bluuebunny/crossref_metadata_2025 huggingface dataset:
Immune Response to Heat-Shock Protein Correlates With Induction of Insulitis in I-Eα d Transgenic NOD Mice
Authors: Shimada Akira , Kasatani Tomohiro , Takei Izumi , Maruyama Taro , Nomaguchi Hiroko , Ozawa Yukako , Ishii Masatoshi , Kasuga Akira , Tashiro Fumi , Miyazaki Jun-ichi , Yamamura Ken-ichi , Saruta Takao
Published: September 2013

To evaluate the correlation between heat-shock protein (HSP) and insulitis, we compared lymphocyte proliferative response to Mycobacterium leprae HSP65 of NOD mice with that of I-Eα d transgenic NOD (I-E+NOD) mice, which show no insulitis. We found that splenocytes from 15-week-old NOD mice showed a more marked proliferative response to HSP than did those from age-matched I-E+NOD mice (P < 0.05). We then transferred splenocytes from 12-week-old NOD mice into I-E+NOD mice to induce insulitis in the recipients and examined antibody levels against HSP. By 6 weeks posttransfer, insulitis was successfully transferred to four out of five recipients of NOD splenocytes and antibody levels against HSP were significantly higher in the NOD splenocyte-transferred group than in controls, which showed no insulitis (P < 0.01). These results suggest that immune response to HSP correlates with insulitis in NOD mice. Our results support the assertion that HSP is a useful antigen for investigating the etiology of IDDM.
Conjoint IGF-I and Insulin Infusion Shows Diverse Interactive Effects in Diabetic Rats
Authors: Tomas Frank M , Knowles Spencer E , Owens Philip C , Burgoyne Judith L , Chandler Colin S , Ballard F John
Published: September 2013

Studies in diabetic rodents and humans provide evidence that IGF-I may alleviate the diabetic state and insulin resistance to some degree. To assess the efficacy of IGFs as an adjunct treatment with insulin in diabetes, we infused IGF-I or des(1–3)IGF-I for 7 days at 0, 10.7, 26.7, and 66.8 nmol/day to streptozotocin-induced diabetic rats in conjunction with infusions of 0, 2.2, 5.6, or 14 nmol/day insulin. Both insulin and des(1–3)IGF-I increased body weight gain by 7 g/day compared with controls (1.2 g/day), but there was no additive effect. However, for nitrogen retention, the effects of des(1–3)IGF-I were additive with those of 2.2 nmol/day insulin. Des(1–3)IGF-I was two- to threefold more potent than IGF-I. At comparable rates of total nitrogen retention, carcass nitrogen retention was ∼ 35% higher with insulin than with IGF treatment, indicating a differential tissue response. IGFs did not alter carcass fat content. Des(1–3)IGF-I increased liver glycogen additively with insulin but reduced glucosuria only when given with 5.6 nmol insulin per day, indicating the possibility of a facilitatory effect, perhaps via increased insulin sensitivity. Insulin was 10- to 25-fold more potent in these glucoregulatory actions. Differential effects of the hormones were also observed for kidney, liver, and thymus weights. We conclude that IGFs and especially the more potent des(1–3)IGF-I may have a role as an adjunct to insulin therapy in diabetic patients.
Identification of Microsatellite Markers Near the Human Genes Encoding the β-cell ATP-Sensitive K+ Channel and Linkage Studies with NIDDM in Japanese
Authors: Iwasaki Naoko , Kawamura Makiko , Yamagata Kazuya , Cox Nancy J , Karibe Sachiyo , Ohgawara Hisako , Inagaki Nobuya , Seino Susumu , Bell G I , Omori Yasue
Published: September 2013

ATP-sensitive K+ (KATP) channels play a key role in stimulus-secretion coupling in pancreatic β-cells. Recent studies have shown that the β-cell KATP channel comprises two subunits: a novel member of the inwardly rectifying K+ channel family, designated BIR and expressed at highest levels in pancreatic islets, and the sulfonylurea receptor (SUR). Moreover, the genes encoding these two proteins are adjacent to one another on human chromosome 11. Genetic factors contribute to the development of NIDDM, and it seems likely that mutations in genes encoding proteins involved in insulin secretion or action may contribute to NIDDM susceptibility. The present study examined the contribution of the linked BIR and SUR genes to the development of NIDDM. These genes were localized to the same yeast artificial chromosome as two microsatellite DNA polymorphisms, D11S902 and D11S921. These microsatellite DNA polymorphisms were typed in 140 Japanese NIDDM-affected sib pairs. There was no evidence for linkage between these markers and NIDDM, suggesting that genetic variation in the BIR and SUR genes does not play a major role in susceptibility to NIDDM in Japanese.
Transfer of Diabetes in the NOD-scid Mouse by CD4 T-Cell Clones: Differential Requirement for CD8 T-Cells
Authors: Peterson Jeffrey D , Haskins Kathryn
Published: September 2013

Transfer of an interleukin 2/interferon-γ-secreting islet-specific CD4+ T-cell clone, BDC-6.9, in the immunodeficient NOD-scid mouse induces destruction of pancreatic β-cells without help from host B-cells, CD4+ T-cells, or CD8+ T-cells. However, a second islet-specific T-cell clone, BDC-2.5, showing the same cytokine profile and T-cell receptor Vβ expression as BDC-6.9 was not capable of inducing diabetes or insulitis in NOD-scid mice. Even though BDC-2.5 by itself readily induces diabetes in young unmanipulated NOD mice, cotransfer of CD8-enriched T-cells was required to induce disease in NOD-scid mice. Immunohistochemical staining of pancreatic lesions in young NOD mice receiving either BDC-2.5 or BDC-6.9 showed the presence of CD4+, CD8+, Vβ4+, and MAC-1+ cells within the infiltrate, similar to infiltrates in lesions of spontaneously diabetic female NOD mice. In contrast, NOD-scid mice that received BDC-6.9 showed only the presence of CD4+Vβ4+ T-cells and a large population of MAC-1+ cells in islet lesions. NOD-scid recipients of cotransferred BDC-2.5/CD8+ splenic T-cells showed a small population of CD4+ T-cells and a larger population of CD8+ T-cells within the infiltrated islets, whereas no infiltrate was detectable in recipients of CD8+ splenocytes or BDC-2.5 alone. Our results suggest that at least two types of islet-specific CD4+ T-cell clones play a role in diabetes pathogenesis.
Effects of Beraprost Sodium and Insulin on the Electroretinogram, Nerve Conduction, and Nerve Blood Flow in Rats with Streptozotocin-Induced Diabetes
Authors: Hotta Nigishi , Koh Naoki , Sakakibara Fumihiko , Nakamura Jiro , Hamada Yoji , Hara Tomohiro , Mori Koichi , Nakashima Eitaro , Naruse Keiko , Fukasawa Hideo , Kakuta Hironobu , Sakamoto Nobuo
Published: September 2013

