Urinary fibrogenic cytokines ET-1 and TGF-β1 are associated with urinary angiotensinogen levels in obese children

Background

Fibrogenic cytokines are recognized as putative drivers of disease activity and histopathological deterioration in various kidney diseases. We compared urinary transforming growth factor β1 (U-TGF-β1) and endothelin 1 (U-ET-1) levels across body mass index classes and assessed their association with the level of urinary angiotensinogen (U-AGT), a biomarker of intrarenal renin–angiotensin–aldosterone system (RAAS).

Methods

The was a cross-sectional evaluation of 302 children aged 8–9 years. Ambulatory blood pressure (BP), insulin resistance (HOMA-IR), aldosterone level and renal function were evaluated. U-ET-1, U-TGF-β1 and U-AGT levels were determined by immunoenzymatic methods.

Results

Obese children presented with the lowest levels of U-ET-1 and U-TGF-β1, but the difference was only significant for U-ET-1. In obese children, the median levels of both U-ET-1 and U-TGF-β1 tended to increase across tertiles (T1–T3) of U-AGT (U-ET-1: T1, 19.9 (14.2–26.3); T2, 32.5 (23.3–141.6); T3, 24.8 (18.7–51.5) ng/g creatinine, p?=?0.007; U-TGF-β1: T1, 2.2 (1.8–4.0); T2, 4.3 (2.7–11.7); T3, 4.9 (3.8–10.1) ng/g creatinine, p?=?0.004]. In multivariate models, in the obese group, U-ET-1 was associated with HOMA-IR and aldosterone and U-AGT levels, and U-TGF-β1 was associated with U-AGT levels and 24 h-systolic BP.

Conclusions

Whereas the initial hypothesis of higher levels of urinary fibrogenic cytokines in obese children was not confirmed in our study, both TGF-β1 and U-ET-1 levels were associated with U-AGT level, which likely reflects an early interplay between tissue remodeling and RAAS in obesity-related kidney injury.

     

Ageing and Toll-like receptor expression by innate immune cells in chronic human schistosomiasis

There has been no systematic study of the immune response of individuals aged over 60 years living in Schistosomiasis mansoni-endemic areas, although senescence is reportedly associated with susceptibility to infection and progressive decline in immune function. We have shown previously, in two endemic areas in Minas Gerais, Brazil, that the frequency of individuals aged over 60 years with chronic schistosomiasis is no longer negligible. Moreover, several elderly individuals who have always lived in these endemic areas stay protected from infection. An important question for studies of ageing and disease control in developing countries is which differences in the immunological profile of these negatively tested (non-infected) individuals can account for their resistance to either infection or reinfection. We show, in the present study, that non-infected (negative) elderly individuals develop innate immune mechanisms of protection that replace the age-associated decline in T cell function. Non-infected elderly individuals from endemic areas of schistosome infection present an increase in the frequency of the natural killer (NK) CD56(low) subset of NK cells expressing Toll-like receptors (TLR)-1, -2, -3 and -4 as determined by flow cytometry analysis. In addition, the proportion of dendritic cells expressing TLR-1 is elevated as well as the frequency of monocytes expressing TLR-1 and -4. These results suggest that TLR expression by cells of the innate immune system may be related to the negative status of infection in some elderly individuals who are constantly exposed to S. mansoni. Developing mechanisms of protection from infection may represent a biomarker for healthy ageing in this population.     

The launch of opicapone for Parkinson’s disease: negatives versus positives

Introduction: Opicapone is a novel, third generation COMT inhibitor approved for the treatment of Parkinson’s disease. Safety and tolerability data is critical to determine the benefit-harm balance and anticipate therapeutic adherence.

Areas covered: This review evaluates the tolerability and safety profile of opicapone. These data were extracted from all published clinical trials, including preclinical, phase I, phase II and phase III studies as well as postmarketing data. Opicapone was safe and well tolerated, with frequencies of treatment-emergent adverse events similar to placebo.

Expert opinion: Opicapone have shown a good safety and tolerability profile. This adds to its proven efficacy and convenient once-daily administration, supporting a role of opicapone as a first-line therapy for motor complications in Parkinson’s disease patients.     

USE OF CERVICAL VERTEBRAL DIMENSIONS FOR ASSESSMENT OF CHILDREN GROWTH

Objective:

The purpose of this study was to investigate whether skeletal maturation using cephalometric radiographs could be used in a Brazilian population.

Material and Methods:

The study population was selected from the files of the Oral Radiological Clinic of the Dental School of Piracicaba, Brazil and consisted of 128 girls and 110 boys (7.0 to 15.9 years old) who had cephalometric and hand-wrist radiographs taken on the same day. Cervical vertebral bone age was evaluated using the method described by Mito and colleagues in 2002. Bone age was assessed by the Tanner-Whitehouse (TW3) method and was used as a gold standard to determine the reliability of cervical vertebral bone age. An analysis of variance and Tukey''s post-hoc test were used to compare cervical vertebral bone age, bone age and chronological age at 5% significance level.

