bluuebunny/crossref_metadata_2025 huggingface dataset:
What causes outbreaks of the gypsy moth in North America?
Authors: Liebhold A. , Elkinton J. , Williams D. , Muzika R.‐M.
Published: April 2006

The gypsy moth has been present in North America for more than 100 years, and in many of the areas where it has become established outbreaks occur with varying degrees of periodicity. There also exists extensive spatial synchrony in the onset of outbreaks over large geographic regions. Density‐dependent mortality clearly limits high‐density populations, but there is little evidence for strong regulation of low‐density populations. Predation by small mammals appears to be the major source of mortality affecting low‐density populations, but because these are generalist predators and gypsy moths are a less preferred food item, mammals do not appear to regulate populations in a density‐dependent fashion. Instead, predation levels appear to be primarily determined by small mammal abundance, which is in turn closely linked to the production of acorns that are a major source of food for overwintering predator populations. Mast production by host oak trees is typically variable among years, but considerable spatial synchrony in masting exists over large geographic areas. Thus, it appears that the temporal and spatial patterns of mast production may be responsible for the episodic and spatially synchronous behavior of gypsy moth outbreaks in North America. This multitrophic relationship among mast, predators, and gypsy moths represents a very different explanation of forest insect outbreak dynamics than the more widely applied theories based upon predator–prey cycles or feedbacks with host foliage quality.
Population dynamics of the beech caterpillar, Syntypistis punctatella, and biotic and abiotic factors
Authors: Kamata N.
Published: April 2006

The beech caterpillar, Syntypistis punctatella (Motschulsky) (Lepidoptera: Notodontidae), often causes extensive defoliation of beech forests in Japan. Outbreaks have often occurred synchronously among different areas at intervals of 8–11 years. Synchrony of outbreaks was considered to be caused by synchrony of weather. Populations of this insect exhibit periodical dynamics in both outbreak and nonoutbreak areas. Factors that might influence the population dynamics of the beech caterpillar were classified from the point of view of the natural bioregulation com‐plex, which includes a coleopteran predator, Calosoma maximowiczi, avian predators, parasitoids, entomopathogenic fungi, and delayed induced defensive response (DIR) of beech trees. Because such periodic population dynamics are believed to be caused by one or more delayed density‐dependent factors, delayed density‐dependent mortality has been identified as a likely source of population cycles. The DIR and pathogenic diseases showed a high order of density dependence. An infectious pathogen, Cordyceps militaris, was considered to be the most plausible agent responsible for periodic dynamics of the beech caterpillar population because insect diseases were effective in cases in which the S. punctatella population started to decrease without reaching outbreak densities, but DIR was not. Conspicuous defoliation caused by this insect tends to occur at certain elevations, where forests are composed of pure stands of beech trees. I propose three different hypotheses to explain this phenomenon: the diversity–stability hypothesis, the resource concentration hypothesis, and the altitudinal soil nutrient hypothesis.
Interspecific body size differentiation in species assemblages of the carabid subgenus Ohomopterus in Japan
Authors: Sota T. , Takami Y. , Kubota K. , Ujiie M. , Ishikawa R.
Published: April 2006

Geographic variation and interspecific differentiation in body size (body length) were analyzed for 15 species of the carabid subgenus Ohomopterus (genus Carabus; Coleoptera, Carabidae) in Japan. Local species assemblages of this subgenus consist of up to 5 species of different size classes. These beetles exhibited sexual dimorphism in body size where females are larger than males, except Carabus uenoi, in which the male and female sizes were equivalent, possibly because of the exaggerated male genitalia. In 9 of 15 species, there was a positive correlation between mean body size and annual mean temperature of habitat, representing the converse of Bergmann's rule. However, in some cases this correlation does not hold over the range of a species because of regional differences. When allopatric and sympatric populations were compared, allopatric populations of Carabus albrechti and C. japonicus had larger bodies than sympatric populations. These intraspecific differences may have resulted from character displacement. In each local assemblage with 2 or more species, there was little interspecific overlap of body size, although the body size ratio between two species with adjacent body sizes seldom showed strict constancy. The mean size ratio between 2 adjacent species in an assemblage was reduced with the number of species, whereas the size ratio of the largest to smallest species in an assemblage increased with the number of species (i.e., the expansion of body size range). These results indicate that the body size of Ohomopterus species may have evolved in response to both climatic conditions and interspecific interactions. Because each species or species group represents the same size class over the distribution range and similar‐sized species are parapatric or allopatric, the interspecific segregation in body size in local assemblages may have resulted mainly from a size assortment process during colonization.
A stochastic model for the spatial distribution of species based on an aggregation–repulsion rule
Authors: Mouillot D. , Lepretre A. , Andrei‐Ruiz M.‐C. , Mouillot F. , Viale D.
Published: April 2006

