Soft-tissue sarcomas of the upper extremity: surgical treatment and outcome

The objective of this retrospective follow-up study was to evaluate the outcome of patients with soft-tissue sarcoma treated by the authors' protocol, which consists of a selective combination of conservative surgery and radiotherapy. Patients who relapsed were especially evaluated to improve treatment results. The authors examined 80 patients with local soft-tissue sarcoma in the upper extremity referred to their multidisciplinary group. Fifteen patients were referred for first or subsequent local recurrence, and 65 patients were treated for primary tumor. The goal of treatment was local control and preservation of a functional limb. Wide excision was attempted. If the margin was less than 2.5 cm, postoperative radiotherapy was administered. Eighty-five percent of the patients were treated by limb salvage. Thirty patients needed reconstructive procedures such as pedicled (20 patients) or free flaps (10 patients). No free flaps were lost. The 5-year disease-specific overall survival rate was 75 percent, the local recurrence-free survival rate was 79 percent, and the metastasis-free survival rate was 68 percent. In univariate analysis, prognostic factors for local recurrence were extracompartmental site; for development of metastases, large size and extracompartmental site; and for decreased disease-specific overall survival, large size and extracompartmental site. Intramuscular, cutaneous, and subcutaneous tumors had a 5-year local control rate of 100 percent, and extracompartmental tumors had a local control rate of 69 percent. Extracompartmental tumors clearly have the worst prognosis and should be the main target for improving treatment strategies. After exclusion of patients with inadequate treatment according to the authors' protocol, the local control rate at 5 years was 90 percent. Strict adherence to treatment protocol should be practiced.     

Bile acid amidoalcohols: simple organogelators

Simple bile acid amide synthesis of lithocholic and deoxycholic acids with 2-aminoethanol and 3-aminopropanol are reported. The structural properties of these amides were examined by NMR spectroscopic, ESI-TOF mass spectral, and X-ray crystallographic methods. The gelation properties of these amides in common organic solvents and in three different water solutions were also investigated using Tyndall effect, SEM, TEM, and optical microscopy. 2-Hydroxyethylamides were found to be effective gelators in chlorinated organic solvents and 3-hydroxypropylamides in aromatic solvents. Both derivatives thicken neutral and acidic water solutions.     

Intracellular and cell surface localization of a complex between alphaMbeta2 integrin and promatrix metalloproteinase-9 progelatinase in neutrophils

We have recently demonstrated that promatrix metalloproteinases (proMMPs), particularly proMMP-9, are potent ligands of the leukocyte beta(2) integrins. We studied here the complex formation between proMMP-9 and alpha(M)beta(2), the major MMP and integrin of neutrophils. On resting neutrophils, the proMMP-9/alpha(M)beta(2) complex was primarily detected in intracellular granules, but after cellular activation it became localized to the cell surface, as demonstrated by immunoprecipitation and double immunofluorescence. Further indication of the complex formation was that neutrophils and alpha(M)beta(2)-transfected L cells, but not the wild-type L cells or leukocyte adhesion deficiency cells, bound to immobilized proMMP-9 or its recombinant catalytic domain in a beta(2) integrin-dependent manner. Peptides that bound to the alpha(M) integrin-I domain and inhibited its complex formation with proMMP-9 prevented neutrophil migration in a transendothelial assay in vitro and in a thioglycolate-elicited peritonitis in vivo. These results suggest that the translocating proMMP-9/alpha(M)beta(2) complex may be part of the cell surface machinery guiding neutrophil migration.     

Gelatinase-mediated migration and invasion of cancer cells

The matrix metalloproteinases(MMP)-2 and -9, also known as the gelatinases have been long recognized as major contributors to the proteolytic degradation of extracellular matrix during tumor invasion. In the recent years, a plethora of non-matrix proteins have also been identified as gelatinase substrates thus significantly broadening our understanding of these enzymes as proteolytic executors and regulators in various physiological and pathological states including embryonic growth and development, angiogenesis and tumor progression, inflammation, infective diseases, degenerative diseases of the brain and vascular diseases. Although the effect of broad-spectrum inhibitors of MMPs in the treatment of cancer has been disappointing in clinical trials, novel mechanisms of gelatinase inhibition have been now identified. Inhibition of the association of the gelatinases with cell-surface integrins appears to offer highly specific means to target these enzymes without inhibiting their catalytic activity in multiple cell types including endothelial cells, tumor cells and leukocytes. Here, we review the multiple functions of the gelatinases in cancer, and especially their role in the tumor cell migration and invasion.     

