Aims/hypothesis We sought to establish the extent and basis for adaptive changes in beta cell numbers in human pregnancy. Methods Pancreas was obtained at autopsy from women who had died while ...pregnant (n = 18), post-partum (n = 6) or were not pregnant at or shortly before death (controls; n = 20). Pancreases were evaluated for fractional pancreatic beta cell area, islet size and islet fraction of beta cells, beta cell replication (Ki67) and apoptosis (TUNEL), and indirect markers of beta cell neogenesis (insulin-positive cells in ducts and scattered beta cells in pancreas). Results The pancreatic fractional beta cell area was increased by ∼1.4-fold in human pregnancy, with no change in mean beta cell size. In pregnancy there were more small islets rather than an increase in islet size or beta cells per islet. No increase in beta cell replication or change in beta cell apoptosis was detected, but duct cells positive for insulin and scattered beta cells were increased with pregnancy. Conclusions/interpretation The adaptive increase in beta cell numbers in human pregnancy is not as great as in most reports in rodents. This increase in humans is achieved by increased numbers of beta cells in apparently new small islets, rather than duplication of beta cells in existing islets, which is characteristic of pregnancy in rodents.
Background: The resistance of platelet‐rich thrombi to fibrinolysis is generally attributed to clot retraction and platelet PAI‐1 release. The role of TAFI in platelet‐mediated resistance to lysis is ...unclear. Objective: We investigated the contribution of TAFI to the antifibrinolytic effect of platelets in whole blood by thromboelastography. Methods: Platelet‐poor (PP‐WB, < 40 × 103 μL−1) and platelet‐rich (PR‐WB, > 400 × 103 μL−1) blood samples were obtained from normal human blood (N‐WB, 150–220 × 103 μL−1). Clot lysis time was measured by thromboelastography in recalcified blood supplemented with t‐PA (100 ng mL−1) and tissue factor (1:1000 Recombiplastin). Results: t‐PA‐induced lysis time increased in parallel with platelet concentration (up to 3‐fold). Neutralization of TAFI, but not of PAI‐1, shortened the lysis time by ∼ 50% in PR‐WB and by < 10% in PP‐WB. Accordingly, prothrombin F1+2 and TAFIa accumulation was greater in PR‐WB than in PP‐WB. A similar TAFI‐dependent inhibition of fibrinolysis was observed when clot retraction was prevented by cytochalasin D or abciximab, or when platelet membranes were tested. Moreover, in blood with an intact contact system, platelet‐mediated fibrinolysis resistance was attenuated by an anti‐FXI but not by an anti F‐XII antibody. Finally, platelets made the clots resistant to the profibrinolytic effect of heparin concentrations displaying a strong anticoagulant activity. Conclusions: Our data indicate that TAFI activation is one major mechanism whereby platelets make clots resistant to fibrinolysis and underscore the importance of TAFI inhibitors as new antithrombotic agents.
Aims/hypothesis
In a high-fat-fed rat model of type 2 diabetes we noted increased exocrine duct replication. This is a predisposing factor for pancreatitis and pancreatic cancer, both of which are ...more common in type 2 diabetes. The aim of the study reported here was to establish if obesity and/or type 2 diabetes are associated with increased pancreatic ductal replication in humans.
Methods
We obtained pancreas at autopsy from 45 humans, divided into four groups: lean (BMI <25 kg/m
2
); obese (BMI >27 kg/m
2
); non-diabetic; and with type 2 diabetes. Pancreases were evaluated after immunostaining for the duct cell marker cytokeratin and Ki67 for replication.
Results
We show for the first time that both obesity and type 2 diabetes in humans are associated with increased pancreatic ductal replication. Specifically, we report that (1) replication of pancreatic duct cells is increased tenfold by obesity, and (2) lean subjects with type 2 diabetes demonstrate a fourfold increase in replication of pancreatic duct cells compared with their lean non-diabetic controls.
Conclusions/interpretation
Pancreatic duct cell replication is increased in humans in response to both obesity and type 2 diabetes, potentially providing a mechanism for the increased risk of pancreatitis and pancreatic cancer in those with obesity and/or type 2 diabetes.
To investigate the efficacy of IA CS (IAC) therapy in single and multiple joints in children with JIA and to seek for predictors of synovitis flare.
The clinical charts of patients who received their ...first IAC injection between January 2002 and December 2008 were reviewed. The CS used was triamcinolone hexacetonide for large joints and methylprednisolone acetate for small or difficult to access joints. Patients were stratified as follows: one joint injected; two joints injected; and three or more joints injected. Predictors included sex, age at disease onset, JIA category, age and disease duration, ANA status, iridocyclitis, general anaesthesia, number and type of injected joints, acute-phase reactants and concomitant MTX therapy.
