[Recurrence factors for myelin oligodendrocyte glycoprotein antibody disease in children and the effect of recurrence prevention regimens].

OBJECTIVE: To study the clinical features and recurrence factors of myelin oligodendrocyte glycoprotein (MOG) antibody disease in children and the effect of recurrence prevention regimens. METHODS: A retrospective analysis was performed on the medical data of 41 children with MOG antibody disease who were hospitalized in the Department of Pediatric Neurology, Xiangya Hospital of Central South University, from December 2014 to September 2020. According to the presence or absence of recurrence, they were divided into a monophasic course group (n=19) and a recurrence group (n=22). According to whether preventive treatment for recurrence was given, the children with recurrence were further divided into a preventive treatment group and a non-preventive treatment group. The clinical features were analyzed for all groups, and the annualized relapse rate (ARR) was compared before and after treatment with prevention regimens. RESULTS: For these 41 children, acute disseminated encephalomyelitis was the most common initial manifestation and was observed in 23 children (56%). Of the 41 children, 22 (54%) experienced recurrence, with 57 recurrence events in total, among which optic neuritis was the most common event (17/57, 30%). The proportion of children in the recurrence group who were treated with corticosteroids for less than 3 months in the acute phase was higher than that in the monophasic course group (64% vs 32%; P < 0.05). There was no significant difference in the ARR between the preventive treatment and non-preventive treatment groups (P > 0.05). The assessment of preventive treatment regimens for 32 cases showed that the children treated with rituximab or azathioprine had a significant reduction in the ARR during treatment (P < 0.05). CONCLUSIONS: More than half of the children with MOG antibody disease may experience recurrence. Most children with recurrence are treated with corticosteroids for less than 3 months in the acute phase. Rituximab and azathioprine may reduce the risk of recurrence.

[A school-aged boy with nephrotic syndrome with cough for one month and shortness of breath for half a month].

A boy, aged 6 years and 11 months, was admitted due to nephrotic syndrome for 2 years, cough for 1 month, and shortness of breath for 15 days. The boy had a history of treatment with hormone and immunosuppressant. Chest CT after the onset of cough and shortness of breath showed diffuse ground-glass opacities in both lungs. Serum (1, 3)-beta-D glucan was tested positive, and the nucleic acid of cytomegalovirus was detected in respiratory secretions. After the anti-fungal and anti-viral treatment, the child improved temporarily but worsened again within a short period of time. Pneumocystis jirovecii was identified by Gomori's methenamine silver staining in bronchoalveolar lavage fluid. The child was diagnosed with severe pneumonia (Pneumocystis jirovecii and cytomegalovirus infection), acute respiratory distress syndrome, and nephrotic syndrome. After anti-infective therapy with sulfamethoxazole/trimethoprim and ganciclovir and respiratory support, the child still experienced progressive aggravation of dyspnea and tension pneumothorax, and extracorporeal membrane oxygenation (ECMO) was given on day 13 of invasive ventilation. Anti-infective therapy with sulfamethoxazole/trimethoprim, ganciclovir, and linezolid, anticoagulation therapy, sedation therapy, nutrition, and comprehensive management of the respiratory tract were given during ECMO. The child was successfully weaned from ECMO after 72 days, resulting in a length of hospital stay of 134 days. The child was followed up for 6 months after discharge, and there was a significant improvement on lung CT, without organ dysfunction. It is concluded that Pneumocystis jirovecii pneumonia is a potential lifethreatening infection for children with low immunity, and that ECMO can effectively improve the prognosis of children with severe respiratory distress syndrome.

[Diagnosis and treatment of 3-hydroxyisobutyryl-CoA hydrolase deficiency: a case report and literature review].

A case of 3-hydroxyisobutyryl-CoA hydrolase deficiency was reported, and its clinical features, gene mutation characteristics, and diagnosis and treatment were analyzed with reference to related literature. The patient aged 1 year and 6 months had developmental regression and paroxysmal dystonia after pyrexia and diarrhea, and head MRI showed symmetrical lesions in the bilateral basal ganglia. No pathogenic mutation was found in the full-length detection of mitochondrial genome. Nuclear gene detection of mitochondrial-related diseases found new compound heterozygous mutations in the HIBCH gene, i.e., c.439-2A>G and c.958A>G (p.K320E), which were inherited from his father and mother, respectively. The boy was given cocktail therapy, dietary valine restriction, and symptomatic treatment. After 2 weeks of treatment, there were improvements in dystonia and motor and intellectual development.

