Some studies on the mechanism of action of antibodies to nerve growth factor.

The effects of antibodies to the nerve growth factor from mouse salivary gland were examined in vitro and in vivo. Treatment of explants of receptive ganglia with antibody and complement did not produce cell damage as judged by the ability of the tissue to respond to nerve growth factor. New-born mice experimentally depleted of or genetically deficient in key complement components were susceptible to the action of the antiserum.These results show that the effect of the antibody is independent of complement and are consistent with the view that it acts by neutralization of endogenous nerve growth factor.     

纹状体源性神经营养因子的分离纯化和生物鉴定

纹状体是中脑黑质多巴胺神经元的主要靶组织，我们先前的研究曾指出，纹状体提取液能增一外培养的中脑黑质神经元的存活和发育，本研究是在此基础一步应用ＳｅｐｈａｄｅｘＧ－７５凝胶层析、高效液相色谱（ＨＰＬＣ）、反相高效液相色谱（Ｒ－ＨＰＬＣ），ＳＤＳ－ＰＡＧＥ等的分析，结合生物鉴定，从纹状体提取液中分离出化的活性因子－－纹关腐朽源性神经营养因子。该因子的分子量为１１．５ｋＤ，等电点为９．３９，它能促进体外     

Quantitation of antigen-specific immune responses in human immunodeficiency virus (HIV)-infected individuals by limiting dilution analysis

The lymphocyte proliferative response to recall antigens is lost following HIV infection. We sought to devise a means by which the functional immune status of persons in the early stages of HIV infection could be monitored quantitatively. The response to tetanus toxoid was examined in 45 HIV-infected individuals and 11 controls using conventional lymphocyte proliferative assays concurrently with limiting dilution analysis utilizing the secretion of interleukin-2 as the measure of a response. Our data show that the limiting dilution analysis detects tetanus toxoid-reactive T cells in 80% of those tested, as compared to only 44% by proliferation. However, the frequency of tetanus-reactive T cells in HIV-infected individuals (median frequency = 1/59,156) is decrease five-fold as compared to seronegative controls (median frequency = 1/11,599). Longitudinal studies demonstrated a time-dependent decrease in the frequency of tetanus-specific T cell responses in the HIV-infected individuals. Thus, the limiting dilution analysis is a quantitative approach for detecting antigen-specific T cells in HIV-infected individuals, and may be used to monitor changes in T cell function in HIV infection.     

The adaptation of the plaque reduction assay for measuring specific cytotoxic cells in limiting dilution cultures

The use of the original haemolytic plaque reduction technique to measure cytotoxic T lymphocytes (CTL) has been developed further as a rapid screening assay, particularly suitable for limiting dilution analyses. Using hybridoma cells as targets, the cytotoxicity has been measured by the loss of haemolytic plaque formation and by the reduction of the amount of haemolytic monoclonal antibody secreted from viable target cells into the assay supernatants. The assessment of large numbers of cytotoxic samples has been greatly facilitated by quantitating the amount of haemoglobin released in the assay with an automated microELISA multiscanner and by scoring visually using a modification of the spot test. Using these new techniques, relatively high frequency estimates of cytotoxic cell precursors in an allogeneic response (1 in 462 spleen cells) and an anti-fluorescein response (1 in 3970 spleen cells) were obtained.     

Kinetics of hepatic transport of 4-methylumbelliferone in rats. Analysis by multiple indicator dilution method

Hepatic elimination of 4-methylumbelliferone (4MU), which has been used as a model compound for conjugative metabolism, was studied by means of a multiple indicator dilution (MID) method in the isolated perfused rat liver. Using this method, three intrinsic hepatic clearances, CL _int,inf , CL _{int,eff, and} CL _{int,seq, which represent the influx, efflux, and sequestration processes, respectively, were obtained. When the dose was increased from a low dose (50 g/rat liver) to a high dose (3000 g/rat liver), the hepatic availability of 4MU increased from 0.11 to 0.73. With increasing dose, the} CL _{int,eff value increased approximately two times, while the} CL _{int,seq value decreased to approximately one-third. The remarkable dose dependence of hepatic availability was due to nonlinearity in both} CL _{int,eff and} CL _{int,seq values. However, the} CL_int,inf value was almost independent of dose. The dose-dependent change in CL_int,seq might be explained by the saturation of conjugative metabolism of 4-MU, while the increase in the CL _{int,eff value with increasing dose might be partly explained by the nonlinear tissue binding of 4-MU, since the tissue unbound fraction determined by an ultrafiltration method using liver homogenate increased approximately 1.5 times at higher concentration of 4-MU compared to that at lower concentrations. In addition, based on a comparison of the individual intrinsic clearances, i.e.}, CL _int,inf , CL _{int,eff, and} CL _{int,seq, the major determining process of the apparent hepatic intrinsic clearance of 4MU is thought to be the sequestration process at the high dose. However, at the low dose, the membrane transport process (influx and efflux processes) as well as the sequestration process also determine the apparent hepatic intrinsic clearance}.     

