[Comparison of application effects of colonoscopy, fecal immunochemical test and a novel risk-adapted screening approach in colorectal cancer screening in Xuzhou population].

Objective: To compare the application effect of the colonoscopy, fecal immunochemical test (FIT) and novel risk-adapted screening approach in colorectal cancer screening in Xuzhou population. Methods: From May 2018 to April 2019, 4 280 subjects aged 50-74 were recruited from Gulou district, Yunlong district and Quanshan district of Xuzhou. They were randomly assigned to the colonoscopy group (n=863), FIT group (n=1 723) and novel risk-adapted screening approach group (n=1 694) according to the ratio of 1∶2∶2. For the novel risk-adapted screening approach group, after the risk assessment, high-risk subjects were invited to undergo colonoscopy and low-risk subjects were invited to undergo FIT examination. All FIT positive subjects were invited to undergo colonoscopy. Colonoscopy participation rate [(the number of colonoscopies completed/the number of colonoscopies invited to participate)×100%], detection rate of colorectal lesions [(the number of diagnosed patients/the number of colonoscopies completed)×100%], colonoscopy resource load (the number of colonoscopies completed/the number of diagnosed advanced tumors) and FIT resource load in each group were calculated and compared. Results: The age of all subjects was (61±6) years old, including 1 816 males (42.43%). There was no statistically significant difference in the socio-demographic characteristics of the subjects in different screening groups. The colonoscopy participation rate was 22.60% (195/863) in the colonoscopy group, 57.04% (77/135) in the FIT group, and 33.94% (149/439) in the novel risk-adapted screening approach group, respectively. The colonoscopy participation rate was higher in the FIT group than in the colonoscopy group and the novel risk-adapted screening approach group (P<0.001). The colonoscopy participation rate of novel risk-adapted screening group was significantly higher than the colonoscopy group (P<0.001). The detection rates of advanced tumors were 6.67% (13/195), 9.09% (7/77) and 8.72% (13/149), respectively, and the difference was not statistically significant (P>0.05). The colonoscopy resource load (95%CI) was 15 (13-17) in the colonoscopy group, 11 (9-14) in the FIT group and 11 (10-13) in the novel risk-adapted screening approach group, respectively. Among them, the colonoscopy resource load of high-risk individuals in the novel risk-adapted screening approach group was 12 (9-15). FIT resource loads (95%CI) were 207 (196-218) and 88 (83-94) in the FIT group and the novel risk-adapted screening approach group. Conclusion: The combined application of risk-adapted screening approach and FIT may have a good application effect in colorectal cancer screening.

The effect of tranexamic acid on artificial joint materials: a biomechanical study (the bioTRANX study).

BACKGROUND: Tranexamic acid (TXA) has been successfully used to reduce bleeding in joint replacement. Recently local TXA has been advocated to reduce blood loss in total knee or hip replacement; however, this raised concerns about potential adverse effects of TXA upon the artificial joint replacement. MATERIALS AND METHODS: In this biomechanical study we compared the effects of TXA and saline upon the following biomechanical properties of artificial joint materials-(1) tensile properties (ultimate strength, stiffness and Young's modulus), (2) the wear rate using a multi-directional pin-on-plate machine, and (3) the surface topography of pins and plates before and after wear rate testing. RESULTS: There were no significant differences in tensile strength, wear rates or surface topography of either ultra-high-molecular-weight polyethylene pins or cobalt chromium molybdenum metal plates between specimens soaked in TXA and specimens soaked in saline. CONCLUSION: Biomechanical testing shows that there are no biomechanical adverse affects on the properties of common artificial joint materials from using topical TXA. LEVEL OF EVIDENCE: V.

Multisensory flicker modulates widespread brain networks and reduces interictal epileptiform discharges.

