A coupled mathematical model between bone remodeling and tumors: a study of different scenarios using Komarova’s model

This paper aims to construct a general framework of coupling tumor–bone remodeling processes in order to produce plausible outcomes of the effects of tumors on the number of osteoclasts, osteoblasts, and the frequency of the bone turnover cycle. In this document, Komarova’s model has been extended to include the effect of tumors on the bone remodeling processes. Thus, we explored three alternatives for coupling tumor presence into Komarova’s model: first, using a “damage” parameter that depends on the tumor cell concentration. A second model follows the original structure of Komarova, including the tumor presence in those equations powered up to a new parameter, called the paracrine effect of the tumor on osteoclasts and osteoblasts; the last model is replicated from Ayati and collaborators in which the impact of the tumor is included into the paracrine parameters. Through the models, we studied their stability and considered some examples that can reproduce the tumor effects seen in clinic and experimentally. Therefore, this paper has three parts: the exposition of the three models, the results and discussion (where we explore some aspects and examples of the solution of the models), and the conclusion.

     

Creatine nanoliposome reverts the HPA-induced damage in complex II–III activity of the rats’ cerebral cortex

Molecular Biology Reports - Phenylketonuria (PKU) is a metabolic disorder accumulating phenylalanine (Phe) and its metabolites in plasma and tissues of the patients. Regardless of the mechanisms,...     

Clerodane diterpenes from Baccharis sagittalis: insect antifeedant activity

Two clerodane-type diterpene glycosides esters, which were studied as peracetyl derivatives, together with the known diterpene marrubiagenine, were isolated from the aerial part of Baccharis sagittalis (Less). Their structures were established by spectroscopic methods. Antifeedant activity toward Tenebrio molitor larvae of the isolated compounds along with six other diterpenes was evaluated and some structure-antifeedant bioactivity relationships are reported.     

Protein Interaction Screening for the Ankyrin Repeats and Suppressor of Cytokine Signaling (SOCS) Box (ASB) Family Identify Asb11 as a Novel Endoplasmic Reticulum Resident Ubiquitin Ligase

The ankyrin and SOCS (suppressor of cytokine signaling) box (ASB) family of proteins function as the substrate recognition subunit in a subset of Elongin-Cullin-SOCS (ECS) E3 ubiquitin ligases. Despite counting 18 members in humans, the identity of the physiological targets of the Asb proteins remains largely unexplored. To increase our understanding of the function of ASB proteins, we conducted a family-wide SILAC (stable isotope labeling by amino acids in cell culture)-based protein/protein interaction analysis. This investigation led to the identification of novel as well as known ASB-associated proteins like Cullin 5 and Elongins B/C. We observed that several proteins can be bound by more than one Asb protein. The additional exploration of this phenomenon demonstrated that ASB-Cullin 5 complexes can oligomerize and provides evidence that Cullin 5 forms heterodimeric complexes with the Cullin 4a-DDB1 complex. We also demonstrated that ASB11 is a novel endoplasmic reticulum-associated ubiquitin ligase with the ability to interact and promote the ubiquitination of Ribophorin 1, an integral protein of the oligosaccharyltransferase (OST) glycosylation complex. Moreover, expression of ASB11 can increase Ribophorin 1 protein turnover in vivo. In summary, we provide a comprehensive protein/protein interaction data resource that can aid the biological and functional characterization of ASB ubiquitin ligases.     

Influence of fitness on the integrated neuroendocrine response to aerobic exercise until exhaustion

A group of trained and sedentary men performed an incremental graded exercise-test to exhaustion in order to assess the organic response of the two main stress-activated systems: the sympathetic nervous system with its endocrine component (the adrenal medulla), and the hypothalamic-pituitary-adrenal (HPA) axis. Maximal plasma concentrations of ACTH, cortisol and endogenous opioids (beta-endorphins) were obtained at the end of the exercise-test in the trained group. Thus ACTH increased from basal value of 21.25 +/- 2.5 pg/ml to 88.78 +/- 11.8 pg/ml at the end of the exercise (p<0.01); cortisol, from 16.56 microg/dl +/- 4.94 microg/dl to 23.80 +/- 4.57 microg/dl in min 15 of the recovery period (p<0.001); and beta-endorphin from 21.80 +/- 8.33 pmol/ml to 64.36 +/- 9.8 pmol/ml in min 3 of the recovery period (p<0.05). Catecholamine levels were increased from initial values at the end of the effort test in both control and trained groups. Control subjects exhibited a higher responsiveness compared to trained and showed superior intrinsic stimulation of the sympathetic nervous system. These results reveal a different response according to fitness in a physical stress situation.