Results:

The analysis of the Brazilian female children data showed that there was a statistically significant difference (p<0.05) between cervical vertebral bone age and chronological age and between bone age and chronological age. However no statistically significant difference (p>0.05) was found between cervical vertebral bone age and bone age. Differently, the analysis of the male children data revealed a statistically significant difference (p<0.05) between cervical vertebral bone age and bone age and between cervical vertebral bone age and chronological age (p<0.05).

Conclusions:

The findings of the present study suggest that the method for objectively evaluating skeletal maturation on cephalometric radiographs by determination of vertebral bone age can be applied to Brazilian females only. The development of a new method to objectively evaluate cervical vertebral bone age in males is needed.     

Effect of low-level laser therapy (808 nm) on markers of muscle damage: a randomized double-blind placebo-controlled trial

The aim of this randomized double-blind placebo-controlled study was to investigate the effect of low-level laser therapy (LLLT) on markers of muscle damage (creatine kinase (CK) and strength performance) in the biceps brachii. Twenty-two physically active men were randomized into two groups: placebo and laser. All volunteers were submitted to an exercise-induced muscle damage protocol for biceps brachii (biceps curl, 10 sets of 10 repetitions with load of 50 % of one-repetition maximum test (1RM)). Active LLLT (808 nm; 100 mW; 35.7 W/cm², 357.14 J/cm² per point, energy of 1 J per point applied for 10 s on four points of the biceps brachii belly of each arm) or placebo was applied between the sets of the biceps curl exercise. CK activity and maximum strength performance (1RM) were measured before, immediately after, 24, 48, and 72 h after the exercise-induced muscle damage protocol. There was an increase in CK activity after the muscle damage protocol in both groups; however, this increase was attenuated in the laser group compared to the placebo group at 72 h (placebo?=?841 vs. laser?=?357 %; p?<?0.05). Maximum strength performance was decreased immediately after the muscle damage protocol in both groups (p?<?0.05), but at 24, 48, and 72 h, and it returned to the baseline level in both groups. In conclusion, the LLLT attenuated CK activity 72 h after the muscle damage protocol but did not have a positive effect on the recovery of strength performance.     

Vasorelaxation induced by methyl cinnamate,the major constituent of the essential oil of Ocimum micranthum,in rat isolated aorta

The aim of the present study was to investigate the vascular effects of the E‐isomer of methyl cinnamate (E‐MC) in rat isolated aortic rings and the putative mechanisms underlying these effects. At 1–3000 μmol/L, E‐MC concentration‐dependently relaxed endothelium‐intact aortic preparations that had been precontracted with phenylephrine (PHE; 1 μmol/L), with an IC₅₀ value (geometric mean) of 877.6 μmol/L (95% confidence interval (CI) 784.1–982.2 μmol/L). These vasorelaxant effects of E‐MC remained unchanged after removal of the vascular endothelium (IC₅₀ 725.5 μmol/L; 95% CI 546.4–963.6 μmol/L) and pretreatment with 100 μmol/L N^G‐nitro‐l ‐arginine methyl ester (IC₅₀ 749.0 μmol/L; 95% CI 557.8–1005.7 μmol/L) or 10 μmol/L 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one (IC₅₀ 837.2 μmol/L; 95% CI 511.4–1370.5 μmol/L). Over the concentration range 1–3000 μmol/L, E‐MC relaxed K⁺‐induced contractions in mesenteric artery preparations (IC₅₀ 314.5 μmol/L; 95% CI 141.9–697.0 μmol/L) with greater potency than in aortic preparations (IC₅₀ 1144.7 μmol/L; 95% CI 823.2–1591.9 μmol/L). In the presence of a saturating contractile concentration of K⁺ (150 mmol/L) in Ca²⁺‐containing medium combined with 3 μmol/L PHE, 1000 μmol/L E‐MC only partially reversed the contractile response. In contrast, under similar conditions, E‐MC nearly fully relaxed PHE‐induced contractions in aortic rings in a Ba²⁺‐containing medium. In preparations that were maintained under Ca²⁺‐free conditions, 600 and 1000 μmol/L E‐MC significantly reduced the contractions induced by exogenous Ca²⁺ or Ba²⁺ in KCl‐precontracted preparations, but not in PHE‐precontracted preparations (in the presence of 1 μmol/L verapamil). In addition, E‐MC (1–3000 μmol/L) concentration‐dependently relaxed the contractions induced by 2 mmol/L sodium orthovanadate. Based on these observations, E‐MC‐induced endothelium‐independent vasorelaxant effects appear to be preferentially mediated by inhibition of plasmalemmal Ca²⁺ influx through voltage‐dependent Ca²⁺ channels. However, the involvement of a myogenic mechanism in the effects of E‐MC is also possible.     

