bluuebunny/crossref_metadata_2025 huggingface dataset:
Physiological concentrations of melatonin inhibit the nitridergic pathway in the Syrian hamster retina
Authors: Sáenz Daniel A. , Turjanski Adrián G. , Sacca Geraldine B. , Marti Marcelo , Doctorovich Fabio , Sarmiento María I. Keller , Estrin Darío A. , Rosenstein Ruth E.
Published: March 2003

In the present work, the effect of melatonin on the hamster retinal nitridergic pathway was examined. When the retinas were incubated in the presence of low concentrations (1 pM–10 nM) of melatonin for 15 min, a significant decrease of nitric oxide synthase (NOS) activity was observed. However, when crude retinal homogenates were preincubated with melatonin for 15 min, no changes in NOS activity were detected, despite the fact that under the same conditions trifluoperazine, a calmodulin inhibitor, significantly decreased enzymatic activity. Kinetic analysis showed that melatonin decreased the Vmax of retinal NOS without changes in the Km. On the other hand, low concentrations (100 pM) of melatonin significantly reduced retinal L‐arginine influx. A decrease in the Vmax of L‐arginine uptake was observed in the presence of melatonin, whereas the Km remained unchanged. Melatonin significantly inhibited the accumulation of cyclic guanosine monophosphate (cGMP) levels induced by both L‐arginine and sodium nitroprusside (SNP). In summary, the present results indicate that melatonin could be a potent inhibitor of the retinal nitridergic pathway.
Role of exogenous melatonin in reducing the nephrotoxic effect of daunorubicin and doxorubicin in the rat
Authors: Dzięgiel Piotr , Suder Elżbieta , Surowiak Paweł , Jethon Zbigniew , Rabczyński Jerzy , Januszewska Lidia , Sopel Mirosław , Zabel Maciej
Published: March 2003

Abstract:  The aim of these studies was to examine the nephroprotective effect of melatonin following the anthracycline administration [daunorubicin (DNR); doxorubicin (DOX)] in rats. Application of these drugs in chemotherapy is limited because of their cardiotoxicity and nephrotoxicity. Rats of the Buffalo strain were divided into groups according to the cytostatic drug used, its dose and sequence of administration [DNR or DOX single (i.v.) dose of 10 mg/kg b.w., i.e. acute intoxication and 3 mg/kg b.w. (i.v.) weekly for 3 wk, subchronic intoxication]. Melatonin was administered subcutaneously before and after every injection of a cytostatic drug at a dose of 10 mg/kg b.w. The severity of renal alterations was examined both biochemically [levels of lipid peroxidation markers, malonyldialdehyde (MDA) and 4‐hydroxyalkenals (4‐HDA)], or histologically. A statistically significant decrease in renal damage was noted after melatonin administration to acutely or subchronically intoxicated DNR‐treated and DOX‐treated rats. Biochemical assays revealed significant decreases in MDA and 4‐HDA levels following application of melatonin during subchronic DNR or DOX intoxication. In summary, melatonin was found to exert a protective effect on the kidney, which was particularly evident after subchronic DOX and DNR intoxication, using both histological or biochemical methods.
Melatonin attenuates MPTP‐induced dopaminergic neuronal injury associated with scavenging hydroxyl radical
Authors: Li Xue‐June , Gu Jing , Lu Shi‐Duo , Sun Feng‐Yan
Published: March 2003

To clarify the relationship between melatonin's hydroxyl radical (·OH) scavenging ability and its protective effect in 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced neuronal injury, in the present study, the salicylate trapping method combined with high‐performance liquid chromatography (HPLC)‐electrochemical detection were used to measure the contents of dihydroxybenzoic acid (DHBA) and dopamine (DA) in brain tissues of C57BL/6 mice. Immunocytohistochemistry was used to detect tyrosine hydroxylase (TH)‐like positive staining neurons. Results show that MPTP treatment induced an increase in the content of DHBA and decrease in the level of DA as well as the number of TH positive stained neurons in the mouse brain. However, melatonin dose‐dependently inhibited the increase of DHBA levels in ventral midbrain tissues, the decrease of DA content and the loss of dopaminergic neurons. Moreover, the relationship between the changes of DHBA and DA levels in the brain of mice following MPTP and melatonin treatment showed a statistically significant negative correlation. Present results suggest that melatonin can ameliorate MPTP‐induced dopaminergic neuronal lesions probably, at least partially, because of its inhibition of ·OH generation.
Melatonin attenuates kainic acid‐induced hippocampal neurodegeneration and oxidative stress through microglial inhibition
Authors: Chung Seung‐Yun , Han Seol‐Heui
Published: March 2003

