bluuebunny/crossref_metadata_2025 huggingface dataset:
Several antioxidant pathways are involved in astrocyte protection by melatonin
Authors: Martín Vanesa , Sainz Rosa M. , Antolín Isaac , Mayo Juan C. , Herrera Federico , Rodríguez Carmen
Published: March 2003

Abstract: Neuroprotection provided by melatonin has been shown to be more relevant in vivo than in neuronal cultures. Given the role of astrocytes in neuronal support and protection, studies were initiated to elucidate the possible protective effect of the antioxidant melatonin against oxidative stress in these cells. Both low and high concentrations of melatonin were able to protect astrocytes with even higher efficiency than the known antioxidant glutathione (GSH). The mechanisms involved may be different for high (1 mm) and low (100 nm) concentrations of the indole. The GSH cycling appeared not to be involved in the protection at high doses. High doses of melatonin neither influenced GSH levels nor gene expression for the several antioxidant enzymes studied; thus, melatonin's protective effect was likely because of its free radical scavenging action in this case. However, melatonin concentrations in the nanomolar range require the presence of GSH to be effective. No increase in GSH synthesis was found, but low doses of melatonin increased gene expression and activity of glutathione peroxidase. As this enzyme requires GSH as substrate to be active, this may be the reason why the effect of this melatonin concentration is GSH dependent. In vivo, melatonin levels exhibit a wide range of concentrations with much lower levels in the blood and significantly higher concentrations in other body fluids and within cells. Thus, melatonin may normally function as an indirect and direct antioxidant in vivo.
Effects of endurance training on tissue glutathione homeostasis and lipid peroxidation in streptozotocin‐induced diabetic rats
Authors: Gul* Mustafa , Laaksonen David E. , Atalay Mustafa , Vider Lena , Hänninen Osmo
Published: March 2003

The aims of our study were to assess whether endurance training strengthens glutathione‐dependent antioxidant defenses and decreases oxidative stress in experimental diabetes. Streptozotocin‐induced diabetic rats were divided into trained and untrained groups, which were further divided into resting and acute exercise groups. Endurance training consisted of treadmill running for 8 weeks. For acute exhaustive exercise, graded treadmill running was conducted until exhaustion. Eight weeks' treadmill training increased the endurance, favorably decreased lipid peroxidation as measured by thiobarbituric acid reactive substances but not conjugated dienes levels in kidney and vastus lateralis muscle and upregulated glutathione peroxidase in red gastrocnemius muscle. However, it adversely decreased total glutathione level and glutathione peroxidase activity in kidney. Acute exhaustive exercise up‐regulated glutathione peroxidase activity in liver. Endurance training did not prevent the increase in thiobarbituric acid reactive substances level in liver due to acute exhaustive exercise. Activities of glutathione disulfide reductase and glutathione S‐transferase were not affected. Even though endurance training appeared to upregulate glutathione dependent antioxidant defense in skeletal muscle and to decrease lipid peroxidation in kidney and vastus lateralis muscle as measured by TBARS, our results suggests that beneficial effects of 8 weeks of endurance training are limited in this rat model of uncontrolled diabetes mellitus.
Imaging, image processing and pattern analysis of skin capillary ensembles
Authors: Zhong Jicun , Asker Claes L. , Salerud E. Göran
Published: March 2003

Background/aims: The capillary bed is recognized as the site where metabolic and nutrient processes occur for living tissues at all levels. The evaluation of this vital process is a major concern in microcirculation. Unlike traditional approaches that concentrated on the extreme local properties of this process, a more global analysis toward capillary ensembles is employed here, since capillaries work as a cooperative entirety. As a first step toward ensemble analysis, the static and planar geometric parameters are investigated. Parameters such as the capillary adjacency and size information are very important in predicting and analysing certain malfunctions in the microvascular bed.

Methods/results: In order to achieve an objective and accurate analysis of these vital parameters, a computerized imaging system is proposed. Not only the number of capillaries and the capillary cross‐sectional areas are important in describing the microvascular bed but the planar distribution pattern of the capillaries also carries valid information. This information, unique to the ensemble analysis, can be used to reveal, visualise and quantify the clustering of capillaries; and this information, according to the Krogh model, is fundamental in estimating the tissue oxygen supply. Two spatial models, the closest neighbor and triangulation methods, have been applied to the captured images of capillary ensembles. The closest neighbor technique generates a minimal distance map or displays a distribution, which depicts the local clustering of capillaries. The triangulation technique, on the other hand, generates a mutual distance map, which is a global description of the capillary positions. Triangulation methods have been evaluated but all except the Greedy triangulation method have been rejected due to lack of robustness and model weakness. Therefore, the capillaries are triangulated by the Greedy triangulation method, and the capillary distribution uniformity is defined as one minus the coefficient of variance of the edge lengths of the mutual distance map.

Conclusions: A series of advanced image processing methods have been developed that efficiently extract the capillary position, size and distribution information from the images. These results facilitate the automatic counting of capillaries and the capillary size‐related pathological analysis.
Axillary pH and influence of deodorants
Authors: Stenzaly‐Achtert S. , Schölermann A. , Schreiber J. , Diec K. H. , Rippke F. , Bielfeldt S.
Published: March 2003

Background/aims: In moist intertriginous regions, such as the armpit, the pH value is physiologically higher than in other skin regions. The regulation of the axillary pH‐value was examined in an open study with 48 subjects in three groups with n=16 each.