The cumulative probability of survival without synovitis flare for patients injected in one, two, or three or more joints was 70, 45 and 44%, respectively, at 1 year; 61, 32 and 30%, respectively, at 2 years; and 37, 22 and 19%, respectively, at 3 years. On Cox regression analysis, positive CRP, negative ANA and injection in the ankle were the strongest predictors for synovitis flare. The only significant side effect was skin hypopigmentation or s.c. atrophy, which occurred in <2% of patients.
IAC therapy-induced sustained remission of synovitis in a substantial proportion of patients injected either in single or multiple joints, with a good safety profile. The risk of synovitis flare was higher in patients who had positive CRP, negative ANA and were injected in the ankle.
Summary
Background
Severe clotting deficiencies are associated with enhanced in vitro fibrinolysis due to insufficient thrombin activatable fibrinolysis inhibitor (TAFI) activation. Because oral ...anticoagulant therapy (OAT) with warfarin causes a partial deficiency of vitamin K‐dependent factors, its effect on clot lysability remains unclear.
Objectives
To evaluate plasma and blood fibrinolytic capacity in patients under stable OAT (n = 221) as compared with controls (n = 132).
Methods
Fibrinolysis resistance of plasma (turbidimetry) and blood (thromboelastography) clots was calculated as the lysis time of tissue factor‐induced clots exposed to 30 and 100 ng mL−1 t‐PA, respectively.
Results
Plasma PAI‐1 was similar in the two groups, whereas TAFI was slightly lower in patients. OAT plasma clots lysed faster than controls (P = 0.001). The addition of the TAFIa inhibitor PTCI reduced lysis time by 14% in OAT and 34% in controls, and the difference between the groups disappeared. Similar data were obtained with blood clots. Thrombin and TAFIa generation in OAT plasma amounted to roughly 50% of controls, supporting a reduced thrombin‐dependent TAFI activation. Clot resistance of OAT plasma was normalized by Ba‐citrate plasma eluate or prothrombin but not by BaSO4 serum eluate, rFVIIa or FX. Surprisingly, circulating levels of TAFIa and its inactive derivative TAFIai were higher in warfarin patients (P < 0.0001) and correlated with plasmin‐antiplasmin (P = 0.0001) but not with prothrombin F1 + 2.
Conclusions
OAT enhances both plasma and blood fibrinolysis by reducing thrombin‐dependent TAFI activation, a phenomenon largely determined by low prothrombin levels. At variance with in vitro data, ‘basal’ in vivo TAFIa/ai levels seem related to plasmin rather than thrombin generation.
We investigated whether there was evidence of attempted beta cell regeneration in the pancreas obtained from a patient with recent-onset type 1 diabetes, and if so by what mechanism this occurred.
We ...examined pancreas tissue from a lean 89-year-old patient (BMI 18.0 kg/m(2)) with recent-onset type 1 diabetes who had had a distal pancreatectomy to remove a low-grade pancreatic intraepithelial neoplasia.
In the tumour-free tissue, the fractional beta cell area was 0.54+/-0.2% of pancreas area (about one-third of that in non-diabetic humans). CD3-positive T lymphocytes and macrophages had infiltrated the majority of the islets. Subclassification of the T cell population revealed a predominance of CD8-positive cells over CD4-positive cells. Beta cell apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling TUNEL staining) was greatly increased, consistent with ongoing immune-mediated beta cell destruction. There was also a marked increase (more than approximately 100-fold) in the frequency of beta cell replication (0.69+/-0.15% Ki67-positive beta cells) in all blocks examined.
The present report provides direct evidence of attempted beta cell regeneration through the mechanism of beta cell replication in a case of newly diagnosed type 1 diabetes, and affirms that beta cell apoptosis is an important mechanism for beta cell loss in type 1 diabetes.
Aims/hypothesis Type 1 diabetes is characterised by a deficit in beta cell mass thought to be due to immune-mediated increased beta cell apoptosis. Beta cell turnover has not been examined in the ...context of new-onset type 1 diabetes with diabetic ketoacidosis. Methods Samples of pancreas were obtained at autopsy from nine patients, aged 12 to 38 years (mean 24.3±3.4 years), who had had type 1 diabetes for less than 3 years before death due to diabetic ketoacidosis. Samples of pancreas obtained at autopsy from nine non-diabetic cases aged 11.5 to 38 years (mean 24.2±3.4 years) were used as control. Fractional beta cell area (insulin staining), beta cell replication (insulin and Ki67 staining) and beta cell apoptosis (insulin and TUNEL staining) were measured. Results In pancreas obtained at autopsy from recent-onset type 1 diabetes patients who had died of diabetic ketoacidosis, the beta cell deficit varied from 70 to 99% (mean 90%). The pattern of beta cell loss was lobular, with almost all beta cells absent in most pancreatic lobules; islets in lobules not devoid of beta cells had reduced or a near-normal complement of beta cells. Beta cell apoptosis was increased in recent-onset type 1 diabetes, but to a surprisingly modest degree given the marked hyperglycaemia (30 mmol/l), acidosis and presumably high NEFA. Beta cell replication, scattered pancreatic beta cells and beta cells in exocrine ducts were not increased in recent-onset type 1 diabetes. Conclusions/interpretation These findings do not support the notion of active beta cell regeneration by replication in new-onset type 1 diabetes under conditions of diabetic ketoacidosis. The gluco-lipotoxicity reported in isolated human islets may be less evident in vivo.
