bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Incidence of Congenital Malformations in the Offspring of Diabetic Rats and Their Prevention by Maternal Insulin Therapy
Authors: Eriksson Ulf , Dahlström Elisabeth , Larsson K Sune , Hellerström Claes
Published: September 2013

Intensive care of the pregnant mother with diabetes has dramatically decreased the incidence of diabetic fetopathy. The persistently high rate of fetal and neonatal mortality in diabetic pregnancies is nowadays mainly due to the increased incidence of serious congenital malformations. However, attempts to elucidate the precise teratogenic mechanisms have been sparse, presumably because of a lack of relevant animal models. In the present study we recorded the incidence and types of skeletal malformations in live offspring of normal rats and in rats made diabetic with the B-cytotoxic agent streptozotocin (SZ) at least 2 wk before conception. In some of the diabetic animals insulin treatment was begun 1 wk after the SZ injection and continued throughout pregnancy. In addition, the fetal development was followed by assessing the calcification of the skeleton on gestational days 20 and 22 with the aid of Alazarin Red S staining.

Manifest diabetes in the pregnant rat induced a decrease in fetal weight and viability and marked retardation of skeletal maturation. In addition, about 20% of 135 viable fetuses showed skeletal malformations comprising either micrognathia or caudal dysgenesis. These defects were not found in 314 offspring of the control rats. Only two cases of caudal dysgenesis and none of micrognathia were detected among 233 offspring of the insulin-treated rats.

The present data underscore the importance of a strict differentiation in the offspring of the diabetic rat between transient development retardations and true malformations. They also demonstrate that correction of the maternal glucose intolerance is crucial for preventing the fetus from developing skeletal malformations. Altogether the data suggest that fetal malformations in the diabetic rat are attributable either to the hyperglycemia as such or to some accompanying metabolic consequence of insulin deficiency.
Bactericidal Properties of Commercial U.S.P. Formulated Insulin
Authors: Schade David S , Eaton R Philip
Published: September 2013

This study examined the suitability of commercial U.S.P. insulin as a bacterial growth medium. Purified port insulin (Iletin II, Eli Lilly & Co., Indianapolis, Indiana) was inoculated with approximately 500,000 bacteria per ml of: (1) Staphylococcus epidermidis, (2) Staphylococcus aureus, or (3) Escherichia coli. All three bacterial cultures were sterilized by the insulin within 24 h at 37°C. However, Staph epidermidis was the most sensitive and Escherichia coli was least sensitive to the bactericidal effects of commercial U.S.P. insulin. Components of commercial U.S.P. insulin were then examined for their bactericidal activity against Escherichia coli. Phenol (230 mg/dl), glycerol (1.6 d/dl), and zinc cations (4.0, 2.0, and 1.0 mg/dl) demonstrated bactericidal activity, whereas dialyzed insulin demonstrated minimal effects. We conclude that insulin contaminated with 5 × 105 bacteria commonly found on the skin will self-sterilize within 24 h. This effect is secondary to the additives placed in the insulin and not to the insulin itself.
Nonhuman Primates as Models for the Study of Human Diabetes Mellitus
Authors: Howard Charles F
Published: September 2013

Nonhuman primates have been used for a variety of studies on diabetes meiiitus. Spontaneous, natural forms of diabetes have been well documented in several species; there are limited data on numerous other species that indicate diabetes or a diabetes-like syndrome. The causes and manifestations of spontaneous diabetes, their prevalence, and their severity vary among species. Diabetes has also been induced in nonhuman primates with streptozotocin, alloxan, hypothalamic lesions, or pancreatectomy. The extent and severity of metabolic and hormonal abnormalities vary according to the method of induction, the individual monkey, and the species.

Metabolic, hormonal, and pathologic abnormalities present in human diabetics also occur in monkeys with either spontaneous or induced diabetes. Hyperglcemia, and impaired glucose clearance are common, lipid concentrations are elevated, and hemoglobin A1c concentrations are increased in Hyperglycemic monkeys. Monkeys may have fasting hypo- or hyperinsulinemia; insulin responses are often impaired in glucose tolerance tests. Glucagon concentrations may be increased. Aortic atherosclerosis, muscle capillary microangiopathies, cataracts, and glomeruio-sclerosis have been documented.

Primate size and longevity allow longitudinal studies with procedures that may not be feasible in smaller animals or in human beings. Nonhuman primates may be the models of choice for studies on selected aspects of diabetes and its secondary complications.
Pancreatic Content of Insulins I and II in Laboratory Rodents: Analysis by Immunoelectrophoresis
Authors: Kakita Keiji , O'connell Keith , Permutt M Alan
Published: September 2013

The purpose of these experiments was to determine the relative proportion of insulins I and II in the pancreas of inbred strains of mice and rats, and whether this proportion would be altered by conditions known to affect insulin biosynthesis. Rapid analysis of multiple samples was accomplished by an immunoelectrophoretic method in which insulin can be detected in crude pancreatic extracts without further purification. Insulin I was found to account for 65–76% of total pancreatic content in C3H/HeJ, C57BL/6J, and CD2F1 mice. Glucose injection produced a significant increase in insulin content, which was completely accounted for by insulin I, although fasting for 2 days had no effect. In all three strains there was either no change or a decrease in content of insulin II, while insulin I increased 77–83% (P < 0.05) of the total pancreatic insulin.

