Can short-term fasting protect against doxorubicin-induced cardiotoxicity?

Doxorubicin(Dox) is one of the most effective chemotherapeutic agents used in the treatment of several types of cancer. However the use is limited by cardiotoxicity. Despite extensive investigation into the mechanisms of toxicity and preventative strategies, Dox-induced cardiotoxicity still remains a major cause of morbidity and mortality in cancer survivors. Thus, continued research into preventative strategies is vital. Short-term fasting has proven to be cardioprotective against a variety of insults. Despite the potential, only a few studies have been conducted investigating its ability to prevent Dox-induced cardiotoxicity. However, all show proof-of-principle that short-term fasting is cardioprotective against Dox. Fasting affects a plethora of cellular processes making it difficult to discern the mechanism(s) translating fasting to cardioprotection, but may involve suppression of insulin and insulin-like growth factor-1 signaling with stimulated autophagy. It is likely that additional mechanisms also contribute. Importantly, the literature suggests that fasting may enhance the antitumor activity of Dox. Thus, fasting is a regimen that warrants further investigation as a potential strategy to prevent Dox-induced cardiotoxicity. Future research should aim to determine the optimal regimen of fasting, confirmation that this regimen does not interfere with the antitumor properties of Dox, as well as the underlying mechanisms exerting the cardioprotective effects.     

Effects of acute doxorubicin treatment on hepatic proteome lysine acetylation status and the apoptotic environment

AIM: To determine if doxorubicin(Dox) alters hepatic proteome acetylation status and if acetylation status was associated with an apoptotic environment. METHODS: Doxorubicin(20 mg/kg; Sigma, Saint Louis, MO; n = 8) or NaCl(0.9%; n = 7) was administered as an intraperitoneal injection to male F344 rats, 6-wk of age. Once animals were treated with Dox or saline, all animals were fasted until sacrifice 24 h later. RESULTS: Dox treatment decreased proteome lysine acetylation likely due to a decrease in histone acetyltransferase activity. Proteome deacetylation may likely not be associated with a proapoptotic environment. Dox did not increase caspase-9,-8, or-3 activation nor poly(adenosine diphosphate-ribose) polymerase-1 cleavage. Dox did stimulate caspase-12 activation, however, it likely did not play a role in apoptosis induction. CONCLUSION: Early effects of Dox involve hepatic proteome lysine deacetylation and caspase-12 activa-tion under these experimental conditions.     

Vulnerability of birds to contaminated water sources in the Karoo region of South Africa

The Karoo is a unique region in South Africa in terms of its ecological processes and endemic species. Large areas are needed to maintain viable populations of nomadic birds that follow erratic rainfall events and subsequent food and nesting resources, as well as ephemeral standing water. Whereas many species are adapted to arid conditions, our trait-based analysis found that an unusually large percentage (almost 45%) of 315 bird species in the semi-arid Karoo region rely on water to some degree. Indeed, some birds may have benefited from human activities to date, such as through the provision of water for livestock. However, this reliance on water makes birds vulnerable to changes in water quality stemming from various industrial developments. Given the large areas of the Karoo under consideration for concessions, the most noteworthy of these is hydraulic fracturing for shale gas, which results in a large quantity of waste water (‘produced water’) that contains a wide variety of chemicals, including petroleum byproducts. Given the negative impacts of secondary waste water on wildlife in other parts of the world where shale-gas exploration is being undertaken, careful attention must be given to preventing access to such produced water by an estimated 60 to 141 species of birds that make use of the water in the Karoo.     

Population structure of the Japanese eel, Anguilla japonica

Mitochondrial DNA (mtDNA) sequences that include (a) a part of the cytochrome b gene, (b) two tRNA genes, and (c) a part of the noncoding D-loop region of 31 Anguilla japonica (Japanese eel) and 1 A. marmorata collected from Taiwan, Japan, and mainland China were determined to evaluate the population structure of Japanese eel. Among 30 genotypes identified from the 31 Japanese eel mtDNAs sequenced, there are 58 variable sites, predominantly clustered at the D-loop region. The phylogenetic tree constructed by the unweighted pair-group method with arithmetic mean shows neither significant genealogical branches nor geographic clusters. Furthermore, the sequence-statistics test reveals little, if any, significant genetic differentiation. These results indicate that the 31 Japanese eels might come from a single population. Analysis of sequence variation in mtDNA by using the relationship between the number of segregating sites and the average number of nucleotide differences under the neutral mutation hypothesis reveals that neutral mutation acts as a major factor influencing the evolutionary divergence of the Japanese eel mitochondrial genome sequenced, especially in the noncoding region.      

