Performance of the new biological small- and wide-angle X-ray scattering beamline 13A at the Taiwan Photon Source.

Recent developments in the instrumentation and data analysis of synchrotron small-angle X-ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular tool in structural biology. This article reports on an advanced endstation developed at beamline 13A of the 3.0 GeV Taiwan Photon Source for biological small- and wide-angle X-ray scattering (SAXS-WAXS or SWAXS). The endstation features an in-vacuum SWAXS detection system comprising two mobile area detectors (Eiger X 9M/1M) and an online size-exclusion chromatography system incorporating several optical probes including a UV-Vis absorption spectrometer and refractometer. The instrumentation and automation allow simultaneous SAXS-WAXS data collection and data reduction for high-throughput biomolecular conformation and composition determinations. The performance of the endstation is illustrated with the SWAXS data collected for several model proteins in solution, covering a scattering vector magnitude q across three orders of magnitude. The crystal-model fittings to the data in the q range ∼0.005-2.0 Å-1 indicate high similarity of the solution structures of the proteins to their crystalline forms, except for some subtle hydration-dependent local details. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.

Optical design and performance of the biological small-angle X-ray scattering beamline at the Taiwan Photon Source.

The optical design and performance of the recently opened 13A biological small-angle X-ray scattering (SAXS) beamline at the 3.0 GeV Taiwan Photon Source of the National Synchrotron Radiation Research Center are reported. The beamline is designed for studies of biological structures and kinetics in a wide range of length and time scales, from angstrom to micrometre and from microsecond to minutes. A 4 m IU24 undulator of the beamline provides high-flux X-rays in the energy range 4.0-23.0 keV. MoB4C double-multilayer and Si(111) double-crystal monochromators (DMM/DCM) are combined on the same rotating platform for a smooth rotation transition from a high-flux beam of ∼4 × 1014 photons s-1 to a high-energy-resolution beam of ΔE/E ≃ 1.5 × 10-4; both modes share a constant beam exit. With a set of Kirkpatrick-Baez (KB) mirrors, the X-ray beam is focused to the farthest SAXS detector position, 52 m from the source. A downstream four-bounce crystal collimator, comprising two sets of Si(311) double crystals arranged in a dispersive configuration, optionally collimate the DCM (vertically diffracted) beam in the horizontal direction for ultra-SAXS with a minimum scattering vector q down to 0.0004 Å-1, which allows resolving ordered d-spacing up to 1 µm. A microbeam, of 10-50 µm beam size, is tailored by a combined set of high-heat-load slits followed by micrometre-precision slits situated at the front-end 15.5 m position. The second set of KB mirrors then focus the beam to the 40 m sample position, with a demagnification ratio of ∼1.5. A detecting system comprising two in-vacuum X-ray pixel detectors is installed to perform synchronized small- and wide-angle X-ray scattering data collections. The observed beamline performance proves the feasibility of having compound features of high flux, microbeam and ultra-SAXS in one beamline.

Cost of inpatient rehabilitation for children with moderate to severe traumatic brain injury.

AIM: To evaluate the cost of inpatient rehabilitation for children with moderate to severe traumatic brain injury (TBI). Secondary aim was to identify factors associated with high inpatient rehabilitation cost. METHOD: Retrospective review of a tertiary hospital's trauma registry was performed from 2011-2017. All patients aged 16 years or younger who sustained TBI with Glasgow Coma Scale ≤13 were included. Data on patient demographics, mechanism and severity of injury, hospital duration and inpatient rehabilitation cost were collected. We performed a regression analysis to identify factors associated with high rehabilitation cost. RESULTS: There were a total of 51 patients. The median duration of inpatient rehabilitation was 13.5 days (interquartile range [IQR] 4-35), amounting to a median cost of SGD8,361 (IQR 3,543-25,232). Daily ward costs contributed the most to total inpatient rehabilitation cost. Those with severe TBI had longer duration of inpatient rehabilitation that resulted in higher cost of inpatient rehabilitation. Presence of polytrauma, medical complications, post-traumatic amnesia and TBI post-non-accidental injury (NAI) were associated with higher cost of inpatient rehabilitation. CONCLUSION: The cost of inpatient rehabilitation for paediatric patients post-TBI is significant in Singapore. Patients with TBI secondary to NAI had significantly higher cost of inpatient rehabilitation. Ways to reduce duration of hospitalisation post-TBI and early step-down care or outpatient rehabilitation should be explored to reduce cost.