Introduction
This study aimed to illustrate the validity of the treatment with vertebroplasty (VP) in patients with aggressive or symptomatic vertebral hemangioma (VH) with or without epidural ...extension.
Methods
From January 2003 to December 2007, 24 consecutive patients have been treated with VP, for a total of 36 vertebral bodies affected by VH: two cervical, ten dorsal, 24 lumbar. All the patients complained of a pain syndrome resistant to continuous medical medication; four of 24 patients also presented aggressive magnetic resonance features of the vertebral lesion and two patients showed also epidural extension. A unipedicular approach has been performed in 16 patients; a bipedicular approach has been performed in six, while for the cervical spine an anterior–lateral approach with manual dislocation of the carotid axis has always been performed. Bone biopsy was never done. All procedures have been carried out with local anesthesia, except for the treatment of the cervical hemangiomas which has always been performed under general anesthesia. Four vertebral bodies in the same session have been treated in one case.
Results
Results have been evaluated with the visual analog scale and the Oswestry Disability Index methods. In all the patients, in the following 24–72 h, a successful outcome has been observed with a complete resolution of pain symptom. Extravertebral vascular or discal cement leakage has been observed in four patients, without any onset of clinical radicular syndrome due to epidural diffusion. Clinical and radiological follow-up until 4 years has been performed in 12 patients and it showed stability of the treatment and absence of pain.
Conclusions
Percutaneous treatment with VP for aggressive and symptomatic vertebral hemangiomas even with epidural extension is a valuable, mini-invasive, and quick method that allows a complete and enduring resolution of the painful vertebral symptoms without findings of fracture of a vertebral body adjacent or distant to the one treated.
Type 1 and type 2 diabetes are characterised by a beta cell deficit. Islet hyperplasia has been described in patients with Zollinger-Ellison syndrome secondary to gastrin-producing tumours ...(gastrinomas), and gastrin therapy has increased beta cell mass in rodents and human islets in vitro. In the present studies we addressed the following questions: (1) In pancreas specimens from gastrinoma cases, is the fractional beta cell area increased? (2) If so, is this restricted to tumour-adjacent islets or also present in tumour-distant islets? (3) Is new beta cell formation (beta cell replication and islet neogenesis) increased and beta cell apoptosis decreased in pancreas specimens from gastrinoma cases?
Pancreas was obtained at surgery from four patients with Zollinger-Ellison syndrome caused by pancreatic gastrinomas and 15 control subjects at autopsy.
Islet fractional beta cell area (p<0.001), islet size (p<0.001) and beta cell replication (Ki67 staining) (p<0.05) were increased in islets adjacent to the tumours, but not in tumour-distant pancreas, compared with control subjects. We did not observe any differences in beta cell apoptosis or in the number of insulin-positive cells in ducts either adjacent to or distant from the tumour.
One or more factors released by human gastrinomas increase beta cell replication in islets immediately adjacent to the tumour, but not in tumour-distant islets. While these findings demonstrate that adult human beta cells can be driven into the cell cycle, they caution against the therapeutic usefulness of gastrin, since islets located >1 cm away from the gastrinomas did not exhibit changes in beta cell turnover, despite markedly elevated systemic gastrin levels sufficient to cause severe gastrointestinal symptoms.
Aims/hypothesis We sought to establish the relationship between fasting plasma glucose concentrations and pancreatic fractional beta cell area in adult cynomolgus monkeys (Macaca fascicularis). ...Methods Fasting plasma glucose and pancreatic fractional beta cell area were measured in 18 control and 17 streptozotocin-treated adult primates (17.0 ± 1.2 vs 15.4 ± 1.2 years old). Results Fasting plasma glucose was increased (12.0 ± 2.0 vs 3.4 ± 0.1 mmol/l, p < 0.01) and fractional beta cell area was decreased (0.62 ± 0.13% vs 2.49 ± 0.35%, p < 0.01) in streptozotocin-treated monkeys. The relationship between fasting plasma glucose and pancreatic fractional beta cell area was described by a wide range of beta cell areas in controls. In streptozotocin-treated monkeys there was an inflection of fasting blood glucose at ∼50% of the mean beta cell area in controls with a steep increase in blood glucose for each further decrement in beta cell area. Conclusions/interpretation In adult non-human primates a decrement in fractional beta cell area of ∼50% or more leads to loss of glycaemic control.
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