[Clinical outcomes of COVID-19 cases and influencing factors in Guangdong province]

Objective: To analyze the clinical courses and outcomes of COVID-19 cases and the influencing factors in Guangdong province and provide basis for the formulation or adjustment of medical care and epidemic control strategy for COVID-19. Methods: We collected demographic data, medical histories, clinical courses and outcomes of 1 350 COVID-19 patients reported in Guangdong as of 4 March 2020 via epidemiological investigation and process tracking. Disease severity and clinical course characteristics of the patients and influencing factors of severe illness were analyzed in our study. Results: Among 1 350 cases of COVID-19 cases in Guangdong, 72 (5.3%) and 1 049 (77.7%) were mild and ordinary cases, 164 (12.1%) were severe cases, 58 (4.3%) were critical cases and 7 (0.5%) were fatal. The median duration of illness were 23 days (P(25), P(75): 18, 31 days) and the median length of hospitalization were 20 days (P(25), P(75): 15,27 days). For severe cases, the median time of showing severe manifestations was on the 12(th) day after onset (P(25), P(75): 9(th) to 15(th) days), and the median time of severe manifestation lasted for 8 days (P(25), P(75): 4, 14 days). Among 1 066 discharged/fetal cases, 36.4% (36/99) and 1.0% (1/99) of the mild cases developed to ordinary cases and severe cases respectively after admission; and 5.2% (50/968) and 0.6% (6/968) of the ordinary cases developed to severe cases, and critical cases respectively after admission. In severe cases, 11.4% developed to critical cases (10/88). The influencing factors for severe illness or worse included male (aHR=1.87, 95%CI: 1.43-2.46), older age (aHR=1.67, 95%CI: 1.51-1.85), seeking medical care on day 2-3 after onset (aHR=1.73, 95%CI: 1.20-2.50) pre-existing diabetes (aHR=1.75, 95%CI: 1.12-2.73) and hypertension (aHR=1.49, 95%CI: 1.06-2.09). Conclusions: The course of illness and length of hospitalization of COVID-19 cases were generally long and associated with severity of disease clinical outcomes. The severe cases were mainly occurred in populations at high risk. In the epidemic period, classified management of COVID-19 cases should be promoted according to needs for control and prevention of isolation and treatment for the purpose of rational allocation of medical resources.

Laser vibrational excitation of radicals to prevent crystallinity degradation caused by boron doping in diamond

Pursuing high-level doping without deteriorating crystallinity is prohibitively difficult but scientifically crucial to unleashing the hidden power of materials. This study demonstrates an effective route for maintaining lattice integrity during the combustion chemical vapor deposition of highly conductive boron-doped diamonds (BDDs) through laser vibrational excitation of a growth-critical radical, boron dihydride (BH₂). The improved diamond crystallinity is attributed to a laser-enabled, thermal nonequilibrium suppression of the relative abundance of boron hydrides (BH), whose excessive presence induces boron segregation and disturbs the crystallization. The BDDs show a boron concentration of 4.3 × 10²¹ cm^-3, a film resistivity of 28.1 milliohm·cm, and hole mobility of 55.6 cm² V^-1 s^-1, outperforming a commercial BDD. The highly conductive and crystalline BDDs exhibit enhanced efficiency in sensing glucose, confirming the advantages of laser excitation in producing high-performance BDD sensors. Regaining crystallinity with laser excitation in doping process could remove the long-standing bottlenecks in semiconductor industry.

Urinary microRNAs miR-15b and miR-30a as novel noninvasive biomarkers for gentamicin-induced acute kidney injury

MicroRNAs serve as potential biomarkers in various pathological models, and are stable and detectable in biofluids. We investigated the urinary microRNA expression profile in a gentamicin-induced acute kidney injury canine model using RNA sequencing. A total of 234 differentially expressed microRNAs were screened after 12 consecutive days of gentamicin administration (P < 0.05). Six candidate microRNAs (miR-15b, -15b-3p, -16, -30a, -30a-3p, and -30c-2-3p) were selected according to a set criterion, and validated by real-time quantitative PCR. The diagnostic values of these six candidate microRNAs were better than the traditional serum biomarkers (all P < 0.05). Further, using receiver operating characteristic curve analysis, we found that miR-15b and -15b-3p were superior to urinary kidney injury molecule-1 (both P < 0.05). Moreover, miR-15b and -30a levels in the urine samples significantly correlated with their respective levels in the kidney tissue samples (r=0.512 and 0.505, respectively, both P < 0.05). Our data concluded that miR-15b and -30a may be promising biomarkers for renal toxicity.

[Analysis on the cluster epidemic of coronavirus disease 2019 in Guangdong Province]

Objective: Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province. Methods: The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared. Results: A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M (P₂₅, P₇₅) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant (P=0.003). Conclusion: COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

[Overexpression of protein phosphatase 2 regulatory subunit B''α gene effect on proliferation and invasion of hepatoma cells]

Objective: To study the overexpression of protein phosphatase 2 regulatory subunit B''α gene effects on the proliferation and invasion of hepatoma cells. Methods: Immunohistochemistry method was used to analyze the expression of PPP2R3A in cancerous and paracancerous tissues. Hepatocellular carcinoma cell lines (Huh-7 and HepG2) with stably overexpressing PPP2R3A were constructed by lentiviral vector. Biological behavioral transition in hepatocellular carcinoma cell proliferation, cell cycle, apoptosis, invasion and metastasis were detected by cell counting kit-8 assay (CCK-8), flow cytometry, and transwell assay. A subcutaneous nude tumor mice model was constructed to validate the growth of hepatoma cells. Two independent sample t-tests were used to compare the groups. Results: The expression of PPP2R3A gene in human hepatocarcinoma tissues was higher than paracancerous tissues. The absorbance (A value) of hepatoma cells was increased (P < 0.05) after overexpression of PPP2R3A gene. The transition from G1-to-S phase was significantly increased i.e., the G1 phase of the cell cycle was reduced (Huh-7: t = 3.04, P = 0.0384; HepG2: t = 4.06, P = 0.0153), while the S phase was increased (Huh-7: t = 3.47, P = 0.0255; HepG2: t = 4.46, P = 0.0112). Early apoptotic rate was decreased (Huh-7: t = 7.34, P = 0.0018; HepG2: t = 4.06, P = 0.0153). The number of Huh-7 cells migrating to the lower chamber was increased (t = 3.18, P = 0.0334), and after the use of matrigel the number of cells reaching to the lower chamber was also increased (t = 2.84, P = 0.0464). The results of animal experiments showed that the subcutaneous tumor growth (t = 4.31, P = 0.0035) was significantly overexpressed in nude mice group. The results of Western blot showed that the expression of PARP and P53 protein in the spliced ​​forms decreased, while the accumulation of β-catenin protein in the liver cancer cells was increased. Conclusion: Overexpressed PPP2R3A gene may promote proliferation, migration and invasion ability, inhibit apoptosis, induce G1/S phase transition, and participate in the biological behavior of hepatoma cells.

