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PubMed1998

Double blind test of magnetic field effects on neurite outgrowth.

Previous work reported that nerve growth factor-stimulated neurite outgrowth in PC-12 cells could be altered by exposure to parallel alternating current (AC) and direct current (DC) magnetic fields under a variety of exposure conditions, producing results that are consistent with the predictions of the ion parametric resonance (IPR) model. The credibility of these results, considered extraordinary by some scientists, could be strengthened if the cell response were found to persist under alternate assay conditions. We replaced part of our standard assay procedure with a double blind procedure. This new procedure obscured 1) whether a particular set of dishes of cells was exposed or not, and 2) which individual dish was in which exposure system. The goal was to determine whether the previously observed responses of PC-12 cells to magnetic fields would be sufficiently robust to decode the imposed blinding, thereby removing any question of experimenter bias in reported results. We placed three coded dishes of cells in each of two otherwise identical exposure systems, one not energized and one energized to produce exposure conditions predicted to maximally suppress neurite outgrowth (Bdc of 36.6 microT, parallel 45 Hz AC of 23.8 microT rms). Each of the six dishes were recoded before assay to further obscure the exposure identity of any individual dish. The combined results of four distinct runs of these double blind experiments unequivocally demonstrated that 1) there was a clear, distinctive, repeatable consistency with the actual energization of the exposure systems and location of each dish, and with the predictions of the IPR model; 2) only the explicitly stated experimental variables influenced the experiment; and 3) the reported response of the cells was very improbably due to chance (P = .000024).

Animals↗
PubMed1989

Computing multiple cell kinetic properties from a single time point.

New developments in experimental procedures have made it necessary to extend the theory for describing the movement of a population of cells and estimating the kinetic properties of the population. The new procedures are based on the use of fluorescent monoclonal antibodies to halogenated analogues of thymidine, which are incorporated as a label into cells during DNA synthesis. These populations may be examined by dual-parameter flow cytometry to discriminate between the labelled and unlabelled populations of cells and define their position within the DNA reproductive cycle. A particular need exists for a theory that can be used for measurements of tumors in which many cells are not actively cycling and only a single time point can be obtained. In order to develop a useful theory for evaluating the kinetic properties of the cells observed by these techniques, the standard methods of theoretical cell kinetics have been recast in a form that is amenable to the type of analysis demanded by these constraints and a novel method for the rapid analysis of the kinetic properties of the cell population is presented. The method is shown to yield a direct measurement for the population doubling time from a single time point as well as estimates for the transit times through each phase of the cell cycle. The method which is approximately linear is shown to be robust to the effects of different assumptions about the distribution of transit times as well as being insensitive to the effects of variation in the transit times of the cells. The methodology developed in this paper may also be used to examine other theoretical methods of computing kinetic properties.

Cell Cycle↗
PubMed1997

Energy-transfer fluorescent reagents for DNA analyses.

Fluorescence resonance energy transfer has facilitated the development of a new class of high-performance fluorescent labeling reagents for multiplex analyses of nucleic acids. The enhanced emission of energy transfer (ET) primers has provided a decadic improvement in the performance of automated DNA sequencers. The emission spectral purity of ET primers permits the development of robust multiplex diagnostic methods for the detection of PCR products. High affinity bifunctional intercalation reagents containing ET-coupled dyes are also being used for high-performance multiplex assays of double-stranded DNA when noncovalent labeling is preferred.

Base Sequence↗
PubMed2006

Efficacy and mechanisms of action of lithium augmentation in refractory major depression.

