Optimization and impact of sensitivity mode on abbreviated scan protocols with population-based input function for parametric imaging of [18F]-FDG for a long axial FOV PET scanner.

BACKGROUND: The long axial field of view, combined with the high sensitivity of the Biograph Vision Quadra PET/CT scanner enables the precise deviation of an image derived input function (IDIF) required for parametric imaging. Traditionally, this requires an hour-long dynamic PET scan for [18F]-FDG, which can be significantly reduced by using a population-based input function (PBIF). In this study, we expand these examinations and include the scanner's ultra-high sensitivity (UHS) mode in comparison to the high sensitivity (HS) mode and evaluate the potential for further shortening of the scan time. METHODS: Patlak Ki and DV estimates were determined by the indirect and direct Patlak methods using dynamic [18F]-FDG data of 6 oncological patients with 26 lesions (0-65 min p.i.). Both sensitivity modes for different number/duration of PET data frames were compared, together with the potential of using abbreviated scan durations of 20, 15 and 10 min by using a PBIF. The differences in parametric images and tumour-to-background ratio (TBR) due to the shorter scans using the PBIF method and between the sensitivity modes were assessed. RESULTS: A difference of 3.4 ± 7.0% (Ki) and 1.2 ± 2.6% (DV) was found between both sensitivity modes using indirect Patlak and the full IDIF (0-65 min). For the abbreviated protocols and indirect Patlak, the UHS mode resulted in a lower bias and higher precision, e.g., 45-65 min p.i. 3.8 ± 4.4% (UHS) and 6.4 ± 8.9% (HS), allowing shorter scan protocols, e.g. 50-65 min p.i. 4.4 ± 11.2% (UHS) instead of 7.3 ± 20.0% (HS). The variation of Ki and DV estimates for both Patlak methods was comparable, e.g., UHS mode 3.8 ± 4.4% and 2.7 ± 3.4% (Ki) and 14.4 ± 2.7% and 18.1 ± 7.5% (DV) for indirect and direct Patlak, respectively. Only a minor impact of the number of Patlak frames was observed for both sensitivity modes and Patlak methods. The TBR obtained with direct Patlak and PBIF was not affected by the sensitivity mode, was higher than that derived from the SUV image (6.2 ± 3.1) and degraded from 20.2 ± 12.0 (20 min) to 10.6 ± 5.4 (15 min). Ki and DV estimate images showed good agreement (UHS mode, RC: 6.9 ± 2.3% (Ki), 0.1 ± 3.1% (DV), peak signal-to-noise ratio (PSNR): 64.5 ± 3.3 dB (Ki), 61.2 ± 10.6 dB (DV)) even for abbreviated scan protocols of 50-65 min p.i. CONCLUSIONS: Both sensitivity modes provide comparable results for the full 65 min dynamic scans and abbreviated scans using the direct Patlak reconstruction method, with good Ki and DV estimates for 15 min short scans. For the indirect Patlak approach the UHS mode improved the Ki estimates for the abbreviated scans.

Targeted Sequencing Improves DIPSS-Plus Prognostic Scoring in Myelofibrosis Patients Undergoing Allogeneic Transplantation.

Primary myelofibrosis (MF) and secondary MF developing after polycythemia vera or essential thrombocythemia are clonal disorders of hematopoiesis. Currently the sole therapy offering the potential of cure is hematopoietic cell transplantation (HCT). Several risk classification systems including clinical, hematologic, and mutational parameters have been proposed. We analyzed the mutational landscape in addition to the Dynamic International Prognostic Scoring System (DIPSS)-plus in 55 patients with MF to determine the combined impact on post-HCT outcome. Mutations, analyzed in 75 genes, were most common in JAK2, CALR, ASXL1, TET2, GATA2, EZH2, U2AF1, and ETV6. Patients with ≥3 mutations in addition to JAK2 or CALR mutations had a higher post-transplantation relapse rate and nonrelapse mortality than patients with fewer mutations, independent of DIPSS-plus risk. The presence of higher numbers of mutations identified patients at the greatest risk of relapse within the highest overall risk group as determined by DIPSS-plus. These findings are consistent with molecular risk classifications for patients who do not undergo HCT and support the proposed transplantation risk classification incorporating mutational information.

[Research progress on mechanisms of traditional Chinese medicine in prevention and treatment of postoperative peritoneal adhesion].

