Objective To view and compare the clinical characteristics of renal tubular acidosis in adults and children.Methods Clinical data of patients with renal tubular acidosis diagnosed by Shandong Provincial Hospital affiliated to Shandong University from Jan 1991 to Sep 2017 were reviewed.The difference and consistency in clinical characteristics of renal tubular acidosis between adults and children were analyzed.Results Data from 206 adults and 60 children were analyzed.89.81％ cases in adults were secondary to other diseases,mainly primary Sjogren's syndrome.Most children patients (81.67％) were idiopathic,others largely originated from inherited metabolic diseases.The most common subtype of both was distal renal tubular acidosis.Proximal renal tubular acidosis was easier to be found in idiopathic renal tubular diseases of children.Chief complaints or starting symptoms were mainly composed of polydipsia with polyuria (41.4％) and fatigue (35.3％).Children were typical of growth retardation,rickets and digestive symptoms.The rate of missed diagnosis and misdiagnosis was 41.4 percent.Routine therapy consisted of healing metabolic acidosis and electrolyte disorders,treating underlying diseases and preventing complications.The majority of patients (95.5％) improved after treatments.Conclusions Renal tubular acidosis possesses various underlying diseases,diverse clinical manifestation and high rate of misdiagnosis.Given the high incident of secondary types,investigation of underlying disease,especially autoimmune diseases such as Sjogren's syndrome,is of great importance in adults.Most children patients suffer from primary renal tubular acidosis.Attention should be paid to them in order to reduce the rate of misdiagnosis and teratogenicity.

Objective: To synthesize a folic acid (FA)-modified pH-sensitive nanomicelle containing sorafenib (SF) and superparamagnetic iron oxide (SPIO), and to access its visibility in MRI and anti-cancer efficacy on hepatocellular carcinoma (HCC) in vitro. Methods: The copolymer FA-PEG-Pasp (DBA/DIP) of FA, poly(ethylene glycol), N,N-dibutylethylenediamine and N,N-diisopropylethylenediamine grafted poly (L-aspartic acid) were prepared. SF and SPIO were encapsulated inside the copolymer to synthesize the targeting micelle FA-PEG-PAsp (DBA/DIP)-SPIO/SF (FPASS). The folate-free micelle[PEG-PAsp (DBA/DIP)-SPIO/SF (PASS)] was used as nontargeting micelle. The physicochemical properties and drug release behavior of the micelles were analyzed. MRI of HepG2 cells incubated with FPASS and PASS with different Fe concentrations and Prussian blue staining of cells treated with the micelles (Fe concentration of 20 μg/ml) was performed to assess the drug delivery capability and imaging function of the micelles. For the FA competitive inhibition assay in these experiments, HepG2 cells were pre-treated with an excess amount of free FA prior to the incubation with FPASS. Cell viability, cell apoptosis, cell cycle and tube formation assays were conducted for evaluating the anti-HCC effects of the micelles. Comparison between groups was analyzed by one-way ANOVA, and multiple comparisons correction was performed by LSD test. Results: The diameters of FPASS and PASS were (102.3±5.2) nm and (107.1±5.7) nm, respectively; the δ potentials of them were (29.7±1.6) mV and (31.5±1.4) mV, respectively. The T₂ relaxivity of both the micelles was (5.2±0.4) ml·μg^-1·s^-1, which was much higher than that of water soluble Fe₃O₄ nanoparticles [(2.3±0.1) ml·μg^-1·s^-1; F=76.45, P<0.01]. SF released from the micelles was much faster at pH5.0 than at pH7.4, which indicated that the micelles had a pH-triggered drug release behavior. MRI of HepG2 cell samples revealed the signal intensity on T₂WI images and the T₂ value on T₂-map images decreased with the increasing Fe concentrations in the micelles. At the same Fe concentration (5, 10, 20 and 40 μg/ml), the cells of FPASS group exhibited a more significant decrease in T₂ signal intensity and T₂ value compared with those of PASS group or FA competitive inhibition group (F=8.69, 14.03, 27.27, 32.25 and 19.80, 45.76, 113.20, 66.80; P<0.01). Prussian blue staining verified the existing of SPIO in the cytoplasm of cells. Compared with PASS, FPASS presented significantly higher anticancer effects on inducing apoptosis, causing G0/G1 phase arrest on HepG2 cells and inhibiting tube formation on human umbilical vein endothelial cells (t=7.905, 4.399 and 3.454, respectively; P<0.01). Conclusions The pH-sensitive nanomicelle FPASS was successfully constructed. This micelle possessed a hypersensitive MRI-visible function and a targeting SF delivery capability which may contribute to a significant anti-HCC effect.