bluuebunny/crossref_metadata_2025 huggingface dataset:
Allergic manifestations in patients with rheumatoid arthritis
Authors: OLSSON ÅSA RECKNER , WINGREN GUN , SKOGH THOMAS , SVERNELL OLLE , ERNERUDH JAN
Published: October 2003

A functional dichotomy between Th1‐ and Th2‐type immune responses has been suggested. This study was performed to investigate whether rheumatoid arthritis (RA), a disease with indications of Th1‐deviated immune activation, is inversly related to atopic conditions which are Th2‐mediated. Two hundred and sixty‐three adult cases of RA, fulfilling the American Rheumatism Association (ARA) 1987 Revised Classification Criteria for RA, were identified in 1995 and compared with 541 randomly selected population referents. The presence of atopic manifestations was established through a postal questionnaire and by demonstrating circulating IgE antibodies to common allergens. RA was inversely associated with certain manifestations of rhinitis, which were regarded as the most reliable indicators of atopic disease in the present study. However, no negative association was seen between RA and asthma and eczema, respectively. The main results give some support for an inverse relationship between RA and rhinitis. The prevalence of circulating IgE antibodies was however similar in cases and controls, suggesting that the T‐cell commitment mainly occurs in the affected organs.
Serologically indicated pneumococcal pneumonia in children: a population‐based study in primary care settings
Authors: HEISKANEN‐KOSMA TARJA , KORPPI MATTI , LEINONEN MAIJA
Published: October 2003

The aim of the study was to assess age‐specific incidences of community‐acquired pneumonia (CAP) caused by Streptococcus pneumoniae and diagnosed serologically in a child population. The study was population‐based, and prospective, and performed in primary health care settings. During a surveillance period of 12 months from 1981–1982, all pneumonia cases in a defined child population (57% urban residents) were registered prospectively. In total, 201 CAP cases were diagnosed (mean age 5.6 years; 57% boys; 58% urban residents). S. pneumoniae etiology was studied by antibody and immune complex (IC) assays to C‐polysacchride (C‐PS), type‐specific capsular polysaccharides (CPS), and to pneumolysin (Ply), in acute and convalescent sera. Serologic evidence of S. pneumoniae etiology was indicated in 57(28%) cases, 35(61%) being mixed infections with other microbes. The distribution of pneumococcal cases was 44%, 30% and 26% in the three 5‐year age groups, respectively. There were 33 (58%) males and 34 (60%) urban residents. In total, 26 cases were identified by antibody assays and 35 cases by IC assays, 26/35 being positive in acute sera. Responses to C‐PS, CPS and Ply, when antibody and IC results are combined, were found equally often in 23–25 cases. The total annual incidence of pediatric S. pneumoniae CAP was 6.4/1000/year. S. pneumoniae etiology was found in 28% of the children and was similar at all ages. The incidence of pneumococcal CAP was assessed for the first time, being high (19/1000/year) in 0‐ to 4‐year‐old urban boys and rather stable (5–9/1000/year) in all other groups by age, sex and residence.
Role of group A streptococcal IgG‐binding proteins in triggering experimental glomerulonephritis in the rabbit
Authors: BUROVA LARISSA , THERN ANETTE , PIGAREVSKY PITER , GLADILINA MARIA , SELIVERSTOVA VALENTINA , GAVRILOVA ELENA , NAGORNEV VLADIMIR , SCHALÉN CLAES , TOTOLIAN ARTEM
Published: October 2003

Our previous studies have indicated that the IgG‐binding M‐family proteins (IgGBP) of group A streptococci may be involved in eliciting experimental acute poststreptococcal glomerulonephritis (APSGN) in the rabbit. These surface proteins were also found to trigger production of anti‐IgG, which might conceivably act to enhance renal deposition of immune complexes (IC). In the present study, a clinical isolate of serotype M22 (strain AL168), an isogenic double mutant deficient for both the IgGBPs Mrp and Emm, as well as mutants deficient in only one of the proteins were tested for capacity to induce glomerulonephritis. Streptococci to be used for injecting rabbits were heat‐killed. Surface‐bound IgG was removed by 1 M KSCN and cells were then repeatedly washed in PBS before use. Rabbits were injected intravenously with 109 cells three times a week for 8 weeks and, following one month of rest, for another 6 weeks. Deposits of IgG and C3 as well as induced chemokines TNF‐α, IL‐1β and IL‐6 were traced in cryostat sections using specific antibodies and appropriate peroxidase‐labelled anti‐antibodies. In four rabbits immunized with the double mutant strain, no deposits were found, and as examined by TEM, only subtle and transient renal changes were observed. In contrast, the original strain AL168 induced pronounced inflammatory and degenerative glomerular changes in all four rabbits injected, and deposits of TNF‐α, IL‐1β and IL‐6 were found in mesangial and endothelial cells. Similar deposits and glomerular changes were seen in all eight rabbits injected with the mrp−emm+ mutant and in four out of seven animals receiving the mrp+emm− mutant. There was a highly significant correlation between high levels of circulating anti‐IgG and development of APSGN. These results confirm an important role of streptococcal IgGBP in triggering experimental APSGN as earlier proposed by our group.
Inducible nitric oxide synthase (NOS II) is constitutive in human neutrophils
Authors: CEDERGREN JAN , FOLLIN PER , FORSLUND TONY , LINDMARK MARIA , SUNDQVIST TOMMY , SKOGH THOMAS
Published: October 2003