Peritoneal adhesion is one of the common complications after abdominal operation, which could seriously affect the quality of life in patients. Although the development of modern surgical technology and the improvement of doctors' operation level have reduced the incidence of peritoneal adhesion to a certain extent, due to the lack of special treatment drugs, the therapeutic effect still cannot meet the expectations and requirements of clinicians and patients. Traditional Chinese medicines(TCM) have unique advantages and remarkable curative effect in the treatment of peritoneal adhesion, and they can play an important role in regulating multiple pathological links. However, the relevant researches and product development of TCM against peritoneal adhesion have not attracted enough attention from industry scholars. As for the related work that has been carried out, most of the studies on the efficacy and mechanism are not thorough and systematic enough, seriously restricting the industrial development in this field. In this paper, the efficacy and mechanism were systematically described and summarized based on the review of papers in the recent years, so as to provide a reference for the thorough study of TCM in the prevention and treatment of peritoneal adhesions, and promote the deep development and industrialization process of related products.

Bulk Fermi Surfaces of the Dirac Type-II Semimetallic Candidates MAl_{3} (Where M=V, Nb, and Ta).

We report a de Haas-van Alphen (dHvA) effect study on the Dirac type-II semimetallic candidates MAl_{3} (where, M=V, Nb and Ta). The angular dependence of their Fermi surface (FS) cross-sectional areas reveals a remarkably good agreement with our first-principles calculations. Therefore, dHvA supports the existence of tilted Dirac cones with Dirac type-II nodes located at 100, 230 and 250 meV above the Fermi level ϵ_{F} for VAl_{3}, NbAl_{3} and TaAl_{3} respectively, in agreement with the prediction of broken Lorentz invariance in these compounds. However, for all three compounds we find that the cyclotron orbits on their FSs, including an orbit nearly enclosing the Dirac type-II node, yield trivial Berry phases. We explain this via an analysis of the Berry phase where the position of this orbit, relative to the Dirac node, is adjusted within the error implied by the small disagreement between our calculations and the experiments. We suggest that a very small amount of doping could displace ϵ_{F} to produce topologically nontrivial orbits encircling their Dirac node(s).

Metabolic response of LLC xenografted mice to oxythiamine, as measured by [¹H] NMR spectroscopy.

Oxythiamine (OT) has been proven to be a potential anticancer drug. With the help of NMR-based metabonomics, we studied the metabolic changes within tumor-bearing mice with different levels of OT administration using a C57BL/6 mouse Lewis lung carcinoma tumor transplantation model. We administered different concentrations of OT (75, 150, 300, and 600 mg∙kg(-1)∙day(-1)) to the mice orally for 2 weeks, recorded animal weights and tumor volumes, sacrificed the animals, and collected blood and tumor mass samples for nuclear magnetic resonance determination. Compared with the findings for the control (untreated) group, the tumor weights and volumes of the 150, 300, and 600 mg∙kg-1∙day-1 groups decreased with no difference among these OT groups. A large metabolite difference was observed in plasma metabolites between the blank and control groups, which indicated the success of the tumor-bearing model. The metabolites in tumor associated with thiamine-dependent enzymes (TDEs) underwent considerable change between the OT and control groups, exhibiting concentration dependence and enzyme specificity. The restriction of TDEs by OT may be a major mechanism underlying its anticancer effect. The role of OT as a potential anticancer drug and a dehydrogenase inhibitor should therefore be taken into consideration in future tumor research.

MicroRNA-19b targets Mfn1 to inhibit Mfn1-induced apoptosis in osteosarcoma cells.

Accumulative evidence has confirmed that, miR-17-92, a typical polycistronic mRNA cluster, was up-regulated in various solid tumors, and play an important role in the occurrence and development progress of tumors. In our study, we detected the six members of miR-17-92 cluster in osteosarcoma cell line, finding that the expression of miR-17 and miR-19b was up-regulated significantly. Further studies have found that Mfn1 was one of the target genes of miR-19b and the transcription and expression level of Mfn1 were down-regulated by miR-19b. MTS, flow cytometry, TUNEL-DAPI, Annexin V-FITC and transwell assay demonstrated that Mfn1 significantly blocked the cell cycle, promoted apoptosis and inhibited proliferation and invasion of osteosarcoma cells. Whereas, miR-19b targets 3'UTR sequences of Mfn1 genes inhibit the expression of Mfn1, thus inhibited Mfn1 triggered anti-cancer effect. Taken together, miR-19b functions by targeting Mfn1 reduce the protein expression level, thus provides a novel target to understand the molecular biology and genetics mechanisms of occurrence and development of osteosarcoma, contributing to the diagnosis and therapy of osteosarcoma.

