New alkaloids from the seeds of Notopterygium incisum

Three new alkaloids, N-hexacosanoylanthranilic acid (1), N-octacosanoylanthranilic acid (2) and N-eicosanoyltyramine (3), along with 19 known compounds, were isolated from the seeds of Notopterygium incisum, whose rhizomes are used as a traditional Tibetan medicine. Their structures were elucidated by 1D, 2D NMR spectra and ESI-MS spectrometer evidence.

Glucoregulatory effects and prolonged duration of action of davalintide: a novel amylinomimetic peptide

AIMS

Davalintide is a second-generation amylinomimetic peptide possessing enhanced pharmacological properties over rat amylin to reduce food intake in preclinical models. The current experiments in rats describe additional glucoregulatory actions of davalintide consistent with amylin agonism, and explore the duration of action of these effects.

METHODS

Subcutaneous (SC) injection of davalintide slowed gastric emptying with equal potency to amylin (ED₅₀'s = 2.3 and 4.1 µg/kg). This effect was maintained for 8 h with davalintide, but not amylin. Intraperitoneal injection of davalintide also reduced food intake with a potency similar to amylin (ED₅₀'s = 5.0 and 11.3 µg/kg). Consistent with amylin agonism, davalintide (10 µg/kg, SC) suppressed the plasma glucagon response over 90 min following an intravenous arginine bolus in anaesthetized rats. The elimination t(½) of davalintide (200 µg/kg, SC) was 26 min, similar to the t(½) of amylin, suggesting that pharmacokinetic-independent mechanisms contribute to davalintide's enhanced duration of action. Binding kinetic studies using ¹²⁵I davalintide revealed no appreciable dissociation from the amylin nucleus accumbens receptor after 7 h while ¹²⁵I rat amylin did dissociate from this receptor (K(off) = 0.013/min). Sustained SC infusion of davalintide (275 µg/kg/day) or amylin (300) decreased plasma glucose after an oral glucose challenge at 2 weeks (by 27 and 31%) and suppressed gastric emptying at 3 weeks (by 29 and 47%), demonstrating durable glucoregulatory actions of both peptides.

CONCLUSIONS

These data show glucoregulatory properties of davalintide consistent with amylin agonism and suggest that slowed receptor dissociation plays a role in davalintide's prolonged pharmacodynamic actions.

UCP2 -866G/A and Ala55Val, and UCP3 -55C/T polymorphisms in association with type 2 diabetes susceptibility: a meta-analysis study

AIMS/HYPOTHESIS

A meta-analysis was performed to assess the association between the UCP2 -866G/A, UCP2 Ala55Val and UCP3 -55C/T polymorphisms and type 2 diabetes susceptibility.

METHODS

A literature-based search was conducted to identify all relevant studies. The fixed or random effect pooled measure was calculated mainly at the allele level to determine heterogeneity bias among studies. Further analyses were performed that stratified for ethnicity.

RESULTS

We examined 17 publications. Stratified analysis for ethnicity and sensitivity analysis revealed that there was no heterogeneity between studies for these variants. Using an additive model, no significant association of the UCP2 -866G/A polymorphism with type 2 diabetes risk was observed, either in participants of Asian (OR 1.05, 95% CI 0.96, 1.16) or of European (OR 1.03, 95% CI 0.99, 1.07) descent. Neither the UCP2 Ala55Val nor the UCP3 -55C/T polymorphism showed any significant association with type 2 diabetes risk in Europeans (OR 1.04, 95% CI 0.98, 1.09 for Ala55Val; OR 1.04, 95% CI 1.00, 1.09 for -55C/T). In contrast, a statistically significant association was observed for both polymorphisms in participants of Asian descent (OR 1.23, 95% CI 1.12, 1.36 for Ala55Val; OR 1.15, 95% CI 1.03, 1.28 for -55C/T).