The heterogeneity associated with the spatial distribution of organisms is an awkward problem in ecology because this heterogeneity directly depends on the sampling scale. To specify the scope of the influence of sampling scale on the level of species aggregation, we need data sets that entail excessive sampling costs in situ. To find a solution for this problem, we can use models to simulate patterns of organisms. These models are often very complex models that take into account heterogeneity of habitats and displacement or longevity of studied species. In this article, we introduce a new stochastic model to simulate patterns for one taxon and we want this model to be parsimonious, i.e., with few parameters and able to simulate observed patterns. This model is based on an aggregation–repulsion rule. This aggregation–repulsion rule is defined by two parameters. On a large scale, the number of aggregates present on the pattern is the first parameter. On a smaller scale, the level of aggregation–repulsion among individuals is determined by a probability distribution. These two parameters are estimated from field data set in a robust way so that the simulated patterns reflect the observed heterogeneity. We apply this model to entomological data: four Diptera families, namely the Sciaridae, Phoridae, Cecidomyiidae, and Empididae. The field data for the Phoridae family are used to simulate sampling using different trap sizes. We record changes in the coefficient of variation (C) as a function of the sampling scale, and we can suggest to ecologists emergence traps of 0.6 m2, in other words a square 77 × 77 cm trap, to obtain a C value under 20%.
Introduction: Plant–herbivore interactions
Authors: Ohsaki N.
Published: April 2006

This special feature resulted from a symposium entitled “Interactions Between Plants and Their Herbivores,” held during the Meeting of the Society of Population Ecology in Ohmi‐Shirahama, Shiga, Japan, in October 1999 (Chairperson of Symposium: Professor Emeritus E. Kuno of Kyoto University). This theme emerged from discussions by the organizing committee for this symposium: N. Yamamura, J. Takabayashi, T. Nishida, and N. Ohsaki. Professor Mark D. Rausher of Duke University was invited as a special lecturer. In this series of reports, five of the seven participants illustrate the variation found in plant–herbivore interactions and address some problems inherent in current theory.
Migration of specialist insect predators to exploit patchily distributed spider mites
Authors: Shimoda T. , Takabayashi J.
Published: April 2006

It is believed that specialist predators of spider mites often migrate by flight or aerial transport to exploit patchily distributed prey. The migration is an important factor in determining the seasonal occurrence of the predators in a field. Several species of specialist insect predators, such as Oligota kashmirica benefica (Coleoptera: Staphylinidae) and Scolothrips takahashii (Thysanoptera: Thripidae), migrate between orchard trees and plants near the trees (e.g., groundcover, weeds, or windbreaks) to exploit abundant spider mites. This migration is at least partly triggered by prey scarcity in the original local habitats. Although these predators are tiny insects, they have flight abilities. For example, adult O. kashmirica benefica (body length, ∼1 mm) could move at least 5–16 m in one flight. Presumably, migration of the insect predators between prey‐infested plants occurs mainly by flights. Predatory mites, such as Amblyseius fallacis and Amblyseius womersleyi (Acari: Phytoseiidae), migrated to spider mite‐infested plants outside an orchard by aerial transport when they suffered from prey scarcity in the orchard. S. takahashii can use plant volatiles from lima bean plants induced by the spider mite Tetranychus urticae as cues for prey location during migration in Satsuma mandarin groves. However, it remains unknown how far from the trap boxes S. takahashii could respond to herbivore‐induced plant volatiles in the groves.
Infochemically mediated tritrophic interaction webs on cabbage plants
Authors: Shiojiri K. , Takabayashi J. , Yano S. , Takafuji A.
Published: April 2006

In response to damage by herbivores, plants are known to emit infochemicals that enhance the effectiveness of insect parasitoids. Studies on plant–parasitoid interactions mediated by such infochemicals have focused on the tritrophic systems in which plants are infested by a single herbivore species. In natural ecosystems, however, plants are often simultaneously infested by several herbivorous species. The present study focuses on two herbivorous species that simultaneously attack crucifer plants and their respective parasitic wasps. We first show the specific responses of the two specialist parasitic wasps [Cotesia plutellae and C. glomerata (Hymenoptera: Braconidae)] to infochemicals originating from cabbage plants (Brassica oleracea cv. Sikidori) infested by each of their respective host larvae [Plutella xylostella (Lepidoptera: Yponomeutidae) and Pieris rapae (Lepidoptera: Pieridae)]. We then coupled the two tritrophic systems on the same cabbage plants. These experiments demonstrated the presence of indirect interactions between the two species of herbivores. Overall, the results indicate the presence of infochemically mediated tritrophic interaction webs on a single plant.
Indirect interactions mediated by leaf shelters in animal–plant communities
Authors: Fukui A.
Published: April 2006

Leaf shelters indirectly mediate interactions in animal–plant communities by providing the occupants with several kinds of benefits, as physical ecosystem engineering. The occupants benefit from favorable microhabitat, reduction in antiherbivore defense, and protection from natural enemies. The primary shelter maker has to spend energy and time and producing silk, but shelter users have great advantages without incurring costs. Shelter users consist of a wide range of arthropod taxa and can be divided into two groups: coexisting organisms that live with a primary shelter maker in the same shelter, and secondary users, which inhabit a leaf shelter after it is utilized by a shelter maker. Leaf shelters mediate interactions between (1) primary shelter makers and coexisting organisms or (2) primary shelter makers and secondary users, (3) secondary users, (4) shelter users and their natural enemies, and (5) primary shelter makers, secondary users, and their host plants. Most interactions between primary shelter makers and coexisting organisms constitute a direct trophic linkage rather than indirect ones. There are actually unidirectional beneficial effects from a primary shelter maker to secondary shelter users, whereas leaf shelters mediate competition and predation among shelter users. By providing a leaf shelter, a shelter maker leads to increased diversity of interactions. Leaf shelters modify the distribution of organisms on the host plant and influence herbivory on the host plant. In tritrophic interactions, leaf shelters act as cues for natural enemies that search for a shelter user as prey. Furthermore, by enhancing habitat heterogeneity, leaf shelters affect the abundance and species richness of arthropods on host plants.
A review of the ecological parameters and implications of subsociality in Parastrachia japonensis (Hemiptera: Cydnidae), a semelparous species that specializes on a poor resource
Authors: Filippi L. , Hironaka M. , Nomakuchi S.
Published: April 2006

