bluuebunny/crossref_metadata_2025 huggingface dataset:
ANTICORRELATIONS AND SUBDIFFUSION IN FINANCIAL SYSTEMS
Authors: STALIUNAS K.
Published: August 2003

Statistical dynamics of financial systems is investigated, based on a model of a randomly coupled equation system driven by a stochastic Langevin force. It is found that in a stable regime the noise power spectrum of the system is 1/f-like: ∝ ω- 3/2 (where ω is the frequency), that the autocorrelation function of the increments of the variables (returns of prices) is negative and follows the power law: ∝ - τ- 3/2 (where τ is the delay), and that the stochastic drift of the variables (prices, exchange rates) is subdiffusive: ∝ tH (where t is the time, H ≈ 1/4 is the Hurst, or self-similarity, exponent). These dependencies correspond to those calculated from historical $/EURO exchange rates.
FUNCTIONAL APPROXIMATION IN MULTISCALE COMPLEX SYSTEMS
Authors: CAPOBIANCO ENRICO
Published: August 2003

One common approach for exploring, approximating and estimating complex system dynamics refers to models based on elementary or atomic building block components of easier interpretation and efficient computation. We adopt a combination of wavelets, greedy approximation and subspace techniques to investigate complex systems such as speculative financial markets. These systems are endowed with multiscale and non-stationary dynamics that we aim to artificially learn by using functional approximation and optimization theory. We show that volatility dynamics are embedded in a sequence of nested informative scales and thus a multiscale estimation approach is indicated to deal with them.
FRONT PROPAGATION IN UNIAXIAL FERROMAGNETS
Authors: FERMIN J. R. , RIVAS SUÁREZ R. , FRANCESCHINI J. P. , RODRÍGUEZ L. J.
Published: August 2003

This work is a theoretical study of fronts propagating into an uniaxial ferromagnetic medium with velocity v, when the magnetization, M, is driven by a DC applied magnetic field, H0, from the demagnetized to the magnetized state. It is assumed that the dynamics of M is govern by the Landau–Lifshitz–Gilbert equation (LLGE). We also consider an effective field that includes in-plane uniaxial, HU, and shape anisotropy fields, HD. We show that, in the particular case of uniformly translating profiles, this equation reduces to a damped-forced Duffing's equation, with a family of solutions that describe periodic oscillating (PO), damped oscillating (DO) or exponential front profiles (EF). Of particular interest is the existence of a critical speed, v0, below which there are no stable states for the magnetization. When the velocity of the profile exactly equals v osc , the only stable states are the PO profiles. Above v osc , there is an asymptotic speed, v*, that separates the DO profiles from EF profiles. This velocity (v*) is connected with the existence of a non-linear marginal stability point for front propagation. Both v0 and v* depend on the applied field and on the anisotropy constants of the material. A stability diagram for front propagation and magnetization curves are also calculated.
FRACTAL DIMENSION, PRIMES, AND THE PERSISTENCE OF MEMORY
Authors: PE JOSEPH L.
Published: August 2003

Many sequences from number theory, such as the primes, are defined by recursive procedures, often leading to complex local behavior, but also to graphical similarity on different scales — a property that can be analyzed by fractal dimension. This paper computes sample fractal dimensions from the graphs of some number-theoretic functions. It argues for the usefulness of empirical fractal dimension as a distinguishing characteristic of the graph. Also, it notes a remarkable similarity between two apparently unrelated sequences: the persistence of a number, and the memory of a prime. This similarity is quantified using fractal dimension.
Influence of Cycloversions Induced by Head Tilt on Scanning Laser Polarimetry Parameters
Authors: Jehn Andrea B. , Muri René M. , Mojon Daniel S.
Published: August 2003

Objective: To study the influence of cycloversions induced by head tilt on parameters of scanning laser polarimetry. Methods: Five left and five right eyes of 9 normal subjects were measured in seven different head tilt positions by one examiner using a scanning laser polarimeter (Nerve Fiber Analyzer, NFA II, LDT Inc., San Diego, Calif., USA). Images were acquired for the following head tilt positions: upright, 10, 20, 30° to the right, and 10, 20, 30° to the left. For each position five to eight images of the peripapillary area were recorded. Objective cycloversions were determined trigonometrically on the fundus pictures provided by the scanning laser ophthalmoscope. Parameters acquired for different head positions were compared using a Friedmann’s two-way analysis of variance. Results: Average objective cyclodeviations were 5.9° for the 10° head tilts, 11.2° for the 20° head tilts, and 18.9° for the 30° head tilts. Head tilts to the right in left eyes and to the left in right eyes (both of them corresponding to an incycloposition) induced a significant increase in several parameters (p < 0.05). Head tilts to the left in left eyes and to the right in right eyes (both corresponding to an excycloposition) showed no influence on parameters (p > 0.05). Conclusions: Ocular incycloposition has a significant influence on several scanning laser polarimetry parameters. Therefore, evaluation is limited in patients having an incyclorotation of the nonfixating eye with the head in an upright position or in patients having a head tilt inducing an incyclorotation.
Automated Analysis of Eye Tracking Movements
Authors: Ruetsche Adrian , Baumann Ann , Jiang Xiaoyi , Mojon Daniel S.
Published: August 2003

