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PubMed1987

Electron spin resonance spectra of free radicals formed in the reaction of metmyoglobins with ethylhydroperoxide.

Free radicals of myoglobins were measured at room temperature with an ESR spectrometer equipped with a flow apparatus. When horse heart MetMb was mixed with an equimolar amount of ethyl hydroperoxide (EtOOH), a well resolved ESR spectrum with 6 lines and a shoulder was observed. It reached a maximum in a few seconds and decayed with a half-life of about 10 s when the final concentrations of MetMb and EtOOH were 200 microM. This decay rate was the same at a MetMb concentration of 50 microM. The maximum molar radical concentration amounted to about half of the total myoglobin. In the case of sperm whale myoglobin, a similar 6-line spectrum reached a maximum in 1 s and decayed with a half-life of a few seconds. In this case, however, a small and poorly resolved doublet spectrum remained, the half-life of which was about 8 min. An effect of O2 on the signal decay was evident for horse heart myoglobin, but not for sperm whale myoglobin.

Animals↗
PubMed1981

Sulfated oligosaccharides isolated from the deamination products of heparins.

Porcine heparin, whale heparin, and a solvolyzed porcine heparin were deaminated, and sulfated oligosaccharides, compounds 3f, 4f, 3s, 4s, 5, 6, 7s, 10, 11f, 11s, and 13 were isolated from the deamination products by Dowex 1 x 2 (Cl- form) column chromatography and high voltage paper electrophoresis and/or gel filtration on Sephadex G-25. Based on the results of chemical, 1H and 13C NMR spectral analyses, and of Smith degradation, together with previous observations, the structures of these sulfated oligosaccharides are proposed to be as follows: compound 3f, IdUA(2S)alpha 1 leads to GlcNAc alpha 1 leads to 4GlcUA; compound 4f, IdUA alpha 1 leads to 4GlcNAc(6S) alpha 1 leads to 4GlcUA; compound 3s, IdUA(2S) alpha 1 leads to 4GlcNAc alpha 1 leads to 4 GlcUA beta 1 leads to 4a Man; compound 4s, IdUA alpha 1 leads to 4Glc NAc(6S) alpha 1 leads to 4 GlcUA beta 1 leads to 4aMan; compound 5, IdUA(2S) alpha 1 leads to 4aMan; compound 6, GlcUA beta 1 leads to aMan(6S); compound 7s, IdUA alpha 1 leads to 4aMan(6S); compound 10, IdUA(2S)alpha 1 leads 4GlcNAc(6S)alpha 1 leads to 4 GlcUA beta 1 leads to 4aMan; compound 11f, IdUA(2S) alpha 1 leads 4GlcNAc alpha 1 leads to 4GlcUA beta 1 leads to 4a Man (6S); compound 11s, IdUA alpha 1 leads to GlcNAc(6S) alpha 1 leads to 4GlcUA beta 1 leads to 4aMan(6S); compound 13, IdUA(2S) alpha 1 leads to 4aMan(6S). For ths sulfated disaccharides, the same results as those reported in our previous papers were obtained. On the other hand, the proportion of total sulfated tri- and tetrasaccharides from whale heparin was 1.9 times higher than that from porcine heparine, reflecting a higher content of GlcNAc in the former. Also, the yields of compound 11s from these two heparins were comparable to their anticoagulant activities. In addition, certain 2-O-sulfates on IdUA flanked with GlcNS(6X) (X=H or S) in the heparin molecule are suggested to be important for the activity.

Animals↗
PubMed1990

Energy absorption from ocean waves: a free ride for cetaceans.

Flukes of cetaceans are capable of absorbing energy from ocean waves for propulsion. The extent of this energy absorption is demonstrated by considering the flukes of an immature fin whale, Balaenoptera physalus. In a fully developed seaway corresponding to a wind speed of 20 knots (around Beaufort force 5) and at a low swimming speed, of 2.5 m s-1, this whale was able to absorb up to 25% of its required propulsive power in head seas and 33% of propulsive power in following seas. Consequences of wave-energy absorption for energetics of cetacean migrations are discussed.

Animals↗
PubMed2003

High-pressure 1H NMR study of pressure-induced structural changes in the heme environments of metcyanomyoglobins.

