Suggested blood donor deferral strategy regarding hepatitis B infections in China.

BACKGROUND: Hepatitis B virus (HBV) reactivity in individual immunologic and nucleic acid tests (NAT) tests does not represent the true infectious status of the blood donor. This study discusses the use of confirmatory tests to determine when deferral of blood donors is appropriate. METHODS: HBsAg or HBV NAT reactive samples were confirmed via a neutralisation test. All the HBsAg reactive but neutralisation test negative samples were subjected to further anti-HBc testing. The receiver operating characteristic curve was used to obtain the best threshold value using signal-to-cut-off ratios of two HBsAg enzyme-linked immunosorbent assay reagents. RESULTS: Of the 780 HBV reactive samples collected, there were 467 HBsAg reactive but HBV DNA negative samples, of which 65 (13.92%) and 402 (86.08%) were neutralisation test positive and negative, respectively. Of the 402, 91 samples (30% of tested samples) were anti-HBc reactive. HBV DNA positive specimens negative by virus neutralisation were >80% HBcAg positive. A screening strategy was proposed for Chinese blood collection agencies. CONCLUSION: These findings suggest that adopting a screening algorithm for deferring HBV reactive blood donors based on HBsAg and NAT testing followed with HBsAg S/CO consideration and HBcAg testing can be both safe and feasible in China.

Computed Tomography Study of the Retrosigmoid Craniotomy Keyhole Approach Using Surface Landmarks.

Background: Due to a lack of accessibility and individual differences in surgical procedures, many previous studies on keyholes are not practical. Objective: To study the surface landmarks for optimal keyhole placement in the retrosigmoid approach. Methods: The three-dimensional (3D) skull images of 79 patients were reconstructed using workstations, with a total of 149 hemiskull base 3D images then analyzed. Skull-surface landmarks were marked, the lateral-skull surface was observed, and the positional relationships between the asterion and the extension line of the posterior margin of the mastoid process were measured. The position of the superior curvature of the sigmoid sinus groove was located before it was projected onto the lateral surface of the skull and defined as the keypoint. The positional relationship between the keypoint and the skull-surface landmarks was observed in an established coordinate system using spatial proportion relationships. Results: The asterion was located around the extension line of the posterior margin of the mastoid process, and the vertical distance from the extension line was <15 mm. It was found that 93.29% (139/149) of the keypoints were located in a 7 mm radius circle, with the center at (-0.41, -3.01) in the coordinate system in the 3D computed tomography images. Conclusion: When using this method, the spatial proportion relationship of the anatomical marks can accurately locate keyholes, therefore providing technical support when employing the retrosigmoid approach.

Safety and Tolerability of Omalizumab in Children with Allergic (IgE-Mediated) Asthma: A Systematic Review and Meta-Analysis.

BACKGROUND: Omalizumab is a recombinant humanized monoclonal antibody against immunoglobulin E., which can specifically bind to IgE in blood and inhibit the release of inflammatory mediators to improve the symptoms of IgE-mediated asthma effectively. This meta-analysis was used to retrieve the studies in recent years to provide a clinical reference for the omalizumab in treating allergic asthma (AA). METHODS: The databases Ovid, Embase, Pubmed, the Cochrane Library of clinical trials, CNKI (China National Knowledge Infrastructure) (China), and Wangfang Data (China) were searched for all studies on omalizumab involvement in treating allergic childhood asthma up to January 2022. Effectiveness, rate of exacerbation within 24 weeks (and 52 weeks), and the incidence of adverse reactions and serious adverse reactions were used as the primary data analysis indicators. RESULTS: Seven eligible pieces of literature were included. Meta-analysis indicated that omalizumab could significantly improve the treatment efficacy in children with asthma [RR (Risk Ratio) = 1.24, 95% CI (Confidential Interval) (1.09, 1.41), Z = 3.30, p = 0.001], reduced the incidence of significant clinical exacerbation in children with asthma within 24 weeks [RR = 0.55, 95% CI (0.35, 0.85), Z = -2.67, p = 0.001], reduced the incidence of significant clinical exacerbation in children with asthma within 52 weeks [RR = 0.52, 95% CI (0.39, 0.71), Z = -4.2, p < 0.0001], and the incidence of total serious adverse reactions was not statistically different from placebo [RR = 1.00, 95% CI (0.98, 1.03), Z = 0.71, p = 0.479], the incidence of serious adverse reactions was significantly decreased [RR = 0.53, 95% CI (0.36, 0.77), Z = -3.35, p = 0.001]. CONCLUSIONS: In treating IgE (immunoglobulin E)-mediated asthma in children, adding oral (or subcutaneous) omalizumab to a glucocorticoid regimen can enhance the effectiveness of treatment, reduce the probability of significant exacerbation during treatment, and reduce the incidence of serious adverse reactions.

