Differential inhibition by the Rho kinase inhibitor Y-27632 of the increases in contractility and Ca<Superscript>2+</Superscript> transients induced by endothelin-1 in rabbit ventricular myocytes

The role of Rho kinase activation in the regulation of cardiac contractility and Ca²⁺ signaling remains unclear, whereas its role in smooth muscle regulation has been well documented. To study the potential role of Rho kinase in the regulation of cardiac contractility and Ca²⁺ transients induced by endothelin-1 (ET-1) and isoproterenol, we used the Rho kinase inhibitor Y-27632 in rabbit ventricular myocardium and myocytes loaded with indo-1/AM. Y-27632 (3–30 M) inhibited significantly the baseline contractility and Ca²⁺ transients. Furthermore, Y-27632 suppressed the increase in contractility and Ca²⁺ transients induced by ET-1 in a concentration-dependent manner, when it was used in a concentration at which it did not affect the effects of isoproterenol via -adrenoceptors. In the presence of Y-27632, ET-1 increased cell shortening in the absence of an increase in Ca²⁺ transients. This is an indication that the increase in myofilament Ca²⁺ sensitivity induced by ET-1 is less susceptible to the inhibitory action of Y-27632. These findings imply that the Rho kinase activation may partially contribute to the ET-1-induced regulation of contractility, primarily due to an ET-1-induced increase in Ca²⁺ transients in rabbit ventricular myocardium.     

A phase I and pharmacokinetic study of VNP40101M,a new alkylating agent,in patients with advanced or metastatic cancer

Summary Purpose: VNP40101M is a new alkylating agent that demonstrated broad anti-tumor activity in murine tumor models. A phase I trial was initiated to determine the toxicities, maximum tolerated dose, and pharmacokinetics of VNP40101M by short IV infusion. Study design: The starting dose was 3 mg/m² every four weeks, and was escalated in successive cohorts as follows: 6, 12, 24, 40, 60, 80, and 100 mg/m². Beyond 100 mg/m², dose increments were 25%. Initially, 1–2 patients were assigned to a dose level. Intra-patient dose escalation was permitted. With the first instance of a drug-related grade 2 adverse event, all dose levels required assessment of 3–6 patients. Pharmacokinetic parameters were assessed in the first cycle and any cycle with a change in dose. Results: Twenty-six patients in 13 dose levels ranging from 3–305 mg/m² were evaluated. Dose-related thrombocytopenia was the major toxicity, with the nadir occurring at a median of day 27. At 305 mg/m², six of eight patients developed grade 3 thrombocytopenia, including one event that met the definition for DLT. Other dose-related toxicities included moderate granulocytopenia, anemia, and a mild infusion-related syndrome consisting of acute headache and facial flushing. The granulocyte nadir occurred at a median of day 34, and recovery of both thrombocytopenia and neutropenia to < grade 2 occurred at a median of day 43. VNP40101M peak plasma concentrations and AUC were linear with dose. The elimination half-life was short and estimated to be approximately 15 minutes. Conclusions: The MTD and recommended dose for phase II trials is 305 mg/m² every six weeks. Phase II trials in less heavily pre-treated patient populations are warranted.Supported by Vion Pharmaceuticals, Inc.     

Cyanidin 3-glucoside and peonidin 3-glucoside inhibit tumor cell growth and induce apoptosis in vitro and suppress tumor growth in vivo

Dietary polyphenols, including anthocyanins, are suggested to be involved in the protective effects of fruits and vegetables against cancer. However, anticancer effects of peonidin 3-glucoside have not been clearly demonstrated, with only limited studies being available concerning the inhibitory effect of cyanidin 3-glucoside for tumor cell growth. Therefore, in this study, we have isolated and identified the two bioactive compounds, peonidin 3-glucoside and cyanidin 3-glucoside, from Oryza sativa L. indica, to treat various cancer cells. The results showed that, among analyzed cell lines, HS578T was the most sensitive to peonidin 3-glucoside and cyanidin 3-glucoside. Treatment with peonidin 3-glucoside or cyanidin 3-glucoside resulted in a strong inhibitory effect on cell growth via G2/M arrest. Regarding cell cyclerelated proteins, peonidin 3-glucoside treatment resulted in down-regulation of protein levels of cyclin-dependent kinase (CDK)-1, CDK-2, cyclin B1, and cyclin E, whereas cyanidin 3-glucoside could decrease the protein levels of CDK-1, CDK-2, cyclin B1, and cyclin D1. In addition, cyanidin 3-glucoside or peonidin 3-glucoside also induced caspase-3 activation, chromatin condensation, and cell death. Furthermore, anthocyanins from O. sativa L. indica were evidenced by their inhibition on the growth of Lewis lung carcinoma cells in vivo.     

