bluuebunny/crossref_metadata_2025 huggingface dataset:
Activity rhythms in female montane voles (Microtus montanus)
Authors: Rowsemitt Carol N.
Published: August 2008

Seasonal changes in activity patterns have been reported in several species of arvicoline (= microtine) rodents in the wild. Adult male montane voles (Microtus montanus) shift from predominantly nocturnal running wheel use under long photoperiod to predominantly diurnal running wheel use under short photoperiod. Under the same conditions, females also increase diurnal activity under short photoperiod. However, females display more variability in activity patterns under long photoperiod than do males.
Phylogeny and zoogeography of the New World terrestrial amphipods (landhoppers) (Crustacea: Amphipoda; Talitridae)
Authors: Lindeman Dorothy
Published: August 2008

A phylogenetic analysis of the known New World tropical landhoppers (terrestrial amphipods) tests the hypothesis that the landhoppers of México, Jamaica, and Central America are derived monophyletically from local beach flea ancestors (of the Tethorchestia group). The results indicate that Cerrorchestia is derived directly from an ancestor of Chelorchestia, a palustral (salt marsh) taxon, and that Caribitroides shares an ancestor with Chelorchestia. The derivation of landhoppers from beach fleas is not supported. The zoogeography of New World landhoppers is explained by a combination of Caribbean tectonic movements and short-distance rafting dispersal. Caribitroides is believed to have evolved in México, with dispersal to Jamaica, as the Caribbean plate moved northeast past México. Cerrorchestia is believed to have evolved in Costa Rica – Panama as a relatively recent offshoot of the Chelorchestia group. Central American landhoppers are found almost exclusively in highland cloud forest and in the wet forests to the windward of these highlands, down to the minimum altitude at which sufficiently wet conditions are maintained.
Prevalence of trypanosome infections in the marine leech Johanssonia arctica off eastern Newfoundland
Authors: Khan R. A.
Published: August 2008

A study was conducted to determine the prevalence of trypanosomal stages, indistinguishable from Trypanosoma murmanensis, in the marine leech Johanssonia arctica off eastern Newfoundland, Canada, from 1972 to 1990. Prevalence of the infection was highest between May and October, with a peak in July, and lowest during winter. The highest prevalences were also associated with a high percentage of engorged leeches in summer–autumn. Prevalence of infection in recently emerged leeches, following their first blood meal, was greater in July than at other times of the year. Similarly, the percentage of infection increased with age of the leech and was greater in summer than in winter. The number of leeches, as well as the prevalence of infection, decreased offshore. Prevalence of infection was observed to be substantially lower in saliva than in gut contents. A study of host preference on J. arctica indicated that a greater percentage of blood meals was taken from flatfish in summer; in winter, as the latter became submerged in sediment, there was a shift in feeding to eelpouts and wolffish. The prevalence of the infection was greater in fish, especially flatfish, closer to shore than in offshore areas and corresponds to the abundance of the vector. Results from the present study suggest that infections in the leech reach a peak during summer–autumn and are acquired mainly from flatfish, in which prevalence of the infection adjacent to the coast is highest.
Grooming by moose (Alces alces) infested with the winter tick, Dermacentor albipictus (Acari): a mechanism for premature loss of winter hair
Authors: Samuel W. M.
Published: August 2008

Grooming behaviors of 13 captive moose (Alces alces) experimentally infested with winter ticks (Dermacentor albipictus) were identified, quantified, and compared with those of 11 uninfested moose form October to June. Grooming by infested moose was more frequent and of longer duration than grooming by uninfested moose. It occurred extensively in March and April, when ticks were gorging on blood, and resulted in premature loss of winter hair. Uninfested moose groomed little throughout the study and only lost hair in May and June as part of the spring molt. Grooming by infested moose diminished in May and June, when ticks had dropped from moose. Grooming behaviors included licking/biting, rubbing, scratching with the hooves, and shaking. The implications of these behaviors for moose are discussed.
Evolutionary trends in the morphology of the intercalary phalanx of anuran amphibians
Authors: Paukstis Gary L. , Brown Lauren E.
Published: August 2008

A comparison was made of the intercalary phalanx of the digits of 322 specimens of anurans representing 6 families, 34 genera, and 92 species from six continents. Eleven distinct types of intercalaries were categorized on the basis of morphology and position in relation to other phalanges. The intercalary has evolved primarily for use in climbing, although in one genus it is specifically modified for aquatic life, and in another group, degeneration of the intercalary has occurred with the evolution of forelimb burrowing. Various lines of evidence indicate that convergent evolution of the intercalary has probably occurred several times.
Effects of a sudden increase in natural mortality of adults on a population of the common snapping turtle (Chelydra serpentina)
Authors: Brooks Ronald J. , Brown Gregory P. , Galbraith David A.
Published: August 2008