Objective: To present a quick algorithm to automatically analyze the raw data acquired by a photo-oculography (POG) system. Methods: We developed a simple algorithm for POG data analysis based on an extrapolation of missing values due to blinking and on exclusion of outliers using the robust mean and standard deviation. Results: POG curves of 4 children aged between 1.5 and 7 years are shown before and after automatic analysis. After applying our algorithm, the curves are much smoother. Conclusion: Our algorithm allows a quick data analysis and will help to better interpret and analyze POG data.
Tumour Regression of Uveal Melanoma after Ruthenium-106 Brachytherapy or Stereotactic Radiotherapy with Gamma Knife or Linear Accelerator
Authors: Georgopoulos Michael , Zehetmayer Martin , Ruhswurm Irene , Toma-Bstaendig Sabine , Ségur-Eltz Nikolaus , Sacu Stefan , Menapace Rupert
Published: August 2003

Purpose: This study assesses differences in relative tumour regression and internal acoustic reflectivity after 3 methods of radiotherapy for uveal melanoma: (1) brachytherapy with ruthenium-106 radioactive plaques (RU), (2) fractionated high-dose gamma knife stereotactic irradiation in 2–3 fractions (GK) or (3) fractionated linear-accelerator-based stereotactic teletherapy in 5 fractions (Linac). Methods: Ultrasound measurements of tumour thickness and internal reflectivity were performed with standardised A scan pre-operatively and 3, 6, 9, 12, 18, 24 and 36 months postoperatively. Of 211 patients included in the study, 111 had a complete 3-year follow-up (RU: 41, GK: 37, Linac: 33). Differences in tumour thickness and internal reflectivity were assessed with analysis of variance, and post hoc multiple comparisons were calculated with Tukey’s honestly significant difference test. Results: Local tumour control was excellent with all 3 methods (>93%). At 36 months, relative tumour height reduction was 69, 50 and 30% after RU, GK and Linac, respectively. In all 3 treatment groups, internal reflectivity increased from about 30% initially to 60–70% 3 years after treatment. Conclusion: Brachytherapy with ruthenium-106 plaques results in a faster tumour regression as compared to teletherapy with gamma knife or Linac. Internal reflectivity increases comparably in all 3 groups. Besides tumour growth arrest, increasing internal reflectivity is considered as an important factor indicating successful treatment.
Phacoemulsification and Intraocular Lens Implantation for Angle Closure Glaucoma after the Relief of Pupillary Block
Authors: Kubota Toshiaki , Toguri Ichiro , Onizuka Naoko , Matsuura Toshie
Published: August 2003

Purpose: We studied the surgical outcomes of phacoemulsification and intraocular lens (IOL) implantation for cataract and/or uncontrolled intraocular pressure (IOP) in eyes with angle closure glaucoma. Setting: Department of Ophthalmology, National Nagasaki Medical Center, Nagasaki, Japan. Methods: Eighteen eyes from 15 patients after laser iridotomy (17 eyes) or peripheral iridectomy (1 eye) had undergone surgery and were studied. We used an iris retractor in 7 eyes due to insufficient mydriasis and a capsular tension ring in 2 eyes due to phacodonesis during the operation. The patients were followed up for at least 6 months (13.8 ± 7.2 months; range: 6–36 months). Results: The mean IOP significantly decreased from 17.4 ± 8.1 to 13.5 ± 3.3 mm Hg at 6 months after surgery. The IOP was below 21 mm Hg in all eyes. The visual acuity was not worsened in any eyes and became better than 2 Snellen lines in 14 eyes. The corneal endothelial cell count decreased from 2,365 ± 517 to 1,960 ± 661/mm2 (18.3 ± 17.2%). Conclusions: Phacoemulsification and IOL implantation is useful in IOP control for angle closure glaucoma after relief of pupillary block. However, we should take care of operative complications because of a shallow anterior chamber, poor mydriasis and zonular weakness.
Effects of Extended-Wear Soft Contact Lenses on the Ocular Surface and Central Corneal Thickness
Authors: Gürdal Canan , Aydin Sevda , Kirimlioğlu Hale , Toprak Ebru , Şengör Tomris
Published: August 2003

Purpose: New contact lens materials with high oxygen permeability are said to be convenient for the extended-wear (EW) schedule. We evaluated the short-term effect of EW soft contact lens usage on ocular surface and central corneal thickness. Patients and Methods: Fifty-two eyes of 26 patients were included in the study. Sixteen of the patients used the high oxygen-permeable lenses for a 30-day extended-wear schedule (group I). Ten patients used the lenses on a daily wear basis (DW, group II). All patients were evaluated for visual acuity and central corneal thickness by corneal and conjunctival biomicroscopy, Schirmer and tear break-up time (BUT) tests. Impression cytology was performed in the superior/temporal, inferior/nasal quadrants of the conjunctiva, 1 mm from the limbus, with cellulose acetate filter paper. The specimens were graded under light microscopy according to Nelson’s classification. Results: Three patients in the EW group were excluded from the study as they discontinued lens usage due to slight discomfort and hyperemia. Biomicroscopic findings and tear function tests indicated no increased pathological results. Central corneal thickness decreased from 554 ± 9.55 to 546 ± 9.30 µm (mean ± SEM) in the EW group (p = 0.002), whereas no significant change occurred in the DW group. Cytological evaluation of the EW group showed an 88% increase in metaplasia (p = 0.007), especially close to the limbal areas and in the superior quadrants; this ratio was 30% in the DW group. Snake-like chromatin changes were found to be increased, from 4 to 6 patients, in the EW group while it remained the same in the DW group (p > 0.05). Individual comparisons of the initial and final pathological conditions of the ocular surfaces in the two groups showed that there was an increase in pathology in the EW group while there was no significant difference in the DW group. Conclusions: On a 30-day extended-wear basis with high oxygen-permeable lenses, the possible development and increase of conjunctival cytologic changes secondary to mechanical trauma is one of the main remaining problems. Conjunctival and related immunologic pathologies should not be overlooked when prescribing an extended-wear lens schedule.
Protective Effects of Pentoxifylline in Retinal Ischemia/Reperfusion Injury
Authors: Demir Tamer , Ulas Fatih , Ozercan Ibrahim , Ilhan Nevin , Celiker Ulku , Yasar M. Akif
Published: August 2003