Subsocial behavior or postovipositional parental care in insects has evolved in response to a variety of environmental stresses and ranges from briefly guarding eggs after oviposition to elaborate nidification and provisioning behaviors. Investment in parental care bears various costs, and should not continue beyond the point at which the costs to future reproductive success exceed the benefits to current reproductive effort. Progressive provisioning is a rare form of subsociality in insects. Females of the subsocial shield bug Parastrachia japonensis progressively provision their nymph‐containing nests with drupes of the single resource, Schoepfia jasminodora, and this provisioning drastically enhances offspring survival. A female rears only one brood throughout her lifetime and continues provisioning the brood until about the third larval stadium, when the female dies. Thus, the female's entire reproductive effort is expressed in the success of that one brood, which suggests a reproductive strategy with enormous costs and risks. Why has such an extreme life history evolved in this species? Here, to answer that question and to contribute to our understanding of the evolutionary implications of subsocial behavior, in particular, progressive provisioning, we review what we have discovered about the ecological parameters of subsociality in this species during a long‐term field study. We also discuss these parameters in P. japonensis in reference to other subsocial insects and related species and conclude with a suggestion that semelparity and progressive provisioning in this species are extreme adaptations to evolving complete dependency on an unreliable resource.
Introduction
Authors: Nishida T.
Published: April 2006

This article introduces the special issue on flower–pollinator interactions in the tropics deriving from the 19th symposium of the Society of Population Ecology, held at Ohmi‐shirahama, Shiga, Japan, in October 1999.
Do competing honey bees matter? Dynamics and abundance of native bees before and after honey bee invasion
Authors: Roubik D. W. , Wolda H.
Published: April 2006

To provide replicate samples of local bee populations in a nature preserve, light traps operated continuously on Barro Colorado Island (BCI), Panama, collected bees for 17 years, including 10 years following invasion by African Apis mellifera. Honey bees appeared in light traps as the first swarms colonized the Panama Canal area. Their numbers followed seasonal trends shown in inde‐pendent studies, thus indicating bee abundance and activity in a large area. No measurable population‐level impact of competition between this invading honey bee and native bees, despite many demonstrations of resource competition at flower patch and colony levels, changed annual abundances of all 15 native bee species. Native bee abundance did not decrease, nor did native bees show substantial reciprocal yearly change with honey bee abundance. One strong negative correlation of bee catches with an extremely rainy year was found. However, multiple regression using rainfall and honey bee abundance as the independent variables showed that neither was responsible for bee population change over 17 years. Nearly half the native species declined during a year that displayed peak honey bee number. That competition from honey bees on an island the size of BCI was necessarily reduced below impact levels expected on the mainland is discussed using a model of resource and consumer density, foraging range, and island size.
Drought and the consequences of El Niño in Borneo: a case study of figs
Authors: Harrison R. D.
Published: April 2006

Borneo has a perhumid climate but occasional severe droughts have an important impact. Droughts may affect the composition and size structure of plant communities through differential mortality or, via their impact on the availability of plant resources, affect plant–animal interactions. From January to April 1998, northern Borneo suffered a very severe drought linked to the El Niño Southern Oscillation event of 1997–1998. In this article, the impacts of this drought on the rain forest at Lambir Hills National Park, Sarawak, are considered with special reference to a keystone plant group, the figs. Small fires entered the edge of the forest from the roadside, killing saplings, climbers, and understory trees. Community‐wide mortality for adult trees was 0–7 times higher than in nondrought years, with larger trees showing a greater proportional increase. In figs, mortality was significantly higher in pioneers, but hemiepiphytes and roadside species were unaffected. Phenology was substantially affected. Leaf and flower/fruit production decreased or ceased during the drought and increased suddenly following renewed rain. Pollinators of dioecious figs became locally extinct during the drought, and other plant–animal interactions may also have been disrupted. The frequency and severity of droughts has increased substantially in the past three decades, and climate models suggest this may be the result of global warming. The impacts of the 1998 drought at Lambir Hills National Park suggest that, should this trend continue, a substantial alteration of habitats and overall loss of biodiversity can be expected in Borneo.
Competition for a limited space in kleptoparasitic Argyrodes spiders revealed by field experiments
Authors: Miyashita T.
Published: April 2006

