[Intestinal absorption characteristics of gastrodigenin in rats]

OBJECTIVE

To investigate the intestinal absorption characteristics of gastrodigenin.

METHOD

In vitro everted gut sac model and in situ rat single-pass intestinal perfusion model were used to evaluate the absorption characteristics of gastrodigenin in the different intestinal segments. The concentrations of gastrodigenin in the samples were determined by Ultra Performance Liquid Chromatography (UPLC) method, and the relevant absorption parameters were calculated.

RESULT

In the everted gut sac tests, no significant difference of absorption among the four segments was observed. A positive correlation was found between drug concentration and the accumulated absorption amount (Q). At the concentration of 400 mg x L(-1), the Q of gastrodigenin in the duodenum, jejunum, ileum and colon were 224.33, 225.81, 233.18 and 189.25 microg, respectively. The in situ rat single-pass intestinal perfusion tests showed that there was also no significant difference of absorption among the four segments. The absorption rates (A) of gastrodigenin in the duodenum, jejunum, ileum and colon were 45.8%, 48.39%, 47.00%, 54.35%, respectively.

CONCLUSION

Gastrodigenin can be well absorbed via passive diffusion in the intestine. The absorption rates of gastrodigenin in the different intestinal segments show no regioselectivity.

Two-wave mixing in chiral dye-doped nematic liquid crystals

Two-wave mixing in nematic liquid crystals doped with dyes and chiral agents is studied. The photo-induced spatial modulation of the chiral structure, together with the diffusion anisotropy of the mixture, determine a relatively fast response time, a spatial resolution of 1 μm, and a maximum gain for circularly polarized interacting beams. The gain is insensitive to changes in linear polarization, while it varies with the grating period and with the pump-to-signal intensity ratio.

Design & control of a 3D stroke rehabilitation platform

An upper limb stroke rehabilitation system is developed which combines electrical stimulation with mechanical arm support, to assist patients performing 3D reaching tasks in a virtual reality environment. The Stimulation Assistance through Iterative Learning (SAIL) platform applies electrical stimulation to two muscles in the arm using model-based control schemes which learn from previous trials of the task. This results in accurate movement which maximises the therapeutic effect of treatment. The principal components of the system are described and experimental results confirm its efficacy for clinical use in upper limb stroke rehabilitation.

Severe diffuse non-scarring hair loss in systemic lupus erythematosus - clinical and histopathological analysis of four cases

BACKGROUND

Although diffuse non-scarring hair loss been found common in systemic lupus erythematosus (SLE), study that conduted on the severe type has been scarce.

OBJECTIVE

This study aims to explore the dermoscopic and pathological features of severe diffuse hair loss in SLE.

METHOD

Data including clinico-laboratory, dermoscopic and histopathological findings of four patients with SLE with severe diffuse hair loss were analysed retrospectively.

RESULTS

All four patients were women aged 41, 39, 14 and 48 with complaints of hair loss involving 55%, 100%, 60% and 55% of their scalp respectively. Common clinical findings observed in the patients were sparse scalp hair with clusters of newly regrown hair. Scalp dermoscopy showed scaling, perifollicular telangiectasia, increased numbers of short vellus hairs, focal atrichia and decreased hair shaft pigmentation. Scalp tissue histopathology revealed typical changes of SLE such as epidermal atrophy with focal liquefaction, degeneration of the basement membrane zone, pigment incontinence, mild focal perivascular and perifollicular lymphocytic infiltrates and deposition of immunoglobulins at the dermal-epidermal junction. Treatment and improvement in SLE disease activity indices had a favourable impact on hair regrowth.

CONCLUSION

The severe type of hair loss in patient with SLE presents a unique set of clinical, dermoscopic and histopathological features.

Structure of Sad1-UNC84 homology (SUN) domain defines features of molecular bridge in nuclear envelope

The SUN (Sad1-UNC-84 homology) domain is conserved in a number of nuclear envelope proteins involved in nuclear migration, meiotic telomere tethering, and antiviral responses. The LINC (linker of nucleoskeleton and cytoskeleton) complex, formed by the SUN and the nesprin proteins at the nuclear envelope, serves as a mechanical linkage across the nuclear envelope. Here we report the crystal structure of the SUN2 protein SUN domain, which reveals a homotrimer. The SUN domain is sufficient to mediate binding to the KASH (Klarsicht, ANC-1, and Syne homology) domain of nesprin 2, and the regions involved in the interaction have been identified. Binding of the SUN domain to the KASH domain is abolished by deletion of a region important for trimerization or by point mutations associated with nuclear migration failure. We propose a model of the LINC complex, where the SUN and the KASH domains form a higher ordered oligomeric network in the nuclear envelope. These findings provide the structural basis for understanding the function and the regulation of the LINC complex.

