Dimeric 3,5-Bis(benzylidene)-4-piperidones: Tumor-Selective Cytotoxicity and Structure-Activity Relationships.

Background: The objective of this study is to find novel antineoplastic agents that display greater toxicity to malignant cells than to neoplasms. In addition, the mechanisms of action of representative compounds are sought. This report describes the cytotoxicity of a number of dimers of 3,5-bis(benzylidene)-4-piperidones against human malignant cells (promyelocytic leukemia HL-60 and squamous cell carcinoma HSC-2, HSC-3, and HSC-4). Methods: Tumor specificity was evaluated by the selectivity index (SI), that is the ratio of the mean CC50 for human non-malignant oral cells (gingival fibroblasts, pulp cells, periodontal ligament fibroblasts) to that for malignant cells. Results: The compounds were highly toxic to human malignant cells. On the other hand, these molecules were less toxic to human non-malignant cells. In particular, a potent lead molecule, 3b, was identified. A QSAR study revealed that the placement of electron-releasing and hydrophilic substituents into the aryl rings led to increases in cytotoxic potencies. The modes of action of a lead compound discovered in this study designated 3b were the activation of caspases-3 and -7, as well as causing PARP1 cleavage and G2 arrest, followed by sub-G1 accumulation in the cell cycle. This compound also depolarized the mitochondrial membrane and generated reactive oxygen species in human colon carcinoma HCT116 cells. In conclusion, this study has revealed that, in general, the compounds described in this report are tumor-selective cytotoxins.

A generalized likelihood ratio test for monitoring profile data.

Profile data emerges when the quality of a product or process is characterized by a functional relationship among (input and output) variables. In this paper, we focus on the case where each profile has one response variable Y, one explanatory variable x, and the functional relationship between these two variables can be rather arbitrary. The basic concept can be applied to a much wider case, however. We propose a general method based on the Generalized Likelihood Ratio Test (GLRT) for monitoring of profile data. The proposed method uses nonparametric regression to estimate the on-line profiles and thus does not require any functional form for the profiles. Both Shewhart-type and EWMA-type control charts are considered. The average run length (ARL) performance of the proposed method is studied. It is shown that the proposed GLRT-based control chart can efficiently detect both location and dispersion shifts of the on-line profiles from the baseline profile. An upper control limit (UCL) corresponding to a desired in-control ARL value is constructed.

Designs for order-of-addition experiments.

The order-of-addition experiment aims at determining the optimal order of adding components such that the response of interest is optimized. Order of addition has been widely involved in many areas, including bio-chemistry, food science, nutritional science, pharmaceutical science, etc. However, such an important study is rather primitive in statistical literature. In this paper, a thorough study on pair-wise ordering designs for order of addition is provided. The recursive relation between two successive full pair-wise ordering designs is developed. Based on this recursive relation, the full pair-wise ordering design can be obtained without evaluating all the orders of components. The value of the D-efficiency for the full pair-wise ordering model is then derived. It provides a benchmark for choosing the fractional pair-wise ordering designs. To overcome the unaffordability of the full pair-wise ordering design, a new class of minimal-point pair-wise ordering designs is proposed. A job scheduling problem as well as simulation studies are conducted to illustrate the performance of the pair-wise ordering designs for determining the optimal orders. It is shown that the proposed designs are very efficient in determining the optimal order of addition.

PM2.5 and ozone, indicators of air quality, and acute deaths in California, 2004-2007.

Since the London Great Smog of 1952 was estimated to have killed over 4000 people, scientists have studied the relationship between air quality and acute mortality. Currently, the association between air quality and acute deaths is usually taken as evidence for causality. As air quality has markedly improved since 1952, do contemporary datasets support this view? We use a large dataset, eight air basins in California for the years 2004-2007, to examine the possible association of ozone and PM2.5 with acute deaths after statistically removing seasonal and weather effects. Our analysis dataset is available on request. We conducted a regression-corrected, case-crossover analysis for all non-accidental deaths age 75 and older. We used stepwise regression to examine three causes of death. After seasonal and weather adjustments, there was essentially no predictive power of ozone or PM2.5 for acute deaths. The case-crossover analysis produced odds ratio very close to 1.000 (no effect). The very narrow confidence limits indicated good statistical power. We study recent air quality in both time-stratified, symmetric, bidirectional case-crossover and time series regression and both give consistent results. There is no statistically significant association between either ozone or PM2.5 and acute human mortality. In the absence of an association, causality is in question.

