The activity of N-acetyl-beta-D-glucosaminidase and tumor necrosis factor-alpha at early stage of diabetic retinopathy development in type 1 diabetes mellitus children

Stimulating the Melanocortin System in Uveitis and Diabetes Preserves the Structure and Anti-Inflammatory Activity of the Retina

The endogenous neuropeptide α-Melanocyte Stimulating Hormone (α-MSH) is a potent suppressor of inflammation and has an essential role in maintaining the normal anti-inflammatory microenvironment of the retina. While the therapeutic use of α-MSH peptide in uveitis and diabetic retinopathy models has been demonstrated, its short half-life and instability limit its use as a therapeutic drug. A comparable analog, PL-8331, which has a stronger affinity to melanocortin receptors, longer half-life, and, so far, is functionally identical to α-MSH, has the potential to deliver melanocortin-based therapy. We examined the effects of PL-8331 on two mouse models of retinal disease, Experimental Autoimmune Uveoretinitis (EAU) and Diabetic Retinopathy (DR). PL-8331 therapy applied to mice with EAU suppressed EAU and preserved retinal structures. In diabetic mice, PL-8331 enhanced the survival of retinal cells and suppressed VEGF production in the retina. In addition, retinal pigment epithelial cells (RPE) from PL-8331-treated diabetic mice retained normal anti-inflammatory activity. The results demonstrated that the pan-melanocortin receptor agonist PL-8331 is a potent therapeutic drug to suppress inflammation, prevent retinal degeneration, and preserve the normal anti-inflammatory activity of RPE.

High Glycated Hemoglobin Instead of High Body Mass Index Might Increase the Urine N-Acetyl-β-D-glucosaminidase Con-Centration in Children and Adolescents with Diabetes Mellitus

Children with diabetes, and particularly those with obesity, have poor glycemic control. They are thus at higher risk of early microvascular complications. Renal tubulointerstitial markers are integral to evaluating diabetic nephropathy. Various biomarkers have been proposed, but their role in the obese pediatric population is uncertain. We investigated renal injury markers in children with diabetes, according to obesity, and determined their role as early predictors of diabetic nephropathy. Fifty-three children and adolescents, diagnosed with either type 1 or 2 diabetes mellitus, and 43 control children, aged 7-18 years, were included. Clinical and laboratory characteristics, including six renal injury markers, were compared among subjects according to body mass index and presence of diabetes mellitus. Urine neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, and N-acetyl-β-D-glucosaminidase (NAG) showed significant difference between controls and diabetic children, whereas urine NAG was the only biomarker that was significantly lower either in non-obese or obese controls as compared to diabetic children. Urine NGAL, KIM-1, and NAG showed significant correlations with both HbA1c and urine ACR, whereas only urine NAG was significantly correlated with HbA1c even when groups were subdivided based on the presence of either obesity or diabetes. After adjusting for age, sex, body mass index, duration of known diabetes, and urine albumin-to-creatinine ratio, HbA1c remained a significant risk factor for elevated urine NAG. Urine NAG could be a useful indicator of tubulointerstitial damage in children with diabetes in the pre-albuminuric state. Tighter glycemic control appears to be crucial for avoiding early progression to diabetic nephropathy.

Anti-inflammatory α-Melanocyte-Stimulating Hormone Protects Retina After Ischemia/Reperfusion Injury in Type I Diabetes

