Carotid intima-media thickness, carotid wall shear stress and restenosis after femoro-popliteal percutaneous transluminal angioplasty (PTA).

OBJECTIVE: To determine the relationship between carotid intima-media thickness (IMT), carotid wall shear stress (WSS) and restenosis after femoro-popliteal percutaneous transluminal angioplasty (PTA). PATIENTS AND METHODS: Thirty-one subjects (18 men, 13 women, median age 69 years) treated with femoro-popliteal PTA for symptomatic peripheral arterial occlusive disease were enrolled. On admission, IMT, internal diameter and blood velocity of the common carotid artery (CCA) were assessed by high-resolution ultrasonography. Blood viscosity was measured and carotid WSS was calculated. Patients were followed up for 6 months for the occurrence of significant restenosis (>50%) as documented by duplex ultrasonography. Two patients were lost to follow-up. RESULTS: Fourteen patients (48%) developed restenosis at 6 months. IMT and WSS were not different in patients without and with restenosis (IMT: 0.90 (0.85-0.97) vs. 0.89 (0.84-0.93) mm, p = 0.51; WSS: 14.1 (11.9-19.2) vs. 15.9 (12.8-21.5) dyne/cm2, p = 0.48). The hazard ratio of incident restenosis as estimated by Cox regression analysis was 0.04 for IMT (p = 0.23; 95% CI 0.0001-8.22) and 1.07 for WSS (p = 0.10; 95% CI 0.98-1.17). CONCLUSIONS: In this pilot study involving a limited number of patients, carotid IMT and carotid WSS are not significantly related to restenosis at 6 months after femoro-popliteal PTA. This might be the result of different underlying pathophysiology for atherosclerosis and restenosis.     

B超诊断腰椎间盘突出症的临床价值(附64例分析)

报告经CT检查和临床治疗证实的64倒腰椎间盘突出症的B超检查结果,B超检出70个突出之椎间盘,CT检出73个,阳性率之比为70/73。70个突出椎间盘中,中央型5个,偏中央型20个,后外侧型44个,极外侧型1个;轻度30个,中度28个,重度12个。分型分度与临床表现及治疗选择有密切关系。B超检查与CT相此较,具有近似的诊断价值,但经济、实用,操作简单方便,值得推广。     

Antimetastatic effects of razoxane in a rat osteosarcoma model

The cytostatic and antimetastatic activities of 1,2-di(3,5-dioxopiperazin-1-yl) propane (ICRF-159, razoxane) were studied in a transplantable, slowly growing osteosarcoma in Sprague-Dawley rats. This tumor model is characterized by osteoid formation and spontaneous metastasization to lungs, kidneys and lymph nodes. Razoxane given intraperitoneally (i.p.) from 2 days before to 14 days after tumor transplantation (30 mg/kg or 10 mg/kg per day) resulted in a dose-dependent prolongation of median survival time (83 or 48 days respectively, versus 38 days for the control group), but showed no influence on the growth of the primary tumor.Early treatment with razoxane (30 mg/kg i.p. from day –2 to + 14) showed a greater inhibition of pulmonary metastases than later treatment (30 mg/kg i.p. from day +14 to +28 after transplantation). Whereas 59·9 per cent of the total sectional area of the lungs in the control animals was covered by osteosarcoma metastases, only 3·4 per cent and 26·1 per cent respectively was affected in the early and late razoxane treatment groups. Toxic side-effects of these treatment schedules were reversible diffuse alopecia, but no retardation of body weight gain.     

Analysis of T cell activation with a non-mitogenic anti CD3 antibody and the phorbol ester TPA.

We used a non mitogenic anti CD3 antibody, termed VIT3, to study the signals required for the activation of normal resting T lymphocytes. Besides being not mitogenic, this antibody completely inhibits mitogen induced proliferative responses. In the presence of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), however, VIT3 induces DNA replication and cell proliferation comparable to PHA responses. In addition, T cells cultured with VIT3 plus TPA but not with VIT3 or TPA alone express high levels of interleukin 2 (IL-2) receptors and transferrin receptors. This co-stimulation appears to be accessory cell independent. Purified T cells respond equally well to VIT3 plus TPA as do unseparated mononuclear cells and addition of non-T cells has no enhancing effect. We conclude that the IgM antibody VIT3, although non-mitogenic by itself, still delivers a first and for the activation essential signal. In resting T cells this signal does not induce demonstrable anti-Tac antibody binding nor does it lead to a fully developed proliferative response in the presence of recombinant IL-2. Together with a second signal provided by TPA it serves, however, as a potent inducer of T cell growth.     

