914 A Comparison of Mortality, Indicators of Treatment Success and Complications of Resuscitative Endovascular Balloon Occlusion of Aorta (REBOA): A Systematic Review and Meta-Analysis

Introduction

This study aims to provide an updated review on in-hospital mortality rates in patients who underwent Resuscitative Endovascular Balloon Occlusion of Aorta (REBOA) versus Resuscitative thoracotomy (RT) or standard care without REBOA, to identify potential indicators of REBOA use and complications.

Method

Cochrane and PRISMA guidelines were used to perform the study. A literature search was done from 01 January 2005 to 30 June 2020 using EMBASE, MEDLINE and COCHRANE databases. Meta-analysis was conducted using a random effects model and the DerSimonian and Laird estimation method.

Results

25 studies were included in this study. The odds of in-hospital mortality of patients who underwent REBOA compared to RT was 0.18 (p < 0.01). The odds of in-hospital survival of patients who underwent REBOA compared to non-REBOA was 1.28 (p = 0.62). There was a significant difference found between survivors and non-survivors in terms of their pre-REBOA systolic blood pressure (SBP) (19.26 mmHg, p < 0.01), post-REBOA SBP (20.73 mmHg, p < 0.01), duration of aortic occlusion (-40.57 mins, p < 0.01) and ISS (-8.50, p < 0.01). Common complications of REBOA included acute kidney injury, multi-organ dysfunction and thrombosis.

Conclusions

Our study demonstrated lower in-hospital mortality of REBOA versus RT. Prospective multi-centre studies are needed for further evaluation of the indications, feasibility, and complications of REBOA.

Bioelectronic Nose: An Emerging Tool for Odor Standardization

Odors are perceived differently as a function of individual human experience, and communicating about odors between individuals is therefore very difficult. There is a need to classify and standardize odors, but appropriate tools have not yet been developed. A bioelectronic nose mimics human olfaction and detects target molecules with high sensitivity and selectivity. This new tool has great potential in many applications and is expected to accelerate odor classification and standardization. In particular, a multiplexed bioelectronic nose can provide complex odor information using pattern recognition techniques, and could even reproduce odors via an integrated olfactory display system. We expect that a bioelectronic nose will be a useful tool for odor standardization by providing codes for odors that enable us to communicate odor information.

Bioelectronic nose and its application to smell visualization

There have been many trials to visualize smell using various techniques in order to objectively express the smell because information obtained from the sense of smell in human is very subjective. So far, well-trained experts such as a perfumer, complex and large-scale equipment such as GC-MS, and an electronic nose have played major roles in objectively detecting and recognizing odors. Recently, an optoelectronic nose was developed to achieve this purpose, but some limitations regarding the sensitivity and the number of smells that can be visualized still persist. Since the elucidation of the olfactory mechanism, numerous researches have been accomplished for the development of a sensing device by mimicking human olfactory system. Engineered olfactory cells were constructed to mimic the human olfactory system, and the use of engineered olfactory cells for smell visualization has been attempted with the use of various methods such as calcium imaging, CRE reporter assay, BRET, and membrane potential assay; however, it is not easy to consistently control the condition of cells and it is impossible to detect low odorant concentration. Recently, the bioelectronic nose was developed, and much improved along with the improvement of nano-biotechnology. The bioelectronic nose consists of the following two parts: primary transducer and secondary transducer. Biological materials as a primary transducer improved the selectivity of the sensor, and nanomaterials as a secondary transducer increased the sensitivity. Especially, the bioelectronic noses using various nanomaterials combined with human olfactory receptors or nanovesicles derived from engineered olfactory cells have a potential which can detect almost all of the smells recognized by human because an engineered olfactory cell might be able to express any human olfactory receptor as well as can mimic human olfactory system. Therefore, bioelectronic nose will be a potent tool for smell visualization, but only if two technologies are completed. First, a multi-channel array-sensing system has to be applied for the integration of all of the olfactory receptors into a single chip for mimicking the performance of human nose. Second, the processing technique of the multi-channel system signals should be simultaneously established with the conversion of the signals to visual images. With the use of this latest sensing technology, the realization of a proper smell-visualization technology is expected in the near future.

Targeting and Immobilization of Bioactive Peptides on Dentin Matrix

The regeneration of structurally/functionally competent tooth root cementum is a critical step for the successful restoration of periodontal attachment. In this study, we tested whether a poly-glutamic acid-rich domain and glutamine-containing transglutaminase substrate can be used to target biologically active peptides to the mineralized root matrix and to bind such peptides covalently to the organic matrix. As a biologically active model molecule, the integrin-binding motif, RGD, was used. The effects of immobilization of such synthetic peptides to the dentin matrix on cementoblastic adhesion in vitro and cementogenesis in vivo were studied. In vitro, cementoblastic adhesion improved significantly when the dentin surface contained covalently bound peptides. In vivo, this bound peptide significantly increased cementum formation compared with that attained in control conditions. Transglutaminase-catalyzed covalent binding of bioactive peptides targeted to mineralized collagenous dentin matrix via the poly-glutamate domain can be readily achieved. This approach offers potential for clinical use in periodontal regeneration.

Bioelectronic Nose Using Odorant Binding Protein-Derived Peptide and Carbon Nanotube Field-Effect Transistor for the Assessment of Salmonella Contamination in Food

Salmonella infection is the one of the major causes of food borne illnesses including fever, abdominal pain, diarrhea, and nausea. Thus, early detection of Salmonella contamination is important for our healthy life. Conventional detection methods for the food contamination have limitations in sensitivity and rapidity; thus, the early detection has been difficult. Herein, we developed a bioelectronic nose using a carbon nanotube (CNT) field-effect transistor (FET) functionalized with Drosophila odorant binding protein (OBP)-derived peptide for easy and rapid detection of Salmonella contamination in ham. 3-Methyl-1-butanol is known as a specific volatile organic compound, generated from the ham contaminated with Salmonella. We designed and synthesized the peptide based on the sequence of the Drosophila OBP, LUSH, which specifically binds to alcohols. The C-terminus of the synthetic peptide was modified with three phenylalanine residues and directly immobilized onto CNT channels using the π-π interaction. The p-type properties of FET were clearly maintained after the functionalization using the peptide. The biosensor detected 1 fM of 3-methyl-1-butanol with high selectivity and successfully assessed Salmonella contamination in ham. These results indicate that the bioelectronic nose can be used for the rapid detection of Salmonella contamination in food.