Modulating brain oscillations has strong therapeutic potential. Interventions that both non-invasively modulate deep brain structures and are practical for chronic daily home use are desirable for a variety of therapeutic applications. Repetitive audio-visual stimulation, or sensory flicker, is an accessible approach that modulates hippocampus in mice, but its effects in humans are poorly defined. We therefore quantified the neurophysiological effects of flicker with high spatiotemporal resolution in patients with focal epilepsy who underwent intracranial seizure monitoring. In this interventional trial (NCT04188834) with a cross-over design, subjects underwent different frequencies of flicker stimulation in the same recording session with the effect of sensory flicker exposure on local field potential (LFP) power and interictal epileptiform discharges (IEDs) as primary and secondary outcomes, respectively. Flicker focally modulated local field potentials in expected canonical sensory cortices but also in the medial temporal lobe and prefrontal cortex, likely via resonance of stimulated long-range circuits. Moreover, flicker decreased interictal epileptiform discharges, a pathological biomarker of epilepsy and degenerative diseases, most strongly in regions where potentials were flicker-modulated, especially the visual cortex and medial temporal lobe. This trial met the scientific goal and is now closed. Our findings reveal how multi-sensory stimulation may modulate cortical structures to mitigate pathological activity in humans.

Impaired long-term quality of life in survivors of severe sepsis : Chinese multicenter study over 6 years.

OBJECTIVES: The present study was undertaken to evaluate the long-term health-related quality of life (HRQOL) as well as the employment status in survivors of severe sepsis up to 6 years afterwards. MATERIAL AND METHODS: From January 2003 to December 2008 a total of 112 severe sepsis and 112 age, gender and Charlson comorbidity index-matched non-septic critically ill patients from 4 university hospital intensive care units (ICU) were enrolled in the study and 126 age and gender-matched community residents were interviewed as the community control group. RESULTS: A total of 66 (58.9 %) severe sepsis and 80 (71.4 %) non-sepsis critically ill patients survived during the long-term follow-up time. Between August and December 2010 a total of 75 patients including 42 survivors of severe sepsis and 33 critically ill controls completed the face-to-face interview. There were no differences in the long-term HRQOL in terms of Short-Form 36 criteria between severe sepsis and non-sepsis critically ill survivors. However, when compared with the community controls, HRQOL in survivors of severe sepsis showed a significantly and clinically meaningful decrease, with a lower physical functioning (p = 0.016), vitality (p = 0.037), role-emotional (p = 0.043), mental health (p = 0.038) and mental component scores (p = 0.042). In addition, the criteria returning to work at 1 year and at the time of interview in severe sepsis survivors were similar with those in critically ill survivors (60.5 % vs. 70.0 %, p = 0.41 and, 71.1 % vs. 76.7 %, p = 0.602). CONCLUSIONS: The HRQOL in survivors of severe sepsis was impaired even up to 6 years after hospital discharge.

Neurological complications of COVID-19.

Corona Virus Disease 2019 (COVID-19) has caused several pandemic peaks worldwide due to its high variability and infectiousness, and COVID-19 has become a long-standing global public health problem. There is growing evidence that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) frequently causes multi-organ injuries and more severe neurological manifestations. Therefore, increased awareness of possible neurological complications is beneficial in preventing and mitigating the impact of long-term sequelae and improving the prognostic outcome of critically ill patients with COVID-19. Here, we review the main pathways of SARS-CoV-2 neuroinvasion and the potential mechanisms causing neurological damage. We also discuss in detail neurological complications, aiming to provide cutting-edge basis for subsequent related basic research and clinical studies of diagnosis and treatment.

Protocol for Classification Single-Cell PBMC Types from Pathological Samples Using Supervised Machine Learning.

Peripheral blood mononuclear cells (PBMC) are mixed subpopulations of blood cells composed of five cell types. PBMC are widely used in the study of the immune system, infectious diseases, cancer, and vaccine development. Single-cell transcriptomics (SCT) allows the labeling of cell types by gene expression patterns from biological samples. Classifying cells into cell types and states is essential for single-cell analyses, especially in the classification of diseases and the assessment of therapeutic interventions, and for many secondary analyses. Most of the classification of cell types from SCT data use unsupervised clustering or a combination of unsupervised and supervised methods including manual correction. In this chapter, we describe a protocol that uses supervised machine learning (ML) methods with SCT data for the classification of PBMC cell types in samples representing pathological states. This protocol has three parts: (1) data preprocessing, (2) labeling of reference PBMC SCT datasets and training supervised ML models, and (3) labeling new PBMC datasets from disease samples. This protocol enables building classification models that are of high accuracy and efficiency. Our example focuses on 10× Genomics technology but applies to datasets from other SCT platforms.