The effect of pressure on the heme environment structure of sperm whale and horse heart metcyanomyoglobins was investigated up to 300 MPa by high-pressure (1)H NMR spectroscopy. Pressure-induced changes in the distances between the observed protons and the heme iron atom were estimated from changes in the dipolar shift due to the paramagnetic effect on the protons. The changes showed that the heme peripheral structure as a whole was compressed by pressure; the movements of the protons in the heme peripheral residues were in the range of +0.16 to -0.54 A/300 MPa. One-dimensional compressibilities for the protons, excluding the protons of the distal His residue, were in the range of 1.0 x 10(-4) to 6.1 x 10(-4)/MPa. The movements of the protons induced by pressure correlated well with the distance between the protons and cavities in the protein. The distal His residue (His 64) moved toward the outside of the heme pocket, but remained in the pocket even at 300 MPa. This movement was driven dominantly by a change in the dihedral angle around the C(alpha)-C(beta) rotational bond of the residue. Comparative work on horse heart metcyanomyoglobin implied that the conformational change of the His 64 imidazole ring was larger in the horse heart metcyanomyoglobin than in the sperm whale metcyanomyoglobin.

Animals↗
PubMed1984

Identification of the titrating group in the heme cavity of myoglobin. Evidence for the heme-protein pi-pi interaction.

The pH dependence of the proton NMR chemical shifts of met-cyano and deoxy forms of native and reconstituted myoglobins reflects a structural transition in the heme pocket modulated by a single proton with pK 5.1-5.6. Comparison of this pH dependence of sperm whale and elephant myoglobin and that of the former protein reconstituted with esterified hemin eliminates both the distal histidine as well as the heme propionates as the titrating residue. Reconstitution of sperm whale met-cyano myoglobin with hemin modified at the 2,4-positions leads to a systematic variation in the pK for the structural transition, thus indicating the presence of a coupling between the titrating group and the heme pi system. The results are consistent with histidine FG3 (His-FG3) being the titrating group, and a donor-acceptor pi-pi interaction between its imidazole and the heme is proposed.

Animals↗
PubMed1990

Protozoan myoglobin from Paramecium caudatum. Its autoxidation reaction and hemichrome formation.

Native oxymyoglobin (MbO2) was isolated directly from the cells of Paramecium caudatum with complete separation from metmyoglobin (metMb) on a DEAE-cellulose column. It was examined for its spectral and stability properties. When compared with sperm whale MbO2 used as a reference, Paramecium MbO2 was found to be much more susceptible to autoxidation over a wide range of pH (4-11) in 0.1 M buffer at 25 degrees C. Kinetic analysis has revealed that a proton-catalyzed displacement of O2- from MbO2 by an entering water molecule can play a dominant role in the autoxidation reaction of Paramecium MbO2 to metMb, as in the case of sperm whale MbO2 involving the distal histidine as its catalytic residue. At pH values higher than 9.5, however, Paramecium MbO2 was found to be oxidized to yield a hemichrome. The spontaneous formation of hemichromes is at variance with the other known myoglobins and is therefore discussed in relation to the unusual amino acid sequence of Paramecium myoglobin having a large number of deletion.

Animals↗
PubMed2005

Evolutionary innovation: a bone-eating marine symbiosis.

Symbiotic associations between microbes and invertebrates have resulted in some of the most unusual physiological and morphological adaptations that have evolved in the animal world. We document a new symbiosis between marine polychaetes of the genus Osedax and members of the bacterial group Oceanospirillales, known for heterotrophic degradation of complex organic compounds. These organisms were discovered living on the carcass of a grey whale at 2891 m depth in Monterey Canyon, off the coast of California. The mouthless and gutless worms are unique in their morphological specializations used to obtain nutrition from decomposing mammalian bones. Adult worms possess elaborate posterior root-like extensions that invade whale bone and contain bacteriocytes that house intracellular symbionts. Stable isotopes and fatty acid analyses suggest that these unusual endosymbionts are likely responsible for the nutrition of this locally abundant and reproductively prolific deep-sea worm.

Animals↗
PubMed1993

Relationship between blood buffering properties, erythrocyte pH and water content, in gray seals (Halichoerus grypus).

The separated plasma of gray seals (Halichoerus grypus) has an unusually high non-bicarbonate buffering capacity (beta NB = d[HCO3-]/dpH = -21 Slykes; Slyke = mmol l-1 pH unit-1). To examine whether this represents a trait of mammalian carnivora, or is related instead to deep diving, we examined blood from dog and killer whale, respectively. The beta NB of separated plasma of dog was typically low (-4 to -8 Slykes), as in other mammals, whereas that of the whale (-13.5 Slykes), while significantly higher than dog, was not nearly as high as in seal. As one would theoretically predict of a blood system with exceptionally high extracellular buffering and functional anion exchange across the erythrocyte membrane, there was little difference in the buffer slope between true plasma and whole blood of seal. This appears to be a novel pattern of CO2 carriage in mammals. Erythrocyte ion concentrations were similar to other mammalian carnivora, with intracellular sodium concentration being high and potassium low. The red cell water content was unaffected by changes in oxygen saturation and tended to decrease when extracellular pH decreased below 7.4. Apart from the comparatively elevated Bohr factor, -0.518 as a function of extracellular pH and -0.550 as a function of red blood cell pH, the blood oxygen binding properties were similar to terrestrial mammals of similar size.

