Study on Seminal Attributes of X- sperm Enriched Sahiwal Bull Semen

The present study was conducted to observe the effect of percoll density gradient centrifugation on quality of semen. Ejaculates were collected by AV method from Sahiwal bulls. X-sperm enrichment was done by percoll density gradient method i.e. 7 layers (70-10%). Centrifugation was done at 750 g (22-24°C) for 15 min. The pellets obtained were diluted in EYC medium. Semen quality was evaluated in fresh semen (Control), in pellet of normal centrifugation (Group I), supernatant of centrifugation in percoll density gradient (Group II) and pellet of centrifugation in percoll density gradient (Group III). To assess the quality of enriched semen pH, mass motility, progressive motility, live spermatozoa %, abnormal spermatozoa %, HOST % and intact acrosome % were evaluated. Number of progressively motile sperms in pellet of X- enriched semen were non-significantly increased and significantly (P<0.05) decreased in supernatant. The abnormal spermatozoa (%) were decreased in G III as compared to G II Live spermatozoa (%) were increased in enriched semen (pellet). Number of Intact sperms decreased significantly (P<0.05) in supernatant of percoll density gradient centrifuged Sahiwal semen. HOST responsive sperms number was not affected after percoll density gradient centrifugation. Thus, the semen quality of X-sperm enriched semen by percoll density gradient method (7 layer 70%) was not affected hence it can be used to increase female calves’ birth after A.I.

Correlation between adhesion molecules on the surface of red blood cell membrane and red blood cell lifespan / 中国输血杂志

【Objective】 To explore the correlation between red blood cell lifespan and adhesion molecules on the surface of red blood cell membrane, in order to establish a method to detect the duration of red blood cell storage. 【Methods】 10 samples(10 mL each) of fresh red blood cell, collectedf rom 10 healthy voluntary blood donors, were divided into 5 age groups (layers) by Percoll density gradient centrifugation. The expression of CD47, CD44 and CD147 on the surface of red blood cell membrane in each layer was detected using flow cytometry. The variance of protein expression in each layer of red blood cells was analyzed by SPSS statistical software. 【Results】 The expression levels (%) of 3 adhesion molecules on the surface of red blood cell membranes from young to old were CD47: 14.44±2.61, 9.30±1.75, 7.84±1.49, 6.54±1.32 and 5.53±1.12 (P<0.01); CD44: 25.01±1.94, 19.22±1.52, 17.10±1.28, 15.18±1.11 and 13.56±1.08 (P<0.01); CD147: 33.46±1.99, 28.31±2.95, 23.83±1.59, 20.40±1.56 and 18.03±1.65 (P<0.01). 【Conclusion】 The expression levels of CD47, CD44 and CD147 on the surface of red blood cell membranes have showed a downward trend as the storage extended. These three protein adhesion molecules have showed a correlation with red blood cells lifespan, and could be used as detection markers of cell age.

Mini-percoll gradient may be used for frozen-thawed sperm selection in sheep / Gradiente de mini-Percoll pode ser utilizado na seleção espermática de sêmen congelado de ovinos

This study evaluated the effect of increasing centrifugal force and reducing centrifugation time and volume in Percoll protocols on ram sperm parameters. Commercial semen of Santa Inês rams were used and five treatments were performed: traditional Percoll and mini-Percoll (MP) techniques (I- 5000 x g, 5min; II- 2500 x g, 5min; III- 1250 x g, 5min; IV- 700 x g, 10min). At post-thawing (PT) and post-selection protocols (0h), samples were assessed for spermatozoa recovery rate, motility, plasma membrane (PM) integrity, sperm capacitation and morphology and incubated at 37 C for 1, 2 and 3h. The sperm recovery rate averaged 9.1±1.4%, and most motility parameters were similar (P> 0.05) among protocols. VCL (µm/s) was higher (P< 0.05) after MP-II, III and IV (66.1±4.5) than traditional Percoll (46.3±4.9). Capacitation status and PM integrity were similar (P> 0.05) among treatments. For the first time, we have demonstrated the reduction of the gradient volume and centrifugation time associated with an increase on centrifugation force at Percoll can be successfully used for frozen-thawed ram sperm selection. MP may be used instead of traditional Percoll, decreasing costs and semen handling time.(AU)