Time series smoother for effect detection.

In environmental epidemiology, it is often encountered that multiple time series data with a long-term trend, including seasonality, cannot be fully adjusted by the observed covariates. The long-term trend is difficult to separate from abnormal short-term signals of interest. This paper addresses how to estimate the long-term trend in order to recover short-term signals. Our case study demonstrates that the current spline smoothing methods can result in significant positive and negative cross-correlations from the same dataset, depending on how the smoothing parameters are chosen. To circumvent this dilemma, three classes of time series smoothers are proposed to detrend time series data. These smoothers do not require fine tuning of parameters and can be applied to recover short-term signals. The properties of these smoothers are shown with both a case study using a factorial design and a simulation study using datasets generated from the original dataset. General guidelines are provided on how to discover short-term signals from time series with a long-term trend. The benefit of this research is that a problem is identified and characteristics of possible solutions are determined.

Safety and performance benefits of arginine supplements for military personnel: a systematic review.

CONTEXT: Dietary supplements are widely used by military personnel and civilians for promotion of health. OBJECTIVE: The objective of this evidence-based review was to examine whether supplementation with l-arginine, in combination with caffeine and/or creatine, is safe and whether it enhances athletic performance or improves recovery from exhaustion for military personnel. DATA SOURCES: Information from clinical trials and adverse event reports were collected from 17 databases and 5 adverse event report portals. STUDY SELECTION: Studies and reports were included if they evaluated the safety and the putative outcomes of enhanced performance or improved recovery from exhaustion associated with the intake of arginine alone or in combination with caffeine and/or creatine in healthy adults aged 19 to 50 years. DATA EXTRACTION: Information related to population, intervention, comparator, and outcomes was abstracted. Of the 2687 articles screened, 62 articles meeting the inclusion criteria were analyzed. Strength of evidence was assessed in terms of risk of bias, consistency, directness, and precision. RESULTS: Most studies had few participants and suggested risk of bias that could negatively affect the results. l-Arginine supplementation provided little enhancement of athletic performance or improvements in recovery. Short-term supplementation with arginine may result in adverse gastrointestinal and cardiovascular effects. No information about the effects of arginine on the performance of military personnel was available. CONCLUSIONS: The available information does not support the use of l-arginine, either alone or in combination with caffeine, creatine, or both, to enhance athletic performance or improve recovery from exhaustion. Given the information gaps, an evidence-based review to assess the safety or effectiveness of multi-ingredient dietary supplements was not feasible, and therefore the development of a computational model-based approach to predict the safety of multi-ingredient dietary supplements is recommended.

Asymptotics of nonparametric L-1 regression models with dependent data.

We investigate asymptotic properties of least-absolute-deviation or median quantile estimates of the location and scale functions in nonparametric regression models with dependent data from multiple subjects. Under a general dependence structure that allows for longitudinal data and some spatially correlated data, we establish uniform Bahadur representations for the proposed median quantile estimates. The obtained Bahadur representations provide deep insights into the asymptotic behavior of the estimates. Our main theoretical development is based on studying the modulus of continuity of kernel weighted empirical process through a coupling argument. Progesterone data is used for an illustration.

Evidence-based evaluation of potential benefits and safety of beta-alanine supplementation for military personnel.

This Department of Defense-sponsored evidence-based review evaluates the safety and putative outcomes of enhancement of athletic performance or improved recovery from exhaustion in studies involving beta-alanine alone or in combination with other ingredients. Beta-alanine intervention studies and review articles were collected from 13 databases, and safety information was collected from adverse event reporting portals. Due to the lack of systematic studies involving military populations, all the available literature was assessed with a subgroup analysis of studies on athletes to determine if beta-alanine would be suitable for the military. Available literature provided only limited evidence concerning the benefits of beta-alanine use, and a majority of the studies were not designed to address safety. Overall, the strength of evidence in terms of the potential for risk of bias in the quality of the available literature, consistency, directness, and precision did not support the use of beta-alanine by military personnel. The strength of evidence for a causal relation between beta-alanine and paresthesia was moderate.

Novel 3,5-bis(arylidene)-4-oxo-1-piperidinyl dimers: structure-activity relationships and potent antileukemic and antilymphoma cytotoxicity.