Retinal ischemia/reperfusion (I/R) injury is a major cause of vision loss in many ocular diseases. Retinal I/R injury is common in diabetic retinopathy, which as a result of hyperglycemia damages the retina and can cause blindness if left untreated. Inflammation is a major contributing factor in the pathogenesis of I/R injury. α-Melanocyte-stimulating hormone (α-MSH) is an anti-inflammatory peptide hormone that has displayed protective effects against I/R-induced organ damages. Here, we aimed to investigate the protective role of α-MSH on I/R-induced diabetic retinal damage using hyperglycemic C57BL/6J Ins2Akita/+ mice. Experimental I/R injury was induced by blocking the right middle cerebral artery (MCA) for 2 h followed by 2 h or 22 h of reperfusion using the intraluminal method. Since ophthalmic artery originates proximal to the origin of the MCA, the filament also blocked blood supply to the retina. Upon treatment with α-MSH at 1 h after ischemia and 1 h after reperfusion, animals displayed significant improvement in amplitudes of b-wave and oscillatory potentials during electroretinography. α-MSH also prevented I/R-induced histological alterations and inhibited the development of retinal swelling. Loss of retinal ganglion cells as well as oxidative stress were significantly attenuated in the α-MSH-treated retinae. Level of interleukin 10 was significantly increased after α-MSH treatment. Moreover, gene expression of glutamate aspartate transporter 1, monocarboxylate transporter (MCT) 1 and MCT-2 were significantly higher after α-MSH administration. In conclusion, α-MSH mitigates the severity of I/R-induced retinal damage under hyperglycemic condition. These beneficial effects of α-MSH may have important therapeutic implications against retinal I/R injury under hyperglycemic condition.

Mechanism of Propofol-Lidocaine Hydrochloride Nano-Emulsion on Retinal Ganglion Cytopathic Effect in Diabetic Rats

The study drew attention to the influence mechanism of propofol and lidocaine hydrochloride nanoemulsion (NE) in the retinal ganglion cell pathology in diabetic rats. Specifically, the propofollidocaine hydrochloride NE was prepared using the emulsification method. The microscope and laser particle size analyser were used to observe the morphology and particle size of NE, respectively. Also, the viscosity of the NE and the recovery rate of the main ingredient were explored. 45 adult male Wistar rats were randomly divided into control group (PBS control), model group (diabetes model), and test group (diabetes model+propofol-lidocaine hydrochloride NE), with 15 rats in each group. The three groups were compared for the blood glucose, body weight, TNF-α and IL-1β mRNA levels in retinal tissue, and the number and apoptosis rate of ganglion cells. It was found that the average particle size of the NE was 89.76 nm, the maximum absorption wavelength was 280.0 nm, and the viscosity was 106.49 N/m/s. The average recovery rate of propofol in NE was 99.91%, and that of lidocaine hydrochloride was 99.80%. At 12th week after modeling, the blood glucose of the test group was lower versus the model group (P < 0.05); the blood glucose and body weight of rats in the control group were lower than those in the other two groups (P < 0.001). The test group exhibited lower mRNA levels of TNF-α and IL-1β and apoptosis index of retinal ganglion cells versus the model group (P < 0.05). The model group showed a lower number of retinal ganglion cells versus the other two groups (P < 0.05). It was inferred that propofol-lidocaine hydrochloride NE of a small particle size and good syringeability can notably reduce blood glucose, TNF-α and IL-1β mRNA levels, and retinal ganglion cell apoptosis index, and at the same time increase the number of retinal ganglion cells.

Increased vitreal levels of interleukin-10 in diabetic retinopathy: a Meta-analysis

AIM

To conduct a Meta-analysis for the change of interleukin-10 (IL-10) concentration in vitreous samples of patients with diabetic retinopathy (DR).

METHODS

Systemic search for literature was conducted from the databases of PubMed, Web of Science and Cochrane Library by August 2019. Statistical analyses including standard mean difference (SMD) and its 95% confidence interval (CI) were performed by using RevMan 5.3 software.

RESULTS

Totally 194 studies were screened and finally 11 studies were included in the Meta-analysis. The concentration of IL-10 in the DR group was higher than in the control group (P=0.003, SMD: 0.77, 95%CI: 0.25-1.28). Significant heterogeneity was found among all studies (P<0.00001, I ²=92%). The subgroup analysis showed that the concentration of IL-10 increased in vitreous samples from patients with DR compared to the non-DR controls (P=0.004, SMD: 1.44, 95%CI: 0.46-2.42). Moreover, the concentration of IL-10 in samples of proliferative diabetic retinopathy (PDR) patients was significantly higher than that of non-proliferative diabetic retinopathy (NPDR) patients (P=0.01, SMD: 0.61, 95%CI: 0.13-1.08).