A northern population of snapping turtles (Chelydra serpentina) centred around Lake Sasajewun in the Wildlife Research Area in Algonquin Park, Ontario, has been studied and individually marked since 1972. From 1972 to 1985, annual mortality and survivorship of adult females had been estimated at 1 and 96.6%, respectively, and only six dead turtles were found. Lake Sasajewun's population of C. serpentina was estimated in 1978–1979 and 1984–1985 at 38 and 47 adults, respectively. From 1976 to 1987, total number of nests found in the study area remained fairly constant and there were no significant changes in mean clutch size, mean clutch mass, or mean egg mass. On the main nest site, recruitment from 1976 to 1987 was 1.15 (1.8%) new females per year. From 1987 to 1989, we found 34 dead adult snapping turtles in the Wildlife Research Area. Observations of freshly dead animals indicated that most were killed by otters (Lutra canadensis) during the turtles' winter hibernation. A few uninjured turtles also died of septicemia in early spring shortly after emerging from hibernation. The estimated number of adults in Lake Sasajewun was 31 in 1988–1989, and the minimum number of adult residents known to be alive in the lake dropped from 47 in 1986 to 16 in 1989. In 1986 and 1987, annual adult female survivorship was estimated at 80 and 55%, respectively, and estimated numbers of nesting females declined from 82 in 1986 to 71 and 55 in 1987 and 1988, respectively. The actual number of nests found declined by 38 and 20% over the same periods. Although no significant differences occurred in mean egg mass or mean clutch size between 1987 and 1989 and earlier years, the mean clutch mass in 1988 was larger than in 1977 or 1978. This difference appeared to be due to a gradual increase in the mean age and body size of breeding females rather than to density-dependent changes. Recruitment into the adult breeding female population in 1987–1989 remained less than two individuals per year. Hatchling survival and number of juveniles were low throughout the study. Our observations support the view that populations of species with high, stochastic juvenile mortality and long adult life spans may be decimated quickly by increased mortality of adult animals, particularly if numbers of juveniles and immigrants are low. Recovery of such populations should be very slow because of a lack of effective density-dependent response in reproduction and recruitment.
Henlea yukonensis (Oligochaeta: Enchytraeidae), a new species from the Yukon Territory, with comments on Henlea Michaelsen, 1889 and Punahenlea Nurminen, 1980
Authors: Tynen Michael J. , Coates Kathryn A. , Smith C. A. S. , Tomlin Alan D.
Published: August 2008

Henlea yukonensis Tynen and Coates, sp.nov., a large enchytraeid 10–60 mm long and 2 mm in diameter, is described from the western foothills of the Richardson Mountains. Henlea yukonensis is distinguished from H. udei (Eisen, 1904), a species known only from Alaska, by spermathecal form and by the locations of the intestinal diverticula and dorsal blood vessel origins. Henlea yukonensis could be included in Hepatogaster Cejka, 1910, a subgenus of Henlea Michaelsen, 1889 characterized by intestinal diverticula with a multitubular substructure, if that form of intestinal diverticulum were shown to be apomorphic in Henlea. This form of diverticulum is described only in a few Siberian and North American species of Henlea: H. ochracea (Eisen, 1878) sensu Welch, 1919, H. moderatoidea Altman, 1936, and H. udei (Eisen, 1904), Subgeneric classification within Henlea awaits the resolution of diagnostic character states and of character polarities for the genus as a whole. Setal size distribution, oesophageal appendages, and intestinal diverticula probably have unique states that could delimit Henlea. However, our limited knowledge of the last two characters presently restricts their utility to diagnoses of the genus and subgenera. Punahenlea Nurminen, 1980 is not presently distinguished from Henlea by any reliable taxonomic characteristics.
Coyote space use in relation to prey abundance
Authors: Mills L. Scott , Knowlton Frederick F.
Published: August 2008

Food abundance is an important factor determining space use in many species, but its effect on carnivore home range and territory size has rarely been investigated. We explored the relationship between food abundance for the coyote (Canis latrans) and space use in two study areas in the northern Great Basin, where the primary prey, the black-tailed jackrabbit (Lepus californicus), fluctuates dramatically in abundance. At one site, home ranges and territories were significantly larger during a time of prey-scarcity than when prey was abundant. Coyotes on the second site had similar-size home ranges and territories at low and high prey abundance, but a higher proportion and probably a higher number of individuals were transients during the prey-scarcity period. We propose mortality rates of coyotes as an important factor mediating adjustments in space use to food abundance, and suggest two mechanisms by which mortality might interact with food abundance. Higher mortality rates may simply permit more rapid adjustment of home range size to changing food conditions. Alternatively, higher mortality may selectively eliminate transients, thus reducing the impact of intruders in limiting the size of the remaining territories.
Competition at the carcass: opportunities for social foraging by turkey vultures in southern Ontario
Authors: Prior Kent A. , Weatherhead Patrick J.
Published: August 2008

The level of intra- and inter-specific competition experienced by turkey vultures (Cathartes aura) at carrion food patches in southern Ontario was investigated. Despite a diversity of avian and mammalian species directly or indirectly competing with turkey vultures for carrion, only coyotes (Canis latrans) were found to occasionally deplete experimental food patches sufficiently to limit use by turkey vultures. Though American crows (Corvus brachyrhynchos) were the species most commonly observed making use of carrion, their lower food requirements and subordinate status make their competitive impact minimal. In fact, crows appear to inadvertently aid turkey vultures in discovering carrion, since vultures arrived at food patches earlier when crows were already present. Carrion generally lasted long enough for turkey vultures to use roost-centred information transfer as a potential foraging tactic. However, the high degree of intraspecific competition and food patch monopolization by socially dominant individuals limit the presumed benefits for those with the greatest need for food information (i.e., socially subordinate individuals who are inferior foragers). Based upon these findings we suggest that turkey vultures may realize only limited benefits at best from roost-centred food information transfer.
Foraging habitat selection by American and Magellanic oystercatchers (Haematopus palliatus and H. leucopodus) on Patagonian tidal flats
Authors: Siegel-Causey Douglas
Published: August 2008