CONCLUSIONS/INTERPRETATION

Our meta-analysis suggests that the UCP2 -866G/A polymorphism is unlikely to be associated with increased type 2 diabetes risk in the populations investigated. In contrast, our results indicate that the UCP2 Ala55Val and UCP3 -55C/T polymorphisms may indeed be risk factors for susceptibility to type 2 diabetes in individuals of Asian descent, but not in individuals of European descent. This conclusion warrants confirmation by further studies.

Regional brain blood flow in mouse: quantitative measurement using a single-pass radio-tracer method and a mathematical algorithm

We have developed a reliable experimental method for measuring local regional cerebral blood flows in anesthetized mice. This method is an extension of the well-established single-pass dual-label indicator method for simultaneously measuring blood flow and glucose influx in rat brains. C57BL6J mice (n = 10) were anesthetized and regional blood flows (ml/min/g) were measured using the radio-tracer method. To test the sensitivity of this method we used a mathematical algorithm to predict the blood flows and compared the two sets of results.Measured regional blood flows between 0.7 and 1.7 ml/min/g were similar to those we have previously reported in the rat. The predicted blood flows using an assumed linearly increasing arterial tracer concentration-versus-time profile (that is, a ramp) were similar to the values measured in the physiological experiments (R(2) 0.99; slope 0.91). Thus,measurements of local regional cerebral blood flow in anesthetized mice using a single-pass radio-tracer method appear to be reliable.

An unusual high-pressure injection injury involving the cervical spinal cord

High-pressure injection injuries occur infrequently but are usually work-related and involve the non-dominant hand. The neck is a very rare site for such an injury. We describe the management of a 36-year-old man with a high-pressure grease-gun injection injury to his neck causing a cervical spinal cord injury. He developed severe motor and sensory changes which were relieved by surgical removal of the grease through anterior and posterior approaches.

Hepatitis B virus X protein downregulates expression of the miR-16 family in malignant hepatocytes in vitro

BACKGROUND

Hepatitis B virus X protein (HBx) is involved in the initiation and progression of hepatocellular carcinoma (HCC) by regulating the host protein-coding genes. In this study, we showed that HBx altered the expression of microRNAs (miRNAs) to promote proliferation and transformation in malignant hepatocytes in vitro.

METHODS

miRNA microarray and quantitative reverse-transcription polymerase chain reactions (qRT-PCRs) were performed to identify miRNAs that were differentially regulated by HBx in HCC cells. Protein, mRNA, and miRNA expression analyses; cell cycle and apoptosis analyses; loss/gain-of-function analysis; and luciferase reporter assays were performed to delineate the consequences of miR-16 family repression in HepG2 cells.

RESULTS

Hepatitis B virus X protein induced widespread deregulation of miRNAs in HepG2 cells, and the downregulation of the miR-16 family was reproducible in HepG2, SK-HEP-1, and Huh7 cells. CCND1, a target of the miR-16 family, was derepressed by HBx in HepG2 cells. c-Myc mediated the HBx-induced repression of miR-15a/16 in HepG2 cells. Ectopically expressed miR-15a/16 suppressed the proliferation, clonogenicity, and anchorage-independent growth of HBx-expressing HepG2 cells by arresting them in the G1 phase and inducing apoptosis, whereas reduced expression of miR-16 accelerated the growth and cell-cycle progression of HepG2 cells.

CONCLUSIONS

Hepatitis B virus X protein altered the in vitro expression of miRNAs in host malignant hepatocytes, particularly downregulating the miR-16 family. Repression of miR-15a/16 is c-Myc mediated and is required for the HBx-induced transformation of HepG2 cells in vitro. Therefore, miR-16 family may serve as a therapeutic target for hepatitis B virus (HBV)-associated HCC.