The objective was to study the expression of inducible nitric oxide synthase (NOS II) in and NO production by human blood neutrophils and in in vivo exudated neutrophils. Cellular expression of NOS II was evaluated by flow cytometry in whole blood, in isolated blood neutrophils, and in neutrophils obtained by exudation in vivo into skin chambers. Neutrophil NOS II was also demonstrated by Western blotting. Uptake of 3H‐labelled L‐arginine was studied in vitro and NOS activity measured in a whole cell assay by the conversion of 3H‐arginine to 3H‐citrulline. In contrast to unseparated blood cells, NOS II was demonstrable both in isolated blood neutrophils and exudated cells. The failure to detect NOS II by flow cytometry in whole blood cells thus proved to be due to the quenching effect of hemoglobin. Western blotting revealed a 130 kD band corresponding to NOS II in isolated blood neutrophils, but detection was dependent on diisopropylfluorophosphate for proteinase inhibition. L‐arginine was taken up by neutrophils, but enzymatic activity could not be demonstrated. We conclude that human neutrophils constitutively express NOS II, but that its demonstration by FITC‐labelling is inhibited by hemoglobin‐mediated quenching in whole blood samples.
MUC1 and MUC2 expression in salivary gland tumors and in non‐neoplastic salivary gland tissue
Authors: MANNWEILER SEBASTIAN , BEHAM ALFRED , LANGNER CORD
Published: October 2003

The expression of MUC1 and MUC2 was studied in salivary gland tumors and non‐neoplastic salivary gland tissue. Formalin‐fixed paraffin‐embedded specimens from 101 patients (21 pleomorphic adenomas (PA), 22 Warthin's tumors (WT), 26 adenoid cystic carcinomas (ACC), 13 acinic cell adenocarcinomas (ACA), 9 mucoepidermoid carcinomas (MC), and 10 specimens of non‐neoplastic parotid and submandibular gland tissue) were immunostained. All salivary gland tumors expressed MUC1. A strong immunoreactivity was noted in WT and MC, a moderate in ACC and ACA, and a weak in PA. Strong expression of MUC2 was noted in all WT, moderate expression in MC, and weak expression in PA and ACA. All cases of ACC except for two were negative for MUC2. In general, MUC1 expression was stronger than that of MUC2. Non‐neoplastic salivary gland tissue revealed a moderate MUC1 and MUC2 expression in excretory ducts and a strong expression in striated ducts. The apical plasma membrane of some serous acini expressed MUC1. Mucous acini were negative for both antigens. No change in immunoreactivity was noted in cases of chronic sclerosing sialadenitis. In conclusion, the different expression pattern of MUC1 and MUC2 in salivary gland neoplasia may be of additional value for the classification of salivary gland tumors.
Food‐induced antisecretory factor activity is correlated with small bowel length in patients with intestinal resections
Authors: LANGE STEFAN , BOSAEUS INGVAR , JENNISCHE EVA , JOHANSSON EWA , LUNDGREN BIRGITTA K. , LÖNNROTH IVAR
Published: October 2003

Specially processed cereals (SPC) can increase antisecretory factor (AF) activity in humans with an intact intestine. The aim of the present study was to investigate whether AF synthesis could be induced in patients who had been subjected to intestinal resections. Eight patients with varying extents of intestinal resections due to Crohn's disease and six healthy controls participated. All subjects received 54 g SPC daily for 2 weeks. Plasma AF activity was determined before, during and after the treatment period. Baseline diet and medications were kept unchanged. The patients registered the daily number of bowel movements. The SPC diet increased AF activity in all controls. In the patients there was a significant correlation between the length of the remaining small intestine and AF induction (r=0.94, p<0.01) and only those patients with a remaining small intestine of about 3 m reached AF values comparable to those in healthy subjects. It is concluded that small bowel length is related to the ability of humans to induce AF activity by dietary means.
Compass orientation and possible migration routes of passerine birds at high arctic latitudes
Authors: Muheim Rachel , Åkesson Susanne , Alerstam Thomas
Published: October 2003

The use of celestial or geomagnetic orientation cues can lead migratory birds along different migration routes during the migratory journeys, e.g. great circle routes (approximate), geographic or magnetic loxodromes. Orientation cage experiments have indicated that migrating birds are capable of detecting magnetic compass information at high northern latitudes even at very steep angles of inclination. However, starting a migratory journey at high latitudes and following a constant magnetic course often leads towards the North Magnetic Pole, which means that the usefulness of magnetic compass orientation at high latitudes may be questioned. Here, we compare possible long‐distance migration routes of three species of passerine migrants breeding at high northern latitudes. The initial directions were based on orientation cage experiments performed under clear skies and simulated overcast and from release experiments under natural overcast skies. For each species we simulated possible migration routes (geographic loxodrome, magnetic loxodrome and sun compass route) by extrapolating from the initial directions and assessing a fixed orientation according to different compass mechanisms in order to investigate what orientation cues the birds most likely use when migrating southward in autumn. Our calculations show that none of the compass mechanisms (assuming fixed orientation) can explain the migration routes followed by night‐migrating birds from their high Nearctic breeding areas to the wintering sites further south. This demonstrates that orientation along the migratory routes of arctic birds (and possibly other birds as well) must be a complex process, involving different orientation mechanisms as well as changing compass courses. We propose that birds use a combination of several compass mechanisms during a migratory journey with each of them being of a greater or smaller importance in different parts of the journey, depending on environmental conditions. We discuss reasons why birds developed the capability to use magnetic compass information at high northern latitudes even though following these magnetic courses for any longer distance will lead them along totally wrong routes. Frequent changes and recalibrations of the magnetic compass direction during the migratory journey are suggested as a possible solution.
A review of long‐distance movements by marine turtles, and the possible role of ocean currents
Authors: Luschi Paolo , Hays Graeme C. , Papi Floriano
Published: October 2003

