ABSTRACT
Anthropogenic climate change is altering temperature regimes for coastal marine fishes. However, given that temperature changes will not occur in isolation of other stressors, it is necessary to explore the potential consequences of stress on the thermal tolerances and preferences of tropical marine fish in order to understand the thresholds for survival, and predict the associated coastal ecological consequences. In this study, we used exogenous cortisol injections to investigate the effects of a thermal challenge on checkered puffers (Sphoeroides testudineus) as a secondary stressor. There were no significant differences between control and cortisol-treated fish 48h following cortisol treatment for swimming ability (using a chase to exhaustion protocol), blood glucose concentrations or standard metabolic rate. In the lab, control and cortisol-treated puffers were exposed to ambient (29.1±1.5°C), ambient +5°C (heat shock) and ambient -5°C (cold shock) for 4h and to evaluate the consequences of abrupt temperature change on puff performance and blood physiology. Following cold shock, control fish exhibited increases in cortisol levels and weak 'puff' performance. Conversely, fish dosed with cortisol exhibited consistently high cortisol levels independent of thermal treatment, although there was a trend for an attenuated cortisol response in the cortisol-treated fish to the cold shock treatment. A 20-day complementary field study conducted in the puffer's natural habitat, a tidal creek in Eleuthera, The Bahamas, revealed that cortisol-injected fish selected significantly cooler temperatures, measured using accumulated thermal units, when compared to controls. These results, and particularly the discrepancies between consequences documented in the laboratory and the ecological trends observed in the field, highlight the need to establish the link between laboratory and field data to successfully develop management policies and conservation initiatives with regards to anthropogenic climate change.
Subject(s)
Cold-Shock Response/drug effects , Heat-Shock Response/drug effects , Hydrocortisone/pharmacology , Tetraodontiformes/physiology , Animals , Bahamas , Blood Glucose , Swimming , Temperature , Tetraodontiformes/metabolismABSTRACT
Amino acid sequence alignments between the human group C/Bristol and the published porcine group C/Cowden VP6 proteins have revealed a region of extreme sequence divergence. We have been unable to confirm the nucleotide sequence of the Cowden VP6 gene corresponding to this region of divergence. Direct sequencing of a PCR-amplified cDNA pool has revealed a frame shift, and three nucleotide changes, within the published sequence of the porcine (Cowden) VP6 gene. The corrected sequence of the porcine protein revealed a closer homology with VP6 from the Bristol strain and two new human group C rotavirus isolates. Atypical rotaviruses have been detected in the feces of children living in Belém, Brazil, and Preston, U.K. Direct sequencing of PCR-amplified cDNA corresponding to the VP6 gene of one isolate from each location confirmed the presence of a group C rotavirus. The complete nucleotide sequences of the VP6 genes from the group C/Belém and C/Preston rotaviruses contained an open reading frame of 1185 nucleotides (395 amino acids; deduced M(r) 44,669 Da). The Belém VP6 gene demonstrated 97.9% nucleotide homology with the human group C/Bristol VP6 gene and 83.4% nucleotide homology (91.6% deduced amino acid homology) with the corrected porcine group C/Cowden sequence. The Preston VP6 gene demonstrated 99.6% nucleotide homology with the human group C/Bristol VP6 gene and 84.0% nucleotide homology (91.6% deduced amino acid homology) with the corrected porcine group C/Cowden sequence. Remarkably, the deduced amino acid sequence of the Brazilian strain was identical to that of the U.K. isolates.
Subject(s)
Antigens, Viral , Capsid Proteins , Capsid/genetics , Rotavirus Infections/microbiology , Rotavirus/genetics , Amino Acid Sequence , Base Sequence , Brazil , DNA, Viral , Humans , Molecular Sequence Data , Sequence Homology, Nucleic Acid , United KingdomABSTRACT
We evaluated the safety of the measles-mumps-rubella (MMR) combination vaccine in 140 children with egg hypersensitivity. All children, regardless of vaccine skin test results or severity of egg hypersensitivity, were safely immunized with the MMR vaccine. Systemic reactions to MMR vaccine in two nonallergic children were documented, indicating that reactions unrelated to egg protein can occur. With the use of a competitive enzyme-linked immunosorbent assay, the standard MMR injection was found to contain approximately 37 pg of ovalbumin-like material. This study provides 95% confidence that at least 97.5% of egg-allergic children will tolerate MMR vaccine without significant difficulty. Skin testing was not found to be helpful in predicting an adverse reaction. We recommend that the American Academy of Pediatrics consider revising its current policy regarding skin test response to MMR vaccine and administration of MMR vaccine to egg-allergic children.