I examined the foraging behaviour of American and Magellanic oystercatchers on Patagonian tidal flats in the context of several abiotic and social factors. I analyzed the simultaneous effect of tidal state, wind speed, temperature, habitat preference, and species abundance of one species on the other by means of multiway contingency tables and loglinear models. Diets of both species were similar and reflected the natural abundances of prey items in the tidal flats. Both species were strongly influenced by tidal state when selecting foraging habitat, but other factors modified their preferences. I found that the foraging behavior of American Oystercatchers was determined solely by abiotic factors; i.e., tidal state, foraging period, and a higher order interaction effect between wind speed and tidal state. By contrast, no combination of abiotic factors was sufficient to explain the observed abundances of Magellanic Oystercatchers. Instead, their foraging behavior was facilitated by the presence of congeners in addition to abiotic factors.
Species-specific recognition in birds: an experimental investigation of Wilson's storm-petrel (Procellariiformes, Hydrobatidae) by means of digitalized signals
Authors: Bretagnolle Vincent , Robisson Patrice
Published: August 2008

Most acoustic studies on birds dealing with species specificity have concerned the territorial function of the song in passerines. We studied species specificity in a non-passerine bird, Wilson's storm-petrel (Oceanites oceanicus). Males of this species attract females by uttering a chattering call, which acts as a premating isolating mechanism. We analysed the encoding of species specificity in the call by measuring the variation in its physical features. We then experimented in the field with played-back computer-synthesized signals and identified the relevant cues that elicited species recognition, namely the modal frequency and the durations of both syllable and silence. We relate our results to species specificity in passerines, and emphasize differences in the responses with respect to sex and status of responding birds, the differences being due to the meaning of the species-specific signal for the receiver.
Compensatory growth of wapiti (Cervus elaphus) on aspen parkland ranges
Authors: Watkins W. G. , Hudson R. J. , Fargey P. L. J.
Published: August 2008

We studied the behavior and performance of wapiti on aspen parkland ranges in central Alberta after a winter in which one group received a pelleted alfalfa–barley supplement and another served as a control, on an unsupplemented diet. Wapiti that were lighter at the end of winter because they were young or because they did not receive nutritional supplementation grew faster on summer pasture. This compensatory gain was not explained by any one factor. Intake rates, bite rates, bite sizes, and diet selectivity varied by habitat and date, but did not differ consistently between wapiti receiving supplemented and unsupplemented diets. Irrespective of winter nutrition treatment, wapiti apportioned feeding time to different habitats in relation to foraging returns. However, by feeding longer, those on an unsupplemented diet consumed more forage during the spring flush in mid-April, and over all time periods, lighter individuals consumed more relative to body weight. Diet digestibility as a consequence of either greater forage selectivity or digestive efficiency was unaffected by nutritional history. Resting metabolic rates increased from 495 kJ∙kg−0.75∙d in late winter to 641 kJ∙kg−0.75∙d in summer, but were not significantly related to compensatory gain or reproductive status.
Age, growth, and reproduction in Hector's dolphins
Authors: Slooten Elisabeth
Published: August 2008

Data are provided on the reproductive biology and life history of Hector's dolphin, Cephalorhynchus hectori, a species found only in New Zealand waters. Samples were taken from 60 dolphins found beach-cast or killed incidentally in fishing gear. Male and female reproductive tracts were examined macroscopically and histologically, and tooth sections provided an age estimate for each individual. The traditional procedure for preparing dolphin teeth was simplified by using a faster stain and more readily available embedding and sectioning equipment. An important advantage of this method is that it facilitates the cutting of thinner sections, increasing the chances of obtaining a section through the centre of the pulp cavity. Sectioning revealed an open pulp cavity in all the teeth examined. The maximum observed age was 19 years for females and 20 years for males. Females reach a larger body size than males, and are apparently larger than males at any given age. Males appear to reach sexual maturity between 6 and 9 years of age, whereas females give birth to their first calf at 7–9 years of age. Mature males have extremely large testes relative to their body size. The largest male found in this study weighed 41.5 kg, with testes (including epididymides) totalling 1.21 kg.
The status of the P2 song morph, a North American green lacewing of the Chrysoperla cornea species-group (Neuroptera: Chrysopidae)
Authors: Henry Charles S.
Published: August 2008

The substrate-borne courtship song of the P2 song morph of Chrysoperla plorabunda is described. It is a tremulation signal, produced by rapid vertical oscillation (jerking) of the abdomen. Both sexes produce identical shortest repeated units (SRUs) and must duet with one another before mating. In each of five principal features of its song, the P2 morph is strikingly homogeneous throughout its broad geographical range in western North America; a stepwise multiple regression procedure shows that populations from the Pacific Northwest, central California, and southern California are acoustically identical. Recombination in subsequent laboratory generations has no effect on song variance, suggesting that the morph is stable and not of hybrid origin. The nominate form of C. plorabunda, here called P1, co-occurs with P2 at sites north of California and is morphologically identical with it. However, the songs of the two morphs differ significantly from one another in every feature; in particular, P2 volleys are longer and spaced farther apart than P1 volleys. Complicating the picture is a third cryptic song morph, P3, which co-occurs with P2 at most sites and produces a song characterized by even longer volleys. Hybrids produced in the laboratory between P1 and P3 have songs that superficially resemble those of P2, but which in fact are significantly different in most respects. The P2 song morph seems to be a cohesive genetic unit deserving recognition as a separate species.
Do continental moose ranges improve during cloudy summers?
Authors: Bø Steinar , Hjeljord Olav
Published: August 2008

