Detection and characterization of Bacillus cereus isolated from the dialysis fluid

ABSTRACT In this study, B. cereus was detected in dialysis fluids within international parameters (ultrapure - maximum limit of 0.1 CFU/mL for heterotrophic bacteria count) by analyzing the pellet obtained through the centrifugation method. We also investigated the ability of the B. cereus isolate to form a biofilm at different temperatures, the production of virulence factors, and the susceptibility to commercial antimicrobial agents. This study demonstrated a high ability of B. cereus to persist in the hemodialysis system, which can be explained by its broad ability to produce a biofilm at 25 °C, its relevant production of virulence factors, such as β-hemolysin, lecithinase and cereulide, and its important resistance pattern to antimicrobial drugs. In conclusion, these new findings expand the understanding that this microorganism should not be neglected and new methods for tracking it should be considered.

Viabilidade das células-tronco mesenquimais do tecido adiposo proveniente de lipoaspirado humano / Viability of mesenchymal stem cells of adipose tissue from human liposuction

Introdução: A lipoenxertia é uma alternativa com importante aplicabilidade para reconstrução de mama e/ou correções de assimetrias decorrentes do tratamento oncológico. Esta técnica consiste na transferência de gordura autóloga, cujo estroma contém células-tronco derivadas do tecido adiposo que tem capacidade de diferenciar-se em toda a linhagem mesodermal. Para o preparo do tecido adiposo, Coleman fundamentou a centrifugação, de material aspirado por seringa, em 3000 rotações por minuto (rpm) durante 3 minutos. Contudo, estudos questionam se velocidades menores de centrifugação poderiam ser menos deletérias para viabilidade celular. Métodos: Foi realizado um estudo experimental, onde foram avaliadas as células adiposas de seis pacientes; a partir de 60mL de lipoaspirado de cada um. A amostra coletada foi fracionada em quatro tubos, e submetidos a diferentes protocolos, decantação e centrifugação nas velocidades 500, 1000 e 3000rpm por 3 minutos. Após as amostras foram processadas com colagenase IA por 30 min, submetidas ao cultivo celular por 24 horas e realizado a análise da viabilidade celular. Os resultados foram tabulados e analisados pelo teste ANOVA utilizando os programas Graphpad Prism 6.0® e SAS®. Resultados: A viabilidade celular foi maior na amostra celular centrifugada a 3000rpm e menor na amostra decantada. A coloração com Giemsa indicou manutenção da morfologia celular entre as amostras. Conclusão: As células centrifugadas na velocidade de 3000rpm apresentaram maior viabilidade celular. A centrifugação foi efetiva na compactação do tecido e eliminação de resíduos indesejados (sangue e óleo residual).

Introduction: Lipografting is an alternative with important applicability for breast reconstruction and/or corrections of asymmetries resulting from cancer treatment. This technique consists of autologous fat transfer, whose stroma contains stem cells derived from adipose tissue that can differentiate itself throughout the mesodermal lineage. For adipose tissue preparation, Coleman-based centrifugation of syringe-aspirated material at 3000 revolutions per minute (rpm) for 3 minutes. However, studies question whether lower centrifugation speeds could be less harmful to cell viability. Methods: An experimental study was conducted to evaluate the adipose cells of six patients; from 60mL of liposuction of each one. The sample collected was fractionated into four tubes and submitted to different protocols, decanting and centrifugation at speeds 500, 1000, and 3000rpm for 3 minutes. Afterward, the samples were processed with collagenase IA for 30 min, submitted to cell culture for 24 hours, and a cell viability analysis. The results were tabulated and analyzed by the ANOVA test using the Graphpad Prism 6.0® and SAS®. Results: Cell viability was higher in the cell sample centrifuged at 3000rpm and lower in the decanted sample. Giemsa staining indicated maintenance of cell morphology on the samples. Conclusion: Centrifuged cells at a speed of 3000rpm showed higher cell viability. Centrifugation was effective in compacting tissue and eliminating unwanted waste (blood and residual oil).

