[Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in 13 children]

Objective: To analyze the clinical characteristics, treatment and prognosis of Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in children. Methods: A retrospective analysis was performed on the clinical features, laboratory tests, neuroelectrophysiological examination, imaging, treatment and outcomes of 13 patients with Hashimoto's encephalopathy presenting with isolated cerebellar ataxia, who were admitted to the Department of Pediatric Neurology of Guangzhou Women and Children's Medical Center from January 2016 to May 2021. Results: Among the 13 cases, 6 were males and 7 were females. The onset age was 2.6 (2.0,3.3) years, 9 children had precursor infection or vaccination before the first course of disease. All the 13 children had gait abnormalities or unsteady sitting, 10 had intentional tremor, 6 had dysarthria, 3 had body tremor, 2 had nystagmus, 3 had fatigue, 3 had hypotonia, 2 had vomiting and 1 had irritability. Thyroglobulin antibody (TgAb) was 500.0 (298.9,587.2) kU/L and thyroid peroxidase antibody (TPOAb) was 621.9 (449.6,869.4) kU/L in 13 cases. Autoantibodies were positive in 9 cases, and cerebrospinal fluid leukocytosis was seen in 4 cases. Regarding electroencephalography result, 4 cases had background slowing and 1 case had occasional sharp waves. Among the 3 patients who had relapses, 1 had cerebellar atrophy shown on cranial magnetic resonance imaging (MRI) during the recurrence. All the patients received intravenous immunoglobulin (IVIG) and intensive methylprednisolone therapy during the first onset, followed by the disappearance of the symptoms, 1 patient had repeated episodes which was decreased after immunosuppressive treatment with Rituximab.Followed up for 25.0 (22.5,33.3) months after the last episode, 12 achieved complete remission and 1 had a wide base gait. Conclusions: Trunk ataxia is the common symptom of Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in children.Children with cerebellar ataxia should be tested for TgAb and TPOAb to detect Hashimoto's encephalopathy, avoiding missed diagnosis and treatment delays; IVIG and intensive steroid therapy is effective, and immunosuppressive therapy for patients with multiple relapses could reduce the recurrence.

Detection of blaKPC and blaNDM genes by duplex PCR with lateral flow dipsticks from sterile body fluid samples

Duplex polymerase chain reaction with lateral flow dipsticks (duplex PCR-LFD) was developed for the simultaneous detection of beta-lactamase Klebsiella pneumoniae carbapenemase (bla_KPC ) and beta-lactamase New Dehli metallo-beta-lactamase (bla_NDM ) genes in body fluid samples. This method was validated using well-characterized isolates. The assessment of the specificity of duplex PCR-LFD showed that there was no cross-reactivity with other targets. The detection limit of the duplex PCR-LFD assay was 20 CFU per ml for bla_KPC and bla_NDM . Among 177 sterile body fluid samples tested by the duplex PCR-LFD assay, 40 were bla_KPC -positive and five were bla_NDM -positive. The results obtained from 122 corresponding Gram-negative bacteria which were isolated from these clinical samples and tested by duplex PCR-LFD assay showed that there were 37 strains carrying bla_KPC genes in 40 bla_KPC -positive samples and three strains carrying bla_NDM genes in five bla_NDM -positive samples. Statistical analysis indicated that there was no significant difference between the direct detection of bla_KPC and bla_NDM genes in clinical sterile body fluid samples and their corresponding clinical isolates. Therefore, duplex PCR-LFD can be effective for the simultaneous detection of bla_KPC and bla_NDM in clinical isolates and directly from clinical samples, which may be helpful for the administration of appropriate antimicrobial treatment.

[Investigation of occupational hazard of 750 kV extra high voltage substations]

