bluuebunny/crossref_metadata_2025 huggingface dataset:
Lactate Production in Pancreatic Islets
Authors: Tamarit-Rodriguez Jorge , Idahl Lars-Åke , Giné Elena , Alcazar Oscar , Sehlin Janove
Published: September 2013

Lactate production, glucose utilization, glucose oxidation, and insulin release were studied in islets from rat and ob/ob mice. Lactate was determined with a highly sensitive method, based on esterification, subsequent separation, and quantitation with high-performance liquid chromatography. There was a significant lactate production in the absence of glucose, which increased with glucose concentrations up to 3 mmol/l, reaching its half-maximal rate in the presence of 0.2–1.0 mmol/l glucose in both species. Glucose utilization displayed a wider glucose concentration dependence, with a KQ 5 value between 3 and 10 mmol/l glucose. The rates of glucose utilization and lactate production were similar at 3 mmol/l glucose in rat islets and at about 6 mmol/l glucose in ob/ob mice islets. Saturation of lactate production at low glucose concentrations is probably contributing to the observed preferential stimulation of oxidative metabolism at higher concentrations. D-Mannoheptulose caused a marked inhibition of glucose utilization and glucose oxidation at 20 mmol/l glucose in islets from rat or ob/ob mice, as would be expected from a competitive inhibition of glucokinase. By contrast, D-mannoheptulose reduced only marginally the islet metabolism at 3 mmol/l glucose, which is consistent with an effective mannoheptulose-induced inhibition of the glucokinase-dependent, minor part of glucose phosphorylation at this low glucose concentration.
Mutation P291fsinsC in the Transcription Factor Hepatocyte Nuclear Factor-1α is Dominant Negative
Authors: Yamagata Kazuya , Yang Qin , Yamamoto Koji , Iwahashi Hiromi , Miyagawa Jun-ichiro , Okita Kohei , Yoshiuchi Issei , Miyazaki Jun-ichi , Noguchi Tamio , Nakajima Hiromu , Namba Mitsuyoshi , Hanafusa Toshiaki , Matsuzawa Yuji
Published: September 2013

The type 3 form of maturity-onset diabetes of the young (M0DY3) results from mutations in the gene encoding the transcription factor, hepatocyte nuclear factor-1α (HNF-1α). The mechanism by which mutations in only one allele of the HNF-1α gene impair pancreatic β-cell function is unclear. The functional form of HNF-1α is a dimer—either a homodimer or a heterodimer with the structurally related protein HNF-1β—that binds to and activates transcription of the genes whose expression it regulates. HNF-1α is composed of three functional domains: an amino-terminal dimerization domain (amino acids 1–32), a DNA-binding domain with POU-like and homeodomain-like motifs (amino acids 150–280), and a COOH-terminal transactivation domain (amino acids 281–631). Because the dimerization domain is intact in many of the mutant forms of HNF-1α found in MODY subjects, these mutant proteins may impair pancreatic β-cell function by forming nonproductive dimers with wild-type protein, thereby inhibiting its activity; that is, they are dominant-negative mutations. This hypothesis was tested by comparing the functional properties of the frameshift mutation P291fsinsC, the most common mutation identified to date in MODY3 patients, and wild-type HNF-1α. P291fsinsC-HNF-1α showed no transcriptional transactivation activity in HeLa cells, which lack endogenous HNF-1α. Overexpression of P291fsinsC-HNF-1α in MIN6 cells, a mouse β-cell line, resulted in an ∼40% inhibition of the endogenous HNF1α activity in a dosage-dependent manner. Furthermore, heterodimer formation between wild-type and P291fsinsC mutant proteins were observed by electrophoretic mobility shift assay. These data suggest that the P291fsinsC mutation in HNF-1α functions as a dominant-negative mutation. However, other mutations, such as those in the promoter region and dimerization domain, may represent loss of function mutations. Thus mutations in the HNF-1α gene may lead to β-cell dysfunction by two different mechanisms.
Insulin Receptor Signaling in the β-Cell Influences Insulin Gene Expression and Insulin Content: Evidence for Autocrine β-Cell Regulation
Authors: Xu Gang G , Rothenberg Paul L
Published: September 2013

The insulin receptor (IR) is expressed by insulin-secreting β-Cells, but its cellular function is unknown. We transfected βTC6-F7 β-Cells with cDNAs encoding either wild-type or mutant kinase-inactive (A/K1018) IRs, and by fluorescence-activated cell sorting generated polyclonal β-cell lines that overexpressed each receptor type at levels two- to fourfold higher than the parental cells. β-Cells overexpressing wild-type IRs had a proportional increase in insulin-stimulated tyrosine kinase activity; no change occurred in β-Cells expressing the mutant IR. We observed a threefold increase in cellular insulin content in β-Cells that overexpressed the wildtype IR, as determined by radioimmunoassay. This increase occurred despite a fivefold elevated rate of both basal and 10 mmol/l glucose-induced insulin secretion. Fractional insulin secretion (percentage of total cell insulin releasable at 10 mmol/l glucose) was unchanged in β-Cells overexpressing the wild-type IR compared with the parental β-cell line. Insulin content and insulin secretion were unaffected by overexpression of kinase-inactive IRs. Steady-state insulin mRNA levels were elevated twofold in the β-Cells overexpressing the wild-type IR and unchanged in the β-Cells expressing the kinase-inactive receptor, as determined by Northern blot analysis. The rate of insulin mRNA degradation measured in the presence of 5 μg/ml actinomycin D was not significantly affected in either cell line. In the absence of glucose, the basal level of (pro)insulin biosynthesis in the β-Cells overexpressing the wild-type IR increased significantly (61%) compared with the pcells transfected with the kinase-inactive IR. These data indicate that IR signaling can regulate insulin gene transcription and can modulate the steady-state insulin content of β-Cells.
Cloning of the Promoters for the β-Cell ATP-Sensitive K-Channel Subunits Kir6.2 and SUR1
Authors: Ashfield Rebecca , Ashcroft Stephen J H
Published: September 2013