Endovascular treatment of intracranial ruptured aneurysms associated with arteriovenous malformations: a clinical analysis of 14 hemorrhagic cases

This study investigated and summarized endovascular therapeutic strategies for intracranial ruptured aneurysms associated with arteriovenous malformations (AVMs). Between June 2005 and June 2009, we identified 16 aneurysms in 14 hemorrhagic cases of intracranial AVM using digital subtraction angiography (DSA). Of the 16 aneurysms, 14 were ruptured and two were unruptured. Aneurysms were classified as types I to IV, and were treated. Aneurysm treatment was followed by AVM treatment via various therapies, including embolization, gamma knife radiotherapy, or follow-up and observation to reduce the risk of aneurysm rupture or intracranial hemorrhage. Over a follow-up period ranging from six months to one year, none of the patients had aneurysm ruptures or intracranial hemorrhage. Most (13/14) patients had a Glasgow Outcome Scale (GOS) score of 5, and one patient had a score of 4. Sixteen aneurysms were treated successfully, as confirmed by DSA examination, and no AVMs re-grew. Clinical therapeutic strategies for intracranial ruptured aneurysms associated with AVMs should include aneurysm treatment first to reduce the risk of rupture and intracranial hemorrhage, eventually leading to a better prognosis.

In vivo assessment of chitosan/β-glycerophosphate as a new liquid embolic agent

We sought to assess the feasibility of using thermosensitive chitosan/β-glycerophosphate forembolotherapy. The renal arteries in nine rabbits were embolized with chitosan/β-glycero-phosphate. The animals were studied angiographically and sacrificed at one week (n = 3), four weeks (n = 3), and eight weeks (n = 3) after embolotherapy. Histology was obtained at these three time points. Delivery of chitosan/β-glycerophosphate was successful in all cases. Complete occlusion was achieved in all cases. No recanalization was observed in the follow-up angiograms. No untoward inflammatory reactions were observed in the target renal arteries and infarcted kidneys during the histological examinations. Our preliminary feasibility evaluation in rabbit renal arteries indicates that C/GP is a satisfactory embolization agent.

Adult endothelial progenitor cells retain hematopoiesis potential

Hematopoietic stem cells (HSCs) are derived from endothelium in the aortic-gonado-mesonephric (AGM) region during embryogenesis. But little is known about whether endothelial progenitor cells (EPCs) retain hematopoiesis potential after birth. In this study, we isolated adult EPCs from the bone marrow of C57BL/6 mice and identified them with an endothelial functional assay and by the CD31(+) CD133(+) CD45(-/dim) VEGFR2(+) phenotype. EPCs isolated from green fluorescence protein (GFP) transgenic C57BL/6 mice were cotransfused with bone marrow cells from wild-type C57BL/6 mice into lethally irradiated BABL/c mice. One month after transplantation, granulocytes (25.73 ± 5.43%) and lymphocytes (12.68 ± 3.26%) in peripheral blood showed GFP(+), referred to as donor EPC-derived blood cells. After an additional month, the percentage of GFP(+) granulocytes decreased to (3.69 ± 1.43%), whereas the percentage of GFP(+) lymphocytes showed no significant difference. Most of the GFP(+) elements showed a diffuse distribution in the spleen; but some were present as aggregates forming lymphoid nodules. GFP(+) endothelial cells were observed in the liver sinusoids, intestinal villi, and lung of recipient mice. These results indicated that adult EPCs not only took part in vasculogenesis, but also retained hematopoietic ability.

Vascular endothelium changes after conditioning in hematopoietic stem cell transplantation: role of cyclophosphamide and busulfan

Vascular endothelial injury, a feature of some complications of hematopoietic stem cell transplantation (HSCT), is characterized by increased endothelial cells. We investigated that classical pretreatment drugs in HSCT could result in vascular endothelial injury in mice. Six-to eight-week-old female BALB/c mice were divided into a control group, a cyclophosphamide group (60 mg/kg per day for 2 days) and a busulfan group (4 mg/kg per day for 4 days). We observed the general state of health and regularly counted the number of white blood cells. Circulating endothelial cells and their progenitors were estimated by flow cytometry. Morphologic endothelial changes were analyzed with optical and transmission electron microscopy. After conditioning with cyclophosphamide or busulfan, white blood cells fell to a low number with injuries noted on hematoxylin and eosin-stained pathology sections. Circulating endothelial cells and their progenitors peaked significantly higher than in the control group. Vascular endothelial injuries were observed in the 2 experimental groups by transmission electron microscopy. These data support the hypothesis the vascular endothelial injury occurs during conditioning with cyclophosphamide or busulfan for HSCT, with simultaneous mobilization of endothelial progenitor cells.