Physiological and molecular responses to hypoxia stress in Manila clam Ruditapes philippinarum.

Hypoxia has become one of the major environmental problems in the aquaculture industry. As one of the most commercially important bivalves, Manila clam Ruditapes philippinarum may be suffering substantial mortality attributable to hypoxia. The physiological and molecular responses to hypoxia stress in Manila clam were evaluated at two levels of low dissolved oxygen: 0.5 mg/L (DO 0.5 mg/L) and 2.0 mg/L (DO 2.0 mg/L). With the prolongation of hypoxia stress, the mortality rate was 100% at 156 h under DO 0.5 mg/L. In contrast, 50% of clams survived after 240 h of stress at DO 2.0 mg/L. After the hypoxia stress, some severe structural damages were observed in gill, axe foot, hepatopancreas tissues, such as cell rupture and mitochondrial vacuolization. For the hypoxia-stressed clams, the significant rise and decline of enzyme activity (LDH and T-AOC) was observed in gills, in contrast to the reduction of glycogen content. Furthermore, the expression levels of genes related to energy metabolism (SDH, PK, Na+/K+-ATPase, NF-κB and HIF-1α) was significantly affected by the hypoxia stress. It is therefore suggested that the short-term survival of clams under hypoxia may be dependent on stress protection by antioxidants, energy allocation, and tissue energy reserves (such as glycogen stores). Despite this, the prolongation of hypoxia stress at DO 2.0 mg/L may cause the irreversible damages of cellular structures in clam tissues, eventually leading to the death of clams. We therefore support the hypothesis that the extent of hypoxia impacts on marine bivalves may be underestimated in the coastal areas.

Macrophthalmus (Macrophthalmus) abbreviatus Manning & Holthuis, 1981, a new natural host for Hematodinium perezi infection.

Recent reports have shown that wild crabs may be important hosts involved in the transmission and spread of the parasitic Hematodinium in cultured marine crustaceans. Therefore, monitoring the prevalence of Hematodinium infections in wild crabs is necessary to develop effective strategies for the prevention and control of Hematodinium disease. Here we report a wild crab species, Macrophthalmus (Macrophthalmus) abbreviatus Manning & Holthuis, 1981, as a new natural host for Hematodinium sp. infection. It is one of the common wild crab species dwelling in the ponds or waterways connected to the polyculture ponds located on the coast of Rizhao or Weifang, Shandong Peninsula, China. According to the results of PCR detection and phylogenetic analysis targeting the internal transcribed spacer 1 (ITS 1) region, these Hematodinium sp. isolates were identified as H. perezi and fell into the genotype II category within H. perezi. A high monthly prevalence of H. perezi infection was observed during the 2021-2022 field survey, ranging from 33.3% to 90.6% in M. abbreviatus originating from Weifang (n=304 wild crabs) and from 53.6% to 92.9% in those from Rizhao (n=42 wild crabs). Artificial inoculation infection experiments demonstrated that M. abbreviatus could be infected by H. perezi, and massive Hematodinium cells and typical histopathological changes were observed in the hepatopancreas and gill tissues of the infected crabs. To our knowledge, this is the first report of M. abbreviatus as a new natural host for H. perezi infection. Results in the present study extend the known host spectrum for this emerging parasite pathogen, and also provide valuable information for epidemic surveillance of the Hematodinium disease as well.

Diphtheria Toxin/Human B-Cell Activating Factor Fusion Protein Kills Human Acute Lymphoblastic Leukemia BALL-1 Cells: An Experimental Study.