Objective: To understand the current status of major occupational hazards in 750 kV extra high voltage (EHV) substations. Methods: In July 2019, through investigating and detecting the sulfur hexafluoride, power frequency electric field and noise occupational hazards of 750 kV EHV substations in substation 1, substation 2, substation 3, substation 4, substation 5, substation 6 and substation 7, the exposure intensity of the sulfur hexafluoride, power frequency electric field and noise intensity that the operators are exposed to during the inspection process were analyzed. Results: The qualified rate of 358 sulfur hexafluoride test results was 100.0% of the seven 750 kV EHV substations. The qualified rate of 8 h time-weighted average of the power frequency electric field of those 750 kV EHV substations contacted by operators was 100.0%. Among the 847 power frequency electric field detection points, the exceeding standard rate of power frequency electric field was 64.3%, and the differences in the power frequency electric field detection exceeding standard rates of different substations and inspection areas were statistically significant (χ²=87.52, 50.86, P<0.01) . The highest exceeding standard rate of power frequency electric field was the circuit breaker inspection area (94.4%, 34/36) . The noise intensity test results of the seven EHV substations were 41.1-79.7 dB (A) , and the qualified rate was 100.0%. Conclusion: The sulfur hexafluoride, power frequency electric field and noise that the operators contacted in 750 kV EHV substations meet the requirements of occupational exposure limits. The inspection areas of main transformers, capacitors, reactors, bus bars and switches have high power frequency electric field radiation, should be select equipment iand give priority to robot inspection, and reasonably adjust the inspection time to reduce the intensity level of substation operators' exposure to power frequency electric field.

[Hesitancy of parents towards vaccines in national immunization program in three regions in China: a cross-sectional study]

Objective: To investigate the incidence and determinants of vaccine hesitancy towards national immunization program in China and understand the current status of parents' hesitancy to different vaccines used in national immunization program. Methods: A cross-sectional survey was conducted in Beijing, Sichuan and Gansu. The methods of proportional probability sampling and convenience sampling were used to select the eligible study subjects for questionnaire surveys. Results: A total of 3 592 parents were enrolled in the study, in whom 38.22% fully accepted all the vaccines, 59.35% agreed to let their children to receive all the vaccines but showed slight concern, and 2.42% had hesitancy to the vaccines. The vaccine with the most hesitancy was polio vaccine (0.89%), followed by diphtheria pertussis tetanus vaccine (0.70%) and hepatitis A vaccine (0.64%). The dominant reason for vaccine hesitancy was the risk-benefit perception of vaccination (31.03%), followed by the low awareness of the parents (21.84%) and the inconvenience caused by distance and time (21.84%). Conclusions: The incidence of vaccine hesitancy towards national immunization program was low in parents in China, but over 50% of the parents showed concern to the vaccines. It is essential to improve the service quality of national immunization program and strengthen the health education about the vaccination to reduce the incidence of vaccine hesitancy in parents.

A Review on Phytochemicals of the Genus Maytenus and Their Bioactive Studies

The genus Maytenus is a member of the Celastraceae family, of which several species have long been used in traditional medicine. Between 1976 and 2021, nearly 270 new compounds have been isolated and elucidated from the genus Maytenus. Among these, maytansine and its homologues are extremely rare in nature. Owing to its unique skeleton and remarkable bioactivities, maytansine has attracted many synthetic endeavors in order to construct its core structure. In this paper, the current status of the past 45 years of research on Maytenus, with respect to its chemical and biological activities are discussed. The chemical research includes its structural classification into triterpenoids, sesquiterpenes and alkaloids, along with several chemical synthesis methods of maytansine or maytansine fragments. The biological activity research includes activities, such as anti-tumor, anti-bacterial and anti-inflammatory activities, as well as HIV inhibition, which can provide a theoretical basis for the better development and utilization of the Maytenus.

[Determination of hydrazine in workplace air by gas chromatography with large bore capillary column]

Objective: To determine hydrazine quantitatively in workplace air by gas chromatography with large bore capillary column. Methods: In October 2019, hydrazine in the air was adsorbed by acid silica gel tube sampling and desorped using sulfuric acid solution. After derivatization with furfural and extraction, the content of hydrazine was determined by DM-FFAP capillary column gas chromatography with flame ionization detector. Results: The linear regression equation was y=353.8x+21.2 (r=0.9998) between 0.1-2.0 μg/ml of target concentration. The detection limit was 0.030 μg/ml. The lower limit of quantification was 0.100 μg/ml. If 15 L air sample was collected, the minimum detection concentration was 0.004 mg/m(3) and the minimum quantitative concentration was 0.013 mg/m(3) respectively. The average desorption efficiency was 86.5%-89.4%. The recovery was 94.4%-97.1%. The relative standard deviation was 1.6%-4.9%. Hydrazine and furfural derivative was 2-furaldehyde hydrazine. Conclusion: The method has symmetrical peak shape of hydrazine derivatives chromatographic peaks, short analysis time, easy operation, and is suitable for the determination of the concentration of hydrazine in the air in the workplace.