To determine the effects of chronic hyperglycemia, the content of insulins I and II was measured in the pancreas of obese hyperglycemic mice and compared with that of lean littermates. Insulin content in pregnant rats was also evaluated, since pregnancy is characterized by insulin resistance and hyperinsulinemia. The results of these studies indicate that insulin I predominates in the pancreas of a variety of strains of rats and mice. More important is the observation that conditions that increase insulin production preferentially increase insulin I relative to II, suggesting independent regulation of the two genes.
Normal Responses of Rats with Transplanted Neonatal Islets to Stress, Epinephrine, and Cortisol
Authors: Woo Rosy , Pi-Sunyer F Xavier
Published: September 2013

Sympathetic responses were evaluated in rats transplanted with neonatal pancreatic tissue. Transplantation was by one of two methods: mild collagenase digestion with subsequent intraportal injection, or direct placement of intact pancreatic tissue under the renal capsule. Compared with control intact animals, both groups of transplanted rats reverted to normal fasting and postglucose load plasma glucose and insulin. The hyperglycemia characteristic of stress or of injected exogenous epinephrine was present and similar in all three groups. The response to an intragastric glucose load or to tolbutamide injection during stress was similar in transplanted and in control animals. All three groups of rats responded to sustained cortisol injection with a compensatory hyperinsulinemia but maintained normal plasma glucose, water intake, and urine volume. No evidence could be detected in this study of an exaggerated “denervated” response of the transplanted islets. The normal sympathetic responses of these neonatal islet preparations in which little or no collagenase was used, in comparison with the abnormal responses previously reported for collagenase-treated individually isolated adult rat islets, suggest differences in recuperative powers of the sympathetic innervation in islets, possibly related to age and to method of preparation of transplanted tissue.
HLA-DR Specifications in Japanese with Juvenile-onset Insulin-Dependent Diabetes Mellitus
Authors: Sakurami Takehiko , Ueno Yukio , Nagaoka Kengo , Kuno Shotaro , Iwaki Yuichi , Park Min S , Terasaki Paul I
Published: September 2013

Specific allelic associations vary among ethnic groups. We studied the distribution of HLA-A,-B,-C, and -DR antigens in 34 Japanese juvenile-onset diabetic patients. The focus of our current work was HLS-DR antigens because there have been few studies of Japanese with this disease. A significant increase in the frequency of HLA-DR4 was found in patients but not in unaffected persons: DR4 was found in 56.3% of the patients versus 32.6% of the unaffected persons. However, the negative correlation between DR2 and patients was not statistically significant.
Tolbutamide Stimulates Gastric Somatostatin Release from Isolated Perfused Rat Stomach
Authors: Chiba Tsutomu , Taminato Tomohiko , Kadowaki Seizo , Chihara Kazuo , Matsukura Shigeru , Seino Yutaka , Fujita Takuo
Published: September 2013

The effect of tolbutamide on somatostatin release from the isolated perfused stomach was investigated in both normal and streptozotocin-diabetic rats. Tolbutamide (10, 100, and 1000 μg/ml) evoked a significant and dose-dependent increase in gastric somatostatin release. The tolbutamide (100 μg/ml)-induced gastric somatostatin secretion was not influenced by differences in glucose concentration (1.5, 5.5, and 16.5 mM) throughout the perfusion period. Tolbutamide (100 microgram/ml)-induced gastric somatostatin release in streptozotocin-diabetic rats was significantly higher than in normal rats. Thus, tolbutamide is a potent secretagogue for gastric somatostatin secretion, and this effect is more prominent in diabetic animals.
Superfusion of Dissociated Pancreatic Islet Cells Attached to Cytodex Beads
Authors: Spiess Yuriko , Smith Mark A , Vale Wylie
Published: September 2013

Pancreatic islets of neonatal were dissociated by collagenase and cultured for 3 days in the presence of Cytodex beads to allow attachment of the cells to these microcarriers. The bead-attached cells were packed in columns and superfused with a low bicarbonate medium using the same method that we had originally developed for dissociated anterior pituitary cells of the rat. The secretion of insulin, somatostatin, and glucagon by the cells was monitored by radioimmunoassays.

The cells in the superfusion system responded as expected from experiments with islet and monolayer cultures of rat pancreas in vitro and in vivo. Increasing glucose concentrations in the superfusion medium increased the release of insulin and somatostatin (SS), whereas glucagon secretory rates remained constant or decreased. A dose-response curve was established between insulin release and D-glucose in which the ED50 of D-glucose for insulin was found between 1.5 and 2 mg/ml. The phosphodiesterase inhibitor, 3-isobutyl-methylxanthine (IBMX), significantly potentiated the insulin response to glucose. Various secretagogues such as IBMX, 8-bromo cyclic AMP, and L-arginine increased insulin, somatostatin, and glucagon secretory rates in an expected manner.

The superfusion method offers the possibility to investigate the interactions of dissociated A-, B-, and D-cells and the dynamics of hormone release in short- and long-term in vitro experiments. The method is simple and avoids the problems of monolayer procedures, such as clustering of the cells and poor adherence of dissociated pancreatic islet cells to dishes.
Integrated Regulation of Very Low Density Lipoprotein Triglyceride and Apolipoprotein-B Kinetics in Non-insulin-dependent Diabetes Mellitus
Authors: Kissebah Ahmed H , Alfarsi Salman , Evans David J , Adams Peter W
Published: September 2013

