Vitamin D and obesity

An inverse association between vitamin D status and obesity has been reported across diverse populations and age groups in humans. In animal model of diet-induced obesity, dysregulation of vitamin D metabolism has been observed. However, the causal relationship between vitamin D status and obesity is not conclusive. Several explanations, such as volumetric dilution, sequestration of vitamin D into adipose tissue, and limited sunlight exposure, have been suggested as the underlying mechanisms linking poor vitamin D status and obesity. Vitamin D can modulate adipose tissue biology, spanning from adipocyte differentiation to adipocyte apoptosis and energy metabolism, indicating its potential impact on adiposity. In this chapter, we will review the prevalence of vitamin D deficiency and determinants of vitamin D deficiency among different populations, as well as changes in vitamin D metabolism associated with obesity. Additionally, we will review vitamin D's regulation of adipogenesis and lipogenesis at the cellular level in order to gain a deeper understanding of the underlying mechanisms linking vitamin D levels and obesity.

1,25-dihydroxyvitamin D3 affects thapsigargin-induced endoplasmic reticulum stress in 3T3-L1 adipocytes

BACKGROUND/OBJECTIVES

Endoplasmic reticulum (ER) stress in adipose tissue causes an inflammatory response and leads to metabolic diseases. However, the association between vitamin D and adipose ER stress remains poorly understood. In this study, we investigated whether 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) alleviates ER stress in adipocytes.

MATERIALS/METHODS

3T3-L1 cells were treated with different concentrations (i.e., 10-100 nM) of 1,25(OH)2D3 after or during differentiation (i.e., on day 0-7, 3-7, or 7). They were then incubated with thapsigargin (TG, 500 nM) for an additional 24 h to induce ER stress. Next, we measured the mRNA and protein levels of genes involved in unfold protein response (UPR) and adipogenesis using real-time polymerase chain reaction and western blotting and quantified the secreted protein levels of pro-inflammatory cytokines. Finally, the mRNA levels of UPR pathway genes were measured in adipocytes transfected with siRNA-targeting Vdr.

RESULTS

Treatment with 1,25(OH)2D3 during various stages of adipocyte differentiation significantly inhibited ER stress induced by TG. In fully differentiated 3T3-L1 adipocytes, 1,25(OH)2D3 treatment suppressed mRNA levels of Ddit3, sXbp1, and Atf4 and decreased the secretion of monocyte chemoattractant protein-1, interleukin-6, and tumor necrosis factor-α. However, downregulation of the mRNA levels of Ddit3, sXbp1, and Atf4 following 1,25(OH)2D3 administration was not observed in Vdr-knockdown adipocytes. In addition, exposure of 3T3-L1 preadipocytes to 1,25(OH)2D3 inhibited transcription of Ddit3, sXbp1, Atf4, Bip, and Atf6 and reduced the p-alpha subunit of translation initiation factor 2 (eIF2α)/eIF2α and p-protein kinase RNA-like ER kinase (PERK)/PERK protein ratios. Furthermore, 1,25(OH)2D3 treatment before adipocyte differentiation reduced adipogenesis and the mRNA levels of adipogenic genes.

CONCLUSIONS

Our data suggest that 1,25(OH)2D3 prevents TG-induced ER stress and inflammatory responses in mature adipocytes by downregulating UPR signaling via binding with Vdr. In addition, the inhibition of adipogenesis by vitamin D may contribute to the reduction of ER stress in adipocytes.

Dysregulation of Lipid Droplet Protein Expression in Adipose Tissues and Association with Metabolic Risk Factors in Adult Females with Obesity and Type 2 Diabetes

BACKGROUND

Adipocyte dysregulation of lipid droplet (LD) metabolism caused by altered expression of LD proteins contributes to obesity-related metabolic diseases.

OBJECTIVES

We aimed to investigate whether expression levels of PLIN1, CIDEA, and CIDEC were altered in adipose tissues of women with obesity and type 2 diabetes and whether their alterations were associated with metabolic risk factors.

METHODS

Normal-weight (NW; 18.5 kg/m² < BMI ≤ 25 kg/m²; n = 43), nondiabetic obese (OB; BMI > 30 kg/m²; n = 38), and diabetic obese (OB/DM; BMI > 30 kg/m², fasting glucose ≥ 126 mg/dL, HbA1c ≥ 6.5%; n = 22) women were recruited. Metabolic parameters were measured, and expressions of PLIN1, CIDEA, CIDEC, and obesity-related genes were quantified in abdominal subcutaneous (SAT) and visceral adipose tissues (VAT). Effects of proinflammatory cytokines, endoplasmic reticulum (ER) stress inducers, and metabolic improvement agents on LD protein gene expressions were investigated in human adipocytes.

RESULTS

PLIN1, CIDEA, and CIDEC expressions were lower in SAT and higher in VAT in OB subjects relative to NW subjects; however, they were suppressed in both fat depots in OB/DM subjects relative to OB (P < 0.05). Across the entire cohort, whereas VAT PLIN1 (r = 0.349) and CIDEC expressions (r = 0.282) were positively associated with BMI (P < 0.05), SAT PLIN1 (r = -0.390) and CIDEA expressions (r = -0.565) were inversely associated. After adjustment for BMI, some or all of the adipose LD protein gene expressions were negatively associated with fasting glucose (r = -0.259 or higher) and triglyceride levels (r = -0.284 or higher) and positively associated with UCP1 expression (r = 0.353 or higher) (P < 0.05). In adipocytes, LD protein gene expressions were 55-70% downregulated by increased proinflammatory cytokines and ER stress but 2-4-fold upregulated by the metabolic improvement agents exendin-4 and dapagliflozin (P < 0.05).

CONCLUSIONS

The findings suggest that reduction of adipose LD protein expression is involved in the pathogenesis of metabolic disorders in women with obesity and type 2 diabetes and that increasing LD protein expression in adipocytes could control development of metabolic disorders.

Adipose tissue LECT2 expression is associated with obesity and insulin resistance in Korean women

OBJECTIVE

Leukocyte cell-derived chemotaxin 2 (LECT2) is an obesity-upregulated hepatokine inducing skeletal muscle insulin resistance. The study's aim was to explore whether LECT2 is expressed in human adipose tissue and whether the expression is dysregulated during obesity and associated with obesity-related metabolic disorders.

METHODS

This study measured metabolic parameters, serum LECT2, and expression of LECT2 and CD209, a gene encoding a putative receptor for LECT2, in abdominal subcutaneous and visceral adipose tissues in women with obesity (with or without type 2 diabetes) and women with normal weight. The expression/secretion of LECT2 and its putative effects were assessed in human adipocytes.

RESULTS

Adipose tissue LECT2 mRNA and serum LECT2 were higher in women with obesity and were significantly correlated with parameters related to insulin resistance. LECT2 was mainly expressed by adipocytes. Both LECT2 and CD209 expression was higher in adipocytes from women with obesity. Incubating adipocytes with substances mimicking the microenvironment of obesity adipose tissue increased LECT2 expression/secretion. LECT2 treatment of adipocytes suppressed insulin-stimulated Akt phosphorylation; it reduced adiponectin (ADIPOQ) and increased leptin (LEP) expression in a CD209-dependent manner.

CONCLUSIONS

This study demonstrates that LECT2 expression in adipose tissue is high in patients with obesity and associated with insulin resistance and suggests that adipocyte-derived LECT2 may contribute to adipose tissue dysfunction.

TRIB3 Is Highly Expressed in the Adipose Tissue of Obese Patients and Is Associated With Insulin Resistance

CONTEXT

The upregulation of TRIB3 (Tribbles homolog 3), a stress-inducible gene encoding a pseudokinase, has been implicated in the development of insulin resistance in the skeletal muscle and liver of patients with obesity and type 2 diabetes. However, there is little information regarding TRIB3 expression in human adipose tissue.

OBJECTIVE

To investigate whether TRIB3 expression is dysregulated in human adipose tissue in the context of obesity and type 2 diabetes and whether TRIB3 expression in adipose tissues is associated with insulin resistance.

METHODS

We measured metabolic parameters and TRIB3 expression in abdominal subcutaneous and visceral adipose tissue in obese (with or without type 2 diabetes) and normal-weight women. Regulation of TRIB3 expression was studied in human adipocytes.