The β-cell ATP-sensitive potassium channel (K-ATP channel), which regulates insulin secretion, is composed of two types of subunits: I) a sulfonylurea receptor (SUR1) and £) an inwardly rectifying potassium channel (Kir6.2). We have isolated clones containing 5′-flanking DNA for both genes by hybridization screening of a human genomic library. Sequencing of over one kilobase of each upstream region has revealed that the putative promoters are G + C rich, with no TATA box. Several E-boxes and potential Spl sites are present in both promoters, and the Kir6.2 upstream region contains an Alu repeat. Using a luciferase reporter gene in transient transfection assays, we demonstrate that the upstream DNA contains promoters that are active in the β-cell lines HIT T15 and MIN6. The promoters are completely inactive in the fibroblast cell line COS7 but show some activity in HepG2 (liver) and HEK293 (epithelial) cell lines. Deletion analysis suggests that a short (173-base pair [bp]) fragment of SUR1 5′-flanking sequence is sufficient for maximal promoter activity. In contrast, over 900 bp of Kir6.2 5′ sequence are required for similar high level expression, and deletion of the Alu repeat results in an increase in promoter activity.
NIDDM Genes in Mice: Deleterious Synergism by Both Parental Genomes Contributes to Diabetogenic Thresholds
Authors: Leiter Edward H , Reifsnyder Peter C , Flurkey Kevin , Partke Hans-Joachim , Junger Erika , Herberg Lieselotte
Published: September 2013

We used mouse genetics to model how polygenic thresholds for the transition from impaired glucose tolerance (IGT) to NIDDM are reached. NON/Lt and NZO/Hl are inbred mouse strains selected for IGT and polygenic obesity, respectively. Their Fl male progeny consistently developed NIDDM. Genetic analysis of F2 males from both cross directions identified an NON-derived diabetogenic locus, Nidd 1, on chromosome (Chr) 4 near the leptin receptor. This locus was associated with reduced plasma insulin, increased non-fasted blood glucose, and lower body weight. Another NON-derived diabetogenic locus on Chr 18 (Nidd2) that controls blood glucose was identified. An NZO-derived diabetogenic region on Chr 11 (Nidd3), possibly comprising two separate loci, reduced ability to sustain elevated plasma insulin and significantly reduced weight gain over time. Thus, the diabetogenic synergism between genetic loci from strains separately exhibiting subthreshold defects perturbing glucose homeostasis underscores the likely complexity of the inheritance of obesity-associated forms of NIDDM in humans.
Matrix Metalloproteinase Expression in Human Retinal Microvascular Cells
Authors: Grant Maria B , Caballero Sergio , Tarnuzzer Roy W , Bass Kathryn E , Ljubimov Alexander V , Spoerri Polyxenie E , Galardy Richard E
Published: September 2013

The degree of hyperglycemia correlates with the development of diabetic retinopathy. We investigated the effect of glucose on the expression of matrix metalloproteinase (MMP)-2 and MMP-9 (72-kDa and 92-kDa type IV collagenases, respectively) by human retinal microvascular endothelial cells (HRECs). Cultured HRECs from nondiabetic and diabetic donors were exposed to 5 or 30 mmol/l glucose. Using gelatin zymography, conditioned medium (CM) from all cultures revealed a gelatinolytic band migrating at 65 kDa (representing the proform of MMP-2 that runs at 72 kDa under reducing conditions). This band was unchanged by glucose exposure or the disease state of the donors. CM from nondiabetic HREC cultures demonstrated an additional proteolytic activity migrating at 90 kDa when cells were exposed to 30 mmol/l glucose, but not when they were exposed to 5 mmol/l glucose. This same activity was seen in CM from HREC cultures of diabetic origin in the presence of both 5 and 30 mmol/l glucose. Western analysis confirmed the identity of the 65-kDa band as MMP-2. The anomalous activity at 90 kDa was identified as MMP-2 associated and co-migrating with a fibronectin fragment. Competition-based reverse transcription-polymerase chain reaction revealed that nondiabetic and diabetic HRECs expressed constitutively mRNA for MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, and fibronectin. After exposure to 5 or 30 mmol/l glucose, no changes were detected in mRNA levels in MMP-2 or MMP-9, their inhibitors TIMP-1 and TIMP-2, or fibronectin in either nondiabetic or diabetic HREC cultures. These results support the notion that modulation of MMP function by extracellular matrix components occurs in response to glucose and may be relevant to the development of diabetic retinopathy.
Altered Activities of Transcription Factors and Their Related Gene Expression in Cardiac Tissues of Diabetic Rats
Authors: Nishio Yoshihiko , Kashiwagi Atsunori , Taki Hideki , Shinozaki Kazuya , Maeno Yasuhiro , Kojima Hideto , Maegawa Hiroshi , Haneda Masakazu , Hidaka Hideki , Yasuda Hitoshi , Horiike Kihachiro , Kikkawa Ryuichi
Published: September 2013