Deficiency of the tumor promoter gene wip1 induces insulin resistance

Diabetes is a growing health care issue, and prediabetes has been established as a risk factor for type 2 diabetes. Prediabetes is characterized by deregulated glucose control, and elucidating pathways which govern this process is critical. We have identified the wild-type (WT) p53-inducible phosphatase (WIP1) phosphatase as a regulator of glucose homeostasis. Initial characterization of insulin signaling in WIP1 knockout (WIP1(KO)) murine embryo fibroblasts demonstrated reduced insulin-mediated Ak mouse transforming activation. In order to assess the role of WIP1 in glucose homeostasis, we performed metabolic analysis on mice on a low-fat chow diet (LFD) and high fat diet (HFD). We observed increased expression of proinflammatory cytokines in WIP1(KO) murine embryo fibroblasts, and WIP1(KO) mice fed a LFD and a HFD. WIP1(KO) mice exhibited glucose intolerance and insulin intolerance on a LFD and HFD. However, the effects of WIP1 deficiency cause different metabolic defects in mice on a LFD and a HFD. WIP1(KO) mice on a LFD develop hepatic insulin resistance, whereas this is not observed in HFD-fed mice. Mouse body weights and food consumption increase slightly over time in LFD-fed WT and WIP1(KO) mice. Leptin levels are increased in LFD-fed WIP1(KO) mice, compared with WT. In contrast, HFD-fed WIP1(KO) mice are resistant to HFD-induced obesity, have decreased levels of food consumption, and decreased leptin levels compared with HFD-WT mice. WIP1 has been shown to regulate the nuclear factor kappa-light-chain-enhancer of activated B cells pathway, loss of which leads to increased inflammation. We propose that this increased inflammation triggers insulin resistance in WIP1(KO) mice on LFD and HFD.

Genetic ablation of lymphocytes and cytokine signaling in nonobese diabetic mice prevents diet-induced obesity and insulin resistance

Obesity is characterized by a dysregulated immune system, which may causally associate with insulin resistance and type 2 diabetes. Despite widespread use of nonobese diabetic (NOD) mice, NOD with severe combined immunodeficiency (scid) mutation (SCID) mice, and SCID bearing a null mutation in the IL-2 common γ chain receptor (NSG) mice as animal models of human diseases including type 1 diabetes, the underlying metabolic effects of a genetically altered immune system are poorly understood. For this, we performed a comprehensive metabolic characterization of these mice fed chow or after 6 wk of a high-fat diet. We found that NOD mice had ∼50% less fat mass and were 2-fold more insulin sensitive, as measured by hyperinsulinemic-euglycemic clamp, than C57BL/6 wild-type mice. SCID mice were also more insulin sensitive with increased muscle glucose metabolism and resistant to diet-induced obesity due to increased energy expenditure (∼10%) and physical activity (∼40%) as measured by metabolic cages. NSG mice were completely protected from diet-induced obesity and insulin resistance with significant increases in glucose metabolism in peripheral organs. Our findings demonstrate an important role of genetic background, lymphocytes, and cytokine signaling in diet-induced obesity and insulin resistance.

Real-time monitoring of geosmin and 2-methylisoborneol, representative odor compounds in water pollution using bioelectronic nose with human-like performance

A bioelectronic nose for the real-time assessment of water quality was constructed with human olfactory receptor (hOR) and single-walled carbon nanotube field-effect transistor (swCNT-FET). Geosmin (GSM) and 2-methylisoborneol (MIB), mainly produced by bacteria, are representative odor compounds and also indicators of contamination in the water supply system. For the screening of hORs which respond to these compounds, we performed CRE-luciferase assays of the two odorants in heterologous cell system. Human OR51S1 for GSM and OR3A4 for MIB were selected, and nanovesicles expressing the hORs on surface were produced from HEK-293 cell. Carbon nanotube field-effect transistor was functionalized with the nanovesicles. The bioelectronic nose was able to selectively detect GSM and MIB at concentrations as low as a 10 ng L(-1). Furthermore, detection of these compounds from the real samples such as tap water, bottled water and river water was available without any pretreatment processes.

The impact of depression and somatic symptoms on treatment outcomes in patients with chronic prostatitis/chronic pelvic pain syndrome: a preliminary study in a naturalistic treatment setting

AIM

The aim of this study was to evaluate the impact of depression and somatic symptoms on treatment outcomes in Korean male patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) attending a routine clinical practice.

METHODS

This was a 12-week prospective observational study (n = 80). The Korean version of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) to measure the severity of CP/CPPS, the Korean version of the Patient Health Questionnaire-9 (PHQ-9) to assess depression, the Korean version of the Patient Health Questionnaire-15 (PHQ-15) to evaluate somatisation and the Korean version of the EuroQol Questionnaire-5 Dimensions (EQ-5D), specifically the EQ-5D utility index and the EQ-5D visual analogue scale (EQ-5D VAS), to assess quality of life, were utilised and given at baseline and week 12. The primary and secondary end-points in this study were changes in the NIH-CPSI total score from baseline to week 12 according to depression and somatisation.

RESULTS

The change in NIH-CPSI total score was significantly higher in those without depression than in those with depression (p = 0.003), with a magnitude of difference of 2.8. The responder rate (a ≥ 4 point decrease in NIH-CPSI total score from baseline) was significantly higher in those without depression (42.9%) than in those with depression (17.2%, p = 0.023). However, significant differences were not observed between the two groups in the other outcome measures or in all study outcomes between subjects with or without somatisation. A logistic regression analysis revealed that the presence or absence of depression may be a principal predictor of response to treatment.

CONCLUSION

These preliminary results indicate that depression may have a negative impact on treatment outcome and is a likely predictor of response to treatment in patients with CP/CPPS. However, additional studies with adequate power and improved design are necessary to further support the present findings.

Nanovesicle-based bioelectronic nose for the diagnosis of lung cancer from human blood

A human nose-mimetic diagnosis system that can distinguish the odor of a lung cancer biomarker, heptanal, from human blood is presented. Selective recognition of the biomarker is mimicked in the human olfactory system. A specific olfactory receptor recognizing the chemical biomarker is first selected through screening a library of human olfactory receptors (hORs). The selected hOR is expressed on the membrane of human embryonic kidney (HEK)-293 cells. Nanovesicles containing the hOR on the membrane are produced from these cells, and are then used for the functionalization of single-walled carbon nanotubes. This strategy allows the development of a sensitive and selective nanovesicle-based bioelectronic nose (NvBN). The NvBN is able to selectively detect heptanal at a concentration as low as 1 × 10(-14) m, a sufficient level to distinguish the blood of a lung cancer patient from the blood of a healthy person. In actual experiments, NvBN could detect an extremely small increase in the amount of heptanal from human blood plasma without any pretreatment processes. This result offers a rapid and easy method to analyze chemical biomarkers from human blood in real-time and to diagnose lung cancer.