RESULTS

TRIB3 expression in both fat depots was higher in patients with obesity and/or type 2 diabetes; in addition, the expression level was significantly associated with insulin resistance. Incubating adipocytes under conditions mimicking the microenvironment of obese adipose tissue, including increased endoplasmic reticulum (ER) stress, induced TRIB3 expression. In human adipocytes, the overexpression of TRIB3 impaired insulin-stimulated protein kinase B (AKT) phosphorylation and caused dysregulation of the transcription of genes encoding bioactive molecules released from adipocytes, such as proinflammatory cytokines, adiponectin, and leptin. Pioglitazone, an insulin-sensitizing agent, reduced both these effects of TRIB3 and the ER stressor-induced expression of TRB3.

CONCLUSION

Our data indicate that TRIB3 expression in adipose tissue is enhanced in patients with obesity and suggest that increased TRIB3 dysregulates adipocyte function, which may contribute to the development of insulin resistance.

Endoplasmic reticulum stress increases LECT2 expression via ATF4

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with obesity, insulin resistance, and endoplasmic reticulum (ER) stress. Elevated circulating levels of the hepatokine leukocyte cell-derived chemotaxin-2 (LECT2) have also been noted in NAFLD; however, the mechanism underlying this association is unclear. To investigate a possible link between ER stress/unfolded protein response (UPR) signaling and LECT2 secretion, HepG2 cells were incubated with ER stress inducers with or without an ER stress-reducing chemical chaperone. Additionally, UPR pathway genes were knocked down and overexpressed, and a ChIP assay was performed. In diet-induced obese mice, hepatic expression of LECT2 and activating transcription factor 4 (ATF4) was measured. In HepG2 cells, LECT2 expression was increased by ER stressors, an effect blocked by the chemical chaperone. Among UPR pathway proteins, only knockdown of ATF4 suppressed ER stress-induced LECT2 expression, while overexpression of ATF4 enhanced LECT2 expression. The ChIP assay revealed that ATF4 binds to three putative binding sites on the LECT2 promoter and binding is promoted by an ER stress inducer. In steatotic livers of obese mice, LECT2 and ATF4 expression was concomitantly elevated. Our data indicate that activation of ER stress/UPR signaling induces LECT2 expression in steatotic liver; specifically, ATF4 appears to mediate upregulation of LECT2 transcription.

Effects of in vitro vitamin D treatment on function of T cells and autophagy mechanisms in high-fat diet-induced obese mice

BACKGROUND/OBJECTIVES

Obesity is associated with the impaired regulation of T cells characterized by increased numbers of Th1 and Th17 cells and the dysregulation of vitamin D metabolism. Both obesity and vitamin D have been reported to affect autophagy; however, a limited number of studies have investigated the effects of vitamin D on T cell autophagy in obese mice. Therefore, we aimed to determine whether in vitro treatment with vitamin D affects the proliferation, function, and autophagy of T cells from obese and control mice.

MATERIALS/METHODS

Five-week-old male C57BL/6 mice were fed control or high-fat diets (10% or 45% kcal fat: CON or HFDs, respectively) for 12 weeks. Purified T cells were stimulated with anti-CD3 and anti-CD28 monoclonal antibodies and cultured with either 10 nM 1,25(OH)₂D₃ or 0.1% ethanol (vehicle control). The proliferative response; expression of CD25, Foxp3, RORγt, and autophagy-related proteins (LC3A/B, SQSTM1/P62, BECLIN-1, ATG12); and the production of interferon (IFN)-γ, interleukin (IL)-4, IL-17A, and IL-10 by T cells were measured.

RESULTS

Compared with the CON group, T cell proliferation tended to be lower, and the production of IFN-γ was higher in the HFD group. IL-17A production was reduced by 1,25(OH)2D₃ treatment in both groups. The LC3 II/I ratio was higher in the HFD group than the CON group, but P62 did not differ. We observed no effect of vitamin D treatment on T cell autophagy.

CONCLUSIONS

Our findings suggest that diet-induced obesity may impair the function and inhibit autophagy of T cells, possibly leading to the dysregulation of T cell homeostasis, which may be behind the aggravation of inflammation commonly observed in obesity.

Nutrient modulation of viral infection-implications for COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has put focus on the importance of a healthy immune system for recovery from infection and effective response to vaccination. Several nutrients have been under attention because their nutritional statuses showed associations with the incidence or severity of COVID-19 or because they affect several aspects of immune function. Nutritional status, immune function, and viral infection are closely interrelated. Undernutrition impairs immune function, which can lead to increased susceptibility to viral infection, while viral infection itself can result in changes in nutritional status. Here, we review the roles of vitamins A, C, D, and E, and zinc, iron, and selenium in immune function and viral infection and their relevance to COVID-19.

The Role of Vitamin D in Adipose Tissue Biology: Adipocyte Differentiation, Energy Metabolism, and Inflammation

Adipose tissue is composed of diverse cell types and plays a major role in energy homeostasis and inflammation at the local and systemic levels. Adipose tissue serves as the main site for vitamin D storage and is among the most important extraskeletal targets of vitamin D which can modulate multiple aspects of adipose tissue biology. Vitamin D may exert inhibitory or stimulatory effects on adipocyte differentiation depending on cell type, stage of differentiation, and the treatment time point. Moreover, vitamin D controls energy metabolism in adipose tissue by affecting fatty acid oxidation, expression of uncoupling proteins, insulin resistance, and adipokine production. Adipose tissue inflammation can have a significant impact on the metabolic disorders often associated with obesity, and vitamin D can modulate the inflammatory response of immune cells and adipocytes within the adipose tissue. This review discusses the role of adipose tissue in vitamin D metabolism, as well as the regulatory role of vitamin D in adipocyte differentiation, adipose tissue energy metabolism, and inflammation, thereby providing insights into the importance of vitamin D in adipose tissue biology.

Effects of high fat diet-induced obesity on vitamin D metabolism and tissue distribution in vitamin D deficient or supplemented mice

Background

Vitamin D deficiency has been often observed in obese persons. One of the mechanisms suggested for low vitamin D status in obesity was decreased bioavailability of vitamin D (VD) due to sequestration in adipose tissue. However, only few studies have investigated this mechanism via quantifying vitamin D levels from tissues from the obese.

Methods

Six-wk-old C57BL/6 mice were fed 10 or 45% kcal fat (CON or HFD) diets containing 50, 1000 or 25,000 IU vitamin D3/kg diet (LVd, CVd or HVd) for 13 wks. Serum 25-hydroxyvitamin D (25(OH)D) levels were determined by radioimmunoassay and liver and adipose tissue cholecalciferol (VD3) and 25-hydrocholecalciferol (25(OH)D3) levels were measured by LC-MS/MS. mRNA levels of jejunal Mttp, Cd36, Sr-b1, Npc1l1, and Abca1 and liver and adipose tissue 25-hydroxylases (Cyp2r1 and Cyp27a1) were determined by real-time PCR.

Results

Serum 25(OH)D levels were affected by dietary vitamin D content but differential effects were observed between HFD and CON groups. When vitamin D intake was at a supplementary level, the HFD-HVd group had lower serum 25(OH)D levels than the CON-HVd group, while there was no significant difference between the HFD and CON groups fed LVd or CVd. Total amount of VD3 in liver and adipose tissue were significantly higher in HFD-HVd group compared with the CON-HVd group. However, no difference in total amount of tissue VD3 was observed between the CON and HFD groups fed CVd. In jejunum, mRNA levels of Mttp and Abca1 were significantly higher in HFD groups than CON groups. There was no difference in mRNA levels of liver 25-hydroxylases by both dietary fat amount and vitamin D content.

Conclusion

A significant amount of VD3 seemed to be stored in the liver and adipose tissue when dietary vitamin D is at a supplementation level; thus excess body adiposity could contribute to relatively low serum 25(OH)D level when vitamin D was supplemented.

Effects of Vitamin D Supplementation on 1, 25-dihydroxyvitamin D Metabolism and Its Impact on Adipose Tissue Inflammation in Obese Mice (P24-004-19)

Objectives

Adipose tissue expresses CYP27B1 and VDR, suggesting local metabolism and function of 1,25-dihydroxyvitamin D (1,25(OH)2D) in adipose tissue. Obesity has been associated with dysregulation of 1,25(OH)2D levels. We investigated effects of vitamin D supplementation on 1,25(OH)2D metabolism and its impact in adipose tissue of obese mice.