Assessing the effect of interventions in the context of mixture distributions with detection limits

Many quantitative assay measurements of metabolites of environmental toxicants in clinical investigations are subject to left censoring due to values falling below assay detection limits. Moreover, when observations occur in both unexposed individuals and exposed individuals who reflect a mixture of two distributions due to differences in exposure, metabolism, response to intervention and other factors, the measurements of these biomarkers can be bimodally distributed with an extra spike below the limit of detection. Therefore, estimating the effect of interventions on these biomarkers becomes an important and challenging problem. In this article, we present maximum likelihood methods to estimate the effect of intervention in the context of mixture distributions when a large proportion of observations are below the limit of detection. The selection of the number of components of mixture distributions was carried out using both bootstrap-based and cross-validation-based information criterion. We illustrate our methods using data from a randomized clinical trial conducted in Qidong, People's Republic of China.     

Daclizumab is associated with decreased rejection and no increased mortality in cardiac transplant patients receiving MMF, cyclosporine, and corticosteroids

BACKGROUND: Sparse published data exist on outcomes in daclizumab-treated cardiac transplant patients. One trial observed an increased mortality risk 6 and 12 months posttransplant in patients receiving daclizumab plus mycophenolate mofetil (MMF), cyclosporine, and steroids. This study further investigates the safety profile of daclizumab with this same immunosuppressive regimen from a large registry. METHODS: Data obtained at hospital discharge on all adult cardiac transplants performed in the USA between January 1998 and October 2003 for patients receiving MMF plus cyclosporine and steroids were accessed from the Scientific Registry of Transplant Recipients. Patients were selected based on induction treatment: daclizumab (n = 684) or no induction (n = 2525). Outcomes were evaluated at 6 months, 12 months, and 3 years posttransplant. Univariate Kaplan-Meier and multivariate Cox models were used to evaluate the effect of treatment on outcomes. Patient survival and infectious death were the primary endpoints. Secondary endpoints included rejection within the first year posttransplant (acute rejection; AR) and total rejection episodes over time. The two treatment groups shared similar demographics and transplant procedure details. RESULTS: Daclizumab (vs no induction) patients had no increased risk of patient death nor infectious death. Daclizumab patients had a lower incidence of AR at 6 months (P = .005) and 12 months (P < .001); the adjusted risk for AR at 12 months (hazards ratio [HR] = 0.77; P = .89) and over 3 years (HR 0.83, P = .006) was also lower in daclizumab-treated patients. CONCLUSIONS: In cardiac transplant patients, daclizumab (vs no induction) does not result in increased mortality or infectious death, and is associated with a lower incidence of AR.     

Apoptotic markers on lymphocytes and monocytes are unchanged during single hemodialysis sessions using either regenerated cellulose or polysulfone membranes

BACKGROUND: There is an increased rate of apoptosis of peripheral blood mononuclear cells (PBMCs) in patients undergoing hemodialysis (HD), but little is known about how different dialysis membranes may contribute to the process. We, therefore, studied the influence of two different dialysis membranes on apoptotic markers during HD. METHODS: 8 healthy controls and 8 patients on regular HD 3 times per week were enrolled in this cross-controlled study. Patients received HD using polysulfone and then regenerated cellulose dialysis membranes for one week each, sequentially. Serum was collected for C-reactive protein (CRP) detection; flow cytometry with dual antibody staining was used to measure the apoptotic markers Fas (CD95), FasL (CD 178) and TNF-R2 (CD120b) in T cells (CD3+), B cells (CD19+), and monocytes (CD14+) at 0, 15, 120 and 240 min after starting HD. We also measured total leukocyte numbers and differential white cell counts. RESULTS: Hemodialysis patients revealed lymphocytopenia, monocytopenia, higher CRP levels and higher Fas and TNF-R2 expression on lymphocytes and monocytes at baseline when compared with normal controls. Leukocyte numbers, including neutrophils, lymphocytes and monocytes, dropped significantly after 15 min of dialysis. There were no significant differences in Fas levels during hemodialysis on T and B lymphocytes or on monocytes. T lymphocyte FasL (CD 178) levels remained unchanged throughout the process. There was a significantly lower overall level of CD120b at 15 min of HD, whereas this marker was higher on monocytes after dialysis. There were no significant differences in the levels of apoptotic markers between the two membranes. CONCLUSION: Our results suggest that uremia itself contributes to PBMC apoptosis. The two different dialysis membranes used in this study did not influence apoptotic markers on PBMCs significantly, but increased TNF-R2 expression on monocytes during a single dialysis session.     

