Physical Activity Levels and Factors Affecting Them in Hospitalized Children With Leukemia.

BACKGROUND: Physical activity promotes healthy physical and mental development in children with leukemia. However, the level of physical activity in hospitalized children with leukemia and the factors that influence it are unknown. OBJECTIVES: The aims of this study were to understand the physical activity level of hospitalized children with leukemia and to explore the factors influencing it to provide a reference for physical activity assessment and intervention in such children. METHODS: A total of 133 hospitalized children with leukemia completed a general information questionnaire, the Chinese University of Hong Kong Physical Activity Rating for Children and Youth, and the Children's Social Anxiety Scale. A cross-sectional study was used to explore the effects of different variables on the children's activity levels. RESULTS: Among the study participants, 44.4% had a low-intensity activity level, 35.3% had a moderate-intensity activity level, and 20.3% had a high-intensity activity level, with a total physical activity rating of 3 (1, 6). Chemotherapy phase (P = .007), screen time (P = .001), and social anxiety (P = .012) were identified as influential factors. CONCLUSIONS: Our results showed that children with hospitalized leukemia had lower-intensity physical activity levels, especially in the chemotherapy phase of induction remission. Furthermore, screen time and social anxiety had negative effects on the children's activity levels. IMPLICATIONS FOR PRACTICE: According to the physical activity level of the children and the influencing factors, healthcare professionals should gradually improve children's mobility and promote their physical and mental health development through guidance and encouragement, and the development of personalized activity intervention programs.

The impact of parental overprotection on the emotions and behaviors of pediatric hematologic cancer patients: a multicenter cross-sectional study.

Background: Parental overprotection may have an impact on children's emotional and behavioral problems (EBPs). As pediatric hematologic cancer patients have compromised immune systems, parents of such children often worry excessively, interfering with their daily lives. Therefore, avoiding overprotection is crucial for the overall physical and mental health of pediatric hematologic cancer patients. Aims: The aim of this study was to examine the current status of EBPs in pediatric hematologic cancer patients and analyze their associated risk factors. Design: This work was a multicenter cross-sectional observational and correlational study. We collected data anonymously through parental questionnaires from three pediatric hematologic oncology hospitals in China. The Strengths and Difficulties Questionnaire, the Parental Overprotection Measure (POM) scale, and a general information survey designed by the research team were employed to assess children's EBPs, the degree of parental overprotection, as well as basic demographic and disease-related information. Chi-square tests and generalized linear mixed-effects regression analysis were used to analyze the factors influencing EBPs among the pediatric hematologic cancer patients. Setting and participants: Using a convenience sampling method, a total of 202 participants' parents were selected. All participants were invited to complete the questionnaire through one-on-one guidance. Results: Emotional symptoms accounted for the highest proportion of abnormal EBPs in children (27.72%), followed by peer problems (26.24%), prosocial behavior (25.74%), behavioral problems (14.36%), and total difficulties (13.86%). A minority of children had abnormal hyperactivity scores (4.95%). The results of a generalized linear mixed regression analysis showed that age, duration of illness, and parental overprotection were significant factors influencing abnormal EBPs in children (p < 0.05). A POM score threshold of 37 exhibited good sensitivity (74%) and specificity (90%) in predicting abnormal EBPs in children. Conclusion: Pediatric hematologic cancer patients under excessive parental protection are more prone to experiencing EBPs. Healthcare professionals should guide parents to reduce this excessive protection, thus mitigating the occurrence of EBPs in children.