Novel clusters of 3,5-bis(benzylidene)-4-oxo-1-piperidinyl dimers 3-5 were evaluated against human Molt4/C8 and CEM T-lymphocytes and human HeLa cervix adenocarcinoma cells as well as murine L1210 leukemia neoplasms. Several of these compounds demonstrated IC50 values in the submicromolar and low micromolar range and compounds possessing 4-fluoro, 4-chloro and 3,4,5-trimethoxy substituents in the series 3 and 4 were identified as potent molecules. A heat map revealed the very high cytotoxic potencies of representative compounds against a number of additional leukemic and lymphoma cell lines and displayed greater toxicity to these cells than nonmalignant MCF10A and Hs-27 neoplasms. These dienones are more refractory to breast and prostate cancers. The evaluation of representative compounds in series 3-5 against a panel of human cancer cell lines revealed them to be potent cytotoxins with average IC50 values ranging from 0.05 to 8.51 µM. In particular, the most potent compound 4g demonstrated over 382-fold and 590-fold greater average cytotoxic potencies in this screen than the reference drugs, melphalan and 5-fluorouracil, respectively. A mode of action investigation of two representative compounds 3f and 4f indicated that they induce apoptosis which is due, at least in part, to the activation of caspase-3 and depolarization of the mitochondrial membrane potential.

Novel 3,5-bis(arylidene)-4-piperidone dimers: potent cytotoxins against colon cancer cells.

Two novel series of dimeric 3,5-bis(arylidene)-4-piperidones 7 and 8 were prepared as cytotoxic agents. A specific objective of this study was the discovery of novel compounds displaying potent anti-proliferative activities against colon cancers. Most of the compounds demonstrate potent cytotoxicity against HCT116 and HT29 colon cancer cell lines in which the IC50 values range from low micromolar to nanomolar values. In general, the majority of the compounds showed greater cytotoxicity and some degree of selectivity toward HCT116 cells compared to HT29 cells. Compound 9 in which the amidic carbonyl groups were excised was substantially less potent than 8a in both cell lines suggested that the amide groups are important components of the molecules for exhibiting cytotoxicity. Virtually all the compounds were more potent than a reference drug 5-fluorouracil which is used in treating colon cancers as well as a related enone curcumin. QSAR studies were undertaken and some guidelines for amplification of the project have been formulated. Flow cytometry analysis of a representative potent compound 7f revealed that it induces apoptosis in HCT116 cells.

Dimeric 3,5-bis(benzylidene)-4-piperidones: a novel cluster of tumour-selective cytotoxins possessing multidrug-resistant properties.

A series of bis[3,5-bis(benzylidene)-4-oxo-1-piperidinyl]amides 1 display potent cytotoxic properties towards a wide range of tumours. A number of the CC(50) and IC(50) values are in the range of 10(-8) M. Specifically, these compounds have the following important properties. First, greater toxicity was demonstrated towards certain tumours than various non-malignant cells. Second, various compounds in series 1 are toxic to a number of human colon cancer and leukaemic cells. Third, these compounds reverse P-gp mediated multidrug resistance. Various prototypic molecules such as 1a,b and 1i were identified as lead molecules for further studies. A representative lead molecule 1b induces apoptosis via internucleosomal DNA fragmentation and PARP cleavage in HSC-2 and HL-60 cells while flow cytometry revealed that this compound blocked the G2/M and S-phases in the cell cycle of human colon cancer HCT-116 cells.

PROFILE CONTROL CHARTS BASED ON NONPARAMETRIC L-1 REGRESSION METHODS.

Classical statistical process control often relies on univariate characteristics. In many contemporary applications, however, the quality of products must be characterized by some functional relation between a response variable and its explanatory variables. Monitoring such functional profiles has been a rapidly growing field due to increasing demands. This paper develops a novel nonparametric L-1 location-scale model to screen the shapes of profiles. The model is built on three basic elements: location shifts, local shape distortions, and overall shape deviations, which are quantified by three individual metrics. The proposed approach is applied to the previously analyzed vertical density profile data, leading to some interesting insights.

Bis[3,5-bis(benzylidene)-4-oxo-1-piperidinyl]amides: a novel class of potent cytotoxins.