OBJECTIVE: This study aimed to express a fusion protein of diphtheria toxin and human B cell-activating factor (DT388sBAFF) in Escherichia coli (E. coli) and investigate its activity in human B-lineage acute lymphoblastic leukemia 1 cells (BALL-1). METHODS: A fragment of DT388sBAFF fusion gene was separated from plasmid pUC57-DT388sBAFF digested with Nde I and Xho I, and inserted into the expression vector pcold II digested with the same enzymes. Recombinants were screened by the colony polymerase chain reaction (PCR) and restriction map. The recombinant expression vector was transformed into BL21 and its expression was induced by isopropyl ß-D-1-thiogalactopyranoside (IPTG). The recombinant protein was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot, and then purified by Ni(2+)-NTA affinity chromatography. The expression level of B cell-activating factor receptor (BAFF-R) on BALL-1 cells was assessed by real-time PCR. The receptor binding capacity of recombinant protein was determined by cell fluorescent assay. The specific cytotoxicity of recombinant protein on BALL-1 cells was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The expression level of recombinant protein was 50% of total bacterial proteins in E. coli, and the recombinant protein could bind to BAFF-R-positive BALL-1 cells and thereby produce a cytotoxic effect on the cells. CONCLUSION: The fusion protein expression vector DT388sBAFF was successfully constructed and the recombinant protein with selective cytotoxicity against BALL-1 cells was obtained, providing foundation for further study of the therapy of human B-lineage acute lymphoblastic leukemia.

Price Decision-Making in Dual-Channel Healthcare Services Supply Chain Considering the Channel Acceptance, Price Ceiling, and Public Welfare.

Given that an increasing number of online healthcare channels play an essential role as a supply method in the healthcare service supply chain (HSSC), this paper studies the price decision-making problem for a dual-channel HSSC considering the channel acceptance, price ceiling, and public welfare. In this HSSC, a healthcare institution establishes both a traditional offline channel and an online channel to provide healthcare services for some health conditions. Considering the public welfare of healthcare institutions, we employ a sum formula of economic revenue and patient surplus to describe the total revenue of both healthcare service channels. Based on the Stackelberg game, we develop a decentralized supply chain model to maximize supply chain members' revenue. By employing the Karush-Kuhn-Tucker optimality condition, we derive an analytical expression for the optimal service price, which includes the functions of the public welfare coefficient and channel acceptance. Finally, we conduct extensive numerical analyses under various system parameters to verify the optimal price decision-making strategies. Our analytical results indicate that: (1) the healthcare service price is closely related to the patients' channel acceptance, the public welfare coefficient, and the government price ceiling policy; (2) the public welfare coefficient strongly influences the service price and total revenue, and its increase can decrease the economic revenue of the HSSC; (3) the acceptance of online channels is an essential factor that should be carefully considered in the construction of a dual-channel HSSC. Improving patient acceptance of online channels is conducive to developing and improving a sustainable dual-channel HSSC.

[Establishing the Blood Donor Deferral Criterion in TP ELISA Test].

OBJECTIVE: To Establish the shielding threshold value of TP antibody ELISA for unpaid blood donors, so as to shield true positive blood donors from returning to team management. METHODS: The real serological status of 517 samples with anti-TP ELISA reactivity was determined by confirmation test of Treponema pallidum particle agglutination (TPPA). The shielding threshold of TP antibody was preliminarily determined by using 99% specificity of ROC and 95% positive predictive value of percentile method, respectively. 283 TP antibody reactivity specimens routinely tested in our laboratory were selected to determine the applicability of the initial shielding values obtained by the two methods, and finally to determine the shielding threshold values of TP antibody donors. RESULTS: The specific S/CO values of reagent A 99% were 13.33-16.18, that of reagent B 99% was 6.34, that of reagent B 99% was 13.17-19.85, and that of 95% was 6.62. Empirical evidence: 99% specific threshold shielding true positive rates of reagents A and B were 100%, 95% positive expected value shielding true positive rates were 98.4%, 99%. Final determination of 99% specific shielding threshold as a low value of blood donors shielding threshold. The shielding limits of reagent A and B were 13.33 and 13.17. CONCLUSION: The shielding threshold of TP antibody ELISA for blood donors established in this study can help to reduce the number of blood donors returning to team management.

[Evaluation of the Cutoff of Anti-HCV Antibody Enzyme-Linked Immunosorbent Assay in 7 Blood Station Laboratories].