Glucose Tolerance in Mice is Linked to the Dose of the p53 Transactivation Domain

AIM

To test the transactivation domain-mediated control of glucose homeostasis by the tumor suppressor p53.

BACKGROUND

The tumor suppressor p53 has a critical role in maintenance of glucose homeostasis. Phosphorylation of Ser18 in the transaction domain of p53 controls the expression of Zpf385a, a zinc finger protein that regulates adipogenesis and adipose function. This results suggest that the transactivation domain of p53 is essential to the control of glucose homeostasis.

MATERIALS AND METHODS

Mice with mutations in the p53 transactivation domain were examined for glucose homeostasis as well as various metabolic parameters. Glucose tolerance and insulin tolerance tests were performed on age matched wild type and mutant animals. In addition, mice expressing increased dosage of p53 were also examined.

RESULTS

Mice with a mutation in p53Ser18 exhibit reduced Zpf385a expression in adipose tissue, adipose tissue-specific insulin resistance, and glucose intolerance. Mice with relative deficits in the transactivation domain of p53 exhibit similar defects in glucose homeostasis, while "Super p53" mice with an increased dosage of p53 exhibit improved glucose tolerance.

CONCLUSION

These data support the role of an ATM-p53 cellular stress axis that helps combat glucose intolerance and insulin resistance and regulates glucose homeostasis.

Molecular network analysis of phosphotyrosine and lipid metabolism in hepatic PTP1b deletion mice

Metabolic syndrome describes a set of obesity-related disorders that increase diabetes, cardiovascular, and mortality risk. Studies of liver-specific protein-tyrosine phosphatase 1b (PTP1b) deletion mice (L-PTP1b(-/-)) suggest that hepatic PTP1b inhibition would mitigate metabolic-syndrome through amelioration of hepatic insulin resistance, endoplasmic-reticulum stress, and whole-body lipid metabolism. However, the altered molecular-network states underlying these phenotypes are poorly understood. We used mass spectrometry to quantify protein-phosphotyrosine network changes in L-PTP1b(-/-) mouse livers relative to control mice on normal and high-fat diets. We applied a phosphosite-set-enrichment analysis to identify known and novel pathways exhibiting PTP1b- and diet-dependent phosphotyrosine regulation. Detection of a PTP1b-dependent, but functionally uncharacterized, set of phosphosites on lipid-metabolic proteins motivated global lipidomic analyses that revealed altered polyunsaturated-fatty-acid (PUFA) and triglyceride metabolism in L-PTP1b(-/-) mice. To connect phosphosites and lipid measurements in a unified model, we developed a multivariate-regression framework, which accounts for measurement noise and systematically missing proteomics data. This analysis resulted in quantitative models that predict roles for phosphoproteins involved in oxidation-reduction in altered PUFA and triglyceride metabolism.

Short-term weight loss attenuates local tissue inflammation and improves insulin sensitivity without affecting adipose inflammation in obese mice

Obesity is a major cause of insulin resistance, and weight loss is shown to improve glucose homeostasis. But the underlying mechanism and the role of inflammation remain unclear. Male C57BL/6 mice were fed a high-fat diet (HFD) for 12 wk. After HFD, weight loss was induced by changing to a low-fat diet (LFD) or exercise with continuous HFD. The weight loss effects on energy balance and insulin sensitivity were determined using metabolic cages and hyperinsulinemic euglycemic clamps in awake mice. Diet and exercise intervention for 3 wk caused a modest weight loss and improved glucose homeostasis. Weight loss dramatically reduced local inflammation in skeletal muscle, liver, and heart but not in adipose tissue. Exercise-mediated weight loss increased muscle glucose metabolism without affecting Akt phosphorylation or lipid levels. LFD-mediated weight loss reduced lipid levels and improved insulin sensitivity selectively in liver. Both weight loss interventions improved cardiac glucose metabolism. These results demonstrate that a short-term weight loss with exercise or diet intervention attenuates obesity-induced local inflammation and selectively improves insulin sensitivity in skeletal muscle and liver. Our findings suggest that local factors, not adipose tissue inflammation, are involved in the beneficial effects of weight loss on glucose homeostasis.

Baf60c drives glycolytic metabolism in the muscle and improves systemic glucose homeostasis through Deptor-mediated Akt activation

A shift from oxidative to glycolytic metabolism has been associated with skeletal muscle insulin resistance in type 2 diabetes^1–5. However, whether this metabolic switch is deleterious or adaptive remains controversial^6–8, in part due to limited understanding of the regulatory network that directs the metabolic and contractile specification of fast-twitch glycolytic muscle. Here we show that BAF60c, a transcriptional cofactor enriched in fast-twitch muscle, promotes a switch from oxidative to glycolytic myofiber type through Deptor-mediated AKT activation. Muscle-specific transgenic expression of BAF60c activates a program of molecular, metabolic, and contractile changes characteristic of glycolytic muscle. In addition, BAF60c is required for maintaining glycolytic capacity in adult skeletal muscle in vivo. BAF60c expression is significantly decreased in skeletal muscle from obese mice. Unexpectedly, transgenic activation of the glycolytic muscle program by BAF60c protects mice from diet-induced insulin resistance and glucose intolerance. Further mechanistic studies revealed that Deptor is induced by the BAF60c/Six4 transcriptional complex and mediates activation of AKT and glycolytic metabolism by BAF60c in a cell-autonomous manner. This work defines a fundamental mechanism underlying the specification of fast glycolytic muscle and illustrates that the oxidative to glycolytic metabolic shift in skeletal muscle is potentially adaptive and beneficial in the diabetic state.

TRPM2 Ca2+ channel regulates energy balance and glucose metabolism

TRPM2 Ca(2+)-permeable cation channel is widely expressed and activated by markers of cellular stress. Since inflammation and stress play a major role in insulin resistance, we examined the role of TRPM2 Ca(2+) channel in glucose metabolism. A 2-h hyperinsulinemic euglycemic clamp was performed in TRPM2-deficient (KO) and wild-type mice to assess insulin sensitivity. To examine the effects of diet-induced obesity, mice were fed a high-fat diet for 4-10 mo, and metabolic cage and clamp studies were conducted in conscious mice. TRPM2-KO mice were more insulin sensitive partly because of increased glucose metabolism in peripheral organs. After 4 mo of high-fat feeding, TRPM2-KO mice were resistant to diet-induced obesity, and this was associated with increased energy expenditure and elevated expressions of PGC-1α, PGC-1β, PPARα, ERRα, TFAM, and MCAD in white adipose tissue. Hyperinsulinemic euglycemic clamps showed that TRPM2-KO mice were more insulin sensitive, with increased Akt and GSK-3β phosphorylation in heart. Obesity-mediated inflammation in adipose tissue and liver was attenuated in TRPM2-KO mice. Overall, TRPM2 deletion protected mice from developing diet-induced obesity and insulin resistance. Our findings identify a novel role of TRPM2 Ca(2+) channel in the regulation of energy expenditure, inflammation, and insulin resistance.