Non-Crystallizing Molten Salt and Ionic Rubber Electrolytes with Wide Electrochemical Windows

New realizations of the type of ambient temperature lithium ion conducting electrolyte introduced at this symposium two years ago are given and a 5 volt electrochemical window, absent from the earlier examples, is demonstrated. The new systems satisfy the criteria for “ionic oils” though their conductivities, - 10-3 S cm-1, are smaller than desirable.

Temperature Dependence of the Optical Properties for InN Films Grown by RF-MBE

InN epitaxial layers are grown on sapphire substrates. The investigated samples have electron concentration in a range of 1.8 ×1018 − 1.1 ×1019 cm-3. Optical reflection and transmission measurements are performed. The plasma edge energy position in the spectra is constant in a measurement temperature range of 5 – 300 K. The reflection and transmission spectra are calculated on the basis of the LO phonon-electron coupling scheme and non-parabolic conduction band structure. From this analysis we find that the observed absorption edge is attributed to valence band to conduction band transition rather than the valence band to defect (impurity) band transition, and the intrinsic bandgap energy of 0.64 (±0.03) eV. This bandgap energy increases by 40 – 50 meV as the temperature decreases from 295 to 10 K.

Endovascular treatment of aneurysms arising from the basilar artery trunk and branches

This study reports our experience with the endovascular treatment of basilar artery (BA) trunk and branch aneurysms. Subjects included 16 patients with BA trunk and branch aneurysms who underwent endovascular treatment in our hospital from October 2000 to October 2009, including four patients with associated arteriovenous malformation (AVM), two with associated moyamoya disease, one with multiple aneurysms at adjacent sites, and one with a distant aneurysm. Endovascular coil embolization, together with stent or balloon assistance when necessary, or while occluding the parent artery was performed. Associated diseases were managed intraoperatively or in the second stage, or treated with gamma knife radiotherapy, or followed up. Two patients with unsuccessful embolization died of re-rupture at the fourth month and fifth month follow-up. The remaining 14 patients reported good outcomes and experienced no re-rupture of either the aneurysm or associated disease. Angiographic follow-ups were conducted for the 14 patients for six to 12 months. Digital subtraction angiography (DSA) examination at the last follow-up showed no recurrence of the BA trunk and branch aneurysms. Together, BA trunk and branch aneurysms should be actively managed via endovascular techniques to prevent serious consequences due to aneurysm rupture and bleeding. Favorable outcomes can be obtained by the proper selection of endovascular treatment regimens.

Endovascular treatment of intracranial aneurysms associated with moyamoya disease or moyamoya syndrome

Direct surgical clipping proves to be difficult and dangerous for intracranial aneurysms associated with moyamoya disease (MMD) or moyamoya syndrome (MMS). This study presents our clinical experience of endovascular embolization of intracranial aneurysms associated with these diseases. A total of 13 cases of intracranial aneurysms associated with MMD or MMS were treated by endovascular embolization between January 2001 and January 2009. Patients were divided into two groups: a saccular aneurysm group (n=10) and a pseudoaneurysm group (n=3). Different endovascular therapeutic strategies were employed for each type of case. Of the 13 cases, 11 received successful endovascular embolization and had an uneventful postoperative course during one to two years of follow-up. However, endovascular embolization failed in the other two cases, of whom one died from rebleeding after the five-month follow-up, while the other was conservatively treated and experienced no rebleeding during the two-year follow-up. A favorable prognosis may be secured through careful selection of endovascular treatment regimens for patients with intracranial aneurysms associated with MMD or MMS according to the site of intracranial aneurysms.

