Specific Inhibition of Histone Deacetylase 8 Reduces Gene Expression and Production of Proinflammatory Cytokines in Vitro and in Vivo

ITF2357 (generic givinostat) is an orally active, hydroxamic-containing histone deacetylase (HDAC) inhibitor with broad anti-inflammatory properties, which has been used to treat children with systemic juvenile idiopathic arthritis. ITF2357 inhibits both Class I and II HDACs and reduces caspase-1 activity in human peripheral blood mononuclear cells and the secretion of IL-1β and other cytokines at 25–100 nm; at concentrations >200 nm, ITF2357 is toxic in vitro. ITF3056, an analog of ITF2357, inhibits only HDAC8 (IC₅₀ of 285 nm). Here we compared the production of IL-1β, IL-1α, TNFα, and IL-6 by ITF2357 with that of ITF3056 in peripheral blood mononuclear cells stimulated with lipopolysaccharide (LPS), heat-killed Candida albicans, or anti-CD3/anti-CD28 antibodies. ITF3056 reduced LPS-induced cytokines from 100 to 1000 nm; at 1000 nm, the secretion of IL-1β was reduced by 76%, secretion of TNFα was reduced by 88%, and secretion of IL-6 was reduced by 61%. The intracellular levels of IL-1α were 30% lower. There was no evidence of cell toxicity at ITF3056 concentrations of 100–1000 nm. Gene expression of TNFα was markedly reduced (80%), whereas IL-6 gene expression was 40% lower. Although anti-CD3/28 and Candida stimulation of IL-1β and TNFα was modestly reduced, IFNγ production was 75% lower. Mechanistically, ITF3056 reduced the secretion of processed IL-1β independent of inhibition of caspase-1 activity; however, synthesis of the IL-1β precursor was reduced by 40% without significant decrease in IL-1β mRNA levels. In mice, ITF3056 reduced LPS-induced serum TNFα by 85% and reduced IL-1β by 88%. These data suggest that specific inhibition of HDAC8 results in reduced inflammation without cell toxicity.     

The Prevalence of unexpected antibodies in Saudi's plasma prior blood transfusion and their association with clinical conditions: A cross-sectional study

Unexpected antibodies, also called irregular antibodies, are not known to exist in a person's serum before testing. This research aims to assess the prevalence of unexpected antibodies and their correlation with several clinical conditions. This cross-sectional prospective study, undertaken from June 2019 to June 2020, included ABO, Rh grouping, cross-matching, and antibody screening. Antibody identification was performed only on patients who tested positive in the screening test. From a total of 9764 participants who were screened for unexpected antibodies, 107 (1.1%) tested positive. The Rh blood group system antibodies were the most frequent, particularly anti-D. There was also a significant correlation between the unexpected antibodies and history of transfusion, pregnancy, and autoimmune diseases as P ≤ 0.05. The most prominent unexpected antibodies in the study belong to the Rh system (Anti-D). Moreover, as a result of the strong correlation between the unexpected antibodies as well as the history of transfusion, pregnancy, and autoimmune diseases, the highest safety criteria must be followed during the transfusion of blood to patients with these clinical conditions.     

Cofactor Activity in Factor VIIIa of the Blood Clotting Pathway Is Stabilized by an Interdomain Bond between His281 and Ser524 Formed in Factor VIII

The factor VIII (FVIII) crystal structure suggests a possible bonding interaction of His²⁸¹ (A1 domain) with Ser⁵²⁴ (A2 domain), although the resolution of the structure (∼4 Å) does not firmly establish this bonding. To establish that side chains of these residues participate in an interdomain bond, we prepared and examined the functional properties of a residue swap variant (H281S/S524H) where His²⁸¹ and Ser⁵²⁴ residues were exchanged with one another and a disulfide-bridged variant (H281C/S524C) where the two residues were replaced with Cys. The latter variant showed efficient disulfide bonding of the A1 and A2 domains. The swap variant showed WT-like FVIII and FVIIIa stability, which were markedly reduced for H281A and S524A variants in an earlier study. The disulfide-bridged variant showed ∼20% increased FVIII stability, and FVIIIa did not decay during the time course measured. This variant also yielded 35% increased thrombin peak values compared with WT in a plasma-based thrombin generation assay. Binding analyses of H281S-A1/A3C1C2 dimer with S524H-A2 subunit yielded a near WT-like affinity value, whereas combining the variant dimer or A2 subunit with the WT complement yielded ∼5- and ∼10-fold reductions, respectively, in affinity. Other functional properties including thrombin generation potential, FIXa binding affinity, K_m for FX of FXase complexes, thrombin activation efficiency, and down-regulation by activated protein C showed similar results for the two variants compared with WT FVIII. These results indicate that the side chains of His²⁸¹ and Ser⁵²⁴ are in close proximity and contribute to a bonding interaction in FVIII that is retained in FVIIIa.     