Gene regulation in the cardiovascular tissues of diabetic subjects has been reported to be altered. To examine abnormal activities in transcription factors as a possible cause of this altered gene regulation, we studied the activity of two redox-sensitive transcription factors— nuclear factor-KB (NF-KB) and activating protein-1 (AP-1)—and the change in the mRNA content of heme oxygenase-1, which is regulated by these transcription factors in the cardiac tissues of rats with streptozotocin-induced diabetes. Increased activity of NF-KB and AP-1 but not nuclear transcription-activating factor, as determined by an electrophoretic mobility shift assay, was found in the hearts of 4-week diabetic rats. Glycemic control by a subcutaneous injection of insulin prevented these diabetes-induced changes in transcription factor activity. In accordance with these changes, the mRNA content of heme oxygenase-1 was increased fourfold in 4-week diabetic rats and threefold in 24-week diabetic rats as compared with control rats (P < 0.01 and P < 0.05, respectively). Insulin treatment also consistently prevented changes in the mRNA content of heme oxygenase-1. The oral administration of an antioxidant, probucol, to these diabetic rats partially prevented the elevation of the activity of both NFKB and AP-1, and normalized the mRNA content of heme oxygenase-1 without producing any change in the plasma glucose concentration. These results suggest that elevated oxidative stress is involved in the activation of the transcription factors NF-KB and AP-1 in the cardiac tissues of diabetic rats, and that these abnormal activities of transcription factors could be associated with the altered gene regulation observed in the cardiovascular tissues of diabetic rats.
Peroxisome Proliferator-Activated Receptor-γ Agonist, Rosiglitazone, Protects Against Nephropathy and Pancreatic Islet Abnormalities in Zucker Fatty Rats
Authors: Buckingham Robin E , Al-Barazanji Kamal A , Toseland C D Nigel , Slaughter Mark , Connor Susan C , West Andrew , Bond Brian , Turner Nicholas C , Clapham John C
Published: September 2013

Rosiglitazone (BRL 49653), a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist and potent insulin action-enhancing agent, was given in the diet (50 umol/kg of diet) to male Zucker rats ages 6–7 weeks for 9 months (prevention group). In this treatment mode, rosiglitazone prolonged the time to onset of proteinuria from 3 to 6 months and markedly reduced the rate of its subsequent progression. Progression was also retarded when treatment was commenced (intervention group) after proteinuria had become established (4 months; ages 24–25 weeks). In either treatment mode, rosiglitazone normalized urinary N-acetyl-β-D-glucosaminidase activity, a marker for renal proximal tubular damage, and ameliorated the rise in systolic blood pressure that occurred coincidentally with the development of proteinuria in Zucker fatty control rats. The renal protective action of rosiglitazone was verified morphologically. Thus in the prevention group there was an absence of the various indexes of chronic nephropathy that were prominent in the Zucker fatty control group, namely, glomerulosclerosis, dilated tubules containing proteinaceous casts, a loss of functional microvilli on the tubular epithelium, and varying degrees of chronic interstitial nephritis. An intermediate pathology was observed in the intervention group. Also, pancreatic islet hyperplasia, ultrastructural evidence of (β-cell work hypertrophy, and derangement of α-cell distribution within the islet were prominent features of Zucker fatty control rats, but these adaptive changes were ameliorated (intervention group) or prevented (prevention group) by rosiglitazone treatment. These data demonstrate that treatment of Zucker fatty rats with rosiglitazone produced substantial protection over a prolonged period against the development and progression of renal injury and the adaptive changes to pancreatic islet morphology caused by sustained hyperinsulinemia.
Increased Collagen Cross-Linkages in Experimental Diabetes: Reversal by β-Aminopropionitrile and D-Penicillamine
Authors: Chang Katherine , Uitto Jouni , Rowold Edwin A , Grant Gregory A , Kilo Charles , Williamson Joseph R
Published: September 2013

The effects of diabetes on collagen cross-link formation and solubility were investigated in granulation tissue collagen induced by polyester fabric implanted subcutaneously in rats at the same time diabetes was produced by injection of streptozotocin. Thus, all the collagen analyzed was formed in a diabetic milieu. Ten days later the implants were removed and the total collagen content as well as the fraction soluble in 0.5 M acetic acid was determined. Predominantly type I collagen accumulated in the implants. Total collagen content was the same in diabetics and controls; however, the acid-soluble fraction in diabetic animals was only half that of controls (8.5% and 17.7%, respectively), and the ratio of β chains to a chains in the acid-soluble fraction was higher in diabetics (0.89) than in controls (0.69). In animals treated with β-aminopropionitrile or D-penicillamine the acid-soluble fraction of collagen from diabetics equaled that from controls. These observations indicate that both intramolecular and intermolecular cross-links are increased in type I collagen from diabetic animals. Since these cross-links interfere with degradation of collagen by collagenase, they may contribute to accelerated intimal sclerosis of arteries and to capillary basement membrane thickening in diabetes.
Immunochemical Studies on the Insulin-degrading Enzyme from Pig and Rat Skeletal Muscle
Authors: Yokono Koichi , Imamura Yoshimichi , Shii Kozui , Mizuno Nobuhiko , Sakai Hideyo , Baba Shigeaki
Published: September 2013

Insulin-degrading enzyme (IDE), which proteolytically degraded insulin with a high degree of specificity, was purified from pig skeletal muscle by ammonium sulfate precipitation, chromatography on Bio-Gel P-200 and DEAE-cellulose, and finally rechromatography on Sephadex G-200 (rechromatography fraction). The enzyme was also purified by affinity chromatography (affinity fraction). Both fractions migrated as a single component at the same position on polyacrylamidegel disc electrophoresis. Antiserum against pig muscle IDE was obtained by immunization of rabbits using the rechromatography fraction. By means of antiserum, it was shown that pig muscle IDE (affinity fraction), rat muscle cytosol-, and membrane-IDE gave a precipitin band of identity in Ouchterlony double-immunodiffusion systems. Quantitative immunoprecipitin data demonstrated that the antiserum inhibited the activities of the above three IDEs compared with normal rabbit serum. These data suggest that the insulindegrading enzyme from porcine muscle and that from rat muscle have similar immunologic properties.