Sea turtle movements often occur in open‐sea unsheltered areas, and are therefore likely to be influenced by major oceanographic processes. Only recently has work started to examine the possible relationships of these movements with dynamic oceanic features, and consequently a clear picture of such interaction is only available in a few cases.

Newborn sea turtles are thought to rely on oceanic currents to reach their pelagic nursery habitats. The actual extent and timing of these developmental migrations are known for only a few populations, but these movements probably last several years and range over thousands of km. Large juveniles that have been tracked during their pelagic stage were found to make long‐distance movements, sometimes swimming against the prevailing currents. Older juveniles of most species leave the pelagic habitat to recruit to neritic developmental habitats. This is a very poorly documented phase of the sea turtle life‐cycle, and the few available indications show that turtles may have to swim actively for enormous distances to counterbalance their previous drift with the current.

The course and extent of adult postnesting migrations vary greatly among different turtle species, but two main patterns are evident. Some species, like green, hawksbill and loggerhead turtles, shuttle between the nesting beach and a specific feeding area used for the entire inter‐reproductive period. In these cases, individuals swim, rather than drift, to complete their journeys, with possible advection due to currents sometimes helping them to quickly reach their target, but sometimes providing navigational challenges.

Other species such as the olive ridley and the leatherback turtle, leave the coastal nesting areas to reach the pelagic environment where they forage, and perform wandering movements. Major oceanographic processes (such as main currents and eddies) have been recently shown to have a remarkable influence on leatherback movements, making it questionable whether these journeys are to be considered migrations or, rather, prolonged stays in vast feeding areas.
Burning the engine: a time‐marching computation of fat and protein consumption in a 5420‐km non‐stop flight by great knots, Calidris tenuirostris
Authors: Pennycuick C. J. , Battley Philip F.
Published: October 2003

Samples of great knots (Calidris tenuirostris) were collected in an earlier project, before and after a 5420‐km migration stage from Australia to China (believed to be flown non‐stop) to determine the mass of fat consumed, and also the mass of protein withdrawn from the flight muscles and other organs. The flight was simulated by a “time‐marching” computation, which calculated the fuel energy required, and allowed different hypotheses to be tried for the consumption of protein. The simulation predicted that the great knots would take about 4 days to cover the distance, in agreement with field estimates. Realistic predictions of the consumption of fat and protein were obtained by setting the conversion efficiency to 0.23 and the body drag coefficient to 0.10, withdrawing sufficient protein from the flight muscles to keep the specific work in the myofibrils constant throughout the flight, and taking enough additional protein from other tissues to bring the energy derived from oxidising protein to 5% of the total energy consumed.

The same computation was applied to published data on the pre‐migration body composition of bar‐tailed godwits (Limosa lapponica), which are said to migrate over 10 000 km from Alaska to New Zealand. The computed range for a sample killed by collision with an obstruction, while actually departing from Alaska, was sufficient to reach the South Pole. A second sample, shot before departure from New Zealand, would have run out of fat before reaching Alaska, but could easily have reached northern Australia, where these godwits stage on their northbound migration. The higher range estimate for the Alaskan birds was not due to higher fat mass (only 5% difference) but to a higher fat fraction, which they had achieved by reducing the mass of other organs before departure.

Some recent observations of high chemical power, observed in wind tunnel experiments, have been interpreted as being due to much lower conversion efficiency than the value of 0.23 assumed here, but this interpretation is flawed. Measurements of mechanical power from another wind tunnel project were also unexpectedly high, suggesting that unsteady flight by wind tunnel birds increases their power requirements, both mechanical and chemical, with no implications for efficiency. The calculated power is for “steady horizontal flight”, meaning that a valid test of predicted power requires birds to be trained to hold a constant position in the test section, while maintaining a steady wingbeat frequency and amplitude. This has not been achieved in recent experiments, and is hard to achieve when using physiological methods, because of the long periods of continuous flight needed. Measurements of mechanical rather than chemical power require shorter flight times, and offer better prospects for reliable power measurements.
Can vector summation describe the orientation system of juvenile ospreys and honey buzzards? – An analysis of ring recoveries and satellite tracking
Authors: Thorup Kasper , Alerstam Thomas , Hake Mikael , Kjellén Nils
Published: October 2003

