[A randomized controlled trial on the effect of early eschar dermabrasion combined with antimicrobial soft silicone foam dressing in the treatment of deep partial-thickness burn wounds in children].

Objective: To explore the effect of early eschar dermabrasion combined with antimicrobial soft silicone foam dressing (hereinafter referred to as foam dressing) in treating the deep partial-thickness burn wounds in children. Methods: This study was a randomized controlled trial. From June 2021 to December 2022, 78 pediatric patients with deep partial-thickness burns who met the inclusion criteria were admitted to the Department of Burns in Guiyang Steel Plant Employees Hospital. According to the random number table, the pediatric patients were divided into two groups, with 38 cases left in combined treatment group (with 20 males and 18 females, aged 26.00 (16.75, 39.75) months) and 39 cases in foam dressing group (with 21 males and 18 females, aged 19.00 (14.00, 31.00) months) after the exclusion of one dropped-out child in follow-up. The pediatric patients in combined treatment group underwent eschar dermabrasion of the wound within 48 hours after injury, the wound was covered with foam dressing after operation, and the dressing was replaced once every 7 days; for the pediatric patients in foam dressing group, the wound was sterilized within 48 hours after injury and covered with foam dressing, and the dressing was replaced once every 2 to 3 days. After the wound healing, the children in both groups were routinely applied with silicone gel twice a day for 3 weeks before started wearing elastic sleeves for more than 18 hours a day, and continuously for over than 6 months. The degree of pain during dressing change was evaluated using the children's pain behavior inventory FLACC. The adverse reactions during the treatment period, number of dressing changes, and wound healing time were observed and recorded. Six months after wound healing, the Vancouver scar scale (VSS) was used to evaluate the condition of the wound scar. Results: When changing dressing, the FLACC score for pain of pediatric patients in combined treatment group was 3.5 (2.0, 5.0), which was significantly lower than 6.0 (5.0, 8.0) in foam dressing group (Z=-5.40, P<0.05). During the treatment period, no adverse reactions such as wound edema, fluid accumulation, or peripheral skin rash allergies occurred in any pediatric patient in both groups. The number of dressing changes of pediatric patients in combined treatment group was 3 (3, 4) times, which was significantly less than 8 (7, 10) times in foam dressing group (Z=-7.58, P<0.05). The wound healing time of pediatric patients in combined treatment group was (19±5) days, which was significantly shorter than (25±6) days in foam dressing group (t=-4.48, P<0.05). Six months after wound healing, the VSS score for scar of pediatric patients in combined treatment group was 5 (2, 8), which was significantly lower than 7 (5, 10) in foam dressing group (Z=-3.05, P<0.05). Conclusions: Compared with using foam dressings alone, early eschar dermabrasion combined with foam dressings can reduce the number of dressing changes, alleviate the pain during dressing changes, and shorten the wound healing time in treating children with deep partial-thickness burns, and effectively alleviate scar hyperplasia by combining with anti-scar treatment post burns.

[Efficacy and safety of daratumumab in patients with relapsed/refractory multiple myeloma].