Study on purification of celandine extract from Tong'an Injection / 中草药

Objective: To optimize the purification process of celandine in Celandine Alkali from Tong'an Injection, and to improve the content of celandine in Celandine Alkali extract. Methods: In order to select the best way to separate celandine acid liquid, a study was carried out in three different ways of separation such as plate straight association-like centrifuge, high speed tubular centrifuge, and disc centrifuge; We investigated the dissolving effect caused by different pH values of hydrochloric acid to celandine dry extract; Three separation methods on celandine acidic lysate were investigated to choose the best, such as vacuum filtration, high-speed centrifuge tube, and flat direct-coupled centrifugal. Celandine Alkali transfer rate, and dry paste rate were as used evaluation indexes, so as to determine the feasible celandine refining purification process. Results: It was the best way to separate celandine acid liquid by using disccentrifuge; Hydrochloric acid could have the best dissolving effect on celandine dry extract when the pH values were 3-4, and the transfer rate of chelidonine was also the highest; High-speed tubular centrifuge was the best separation method for the celandine acidic dissolution liquid. Conclusion: The optimized process is simple, stable and viable, and it could be used for the preparation of qualified celandine intermediates.

Effect of Parasep? feces centrifuge tube method on detecting schistosome eggs / 中国血吸虫病防治杂志

Objective To evaluate the effect of the Parasep? feces centrifuge tube method on detecting schistosome eggs. Methods A total of 803 residents aged from 6-65 years were selected in 2 schistosomiasis endemic villages Jiangling Coun-ty Hubei Province and their stool samples were collected and detected parallelly by the Kato-Katz technique nylon silk egg hatching method and Parasep? feces centrifuge tube method at the same time. Results Among the 803 people 15 cases were found of schistosome egg positive and the positive rate was 1.87%. The positive rates of the Kato-Katz technique nylon silk egg hatching method and Parasep? feces centrifuge tube method were 0.75% 1.49% and 1.12% respectively. The schistosome eggs got with the Parasep? feces centrifuge tube method were clear and easy to identify. Conclusion In low endemic areas of schistosomiasis the Parasep? feces centrifuge tube method can be used as schistosomiasis japonica etiology diagnosis method.

Estudo comparativo entre metodologias de triagem para detecção de hemoglobina S em bancos de sangue / Comparative study between methods of screening for detection of hemoglobin S in the blood banks

INTRODUÇÃO: O traço falciforme é a presença em heterozigose da hemoglobina S (HbS). A partir de junho de 2004, por meio da RDC 153/04, tornou-se obrigatória a triagem de hemoglobinas anormais em doadores de sangue. OBJETIVO: O objetivo deste estudo foi a comparação de diferentes metodologias de triagem utilizadas nos bancos de sangue para a detecção da HbS. Material e método: No período de abril de 2007 a abril de 2008, foram realizados três métodos de detecção de HbS em 4.108 doadores de sangue aptos que se apresentaram ao banco de sangue do Hospital Universitário de Santa Maria (HUSM). O estudo comparativo entre as metodologias incluiu os testes de solubilidade e de gel-centrifugação, tendo como referência de positividade a presença de HbS na eletroforese de hemoglobina. RESULTADOS: Dos 4.108 doadores estudados, 23 (0,56 por cento) apresentaram resultado positivo para HbS e dois (0,05 por cento) para HbC. Das amostras positivas para HbS detectadas por eletroforese qualitativa, 22 (95,6 por cento) foram detectadas pelo teste de solubilidade e 20 (86,9 por cento) pelo de gel-centrifugação. CONCLUSÃO: A eletroforese de hemoglobinas representou a melhor metodologia na identificação de hemoglobinas variantes e, portanto, deve ser valorizada quando se trata de diagnóstico para triagens em bancos de sangue pelo seu grau de sensibilidade, minimizando ao máximo os resultados falsos negativos e garantindo a qualidade do sangue que estará sendo utilizado.

INTRODUCTION: The sickle cell trait is the presence of hemoglobin S (HbS) in heterozygosity. According to RDC regulation 153/04, abnormal hemoglobin screening has become mandatory in blood donation samples since June 2004. OBJECTIVE: The aim of this study was to compare different screening methods used in blood banks for HbS detection. Material and method: From April 2007 to April 2008, three HbS detection methods were applied in 4,108 suitable blood samples from the blood bank of the University Hospital of Santa Maria (HUSM). The comparative study among the methods comprised solubility tests and gel-centrifuge (ID-HbS). Furthermore, the positivity reference was the presence of HbS on hemoglobin electrophoresis. RESULTS: Twenty-three (0.56 percent) out of 4,108 samples showed positivity for HbS and two (0.05 percent) showed positivity for HbC. Twenty-two (95.6 percent) out of 23 HbS positive samples determined through qualitative electrophoresis were detected by solubility test and 20 (86.9 percent) were detected by gel-centrifugation test. CONCLUSION: Hemoglobin electrophoresis proved the best method in the identification of hemoglobin variants and, therefore, worthwhile when it comes to diagnostic screening in blood banks due to its high sensitivity, which keeps false-negative results to a minimum and ensures blood quality.