The principal objective of this study was the examination of the theory of cytotoxic synergism. In this exploratory study, we tested the hypothesis that doubling the number of sites available for thiol alkylation in a series of candidate cytotoxins increases potency more than two-fold. This concept was verified in one-third of our comparisons using human Molt 4/C8 and CEM T-lymphocytes and murine L1210 cells. In addition, the significant potencies of various members of our compound series justified further studies. Molecular modeling revealed that relative locations of the amidic groups correlate with cytotoxicity. A potent cytotoxic compound, 1,2-bis(3,5-dibenzylidene-4-oxo-piperidin-1-yl)ethane-1,2-dione (1a) inhibited the growth of a large number of human tumor cell lines and displayed greater toxicity toward certain non-adherent cells than toward adherent neoplasms or fibroblasts. The mode of action of 1a includes induction of apoptosis and necrosis.

Sequential cytotoxicity: a theory examined using a series of 3,5-bis(benzylidene)-1-diethylphosphono-4-oxopiperidines and related phosphonic acids.

The concept of sequential cytotoxicity, which states that successive chemical attacks on cellular constituents can be more deleterious to neoplasms than normal cells, was evaluated using a series of 3,5-bis(benzylidene)-1-diethylphosphono-4-oxopiperidines 1 and related phosphonic acids 2, which were screened against a panel of malignant and normal cell lines. The compounds proved to be not only potent cytotoxins (71% of the CC(50) figures are submicromolar) but to display greater cytotoxicity to the neoplastic cells. QSAR revealed that both cytotoxic potencies and selective toxicity were increased by a rise in the electron-withdrawing properties and a decrease in the hydrophobicity of the aryl substituents. Utilisation of the PL10 concept and evaluation of druglike properties revealed 1c as the lead tumour-specific cytotoxin. This molecule activated caspase-3 in HL-60 cells but not in the HSC-2 cell line. While 1c caused internucleosomal DNA fragmentation in HL-60 cells, it did not elicit this effect in either HSC-2 and HSC-4 cells. Clearly 1c exerts its cytotoxic potencies by different mechanisms and such pleiotropy is likely the principal reason for the remarkable display of preferential toxicity towards malignant cells of the compounds in series 1 and 2.

E-2-[3-(3,4-dichlorophenyl)-1-oxo-2-propenyl]-3-methylquinoxaline-1,4-dioxide: a lead antitubercular agent which alters mitochondrial respiration in rat liver.

A series of 2-(3-aryl-1-oxo-2-propenyl)-3-methylquinoxaline-1,4-dioxides 1a-l and 2-acetyl-3-methylquinoxaline-1,4-dioxide 2 were evaluated against Mycobacterium tuberculosis H(37)Rv. With the exception of the 4-nitro analog 1k, significant antitubercular potencies were observed in series 1 and 2 which have IC(50) values in the range of 1-23 microM. Negative correlations were noted between the IC(50) values of 1a-j, l towards M. tuberculosis and both the sigma and pi constants of the substituents in the benzylidene aryl ring. In particular, 1h emerged as a lead compound having IC(50) and IC(90) figures of 1.03 microM and 1.53 microM, respectively. This molecule affected respiration in rat liver mitochondria which is likely one way that 1h and the bioactive analogs exert their antitubercular properties. The quinoxaline 2, which lacks an alpha,beta-unsaturated group, has no effect on mitochondrial respiration using concentrations which inhibit the growth of M. tuberculosis.

3,5-Bis(benzylidene)-4-oxo-1-phosphonopiperidines and related diethyl esters: Potent cytotoxins with multi-drug-resistance reverting properties.

A series of 3,5-bis(benzylidene)-4-piperidones 3 were converted into the corresponding 3,5-bis(benzylidene)-1-phosphono-4-piperidones 5 via diethyl esters 4. The analogues in series 4 and 5 displayed marked growth inhibitory properties toward human Molt 4/C8 and CEM T-lymphocytes as well as murine leukemia L1210 cells. In general, the N-phosphono compounds 5, which are more hydrophilic than the analogues in series 3 and 4, were the most potent cluster of cytotoxins, and, in particular, 3,5-bis-(2-nitrobenzylidene)-1-phosphono-4-piperidone 5 g had an average IC(50) value of 34 nM toward the two T-lymphocyte cell lines. Four of the compounds displayed potent cytotoxicity toward a panel of nearly 60 human tumor cell lines, and nanomolar IC(50) values were observed in a number of cases. The mode of action of 5 g includes the induction of apoptosis and inhibition of cellular respiration. Most of the members of series 4 as well as several analogues in series 5 are potent multi-drug resistance (MDR) reverting compounds. Various correlations were noted between certain molecular features of series 4 and 5 and cytotoxic properties, affording some guidelines in expanding this study.