Cytoplasmic polyadenylation element binding protein deficiency stimulates PTEN and Stat3 mRNA translation and induces hepatic insulin resistance

The cytoplasmic polyadenylation element binding protein CPEB1 (CPEB) regulates germ cell development, synaptic plasticity, and cellular senescence. A microarray analysis of mRNAs regulated by CPEB unexpectedly showed that several encoded proteins are involved in insulin signaling. An investigation of Cpeb1 knockout mice revealed that the expression of two particular negative regulators of insulin action, PTEN and Stat3, were aberrantly increased. Insulin signaling to Akt was attenuated in livers of CPEB-deficient mice, suggesting that they might be defective in regulating glucose homeostasis. Indeed, when the Cpeb1 knockout mice were fed a high-fat diet, their livers became insulin-resistant. Analysis of HepG2 cells, a human liver cell line, depleted of CPEB demonstrated that this protein directly regulates the translation of PTEN and Stat3 mRNAs. Our results show that CPEB regulated translation is a key process involved in insulin signaling.

Fat cell-specific ablation of rictor in mice impairs insulin-regulated fat cell and whole-body glucose and lipid metabolism

OBJECTIVE

Rictor is an essential component of mammalian target of rapamycin (mTOR) complex (mTORC) 2, a kinase that phosphorylates and activates Akt, an insulin signaling intermediary that regulates glucose and lipid metabolism in adipose tissue, skeletal muscle, and liver. To determine the physiological role of rictor/mTORC2 in insulin signaling and action in fat cells, we developed fat cell-specific rictor knockout (FRic(-/-)) mice.

RESEARCH DESIGN AND METHODS

Insulin signaling and glucose and lipid metabolism were studied in FRic(-/-) fat cells. In vivo glucose metabolism was evaluated by hyperinsulinemic-euglycemic clamp.

RESULTS

Loss of rictor in fat cells prevents insulin-stimulated phosphorylation of Akt at S473, which, in turn, impairs the phosphorylation of downstream targets such as FoxO3a at T32 and AS160 at T642. However, glycogen synthase kinase-3beta phosphorylation at S9 is not affected. The signaling defects in FRic(-/-) fat cells lead to impaired insulin-stimulated GLUT4 translocation to the plasma membrane and decreased glucose transport. Furthermore, rictor-null fat cells are unable to suppress lipolysis in response to insulin, leading to elevated circulating free fatty acids and glycerol. These metabolic perturbations are likely to account for defects observed at the whole-body level of FRic(-/-) mice, including glucose intolerance, marked hyperinsulinemia, insulin resistance in skeletal muscle and liver, and hepatic steatosis.

CONCLUSIONS

Rictor/mTORC2 in fat cells plays an important role in whole-body energy homeostasis by mediating signaling necessary for the regulation of glucose and lipid metabolism in fat cells.

Role of the hypothalamic-pituitary-thyroid axis in metabolic regulation by JNK1

The cJun N-terminal kinase 1 (JNK1) is implicated in diet-induced obesity. Indeed, germline ablation of the murine Jnk1 gene prevents diet-induced obesity. Here we demonstrate that selective deficiency of JNK1 in the murine nervous system is sufficient to suppress diet-induced obesity. The failure to increase body mass is mediated, in part, by increased energy expenditure that is associated with activation of the hypothalamic-pituitary-thyroid axis. Disruption of thyroid hormone function prevents the effects of nervous system JNK1 deficiency on body mass. These data demonstrate that the hypothalamic-pituitary-thyroid axis represents an important target of metabolic signaling by JNK1.

Grp78 heterozygosity promotes adaptive unfolded protein response and attenuates diet-induced obesity and insulin resistance

OBJECTIVE

To investigate the role of the endoplasmic reticulum (ER) chaperone glucose-regulated protein (GRP) 78/BiP in the pathogenesis of obesity, insulin resistance, and type 2 diabetes.

RESEARCH DESIGN AND METHODS

Male Grp78(+/-) mice and their wild-type littermates were subjected to a high-fat diet (HFD) regimen. Pathogenesis of obesity and type 2 diabetes was examined by multiple approaches of metabolic phenotyping. Tissue-specific insulin sensitivity was analyzed by hyperinsulinemic-euglycemic clamps. Molecular mechanism was explored via immunoblotting and tissue culture manipulation.

RESULTS

Grp78 heterozygosity increases energy expenditure and attenuates HFD-induced obesity. Grp78(+/-) mice are resistant to diet-induced hyperinsulinemia, liver steatosis, white adipose tissue (WAT) inflammation, and hyperglycemia. Hyperinsulinemic-euglycemic clamp studies revealed that Grp78 heterozygosity improves glucose metabolism independent of adiposity and following an HFD increases insulin sensitivity predominantly in WAT. As mechanistic explanations, Grp78 heterozygosity in WAT under HFD stress promotes adaptive unfolded protein response (UPR), attenuates translational block, and upregulates ER degradation-enhancing alpha-mannosidase-like protein (EDEM) and ER chaperones, thus improving ER quality control and folding capacity. Further, overexpression of the active form of ATF6 induces protective UPR and improves insulin signaling upon ER stress.

CONCLUSIONS

HFD-induced obesity and type 2 diabetes are improved in Grp78(+/-) mice. Adaptive UPR in WAT could contribute to this improvement, linking ER homeostasis to energy balance and glucose metabolism.

Uncoupling of inflammation and insulin resistance by NF-kappaB in transgenic mice through elevated energy expenditure

To study the metabolic activity of NF-kappaB, we investigated phenotypes of two different mouse models with elevated NF-kappaB activities. The transcriptional activity of NF-kappaB is enhanced either by overexpression of NF-kappaB p65 (RelA) in aP2-p65 mice or inactivation of NF-kappaB p50 (NF-kappaB1) through gene knock-out. In these models, energy expenditure was elevated in day and night time without a change in locomotion. The mice were resistant to adulthood obesity and diet-induced obesity without reduction in food intake. The adipose tissue growth and adipogenesis were inhibited by the elevated NF-kappaB activity. Peroxisome proliferator-activator receptor gamma expression was reduced by NF-kappaB at the transcriptional level. The two models exhibited elevated inflammatory cytokines (tumor necrosis factor-alpha and interleukin-6) in adipose tissue and serum. However, insulin sensitivity was not reduced by the inflammation in the mice on a chow diet. On a high fat diet, the mice were protected from insulin resistance. The glucose infusion rate was increased more than 30% in the hyperinsulinemic-euglycemic clamp test. Our data suggest that the transcription factor NF-kappaB promotes energy expenditure and inhibits adipose tissue growth. The two effects lead to prevention of adulthood obesity and dietary obesity. The energy expenditure may lead to disassociation of inflammation with insulin resistance. The study indicates that inflammation may prevent insulin resistance by eliminating lipid accumulation.