The effect of a prostacyclin analog, beraprost sodium, on the electroretinogram, motor nerve conduction velocity, and nerve blood flow was determined in rats with streptozotocin-induced diabetes and was compared with the effect of insulin. Beraprost sodium (0.01 mg · kg−1 · day−1 for 8 weeks) significantly shortened the peak latency of the electroretinogram b-wave, increased tail nerve conduction velocity, and increased sciatic nerve blood flow in diabetic rats (P < 0.0003, 0.0001, and 0.0001 vs. untreated diabetic rats, respectively). This was accompanied by a significant increase in the 6-keto-prostaglandin F1α content of the thoracic aorta and a marked increase in the cAMP content of the sciatic nerve. Beraprost sodium had no effect on the sorbitol and fructose contents of the sciatic nerve and retina, but insulin (8–10 U/day) significantly reduced both parameters. These findings suggest that beraprost sodium may be useful for prevention of vascular and neural dysfunction in the retina and peripheral nerve.
Angiotensinogen Gene Polymorphisms in IDDM Patients With Diabetic Nephropathy
Authors: Tarnow Lise , Cambien François , Rossing Peter , Nielsen Flemming S , Hansen Birgitte V , Ricard Sylvain , Poirier Odette , Parving Hans-Henrik
Published: September 2013

Genotypic abnormalities of the renin-ANG system have been suggested as a risk factor for the development of diabetic nephropathy. Cleavage of angiotensinogen is the rate-limiting step in the activation of the renin-ANG system. The TT genotype of a polymorphism encoding threonine instead of methionine (M235T) has been associated not only with increased plasma angiotensinogen concentration but also with essential hypertension. In addition, a polymorphism in the angiotensinogen gene substituting methionine for threonine (T174M) has been associated with hypertension in nondiabetic populations. We studied the relationship between these polymorphisms in the angiotensinogen gene in IDDM patients with diabetic nephropathy (121 men, 74 women, age 40.9 ± 10 years, diabetes duration 27 ± 8 years). There was no difference in M235T genotype distribution between IDDM patients with diabetic nephropathy and those with normoalbuminuria: 73/97/25 (37/50/13%) vs. 67/95/23 (36/52/12%) had MM/MT/TT genotypes, respectively. No difference in distribution of T174M genotypes between nephropathic and normoalbuminuric IDDM patients was observed either: 148/44/1 (77/23/0.5%) vs. 141/42/2 (76/23/1%) had TT/TM/MM genotypes, respectively. In patients with nephropathy, systolic blood pressure was higher (161 ± 22 mmHg [mean ± SD]) in patients carrying TT genotype of the M235T angiotensinogen polymorphism as compared with patients with MM or MT genotypes (150 ± 23 mmHg; P = 0.03). We conclude that neither the M235T nor the T174M polymorphism in the angiotensinogen gene contributes to genetic susceptibility to diabetic nephropathy in white IDDM patients, whereas the TT genotype of the M235T is associated with elevated blood pressure in patients with diabetic nephropathy.
Criteria for Metabolic Control and Intervention in Diabetes
Authors: Taskinen Marja-Riitta
Published: September 2013

Guidelines for optimal management of diabetes advocate comprehensive strategies to treat all established risk factors for coronary heart disease (CHD). The targets for treatment should be optimization of glycemie control, weight reduction, lowering of elevated blood pressure, correction of lipid abnormalities, and stopping smoking. Recently, strong evidence has emerged to demonstrate that poor glycemic control is a powerful predictor for excess CHD risk (1,2). The fact that dyslipidemia and hypertension are frequent in NIDDM patients at the time of diagnosis indicates that these risk factors may cause damage for years before the actual diagnosis of NIDDM. This article highlights the current background knowledge for the guidelines of therapeutic strategies for dyslipidemias in NIDDM.
Hyperinsulinemia and Triglyceride-Rich Lipoproteins
Authors: Steiner G , Lewis GF
Published: September 2013

Hypertriglyceridemia is the most frequent form of hyperlipidemia seen in diabetes. Because hypertriglyceridemia and hyperinsulinemia often coexist in the general population and because patients with NIDDM generally are hyperinsulinemic, we have undertaken a series of in vivo studies to examine the effects of hyperinsulinemia on VLDL production. These studies showed that chronic hyperinsulinemia is accompanied by increased VLDL production and that this occurs even when plasma free fatty acid (FFA) levels have fallen. By contrast, acute hyperinsulinemia is accompanied by a reduction in VLDL production, and this reduction is, at least in part, mediated by an associated reduction in the availability of plasma FFAs as a substrate for VLDL-triglyceride (TG). The studies also raise the possibility that the difference in the dependence of VLDL production on plasma FFAs in acute versus chronic hyperinsulinemia results from an increase in hepatic lipogenic enzymes and from the availability of an alternate substrate such as fructose. The overall effect of hyperinsulinemia on VLDL production is postulated to reflect both the effect of insulin on apolipoprotein B production and the hepatic synthesis of TG from either plasma FFAs or newly made fatty acids.
Diabetic Dyslipidemia: Basic Mechanisms Underlying the Common Hypertriglyceridemia and Low HDL Cholesterol Levels
Authors: Ginsberg Henry N
Published: September 2013

