (orexin) project to multiple neuronal systems. J Neurosci 18:9996-10015; Wang QP, Koyama Y, Guan JL, Takahashi K, Kayama Y, Shioda S (2005) The orexinergic synaptic innervation of serotonin- and orexin 1-receptor-containing neurons in the dorsal raphe nucleus. Regul Pept 126:35-42]. Orexin-A or orexin-B was infused by reverse microdialysis into the dorsal raphe nucleus or median raphe nucleus of freely behaving rats, and extracellular serotonin was simultaneously collected by microdialysis and analyzed by high-performance liquid chromatography. We have found that orexin-A produced a dose-dependent increase of serotonin in the dorsal raphe nucleus, but not in the median raphe nucleus. However, orexin-B elicited a small but significant effect in both the dorsal raphe nucleus and median raphe nucleus. Orexins may have regionally selective effects on serotonin release in the CNS, implying a unique interaction between orexins and serotonin in the regulation of activities including sleep-wakefulness.