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141.
Systematic Parasitology - The ergasilid copepod Acusicola margulisae n. sp. is described based on material from three species of cichlid, Amphilophus citrinellus (Günther), Parachromis...  相似文献   
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Atlantic bluefin tuna is an iconic scombrid species with a high commercial and ecological value. Despite their importance, many physiological aspects, especially during the larval stages, are still unknown. Metabolic rates are one of the understudied aspects in scombrid larvae, likely due to challenges associated to larval handling before and during respirometry trials. Gaining reliable estimates of metabolic rates is essential to understand how larvae balance their high growth needs and activity and other physiological functions, which can be very useful for fisheries ecology and aquaculture. This is the first study to (a) estimate the relationship between routine metabolic rate (RMR) and larval dry weight (DW) (mass scaling exponent) at a constant temperature of 26°C, (b) measure the RMR under light and darkness and (c) test whether the interindividual differences in the RMR are related to larval nutritional status (RNA/DNA and DNA/DW). The RMR scaled nearly isometrically with body size (b = 0.99, 0.60–31.56 mg DW) in contrast to the allometric relationship observed in most fish larvae (average b = 0.87). The results show no significant differences in larval RMR under light and darkness, suggesting similar larval activity levels in both conditions. The size explained most of the variability in RMR (97%), and nutritional condition was unrelated to the interindividual differences in routine metabolism. This is the first study to report the metabolic rates of Atlantic bluefin tuna larvae and discuss the challenges of performing bioenergetic studies with early life stages of scombrids.  相似文献   
144.
1. The ideal conditions for a parasite are typically found with its preferred host. However, prior to transmission to a naïve host and successful infection, a parasite may have to withstand extrinsic environmental conditions. Some parasites have adapted to time away from hosts, for example, by co-opting vectors or by having drought-resistant growth stages. However, other parasites may have no obvious adaptations to persist during prolonged transmission cycles. Consequently, the environment may detrimentally impact parasite fitness and ultimately epidemiology. 2. Here, we investigate the impact of nectar-realistic sugar concentrations on the ability of the trypanosome parasite Crithidia bombi, which may be transmitted between conspecifics at flowers, to infect its bumblebee host Bombus terrestris and to reproduce during the infection (parasitaemia). Our results show, following 30 min exposure to our experimental nectars that as sugar concentration increases, infection prevalence and parasitaemia decrease. This is likely due to the increased osmotic stress C. bombi experiences in high sugar, aqueous environments. 3. Consequently, if C. bombi transmission is facilitated by nectar or a high-sugar environment, it may have a negative impact on parasite fitness.  相似文献   
145.
Molecular Biology Reports - Proper bony tissue regeneration requires mechanical stabilization, an osteogenic biological activity and appropriate scaffolds. The latter two elements can be combined...  相似文献   
146.
Noncollagenous proteins in the bone extracellular matrix, such as osteocalcin (OC) and osteopontin (OPN), inherent to evolution of bone as a skeletal tissue, are known to regulate bone formation and mineralization. However, the fundamental basis of this regulatory role remains unknown. Here, for the first time, we use mouse mesenchymal stem/stromal cells (MSC) lacking both OC and OPN to investigate the mechanistic roles of OC and OPN on the proliferation capacity and differentiation ability of MSC. We found that the loss of OC and OPN reduces stem cells self-renewal potential and multipotency, affects their differentiation into an osteogenic lineage, and impairs their angiogenic potential while maintaining chondrogenic and adipogenic lineages. Moreover, loss of OC and OPN compromises the extracellular matrix integrity and maturation, observed by an unexpected enhancement of glycosaminoglycans content that are associated with a more primitive skeletal connective tissue, and by a delay on the maturation of mineral species produced. Interestingly, exogenously supplemented OC and OPN were able to rescue MSC proliferative and osteogenic potential along with matrix integrity and mineral quality. Taken together, these results highlight the key contributions of OC and OPN in enhancing osteogenesis and angiogenesis over primitive connective tissue, and support a potential therapeutic approach based on their exogenous supplementation.  相似文献   
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The first crystal structure of human telomeric DNA in complex with the natural alkaloid berberine, produced by different plant families and used in folk medicine for millennia, was solved by X-ray diffraction method. The G-quadruplex unit features all-parallel strands. The overall folding assumed by DNA is the same found in previously reported crystal structures. Similarly to previously reported structures the ligand molecules were found to be stacked onto the external 5′ and 3′-end G-tetrads. However, the present crystal structure highlighted for the first time, the presence of two berberine molecules in the two binding sites, directly interacting with each tetrad. As a consequence, our structural data point out a 2:1 ligand to G-tetrad molar ratio, which has never been reported before in a telomeric intramolecular quadruplex structure.  相似文献   
149.

Background

The growth and recurrence of several cancers appear to be driven by a population of cancer stem cells (CSCs). Glioblastoma, the most common primary brain tumor, is invariably fatal, with a median survival of approximately 1 year. Although experimental data have suggested the importance of CSCs, few data exist regarding the potential relevance and importance of these cells in a clinical setting.

Methods

We here present the first seven patients treated with a dendritic cell (DC)-based vaccine targeting CSCs in a solid tumor. Brain tumor biopsies were dissociated into single-cell suspensions, and autologous CSCs were expanded in vitro as tumorspheres. From these, CSC-mRNA was amplified and transfected into monocyte-derived autologous DCs. The DCs were aliquoted to 9–18 vaccines containing 107 cells each. These vaccines were injected intradermally at specified intervals after the patients had received a standard 6-week course of post-operative radio-chemotherapy. The study was registered with the ClinicalTrials.gov identifier NCT00846456.

Results

Autologous CSC cultures were established from ten out of eleven tumors. High-quality RNA was isolated, and mRNA was amplified in all cases. Seven patients were able to be weaned from corticosteroids to receive DC immunotherapy. An immune response induced by vaccination was identified in all seven patients. No patients developed adverse autoimmune events or other side effects. Compared to matched controls, progression-free survival was 2.9 times longer in vaccinated patients (median 694 vs. 236 days, p = 0.0018, log-rank test).

Conclusion

These findings suggest that vaccination against glioblastoma stem cells is safe, well-tolerated, and may prolong progression-free survival.  相似文献   
150.
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