Abstract: The antioxidant and anti‐inflammatory effects of melatonin on kainic acid (KA)‐induced neurodegeneration in the hippocampus were evaluated in vivo. It has been suggested that the pineal secretory product, melatonin, protects neurons in vitro from excitotoxicity mediated by kainate‐sensitive glutamate receptors, and from oxidative stress‐induced DNA damage and apoptosis. In this study, we injected 10 mg/kg kainate intraperitoneally (i.p.) into adult male Sprague‐Dawley rats. This results in selective neuronal degeneration accompanied by intense microglial activation and triggers DNA damage in the hippocampus. We tested the in vivo efficacy of melatonin in preventing KA‐induced neurodegeneration, oxidative stress and neuroinflammation in the hippocampus. Melatonin (2.5 mg/kg, i.p.) was given 20 min before, immediately after, and 1 and 2 hr after KA administration. Rats were killed 72 hr later and their hippocampi were examined for evidence of DNA damage (in situ dUTP end‐labeling, i.e. TUNEL staining), cell viability (hematoxylin and eosin staining), and microglial (isolectin‐B4 histochemistry) and astroglial responses (glial fibrillary acidic protein immunohistochemistry), as well as lipid peroxidation (4‐hydroxynonenal immunohistochemistry). A cumulative dose of 10 mg/kg melatonin attenuates KA‐induced neuronal death, lipid peroxidation, and microglial activation, and reduces the number of DNA breaks. A possible mechanism for melatonin‐mediated neuroprotection involves its antioxidant and anti‐inflammatory actions. The present data suggest that melatonin is potentially useful in the treatment of acute brain pathologies associated with oxidative stress‐induced neuronal damage such as epilepsy, stroke, and traumatic brain injury.
Comparison between in‐line and rollerskating injury
Authors: Houshian S. , Andersen H. M.
Published: March 2003

Rollerskating is an activity that has become increasingly popular over the past several years among children and adults in Denmark. During a 7‐month period in 1997, 300 in‐line skaters and 107 roller skaters were treated in the Emergency Department, Esbjerg County Hospital. Of these, 60.4% had minor injuries (sprains, bruises, lacerations) and 39.6% fractures. There was no statistical significant difference in the types of injury between skater groups. The most common serious injury was fracture of the wrist, which occurred in both skater groups (25%, n=102). Almost all of the fractures of the wrist and elbow occurred among skaters who did not wear wrist or elbow guards. Only 20% of the skaters used protective equipment. In‐line skaters used protective equipment more often than did roller skaters. Of all accidents, 69% occurred on public roads (street and sidewalk).
Pre‐ and post‐season heart rate variability in adolescent cross‐country skiers
Authors: Hedelin R. , Wiklund U. , Bjerle P. , Henriksson‐Larsén K.
Published: March 2003

To investigate the effects on cardiac autonomic control after a competitive cross‐country skiing season, 9 females and 8 males, 16–19 years old, performed tilt‐table heart rate variability (HRV) recordings and incremental treadmill tests before (August), and after (April the following year) the most intensive period of training and competition. Spectral analysis of HRV showed increased total variability at rest and reduced low frequency variability in the tilted position (LFtilt) at the second test (P<0.05). The female subgroup showed consistently higher high frequency (HF) and total heart rate variability than males. Total run time (RunT) increased from 18.5±1.9 min to 19.4±1.7 min (mean±SD) in the entire group (P<0.05), while VO2max only showed a non‐significant increase (0.05<P<0.10). Submaximal heart rates (HRsubm) were reduced by an average of 4 beats (P<0.01) but maximal HR was unchanged. Performance data suggest a positive training effect. Following training, the increased total HRV, the reduced LFtilt (both at rest), and the lower submaximal heart rates indicate an altered control of heart rate both at rest and during exercise. The consistently higher HF and total variability in the females indicate an increased parasympathetic activity in females compared with males.
Serum concentrations of collagen degrading enzymes and their inhibitors after downhill running
Authors: Koskinen S. O. A. , Höyhtyä M. , Turpeenniemi‐Hujanen T. , Martikkala V. , Mäkinen T. T. , Oksa J. , Rintamäki H. , Löfberg M. , Somer H. , Takala T. E. S.
Published: March 2003

In the present study the release of proteins degrading extracellular matrix compounds to circulation was measured after damaging exercise in humans. Muscle damage was induced by downhill running; furthermore, the exercise was performed at both cold temperature (5 °C) and room temperature (22 °C) to study also the possible effect of environmental temperature on serum concentrations of matrix metalloproteinases MMP‐2 and MMP‐9, tissue inhibitors of metalloproteinases TIMP‐1 and TIMP‐2, and MMP‐2/TIMP‐2 complex, and muscle damage monitored by serum creatine kinase measurements. Results were compared with those obtained from patients having rhabdomyolysis, myositis and Becker muscular dystrophy. The present study demonstrates an acute increase in serum concentrations of MMP‐9, TIMP‐1, and MMP‐2/TIMP‐2 complex, but no changes in serum MMP‐2 concentrations in response to eccentric exercise. Serum creatine kinase activity data suggest greater muscle damage after downhill running in a cold environment than at room temperature. The present observations about at most slight changes in serum MMP and TIMP concentrations and lack of their correlation to increased serum creatine kinase after exercise indicate that serum measurements of MMPs and TIMPs do not sensitively respond to exercise induced skeletal muscle damage and extracellular matrix regeneration. On the other hand, severe skeletal muscle damage, such as rhabdomyolysis, myositis and Becker muscular dystrophy, seemed to have an effect on serum MMP and TIMP concentrations.
The correlation between peak oxygen uptake (VO2peak) and running performance in children and adolescents. Aspects of different units
Authors: Pettersen S. A. , Fredriksen P. M. , Ingjer F.
Published: March 2003

