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At least 775 records · Page 43Linked to original sources

PubMed1984

[Comparison of growth functions as exemplified by the southern smooth whale Eubalaena australis].

6 year's observations of the southern right whale in the San José Golf off Argentina by an American research team have yielded graphical growth curves. As the values are in good agreement with older results from 1908 to 1969 mathematical approximations are performed giving interesting results and allowing for a better insight into the properties of the growth functions applied. The different course of 3 functions as gained by nonlinear regressions is demonstrated by a graph. The results for 9 growth functions are combined in tables together with the values of the parameters and characteristic data.

Animals↗

PubMed1982

[Hearing mechanisms in dolphins and baleen whales (author's transl)].

Dolphins have the most highly developed acoustical system in nature. They are not only able to hear far into the realm of ultrasound, but they have also developed a magnificent echolocation system. Baleen whales, on the other hand, are specialists for extremely low frequencies, without echolocation. In order to overcome technical problems it was necessary to drastically alter the construction of the hearing organ, of the entire skull, and even the skin. A short review of the current knowledge is presented, along with a discussion of the biotechnology involved.

Animals↗

PubMedDate not supplied

[Comparison of the structures of different forms of sperm whale myoglobin in solution using wide angle x-ray scattering].

Experimental X-ray diffuse scattering curves in a wide range of angles for oxy-, deoxy-, met- and cyan-forms of sperm whale myoglobin in solution have been obtained. It has been found that scattering indicatrices of these ligand forms of myoglobin are well compatible with each other and differ from the theoretical scattering curve of met-myoglobin, calculated from the structure of this protein in crystal. The conclusions have been drawn: (1) on the similarity of myoglobin structures in solution for all the protein forms studied; (2) on the difference in the structure of the above ligand forms of myoglobin in solution from the structure of the protein in crystal by a slight shift (about 2 A) of the "hairpin" GH.

Animals↗

PubMed1980

[Electron transfer in hemoproteins. III. Physico-chemical characteristics of autoxidation of sperm whale oxymyoglobin].

The influence of pH, temperature and ionic strength on the autoxidation of sperm whale oxy-Mb is described and the data obtained are discussed. The process depends on the ionization of two groups with pKeff approximately or equal to 6. They are not accessible histidines of Mb. There are two parallel processes of autoxidation and each of them have a different temperature dependence. Two regions of ionic strength of opposite influence on the rats of autoxidation both at "low" (10 degrees C) and "high" (30 degrees C) temperatures were found.

Animals↗

PubMed1995

Molecular analysis of a heteroclitic T cell response to the immunodominant epitope of sperm whale myoglobin. Implications for peptide partial agonists.

We have investigated the molecular basis for binding and Ag presentation of an immunodominant Th cell determinant of sperm whale myoglobin, a prototype amphipathic helical structure in the native protein. A series of peptides with three different substitutions at each position were evaluated for binding to the class II MHC molecule I-Ad and for activation of two T cell clones with distinct fine specificity, to determine the role of each residue. The assignment of MHC binding and TCR binding residues is consistent with a peptide bound as a twisted beta-strand, with 130 degrees twist similar to that of the influenza hemagglutinin peptide crystallized in the groove of HLA-DR1. This twist gives the peptide amphipathicity, with a periodicity similar to an alpha-helix without its being a helix. Two substituted peptides were discovered to be heteroclitic, but by different molecular mechanisms, one involving gain of a favorable residue and one involving loss of an unfavorable one. Complexes of both peptides with I-Ad had enormously higher affinity for the TCR, but peptide affinity for the MHC molecule was not increased, such that the wild-type peptide acted as a partial agonist and inhibited the response to the heteroclitic ones. Moreover, the magnitude of response was elevated in a way that could not be mimicked by the wild-type peptide even at higher concentration. These results suggest a TCR dwell time requirement for optimal signal transduction that may help explain the mechanism of partial agonism.