人血小板功能抗体及其片段的识别

目的研究特发性血小板减少性紫癜（ITP）患者血小板膜糖蛋白（GP）特异性IgG抗体及其片段的免疫活性及对血小板聚集功能的影响.方法用改良单克隆抗体特异性俘获血小板抗原技术（MAIPA）检测84例慢性ITP患者血浆中抗GPⅡb/Ⅲa、GPⅠb/Ⅸ及GPⅥ自身抗体,比浊法血小板聚集试验筛选出自身抗体阳性并能抑制血小板聚集的患者,用蛋白A柱纯化其血浆IgG抗体并用胃蛋白酶制备F（ab＇）2片段.检测纯化的IgG抗体及其酶切片段与血小板GP的结合活性及对正常人血小板聚集功能的影响.结果 （1）84例ITP患者血浆中,48例（57.1%）抗GPⅡb/Ⅲa和/或GPⅠb/Ⅸ和/或GPⅥ自身抗体阳性,其中7例（14.6%）明显抑制了二磷酸腺苷、瑞斯托霉素或胶原诱导的血小板聚集;（2）纯化的IgG及F（ab＇）2片段具有与相应血小板GP的结合活性;（3）4例患者纯化IgG及F（ab＇）2片段具有抑制血小板聚集的功能.结论 F（ab＇）2片段是IgG自身抗体的功能片段,它不但保留了良好的抗原结合活性且可部分抑制血小板聚集功能,为人源化血小板糖蛋白特异性抗体的制备奠定了基础.     

Endoscopic totally extraperitoneal inguinal hernioplasty under spinal anesthesia

OBJECTIVES: Although endoscopic totally extraperitoneal inguinal hernioplasty (TEP) confers superior early outcomes compared to those of open repair, the requirement of general anesthesia has been held as an argument against the application of TEP by opponents of laparoscopic surgery. To date, the literature on TEP performed under spinal anesthesia remains scarce. The present study reports our early experience performing TEP under spinal anesthesia in selected patients who were medically unfit for general anesthesia. METHODS: Between March 2003 and March 2004, 6 male patients underwent attempted TEP under spinal anesthesia. Selection criteria for the procedure included reducibility of the inguinal hernia and concomitant medical conditions precluding general aesthesia, such as impaired lung function. Informed consent was obtained in all patients. RESULTS: All patients were conscious and able to communicate verbally during the operation. TEP was successfully completed in 4 patients, with a mean operative time of 33 minutes. All 4 patients were asymptomatic and experienced no pain throughout the procedure. Conversion to open repair was required in 2 patients because of uncooperative movement in one, and inadequate neural blockade by spinal anesthesia in the other. Intraoperative cardiorespiratory parameters were stable in all patients. Postoperative urinary retention occurred in 1 patient. The mean length of follow-up exceeded 3 months, and no seroma or recurrence was detected clinically. CONCLUSION: Successful performance of TEP under spinal anesthesia requires the combined efforts of an experienced anesthesiologist, a skilled surgeon, and a cooperative patient. Our initial experience of TEP under spinal anesthesia appeared promising. TEP under spinal anesthesia may have a role in selected patients who are medically unfit for general anesthesia but are otherwise suitable for TEP.     

Recurrent life-threatening bradycardia in a child with retained tracheal stent

We report a child with a retained welded tracheal stent scheduled for removal developing refractory bradycardia and cardiac arrest during attempt to remove the stent. Cardiac massage and pacing were necessary to reestablish circulation. The same type of arrhythmia occurred three times in the postanesthetic care unit after tracheal suction or coughing.     

Steroid-induced avascular necrosis of the hip in neurosurgical patients: epidemiological study

BACKGROUND: Avascular necrosis (AVN) of the femoral head is perceived to be a rare complication of short-term steroid therapy for neurosurgical conditions but its precise risk is unknown. METHODS: Retrospective review of hospital records between 1994 and 2001. RESULTS: The risk of developing AVN of the femoral head is 0.3% with an incidence of one per one thousand patients per year. CONCLUSIONS: It would be advisable to minimize both the dosage and the duration of steroid treatment where possible.