Diabetes and CoViD-19: Experience from the frontline of Internal Medicine wards in Italy.

Available data suggest that the issue of CoViD-19 is particularly critical in patients with diabetes. In Italy, Internal Medicine (IM) wards have played a pivotal role in contrasting the spread of SARS-Cov2. During this pandemic, FADOI submitted a brief questionnaire to a group of its members acting as Head of IM units. Considering 38 units, 58% of beds dedicated to CoViD patients in CoViD Hospitals were in charge of IM, and globally cared for 6650 patients during a six-week period. Of these patients, 1264 (19%) had diabetes. Mortality rate in CoViD patients with or without diabetes were 20.5% and 14%, respectively (p < 0.001). Our survey seems to confirm that diabetes is a major comorbidity of CoViD-19, but it does not support an increased incidence of CoViD-19 infection in people with diabetes, if compared with the figures of patients with diabetes and hospitalized before the outbreak. On the other side, patients with diabetes appeared at a significantly increased risk of worse outcome. This finding underlines the importance of paying special attention to this patient population and its management.

Hospitalization and mortality for acute exacerbation of chronic obstructive pulmonary disease (COPD): an Italian population-based study.

OBJECTIVE: Patients with acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD) have a significant mortality and morbidity. Previous studies have identified a number of independent prognostic factors. However, information on hospital admission databases is limited and data regarding short-term prognosis of these patients in Italian hospitals are lacking. Thus, we performed an epidemiological study on hospital admission for COPD acute exacerbation in Italy. PATIENTS AND METHODS: Patients were identified using clinical Modification (ICD-9-CM) codes. Information was collected on baseline characteristics, vital status at discharge, duration of hospitalization, and up to five secondary discharge diagnoses. Comorbidity was evaluated using the Charlson comorbidity index (CCI). RESULTS: During the observation period (2013-2014), 170,684 patients with COPD acute exacerbation were hospitalized. Mean length of hospitalization (LOH) was 9.95±8.69 days and mean in-hospital mortality was 5.30%. These data correspond to the 4.1% of all hospitalizations and to the 2.8% of all the days of hospitalization in Italy during the study period. In-hospital mortality and LOH varied among different regions (from 3.13 to 7.59% and from 8.22 to 11.28 days respectively). Old age, male gender, low discharge volume, previous hospitalization for COPD exacerbation and CCI resulted as significantly associated with higher in-hospital mortality. CONCLUSIONS: Hospitalization for COPD exacerbation is extremely frequent even in contemporary Italian population. COPD exacerbation is clinically demanding with a not negligible short-term mortality rate and a mean LOH approaching 10 days. These latter findings were quite variable in different regions but should be further analyzed to set up appropriate health-care policies on COPD patients.

Ultrasound elastography is useful to distinguish acute and chronic deep vein thrombosis.

Essentials Ultrasound elastography uses tissue deformation to assess the relative quantification of its elasticity. Compression and duplex ultrasonography may be unable to correctly determine the thrombus age. Ultrasound elastography may be useful to distinguish between acute and chronic deep vein thrombosis. The exact determination of the thrombus age could have both therapeutic and prognostic implications. BACKGROUND: Background Ultrasound elastography (UE) imaging is a novel sonographic technique that is commonly employed for relative quantification of tissue elasticity. Its applicability to venous thromboembolic events has not yet been fully established; in particular, it is unclear whether this technique may be useful in determining the age of deep vein thrombosis (DVT). Thus, the aim of this study was to assess the role of UE in distinguishing acute from chronic DVT. Methods Consecutive patients with a first unprovoked acute and chronic (3 months old) DVT of the lower limbs were analyzed. Patients with recurrent DVT or with a suspected recurrence were excluded. The mean elasticity index (EI) values of acute and chronic popliteal and femoral vein thrombosis were compared. The accuracy of the EI in distinguishing acute from chronic DVT was also assessed by measuring the sensitivity, specificity, positive and negative predictive values, and likelihood ratios. Results One-hundred and forty-nine patients (mean age 63.9 years, standard deviation 13.6; 73 males) with acute and chronic DVT were included. The mean EI of acute femoral DVT was higher than that of chronic femoral DVT (5.09 versus 2.46), and the mean EI of acute popliteal DVT was higher than that of chronic popliteal DVT (4.96 versus 2.48). An EI value of > 4 resulted in a sensitivity of 98.9% (95% confidence interval [CI] 93.3-99.9), a specificity of 99.1% (95% CI 94.8-99.9), a positive predictive value of 91.1% (95% CI 77.9-97.1), a negative predictive value of 98.6% (95% CI 91.3-99.9), a positive likelihood ratio of 13.23 (95% CI 93-653) and a negative likelihood ratio of 0.001 (95% CI 0.008-0.05) for acute DVT. Conclusions UE appears to be a promising technique for distinguishing between acute and chronic DVT. Larger prospective studies are warranted to confirm our preliminary findings.

