Carrier-envelope phase controlled isolated attosecond pulses in the nm wavelength range, based on superradiant nonlinear Thomson-backscattering

A proposal for a novel source of isolated attosecond XUV -- soft X-ray pulses with a well controlled carrier-envelope phase difference (CEP) is presented in the framework of nonlinear Thomson-backscattering. Based on the analytic solution of the Newton-Lorentz equations, the motion of a relativistic electron is calculated explicitly, for head-on collision with an intense fs laser pulse. By using the received formulae, the collective spectrum and the corresponding temporal shape of the radiation emitted by a mono-energetic electron bunch can be easily computed. For certain suitable and realistic parameters, single-cycle isolated pulses of ca. 20 as length are predicted in the XUV -- soft X-ray spectral range, including the 2.33-4.37 nm water window. According to our analysis, the generated almost linearly polarized beam is extremely well collimated around the initial velocity of the electron bunch, with considerable intensity and with its CEP locked to that of the fs laser pulse.Comment: 11 pages, 6 figures, reviewed, corrected and extended work, regarding the intensity dependence of the emitted attosecond puls

Diatomic molecule in a strong infrared laser field: level-shifts and bond-length change due to laser-dressed Morse potential

We present a general mathematical procedure to handle interactions described by a Morse potential in the presence of a strong harmonic excitation. We account for permanent and field-induced terms and their gradients in the dipole moment function, and we derive analytic formulae for the bond-length change and for the shifted energy eigenvalues of the vibrations, by using the Kramers-Henneberger frame. We apply these results to the important cases of $\mathrm{H}_{2}$ and $\mathrm{LiH}$, driven by a near- or mid-infrared laser in the $10^{13}$ $\mathrm{ W/cm^2}$ intensity range

Macroprolactinaemiával társuló hypophysismacroadenoma kezelése quinagoliddal = Macroprolactinemia associated with pituitary macroadenoma: treatment with quinagolide

A jelenlegi általános nézet szerint a makroprolaktin biológiailag inaktív molekula, ezért szérumkoncentrációjának növekedése aligha bír patológiai jelentőséggel. A szerzők 80 éves férfi esetét ismertetik, akinél egyéb társbetegségek mellett sella-MR-vizsgálattal 21×12×12 mm-es intra- és parasellaris hypophysisadenomát mutattak ki. A szérumprolaktin-vizsgálat jelentős mértékű macroprolactinaemiát igazolt (összes prolaktin: 514 ng/ml, referenciatartomány 1,6–10,7 ng/ml; makroprolaktin 436 ng/ml, monomer prolaktin 78,2 ng/ml). A hypophysis-pajzsmirigy tengely vizsgálata szubklinikai primer hypothyreosist mutatott ki, a hypophysis-mellékvese tengely működése normális volt. Egyéb hormonleletei a normális tartomány alsó harmadában levő gonadotrophormon-szintek mellett csökkent tesztoszteronszintet, valamint normális inzulinszerű növekedési faktor-1-szintet igazoltak. Bár a jelenlegi szakmai ajánlások többsége macroprolactinaemia esetén feleslegesnek tartja a prolaktintermelő hypophysisadenomákban és egyéb valódi hyperprolactinaemiás állapotokban kiváló hatású dopaminagonista kezelést, a szerzők dopaminagonista quinagolidkezelést alkalmaztak. A tartós gyógyszeres kezelés a prolaktinszintet csaknem normálisra csökkentette (12,3 ng/ml), és kilenc hónappal a kezelés megkezdése után elvégzett sella-MR-vizsgálat a hypophysisdaganat mintegy negyedére zsugorodását mutatta ki. A szerzők felvetik, hogy esetükben a prolaktintermelő adenoma makroprolaktint is termelt, és javasolják macroprolactinaemiával társuló hypophysismacroadenomák esetében a dopaminagonista kezelés megkísérlését. | According to current concept, macroprolactin is biologically inactive and, therefore, its accumulation in serum has little, if any, pathological significance. Authors present the history of a 80-year-old man who proved to have, among other associated disorders, an intra- and parasellar pituitary tumor measuring 21×12×12 mm in size which was revealed by pituitary MRI. His hormonal evaluation indicated a marked hyperprolactinemia mainly due to macroprolactinemia (total prolactin, 514 ng/ml; reference range, 1.6–10.7 ng/ml; macroprolactin 436 ng/ml, monomer prolactin 78.2 ng/ml). Tests for function of the pituitary-thyroid axis showed a mild subclinical primary hypothyroidism. The function of the pituitary-adrenal axis was normal, and other hormonal tests revealed low-normal serum gonadotropins and decreased testosterone level, whereas serum insulin-like growth factor I was normal. Although the majority of current guidelines state that dopamine-agonist treatment which is successfully used in prolactin-producing pituitary tumors and in other hyperprolactinemic disorders is unnecessary in patients with macroprolactinemia, the authors introduced a dopamine-agonist, quinagolide. During prolonged treatment, plasma prolactin returned close to the upper limit of normal (12.3 ng/ml) and 9 months after the beginning of treatment pituitary MRI showed a remarkable shrinkage of the pituitary tumor. Authors propose that in this patient the pituitary tumor secreted macroprolactin, and they recommend a treatment trial with dopamine-agonist in pituitary macroadenomas associated with macroprolactinemia

