A conserved sequence immediately N-terminal to the Bateman domains in AMP-activated protein kinase gamma subunits is required for the interaction with the beta subunits

Mammalian AMP-activated protein kinase is a serine/threonine protein kinase that acts as a sensor of cellular energy status. AMP-activated protein kinase is a heterotrimer of three different subunits, i.e. alpha, beta, and gamma, with alpha being the catalytic subunit and beta and gamma having regulatory roles. Although several studies have defined different domains in alpha and beta involved in the interaction with the other subunits of the complex, little is known about the regions of the gamma subunits involved in these interactions. To study this, we have made sequential deletions from the N termini of the gamma subunit isoforms and studied the interactions with alpha and beta subunits, both by two-hybrid analysis and by co-immunoprecipitation. Our results suggest that a conserved region of 20-25 amino acids in gamma1, gamma2, and gamma3, immediately N-terminal to the Bateman domains, is required for the formation of a functional, active alphabetagamma complex. This region is required for the interaction with the beta subunits. The interaction between the alpha and gamma subunits does not require this region and occurs instead within the Bateman domains of the gamma subunit, although the alpha-gamma interaction does appear to stabilize the beta-gamma interaction. In addition, sequential deletions from the C termini of the gamma subunits indicate that deletion of any of the CBS (cystathionine beta-synthase) motifs prevents the formation of a functional complex with the alpha and beta subunits.     

Saccharomyces cerevisiae strain UFMG 905 protects against bacterial translocation, preserves gut barrier integrity and stimulates the immune system in a murine intestinal obstruction model

Probiotic is a preparation containing microorganisms that confers beneficial effect to the host. This work assessed whether oral treatment with viable or heat-killed yeast Saccharomyces cerevisiae strain UFMG 905 prevents bacterial translocation (BT), intestinal barrier integrity, and stimulates the immunity, in a murine intestinal obstruction (IO) model. Four groups of mice were used: mice undergoing only laparotomy (CTL), undergoing intestinal obstruction (IO) and undergoing intestinal obstruction after previous treatment with viable or heat-killed yeast. BT, determined as uptake of ^99mTc-E. coli in blood, mesenteric lymph nodes, liver, spleen and lungs, was significantly higher in IO group than in CTL group. Treatments with both yeasts reduced BT in blood and all organs investigated. The treatment with both yeasts also reduced intestinal permeability as determined by blood uptake of ^99mTc-DTPA. Immunological data demonstrated that both treatments were able to significantly increase IL-10 levels, but only viable yeast had the same effect on sIgA levels. Intestinal lesions were more severe in IO group when compared to CTL and yeasts groups. Concluding, both viable and heat-killed cells of yeast prevent BT, probably by immunomodulation and by maintaining gut barrier integrity. Only the stimulation of IgA production seems to depend on the yeast viability.     

The genomic ancestry of individuals from different geographical regions of Brazil is more uniform than expected

Based on pre-DNA racial/color methodology, clinical and pharmacological trials have traditionally considered the different geographical regions of Brazil as being very heterogeneous. We wished to ascertain how such diversity of regional color categories correlated with ancestry. Using a panel of 40 validated ancestry-informative insertion-deletion DNA polymorphisms we estimated individually the European, African and Amerindian ancestry components of 934 self-categorized White, Brown or Black Brazilians from the four most populous regions of the Country. We unraveled great ancestral diversity between and within the different regions. Especially, color categories in the northern part of Brazil diverged significantly in their ancestry proportions from their counterparts in the southern part of the Country, indicating that diverse regional semantics were being used in the self-classification as White, Brown or Black. To circumvent these regional subjective differences in color perception, we estimated the general ancestry proportions of each of the four regions in a form independent of color considerations. For that, we multiplied the proportions of a given ancestry in a given color category by the official census information about the proportion of that color category in the specific region, to arrive at a "total ancestry" estimate. Once such a calculation was performed, there emerged a much higher level of uniformity than previously expected. In all regions studied, the European ancestry was predominant, with proportions ranging from 60.6% in the Northeast to 77.7% in the South. We propose that the immigration of six million Europeans to Brazil in the 19th and 20th centuries--a phenomenon described and intended as the "whitening of Brazil"--is in large part responsible for dissipating previous ancestry dissimilarities that reflected region-specific population histories. These findings, of both clinical and sociological importance for Brazil, should also be relevant to other countries with ancestrally admixed populations.     

