A quick method for the preparation of stable DNP red cell conjugates

Another procedure for preparing dinitrophenyl (DNP) sheep erythrocytes (SRBC) using the DNP-alanylglycylglycyl hapten has been developed. These DNP-SRBC also are stable for as long as 1 month, but the conjugation procedure is much simpler to carry out than the previously reported method.     

悬浮介质对红细胞变形性测量的影响

本文研究了悬浮介质粘度对激光衍射仪测量红细胞变形性的影响,所得结果表明:(1)在一定切变率下(800s~(-1),480s~(-1))DI-η曲线的高粘度区与前人(如D.R.Morris等)一致,但低粘度区有一极小值。(2)即使在相同切应力下,DI-η曲线相当复杂,特别是在低切应力水平更是如此,但是当η≥15cP时,DI趋于定值。(3)利用红细胞在切变流场中旋转、取向与变形时间尺度上的明显差异,可以把红细胞旋转取向的贡献从变形中区分出来。实验结果表明,低粘度DI-η复杂行为主要起因于红细胞的旋转和取向。文中对实验观测到的现象进行了讨论。     

Detection of antigen specific rosette formation with the FACS

Donors previously sensitized to conventional antigens PPD and KLH were evaluated for their antigen binding responses, utilizing a rosette forming technique with antigen-conjugated autologous erythrocytes. Reactivity is directly correlated with prior sensitization. Furthermore, antigen specificity is suggested by inhibition of rosette formation by prior incubation with the relevant antigen. The frequency of RFCs detected cytofluorometrically was compared with conventional fluorescent microscopy determinations. RFCs detected in this manner were identified as antibody armed monocytes by cell depletion and histochemical studies. The usefulness of the rosette forming technique for the routine evaluation of donor immunity is discussed.     

脑血栓形成患者的红细胞变形性测定

采用国产ＢＬ８８－Ｃ型激光衍射红细胞变形仪，对３４例脑血栓形成急性期患者进行红细胞变形性的测定，并与同期住院的３４例上呼吸道感染和周围神经病患者进行对比，结果表明，急性脑血栓形成患者红细胞变形指数（ＤＩ）较对照组明显降低，以低剪切力时尤为明显，说明红细胞变形性降低是脑血栓形成的原因之一，并提示随年龄的增加，急性脑血栓形成的发病率也在增加。     

In vitro selection of murine antigen-specific T-lymphocytes. I. Description of selection procedure

Enrichment of antigen-responsive murine T-lymphocytes was achieved by two in vitro procedures through the preferential adherence of the antigen-specific cells to the antigen-pulsed macrophages and their consequent multiplication. The first procedure involved the addition of column-purified T-enriched lymph node lymphocytes from immunized mice to a monolayer of antigen-pulsed adherent spleen cells from non-primed syngeneic donors. Lymphocytes which failed to adhere to the antigen-pulsed monolayer were removed after 4 h of incubation. The adherent cells were cultured for a week and the lymphocytes obtained after that period from the selection plate were highly responsive to the antigen for which they were selected and for a T-cell mitogen (Con A). On the other hand, these selected cells demonstrated little or no response to other antigens, to which the original donor of the lymphocytes was immune, and to a B-cell mitogen (LPS). The same preferential response to the selecting antigen and T-cell mitogen was obtained in lymphocytes enriched in the alternate procedures on ‘supernatant cultures’. The enriched population from ‘supernatant culture’ was derived from cells that did not adhere to the antigen-pulsed monolayers during 4 h of incubation. The non-adherent lymphocytes which still contained antigen-specific lymphocytes were transferred to a fresh monolayer of antigen-pulsed adherent spleen cells to be grown for a week in culture. The improvement in the response to the selecting antigen and the decreased reaction to other immunizing antigens show that the cells harvested from either ‘selected’ or ‘supernatant’ cultures were enriched for a given antigen — the selecting antigen. In most individual experiments the enrichment was better in the selected cultures.The enrichment procedures were dependent upon effective antigen presentation to the lymphocytes. Spleen cells from mineral oil-injected mice, which are the most effective antigen-presenting cells, formed the most efficient monolayers for the enrichment of the antigen-specific lymphocytes, both in the ‘selected’ and ‘supernatant’ cultures.     