The method of removing the confounding effect of body mass on peak oxygen uptake simply by dividing the measured values by body mass has been questioned. The aim of the study was to find an expression of body mass for compensating for differences in body mass so as to achieve the best correlation to running performance. In a cross‐sectional study, design peak oxygen uptake (VO2peak) was measured in 107 boys in the age range 8–17 years and 88 girls in the age range 8–16 years. The present study indicates that VO2peak do not increase in proportion to body mass during running, rather that VO2peak is inversely related to body mass. When using allometric regression standards with the sexes separated in gender groups, there was a tendency that boys achieved scaling factors closer to unity than did the girls. The increase in subcutaneous fat in the girls throughout the pubertal years is the most likely reason why body mass increased proportionally more than VO2peak in girls. The present study indicates that VO2peak when expressed as milliliters per kilogram per minute (ml kg−1 min−1) is a poor denominator for VO2peak as a function of running performance in children and adolescents.
Immune function in Swedish élite orienteers
Authors: Lannergård A. , Fohlman J. , Wesslén L. , Rolf C. , Friman G.
Published: March 2003

During 1979–1992 an increased frequency of sudden unexpected cardiac death (SUD) occurred among young male Swedish élite orienteers. Subacute‐to‐chronic myocarditis was found in 12/16 (75%) at autopsy and Chlamydia pneumoniae, or a cross‐reacting agent, was suspected on the basis of diagnostic tests performed. Because myocarditis is an infrequent cause of SUD and clusters of SUD are rare, whereas Chlamydia pneumoniae infections are ubiquitous and seldom cause severe myocarditis, 119 top ranked élite orienteers (67 males and 52 females) and 36 highly trained male middle‐distance runners and cross‐country skiers, serving as controls, underwent immunologic screening in an effort to reveal possible immune dysfunction. Except for two orienteers and one runner/skier who showed genetic C3‐deficiency or IgA‐deficiency, the results showed no significant differences between the orienteers and controls with respect to immunoglobulin levels, complement activation, lymphocyte subsets, including activated T lymphocytes, and sIL‐2r‐α. IL‐1β, IL‐6, TNF‐α, and sCD8, tested in the orienteers only, were normal. However, IFN‐γ was significantly higher in controls than in orienteers, who showed normal levels, whereas the orienteers had increased sELAM‐1 and sICAM‐1 levels. Finally, sIL‐2 receptor‐α was similarly elevated in orienteers and controls. We conclude that, with the tests employed, no immunologic disturbance could be revealed in the orienteers that may potentially have increased their susceptibility to myocarditis and SUD.
Iontophoresis with cortisone in the treatment of lateral epicondylalgia (tennis elbow)—a double‐blind study
Authors: Runeson L. , Haker E.
Published: March 2003

Lateral epicondylalgia (tennis elbow) is a common dysfunction of the arm. Because there is no agreement concerning the pathophysiology, several modes of treatments have been tried and one of the most common is local steroid injection. Iontophoresis using corticosteroids is a fairly new method recommended in the treatment of lateral epicondylalgia and has become popular owing to impression of superiority compared to local injections—noninvasive, painless and nontraumatic. The aim of this double‐blind prospective, randomized study was to evaluate the short‐ and the long‐term pain‐relieving effect of corticosteroid iontophoresis in lateral epicondylalgia. Sixty‐four patients suffering from lateral epicondylalgia were consecutively randomized into two groups for corticosteroid or placebo iontophoresis. The patients were treated four times during 2 weeks. Follow‐ups were done the day after the final treatment and after 3 and 6 months. Twenty‐three patients dropped out before the 3‐month follow‐up because they wanted to complement the treatment or replace it with other treatments. No significant difference between the corticosteroid group and the placebo group in relation to subjective and objective outcome could be observed after the treatment period or at the follow‐ups. In fact, both groups improved throughout the study. The results of the present study do not support the use of corticosteroid iontophoresis in lateral epicondylalgia.
Hand and forearm skin: comparison of their respective responsiveness to surfactants*
Authors: Paye M. , Cartiaux Y. , Goffin V. , Pierard G. E.
Published: March 2003

Background/aims: Skin compatibility of detergent products is usually evaluated using predictive tests where products are applied on the back or the forearm of the volunteers, even if those products come more readily into contact with consumers’ hands. The current study aimed at comparing the skin responsiveness of hands and volar and dorsal forearms to a surfactant solution.

Method: Volunteers soaked simultaneously their forearms and hands in a solution of anionic surfactants, at 40 °C for 20 min, thrice a day and for 2 consecutive days. Skin condition on the hands, and the volar and dorsal forearms was evaluated by clinical examination and instrumental measurements.

Results: Significant differences were observed at baseline for various skin parameters, especially those related to skin dryness. After repetitive contacts with the surfactant solution, a parallel evolution of most skin parameters was observed – i.e., an absence of change in instrumentally measured erythema and transepidermal water loss, a similar decrease in corneometry values, and a similar increase in staining of the stratum corneum strippings and in clinical dryness. However, an opposite effect of the soakings on the cohesiveness between corneocytes harvested by tape strippings from hand and forearm was observed.

Conclusion: For most parameters, skin responsiveness to surfactants appears to be quite similar on the hands and forearms. It is inferred that forearms can be conveniently used to predict interaction of surfactants with hands.
Biomechanical measurements in microscopically thin stratum corneum using acoustics
Authors: Gardner T. N. , Briggs G. A. D.
Published: March 2003

Background/aims: This study investigated whether a scanning acoustic microscope (SAM) could be developed to measure changes in the mechanical properties of the microscopically thin external layer of skin, the stratum corneum. The adapted microscope was used to determine the effects of various aqueous reagents, as compared with water, on the thickness, density, compression wave velocity and elastic constant, using 10 μm thin sections of human skin.

