A rosacea pathomechanizmusa

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Long-term changes of meteorological conditions of urban heat island development in the region of Debrecen, Hungary

Meteorological conditions have a remarkable im-pact on urban climate similarly to other local and microscale climates. Clear skies and calm weather are advantageous for the development of the urban heat island (UHI). There are numerous studies on the spatial and temporal features of the phenomenon. Much less attention is paid, however, to the meteorological conditions of UHI development. The aim of the present paper is to reveal the characteristics of the changes in the frequencies of advantageous and disadvantageous me-teorological conditions for UHI development on the basis of a 50-year-long time series. Meteorological condition categories of UHI development have been established on the basis of wind speed values, cloudiness, and precipitation ranging from advantageous to disadvantageous conditions. Frequencies of occurrence of condition categories of UHI development were determined first. Advantageous and moderately advantageous conditions were found to be dominant in the time series. Linear trend analysis revealed a significant increasing trend in the time series of advantageous conditions. Increase of the frequencies of advantageous conditions was analyzed for the years, seasons, and months of the study period as well. Spring and summer (April and June) produced significant increasing trends of frequencies of advantageous conditions, while winter (with the exception of February) and autumn did not show significant increase of those frequencies. Change-point anal-yses detected a significant increase in the frequency of advan-tageous conditions in the time series at the turn of 1981/1982 especially in the summer and spring months. Detected tenden-cies have negative effects on urban energy consumption: they contribute to the increase of air conditioning energy demand in the summer and do not decrease the energy demand of heating in the winter significantly

A thymic stromal lymphopoietin szerepe a bőrben és egyéb barriereken

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A városi hőmérsékleti többlet területi eloszlásának statisztikus modellezése a beépítettségi paraméter alapján, Szegeden és Debrecenben

A városi települések leginkább kutatott éghajlati sajátossága az ún városi hősziget (Urban Heat Island, UHI), mely az erősen urbanizált részek és a külterületek között kimutatható jelentős hőmérsékleti különbségben realizálódik. A hősziget intenzitása a városi területek esetében szignifikáns időbeli és térbeli változást mutat (Oke, 1997; Kuttler, 1998). Általánosságban elmondhatjuk, hogy a hősziget markáns kifejlődéséhez kedvező időjárási helyzetet a csapadék hiánya, a szélcsend vagy gyenge szél és a kevés felhőzet jellemzi. A kialakult hősziget intenzitásának maximumát leggyakrabban néhány órával napnyugta után tapasztalhatjuk (Oke and Maxwell, 1975). A városi hőmérsékleti többlet – a hősziget – kialakításában meghatározó szerepet játszó fizikai folyamatok rendkívül bonyolultak, hiszen időbeli lefutásuk gyors és egy erősen változó geometriájú és sokféle anyagminőségű városi felszínen keresztül fejtik ki hatásaikat. Ennek ellenére, a szakirodalomban fellelhetőek az UHI intenzitás becslésére statisztikus modellek: pl. szélsebesség, területhasznosítási típusok, népesség alapján (Park, 1986); rövidhullámú besugárzás, szélsebesség és felhőzet mennyisége alapján (Chow et. al., 1994); beépítettségi arány, magasság, szélsebesség, idő, hőmérsékleti amplitudó alapján (Kuttler et. al., 1996); beépítettségi arány, égbolt-láthatósági index, épületmagasság, vízfelszín arány alapján (Bottyán and Unger, 2003). Munkánk során – a fentiekből kiindulva – statisztikus modellek segítségével adunk becslést az átlagos maximális UHI intenzitás területi eloszlására Szegeden és Debrecenben, figyelembe véve a városi felszínek eltérő beépítettségi tulajdonságát, valamint az évszakos változékonyságot

A ferritin szerepe a szőlő stressztűrő képességének fokozásában = The role of ferritin in enhancing the stress tolerance of grapevine