O presente estudo avaliou o efeito do aumento da força de centrifugação, bem como da redução do tempo de centrifugação e do volume do gradiente de Percoll em diferentes protocolos nos parâmetros espermáticos de ovinos. Foi utilizado sêmen comercial de carneiros da raça Santa Inês, e cinco tratamentos foram realizados: Percoll tradicional e quatro técnicas de mini-Percoll (I- 5000 x g, 5min; II- 2500 x g, 5min; III- 1250 x g, 5min; IV- 700 x g, 10min). Após o descongelamento e a seleção espermática em cada técnica utilizada (0h), amostras foram avaliadas quanto à taxa de recuperação espermática, motilidade, integridade de membrana plasmática, capacitação e morfologia. Ao final, foram incubadas a 37 ºC por uma, duas e três horas. A taxa de recuperação média (9,1±1,4%) e a maioria dos parâmetros de motilidade foram similares (P>0,05) entre os tratamentos. VCL foi maior (P<0,05) após MP-II, III e IV (66,1±4,5) quando comparados ao Percoll tradicional (46,3±4,9). O status da capacitação e a integridade de membrana foram similares (P>0,05) entre os tratamentos. Pela primeira vez, foi demonstrado que a redução do volume do gradiente utilizado e do tempo de centrifugação, associada com o aumento da força de centrifugação nos protocolos de Percoll, pode ser usada com sucesso na seleção espermática de sêmen congelado de ovinos. O mini-Percoll pode ser utilizado em alternativa à técnica de Percoll tradicional, diminuindo custos e tempo de manipulação do sêmen durante a técnica.(AU)

Isolation of mononuclear cells from CNS tissue using Percoll gradients centrifugation / 中国药理学通报

Aim To establish a rapid method to efficiently iso-late mononuclear cells from central nervous system ( CNS) tis-sues of mice that can be effectively utilized for identification of various immune cell populations in a single sample by flow cy-tometry. Methods For defining the feasibility and practicality of the method, wild-type C57BL/6 mice and two mouse models of CNS disease including EAE mice and APP/PS1 mice were used in this study. After the collection and homogenization of the brain and spinal cord tissues respectively, the mononuclear cells were isolated by spinning the 70% -30% Percoll gradients. Cell activities were detected by trypan blue staining, and the im-mune population that infiltrated CNS was identified by flow cy-tometry. Results The results of trypan blue staining showed that the survival rate of the isolated cells was above 90% in all groups. Flow cytometry analysis showed that the relative num- bers of lymphocytes infiltrating CNS of EAE and AD mice in-creased significantly compared with wild-type C57BL/6 mice. In addition, the relative numbers of Th1 and Th17 cell subsets me-diating the inflammatory response also increased significantly, while the decreased regulatory T cells frequency was observed in the two mouse models of CNS disease. Conclusions The cells isolated by the 70% ~30% Percoll gradients centrifugation can be effectively utilized for the identification of various immune cell populations in a single sample by flow cytometry. The meth-od described in this article is simple and rapid in operation and with high survival rate and activity of the cells, which can be ap-plied to the study of the mononuclear cells in CNS.