Resource implications of the latent tuberculosis cascade of care: a time and motion study in five countries.

BACKGROUND: The End TB Strategy calls for global scale-up of preventive treatment for latent tuberculosis infection (LTBI), but little information is available about the associated human resource requirements. Our study aimed to quantify the healthcare worker (HCW) time needed to perform the tasks associated with each step along the LTBI cascade of care for household contacts of TB patients. METHODS: We conducted a time and motion (TAM) study between January 2018 and March 2019, in which consenting HCWs were observed throughout a typical workday. The precise time spent was recorded in pre-specified categories of work activities for each step along the cascade. A linear mixed model was fit to estimate the time at each step. RESULTS: A total of 173 HCWs in Benin, Canada, Ghana, Indonesia, and Vietnam participated. The greatest amount of time was spent for the medical evaluation (median: 11 min; IQR: 6-16), while the least time was spent on reading a tuberculin skin test (TST) (median: 4 min; IQR: 2-9). The greatest variability was seen in the time spent for each medical evaluation, while TST placement and reading showed the least variability. The total time required to complete all steps along the LTBI cascade, from identification of household contacts (HHC) through to treatment initiation ranged from 1.8 h per index TB patient in Vietnam to 5.2 h in Ghana. CONCLUSIONS: Our findings suggest that the time requirements are very modest to perform each step in the latent TB cascade of care, but to achieve full identification and management of all household contacts will require additional human resources in many settings.

Petawatt Laser Guiding and Electron Beam Acceleration to 8 GeV in a Laser-Heated Capillary Discharge Waveguide.

Guiding of relativistically intense laser pulses with peak power of 0.85 PW over 15 diffraction lengths was demonstrated by increasing the focusing strength of a capillary discharge waveguide using laser inverse bremsstrahlung heating. This allowed for the production of electron beams with quasimonoenergetic peaks up to 7.8 GeV, double the energy that was previously demonstrated. Charge was 5 pC at 7.8 GeV and up to 62 pC in 6 GeV peaks, and typical beam divergence was 0.2 mrad.

Application of peripherally inserted central catheter in acute myeloid leukaemia patients undergoing induction chemotherapy.

Increasingly, peripherally inserted central catheters (PICC) are applied in patients with haematological malignancies. The feasibility and safety of PICC for induction chemotherapy in acute myeloid leukaemia (AML) remain unclear. Medical records of 89 newly diagnosed adult de novo AML patients, who achieved complete remission, were retrospectively reviewed (PICC group, n = 43; intravenous [IV] line group, n = 46). Patients' clinical characteristics and the number of blind punctures for blood sampling were compared between these two groups, and risk factors associated with bacteraemia were identified by univariate analysis. Patients in the PICC group experienced significantly fewer blind punctures than those in the IV line group (3.3 ± 3.6 vs. 14.4 ± 6.0; p = .000); 20.9% of PICC patients had bacteraemia, compared with 23.9% in the IV line group (p = .803). Most patients (76.7%) removed their PICC because treatment was completed. PICC increased the quality of life in AML patients undergoing chemotherapy induction by reducing the number of blind blood punctures required. Bacteraemia in PICC patients was comparable to that in IV line patients. PICC is, therefore, a feasible and safe central venous device for use in AML patients.

Peritherapeutic Hemodynamic Changes of Carotid Stenting Evaluated with Quantitative DSA in Patients with Carotid Stenosis.