The definition of an MB related specificity by a monoclonal antibody

A number of monoclonal antibodies have been described that react with monomorphic and polymorphic Ia-like specificities on human B cells, but it is not clear whether these react with HLA-DR encoded molecules or with the products of other closely linked genes within the MHC, such as MB, MT, or DC 1 antigens. A monoclonal antibody is described herein (MC-26.1) which detects a new Ia-like specificity as shown by B-cell reactivity, chemistry, family studies, including recombinant family and coprecipitation studies. The latter studies showed that specificity detected by the MC-26.1 antibody coprecipitated with determinants detected by conventional anti-MB3 and MT3, but not with HLA-DR4 antisera. The determinant was polymorphic but not related to any of the known MB or MT specificities. However, cross-reactions were demonstrated by the variability of reaction on different individuals. Coprecipitation studies indicate that the antigen defined by MC-26.1 coprecipitates with MB and MT specificities suggesting that the antibody defines a new specificity on the MB3 and MT3 molecules.     

Assessment of aquo-ethanolic extract of Camellia sinensis against Carbapenem Resistant Escherichia coli: In Vivo Trials in a Murine Model

The prevalence of Carbapenem Resistant Escherichia coli (CRE) has increased considerably during the last decade, which can be ascribed to relative scarcity of effective non toxic antimicrobial agents. The present study was conducted to evaluate the antimicrobial activity of aquo-ethanolic (1:1) extract of leaves of Camellia sinensis (PTRC-31911-A) against Carbapenem Resistant Escherichia coli at preclinical level using peritonitis infection model in Sprague Dawley rats. Efficacy analysis of PTRC-31911-A involved enumeration of CRE colonies in blood and urine samples of test animals for a period of 5 days from infection. A reduction in microbial count of biological fluids was considered as the primary endpoint of the selected murine model. Physical, biochemical, hematological and histological indices of toxicity were employed as secondary relative indicators of the induced disease. Physical manifestations of infected rats included significantly high body temperature (Temp_Infected = 103.18 °F, ∼5% increase) and noteworthy reduction in weight (Weight_Infected = 126.83 g, ∼15% decrease) as compared to control. Significant (P < 0.05) increase in total white blood cells, eosinophil and monocyte counts as well as a significant decrease (P < 0.05) in erythrocytes count, hematocrit volume, red blood cell distribution width and hemoglobin concentration were observed in the infected group as compared to the control group. Furthermore, noteworthy increase in liver and kidney function test parameters were observed in case of infected groups. All the hematological and biochemical parameters were found to be within optimum range in case of treatment group, indicating restoration of homeostasis. Histopathological studies also presented symptoms of hemorrhage and glomerular damage with structural distortion in glomerular capillary loops of infected groups, which were later recovered in treated groups, indicating the nephro-protective potential of PTRC-31911-A. The study clearly points out that Camellia sinensis extract (PTRC-31911-A; single dose of 5 mg/Kg bwt; oral, + 24 h) is highly effective against Carbapenem Resistant Escherichia coli owing mainly to the presence of flavonoids and polyphenolic compounds, identified by LCMS. Ongoing studies are expected to further unravel the mechanism of action and bioactivity determinants of this broad spectrum plant extract.     

氟、铝联合对红细胞膜三磷酸腺苷酶活性的影响

目的研究氟铝联合对红细胞膜酶活力的影响.方法制备红细胞膜,体外染氟、铝,钼铵酸法测定磷,计算酶活力.结果铝(1mmol/L、40mmol/L)可导致红细胞膜钠、钾三磷酸腺苷酶(Na -K -ATPase)、钙三磷酸腺苷酶(Ca2 -ATPase)活力下降,在研究剂量范围内加入不同剂量的氟(0.1mol/L、4.4mol/L)并未对铝的损伤作用产生明显的影响.结论铝可导致红细胞膜损伤,但本研究剂量的氟、铝不存在拮抗或协同作用.     

Red blood cells labelling with 99mTc‐d,l‐HMPAO: an alternative method for specific cases

The effectiveness of the classic methods for red blood cells (RBCs) labelling with ^99mTc has been demonstrated in nuclear medicine. However, nuclear physicians have found, in certain circumstances, this diagnostic technique fails and poor quality images are obtained. In this work we report on an alternative method that is of useful in these occasions, for in vitro labelling RBCs with ^99mTc‐d,l‐HMPAO complex. The study shows a high and reproducible labelling efficiency (94.14±0.38), using low amount of tin. The RBCs were isolated from plasma and other interfering blood cells before adding ^99mTc‐d,l‐HMPAO. The tracer was retained and the elution rate from RBCs was low (less than 6% after 120 min). The preclinical results indicate that this new method could be a good alternative to the standard classic methods for specific cases. Copyright © 2003 John Wiley & Sons, Ltd.