[Fever, generalized pain, and multiple pulmonary nodules in a school-aged boy].

A 9-year-old boy was admitted to Xiangya Hospital due to pain after trauma in the left lower limb for 5 days and fever with generalized pain for 2 days. The results of X-ray of the left lower limb were normal. Pulmonary computed tomography (CT) showed multiple pulmonary nodules in both lungs. Adrenal CT showed marked enlargement of the left adrenal gland. The patient also experienced generalized herpes and intermittent delirium and had a blood pressure up to 155/93 mm Hg. He was transferred to our hospital with a suspected diagnosis of pheochromocytoma. On admission, the patient had a blood pressure of 86/44 mm Hg, sporadic maculopapule and herpes, touch-evoked pain, exposure of superficial veins, white pus coating on the right side of the tongue, and tension in the abdominal muscle. No skin damage was observed in the left lower limb, and the patient was forced to be in the extending position and experienced significant swelling below the knees. Laboratory examination showed a reduction in platelet count, hypoproteinemia, a significant increase in creatase, a C-reactive protein level of 348 mg/L, and a procalcitonin level of >100 ng/mL. Thoracoabdominal and pelvic CT showed multiple patchy and nodular lesions in both lungs, which had an undetermined nature, as well as an enlarged spleen. The tests of puncture fluid from the left knee joint and the periosteum of the left tibia, blood culture, and bone marrow culture all showed methicillin-resistant Staphylococcus aureus. The patient was given anti-shock treatment, anti-infective therapy with vancomycin, debridement and continuous irrigation/drainage of osteomyelitis lesions in the left tibia, but the patient still experienced recurrent shivering and severe fever and increased subcutaneous and pulmonary nodules. Linezolid was added on day 8 after admission, and the patient's body temperature returned to normal on day 24 after admission. Subcutaneous and pulmonary nodules were gradually reduced and disappeared. The patient was treated for 2 months and then evaluated as cured.

[A complicated case study: Hennekam syndrome].

Hennekam syndrome (HS) is a rare autosomal recessive syndrome characterized by defective lymphatic development. A 34-month-old boy with HS and who had unexplained developmental retardation and hypoalbuminemia as main clinical manifestations is reported here. He had a history of generalized edema and poor feeding. He was not thriving well. He manifested as facial anomalies (hypertelorism, flat nasal bridge and flat face), fracture of teeth, and superficial lymph nodes enlargement. He had low serum total protein, low serum albumin, and low serum immunoglobulin levels. Duodenal bulb biopsy revealed lymphangiectasia. Color Doppler ultrasound, magnetic resonance imaging and CT scan showed multi-site lymphangioma, and HS was thus confirmed. Mutations in CCBE1 and FAT4 have been found responsible for the syndrome in a part of patients. Diagnosis of the disease depends on the familial history, clinical signs, pathological findings and genetic tests.

Mechanisms of tumor necrosis factor-alpha-induced leaks in intestine epithelial barrier.

PURPOSE: The aim of this study was to investigate the signaling mechanisms surrounding changes in tight junction (TJ) and the permeability of human intestinal epithelial cell induced by tumor necrosis factor-alpha (TNF-α). METHODS: To confirm that TNF-α induces epithelial barrier hyperpermeability by disrupting tight junction, Caco-2 cells were exposed to TNF-α, and changes in epithelial permeability (via TER assay), F-actin dynamics (via Rhodamine-phalloidin staining) and tight junction protein expression (via western blot) were monitored. Moreover, to ensure that NF-κB participated in the regulatory mechanisms, Caco-2 cells were transfected with DNMu-IκBα or control plasmids, the above experiments were repeated and the activation effect of TNF-α on NF-κB was detected by luciferase reporter assays. Lastly, we took dominant negative plasmid and knockdown approaches to investigate the potential importance of the NF-κB/myosin light chain kinase (MLCK)/myosin light chain phosphorylation (pMLC) pathways in TNF-a-mediated damage. RESULT: TNF-α could cause NF-κB activation, F-actin rearrangement, tight junction disruption and barrier dysfunction. These effects were alleviated by inhibiting NF-κB. TNF-α induced increase of MLCK transcription and MLC phosphorylation act later than NF-κB activation, which could be suppressed both by inactivating and deleting NF-κB. CONCLUSIONS: TNF-α induces intestinal epithelial cell hyperpermeability by disrupting TJs, in part through MLCK upregulation, in which NF-κB is the positive upstream regulator for MLCK.

