Manganese superoxide dismutase catalyzes the dismutation of two molecules of superoxide radicals to one molecule of oxygen and one molecule of hydrogen peroxide. The oxidation of superoxide anion to oxygen by Mn³⁺SOD proceeds at a rate close to diffusion. The reduction of superoxide anion to hydrogen peroxide by Mn²⁺SOD can be progressed parallelly in either a fast or a slow cycle pathway. In the slow cycle pathway, Mn²⁺SOD forms a product inhibitory complex with superoxide anion, which is protonated and then slowly releases hydrogen peroxide out. In the fast cycle pathway, superoxide anion is directly converted into product hydrogen peroxide by Mn²⁺SOD, which facilitates the revival and turnover of the enzyme. We proposed for the first time that temperature is a key factor that regulates MnSOD into the slow- or fast-cycle catalytic pathway. Normally, the Mn²⁺ rest in the pent-coordinated state with four amino acid residues (His26, His74, His163 and Asp159) and one water (WAT1) in the active center of MnSOD. The sixth coordinate position on Mn (orange arrow) is open for water (WAT2, green) or O₂^• to coordinate. With the cold contraction in the active site as temperature decreases, WAT2 is closer to Mn, which may spatially interfere with the entrance of O₂^• into the inner sphere, and avoid O₂^•/Mn²⁺ coordination to reduce product inhibition. Low temperature compels the reaction into the faster outer sphere pathway, resulting in a higher gating ratio for the fast-cycle pathway. As the temperature increases in the physiological temperature range, the slow cycle becomes the mainstream of the whole catalytic reaction, so the increasing temperature in the physiological range inhibits the activity of the enzyme. The biphasic enzymatic kinetic properties of manganese superoxide dismutase can be rationalized by a temperature-dependent coordination model of the conserved active center of the enzyme. When the temperature decreases, a water molecule (or OH^-) is close to or even coordinates Mn, which can interfere with the formation of product inhibition. So, the enzymatic reaction occurs mainly in the fast cycle pathway at a lower temperature. Finally, we describe the several chemical modifications of the enzyme, indicating that manganese superoxide dismutase can be rapidly regulated in many patterns (allosteric regulation and chemical modification). These regulatory modulations can rapidly and directly change the activation of the enzyme, and then regulate the balance and fluxes of superoxide anion and hydrogen peroxide in cells. We try to provide a new theory to reveal the physiological role of manganese superoxide dismutase and reactive oxygen species.

Objective:To investigate the value of ultrasonic measurement of the ratio of optic nerve sheath diameter (ONSD) to eyeball transverse diameter(ETD) in the diagnosis and prognosis of intracranial hypertension in patients with craniocerebral trauma.Methods:A total of 120 patients with craniocerebral trauma treated in the Xingtai General Hospital of North China Medical and Health Group from December 2021 to January 2023 were perspectively selected, and they were divided into normal intracranial pressure group (73 cases) and intracranial hypertension group (47 cases) according to the results of intracranial pressure measurements, and the intracranial hypertension group was divided into good prognosis group (20 cases) and poor prognosis group (27 cases) according to the follow-up prognosis. The efficacy of ONSD, ETD and ONSD/ETD in intracranial hypertension diagnosis and prognosis assessment were analyzed by receiver operating characteristic (ROC) curve. Kaplan-Meier method was used to evaluate the 6-month risk of adverse prognosis of patients, and the comparison was made by Log-rank test.Results:The levels of intracranial pressure, ONSD, ONSD/ETD in the normal intracranial pressure group were lower than those in the intracranial hypertension group: (130.73 ± 23.63) mmH 2O (1 mmH 2O = 0.009 8 kPa) vs. (270.11 ± 35.78) mmH 2O, (5.47 ± 0.29) mm vs. (5.78 ± 0.44) mm, 0.246 ± 0.018 vs. 0.263 ± 0.018, there were statistical differences ( P<0.05). The scores of Glasgow Coma Scale (GCS), intracranial pressure, ONSD, ONSD/ETD in the good prognosis group were lower than those in the poor prognosis group: (5.50 ± 1.24) scores vs. (6.41 ± 1.34) scores, (256.15 ± 30.23) mmH 2O vs. (280.44 ± 36.56) mmH 2O, (5.62 ± 0.40) mm vs. (5.90 ± 0.44) mm, 0.254 ± 0.014 vs. 0.270 ± 0.017, there were statistical differences ( P<0.05). ROC curve analysis results showed that the area under the curve (AUC) of ONSD and ONSD/ETD for diagnosing intracranial hypertension in patients with craniocerebral trauma were 0.718 and 0.765, respectively, and the critical values were 5.87 mm and 0.263, respectively. The AUC of ONSD and ONSD/ETD predicting prognosis of intracranial hypertension patients was 0.677 and 0.763, respectively, and the critical values were 5.90 mm and 0.267, respectively. Grouped by the threshold of ONSD/ETD for the prognosis of intracranial hypertension (0.267), the incidence of adverse prognosis in ONSD/ETD > 0.267 group was higher than that in the ONSD/ETD≤0.267 group, there was statistical difference ( P<0.05). Conclusions:ONSD/ETD can be used as an index for diagnosis and prognosis of intracranial hypertension.

On August 18,2023,the U.S.Food and Drug Administration(FDA)officially approved Regeneron's Pozelimab-bbfg(Veopoz?)for the treatment of complement factor H-related protein 5 deficiency type protein-losing enteropathy(CHAPLE)disease in children aged 1 and above,as well as adult patients.CHAPLE disease is a rare condition.Pazelimab monoclonal antibody is a recombinant monoclonal antibody(immunoglobulin G4 isotype).This antibody works by binding to the terminal complement protein C5,thereby preventing the cleavage of C5 into C5a(an anaphylatoxin)and C5b,and inhibit the activation of the terminal complement pathway.This article provides an overview of Pozelimab-bbfg,including its pharmacological research,pharmacokinetics,clinical studies,safety profile,and more,to introduce the current state of research and the achievements made with this drug.