Residual vein obstruction in patients diagnosed with acute isolated distal deep vein thrombosis associated with active cancer.

After acute proximal deep vein thrombosis (DVT) the thrombotic mass decreases, especially during the first months of anticoagulation. The persistence of residual vein obstruction (RVO) may predict future recurrence in patients with cancer-associated DVT. We aimed to evaluate the proportion of patients with RVO after an episode of cancer associated isolated distal DVT (IDDVT), to identify variables associated with RVO, and to provide initial evidence of its association with recurrent VTE. We performed a post-hoc analysis of a multicenter cohort study of patients with isolated cancer-associated acute IDDVT. We included patients who underwent a control ultrasonography at the end of the anticoagulant treatment between day 30 and day 365 after index IDDVT, given that no recurrent VTE had already occurred on anticoagulant treatment. A total of 153 patients had ultrasonographic follow-up after a median of 92 days from index IDDVT: 45.8% had RVO and 54.2% exhibited complete recanalization. Female sex, Body Mass Index > 30 Kg/m2 and involvement of axial calf veins showed the strongest association with RVO. The risk of recurrence was twofold higher in patients with (versus without) RVO. RVO persisted in approximately half of patients with an episode of cancer-associated IDDVT at anticoagulant discontinuation. Patients with RVO appeared to be at a higher risk for recurrent events.

Clinical course of patients with symptomatic isolated superficial vein thrombosis: the ICARO follow-up study.

Essentials Late sequelae of isolated superficial vein thrombosis (iSVT) have rarely been investigated. We studied 411 consecutive outpatients with acute iSVT with a median follow-up of three years. Male sex and cancer are risk factors for future deep vein thrombosis or pulmonary embolism. Patients without cancer appear to be at a negligible risk for death. SUMMARY: Background Studies of long-term thromboembolic complications and death following acute isolated superficial vein thrombosis (iSVT) of the lower extremities are scarce. Objectives To investigate the course of iSVT in the setting of an observational multicenter study. Methods We collected longitudinal data of 411 consecutive outpatients with acute, symptomatic, objectively diagnosed iSVT who were previously included in the cross-sectional ICARO study. Four patients followed for < 30 days and 79 with concomitant deep vein thrombosis (DVT) or pulmonary embolism (PE) were excluded from the present analysis. The primary outcome was symptomatic DVT or PE. The safety outcomes were major bleeding and all-cause death. Results The median follow-up time was 1026 days (interquartile range 610-1796). Symptomatic DVT/PE occurred in 52 (12.9%) patients, giving annualized rates of 1.3% (95% confidence interval [CI] 0.3-3.9%) on anticoagulant treatment and 4.4% (95% CI 3.2-5.8%) off anticoagulant treatment. Male sex (adjusted hazard ratio [HR] 2.03 [95% CI 1.16-3.54]) and active solid cancer (adjusted HR 3.14 [95% CI 1.11-8.93]) were associated with future DVT/PE, whereas prior DVT/PE failed to show significance, most likely because of bias resulting from prolonged anticoagulant treatment. Three major bleeding events occurred on treatment, giving an annualized rate of 1.4% (95 CI 0.3-4.0%). Death was recorded in 16 patients (annualized rate: 1.1% [95% CI 0.6-1.7%]), and was attributable to cancer (n = 8), PE (n = 1), cardiovascular events (n = 3), or other causes (n = 4). Conclusions The long-term risk of DVT/PE after anticoagulant discontinuation for acute iSVT is clinically relevant, especially in males and in the presence of active cancer. The risk of death appears to be negligible in patients without cancer.

Clinical course of isolated distal deep vein thrombosis in patients with active cancer: a multicenter cohort study.

