Irreversible inhibition of estrogen receptor α signaling and the emergence of hormonal resistance in MCF7 breast cancer cells induced by DNA damage agents.

Combining chemotherapy and hormone therapy is a prevalent approach in breast cancer treatment. While the cytotoxic impact of numerous chemotherapy drugs stems from DNA damage, the exact role of these DNA alterations in modulating estrogen receptor α (ERα) machinery remains elusive. The present study aimed to analyze the impact of DNA damage agents on ERα signaling in breast cancer cells and assess the signaling pathways mediating the influence of DNA damage drugs on the ERα machinery. Cell viability was assessed using the MTT method, while the expression of signaling proteins was analyzed by immunoblotting. ERα activity in the cells treated with various drugs (17ß-estradiol, tamoxifen, 5-fluorouracil) was assessed through reporter gene assays. In vitro experiments were conducted on MCF7 breast cancer cells subjected to varying durations of 5-fluorouracil (5-FU) treatment. Two distinct cell responses to 5-FU were identified based on the duration of the treatment. A singular dose of 5-FU induces pronounced DNA fragmentation, temporally suppressing ERα signaling while concurrently activating AKT phosphorylation. This suppression reverses upon 5-FU withdrawal, restoring normalcy within ten days. However, chronic 5-FU treatment led to the emergence of 5-FU-resistant cells with irreversible alterations in ERα signaling, resulting in partial hormonal resistance. These changes mirror those observed in cells subjected to UV-induced DNA damage, underscoring the pivotal role of DNA damage in shaping estrogen signaling alterations in breast cancer cells. In summary, the results of the present study suggested that the administration of DNA damage agents to cancer cells can trigger irreversible suppression of estrogen signaling, fostering the development of partial hormonal resistance. This outcome may ultimately impede the efficacy of combined or subsequent chemo- and hormone therapy strategies.

Effect of gamma and Ultraviolet-C sterilization on BMP-7 level of indigenously prepared demineralized freeze-dried bone allograft.

The presence of bone morphogenetic proteins in demineralized freeze-dried bone allograft (DFDBA) are responsible for developing hard tissues in intraosseous defects. The most common mode of sterilization of bone allografts, i.e., Gamma rays, have dramatic effects on the structural and biological properties of DFDBA, leading to loss of BMPs. Ultraviolet-C radiation is a newer approach to sterilize biodegradable scaffolds, which is simple to use and ensures efficient sterilization. However, UV-C radiation has not yet been effectively studied to sterilize bone allografts. This study aimed to compare and evaluate the effectiveness of Gamma and Ultraviolet-C rays in sterilizing indigenously prepared DFDBA and assess their effect on the quantity of BMP-7 present in the allograft. DFDBA samples from non-irradiated, gamma irradiated, and UV-C irradiated groups were tested for BMP-7 level and samples sterilized with gamma and UV-C rays were analysed for sterility testing. The estimated mean BMP-7 level was highest in non-irradiated DFDBA samples, followed by UV-C irradiated, and the lowest in gamma irradiated samples. Our study concluded that UV-C rays effectively sterilized DFDBA as indicated by negative sterility test and comprised lesser degradation of BMP-7 than gamma irradiation.

A Review of the Efficacy of Ultraviolet C Irradiation for Decontamination of Pathogenic and Spoilage Microorganisms in Fruit Juices.

Ultraviolet C (UV-C, 200-280 nm) light has germicidal properties that inactivate a wide range of pathogenic and spoilage microorganisms. UV-C has been extensively studied as an alternative to thermal decontamination of fruit juices. Recent studies suggest that the efficacy of UV-C irradiation in reducing microorganisms in fruit juices is greatly dependent on the characteristics of the target microorganisms, juice matrices, and parameters of the UV-C treatment procedure, such as equipment and processing. Based on evidence from recent studies, this review describes how the characteristics of target microorganisms (e.g., type of microorganism/strain, acid adaptation, physiological states, single/composite inoculum, spore, etc.) and fruit juice matrices (e.g., UV absorbance, UV transmittance, turbidity, soluble solid content, pH, color, etc.) affect the efficacy of UV-C. We also discuss the influences on UV-C treatment efficacy of parameters, including UV-C light source, reactor conditions (e.g., continuous/batch, size, thickness, volume, diameter, outer case, configuration/arrangement), pumping/flow system conditions (e.g., sample flow rate and pattern, sample residence time, number of cycles), homogenization conditions (e.g., continuous flow/recirculation, stirring, mixing), and cleaning capability of the reactor. The collective facts indicate the immense potential of UV-C irradiation in the fruit juice industry. Existing drawbacks need to be addressed in future studies before the technique is applicable at the industrial scale.

Enhanced suppression effects on Microcystis aeruginosa by combining hydrogen peroxide and intermittent UVC irradiation: The importance of triggering advanced oxidation process within cells.