The antiserum described here should be a useful tool for the examination of subcellular distribution and the quantitative analysis of insulin-degrading enzyme. It may also be helpful in determining the physiologic Significance Of IDE.
Glycoprotein-like Large Glucagon Immunoreactive Species in Extracts of the Fetal Bovine Pancreas
Authors: Tung A K , Cockburn E , Siu K P
Published: September 2013

Large glucagon immunoreactive substances, extracted from the fetal bovine pancreas and separated by gel filtration in the presence of 6 M guanidiniumhydrochloride, were submitted to lectin-sepharose affinity column chromatography. Gel-filtered peak I (∼45 KΔ) and peak II (∼10 Δ) interacted biospecifically with concanavalin-A- and wheat-germ-lectin-sepharoses, suggesting glycoproteins as possible constituents of large glucagon immunoreactive substances in extracts of the fetal bovine pancreas. The glucagon-like immunochemical identity of the lectinsepharose-bound substances was further substantiated by binding to antiglucagon antibodies-sepharose and by characteristic proportional dilutions in the glucagon radioimmunoassay.
Restoration of Prostacyclin/Thromboxane A2 Balance in the Diabetic Rat: Influence of Dietary Vitamin E
Authors: Karpen C W , Pritchard K A , Arnold J H , Cornwell D G , Panganamala R V
Published: September 2013

The effect of dietary vitamin E on the synthesis of platelet thromboxane A2 (TxA2) and vascular prostacyclin (PGI2) in streptozotocin-induced diabetic rats was investigated. Thrombin-induced platelet TxA2 synthesis in diabetic rats was significantly elevated, whereas no significant difference was found with collagen-induced synthesis. Arterial PGI2 production was significantly decreased in diabetic rats. Serum lipid peroxide levels were elevated, and platelet vitamin E levels decreased in diabetic rats. When the diabetic rats were maintained on a high vitamin E diet for 2-3 mo, thrombin-induced platelet TxA2, vascular PGI2, and lipid peroxides were restored to levels found in nondiabetic rats. Platelets from diabetic rats maintained on a high vitamin E diet synthesized significantly less collagen-induced TxA2 than platelets from nondietary vitamin E-supplemented diabetic rats or nondiabetic controls.
The Effect of Graded Doses of Insulin on Total Glucose Uptake, Glucose Oxidation, and Glucose Storage in Man
Authors: Thiebaud Daniel , Jacot Eric , Defronzo Ralph A , Maeder Evelyne , Jequier Eric , Felber Jean-Pierre
Published: September 2013

The dose-response relationship between plasma insulin concentration and total glucose uptake, glucose oxidation, and glucose storage was examined in 22 healthy young volunteers by employing the euglycemic insulin clamp technique in combination with indirect calorimetry. Insulin was infused at five rates to achieve steady-state hyperinsulinemic plateaus of 62 ± 4, 103 ± 5, 170 ± 10, 423 ± 16, and 1132 ± 47 μU/ml. With increasing plasma insulin concentrations within the physiologic range, there was a linear increase in glucose uptake with a half maximally effective insulin concentration of 72 μU/ml. Glucose uptake by all tissues of the body reached 80% of its maximum value (12.6 mg/kg · min) at a plasma insulin concentration of ∼200 μU/ml. In contrast to total glucose uptake, glucose oxidation plateaued more quickly, achieved a maximum rate of only 4.0 mg/kg · min, and displayed a lower half maximally effective insulin concentration of 40 μU/ml. The increase in glucose uptake with progressively increasing plasma insulin levels was primarily the result of an increase in glucose storage, with a half maximally effective insulin concentration of 105 μU/ml and maximum rate of 8.7 mg/kg · min. Glucose storage represented over 60–70% of total glucose uptake at all insulin concentrations. After achieving maximum rates of insulin-mediated glucose uptake (plasma insulin concentration = 1132 μU/ml), hyperglycemia (+125 mg/dl) was superimposed on hyperinsulinemia to further enhance glucose transport. Under these conditions, total glucose uptake (32.5 mg/kg · min, P < 0.001) was markedly augmented but no significant increase in glucose oxidation was observed. These results indicate a true saturation of the glucose oxidation pathway. With pro-gressively increasing doses of insulin, the glucose storage represents the major route of glucose disposal.
Islet Electrical Pacemaker Response to Alpha-Adrenergic Stimulation
Authors: Cook Daniel L , Perara Eve
Published: September 2013

To characterize the pancreatic islet cell response to adrenergic stimulation, membrane potentials have been recorded from isolated, perifused mouse islets of Langerhans exposed to a steady glucose level of 200 mg/dl. Various doses of epinephrine HCI from 5 to 10,000 nM have been applied for 10-15-min test periods separated by 10-15-min control periods. Epinephrine produced a dose-dependent suppression of glucose-induced membrane electrical activity. Adding epinephrine (50-100 nM) reduced the plateau fraction (the fraction of each plateau/silent phase cycle spent in the plateau phase) from 0.41 ± 0.03 (x¯ ± SEM, N = 13) to 0.28 ± 0.08 (n = 5, P = 0.05) and more markedly reduced the plateau frequency from 2.56 ± 0.32 (n = 13) to 0.80 ± 0.23 min−1 (n = 5, P < 0.02). Adding 10- and 100-fold higher concentrations of epinephrine had little additional effect, indicating saturation of the epinephrine effect. There was no effect of epinephrine on the membrane potential levels of the plateau and silent phase after a new steady state was achieved and no effect on the amplitude and waveform of the rapid spikes.