Assessing Freshwater Microbiomes from Different Storage Sources in the Caribbean Using DNA Metabarcoding.

Next-generation sequencing (NGS) and the technique of DNA metabarcoding have provided more efficient and comprehensive options for testing water quality compared to traditional methods. Recent studies have shown the efficacy of DNA metabarcoding in characterizing the bacterial microbiomes of varied sources of drinking water, including rivers, reservoirs, wells, tanks, and lakes. We asked whether DNA metabarcoding could be used to characterize the microbiome of different private sources of stored freshwater on the Caribbean Island nation of Antigua and Barbuda. Two replicate water samples were obtained from three different private residential sources in Antigua: a well, an above-ground tank, and a cistern. The bacterial microbiomes of different freshwater sources were assessed using 16S rRNA metabarcoding. We measured both alpha diversity (species diversity within a sample) and beta diversity (species diversity across samples) and conducted a taxonomic analysis. We also looked for the presence of potentially pathogenic species. Major differences were found in the microbiome composition and relative abundances depending on the water source. A lower alpha diversity was observed in the cistern sample compared to the others, and distinct differences in the microbiome composition and relative abundance were noted between the samples. Notably, pathogenic species, or genera known to harbor such species, were detected in all the samples. We conclude that DNA metabarcoding can provide an effective and comprehensive assessment of drinking water quality and has the potential to identify pathogenic species overlooked using traditional methods. This method also shows promise for tracing the source of disease outbreaks due to waterborne microorganisms. This is the first study from small island countries in the Caribbean where metabarcoding has been applied for assessing freshwater water quality.

Multisensory Flicker Modulates Widespread Brain Networks and Reduces Interictal Epileptiform Discharges in Humans.

Modulating brain oscillations has strong therapeutic potential. However, commonly used non-invasive interventions such as transcranial magnetic or direct current stimulation have limited effects on deeper cortical structures like the medial temporal lobe. Repetitive audio-visual stimulation, or sensory flicker, modulates such structures in mice but little is known about its effects in humans. Using high spatiotemporal resolution, we mapped and quantified the neurophysiological effects of sensory flicker in human subjects undergoing presurgical intracranial seizure monitoring. We found that flicker modulates both local field potential and single neurons in higher cognitive regions, including the medial temporal lobe and prefrontal cortex, and that local field potential modulation is likely mediated via resonance of involved circuits. We then assessed how flicker affects pathological neural activity, specifically interictal epileptiform discharges, a biomarker of epilepsy also implicated in Alzheimer's and other diseases. In our patient population with focal seizure onsets, sensory flicker decreased the rate interictal epileptiform discharges. Our findings support the use of sensory flicker to modulate deeper cortical structures and mitigate pathological activity in humans.

Lateral inhibition in V1 controls neural & perceptual contrast sensitivity.

Lateral inhibition is a central principle for sensory system function. It is thought to operate by the activation of inhibitory neurons that restrict the spatial spread of sensory excitation. Much work on the role of inhibition in sensory systems has focused on visual cortex; however, the neurons, computations, and mechanisms underlying cortical lateral inhibition remain debated, and its importance for visual perception remains unknown. Here, we tested how lateral inhibition from PV or SST neurons in mouse primary visual cortex (V1) modulates neural and perceptual sensitivity to stimulus contrast. Lateral inhibition from PV neurons reduced neural and perceptual sensitivity to visual contrast in a uniform subtractive manner, whereas lateral inhibition from SST neurons more effectively changed the slope (or gain) of neural and perceptual contrast sensitivity. A neural circuit model identified spatially extensive lateral projections from SST neurons as the key factor, and we confirmed this with direct subthreshold measurements of a larger spatial footprint for SST versus PV lateral inhibition. Together, these results define cell-type specific computational roles for lateral inhibition in V1, and establish their unique consequences on sensitivity to contrast, a fundamental aspect of the visual world.

Outcomes of maintenance therapy with tacrolimus versus azathioprine for active lupus nephritis: a multicenter randomized clinical trial.