The Study of Characteristics of Acellular Porcine Cornea Using Freezing-Thawing-Centrifugation

PURPOSE: To develop a new decellularization technique of porcine cornea using freezing-thawing-centrifugation (FTC) and to examine the characteristics of acellular porcine cornea (APC) for xenograft material. METHODS: Two-hundred micrometer thickness porcine corneas were decellularized with DNase/RNase, followed by 3 freezing-thawing-centrifugations (FTC, group 1), lyophilized FTC-APC (group 2), and chemical enzyme treated APC (CE-APC, group 3). Histologic evaluation to examine cells and collagen matrix, comparison of transparency, and cultivation to determine the viability of stromal cells was performed in fresh porcine cornea and 3 experimental groups. RESULTS: Decellularization occurred successfully in all experimental groups. Decellularization was confirmed by H&E staining and cultivation. Transparency of group 1 was similar to the normal porcine cornea but transparency of group 2 and group 3 was decreased. Collagen fibers of CE-APC (group 3) were not as well arrayed as FTC-APC (group 2). CONCLUSIONS: Acellularity of porcine cornea was successfully achieved by the FTC method with preservation of the cornea stroma. Novel decellularized porcine cornea can be considered as xenogeneic material for corneal transplantation.

The influence of centrifugal speed and time on TEM sample preparation of culture cell / 重庆医科大学学报

Objective:To investigate the influences of different centrifugal conditions on the ultrastructure of cultured cells in the digestion centrifugation to find out the best speed and time of centrifugation.Methods:The cultured cells after digested,were divided into groups according to different digestion centrifuge speed and time,and the changes of cell morphology in each group at different centrifugation time and speed were compared under transmission electron microscope.Results:Enough cells could mot be collected with the centrifuge speed less than 800 r/min,8 min.The cells were deformed due to extrusion or the cytoplasm was torn with the speed of 2 000 r/min,15 min.With the speed of 800～1 500 r/min,8～15 min,it was more proper to prepare samples and preserve cell ultrastructure.Conclusion:It is ideal to prepare TEM samples of cultured cells by using the cells being digested and centrifuged with speed at 800 ~1 500 r/min and time of 8~15 minutes.

The results of studying procedure to reduce erythrocytes from cord blood using to long-term storage of CD34 cells

Background: The reduction of erythrocytes from cord blood is very need for long - term storage of C034 cells for transplantation. Reduced erythrocyte will reduces preservative blood volume, preservatives and freely HST when defrosting, so stem cells are better protected. Objectives: To study selection of the best centrifugal procedure to reduce maximal erythrocytes and lose minimal C034 cells from cord blood. Subjects and methods: 20 blood samples selected from 60 cord blood units was used for this study. The study was carried out through two steps. In the first step, the centrifugal speed was fixed and the centrifugal time was changed.In the second step, the centrifugal time was fixed, the centrifugal speed was changed. From collected results the best appropriate procedure to reduce erythrocytes from cord blood have been selected. Results: The procedure of gradient centrifuge with speed of 500g in 6 minutes isolated> 50% of erythrocytes, kept > 84% of CD34 cells and then centrifuge of 1000 g in 10 minutes reduced about 40% of volume of nuclear cell - suspension. Conclusion: The procedure can use for preparation of stem cell suspension from cord blood to storage in nitrogen liquid. \r\n', u'\r\n', u'

Effects of +3Gz, +2Gz, and -1Gz on Intraocular Pressure (IOP)

