Density Gradient Centrifugation Method Research Articles

#348 Neutrophil membrane-derived nanovesicles deliver IL-37 to repair renal endothelial cells in ischemia‒reperfusion injury

Abstract Background and Aims Renal ischemia‒reperfusion injury (IRI) is one of the most important causes of acute kidney injury (AKI). Interleukin (IL)-37 is a novel anti-inflammatory factor, but its application is still limited by its low stability and delivery efficiency. In recent years, engineered extracellular vesicles (EVs) have attracted substantial attention as an emerging drug delivery system. The aim of this study was to investigate the reparative effect of neutrophil membranes-derived nanovesicle (N-MV)-delivered IL-37 on renal IRI and its mechanism of action. Method The density gradient centrifugation method was used to extract peripheral blood neutrophils from rats, and the differential centrifugation method was used to extract neutrophil membranes. Cell membranes and IL-37 were then extruded with polycarbonate porous membranes with different pore sizes using a mini extruder to prepare IL-37 that was coated with neutrophil membrane (N-MV@IL-37). Subsequently, the physical and chemical properties and in vitro biological functions were identified. The in vivo distribution of N-MV@IL-37 as well as the renal function and inflammatory response in rats were further evaluated in a rat renal IRI model, and the targeting and anti-inflammatory mechanisms of N-MV@IL-37 were further explored. Results N-MV@IL-37 not only enhanced the stability of IL-37 but also targeted endothelial cells via P-selectin glycoprotein ligand-1 (PSGL-1) on neutrophil membrane surfaces. In vitro experiments showed that N-MV@IL-37 inhibited endothelial cell apoptosis and inflammatory factor production and promoted endothelial cell viability and angiogenesis. In the rat renal IRI model, N-MV@IL-37 inhibited renal cell apoptosis and alleviated inflammatory responses, thereby improving renal function in IRI rats. Conclusion N-MVs provide an effective method of delivering IL-37, thereby alleviating the inflammatory response due to renal IRI and repairing renal endothelial cells; these vesicles could be a potential system for the treatment of renal IRI. Meanwhile, N-MVs also provided a drug delivery platform to provide a new strategy for the treatment of other IRI-like diseases.

A Comparative Study of B Cell Blast Isolation Methods from Bone Marrow Aspirates of Pediatric Leukemia Patients.

Density gradient centrifugation is a conventional technique widely utilized to isolate bone marrow mononuclear cells (BM-MNC) from bone marrow (BM) aspirates obtained from pediatric B-cell acute lymphoblastic leukemia (B-ALL) patients. Nevertheless, this technique achieves incomplete recovery of mononuclear cells and is relatively time-consuming and expensive. Given that B-ALL is the most common childhood malignancy, alternative methods for processing B-ALL samples may be more cost-effective. In this pilot study, we use several readouts, including immune phenotype, cell viability, and leukemia-initiating capacity in immune-deficient mice, to directly compare the density gradient centrifugation and buffy coat processing methods. Our findings indicate that buffy coat isolation yields comparable BM-MNC product in terms of both immune and leukemia cell content and could provide a viable, lower cost alternative for biobanks processing pediatric leukemia samples.

Microfluidic sperm sorting selects a subpopulation of high-quality sperm with a higher potential for fertilization.

Is a microfluidic sperm sorter (MSS) able to select higher quality sperm compared to conventional methods? The MSS selects sperm with improved parameters, lower DNA fragmentation, and higher fertilizing potential. To date, the few studies that have compared microfluidics sperm selection with conventional methods have used heterogeneous study population and have lacked molecular investigations. The efficiency of a newly designed MSS in isolating high-quality sperm was compared to the density-gradient centrifugation (DGC) and swim-up (SU) methods, using 100 semen samples in two groups, during 2023-2024. Semen specimens from 50 normozoospermic and 50 non-normozoospermic men were sorted using MSS, DGC, and SU methods to compare parameters related to the quality and fertilizing potential of sperm. The fertilizing potential of sperm was determined by measurement of phospholipase C zeta (PLCζ) and post-acrosomal sheath WW domain-binding protein (PAWP) expression using flow cytometry, and the chromatin dispersion test was used to assess sperm DNA damage. In both normozoospermic and non-normozoospermic groups, the MSS-selected sperm with the highest progressive motility, PLCζ positive expression and PLCζ and PAWP fluorescence intensity the lowest non-progressive motility, and minimal DNA fragmentation, compared to sperm selected by DGC and SU methods (P < 0.05). The major limitations of our study were the low yield of sperm in the MSS chips and intentional exclusion of severe male factor infertility to yield a sufficient sperm count for molecular experiments; thus testing with severe oligozoospermic semen and samples with low count and motility is still required. In addition, due to ethical considerations, at present, it was impossible to use the sperm achieved from MSS in the clinic to assess the fertilization rate and further outcomes. Our research presents new evidence that microfluidic sperm sorting may result in the selection of high-quality sperm from raw semen. This novel technology might be a key to improving clinical outcomes of assisted reproduction in infertile patients. The study is funded by the Iran University of Medical Sciences and no competing interest exists. N/A.

