Hydrodynamics-based transfection in animals by systemic administration of plasmid DNA

Development of methods that allow an efficient expression of exogenous genes in animals would provide tools for gene function studies, treatment of diseases and for obtaining gene products. Therefore, we have developed a hydrodynamics-based procedure for expressing transgenes in mice by systemic administration of plasmid DNA. Using cDNA of luciferase and beta-galactosidase as a reporter gene, we demonstrated that an efficient gene transfer and expression can be achieved by a rapid injection of a large volume of DNA solution into animals via the tail vein. Among the organs expressing the transgene, the liver showed the highest level of gene expression. As high as 45 microg of luciferase protein per gram of liver can be achi- eved by a single tail vein injection of 5 microg of plasmid DNA into a mouse. Histochemical analysis using beta-galactosidase gene as a reporter reveals that approximately 40percent of hepatocytes express the transgene. The time-response curve shows that the level of transgene expression in the liver reaches the peak level in approximately 8 h after injection and decreases thereafter. The peak level of gene expression can be regained by repeated injection of plasmid DNA. These results suggest that a simple, convenient and efficient method has been developed and which can be used as an effective means for studying gene function, gene regulation and molecular pathophysiology through gene transfer, as well as for expressing proteins in animals.

An activating immunoreceptor complex formed by NKG2D and DAP10

Many immune receptors are composed of separate ligand-binding and signal-transducing subunits. In natural killer (NK) and T cells, DAP10 was identified as a cell surface adaptor protein in an activating receptor complex with NKG2D, a receptor for the stress-inducible and tumor-associated major histocompatibility complex molecule MICA. Within the DAP10 cytoplasmic domain, an Src homology 2 (SH2) domain-binding site was capable of recruiting the p85 subunit of the phosphatidylinositol 3-kinase (PI 3-kinase), providing for NKG2D-dependent signal transduction. Thus, NKG2D-DAP10 receptor complexes may activate NK and T cell responses against MICA-bearing tumors.

Association between obesity and kidney disease: a systematic review and meta-analysis

This study aimed to comprehensively assess epidemiologic evidence on the relation between obesity and kidney disease (KD). From 247 retrieved articles via PubMed (1980-2006), 25 cohorts, 3 cross-sectional, and 19 case-control studies met inclusion criteria. Related data were extracted using a standardized protocol. We estimated the pooled relative risk (RR) and 95% confidence interval (95% CI) of KD for each body mass index (BMI) category compared with normal weight using meta-analysis models. Population attributable risk was also calculated. Compared with normal-weight individuals (18.5<BMI<25), overweight individuals (25< or =BMI<30) had elevated risk for KD (RR=1.40; 95% CI 1.30-1.50); obese individuals were at much higher risk (RR=1.83 (1.57-2.13)). Obesity in women was associated with a higher risk than in men (RR=1.92 (1.78-2.07) vs 1.49 (1.36-1.63); P<0.001). Results from cohort studies in patient populations and cross-sectional and case-control studies all indicated a positive association between BMI and risks for KD outcomes. We estimated that 24.2% and 33.9% of KD cases among US men and women, respectively, and in industrialized countries, 13.8% in men and 24.9% in women, could be related to overweight and obesity. Obesity increases the risk for KD in the general population, and the association appears to be stronger in women than in men. Obesity adversely affects the progress of KD among patients with kidney-related diseases.

Defective secretion of saliva in transgenic mice lacking aquaporin-5 water channels

Aquaporin-5 (AQP5) is a water-selective transporting protein expressed in epithelial cells of serous acini in salivary gland. We generated AQP5 null mice by targeted gene disruption. The genotype distribution from intercross of founder AQP5 heterozygous mice was 70:69:29 wild-type:heterozygote:knockout, indicating impaired prenatal survival of the null mice. The knockout mice had grossly normal appearance, but grew approximately 20% slower than litter-matched wild-type mice when placed on solid food after weaning. Pilocarpine-stimulated saliva production was reduced by more than 60% in AQP5 knockout mice. Compared with the saliva from wild-type mice, the saliva from knockout mice was hypertonic (420 mosM) and dramatically more viscous. Amylase and protein secretion, functions of salivary mucous cells, were not affected by AQP5 deletion. Water channels AQP1 and AQP4 have also been localized to salivary gland; however, pilocarpine stimulation studies showed no defect in the volume or composition of saliva in AQP1 and AQP4 knockout mice. These results implicate a key role for AQP5 in saliva fluid secretion and provide direct evidence that high epithelial cell membrane water permeability is required for active, near-isosmolar fluid transport.