Elevated levels of plasma triglyerides (TG) and reduced concentrations of HDL cholesterol are very common in patients with diabetes, particularly NIDDM. Although regulation of the plasma concentrations of VLDL, the major TG-rich lipoprotein is extremely complex, it is clear from in vivo kinetic studies that increased rates of secretion of VLDL into plasma is almost uniformly present in patients with NIDDM and hyertriglyceridemia. Recent studies at the cellular level indicate that increased fatty acid flux to the liver, also common in NIDDM (and other insulin-resistant states associated with elevated plasma TG levels), will stimulate the assembly and secretion of apoprotein (apo) B-containing lipoproteins by targeting apoB for secretion rather than intracellular degradation. Increased rates of secretion of VLDL into plasma appears to drive the exchange of TG from these lipoproteins for HDL cholesteryl ester. This exchange, which occurs in plasma, is facilitated by cholesteryl ester transfer protein, and generates a TG-enriched HDL that is a substrate for either hepatic lipase or lipoprotein lipase. When the TG in HDL is hydrolyzed, the resultant particle is smaller, and this appears to affect the binding of the major HDL protein, apoA-I. ApoA-I dissociates from the smaller, lipid-poor HDL, and the free apoA-I (molecular weight 28,000) can be filtered by the glomerulus in the kidney and most likely is degraded in renal tubular cells after reabsorption. Thus, increased free fatty acid transport in plasma, a common abnormality in insulin-resistant states, may be the underlying driving force for the two common lipid abnormalities seen in diabetes.
Quantitative and Qualitative Derangement of Apolipoprotein B-Containing Lipoproteins as a Risk Factor for Diabetic Macroangiopathy in Nonobese NIDDM Subjects
Authors: Harano Yutaka , Kageyama Aritsune , Nakao Yasuhiko , Hara Yasushi , Suzuki Masaaki , Sato Akira , Ikebuchi Motoyoshi , Shinozaki Kazuya , Tsushima Motoo
Published: September 2013

Cholesterol, triglylceride (TG), and apolipoprotein (apo) B were determined in plasma and in lipoprotein subtractions (VLDL, intermediate-density lipoproteine [IDL], LDL, and HDL) in nonobese NIDDM subjects, who were classified into well-controlled, fairly controlled, or poorly controlled states with or without macrovascular complications (macroangiopathy [MA]). The same analyses were also performed on subjects who had coronary artery disease (CAD) with stable angina pectoris (SA) or unstable angina pectoris (UA) and acute myocardial infarction, cerebrovascular disease (CVD) with atherothrombotic or lacunar infarction, and arteriosclerosis obliterane (ASO). In nonobese NIDDM subjects, the number of apoB-con-taining lipoproteins (VLDL, IDL, and LDL) increased. This alteration was more prominent in subjects with poorly or fairly controlled disease as well as in subjects with MA, but not in those with well-controlled NIDDM. Cholesterol/apoB in LDL decreased in subjects with poorly and fairly controlled diabetes or with MA and was correlated with low HDL cholesterol. The disorder is characterized by hyperbetalipoproteinemia with elevated LDL cholesterol and small dense LDL. In obese NIDDM subjects, the similar disorder was more pronounced. Glycemic control had less effect and hyperinsulinemia, if present, aggravated the lipid disorder. In those with CAD, the number of IDLs increased and the LDL fraction had the properties of small dense LDL. HDL cholesterol decreased. In those with UA, the LDL number increased without elevation of LDL cholesterol, indicating typical hyperbetalipoproteinemia. In subjects with atherothrombotic brain infarction, an increased number of small-sized LDLs was noted. In those with ASO, the number of VLDL and IDL increased with small LDL. HDL cholesterol decreased in those with CAD, cerebrovascular disease, and ASO. Since similar quantitative and qualitative alterations of apoB-containing lipoprotein have been observed in NIDDM patients as well as in those with macrovascular diseases, diabetic patients are thought to be more susceptible to the initiation and progression of atheromatous lesions in coronary, brain, and peripheral arteries.
Recent Progress in Advanced Glycation and Diabetic Vascular Disease: Role of Advanced Glycation End Product Receptors
Authors: Vlassara Helen , Bucala Richard
Published: September 2013

Advanced glycosylation end products (AGEs) form principally from the rearrangement of early glycation products, i.e., Amadori products, which produce a class of stable moieties that possess distinctive chemical cross-linking and biological properties. It has been generally believed that proteins with half-lives of longer than a few weeks are most susceptible to advanced glycosylation and that the highest levels of AGEs occur on proteins that comprise the long-lived structural components of connective tissue matrix and basement membrane.
Advanced Glycation End Products and Their Recognition by Macrophage and Macrophage-Derived Cells
Authors: Horiuchi Seikoh , Higashi Takayuki , Ikeda Kazuyoshi , Saishoji Tetsushi , Jinnouchi Yoshiteru , Sano Hiroyuki , Shibayama Rie , Sakamoto Tamami , Araki Norie
Published: September 2013