[Application of pulse contour cardiac output monitoring technology in fluid resuscitation of severe burn patients in shock period]

Objective: To investigate the application of pulse contour cardiac output (PiCCO) monitoring technology in fluid resuscitation of severe burn patients in shock period. Methods: From January 2015 to December 2019, 33 patients with severe burns who were hospitalized in Guangzhou Red Cross Hospital, meeting the inclusion criteria, were recruited into a retrospective cohort study with their clinical information collected. The patients were divided into PiCCO monitoring group with 15 cases (13 males and 2 females, aged (43±13) years) and routine monitoring group with 18 cases (14 males and 4 females, aged (39±9) years) according to the monitoring method used. After admission, all the patients were rehydrated following the rehydration formula of the Third Military Medical University for shock period. In routine monitoring group, the fluid resuscitation of patients was performed by monitoring indicators such as urine volume and blood pressure, while PiCCO monitoring was performed among patients in PiCCO monitoring group, and their fluid resuscitation was guided by the patient's condition and the hemodynamic parameters (without pursuing normal levels of the parameters) of PiCCO monitoring on the basis of normal monitoring indicators in routine monitoring group. The colloids coefficients, the electrolyte coefficients (compared with the corresponding rehydration formula value of 0.75 mL·kg(-1)·% total body surface area (TBSA)(-1) of the Third Military Medical University for shock period during the first 24 h post injury), the total rehydration coefficients, and the urine volumes during the first and second 24 h post injury, the lactic acid level, the base excess level, and the oxygenation index at admission and 24, 48 h after admission, and the mechanical ventilation time, the wound healing time, and the death ratio of patients in the two groups were recorded. The cardiac index, the global end-diastolic volume index (GEDVI), the intrathoracic blood volume index (ITBVI), the extravascular lung water index (EVLWI), and the systemic vascular resistance index (SVRI) of patients in PiCCO monitoring group at post injury hour 24, 48, and 72 and the abnormal cases were recorded. Data were statistically analyzed with Fisher's exact probability test, independent-sample or one-sample t test, analysis of variance for repeated measurement, and Bonferroni correction. Results: During the first 24 h post injury, the colloids coefficients of patients in PiCCO monitoring group was (0.69±0.15) mL·kg(-1)·%TBSA(-1), which was significantly less than (0.85±0.16) mL·kg(-1)·%TBSA(-1) in routine monitoring group (t=-2.612, P<0.05). Compared with the rehydration formula value of the Third Military Medical University for shock period, only the colloids coefficient of patients in routine monitoring group during the first 24 h post injury was significantly increased (t=2.847, P<0.05). There were no statistically significant differences between the two groups in the colloids coefficients of patients during the second 24 h post injury, or the electrolyte coefficients, the total rehydration coefficients, the urine volumes of patients during the first and the second 24 h post injury (t=0.579, -0.011, 0.417, -1.321, -0.137, 0.031, 1.348, P>0.05). The lactic acid level, the base excess level, the oxygenation index of patients at admission and 48 h after admission, and the oxygenation index of patients at 24 h after admission between the two groups were similar (t=-1.837, 0.620, 0.292, -1.792, 1.912, -0.167, 1.695, P>0.05). The levels of lactic acid and base excess of patients in PiCCO monitoring group were (4.8±1.4) and (1.2±5.5)mmol/L, respectively, which were significantly better than (7.0±1.5) and (-2.8±3.0) mmol/L in routine monitoring group at 24 h after admission (t=-3.904, 2.562, P<0.05 or P<0.01). There were no statistically significant differences between the two groups in the mechanical ventilation time or the wound healing time of patients (t=-0.699, -0.697, P>0.05), or the death ratio of patients (P>0.05). In PiCCO monitoring group, the GEDVI, and the ITBVI of patients were lower than the normal low values at post injury hour 24 and 48, which were in the normal range at post injury hour 72; the cardiac index of patients increased gradually and recovered to normal at post injury hour 48; the SVRI of patients increased significantly at post injury hour 24 and then gradually decreased to normal; the EVLWI average of patients at all time points post injury were less than 10 mL/kg. At post injury hour 24, most of the hemodynamic parameters of more than or equal to 8/15 patients in PiCCO monitoring group were abnormal, and the abnormal proportion decreased later. Conclusions: On the basis of traditional monitoring indicators, the use of PiCCO monitoring technology combined with the patient's condition (without pursuing normal levels of the parameters) in guiding the fluid resuscitation in severe burn patients can reduce the usage of colloid and better improve tissue perfusion, with the resuscitation effect being better than conventional monitoring.

