bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship of plasma Dendroaspis natriuretic peptide‐like immunoreactivity and echocardiographic parameters in chronic haemodialysis patients
Authors: LEE SIK , PARK SUNG K , KANG KYUNG P , KANG SUNG K , KIM SUNG Z , KIM WON
Published: June 2004

Background and Aims:  The Dendroaspis natriuretic peptide (DNP), which was recently isolated from the venom of the green Mamba snake, Dendroaspis angusticeps, is a 38 amino acid peptide containing a 17 amino acid disulfide ring structure. The purpose of this study was to evaluate the effect of haemodialysis (HD) on the plasma concentration of DNP, and to investigate the relationship between the 2‐D echocardiographic parameters and the changes in the plasma DNP levels during HD.

Methods:  Forty‐five haemodialysis patients and 22 healthy individuals underwent a measurement of plasma DNP‐like immunoreactivity, serum creatinine, haematocrit, blood pressure and bodyweight before and after each HD session. Echocardiography was performed before and after HD. The peak early diastolic transmitral flow velocity (E), peak late diastolic transmitral flow velocity (A), and E/A ratio were measured by using a pulsed Doppler echocardiogram.

Results:  The plasma DNP‐like immunoreactivity of those in the pre‐HD state was significantly higher (235.6 ± 45.8 pg/mL) than those of the healthy subjects (105.3 ± 31.1 pg/mL). In addition, the plasma DNP‐like immunoreactivity was significantly decreased after HD (204.4 ± 55.4 pg/mL). The left atrial diameter, left ventricular diameter at end diastole and end systol, E velocity, A velocity, E/A ratio and inferior vena cava diameter were significantly decreased after HD. There were significant correlations between the changes of plasma DNP‐like immunoreactivity and the changes in the bodyweight and inferior vena cava diameter, respectively.

Conclusion:  These results suggest that the plasma DNP‐like immunoreactivity might be involved in the regulation of the blood volume in patients undergoing HD.
Avoidance of direct injury to the peripheral nerve with maxacalcitol (22oxa‐1,25(OH)2D3) in rats
Authors: NAKAMURA MICHIO , FUCHINOUE SHOHEI , TERAOKA SATOSHI
Published: June 2004

Background:  Secondary hyperparathyroidism is one of the most common complications in patients with long‐term end‐stage renal disease. A recent report has stated that high doses of vitamin D derivatives injected directly into the parathyroid glands can reduce serum parathyroid hormone levels and suppress further enlargement of the parathyroid glands without side‐effects. Maxacalcitol (22oxa‐1,25(OH)2D3; OCT) is a new vitamin D derivative that can be administered intravenously, and is available in Japan. Direct injection of OCT into enlarged parathyroid glands is a promising new treatment for moderate renal hyperparathyroidism. It is considered to be safe for surrounding tissues, such as peripheral nerves, but the actual effects of OCT on nerves have not yet been documented.

Methods:  We measured nerve conduction velocity (NCV) in 24 rat femoral nerves soaked in saline, ethanol, or OCT at various concentrations. Nerves from each group (saline, ethanol, OCT groups) were also examined by microscopy.

Results:  The mean NCV of rat femoral nerves was 33.67 ± 1.39 m/s in the saline group. In the OCT group, the velocities were not changed at any of the concentrations tested, and there were no significant differences in NCVs between the saline and OCT groups. In the 50% ethanol group, the velocity decreased significantly to 8.98 ± 4.78 m/s (P < 0.01). A histological study demonstrated the nerves soaked in OCT at 10 µg/mL to essentially be intact, while those soaked in anhydrous ethanol were damaged.

Conclusions:  This study demonstrated that OCT administration does not affect peripheral NCV, indicating that OCT could possibly be used for the treatment of moderate renal hyperparathyroidism safely without nerve damage.
Haemoglobin response to subcutaneous versus intravenous epoetin alfa administration in iron‐replete haemodialysis patients
Authors: LEIKIS MURRAY J , KENT ANNETTE B , BECKER GAVIN J , MCMAHON LAWRENCE P
Published: June 2004

Background:  Numerous prior studies have reported that a substantially higher dose of epoetin is required to maintain haemoglobin (Hb) concentration when patients are switched from a subcutaneous (SC) to intravenous (IV) route of administration. Many of the reported trials, however, involved patients who did not have adequate serum iron levels. It was hypothesized that patients with adequate iron stores who are switched from one route of administration to the other without a change in dose will experience substantially less change in their Hb concentration.