Inflammation of small airways in asthma

This study was designed to examine the inflammatory process in the central and peripheral airways of surgically resected lungs from asthmatic and nonasthmatic subjects. Lung specimens were inflated with cryoprotective, rapidly frozen, and systematically sampled. Cryosections prepared from frozen tissue blocks were fixed in acetone/methanol and immunostained with monoclonal antibodies by using the alkaline phosphatase-anti-alkaline phosphatase technique to detect CD3 (T cells), major basic protein (total eosinophils), EG2 (activated eosinophils), anti-tryptase (mast cells), anti-elastase (neutrophils), and CD68 (macrophages). All airways from patients with asthma demonstrated a significant increase in the numbers of T cells and total and activated eosinophils compared with airways from nonasthmatic subjects (p < 0.001). In the patients with asthma, the numbers of activated eosinophils but not T cells were significantly greater in airways with an internal perimeter less than 2 mm compared with those with an internal perimeter greater than 2 mm (p < 0.05). There were also significantly higher numbers of major basic protein-positive eosinophils, when expressed as a fraction of the alveolar wall tissue, in patients with asthma compared with control subjects (p < 0.05). In asthmatic airways with an internal perimeter of more than 2 mm, there was a greater number of activated eosinophils in the tissue between the epithelium and the smooth muscle compared with the tissue between the smooth muscle layer and lung parenchyma (p < 0.05). In contrast, there was a greater number of total eosinophils in the outer airway layer compared with the inner airway layer (p < 0.05). These results show that there is a similar but more severe inflammatory process present in the peripheral compared with the central airways of patients with asthma, which is consistent with the fact that the smaller airways are a major site of obstruction in asthma.

Functional human corneal equivalents constructed from cell lines

Human corneal equivalents comprising the three main layers of the cornea (epithelium, stroma, and endothelium) were constructed. Each cellular layer was fabricated from immortalized human corneal cells that were screened for use on the basis of morphological, biochemical, and electrophysiological similarity to their natural counterparts. The resulting corneal equivalents mimicked human corneas in key physical and physiological functions, including morphology, biochemical marker expression, transparency, ion and fluid transport, and gene expression. Morphological and functional equivalents to human corneas that can be produced in vitro have immediate applications in toxicity and drug efficacy testing, and form the basis for future development of implantable tissues.

Nephrogenic diabetes insipidus in mice lacking aquaporin-3 water channels

Aquaporin-3 (AQP3) is a water channel expressed at the basolateral plasma membrane of kidney collecting-duct epithelial cells. The mouse AQP3 cDNA was isolated and encodes a 292-amino acid water/glycerol-transporting glycoprotein expressed in kidney, large airways, eye, urinary bladder, skin, and gastrointestinal tract. The mouse AQP3 gene was analyzed, and AQP3 null mice were generated by targeted gene disruption. The growth and phenotype of AQP3 null mice were grossly normal except for polyuria. AQP3 deletion had little effect on AQP1 or AQP4 protein expression but decreased AQP2 protein expression particularly in renal cortex. Fluid consumption in AQP3 null mice was more than 10-fold greater than that in wild-type litter mates, and urine osmolality (<275 milliosmol) was much lower than in wild-type mice (>1,200 milliosmol). After 1-desamino-8-d-arginine-vasopressin administration or water deprivation, the AQP3 null mice were able to concentrate their urine partially to approximately 30% of that in wild-type mice. Osmotic water permeability of cortical collecting-duct basolateral membrane, measured by a spatial filtering optics method, was >3-fold reduced by AQP3 deletion. To test the hypothesis that the residual concentrating ability of AQP3 null mice was due to the inner medullary collecting-duct water channel AQP4, AQP3/AQP4 double-knockout mice were generated. The double-knockout mice had greater impairment of urinary-concentrating ability than did the AQP3 single-knockout mice. Our findings establish a form of nephrogenic diabetes insipidus produced by impaired water permeability in collecting-duct basolateral membrane. Basolateral membrane aquaporins may thus provide blood-accessible targets for drug discovery of aquaretic inhibitors.