Fish biodiversity of Saint Peter and Saint Paulʼs Archipelago,Mid-Atlantic Ridge,Brazil: new records and a species database

Saint Peter and Saint Paul's Archipelago (SPSPA), one of the smallest and most isolated island groups in the world, is situated on the Mid-Atlantic Ridge, between Brazil and the African continent. SPSPA has low species richness and high endemism; nonetheless, the diversity of fishes from deep habitats (>30 m depth) had not been previously studied in detail. Several expeditions conducted between 2009 and 2018 explored the shallow and deep reefs of SPSPA using scuba, closed-circuit rebreathers, manned submersibles, baited remote underwater stereo-videos (stereo-BRUV) and fishing between 0 and 1050 m depth. These expeditions yielded 41 new records of fishes for SPSPA: 9 in open waters, 9 in shallow waters (0–30 m), 8 in mesophotic ecosystems (30–150 m) and 15 in deeper reefs (>150 m). Combined with literature records of adult pelagic, shallow and deep-reef species, as well as larvae, the database of the fish biodiversity for SPSPA currently comprises 225 species (169 recorded as adult fishes and 79 as larvae, with 23 species found in both stages). Most of them (112) are pelagic, 86 are reef-associated species and 27 are deep-water specialists. Species accumulation curves show that the number of fish species has not yet reached an asymptote. Whereas the number of species recorded in SPSPA is similar to that in other oceanic islands in the Atlantic Ocean, the proportion of shorefishes is relatively lower, and the endemism level is the third highest in the Atlantic. Twenty-nine species are listed as threatened with extinction. Observations confirm the paucity of top predators on shallow rocky reefs of the island, despite the presence of several pelagic shark species around SPSPA. Because all of the endemic species are reef associated, it is argued that the new marine-protected areas created by the Brazilian government do not ensure the protection and recovery of SPSPA's biodiversity because they allow exploitation of the most vulnerable species around the archipelago itself. This study suggests a ban on reef fish exploitation inside an area delimited by the 1000 m isobath around the islands (where all known endemics are concentrated) as the main conservation strategy to be included in the SPSPA management plan being prepared by the Brazilian government.     

Effects of double ligation of Stensen's duct on the rabbit parotid gland

Salivary gland duct ligation is an alternative to gland excision for treating sialorrhea or reducing salivary gland size prior to tumor excision. Duct ligation also is used as an approach to study salivary gland aging, regeneration, radiotherapy, sialolithiasis and sialadenitis. Reports conflict about the contribution of each salivary cell population to gland size reduction after ductal ligation. Certain cell populations, especially acini, reportedly undergo atrophy, apoptosis and proliferation during reduction of gland size. Acini also have been reported to de-differentiate into ducts. These contradictory results have been attributed to different animal or salivary gland models, or to methods of ligation. We report here a bilateral double ligature technique for rabbit parotid glands with histologic observations at 1, 7, 14, 30, 60 days after ligation. A large battery of special stains and immunohistochemical procedures was employed to define the cell populations. Four stages with overlapping features were observed that led to progressive shutdown of gland activities: 1) marked atrophy of the acinar cells occurred by 14 days, 2) response to and removal of the secretory material trapped in the acinar and ductal lumens mainly between 30 and 60 days, 3) reduction in the number of parenchymal (mostly acinar) cells by apoptosis that occurred mainly between 14–30 days, and 4) maintenance of steady-state at 60 days with a low rate of fluid, protein, and glycoprotein secretion, which greatly decreased the number of leukocytes engaged in the removal of the luminal contents. The main post- ligation characteristics were dilation of ductal and acinar lumens, massive transient infiltration of mostly heterophils (rabbit polymorphonuclear leukocytes), acinar atrophy, and apoptosis of both acinar and ductal cells. Proliferation was uncommon except in the larger ducts. By 30 days, the distribution of myoepithelial cells had spread from exclusively investing the intercalated ducts pre-ligation to surrounding a majority of the residual duct-like structures, many of which clearly were atrophic acini. Thus, both atrophy and apoptosis made major contributions to the post-ligation reduction in gland size. Structures also occurred with both ductal and acinar markers that suggested acini differentiating into ducts. Overall, the reaction to duct ligation proceeded at a considerably slower pace in the rabbit parotid glands than has been reported for the salivary glands of the rat.     

Importance of Long-Term Cycles for Predicting Water Level Dynamics in Natural Lakes

Lakes are disproportionately important ecosystems for humanity, containing 77% of the liquid surface freshwater on Earth and comprising key contributors to global biodiversity. With an ever-growing human demand for water and increasing climate uncertainty, there is pressing need for improved understanding of the underlying patterns of natural variability of water resources and consideration of their implications for water resource management and conservation. Here we use Bayesian harmonic regression models to characterise water level dynamics and study the influence of cyclic components in confounding estimation of long-term directional trends in water levels in natural Irish lakes. We found that the lakes were characterised by a common and well-defined annual seasonality and several inter-annual and inter-decadal cycles with strong transient behaviour over time. Importantly, failing to account for the longer-term cyclic components produced a significant overall underestimation of the trend effect. Our findings demonstrate the importance of contextualising lake water resource management to the specific physical setting of lakes.     