CONCLUSION

The vitreal concentration of IL-10 is significantly increased in patients with DR. Further studies are needed to reveal the mechanisms of IL-10 in DR.

Roles of elevated intravitreal IL-1β and IL-10 levels in proliferative diabetic retinopathy

Purpose:

To determine the roles of interleukin (IL)-1β and IL-10 in the vitreous of proliferative diabetic retinopathy (PDR).

Materials and Methods:

Vitreous samples were obtained from 26 eyes of 26 patients with PDR and from eight eyes of eight cases without PDR. The IL-1β and IL-10 concentration in the vitreous was measured by using an enzyme-linked immunosorbent assay (ELISA).

Results:

Levels of IL-1β and IL-10 in vitreous were higher in PDR patients compared with control group. And there was significantly negative correlation between IL-1β and IL-10 in control group (r = −0.795; P = 0.032), whereas there was no significant correlation in PDR group (r = 0.176; P = 0.391).

Conclusion:

Levels of IL-1β and IL-10 were upregulated in vitreous of PDR patients, and these two cytokines play roles in regulating the development and progression of PDR.

Nuclear factor of activated T cells is activated in the endothelium of retinal microvessels in diabetic mice

The pathogenesis of diabetic retinopathy (DR) remains unclear but hyperglycemia is an established risk factor. Endothelial dysfunction and changes in Ca2+ signaling have been shown to precede the onset of DR. We recently demonstrated that high extracellular glucose activates the Ca(2+)/calcineurin-dependent transcription factor NFAT in cerebral arteries and aorta, promoting the expression of inflammatory markers. Here we show, using confocal immunofluorescence, that NFAT is expressed in the endothelium of retinal microvessels and is readily activated by high glucose. This was inhibited by the NFAT blocker A-285222 as well as by the ectonucleotidase apyrase, suggesting a mechanism involving the release of extracellular nucleotides. Acute hyperglycemia induced by an IP-GTT (intraperitoneal glucose tolerance test) resulted in increased NFATc3 nuclear accumulation and NFAT-dependent transcriptional activity in retinal vessels of NFAT-luciferase reporter mice. In both Akita (Ins2(+/-) ) and streptozotocin- (STZ-) induced diabetic mice, NFAT transcriptional activity was elevated in retinal vessels. In vivo inhibition of NFAT with A-285222 decreased the expression of OPN and ICAM-1 mRNA in retinal vessels, prevented a diabetes driven downregulation of anti-inflammatory IL-10 in retina, and abrogated the increased vascular permeability observed in diabetic mice. Results identify NFAT signaling as a putative target for treatment of microvascular complications in diabetes.

Effector and regulatory T cell subsets in diabetes-associated inflammation. Is there a connection with ST2/IL-33 axis? Perspective

Type 1 diabetes (DM1) is a chronic inflammatory disease, which when progresses leads to the development of late vascular complications. The disease involves impairments in regulatory and effector subsets of T lymphocytes, which suppress and maintain inflammatory response, respectively. ST2/IL-33 pathway is involved in T-cell-mediated immune response and might regulate the inflammatory process in several diseases. This review presents the latest research findings regarding effector and regulatory T cell subsets in the context of inflammation accompanying DM1 with particular focus on the ST2/IL-33 network and its possible association with T cell-mediated immunity.

Animal models of diabetic retinopathy: summary and comparison

Diabetic retinopathy (DR) is a microvascular complication associated with chronic exposure to hyperglycemia and is a major cause of blindness worldwide. Although clinical assessment and retinal autopsy of diabetic patients provide information on the features and progression of DR, its underlying pathophysiological mechanism cannot be deduced. In order to have a better understanding of the development of DR at the molecular and cellular levels, a variety of animal models have been developed. They include pharmacological induction of hyperglycemia and spontaneous diabetic rodents as well as models of angiogenesis without diabetes (to compensate for the absence of proliferative DR symptoms). In this review, we summarize the existing protocols to induce diabetes using STZ. We also describe and compare the pathological presentations, in both morphological and functional aspects, of the currently available DR animal models. The advantages and disadvantages of using different animals, ranging from zebrafish, rodents to other higher-order mammals, are also discussed. Until now, there is no single model that displays all the clinical features of DR as seen in human. Yet, with the understanding of the pathological findings in these animal models, researchers can select the most suitable models for mechanistic studies or drug screening.