Amino Acid Sequence↗

PubMed1993

1H NMR study of the dynamics of the pH modulation of axial coordination in Aplysia limacina (Val(E7)) and sperm whale double mutant His(E7)-->Val,Thr(E10)-->Arg metmyoglobin.

The molecular and electronic structure, thermodynamics, dynamics, and mechanism of interconversion of the pH-modulated reversible equilibria of Aplysia limacina metmyoglobin, (metMb), have been investigated by 1H NMR spectroscopy. The four identified species which interconvert slowly on the NMR time scale (lifetime > 1 ms) are metMbOH (B) at alkaline pH, five coordinate metMb (N) at acidic to neutral pH, an acidic form, A, near pH approximately 4 and an extremely low pH form, D, attributed to an equilibrium unfolded species. The presence of strong distal hydrogen bonding by Arg (E10) to bound hydroxide is detected via a significant solvent isotope effect on the metMbOH (B) hyperfine shifts. Integration of the peak intensities yields pK values of 7.7 and approximately 4 for the B<-->N and N<-->A equilibria, respectively. Saturation transfer via chemical exchange is observed for B<-->N and N<-->A, where the rates for forming metMbOH (B) and the acidic form A from N are base- and acid-catalyzed, respectively, while the reverse rates are first-order. The much slower interconversion rate for N<-->B in A. limacina metMb than His(E7) containing mammalian metMb is attributed to the fact that a ligand bond is broken rather than just proton transferred and that the equilibrium involves a major rearrangement of the orientation of Arg(E10). This conclusion is supported by 1H NMR data for the sperm whale double mutant His(E7)-->Val/Thr(E10)-->Arg metMb, which exhibits a pK approximately 8.7 for the equilibrium between five-coordinate metMb (N) and metMbOH (B) with an even slower interconversion rate than in A. limacina metMb. This double mutant metMbOH (B) exhibits hydrogen bonding by Arg (E10) with coordinated hydroxide similar to that in A. limacina metMbOH. The slow but acid-catalyzed rates of conversion of A. limacina metMb (N) to the acid species A with significantly weakened bonding of the heme iron to the axial His(F8) residue is consistent with protonation of an inaccessible residue and/or a structural change accompanying the protonation equilibrium. It is concluded that metMb will coordinate water strongly only when there is a distal hydrogen bond acceptor residue, while the hydroxide ion is coordinated strongly only if there is a distal hydrogen bond donor residue.

Amino Acids↗

PubMed1996

Mycotic dermatitis in an Atlantic white-sided dolphin, a pygmy sperm whale, and two harbor seals.

An Atlantic white-sided dolphin (Lagenorhynchus acutus), a pygmy sperm whale (Kogia breviceps), 2 harbor seals (Phoca vitulina) developed raised, firm, erythematous, cutaneous nodules that were most prominent on their heads, trunks, and on the caudal portions of their bodies. Prior to the onset of the condition, all 4 animals may have been stressed by factors such as being stranded on a beach, being transported long distances, or being relocated locally. Microbial culturing of the lesions on multiple media yielded fungal isolates containing conidia characteristic of Fusarium spp. Hyphae consistent with those of an ascomycete were evident on histologic examination of lesions. In each treated animal, the dermatitis resolved 3 to 4 weeks after completing treatment with ketoconazole. Fusarium spp may be opportunistic invaders of the skin of marine mammals that have decreased immunocompetence or integumentary compromise.

Animals↗

PubMed1996

Common epidermal lesions of the bowhead whale, Balaena mysticetus.

Samples of common skin abnormalities from 23 subsistence-harvested bowhead whales (Balaena mysticetus) were examined. Most lesions fell into three broad classes: shallow lacerations, circular depressions, and epidermal sloughing. Both circular depression lesions and epidermal sloughing lesions may be divided into more than one subgroup based on morphological criteria. Examination of each of the subgroups using light and scanning electron microscopy suggests relationships among the subgroups of a class. These proposed relationships are discussed, as are some possible etiologies. Scanning electron microscopy reveals abundant bacteria and diatoms present in association with each lesion class but no evidence of a particular association characteristic of a lesion class. The microflora were especially abundant wherever the stratum spinosum was exposed at the skin surface.

