[Clinical and imaging features of infective sacroiliitis in children].

Objective: To summarize the clinical, radiological characteristics, and prognosis of infectious sacroiliitis in children. Methods: A case-control study was conducted, including 12 cases of infectious sacroiliitis diagnosed in the Rheumatology and Immunology Department of the Children's Hospital affiliated with the Capital Institute of Pediatrics from June 2018 to June 2023. These cases comprised the case group. Concurrently, 28 cases of pediatric idiopathic arthritis involving the sacroiliac joint in the same department served as the control group. Basic patient information, clinical features, laboratory parameters, and clinical treatment outcomes for both groups were collected and analyzed. Independent sample t-tests and chi-squared tests were used for inter-group comparisons. Results: Among the 12 cases in the case group, there were 5 males and 7 females, with a disease duration of 0.8 (0.5, 1.2) months. Nine patients presented with fever, and 1 patient had limping gait. Human leukocyte antigen (HLA)-B27 positivity was observed in 1 case, and there was no family history of ankylosing spondylitis. In the control group of 28 cases, there were 19 males and 9 females, with a disease duration of 7.0 (3.0, 17.0) months. One patient (4%) had fever, and 14 cases (50%) exhibited limping gait. HLA-B27 positivity was found in 18 cases (64%), and 18 cases (64%) had a family history of ankylosing spondylitis. The case group had higher white blood cell count (WBC), neutrophil ratio, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels, as well as a higher proportion of unilateral involvement on magnetic resonance imaging and bone destruction on CT compared to the control group ((11.1±6.2)×109 vs. (7.3±2.3)×109/L, 0.64±0.10 vs. 0.55±0.12, 72 (34, 86) vs. 18 (5, 41) mm/1 h, 24.6 (10.1, 67.3) mg/L vs. 3.6 (0.8, 15.0) mg/L, 11/12 vs. 36% (10/28), 9/12 vs. 11% (3/28), t=2.90, 3.07, Z=-2.94, -3.28, χ2=10.55, 16.53, all P<0.05). Conclusions: Pediatric infectious sacroiliitis often presents as unilateral involvement with a short disease history. Elevated WBC, CRP, and ESR, as well as a high rate of bone destruction, are also common characteristics.

[Clinical features and prognosis of 118 children with histiocytic necrotizing lymphadenitis].

Objective: To explore the clinical features and prognosis of children with histiocytic necrotizing lymphadenitis (HNL). Methods: The clinical data of 118 children with HNL diagnosed and treated in the Department of Rheumatology and Immunology of Children's Hospital, Capital Institute of Pediatrics from January 2014 to December 2021 were retrospectively analyzed. The clinical symptoms, laboratory examination, imaging examination, pathological findings, treatment and follow-up were analyzed. Results: Among the 118 patients, 69 were males and 49 were females. The age of onset was 10.0 (8.0, 12.0) years, ranging from 1.5 to 16.0 years. All the children had fever lymph node enlargement, blood system involvement in 74 cases (62.7%), skin injury in 39 cases (33.1%). The main manifestations of laboratory examination were increased erythrocyte sedimentation rate in 90 cases (76.3%), decreased hemoglobin in 58 cases (49.2%), decreased white blood cells in 54 cases (45.8%) and positive antinuclear antibody in 35 cases (29.7%). Ninety-seven cases (82.2%) underwent B-mode ultrasound of lymph nodes, showing nodular lesions with low echo in the neck; 22 cases (18.6%) underwent cervical X-ray and (or) CT; 7 cases (5.9%) underwent cervical magnetic resonance imaging. Lymph node biopsy was performed in all 118 cases, and the pathological results did not support malignant diseases such as lymphoma or Epstein-Barr virus infection, suggesting HNL. Fifty-seven cases (48.3%) recovered without treatment, 61 cases (51.7%) received oral steroid therapy, and 4 cases (3.4%) received indomethacin as anal stopper. The 118 cases were followed up for 4 (2, 6) years, ranging from 1 to 7 years, 87 cases (73.7%) had one onset and did not develop into other rheumatological diseases, and 24 cases (20.3%) had different degrees of recurrence, 7 cases (5.9%) had multiple system injuries, and all of the tested autoantibodies were positive for medium and high titers. All of them developed into other rheumatic immune diseases, among which 5 cases developed into systemic lupus erythematosus and 2 cases developed into Sjogren's syndrome; 7 cases were given oral steroid therapy, including 6 cases plus immunosuppressant and 2 cases receiving methylprednisolone 20 mg/kg shock therapy. Conclusions: The first-onset HNL portion is self-healing, hormone-sensitive and has a good prognosis. For HNL with repeated disease and multiple system injury, antinuclear antibody titer should be monitored during follow-up, and attention should be paid to the possibility of developing into other rheumatological diseases, with poor prognosis.