AIM: The optimal maintenance therapy for active diffuse lupus nephritis remains to be established. In this study, we explored the efficacy and safety of tacrolimus for maintaining remission of active lupus nephritis compared to that of azathioprine. METHODS: Seventy patients with biopsy-proven lupus nephritis who achieved remission were enrolled in nine nephrology centers in China from 2006 to 2008. Patients were randomized either to tacrolimus plus prednisone (n = 34) or azathioprine plus prednisone (n = 36) for six months. Tacrolimus was titrated to achieve a trough blood concentration of 4-6 ng/mL, and the dosage of azathioprine was 2 mg/kg/d. Prednisone was administered at a dose of 10 mg/d to both groups. The primary outcome was incidence of relapse. Response, clinical parameters and adverse effects were secondary endpoints. RESULTS: After six months of therapy, two of the azathioprine-treated patients developed renal relapse compared to none of the tacrolimus-treated patients (p = 0.49; odds ratio, 1.06; 95% CI (0.98, 1.15)). Leucopenia (defined as < 2000 cells per cubic millimeter) was significantly more frequent in the azathioprine group than the tacrolimus group (47% vs. 9%, p < .001). CONCLUSION: In conjunction with prednisone, maintenance therapy with tacrolimus and azathioprine has a similar low rate of renal relapse, and the tacrolimus regimen has a more favorable safety profile, with less leucopenia. However, since our study lacked sufficient power, longer follow-up is needed to draw final conclusions.

Comparison of prediction equations to estimate glomerular filtration rate in Chinese patients with chronic kidney disease.

AIM: We sought to evaluate the applicability of formulae based on serum creatinine (SC) levels in Chinese patients with chronic kidney disease (CKD). MATERIALS AND METHODS: Three hundred and twenty-seven patients with CKD who had undergone (99m) Tc-DTPA glomerular filtration rate (GFR) estimation were enrolled. The Cockcroft-Gault equation, SC-reciprocal equation, Gate equation, Hull equation, Jelliffe-1973 equation, Jelliffe-1971 equation, Mawer equation, Bjornsson equation, reexpressed 6-variable MDRD equation and reexpressed 4-variable MDRD equation were compared. Using the (99m) Tc-DTPA GFR as the standard GFR (sGFR), the accuracy of estimated GFR was compared with sGFR in various stages of CKD. RESULTS: Median per cents of the absolute difference ranged from 28.16% to 39.39%, accuracy with a deviation less than 30% ranging from 39.4% to 53.5%, accuracy with a deviation less than 50% ranging from 63.0% to 80.7%. None of the equations had accuracy up to the 70% level with a deviation less than 30% from sGFR. Bland-Altman analysis demonstrated that mean difference ranged from -2.42 to 16.39 mL/min/1.73 m(2), whereas precision ranged from 82.66 to 106.15 mL/min/1.73 m(2). However, the agreement limits of all the equations exceeded the prior acceptable tolerances defined as 60 mL/min/1.73 m(2). Linear regression showed that the slopes of regression line ranged from 0.37 to 0.54 and intercepts ranged from -12.10 to 3.86. When the overall performance as well as bias and accuracy were compared in different stages of CKD, GFR estimated by Jelliffe-1973 equation, Cockcroft-Gault equation and Bjornsson equation showed promising results. CONCLUSION: When SC was measured by the enzymatic method, GFR estimation equations showed great bias in Chinese CKD patients. At present, the Jelliffe-1973 equation and Cockcroft-Gault equation may be more accurate in the Chinese ethnic group.

Deep brain stimulation of hypothalamus for narcolepsy-cataplexy in mice.