Animals↗

PubMed1976

The Bcg for measuring cardiac output in a California Gray Whale.

Resting cardiac output can be predicted reasonably accurately from body mass in man and other mammals. We measured the stroke volume of a 4,500-kg whale and found that Iberall's formula holds true even when body mass is very large. In addition, the Bcg acceleration trace and cardiac indices were remarkably similar to those of 20-gram and 70-kg mammals, mouse and man.

Animals↗

PubMed2004

Origin and evolution of large brains in toothed whales.

Toothed whales (order Cetacea: suborder Odontoceti) are highly encephalized, possessing brains that are significantly larger than expected for their body sizes. In particular, the odontocete superfamily Delphinoidea (dolphins, porpoises, belugas, and narwhals) comprises numerous species with encephalization levels second only to modern humans and greater than all other mammals. Odontocetes have also demonstrated behavioral faculties previously only ascribed to humans and, to some extent, other great apes. How did the large brains of odontocetes evolve? To begin to investigate this question, we quantified and averaged estimates of brain and body size for 36 fossil cetacean species using computed tomography and analyzed these data along with those for modern odontocetes. We provide the first description and statistical tests of the pattern of change in brain size relative to body size in cetaceans over 47 million years. We show that brain size increased significantly in two critical phases in the evolution of odontocetes. The first increase occurred with the origin of odontocetes from the ancestral group Archaeoceti near the Eocene-Oligocene boundary and was accompanied by a decrease in body size. The second occurred in the origin of Delphinoidea only by 15 million years ago.

Animals↗

PubMed1991

Antigen processing by endosomal proteases determines which sites of sperm-whale myoglobin are eventually recognized by T cells.

This study reports an identification of the major processing products of an exogenous protein antigen, viz, sperm-whale myoglobin, as obtained after cell-free processing with partially purified macrophage endosomes. It is demonstrated that such a system yields fragments that are indistinguishable by high performance liquid chromatography analysis from those generated after uptake of myoglobin inside live macrophages. The concerted action of the endosomal proteases cathepsin D and cathepsin B can account for nearly all cleavages observed. Cathepsin D appears to be mainly responsible for the initial cleavage of myoglobin, while cathepsin B catalyzes the C-terminal trimming of initially released fragments. The fragments released by cathepsin D contain most, if not all, major epitopes for murine myoglobin-specific helper T cells. Interestingly, each known T cell epitope of myoglobin is located at the very N terminus of a different myoglobin fragment released upon processing. In order to explain this correspondence, noted also in several other protein antigens, a structural relationship is proposed between antigen processing by cathepsin D and antigen recognition by major histocompatibility complex (MHC) class II products. As is demonstrated here, this relationship may be used as a predictive tool for the identification of MHC-binding sequences as well as of T cell epitopes in their naturally occurring form.

Amino Acid Sequence↗

PubMed1999

Identification of 19 polybrominated diphenyl ethers (PBDEs) in long-finned pilot whale (Globicephala melas) from the Atlantic.

Nineteen tetra- to hexabrominated diphenyl ethers were identified at ppb concentration in the blubber of pilot whale caught off the coast of the Faroe Islands in 1994 and 1996. Higher total concentrations were found in the pooled samples of young males (3,160 ng/g lipid) and females (3,038 ng/g lipid) compared to adult females (843 ng/g and 1,048 ng/g lipid) and males (1,610 ng/g lipids). The predominant isomers in all samples were 2,2',4,4'-TeBDE (PBDE #47) and 2,2',4,4', 5-PeBDE (PBDE #99) accounting for some 70% of the sum of the 19 isomers.