Synthesis and characterization of an anti-caries and remineralizing fluorine-containing cationic polymer PHMB-F

Dental caries have become a major global public health problem. Plaque control and remineralization of initial enamel lesions are paramount for the prevention and control of caries. Polyhexamethylene biguanide (PHMB) is a type of cationic amphipathic antibacterial agent with broad-spectrum antibacterial properties and good biological safety. Fluoride delays demineralization and promotes the remineralization of hard dental tissues. However, a high concentration is needed for it to function as an antibacterial agent. In order to create a PHMB with the benefits associated with fluoride, we synthesized a fluorine-containing cationic polymer, PHMB-F. Fourier transform-infrared spectroscopy and solid state nuclear magnetic resonance characterization confirmed the successful synthesis of PHMB-F. Antibacterial tests showed that PHMB-F had better antiseptic efficacy for Streptococcus mutans compared with just PHMB. Moreover, positively-charged PHMB-F allows fluoride ions to exist closer to the enamel surface with negative potential, which markedly lowers the ion concentrations in the microenvironment adjacent to hard dental tissues needed to maintain equilibrium. Thus, only low concentrations of PHMB-F are required for enamel remineralization.

[Short-term outcomes of single incision plus one port laparoscopic surgery for colorectal cancer]

Objective: Although single port laparoscopic surgery has achieved good clinical results, many surgeons are discouraged by the difficulties of operation, conflict of instruments, lack of antagonistic traction, and straight-line perspective. Therefore, some surgeons have proposed a single incision plus one hole laparoscopic surgery (SILS+1) surgical method. This study explored the safety and feasibility of SILS+1 for radical resection of colorectal cancer. Methods: A descriptive cohort study was carried out. The clinical data, including the operation, pathology and recovery situation, of 178 patients with colorectal cancer undergoing SILS+1 at Department of General Surgery, Nanfang Hospital, Southern Medical University from March 2018 to January 2019 were prospectively collected and retrospectively analyzed. Clavien-Dindo criteria was used for postoperative complication evaluation and visual analog scale was used for pain standard. Follow-up studies were conducted through outpatient service or telephone and the follow-up period was up to May 2019. Results: A total of 178 patients with colorectal cancer underwent SILS+1, including 111 male patients (62.4%) with an average age of 59 years. Eleven (6.2%) patients received added 1-3 operation ports during operation, and 1 patient was converted to open surgery due to ileocolic artery hemorrhage. The operative time was (135.2±42.3) minutes. The intraoperative blood loss was (34.6±35.5) ml. The number of harvested lymph nodes was 33.1±17.6. The distal margin was (4.7±17.8) cm. The proximal margin was (10.2±5.3) cm. Operation-related complications were observed in 16 patients (9.0%) within 30 days after the operation, of whom 6 had Clavien-Dindo III complications (3.4%). The postoperative pain scores were lower than 3. The average postoperative hospital stay was (5.6±2.6) days. Three patients (1.7%) returned to hospital within 30 days after operation due to intestinal obstruction and infection around stoma. The cosmetic evaluation of all the patients was basically satisfied. Conclusion: SILS+1 is safe and feasible in the treatment of colorectal cancer, and can reduce the postoperative pain.

Burden of colorectal cancer attributable to diet low in milk in China, 1990-2017: findings from the global burden of disease study 2017

BACKGROUND

Colorectal cancer (CRC) has emerged as a major public health concern. However, little is known about the burden attributable to specific risk factors. The present study aimed to estimate the temporal trends and geographical variation of CRC burden attributable to a diet low in milk in China.

METHODS

Following the general analytic strategy used in the 2017 Global Burden of Disease study, we assessed the age-, sex-, and province-specific mortality and disability-adjusted life-years (DALYs) of CRC caused by a diet low in milk in China from 1990 to 2017.