Objective: To investigate the efficacy and safety of daratumumab in relapsed/refractory multiple myeloma (RRMM) patients. Methods: Fifty-two RRMM patients treated with daratumumab from September 2019 to November 2021 in West China Hospital were retrospectively enrolled, including 31 males and 21 females. The mean age of these patients at the first diagnosis of multiple myeloma was (58±10) years. According to the dosage of daratumumab, patients were divided into low dosage group (n=10) and high dosage group (n=42). Overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse event rates were investigated. Univariate and multivariate analysis of potential factors were conducted. Results: Of the 52 patients, 8 received daratumumab monotherapy, 27 received daratumumab plus immuno-modulatory drug (IMiD) treatment, 4 received daratumumab plus proteosome inhibitor (PI) treatment, and 11 received daratumumab plus dexamethasone treatment. The diagnosis age of high dosage group patients was (57±9) years, which was significantly younger than that of low dosage group [(66±10) years] (P=0.009). The baseline creatinine level of high dosage group patients [M (Q1, Q3)] was 91 (68, 196) µmol/L, which was significantly higher than that of low dosage group [66 (51, 76) µmol/L] (P=0.021). There was no significant difference in other baseline clinical characteristics, previous treatment regimens, previous lines of treatment, and regimen and cycles of daratumumab between the high dosage group and low dosage group (all P>0.05). The ORR for the 52 patients was 71.2% (37/52). The ORR for daratumumab plus IMiD group was 81.5% (22/27), which was significantly higher than that in monotherapy or dexamethasone group [ORR: 52.6% (10/19), P=0.036). With a median follow-up [M (Q1, Q3)] of 7 (5, 26) months, the median PFS for overall cohort was 17 (95%CI: 9.6-24.4) months. The median PFS for daratumumab plus IMiD group was 26 (95%CI: 6.0-46.0) months, which was significantly better than that in monotherapy or dexamethasone group [12 (95%CI: 3.5-20.5) months] (HR=0.231, 95%CI: 0.075-0.715, P=0.011). Higher diagnosis age was the risk factor of progression (HR=1.085, 95%CI: 1.016-1.158, P=0.014), while more cycles of daratumumab treatment was the protective factor of progression (HR=0.669, 95%CI: 0.495-0.904, P=0.009). There was no significant influence of daratumumab dosage on progression (high dosage vs low dosage, HR=1.016, 95%CI: 0.221-4.668, P=0.984). The median OS for overall cohort was 26 (95%CI: 13.1-38.9) months. Higher serum calcium was the independent risk factor of death (HR=12.190, 95%CI: 1.170-127.048, P=0.037). There was no significant influence of daratumumab dosage on death (high dosage vs low dosage, HR=0.818, 95%CI: 0.171-3.917, P=0.802). Adverse events included infections (43.2%, 16/37), infusion-associated reactions (29.7%, 11/37), and thrombocytopenia (27.0%, 10/37). Conclusions: Daratumumab is effective to treat RRMM. The dosage of daratumumab has no significant influence on prognosis when used in combined treatment. The incidence of adverse events is relatively low, with a favorable safety profile.

[Cannabis use among the drug users with compulsory detained detoxification treatment in China].

OBJECTIVE: To explore the epidemic situation of cannabis use among drug users with compulsory detained detoxification treatment in China. METHODS: Using the data from the Drug Abuse Population Estimation in the Key Cities of the Ministry of Public Security, we analyzed the sociodemographic characteristics and substance use of cannabis abusers with compulsory detained detoxification treatment in 55 provincial capital cities and key cities of China. Chi-square test, Fisher exact test and Kruskal-Wallis rank sum test were used to compare the prevalence of cannabis, heroin, synthetic and mixed drug use among patients with detoxification treatment, as well as the differences in polydrug use and areas among cannabis users. RESULTS: In the study, 25 366 drug users with compulsory detained detoxification treatment were recruited, of whom 2.2% (546/25 366) used cannabis in the previous year before the treatment. The proportion of males was 83.5%, and the proportion of ethnic minorities was 41.0%. Those who received junior high school education or above accounted for 30.8%, and the unemployed accounted for 44.1%. The average age was (33.3±8.2) years, the average age of beginning drug use was (24.8±7.7) years, and the average duration between the first drug abuse and first detoxification treatment was (5.4±4.6) years. The prevalence of cannabis use was higher among those drug users who were 35-year-old and younger, ethnic minorities, employees and residents in Xinjiang. Of the cannabis users, 91.4% used polydrug, 13.6% combined with heroin alone, 42.1% combined with synthetic drugs alone and 35.7% combined with both of heroin and synthetic drugs. Of the cannabis users, 49.6% came from 3 regions: Xinjiang Uygur Autonomous Region, Jiangsu Province and Shanghai City. The cannabis users in Xinjiang had a high proportion of ethnic minorities who received junior high school education and below. Moreover, 79.6% of them combined cannabis use with heroin. The cannabis users in Jiangsu, Zhejiang and Shanghai areas had a higher proportion of ethnic Han who received better education (high school and above). Moreover, 92.7% of them combined cannabis use with methamphe-tamine. CONCLUSION: The prevalence of cannabis use among the population with compulsory detained detoxification treatment is higher than that among drug users under surveillance, but there are obvious regional cluster effect and high possibility of polydrug abuse. Thus, it's important to strengthen the monitoring of cannabis use, to increase the control of cannabis and to formulate China's anti-cannabis policy among different population.

Investigations on the complex flows induced by dual-swept/dual-ramp wedges in supersonic flows.