Methods: In the first 10 days (run‐in) the subjects received a standard treatment in the axilla with shaving, cleansing and application of a pH‐neutral deodorant. This was followed by a 5 day treatment period with the three test products (pH5 Eucerin® Deodorant Roll‐on, Deodorant Balsam Spray, Deodorant Cream). The study was concluded by a wash‐out period with procedures identical to the run‐in phase. The pH was measured with a calibrated pH‐meter.

Results: A significant pH reduction was shown during the treatment period when compared to the run‐in phase. The Deodorant Roll‐on induced a reduction of the mean pH values from 6.1 to 5.3, the Deodorant Balsam Spray from 6.5 to 5.7 and the Deodorant Cream from 6.2 to 5.3. During the wash‐out period all pH values returned to baseline.

Conclusion: All of the deodorants tested demonstrated a significant reduction in axillary pH. There is evidence that a high skin pH promotes the growth of several microorganisms that produce malodor. Therefore, the regulation of pH may contribute to the deodorant efficacy of the test products.
High‐frequency ultrasound imaging of the skin during normal and hypertensive pregnancies
Authors: Mirpuri N. G. , Dyson M. , Rymer J. , Bolton P. A. , Young S. R.
Published: March 2003

Background/aims: Diagnosis of preeclampsia is currently made from blood pressure measurements taken at antenatal visits (either at the hospital or in the community). The aim of this work was to see whether the presence of underlying hypertensive diseases is accompanied by changes in the skin of pregnant women, which can be visualized using high‐frequency diagnostic ultrasound.

Method: This was a prospective study of pregnant and non‐pregnant, hypertensive and non‐hypertensive patients visiting the outpatient department of a central London Teaching Hospital. The study group consisted of 93 women, of which 30 were non‐hypertensive in the second trimester of pregnancy, 26 were non‐hypertensive in the third trimester of pregnancy, 9 were hypertensive in the second trimester of pregnancy, and 14 were hypertensive in the third trimester of pregnancy. Fourteen non‐pregnant women of comparable age were recruited as controls. Changes in abdominal skin thickness and also skin structure, as analysed by fractal image analysis, was assessed in each patient.

Results: In a normal pregnancy, abdominal skin gets thinner as pregnancy progresses. In hypertensive patients, the skin thickness did not appear to alter. Image analysis of abdominal skin scans showed that the skin of non‐hypertensive pregnant women and non‐pregnant women are different. Whereas the analysis of hypertensive pregnant women and non‐pregnant women showed they were the same.

Conclusions: The data used to compare the groups indicates that if the abdominal skin of the patient does not get thinner as the pregnancy progresses there is an indication that the patient may be hypertensive. The fractal data comparing the groups indicates the following when comparing a patient’s fractal signature with the non‐pregnant control data: If the abdominal fractal for a pregnant woman is similar to the control group, there is an indication that the patient is hypertensive. It is difficult to predict hypertension in patients, and it is possible that a patient could develop severe preeclampsia between visits to the antenatal clinics. Therefore, if the high‐frequency ultrasound scanner can pick up potential hypertensives early in pregnancy, these women could be identified as potentially high risk.
Proposal and evaluation of a Monte Carlo model for hair regrowth following plucking
Authors: Roersma M. E. , Veldhuis G. J.
Published: March 2003

Background/aims: The efficacy of single or multiple hair removal treatments reveals a number of properties of the hair follicle, such as the phase in the growing cycle and the hair growth speed. The aim of the present study was to provide a method to evaluate the results of hair removal treatments, in particular plucking, in order to obtain insight into some properties of the follicle and to propose a strategy for optimal treatment. Our hypothesis is that plucking of anagen hairs may result in either reset of the follicle to telogen, in mild damage to the follicle, resulting in a temporary reduction of the mitotic activity, or in an unaffected follicle, so that the hair continues to grow.

Methods: The regrowth of hairs after plucking was measured as a function of time for a number of subjects. Individual leg hairs within the areas observed were followed over time. Besides this, the growth speed of leg hairs was measured, and the extracted anagen hair length was determined to obtain an estimate of the anagen follicle depth on the leg. Monte Carlo simulations of the hair plucking and regrowth process were performed after the experiments. Some parameters derived from the experiments were used as inputs; others were fitted to achieve a good correlation between the result of the simulations and the experiments. Finally, the Monte Carlo routine was used to investigate the influence of the time interval between multiple plucking treatments.

Results: The regrowth of hairs after plucking, the growth speed and the extracted anagen hair length were measured. Both experiments and Monte Carlo simulations indicated that the result of plucking of an anagen hair is not limited to reset of the follicle to telogen or continued hair growth, but that a temporary reduction of the mitotic activity is very likely to occur. Finally, a linear relationship between the interval between epilation treatments and the average number of hairs on the skin was found using the Monte Carlo simulation.

Conclusions: The combination of experiments and Monte Carlo simulations is a very successful strategy for studying hair removal and hair (re)growth in detail.
Squamometry as a screening method for the evaluation of hydrating products
Authors: De Paepe Kristien , Janssens Kristel , Hachem Jean‐Pierre , Roseeuw Diane , Rogiers Vera
Published: March 2003

Background/aims: Squamometry is a combination of sampling corneocytes by adhesive coated discs followed by colour measurements after staining the cells. In this study, the correlation between stratum corneum (SC) hydration and scaling was investigated using capacitance measurements and squamometry, respectively.