BACKGROUND AND PURPOSE: Quantitative data from DSA have become important tools for understanding hemodynamic changes of intracranial lesions. In this study, we evaluated 8 hemodynamic parameters in patients before and after carotid artery angioplasty. MATERIALS AND METHODS: DSA images of 34 patients with carotid stenosis who underwent angioplasty and stent placement were retrospectively analyzed. Eleven ROIs (M1, M2, A1, A2, the parietal vein, superior sagittal sinus, internal jugular vein, and 4 in the ICA) were selected on color-coded DSA. Eight hemodynamic parameters (bolus arrival time, TTP, relative TTP, full width at half maximum, wash-in slope, washout slope, maximum enhancement, and area under the curve) were measured from the time-concentration curves of these ROIs. The dependent t test for paired samples was applied to these parameters before and after stent placement. RESULTS: We found that the treatment significantly reduced TTP, relative TTP, bolus arrival time, and washout slope at all arterial ROIs and full width at half maximum and area under the curve at some arterial ROIs. Bolus arrival time was significantly reduced after treatment for all arterial ROIs, the parietal vein, and the superior sagittal sinus. The maximum enhancement and wash-in slope did not show significant changes after treatment. After treatment, the relative TTP from the ICA to M1, M2, and the parietal vein returned to normal values. CONCLUSIONS: In addition to TTP and relative TTP, other parameters can be used to evaluate peritherapeutic cerebral hemodynamic changes. Bolus arrival time has the potential to evaluate brain circulation at arterial and venous sites, especially when TTP cannot be measured because of an incomplete time-concentration curve.

A home-based training programme improves family caregivers' oral care practices with stroke survivors: a randomized controlled trial.

OBJECTIVES: Stroke survivors experience poor oral health when discharged from the hospital to the community. The aim of this study was to evaluate the effectiveness of a home-based oral care training programme on knowledge, attitude, self-efficacy and practice behaviour of family caregivers. METHODS: A randomized controlled trial was conducted. The experimental group consisted of 48 family caregivers who received the home-based oral care training programme, and the control group consisted of 46 family caregivers who received routine oral care education. The outcomes were measured by the Knowledge of Oral Care, Attitude towards Oral Care, Self-Efficacy of Oral Care and Behaviour of Oral Care before the training programme, and at one and two months afterwards. The data were analysed using mixed model anova to determine differences in the outcomes between the two groups. RESULTS: The findings demonstrated that the intervention group had more knowledge (t = 8.80, P < 0. 001), greater self-efficacy (t = 3.53, P < 0.01) and better oral care behaviour (t = 11.93, P < 0.001) than the control group at one and two months, with statistically significant differences in oral care knowledge, self-efficacy and behaviour outcome over time. The attitude of the intervention group towards oral care practice was generally positive (mean of baseline and two month = 12.9 and 14.7), but no significant difference in attitude change between the control and intervention groups (t = 1.56, P = 0.12). The treatment interaction effect was significant for the family caregivers' behaviour of oral care at one and two months of the intervention for both groups. CONCLUSION: Our individualized home-based oral care education can achieve significant improvements in oral care knowledge and self-efficacy among family caregivers of stroke survivors, and it can sufficiently empower them to modify their oral care practices in a home-based healthcare environment.

Effect of family caregiver oral care training on stroke survivor oral and respiratory health in Taiwan: a randomised controlled trial.

OBJECTIVE: To evaluate the effectiveness of home-based oral care training programs on tongue coating (TC), dental plaque (DP), and symptoms of respiratory infection (SRI) in stroke survivors. METHODS: A single-blind, randomised, controlled trial conducted in a home-based setting over 2 months. Stroke survivors (n=48, experimental group) and their family caregivers received home-based oral care training programme while a control group of 46 stroke survivors and family caregivers received routine oral care education with swabs. TC, DP, and SRI were assessed at baseline and after one and two months, with results analysed using Mixed Model ANOVA. RESULTS: Poor oral hygiene and overall neglect of home oral care practices were observed at baseline. TC and DP scores were significantly reduced in the experimental group receiving the home-base oral care training program compared to the control group, who received only routine oral care education (P<0.001). The groupxtime interaction was significant, with decreased TC and DP scores for both groups at one month and at two months of additional care (when compared to baseline). The SRI scores were not significantly different between groups (P>0.05). The groupxtime interaction did not correlate with SRI for either group when compared to the baseline and to one month and two months of additional care. No adverse events were encountered and there was no external funding. CONCLUSIONS: Home-based oral care training programme had a beneficial effect on oral health as measured by TC and DP scores. The effect on SRI requires further longitudinal study.

Low efficacy of delthamethrin-treated net against Singapore Aedes aegypti is associated with kdr-type resistance.