We studied the effect of pentoxifylline on retinal lipid peroxidation and histopathologic changes due to ischemia/reperfusion (I/R). A total of 15 pigmented male guinea pigs were divided into 3 equal groups as control, sham and treatment groups. After application of high intraocular pressure for 90 min for the induction of retinal ischemia, 24-hour reperfusion was established in the sham and treatment groups. In the treatment and sham groups, either 45 mg/kg of pentoxifylline or saline was given 3 times at 8-hour intervals. Biochemical assay and histopathologic evaluation were performed on one randomly selected eye of each animal which was enucleated at the end of the reperfusion period, and retinal malondialdehyde (MDA) levels and thickness of the retinal tissue were determined for each group. The mean MDA level of the sham group was significantly higher versus the control and treatment groups (p < 0.001). When compared with the control group, the mean MDA level of the treatment group was slightly higher, but the difference was not statistically significant (p > 0.05). In comparison with the control group there was a significant increase in the thickness of the retina in the sham group (p < 0.0001), and no significant difference was found in the retinal thickness of the treatment group (p > 0.05). Pentoxifylline might have a preventive effect on the I/R injury of the retina.
Possible Involvement of Nitric Oxide in the Progression of Diabetic Retinopathy
Authors: Tsai Der-Chong , Chiou Shih-Hwa , Lee Fenq-Lih , Chou Ching-Kuang , Chen Shih-Jen , Peng Chi-Hsien , Kuo Yao-Haur , Chen Chieh-Fu , Ho Larry L.-T. , Hsu Wen-Ming
Published: August 2003

Abnormal nitric oxide (NO) synthesis has been implicated in the pathogenesis of diabetes mellitus. The aim of our study was to elucidate the relationship between the stages of diabetic retinopathy (DR) and the NO levels in aqueous humor and plasma. Using the chemiluminescence assay, we measured the concentrations of NO in aqueous humor and plasma samples obtained during intraocular surgery from 45 diabetic patients and 19 nondiabetic cataract patients. The patients with diabetes were classified into 4 groups: proliferative DR (PDR) with active neovascularization (active PDR; 9 cases), PDR with quiescent neovascularization (regressed PDR; 6 cases), background DR (BDR; 16 cases) and no DR (14 cases). We found that the aqueous NO levels (mean ± SE) of the active PDR group (83.2 ± 13.9 µM) were significantly higher than those of the BDR group (45.8 ± 6.0 µM, p = 0.049) and the diabetics without DR (33.3 ± 5.2 µM, p = 0.011), and, although not statistically significantly, they were also higher than those of the regressed PDR group (52.1 ± 10.3 µM, p = 0.224). However, no significant differences were observed between any of the diabetic subgroups in the plasma NO levels (p = 0.345). We therefore concluded that NO present in the ocular tissues may play important roles in the progression of DR.
The Effect of Blood Glucose Regulation on Retinal Nerve Fiber Layer Thickness in Diabetic Patients
Authors: Lonneville Yıldız H. , Özdek Şengül C. , Önol Merih , Yetkin İlhan , Gürelik Gökhan , Hasanreisoğlu Berati
Published: August 2003

Purpose: To evaluate the effect of blood glucose (BG) regulation on the retinal nerve fiber layer (RNFL) in diabetic patients by using a scanning laser polarimeter (NFA-GDx). Methods: We prospectively assessed RNFL thickness in diabetic patients and an age-matched control group. Patients without diabetic retinopathy, with BG >250 mg/dl, HbA1c >8%, fructosamine >285 µmol/l and triglyceride >200 mg/dl were included in the study. RNFL assessment was performed before and after metabolic regulation of diabetes. Symmetry, superior maximum, ellipse modulation and the average thickness variables of NFA-GDx were used for the assessment. Mann-Whitney U and Wilcoxon tests were used for the statistical analysis. Results: A total of 40 diabetic patients were included in the study and a repeat RNFL examination could be performed in 22 of them following regulation of BG levels. None of the GDx variables were significantly different between pre- and postregulation measurements (p > 0.05, Wilcoxon test). The mean superior maximum, ellipse modulation and average thickness values of the diabetic group were significantly lower than the control group (p < 0.05, Mann-Whitney U-test). Conclusions: Poor metabolic control of diabetes mellitus adversely affects the thickness of RNFL and this effect does not seem to be acute since it was not reversed by short-term BG regulation. This issue needs to be kept in mind when assessing glaucomatous progress in diabetic patients.
Mitotropic Compounds for the Treatment of Age-Related Macular Degeneration
Authors: Feher J. , Papale A. , Mannino G. , Gualdi L. , Balacco Gabrieli C.
Published: August 2003