LDL accumulation in the grossly normal human iliac bifurcation and common iliac arteries

We had previously used an electrophoretic transfer procedure to determine the topographic distribution of low density lipoprotein (LDL) accumulation in the aortic intima of normolipemic swine. In this present study we have employed a similar procedure to assess whether LDL-rich sites consistently demonstrate increased intimal thickening at the iliac bifurcation and common iliac arteries. The topographic distribution of LDL-rich sites was determined in the aortas of six subjects ranging in age from 16 to 36 years, by transferring LDL by electrophoresis from the tissue into an agarose gel containing anti-LDL, and then staining the immunofixed LDL in the gel for lipid. LDL-rich sites were found in all but two of these cases. On the basis of control studies establishing the level of nonspecific staining, we determined that the cutoff between LDL-rich and LDL-poor zones was 37 mg apoB protein/mm2 intimal surface area. Intimal thickening was found to be threefold greater in LDL-rich than in LDL-poor regions. These results confirm and extend earlier immunohistochemical studies suggesting a preferential accumulation of LDL at sites of intimal thickening in human arteries.     

Enhanced cellular immune response and reduced CD8(+) lymphocyte apoptosis in acutely SIV-infected Rhesus macaques after short-term antiretroviral treatment

Losing the decisive virus-specific functions of both CD4(+) and CD8(+) T lymphocytes in the first weeks after immunodeficiency virus infection ultimately leads to AIDS. The SIV/rhesus monkey model for AIDS was used to demonstrate that a 4-week chemotherapeutic reduction of viral load during acute SIV infection of macaques allowed the development of a competent immune response able to control virus replication after discontinuation of treatment in two of five monkeys. Increasing SIV-specific CD4(+) T-helper-cell proliferation was found in all macaques several weeks after treatment, independent of their viral load. However, only macaques with low viral loads showed persistent T-cell reactivity of lymph node cells. In contrast to animals with higher viral loads, T-helper-cell counts and memory T-helper cells did not decline in the two macaques controlling viral replication. Lymphocyte apoptosis was consistently low in all treated macaques. In contrast, high CD8(+) lymphocyte death but only slightly increased CD4(+) lymphocyte apoptosis were observed during the first weeks after infection in untreated control animals, indicating that early apoptotic death of virus-specific CTL could be an important factor for disease development. Antiretroviral treatment early after infection obviously retained virus-specific and competent T lymphocytes, whereby a virus-specific immune response could develop in two animals able to control the viral replication after cessation of treatment.     

Effects of acute tryptophan depletion on negative symptoms and smoking topography in nicotine-dependent schizophrenics and nonpsychiatric controls.

We studied the effect of acute tryptophan depletion (ATD), which transiently reduces brain serotonin, on negative symptoms and cigarette smoking topography in schizophrenic smokers. Nicotine-dependent schizophrenics (n=11) and nonpsychiatric controls (n=8) were examined after ingesting comparable mixtures that do and do not deplete plasma tryptophan. Tryptophan-depleting and placebo mixtures were administered double-blind and in counterbalanced order. Conditions were separated by a 1-week interval. Psychopathologic symptoms (negative symptoms, depression) and smoking topography (time to first puff, number of puffs per cigarette, puff duration, interpuff interval, cigarette duration, and percentage of cigarette smoked) were measured before ingestion and again beginning 5 h after each mixture, corresponding to the time of maximal tryptophan depletion. Analyses were conducted using repeated measures analyses of variance (psychopathologic symptoms) and analyses of covariance (smoking topography) controlling for cigarette length. We found that ATD influenced smoking topography in both schizophrenics and nonpsychiatric controls in a manner suggestive of increased desire to smoke. Schizophrenics exhibited increased puff duration and decreased cigarette duration. Controls displayed increased puff duration. ATD did not produce changes in negative symptoms or depression. Compromising brain serotonin via ATD appears to intensify smoking behavior in nicotine-dependent individuals directly, rather than indirectly through changes in either mood or psychopathologic symptoms.     

A new membrane-attack complex/perforin (MACPF) domain lethal toxin from the nematocyst venom of the Okinawan sea anemone Actineria villosa.

The Okinawan sea anemone Actineria villosa causes severe cases of stinging. We isolated the 60 kDa A. villosa toxin (AvTX-60A) as the major toxin from the isolated nematocysts of this species. AvTX-60A showed fatal toxicity to mice with intraperitoneal injection at a minimum lethal dose of less than 250 microg/kg. The N-terminal amino acid sequence was determined and the corresponding cDNA encoding AvTX-60A was sequenced. The deduced amino acid sequence of AvTX-60A showed high similarity with PsTX-60A, which had been isolated as one of the major toxins from the venomous sea anemone Phyllodiscus semoni. These sea anemone toxins are new members of the family of proteins containing membrane-attack complex/perforin (MACPF) domains, best known in pore forming proteins such as perforin. These are the first examples of MACPF domain proteins as toxins for prey acquisition or repelling predators in nature.