Channel Function of Polycystin-2 in the Endoplasmic Reticulum Protects against Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND: Mutations of PKD2, which encodes polycystin-2, cause autosomal dominant polycystic kidney disease (ADPKD). The prevailing view is that defects in polycystin-2-mediated calcium ion influx in the primary cilia play a central role in the pathogenesis of cyst growth. However, polycystin-2 is predominantly expressed in the endoplasmic reticulum (ER) and more permeable to potassium ions than to calcium ions. METHODS: The trimeric intracellular cation (TRIC) channel TRIC-B is an ER-resident potassium channel that mediates potassium-calcium counterion exchange for inositol trisphosphate-mediated calcium ion release. Using TRIC-B as a tool, we examined the function of ER-localized polycystin-2 and its role in ADPKD pathogenesis in cultured cells, zebrafish, and mouse models. RESULTS: Agonist-induced ER calcium ion release was defective in cells lacking polycystin-2 and reversed by exogenous expression of TRIC-B. Vice versa, exogenous polycystin-2 reversed an ER calcium-release defect in cells lacking TRIC-B. In a zebrafish model, expression of wild-type but not nonfunctional TRIC-B suppressed polycystin-2-deficient phenotypes. Similarly, these phenotypes were suppressed by targeting the ROMK potassium channel (normally expressed on the cell surface) to the ER. In cultured cells and polycystin-2-deficient zebrafish phenotypes, polycystin-2 remained capable of reversing the ER calcium release defect even when it was not present in the cilia. Transgenic expression of Tric-b ameliorated cystogenesis in the kidneys of conditional Pkd2-inactivated mice, whereas Tric-b deletion enhanced cystogenesis in Pkd2-heterozygous kidneys. CONCLUSIONS: Polycystin-2 in the ER appears to be critical for anticystogenesis and likely functions as a potassium ion channel to facilitate potassium-calcium counterion exchange for inositol trisphosphate-mediated calcium release. The results advance the understanding of ADPKD pathogenesis and provides proof of principle for pharmacotherapy by TRIC-B activators.

Factors of Parents-Reported Readiness for Hospital Discharge in Children with Acute Leukemia: A Cross-Sectional Study.

Aim: The aim of this study is to investigate the existing status and to explore the influencing factors of parents-reported readiness for hospital discharge in children with acute leukemia (AL) in China and to propose optimizing pathways and recommendations of discharge readiness for clinical reference. Methods: A cross-sectional survey was conducted for the 122 children with AL who were discharged from the Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University; their parents were investigated by using the modified Chinese version of Readiness for Hospital Discharge Scale (RHDS) and Quality of Discharge Teaching Scale (QDTS). Data were collected between September 2020 and May 2021.Univariate analysis and multivariate logistic regression analysis were performed to explore the influencing factors of readiness for hospital discharge. Results: The 122 children with AL included 52 females and 70 males with mean age 6.08 years. The total RHDS score was 7.7 ± 1.2, and 68.9% of the participants had high readiness for hospital discharge (RHDS score >7). The total QDTS score was 7.6 ± 2.0. Parent marital status (OR = 4.86, 95% CI: 1.31-18.05), education status (OR = 3.86, 95% CI: 1.18-12.55), family per capita monthly income (OR = 1.08, 95% CI: 1.01-2.99), and high QDTS (OR = 1.56, 95% CI: 1.11-2.68) were risk factors for high RHDS. Conclusions: Our data suggest parents of children with AL had high readiness for hospital discharge and had the ability to take care of their children after discharge. Parental marital status, education status, QDTS score, and family per capita monthly income were independently associated with high RHDS.

Draft genome sequence of Pseudomonas oleovorans strain MGY01 isolated from deep sea water.

Pseudomonas oleovorans MGY01 isolated from the deep-sea water of the South China Sea could effectively degrade malachite green. The draft genome of P. oleovorans MGY01 was sequenced and analyzed to gain insights into its efficient metabolic pathway for degrading malachite green. The data obtained revealed 109 Contigs (N50; 128,269 bp) with whole genome size of 5,201,892 bp. The draft genome sequence of strain MGY01 will be helpful in studying the genetic pathways involved in the degradation of malachite green.

Oxidant regulated inter-subunit disulfide bond formation between ASIC1a subunits.