[Analysis of 13 cases with pediatric rheumatic disease combined with endocrine disorder].

Objective: To summarize the clinical characteristics of children with rheumatic disease combined with endocrine disorder. Methods: A retrospective analysis was performed on the clinical data, including sex, age, clinical presentation, laboratory tests, treatment and outcome, of 13 patients with rheumatic diseases combined with endocrine disorder, who were admitted to our department in Children's Hospital, Capital Institute of Pediatrics from January 2014 to December 2020. Results: Among the 13 cases, 3 were males and 10 were females, without family history. Their age was (10±4) years. And the average course of disease was 4.1 months. Eight of them were diagnosed with systemic lupus erythematosus (JSLE), 2 with juvenile idiopathic arthritis (JIA), 1 with childhood vasculitis, 1 with juvenile-onset systemic sclerosis (JSSc) and 1 had juvenile dermatomyositis (JDM). Regarding the initial presentation, 10 cases had symptoms of rheumatic disease, 2 had polydipsia and polyuria, and 1 had goiter. All the 13 patients had multiple system involvement. Regarding endocrine disorder, 10 had thyroiditis or subclinical thyroiditis, 4 had diabetes mellitus and one had both thyroid and pancreas involvement. Thyroid stimulating hormone in 10 patient with thyroid involvment was 19.6 (5.2-34.0) mU/L, and their total thyroxine was 75.3 (45.2-105.4) nmol/L. Besides, thyroid peroxidase antibody or thyroglobulin antibody was positive in 7 cases. The blood glucose of 4 children with pancreatic injury was 25.0 (17.0-33.0) mmol/L, and C-peptide was 0.4 (0.3-0.5) mg/L. Glutamate dehydrogenase antibody, protein tyrosine phosphatase antibody and zinc transporter 8 antibody were positive in two cases. After treatement with immunosuppressant or immunoglobulin combined with glucocorticoid or nonsteroidal antiinflammatory drugs for rheumatic symptoms, and levothyroxine or insulin for endocrine diseases, they were all followed up for more than 6 months and maintained clinical stability. Conclusions: Rheumatic diseases in children can be complicated with endocrine disorders, and the involved organs are usually thyroid and pancreas. In children with rheumatic disease, thyroid injury usually has subtle onset, whereas pancreas injury develops rapidly, even life-threatening. Insulin should be used persistently under the instruction of endocrinologist.

[Tocilizumab for refractory systemic juvenile idiopathic arthritis].

