Mini dental assessment: a simple screening test for non-dental staff.

OBJECTIVE: The objective of this study was to develop a simple tool for the assessment of possible dental treatment needs (DTN) for non-dental professionals (Mini Dental Assessment, MDA). To keep the assessment universal, we aimed to base it on the patient's history and a simple chewing efficiency test (CET) as the dental status is a known determinant for chewing efficiency. MATERIALS & METHODS: The assessment was developed using data from 169 patients from two sites (University Hospital Giessen, St. Bonifatius Hospital Lingen, both Germany). In all patients, a dental examination was performed, the denture status was evaluated (based on the California Dental Association criteria; CDA criteria), and the DTN was determined. In addition, the time since the patient's last visit to a dentist (TLVD) and denture age (DA) were assessed. Furthermore, a CET was carried out and the comminution score was determined (CETS). RESULTS: In total, 108 patients required dental treatment. The mean value (±SD) was 2.9 ± 0.9 score points for the DTN, 2.5 ± 3.8 years for the TLVD, and 10.8 ± 8.9 years for the DA. There was a significant correlation (Spearman, P < .05) between the DTN and degree of comminution (3.4 ± 1.8). Based on the results of the statistical analysis, the intended assessment tool was developed using the variables CETS, TLVD, and DA weighed by their respective regression coefficients (10:3:1). Subsequently, the resulting MDA score (51.32 ± 28.14) was calculated. A sensitivity/specificity analysis was conducted and a receiver operating characteristic curve was calculated (SPSS 17.0, area under curve 0.805; 95 % CI 0.738-0.873). CONCLUSION: It can be concluded that the dental status of elderly patients is reflected in the outcome of the MDA. However, ongoing validation is needed. TRIAL REGISTRATION: DRKS00003219.

Prevalence of diabetes mellitus secondary to pancreatic diseases (type 3c).

BACKGROUND: Diabetes mellitus secondary to pancreatic diseases is a condition seldom thought of in clinical practice. Yet, a high percentage of exocrine pancreatic insufficiency has been reported for the general population and especially for diabetic subjects. Thus, we investigated the prevalence of diabetes mellitus due to pancreatic diseases. METHODS: In this study, we investigated 1868 patients diagnosed with diabetes mellitus who had been admitted to our hospital during the last 24 months. Patient data were diligently studied, and patients were reclassified according to the diabetes classification as proposed by the American Diabetes Association. RESULTS: Among 1868 subjects, 172 patients could be classified as type 3c diabetes mellitus (9.2%). Among these were 135 diagnosed with chronic pancreatitis (78.5%), 12 with hereditary haemochromatosis, 14 with pancreatic cancer and 7 with cystic fibrosis. Thus, diabetes mellitus due to chronic pancreatitis occurred in this collective in 7.2% of all diabetic subjects. Misclassification of these patients was very common. Only 51.2% (88/172) were initially classified correctly. Most type 3 diabetes patients were initially misclassified as type 2 diabetes (69/84). CONCLUSIONS: Diabetes mellitus secondary to pancreatic diseases (especially chronic pancreatitis) seems more common than generally believed with a prevalence of 9.2% among the subjects studied here. Because the awareness of this diabetes type is poor, misclassification is quite frequent. A common problem seems to be the differentiation between type 2 and type 3. Yet, the right classification of diabetes mellitus is important, because there are special therapeutic options and problems in patients with diabetes secondary to pancreatic diseases.

Profile of gastrointestinal involvement in patients with systemic sclerosis.

Systemic sclerosis (SSc) is a chronic autoimmune connective tissue disease. Of the numerous organ manifestations, involvement of the upper and lower gastrointestinal tract (GIT) appears to be the most frequent with regard to the clinical symptoms. However, as the frequency and clinical relevance of GI involvement in patients with SSc are not known in detail, the German network of the systemic sclerosis (DNSS) has developed a detailed questionnaire to evaluate the extent and profile of gastrointestinal involvement in SSc patients. The multi-symptom questionnaire was used at baseline and after 1 year in registered patients of the DNSS. In addition, the results were compared with gastrointestinal disorders in patients with SSc and other rheumatic diseases, as well as with the medical history of the patients. In total, 90 patients were included in the study. The results of the study show that in reality, a much higher (nearly all) percentage of (98,9%) patients than expected suffer from GI-symptoms, regardless of the stage of their disease. Of these, meteorism (87,8%) was the most common followed by coughing/sore voice (77,8%), heartburn (daytime 68,9%, nighttime 53,3%), diarrhea (67,8%), stomach ache (68,9%) and nausea (61,1%). Although SSc patients were treated according to the respective recommendations, only limited improvements with regard to GI-symptoms could be achieved after 1 year of follow-up. In addition, the study revealed that the multi-symptom questionnaire is a useful tool to contribute to identify the gastrointestinal sequelae in systemic sclerosis.

