Objective:To investigate the clinical manifestation, therapy, and prognosis of Susac syndrome and enhance the understanding of this disease.Methods:A case summary was made.The clinical data of two siblings with Susac syndrome treated at Children′s Medical Center, Peking University First Hospital in January 2024 were summarized.Reported cases of pediatric Susac syndrome were reviewed.Results:The onset of the disease in the two siblings was at the age of 3.00 and 6.75 years, with recurrent headaches, tinnitus, hearing loss and encephalopathy symptoms.Cranial magnetic resonance imaging showed multiple cerebral microbleeding and microinfarction lesions, " snowball like" in the corpus callosum and diffuse white matter edema in the brain.Audiometry revealed sensorineural hearing loss.In one case, ophthalmic fluorescein angiography revealed ischemic changes due to branch retinal artery occlusions.No pathogenic variants were detected in gene testing.This child was diagnosed with Susac syndrome, and the symptoms were improved after treatment with Corticosteroids and Rituximab.No relapse was observed during the 9-month follow-up.A total of 20 pediatric cases of Susac syndrome were retrieved, including 18 reported previously and 2 cases from this study.There were 2 boys and 18 girls, with the age of onset ranging from 2.5 to 17.0 years.The common initial symptoms included headache (19 cases), vertigo and tinnitus or hearing loss (9 cases), and vision impairment or visual field defect (4 cases). The symptoms were improved after immunotherapy.Conclusions:With a low incidence, Susac syndrome is rare in children and difficult to diagnose.There may be a genetic predisposition in such disease.Early diagnosis and immunotherapy can low the relapse and improve the prognosis.

Objective:To investigate the clinical manifestation, therapy, and prognosis of Susac syndrome and enhance the understanding of this disease.Methods:A case summary was made.The clinical data of two siblings with Susac syndrome treated at Children′s Medical Center, Peking University First Hospital in January 2024 were summarized.Reported cases of pediatric Susac syndrome were reviewed.Results:The onset of the disease in the two siblings was at the age of 3.00 and 6.75 years, with recurrent headaches, tinnitus, hearing loss and encephalopathy symptoms.Cranial magnetic resonance imaging showed multiple cerebral microbleeding and microinfarction lesions, " snowball like" in the corpus callosum and diffuse white matter edema in the brain.Audiometry revealed sensorineural hearing loss.In one case, ophthalmic fluorescein angiography revealed ischemic changes due to branch retinal artery occlusions.No pathogenic variants were detected in gene testing.This child was diagnosed with Susac syndrome, and the symptoms were improved after treatment with Corticosteroids and Rituximab.No relapse was observed during the 9-month follow-up.A total of 20 pediatric cases of Susac syndrome were retrieved, including 18 reported previously and 2 cases from this study.There were 2 boys and 18 girls, with the age of onset ranging from 2.5 to 17.0 years.The common initial symptoms included headache (19 cases), vertigo and tinnitus or hearing loss (9 cases), and vision impairment or visual field defect (4 cases). The symptoms were improved after immunotherapy.Conclusions:With a low incidence, Susac syndrome is rare in children and difficult to diagnose.There may be a genetic predisposition in such disease.Early diagnosis and immunotherapy can low the relapse and improve the prognosis.