Adipose Tissue↗

PubMed1995

Age trends and reproductive transfer of organochlorine compounds in long-finned pilot whales from the Faroe Islands.

Total DDT and PCB concentrations were determined in blubber of 130 long-finned pilot whales, Globicephala melas (100 females and 30 males) from the Faroe Islands (northern north-east Atlantic). In males and immature females no relation was observed between age and organochlorine concentrations or the ratio of tDDT (total DDT)/PCB; in contrast, concentrations and ratios in mature females declined with age, which is attributed to reproductive transfer to their offspring during gestation and lactation. Relative abundance of DDE respective to tDDT increased in males and young females and decreased in mature females. Organochlorine transfer to offspring during lactation was found to represent about 60-100% of the mother's body load, while that occurring during gestation was estimated to be much lower, in the range 4-10% of mother's body load. Transfer rates tended to decrease with mother's age and were, consequently, much higher in primiparous females than in those that had already given birth. Transplacental rates were found to be consistent with the ratio between mother's body weight and neonatal body weight.

Journal Article↗

PubMed1996

Persistent organochlorines in beluga whales (Delphinapterus leucas) from the St Lawrence River estuary--I. Concentrations and patterns of specific PCBs, chlorinated pesticides and polychlorinated dibenzo-p-dioxins and dibenzofurans.

Blubber samples from beluga whales (Delphinapterus leucas) in the St Lawrence River estuary were analysed for PCB congeners (ortho- and non-ortho-substituted) and other persistent organochlorines as well as chlorinated dibenzo-dioxins/furans (PCDD/Fs). Major individual components (mean concentrations > 1 microg g(-1)) were 4,4'-DDE, -DDD and -DDT, T12 (a toxaphene-related compound), trans-nonachlor, oxychlordane, mirex, HCB, tris(p-chlorophenyl) methane and dieldrin. Concentrations of SigmaPCBs (8.3-412 microg g(-1)), SigmaDDT (3.36-389 microg g(-1)) and mirex (0.18-6.8 microg g(-1)) were particularly elevated relative to other odontocetes in Canadian waters. SigmaDDT, PCBs (as Aroclor), mirex and T12 concentrations were positively correlated with age of adult females (> 10 years) but only weakly, or not significantly, correlated with age of adult males. PCDD/Fs were present at low ng kg(-1) levels and consisted mainly of penta- and hexachlorofurans, and hepta- and octachlorodioxin. CB126 (3,3',4,4',5-PCB) was the most prominent non-ortho-substituted PCB congener in beluga blubber. Total TCDD toxic equivalents averaged 330 ng kg(-1) in females and 1400 ng kg(-1) in males and were dominated by CB126, and the mono-ortho-substituted congeners CB105 and CB118. Biomagnification factors (BMFs) for mirex and SigmaPCB from fish to beluga ranged from 11 to 16, and were similar to BMFs in Arctic animals, indicating that elevated levels in St Lawrence animals are a consequence of relatively high levels of recalcitrant organochlorines in prey of the beluga in the St Lawrence river system.

Journal Article↗

PubMed1996

Persistent organochlorines in beluga whales (Delphinapterus leucas) from the St Lawrence River estuary--II. Temporal trends, 1982-1994.