Juvenile bird migrants are generally believed to use a clock‐and‐compass migratory orientation strategy. According to such a strategy migrants accomplish their migration by flying a number of successive flight steps with direction and number of steps controlled by an endogenous programme. One powerful way of testing this is by comparing predictions from a model of such a strategy with observed patterns. We used data from ringing and satellite‐based radio telemetry to investigate the orientation system of juvenile ospreys (Pandion haliaetus) and honey buzzards (Pernis apivorus) migrating from Sweden to tropical west Africa. The ring recoveries showed a much larger scatter in the orientation of ospreys than of honey buzzards, but there was only a slight such difference in the satellite tracks. These tracks of individuals of both species were rather straight with a high directional concentration per step. The honey buzzard data showed a close fit to a simple vector summation model, which is expected if birds follow a clock‐and‐compass strategy. However, the osprey data did not fit such a simple model, as ring recoveries showed a significantly greater deviation at short distances than predicted on the basis of long distance data. Satellite tracking also indicated less concentrated orientation on short distances. The pattern observed for the osprey can generally be explained by an extended vector summation model, including an important element of pre‐migration dispersal. The existence of extensive dispersal in the osprey stands in contrast to the apparent absence of such dispersal in the honey buzzard. The explanation for this difference between the species is unclear. The model of orientation by vector summation is very sensitive to the existence of differences in mean direction between individuals. Assuming such differences, as tentatively indicated by the satellite tracking data, makes simple compass orientation by vector summation inconsistent with the distribution of ring recoveries at long distances, with a high proportion of misoriented birds falling outside the normal winter range.
How does a first year passerine migrant find its way? Simulating migration mechanisms and behavioural adaptations
Authors: Erni Birgit , Liechti Felix , Bruderer Bruno
Published: October 2003

In the Palaearctic‐African migration system, birds face several trade‐offs on their first autumn migration. The shortest route, minimising travelling time, would lead them directly south across the Mediterranean Sea and the Sahara Desert, involving long stretches of no refuelling possibilities. This route is risky because of flight range constraints. Besides taking longer, a detour along the Iberian peninsula may require a more complex orientation mechanism. We simulated migrants with stopover and orientation behaviour and investigated the effect of flight costs and behavioural rules (e.g. crossing or flying along coast lines, a shift in migratory direction) on the resulting flight path and especially on the evolution of endogenous directions. The simulation of autumn migration from southern Scandinavia to south of the Sahara showed that it would be possible to reach the winter quarters by vector summation with a constant endogenous direction, but then either orientation must be very accurate or flight costs must be small. For small passerines both requirements are so far not corroborated by empirical studies. Alternatively, flying along coast lines or shifting direction in northern Africa from south‐westerly to southerly, resulted in similar survival rates as with a constant south‐westerly endogenous direction, but with a larger range of feasible values. Although weather factors were not included, our results suggest that the Mediterranean Sea and the Sahara desert had a dominating influence on the evolution of endogenous directions. This influence is probably acting through flight range constraints.
Environmental heterogeneity and the evolution of foraging behaviour in long ranging greater albatrosses
Authors: Waugh Susan M. , Weimerskirch Henri
Published: October 2003

Habitat selection in heterogeneous environments is assumed to allow diversification. Wide‐ranging species like pelagic seabirds present a paradox, in that their diversity appears difficult to reconcile with a frequent lack of geographical isolation between populations. We studied the foraging strategies of three closely related species of greater albatrosses, wandering albatross, Diomedea exulans, Amsterdam albatrosses D. amsterdamensis and royal albatross, D. epomophora, in relation to environmental heterogeneity at coarse‐grained and fine‐grained scales. During the incubation period the three species foraged at long distances from their colonies. We observed significant differences between the species in the duration of foraging trips and the distance travelled per day. There were significant differences in preference for habitat types in relation to bathymetric features, and in chlorophyll a concentrations in the waters traversed. Royal albatross preferred shallower waters (<1500 m depth), which were rich in chlorophyll (>0.5 mg/m3), while the other species spent on average 80% of their time in waters deeper than this, where chlorophyll levels were lower. Wandering albatrosses foraged in colder waters than Amsterdam albatrosses. Patterns of activity divided the species into two groups: those exploiting oceanic habitats (wandering and Amsterdam albatrosses) spent high proportions of time on the water (49%), and had on average 1.35 takeoffs and landings per hour, while royal albatross, which foraged mainly over neritic waters spent only 35% of their time sitting on the water, and made on average 2.6 takeoff per hour. Further, royal albatross showed a similar pattern of activity during all periods of the day, while wandering and Amsterdam albatrosses were mostly inactive during the night. We link these differences in activity to prey patch availability in two contrasting habitats – continental shelf areas compared to open ocean habitats. The divergent styles of foraging observed in this study suggest that these closely‐related and wide‐ranging species could effectively co‐exist by dividing the resources available to them by different modes of exploitation.
Gluttony in migratory waders – unprecedented energy assimilation rates in vertebrates
Authors: Kvist Anders , Lindström Åke
Published: October 2003

Maximum energy assimilation rate has been implicated as a constraint on maximal sustained energy expenditure, on biomass production, and in various behavioural and life history models. Data on the upper limit to energy assimilation rate are scarce, and the factors that set the limit remain poorly known. We studied migratory waders in captivity, given unlimited food supply around the clock. Many of these waders assimilated energy at rates of seven to ten times basal metabolism, exceeding maximum rates reported for vertebrates during periods of high energy demand, for example during reproduction and in extreme cold. One factor allowing the high energy assimilation rates may be that much of the assimilated energy is stored and not concomitantly expended by muscles or other organs. The remarkable digestive capacity in waders is probably an adaptation to long and rapid migrations, putting a premium on high energy deposition rates. The upper limit to daily energy assimilation in vertebrates is clearly higher than hitherto believed, and food availability, total daily feeding time and, possibly, the fate of assimilated energy may be important factors to take into account when estimating limits to energy budgets in animals.
Effects of predation danger on migration strategies of sandpipers
Authors: Lank David B . , Butler Robert W . , Ireland John , Ydenberg Ronald C .
Published: October 2003

