HbA1c variability is associated with microalbuminuria development in type 2 diabetes: a 7-year prospective cohort study

AIMS/HYPOTHESIS

HbA(1c) variability has been shown to be an independent risk factor for nephropathy in patients with type 1 diabetes. In this study, we aimed to explore the association between HbA(1c) variability and microalbuminuria development in patients with type 2 diabetes. We also intended to test the applicability of serially measured HbA(1c) over 2 years for this risk assessment.

METHODS

Between 2003 and 2005, we recruited 821 middle-aged normoalbuminuric individuals with type 2 diabetes and followed them through to the end of 2010. The average follow-up time was 6.2 years. We defined microalbuminuria as a urine albumin to creatinine ratio of 30 mg/g (3.4 mg/mmol) or higher. HbA(1c) variability was calculated by the SD of serially measured HbA(1c). The Cox proportional hazards model was used to evaluate the association between HbA(1c) SD quartile and development of microalbuminuria.

RESULTS

The incidence of microalbuminuria for the overall population was 58.4, 58.6, 60.8 and 91.9 per 1,000 person-years for Q1- to Q4-adjusted HbA(1c) SD, respectively (p for trend = 0.042). Compared with patients in Q1, those in Q4 were about 37% more likely to develop microalbuminuria. The HR derived from a series of 2 year HbA(1c) measurements was similar to that from data collection for longer than 4 years.

CONCLUSIONS/INTERPRETATION

In addition to mean HbA(1c) values, HbA(1c) variability, even measured as early as 2 years, is independently associated with the development of microalbuminuria in patients with type 2 diabetes.

Human mesenchymal stromal cells are mechanosensitive to vibration stimuli

Low-magnitude high-frequency (LMHF) vibrations have the ability to stimulate bone formation and reduce bone loss. However, the anabolic mechanisms that are mediated by vibration in human bone cells at the cellular level remain unclear. We hypothesized that human mesenchymal stromal cells (hMSCs) display direct osteoblastic responses to LMHF vibration signals. Daily exposure to vibrations increased the proliferation of hMSCs, with the highest efficiency occurring at a peak acceleration of 0.3 g and vibrations at 30 to 40 Hz. Specifically, these conditions promoted osteoblast differentiation through an increase in alkaline phosphatase activity and in vitro matrix mineralization. The effect of vibration on the expression of osteogenesis-related factors differed depending on culture method. hMSCs that underwent vibration in a monolayer culture did not exhibit any changes in the expressions of these genes, while cells in three-dimensional culture showed increased expression of type I collagen, osteoprotegerin, or VEGF, and VEGF induction appeared in 2 different hMSC lines. These results are among the first to demonstrate a dose-response effect upon LMHF stimulation, thereby demonstrating that hMSCs are mechanosensitive to LMHF vibration signals such that they could facilitate the osteogenic process.

MicroRNA-146a suppresses metastatic activity in brain metastasis

Primary lung tumors, breast tumors, and melanoma metastasize mainly in the brain where therapy is limited to surgery and radiation. To investigate the molecular basis of brain metastases, we isolated brain-trophic metastatic MDA-MB-435-LvBr2 (LvBr2) cells via left ventricle (LV) injection of MDA-MB-435 cells into immunodeficiency (NOD/SCID) mice. Whereas parent MDA-MB-435 cells displayed an elongated morphology, LvBr2 cells were round and displayed an aggregated distribution. LvBr2 cells expressed lower β-catenin levels and higher heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNPC) levels than parental cells. Since microRNAs are known to play an important role in cancer progression including metastasis, we screened microRNAs expressed specifically in brain metastases. MicroRNA-146a was almost undetectable in LvBr2 cells and highly expressed in the parental cells. Overexpression of miR-146a increased β-catenin expression and suppressed the migratory and invasive activity of LvBr2 cells. The miR-146a-elicited decrease in hnRNPC in turn lowered the expression of MMP-1, uPA, and uPAR and inhibited the migratory and invasive activity of LvBr2 cells. Taken together, our findings indicate that miR-146a is virtually absent from brain metastases and can suppress their metastatic potential including their migratory and invasive activities associated with upregulation of β-catenin and downregulation of hnRNPC.