Blubber samples from 16 dead beluga whales (Delphinapterus leucas) collected during 1993-1994 in the St Lawrence River estuary were analysed for PCB congeners and other persistent organochlorines (DDT-group, chlorinated bornanes (toxaphene, CHB), chlordane SigmaCHL), hexachloro-cyclohexanes (SigmaHCH), chlorobenzenes (SigmaCBz), tris(p-chlorophenyl methane (TPMe) and mirex). Concentrations and relative proportions of major individual organochlorine components were within the same range as previous results for this population. Temporal trends were studied by combining the results with data from the analysis of 44 samples (1986-1990) and (for DDT and Aroclor PCBs only) with 20 samples (1982-1985) reported by Martineau et al., 1987. Results were lipid normalized and then age-adjusted by an ANCOVA model. Significant relationships between age and concentrations of most organochlorine groups were found for females but not for males. Significant declines were observed in SigmaDDT, and Aroclor PCBs (1.5- and 1.9-fold, respectively) in males between the 1982-1985 and 1993-1994 collection periods. Significant declines were also observed for SigmaHCH and SigmaCBz in males between 1986-1988 and 1993-1994. Mean concentrations of CHBs were significantly higher in 1993-1994 than in earlier years while dieldrin, SigmaCHL, mirex, and TPMe showed no trend. Declines in concentrations of major organochlorine groups were not observed in females possibly because of higher year to year, and within year, variation. The temporal trend in DDT and PCB concentrations in male beluga blubber paralleled trends in seals, eels, and seabirds in the St Lawrence estuary observed during the 1980s.

Journal Article↗

PubMed1993

Isolation of St. Louis encephalitis virus from a killer whale.

We report the isolation of St. Louis Encephalitis (SLE) virus from a mature male killer whale (Orcinus orca). This represents the first isolation of SLE virus from a marine mammal. The animal presented with reduced appetite, rapidly became lethargic and subsequently died. Virus-induced CPE was observed in a dolphin cell line, SP-1K (ATCC CCL 78), inoculated with brain, kidney, and lung tissues obtained at necropsy. Electron microscopy of infected SP-1K cells revealed the presence of virions having morphology and size resembling members of the Flaviviridae. Final identification as SLE virus was made by neutralization and immunofluorescence staining tests.

Journal Article↗

PubMed2004

Characterization of F21.A, a monoclonal antibody that recognize a leucocyte surface antigen for killer whale homologue to beta-2 integrin.

The specificity of F21.A, a monoclonal antibody raised against bottlenose dolphin leucocytes, was characterized in killer whale on the basis of immunoprecipitation of a protein of 94 kDa, as well as flow cytometric analysis. While minimally expressed on resting cells, F21.A labeled a homologue to beta-2 integrin in 89-97% of PMA-activated neutrophils, 53-66% of activated monocytes, and activated B cells but not T cells. Activation of neutrophils reached its maximum 10 min after PMA stimulation. F21.A did not label intracellular stores as did both cross-reacting anti-canine CD11b and CD18, suggesting that an activation-induced conformational change would expose a neoepitope recognized by F21.A. F21.A labeling was largely inhibited by pre-incubation with plasma, suggesting a binding site closely related to that for fibrinogen. In vitro phagocytosis and respiratory burst were almost fully inhibited upon pre-incubation with F21.A, demonstrating its functional importance. This antibody is foreseen as a possible valuable diagnostic and research tool in cetacean immunology.

Animals↗

PubMed2004

Immunohistochemical detection of macrophages in the short-finned pilot whale (Globicephala macrorhynchus) and Risso's dolphin (Grampus griseus).

Macrophages play a central role in the immune system, but few markers are available for their detection in cetaceans. The purpose of the present study, therefore, was to examine the cross-reactivity for two cetacean species (short-finned pilot whale and Risso's dolphin) of four anti-human antibodies (SRA-E5, AM-3K, EBM11 and anti-human lysozyme). The distribution of SRA-E5- and AM-3K-positive cells was similar, both antibodies labelling (1) many resident macrophages in the spleen, lymph nodes, liver, lung, kidney, intestine and dermis, and (2) exudate macrophages in the hepatic interlobular septa. Anti-human lysozyme antibody also labelled both resident and exudate macrophages. However, double immunohistochemistry showed that the majority of AM-3K-positive cells in the spleen and liver were also labelled by SRA-E5; on the other hand, anti-human lysozyme-positive cells did not always correspond with AM-3K-positive cells. Cetacean tissues contained no EBM11-positive cells. The study demonstrated the potential values of SRA-E5, AM-3K and anti-human lysozyme antibody for cetacean macrophage studies.

Animals↗