149 research outputs found
Annelated medium-sized azaheterocycles as attractive scaffolds for CNS targeted leads.
Medium-sized nitrogen heterocycles (7-to-15-membered) have widespread interest in organic synthesis and medicinal chemistry. Indeed, such heterocyclic rings are found as subunits or core structures in natural and bioactive molecules, including pharmaceutical products, whereas on the other hand they often can serve as key intermediates in the synthesis of bicyclic compounds by selective transformations (e.g., transannular ring-contractions, cycloadditions). These molecular frameworks, particularly annelated 7-to-10-membered aza-heterocycles, have long drawn our attention as potential scaffolds for developing new multitarget- directed ligands (MTDLs) for treating Alzheimer's disease (AD) and other neurodegenerative syndromes.AD, the most common form of dementia affecting people worldwide, is a progressive neurodegenerative disorder, whose multifactorial pathogenesis is still not completely understood. The main histopathological changes include synaptic dysfunction and neuronal loss resulting from intracellular and extracellular fibrillar aggregates of Beta-amyloid (Abeta),hyperphosphorilated and beta-folded tau proteins, cholinergic impairment, oxidative stress, neuroinflammation, metal dys-homeostasis and mitochondrial damage. Among others, N- methyl-D-aspartate receptors (NMDARs) play a major role in learning and memory, and their overactivation causes excessive calcium influx and consequent excitotoxicity, which is associated with CNS diseases, including Parkinson's disease.
Starting from our old1,2 and recent 3 findings on the suitability of partially hydrogenated benzo-, chromane-4- one- and indole-fused azepine and azocine derivatives targeted at enzymes, receptors and biochemical pathways involved in the pathogenesis of AD, we extended the investigation to novel derivatives of annelated azonines and azecines.
Herein, our recent advances of benzo- and indol-fused 7-to-10-membered nitrogen heterocycles as molecular tools for AD-associated targets (e.g., butyryl- and acetylcholinesterase, monoamine oxidases A and B, Abeta aggregation, ROS insult, NMDAR antagonist), along with the results from investigation on cell and ex vivo/in vivo animal models, will be presented and discussed in an effort of rationalizing structure-activity relationships and progressing drug optimization of the examined CNS-targeted lead compounds
ADAMTS2 gene dysregulation in T/myeloid mixed phenotype acute leukemia.
Background: Mixed phenotype acute leukemias (MPAL) include acute leukemias with blasts that express antigens
of more than one lineage, with no clear evidence of myeloid or lymphoid lineage differentiation. T/myeloid (T/My)
MPAL not otherwise specified (NOS) is a rare leukemia that expresses both T and myeloid antigens, accounting
for less than 1% of all leukemias but 89% of T/My MPAL. From a molecular point of view, very limited data are
available on T/My MPAL NOS.
Case presentation: In this report we describe a T/My MPAL NOS case with a complex rearrangement involving
chromosomes 5 and 14, resulting in overexpression of the ADAM metallopeptidase with thrombospondin type 1
motif, 2 (ADAMTS2) gene due to its juxtaposition to the T cell receptor delta (TRD) gene segment.
Conclusion: Detailed molecular cytogenetic characterization of the complex rearrangement in the reported T/My
MPAL case allowed us to observe ADAMTS2 gene overexpression, identifying a molecular marker that may be useful
for monitoring minimal residual disease. To our knowledge, this is the first evidence of gene dysregulation due to a
chromosomal rearrangement in T/My MPAL NOS.
Keywords: Mixed phenotype acute leukemia, ADAMTS2, TRD, Complex chromosomal rearrangement, Promoter
swapping, Gene dysregulatio
Absolute quantification of the pretreatment PML-RARA transcript defines the relapse risk in acute promyelocytic leukemia.
In this study we performed absolute quantification of the PML-RARA transcript by droplet digital polymerase chain reaction (ddPCR) in 76 newly diagnosed acute promyelocytic leukemia (APL) cases to verify the prognostic impact of the PML-RARA initial molecular burden. ddPCR analysis revealed that the amount of PML-RARA transcript at diagnosis in the group of patients who relapsed was higher than in that with continuous complete remission (CCR) (272 vs 89.2 PML-RARA copies/ng, p = 0.0004, respectively). Receiver operating characteristic analysis detected the optimal PML-RARA concentration threshold as 209.6 PML-RARA/ng (AUC 0.78; p < 0.0001) for discriminating between outcomes (CCR versus relapse). Among the 67 APL cases who achieved complete remission after the induction treatment, those with > 209.6 PML-RARA/ng had a worse relapse-free survival (p = 0.0006). At 5-year follow-up, patients with > 209.6 PML-RARA/ng had a cumulative incidence of relapse of 50.3% whereas 7.5% of the patients with suffered a relapse (p < 0.0001). Multivariate analysis identified the amount of PML-RARA before induction treatment as the sole independent prognostic factor for APL relapse.
Our results show that the pretreatment PML-RARA molecular burden could therefore be used to improve risk stratification in order to develop more individualized treatment regimens for high-risk APL cases
Measurement of the angular correlation between the two gamma rays emitted in the radioactive decays of a Co source with two NaI(Tl) scintillator
We implemented a didactic experiment to study the angular correlation between
the two gamma rays emitted in typical Co radioactive decays. We used two
NaI(Tl) scintillators, already available in our laboratory, and a low-activity
Co source. The detectors were mounted on two rails, with the source at
their center. The first rail was fixed, while the second could be rotated
around the source. We performed several measurements by changing the angle
between the two scintillators in the range from to .
