Prospective characterization of incident hepatic steatosis in pediatric and adolescent patients after total pancreatectomy with islet autotransplantation

BackgroundHepatic steatosis has been described as a common finding in adults following total pancreatectomy with islet autotransplantation (TPIAT) but it is unknown if this occurs in children and adolescents.ObjectivesTo define the frequency of post-TPIAT hepatic steatosis in a sample of children and adolescents and to identify clinical predictors of incident steatosis post-TPIAT.MethodsIn this prospective study, consecutive participants at least 1-month post-TPIAT underwent a liver MRI with proton density fat fraction (PDFF) and blood draw at our pediatric academic medical center between April 2021 and January 2022. Comparison clinical pre-TPIAT liver MRI or ultrasound and insulin use and graft function data were extracted from the medical record. T-tests were used for the comparison of means across continuous variables between participants with and without post-TPIAT steatosis.ResultsA total of 20 participants (mean: 13 ± 4 years; 12 female) were evaluated. Mean liver PDFF at research MRI was 7.4 ± 6.2% (range: 2–25%). Seven participants (35%) had categorical hepatic steatosis (PDFF>5%) post-TPIAT, five of whom had pre-TPIAT steatosis, reflecting a 13% (2/15; 95% CI: 2–40%) incidence of post-TPIAT steatosis. Participant characteristics were not significantly different between subgroups with and without post-TPIAT steatosis. Mean PDFF at research MRI was not different between graft function subgroups (7.5% optimal/good vs. 7.3% marginal/failure; p = .96).ConclusionOur study shows a moderate prevalence but low incidence of hepatic steatosis in a small sample of children and adolescents post-TPIAT. This study raises questions about a causal relationship between TPIAT and hepatic steatosis.     

Effect of a Device-Free Compressed Shell Fixation Method on Hepatic Respiratory Movement: Analysis for Respiratory Amplitude of the Liver and Internal Motions of a Fiducial Marker

Purpose

Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.

Iron Deficiency Anemia Associated With Acid-Modifying Medications: Two Cases and Literature Review

Iron deficiency anemia is often listed among potential adverse effects of gastric acid-suppressive medications, given that gastric acidity promotes intestinal absorption of nonheme iron. Additionally, the antacid calcium carbonate can inhibit iron absorption. However, there is little direct clinical evidence that proton-pump inhibitors, histamine-2 receptor antagonists, or calcium carbonate cause iron deficiency anemia. Most case reports have had substantial limitations (e.g., minimal follow-up and presence of other causes of iron deficiency), and retrospective cohort studies have lacked sufficient patient-specific detail to make strong causal inferences. We present 2 cases—both with detailed, prospective 10-year follow-up—in which combinations of proton-pump inhibitors, histamine-2 receptor antagonists and calcium carbonate were clearly associated with development of iron deficiency anemia. Overt iron-deficiency anemia is probably uncommon in patients who use acid-modifying medications and who have no other conditions that predispose to iron deficiency. Nevertheless, clinicians should be aware of this potential complication, given widespread use of these agents.     

Cathodes for fuel cells using proton-conducting Li2SO4–Al2O3 electrolyte

The performances of three widely different cathode materials (Pt, strontium-doped lanthanum manganite (LSM), and NiO) have been compared for use with proton conducting Li₂SO₄–Al₂O₃ composite electrolyte, using H₂S–air and H₂–air fuel cells operating at 600 °C. Surface analysis and electrochemical techniques were used to characterize fresh and used electrode materials. Pt or LSM cathodes each became covered with Li₂SO₄ and Al₂O₃ and, as a consequence, the fuel cells showed poor performance. In contrast, the NiO cathode catalyst did not become covered with Li₂SO₄ and good fuel cell performance was achieved. Exceptionally good current densities of over 100 mA/cm² and power densities of over 30 mW/cm² were obtained for H₂S–air fuel cells having Mo–Ni–S anode catalysts. Slight agglomeration of NiO particles during fuel cell operation had only a minor effect on performance.     

Mass-fractal-like microstructure and proton disorder in nanostructured pseudoboehmite: a neutron-scattering study

Boehmite (γ-AlOOH) is often the initial product in sol–gel syntheses of high surface-area alumina powders. Depending on the processing routes, the microstructure of an AlOOH powder can be tailored to exhibit nanometer particle size and complex interfacial OH sites. Neutron small-angle scattering (SANS) and spectroscopy were utilized to characterize the microstructure and hydrogen vibrations of a nanostructured pseudoboehmite and a highly crystallized boehmite powder. The SANS data reveal a mass-fractal-like microstructure in pseudoboehmite. The vibrational bands of hydrogen atoms in pseudoboehmite are broad, which is indicative of a high degree of proton delocalization and disordered OH sites.     