Most kleptoparasitic Argyrodes spiders rely exclusively on host spider webs for obtaining their food. Because their densities occasionally reach high levels within a restricted area, competitive interactions may be important for determining the density of these unique spiders. Here I used two Argyrodes species commonly found on webs of the large orb‐web spider Nephila clavata to clarify whether inter‐ and intraspecific competition influences abundance and within‐web distribution by using observational data and field experiment. Removing Argyrodes flavescens from the host webs induced a remarkably high immigration of that species while density on control webs remained almost at the same level, which is evidence for strong intraspecific competition. Larger individuals of A. flavescens were located more frequently at the capture area of the host webs where it is easy to access prey ignored by the host spider, and spiders immigrating into webs from which that species had been removed were smaller in body size, suggesting interference competition for space among conspecific kleptoparasites. Argyrodes bonadea increased in number on webs from which A. flavescens had been removed, and the increase was correlated with the number of A. flavescens removed. This finding is evidence for interspecific competition that is rarely reported in spiders. A multiple regression model including numbers of a conspecific parasite as well as web and body sizes of the host spider could not detect competitive interactions between species, suggesting the importance of experimental approaches.
Recovery plan for an exploited species, southern bluefin tuna
Authors: Mori M. , Katsukawa T. , Matsuda H.
Published: April 2006

Southern bluefin tuna (SBT) were heavily depleted in the mid‐1980s, and the fishing quota has been restricted since 1985. As a result of this restriction and protection of immature individuals, spawning stock biomass (SSB) recently has shown a slight increase. The Commission for the Conservation of Southern Bluefin Tuna (CCSBT) has the target of recovering SSB to the 1980 level by 2020. We investigated whether SBT populations will recover and reach the target level set by CCSBT. Our projection shows that the SSB of the SBT will temporarily decrease again after 1999. This temporary decrease of SSB does not always mean failure of the recovery plan, because the SSB trend is highly vulnerable to age‐composition dynamics. The SBT is an example of this. The number of mature SBT was small during the 1980s because of overfishing. Thus, the number of eggs that were spawned by these mature SBT was small in these years, and when these small numbers of immature fish become mature, the SSB will decrease again. We call this effect the inverse baby‐boom effect. The inverse baby‐boom effect may be common for managed bioresources that have once been overexploited. We also examine the use of spawning potential (SP) and SSB as an index of stock recovery.
Blood Supply and Parathyroid Hormone Secretion in Pathological Parathyroid Glands
Authors: Ander Stefan , Johansson Kenth , Smeds Stafan
Published: April 2006

The blood supply of pathologic parathyroid glands and the relation between parathyroid hormone secretion and parathyroid blood perfusion was studied during surgery for hyperparathyroidism. Blood flow in 39 single adenomas and 20 glands classified as primary or secondary hyperplasia were studied intraoperatively with laser Doppler flowmetry. The ipsilateral inferior thyroid artery was occluded during continuous flowmetry recording, which resulted in a 40% reduction of parathyroid blood flow in both groups. In 12 patients with single adenomas, intact parathormone (iPTH) was measured intraoperatively before and during occlusion of the ipsilateral inferior thyroid artery and after extirpation of the adenoma. During occlusion the iPTH levels were mainly unchanged despite blood flow reduction of up to 80%. After removal of the adenoma the iPTH normalized within 15 minutes. In a control group of eight single adenomas, iPTH was measured similarly without vascular occlusion, demonstrating comparable iPTH levels. This study demonstrates similar routes of vascularization for single adenomas and hyperplastic glands, as was earlier seen for normal parathyroid glands. The increased parathyroid hormone secretion from single adenomas appears to remain mainly unchanged during significant blood flow reduction.
Clinicopathologic Study for the Assessment of Resection for Ampullary Carcinoma
Authors: Böttger Thomas C. , Boddin Jörg , Heintz Achim , Junginger T.
Published: April 2006

In a prospective observational study including 34 patients with carcinoma of the ampulla of Vater, postoperative morbidity, mortality, and long‐term survival were analyzed to determine the surgical procedure of choice. Surgically related postoperative complications were observed in 35.4% of patients after pancreatic resection. No patient died within the first 30 days postoperatively, and in‐hospital mortality was 3%. Lymph node metastases were associated only with moderate or undifferentiated tumors larger than 0.6 cm in diameter that infiltrated beyond the ampulla of Vater. The median follow‐up time was 4.3 years. The 5‐year survival rate for the 31 patients undergoing radical resection was 62.7%. Multivariate analysis (including the covariates depth of tumor infiltration, lymph node metastases, and the ratio of metastatic to dissected lymph nodes) demonstrated that only this ratio exerted an independent influence on the prognosis (p= 0.001). The present series demonstrates that radical resection of ampullary cancer is the procedure of choice even in elderly patients. The most important factor influencing the survival rate is the extent of the lymph node dissection. The histopathologic investigation of our pancreatoduodenectomy specimens demonstrates clearly that local excision of ampullary cancer may be indicated only in high risk patients with a pT1, well differentiated tumor smaller than 0.6 cm in diameter.
High Preoperative Serum Alanine Transferase Levels: Effect on the Risk of Liver Resection in Child Grade A Cirrhotic Patients
Authors: Noun Roger , Jagot Pascal , Farges Olivier , Sauvanet Alain , Belghiti Jacques
Published: April 2006

