Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs). In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells) and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy and uncontrolled cutaneous and internal organs fibrosis. Diagnosis of SSc in an early phase can be difficult because of a lack of typical symptoms. The delay in diagnosis and treatment of SSc may lead to uncontrolled progression of the disease, thus identification of possible early indicators of skin and organ involvement to prevent their further damage is necessary. The aim of this study is to review the latest biomarkers of organ involvement in SSc. In patients with lung fibrosis lung-epithelial-derived surfactant protein (SP-D), the glycoprotein Krebs von den Lungen-6 (KL-6), and chemokine ligands 2, 4 and 18 (CCL2, CXCL4, CCL18) are elevated, while in patients with skin fibrosis serum levels of heat shock protein 27 (Hsp27), interleukin 16 (IL-16), and IgG–galactosylation ratio are increased. Adiponectin concentration is inversely correlated with the intensity of cutaneous fibrosis. Skin gene profiling also seems very promising. In patients with heart involvement increased serum levels of brain natriuretic peptide (BNP) are present, as well as raised Midkine and Follistatin-like 3 (FSTL3) proteins, ratios of Cu/Se and ceruloplasmin(CP) /Circulating selenoprotein P(SELENOP) and higher whole blood viscosity level. Elevated calprotectin levels are found in individuals with gastrointestinal involvement. Increased levels of chemerin and ARA autoantibodies are associated with renal involvement, whereas high levels of adhesion molecules are found in patients with scleroderma renal crisis (SRC). Currently there are no biomarkers in use that can specifically identify the early involvement of organs.

Enhanced level of soluble urokinase plasminogen activator receptor (suPAR) level has been associated with activation of the immune system. It may be a novel biomarker for pneumonia severity, yet data on this subject are limited. In the present study we seek to determine the suPAR level in hospitalized children with community-acquired pneumonia (CAP), its correlation with pneumonia severity, and to compare the suPAR level between pneumonia and healthy conditions. The study encompassed a total of 596 children: 447 with pneumonia and 119 healthy. suPAR was measured in 227 out of the 447 pneumonia patients and in all healthy subjects. We used clinical indicators (fever, time for defeverscence, heart and breath rate, saturation, and length of antibiotic treatment and of hospitalization) and laboratory indicators (CRP, procalcitonin, white blood cell count, and sodium) to assess the CAP severity. The finding were that the suPAR concentration in children with pneumonia was significantly higher (median 7.11 ng/mL) than in healthy individuals (4.68 ng/mL). We found a positive correlation between the suPAR and the following factors: fever, time for defeverscence, length of hospital stay, and elevated CRP and procalcitonin levels. There was a reverse correlation with sodium concentration and capillary blood saturation. Moreover, the suPAR level was significantly higher in children with a severe course of pneumonia compared with those having non-severe pneumonia (7.79 vs. 6.87 ng/mL; p = 0.006). In conclusion, suPAR elevation is observed in pneumonia and may reflect its severity.

Copeptin has been associated with the severity of pneumonia and its complications. This study was designed to assess the usefulness of copeptin measurement in children with community-acquired pneumonia (CAP) and copeptin's relation with disease severity and sodium equilibrium. The study encompassed 311 patients (227 with pneumonia and 84 healthy controls) aged 8 days-18 years. Clinical findings and inflammatory markers were used to predict the disease severity. We found that the level of copeptin was significantly higher in patients with CAP (median 0.88 ng/mL) vs. healthy children (0.33 ng/mL; p < 0.01). ROC analysis showed a high AUC value (0.87) and the cut-off point for plasma copeptin level was 0.44 ng/mL, with a high sensitivity (89 %) and specificity (73 %) in recognizing pneumonia. Patients with higher copeptin concentrations were at higher risk of hyponatremia (OR 2.43). Yet there was only a weak reverse correlation between the sodium and the copeptin concentrations (Spearmann's rank coefficient = -0.19). The levels of copeptin were higher in hyponatremic patients (0.83 ng/mL) vs. normonatremic patients (0.69 ng/mL; p = 0.02). Copeptin elevation did not reflect the CAP severity measured with traditionally used methods. In conclusion, copeptin elevation is a promising marker of pneumonia, but it reflects neither the disease severity nor sodium concentration.

Community-acquired pneumonia (CAP) is a leading single cause of mortality in children under 5 years of age. In search of new diagnostic markers, soluble urokinase plasminogen activator receptor (suPAR) seems to offer promise as a novel clinical tool. The goal of the present study was to assess the relation between suPAR and the severity of CAP. suPAR was measured in 74 (39 males, 35 females) patients aged from 1 month to about 15 years. Correlation between the level of suPAR and inflammatory markers (white blood cell, neutrophil count, C-reactive protein-CRP, and procalcitonin-PCT) was assessed by Spearmann's rank coefficient. We found that the median suPAR level in children with pneumonia was 8.29 ng/mL (range 2.44-18.31 ng/mL). In the multivariate logit model, age and CRP level were statistically important. The older children (age above the median value) had higher suPAR (above the median value) less frequently than the younger children (OR = 0.31), whereas the children with greater CRP values (above the median value) had higher suPAR levels than the children with lower CRP concentration (under the median value) (OR = 4.54). There was also a positive correlation between suPAR and PCT levels. In conclusion, we demonstrate a positive correlation between serum suPAR and the non-specific inflammatory markers CRP and PCT in the community acquired pneumonia in children.