Turnover rates of plasma very low density lipoprotein (VLDL) triglyceride (TG) and apolipoprotein-B (apo-B) were significantly increased in age- and weight-matched groups of normolipemic and hyperlipemic mild diabetics, and hyperlipemic moderately severe diabetics when compared with normolipemic controls. As in the normolipemic subjects, a significant correlation between VLDL TG and apo-B turnover rates was found in all diabetic groups, suggesting that integration of TG and apo-B production at synthetic and/or secretory sites is retained in diabetes, thus resulting in increased secretion of VLDL particles of normal composition. In normolipemic mild diabetic subjects, the fractional turnover rates of VLDL TG and apo-B were also significantly increased so that increased removal accompanied increased VLDL production. In the hyperlipemic diabetics, however, the fractional turnover rates were significantly reduced, hence the increased in VLDL removal was not sufficient to compensate for enhanced production. In normolipemic mild diabetic patients, low density lipoprotein (LDL) formation was increased, only a small fraction of VLDL apo-B being removed via a non-LDL pathway, presumably as remnant VLDL. In hyperlipemic mild diabetics, removal of VLDL apo-B via both the LDL and non-LDL pathways was increased. In hyperlipemic moderately severe diabetes, LDL formation was not increased; catabolism of VLDL apo-B through the non-LDL route was however, fivefold > normal. We conclude that increased VLDL secretion is a fundamental defect in non-insulin-dependent diabetes. In hyperlipemic individuals, VLDL removal is also impaired. The increase in LDL and/or VLDL remnant formation, regardless of prevailing plasma lipid levels or the severity of diabetes, provides a source of cholesterol which may account for the atherogeneity of this disorder.
Preservation of Morphology, Insulin Biosynthesis, and Insulin Release in Cryopreserved Human Fetal Pancreas
Authors: Sandler S , Andersson A , Hellerström C , Petersson B , Swenne I , Björkén C , Groth C -G
Published: September 2013

Human fetal pancreatic glands were obtained from 12 consecutive prostaglandin-induced abortions. Explants cultured for 1 day were frozen at 0.3°C/min in a 1 M DMSO-containing medium and stored at −196°C. After storage for 3–4 mo the frozen material was rapidly thawed and cultured 1 day before being tested for functional performance. There was a positive correlation between the pancreatic insulin content and the fetal crown-heel length. Seven of the twelve fetuses showed a marked insulin response to an acute glucose-theophylline challenge. In five of these pancreases there was a well-preserved morphology after thawing, whereas only one of the nonresponding preparations showed a satisfactory morphology. Pancreatic explants from three of four fetuses tested displayed evidences of an (pro)insulin biosynthesis. The combined results indicated that low-temperature storage of human fetal endocrine pancreas is compatible with specific functional survival.
The Effect of Chronic α-Glycosidase Inhibition on Diabetic Nephropathy in the db/db Mouse
Authors: Lee Stanley M
Published: September 2013

Acarbose, a complex oligosaccharide, is a potent competitive inhibitor of sucrase and decreases postprandial hyperglycemia when administered with food. To evaluate its potential for metabolic control and prevention of diabetic nephropathy, groups of gentically diabetic mice (C57 BLKsJ db/db) were treated with Acarbose for 10 wk. Control mice received normal chow and experimental groups were given Acarbose prepared as a drug-food mixture in doses of 10, 20, and 40 mg/100 g of food. Acarbose did not influence fasting blood glucose, food intake, or the normal development of obesity in the mice. Urinary glucose excretion and glycosylated hemoglobin was significantly reduced in animals receiving high-dose Acarbose (40 mg/100 g food). Immunopathologic examination of the kidneys showed a dose-dependent decrease in glomerular mesangial immunoglobulin deposition. By light microscopy, glomerular mesangial thickening was significantly reduced in the group receiving high-dose Acarbose (40 mg/100 g food). To the extent that Acarbose improves metabolic control in the db/db mouse, chronic treatment with this agent produces a dose-dependent amelioration of diabetic nephropathy. Alphaglycosidase inhibition may be a useful adjunctive therapy for blood glucose control in diabetes mellitus.
Restriction Fragment Length Polymorphism of the Insulin Gene in Diabetes Mellitus
Authors: Owerbach David , Nerup Jørn
Published: September 2013

Variant DNA sequences flanking the human insulin gene were found in the Danish population using restriction endonucleases (restriction fragment length polymorphism). The frequencies of these DNA sequences were determined in 47 non-insulin-dependent diabetics and 93 control individuals. We report an association between a restriction fragment length polymorphism of the insulin gene and NIDDM.
Islet Cell Surface Antibodies and Lymphocyte Antibodies in the Spontaneously Diabetic BB Wistar Rat
Authors: Dyrberg Thomas , Nakhooda Azima F , Baekkeskov Steinunn , Lernmark Åke , Poussier Philippe , Marliss Errol B
Published: September 2013

Plasma from 14 diabetic and 6 nondiabetic BB Wistar rats along with plasma from 6 non-BB Wistar rats was evaluated for the presence of islet cells surface antibodies (ICSA) and antibodies to spleen lymphocytes by the protein-A radioligand assay. Dispersed Wistar rat islet cells incubated with plasma from diabetic rats bound 4255 ± 2208 cpm 125I-protein A/5 × 104 islet cells (mean ± SD) compared with 984 ± 454 cpm/5 × 104 islet cells in islet cells incubated with plasma from nondiabetic BB rats (P < 0.005). Twelve of the 14 diabetic rats with a duration of diabetes for 3–11 days bound radioactivity above the mean and 2 × SD of controls. The binding of 125I-protein A did not differ between nondiabetic BB rats and non-BB Wistar rats. Wistar rat spleen lymphocytes incubated in diabetic plasma bound 20,249 ± 10,783 cpm/2 × 106 spleen lymphocytes compared with 3460 ± 1809 in the controls (P < 0.005). Animals positive for ICSA correlated with those positive for spleen lymphocyte antibodies. It is concluded that ICSA and splenic lymphocyte antibodies are present in diabetic BB rats.
Nonenzymatic Glycosylation and Browning in Diabetes and Aging: Studies on Lens Proteins
Authors: Monnier Vincent M , Cerami Anthony
Published: September 2013