The association of the IVS1-397T>C estrogen receptor α polymorphism with the regulatory conditions in longstanding type 1 diabetic girls

Type 1 diabetes is considered as pluricausal disease, whose etiology involves genetic predisposition as well as environmental factors that contribute to disease progression and pathogenesis. Women are believed to be more susceptible to develop autoimmune diseases, which may depend in part on the influence of sex hormones on the immune system. It was shown that estrogens may protect against the development of autoimmune disease by inducing the expansion of regulatory T cell pool and upregulating Foxp3 expression. Foxp3 is a transcription factor that controls the development and suppressive function of naturally occurring regulatory T cells CD4(+)Foxp3(+). Longstanding diabetes type 1 has features of low-grade chronic inflammation which may influence regulatory T cell subset by reducing their numbers or/and inhibiting their suppressive potential. As diabetic type 1 patients are differentiated with regard to metabolic factors, level of glycemic control and systemic inflammatory state, we aimed to examine if this can be associated with IVSI-397T>C estrogen receptor α polymorphism. We examined 93 young regularly menstruating girls with diagnosed type 1 diabetes and 49 healthy age-matched control individuals. The PvuII polymorphism of the ER-α gene was analyzed as well as the serum TNF level and the level of CD4(+)Foxp3(+) regulatory T cells in these individuals. Girls with type 1 diabetes had lower level of CD4(+)Foxp3(+) Tregs than their healthy counterparts. Regulatory T cells from these patients showed also lower expression of Foxp3 than Tregs in healthy, control group. In addition, DM1 girls bearing the CC genotypes showed the highest level of CD4(+)Foxp3(+) Tregs and the lowest TNF serum level in comparison to girls carrying CT or TT genotype. The CC DM1 carriers had also higher serum level of estrogens than girls bearing CT or TT genotype. We propose that different variants of IVS1-397 estrogen receptor α polymorphism may become additional genetic factor that influences regulatory conditions during diabetes type 1 in females.

Role of urinary biomarkers in the diagnosis of congenital upper urinary tract obstruction

Background:

Congenital obstructive uropathy constitutes a significant cause of morbidity in children. Currently, there is no reference standard for the diagnosis of renal obstruction in children. The noninvasive measurement of biomarkers in voided urine has considerable appeal as a potential application in children with congenital obstructive nephropathy. The aim of the present review is to explore the current role of biomarkers in the diagnosis and follow-up of obstructive uropathy in children.

Materials and Methods:

The literature database (PubMed) was searched from inception to May 2007 regarding the role of urinary biomarkers in the diagnosis and follow-up of children with congenital obstructive uropathy.

Results:

The review included 23 experimental and 33 prospective controlled clinical studies. Several cytokines, peptides, enzymes and microproteins were identified as major contributors to or ensuing from obstruction-induced renal fibrosis and apoptosis. The most important biomarkers were transforming growth factor-β₁ (TGFβ₁), epidermal growth factor (EGF), endothelin-1 (ET-1), urinary tubular enzymes [N-acetyl-β-D-glucosaminidase (NAG), γ-glutamyl transferase (GGT) and alkaline phosphatase (ALP)], and microproteins [β₂-microglobulin (β₂M), microalbumin (M. Alb) and micrototal protein (M.TP)]. All biomarkers showed different degrees of success but the most promising markers were TGFβ₁, ET-1 and a panel of tubular enzymes. These biomarkers showed sensitivity of 74.3% to 100%, specificity of 80% to 90% and overall accuracy of 81.5% to 94% in the diagnosis of congenital obstructive uropathy in children. Moreover, some of the markers were valuable in differentiation between dilated non-obstructed kidneys in need of conservative management and obstructed kidneys in need of surgical correction. Some studies demonstrated that urinary biomarkers are helpful in the evaluation of success of treatment of children with congenital renal obstruction. Some limitations of the previous studies include lack of different types of controls and small sample size. Larger studies with variable controls are invited to confirm the clinical usefulness of biomarkers in the diagnosis and follow-up of children with congenital obstructive uropathy.

