Anti-cancer activity of withaferin A in B-cell lymphoma

Withaferin A (WA), a withanolide from the plant, Ashwagandha (Withania somnifera) used in Ayurvedic medicine, has been found to be valuable in the treatment of several medical ailments. WA has been found to have anticancer activity against various solid tumors, but its effects on hematological malignancies have not been studied in detail. WA strongly inhibited the survival of several human and murine B cell lymphoma cell lines. Additionally, in vivo studies with syngeneic-graft lymphoma cells suggest that WA inhibits the growth of tumor but does not affect other proliferative tissues. We demonstrate that WA inhibits the efficiency of NF-κB nuclear translocation in diffuse large B cell lymphomas and found that WA treatment resulted in a significant decrease in protein levels involved in B cell receptor signaling and cell cycle regulation. WA inhibited the activity of heat shock protein (Hsp) 90 as reflected by a sharp increase in Hsp70 expression levels. Hence, we propose that the anti-cancer effects of WA in lymphomas are likely due to its ability to inhibit Hsp90 function and subsequent reduction of critical kinases and cell cycle regulators that are clients of Hsp90.     

Transplantation of enriched and purged peripheral blood progenitor cells from a single apheresis product in patients with non-Hodgkin's lymphoma

High-dose chemotherapy with or without radiotherapy followed by autologous transplantation of hematopoietic progenitor cells is an effective treatment for patients with high-risk or relapsed non- Hodgkin's lymphoma. Chemotherapy and/or hematopoietic growth factors have been used to mobilize progenitor cells in the peripheral blood for transplantation. However, the mobilized blood cell products have been found to be frequently contaminated with tumor cells, and techniques have not been developed to purge tumor cells from these products. In addition, the minimum number of hematopoietic progenitor cells required for engraftment has not yet been fully elucidated. We treated 21 patients with a single infusion of cyclophosphamide (4 g/m2) followed by daily administration of granulocyte colony-stimulating factor (G- CSF). After recovery of the white blood cell count, a single 3-hour apheresis collection was performed. The apheresis product was then applied to a discontinuous Percoll gradient. The low-density fractions resulting from this separation procedure were enriched for CD34+ progenitor cells (total cell yield, 19.5%; CD34+ cell recovery, 81.2%). These enriched cellular products were treated with a panel of anti-B cell or anti-T cell monoclonal antibodies and complement in an effort to remove residual tumor cells. After treatment of the patient with myeloablative therapies, the enriched and purged cells were reinfused. Hematologic recovery was rapid, with median neutrophil engraftment in 10 days [absolute neutrophil count (ANC), greater than 0.5 x 10(9)/L] and 11 days (ANC, greater than 1.0 x 10(9)/L). Median platelet transfusion independence required 13 days. The rapidity of multilineage engraftment correlated with the number of CD34+ cells per kilogram that were infused. Patients who received more than 2 x 10(6) CD34+ cells per kilogram had rapid hematologic engraftment, whereas those patients transplanted with less than 2 x 10(6) CD34+ cells per kilogram had slower platelet recovery. Modeling studies using a lymphoma cell line with a t(14; 18) chromosomal translocation demonstrated the successful removal of tumor cells assayed using the polymerase chain reaction (PCR) after the processing and purging. Four of the 21 patients had PCR- detectable lymphoma cells in the bone marrow and peripheral blood; however, the enriched and purged blood products reinfused in all four did not contain detectable tumor cells.(ABSTRACT TRUNCATED AT 400 WORDS)     

An improved clonal excess assay using flow cytometry and B-cell gating

In humans with B-cell malignancies, the presence of monoclonal B lymphocytes (clonal proliferation) can be detected by comparing the fluorescence intensity distributions of lymphocytes stained with anti- kappa and anti-lambda reagents. The sensitivity of previously described single-color immunofluorescence techniques to low levels of clonal excess is limited by background from cytophilic immunoglobulins on non- B cells and by the low proportion of circulating B cells in individuals with minimal disease. We have used two-color immunofluorescence and B- cell gating to develop an improved assay that avoids false positives due to non-B cells, without requiring restrictive light scatter gates that may exclude true positives. This method is sensitive to 0.2% monoclonal B cells admixed with fresh normal lymphocytes, to 0.6% monoclonal B cells admixed with normal lymphocytes that have been stored for up to 72 hours, and readily detects 1% monoclonal cells in patient specimens. The two color B-cell gated assay offers sensitivity equivalent to the single-color assay and improved specificity for detection of low levels of clonal excess.     