[Correlation between CTL and Th1 cell proportion in peripheral blood of liver transplantation recipients and the success of hepatitis B vaccination]

Objective: To investigate the correlation between the proportion of CTL and Th1 cells in peripheral blood of liver transplant recipients and the success of hepatitis B vaccination. Methods: The subjects of this study were liver transplantation recipients with chronic HBV-related liver diseases in Organ transplantation institute of the third medical center of PLA general hospital. Subjects were randomly divided into two groups for prospective study. In the rapid group, one dose of 40 μg hepatitis B vaccine was administered at 0, 1, 2and 3 months, and one dose of 20 μg hepatitis B vaccine was administered at 4, 5 and 6 months. In the rapid-enhanced group, one dose of 40 μg hepatitis B vaccine was administered at 0, 1, 2 and 3 months, and one dose of 60 μg hepatitis B vaccine was administered at 4, 5 and 6months. Compare and analyze the success rate of inoculation, the titer of hepatitis B surface antibody (anti-HBs), the proportion of CTL cells in CD8(+)T cells and Th1 cells in CD4(+)T cells. Correlation analysis was performed for CTL and Th1 cells and anti-HBs, Observe the safety of vaccination. Results: The inoculation success rate, anti-HBs growth rate, CTL cell percentage increase and Th1 cell percentage increase in the rapid enhancement group were all higher than those in the rapid enhancement group, and the differences were statistically significant, they were 38.3% (23/60) vs 21.7% (13/60) (P=0.046), 91.3(72.5,124.2) vs 22.1(12.4, 31.6) (P=0.001), 1.4(0.8,1.9) vs 0.4(0.2,1.4) (P=0.001) and 7.4±2.6 vs 5.6±3.7 (P=0.001) respectively. The percentage increase of CTL cells and Th1 cells in the successful group was greater than that in the non-successful group, and the difference was statistically significant. They were 1.9(1.4,2.5) vs 0.1(0.0,1.1) (P=0.024) and 9.6±3.1 vs 2.4±2.0 (P<0.001). There was no significant correlation between anti-HBs increase (105.5±37.1) and CTL increase 1(0,3) (P=0.099), while there was significant positive correlation with Th1 increase 7(2,11) (P<0.001). No rejection reaction occurred during the study period, and there was no special abnormal change in the safety index. Conclusion: Reasonable increase of vaccine dose can up-regulate Th1 cell expression and promote the generation of anti-HBs.

[Biomechanical study of different kinds of internal fixation for the typeⅠ Hangman fracture, type Ⅱ odontoid fracture and the C(2/3) disc injury: a finite-element analysis]

Objectives: To analyze the biomechanical stability of four kinds of internal fixation for the type Ⅰ Hangman fracture, type Ⅱ odontoid fracture and the C(2/3) disc injury by finite element (FE) analysis. Methods: Thin-section spiral computed tomography (0.5 mm) was performed on C(1) to C(3) region of cervical vertebra in healthy male volunteers.A three-dimensional hexahedral FE model of upper cervical spine was established by software (Mimics, GEOMAGICS, Pro/E and Ansys). Then the weakening of the strength of grid was performed to simulate the FE model of the type Ⅰ Hangman fracture, type Ⅱ odontoid fracture and the C(2/3) disc injury (FE/Fracture), the four internal fixation models: anterior cervical plate+ odontoid screw+ cage (FE/ACP+ OS+ cage), affixing rods from pedicle screws in C(2) to lateral mass screws in C(3)+ odontoid screw + cage (FE/C(2)PS+ C(3)LMS+ OS+ cage), affixing rods from pedicle screws in C(1) to pedicle screws in C(2) and lateral mass screws in C(3) (FE/C(1)PS+ C(2)PS+ C(3)LMS), anterior odontoid screw plate fixation system (FE/AOSP) were simulated on the FE/Fracture model.Flexion, extension, lateral bending and axial rotation were imposed on the FE/Intact, FE/Fracture and the four fixation models respectively. Results: The intact model of upper cervical spine (C(1)-C(3)) was established successfully, consisting of 259 641 nodes and 403 674 units.There was no significant difference among the FE/ACP+ OS+ cage, the FE/ C(2)PS+ C(3)LMS+ OS+ cage and the FE/AOSP of ROMC(1/2).During flexion, extension, left axial rotation and right axial rotation of ROMC(2)-C(3), the FE/AOSP decreased 70.7%, 74.4%, 38.9%, 41.1% respectively compared with the FE/C(1)PS+ C(2)PS+ C(3)LMS.The ROMC(2)-C(3) during flexion, extension, left lateral bending, right lateral bending, left axial rotation and right axial rotation in the FE/AOSP decreased for 82.2%, 82.8%, 73.2%, 64.8%, 72.2%, 81.5% respectively when compared with those in FE/ACP+ OS+ cage.The ROMC(2)-C(3) during flexion, extension, left lateral bending, right lateral bending, left axial rotation and right axial rotation in the FE/AOSP decreased 88.2%, 81.2%, 47.6%, 41.2%, 38.9%, 39.0% respectively when compared with those in FE/C(2)PS+ C(3)LMS+ OS+ cage.The stress concentrated on the connection between plate and screw in the FE/ACP+ OS+ cage, the FE/C(2)PS+ C(3)LMS+ OS+ cage and the FE/C(1)PS+ C(2)PS+ C(3)LMS, while it distributed evenly in the FE/AOSP. Conclusion: Anterior odontoid screw plate fixation system can be used to treat the type Ⅰ Hangman fracture, type Ⅱ odontoid fracture, and the C(2/3) disc injury and can reserve the function of atlanto-axial joint.