The caret inlet with a dual-swept/dual-ramp configuration has excellent stealth performance and aerodynamic capability. Most previous investigations on this configuration have focused on experiments and numerical simulations but there are relatively few theoretical investigations. In this study, the flow field characteristics of dual-swept/dual-ramp configuration are investigated analytically and numerically. An analytical approach that combines the shock dynamics with a "spatial dimension reduction" was used to analyze the characteristics of the wave structures and state parameters of the flow field. The effects of the sweep angles and inflow Mach number on the flow field characteristics are investigated. The results indicate that the problem of shock/shock interaction in two intersecting wedges of large back-swept angle is a problem of weak shock interaction. Therefore, the theory of weak shock interaction is used to investigate the flow field characteristics, including the uniformity of the flow field and the total pressure recovery performance.

Cobalt disulfide-modified cellular hierarchical porous carbon derived from bovine bone for application in high-performance lithium-sulfur batteries.

Improving the insulating nature of sulfur and retaining the soluble polysulfides in sulfur cathodes are crucial for realizing the practical application of lithium-sulfur batteries (LSBs). Biomass-based carbon is becoming increasingly popular for fabricating economical and efficient cathodes for LSBs owing to its unique structure. Herein, we report a facile strategy to transform bovine bone with an organic-inorganic structure into cellular hierarchical porous carbon via carbonization and KOH activation, followed by CoS2 modification through hydrothermal treatment. The synthesized composite can load abundant sulfur and produce a dual effect of "physical confinement and chemical entrapment" on polysulfides. The conductive carbon frame with the developed porous structure provides adequate space to accommodate sulfur and physically suppress the shuttle effect of polysulfides. The embedded half-metallic CoS2 sites can chemically anchor the polysulfides and enhance the electrochemical reaction activity as well. Owing to the multifunctional structure and dual restraint effect, the designed electrode exhibits enhanced electrochemical properties including high initial capacity (1230.9 mAh g-1 at 0.2 C), improved cycling stability and enhanced rate capability.

Expressions of IL-1α and MMP-9 in degenerated lumbar disc tissues and their clinical significance.

OBJECTIVE: To observe the expression levels of interleukin-1α (IL-1α) and matrix metalloproteinase-9 (MMP-9) in degenerated lumbar disc tissues and to investigate their clinical significance. PATIENTS AND METHODS: Fifty patients with lumbar disc degeneration received the operative treatment were divided into three groups according to the magnetic resonance imaging (MRI) results: protrusion group, extrusion group, and free group. The degenerated intervertebral disc tissues were taken, and the normal intervertebral disc tissues of 20 patients received the operative treatment due to lumbar bursting fracture, and were selected as the control group. The bone mineral densities of all patients were measured. The mRNA and protein expression levels of MMP-9 and IL-1α were detected via Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: The bone mass of patients with lumbar disc degeneration was significantly decreased compared with that of the control group, and the bone mass was decreased more significantly in a free group than that in protrusion group. The mRNA and protein levels in IL-1α and MMP-9 of patients with lumbar disc degeneration were significantly increased compared with those in control group; the mRNA and protein levels in IL-1α and MMP-9 of extrusion group and free group were significantly higher than those in protrusion group, and the mRNA and protein levels in IL-1α and MMP-9 of free group were significantly higher than those in extrusion group. CONCLUSIONS: The levels of IL-1α and MMP-9 in degenerated lumbar disc tissues are higher than normal levels, and the increasing levels are positively correlated with the disease condition.

Lower eyelid reconstruction following a traumatic full thickness loss.

Eyelid reconstruction is complex and challenging since it is not only for structural and functional restoration, but also for an acceptable aesthetic result. In full thickness eyelid injuries, it will involve both anterior and posterior lamella. Therefore, when reconstructing the defect, it requires at least two layers; one will be a flap with blood supply, and the other can be a free graft. In this case, a rotational advancement cheek flap and composite graft were used to reconstruct the lower eyelid.

[Clinical and immunological analysis of patients with activated phosphoinositide 3-kinase δ syndrome resulting from PIK3CD mutation].