OBJECTIVE: To evaluate the necessity and suitability of the anti-HCV ELISA teot gray zone setted up by 7 blood station laboratories. METHODS: 7 blood station laboratories were coded as 1, 2, 3, 4, 5, 6 and 7 respectively; 8 kinds of ELISA reagents were coded as A, B, C, D, E, F, G and H respectively. 1 or 2 of 8 ELISA reagents produced by different manufactories were used to detect the anti-HCV in specimens of same group by 7 blood station laboratories; the Westen blot was used to detect the specimens with difference of detected results so as to difine the serological status of specimens. The true positive rate of specimens detected by laboratories and gray zone-comfirined positive rate of specimens were accounted so as to analyze the necessity of setting up the gray zone for anti-HCV ELISA test of 7 blood station laboratories; the optimal cut-off value for anti-HCV ELISA test was determined in 7 blood station laborafories by ROC curve and the changes of sensitivity and specificity of 3 different cut-off value(laboratory work cut-off value, manifactory-recommended cun-off value and optimal cut-off value) were compared so as to analyze the suitability of gray zone for anti-HCV ELISA test in 7 blood station laboratories. RESULTS: The true positive rate detected by 7 blood station laboratories, out of which coded 1 laboratory used 2 kinds of coded A, B reagents was 95.40%(1A), 99.23% (1B), 94.25% (2C), 96.17% (3D), 98.08% (4E), 96.93% (5F), 97.32%(6G) and 93.10%(7H). Except for 2C(94.25%) and 7H(93.10%), the true positive rate detected by laboratoies which not sutted up gray zone, the gray zone-con-firmed positive rate in 6 blood station laboratories setted up gray zone: was 0.00%, 0.00%, 21.43%, 0.00%, 0.00%, 0.00% and 38.89%. The comparison of 3 different cut-off valuces by ROC curve showed that the anti-HCV cut-off values in 5 laboratories(1B, 2C, 4E, 5F and 6G) were as follows: optimal cut-off value＞manufactory recommeded cut-off value＞laboratory work cut-off value, thus use of manufactory-recommeded cut-off value abreadly has reached the high sensitivity requinements for laboratory screening; however, the optimal cut-off value in laboratories 1A, 3B and 7H, thas the appropriate gray zone should be used. In 6 laboratories setting up gray zone, the gensitivity in 3D, 7H laboratories only a little improved (1.60% and 2.70% raspectively) in Eamparison between laboratory work cut-off value and manufactorg-recommeded cut-off value; moreover, the sensitivity in other laboratories not is changed, but the specificity decreased (0.20%-0.50%). CONCLUSION: In addition to setting up the appropriate gray zone in laboratories 1A, 3D and 5H, the gray zone in other laboratories may be cancelled. Even in the same laboratory, the setting up the gray zone also should be scientifically assessed, the same scale cannot be blindly used, thus appropniate strategies should be established.

[Algorithm of digital demodulation and filtering in MRI spectrometers].

In the design of RF receiver of the digital MRI spectrometer console, a digital demodulation and filtering algorithm is presented in this thesis. The MR signals are firstly converted to digital signals by the A/D converter, and then quadrature-demodulated from high frequency carrier wave. The CIC filter, half-band filter and linear phase FIR filter are designed to process the cascaded filtering and decimation of the demodulated signals. This method achieves a satisfying processing speed and filtering effect, and also reduces the data size obviously. The experiment based on the permanent magnetism resonance imaging system proves its effectiveness and practicability.

[Finite element method-based optimal design of MRI permanent magnet].

This paper presents a simulation method to study and improve the technology of designing magnets. With the finite element method, it analyzes the magnetic field distribution of the magnet model constructed by CAD software. Based on the distribution characteristics of magnetic field, the redundancy parts of the magnet configuration are removed accurately. The experiment results show that this method can significantly lighten the magnet.

[Design of a digital spectrometer for the MRI system].

A spectrometer is one of the most important parts in a Magnetic Resonance Imaging (MRI) system. This paper describes the design of a digital MRI spectrometer. It is constructed on a PXI platform with several data acquisition boards and a high-resolution timing board. All functions of a MRI spectrometer are realized by the specially- designed software. The software architecture and its implementing details are discussed and experimental results are introduced.

[Research on designing MRI permanent magnet].

Based on the theory of magnet circuits, the paper introduces the process of designing MRI (Magnetic Resonance Imaging) permanent magnet. The measurement of magnet properties is improved by simulation technology. In order to increase the magnetic field homogeneity. We have designed a shim-loop and a trapeziform shim-board to optimize the magnetic field distribution. The results of both simulation analysis and experiments show that the innovative design improves magnetic field properties significantly and the magnet structure accords with the technology requirements.

[A rapid method of eddy current compensation in magnetic resonance imaging systems].