Conclusion:

Urinary biomarkers are a promising tool that could be used as a noninvasive assessment of congenital renal obstruction in children.

Pro- and anti-inflammatory cytokines in latent autoimmune diabetes in adults, type 1 and type 2 diabetes patients: Action LADA 4

AIMS/HYPOTHESIS

Systemic pro- and anti-inflammatory cytokines are associated with both type 1 and type 2 diabetes, while their role in latent autoimmune diabetes in adults (LADA) is unclear. Therefore, we compared cytokine concentrations in patients with LADA, type 1 or type 2 diabetes and healthy individuals to test the hypothesis that differences of cytokine concentrations between all groups are attributable to diabetes type and BMI.

METHODS

The pro-inflammatory cytokines IL-6 and TNF-α, and the anti-inflammatory cytokines IL-1 receptor antagonist (IL-1RA) and IL-10 were measured in 90 participants with type 1 diabetes, 61 with LADA, 465 with type 2 diabetes and 41 control participants using multiple regression models adjusted for BMI, sex, age, blood pressure and diabetes duration.

RESULTS

Patients with type 2 diabetes had higher concentrations of systemic IL-1RA, IL-6 and TNF-α cytokines than patients with either LADA or type 1 diabetes (p < 0.0001 for all differences). Cytokine concentrations in controls were lower than those in all diabetes types (p < 0.04). Increased BMI was positively associated with higher systemic cytokine concentrations in all diabetes types (p < 0.0001). Despite the association of cytokines with anthropometric data, differences between diabetes forms persisted also after adjusting analysis for the confounders BMI, age, sex, disease duration and blood pressure (p < 0.04).

CONCLUSIONS/INTERPRETATION

Although body mass associates positively with pro- and anti-inflammatory cytokine levels, patients with type 2 diabetes have higher cytokine levels independent of the prevailing BMI. LADA and type 1 diabetes could not be distinguished by systemic cytokines.

Urinary biomarkers in prenatally diagnosed unilateral hydronephrosis

The introduction of prenatal ultrasonography as a screening method entails an increasing number of infants diagnosed with prenatal hydronephrosis. Ureteropelvic junction obstruction accounts for 35% of prenatal hydronephrotic cases. Urinary tract obstruction that occurs during early kidney development affects renal morphogenesis, maturation and growth, and in the most severe cases this will ultimately cause renal insufficiency. A major challenge in the clinical management of these patients is to preserve renal function by selection of the 15%-20% who require early surgical intervention, leaving those for whom watchful waiting may be appropriate because of spontaneous resolution/stabilization without significant loss of renal function. Today, this requires medical surveillance, including repetitive invasive diuretic renograms relying on arbitrary threshold values, and therefore there is a need for non-arbitrary, non-invasive urinary biomarkers that may be used as predictors for renal structural changes and/or decreasing renal function, and thereby provide the surgeon with more clear indications for surgical intervention. In this review, we summarize the currently well-known facts about urinary biomarkers in ureteropelvic junction obstruction concerning renal function, and we also suggest potential novel urinary biomarkers.

Increased spontaneous production of VEGF by CD4+ T cells in type 1 diabetes

In the present study we report that CD4(+) T cells from patients with type 1 diabetes produce significantly higher amounts of VEGF than respective cells from the healthy individuals. Among CD4(+) T cells memory subsets were the main source of VEGF. In addition, memory CD4(+) T subsets were the most numerous in patients with diabetic retinopathy (DR). DR was also characterized by significant increase of VEGF concentration in serum and culture supernatants. Hence, these data indicate that there is a sustained spontaneous production of VEGF by CD4(+) T cells in type 1 diabetes, which is additionally exacerbated in DR. In our opinion alterations in the proportions of CD4(+) T cell subsets and their VEGF production may be a useful tool for early assessment of the risk of DR onset and progression.