Objective: To evaluate the efficacy and side effects of tocilizumab for the treatment of systemic juvenile idiopathic arthritis. Method: In this prospective self case-control study, the children diagnosed with refractory systemic juvenile idiopathic arthritis admitted to Department of Rheumatism and Immunology of Children's Hospital Affiliated to Capital Institute of Pediatrics from December 2013 to June 2016 were enrolled and information before and after treatment of tocilizumab was analyzed. The tocilizumab was introvenously guttae in a dose of 8-12 mg/kg every 2 weeks. Complete blood count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were tested before and after the application of tocilizumab. Detailed clinical manifestations were recorded. All results were analyzed by χ(2) test and t test. Result: Forty patients with a median age of (6.6±3.7) years were enrolled, including 15 males and 25 females. All of the patients presented with fever and 38 patients got normal temperature 24-48 hours after treatment with tocilizumab. Symptoms disappeared in 13 and improved in 4 patients after treatment among the 17 patients who presented with arthritis. Within the 10 patients who manifested with rashes, 9 patients' rashes disappeared without relapse accompanied by the normalization of temperature after the treatment of tocilizumab. One patient got normal temperature but intermittently emerged rashes after symptoms of arthritis improved. In the 40 patients, 38 well tolerated tocilizumab while 2 showed rashes and chill which disappeared shortly after antianaphylaxis treatment. No severe treatment-related infection was found in any patients. According to the study, the white blood cell counts(×10(9)/L), CRP(mg/L) and ESR(mm/1h) tested 2 weeks after the treatment with tocilizumab were significantly lower than that before treatment(12.1±1.2 vs. 16.5±1.8, 47±8 vs. 67±9, 21±5 vs. 57±6, t=2.75, 3.98, 5.22, P=0.009, 0, 0, respectively). No significant changes were found in concentration of IL-6 and TNF-α (65(207) vs. 45(137) ng/L, and 14(6) vs. 17(19)ng/L, Z=-1.247 and-1.285, P=0.212 and 0.199 respectively). Conclusion: Tocilizumab is a treatment with good efficacy and safety for refractory systemic juvenile idiopathic arthritis. Adverse effects would be found in some patients.

[Characteristics of the joint involvement in fibrodysplasia ossificans progressiva and follow up].

Objective: To summarize the clinical data of 15 patients with fibrodysplasia ossificans progressiva (FOP), follow up and analyze the characteristics of the joint involvement in FOP. Method: From May 2005 to December 2016, fifteen FOP cases had been diagnosed in the Children's Hospital Capital Institute of Pediatrics. All medical records and follow-up data were collected and a retrospective analysis was made on the joint involvement in FOP. Pearson correlation analysis was used for data, P<0.05 for the difference was statistically significant. Result: There were 8 males and 7 females in 15 cases. The age of onset was 2(1-6)years. The age at diagnosis was 6 (4-9) years. All cases had hallux valgus deformity and bone mass formation. Twelve cases had joints involvement on enrollment into this study: 8 cervical vertebra, 7 shoulder joint, 5 hip joint, 4 elbow joint, 3 wrist joint, 2 temporomandibular joint, 2 lumbar vertebra. The age of diagnosis and duration of disease were positively correlated with the number of the involved joints (r=0.523, 0.628; P=0.045, 0.012); mild changes were found in joint imaging. Thirteen cases received telephone follow-up, the average duration of follow-up was 6(3-7)years, no change in 11 cases, disease progress in 2 cases. Conclusion: Joint involvement is a common complication of FOP, especially the cervical vertebra.Multiple joints involvement, dominant functional impairment, and mild imaging changes are the characteristics of joint lesions caused by FOP.The number of involved joints gradually increases with increase of age of the patients and the prolonged course of the disease.

[Role of magnetic resonance imaging in the diagnosis of juvenile dermato-myositis and polymyositis in Chinese children].