Methods: Stratum corneum hydration and assessment of barrier function by transepidermal water loss (TEWL) measurements were carried out on different sites of left and right volar forearm skin of female volunteers (n=13; 24±3 years). D‐Squame® samples were taken on the same test spots.

Results: Visual evaluation of the coloured samples by light microscopy and the development of a four‐point‐scale scoring system was found to be necessary to detect and minimise overestimation of chroma C* values. Capacitance measurements revealed neither significant differences between corresponding sites on left and right forearms no between different skin areas on the same forearm. Squamometric measurements, on the contrary, did not show any symmetry between corresponding test sites on both forearms or between different sites on one forearm. No correlation could be found between squamometric measurements and SC hydration values obtained at the same test sites. No skin barrier function impairment lays at the origin of this observation since TEWL values were found to be similar at all test sites in comparison to control skin. In a randomised single blind study, hydration and TEWL showed a significant improvement of 25% and 15%, respectively, after a 14‐day application period of a moisturising cream. Although visual scoring of the coloured samples of both treated and untreated test spots revealed a good correlation with chroma C* values, the quantitative results found with squamometry were very doubtful.

Conclusion: Squamometry with visual scoring can be proposed as a screening technique for SC hydration rather than a quantitative method to appreciate skin moisturisation.
Changes of biophysical properties of the skin measured by non‐invasive techniques after Q‐switched Nd‐YAG laser therapy in patients with nevus of Ota
Authors: Duck Kim Sang , Kim Seok Woo , Huh Chang Hun , Suh Dae Hun , Eun Hee Chul
Published: March 2003

Background/aims: The aim of the study was to objectify the effect of a Q‐switched Nd‐YAG laser on Ota’s nevus in view of barrier function, surface contour changes, dermal blood flow, surface color changes and sebum production rate.

Methods: Fifteen Korean patients with nevus of Ota (between 14 and 54 years of age) were enrolled. All the patients were treated by Q‐switched Nd‐YAG laser and followed up for 12 weeks. A reflectance spectrophotometer, a colorimeter, laser Doppler flowmetry, a Tewameter, a Corneometer and a Sebumeter were used to make measurements.

Results: P values of less than 0.05 were regarded as statistically significant. In skin reflectance measurements, L* values declined for 4 weeks and increased at 12 weeks, indicating that the brightness of the lesions improved. a* values showed a significant increase at 2 and 4 weeks. On the contrary, b* values decreased at 2 weeks. Transepidermal water loss and dermal blood flux showed identical patterns, showing increases at 2 weeks. The water holding capacity decreased at 2 and 4 weeks, and thereafter showed a delayed recovery. Casual sebum production increased at 4, 8 and 12 weeks. The loss of skin roughness was observed at 4 weeks, recovering at 12 weeks, although statistically insignificant. Reflex spectrophotometry did not reflect the changing properties of the skin.

Conclusions: Our data suggest a useful model for evaluating physiologic skin changes after laser surgery in patients with nevus of Ota.
Quantification of erythema using digital camera and computer‐based colour image analysis: a multicentre study
Authors: Setaro Michele , Sparavigna Adele
Published: March 2003

Background/purpose Colour measurements obtained from digitized images have been proposed as a simple and cost‐effective way to evaluate skin colour and the activity of treatments. The main disadvantage of the method is the fact that it is highly dependent on ambient light: even if an accurate control of subjects' illumination is provided, readings remain not comparable among different laboratories. The purpose of this study was to develop a highly reproducible system for computerized colour image analysis of skin erythema, making it possible to compare readings from different environmental light conditions.

Patients and Methods Three hundred and forty‐eight Caucasian adult healthy subjects (age range: 18–60 years) of both sexes (14% males, 86% females), were enrolled in the study by 49 dermatologists distributed all over Italy. They were recruited among patients who required aesthetic treatments involving skin erythema, like chemical peeling and laser epilation. Once the treatment was administered, clinical evaluations and pictures were taken at the level of treated areas. Visual assessment of erythema was done on the basis of conventional clinical grades (0 = absent; 1 = slight; 2 = moderate; 3 = intense). The clinicians participating in the study were asked to put a standard colour marker (red, green and blue coloured self‐adhesive ring) in the photographed skin area. The difference between r, g, b values of photographed colour markers on the skin of single patients participating in the study and the r, g, b values obtained photographing the colour marker in fixed illumination conditions was used to adjust skin colour measurements. Then erythema index (E.I) on digitized images was calculated subtracting red value to green one by averaging procedure of different pixels.

Results Erythema index. average value among the groups divided according to the conventional clinical score increased progressively from score 0–2, while it decreased from score 2 to score 3. The differences in E.I. mean values among the score groups (0 vs. 1, 1 vs. 2, 2 vs. 3) were statistically significant (P < 0.05).