The pattern of inhibition of the plateau/silent phase cycles by epinephrine is qualitatively different from the pattern seen during inhibition of electrical activity by reducing glucose level. This suggests that the electrical rhythm is controlled by more than one pathway. The persistence of electrical activity at very high levels of epinephrine (to 10,000 nM) suggests that electrical activity and, therefore, Ca2+ uptake can exist in the absence of insulin release.
No Evidence for Linkage Between Diabetes and the Kidd Marker
Authors: Dunsworth T S , Rich S S , Swanson J , Barbosa J
Published: September 2013

We have studied linkage analysis between the Kidd (Jk) red blood cell marker locus and insulin-dependent diabetes mellitus (IDD) in an attempt to confirm the preliminary report of Hodge et al. One hundred thirtytwo families with one IDD proband (67 simplex and 65 multiplex families) were analyzed using the LIPED computer program and assuming three genetic models (autosomal recessive, additive, and dominant) with parameters similar to those used by Hodge et al. The lod scores at zero recombination were −18.51, −11.62, and −6.03 for the recessive, additive, and dominant models, respectively. These results constitute significant evidence against tight linkage between Kidd and IDD, while providing no evidence for looser linkage, and are in contrast with the positive lod scores found by Hodge et al. in a different population.
Increased Peripheral Insulin Sensitivity and Muscle Mitochondrial Enzymes but Unchanged Blood Glucose Control in Type I Diabetics After Physical Training
Authors: Wallberg-Henriksson H , Gunnarsson R , Henriksson J , Defronzo R , Felig P , Östman J , Wahren J
Published: September 2013

Nine male, insulin-dependent diabetic patients participated in a 16-wk training program consisting of 1 h of jogging, running, ball games, and gymnastics, performed 2-3 times/wk. The training resulted in an 8% increase of maximal oxygen uptake (P < 0.01). Insulin sensitivity as determined by the insulin clamp technique increased 20% (P < 0.05). Glycosylated hemoglobin showed no change (10.4 ± 0.7% versus 11.3 ± 0.5%), 24-h urinary glucose excretion was not reduced, and home-monitored urine tests were unchanged. The frequency of hypoglycemie attacks did not change during the training period and body weight remained constant. There was a 14% fall in plasma cholesterol (P < 0.01) and a rise in the proportion of HDL-cholesterol from 24 ± 2% to 30 ± 3% (P < 0.01).

Thigh muscle oxidative capacity increased, as indicated by a 24% increase in succinate dehydrogenase activity (P < 0.05). The number of capillaries/muscle fiber increased 15% (P < 0.01). However, as the mean muscle fiber cross-sectional area increased to a similar extent (11%, P < 0.05), capillary density (cap × mm−2) was unchanged.

In conclusion, this study demonstrates that physical training in insulin-dependent diabetics results in increased peripheral insulin sensitivity, a rise in muscle mitochondrial enzyme activities, decreased total plasma cholesterol levels, and unchanged blood glucose control. The findings suggest that in the absence of efforts to alter dietary regulation and insulin administration, physical training consisting of 2-3 weekly bouts of moderate exercise may not of itself improve blood glucose control in type I diabetes.
Predictive Value of Gastric Parietal Cell Autoantibodies as a Marker for Gastric and Hematologic Abnormalities Associated with Insulin-dependent Diabetes
Authors: Riley William J , Toskes Phillip P , MaClaren Noel K , Silverstein Janet H
Published: September 2013

The frequency and significance of gastric parietal cell autoimmunity was assessed in 771 patients with insulin-dependent diabetes (IDD) of onset before 30 yr of age. Gastric parietal autoantibodies (PCA) were found 4 times more frequently in the patients with IDD (9%) than among 600 matched nondiabetic controls (2%). Caucasian female patients with IDD had PCA twice as frequently as male patients. Thyroid microsomal autoantibodies were more frequent in patients with IDD and PCA, than in those with IDD alone (Caucasian 46% versus 18%, black 25% versus 2.5%). A history of pernicious anemia and/or PCA was found in 25 of 40 families of IDD probands with PCA.

Achlorhydria was demonstrated in 6 of 11 patients (54%) with PCA but in none of seven IDD patients without PCA. The six patients with achlorhydria had significantly lower uptakes of oral radiolabeled co-balamin, lower serum cobalamin levels, lower intrinsic factor-R protein ratios in their gastric aspirates, and lower plasma ferritin levels than patients with IDD but without PCA. None of the study group had IF antibodies in their serum or gastric juice. Overt pernicious anemia and neuropathy were found in one patient with PCA.

Young patients with IDD at risk for atrophie gastritis and cobalamin deficiency can initially be identified by screening for PCA. Many of these young patients with PCA already have achlorhydria and evidence of decreased absorption of cobalamin. These patients can then be followed with cobalamin levels and/or with complete blood counts to identify those requiring therapy.
Binding, Internalization, and Degradation of Insulin in Vascular Endothelial Cells
Authors: Kaiser N , Vlodavsky I , Tur-Sinai A , Fuks Z , Cerasi E
Published: September 2013

The interaction of insulin with the vascular endothelium was studied using bovine aortic endothelial cells in monolayer cultures. Confluent cell cultures exhibited specific binding of 125l-insulin to high- and low-affinity celt surface receptor sites. Binding was reversible, saturable, and accompanied by internalization and degradation of the bound hormone in a temperature- and time-dependent manner. Pre-exposure of the cultures to insulin resulted in a time-dependent reduction in the availability of cell surface receptors (downregulation).

