[Application of anti-programmed cell death protein 1 antibody in children with refractory or relapsed Hodgkin lymphoma].

Objective: To explore the efficacy of anti-programmed cell death protein 1 (PD-1) antibody for children with refractory or relapsed Hodgkin lymphoma. Methods: Clinical data including short-term efficacy, long-term efficacy and adverse reaction of Hodgkin lymphoma children treated with anti-PD-1 antibody in Beijing Children's Hospital, Capital Medical University from December 2017 to June 2021 were analyzed retrospectively. Efficacy was evaluated as complete remission (CR), partial remission (PR), stable disease (SD), progressed disease (PD) and no response. Results: A total of 6 cases were included, including 5 males and 1 female. The age at the start of anti-PD-1 antibody treatment was 11.6 (10.2, 13.3) years, including 3 cases of mixed cellularity type, 2 cases of nodular sclerosis type, and 1 case of nodular lymphocyte-predominant type. There were 4 cases of stage Ⅳ and 2 cases of stage Ⅲ. All cases were assigned to the high-risk group, and 5 cases had B symptoms, all cases were refractory or relapsed Hodgkin lymphoma before the start of anti-PD-1 antibody treatment. Early evaluation showed that within 12 weeks of the treatment, 3 cases achieved PR and 3 cases achieved SD, while late evaluation showed that after 16 weeks of the treatment, 5 cases achieved CR and 1 case achieved PR. None of the children progressed during treatment. The follow-up time was 27 (21,41) months. Among all cases, 5 cases had event-free survival and sustained remission, 1 case had fever about 4 weeks after the drug withdrawal, finally he was confirmed to be transformed to B cell lymphoma between diffuse B cells and classic Hodgkin lymphoma. All the patients were well tolerated with anti-PD-1 antibody therapy. No adverse reactions such as high fever, chills, rash, etc. were observed during infusion. None of the patients were delayed, dose reduction or withdrawal due to adverse reactions. Two cases had reactive skin vascular hyperplasia during the treatment, without pain or itching, and they recovered on their own after stopping anti-PD-1 antibody therapy without other special treatment. Conclusion: Anti-PD-1 monoclonal antibody for children with refractory or relapsed Hodgkin lymphoma have good efficacy and tolerable side effects.

[Evaluation of shoulder function after repairing head and neck defects with supraclavicular flap].

Objective: To evaluate the shoulder function in patients after repair of head and neck defects with supraclavicular flap. Methods: A retrospective analysis was performed on 56 patients (54 males, 2 females, aged 35-74 years old) who received the repair of head and neck defects with supraclavicular flaps at Department of Otorhinolaryngology Head and Neck Surgery of Beijing Tongren Hospital, Capital Medical University in January 2013-December 2020. The areas and types of flaps, disruption or infections of the incision at the donor sites and other postoperative complications were recorded. Quick disabilities of the arm, shoulder and hand (Quick-DASH) was used for evaluating the shoulder functions in 43 patients conforming to the standard for evaluation of the clinical functions of shoulders and upper limbs, to compare the postoperative upper limb functions between patients treated with clavicular flaps and patients with acromion flaps. Meanwhile, 30 patients who received bilateral neck lymph node dissection over the same period of time were selected for a comparative evaluation of the donor sides (observation group) and the opposite sides (control group). Data were processed with SPSS 22.0. Results: The areas of obtained supraclavicular flaps were (4-10) cm × (10-18) cm. Three patients (5%) showed the defect widths of 8-10 cm at the donor sites, which couldn't be sutured directly, received the repair of their shoulder defects with partial flaps. Defects in other patients were sutured directly. After surgery, 3 patients (5%) suffered from disruption of the acromion incision, which healed after 2 weeks of local dressing. The follow-up time was 6-43 (27±14) months. All patients expressed no dissatisfaction with the appearance. Among 43 patients, 28 (65%) were clavicular type and 15 (35%) were acromion type. The acromion type showed average motor ability and Quick-DASH scores higher than the clavicular type [(average motor ability: (14.4±4.7) vs. (11.8±3.1), t=2.105, P=0.048; Quick-DASH: (16.9±11.6) vs. (12.2±7.1), t=2.284, P=0.033]. Among 30 patients who received bilateral neck lymph node dissection over the same period of time, the observation group showed higher average motor ability, local symptoms and Quick-DASH scores than the control group [average motor ability: (13.4±5.8) vs. (9.8±4.2), t=3.024, P=0.004; average local symptoms: (4.1±1.0) vs. (3.4±1.0), t=2.537, P=0.014; Quick-DASH: (15.6±14.7) vs. (5.2±11.1), t=3.106, P=0.003]. Conclusion: Shoulder dysfunction exists after treatment with supraclavicular flap, which is related to the flap type.

Estimation of egg freshness using S-ovalbumin as an indicator.

The aim of this research was to study S-ovalbumin as a reference index for the freshness of commercial shell eggs in terms of equivalent egg age. The S-ovalbumin content, yolk index, albumen pH, and Haugh units were determined at the storage temperature of 25 and 37°C, respectively, using 85 fresh-laid eggs. A correlation analysis showed a high correlation coefficient of S-ovalbumin content to storage time as well as to the 3 frequently used freshness indices (Haugh unit, yolk index, and albumen pH). Furthermore, a prediction model of equivalent egg age at 25°C was established using S-ovalbumin content as an index on the basis of the correlation analysis. This study confirmed the possibility of using S-ovalbumin as a reference index to express commercial shell egg freshness as equivalent egg age.

Mechanism for the enhanced diffusion of charged oxygen ions in SiO2.

Based on real-space multigrid electronic structure calculations, we find that a double Si-O-Si bridge structure is the lowest energy configuration of interstitial oxygen ions (O(-) and O(2-)) in SiO2, where two additional Si-O bonds are formed with almost no interaction between the interstitial and host O atoms, while the peroxy linkage is the most stable structure for neutral interstitial O. We propose a diffusion mechanism of interstitial O ions generated from molecular O2 under UV radiation, and find extremely low energy barriers of 0.11--0.27 eV for migration in the form of the double-bridge structure, in good agreement with enhanced oxidation experiments.

Pattern of marine mass extinction near the Permian-Triassic boundary in South China.

The Meishan section across the Permian-Triassic boundary in South China is the most thoroughly investigated in the world. A statistical analysis of the occurrences of 162 genera and 333 species confirms a sudden extinction event at 251.4 million years ago, coincident with a dramatic depletion of delta13C(carbonate) and an increase in microspherules.

Tert-butylhydroperoxide bioactivation to methyl radical in rat liver mitochondria and submitochondrial particles.

Electron paramagnetic resonance spectroscopy (EPR) coupled to the spin trapping technique was used to detect carbon-centered radicals in rat liver mitochondria and submitochondrial particles exposed to t-butyl-hydroperoxide (TBH), using the spin trapping agent 3,5-dibromo-4-nitroso-benzenesulfonic acid (DBNBS). The signal recorded was unambiguously assigned to the methyl radical adduct. DBNBS was added to isolated rat liver mitochondria energized with succinate, and the methyl radical adduct was observed. The addition of NADH, NADPH, inhibitors of the respiratory chain, and of monoaminoxidase (MAO) inhibitors did not cause any relevant modification in the yield of radical adduct formation. Boiling and the addition of a non-ionic detergent inhibited the formation of the radical adduct, while experiments carried out under hypoxic conditions generated a significant increase in methyl radical formation. Further experiments were carried out on sub-mitochondrial particles (SMP) giving rise to, basically, the same results. From the above results, we are proposing that haem prosthetic groups are the likely source of TBH bioactivation in mitochondria.