In-vivo/in-vitro correlation of four extended release formulations of pseudoephedrine sulfate

An in-vivo/in-vitro correlation was established for four formulations of pseudoephedrine sulfate modified release tablets exhibiting different in-vivo and in-vitro release rate and absorption characteristics. In-vitro release rate data were obtained for 12 individual tablets of each formulation using the USP Apparatus 2 paddle stirrer at 50 rev min-1 in 1000 ml 0.1 N hydrochloric acid for the first hour followed by 0.1 M phosphate buffer at pH 7.5 for hours 2-16. Inspection of the individual and mean release rate data indicated that the in-vitro release rate of pseudoephedrine sulfate was consistent with the intended design of the four extended release formulations. The in-vivo bioavailability and pharmacokinetics of these formulations were evaluated in 20 healthy volunteers under fasted conditions. Wagner-Nelson analyses of the in-vivo data revealed extended release absorption profiles for all four formulations. Linear regression analyses of the mean percentage of dose absorbed versus the mean in-vitro release resulted in statistically significant correlations (r2 > 0.99, p < 0.0001) for each formulation. Qualitative rank order correlations were observed among all combinations of in-vivo and in-vitro parameters. These data support a Level A correlation between in-vivo absorption profiles and in-vitro release rates of four pseudoephedrine sulfate extended release formulations determined in fasted healthy volunteers.

Drug discovery using receptors that modulate gene expression

Cytokines and non-peptidyl small molecules, such as steroid hormones, exert many of their effects on cells through rapid regulation of gene expression. This is achieved by the activation of different families of latent transcription factors, which bind to specific sequences in the promoters of regulated genes. High throughput assay systems have been developed based on a detailed molecular understanding of these transcriptional regulation processes, and are being used as screens for both agonists and antagonists of specific cytokines and hormones. The opportunities for the discovery of novel and selective compounds using these systems is discussed.

An open pilot study of citalopram for behavioral disturbances of dementia. Plasma levels and real-time observations

Citalopram, in European studies, has shown some early promise for treatment of poststroke depression and behavioral complications of dementia. An open pilot study of citalopram was conducted in 16 patients with dementia and behavioral disturbances. Citalopram was well tolerated by 13 of the patients, and 9 had a clinically impressive response. A significant overall mean reduction in disruptive vocalizations was observed by means of a novel technique of computer-assisted real-time observation. The mean citalopram plasma level-to-dose ratio was found to be twice that previously reported in younger patients. These pilot findings should encourage future placebo concentration-controlled trials.

Multiple signaling pathways induced by granulocyte colony-stimulating factor involving activation of JAKs, STAT5, and/or STAT3 are required for regulation of three distinct classes of immediate early genes

Granulocyte colony-stimulating factor (G-CSF) is the major regulator of proliferation and differentiation of neutrophilic granulocyte precursor cells. G-CSF activates multiple signaling molecules, including the JAK1 and JAK2 kinases and the STAT transcription factors. To investigate G-CSF signaling events regulated by the JAK-STAT pathway, we have generated UT7-epo cells stably expressing either wild-type (wt) G-CSF receptor or a series of C-terminal deletion mutants. Gel mobility shift and immunoprecipitation/Western analysis showed that STAT5 is rapidly activated by G-CSF in cells expressing the wt G-CSF receptor, in addition to the previously reported STAT3 and STAT1. Mutants lacking any tyrosine residues in the cytoplasmic domain maintain their ability to activate STAT5 and STAT1 but cannot activate STAT3, implying that STAT5 and STAT1 activation does not require receptor tyrosine phosphorylation. We also observed significant changes in the ratio of STAT1:STAT3:STAT5 activated by various G-CSF receptor C-terminal deletion mutants. These mutant receptors were further used to investigate the role of JAKs and STATs in G-CSF-mediated responses in these cells. We found that JAK activation correlates with G-CSF-induced cell proliferation, whereas STAT activation is not required. We have also identified three classes of G-CSF immediate early genes, whose activation correlates with the activation of distinct JAK-STAT pathways. Our data show that, whereas c-fos is regulated through a pathway independent of STAT activation, oncostatin M, IRF-1, and egr-1 are regulated by an STAT5-dependent pathway and fibrinogen is regulated by an STAT3-dependent pathway. In conclusion, our results suggest that G-CSF regulates its complex biologic activities by selectively activating distinct early response genes through different JAK-STAT signaling molecules.

