[A 10-year retrospective analysis of spectrums and treatment options of orthostatic intolerance and sitting intolerance in children].

OBJECTIVE: To analyze the disease spectrums underlying orthostatic intolerance (OI) and sitting intolerance (SI) in Chinese children, and to understand the clinical empirical treatment options. METHODS: The medical records including history, physical examination, laboratory examination, and imagological examination of children were retrospectively studied in Peking University First Hospital from 2012 to 2021. All the children who met the diagnostic criteria of OI and SI were enrolled in the study. The disease spectrums underlying OI and SI and treatment options during the last 10 years were analyzed. RESULTS: A total of 2 110 cases of OI and SI patients were collected in the last 10 years, including 943 males (44.69%) and 1 167 females (55.31%) aged 4－18 years, with an average of (11.34±2.84) years. The overall case number was in an increasing trend over the year. In the OI spectrum, postural tachycardia syndrome (POTS) accounted for 826 cases (39.15%), followed by vasovagal syncope (VVS) (634 cases, 30.05%). The highest proportion of SI spectrum was sitting tachycardia (STS) (8 cases, 0.38%), followed by sitting hypertension (SHT) (2 cases, 0.09%). The most common comorbidity of OI and SI was POTS coexisting with STS (36 cases, 1.71%). The highest proportion of treatment options was autonomic nerve function exercise (757 cases, 35.88%), followed by oral rehydration salts (ORS) (687 cases, 32.56%), metoprolol (307 cases, 14.55%), midodrine (142 cases, 6.73%), ORS plus metoprolol (138 cases, 6.54%), and ORS plus midodrine (79 cases, 3.74%). The patients with POTS coexisting with VVS were more likely to receive pharmacological intervention than the patients with POTS and the patients with VVS (41.95% vs. 30.51% vs. 28.08%, χ2= 20.319, P < 0.01), but there was no significant difference in the proportion of treatment options between the patients with POTS and the patients with VVS. CONCLUSION: POTS and VVS in children are the main underlying diseases of OI, while SI is a new disease discovered recently. The number of children with OI and SI showed an increasing trend. The main treatment methods are autonomic nerve function exercise and ORS. Children with VVS coexisting with POTS were more likely to take pharmacological treatments than those with VVS or POTS only.

[Pulmonary arterial hypertension as leading manifestation of methylmalonic aciduria: clinical characteristics and gene testing in 15 cases].