In order to strengthen the inhibitory effect of UVC/H2O2 on Microcystis aeruginosa growth, this study designed a novel strategy for inducing an advanced oxidation process in algal cells by splitting UVC irradiation into two rounds. The first irradiation of UVC upon adding H2O2 facilitated the delivery of H2O2 into the cell cytoplasm, which induced an intracellular advanced oxidation process after the second irradiation of UVC. The intermittent treatment of UVC/H2O2 could further attack the Ca-Mn and Fe-S clusters in the photosynthetic electron transport chain. In contrast, conventional simultaneous treatment of UVC/H2O2 only attacked the interaction subunits between PSII cores and the phycobilisome. The block of the photosynthetic electron transport chain, shedding of the Ca-Mn cluster, and damage of the Fe-S cluster gave rise to massive intracellular H2O2, O2•-, and HO•. Consequently, ROS acted as a mediator and led to caspase-3(-like) activation and the subsequent initiation of apoptosis-like cell death. The remarkable functional mechanisms make the intermittent treatment of UVC/H2O2 an ideal method for the practical application of suppressing HABs (target-selective, long-lasting, cost-minimized, and eco-friendly).

Bile Salt-Stimulated Lipase Activity in Donor Breast Milk Influenced by Pasteurization Techniques.

Breast milk contains bile salt-stimulated lipase (BSSL), which significantly increases the fat digestion capacity of newborns who have limited pancreatic lipase secretion in the first few months after birth. Problematically, Holder pasteurization used in non-profit milk banks to ensure the microbiological safety of donor milk for infants, particularly preterm infants (<37 weeks gestation age), destroys milk BSSL, thus limiting infant fat absorption capacity. Alternative strategies are needed to ensure the safety of donor milk while preserving BSSL activity. Three alternative pasteurization techniques-high-pressure processing (HPP, 550 MPa, 5 min), gamma cell irradiation (IR, 2.5 Mrads) and UV-C (254 nm, 0-33,000 J/L)-were compared with Holder pasteurization (low-temperature long-time, LTLT, 62.5°C, 30 min) for retention of BSSL activity in donor breast milk. As the time required for donor milk pasteurization by UV-C in published methods was not clear, donor breast milk was spiked with seven common bacterial strains and treated by UV-C for variable time periods and the minimum UV-C dosage required to achieve a 5-log10 reduction of CFU/mL was determined. Eight thousand two hundred fifty J/L of UV-C exposure was sufficient to achieve 5-log10 reduction of each of bacterial targets, including Bacillus and Paenibacillus spores. The retention of BSSL activity was highest after HPP (retaining 62% of the untreated milk BSSL activity), followed by UV-C (16,500 J/L), IR and LTLT (35, 29, and 0.3% retention, respectively). HPP was an effective alternative to pasteurize milk with improved retention of BSSL activity compared to Holder pasteurization. Future work should investigate the effect of alternative pasteurization techniques on the entire array of bioactive components in donor breast milk and how these changes affect preterm infant health outcomes. Implementation of HPP technique at milk banks could improve donor milk-fed infant fat absorption and growth.

Bioprocess: Robustness with Respect to Mycoplasma Species.

Capture bioprocessing unit operations were previously shown to clear or kill several log10 of a model mycoplasma Acholeplasma laidlawii in lab-scale spike/removal studies. Here, we confirm this observation with two additional mollicute species relevant to biotechnology products for human use: Mycoplasma orale and Mycoplasma arginini Clearance of M. orale and M. arginini from protein A column purification was similar to that seen with A. laidlawii, though some between cycle carryover was evident, especially for M. orale However, on-resin growth studies for all three species revealed that residual mycoplasma in a column slowly die off over time rather than expanding further. Solvent/detergent exposure completely inactivated M. arginini though detectable levels of M. orale remained. A small-scale model of a commercial low-pH hold step did inactivate live M. orale, but this inactivation required a lower pH set point and occurred with slower kinetics than previously seen with A. laidlawii Additionally, ultraviolet-C irradiation was shown to be effective for A. laidlawii and M. orale inactivation whereas virus-retentive filters for upstream and downstream processes, as expected, cleared A. laidlawii These data argue that M. orale and M. arginini overall would be largely cleared by early bioprocessing steps as shown previously for A. laidlawii, and that barrier technologies can effectively reduce the risk from media components. For some unit operations, M. orale and M. arginini may be hardier, and require more stringent processing or equipment cleaning conditions to assure effective mycoplasma reduction. By exploring how some of the failure modes in commercial antibody manufacturing processes can still eliminate mycoplasma burden, we demonstrate that required best practices assure biotechnology products will be safe for patients.

Ultraviolet-C irradiation for inactivation of viruses in foetal bovine serum.

