Standard Methods for Dissection of Varroa destructor Females

Varroa destructor (Anderson and Trueman) is known as a major pest of Apis mellifera L, especially in the Northern Hemisphere where its effects can be deleterious. As an obligate parasite, this mite relies entirely on its host to reproduce and complete its cycle. Studies focusing on isolated organs are needed to better comprehend this organism. To conduct such targeted molecular or physiological studies, the dissection of V. destructor mites is crucial as it allows the extraction of specific organs. Here, we propose a technical article showing detailed steps of females V. destructor dissection, illustrated with pictures and videos. These illustrated guidelines will represent a helpful tool to go further in V. destructor research.

Effect of Mucuna pruriens and Millettia pinnata (Fabaceae) minerals on some isolated organs of envenomated and treated Oryctolagus cuniculus

The general objective of this study was to evaluate the antivenom effect of minerals from two plants on some vital organs (heart, liver, kidneys and lungs) of rabbits. It was carried out with 36 rabbits (19 males and 17 females) divided into portions E1, E2 and E3. E1 consisted of 2 control lots (3 males and 3 females), and 1 experimental lot (2 males and 1 female). E2 comprised 7 batches of rabbits (2 males and 1 female). E3 consisted of 2 batches of 3 females. Naja nigricollis venom was injected for approximately 20-30 minutes to the animals in the experimental batch of E1, and to those in E2 and E3. Then, E2 and E3 were treated preventively and curatively with minerals, respectively. After the determination of their biochemical and hematological parameters, they were necropsied separately and then their organs were removed, weighed and their appearance was studied. The study revealed that the venom of Naja nigricollis was the cause of death of all the animals of the experimental batch of E1. On the other hand, the use of P2 and P3 as a preventive measure was able to save 1 out of 3 and 3 individuals respectively from the venom. As for P3 as a curative measure, it kept alive 2 out of 3 individuals against the venom. Thus, for the development of anti-venomous phytomedicine, it would be advisable to use the minerals from P3 (ash of Millettia pinnata). Keywords: Antivenomous, minerals, Millettia pinnata, Naja nigricollis, phytomedicine

COMPARATIVE ANATOMY AND HISTOCHEMISTRY OF FRUITS OF FOUR VARIETIES OF Hancornia speciosa GOMES (APOCYNACEAE)

Hancornia speciosa Gomes, known as mangaba or mangabeira, is a plant species of the family Apocynaceae with botanical varieties occurring in several regions of Brazil. The species is of considerable ecological and economic importance in the food, timber, latex and medicinal industries. Four different varieties of H. speciosa occur in Cerrado. Anatomical characteristics contribute to the taxonomic identification of plants, including those of isolated organs such as leaves, roots, stems, fruits and seeds. Thus, the present work investigated the anatomical characteristics and the location of the main classes of secondary metabolites of the fruits of H. speciosa var. pubescens, H. speciosa var. gardneri, H. speciosa var. speciosa and H. speciosa var. cuyabensis to assist in distinguishing the varieties. Fruits were collected, preserved and fixed following usual methods for anatomical and histochemical analyses. All varieties under study showed similarities in anatomical characteristics and in the distribution of metabolites in the fruits, with the exception of the anatomy of the exocarp, where the occurrence of trichomes differed among the varieties of H. speciosa.

Using experimental ex vivo models to develop COVID-19 pathogenetic therapy and complications prevention agents

COVID-19 is a disease characterized by damage to the lower respiratory tract, development of the acute respiratory distress syndrome, in severe cases — multiple organ failure, including acute heart failure and cardiomyopathy. This study aimed to evaluate the effectiveness of the developed COVID-19 pathogenetic therapy and complications prevention agents using the ex vivo isolated lung and heart models. Isolated organs of white rats were used for the research; the dynamics of functional indicators were analyzed. An amino acid-peptide complex (APC) from a thermally treated milk protein hydrolyzate was used as the experimental COVID-19 pathogenetic therapy and complications prevention agent. Introduction of the APC to the isolated cardiopulmonary complex perfusate slowed down development of pulmonary edema in the experimental group; the organ's weight was 1.5 times less than in the control group (p = 0.0158). We have also registered an airway resistance downtrend. APC supported contractile activity of the isolated myocardium suffering ischemia-reperfusion: the growth of the left ventricular end diastolic pressure was 34% smaller than that registered in the control group (p < 0.05). The APC's cardioprotective effect relies on the endothelium-dependent mechanisms. The ex vivo method is highly informative. It allows assessing reactivity of the isolated organs exposed to biologically active substances and determining the possibilities of compensating for functional changes.

The Plasma [Kynurenine]/[Tryptophan] Ratio and Indoleamine 2,3-Dioxygenase: Time for Appraisal

The plasma kynurenine to tryptophan ([Kyn]/[Trp]) ratio is frequently used to express or reflect the activity of the extrahepatic Trp-degrading enzyme indoleamine 2,3-dioxygenase (IDO). This ratio is increasingly used instead of measurement of IDO activity, which is often low or undetectable in immune and other cells under basal conditions, but is greatly enhanced after immune activation. The use of this ratio is valid in in vitro studies, eg, in cell cultures or isolated organs, but its ‘blanket’ use in in vivo situations is not, because of modulating factors, such as supply of nutrients; the presence of multiple cell types; complex structural and functional tissue arrangements; the extracellular matrix; and hormonal, cytokine, and paracrine interactions. Determinants other than IDO may therefore be involved in vivo. These are hepatic tryptophan 2,3-dioxygenase (TDO) activity and the flux of plasma-free Trp down the Kyn pathway. In addition, conditions leading to accumulation of Kyn, eg, inhibition of activities of Kyn monooxygenase and kynureninase, could lead to elevation of the aforementioned ratio. In this review, the origin of use of this ratio will be discussed, variations in extent of its elevation will be described, evidence against its indiscriminate use will be presented, and examining determinants other than IDO activity and their correlates will be proposed for future studies.