Association of the APOE epsilon 4 allele with clinical subtypes of late life depression

The APOE genotypes of 45 elderly inpatients with major depression were determined to investigate the relationship of this disorder to irreversible dementia in late life. We specifically tested the hypothesis that the frequency of the APOE epsilon 4 allele is elevated in depressed elders with cognitive impairment or psychotic features, subtypes that have been reported to be at increased risk of developing Alzheimer's disease (AD). The frequency of epsilon 4 allele was not elevated in the overall group of 45 inpatients and, contrary to our expectation, was not associated with cognitive impairment in this group. In contrast, the epsilon 4 allele frequency for the patients with psychotic features was nearly four times that for the patients without psychotic features and nearly double that of elderly controls. These data suggest that elderly depressed inpatients with cognitive impairment are at risk for developing AD by an epsilon 4-independent pathway, while those with psychotic features are at risk for developing AD by an epsilon 4-dependent pathway. These findings suggest that subtypes of idiopathic major depression in late life may serve as landmarks that distinguish separable pathogenetic pathways to AD.

Reconstruction of longitudinal distributed incoherent sources

We describe measurement of the degree of coherence induced by a random light source distributed along the longitudinal z axis. If this degree of coherence is measured only between all the in-plane pairs of points placed along the radial lines it is proportional to the Fourier transform of the source's three-dimensional intensity distribution as seen from the paraxial far zone. A reconstruction of the source shape from the measured degree of coherence is also demonstrated.

Determinants of promoter-specific activity by glucocorticoid receptor

Glucocorticoid receptor (GR) is expressed at essentially equal levels in almost all tissues and cell types. Remarkably, glucocorticoids themselves regulate transcription in vivo in both a promoter- and tissue-specific manner. Thus, specific systems must be in place to regulate receptor action within certain cells and at certain promoters. To address two specific aspects of these systems, we have analyzed promoter-specific activity of GR using two different, well studied promoters (termed simple and composite promoters) from which GR activates transcription. The simple promoter depends only on the receptor for glucocorticoid-responsive transcriptional activation, while GR activity at the composite promoter depends on additional transcription factors. We have compared the action of several GR ligands at these promoters and demonstrate fundamental differences in the activities of these ligands on receptor activity. Furthermore, these compounds induce unique conformational changes in receptor, resulting in promoter-specific receptor function. We have identified critical amino acid residues within GR which, when mutated, genetically distinguish the action of GR at these promoters. Taken together, the data indicate that the presence of only the receptor and the ligand is not sufficient to allow activation of transcription. An additional system of regulation influences receptor action in both a tissue- and promoter-selective fashion, suggesting that multiple, regulated surfaces of the receptor respond to the cellular environment and determine the spectrum of GR activities. These functional surfaces may be induced or regulated by ligand binding, by the DNA sequence to which receptor is bound, or by the nonreceptor factors resident at the promoter or in the tissue.

Three-dimensional imaging of random radiation sources

A method to image random three-dimensional source distributions is proposed. We show that, by using a Michelson stellar interferometer in a prescribed fashion, one is able to measure a special form of a threedimensional degree of coherence. The inverse Fourier transform of this coherence function yields the threedimensional intensity distribution of the source as seen from the paraxial far zone.

Snake beam: a paraxial arbitrary focal line

The creation of paraxial arbitrary focal lines by a Fourier computer-generated hologram is demonstrated. The desired focal line is represented by a series of connected straight line segments, each of which is implemented by a radial harmonic function located on a different radial portion of the entire hologram. Each subhologram is multiplied by appropriate linear and quadratic phase functions and is shifted by some distance from the center. The two phase factors determine the location of each line segment, while the in-plane shift determines the tilt angle of the segment.

STAT protein complexes activated by interferon-gamma and gp130 signaling molecules differ in their sequence preferences and transcriptional induction properties

Activation of members of the STAT (signal transducers and activators of transcription) family of latent transcription factors is an early event following the binding of many cytokines to their cognate receptors. Although the patterns of STATs activated by different cytokines are well described, the consequences of differential STAT activation are less well studied. We show by mutational analysis that STAT binding elements (SBEs) exist that discriminate between STAT complexes containing STAT1 alpha, STAT3 or both, and that these elements show altered cytokine responsiveness. We also show that in the context of a minimal promoter, single and multiple SBEs exhibit strikingly different patterns of transcriptional activation in response to IFN-gamma, IL-6, OSM or LIF. These differences in transcriptional activation are correlated with the differential ability of these cytokines to activate STAT1 alpha, STAT3 or both. Our results show that the pattern of STATs activated by a cytokine and the arrangement and sequence of the SBEs in the responding promoter have a profound effect on the ability of the cytokine to elicit a transcriptional response.

Application of serial- and parallel-projection methods to correlation-filter design

We describe generalized projection procedures for the design of arbitrary filter functions for correlators. More specifically, serial and parallel implementations of projection-based algorithms are employed. The novelty of this procedure lies in its generality and its ability to handle wide varieties of constraints by the same procedure. The procedure is demonstrated by the design of filters for the 4-ƒ linear correlator, the phase-extraction correlator, and variants thereof. The filters are subject to a variety of constraints, including rotation-invariant pattern recognition and class discrimination. Examples are given to show the versatility, flexibility, and applicability of the design process to a variety of pattern-recognition tasks. Satisfactory results are also obtained because of the combination with the special nonlinear correlators proposed for pattern recognition.