Embriogén kalluszt állítottuk elő Richter110 (alany) és Chardonnay (nemes) szőlő fajták portokajiból. Ezeket Medicago sativa ferritint (MsFerr) tartalmazó Agrobacterium vektorokkal transzformáltunk. A DNS beépülését genomikus PCR-rel ellenőriztük. Poliklonális ellenanyagot állítottunk elő, mellyel megállapítottuk, hogy a transzláció magas szintű volt, a transzkriptumból nagy mennyiségű, megfelelően processzált fehérjetermék keletkezett. A transzgenikus szőlő növények elkészültéig dohányban teszteltük az MsFerr gént tartalmazó konstrukciókat. A teljes növényeken végzett UV-B kezelés, ill. levélkorongok közvetlen oxidatív stresszre adott válaszai alapján megállapítottuk, hogy az MsFerr növények toleránsabbak voltak, mint a nem expresszáló kontrollok. Az MsFerr Richter 110 növények regenerálása, szelekciója és felszaporítása sikeres volt, az MsFerr Chardonnay növények felszaporítása azonban hajtásnövekedési problémák miatt nem sikerült. Három MsFerr Richter 110 vonalat vizsgáltunk. Gyökér stresszként fás szárú dugványok tápoldatához hidrogénkarbonátot adtunk, ami klorotikus és levél száradási tünetek okozott Ebben nem kaptunk lényeges különbséget a transzgenikus és transzformálatlan növények között. Ezzel szemben, a leveleket érő hatásokkal: paraquat, NaCl só-stressz és tBHP indukált lipid peroxidációval szemben az MsFerr expresszáló vonalak toleránsabbak voltak (kisebb stressz-indukált fotoszintézis csökkenést mutattak) mint a transzformálatlanok. | Embryogenic calli were started from anthers of Richter 110 (rootstock) and Chardonnay (scion) grapevine and transformed with Agrobacterium harbouring Medicago sativa ferritin gene (MsFerr). Genomic PCR and protein immunoblotting using a polyclonal antibody confirmed that the transcription and processing of MsFerr was successful. Regeneration, selection and propagation of MsFerr Richter 110 plants was successful, but transformed MsFerr Chardonnay plants did not grow sufficiently. Until transgenic grapevine plants became available, preliminary experiments were carried out with MsFerr expressing tobacco. UV-B irradiation of whole plants as well as treatments of leaf disks with various chemical elicitors showed that MsFerr plants were more stress tolerant than non-expressing controls. After regeneration and propagation, three transgenic MsFerr Richter 110 lines were tested. Roots of green cuttings were stressed by flooding and in this experiment transgenic plants did not show significantly higher tolerance to hypoxia/bicarbonate than non-transferred ones. Leaves, however, showed increased tolerance to paraquat, salt stress and tBHP induced lipid peroxidation: their photosynthesis was less affected by these stressors than those from non-transformed plants

Acne: Transient Arrest in the Homeostatic Host-Microbiota Dialog?

We propose that acne vulgaris represents a naturally developing, transient inflammatory interaction of adolescent facial skin with its new microbial/chemical milieu (Cutibacterium acnes, sebum), replacing a state of previous childhood skin homeostasis. This concept might explain why acne is characterized by strong regional and age specificity, prevalent occurrence, and resolution

Cryptogenic postpartum stroke

An estimated 25–40% of ischemic strokes are classified as cryptogenic, which means the cause of the cerebral infarction remains unidentified. One of the potential pathomechanisms – especially among young patients with no cardiovascular risk factors – is paradoxical embolism through a patent foramen ovale. Pregnancy, cesarean delivery and the postpartum period are associated with an increased risk of cerebrovascular events. Factors that may contribute to ischemic strokes during gestation and puerperium include classic cardiovascular risk factors, changes in hemostaseology/hemodynamics, and pregnancy-specific disorders such as pre-eclampsia, eclampsia, postpartum cerebral angiopathy or peripartum cardiomyopathy. In this case report, we present a 36-year-old thrombolysis candidate undergoing mechanical thrombectomy 3 weeks after a cesarean section due to HELLP-syndrome. After evaluation of anamnestic and diagnostic parameters, closure of the patent foramen ovale has been performed. In the absence of specific guidelines, diagnostic work-up for cryptogenic stroke should be oriented after the suspected pathomechanism based on patient history and clinical picture. As long as definite evidences emerge, management of cryptogenic stroke patients with pathogenic right-to-left shunt remains individual based on the mutual decision of the patient and the multidisciplinary medical team