The acid-sensing ion channel-1a (ASIC1a) is composed of 3 subunits and is activated by a decrease in extracellular pH. It plays an important role in diseases associated with a reduced pH and production of oxidants. Previous work showed that oxidants reduce ASIC1a currents. However, the effects on channel structure and composition are unknown. We found that ASIC1a formed inter-subunit disulfide bonds and the oxidant H(2)O(2) increased this link between subunits. Cys-495 in the ASIC1a C terminus was particularly important for inter-subunit disulfide bond formation, although other C-terminal cysteines contributed. Inter-subunit disulfide bonds also produced some ASIC1a complexes larger than trimers. Inter-subunit disulfide bond formation reduced the proportion of ASIC1a located on the cell surface and contributed to the H(2)O(2)-induced decrease in H(+)-gated current. These results indicate that channel function is controlled by disulfide bond formation between intracellular residues on distinct ASIC1a subunits. They also suggest a mechanism by which the redox state can dynamically regulate membrane protein activity by forming intracellular bridges.

Subunit-stoichiometric evidence for kir6.2 channel gating, ATP binding, and binding-gating coupling.

ATP-sensitive K(+) channels are gated by intracellular ATP, allowing them to couple intermediary metabolism to cellular excitability, whereas the gating mechanism remains unclear. To understand subunit stoichiometry for the ATP-dependent channel gating, we constructed tandem-multimeric Kir6.2 channels by selective disruption of the binding or gating mechanism in certain subunits. Stepwise disruptions of channel gating caused graded losses in ATP sensitivity and increases in basal P(open), with no effect on maximum ATP inhibition. Prevention of ATP binding lowered the ATP sensitivity and maximum inhibition without affecting basal P(open). The ATP-dependent gating required a minimum of two functional subunits. Two adjacent subunits are more favorable for ATP binding than two diagonal ones. Subunits showed negative cooperativity in ATP binding and positive cooperativity in channel gating. Joint disruptions of the binding and gating mechanisms in the same or alternate subunits of a concatemer revealed that both intra- and intersubunit couplings contributed to channel gating, although the binding-gating coupling preferred the intrasubunit to intersubunit configuration within the C terminus. No such preference was found between the C and N termini. These phenomena are well-described with the operational model used widely for ligand-receptor interactions.

Gating of the ATP-sensitive K+ channel by a pore-lining phenylalanine residue.

ATP-sensitive K(+) (K(ATP)) channels are gated by intracellular ATP, proton and phospholipids. The pore-forming Kir6.2 subunit has all essential machineries for channel gating by these ligands. It is known that channel gating involves the inner helix bundle of crossing in which a phenylalanine residue (Phe168) is found in the TM2 at the narrowest region of the ion-conduction pathway in the Kir6.2. Here we present evidence that Phe168-Kir6.2 functions as an ATP- and proton-activated gate via steric hindrance and hydrophobic interactions. Site-specific mutations of Phe168 to a small amino acid resulted in losses of the ATP- and proton-dependent gating, whereas the channel gating was well maintained after mutation to a bulky tryptophan, supporting the steric hindrance effect. The steric hindrance effect, though necessary, was insufficient for the gating, as mutating Phe168 to a bulky hydrophilic residue severely compromised the channel gating. Single-channel kinetics of the F168W mutant resembled the wild-type channel. Small residues increased P(open), and displayed long-lasting closures and long-lasting openings. Kinetic modeling showed that these resulted from stabilization of the channel to open and long-lived closed states, suggesting that a bulky and hydrophobic residue may lower the energy barrier for the switch between channel openings and closures. Thus, it is likely that the Phe168 acts as not only a steric hindrance gate but also potentially a facilitator of gating transitions in the Kir6.2 channel.

Kir6.2 channel gating by intracellular protons: subunit stoichiometry for ligand binding and channel gating.