Modification of proteins by long-term incubation with glucose leads to the formation of advanced glycation end products (AGEs). AGE proteins are taken up by macrophages via the AGE receptor, which is similar to the macrophage scavenger receptor (MSR). In the present study, we compared the ligand specificity of the AGE receptor with that of MSR by three different experiments. The endocytic uptake of 125I-acetyl-LDL by RAW cells was effectively inhibited by unlabeled AGE-bovine serum albumin (BSA), whereas the inhibitory effect of acetyl-LDL on 125I-AGE-BSA was partial. Polyanions showing an effective inhibition for endocytic uptake of AGE-BSA were not always inhibitory for endocytic degradation of acetyl-LDL. These data, together with those obtained by three-dimensional fluorescence-activated cell sorter analysis, indicate that AGE proteins are recognized by more than two receptors, of which MSR is at least one. Finally, we examined whether MSR could mediate the endocytic uptake of AGE proteins by Chinese hamster ovary cells overexpressing bovine type II MSR (CHO-SRII cells). 125I-AGE-BSA underwent endocytic degradation by CHO-SRII cells, and this was effectively inhibited by unlabeled acetyl-LDL. These results clearly show that MSR mediates the endocytic uptake of AGE proteins, suggesting a new role of MSR in biological recognition of AGE in vivo.
Diabetes and Brain Ischemia
Authors: Caplan Louis R
Published: September 2013

Diabetes influences brain ischemia in a number of different ways. Diabetes causes and exacerbates macroangiopathies, increases the severity of ischemia, and increases stroke mortality. Unfortunately, few studies have examined in sufficient depth the influence of diabetes on the various vascular lesions that cause brain ischemia. These can be divided into: 1) cardiac-origin brain embolism; 2) atherosclerosis of the aorta and the large extracranial arteries—the internal carotid arteries (ICAs) and the vertebral arteries (VAs); 3) atherosclerosis of the large intracranial arteries-ICAs, anterior, middle, and posterior cerebral arteries, the VAs, and the basilar artery; 4) intracranial atheromatous branch disease of macroscopically visible branches of the intracranial arteries enumerated in 3; and 5) degenerative abnormalities such as lipohyalinosis and fibrinoid changes within penetrating artery branches visible only microscopically. The last three types of disorders all can cause deep subcortical brain infarcts, the predominant type of brain infarction found in Japan.
Asymptomatic Cerebral Small Infarcts (Lacunae), Their Risk Factors and Intellectual Disturbances
Authors: Fushimi Hisako , Inoue Toru , Yamada Yuya , Udaka Fukashi , Kameyama Masakuni
Published: September 2013

This study examines the relationship between cerebral small infarcts (lacunae) and the multiple risk factors of diabetes, age, hypertension, hyperlipidemia, and atherosclerosis in asymptomatic NIDDM patients and nondiabetic subjects by comparing brain magnetic resonance imaging (MRI) findings to these risk factors. Brain MRI was performed on 155 asymptomatic NIDDM and 39 asymptomatic nondiabetic patients, using a Shimazu SMT-150, 1.5-T instrument. Among the diabetic patients, 65 showed evidence of lacunae. The incidence of lacunae was significantly higher in older diabetic patients, but it did not significantly differ in those with or without the risk factors of atherosclerosis. We also correlated the results of a freehand cube-drawing test with the incidence of lacunae. Cube-drawing is a good indicator of spatial cognition ability supported by wide association areas of the brain. Drawing ability was tested in 56 diabetic and 39 nondiabetic subjects. Correlations of lacuna incidence with deformity in drawing and with age were high in the diabetic group. Correlation of lacunae with deformity in drawing was also significant in nondiabetic subjects. The incidence of lacunae was highly correlated with intellectual impairment.
Acquired Defects of Glycogen Synthase Activity in Cultured Human Skeletal Muscle Cells: Influence of High Glucose and Insulin Levels
Authors: Henry Robert R , Ciaraldi Theodore P , Mudaliar Sunder , Abrams Leslie , Nikoulina Svetlana E
Published: September 2013

To determine whether defects of muscle glycogen synthase (GS) activity can be acquired by exposure to elevated glucose or insulin levels, human skeletal muscle cells obtained by needle biopsy from normal control subjects were grown in culture for 4–6 weeks followed by 4 days of fusion and differentiation in media containing either normal (5.5 mmol/l glucose and 22 pmol/l insulin) or increased concentrations of glucose (20 mmol/l), insulin (30 micromol/l), or both. After fusion in normal media, acute stimulation by 33 nmol/l insulin for 1 h increased GS fractional velocity (FV) ∼ twofold (from 9.01 ± 1.26 to 16.31 ± 2.40, P < 0.05). Increasing the media glucose concentration alone to 20 mmol/l during fusion had no effect on basal FV but caused a marginal impairment of the insulin-stimulated GS response (from 8.51 ± 1.33 to 12.99 ± 1.90, P = 0.08). Increasing the media insulin concentration to 30 micromol/l during fusion at 5.5 mmol/l glucose also did not alter basal GS FV (10.61 ± 1.69%) but completely abolished the normal insulin-stimulated increase in GS activity (to 11.63 ± 1.55%, NS). The combination of high insulin (30 micromol/l) and high glucose (20 mmol/l) during fusion had no greater effect on the FV of either basal (11.66 ± 2.16%, NS) or insulin-stimulated (9.20 ± 1.80%, NS) GS activity than high insulin alone. Fusion in hyperinsulinemic media altered the kinetic parameters of GS with a near doubling of the basal Km0.1 and Vmax0.1 for uridinediphospho-glucose. Hyperinsulinemia also totally prevented the normal insulin-stimulated threefold increase in the Vmax0.1 and the 65% decrease in the A0.5 for glucose-6-phosphate. GS mRNA and protein expression, determined by RNase protection assay and immunoblotting, respectively, were unaffected by changes in media conditions. We conclude that exposure of human skeletal muscle cells primarily to high insulin induces severe insulin resistance through multiple acquired posttranslational defects, which affect both the kinetic characteristics and absolute activity of the GS enzyme.
Effects of Fasting, Refeeding, and Intraluminal Triglyceride on Proglucagon Expression in Jejunum and Ileum
Authors: Hoyt Eileen C , Lund P Kay , Winesett Douglas E , Fuller C Randall , Ghatei Mohammed A , Bloom Stephen R , Ulshen Martin H
Published: September 2013