Methods

Six-wk-old C57BL/6 mice were divided into 4 groups and fed experimental diets containing 10% or 45% kcal fat (CON or HFD) and differing in vitamin D content (1000 or 25,000 IU/kg of diet, DC or DS) for 13 wks. Serum 1,25(OH)2D and PTH levels were determined with radio- or enzyme-immunoassay. The mRNA levels of Cyp27b1, Cyp24a1, and Lrp2 in the kidney, and Cyp27b1, Vdr, and pro-inflammatory cytokines (Mcp-1, Rantes, Mip-1γ, Tnf-α, Il-6, Il-1β, and Ifn-γ) in the epididymal adipose tissue were determined by real-time PCR.

Results

Overall, serum 1,25(OH)2D levels were higher in DS groups compared with DC groups. When 1,25(OH)2D levels were compared between CON and HFD groups, differential pattern was observed depending on vitamin D levels in the diet. HFD-DC group showed higher serum 1,25(OH)2D and PTH levels compared with CON-DC group. However, in the DS groups, serum 1,25(OH)2D and PTH levels were not significantly affected by dietary fat amount. Renal Cyp24a1 mRNA levels, which could be up-regulated by dietary vitamin D, was higher in CON-DS group compared with CON-DC group. However, in the HFD groups, renal Cyp24a1 mRNA levels were similar in DC and DS groups. Mcp-1 and Rantes mRNA levels were higher in the HFD groups compared with CON groups, and their overall expression levels were down-regulated by vitamin D supplementation. Overall, mRNA levels of Il-6 and Il-1β were lower in the DS groups compared with DC groups.

Conclusions

Dietary vitamin D supplementation alleviated inflammatory responses in adipose tissue. Both 1,25(OH)2D in circulation and locally produced 1,25(OH)2D in adipose tissue might have contributed to the effect.

Funding Sources

Supported by the grant from the National Research Foundation (NRF) of Korea (NRF-2018R1D1A1B070491).

Effects of 1,25-dihydroxyvitamin D3 on Inflammatory Responses of Stromal Vascular Cells and Adipocytes from Control and Obese Mice (FS12-04-19)

Objectives

Several in vitro studies showed that 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) treatment could inhibit chronic inflammation in mouse or human adipocytes; however there have been a few in vivo studies. We investigated whether vitamin D supplementation affects subpopulation of immune cells in adipose tissue and the effects of in vitro 1,25(OH)2D3 treatment on pro-inflammatory cytokine secretion by stromal vascular cells (SVC) and adipocytes.

Methods

Five-wk old C57BL/6 N mice were divided into 4 groups and fed diets differ in fat amount (10 or 45% kcal fat: CON or HFD) and vitamin D content (1000 or 10,000 IU/kg of diet: DC, or DS) for 13 wks. Subpopulation of immune cells (macrophage, NK cell, CD 4 T cell, CD 8 T cell, B cell) from adipose tissue-derived SVC was determined by FACS analysis. Five-wk old C57BL/6 mice were fed control or HFD diets (10 or 60% kcal fat, CON or HFD) for 12 wks. Adipocytes and SVC, isolated from visceral adipose tissue, were cultured with or without 10 nM of 1,25(OH)2D3 for 48 h and stimulated with LPS during the last 24 h. Pro-inflammatory cytokines produced by SVC and adipocytes were measured by ELISA. The mRNA levels of Tlr2, Tlr4, Dusp1, and Dusp10 were determined in SVC by real-time PCR.

Results

The number of macrophages and NK cells within adipose tissue were higher in the HFD groups than CON groups. Dietary vitamin D did not alter the number of immune cells in adipose tissue. The production of IL-6 and MCP-1 from SVC and adipocytes were higher in the HFD groups compared with CON groups. In vitro 1,25(OH)2D3 treatment decreased IL-6, MCP-1, IL-1β production by SVC from HFD group and decreased IL-6 production by SVC from CON group. SVC Tlr2 mRNA levels, which were higher in the HFD group, decreased significantly by in vitro 1,25(OH)2D3 treatment. mRNA levels of Dusp1, which inhibits MAPK signaling, were increased by in vitro 1,25(OH)2D3 treatment. However, pro-inflammatory cytokine secretion from adipocytes was not affected by in vitro 1,25(OH)2D3 treatment.

Conclusions

Although vitamin D supplementation did not reduce macrophage and NK cell numbers in adipose tissue, 1,25(OH)2D3 seemed to decrease pro-inflammatory cytokine production from SVCs by regulating Tlr2 and Dusp1.

Funding Sources

Supported by the grant from the National Research Foundation (NRF) of Korea (NRF-2018R1D1A1B070491).

Tissue Distribution of Cholecalciferol and 25-hydroxycholecalciferol in Normal and Obese Mice Fed Different Levels of Vitamin D (P24-003-19)

Objectives

Vitamin D deficiency is often observed in obese person. One of the mechanisms suggested is the decreased bioavailability of vitamin D due to its deposition in adipose tissue. We investigated the effects of obesity on vitamin D distribution by measuring 25(OH)D levels in circulation and comparing vitamin D content in liver and adipose tissue from obese and control mice fed different levels of vitamin D.

Methods

Six-wk-old C57BL/6 mice were fed control or high fat (10 or 45% kcal fat, CON or HFD) diets containing different levels of vitamin D3 (1000, or 25,000 IU/kg of diet, CVd or HVd) for 13 wks. Serum 25-hydroxyvitamin D (25(OH)D) level was determined by radioimmunoassay. Vitamin D3 and 25(OH)D3 levels in the liver and epididymal adipose tissue (AT) were quantified by LC-MS/MS. mRNA levels of liver Cyp2r1 and Cyp27a1 were determined by real-time PCR.

Results

Overall, serum 25(OH)D levels were significantly higher in the HVd groups compared with CVd groups. There was no difference in serum 25(OH)D levels between CON-CVd and HFD-CVd groups. However, in the vitamin D supplemented groups, HFD-HVd group had significantly lower serum 25(OH)D levels (20% lower) than CON-HVd group. Vitamin D3 levels in the liver and AT were 55 and 100 times higher in the HVd groups (liver and AT: 719 and 318 ng/g tissue) compared with the CVd groups. 25(OH)D3 levels in the liver and AT were also 3.3 and 2.4 times higher in the HVd groups (liver and AT: 33.9 and 18.9 ng/g tissue) than those of the CVd groups. Total amount of vitamin D3 in the liver and AT were significantly higher in the HFD-HVd group (121 and 44% higher) compared with CON-HVd group. However, when mice were fed the control levels of vitamin D, dietary fat levels did not affect the vitamin D3 amount in the liver and AT. Liver Cyp2r1 and Cyp27a1 mRNA levels did not differ among groups.

Conclusions

When vitamin D intake was at a supplementation level, a significant amount of dietary vitamin D seemed to be stored in the liver and AT; thus excess body adiposity could contribute to lower serum 25(OH)D level. However, at a control level of vitamin D intake, obesity did not affect tissue vitamin D amount and serum 25(OH)D levels.

Funding Sources

Supported by the grant from the National Research Foundation (NRF) of Korea (NRF-2018R1D1A1B070491) and Research Grant from Research Affairs at Seoul National University.

Vitamin D supplementation partially affects colonic changes in dextran sulfate sodium-induced colitis obese mice but not lean mice

Inflammatory bowel disease (IBD) often accompanies vitamin D deficiency, and vitamin D supplementation ameliorates IBD symptoms in animal models and humans. Because altered vitamin D metabolism has been reported in obesity, we hypothesized that the effects of vitamin D on the development of IBD would be different between obese and control mice. Five-week-old male C57BL/6N mice were divided into 4 groups and fed a diet differing in fat content (10% or 45%, normal diet [ND] or high-fat diet [HFD]) and vitamin D content (1000 or 10 000 IU/kg of diet, vDC or vDS) for 14 weeks. At week 13, colitis was induced by administration of 2% dextran sodium sulfate for 7 days. Histology score tended to be lower in the HFD-vDS group than HFD-vDC group, but there was no effect of vitamin D on the ND group. Colonic Cldn1 and Cyp27b1 mRNA levels were higher in the HFD-vDS than HFD-vDC group, but these effects of vitamin D were not observed in the ND group. The serum 25-hydroxy vitamin D levels were negatively correlated with the histology score in the HFD group but not in the ND group. Overall, these results suggest that vitamin D supplementation partially prevents the histological damage of the colon in obese mice but not in control mice. This effect might be mediated by increased colonic Cyp27b1 levels, leading to upregulation of local 1,25-dihydroxy vitamin D production.