Methods: Specimens were exposed to aqueous solutions of glycerol, sodium chloride and alpha‐hydroxy caprylic acid (HCA) to investigate permeation and to investigate the effect of these solutions on the above physical properties for signal transmission at a centre frequency of approximately 650 MHz in a path parallel to the epidermal layers.

Results: The system of measurement was found to give repeatable results and to provide a reliable indicator of the change in mechanical properties of the stratum corneum that arise from imbibition with different substances. Acoustic measurements of untreated specimen thickness and density agreed well with optical measurements and with previously published measurements, respectively. The trend in change of elastic moduli, however, was not in agreement with the results of the large‐scale extensibility tests of Takahashi et al. and Hall & Hill, which used thicker specimens that contained additional epidermal or dermal layers.

Conclusion: Disparate trends in elastic moduli were believed to be due to the strain rate dependence of the tissues and the different rates of loading applied during testing.
Utilization of a high‐resolution digital imaging system for the objective and quantitative assessment of hyperpigmented spots on the face
Authors: Miyamoto Kukizo , Takiwaki Hirotsugu , Hillebrand Greg G. , Arase Seiji
Published: March 2003

Background/aims:  The aim of this study was to quantify and confirm the efficacy of cosmetic formulations for hyperpigmented spots over a wide area of the face using a high quality digital imaging system that we developed.

Methods:  A total of 120 Japanese female volunteers aged 25–60 years with solar lentigines were treated for 6 months with a skin lightening moisturizer (SLM, thereafter) containing 3% magnesium ascorbyl phosphate on one side of the face and vehicle on the other side. During the course of the study, facial images were collected by the image analysis to measure facial skin colour and the total area of hyperpigmented spots. The evaluation was also conducted by visual grading. Measurements were made before and 1, 3, and 6 months after starting the application, and again 6 months after discontinuing the treatment. Three similar clinical studies using the same protocol were repeated for up to one‐month to confirm the reproducibility of the results and to examine seasonal variation.

Results:  SLM significantly reduced the total area of hyperpigmented spots (P < 0.005) after one month of treatment compared to the vehicle, with no significant variation in facial skin colour tone in the areas outside the hyperpigmented spots. The results of the visual grading were consistent with those obtained by image analysis. The total area of hyperpigmented spots 6 months after discontinuing the treatment had returned to pre‐treatment levels. The reproducibility of these clinical results was demonstrated in three follow‐up studies.

Conclusions:  A high‐resolution digital imaging method, combined with a split‐face clinical protocol is sensitive enough to prove that SLM readily reduces hyperpigmented spots, while maintaining normal facial skin colour.
Skin reflectance‐spectra and colour‐value dependency on measuring‐head aperture area in ordinary reflectance spectrophotometry and tristimulus colourimetry
Authors: Takiwaki H. , Miyaoka Y. , Skrebova N. , Kohno H. , Arase S.
Published: March 2003

Background/aims:  Measurement of skin colour has become increasingly popular in the study of dermatology with the increased availability of portable instruments. However, different instruments have been reported as giving different results from measurement of the same skin region. The aim of this study was to examine the effects of differences in measuring‐head aperture area on skin reflectance spectra and colour values.

Methods:  We measured both reflectance spectra and CIE‐L*a*b* values of the skin in five different anatomical regions on 10 subjects using two MINOLTA reflectance spectrometers that were identical apart from the aperture area of the measuring heads (diameters: 5 and 11 mm). For comparison, data were also obtained from a skin‐coloured tile.

Results:  Skin reflectance values measured with the wider‐aperture instrument were higher than those measured with the other, irrespective of anatomical location. The differences between the two were near zero at an incident light wavelength of 400 nm, but increased to around 10% of the reflectance value at 700 nm, increasing exponentially with incident light of increasing wavelength. Skin colour was observed to be brighter, redder and yellower, in CIE‐L*a*b* expression, when measured with the wider‐aperture instrument. The differences between measurements obtained from the skin‐coloured tile were much smaller.

Conclusion:  Skin reflectance and colour values measured with reflectance instruments are not absolute data but depend on the aperture area of the measuring head. This is probably due to variations in the proportion of longer‐wavelength light reflected from the skin and collected by the instrument.
Epidermal calcium release (ECR) in vivo sampled with a simple washout chamber technique
Authors: Said Lilian , Serup Jørgen , Rebel Carl
Published: March 2003

Background/aims: Epidermis forms the protective barrier of the skin by its outermost layer, stratum corneum. The purpose of this study was to investigate the epidermal barrier in view of epidermal calcium release (ECR), phosphate release, transepidermal water loss (TEWL) and skin surface pH. Calcium is mainly an intracellular ion. Calcium was sampled introducing a new and simple washout chamber technique for the study of epidermal release in vivo.

Methods: Test sites on forearms of 13 healthy subjects were pre‐treated with 24 h water occlusion, 24 h 2% sodium lauryl sulphate (SLS) or tape stripped. Both untreated and pre‐treated test sites were exposed to a water washout chamber with 200µ deionized water as a solvent. Water washout chambers were removed after two hours and calcium and phosphate in the water was analyzed. Transepidermal water loss and pH were measured before and after the trial.