Methods to Isolate Muscle Stem Cells for Cell-Based Cultured Meat Production: A Review.

Cultured meat production relies on various cell types, including muscle stem cells (MuSCs), embryonic stem cell lines, induced pluripotent cell lines, and naturally immortalized cell lines. MuSCs possess superior muscle differentiation capabilities compared to the other three cell lines, making them key for cultured meat development. Therefore, to produce cultured meat using MuSCs, they must first be effectively separated from muscles. At present, the methods used to isolate MuSCs from muscles include (1) the pre-plating method, using the ability of cells to adhere differently, which is a biological characteristic of MuSCs; (2) the density gradient centrifugation method, using the intrinsic density difference of cells, which is a physical characteristic of MuSCs; and (3) fluorescence- and magnetic-activated cell sorting methods, using the surface marker protein on the cell surface of MuSCs, which is a molecular characteristic of MuSCs. Further efficient and valuable methods for separating MuSCs are expected to be required as the cell-based cultured meat industry develops. Thus, we take a closer look at the four methods currently in use and discuss future development directions in this review.

Sperm Preparation with Microfluidic Sperm Sorting Chip May Improve Intracytoplasmic Sperm Injection Outcomes Compared to Density Gradient Centrifugation.

Does sperm preparation using the FERTILE PLUS™ Sperm Sorting Chip improve fertilization rates, blastocyst formation, utilization, and euploidy rates in patients undergoing intracytoplasmic sperm injection (ICSI), compared with density gradient centrifugation (DGC)? A single-cohort, retrospective data review including data from 53 couples who underwent ICSI cycles within a 12-month period. For each couple, the two closest, consecutive cycles were identified, where one used the standard technique of sperm preparation (DGC) and the subsequent used FERTILE PLUS™, therefore, couples acted as their own controls. Paired samples t-test was used to compare means for the outcomes (fertilization, blastocyst formation, utilization, and euploidy rates). Binary logistic regression analysis assessed the relationship between female age, the presence of male factor infertility, and euploidy rates. Blastocyst, utilization, and euploidy rates were significantly higher for cycles using FERTILE PLUS™ compared to DGC (76% vs 56%, p = 0.002; 60% vs 41%, p = 0.005, and 40% vs 20%, p = 0.001, respectively). Although there was an increase in fertilization rates for cycles using FERTILE PLUS™, this was not significant (72% vs 68%, p = 0.449). The euploidy rates of females ≤ 35 years were significantly increased when the FERTILE PLUS™ sperm preparation method was used, compared to the older age group (OR 2.31, p = 0.007). No significant association was found between the presence or absence of male factor infertility and euploidy rates between the two cycles. This study provides tentative evidence that the FERTILE PLUS™ microfluidic sorting device for sperm selection can improve blastocyst formation, utilization, and euploidy rates following ICSI in comparison to the DGC method.

Swim-up method is superior to density gradient centrifugation for preserving sperm DNA integrity during sperm processing.

This study aimed to evaluate the effects of swim-up and density gradient centrifugation methods on sperm DNA fragmentation. Nineteen normozoospermic patient samples with ≥100 × 106 motile sperms were included in this study. Sperm DNA fragmentation, progressive motility, and progressive motile sperm number were measured before and after the swim-up method or density gradient centrifugation. Sperm DNA fragmentation was not statistically different between swim-up-(14.4 ± 2.1%, p = 0.32) and density gradient centrifugation-processed (25.0 ± 3.0%, p = 0.20) and unprocessed semen samples (19.2 ± 1.9%). Sperm DNA fragmentation was significantly lower in swim-up-than in density gradient centrifugation-processed samples (p < 0.05). Sperm progressive motility was significantly higher (p < 0.05) in swim-up-(92.9 ± 1.0%) and density gradient centrifugation-processed (81.3 ± 2.0%) samples, with the former being higher, than in unprocessed semen samples (53.1 ± 3.7%). The recovery rate of progressive motile sperms was significantly lower in swim-up-(9.7 ± 1.4%) than in density gradient centrifugation-processed samples (17.2 ± 1.8%, p < 0.05). The swim-up method is superior to density gradient centrifugation, evidenced by less sperm DNA fragmentation and higher sperm progressive motility. The recovery rate of progressive motile sperms was better after density gradient centrifugation than after swim-up.