[Succinic semialdehyde dehydrogenase deficiency].

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal recessive disorder. This paper reports three cases of SSADH deficiency in infants. The infants developed the symptoms including developmental delay, intellectual disability, hypotonia, hyporeflexia and seizures. The electroencephalogram (EEG) showed background slowing and focal spike discharges in all of 3 patients. Head magnetic resonance imaging (MRI) demonstrated abnormalities in 2 patients, including basal ganglia damage and increased T2-weighted signal in bilateral cerebral peduncles. Urinary organic acid analysis with gas chromatography-mass spectrometry (GC-MS) revealed increased levels of 4-hydroxybutyrate (GHB) in 3 patients. SSADH deficiency was definitely diagnosed based on the clinical manifestations and the results of urinary organic acid analysis in the 3 children. It was concluded that early urine organic acid analysis is essential for children presenting with mental retardation, neuropsychiatric disturbance or epilepsy of unknown etiology.

[Influence of lipopolysaccharide on the permeability of rat brain microvascular endothelial cells and the molecular mechanism].

OBJECTIVE: To study the influence of lipopolysaccharide (LPS) on the permeability of rat brain microvascular endothelial cells (BMECs) and possible molecular mechanism. METHODS: Monolayers of primary rat BMECs were separated and cultured, and then treated with (LPS group) or without LPS (control group). The barrier integrity was measured by transendothelial electrical resistance (TEER) assay. The degrees of RhoA activation were determined by Pull-down assay. The expression levels of p115RhoGEF, zonula occludens-1 (ZO-1), occludin and claudin-5 proteins were detected by Western blot analysis. RESULTS: The average TEER values of rat BMECs in the LPS group were 108.3±4.2 Ω•cm2 and 85.4±2.5 Ω•cm2 respectively 3 and 12 hrs after LPS treatment, which were significantly lower than that in the control group (159.0±8.6 Ω•cm2). Compared with the control group, the activity of RhoA started to increase 5 minutes after LPS treatment, and the expression of p115RhoGEF protein started to increase 1 hr after LPS treatment and the cellular protein levels of ZO-1, occludin and claudin-5 decreased significantly 3 hrs after LPS treatment in the LPS group (P<0.05). CONCLUSIONS: LPS may activate the p115RhoGEF/RhoA pathway and decrease protein expression of ZO-1, occludin and claudin-5, resulting in an increased permeability of rat BMECs.

[Immortalized mouse brain endothelial cell line Bend.3 displays the comparative barrier characteristics as the primary brain microvascular endothelial cells].

OBJECTIVE: The purpose of this study was to assess weather the immortalized mouse brain endothelial cell line Bend.3 displays the comparative barrier characteristics as the primary brain microvascular endothelial cells (BEMC). METHODS: Immortalized mouse brain endothelial cell line, Bend.3 cells were cultured in transwell inserts and their restrictive characteristics were assessed by transendothelial electrical resistance (TEER) and horseradish peroxidase (HRP) permeability assays. Western blot and direct fluorescent staining methods were used to detect the tight junction protein expression and F-actin distribution. RESULTS: The TEER in Bend.3 cells increased with the prolonged culture time and increased to 82.3+/-6.0 Omega cm2 10 days after culture, which was significantly higher than that 3 days after culture (37.3+/-3.1 Omega cm2; P<0.05). There were significant differences in the permeability rates for HRP 3 and 10 days after culture (4.3+/-0.20)% vs (2.2+/-0.05)% (P<0.05). Western blot indicated high level expression of tight junction proteins occludin and ZO-1 in Bend.3 cells 10 days after culture. F-actin was visualized around the cell membrane and presented scrobiculate linear fluorescence 10 days after culture. CONCLUSIONS: Bend.3 cells have similar barrier characteristics to BEMC, and their barrier function may reach to the best effect 10 days after culture.

HGF protects cultured cortical neurons against hypoxia/reoxygenation induced cell injury via ERK1/2 and PI-3K/Akt pathways.

