[Preparation and evaluation of in-situ synthesis zeolite gas-liquid modified columns]

A new kind of NaA zeolite column has been prepared by in-situ synthesis technique. In comparing with traditional coating method, the in-situ NaA zeolite carrier is much more uniform and rigid. Several kinds of zeolite gas-liquid modified columns have been prepared with this in-situ technology, which showed satisfactory features in separation property and thermal stability. The successful utilization of mini-length and wide-bore columns showed good practical prospect of this new kind of zeolite column.

Validity of the updated pediatric risk of mortality score (PRISM III) in predicting the probability of mortality in a pediatric intensive care unit

This study assessed the validity of the PRISM III scoring system in accurately predicting the probability of mortality in a pediatric intensive care unit (PICU) in Taiwan. We collected data from consecutive patients admitted to our PICU during a one-year period from November 1999 through October 2000. Our PICU had 412 admissions including 385 patients (202 boys and 183 girls) with an average age of 53.9 +/- 58.2 months (range: 1 month to 18 years). The most common reason for admission was respiratory failure (26.2%). Almost 60% of the patients had at least one underlying chronic disease. The average duration of stay was 4.52 +/- 8.43 days (range 1 day to 81 days). The average PRISM III score was 5.06 +/- 6.95 (range 0-44). The overall mortality rate in the PICU was 8.17%. The mortality rate was not significantly different from the predicted rate (7.56%) (p=0.65). The efficiency of care was 32.5% and the standardized PICU length of stay ratio (SLOSR) was 1.33. The SLOSR ratio was significantly higher than the predicted rate (p value < 0.001). The PRISM III score was validfor assessing mortality risk of PICU patients in this hospital in Taiwan. However, the SLOSR ratio obtained in this study was higher than predicted. Differences in the patterns of practicing medicine may play an important role in observed PICU length of stay. Special caution is needed in adopting a severity of illness scoring system to assess performance of care, particularly in contexts different from the ones in which the instrument was originally developed. Further study including more pediatric intensive care units and other regions would enable greater generalization of the validity of this instrument.

Mechanism of fenretinide (4-HPR)-induced cell death

4-HPR (fenretinide) is a synthetic analog of retinoic acid (RA) whose potential as a chemopreventative agent has gained support from in vitro and animal experiments and in limited clinical trials. Comparative analyses of cellular, biochemical, and molecular properties of fenretinide with RA using various tissue culture cells reveal that a key distinction between these two retinoids lies in the ability of fenretinide to induce programmed cell death, also known as apoptosis. Here we review the composite evidence for induction of apoptosis in fenretinide-treated cells. Assays used to validate apoptosis in various cell types are also summarized. Apoptosis in response to fenretinide primarily occurs by a receptor-independent mechanism, which is accompanied by increases in signaling molecules, e.g., ceramide, and cysteine-dependent aspartate-directed proteases, termed caspases, including execution caspase-3. Both caspase-3 inhibitor DEVD-CHO and ceramide synthase inhibitor fumonisin B(1) (FB(1)) block fenretinide-induced apoptosis. Increase in caspase-3 appears to result from fenretinide-elicited stabilization of procaspase-3 zymogen. We also review apoptotic regulatory proteins such as inhibitor of apoptosis (IAPs) and second mitochondria-derived activator of caspase (SMACs) that participate in the coordinate control of caspase activities. The existence of a large number of proteins capable of modulating apoptosis via activation or inhibition of caspases, coupled with the fact that both the initiation and execution phases of apoptosis utilize pre-existing zymogens, which, once set in motion, culminates in an irreversible apoptotic cascade, raise the possibility that the on/off switch of apoptosis is linked to an intricate intracellular regulatory network, capable of responding to external stimuli such as fenretinide. This network functions to provide checks/balances of the need for apoptosis as well as to minimize and prevent untimely errors in apoptosis. We suggest that dynamic and coordinated regulation of apoptosis by such a hypothetical network in vivo may involve co-localization of pro- and anti-apoptotic proteins and their respective activators/inhibitors in a macromolecular modular unit which we propose to be named caspasomes. Fenretinide also induces apoptosis by elevating reactive oxygen species (ROS), unrelated to changes in ceramide-caspases. Thus multiple, distinct pathways contribute to the induction of apoptosis by fenretinide.