It is concluded that the occurrence of reversible insulin binding and of insulin degradation in endothelial cells supports the concept that the vascular endothelium compartment may regulate the level of insulin in the Circulation.
Association of Elevated Fasting C-Peptide Level and Increased Intra-Abdominal Fat Distribution With Development of NIDDM in Japanese-American Men
Authors: Bergstrom Richard W , Newell-Morris Laura L , Leonetti Donna L , Shuman William P , Wahl Patricia W , Fujimoto Wilfred Y
Published: September 2013

The Japanese-American population of King County, Washington, is known to have a high prevalence of non-insulin-dependent diabetes mellitus (NIDDM). As part of a community-based study, we reexamined 146 second-generation Japanese-American men who had been initially classified as nondiabetic. At a mean follow-up period of 30 mo, 15 men had developed NIDDM, and 131 remained nondiabetic. The variables measured at the initial visit that distinguished the 15 diabetic men from the 131 nondiabetic men were older age, higher serum glucose level at 2 h after 75 g oral glucose, higher fasting plasma C-peptide level, and increased cross-sectional intra-abdominal fat area as determined by computed tomography. Both older age and higher 2-h glucose levels are variables that have been associated with the development of NIDDM, but the association of higher fasting C-peptide level and greater intra-abdominal fat area with subsequent development of NIDDM were new observations. The elevated fasting C-peptide level persisted after adjustment for fasting serum glucose. The elevated C-peptide level represents hypersecretion of insulin and was interpreted to reflect a compensatory response to an underlying insulin-resistant state that antedates the development of NIDDM. The fasting C-peptide level was correlated with the intra-abdominal fat area, suggesting that the intra-abdominal fat area may be associated with insulin resistance. Thus, in individuals who develop NIDDM, insulin resistance, increased insulin secretion, and increased intra-abdominal fat are present before diabetic glucose tolerance can be demonstrated.
Effect of Cyclosporin on Generalized Shwartzman Reaction in Diabetic Rats
Authors: Bunchman Timothy E , Michael Mauer S , Kim Youngki
Published: September 2013

The effect of cyclosporin (CsA) on the endotoxin-induced generalized Shwartzman reaction (GSR) was studied in diabetic and nondiabetic rats. After 4.5 wk of diabetes, CsA (20 mg/kg) or intralipid as a control substance was given intraperitoneally daily for 10 days. Next, diabetic rats were given either high-dose (2 mg/kg) or low-dose (0.1 mg/kg) endotoxin (Escherichia coli 026 :B6 lipopolysaccharide B) as a single injection. The rats were killed at intervals of 1, 4, 8, and 24 h. No significant glomerular thrombi were seen in the nondiabetic control animals, whereas the severity of glomerular thrombi in the diabetic animals was dependent on the presence or absence of CsA, endotoxin dose, and degree of glycemic control. In the diabetic rats, glomerular thrombi occurred maximally at 4 h but were no longer present at 24 h. The CsA/high-dose–endotoxin rats had fewer glomerular thrombi than rats receiving the intralipid/high–dose endotoxin, but this difference was not statistically significant. The CsA/low-dose–endotoxin rats had increased glomerular thrombi compared with the intralipid/low-dose–endotoxin rats (P < 0.01). Insulin treatment reduced the glomerular capillary thrombi in the CsA/low-dose–endotoxin diabetic animals. Thus, CsA aggravates the GSR with low-dose endotoxin but has no significant effect when high-dose endotoxin is given. Improved glycemic control reduces the GSR in CsA-treated rats. Thus, the interrelationships of diabetes, endotoxin, and CsA on the GSR are complex, and the pathogenesis of these events is unclear.
In Situ Characterization of Islets in Diabetes With a Mitochondrial DNA Mutation at Nucleotide Position 3243
Authors: Kobayashi Tetsuro , Nakanishi Koji , Nakase Hirofumi , Kajio Hiroshi , Okubo Minoru , Murase Toshio , Kosáka Kinori
Published: September 2013