Imaging objects are spatially encoded by gradient magnetic fields in magnetic resonance imaging systems. The eddy current caused by rapid switches of gradient fields will result in artifacts in the images. A method of eddy current compensation based on pre-emphasis of gradient current is presented in this thesis. The compensation parameters are acquired rapidly utilizing Faraday's induction theorem and data fitting method. The experiments prove that the method is efficient for reduction of the debugging time and for the improvement of the image quality.

A novel digital magnetic resonance imaging spectrometer.

Spectrometer is the essential part of magnetic resonance imaging (MRI) system. It controls the transmitting and receiving of signals. Many commercial spectrometers are now available. However, they are usually costly and complex. In this paper, a new digital spectrometer based on PCI extensions for instrumentation (PXI) architecture is presented. Radio frequency (RF) pulse is generated with the method of digital synthesis and its frequency and phase are continuously tunable. MR signal acquired by receiver coils is processed by digital quadrature detection and filtered to get the k-space data, which avoid the spectral distortion due to amplitude and phase errors between two channels of traditional detection. Compared to the conventional design, the presented spectrometer is built with general PXI platform and boards. This design works in a digital manner with features of low cost, high performance and accuracy. The experiments demonstrate its efficiency.

[Correlation of thrombosis with increased platelet turnover in essential thrombocythemia].

This study was aimed to investigate the correlation of thrombosis with increased platelet turnover in essential thrombocythemia. According to presence or absence of thrombosis, 26 patients with ET were divided into two groups. Reticulated platelets (RP) were measured by flow cytometry and 26 healthy volunteers were selected as healthy controls. The ET patients with thrombosis were treated with hydroxyurea and interferon-alpha. The results demonstrated that the ET patients with thrombotic events had a significantly higher RP percentage (14.8% +/- 7.2%) than that in both asymptomatic ET patients (4.5% +/- 2.3%) and normal control (3.3% +/- 1.5%), (P < 0.05); the RP percentage in asymptomatic ET patients did not differ significantly from controls. ET patients with thrombosis also had a significantly higher absolute RP (ARP) count than those in ET patients without thrombosis [(176 +/- 37) x 10(9)/L vs (46 +/- 12) x 10(9)/L]. The ET patients with thrombosis were successfully treated with hydroxyurea plus INF-alpha, the RP percentage and ARP counts obviously reduced. In conclusion, when the ET patients had thrombotic events, those patients had a significantly higher RP percentage and ARP compared with patients without thrombosis and healthy controls. The ET patients with thrombosis were successfully treated with hydroxyurea plus INF-alpha.

[Cloning and expression of human interleukin-26 in Escherichia coli].

To clone human interleukin-26 (hIL-26) and express it in E. coli efficiently. Two pairs of primers were synthesized according to the hIL-26 gene reported on GenBank. The hIL-26 gene was cloned by nest PCR following the first round RT-PCR from human peripherial blood monocytes total RNA, and then the PCR product was cloned into pMD18-T vector. Colony PCR, restriction analysis and sequence analysis showed that the gene cloned was the same as the reported hIL-26. The recombinant was cut with BamHI and EcoR I to obtain the hIL-26 fragment, and then the fragment was inserted into pBV220 which was cut with the same enzymes. The recombinant expression vector was induced to express hIL-26 at 42 degrees C, SDS-PAGE analysis showed that the recombinant protein accounted for up to 20% of the whole protein of E. coli, and the protein was also confirmed by Western blotting. Purity of the protein was found to be above 90% after purified with molecular sieve. After renaturalized with glutathione buffer, the promoting effect of it on the production of IFN-y in PBMC was detected by RT-PCR. A recombinant bacterial strain for expressing hIL-26 with biological activity was constructed successfully.

A method for artifact correction due to demodulation phase errors in magnetic resonance imaging.

In the process that MR signal is quadrature demodulated, the initial phases of sinusoid and cosinusoid used as demodulation reference signal exist errors, which results in artifacts in the image. It is typically overcome through precise control of the initial phases with the help of the special hardware, but the errors are not reduced completely. In this work, a method based on reference scan is proposed. Reference scan without frequency encoding gradient and phase encoding gradient is executed before FSE sequence, and an echo train is acquired. The phase errors of sinusoid and cosinusoid that are used to demodulate each echo in the reference echo train are calculated. Then the k-space data of image is corrected by these errors and artifacts are removed. The experiments using 0.35T MRI system demonstrate the effectiveness of this method.