Molecular evolution of P transposable elements in the genus Drosophila. I. The saltans and willistoni species groups

A phylogenetic survey using the polymerase chain reaction (PCR) has identified four major P element subfamilies in the saltans and willistoni species groups of Drosophila. One subfamily, containing about half of the sequences studied, consists of elements that are very similar to the canonical (and active) P element from D. melanogaster. Within this subfamily, nucleotide sequence differentiation among different copies from the same species and among elements from different species is relatively low. This observation suggests that the canonical elements are relatively recent additions to the genome or, less likely, are evolving slowly relative to the other subfamilies. Elements belonging to the three noncanonical lineages are distinct from the canonical elements and from one another. Furthermore, there is considerably more sequence variation, on the average, within the noncanonical subfamilies compared to the canonical elements. Horizontal transfer and the coexistence of multiple, independently evolving element subfamilies in the same genome may explain the distribution of P elements in the saltans and willistoni species groups. Such explanations are not mutually exclusive, and each may be involved to varying degrees in the maintenance of P elements in natural populations of Drosophila.      

MMG and EMG responses of the superficial quadriceps femoris muscles.

Eighteen adults performed isometric muscle actions of the leg extensors at 25, 50, 75, and 100% maximal voluntary contraction (%MVC) at leg flexion angles of 25, 50, and 75 degrees. The results indicated that isometric torque production increased as leg flexion angle increased (75 degrees > 50 degrees > 25 degrees). For each muscle tested (rectus femoris, vastus lateralis, and vastus medialis), the EMG amplitude increased up to 100%MVC at each leg flexion angle (25, 50, and 75 degrees). The MMG amplitude for each muscle, however, increased up to 100%MVC at 25 and 50 degrees of leg flexion, but plateaued from 75 to 100%MVC at 75 degrees of leg flexion. We hypothesize that the varied patterns for the MMG amplitude-isometric torque relationships were due to leg flexion angle differences in: (1) muscle stiffness, (2) intramuscular fluid pressure, or (3) motor unit firing frequency.     

Habitat variables associated with encounters of Hottentot Buttonquail Turnix hottentottus during flush surveys across the Fynbos biome

The Hottentot Buttonquail Turnix hottentotus is an endangered terrestrial turnicid and is endemic to the Fynbos biome, South Africa. Due to its secretive nature and apparent rarity almost nothing is known about the species, but its range has been subject to anthropogenic modification, invasion by alien plant species and is vulnerable to climate change. To model covariates associated with the presence of Hottentot Buttonquail we undertook flush surveys across the Fynbos biome, covering 275 km. Habitat variables at encounter sites were recorded in vegetation plots, as well as locations without encounters. There was a critical number of observers needed during a flush survey in order to account for buttonquail presence, with no encounters with less than five participants. After accounting for this, we found probability of encounters decreased with increasing time-since-fire. Probability of encounters were also negatively associated with increasing percentage grass and other vegetation cover. We also found no association between percentage cover of Restionaceae plants and encounter probability, considered previously to be the best indicator of Hottentot Buttonquail presence. This information will be of use to those interested in managing habitat for this species and should inform future conservation efforts.     

Tono Reservoir fishery contribution to poverty reduction among fishers in northern Ghana

Fishery characteristics and livelihood status of fishers at Tono Reservoir, Ghana, were investigated between January 2015 and June 2016. Data on fisher demography, fishing gears, fishing methods, perceptions of the state of fish stocks, management practices, income and consumption of fishers were obtained through structured interviews. Censuses of fishers and fishing gears were conducted through direct observation and counts. The population of fishers was 950 and the majority (74%) of the sampled respondents fell within the ages of 24–41 years. Gillnet, cast net, trap and hook and line were the four main gears utilised. Illegal methods of fishing observed included the use of mosquito nets (nets with mesh <1.0 cm) and the use of brewer’s waste (pito mash) as bait. Brycinus nurse, Synodontis spp., Parailia spiniserrata and Chrysichthys spp. were perceived to have disappeared from the reservoir. The fishers were unaware of the existence of any fisheries regulations, hence there was no adherence to management practices. Their daily income was derived mainly from fishing. The incidence of poverty among fishers was low (8%). The Tono Reservoir has a great potential for supporting livelihood if it is properly managed.     

Granulocyte-CSF induced inflammation-associated cardiac thrombosis in iron loading mouse heart and can be attenuated by statin therapy

Background  

Granulocyte colony-stimulating factor (G-CSF), a hematopoietic cytokine, was recently used to treat patients of acute myocardial infarction with beneficial effect. However, controversy exists as some patients developed re-stenosis and worsened condition post G-CSF delivery. This study presents a new disease model to study G-CSF induced cardiac thrombosis and delineate its possible mechanism. We used iron loading to mimic condition of chronic cardiac dysfunction and apply G-CSF to mice to test our hypothesis.