A Novel, Efficient Method to Isolate Chicken Primordial Germ Cells from Embryonic Blood Using Cell Culture Inserts.

Primordial germ cells (PGCs) play a crucial role in preserving poultry genetic resources and conducting transgenic research. A system for the rapid isolation of PGCs from single chicken embryonic blood was established in this paper. We found that PGCs can migrate to the lower layer of chicken embryonic fibroblasts (CEFs) through pores smaller than their diameter, while blood cells cannot, when co-cultured with CEFs of passages two to three. Based on the characteristics of PGCs, we developed a new PGC isolation method (cell culture insert/CEF adhesion method) that utilizes a 3 μm cell culture insert and CEFs of passages two to three. Using this method, approximately 700 PGCs can be isolated from the blood of a single chicken embryo at Hamburger and Hamilton (H&H) stage 17 of development. The separation rate achieved was 87.5%, with a separation purity of 95%. The separation rate of this method was 41.4% higher than the common Percoll density gradient centrifugation method and 33.6% higher than lysis with ACK buffer. PGCs isolated from embryonic blood could proliferate 37-fold within 2 weeks when cultured in a feeder-free culture system. They also continued to express the SSEA-1 and DAZL proteins and retained the ability to migrate in vivo. Overall, PGCs separated using cell culture inserts/CEF adhesion method retain their stem cell characteristics and migration ability. PGCs also exhibit good proliferation efficiency, making them suitable for subsequent transgenic experiments or genetic resource preservation.

#353 : Microfluidic Preparation of Spermatozoa: A Potential Approach in Assisted Reproductive Technology

Background and Aims: While density gradient centrifugation (DGC) is a conventional method in sperm preparation, this method can induce reactive oxygen species (ROS) which cause sperm dysfunction, sperm DNA damage, a recent advancement in sperm processing using microfluidic system is believed to reduce damage and to select the good quality sperm. The aim of this study was to evaluate the effectiveness of sperm preparation between DGC method and microfluidic system. Method: 30 semen samples were separated into 2 equal small samples, each sample was processed by DGC methods (control) and microfluidic (intervention) respectively. Pre- and post processing parameters was evaluated according to WHO-2010 and the DNA fragmentation index (DFI) was determined by flow cytometry technique. Results: The result showed that DFI values from the microfluidic preparation (0.67 ± 0.53%) was significantly lower than that of the DCG group (1.18 ± 13.73%). In particular, for semen samples with high DFI (&gt;15%), the microfluidic system showed a noticeable reduction in DFI compared to the results from the DGC method. The progressive motile sperm recovery rate was higher in the intervention group (39.75 ± 19.20 vs 32.14 ± 18.14). Our data also showed that the vitality and mobility of sperm in the microfluidic group was higher than those of the DGC group (97.9 ± 2.21 vs 96.56 ± 4.11%, 96.36 ± 2.60 vs 95.06 ± 2.35%, respectively). However, there was no difference in sperm progressive motility and sperm morphology between two groups. Conclusions: There were significant improvement in sperm DFI and progressive motility in the microfluidic system. With this result, microfluidic system is a potential approach to reduce DNA fragmentation for ICSI procedures.