[Overview of traditional Chinese medicine of "Xiang Qi" theory of origins]

The theory of "Xiang Qi" (inspecting Qi or inspecting pneumata) is an important method of TCM inspection.It has important value in clinical diagnosis.The theoretical framework of "Xiang Qi" has been formed from the Huangdi Neijing (The Yellow Emperor's Classic of Medicine)《》. The many ideas were improved and developed in many dynasties such as Sui, Tang, Song, Jin and Yuan. Especially the theory of "Xiang Qi" has been inherited and applied in Ming and Qing dynasties, the theory of "Xiang Qi" became an important diagnostic method for the clinical practice.Especially Wang Hong()'s Wang Zhen Zun Jing(Inspection following the classics)《》 in Qing Dynasty was published.It perfected and developed the ten kinds of methods of "Xiang Qi" from three aspects. And it contained four diagnostic methods by examining Qi to determine the disease.It has promoted the value and the clinical application of "Xiang Qi" theory, and has contributed to the development of "Xiang Qi" theory.

Enhancement or inhibition of PLCγ2 expression in rat hepatocytes by recombinant adenoviral vectors that contain full-length gene or siRNA

We investigated the effects of recombinant adenovirus vectors that overexpress or silence PLCγ2 on the expression of this gene during hepatocyte proliferation. Hepatocytes were isolated, identified by immunofluorescent cytochemical staining and infected by previously constructed Ad-PLCγ2 and Ad-PLCγ2 siRNA1, siRNA2 and siRNA3. Green fluorescent protein (GFP) expression was observed by fluorescence microscopy. Infection percentage was calculated by flow cytometry. mRNA and protein levels of PLCγ2 were detected by quantitative reverse transcription-PCR (qRT-PCR) and western blotting, respectively. The viability of the infected hepatocytes was measured by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. We found that nearly 97% of cells were positive for the hepatocyte marker, CK18. After infection of Ad-PLCγ2 and Ad-PLCγ2 siRNA, more than 99% of hepatocytes expressed GFP significantly, and mRNA and protein expression of PLCγ2 was up-regulated significantly in Ad-PLCγ2 infected hepatocytes, but down-regulated in Ad-PLCγ2 siRNA2 infected cells. The cell proliferation rate decreased in PLCγ2-overexpressing cells, while the rate increased in PLCγ2-silencing cells. We verified that recombinant Ad-PLCγ2 and Ad-PLCγ2 siRNA2 were constructed successfully. These two recombinant vectors promoted or decreased the expression of PLCγ2 in rat hepatocytes and affected the cell proliferation rate, which provides a useful tool for further investigation of the role of PLCγ2 in hepatocyte apoptosis.

Quality assessment of groundwater from the south-eastern Arabian Peninsula

Assessment of groundwater quality plays a significant role in the utilization of the scarce water resources globally and especially in arid regions. The increasing abstraction together with man-made contamination and seawater intrusion have strongly affected groundwater quality in the Arabia Peninsula, exemplified by the investigation given here from the United Arab Emirates, where the groundwater is seldom reviewed and assessed. In the aim of assessing current groundwater quality, we here present a comparison of chemical data linked to aquifers types. The results reveal that most of the investigated groundwater is not suitable for drinking, household, and agricultural purposes following the WHO permissible limits. Aquifer composition and climate have vital control on the water quality, with the carbonate aquifers contain the least potable water compared to the ophiolites and Quaternary clastics. Seawater intrusion along coastal regions has deteriorated the water quality and the phenomenon may become more intensive with future warming climate and rising sea level.

Genome-wide analysis of salinity-stress induced DNA methylation alterations in cotton (Gossypium hirsutum L.) using the Me-DIP sequencing technology

Cytosine DNA methylation is a significant form of DNA modification closely associated with gene expression in eukaryotes, fungi, animals, and plants. Although the reference genomes of cotton (Gossypium hirsutum L.) have been publically available, the salinity-stress-induced DNA methylome alterations in cotton are not well understood. Here, we constructed a map of genome-wide DNA methylation characteristics of cotton leaves under salt stress using the methylated DNA immunoprecipitation sequencing method. The results showed that the methylation reads on chromosome 9 were most comparable with those on the other chromosomes, but the greatest changes occurred on chromosome 8 under salt stress. The DNA methylation pattern analysis indicated that a relatively higher methylation density was found in the upstream2k and downstream2k elements of the CDS region and CG-islands. Almost 94% of the reads belonged to LTR-gspsy and LTR-copia, and the number of methylation reads in LTR-gypsy was four times greater than that in LTR-copia in both control and stressed samples. The analysis of differentially methylated regions (DMRs) showed that the gene elements upstream2k, intron, and downstream2k were hypomethylated, but the CDS regions were hypermethylated. The GO (Gene Ontology) analysis suggested that the methylated genes were most enriched in cellular processes, metabolic processes, cell parts and catalytic activities, which might be closely correlated with response to NaCl stress. In this study, we completed a genomic DNA methylation profile and conducted a DMR analysis under salt stress, which provided valuable information for the better understanding of epigenetics in response to salt stress in cotton.

[Risk factors for hepatitis B recurrence after liver transplantation for HBV-related liver disease]

Objective: To investigate the risk factors for hepatitis B recurrence after liver transplantation for HBV-related liver disease, and to provide a basis for effective preventive measures. Methods: A retrospective analysis was performed for the clinical data of 907 patients with HBV-related liver disease who underwent liver transplantation from April 2002 to December 2013. The chi-square test was used to determine the risk factors for hepatitis B recurrence, and multivariate Cox regression analysis was used for identifying the independent risk factors. Results: There were 907 patients with HBV-related liver disease who underwent liver transplantation. The patients were followed up for 1-144 months, with a median follow-up time of 50.9 months. Among them, 56 experienced hepatitis B recurrence, yielding a recurrence rate of 6.17%. The univariate analysis showed that positive HBeAg before surgery, positive HBV DNA before surgery, positive anti-HBc in liver donor, postoperative tumor recurrence, and postoperative regimen for the prevention of hepatitis B recurrence were significantly correlated with hepatitis B recurrence after liver transplantation (P < 0.05). The multivariate Cox regression analysis showed that positive HBeAg before surgery (OR = 1.891, 95% CI 1.064-3.360, P < 0.05), positive anti-HBc in liver donor (OR = 3.128, 95% CI 1.591-6.151, P < 0.01), and postoperative tumor recurrence (OR = 4.365, 95% CI 2.152-8.857, P < 0.01) were independent risk factors for hepatitis B recurrence. Conclusion: Positive HBeAg before surgery, postoperative tumor recurrence, and positive anti-HBc in liver donor are independent risk factors for hepatitis B recurrence after liver transplantation. For the patients who plan to undergo liver transplantation, antiviral therapy should be given before surgery to reduce HBV viral load, and effective preventive measures after surgery are the key to the prevention and reduction of postoperative hepatitis B recurrence.

