Vitamin D has a wide range of biological effects mediated through vitamin D receptor(VDR) in body,including regulating calcium-phosphorus metabolism,which has an important influence on normal bone formation and mineralization.Rickets is a common bone metabolic disease in children.Different types of rickets have different causes,but their pathophysiological processes,clinical manifestations and treatments are closely related with the influence of vitamin D and VDR on bone metabolism.

Objective To evaluate effects of glucocorticoids on maxillary bone mineral density in rats with acute adriamycin-induced nephrotoxicity (ADR). Methods Forty rats were randomly divided into four groups, control group, glucocorticoids- treated group, ADR group and ADR + glucocorticoids- treated group. ADR group and ADR +glucocorticoids-treated group were given 4 mg/kg adriamycin injection via tail vein to establish ADR model. Control group and glucocorticoids-treated group were given 4 mg/kg saline injection via tail vein. After establishment of ADR model, glucocorticoids-treated group and ADR + glucocorticoids-treated group were intragastric administration of 30 mg/(kg · d) methylprednisolone for 10 weeks, and control group and ADR group were given the same volumes of normal saline. Values of bone calcium pigment (BGP), type Ⅰ collagen, N-terminal pro-peptide (PINP), β-Ⅰ type collagen C-terminal cross-linked telopeptide (CTX) were detected by ELISA. The micro-CT scan was used to measure Tb.Th, Tb.Sp, Tb.N, BVF and bone mineral density (BMD). Results Compared with other three groups, the levels of BGP and PINP were significantly decreased, and CTX were significantly increased in ADR + glucocorticoids-treated group (P<0.05). Micro-CT analysis showed that there was significant maxillae osteoporosis, including changes of porous micro architecture, lower BMD, decreased BVF, lower Tb.Th and widening Tb.Sp in ADR + glucocorticoids-treated group (P<0.05). There was no significant difference in Tb.N between four groups. Conclusion There is imbalanced bone metabolism in rat model of ADR. High-dose hormone therapy can accelerate the occurrence of osteoporosis, decrease bone metabolism, and affect bone structure.

Objective To investigate the local or systemic effects of initial periodontal therapy on peritoneal dialysis in patients with chronic kidney disease and periodontitis. Methods Sixty-one patients with both periodontitis and regular peritoneal dialysis were selected in this study and were randomly divided into observation group (n=31) and control group (n=30). Patients in observation group were given periodontal initial therapy (ultrasonic supragingival scaling and ultrasonic subgingival irrigation, drug, root planing, oral health education) and peritoneal dialysis treatment. Patients in control group were given only peritoneal dialysis treatment. Clinical parameters including plaque index (PLI), gingival index (GI) and probing depth (PD) were detected before and one month after treatment in two groups. The concentrations of high-sensitivity C-reactive protein (hs-CRP) in gingival sulcus fluid and serum samples were measured by immune transmission turbidity method in two groups. Results There were no significant differences in PLI, GI, PD, hs-CRP of gingival sulcus fluid, and serum hs-CRP before treatment between the two groups. After one-month initial therapy, all the indexes were decreased in observation group, which were significantly different compared with those before treatment (P<0.05). And all the indexes were significantly lower in observation group than those of control group. There were no significant differences in PLI, PD, GI, hs-CRP of gingival sulcus fluid, and serum hs-CRP between control group and observation group before treatment. Conclusion Periodontal initial treatment can improve the periodontal inflammation in patients with chronic kidney disease, and reduce the concentration of systemic inflammatory factor hs-CRP, decreasing the risk of infection.

The hybrid pencil beam model (HPBM) is an effective algorithm for calculating electron dose distribution in radiotherapy. The mean energy distribution of incident electron beam in phantom is one of the factors that affect the calculation accuracy of HPBM, especially in field edge areas near the end of the electron range. A new fitted formula based on Monte Carlo (MC) simulation data for electron beams with energy range of 6-20 MeV in the homogeneous water phantom is proposed in this paper. The precision of the fitted formula within the scope of the energy was evaluated by comparing the electron dose distribution of ECWG measured data with that obtained from HPBM which took the mean electron energy that calculated by the fitted formula and the existed empirical formula, respectively. The results showed that the accuracy of dose distribution that obtained by the mean electron energy calculated with the fitted formula increased about 1%.
Algorithms ; Electrons ; Humans ; Monte Carlo Method ; Phantoms, Imaging ; Radiotherapy Planning, Computer-Assisted ; Water

