bluuebunny/crossref_metadata_2025_split huggingface dataset:
Skin aging induced by ultraviolet exposure and tobacco smoking: evidence from epidemiological and molecular studies
Authors: Yin Lei , Morita Akimichi , Tsuji Takuo 
Published: March 2003

Background: Tobacco smoking, similar to ultraviolet (UV) A radiation exposure, has previously been identified as an important factor contributing to premature aging of human skin.Objective and design:To investigate the relationship between these two environmental factors, we have conducted a cross‐sectional study of 83 subjects (48 males, 35 females, age range 23–95), in which sun exposure, pack‐years of smoking history and potential confounding variables were assessed by questionnaire. Facial wrinkles were quantified using the Daniell score. In order to study the molecular mechanism by which smoking caused wrinkle formation, in vitro studies were conducted to assess the alteration of matrix metalloproteinase‐1 (MMP‐1) mRNA expression in human fibroblasts stimulated with tobacco smoke extract or/and UVA.Results: Logistic statistic analysis of the data revealed that age [odds ratio (OR)=7.5, 95% confidence interval (CI)=1.87–30.16], pack‐years (OR=5.8, 95% CI=1.72–19.87), and sun exposure (OR=2.65, 95% CI=1.0–7.0) independently contributed to facial wrinkle formation. When excessive sun exposure (>2 h/day) and heavy smoking (35 pack‐years) occurred together, the risk for developing wrinkles was 11.4 times higher than that of non‐smokers and those with less sun exposure (<2 h/day) at the same age. The in vitro studies revealed that MMP‐1 expression was significantly increased in fibroblasts after the stimulation with either tobacco smoke extract or UVA. Maximum induction was observed when cells were treated with tobacco smoke extract plus UVA, indicating that the two factors act in an additive manner. MMP‐1 induction was significantly higher in the low glutathione (GSH) content fibroblast compared to that in the high GSH fibroblast, indicating that the differences in glutathione content define the susceptibility of fibroblasts towards UV‐ or tobacco smoking‐induced MMP‐1 expression.Conclusion: Tobacco smoke and UVA cause wrinkle formation independently of each other. We propose that both factors cause aging of human skin through additive induction of MMP‐1 expression.
Photoonycholysis
Authors: Baran Robert , Juhlin Lennart 
Published: March 2003

Background/Purpose: Photoonycholysis may be seen as a part of Segal's triad, photosensitivity followed by discoloration of the nails and onycholysis. But the latter may also appear, independently, in the absence of photosensitive reaction elsewhere.Methods: Photoonycholysis may result from drug intake, porphyria cutanea tarda, erythropoietic porphyria, erythropoietic protoporphyria, variegate porphyria and pseudoporphyria. Rarely, spontaneous photoonycholysis may be observed.Results: Four distinct subtypes have been recorded without relationship between the responsible drugs and the different clinical varieties of photoonycholysis. Primary photohemorrhage can occur; it can also be associated with polydactylous photoonycholysis type III.Conclusion: The inability to reproduce photoonycholysis experimentally should be emphasized.
Protective effect of melatonin and its precursor L‐tryptophan on acute pancreatitis induced by caerulein overstimulation or ischemia/reperfusion
Authors: Jaworek Jolanta , Leja‐Szpak Anna , Bonior Joanna , Nawrot Katarzyna , Tomaszewska Romana , Stachura Jerzy , Sendur Ryszard , Pawlik Wiesław , Brzozowski Tomasz , Konturek Stanisław J. 
Published: March 2003