Conclusion We developed a method for the measurement of skin erythema using digital camera, normalized r, g, b colour co‐ordinate system and computerized calculation of E.I. Clinical usefulness of our method for absent, slight and moderate erythema, was demonstrated. For intense erythema lesions we did not find a correspondence between clinical and computerized evaluation, probably due to other factors involved in skin inflammation (e.g. oedema).
The dynamics of transepidermal water loss (TEWL) from hydrated skin
Authors: Gioia Francesco , Celleno Leonardo
Published: March 2003

Background/aims: When an occlusive cover is applied on the skin, the transepidermal water loss (TEWL) is inhibited and the skin moisturises. Upon the removal of the occlusion the water, which accumulated in the skin porosity during the occlusion, evaporates and diffuses outside showing a TEWL rate larger than the basal value, and function of time. The aim of this paper is to develop a physical–mathematical model for simulating the dynamics of Epidermal (free‐) Water Evaporation (EWE) and of transepidermal water loss of hydrated skin.

Methods/Results: The model, which is based on general results and methods of transport phenomena, has been calibrated and validated by experimental tests, in vivo, with the use of an evaporimeter. Both the theoretical model and the experimental results show that the release of excess water that accumulates in the skin following an occlusion, is a fast transient phenomenon, which has a characteristic time of the order of minutes (the initial decay is very rapid indeed, in less than a minute the TEWL value may decrease by more than 50%). On the other hand, the characteristic measuring time of the evaporimeter may be as large as 30 s. Therefore, as shown in the paper, the use of the evaporimeter for measuring the initial values of TEWL upon immediate removal of the occlusion is not reliable. When a transient phenomenon cannot be fully described by a measuring device that has an initial characteristic response time of the order of the characteristic time of the phenomenon, a mathematical model, which describes the dynamics of the phenomenon must be developed. Then the measurements taken after the measuring device is stabilised may be extrapolated to the initial times by the use of the model, thus allowing a full quantitative description of the phenomenon vs. time. Finally, the experimental results show that a baby's disposable diaper, when loaded with water, behaves like an impermeable occlusive cover on the skin.
A New Functional Domain of Guanine Nucleotide Dissociation Inhibitor (α‐GDI) Involved in Rab Recycling
Authors: Luan Peng , Heine Andreas , Zeng Ke , Moyer Bryan , Greasely Samantha E. , Kuhn Peter , Balch William E. , Wilson Ian A.
Published: March 2003

Guanine nucleotide dissociation inhibitor (GDI) is a 55‐kDa protein that functions in vesicular membrane transport to recycle Rab GTPases. We have now determined the crystal structure of bovine α‐GDI at ultra‐high resolution (1.04 Å). Refinement at this resolution highlighted a region with high mobility of its main‐chain residues. This corresponded to a surface loop in the primarily α‐helical domain II at the base of α‐GDI containing the previously uncharacterized sequence‐conserved region (SCR) 3A. Site‐directed mutagenesis showed that this mobile loop plays a crucial role in binding of GDI to membranes and extraction of membrane‐bound Rab. This domain, referred to as the mobile effector loop, in combination with Rab‐binding residues found in the multi‐sheet domain I at the apex of α‐GDI may provide flexibility for recycling of diverse Rab GTPases. We propose that conserved residues in domains I and II synergize to form the functional face of GDI, and that domain II mediates a critical step in Rab recycling during vesicle fusion.
The Molecular Mechanism of Transport of Macromolecules Through Nuclear Pore Complexes
Authors: Bayliss Richard , Corbett Anita H. , Stewart Murray
Published: March 2003

Trafficking of macromolecules between nuclear and cytoplasmic compartments takes place through the nuclear pore complexes (NPCs) of the nuclear envelope. Nuclear trafficking involves a complex series of interactions between cargo, soluble transport factors (carriers) and nuclear pore proteins (nucleoporins) that are orchestrated by the Ras‐family GTPase Ran. The primary role of Ran is probably to establish directionality and to sort molecules to be transported by controlling the interaction between carriers and cargoes, so that they bind in one compartment but dissociate in the other. Translocation of carriers and cargo‐carrier complexes through NPCs requires interactions between the carriers and nucleoporins that contain distinctive tandem sequence repeats based on cores rich in glycine and phenylalanine residues that are separated by hydrophilic linkers. Much recent work has focused on these interactions and, in particular, their specificity, regulation and function. Evidence is accumulating that carriers move through the NPC by distinct but overlapping routes using specific subsets of nucleoporins.
Phagocytosis and Macropinocytosis inDictyostelium: Phosphoinositide‐Based Processes, Biochemically Distinct
Authors: Cardelli James
Published: March 2003

Phagocytosis and macropinocytosis are actin‐dependent clathrin‐independent processes primarily performed by cells like neutrophils and macrophages that result in the internalization of particles or the formation of fluid‐filled macropinosomes, respectively. Phagocytosis consists of a number of stages, including attachment of particles to cell surface receptors, engulfment of the particle dependent on actin polymerization and membrane exocytosis, and formation of phago‐lysosomes. In contrast, the molecular steps regulating macropinocytosis are only just now being deciphered. Much remains to be learned concerning the signaling pathways that regulate these processes.Dictyosteliumis a genetically and biochemically tractable professional phagocyte that has proven to be a powerful system with which to determine the nature of the molecular steps involved in regulating these internalization processes. This review summarizes what is currently understood concerning the molecular mechanisms governing phagocytosis and macropinocytosis inDictyosteliumand describes recent data concerning the common and distinct pathways that regulate these processes.
Neurotoxic Traffic: Uncovering the Mechanics of Amyloid Production in Alzheimer's Disease
Authors: Huse Jason T. , Doms Robert W.
Published: March 2003

