Development of secondary sexual characters in the seabob shrimp Xiphopenaeus kroyeri (Heller 1862) (Crustacea,Decapoda, Penaeidae): a scanning electron microscope study

The development of secondary sexual characters, the petasma, and thelycum growth were studied in Xiphopenaeus kroyeri. In adult females, the thelycum is a single plate and its anterolateral portion is characterized by a reduced hood. The aperture resembles a transverse ridge. In immature stages, the ridge has a space between the plates, which becomes narrower as it reaches the end of development. The female gonopore is ‘comma’ shaped. In adult males, the endopods of the petasma are linked at the dorsomedial margin by a large quantity of cincinnuli. In juveniles, cincinnuli gradually increase in number until they join both endopods. At the end of development the petasma is T-shaped. The male gonopore is C-shaped. The relative growth of the petasma total length versus juvenile body length showed a highly positive allometry, whereas in adults the growth was isometric. For the relationship carapace length versus thelycum width, the juvenile phase of females is characterized by an isometry and the adult phase by a negative allometry.     

Forward head posture is associated with pressure pain threshold and neck pain duration in university students with subclinical neck pain

Abstract

Objective: The aims of this study are to investigate the association between: (i) forward head posture (FHP) and pressure pain thresholds (PPTs); (ii) FHP and maladaptive cognitive processes; and (iii) FHP and neck pain characteristics in university students with subclinical neck pain.

Materials/methods: A total of 140 university students, 90 asymptomatic and 50 with subclinical neck pain, entered the study. Demographic data, anthropometric data, FHP, and PPTs were collected for both groups. In addition, pain characteristics, pain catastrophizing, and fear of movement were assessed for participants with neck pain. FHP was characterized by the angle between C7, the tragus of the ear, and the horizontal line. Correlation analysis and multivariate regression analysis were conducted.

Results: Participants with subclinical neck pain showed significantly lower PPTs than participants without neck pain (p?<?.05), but similar FHP (p?>?.05). No significant association was found between FHP and PPTs in the asymptomatic group. In the group of participants with subclinical neck pain, PPTs at the right trapezius and neck pain duration explained 19% of the variance of FHP (R²?=?0.23; adjusted R²?=?0.19; p?<?.05).

Conclusion: This study suggests that FHP is not associated with PPTs in asymptomatic university students. In university students with subclinical neck pain, increased FHP was associated with right trapezius hypoalgesia and with neck pain of shorter duration. These findings are in contrast with current assumptions on the association between neck pain and FHP.     

Health applications of bioactive compounds from marine microalgae

Marine microalgae and cyanobacteria are very rich in several chemical compounds and, therefore, they may be used in several biological applications related with health benefits, among others. This review brings the research up-to-date on the bioactive compounds produced by marine unicellular algae, directly or indirectly related to human health. It covers and goes through the most studied applications of substances such as PUFA, sterols, proteins and enzymes, vitamins and pigments, in areas so diverse as human and animal nutrition, therapeutics, and aquaculture. The great potential of marine microalgae and the biocoumpounds they produce are discussed in this review.     

Ultrasonication of insulin-loaded microgel particles produced by internal gelation: Impact on particle's size and insulin bioactivity

Alginate-dextran sulfate (ADS) microgel has been used to protect insulin from gastrointestinal attack and as a carrier to promote insulin permeation through intestinal epithelium. The throughput of ADS submicron particles generation by emulsification/internal gelation is limited by its wide size distribution.     

UCP2 and ANT differently modulate proton-leak in brain mitochondria of long-term hyperglycemic and recurrent hypoglycemic rats

A growing body of evidence suggests that mitochondrial proton-leak functions as a regulator of reactive oxygen species production and its modulation may limit oxidative injury to tissues. The main purpose of this work was to characterize the proton-leak of brain cortical mitochondria from long-term hyperglycemic and insulin-induced recurrent hypoglycemic rats through the modulation of the uncoupling protein 2 (UCP2) and adenine nucleotide translocator (ANT). Streptozotocin-induced diabetic rats were treated subcutaneously with twice-daily insulin injections during 2 weeks to induce the hypoglycemic episodes. No differences in the basal proton-leak, UCP2 and ANT protein levels were observed between the experimental groups. Mitochondria from recurrent hypoglycemic rats presented a decrease in proton-leak in the presence of GDP, a specific UCP2 inhibitor, while an increase in proton-leak was observed in the presence of linoleic acid, a proton-leak activator, this effect being reverted by the simultaneous addition of GDP. Mitochondria from long-term hyperglycemic rats showed an enhanced susceptibility to ANT modulation as demonstrated by the complete inhibition of basal and linoleic acid-induced proton-leak caused by the ANT specific inhibitor carboxyatractyloside. Our results show that recurrent-hypoglycemia renders mitochondria more susceptible to UCPs modulation while the proton-leak of long-term hyperglycemic rats is mainly modulated by ANT, which suggest that brain cortical mitochondria have distinct adaptation mechanisms in face of different metabolic insults.     

Bivariate and Multivariate Analyses of the Influence of Blood Variables of Patients Submitted to Roux-en-Y Gastric Bypass on the Stability of Erythrocyte Membrane against the Chaotropic Action of Ethanol

The stability of the erythrocyte membrane, which is essential for the maintenance of cell functions, occurs in a critical region of fluidity, which depends largely on its composition and the composition and characteristics of the medium. As the composition of the erythrocyte membrane is influenced by several blood variables, the stability of the erythrocyte membrane must have relations with them. The present study aimed to evaluate, by bivariate and multivariate statistical analyses, the correlations and causal relationships between hematologic and biochemical variables and the stability of the erythrocyte membrane against the chaotropic action of ethanol. The validity of this type of analysis depends on the homogeneity of the population and on the variability of the studied parameters, conditions that can be filled by patients who undergo bariatric surgery by the technique of Roux-en-Y gastric bypass since they will suffer feeding restrictions that have great impact on their blood composition. Pathway analysis revealed that an increase in hemoglobin leads to decreased stability of the cell, probably through a process mediated by an increase in mean corpuscular volume. Furthermore, an increase in the mean corpuscular hemoglobin (MCH) leads to an increase in erythrocyte membrane stability, probably because higher values of MCH are associated with smaller quantities of red blood cells and a larger contact area between the cell membrane and ethanol present in the medium.     

Participation of the Cytoskeletal and Lysosomal Compartments in Campylobacter jejuni Invasion of Caco-2 cells, the Cellular Response by Morphometric Analysis and the Presence of Cytokine and Chemokine Transcripts

This study aimed to evaluate the participation of actin and tubulin in the process of internalisation, the interaction of bacterial phagosomes with lysosomes, the morphometric changes and the expression of inflammatory cytokines in Caco-2 cells infected with Campylobacter jejuni. Both actin and tubulin participated in the process of internalisation. Inside the cells, lysosomes fuse with phagosomes, which may lead to bacterial death because after 2 h, the bacteria were not detected by Transmission electron microscopy (TEM). There is increased expression of TGF-β3 during the early stages, and IL-8 was expressed after 60 min p.i. This work showed that C. jejuni invades and causes major morphometric changes in epithelial cells. In response, the cells increase their expression of cytokines that can lead to inflammation. The mechanisms of invasion are dependent on actin and tubulin, and once internalised, lysosomes fuse with phagosomes.     

The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.