Silymarin enriched gelatin methacrylamide bioink imparts hepatoprotectivity to 3D bioprinted liver construct against carbon tetrachloride induced toxicity.

Three-dimensional liver bioprinting is an emerging technology in the field of regenerative medicine that aids in the creation of functional tissue constructs that can be used as transplantable organ substitutes. During transplantation, the bioprinted donor liver must be protected from the oxidative stress environment created by various factors during the transplantation procedure, as well as from drug-induced damage from medications taken as part of the post-surgery medication regimen following the procedure. In this study, Silymarin, a flavonoid with the hepatoprotective properties were introduced into the GelMA bioink formulation to protect the bioprinted liver against hepatotoxicity. The concentration of silymarin to be added in GelMA was optimised, bioink properties were evaluated, and HepG2 cells were used to bioprint liver tissue. Carbon tetrachloride (CCl4) was used to induce hepatotoxicity in bioprinted liver, and the effect of this chemical on the metabolic activities of HepG2 cells was studied. The results showed that Silymarin helps with albumin synthesis and shields liver tissue from the damaging effects of CCl4. According to gene expression analysis, CCl4 treatment increased TNF-α and the antioxidant enzyme SOD expression in HepG2 cells while the presence of silymarin protected the bioprinted construct from CCl4-induced damage. Thus, the outcomes demonstrate that the addition of silymarin in GelMA formulation protects liver function in toxic environments.

OTP-Q encryption and Diffie-Hellman mutual authentication for e-healthcare data based on lightweight S-WBSN framework.

BACKGROUND: Protection of wireless technology-enabled e-healthcare data transfer over constrained devices of body sensor networks using lightweight security mechanisms is the demand of health sector nowadays. OBJECTIVE: A new secure wireless body sensor network architecture (S-WBSN) with reduced CPU cycles and computational cost is proposed. S-WBSN uses OTP-Q (One-Time Pad-Quasi) and Diffie-Hellman key exchange algorithms for encryption and mutual authentication, respectively. METHODS: To ensure mutual authentication among and components, the Diffie-Hellman key exchange algorithm is used. Using the S-WBSN architecture, security requirements such as mutual authentication, and privacy preservation thwarting security attacks are perfectly met comparing other security-based research works on healthcare data monitoring. RESULTS: The one-time pad-based quasi-group algorithm is a stream block cipher that operates on the data observed from the sensors of the WBSN. Before transmitting encrypted data, authentication is to be established. CONCLUSION: The proposed system methodology proves to be efficient and consumes fewer CPU cycles. The encryption and decryption processing times are comparatively less than the state-of-the-art approaches.

Differential sensitivity of cytotoxic T lymphocytes and lymphokine-activated killer cells to inhibition by L-ornithine.

The selective inhibition of murine cytotoxic T lymphocyte (CTL) differentiation in C57B1/6 (B6) anti-DBA/2 mixed leukocyte cultures (MLC) by the amino acid L-ornithine (Orn) could not be reversed by addition of up to 1000 U/ml IL-2. Analysis of the effects of Orn on induction of lymphokine-activated killer (LAK cells), using dosages of IL-2 from 10-1000 U/ml and measuring cytolytic activity against two tumor targets (P815 and YAC-1) over the course of 5 days, indicated that LAK cells were not suppressed by Orn. LAK precursors and effector cells were CD8- and ASGM1+, indicating that they were derived from natural killer (NK) cells. We also found that the growth and maintenance of cloned CTL lines were not sensitive to inhibition by Orn; nor was their acquisition of nonspecific cytolytic activity in the presence of high lymphokine concentrations. Thus, induction of naive CTL shows differential susceptibility to Orn inhibition relative to LAK and LAK-like activities by NK and cloned CTL lines in response to IL-2.

Difluoromethylornithine (DFMO) arrests murine CTL development in the late, pre-effector stage.

DL-alpha-Difluoromethylornithine (DFMO) is a specific inhibitor of the rate-limiting enzyme in polyamine biosynthesis, ornithine decarboxylase (ODC). DFMO (1 mM) added to C57BL/6 anti-DBA/2 murine mixed lymphocyte cultures (MLC) inhibited cytolytic T lymphocyte (CTL) activity on days 3 and 5 by 88% and 96%. Putrescine (PUT; 1 mM) and spermidine (SPD; 0.01 mM) reversed DFMO inhibition, indicating that DFMO inhibition was caused by ODC antagonism. T helper (Th) cell and accessory cell functions were not affected since DFMO did not inhibit MLC proliferation or lymphokine production. Furthermore, exogenous IL-1, IL-2, IL-4, interferon-gamma, or a rat Con A supernatant failed to abrogate DFMO inhibition. Inhibition was reversible within 48 h of removing cells from DFMO; moreover, subsequent development of DFMO-blocked CTL did not require CD4+ cells. Clonal expansion of CTL treated with 1 mM DFMO for three days in MLC, determined by subsequent analysis in limiting dilution microcultures, was only approx. 1 cell division less than control. These results indicate DFMO inhibition is exerted directly on the CTL, and that the process of differentiation was more affected by a reduction in polyamine biosynthesis than proliferation. This may be a useful model to the study stages and events of CTL development, and the roles played by polyamines in supporting these processes.

Laryngo-tracheo-bronchial foreign bodies in children.

Inhalation of a foreign body into the respiratory passage can be a serious and sometimes fatal childhood accident. In this paper we analyse the management of 223 children with laryngo-tracheo-bronchial foreign bodies. Children below three years of age were found to be the most vulnerable. The majority of the patients were boys. Over a quarter of the patients did not present with a history of inhalation. Only 52 per cent reported within 24 hours of inhalation. Endoscopic removal was possible in all but nine cases. One hundred and forty eight (66.4 per cent) of the recovered foreign bodies were organic in origin, the majority of them being peanuts. In one hundred and five (47.1 per cent) the objects found their way into the right bronchial tree. There were two deaths. The modalities of diagnosis and management are discussed.