The changes in biomechanics of rat thoracic aorta at different post mortem interval (PMI) (0-7 d) were observed when it was stretched in one direction. Some significant changes were disclosed by statistical analyses. Maximum stretch, maximum strain and maximum energy showed a significant relationship with PMI, the coefficients of determination being 0.822, 0.716 and 0.669 respectively, P < 0.001. The stretch experiment of thoracic aorta may be a novel method to determine PMI.
Animals ; Aorta, Thoracic ; pathology ; Biomechanical Phenomena ; Male ; Postmortem Changes ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Stress, Mechanical ; Time Factors

OBJECTIVETo explore the immune response of silicotic rats to sheep red blood cells(SRBC).

METHODSSilicotic rats were immunized with SRBC by tracheal instillation(Group 1) or intraperitoneal injection (Group 2), and non-silicotic rats were immunized by tracheal instillation as normal control(Group 3). The levels of serum hemolytic index(HC50) were measured on 7, 12, 20, 25, and 32 days after primary immunization and 5, 12, 15 days after the second immunization. Special anti-SRBC IgG was measured with ELISA(A490 nm) on 12, 20, 25, 32 days and 5, 12, 15, 27 days respectively. Delayed-type hypersensitivity(DTH) to SRBC was measured 20 days after second immunization and DTH reaction was determined at 24, 48, 72, and 96 h after administration. Total cell count and cell populations in the bronchoalveolar lavage fluid(BALF), lung associated lymph node(LALN) and spleen weight, special IgG secreted from spleen cells were measured at the end of the experiment.

RESULTSThe HC50 of Group 1(47.4 +/- 1.0, 52.2 +/- 4.6, 31.1 +/- 11.9, 43.8 +/- 3.5, 33.6 +/- 16.8, 49.0 +/- 2.3, 92.9 +/- 20.2, 87.7 +/- 5.2) were statistically higher than those of Group 3(40.4 +/- 10.6, 2.8 +/- 2.5, 0.8 +/- 0.6, 6.6 +/- 5.8, 1.4 +/- 0.1, 36.5 +/- 16.5, 53.0 +/- 33.2, 2.6 +/- 2.2). The special anti-SRBC IgG response in Group 1(1.67 +/- 0.19, 1.98 +/- 0.36, 1.12 +/- 0.50, 1.38 +/- 0.30, 2.75 +/- 0.15, 2.60 +/- 0.28, 2.86 +/- 0.10, 2.50 +/- 0.20) were much stronger than those in Group 3 (0.59 +/- 0.30, 0.56 +/- 0.21, 0.21 +/- 0.16, 0.22 +/- 0.01, 0.81 +/- 0.25, 0.74 +/- 0.25, 0.69 +/- 0.26, 1.38 +/- 0.41). Furthermore, the results of DTH showed positive response and the ratios for diameter of skin rash > 5 mm at 24, 48, 72, 96 h were 16/16, 16/16, 16/16, 15/16 respectively in Group 1, while those in Group 3 were 8/15, 1/15, 1/15, 1/15 respectively. Total cell count in the BALF, LALN and spleen weight, and special IgG secreted from spleen cells in Group 1 were higher too. Group 2 expressed almost of the same but with mild immunologic responses as Group 1.

CONCLUSIONSilicosis-induced extremely strong DTH and over-response of humoral immunity to some antigens may contribute to the likelihood of silicosis complicated with tuberculosis.

Animals ; Erythrocytes ; immunology ; Hypersensitivity, Delayed ; etiology ; Immunization ; Immunoglobulin G ; blood ; Rats ; Sheep ; Silicosis ; immunology

Objective To investigate the efficacy and safety of artificial liver support therapy with an Evanure-4A selective membrane plasma separator and its influence on platelet count in the treatment of patients with acute-on-chronic liver failure(ACLF)patients with different platelet counts.Methods A total of 302 patients with ACLF who were hospitalized in Department of Hepatology,Chengdu Public Health Clinical Medical Center,from January 2021 to May 2023,were enrolled,and according to the platelet count(PLT),they were divided into group A(25×109/L—50×109/L)with 101 patients,group B(51×109/L—80×109/L)with 98 patients,and group C(81×109/L—100×109/L)with 103 patients.In addition to medical treatment,all patients received different modes of artificial liver support therapy based on their conditions,including plasma perfusion combined with plasma exchange,double plasma molecular adsorption combined with plasma exchange,and bilirubin system adsorption combined with plasma exchange.The paired t-test was used for comparison of continuous data before and after treatment in each group;an analysis of variance was used for comparison between multiple groups,and the SNK-q test was used for further comparison between two groups;the chi-square test was used for comparison of categorical data between multiple groups.Results Of all 302 patients,268(88.74%)achieved varying degrees of improvement in clinical symptoms after artificial liver support therapy.After treatment,all three groups had varying degrees of reductions in alanine aminotransferase(t=14.755,21.614,and 15.965,all P＜0.001),aspartate aminotransferase(t=11.491,19.301,and 13.919,all P＜0.001),total bilirubin(t=19.182,17.486,and 21.75,all P＜0.001),and international normalized ratio(INR)(t=3.497,3.327,and 4.358,all P＜0.05).After artificial liver support therapy with an Evanure-4A selective membrane plasma separator,PLT in group A decreased from(37.73±6.27)×109/L before treatment to(36.59±7.96)×109/L after treatment,PLT in group B decreased from(66.97±7.64)×109/L before treatment to(62.59±7.37)×109/L after treatment,and PLT in group C decreased from(93.82±5.38)×109/L before treatment to(85.99±12.49)×109/L after treatment;groups B and C had significant reductions in PLT after treatment(t=12.993 and 8.240,both P＜0.001),but there was no significant difference in group A(P＞0.05).There was no significant difference in the incidence rate of adverse reactions during artificial liver support therapy between the three groups(P＞0.05).Conclusion Artificial liver support therapy can improve liver function and INR in patients with ACLF.The use of Evaure-4A selective membrane plasma separator during artificial liver support therapy has little influence on platelets,and it is safe in the treatment of ACLF patients with a significantly lower level of platelets.

Aging-elevated DNMT3A R882H-driven clonal hematopoiesis (CH) is a risk factor for myeloid malignancies remission and overall survival. Although some studies were conducted to investigate this phenomenon, the exact mechanism is still under debate. In this study, we observed that DNMT3A R878H bone marrow cells (human allele: DNMT3A R882H) displayed enhanced reconstitution capacity in aged bone marrow milieu and upon inflammatory insult. DNMT3A R878H protects hematopoietic stem and progenitor cells from the damage induced by chronic inflammation, especially TNFα insults. Mechanistically, we identified that RIPK1-RIPK3-MLKL-mediated necroptosis signaling was compromised in R878H cells in response to proliferation stress and TNFα insults. Briefly, we elucidated the molecular mechanism driving DNMT3A R878H-based clonal hematopoiesis, which raises clinical value for treating DNMT3A R882H-driven clonal hematopoiesis and myeloid malignancies with aging.