Neuroendocrine and behavioral implications of endocrine disrupting chemicals in quail

Studies in our laboratory have focused on endocrine, neuroendocrine, and behavioral components of reproduction in the Japanese quail. These studies considered various stages in the life cycle, including embryonic development, sexual maturation, adult reproductive function, and aging. A major focus of our research has been the role of neuroendocrine systems that appear to synchronize both endocrine and behavioral responses. These studies provide the basis for our more recent research on the impact of endocrine disrupting chemicals (EDCs) on reproductive function in the Japanese quail. These endocrine active chemicals include pesticides, herbicides, industrial products, and plant phytoestrogens. Many of these chemicals appear to mimic vertebrate steroids, often by interacting with steroid receptors. However, most EDCs have relatively weak biological activity compared to native steroid hormones. Therefore, it becomes important to understand the mode and mechanism of action of classes of these chemicals and sensitive stages in the life history of various species. Precocial birds, such as the Japanese quail, are likely to be sensitive to EDC effects during embryonic development, because sexual differentiation occurs during this period. Accordingly, adult quail may be less impacted by EDC exposure. Because there are a great many data available on normal development and reproductive function in this species, the Japanese quail provides an excellent model for examining the effects of EDCs. Thus, we have begun studies using a Japanese quail model system to study the effects of EDCs on reproductive endocrine and behavioral responses. In this review, we have two goals: first, to provide a summary of reproductive development and sexual differentiation in intact Japanese quail embryos, including ontogenetic patterns in steroid hormones in the embryonic and maturing quail. Second, we discuss some recent data from experiments in our laboratory in which EDCs have been tested in Japanese quail. The Japanese quail provides an excellent avian model for testing EDCs because this species has well-characterized reproductive endocrine and behavioral responses. Considerable research has been conducted in quail in which the effects of embryonic steroid exposure have been studied relative to reproductive behavior. Moreover, developmental processes have been studied extensively and include investigations of the reproductive axis, thyroid system, and stress and immune responses. We have conducted a number of studies, which have considered long-term neuroendocrine consequences as well as behavioral responses to steroids. Some of these studies have specifically tested the effects of embryonic steroid exposure on later reproductive function in a multigenerational context. A multigenerational exposure provides a basis for understanding potential exposure scenarios in the field. In addition, potential routes of exposure to EDCs for avian species are being considered, as well as differential effects due to stage of the life cycle at exposure to an EDC. The studies in our laboratory have used both diet and egg injection as modes of exposure for Japanese quail. In this way, birds were exposed to a specific dose of an EDC at a selected stage in development by injection. Alternatively, dietary exposure appears to be a primary route of exposure; therefore experimental exposure through the diet mimics potential field situations. Thus, experiments should consider a number of aspects of exposure when attempting to replicate field exposures to EDCs.

Implications of quantitative tumor and nodal regression rates for nasopharyngeal carcinomas after 45 Gy of radiotherapy

PURPOSE

To quantitatively investigate the clinical implications of tumor regression rate (TRR-45) and nodal regression rate (NRR-45) of nasopharyngeal carcinomas (NPC) after receiving 45 Gy of radiotherapy (RT). The values, predictive values, and associated factors of TRR-45 and NRR-45 in NPC are analyzed.

METHODS AND MATERIALS

One hundred one patients with newly diagnosed NPC and who were curatively treated by RT alone were included in the study. Tumor volume and nodal volume before treatment and after 45 Gy were obtained from computed tomographic (CT) scans performed at those times and calculated with the assistance of a computer-based imaging analyzing system. TRR-45 (NRR-45) was defined as the ratio of reduced tumor (nodal) volume after 45 Gy to the initial tumor (nodal) volume. TRR-45 (NRR-45) values were stratified into three groups of slow (below 50%), moderate (between 50% and 75%), and rapid (above 75%) change. After conventional RT with 45 Gy, conformal RT for primary tumors was boosted to 70.2-72 Gy for T1-2 tumors, and 75.6-81 Gy for T3-T4 tumors. RT for residual neck masses was boosted by electron beam to 61-75 Gy.

RESULTS

The mean value of TRR-45 for all patients was lower than that of NRR-45 for the 78 patients with metastatic neck nodes (70% +/- 4.8% vs. 81% +/- 5%, p = 0.003). The 3-year actuarial neck control rate was better than the primary tumor control rate with statistical significance (98% vs. 85%, p = 0.009). No significant statistical differences concerning local control probability, nodal control probability, or survival rate were found among patients with slow, moderate, or rapid TRR-45 or NRR-45. T-stage was the only significant prognostic factor for locoregional control after multivariate analysis. Tumor volume and T-stage were found to have a statistically significant negative correlation with TRR-45. No associated factor was found to be significantly correlated with NRR-45.