Humans ; Infant, Newborn ; Intensive Care Units, Neonatal ; Logistic Models ; Phenotype ; Risk Factors

Objective To explore the classic MRI appearance of secondary hemochromatosis (SHC)related liver iron overload, and the feasibility of quantitative evaluation of liver iron overload by iterative decomposition of water and fat with echo asymmetry and leastGsquares estimationGiron quantification (IDEALGIQ).Methods 20 patients with SHCGrelated liver iron overload (experimental group)and 20 healthy adults (control group)underwent routine liver MRI and IDEALGIQ.The MRI images were comparatively analyzed to assess the hallmark of liver iron overload.In both two groups,the R2 ? values were measured on R2 ? maps,which were generated by IDEALGIQ,then the differences in age,gender and R2 ? value between two groups were comparatively analyzed.In experimental group,the serum ferritin (SF)was detected,and a correlation analysis was tested with R2 ? value.Results For all of the 20 patients, there was signal drop of liver parenchyma on T1 and T2 Gweighted images,signal loss with susceptibility artifact on DWI images,and signal dropped on inGphase images relative to outGofGphase images.Among the 20 patients,18 cases appeared "a dark liver parenchyma"on T2 G weighted images,and the spleen signal in 3 cases was similar to liver parenchyma’s hallmark.The R2 ? values in experimental group and control group were 395.58±255.75 Hz and 41.18±7.86 Hz (t＝－6.12,P＝0.00),respectively.No significant differences between two groups were found in gender and age (χ2＝0.10,P＝0.10 and t＝0.09,P＝0.93).The liver iron overload R2? value was not correlated with SF (r＝0.1 5 3 , P＝0.15).Conclusion On MRI,the typical appearance of liver iron overload is hypointense on T1 and T2Gweighted images,especially"a dark liver parenchyma"on T2 WI,signal drops on inGphase images relative to outGofGphase images,and signal loss with susceptibility artifact on DWI images.R2 ? value of IDEALGIQ can quantitatively evaluate the liver iron overload,without a correlation with SF.

A novel protein encoded by the open reading frame 4 (ORF4) was recently discovered in porcine circovirus type 2 (PCV2). However, little is known about the interaction proteins of ORF4 which hindered better understanding the biological functions of ORF4 in the life cycle of PCV2. In the present study, the ORF4 was inserted into the multiple cloning site of pCMV-N-Flag-GST, yielding recombinant plasmid pCMV-N-Flag-GST-ORF4. The recombinant plasmid was transfected into 293T cells and the intracellular interaction complex of ORF4 were enriched and separated by GST pull-down and SDS-PAGE, sequentially. The potential interacting proteins of PCV2 ORF4 were stained with silver and identified by mass spectrometry (MS). Finally, five candidate ORF4-interacting proteins, including Serine/threonine-protein phosphatase 6 catalytic subunit, alpha cardiac muscle 1, actin, SEC14-like protein 5 and myosin 9 were identified. These results would benefit a better understanding of the biological function of ORF4 in PCV2 infected cells.
Animals ; Circoviridae Infections ; Circovirus ; HEK293 Cells ; Humans ; Mass Spectrometry ; Open Reading Frames ; Swine ; Viral Proteins

Objective: Analyze the changes of indicator of antimicrobial usage and detection rate of multidrug-resistant gram-negative bacteria (MDR-GNB), in order to evaluate the impact of antimicrobial stewardship program (ASP). Methods: The antimicrobial stewardship program was implemented since December 2011 at the Second Affiliated Hospital and Yuying Children′s Hospital of Wenzhou Medical University. Intensified effort was made from 2014 to 2017. We divided the program into four stages, one before ASP (2010-2011) and three after ASP (2012-2013 as the first, 2014-2015 as the second and 2016-2017 as the third post-ASP stages). The usage rates in outpatient,emergency department and inpatient, along with the antibiotic use density (AUD, defined as daily doses/per 100 patient-days), the AUD of the third-generation cephalosporins and carbapenems in inpatient were reviewed retrospectively. The detection rates of extended-spectrum β-lactamases (ESBLs)-producing Escherichia coli, ESBLs-producing Klebsiella pneumonia, carbapenem-resistant E. coli, carbapenem-resistant Klebsiella pneumonia, carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant Pseudomonas aeruginosa were also analyzed at the same time. The correlation analysis between the detection rate of MDR-GNB and the indicator of antimicrobial usage was made. Result: Among four stages, the usage rates were 55.2% (560 578/1 015 540) , 38.1% (493 554/1 296 336) , 26.8% (378 602/1 411 595) and 23.1% (347 817/1 502 817) in outpatient, 75.6% (429 582/568 230) , 61.4% (382 558/623 138) , 43.6% (265 102/608 071) and 35.1% (218 484/622 397) in emergency department, and 76.0% (30 568/40 221) , 53.7% (30 437/56 636) , 49.9% (37 395/74 895) and 50.3% (35 493/70 544) in inpatient, respectively. All indicators decreased significantly (χ²=297 811.798, 3 155 704.783, 5 592.037, P<0.01). The AUD in inpatient was 38.4,31.8,21.7 and 19.41,and the AUD of the third-generation cephalosporins were 13.83, 11.21, 6.20 and 6.84, respectively, which decreased significantly after ASP (r=-0.878, -0.781, P<0.05). The AUD of carbapenems were 1.94,1.77,1.87 and 1.93, respectively (r=0.123, P>0.05). A total of 11 289 strains of bacteria were collected, including 5 589 strains of E. coli, 2 823 strains of K.pneumoniae, 1 637 strains of A. baumandii, and 1 240 strains of P. aeruginosa.The detection rates of ESBLs-producing E.coli and ESBLs -producing K. pneumoniae in four stages were 75.4% (1 034/1 371) , 66.6% (893/1 341) , 57.8% (834/1 443) , 46.7% (670/1 434) and 78.7% (547/695) , 67.5% (455/674) , 49.3% (421/854) , 32.5% (195/600) , respectively,both decreased significantly (χ²=266.204; 328.805, P<0.01). The detection rates of Carbapenem-resistant A. baumannii were 28.2% (115/408) , 26.7% (126/472) , 24.3% (125/515) and 12.0% (29/242) respectively,and showed significant decreasing trend after ASP (χ²=18.112, P<0.01). The detection rates of carbapenem-resistant P. aeruginosa were 11.3% (40/355) , 18.5% (58/313) , 13.4% (46/343) and 7.0% (16/229) , respectively,with the most obvious decrease in the third stage after ASP. The detection rates of carbapenem-resistant E. coli and carbapenem-resistant K. pneumonia were continuously lower (<5%). There were positive correlations between the detection rates of ESBLs-producing E. coli and K. pneumoniae and all usage indicators (r₁=0.930, 0.974, 0.746, 0.958, 0.842; r₂=0.910, 0.960, 0.765, 0.963, 0.898, P<0.05). Conclusion The antimicrobial stewardship program can effectively reduce both the usage of antimicrobial and the production of MDR-GNB, which has great value to promote rational clinical use of antimicrobials and reduce bacterial resistance.

Objective Analyze the changes of indicator of antimicrobial usage and detection rate of multidrug‐resistant gram‐negative bacteria (MDR‐GNB), in order to evaluate the impact of antimicrobial stewardship program (ASP). Methods The antimicrobial stewardship program was implemented since December 2011 at the Second Affiliated Hospital and Yuying Children′s Hospital of Wenzhou Medical University. Intensified effort was made from 2014 to 2017. We divided the program into four stages, one before ASP (2010-2011) and three after ASP (2012-2013 as the first, 2014-2015 as the second and 2016-2017 as the third post‐ASP stages). The usage rates in outpatient,emergency department and inpatient, along with the antibiotic use density (AUD, defined as daily doses/per 100 patient‐days), the AUD of the third‐generation cephalosporins and carbapenems in inpatient were reviewed retrospectively. The detection rates of extended‐spectrum β‐lactamases (ESBLs)‐producing Escherichia coli , ESBLs‐producing Klebsiella pneumonia , carbapenem‐resistant E. coli , carbapenem‐resistant Klebsiella pneumonia , carbapenem‐resistant Acinetobacter baumannii and carbapenem‐resistant Pseudomonas aeruginosa were also analyzed at the same time. The correlation analysis between the detection rate of MDR‐GNB and the indicator of antimicrobial usage was made. Result Among four stages, the usage rates were 55.2%(560 578/1 015 540), 38.1% (493 554/1 296 336), 26.8%(378 602/1 411 595) and 23.1%(347 817/1 502 817)in outpatient, 75.6% (429 582/568 230), 61.4%(382 558/623 138), 43.6%(265 102/608 071) and 35.1%(218 484/622 397) in emergency department, and 76.0%(30 568/40 221), 53.7%(30 437/56 636), 49.9%(37 395/74 895) and 50.3%(35 493/70 544) in inpatient,respectively. All indicators decreased significantly(χ2=297 