There has been a worldwide surge in the number and severity of dengue in the past decades. In Singapore, relentless vector control efforts have been put in to control the disease since the 1960's. Space spraying, fogging, chemical treatment and source reduction are some commonly used methodologies for controlling its vectors, particularly Aedes aegypti. Here, as we explored the use of a commercially available delthamethrin-treated net as an alternative strategy and the efficacy of the treated net was found to be limited. Through bioassays and molecular studies, the failure of the treated net to render high mortality rate was found to be associated with the knockdown resistance (kdr) mutation. This is the first report of kdr- mutations in Singapore's Ae. aegypti. At least one point mutation, either homozygous or heterozygous, at amino acid residue V1016G of DIIS6 or F1269C of DIIIS6 was detected in 93% of field strains of Ae. aegypti. Various permutations of wild type and mutant amino acids of the four alleles were found to result in varying degree of survival rate among local field Ae. aegypti when exposed to the deltamethrin treated net. Together with the association of higher survival rate with the presence of both V1016G and F1269C, the data suggest the role of these mutations in the resistance to the deltamethrin. The high prevalence of these mutations were confirmed in a country wide survey where 70% and 72% of the 201 Ae. aegypti analysed possessed the mutations at residues 1016 and 1269 respectively. The highest mutated frequency combination was found to be heterozygous alleles (VG/FC) at both residues 1016 and 1269 (37.8%), followed by homozygous mutation at allele 1269 (24.4%) and homozygous mutation at allele 1016 (22.9%). The kdr- type of resistance among the vector is likely to undermine the effectiveness of pyrethroids treated materials against these mosquitoes.

Low efficacy of delthamethrin-treated net against Singapore Aedes aegypti is associated with kdr-type resistance

There has been a worldwide surge in the number and severity of dengue in the past decades. In Singapore, relentless vector control efforts have been put in to control the disease since the 1960’s. Space spraying, fogging, chemical treatment and source reduction are some commonly used methodologies for controlling its vectors, particularly Aedes aegypti. Here, as we explored the use of a commercially available delthamethrin-treated net as an alternative strategy and the efficacy of the treated net was found to be limited. Through bioassays and molecular studies, the failure of the treated net to render high mortality rate was found to be associated with the knockdown resistance (kdr) mutation. This is the first report of kdr- mutations in Singapore’s Ae. aegypti. At least one point mutation, either homozygous or heterozygous, at amino acid residue V1016G of DIIS6 or F1269C of DIIIS6 was detected in 93% of field strains of Ae. aegypti. Various permutations of wild type and mutant amino acids of the four alleles were found to result in varying degree of survival rate among local field Ae. aegypti when exposed to the deltamethrin treated net. Together with the association of higher survival rate with the presence of both V1016G and F1269C, the data suggest the role of these mutations in the resistance to the deltamethrin. The high prevalence of these mutations were confirmed in a country wide survey where 70% and 72% of the 201 Ae. aegypti analysed possessed the mutations at residues 1016 and 1269 respectively. The highest mutated frequency combination was found to be heterozygous alleles (VG/FC) at both residues 1016 and 1269 (37.8%), followed by homozygous mutation at allele 1269 (24.4%) and homozygous mutation at allele 1016 (22.9%). The kdr- type of resistance among the vector is likely to undermine the effectiveness of pyrethroids treated materials against these mosquitoes.

Decacationic [70]Fullerene Approach for Efficient Photokilling of Infectious Bacteria and Cancer Cells.

Photodynamic inactivation of pathogenic bacteria and cancer cells by novel water-soluble decacationic fullerene monoadducts, C60[>M(C3N6+C3)2] and C70[>M(C3N6+C3)2], were investigated. In the presence of a high number of electron-donating iodide anions as parts of quaternary ammonium salts in the arm region, we found that C70[>M(C3N6+C3)2] produced more highly reactive HO• radical than C60[>M(C3N6+C3)2], in addition to singlet oxygen (1O2). This finding offers an explanation of the preferential killing of Gram-positive and Gram-negative bacteria by C60[>M(C3N6+C3)2] and C70[>M(C3N6+C3)2], respectively. The hypothesis is that 1O2 can diffuse more easily into porous cell walls of Gram-positive bacteria to reach sensitive sites, while the less permeable Gram-negative bacterial cell wall needs the more reactive HO• to cause real damage.