Effect of preoperative pregabalin on postoperative pain after gastrectomy

Background

Pregabalin has been studied as a single or multimodal analgesic drug for postoperative pain management in different types of surgeries. We evaluated the analgesic effect of 150 mg of pregabalin in resolving post-gastrectomy pain.

Methods

Forty-four patients were randomized into two groups: a pregabalin group that received oral pregabalin (150 mg) 2 h before anesthetic induction, and a control group that received placebo tablets at the same time. Data on postoperative pain intensity (visual analog scale [VAS], at 30 min, 2 h, 4 h, and 24 h), consumption of fentanyl in patient-controlled analgesia (PCA), and the proportion of patients requiring rescue analgesics at different time intervals (0-2 h, 2-4 h, and 4-24 h) were collected during the 24 h postoperative period.

Results

The VAS scores did not show significant differences at any time point and consumption of fentanyl in PCA and the proportion of patients requiring rescue analgesics did not differ between the two groups. The groups did not differ in the occurrence of dizziness, sedation, and dry mouth.

Conclusion

A preoperative 150 mg dose of pregabalin exerts no effect on acute pain after gastrectomy.

Differential effect of dietary vitamin D supplementation on natural killer cell activity in lean and obese mice

Vitamin D has an immunoregulatory effect on both innate and adaptive immunity. Contradictory results regarding vitamin D and natural killer (NK) cell functions have been reported with in vitro studies, but little is known about this in vivo. We investigated whether vitamin D levels (50, 1000 or 10,000 IU/kg of diet: DD, DC or DS) affect NK cell functions in mice fed a control or high-fat diet (10% or 45% kcal fat: CD or HFD) for 12 weeks. The splenic NK cell activity was significantly higher in the CD-DS group than the HFD-DS group, and the CD-DS group showed significantly higher NK cell activity compared with the CD-DD and CD-DC groups. However, no difference in NK cell activity was observed among the HFD groups fed different levels of vitamin D. The splenic population of NK cells was significantly higher in the CD-DS group than the HFD-DS group. There was no difference in the intracellular expression of IFN-γ and the surface expression of NKG2D and CD107a in NK cells by both dietary fat and vitamin D content. The splenic mRNA expression of Ifng and Ccl5 was significantly lower in the HFD groups compared with the CD groups, but there was no difference in the mRNA levels of Vdup1 and Vdr among the groups. Taken together, these results suggest that dietary vitamin D supplementation can modulate innate immunity by increasing NK activity in control mice but not in obese mice. This effect might be mediated through alternation of the splenic NK cell population.

Effects of mild calorie restriction on lipid metabolism and inflammation in liver and adipose tissue

Calorie restriction (CR) has been reported to improve lipid metabolism and to decrease inflammatory diseases. However, most existing CR models use 30-50% calorie reduction, which is hard to achieve in humans. We investigated the effects of mild CR on lipid metabolism and inflammatory responses. Male C57BL/6 mice were fed control diet (10% kcal fat, Control) or high fat diet (60% kcal fat, HFD) ad libitum or reduced amount of control diet to achieve 15% CR for 16 wks. Body weights, white adipose tissue weights, liver triacylglycerol levels, and serum fetuin-A levels were lower in CR than in the Control. Serum adiponectin levels were higher in CR and lower in HFD compared with the Control. Liver and adipose tissue Mcp-1 mRNA levels were significantly lower in CR compared with the Control. Adipose tissue mRNA levels of Mcp-1, Il-6, Tnf-α and Socs3 were significantly higher in HFD than in the Control and CR, and levels of these negatively correlated with serum adiponectin levels. CR group had the lowest leptin levels and the highest liver Lepr expression, and Lepr mRNA levels positively correlated with liver Socs3 mRNA levels. Our findings showed that mild CR lowered adiposity which resulted in higher adiponectin and lower fetuin-A levels, and might have contributed to alleviation of inflammatory status in the liver and adipose tissue. Furthermore, mild CR might have affected leptin sensitivity by up-regulating Lepr expression.

Hepatic iron storage is related to body adiposity and hepatic inflammation

Background

Obesity has been reported to be associated with iron deficiency. However, few studies have investigated iron status in low adiposity. To investigate whether body adiposity was associated with altered hepatic iron status, we compared liver iron levels and markers involved in inflammation and iron absorption in obese, control, and mildly calorie restricted mice.

Methods

Seven week old C57BL/6 mice were fed control (10% kcal fat, Control) or high fat (60% kcal fat, HFD) diets, or reduced amount of control diet to achieve 15% calorie restriction (CR) for 16 weeks. Hepatic non-heme iron content and ferritin protein level, and hematocrit and hemoglobin levels were determined to assess iron status. Hepatic expression of Mcp-1 and Tnf-α were measured as hepatic inflammatory markers. Hepatic hepcidin (Hamp) and Bmp6, and duodenal Dmt1, Dcyt1b, hephaestin (Heph) and ferroportin mRNA levels were measured as factors involved in regulation of iron absorption.

Results

Hepatic non-heme iron and ferritin protein levels were significantly higher in the CR group compared with the Control group, and significantly lower in the HFD group. These two iron status markers showed significantly negative correlations with the amount of white adipose tissue (r = -0.689 for hepatic non-heme iron and r = -0.740 for ferritin). Hepatic Mcp-1 and Tnf-α mRNA levels were significantly lower in the CR compared with the HFD (74 and 47% lower) and showed significantly negative correlations with hepatic non-heme iron levels (Mcp-1: r = -0.557, P < 0.05; Tnf-α: r = -0.464, P < 0.05). Hepatic Hamp mRNA levels were lower in the HFD and higher in the CR groups compared with the Control group, which could be a response to maintain iron homeostasis. Duodenal Dcyt1b mRNA levels were higher in the CR group compared with the HFD group and duodenal Heph mRNA levels were higher in the CR group than the Control group.

Conclusion

We showed that body adiposity was inversely correlated with liver iron status. Low inflammation levels in hepatic milieu and enhanced expression of duodenal oxidoreductases induced by calorie restriction could have contributed to higher iron status.

Chronic kidney disease and high eGFR according to body composition phenotype in adults with normal BMI

BACKGROUND AND AIMS

Body composition contributes to the risk of chronic kidney disease (CKD) and glomerular hyperfiltration. In adults with normal body mass index (BMI), the relationships of body composition with CKD and high estimated glomerular filtration rate (eGFR) are largely unknown.

METHODS AND RESULTS

We analyzed 10,734 adults from the Korean National Health and Nutrition Examination Survey (KNHANES), whose body mass index (BMI) was within the normal range (18.5-24.9 kg/m²). Body composition was categorized into four phenotypes (normal, sarcopenia alone, obesity alone, and sarcopenic obesity) based on appendicular lean mass index (ALMI) and total body fat percentage (TBF%) measured by dual-energy X-ray absorptiometry (DXA). We examined the relationship of CKD and high eGFR (eGFR ≥ 120 ml/min per 1.73 m²) with body composition phenotypes. Sarcopenia alone (14.3%), obesity alone (16.0%), and sarcopenic obesity (10.7%) were prevalent. The association between sarcopenia alone and eGFR was J-shaped, while that between sarcopenic obesity and eGFR was U-shaped. In multivariate logistic regression analysis compared with the normal phenotype, sarcopenic obesity had an elevated odds ratio (OR) for CKD (OR: 1.59, 95% CI: 1.16-2.19). Sarcopenia alone (OR: 1.87; 95% CI: 1.41-2.47) and sarcopenic obesity (OR: 2.37, 95% CI: 1.68-3.36) had elevated OR for high eGFR.

