Evidence of functional deficits at the single muscle fiber level in experimentally-induced renal insufficiency

Chronic kidney disease patients present with metabolic and functional muscle abnormalities, called uremic myopathy, whose mechanisms have not yet been fully elucidated. We investigated whether chronic renal insufficiency (CRI) affects skeletal muscle contractile properties at the cellular level. CRI was induced surgically in New Zealand rabbits (UREM), with sham-operation for controls (CON), and samples were collected at 3 months post-surgery, following euthanasia. All protocols had University Ethics approval following national and European guidelines. Sample treatments and evaluations were blinded. Maximal isometric force was assessed in 382 permeabilized psoas fibers (CON, n = 142, UREM, n = 240) initially at pH7, 10 °C (‘standard’ conditions), in subsets of fibers in acidic conditions (pH6.2, 10 °C) but also at near physiological temperature (pH7, 30 °C and pH6.2, 30 °C). CRI resulted in significant smaller average cross sectional areas (CSAs) by ∼11% for UREM muscle fibers (vs CON, P < 0.01). At standard conditions, UREM fibers produced lower absolute and specific forces (i.e. normalized force per fiber CSA) (vs CON, P < 0.01); force increased in 30 °C for both groups (P < 0.01), but the disparity between UREM and CON remained significant. Acidosis significantly reduced force (vs pH7, 10 °C P < 0.01), similarly in both groups (in UREM by −48% and in CON by −43%, P > 0.05). For the first time, we give evidence that CRI can induce significant impairments in single psoas muscle fibers force generation, only partly explained by fiber atrophy, thus affecting muscle mechanics at the cellular level.     

Carbon isotope discrimination function analysis and drought tolerance of stylo species grown under rain-fed environment

Limited germplasm and narrow genetic base in the past has hinders wider applicability of Stylosanthes in India. However, build up in Stylosanthes germplasm in recent years provided an opportunity to evaluate and use them under different agro-ecological situations preferably targeting drought tolerance. Rate reducing resistance (RRR) allo-tetraploid lines of S. scabra and diploid S. seabrana, a newly introduced species, observed well suited in hard and cracking soils under complete rainfed condition. Genotypes of S. scabra were more tolerant to drought over lines of other species as evidenced by high leaf thickness, more proline accumulation, contents of malondialdehyde (MDA), sugars, starch and chlorophyll and low carbon isotope discrimination (CID) values. Both in control and stress conditions, a positive relationship (r = 0.465 and 0.328) was observed between specific leaf area (SLA) and CID. Earlier reports have emphasized measurement of CID as an indirect way of measuring the transpiration efficiency (TE) in Stylosanthes (Thumma et al. Aust J Agr Res 49:1039–1045, 1998). The negative relationship observed between TE and CID suggested low CID bearing lines would have high TE, useful traits to select lines growing better in dry environments. Thus, selected lines having low CID provided better scope for the introduction of this important range legume for semi- arid regions of India.     

The cornerstone of integrating circulating tumor DNA into cancer management

Recent circulating tumor DNA (ctDNA) research has demonstrated its potential as a non-invasive biomarker for cancer. However, the deployment of ctDNA assays in routine clinical practice remains challenging owing to variability in analytical approaches and the assessment of clinical significance. A well-developed, analytically valid ctDNA assay is a prerequisite for integrating ctDNA into cancer management, and an appropriate analytical technology is crucial for the development of a ctDNA assay. Other determinants including pre-analytical procedures, test validation, internal quality control (IQC), and continual proficiency testing (PT) are also important for the accuracy of ctDNA assays. In the present review, we will focus on the most widely used ctDNA detection technologies and the key quality management measures used to assure the accuracy of ctDNA assays. The aim of this review is to provide useful information for technology selection during ctDNA assay development and assure a reliable test result in clinical practice.     

Postcrania and the specific mate recognition system

The Recognition Concept of Species is examined for its potential usefulness in discriminating speciation events in the hominid fossil record. Controversies over species-specific characteristics amongHomo erectus and archaicHomo sapiens have centred on traits of the skull, largely because this element is most commonly preserved. Modern humans have an intuitive knowledge of their own Specific Mate Recognition System (SMRS), and therefore have the opportunity to compare their own SMRS to that of fossil hominids and the extent pongids. Such comparison suggests that our own skeletal SMRS may depend less on features of the skull than on the morphology of the postcranial anatomy. We propose that these components be further examined in this regard. We tentatively conclude that examination of the Recognition Concept of Species indicates that from lateHomo erectus onwards, the same SMRS has been shared in common by all hominids, including modernHomo sapiens. This suggests that, following the SMRS criterion, none of these forms can be categorized as separate species.     

Fish allergy in patients with parvalbumin-specific immunoglobulin E depends on parvalbumin content rather than molecular differences in the protein among fish species

Allergenic characteristics of purified parvalbumins from different fish species have not been thoroughly investigated. We revealed that purified parvalbumins from nine different fish species have identical IgE-reactivities and high cross-reactivities. We also showed that fish allergenicity is associated with the parvalbumin content of the fish species, rather than species-specific differences in the molecular characteristics of the individual parvalbumin proteins.     

Toxocara canis and the allergic process

The protective effect of infectious agents against allergic reactions has been thoroughly investigated. Current studies have demonstrated the ability of some helminths to modulate the immune response of infected hosts. The objective of the present study was to investigate the relationship between Toxocara canis infection and the development of an allergic response in mice immunised with ovalbumin (OVA). We determined the total and differential blood and bronchoalveolar lavage fluid cells using BALB/c mice as a model. To this end, the levels of interleukin (IL)-4, IL-5 and IL-10 and anti-OVA-IgE were measured using an ELISA. The inflammatory process in the lungs was observed using histology slides stained with haematoxylin and eosin. The results showed an increase in the total number of leukocytes and eosinophils in the blood of infected and immunised animals at 18 days after infection. We observed a slight lymphocytic inflammatory infiltrate in the portal space in all infected mice. Anti-OVA-IgE levels were detected in smaller proportions in the plasma of immunised and infected mice compared with mice that were only infected. Therefore, we concluded that T. canis potentiates inflammation in the lungs in response to OVA, although anti-OVA-IgE levels suggest a potential reduction of the inflammatory process through this mechanism.     

Traits and growth of liana regeneration in primary and secondary forests of Central Amazonia

Question: Do traits of liana regeneration differ among secondary forest types of varying land‐use history and primary forest? Location: Eighty kilometers north of Manaus, Brazil. Methods: We compared plant functional traits and growth rates of liana regeneration (<1.7‐m length) among two secondary forest types and primary forest. Secondary forest types were: Vismia (on land formerly clear‐cut, used for pasture and intensively burned) and Cecropia (no pasture usage or intensive fires after clear‐cut). Results: A principal components analysis indicated that most of the primary forest species exhibited a similar habit and were characterized by short shoots and small, round leaves with low specific leaf area, whereas secondary forest species had a broad range of trait values. At the plot level, primary and secondary forest communities were separated mainly by plant length and leaf size. Plant size varied more within secondary than within primary forest plots. The two secondary forest types could not be separated based on the traits of liana regeneration. Relative growth rate (RGR) did not correlate significantly with any measured plant trait, except for a negative relation to initial length. RGR increased with decreasing canopy cover and was highest in Vismia forest plots. Conclusion: Plant functional traits of liana regeneration were more similar in the primary forest and differed substantially from secondary forests, yet canopy cover only partly explained the observed differences.