Improved intraportal islet transplantation outcome by systemic IKK-beta inhibition: NF-κB activity in pancreatic islets depends on oxygen availability.

Intraportal islet transplantation suffers from low efficiency caused by substantial islet mass loss after transplantation. How this process is regulated is still unclear. Here, we show that NF-κB activation was detectable in islet grafts shortly after transplantation of porcine islets to diabetic NMRI nu/nu mice, and systemic NF-κB inhibition in transplanted animals significantly prolonged islet graft survival. Proinflammatory cytokines alone did not cause evident cell death in pancreatic islet within 24 h, while the combination of cytokines with hypoxia resulted in a strong induction of cell death that could be blocked dose-dependently by a selective IKK-ß inhibitor. Under hypoxia, NF-κB activity impaired expression of antiapoptotic gene BCL-xL, c-FLIP and survivin. NF-κB activation in isolated islets was reduced by hypoxia in a time-dependent manner, accordingly, NF-κB activation in transplanted islets diminished by time. Our data indicate that, while NF-κB has an antiapoptotic role under normoxia, low oxygen conditions decrease its activity and transform it to a proapoptotic transcription factor in pancreatic islets. We conclude that NF-κB inhibition represents a potential strategy to improve islet transplantation efficiency.

Determinants of Exocrine Pancreatic Function as Measured by Fecal Elastase-1 Concentrations (FEC) in Patients with Diabetes mellitus.

OBJECTIVE: Recently it has been shown that there is not only endocrine insufficiency in diabetic patients, but a frequent co-morbidity of both, the endocrine and exocrine pancreas. The present study was performed to further analyse the determinants of exocrine pancreatic function in patients with diabetes mellitus. METHODS: The records of 1992 patients with diabetes mellitus who had been treated in our hospital during a 2-year period were re-evaluated. Defined parameters were documented in standardized data sheets. Records were further checked for the results of imaging procedures of the pancreas. In 307 patients FEC had been performed and documented. Only these patients were included in further evaluation. RESULTS: FEC was inversely correlated with diabetes duration and HbA1c-levels but not with age. C-peptide levels correlated positively with FEC. BMI and FEC were also significantly correlated. There was no correlation between diabetes therapy and exocrine pancreatic function as there was no correlation with any concomitant medication. The presence of diabetes-associated antibodies was not related to FEC. According to the documented data 38 were classified as type-1 diabetes (12.4%), 167 as type-2 (54.4%), and 88 patients met the diagnostic criteria of type-3 (28.7%). Fourteen patients could not be classified because of lacking information (4.6%). CONCLUSIONS: Exocrine insufficiency might be explained as a complication of diabetes mellitus. However, it is more likely that type-3 diabetes is much more frequent than previously believed. Consequently the evaluation of exocrine function and morphology should be included into the clinical workup of any diabetic patient at least at the time of manifestation.

Insulin binding to antibodies is a risk factor for inexplicable severe hypoglycaemia in children with type-1 diabetes mellitus.