A mikro-RNS-ek szerepe az agyalapimirigy-daganatok tumorbiológiájában

Abstract: MicroRNAs (miRNAs) are short, single stranded RNA molecules which play regulatory roles through posttranscriptional regulation of their target genes. Based on our current knowledge, more than 30% of the human protein-coding genes are regulated by miRNAs, hence influencing basic cellular mechanisms including cell proliferation, differentiation and cell death. Differential miRNA expression pattern has been detected in many different types of tumors and, recently, several publications have referred to miRNAs as potential therapeutic targets. Through adjustment of miRNA levels by artificial miRNAs administration or miRNA inhibition, we can influence not only one target gene but also complex biological pathways. Pituitary adenoma is the second most frequent intracranial tumor. In spite of this, the molecular mechanism of the pituitary adenoma formation is not yet entirely revealed. Recently, more and more evidences have been found suggesting that miRNAs have an important role in pituitary adenoma pathogenesis. Here, we summarize the recent results related to this role and highlight the therapeutic potentials in pituitary adenomas. Orv Hetil. 2018; 159(7): 252?259

A neokortikális és hippocampális epilepsziák komplex elektrofiziológiai rétegelvezetéses és szövettani vizsgálata emberben = Complex laminar electrophysiological and histological examination of the human neocortical and hippocampal epilepsies

Az OITI és a MTA PKI együttműködésében részletesen kidolgoztuk az intraoperatív és krónikus multielektróda beültetés technikai feltételeit és a vizsgálatok forgatókönyvét. Létrehoztunk egy kombinált multielektródás és konvencionális klinikai grid-sztrip elektródos elvezető rendszert, mely segítségével az operáció alatt, illetve krónikusan tudunk elvezetni intrahippokampális, intrakortikális, valamint szubdurális potenciálokat. Kimutattuk a szubikulumban generált különféle epilepsziás kisülések és a laterális temporális kéreg aktivitásának kapcsolatait, kimutattuk továbbá az alvásban és epilepsziában fontos K-komplexum generátorainak kérgi eredetét. Vizsgáltuk az alvási oszcilláció és az epilepsziás események kapcsolatát, kimutattuk, hogy epilepsziás emberben a felszínhez közeli kérgi rétegek igen erős szinaptikus és tüzelési aktivitást mutatnak az alvási oszcilláció aktív fázisában. Kimutattuk továbbá, hogy az aktív fázis csoportosítja az epilepsziás kisüléseket. A kérgi elektromos ingerlés hatását vizsgálva epilepsziás betegeken megállapítottuk, hogy a rövid elektromos ingerek inaktiválják a kérget, amit későbbiekben terápiás céllal lehet hasznosítani. | In collaboration with the OITI and MTA PKI we have worked out in details the intraoperative and chronic multielectrode implantation technique and the schedule of the investigation. We have established a combined system composed of the conventional clinical grid and strip based electrophysiology apparatus and the novel investigational multielectrode system to measure intrahippocampal, intracortical and subdural potentials chronically and intraoperatively. We have shown the relationship of the subicular and lateral temporal lobe epileptic discharges, we have also shown the cortical origin of the K-complex, an important brain wave in sleep and epilepsy. We have investigated the slow sleep oscillation and its relationship to epilepsy. The slow waves were originated in the superficial layers of the cortex and the epileptiform discharges were grouped by the up-states of the slow oscillation. Investigating the effect of electrical stimulation, we have shown that brief current pulses can inactivate the cortex, which effect can also be exploited in the therapy of epilepsy

Enhanced expression of potassium-chloride cotransporter KCC2 in human temporal lobe epilepsy

Synaptic reorganization in the epileptic hippocampus involves altered excitatory and inhibitory transmission besides the rearrangement of dendritic spines, resulting in altered excitability, ion homeostasis, and cell swelling. The potassium-chloride cotransporter-2 (KCC2) is the main chloride extruder in neurons and hence will play a prominent role in determining the polarity of GABAA receptor-mediated chloride currents. In addition, KCC2 also interacts with the actin cytoskeleton which is critical for dendritic spine morphogenesis, and for the maintenance of glutamatergic synapses and cell volume. Using immunocytochemistry, we examined the cellular and subcellular levels of KCC2 in surgically removed hippocampi of temporal lobe epilepsy (TLE) patients and compared them to control human tissue. We also studied the distribution of KCC2 in a pilocarpine mouse model of epilepsy. An overall increase in KCC2-expression was found in epilepsy and confirmed by Western blots. The cellular and subcellular distributions in control mouse and human samples were largely similar; moreover, changes affecting KCC2-expression were also alike in chronic epileptic human and mouse hippocampi. At the subcellular level, we determined the neuronal elements exhibiting enhanced KCC2 expression. In epileptic tissue, staining became more intense in the immunopositive elements detected in control tissue, and profiles with subthreshold expression of KCC2 in control samples became labelled. Positive interneuron somata and dendrites were more numerous in epileptic hippocampi, despite severe interneuron loss. Whether the elevation of KCC2-expression is ultimately a pro- or anticonvulsive change, or both-behaving differently during ictal and interictal states in a context-dependent manner-remains to be established