CONCLUSION

Slow regression rates of the primary tumor or neck nodes in NPC after receiving 45 Gy of irradiation do not mean ultimately poor radiocurability, but may merely imply slow clearance of the cells damaged during irradiation. The different radiobiological behaviors of the regression rates during treatment, ultimate control probabilities, or associated factors for regression rates of NPC between primary tumors and neck nodes need to be further investigated.

Mechanism of cardioprotection by resveratrol, a phenolic antioxidant present in red wine (Review)

Coronary heart disease (CHD) has been and remains a major contributor to morbidity and mortality in developed countries. The most common form of CHD in the western world is atherosclerosis (AS), especially of the major coronary arteries. Failure to maintain an intact endothelium, as a result of episodic and/or persistent injury and perturbation of the vascular endothelium, promotes formation of fatty streaks which are considered initiation events of AS. Cellular constituents contributing to endothelial injury include endothelial cells, monocytes, platelets, and smooth muscle cells. Individuals diagnosed with AS face complex, enduring clinical complications and enormous medical costs. Simple and easily compliant prevention and treatment measures are therefore strategic considerations in the management of this vascular disease. Based on known risk factors for CHD, priorities in AS prevention should include smoking cessation, blood pressure control, and diet modification. In recent years, the possible benefits of low to moderate consumption of alcoholic beverages, particularly of red wine, in the prevention of heart disease has received increasing attention and debate in the popular media as well as in the scientific community. Such attention has been prompted by research findings supporting a relationship between red wine consumption and the French paradox. This phenomenon refers to people residing in certain parts of France where red wine is customarily consumed during meals having a low CHD mortality, despite living a lifestyle considered to have comparably high CHD risks, as those in the US and many other developed countries. Studies have reported that the cardioprotective effects of red wine are greater than those attributed solely to ethanol and other types of alcoholic beverages. The mechanism(s) underlying the greater CHD protective benefits of red wine have not been elucidated. Recently the polyphenol resveratrol (3,5,4'-trihydroxy-trans-stilbene), known to be abundantly present in red wine, compared to white wine, beer, or spirits, has been demonstrated to elicit a broad spectrum of biological responses in in vitro and in animal studies, including effects that are compatible with the cardioprotective roles proposed for red wine. These recently described effects of resveratrol will be reviewed in this article. We will first summarize published data showing an inverse association between consumption of alcoholic beverages/red wine and risk of CHD. A review of biosynthesis of resveratrol and its presence in food groups and wines will follow. Recent studies relating exposure to wine/resveratrol with reduction in myocardial damage during ischemia-reperfusion, modulation of vascular cell functions, inhibition of LDL oxidation, and suppression of platelet aggregation will be presented. The last section of this review will focus on a discussion of mechanism(s) by which resveratrol acts as a potential cardioprotective agent.

Detection of caspases activation by fluorochrome-labeled inhibitors: Multiparameter analysis by laser scanning cytometry

BACKGROUND

The fluorochrome-labeled inhibitors of caspases (FLICA) were recently used as markers of activation of these enzymes in live cells during apoptosis (Bedner et al.: Exp Cell Res 259:308-313, 2000). The aims of this study were to (a) explore if FLICA can be used to study intracellular localization of caspases; (b) combine the detection of caspase activation with analysis of the changes with cell morphology detected by microscopy and laser scanning cytometry (LSC); and (c) adapt the assay to fixed cells that would enable correlation, by multiparameter analysis, of caspase activation with the cell attributes that require cell permeabilization in order to be measured.

METHODS

Apoptosis of human MCF-7, U-937, or HL-60 cells was induced by camptothecin (CPT) or tumor necrosis factor-alpha (TNF-alpha) combined with cycloheximide (CHX). Binding of FLICA to apoptotic versus nonapoptotic cells was studied in live cells as well as following their fixation and counterstaining of DNA. Intensity of cell labeling with FLICA and DNA-specific fluorochromes was measured by LSC.

RESULTS

Exposure of live cells to FLICA led to selective labeling of cells that had morphological changes characteristic of apoptosis. The FLICA labeling withstood cell fixation and permeabilization, which made it possible to stain DNA and measure its content for identification of the cell cycle position of labeled cells. When fixed cells were treated with FLICA, both apoptotic and nonapoptotic cells became strongly labeled and the labeling pattern was consistent with the localization of caspases as reported in the literature. A translocation of the FLICA binding targets from mitochondria to cytosol was seen in the MCF-7 cells treated with CPT. FLICA binding was largely (> 90%) prevented by the substrates of the caspases or by the unlabeled caspase inhibitors having the same peptide moiety as the respective FLICA.