Lithium augmentation refers to the addition of lithium to an antidepressant in the acute treatment phase of patients with depressive episodes who have failed to respond satisfactorily to treatment with antidepressant monotherapy. This article reviews the clinical evidence and hypotheses on the mode of action of lithium augmentation. For this purpose, studies were identified by searching Medline and by scanning the references of published reviews and standard textbooks. With regard to efficacy, 28 prospective studies (with a total of 838 depressed patients) were identified. The majority of randomized controlled trials has demonstrated substantial efficacy of lithium augmentation. A recent meta-analysis including only double-blind, placebo-controlled trials (N = 9) provided firm evidence that lithium augmentation has a statistically significant effect on response rate compared to placebo, and showed that lithium augmentation should be administered for at least 2 weeks to allow assessment of the patient's response. A recent double-blind, placebo-controlled trial revealed that responders to lithium augmentation should be maintained on the lithium-antidepressant combination for a minimum of 12 months. From animal studies there is robust evidence that lithium augmentation increases serotonin (5-HT) neurotransmission, possibly through a synergistic action of lithium and the antidepressant on brain 5-HT pathways. Neuroendocrine studies in humans on the effects of lithium augmentation on the HPA system showed an unexpected and marked increase in the ACTH and cortisol response in the combined dexamethasone/CRH test. These results are in contrast to the established decline of HPA system activity during treatment with antidepressants. In conclusion, lithium is the foremost and most well-documented augmentation strategy in refractory depression. In international treatment guidelines and algorithms, lithium augmentation is considered a first-line treatment strategy for patients with a major depressive episode who do not adequately respond to standard antidepressant treatment.

Animals↗
PubMed2001

Divalproex sodium in alcohol withdrawal: a randomized double-blind placebo-controlled clinical trial.

BACKGROUND: Divalproex sodium, an anticonvulsant and antikindling agent and gamma-aminobutyric acid enhancer, has been proposed as an alternative to benzodiazepines for treating alcohol withdrawal. This study reports on a randomized, double-blind, placebo-controlled trial of divalproex sodium in acute alcohol withdrawal. METHODS: Thirty-six hospitalized patients experiencing moderate alcohol withdrawal as measured by a score of at least 10 on the revised Clinical Institute Withdrawal Assessment for Alcohol Scale (CIWA-Ar) were randomized to receive either divalproex sodium 500 mg three times per day for 7 days or matched placebo in a double-blind manner. All subjects received a baseline dose of oxazepam and had additional oxazepam available as a rescue medication in accordance with a standard, symptom-triggered detoxification protocol. Mean total milligrams of oxazepam received, progression of withdrawal symptoms, psychological distress as measured by the Symptom Checklist-90, side effects, and adverse outcomes were compared between groups. RESULTS: Use of divalproex sodium resulted in less use of oxazepam (p < 0.033). Group differences seemed primarily driven by those subjects who experienced symptoms above threshold level (CIWA-Ar >or=10) after 12 hr. The progression in severity of withdrawal symptoms (increase in CIWA-Ar above baseline) was also significantly greater in the placebo group (p < 0.05). CONCLUSIONS: This placebo-controlled pilot study suggests that divalproex sodium significantly affects the course of acute alcohol withdrawal and reduces the need for treatment with a benzodiazepine. A more aggressive loading dose strategy may demonstrate a more robust or earlier response.

Adolescent↗
PubMed1988

Lactate- and isoproterenol-induced panic attacks in panic disorder patients and controls.

In a double-blind study using sodium lactate and isoproterenol infusions to provoke panic attacks, 73 of 86 panic disorder patients and 10 of 45 controls panicked with lactate, and 58 of 86 patients and 4 of 45 controls panicked with isoproterenol. We measured baseline and peak anxiety ratings in 10 controls with lactate-induced panic attacks, 31 controls who did not panic during lactate infusions, and 63 panic disorder patients who did panic during lactate infusions. The controls who panicked with lactate had robust increases in their anxiety ratings very similar to the increases experienced by patients who panicked with lactate.

Adolescent↗
PubMed2005

A large, double-blind, randomized clinical trial of methylphenidate in the treatment of adults with attention-deficit/hyperactivity disorder.