The adenosine triphosphate-sensitive K(+) (K(ATP)) channels are gated by several metabolites, whereas the gating mechanism remains unclear. Kir6.2, a pore-forming subunit of the K(ATP) channels, has all machineries for ligand binding and channel gating. In Kir6.2, His175 is the protonation site and Thr71 and Cys166 are involved in channel gating. Here, we show how individual subunits act in proton binding and channel gating by selectively disrupting functional subunits using these residues. All homomeric dimers and tetramers showed pH sensitivity similar to the monomeric channels. Concatenated construction of wild type with disrupted subunits revealed that none of these residues had a dominant-negative effect on the proton-dependent channel gating. Subunit action in proton binding was almost identical to that for channel gating involving Cys166, suggesting a one-to-one coupling from the C terminus to the M2 helix. This was significantly different from the effect of T71Y heteromultimers, suggesting distinct contributions of M1 and M2 helices to channel gating. Subunits underwent concerted rather than independent action. Two wild-type subunits appeared to act as a functional dimer in both cis and trans configurations. The understanding of K(ATP) channel gating by intracellular pH has a profound impact on cellular responses to metabolic stress as a significant drop in intracellular pH is more frequently seen under a number of physiological and pathophysiological conditions than a sole decrease in intracellular ATP levels.

Critical protein domains and amino acid residues for gating the KIR6.2 channel by intracellular ATP.

K(ATP) channels couple intermediary metabolism to cellular excitability. Such a property relies on the inherent ATP-sensing mechanism known to be located in the Kir6 subunit. However, the molecular basis for the ATP sensitivity remains unclear. Here we showed evidence for protein domains and amino acid residues essential for the channel gating by intracellular ATP. Chimerical channels were constructed using protein domains of Kir6.2 and Kir1.1, expressed in HEK293 cells, and studied in inside-out patches. The N and C termini, although important, were inadequate for channel gating by intracellular ATP. Full ATP sensitivity also required M1 and M2 helices. Cytosolic portions of the M1 and M2 sequences were crucial, in which six amino acid residues were identified, i.e., Thr76, Met77, Ala161, Iso162, Leu164, and Cys166. Site-specific mutation of any of them reduced the ATP sensitivity. Construction of these residues together with the N/C termini produced ATP sensitivity identical to the wild-type channels. The requirement for specific membrane helices suggests that the Kir6.2 gating by ATP is not shared by even two closest relatives in the K(+) channel family, although the general gating mechanisms involving membrane helices appear to be conserved in all K(+) channels.

Hypercapnic acidosis activates KATP channels in vascular smooth muscles.

ATP-sensitive K+ channels (KATP) couple intermediary metabolism to cellular activity, and may play a role in the autoregulation of vascular tones. Such a regulation requires cellular mechanisms for sensing O2, CO2, and pH. Our recent studies have shown that the pancreatic KATP isoform (Kir6.2/SUR1) is regulated by CO2/pH. To identify the vascular KATP isoform(s) and elucidate its response to hypercapnic acidosis, we performed these studies on vascular smooth myocytes (VSMs). Whole-cell and single-channel currents were studied on VSMs acutely dissociated from mesenteric arteries and HEK293 cells expressing Kir6.1/SUR2B. Hypercapnic acidosis activated an inward rectifier current that was K+-selective and sensitive to levcromakalim and glibenclamide with unitary conductance of approximately 35pS. The maximal activation occurred at pH 6.5 to 6.8, and the current was inhibited at pH 6.2 to 5.9. The cloned Kir6.1/SUR2B channel responded to hypercapnia and intracellular acidification in an almost identical pattern to the VSM current. In situ hybridization histochemistry revealed expression of Kir6.1/SUR2B mRNAs in mesenteric arteries. Hypercapnia produced vasodilation of the isolated and perfused mesenteric arteries. Pharmacological interference of the KATP channels greatly eliminated the hypercapnic vasodilation. These results thus indicate that the Kir6.1/SUR2B channel is a critical player in the regulation of vascular tones during hypercapnic acidosis.