Hepatocyte growth factor (HGF) has been revealed to exert multipotent activities on a variety of cells. In this study, we investigated whether HGF had a direct neuroprotection on cultured cerebral cortical neurons subjected to hypoxia/reoxygenation (H/R) and explored the intracellular signalings mediated the effects. The decrease in cell viability and increase in number of apoptotic cells resulting from H/R were significantly prevented by HGF pre-treatment. HGF stimulated both ERK1/2 and Akt activities in cortical neurons. Inhibition of ERK activation completely abolished the protective effects of HGF, and inhibition of Akt activation reduced, but did not completely eliminate the HGF mediated neuroprotection. It is suggested that the neuroprotection of HGF depend on ERK1/2 pathway, and, to a lesser extent, PI-3K/Akt pathway. In addition, we found that pre-treatment with HGF remarkably attenuated the decrease in expression of Bcl-2 and Bcl-xL induced by H/R, but failed to affect the amount of Bax. It is likely that Bcl-2 and Bcl-xL contribute to the protective effects of HGF.

[Protection of hepatocyte growth factor on neurons subjected to oxygen-glucose deprivation/reperfusion].

The present study was conducted to investigate the effect of hepatocyte growth factor (HGF) on cortical neurons exposed to oxygen-glucose deprivation/reperfusion (OGD/R). Primary cultured cerebral cortical neurons were prepared from Sprague-Dawley rats. The cells were used for experiments after culture for 12 d in vitro. To initiate OGD/R, the culture medium was replaced by glucose-free medium, and cells were transferred to a humidified incubation chamber flushed by a gas mixture of 95% N(2) and 5% CO(2) at 37 °C for 2 h. Following this treatment, neurons were fed with glucose-supplemented (25 mmol/L) medium, and returned to the incubator under normoxic condition for 0-24 h. The cell viability was assessed by MTT assay, and cell injury was evaluated by lactate dehydrogenase (LDH) leakage rate. The percentage of apoptotic cells was analyzed by flow cytometry and Hoechst 33258 staining. The expressions of c-Met mRNA and protein were detected by RT-PCR and Western blot analysis, respectively. Oxygen-glucose deprivation for 2 h decreased the cell viability and increased LDH leakage rate in cultured cerebral cortical neurons. The cell viability declined and LDH leakage rate increased with the reperfusion time going on (0-24 h). To explore the influence of HGF on neurons under oxygen-glucose deprivation for 2 h/reperfusion for 24 h (OGD(2)/R(24)) condition, the cultures were pretreated with HGF at different concentrations (5-120 ng/mL) 2 h prior to OGD(2)/R(24). The results showed that OGD(2)/R(24) treatment significantly decreased the cell viability, increased LDH leakage rate and the percentage of apopototic cells. Pretreatment with HGF at 5 ng/mL and 10 ng/mL did not affect the decrease in cell viability resulting from OGD(2)/R(24). In the presence of 20 ng/mL HGF, the increase in cell viability in cortical neurons exposed to OGD(2)/R(24) began to appear, and 80 ng/mL of HGF exhibited the maximal effect. HGF at 5, 10 and 20 ng/mL did not affect the increase in LDH leakage rate in cortical neurons exposed to OGD(2)/R(24). In the presence of 40 ng/mL HGF, the decrease in LDH leakage rate in cortical neurons subjected to OGD(2)/R(24) began to appear, and 80 ng/mL of HGF displayed the maximal effect. In addition, HGF at 80 ng/mL significantly attenuated cell apoptosis resulting from OGD(2)/R(24). As detected by semi-quantitative RT-PCR and Western blot analysis, c-Met mRNA and protein were expressed in cerebral cortical neurons cultured for 12 d in vitro. c-Met mRNA and protein expressions in cortical neurons exposed to OGD(2)/R(24) were significantly upregulated and were not affected by pretreatment of HGF at 80 ng/mL. Treatment with c-Met inhibitor SU11274 (5 µmol/L) completely eliminated HGF-mediated protection of cortical neurons subjected to OGD(2)/R(24). The results suggest that HGF directly protects cortical neurons against OGD/R-induced cell injury in a dose-dependent manner, and HGF has a potent anti-apoptotic action on neurons exposed to OGD/R.