Essentials Isolated distal deep vein thrombosis (IDDVT) is frequently associated with cancer. No study has specifically evaluated the long-term clinical course of cancer-associated IDDVT. Patients with cancer-associated IDDVT are at very high risk of symptomatic recurrence and death. We observed low rates of major bleeding during anticoagulation. SUMMARY: Background Although isolated distal deep vein thrombosis (IDDVT) is frequently associated with cancer, no study has specifically evaluated the long-term clinical course of IDDVT in this setting. Aim To provide data on the rate of recurrent venous thromboembolism (VTE), major bleeding events and death in IDDVT patients with active cancer. Patients and Methods Consecutive patients with active cancer and an objective IDDVT diagnosis (January 2011 to September 2014) were included from our files. We collected information on baseline characteristics, IDDVT location and extension, VTE risk factors, and type and duration of anticoagulant treatment. Results A total of 308 patients (mean age 66.2 [standard deviation (SD), 13.2 years]; 57.1% female) with symptomatic IDDVT and a solid (n = 261) or hematologic (n = 47) cancer were included at 13 centers. Cancer was metastatic in 148 (48.1%) patients. All but three (99.0%) patients received anticoagulant therapy, which consisted of low-molecular-weight heparin in 288 (93.5%) patients. Vitamin K antagonists were used for the long-term treatment in 46 (14.9%) patients, whereas all others continued the initial parenteral agent for a mean treatment duration of 4.2 months (SD, 4.6 months). During a total follow-up of 355.8 patient-years (mean, 13.9 months), there were 47 recurrent objectively diagnosed VTEs for an incidence rate of 13.2 events per 100 patient-years. During anticoagulant treatment, the annual incidence of major bleeding was 2.0 per 100 patient-years. Conclusions Cancer patients with IDDVT have a high risk of VTE recurrence. Additional studies are warranted to investigate the optimal intensity and duration of anticoagulant treatment for these patients.

Clinical management and outcome of major bleeding in patients on treatment with vitamin K antagonists.

BACKGROUND: The optimal management of major bleeding associated with vitamin K antagonists remains unclear. OBJECTIVES: The aim of the study was to assess the determinants of outcome of vitamin K antagonists-associated major bleeding and the outcome of bleeding in relation with the therapeutic management. METHODS: Patients hospitalized for major bleeding while on vitamin K antagonists were included in a prospective, cohort study. Major bleeding was defined according to the criteria of the International Society of Thrombosis Haemostasis. The primary study outcome was death at 30days from major bleeding. RESULTS: 544 patients were included in this study, of which 282 with intracranial hemorrhage. Prothrombin complex concentrates were used in 51% and in 23% of patients with intracranial hemorrhage or non-intracranial major bleeding, respectively (p<0.001); fresh frozen plasma was used in 7% and in 17% of patients with intracranial hemorrhage or non-intracranial major bleeding (p<0.001). Death at 30days occurred in 100 patients (18%), 72 patients with intracranial hemorrhage and 28 patients with non-intracranial major bleeding. Age over 85years, low Glasgow Coma Scale score and shock were independent predictors of death at 30days. Invasive procedures were associated with decreased risk of death. CONCLUSIONS: Among the patients hospitalized for major bleeding while on vitamin K antagonists, the risk for death is substantial. The risk for death is associated with the clinical severity of major bleeding as assessed by the GCS score and by the presence of shock more than with the initial localization of major bleeding (ICH vs other sites).

OC-01 - Clinical history of cancer patients with isolated distal deep vein thrombosis: a multicenter cohort study.