First-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance therapy for patients with advanced EGFR mutation-positive lung adenocarcinoma (CONVINCE): a phase 3, open-label, randomized study

BACKGROUND

Icotinib has been previously shown to be non-inferior to gefitinib in non-selected advanced non-small-cell lung cancer patients when given as second- or further-line treatment. In this open-label, randomized, phase 3 CONVINCE trial, we assessed the efficacy and safety of first-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance in lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation.

PATIENTS AND METHODS

Eligible participants were adults with stage IIIB/IV lung adenocarcinoma and exon 19/21 EGFR mutations. Participants were randomly allocated (1 : 1) to receive oral icotinib or 3-week cycle of cisplatin plus pemetrexed for up to four cycles; non-progressive patients after four cycles were maintained with pemetrexed until disease progression or intolerable toxicity. The primary end point was progression-free survival (PFS) assessed by independent response evaluation committee. Other end points included overall survival (OS) and safety.

RESULTS

Between January 2013 and August 2014, 296 patients were randomized, and 285 patients were treated (148 to icotinib, 137 to chemotherapy). Independent response evaluation committee-assessed PFS was significantly longer in the icotinib group (11.2 versus 7.9 months; hazard ratio, 0.61, 95% confidence interval 0.43-0.87; P = 0.006). No significant difference for OS was observed between treatments in the overall population or in EGFR-mutated subgroups (exon 19 Del/21 L858R). The most common grade 3 or 4 adverse events (AEs) in the icotinib group were rash (14.8%) and diarrhea (7.4%), compared with nausea (45.9%), vomiting (29.2%), and neutropenia (10.9%) in the chemotherapy group. AEs (79.1% versus 94.2%; P < 0.001) and treatment-related AEs (54.1% versus 90.5%; P < 0.001) were significantly fewer in the icotinib group than in the chemotherapy group.

CONCLUSIONS

First-line icotinib significantly improves PFS of advanced lung adenocarcinoma patients with EGFR mutation with a tolerable and manageable safety profile. Icotinib should be considered as a first-line treatment for this patient population.

Lung fluid transport in aquaporin-5 knockout mice

The mammalian lung expresses water channel aquaporin-1 (AQP1) in microvascular endothelia, AQP4 in airway epithelia, and AQP5 at the apical plasma membrane in type I cells of alveolar epithelia. We previously studied the role of AQP1 and AQP4 in lung fluid transport using knockout mice. Here, we examined the role of AQP5 using AQP5 knockout mice, which were recently shown to manifest defective saliva secretion. AQP5 deletion did not affect lung morphology at the light microscopic level, nor did it affect the distribution or expression of aquaporins 1, 3, or 4. Airspace-capillary osmotic water permeability (P(f)) was measured in isolated perfused lungs by pleural surface fluorescence and gravimetric methods. P(f) was reduced 10-fold by AQP5 deletion and was further reduced by 2- to 3-fold in AQP1/AQP5 double-knockout mice. Hydrostatic lung edema in response to acute increases in pulmonary artery pressure was not affected by AQP5 deletion. Active alveolar fluid absorption was measured in an in situ lung model from the increase in concentration of a volume marker in an isosmolar alveolar instillate. Interestingly, fluid absorption did not differ in litter-matched AQP5 knockout mice, nor was there an effect of AQP5 deletion when fluid absorption was maximally stimulated by pretreatment of mice with keratinocyte growth factor. These results indicate that AQP5 is responsible for the majority of water transport across the apical membrane of type I alveolar epithelial cells. The unimpaired alveolar fluid clearance in AQP5-null mice indicates that high alveolar water permeability is not required for active, near-isosmolar fluid transport.