[Progress on the Rule of Clavicle Epiphyseal Closure Using Multi-Imaging Technology]

People aged 18 years could be punished lightly or diminished criminal responsibility, even be spared the death sentence, which has important meaning in Chinese judicatory adjudication. The epiphysis of long bones from human limbs and the secondary sexual characteristics almost have developed completely before 18 years old. Clavicle epiphysis is one of the articular metaphysis which has a late epiphyseal closure. The recent studies in exploring the rule of clavicle epiphyseal by multi-imaging technology shows that the development of clavicle epiphysis has some value in age estimation of 18 years old. CT, especially thin-section CT, is widely used at present. However, thin-section CT scanning has great net radiation, which is not ethically acceptable if it is not for diagnosis and treatment. MRI is nonradioactive tomographic imaging and easy to evaluate, which is one of the future research directions in forensic age estimation using the medial clavicle. This paper summarizes the progress on the rule of clavicle epiphyseal closure, and analyzes and summarizes the feasibility of rule of clavicle epiphyseal closure applies on age estimation.

Construction of recombinant adenovirus Ad-rat PLCg2-shRNA and successful suppression of PLCg2 expression in BRL-3A cells

Phospholipase Cg2 (PLCg2) induces apoptosis of immune and tumor cells; however, it remains unclear whether PLCg2 promotes hepatocyte apoptosis during liver regeneration (LR). Therefore, to establish a framework for further exploring the function of PLCg2, we generated recombinant adenoviruses carrying a template encoding short hairpin (sh)-RNA targeting PLCg2 (Ad-PLCg2-shRNA), which were used to silence the expression of PLCg2 in BRL-3A cells. First, three pairs of PLCg2-shRNAs were designed, synthesized, and cloned into a shuttle vector, pHBAd-U6-GFP, after annealing. The recombinant shuttle plasmids were co-transfected with the backbone vector pHBAd-BHG into HK293 cells to package the recombinant Ad-PLCg2-shRNAs used to infect BRL-3A cells. Infection efficiency was monitored by observing the number of GFP-positive cells under a fluorescent microscope. To determine the recombinant adenoviruses with the highest silencing efficiency, levels of PLCg2 mRNA were evaluated by qRT-PCR. DNA sequencing confirmed that the correct shRNA coding sequences were inserted into the shuttle vectors and adenoviral plasmids. The titers of three recombinant adenoviruses were at least 1 x 10(10) PFU/mL. The most effective adenoviral construct, with interference efficiency of 77%, was determined by qRT-PCR. These results show that a recombinant adenovirus, Ad-PLCg2-shRNA, was developed and was effective at silencing the rat PLCg2 gene. This construct may contribute to the study of PLCg2 in hepatocyte apoptosis during LR.

The potential of the human osteopontin promoter and single-nucleotide polymorphisms for targeted cancer gene therapy

Regulatory elements of the osteopontin (opn) gene are attractive candidates for expressiontargeted gene therapy because numerous malignant cancers are marked by opn overexpression. The maximum opn promoter ((P)opn)-driven reporter intensity obtained for tested cancer cell lines was as strong (102.69%) as positive-control transfections. At the same time, (P)opn-driven reporter expression was reduced by ~90% in non-cancer cell lineages. Deletion analysis of the -922 bp region opn promoter did not confirm published reports of a repressor area within 922 bases upstream of the transcriptional start site. Further enhancements to targeting and expression were obtained through incorporation of single-nucleotide polymorphisms (SNPs) into the promoter sequence. It was found that the SNPs -443C, -155GG, -66T led to increased (P)opn-driven transfection in cancer cells (fold increase of 1.23 ~ 3.48), with a concomitant decrease in reporter expression in normal controls (fold change of 0.69). Further investigations to confirm a correlation between endogenous opn mRNA levels and (P)opn-driven reporter expression produced a surprising lack of correlation (R(2)=0.24). However, taking into account opn mRNA splicing variants showed a strong negative correlation between mRNA levels of the variant opn-a and (P) opn-driven transgene activity (R(2)=0.95). These data have implications on how future searches for expression-targeting promoters should be conducted.

A novel mutation links to von Hippel-Lindau syndrome in a Chinese family with hemangioblastoma

Hemangioblastoma of the central nervous system occurs as sporadic tumors or as a part of von Hippel-Lindau (VHL) disease, an autosomal dominant hereditary tumor syndrome caused by a germline mutation in the VHL tumor suppressor gene. We screened a Chinese family with VHL for mutations in the VHL gene and evaluated a genetic test for diagnosing VHL disease and clinical screening of family members. DNA extracted from the peripheral blood of all live members and from tissue of deceased family members with VHL disease was amplified by polymerase chain reaction to 3 VHL gene exons. Mutations in the amplification products were compared against the Human Gene Mutation Database. The involvement of multiple organs among the kindred with VHL disease was confirmed by medical history and radiography. Of the 12 members of the 4-generation family, 5 were diagnosed with VHL disease. Patient age at the initial diagnosis was 26-36 years (mean = 31 years). The mean time was 15 (11-19 months) from symptom appearance to the first patient visit to the hospital. Sequence analysis revealed that the frameshift mutation 327del C (p.Gly39Alafs*26) in exon 1 affected all family members, but not the healthy individuals or 16 unrelated controls. Members without gene mutation showed no clinical manifestation of VHL disease. We detected a conserved novel frameshift mutation in the VHL gene of the family members that contributes to VHL. DNA analysis of VHL is advantageous for VHL diagnosis. We developed a quick and reliable method for VHL diagnosis.

Strain induced modulation of the correlated transport in epitaxial Sm0.5Nd0.5NiO3 thin films

We report a study of the effect of epitaxial strain on the correlated transport properties of 2-40 nm Sm0.5Nd0.5NiO3 (SNNO) films grown on different substrates. The metal-insulator transition (MIT) temperature T(MI) of the SNNO films increases with increasing tensile strain. While films on (0 0 1) LaAlO3 and (1 1 0) NdGaO3 substrates exhibit a sharp MIT and thermal hysteresis in the cooling-heating cycle, signaling a first-order transition, films on (0 0 1) SrTiO3 show a broad, second-order MIT. Hall effect measurements reveal hole-type charge carriers and thermally activated temperature dependence of the carrier density below T(MI). The corresponding activation energy is ∼80 meV for films on LaAlO3 and NdGaO3, and is suppressed to 25 meV for films on SrTiO3. The carrier mobility in the metallic state and variable range hopping (VRH) transport at a low temperature point significantly enhanced electron localization in SNNO on STO, which we believe is not simply driven by extrinsic effects such as oxygen vacancies, but rather is an intrinsic characteristic for films subject to tensile strain due to the elongated Ni-O bond and hence enhanced dynamic Jahn-Teller distortion. In ultrathin films above the electrical dead layer thickness (2-3 nm), we observe a more than 100 K increase of T(MI) for films on LaAlO3, which has been correlated with a crossover from 3D to 2D transport as revealed from VRH. We attribute the distinct transport characteristics to strain induced modulation of various energy scales associated with the Ni-O-Ni bond angle and Ni-O bond length, which collectively determine the delocalization bandwidth of the system.