Effect of sperm selection techniques in frozen/thawed cat spermatozoa on sperm motility analyzed by CASA system / Efecto de técnicas de selección espermática en espermatozoides congelados/descongelados de gato sobre la motilidad espermática analizada mediante sistema CASA

SUMMARY: Freeze/thawing process reduces sperm survival and fertilizing ability of cat spermatozoa, with sperm motility being the most sensitive sperm parameter altered, due to cryo-damage. In this context, swim-up and density gradient processing methods can help to recover high motile and normal spermatozoa. Maximizing the use of frozen semen sample is essential, especially in endangered felids or high value cats in which sample size, number of samples or access to semen collection is reduced. To our knowledge, there is no previous report describing an in depth analysis of sperm motility improvement, after sperm selection techniques in frozen cat semen. Accordingly, we evaluated the effect of percoll gradient (PG) and swim up (SU) sperm selection techniques on sperm motility parameters and sperm recovery rate in frozen/thawed spermatozoa of domestic cat. Next, we evaluated the individual effect of the cat over sperm motility after PG sperm selection of frozen/thawed spermatozoa. SU and PG improved significantly all sperm motility parameters of frozen/thawed cat spermatozoa compared to simple washing. However, PG allows better sperm recovery from the original frozen sample and works mostly homogeneously among individual cats. This new information could help to maximize the use of frozen semen in endangered felids or high value domestic cats for its subsequent application on in vitro fertilization and artificial insemination.

RESUMEN: El proceso de congelación/descongelación reduce la sobrevivencia espermática y la habilidad para fertilizar en los espermatozoides de gato, siendo la motilidad espermática el parámetro más sensiblemente alterado debido al daño por frío. En este contexto, los métodos de procesamiento de swim-up y gradiente de densidad pueden ayudar a recuperar los espermatozoides normales y de alta motilidad. Maximizar el uso de una muestra de semen congelado es esencial, especialmente en felinos amenazados o en gatos de alto valor en los cuales el tamaño de muestra, número de muestras o el acceso a la colecta de semen son reducidos. Para nuestro conocimiento, no hay reportes previos que describan un análisis profundo del mejoramiento de la motilidad luego de técnicas de selección espermática en semen congelado de gato. De acuerdo a esto, evaluamos el efecto de las técnicas de selección espermática gradiente de percoll (PG) y swim up (SU) sobre los parámetros de motilidad y porcentaje de recuperación de espermatozoides congelados/descongelados de gato doméstico. Luego, evaluamos el efecto individual del gato sobre la motilidad espermática luego de la selección espermática con PG en espermatozoides congelados/descongelados. SU y PG mejoraron significativamente todos los parámetros de motilidad espermática de los espermatozoides congelados/descongelados comparado con el lavado simple. Sin embargo, PG permitió una mejor recuperación de espermatozoides desde la muestra congelada original y funcionó en su mayoría de manera homogénea entre los gatos individualmente. Esta nueva información puede ayudar a maximizar el uso del semen congelado en felinos amenazados o en gatos de alto valor para su posterior aplicación en fecundación in vitro e inseminación artificial.

A comparative study of tumor-associated macrophages isolation in colorectal carcinoma by Ficoll-Hy-paque density gradient centrifugation and Percoll density gradient centrifugation / 实用医学杂志

Objective Percoll density gradient centrifugation and Ficoll-Hypaque density gradient cen-trifugation, which are frequently-used methods for separation of tumor-associated macrophages (TAMs) from solid carcinoma were compared, in order to find an effective way to separate TAMs from colorectal carcinoma (CRC). Furthermore, we studied the best adherence time of separating macrophage among mononuclear cells. Methods specimens were collected from CRC patients , after digesting into single cells , TAMs were separated from the same specimen by 100% Ficoll, 35% percoll and 25% combined with 65% percoll respectively. After these pre-liminary separation, the collected cells were purified a second time by adherence separation. The purity of TAMs were detected by immunofluorescence. Results TAMs purity from Ficoll-Hypaque density gradient centrifugation was 80.18%, statistically higher than that from Percoll density gradient centrifugations (54.33% and 10.93% re-spectively). Conclusion Compared to Percoll density gradient centrifugation, Ficoll-Hypaque density gradient centrifugation is a more effective and simple way to isolate TAMs from colorectal carcinoma , suggesting it can be wildly used in clinical and basic medical research. 2-4 hours is the best adherence time for isolating macrophage.