811.798, 3 155 704.783, 5 592.037, P<0.01). The AUD in inpatient was 38.4,31.8,21.7 and 19.41,and the AUD of the third‐generation cephalosporins were 13.83, 11.21, 6.20 and 6.84, respectively, which decreased significantly after ASP (r=-0.878,-0.781, P<0.05). The AUD of carbapenems were 1.94,1.77,1.87 and 1.93, respectively (r=0.123, P>0.05). A total of 11 289 strains of bacteria were collected, including 5 589 strains of E. coli , 2 823 strains of K. pneumoniae , 1 637 strains of A. baumandii , and 1 240 strains of P. aeruginosa . The detection rates of ESBLs‐producing E. coli and ESBLs‐producing K. pneumoniae in four stages were 75.4%(1 034/1 371), 66.6%(893/1 341), 57.8%(834/1 443), 46.7% (670/1 434) and 78.7% (547/695), 67.5%(455/674), 49.3%(421/854), 32.5%(195/600), respectively,both decreased significantly (χ2=266.204;328.805, P<0.01). The detection rates of Carbapenem‐resistant A. baumannii were 28.2%(115/408), 26.7%(126/472), 24.3%(125/515) and 12.0%(29/242) respectively,and showed significant decreasing trend after ASP (χ2=18.112, P<0.01). The detection rates of carbapenem‐resistant P. aeruginosa were 11.3%(40/355), 18.5%(58/313), 13.4%(46/343) and 7.0%(16/229), respectively,with the most obvious decrease in the third stage after ASP. The detection rates of carbapenem‐resistant E. coli and carbapenem‐resistant K. pneumonia were continuously lower (<5%). There were positive correlations between the detection rates of ESBLs‐producing E. coli and K. pneumoniae and all usage indicators ( r 1=0.930, 0.974, 0.746, 0.958, 0.842;r2=0.910, 0.960, 0.765, 0.963, 0.898,P<0.05). Conclusion The antimicrobial stewardship program can effectively reduce both the usage of antimicrobial and the production of MDR‐GNB, which has great value to promote rational clinical use of antimicrobials and reduce bacterial resistance.

Objective To evaluate the clinical characterisitics of polyarteritis nodosa (PAN) patients with acromelic gangrene,and to improve the understanding of this disease by clinicians.Methods The clinical and laboratory data of PAN patients with acromelic gangrene admitted to Peking Union Medical College Hospital (PUMCH) between November 1986 to October 2016 were collected and summarized.According to the ratio of 1∶2,PAN patients without acromelic gangrene during the same period were randomly selected and compared with patients with acromelic gangrene.The comparison of the demographic data,system involvement,laboratory and other auxiliary examination results,the treatment were included in this study.All data were analyzed by SPSS 19.0 statistical software.T test,Mann Whitney U test,x2 test were used for statistical analyses.Results Among 204 PAN patients admitted to PUMCH during this period,22 cases were complicated with gangrenes.In PAN patients with gangrenes,-male/female ratio was 4.5/1,the mean age was (43±19) years,and the disease duration (from onset of disease to gangrene) was 3.5 months (ranged from 1 week to 20 years).Simple finger gangrenes occurred in 7 cases(32％),simple toe gangrenes in 8 cases (36％),both gangrenes in 7 cases (32％).In the involvements of limb arteries,15 cases (68％) were posterior tibial artery involvement,12 cases (55％) were anterior tibial artery involvement,10 cases (45％) were radial artery involvement,7 cases (32％) were ulnar artery involvement,5 cases (23％) were peroneal artery involvement,5 cases (23％) were superficial femoral artery involvement,4 cases (18％) were dorsal foot artery involvement,3 cases (14％) were popliteal artery involvement,1 case (5％) was anterior interosseous artery involvement.There were significant difference in PAN patients with and without acromelic gangrene as patients with acromelic gangrene were more prone to arthritis/pain (45％ vs 2％;x2=16.71,P＜0.01),new-onset hypertension (41％ vs 7％;x2=9.28,P＜0.01),intestinal bleeding/perforation (41％ vs 14％;x2=6.21,P=0.01),increased eosinophils (55％ vs 7％;x2=19.02,P＜0.01),artery (91％ vs 27％;x2=23.78,P＜0.01) involvement in extremities,head and neck (41％ vs 18％;x2=3.96,P=0.05),arteriovenous thrombosis (27％ vs 2％;x2=7.21,P=0.007),glucocorticoid pulse therapy (73％ vs 14％;x2=23.05,P＜0.01).Conclusion PAN patients with acromelic gangrene have significant increase of eosinophils and widespread internal organ ischemia.Aggressive treatment should be taken in these patients.