We determined differences in forage quality and observed food and habitat selection by radio-collared moose (Alces alces) in southeastern Norway during the summers of 1986 and 1987. June weather was sunny during 1986 and cloudy and wet during 1987. In the most important browse species (Betula sp.), leaf tannin content was lower and the protein: dry matter ratio higher in 1987 than in 1986. Habitat use did not differ significantly between the two summers. During 1987, use of grasses (graminoids) was significantly greater and moose showed a tendency toward greater usage of the most common plant species. The changes in forage quality and choice of plant species by moose during 1987 strengthen earlier assumptions, based on weight comparisons, that continental moose ranges improve during cloudy, wet summers.
Rhinoraja longi, a new species of skate from the outer Aleutian Islands, with comments on the status of Rhinoraja (Chondrichthyes, Rajoidei)
Authors: Raschi W. , McEachran J. D.
Published: August 2008

Discovery of a new species of skate, Rhinoraja longi, from the outer Aleutian Islands led to a re-evaluation of the status and species composition of this genus. Rhinoraja is presently distinguished from Bathyraja primarily by its basally segmented rostral shaft and slightly longer tail. The genus contains five species plus the new species, and is endemic to the North Pacific arc, from Hokkaido, Japan, to the Aleutian Islands. The six species are very similar in morphology, meristics, and skeletal structure but differ substantially from each other in dermal denticle characters. Salient features of systematic significance in the dermal skeleton include the density and the relative proportions of total height, base height, and crown height of the denticles. The number and distribution of normal and alar thorns are also important.
A phylogenetic analysis of the Phreodrilidae (Annelida, Oligochaeta), with a description of a new species
Authors: Brinkhurst R. O.
Published: August 2008

A combination of computerized and classical methods suggests that the Phreodrilidae be classified as a monophyletic family with two subfamilies, Phreodrilinae subfam.nov. and Phreodriloidinae subfam.nov. The former includes the genera Phreodrilus and Antarctodrilus gen.nov. and the latter the genera Phreodriloides, Insulodrilus gen.nov., Schizodrilus, and Astacopsidrilus. The new species Astacopsidrilus jamiesoni is similar to its congeners except that the atria and vasa deferentia are short and joined together basally. The spermathecal ampullae are distinctly paired in A. jamiesoni, but there may be some degree of fusion of the ampullae in the two other ectocommensal species. One of the latter may have dorsal chaetae restricted to the posterior segments. Astacopsidrilus novus supposedly has two pairs of testes (in X–XI), and the atria are elongate, unlike those of A. jamiesoni. Astacopsidrilus novus also has more dorsal chaetae in anterior bundles than A. jamiesoni.
Protein intake and the dynamics of the postnuptial molt in White-crowned Sparrows, Zonotrichia leucophrys gambelii
Authors: Murphy Mary E. , King James R.
Published: August 2008

Nutritional constraints have often been invoked as either ultimate or proximate agents that account for variation in the schedule and intensity of molt and the quality of the new plumage. We examined this hypothesis by analyzing the dynamics of postnuptial molt and the condition of the new feathers in seven groups of White-crowned Sparrows (Zonotrichia leucophrys gambelii) in which the mean daily consumption of high-quality protein in otherwise balanced diets ranged from subadequate (0.20 g/bird) to superadequate (3.23 g/bird). Mean body mass during molt did not differ among the six groups consuming 0.46 g/bird-day or more (0.69, 0.97, 1.76, 1.99, and 3.23 g/bird-day) but was significantly less throughout molt (e.g., ca. 20 vs. 26 g in mid to late molt) in the group subsisting on 0.20 g/bird-day. The mean date of molt onset (27 June – 2 July) was statistically the same in all the groups, as was the duration of molt (51–57 days) in the six groups consuming 0.46 g or more of protein per day. In the lowest-protein group (0.20 g/bird-day) the molt lasted > 111 days. The protraction of molt resulted from both a slower growth rate of flight feathers and longer shedding intervals between them. The new primary remiges of the birds in this group averaged 4–9% shorter than in the six other groups, which were statistically indistinguishable from each other. These results are consistent with those of earlier experiments on the effects on molt of shortages of nutritionally balanced diets and of diets deficient only in sulfur amino acids. Molt is very resistant to the kinds of malnutrition that free-living birds may encounter. Only very severe levels of privation that sharply depress body mass and potentially threaten life significantly slow the rate of molt or reduce the quality of plumage.
Cloacal anatomy of metamorphosed and neotenic salamanders
Authors: Licht Lawrence E. , Sever David M.
Published: August 2008