Immunohistochemical changes of adenomyosis after heat therapy: comparison of radiofrequency myolysis and endoablation

PURPOSE

To check the pathologic changes of focal adenomyosis after heat therapy using radiofrequency and to evaluate which approach--endometrial ablation or direct heat therapy--is better for adenomyosis. To evaluate whether the timing of the procedure and the menstrual cycle are related to pathologic outcomes after heat therapy.

METHODS

This study included nine women who underwent total hysterectomy for adenomyosis (diameter, > or = 6 cm). Six fresh uteri were excised in the midline and subjected to radiofrequency heat therapy at the center of the adenomyomas (direct heat therapy) and three uteri were subjected to endometrial ablation. Thereafter, 1 cm(3) myometrial tissue was obtained at 1 cm, 2 cm, and 3 cm away from the endometrium. Tissue sections were stained with hematoxylin and eosin. Immunohistochemical analysis using antibodies against cytokerain-19 (CK-19), actin, and estrogen receptor/progesterone receptor (ER/PR) was performed to evaluate CK-19 (endometrial epithelium marker), actin (myometrial marker) and ER/PR (checking the state of the menstrual cycle), respectively.

RESULTS

After endometrial ablation, cauterized tissues were not noted 2 cm away from the endometrium. All tissues between the endometruim and center of adenomyosis were cauterized after direct heat therapy. During the uterine proliferative phase, unlike the secretory phase, subendometrial layers were cauterized 10 min after direct cauterization.

CONCLUSION

Direct heat therapy is more effective than endometrial ablation in adenomyosis, and heat is conducted effectively when the patients are in the proliferative phase.

Peroxisome proliferator-activated receptor-gamma expression in the lung tissue of obese rats

PURPOSE

Obesity is a risk factor for asthma and type II diabetes. Peroxisome proliferator- activated receptor (PPAR)-γ has been suggested to regulate inflammatory responses in diabetes and asthma. We investigated whether PPAR-α, PPAR-γ, adiponectin receptors (AdipoR1, AdipoR2), leptin, and tumor necrosis factor (TNF)-α are expressed in rat lung tissues and whether the expression differs between obese Otsuka Long-Evans Tokushima Fatty (OLETF) and lean Long Evans Tokushima Otsuka (LETO) rats.

MATERIALS AND METHODS

Obese and lean rats were given with a high fat diet or a 30% restricted diet for 32 weeks, and their blood glucose levels and weights were monitored. After 32 weeks, mRNA levels of PPAR-α, PPAR-γ, AdipoR1, AdipoR2, leptin, and TNF-α in lung tissues were measured using real time PCR.

RESULTS

PPAR-α, PPAR-γ, AdipoR1, AdipoR2, leptin, and TNF-α were expressed in both obese and lean rat lung tissues. Increased serum glucose levels on intraperitoneal glucose tolerance testing and a higher weight gain at 32 weeks were observed in OLETF control rats compared to OLETF diet restricted rats. PPAR-γ expression was markedly elevated in obese control and diet restricted rats compared to lean rats, although PPAR-γ expression in obese rats was not affected by diet restriction. Leptin was highly expressed in OLETF rats compared to LETO rats. TNF-α expression was enhanced in OLETF control rats compared LETO diet restricted rats, and decreased by diet restriction. PPAR-α, AdipoR1, and AdipoR2 expression were not significantly different between obese and lean rats.

CONCLUSION

PPAR-γ was highly expressed in the lung tissues of obese rats and may be a novel treatment target for regulating lung inflammation associated with obesity.

Osteogenic responses of human mesenchymal stromal cells to static stretch

Molecular signals driving the regenerative process in distraction osteogenesis (DO) involve a complex system of cellular behavior triggered by mechanical strain. However, it remains unclear how mesenchymal stromal cells (MSCs) adapt to osteogenic demands during DO. We hypothesized that human MSCs (hMSCs) modulate early osteogenic metabolism during exposure to static stretch. The proliferation of hMSCs was increased by static stretch, which, in turn, suppressed TGF-β1-mediated decreases in cell proliferation. The amount of stretching force applied had little effect on osteoblast differentiation of hMSCs induced by dexamethasone treatment. However, this strain induced sustained production of nitric oxide and vascular endothelial growth factor (VEGF), which are critical factors in angiogenesis, from differentiated hMSCs. Mechanical stretch involved ERK and p38 mitogen-activated protein kinase pathways, the selective inhibitors of which decreased static-stretch-induced VEGF production. These findings provide evidence that hMSCs act to facilitate early osteogenic metabolism during exposure to static stretch.