INTRODUCTION: Isolated distal deep vein thrombosis (IDDVT) accounts for one-fourth to one-half of all deep vein thrombosis (DVT) of the leg. Patients with IDDVT are frequently treated for a shorter period of time compared to patients with proximal DVT and/or pulmonary embolism (PE) due to a perceived lower risk of recurrence. About 10-20% of patients with venous thromboembolic events (VTEs) have concomitant cancer. Guidelines recommend long-term anticoagulant treatment in this group of patients due to their high risk of VTE recurrence. Unfortunately, information on the clinical history of IDDVT patients is limited and, to date, no study has evaluated the long-term risk of VTE recurrence in IDDVT patients with cancer. AIM: To provide information on the clinical history of IDDVT patients with active cancer. MATERIALS AND METHODS: A multicenter, cohort study including active-cancer patients with an objective diagnosis of IDDVT (between January 2011 and September 2014) was conducted. Information on baseline characteristics, thrombosis location and extension, concomitant risk factors, type and duration of treatment was collected. All patients were followed for a minimum of 12 months and up to 24 months. During follow-up, VTE recurrence, major bleeding episodes and death were registered. Potential risk factors for VTE recurrence were evaluated. RESULTS: 308 patients (mean age 66.2±13.2 years, female 57.1%) in 13 centers were included, Table 1; 261 patients had solid cancer and 47 patients hematologic cancer. At the time of IDDVT diagnosis, the disease was metastatic in 148 patients (48.1%); 99.0% of patients received anticoagulant treatment: 288 patients (93.5%) were initially treated with low molecular weight heparin, 15 with fondaparinux (5.2%) and 1 with unfractionated heparin; vitamin K antagonists were used in 46 patients (14.9%) only. Total follow-up was 389 patient-years, mean follow-up 15.2 months. Mean duration of treatment was 4.2 months. During the study period there were 47 episodes of VTE recurrence (36 proximal DVT or PE) for a incidence rate of 13.2 events per 100 patient-years; 7 patients had major bleeding (2.3%) and 137 died (44.5%). At multivariate analysis, previous VTE was associated with an increased risk of recurrence (OR 2.10; 95% 1.06, 4.14), whereas patients with gastrointestinal cancer had a lower risk of recurrence (OR 0.26; 95% CI 0.08, 0.86). CONCLUSIONS: Cancer patients with IDDVT have a high risk of VTE recurrence. Other studies are warranted to address the adequate management of these patients.

A clinical score to rule out the concomitant presence of deep vein thrombosis in patients presenting with superficial vein thrombosis: The ICARO study.

BACKGROUND: Superficial vein thrombosis (SVT) is commonly encountered in clinical practice. Recent studies have suggested that the concomitant presence of deep vein thrombosis (DVT) or pulmonary embolism (PE) at the time of SVT diagnosis is not uncommon, thus increasing the interest on this disease. Whether this coexistence is predicted by specific risk factors remains unknown. AIM OF THE STUDY: To evaluate potential risk factors for DVT coexistence in patients presenting with acute objectively diagnosed SVT of the lower limbs and to develop a simple score entirely based on clinical variables to define the pre-test probability of DVT in these patients. METHODS: A multicenter, retrospective cohort study on SVT patients was conducted. Information was collected on clinical signs and on risk factors for venous thrombosis. RESULTS: 494 patients (mean age 56.3 ± 17.9 years, 64.2% women) were included. Concomitant DVT was found in 16.0% of patients. After multivariate analysis, we identified 5 independent variables that were used to develop the ICARO score: active malignancy (1.5 points), limb edema (1.5 points), rope-like sign (-1 point), age ≥ 50 years (1 point), unprovoked SVT (-1 point). The prevalence of concomitant DVT was 1.1% in the low-probability category (< 0 points), 12.0% in the intermediate-probability category (0 to 1 points), and 32.3% in the high probability category (≥ 1.5 points). CONCLUSIONS: The concomitant presence of major DVT is not negligible in patients with SVT. Our prediction score entirely based on simple clinical variables may be useful in assessing the risk of concomitant DVT in these patients.

Poor predictive value of contemporary bleeding risk scores during long-term treatment of venous thromboembolism. A multicentre retrospective cohort study.

Bleeding is a common and feared complication of oral anticoagulant therapy. Several prediction models have been recently developed, but there is a lack of evidence in patients with venous thromboembolism (VTE). The aim of this study was to validate currently available bleeding risk scores during long-term oral anticoagulation for VTE. We retrospectively included adult patients on vitamin K antagonists for VTE secondary prevention, followed by five Italian Anticoagulation Clinics (Cuneo, Livorno, Mantova, Napoli, Varese), between January 2010 and August 2012. All bleeding events were classified as major bleeding (MB) or clinically-relevant-non-major-bleeding (CRNMB). A total of 681 patients were included (median age 63 years; 52.0% female). During a mean follow-up of 8.82 (± 3.59) months, 50 bleeding events occurred (13 MB and 37 CRNMB), for an overall bleeding incidence of 9.99/100 patient-years. The rate of bleeding was higher in the first three months of treatment (15.86/100 patient-years) than afterwards (7.13/100 patient-years). The HAS-BLED showed the best predictive value for bleeding complications during the first three months of treatment (area under the curve [AUC] 0.68, 95% confidence interval [CI] 0.59-0.78), while only the ACCP score showed a modest predictive value after the initial three months (AUC 0.61, 95%CI 0.51-0.72). These two scores had also the highest sensitivity and the highest negative predictive value. None of the scores predicted MB better than chance. Currently available bleeding risk scores had only a modest predictive value for patients with VTE. Future studies should aim at the creation of a new prediction rule, in order to better define the risk of bleeding of VTE patients.