Therapeutic effect of inhaled budesonide (Pulmicort® Turbuhaler) on the inflammatory response to one-lung ventilation.

This prospective, double-blind trial was designed to evaluate the effect of inhaled budesonide on lung function and the inflammatory response to one-lung ventilation. One hundred patients scheduled for lobectomy were allocated randomly to pre-operative nebulised budesonide or saline. Bronchoalveolar lavage fluid samples were collected from either the collapsed or the ventilated lung both before one-lung ventilation and 30 min after re-expansion of the lung. The concentrations of serum and bronchoalveolar lavage fluid cytokines were determined. Budesonide treatment, compared with saline, reduced both peak (mean (SD) 3.7 (0.4) vs 2.5 (0.2) kPa) and plateau (mean (SD) 3.1 (0.2) vs 2.2 (0.1) kPa, respectively, p < 0.001 for both) ventilatory pressures. Thirty minutes after re-expansion, lung compliance increased in the budesonide group compared with saline (57.5 (4.1) vs 40.1 (3.5) ml.cmH(2) O(-1), respectively p < 0.001). Budesonide also reduced the concentrations of tumour necrosis factor-α, interleukin-1ß, interleukin-6 and interleukin-8 in bronchoalveolar lavage fluid, but increased interleukin-10 30 min after re-expansion (p < 0.05 for all measures). Pre-operative nebulisation of budesonide may be effective in improving ventilatory mechanics and reducing the inflammatory response to one-lung ventilation during thoracic surgery.

Immediate total parenteral nutrition after radical cystectomy and urinary diversion.

INTRODUCTION: The purpose of this study is to determine if administration of total parenteral nutrition (TPN) immediately following radical cystectomy and urinary diversion provides significant recovery benefit when compared to patients who did not receive TPN. METHODS: Retrospective chart review was performed on patients who underwent open radical cystectomy and urinary diversion from February 2002 to June 2010. Patients were divided into 2 cohorts-those who received immediate postoperative TPN and those who did not. Preoperative demographics, length of hospital stay, time until tolerating a regular diet and early postoperative complications of the 2 groups were extracted and compared. RESULTS: One hundred seventy-four patients (104 receiving TPN, 70 without TPN) were available for analysis. No significant difference in preoperative characteristics, length of hospital stay, estimated blood loss, or time until tolerating a general diet between the 2 groups was noted. With regard to complications, the incidence of bacteremia was significantly higher in the TPN vs non-TPN cohort (9% vs 1%, P < 0.05). CONCLUSION: Immediate administration of TPN following radical cystectomy and urinary diversion does not provide a significant postoperative benefit and may lead to an increased risk of bacteremia.

Butyrate induces reactive oxygen species production and affects cell cycle progression in human gingival fibroblasts.

BACKGROUND AND OBJECTIVE: Short-chain fatty acids, such as butyric acid and propionic acid, are metabolic by-products generated by periodontal microflora such as Porphyromonas gingivalis, and contribute to the pathogenesis of periodontitis. However, the effects of butyrate on the biological activities of gingival fibroblasts (GFs) are not well elucidated. MATERIAL AND METHODS: Human GFs were exposed to various concentrations of butyrate (0.5-16 mm) for 24 h. Viable cells that excluded trypan blue were counted. Cell cycle distribution of GFs was analyzed by propidium iodide-staining flow cytometry. Cellular reactive oxygen species (ROS) production was measured by flow cytometry using 2',7'-dichlorofluorescein (DCF). Total RNA and protein lysates were isolated and subjected to RT-PCR using specific primers or to western blotting using specific antibodies, respectively. RESULTS: Butyrate inhibited the growth of GFs, as indicated by a decrease in the number of viable cells. This event was associated with an induction of G0/G1 and G2/M cell cycle arrest by butyrate (4-16 mm) in GFs. However, no marked apoptosis of GFs was noted in this experimental condition. Butyrate (> 2 mm) inhibited the expression of cdc2, cdc25C and cyclinB1 mRNAs and reduced the levels of Cdc2, Cdc25C and cyclinB1 proteins in GFs, as determined using RT-PCR and western blotting, respectively. This toxic effect of butyrate was associated with the production of ROS. CONCLUSION: These results suggest that butyrate generated by periodontal pathogens may be involved in the pathogenesis of periodontal diseases via the induction of ROS production and the impairment of cell growth, cell cycle progression and expression of cell cycle-related genes in GFs. These events are important in the initiation and prolongation of inflammatory processes in periodontal diseases.