CONCLUSIONS

The detection of caspase activation combined with cell permeabilization requires exposure of live cells to FLICA followed by their fixation. Cell reactivity with the respective FLICA, under these conditions, identifies the activated caspases and makes it possible to correlate their activation with the cell cycle position and other cell attributes that can be measured only after cell fixation/permeabilization. FLICA can also be used to study intracellular localization of caspases, including their translocation.

Synthesis and cytotoxicity of artemisinin derivatives containing cyanoarylmethyl group

A series of 12alpha-deoxoartemisinyl cyanoarylmethyl dicarboxylates (4a-4o), dicarboxylic acids 12alpha-deoxoartemisinyl ester cyanoarylmethyl amide (5a-5k), and dicarboxylic acids 12alpha-deoxoartemisinyl ester N-methylcyanoarylmethyl amide (6a-6l), showing moderate cytotoxicity against P388 and L1210 cells were prepared. They induced the significant accumulation of L1210 and P388 cells in the G1 phase of the cell cycle. This mechanism of action was quite different from that of the majority of cytotoxic compounds used in the chemotherapy of cancer. Compound 4b possessed better cytotoxicity than the other compounds.

Specific immunotherapy by genetically engineered APCs: the "guided missile" strategy

We tested the hypothesis that APCs genetically engineered to present an Ag and to express Fas ligand (FasL) simultaneously can target and eliminate Ag-specific T cells. Transgenic T cells specific for influenza hemagglutinin (HA) were used as targets. We prepared recombinant vaccinia virus vectors (VVV) to transfer the gene constructs individually or simultaneously into APCs. We prevented unwanted viral replication by attenuating the VVVs with psoralen-UV light treatment. For presentation of the HA Ag, APCs were transduced with cDNA for HA flanked by sequences of the lysosome-associated membrane protein that direct efficient processing and presentation of the Ag by APCs. As a "warhead" for the APCs, we transduced them with the gene for FasL, which induces apoptosis of Fas-expressing activated T cells. To protect the transduced APCs from self-destruction by FasL, we transferred cDNA for a truncated form of Fas-associated death domain, which inhibits Fas-mediated cell death. Our results show that the engineered APCs effectively expressed the genes of interest. APCs transduced with VVV carrying all three gene constructs specifically killed HA-transgenic T cells in culture. Coculture with T cells specific for an unrelated Ag (OVA) had no significant effect. Our in vitro findings show that APCs can be genetically engineered to target and kill Ag-specific T cells and represent a promising novel strategy for the specific treatment of autoimmune diseases.

Specific immunotherapy of experimental myasthenia gravis in vitro: the "guided missile" strategy

We describe a strategy for specific immunotherapy of myasthenia gravis (MG) based on genetic engineering of antigen presenting cells (APCs) to present the autoantigen acetylcholine receptor (AChR) and express the "warhead" Fas ligand (FasL). For transduction of APCs we prepared recombinant attenuated vaccinia virus vectors carrying the following three gene constructs: (i) AChR fused to LAMP1 to present AChR and target AChR-specific T cells; (ii) FasL to eliminate the targeted T cells; and (iii) truncated FADD to protect APCs from self-destruction by FasL. The engineered APCs effectively expressed the genes of interest and killed AChR-specific T cells in culture by the Fas/FasL pathway. T cells specific for an unrelated antigen were spared. Our in vitro demonstration that engineered APCs target and kill antigen-specific T cells represents a promising novel strategy for specific immunotherapy of MG and other autoimmune diseases.

[Study on the preparation of baicalin complex with phospholipid]

OBJECTIVE

To choose the optimization conditions for the formation of baicalin complex with phospholipid.

METHOD

A reasonable criterion of accurate evaluation was established, by which such factors as temperature, the ratio of baicalin to phospholipid and the concentration of reactants were examined and the orthographic design was used.

RESULT

The best conditions were obtained through statistical analysis and proof test.

CONCLUSION

The formation of baicalin complex with phospholipid was greatly influenced by the solvent, concentration and reactant ratio.