Alzheimer's disease (AD) is thought by many to result from the accumulation of the neurotoxic amyloid‐β (Aβ) peptide in brain parenchyma. The process by which Aβ is proteolytically derived from the larger amyloid precursor protein (APP) has been the focus of much attention in the AD research field over the past decade. Recently, several of the proteins directly involved in the generation of Aβ have been identified and characterized providing a number of viable therapeutic targets for the treatment of AD. However, the cellular mechanisms by which these proteins interact in the proteolytic processing of APP have not been well defined, nor are they readily apparent when one considers what is known about the intracellular localization and trafficking of the various participants. This article will review the underlying cell biology of Aβ production and discuss the mechanistic options for APP processing given the current knowledge of the proteases involved.
Clathrin Interactions with C‐Terminal Regions of the Yeast AP‐1 β and γ Subunits are Important for AP‐1 Association with Clathrin Coats
Authors: Yeung Bonny G. , Payne Gregory S.
Published: March 2003

Heterotetrameric adaptor (AP) complexes are thought to coordinate cargo recruitment and clathrin assembly during clathrin‐coated vesicle biogenesis. We have identified, and characterized the physiological significance of clathrin‐binding activities in the two large subunits of the AP‐1 complex in Saccharomyces cerevisiae. Using GST‐fusion chromatography, two clathrin‐binding sites were defined in the β1 subunit that match consensus clathrin‐binding sequences in other mammalian and yeast clathrin‐binding proteins. Clathrin interactions were also identified with the C‐terminal region of the γ subunit. When introduced into chromosomal genes, point mutations in the β1 clathrin‐binding motifs, or deletion of the γ C‐terminal region, reduced association of AP‐1 with clathrin in coimmunoprecipitation assays. The β1 mutations or the γ truncation individually produced minor effects on AP‐1 distribution by subcellular fractionation. However, when β1 and γ mutations were combined, severe defects were observed in AP‐1 association with membranes and incorporation into clathrin‐coated vesicles. The combination of subunit mutations accentuated growth and α‐factor pheromone maturation defects in chc1‐ts cells, though not to the extent caused by complete loss of AP‐1 activity. Our results suggest that both the β1 and γ subunits contribute interactions with clathrin that are important for stable assembly of AP‐1 complexes into clathrin coats in vivo.
A Glut4‐Vesicle Marker Protein, Insulin‐Responsive Aminopeptidase, is Localized in a Novel Vesicular Compartment in PC12 Cells
Authors: Thoidis Galini , Kandror Konstantin V.
Published: March 2003

Glut4‐containing vesicles represent a regulated recycling compartment in insulin‐sensitive fat and skeletal muscle cells, the nature and origin of which are not fully understood. In addition to Glut4 itself, these vesicles compartmentalize a number of proteins, at least one of which, insulin‐responsive aminopeptidase, or IRAP, is completely colocalized with Glut4 in insulin‐sensitive tissues. However, unlike Glut4, IRAP is expressed in a variety of other tissues and cell lines. Here, we explored the intracellular localization of IRAP in the rat pheochromocytoma cell line PC12. We found that this protein is present in a distinct population of slowly recycling light vesicles. By gradient centrifugations, immunoadsorption and double immunofluorescent staining, these vesicles are different from transferrin‐containing endosomes, small synaptic vesicles and secretory granules and may thus represent a novel compartment in PC12 cells. Glut4‐GFP chimera transiently expressed in PC12 cells is targeted to IRAP‐containing vesicles indicating that cotargeting of Glut4 and IRAP is not specific for adipocytes and myocytes, but is faithful in a foreign cell type. We suggest that PC12 cells may possess a novel type of a vesicular carrier that may represent the homolog of Glut4‐vesicles.
Proteolytic Function of GPI‐Anchored Plasma Membrane Protease Yps1p in the Yeast Vacuole and Golgi
Authors: Sievi Eeva , Suntio Taina , Makarow Marja
Published: March 2003

Yps1p is a member of the GPI‐anchored aspartic proteases which reside at the plasma membrane of Saccharomyces cerevisiae. Here we show that in Δerg6 cells, where a late biosynthetic step of the membrane lipid ergosterol is blocked, part of Yps1p was targeted to the vacuole. There it overtook proteolytic functions of the Pep4p protease, resulting in processing of pro‐CPY to CPY in cells lacking the PEP4 gene. Yps1p was enriched in membrane microdomains, as it could be isolated in detergent‐insoluble complexes from both normal and Δerg6 cells. Vacuolar Yps1 caused degradation of a mammalian sialyltransferase ectodomain fusion protein (ST6Ne), which was directed from the Golgi to the vacuole in both normal and Δerg6 cells. Unexpectedly, ST6Ne was degraded also when arrested in the Golgi in a temperature‐sensitive sec7–1 mutant. Newly synthesized Yps1p, in transit to the plasma membrane, was also involved in the Golgi‐associated degradation. These data show that GPI‐anchored proteases, whose biological roles are unknown, may reside and function in different subcellular locations.
The Protein Coat in Membrane Fusion: Lessons from Fission
Authors: Kozlov Michael M. , Chernomordik Leonid V.
Published: March 2003