Ionic basis of the electrophysiological actions of adenosine on cardiomyocytes

The purpose of this review is to examine the role of the extracellular A1-adenosine (Ado) receptor in modulating membrane potential and currents in cardiac cells. The cellular electrophysiological effects of adenosine are both cell type- and species-dependent. In supraventricular tissues (SA, AV node, and atrium) of all species studied, the "direct" cAMP-independent activation of the inwardly rectifying K+ current IKAdo seems to be the most important action of adenosine. This current is activated by both adenosine and acetylcholine and flows through K+ channels with unitary slope conductance of about 45 pS and an open time constant of 1.4 ms. The density of K(+)-ACh,Ado channels is much less in ventricular than in atrial myocytes, and thus adenosine has little or no effect on the ventricular action potential. In atrial myocytes adenosine has a small inhibitory effect on basal L-type calcium current (ICa,L), but no effect on T-type calcium current (ICa,T). In ventricular myocytes, adenosine does not inhibit ICa,L (except ferret), ICa,T, or the sodium inward current INa. Adenosine has recently been shown to activate IKATP in ventricular membrane patches, but the relevance of this finding remains to be defined. Irrespective of cell type and species, adenosine inhibits membrane currents that are stimulated by beta-adrenergic agonists and other agents known to stimulate the activity of the enzyme adenylyl cyclase. This indirect cAMP-dependent mechanism of action has been shown to be responsible for the inhibition by adenosine of isoproterenol-stimulated ICa,L, delayed rectifier K+ current (IK), chloride current (ICl), the transient inward current ITi, and the pacemaker current IF. The importance of the actions of adenosine on membrane currents in modulation of atrial, ventricular, sinoatrial, and atrioventricular nodal function are discussed. Likewise, the antiarrhythmic and proarrhythmic actions of adenosine are discussed and the clinical implications of these actions are noted.

A precision measurement of the mass of the top quark

The standard model of particle physics contains parameters--such as particle masses--whose origins are still unknown and which cannot be predicted, but whose values are constrained through their interactions. In particular, the masses of the top quark (M(t)) and W boson (M(W)) constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. A precise measurement of M(t) can therefore indicate where to look for the Higgs, and indeed whether the hypothesis of a standard model Higgs is consistent with experimental data. As top quarks are produced in pairs and decay in only about 10(-24) s into various final states, reconstructing their masses from their decay products is very challenging. Here we report a technique that extracts more information from each top-quark event and yields a greatly improved precision (of +/- 5.3 GeV/c2) when compared to previous measurements. When our new result is combined with our published measurement in a complementary decay mode and with the only other measurements available, the new world average for M(t) becomes 178.0 +/- 4.3 GeV/c2. As a result, the most likely Higgs mass increases from the experimentally excluded value of 96 to 117 GeV/c2, which is beyond current experimental sensitivity. The upper limit on the Higgs mass at the 95% confidence level is raised from 219 to 251 GeV/c2.

Lung fluid transport in aquaporin-1 and aquaporin-4 knockout mice

The mammalian lung expresses water channel aquaporin-1 (AQP1) in microvascular endothelia and aquaporin-4 (AQP4) in airway epithelia. To test whether these water channels facilitate fluid movement between airspace, interstitial, and capillary compartments, we measured passive and active fluid transport in AQP1 and AQP4 knockout mice. Airspace-capillary osmotic water permeability (Pf) was measured in isolated perfused lungs by a pleural surface fluorescence method. Pf was remarkably reduced in AQP1 (-/-) mice (measured in cm/s x 0.001, SE, n = 5-10: 17 +/- 2 [+/+]; 6.6 +/- 0.6 AQP1 [+/-]; 1.7 +/- 0.3 AQP1 [-/-]; 12 +/- 1 AQP4 [-/-]). Microvascular endothelial water permeability, measured by a related pleural surface fluorescence method in which the airspace was filled with inert perfluorocarbon, was reduced more than 10-fold in AQP1 (-/-) vs. (+/+) mice. Hydrostatically induced lung interstitial and alveolar edema was measured by a gravimetric method and by direct measurement of extravascular lung water. Both approaches indicated a more than twofold reduction in lung water accumulation in AQP1 (-/-) vs. (+/+) mice in response to a 5- to 10-cm H2O increase in pulmonary artery pressure for five minutes. Active, near-isosmolar alveolar fluid absorption (Jv) was measured in in situ perfused lungs using 125I-albumin as an airspace fluid volume marker. Jv (measured in percent fluid uptake at 30 min, n = 5) in (+/+) mice was 6.0 +/- 0.6 (37 degrees C), increased to 16 +/- 1 by beta-agonists, and inhibited to less than 2.0 by amiloride, ouabain, or cooling to 23 degrees C. Jv (with isoproterenol) was not affected by aquaporin deletion (18.9 +/- 2.2 [+/+]; 16.4 +/- 1.5 AQP1 [-/-]; 16.3 +/- 1.7 AQP4 [-/-]). These results indicate that osmotically driven water transport across microvessels in adult lung occurs by a transcellular route through AQP1 water channels and that the microvascular endothelium is a significant barrier for airspace-capillary osmotic water transport. AQP1 facilitates hydrostatically driven lung edema but is not required for active near-isosmolar absorption of alveolar fluid.