根除幽门螺杆菌疗效与细胞色素氧化酶P450 2C19基因多态性的关系

目的 比较雷贝拉唑与奥美拉唑三联疗法根除幽门螺杆菌（Hp）的疗效与细胞色素氧化酶P4502 C19（CYP 2C19）基因多态性的关系。方法 采用随机、对照研究方法，将169例因消化不良症状接受常规胃镜检查确诊为慢性胃炎且Hp阳性的连续患者分人两组：雷贝拉唑三联疗法组（RAC组85例）和奥美拉唑三联疗法组（OAC组84例）。Hp诊断依靠组织病理学检查并参考快速尿素酶试验、血清Hp抗体检测结果。RAC组、OAC组均给予三联治疗：RAC组：雷贝拉唑10mg，OAC组：奥美拉唑20mg，两组均联用羟氨苄青霉素1000mg和克拉霉素500mg，全部药物每日2次，疗程7d。采用聚合酶链式反应结合限制性内切酶技术（PCR-RFLP），进行CYP 2C19基因型分析，治疗结束后第28天用^14C尿素呼气实验检测Hp根除疗效。结果 160例完成治疗方案，RAC组及OAC组的Hp根除率按PP分析及ITT分析均无统计学差异（P〉0．05）。根据CYP 2C19基因型分析，160例中，弱代谢型（PM）、中间代谢型（IM）及强代谢型（EM）的Hp根除率分别为95．5%（21／22）、85．9％（73／85）和67．9％（36／53）。PM型及IM型的Hp根除率均显著高于EM型（P〈0．05），而PM型与IM型间差异无统计学意义（P〉0．05）。RAC组中，各基因型的Hp根除率差异无统计学意义（P〉0．05）。OAC组中。IM型与EM型间（P〈0．01）及EM型与PM型间（P〈0．05）差异均有统计学意义。结论 雷贝拉唑与奥美拉唑两种三联疗法均能有效根除Hp。总疗效差异无统计学意义。雷贝拉唑三联疗法疗效较稳定，个体间差异小。PM型及IM型的Hp根除率均较EM型为高。     

质子磁共振波谱对创伤后应激障碍患者海马神经元异常的诊断价值

目的 探讨质子磁共振波谱（1HMRS）在诊断创伤后应激障碍（post traumatic stress disorder，PTSD）患者海马神经元异常中的价值。方法 对19例PTSD患者及19例健康对照组行常规MRI和1HMRS检查。结果 PTSD患者MRI检查未出现信号的异常。19例患者两侧海马均显示NAA／Cr明显减低，与健康对照组相比，差异有统计学意义（P〈0．01）；而患者两侧海马的Cho／Cr与健康对照组相比，差异无统计学意义（P〉0．05）。结论 1HMRS揭示了PTSD时海马存在着神经元的丢失或功能紊乱，而这些改变是构成PTSD的神经生物学基础之一。     

In-situ measurements of gas permeability in fuel cell membranes using a cylindrical microelectrode

A new method to study permeation of gases in proton conducting membranes using a cylindrical microelectrode is presented. The focus of this work was to develop an in-situ method to study transport properties of hydrogen and oxygen close to real fuel cell operating conditions. The gas permeability is strongly affected by the change of water content in the membrane and it is therefore of advantage that, by using this method, measurements can be carried out over a wide range of relative humidities. The numerical method makes it possible to separate the diffusion coefficient and the concentration of dissolved gas in the membrane and also allows kinetic limitations to be taken into account. Chronoamperometric measurements on Nafion® 117 were successfully evaluated numerically. Experiments at temperatures of 25 and 60 °C with respect to oxygen permeation and at 60 °C for hydrogen permeation at relative humidities in the range 30–94% are presented. The reproducibility of data was excellent when measuring with different microelectrodes on the same membrane sample, but differed when measuring on different samples. In general, the permeability increases with increasing temperature and relative humidity.     

Efficacy in intra-oesophageal acid suppression may decrease after 2-year continuous treatment with proton pump inhibitors

BACKGROUND: Long-term intra-oesophageal acid suppression with proton pump inhibitors represents a management option for Barrett's oesophagus and severe reflux oesophagitis, but its stability over time has not been adequately assessed. AIM: Our aim was to evaluate prospectively the efficacy of proton pump inhibitors in suppressing intra-oesophageal acidity after 2-year continuous treatment. METHODS: Forty-five patients with Barrett's oesophagus or severe reflux oesophagitis on a proton pump inhibitor regimen (once or twice daily) that normalised the total percentage acid exposure time were re-evaluated by means of 24-h oesophageal pH-monitoring after 2-year of continuous unmodified treatment. RESULTS: A significant rise in the total percentage acid exposure time was observed at 2-year follow-up (P=0.029), owing to an increased value in 27 (60%) cases (9 on a twice daily regimen), higher than normal in 10 of them (22% of the whole group) (3 on a twice daily regimen). In 18 patients (40%) the total percentage acid exposure time was stable or decreased. Heartburn remained efficiently suppressed in all patients. CONCLUSIONS: The efficacy of proton pump inhibitors in suppressing intra-oesophageal acidity during continuous treatment may decrease over time, up to abnormal levels of oesophageal acid exposure in a minority of cases. This may occur without heartburn recurrence and with both once and twice daily regimens.