Intestinal proglucagon is thought to be synthesized primarily by the distal gut, although the role of proglucagon-derived glucagon-like peptide I (GLP-I) as a major physiological incretin would seem to be associated with production in proximal small bowel. To better characterize the sites of production of proglucagon and GLP-I in the small intestine and evaluate nutrient regulation of small bowel proglucagon and derived peptides, we evaluated the effects of fasting for 72 h and subsequent refeeding or jejunal infusion of long-chain triglyceride (LCT) for 24 h on local expression of proglucagon in proximal and distal small bowel. Proglucagon mRNA abundance and cellular localization were determined and correlated with wet weight of bowel. In jejunum, proglucagon mRNA abundance decreased by 40% with fasting (P < 0.005) and increased with refeeding to levels similar to those of ad libitum-fed animals. In ileum, fasting resulted in a 20% decrease in proglucagon mRNA (P < 0.005); in contrast to jejunum, refeeding did not result in a significant rise in ileal proglucagon mRNA abundance from fasting values. In jejunum, signal intensity of proglucagon mRNA per cell, determined by in situ hybridization, decreased with fasting (P < 0.05) and increased with refeeding (P < 0.005) in proportion to changes in mRNA abundance. Plasma enteroglucagon and GLP-I levels correlated with jejunal proglucagon mRNA. Intrajejunal infusion of LCT increased expression of proglucagon to a greater extent in jejunum than in ileum. In conclusion, enteral nutrient intake stimulates small bowel proglucagon expression; this effect is greater in jejunum than ileum, consistent with greater intraluminal nutrient exposure and the role of jejunum as a source of the major incretin GLP-I.
Evidence for a Major Gene for Type II Diabetes and Linkage Analyses With Selected Candidate Genes in Mexican-Americans
Authors: Stern Michael P , Mitchell Braxton D , Blangero John , Reinhart Laurie , Krammerer Candace M , Harrison Chantal R , Shipman Patricia A , O'Connell Peter , Frazier Marsha L , MacCluer Jean W
Published: September 2013

We have carried out two independent family studies in low-income Mexican-Americans from San Antonio, Texas. In the first study, probands were ascertained at random without regard to any medical condition (658 examined individuals from 50 families), and in the second study, probands were subjects with type II diabetes identified in a prior epidemiological survey (523 examined individuals from 29 families). Pedigrees ranging in size from 2 to 45 family members (median 11) in the first study and from 2 to 50 family members (median 12) in the second study were examined. Diabetes was diagnosed according to World Health Organization criteria. In both sets of families, segregation analyses revealed support for a major gene with an autosomal dominant mode of inheritance influencing early age of onset of diabetes. Non-Mendelian inheritance was rejected in both data sets. Individuals with the early age of onset allele had a mean age of diabetes onset of 51 years in the first data set and 60 years in the second data set. In the first data set, the major gene accounted for ∼70% of the phenotypic variance in age of onset of diabetes, and there were no residual family effects once the major gene effect was taken into account. In the second data set, the major gene accounted for ∼50% of the phenotypic variance, and residual family effects were statistically significant. Linkage analyses were performed with 11 candidate genes, and tight linkage with diabetes was rejected for Rh blood group, glucose transporter 2, fatty acid–binding protein, tumor necrosis factor β, glucokinase, and lipoprotein lipase. A logarithm of odds (LOD) score of 0.92 at a recombination fraction of 0.05 was observed for insulin receptor substrate 1. This LOD score corresponds to a χ2 of 4.24 (P = 0.039).
Mechanisms Behind Insulin Resistance in Rat Skeletal Muscle After Oophorectomy and Additional Testosterone Treatment
Authors: Rincon Jorge , Holmäng Agneta , Wahlström Erica Odegaard , Lönnroth Peter , Björntorp Per , Zierath Juleen R , Wallberg-Henriksson Harriet
Published: September 2013

The absence of female sex hormones, as well as testosterone treatment of oophorectomized (OVX) female rats has been demonstrated to result in decreased whole-body insulin-mediated glucose uptake. The cellular mechanism behind this insulin resistance and the role of low levels of female sex hormones as a risk factor for development of peripheral insulin resistance are not yet fully clarified. We assessed the protein expression of GLUT4 and glycogen synthase, as well as insulin-induced translocation of GLUT4 to the plasma membrane, in soleus skeletal muscle from control rats, OVX rats, and OVX rats treated for 8 weeks with testosterone (OVX + T). Whole-body insulin-mediated glucose uptake assessed by the hyperinsulinemic-euglycemic clamp procedure was 25% lower in OVX rats (P < 0.001) and addition of testosterone treatment further decreased insulin-mediated glucose uptake in OVX + T rats by 48% (P < 0.001) compared with controls. GLUT4 protein expression in soleus muscles was unaltered in the OVX and OVX + T rats compared with controls. Insulin induced a 3.7-fold increase (P < 0.05) in the plasma membrane content of GLUT4 in soleus muscle from control rats, whereas plasma membrane content of GLUT4 in soleus muscle from OVX or OVX + T rats was unaltered in response to insulin. Glycogen synthase protein expression in muscle homogenates was decreased by 25% in the OVX group (P < 0.05) and by 37% in the OVX + T group (P < 0.05) when compared with the control group. Insulin receptor and tyrosine kinase activities in the basal and insulin-stimulated states did not differ between the OVX and OVX + T rats. In conclusion, the absence of female sex hormones appears to decrease insulin-mediated whole-body glucose uptake via an impaired insulin-stimulated translocation of GLUT4 to the plasma membrane and by decreased protein expression of glycogen synthase. Testosterone treatment further impairs whole-body insulin-mediated glucose uptake, presumably by additional impairment of glycogen synthase expression.
Small Doses of Subcutaneous Insulin as a Strategy for Preventing Slowly Progressive β-Cell Failure in Islet Cell Antibody—Positive Patients With Clinical Features of NIDDM
Authors: Kobayashi Tetsuro , Nakanishi Koji , Murase Toshio , Kosaka Kinori
Published: September 2013