Serologic survey for selected virus infections in polar bears at Svalbard

Polar bears (Ursus maritimus) were chemically immobilized and sampled at Svalbard, Norway, and on the pack ice in the Barents Sea from late March to mid-May between 1990 and 1998. Plasma samples were tested for the presence of antibodies to canine distemper virus (CDV), calicivirus, phocid herpesvirus type 1 (PhHV-1), and rabies virus. A seroprevalence of 8% to CDV and 2% to calicivirus were found, whereas no antibodies were detected against PhHV-1 or rabies virus. This serologic survey indicates that polar bears in this region are exposed to morbillivirus and calicivirus, although the nature of these viruses and infections are unknown. Morbillivirus and calicivirus are potential pathogens in seals, but it is unknown whether they may cause health problems in polar bears.     

Predator-induced synchrony in population oscillations of coexisting small mammal species

Comprehensive analyses of long-term (1977-2003) small-mammal abundance data from western Finland showed that populations of Microtus voles (field voles M. agrestis and sibling voles M. rossiaemeridionalis) voles, bank (Clethrionomys glareolus) and common shrews (Sorex araneus) fluctuated synchronously in 3 year population cycles. Time-series analyses indicated that interspecific synchrony is influenced strongly by density-dependent processes. Synchrony among Microtus and bank voles appeared additionally to be influenced by density-independent processes. To test whether interspecific synchronization through density-dependent processes is caused by predation, we experimentally reduced the densities of the main predators of small mammals in four large agricultural areas, and compared small mammal abundances in these to those in four control areas (2.5-3 km(2)) through a 3 year small-mammal population cycle. Predator reduction increased densities of the main prey species, Microtus voles, in all phases of the population cycle, while bank voles, the most important alternative prey of predators, responded positively only in the low and the increase phase. Manipulation also increased the autumn densities of water voles (Arvicola terrestris) in the increase phase of the cycle. No treatment effects were detected for common shrews or mice. Our results are in accordance with the alternative prey hypothesis, by which predators successively reduce the densities of both main and alternative prey species after the peak phase of small-mammal population cycles, thus inducing a synchronous low phase.     

Birds of prey as limiting factors of gamebird populations in Europe: a review

Whether predators can limit their prey has been a topic of scientific debate for decades. Traditionally it was believed that predators take only wounded, sick, old or otherwise low-quality individuals, and thus have little impact on prey populations. However, there is increasing evidence that, at least under certain circumstances, vertebrate predators may indeed limit prey numbers. This potential role of predators as limiting factors of prey populations has created conflicts between predators and human hunters, because the hunters may see predators as competitors for the same resources. A particularly acute conflict has emerged over the past few decades between gamebird hunters and birds of prey in Europe. As a part of a European-wide research project, we reviewed literature on the relationships between birds of prey and gamebirds. We start by analysing available data on the diets of 52 European raptor and owl species. There are some 32 species, mostly specialist predators feeding on small mammals, small passerine birds or insects, which never or very rarely include game animals (e.g. hares, rabbits, gamebirds) in their diet. A second group (20 species) consists of medium-sized and large raptors which prey on game, but for which the proportion in the diet varies temporally and spatially. Only three raptor species can have rather large proportions of gamebirds in their diet, and another seven species may utilise gamebirds locally to a great extent. We point out that the percentage of a given prey species in the diet of an avian predator does not necessarily reflect the impact of that predator on densities of prey populations. Next, we summarise available data on the numerical responses of avian predators to changing gamebird numbers. In half of these studies, no numerical response was found, while in the remainder a response was detected such that either raptor density or breeding success increased with density of gamebirds. Data on the functional responses of raptors were scarce. Most studies of the interaction between raptors and gamebird populations give some estimate of the predation rate (per cent of prey population taken by predator), but less often do they evaluate the subsequent reduction in the pre-harvest population or the potential limiting effect on breeding numbers. The few existing studies indicate that, under certain conditions, raptor predation may limit gamebird populations and reduce gamebird harvests. However, the number and extent of such studies are too modest to draw firm conclusions. Furthermore, their geographical bias to northern Europe, where predator-prey communities are typically simpler than in the south, precludes extrapolation to more diverse southern European ecosystems. There is an urgent need to develop further studies, particularly in southern Europe, to determine the functional and numerical responses of raptors to gamebird populations in species and environments other than those already evaluated in existing studies. Furthermore, additional field experiments are needed in which raptor and possibly also mammalian predator numbers are manipulated on a sufficiently large spatial and temporal scale. Other aspects that have been little studied are the role of predation by the non-breeding part of the raptor population, or floaters, on the breeding success and survival of gamebirds, as well as the effect of intra-guild predation. Finally there is a need for further research on practical methods to reduce raptor predation on gamebirds and thus reduce conflict between raptor conservation and gamebird management.     

Incorporation of mammalian actin into microfilaments in plant cell nucleus

Background  

Actin is an ancient molecule that shows more than 90% amino acid homology between mammalian and plant actins. The regions of the actin molecule that are involved in F-actin assembly are largely conserved, and it is likely that mammalian actin is able to incorporate into microfilaments in plant cells but there is no experimental evidence until now.