Abstract: Melatonin, a pineal secretory product, synthesized from l‐tryptophan, has received increased attention because of its antioxidative and immunomodulatory properties. It has been detected in the gut and shown to protect the gastric mucosa, and liver from acute damage, but the role of melatonin in the protection of the pancreas against acute inflammation is not clear. The aim of this study was to investigate the effects of melatonin and its precursor, l‐tryptophan, on caerulein‐induced pancreatitis (CIP) and on ischemia/reperfusion (I/R)‐provoked pancreatitis in rats. CIP was induced by subcutaneous infusion of caerulein to the rats (25 μg/kg). I/R was induced by clamping of the inferior splenic artery for 30 min followed by 2 hr of reperfusion. Melatonin (10, 25 or 50 mg/hr) or l‐tryptophan (50, 100 or 250 mg/kg) was given as a bolus intraperitoneal (i.p.) injection 30 min prior to the onset of pancreatitis. CIP and I/R were confirmed by histologic examination and manifested by typical pancreatic edema, by an increase of plasma levels of amylase (by 500% in CIP and by 40% in I/R) and the pro‐inflammatory tumor necrosis factor α (TNFα) (by 500%). Lipid peroxidation products such as malondialdehyde (MDA) and 4‐hydroxynonenal (4‐HNE), were increased several fold in the pancreas CIP and I/R, whereas pancreatic blood flow (PBF) was significantly reduced in these animals. Pretreatment of rats subjected to CIP or to I/R with melatonin (25 or 50 mg/kg i.p.) or l‐tryptophan (100 or 250 mg/kg i.p.) significantly reduced pancreatic edema, plasma levels of amylase and TNFα and diminished pancreatic MDA + 4‐HNE contents, while enhancing PBF, pancreatic integrity and plasma levels of the anti‐inflammatory interleukin 10 (IL‐10). This was accompanied by a marked and dose‐dependent rise of plasma melatonin immunoreactivity. Gene expression of N‐acetyl transferase, an enzyme involved in melatonin biosynthesis, was detected in the pancreas of normal rats and was significantly enhanced in the rats with CIP. We conclude that exogenous melatonin, and that produced from l‐tryptophan, attenuates pancreatic damage induced by CIP or by I/R and this effect may be attributable to the reduction in lipid peroxidation and TNFα release combined with an increase of plasma anti‐inflammatory IL‐10 in rats with acute pancreatitis.
A comparative study of the effects on the skin of a classical bar soap and a syndet cleansing bar in normal use conditions and in the soap chamber test
Authors: Barel A. O. , Lambrecht R. , Clarys P. , Morrison B. M. , Paye M. 
Published: March 2003

Background/aims: The skin irritation potential of a body cleansing product is often compared under exaggerated test conditions, although the product is intended to be used at home with repetitive and brief contact with the skin. The aim of this study was to determine how much patch testing is predictive of the clinical, sub‐clinical and subjective cutaneous effects of products used at home by consumers for their normal hygienic cleansing.Methods: A double‐blind comparative study of the normal use of an alkaline soap bar and a syndet at home during 10 consecutive weeks was performed on two identical groups of 25 healthy female subjects. The eventual skin changes observed at different anatomical skin sites were evaluated by clinical visual examination and by bioengineering measurements before the start of the study and then every 2 weeks. The objective measurements were compared with the subject’s perceptions of dryness, tightness and product irritancy during the testing.Results: The bioengineering measurements did not show any significant changes on all the anatomical skin sites, except for a small increase in skin pH with the classical soap bar. However, a trend appeared, showing that the alkaline soap bar is perceived by the subjects themselves as more of an irritant than the syndet bar. In the soap chamber test, the bar soap showed a significantly higher irritancy than the syndet bar.Conclusion: This study showed that cutaneous irritation induced by cleansing products in patch testing is not necessarily predictive of the irritation likely to occur in normal use conditions. Finally, a clear relationship could be demonstrated between the results of the soap chamber test and the consumer perception of both cleansing bars.
Graphic analysis of the relationship between skin colour change and variations in the amounts of melanin and haemoglobin
Authors: Takiwaki H. , Miyaoka Y. , Kohno H. , Arase S. 
Published: March 2003