Results: pH increased after tape stripping and after exposure to SLS. Transepidermal water loss increased significantly at all test sites. Calcium was significantly released from SLS‐treated sites but not from tape stripped sites. There was generally a correlation between ECR, phosphate release, TEWL and pH. In this study ECR is showed to be a barrier marker of high reproducibility.

Conclusions: Epidermal calcium release or ECR is found useful as an indicator of skin barrier function. Calcium release and increase of pH appear mainly to illustrate direct and corrosive damage to epidermal cells and functions contrasting TEWL, in this experiment probably reflecting intercellular damage of fracturing as exemplified by mechanical damage resulting from surface stripping. This new distinction of skin barrier damage into cellular damage resulting from a corrosive chemical trauma and intercellular damage and fracturing resulting from a mechanical trauma is exemplified in SLS provocative testing and tape stripping, the former characterized by increased ECR. The washout chamber technique was deemed technically reliable and reproducible, and has a major potential in experimental dermatology and skin pharmacology for the study of in vivo epidermal release of a range of endogenous and exogenous substances.
Motors, Clutches and Brakes for Membrane Traffic: A Commemorative Review in Honor of Thomas Kreis
Authors: Schroer Trina A.
Published: March 2003

Membranous organelles interact with a wide variety of cytoskeletal proteins that allow them to be organized into dynamic, yet stable, structures with distinct subcellular addresses. This review provides an up‐to‐date summary of the motor enzymes and membrane‐microtubule crosslinking proteins that have been implicated in this process, and discusses the potential impact membrane anchoring may have on cellular architecture.
Complete Reconstitution of Clathrin Basket Formation with Recombinant Protein Fragments: Adaptor Control of Clathrin Self‐Assembly
Authors: Greene Barrie , Liu Shu‐Hui , Wilde Andrew , Brodsky Frances M.
Published: March 2003

Clathrin polymerization into a polyhedral basket, surrounding budding membrane vesicles, mediates protein sorting during endocytosis and organelle biogenesis. Adaptor proteins target clathrin assembly to specific membrane sites and sequester receptors into the clathrin coat. We have reconstituted complete clathrin basket formation from recombinantly expressed fragments of clathrin and adaptors. This reconstitution reveals a hierarchy of clathrin self‐assembly interactions and demonstrates that adaptors control basket formation by alignment of the distal domains of the clathrin triskelion leg through their binding to the terminal domain.
Lipid Traffic: The ABC of Transbilayer Movement
Authors: Raggers René J. , Pomorski Thomas , Holthuis Joost C.M. , Kälin Nanette , van Meer Gerrit
Published: March 2003

Membrane lipids do not spontaneously exchange between the two leaflets of lipid bilayers because the polar headgroups cannot cross the hydrophobic membrane interior. Cellular membranes, notably eukaryotic plasma membranes, are equipped with special proteins that actively translocate lipids from one leaflet to the other. In addition, cellular membranes contain proteins that facilitate a passive equilibration of lipids between the two membrane halves. In recent years, a growing number of proteins have been put forward as lipid translocators or facilitators. Unexpectedly, some of these appear to be required for efficient translocation of lipids lacking bulky headgroups, like cholesterol and fatty acids. The candidate lipid translocators identified so far belong to large protein families whose other members include pumps for amphiphilic molecules like bile salts and drugs.
Pumping iron: the strange partnership of the hemochromatosis protein, a class I MHC homolog, with the transferrin receptor
Authors: Enns Caroline A.
Published: March 2003

People suffering from hereditary hemochromatosis (HH) can not regulate the uptake of iron properly and gradually accumulate iron in their body over their lifetime. The protein involved in HH, HFE, has been recently identified as a class I major histocompatibility complex (MHC) homolog. The wild‐type HFE associates and co‐traffics with the transferrin receptor (TfR). The mutation responsible for 83% of HH (C260Y) results in the failure of HFE to form a critical disulfide bond, bind β2 microglobulin, bind TfR, and traffic to the cell surface. In non‐polarized cells, the partnership of HFE and TfR results in decreased iron uptake into cells. The mechanism whereby a class I MHC homolog modifies the function of a membrane receptor and how this dynamic complex of molecules regulates iron transport across intestinal epithelial cells is the subject of this review.
The Unfolded Protein Response: No Longer Just a Special Teams Player
Authors: Spear Eric , Ng Davis T.W.
Published: March 2003

The endoplasmic reticulum stress pathway known as the unfolded protein response is currently the best understood model of interorganellar signal transduction. Bridging a physical separation, the pathway provides a direct line of communication between the endoplasmic reticulum lumen and the nucleus. With the unfolded protein response, the cell has the means to monitor and respond to the changing needs of the endoplasmic reticulum. Beginning with the discovery of its remarkable signaling mechanism in yeast, the unfolded protein response has not ceased to reveal more of its many secrets. By applying powerful biochemical, genetic, genomic, and cytological approaches, the recent efforts of many groups have buried the long‐held notion that the unfolded protein response is simply a regulatory platform for endoplasmic reticulum chaperones. We now know that the unfolded protein response regulates many genes that affect diverse aspects of cellular physiology. In addition, studies in mammals have revealed novel unfolded protein response signaling factors that may contribute to the specialized needs of multicellular organisms. This article focuses on these and other recent developments in the field.
Applying Multiphoton Imaging to the Study of Membrane Dynamics in Living Cells
Authors: White John G. , Squirrell Jayne M. , Eliceiri Kevin W.
Published: March 2003