We report a pilot study to determine the preventive effect of small doses of insulin injected subcutaneously on slowly progressive β-cell damage in islet cell antibody (ICA)-positive patients with apparent NIDDM. Ten NIDDM patients who were ICA+ were divided into two groups of five. In the insulin group (age: 51 ± 8 years [mean ± SD], sex: 3 men and 2 women), intermediate-type insulin (3–16 U/day) was given once or twice daily as a subcutaneous injection. The sulfonylurea (SU) group (age: 48 ± 11 years, sex: 3 men and 2 women) was initially treated with a SU agent. Changes in β-cell function, as indicated by serum C-peptide responses and blood glucose values during a 100-g oral glucose tolerance test, as well as ICA and GAD antibody status, were evaluated for up to 30 months in both groups. ICA status became negative in four of five patients in the insulin group. ICA status did not become negative in any of the patients in the SU group (P = 0.047 vs. insulin group). ICA status was persistently positive in two patients whose β-cell function eventually progressed to an insulin-dependent state and fluctuated in the remaining three patients. In the insulin group, GAD antibody status became negative in one of four initially GAD antibody–positive NIDDM patients. In the SU group, GAD antibody status was persistently positive in three NIDDM patients (NS vs. insulin group). The serum C-peptide response improved significantly within 6 and 12 months in the insulin group, whereas it decreased progressively in the SU group. The changes in C-peptide response were significantly different between the two groups at 6, 12, 24, and 30 months. Two-hour blood glucose and HbA1 values were unchanged in the insulin group, but they increased in the SU group. Subcutaneous small doses of insulin, resulting in a high rate of negative conversion of ICA and an improved serum C-peptide response, may be effective in treating ICA+ NIDDM patients who are at high risk for slowly progressive β-cell failure.
LY290181, an Inhibitor of Diabetes-Induced Vascular Dysfunction, Blocks Protein Kinase C—Stimulated Transcriptional Activation Through Inhibition of Transcription Factor Binding to a Phorbol Response Element
Authors: Birch Kimberly A , Heath William F , Hermeling Ronald N , Johnston Cecile M , Stramm Larry , Dell Colin , Smith Colin , Williamson Joseph R , Reifel-Miller Anne
Published: September 2013

Previous studies have shown that high glucose levels and diabetes induce an elevation in protein kinase C (PKC) activity in vascular cells and tissues susceptible to diabetic complications. In addition, PKC activation has been shown to modulate vascular cell growth, permeability, and gene expression, processes thought to be involved in the development of vascular complications. Using two in vivo model systems, we have identified a novel inhibitor of diabetic vascular dysfunction, LY290181. LY290181 prevented glucose-induced increases in blood flow and permeability in rat granulation tissue and corresponding vascular changes in the retina, sciatic nerve, and aorta of diabetic rats. Tested for its ability to inhibit PKC-regulated processes, LY290181 inhibited phorbol ester–stimulated plasminogen activator activity in a dose-dependent manner in bovine retinal endothelial cells and in human dermal fibroblasts. In addition, LY290181 inhibited phorbol ester–stimulated activation of the porcine urokinase plasminogen activator (uPA) promoter (−4600/+398) linked to the chloramphenicol acetyltransferase (CAT) reporter gene (p4660CAT). More detailed analysis of the uPA promoter revealed that LY290181 inhibited phorbol ester–stimulated activation of the uPA phorbol response element (−2458/−2349) located upstream of the thymidine kinase promoter (puPATKCAT). LY290181 appears to inhibit uPA promoter activation by blocking phorbol ester–stimulated binding of nuclear proteins to the uPA PEA3/12-O-tetradecanoylphorbol 13-acetate responsive element (TRE). These results suggest that LY290181 may inhibit diabetes-induced vascular dysfunction by inhibiting transcription factor binding to specific PKC-regulated genes involved in vascular function.
Human Obese Gene: Molecular Screening in Japanese and Asian Indian NIDDM Patients Associated With Obesity
Authors: Niki Toshiharu , Mori Hiroyuki , Tamori Yoshikazu , Kishimoto-Hashirmoto Miyako , Ueno Hirohisa , Araki Satoshi , Masugi Jiro , Sawant Nitin , Majithia Hemali R , Rais Nadeem , Hashiramoto Mitsuru , Taniguchi Hiroshi , Kasuga Masato
Published: September 2013

The mouse obese (ob) gene has recently been isolated through the positional cloning technique and has been proved to result in the obese and NIDDM phenotype in mice when mutated (Nature 372:425–432, 1994). More recently, it has been demonstrated, by experiments with recombinant ob protein, that ob gene product can cause mice, including ob/ob mice, diet-induced obesity mice, and normal mice, to lower their food intake and body weight (Science 269:540–549, 1995). To investigate the genetic and/or environmental influences underlying the development of NIDDM associated with obesity, we isolated and partially sequenced the human obese (OB) gene. The human OB gene isolated in this study encoded 167 amino acids and its open reading frame was revealed to be divided into two parts with an intermediate intron of ∼2.4 kb. Using the single-strand conformation polymorphism (SSCP) technique, we screened Japanese and Asian Indian subjects for mutations in the protein coding regions of the OB gene. A total of 75 NIDDM patients with obesity (54 Japanese and 21 Asian Indians), 40 NIDDM patients without obesity (34 Japanese and 6 Asian Indians), and 34 Japanese patients with simple obesity showed no abnormal SSCP patterns in either component of the coding sequences. These results suggested that mutations in the coding regions of the OB gene are not likely to be commonly identifiable and that there would likely be a kind of obesity-associated NIDDM not caused by mutations of the OB gene.
Association Between Insulin Secretory Pulse Frequency and Peripheral Insulin Action in NIDDM and Normal Subjects
Authors: Hunter Steven J , Atkinson A Brew , Ennis Cieran N , Sheridan Brian , Bell Patrick M
Published: September 2013