Background/aims The L*a*b* coordinate is the most commonly used colour system to measure skin colour in dermatology and cosmetology. In this system, a* and L* are often used for quantification of the degrees of erythema and pigmentation. The aim of this study was to examine whether a* and L* can be used as specific scales to indicate the amount of haemoglobin and melanin, respectively, in the skin.Methods The a* and L* values were examined with a reflectance spectrometer in various skin conditions or lesions caused by a change in the amount of either melanin or haemoglobin, i.e. vitiligo, ultraviolet‐induced pigmentation (PG), erythema resulting from slapping (ER), corticosteroid‐induced blanching, erythema due to stasis by arm lowering, and a combination of PG and ER. The differences in values between the test sites and the adjacent normal skin, Δa* and ΔL*, were plotted on the Δa*–ΔL* plane and analysed statistically and geometrically.Results L* depended substantially not only on melanin but also on haemoglobin, especially if the oxygen saturation level was expected to be low. a* was also influenced by melanin. The results of graphic analysis indicated that a linear transformation of (Δa*, ΔL*) into (ΔHb = 1.68 Δa* + 0.60 ΔL*, ΔMel =−1.06 Δa*–1.44 ΔL*) was suitable for separately estimating the change in the amount of haemoglobin (ΔHb) and in that of melanin (ΔMel).Conclusion The results of this study may be of value for understanding the relationship between colour coordinates of the skin and the quantities of haemoglobin and melanin, and may be of use when pigmented lesions of the face are monitored by tristimulus colourimetry, as facial skin colour is affected considerably by the rich and easily variable cutaneous blood flow.
Melanoma or pigmented basal cell carcinoma: a clinical‐pathologic correlation with dermoscopy, in vivo confocal scanning laser microscopy, and routine histology
Authors: Charles Carlos A. , Marghoob Ashfaq A. , Busam Klaus J. , Clark‐Loeser Lesley , Halpern Allan C. 
Published: March 2003

Background/purpose: New techniques are being explored for improving diagnostic accuracy of pigmented skin lesions. Confocal scanning laser microscopy (CSLM) may represent such a novel technique. The purpose of this report was to demonstrate the potential application of CSLM as an aid in the diagnosis of a pigmented skin lesion that is clinically suspicious for melanoma.Methods: An irregular pigmented lesion was examined clinically and dermoscopically. The lesion was imaged by CSLM and subsequently excised for histologic examination. Findings from CSLM were correlated with features observed on the dermoscopic and histologic examination.Results: Confocal scanning laser microscopy (CSLM) allowed for the non‐invasive visualization of the histologic features of superficial pigmented BCC, including buds and “islands” of tumor cells at the dermoepidermal junction and melanin‐laden macrophages. Conventional histology confirmed the diagnosis of pigmented BCC.Conclusion: Confocal scanning laser microscopy (CSLM) may serve as an aid in the non‐invasive diagnosis of pigmented skin lesions clinically suspicious for melanoma.
Quantitative description of human skin water dynamics by a disposition‐decomposition analysis (DDA) of trans‐epidermal water loss and epidermal capacitance
Authors: Rodrigues Luis Monteiro , Pinto Pedro Contreiras , Pereira Luis Marcelo 
Published: March 2003

Background: In vivo water assessment would greatly benefit from a dynamical approach since the evaluation of common related variables such as trans‐epidermal water loss or “capacitance” measurements is always limited to instantaneous data. Mathematical modelling is still an attractive alternative already attempted with bi‐exponential empirical models. A classical two‐compartment interpretation of such models raises a number of questions about the underlying fundamentals, which can hardly be experimentally confirmed. However, in a system analysis sense, skin water dynamics may be approached as an ensemble of many factors, impossible to discretize, but conceptually grouped in terms of feasible properties of the system. The present paper explores the applicability of this strategy to the in vivo water dynamics assessment.Methods: From the plastic occlusion stress test (POST) skin water balance is assessed by modelling trans‐epidermal water loss (TEWL) and “capacitance” data obtained at skin's surface. With system analysis (disposition‐decomposition analysis) the distribution function, H(t), modelled as a sum of exponential terms, covers only the distribution characteristics of water molecules traversing the skin. This may correspond macroscopically to the experimental data accessed by “corneometry”. Separately, the hyperbolic elimination function Q(TEWL) helps to characterise the dynamic aspects of water influx through the skin.Discussion and conclusion: In the observable range there seems to be a linear relationship between the net amount of water lost at the surface by evaporation, and the capability of the system to replenish that loss. This may be a specific characteristic of the system related to what may be described as the skin's “intrinsic hydration capacity” (IHC) a new functional parameter only identified by this strategy. These new quantitative tools are expected to find different applicabilities (from the in vivo skin characterisation to efficacy testing) contributing to disclose the dynamical nature of the skin water balance process.
Congenital sinus of the upper lip with idiopathic precocious puberty
Authors: Sumitomo S , Ogawa S , Hirai K , Takai Y 
Published: March 2003