CONCLUSION

These findings suggest that decreased muscle mass and coexistence with excess adiposity show associations with CKD and high eGFR even in adults with normal BMI. Body composition measured by DXA could provide information on the relationship of body composition with CKD and high eGFR.

Latrophilin receptors: novel bronchodilator targets in asthma

Background

Asthma affects 300 million people worldwide. In asthma, the major cause of morbidity and mortality is acute airway narrowing, due to airway smooth muscle (ASM) hypercontraction, associated with airway remodelling. However, little is known about the transcriptional differences between healthy and asthmatic ASM cells.

Objectives

To investigate the transcriptional differences between asthmatic and healthy airway smooth muscle cells (ASMC) in culture and investigate the identified targets using in vitro and ex vivo techniques.

Methods

Human asthmatic and healthy ASMC grown in culture were run on Affymetrix_Hugene_1.0_ST microarrays. Identified candidates were confirmed by PCR, and immunohistochemistry. Functional analysis was conducted using in vitro ASMC proliferation, attachment and contraction assays and ex vivo contraction of mouse airways.

Results

We suggest a novel role for latrophilin (LPHN) receptors, finding increased expression on ASMC from asthmatics, compared with non-asthmatics in vivo and in vitro, suggesting a role in mediating airway function. A single nucleotide polymorphism in LPHN1 was associated with asthma and with increased LPHN1 expression in lung tissue. When activated, LPHNs regulated ASMC adhesion and proliferation in vitro, and promoted contraction of mouse airways and ASMC.

Conclusions

Given the need for novel inhibitors of airway remodelling and bronchodilators in asthma, the LPHN family may represent promising novel targets for future dual therapeutic intervention.

Inhibition of reactive oxygen species downregulates the MAPK pathway in rat spinal cord after limb ischemia reperfusion injury

INTRODUCTION

We examined the activity of mitogen-activated protein kinase (MAPK) family members, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, in rats pinal cord after hind limb ischemia reperfusion (IR) and analyzed the role of reactive oxygen species (ROS) as mediators of MAPK signaling under these conditions.

METHODS

In experiment 1, hind limb IR rats were treated intraperitoneally with one of following agents at 30 min before reperfusion: allopurinol (4, 40 mg/kg), superoxide dismutase (SOD, 4000 U/kg), N-nitro-l-arginine methyl ester (l-NAME, 10 mg/kg), or SOD (4000 U/kg) + l-NAME (10 mg/kg). In experiment 2, 5,10,15,20-tetrakis (N-methyl-4'-pyridyl) porphyrinato iron (III) (FeTMPyP) was administered intraperitoneally (1, 3, or 10 mg/kg) 30 min before reperfusion. After 3 d reperfusion period, the spinal cord (L4-6) was harvested to investigate MAPK signaling activity.

RESULTS

In experiment 1, p-ERK and p-JNK levels were significantly higher in the IR group than sham group. Administration of allopurinol, SOD, l-NAME, or SOD + l-NAME significantly reduced the IR-induced increase in p-ERK and p-JNK levels. There were no significant differences in p-p38 levels. In experiment 2, FeTMPyP significantly reduced the IR-induced increase in p-ERK and p-JNK levels in a dose-dependent manner.

CONCLUSIONS

Activation of ERK and JNK in the spinal cord was induced by hind limb IR and was not accompanied by p38 activation. IR-induced MAPK phosphorylation was reduced by inhibition of superoxide, nitric oxide, and peroxynitrite, indicating that ROS produced by hind limb IR mediate the activation of these signaling pathways in the spinal cord, potentially affecting distant organs.

High fat diet-Induced obesity alters vitamin D metabolizing enzyme expression in mice

Low serum 25(OH)D concentrations have been reported in obese humans. Inadequate sun exposure and impaired hepatic 25-hydroxylation have been suggested as possible reasons for obesity-associated vitamin D deficiency; however, the underlying mechanism has not been elucidated. We investigated the effects of high fat diet-induced obesity on vitamin D status and vitamin D metabolizing enzyme expression. Male C57BL mice (4 weeks old) were fed control diet containing 10% energy from fat (control group) or high fat diet containing 45% energy from fat (obese group) for 18 weeks. There were no differences in serum 25(OH)D concentrations between two groups, while serum 1,25(OH)2 D concentrations were significantly higher in obese mice. Hepatic mRNA levels of 25-hydroxylases (Cyp2r1, Cyp27a1, and Cyp2j3) were lower in the obese group (31, 30, and 48% lower, respectively). Renal 1α-hydroxylase (Cyp27b1) mRNA levels were higher and 24-hydroxylase (Cyp24) mRNA levels were lower in the obese group. Serum 1,25(OH)2 D concentrations correlated positively with renal Cyp27b1 expression levels and negatively with renal Cyp24 expression levels. Serum PTH concentrations were higher in obese mice. In visceral adipose tissue, Cyp27a1, Cyp2j3, and vitamin D receptor mRNA levels were higher in obese mice. Overall, vitamin D metabolizing enzyme expression was influenced by high fat diet-induced obesity, which might partly explain the mechanisms of the altered vitamin D endocrine system associated with obesity. Higher serum PTH and 1,25(OH)2 D concentrations in obese mice suggest abnormal regulation of serum 1,25(OH)2 D concentrations due to hyperparathyroidism, which might have contributed to lower hepatic 25-hydroxylase mRNA levels.

Dose-related effect of urinary cotinine levels on pulmonary function among Korean women

SETTING

Country-wide general population in South Korea.

BACKGROUND

The dose-response relationship between smoking and pulmonary function in women may have been significantly over-estimated by studies that employed a self-reporting questionnaire.

OBJECTIVE

To evaluate whether this relationship was still observed among Korean women when smoking levels were determined by urinary cotinine measurements.

DESIGN

A total of 4584 Korean women from the spirometry data set of the Korean National Health and Nutrition Examination Surveys IV and V (2008-2010) were included. Analysis of covariance was performed to estimate the dose-related effect of urinary cotinine levels on pulmonary function after adjusting for covariates in this country-wide cross-sectional study.

RESULTS

Compared to urinary cotinine levels (cut-off 50 ng/ml), the false-positive rate of self-reported smoking was 53.2%. After the smokers were divided into deciles, the regression coefficients for percentage forced expiratory volume in 1 second (FEV₁%) and percentage forced expiratory volume/forced volume capacity (FEV₁/FVC) ratio (FEV1/FVC%) were -0.2903 and -0.2680 (%/decile), respectively (both P < 0.001).

CONCLUSION

It is necessary to use objective methods when determining the smoking status of Korean women. Even after reducing information bias, smoking affected pulmonary function in a dose-dependent manner.

Calcium and vitamin D intake maintained from preovariectomy independently affect calcium metabolism and bone properties in Sprague Dawley rats

The interaction of habitual Ca and vitamin D intake from preovariectomy to 4 months postovariectomy on bone and Ca metabolism was assessed. Higher Ca intake suppressed net bone turnover, and both nutrients independently benefitted trabecular structure. Habitual intake of adequate Ca and ~50 nmol/L vitamin D status is most beneficial.

INTRODUCTION

Dietary strategies to benefit bone are typically tested prior to or after menopause but not through menopause transition. We investigated the interaction of Ca and vitamin D status on Ca absorption, bone remodeling, Ca kinetics, and bone strength as rats transitioned through estrogen deficiency.

METHODS

Sprague Dawley rats were randomized at 8 weeks to 0.2 or 1.0 % Ca and 50, 100, or 1,000 IU (1.25, 2.5, or 25 μg) vitamin D/kg diet (2 × 3 factorial design) and ovariectomized at 12 weeks. Urinary (45)Ca excretion from deep-labeled bone was used to assess net bone turnover weekly. Ca kinetics was performed between 25 and 28 weeks. Rats were killed at 29 weeks. Femoral and tibiae structure (by μCT), dynamic histomorphometry, and bone Ca content were assessed.