Objective: To explore the clinical and immunological features, gene mutations, treatment and prognosis in patients with activated phosphoinositide 3-kinase δ syndrome (APDS) caused by PIK3CD gene heterozygous germline mutation. Method: The data of clinical, immunological phenotype, treatment, and prognosis of 15 patients with APDS, who visited Children's Hospital of Chongqing Medical University, Peking Union Medical College Hospital, and Shenzhen Children's Hospital from June 2014 to November 2016, were collected and analyzed. Result: Of the 15 patients, 11 were males, remaining 4 patients were females. The median age of disease onset was 1 year, and median age at diagnosis was 4 years and 4 months. All patients had the de novo heterozygous germline mutation in PIK3CD (c. 3061G>A, p. E1021K). The common initial symptoms were respiratory infections, including pneumonia (12 cases) , bronchiectasis (5 cases). Other common clinical manifestations were recurrent and chronic diarrhea (11 cases), Epstein-Barr virus (EBV) and/or cytomegalovirus (CMV) viremia (10 cases), hepatosplenomegaly (13 cases), and lymphadenopathy (10 cases). The main immunological features were increased IgM (11 cases), decreased IgG (6 cases), decreased numbers of CD4+ T cell (7 cases) especially naïve CD4+ T cell (9 cases), reduced numbers of B cells (11 cases) particularly naïve B cells (9 cases), increased numbers of transitional B cells (5 cases) and CD8+ terminally differentiated effector memory T cells (5 cases). After 1-29 months follow up, 13 of the 15 cases remain survived, of whom 5 cases received regular intravenous immunoglobulin (IVIG) therapy, with reduced frequency of infections and improved severity of infections; of whom 3 cases received oral rapamycin therapy at the dosage of 1 mg/ (m2·d) and with a decrease in nonneoplastic lymphoproliferation. Conclusion: E1021K is a hotspot for mutation in the PIK3CD gene in patients with APDS. Regular IVIG can improve their quality of life. Targetel treatment with rapamycin could mitigate hepatosplenomegaly.

Biodegradation of phthalate esters by newly isolated Rhizobium sp. LMB-1 and its biochemical pathway of di-n-butyl phthalate.

AIMS: To isolate a novel strain that could degrade many kinds PAEs efficiently and investigate the DBP-degrading pathway in this strain. METHODS AND RESULTS: Based on its 16S rRNA gene sequence, the strain was identified as Rhizobium sp. This strain, named LMB-1, can also utilize phthalates, such as DEHP, DMP, DBP and DEP. During the degradation of DBP, six possible metabolites, diethyl phthalate, mono-ethyl phthalate, di-methyl phthalate, mono-methyl phthalate, phthalic acid and tartaric acid, were identified by gas chromatography-mass spectrometry (GC-MS) analysis, and the degradation pathway of DBP was also identified in this study. CONCLUSIONS: In summary, strain LMB-1, identified as Rhizobium sp., was found to be capable of efficiently degrading PAEs, and it was determined that the strain degraded DMP completely within 45 h. DEP, DMP, MEP, MMP, PA and tartaric acid were detected during the course of DBP degradation by LMB-1. We propose that this strain could completely degrade DBP or other PAEs. Our results offer a novel and potential candidate, Rhizobium sp. LMB-1, for use in the bioremediation of cultivated soil contaminated by PAEs. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report concerning the complete degradation of phthalate esters by Rhizobium sp.

Changes of inter-hemispheric functional connectivity between motor cortices after brachial plexuses injury: a resting-state fMRI study.

OBJECT: The aim of this study is to explore the changes of inter-hemispheric functional connectivity in patients with unilateral brachial plexus injury. METHODS: Nine patients with five roots of unilateral brachial plexus avulsion injury and 11 healthy controls were recruited in this study. Resting-state functional connectivity magnetic resonance image was used to study the differences of inter-hemispheric functional connectivity between patients and healthy controls. Four areas were defined as regions of interest (ROI): the two primary motor areas (M1 areas) and two supplementary motor areas (SMAs) in the two hemispheres activated when the healthy controls performed unilateral hand grasping movement of the two hands, respectively. Functional connectivity maps were generated by correlating the regional time course of each ROI with that of every voxel in the whole brain. Then, functional connectivity was calculated by correlating the functional magnetic resonance image signal time courses of every two ROIs. RESULTS: Resting-state inter-hemispheric functional connectivity of the primary motor areas was reduced following brachial plexus avulsion injury. The correlation coefficients of the SMAs showed no difference between the brachial plexus patients and healthy volunteers. CONCLUSIONS: Our results indicate that brachial plexus injury decreases resting-state inter-hemispheric functional connectivity of the two primary motor areas. These results provide new insight into functional reorganization of the cerebral cortex after brachial plexus injury.