Acne: Transient Arrest in the Homeostatic Host-Microbiota Dialog?

We propose that acne vulgaris represents a naturally developing, transient inflammatory interaction of adolescent facial skin with its new microbial/chemical milieu (Cutibacterium acnes, sebum), replacing a state of previous childhood skin homeostasis. This concept might explain why acne is characterized by strong regional and age specificity, prevalent occurrence, and resolution

Amyloid-β1-42 Disrupts Synaptic Plasticity by Altering Glutamate Recycling at the Synapse.

Alzheimer's disease (AD) is the most prevalent form of neurodegenerative disorders characterized by neuritic plaques containing amyloid-β peptide (Aβ) and neurofibrillary tangles. Evidence has been reported that Aβ(1-42) plays an essential pathogenic role in decreased spine density, impairment of synaptic plasticity, and neuronal loss with disruption of memory-related synapse function, all associated with AD. Experimentally, Aβ(1-42) oligomers perturb hippocampal long-term potentiation (LTP), an electrophysiological correlate of learning and memory. Aβ was also reported to perturb synaptic glutamate (Glu)-recycling by inhibiting excitatory-amino-acid-transporters. Elevated level of extracellular Glu leads to activation of perisynaptic receptors, including NR2B subunit containing NMDARs. These receptors were shown to induce impaired LTP and enhanced long-term depression and proapoptotic pathways, all central features of AD. In the present study, we investigated the role of Glu-recycling on Aβ(1-42)-induced LTP deficit in the CA1. We found that Aβ-induced LTP damage, which was mimicked by the Glu-reuptake inhibitor TBOA, could be rescued by blocking the NR2B subunit of NMDA receptors. Furthermore, decreasing the level of extracellular Glu using a Glu scavenger also restores TBOA or Aβ induces LTP damage. Overall, these results suggest that reducing ambient Glu in the brain can be protective against Aβ-induced synaptic disruption

Abeta(1-42) Enhances Neuronal Excitability in the CA1 via NR2B Subunit-Containing NMDA Receptors

Neuronal hyperexcitability is a phenomenon associated with early Alzheimer's disease. The underlying mechanism is considered to involve excessive activation of glutamate receptors; however, the exact molecular pathway remains to be determined. Extracellular recording from the CA1 of hippocampal slices is a long-standing standard for a range of studies both in basic research and in neuropharmacology. Evoked field potentials (fEPSPs) are regarded as the input, while spiking rate is regarded as the output of the neuronal network; however, the relationship between these two phenomena is not fully clear. We investigated the relationship between spontaneous spiking and evoked fEPSPs using mouse hippocampal slices. Blocking AMPA receptors (AMPARs) with CNQX abolished fEPSPs, but left firing rate unchanged. NMDA receptor (NMDAR) blockade with MK801 decreased neuronal spiking dose dependently without altering fEPSPs. Activating NMDARs by small concentration of NMDA induced a trend of increased firing. These results suggest that fEPSPs are mediated by synaptic activation of AMPARs, while spontaneous firing is regulated by the activation of extrasynaptic NMDARs. Synaptotoxic Abeta(1-42) increased firing activity without modifying evoked fEPSPs. This hyperexcitation was prevented by ifenprodil, an antagonist of the NR2B NMDARs. Overall, these results suggest that Abeta(1-42) induced neuronal overactivity is not dependent on AMPARs but requires NR2B