Synthesis of oxidative metabolites of CRA13 and their analogs: Identification of CRA13 active metabolites and analogs thereof with selective CB2R affinity

CRA13; a peripheral dual CB₁R/CB₂R agonist with clinically proven analgesic properties, infiltrates into CNS producing adverse effects due to central CB₁R agonism. Such adverse effects might be circumvented by less lipophilic compounds with attenuated CB₁R affinity. Metabolism produces less lipophilic metabolites that might be active metabolites. Some CRA13 oxidative metabolites and their analogues were synthesized as less lipophilic CRA13 analogues. Probing their CB₁R and CB₂R activity revealed the alcohol metabolite 8c as a more potent and more effective CB₂R ligand with attenuated CB₁R affinity relative to CRA13. Also, the alcohol analogue 8b and methyl ester 12a possessed enhanced CB₂R affinity and reduced CB₁R affinity. The CB₂R binding affinity of alcohol analogue 8b was similar to CRA13 while that of methyl ester 12a was more potent. In silico study provided insights into the possible molecular interactions that might explain the difference in the elicited biological activity of these compounds.     

APC Inhibits Ligand-Independent Wnt Signaling by the Clathrin Endocytic Pathway

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Synthesis and biological activity of fluoroquinolone-pyrrolo[2,1-c][1,4]benzodiazepine conjugates

Fluoroquinolones have been synthesized and linked to DC-81 at C8 position through different alkyl chain spacers. These PBD conjugates have exhibited good DNA binding affinity, and a representative compound shows promising in vitro anticancer activity.     

Correction to: Managing biological invasions: the cost of inaction

Biological Invasions -     

Selenium as an adjuvant for modification of radiation response

Ionizing radiation plays a central role in several medical and industrial purposes. In spite of the beneficial effects of ionizing radiation, there are some concerns related to accidental exposure that could pose a threat to the lives of exposed people. This issue is also very critical for triage of injured people in a possible terror event or nuclear disaster. The most common side effects of ionizing radiation are experienced in cancer patients who had undergone radiotherapy. For complete eradication of tumors, there is a need for high doses of ionizing radiation. However, these high doses lead to severe toxicities in adjacent organs. Management of normal tissue toxicity may be achieved via modulation of radiation responses in both normal and malignant cells. It has been suggested that treatment of patients with some adjuvant agents may be useful for amelioration of radiation toxicity or sensitization of tumor cells. However, there are always some concerns for possible severe toxicities and protection of tumor cells, which in turn affect radiotherapy outcomes. Selenium is a trace element in the body that has shown potent antioxidant and radioprotective effects for many years. Selenium can potently stimulate antioxidant defense of cells, especially via upregulation of glutathione (GSH) level and glutathione peroxidase activity. Some studies in recent years have shown that selenium is able to mitigate radiation toxicity when administered after exposure. These studies suggest that selenium may be a useful radiomitigator for an accidental radiation event. Molecular and cellular studies have revealed that selenium protects different normal cells against radiation, while it may sensitize tumor cells. These differential effects of selenium have also been revealed in some clinical studies. In the present study, we aimed to review the radiomitigative and radioprotective effects of selenium on normal cells/tissues, as well as its radiosensitive effect on cancer cells.     

Evidence for the mechanism of the irreversible inhibition of oestrone sulphatase (ES) by aminosulphonate based compounds

In our search for the mechanism of the enzyme oestrone sulphatase (ES) we have synthesised and evaluated a number of compounds that were predicted to possess some inhibitory activity. Some of these compounds were indeed found to be inhibitors of ES, whilst other compounds were not. From a consideration of the structure–activity relationship (SAR) of the inhibitors and non-inhibitors of this enzyme, we discovered a factor which we now believe is the main inhibitory moiety within the aminosulphonated inhibitors. We therefore report the results of our study into a series of phenyl and alkyl sulphamated compounds as inhibitors of ES. The results of the study show that the substituted phenyl sulphamates are potent inhibitors, whereas the alkyl compounds are, in general, non-inhibitors. Using the results of our SAR study, we postulate the probable mechanism for the irreversible and reversible inhibition of ES, and rationalise the role of the different physicochemical factors in the inhibition of this crucial enzyme.     