Exercise intervention may prevent depression.

Physical activity is an effective component of depression management. However, the mechanisms by which exercise affects behavioral disorders remain unclear. The present study was conducted to investigate mechanisms by which voluntary exercise ameliorates depression. Plasma cortisol levels and hippocampal monoamine neurotransmitters were measured. Chronic mild stress (CMS) was used to induce depression in a rat model. The rats were allowed to swim for 10 weeks as part of their exercise treatment. Depressive behavior was analyzed using an open-field test and a sucrose consumption test before and after exercise. Serum cortisol levels were measured by radioimmunoassay. The concentrations of monoamine neurotransmitters in the hippocampus were determined using high-performance liquid chromatography with electrochemical detection. The CMS rats showed behavioral improvement after exercise. Compared with the control, serum cortisol levels were significantly increased by CMS. The serotonin, dopamine, and norepinephrine levels in the hippocampi were significantly increased by exercise. These findings indicate that exercise reverses and prevents the decrease in serotonin and noradrenaline, and restores dopamine in the CMS model.

Pineal parenchymal tumours: minimum apparent diffusion coefficient in prediction of tumour grading.

Retrospective assessment was performed of the minimum apparent diffusion coefficient (minADC) together with quantitative assessment of the histopathological features of resected tumour tissue and the Ki-67 labelling index (LI) for predicting pineal parenchymal tumour (PPT) grade. Magnetic resonance images of tumours from 26 male and female patients (mean age 27.7 years) with pathologically confirmed PPTs, comprising 10 pineocytomas (PCs), seven pineal parenchymal tumours of intermediate differentiation (PPTIDs) and nine pineoblastomas (PBs), were reviewed retrospectively. Using ADC maps derived from isotropic diffusion-weighted images, the minADC value of each tumour was determined postoperatively from several regions of interest defined in the tumour, excluding cystic, necrotic, haemorrhagic or calcified components. Surgical intervention was undertaken in all cases. The Ki-67 LI was measured in surgical specimens. Mean minADC and Ki-67 LI showed significant differences among PCs, PPTIDs and PBs, and minADC was negatively correlated with Ki-67 LI. It is concluded that the minADC of PPTs provide useful additional information when predicting tumour grading.

Bacterial foraging algorithm with varying population.

Most of evolutionary algorithms (EAs) are based on a fixed population. However, due to this feature, such algorithms do not fully explore the potential of searching ability and are time consuming. This paper presents a novel nature-inspired heuristic optimization algorithm: bacterial foraging algorithm with varying population (BFAVP), based on a more bacterially-realistic model of bacterial foraging patterns, which incorporates a varying population framework and the underlying mechanisms of bacterial chemotaxis, metabolism, proliferation, elimination and quorum sensing. In order to evaluate its merits, BFAVP has been tested on several benchmark functions and the results show that it performs better than other popularly used EAs, in terms of both accuracy and convergency.

Amyloid beta-degrading cryptidases: insulin degrading enzyme, presequence peptidase, and neprilysin.

The accumulation of aggregates of amyloidogenic peptides is associated with numerous human diseases. One well studied example is the association between deposition of amyloid beta (Abeta) and Alzheimer's disease. Insulin degrading enzyme and neprilysin are involved in the clearance of Abeta, and presequence peptidase is suggested to play a role in the degradation of mitochondrial Abeta. Recent structural analyses reveal that these three peptidases contain a catalytic chamber (crypt) that selectively encapsulates and cleaves amyloidogenic peptides, hence the name cryptidase. The substrate selectivity of these cryptidases is determined by the size and charge distribution of their crypt as well as the conformational flexibility of substrates. The interaction of Abeta with the catalytic core of these cryptidases is controlled by conformational changes that make the catalytic chambers accessible for Abeta binding. These new structural and biochemical insights into cryptidases provide potential therapeutic strategies for the control of Abeta clearance.

Fine mapping of a major quantitative trait loci, qSSP7, controlling the number of spikelets per panicle as a single Mendelian factor in rice.