Aldehyde Dehydrogenase Enzyme in Relation to Cord Blood stem cells Potency

Abstract Introduction/Objective In umbilical cord blood transplantation (UCBT), the number of cluster of differentiation (CD)34+ cells and colony-forming units (CFUs) in the cord blood (CB) graft positively correlate with patient survival. Since aldehyde dehydrogenase (ALDH) activity is high in hematopoietic stem cells, the number of ALDH-bright (ALDHbr) cells was examined in comparison with the number of CD34+ cells and CFUs for the quality assessment of CB units, Aim and objectives; to correlate the aldehyde dehydrogenase (ALDH) enzyme assay with colony-forming unit–granulocyte/macrophage (CFU-GM) assay before cryopreservation of cord blood buffy coats (CBBC), in order to investigate the hypothesis that the ALDH assay might exclude apoptotic cells since it is based on enzyme activity. Methods/Case Report This study was carried out at Benha University Hospital on Fifty (50) samples of Human Umbilical Cord Blood which were processed for mononuclear cells (MNC) separation by density gradient centrifugation method using Ficoll-Paque media that layered on the diluted blood. In parallel, 1 million nucleated cells were sampled and prepared for flow cytometry for analysis of ALDH activity according to the manufacturer’s instructions. Results (if a Case Study enter NA) CD34+ ALDH+ (%) (Of MNC) showed significant positive correlation with ALDH++ (%) (Of CD34+) and numbers of total CFU/40000 cells. Also ALDH++ (%) (Of CD34+) showed significant positive correlation with numbers of total CFU/40000 cells. Conclusion The ALDH assay excludes nonviable and apoptotic cells, and therefore correlates well with CFU enumeration compared to the number of viable CD34+ cells. We propose that the ALDH assay might replace the CFU-GM method in CBU potency measurements.

The efficacy of various protocols of colloidal centrifugation of bovine sperm for IVF

The article presents data on the effectiveness of using various sperm preparation protocols by colloidal centrifugation (density gradient centrifugation method) before procedures of assisted reproductive technologies, including in vitro artificial insemination. The use of the method can affect the quality of sexual gametes and the viability of embryos, increase the percentage of successful embryotransplantation and contribute to the appearance of highly productive offspring.As a result of the research, the most optimal protocol of centrifugation by the method of gradient layering with indicators of the first and second centrifugation 700g – 20 min and 100g – 10 min, respectively, was determined by morphofunctional characteristics. The average rate of motile spermatozoa was 84.1±5.1%, progressive spermatozoa – 68.7±5.1%, the rate of rectilinear translational motion was 49.69 microns/sec. Morphology and viability meet quality standards.

Percoll discontinuous density gradient centrifugation method for the fractionation of the subpopulations of Mycobacterium smegmatis and Mycobacterium tuberculosis from in vitro cultures

Bacterial populations in the in vitro laboratory cultures, environment, and patients contain metabolically different subpopulations that respond differently to stress agents, including antibiotics, and emerge as stress tolerant or resistant strains. To contain the emergence of such strains, it is important to study the features of the metabolic status and response of the subpopulations to stress agents. For this purpose, an efficient method is required for the fractionation and isolation of the subpopulations from the cultures. Here we describe in detail the manual setting up of a simple, easy-to-do, reproducibly robust Percoll discontinuous density gradient centrifugation for the fractionation of subpopulations of short-sized cells (SCs) and normal/long-sized cells (NCs) from Mycobacterium smegmatis and Mycobacterium tuberculosis cultures, which we had reported earlier. About 90-98% enrichment was obtained respectively for SCs and NCs for M. smegmatis and 69-67% enrichment was obtained respectively for the SCs and NCs for M. tuberculosis.•The Percoll discontinuous density gradient centrifugation helps the fractionation and isolation of mycobacterial subpopulations that differ in density.•The method offers a consistently reproducible high enrichment of the subpopulations of SCs and NCs from the in vitro cultures of M. smegmatis and M. tuberculosis.•Our earlier reports on the consistency in the differential response of the subpopulations, enriched using the method, to oxidative, nitrite, and antibiotic stress proves its validity.

Promising effects of exosomes from menstrual blood-derived mesenchymal stem cells on endometriosis