Objective To investigate the changes of thyroid autoantibody(TAA)in children with Turner syndrome(TS),and its association between TAA and thyroid dysfunction,age,karyotype and dyslipidaemia.Methods Thirty-two patients with TS diagnosed by chromosome analysis hospitalized at Sun Yat-Sen Memorial Hospital,Sun Yat-Sen University from July 2007 to July 2015 were divided into 2 groups based on TAA-positive or TAA-negative,then the thyroid dysfunction,the age,the karyotype and the lipid metabolism were compared between 2 groups.Results Of the 23 cases of TAA-positive girls(23/32 cases,71.88％),9 girls(39.13％)suffered from thyroid dysfunction;of the 9 cases of TAA-negative girls(9/32 cases,28.12％),3 girls(33.33％)had thyroid dysfunction.As compared with the girls in TAA-negative group,the age in TAA-positive group was significantly higher[(12.08±2.90)years old vs.(8.89±4.17)years old],and the difference was significant(t=101.500,P=0.047).The patients were divided into 4 age groups:0-5 years old,>5-10 years old,>10-15 years old and >15 years old;the rates with TAA-positive were 25.00％(1/4 cases),75.00％(6/8 cases),82.35％(14/17 cases)and 66.67％(2/3 cases)respectively.Twenty patients received the lipid metabolism test,and 11 cases(11/20 cases,55.00％)of them suffered from dyslipidaemia,9 cases of them were TAA-positive(9/11 cases,81.82％),and 2 cases were TAA-negative(2/11 cases,18.18％).The differences in the prevalence of dyslipidaemia between the 2 groups were significant(x2=4.848,P=0.028).There was no significant difference in the numbers of TAA-positive cases among different karyotypes(x2 =4.246,P=0.120).Conclusions Patients with TS are prone to suffer from thyroid dysfunction and dyslipidaemia.Timely detection of TAA and thyroid function is recommended,as well as the lipid metabolism if necessary.

As a method of dosimetric verification in radiotherapy, gamma index has been widely used for evaluating dose distribution in research and clinical cases. However, for three-dimensional dose distributions, gamma index calculation is very time consuming for the computers. In this paper, based on a pre-sorting technique, we implement a parallel computing algorithm of gamma index on graphic processing unit (GPU). Dose comparisons are performed for seven cases to test our new implementation. It was shown that the GPU-based gamma index calculations achieved a speedup of ten-folds in comparison with corresponding CPU implementation without losing accuracy. The result showed that utilizing GPU parallel computing to speed up gamma index calculations could be reliable and efficient in the implementation.
Algorithms ; Computer Graphics ; Humans ; Radiometry ; methods ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; methods ; Software

Objective: This study aimed at determining the characteristics of the glucose homeostasis and its relationship with iron overload of the patients with β-thalassemia major (β-TM). Method: From Sun Yat-sen Memorial Hospital between January 2014 and December 2015, a total of 57 transfusion-dependent β-TM patients with 5-18 years old were enrolled in this study and fasting blood glucose(FBG) and insulin level, serum ferritin (SF), serum iron, transferrin, total iron binding capacity, unsaturated iron binding capacity were determined.Insulin resistance index (IRI), insulin sensitivity index and β-cell function index (BFI) were also estimated. Besides, in 36 patients cardiac T2* and liver T2* were estimated. Result: (1) Four patients(7%) with β-TM were diagnosed diabetes mellitus, and 14(24%) had impaired fasting glucose. (2) The incidence of abnormal glucose metabolism was significantly different according to levels of SF and degrees of the cardiac iron overload(χ²=9.737, P<0.05; χ²=17.027, P<0.05). It rose while the level of SF increased and the degree of cardiac iron overload aggravated. (3) The incidence of abnormal glucose level was not significantly different in cases with different degree of liver iron overload.The severe group of liver iron overload had significantly higher levels of INS, HOMA-βFI, HOMA-ISI, HOMA-βFI than the non-severe group (Z=-2.434, -2.515, F=8.658, all P<0.05), while no differences were found in the level of FBG, HOMA-βFI between two groups. (4) The result of logistic regression analysis indicated that the cardiac T2* was a significant predictor for the incidence of abnormal glucose metabolism in TM patients (P=0.035, OR=1.182%, 95%CI=1.048 to 1.332). Conclusion The high prevalence of abnormal glucose metabolism in β-TM patients was mainly closely related with the internal iron overload, especially in organs.The cardiac T2* was an independent risk factor for the incidence of abnormal glucose metabolism in TM patients.

