No abstract available.
Centrifugation ; Weightlessness

PURPOSE: The purpose of this study was to observe the effect of IFN- and PGE2 on TNF- production by human peripheral mononuclear cells(PBMC) that were stimulated with LPS. METHODS: PBMC were separated by Ficoll-Hypaque gradient centrifugation from human peripheral venous blood and were incubated for 72 hours with or without LPS, IFN- , PGE2, and indomethacin according to various conditions. TNF- activity of PBMC culture supernatants was assayed by determining the cytotoxicity against L929 cells. RESULTS: 1) The production of TNF- by PBMC in response to LPS reached the highest level between 8-24 hours and returned to control level by 72 hours. 2) When IFN- was added together with LPS, LPS-induced TNF- production was enhanced and prolonged, which was more remarkable when IFN- was added at higher concentration or earlier than LPS. 3) When PGE2 was added together with LPS, LPS-induced TNF- production was suppressed. 4) The addition of IFN-gamma reduced the suppressive effect of PGE2 on LPS-induced TNF- production. 5) Enough amount of indomethacin enhanced production of TNF- by LPS. CONCLUSIONS: IFN-gamma increased and PGE2 decreased the production of TNF- by PBMC which were stimulated with LPS. And PBMC which were pretreated with IFN-gamma were resistent to the suppressive effect of PGE2.
Centrifugation ; Dinoprostone* ; Humans* ; Indomethacin

No abstract available.
Centrifugation ; Stem Cells

No abstract available.
Centrifugation ; Stem Cells

Background: In Vietnam, the proportion infertile couples was about 7-10% of reproductive couples. Assisted reproductive technologies appeared and expanded rapidly. In 1970, sperm preparation techniques were found out, artificial insemination became widespread. Sperm preparation stage is very important in assisted reproductive techniques and increasingly improved. Objectives: To compare the efficiency of two sperm preparation techniques: swim \ufffd?up and discontinuous density gradient. Subjects and method: This was a cross-sectional described study included 30 normal semen samples were chosen based on WHO 1999 criteria. We examined sperm vitality, concentration, motility, morphology before and after applied these techniques. Results: Both procedures resulted in a significant higher percentage of vitality, motility, morphology compared with the original semen sample (p<0.01), but the concentration reduced approximately 5 times from whole semen to sediment when swim \ufffd?up was used and 3 times with density gradient, the difference was statically significant (p< 0.01). Conclusion: Normal semen should be prepared by these method. But in oligozoospermic man, to obtain a higher concentration of sperm, semen should be prepared by density gradient method.
Spermatozoa ; Centrifugation ; Density Gradient ;

No abstract available.
Centrifugation, Density Gradient* ; Humans* ; Spermatozoa*

PURPOSE: In the autologous fat injection, the centrifugation is useful for the refinement of harvested fat. As it can be an injury to the fat cell, we studied the fat cell viability with the change of centrifugation velocity and centrifugation time in order to get the limits of centrifugation velocity and centrifugation time. METHODS: We used the Colman System in 8 patients. We handled the control group with no centrifugation, group I with the centrifugation with 1500rpm for 1 minute, group II with 1500 rpm for 3 minutes, group III with 1500rpm for 5 minutes, group IV with 3000rpm for 1 minute, group V with 3000rpm for 3 minutes, group VI with 3000rpm for 5 minutes, group VII with 5000rpm for 1 minute, group VIII with 5000rpm for 3 minutes, group IX with 5000rpm for 5 minutes. We used the collagenase to separate the fat tissue. We had evaluated the fat cell viability by checking survival cell counts. RESULTS: There was no significance in group I, II, IV, V, but there was significant difference in group III, VI, VII, VIII, IX. CONCLUSION: The centrifugation with 3000rpm for 3 minutes is recommendable.
Adipocytes* ; Cell Count ; Centrifugation* ; Collagenases ; Humans

BACKGROUND: Reconstructed human epidermal culture skin models have been developed for cosmetic and pharmaceutical research. OBJECTIVE: This study evaluated the total and carboxyl esterase activities (i.e., K(m) and V(max), respectively) and localization in two reconstructed human epidermal culture skin models (LabCyte EPI-MODEL [Japan Tissue Engineering] and EpiDerm [MatTek/Kurabo]). The usefulness of the reconstruction cultured epidermis was also verified by comparison with human and rat epidermis. METHODS: Homogenized epidermal samples were fractioned by centrifugation. p-nitrophenyl acetate and 4-methylumbelliferyl acetate were used as substrates of total esterase and carboxyl esterase, respectively. RESULTS: Total and carboxyl esterase activities were present in the reconstructed human epidermal culture skin models and were localized in the cytosol. Moreover, the activities and localization were the same as those in human and rat epidermis. CONCLUSION: LabCyte EPI-MODEL and EpiDerm are potentially useful for esterase activity prediction in human epidermis.
Animals ; Centrifugation ; Cytosol ; Epidermis ; Humans ; Rats ; Skin*

Melanosomes were isolated from the human hair by graded centrifugation and identified by transmission and scanning electron microscopic examination. Melanosomes were separated from the keratinous structures by treating with strong NaOH solution for 15 hours. The keratinous structures were removed by centrifugation ai 2,500xg and 3,500xg for 10 minutes respectively at 0 ℃. The isolated melanosomes were collected by centrifugation at 7,800xg at 0 ℃. Scanning electron microscopic examination made it possible to evaluate the global structure of purified melanosomes.
Centrifugation ; Hair* ; Humans* ; Melanosomes* ; Microscopy, Electron, Scanning

BACKGROUND: The aim of this study was to investigate alterations in homocysteine levels with delays in the initiation time of centrifugation. Attempts were made to improve the processing of samples by analyzing the homocysteine levels of patients from a health promotion center, where delays in the initiation of sample centrifugation were expected because of the nature of the workload and operational procedures. METHODS: Forty healthy adults were selected for the measurement of homocysteine levels. The two samples those were obtained from each individual simultaneously and separately were designated as group A (centrifugation initiation time < or =20 minutes after blood sampling) and group B (> or =2 hours). The degree of deviation from the homocysteine reference interval was also evaluated with samples from 1,134 adults who had medical check-up at a health promotion center from August 1, 2009 to July 31, 2010. RESULTS: The mean serum homocysteine level in group B was significantly higher than that of group A (12.4 vs. 10.6 micromol/L, P<0.0001). Homocysteine level increased with a mean of 19.4% when the initiation of centrifugation was delayed over 2 hours. In the 1,134 adults who had medical check-up, the numbers outside the reference interval were 334 (29.5%). Abnormal samples with homocysteine levels out of the reference interval were reduced to about 7% in July 2011 through improving sample processing to minimize delays in centrifugation initiation time. CONCLUSIONS: Homocysteine levels rapidly increase as blood sample centrifugation is delayed. Therefore, in order to provide accurate test results immediate centrifugation of blood samples is critical.
Adult ; Centrifugation ; Health Promotion ; Homocysteine ; Humans