Despite careful selection of cirrhotic patients with hepatocellular carcinoma (HCC), liver resection remains associated with a greater risk than in patients without underlying liver disease. In this study we assessed by multivariate analysis parameters associated with in‐hospital mortality and morbidity in a selected group of 108 Childs‐Pugh A cirrhotic patients undergoing liver resection of HCC. The overall incidences of in‐hospital deaths and postoperative complications were 8.3% and 48.1%, respectively. By univariate analysis, the preoperative serum alanine transferase (ALT) level (p= 0.001) and intraoperative transfusions (p= 0.01) were significantly associated with in‐hospital death; however, only the serum ALT concentration was an independent risk factor. In‐hospital mortality rates in patients whose serum ALT was below 2N (twofold the upper limit of the normal value), between 2N and 4N, and more than 4N were 3.9%, 13.0%, and 37.5%, respectively. An ALT level greater than 2N was predominantly observed in patients with a hepatitis C virus infection and significantly associated with histologic features of superimposed active hepatitis. Patients with an ALT level greater than 2N experienced an increased incidence of postoperative ascites (58% versus 32%,p= 0.01), kidney failure (16% versus 0%,p= 0.0003), and upper gastrointestinal bleeding
(6.4% versus 0%, p= 0.02). These results indicate that the preoperative ALT level is a reliable predictor of in‐hospital mortality and morbidity following liver resection in Child‐Pugh A cirrhotic patients. Cirrhotic patients with ALT > 2N should undergo only a limited resection; if a larger resection is required, those patients should be considered for nonsurgical therapy or liver transplantation.
Changes in Body Composition after Gastrectomy: Results of a Controlled, Prospective Clinical Trial
Authors: Liedman B. , Andersson H. , Bosaeus I. , Hugosson I. , Lundell L.
Published: April 2006

To elucidate mechanisms involved in weight development after gastrectomy we have prospectively determined changes in body composition during the first year after similar operations. A total of 75 patients were enrolled who had a “curative operation” for gastric carcinoma; 42 were randomized to have a total gastrectomy, 23 total gastrectomy with a gastric substitute, and 10 subtotal gastrectomy. All reconstructions were done with a Roux‐en‐Y loop of the jejunum. Body composition was assessed preoperatively and at 6 and 12 months after gastrectomy by determining total body potassium and total body water. From these estimates, body cell mass, extracellular water, fat‐free extracellular solids, and body fat were calculated with knowledge of the actual body weight and length. Triceps skinfold, arm muscle circumference, and grip strength were also measured. Weight loss (10% of preoperative weight) occurred early after the operations, after which body weight stabilized. Body cell mass remained essentially unchanged over the entire study period in contrast to body fat, which decreased by 40% during the first 6 months after gastrectomy. In accordance with the selective loss of body fat, we recorded a significant decrease in triceps skinfold figures and only a minor decrease of arm muscle circumference without obvious deterioration in hand grip strength. Weight loss after gastrectomy seems to be characterized by selective loss of body fat in contrast to other known clinical situations associated with impaired nutritional intake. Our observations form a basis for future clinical research aimed at preventing weight loss after these operations.
Quality of Life after Gastrectomy for Gastric Carcinoma: Controlled Study of Reconstructive Procedures
Authors: Svedlund Jan , Sullivan Marianne , Liedman Bengt , Lundell Lars , Sjödin Ingemar
Published: April 2006

The choice of reconstruction after gastrectomy and the significance of remaining reservoir function is a matter of controversy. To broaden the criteria for choice of treatment, we conducted a prospective randomized clinical trial to determine the impact of various gastrectomy procedures on quality of life. Consecutive patients (n= 64) eligible for curative gastric cancer surgery were randomized to have either a total (n= 31) or subtotal (n= 13)
gastrectomy or a jejunal S‐shaped pouch (n= 20) implanted as a gastric substitute. The quality‐of‐life evaluation was based on a battery of questionnaires covering both general and specific aspects of life. The patients were rated by one of two psychiatrists who were blinded to the patients’ group affiliation. Assessments were made on three occasions: during the week prior to surgery and 3 and 12 months after the surgical intervention. The postoperative complication and mortality rates were similar in all treatment groups, with few serious complications recorded. Irrespective of type of treatment, the patients suffered from alimentary symptoms and functional limitations in everyday life, whereas their mental well‐being improved after surgery. Patients who underwent subtotal gastrectomy had the best outcome, especially with respect to complaints of diarrhea. Patients given a gastric substitute after gastrectomy showed no difference from those who had only a total gastrectomy. We conclude that despite significant unfavorable consequences that follow gastrectomy, patients recover with an improved mental status. A pouch reconstruction after total gastrectomy does not improve quality of life, but a subtotal gastrectomy has advantages that must be considered when the procedure is clinically feasible.
Causes of Death and Recurrence after Surgery for Early Gastric Cancer
Authors: Guadagni Stefano , Catarci Marco , Kinoshitá Taira , Valenti Marco , De Bernardinis Giancarlo , Carboni Manlio
Published: April 2006