Endometriosis as a non-malignant gynecological disease leads to dysregulation of numerous cellular functions including apoptosis, angiogenesis, migration, proliferation, and inflammation. Accumulating evidence has shed light on the importance of endometrial stem cells within the menstrual blood which are involved in the establishment and progression of endometriotic lesions in a retrograde manner. According to the fact that the therapeutic benefits of mesenchymal stem cells are provided through paracrine functions, we used exosomes from menstrual blood-derived stem cells (MenSCs) for treating endometriotic stem cells to inhibit their lesion formation tendency. Menstrual blood samples from healthy and endometriosis women were collected. Isolated MenSCs by the density-gradient centrifugation method were characterized by flow cytometry. Secreted exosomes were isolated from healthy MenSCs (NE-MenSCs) and used to treat endometriotic cells (E-MenSCs). 72 h after treatment, different mechanisms and pathways including inflammation, proliferation, apoptosis, migration, and angiogenesis were analyzed using Real-Time PCR, ELISA, immunocytochemistry, annexin V/PI, and scratching assay. Exosome treatment significantly reduce the expression level of markers related to inflammation, proliferation, migration, and angiogenesis in E-MenSCs which are aberrantly expressed in endometriosis. Moreover, apoptosis was induced in E-MenSCs after treatment which was evaluated in both gene and protein levels. In this study, we give preliminary evidence for the potential of MenSCs-Exo in ameliorating endometriosis. Regarding our results, we suggest that after relevant clinical trial, MenSCs-derived exosomes can be considered as a better treatment option to improve endometriosis compared to common and conventional treatments and show their potential as a cell-free product in endometriosis repair.

Time- and Concentration-Dependent Adverse Effects of Paclitaxel on Non-Neuronal Cells in Rat Primary Dorsal Root Ganglia.

Paclitaxel is a chemotherapeutic agent used to treat a wide range of malignant tumors. Although it has anti-tumoral properties, paclitaxel also shows significant adverse effects on the peripheral nervous system, causing peripheral neuropathy. Paclitaxel has previously been shown to exert direct neurotoxic effects on primary DRG neurons. However, little is known about paclitaxel's effects on non-neuronal DRG cells. They provide mechanical and metabolic support and influence neuronal signaling. In the present study, paclitaxel effects on primary DRG non-neuronal cells were analyzed and their concentration or/and time dependence investigated. DRGs of Wister rats (6-8 weeks old) were isolated, and non-neuronal cell populations were separated by the density gradient centrifugation method. Different concentrations of Paclitaxel (0.01 µM-10 µM) were tested on cell viability by MTT assay, cell death by lactate dehydrogenase (LDH) assay, and propidium iodide (PI) assay, as well as cell proliferation by Bromodeoxyuridine (BrdU) assay at 24 h, 48 h, and 72 h post-treatment. Furthermore, phenotypic effects have been investigated by using immunofluorescence techniques. Paclitaxel exhibited several toxicological effects on non-neuronal cells, including a reduction in cell viability, an increase in cell death, and an inhibition of cell proliferation. These effects were concentration- and time-dependent. Cellular and nuclear changes such as shrinkage, swelling of cell bodies, nuclear condensation, chromatin fragmentation, retraction, and a loss in processes were observed. Paclitaxel showed adverse effects on primary DRG non-neuronal cells, which might have adverse functional consequences on sensory neurons of the DRG, asking for consideration in the management of peripheral neuropathy.

P-782 The influence of microfluidic preparation of spermatozoa for ICSI (intracytoplasmic sperm injection) in an unselected IVF population on fertilization rate, embryo-quality and pregnancy rate

Abstract Study question Does the microfluidic technique as a new preparation option for sperm in ICSI during IVF have a better outcome in fertilization, blastocysts and pregnancy rate? Summary answer The patients that had the sperm preparation for ICSI with the microfluidic sperm selection had similar results as with the gradient centrifugation selection. What is known already Semen analysis is a poor predictor of the fertilization potential of spermatozoa and a male factor may contribute to poor outcomes of IVF procedure despite a normal semen analysis. Traditionally, sperm processing is accomplished by density gradient centrifugation or swim-up methods but this have been shown in some studies to increase reactive oxygen species and induce sperm DNA fragmentation. The microfluidic sperm selection (ZyMot- ICSI) is based on the selection of the spermatozoa with the lowest DNA fragmentation rate but studies do not prove better clinical outcomes after this method. Study design, size, duration This is a prospective randomized study carried out in a university level fertility clinic in Oradea, Romania from January 2022 to December 2022, including 239 patients in total. The patients that underwent IVF-ICSI procedures for various indications were randomized in two groups: the control group swim-up technique was used for sperm selection for ICSI during IVF and the study group with the ZyMot-ICSI (microfluidic sperm selection technique) was used. Participants/materials, setting, methods We conducted a prospective trial comparing 119 couples that were allocated to the classic swim-up technique (control group) and 120 couples that were allocated with the microfluidic technique was used (study group) in our university level clinic to go through IVF. Inclusion criteria were couples with known infertility requiring IVF and willing to participate in the study. Exclusion criteria were: severe oligoasthenospermia (concentration &amp;lt; 5x10^6 spermatozoa/ml or motility &amp;lt;10%), oocyte or sperm donation. Main results and the role of chance The statistical analysis showed that there is no significant difference between the fertilization rate (study vs control p = 0.37 with absolute difference -1.182, 95% CI (-7.2, 5.4)) or blastocyst rate (study vs control p = 0.88 with absolute difference -0.5 95% (-6.5, 6)) nor is there a difference in clinical pregnancy. Even if microfluidic preparation of spermatozoa did not seem to improve the results it may be utilized more broadly for standard IVF, intrauterine insemination and could also improve workflow, decrease intervention by laboratory personal and provide more consistent incubation conditions. Limitations, reasons for caution The population studied was inclusive with unselected IVF indications and did not attempt to isolate male factor infertility cases or patients with a history of elevated sperm DNA fragmentation. Wider implications of the findings Microfluidic sperm preparation performs similarly to density gradient centrifugation in sperm preparation for IVF in an unselected population. Trial registration number Not applicable