Recent histopathologic studies have shown that mitochondria and peroxisomes of the retinal pigment epithelium may play a central role in the pathophysiology of age-related macular degeneration (AMD). We supposed that compounds which improve mitochondrial functions (mitotropic compounds) may show beneficial effects in preventing AMD. Fourteen patients affected by early AMD were treated with a mixture containing acetyl-L-carnitine (ALC), polyunsaturated fatty acids (PUFAs), coenzyme Q10 (CoQ10) and vitamin E, while an equal number of age- and sex-matched patients affected by early AMD were treated with vitamin E only. Recovery time after macular photostress, foveal sensitivity and mean defect in the visual field as well as blood lipid levels were recorded at the beginning and after 3, 6, 9, 12 and 24 months of follow-up. In the treated group, all the visual functions showed slight improvement which was evident after 3 months of treatment and remained nearly stationary by the end of 24 months. The same tests in the control group showed slow worsening. The divergence between treated and control groups became more marked with time, but the difference was not significant at any time of the follow-up. These findings suggest that the blend of ALC, PUFA, CoQ10 and vitamin E may improve retinal functions in early AMD.
Association of Interleukin 1β and Receptor Antagonist Gene Polymorphisms with Primary Open-Angle Glaucoma
Authors: Lin Hui-Ju , Tsai San-Chang , Tsai Fuu-Jen , Chen Wen-Chi , Tsai Jeffery J.P. , Hsu Cheng-Der
Published: August 2003

Purpose: Genetic factors are known to play a role in the etiology of glaucoma. More specifically, the role of the immune system is highly suspected. We evaluated the association between 2 polymorphisms in the interleukin (IL) 1β gene (IL-1 promoter 511, IL-1 exon 5) and 1 polymorphism in the IL-1 gene receptor antagonist (IL-1Ra) intron 2 with primary open-angle glaucoma (POAG). Patients and Methods: Fifty-eight POAG patients and 105 healthy volunteers were enrolled in this study. Analysis based on polymerase chain reaction was used to resolve the 2 IL-1β polymorphisms and the IL-1Ra intron 2 polymorphism. Results: There were significant differences in the distribution of the IL-1β exon 5 polymorphism between the POAG patients and the control subjects (p < 0.05). The E2 allele of IL-1β exon 5 was more frequently found in POAG patients than in healthy patients (odds ratio: 4.224, 95% confidence interval = 1.135–15.717). The distributions of the other 2 polymorphisms, IL-1β promoter 511 and IL-1Ra intron 2, were not significantly different between the POAG patients and the healthy control group. Conclusions: The frequency of the E2 allele of the IL-1β exon 5 polymorphism was high in POAG patients. Therefore the E2 allele can be used as a marker to predict or search for the genetic causes of glaucoma in Chinese POAG patients. Furthermore, we have concluded that the other 2 polymorphisms (IL-1 promoter 511 and IL-1Ra) are not helpful in predicting Chinese POAG.
Decreased Activation of the Lateral Geniculate Nucleus in a Patient with Anisometropic Amblyopia Demonstrated by Functional Magnetic Resonance Imaging
Authors: Miki Atsushi , Liu Grant T. , Goldsmith Zachariah G. , Liu Chia-Shang J. , Haselgrove John C.
Published: August 2003

Although postmortem morphological changes in the lateral geniculate nucleus (LGN) have been reported in human amblyopia, LGN function during monocular viewing by amblyopic eyes has not been documented in humans. We used functional magnetic resonance imaging (fMRI) to study monocular visual activation of the LGN in a patient with anisometropic amblyopia. Four normal subjects, a patient with optic neuritis and a patient with anisometropic amblyopia were studied with fMRI at 1.5 T during monocular checkerboard stimulation. Activated areas in the LGN and visual cortex were identified after data processing (motion correction and spatial normalization) with SPM99. In the 4 normal subjects, comparable activation of the LGN and visual cortex was obtained by stimulation of either the right or left eye. In the patient with unilateral optic neuritis, activation of the LGN and visual cortex was markedly decreased when the affected eye was stimulated. Similarly, decreased activation of the LGN as well as the visual cortex by the affected eye was demonstrated in the patient with anisometropic amblyopia. Our preliminary results suggest that activation of the LGN is diminished during monocular viewing by affected eyes in anisometropic amblyopia. fMRI appears to be a feasible method to study LGN activity in human amblyopia.
Pseudodoubling of the Optic Disc: A Colour Doppler Imaging Study
Authors: Cellini M. , Alessandrini A. , Bernabini B. , Merlo D.
Published: August 2003

Pseudodoubling of the optic disc is a rare clinical presentation. In these cases it is necessary to exclude retinal coloboma or atrophy following vascular or infectious diseases. We present a case of pseudodoubling of the optic disc in a woman with type 2 diabetes and arterial hypertension. Ophthalmoscopic examination of the fundus showed a disc-like lesion in the right eye and a diabetic retinopathy in the left eye. The lesion was evaluated with fluorescein angiography, neuroradiological and colour Doppler imaging investigations. Colour Doppler imaging confirmed the angiographic findings of anomalous vascularisation of the pseudopapilla and provides an analysis of the choroidal vessel anastomosis between the optic disc and the retinal lesion, revealing that the pseudodoubling in this patient was the result of a chorioretinal coloboma.
Reversion of ‘Early Worsening’ of Diabetic Retinopathy by Deliberate Restoration of Poor Metabolic Control
Authors: Chantelau E. , Meyer-Schwickerath R.
Published: August 2003

Acutely lowering long-standing severe hyperglycaemia can trigger progression (‘early worsening’) of diabetic retinopathy, most likely by up-regulation of the circulating insulin-like growth factor 1 (IGF-1). This condition, also called ‘florid retinopathy’, rarely responds to standard laser coagulation treatment. In this retrospective report, 2 young patients with type 2 diabetes are described, in whom deliberate restoration of poor diabetes control reduced the serum IGF-1 levels and improved ‘early worsened’ diabetic retinopathy.
Entry of Blood-Borne Cytokines into the Central Nervous System: Effects on Cognitive Processes
Authors: Banks William A. , Farr Susan A. , Morley John E.
Published: August 2003