Abnormalities of both insulin secretion and insulin action occur in NIDDM. It is not clear, however, which is the primary defect. Recently, it has been suggested that the frequency of insulin pulses is an important factor regulating insulin action in normal humans. We examined the relationship between pulsatile insulin secretion and insulin action in eight NIDDM subjects and eight health matched control subjects. Insulin action was assessed prevailing fasting glucose levels before and after hype insulinemia (2-h insulin infusion at 2.0 mU · kg−1 · min−1). Pulsatility of insulin was assessed by sampling every 2 min for 90 min after an overnight fast and identifying insulin pulses using the computer program Pulsar. Fasting plasma glucose and postabsorptive endogenous glucose production were both greater in diabetic subjects compared with control subjects (10.1 ± 1.2 vs. 5.4 ± 0.1 mmol/l, P < 0.01; 11.8 ± 0.8 vs. 9.9 ± 0.4 μmol · kg−1 · min−1, P < 0.05). During the 2.0 mU insulin infusion, glucose clearance was lower in the diabetic subjects (3.6 ± 0.7 vs. 6.9 ± 0.5 ml · kg−1 · min−1), P < 0.05), whereas endogenous glucose production was suppressed to a similar degree in both groups (4.5 ± 0.8 vs. 3.6 ± 0.7 μmol · kg−1 · min−1, NS). The frequency of insulin pulses and glucose clearance were negatively correlated in both diabetic subjects (r = −0.75, P < 0.05) and normal control subjects (r = −0.82, P < 0.01). This negative correlation was also present in both groups taken together (r = −0.72, P < 0.001). There was no correlation between insulin pulse frequency and endogenous glucose production either in the fasting state or during hyperinsulinemia. We concluded that the frequency of insulin pulses and peripheral insulin sensitivity are closely linked in NIDDM and normal subjects.
Cytokine Gene Expression in Pancreatic Islet-Infiltrating Leukocytes of BB Rats: Expression of Th1 Cytokines Correlates With β-Cell Destructive Insulitis and IDDM
Authors: Rabinovutch Alex , Suarez-Pinzon Wilma , El-Sheikh Amr , Sorensen Ole , Power Robert F
Published: September 2013

Cytokines produced by islet-infiltrating mononuclear leukocytes may be involved in islet β-cell destruction and IDDM. To determine which cytokine(s) might be involved in islet β-cell destruction, we used a reverse transcriptase–polymerase chain reaction assay to compare levels of cytokine mRNA expression in mononuclear leukocytes freshly isolated from islets of four groups of BB rats aged 60–75 days: diabetes-prone (DP) rats, DP rats protected from diabetes by injection of complete Freund's adjuvant (CFA) at age 25 days, acutely diabetic rats, and diabetes-resistant (DR) rats. We found that islet mononuclear leukocyte levels of γ-interferon (IFN-γ) mRNA were significantly higher in DP and diabetic rats than in DR rats, whereas CFA-treated DP rats had similar IFN-γ mRNA levels to DR rats. Also, interleukin (IL)-2 mRNA levels tended to be higher in islet leukocytes from DP and diabetic rats than from DR rats. Tumor necrosis factor-ɑ, IL-4, and IL-10 mRNA levels were not significantly different in islet leukocytes from the four groups of rats. These findings suggest that production of T-helper 1 (Th1)-type cytokines, IFN-γ and IL-2, by islet-infiltrating cells in BB rats is associated with β-cell destruction and IDDM development.
The Insulin-Induced Increase of Guanosine-3′,5′-Cyclic Monophosphate in Human Platelets Is Mediated by Nitric Oxide
Authors: Trovati Mariella , Paola Massucco , Mattiello Luigi , Piretto Valentina , Mularoni Elena , Anfossi Giovanni
Published: September 2013

To investigate whether the insulin-induced increase of guanosine-3ʹ,5ʹ-cyclic monophosphate (cGMP) in human platelets is mediated by nitric oxide or is influenced by the nitric oxide precursor L-arginine, we measured cGMP in platelet-rich plasma obtained from healthy volunteers incubated for 3 min with human recombinant insulin (0, 240, 480, 960, and 1,920 pmol/l) both with and without 1) a 20-min incubation with the nitric oxide–synthase inhibitor NG-monomethyl-L-arginine (L-NMMA) (50, 70, 100, and 1,000 μmol/l; n = 5 for each dose) and 2) a 20-min incubation with the nitric oxide precursor L-arginine (300 μmol/l; n = 6). In a first set of experiments, insulin induced a dose-dependent cGMP increase, from 9.8 ± 0.8 to 45.6 ± 5.5 pmol/l09 platelets (P = 0.0001); in the presence of 1 mmol/l L-NMMA, this increase was blunted, cGMP being 8.9 ± 1.4 and 11.1 ± 2.2 pmol/l09 platelets at 0 and 1,920 pmol/l insulin, respectively (NS). In the experiments with 70 and 100 μmol/l L-NMMA, the insulin effect on cGMP was inhibited, whereas 50 μmol/l L-NMMA did not blunt this insulin effect. In another set of experiments carried out to investigate the effects of L-arginine, insulin induced a dose-dependent cGMP increase, from 23.6 ± 6.9 to 59.0 ± 12.0 pmol/l09 platelets (P = 0.0001); with L-arginine, basal cGMP values increased to 35.5 ± 6.6 pmol/l09 platelets (P = 0.05), and insulin maintained its ability to enhance dose-dependently cGMP values, which rose to 76.8 ± 19.4 pmol/l09 platelets (P = 0.003). This study carried out in human platelets demonstrates that the cGMP increase induced by insulin, which accounts for the antiaggregating effect of the hormone, is mediated by nitric oxide.
Multiple Lipoprotein Abnormalities in Type I Diabetic Patients With Renal Disease
Authors: Groop Per-Henrik , Elliott Tom , Friedman Rogerio , Viberti GianCarlo , Ekstrand Agneta , Franssila Anja-Kallunki , Taskinen Marja-Riitta
Published: September 2013