Microtubule reassembly in surface-activated platelets

It is generally accepted that a circumferential microtubule supports the discoid shape of resting platelets. The fate of the many-coiled polymer following platelet activation, however, has been a subject of considerable debate. Morphological investigations have suggested that the circumferential coils are constricted into tight rings around centrally concentrated organelles during platelet shape change. Biochemical studies employing colchicine-binding assays, on the other hand, have indicated that the bundle of microtubules dissolves almost completely within seconds after activation and reassembles in a new location one to four minutes later. The present study has accepted the latter hypothesis in order to examine the second part of the disassembly-reassembly theory proposed in biochemical studies. Platelets exposed to low temperatures sufficient to remove all microtubules were placed on glass slides and microscope grids to cause surface activation during rewarming. The combined stimuli of rewarming and surface activation might have been expected to cause more rapid assembly than warming alone or activation alone. This was not the case. Reassembly of microtubules during rewarming and simultaneous surface activation was not accelerated. In contrast to the constriction of microtubule rings observed during activation in control platelets, the diameters of coils that developed in chilled platelets one to two hours after rewarming and surface activation were twice those of control cells.     

Platelet activation by fMLP-stimulated polymorphonuclear leukocytes: the activity of cathepsin G is not prevented by antiproteinases

Human polymorphonuclear leukocytes (PMN) activated by fMLP (in the presence of CaCl2, fibrinogen, and cytochalasin B) were able to induce aggregation, cytoplasmic Ca2+ increase, and thromboxane A2 production in coincubated autologousplatelets. Cell-free supernatants prepared from n-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMN were able also to induce platelet activation. Antibodies against cathepsin G and different serin protease inhibitors completely suppressed the activity of PMN-derived supernatants, indicating that cathepsin G is the major platelet activator released by PMN in our system. However, antiproteinases only partially affected platelet activation induced by PMN in mixed cell suspensions. Superoxide dismutase and catalase added to the cell suspension did not affect platelet activation nor potentiated serin protease inhibitors, making a role for short-lived oxygen radicals in our experimental system unlikely. Electron microscopic observation of stirred mixed cell suspensions preincubated for 2 minutes at 37 degrees C before stimulation showed a close PMN- platelets contact without any morphologic or biochemical event suggesting platelet activation. Preincubation of the cells without stirring to minimize PMN-platelet interaction before stimulation did not modify subsequent aggregation and platelet cytoplasmic Ca2+ increase in control samples. However, in this condition trypsin inhibitor from soybean completely prevented PMN-induced platelet activation. In samples preincubated without stirring in the presence of the antiproteinase, activated PMN stuck together but platelets preserved their discoid shape and did not appear significantly activated. We propose that membrane-to-membrane contact could create a microenvironment in which cathepsin G, discharged from stimulated PMN on adherent platelets, is protected from antiproteinases.     

Pre-B acute lymphoblastic leukemia cells may induce T-cell anergy to alloantigen

Even if neoplastic cells express tumor associated antigens they still may fail to function as antigen presenting cells (APC) if they lack expression of one or more molecules critical for the induction of productive immunity. These cellular defects can be repaired by physiologic activation, transfection, or fusion of tumor cells with professional APC. Although such defects can be repaired, antitumor specific T cells may still fail to respond in vivo if they may have been tolerized. Here, human pre-B cell acute lymphoblastic leukemia (pre-B ALL) was used as a model to determine if primary human tumor cells can function as alloantigen presenting cells (alloAPC) or alternatively whether they induce anergy. In the present report, we show that pre-B cell ALL express alloantigen and adhesion molecules but uniformly lack B7-1 (CD80) and only a subset express B7-2 (CD86). Pre-B ALL cells are inefficient or ineffective alloAPC and those cases that lack expression of B7-1 and B7-2 also induce alloantigen specific T- cell unresponsiveness. Under these circumstances, T-cell unresponsiveness could be prevented by physiologic activation of tumor cells via CD40, cross-linking CD28, or signaling through the common gamma chain of the interleukin-2 receptor on T cells. Taken together, these results suggest that pre-B ALL may be incapable of inducing clinically significant T-cell-mediated antileukemia responses. This defect may be not only due to their inability to function as APC, but also due to their potential to induce tolerance. Attempts to induce clinically significant antitumor immune responses may then require not only mechanisms to repair the antigen presenting capacity of the tumor cells, but also reversal of tolerance.