Antimicrobial susceptibility of Ehrlichia phagocytophila

Human granulocytic ehrlichiosis is a recently described disease caused by an obligate intracellular gram-negative organism recently named Ehrlichia phagocytophila. To expand our knowledge of the susceptibility of E. phagocytophila, we tested six New York State isolates for susceptibility to 12 antimicrobials using an HL-60 cell culture system. All of the isolates were susceptible to doxycycline (MIC, < or =0.125 microg/ml; minimum bactericidal concentration [MBC], 0.125 to 0.5 microg/ml), rifampin (MIC, < or =0.125 microg/ml; MBC, < or =0.125 microg/ml), ofloxacin (MIC, < or =2 microg/ml; MBC, < or =2 microg/ml), levofloxacin (MIC, < or =1 microg/ml; MBC, < or =1 microg/ml), and trovafloxacin (MIC, < or =0.032 microg/ml; MBC, < or =0.032 microg/ml). Isolates were uniformly resistant to amoxicillin, ceftriaxone, erythromycin, azithromycin, clarithromycin, and amikacin. For one strain, the MBC of chloramphenicol was < or =8 microg/ml. These data suggest that quinolone antibiotics and rifampin may be alternative agents for patients with intolerance to tetracyclines.

The effects of aging on AV nodal recovery properties

The purpose of this study was to assess the changes of AV nodal recovery properties with aging. Although in children and young adults it was found that there were age dependent changes in their AV nodal recovery properties, in the older population this information was not available. In 92 subjects (aged 16-92 years) without AV nodal disease or dual AV nodal pathway physiology, their AV nodal recovery curves were studied by delivering premature atrial extrastimuli coupled to basic atrial beats during cardiac electrophysiological study. Data were analyzed using linear regression and curve-fitting techniques. Patients were grouped by age, group I < 40 years (n = 33), group II 40-59 years (n = 26), and group III > 60 years (n = 33). The results showed that the AV nodal recovery curve did not change significantly in the aging process except that the AV nodal effective refractory period had a positive correlation with increasing age. The latter was significantly increased in group III when compared to group I or group II. For this parameter, when patients whose AV nodal refractory period was limited by the atrial refractory period were excluded, there was still a statistically significant increase in group III compared to group II (P < 0.05): group I (n = 27): 202+/-42 ms; group II (n = 17): 197+/-26 ms; and group III (n = 17): 224+/-46 ms. The results suggest that the AV nodal recovery curve remains unchanged once it reaches adulthood, with the exception that the nodal effective refractory period becomes slightly longer after age 60.

Attenuation of radiation dose by the skull base bone in patients with nasopharyngeal carcinoma: clinical importance

PURPOSE

To measure the degree of attenuation of radiation dose by the skull base bone in patients with nasopharyngeal carcinoma (NPC) and to study its clinical importance.

MATERIALS AND METHODS

Isodose distribution in 11 patients with NPC who received bilaterally opposed large-field irradiation (1.8 Gy per fraction) was studied with a three-dimensional treatment planning system with tissue inhomogeneity correction. Also studied were the sites of local tumor recurrence in 37 patients with NPC and skull base destruction (>/=0.5 cm) or intracranial invasion treated with radiation therapy from January 1989 to December 1992. Regression analyses were performed.

RESULTS

In the dosimetric study, the low-dose areas (<1.65 Gy) were located at the level of the skull base in all 11 patients. A significantly positive correlation between the maximum width of the skull base bone and the low-dose volume (<1.65 Gy) was demonstrated (P =.003, linear regression). In the clinical study, local tumor recurrence was noted in 18 patients (49%). The sites of local recurrence included skull base in 16 patients (43%) and nasopharynx in six patients (16%). Wider skull base bone was a significant predictor of skull base recurrence after radiation therapy (P =.03, logistic regression).

CONCLUSION

Herein demonstrated is the inadequacy of the radiation dose over the skull base due to attenuation by the skull base bone. The relationship between width of skull base bone and skull base tumor recurrence also is established.

Novel antitumor artemisinin derivatives targeting G1 phase of the cell cycle

Modification of artemisinin structure led us to the discovery of a novel class of antitumor compounds. These artemisinin derivatives containing cyano and aryl groups showed potent antiproliferative effect in vitro against P388 and A549 cells. This activity was reflected in P388 murine leukemia by an accumulation of cells in G1 phase, and induction of apoptosis.