RESULTS

In 2017, a diet low in milk contributed 32 032 [95% uncertainty interval (UI) = 11 350-53 806] deaths and 726 710 (95% UI = 256 651-1 218 153) DALYs for CRC with a population attributable fraction of 17.1%. The age-standardised mortality and DALY rates per 100 000 were 1.7 (95% UI = 0.6-2.9) and 36.8 (95% UI = 13.0-61.7), respectively. An upward trend with age in rates of mortality and DALYs was observed. Males had higher age-standardised rates than females. The number of deaths and DALYs increased significantly from 1990 to 2017, whereas the corresponding age-standardised rates showed relatively stable trends. In 2017, Hunan and Liaoning were ranked as the top two provinces in terms of disease burden. Socio-demographic index had a weak correlation with the age-standardised mortality (r = 0.348, P = 0.047).

CONCLUSIONS

The present study shows a substantial increase in the CRC burden attributable to a diet low in milk over the past three decades. Greater priority in CRC prevention should be given to males and the elderly population throughout China, particularly in less-developed provinces.

[Evaluation of drug-drug interactions between yimitasvir phosphate capsules with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets]

Objective: To evaluate the drug-drug interactions and the tolerability of combined medication between yimitasvir phosphate capsules with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets in healthy volunteers. Methods: A randomized, open, and continuous administration design was used in trial 1 (yimitasvir phosphate capsules with sofosbuvir tablets). 28 subjects were randomly divided into two groups. A non-randomized, open design was used in trial 2 (yimitasvir phosphate capsules with omeprazole magnesium enteric-coated tablets), and included 42 subjects divided into three groups. The open design method was used in trial 3 (yimitasvir phosphate capsules with rosuvastatin calcium tablets), and included 14 subjects. The plasma concentrations of yimitasvir phosphate, sofosbuvir and their main metabolites GS-331007, omeprazole and rosuvastatin were validated by a liquid chromatography/tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated by Phoenix winNonlin software. Results: (1) in trial 1, after single and co-administration, the 90% CI of sofosbuvir C(max) and AUC(0-tau) geometric mean ratio (GMR) were 152.0% (118.0% ~ 197.0%) and 230.0% (184.0% ~ 287.0%), with an increase of 52.0% and 130.0% compared to single dose of sofosbuvir, respectively. The 90% CI of GS-331007 C(max) GMR was 74.0% (67.5% ~ 81.2%) and reduced by 26% compared to single dose of sofosbuvir. (2) in trial 2, the 90% CI of C(max) GMR after yimitasvir single or co-administration at the same time, with a 4-hours interval, or with a 12- hours interval were 68.9% (44.5% ~ 106.7%) , 64.0% (43.8% ~ 93.6%) and 56.4%(38.9% ~ 81.9%), and the 90% CI of AUC(0-t) GMR were 68.6% (46.5% ~ 101.2%), 68.3% (47.6% ~ 98.0%) and 60.5% (41.8% ~ 87.5%), respectively. Compared with single dose of yimitasvir, the C(max) and AUC(0-t) were decreased by 31.1% and 31.4%, 36.0% and 31.7%, 43.6% and 39.5%, respectively. (3) In trial 3, after single and co-administration, the 90% CI of rosuvastatin C(max) and AUC(0-72) GMR were 172.4% (153.6% ~ 193.5%) and 158.0% (144.3% ~ 172.9%), respectively, with an increase of 74.9% and 60.5% compared to single dose of rosuvastatin. There were no serious adverse events and adverse events leading to withdrawal from the trial. Conclusion: Yimitasvir phosphate capsules have drug-drug interactions with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets.

MRI findings of central nervous system involvement in children with haemophagocytic lymphohistiocytosis: correlation with clinical biochemical tests

AIM

To investigate the brain magnetic resonance imaging (MRI) features of children with haemophagocytic lymphohistiocytosis (HLH) with central nervous system (CNS) involvement, and to investigate the correlation with clinical biochemical tests.

MATERIAL AND METHODS

Clinical and MRI data were collected from 118 children with HLH-CNS between January 2012 and June 2019. Patients were grouped according to their MRI findings, and statistical methods were used to test for correlations between the MRI findings and biochemical variables.