Multiple cell biological processes involve two opposite rearrangements of membrane configuration, referred to as fusion and fission. While membrane intermediates in protein‐mediated fusion have been studied in some detail, the global force which drives sequential stages of the fusion reaction from early local intermediates to an expanding fusion pore remains unknown. Fusion proceeds via stages, which are analogous but in the opposite direction to that of membrane budding‐off and fission driven by protein coats. On the basis of this analogy, we propose that an interconnected coat formed by membrane‐bound activated fusion proteins surrounding the membrane contact zone generates the driving force for fusion. This fusion protein coat has a strongly curved intrinsic shape opposite to that of the protein coat driving fission. To relieve internal stresses, the fusion protein coat spontaneously bends out of the initial shape of the membrane surface. This bending produces elastic stresses in the underlying lipid bilayer and drives its fusion with the apposing membrane. The hypothesis that ‘bystander’ proteins (i.e. fusion proteins outside the contact zone) generate the driving force for fusion offers a new interpretation for a number of known features of the fusion reaction mediated by the prototype fusion protein, influenza hemagglutinin, and might bring new insights into mechanisms of other fusion reactions.
Objective Evaluation of Differences in Protein Subcellular Distribution
Authors: Roques Edward J. S. , Murphy Robert F.
Published: March 2003

Research on the cell and molecular biology of proteins involved in membrane traffic often requires determination of the effects of various experimental conditions on the subcellular distributions of those proteins. This is most often accomplished by acquiring fluorescence microscope images and visually comparing these images. While this approach is quite suitable for detecting major changes in distributions, it is not sensitive to small changes and does not permit a quantitative and objective analysis. We therefore describe the application of pattern analysis methods to the comparison of sets of fluorescence microscope images. This approach provides a high throughput and reproducible technique to determine whether image distributions differ within a specified statistical confidence, and is shown to resolve image sets indistinguishable by visual inspection.
Transfer of GRP94(Gp96)‐Associated Peptides onto Endosomal MHC Class I Molecules
Authors: Berwin B. , Rosser M. F. N. , Brinker K. G. , Nicchitta C. V.
Published: March 2003

GRP94 (gp96)‐associated peptides can elicit cellular immune responses, an activity thought to reflect the presence of a cell surface receptor (CD91) on antigen‐presenting cells that mediates GRP94 internalization and trafficking to an amenable site for peptide transfer to major histocompatibility complex class I molecules. We report that GRP94 internalized by receptor‐mediated endocytosis is trafficked to a Rab5a, CD1 and transferrin‐negative, Fc receptor and major histocompatibility complex class I‐positive endocytic compartment. Receptor‐internalized GRP94 did not access the endoplasmic reticulum of antigen‐presenting cells. To identify the site of re‐presentation of GRP94‐associated peptides, kinetic analyses were performed utilizing GRP94‐OVA (SIINFEKL) peptide complexes, with peptide re‐presentation assayed with the Kb‐SIINFEKL‐specific MAb, 25‐D1.16. Analyses of the kinetics of re‐presentation of GRP94‐associated peptides, under conditions in which de novo synthesis of major histocompatibility complex class I molecules was inhibited, identified a post‐endoplasmic reticulum compartment, accessed by mature major histocompatibility complex class I, as the predominant site of GRP94‐associated peptide exchange onto major histocompatibility complex class I.
Immunohistochemical study of oral lichen planus associated with hepatitis C virus infection, oral lichenoid contact sensitivity reaction and idiopathic oral lichen planus
Authors: Mega H , Jiang W‐W , Takagi M
Published: March 2003

OBJECTIVES: Oral lichen planus (OLP) is a common mucocutaneous disorder and might be associated to a possible pathogenic relationship with hepatitis C virus (HCV) infection or hypersensitivity to dental alloy. We examined the clinical and immunohistochemical features of OLP associated with HCV infection (OLP‐HCV), oral lichenoid contact sensitivity reaction (OLCSR), and idiopathic oral lichen planus (iOLP). The immunohistochemical expressions of CD4, CD8, B cells, Class II major histocompatibility complex antigen (HLA‐DR), S‐100, HSP60, Proliferating cell nuclear antigen (PCNA) and Ki‐67 were compared to study the pathogenic differences of the three OLP groups.

MATERIALS AND METHODS: Three groups of OLP patients, (1) OLP‐HCV patients (n=17), (2) OLCSR patients (n=10) and (3) iOLP patients (n=14) were retrieved from clinical records and tissues examined immunohistochemically by the avidin–biotin‐complex technique.

RESULTS: The patients with OLP‐HCV showed widespread lesions. The proportion of CD8+ cells was found to be significantly higher in the lamina propria of the OLP‐HCV patients and a significantly lower proportion of CD8+ cells of the OLCSR patients was noticed in the epithelium or the connective tissue papillae than in the iOLP patients. There were no significant differences in either the number of CD4+ cells or B cells between the three OLP groups. No significant differences in the number of HLA‐DR+ cells were found between the three OLP groups and some OLP‐HCV patients showed a significant increase of S‐100+ cells in the epithelium compared with iOLP patients. There were no significant differences in either the number of PCNA+ or Ki‐67+ cells between the groups. The patients showed similar weak expressions of HSP60 in the three OLP groups.