The nonenzymatic glycosylation of hemoglobin has served as a model for the postsynthetic modification of protein by glucose. From these studies it has been proposed that nonenzymatic glycosylation of proteins could play a role in the development of the complications associated with diabetes mellitus. The first tissue in which an attempt has been made to link nonenzymatic glycosylation and a pathologic sequela is the ocular lens and the formation of cataracts. Incubation of lens proteins with glucose in vitro leads to nonenzymatic glycosylation, intermolecular disulfide bond formation, and protein aggregates that defract light. These findings mimic the state of proteins found in the diabetic lens. With longer incubation times, these nonenzymatically glycosylated proteins can undergo further rearrangements to form yellow-brown pigments (nonenzymatic browning) that act as molecular cross-links. From a number of physical and chemical studies it appears that these pigments formed in vitro are similar to those found in senile lenses.

Thus the nonenzymatic browning of glycosylated proteins that has been described in stored foodstuffs might well be occurring in vivo. Such protein modifications, which are essentially irreversible, could have significant effects on the aging of long-lived proteins and the general aging process of biologic systems.
Effect of Sulfonylurea Treatment on In Vivo Insulin Secretion and Action in Patients With Non-insulin-dependent Diabetes Mellitus
Authors: Greenfield Michael S , Doberne Leonard , Rosenthal Mark , Schulz Bernd , Widstrom Anders , Reaven Gerald M
Published: September 2013

The effect of glipizide treatment on diabetic control and on in vivo insulin secretion and action was studied in 20 patients with non-insulin-dependent diabetes mellitus (NIDDM). Patients were examined before and after a minimum of 3 mo treatment. Mean (± SEM) fasting plasma glucose level fell from 264 ± 12 mg/dl to 172 ± 10 mg/dl (P < 0.001) after glipizide treatment, and this was associated with a fall in total plasma glucose response to a test meal of approximately 35﹪. Mean (±SEM) fasting plasma insulin levels increased slightly from 15 ± 2 μU/ml to 18 ± 2 μU/ml following sulfonylurea treatment, and the total plasma insulin response to the test meal increased by 63﹪. However, there was no correlation (r = −0.20) between the increase in plasma insulin response and the fall in plasma glucose levels that occurred as the result of sulfonylurea therapy. Glipizide treatment also led to enhanced in vivo insulin action, whether measured by the insulin clamp technique (P < 0.001) or the insulin suppression test (P < 0.02). Furthermore, in this instance there was a significant correlation (r = 0.69, P < 0.001) between the enhanced insulin action and the improvement on diabetes control. Thus, chronic therapy with glipizide, a new sulfonylurea agent, led to increased in vivo insulin secretion and insulin action. These results lend direct support to the assumption that sulfonylurea compounds have a substantial extrapancreatic effect on glucose homeostasis, and suggest that this effect contributes to the therapeutic efficacy of these drugs.
Gastric Parietal Cell and Other Autoantibodies in the BB Rat
Authors: Elder Melissa , Maclaren Noel , Riley William , McConnell Thomas
Published: September 2013

A longitudinal study of circulating autoantibodies in the sera of 48 BB rats was performed by indirect immunofluorescence. No pancreatic islet cell, adrenocortical, or thyroid microsomal autoantibodies were found. However, autoantibodies reactive to gastric parietal cells (PCA), smooth muscle, and thyroid colloidal antigens were identified, PCA were not detected in Wistar-Furth or BB × Wistar-Furth F1 hybrid rats. The range of ages at the time of first appearance of PCA was the same as that of onset of insulin-dependent diabetes (IDD) in the BB rats, suggesting that the processes leading to PCA and IDD were occurring at the same time of life in these animals. The presence of PCA was associated with degrees of lymphocytic gastritis and with squamous metaplasia of the gastric mucosa in the oldest BB rats (9 mo of age). Levels of serum iron and vitamin B12 did not differ between PCA-positive and PCA-negative BB rats, nor was achiorhydria found in any rat studied.

The identification of PCA (and chronic gastritis) and other autoantibodies in the BB rat suggests that these animals have an underlying autoimmune diathesis.

These findings thus provide indirect support for an autoimmune pathogenesis for IDD in the BB rat.
Contribution of the Liver and Extrasplanchnic Tissues to the Hypoglycemic Action of Dichloroacetate in the Conscious Dog
Authors: Diamond Michael P , Suhrer James H , Williams Philip E , Lacy William W , Cherrington Alan D
Published: September 2013

In a previous study, administration of sodium dichloroacetate (DCA) to 48-h fasted dogs had no effect on glucose production (Ra), utilization (Rd), or clearance, possibly because the direct effects of DCA were offset by the consequences of the fall in plasma insulin that it caused. To examine this possibility, dichloroacetate was infused (0.4 mg/kg min) for 5 h into 48-h fasted conscious dogs whose insulin and glucagon levels were “clamped” at basal values using a technique that involved the peripheral infusion of somatostatin to inhibit the endocrine pancreas and intraportal replacement of insulin (273 μU/kg·min) and glucagon (1 ng/kg·min). Metabolite balances across the liver were measured using an A-V difference technique, glucose turnover was determined using a tracer technique, and gluconeogenesis was assessed by measuring the conversion of alanine and lactate into glucose.

