Design,synthesis, in silico studies and in vitro evaluation of isatin-pyridine oximes hybrids as novel acetylcholinesterase reactivators

Organophosphorus poisoning caused by some pesticides and nerve agents is a life-threating condition that must be swiftly addressed to avoid casualties. Despite the availability of medical countermeasures, the clinically available compounds lack a broad spectrum, are not effective towards all organophosphorus toxins, and have poor pharmacokinetics properties to allow them crossing the blood-brain barrier, hampering cholinesterase reactivation at the central nervous system. In this work, we designed and synthesised novel isatin derivatives, linked to a pyridinium 4-oxime moiety by an alkyl chain with improved calculated properties, and tested their reactivation potency against paraoxon- and NEMP-inhibited acetylcholinesterase in comparison to the standard antidote pralidoxime. Our results showed that these compounds displayed comparable in vitro reactivation also pointed by the in silico studies, suggesting that they are promising compounds to tackle organophosphorus poisoning.     

c-Src kinase contributes on endothelial cells mechanotransduction in a heat shock protein 70-dependent turnover manner

Shear stress changes are associated with a repertory of signaling cascade modulating vascular phenotype. As shear stress-related tensional forces might be associated with pathophysiological susceptibility, a more comprehensive molecular map needs to be addressed. Thus, we subjected human umbilical vein endothelial cells (HUVECs) to a circuit of different tensional forces in vitro considering the following three groups: (a) physiological blood flow shear stress condition (named Normo), (b) a hypertensive blood flow shear stress (named Hyper), and (c) these hyper-stressed cells were returned to Normo condition (named Return). The samples were properly collected to allow different methodologies analysis. Our data showed a pivotal involvement of c-Src on driving the mechanotransduction cascade by modulating signaling related with adhesion, survival (PI3K/Akt) and proliferative phenotype. Moreover, c-Src seems to develop important role during extracellular matrix remodeling. Additionally, proteomic analysis showed strong involvement of heat shock protein 70 (HSP70) in the hypertensive-stressed cells; it being significantly decreased in return phenotype. This result prompted us to investigate 20S proteasome as an intracellular proteolytic alternative route to promote the turnover of those proteins. Surprisingly, our data reveled significant overexpression of sets of proteasome subunit α-type (PSMA) and β-type (PSMB) genes. In conjunction, our data showed c-Src as a pivotal protein to drive mechanotransduction in endothelial cells in a HSP70-dependent turnover scenario. Because shear patterns is associated with pathophysiological changes, such as atherosclerosis and hypertension, these results paved new road to understand the molecular mechanism on driving mechanotransduction in endothelial cells and, if drugable, these targets must be considered within pharmacological treatment optimization.     

Mononuclear phagocytes in the retina of developing rats

Mononuclear phagocytes were labeled with colloidal carbon injected into the circulation or stained with cytochemical techniques for the detection of marker enzymes in whole-mounted retinae of rats from birth to 10 days after birth. Positive cells were found apposed to or scattered among the blood vessels of the immature vascular network located just vitread to the developing retina. A few cells only had carbon distributed in the cytoplasm, but all retinae tested had positive cells. The enzymes located cytochemically in the phagocytes were non-specific esterase, acid phosphatase and endogenous peroxidase. When stained with aniline dyes, the phagocytes had a morphology similar to blood monocytes. Such cells were not found in the retina of adult rats. It is concluded that mononuclear phagocytes reside just vitread to the ganglion cell layer during the period of natural cell death in that layer. The phagocytes are probably associated with the removal of cell debris during the late period of retinal histogenesis.     

Methyl jasmonate changes the levels of rubisco and other leaf proteins in Ricinus communis

The effect of methyl jasmonate (MJ) on the water-soluble protein pattern of Ricinus communis leaves was analyzed. Several dynamic changes occurred after a period of 24 and 48h including six proteins (M_r 13,000, 15,000, 16,000, 27,000, 29,000 and 60,000) whose levels increased by 48h and seven others (M_r 11,000, 18,000, 20,000 30,000, 37,000, 40,000 and 58,000) whose levels decreased. Four proteins (M_r 24,000, 34,000, 64,000 and 66,000) were induced after 24h of treatment, but returned to control levels by 48h. On the other hand, the levels of three proteins (M_r 74,000, 84,000 and 88,000) decreased after 24h, but returned to control levels after 48h. One of the proteins that accumulated after 48 h had the 13 first residues sequenced. This polypeptide named MJRC-15, was identical to the C-terminal sequence of Rubisco-large chain polypeptide (position 337–350) from tobacco chloroplast. Western-blot analysis using polyclonal antibodies against Rubisco supports the hypothesis that MJRC-15 is a degradation product of Rubisco.     

Cytogenetic studies on gas station attendants.

Forty-nine gas station attendants employed to pump fuel and 24 controls were studied cytogenetically. This type of worker is occupationally exposed to fuel fumes and to automotive vehicle emissions. Chromosome analysis showed a significantly higher frequency of chromosome deletions among the gas station attendants than a control group. Taking into account the relationship between clastogenicity and increased cancer risk, we may consider these workers to form a risk group.     

Mononuclear phagocytes in the retina of developing rats

Summary Mononuclear phagocytes were labeled with colloidal carbon injected into the circulation or stained with cytochemical techniques for the detection of marker enzymes in whole-mounted retinae of rats from birth to 10 days after birth. Positive cells were found apposed to or scattered among the blood vessels of the immature vascular network located just vitread to the developing retina. A few cells only had carbon distributed in the cytoplasm, but all retinae tested had positive cells. The enzymes located cytochemically in the phagocytes were non-specific esterase, acid phosphatase and endogenous peroxidase. When stained with aniline dyes, the phagocytes had a morphology similar to blood monocytes. Such cells were not found in the retina of adult rats. It is concluded that mononuclear phagocytes reside just vitread to the ganglion cell layer during the period of natural cell death in that layer. The phagocytes are probably associated with the removal of cell debris during the late period of retinal histogenesis.