RESULTS

Mean 25(OH)D for rats on the 50, 100, 1,000 IU vitamin D/kg diet were 32, 54, and 175 nmol/L, respectively. Higher Ca intake ameliorated net bone turnover, reduced fractional Ca absorption and bone resorption, and increased net Ca absorption. Tibial and femoral trabecular structures were enhanced independently by higher Ca and vitamin D intake. Tibial bone width and fracture resistance were enhanced by higher vitamin D intake. Dynamic histomorphometry in the tibia was not affected by either nutrient. A Ca × vitamin D interaction existed in femur length, tibial Ca content, and mass of the soft tissue/extracellular fluid compartment.

CONCLUSIONS

Adequate Ca intake and serum 25(OH)D level of 50 nmol/L provided the most benefit for bone health, mostly through independent effects of Ca and vitamin D.

Electronic structure of Zn doped Fe3O4 thin films

We investigated the effect of Zn doping on the electronic property of magnetite by using optical spectroscopy. The (Zn(x)Fe(1-x))Fe2O4 (ZFFO) (x = 0, 0.2, 0.4, and 0.5) samples were prepared by PLD technique. The XRD measurement revealed that all the samples have an inverse spinel-type of crystalline structure. The M-H curves indicate that the saturation magnetization reduces with the increasing x. From the spectroscopic ellipsometry and infrared spectroscopy, we found that the doping of nonmagnetic Zn2+ ions leads to the dramatic change in the electronic structure of the ZFFO films. We discuss the correlation of our spectra with the electric and magnetic properties of the ZFFO films.

Increased apoB/A-I ratio independently associated with Type 2 diabetes mellitus: cross-sectional study in a Korean population

AIMS

The aim of this study was to investigate whether increased apolipoprotein B/apolipoprotein A-I ratio is associated with Type 2 diabetes mellitus independent of other risk factors for Type 2 diabetes.

METHODS

A total of 70,063 subjects (41,391 men and 28,672 women; mean age 41.5 years) who visited the Health Screening Center at Kangbuk Samsung Hospital for a routine medical check-up between January 2009 and December 2009 were enrolled in this study.

RESULTS

The mean apolipoprotein B/apolipoprotein A-I ratio in the study subjects was 0.66 ± 0.18. The prevalence of Type 2 diabetes increased across the apolipoprotein B/apolipoprotein A-I ratio quartiles (1.0%, 1.6%, 2.9%, and 4.8% for the 1st through 4th quartiles, respectively, P < 0.001) and homeostasis model assessment-insulin resistance (HOMA2-IR) also showed an increasing tendency by quartile (P < 0.001). The apolipoprotein B/apolipoprotein A-I ratio was correlated with age, adiposity, blood pressure, HOMA2-IR value, fasting glucose levels, and other inflammatory marker, including high-sensitivity C-reactive protein, and lipoprotein (a) levels (all P < 0.001). In a multiple logistic regression model, the highest apolipoprotein B/apolipoprotein A-I ratio quartile was associated with Type 2 diabetes, even after controlling for other risk factors for diabetes, such as age, gender, BMI, systolic blood pressure, HOMA2-IR values, high-sensitivity C-reactive protein levels, family history of diabetes, presence of metabolic syndrome, and conventional lipid parameters (odds ratio 1.31; 95% confidence interval 1.17-1.46, P < 0.001).

CONCLUSIONS

The apolipoprotein B/apolipoprotein A-I ratio was found to be associated with Type 2 diabetes independent of other risk factors for diabetes and conventional lipid parameters.

Serum 1,5-anhydroglucitol is associated with diabetic retinopathy in Type 2 diabetes

AIMS

To determine whether there is a relationship between 1,5-anhydroglucitol (1,5-AG), a marker of postprandial hyperglycaemia and glycaemic variability, and the presence of diabetic retinopathy and albuminuria in patients with Type 2 diabetes.

METHODS

Five hundred and sixty-seven patients with Type 2 diabetes (serum creatinine < 133 μmol/l), who were enrolled in the Seoul Metro-City Diabetes Prevention Program (SMC-DPP), were cross-sectionally assessed by multivariate logistic regression analysis.

RESULTS

After controlling for age, sex, binary HbA(1c) levels, duration of diabetes, triglyceride, systolic blood pressure, smoking status, history of hypertension and dyslipidaemia, and the use of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker medication, the odds ratios (95% CI) of diabetic retinopathy were 2.86 (1.12-7.25) for the first (lowest) quartile of 1,5-anhydroglucitol, 2.87 (1.25-6.61) for the second quartile and 0.88 (0.35-2.22) for the third quartile compared with the fourth quartile (P for trend = 0.010). Conversely, the associations between 1,5-anhydroglucitol and clinical albuminuria were non-significant after adjustment. Subjects with low 1,5-anhydroglucitol (< 10.0 μg/ml) were more likely to experience diabetic retinopathy than those with high 1,5-anhydroglucitol (≥ 10.0 μg/ml) under moderate glucose control (HbA(1c) < 8%, 64 mmol/mol) and there were no significant differences in the prevalence of diabetic retinopathy between the subgroup with HbA(1c) < 8% (64 mmol/mol) and low 1,5-anhydroglucitol and the subgroup with HbA(1c) ≥ 8% (64 mmol/mol).

CONCLUSIONS

1,5-Anhydroglucitol levels show close associations with diabetic retinopathy, especially among patients under moderate glucose control, but not with albuminuria. These results suggest that 1,5-anhydroglucitol might be a complementary marker for targeting higher risk group.

Effect of temperature on optical and electronic properties of InGaP/InGaAIP multiple quantum wells

The optical and electronic properties in an InGaP/InGaAIP multiple quantum well (MQW) grown by using molecular-beam epitaxy utilizing the digital alloy technique were investigated through temperature-dependent photoluminescence (PL) measurements and numerical calculations. The high-resolution transmission electron microscopy images showed that the sample clearly displayed the InGaP wells and the InGaAIP barriers and separate confinement heterostructure layers. The PL measurements at various temperatures were performed to investigate the interband transitions of the InGaP/InGaAIP MQW. The electronic subband energies and the wavefunctions in the InGaP/InGaAIP MQW at several temperatures were determined by using a finite element method employing the standard 8-band k x p Lagrangian. The numerical results for optical interband transition energies from the ground state electron subband to the ground state heavy-hole subband of the InGaP/InGaAIP MQW at various temperatures were in reasonable agreement with the excitonic transition energies observed in the PL measurements.

Fat-forming variant of solitary fibrous tumour of the pleura: CT findings

The fat-forming variant of solitary fibrous tumour (SFT) was previously called lipomatous haemangiopericytoma and is a rare variant of solitary fibrous tumour. It predominantly occurs in the deep soft tissues of the retroperitoneum and thigh. Only a handful of cases involving the perineum, spine, thoracic wall and pelvic cavity have been reported in the radiological literature and the fat-forming variant of SFT involving the pleura has not been previously reported. Herein, we report the CT findings of a case of the fat-forming variant of SFT involving the pleura that was treated by excision. Chest CT showed a large lobulated heterogeneous fatty mass with a multifocal enhancing soft-tissue component in the left lower hemithorax. Although rare, the fat-forming variant of SFT of the pleura should be added to the differential diagnosis of fat-containing pleural soft-tissue tumours.

Microbleeds and free active MMP-9 are independent risk factors for neurological deterioration in acute lacunar stroke

BACKGROUND AND PURPOSE

in this prospective study, we evaluated mutual relationships amongst microbleeds, matrix metalloproteinase-9 (MMP-9) and neurological deterioration in patients with their first acute lacunar stroke.

METHODS

based on diffusion-weighted image findings, we recruited 206 patients with their first acute lacunar stroke. Those without a MRI scan were excluded. Small (a maximum lesion diameter of 15 mm) areas of subcortical gray and white matter with increased signals were considered as lacunar infarctions. GRE images were obtained within 24 h of the onset of stroke symptoms. Venous blood was sampled at base line (within 24 h). Clinical, biochemical, rheological and inflammatory parameters, neurological scales and free, active MMP-9 levels were compared between patients with and without microbleeds. Neurological deterioration was defined as an increase in more than two points on the National Institutes of Health Stroke Scale Score baseline 14 days after the onset of lacunar stroke.