OBJECTIVE: To deepen our understanding of Methylmalonic aciduria (MMA) associated pulmonary hypertension (PH) by analyzing the characteristics of clinical presentation, pulmonary high resolusion CT(HRCT), treatment response and gene mutation. METHODS: This study includes 15 cases of pediatric patients with MMA associated PH diagnosed and treated in Peking University First Hospital pediatric department between May 2012 and May 2016 with symptoms of PH as their leading presentation. Clinical symptoms and signs were recorded, Routine blood laboratory examinations was done including arterial blood gas analysis. Plasma total homocysteine (Hcy) and brain natriuretic peptide(BNP) level were measured. MMA gene mutation was analyzed. Chest HRCT was done in most of the patients. Standard treatment strategy to MMA and PH was given and follow up study was done, and the related literature was reviewed. Statistical analysis was done. The diagnosis of MMA was made by methylmalonic acid level >100 times the normal value in the urine. The diagnosis of PH was made by pulmonary arterial systolic pressure (PASP)>40 mmHg, which was estimated by the measurement of tricuspid regurgitation velocity through Doppler Echocardiography. RESULTS: (1) Patient characteristics: There were 10 male and 5 female patients diagnosed as MMA associated PH, aged 0.5 to 13.8 years, with an average of (5.0±4.3) years. The age of onset of PH was (3.7±3.5) years, with an early onset type MMA in 5 cases and late-onset type in 10 cases. (2) Clinical presentation: Among the 15 cases of MMA, the first symptoms were associated with PH in 10 cases, so PH and MMA were diagnosed at the same time, and PH was diagnosed 3 to 72 months post MMA presentation in the other 5 cases. The main presentations of PH were techypnea/dyspnea and cyanosis in 11 cases each, weakness and fatigue on exertion in 6 cases, and edema in 4 cases. PH WHO functional classification (WHO FC) was Class II in 4 , Class III in 5 and Class VI in 6 cases, with an average of Class 3.1±0.8. Multi-system involvements were common with the highest frequency in the kidney (14 cases). Macrocytic anemia was present in 8 cases and sub-clinical hypothyroidism in 5 cases, and mild to moderate mental retardation in 4 cases. (3) Laboratory examination: PASP of the 15 patients was from 49 to 135 mmHg, with an average of (90.3±23.9) mmHg. Total blood Hcy level was severely elevated to (121.2±48.2) µmol/L (range: 35.0-221.0 µmol/L), and Hcy >100 µmol/L within 11 cases. Plasma BNP level was also elevated, median 794 ng/L (range: 21.0-4 995.0 ng/L) with 12 cases >300 ng/L. Blood gas analysis showed low arterial blood oxygen saturation between 70% and 94%, with an average of 81.4%±8.4%. (4) Chest HRCT: chest HRCT showed a diffuse ground-glass centrilobular nodular opacities with septal line thickening in the lungs in 9 cases, and with associated mediastinal lymph node enlargement in 1 case, which indicated pulmonary veno-occlusive disease (PVOD), a rare type of pulmonary arterial hypertension (PAH). There was lung infection or edema in 3 cases, and interstitial infiltration and mesh-like feature in other 3 cases, which was inferred to interstitial lung disease. (5) Gene mutation: Genetic testing was done in 10 cases, totally 5 reported disease-causing mutations were found. There were 100% presence of MMACHC c.80A>G mutation in all the 10 patients tested, with the allelic genes of c.609G>A mutation in 6 patients, including a sister and a brother from the same parents. (6) Treatment and follow up: Intramuscular hydroxocobalamin or vitamin B12 was given to all of the patients, together with betaine, levocarnidtine, folinic acid and vitamin B6. According to the severity of PH, single or combined PAH targeted drugs was given to 11 cases. By an average of (20.0±13.5) days of in-hospital treatment in 13 patients (excepting 1 case treated as outpatient), symptoms remarkably resolved, WHO FC reduced to an average of Class 2.4±0.9, PASP dropped to (69.4±21.3) mmHg, and plasma Hcy and BNP level were decreased to (74.9±25.9) µmol/L and (341.6±180.2) ng/L, respectively. The above values all reached statistical significance (P<0.05) compared with each related value before treatment. There were 2 patients who expired during hospitalization despite of treatment. At the end of 3 months' follow up, all of the 13 patients disposed oxygen, and PASP significantly dropped to 38.7±7.9 mmHg, and plasma BNP returned to normal, but plasma Hcy level showed no further decline. At the last follow up of 27.5±19.0 (range: 11-64) months, all the patients' PASP remained normal except for the 13.8-year-old boy with 6 years-long history of MMA and almost 3.6 years' history of PH still having PASP 58 mmHg. CONCLUSION: PH is a severe complication of MMA combined type, especially cblC type, it is more often happens in late-onset type of male patients and can be the first and leading manifestations of MMA. Its clinical symptoms are urgent and severe, characterized by tachypnea/dyspnea and cyanosis, and sometimes right heart failure, hypoxemia is usually present, chest HRCT is often indicative of PVOD, lung edema and interstitial lung disease may occur. Rapid diagnosis and targeted treatment of MMA with appropriate anti-PAH medication can reverse PH and save life. MMACHC gene c.80A>G mutation may be the hot point of MMA cblC type associated PH.

Real-space observation of strong metal-support interaction: state-of-the-art and what's the next.

The real-space resolving of the encapsulated overlayer in the well-known model and industry catalysts, ascribed to the advent of dedicated transmission electron microscopy, enables us to probe novel nano/micro architecture chemistry for better application, revisiting our understanding of this key issue in heterogeneous catalysis. In this review, we summarize the latest progress of real-space observation of SMSI in several well-known systems mainly covered from the metal catalysts (mostly Pt) supported by the TiO2 , CeO2 and Fe3 O4 . As a comparison with the model catalyst Pt/Fe3 O4 , the industrial catalyst Cu/ZnO is also listed, followed with the suggested ongoing directions in the field.

