Skin layer-specific Melan-A expression during progression of human cutaneous melanoma: implications for diagnostic applications of the marker.

Melan-A is widely used in the diagnostics of human melanoma. The immunogenicity of this glycoprotein makes it a potential target in immunotherapy and several authors have suggested its potential as a prognostic factor. Up to now there has been no clear direct evidence of changes of Melan-A expression during the progression of melanoma.

Transcriptional activity and distribution of splicing machinery elements during Hyacinthus orientalis pollen tube growth.

The localization of newly formed transcripts and molecules participating in pre-mRNA splicing, i.e., small nuclear ribonucleoproteins (snRNPs) and SC35 protein, in growing pollen tubes of Hyacinthus orientalis L.

Ethylene and ABA interactions in the regulation of flower induction in Pharbitis nil.

Hormones are included in the essential elements that control the induction of flowering. Ethylene is thought to be a strong inhibitor of flowering in short day plants (SDPs), whereas the involvement of abscisic acid (ABA) in the regulation of flowering of plants is not well understood. The dual role of ABA in the photoperiodic flower induction of the SDP Pharbitis nil and the interaction between ABA and ethylene were examined in the present experiments.

Vascular protection with candesartan after experimental acute stroke in hypertensive rats: a dose-response study.

We have shown that candesartan decreases the acute stroke-induced elevation of mean arterial blood pressure (MAP) in Wistar rats and improves functional outcome. The aim of the present study was to determine whether the same benefit could be achieved in spontaneously hypertensive rats (SHR). Animals were subjected to middle cerebral artery occlusion (MCAO) or sham for 3 h followed by reperfusion.

Light- and IAA-regulated ACC synthase gene (PnACS) from Pharbitis nil and its possible role in IAA-mediated flower inhibition.

The light- and indole-3-acetic acid (IAA)-regulated 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene (PnACS) from Pharbitis nil was isolated. Here, it was shown that the gene was expressed in cotyledons, petioles, hypocotyls, root and shoot apexes both in light- and dark-grown seedlings. The highest expression level of PnACS was found in the roots.

Intracellular distribution of phototropin 1 protein in the short-day plant Ipomoea nil.

Phototropin 1 (phot1) is a blue-light Ser/Thr receptor kinase that contains two LOV domains. It is a plasma membrane-associated protein that mediates phototropism, blue-light induced chloroplast movement, and stomatal opening. The aim of the present work was to analyze the intracellular localization of phot1 protein in Ipomoea nil seedlings.

Cholesterol sulphate sulphohydrolase of human placenta lysosomal membrane.

In this paper we report that the activity of cholesterol sulphate sulphohydrolase (CHS-ase) is associated with the lysosomal membranes. The procedure of purification of CHS-ase from human placenta lysosomes was elaborated. The purified enzyme is highly specific to cholesterol sulphate (specific activity 2126.

Additional nucleoli and NOR activity during meiotic prophase I in larch (Larix decidua Mill.).

Transcriptional activity was investigated in successive stages of prophase I (male meiosis) of larch meiocytes. Br-UTP incorporated into RNA was detected by light and electron microscopy. Two peaks of RNA synthesis were identified in the nucleolus.

Identification of enzyme activity that conjugates indole-3-acetic acid to aspartate in immature seeds of pea (Pisum sativum).

This study describes the first identification of plant enzyme activity catalyzing the conjugation of indole-3-acetic acid to amino acids. Enzymatic synthesis of indole-3-acetylaspartate (IAA-Asp) by a crude enzyme preparation from immature seeds of pea (Pisum sativum) was observed. The reaction yielded a product with the same Rf as IAA-Asp standard after thin layer chromatography.

Involvement of cyclic GMP in phytochrome-controlled flowering of Pharbitis nil.

Light is one of the most important environmental factors influencing the induction of flowering in plants. Light is absorbed by specific photoreceptors--the phytochromes and cryptochromes system--which fulfil a sensory and a regulatory function in the process. The absorption of light by phytochromes initiates a cascade of related biochemical events in responsive cells, and subsequently changes plant growth and development.

Cyclooxygenase-2 (COX-2): first immunohistochemical marker distinguishing early cutaneous melanomas from benign melanocytic skin tumours.

We have reported recently that changes in expression level of COX-2 are correlated with development and progression of human melanoma. In this study, we investigated whether the COX-2 expression level might be a useful immunohistochemical marker for distinguishing cutaneous melanomas from benign melanocytic lesions. Up to now, immunohistochemical markers have not ensured satisfactory sensitivity and specificity of differential pathologic diagnosis of melanoma.

Factors influencing the attachment strength of Dreissena polymorpha (Bivalvia).

The effects of several factors (shell length, exposure time, substratum orientation in space, illumination, temperature, conspecifics) upon the attachment strength (measured with a digital dynamometer) of the freshwater, gregarious bivalve Dreissena polymorpha were studied under laboratory conditions. A rapid increase in attachment strength was observed on resocart (a thermosetting polymer based on phenol-formaldehyde resin, with paper as filler) substrata during the first 4-d exposure, after which it stabilised at ca 1 N. The attachment strength increased also with mussel size.

Seasonal changes in cryoprotectants concentrations in Helix pomatia snails.

Terrestrial snails are often exposed to freezing. Therefore, we investigated seasonal shifts in hemolymph concentrations of cryoprotectants such as glycerol and glucose. We also investigated whether summer acclimation to cold and short-day photoperiod induced synthesis of cryoprotectants in Helix pomatia snails.

Is torpor only an advantage? Effect of thermal environment on torpor use in the Siberian hamsters (Phodopus sungorus).