The postoperative course of 172 patients with early gastric cancer (EGC) was followed for a median 7 years to evaluate the causes of death, incidence and patterns of recurrence, and characteristic findings in the recurrent cases. The cumulative 10‐year mortality rate (± SE) was 22 ± 3.7%. Seven patients (4.1%) died of operative mortality, 11 (6.4%) died of a recurrence of the gastric cancer, and 13 (7.6%) died of unrelated causes. Unrelated causes of death were metachronous primary cancer (n = 6), cardiovascular disease (n= 2), pneumonia (n= 3), sepsis (n= 1), and car accident (n= 1). Four patients died from gastric stump recurrence, three from liver metastases, two from lymph node metastases, and two from peritoneal dissemination. Using Cox multivariate analysis, histologic type had the most significant effect on recurrence. Although influenced by the tumor nature, the EGC prognosis is relatively good. Based on the results of this study, particularly in Western institutions, histologic examination of resection margins and lymphadenectomy should be improved. Moreover, patients must be carefully followed for late recurrence and metachronous cancer.
Surgical Management of Gastric Leiomyosarcoma: Evaluation of the Propriety of Laparoscopic Wedge Resection
Authors: Yoshida Masashi , Otani Yoshihide , Ohgami Masahiro , Kubota Tetsuro , Kumai Koichiro , Mukai Makio , Kitajima Masaki
Published: April 2006

Laparoscopic surgery has been applied to malignant gastric tumors. To evaluate the propriety of laparoscopic wedge resection for gastric leiomyosarcoma it is necessary to question whether lymph node dissection is necessary for the surgical management of gastric leiomyosarcoma. A retrospective study on open surgery cases of gastric leiomyosarcoma was performed to address this issue. The clinical records of 28 patients with gastric leiomyosarcoma who had had surgery were examined. The patients who underwent open surgery were divided into a systematic lymph node dissection (SLND) group (n= 9) and a nondissection (non‐D) group (n= 19). No patient had lymph node metastasis at the time of operation or recurrence, and statistical analysis showed no difference between the SLND and non‐D groups in terms of survival rates. These data suggest that SLND might not be necessary for the surgical management of gastric leiomyosarcoma and that laparoscopic wedge resection of the stomach can be considered a first‐line treatment for gastric leiomyosarcoma.
Surgery for Pulmonary Tuberculosis
Authors: Perelman Mikhail I. , Strelzov Victor P.
Published: April 2006

During the period 1990–1994 a total of 578 operations were performed in 502 patients with various forms of tuberculosis. Most of the patients (68%) were men aged 20 to 50 years (70%). Sputum cultures were positive in 55% of the patients. More than half of all patients were chronic smokers, and about 10% were alcoholics or drug addicts. There were no human immunodeficiency virus‐infected patients, and none with acquired immunodeficiency syndrome. The most frequent surgical interventions were, according to the classification adopted in Russia, for cavernous or fibrocavernous tuberculosis (196 cases) and tuberculomas (161 cases). The main operative procedures used were pulmonary resection (n= 280) and pneumonectomy or pleuropneumonectomy (n= 80). Diseased intrathoracic lymph nodes were ablated in 62 patients. Thoracoplasty or thoracomyoplasty were performed in 46 cases, thoracostomy in 37, closure of a thoracic wall defect in 27, and reamputation of the main bronchial stump in 6. Postoperative complications arose in 20% of the patients. More than half occurred in the pleural cavity or bronchi and were associated with tuberculous infection. The postoperative hospital case‐fatality rate was 2%. The overall clinical efficacy by the time of discharge was 82.7% (95% in tuberculomas). Reactivation of tuberculosis over the first 3 years after discharge occurred in 6.6% of the patients. Most patients with large or multiple caverns, tuberculomas, intrathoracic caseous lymphadenitis, or various complications of pulmonary tuberculosis cannot be cured (or are not amenable to cure in principle) by means of antibacterial therapy because of irreversible morphologic changes in the lungs, bronchi, pleura, lymph nodes, or thoracic wall. For this reason, indications for surgical management of pulmonary tuberculosis should be generally expanded. Excessively long antibacterial therapy for tuberculosis is often inadvisable. Although the availability of standardized regimens of antibacterial therapy is strategically essential, each patient must be treated according to an individual plan. In certain cases thoracic surgeons should be enlisted to participate in the development of such plans.
Role of Thoracic Surgery for Childhood Tuberculosis
Authors: Hewitson John P. , Von Oppell Ulrich O.
Published: April 2006

Lymphadenopathy is the hallmark of intrathoracic tuberculosis in children. The role of the thoracic
surgeon in treating childhood tuberculosis is to relieve the more
severe symptoms of lymphadenopathy, prevent the more long‐term
secondary damage that lymphadenopathy may cause to the lung, and treat
the sequelae of thoracic tuberculosis. We reviewed the role of surgery
in childhood tuberculosis at Red Cross Children's Hospital from
January 1981 to January 1996 in 161 children under 13 who were admitted
for 168 therapeutic surgical interventions for proved intrathoracic
tuberculosis and its related complications. We classified patients
according to the pathophysiology of their disease to clarify the role
of surgery in their management. Successful decompression of lymph nodes
that were acutely compromising major airways was done in 25 children, and decompression for chronic airway compression was successful in 8 of
11 children. Therapeutic bronchoscopy successfully opened an airway
obstructed by intraluminal tissue in 68% of 28 patients, with
long‐term pulmonary reexpansion in 50%. Pulmonary resections for
postprimary tuberculous damage were done in 72 patients with a
mortality of 2.7% and morbidity of 16.7%. Another 17 patients were
operated on for pleural disease and 15 for other tuberculosis‐related
problems. The mortality for all patients undergoing surgery for
complications of tuberculosis during childhood was 1.9% (3/161), suggesting that when indicated, an aggressive surgical approach is
relatively safe.
Surgical Indications for Treatment of Pulmonary Tuberculosis
Authors: Freixinet Jorge
Published: April 2006