In the presence of fixed concentrations of insulin (14 μU/ml) and glucagon (162 pg/ml), DCA caused the conversion of alanine and lactate to glucose to fall by 73 ± 10﹪ (P < 0.01), glucose production to fall by 19 ± 9﹪ (NS), glucose utilization to fall by 17 ± 8﹪ (NS), glucose clearance to increase by 55 ± 16﹪ (P < 0.05), and the plasma glucose level to fall from 107 ± 10 to 56 ± 6 mg/dl (P < 0.001) after 300 minutes. Thus, with the plasma insulin level fixed, DCA induced hypoglycemia through an effect on both glucose production and clearance. Since the effects of DCA in the above experiment were undoubtedly attenuated by the hypoglycemia that occurred, the experiment was repeated with the exception that glucose was infused to maintain euglycemia (113 ± 11 mg/dl). In this case, the conversion of alanine and lactate to glucose fell by 76 ± 1﹪ (P < 0.01), endogenous glucose production fell 46 ± 11﹪ (P < 0.01), glucose utilization rose 39 ± 14﹪ (P < 0.05) and glucose clearance increased 40 ± 18﹪ (P < 0.05). Normalization of the alanine and lactate levels during the last 90 min of the latter experiment failed to significantly change glucose production and enhanced gluconeogenic conversion only slightly. Thus, in the conscious 48-h-fasted dog, we conclude that: (1) DCA acts to reduce the insulin/glucagon molar ratio such that the production of hypoglycemia is prevented, (2) when the effect of the compound on the pancreas is prevented, DCA causes hypoglycemia by a reduction in hepatic glucose production and a stimulation of peripheral glucose uptake, and (3) the effect of DCA on glucose production is in part due to reduced gluconeogenic substrate supply, but is principally related to the action of DCA on intrahepatic enzymatic processes.
The Surface Concentration of H-2 Antigens on Mouse Pancreatic β-Cells and Islet Cell Transplantation
Authors: Parr Earl L , Oliver John R , King Nick J C
Published: September 2013

Measurement of the concentration of H-2 complex antigens in the surface membrane of mouse pancreatic β3-cetls by a quantitative immunoferritin-labeling technique revealed that the antigens were present in very small amounts on the β3-cells of five strains. Å comparison of the labeling densities in the five strains suggested that β3-cells from C57BL/10Sn congenic strains have about half the H-2 antigen density of BALB/c and C3H/HeJ cells, in C57BL/10Sn mice the antigen density on β3-cells was slightly greater than that on erythrocytes, about 20% of that on thymocytes, and about 2.5% of that present on peritoneal macrophages.

Intraperitoneal allografts of C57BL/10Sn islets were uniformly rejected by B10.BR/SgSn diabetic recipients only when the islets were accompanied by 107 peritoneal lymphoid cells. When transplanted without peritoneal cells, C57BL/10Sn islets were only marginally rejectable. In a group of nine such allografts, three diabetic recipients were permanently cured and three others showed rejection times of about 30 days. Sensitization of the three mice showing permanent cures, using 107 allogeneic peritoneal cells at about 40 days after the transplant, did not cause rejection of the allografts. isogeneic transplantation of cell suspensions from dissociated islets of Langerhans was markedly less effective in controlling diabetes than intact islets, and dissociation did not obviously improve the rate of allograft survival. However, 5/19 diabetic mice receiving allografts of dissociated islet cells showed longterm reversals of diabetes that were unaffected by administration of 107 peritoneal cells at about 100 days after the transplant. Recipient mice whose diabetes was reversed by islet allografts and unaffected by specific sensitization had pancreatic insulin concentrations characteristic of diabetic mice. Our reversals of diabetes with untreated islet allografts may be due to the cleanliness of islet preparations obtained with a modified isolation technique, and to the very low density of H-2 complex antigens on C57BL/10Sn β-cells.
Report of International Human Pancreas and Islet Transplantation Registry Cases Through 1981
Authors: Sutherland David E R
Published: September 2013

According to cases reported to the new international Human Pancreas and Islet Transplantation Registry, 190 pancreas transplants in 178 patients were performed worldwide between December 16, 1966, and December 31, 1981. Currently (March 1982), 19 patients have functioning pancreas grafts and are insulin-independent, 9 for more than 1 yr. All of the patients with currently functioning grafts were transplanted after 1977. Since 1970, 76 islet transplants have been attempted in 71 patients, of which almost all failed and no patients are currently insulin-independent. Although the technical problems with pancreas transplants are not entirely solved, the major cause of graft failure has been rejection. The need for antirejection therapy has limited the application of pancreas transplantation to diabetic renal eliografi recipients or to nonuremic patients whose complications of diabetes are, or predictably will be, worse than the side effects of chronic immunosup-pression. Pancreas transplantation can, however, be performed with expectation of long-term success in some patients with current surgical and immunosuppressive methods.
Tissue Culture Reduces la Antigen-bearing Cells in Rat Islets and Prolongs Islet Allograft Survival
Authors: Rabinovitch Alexander , Alejandro Rodolfo , Noel Jack , Brunschwig Jean-Pierre , Ryan Una S
Published: September 2013

Prolongation of rat pancreatic islet allograft survival by a prior 7-day period of tissue culture was demonstrated, confirming previous reports by others. We then sought to identify those cells in islets capable of stimulating allograft rejection (la antigen-bearing cells) and to determine whether such cells and/or their la antigens might be reduced by tissue culture. Freshly isolated and 7-day-cultured Wistar-Furth rat islets were incubated with a mouse anti-rat la nonpolymorphic monoclonal antibody, then with peroxidase-conjugated goat anti-mouse antibody, and processed for electron microscopy. Peroxidase (la)-positive lymphocytes, macrophages, and capillary endothelial cells were identified in fresh but not in cultured islets. A radioligand assay, using 125I-protein A, revealed a 45% decrease in binding of la antibody to cultured compared with fresh islet cells. We conclude that la antigen-bearing lymphocytes, macrophages, and capillary endothelial cells in rat islets are reduced by tissue culture and that this may account, at least in part, for the decreased immunogenicity of cultured islet allografts.
The Influence of Removing Passenger Cells on the Fate of Skin and Parathyroid Allografts: Evidence for Major Histocompatibility Complex Restriction in Transplantation Immunity
Authors: Silvers Willys K , Fleming Hilari L , Naji Ali , Barker Clyde F
Published: September 2013

