Treatment of acute graft-versus-host disease with humanized anti-Tac: an antibody that binds to the interleukin-2 receptor

Humanized anti-Tac is a genetically engineered human IgG1 monoclonal antibody specific for Tac, the alpha subunit of the interleukin-2 (IL- 2) receptor, and blocks IL-2-dependent activation of human T lymphocytes. The safety, pharmacokinetics, and immunosuppressive activity of humanized anti-Tac were evaluated in 20 patients who developed acute graft-versus-host disease (GVHD) after allogeneic marrow transplantation. Patients had developed acute GVHD at 5 to 26 (median, 14) days after transplantation and had failed to respond to primary therapy with glucocorticoids. Sequential groups of 4 patients each received a single 1-hour infusion of antibody in escalating doses of 0.5, 1.0, or 1.5 mg/kg; 8 additional patients were then treated with 1.5 mg/kg. A second infusion of antibody was administered after 11 to 48 (median, 16) days in 8 patients who had transient improvement of GVHD after the first infusion. Acute side effects, limited to chills in 1 patient and diaphoresis in another, were observed during or shortly after the antibody infusion. Overall improvement of acute GVHD occurred in 8 patients, 6 of whom were treated with a single antibody infusion and 2 with two infusions. Four responses were complete and 4 were partial. Three additional patients had improvement in one organ but progression in another. Responses occurred in 9 of 16 cases with skin disease, 3 of 15 with liver disease, and 6 of 12 with gastrointestinal disease. Two patients survive at 529 and 645 days after antibody treatment. Two patients died after relapse of leukemia. Sixteen patients died of infection or organ failure between 5 and 211 (median, 55) days. The terminal elimination half-life of the antibody was 44 to 363 hours, with a harmonic mean of 79, 88, and 94 hours, respectively, for the three doses studied. Absolute peripheral blood T-lymphocyte counts remained unchanged during the 56 days after infusion of the antibody. A fraction of circulating T cells expressed the alpha chain of the IL-2 receptor that, in some patients, was bound by antibody in vivo up to 28 days after treatment. No patient developed a measurable antibody response to humanized anti-Tac. Humanized anti-Tac has a long half-life after intravenous injection in humans, superior to any rodent monoclonal antibody specific for human T cells, and does not appear to induce antibody formation in recipients of marrow transplants. Improvement of steroid-refractory GVHD in 40% of patients after only one or two antibody infusions indicates that humanized anti-Tac is immunosuppressive.     

缺血性卒中的高血糖治疗

高血糖能加重急性脑梗死的脑损伤。研究者测试了急性脑梗死时静脉胰岛素强化治疗与普通护理相比的可靠性和耐受性，开展了一个12h内脑梗死的随机多中心双盲实验，其血糖水平≥8．3mmol／L，美国国立卫生研究所脑卒中评分（NIHSS）在3～22分。患者以2：1的比例被随机分配至连续性静脉输注胰岛素或规定每日4次皮下注射胰岛素的强化治疗组。强化治疗组的目标血糖水平〈7．2mmol／L，     

Ventilatory response during incremental exercise tests in weight lifters and endurance cyclists

Summary The effect of a progressively increasing work rate (15 W·min^–1) up to exhaustion on the time course of O₂ uptake ( ), ventilation ( ) and heart rate (HR) has been studied in weight lifters (WL) in comparison to endurance cyclists (Cycl) and sedentary controls (Sed). and were measured as average value of 30-s intervals by a semiautomatic open circuit method. was 2.55±0.33; 4.29±0.53 and 2.86±0.19·min^–1 in WL, Cycl and Sed respectively. With time and work rate, while and HR increased linearly, changed its slope at two levels. The 1st change occured at a work load corresponding to a mean (± SD) of 1.50±0.26; 1.93±0.34; and 1.23±0.14 l·min^–1 in WL, Cycl, and Sed respectively. values corresponding to the second change of slope were 2.18±0.32 in WL; 3.48±0.53 in Cycl and 2.17±0.28 l·min^–1 in Sed. The first change of slope might be the consequence of the different readjustment of on-response and hence of early lactate in the different subjects. The second change seems to be comparable to the conventional anaerobic threshold and is achieved in all subjects when vs time slope is 7–10 l·min^–1/min of exercise.This work has been supported in part by a grant from the Italian National Research Council (CNR)     