We examine the potential selective importance of predation danger on the evolution of migration strategies of arctic‐breeding calidrid sandpipers. Adult calidrids truncate parental care for reasons not obviously related to levels of food abundance on the breeding areas or at migratory stopover sites, suggesting that a different trade‐off occurs between providing additional care and adult survivorship. The southward migrations of adult western sandpipers precede those of migratory peregrine falcons by almost a month. By moving early and quickly, adults remain ahead of migrant falcons all the way to their non‐breeding areas, where they rapidly moult flight feathers. They complete the moult just as falcons arrive in late September–October. By migrating early, they avoid exposure to falcons when they are unusually vulnerable, due to the requirements for fuelling migratory flight and of wing feather moult. Juvenile western sandpipers migrate south just as falcon numbers start to increase, but do not moult flight feathers in their first winter. Pacific dunlin use an alternative strategy of remaining and moulting in Alaska after falcons depart, and migrating to their overwintering sites after migrants have passed. East of the Rocky Mountains, the southbound migration of falcons begins 4–6 weeks later. Southbound semipalmated sandpipers make extended migratory stopovers, but their lengths of stay shorten prior to falcon migration to the sites in September. Predation danger also may affect the evolution of migration routes. Southbound western sandpipers fly directly from Alaska to southern British Columbia, in contrast to the multi‐stage journey northward along the Alaska panhandle. We estimate that a direct flight would be more economical on northward migration, but may be avoided because it would expose sandpipers to higher mass‐dependent predation danger from migratory falcons, which travel north with sandpipers. By contrast, few raptors are present in Alaska during preparation for the southward flight. A temporal and spatial window of safety may also permit semipalmated sandpipers to become extremely vulnerable while preparing for trans‐Atlantic southward flights. Danger management may account for the these previously enigmatic features of calidrid migration strategies, and aspects of those of other birds.
Energy limitations for spring migration and breeding: the case of brent geeseBranta berniclatracked by satellite telemetry to Svalbard and Greenland
Authors: Clausen Preben , Green Martin , Alerstam Thomas
Published: October 2003

Brent geese were tracked by satellite telemetry from spring staging areas in Denmark to Arctic breeding areas in Svalbard and Greenland in 1997 and 2001. From estimated departure masses and carcass analysis we used flight mechnical theory to estimate maximum flight ranges of both sexes, and remaining stores of fat and protein upon arrival in females. Model predictions suggested that all birds but one exceptionally thin male could easily reach Svalbard, but that approximately one third of the males and half of the females would have problems with flying to Greenland. Nevertheless, some birds even flew longer than the models predicted. In addition, females predicted to be capable of making the flight to Greenland, were predicted to arrive almost lean of fat. This contradicts our expectation that these birds are capital breeders – that they depend on endogenous stores of fat and protein when initiating and incubating their eggs. We discuss how the Greenland breeding sub‐population during 1985–1998 has been able to grow at the same rate as the sub‐population breeding in Svalbard, despite the added flight distance of 700–1000 km, and despite the birds predicted shortage of fat stores on arrival. We suggest four hypotheses that alone or in combination could explain the discrepancy between model predictions and observations. These are that most birds: (1) refuel on stop‐overs in Spitsbergen en route to Greenland; (2) pick favourable tail‐winds enabling them to reduce flight costs; (3) fly in formation and thereby save energy; and/or (4) undergo gut atrophy immediately prior to departure, and use the nutrients mobilised by catabolism of the digestive system to build larger pectoral muscles. The latter option would both reduce their airframe fraction, and increase their fat and flight‐muscle fractions, enabling them to fly longer. We conclude that the latter option seems less likely to operate in brent geese.
Long‐distance migration: evolution and determinants
Authors: Alerstam Thomas , Hedenström Anders , Åkesson Susanne
Published: October 2003

Long‐distance migration has evolved in many organisms moving through different media and using various modes of locomotion and transport. Migration continues to evolve or become suppressed as shown by ongoing dynamic and rapid changes of migration patterns. This great evolutionary flexibility may seem surprising for such a complex attribute as migration. Even if migration in most cases has evolved basically as a strategy to maximise fitness in a seasonal environment, its occurrence and extent depend on a multitude of factors. We give a brief overview of different factors (e.g. physical, geographical, historical, ecological) likely to facilitate and/or constrain the evolution of long‐distance migration and discuss how they are likely to affect migration. The basic driving forces for migration are ecological and biogeographic factors like seasonality, spatiotemporal distributions of resources, habitats, predation and competition. The benefit of increased resource availability will be balanced by costs associated with the migratory process in terms of time (incl. losses of prior occupancy advantages), energy and mortality (incl. increased exposure to parasites). Furthermore, migration requires genetic instructions (allowing substantial room for learning in some of the traits) about timing, duration and distance of migration as well as about behavioural and physiological adaptations (fuelling, organ flexibility, locomotion, use of environmental transport etc) and control of orientation and navigation. To what degree these costs and requirements put constraints on migration often depends on body size according to different scaling relationships. From this exposé it is clear that research on migration warrants a multitude of techniques and approaches for a complete as possible understanding of a very complex evolutionary syndrome. In addition, we also present examples of migratory distances in a variety of taxons. In recent years new techniques, especially satellite radio telemetry, provide new information of unprecedented accuracy about journeys of individual animals, allowing re‐evaluation of migration, locomotion and navigation theories.
Should Aspirin be Used to Counteract ‘Salicylate Deficiency’?
Authors: Morgan Gareth
Published: October 2003