Ambystoma gracile is a polymorphic species, with some individuals attaining sexual maturity in the larval form. Such neotenic A. gracile retain larval characters in nonreproductive tissues. The cloacal anatomy of metamorphosed and neotenic individuals of both sexes was examined to determine the degree to which the larval state is reflected in reproductive structures. No difference in anatomy or onset of development of cloacal glands exists between metamorphosed and neotenic salamanders; thus, individuals should be capable of interbreeding. One autotriploid male showed few signs of cloacal gland development despite well-developed somatic growth, which supports the hypothesis of delayed maturity or sterility in male polyploid salamanders.
Bionomics of Cheyletus eruditus (Schrank) (Acarina: Cheyletidae), a predator of Lepidoglyphus destructor (Schrank) (Acarina: Glycyphagidae), at three constant temperatures
Authors: Barker Philip S.
Published: August 2008

The duration and mortality of immature stages of the predatory mite Cheyletus eruditus (Schrank) were examined at 14, 18.5, 22, and 25 °C and 76% RH. Life tables and schedules of female eggs laid by each female per day were made from records of daily oviposition and adult mortality. The net reproductive rate (ratio of total female births in two successive generations) of C. eruditus varies from 40.7 at 18.5 °C to 74.4 at 25 °C and brackets the net reproductive rates of the prey Lepidoglyphus destructor (Schrank). Mean generation time and finite rates of increase (multiplication per female each day) varied from 52.2 days and 1.073 at 18.5 °C to 24.2 days and 1.194 at 25 °C. Maximum longevity was 107, 67, and 56 days at 18.5, 22, and 25 °C, respectively. Cheyletus eruditus also consumed first-instar larvae of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), and first- and second-instar larvae of the flour mill beetle, Cryptolestes turcicus (Grouvelle).
Cold tolerance of the pupae in relation to the distribution of swallowtail butterflies
Authors: Kukal Olga , Ayres Matthew P. , Scriber J. Mark
Published: August 2008

A steep decline in the diversity of swallowtail butterfly species at high latitudes could be due to limited cold tolerance of overwintering pupae. If this is so, species with unusually northerly distributions should be unusually cold tolerant. We compared the northerly distributed Papilio canadensis with its southern relative, P. glaucus. Pupae were exposed for 2–5 months to four acclimatization treatments: outdoors in Alaska, outdoors in Michigan, constant 5 °C, and constant −25 °C. Field temperatures encountered by pupae in Alaska were lower than in Michigan. The supercooling point of P. glaucus pupae was unaffected by acclimatization (mean ± SE= −23.5 ± 0.52 °C). The supercooling point of P. canadensis pupae did not differ from that of P. glaucus pupae, except following acclimatization in Alaska, when it dropped to −27.0 ± 0.55 °C. Survival of pupae in Michigan was high for all populations (70–90%); in Alaska, survival of P. canadensis was just as high, but survival of P. glaucus dropped to 14%. Freezing was usually fatal in both species, but death was not immediate. No pupae survived 6 weeks at −25 °C. Trehalose was the most conspicuous metabolite revealed by nuclear magnetic resonance spectroscopy of live pupae and hemolymph. Labelled glucose was metabolized differently by the two species, which may underly the difference in acclimation potential and cold tolerance. The results support the hypothesis that winter temperatures limit swallowtail distributions.
EFFECT OF DEVIATION ON OPTICAL TRANSMISSION THROUGH THUE–MORSE MULTILAYERS
Authors: CHEN YUXING , YANG XIANGBO
Published: August 2008

In this paper, we propose a deviation model and consider the transmission property of Thue–Morse (TM) multilayers with deviations. It is found that at the central wavelength for very simple systems, the transmission coefficients (TCs) have nothing to do with the deviation of a machine, but when a multilayer system becomes more complex, one should use the most precise machine in order to make the system possess the designed value of TC. However, if superlattices become more complicated, one may choose a machine with a suitable relative error, but not the most accurate machine, to manufacture a perfect system. Additionally, after the number of layers exceeds some critical value, the very sophisticated optical superlattices could only be manufactured by very precise machines. The results would be useful for designing and manufacturing thin films of optical superlattices.
Gastrin increases mcl-1 expression in type I gastric carcinoid tumors and a gastric epithelial cell line that expresses the CCK-2 receptor
Authors: Pritchard D. M. , Berry D. , Przemeck S. M. C. , Campbell F. , Edwards S. W. , Varro A.
Published: August 2008

Elevated serum concentrations of the hormone gastrin are associated with the development of gastric carcinoid tumors, but the mechanisms of tumor development are not fully understood. We hypothesized that the antiapoptotic effects of gastrin may be implicated and have therefore investigated the role of antiapoptotic members of the bcl-2 family of proteins. AGS-GR human gastric carcinoma cells stably transfected with the CCK-2 receptor were used to assess changes in the expression of bcl-2 family members following gastrin treatment and the function of mcl-1 during apoptosis was investigated by use of small-interfering RNA (siRNA). Treatment of AGS-GR cells with 10 nM gastrin for 6 h caused maximally increased mcl-1 protein abundance. Gastrin-induced mcl-1 expression was inhibited by the transcription inhibitor actinomycin D and by the protein synthesis inhibitor cycloheximide. Downstream signaling of mcl-1 expression occurred via the CCK-2 receptor, protein kinase C, and MAP kinase pathways, but not via PI 3-kinase. Transfection with mcl-1 siRNA significantly suppressed mcl-1 protein expression and abolished the antiapoptotic effects of gastrin on serum starvation-induced apoptosis. Mcl-1 protein expression was also specifically increased in the type I enterochromaffin-like cell carcinoid tumors of 10 patients with autoimmune atrophic gastritis and hypergastrinemia. Gastrin therefore signals via the CCK-2 receptor, protein kinase C, and MAP kinase to induce expression of antiapoptotic mcl-1 in AGS-GR cells, and mcl-1 expression is also increased in human hypergastrinemia-associated type I gastric carcinoid tumors. Gastrin-induced mcl-1 expression may therefore be an important mechanism contributing toward type I gastric carcinoid development.
Mice lacking the Na+/H+ exchanger 2 have impaired recovery of intestinal barrier function
Authors: Moeser Adam J. , Nighot Prashant K. , Ryan Kathleen A. , Simpson Janet E. , Clarke Lane L. , Blikslager Anthony T.
Published: August 2008