Inducible cyclooxygenase expression mediating hypoxia/reoxygenation-induced pulmonary vasoconstriction is attenuated by a cyclooxygenase inhibitor in rats.

OBJECTIVE: Hypoxic pulmonary vasoconstriction (HPV) is a well known phenomenon to temporarily offset a ventilation-perfusion mismatch. Sustained HPV may lead to pulmonary hypertension. In this protocol, we studied the relationships between the HPV response and inducible cyclooxygenase II (COX II) activation after hypoxia-reoxygenation (H-R) challenge in an isolated perfused lung model. METHODS: An in situ isolated perfused rat lung model underwent inaction of hypoxia by ventilation with 5% CO(2)-95% N(2) for 10 minutes instead of 5% CO(2)-95% air; they were then reoxygenated with 5% CO(2)-95% air. We measured pulmonary arterial pressure (PAP) changes before, during, and after H-R challenge. We also estimated changes in blood concentrations of hydroxyl radicals, nitric oxide (NO) and thromboxane B(2) (TxB(2)) before and after H-R as well as mRNA expressions of COX II in lung tissue thereafter. A COX II inhibitor, celecoxib (10 mg/kg), was administered between 2 consecutive challenges. RESULTS: Hypoxia induced pulmonary vasoconstriction by increasing PAP (4.1 ± 0.8 mm Hg). Consecutive hypoxic challenges did not show tachyphylaxis (P > .05). H-R of lung tissues induced significant increases in blood concentrations of hydroxyl radicals (48.5 ± 7.6 vs 75.8 ± 11.5 mmol/L; P < .01), NO (54.3 ± 12.3 vs 77.7 ± 15.7 pmol; P < .05), and TxB(2) (42.3 ± 6.9 vs 58.7 ± 8.6 pg/mL; P < .05). Lung tissue H-R also significantly increased COX II mRNA expression compared with sham tissues (1 ± 0 vs 4.0 ± 2.8; P < .001). The COX II inhibitor celecoxib significantly attenuated HPV responses (P < .05) and attenuated the elevated blood concentrations of TxB(2) (P < .05), hydroxyl radicals (P < .01), nitric oxide (P < .05), and COX II mRNA expression (P < .05) after H-R challenge. CONCLUSIONS: Lung tissue H-R induced significant increases blood concentrations of inflammatory mediators and tissue mRNA expression of COX related to elevation of HPV responses. COX II inhibitor celecoxib attenuated the HPV responses by reducing TxB(2) release.

The protective effect of curcumin on ischemia-reperfusion-induced liver injury.

OBJECTIVE: Reperfusion of the ischemic liver results in the generation of oxidative and nitrosative stresses and reaction product of peroxynitrite, which induce rapid cytotoxicity and liver injury. In this study we demonstrated that curcumin, an antioxidant, attenuated ischemia/reperfusion (I/R)-induced liver injury. MATERIALS AND METHODS: Ischemia was induced by clamping the common hepatic artery and portal vein of rats for 30 minutes. Thereafter, flow was restored and the liver was reperfused for 80 minutes. Blood samples collected prior to ischemia and after reperfusion were analyzed for methyl guanidine (MG), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and adenosphate triphosphate (ATP). Blood levels of serum glutamic oxaloacetic transaminase (sGOT), serum glutamate pyruvate transaminase (sGPT), and lactic dehydrogenase (LDH), which served as indexes of liver injury, were measured. RESULTS: The protocol resulted in elevation of blood NO (P < .001), TNF-α (P < .001), and MG (P < .001). sGOT, sGPT, and LDH were elevated significantly (P < .001), whereas ATP was significantly diminished (P < .001). Pretreatment with curcumin (25 mg/kg) significantly attenuated the reperfusion liver injury, while the ATP content reversed. In addition, MG, TNF-α, and NO release were attenuated. CONCLUSIONS: These results indicated that curcumin exerted potent anti-inflammatory effects in I/R-induced liver injury due to its antioxidant effects.