An optimized extraction protocol of prefrontal cortical and striatal synaptosomes from SHR rat / 中国比较医学杂志

Objective To introduce an improved extraction method of prefrontal cortical and striatal synaptosomes from SHR rat. Methods Synaptosomes were prepared from SHR rat brain tissue by Percoll density gradient centrifugation.Transmission electron microscopy was used to assess the morphology and structural integrity of the synaptosomes.Results The obtained synaptosomes showed oval structures surrounded by an intact membrane.Presynaptic components contained one or more mitochondria and a large number of synaptic vesicles.The synaptic clefts were clearly visible, and prominent part of the characteristic compact structure was clear, complete and with higher electron-density. The synaptosome presynaptic membrane, synaptic cleft, and postsynaptic membrane were well preserved, and the synaptosomes were densely distributed, showing typical morphological characteristics of synaptosomes.Conclusions The results of our study improved the traditional preparation method and provide a less time-consuming, highly productive protocol for preparation of structurally typical and intact synaptosomes, suitable for further research on neuroscience and neurological diseases.

Assessment of swim-up and discontinuous density gradient in sperm sex preselection for bovine embryo production / Avaliação do swim-up e do gradiente descontinuo de densidade na pré-seleção do sexo de espermatozoides na produção de embriões bovinos

The purpose of this work was to associate the modified swim-up method with centrifugation in density gradient for the separation of X-bearing spermatozoa. Sperm viability and integrity were evaluated through the Trypan Blue/Giemsa staining method. Quality control of centrifuged spermatozoa was performed in in vitro produced embryos. The results were validated by the sex ratio of in vitro produced embryos using PCR by Y- specific sequences present in bovine male genomic DNA. After determining genetic sex of in vitro produced embryos, the results showed difference (P<0.05) in deviation of sex ratio when comparing the control group (45.2% females) with the other spermatozoa selection procedures (60.6% females) (P<0.05). The sperm selection methods are capable of selecting X-bearing spermatozoa without compromising the spermatozoa fertility (cleavage and blastocyst rates, 70% and 26%, respectively) and were considered relevant methods to be introduced in bovine in vitro produced embryo programs.

O objetivo do presente trabalho foi associar o método de swim-up modificado à centrifugação em gradiente de densidade para a separação de espermatozoides portadores do cromossomo X. A viabilidade e a integridade espermática foram avaliadas pelo método de coloração Azul de Tripan e Giemsa. O controle de qualidade dos espermatozoides centrifugados foi realizado por meio da produção in vitro de embriões bovinos. Os resultados foram validados pela técnica de PCR para verificar a proporção sexual dos embriões produzidos in vitro, com o uso de sequências Y especificas presente no DNA genômico de machos bovinos. Após determinar o sexo genético dos embriões produzidos in vitro, os resultados não mostraram diferença (P<0,05) no desvio da proporção do sexo quando comparou o grupo controle (45,2% de fêmeas) com os outros processos de seleção de espermatozoides (60,6% de fêmeas) (P<0,05). Os métodos de seleção de espermatozoides são capazes de selecionar espermatozoides portadores do cromossomo X sem comprometer a fertilidade, medida pelas taxas de clivagem e blastocisto de 70% e 26%, respectivamente, e foram considerados métodos de relevância para serem introduzidos nos programas de produção in vitro de embriões bovinos.

Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa

The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized.

Light microscope observation of circulating human lymphocytes cultured in vitro

The purpose of this work was to study the isolation and a light microscopy technique for cultured lymphocytes. Blood samples were obtained by venipuncture with an anticoagulant added and centrifuged in a Percoll density gradient to separate the leukocytes. Lymphocytes were placed in 25 cm ³ tissue culture flasks at 37ºC. After culturing, they were fixed and stained with the methods used for blood smears. Results showed that not all fixing solutions and stains were an equally good choice for cultured lymphocytes.