BACKGROUND: The few controlled studies of methylphenidate (MPH) in adults with attention deficit/hyperactivity disorder (ADHD) have reported equivocal results. A previous, pilot study by our group suggested that these results were due to inadequate dosing. METHOD: We conducted a randomized, 6-week, placebo-controlled, parallel study of MPH in 146 adult patients with DSM-IV ADHD using standardized instruments for diagnosis, separate assessments of ADHD, depressive and anxiety symptoms, and a robust average oral daily dose of 1.1 mg/kg/day. RESULTS: We found a marked therapeutic response for the MPH treatment of ADHD symptoms that exceeded the placebo response (76% vs. 19%). Treatment was safe and well tolerated. Response to MPH was independent of socioeconomic status, gender, and lifetime history of psychiatric comorbidity. CONCLUSIONS: These results confirm that robust doses of MPH are effective in the treatment of adult ADHD.

Adult↗
PubMed2006

[Acquired tumor "robustness" in the case of prostate cancer].

Tumors are highly robust and maintain their proliferative potential against both a wide range of host-defense mechanisms and anticancer therapies. In this study, we investigated the levels of human leukocyte antigen (HLA) class I, multi-drug resistance 1 (MDR1), and androgen receptor (AR) expressions in untreated prostate cancers harvested by radical prostectomy. The mean percentages of cancer cells expressing HLA class I, MDR1, and AR among the 10 cancer samples were 41, 35, and 74%, respectively. In addition, double-staining of HLA class I and MDR1 revealed the four definite populations (HLA class I(+)/MDR(+), HLA class I(+)/MDR(-), HLA class I (-)/MDR(+), and HLA class I(-)/MDR(-)) in cancer tissues from the majority of cancer patients tested, and the mean percentages of cells expressing these combinations were 13, 29, 22, and 38%, respectively. Similar results were obtained by double staining of HLA class I and AR, except for 2 cases in which HLA class I(-)/AR (+) cancer cells predominated. These results indicated that untreated prostate cancer cells acquired a wide range of genomic mutation, which may have been caused by internal host pressure to eliminate malignant cells, and would provide evidence of the robustness of untreated prostate cancer.

Aged↗
PubMed1998

Imipramine treatment of opiate-dependent patients with depressive disorders. A placebo-controlled trial.

BACKGROUND: The literature is inconclusive on the role of antidepressant medications in treating drug dependence. Studies have either not focused on depressed patients or have selected patients with depressive disorders based on cross-sectional symptoms rather than a syndromal diagnosis. A clinical trial of an antidepressant was, therefore, conducted on drug-dependent patients with syndromal depression. METHODS: Patients receiving methadone hydrochloride maintenance treatment were selected if they met the criteria for a DSM-III-R depressive disorder that was chronologically primary, had persisted during a past abstinent period or was long-standing, and persisted during at least 1 month of stable methadone treatment. Subjects were randomized to a 12-week, double-blind, placebo-controlled trial of imipramine hydrochloride. A favorable response was defined as a Clinical Global Impression scale score for depression of 2 ("much improved") or 1 ("very much improved") and at least a 75% reduction in self-reported drug or alcohol use or abstinence. RESULTS: One hundred thirty-seven patients were randomized, and 84 completed a minimum adequate trial of at least 6 weeks. Among the 84 adequately treated patients, 57% (24/42) receiving imipramine were rated as responders compared with 7% (3/42) receiving placebo (P < .001). On measures of mood, there was a robust effect of imipramine. Imipramine was superior to placebo on some self-reported measures of substance use and craving, and mood improvement was associated with improvement in self-reported substance use. However, few patients achieved urine-confirmed abstinence. CONCLUSIONS: Imipramine was an effective antidepressant in patients receiving methadone who were selected via syndromal criteria for depressive illness. Imipramine may reduce substance abuse among patients whose mood improves; however, this effect was less robust.

Adult↗
PubMed2002

Clock mechanisms in Drosophila.