Cigarette smoking and proteinuria in Taiwanese men with Type 2 diabetes mellitus

AIMS

Cigarette smoking is a well-known risk factor associated with diabetic nephropathy. The objective of this study was to further investigate the dose-response effect of tobacco exposure on proteinuria in males with Type 2 diabetes.

METHODS

Five hundred and nine males with Type 2 diabetes were selected from a cohort participating in a glucose control study in Taiwan. Pack-years of cigarette smoking were calculated to define tobacco exposure. Proteinuria was identified if albumin-to-creatinine ratio was > or = 30 mg/g in at least two of three consecutive urine tests. Logistic regression and trend tests were used to delineate the association between smoking status and proteinuria.

RESULTS

Compared with non-smokers, those who had smoked 15-30 or more than 30 pack-years were respectively 2.78 (95% CI 1.34-5.76, P < 0.01) and 3.20 (95% CI 1.74-5.86, P < 0.001) times more likely to develop proteinuria. The dose-response effect of tobacco exposure on the development of proteinuria is highly significant in all subjects (P = 0.001) and in subgroups with relatively short duration of diabetes mellitus (P < 0.001), good blood pressure control (P = 0.001) and those of young age (P = 0.007).

CONCLUSIONS

The current study shows a clear dose-response effect of cigarette smoking on development of proteinuria in male Type 2 diabetic patients. These findings reinforce the urgent need to encourage diabetic patients to stop smoking regardless of age, duration of diabetes mellitus or status of blood pressure control.

FTY720, a sphingosine 1-phosphate receptor modulator, inhibits CD1d-restricted NKT cells by suppressing cytokine production but not migration

FTY720, a sphingosine 1-phosphate (S1P) receptor modulator, suppresses immune responses by inhibiting T-cell migration into target tissues; however, it does not alter T-cell functions. In this study, we investigated the biological effects of FTY720 on NKT cells. Unlike T cells, FTY720 suppressed the production of IL-4, IFN-gamma, IL-10, and IL-13 by NKT cells through the S1P1 receptor (S1P(1)). Moreover, FTY720 also inhibited the expression of T-bet and GATA-3 of NKT cells in the presence of TCR engagement. However, it did not inhibit NKT cell migration in vitro or in vivo. In a K/BxN serum transfer arthritis model, FTY720 suppressed arthritis in B6, but not in CD1d(-/-) mice. Moreover, the adoptive transfer of control NKT cells restored arthritis in CD1d(-/-) mice, whereas FTY720-pretreated NKT cells did not. The number of NKT cells in the joints of B6 mice given FTY720 was similar to that in the joints of untreated B6 mice, whereas the production of IL-4 and IFN-gamma was reduced in the FTY720-treated B6 mice. Taken together, these data show that FTY720 suppresses cytokine production in NKT cells through S1P(1), but not NKT cell migration. Thus, FTY720 may be useful in the treatment of NKT cell-promoted immune diseases.

Sewage sludge reduction and system optimization in a catalytic ozonation process

The main objective of this study was to suggest a feasible, effective process for the reduction of sewage sludge using ozone oxidation catalysed by metal ion. A series of lab-scale experiments was conducted to select a suitable catalyst and its proper dose to achieve optimum sludge reduction. Using a central composite design under response surface methodology (RSM), system optimization with respect to sludge reduction and cost-effectiveness was performed by varying the independent parameters: dosages of ozone and ions. Five metal ions, Mn2+, Fe2+, Zn2+, CU2+, and Al3+1, were tested, and the manganese ion showed the highest sludge reduction, as measured by a decrease in total suspended solids. The ozone/Mn combination achieved approximately twice as much sludge reduction as the ozonation alone. Furthermore, the Mn dose of 10 mg/g-TS (total solids) resulted in the highest sludge reduction efficiency among the different doses, which ranged from 0 to 20 mg-Mn/g-TS. The predicted efficiency of sewage sludge reduction using the RSM was found to agree well with the experimental results, and the statistical analyses predicted optimum ranges for the doses of ozone and Mn ions, taking into account the overall cost for sewage sludge treatment.