Changes in the pancreas of diabetic patients with the A-to-G mitochondrial DNA (mtDNA) mutation at nucleotide position 3243 base pair (bp) have not previously been described. The clinical phenotypes of diabetes associated with the mtDNA 3243 mutation range from NIDDM to IDDM. We sought the presence of the mutation and studied volume of β-, α-, and δ-cells, mitochondrial enzyme activity, and presence of apoptosis in diabetic pancreases obtained at autopsy. Pancreases were obtained from 16 patients with IDDM, from 18 patients with NIDDM, and from 11 nondiabetic patients. Mitochondrial enzyme activity was determined for cytochrome c oxidase (COX), the subunits of which are partially encoded by mtDNA, and for succinate dehy-drogenase (SDH), the subunits of which are solely encoded by nuclear DNA. The volumes of islet β-, α-, and δ-cells were estimated by computerized morphometry. Pancreatic cells were examined for apoptosis by an in situ end-labeling procedure. The mtDNA 3243 mutation was detected in 1 of 16 (6%) pancreases from the IDDM patients; none of the pancreases from 18 NIDDM patients and 11 nondiabetic patients had the mutation. The single patient with the mtDNA 3243 mutation was a 56-year-old woman with IDDM, aged 39 years at diabetes onset, whose mother was diagnosed with NIDDM. The patient had a history of secondary failure of oral hypoglycemie agents and had a marked decrease in the number of β-cells. The islet β-cells and non-β-cells of the patient showed extremely decreased COX enzyme activity. The islet cells in the patient showed a high activity when examined for SDH. Some pancreatic exocrine cells also showed decreased COX activity with high SDH activity. In IDDM, NIDDM, and nondiabetic patients without the mtDNA 3243 mutation, only weak staining for SDH of the islet cells showed. The percentage of heteroplasmy of the mtDNA 3243 mutation in pancreatic micropunched islet specimens was 63 ± 5% (mean ± SD) in the islets, 32 ± 3% in the exocrine pancreas, and 8 ± 1% in peripheral polymorphonuclear cells. Apoptotic cells were not observed in the IDDM pancreas in the patient with the mtDNA 3243 mutation. The fact that higher levels of mutated mtDNA at 3243 bp were found in affected islets rather than in other tissue suggests that the distribution of the mutant may determine the effect on islet function. A characteristic decrease in the mitochondrial enzyme with COX activity and accelerated SDH activity of the affected islets may provide new insights into the pathogenesis of mitochondrial diabetes.
Seven Days of Euglycemic Hyperinsulinemia Induces Insulin Resistance for Glucose Metabolism but Not Hypertension, Elevated Catecholamine Levels, or Increased Sodium Retention in Conscious Normal Rats
Authors: Koopmans Sietse J , Ohman Lynne , Haywood Joseph R , Mandarino Lawrence J , DeFronzo Ralph A
Published: September 2013

Epidemiological studies have suggested an association among chronic hyperinsulinemia, insulin resistance, and hypertension. However, the causality of this relationship remains uncertain. In this study, chronically catheterized conscious rats were made hyperinsulinemic for 7 days (∼90 mU/1, i.e., threefold over basal), while strict euglycemia was maintained (∼130 mg/dl, coefficient of variation <10%) by using a modification of the insulin/glucose clamp technique. Control rats received vehicle infusion. Baseline mean arterial pressure and heart rate were 125 ± 5 mmHg and 427 ± 12 beats/min and remained unchanged during the 7-day infusion of insulin (127 ± 7 mmHg; 401 ± 12 beats/min) or vehicle (133 ± 4 mmHg; 411 ± 10 beats/min). Baseline plasma epinephrine (88 ± 15 pg/ml), norepinephrine (205 ± 31 pg/ml), and sodium balance (0.34 ± 0.09 mmol) remained constant during the 7-day insulin or vehicle infusion. After 7 days of insulin or vehicle infusion, in vivo insulin action was determined in all rats using a 2-h hyperinsulinemic (1 mU/min) euglycemic clamp with [3-3H]glucose infusion to quantitate whole-body glucose uptake, glycolysis, glucose storage (total glucose uptake minus glycolysis), and hepatic glucose production. Compared with vehicle-treated rats, 7 days of sustained hyperinsulinemia resulted in a reduction (P < 0.01) in insulin-mediated glucose uptake, glucose storage, and glycolysis by 39, 62, and 26%, respectively. Hepatic glucose production was normally suppressed after 7 days of hyperinsulinemia. Neither insulin-stimulated glucose uptake nor glucose storage correlated with blood pressure or heart rate. In conclusion, 7 days of euglycemic hyperinsulinemia induces severe insulin resistance with respect to whole-body glucose metabolism but does not increase blood pressure, catecholamine levels, or sodium retention. This indicates that hyperinsulinemia-induced insulin resistance is not associated with the development of hypertension in rats who do not have a genetic predisposition for hypertension. Because hyperinsulinemia was initiated in normal rats under euglycemic conditions, additional (inherited or acquired) factors may be necessary to observe an effect of hyperinsulinemia and/or insulin resistance to increase blood pressure.
Subcutaneous Abdominal Fat and Thigh Muscle Composition Predict Insulin Sensitivity Independently of Visceral Fat
Authors: Goodpaster Bret H , Leland Thaete F , Simoneau Jean-Aimé , Kelley David E
Published: September 2013

Whether visceral adipose tissue has a uniquely powerful association with insulin resistance or whether subcutaneous abdominal fat shares this link has generated controversy in the area of body composition and insulin sensitivity. An additional issue is the potential role of fat deposition within skeletal muscle and the relationship with insulin resistance. To address these matters, the current study was undertaken to measure body composition, aerobic fitness, and insulin sensitivity within a cohort of sedentary healthy men (n = 26) and women (n = 28). The subjects, who ranged from lean to obese (BMI 19.6-41.0 kg/m2), underwent dual energy X-ray absorptiometry (DEXA) to measure fat-free mass (FFM) and fat mass (FM), computed tomography to measure cross-sectional abdominal subcutaneous and visceral adipose tissue, and computed tomography (CT) of mid-thigh to measure muscle cross-sectional area, muscle attenuation, and subcutaneous fat. Insulin sensitivity was measured using the glucose clamp technique (40 mU · m∼2 · min−1), in conjunction with [3-3H]glucose isotope dilution. Maximal aerobic power (Vo2max) was determined using an incremental cycling test. Insulin-stimulated glucose disposal (Rd) ranged from 3.03 to 16.83 mg · min−1· kg−1 FFM. Rd was negatively correlated with FM (r = -0.58), visceral fat (r = -0.52), subcutaneous abdominal fat (r = -0.61), and thigh fat (r = -0.38) and positively correlated with muscle attenuation (r = 0.48) and Vo2max (r = 0.26, P < 0.05). In addition to manifesting the strongest simple correlation with insulin sensitivity, in stepwise multiple regression, subcutaneous abdominal fat retained significance after adjusting for visceral fat, while the converse was not found. Muscle attenuation contributed independent significance to multiple regression models of body composition and insulin sensitivity, and in analysis of obese subjects, muscle attenuation was the strongest single correlate of insulin resistance. In summary, as a component of central adiposity, subcutaneous abdominal fat has as strong an association with insulin resistance as visceral fat, and altered muscle composition, suggestive of increased fat content, is an important independent marker of insulin resistance in obesity.
Multimodal evaluation of the effectiveness of a hand hygiene educational campaign at a small animal veterinary teaching hospital
Authors: Smith Jo R. , Packman Zoe R. , Hofmeister Erik H.
Published: September 2013