δ15N values of macroalgae as an indicator of the potential presence of waste disposal from land-based marine fish farms

The nitrogen isotope ratio (δ¹⁵N) in tissues of native macroalgae was evaluated as a means of indicating the intensity and spatial extent of organic contamination due to disposal of waste from land-based marine fish farms (LBMFFs). Three species of macroalgae from the genus Fucus and the green macroalgae Codium tomentosum were selected for study. The study was carried out at seven flat marine fish farms located in Galicia (NW Spain). Tests were carried out to determine the intra-annual variation in δ¹⁵N values and any differences between selected macroalgae. The δ¹⁵N values enrichment was observed close to the disposal point, and δ¹⁵N values varied more widely throughout the year (±5.57 ‰) at sites affected by the marine fish farm effluent compared to natural conditions (±2 ‰). No significant differences in the isotopic signals were observed in the different species studied (standard major axis). The δ¹⁵N values of macroalgae may be an ideal means of detecting the presence of LBMFFs effluents.     

Valid and reliable instruments for arm-hand assessment at ICF activity level in persons with hemiplegia: a systematic review

Background

Loss of arm-hand performance due to a hemiparesis as a result of stroke or cerebral palsy (CP), leads to large problems in daily life of these patients. Assessment of arm-hand performance is important in both clinical practice and research. To gain more insight in e.g. effectiveness of common therapies for different patient populations with similar clinical characteristics, consensus regarding the choice and use of outcome measures is paramount. To guide this choice, an overview of available instruments is necessary. The aim of this systematic review is to identify, evaluate and categorize instruments, reported to be valid and reliable, assessing arm-hand performance at the ICF activity level in patients with stroke or cerebral palsy.

Methods

A systematic literature search was performed to identify articles containing instruments assessing arm-hand skilled performance in patients with stroke or cerebral palsy. Instruments were identified and divided into the categories capacity, perceived performance and actual performance. A second search was performed to obtain information on their content and psychometrics.

Results

Regarding capacity, perceived performance and actual performance, 18, 9 and 3 instruments were included respectively. Only 3 of all included instruments were used and tested in both patient populations. The content of the instruments differed widely regarding the ICF levels measured, assessment of the amount of use versus the quality of use, the inclusion of unimanual and/or bimanual tasks and the inclusion of basic and/or extended tasks.

Conclusions

Although many instruments assess capacity and perceived performance, a dearth exists of instruments assessing actual performance. In addition, instruments appropriate for more than one patient population are sparse. For actual performance, new instruments have to be developed, with specific focus on the usability in different patient populations and the assessment of quality of use as well as amount of use. Also, consensus about the choice and use of instruments within and across populations is needed.     

Developmental competence of oocytes from prepubertal Bos indicus crossbred cattle

The aim of the present study was to evaluate the effect of age on embryogenic competence of oocytes recovered from Bos indicus crossbred calves and heifers. Cumulus-oocyte complexes (COCs) were collected from 4- to 7-month-old calves (experiment 1) and from 9- to 14-month-old heifers (experiment 2) during processing at an abattoir. In both experiments cow COCs were used as control. COCs were in vitro matured and fertilized, and the presumptive zygotes co-cultured with cumulus cells until 224 h post insemination (hpi). In experiment 1, the development rate during the first 68-72 hpi was similar (P > 0.05) between embryos derived from calves and cows. Fewer embryos from calves developed to the blastocyst stage, resulting in a lesser blastocyst production as well as lesser hatching rate (P < 0.05). The embryo development after blastocyst stage was, nevertheless, similar (P > 0.05) between blastocysts derived from calves and cows, suggesting that the development after blastocoele formation is not compromised in embryos derived from calves. In experiment 2, there were no differences (P > 0.05) on cleavage, blastocyst and hatching rates between embryos derived from prepubertal heifers and cows. The rate of blastocyst development until hatching was also similar (P > 0.05). These results indicate that oocytes from 9- to 14-month-old B. indicus crossbred heifers have the same developmental competence as oocytes derived from cows, while ocytes derived from 4- to 7-month-old B. indicus crossbred calves are less competent in developing to the blastocyst stage in vitro. It suggests that oocyte competence in B. indicus crossbred cattle is achieved around 9-14 months of age.