RESULTS

Patients were divided into three groups, including normal appearance (Group 1, 17/118), diffuse parenchymal volume loss (Group 2, 44/118), and brain parenchyma lesions (Group 3, 57/118) containing three subtypes of brain lesions and HLH-CNS complications. Comparing biochemical values among the three groups revealed a significant difference for all values (p<0.05), except for cell counts in the cerebrospinal fluid (CSF). A pairwise comparison further showed significant inter-group differences for most of the variables. Spearman's rank correlation coefficient also demonstrated that CSF cell counts (r=0.193, p=0.036), CSF microprotein content (r=0.379, p<0.001), serum aspartate aminotransferase (AST; r=0.521, p<0.001), serum lactate dehydrogenase (LDH; r=0.514, p<0.001) and activated partial thromboplastin time (APTT; r=0.326, p<0.001) correlated positively with the MRI groups, while platelet count (PLT; r=-0.633, p<0.001) and plasma fibrinogen (FIB; r=-0.258, p=0.005) correlated negatively.

CONCLUSION

Classification of brain MRI findings of HLH-CNS correlates well with the results of several key biochemical tests. Brain MRI is a promising method to elucidate illness severity and clinical outcomes.

[A case of difficult extubation after tracheotomy in a child with severe scald of oropharynx]

In November 4, 2016, a 1 year and 3 months old male patient with face and neck scald complicated with severe scald of oropharynx was admitted to Guangzhou Red Cross Hospital 1 hour after injury. The child developed upper respiratory tract obstruction 2 hours after injury, therefore tracheotomy and intubation were performed immediately to establish an artificial airway, and symptomatic treatments such as anti-infection, fluid replacement, and dressing change were conducted. On the 10th day after injury, the child had difficult breathing during the test tube blocking before extubation, and it was difficult to extubate. Symptomatic treatments such as ventilator assisted ventilation and strengthened anti-infection were continued. On the 17th day after injury, extubation plan was adjusted. Thirty minutes before extubation, phenobarbital was injected intramuscularly for sedation, and atropine was used to reduce airway secretions, after which extubation was successful. After 21 days of treatment, the child was cured and discharged. In the treatment of this case, high attention was paid to the important influence of children's mental factors among causes of difficult extubation, which provided a reference for clinical treatment of extubation in children with tracheal tube after tracheotomy.

[Effects of porcine acellular cartilaginous matrix on the proliferation and differentiation of human adipose-derived stromal cells]

OBJECTIVE

This study aimed to evaluate the effects of porcine acellular cartilaginous matrix (pACM) on the proliferation and differentiation of human adipose-derived stromal cells (hADSCs).

METHODS

pACM was prepared from porcine articular cartilage through decellularization treatment. hADSCs were isolated from human adipose tissues and cultured with different pACM concentrations. No pACM was used as the control group. The effect of pACM on hADSCs proliferation was detected by CCK-8 method. Moreover, the effect of pACM on hADSCs chondrogenic differentiation was analyzed through fluorescence quantitative polymerase chain reaction and Western blot.

RESULTS

hADSCs proliferation rate in 0.5, 1.0, and 2.0 mg·mL⁻¹ pACM groups was not significantly different from that in the control group, whereas that in 4.0 and 8.0 mg·mL⁻¹ pACM group was lower than that in the control group (P<0.05). The expression levels of pACM chondrogenic genes, including SOX-9, collagen type Ⅱ alpha 1 chain (COL2A1), and aggrecan (ACAN) and cell adhesion-related gene LAMININ in 0.5, 1.0, and 2.0 mg·mL⁻¹ pACM group were higher than those of the control group (P<0.05), but that of a stemness-related gene Notch-1 was lower than that of the control group (P<0.05). No statistical difference was found in the expression of a lipogenesis-related gene peroxisome proliferator-activated receptor-γ (PPAr-γ) (P>0.05). The expression levels of chondrogenic proteins (SOX-9, COL2A1, and ACAN) were higher than those of the control group (P<0.05).

CONCLUSIONS

Appropriate pACM con-centrations do not affect hADSCs proliferation but can induce hADSCs chondrogenic differentiation.