Early stratification of patients with chest pain and suspected acute coronary syndrome in the Emergency Department.

AIM: The aim of this study was to investigate the accuracy of a critical pathway in the early stratification and management of patients with chest pain and suspected acute coronary syndrome (ACS) in the Emergency Department (ED). METHODS: An observational study was performed enrolling all patients with non-traumatic chest pain and suspected ACS who presented during a one-year period in the ED, where a critical pathway with five-level risk stratification, based on risk factors, characteristics of pain and ECG, was implemented. Patients were prospectively evaluated for rates of death, unstable angina, myocardial infarction or revascularization procedure occurring during admission or in the 30 days following discharge from the ED. Receiver-Operating Characteristics (ROC) curve was used to measure the accuracy of the stratification method. RESULTS: Overall, 1813 patients were enrolled: 475 patients (26.1%, 95% CI: 24.0-28.1 ) were admitted and 1338 (73.8%, 95% CI: 71.7-75.8) were discharged. Main outcomes occurred in 233 (49.9%, 95% CI: 47.5-52.2) of patients admitted and in 6 (0.4%, 95% CI: 0.06-0.7) of those discharged. The risk stratification system showed a good accuracy with an AUC-ROC curve of 0.90 (95% CI: 0.88-0.93). A total of 1541 (85%) patients were managed according to critical pathway. Adverse events were significantly fewer in patients discharged according to pathway criteria than in those who were not (0.27% vs. 1.37%, difference: 1.1% CI 95%: 0.06-2.1), without significant increase of inappropriate admissions. CONCLUSION: A critical pathway, based on clinical and ECG features, is a safe and accurate tool to stratify and manage the patients with non-traumatic chest pain and suspected ACS in the ED.

Cutaneous myiasis in a geriatric patient.

Cutaneous myiasis in humans involving fly species endemic in Italy are uncommon and are not often present in the literature. In the present article we describe the case of cutaneous myiasis in a woman brought to the Emergency Department (ED) of the S. Croce e Carle General Hospital in Cuneo, northwest Italy. The patient was in precarious hygienic condition, and was suffering from localized ulcerated foot ulcers with significant inflammation extending up to the knee. Fly larvae, subsequently identified as Lucilia sericata (Meigen, 1826), were found in the lesions. The patient was admitted to the Department of Internal Medicine where she was treated with antibiotics and the lesions were medicated, resulting in full recovery.

Pasteurella multocida infection in a cirrhotic patient: case report, microbiological aspects and a review of literature.

Pasteurellosis is a zoonosis often caused by cat or dog bites or scratches, or by direct exposure to their secretions. Pasteurella multocida is the main pathogen involved in infections through domestic animal bites; generally a local infection characterized by its particular virulence with consequent rapid onset. Serious infection has also been reported in persons affected by comorbidity without domestic animal bite injuries. Here we report the case of a woman with lower limb exudating vesicular skin ulcers affected by liver cirrhosis, bilateral knee arthritis, septicemia with positive blood culture and synovial fluid culture for Pasteurella multocida. The etiology of Pasteurella multocida must be borne in mind in cases of sepsis in immunodeficient individuals, such as the cirrhotic patient, as well as exposure to domestic animals.

Vertebroplasty in the treatment of osteoporosis vertebral fractures: report on 52 cases.