BACKGROUND: Narcolepsy type 1 (NT1, narcolepsy with cataplexy) is a disabling neurological disorder caused by loss of excitatory orexin neurons from the hypothalamus and is characterized by decreased motivation, sleep-wake fragmentation, intrusion of rapid-eye-movement sleep (REMS) during wake, and abrupt loss of muscle tone, called cataplexy, in response to sudden emotions. OBJECTIVE: We investigated whether subcortical stimulation, analogous to clinical deep brain stimulation (DBS), would ameliorate NT1 using a validated transgenic mouse model with postnatal orexin neuron degeneration. METHODS: Using implanted electrodes in freely behaving mice, the immediate and prolonged effects of DBS were determined upon behavior using continuous video-electroencephalogram-electromyogram (video/EEG/EMG) and locomotor activity, and neural activation in brain sections, using immunohistochemical labeling of the immediate early gene product c-Fos. RESULTS: Brief 10-s stimulation to the region of the lateral hypothalamus and zona incerta (LH/ZI) dose-responsively reversed established sleep and cataplexy episodes without negative sequelae. Continuous 3-h stimulation increased ambulation, improved sleep-wake consolidation, and ameliorated cataplexy. Brain c-Fos from mice sacrificed after 90 min of DBS revealed dose-responsive neural activation within wake-active nuclei of the basal forebrain, hypothalamus, thalamus, and ventral midbrain. CONCLUSION: Acute and continuous LH/ZI DBS enhanced behavioral state control in a mouse model of NT1, supporting the feasibility of clinical DBS for NT1 and other sleep-wake disorders.

Mesangial medium with IgA1 from IgA nephropathy inhibits nephrin expression in mouse podocytes.

BACKGROUND: IgA nephropathy (IgAN) is characterized by mesangial deposition of polymeric IgA1, and podocyte injury plays an important role in glomerulosclerosis of the disease. Our previous study indicated that medium of mesangial cells co-incubated with aggregated IgA1 (aIgA1), isolated from IgAN patients, down-regulated nephrin expression. Yet the mechanism remains unclear. MATERIALS AND METHODS: Podocytes were incubated with a medium of mesangial cells co-incubated with aIgA1, which was isolated from IgAN patients, and enalaprilat (10(-5) M), valsartan (10(-5) M) and anti-mouse tumour necrosis factor-alpha antibody (50 ng mL(-1)) separately. Nephrin expression in podocytes was measured by real-time polymerase chain reaction and Western blot analysis. RESULTS: The level of angiotensinogen and angiotensin-converting enzyme mRNAs in podocytes, as well as angiotensin, was also increased by a medium of mesangial cells co-incubated with aIgA1 from IgAN patients (P<0.05). Enalaprilat or valsartan partly improved nephrin expression when compared with that by podocytes exposed to the mesangial medium (P<0.05), while the nephrin expression of podocytes with enalaprilat or valsartan was lower than that of podocytes exposed to medium of mesangial cells stimulated by aIgA1 from healthy control (P<0.05). However, anti-mouse tumour necrosis factor-alpha antibody did not show any improvement in nephrin expression. CONCLUSION: Our findings implicate that local renin angiotensin system activation in podocytes is partly involved in down-regulation of nephrin by mesangial medium in IgA nephropathy.

Molecular characterization of toxigenic and atoxigenic Aspergillus flavus isolates, collected from peanut fields in China.

AIMS: The objectives of this study were to assess the genetic relationships between toxigenic and atoxigenic isolates of Aspergillus flavus collected from peanut fields in China, and to analyse deletions within the aflatoxin biosynthetic gene cluster for the atoxigenic isolates. METHODS AND RESULTS: Analysis of random-amplified polymorphic DNA and microsatellite-primed PCR data showed that the toxigenic and atoxigenic isolates of A. flavus were not clustered based on their regions and their ability of aflatoxin and sclerotial production. These results were further supported by DNA sequence of ITS, pksA and omtA genes. PCR assays showed that 24 of 35 isolates containing no detectable aflatoxins had the entire aflatoxin gene cluster. Eleven atoxigenic isolates had five different deletion patterns in the cluster. CONCLUSIONS: Toxigenic and atoxigenic isolates of A. flavus are genetically similar, but some atoxigenic isolates having deletions within the aflatoxin gene cluster can be identified readily by PCR assays. SIGNIFICANCE AND IMPACT OF THE STUDY: Because the extensive deletions within the aflatoxin gene cluster are not rare in the atoxigenic isolates, analysis of deletion within the cluster would be an effective method for the rapid screening of atoxigenic isolates for developing biocontrol agents.

Staged distraction osteogenesis followed by arthrodesis using internal fixation as a form of surgical treatment for complex conditions of the ankle.