Cerebrovascular effects of glibenclamide investigated using high-resolution magnetic resonance imaging in healthy volunteers

Glibenclamide inhibits sulfonylurea receptor (SUR), which regulates several ion channels including SUR1-transient receptor potential melastatin 4 (SUR1-TRPM4) channel and ATP-sensitive potassium (K_ATP) channel. Stroke upregulates SURl-TRPM4 channel, which causes a rapid edema formation and brain swelling. Glibenclamide may antagonize the formation of cerebral edema during stroke. Preclinical studies showed that glibenclamide inhibits K_ATP channel-induced vasodilation without altering the basal vascular tone. The in vivo human cerebrovascular effects of glibenclamide have not previously been investigated.In a randomized, double-blind, placebo-controlled, three-way cross-over study, we used advanced 3 T MRI methods to investigate the effects of glibenclamide and K_ATP channel opener levcromakalim on mean global cerebral blood flow (CBF) and intra- and extracranial artery circumferences in 15 healthy volunteers. Glibenclamide administration did not alter the mean global CBF and the basal vascular tone. Following levcromakalim infusion, we observed a 14% increase of the mean global CBF and an 8% increase of middle cerebral artery (MCA) circumference, and glibenclamide did not attenuate levcromakalim-induced vascular changes. Collectively, the findings demonstrate the vital role of K_ATP channels in cerebrovascular hemodynamic and indicate that glibenclamide does not inhibit the protective effects of K_ATP channel activation during hypoxia and ischemia-induced brain injury.     

TNF-α值与2型糖尿病胰岛素抵抗的关系

目的　探讨肿瘤坏死因子 -α(TNF -α)与 2型糖尿病胰岛素的关系。方法　用homa -R法选取有胰岛素抵抗 (IR组 )和无胰岛素抵抗 (NIR组 )的 2型糖尿病患者各 2 0例。另以 2 0名年龄及体重指数相匹配的人群的作为对照组 ,分别检测其空腹血糖、胰岛素 ,计算Homa -R值 ,用ELISA法检测TNF -α。结果　IR组的TNF -α与NIR组及对照组相比较明显增高 ,有统计学意义(P <0 0 5 ) ,IR组的空腹胰岛素水平及胰岛素抵抗指标Homa -R也显著高于NIR组及对照组 (P值为 <0 0 1) ,而三组间年龄、BMI、血脂、脂蛋白、血压均无显著性差异 (P >0 0 5 )。结论　血浆TNF -α水平与胰岛素抵抗呈密切相关 ,在 2型DM中有重要病理意义 ,可作为评估有无胰岛素抵抗的一项重要参考指标     

Characterization of mechanical dyssynchrony measured by gated single photon emission computed tomography phase analysis after acute ST-elevation myocardial infarction

Background

Left ventricular dyssynchrony is an adverse consequence of ST-elevation myocardial infarction (STEMI) and bears an unfavorable prognosis. Mechanical dyssynchrony as measured by phase analysis from gated single photon emission computed tomography (GSPECT) correlates well with other imaging methods of assessing dyssynchrony but has not been studied in STEMI. We hypothesized that systolic dyssynchrony as measured by GSPECT would correlate with adverse remodeling after STEMI.

Methods

In 28 subjects suffering STEMI, GSPECT with technetium-99m sestamibi was performed immediately after presentation (day 5) and remotely (6 months). Parameters of left ventricular dyssynchrony (QRS width, histogram bandwidth (HBW) and phase standard deviation (PSD)) were measured from GSPECT using the Emory Cardiac Toolbox. Left ventricular volumes, ejection fraction (LVEF) and infarct size were also assessed.

Results

After successful primary percutaneous coronary intervention to the infarct-related artery, subjects had an LVEF of 46.4% ± 11% and a resting perfusion defect of 27.4% ± 16% at baseline. Baseline QRS width was normal (91.5 ± 17.5 ms). Subjects with STEMI had dyssynchrony compared with a cohort of 22 normal subjects (age 57.2 ± 10.6 years, <5% perfusion defect) by both HBW (100.3° ± 70.7° vs 26.5° ± 5.3°, P < .0001) and PSD (35.3° ± 16.9° vs 7.9° ± 2.1°, P < .0001). Baseline HBW correlated with resting perfusion defect size (r = 0.67, P < .001), end-systolic volume (r = 0.72, P < .001), end-diastolic volume (r = 0.63, P = .001), and inversely with LVEF (r = ?0.74, P < .001). HBW and PSD improved over the follow-up period (?24.1 ± 35.9 degrees, P = .003 and ?8.7° ± 14.6°, P = .006, respectively), and improvement in HBW correlated with reduction in LV end-systolic volumes (r = 0.43, P = .034). Baseline HBW and PSD, however, did not independently predict LVEF at 6 months follow-up.

Conclusions

After STEMI, subjects exhibit mechanical dyssynchrony as measured by GSPECT phase analysis without evidence of electrical dyssynchrony. Improvement in mechanical dyssynchrony correlates with beneficial ventricular remodeling. The full predictive value of this measure in post-infarct patients warrants further study.