Association between MYC rs9642880[T] allele and bladder cancer risk: a meta-analysis.

A single nucleotide polymorphism of MYC rs9642880 (G>T) at the 8q24.1 locus is thought to be associated with bladder cancer risk based on the results of genome-wide association studies, but the results remain inconclusive. To assess the association between rs9642880[T] allele and bladder cancer risk, we performed this meta-analysis including 18 case-control studies and involving 23,084 cases and 97,164 controls. Electronic searches for publications were conducted to determine the association between this variant and prostate cancer in several databases. The last search update was August 4, 2014. We used odds ratios and 95%CIs to evaluate the strength of the associations. The overall results suggested that the rs9642880[T] allele was associated with bladder cancer susceptibility (T vs G, odds ratio = 1.18, 95%CI = 1.14-1.22). In subgroup analysis by ethnicity and source of controls, the risk remained significant. The present meta-analysis suggests that the MYC rs9642880[T] allele is significantly associated with bladder cancer risk.

Meta-analysis of the association between the HNF1B rs4430796 (A>G) polymorphism and risk of prostate cancer based on case-control studies.

Genome-wide studies have reported an association between the HNF1B rs4430796 (A>G) polymorphism and prostate cancer risk, but results have been inconsistent and recent meta-analyses have been inadequate. This study aimed to integrate previous results and explore the validity of this association. Electronic searches for all relevant publications through May 18, 2014, were conducted across several databases. Additional studies were identified manually, and only the most recent or complete were used in this meta-analysis. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. Seven eligible case-control studies were identified, incorporating a total of 14,049 patients and 12,674 controls. Overall, we found that the rs4430796 (A>G) polymorphism had a decreased risk of prostate cancer (GG vs AA: OR = 0.661, 95%CI = 0.615-0.710, P = 0.304; AG vs AA: OR = 0.782, 95%CI = 0.739-0.828, P = 0.435; dominant model: OR = 0.743, 95%CI = 0.704-0.784, P = 0.912; recessive model: OR = 0.764, 95%CI = 0.718-0.813, P = 0.01). Furthermore, in the stratified analysis, there were significantly decreased risks among studies with population- and hospital-based controls. In the subgroup analysis by ethnicity, significantly decreased risks were also found among Caucasians, Americans, and Asians. Our results suggested that the HNF1B rs4430796 (A>G) polymorphism decreased the risk of prostate cancer. In the future, additional and larger studies on patients from across of the world might be required to validate our findings.

How important is the {103} plane of stable Ge2 Sb2 Te5 for phase-change memory?

Closely correlating with {200} plane of cubic phase, {103} plane of hexagonal phase of Ge(2)Sb(2)Te(5) plays a crucial role in achieving fast phase change process as well as formation of modulation structures, dislocations and twins in Ge(2)Sb(2)Te(5). The behaviors of {103} plane of hexagonal phase render the phase-change memory process as a nanoscale shape memory.

[The pressor response induced by electrical stimulation of hypothalamic paraventricular nucleus in the cat].

The experiments were performed on 24 adult cats anesthetized with chloralose and urethane, paralyzed and artificially ventilated. Electrical stimulation of the hypothalamic paraventricular nucleus (PA) with a 12s train of 0.1-0.5 mA and 0.2ms square wave pulses at a frequency of 80 Hz induced a marked increase in arterial blood pressure (n = 19). The 22 points stimulated with maximum responses were clustered in the posterior dorsomedial part of the PA, among them 11 points were associated with an increase in heart rate and 7 a decrease. The remaining 4 points were associated with no change of heart rate, and situated in the anterior part of the PA. Electrolytic lesion of bilateral caudal half of the nucleus of solitary tract (NTS) had no significant effect on cardiovascular responses elicited from electric stimulation of the PA (n = 5). The results suggest that the PA is one of the important centers regulating cardiovascular activity; the NTS may not be involved in the PA pressor response.