Acupuncture combined with exercise training at different time points on nerve repair of cerebral ischemia-reperfusion injury in rats and its effects on the expressions of Nestin, bFGF and EGF.

OBJECTIVE: The aim of the study was to observe the neuroreparative effect of electroacupuncture in rats with cerebral ischemia-reperfusion injury, and to explore the difference in the therapeutic effect of acupuncture on different acupoint groups after cerebral ischemia-reperfusion. MATERIALS AND METHODS: Experimental rats were randomly divided into: sham operation group, model group, electroacupuncture group, rehabilitation group, and Diankang group (electroacupuncture + rehabilitation training). There were 24 rats in each group, and the focal cerebral ischemia-reperfusion model was established by Zea-Longa suture method. After modeling, it took 4 hours to electroacupuncture at Baihui and Dazhui points, which was used to observe the changes of nerve function in rats with signs of keel nerve function defect. Protein expression was detected by immunohistochemistry. RESULTS: Compared with the model group, the EA 3d, 7d, 10d groups and the rehabilitation group had no significant difference in promoting the expression of Nestin (p>0.05). There was a significant difference (p<0.01). After cerebral ischemia-reperfusion injury, the expression of bFGF and EGF on the ischemic side was stronger. The peak of bFGF expression appeared earlier, and the peak of EGF expression appeared later. The expression of bFGF and EGF in cerebral ischemic cortex at different time points of ischemia in electroacupuncture group, rehabilitation group and Diankang group was increased, and the response was enhanced. The effect of Diankang group on the upregulation of bFGF and EGF was more significant (p<0.01, p<0.05). CONCLUSIONS: Under the influence of different effects, Diankang is superior to simple treatment in improving ischemic neurological dysfunction. This may be related to the fact that Diankang can promote the proliferation of neural stem cells and the expression of neurotrophic factors on the ischemic side of the rat brain.

Comparison of laparoscopic common bile duct exploration and endoscopic retrograde cholangiopancreatography combined with laparoscopic cholecystectomy for patients with gallbladder and common bile duct stones a meta-analysis of randomized controlled trials.

OBJECTIVE: This study aimed to compare the efficacy and safety of laparoscopic common bile duct exploration (LCBDE) and endoscopic retrograde cholangiopancreatography (ERCP) combined with laparoscopic cholecystectomy (LC) to determine which one provides a better outcome for patients with gallbladder and common bile duct stones. MATERIALS AND METHODS: An electronic literature search was undertaken using Embase, Medline, PubMed, and Cochrane Library databases up to April 2022. For quality assessment of included studies, randomized controlled trials (RCTs) were assessed by utilizing the Jadad scale. The primary outcome includes surgical success rate, retained stone rate, stone clearance rate, major morbidity, and mortality. The second outcome includes conversion to open surgery rate, postoperative pancreatitis, bile leakage, cholangitis, hemorrhage, pneumonia, and surgical-site infection. RESULTS: 14 randomized controlled trials with 2,181 patients were included. No significant difference was seen between the two groups in terms of surgical success, stone clearance, retained stones, operation time, and total morbidity. LC-LCBDE had higher rate of bile leakage [relative risk (RR): 4.52; 95% confidence interval (CI): 2.19-9.31] and lower rate of postoperative pancreatitis (RR: 0.25; 95% CI: 0.13-0.46), cholangitis (RR: 0.17; 95% CI: 0.05-0.67), and hemorrhage (RR: 0.18; 95% CI: 0.07-0.42). CONCLUSIONS: Both LC+LCBDE and LC+ERCP are safe, effective, and minimal-invasive treatments for concomitant gallbladder and CBD stones. LC-LCBDE was associated with comparable effects compared with LC+ERCP in terms of surgical success rate, stone clearance rate, retained stones rate, operation time, and total morbidity. At the same time, LC-LCBDE had a higher rate of bile leakage and a lower rate of postoperative pancreatitis, cholangitis, and hemorrhage.