BACKGROUND: Type-1 diabetic individuals differ with regard to both, the formation of circulating insulin antibodies, and the incidence of severe hypoglycaemia. AIM OF THE STUDY: To assess the association of insulin binding to antibodies with the incidence of severe hypoglycaemia. PATIENTS AND METHODS: In a cross sectional study, 73 children with type-1 diabetes mellitus (median age 14 years, duration of diabetes 6 years) were investigated, 22 of whom had experienced severe hypoglycaemia during the past 18 months, and 51 had never experienced severe hypoglycaemia. Of the patients with severe hypoglycaemia 16 had experienced severe unexplained hypoglycaemias, and 6 had experienced severe hypoglycaemias which were explicable (by missed meals, unplanned physical exercise etc.). Insulin binding was measured in a blinded central laboratory by radioimmunoassay, and expressed as ratio bound/unbound insulin; a binding >15% was considered relevant insulin binding. RESULTS: A total of 38 patients displayed relevant insulin binding (17 of whom had experienced severe hypoglycaemia), and 35 patients did not (5 of whom had experienced severe hypoglycaemia; p=0.0055, Fisher's exact test). Patients with relevant insulin binding were younger (12.2 vs 14.5 years, p=0.006) than patients without relevant insulin binding. From the 16 patients with inexplicable severe hypoglycaemia, 15 displayed relevant insulin binding, compared to 2 of the 6 patients with explicable severe hypoglycaemia (p=0.009). The association of any severe hypoglycaemia, and of inexplicable severe hypoglycaemia, with relevant insulin binding was significant (odds ratio 4.8 (95%CI 1.5-15.2), and 22.1(95%CI 2.7-179.6), p<0.006). Patients with/without relevant insulin binding, or with/without severe hypoglycaemia, did not differ significantly regarding sex, duration of diabetes, number of insulin injections per day, HbA1c and C-peptide levels (ANOVA). CONCLUSION: Insulin binding to antibodies >15% appears to be a strong risk factor for inexplicable severe hypoglycaemias in type-1 diabetic children.

Benfotiamine in diabetic polyneuropathy (BENDIP): results of a randomised, double blind, placebo-controlled clinical study.

AIM: Efficacy and safety of benfotiamine in treatment of diabetic polyneuropathy. METHODS: Double blind, placebo-controlled, phase-III-study. 181 patients were screened. 165 patients with symmetrical, distal diabetic polyneuropathy were randomised to one of three treatment groups entering the wash-out phase and 133/124 patients were analysed in the ITT/PP analysis: Benfotiamine 600 mg per day (n=47/43), benfotiamine 300 mg per day (n=45/42) or placebo (n=41/39). RESULTS: After 6 weeks of treatment, the primary outcome parameter NSS (Neuropathy Symptom Score) differed significantly between the treatment groups (p=0.033) in the PP (per protocol) population. In the ITT (intention to treat) population, the improvement of NSS was slightly above significance (p=0.055). The TSS (Total Symptom Score) showed no significant differences after 6 weeks of treatment. The improvement was more pronounced at the higher benfotiamine dose and increased with treatment duration. In the TSS, best results were obtained for the symptom "pain". Treatment was well tolerated in all groups. CONCLUSION: Benfotiamine may extend the treatment option for patients with diabetic polyneuropathy based on causal influence on impaired glucose metabolism. Further studies should confirm the positive experiences.

Growth hormone and bone mineral densitiy in HIV-1-infected male subjects.

The aim of this study was to characterize the GH-IGF-I axis of patients with HIV-1-infection without any symptoms of AIDS-associated wasting. A special emphasis was placed on determine bone mineral density (BMD) and biochemical markers of bone metabolism. Therefore 42 male fasting HIV-1-infected outpatients were included and estimation of serum GH, IGF-I, IGFBP-1 and 3, osteocalcin, TNF-alpha, 1,25dihydroxycholecalciferol, and endocrine markers of the gonad function by commercially available RIA's performed. DEXA-measurements of the lumbar spine and the Ward's triangle of the left hip were done. The GH, IGF-1, IGFBP-1 and 3 serum levels were within the normal range Performing Spearman-correlation test, we established significance between IGF-I serum levels and BMD lumbar spine and Ward's triangle (p < 0.01, p < 0.05), CD4 cell-count (p < 0.05), 1,25dihydroxycholecalciferol (p < 0.05), osteocalcin (p < 0.05), TNF-alpha (p < 0.05), body mass index (BMI) (p < 0.05) and total testosterone (p < 0.01). IGFBP-1 correlates both inversely significantly with CD4 cell-count (p < 0.05) and serum-calcium (p < 0.05). The IGFBP-3 correlates with BMI (p < 0.05) and serum osteocalcin (p < 0.05). Correlation both with markers of bone metabolism and vitamin D metabolites showed the important role of GH/IGF-I axis in modulating the availability of calcium in chronic conditions. This axis may be in a part responsible for the manifestation of the HIV-associated osteopenia.