Preparation of biologically active single-chain variable antibody fragments that target the HIV-1 gp120 V3 loop.

KD-247 is a humanized monoclonal antibody that targets the third hypervariable (V3) loop of gp120. It can efficiently neutralize a broad panel of clade B, but not non-clade B, HIV-1 isolates. To overcome this limitation, we are seeking to prepare genetically-engineered single-chain variable fragments (scFvs) of KD-247 that will have broader neutralizing activity against both clade B and non-clade B HIV-1 isolates. Initial attempts of optimizing the expression of KD-247 scFv have resulted in the formation of insoluble protein. Therefore, we have established purification protocols to recover, purify, and refold the KD-247 scFv from inclusion bodies. The protocol involved step-wise refolding of denatured scFv by dilution, dialysis, and on-column nickel-affinity purification. Monomeric scFv was further purified by size-exclusion chromatography. Using far UV circular dichroism (CD) spectroscopy we confirmed the expected beta-sheet profile of the refolded KD-247 scFv. Importantly, the refolded KD-247 scFv showed neutralizing activity against replication-competent HIV-1 BaL and JR-FL Env pseudotyped HIV-1, at potency comparable to that of the native full-size KD-247 antibody. Ongoing studies focus on the application of this system in generating KD-247 scFv variants with the ability to neutralize clade B and non-clade B HIV-1 isolates.

Development of immunity against hepatitis B virus after donor lymphocyte infusion in a peripheral blood stem cell transplantation recipient with chronic hepatitis B.

Hepatitis B virus (HBV) infection is one of the main concerns in blood and marrow transplantation (BMT) patients for possible breakthrough hepatitis. Active recipient immunization against HBV was found to be ineffective and many studies had showed that the adoptive transfer of immunity against hepatitis B virus would be possible by BMT with unknown duration and mechanism. A 46-year-old female patient with chronic hepatitis B had persistent detectable HBV DNA and positive serum hepatitis B e antigen (HBeAg), even while on long-term lamivudine and adefovir therapy. She received allogeneic matched unrelated donor peripheral blood stem cell transplantation (allo-MUD-PBSCT) for her refractory acute myeloid leukemia (AML). The HBV DNA became undetectable and she developed HBeAg seroconversion after PBSCT. Her hepatitis B surface antigen (HBsAg) remained positive, which disappeared later, along with the development of antibody to HBsAg after one shot of donor lymphocyte infusion (DLI) as a boost against her AML. In summary, BMT from an immunized donor would probably bring adoptive immunity against HBV. This adoptive immunity might be further enhanced by the subsequent DLI.

Persistent sterile pyuria in children? Don't forget tuberculosis!

Genitourinary tuberculosis (GUTB) is exceptionally uncommon among the local paediatric population. A 10-year-old Chinese girl with no risk factors for tuberculosis presented with recurrent sterile pyuria. Despite extensive renal investigations, no apparent cause could be ascertained for her obstructed left drainage system. The diagnosis was eventually confirmed with urine acid-fast bacilli culture, after a computed tomography scan suggested possible renal tuberculosis. Left nephroureterectomy had to be performed owing to deteriorating left kidney function. This report discusses the importance of considering tuberculosis when assessing a local paediatric patient with an atypical urinary tract infection. Early diagnosis of renal tuberculosis can prevent the sequelae of GUTB, including renal impairment.

Cyclosporine, an immunosuppressant, attenuates phorbol-induced lung injury in rats.

OBJECTIVE: White cell activation in the lung plays a critical role to induce lung injury and lymphocytes in the thoracic duct system may also participate. We evaluated the effect of cyclosporine on phorbol myristate acetate (PMA)-induced lung injury. MATERIALS AND METHODS: We used an in situ isolated, blood perfused rat lung model to measure pulmonary arterial pressure (PAP) and lung weight gain (LWG; g) for 50 minutes after a bolus injection of PMA (0.05 microg/mL). Oxygen radical release was estimated by an LKB 1251 luminometer and by nitric oxide (NO) release as measured by an ENO-20 NO analyzer. RESULTS: In the group exposed to PMA alone, the mean PAP increased from 16.53 +/- 1.28 to 43.33 +/- 3.40 mm Hg (P < .001), and lung weight increased by 4.35 +/- 0.67 g during the 50-minute perfusion after PMA challenge (P < .001). In vitro measurement showed that PMA induced a significant increase in oxygen radical release (P < .001). PMA attenuated NO release (P < .001) into the perfusion system. Pretreatment with cyclosporine (3 mg/kg) for 3 days prevented the increases in both PAP (P < .01) and LWG (P < .001). NO release was maintained in cyclosporine-pretreated rats. Cyclosporine also showed dose-dependent attenuation of oxygen radical release by PMA-activated white blood cells. CONCLUSION: The mechanisms responsible for the protective effect of cyclosporine on the lung injury induced by phorbol may be related to an attenuation of oxygen radical production with maintenance of NO release.