CONCLUSION: The different distributions of the CD8+ cells that could have functionally different roles might be related to the distinct pathogenic mechanisms in the three OLP groups.
Oral mucosal conditions in elderly dental patients
Authors: Jainkittivong A , Aneksuk V , Langlais RP
Published: March 2003

OBJECTIVES: The goals of this study were as follows: to obtain baseline information on the incidence of oral mucosal conditions in a population of elderly Thai patients and to investigate differences in the presentation of these findings in relation to age, sex and the wearing of dentures.

SUBJECTS AND METHODS: The incidence of oral mucosal conditions was determined by the clinical examination of a sample of 500 Thai patients aged 60 years and older.

RESULTS: The overall incidence of oral mucosal conditions was 83.6% with no significant difference between men (81.4%) and women (85%). The incidence of oral mucosal conditions indicated a significant increase with advancing age. Varices (59.6%), fissured tongue (28%) and traumatic ulcer (15.6%) were the three most common conditions; and the incidence increased with age. Leukoplakia and smoker's melanosis were more common in men whereas lichen planus was seen more frequently in women. Three cases of oral cancer were detected, representing an incidence of 0.6%. Denture wearers (62.7%) exhibited a significantly higher prevalence of oral mucosal conditions than subjects who had no dentures (28.5%) and subjects with crowns and/or bridges (8.8%). The three most common denture‐related problems were traumatic ulcer (22.6%), denture stomatitis (14.3%) and angular cheilitis (4.8%). In addition, the incidence of denture‐related conditions among complete denture wearers (46.3%) was higher than in those wearing partial dentures (40.8%).

CONCLUSION: The current results regarding an elderly Thai population support the studies of other populations whereby the incidence of oral mucosal conditions in the elderly is related to age, sex and the wearing of dentures.
Virtual endoscopic view of salivary gland ducts using MR sialography data from three dimension fast asymmetric spin‐echo (3D‐FASE) sequences: a preliminary study
Authors: Morimoto Y , Tanaka T , Yoshioka I , Masumi S , Yamashita M , Ohba T
Published: March 2003

OBJECTIVES: We performed magnetic resonance (MR) sialography of parotid gland and/or submandibular gland ducts using three‐dimensional fast asymmetric spin‐echo (3D‐FASE) sequencing. The objective was to make three‐dimensional (3D) reconstruction images and virtual endoscopic views of the parotid gland ducts using MR sialography data sets of 3D‐FASE sequences.

METHODS: We reviewed the MR sialography data sets with 3D‐FASE sequencing of 10 control volunteers and six patients. Three‐dimensional reconstruction images and virtual endoscopic views of the parotid gland and/or submandibular gland ducts were generated with maximum intensity projection (MIP), shaded surface display (SSD), and volume rendering techniques (VRT).

RESULTS: The main parotid gland and/or submandibular gland ducts, large branches within the glands, and small branches were fairly well defined in a very short acquisition time on MR sialographic images with 3D‐FASE sequencing in nine of the 10 healthy volunteers. The 3D‐reconstruction images of the parotid gland ducts and/or submandibular gland ducts showed the entire length of the branch paths and complete images from all angles, and the virtual endoscopic views showed the endoluminal tracts of the main ducts and the large branches in nine. In the patient with Sjogren's syndrome, chronic sialoadenitis, and salivary calculi in the Wharton ducts, the MR sialographic images showed diffuse areas of punctate high signal intensity, dilatation of Stensen's duct, or stones of Wharton's duct, respectively. Furthermore, the 3D‐reconstruction images of the salivary gland ducts showed the stenoses and stones in the branch paths and complete images from all angles, and the virtual endoscopic views showed the stenoses and stones in the endoluminal tracts of the main and large branches.

CONCLUSIONS: Our initial experience showed that virtual MR endoscopy could be performed to observe the endoluminal tracts of parotid and submandibular glands. The clinical use of the virtual MR endoscopy for salivary gland ducts has not been established yet. Future applications of the 3D‐reconstruction images and virtual endoscopic views using MR sialography data sets of 3D‐FASE sequences are very attractive and further expansion of this field is expected.
Molecular analysis for genetic counselling in amelogenesis imperfecta
Authors: Aldred MJ , Hall RK , Kilpatrick N , Bankier A , Savarirayan R , Lamandé SR , Lench NJ , Crawford PJM
Published: March 2003

OBJECTIVE: To use molecular genetics to establish themode of inheritance in a family with amelogenesis imperfecta.

MATERIALS AND METHODS: The polymerase chain reaction was used to amplify exons of the amelogenin gene on the short arm of the X chromosome.

RESULTS: A single base deletion mutation in exon 6 of the amelogenin gene was identified. This mutation was a single base deletion of a cytosine residue – 431delC – in codon 96 of exon 6, introducing a stop codon 30 codons downstream of the mutation in codon 126 of the exon.

CONCLUSION: The firm establishment of an X‐linked mode of inheritance affects the genetic counselling for this family.
Oral lichen planus and hepatitis C virus infection
Authors: Figueiredo LC , Carrilho FJ , De Andrade HF , Migliari DA
Published: March 2003

OBJECTIVE: This investigation was conducted to determine the possible association between oral lichen planus (OLP) and hepatitis C virus infection (HCV) in the population of São Paulo (Brazil).

