Polyethylene glycol-induced fusion of heat-inactivated and living protoplasts of Bacillus megaterium.

Protoplasts of Bacillus megaterium, incubated at 50 degrees C for 120 min, lost the ability to revert to bacillary form. Such heat-inactivated protoplasts, however, produced recombinants when fused by polyethylene glycol treatment with normal protoplasts. Although this differential inactivation effect is not yet fully reproducible, reciprocal inactivations of the parental protoplasts in genetic crosses have clearly shown that for protoplast fusion (i) either of the parents may serve as the viable recipient for markers coming from the heated parental protoplasts, and (ii) either of the parents may be rendered nonviable and yet, when fused with a viable partner, contribute to formation of a recombinant. Heat inactivation seems to provide a way to counterselect when few markers are available and one of the parents is prototrophic.     

Role of adipose-derived stromal cells in pedicle skin flap survival in experimental animal models

The use of skin flaps in reconstructive surgery is the first-line surgical treatment for the reconstruction of skin defects and is essentially considered the starting point of plastic surgery. Despite their excellent usability, their application includes general surgical risks or possible complications, the primary and most common is necrosis of the flap. To improve flap survival, researchers have used different methods, including the use of adiposederived stem cells, with significant positive results. In our research we will report the use of adipose-derived stem cells in pedicle skin flap survival based on current literature on various experimental models in animals.     

Gene Expression Variation in Duplicate Lactate dehydrogenase Genes: Do Ecological Species Show Distinct Responses?

Lactate dehydrogenase (LDH) has been shown to play an important role in adaptation of several aquatic species to different habitats. The genomes of Daphnia pulex, a pond species, and Daphnia pulicaria, a lake inhabitant, encode two L-LDH enzymes, LDHA and LDHB. We estimated relative levels of Ldh gene expression in these two closely related species and their hybrids in four environmental settings, each characterized by one of two temperatures (10°C or 20°C), and one of two concentrations of dissolved oxygen (DO; 6.5–7 mg/l or 2–3 mg/l). We found that levels of LdhA expression were 4 to 48 times higher than LdhB expression (p<0.005) in all three groups (the two parental species and hybrids). Moreover, levels of LdhB expression differed significantly (p<0.05) between D. pulex and D. pulicaria, but neither species differed from the hybrid. Consistently higher expression of LdhA relative to LdhB in both species and the hybrid suggests that the two isozymes could be performing different functions. No significant differences in levels of gene expression were observed among the four combinations of temperature and dissolved oxygen (p>0.1). Given that Daphnia dwell in environments characterized by fluctuating conditions with long periods of low dissolved oxygen concentration, we suggest that these species could employ regulated metabolic depression to survive in such environments.     

Proteomic analysis of human substantia nigra identifies novel candidates involved in Parkinson's disease pathogenesis

Parkinson's disease (PD) pathology spreads throughout the brain following a region‐specific process predominantly affecting the substantia nigra (SN) pars compacta. SN exhibits a progressive loss of dopaminergic neurons responsible for the major cardinal motor symptoms, along with the occurrence of Lewy bodies in the surviving neurons. To gain new insights into the underlying pathogenic mechanisms in PD, we studied postmortem nigral tissues dissected from pathologically confirmed PD cases (n = 5) and neurologically intact controls (n = 8). Using a high‐throughput shotgun proteomic strategy, we simultaneously identified 1795 proteins with concomitant quantitative data. To date, this represents the most extensive catalog of nigral proteins. Of them, 204 proteins displayed significant expression level changes in PD patients versus controls. These were involved in novel or known pathogenic processes including mitochondrial dysfunction, oxidative stress, or cytoskeleton impairment. We further characterized four candidates that might be relevant to PD pathogenesis. We confirmed the differential expression of ferritin‐L and seipin by Western blot and demonstrated the neuronal localization of gamma glutamyl hydrolase and nebulette by immunohistochemistry. Our preliminary findings suggest a role for nebulette overexpression in PD neurodegeneration, through mechanisms that may involve cytoskeleton dynamics disruption. All MS data have been deposited in the ProteomeXchange with identifier PXD000427 ( http://proteomecentral.proteomexchange.org/dataset/PXD000427 ).     