The prognostic nutritional index is a predictive indicator of prognosis and postoperative complications in gastric cancer: A meta-analysis

BACKGROUND

The clinical value of the prognostic nutritional index (PNI) in gastric cancer (GC) remains controversial. Therefore, we performed the meta-analysis to determine the prognostic and clinicopathological values of PNI in patients with GC.

METHODS

A literature search was performed in the PubMed, Embase, and Web of Science databases. Hazard ratios (HRs) and odds ratios (ORs) were extracted to estimate the association of PNI with survival and clinicopathological characteristics, respectively.

RESULTS

Ten studies involving 3396 patients with GC were analyzed. The pooled results indicated that a low PNI was a significant predictor of poor overall survival (OS) (HR = 1.89, 95% confidence interval [CI] = 1.67-2.13, P < 0.01) and postoperative complications (OR = 1.74, 95% CI = 1.41-2.16, P < 0.01). In the subgroup analysis, a low PNI was significantly associated with poor OS in patients with GC at stage I, II and III, but not at stage IV (HR = 1.14, 95% CI = 0.84-1.55, P = 0.40). Moreover, a low PNI was significantly associated with more advanced tumor features, such as older age, deeper depth of tumor, positive lymph node metastasis, more advanced TNM stages, and positive vessel and lymphatic invasion.

CONCLUSION

PNI was a predictive indicator of survival and postoperative complications, and was associated with clinicopathological features in GC patients. However, a low PNI was not significantly associated with poor OS in patients with GC at stage IV.

A three-dimensional model of lanosterol 14alpha-demethylase of Candida albicans and its interaction with azole antifungals

The three-dimensional structure of lanosterol 14alpha-demethylase (P450(14DM), CYP51) of Candida albicans was modeled on the basis of crystallographic coordinates of four prokaryotic P450s: P450BM3, P450cam, P450terp, and P450eryF. The P450(14DM) sequence was aligned to those of known proteins using a knowledge-based alignment method. The main chain coordinates of the core regions were transferred directly from the corresponding coordinates of P450BM3. The side chain conformations of the core regions were determined by the conformations of the equivalent residues with the highest homologous scores in four crystal structures. The model was then refined using molecular mechanics and molecular dynamics. The reliability of the resulting model was assessed by Ramachandran plots, Profile-3D, hydropathy plot analysis, and by analyzing the consistency of the model with the experimental data. The structurally and functionally important residues such as the heme binding residues, the residues interacting with redox-partner protein and/or involved in electron transfer, the residues lining substrate access channel, and the substrate binding residues were identified from the model. These residues are candidates for further site-directed mutagenesis and site-specific antipeptide antibody binding experiments. The active analogue approach was employed to search the pharmacophoric conformations for 14 azole antifungals. The resulting bioactive conformations were docked into the active site of lanosterol 14alpha-demethylase of Candida albicans. All 14 azole antifungals are shown to have a similar docking mode in the active site. The halogenated phenyl group of azole inhibitors is deep in the same hydrophobic binding cleft as the 17-alkyl chain of substrate. The pi-pi stacking interaction might exist between halogenated phenyl ring of inhibitors and the aromatic ring of residue Y132. The long side chains of some inhibitors such as itraconazole and ketoconazole surpass the active site and interact with the residues in the substrate access channel. To compare with mammalian enzymes, structurally selective residues of the active site of fungal lanosterol 14alpha-demethylase are distributed in the C terminus of F helix, beta6-1 sheet and beta6-2 sheet.