Os linfócitos são células importantes do sistema imune e têm sido largamente utilizados em estudos morfológicos. Entretanto, a literatura sobre técnicas de preparação dessas células é escassa e antiga, especialmente para linfócitos cultivados in vitro. Portanto, o objetivo desse estudo foi relatar com detalhes as técnicas de isolamento e microscopia de luz de linfócitos mantidos em cultura. Amostras de sangue foram obtidas por punção venosa e centrifugadas em gradiente de densidade de Percoll, para separar os leucócitos. Os linfócitos foram mantidos em frascos de cultura de 25 cm³ a 37ºC. Após a cultura, as células foram fixadas e coradas de acordo com a metodologia utilizada para esfregaços sanguíneos. Nossos resultados mostraram que nem todos os fixadores e corantes utilizados para esfregaços sanguíneos são uma boa escolha para linfócitos cultivados in vitro.

Separación de poblaciones de glóbulos rojos senescentes por gradientes preformados de Percoll / Separation of populations of senescent red blood cells by Percoll performed gradients

Los mecanismos que determinan la senescencia de los eritrocitos han sido extensamente estudiados, sin embargo, no se han logrado conclusiones definitivas debido a la ausencia de una técnica que permita el aislamiento de grupos etáreos bien definidos. Los métodos más comúnmente empleados se basan en el aumento de densidad de los eritrocitos durante el envejecimiento. En este trabajo desarrollamos una técnica para la separación de glóbulos rojos de distintas edades empleando gradientes preformados de Percoll, un polímero sintético con propiedades fisicoquímicas adecuadas para trabajar con células vivas. En las suspensiones eritrocitarias obtenidas se realizaron determinaciones hematológicas, actividades de enzimas antioxidantes y el ensayo de eritrofagocitosis. Los valores de los parámetros hematológicos evaluados fueron significativamente mayores en las suspensiones de glóbulos rojos jóvenes. Las actividades enzimáticas mostraron una disminución de la capacidad antioxidante en las poblaciones de eritrocitos senescentes. Este proceso favorecería la interacción de los hematíes envejecidos con las células fagocíticas, demostrada median­te el ensayo de eritrofagocitosis. Los resultados obtenidos indican que el método de gradientes de Percoll permite una adecuada separación de las suspensiones eritrocitarias de distintas edades, con una eficiencia comparable a la observada en la técnica de centrifugación diferencial considerada de referencia.

The mechanisms that determine the senescence of the erythrocytes have been extensively studied; however. definitive conclusions have not been achieved mainly because of the lack of a technique that allows the isolation of well-defined etarian groups. The methods most commonly used for separating erythrocytes from different ages are based on the increase in density that these cells present during their aging. In the present work we have developed a technique for obtaining red blood cells from different ages using Percoll preformed gradients, a synthetic polymer with adequate physic-chemic properties to work with lives cells. In the erythrocytes suspensions we have made hematological determinations. activities of antioxidants enzymes and the essay of erythrophagocytosis. The values of the hematological parameters were significantly higher in the suspensions of young red blood cells. In the measurements of the enzymatic activity we observed a decrease of the antioxidant capacity in the populations of senescent erythrocytes. This process would promote the interaction between the old erythrocytes and the phagocyte cells, demonstrated by the erythrophagocytosis essay. The results obtained indicate that the method Percoll density gradients allows an appropriate separation of the erythrocytes suspensions of different ages with a comparable efficiency to that observed in the technique differential centrifugation, considered as reference.