Parathormone levels and Vitamin D metabolism in female patients with various grades of fecal elastase 1 deficiency.

BACKGROUND: There are still too few conclusive reports about conspicuous parathormone (PTH) and Vitamin D metabolism in patients with fecal elastase 1 deficiency or any connection of the calcium metabolism to the severity of exocrine pancreas insufficiency. METHODS: Between March 1998 and September 2002, we investigated on 240 female patients with fecal elastase 1 deficiency at an average age of approx. 56.4 years and suffering from meteorism and weight loss as well as on age matched 80 healthy female controls. Serum levels of PTH, total calcium, D subset3-vitamins, calcitriol and calcefediol, as well as the concentration of fecal elastase 1 were determined in patients and controls. RESULTS: In 240 female patients with deficiency of fecal elastase 1 only two patients show milder cases of new diagnosed primary hyperparathyroidism. Calcitriol was markedly decreased (14.3 +/- 6.1 and 20.7 +/- 9.4 pg/ml) compared to controls (41.8 +/- 8.3 pg / ml) ( p < 0.01). Calcefediol was not significantly different within the various elastase-groups (p = 0.07). Nevertheless, vitamin D subset3 and fecal elastase 1 in patients correlated significantly (p < 0.01) and, compared to controls, both were extremely low (means in patients. Both D subset3-vitamins in patients were significantly lower when elastase 1 in feces was under 200 microg/g compared to the others (for calcitriol p < 0.05, for calcefediol p < 0.05). CONCLUSION: In female patients elastase 1 in feces confirm the grade of vitamin D supply, and thus show a vitamin D subset3-deficiency, depending on the loss of stool content. There seems to be a connection here between the loss of exocrine function and may be even the characteristic of sterol-binding of elastase 1 in the pancreas, which seems to be relevant for vitamin D-supply.

Metabolic effects of successful intraportal islet transplantation in insulin-dependent diabetes mellitus.

The intraportal injection of human pancreatic islets has been indicated as a possible alternative to the pancreas transplant in insulin-dependent diabetic patients. Aim of the present work was to study the effect of intraportal injection of purified human islets on: (a) the basal hepatic glucose production; (b) the whole body glucose homeostasis and insulin action; and (c) the regulation of insulin secretion in insulin-dependent diabetes mellitus patients bearing a kidney transplant. 15 recipients of purified islets from cadaver donors (intraportal injection) were studied by means of the infusion of labeled glucose to quantify the hepatic glucose production. Islet transplanted patients were subdivided in two groups based on graft function and underwent: (a) a 120-min euglycemic insulin infusion (1 mU/kg/min) to assess insulin action; (b) a 120-min glucose infusion (+75 mg/di) to study the pattern of insulin secretion. Seven patients with chronic uveitis on the same immunosuppressive therapy as grafted patients, twelve healthy volunteers, and seven insulin-dependent diabetic patients with combined pancreas and kidney transplantation were also studied as control groups. Islet transplanted patients have: (a) a higher basal hepatic glucose production (HGP: 5.1 +/- 1.4 mg/kg/ min; P < 0.05 with respect to all other groups) if without graft function, and a normal HGP (2.4 +/- 0.2 mg/kg/min) with a functioning graft; (b) a defective tissue glucose disposal (3.9 +/- 0.5 mg/kg/min in patients without islet function and 5.3 +/- 0.4 mg/kg/min in patients with islet function) with respect to normals (P < 0.01 for both comparisons); (c) a blunted first phase insulin peak and a similar second phase secretion with respect to controls. In conclusion, in spite of the persistence of an abnormal pattern of insulin secretion, successful intraportal islet graft normalizes the basal HGP and improves total tissue glucose disposal in insulin-dependent diabetes mellitus.

Alterations of vitamin D3 metabolism in young women with various grades of chronic pancreatitis.