Mechanisms underlying circadian clock function in Drosophila melanogaster have been revealed by genetic and molecular approaches. Two interlocked transcriptional feedback loops involving at least the period, timeless, Clock,and cycle genes generate molecular oscillations that are believed to control behavioral rhythmicity and other clock outputs. These oscillations are further enhanced and fine-tuned to match the duration of the solar day by post-transcriptional and post-translational mechanisms depending on the PERIOD and TIMELESS proteins and on the protein kinases DOUBLE-TIME and SHAGGY. Light is the principal zeitgeber for synchronizing molecular and behavioral rhythmicity via the blue-light photoreceptor CRYPTOCHROME and the TIMELESS protein. In addition, light seems required for maintaining robust molecular oscillations at least in peripheral clock-gene-expressing tissues like the eyes, antennae, or Malpighian tubules. Relaying temporal information to cells and tissues expressing overt biological rhythms involves regulation of "output genes" at multiple levels. Although their regulation depends on the major clock genes, the majority of the clock-controlled genes are not direct targets of clock factors.

Animals↗
PubMed2004

Glial cell line-derived neurotrophic factor is essential for neuronal survival in the locus coeruleus-hippocampal noradrenergic pathway.

It has been shown that the noradrenergic (NE) locus coeruleus (LC)-hippocampal pathway plays an important role in learning and memory processing, and that the development of this transmitter pathway is influenced by neurotrophic factors. Although some of these factors have been discovered, the regulatory mechanisms for this developmental event have not been fully elucidated. Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor influencing LC-NE neurons. We have utilized a GDNF knockout animal model to explore its function on the LC-NE transmitter system during development, particularly with respect to target innervation. By transplanting various combinations of brainstem (including LC) and hippocampal tissues from wildtype or GDNF knockout fetuses into the brains of adult wildtype mice, we demonstrate that normal postnatal development of brainstem LC-NE neurons is disrupted as a result of the GDNF null mutation. Tyrosine hydroxylase immunohistochemistry revealed that brainstem grafts had markedly reduced number and size of LC neurons in transplants from knockout fetuses. NE fiber innervation into the hippocampal co-transplant from an adjacent brainstem graft was also influenced by the presence of GDNF, with a significantly more robust innervation observed in transplants from wildtype fetuses. The most successful LC/hippocampal co-grafts were generated from fetuses expressing the wildtype GDNF background, whereas the most severely affected transplants were derived from double transplants from null-mutated fetuses. Our data suggest that development of the NE LC-hippocampal pathway is dependent on the presence of GDNF, most likely through a target-derived neurotrophic function.

Animals↗
PubMed2004

Methylphenidate treatment of attention-deficit/hyperactivity disorder secondary to traumatic brain injury: a critical appraisal of treatment studies.

OBJECTIVE: Are stimulants effective in treating attention-deficit/hyperactivity disorder secondary to traumatic brain injury (ADHD/TBI)? The authors reviewed and examined the current knowledge on efficacy of stimulant treatment ADHD/TBI. METHOD: A systematic review of the literature using a quality assessment scale to assess the quality of randomized clinical trials was undertaken. We identified all studies in which stimulants had been administered to individuals with ADHD/TBI. Information was extracted on study characteristics, interventions, and outcomes. A meta-analysis was not performed because of the limited number of studies with strict research design and the heterogeneity of outcome measures. Seven studies involving 118 subjects, 41 of whom were children and adolescents, were identified. RESULTS: Of the seven identified studies, one was a chart review, one used a single-blind, placebo-controlled crossover design, and five were double-blind, placebo-controlled crossovers. These studies used >50 subjective and objective tests to measure behavioral and cognitive outcomes. Methylphenidate (MPH) effects on behavior (hyperactivity, impulsivity) were evident but were not as robust as those typically observed with MPH in primary ADHD. The effect of MPH on cognition was less apparent. More favorable outcome was associated with initiation of treatment soon after head injury, although this factor was not systematically studied, and trials with relatively long durations. Studies with negative MPH response reported neither improvement in behavioral nor cognitive symptoms. CONCLUSION: There is only modest evidence to support the efficacy of MPH in the treatment of ADHD/TBI. While MPH might still be a promising treatment for ADHD/TBI, there is need for rigorous treatment outcome research among representative samples of ADHD/TBI individuals.