Blood-borne cytokines affect many aspects of the central nervous system (CNS). One of the more dramatic effects is the induction of sickness behavior. Impairments in learning and memory are an important component of sickness behavior and are largely mediated by IL-1. Many mechanisms have been proposed by which a cytokine circulating in the blood can affect functions within the CNS. We review here the role one of those mechanisms, that of transport of cytokines across the blood-brain barrier (BBB), plays in induction of the memory impairments of sickness behavior. We have shown that the posterior division of the septum (PDS) plays a key role in mediating the effects of interleukin-1α (IL-1α) on memory. Furthermore, this effect at the PDS is largely mediated by circulating IL-1α acting directly at the PDS which, in turn, depends on the ability of IL-1α to cross the BBB.
Down-Regulation of Bcl-2, Activation of Caspases, and Involvement of Reactive Oxygen Species in 6-Hydroxydopamine-Induced Thymocyte Apoptosis
Authors: Tsao Chiung-Wen , Cheng Juei-Tang , Lin Yee-Shin
Published: August 2003

Objective: Our previous work showed that 6-hydroxydopamine (6-OHDA) induced mouse thymocytes to undergo apoptosis both in vivo and in vitro. In the present study, we further investigated the mechanisms of 6-OHDA-induced apoptosis in vitro. Methods: Naive mouse thymocytes were cultured with 6-OHDA. The percentages of apoptotic cells were quantified by propidium iodide staining, and DNA fragmentation was detected by agarose gel electrophoresis. Intracellular Bcl-2 was analyzed by immunofluorescence staining. Cu/Zn superoxide dismutase (Cu/Zn-SOD) activities were measured by the SOD-525 method. Results: The apoptotic effect of 6-OHDA was blocked by desipramine, a catecholamine uptake blocker. Treatment with 6-OHDA caused a reduction in Bcl-2 expression. VAD-FMK, a broad-spectrum caspase inhibitor, and DEVD-CHO, a potent inhibitor of caspase-3, could block 6-OHDA-induced thymocyte apoptosis. However, the specific caspase-1 (ICE) inhibitor YVAD-CMK had no effect. This cell death process was prevented by the protein synthesis inhibitor cycloheximide and by antioxidants. The level of Cu/Zn-SOD activities also decreased after cells were exposed to 6-OHDA. Conclusion: These results suggest an apoptotic effect of 6-OHDA via the uptake of this neurotoxin by thymocytes, and that down-regulation of Bcl-2, activation of caspases, such as caspase-3 but not caspase-1, generation of reactive oxygen species, and new synthesis of proteins are involved in this process.
Coemergence of Insomnia and a Shift in the Th1/Th2 Balance toward Th2 Dominance
Authors: Sakami Shotaro , Ishikawa Toshio , Kawakami Norito , Haratani Takashi , Fukui Akira , Kobayashi Fumio , Fujita Osamu , Araki Shunichi , Kawamura Noriyuki
Published: August 2003

Objectives: Insomnia is associated with physical and mental disorders. We examined the effect of insomnia on immune functions, focusing on the T helper 1 (Th1)/ T helper 2 (Th2) balance, by a cross-sectional design. Methods: We provided a self-administered questionnaire to evaluate sleep habits, smoking and medical disorders to 578 men without any toxic exposure (20–64 years old), and measured natural killer (NK) cell activity in 324 men and production of interferon-gamma (IFN-γ) and interleukin-4 (IL-4) after stimulation with phytohemagglutinin in 254 men. According to the criteria of DSM-IV, in which insomnia is classified into primary and secondary insomnia, we assessed the effect of insomnia on immune functions, controlling for age and smoking in groups with and without medical disorders. Results: The prevalence of insomnia in the present study was 9.2%. In the absence of medical disorders, insomniac men had a significantly lower IFN-γ and ratio of IFN-γ to IL-4 than noninsomniac men. Men with insufficient sleep or difficulty initiating sleep (DIS) had a significantly lower IFN-γ to IL-4 ratio than those not suffering from insufficient sleep or DIS. In the presence of medical disorders, insomniac men had significantly higher IL-4 than noninsomniac men. Men with difficulty maintaining sleep (DMS) had a significantly lower IFN-γ to IL-4 ratio than men without DMS. NK cell activity was independent of insomnia. Conclusions: The present results showed a link between insomnia unrelated to medical disorders and a shift in the Th1/Th2 balance toward Th2 dominance, indicating that the relationship between sleep quality and the etiology of immune-related diseases should be reconsidered.
Effect of Interleukin 1β on the HPA Axis in H1-Receptor Knockout Mice
Authors: Toftegaard C.L. , Knigge U. , Kjær A. , Watanabe T. , Friis-Hansen L. , Warberg J.
Published: August 2003