BACKGROUND: There are still too few conclusive reports about conspicuous vitamin D-deficiency in young female patients with chronic pancreatitis, or any connection of the deficiency to the severity of the disease. Therefore the aim of this study was to examine marker of vitamin D3 metabolism in female patients with episode of biliary pancreatitis to determine if increased severity of the disease would correlate with impaired vitamin D3 metabolism. METHODS: Between 1996 and 2003, we investigated 53 premenopausal patients with an average age of approximately 33 years suffering from an episode of chronic pancreatitis, as well as 30 female healthy controls with an average age of 32.4 years. The severity of chronic pancreatitis in patients was determined via endoscopic retrograde cholangiopancreaticography (ERCP) and assigned to 1 of 3 grades based on the Cambridge classification. Additional parameter assessed were demographics, smoking, consumption of alcohol and CD-transferrin, fasting metabolic parameters, biochemical markers of vitamin D3 metabolism and fecal elastase 1. None of the patients received hormone replacement therapy, Vitamin D or Calcium-supplementation. RESULTS: The serum levels of 1,25-dihydroxyvitamin D [1,25(OH2)D] were significantly reduced compared to female healthy controls. Fecal elastase 1 correlated with this classification of severity of chronic pancreatitis (p < 0.01). Furthermore, fecal elastase 1 of patients correlated the same way with both D-vitamins (p <0.01). The level of both D3 vitamins in patients were significantly lowered when the content of fecal elastase 1 was under 200 microg/g compared to the others [for 1,25-(OH2)D3 p < 0.01; 25-OH- D3 p < 0.01]. CONCLUSION: Premenopausal patients with chronic pancreatitis are at risk of developing decreased levels of 1,25(OH2)D3. This fact may contribute to a negative calcium balance and alteration of bone metabolism. Therefore, ERCP and fecal elastase 1 verify the severity grade of a chronic pancreatitis, and thus show a vitamin D3 deficiency in young women, depending on the progress of disease.

Adiponectin is functionally active in human islets but does not affect insulin secretory function or beta-cell lipoapoptosis.

CONTEXT: The adipokine adiponectin has insulin-sensitizing, antiatherogenic, and antiinflammatory properties. Mouse and human adiponectin receptor-1 and -2 have been cloned, both of which are expressed in various tissues and mediate effects of globular and full-length adiponectin. Whether adiponectin affects insulin secretion and beta-cell apoptosis and whether plasma adiponectin is associated with beta-cell function in humans is under investigation. DESIGN AND METHODS: In human islets from multiorgan donors, we investigated expression of adiponectin receptor-1 and -2. Furthermore, glucose-stimulated insulin secretion was determined by RIA. In addition, we investigated fatty acid-induced beta-cell apoptosis by terminal dUTP nick end labeling and flow-cytometric cell cycle analysis (sub-G1 formation). In humans in vivo, insulin secretory function was measured during hyperglycemic clamps in 65 normal glucose-tolerant subjects. We determined first and second phase of glucose-stimulated, glucagon-like peptide-1-stimulated, and arginine-stimulated insulin secretion. RESULTS: Adiponectin receptor-1 and -2 are expressed in human islets at the mRNA and protein level. Moreover, full-length adiponectin induces phosphorylation of acetyl coenzyme A carboxylase. However, adiponectin did not affect basal or glucose-stimulated insulin secretion or basal or fatty acid-induced beta-cell apoptosis. In vivo, fasting plasma adiponectin concentrations were not associated with glucose-stimulated first- and second-phase insulin secretion or with glucagon-like peptide-1- or arginine-stimulated insulin secretion (all P > 0.42). CONCLUSIONS: These data support a regulatory role of adiponectin in human islets; however, adiponectin does not seem to affect insulin secretion or basal/fatty acid-induced beta-cell apoptosis in humans.

Upregulation of the vascular endothelial growth factor/vascular endothelial growth factor receptor system in experimental background diabetic retinopathy of the rat.