Objective: To evaluate the utility of magnetic resonance imaging (MRI) in diagnosis of juvenile dermatomyositis and polymyositis (JDM-PM) in children. Method: Fifty-four patients with JDM-PM in the active stage were enrolled in the study group. Twelve patients with benign acute childhood myositis and forty patients with juvenile idiopathic arthritis (JIA) complicated with myositis were enrolled as controls. MRI imaging of thighs was performed in all patients, fast spin echo T1WI, T2WI, and STIR were obtained in all patients.Muscle biopsy was performed in 41/54 patients with JDM-PM. We compared the value of MRI in diagnosis of JDM-PM with muscle biopsy, electromyography and serum aspartate transaminase (AST), alanine transaminase (ALT), creatine kinase (CK), isoenzyme of creatine kinase (CKMB), lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH) levels. Continuous normally distributed variables were reported as means and continuous non-normally distributed variables as median. Chi-square test and Fisher exact test were used to test differences between MRI and other categorical variables. Result: A total of 54 patients were included. Twenty-seven patients were male and the others were female. Average age of the patients was (7.1±3.5) years (2-13 years); 45(83%) paitests were JDM cases and 9(17%) patients had JPM. All patients had MRI examination. Of the 54 patients, 53 had multiple myositis; 10 out of 50 (19%) patients received second MRI after treatment, 6 out of 10 patients had normal findings, 4 patients showed obviously improved images; 41 out of 54 patients underwent muscle biopsy; 22 out of 41 patients had inflammatory cells infiltration and muscle fiber degeneration. The results of the muscle enzyme tests are as follows: 27 (50%) patients had elevated AST, 24 (44%) patients had elevated ALT, 22 (41%) patients had elevated CK, 18(33%) patients had elevated CKMB, and LDH rose in 30 (56%) patients, HBDH rose in 28(52%) patients. These results suggested that muscle MRI was more sensitive than muscle biopsy and muscle enzyme tests in diagnosis of JDM-PM. Conclusion: Patients with JDM-PM showed diffuse patchy hyperintense signals on T2WI of their thighs. MRI may be a sensitive, reliable, and noninvasive tool for clinical diagnosis and theraputic evaluation of JDM-PM.

[The value of brain magnetic resonance imaging in the early diagnosis of neuropsychiatric systemic lupus erythematosus].

OBJECTIVE: To investigate the value of brain magnetic resonance imaging (MRI) in evaluating the intracranial injuries in patients with juvenile onset systemic lupus erythematosus (SLE). METHOD: Data of brain MRI, CT, electroencephalogram (EEG), cerebrospinal fluids analysis and clinical features of the central nervous system of 44 patients from March 2007 to March 2015 with juvenile onset SLE who were not treated with glucocorticoids (Gcs) and immunosuppressive agents (Is) were retrospectively analyzed and compared. RESULT: Twenty-seven out of 44 patients demonstrated abnormal signs on brain MRI, including encephalatrophy, cerebral infarction, demyelination, encephalorrhagia, vertebral arteriostenosis and abnormal signals on the brain diffusion-weighted imaging (DWI). Sixteen patients had clinical features of the central nervous system involvement, fifteen had continuous headache, nine had continuous dizziness, seven had convulsions, three had hemiplegia, one had blurred vision. Physical examination of the nervous system: ten patients had abnormal signs, all had cervical rigidity, five showed pyramidal sign, three showed loss of muscle tone, two with cranial neuropathies and one had paresthesia. EEG: Ten patients showed abnormal waves on EEG, all showed diffused slow-waves, and five showed sharp waves and spikes. Cerebrospinal fluids analysis: six patients had abnormal results, five of them had cell count elevation and one had cell count and protein elevation, while there was glucose and chloride degression. Brain CT: Eight patients received CT scan, two showed cerebral infarction. χ(2) test was used to compare the differences among head MRI, EEG, cerebrospinal fluid analysis, physical examination of the nervous system, clinical features of the nervous system, the difference was significant(χ(2)=12.055, P=0.001; χ(2)=19.627, P=0.001; χ(2)=3.859, P=0.049; χ(2)=12.055, P=0.001). CONCLUSION: Brain MRI may be a better method in early diagnosis of intracranial injuries than CT, EEG, cerebrospinal fluid analysis and physical examination of the nervous system. Patients with juvenile onset SLE should receive brain MRI after diagnosis in order to investigate the intracranial injuries. Abnormal signals on the DWI are the signs of active disease.

Sequence and electrophysiological characterization of two insect-selective excitatory toxins from the venom of the Chinese scorpion Buthus martensi.

The two insecticidal peptides Bm32-VI and Bm33-I, isolated from the venom of the Chinese scorpion Buthus martensi induce paralytical symptoms typical of insect contractive toxins. They show, respectively, 74% and 77% homology with AaIT from Androctonus australis, comparable insecticidal activity and no vertebrate toxicity. Under voltage-clamp conditions, both toxins induced (1) an increased fast Na(+) current, (2) a shift in voltage dependence of Na(+) current activation, (3) the occurrence of a delayed current, and (4) a slow development of a holding current. Increased Na(+) conductance at negative potential values is responsible for axonal hyperexcitability and the contractive paralysis of insect prey.