In our previous studies, one putative QTL affecting number of spikelets per panicle (SPP) was identified in the pericentromeric region of rice chromosome 7 using a recombinant inbred population. In order to define the QTL (qSPP7), RI50, a recombinant inbred line with 70% of genetic background same as the female parent of Zhenshan 97, was selected to produce near-isogenic lines for the target region in the present study. In a BC(2)F(2) population consisting of 190 plants, the frequency distribution of SPP was shown to be discontinuous and followed the expected Mendelian ratios (1:2:1 by progeny test) for single locus segregation. qSPP7 was mapped to a 0.4 cM region between SSR marker RM3859 and RFLP marker C39 based on tests of the BC(2)F(2) population and its progeny. Its additive and dominant effects on SPP were 51.1 and 24.9 spikelets, respectively. Of great interest, the QTL region also had effects on grain yield per plant (YD), 1,000 grain weight (GW), tillers per plant (TPP) and seed setting ratio (SR). Significant correlations were observed between SPP and YD (r = 0.66) and between SPP and SR (r = -0.29) in the progeny test. 1082 extremely small panicle plants of a BC(3)F(2) population containing 8,400 individuals were further used to fine map the QTL. It turns out that qSPP7 co-segregated with two markers, RM5436 and RM5499 spanning a physical distance of 912.4 kb. Overall results suggested that recombination suppression occurred in the region and positional cloning strategy is infeasible for qSPP7 isolation. The higher grain yield of Minghui 63 homozygote as compared to the heterozygote suggested that Minghui 63 homozygote at qSPP7 in hybrid rice could further improve its yield.

Crystallization and preliminary X-ray study of the edema factor exotoxin adenylyl cyclase domain from Bacillus anthracis in the presence of its activator, calmodulin.

Edema factor from Bacillus anthracis is a 92 kDa secreted adenylyl cyclase exotoxin and is activated by the host-resident protein calmodulin. Calmodulin is a ubiquitous intracellular calcium sensor in eukaryotes and activates edema factor nearly 1000-fold upon binding. While calmodulin has many known effectors, including kinases, phosphodiesterases, motor proteins, channels and type 1 adenylyl cyclases, no structures of calmodulin in complex with a functional enzyme have been solved. The crystallization and initial experimental phasing of crystals containing a complex of edema factor adenylyl cyclase domain and calmodulin are reported here. The edema factor-calmodulin complex crystallizes in three different space groups. A native data set in the I222 space group has been collected to 2.7 A and the self-rotation function solution suggests three edema factor-calmodulin complexes in each asymmetric unit. Initial 4 A phases were obtained by selenomethionyl MAD in combination with two heavy-atom derivatives. These phases were successfully extended to 2.7 A using NCS averaging.

The regulation of type 7 adenylyl cyclase by its C1b region and Escherichia coli peptidylprolyl isomerase, SlyD.

Mammalian membrane-bound adenylyl cyclase consists of two highly conserved cytoplasmic domains (C1a and C2a) separated by a less conserved connecting region, C1b, and one of two transmembrane domains, M2. The C1a and C2a domains form a catalytic core that can be stimulated by forskolin and the stimulatory G protein subunit alpha (Galpha(s)). In this study, we analyzed the regulation of type 7 adenylyl cyclase (AC7) by C1b. The C1a, C1b, and C2a domains of AC7 were purified separately. Escherichia coli SlyD protein, a cis-trans peptidylprolyl isomerase (PPIase), copurifies with AC7 C1b (7C1b). SlyD protein can inhibit the Galpha(s)- and/or forskolin-activated activity of both soluble and membrane-bound AC7. Mutant forms of SlyD with reduced PPIase activity are less potent in the inhibition of AC7 activity. Interestingly, different isoforms of mammalian membrane-bound adenylyl cyclase can be either inhibited or stimulated by SlyD protein, raising the possibility that mammalian PPIase may regulate enzymatic activity of mammalian adenylyl cyclase. Purified 7C1b-SlyD complex has a greater inhibitory effect on AC7 activity than SlyD alone. This inhibition by 7C1b is abolished in a 7C1b mutant in which a conserved glutamic acid (amino acid residue 582) is changed to alanine. Inhibition of adenylyl cyclase activity by 7C1b is further confirmed by using 7C1b purified from an E. coli slyD-deficient strain. This inhibitory activity of AC7 is also observed with the 28-mer peptides derived from a region of C1b conserved in AC7 and AC2 but is not observed with a peptide derived from the corresponding region of AC6. This inhibitory activity exhibited by the C1b domain may result from the interaction of 7C1b with 7C1a and 7C2a and may serve to hold AC7 in the basal nonstimulated state.