BACKGROUND: Percutaneous vertebroplasty (PV) is largely employed in vertebral body compression fractures (VCF). PURPOSE: To evaluate the efficacy of PV on pain relief and functional status, and its complications rate. MATERIALS AND METHODS: A prospective observational study was conducted by the Division of Internal Medicine of St. Croce and Carle Hospital. INCLUSION CRITERIA: Diagnosis of osteoporosis, intense back pain, unresponsive to conservative treatment, associated with radiological evidence of recent VCF. Pain control and functional improvement were respectively assessed using Visual Analogue Scale (VAS) and Activity of Daily Living scale (ADL) on admission, 24 h after PV and at follow-up. PV complications were detected by an immediate computed tomography (CT) scan on the vertebra treated as well as the vertebrae above and below the treated level(s) and by CT chest scan to exclude pulmonary emboli. A magnetic resonance imaging (MRI) follow-up at 6 or 12 months was performed. RESULTS: Fifty-two (46 with primary osteoporosis) patients were enrolled (mean age 73.18 yr, range 44-92). Median follow-up was 20.4 months (range 6-24). Treated vertebrae were 124. VAS, mean value was 9.05 (range 6-10) before treatment, 5.95 (range 2-8) at 24 h after PV and 4.94 (range 2-9) at follow-up (p<0.001). Before PV, 18 patients (34.6%) were functionally impaired vs 8 patients (15.3%) at follow-up (p<0.003). Control MRI evidenced 9 (17.3%) new VCF adjacent and 13 (25%) non-adjacent to treated vertebras. There was one case of discitis. Seven cases (13%) of cement leakage in para-vertebral space were observed. CONCLUSION: PV is safe and effective in immediate pain reduction and functional improvement and at a median term follow-up.

Worsening of hypertension in a pregnant woman with renal arteriovenous malformation: a successful superselective embolization after delivery.

A 30-year-old female presented with uncontrolled hypertension due to arteriovenous malformation in the upper third of the right kidney, which worsened during pregnancy. The arteriovenous malformation was detected by color-coded Doppler sonography, confirmed by angiography, and the fistula was sealed by superselective arterial embolization with metallic coils. Superselective embolization is the most effective and safe treatment for this rare and complex pathology.

A study of capillary pericyte viability on extracellular matrix produced by endothelial cells in high glucose.

AIMS/HYPOTHESIS: Thickening of the basement membrane and selective loss of pericytes occur early in diabetic retinopathy. As we showed previously that pericyte adhesion is impaired on extracellular matrix produced by endothelial cells in high hexose concentrations, we aimed to verify if altered adhesion could influence pericyte viability and replication. METHODS: Conditioned extracellular matrices were obtained by growing human umbilical vein endothelial cells in media containing 28 mmol/l D-glucose, with or without the inhibitors of protein glycation thiamine or aminoguanidine, and D-galactose or L-glucose up to 28 mmol/l. Having removed the endothelium, bovine retinal pericytes were grown on these matrices and, in separate experiments, on laminin, fibronectin or type IV collagen. Pericyte viability and replication were measured by cell counts and DNA synthesis after 7 days, cell cycle traversal after 2 days and apoptosis after 18 h, 2 days and 7 days. RESULTS: Pericyte counts and DNA synthesis were reduced on matrices produced in high D-glucose and D-galactose, whilst matrix obtained in L-glucose reduced DNA synthesis but not counts. Both thiamine and aminoguanidine corrected reduced pericyte viability when added to high D-glucose. Cell cycle and apoptosis were not affected by growing pericytes on different conditioned matrices. Laminin, fibronectin and type IV collagen did not modify pericyte replication. CONCLUSIONS/INTERPRETATIONS: Reduced pericyte counts could depend on impaired initial adhesion to the extracellular matrix produced by endothelium in high hexose concentrations, rather than impaired replication or viability. Altered cell-matrix interactions might facilitate pericyte dropout in diabetic retinopathy, independently of the effects of high glucose on pericyte replication.

Effects of protein kinase C inhibition and activation on proliferation and apoptosis of bovine retinal pericytes.