Nutrient stress activates inflammation and reduces glucose metabolism by suppressing AMP-activated protein kinase in the heart

OBJECTIVE

Heart failure is a major cause of mortality in diabetes and may be causally associated with altered metabolism. Recent reports indicate a role of inflammation in peripheral insulin resistance, but the impact of inflammation on cardiac metabolism is unknown. We investigated the effects of diet-induced obesity on cardiac inflammation and glucose metabolism in mice.

RESEARCH DESIGN AND METHODS

Male C57BL/6 mice were fed a high-fat diet (HFD) for 6 weeks, and heart samples were taken to measure insulin sensitivity, glucose metabolism, and inflammation. Heart samples were also examined following acute interleukin (IL)-6 or lipid infusion in C57BL/6 mice and in IL-6 knockout mice following an HFD.

RESULTS

Diet-induced obesity reduced cardiac glucose metabolism, GLUT, and AMP-activated protein kinase (AMPK) levels, and this was associated with increased levels of macrophages, toll-like receptor 4, suppressor of cytokine signaling 3 (SOCS3), and cytokines in heart. Acute physiological elevation of IL-6 suppressed glucose metabolism and caused insulin resistance by increasing SOCS3 and via SOCS3-mediated inhibition of insulin receptor substrate (IRS)-1 and possibly AMPK in heart. Diet-induced inflammation and defects in glucose metabolism were attenuated in IL-6 knockout mice, implicating the role of IL-6 in obesity-associated cardiac inflammation. Acute lipid infusion caused inflammation and raised local levels of macrophages, C-C motif chemokine receptor 2, SOCS3, and cytokines in heart. Lipid-induced cardiac inflammation suppressed AMPK, suggesting the role of lipid as a nutrient stress triggering inflammation.

CONCLUSIONS

Our findings that nutrient stress activates cardiac inflammation and that IL-6 suppresses myocardial glucose metabolism via inhibition of AMPK and IRS-1 underscore the important role of inflammation in the pathogenesis of diabetic heart.

Interleukin-10 prevents diet-induced insulin resistance by attenuating macrophage and cytokine response in skeletal muscle

OBJECTIVE

Insulin resistance is a major characteristic of type 2 diabetes and is causally associated with obesity. Inflammation plays an important role in obesity-associated insulin resistance, but the underlying mechanism remains unclear. Interleukin (IL)-10 is an anti-inflammatory cytokine with lower circulating levels in obese subjects, and acute treatment with IL-10 prevents lipid-induced insulin resistance. We examined the role of IL-10 in glucose homeostasis using transgenic mice with muscle-specific overexpression of IL-10 (MCK-IL10).

RESEARCH DESIGN AND METHODS

MCK-IL10 and wild-type mice were fed a high-fat diet (HFD) for 3 weeks, and insulin sensitivity was determined using hyperinsulinemic-euglycemic clamps in conscious mice. Biochemical and molecular analyses were performed in muscle to assess glucose metabolism, insulin signaling, and inflammatory responses.

RESULTS

MCK-IL10 mice developed with no obvious anomaly and showed increased whole-body insulin sensitivity. After 3 weeks of HFD, MCK-IL10 mice developed comparable obesity to wild-type littermates but remained insulin sensitive in skeletal muscle. This was mostly due to significant increases in glucose metabolism, insulin receptor substrate-1, and Akt activity in muscle. HFD increased macrophage-specific CD68 and F4/80 levels in wild-type muscle that was associated with marked increases in tumor necrosis factor-alpha, IL-6, and C-C motif chemokine receptor-2 levels. In contrast, MCK-IL10 mice were protected from diet-induced inflammatory response in muscle.

CONCLUSIONS

These results demonstrate that IL-10 increases insulin sensitivity and protects skeletal muscle from obesity-associated macrophage infiltration, increases in inflammatory cytokines, and their deleterious effects on insulin signaling and glucose metabolism. Our findings provide novel insights into the role of anti-inflammatory cytokine in the treatment of type 2 diabetes.

Cell-based olfactory biosensor using microfabricated planar electrode

The initial event in olfactory perception is the binding of odorant molecules to specific receptor proteins in the human nose. The interaction between odorant and receptor initiates olfactory signal transduction that leads to a cation influx and change in the membrane potential of the olfactory sensory neuron. In this study, a microfabricated planar electrode was used to measure the generated membrane potential in a heterologous olfactory system. Human embryonic kidney (HEK)-293 cells expressing the olfactory receptor I7 were transfected with the gustatory cyclic nucleotide gated (CNG) channel to amplify the membrane potential. A microfabricated planar electrode was used to measure the electrical responses of odorant-receptor binding. Stimulation of the olfactory receptor with its specific odorant caused an intracellular Ca(2+) influx, which was quantitatively measured using a planar electrode. The extracellular field potential generated by the Ca(2+) influx through the CNGgust channel of the cells was approximately 10 mV. This cell-based olfactory biosensor, which uses a microfabricated planar electrode for detection, would be useful for screening specific ligands for binding to orphan olfactory receptors.

A stress signaling pathway in adipose tissue regulates hepatic insulin resistance

A high-fat diet causes activation of the regulatory protein c-Jun NH2-terminal kinase 1 (JNK1) and triggers development of insulin resistance. JNK1 is therefore a potential target for therapeutic treatment of metabolic syndrome. We explored the mechanism of JNK1 signaling by engineering mice in which the Jnk1 gene was ablated selectively in adipose tissue. JNK1 deficiency in adipose tissue suppressed high-fat diet-induced insulin resistance in the liver. JNK1-dependent secretion of the inflammatory cytokine interleukin-6 by adipose tissue caused increased expression of liver SOCS3, a protein that induces hepatic insulin resistance. Thus, JNK1 activation in adipose tissue can cause insulin resistance in the liver.