Urinary biomarkers involved in type 2 diabetes: a review

Diabetes mellitus is one of the most challenging health concerns of the 21st century. With at least 30% of the diabetic population remaining undiagnosed, effective and early diagnosis is of critical concern. Development of a diagnostic test, more convenient and reliable than those currently used, would therefore be highly beneficial. Urine as a diagnostic medium allows for non-invasive detection of biomarkers, including some associated with type 2 diabetes and its complications. This review provides a synopsis of those urinary biomarkers that potentially may provide a basis for the development of improved diagnostic tests. Three main pathways for the sourcing of potential makers are identified: kidney damage, oxidative stress and low-grade inflammation including atherosclerosis/vascular damage. This review briefly presents each pathway and some of the most relevant urinary biomarkers that may be used to monitor the development or progression of diabetes and its complications. In particular, biomarkers of renal dysfunction such as transferrin, type IV collagen and N-acetyl-beta-D-glucosaminidase might prove to be more sensitive than urinary albumin, the current gold standard, in the detection of incipient nephropathy and risk assessment of cardiovascular disease. Inflammatory markers including orosomucoid, tumour necrosis factor-alpha, transforming growth factor-beta, vascular endothelial growth factor and monocyte chemoattractant protein-1, as well as oxidative stress markers such as 8-hydroxy-2'deoxyguanosine may also be useful biomarkers for diagnosis or monitoring of diabetic complications, particularly kidney disease. However, the sensitivity of these markers compared with albumin requires further investigation.

Pre-treatment serum levels of interleukin-10, interleukin-12 and their ratio predict response to therapy and probability of event-free and overall survival in childhood soft tissue sarcomas, Hodgkin's lymphomas and acute lymphoblastic leukemias

OBJECTIVES

Deregulated serum IL-10, IL-12 and their reciprocal balance have been stated in malignancies of adults. In children with cancer the issue has not been investigated so far.

DESIGN AND METHODS

To determine the diagnostic and prognostic roles of pre-treatment serum levels of IL-10 (Th2 cytokine), IL-12 (Th1) and their ratios (measured by the IL-10 and IL-12p70 ELISA kits; Endogen) in 91 children with soft tissue sarcomas (STS), Hodgkin's lymphomas (HL) and acute lymphoblastic leukemias (ALL).

RESULTS

Median IL-10 and IL-12 levels were significantly higher in cancer patients than in healthy controls. Increased IL-10 indicated presence of general symptoms in HL and high risk group in ALL. Elevated IL-10 and IL-10/IL-12 ratios and decreased IL-12 correlated with poor-risk histology in STS, poor response to therapy, relapse and death from cancer. Multivariate analysis identified IL-10/IL-12 ratio>0.14 and IL-12<40 pg/mL as significant predictors for shorter EFS and OS, respectively.

CONCLUSION

Pre-treatment serum levels of IL-10, IL-12 and IL-10/IL-12 balance in children with STS, HL and ALL may be of value as additional prognostic tools to predict the response to therapy and probability of EFS and OS.

Immunologic and biochemical factors of coincident celiac disease and type 1 diabetes mellitus in children

The objective of the study was to investigate whether immunologic and biochemical events occurring in the course of type 1 diabetes mellitus might play a role in the development of the celiac disease. The study was carried out on 223 children with long-standing diabetes mellitus type 1 (DM1). All the patients had TSH, fT4, fT3, urinary albumin secretion rate, IgA, level of antigliadin antibodies (AGA) IgA and IgG, antitissue transglutaminase IgA antibodies, antiendomysium (EmA) IgA and IgG antibodies and antitireoglobulin antibodies, antithyroid peroxidase antibodies evaluated. Serum TNF-alpha, IL-6, and IL-10 levels were also measured. The group of children with coincident DM1 and celiac disease and without autoimmune thyroiditis was characterized by significantly higher glycosylated hemoglobin, higher serum TNF-alpha, IL-6 but lower serum IL-10 in relation to the remaining diabetic patients. A statistically significant positive correlation was observed between IgA-anti-tTG and serum TNF-alpha (R = 0.28, p = 0.026); between IgG AGA and serum IL-6 (R = 0.31, p = 0.023); and between glycosylated hemoglobin and IgA-anti-tTG (R = 0.21, p = 0.001) and IgA antiendomysium (R = 0.22, p = 0.001). Poor metabolic control, persistent elevated levels of proinflammatory cytokines, and decreased level of antiinflammatory cytokines occurring in the course of type 1 diabetes mellitus might influence the incidence of celiac disease.