Aquaporin-5 dependent fluid secretion in airway submucosal glands

Fluid and macromolecule secretion by submucosal glands in mammalian airways is believed to play an important role in airway defense and surface liquid homeostasis and in the pathogenesis of cystic fibrosis. Immunocytochemistry revealed strong expression of aquaporin water channel AQP5 at the luminal membrane of serous epithelial cells in submucosal glands throughout the mouse nasopharynx and upper airways and AQP4 at the contralateral basolateral membrane in some glands. Novel methods were applied to measure secretion rates and composition of gland fluid in wild type mice and knockout mice lacking AQP4 or AQP5. In mice breathing through a tracheotomy, total gland fluid output was measured from the dilution of a volume marker present in the fluid-filled nasopharynx and upper trachea. Pilocarpine-stimulated fluid secretion was 4.3 +/- 0.4 microl/min in wild type mice, 4.9 +/- 0.9 microl/min in AQP4 null mice, and 1.9 +/- 0.3 microl/min in AQP5 null mice (p < 0.001). Similar results were obtained when secreted fluid was collected in the oil-filled nasopharyngeal cavity. Real-time video imaging of fluid droplets secreted from individual submucosal glands near the larynx in living mice showed a 57 +/- 4% reduced fluid secretion rate in AQP5 null mice. Analysis of secreted fluid showed a 2.3 +/- 0.2-fold increase in total protein in AQP5 null mice and a smaller increase in [Cl(-)], suggesting intact protein and salt secretion across a relatively water impermeable epithelial barrier. Submucosal gland morphology and density did not differ significantly in wild type versus AQP5 null mice. These results indicate that AQP5 facilitates fluid secretion in submucosal glands and that the luminal membrane of gland epithelial cells is the rate-limiting barrier to water movement. Modulation of gland AQP5 expression or function might provide a novel approach to treat hyperviscous gland secretions in cystic fibrosis and excessive fluid secretions in infectious or allergic bronchitis/rhinitis.

Roles of hydrogen peroxide in thyroid physiology and disease

CONTEXT

The long-lived thyroid cell generates, for the synthesis of thyroid hormones, important amounts of H2O2 that are toxic in other cell types. This review analyzes the protection mechanisms of the cell and the pathological consequences of disorders of this system.

EVIDENCE ACQUISITION

The literature on H2O2 generation and disposal, thyroid hormone synthesis, and their control in the human thyroid is analyzed.

EVIDENCE SYNTHESIS

In humans, H2O2 production by dual-oxidases and consequently thyroid hormone synthesis by thyroperoxidase are controlled by the phospholipase C-Ca2+-diacylglycerol arm of TSH receptor action. H2O2 in various cell types, and presumably in thyroid cells, is a signal, a mitogen, a mutagen, a carcinogen, and a killer. The various protection mechanisms of the thyroid cell against H2O2 are analyzed. They include the separation of the generating enzymes (dual-oxidases), their coupling to thyroperoxidase in a proposed complex, the thyroxisome, and H2O2 degradation systems.

CONCLUSIONS

It is proposed that various pathologies can be explained, at least in part, by overproduction and lack of degradation of H2O2 (tumorigenesis, myxedematous cretinism, and thyroiditis) and by failure of the H2O2 generation or its positive control system (congenital hypothyroidism).

Cellular profile and cytokine production at prosthetic interfaces. Study of tissues retrieved from revised hip and knee replacements

The tissues surrounding 65 cemented and 36 cementless total joint replacements undergoing revision were characterised for cell types by immunohistochemistry and for cytokine expression by in situ hybridisation. We identified three distinct groups of revised implants: loose implants with ballooning radiological osteolysis, loose implants without osteolysis, and well-fixed implants. In the cemented series, osteolysis was associated with increased numbers of macrophages (p = 0.0006), T-lymphocyte subgroups (p = 0.03) and IL-1 (p = 0.02) and IL-6 (p = 0.0001) expression, and in the cementless series with increased numbers of T-lymphocyte subgroups (p = 0.005) and increased TNF alpha expression (p = 0.04). For cemented implants, the histological, histochemical and cytokine profiles of the interface correlated with the clinical and radiological grade of loosening and osteolysis. Our findings suggest that there are different biological mechanisms of loosening and osteolysis for cemented and cementless implants. T-lymphocyte modulation of macrophage function may be an important interaction at prosthetic interfaces.