The aim of our study was determine torpor use in the Siberian hamsters (Phodopus sungorus) tested in a wide gradient of ambient temperatures (T(a)). Experiments were done on fed and food-deprived animals acclimated to winter-like and summer-like conditions. We found that neither fed nor unfed hamsters acclimated to winter-like or summer-like conditions selected low T(a)'s and entered torpor.

Role of prostaglandins in heme-induced fever.

Brain stroke is often accompanied by a high fever, which is insensitive to a blockade with classic antipyretic drugs known to inhibit the synthesis of prostaglandin E(2) (PGE(2)), a proximal mediator of fever associated with infection. The molecular mechanism of fever associated with stroke is mostly unknown, and has not been thoroughly investigated. One characteristics of the stroke is an extravasation of the erythrocytes into the brain tissue followed by a release of hemoglobin and free heme.

Hypoxia-induced sickness behaviour.

Sickness behaviour (SB) consists of the set of adaptive responses of the host to severe infections and inflammation. It includes, among others, the thermoregulatory responses such as regulated increase (fever) and/or decrease (anapyrexia) of body temperature (T(b)), decrease of motor activity (lethargy), and loss of appetite (hypophagia) resulting in a transient loss of body weight. It is thought that SB is partially induced by the immune-derived mediators such as cytokines and prostaglandins acting on the central nervous system.

Stress-induced behaviour in adult and old rats: effects of neonatal asphyxia, body temperature and chelation of iron.

Perinatal asphyxia in mammals leads to iron accumulation in the brain, which results in delayed neurobehavioural disturbances, including impaired learning and abnormal alertness over their entire life span. The aim of this investigation was to verify our hypothesis that newborn rats, showing reduced normal body temperature, are protected against neurotoxicity of the asphyxia up to senescence. Alertness was studied in adult and old male Wistar rats after exposure to critical neonatal anoxia: (i) at physiological neonatal body temperature of 33 degrees C, (ii) at body temperature elevated to 37 degrees C, or (iii) at body temperature elevated to 39 degrees C (the thermal conditions remained unchanged both during anoxia and for 2 h postanoxia).

Animal responses to extreme conditions: a lesson to biomedical research.

Various animals must cope with some specific extreme environmental conditions and, as a consequence, they developed extremely efficacious adaptive defence responses. The mechanisms of the specific defences are more clearly visible in some species than in humans. Therefore, animal models of the human defence mechanisms should be selected accordingly.

Peptides of arachnid venoms with insecticidal activity targeting sodium channels.

Arachnids have a venom apparatus and secrete a complex chemical mixture of low molecular mass organic molecules, enzymes and polypeptide neurotoxins designed to paralyze or kill their prey. Most of these toxins are specific for membrane voltage-gated sodium channels, although some may also target calcium or potassium channels and other membrane receptors. Scorpions and spiders have provided the greatest number of the neurotoxins studied so far, for which, a good number of primary and 3D structures have been obtained.

Cyclin-dependent kinase 2 expression in human melanomas and benign melanocytic skin lesions.

Cyclin-dependent kinase 2 (CDK-2) is strongly involved in regulating the progression of the cell cycle through G1/S checkpoint and S phase. Numerous studies demonstrated increased levels of CDK-2 (and also of its regulatory cyclins E and/or A) in different types of human tumours. Correlations found between the expression of those cell cycle regulators and progression and/or invasiveness of some tumours indicated the importance of CDK-2 as a potential prognostic marker.

Environmental conditions, rather than season, determine torpor use and temperature selection in large mouse-eared bats (Myotis myotis).

We tested whether food availability, thermal environment and time of year affect torpor use and temperature selection in the large mouse-eared bat (Myotis myotis) in summer and winter. Food-deprived bats were torpid longer than bats offered food ad libitum. Bats placed in a gradient of low (0 degrees C-25 degrees C) ambient temperatures (T(a)) spent more time in torpor than bats in a gradient of high (7 degrees C-43 degrees C) T(a)'s.

Distribution of poly(A) RNA and splicing machinery elements in mature Hyacinthus orientalis L. pollen grains and pollen tubes growing in vitro.

The localization of poly(A) mRNA and molecules participating in pre-mRNA splicing, i.e., small nuclear ribonucleoproteins (snRNPs) and the SC35 protein, in mature Hyacinthus orientalis L.

Porcine skin as a model system for studies of ultraviolet a effects in human skin.

The range of diagnostic and therapeutic applications of ultraviolet A (UVA) radiation has been continuously expanding. UVA radiation is a well-known mutagenic factor capable of damaging both cells and tissues. At the same time there is a very limited information on long-term consequences of irradiating the skin with different doses of UVA and long-wavelength ultraviolet B (UVB) radiation used in therapies of skin disorders.

Different expression of lysosome-associated membrane protein-1 in human melanomas and benign melanocytic lesions.

Lysosome-associated membrane protein-1 is a protein with a significant content of beta1,6-branched N-glycans. It is thought that enhanced expression of lysosome-associated membrane protein-1 in tumour cells may promote invasion by influencing both adhesion to extracellular matrix and perhaps also binding to endothelial cells. The present study was aimed at examining levels of lysosome-associated membrane protein-1 in human melanomas and benign pigmented lesions to evaluate whether this protein might be considered a potential molecular marker of melanoma progression.

[Plasma membrane--order or chaos?].

In the influential "fluid mosaic" model of plasmalemma, transmembrane proteins drift regardless of lipids. Recently researches widen this to a view in which membrane lipids are not randomly distributed but they form liquid-ordered regions with local heterogenity, called lipid rafts. Lipid rafts are subdomains of the plaSma membrane that contain high concentration of cholesterol and glycosphingolipids.