Animals↗
PubMed2002

Temporary shift in masked hearing thresholds in odontocetes after exposure to single underwater impulses from a seismic watergun.

A behavioral response paradigm was used to measure masked underwater hearing thresholds in a bottlenose dolphin (Tursiops truncatus) and a white whale (Delphinapterus leucas) before and after exposure to single underwater impulsive sounds produced from a seismic watergun. Pre- and postexposure thresholds were compared to determine if a temporary shift in masked hearing thresholds (MTTS), defined as a 6-dB or larger increase in postexposure thresholds, occurred. Hearing thresholds were measured at 0.4, 4, and 30 kHz. MTTSs of 7 and 6 dB were observed in the white whale at 0.4 and 30 kHz, respectively, approximately 2 min following exposure to single impulses with peak pressures of 160 kPa, peak-to-peak pressures of 226 dB re 1 microPa, and total energy fluxes of 186 dB re 1 microPa2 x s. Thresholds returned to within 2 dB of the preexposure value approximately 4 min after exposure. No MTTS was observed in the dolphin at the highest exposure conditions: 207 kPa peak pressure, 228 dB re 1 microPa peak-to-peak pressure, and 188 dB re 1 microPa2 x s total energy flux.

Acoustic Stimulation↗
PubMed2005

Statistics and vertical directionality of low-frequency ambient noise at the North Pacific Acoustic Laboratory site.

We examine statistical and directional properties of the ambient noise in the 10-100 Hz frequency band from the NPAL array. Marginal probability densities are estimated as well as mean square levels, skewness and kurtoses in third octave bands. The kurotoses are markedly different from Gaussian except when only distant shipping is present. Extremal levels reached approximately 150 dB re 1 micro Pa, suggesting levels 60dB greater than the mean ambient were common in the NPAL data sets. Generally, these were passing ships. We select four examples: i) quiescent noise, ii) nearby shipping, iii) whale vocalizations and iv) a micro earthquake for the vertical directional properties of the NPAL noise since they are representative of the phenomena encountered. We find there is modest broadband coherence for most of these cases in their occupancy band across the NPAL aperture. Narrowband coherence analysis from VLA to VLA was not successful due to ambiguities. Examples of localizing sources based upon this coherence are included. kw diagrams allow us to use data above the vertical aliasing frequency. Ducted propagation for both the quiescent and micro earthquake (T phase) are identified and the arrival angles of nearby shipping and whale vocalizations. MFP localizations were modestly successful for nearby sources, but long range ones could not be identified, most likely because of signal mismatch in the MFP replica.

Acoustic Stimulation↗
PubMed2006

Automated categorization of bioacoustic signals: avoiding perceptual pitfalls.

Dividing the acoustic repertoires of animals into biologically relevant categories presents a widespread problem in the study of animal sound communication, essential to any comparison of repertoires between contexts, individuals, populations, or species. Automated procedures allow rapid, repeatable, and objective categorization, but often perform poorly at detecting biologically meaningful sound classes. Arguably this is because many automated methods fail to address the nonlinearities of animal sound perception. We present a new method of categorization that incorporates dynamic time-warping and an adaptive resonance theory (ART) neural network. This method was tested on 104 randomly chosen whistle contours from four captive bottlenose dolphins (Tursiops truncatus), as well as 50 frequency contours extracted from calls of transient killer whales (Orcinus orca). The dolphin data included known biologically meaningful categories in the form of 42 stereotyped whistles produced when each individual was isolated from its group. The automated procedure correctly grouped all but two stereotyped whistles into separate categories, thus performing as well as human observers. The categorization of killer whale calls largely corresponded to visual and aural categorizations by other researchers. These results suggest that this methodology provides a repeatable and objective means of dividing bioacoustic signals into biologically meaningful categories.

Acoustics↗
PubMed2001

Heterogeneity of myoglobin distribution in the locomotory muscles of five cetacean species.