Formulation and evaluation of in situ gelling systems for intranasal administration of gastrodin

Gastrodin is the major bioactive constituent of the traditional Chinese drug "Tianma." It is used in the treatment of some nervous system diseases and can be transported to the brain via intranasal administration. In the current paper, the development of a novel ion-activated in situ gelling system for the nasal delivery of gastrodin is discussed. An in situ perfusion model was used to determine the absorption-rate constant of gastrodin through rat nasal mucosa. The optimal formulation was determined by measuring the critical cation concentration, anti-dilution capacity, gel expansion coefficient, water-holding capacity, and adhesive capacity. The best formulation consisted of 10% gastrodin, 0.5% deacetylated gellan gum as the gelatinizer, and 0.03% ethylparaben as the preservative. The rheological properties of gastrodin nasal in situ gels were also investigated. The viscosity and elasticity sharply increased at temperatures below 25°C. When physiological concentrations of cations were added into the preparation, the mixture gelled into a semi-solid. The results of an accelerated stability test show that gastrodin nasal in situ gels can be stable for more than 2 years. Mucociliary toxicity was evaluated using the in situ toad palate model and the rat nasal mucociliary method; both models demonstrated no measurable ciliotoxicity. Pharmacodynamic studies suggest that similar acesodyne and sedative effects were induced following intranasal administration of 50 mg/kg gastrodin nasal in situ gels or oral administration of 100 mg/kg gastrodin solution. The in situ gel preparation is a safe and effective nasal delivery system for gastrodin.

Pairwise shared genomic segment analysis in high-risk pedigrees: application to Genetic Analysis Workshop 17 exome-sequencing SNP data

We applied our method of pairwise shared genomic segment (pSGS) analysis to high-risk pedigrees identified from the Genetic Analysis Workshop 17 (GAW17) mini-exome sequencing data set. The original shared genomic segment method focused on identifying regions shared by all case subjects in a pedigree; thus it can be sensitive to sporadic cases. Our new method examines sharing among all pairs of case subjects in a high-risk pedigree and then uses the mean sharing as the test statistic; in addition, the significance is assessed empirically based on the pedigree structure and linkage disequilibrium pattern of the single-nucleotide polymorphisms. Using all GAW17 replicates, we identified 18 unilineal high-risk pedigrees that contained excess disease (p < 0.01) and at least 15 meioses between case subjects. Eighteen rare causal variants were polymorphic in this set of pedigrees. Based on a significance threshold of 0.001, 72.2% (13/18) of these pedigrees were successfully identified with at least one region that contains a true causal variant. The regions identified included 4 of the possible 18 polymorphic causal variants. On average, 1.1 true positives and 1.7 false positives were identified per pedigree. In conclusion, we have demonstrated the potential of our new pSGS method for localizing rare disease causal variants in common disease using high-risk pedigrees and exome sequence data.

Cytomegalovirus infection in mesenchymal stem cells and their activation could be enhanced by nuclear factor-κB inhibitor pyrrolidinedithiocarbamate in vitro