[Clinical characteristics, treatment and prognosis of myelin oligodendrocyte glycoprotein antibody-associated optic neuritis in children]

Objective: To investigate the clinical characteristics, treatment and prognosis of myelin oligodendrocyte glycoprotein antibody-associated optic neuritis (MOG-ON) in pediatric patients. Methods: Clinical data, laboratory examination, the initial best corrected visual acuity (BCVA), fundus, neuroelectrophysiological results, MRI imaging, treatment and prognosis of children diagnosed with MOG-ON from 2016 to 2019 were retrospectively analyzed. Results: A total of 29 eyes from 16 children were involved, with a male/female ratio of 1∶1, onset age of (7.0±2.9) years. Seven of 16 patients had prodromal infection, with a unilateral/bilateral ratio of 3∶13, and 2 cases had recurrent optic neuritis. Before treatment, BCVA of 19 eyes (65.5%) was ≤0.1, among them, 4 had no sense of light, 5 had light sense, 5 with sense of hands in front of eyes, and 5 with sense of fingers in front of eyes. There were 10 eyes (34.5%) with BCVA of 0.1-0.5. After treatment, there were 4 eyes (13.8%), 5 eyes (17.2%) and 20 eyes (69.0%) in groups with BCVA of 0.1-0.5, 0.5-1.0, and>1.0, respectively. Twelve of 16 patients had optic papillitis in fundus examination during acute phase. The latency was prolonged and the amplitude was decreased in P100 wave of all the children. Thirteen out of 16 children showed swelling and thickening of optic nerve in MRI T2WI. MRI images exhibited intracranial demyelinating lesions in 12 of 16 children and long segment spinal cord lesions in 3 of 16 children. Thirteen of 16 patients showed effective results after intravenous methylprednisolone (IVMP) and intravenous immunoglobulin (IVIG) treatment. There was no relapse after administration of mycophenolate mofetil in 2 recurrent children. No progression after administration of rituximab was found in 1 child with corticosteroid insensitivity. The average follow-up time was (16±9) months and no recurrence occurred. Ten of 16 patients had full recovery, 4 had significant improvement, and 2 showed no significant improvement. Conclusions: There is no significant gender difference in the incidence of pediatric MOG-ON. Bilateral involvement and severe visual impairment are common in acute phase. Most patients have good response to IVMP combined with IVIG treatment and hence have a good prognosis. Only a few of them have neurological sequelae.

[Study on the effect of diallyl sulfide on peripheral nerve injury in n-hexane intoxicated rats]

Objective: To investigate the antagonistic effect of diallyl sulfide (DAS) against peripheral nerve injury induced by n-hexane in rats. Methods: A total of 68 adult male Wistar rats were selected, among which 50 were randomly selected and divided into blank control group, DAS control group (100 mg/kg·bw) , n-hexane model group, low-dose DAS intervention group (50 mg/kg·bw) , and high-dose DAS intervention group (100 mg/kg·bw) . A rat model of peripheral nerve injury was established by n-hexane exposure, and the rats were treated with DAS at different doses. The changes in pyrrole adducts and behavior were observed, a metabolic analysis was performed for serum pyrrole adducts, and the intervention effect was evaluated. The remaining 18 rats were randomly assigned to the n-hexane model group, the low-dose DAS intervention group, and the high-dose DAS intervention group, with 6 rats in each group, as satellite groups used for the toxicokinetic analysis of serum pyrrole adducts. Results: Compared with the blank control group, the n-hexane model group and low-and high-dose DAS intervention groups had a significant reduction in body weight since week 2 (P<0.01) . Compared with the n-hexane model group at the end of the experiment at week 7, the high-dose DAS intervention group had a significantly higher body weight (P<0.05) , while there was no significant difference in body weight between the n-hexane model group and the low-dose DAS intervention group (P>0.05) . The n-hexane model group developed gait abnormality at week 2 of poisoning, while the low-and high-dose DAS intervention groups developed gait abnormality at weeks 3 and 5 of poisoning, respectively. At the end of the experiment, the n-hexane model group and the low-and high-dose DAS intervention groups had a significantly higher gait score than the blank control group (P<0.01) . At the end of the experiment, the n-hexane model group and the low-dose DAS intervention group had significantly shorter latency in rotarod test than the blank control group (P<0.01) , while there was no significant difference in latency between the DAS control group and the high-dose DAS intervention group (P>0.05) . Compared with the n-hexane model group, the low-and high-dose DAS intervention groups had a significant increase in latency in rotarod test (P<0.01) . Compared with blank control group, the n-hexane model group and the low-dose DAS intervention group had a significant increase in mean nerve conduction velocity (P<0.01) , while there was no significant difference between the blank control group and the DAS control group or high-dose DAS intervention group (P>0.05) , and compared with the n-hexane model group, the low-and high-dose DAS intervention groups had a significant increase in nerve conduction velocity (P<0.01) . Compared with the blank control group at the end of the experiment at week 7, the n-hexane model group and the low-and high-dose DAS intervention groups had significant increases in the concentration of pyrrole adducts in serum, urine, and hair (P<0.01) , while there was no significant difference between the blank control group and the DAS control group (P>0.05) , and the high-dose DAS intervention group had a significantly lower concentration of pyrrole adducts in serum, urine, and hair than the low-dose DAS intervention group (P<0.05) . Serum pyrrole adducts reached the peak level at 9-12 hours and then started to decrease. Compared with the n-hexane model group, the high-and low-dose DAS intervention groups had a significantly shorter half-life period of serum pyrrole adducts (P<0.01) . Compared with the n-hexane model group, the high-and low-dose DAS intervention groups had a significant reduction in the area under the curve of serum pyrrole adducts (P<0.05) . Conclusion: DAS can antagonize peripheral nerve injury induced by n-hexane.