Adolescent↗
PubMed1998

A nonparametric bootstrap method for testing close linkage vs. pleiotropy of coincident quantitative trait loci.

A novel method using the nonparametric bootstrap is proposed for testing whether a quantitative trait locus (QTL) at one chromosomal position could explain effects on two separate traits. If the single-QTL hypothesis is accepted, pleiotropy could explain the effect on two traits. If it is rejected, then the effects on two traits are due to linked QTLs. The method can be used in conjunction with several QTL mapping methods as long as they provide a straightforward estimate of the number of QTLs detectable from the data set. A selection step was introduced in the bootstrap procedure to reduce the conservativeness of the test of close linkage vs. pleiotropy, so that the erroneous rejection of the null hypothesis of pleiotropy only happens at a frequency equal to the nominal type I error risk specified by the user. The approach was assessed using computer simulations and proved to be relatively unbiased and robust over the range of genetic situations tested. An example of its application on a real data set from a saline stress experiment performed on a recombinant population of wheat (Triticum aestivum L. ) doubled haploid lines is also provided.

Computer Simulation↗
PubMed2001

Advanced integrated mouse YAC map including BAC framework.

Functional characterization of the mouse genome requires the availability of a comprehensive physical map to obtain molecular access to chromosomal regions of interest. Positional cloning remains a crucial way of linking phenotype with particular genes. A key step and frequent stumbling block in positional cloning is making a contig of a genetically defined candidate region. The most efficient first step is isolating YAC (Yeast Artificial Chromosome) clones. A robust, detailed YAC contig map is thus an important tool. Employing Interspersed Repetitive Sequence (IRS)-PCR genomics, we have generated an advanced second-generation YAC contig map of the mouse genome that doubles both the depth of clones and the density of markers available. In addition to the primarily YAC-based map, we located 1942 BAC (Bacterial Artificial Chromosome) clones. This allows us to present for the first time a dense framework of BACs spanning the genome of the mouse, which, for instance, can serve as a nucleus for genomic sequencing. Four large-insert mouse YAC libraries from three different strains are included in our data, and our analysis incorporates the data of Hunter et al. and Nusbaum et al. There is a total of 20,205 markers on the final map, 12,033 from our own data, and a total of 56,093 YACs, of which 44,401 are positive for more than one marker.

Algorithms↗
PubMed2003

Gene silencing in Caenorhabditis elegans by transitive RNA interference.

When a cell is exposed to double-stranded RNA (dsRNA), mRNA from the homologous gene is selectively degraded by a process called RNA interference (RNAi). Here, we provide evidence that dsRNA is amplified in Caenorhabditis elegans to ensure a robust RNAi response. Our data suggest a model in which mRNA targeted by RNAi functions as a template for 5' to 3' synthesis of new dsRNA (termed transitive RNAi). Strikingly, the effect is nonautonomous: dsRNA targeted to a gene expressed in one cell type can lead to transitive RNAi-mediated silencing of a second gene expressed in a distinct cell type. These data suggest dsRNA synthesized in vivo can mediate systemic RNAi.

Animals↗
PubMedDate not supplied

Transforming a conservative company--one laugh at a time.