Myoglobin is an important storage site for oxygen in the swimming muscles of diving marine mammals. However, little is known about its distribution within muscles since previous studies have relied on single samples. The goal of this study was to determine the distribution of myoglobin within the swimming muscles of five species of cetacean: dusky dolphin, false killer whale, striped dolphin, humpbacked dolphin and bottlenose dolphin. The entire dorsal (epaxial) and ventral (hypaxial) swimming muscles were removed from each animal and weighed. Transverse sections were taken from the cranial, middle and caudal regions of each muscle and sampled along a circular grid with a minimum of 30 sites per section. Spectrophotometric analysis was used to measure the myoglobin concentration of each sample. Contour maps of myoglobin concentration were made for each transverse section. Myoglobin concentration was found to be non-uniformly distributed within the muscle. The interior of the muscle lying closest to the vertebrae showed a significantly higher (11 %) mean myoglobin concentration than the exterior of the muscle for all five species. In the epaxial muscles, the mean myoglobin concentration was significantly higher in the caudal region closest to the flukes. The two deep-water species (false killer whale and striped dolphin) had significantly higher myoglobin concentrations than the three species (dusky, humpbacked and bottlenose dolphins) that occur in shallow, coastal waters. These results show that myoglobin is not homogeneously distributed in the locomotory muscle of cetaceans and that levels may be highest in those areas that produce greater force and consume more oxygen during aerobic swimming. Enhancing oxygen stores in those areas of the muscle that work the hardest would theoretically lengthen the aerobic dive limit of the animal during submerged swimming.

Aerobiosis↗
PubMed1987

Mass stranding of Odontoceti caused by parasitogenic eighth cranial neuropathy.

Hearing organs of the Odontoceti from two mass strandings in 1983 and 1986 were examined histopathologically. In the 1983 stranding, two of three pilot whales (Globicephala macrorhynchus) were necropsied and numerous Nasitrema sp. were found close to the eighth cranial nerve (nervus vistibulo cochlearis) in both animals. Patchy degeneration of the eighth cranial nerve in and out of the modiolus of the cochlea was observed. In the 1986 stranding, five of 125 false killer whales (Pseudorca crassiclens) were examined and numerous trematodes (Nasitrema gondo) were found in the tympanic cavities. Severe degeneration of the eighth cranial nerve was discovered and there were many trematode eggs in the nervous and surrounding tissues. Parasitogenic eighth neuropathy is proposed again as the cause of mass stranding of the Odontoceti.

Animals↗
PubMed1993

The lungworm, Halocercus spp. (Nematoda: Pseudaliidae) in cetaceans from California.

Three cetaceans from Monterey Bay, California (USA), were infected with lung nematodes. A beaked whale calf, Mesoplodon sp. was infected with adult Halocercus sp. This represents a new host record for this nematode. The lungs of a northern right whale dolphin calf, Lissodelphis borealis, contained an unidentified nematode similar in size to Halocercus sp. The presence of Phyllobothrium delphini-type cestode larvae in its blubber is evidence that the calf was feeding on invertebrates. A pregnant harbor porpoise, Phocoena phocoena was infected with the lung nematode H. invaginatus, but the fetus was uninfected. We found no direct evidence of a transplacental mode of transmission for Halocercus sp.

Animals↗
PubMed1998

Twenty years of trace metal analyses of marine mammals in Alaska: evaluation and summation.

The compilation of existing data on contaminants in the marine food chain is essential in addressing concerns regarding the magnitude of potential human exposures and in the evaluation of subsistence food safety. This paper presents a summary of studies on trace metals in tissues of Alaska marine mammals from the 1970s to the present, along with derived mean tissue trace metal concentrations. The derived mean can serve as a norm against which future monitoring results may be compared, and may be used to estimate human exposure to trace metals through the consumption of marine mammals. Additionally, the variation among studies in the reported mean tissue concentrations has been described through a derived standard deviation. Sufficient analytical and methodological details were available to derive means and standard deviations for tissues in bearded seal, bowhead whale, beluga whale, fur seal, harbor seal, Pacific walrus, and ringed seal. A high concordance between trace metal values reported in tissues (i.e., liver, kidney, muscle) was observed despite significant differences in reported sampling and analytical methodologies. Consistent with other reviews of trace metal concentrations in marine species, the standard deviation of tissue metal concentrations was generally < or = 100% of the reported mean. Significant gaps in available information remain, particularly for muscle tissues and for methylmercury, despite the considerable efforts to monitor marine mammal species in Alaska.

Alaska↗
PubMed1998

Micro-compression: a novel technique for the nondestructive assessment of local bone failure.