Nonobese, insulin-deficient Ins2Akita mice develop type 2 diabetes phenotypes including insulin resistance and cardiac remodeling

Although insulin resistance has been traditionally associated with type 2 diabetes, recent evidence in humans and animal models indicates that insulin resistance may also develop in type 1 diabetes. A point mutation of insulin 2 gene in Ins2(Akita) mice leads to pancreatic beta-cell apoptosis and hyperglycemia, and these mice are commonly used to investigate type 1 diabetes and complications. Since insulin resistance plays an important role in diabetic complications, we performed hyperinsulinemic-euglycemic clamps in awake Ins2(Akita) and wild-type mice to measure insulin action and glucose metabolism in vivo. Nonobese Ins2(Akita) mice developed insulin resistance, as indicated by an approximately 80% reduction in glucose infusion rate during clamps. Insulin resistance was due to approximately 50% decreases in glucose uptake in skeletal muscle and brown adipose tissue as well as hepatic insulin action. Skeletal muscle insulin resistance was associated with a 40% reduction in total GLUT4 and a threefold increase in PKCepsilon levels in Ins2(Akita) mice. Chronic phloridzin treatment lowered systemic glucose levels and normalized muscle insulin action, GLUT4 and PKCepsilon levels in Ins2(Akita) mice, indicating that hyperglycemia plays a role in insulin resistance. Echocardiography showed significant cardiac remodeling with ventricular hypertrophy that was ameliorated following chronic phloridzin treatment in Ins2(Akita) mice. Overall, we report for the first time that nonobese, insulin-deficient Ins2(Akita) mice develop type 2 diabetes phenotypes including peripheral and hepatic insulin resistance and cardiac remodeling. Our findings provide important insights into the pathogenesis of metabolic abnormalities and complications affecting type 1 diabetes and lean type 2 diabetes subjects.

Improved glucose homeostasis in mice with muscle-specific deletion of protein-tyrosine phosphatase 1B

Obesity and type 2 diabetes are characterized by insulin resistance. Mice lacking the protein-tyrosine phosphatase PTP1B in all tissues are hypersensitive to insulin but also have diminished fat stores. Because adiposity affects insulin sensitivity, the extent to which PTP1B directly regulates glucose homeostasis has been unclear. We report that mice lacking PTP1B only in muscle have body weight and adiposity comparable to those of controls on either chow or a high-fat diet (HFD). Muscle triglycerides and serum adipokines are also affected similarly by HFD in both groups. Nevertheless, muscle-specific PTP1B(-/-) mice exhibit increased muscle glucose uptake, improved systemic insulin sensitivity, and enhanced glucose tolerance. These findings correlate with and are most likely caused by increased phosphorylation of the insulin receptor and its downstream signaling components. Thus, muscle PTP1B plays a major role in regulating insulin action and glucose homeostasis, independent of adiposity. In addition, rosiglitazone treatment of HFD-fed control and muscle-specific PTP1B(-/-) mice revealed that rosiglitazone acts additively with PTP1B deletion. Therefore, combining PTP1B inhibition with thiazolidinediones should be more effective than either alone for treating insulin-resistant states.

Hyperglycemia, maturity-onset obesity, and insulin resistance in NONcNZO10/LtJ males, a new mouse model of type 2 diabetes

As a new mouse model of obesity-induced diabetes generated by combining quantitative trait loci from New Zealand Obese (NZO/HlLt) and Nonobese Nondiabetic (NON/LtJ) mice, NONcNZO10/LtJ (RCS10) male mice developed type 2 diabetes characterized by maturity onset obesity, hyperglycemia, and insulin resistance. To metabolically profile the progression to diabetes in preobese and obese states, a 2-h hyperinsulinemic euglycemic clamp was performed and organ-specific changes in insulin action were assessed in awake RCS10 and NON/LtJ (control) males at 8 and 13 wk of age. Prior to development of obesity and attendant increases in hepatic lipid content, 8-wk-old RCS10 mice developed insulin resistance in liver and skeletal muscle due to significant decreases in insulin-stimulated glucose uptake and GLUT4 expression in muscle. Transition to an obese and hyperglycemic state by 13 wk of age exacerbated insulin resistance in skeletal muscle, liver, and heart associated with organ-specific increases in lipid content. Thus, this polygenic mouse model of type 2 diabetes, wherein plasma insulin is only modestly elevated and obesity develops with maturity yet insulin action and glucose metabolism in skeletal muscle and liver are reduced at an early prediabetic age, should provide new insights into the etiology of type 2 diabetes.

Functional analysis of olfactory receptors expressed in a HEK-293 cell system by using cameleons

Cameleon is a genetically engineered Ca2+ sensing molecule consisting of two variants of the green fluorescent protein (GFP), calmodulin and calmodulin-binding protein, M13. HEK-293 cells stably expressing three types of cameleons, yellow cameleon-2, cameleon-3er, and cameleon-2nu, were constructed, and the expression and localization of these cameleons were confirmed by fluorescent imaging. Among the cameleons, the yellow cameleon-2 was selected for analyzing the change in Ca2+ induced by the olfactory receptor-mediated signal transduction, because it is localized in the cytosol and binds to cytosolic Ca2+ ions. Cells stably expressing yellow cameleon-2 were transfected with each of the test olfactory receptor genes, odr-l0 and 17, and the expression of the olfactory receptor genes were examined using immunocytochemical methods and RT-PCR. Stimulating each olfactory receptor with its specific odorant caused an increase in the intracellular Ca2+ level, which was measured using yellow cameleon-2. These results demonstrate that yellow cameleon-2 can be conveniently used to examine the function of the olfactory receptors expressed in heterologous cells.

The shape control of ZnO based nanostructures

Tetrapod-shape ZnO nanostructures are formed on Si substrates by vapor phase transportation method. The effects of two important growth parameters, growth temperature and VI/II ratio, are investigated. The growth temperature is varied in the range from 600 degrees C to 900 degrees C to control the vapor pressure of group II-element and the formation process of nanostructures. VI/II ratio was changed by adjusting the flux of carrier gas which affects indirectly the supplying rate of group VI-element. From the scanning electron microscopy (SEM), systematic variation of shape including cluster, rod, wire and tetrapod was observed. ZnO tetrapods, formed at 800 degrees C under the carrier gas flux of 0.5 cc/mm2 min, show considerably uniform shape with 100 nm thick and 1-1.5 microm long legs. Also stoichiometric composition (O/Zn - 1) was observed without any second phase structures. While, the decrease of growth temperature and the increase of carrier gas flux, results in the irregular shaped nanostructures with non-stoichiometric composition. The excellent luminescence properties, strong excitonic UV emission at 3.25 eV without deep level emission, indicate that the high crystalline quality tetrapod structures can be formed at the optimized growth conditions.