Clinical profile, comorbidity, and treatment history in 123 hair pullers: a survey study

BACKGROUND

Trichotillomania, characterized by an irresistible urge to pull one's hair, may be more prevalent than previously believed. Despite increasing attention devoted to this topic in the recent literature, there are few studies based on large samples that are potentially generalizable to a community population.

METHOD

Surveys addressing clinical profile, comorbidity, and treatment history were mailed to all responders to a nationally distributed magazine article on trichotillomania. Out of 772 surveys sent, 123 completed surveys were returned.

RESULTS

While there was a predominance of females in the whole sample, female-to-male prevalence was lower in children than adults. Onset was predominantly in childhood (mean age = 11 years), most frequently in middle childhood and least frequently before age 6. Subjects pulled hair from a variety of sites, including scalp, eyelashes, eyebrows, pubic region, face, and body, but the highest incidence and severity involved scalp hair. Children under 6 were more likely than other age groups to pull scalp hair and possibly less likely to pull other hair. In adults, symptom profile was not associated with age at onset. While subjects reported high rates of comorbid conditions in both self and family, trichotillomania was reportedly formally diagnosed in only 40% of the subjects. Although subjects reported a range of treatments, the majority (58%) reported no treatment history. Finally, only minimal improvement was reported for all modalities, with no significant difference in response to psychotherapy, behavior therapy, clomipramine, or fluoxetine.

CONCLUSION

Trichotillomania is a chronic illness that may be difficult to treat. Controlled studies on comorbidity, epidemiology, treatment-seeking patterns, and long-term treatment response are needed.

Retardation and reduction of pulse distortion by group-velocity dispersion through pulse shaping

We show that a reduction in the pulse distortion caused by chromatic dispersion can be achieved through pulse shaping. We argue that a simple binary phase mask in the Fourier plane of the laser spectrum can improve the transmission of short pulses in a dispersive channel through reduced broadening. The argument was tested experimentally, and a good agreement was found with the theory.

Spacing of palindromic half sites as a determinant of selective STAT (signal transducers and activators of transcription) DNA binding and transcriptional activity

Signal transducers and activators of transcription (STAT proteins) bind to palindromic sequence elements related to interferon gamma (IFN-gamma) activation sites, which were first identified in the promoters of IFN-gamma-inducible genes. Although the sequences of the natural palindromic STAT-binding elements vary considerably, they conform to the general structure TT(N)5AA. We have systematically examined the effects of the spacing between the TT and AA core half sites on the binding of the STAT complexes activated by IFN-gamma, interleukin (IL) 6, granulocyte-macrophage colony-stimulating factor, and IL-4. We show that (i) as suggested earlier, a core palindromic TT--AA motif with a 5-bp spacing displays general STAT binding, (ii) a palindromic motif with a spacing of 4 bp selectively binds to complexes containing Stat3, and (iii) a motif with a 6-bp spacing selectively binds the STAT complexes activated by IL-4. We have examined natural elements in the promoters of cytokine-responsive genes that differ in half-site spacing and found that they display binding properties predicted from the synthetic binding sites. Furthermore, the observed differential selective binding characteristics for the most part correlate with the ability to mediate transcriptional activation of transfected test genes in response to the cytokines tested. Our results thus demonstrate that the specificity of STAT-directed transcription in response to particular cytokines or cytokine families depends in part on the spacing of half sites within the conserved response element sequence.

Pseudonondiffracting slitlike beam and its analogy to the pseudonondispersing pulse

A new nonspreading beam is proposed for the case in which diffraction occurs only in one transverse coordinate. The beam has the shape of a pulse in one dimension and is constant in the other (slitlike shape). The intensity of the pulse's peak remains almost constant along a finite interval on the propagation axis. The proposed beam is analyzed and demonstrated experimentally. The analogy between this beam and the temporal pulse in a dispersive medium is discussed.

Prospective cytochrome P450 phenotyping for neuroleptic treatment in dementia

Older patients have more adverse experiences when treated with psychotropics than younger patients. Age-associated physiological changes, such as reductions in hepatic mass and blood flow, magnify genetic and acquired variations in drug metabolism. Cytochrome P450 2D6 (debrisoquine hydroxylase), which is responsible for the metabolism of several antidepressants and neuroleptics, is constitutionally deficient in up to 10 percent of the population. In this study of 45 elderly patients suffering from dementia and treated with perphenazine, 5 patients who were prospectively identified as poor P450 2D6 metabolizers had significantly greater side effects than the 40 extensive metabolizers.