An extremely rare case of congenital sinus of the upper lip is presented in a 22‐year‐old woman with idiopathic precocious puberty. The sinus has a pin‐like orifice located in the midline of the upper lip philtum just below the base of the columella. Sexual precocity was found out when she was 7 years old. A series of exact examinations had been performed at that time. Neither neurogenic lesions of the central nervous system nor other systemic abnormalities were observed.
cDNA Array Analysis of Pineal Gene Expression Reveals Circadian Rhythmicity of the Dominant Negative Helix‐Loop‐Helix Protein‐Encoding Gene, Id‐1
Authors: Humphries A. , Klein D. , Baler R. , Carter D. A. 
Published: March 2003

AbstractThe pineal gland is a major output of the endogenous vertebrate circadian clock, with melatonin serving as the output signal. In many species, elevated nocturnal melatonin production is associated with changes in pineal gene expression. In the current study, cDNA array analysis was used in an attempt to identify additional genes that exhibit day/night differential expression in the rat pineal gland. This revealed 38 candidate genes, including Id‐1 (inhibitor of DNA binding and differentiation). Id‐1 encodes a helix‐loop‐helix (HLH) protein that lacks a basic DNA binding domain and could affect pineal physiology via a dominant negative trans‐acting regulatory activity. For this reason Id‐1 was selected for further analysis. Id‐1 was expressed in a major population of pineal cells and the Id‐1 protein was associated with a nuclear complex. The levels of Id‐1 mRNA and protein exhibit approximately six‐fold day/night rhythms. In contrast, the related genes Id‐2 and Id‐3 do not exhibit marked day/night differences in pineal expression. Rhythmic Id‐1 expression is primarily limited to a C‐terminally extended splice variant of Id‐1, which would restrict the functional output of the rhythm to protein binding partners of this isoform of Id‐1. Our findings add to the body of evidence indicating that transcriptional regulators play a role in neuroendocrine rhythms, and extend this by introducing the concept of a dominant negative HLH involvement. The rhythm in Id‐1 in the pineal gland provides an experimental opportunity to identify Id‐1‐binding partners which may also be involved in Id‐1 activity in other functional contexts.
Mitogen‐Activated Protein Kinase Mediates Epidermal Growth Factor‐Induced Morphogenesis in Pituitary GH3 Cells
Authors: Lewis M. D. , Ham J. , Rees D. A. , Lewis B. M. , Scanlon M. F. 
Published: March 2003

AbstractEpidermal growth factor (EGF) causes pituitary GH3 cells to change from their normal predominantly rounded morphology to much more elongated cells with extensive filopodia, and this effect is accompanied by a parallel increase in cell volume. In view of this, and because EGF receptor expression is increased in some pituitary tumours, we examined the mechanism of this EGF‐induced morphological effect as it may play a role in tumour invasiveness. The effect of treatment of the cells with EGF (1 nm, 4 days) was determined visually (expressed as percent non round cells) and by measuring the cell volume by Coulter Counter analysis. EGF treatment caused the cells to change their morphology with percent non round cells increasing from 37% in control cells to 74% in EGF‐treated cultures; this was accompanied by a parallel increase in cell volume. Treatment of the cells with EGF in the presence of the MEK1 inhibitor (PD98059) completely blocked the EGF‐induced morphological changes, showing that activation of the mitogen‐activated protein kinase (MAPK) pathway is necessary to mediate this effect. Transfection of the cells with a constitutively activated mutant of MEK1 produced a similar morphological change to that produced by EGF treatment, with the proportion of non round cells increasing to 62% with a parallel increase in cell volume compared to cells transfected with the empty vector, demonstrating that direct activation of MAPK pathway is sufficient to mediate the observed morphological effects. The effects produced by activated MEK1 transfection could be blocked by PD98059. EGF had opposing effects on prolactin and growth hormone (GH) secretion by the cells, increasing prolactin release and inhibiting GH release. Transfection of the cells with activated MEK1 produced similar effects on hormone release as EGF treatment. In conclusion, the morphological effects of EGF on GH3 cells are mediated by activation of the MAPK pathway as blockade of this pathway abolished the observed effect, and direct activation of this pathway by transfection with an activated mutant of MEK1 was able to duplicate these effects. This mechanism may contribute to the growth and possibly local invasiveness of some pituitary tumours that express the EGF receptor.
The role of glycine betaine in the protection of plants from stress: clues from transgenic plants
Authors: Sakamoto A. , Murata N. 
Published: March 2003