Objective—To determine the effect of an intervention (educational campaign) on hand hygiene (HH) and health-care workers' (HCWs') perceptions of HH.

Design—Prospective observational study and cross-sectional survey.

Sample—Observed opportunities for HH performed by HCWs before (n = 222) and after (249) intervention, measures of HH product usage, and surveys distributed to 300 HCWs.

Procedures—Data were collected by means of direct observation, measurement of HH product consumption, and surveys of HCWs.

Results—Adherence rates of HCWs for HH practices before and after the intervention were 27% (61/222 observations) and 29% (73/249 observations), respectively. Combined HH and glove use adherence rates before and after the intervention were 84% (186/222 observations) and 81% (201/249 observations), respectively. Before intervention, the highest combined HH and glove use adherence rate was detected for technicians (90% [57/63 observations]) and for opportunities after exposure to a patient's bodily fluids (100% [5/5 opportunities]). Rate of use of alcohol-based antimicrobial hand rubs (AHRs) and amount of HH products used did not significantly change during the study. Survey response rates were 41% (122) and 21% (62) before and after the intervention, respectively. Availability of AHRs and role modeling of HH (performance of HH each time it is warranted) were considered the factors most likely to increase HH adherence rates by survey respondents.

Conclusions and Clinical Relevance—Results indicated the intervention did not increase HH adherence or use of AHRs. High rates of glove use before the start of the study may have been a confounding factor. Future educational campaigns should indicate that glove use should not supersede HH.
Evaluation of Aerial Spray Technologies for Adult Mosquito Control Applications
Authors: Hoffmann Wesley Clint , Fritz Bradley Keith , Farooq Muhammad , Walker Todd William , Czaczyk Zbigniew , Hornsby Jonathan , Bonds Jane Annalise Sara
Published: September 2013

Spray droplet size has long been recognized as an important variable that applicators of vector control sprays must be aware of to make the most effective spray applications. Researchers and applicators have several different techniques available to assess spray droplet size from spray nozzles. The objective of this study was to compare the droplet size spectrum produced by three nozzles commonly used in vector control in a high-speed wind tunnel, when characterized using three different laser-based droplet size measurement systems.

Three droplet sizing systems: Malvern Spraytec laser diffraction, Sympatec HELOS laser diffraction, and TSI Phase Doppler Particle Analyzer (PDPA), were simultaneously operated, but under different operating conditions, to measure the spray droplet size-spectra for three spray nozzles. The three atomizers: a TeeJet® 8001E even flat fan nozzle, a BETE® PJ high pressure fog nozzles, and a Micronair ® AU5000 rotary atomizer were evaluated in a high speed wind tunnel at airspeeds of 53 and 62 m/s (120 and 140 mph). Based on the results of this work, only the BETE® PJ high pressure fog nozzles met the label requirements for both Fyfanon® and Anvil®. While the other nozzle might met the Dv0.5 (VMD - volume median diameter) requirement for Fyfanon®, the resulting Dv0.9 values exceeded labeled size restrictions. When applying Anvil with the BETE PJ high pressure fog nozzles, it is important to use the smaller two orifice sizes. The larger sizes tended to result in Dv0.9 values that exceeded label recommendations
Risk Factors For Drug Induced Hepatitis Under Dots Programme In General Population
Authors: Gaude Gajanan S , Hattiholi J , Reyas AK
Published: September 2013

Background: Short course chemotherapy containing rifampicin and isoniazid in combination has proved to be highly effective under DOTS regimens in the treatment of tuberculosis, but one of its adverse effects is hepatotoxicity. Little however has been published regarding drug induced hepatitis (DH) under general programme conditions. In this study, we aimed to determine the prevalence of drug induced hepatitis and the risk factors associated with the development of hepatitis over a period of 5 years. Methodology: This was a prospective study done from 2007 to 2011 in a tertiary care hospital. A total of 116 patients were included in the study that presented with hepatitis due to short course chemotherapy and were being treated under various categories of drug regimens. Fourty cases were being followed up and other 76 were seen at the hospital for the first time after the development of hepatitis. The diagnostic criteria’s for drug-induced hepatitis were made according to the ATS criteria’s. Various risk factors were analyzed for the development of DH. Results: The prevalence of DH in the present study was 3.6%. It was observed that DH patients were older and their serum albumin levels were lower. Regular alcohol intake, more extensive disease radiologically and female gender were observed to be independent risk factors for the development of DH. No other risk factors analyzed had any signifi cant association with DH. Conclusion: Of the various risk factors analyzed, advanced age, hypoalbuminaemia, regular alcohol intake and advanced nature of the disease were independent risk factors for the development of DH. The risk of hepatitis in the presence of one or more of these risk factors may be increased. SAARC Journal of Tuberculosis, Lung Diseases & HIV/AIDS; 2013; X(1); 19-26 DOI: http://dx.doi.org/10.3126/saarctb.v10i1.8673