Abstract: Aspirin (acetylsalicylate) is an inexpensive drug that is used extensively to reduce cardiovascular disease risk. Emerging evidence suggests that aspirin reduces the risk of other chronic diseases such as certain forms of cancer. Salicylate may contribute to the disease reduction effects. It is present naturally in fruits and vegetables and individuals with a low intake of these foods may be ‘salicylate deficient’. This deleterious state may constitute a significant public health threat. Interventions to prevent deficiency, such as low‐dose aspirin programmes, could have substantial beneficial health impacts around the world.
Kinetics of Inhibition of Glutamate Uptake by Antioestrogens
Authors: Mäenpää Hanna , Saransaari Pirjo , Tähti Hanna
Published: October 2003

Abstract:The antioestrogens, tamoxifen and its more recent homologue toremifene, are used in the therapy of breast cancer. Tamoxifen has been reported to cause retinal changes as side effects. Both compounds inhibited glutamate uptake in retinal pigment epithelial cells, and the present study was conducted to clarify the mechanism of this inhibition. Retinal pigment epithelial cells are part of the blood‐retina barrier, and their glutamate transporters are essential for retinal glutamate homeostasis. Glutamate uptake was investigated in human retinal pigment epithelial cell line D407 and in cultured pig retinal pigment epithelial cells using L‐[3H]glutamate as a tracer. The cells were exposed to 7.5 μM tamoxifen and toremifene. β‐Hydroxyaspartate, a transportable inhibitor of glutamate transport, was used as a reference compound. In kinetic analyses, β‐hydroxyaspartate increased the Kmconstant for glutamate transport. Tamoxifen and toremifene exhibited the same effect, which indicates that inhibition evoked by them is also competitive in nature. Both drugs were more effective in the human retinal pigment epithelial cell line than in the pig retinal pigment epithelial cells. The results show for the first time that the antioestrogens tamoxifen and toremifene could possibly hamper glutamate transport by replacing glutamate as the substrate.
Ascorbic Acid Supplementation Does Not Improve Efficacy of meso‐Dimercaptosuccinic Acid Treatment in Lead‐Exposed Suckling Rats
Authors: Varnai Veda Marija , Piasek Martina , Blanuša Maja , Jureša Dijana , Šarić Marija , Kostial Krista
Published: October 2003

Abstract: It was suggested that ascorbic acid as a natural chelating agent can influence lead toxicokinetics and improve chelating properties of dimercaptosuccinic acid (DMSA) in adult rats. In this paper potential benefits of ascorbic acid supplementation, alone or combined with DMSA, in decreasing lead retention in suckling rats were evaluated. Such data in young mammals are not available. L‐Ascorbic acid (daily dose 650 mg/kg b.wt.) and/or DMSA (daily dose 91 mg/kg b.wt.) were administered orally to suckling Wistar rats either during ongoing 8‐day oral lead exposure (as acetate; daily dose 2 mg lead/kg b.wt.) or after 3‐day lead exposure (total dose 12 mg lead/kg b.wt.). Lead concentrations were analysed in the carcass (skeleton), liver, kidneys and brain by atomic absorption spectrometry. By ascorbic acid supplementation lead retention was not reduced under either lead exposure condition. Lead concentration was even increased in the carcass. Treatment with DMSA under both exposure conditions significantly reduced lead in all analysed tissues. Combined treatment with ascorbic acid and DMSA during ongoing lead exposure was substantially less effective than DMSA treatment alone, and did not affect DMSA efficacy when administered after lead exposure. It was concluded that ascorbic acid administered either during or after lead exposure in suckling rats has no beneficial effect on either lead retention or DMSA chelation effectiveness.
2,3,7,8‐Tetrachlorodibenzo‐p‐dioxin (TCDD)‐Induced Activation of Mitogen‐Activated Protein Kinase Signaling Pathway in Jurkat T Cells
Authors: Kwon Myung‐Ja , Jeong Kyu‐Shik , Choi Eun Jeong , Lee Byung Ho
Published: October 2003