Gene delivery in tissue engineering and regenerative medicine

As a promising strategy to aid or replace tissue/organ transplantation, gene delivery has been used for regenerative medicine applications to create or restore normal function at the cell and tissue levels. Gene delivery has been successfully performed ex vivo and in vivo in these applications. Excellent proliferation capabilities and differentiation potentials render certain cells as excellent candidates for ex vivo gene delivery for regenerative medicine applications, which is why multipotent and pluripotent cells have been intensely studied in this vein. In this review, gene delivery is discussed in detail, along with its applications to tissue engineering and regenerative medicine. A definition of a stem cell is compared to a definition of a stem property, and both provide the foundation for an in-depth look at gene delivery investigations from a germ lineage angle.

Expression profiles uncover the relevance between colony stimulating factor-mediated signaling pathways in liver cells and partial hepatectomy-induced hepatic regeneration

Colony stimulating factors (CSF) have been considered to modulate liver regeneration (LR) after partial hepatectomy (PH) at the tissue level. However, it remains unclear about precise mechanism of action of CSF in regeneration at the cellular level. Therefore, eight rat liver cell types were isolated by Percoll gradient centrifugation and magnetic beads. CSF-mediated signaling pathway genes were obtained by searching the related pathway databases and their expression profiles in 8 hepatic cell types were measured using rat Genome 230 2.0 Microarray. RT-PCR was performed to assess the reliability of chip results. The result showed a large difference in expression profiles of CSF-mediated signaling pathway genes between different cell types; most genes involved in CSF-mediated signaling pathways were mainly unregulated across liver cell samples. The implication of these genes in LR was analyzed by the bioinformatics and systems biology method. According to chip results and gene synergy, a significant enhancement of the CSF3-mediated Pi3k/Akt pathway at 30-36 h in hepatocytes and at 24 h in biliary epithelial cells post-PH could be associated with active proliferation in these two cell types; the striking decrease in Jak/Stat cascade activity in hepatic stellate cells at 2 and 12 h post- PH or even inactive in dendritric cells during the whole LR implied that proliferation of these two cell types is possibly regulated by other signaling pathways. These data suggest the potential relevance of CSF in liver regeneration at the cellular level.

Model simulation of inflow water to the Baltic Sea based on ¹²⁹I

The semi-enclosed Baltic Sea represents a vital economic and recreational resource for more than 90 million people inhabiting its coasts. Extensive contamination of this sea by a variety of anthropogenic pollutants has raised the concern of the people in the region. Quantifying seawater inflow is crucial for estimating potential environmental risks as well as to find the best remedial strategy. We present here a model to estimate water inflow from the North Sea to the Baltic Sea by utilizing ¹²⁹I as a tracer. The results predicted inflow range of 230-450 km³/y with best fit value around 330 km³/y from the North Sea to the Baltic Sea during 1980-1999. Despite limited time series data on ¹²⁹I, the model presented here demonstrates a new management tool for the Baltic Sea to calculate inflow water compared to conventional methods (such as salinity, temperature and hydrographic models).

Abstract 976: CUDC-101, a hybrid molecular targeted agent, reverses multiple mechanisms of drug resistance

CUDC-101, a hybrid molecular targeted agent, reverses multiple mechanisms of drug resistance

CUDC-101 is a potent molecular targeted anticancer agent, rationally designed to simultaneously inhibit HDAC, EGFR and HER2. It exhibits potent antiproliferative and proapoptotic activities in both in vitro and in vivo assays and it is currently in Phase 1b clinical trial.

Multidrug resistance (MDR) is a major unresolved obstacle to successful cancer chemotherapy. It is often associated with increased ABC transporters-mediated efflux of substrate anticancer drugs out of the cell. Platinum (Pt)-based anticancer drugs, exemplified by cisplatin and oxaliplatin, are the mainstay of treatment for most solid cancers. However, resistance to Pt anticancer drugs develops rapidly upon their administration, which can be caused by overexpression of MDR transporters and activated DNA repair mechanisms.

We investigated the potentiation effect of CUDC-101 on the anticancer activity of conventional cytotoxic drugs in MDR cells with overexpression of various ABC transporters and in Pt-resistant cancer cells. CUDC-101 was found to increase the cytotoxicity and accumulation of substrate anticancer drugs in MPR-1 (doxorubicin) and MRP-2 (methotrexate) overexpressing cells, while no effect was observed in the parental sensitive cells. Mechanistically, CUDC-101 was found to inhibit MRP-1 and MRP-2 efflux function, probably by acting as an uncompetitive inhibitor and interfering with their ATPase activity. In Pt-resistant cancer cells, CUDC-101 appears to circumvent the resistance through inhibition of both MRP-2 and other DNA repair-mediated mechanisms. The combinations of CUDC-101 with cisplatin or oxaliplatin were found to display synergistic cytotoxic effect in cisplatin- or oxaliplatin-resistant cancer cell lines, respectively. Upon the concomitant administration of CUDC-101, cellular accumulation of Pt drugs and formation of DNA-Pt adducts were found to be increased whereas expression levels of DNA repair genes (e.g. ERCC1) was inhibited in Pt-resistant cells. The data advocates further development of CUDC-101 as a novel MDR reversal agent for use in combination cancer chemotherapeutic regimens.