Aims: The aim of this study was to describe the technique of distraction osteogenesis followed by arthrodesis using internal fixation to manage complex conditions of the ankle, and to present the results of this technique. Patients and Methods: Between 2008 and 2014, distraction osteogenesis followed by arthrodesis using internal fixation was performed in 12 patients with complex conditions of the ankle due to trauma or infection. There were eight men and four women: their mean age was 35 years (23 to 51) at the time of surgery. Bone healing and functional recovery were evaluated according to the criteria described by Paley. Function was assessed using the ankle-hindfoot scale of the American Orthopedic Foot and Ankle Society (AOFAS). Results: A solid fusion of the ankle and eradication of infection was achieved in all patients. A mean lengthening of 6.1 cm (2.5 to 14) was achieved at a mean follow-up of 25.2 months (14 to 37). The mean external fixation index (EFI) was 42 days/cm (33.3 to 58). The function was judged to be excellent in six patients and good in six patients. Bone results were graded as excellent in ten patients and good in two patients. The mean AOFAS score was 37.3 (5 to 77) preoperatively and 75.3 (61 to 82) at the final follow-up. Minor complications, which were treated conservatively, included pain, pin-tract infection, loosening of wires, and midfoot stiffness. Major complications, which were treated surgically included grade V pin-tract infection with inflammation and osteolysis, poor consolidation of the regenerate bone, and soft-tissue invagination. The reoperations required to treat the major complications included the exchange of pins and wires, bone grafting and invagination split surgery. Conclusion: The technique of distraction osteogenesis followed by arthrodesis using internal fixation is an effective form of treatment for the management of complex conditions of the ankle. It offers a high rate of union, an opportunity to remove the frame early, and a reduced EFI without infection or wound dehiscence. Cite this article: Bone Joint J 2018;100-B:755-60.

[Survey of the third Zika virus disease case in the mainland of China].

OBJECTIVE: To evaluate the performance of Zika virus(ZIKV)disease prevention and control. METHODS: Descriptive epidemiological analysis was conducted on the clinical manifestations, laboratory detection results and disease progression of the third imported ZIKV disease case in the mainland of China. RESULTS: On 19 February 2016, a ZIKV disease case was confirmed in Yiwu, Zhejiang province, which was the third imported case of ZIKV disease confirmed by China CDC laboratory and expert consulting. The patient just had a travel to Fiji and Samoa and had mosquito bite history in Samoa. The patient was hospitalized on 16 February after the onset on 14 February and the eruption on 15 February. The body temperature of the patient became normal on 17 February, the rash disappeared on 19 February and the conjunctivitis resolved on 20 February. The positive detection of the viral nucleic acid in blood was only for 3 consecutive days, and the viral nucleic acid could be detected in urine even after negative detection in blood for 4 days. CONCLUSION: The symptoms of the patient were typical. ZIKV can be detected by using blood sample in early phase, but after body temperature become normal, the virus can be detected in urine.

[A surveillance study on CRISPR/Cas molecular biomarker in Escherichia coli].

OBJECTIVE: A new method related to molecular biomarker with CRISPR/Cas (clustered regularly interspaced short palindromic repeats-cas) in Escherichia (E.) coli was developed and used for surveillance programs. METHODS: CRISPR/Cas sequence that containing 135 strains with complete sequence and 203 strains with whole genome shotgun sequence of E. coli in GenBank by BLAST and 361 strains of E. coli (including 38 strains of E. coli O157∶H7) in laboratory were identified by PCR and analyzed with the CRISPR Finder. Spacers were compared with DANMAN and the phylogenetic trees of cas gene were constructed under Clustal Ⅹ and Mega 5.1. RESULTS: With new perspective, a descriptive method was developed targeting on the position of CRISPR/cas in E. coli. The CRISPR1 was detected in 77.04%, 100.00% and 75.62% and the CRISPR2 was detected in 74.81%, 100.00% and 92.24% and the CRISPR3 and CRISPR4 were detected in 11.85%, 0 and 1.39% for 135 strains with complete sequence, 203 strains with whole genome shotgun sequence and 361 strains in the laboratory, respectively. One strain downloaded in GenBank with whole genome sequencing and 2 strains in the our laboratory were identified that containing four CRISPR locus. The other E. coli strain was with insertion sequence in downstream of the non-cas CRISPR1. The unique CRISPR was found in 8 strains of O55∶H7, in 180 strains of O157∶H7, in 8 strains of O157∶HNM, in 40 strains of O104∶H4, in 4 strains of O145∶H28, in all the 699 E. coli strains. The phylogenetic tree could be divided into two groups-cas with type I-E or type I-F. CONCLUSIONS: CRISPR/Cas might be used as a valuable molecular biomarker in epidemiological surveillance studies to identify the high virulent strains or new strains of E. coli. Phage night be related to the missing or obtaining of spacers.