Vascular endothelial growth factor (VEGF) is a major contributor to retinal neovascularization. The possible participation of VEGF and its high-affinity tyrosine kinase receptors, flk-1 and flt-1, in early background diabetic retinopathy was studied in the streptozotocin-induced diabetic rat model of experimental retinopathy using in situ hybridization, blotting techniques, and immunohistochemistry. Diabetic retinopathy was assessed by quantitative morphometry of retinal digest preparations. The number of acellular capillaries increased 2.7-fold in diabetic animals with diabetes' duration of 6 months compared with nondiabetic controls. VEGF expression was not detectable by in situ hybridization in nondiabetic rats but was highly increased in the ganglion cell layer and in the inner and outer nuclear layers of retinas from diabetic animals. VEGF protein was extractable only from diabetic retinas, and a strong immunolabeling was detected in vascular and perivascular structures. Increased flk-1 and flt-1 mRNA levels were also found in the ganglion cell and both nuclear layers of diabetic samples only. Dot blot and Western blot analyses confirmed the increase in flk-1 mRNA and protein in diabetic retinas. Also, flk-1 immunoreactivity was associated with vascular and nonvascular structures of the inner retinas from diabetic animals. These data obtained from a rodent model in which retinal neovascularization does not occur support the concept that the VEGF/VEGF receptor system is upregulated in early diabetic retinopathy.

Bovine islets of Langerhans. Potential source for transplantation?

Two methods are described for large-scale isolation of islets from the bovine pancreas. With the single-endpoint technique the average number of islets isolated from a 73.3-g pancreas sample was 150,560, representing an estimated total islet volume of 0.391 ml. Pancreases processed by the continuous digestion-filtration method yielded an average of 246,229 islets from a 93.9-g pancreas sample, representing an estimated total islet volume of 0.458 ml. Isolated bovine pancreatic islets demonstrated a well-preserved endocrine cell ultrastructure, responded to acute stimulation with propionic acid, and temporarily reversed experimental diabetes in mice.

Progressive islet graft failure occurs significantly earlier in autoantibody-positive than in autoantibody-negative IDDM recipients of intrahepatic islet allografts.

Alloimmunity has been uncovered to be a cause of graft loss representing a major barrier for clinical islet transplantation, and several studies are designed to evaluate new strategies for immunosuppression to prevent alloimmunity. In contrast, the significance for autoimmune destruction of transplanted beta-cells has remained somewhat controversial. Recently, two case reports based on histological findings have suggested recurrent autoimmune insulitis despite immunosuppressive therapy both in clinical pancreas and in islet transplantation. In the present study, in 23 islet-grafted patients with IDDM receiving standard immunosuppressive therapy, we demonstrate that progressive impairment of islet graft function occurs significantly earlier in those individuals positive for autoantibodies as a typical stigma of diabetes-associated autoimmunity that is well established in the prediabetic periods of IDDM. Intraportal infusion of allogeneic islets was performed in 23 C-peptide-negative IDDM patients, according to the clinical transplantation categories defined as islet after kidney (IAK) or simultaneous islet and kidney (SIK). Complete islet graft failure was defined as the 1st day of permanent C-peptide negativity in the serum (<0.2 ng/ml) and C-peptide negativity in the urine (<2 microg/dl). The median observation period following islet transplantation was 12 months (range 1-50) with a cumulative follow-up of 336 months. Islet cell antibodies (ICAs) and GAD65 antibodies were monitored before and regularly after islet transplantation. Kaplan-Meier survival analysis and log-rank statistics revealed a significant (P < 0.05) difference in cumulative islet graft survival depending on the presence of islet cell and/or GAD65 antibodies. These results strongly suggest that recurrent autoimmunity directed to transplanted beta-cells contributes to islet graft failure despite sustained immunosuppression. For successful clinical islet transplantation in the future, new immunosuppressive therapies are needed to prevent both alloimmunity and autoimmunity.

Persistent reversal of diabetes by transplantation of fetal pig proislets into nude mice.