A comparative study of Sephadex, glass wool and Percoll separation techniques on sperm quality and IVF results for cryopreserved bovine semen

The aim of this study was to compare the effects of spermatozoa separation techniques on sperm quality and in-vitro fertilization (IVF) results for cryopreserved bovine semen. Sephadex, glass wool and Percoll gradient separation techniques were used for sperm separation and sperm motility, morphology and membrane integrity were evaluated before and after separation. Also, cleavage and blastocyst developmental rate were investigated after IVF with sperm recovered by each separation technique. The motility of samples obtained by the three separation techniques were greater compared to the control samples (p < 0.05). The percentage of spermatozoa with intact plasma-membrane integrity, identified by 6-carboxyfluoresceindiacetate/propidium iodide fluorescent staining and the hypo-osmotic swelling test, was highest in the glass wool filtration samples (p < 0.05). The cleavage and blastocyst rate of total oocytes produced from glass wool filtration samples were also higher than the control and Sephadex filtration samples (p < 0.05), but were not significantly different from Percoll separation samples. However, a significantly greater number of cleaved embryos produced by glass wool filtration developed to blastocyst stage than those produced by Percoll separation (p < 0.05). These results indicate that spermatozoa with good quality can be achieved by these three separation techniques and can be used for bovine IVF. In particular, it suggests that glass wool filtration would be the most effective method of the three for improving sperm quality and embryo production for cryopreserved bovine spermatozoa.

Optimization of Isolation Processing of Monocytes from Peripheral Blood Mononuclear Cells and Differentiation into Dendritic Cells / 대한수혈학회지

BACKGROUND: Rescently, the immunotherapy against infectious disease and cancer is being actively studied, and high yield of pure CD14+ monocytes is a key of concern. In this study, we optimized the percoll gradient method to increase the purity and yield of monocytes from peripheral mononuclear cells. METHODS: We separated mononuclear cells (MNC) from healthy donors, and monocytes from MNC were separated with the various density of percoll gradient. After centrifugation, we determined the most efficient density of the percoll gradient to get the highest yield and purity of monocytes. We also obtained monocytes by the plastic absorption method. Monocytes were differentiated into dendritic cells (DC) and the efficacy of differentiation to DC is confirmed and compared by morphological characteristics and using a flowcytometer. RESULTS: The purity of monocytes was 51.3+/-8.3% by the 35% percoll gradient method and the purity was improved to 82.9+/-4.2% with 100% of yield by repeating the same method. Therefore, the yield of mature dendritic cells was 3.6+/-0.9% of the total input MNC by the 35% percoll repetition method, which was 1.7 times higher than the plastic adherent method (2.1+/-0.5%). CONCLUSION: This study shows a cost-effective method to isolate CD14+ monocytes and these cells demonstrate high differentiation rate to DC. This process will be valuable for obtaining a sufficient number of DC.

Enrichment of dendritic cells precursor from chronic myelogeous leukemia by Percoll density gradients / 吉林大学学报(医学版)

Objective To set up an effective and low-price way for enriching dendritic cells precursor from chronic myelogeous leukemia by Percoll density gradients.Methods Peripheral blood mononuclear cells(PBMCs) were collected by separation through Ficoll-Hypaque,then PBMCs were separated by 55% Percoll gradients. The cell type and DCs expressing CD1a,CD86 were detected in the high-density group(C),low-density group(B) and non-Percoll separation group(A).Results After separation of 55% Percoll,the percentage of promyelocytes and myelocytes in group B was obviously higher than those in group A and group C(P

Neural Stem Cell Harvest and Culture using the High Speed Centrifugation from Rat Brain / 대한마취과학회지