The role of fibroblast Tiam1 in tumor cell invasion and metastasis

The co-evolution of tumors and their microenvironment involves bidirectional communication between tumor cells and tumor-associated stroma. Various cell types are present in tumor-associated stroma, of which fibroblasts are the most abundant. The Rac exchange factor Tiam1 is implicated in multiple signaling pathways in epithelial tumor cells and lack of Tiam1 in tumor cells retards tumor growth in Tiam1 knock-out mouse models. Conversely, tumors arising in Tiam1 knock-out mice have increased invasiveness. We have investigated the role of Tiam1 in tumor-associated fibroblasts as a modulator of tumor cell invasion and metastasis, using retroviral delivery of short hairpin RNA to suppress Tiam1 levels in three different experimental models. In spheroid co-culture of mammary epithelial cells and fibroblasts, Tiam1 silencing in fibroblasts led to increased epithelial cell outgrowth into matrix. In tissue-engineered human skin, Tiam1 silencing in dermal fibroblasts led to increased invasiveness of epidermal keratinocytes with premalignant features. In a model of human breast cancer in mice, co-implantation of mammary fibroblasts inhibited tumor invasion and metastasis, which was reversed by Tiam1 silencing in co-injected fibroblasts. These results suggest that stromal Tiam1 may play a role in modulating the effects of the tumor microenvironment on malignant cell invasion and metastasis. This suggests a set of pathways for further investigation, with implications for future therapeutic targets.

Distribution of NBCn2 (SLC4A10) splice variants in mouse brain

The five known Na-coupled HCO(3)(-) transporters (NCBTs) of the solute carrier 4 (SLC4) family play important roles in pH regulation and transepithelial HCO(3)(-) transport. Nearly all of the NCBTs have multiple splice variants. One particular NCBT, the electroneutral Na/HCO(3)(-) cotransporter NBCn2 (SLC4A10), which is predominantly expressed in brain, has three known splice variants-NBCn2-A, -B, and -C-as well as a potential variant-D. It is important to know the tissue-specific expression of the splice variants for understanding the physiological roles of NBCn2 in central nervous system. In the present study, we developed three novel rabbit polyclonal antibodies against NBCn2: (1) anti-ABCD, which recognizes all four variants; (2) anti-BD, which recognizes NBCn2-B and -D; (3) anti-CD, which recognizes NBCn2-C and -D. By western blotting, we examined the expression and distribution of NBCn2 splice variants in five brain regions: cerebral cortex, subcortex, cerebellum, hippocampus, and medulla. The expression pattern revealed with anti-ABCD is distinct from those revealed with anti-BD and anti-CD. Moreover, by using immunoprecipitation in combination with western blotting, we demonstrate that NBCn2-D does indeed exist and that it is predominantly expressed in subcortex, to a lesser extent in medulla, but at very low levels in cortex, cerebellum, and hippocampus. NBCn2-A may be the dominant variant in mouse brain as a whole, and may also dominate in cerebral cortex, cerebellum, and hippocampus. Immunohistochemistry with anti-ABCD shows that NBCn2 is highly expressed in choroid plexus, cortex, molecular layer of cerebellum, hippocampus, and some specific regions of the brainstem.

Microsurgical clipping of intracranial aneurysms following unsuccessful endovascular treatment. Analysis of ten cases

The purpose of the current study was to examine the reasons for failed endovascular aneurysm coiling and to determine the outcome of immediate microsurgical clipping. From July 2006 to July 2008, 198 patients underwent endovascular coiling at our institute; among them, ten cases were unsuccessful. All of the patients were diagnosed with intracranial aneurysms (ICAs) by cranial computed tomography angiography (CTA), and all underwent endovascular treatment without digital subtraction angiography (DSA). When endovascular coiling failed, the patients were immediately transferred to the operating room for microsurgical clipping under the same anesthetic. The ten patients were divided into three groups based on the cause of endovascular failure and associated clinical features. The clinical follow-up period was between 6-12 months, and all 10 patients had good outcomes following the surgery. Taken together, the results of this study suggest that immediate microsurgical clipping after failed endovascular coiling is efficient and may provide improved outcomes by preventing rebleeding.