Studies with mice on the survival of skin grafts incompatible with respect to the histocompatibiiity-Y transplantation antigen or to skin-specific antigens, as well as studies with rats on the fate of cultured parathyroid allografts, provide evidence for major histocompatibility restriction in transplantation immunity. If confirmed, these studies indicate that islet allografts devoid of passenger leukocytes might survive better in major histocompatibility complex incompatible recipients.
Estimation of the Secretion Rate of Insulin from the Urinary Excretion Rate of C-Peptide: Study in Obese and Diabetic Subjects
Authors: Meistas Mary T , Rendell Marc , Margolis Simeon , Kowarski A Avinoam
Published: September 2013

Direct methods for measuring the secretion rate of insulin are too cumbersome for clinical application. Since C-peptide is secreted in an equimolar ratio with insulin and is excreted into the urine, measuring the urinary excretion rate of C-peptide (U-C) could serve as an indicator of its secretion rate (SR-C) if its urinary clearance (UCI-C) is constant and unaffected by plasma C-peptide concentration, body mass, or diabetes.

We measured clearance ratios of C-peptide/creatinine (CR) in the fasting state and integrated 0–1, 1–3, and 3–5 h after 100 g of glucose p.o. as well as over a full 24-h in eight obese, eight lean, and six maturity-onset diabetic subjects. CR did not differ significantly when values in the fasting state were compared with those in the postprandial periods and was therefore unaffected by plasma C-peptide concentration. Furthermore, CR was similar in the lean, obese, and diabetic subjects. SR-C, determined as the product of the metabolic clearance rate of C-peptide and its fasting or integrated plasma concentrations, correlated significantly with U-C in all the subjects (r = 0.87, P < 0.0001). The correlation of U-C with SR-C in the diabetic subjects alone was also significant (r = 0.88, P < 0.0001). In conclusion, our data support the use of U-C as an indirect measure of SR-C and therefore of SR-I.
Preferential Lysis of Pancreatic B-Cells by Islet Cell Surface Antibodies
Authors: Dobersen Michael J , Scharff Joshua E
Published: September 2013

Sera from patients with insulin-dependent diabetes mellitus (IDDM) containing islet cell surface antibodies (ICSA) were studied for their capacity to lyse cultured rat islet cells. The uptake of ethidium bromide was used to identify lysed cells and immunofluorescent staining with antisera to insulin, glucagon, somatostatin, or pancreatic polypeptide was used to identify the different islet cell types (B-, A-, D-, and PP-cells, respectively). Our experiments showed that in the presence of complement, sera containing ICSA lysed 81% of the B-cells, but 10% or less of the A-, D-, and PP-cells. Normal control sera resulted in lysis of less than 4% of each of the islet cell types. The demonstration that ICSA are preferentially lytic for B-cells may be important in defining the role of these autoantibodies in the pathogenesis of IDDM, particularly since the B-cell mass in diabetics is markedly reduced relative to the other islet cell types.
Regulation of Serum Potassium During Insulin-induced Hypoglycemia
Authors: Petersen Karl-Georg , Schlüter Klaus Joachim , Kerp Lothar
Published: September 2013

Counterregulatory secretion of epinephrine occurs during severe insulin-induced hypoglycemia. Under these conditions (minimal plasma glucose 27.4 ± 1 mg/dl) the decrease of serum potassium concentration (0.9 mVal/L) is mediated by two mechanisms: insulin-induced (0.48 mVal/L) and epinephrine-induced (0.42 mVal/L) cellular uptake of potassium. Epinephrine-induced serum potassium uptake appears to be more sensitive to beta-adrenoceptor blockade than glucose production. The intensification of insulin-induced hypokalemia by epinephrine is of clinical significance.
Quantitation of Endocrine Cell Content in the Pancreas of Nondiabetic and Diabetic Humans
Authors: Stefan Yolande , Orci Lelio , Malaisse-Lagae Francine , Perrelet Alain , Patel Yogesh , Unger Roger H
Published: September 2013

The application of immunofluorescence technique with anti-insulin, anti-glucagon, anti-somatostatin, and anti-pancreatic polypeptide (PP) antisera to sections of precisely sampled regions of the human pancreas allowed the quantitative evaluation of the total content of these four endocrine cell populations in 13 nondiabetics, in 2 insulin-dependent diabetics (IDDM), and in 2 non-insulin-dependent diabetic subjects (NIDDM) of various age and sex. In nondiabetic subjects, PP-cells appear sex-related. Male individuals have a significantly greater volume of PP-cells than female. In diabetic subjects, the only marked difference as compared with nondiabetics is the reduction of insulin cell volume in IDDM. Other small differences between individual endocrine cell volumes are detectable in both IDDM and NIDDM as compared with nondiabetics, but their significance is at present unclear. The qualitative changes of islet structure accompanying insulin cell reduction in IDDM were not considered in the present Study.
Insulin Receptor Binding to Fat and Blood Cells and Insulin Action in Fat Cells from Insulin-dependent Diabetics
Authors: Pedersen Oluf , Hjøllund Elisabeth
Published: September 2013