AbstractThe acclimation of a plant to a constantly changing environment involves the accumulation of certain organic compounds of low molecular mass, known collectively as compatible solutes, in the cytoplasm. The evidence from numerous investigations of the physiology, genetics, biophysics and biochemistry of plants strongly suggests that glycine betaine (GB), an amphoteric quaternary amine, plays an important role as a compatible solute in plants under various types of environmental stress, such as high levels of salts and low temperature. Plant species vary in their capacity to synthesize GB and some plants, such as spinach and barley, accumulate relatively high levels of GB in their chloroplasts while others, such as Arabidopsis and tobacco, do not synthesize this compound. Genetic engineering has allowed the introduction into GB‐deficient species of biosynthetic pathways to GB from both micro‐organisms and higher plants; this approach has facilitated investigations of the importance of GB in stress protection. In this review, we summarize recent progress in the genetic manipulation of the synthesis of GB, with special emphasis on the relationship between the protective effects of GB in vivo and those documented in vitro.
Effects of long‐term exposure to elevated CO2 and N fertilization on the development of photosynthetic capacity and biomass accumulation in Quercus suber L.
Authors: Maroco J. P. , Breia E. , Faria T. , Pereira J. S. , Chaves M. M. 
Published: March 2003

AbstractThe effects of long‐term (4 year) CO2 enrichment (70 Pa versus 35 Pa) and nitrogen nutrition (8 mm versus 1 mm NO3–) on biomass accumulation and the development of photosynthetic capacity in leaves of cork oak (Quercus suber L., a Mediterranean evergreen tree) were studied. The evolution of photosynthetic parameters with leaf development was estimated by fitting the biochemical model of Farquhar et al. (Planta 149, 78–90, 1980) with modifications by Sharkey (Botanical Review 78, 71–75, 1985) to A–Ci response curves. CO2 enrichment had a small reduction effect on the development of the maximum CO2 fixation capacity by Rubisco (VCmax), and no effect over maximum electron transport capacity (Jmax), day‐time respiration (Rd) and Triose‐P utilization (TPU). However, there was a statistically significant effect of N fertilization and the interaction CO2 × N over the evolution of VCmax, Jmax and TPU. Relative stomatal limitation (estimated from A–Ci curves) was higher (+20%) for plants grown under ambient CO2 than for plants grown under elevated CO2. There was a significant effect of CO2 and N fertilization over total biomass accumulation as well as leaf area. Plants grown at elevated CO2 had 27% more biomass than plants grown at ambient CO2 when given high N. However, for plants grown under low N there was no significant effect of CO2 enrichment on biomass accumulation. Plants grown under low N also had significantly higher root : shoot ratios whereas there were no differences between CO2 treatments. The larger biomass accumulation of Q. suber under elevated CO2 is attributable to a higher availability of CO2 coupled to a larger leaf area, with no significant decrease in photosynthetic capacity under CO2 enrichment and elevated N fertilization. For low N fertilization, the effects of CO2 enrichment over leaf area and biomass accumulation are lost, suggesting that in native ecosystems with low N availability, the effects of CO2 enrichment may be insignificant.