Red cell distribution in critically ill patients with chronic obstructive pulmonary disease.

BACKGROUND: Red blood cell distribution width (RDW) is associated with increased mortality risk in patients with chronic obstructive pulmonary disease (COPD). However, limited data are available for critically ill patients with COPD. METHODS: Data from the Medical Information Mart for Intensive Care III V1.4 database were analyzed in this retrospective cohort research. The International Classification of Diseases codes were used to identify critically ill patients with COPD. The first value of RDW was extracted within the first 24 h after intensive care unit admission. The endpoint was 28-day all-cause mortality. Multivariable logistic regression analysis was performed to examine the relationship between RDW and 28-day mortality. Age, sex, ethnicity, anemia status, comorbidities, clinical therapy, and disease severity score were considered for subgroup analysis. RESULTS: A total of 2,344 patients were included with mean (standard deviation) age of 72.3 (11.3) years, in which 1,739 (53.6%) patients were men. The increase in RDW was correlated with an increased risk of 28-day mortality in the multivariate logistic regression model (odds ratio [OR] 1.15; 95% confidence interval [CI] 1.09-1.21). In comparison with the low-RDW group, the middle and high-RDW groups tended to have higher risks of 28-day all-cause mortality (OR [95% CI] 1.03 [0.78-1.34]; OR [95% CI] 1.70 [1.29-2.22]; P trend < 0.0001). Subgroup analyses show no evidence of effect modifications on the correlation of RDW and 28-day all-cause mortality. CONCLUSION: An increase in RDW was associated with an increased risk of 28-day all-cause mortality in critically ill patients with COPD. Further studies are required to investigate this association.

[Effects and mechanism of pressure treatment on hemodynamic changes in patients with hypertrophic scar secondary to extensive burns].

Objective: To investigate the hemodynamic changes of the main arteries and veins of the extremities and the heart in patients with hypertrophic scar secondary to extensive burns after pressure treatment, and to analyze the relevant mechanisms. Methods: A retrospective before-after self-control study was conducted. From January 2017 to February 2022, 37 patients with hypertrophic scar secondary to extensive burns who met the inclusion criteria were hospitalized in the Burn Rehabilitation Department of Guangdong Industrial Injury Rehabilitation Hospital, including 25 males and 12 females, aged 23-52 years. The patients were admitted to the hospital within 12 weeks after wound healing, and within one week after admission, rehabilitation therapists, occupational therapists, and tailors custom-made pressure products such as full-body pressure garment, pressure pants, vests, split finger gloves, split finger socks, hoods, and plastic collars, with the pressure at each part maintained at 2.67-4.00 kPa when wearing. Before the first treatment with pressure products (hereinafter referred to as before pressure treatment) and at 1 h of the first treatment with pressure products (hereinafter referred to as 1 h of pressure treatment), color Doppler ultrasonography was performed to check the pulse rate of the axillary artery, the lumen diameter, peak systolic velocity (PSV), and resistance index of the axillary artery and femoral artery on the left side, the lumen diameter, cross-sectional area, and average blood flow velocity of the axillary vein and femoral vein, and the mitral valve E peak, mitral valve A peak, tricuspid valve E peak, aortic valve PSV, and pulmonary valve PSV of the heart; an optical chromatographic skin detector was used to detect the red color, red pigment, and surface brightness of the scar on the back of the hand to reflect the filling and distribution of the scar microvessels. Data were statistically analyzed with paired sample t test. Results: Compared with those before pressure treatment, the PSV of the axillary artery of patients was significantly slowed down at 1 h of pressure treatment (t=55.42, P<0.01); the average blood flow velocity of the axillary vein was significantly accelerated (t=-60.50, P<0.01); the pulse rate, lumen diameter, and resistance index of the axillary artery, as well as the lumen diameter and cross-sectional area of the axillary vein did not change obviously (P>0.05); the average blood flow velocity of the femoral vein was significantly accelerated (t=-80.52, P<0.01); the lumen diameter, PSV, and resistance index of the femoral artery, as well as the lumen diameter and cross-sectional area of the femoral vein had no significant change (P>0.05); the mitral valve E peak and mitral valve A peak of the heart decreased significantly (with t values of 10.71 and 21.96, respectively, P<0.01); the tricuspid valve E peak of the heart increased significantly (t=7.57, P<0.01); the PSV of the aortic valve and pulmonary valve of the heart did not change obviously (P>0.05). At 1 h of pressure treatment, the red color and red pigment values of the scar on the back of the hand of patients were 15.3±1.1 and 16.8±1.2, respectively, which were significantly lower than 24.5±1.3 and 23.8±1.2 before pressure treatment (with t values of 8.32 and 8.04, respectively, P<0.01). The brightness value of the scar surface on the back of the hand of patients at 1 h of pressure treatment was similar to that before pressure treatment (P>0.05). Conclusions: After pressure treatment for the hypertrophic scar in patients secondary to extensive burn, the average blood flow velocity of the axillary vein and femoral vein in patients are obviously accelerated, the PSV of the axillary artery is significantly slowed down, the peak values of mitral valve E and mitral valve A of the heart are significantly decreased, and the tricuspid valve E peak is significantly increased. These hemodynamic changes may be related to the reduction of microvascular blood flow in the local area of scar after systemic pressure treatment.