Insulin binding to fat and blood cells and the effect of insulin on glucose transport, glucose oxidation, lipogenesis, and lipolysis in fat cells were measured in 23 conventionally treated insulin-dependent diabetics (IDDs) with a mean duration of diabetes for 10 yr. In the fasting state diabetics had increased plasma levels of free insulin (P < 0.001) accompanied by a 38% reduction of insulin binding to fat cells (P < 0.001), whereas insulin binding to monocytes and erythrocytes was normal. The concentrations of insulin causing halfmaximal effect on glucose transport and antilipolysis in adipocytes were both higher in diabetics than in normals (P < 0.001), suggesting impaired sensitivity to insulin that may be the functional consequence of the adipocyte insulin receptor defect. The basal rates and the maximal responses to insulin of glucose transport and lipolysis were both within the limits of normals, indicating the absence of postreceptor abnormalities in these effector systems. In contrast, both glucose oxidation and lipogenesis in fat cells from diabetics had normal sensitivity to insulin. This finding was very surprising and suggests possible postreceptor modulation o the insulin sensitivity of glucose metabolism in insulin-treated diabetics counterbalancing the effects of decreased insulin receptor binding. Moreover, both the basal rates for glucose oxidation and lipogenesis and the absolute response of glucose oxidation and lipogenesis rates to maximal insulin stimulation were significantly reduced in fat cells from diabetics indicating postreceptor impairments of glucose metabolism. In conclusion: In long-term-treated IDDs in usual metabolic control and with fasting, peripheral hyperinsulinemia insulin binding to circulating blood cells was normal. In contrast, a peripheral, fixed tissue, as fat cells, exhibited decreased insulin bindingwith impaired insulin sensitivity of some pathways (glucose transport and antilipolysis) and postreceptor impairments of other pathways (lipogenesis and glucose oxidation).
Glycosylated Hemoglobin in Human and Animal Red Cells: Role of Glucose Permeability
Authors: Higgins Paul J , Garlick Robert L , Bunn H Franklin
Published: September 2013

We have compared red cells from man and selected animals in order to determine the effect of glucose permeability on nonenzymatic glycosylation of hemoglobin. Glucose permeability was highest in the primates (human, baboon, rhesus monkey), lower in dogs and rabbits, and nearly zero in pigs. Glycosylation of hemoglobin was measured by three independent methods: cation-exchange chromatography on Bio-Rex 70 (Bio-Rad, Inc., Richmond, California), agar gel electrophoresis, and affinity chromatography. The colorimetric thiobarbituric acid test did not provide valid data on animal hemolysates. However, this test was useful for identifying glycosylated hemoglobin (HbA1c) components isolated on Bio-Rex chromatography. In all animals tested, levels of HbA1c (from Bio-Rex chromatography) and total glycosylated hemoglobin (from affinity chromatography) correlated well with glucose exposure, the product of intracellular glucose concentration, and red cell life span. These results indicate that nonenzymatic glycosylation of hemoglobin in mammals is determined by three major variables: mean plasma glucose concentration, red cell life span, and red cell glucose permeability.
Autoantibodies in the BB/W Rat
Authors: Like A A , Appel M C , Rossini A A
Published: September 2013

The BioBreeding/Worcester (BB/W) rat is a model of spontaneous autoimmune diabetes mellitus and lymphocytic thyroiditis. Additional features supporting an immunologic pathogenesis of the BB/W syndrome include the protective action of antilymphocyte serum, neonatal bone marrow transfusions, and neonatal thymectomy. To evaluate other manifestations of immune dysregulation, the BB/W colony was surveyed for the presence of autoantibodies to a variety of tissue and cell constituents. Anti-smooth muscle and anti-thyroid colloid antibodies were present with great frequency in diabetic animals as well as in normoglycemic offspring of diabetic parents. Anti-parietal cell antibodies were less frequent and islet cell cytoplasmic and adrenal antibodies were not detected. These data suggest that the underlying defect in the BB/W rat is more likely to be an abnormal immune regulatory system than antigenically altered target tissues (“altered self”) under attack by a normal immune surveillance system.
Therapeutic Effects of Dehydroepiandrosterone (DHEA) in Diabetic Mice
Authors: Coleman D L , Leiter E H , Schwizer R W
Published: September 2013

Dehydroepiandrosterone (OHEA), a major adrenal secretory steroid in humans, was therapeutic when fed in a concentration of 0.4% to C57BL/KsJ mice with either non-insulin-dependent or insulin-dependent diabetes. Genetically diabetic (db/db) mice of both sexes develop obesity and a glucose intolerance and hyperglycemia associated with insulin resistance by 2 mo of age, and exhibit beta-cell necrosis and islet atrophy by 4 mo. In contrast, OHEA feeding initiated between 1 and 4 mo of age, while only moderately effective in preventing obesity, did prevent the other pathogenic changes and effected a rapid remission of hyperglycemia, a preservation of beta-cell structure and function, and an increased insulin sensitivity as measured by glucose tolerance tests. DHEA feeding was also therapeutic to normal C57BL/KsJ male mice made diabetic by multiple low doses of streptozotocin (SZ). While DHEA treatments did not block either the direct cytotoxic action of SZ on beta-cells or the development of insulitis, the steroid significantly moderated the severity of the ensuing diabetes (reduced hyperglycemia and water consumption, and increased plasma insulin and numbers of residual, granulated beta-cells).
Effect of Metabolic Control on Lipid, Lipoprotein, and Apolipoprotein Levels in 55 Insulin-dependent Diabetic Patients: A Longitudinal Study
Authors: Lopes-Virella Maria F , Wohltmann Hulda J , Mayfield Ronald K , Loadholt C B , Colwell John A
Published: September 2013

Plasma lipid, lipoprotein, and apolipoprotein levels were measured in 55 insulin-dependent diabetics (20 males and 35 females) before and after 2–3 wk of intensive insulin therapy in a metabolic unit.