MATERIALS AND METHODS: Three groups of patients were studied: group 1 was composed of 68 patients with OLP lesions; group 2 had 126 patients with HCV infection; and the control group consisted of 898 individuals seeking dental treatment at our school, used to determine the prevalence of lichen planus in the general population. The prevalence of HCV in group 1 was determined and compared with that of the population of São Paulo (Focaccia et al (1998) Brazilian J Infec Dis 2: 269), while the prevalence of OLP in group 2 was determined and compared with that of the control group.

RESULTS: The results showed that the frequency of HCV in OLP patients was 8.8%, significantly higher than in the general population of São Paulo, which is 1.4% (P=0.002), and the frequency of OLP in HCV patients (4.7%) was also significantly higher (P=0.0003) than that of the control group (0.6%).

CONCLUSION: These data suggest that, at least in São Paulo, there is an association between OLP and HCV infection.
Can we successfully maintain risk patients?
Authors: Darby M.
Published: March 2003

Abstract:  The most fundamental premise in the current view of periodontal disease is that not all individuals are at equal risk for disease and disease progression. Studies reveal that about 5–20% of the population is at risk for severe disease progression. The purpose of this paper is to define at‐risk patients, review risk factors and indicators of disease progression, and outline an evidence‐based strategy that includes both self‐care and professional care for maintaining periodontal health. Risk factors/risk indicators considered include history of previous disease, increased pocket depth and loss of clinical attachment, frequency of dental care, specific bacterial pathogens, and systemic/environmental host factors such as smoking, diabetes mellitus, genetics, and stress. Because host factors may have more influence on disease progression than periodontal pathogens, personal and professional maintenance care must include the role of the host in periodontal disease progression. By examining the evidence surrounding these complex issues, dentists and dental hygienists are able to determine the extent to which evidence supports available approaches to maintain periodontal health and control disease progression.
HRT, women and heart disease: facts about prevention
Authors: Goldie Maria Perno
Published: March 2003

Abstract:  In 1996, the U.S. Preventive Services Task Force (USPSTF) recommended counseling all perimenopausal and postmenopausal women about the potential benefits and harms of HRT. They determined that there was insufficient evidence to recommend for or against HRT for all women, but thought that individual decisions should be based on patient risk factors, an understanding of the probable benefits (for example, the prevention of myocardial infraction or fracture) and harms (for example, endometrial cancer with unopposed estrogen or breast cancer), and personal preferences. New recommendations were posted on October 23, 2002, and now the USPSTF recommends against the routine use of estrogen and progestin for the prevention of chronic conditions in postmenopausal women. The USPSTF found fair to good evidence that the combination of estrogen and progestin has both benefits and harms.
Immunolesion of Hindbrain Catecholaminergic Projections to the Medial Hypothalamus Attenuates Penile Reflexive Erections and Alters Hypothalamic Peptide mRNA
Authors: Fraley G. S.
Published: March 2003

The central mechanisms underlying diabetes‐associated impotence are currently unknown. This study utilized immunolesion techniques to eliminate hindbrain catecholaminergic projections to the medial hypothalamus which have been reported to be glucoresponsive. The immunolesioned male rats had an attenuated feeding response to glucoprivic challenge. Furthermore, these lesioned rats had significantly attenuated penile reflexes. Northern blot analyses of hypothalamic oxytocin mRNA expression showed a significant increase; however, neuropeptide Y mRNA expression did not. These results suggest that hindbrain catecholaminergic neurones may alter the expression of hypothalamic neuropeptides that stimulate penile erections based upon glucoregulatory signals from the periphery.
Redefining Gonadotropin‐Releasing Hormone (GnRH) Cell Groups in the Male Syrian Hamster: Testosterone Regulates GnRH mRNA in the Tenia Tecta
Authors: Richardson Heather N. , Parfitt David B. , Thompson Robert C. , Sisk Cheryl L.
Published: March 2003

Gonadotropin‐releasing hormone (GnRH) regulates the production of testosterone via the hypothalamic‐pituitary‐gonadal axis and testosterone, in turn, regulates the GnRH system via negative feedback. We compared testosterone regulation of GnRH mRNA expression in four anatomically defined GnRH cell groups in juvenile and adult male Syrian hamsters, including a rostral population of GnRH cells in the tenia tecta. In situ hybridization histochemistry (ISHH) was used to measure GnRH mRNA in brains from castrated juveniles and adults treated with 0 mg or 2.5 mg testosterone pellets for one week. ISHH was performed on coronal sections using a 35S‐cRNA probe generated from Syrian hamster GnRH cDNA. Testosterone treatment resulted in a significant reduction in mean area of GnRH neurones covered by silver grains within the tenia tecta, but only a trend toward decreased GnRH mRNA in the diagonal band of Broca/organum vasculosum of the lamina terminalis (DBB/OVLT), medial septum (MS), and caudal preoptic area (cPOA). The effects of testosterone were independent of age. Frequency distribution analyses unveiled a significant reduction in the number of heavily labelled cells following testosterone treatment within the tenia tecta and MS. Simple regression analyses revealed a significant positive correlation between plasma luteinizing hormone concentrations and GnRH mRNA only in the tenia tecta. These data indicate that, overall, GnRH mRNA is modestly reduced by testosterone, and the most robust attenuation of GnRH mRNA occurs within the tenia tecta. This is the first report to link mechanisms of steroid negative feedback with tenia tecta GnRH neurones, providing a new focus for investigating brain region‐specific steroidal regulation of GnRH synthesis.