Cell growth and gene modulatory activities of Yunzhi (Windsor Wunxi) from mushroom Trametes versicolor in androgen-dependent and androgen-insensitive human prostate cancer cells

The incidence of prostate cancer varies greatly throughout the world; it is highest in African-Americans and lowest in the Asian populations of China, India, and Japan. Geographical differences in both prevalence of latent prostate cancer and mortality have been postulated to be influenced by diverse tumor-promoting and protective factors, both environmental and dietary. Prostate cancer is a tumor with an extremely long latency; the pattern of prostate tumorigenesis, in terms of the display and sequence of appearance of particular molecular or biochemical features, or morphological changes, characterizing different stages of the carcinogenic process, is expected to be heterogeneous. Some insights into tumor heterogeneity and progression can be obtained from studies using cell lines, particularly those derived from different anatomical sites. The present study aims to investigate whether hormone-responsive LNCaP and androgen-refractory JCA-1, PC-3, and DU-145 prostate cancer cells are responsive to Yunzhi (YZ), a proprietary dietary supplement prepared from extracts of Trametes versicolor, also known as Coriolus versicolor (a mushroom consumed by Chinese for its purported health benefits), and to elucidate its mechanism of action. Ethanolic extracts (70%) of YZ significantly reduced LNCaP cell growth, down-regulated the levels of secreted PSA, but had less effects on the expression of intracellular PSA and did not affect levels of the androgen receptor. In androgen-unresponsive prostate cancer cells, YZ had a much less pronounced suppressive effect on proliferation of PC-3 and DU-145 cells, compared to LNCaP, and was inactive against JCA-1 cells. Western blot analyses show that the expression of Rb, a key regulatory protein in G1/S transition, and PCNA, integrally involved in mammalian cell DNA replication, were significantly reduced by treatment with YZ in PC-3 and DU-145 cells, respectively. In contradiction, none of these biochemical parameters were affected in JCA-1 cells under identical treatment conditions. Further analysis shows that YZ increased the levels of signal transducer and activator family of transcription factors STAT 1 and STAT 3 in JCA-1 and not LNCaP cells. The greater sensitivity of LNCaP cells to this polysaccharopeptide raises the possibility that YZ may be considered as an adjuvant therapy in the treatment of hormone responsive prostate cancer; additionally, it may have chemopreventive potential to restrict prostate tumorigenic progression from the hormone-dependent to the hormone-refractory state.

Technical innovation to calibrate the gantry angle indicators of linear accelerators

Finding the actual zero degree of the gantry angle is important in order to perform the mechanical quality assurance (QA) of linear accelerators. To determine real zero, we must locate a "good surface" which could be defined as a plane on the surface of the gantry head that is perpendicular to the direction of radiation. The actual gantry angle could then be defined as the angle between vertical, as indicated by a plumb bob, and the direction of the beam axis that could be indicated by the position of a BB placed in the central axis and its shadow. From this we located the real zero degree and the good surface. The good surface can be applied to check the important mechanical readouts. The technique we introduce could solve the essential problems of a traditional QA technique, as well as taking up an important role in the quality assurance of a patient's treatment.

Effect of resveratrol on intimal hyperplasia after endothelial denudation in an experimental rabbit model

The ability of resveratrol to inhibit vascular intimal thickening was tested in an experimental model in which endothelial denudation was performed in the normal rabbit iliac artery. Resveratrol (2 approximately 4mg/ kg/d) was administered intragastrically for 5 weeks beginning 1 week before denudation. At the higher concentration of resveratrol, the intimal hyperplasia of injured vascular wall was effectively inhibited; the intimal proliferation index also was significantly less than that in the untreated control group (0.28 +/- 0.07 vs 0.41 +/- 0.13, respectively, p<0.01); the relative luminal area increased from 0.38 +/- 0.06 in the untreated control group to 0.53 +/- 0.10 in the resveratrol treatment group (p < 0.001); and the count of smooth muscle cells in the thickened intima was statistically significantly reduced in the high dose resveratrol treatment group than that in the untreated group (1,115 +/- 510 vs 1,796 +/- 963, respectively, p < 0.05). Resveratrol added to the culture media of cultured rabbit vascular smooth muscle cells inhibited DNA synthesis in a dose-dependent manner. These results showing that resveratrol is capable of inhibiting intimal hyperplasia of injured artery raise the possibility that this polyphenol might have clinical potential in prevention and treatment of restenosis after angioplasty.