BACKGROUND: Pilots of tactical aircraft are exposed to sustained accelerations ranging from -1Gz to +9Gz. Pilots are routinely exposed to +2 and +3Gz. It has been known that chronic elevations in intraocular pressure (IOP) are associated with the development of visual impairments, which could lead to a damage of optic nerve fibers with subsequent visual field defects. This IOP alteration may be caused by body fluid shifts resulting from acceleration forces. The IOP, theoretically, will be increased under negative Gz acceleration resulting from cephalad shift of body fluid and should not be increased under positive Gz accelerations according to hydrostatic column effects. However, there is little research regarding intraocular pressure changes during acceleration forces. Therefore, this study was designed to evaluate IOP effects of exposure to +2 Gz, +3 Gz, and -1Gz environments. METHODS: Intraocular pressures were measured on 3 subjects (2 men and 1 woman) during +2Gz, +3Gz, and -1Gz centrifuge exposures on the Dynamic Environment Simulator (DES) centrifuge. Two IOP measurements were obtained with the Ocuton S self-tonometer at +1Gz (Pre-baseline), +2Gz, +3Gz, -1Gz, and again at +1Gz (Post-baseline). A total 60 measures were obtained under +1Gz, + 2Gz, + 3Gz, and -1Gz. RESULTS: The result showed that there was a significant difference in the means for percent change of IOP from pre-baseline to +2Gz, +3Gz, and -1Gz. The mean IOP increased by 19.5% during +2Gz acceleration when compared to pre-baseline (16.3 vs. 19.5 mmHg, P=0.0001). The mean IOP of +3Gz level was 30.2% higher than that of pre-baseline level (16.3 vs. 21.2 mmHg, P=0.0001). The mean of IOP increased 127.9% during -1Gz when compared to baseline values (16.3 vs. 37.1 mmHg, P=0.0001). However, there was no significant difference in IOP between pre-baseline and post-baseline (16.3 vs. 16.0 mmHg, P=0.4261). There were significant differences, in percent change from pre-baseline, among the +2Gz, +3Gz, and -1Gz conditions {F (2,18)=152.05, P=0.0001}. There was a significant difference in the means of IOP at +2Gz and -1Gz (19.5 vs. 37.1 mmHg, P=0.0001). There was a significant difference in the means of IOP at +3Gz and -1Gz (21.2 vs. 37.1 mmHg, P=0.0001). There was a marginal significance in the means of IOP at +2Gz and +3Gz (P=0.0321). CONCLUSION: The conclusion of this study was that significant increases in IOP were found during +2Gz and +3Gz as well as -1Gz when compared to pre-baseline IOP values. These findings suggest that a rise of IOP during +2Gz and +3Gz cannot be explained by the hydrostatic column effects that are associated with acceleration exposure.

Differential expression of genes in the rat heart during centrifuge training / 中国病理生理杂志

AIM: Centrifuge training can improve forward acceleration (+Gz) endurance. This study was to analyzed the gene expression of rat heart affected by centrifuge, and to research the molecular mechanism of improving +Gz endurance by centrifuge training. METHODS: Differential expressed genes between high+Gz endurance (+16Gz) rats, of test group after trained 12 d and control were screened using suppression subtractive hybridization (SSH) and dot blot hybridization. The obtained expressed sequence tags (ESTs)were used as probes to perform RNA slot hybridization with heart total RNA isolated from each gruop of centrifuge training and high+Gz endurance and low+Gz endurance (+12Gz) rats, respectively. The positive ESTs were sequenced and analyzed using BLAST(nr) at NCBI.RESULTS: Three down-regulated ESTs were obtained from heart samples, all of them are new, and their expression levels were decreasing during centrifuge training. CONCLUSION: Centrifuge training can significantly affect the special gene expressions of rat heart, and the expression changes of these genes may be ralated to the mechainism that +Gz endurance can be improved by centrifuge training.

THE ANALYSIS ON SEDIMENTATION COEFFICIENT OF ALFALFA MOSAIC VIRUS / 微生物学通报

The physical and chemical properties of alfalfa mosaic virus from white clover have been studied by analytical ultra-centrifuge. The results showed that this virus sample contains five different components which possess the S_(20) values of 98s, 82s, 72s, 65s, and 36s respectively. While measured the S values we have used schlieren light system by using UV system as control. The twice changed speed method also has been used to measure the S values at different concentration of samples under different ion strength.

Conversion of refrigeration centrifuge into clinical multi-use centrifuge / 医疗卫生装备

This paper introduces the conversion of a refrigeration centrifuge into a clinical multi-use centrifuge. The method and procedure are mainly discussed.

The development of the measuring equipment for rotating speed and temperature of the centrifuge / 医疗卫生装备

To measure the rotating speed and temperature of the centrifuge, an equipment and method are developed in this paper. They prove to meet the requirements of measuring. The equipment and method can be used to measure the rotating speed or temperature of the operating centrifuge easily and accurately. That is also the main excellence of them.