The endomembrane system of a cell is a highly dynamic, ephemeral structure that is difficult to visualize. Reconstructions from sections of fixed material can provide high‐resolution information on intercellular membrane architecture, but such techniques are fraught with artifacts and are of little help in understanding the dynamics of intracellular membrane traffic. Recently, the availability of fluorescent membrane probes and the development of techniques for optically sectioning intact specimens have allowed glimpses of membrane dynamics to be visualized in living tissue. In this review we discuss the potential of a new optical sectioning technique, multiphoton imaging, for visualizing membrane dynamics in living cells. Multiphoton microscopy offers an unparalleled ability to obtain images from deep within specimens while minimizing the effects of phototoxicity.
A Microbial Strategy to Multiply in Macrophages: The Pregnant Pause
Authors: Swanson Michele S. , Fernandez‐Moreia Esteban
Published: March 2003

Humans live in harmony with much of the microbial world, thanks to a sophisticated immune system. As the first line of defense, macrophages engulf, digest, and display foreign material, then recruit specialists to eliminate potential threats. Yet infiltrators exist: certain fungi, viruses, parasites, and bacteria thrive within sentinel macrophages. By scrutinizing the life styles of these shrewd microbes, we can deduce how macrophages routinely mount an effective immune response. The bimorphic life cycles of three pathogens have dramatic consequences for phagosome traffic. In the transmissible state, Leishmania spp., Coxiella burnetii, and Legionella pneumophila block phagosome maturation; after a pregnant pause, replicative forms emerge and thrive in lysosomes.
Traffic Changes with Increased Flow
Authors: Brodsky Frances M.
Published: March 2003

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Mark Marsh
Sandra L. Schmidid
An Overview of C. Elegans Trafficking Mutants
Authors: Nurrish Stephen J.
Published: March 2003

It is almost 40 years since Sydney Brenner introduced Caenorhabditis elegans as a model genetic system. During that time mutants with defects in intracellular trafficking have been identified in a diverse range of screens for abnormalities. This should, of course, come as no surprise as it is hard to imagine any biological process in which the regulated movement of vesicles within the cells is not critical at some step. Almost all of these genes have mammalian homologs, and yet the role of many of these homologs has not been investigated. Perhaps the protein that regulates your favorite trafficking step has already been identified in C. elegans? Here I provide a brief overview of those trafficking mutants identified in C. elegans and where you can read more about them.
Dyneins Motor on in Plants
Authors: King Stephen M.
Published: March 2003

A recent report based on analysis of the Arabidopsis genome suggested that angiosperms do not contain the dynein microtubule motor. However, examination of the whole genome shotgun sequence for rice (Oryza sativa) has revealed that four dynein heavy chains are present in this monocot, indicating that the apparent lack of these sequences in Arabidopsis is not a general feature of angiosperm genomic organization. These observations also suggest that, in contrast to an earlier proposal, flowering plants may indeed use standard dynein‐driven mechanisms to perform cellular transport activities that, in other organisms, employ the dynein motor
CD2AP/CMS Regulates Endosome Morphology and Traffic to the Degradative Pathway Through its Interaction with Rab4 and c‐Cbl
Authors: Cormont Mireille , Metón Isidoro , Mari Muriel , Monzo Pascale , Keslair Frédérique , Gaskin Chantell , McGraw Timothy E. , Le Marchand‐Brustel Yannick
Published: March 2003

The small GTPase Rab4 is involved in endocytosis through sorting and recycling early endosomes. To better understand the role of Rab4 in regulation of vesicular trafficking, we searched for effectors that specifically interact with Rab4‐Q67L, the GTP‐bound form of Rab4. We cloned an ubiquitous 80‐kDa protein, identical to CD2‐associated protein/Cas ligand with multiple SH3 domains (CD2AP/CMS), that interacts with Rab4‐Q67L in the yeast two‐hybrid system and in vitro. CD2AP/CMS expressed in mammalian cells was localized to punctate structures and along actin filaments. None of the known markers of early endosomes [Early Endosomes Antigen 1 (EEA1), Rab5 and Rab11] colocalized with the CD2AP/CMS‐positive vesicles. However, coexpression of Rab4‐Q67L with CD2AP/CMS induces a significant enlargement of EEA1‐positive early endosomes. Rab4, CD2AP/CMS and Rab7 colocalized in these modified endosomes. Coexpression of c‐Cbl and CD2AP/CMS also resulted in an enlargement of early endosomes. Using various truncated forms of CD2AP/CMS, we demonstrate that early endosomes enlargement requires that CD2AP/CMS interacts with both Rab4 and c‐Cbl. The expression of a truncated form of CD2AP/CMS that retains the ability to interact with Rab4 but not c‐Cbl inhibits ligand‐induced PDGF receptor degradation. We propose that CD2AP/CMS, through interactions with Rab4 and c‐Cbl, controls early endosome morphology and may play a role in traffic between early and late endosomes, and thus in the degradative pathway.
Osteoclast Ruffled Border Has Distinct Subdomains for Secretion and Degraded Matrix Uptake
Authors: Mulari Mika T. K. , Zhao Haibo , Lakkakorpi Päivi T. , Väänänen H. Kalervo
Published: March 2003