Ischemic injury induces breakdown of the intestinal barrier. Recent studies in porcine postischemic tissues indicate that inhibition of NHE2 results in enhanced recovery of barrier function in vitro via a process involving interepithelial tight junctions. To further study this process, recovery of barrier function was assessed in wild-type (NHE2+/+) and NHE2−/− mice in vivo and wild-type mice in vitro. Mice were subjected to complete mesenteric ischemia in vivo, after which barrier function was measured by blood-to-lumen mannitol clearance over a 3-h recovery period or measurement of transepithelial electrical resistance (TER) in Ussing chambers immediately following ischemia. Tissues were assessed for expression of select junctional proteins. Compared with NHE2+/+ mice, NHE2−/− mice had greater intestinal permeability during the postischemic recovery process. In contrast to prior porcine studies, pharmacological inhibition of NHE2 in postischemic tissues from wild-type mice also resulted in significant reductions in TER. Mucosa from NHE2−/− mice displayed a shift of occludin and claudin-1 expression to the Triton-X-soluble membrane fractions and showed disruption of occludin and claudin-1 localization patterns following injury. This was qualitatively and quantitatively recovered in NHE2+/+ mice compared with NHE2−/− mice by the end of the 3-h recovery period. Serine phosphorylation of occludin and claudin-1 was downregulated in NHE2−/− postischemia compared with wild-type mice. These data indicate an important role for NHE2 in recovery of barrier function in mice via a mechanism involving tight junctions.
Diabetes induces pulmonary artery endothelial dysfunction by NADPH oxidase induction
Authors: Lopez-Lopez Jose G. , Moral-Sanz Javier , Frazziano Giovanna , Gomez-Villalobos Maria J. , Flores-Hernandez Jorge , Monjaraz Eduardo , Cogolludo Angel , Perez-Vizcaino Francisco
Published: August 2008

Recent data suggest that diabetes is a risk factor for pulmonary hypertension. The aim of the present study was to analyze whether diabetes induces endothelial dysfunction in pulmonary arteries and the mechanisms involved. Male Sprague-Dawley rats were randomly divided into a control (saline) and a diabetic group (70 mg/kg−1 streptozotocin). After 6 wk, intrapulmonary arteries were mounted for isometric tension recording, and endothelial function was tested by the relaxant response to acetylcholine. Protein expression and localization were measured by Western blot and immunohistochemistry and superoxide production by dihydroethidium staining. Pulmonary arteries from diabetic rats showed impaired relaxant response to acetylcholine and reduced vasoconstrictor response to the nitric oxide (NO) synthase inhibitor l-NAME, whereas the response to nitroprusside and the expression of endothelial NO synthase remained unchanged. Endothelial dysfunction was reversed by addition of superoxide dismutase or the NADPH oxidase inhibitor apocynin. An increase in superoxide production and increased expression of the NADPH oxidase regulatory subunit p47phox were also found in pulmonary arteries from diabetic rats. In conclusion, the pulmonary circulation is a target for diabetes-induced endothelial dysfunction via enhanced NADPH oxidase-derived superoxide production.
Localization of phosphatidylinositol phosphate kinase IIγ in kidney to a membrane trafficking compartment within specialized cells of the nephron
Authors: Clarke Jonathan H. , Emson Piers C. , Irvine Robin F.
Published: August 2008

PIP4Ks (type II phosphatidylinositol 4-phosphate kinases) are phosphatidylinositol 5-phosphate (PtdIns5P) 4-kinases, believed primarily to regulate cellular PtdIns5P levels. In this study, we investigated the expression, localization, and associated biological activity of the least-studied PIP4K isoform, PIP4Kγ. Quantitative RT-PCR and in situ hybridization revealed that compared with PIP4Kα and PIP4Kβ, PIP4Kγ is expressed at exceptionally high levels in the kidney, especially the cortex and outer medulla. A specific antibody was raised to PIP4Kγ, and immunohistochemistry with this and with antibodies to specific kidney cell markers showed a restricted expression, primarily distributed in epithelial cells in the thick ascending limb and in the intercalated cells of the collecting duct. In these cells, PIP4Kγ had a vesicular appearance, and transfection of kidney cell lines revealed a partial Golgi localization (primarily the matrix of the cis-Golgi) with an additional presence in an unidentified vesicular compartment. In contrast to PIP4Kα, bacterially expressed recombinant PIP4Kγ was completely inactive but did have the ability to associate with active PIP4Kα in vitro. Overall our data suggest that PIP4Kγ may have a function in the regulation of vesicular transport in specialized kidney epithelial cells.
BH3-only protein mimetic obatoclax sensitizes cholangiocarcinoma cells to Apo2L/TRAIL-induced apoptosis
Authors: Mott Justin L. , Bronk Steve F. , Mesa Ruben A. , Kaufmann Scott H. , Gores Gregory J.
Published: August 2008