Variable Selection for Screening Experiments.

The first step in many applications of response surface methodology is typically the screening process. Variable selection plays an important role in screening experiments when a large number of potential factors are introduced in a preliminary study. Traditional approaches, such as the best subset variable selection and stepwise deletion, may not be appropriate in this situation. In this paper we introduce a variable selection procedure via penalized least squares with the SCAD penalty. An algorithm to find the penalized least squares solution is suggested, and a standard error formula for the penalized least squares estimate is derived. With a proper choice of the regularization parameter, it is shown that the resulting estimate is root n consistent and possesses an oracle property; namely, it works as well as if the correct submodel were known. An automatic and data-driven approach was proposed to select the regularization parameter. Examples are used to illustrate the effectiveness of the newly proposed approach. The computer codes (written in MATLAB) to perform all calculation are available through the authors for an automatic data-driven variable selection procedure.

Adjuvant activities of saponins from the root of Polygala senega L.

Eight pure triterpenoid saponin compounds isolated from the root of Polygala senega L., a plant indigenous to the Canadian prairies, were evaluated for their immunological activity in mouse models. The specific antibody responses of the IgG2a subclass increased significantly when isolated P. senega saponins were used as adjuvants in the immunization of mice with OVA antigen. In addition, increased IL-2 levels were observed in spleen cell cultures from P. senega saponin-immunized mice after in vitro secondary antigen stimulation. The saponins were tested for their toxicity in mice by using a haemolytic activity assay and found to be less toxic than Quillaja saponaria saponins that have long been used as adjuvants in vaccine formulations. This study has shown the potential of P. senega saponins to be considered as a natural source of vaccine adjuvants with biological activity equivalent to the current commercially available saponin adjuvants.

A paradox of cerebral hyperperfusion in the face of cerebral hypotension: the effect of perfusion pressure on cerebral blood flow and metabolism during normothermic cardiopulmonary bypass.

BACKGROUND: The purpose of this study was to determine the impact of perfusion pressure on cerebral blood flow (CBF) and metabolism during normothermic cardiopulmonary bypass (CPB) and after weaning. MATERIALS AND METHODS: Two groups of mongrel dogs were studied (Group A, CPB perfusion at 50 mm Hg, n = 6; and Group B, CPB perfusion at 100 mm Hg, n = 6). All animals underwent 2 h of normothermic bypass at cardiac indexes >2.1 L/min/m2 and were weaned from pump, maintained at pressures >75 mm Hg, and followed for an additional 2 h. RESULTS: In both groups CBF increased over 85% from baseline, in proportion to the hemodilution during the initiation of CPB. Intracranial pressure increased moderately in both groups during CPB, compromising CBF at 1 h in Group A, but not in Group B. The Group A cerebral metabolic rate for oxygen (CMRO2), however, remained unchanged as the percentage of oxygen extraction increased to compensate for the decreased CBF. During recovery, temperature, mean arterial pressure, and cerebral perfusion pressure were not significantly different between the two groups. However, the CBF, percentage of oxygen extracted, and CMRO2 were significantly lower in Group A. CONCLUSIONS: Normothermic CPB initiated with a crystalloid prime and performed at the lower end of a 50-70 mm Hg perfusion window resulted in a highly significant increase in CBF in order to compensate for hemodilution, while at the same time reduced the perfusion pressure available to supply the increased CBF. Together, these two events create a hemodynamic paradox of hyperperfusion in the face of hypotension. The reduction in CMRO2 in Group A is yet to be explained but seems to remain coupled to CBF and could represent a previously undescribed protective mechanism of hibernating cerebral tissue, similar to the phenomena of ischemic preconditioning in the heart, where cerebral tissue is stimulated to lower metabolism in response to inadequate CBF.

Osteolysis versus osteomyelitis: a clinical case report.

Differentiating osteolysis and osteomyelitis is a formidable challenge for even the most experienced clinician. Although the two may have a similar presentation, the treatment regimen, morbidity, and long term prognosis for the patient are vastly dissimilar. The diagnosis of osteomyelitis carries with it a need for immediate and decisive action that may include early aggressive amputation. Conversely, the diagnosis of osteolysis necessitates a patient, conservative approach so as not to "burn any bridges", and to allow time for the affected part to heal.