Purification, characterization, and synthesis of three novel toxins from the Chinese scorpion Buthus martensi, which act on K+ channels.

Three novel toxins belonging to the scorpion K+ channel-inhibitor family were purified to homogeneity from the venom of the Chinese scorpion Buthus martensi. They have been identified according to their molecular mass (3800-4300 Da) and their neurotoxicity in mice and characterized as 37-amino acid peptides. One of them shows 81-87% sequence identity with members of the kaliotoxin group (named BmKTX), whereas the other two, named BmTX1 and BmTX2, show 65-70% identity with toxins of the charybdotoxin group. Their chemical synthesis by the Fmoc methodology allowed us to show that BmKTX, unlike BmTX1 and BmTX2, possesses an amidated C-terminal extremity. Toxicity assays in vivo established that they are lethal neurotoxic agents in mice (LD50s of 40-95 ng per mouse). Those toxins proved to be potent inhibitors of the voltage-gated K+ channels, as they were able to compete with [125I]kaliotoxin for its binding to rat brain synaptosomes (IC50s of 0.05-1 nM) and to block the cloned voltage-gated K+ channel Kv1.3 from rat brain, expressed in Xenopus oocytes (IC50s of 0.6-1.6 nM). BmTX1 and BmTX2 were also shown to compete with [125I]charybdotoxin for its binding to the high-conductance Ca2+-activated K+ channels present on bovine aorta sarcolemmal membranes (IC50s of 0.3-0.6 nM). These new sequences show multipoint mutations when compared to the other related scorpion K+ channel toxins and should prove to be useful probes for studying the diverse family of K+ channels.

Characterization of four toxins from Buthus martensi scorpion venom, which act on apamin-sensitive Ca2+-activated K+ channels.

Four peptidyl inhibitors of the small-conductance Ca2+-activated K+ channels (SK(Ca)) have been isolated from the venom of the Chinese scorpion Buthus martensi. These peptides were identified by screening C18 HPLC fractions of the crude venom by means of mass analysis by matrix-assisted-laser-desorption/ionization time-of-flight mass spectrometry, and toxicological tests in mice. Edman degradation analysis of the purified peptides showed sequences of 28-31 amino acids including 6 cysteine residues. Three of the sequences were similar to the P01 peptides from Androctonus scorpions, showing 76% sequence similarity for the most closely related, named BmP01, and 46% for the other two, named BmP02 and BmP03. Like the P01 peptides, these molecules showed a low toxic activity in mice after intracerebroventricular injection, and competed (K0.5 > 1 microM) with iodinated apamin for binding to its receptor site from rat brain, which has been proved to be the SK(Ca) channels. The fourth toxin was structurally related to the P05/leiurotoxin I toxin family, with 90% similarity, and was named BmP05. This toxin exhibited a high toxic activity with lethal effects in mice. Due to its small representation in the venom [less than 0.01% (by mass)], its biological properties have been assessed on the synthetic analogue of BmP05, which was assembled on a solid phase by means of Fmoc methodology. The synthetic peptide was physicochemically identical to the natural peptide, as shown by comparison of their molecular masses and amino acid compositions, and by their coelution after coinjection on capillary electrophoresis. These results confirmed the primary structure of BmP05 including an amidated C-terminus. Similarly to natural BmP05, synthetic BmP05 produced toxic and lethal effects after intracerebroventricular injection in mice (LD50 = 37 ng), and was able to compete with iodinated apamin for binding to its receptor in rat brain (K0.5 = 20 pM).

Paternity identification in twins with different fathers.

If a female has sexual intercourse with two males at short intervals within the same ovulatory period, superfecundation may occur. This article reports two cases of paternity identification in twins. The results showed that each twin had come from a different father. Thus, great attention should be paid to such a situation when the twin paternity identification is asked for.