Citation Format: Kenneth K.W. To, Daniel C. Poon, XG Chen, Ge Lin, Li-wu Fu. CUDC-101, a hybrid molecular targeted agent, reverses multiple mechanisms of drug resistance. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 976. doi:10.1158/1538-7445.AM2013-976

Involvement of ERK1/2 signaling in proliferation of eight liver cell types during hepatic regeneration in rats

It has been well established that ERK1/2 signaling, often subdivided into nine types of pathways, can regulate the hepatocyte proliferative response during liver regeneration. However, the effect of ERK1/2 signaling on the proliferation of other hepatic cell types remains unclear. We isolated and purified 8 liver cell types at 10 time points after 2/3 hepatectomy in adult rats. For each cell type, mRNA expression changes for ERK1/2 signaling-involved genes were monitored up to 168 h, using microarrays. Real-time PCR assays were performed for array data verification. The expression levels of these genes varied considerably between different cell types. Integrating microarray results with gene synergical analysis, at the priming phase, activation of integrin/Grb2/Ras pathway in hepatocytes apparently contributed to G0/G1 transition. Two other pathways, G-protein/EPAC/Rap1 and G-protein/PKA/Rap1, were stimulated in hepatic stellate cells, while RTK/PKC/Ras and RTK/Grb2/Ras were stimulated in Kupffer cells. At the progressive phase, the ERK1/2 pathway is involved in hepatocyte replication; three pathways, namely Ca(2+)/PKC/Ras, RTK/Grb2/Ras and G-protein/EPAC/Rap1, were found to play roles in biliary epithelial cell proliferation, while RTK/PKC/Ras and RTK/Grb2/Ras were involved in Kupffer cell proliferation, and G-protein/PKC/Ras in pit cell proliferation. At the terminal phase, the promotive effect of the ERK1/2 pathway on replication of hepatocytes, biliary epithelial cells, oval cells, hepatic stellate cells, Kupffer cells, and dendritic cells was considerably reduced, possibly due to their differentiation at the end of regeneration. G-protein/PKC/Ras, integrin/Grb2/Ras and G-protein/ PKA/Rap1 pathways were active in sinusoidal endothelial cells, perhaps to aid in their proliferation. We conclude that ERK1/2 has a signaling role in the regulation of proliferation of 8 cell types during liver regeneration process.

Differential gene expression and functional analysis of pit cells from regenerating rat liver

Hepatic pit cells are a population of large granular lymphocytes that substantially contribute to hepatic immunity. Studies have proven that pit cells have a role in liver regeneration, but the details of the relationship between pit cells and liver regeneration is not clear at present. We subjected rats to a two-third hepatectomy; pit cells with high purity were obtained with Percoll density centrifugation and immunomagnetic bead methods, and the changes in mRNA levels in pit cells from the regenerating liver were monitored up to 168 h using a Rat Genome 230 2.0 Array composed of 25,020 distinct rat liver cDNA clones. Of the 25,020 genes analyzed, 612 known and 358 unknown genes were identified to be associated with liver regeneration. The 612 known genes are classified into up-regulation and down-regulation patterns based on the expression levels; they primarily participate in at least 23 biological activities based on gene ontology analysis. Together with gene function enrichment analysis, cytokines and a growth factor-mediated pathway in pit cells were activated at an early phase of liver regeneration; pit cell proliferation occurred from 24-72 h after liver hepatectomy; the machinery of pit cell differentiation commenced early and came into play late; an immune/inflammatory response was enhanced late. Expression pattern analysis of functionally classified genes in pit cells can give insights into the relationship between pit cells and liver regeneration.

Seroprevalence of Toxoplasma gondii infection in stray and household cats in Guangzhou, China

The prevalence of anti-Toxoplasma gondii specific IgG in stray and household cats in Guangzhou, China was determined by ELISA on serum samples from 206 cats (117 strays and 89 households) and the overall infection rate was 25.24%. The infection rate in stray cats (30.77%) was significantly higher (P < 0.05) than in household cats (17.98%). The rate of infection between male and female cats of both groups was not significantly different (P > or = 0.05), 28.13% versus 32.61% for male and female in stray cats, respectively, and 18% versus 17.95% in household cats. The present investigation demonstrated that the prevalence of T. gondii infection in cats in Guangzhou was high, especially in stray cats, which are probably the main source of T. gondii infection in this area. Integrated control strategies and measures should be implemented to prevent and control T. gondii infection in both stray and household cats, which will have significant implications for the control of human infection with T. gondii.

Specific PCR assays for the identification of common anisakid nematodes with zoonotic potential

Based on the sequences of the internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA) for six taxa of anisakids, namely, Anisakis simplex (s.s.), Anisakis typica, Anisakis pegreffii, Hysterothylacium aduncum, Hysterothylacium sp, and Contracaccum osculatum C, specific primers were designed in the ITS-1 and/or ITS-2 for each of the six anisakid taxa. These specific primers were used to develop polymerase chain reaction (PCR) tools for the identification of these anisakid taxa of sea fish by amplifying partial ITS-1 and/or ITS-2 of rDNA from anisakid nematodes. This approach allowed their specific identification, with no amplicons being amplified from heterogeneous DNA samples, and sequencing confirmed the identity of the DNA fragments amplified. The minimum amounts of DNA detectable using the PCR assays were 0.5-1 ng. These PCR tools were then applied to ascertain the specific identity of 143 anisakid larval samples collected from fish in China, Canada, Thailand, and Indonesia, and these anisakid samples were identified to represent one of the six anisakid taxa. These PCR assays based on ITS sequences should provide useful molecular tools for the accurate identification and molecular epidemiological investigations of anisakid infections in humans and fish.

Use of activated carbon as a support medium for H2S biofiltration and effect of bacterial immobilization on available pore surface

The use of support media for the immobilization of microorganisms is widely known to provide a surface for microbial growth and a shelter that protects the microorganisms from inhibitory compounds. In this study, activated carbon is used as a support medium for the immobilization of microorganisms enriched from municipal sewage activated sludge to remove gas-phase hydrogen sulfide (H2S), a major odorous component of waste gas from sewage treatment plants. A series of designed experiments is used to examine the effect on bacteria-immobilized activated carbon (termed "biocarbon") due to physical adsorption, chemical reaction, and microbial degradation in the overall removal of H2S. H2S breakthrough tests are conducted with various samples, including microbe-immobilized carbon and Teflon discs, salts-medium-washed carbon, and ultra-pure water-washed carbon. The results show a higher removal capacity for the microbe-immobilized activated carbon compared with the activated carbon control in a batch biofilter column. The increase in removal capacity is attributed to the role played by the immobilized microorganisms in metabolizing adsorbed sulfur and sulfur compounds on the biocarbon, hence releasing the adsorption sites for further H2S uptake. The advantage for activated carbon serving as the support medium is to adsorb a high initial concentration of substrate and progressively release this for microbial degradation, hence acting as a buffer for the microorganisms. Results obtained from surface area and pore size distribution analyses of the biocarbon show a correlation between the available surface area and pore volume with the extent of microbial immobilization and H2S uptake. The depletion of surface area and pore volume is seen as one of the factors which cause the onset of column breakthrough. Microbial growth retardation is due to the accumulation of metabolic products (i.e., sulfuric acid); and a lack of water and nutrient salts in the batch biofilter are other possible causes of column breakthrough.