Surgery for pulmonary tuberculosis (PTB) has passed through various stages throughout history, having been the treatment of
choice in the past. It has now been relegated to second place for
treatment of this disease. One of the most strongly debated surgical
indications has been clinical picture of multidrug resistance with the
focus of pulmonary tuberculous activity located in a segment, lobe, or
lung. In these cases some authors have described good results with
surgical excision. Another important indication is the complications of
PTB, among which bronchiectases (provoking pictures of suppuration, superinfections, or hemoptysis) are found, along with known destructive
pulmonary sequelae such as destroyed lung, massive hemoptysis, and the
presence of a bronchopleural fistula that cannot be resolved with
pleural drainage. The presence of a neoplasm in a patient affected by
PTB is a surgical indication if the lesion is resectable. The existence
of an unidentifiable pulmonary mass or node is a surgical criterion
because it might signal bronchogenic carcinoma. A frequent indication
for surgery is pulmonary aspergilloma, which in a large percentage of
cases is a destructive PTB sequela and generates serious complications, hemoptysis being the most frequent. Mediastinal tuberculous
lymphadenitis that produces compressive symptoms and pulmonary
complications, especially in children, is another surgical indication
for decompressing the bronchial tree. The surgery in these cases
consists in excision and curettage of adenopathies. Surgery therefore
now constitutes a valid option for the treatment of certain clinical
pictures of PTB that do not respond to medical treatment, are serious, and are potentially fatal.
Intraabdominal Nonvascular Operations Combined with Abdominal Aortic Aneurysm Repair
Authors: Tsuji Yoshihiko , Watanabe Yoshihisa , Ataka Keiji , Sasada Akinori , Okada Masayoshi
Published: April 2006

The therapeutic approach to a patient who has an abdominal aortic aneurysm (AAA) and an intraabdominal nonvascular surgical disorder simultaneously remains controversial. To establish guidelines for the management of those patients, a retrospective review of patients who had concomitant AAA and intraabdominal nonvascular surgical disorders was undertaken. During the period January 1988 to December 1997 a series of 162 patients underwent surgical repairs of AAA in our hospital. Among them 16 patients (9.9%) had several kinds of intraabdominal nonvascular surgical disorders, and 13 underwent one‐stage operation for both diseases. That is, cholelithiasis coexisted in five patients, inguinal hernia in four, gastric cancer in two, and retroperitoneal tumor and renal tumor in one each. All AAAs were the infrarenal type, and there were no inflammatory or ruptured aneurysms. In cases of cholelithiasis coexistent with AAA, aneurysmectomy was performed first. After tight closure of the retroperitoneum, cholecystectomy was done. In cases of cholelithiasis coexistent with AAA, aneurysmectomy was performed first. After tight closure of the retroperitoneum, cholecystectomy was done. In cases of inguinal hernia coexistent with AAA, the AAA was first replaced with a prosthetic vascular graft and a residual piece of the graft was used as a patch for hernioplasty. This procedure was similar to laparoscopic hernioplasty. In two cases of gastric cancer concomitant with AAA, the AAA was first replaced. Subtotal gastrectomy with D2 lymphatic dissection was done after tight closure of the retroperitoneum. A drain was inserted into the epiploic foramen to detect anastomotic leakage. A retroperitoneal tumor coexisting with AAA was dissected and resected en bloc with the aneurysmal wall because the tumor firmly adhered to the aneurysm. The abdominal aorta was then replaced with a prosthetic graft. In a case of renal tumor concomitant with AAA, nephrectomy was done first to perform a complete lymphatic dissection around the renal artery. Then AAA repair was performed with a conventional procedure. There were no fatal complications, such as pneumonitis, hemorrhage, anastomotic leakage, or graft infection. All 13 patients were discharged from our hospital and are currently free from recurrence of malignancy or hernia. In summary, properly selected one‐stage operations for intraabdominal nonvascular surgical disorders and AAA may be safe and bring physical and economic benefit to the patient.
Sigmoidofiberscopic Incision plus Balloon Dilatation for Anastomotic Cicatricial Stricture after Anterior Resection of the Rectum
Authors: Hagiwara Akeo , Sakakura Chouhei , Shirasu Morio , Torii Tsuyoshi , Hirata Youichi , Yamagishi Hisakazu
Published: April 2006