IL-17 stimulates the proliferation and differentiation of human mesenchymal stem cells: implications for bone remodeling

Interleukin-17 (IL-17) is a cytokine secreted primarily by T(H)-17 cells. Although IL-17 is primarily associated with the induction of tissue inflammation, the other biological roles of IL-17, including non-immune functions, have yet to be thoroughly explored. Here, we report that T-cell-produced IL-17 can induce proliferation of human bone marrow-derived mesenchymal stem cells (hMSCs) in a manner dependent on the generation of reactive oxygen species (ROS). Rac1 GTPase and NADPH oxidase 1 (Nox1) are activated by IL-17 to produce ROS, which in turn stimulates hMSC proliferation. The activation of the MEK-ERK pathway is also crucial for IL-17-dependent hMSC proliferation. TRAF6 and Act1 are required to activate Nox 1 and to phosphorylate MEK on IL-17 stimulation. Interestingly, IL-17 not only accelerates the proliferation of hMSCs, but also induces their migration, motility, and osteoblastic differentiation. Furthermore, IL-17 induces the expression of M-CSF and receptor activator of NF-kappaB ligand (RANKL) on hMSCs, thereby supporting osteoclastogenesis both in vivo and in vitro. On the basis of these results, we suggest that IL-17 can function as a signal to induce extensive bone turnover by regulating hMSC recruitment, proliferation, motility, and differentiation.

A MELAS syndrome family harboring two mutations in mitochondrial genome

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a genetically heterogeneous mitochondrial disorder with variable clinical symptoms. Here, from the sequencing of the entire mitochondrial genome, we report a Korean MELAS family harboring two homoplasmic missense mutations, which were reported 9957T>C (Phe251Leu) transition mutation in the cytochrome c oxidase subunit 3 (COX3) gene and a novel 13849A>C (Asn505His) transversion mutation in the NADH dehydrogenase subunit 5 (ND5) gene. Neither of these mutations was found in 205 normal controls. Both mutations were identified from the proband and his mother, but not his father. The patients showed cataract symptom in addition to MELAS phenotype. We believe that the 9957T>C mutation is pathogenic, however, the 13849A>C mutation is of unclear significance. It is likely that the 13849A>C mutation might function as the secondary mutation which increase the expressivity of overlapping phenotypes of MELAS and cataract. This study also demonstrates the importance of full sequencing of mtDNA for the molecular genetic understanding of mitochondrial disorders.

Distal hereditary motor neuropathy in Korean patients with a small heat shock protein 27 mutation

Distal hereditary motor neuropathy (dHMN) is a heterogeneous disorder characterized by degeneration of motor nerves in the absence of sensory abnormalities. Recently, mutations in the small heat shock protein 27 (HSP27) gene were found to cause dHMN type II or Charcot-Marie-Tooth disease type 2F (CMT2F). The authors studied 151 Korean axonal CMT or dHMN families, and found a large Korean dHMN type II family with the Ser135Phe mutation in HSP27. This mutation was inherited in an autosomal dominant manner, and was well associated with familial members with the dHMN phenotype. This mutation site is located in the alpha-crystallin domain and is highly conserved between different species. The frequency of this HSP27 mutation in Koreans was 0.6%. Magnetic resonance imaging analysis revealed that fatty infiltrations tended to progressively extend distal to proximal muscles in lower extremities. In addition, fatty infiltrations in thigh muscles progressed to affect posterior and anterior compartments but to lesser extents in medial compartment, which differs from CMT1A patients presenting with severe involvements of posterior and medial compartments but less involvement of anterior compartment. The authors describe the clinical and neuroimaging findings of the first Korean dHMN patients with the HSP27 Ser135Phe mutation. To our knowledge, this is the first report of the neuroimaging findings of dHMN type II.