Preparation of monodispersed chitosan microspheres and in situ encapsulation of BSA in a co-axial microfluidic device.

This work describes a novel microfluidic method to prepare monodispersed chitosan microspheres by using the solvent extraction method. Our strategy is that a chitosan/acetic acid aqueous solution is emulsified in an organic phase containing the extractant by using the co-flowing shear method in a co-axial microfluidic device. The formed droplets are in situ solidified within a synthesizing channel by the extraction of acetic acid from the chitosan aqueous droplets to the organic solution. Based on this approach, the size of chitosan microspheres can be successfully controlled from 100 mum to 700 mum in diameter with a variation of less than 4%. Furthermore, high loading efficiency (>95%) of Bovine serum albumin (BSA) can be in situ encapsulated. The present method has the advantages of actively controlling the droplet diameter, narrow size distribution, good sphericity, and having a simple and low cost process, with a high throughput. This approach for the preparation of chitosan microspheres will provide many potential applications for pharmaceutical area.

Optical control of phase transformation in Fe-doped TiO2 nanoparticles.

A series of anatase phase Fe-doped TiO2 nanoparticles are prepared by a modified sol-gel method. Spontaneous Raman spectroscopy is utilized to characterize the crystal structures of these nanoparticles and investigate their structural transformation under the exposure of a 532 nm green laser. The anatase phase of TiO2 can be effectively converted into the rutile phase with the assistance of Fe doping. It is found that the critical laser intensity for phase transformation decreases with increasing the Fe content. We ascribe this tendency to the enhanced optical absorption and the photo-induced thermal heating effect, which can be associated with the defect structure within the bandgap of Fe- TiO2 nanoparticles. Our study demonstrates an all-optical approach to pump and probe the phase transformation of metal-doped TiO2 nanoparticles.

Lack of association between HLA-A, -B and -DRB1 alleles and the development of SARS: a cohort of 95 SARS-recovered individuals in a population of Guangdong, southern China.

Severe acute respiratory syndrome (SARS), caused by infection with a novel coronavirus (SARS-CoV), was the first major novel infectious disease at the beginning of the 21st century, with China especially affected. SARS was characterized by high infectivity, morbidity and mortality, and the confined pattern of the disease spreading among the countries of South-East and East Asia suggested the existence of susceptible factor(s) in these populations. Studies in the populations of Hong Kong and Taiwan showed an association of human leucocyte antigen (HLA) polymorphisms with the development and/or severity of SARS, respectively. The aim of the present study was to define the genotypic patterns of HLA-A, -B and -DRB1 loci in SARS patients and a co-resident population of Guangdong province, southern China, where the first SARS case was reported. The samples comprised 95 cases of recovered SARS patients and 403 unrelated healthy controls. HLA -A, -B and -DRB1 alleles were genotyped using polymerase chain reaction with sequence-specific primers. The severity of the disease was assessed according to the history of lung infiltration, usage of assisted ventilation and occurrence of lymphocytopenia. Although the allelic frequencies of A23, A34, B60, DRB1*12 in the SARS group were slightly higher, and A33, -B58 and -B61 were lower than in the controls, no statistical significance was found when the Pc value was considered. Similarly, no association of HLA alleles with the severity of the disease was detected. Thus, variations in the major histocompatibility complex are unlikely to have contributed significantly to either the susceptibility or the severity of SARS in the population of Guangdong.