Noninvasive in vivo fluorescence measurement of airway-surface liquid depth, salt concentration, and pH

The concentration of salt in the thin layer of fluid at the surface of large airways, the airway-surface liquid (ASL), is believed to be of central importance in airway physiology and in the pathophysiology of cystic fibrosis. Invasive sampling methods have yielded a wide range of ASL [NaCl] from 40 to 180 mM. We have developed novel fluorescent probes and microscopy methods to measure ASL thickness, salt concentration, and pH quantitatively in cell-culture models and in the trachea in vivo. By rapid z-scanning confocal microscopy, ASL thickness was 21 +/- 4 microm in well-differentiated cultures of bovine tracheal epithelial cells grown on porous supports at an air-liquid interface. By ratio imaging fluorescence microscopy using sodium, chloride, and pH-sensitive fluorescent indicators, ASL [Na+] was 97 +/- 5 mM, [Cl-] was 118 +/- 3 mM, and pH was 6.94 +/- 0.03. In anesthetized mice in which a transparent window was created in the trachea, ASL thickness was 45 +/- 5 microm, [Na+] was 115 +/- 4 mM, [Cl-] was 140 +/- 5 mM, and pH was 6.95 +/- 0.05. Similar ASL tonicity and pH were found in cystic fibrosis (CFTR-null) mice. In freshly harvested human bronchi, ASL thickness was 55 +/- 5 microm, [Na+] was 103 +/- 3 mM, [Cl-] was 92 +/- 4 mM, and pH was 6.78 +/- 0.2. These results establish by a noninvasive approach the key properties of the ASL and provide direct evidence that the ASL is approximately isotonic and not saltier in cystic fibrosis.

MicroRNA-335 acts as a metastasis suppressor in gastric cancer by targeting Bcl-w and specificity protein 1

Aberrant expression of miR-335 has been frequently reported in cancer studies, suggesting that there is a close correlation between miR-335 and cancer during its development, progression, metastasis and prognosis. The expression of miR-335 in gastric cancer and its effects are not known. Relative expression of miR-335 in 4 gastric cancer cell lines and in 70 gastric cancer tissues was confirmed by real-time quantitative reverse transcriptase-PCR compared with controls. Transwell cell migration and Matrigel invasion assay in vitro and metastasis formation assay in vivo were used to examine the effects of miR-335 expression on gastric cancer cell invasion and metastasis. The effect of miR-335 expression on gastric cancer cell proliferation was estimated by the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Luciferase reporter assay and western blot were used to examine the potential target genes and related pathways. Gene silencing with small-interfering RNA was used to examine the effects of target genes on gastric cancer cell invasion. miR-335 was dramatically downregulated in gastric cancer cell lines than in the normal gastric cell line GES-1. Low expression of miR-335 was significantly associated with lymph-node metastasis, poor pT stage, poor pN stage and invasion of lymphatic vessels. Overexpression of miR-335 suppressed gastric cancer cell invasion and metastasis in vitro and in vivo, but has no significant effects on cell proliferation. Furthermore, miR-335 might suppress gastric cancer invasion and metastasis by targeting Bcl-w and specificity protein 1 (SP1). Taken together, our results provide evidence that miR-335 might function as a metastasis suppressor in gastric cancer by targeting SP1 directly and indirectly through the Bcl-w-induced phosphoinositide 3-kinase-Akt-Sp1 pathway. miR-335 showing altered expression at different stages of gastric cancer could be a target for gastric cancer therapies and could be further developed as a potential prognostic factor.

Favorable response to human adipose tissue-derived mesenchymal stem cells in steroid-refractory acute graft-versus-host disease

There is no consistently effective therapy for patients with steroid-refractory acute graft-versus-host disease (GVHD). Various alternative approaches have been tested, including antithymocyte globulin, mycophenolate mofetil (MMF), pentostatin, and monoclonal antibodies; however, they have only been modestly successful. The purpose of our study was to evaluate the efficacy of human adipose-tissue-derived mesenchymal stem cells (AMSC) as salvage therapy for steroid-refractory acute GVHD. Six patients with steroid-refractory grades III-IV acute GVHD received IV infusions of AMSC. The AMSC dose was 1.0x10(6)/kg. No side effects were noted after the AMSC infusions. Five patients were treated once and one patient twice. Two patients received AMSC from haplo-identical family donors and four from unrelated mismatched donors. Acute GVHD disappeared completely in five of six patients, four of whom are alive after a median follow-up of 40 months (range, 18-90 months) after the initiation of AMSC therapy. All four surviving patients are in good clinical condition and in remission of their hematological malignancy. Two patients died-one with no obvious response to AMSC died of multiorgan failure and one a relapse of leukemia. These results suggested that AMSC is a promising treatment for severe steroid-resistant acute GVHD.