When Breathing Interferes with Cognition: Experimental Inspiratory Loading Alters Timed Up-and-Go Test in Normal Humans

Human breathing stems from automatic brainstem neural processes. It can also be operated by cortico-subcortical networks, especially when breathing becomes uncomfortable because of external or internal inspiratory loads. How the “irruption of breathing into consciousness” interacts with cognition remains unclear, but a case report in a patient with defective automatic breathing (Ondine''s curse syndrome) has shown that there was a cognitive cost of breathing when the respiratory cortical networks were engaged. In a pilot study of putative breathing-cognition interactions, the present study relied on a randomized design to test the hypothesis that experimentally loaded breathing in 28 young healthy subjects would have a negative impact on cognition as tested by “timed up-and-go” test (TUG) and its imagery version (iTUG). Progressive inspiratory threshold loading resulted in slower TUG and iTUG performance. Participants consistently imagined themselves faster than they actually were. However, progressive inspiratory loading slowed iTUG more than TUG, a finding that is unexpected with regard to the known effects of dual tasking on TUG and iTUG (slower TUG but stable iTUG). Insofar as the cortical networks engaged in response to inspiratory loading are also activated during complex locomotor tasks requiring cognitive inputs, we infer that competition for cortical resources may account for the breathing-cognition interference that is evidenced here.     

Abdominal setae and midgut bacteria of the mudshrimp Pestarella tyrrhena

We investigated the diversity of the bacterial 16S rRNA genes occurring on the abdominal setal tufts and in the emptied midgut of the marine mudshrimp Pestarella tyrrhena (Decapoda: Thalassinidea). There were no dominant phylotypes on the setal tufts. The majority of the phylotypes belonged to the phylum Bacteroidetes, frequently occurring in the water column. The rest of the phylotypes were related to anoxygenic photosynthetic α-Proteobacteria and to Actinobacteria. This bacterial profile seems more of a marine assemblage rather than a specific one suggesting that no specific microbial process can be inferred on the setal tufts. In the emptied midgut, 64 clones were attributed to 16 unique phylotypes with the majority (40.6%) belonging to the γ-Proteobacteria, specifically to the genus Vibrio, a marine group with known symbionts of decapods. The next most abundant group was the ɛ-Proteobacteria (28.1%), with members as likely symbionts related to the processes involving redox reactions occurring in the midgut. In addition, phylotypes related to the Spirochaetes (10.9%) were also present, with relatives capable of symbiosis conducting a nitrite associated metabolism. Entomoplasmatales, Bacteroidetes and Actinobacteria related phylotypes were also found. These results indicate a specific bacterial community dominated by putative symbiotic Bacteria within the P. tyrrhena’s midgut.     

DNA profiling by arrayCGH in acute myeloid leukemia and myelodysplastic syndromes

Acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) represent two distinct but related myeloid haematological neoplasms. At diagnosis, a substantial proportion of cases show cytogenetic and molecular genetic markers whose range of specificity is highly variable. Most specific reciprocal translocations, as t(8;21)(q21;q21) or t(15;17)(q22;q21), have been extensively studied and are currently introduced in clinical diagnosis. Two other major groups remain to be better characterized at the genetic and genomic level: cases with normal karyotype and cases with complex aberrations. Comparative genomic hybridization (CGH) performed on chromosomes was the first approach taken and nearly 300 cases studied by this technique have already been reported. Array based CGH has also been applied to a smaller number of cases. Both types of genomic studies have confirmed that recurrent genomic losses and gains can almost exclusively be found in cases with complex karyotype. In most cases with normal karyotype (as well as in others with single chromosome aberrations as trisomy 8), arrayCGH has been able to unveil small DNA copy number changes whose recurrence is very low. Recently, single- nucleotide-polymorphism based arrays have been used in AML showing that loss of heterozygosity (LOH) is a common feature in normal karyotype leukemia.