Because of the central role of the transcription factor nuclear factor (NF)-κB in cell survival and proliferation in many kinds of cancer cells, NF-κB inhibitors may have a potential role in cancer therapy. Currently, many NF-κB inhibitors are used for immunosuppression to treat hematologic malignancy patients after stem cell transplantation (SCT). Human cytomegalovirus (HCMV) infection is one of the most common complications following SCT. Some workers have reported that HCMV infection has a close relationship to NF-κB activation; however, the specific effects of NF-κB inhibitors, such as pyrrolidinedithiocarbamate (PDTC), on infection with and activation of CMV in mesenchymal stem cells (MSCs) remain unknown. In our study, we isolated MSCs from the bone marrows of healthy human donors for infection with 1 tcid(50) of HCMV with or without 1 μmol/L PDTC. After 48 hours of culture in dmem supplemented with 10% (volume per volume) fetal calf serum, we tested MSCs using reverse transcription-polymerase chain reaction (RT-PCR) assays to detect messenger RNA (mRNA) expression of HCMV immediate early (IE) gene and the GAPDH gene. Flow cytometry was used to detect HCMV pp65 antigen-positive cells and transmission electron microscopy (TEM) for intra cellular HCMV particles. We observed that the shape of the MSCs changed in response to infection by 1 TCID(50) of HCMV. MSCs infected by 1 TCID(50) of HCMV in combination with 1 μmol/L of PDTC changed their shapes more profoundly; almost all cells went from a thin elongated profile to a round, thick ball. In contrast, the shape of cells treated with PDTC alone or the HCMV mock-infected elements did not change. The RT-PCR assay showed that there was a bright band corresponding to HCMV IE mRNA in MSCs infected with 1 TCID(50) of HCMV in combination with 1 μmol/L of PDTC, as compared with cells infected by only 1 TCID(50) of HCMV. The HCMV mock-infected MSCs did not express HCMV IE mRNA. Using flow cytometry, we detected more HCMV pp65 antigen-positive cells among MSCs infected with 1 TCID(50) of HCMV in combination with 1 μmol/L of PDTC. HCMV particles were observed by TEM in the nucleus and cytoplasm of MSCs infected with HCMV. There were more HCMV particles in cells infected by HCMV in combination with PDTC. In conclusion, NF-κB activation may affect HCMV infection efficiency of MSCs. An NF-κB inhibitor increased the infection by activation of HCMV in MSCs, thus we should pay close attention to HCMV infection when we prescribe an NF-κB inhibitor in clinical settings.

Transforming growth factor-β1 modulates lipopolysaccharide-induced cytokine/chemokine production and inhibits nuclear factor-κB, extracellular signal-regulated kinases and p38 activation in dendritic cells in mice

Tolerogenic dendritic cells (DCs) are crucial for peripheral tolerance mediated by a variety of cytokines, including transforming growth factor-β1 (TGF-β1). We have observed that TGF-β1-treated DCs (TGFβ-DCs) were resistant to the maturation stimulus of lipopolysaccharide (LPS) and that TGF-β1 down-regulated Toll-like receptor 4 (TLR4) expression on DCs. The purpose of this study was to analyze whether TGF-β1 affected the production of cytokines/chemokines and proteins in the TLR4 signal transduction pathway following LPS stimulation. We observed that TGF-β1 induced a significant increase in interleukin (IL)-10, impaired IL-12 secretion, and attenuated messenger RNA (mRNA) expression of chemokines CCL2, CCL3, and CXCL10 in DCs following LPS administration. We also noted that TGF-β1 suppressed LPS-induced activation of nuclear factor (NF)-κB, extracellular signal-related kinases (ERK)-1/2, and p38 in DCs. Taken together, our results identified the suppressive effects of TGF-β1 on TLR4 signal transduction, strengthening the notion that TGFβ-DCs are a unique type of tolerogenic DC exhibiting distinct characteristics.

Intranasal administration of insulin-like growth factor-1 protects against lipopolysaccharide-induced injury in the developing rat brain

Our previous studies show that insulin-like growth factor-1 (IGF-1) can either protect against or increase lipopolysaccharide (LPS)-induced damage in the developing brain, depending on the dose, when it is co-administered with LPS through intracerebral injection. To further explore effects of IGF-1 on central inflammation associated brain injury, IGF-1 was administered through intranasal infusion in the current study. Postnatal day 5 (P5) rats were exposed to LPS at a dose of 1 μg/g body weight or sterile saline through intracerebral injection. Recombinant human insulin-like growth factor-1 (rhIGF-1) at a dose of 50 μg/pup or vehicle was administered intranasally 1 or 2 h after the LPS injection. Neonatal LPS exposure resulted in oligodendrocyte (OL) and white matter injury in the P6 or P21 rat brain. The damages include dilatation of lateral ventricles, pyknotic cell death, loss of OL progenitor cells and mature OLs in the cingulum area, and impairment of myelination at the corpus callosum area. Neurological dysfunctions were observed in juvenile rats with neonatal LPS exposure. Intranasal IGF-1 treatment at either 1 or 2 h after LPS exposure significantly attenuated LPS-induced brain injury and improved some behavioral deficits. Intranasal IGF-1 treatment also reduced infiltration of polymorphonuclear (PMN) leukocytes and activation of microglia in the rat brain 24 h after LPS exposure, but it did not prevent the elevation in concentrations of interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNFα) in the LPS-exposed rat brain during the first 24 h. This is an indication that direct anti-inflammation might not be the primary mechanism for the protection of IGF-1, and other mechanisms, such as anti-apoptotic effects, are likely involved in its protective effects.