Sperm processing methods effectively reduce the DNA fragmentation index in samples with high initial values

The DNA fragmentation index (DFI) in spermatozoa is correlated to in vivo fertility in animals and outcomes in Human Assisted Reproductive Techniques (ARTs). Different sperm selection methods aim to select the most viable sperm population and reduce the DFI after processing. However, it remains unclear which selection method most efficiently reduces DFI and to what extent initial levels in raw semen can be improved to justify the use of these alternative procedures. We hypothesized that sperm selection methods would efficiently reduce the percentage of cells with DNA damage mainly to samples with high initial values. In this study we evaluated frozen-thawed equine spermatozoa from 12 different stallions subjected to four different treatments as follows: i) control / no selection (CN); ii) density gradient centrifugation (DGC); iii) swim up (SU); and iv) a microfluidic chamber (MF). After processing, DFI levels were evaluated based on the percentage of cells outside of the main population (COMPαt) from the Sperm Chromatin Structure Assay (SCSA) as described by Evenson et al., (2013). Levels of COMPαt in the control samples (CN) were used to categorize them as LOW and HIGH based on a median split (Mdn:12.37%). Statistical analysis was performed using R (R Core Team, Vienna, Austria, v3.6.0) to fit a mixed linear regressionmodel. Fixed effects in the model included treatment (CN, DGC, SU and MF) and initial DFI levels (LOW or HIGH). Random effect in the model included stallion (n=12) and effects were retained in the model when p<0.05. There was a significant interaction between treatment and initial DNA fragmentation levels (p<0.00001). In samples with HIGH DFI, COMPαt had a mean of (20.44% ±1.68) for CN and was not significantly different from samples processed by DGC (14.36%±1.68; p=0.07). However, a significant reduction in COMPαt was observed after SU (2.97% ± 1.68; p<0.0001) and MF (1.95% ± 1.68; p<0.0001) in this group. On the other hand, among samples in the LOW DFI group, COMPαt had a mean of (8.32% ±1.68) for CN, which was not significantly different when compared to DGC (7.34%±1.68; p=0.99), SU (3.24%±1.68; p=0.2) or MF (2.07% ±1.68; p=0.059) selection methods. These results demonstrate that SU and MF were the most effective at reducing the percentage of cells with DNA fragmentation (COMPαt) when the initial DFI was considered HIGH. However, in samples with LOW DFI, there was no significant improvement in COMPαt by any selection method. Clinical categorization of initial sperm DFI may be warranted to determine the fecundity of sires and be useful for selecting appropriate sperm selection methods for equine ARTs.

Efficiency of Density Gradient Centrifugation Method (Ludox method) Based on eDNA for the Analysis of Harmful Algal Bloom Potential

Efficiency of Density Gradient Centrifugation Method (Ludox method) Based on eDNA for the Analysis of Harmful Algal Bloom Potential

Comparison between density gradient centrifugation method, an extended version of the horizontal swim up method and the combination of both for sperm selection.