At the time of discharge from the metabolic unit the levels of total, low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) cholesterol as well as triglycerides, VLDL triglycerides, and apolipoprotein B (Apo B) were significantly decreased. Conversely, the levels of high-density lipoprotein (HDL) cholesterol, and apolipoprotein A1 (Apo A1) were significantly increased.

The data were further analyzed after subdividing the patients into two subgroups: (1) patients admitted in poor glycemic control (HbA1c > 11%) and (2) patients admitted in fair control (HbA1c < 11%). In the group admitted in poor control the changes in lipid and lipoprotein levels were similar to the ones found in the group of patients as a whole, while in patients admitted in fair control only the levels of total and VLDL triglycerides showed significant changes with control.

Patients' sex appeared to influence the magnitude of changes observed in HDL cholesterol and Apo A1, levels. In males a significant increase in both HDL cholesterol and Apo A1 was achieved after glycemic control either in the whole group or in the subgroup admitted in poor control. In the subgroup admitted in fair control HDL cholesterol levels rose but no significant change was observed in the Apo A1 levels. In females no significant change was observed with improved control in HDL cholesterol and Apo A1, either in the whole group or in the group admitted in fair control. A small but significant increase was detected in the HDL cholesterol levels of the female patients admitted in poor control, but no change was observed in the Apo A1 levels.

In conclusion, in insulin-dependent diabetics, normalization in plasma lipid, lipoprotein, and apolipoprotein levels was obtained after intensive insulin therapy.
Effect of Exercise and Diet on Triglyceride Metabolism in Rats with Moderate Insulin Deficiency
Authors: Dall'aglio Elisabetta , Chang Fred , Chang Helen , Stern Judith , Reaven Gerald
Published: September 2013

The ability of exercise and diet to modify the effects of moderate streptozotocin-induced insulin deficiency on triglyceride metabolism has been studied in the rat. Insulin-deficient rats allowed to run spontaneously in exercise wheel cages had significantly lower (P < 0.001) plasma glucose levels (187 ± 19 mg/dl) than either sedentary (374 ± 24 mg/dl) or sucrose-fed (450 ± 13 mg/dl) diabetic rats, despite the fact that plasma insulin levels were comparable in all these groups. Plasma triglyceride (TG) levels in exercise-trained rats with diabetes (51 ± 5 mg/dl) were actually lower than in control rats with normal glucose tolerance (90 ± 14 mg/dl). In contrast, plasma TG levels were higher than control levels in diabetic sedentary rats (128 ± 11 mg/dl), and severe hypertriglyceridemia developed in sucrose-fed diabetic rats (369 ± 35 mg/dl). The ability of exercise training to attenuate diabetic hypertriglyceridemia, which was observed in both chow-fed and sucrose-fed rats, was secondary to a decrease in TG secretion, and appeared to be related to lower plasma FFA concentrations. In contrast, the accentuation of diabetic hypertriglyceridemia seen in sucrose-fed rats was related to a defect in TG catabolism. Adipose tissue lipoprotein lipase (LPL) activities were essentially identical in all diabetic rats, suggesting that the observed difference in TG kinetics could not be attributed to concomitant increases or decreases in adipose tissue LPL activity. These results emphasize the powerful impact of exercise and diet on TG metabolism in rats with moderate degrees of insulin deficiency.
Lack of Glucagon Response to Hypoglycemia in Long-Term Experimental Diabetic Rats
Authors: Patel D G
Published: September 2013

Glucagon and catecholamine responses to insulin-induced hypoglycemia were investigated in streptozotocin-diabetic rats at various times after streptozotocin administration and in age-matched control male rats. Diabetic rats had basal glucagon levels higher than those in control rats, while basal epinephrine and norepinephrine levels were essentially identical. As the duration of diabetes increased, the glucagon and epinephrine responses to insulin hypoglycemia decreased. The response of control rats was not correlated with age. Increases in plasma norepinephrine values in response to hypoglycemia were similar in both diabetic and control rats. The data indicate a concurrent impaired response of glucagon and epinephrine release in response to insulin-induced hypoglycemia in streptozotocin-diabetic rats as the duration of diabetes prolongs.
No Evidence of Amyloidosis in Type I Diabetics Treated with Continuous Subcutaneous Insulin Infusion
Authors: Koivisto Veikko A , Teppo Anna-Maija , Maury C Peter J , Taskinen Marja-Riitta
Published: September 2013

A recent study has demonstrated secondary amyloidosis in dogs treated with continuous intravenous insulin infusion. Since elevated levels of serum amyloid A protein (SAA) and diminished amyloid fibril degrading activity (AFDA) are associated with amyloidosis, we measured SAA and AFDA in ten type I diabetics treated with continuous subcutaneous insulin infusion and in five conventionally treated patients. Only one pump- and one conventionally treated patient had detectable but low SAA levels, comparable with these seen in healthy controls. In patients with secondary amyloidosis the mean SAA level was 24-fold higher than in controls (P < 0.001). Similarly, in both diabetic groups, AFDA was normal whereas it was reduced by 41% in patients with amyloidosis (P < 0.001). Furthermore, no local amyloidosis was seen at the infusion site in any of the patients studied. Thus, our data fail to provide any evidence of secondary amyloidosis in patients treated for 3–40 mo with continuous subcutaneous insulin infusion.