You wouldn't think of Brady Corporation as an obvious place in which to find a fun culture. This traditional Midwestern company, a manufacturer of industrial signs and other identification products, didn't even allow employees to have coffee at their desks until 1989. But when Katherine Hudson became CEO in 1994, she and her executive team determined that injecting some fun into the company's serious culture could create positive effects within the organization and contribute to increased performance and sales. In this article, Hudson distills her approach to overhauling Brady's culture into six principles of serious fun: More people than you might think are comfortable having fun at work; used with an awareness of cultural sensitivities, fun and laughter really are well-understood international languages; humor can help companies get through tough times; fun can be embodied in formal programs; spontaneous efforts at humor can also be effective; and encouraging fun should begin at the top. She richly illustrates each principle with examples. At Brady, getting people to loosen up and enjoy themselves has fostered a company esprit de corps and greater team camaraderie. It has started conversations that have sparked innovation, helped to memorably convey corporate messages to employees, and increased productivity by reducing stress, among other benefits. And the company has doubled its sales and almost tripled its net income and market capitalization over the past seven years. Brady's experience suggests that promoting fun within the workplace can lead not only to a robust corporate culture but also to improved business performance.

Commerce↗
PubMed2001

Renal ischemia-induced Fos expression in catecholaminergic neurons of rats.

The present study was undertaken to define whether the renal artery occlusion (RAO) would activate the catecholaminergic neurons in the brainstem nuclei by double immunohistochemical method for detecting Fos and tyrosine hydroxylase. The results are as follows: (1) while the basal expression of Fos was relatively low in the brainstem, RAO was capable of inducing a robust Fos-like immunoreactive neurons in the nucleus tractus solitarius (NTS), area postrema (AP), nucleus paragigantocellularis lateralis (PGL) and locus coeruleus (LC); (2) numerous catecholaminergic neurons in NTS, AP, PGL and LC could be activated by RAO as shown by Fos expression; and (3) these responses to RAO were significantly attenuated by pretreatment with an adenosine receptor antagonist 8-phenyltheophylline. The results suggest that RAO can activate a large number of neurons including some catecholaminergic neurons in the brainstem nuclei. Such effects of renal ischemia may be attributed to RAO-induced adenosine release from the kidney which subsequently activates renal afferents.

Animals↗
PubMed1998

Population pharmacokinetic-pharmacodynamic modeling of moxonidine using 24-hour ambulatory blood pressure measurements.

OBJECTIVES: To develop a model for 24-hour ambulatory blood pressure measurements (ABPM) that can be applied in a pharmacokinetic-pharmacodynamic model. METHODS: Four different data sets were prepared from 2 studies to accommodate different modeling strategies. In study A, a double-blind placebo-controlled study in 47 patients, 24-hour ABPM profiles (74 to 99 measurements per profile) were obtained during the placebo run-in phase and after 3, 5, and 11 weeks during the treatment. Three to 5 plasma samples were taken. Cosine and polynomial models were evaluated to describe the circadian rhythm in blood pressure based on 3 data sets (1: only run-in data; 2: only placebo data; 3: all data). In study B, a double-blind placebo-controlled study in 94 patients, two 24-hour ABPM profiles per patient (during placebo run-in and after 8 weeks) were recorded and randomly reduced to 15 measurements per profile to evaluate the robustness of the baseline model. RESULTS: The mean moxonidine clearance was 35 L/h, and the volume of distribution was 132 L. The final baseline model consisted of 2 cosine terms with fixed-effect parameters for rhythm-adjusted 24-hour mean blood pressure, amplitude, phase, and period; random-effect parameters for interindividual variability in rhythm-adjusted 24-hour mean, amplitude, and clock time; and interoccasion variability in rhythm-adjusted 24-hour mean and clock time. The final baseline model was combined with an Emax model for the drug effect. An effect compartment was used (kco = 0.198 h-1). The maximum decrease in diastolic blood pressure (Emax) was 16.7%, and EC50 was 0.945 microgram/L. CONCLUSION: The pharmacokinetic-pharmacodynamic model for 24-hour ABPM can be used to estimate the concentration-effect relationship of antihypertensive drugs.

Aged↗