Serum N-acetyl-beta-D-glucosaminidase profiles in type 1 diabetes secondary complications: causes of changes and significance of determination

The connection between changes in the activity of serum N-acetyl-beta-D-glucosaminidase (NAG, E.C.3.2.1.30) and iso-enzymes and degree of secondary complications was analyzed in four groups of type 1 diabetic patients (n=69): without complications (n=22); with retinopathy (n=16); with retinopathy and polyneuropathy (n=13), and with retinopathy, neuropathy, and nephropathy (n=18). In all groups statistically significant higher (P<0.001) percent fraction of A form (83.84+/-6.09, 84.37+/-5.74, 81.76+/-6.02, 76.37+/-7.38%, resp.) and lower (P<0.001, P<0.01) fraction of B form (15.87+/-5.65, 15.66+/-5.74, 18.33+/-5.98, 23.63+/-7.38, resp.) in total NAG compared with the control (A=69.38+/-4.79%, B=30.61+/-4.78%) were found. The differences in A as well as B forms between diabetic groups were not statistically significant. Significant strong positive correlations between total NAG and glycemia (0.494-0.623), total NAG and A form (0.934-0.966), and A form and glycemia (0.512-0.638) were found in all groups. No correlation was found between the fractions of B and A forms, except in the fourth group. The A form of diabetic patients in the fourth group was more acidic compared with the control and other diabetic groups. It was concluded that the changes in serum NAG and iso-enzymic profiles in diabetes are the consequence of its increased exocytose, especially of the A form, in hyperglycemia and posttranslational modifications of iso-enzymes. The total activity of serum NAG and iso-enzymic profiles cannot be used for monitoring the development and distinction of type 1 diabetes secondary complications.

Contributions of inflammatory processes to the development of the early stages of diabetic retinopathy

Diabetes causes metabolic and physiologic abnormalities in the retina, and these changes suggest a role for inflammation in the development of diabetic retinopathy. These changes include upregulation of iNOS, COX-2, ICAM-1, caspase 1, VEGF, and NF-κB, increased production of nitric oxide, prostaglandin E2, IL-1β, and cytokines, as well as increased permeability and leukostasis. Using selective pharmacologic inhibitors or genetically modified animals, an increasing number of therapeutic approaches have been identified that significantly inhibit development of at least the early stages of diabetic retinopathy, especially occlusion and degeneration of retinal capillaries. A common feature of a number of these therapies is that they inhibit production of inflammatory mediators. The concept that localized inflammatory processes play a role in the development of diabetic retinopathy is relatively new, but evidence that supports the hypothesis is accumulating rapidly. This new hypothesis offers new insight into the pathogenesis of diabetic retinopathy, and offers novel targets to inhibit the ocular disease.

Interleukin-12 and tumour necrosis factor-alpha equilibrium is a prerequisite for clinical course free from late complications in children with type 1 diabetes mellitus

The objective of the study was to analyse levels of IL-12 and TNF-alpha and relate the findings to the occurrence of microangiopathy in children with type 1 diabetes mellitus (DM). We examined a group of 123 children with type 1 DM. Serum levels of IL-12 and TNF-alpha were measured by an immunoenzymatic ELISA technique. TNF-alpha and IL-12 tended to be simultaneously present or absent in the sera of 50% of the children who had not developed complications, thus indicating a state of cytokine's equilibrium. Among the patients with an established retinopathy, two IL-12/TNF-alpha combinations were visible. Either a lack of detectable TNF-alpha was accompanied by measurable IL-12 serum concentrations or TNF-alpha incidence was associated with undetectable IL-12 values. Simultaneous lack of TNF-alpha and presence of IL-12 was associated with a better prognosis as these patients had a significantly lower albumin excretion rate. The state of equilibrium between TNF-alpha and IL-12 is beneficial in patients at early stages of the disease, prior to the occurrence of complications. Shifting the equilibrium towards TNF-alpha seems to promote late complications. It may suggest that a disharmony between pro- and anti-angiogenic function of these cytokines underlie the mechanism by which TNF-alpha and IL-12 shape the disease course.