Foetal Bovine Serum (FBS) and porcine trypsin are one of the essential raw materials used in the manufacturing of cell culture based viral vaccines. Being from animal origin, these raw materials can potentially contaminate the final product by known or unknown adventitious agents. The issue is more serious in case of live attenuated viral vaccines, where there is no inactivation step which can take care of such adventitious agents. It is essential to design production processes which can offer maximum viral clearance potential for animal origin products. Ultraviolet-C irradiation is known to inactivate various adventitious viral agents; however there are limited studies on ultraviolet inactivation of viruses in liquid media. We obtained a recently developed UVivatec ultraviolet-C (UV-C) irradiation based viral clearance system for evaluating its efficacy to inactivate selected model viruses. This system has a unique design with spiral path of liquid allowing maximum exposure to UV-C light of a short wavelength of 254 nm. Five live attenuated vaccine viruses and four other model viruses were spiked in tissue culture media and exposed to UV-C irradiation. The pre and post UV-C irradiation samples were analyzed for virus content to find out the extent of inactivation of various viruses. These experiments showed substantial log reduction for the majority of the viruses with few exceptions based on the characteristics of these viruses. Having known the effect of UV irradiation on protein structure, we also evaluated the post irradiation samples of culture media for growth promoting properties using one of the most fastidious human diploid cells (MRC-5). UV-C exposure did not show any notable impact on the nutritional properties of culture media. The use of an UV-C irradiation based system is considered to be promising approach to mitigate the risk of adventitious agents in cell culture media arising through animal derived products.

A model for the influences of soluble and insoluble solids, and treated volume on the ultraviolet-C resistance of heat-stressed Salmonella enterica in simulated fruit juices.

This study was conducted to determine the effects of intrinsic juice characteristics namely insoluble solids (IS, 0-3 %w/v), and soluble solids (SS, 0-70 °Brix), and extrinsic process parameter treated volume (250-1000 mL) on the UV-C inactivation rates of heat-stressed Salmonella enterica in simulated fruit juices (SFJs). A Rotatable Central Composite Design of Experiment (CCRD) was used to determine combinations of the test variables, while Response Surface Methodology (RSM) was used to characterize and quantify the influences of the test variables on microbial inactivation. The heat-stressed cells exhibited log-linear UV-C inactivation behavior (R2 0.952 to 0.999) in all CCRD combinations with DUV-C values ranging from 10.0 to 80.2 mJ/cm2. The DUV-C values obtained from the CCRD significantly fitted into a quadratic model (P < 0.0001). RSM results showed that individual linear (IS, SS, volume), individual quadratic (IS2 and volume2), and factor interactions (IS × volume and SS × volume) were found to significantly influence UV-C inactivation. Validation of the model in SFJs with combinations not included in the CCRD showed that the predictions were within acceptable error margins.

Chicken egg yolk plasma in tris-citric acid extender improves the quality and fertility of cryopreserved water buffalo (Bubalus bubalis) spermatozoa.

This study was primarily designed to evaluate the effect of different concentrations of ultraviolet (UV)-C-irradiated chicken egg yolk plasma (EYP; v:v; 10%, P1; 15%, P2; 20%, P3) or 20% (v:v) of whole chicken egg yolk (WCEY) in tris-citric acid (TCA) extender on water buffalo sperm quality during cryopreservation (postdilution, PD; postequilibration, PE; post-thawing, PT). Also the effect of best evolved concentration of UV-C-irradiated EYP in extender on in vivo fertility of buffalo spermatozoa was evaluated. At PE and PT, computer-assisted sperm analysis progressive motility (PM, %) was significantly higher in P3 compared with P1 and WCEY. Rapid velocity (RV, %) was higher (P < 0.05) in P3 compared with P1 and WCEY during cryopreservation (PD, PE, and PT). Average path velocity (µm/s) and straight line velocity (µm/s) were higher (P < 0.05) in P2 and P3 than WCEY at PE and PT. The decline percentage (%, longevity) in PM and RV was lower (P < 0.05) in P3 compared with WCEY during 2 hours incubation under in vitro condition at PT. Supravital plasma membrane integrity (%) was higher (P < 0.05) in P2 and P3 compared with control at different stages (PE and PT). Mitochondrial transmembrane potential (%) was higher (P < 0.05) in P2 and P3 compared with P1 and WCEY at different stages (PD and PT). Percentage of viable sperm with intact acrosome, and sperm DNA integrity (%) were higher (P < 0.05) in P2 and P3 compared with WCEY at PT. The in vivo fertility rate (%) was significantly higher with P3 compared with WCEY (76.61 vs. 64.49). In conclusion, WCEY (20%) can be replaced with UV-C-irradiated chicken EYP (20%) in TCA extender for cryopreservation of water buffalo spermatozoa.