Many bones within the axial and appendicular skeleton are subjected to repetitive, cyclic loading during the course of ordinary daily activities. If this repetitive loading is of sufficient magnitude or duration, fatigue failure of the bone tissue may result. In clinical orthopedics, trabecular fatigue fractures are observed as compressive stress fractures in the proximal femur, vertebrae, calcaneus and tibia, and are often preceded by buckling and bending of microstructural elements. However, the relative importance of bone density and architecture in the etiology of these fractures is poorly understood. The aim of the study was to investigate failure mechanisms of 3D trabecular bone using micro-computed tomography (microCT). Because of its nondestructive nature, microCT represents an ideal approach for performing not only static measurements of bone architecture but also dynamic measurements of failure initiation and propagation as well as damage accumulation. For the purpose of the study, a novel micro-compression device was devised to measure loaded trabecular bone specimens directly in a micro-tomographic system. The measurement window in the device was made of a radiolucent, highly stiff plastic to enable X-rays to penetrate the material. The micro-compressor has an outer diameter of 19 mm and a total length of 65 mm. The internal load chamber fits wet or dry bone specimens with maximal diameters of 9 mm and maximal lengths of 22 mm. For the actual measurement, first, the unloaded bone is measured in the microCT. Second, a load-displacement curve is recorded where the load is measured with an integrated mini-button load cell and the displacement is computed directly from the microCT scout-view. For each load case, a 3D snap-shot of the structure under load is taken providing 34 microm nominal resolution. Initial measurements included specimens from bovine tibiae and whale spine to investigate the influence of the structure type on the failure mechanism. In a rod-like type of architecture as seen in the whale spine, structural failure was described by an initial buckling and bending of structural elements followed by a collapse of the overloaded trabeculae. In the more plate-like bovine tibial architecture, buckling and bending could not be observed. Failure rather seemed to occur instantaneously. In conclusion, micro-compression in combination with 3D microCT allows visualization of failure initiation and propagation and monitoring of damage accumulation in a nondestructive way. We expect these findings to improve our understanding of the relative importance of density, architecture and load in the etiology of spontaneous fractures of the hip and the spine. Eventually, this improved understanding may lead to more successful approaches to the prevention of age-related fractures.

Animals↗
PubMed1988

A comparison of the geminate recombination kinetics of several monomeric heme proteins.

The geminate rate constants for CO, O2, NO, methyl, ethyl, n-propyl, and n-butyl isocyanide rebinding to soybean leghemoglobin and monomeric component II of Glycera dibranchiata hemoglobin were measured at pH 7, 20 degrees C using a dye laser with a 30-ns square-wave pulse. The results were compared to the corresponding parameters for sperm whale myoglobin and the isolated alpha and beta subunits of human hemoglobin (Olson, J.S., Rohlfs, R.J., and Gibson, Q.H. (1987) J. Biol. Chem., 262, 12930-12938). The rate-limiting step for O2, NO, and isonitrile binding to all five proteins is ligand migration up to the initial geminate state, and the rate of this process determines the overall bimolecular association rate constant for these ligands. In contrast, iron-ligand bond formation limits the overall bimolecular rate for CO binding. The distal pockets in leghemoglobin and in Glycera HbII are approximately 10 times more accessible kinetically to diatomic ligands than that in sperm whale myoglobin. This difference accounts for the much larger association rate constants (1-2 x 10(8) M-1 s-1) that are observed for O2 and NO binding to leghemoglobin and Glycera HbII. The rates of isonitrile migration through leghemoglobin are also very large and indicate a very fluid or open distal structure near the sixth coordination position. In contrast, there is a marked decrease in the rate of migration up to and away from the sixth coordination position in Glycera HbII with increasing ligand size. These results were also used to interpret previously published rate constants and quantum yields for the high (R) and low (T) affinity states of human hemoglobin. In contrast to the differences between the monomeric proteins, the differences between the CO-, O2-, and NO-binding parameters for R and T state hemoglobin appear to be due to a decrease in the geminate reactivity of the heme iron atom, with little or no change in the accessibility of the distal pocket.

Algorithms↗
PubMedDate not supplied

[Identification of species of Diplogonoporus balaenopterae and D. grandis (Cestoda, Diphyllobothriidae)].

Comparative study of diplogonadal diphillobothriids from different species of whalebone whales and from man (Japan) and analysis of literary data has made it possible to establish their identity. Only the species Diplogonoporus balaenopterae (Lönnberg, 1892 capable of infecting whalebone whales, dogs and man can be regarded as really existing. The species D. grandis (Blanchard, 1894) Lühe, 1899 is its synonym.

Animals↗