Removal of odorous sulphur-containing gases by a new isolate from activated sludge

Biological treatment of odorous sulphur-containing compounds is attracting attention due to its benign eco-friendliness, energy-savings and low operating costs. As the biological treatment efficiency of dimethylsulphide (DMS) reported was often low and variable, selection of useful DMS-degrading microorganisms is of importance for the enhancement of the biological deodorizing process. This paper reports the successful isolation of a DMS-degrading bacterium from activated sludge, using the enrichment isolation technique. The isolate was identified by 16S rRNA gene sequencing, and found to belong to the alpha group of Proteobacteria, with an identity of 99.4% and 99.1% to the 16S rRNA gene sequences of Afipia felis and Pseudomonas carboxydohydrogena, respectively. The isolate was able to metabolize DMS as well as hydrogen sulphide (H2S). A batch experiment was performed to assess the removal characteristics of DMS by the isolate. The results showed that over half of DMS could be removed by the isolate in 3 hours when the initial DMS amount was approximately 10 micromol and 25 micromol. Removal of H2S by the isolate was evaluated by a continuous test in a 2-L gas-bubbling bottle. Although part of the H2S removal by the mineral medium itself was observed in the control test, the majority of H2S removal was believed to be attributed to the metabolic activity of the isolate. In conclusion, the isolate might be potentially useful for the enhancement of the biological deodorizing processes.

Batch experiment on H2S degradation by bacteria immobilised on activated carbons

Biological treatments of odorous compounds, as compared to chemical or physical technologies, are in general ecologically and environmentally favourable. However, there are some inefficiencies relative to the media used in biofiltration processes, such as the need for an adequate residence time; the limited lifetime, and pore blockage of media, which at present render the technology economically non-viable. The aim of the study is to develop novel active media to be used in performance-enhanced biofiltration processes, by achieving an optimum balance and combination of the media adsorption capacity with the biodegradation of H2S through the bacteria immobilised on the media. An enrichment culture was obtained from activated sludges in order to metabolise thiosulphate. Batch-wise experiments were conducted to optimise the bacteria immobilisation on activated carbon, so as to develop a novel "biocarbon". Biofilm was mostly developed through culturing the bacteria with the presence of carbons in mineral media. SEM and BET tests of the carbon along with the culturing process were used to identify, respectively, the biofilm development and biocarbon porosity. Breakthrough tests evaluated the biocarbon performance with varying gas resistance time, inlet H2S concentration, and type of support materials. Fundamental issues were discussed, including type of support material, mode of bacteria immobilisation, pore blockages, and biodegradation kinetics, etc. This batch-wise study provides a basis for our future research on optimisation of the biofiltration process using a bio-trickling reactor.

[The construction of recombinant plasmids of Toxoplasma gondii P30 and the immunoprotective activity of the P30 constructs]

OBJECTIVE

To identify the potential DNA vaccine candidate which can induce the protective immune response to Toxoplasma gondii by inoculating mice with plasmid DNAs encoding three different forms of P30 antigen (membranous secretory, and intracellular).

METHODS

Three forms of recombinant plasmid: pcDNA3-P30Mb(contain the whole P30 gene sequence, including the gene encoding signal peptide and hydrophobic tail), pcDNA3-P30Se(contain the whole P30 gene sequence, without the gene encoding hydrophobic tail) and pcDNA3-P30In(contain the whole P30 gene sequence, without the gene encoding signal peptide) were constructed by PCR and subcloning technique. The mice were immunized with different forms of recombinant plasmids and IgG antibodies in the mice were detected by ELISA and Western blotting.

RESULTS

Three forms of expression recombinant plasmid of Toxoplasma gondii P30 gene were successfully constructed. The P30 inserts were identified by restrictive enzyme digestion and sequencing. ELISA and Western blotting analysis demonstrated that specific IgG antibody could be induced in three immunized groups, but there was some difference in appearence time and intensity of IgG.

CONCLUSION

Genetically immunization of mice with the recombinant plasmids could elicit specific IgG antibodies. In respect to IgG response, the immune efficiency of the three forms of recombinant plasmids was different at the beginning (2 wk), but 4 wk later approximately same.

[Purification of soluble egg antigen (SEA) 38 kDa molecule of Schistosoma japonicum and preliminary evaluation of its immunodiagnostic efficacy]

OBJECTIVE

To study the applicability of soluble egg antigen (SEA) 38 kDa molecule of Schistosoma japonicum in the immunodiagnosis of schistosomiasis.

METHODS

The target immunodiagnositic antigen SEA 38 kDa molecule was separated and purified by SDS-PAGE and electroelution technique and evaluated by SDS-PAGE and Western blotting. To compare their immunodiagnostic efficacy, the purified SEA 38 kDa and SEA were used to examine the sera from 182 cases including 31 acute schistosomiasis patients, 31 chronic schistosomiasis patients, 60 normal human controls, 30 paragonimiasis patients and 30 clonorchiasis patients.

RESULTS

The positive rates of purified SEA 38 kDa and SEA for acute schistosomiasis patients, chronic schistosomiasis patients, normal human controls, paragonimiasis patients and clonorchiasis patients were 90.3%, 90.3%, 1.7%, 0, 0 and 90.3%, 83.9%, 3.3%, 0, 0, respectively. The P/N ratio of purified SEA 38 kDa and SEA in immunodiagnosis of schistosomiasis by ELISA had been compared by two-sample t-test. It was demonstrated that there existed significant differences between purified SEA 38 kDa and SEA in the three groups of acute and chronic schistosomiasis patients and normal persons(P < 0.001). The P/N ratio of SEA 38 kDa in detecting the sera from schistosomiasis patients was obviously higher than that of SEA, but when SEA 38 kDa was used to examine normal human sera, the result was converse.

CONCLUSION

The purified SEA 38 kDa has higher sensitivity and specificity and immunodiagnostic potential.

Human marrow stromal cell therapy for stroke in rat: neurotrophins and functional recovery

OBJECTIVE

To test the effect of i.v.-injected human bone marrow stromal cells (hMSC) on neurologic functional deficits after stroke in rats.

METHODS

Rats were subjected to transient middle cerebral artery occlusion and IV injected with 3 x 10(6) hMSC 1 day after stroke. Functional outcome was measured before and 1, 7, and 14 days after stroke. Mixed lymphocyte reaction and the development of cytotoxic T lymphocytes measured the immune rejection of hMSC. A monoclonal antibody specific to human cellular nuclei (mAb1281) was used to identify hMSC and to measure neural phenotype. ELISA analyzed neurotrophin levels in cerebral tissue from hMSC-treated or nontreated rats. Bromodeoxyuridine injections were used to identify newly formed cells.