Apoptosis-dependent and -independent mechanisms mediate the phagocytic recognition/clearance of the HL60-A1 transfectants with prolonged survival.

OBJECTIVE: The phagocytic recognition and clearance of the recruited inflammatory cells with prolonged survival play a pivotal role in relieving tissue inflammation and maintaining tissue homeostasis. Transgenic mice expressing Bcl-2 in mature neutrophils demonstrated that Bcl-2 attenuated neutrophil apoptosis, while the homeostasis of the neutrophil population was essentially unaffected. This result suggests that clearance of neutrophils with prolonged survival operates independently from apoptosis. Owing to the constitutive and inducible expression of Bcl-2 homologue, A1 in human neutrophils and the intolerance of preparation for the isolated human neutrophils with prolonged survival, the human promyelocytic HL60-A1 transfectants were established to study the mechanism of phagocytic recognition/clearance of the cells with prolonged survival. MATERIALS AND METHODS: The non-apoptotic cells with prolonged survival were enriched by serum withdrawal for five days and negatively isolated by annexin V-binding beads. Then, the cells were labeled with a fluorogenic marker. Monocyte-derived macrophages (MDM) were co-cultured to perform the phagocytosis assay, and flow cytometry was employed to determine the phagocytic index. RESULTS: In the serum-free condition, the phagocytic index of HL60-A1 transfectants was little different from that of the HL60-EGFP control, despite showing a significantly lower degree of apoptosis. While the phagocytic index of HL60-EGFP control was significantly correlated with the degree of apoptosis, the index of the HL60-A1 transfectants was less relevant to it. The phagocytic index for the annexin V-positive cells did not distinguish the two cell types. However, the phagocytic index for the annexin V-negative cells from the HL60-A1 transfectants was increased with age in days. Preincubation of MDM with the scavenger receptor inhibitor, Oxi-LDL, and the inhibitory antibodies against alphavbeta3, CD14 and CD36 surface molecules could attenuate the phagocytic recognition of the annexin V-positive HL60 cells but not the annexin V-negative A1 transfectants with prolonged survival. CONCLUSIONS: This study thus suggests that a mechanism unrelated to apoptosis exists, which mediates the phagocytic clearance of the non-apoptotic cells with prolonged survival and may be associated with A1 function in the myeloid cells.

Modulation of dendritic cells by endurance training.

A periodized endurance training is able to adapt physical and psychological needs and increase exercise performance. Dendritic cells (DCs) play a key role in regulation of the immune response. In the present study, we trained Sprague-Dawley (SD) rats for five weeks using a progressive endurance protocol with the aim of measuring the effect on myeloid DC differentiation and maturation. Rats were divided into a non-exercise group (NEG) and an exercise group (EG). Bone marrow cells were isolated from these rats after training and cultured in the presence of granulocyte/monocyte-colony stimulatory factor (GM-CSF) and interleukin (IL)-4, and the resultant immature DCs were triggered with lipopolysaccharide to mature. DCs were collected and the main characteristics of DCs were assessed. The recovery rate and the expression of major histocompatibility complex (MHC) class II molecules for DC collected from EG was markedly greater than NEG. The function of DCs from EG to trigger a mixed leukocyte reaction and IL-12 production was higher than NEG. There was no liver and renal toxicity observed in all rats. Changes in food/water consumption and body weight increase between the groups were normal for the conditions. This study demonstrated that periodized endurance training is able to modulate DC development and shift them towards a more mature state.