Objective To analyze the clinical manifestations and gene mutations of rare causes of primary adrenal insufficiency (PAI) in childhood.Methods The clinical features,laboratory tests and gene mutation of 13 patients with PAI in our hospital from September 2010 to August 2017 were analyzed retrospectively.Patients with congenital adrenal hyperplasia,X-linked adrenoleukodystrophy with neurological onset or a clear family history,and autoimmune adrenal insufficiency were excluded.Results The median age of 13 cases (12 males,1 female) was 3 years and 10 months.Medical history or clinical manifestations on the first visit included hyperpigmentation,electrolyte imbalance/salt-wasting crisis,gastrointestinal symptoms,and fatigue,etc.All developments of external genitalia were normal.All cases presented with decreased serum cortisol and increased ACTH levels.Some of the cases showed decreased aldosterone level and plasma renin activity,while 17α-hydroxyprogesterone,testosterone,and androstenedione were in the normal range.Part of cases revealed delayed bone age and adrenal atrophy.Three gene mutations were detected in 13 patients,including NR0B 1 gene (9/13),ABCD 1 gene (3/13),and CYP 11A 1 gene (1/13).NR0B1,and ABCD1 gene mutations were pathogenic mutations,consistent with clinical characteristics.CYP11A1 gene mutation was heterozygote,which cannot fully explain the clinical features.Conclusion PAI in childhood presents common clinical manifestations of adrenal insufficiency,e.g.hyperpigmentation and electrolyte imbalance/sah-wasting crisis,but without specificity.Gene mutational analysis is necessary for precise diagnosis and prognosis estimation.NR0B1 and ABCD1 gene mutations were common in childhood with rare causes of PAI.

ObjectiveTo explore the clinical features and causative genes of short stature children with unknown etiology， providing evidence for precise clinical diagnosis and treatment. MethodsThe study recruited children with suspected but undiagnosed short stature from the pediatric endocrinology department in our hospital between January 2018 and August 2022. A retrospective analysis was performed on the clinical manifestations， laboratory test and whole exome sequencing （WES） results. Causative genes were classified and analyzed according to different pathogenic mechanisms. ResultsA total of 48 children （30 boys and 18 girls） were enrolled， aged 7.73 ± 3.97 years， with a height standard deviation score （ HtSDS） of -3.63 ± 1.67. Of the patients， 33 （68.8%） suffered from facial anomalies， 31 （64.6%） from skeletal abnormalities， 26 ［54.2%， 61.5% of whom born small for gestational age （SGA）］ from perinatal abnormalities， 24 ［50.0%， 87.5% of whom with growth hormone （GH） peak concentration below normal］ from endocrine disorders and 21（43.8%） had a family history of short stature. Laboratory tests showed that GH peak concentration following stimulation test was （9.72 ± 7.25） ng/mL， IGF-1 standard deviation score was -0.82 ± 1.42， the difference between bone age and chronological age was -0.93 ± 1.39 years. Of the 25 cases with mutant genes found by WES， 14 （56.0%） had pathogenic mutation， 6 （24.0%） likely pathogenic mutation， and 5 （20.0%） mutation of uncertain significance. Pathogenic and likely pathogenic variants were identified in 14 genes， including 10 affecting intracellular signaling pathways （PTPN11， RAF1， RIT1， ARID1B， ANKRD11， CSNK2A1， SRCAP， CUL7， SMAD4 and FAM111A） and 4 affecting extracellular matrix （ECM） components or functions （ACAN， FBN1， COL10A1 and COMP）. ConclusionsA rare monogenic disease should be considered as the possible etiology for children with severe short stature accompanied by facial anomalies， disproportionate body types， skeletal abnormalities， SGA， GH peak concentration below normal and a family history of short stature. WES played an important role in identifying the monogenic causes of short stature. This study indicated that affecting growth plate cartilage formation through intracellular signaling pathways and ECM components or functions was the main mechanism of causative genes leading to severe short stature in children. Further research may help discover and study new pathogenic variants and gene functions.