To compare the degree of efficiency between density gradient centrifugation (DGC) method and an extended horizontal swim-up (SU) method. A total of 97 couples undergoing in vitro fertilization were enrolled in the study. Semen samples were divided into three aliquots and treated using DGC, extended horizontal SU, and combined methods. DNA fragmentation and chromatin decondensation were detected in native semen samples and their three corresponding aliquots. The corresponding mature oocytes of each semen sample were divided into two sibling cultures. The first sibling culture was microinjected with semen pellets from DGC, and the second sibling culture was microinjected with semen pellets from the combination of both methods. Fertilization rate and embryonic development were assessed at day 3. DNA fragmentation and chromatin decondensation was significantly low in DGC and extended horizontal SU samples; however, the rates of DNA fragmentation and chromatin decondensation were significantly lower in extended horizontal SU samples than in DGC samples. The lowest rates of DNA fragmentation and chromatin decondensation corresponded to the samples treated with both methods. The highest rates of DNA fragmentation and chromatin decondensation corresponded to the samples treated with DGC. No significant difference was found in the fertilization rate or day 3 embryos between sibling cultures. The combination of DGC and the extended horizontal SU techniques is best for giving the lowest rates of sperm DNA fragmentation and chromatin decondensation.

Development of a novel cervix-inspired tortuous microfluidic system for efficient, high-quality sperm selection.

Microfluidic systems have been extensively studied in recent years as potential alternatives for problematic conventional methods of sperm selection. However, despite the widespread use of simple straight channels in these systems, the impact of channel geometry on selected sperm quality has not been thoroughly investigated. To explore this further, we designed and fabricated serpentine microchannels with different radii of curvature, inspired by the tortuous structure of the cervix. Our results showed that in the presence of gentle backflow, microfluidic channels with a 150 μm radius of curvature significantly enhanced the quality of selected sperms when compared to straight channels. Specifically, we observed significant improvements of 7% and 9% in total motility and progressive motility, respectively, as well as 13%, 18%, and 19% improvements in VCL, VAP, and VSL, respectively. Through careful observation of the process, we discovered a unique near-wall sperm migration pattern named boundary detachment-reattachment (BDR), that was observed exclusively in curved microchannels. This pattern, which is a direct consequence of the special serpentine geometry and sperm boundary-following characteristic, contributed to the superior selection performance when combined with a fluid backflow. After determining the best channel design, we fabricated a parallelized chip consisting of 85 microchannels capable of processing 0.5 ml of raw semen within 20 minutes. This chip outperformed conventional methods of swim-up and density gradient centrifugation (DGC) in terms of motility (9% and 25% improvements, respectively), reactive oxygen species (18% and 15% improvements, respectively), and DNA fragmentation index (14% improvement to DGC). Outstanding performance and advantages such as user-friendliness, rapid selection, and independence from centrifugation make our microfluidic system a prospective sperm selection tool in clinical applications.

The Quality and Proportion of Spermatozoa X and Y in Sexed Frozen Semen Separated with Percoll Density Gradient Centrifugation Method on Friesian Holstein Bull

The Quality and Proportion of Spermatozoa X and Y in Sexed Frozen Semen Separated with Percoll Density Gradient Centrifugation Method on Friesian Holstein Bull

Increased Perforin- and IL-21-Expressing NK Cells in Patients with Early-Stage Chronic Lymphocytic Leukemia

Objective: CD5+CD19+ cells have a low proliferation capacity and elevated expression of anti-apoptotic protein BCL-2, mostly in the G0/ G1 cell phase and accumulate in the pathogenesis of chronic lymphocytic leukemia (CLL). Natural killer (NK) cells have the ability to kill the intracellular pathogen-infected or cancer cells and secrete cytotoxic enzymes. This study evaluated the frequency, expression of cytotoxic enzymes, and intracellular cytokine levels of NK cells in CLL patients. Materials and Methods: In this study, peripheral blood mononuclear cells were isolated from peripheral blood samples of CLL patients (n=29) and healthy controls (n=16) by density gradient centrifugation method. The frequency of the total NK cells and the intracellular levels of perforin, granzyme, interferon (IFN)-γ, interleukin (IL)-21, IL-4 and IL-17 in NK cells were investigated. Results: Elevated total NK cell frequency were found in the CLL patients compared to the healthy controls, and negatively correlated with CD5+CD19+ malign B cell frequency. Increased perforin expression was observed in patients’ total NK cells. Additionally, increased levels of IL-17 and IL-21 in total NK cell of CLL patients were obtained compared to healthy subjects. Conclusion: The findings suggest that in the early stage of CLL, increased total NK cell frequency, and elevated perforin and IL-21 levels in NK cells might have a protective impact against the progression of the disease for CLL patients.