Cryopreservation of single human spermatozoa

A procedure is described that allows cryopreservation and efficient post-thaw recovery of either a single or a small group of human spermatozoa. This is achieved by injecting them into cell-free human, mouse or hamster zonae pellucidae before the addition of cryoprotectant. The method involves a combination of physical micromanipulation procedures and glycerol-mediated cryoprotection. Zonae were tracked by positioning them in straws between two small air bubbles prior to freezing. Spermatozoa from poor specimens were cryopreserved and their fertilizing ability after thawing was compared with that of fresh spermatozoa from fertile men. Human eggs used for fertilization testing were either 1 day old or in-vitro matured. Only 2% of the frozen zonae were lost and >75% of spermatozoa cryopreserved in this manner were recovered and prepared for intracytoplasmic sperm injection. The feasibility of cryopreserving a single spermatozoon was assessed. Fifteen motile spermatozoa were frozen in 15 zonae, of which 14 were recovered after thawing. Ten were injected into spare eggs, of which eight became fertilized. Spermatozoa recovered mechanically from human zonae fertilized the same proportion of oocytes as fresh fertile control spermatozoa. The recovery and fertilization rates with spermatozoa frozen in animal zonae were 87 and 78% respectively. The fertilization rate was marginally higher (P < 0.05) than that for spermatozoa frozen in human zonae, perhaps because the latter may have acrosome reacted more frequently. The zona pellucida appears to be an ideally suited sterile vehicle for storage of single spermatozoa.      

基于声速微扰的松质骨超声参数分析和计算

在生物组织非均匀连续介质模型的基础上，采用声速微扰法，通过分别改变入射频率、松质骨孔隙度及骨小梁特征尺寸等三个参数，对松质骨中的超声背向散射系数和由于散射而引起的衰减进行了分析。分析结果表明：由于散射而引起的衰减占松质骨中总的超声衰减的26％左右；当松质骨孔隙度在0．61附近时，衰减和背向散射系数均达到最大值。     

Archival fixed and analysed preimplantation human embryonic cells: a DNA resource for retrospective PCR analysis at the cellular level

Biopsies of human embryonic cell preparations previously analysed by cytogenetic and/or fluorescent in-situ hybridization (FISH) chromosome probes provide a unique reference DNA resource for the archival preimplantation genetic diagnosis (PGD) of the transferred embryo. DNA polymerase chain reaction (PCR) may be utilized on these fixed cell preparations to verify equivocal FISH/PGD results. Retrospective PCR screens of the genotype of biopsied embryonic cell(s) may be of benefit in the case of a suspected genetic mutation. Currently, carrier detection or linkage analysis is often not possible because of early death of the fetus, or of patients with a lethal disease. Alternatively, fixed/stained 'failed fertilized' oocytes provide a resource to extend genetic analysis to infertile patients. A successful research is described which minimizes loss of individual analysed fixed/stained oocytes, metaphase chromosomes, and embryonic cell samples. Initial DNA amplification takes place in situ using a modified PCR protocol. Comparative cellular studies using primer sets previously used for PGD analyses show that 65% of the preparations amplified unequivocally using the modified protocol and primers for a CA repeat motif gene sequence, in comparison with 81% using the original PCR protocol. With further refinement and optimization, the methods outlined have the potential to retrospectively screen archival fixed chromosomes, gametes, and embryonic cells for clinical application, and enable the further study of the fixed human preimplantation embryo at the morphological, cell and molecular level.      

Lymphocyte depletion during treatment with intensive chemotherapy for cancer

Recently we have observed an increased incidence of opportunistic infections in patients treated with intensive chemotherapy for cancer. Because T-cell depletion is associated with similar clinical events in human immunodeficiency virus infection and after bone marrow transplantation, we have analyzed peripheral blood lymphocyte populations in a series of patients during treatment with intensive chemotherapy for cancer. Although neutrophil, monocyte, and platelet numbers consistently recovered to greater than 50% of pretreatment values after each sequential cycle of therapy, lymphocyte numbers did not recover within the same time period. B cells decreased rapidly from a mean value of 149 +/- 46/mm3 before chemotherapy to 4 +/- 1/mm3 during chemotherapy (P = .01). CD4+ T cells decreased from a mean of 588 +/- 76/mm3 before chemotherapy to 105 +/- 28/mm3 during chemotherapy (P = .0002) and CD8+ T cells decreased from a mean of 382 +/- 41/mm3 before chemotherapy to 150 +/- 46/mm3 during chemotherapy (P = .0009). Natural killer cell numbers did not show significant declines (171 +/- 30/mm3 before, 114 +/- 24/mm3 during, P = .19). Based on the history of opportunistic complications in patients with other disorders who display similar degrees of CD4+ T-cell lymphopenia and preliminary observations in this population, immune incompetence could surface as a dose-limiting toxicity for highly dose-intensive chemotherapy regimens.     

Membrane Fluidity and Alcohol Dependence

Rats were chronically intoxicated with alcohol by exposing them to increasing concentrations of ethanol vapor over a 4-week period. They were tested for alcohol consumption in a free choice situation of water and 10% (v/v) alcohol. On the basis of their intakes they were divided into alcohol-dependent and nondependent groups. Synaptosome membrane fluidity evaluated by fluorescence polarization was compared between the two groups and against nonintoxicated controls. The intoxicated animals had a lower membrane fluidity than controls, mainly because of a highly significant increase of rigidity in the alcohol-dependent group. Furthermore, membrane fluidity was found to be correlated with the degree of behavioral dependence (i.e., alcohol intake during the free choice period).