Inhibition of adenylyl and guanylyl cyclase isoforms by the antiviral drug foscarnet.

The pyrophosphate (PP(i)) analog foscarnet inhibits viral DNA-polymerases and is used to treat cytomegalovirus and human immunodeficiency vius infections. Nucleotide cyclases and DNA-polymerases catalyze analogous reactions, i.e. a phosphodiester bond formation, and have similar topologies in their active sites. Inhibition by foscarnet of adenylyl cyclase isoforms was therefore tested with (i) purified catalytic domains C1 and C2 of types I and VII (IC1 and VIIC1) and of type II (IIC2) and (ii) membrane-bound holoenzymes (from mammalian tissues and types I, II, and V heterologously expressed in Sf9 cell membranes). Foscarnet was more potent than PP(i) in suppressing forskolin-stimulated catalysis by both, IC1/IIC2 and VIIC1/IIC2. Stimulation of VIIC1/IIC2 by Galpha(s) relieved the inhibition by foscarnet but not that by PP(i). The IC(50) of foscarnet on membrane-bound adenylyl cyclases also depended on their mode of regulation. These findings predict that receptor-dependent cAMP formation is sensitive to inhibition by foscarnet in some, but not all, cells. This was verified with two cell lines; foscarnet blocked cAMP accumulation after A(2A)-adenosine receptor stimulation in PC12 but not in HEK-A(2A) cells. Foscarnet also inhibited soluble and, to a lesser extent, particulate guanylyl cylase. Thus, foscarnet interferes with the generation of cyclic nucleotides, an effect which may give rise to clinical side effects. The extent of inhibition varies with the enzyme isoform and with the regulatory input.

An extended conformation of calmodulin induces interactions between the structural domains of adenylyl cyclase from Bacillus anthracis to promote catalysis.

The edema factor exotoxin produced by Bacillus anthracis is an adenylyl cyclase that is activated by calmodulin (CaM) at resting state calcium concentrations in infected cells. A C-terminal 60-kDa fragment corresponding to the catalytic domain of edema factor (EF3) was cloned, overexpressed in Escherichia coli, and purified. The N-terminal 43-kDa domain (EF3-N) of EF3, the sole domain of edema factor homologous to adenylyl cyclases from Bordetella pertussis and Pseudomonas aeruginosa, is highly resistant to protease digestion. The C-terminal 160-amino acid domain (EF3-C) of EF3 is sensitive to proteolysis in the absence of CaM. The addition of CaM protects EF3-C from being digested by proteases. EF3-N and EF3-C were expressed separately, and both fragments were required to reconstitute full CaM-sensitive enzyme activity. Fluorescence resonance energy transfer experiments using a double-labeled CaM molecule were performed and indicated that CaM adopts an extended conformation upon binding to EF3. This contrasts sharply with the compact conformation adopted by CaM upon binding myosin light chain kinase and CaM-dependent protein kinase type II. Mutations in each of the four calcium binding sites of CaM were examined for their effect on EF3 activation. Sites 3 and 4 were found critical for the activation, and neither the N- nor the C-terminal domain of CaM alone was capable of activating EF3. A genetic screen probing loss-of-function mutations of EF3 and site-directed mutations based on the homology of the edema factor family revealed a conserved pair of aspartate residues and an arginine that are important for catalysis. Similar residues are essential for di-metal-mediated catalysis in mammalian adenylyl cyclases and a family of DNA polymerases and nucleotidyltransferases. This suggests that edema factor may utilize a similar catalytic mechanism.

[A hanger-needless infusion set and it's unique infusion tube].

The design of an enclosed barrel with an interiorly compresed plunges is introduced in the paper. With a unique floating-bulb-design tube, the new infusion set makes liquid infusion easy at any height, in any direction, with no need of hanger and without any risk of theleast possibility of any air into blood vessels. It is suitable for prehospital rescue, battle field treatment and wounded Rersonnels' transpostation etc. The new infusion set can also be tailored or improved according to the different requirements of usess and clinical applications.