Progressive ossifying fibrous dysplasia(FOP)is a rare,hereditary,and progressive connective tissue disease characterized by heterotopic ossification(HO)formation in muscles,joints,tendons,and ligaments,leading to major joint stiffness,limited movement,deformity,and severe disability in patients.In August 2023,Palovarotene was approved by the US Food and Drug Administration(FDA)to reduce the formation of HO in adults and children aged 8 years and above for females and 10 years and above for males with FOP.It is currently the only approved curable drug worldwide.Palovarotene is a selective retinoic acid receptor γ(RAR-γ)agonist that reduces the formation of HO by inhibiting bone morphogenetic protein and SMAD 1/5/8 signaling.The pharmacological study,pharmacokinetics,clinical research,and safety are reviewed to comprehensively introduce Palovarotene.

68Ga-DOTATOC injection is a radiopharmaceutical agent for positron emission tomography localization of somatostatin receptor positive neuroendocrine tumors(NETs)in adult and pediatric patients.68 Ga-DOTATOC binds to cells that express somatostatin receptors(SSTRs),including malignant neuroendocrine cells that overexpress SSTR2 receptor.Gallium-68 is a radionuclide used in positron emission tomography for tumor diagnosis.This paper introduces its the mechanism of action,pharmacokinetics,usage and dosage,clinical evaluation,safety and use in specific populations.

Pafolacianine is a fluorescent agent that specifically targets folate receptors,employed in the treatment of adult ovarian cancer patients to support the detection of malignant growths during surgical interventions.Pafolacianine binds to cancer cells expressing folate receptors,accumulating within folate-receptor-positive tumor tissue through receptor-mediated endocytosis.It can be excited by near-infrared fluorescence imaging,facilitating the surgical removal of tumors during procedures.This article gives an introduction to the mechanism of action,pharmacokinetics,clinical studies,and safety aspects of Pafolacianine.

Gadopiclenol was used in adults and pediatric patients 2 years of age and older during magnetic resonance imaging(MRI)to detect and view lesions of the central nervous system(brain,spine,and associated tissues)and body(head and neck,chest,abdomen,pelvis,and musculoskeletal system)with abnormal vascular properties.Gadopiclenol is a new type of macrocyclic gadolinium-based contrast agent(GBCA).In this article,the molecular structure,principle of action,pharmacodynamics,pharmacokinetics,clinical studies,safety and other aspects of Gadopiclenol were reviewed,in order to introduce the current research status and existing achievements of Gadopiclenol.

On September 3,2020,the U.S.Food and Drug Administration(FDA)granted formal approval to Copper Cu 64 dotatate(commercially known as Detectnet),for its pivotal role in diagnosing somatostatin receptor(SSTR)positive neuroendocrine tumors(NETs)in adult patients.This innovative diagnostic agent,Copper Cu 64 dotatate,is a sophisticated radionuclide that selectively targets somatostatin receptors,facilitating the emission of positron(β+)radionuclides in a quantity conducive for high-resolution positron emission tomography(PET)imaging.This review delves into the intricate mechanisms of action,the dynamic pharmacokinetics,comprehensive clinical studies,and the safety profile of Copper Cu 64 dotatate,highlighting its significance in the realm of medical diagnostics.

On May 27,2021,the U.S.Food and Drug Administration(FDA)officially approved Lantheus'PYLARIFY?(Piflufolastat F 18,18 F-labeled imaging agent),which can be used for positron emission computed tomography(PET)of prostate-specific membrane antigen(PSMA)-positive lesions in prostate cancer patients to accurately identify prostate cancer with suspected metastasis or recurrence.Piflufolastat F 18 is approved by FDA for two indications.The first is the initial staging for suspected metastatic lesions in men with newly diagnosed prostate cancer.The second is restaging,with the goal of identifying lesions in the setting of biochem ical recurrence.

This study was designed to investigate the effect of hypoxia on preeclampsia(PE)by modulating the Src/Siglec-6/SHP2 signaling pathway in the cytoplasm of trophoblast cells.Mouse model of PE was established in normal control and Siglec-6 knockdown mice by L-NAME administration,with aims of studying the changes in vascular diameter of spiral arteries in vivo and examining the expression levels of Siglec-6,p-Src,p-Shp2 and p-ERK1/2 proteins in mouse uterine vascular tissues.While,the effect of Src/Siglec-6/SHP2 on the invasive proliferation of trophoblast cells was explored by culturing human chorionic trophoblast cells HTR-8/SVneo with hypoxia in vitro.In vivo experimental assays showed that the diameter of spiral arteries was reduced in the Siglec-6 knockdown group of mice,and the expression levels of Siglec-6,p-Src,p-SHP2 and p-ERK1/2 proteins were significantly reduced.In vitro hypoxic HTR-8/SVneo cell model results revealed that Siglec-6 overexpression could promote trophoblast cell invasion and proliferation by regulating p-Src,p-SHP2,p-ERK1/2,MMP2,P53 and P21.While,suppression of Src and SHP2 eliminated Siglec-6 overexpression-mediated Siglec-6,p-Src,p-SHP2 and p-ERK1/2 expression,and inhibited the ability of Siglec-6 overexpression to mediate trophoblast invasion and proliferation.Taken together,Siglec-6 plays an important role in preeclampsia,and can alleviate preeclampsia by promoting trophoblast invasion and proliferation through the Src/SHP2 signalling pathway.