The expression of histone demethylase JMJD1A in renal cell carcinoma

BACKGROUND

Hypoxia-inducible factor 1α has been shown to play a central role in RCC tumorigenesis by acting as a transcription factor. Histone demethylase JMJD1A is an iron- and 2-oxoglutarate-dependent dioxygenase which catalyze the demethylation of mono- and dimethylated H3K9. JMJD1A can be upregulated by hypoxia via HIF-1 and associated with cancer. The expression of JMJD1A was determined in 10 kidney cancer tissue and adjacent tissue by quantitative polymerase chain reaction, western blotting and immunohistochemistry. Furthermore, the expression of JMJD1A was investigated in cell line 786-0 through adding nickle or cobalt ion to mimic hypoxic environment. The expression of JMJD1A was higher in cancer tissue than adjacent tissue, and in hypoxic environment than normal environment. In cancer tissue, the JMJD1A mainly located around blood vessels which indicated that JMJD1A is involved tumor angiogenesis.

CONCLUSION

the increased expression of JMJD1A might be associated with the progression of kidney cancer.

KEYWORDS

renal cell carcinoma, histone demethylase, JMJD1A, hypoxia-inducible factor, iron.

Near tubule and intertubular bovine dentin mapped at the 250 nm level

In this study, simultaneous diffraction and fluorescence mapping with a (250nm)(2), 10.1keV synchrotron X-ray beam investigated the spatial distribution of carbonated apatite (cAp) mineral and elemental Ca (and other cations including Zn) around dentin tubules. In 1μm thick sections of near-pulp root dentin, where peritubular dentin (PTD) is newly forming, high concentrations of Zn, relative to those in intertubular dentin (ITD), were observed adjacent to and surrounding the tubule lumens. Some but not all tubules exhibited hypercalcified collars (high Ca signal relative to the surrounding ITD), and, when present, the zone of high Ca did not extend around the tubule. Diffraction rings from cAp 00.2 and 11.2+21.1+30.0 reflections were observed, and cAp was the only crystal phase detected. Profiles of Ca, Zn and cAp diffracted intensities showed the same transitions from solid to tubule lumen, indicating the same cAp content and organization in ITD far from the tubules and adjacent to them. Further, the matching Ca and diffraction profiles demonstrated that all of the Ca is in cAp or that any noncrystalline Ca was uniformly distributed throughout the dentin. Variation of 00.2 and 11.2+21.1+30.0 diffracted intensity was consistent with the expected biaxial crystallographic texture. Extension of X-ray mapping from near 1μm resolution to the 250nm level, performed here for dentin and its tubules, will provide new understanding of other mineralized tissues.

IDH1 and IDH2 mutations in pediatric acute leukemia

To investigate the frequency of isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) mutations in pediatric acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL), we sequenced these genes in diagnostic samples from 515 patients (227 AMLs and 288 ALLs). Somatic IDH1/IDH2 mutations were rare in ALL (N=1), but were more common in AML, occurring in 3.5% (IDH1 N=3 and IDH2 N=5), with the frequency higher in AMLs with a normal karyotype (9.8%). The identified IDH1 mutations occurred in codon 132 resulting in replacement of arginine with either cysteine (N=3) or histidine (N=1). By contrast, mutations in IDH2 did not affect the homologous residue but instead altered codon 140, resulting in replacement of arginine with either glutamine (N=4) or tryptophan (N=1). Structural modeling of IDH2 suggested that codon 140 mutations disrupt the enzyme's ability to bind its substrate isocitrate. Accordingly, recombinant IDH2 R140Q/W were unable to carry out the decarboxylation of isocitrate to α-ketoglutarate (α-KG), but instead gained the neomorphic activity to reduce α-KG to R(-)-2-hydroxyglutarete (2-HG). Analysis of primary leukemic blasts confirmed high levels of 2-HG in AMLs with IDH1/IDH2 mutations. Interestingly, 3/5 AMLs with IDH2 mutations had FLT3-activating mutations, raising the possibility that these mutations cooperate in leukemogenesis.