Growth of well-aligned ZnO nanorods using auge catalyst by vapor phase transportation

Well-aligned ZnO nanorods have been achieved using new alloy (AuGe) catalyst. Zn powder was used as a source material and it was transported in a horizontal tube furnace onto an AuGe deposited Si substrates. The structural and optical properties of ZnO nanorods were characterized by scanning electron microscopy, high resolution X-ray diffraction, and photoluminescence. ZnO nanorods grown at 650 degrees C on 53 nm thick AuGe layer show uniform shape with the length of 8 +/- 0.5 microm and the diameter of 150 +/- 5 nm. Also, the tilting angle of ZnO nanorods (+/- 5.5 degrees) is confirmed by HRXRD. High structural quality of the nanorods is conformed by the photoluminescence measurement. All samples show strong UV emission without considerable deep level emission. However, weak deep level emission appears at high (700 degrees C) temperature due to the increase of oxygen desertion.

Piezoelectric biosensor using olfactory receptor protein expressed in Escherichia coli

An olfactory receptor protein of C. elegans, ODR-10, was expressed in Escherichia coli as a fusion protein, with GST and 6x His-tag. The expression of the target protein was analyzed by SDS-PAGE and Western blot, and was confirmed to be expressed at the membrane fraction of the host E. coli. The surface of a quartz crystal microbalance (QCM) was coated with crude membrane extracts, containing the expressed receptor protein, and the interaction between the olfactory receptor and various odorant molecules examined. Compared with other odorants, diacetyl (2,3-butanedione), known as a natural ligand for the ODR-10 receptor, interacted most strongly with the expressed protein. Various concentrations of diacetyl were applied to the expressed ODR-10 receptor, and the response of the QCM showed a linear relationship to the logarithmic value of the odorant concentration. This piezoelectric biosensor system, using olfactory receptor proteins expressed in E. coli, can be used in diagnostics, toxic chemical detection and the quality control of food.

Dual signal transduction mediated by a single type of olfactory receptor expressed in a heterologous system

Controversy exists over the relationship between the cAMP and IP3 pathways in vertebrate olfactory signal transduction, as this process is known to occur by either of the two pathways. Recent studies have shown that a single olfactory neuron responds to both cAMP- and IP3-producing odorants, suggesting the existence of an olfactory receptor protein that can recognize both ligands. In this study we found that the rat olfactory receptor I7, stably expressed in HEK-293 cells, triggers the cAMP pathway upon stimulation by a specific odorant (octanal) at concentrations lower than 10-4 M; however, the receptor triggers both pathways at higher concentrations. This indicates that a single olfactory receptor, stimulated by a single pathway-inducing odorant, can evoke both pathways at high odorant concentrations. Using this heterologous system, both the dose-dependent response and receptor I7 specificity were analyzed. The dose-dependent Ca2+ response curve, which also includes the release of Ca2+ ions from internal stores at high odorant concentrations, was not monotonous, but had a local maximum and minimum with 10-10 and 10-7 M octanal, respectively, and reached a plateau at 10-2 M octanal. The specificity of the I7 receptor was lower when exposed to higher concentrations of odorants.

Piezoelectric olfactory biosensor: ligand specificity and dose-dependence of an olfactory receptor expressed in a heterologous cell system

An olfactory receptor protein of rats, I7, was expressed on the surface of human embryonic kidney (HEK)-293 cells. For targeting and detecting the protein, rho-tag import sequence was fused with the I7 protein. The olfactory receptor was expressed on the plasma membrane of HEK-293 cells, and stable cell lines regulated by an inducer were obtained. The expression on the cell surface was confirmed by immunocytochemical and Western blotting methods, and the binding of specific odorant molecules to the olfactory receptor was measured using quartz crystal microbalance (QCM). The results for QCM coated with cells containing the olfactory receptor showed that the expressed protein I7 strongly interacted with octyl aldehyde (octanal), which is an odorant specific to the I7 protein. Several other odorants were tested, and the results showed that I7 interacted differently with them. The QCM response to the serial concentrations of octyl aldehyde showed that the response is dose dependent. All these results indicate that the I7 receptor protein expressed on the surface of the heterologous cell system is sensitive to the specific odorant and can be used for the quantitative measurement of the odorant.

Magnetic resonance imaging and proton magnetic resonance spectroscopy in neuro-Behçet's disease

OBJECTIVE

Neuro-Behcet's disease (NBD) is one of the most serious complications of Behcet's disease (BD). Proton magnetic resonance spectroscopy (1H MRS) has been proved to be useful in detecting neuro-metabolic abnormalities in various diseases affecting the brain. In this study, we attempted to characterize the magnetic resonance imaging (MRI) findings in Korean patients with NBD and then examined the usefulness of 1HMRS in evaluating the MRI-negative brain area of NBD patients.

METHODS

We performed brain MRI in 18 BD patients with neurologic symptoms and signs. Seven NBD patients without thalamic lesions and 8 healthy controls underwent brain 1H MRS, in which an 8 ml voxel was placed in the left thalamus and the N-acetylaspartate (NAA)/creatine (Cr) ratio was measured.

RESULTS

Fourteen of 18 BD patients were diagnosed as having NBD and 12 NBD patients (86%) had brain lesions on MRI. Most lesions were of high signal intensity on T2-weighted images and located in the midbrain, pons, basal ganglia, and white matter. On 1H MRS, the thalamic area without gross abnormalities on MRI showed a significantly lower NAA/Cr ratio in NBD patients compared to healthy controls (1.07 +/- 0.08 versus 1.54 +/- 0.27, P < 0.01). In 2 NBD patients, the NAA/Cr ratios, monitored serially, were normalized along with clinical improvement 6 months after treatment with prednisolone and immune suppressive agents.

CONCLUSION

MRI is a very sensitive diagnostic method for NBD, and 1H MRS may be useful for the early detection and follow-up of MRI-negative NBD.

Nonlinear analysis of the EEG of schizophrenics with optimal embedding dimension

We estimated the correlation dimensions of EEGs in patients with schizophrenia to investigate the dynamical properties underlying the EEG. We employed a new method, proposed by Kennel et al. (Kennel MB, Brown R, Abarbanel HDI. Determining embedding dimension for phase-space reconstruction using a geometrical construction. Phys Rev A 1992;45:3403-11), to calculate the correlation dimension D2. That method determined the proper minimum embedding dimension by looking at the behaviour of nearest neighbours under a change in the embedding dimension d from d to d + 1. We demonstrated that for limited noisy data, our algorithm was strikingly faster and more accurate than previous ones. We estimated the D2 of EEGs from 16 channels in patients with schizophrenia according to DSM-IV whereas previous studies, which estimated chaoticity of EEG in schizophrenia, recorded EEG only in a limited number of channels. Schizophrenic patients had a lower correlation dimension in the left inferior frontal and anterior temporal regions compared with controls. Our finding of decreased left frontal and temporal chaotic activity in schizophrenics is in line with the findings of a hypofrontality and hypotemporality reported in previous clinical studies such as EEG, blood flow, brain MRI and positron emission tomography studies in schizophrenia. This result suggests that chaos analysis may be a useful tool in analysing EEG data to explore the brain mechanism of schizophrenia.

