Non-catalytic tyrosine-phosphorylated receptors

Leukocytes play a critical role in recognizing and responding to infection and cancer. Central to this function is an array of cell-surface receptors that lack sequence homology. Many of these receptors have in common the fact that their signaling involves phosphorylation of cytoplasmic domains by extrinsic tyrosine kinases. These non-catalytic tyrosine-phosphorylated receptors (NTRs) share a number of other features, including small size and optimal stimulation by surface–associated ligands. We argue here that NTRs are also likely to share the same kinetic-segregation triggering mechanism, which involves segregation of the engaged NTR from receptor tyrosine phosphatases with large ectodomains such as CD45 and CD148. NTRs signal through tyrosine-containing cytoplasmic motifs, which recruit distinct cytoplasmic signaling proteins when phosphorylated, transducing activatory or inhibitory signals. They have two features that make them uniquely well suited to their role in immune recognition of infection and cancer. Their modular structure enables the coupling of many rapidly evolving receptors with diverse ligand specificities to the same conserved signaling machinery. Their similarity in size and shared signaling machinery enables them to colocalize at cell-cell interfaces when they engage ligands, facilitating the integration of activatory and inhibitory signals from multiple receptors at the cell surface.     

Urokinase plasminogen activator receptor levels in Behcet's disease

Purpose

To determine urokinase plasminogen activator receptor (uPAR) concentrations in Behcet patients with and without ocular involvement; and to investigate the associations between uPAR levels and clinical manifestations of Behcet's disease.

Methods

Sixty-four patients with Behcet's disease (31 patients with and 33 patients without ocular involvement) and 23 healthy control subjects were included in this study. A complete ophthalmologic examination was performed. Venous blood was collected from all patients and control subjects. Serum uPAR levels were determined by using human uPAR immunoassay (Quantikine) kits.

Results

There was no statistically significant difference in serum uPAR levels between the patients and the control subjects (p > 0.05). There were no statistically significant correlations between uPAR levels and age, gender, duration of the disease, clinical manifestations (genital ulcer, arthritis, skin lesions, ocular and vascular involvements) and activity of the disease.

Conclusion

This finding is important since this is the first study regarding uPAR levels in Behcet's disease.     

Dialysate CA125 levels after 5 years on continuous peritoneal dialysis

The aim of this study was to evaluate longitudinal changes in dialysate cancer antigen 125 (dCA125) levels over time and to analyze relationships between dCA125 and peritoneal glucose exposure (PGE) in children undergoing long-term peritoneal dialysis (PD). The study group included seven boys and four girls (mean age 13 ± 5.1 years) with a mean PD duration of 84.0 ± 1.1 months. A peritoneal equilibration test (PET) was performed, and dCA125 levels were measured in all patients. Peritoneal appearance rates (AR) of dCA125, the velocity of the decrease in dCA125AR values, and annual PGE levels were also calculated. The final tests were performed at a mean of 63.3 ± 3.5 months after the initial ones. Both dCA125 and dCA125AR levels showed statistically significant decrements during the follow-up period (p = 0.003), with the velocity of decrease in dCA125AR found to be 52.6 ± 19.4%. There were no significant differences in peritoneal transport parameters between the beginning and end of the study period. PGE values were significantly higher in the last year of the study than in the first year (p = 0.014), but the velocity of the decrease in dCA125AR levels was not related to total PGE. In conclusion, a significant decline was found in dCA125 and CA125 AR levels, reflecting mesothelial cell mass, in children undergoing long-term PD (>5 years), but these were not related to PGE.     

Abdominal manifestations of polyarteritis nodosa demonstrated with CT

We report a rare case of polyarteritis nodosa (PAN) presenting in childhood. The child had multiple visceral aneurysms and later developed ascending colitis and jejunitis. The diagnosis was established with multidetector CT and CT angiography.     

Traditional and “new” cardiovascular risk markers and factors in pediatric dialysis patients

Cardiovascular disease (CVD) is the principal cause of mortality in patients with end-stage renal disease (ESRD). The aim of this study was to analyze carotid intima-media thickness (cIMT), endothelium-dependent dilatation (EDD), and left ventricular mass index (LVMI) as the cardiovascular risk markers and to investigate the independent risk factors of these markers in pediatric dialysis patients. This study included 39 children and adolescents undergoing dialysis (15 hemodialysis and 24 peritoneal dialysis) and 15 age- and gender-matched healthy subjects. The cIMT and EDD were assessed by high-resolution ultrasound, and LVMI was calculated from standard echocardiographic measurements. Compared with control subjects, cIMT standard deviation scores (SDS), LVMI, total homocysteine (tHcy), and high-sensitivity C-reactive protein (hs-CRP) values were significantly higher in patients, but EDD values did not differ. The mean hs-CRP level was significantly higher in hemodialysis (HD) patients than in peritoneal dialysis (PD) patients. The cIMT-SDS and LVMI were associated with several variables in univariate analysis. Stepwise linear regression analysis, indexed SBP (p = 0.017), and hemoglobin (p = 0.001) turned out to be independent variables for predicting LVMI, and a significant predictor of cIMT was indexed diastolic blood pressure (DBP) (p = 0.035). The causes of atherosclerosis and left ventricular hypertrophy are multifactorial in children and adolescents with ESRD. Better management of hypertension and anemia may be priorities for preventing or improving CVD in these patients.     

Study of mandibular alveolar distraction osteogenesis using a three-dimensional computed tomography measurement method: report of four patients, a preliminary study

OBJECTIVE: This study was conducted to show dimensional and volumetric changes after vertical alveolar distraction osteogenesis using a three-dimensional computed tomography measurement method. MATERIALS: Four patients with mandibular alveolar ridge atrophy were evaluated. Three-dimensional computed tomography reconstructions were obtained 2 weeks before and 3 months after the operation. The results of the three-dimensional computed tomography measurements were used for preoperative planning and for quantitative assessment of the mandibular alveolar distraction. The results of the preoperative and postoperative three-dimensional computed tomography measurements were compared statistically using paired t-test. RESULTS: The increase in distracted mandibular segment volume and surface area, height, and width of each slice after distraction were statistically significant (P < 0.001). CONCLUSION: In atrophic jaw cases, the dimensions of the present alveolar bone were clearly measured so that the amount of augmentation needed could be estimated. Three-dimensional computed tomography provided better understanding of the effects of distraction osteogenesis on the anterior mandible. Newly formed bone can be viewed as close to its real dimensions after distraction osteogenesis.