Neuroadaptations in the Striatal Proteome of the Rat Following Prolonged Excessive Sucrose Intake

Obesity is a contemporary health problem of rapidly increasing prevalence. One possible cause of obesity is loss of control over consumption of highly palatable foodstuffs, perhaps mirroring the processes involved in drug addiction. Accordingly, the striatum may be a key neural substrate involved in both food and drug craving. We hypothesised here that prolonged exposure to 10 % sucrose solution might cause neuroadaptations in the striatum that are analogous to those previously reported following prolonged exposure to alcohol or recreational drugs. Male Wistar rats were given constant access to 10 % sucrose solution (in addition to normal lab chow and tap water) for 8 months and were compared with control rats receiving no sucrose access. Rats in the sucrose group typically drank more than 100 ml of sucrose solution per day and showed 13 % greater body weight than controls at the end of the 8 months. Striatal dopamine (DA) concentrations were decreased in the sucrose group rats relative to controls. Differential expression of 18 proteins was identified in the striatum of the sucrose group rats relative to controls. Down regulated proteins included pyridoxal phosphate phosphatase, involved in DA synthesis, and glutathione transferase, involved in free radical scavenging. Up regulated proteins included prolactin (which is under negative regulation by DA) and adipose differentiation-related protein, involved in fat synthesis. We hypothesise that DA-related neuroadaptations in the striatum caused by prolonged sucrose intake may partly drive compulsive intake and seeking of high palatability foodstuffs, in a similar way to that observed with drug and alcohol addictions.     

Identification of two forms of an endogenous murine retroviral env gene linked to the Rmcf locus.

The Rmcf gene restricts the replication of recombinant murine mink cell focus-inducing (MCF) viruses in cell cultures derived from mice carrying the resistance allele (Rmcfr) and may play a role in resistance to retrovirus-induced leukemias in vivo. We have characterized the endogenous gp70 expressed by Rmcfr and Rmcfs mice with a panel of type-specific monoclonal antibodies which discriminate xenotropic and MCF gp70. Embryo and tail skin cultures derived from Rmcfr mice (DBA/2 and CBA/N) expressed gp70 bearing a determinant unique to MCF viruses, whereas cultures from Rmcfs mice expressed either no detectable gp70 (NFS/N and IRW) or a gp70 serologically related to a subgroup of xenotropic viruses (C57BL/6, CBA/J, and A/WySn). Studies of progeny embryos derived from a (C57BL/6 X DBA/2) X C57BL/6 backcross established that the Rmcf resistance allele was linked to the expression of the MCF gp70 and that the gene encoding the xenotropic gp70 expressed by C57BL/6 Rmcfs mice was allelic with the MCF gp70 from Rmcfr mice. These data indicate that the Rmcf locus contains an endogenous gp70 gene having two allelic forms, one of which inhibits exogenous MCF infection in vitro by a mechanism of viral interference.     

Countrywide Survey for MERS-Coronavirus Antibodies in Dromedaries and Humans in Pakistan

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a zoonotic pathogen capable of causing severe respiratory disease in humans. Although dromedary camels are considered as a major reservoir host, the MERS-CoV infection dynamics in camels are not fully understood. Through surveillance in Pakistan, nasal (n = 776) and serum (n = 1050)samples were collected from camels between November 2015 and February 2018. Samples were collected from animal markets, free-roaming herds and abattoirs. An in-house ELISA was developed to detect IgG against MERS-CoV. A total of 794 camels were found seropositive for MERS-CoV. Prevalence increased with the age and the highest seroprevalence was recorded in camels aged [ 10 years (81.37%) followed by those aged 3.1–10 years (78.65%) and B 3 years (58.19%).Higher prevalence was observed in female (78.13%) as compared to male (70.70%). Of the camel nasal swabs, 22 were found to be positive by RT-qPCR though with high Ct values. Moreover, 2,409 human serum samples were also collected from four provinces of Pakistan during 2016–2017. Among the sampled population, 840 humans were camel herders.Although we found a high rate of MERS-CoV antibody positive dromedaries (75.62%) in Pakistan, no neutralizing antibodies were detected in humans with and without contact to camels.