Clinical manifestations and outcome of nocardiosis and antimicrobial susceptibility of Nocardia species in southern Taiwan, 2011–2021

Background/PurposeNocardiosis is an uncommon infectious disease. This study aimed to assess the clinical outcome of patients with nocardiosis and examine the antimicrobial susceptibility profiles of Nocardia spp. isolated.MethodsWe retrospectively reviewed the medical records of all inpatients diagnosed with nocardiosis between 2011 and 2021. The identification of Nocardia spp. at the species level was performed with the use of MALDI-TOF and 16S rRNA assays. The antimicrobial susceptibility of Nocardia spp. was performed using the microbroth dilution method. Factors associated with 90-day all-cause mortality were identified in multivariate logistic regression analysis.ResultsOf 60 patients with nocardiosis in the 11-year study period, the lungs (55.0%) were the most common site of involvement, followed by the skin and soft tissue (45.0%). Twenty-two patients (36.7%) died within 90 days following the diagnosis. All of the Nocardia isolates were susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin, whereas more than 70% of the isolates were not susceptible to ciprofloxacin, imipenem-cilastatin, moxifloxacin, cefepime, and clarithromycin. Nocardiosis involving the lungs (relative risk [RR], 9.99; 95% confidence interval [CI], 1.52–65.50; p = 0.02), nocardiosis involving the skin and soft tissue (RR, 0.15; 95% CI, 0.02–0.92; p = 0.04), and treatment with trimethoprim-sulfamethoxazole (RR, 0.14; 95% CI, 0.03–0.67; p = 0.01) were independently associated with 90-day all-cause mortality.ConclusionsNocardia spp. identified between 2011 and 2021 remained fully susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin. Nocardiosis of the lungs, skin and soft tissue infection, and treatment with trimethoprim-sulfamethoxazole were independently associated with 90-day all-cause mortality.     

荧光微量检测细胞内DNA与蛋白质含量

应用荧光试剂（３３２５８Ｈｏｅｃｈｓｔ）微量测定细胞内ＤＮＡ含量,应用荧光胺（Ｆｌｕｏｒｅｓｃａｍｉｎｅ）微量测定细胞内蛋白质含量。结果：荧光试剂与ＤＮＡ的Ａ－Ｔ碱基形成复合物后,其激发波长（ＥＸ）由３２０ｎｍ移至３５０ｎｍ,发射波长（ＥＭ）由４８０ｎｍ移至４６０ｎｍ,且荧光强度大为增强。荧光胺与蛋白质反应生成强荧光化合物,在ＥＸ３９０ｎｍ,ＥＭ４７５ｎｍ条件下最低检测限为０．５μｇ／μｌ。该法操作简便,微量快速,重复性好。可用于荧光微量测定ＤＮＡ与蛋白质含量,还可用于观察细胞的增殖。     

胞磷胆碱钠氯化钠注射液及其注射液细菌内毒素检查法的研究

目的:胞磷胆碱钠氯化钠注射液是一种新型制剂,我们对其进行了细菌内毒素检查方法的研究,同时对原剂型胞磷胆碱钠注射液也进行了该方法研究。方法:对五个厂家的10批样品,采用不同生产厂家和规格的TAL,进行了干扰试验和细菌内毒素检查。结果:本品高浓度时对TAL与细菌内毒素的凝集反应有干扰作用,经稀释后可排除。结论:本品的不干扰浓度,以胞磷胆碱钠计为0.25mg·ml~(-1),可采用细菌内毒素检查法进行质量控制。     

受体T淋巴细胞克隆的建立及其抗原特异性的检测

目的　建立受体T淋巴细胞克隆后 ,进一步分析检测该克隆针对供体的抗原特异性。方法　供体鼠脾细胞免疫受体鼠 ,再分离、纯化受体鼠T细胞 ,克隆受体T细胞。将动物分组免疫 ,对各组受体作电镜观察淋巴细胞超微结构、MTT法测定淋巴细胞增生试验以及流式细胞分析T细胞亚群的变化 ,分析检测该克隆针对供体的抗原特异性。结果　①受体针对供体抗原特异性T淋巴细胞克隆稳定建立 ;②经免疫组的受体T细胞超微结构改变显著 ,淋巴细胞增生试验及流式细胞分析结果与对照组的差异有显著性意义 (t>t0 0 5)。结论　成熟T淋巴细胞 ,在一定条件下仍可发生分裂和增生 ,形成克隆。通过供体脾细胞抗原特异性刺激 ,检测证明最终筛选出的T细胞克隆具有针对供体的抗原特异性     

A new approach to the limiting dilution assay

Improved methods of human immunodeficiency virus isolation have sparked an increased interest in determination of the number and proportion of infected cells in plasma samples. The limiting dilution assay is a popular method of determining the proportion of infected cells. We propose a new estimator of the proportion of infected cells based on an underlying Markov chain model for the progression of infected cells to further flasks in the series. This method should improve both design and analyses of these assays.