Subosteoclastic bone resorption is a result of HCl and proteinase secretion through a late endosome‐like bone facing membrane domain called ruffled border. As bone matrix is degraded, it enters osteoclasts' transcytotic vesicles for further processing and is then finally exocytosed to the intercellular space. The present study clarifies the spatial relationship between these vesicle fusion and matrix uptake processes at the ruffled border. Our results show the presence of vacuolar H+‐ATPase, small GTPase rab7 as well as dense aggregates of F‐actin at the peripheral ruffled border, where basolaterally endocytosed transferrin and cathepsin K are delivered. On the contrary, rhodamine‐labeled bone matrix enters transcytotic vesicles at the central ruffled border, where the vesicle budding proteins such as clathrin, AP‐2 and dynamin II are also localized. We present a model for the mechanism of ruffled border turnover and suggest that, due to its late endosomal characteristics, the ruffled border serves as a valuable model for studying the dynamic organization of other endosomal compartments as well.
Clinical study of disseminated intravascular coagulation in oral and maxillofacial regions – predictors of onset and prognosis
Authors: Morimoto Y , Ikeuchi M , Yamamoto K , Kirita T , Sugimura M
Published: March 2003

OBJECTIVES: To examine disseminated intravascular coagulation (DIC) cases in detail to identify the predictors of onset and prognosis.

STUDY DESIGN: The clinical records of eight patients with DIC were examined with regard to the patient’s background, underlying disease, direct inducers, duration, contents of treatments and outcome. The factors which controlled the onset and prognosis of DIC were examined in cases receiving surgery for malignant neoplasm compared with non‐DIC cases. Wilcoxon test was used for statistical analysis.

RESULTS: There were seven males and one female, age range from 25 to 93 years. The underlying diseases were six malignant neoplasms, one severe infection, and one case of multiple injuries of the mandible. Seven patients had pretherapeutic complications, and six patients recovered. Reduction in platelet counts immediately after the operation revealed high values up to 36%, and patients with more than two pretherapeutic complications were more susceptible to DIC when major postoperative complications occurred. The operation time and blood loss may also have affected the outcome.

CONCLUSION: Change of platelet counts, number of pretherapeutic complications, operation time and blood loss are important for predicting the onset and prognosis of DIC in the oral and maxillofacial regions.
A novel point mutation (C571T) in the tissue‐non‐specific alkaline phosphatase gene in a case of adult‐type hypophosphatasia
Authors: Watanabe H , Hashimoto‐Uoshima M , Goseki‐Sone M , Orimo H , Ishikawa I
Published: March 2003

OBJECTIVE: Hypophosphatasia (HOPS) is an inheritable disorder characterized by defective skeletal mineralization, deficiency of tissue‐non‐specific alkaline phosphatase (TNSALP) activity and premature loss of deciduous teeth. The gene for TNSALP is located on chromosome 1p34‐36.1 and consists of 12 exons and 11 introns. In this study we analysed the genomic TNSALP gene from a patient with HOPS, her family, and unrelated normal controls.

MATERIALS AND METHODS: The proband was a 52‐year‐old Japanese woman with adult onset HOPS. The patient showed deficiency in alkaline phosphatase (ALP) activity, increased urinary excretion of phosphoethanolamine and severe periodontal disease. Genomic DNA was extracted from the peripheral leukocytes of the subjects. Based on published sequence data in the TNSALP gene, 11 pairs of polymerase chain reaction (PCR) primers were used to amplify the coding exons. The PCR amplified samples were subjected to PCR‐single strand conformation polymorphism (SSCP) analysis and PCR‐allele specific oligonucleotide (ASO) analysis.

RESULTS: By PCR‐SSCP analysis of the patient’s genomic DNA, fragments containing exon 5 revealed abnormal mobility. This abnormal mobility (exon 5) was also found in the genomic DNA in her mother’s sister, but were not detected in her father, brothers or sisters, and unrelated normal controls. Sequencing analysis of the abnormal band extracted from the SSCP gel revealed a C to T transition at nucleotide position 571 (C571T) in exon 5. This mutation resulted in a substitution of Ala‐115 with a Val in the mature TNSALP polypeptide. PCR‐ASO analysis also confirmed this missense point mutation. The result of this study showed that the proband has inherited the C571T mutation in exon 5 from her mother alone and the disease in this family was inherited as an autosomal dominant trait from the pedigree.

CONCLUSIONS: The C571T mutation is a new missense point mutation and appears to cause significant changes in the structure and function of TNSALP because Ala‐115 is highly conserved in rat TNSALP and human tissue‐non‐specific, intestinal and placental ALPs.
Clinical and radiographic features of a family with autosomal dominant amelogenesis imperfecta with taurodontism
Authors: Aldred MJ , Savarirayan R , Lamandé SR , Crawford PJM
Published: March 2003

This paper describes the clinical features of a family of four generations with autosomal dominant amelogenesis imperfecta with taurodontism (ADAIT). Considerable variation in phenotype was seen, both between individuals and within the dentition of some individuals. Many of the adults had received extensive dental restorative work. These findings re‐enforce previous observations of variable phenotype in this and other forms of the condition and add to the argument for a revision of methods of classification. This history of this large family draws further attention to the restorative demands of this group of dental anomalies and, by their generous co‐operation, will prove an invaluable help in the investigation by molecular genetic techniques of this disfiguring condition.
Expression of cytokeratins (CKs) 8, 13 and 18 and their mRNA in epithelial linings of radicular cysts: implication for the same CK profiles as nasal columnar epithelium in squamous epithelial lining
Authors: Lu D‐P , Tatemoto Y , Kimura T , Osaki T
Published: March 2003

OBJECTIVE: Our objective was to specify cytokeratin (CK) patterns in lining epithelia of radicular cysts which are sometime lined with ciliated columnar epithelia as seen in the nasal epithelia.