Quantitative Analysis of DCE-MRI and RESOLVE-DWI for Differentiating Nasopharyngeal Carcinoma from Nasopharyngeal Lymphoid Hyperplasia

To explore the ability of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) analysis and readout segmentation of long variable echo-trains diffusion weighted imaging (RESOLVE-DWI) to distinguish nasopharyngeal carcinoma (NPC) from nasopharyngeal lymphoid hyperplasia (NPLH). Twenty-five patients with NPC and 30 patients with NPLH were evaluated. Three quantitative DCE-MRI parameters (Ktrans, Kep and Ve) and the apparent diffusion coeffcient (ADC) of lesions were calculated. The two independent samples t test or Mann-Whitney U test was used to compare the parameters between NPC and NPLH group. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic ability for distinguishing NPC from NPLH. A P value less than 0.05 was considered statistically significant. The difference in Ktrans value between the NPC group and the NPLH group was statistically significant, and the value of the NPC group was larger than that of the NPLH group. There was no statistical difference in Kep and Ve between the two groups. The ADC value of NPC group was smaller than that of NPLH group, and the difference was statistically significant. ROC curve analysis showed that both Ktrans and ADC were effective in diagnosing NPC and the area under the curve (AUC) was 0.773 and 0.704, respectively. In addition, the combination of Ktrans and ADC demonstrated the obviously improved AUC of 0.884. DCE-MRI and RESOLVE-DWI are effective in differentiating NPC from NPLH, especially the combination of the two models.

[Clinical features and prognosis of pediatric myelin oligodendrocyte glycoprotein antibody associated acute disseminated encephalomyelitis]

Objective: To analyze the clinical features, outcome and prognosis of pediatric myelin oligodendrocyte glycoprotein (MOG) antibody associated acute disseminated encephalomyelitis (ADEM), and provide evidence for improving the diagnosis and treatment of this disease. Methods: This study involved 30 MOG antibody-associated ADEM patients in the Department of Neurology, Guangzhou Women and Children's Medical Center. Patients' clinical information were analyzed. Results: The mean onset age was (5.2±3.3) years old, the ration of male to female was 16∶14. Fifty percent of these patients had a history of precede infection or vaccination before onset. Encephalopathy and seizures were the most common clinical manifestations, followed by movement disorder. In addition, some patients had other positive autoantibodies. Brain Magnetic resonance imaging (MRI) showed extensive, asymmetrical, indefinite large patchy lesions in bilateral cortical and subcortical areas and the spinal cord was characterized by long segmental myelitis. In acute attack, the patients had a good response to corticosteroid combined immunoglobulin therapy. Most of these patients had a good prognosis and recurrence rate was about 20%. Conclusions: The onset age of MOG antibody-associated ADEM is around 5 years old. Encephalopathy and seizures were the most common clinical manifestations. Most patients have a good response to corticosteroid combined immunoglobulin therapy. Some patients may have a recurrent disease course.