Initial low temperature setting in radiofrequency catheter ablation of Wolff-Parkinson-White syndrome

Previous studies have shown that with low temperature testing for RF ablation of arrhythmias, unnecessary irreversible myocardial lesions may be avoided. In children admitted for RF ablation from June 1996 to May 1999, we evaluated the method of an initial temperature setting of 50 degrees C for a maximum of 10 seconds. If accessory pathway block occurred, the temperature setting was immediately increased to 70 degrees C and continued for 45-120 seconds (group 1). If accessory pathway block did not occur after several attempts, subsequent attempts were made with initial settings at 70 degrees C-80 degrees C at the same or different sites (group 2). Eighty patients with Wolff-Parkinson-White syndrome (mean age 11 +/- 4 years) were treated using this method. Twelve patients were excluded for various reasons. Of the remaining 68 patients, 52 (76%) had successful block of the pathway at 50 degrees C; 16 patients demonstrated block only at the higher temperature setting of 70 degrees C-80 degrees C. There were no statistically significant differences between these two groups in terms of age, weight, and location of accessory pathways. Unsuccessful 50 degrees C test ablation attempts were 1.6 +/- 2.4 in group 1 and 3.1 +/- 2.9 in group 2 (P = 0.04). Total unsuccessful attempts were 1.6 +/- 2.4 in group 1 and 8.1 +/- 7.1 in group 2 (P = 0.001). The time from application of RF energy to the time of AP block in group 1 was not significantly different from group 2. In the majority of children, successful RF ablation can be achieved by using a temperature setting of 50 degrees C, then 70 degrees C. This will prevent unnecessary permanent injury at unsuccessful attempt sites.

Indoor air pollution and pulmonary adenocarcinoma among females: a case-control study in Shenyang, China

Factors that affect the risk of lung adenocarcinoma among females were investigated in Shenyang, China, using a population-based case-control study design. A total of 72 new cases, ages 35-69, diagnosed with incident, primary pulmonary adenocarnoma, were collected between April 1991 and December 1995, and were 1:1 age-matched with healthy females randomly selected from the general population. A questionnaire covering demographics, diet/nutritional preferences and cooking habits, living conditions, family history of cancer, sources of indoor/outdoor/occupational pollution, exposure to ETS from spousal smoking, workplace exposure, and exposure during childhood, history of menstruation and pregnancy, was given to each subject in a structured in-person interview given by trained field workers. Univariate analysis was performed on the data collected. The results showed that cooking fumes, family history of lung cancer, economic status, and number of live births and intake of vitamin E were risk factors significantly associated with adenocarcinoma of the lung. In particular, exposure to different levels of cooking fumes, an indoor air pollutant, increased the odds ratio of lung adenocarcinoma by 1.33, 7.33 and 1.67, respectively (trend p=0.006). Another important risk factor was family history of lung cancer, which gave an OR of 7.65 (95% CI, 0.90-169.84). Intake of beta-carotene from vegetables and fruit offered protection against lung adenocarcinoma, giving an OR of 0.28 (95% CI, 0.12-0.69). These results were confirmed by multivariable logistic regression analysis.

Apoptosis and restriction of G(1)/S cell cycle by fenretinide in Burkitt's lymphoma mutu I cell line accessed with bcl-6 down-regulation

Fenretinide (4-HPR) is a synthetic retinoid with cancer chemopreventative potential and clinically manageable side effects, compared to the prototype retinoid, all-trans retinoic acid (RA). 4-HPR has been shown to modulate cell proliferation and induce apoptosis in a variety of human tumor cell types, but its effects on B-cell non-Hodgkin's lymphomas (NHL-B) have not been explored. Treatment of Burkitt's lymphoma Mutu I cells with 3 microM 4-HPR is accompanied by growth arrest, induction of apoptosis, and restricted progression of the cell cycle at the G(1)/S checkpoint. We also observed that 4-HPR elicited a reduced expression of bcl-6 in these cells, which supports the proposed role of bcl-6 as an anti-apoptotic gene. While 4-HPR treatment had no effect on total Rb gene expression, it significantly reduced the state of hyperphosphorylation of Rb, resulting in the predominant existence of Rb in the underphosphorylated state.

Multivariate analysis of pulmonary fibrosis after electron beam irradiation for postmastectomy chest wall and regional lymphatics: evidence for non-dosimetric factors

BACKGROUND AND PURPOSE

To evaluate the factors associated with pulmonary fibrosis after postmastectomy electron beam irradiation of chest wall and regional lymphatics in patients with breast cancer.

MATERIALS AND METHODS

From July 1987 through July 1994, 109 women with stage II and III breast cancer receiving modified radical mastectomies were managed by postoperative electron beam irradiation. Doses of 46 to 50.4 Gy were delivered to the chest wall covered with bolus, internal mammary nodes, supraclavicular nodes and axillary lymph nodes via 12 or 15 MeV single portal electron beam. Seventeen patients received additional 10-16 Gy surgical scar boost via 9 MeV electron beam. Comparison of pre-treatment and post-treatment chest X-ray films were used to monitor the development of pulmonary fibrosis.