RESULTS

Significant recovery of function was found in rats treated with hMSC at 14 days compared with control rats with ischemia. Few (1 to 5%) hMSC expressed proteins phenotypic of brain parenchymal cells. Brain-derived neurotrophic factor and nerve growth factor significantly increased, and apoptotic cells significantly decreased in the ischemic boundary zone; significantly more bromodeoxyuridine-reactive cells were detected in the subventricular zone of the ischemic hemisphere of rats treated with hMSC. hMSC induced proliferation of lymphocytes without the induction of cytotoxic T lymphocytes.

CONCLUSION

Neurologic benefit resulting from hMSC treatment of stroke in rats may derive from the increase of growth factors in the ischemic tissue, the reduction of apoptosis in the penumbral zone of the lesion, and the proliferation of endogenous cells in the subventricular zone.

[Expression of c-jun mRNA in brain stem following moderate lateral fluid percussion brain injury in rats]

AIM

To study the expression of c-jun in brain stem following moderate lateral fluid percussion brain injury in rats, and to observe the temporal patterns of its expressions following percussion.

METHODS

Male Sprague-Dawley rats were divided into normal control, sham operation control and injury groups. The rats of injury group subjected to moderate lateral fluid percussion injury (0.2MPa), and then were subdivided into 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h and 12 h groups according to the time elapsed after injury. The expression of c-jun was studied by immunohistochemistry and in situ hybridization.

RESULTS

After percussion for 15 min, Jun positive neurons increased in brain stem progressively. At 5 min after percussion, the induction of c-jun mRNA was increased, remained elevated up to 2h after brain injury and then decreased gradually.

CONCLUSION

The induction and expression of the c-jun in brain stem after fluid percussion brain injury were increased rapidly and lasted for a long time.

Variable effects of nitrous oxide at multiple levels of the central nervous system in goats

The direct and indirect effects of nitrous oxide (N2O) on the nociceptive responses of lumbar dorsal horn neurons, and the indirect effects on midbrain reticular formation (MRF) neurons and thalamic neurons were determined in goats anaesthetized with isoflurane. The technique used enabled the differential delivery of N2O to either the torso or the cerebral circulation, thus allowing assessment of the direct spinal and indirect brain effects of N2O. Systemic delivery of N2O appeared to have divergent effects, facilitating (4/11) or depressing (7/11) the responses of dorsal horn neurons. Such divergent effects were also observed when N2O was differentially delivered to the circulation in the torso (i.e. the spinal cord). Likewise, MRF and thalamic responses to noxious stimulation were variably affected by administration of N2O to the torso, with some cells facilitated (7/13 MRF neurons, 3/8 thalamic neurons) and others depressed (6/13 MRF neurons, 5/8 thalamic neurons). It appears that N2O has variable effects on the caprine CNS. The facilitatory action of N2O might partially explain why it is a relatively weak anaesthetic.

High-level expression and purification of immunogenic recombinant SAG1 (P30) of Toxoplasma gondii in Escherichia coli

Surface antigen 1 (SAG1) of Toxoplasma gondii is a good candidate for diagnosis and vaccine development, but recombinant SAG1 produced in Escheichia coli often loses its specific immunogenicity due to the incorrect folding. In the present study, a truncated SAG1 was highly expressed in E. coli as a fusion protein, about 30% of the total protein of the cell lysate. After a simple purification and refolding procedure, purified rSAG1 can be recognized by human Toxoplasma-infective serum, and ELISA kits constructed by rSAG1 can sensitively and specifically detect toxoplasma infection.

Microdetermination of proteins with the arsenazo-DBN-Al(III) complex by Rayleigh light-scattering technique and application of the method

The determination of proteins with arsenazo-DBN and Al3+ by Rayleigh light-scattering (RLS) is described. The weak RLS of arsenazo-DBN and BSA can be enhanced greatly by addition of Al3+ in the pH range 5.3-7.0; this resulted in two enhanced RLS signals at 420-440 nm and 460-480 nm. The reaction between arsenazo-DBN, Al3+, and proteins was studied and a new method was developed for quantitative determination of proteins. This method is very sensitive (0.34-41.71 microg mL(-1) for bovine serum albumin, BSA, and 0.29-53.41 microg mL(-1) for human serum albumin, HSA), rapid (< 2 min), simple (one step), and tolerant of most interfering substances. The effects of different surfactants were also examined. When these proteins were determined in four human serum samples the maximum relative error was not more than 2% and the recovery was between 97 and 103%.

Thiopental directly depresses lumbar dorsal horn neuronal responses to noxious mechanical stimulation in goats

BACKGROUND

Thiopental has hypnotic actions in the brain, but it also depresses nociceptive transmission. In this study we examined whether thiopental had direct (spinal) and/or indirect (supraspinal) effects on the responses of single lumbar dorsal horn neurons to noxious mechanical stimulation, using a method to deliver thiopental differentially to either the torso or cranial circulation in goats.

METHODS

Goats (n=10) were anesthetized with isoflurane and neck dissections performed to permit cranial bypass. A lumbar laminectomy was made to permit single-unit recording of lumbar dorsal horn neuronal activity (1-2 neurons/animal). Isoflurane was maintained at 0.8+/-0.1% to both head and torso throughout the study. During cranial bypass, thiopental was separately administered to the torso (low dose, 1.5+/-0.5 mg/kg; high dose, 3.7+/-0.5 mg/kg) or cranial (low dose, 0.12+/-0.03 mg/kg; high dose, 0.2 mg/kg) circulation.

RESULTS

Thiopental administered to the torso significantly depressed dorsal horn neuronal responses to noxious stimulation at the high dose: 757+/-471 to 392+/-305 impulses/min at 1 min post-injection, P<0.006 (n=14); evoked responses recovered at 5 min post-injection. At the low dose, there was a similar numerical decrease, but this did not reach significance: 876+/-780 to 407+/-499 impulses/min at 1 min post-injection, P>0.05 (n=6). No significant change was observed when thiopental was administered to the cranial circulation: low dose, 1061+/-1167 to 965+/-874 impulses/min at 1 min post-injection, P>0.05 (n=10); high dose, 864+/-331 to 917+/-525 impulses/min at 1 min post-injection, P>0.05 (n=8).

CONCLUSION

Thiopental has a direct (spinal) depressant effect on dorsal neuronal responses to noxious stimulus, but no significant supraspinal effect.