We describe the procedure and examine the therapeutic efficacy of a combination of sigmoidofiberscopic incision plus balloon dilatation for tubular stricture by thick, long scar tissue at the colorectal anastomosis after anterior resection for rectal cancer. Balloon dilatation alone does not always relieve the strictures, although this method is the usual therapy for this condition. Five patients were identified in whom the stricture was not improved with balloon dilatation alone. Of these five patients, three complained of difficulty defecating, a feeling of incomplete evacuation, residual feces, and lower abdominal fullness. The remaining two patients, who had transverse colostomy to treat major leakage at the anastomosis, showed no symptoms. All five patients underwent the combination therapy described below. Two or three small radial incisions were made in the scar of the stricture with electrocautery under fiberscopic vision. Then the strictural scar was split and loosened bluntly along the incisions over a 15‐ to 20‐minute period with a balloon dilator. This procedure was performed once or twice at a 2‐week interval. In all five patients the stricture was improved according to objective criteria. There was also an improvement in the subjective symptoms suffered by three patients. The improvements were maintained over observation periods of 9 to 15 months. No complications were observed. Sigmoidofiberscopic incision plus balloon dilatation is an effective, safe therapy for cicatricial strictures after anterior resection for rectal cancer when the strictures have failed to improve following balloon dilatation alone.
Solutions nodales sur les variétés Riemanniennes non localement conformément plates à bord
Authors: Holcman D.
Published: April 2006

Dans cet article, on considère le problème de Dirichlet pour une EDP non linéaire avec une donnée au bord qui change de signe. L'existence d'une famille de solutions minimisantes est obtenue sur les variétés riemaniennes compactes non localement conformément plates à bord. This paper deals with solutions of Dirichlet problem for a nonlinear PDE with boundary data changing of sign. A family of minimizing nodal solutions are found on nonlocally conformally flat manifolds with boundary.
Une formule de Plancherel pour l'algèbre de Hecke d'un groupe réductif p-adique
Authors: Heiermann V.
Published: April 2006

Nous montrons un théorème de Paley-Wiener matriciel pour l'algèbre de Hecke d'un groupe réductif p-adique. La preuve est basée sur une analogue de la formule de Plancherel.
On triangular billiards
Authors: Puchta Jean-Christoph
Published: April 2006

We prove a conjecture of Kenyon and Smillie concerning the nonexistence of acute rational-angled triangles with the lattice property.
Constitutive activation of the jasmonate signaling pathway enhances the production of secondary metabolites in tomato
Authors: Chen Hui , Jones A. Daniel , Howe Gregg A.
Published: April 2006

The phytohormone jasmonic acid (JA) regulates the synthesis of secondary metabolites in a wide range of plant species. Here, we show that exogenous methyl‐JA (MeJA) elicits massive accumulation of caffeoylputrescine (CP) in tomato leaves. A mutant (jai1) that is defective in jasmonate perception failed to accumulate CP in flowers and MeJA‐treated leaves. Conversely, a transgenic tomato line (called 35S::PS) that exhibits constitutive JA signaling accumulated high levels of leaf CP in the absence of jasmonate treatment. RNA blot analysis showed that genes encoding enzymes in the phenylpropanoid and polyamine pathways for CP biosynthesis are upregulated in MeJA‐treated wild‐type plants and in untreated 35S::PS plants. These results indicate that CP accumulation in tomato is tightly controlled by the jasmonate signaling pathway, and provide proof‐of‐concept that the production of some plant secondary metabolites can be enhanced by transgenic manipulation of endogenous JA levels.
Suppression of Mycobacterium tuberculosis induced reactive oxygen species (ROS) and TNF‐α mRNA expression in human monocytes by allicin
Authors: Hasan Nazarul , Yusuf Nabiha , Toossi Zahra , Islam Najmul
Published: April 2006

Chronic inflammation associated with tumor necrosis factor (TNF)‐α and reactive oxygen species (ROS) is the hallmark of tuberculosis. Mycobacterium tuberculosis (MTB) directly stimulates human monocytes to secrete TNF‐α. We show the augmented expression of TNF‐α mRNA in MTB‐infected monocytes by cellular activation and ROS was suppressed by allicin in a dose‐dependent manner. Also, allicin enhanced the glutathione peroxidase activity, which correlated inversely with the downregulation of ROS and TNF‐α in MTB‐infected monocytes. Hence, allicin may prove to be a valuable natural antioxidant in combating tuberculosis.
Cytotoxicity of albebetin oligomers depends on cross‐β‐sheet formation
Authors: Zamotin Vladimir , Gharibyan Anna , Gibanova Natalia V. , Lavrikova Marika A. , Dolgikh Dmitry A. , Kirpichnikov Michail P. , Kostanyan Irina A. , Morozova-Roche Ludmilla A.
Published: April 2006

Prefibrillar cytotoxicity was suggested as a common amyloid characteristic. We showed two types of albebetin prefibrillar oligomers are formed during incubation at pH 7.3. Initial round‐shaped oligomers consist of 10–15 molecules determined by atomic force microscopy, do not bind thioflavin‐T and do not affect viability of granular neurons and SH‐SY5Y cells. They are converted into ca. 30–40‐mers possessing cross‐β‐sheet and reducing viability of neuronal cells. Neither monomers nor fibrils possess cytotoxicity. We suggest that oligomeric size is important for stabilising cross‐β‐sheet core critical for cytotoxicity. As albebetin was used as a carrier‐protein for drug delivery, examination of amyloidogenicity is required prior polypeptide biomedical applications.