Facing the limited availability of human adult and fetal pancreases, fetal pig proislets (pancreatic islet precursors) were investigated in view of several inherent advantages. Six litters of fetuses of mean +/- SE gestational age 75 +/- 3 days were obtained from commercially available farm pigs. Pancreatic tissue was gently digested with collagenase, then a 10-day culture was performed. During culture, fetal proislets showed no insulin response to glucose alone but a significant response to glucose plus theophylline. The insulin content per microgram of DNA in the cultured proislets continuously increased. Histological examination by immunoperoxidase staining showed that, apart from single insulin- and glucagon-positive cells, there were no discrete islets in the pancreatic tissue and the cultured proislets. Diabetes was induced with streptozocin (STZ) in eight nude mice 3-4 wk after proislet transplantation and in another eight nude mice without transplantation. During the initial week, blood glucose levels of mice in both groups increased rapidly. The mean +/- SE peak value of blood glucose levels in the transplanted group was 20.4 +/- 2.0 mM and was 20.1 +/- 1.3 mM in the group without transplantation. Simultaneously, body weight decreased from 29.5 +/- 0.7 to 21.5 +/- 0.9 g and from 27.9 +/- 0.7 to 19 +/- 1 g in the groups, respectively. Afterward, blood glucose levels of mice in the transplanted group gradually decreased, and normoglycemia was achieved in all mice within 50 +/- 13 days after injection of STZ, i.e., 74 +/- 13 days after transplantation. The group without transplantation persistently maintained blood glucose levels greater than 16.7 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

Fish oil-enriched diet and reduction of low-dose streptozocin-induced hyperglycemia. Inhibition of macrophage activation.

Repeated low doses of streptozocin (STZ; 40 mg/kg, 5 injections/day) induce hyperglycemia in certain strains of mice after a latency of 1 wk. Omega-3 polyunsaturated fatty acids (omega 3FA) have been reported to suppress immune processes by blockade of the cyclooxygenase pathway of arachidonic acid metabolism. We investigated the effects of diets high in omega 3FA on the development of diabetes in the low-dose STZ-induced diabetes (LDSTZ-D) model. Male C57BL/6J mice were on a fish oil diet (FOD) as a source of omega 3FA 8 wk before STZ injection. Controls received laboratory chow only or a coconut oil diet (COD). Blood glucose levels in FOD mice were reduced (12.5 vs. 28 mM for COD mice, P less than .001) 60 days after STZ injection with a diet in which 20% of the calories were from fish oil. In FOD mice, immunohistology showed reduced numbers of class II antigen-expressing cells in pancreatic islets followed by a decreased extent of insulitis. FOD significantly decreased the number of Fc receptor-negative dendritic cells in cytospin preparations of islets isolated from diabetic mice. Interleukin 1-like activity of peritoneal exudate cell supernatants isolated from mice on FOD was reduced. FOD did not improve insulin secretion of isolated islets from LDSTZ-D mice. These data indicate a beneficial effect of FOD on the immune component of the mouse LDSTZ-D model.

Incompatibility between human blood and isolated islets of Langerhans: a finding with implications for clinical intraportal islet transplantation?

The remarkable difference in success rates between clinical pancreas transplantation and islet transplantation is poorly understood. Despite the same histocompatibility barrier and similar immunosuppressive treatments in both transplantation procedures, human intraportal islet transplantation has a much inferior success rate than does vascularized pancreas transplantation. Thus far, little attention has been directed to the possibility that islets transplanted into the blood stream may elicit an injurious incompatibility reaction. We have tested this hypothesis in vitro with human islets and in vivo with porcine islets. Human islets were exposed to nonanticoagulated human ABO-compatible blood in surface-heparinized polyvinyl chloride tubing loops. Heparin and/or the soluble complement receptor 1 (sCR1) TP10 were tested as additives. Adult porcine islets were transplanted intraportally into pigs, and the liver was recovered after 60 min for immunohistochemical staining. Human islets induced a rapid consumption and activation of platelets. Neutrophils and monocytes were also consumed, and the coagulation and complement systems were activated. Upon histological examination, islets were found to be embedded in clots and infiltrated with CD11+ leukocytes. Furthermore, the cellular morphology was disrupted. When heparin and sCR1 were added to the blood, these events were avoided. Porcine islets retrieved in liver biopsies after intraportal islet allotransplantation showed a morphology similar to that of human islets perifused in vitro. Thus, exposure of isolated islets of Langerhans to allogenic blood resulted in significant damage to the islets, a finding that could explain the unsatisfactory clinical results obtained with intraportal islet transplantation. Because administration of heparin in combination with a soluble complement receptor abrogated these events, such treatment would presumably improve the outcome of clinical islet transplantation by reducing both initial islet loss and subsequent specific immune responses.

Metabolic effects of restoring partial beta-cell function after islet allotransplantation in type 1 diabetic patients.