The role of vascular endothelial growth factor, tumor necrosis factor alpha and interleukin-6 in pathogenesis of diabetic retinopathy

The aim of the study was to analyze the relation between early diabetic retinopathy and the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF) in children with diabetes mellitus type 1. Two hundred and two children with diabetes mellitus type 1 aged 13.2+/-3.83 years and 85 healthy controls were analyzed. Patients were divided into two subgroups: children with retinopathy (Group 1, n=39) and children without retinopathy (Group 2, n=163). All the children had 24h urine albumin secretion rate, glycosylated hemoglobin HbA1c level, and C-reactive protein level measured, underwent 24h blood pressure monitoring and had ophthalmologic examination performed. Additionally, all the children had serum TNF-alpha, IL-6 and VEGF level measured using an ELISA test (Quantikine High Sensitivity Human). Statistically significant higher blood serum levels of HbA1c, VEGF, TNF-alpha and IL-6 were found in the Group 1 in comparison with the Group 2. Additionally, the children of the Group 1 showed statistically significant correlation between serum VEGF and serum TNF-alpha (R=0.35, p=0.000), CRP level (R=0.23, p=0.006), 24h albumin urine secretion rate (R=0.45, p=0.000) and duration of the disease (R=0.26, p=0.002). The results of the current study suggest that there is a relationship between VEGF, TNF-alpha, IL-6 and the development of the diabetic retinopathy in children with diabetes mellitus type 1.

Obstructed Versus Dilated Nonobstructed Kidneys in Children With Congenital Ureteropelvic Junction Narrowing: Role of Urinary Tubular Enzymes

PURPOSE

We evaluated the role of voided urine lysosomal enzyme N-acetyl-beta-D-glucosaminidase and brush border enzymes alkaline phosphatase and gamma-glutamyl transferase in differentiating between children with ureteropelvic junction obstruction in need of pyeloplasty and those with dilated nonobstructed kidneys suitable for conservative treatment.

MATERIALS AND METHODS

The study included 35 children with unilateral ureteropelvic junction obstruction treated with pyeloplasty (study group) and 15 children with dilated nonobstructed kidneys who were treated conservatively and followed for 15 months (control group). Voided urine samples were obtained before treatment from both groups, and from the study group at 1, 2, 3, 6, 9 and 12 months postoperatively and the control group at 3, 9 and 15 months of followup. N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase were measured in urine samples collected from both groups.

RESULTS

In the study group the activities of preoperative urinary N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase were significantly higher than in the control group. A cutoff value of 7.8 mU/mg creatinine N-acetyl-beta-D-glucosaminidase yielded a sensitivity of 97.1%, a specificity of 80% and an overall accuracy of 92%. A cutoff value of 34.5 IU/gm creatinine alkaline phosphatase resulted in a sensitivity of 91.4%, a specificity of 100% and an overall accuracy of 94%. A cutoff value of 54 IU/gm creatinine gamma-glutamyl transferase yielded a sensitivity of 62.9%, a specificity of 100% and an overall accuracy of 74%. The combination of urinary N-acetyl-beta-D-glucosaminidase and alkaline phosphatase resulted in a sensitivity of 100%, a specificity of 80% and an overall accuracy of 94%. Compared to preoperative activities, N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase decreased significantly at 12 months after pyeloplasty in the study group.

CONCLUSIONS

Voided urinary N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase are accurate markers for differentiating between children with ureteropelvic junction obstruction requiring pyeloplasty and those with dilated nonobstructed kidneys suitable for conservative treatment. Measurement of these enzymes in voided urine could be used as a noninvasive tool for long-term followup of children with ureteropelvic junction obstruction after pyeloplasty and those receiving conservative treatment.