Objectives and Methods: Circulating cytokines such as interleukin-1 (IL-1), and tumor necrosis factor-alpha as well as lipopolysaccharide (LPS) are potent ACTH secretagogues, acting via stimulation of corticotropin-releasing hormone (CRH) and vasopressinergic neurons in the paraventricular nucleus of the hypothalamus (PVN). Histamine (HA) has been shown to stimulate ACTH secretion in rats, an effect in part mediated by CRH and arginine vasopressin (AVP). We have previously shown that inhibition of neuronal HA synthesis or central blockade of H1 receptors (H1R) decreased the ACTH response to LPS in male rats. To further elucidate the role of neuronal HA in cytokine-induced activation of the HPA axis, we compared the effect of H1R knockout on IL-1β-induced ACTH secretion in adult male mice. Results: In H1R knockout mice, ACTH secretion increased from basal levels of 261 to 492 pmol/l in response to IL-1β whereas the cytokine-induced ACTH secretion increased from 140 to 406 pmol/l in wild-type mice. Plasma corticosterone (CORT) rose from basal levels of 99 to 831 nmol/l in knockout mice upon IL-1β stimulation, whereas in wild-type mice CORT levels rose from 112 to 841 nmol/l. There was no significant difference in IL-1β-stimulated plasma ACTH or CORT levels between wild-type and knockout mice. Furthermore, there was no significant difference in basal or IL-1β-stimulated hypothalamic levels of histamine and tele-methyl-histamine between wild-type and knockout mice. HDC gene expression was significantly lower in knockout mice than in wild-type mice both under basal and IL-1β-stimulated conditions, while there were no significant differences in CRH gene expression in the PVN in knockout mice under basal and IL-1β-stimulated conditions. Increased basal expression of AVP in the PVN of knockout mice was observed in this study compared to wild-type mice. Conclusion: We conclude that the lack of the gene for histamine H1R does not seem to be crucial for the ACTH and CORT response to IL-1β, either due to possible functional compensation in the H1R knockout mouse or due to activation of pathways other than the neuronal histaminergic system.
Alzheimer’s Disease Patients Display Gender Dimorphism in Circulating Anorectic Adipokines
Authors: Intebi Alberto D. , Garau Laura , Brusco Ignacio , Pagano Miguel , Gaillard Rolf C. , Spinedi Eduardo
Published: August 2003

Among neurodegenerative diseases, Alzheimer’s disease (AD) is a leading cause of death in elderly individuals. AD is characterized, among other clinical findings, by unexplained weight loss, cachexia and altered immune function. To explore whether any relationship between gender and circulating levels of several eating-controlling metabolites exist, we evaluated leptin, tumor necrosis factor (TNF)-α, triiodothyronine (T3), free (F) thyroxine (T4), TSH, PRL, insulin (INS), and cortisol in 15 AD-treated patients (age range 55–82 years): 9 postmenopausal females (without hormone replacement therapy) and 6 males. The results (mean ± SEM) indicated that circulating leptin levels were significantly (p < 0.05) higher in female AD (40.34 ± 11.1 ng/ml) than in male AD (6.07 ± 1.39 ng/ml) patients. The difference found in circulating leptin levels was noticed regardless of BMI (26.75 ± 1.77 and 24.55 ± 1.93 kg/m2, in females and males, respectively) and waist:hip ratios (0.91 ± 0.03 and 0.94 ± 0.02, in females and males, respectively). Moreover, serum TNF-α concentrations were also significantly (p < 0.02) higher in AD females (12.24 ± 1.47 pg/ml) than in AD males (6.62 ± 1.44 pg/ml), regardless of TNF-α:BMI ratios (0.50 ± 0.09 and 0.28 ± 0.08, in females and males, respectively; p > 0.05). Finally, no differences were observed between gender (in female and male AD patients, respectively) in circulating levels of T3 (151.33 ± 9.91 vs. 116 ± 17.04 ng/dl), FT4 (1.26 ± 0.08 vs. 1.24 ± 0.06 ng/dl), TSH (1.28 ± 0.16 vs. 2.46 ± 0.67 µIU/ml), PRL (10.53 ± 2.47 vs. 12.61 ± 2.37 ng/ml), INS (11.76 ± 1.95 vs. 8.59 ± 1.34 µIU/ml) and cortisol (15.71 ± 1.23 vs. 12.63 ± 1.47 µg/dl). These results indicate that our AD group of patients, with normal corticoadrenal and thyroid functions and normoprolactinemia, displayed a gender-related characteristic in the circulating levels of two very important anorectic signals, leptin and TNF-α, being both higher in female than in male AD patients, regardless of BMI. Our study suggests that increased circulating levels of both anorexigenic adipokines may contribute to the metabolic changes observed in AD females.
Chronic Mild Stress in Mice Decreases Peripheral Cytokine and Increases Central Cytokine Expression Independently of IL-10 Regulation of the Cytokine Network
Authors: Mormède Cécile , Castanon Nathalie , Médina Chantal , Moze Elisabeth , Lestage Jacques , Neveu Pierre J. , Dantzer Robert
Published: August 2003

Objectives:  Accumulating evidence indicates that stress leads to an increased expression of pro-inflammatory cytokines such as interleukin (IL)-6. The production and action of pro-inflammatory cytokines are down-regulated by anti-inflammatory cytokines such as IL-10. This makes IL-10-deficient mice a potentially useful model to assess the effects of stress on cytokine production. Methods: In the present study, IL-10-deficient mice were compared to wild-type mice in their behavioural and cytokine response to a chronic mild stress procedure. Results: The 3-week chronic mild stress decreased body weight gain and sucrose consumption. It also resulted in a decreased expression of peripheral IL-1β and IL-6 and an increased expression of brain IL-6. This last change in IL-6 was correlated to body weight loss in stressed mice. However, IL-10-deficient mice did not differ from wild-type mice in their response to the chronic mild stress procedure, despite substantial differences in functioning of the cytokine network. Conclusion: These results are interpreted in the context of the relationship between cytokines and behaviour.
Inhibition of Constitutive Nitric Oxide Production Increases the Severity of Lipopolysaccharide-Induced Sickness Behaviour: A Role for TNF-α
Authors: Connor Thomas J. , O’Sullivan Joan , Nolan Yvonne , Kelly John P.
Published: August 2003