RESULTS

of the patients, 79 (38.3%) had microbleeds and 48 (23.3%) showed neurological deterioration. Free, active MMP-9 and C-reactive protein (CRP) levels were significantly increased amongst patients with microbleeds (P < 0.001 and P = 0.047, respectively). Existence of microbleeds (RR = 2.47, 95% CI = 1.25-3.83) and increased free, active MMP-9 (RR = 1.10 per 10 ng/ml, 95% CI = 1.03-1.19) were identified as independent risk factors for neurological deterioration after adjusting for potential confounders.

DISCUSSION

ncreased levels of active MMP-9 and the existence of microbleeds might be useful in predicting the deterioration following an initial acute lacunar stroke.

In-situ synchrotron radiation photoemission spectroscopy study of the initial atomic layer deposition of Al2O3 film on Si(001) substrate

In-situ synchrotron radiation photoemission spectroscopy and X-ray photoemission spectroscopy have been used to investigate the initial stages of Al2O3 growth on a Si(001) substrate by atomic layer deposition (ALD). The core level spectra of Si 2p, O 1s, and Al 2p as well as the valence band spectra were measured at every half reaction in the trimethylaluminum (TMA)-H2O ALD process. The line shape changes and binding energy shifts of the core level spectra reveal that Al2O3 is predominantly formed with a small amount of Si oxide in the initial stages without the formation of Al silicate. All core level spectra were alternately shifted toward higher and lower binding energies sides at every half ALD reaction. This can be explained by the band bending effect induced by different chemical species on the surface during the TMA-H2O ALD reaction. The valence band spectra showed that four cycles of ALD reactions were necessary to complete the electronic structure of the Al2O3 film with a valence band offset of 3.73 eV.

Biomechanical effects of environmental and engineered particles on human airway smooth muscle cells

The past decade has seen significant increases in combustion-generated ambient particles, which contain a nanosized fraction (less than 100 nm), and even greater increases have occurred in engineered nanoparticles (NPs) propelled by the booming nanotechnology industry. Although inhalation of these particulates has become a public health concern, human health effects and mechanisms of action for NPs are not well understood. Focusing on the human airway smooth muscle cell, here we show that the cellular mechanical function is altered by particulate exposure in a manner that is dependent upon particle material, size and dose. We used Alamar Blue assay to measure cell viability and optical magnetic twisting cytometry to measure cell stiffness and agonist-induced contractility. The eight particle species fell into four categories, based on their respective effect on cell viability and on mechanical function. Cell viability was impaired and cell contractility was decreased by (i) zinc oxide (40-100 nm and less than 44 microm) and copper(II) oxide (less than 50 nm); cell contractility was decreased by (ii) fluorescent polystyrene spheres (40 nm), increased by (iii) welding fumes and unchanged by (iv) diesel exhaust particles, titanium dioxide (25 nm) and copper(II) oxide (less than 5 microm), although in none of these cases was cell viability impaired. Treatment with hydrogen peroxide up to 500 microM did not alter viability or cell mechanics, suggesting that the particle effects are unlikely to be mediated by particle-generated reactive oxygen species. Our results highlight the susceptibility of cellular mechanical function to particulate exposures and suggest that direct exposure of the airway smooth muscle cells to particulates may initiate or aggravate respiratory diseases.

Relationship between body composition and bone mineral density (BMD) in perimenopausal Korean women

OBJECTIVES

Osteoporosis is a disease that increases the fracture rates and it is the major cause of increased mortality and morbidity in the elderly people. To determine which component of body composition is most important to bone health, we analysed the relationship between elements of the body composition and bone mineral density (BMD) in Korean women.

DESIGN

Cross-sectional clinical study.

PATIENTS

Totally 1694 women (mean age 51 years) were selected from subjects who participated in a medical check-up program.

MEASUREMENTS

Body composition analysis was performed by segmental bioelectric impedance method and lean mass, fat mass and per cent body fat measured. Waist: hip ratio (WHR) was assessed as a marker for visceral fat. Lumbar spine (L-spine) BMD was measured by dual X-ray absorptiometry (DEXA). As menopausal status could not be confirmed in all subjects, we divided the subjects into two groups according to the age > 50 years and < 50 years.

RESULTS

Among the entire population, 599 subjects (35.4%) were osteopaenic and 229 subjects (13.5%) were osteoporotic. The bivariate correlation among the variables showed that weight had the highest correlation with fat mass. Mean lean mass was decreased and the WHR increased as the subjects progressed from normal to osteoporotic status; fat mass was the highest among the osteopaenic subjects. L-spine BMD showed a positive correlation with lean mass, and a negative correlation with WHR by bivariate correlation analysis. However, fat mass had a negative correlation with L-spine BMD only after adjustment for age and weight. Multiple regression analysis with L-spine BMD as the dependent variable showed that age, height, fasting insulin, lean mass and WHR were significant determinants of the L-spine BMD (R(2) = 0.170, P < 0.05).

CONCLUSION

In this Korean female population, L-spine BMD showed a consistently positive correlation with lean mass and a negative correlation with WHR. Fat mass failed to show any consistent correlation with L-spine BMD in this study population.

The association of serum adipocyte fatty acid-binding protein with coronary artery disease in Korean adults

OBJECTIVES

Adipocyte fatty acid-binding protein (A-FABP), also known as aP2 or FABP4, is abundantly expressed in adipocytes and plays a role in glucose homeostasis. We analyzed the relationship between the coronary artery disease and serum FABP4 levels in Korean adults.

METHODS

In a total of 234 Korean adults, in whom coronary angiograms were performed, anthropometric measurements were done and fasting glucose and lipid profiles were measured. Serum FABP4 levels were measured using ELISA. The presence of metabolic syndrome was diagnosed according to American Heart Association/National Heart, Lung and Blood Institute (AHA/NHBL) criteria with body mass index (BMI) substituted for waist circumference.

RESULTS

Among the subjects, 31.6% had diabetes, 46.9% had metabolic syndrome, and mean log (FABP4) levels showed significantly higher levels in subjects with diabetes. Among the subjects, 42.4% had normal coronary vessel, 34.6% had 1-vessel disease, 13.7% had 2-vessel disease, and 9.4% had 3-vessel disease. Among the parameters, mean age, fasting glucose, and log (FABP4) levels increased significantly as the numbers of stenotic vessel increased from normal to 3-vessel disease, and for FABP4, these significances showed a consistent trend for difference after adjustment for age, gender, BMI, and fasting glucose (P=0.072). Mean log (FABP4) level showed lower values in subjects taking aspirin, and higher values in subjects taking statin and anti-hypertensive drugs.

CONCLUSIONS

Serum FABP4 levels increased as the numbers of stenotic coronary artery increased, although these differences were attenuated after adjustment for age and fasting glucose levels. Various anti-atherogenic medications showed different effects on the serum FABP4 levels, which need further investigation.

Direct comparison of optical frequency combs using a comb-injection-lock technique

This paper demonstrates a direct comparison of optical frequency combs (OFCs) with different repetition rates without a stable intermediate laser using a single-mode comb-injection-lock technique. Two OFCs based on Ti:Sapphire mode-locked lasers were compared utilizing a single-mode diode laser for the selection and the amplification of one mode of an OFC by comb-injection, which makes the direct comb comparison possible. The frequencies of the two combs were found to agree within 0.019 Hz at 352 THz with the uncertainty of 0.25 Hz (7.1 x 10(-16) ). This is one of the best results among the comparisons of combs referenced to a microwave frequency. This technique simplifies the comb comparison utilities and can be applied even when repetition rates differ.

Monoclonal antibody recognizing N-terminal epitope of hepatitis C virus nonstructural 5B inhibits viral RNA replication

The nonstructural 5B (NS5B) protein of hepatitis C virus (HCV) is an RNA-dependent RNA polymerase (RdRp) with a key role in HCV replication. To characterize the functional roles of NS5B in HCV replication, we produced a panel of 10 monoclonal antibodies (mAbs) directed against NS5B protein from mice immunized with functionally active RdRp. The epitopes of eight mAbs are localized in the middle region (amino acid 240-263) of NS5B protein. On the other hand, the epitopes of two mAbs are mapped to amino acids 67-88 at the N-terminus of NS5B protein. To examine the effects of mAbs on HCV-RNA replication, we performed in vitro RdRp assay using either the 3'-untranslated region (UTR) or the full-length of HCV-RNA as a template in the presence of each mAb. mAbs specific for the middle region of NS5B had no effect on RdRp activity. Surprisingly, mAb recognizing the N-terminal region of NS5B inhibited RdRp activity in a dose-dependent manner. We have confirmed the same result using the other subclass of mAb, whose epitope is also localized to the same N-terminal region of NS5B. These data show that NS5B contains a B-cell epitope located between amino acid residues 67 and 88. Binding of this epitope with an antibody interferes with the enzymatic function of NS5B.