MATERIALS AND METHODS: We examined the CK expression in 52 radicular cysts obtained from 32 maxillary and 20 mandibular lesions and investigated CK‐mRNA expression using in situ hybridization in 24 maxillary and 13 mandibular cysts and reverse transcription‐polymerase chain reaction (RT–PCR) in 24 maxillary cysts.

RESULTS: Of the maxillary cysts, 20, 29 and 19 squamous epithelial linings were positive for CK8, CK13 and CK18, respectively; of the mandibular cysts, 10, 20 and 11 linings were positive for these CKs, respectively. The expression patterns of CK18(+)‐CK13(−), CK18(+)‐CK13(+) and CK18(−)‐CK13(+) were observed in 3, 16 and 13 linings of the maxillary cysts and 0, 11 and 9 linings of the mandibular cysts, respectively. In situ hybridization revealed the expression of CK18‐mRNA in 9 and 4 linings of 24 maxillary and 13 mandibular cysts examined, respectively. With RT‐PCR, we explored that both CK18‐ and CK13‐mRNA were expressed not only in the normal nasal and gingival epithelia but also in the examined maxillary cyst linings although their expression levels differed correlating with the difference in CK staining.

CONCLUSION: It is concluded that CK13‐ and CK18‐mRNA are constitutively expressed in columnar and squamous epithelial cells, respectively, and that the variant CK expression patterns with CK18‐mRNA expression in maxillary radicular cysts are indicative of the possibility of phenotypic transformation in the cyst linings.
Dynamics of the interaction between the insulin receptor and protein tyrosine‐phosphatase 1B in living cells
Authors: Boute Nicolas , Boubekeur Samira , Lacasa Danièle , Issad Tarik
Published: March 2003

The dynamics of the interaction of the insulin receptor with a substrate‐trapping mutant of protein‐tyrosine phosphatase 1B (PTP1B) were monitored in living human embryonic kidney cells using bioluminescence resonance energy transfer (BRET). Insulin dose‐dependently stimulates this interaction, which could be followed in real time for more than 30 minutes. The effect of insulin on the BRET signal could be detected at early time‐points (30 seconds), suggesting that in intact cells the tyrosine‐kinase activity of the insulin receptor is tightly controlled by PTP1B. Interestingly, the basal (insulin‐independent) interaction of the insulin receptor with PTP1B was much weaker with a soluble form of the tyrosine‐phosphatase than with the endoplasmic reticulum (ER)‐targeted form. Inhibition of insulin‐receptor processing using tunicamycin suggests that the basal interaction occurs during insulin‐receptor biosynthesis in the ER. Therefore, localization of PTP1B in this compartment might be important for the regulation of insulin receptors during their biosynthesis.
The soybean retroelement SIRE 1 uses stop codon suppression to express its envelope‐like protein
Authors: Havecker Ericka R , Voytas Daniel F
Published: March 2003

The soybean SIRE 1 family of Ty1/copia retrotransposons encodes an envelope ‐like gene (env ‐like). We analysed the DNA sequences of nine SIRE 1 insertions and observed that the gag /pol and env ‐like genes are in the same reading frame and separated by a single UAG stop codon. The six nucleotides immediately downstream of the stop codon conform to a degenerate nucleotide motif, CARYYA, which is sufficient to facilitate stop codon suppression in tobacco mosaic virus. In vivo stop codon suppression assays indicate that SIRE 1 sequences confer leakiness to the UAG stop codon at an efficiency of 5%. These data suggest that SIRE 1 retro‐elements use translational suppression to express their envelope‐like protein; this is in contrast with all characterized retroviruses, which express the envelope protein from a spliced genomic messenger RNA.
The haemochromatosis protein HFE induces an apparent iron-deficient phenotype in H1299 cells that is not corrected by co-expression of beta2-microglobulin
Authors: WANG Jian , CHEN Guohua , PANTOPOULOS Kostas
Published: March 2003

HFE, an atypical MHC class I type molecule, has a critical, yet still elusive function in the regulation of systemic iron metabolism. HFE mutations are linked to hereditary haemochromatosis type 1, a common autosomal recessive disorder of iron overload. Most patients are homozygous for a C282Y point mutation that abrogates the interaction of HFE with β2-microglobulin (β2M) and, thus, impairs its proper processing and expression on the cell surface. An H63D substitution is also associated with disease. To investigate the function of HFE we have generated clones of human H1299 lung cancer cells that express wild-type, C282Y or H63D HFE under the control of a tetracycline-inducible promoter. Consistent with earlier observations in other cell lines, the expression of wild-type or H63D, but not C282Y, HFE induces an apparent iron-deficient phenotype, manifested in the activation of iron-regulatory protein and concomitant increase in transferrin receptor levels and decrease in ferritin content. This phenotype persists in cells expressing wild-type HFE after transfection with a β2M cDNA. Whereas endogenous β2M is sufficient for the presentation of at least a fraction of chimeric HFE on the cell surface, this effect is stimulated by approx. 2.8-fold in β2M transfectants. The co-expression of exogenous β2M does not significantly affect the half-life of HFE. These results suggest that the apparent iron-deficient phenotype elicited by HFE is not linked to β2M insufficiency.