Successful intraportal islet transplantation normalizes glucose metabolism in diabetic humans. To date, full function is not routinely achieved after islet transplantation in humans, with most grafts being characterized by only partial function. Moreover, the duration of full function is variable and cannot be sufficiently predicted with available methods. In contrast, most grafts retain partial function for a long time. We hypothesized that partial function can restore normal protein and lipid metabolism in diabetic individuals. We studied 45 diabetic patients after islet transplantation. Labeled glucose and leucine were infused to assess whole-body glucose and protein turnover in 1) 6 type 1 diabetic patients with full function after intraportal islet transplantation (FF group; C-peptide > 0.6 nmol/l; daily insulin dosage 0.03 +/- 0.02 U x kg(-1) body wt x day(-1); fasting plasma glucose < 7.7 mmol/l; HbA1c < or = 6.5%), 2) 17 patients with partial function (PF group; C-peptide > 0.16 nmol/l; insulin dosage < 0.4 U x kg(-1) body wt x day(-1)), 3) 9 patients with no function (NF group; C-peptide < 0.16 nmol/l; insulin dosage > 0.4 U x kg(-1) body wt x day(-1)), and 4) 6 patients with chronic uveitis as control subjects (CU group). Hepatic albumin synthesis was assessed in an additional five PF and five healthy volunteers by means of a primed-continuous infusion of [3,3,3-2H3]leucine. The insulin requirement was 97% lower than pretransplant levels for the FF group and 57% lower than pretransplant levels for the PF group. In the basal state, the PF group had a plasma glucose concentration slightly higher than that of the FF (P = 0.249) and CU groups (P = 0.08), but was improved with respect to the NF group (P < 0.01). Plasma leucine (101.1 +/- 5.9 micromol/l) and branched-chain amino acids (337.6 +/- 16.6 micromol/l) were similar in the PF, FF, and CU groups, and significantly lower than in the NF group (P < 0.01). During insulin infusion, the metabolic clearance rate of glucose was defective in the NF group versus in the other groups (P < 0.01). Both the basal and insulin-stimulated proteolytic and proteosynthetic rates were comparable in the PF, FF, and CU groups, but significantly higher in the NF group (P = 0.05). In addition, the PF group had a normal hepatic albumin synthesis. Plasma free fatty acid concentrations in the PF and FF groups were similar to those of the CU group, but the NF group showed a reduced insulin-dependent suppression during the clamp. We concluded that the restoration of approximately 60% of endogenous insulin secretion is capable of normalizing the alterations of protein and lipid metabolism in type 1 diabetic kidney recipients, notwithstanding chronic immunosuppressive therapy. The results of the present study indicate that "success" of islet transplantation may be best defined by a number of metabolic criteria, not just glucose concentration/metabolism alone.

Angiogenic capacity of endothelial cells in islets of Langerhans.

Transplantation of pancreatic islets reconstitutes glucose homeostasis in diabetes mellitus. Before transplantation, islets are disrupted from the surrounding blood vessels by the isolation procedure, with the grafted tissue being subject to ischemic damage. The survival of transplanted islets is assumed to depend on effective revascularization. Perfusion studies suggest that newly formed microvessels supplying the graft with nutrients are exclusively rebuilt by the host. It is generally not known whether isolated islets contain endothelial cells (EC), which potentially participate in the revascularization process. Therefore, we tried to detect immature EC in isolated islets by transformation with polyoma middle T antigen. Endothelioma cells were generated, implicating the presence of de-differentiated EC within isolated islets. When embedded in a fibrin gel, the islets developed cellular cords consisting of EC, whereas FGF-2 and VEGF stimulated the formation of cord-like structures. Furthermore, we studied the presence of donor EC in islet grafts by using transgenic mice with an EC lineage-specific promotor-LacZ reporter construct (Tie-2LacZ). Following islet transplantation, Tie-2LacZ-positive EC of both donor and recipient were identified in the vicinity of or within the graft up to 3 wk after transplantation. In conclusion, EC and/or their progenitors with angiogenic capacity reside within isolated islets of different species, and their proliferative potential can be stimulated by various inducers. These graft-related endothelia persist after islet transplantation and are integrated within newly formed microvessels.