BACKGROUND: During recent two decades of crucial revision of some cornerstone concepts has opened new horizons in neurosciences. Modern basic viewpoints include the idea of high CNS plasticity which means not only rearrangement of neurons and their interconnections, but also the formation of new neural cells in humans and animals during their whole life span. The purpose of this study is to harvest neural stem cell from the adult rat brain using the high speed centrifugation method and study the characteristics of these cell. METHODS: 60 rats (Fisher 344, 150-160 g) brain were saved under inhalation anesthesia and dissect the subventricular zone under the microscope. The brain tissue was digested with enzyme to make a cell suspension. The cell suspension was processed high speed centrifugation to separate the neural stem/progenitor cells according to the buoyancy. After 2 weeks culture, immuno-staining (O4, GFAP, Nestin, beta-tubulin III and DAPI) were performed and replated the cultured cells. RESULTS: The 2 weeks culture cells were positive 92.8% in Nestin, 91.5% in O4 and 87.6% in Gal-C. But only positive 1.4% in beta-tubulin III and 5.5% in GFAP. And replated cell culture shows similar results compared to the primary culture. CONCLUSIONS: With this high speed centrifugation method, authors can harvest neural stem/progenitor cells from the adult rat brain. Although we have many limitations using these cell in clinical trial, but we can afford to next step on neural stem cell research.

The Cell Survival and Differentiation after Transplantation, Which Harvest from Adult Rat Brain by High-speed Centrifugation Method

OBJECTIVE: Many recent reports have shown that the mature mammalian brain harbors multipotent stem cells, rendering the brain capable of generating new neurons and glia throughout life. Harvested stem cells from an adult rat are transplanted in order to evaluate the cell survival and differentiation. METHODS: Using a percoll gradient with a high speed centrifugation method, we isolate neural stem/progenitor cells were isolated from the subventricular zone(SVZ) of a syngeneic adult Fisher 344 rats brain. For 14days expansion, the cultured cells comprised of a heterogeneous population with the majority of cells expressing nestin and/or GFAP. After expanding the SVZ cells in the presence of basic fibroblast growth factor-2, and transplanting then into the hippocampus of normal rats, the survival and differentiation of those cells were examined. For transplantation, the cultured cells were labeled with BrdU two days prior to use. In order to test their survival, the cells were transplanted into the dorsal hippocampus of normal adult Fisher 344 rats. RESULTS: The preliminary data showed that at 7days after transplantation, BrdU+ transplanted cells were observed around the injection deposition sites. Immuno-fluorescent microscopy revealed that the cells co-expressed BrdU+ and neuronal marker beta-tubulin III. CONCLUSION: The data demonstrate that the in vitro expanded SVZ cells can survive in a heterotypic environment and develop a neuronal phenotype in the neurogenic region. However more research will be needed to examine the longer survival time points and quantifying the differentiation in the transplanted cells in an injured brain environment.

Hypoosmotic swelling test of sperm supplemented with pentoxifylline after preparation by two-layer percoll gradient method.

The aim of this study was to compare the percentage of sperm tail membrane swelling under hypoosmotic conditions with those with and without pentoxifylline supplements in sperm prepared by the two-layer Percoll gradient method. Twenty five normal semen samples were collected from male partners of infertile couples attending the Infretility Clinic at Siriraj Hospital. After the process of sperm preparation by the two-layer Percoll gradient method, the final samples were divided into 2 tubes, 0.5 ml was added into one tube and another tube was kept as control. The hypoosmotic swelling test was performed on both specimens. The percentage of swollen spermatozoa in the pentoxifylline supplement group was significantly higher than the control group (82.8 + 7.7 vs 70.8 + 12.7; p < 0.00). It was concluded that the addition of pentoxifylline to the sperm prepared by the two- layer Percoll gradient method can enhance the sperm membrane integrity, and it may be beneficial to add pentoxifylline to sperm preparation for use in IUI or IVF.