Distal hereditary motor neuropathy in Korean patients with a small heat shock protein 27 mutation

Distal hereditary motor neuropathy (dHMN) is a heterogeneous disorder characterized by degeneration of motor nerves in the absence of sensory abnormalities. Recently, mutations in the small heat shock protein 27 (HSP27) gene were found to cause dHMN type II or Charcot-Marie-Tooth disease type 2F (CMT2F). The authors studied 151 Korean axonal CMT or dHMN families, and found a large Korean dHMN type II family with the Ser135Phe mutation in HSP27. This mutation was inherited in an autosomal dominant manner, and was well associated with familial members with the dHMN phenotype. This mutation site is located in the alpha-crystallin domain and is highly conserved between different species. The frequency of this HSP27 mutation in Koreans was 0.6%. Magnetic resonance imaging analysis revealed that fatty infiltrations tended to progressively extend distal to proximal muscles in lower extremities. In addition, fatty infiltrations in thigh muscles progressed to affect posterior and anterior compartments but to lesser extents in medial compartment, which differs from CMT1A patients presenting with severe involvements of posterior and medial compartments but less involvement of anterior compartment. The authors describe the clinical and neuroimaging findings of the first Korean dHMN patients with the HSP27 Ser135Phe mutation. To our knowledge, this is the first report of the neuroimaging findings of dHMN type II.

Enhanced bio-energy recovery in a two-stage hydrogen/methane fermentation process

A two-stage hydrogen/methane fermentation process has emerged as a feasible engineering system to recover bio-energy from wastewater. Hydrogen-producing bacteria (HPB) generate hydrogen from readily available carbohydrates, and organic acids produced during the hydrogen fermentation step can be degraded to generate methane in the following step. Three strong acids, HCl, H(2)SO(4), and HNO(3), were tested to determine the appropriate pre-treatment method for enhanced hydrogen production. The hydrogen production rates of 230, 290, and 20 L/kg(-glucose)/day was observed for the sludge treated with HCl, H(2)SO(4), and HNO(3), respectively, indicating that the acid pre-treatment using either HCl or H(2)SO(4) resulted in a significant increase in hydrogen production. The fluorescent in situ hybridization method indicated that the acid pre-treatment selectively enriched HPB including Clostridium sp. of cluster I from inoculum sludge. After hydrogen fermentation was terminated, the sludge was introduced to a methane fermentation reactor. This experiment showed methane production rates of 100, 30, and 13 L/kg(-glucose)/day for the sludge pre-treated with HCl, H(2)SO(4), and HNO(3), respectively, implying that both sulfate and nitrate inhibited the activity of methane-producing bacteria. Consequently, the acid pre-treatment might be a feasible option to enhance biogas recovery in the two-stage fermentation process, and HCl was selected as the optimal strong acid for the enrichment of HPB and the continuous production of methane.

Characteristics of felodipine-located poly(ε-caprolactone) microspheres

Felodipine-loaded poly (epsilon-caprolactone) (PCL) microspheres were prepared by two methods, the conventional emulsion solvent evapouration method and the quenching method. The aim of this work was to investigate the effects of process parameters such as emulsion type, drug loading, molecular-weight of the polymer, types of emulsion stabilizer and dispersed phase solvents, as well as preparation methods. The results show that, when conventional emulsion solvent evapouration method was used, the o/w-method produced smaller mean size and higher encapsulation efficiency compared with the o/o-method. The encapsulation efficiencies increased with an increase in the molecular weight and a decrease in crystallinity of PCL. The size of microspheres varied with the type of emulsion stabilizer used, smaller microspheres with PVA and narrow size distribution with Pol 237. The water solubility of the dispersed phase solvent was one of the critical factors in controlling the encapsulation efficiency and microsphere mean size. When water-soluble solvents such as acetonitrile and ethyl formate were used, the encapsulation efficiencies decreased due to higher evapouration rate. When quenching methods were used, in contrast to the conventional emulsion solvent evapouration method, very narrowly size-distributed but bigger microspheres were obtained.