Objective: To analyze the hotspots of known pathogenic disease-causing variants of glucose-6-phosphate dehydrogenase (G6PD) and the phenotype spectrum of neonatal patients with known pathogenic disease-causing variants of G6PD. Methods: The known pathogenic disease-causing variants of G6PD were collected from Human Gene Mutation Database. Screening was performed for these variants among the 7 966 cases (2 357 neonatal, 5 609 non-neonatal) in the database of sequencing at Molecular Diagnosis Center, Children's Hospital of Fudan University. All these samples were from patients suspected with genetic disorder. The database contained Whole Exon Sequencing data and Clinical Exon Sequencing data. We screened out the patients with known pathogenic disease-causing variants of G6PD, analyzed the hotspot of G6PD and the phenotype spectrum of neonatal patients with known pathogenic disease-causing variants of G6PD. Results: (1) Among the next generation sequencing data of the 7 966 samples, 86 samples (1.1%) were detected as positive for the known pathogenic disease-causing variants of G6PD (positive samples set). In the positive sample set, 51 patients (33 males, 18 females) were newborn babies. Forty-three patients (26 males, 17 females) had the enzyme activity data of G6PD. (2) Among the 86 samples, Arg463His, Arg459Leu, Leu342Phe, Val291Met were the leading 4 disease-causing variants found in 72 samples (84%). (3) Male neonatal patients with the same variants had the statistically significant differences in enzyme activity: among 13 patients with Arg463His, enzyme activity of 9 patients was ranked as grade Ⅲ, 1 case ranked as Ⅳ, 3 cases had no activity data;among 10 patients with Arg459Leu, enzyme activity of 4 patients was ranked as Ⅱ, 4 cases ranked as Ⅲ, 2 cases had no activity data;among 2 patients with His32Arg, enzyme activity of one patient was ranked as Ⅱ, another was Ⅲ. Male neonatal patients with the same mutation and enzyme activity also had the statistically significant differences in phenotype spectrum: among 9 patients with Arg463His and level Ⅲ enzyme activity, 6 presented hyperbilirubinemia, 2 met the criteria for exchange transfusion therapy, 2 showed hemolysis;among 4 patients with Arg459Leu and level Ⅱ enzyme activity, 3 presented hyperbilirubinemia;among 4 patients with Arg459Leu and level Ⅲ enzyme activity, 2 presented hyperbilirubinemia, 1 met the standard of exchange transfusion therapy;among 3 patients with Val291Met and level Ⅲ enzyme activity, 1 presented hyperbilirubinemia. Conclusions Arg463His, Arg459Leu, Leu342Phe, Val291Met were the hotspots variants for the G6PD. Patients with the same G6PD variants and sex present different phenotype, patients with the same G6PD variants, sex and enzyme activity also present different phenotype .