Plasma sex steroid hormones and risk of developing type 2 diabetes in women: a prospective study

AIMS/HYPOTHESIS

Prospective data directly investigating the role of endogenous sex hormones in diabetes risk have been scant, particularly in women. We aimed to examine comprehensively plasma sex hormones in connection with risk of developing type 2 diabetes in postmenopausal women.

METHODS

We conducted a prospective, nested case-control study of plasma oestradiol, testosterone and dehydroepiandrosterone sulfate and risk of type 2 diabetes in a cohort of women health professionals with a mean age of 60.3 and 12.2 years since menopause. Among women not using hormone therapy and free of baseline cardiovascular disease, cancer and diabetes, 359 incident cases of type 2 diabetes were matched with 359 controls during an average follow-up of 10 years.

RESULTS

Oestradiol and testosterone were each strongly and positively associated with risk of type 2 diabetes. After adjustment for BMI, family history, lifestyle and reproductive variables, the multivariable relative risks (95% CI) comparing the highest vs lowest quintile were 12.6 (2.83-56.3) for total oestradiol (p = 0.002 for trend), 13.1 (4.18-40.8) for free oestradiol (p < 0.001 for trend), 4.15 (1.21-14.2) for total testosterone (p = 0.019 for trend) and 14.8 (4.44-49.2) for free testosterone (p < 0.001 for trend). These associations remained robust after adjusting and accounting for other metabolic syndrome components and baseline HbA(1c) levels.

CONCLUSIONS/INTERPRETATION

In postmenopausal women, higher plasma levels of oestradiol and testosterone were strongly and prospectively related to increased risk of developing type 2 diabetes. These prospective data indicate that endogenous levels of sex hormones may play important roles in the pathogenesis of type 2 diabetes. ClinicalTrials.gov ID no.: NCT00000479.

Effects of oral magnesium supplementation on glycaemic control in Type 2 diabetes: a meta-analysis of randomized double-blind controlled trials

AIMS

The aim of this study was to assess the evidence on the effect of oral magnesium supplementation on glycaemic control in patients with Type 2 diabetes.

METHODS

We searched the electronic databases of medline, embase and the Cochrane Controlled Trials Register up to January 2005. We identified nine randomized double-blind controlled trials with a total of 370 patients with Type 2 diabetes and of duration 4-16 weeks. The median dose of oral magnesium supplementation was 15 mmol/day (360 mg/day) in the treatment groups. The primary outcome was glycaemic control, as measured by glycated haemoglobin (HbA(1c)) or fasting blood glucose levels; the secondary outcomes included body mass index, blood pressure (BP) and lipids. Using a random-effects model, we calculated the weighted mean differences (WMD) and 95% confidence interval (CI).

RESULTS

After a median duration of 12 weeks, the weighted mean post-intervention fasting glucose was significantly lower in the treatment groups compared with the placebo groups [-0.56 mmol/l (95% CI, -1.10 to -0.01); P for heterogeneity = 0.02]. The difference in post-intervention HbA(1c) between magnesium supplementation groups and control groups was not significant [-0.31% (95% CI, -0.81 to 0.19); P for heterogeneity = 0.10]. Neither systolic nor diastolic BP was significantly changed. Magnesium supplementation increased on high-density lipoprotein (HDL) cholesterol levels [0.08 mmol/l (95% CI, 0.03 to 0.14); P for heterogeneity = 0.36] but had no effect on total cholesterol, low-density lipoprotein (LDL) cholesterol and triglyceride.

CONCLUSIONS

Oral magnesium supplementation for 4-16 weeks may be effective in reducing plasma fasting glucose levels and raising HDL cholesterol in patients with Type 2 diabetes, although the long-term benefits and safety of magnesium treatment on glycaemic control remain to be determined.