Abstract: The present study was performed to examine mitogen‐activated protein kinase associated pathways in mediation of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD)‐induced cell apoptosis in cultured Jurkat T cells. TCDD significantly decreased cell viability in a concentration‐dependent manner (P<0.05 at 10–300 nM). TCDD (10 nM) also time‐dependently decreased cell viability (P<0.05 at 12–48 hr). c‐Jun NH2‐terminal kinase was significantly phosphorylated with TCDD treatment in a time dependent manner. p38 Mitogen‐activated protein kinase was not significantly changed with TCDD treatment. Extracellular signal‐regulated protein kinase was significantly phosphorylated with TCDD treatment for 8 hr and gradually returned to baseline. TCDD induced up‐regulation of ASK1 and C‐Jun, which are up‐ and down‐stream of JNK, respectively, and up‐regulation of cytosolic cytochrome c and caspase‐3. These results demonstrate that MAPK signaling pathways including JNK and ERK 1/2, are activated with the treatment of TCDD in Jurkat T cells, which suggest that MAPK pathways may be involved in TCDD‐induced cell death.
Influence of the Murine Oestrous Cycle on the Induction of Mucosal Immunity
Authors: Gockel Christine M. , Bao Shisan , Holland Michael K. , Beagley Kenneth W.
Published: October 2003

Problem: To determine if the stage of oestrous cycle, at the time of immunization, affects the magnitude of mucosal and systemic immunity.

Method of study: Female BALB/c mice were immunized with tetanus toxoid and cholera toxin by the oral, intranasal and transcutaneous routes. Groups of mice were immunized at proestrus, oestrus, postestrus and diestrus. Antibodies in serum and mucosal secretions were determined by ELISA and T cell responses by lymphocyte proliferation assay.

Results: Oral immunization at the oestradiol dominant stage of cycle (oestrus and proestrus) significantly enhanced TT‐specific IgG and IgA levels in female reproductive tract (FRT) secretions and TT‐specific IgA levels in faecal extracts. Transcutaneous immunization at diestrus enhanced TT‐specific IgG in faecal extracts. TT‐specific T cell proliferation is greatest following intranasal immunization at proestrus and transcutaneous immunization at diestrus, particularly in the caudal and lumbar lymph nodes draining the FRT and colon.

Conclusions: Reproductive cycle‐associated changes in the endogenous sex hormones oestradiol and progesterone influence the levels of vaccine‐induced immunity in the FRT and distal colon following oral and transcutaneous immunization.
Actions of Tumor Necrosis Factor‐α on Oocyte Maturation and Embryonic Development in Cattle1
Authors: Soto P. , Natzke R. P. , Hansen P. J.
Published: October 2003

Problem:  Infertility can accompany mastitis in cattle. Involvement of tumor necrosis factor‐α (TNF‐α) in this phenomenon is suggested by observations that circulating concentrations of TNF‐α are elevated after intramammary infection or infusion of endotoxin. It was hypothesized that (1) TNF‐α acts on the oocyte during maturation to decrease the percent of oocytes that cleave and develop following fertilization; (2) exposure of embryos to TNF‐α after fertilization reduces development to the blastocyst stage; and (3) TNF‐α increases the proportion of blastomeres that undergo apoptosis in a stage‐of‐development dependent manner.

Method of study:  In one experiment, oocytes were matured with various concentrations of TNF‐α and then fertilized and cultured without TNF‐α. In another study, embryos were cultured with TNF‐α for 8 days beginning after fertilization. Finally, embryos were collected at the two or four‐cell stage (at 28–30 hr after insemination) or when ≥9‐cells (at day 4 after insemination) and cultured ± TNF‐α for 24 hr. The proportion of blastomeres undergoing apoptosis was then determined by the TUNEL procedure.

Results:  Addition of TNF‐α to maturation medium did not affect the proportion of oocytes that cleaved. However, the percent of oocytes that developed to the blastocyst stage at day 8 after insemination was reduced (P = 0.05) at all TNF‐α concentrations tested (0.1–100 ng/mL). When added during embryo culture, there was no significant effect of TNF‐α on the proportion of oocytes that became blastocysts. In addition, TNF‐α did not induce apoptosis in two and four‐cell embryos. For embryos ≥9‐cells, however, 10 and 100 ng/mL TNF‐α increased (P < 0.05) the percent of blastomeres labeling as TUNEL‐positive.

Conclusion:  TNF‐α can have deleterious actions on oocyte maturation that compromise development of the resultant embryo. While exposure of fertilized embryos to TNF‐α did not inhibit development to the blastocyst stage, TNF‐α increased the percentage of blastomeres undergoing apoptosis when exposure occurred for embryos ≥9‐cells. Increased blastomere apoptosis could conceivably compromise subsequent embryo survival.
COX‐2 expression in striated muscle under physiological conditions
Authors: Sudbø J , Reith A , Flørenes VA , Nesland JM , Ristimäki A , Bryne M
Published: October 2003

Objectives: The role of cyclooxygenase‐2 (COX‐2) in disease has been extensively studied, (Annu Rev Med (2002) 53:35; N Engl J Med (2001) 345:433) but less information is available with respect to possible physiological functions of COX‐2. Information on how and where COX‐2 is expressed under physiological conditions may increase our understanding of its physiological role. Previous studies have revealed a COX‐2 dependent production of prostanoids under physiological conditions, without entirely determining the source of this production.

Materials and methods: To assess COX‐2 expression under normal conditions, we analyzed tissue specimens that were removed from 30 healthy study subjects in conjunction with surgical procedure related to insertion of dental implants and from three patients which had muscle tissue from Quadriceps femoris muscle removed as part of surgical treatment of soft tissue sarcomas not directly affecting the muscle tissue. Immunohistochemistry and immunoblotting (Western blotting) was used to assess the presence of COX‐2 protein.