Erk pathway inhibitor U0126 induces gamma-globin expression in erythroid cells.

Fetal hemoglobin (HbF) induction is an effective approach to improve clinical symptoms in sickle cell disease. Understanding molecular mechanisms for gamma-gene re-activation will aid efforts to design lead compounds. A potential inhibitory role for the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway in gamma-gene expression has been suggested recently. Therefore, we determined the ability of U0126, a selective inhibitor of MEK1/2 the upstream activators of ERK, to re-activate gamma-globin expression. K562 stable lines over-expressing constitutively active MEK1 were established. A significant increase in ERK phosphorylation was observed and gamma-gene expression was silenced concomitantly, however U0126 attenuated this effect. Studies in human erythroid progenitors confirmed the ability of U0126 to induce HbF. Cellular mechanisms for the inhibitory role of ERK signaling in drug-mediated HbF induction will be discussed.

D-D neutron generator development at LBNL.

The plasma and ion source technology group in Lawrence Berkeley National Laboratory is developing advanced, next generation D-D neutron generators. There are three distinctive developments, which are discussed in this presentation, namely, multi-stage, accelerator-based axial neutron generator, high-output co-axial neutron generator and point source neutron generator. These generators employ RF-induction discharge to produce deuterium ions. The distinctive feature of RF-discharge is its capability to generate high atomic hydrogen species, high current densities and stable and long-life operation. The axial neutron generator is designed for applications that require fast pulsing together with medium to high D-D neutron output. The co-axial neutron generator is aimed for high neutron output with cw or pulsed operation, using either the D-D or D-T fusion reaction. The point source neutron generator is a new concept, utilizing a toroidal-shaped plasma generator. The beam is extracted from multiple apertures and focus to the target tube, which is located at the middle of the generator. This will generate a point source of D-D, T-T or D-T neutrons with high output flux. The latest development together with measured data will be discussed in this article.

Decreased efficiency of gamma-ray-induced DNA double-strand break rejoining in malignant transformants of human bronchial epithelial cells generated by alpha-particle exposure.

PURPOSE: To investigate the cytogenetic changes and DNA double-strand break (DSB) rejoining of transformed cell lines generated from human bronchial epithelial cells by alpha-particle exposure. MATERIALS AND METHODS: Transformed cell lines were derived from the HPV 18-immortalized human bronchial epithelial cell line BEP2D generated by 1.5 Gy of alpha-particles emitted by a 238Pu source. Two cell lines, BERP35T1 and BERP35T4, were investigated. Karyotypes were analyzed by trypsin/Giemsa banding. Cell survival was estimated by colony assay. PFGE was used to detect the DNA DSB. mRNA expression was analyzed by RT-PCR. RESULTS: Abnormal chromosomes 2 and 12 with elongated long arm and deletions of chromosomes 2, 12, 13 and 17 were observed in the transformed cell lines. BERP35T4 showed a much higher proportion of polyploid cells (40.5%) compared with parental BEP2D cells and the BERP35TI cell line (5%). BERP35T1 and BERP35T4 showed a markedly lower capacity for rejoining of gamma-ray-induced DNA DSB and increased radiosensitivity compared with parental BEP2D cells. The analysis of mRNA levels revealed a 2.5- to 6.5-fold down-regulated expression of the DNA repair genes XRCC-2, XRCC-3 and Ku80 in BERP35T1 and BERP35T4 cells. CONCLUSION: The karyotypic changes of chromosomes 2, 12, 13 and 17 and the deficiency of DSB rejoining could be related to the malignant transformation processing of BEP2D cells initiated by alpha-particle exposure.