Administration of bacterial lipopolysaccharide (LPS) to rodents induces hypophagia, body weight loss and hypolocomotion, a constellation of symptoms collectively referred to as ‘sickness behaviour’. We examined the role of the gaseous transmitter nitric oxide (NO) in mediating LPS-induced sickness behaviour in rats. Treatment with the non-selective NO synthase (NOS) inhibitor NG-nitro-L-arginine (L-NA) (20 mg/kg; i.p.) increased the severity of LPS-induced sickness behaviour in rats, suggesting that endogenous NO does not act as a mediator of LPS-induced sickness behaviour, but may rather have a protective role, acting in an inhibitory feedback manner to limit LPS-induced sickness. To evaluate the role of the different NOS isoforms in this response, we examined the effect of the neuronal NOS inhibitor, 7-nitroindazole (7-NI; 25 and 50 mg/kg; i.p.), and the inducible NOS inhibitor, aminoguanidine (AGN; 50 and 100 mg/kg; i.p.). Neither 7-NI nor AGN significantly altered LPS-induced sickness behaviour. Therefore, it is likely that the endothelial isoform of NOS mediates the effect of L-NA on LPS-induced sickness behaviour. As pro-inflammatory cytokines are mediators of LPS-induced sickness behaviour, we examined the effect of L-NA (20 mg/kg; i.p.) on LPS-induced interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α production. L-NA increased LPS-induced TNF-α without significantly altering IL-1β or IL-6 production. Moreover, pre-treatment with the TNF-α inhibitor pentoxyfilline (25 mg/kg; i.p.) largely reversed the augmenting effect of L-NA on LPS-induced sickness behaviour, suggesting that the ability of L-NA to increase TNF-α production underpinned its ability to increase the severity of sickness. In conclusion, L-NA increases the severity of LPS-induced sickness behaviour, most likely by blocking the tonic inhibitory action of constitutively produced NO on TNF-α production.
Alternative Methods for Evaluating Skin Irritation Using Three-Dimensional Cultures
Authors: Eun Hee Chul , Nam Chunja
Published: August 2003

The Draize test has long been used as a method to evaluate skin irritancy. However, alternative methods have since been developed, in response to pressure from the ever-increasing movement of animal protectionists. Cell culture represents the most promising alternative method, and many trials of various kinds are under way, for example the monolayer culture, skin explant culture and three-dimensional skin equivalent culture. It is quite likely that better-qualified three-dimensional culture systems constitute the final goal in the search for alternative methods to evaluate skin irritancy. However, its effective validation will require not only further large-scale studies, but also the development of superior artificial skin models, with properties more closely resembling those of normal skin. In this review, we focus mainly on the skin equivalent culture method for measuring skin irritancy. Its superiority to other models as well as its problems and limitations are discussed.
Disperse Dye Dermatitis: Clinical Aspects and Sensitizing Agents
Authors: Giusti Francesca , Seidenari Stefania
Published: August 2003

Reports on contact sensitization to disperse dyes are increasing, although its true incidence is not known. In fact, the diagnosis of textile contact dermatitis may be difficult because of its clinical polymorphism, including unusual clinical patterns and unexpected localizations. This review summarizes literature data referring to clinical aspects of allergic dermatitis due to disperse dyes and presents our data on this issue. Based on our findings, two different clinical subtypes of disperse dye dermatitis can be identified: an ‘eczematous’ and an ‘oedematous plaque’ type. The former is characterized by eczematous lesions in patients sensitized to disperse dyes, but frequently to other haptens too. The ‘oedematous-plaque’ type, mainly associated with disperse blue sensitization, includes unusual clinical aspects. However, its localization to skin sites of friction or sweating may induce the suspicion of a textile dye dermatitis.
Surface of Textiles and the Human Skin
Authors: Knittel D. , Buschmann H.-J. , Textor T. , Schollmeyer E.
Published: August 2003

A report is given on new methods of surface modification of near-skin textiles. These modifications include the use of cyclodextrins, linear carbohydrate biopolymers and inorganic/organic hybrid networks; all of them can be permanently fixed on the textile for multiple uses. Textiles finished in this way may be used as transdermal therapeutic systems after loading with pharmaceuticals or as transdermal collector systems for stabilizing and analysing sweat components or as a means to regulate the skin climate.
Surface of Textiles and the Human Skin
Authors: Knittel D. , Beermann K. , Schollmeyer E.
Published: August 2003

In vitro testing methods for the evaluation of potential skin hazards due to chemicals released from textiles or textile auxiliaries are presented and discussed in order to establish further focussed research.
Attenuation of Surfactant-Induced Interleukin 1α Expression by Zinc Pyrithione
Authors: Warren Raphael , Schwartz James R. , Sanders Linda M. , Juneja Prem S.
Published: August 2003

Background: Dandruff is believed to be a fungus-mediated disease which responds to the topical delivery of antifungal agents. Although the primary causative factor is fungus related, distal events include an inflammatory cascade that eventually expresses itself as corneocyte flakes. The most common vehicle for dandruff treatment includes surfactants (i.e. shampoos), which as a chemical group have the potential to promote dermatitis. Objective: To evaluate the effect of antidandruff agents and antimicrobials on the potential contact irritancy of surfactants. Methods: Excretion of interleukin 1α by human skin equivalent cultures was measured after topical application of test materials. Results: Zinc pyrithione specifically reduces surfactant-induced expression of interleukin 1α. Neither its sodium salt nor other antimicrobial/antifungal agents had a similar effect. Conclusion: These data suggest that in addition to its known antifungal activity, zinc pyrithione may provide an additional benefit by reducing the potential irritancy of surfactant vehicles.
Aluminum Chloride: Is It Useful for Skin Protection in Occupational Dermatology?
Authors: Gloor M. , Haus J.
Published: August 2003