RESULTS

Only Grade 1 radiation-induced late pulmonary toxicity was noted in 33 patients (29%). Twenty-six patients (24%) developed pulmonary fibrosis under unbolused chest wall. Lung fibrosis under bolused chest wall was noted in 11 patients (10%). Statistical difference (P<0.01) was noted between the incidence of fibrosis in these two sites. In multivariate analysis of lung fibrosis under unbolus-covered chest wall, the independent prognostic factors are low body mass index (BMI) (P<0.01), tamoxifen taking (P=0.03), and no treatment interruption (P=0.03). No independent factor was associated with lung fibrosis under bolus-covered chest wall in multivariate analysis.

CONCLUSIONS

In the analysis of pulmonary fibrosis induced by unbolused electron beam, BMI rather than body weight and body height is a strong prognostic factor. Tamoxifen and short overall time can predispose the development of lung fibrosis.

Chinese herbal mixture PC SPES in treatment of prostate cancer (review)

The Chinese herbal preparation denoted PC SPES, a mixture consisting of extracts from eight herbs, is being used with increasing frequency by prostate cancer patients worldwide. Evidence has emerged that PC SPES is an effective modality that alleviates some symptoms in advanced prostate cancer in a significant proportion of patients including the cases that failed conventional therapy. This evidence as well as published data that show the effects of PC SPES in suppressing growth of prostate cancer in animal model studies, is reviewed together with the available data on the possible side effects of PC SPES. The review also covers in vitro studies that reveal the cell cycle specificity, induction of apoptosis, effects on androgen receptor and other molecular and metabolic changes induced by PC SPES that may explain its anticancer activity. Individual chemical components that are present in herbs of which PC SPES is composed, known to have anti-proliferative, antitumor, antimutagenic, analgesic and/or differentiation inducing activity, are listed and discussed. The effectiveness of PC SPES in prostate cancer is explained as due to its complex composition which may target many signal transduction and metabolic pathways simultaneously thereby eliminating the back-up or redundant mechanisms that otherwise promote cell survival when single-target agents are used.

Ectopic atrial tachycardia in children

BACKGROUND AND PURPOSE

Ectopic atrial tachycardia (EAT) is an unusual and potentially risky arrhythmia that can result in left ventricular dysfunction if not properly managed. In adults, EAT is mainly caused by diseased atrial myocardium and responds poorly to antiarrhythmic drugs. The characteristics of EAT in children might be different from those in adults because of their immature myocardium and the different electrophysiologic characteristics of their conduction tissue. We examined the natural history and treatment of EAT in children.

METHODS AND RESULTS

From June 1990 through June 1999, 24 children (8 girls and 16 boys; median age 4 mo [1 d-10 yr]) were admitted to our hospital with a diagnosis of EAT. Fifteen had healthy hearts, six had congenital heart disease, one had myocarditis, one had bronchopulmonary dysplasia with severe pulmonary hypertension, and one had hypertrophic cardiomyopathy. Thirteen patients presented with congestive heart failure. Only four patients had symptoms of prodromal airway infection. The maximum atrial rate was 244 +/- 66 beats per minute. Atrioventricular block was documented at least once during tachycardia in 10 patients. Warm-up or cool-down phenomenon was seen at the initiation or termination of tachycardia in thirteen patients. Primary pharmacologic treatment was attempted in all patients. EAT was initially controlled in all patients using digoxin plus propranolol (18 patients), propranolol only (4), or digoxin plus procainamide (2). EAT was controlled using medication in 22 patients. Fifteen patients had sinus rhythm but did not receive medication for 39 +/- 25 months. Two patients died of uncontrolled arrhythmia, and two of underlying disease. Recurrence was seen within 3 months after initial therapy in five patients. Surgery was performed to correct the underlying heart disease in three patients with frequently recurring EAT, all of whom remained tachycardia-free after surgery, without pharmacologic treatment. The spontaneous remission rate was 75% (18/24).

CONCLUSION

EAT in children without underlying heart disease can be effectively treated using antiarrhythmic drugs. Spontaneous resolution of EAT after medication in children was frequent (75%) in this series. The results of this study suggest that a step-wise approach using digoxin, a beta-blocker, and a class I antiarrhythmic drug may be the most effective treatment for EAT.