Human cholangiocarcinomas evade apoptosis by overexpression of Mcl-1. The drug obatoclax (GX15-070) inhibits antiapoptotic members of the Bcl-2 family including Mcl-1. The purpose of this study is to determine if obatoclax sensitizes human cholangiocarcinoma cells to apoptosis. The human cholangiocarcinoma cell lines, KMCH, KMBC, and TFK, were employed for these studies. Protein expression was assessed by immunoblot and protein-protein interactions detected by coprecipitation of the polypeptide of interest with S-tagged Mcl-1. Activation of Bak and Bax was observed by immunocytochemistry with conformation-specific antisera. Obatoclax induced minimal apoptosis alone; however, it increased apoptosis 3- to 13-fold in all three cancer cell lines when combined with Apo2L/tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Obatoclax did not alter cellular expression of Bid, Bim, Puma, Noxa, Bak, Bax, Mcl-1, or cFLIP. Mcl-1 binding to Bak was readily identified in untreated cells, and this association was disrupted by treating the cells with obatoclax. Additionally, Bim binding to Mcl-1 was markedly decreased by obatoclax treatment. We also identified alterations in Bak and Bax conformation following treatment with obatoclax plus Apo2L/TRAIL but not with either Apo2L/TRAIL or obatoclax alone. In conclusion, obatoclax releases Bak and Bim from Mcl-1 and sensitizes human cholangiocarcinoma cells to Apo2L/TRAIL-induced apoptosis. Obatoclax is a potentially promising adjunctive agent for the treatment of this cancer. [Mol Cancer Ther 2008;7(8):2339–47]
Anti-CD30 diabody-drug conjugates with potent antitumor activity
Authors: Kim Kristine M. , McDonagh Charlotte F. , Westendorf Lori , Brown Lindsay L. , Sussman Django , Feist Tiffany , Lyon Robert , Alley Stephen C. , Okeley Nicole M. , Zhang Xinqun , Thompson Melissa C. , Stone Ivan , Gerber Hans-Peter , Carter Paul J.
Published: August 2008

Anti-CD30 diabodies were engineered with two cysteine mutations for site-specific drug conjugation in each chain of these homodimeric antibody fragments. Diabodies were conjugated with ∼4 equivalents of the anti-tubulin drugs, monomethyl auristatin E or F, via a protease-cleavable dipeptide linker, to create the conjugates, diabody-vcE4 and diabody-vcF4, respectively. Diabody conjugation had only minor (<3-fold) effects on antigen binding. Diabody-vcF4 was potently cytotoxic against the antigen-positive cell lines, Karpas-299 (34 pmol/L IC50) and L540cy (22 pmol/L IC50), and was 8- and 21-fold more active than diabody-vcE4 against these cell lines, respectively. Clearance of diabody-vcF4 (99-134 mL/d/kg) was 5-fold slower than for the nonconjugated diabody in naive severe combined immunodeficient mice. Diabody-vcF4 had potent and dose-dependent antitumor activity against established Karpas-299 xenografts and gave durable complete responses at well-tolerated doses. Biodistribution experiments with diabody-[3H]-vcF4 (0.72-7.2 mg/kg) in tumor-bearing mice showed a dose-dependent increase in total auristatin accumulation in tumors (≤520 nmol/L) and decrease in relative auristatin accumulation (≤8.1 %ID/g), with peak localization at 4 to 24 h after dosing. Diabody-vcF4 had ∼4-fold lower cytotoxic activity than the corresponding IgG1-vcF4 conjugate in vitro. A similar potency difference was observed in vivo despite 25- to 34-fold faster clearance of diabody-vcF4 than IgG1-vcF4. This may reflect that dose-escalated diabody-vcF4 can surpass IgG1-vcF4 in auristatin delivery to tumors, albeit with higher auristatin exposure to some organs including kidney and liver. Diabody-drug conjugates can have potent antitumor activity at well-tolerated doses and warrant further optimization for cancer therapy. [Mol Cancer Ther 2008;7(8):2486–97]
Long-Term Assessment of Electrocardiographic and Echocardiographic Findings in Norwegian Elite Endurance Athletes
Authors: Bjørnstad Hans H. , Bjørnstad Tor H. , Urheim Stig , Hoff Per Ivar , Smith Gunnar , Maron Barry J.
Published: August 2008