The effect of midazolam on cerebral endothelial (P-selectin and ICAM-1) adhesion molecule expression during hypoxia-reperfusion injury in vitro.

BACKGROUND AND OBJECTIVE: Hypoxia-reperfusion injury is an important determinant of secondary brain injury. In the acute phase of cerebral reperfusion, pro-inflammatory events enhance expression of cerebral endothelial (intercellular adhesion molecule-1 and P-selectin) adhesion molecules, which play an important role in brain hypoxia-reperfusion injury. Midazolam is the most commonly used sedative in patients with brain injury. The objective of this investigation was to examine the effect of midazolam on the expression of cerebral endothelial intercellular adhesion molecule-1 and P-selectin during hypoxia-reperfusion injury in vitro. METHODS: The up-regulation of mouse cerebral endothelial cells intercellular adhesion molecule-1 and P-selectin was assessed following hypoxia-reoxygenation (hypoxia-reperfusion). Cells were pre-treated with three different concentrations of midazolam (0, 5 and 50 microg mL(-1)) prior to hypoxia. Flow cytometry was used to estimate adhesion molecule expression mean channel fluorescence. Data are presented as mean +/- SD. RESULTS: Mouse cerebral endothelial cell intercellular adhesion molecule-1 and P-selectin expression was greater after exposure to hypoxia-reoxygenation compared to normoxia (mean channel fluorescence) 241 +/- 12 vs. 140 +/- 7 and 120 +/- 14 vs. 46 +/- 7, respectively, P < 0.05. Intercellular adhesion molecule-1 and P-selectin expression was decreased by midazolam (5 microg mL(-1)) pre-incubation compared to control, mean channel fluorescence 184 +/- 10 vs. 241 +/- 12 and 51 +/- 7 vs. 120 +/- 14, respectively, P < 0.05. Midazolam at 50 microg mL(-1) had the same effect as 5 microg mL(-1). CONCLUSION: Pre-treatment with midazolam diminishes increased expression of cerebral endothelial intercellular adhesion molecule-1 and P-selectin expression following hypoxia-reoxygenation.

Effects of EDTA on the hydration mechanism of mineral trioxide aggregate.

Ethylenediaminetetraacetic acid (EDTA) is commonly used during the preparation of obstructed root canals that face a high risk of root perforation. Such perforations may be repaired with mineral trioxide aggregate (MTA). Due to EDTA's ability to chelate calcium ions, we hypothesized that EDTA may disrupt the hydration of MTA. Using scanning electron microscopy and energy-dispersive x-ray spectroscopy, we found that MTA specimens stored in an EDTA solution had no crystalline structure and a Ca/Si molar ratio considerably lower than those obtained for specimens stored in distilled water and normal saline. Poor cell adhesion in EDTA-treated MTA was also noted. X-ray diffraction indicated that the peak corresponding to portlandite, which is normally present in hydrated MTA, was not shown in the EDTA group. The microhardness of EDTA-treated specimens was also significantly reduced (p < 0.0001). These findings suggest that EDTA interferes with the hydration of MTA, resulting in decreased hardness and poor biocompatibility.

Decontamination of vegetables sprayed with organophosphate pesticides by organophosphorus hydrolase and carboxylesterase (B1).

A genetically engineered Escherichia coli cell expressing both organophosphorus hydrolase (OPH) and carboxyl esterase (CaE) B1 intracellularly was constructed and cultivated. The harvested wet cells were vacuum dried, and the storage stability of the dried cell powder was determined in terms of OPH activity. Over a period of 5 mo, the dried cells showed no significant decrease in the activities of the detoxifying enzymes. The crude enzymes in 50 mM citrate-phosphate buffer (pH 8.0) were able to degrade approx 97% of the organophosphate pesticides sprayed on cabbage. The detoxification efficiency was superior to that of the treatments of water, detergent, and a commercially available enzyme product. Additionally, the products of pesticide hydrolysis generated by treatment with the enzyme extract were determined to be virtually nontoxic.