Computational simulations of flow dynamics and blood damage through a bileaflet mechanical heart valve scaled to pediatric size and flow

Despite pressing needs, there are currently no FDA approved prosthetic valves available for use in the pediatric population. This study is performed for predictive assessment of blood damage in bileaflet mechanical heart valves (BMHVs) with pediatric sizing and flow conditions. A model of an adult-sized 23 mm St. Jude Medical (SJM) Regent^™ valve is selected for use in simulations, which is scaled in size for a 5-year old child and 6-month old infant. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow with thousands of suspended platelets for cases of adult, child, and infant BMHV flows. Adult BMHV flows demonstrate more disorganized small-scale flow features, but pediatric flows are associated with higher fluid shear stresses. Platelet damage in the pediatric cases is higher than in adult flow, highlighting thrombus complication dangers of pediatric BMHV flows. This does not necessarily suggest clinically important differences in thromboembolic potential. Highly damaged platelets in pediatric flows are primarily found far downstream of the valve, as there is less flow recirculation in pediatric flows. In addition, damage levels are well below expected thresholds for platelet activation. The extent of differences here documented between the pediatric and adult cases is of concern, demanding particular attention when pediatric valves are designed and manufactured. However, the differences between the pediatric and adult cases are not such that development of pediatric sized valves is untenable. This study may push for eventual approval of prosthetic valves resized for the pediatric population. Further studies will be necessary to determine the validity and potential thrombotic and clinical implications of these findings.     

Extensive chromosome conservatism in Atlantic butterflyfishes,genus Chaetodon Linnaeus, 1758: Implications for the high hybridization success

Chaetodontidae is a family of marine butterflyfishes phylogenetically derived within the Perciformes, whose representatives are important members of coral reef ecosystems worldwide. Biological aspects of Chaetodontidae have been intensively studied, except for chromosomal analyses. Although previous reports indicate a conserved perciform-like karyotype in butterflyfishes, it remains unclear if this pattern extends to the chromosomal microstructure. New cytogenetic data are presented for two Chaetodontidae species (Chaetodon striatus and Chaetodon ocellatus) from the Western Atlantic, including karyotyping, C-banding, Ag-NOR, CMA₃/DAPI staining, and two-color-FISH for mapping of 18S and 5S ribosomal genes. All populations of both species shared a karyotype with 2n = 48 acrocentric chromosomes, with pericentromeric C-positive heterochromatin and 5S and 18S rDNA located in the same region on the long arms of pairs 10 and 21, respectively. The cytogenetic similarities within and between both Chaetodon species reinforce their remarkable stability also in the chromosome microstructure. Therefore, speciation in this genus was not followed by significant karyotypic changes. Both ecological and chromosomal properties, combined with recent diversification, might be responsible for the apparent karyotype stasis and high hybridization levels found in marine butterflyfishes.     

Blood meal sources of mosquitoes captured in municipal parks in São Paulo,Brazil

The aim of this study was to investigate blood meal sources of mosquitoes captured in municipal parks in the city of São Paulo, Brazil, and to identify possible associations between mosquito species and their food preferences. Fourteen species of blood hosts of 510 engorged adult female mosquitoes were identified using PCR assays with a vertebrate‐specific primer set based on cytochrome b mitochondrial DNA of the following vertebrates: birds, dogs, cats, rodents, humans, and other primates. Mosquitoes were captured using a manual aspirator, CDC traps in the canopy, CDC traps at ground level, and Shannon traps. With the exception of cats, all other vertebrates were used as hosts by mosquitoes in the parks. Statistical analysis failed to show any trend toward association between most culicid species captured and the sources of blood meals. Instead, they revealed random patterns, indicating that the mosquitoes fed on the most abundant or convenient blood meal sources. Although feeding preferences were observed in two species (birds in the case of Cx. nigripalpus and dogs in the case of Cx. quinquefasciatus), our results highlight the opportunistic feeding habits of the female mosquitoes in this study.     

先天性白内障大鼠血液生化及血液流变学分析

目的：测定先天性白内障大鼠血液常规、生化正常值及血液流变学变化。方法采用XS-800i血常规分析仪和OLYMPUS AV2700生化自动分析仪对185～211 g大鼠共计90只进行血液常规和生化检测及用SA-6600自动血流变测试仪对血液进行流变学的测定。结果血像检测结果是白内障与正常对照同性比较无差异显著性（P ＞0.05）;小眼白内障与正常对照同性比较红细胞宽度（RDW）间差异显著（P ＜0.01或 P ＜0.05）。血生化检测结果是白内障大鼠与正常对照组同性间比较白蛋白（ALB）差异显著（P ＜0.01或P ＜0.05）雌性与对照组比较尿素（Ure）差异显著（P ＜0.01）,小眼白内障雌性与正常对照比较肌酐（Cr）差异非常显著（P ＜0.01）。白内障、小眼白内障大鼠的红细胞是雄性的低于雌性（P ＜0.05,P ＜0.01）而血小板是雄性的高于雌性（P ＜0.01）,肌酐是雄性低于雌性P ＜0.01）,正常组雄雌间无差异;血液流变学各组间无差异显著性。结论白内障大鼠与正常组大鼠间某些血常规及生化指标有一定的差异,该数据为该鼠在这领域的使用提供参考。