Dedicated background runs were also performed, removing the source from the
experimental setup. We found that the signal rate increases with the angular
separation between the two scintillators, with small discrepancies from the
theoretical expectations.Comment: 15 pages, 12 figure
Extraordinary Molecular Evolution in the PRDM9 Fertility Gene
Recent work indicates that allelic incompatibility in the mouse PRDM9 (Meisetz) gene can cause hybrid male sterility, contributing to genetic isolation and potentially speciation. The only phenotype of mouse PRDM9 knockouts is a meiosis I block that causes sterility in both sexes. The PRDM9 gene encodes a protein with histone H3(K4) trimethyltransferase activity, a KRAB domain, and a DNA-binding domain consisting of multiple tandem C2H2 zinc finger (ZF) domains. We have analyzed human coding polymorphism and interspecies evolutionary changes in the PRDM9 gene. The ZF domains of PRDM9 are evolving very rapidly, with compelling evidence of positive selection in primates. Positively selected amino acids are predominantly those known to make nucleotide specific contacts in C2H2 zinc fingers. These results suggest that PRDM9 is subject to recurrent selection to change DNA-binding specificity. The human PRDM9 protein is highly polymorphic in its ZF domains and nearly all polymorphisms affect the same nucleotide contact residues that are subject to positive selection. ZF domain nucleotide sequences are strongly homogenized within species, indicating that interfinger recombination contributes to their evolution. PRDM9 has previously been assumed to be a transcription factor required to induce meiosis specific genes, a role that is inconsistent with its molecular evolution. We suggest instead that PRDM9 is involved in some aspect of centromere segregation conflict and that rapidly evolving centromeric DNA drives changes in PRDM9 DNA-binding domains
Best practices in heterotrophic high-cell-density microalgal processes: achievements, potential and possible limitations
Microalgae of numerous heterotrophic genera (obligate or facultative) exhibit considerable metabolic versatility and flexibility but are currently underexploited in the biotechnological manufacturing of known plant-derived compounds, novel high-value biomolecules or enriched biomass. Highly efficient production of microalgal biomass without the need for light is now feasible in inexpensive, well-defined mineral medium, typically supplemented with glucose. Cell densities of more than 100Â gâlâ1 cell dry weight have been achieved with Chlorella, Crypthecodinium and Galdieria species while controlling the addition of organic sources of carbon and energy in fedbatch mode. The ability of microalgae to adapt their metabolism to varying culture conditions provides opportunities to modify, control and thereby maximise the formation of targeted compounds with non-recombinant microalgae. This review outlines the critical aspects of cultivation technology and current best practices in the heterotrophic high-cell-density cultivation of microalgae. The primary topics include (1) the characteristics of microalgae that make them suitable for heterotrophic cultivation, (2) the appropriate chemical composition of mineral growth media, (3) the different strategies for fedbatch cultivations and (4) the principles behind the customisation of biomass composition. The review confirms that, although fundamental knowledge is now available, the development of efficient, economically feasible large-scale bioprocesses remains an obstacle to the commercialisation of this promising technology
Le attivitĂ di mantenimento della pace nei rapporti tra Nazioni Unite e organizzazioni regionali (II parte)
The development of relations between UN and regional organizations in
the maintenance of peace (including the management of conflicts with
destabilizing effects for the States concerned) has been favored by the
absence of a predetermined notion of âregional organizationâ in Chap. VIII
of the UN Charter. These entities have gradually assumed duties in relation
to the maintenance of peace and international security. In view of the
application of Chap.VIII, account should be taken of the treaties upon which
regional organizations are founded. Among these treaties, there is the
founding document of the African Union, complemented by the Protocol
setting up AU Council. This is given the power to authorize peace-keeping
operations, which are kept distinct from any intervention on behalf of the
Union. The rules in question cannot be interpreted in isolation, they must be
interpreted and applied by the States operating within the AU and its Council
in accordance with the combined provisions of Articles 2, par. 4, 24, and 53
of the UN Charter. The view that recognizes the autonomy of the AU
Council from the UN Security Council is not reflected in practice. The
emerging partnership with UN appears to be characterized by a dependence
of the regional organization on the resources provided by the UN, as well as
by other regional organizations (such as the EU and NATO) and Western
States. The Security Council has rarely invoked Chap. VIII, and has
recurrently acted on the basis of Chap.VII. The reference to Chap. VII is
indicative of the seriousness of the situation: the resolutions of the Security
160 Ancorché con riferimento a situazioni diverse, v. PICONE, Considerazioni, cit., 216 ss.
161 In argomento v. BOISSON DE CHAZOURNES, op. cit., 288; con indicazioni (in nota 629)
sul valore da riconoscere a un consenso successivo rispetto al momento in cui debba essere
reso, LLOPS, op. cit., 344 ss.; CONFORTI, FOCARELLI, op. cit., 347.
MANTENIMENTO DELLA PACE E RAPPORTI UN/ORGANIZZAZIONI REGIONALI 27
Council are to be understood in the light not only of their contents but also of
the relevant operational context. On this basis it is possible to understand
what the effects of their adoption in any specific case may be. This should
lead us to focus on the reasons for authorization in the operational environment.
One can pose the question of the admissibility and significance of the
acts in which the Security Council takes a clear position in favor of the
operation already initiated by the regional organization, without its previous
authorization. In these situations, the Security Council acknowledges, understands
or tolerates what has already happened and then, albeit implicitly,
determines the actual existence of the conditions in the context of the operation
in question, thus bringing it back within the UN system established by
the Charter
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