Effects of IGF (Insulin-like growth factor) on sub-populated articular chondrocytes by Percoll density gradient / 대한정형외과연구학회지

PURPOSE: Articular chondrocytes have been known to have heterogeneity in articular cartilage. The different responses of chondrocytes to various cytokines and growth factors have been reported. These variations are likely a result of metabolic differences among the cell populations. We used the Percoll density gradient method to separate chondrocytes from articular cartilage into distinct subpopulations. Several growth factors are known to enhance the synthesis of cartilage matrix. In particular, IGF has specific anabolic effects. Addition of IGF to chondrocytes increased the synthesis of proteoglycans and collagen type-II while inhibiting the degradation and release of proteoglycans. MATERIALS AND METHODS: Chondrocytes were isolated from rabbit knee articular cartilage by collagenase digestion. In brief, male rabbits weighing 250g were euthanized by injecting an overdose of Nembutal, and nonfibrillated articular cartilage of the knee was removed by sterile dissection. Isotonic Percoll was mixed with 10x PBS to give a 60% stock solution. This was further diluted with PBS to give Percoll concentrations of 10, 20, 30, 40, 50, and 60%. RT-PCR, western blot analysis, immunocytochemistry, and immunohistochemistry were done for examination of collagen type II and aggrecan as the specific marker of extracellular matrix and proteoglycan synthesis on cultured chondrocytes. RESULTS: The sub-populated cells were proliferated variously. On the other hand, the addition of IGF to the sub-populated cells increased the proliferation in all fractions. Also the expression of collagen type-II and TIMP-2 was increased by IGF treatment. After alginate culture, collagen type-II expression was not significantly different between the IGF treated and the control groups in high density fractions. However, the addition of IGF to chondrocytes increased the expression of collagen type-II in low density fractions. The expression of collagen type-II after IGF addition was decreased in monolayer culture while it was increased in alginate culture. CONCLUSION: The effects of IGF are various among the subpopulated chondrocytes. These results will provide useful information for the separation of articular chondrocytes with an active metabolic activity and extracellular matrix for the investigation of the pathogenesis of articular cartilage.

Induction of acrosome reaction by calcium ionophore A23187 in sperm separated by two-layer percoll gradient method.

The aim of this study was to compare thepercentages of sperm with an acrosome reaction between those with and without calcium ionophore A23187 induction after two-layer Percoll gradient separation. Thirty normal semen samples were obtained from the male partners of infertile couples attending the Infertility Clinic at Siriraj Hospital. After the process of sperm separation by two-layer Percoll gradient technique, the final samples samples were divided into 2 portions. An aliquot of 10 ตM of calcium ionophore A23187 was added to one portion to induce an acrosome reaction, while the other portion was used as a control. Fluorescein isothiocyanate-conjugated Pisum sativam agglutinin (FITC-PSA) staining was performed on both specimens and the acrosome reated-sperm were evaluated. The percentage of acrosome-reated sperm in the calcium ionophore A23187 induced group was significantly higher than those of the control group (24.8+6.6vs 15.4+6.0;p < 0.001). It is concluded that calcium ionophore can significantly induce an acrosome reaction on sperm separated by two-layer Percoll gradient technique, and it may be beneficial to add calcium ionophore A23187 to sperm preparation for use in IUI or IVF.

Sperm motility and morphology after preparation using the percoll gradient method compared with the IxaPrep gradient method.

In order to compare the Percell gradient and IxaPrep gradient methods, the percentage of progressively motile sperm and the percentage of sperm with normal morphology were examined. Thirty five normal semen sample were collected from the male partners of infertile couples attending the Infertility Clinic. The samples were divided into two fractions of 1 ml each. Both fractions were processed using the Percoll gradient and IxaPrep gradient methods, and sperm motility and normal morphology were evaluated. The percentages of spermatozoa that showed progressive motility and normal morphology from the sperm preparation using the IxaPrep gradient method were significantly higher than those prepared by the Percoll gradient method (77.7 + 12.0 vs 73.7 + 12.3 and 64.4 + 15.1 vs 61.1 + 13.3 respectively ; p<0.05). It was concluded that sperm preparation using IxaPrep gradient method showed better sperm quality with respect to progressive motility and normal morphology than those using the Percoll gradient method, The IxaPrep gradient method can be considered as an alternative to the Percoll gradient for sperm preparation.