Objectives: The long-term outcome and clinical significance of athlete’s heart has been debated and more longitudinal data are needed. We present a prospective 15 years’ follow-up study of ECG and echo findings in elite endurance athletes following the end of their competitive career. Methods: Clinical evaluation, ECG, ambulatory Holter recording and echocardiography were performed in 30 top-level endurance athletes with a mean age of 24 years with follow-up 15 years later. All had then ended their competitive career, but still performed recreational sports activities. Results: No clinical events were reported. Average resting heart rate was unchanged (53.5 ± 10 at baseline and 55.4 ± 11 at follow-up, p = n.s.), complex ventricular arrhythmias did not occur and the number of ventricular premature beats (VPBs) were 0.4 ± 0.8/h at baseline and 3.8 ± 10/h at follow-up (p = n.s.). In a subgroup of 4 subjects with >100 VPBs per hour at follow-up left ventricular mass was increased compared to the others (p < 0.03). Furthermore, regression of sino-atrial (SA) and atrioventricular (AV) blocks was shown. There were no cases of atrial flutter or fibrillation. There was a slight reduction in mean left ventricular wall thickness (9.9 ± 1.2 vs. 9.5 ± 1.4 mm, p < 0.05) and a highly significant reduction of relative wall thickness (0.38 vs. 0.35, p < 0.001). Left ventricular end-diastolic volume (68 ± 6 vs. 70 ± 7 ml ml/m2, p = n.s.) and left ventricular mass (109 ± 19 vs. 107 ± 19 g/m2, p = n.s.) were unchanged when corrected for body surface area and ejection fraction (EF) increased (60 ± 7 vs. 67 ± 6%, p < 0.01). Parameters of left ventricular diastolic function were normal both at baseline and follow-up. Conclusions: There was no evidence of deleterious cardiac effects of previous top-level endurance athletic activity at 15 years’ follow-up.
Changes in RANTES and β-Thromboglobulin after Intensive Exercise in Patients with Allergic Asthma
Authors: Zietkowski Z. , Bodzenta-Lukaszyk A. , Tomasiak M.-M. , Skiepko R. , Mroczko B. , Szmitkowski M.
Published: August 2008

Background: There is increasing evidence that exercise-induced bronchoconstriction (EIB) is associated with eosinophilic airway inflammation. In the pathogenesis of EIB the role of chemokines – responsible for promoting the migration and activation of inflammatory cells – as well as blood platelets, a potential source of those chemokines, remains unclear. Methods: The study was conducted in a group of 19 asthmatics (11 with EIB, 8 without EIB) and 8 healthy volunteers. Changes in the plasma concentrations of RANTES and β-thromboglobulin (β-TG) induced by intensive exercise were determined. Moreover, the possible correlation of these measurements with the results of other tests used in the diagnosis of asthma as well as laboratory tests commonly associated with asthma were investigated. Results: A comparison of the concentrations of β-TG in all groups studied at rest did not reveal any significant differences. In all groups studied, 30 min after exercise elevated β-TG concentrations were observed; the most significant increase was revealed in asthmatics with EIB. The baseline concentrations of RANTES before exercise in both groups of asthmatics were significantly higher in comparison to the group of healthy volunteers. After exercise, in the group of patients with EIB, a significant increase in RANTES concentrations was observed. These changes correlated with an increase in other markers of airway inflammation 24 h after exercise. Conclusions: We suggest that platelet activation, resulting in elevated RANTES release, could be one of the factors responsible for the increase of airway inflammation observed in consequence of EIB in asthmatics.
Allergenicity of Sigma and Delta Class Glutathione S-Transferases from the German Cockroach
Authors: Jeong Kyoung Yong , Jeong Kyoung-jin , Yi Myung-hee , Lee Haeseok , Hong Chein-Soo , Yong Tai-Soon
Published: August 2008

Background: Cockroach glutathione S-transferases (GSTs) are known to elicit strong IgE responses. This study was undertaken to compare the IgE reactivity of German cockroach GSTs, Bla g 5 (σ class) and δ class GST (BgGSTD1). Methods: Full-length Bla g 5 and BgGSTD1 were cloned, and their recombinant proteins were expressed and purified. Their IgE reactivities and cross-reactivities were examined by ELISA using sera from cockroach-sensitized subjects. Results: A predominant variant of Bla g 5 cDNA has amino acid substitutions at positions 10 (C to F) and 42 (N to K). BgGSTD1 has substitutions at positions 27 (E to N) and 207 (K to R). Sera from cockroach-sensitized patients showed 20.5% IgE reactivity to Bla g 5 and 17.9% IgE reactivity to BgGSTD1. However, inhibition studies using 1 serum sample with the highest IgE reactivity showed limited cross-reactivity. Conclusions: IgE-binding frequency to the cockroach GSTs was low, but the titer of IgE reactivity was strong in some sera. The inclusion of different classes of GSTs could be helpful for the delicate diagnosis and immunotherapy of cockroach allergy.
Durable Remission of Sézary Syndrome after Unrelated Bone Marrow Transplantation by Reduced-Intensity Conditioning
Authors: Kahata Kaoru , Hashino Satoshi , Takahata Mutsumi , Fujisawa Fumie , Kondo Takeshi , Kobayashi Sumiko , Fujita Yasuyuki , Shimizu Hiroshi , Imamura Masahiro , Asaka Masahiro
Published: August 2008

A 22-year-old Japanese man was diagnosed with Sézary syndrome with large cell transformation. His skin lesions persisted after treatment with 7 cycles of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone), psoralen and ultraviolet light A, and total skin electron beam irradiation. He subsequently underwent allogeneic bone marrow transplantation by reduced-intensity conditioning from a human leukocyte antigen-identical unrelated donor. He developed grade II of acute graft-versus-host disease and extensive-type chronic graft-versus-host disease. He has no signs of disease 36 months after the transplantation. The prognosis of patients with advanced stage of mycosis fungoides or Sézary syndrome is very poor. Allogeneic hematopoietic stem cell transplantation, especially by reduced-intensity conditioning, is expected to become a curative treatment option, and graft-versus-tumor effect might play a critical role for sustained remission.