Purpose of the Study: To determine the effect of pretreatment with 5% aluminum chloride hexahydrate solution and occlusive film dressings on stratum corneum hydration and barrier function. Procedures: Twenty subjects were treated with 5% aluminum chloride hexahydrate solution (versus water) 3 times at 12-hour intervals, followed by 24 h of occlusion. Outcome measures were the effects of this treatment on stratum corneum moisture content, transepidermal water loss (TEWL), hydrocortisone blanching and skin irritation in the sodium lauryl sulfate (SLS) irritation test. Results: Aluminum chloride significantly (versus water) prevented occlusion-induced increases in corneometric measurement values and TEWL and significantly (versus water) reduced corticosteroid penetration in the blanching test but had no significant effect on skin irritation in the SLS irritation test. Conclusions and Message: Five percent aluminum chloride hexahydrate solution reduces the water content of the stratum corneum under occlusive conditions. An increased water content of the stratum corneum is obtained in persons suffering from hyperhidrosis and under protective gloves. While improving stratum corneum barrier integrity as such, aluminum chloride fails to protect the stratum corneum barrier against irritation induced by surfactants.
Functional Analysis of the Stratum corneum of Patients with Atopic Dermatitis: Comparison with Psoriasis vulgaris
Authors: Kobayashi H. , Tagami H.
Published: August 2003

Background: The skin of patients with atopic dermatitis (AD) is known to have a defective barrier function of the stratum corneum (SC) that facilitates the induction of unique skin hypersensitivity to various environmental allergens and irritants. However, it has not been determined whether there are characteristics unique to AD, because an apparently similar dysfunction of the SC is also observable in other inflammatory dermatoses such as psoriasis. Objective: Our purpose was to analyze the SC functions of patients with AD in comparison with those with psoriasis, an endogenously induced immune-mediated dermatosis. Methods: We conducted functional analyses of the lesional and nonlesional skin of AD and psoriasis patients by using noninvasive biophysical methods. Results: When we classified their skin changes into several subtypes based on the clinical features, we found that a severity-dependent disruption in the barrier function as well as a decrease in the SC hydration occurred in both dermatoses and to a similar degree. The extent of their SC barrier damage on the skin of the trunk and limbs was almost comparable to that of normal facial skin of healthy individuals. We also found similarly small, immature corneocytes that are associated with epidermal hyperproliferation accompanied by poor differentiation in both dermatoses. Moreover, we found similar but much milder SC functional abnormalities in the nonlesional skin where the extent of the dysfunction was much closer to that of healthy skin than to that of lesional skin. Conclusion: From these data, we could not find any differences in the functional abnormalities of the SC of AD patients that would justify considering it to be a unique dermatosis at least in terms of barrier damage. Because the presence of smaller corneocytes reflects the active proliferation of the underlying epidermis, we think that the barrier impairment and deficient water-holding capacity of the SC develop as a result of the enhanced epidermal proliferation in both dermatoses that is caused by the underlying inflammation.
Application of in vitro Monolayer and Three-Dimensional Culture Systems to Evaluate the Irritancy of Cosmetic Constituents
Authors: Suh D.H. , Han J.H. , Park K.C. , Eun H.C.
Published: August 2003

Background: For testing skin irritancy, many cytotoxicity tests have been carried out and evaluated. It is evident that human subjects cannot be used as the initial experimental subjects. Therefore, several models, including monolayer and three-dimensional cultures, have been tested to measure skin irritancy. Objective: This study was done to compare several alternative in vitro methods used for evaluating the irritancy of cosmetic constituents. Methods: Cytotoxicity was measured by checking ED50 values with the MTT assay. The irritancy ranking of the five irritants was analyzed using the ED50 values. Results: In terms of irritancy ranking, good correlations were obtained between the monolayer and three-dimensional culture systems, although the concentrations of irritants needed to obtain the ED50 values differed considerably. Conclusion: These findings suggest that caution is necessary in the evaluation of the results of such tests, because the concentration of irritants needed to obtain the ED50 values may differ depending on the culture model used.
Cerebral Vascular Responses to Changes in Carbon Dioxide Tension in Term and Preterm Infants with Apnea
Authors: Koons Anne , Hegyi Thomas , Mehta Rajeev , Hiatt Mark , Weinberger Barry
Published: August 2003

Carbon dioxide (CO2) plays important roles in regulating both respiratory drive and cerebral blood flow. These effects are mediated, in part, by activity of the sympathetic nervous system. We hypothesized that the presence of acute life-threatening events or apnea in term or preterm infants, respectively, would serve as a marker for immaturity of cerebral autonomic innervation and that such infants would display a reduced cerebral vascular response to elevated pCO2. Therefore, we evaluated the cerebral vascular response during CO2 challenge tests in groups of term and preterm infants with primary apnea. In term infants (39 ± 2 weeks gestation) with acute life-threatening events, elevated pCO2 was accompanied by decreasing pulsatility index and increasing mean anterior cerebral blood flow velocity. However, in preterm infants (29 ± 2 weeks’ gestation) with apnea, pulsatility index and anterior cerebral artery flow velocity did not significantly change in response to CO2 supplementation. We conclude that preterm, but not term, infants with apnea exhibit impaired vascular responses to hypercarbia.