Reliability and validity of the cognitive impairment diagnosing instrument (CIDI) in the elderly

The reliability and validity of the Cognitive Impairment Diagnosing Instrument (CIDI) were studied in 67 nursing home elderly subjects and 251 elderly psychiatric patients. Its possible highest score is 77 and covers 10 subscales: short-term memory, long-term memory, concentration/calculation, abstract thinking, judgement, memory registration, higher cortical functions, orientation in time, orientation in place and object naming. Test-retest correlations were between 0.827 and 0.990 for the subscale scores and 0.984 for the total score. Inter-tester kappas for each item ranged from 0.200 to 1.000 with a mean of 0.698. Concordance rates were between 50.0 and 100.0% with a mean of 87.2%. Cronbach's alphas for the items of the individual subscales ranged from 0.702 to 0.915. Inter-subscale and subscale-total correlations ranged from 0.503 to 0.820 with a mean of 0.684 and from 0.721 to 0.883, respectively. Cronbach's alpha of the subscales was 0.934. Sensitivity and specificity were 93.3% and 93.8% at the cut-off point of 57.0/57.5 for dementia. Subscale and total scores were significantly different between the demented and non-demented. The total CIDI score was significantly correlated with scores of the Blessed Dementia Rating Scale and the Korean version of the Mini-Mental State Examination.

Psychological maladjustment and academic achievement: a cross-cultural study of Japanese, Chinese, and American high school students

Psychological maladjustment and its relation to academic achievement, parental expectations, and parental satisfaction were studied in a cross-national sample of 1,386 American, 1,633 Chinese, and 1,247 Japanese eleventh-grade students. 5 indices of maladjustment included measures of stress, depressed mood, academic anxiety, aggression, and somatic complaints. Asian students reported higher levels of parental expectation and lower levels of parental satisfaction concerning academic achievement than their American peers. Nevertheless, Japanese students reported less stress, depressed mood, aggression, academic anxiety, and fewer somatic complaints than did American students. Chinese students reported less stress, academic anxiety, and aggressive feelings than their American counterparts, but did report higher frequencies of depressed mood and somatic complaints. High academic achievement as assessed by a test of mathematics was generally not associated with psychological maladjustment. The only exception was in the United States, where high achievers indicated more frequent feelings of stress than did low achievers.

Dementia among the elderly in a rural Korean community

The age-specific prevalence of dementia, its sex difference, and the relative prevalence of important types of dementia were studied in the elderly people in a Korean rural community. A two-stage approach was employed, involving screening and clinical assessment. The prevalence among individuals aged 65 and over was found to be 10.8%, with rates of 7.2% in men and 14.5% in women. The dementia was of the Alzheimer type in 60.0% of cases, multi-infarct dementia in 12.0%, mixed dementia of Alzheimer type and multi-infarct in 10.7%, alcoholic dementia in 8.0%, and others and unclassifiable in 9.3%. The prevalence of dementia of the Alzheimer type was significantly higher in women and rapidly increased with age in both sexes. The prevalence of multi-infarct dementia was not related to sex or age. Alcoholic dementia was identified only in men. These findings indicate that the prevalence of dementia in rural Korea is similar to that reported in Western countries and that the prevalence of dementia of the Alzheimer type in rural Korea is greater than that of multi-infarct dementia.

Possible superoxide radical-induced alteration of vascular reactivity in aortas from streptozotocin-treated rats

We investigated the possible involvement of the superoxide (.O2-) radical in alterations of vascular reactivity and phosphoinositide (PI) turnover in aortas from streptozotocin (STZ)-induced diabetic (4 week) rats. STZ treatment increased the maximal contractile response of the aorta to norepinephrine (NE), phenylephrine (PE) and high K+, whereas the sensitivity remained unaltered. Ca(++)-induced contractions in the presence of maximally effective concentrations of PE and K+ were also augmented after STZ treatment. The increased maximal response was associated with both decreased endothelium-dependent relaxation and increased NE-induced PI turnover. Pyrogallol (PYR), a potent .O2- generating agent, did not affect basal tone or PI turnover but, depending on concentrations, it significantly increased or decreased both the contractile response to PE and NE-induced PI turnover in control aorta. In contrast, PYR decreased NE-induced PI turnover in diabetic aorta. The malondialdehyde content of liver, serum and aorta, and of .O2- from aorta of diabetic rats, were increased significantly. Copper catalyzed oxidation of ascorbic acid resulted in contraction followed by relaxation, depending upon the ascorbic acid concentration in both control and diabetic aorta. Pretreatment with superoxide dismutase (300 U/ml) prevented the PYR-induced potentiation of the PE contraction, but not of NE+PYR-induced PI turnover in control aorta and decreased further NE+PYR-induced PI turnover in diabetic aorta. The present findings indicate that .O2- may be responsible, at least in part, for the impaired endothelial integrity, enhanced alpha adrenergic receptor-mediated PI turnover and augmented contractility, possibly through modification of calcium channels in STZ-induced short-term (4 week) diabetic rat aorta.

Pharmacological characterization of effects of verapamil and GS 283 on isolated guinea pig and rat trachealis

The pharmacological effects of verapamil and GS 283, 1-(4'-methoxybenzyl)-6,7-dihydroxy-3,4-dihydroxyisoquinoline, were investigated using isolated rat and guinea pig trachealis. Both verapamil and GS 283 inhibited carbachol-, histamine (only guinea pig)-, and high-K(+)-induced contraction in a dose-dependent manner. GS 283 acted as a weak histamine H1 and muscarinic receptor antagonist in guinea pig and rat trachealis with respective pKB values in the range of 5.60 approximately 6.12 and 5.17 approximately 5.83. On the other hand, pyrilamine and atropine showed a typical competitive antagonism on histamine (guinea pig) and on muscarinic receptors (rat trachea) with pKB values of 9.25 +/- 0.21 and 9.37 +/- 0.32, respectively. GS 283 inhibited Ca(2+)-induced contraction on guinea pig trachealis in Ca(2+)-free media. Furthermore, very high concentrations of GS 283 and verapamil completely abolished a phasic contraction induced by carbachol in Ca(2+)-free media, suggesting that verapamil and GS 283 can enter into the cytoplasm, where they may exert secondary actions on internal sites of the muscle, such as the sarcoplasmic reticulum. It is concluded that GS 283 has a Ca2+ antagonistic action along with weak histamine and muscarinic receptor blocking activity in isolated rat and guinea pig tracheal smooth muscle and its mode of action is likely inhibition of Ca2+ influx from plasma membrane and also release from the sarcoplasmic reticulum.