Prevalence of obesity and metabolic syndrome in Korean adults

We studied the prevalence and trend of obesity and metabolic syndrome in Korean adults aged at least 20 years using Korean National Health Examination and Nutrition Survey data from 1998 and 2001. The prevalence of body mass index (BMI) > or = 25 kg m(-2) among Korean adults in 2001 was 32.9% in men and 27.4% in women, and the number of Korean men with BMI > or = 25 kg m(-2) has increased markedly since 1998. A significant positive association between obesity and socioeconomic status was found in Korean men, whereas a significant negative association was identified in Korean women. The prevalence rates of waist circumference (WC) > or = 90 cm in men and WC > or = 85 cm in women were 23.4% and 23.1% in 2001 respectively. The prevalence of metabolic syndrome among Korean adults was 15-30% according to various criteria of metabolic syndrome. Future studies are needed to determine the changes in prevalence of obesity and contributing factors for obesity in Koreans.

Enumeration, isolation and identification of diazotrophs from Korean wetland rice varieties grown with long-term application of N and compost and their short-term inoculation effect on rice plants

AIM

This study has been aimed (i) to isolate and identify diazotrophs from Korean rice varieties; (ii) to examine the long-term effect of N and compost on the population dynamics of diazotrophs and (iii) to realize the shot-term inoculation effect of these diazotrophs on rice seedlings.

METHODS AND RESULTS

Diazotrophic and heterotrophic bacterial numbers were enumerated by most probable number method and the isolates were identified based on morphological, physiological, biochemical and 16s rDNA sequence analysis. Long-term application of fertilizer N with compost enhanced both these numbers in rice plants and its environment. Bacteria were high in numbers when malate and azelaic acids were used as carbon source, but less when sucrose was used as a carbon substrate. The combined application promoted the association of diazotrophic bacteria like Azospirillum spp., Herbaspirillum spp., Burkholderia spp., Gluconacetobacter diazotrophicus and Pseudomonas spp. in wetland rice plants. Detection of nifD genes from different diazotrophic isolates indicated their nitrogen fixing ability. Inoculation of a representative isolate from each group onto rice seedlings of the variety IR 36 grown in test tubes indicated the positive effect of these diazotrophs on the growth of rice seedlings though the percentage of N present in the plants did not differ much.

CONCLUSIONS

Application of compost with fertilizer N promoted the diazotrophic and heterotrophic bacterial numbers and their association with wetland rice and its environment. Compost application in high N fertilized fields would avert the reduction of N(2)-fixing bacterial numbers and their association was beneficial to the growth of rice plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

The inhibitory effect of high N fertilization on diazotrophic bacterial numbers could be reduced by the application of compost and this observation would encourage more usage of organic manure. This study has also thrown light on the wider geographic distribution of G. diazotrophicus with wetland rice in temperate region where sugarcane (from which this bacterium was first reported to be associating and thereon from other plant species) is not cultivated.

Recent progress of moving-actuator type mechanical circulatory support systems: AnyHeart and T-PLS

The mechanical circulatory support system using moving-actuator mechanisms were developed by Seoul National University and Korea University. AnyHeart is a fully implanted pulsatile bi-ventricular assist device, and T-PLS is a pulsatile flow versatile extracorporeal life support system. Through lots of in-vitro and in-vivo experiments, the developed mechanical systems are faced to produce on commercial scale. This paper describes the recent progress of two mechanical circulatory support systems, AnyHeart and T-PLS.

A numerical study on the effect of side hole number and arrangement in venous cannulae

Insertion of cannulae into vessels may apply non-physiological load and stress on blood cells, such that adenosine diphosphate may increase and result in hemolysis. Authors used the computational method to simulate the blood flow inside of the cannula. We limited the research to within the drainage cannulae. Nine different cannulae categorized by the number of side holes of 4, 12, and 20, and also categorized by the array type as staggered array, in-line array, and alternative in-line array were studied and compared to the cannulae with no side holes by using computational fluid dynamics. We evaluated the flow rate, the wall shear stress, and the shear rate, and compared them with one another to estimate the effect of the side holes. The flow rate is not proportional to the number of the side holes. However, larger number of side holes can reduce the mean shear rate.

Sweep optical frequency synthesizer with a distributed-Bragg-reflector laser injection locked by a single component of an optical frequency comb

A sweep optical frequency synthesizer is demonstrated by using a frequency-stabilized optical frequency comb and injection-locked distributed-Bragg-reflector (DBR) laser diode. The injection-locked DBR laser acts as a single-frequency filter and, simultaneously, a high-gain amplifier of the optical frequency comb. The frequency instability of the heterodyne beat signal between two independently injection-locked DBR lasers is measured to be 2.3 x 10(-16) at 1 s averaging time. The output frequency of the sweep optical frequency synthesizer can be precisely tuned over 1 GHz, and a saturated absorption spectrum of the Cs D2 line at 852 nm is recorded by the injected DBR laser.

What is the difference between squamous cell carcinoma and adenocarcinoma of the cervix? A matched case–control study

The objective of this study was to investigate the efficacy of treatment strategies in patients with adenocarcinoma (AC) of the cervix and compare it with those with squamous cell carcinoma (SCC) of the cervix. Women with FIGO (1994) stage IB1 AC, especially pathologic tumor size of 2-4 cm, treated with class III hysterectomy, were compared with those with SCC treated with comparable strategy in a case-controlled study. Eighty patients (20 cases, 60 controls) were analyzed. Lymphvascular space invasion (P = 0.01) and lymph node metastasis (P = 0.07) were more frequent in patients with SCC than in those with AC. However, there was no significant difference in depth of stromal invasion (P = 0.51) and invasion of the parametrium (P = 0.44) between two groups. And there was also no statistically significant difference in disease-free survival (P = 0.86) and overall survival (P = 0.89) between two groups. Primary radical surgery followed by adjuvant therapy, same as for SCC, would be acceptable for AC with pathologic tumor size of 2-4 cm. Although it was difficult to determine whether AC recurred more systemically, more effective treatment strategies than those currently available for AC should be considered to reduce the systemic recurrence.

Lymph node metastasis and lymph vascular space invasion in microinvasive squamous cell carcinoma of the uterine cervix

The objective of this study was to determine whether the depth of invasion was related to lymph vascular space invasion (LVSI) and lymph node metastasis and whether there was a correlation between LVSI and lymph node metastasis in stage IA cervical cancer. The medical records, including surgical notes and pathologic reports, of 202 patients with microinvasive squamous cell carcinoma of the uterine cervix were reviewed retrospectively. There was a positive correlation between the depth of invasion and the LVSI, and the incidence of lymph node metastasis was slightly higher than those reported hitherto for stage IA1 cervical cancer, especially in the depth of invasion of 1-3 mm group. However, among four patients with lymph node metastasis, only two patients had positive LVSI. There was no definite correlation between LVSI and lymph node metastasis. LVSI could not identify the patients with high risk for lymph node metastasis.

Estimation of coupled assist flows in a moving-actuator bi-ventricular assist device using interventricular pressure

An assist flow estimation scheme for a moving-actuator biventricular assist device (MA-BVAD) using interventricular pressure (IVP) has been developed. The scheme uses a waveform feature parameter of IVP, peak IVP time (PIT), for estimation of the filling volumes of both left and right blood sacs simultaneously. In a regression analysis on data from an in vivo test in an 85 Kg male calf for 20 days, the PIT was found to have high correlation with the blood sac filling volume (R=0.883: left filling volume, R=0.967: right filling volume). A conceptual equation hypothesizing this correlation between PIT and filling volume was established based on the observation and the unknown parameters were identified using least squares parameter optimization. The estimation equation identified proved highly accurate (R=0.916 for left flow, R=0.970 for right flow). The accuracy of the estimation scheme promises very good practical applicability.