Results: In 25 of 30 patients (83%), COX‐2 protein was expressed in striated muscle, as assessed by immunohistochemistry. All cases had COX‐2 expression verified by Western blotting. In none of the 25 subjects with COX‐2 expression did we notice concomitant inflammation of the adjacent submucosal tissue.

Conclusions: It is a novel finding that COX‐2 is expressed in striated muscle under physiological conditions. COX‐2 activity in striated muscle is a possible explanation for the hitherto unknown localization of prostanoids synthesis under physiological conditions.
Prevalence of oral leukoplakia and lichen planus in 1167 Iranian textile workers
Authors: Jahanbani J
Published: October 2003

Objective:  To evaluate the prevalence of oral precancerous lesions in textile workers.

Materials and methods:  A cross‐sectional study was undertaken to assess a total of 1167 textile factory workers randomly selected from a total of 6947. An overall 97 women and 1070 men aged 18–69 years (mean=31.8 years) were studied. Regular smoking during the past 6 months was considered as the smoker group. Leukoplakia lesions were classified in accordance to Axell criteria [Axell T, Pindborg JJ, Smith CJ and Van‐der‐waal I (1996). J Oral Pathol Med25: 49].

Results:  The results showed that 115 workers (9.9%) had red and white lesions. Among these 43 positive detections (3.7%) had leukoplakia and six cases (0.5%) had lichen planus. The smoking habits of the workers were limited to cigarette smoking. There was a statistically significant positive correlation between tobacco smoking and oral leukoplakia (P < 0.001).

Conclusion:  There was a statistically significant positive correlation between tobacco smoking and leukoplakia in this relatively young cohort with generally mild tobacco use. The prevalence of leukoplakia had an inverse relationship with the level of education.
Clinical and pathological features of the murine AT‐84 orthotopic model of oral cancer
Authors: Lou E , Kellman RM , Hutchison R , Shillitoe EJ
Published: October 2003

Objective:  The murine AT‐84 orthotopic model of oral cancer was assessed to find how similar it is to human oral cancer. This was done because testing of new treatments for oral cancer requires the use of a realistic animal model.

Materials and methods:  Tumors were induced at orthotopic (oral) or heterotopic (flank) sites and their features were compared. The therapeutic effects of surgery, 5‐fluorouracil and cisplatin were measured on the orthotopic tumors.

Results:  Tumors had the histological appearance of a sarcomatoid carcinoma, invading locally and causing weight loss and death. The oral tumors metastasized to the lungs frequently. Tumors could be treated with some success by surgery or chemotherapy, but generally recurred.

Conclusions:  The similarities to human oral cancer suggest that the model will be very useful in the evaluation of experimental therapies for oral cancer.
Primate Rituals: The Function of Greetings between Male Guinea Baboons
Authors: Whitham Jessica C. , Maestripieri Dario
Published: October 2003

The bond‐testing hypothesis suggests that social animals can obtain honest information about the quality of their dyadic relationships by exchanging costly, high‐risk signals (Zahavi & Zahavi 1997). We evaluated this hypothesis by investigating whether adult male baboons use intense greeting interactions to test the quality and strength of their social bonds. Intense greetings involve intimate and risky behaviors such as embracing and the diddling of the penis and/or scrotum. Data were collected on a colony of 40 Guinea baboons (Papio papio) at the Brookfield Zoo in Chicago. Fifteen adult male baboons were focally observed for 30‐min sessions over a 6‐mo period, resulting in 195 h of observation. We assessed the quality of male–male relationships using measures of affiliation, aggression, and social tolerance. As predicted by the bond‐testing hypothesis, dyads with strong social bonds exchanged a higher frequency of intense greetings than did pairs with poor relationships. We found no support for the competing hypotheses, that suggest that greetings have an aggressive or submissive function or are used as a form of post‐conflict reconciliatory behavior. Neither dominance relationships nor contextual variables were predictive of intense greeting patterns. We suggest that by imposing on his partner, a male baboon is able to obtain reliable information about this individual's current willingness to cooperate and invest in the relationship.
Successful Application of Video‐Projected Human Images for Signalling to Dogs
Authors: Pongrácz Péter , Miklósi Ádám , Dóka Antal , Csányi Vilmos
Published: October 2003

Dogs were tested (1) in a two‐way choice experiment, where the experimenter indicated a baited bowl by pointing; and (2) in a task where the owner was asked to command the dog to execute simple obedience tasks. In expt 1 dogs (n = 10) were tested at first in the presence of the experimenter (three dimensional condition, 3D), that was followed by a series of pointing trials when the life‐sized image of the experimenter was projected onto the wall by the means of a video‐projector (two dimensional condition, 2D). Dogs performed correctly more often than expected by chance in both 3D and 2D conditions. In expt 2 the commanding owner was either present in the room (3D), or her/his image was projected on the screen (2D), or only her/his voice was audible for the dog through a speaker (0D). The performance of the dogs (n = 10) decreased to great extent comparing the 3D and 0D condition, as the number of different actions the dogs obeyed was significantly less in the 0D condition. However, there was no difference in the number of different actions obeyed in the 3D and 2D conditions. Our results show that dogs readily obey life‐sized, interactive moving image in various communicative situtations. We suppose that the difference between 2D and 3D conditions can be attributed partially to the lack of some additional communicative signals as sounds (verbal cues) and odours (from the human), and to some changes in the context.