86 research outputs found
Apparently isolated ventricular septal defect, prenatal diagnosis, association with chromosomal aberrations, spontaneous closure rate in utero and during the first year of life: a systematic review
Aim: To evaluate the incidence of chromosomal aberrations in apparently isolated ventricular septal defects (VSD), quantify the timing of diagnosis of prenatally diagnosed VSDs, and define the spontaneous closure rate prenatally both in utero and during the first year of life. Materials and methods: Medline, PubMed, and the Cochrane Database Library were searched to identify studies published between January 2013 and January 2023 using keywords and word variant combinations for isolated ventricular septal defect, fetal echocardiography, karyotype, genetics, array CGH, spontaneous closure, and outcome. Inclusion criteria: studies reporting apparently isolated ventricular septal defect. Primary outcomes: to find the incidence of chromosomal aberrations in apparently isolated ventricular septal defects, and quantify the timing of diagnosis. Secondary outcome: to define the spontaneous closure rate in utero and in the first year of life. Statistical analysis was performed using Jamovi Meta-Analysis major package 2.3.21 Solid. To combine data, we used proportions and maximum likelihood ratios. Results: Overall, the maximum likelihood ratio of chromosomal aberrations in antenatally diagnosed apparently isolated VSD was 2.7%. The different types of defects showed substantially different rates of chromosomal aberrations. Muscular VSDs had a chromosomal aberrations rate of 0.4% vs. 4.8% for perimembranous VSDs. Mean gestational age of diagnosis was 25+4 days. Spontaneous closure rate maximum likelihood ratio in utero was 28.6%. Higher closure rate in utero was observed for the perimembranous type while muscular VSDs showed higher closure rates after birth. Closure in utero was observed in 28.9% of the perimembranous VSDs and in 14.5% of the muscular VSDs. Closure after 12 months was found in 22% for the perimembranous defects and in 53.8% for the muscular defects. The presented results could be of use in informed prenatal counseling and of great help in parental decision making. Conclusions: This systematic study included 740 isolated ventricular septal defects, of which 422 were muscular and 165 were perimembranous. Other types were not specified. One hundred fifty-nine perimembranous and 384 muscular VSDs were available for a follow-up after 12 months of life. Chromosomal aberrations were detected in 4.8% of the perimembranous VSDs and in 0.4% of the muscular VSDs
Inhibition of Intestinal Adenoma Formation in APCMin/+ Mice by Riccardin D, a Natural Product Derived from Liverwort Plant Dumortiera hirsuta
BACKGROUND: Mutation of tumor suppressor gene, adenomatous polyposis coli (APC), is the primary molecular event in the development of most intestinal carcinomas. Animal model with APC gene mutation is an effective tool for study of preventive approaches against intestinal carcinomas. We aimed to evaluate the effect of Riccardin D, a macrocyclic bisbibenzyl compound, as a chemopreventive agent against intestinal adenoma formation in APC(Min/+) mice. METHODS: APC(Min/+) mice were given Riccardin D by p.o. gavage for 7 weeks. Mice were sacrificed, and the number, size and histopathology of intestinal polyps were examined under a microscope. We performed immunohistochemical staining, western blotting, reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) in intestinal polyps to investigate the mechanism of chemopreventive effect of Riccardin D. RESULTS: Riccardin D treatment resulted in a significant inhibition of intestinal adenoma formation, showing a reduction of polyp number by 41.7%, 31.1% and 44.4%, respectively, in proximal, middle and distal portions of small intestine. The activity of Riccardin D against polyp formation was more profound in colon, wherein Riccardin D decreased polyp number by 79.3%. Size distribution analysis revealed a significant reduction in large-size polyps (2-3 mm) by 40.0%, 42.5% and 33.3%, respectively, in proximal, middle and distal portions of small intestine, and 77.8% in colon. Histopathological analysis of the intestinal polyps revealed mostly hyperplastic morphology without obvious dysplasia in Riccardin D-treated mice. Molecular analyses of the polyps suggested that the inhibitory effect of Riccardin D on intestinal adenoma formation was associated with its abilities of reduction in cell proliferation, induction of apoptosis, antiangiogenesis, inhibition of the Wnt signaling pathway and suppression of inflammatory mediators in polyps. CONCLUSIONS: Our results suggested that Riccardin D exerts its chemopreventive effect against intestinal adenoma formation through multiple mechanisms including anti-proliferative, apoptotic, anti-angiogenic and anti-inflammatory activity
Divergent cerebrospinal fluid cytokine network induced by non-viral and different viral infections on the central nervous system
THE BALKAN MOUNTAINS PALEOZOIC GOLD DEPOSITS
ABSTRACT A number of Paleozoic gold deposits are situated in the Hercynian terrains of the Balkan Mountain. On Bulgarian territory Govezhda and Svishti Plaz deposits are the most important ones. Neresnitza, Blagoev-Kamen and Osanitza deposits are located in the Serbian part of the Balkan Mountain. All these deposits are hosted in the Pre-Alpine basement of the Balkanide zone. The orehosting structures are veins, lenses and mineralized fissures related to tension and shear faults. The structural characteristics of the ores are an evidence for tectonic control and tectonic activity during the ore deposition. All stages of ore deposition were accompanied by strong fracturing of already deposited minerals and subsequent precipitation of next portion. The economically important mineral in all these deposits is the native gold, with variable Ag contents. In the two Bulgarian deposits the main ore minerals are arsenopyrite and pyrite. Arsenopyrite is not reported for Serbian deposits, but scheelite is a main mineral there instead. Based on mineral associations, three possible genetic concepts of Au deposition could be expressed. 1) The gold is genetically associated with arsenopyrite and pyrite from stage 1 (Fe-AsAu+W). It is primarily deposited as invisible gold in these minerals. During the next stage of sulfide deposition driven by induced heating, it is remobilized and redeposited in cracks, formed during the cataclastic events of this stage. 2) The gold is genetically connected to the stage 2 (Pb-Zn-Cu-AgAu). 3) Dual generation of gold related to both stages 1 and 2. All Balkan Paleozoic gold deposits show lots of similarities to mesothermal gold deposits in shear zones in Archaean greenschists terrains in Canada, Western Australia and Africa, as well as to Hercynian gold deposits in France and Portugal. The similarity especially concerns their connection to granodioritic magmatism, the mineral parageneses and the gold occurrence and its associations. Despite that the mining in the Balkan gold deposits is already closed, they still have nonexplored and non-operated reserves
Off-center Li
Substitutional impurity ions in crystals are known to displace
off-center and to perform hindered rotations around the ideal lattice
positions. The vibronic theory
to describe both the off-center displacements and the hindered rotations by
a single angular equation incorporates terms up to 3rd order in
the off-center displacement coordinates. When the rotation is confined to
a single plane, the corresponding vibronic equation is equivalent to Mathieu's
equation. Extending our earlier work, we derive here the
dipole-dipole coupling to take into account cooperative phenomena.
We also derive the optical absorption band arising from dipolar
transitions across “Mexican Hat” surfaces, and we show that hindered
rotations gives rise to magnetic moments quantized in rotational bands
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