AIMS/HYPOTHESIS: Drop-out of capillary pericytes occurs early and selectively in diabetic retinopathy. High glucose concentrations decrease replication and increase apoptosis of cultured pericytes. Since glucose activates protein kinase C, we investigated the effects of modulating this intracellular mediator on replication, cell cycle and apoptosis of cultured bovine retinal pericytes. METHODS: Pericytes cultured in 5.6 or 28 mmol/l glucose were exposed to a protein kinase C activator (phorbol 12-myristate 13-acetate) and/or a selective inhibitor of its beta2 isoform (LY379196). Cells were counted after 7 days. Proliferation by the tetrazolium to formazan assay and DNA synthesis by 5-bromo-2'-deoxyuridine incorporation were measured at day 4. Cell cycle by flow cytometry and apoptosis by ELISA were assessed at day 2. RESULTS: High glucose reduced pericyte replication and increased apoptosis. Protein kinase C activation increased proliferation, while inhibition of its beta2 isoform decreased it. Cell cycle was accelerated by protein kinase C activation and delayed by inhibition. Apoptosis was enhanced by protein kinase C inhibition and reduced by activation. CONCLUSIONS/INTERPRETATION: Protein kinase C inhibition amplifies the anti-proliferative and pro-apoptotic effects of high glucose on cultured pericytes, whereas stimulation reduces apoptosis and promotes proliferation both in physiological glucose and high glucose. Protein kinase C inhibition, proposed for the treatment of diabetic macular edema and proliferative retinopathy, might accelerate pericyte dropout in earlier stages when these cells are still present in retinal capillaries.

Pericyte adhesion is impaired on extracellular matrix produced by endothelial cells in high hexose concentrations.

AIMS/HYPOTHESIS: Thickening of the basement membrane and selective loss of pericytes are early events in diabetic retinopathy. We aimed at checking whether pericyte interaction with extracellular matrix produced by endothelial cells is influenced by the hexose concentrations in which endothelial cells are cultured. METHODS: Conditioned extracellular matrixes were obtained by growing human umbilical vein endothelial cells in media containing 28 mmol/l hexoses (D-glucose, D-galactose, L-glucose), which undergo different intracellular processing, before and after adding the inhibitors of protein glycation thiamine or aminoguanidine. Having removed the endothelium, bovine retinal pericytes were grown on such matrixes and, in separate experiments, on laminin, fibronectin or type IV collagen. Pericyte adhesion was determined by cell counts 18 h after seeding. RESULTS: Reduced adhesion was observed on matrixes produced in high D-glucose, high D-galactose and high L-glucose. Both thiamine and aminoguanidine restored impaired pericyte adhesion when added to high D-glucose and high D-galactose, but not L-glucose. Laminin, fibronectin and type IV collagen did not consistently modify pericyte adhesion. CONCLUSIONS/INTERPRETATIONS: Pericyte adhesion is impaired on extracellular matrix produced by endothelium in high hexose concentrations. This could result from excess protein glycation, corrected by aminoguanidine and thiamine, rather than altered glycoprotein composition.

Failure of angiotensin II and insulin to stimulate transforming growth factor-beta1. Release from cultured bovine retinal pericytes.

BACKGROUND: Activation of the renin-angiotensin system (RAS) may induce cardiovascular and renal fibrosis in hypertension and diabetes. This fibrogenic effect is mainly mediated by Transforming Growth Factor-B1 (TGF-B1), a multifunctional citokyne released by endothelial, vascular smooth muscle and renal mesangial cells, that is able to increase extracellular matrix deposition. Retinal capillary pericytes have functions similar to those of mesangial cells, including ability to synthesize and release TGF-B1 and produce extracellular matrix. An intraocular RAS was described in the human eye and may produce effects similar to those observed in the heart and kidney, which could be mediated by TGF-B1. In particular, TGF-B1 might be involved in thickening of the capillary basement membrane in diabetic microangiopathy. We therefore aimed at evaluating the possible effects of Angiotensin-II on TGF-B1 secretion by cultured retinal pericytes (BRP). METHODS: BRP cultures were incubated with Angiotensin-II or insulin (known to play a permissive effect on TGF-B1 release from mesangial cells) or Angiotensin-II + insulin at final concentrations of 10-10, 10-8, 10-6, 10-4 mol/L. RESULTS: Baseline TGF-B1 concentrations in the supernatants of pericyte cultures were 6 139 +/- 1 919 pg/mL/106 cells; no changes of TGF-B1 concentrations resulted from adding increasing amounts of Ang II, insulin or both. CONCLUSIONS: Though confirming that cultured bovine retinal pericytes spontaneously release TGF-B1, Angiotensin-II did not produce any stimulatory effects of in our experimental system