The aim of this study was to characterize abnormalities of triglyceride-rich apolipoprotein (apo) B-containing lipoproteins in type I diabetic patients with elevated albumin excretion rates (AERs). Sixty-four patients (31 men, 33 women) with normoalbuminuria (AER <20 jjtg/min), 52 (35 men, 17 women) with microalbuminuria (AER 20–200 μg/min), and 37 (17 men, 20 women) with albuminuria (AER >200 (μg/min) and 56 healthy control subjects matched for age and body weight were studied. The major finding was increased mass concentrations of the highly atherogenic intermediate-density lipoprotein fraction in patients with microalbuminuria (P < 0.05) and albuminuria (P <0.05), compared with those with normoalbuminuria. Triglyceride, free cholesterol, cholesterol ester, and phospholipid concentrations in the VLDL, intermediate-density lipoprotein, and LDL (P <0.05-0.01), as well as total cholesterol, total triglyceride, and apoB concentrations were higher in patients with renal disease than in those without. Notably, there were no differences between patients with microalbuminuria and albuminuria. Only minor compositional changes could be detected. Postheparin plasma lipoprotein lipase (LPL) activities were identical, but hepatic lipase activities were higher in microalbuminuric and albuminuric patients than in normoalbuminuric patients (P < 0.01). LPL activity and VLDL1 (8f60–400) (r = −0.528; P < 0.001) and VLDL2 (8f20–60) mass concentrations (r = −0.471; P < 0.001) were negatively related. In conclusion, in type I diabetic patients with early renal disease, there are multiple lipoprotein changes, which are potentially atherogenic and may contribute to the excess of macrovascular complications seen in such patients.
Low Insulin Secretion and High Fasting Insulin and C-Peptide Levels Predict Increased Visceral Adiposity: 5-Year Follow-Up Among Initially Nondiabetic Japanese-American Men
Authors: Boyko Edward J , Leonetti Donna L , Bergstrom Richard W , Newell-Morris Laura , Fujimoto Wilfred Y
Published: September 2013

Insulin resistance and hyperinsulinemia occur more frequently in subjects with greater visceral adiposity, but it is not known whether these metabolic abnormalities precede or follow visceral fat accumulation. We prospectively studied the development of visceral adiposity in relation to fasting and stimulated insulin and C-peptide levels. We followed 137 nondiabetic, second-generation Japanese-American men for changes in visceral adiposity over 5 years. Intra-abdominal fat (IAF) area (square centimeters) was measured at the umbilicus by computed tomography at baseline and after 5 years. Plasma insulin and C-peptide levels were measured after an overnight fast and during an oral glucose tolerance test, β-cell function was measured by the insulin secretion ratio (30–0 min plasma insulin difference)/(30–0 min plasma glucose difference). After adjustment for baseline IAF in multiple linear regression models, baseline fasting insulin (coefficient = 0.241, P = 0.048) and C-peptide (coefficient = 38.538, P < 0.001) levels were positively correlated, while the baseline insulin secretion ratio was negatively correlated with IAF change (coefficient = −0.099, P = 0.027). With IAF difference coded as a dichotomous variable (<0 cm2 vs. ≤0 cm2), the highest versus lowest tertile of baseline fasting insulin (odds ratio [OR] = 3.0, 95% CI 1.0–9.7) and fasting C-peptide (OR = 8.1, 95% CI 2.4–26.8) levels and the lowest versus highest tertile of the insulin secretion ratio (OR = 3.3, 95% CI 1.0–10.0) were associated with higher odds of IAF gain. Greater insulin resistance and reduced insulin secretion precede visceral fat accumulation in nondiabetic Japanese-American men.
Evidence for a Circadian Rhythm of Insulin Sensitivity in Patients With NIDDM Caused by Cyclic Changes in Hepatic Glucose Production
Authors: Boden Guenther , Chen Xinhua , Urbain Jean Luc
Published: September 2013

Diurnal variation in insulin sensitivity in patients with NIDDM has long been suspected but has been difficult to document mainly because of the interdependence of changes in glucose and insulin. Stable serum insulin levels during hyperglycemic clamping in patients with NIDDM in the present study provided the opportunity to examine changes in insulin sensitivity unaffected by changes in blood glucose and insulin concentrations. Six patients with NIDDM (four men and two women, BMI 33.9 ± 2.5) underwent hyperglycemic (11.1 mmol/l, ∼200 mg/dl) clamping for 72 h. Measured were serum insulin, free fatty acid (FFA), cortisol, and growth hormone concentrations and rates of insulin secretion, insulin clearance, and glucose infusion rate (GIR) needed to maintain hyperglycemia. In addition, five patients (three men and two women, BMI 32.6 ± 0.6) underwent hyperglycemic clamping for 24 h with hourly determinations of hepatic glucose production (HGP) and glucose disappearance rates (GRd). GIR, reflecting insulin sensitivity, changed rhythmically with a cycle duration of 22.9 ± 1.4 h and an amplitude of 47.8 ± 11.2%. GIR was lowest at 8:31 a.m. (±52 min) and highest at 7:04 p.m. (±58 min). Circadian changes in GIR were completely accounted for by changes in HGP, while GRd remained unchanged. Plasma levels of FFAs and cortisol also exhibited circadian fluctuations, and their blood levels correlated negatively with GIR (r = −0.72 and −0.64, respectively). We concluded that insulin sensitivity in patients with NIDDM changed with circadian (∼24 h) rhythmicity (decreasing during the night and increasing during the day). These changes were unrelated to blood levels of glucose and insulin, insulin clearance, exercise, food intake, and sleep. They were caused by circadian changes in HGP, which in turn were closely correlated with circadian changes in blood FFA and cortisol levels. We believe that recognition of these circadian changes has implications for the diagnosis and the treatment of patients with NIDDM.