Methods:  Haemodialysis patients who were iron replete (ferritin 300–800 µg/L, transferrin saturation (TSAT) 25–50%) participated in a prospective, randomized cross‐over trial receiving epoetin for 3 months either by SC or IV injection followed by a further 3 months of epoetin via the other route. The principal aim was to determine changes in Hb concentration without altering the weekly epoetin dose. The secondary aim was to assess whether the frequency of dosing (once, twice or thrice weekly) influenced the Hb concentration response.

Results:  Eighty‐one patients (mean age 62 years, 60% male) entered the study and 15 withdrew prior to study completion. Forty‐three patients began SC epoetin alfa administration (group A) and 38 on IV (group B). Median ferritin and TSAT at entry for groups A and B were 409 and 394 µg/L (NS) and 31 and 32% (NS), respectively, which remained within the target range during the study. Median epoetin doses for groups A and B were similar (90 vs 93 IU/kg per week, NS). After 3 months, the mean Hb concentration rose for group A (SC; 118.7–121.9 g/L (P = 0.03)) but it fell for group B (IV; 119.1–116.0 g/L (P = 0.019)). Following the change in route of administration, the Hb concentration for group A (IV) fell by 5.1% over 3 months (121.9–115.4, P < 0.001) and rose by 2.8% for group B (SC) over 3 months (116.0–119.7, P = 0.001). Similar significant changes in the Hb concentration were seen at different dosing frequencies.

Conclusion:  Subcutaneuos administration of epoetin produces a significant, although slight clinical change in Hb concentration compared with IV administration in stable, iron replete, haemodialysis patients. A similar effect appears to prevail regardless of the frequency of injections given.
Interaction between morphology and angiogenesis in human early colorectal cancers
Authors: Okada Keiichiro , Satoh Toshimi , Fujimoto Kazuma , Tokunaga Osamu
Published: June 2004

Morphologically, early colorectal cancers are divided into two types: polypoid cancers and non‐polypoid cancers. They vary in growth pattern, progression, and genetic alteration. Angiogenesis between polypoid and non‐polypoid cancers may also be different. Therefore, the present study aims to evaluate angiogenesis in the early stages of colorectal malignancy, with particular attention to the morphological differences. The serial slides of all materials (48 polypoid cancers, 10 non‐polypoid cancers, 20 adenomas and 10 normal tissues) were immunohistochemically stained for three endothelial cell markers (CD31, von Willebrand factor and CD105), counted for the number of microvessels in the same hot spots, and the angiogenic status was estimated. Polypoid cancers had higher microvessel counts and were more predominantly supplied by activated (CD105‐positive, newly forming) microvessels than non‐polypoid cancers. The present study indicated the possibility that the difference in growth pattern might be explained by the difference in angiogenesis between polypoid and non‐polypoid cancers.
Autopsy case of congenital pulmonary lymphangiectasis
Authors: Hirano Hiroshi , Nishigami Takashi , Okimura Akira , Nakasho Keiji , Uematsu Kunio
Published: June 2004

Congenital pulmonary lymphangiectasis (CPL) is a rare anomaly. We report a female infant born at 39 weeks of gestation who was found to have CPL. Cyanosis and tachypnea were noted immediately after birth, and, at room air, PaO2 was 30.7 mmHg, PaCO2 was 82.5 mmHg and pH was 7.12. The infant's symptoms did not improve even with the initiation of artificial ventilation. Chest X‐ray film showed cotton‐like infiltrates in both lungs and an air‐leak surrounding the cardiac shadow. Echocardiography study showed no abnormality. The neonate died 3 days after birth due to hypoxemic cardiac failure. At autopsy, the pleural surface contained numerous dilated vessels that had the appearance of lymphatics. Microscopic features of the lungs were marked lymphatic dilatation of the perivascular, subpleural and interlobular areas. Lymphangiectasis was found in the liver, kidney, pancreas, thyroid and alimentary canals, such as the esophagus, stomach and rectum. Patients with lymphatic dilatations in extrapulmonary organs have mild pulmonary involvement and symptoms and a better prognosis. However, a few cases of CPL with lymphatic dilatations in extrapulmonary organs and an aggressive course, such as the present case, have been reported. The clinical behavior and prognosis of CPL depend on the extent of pulmonary involvement of the lymphatic dilatations regardless of systemic lymphatic dilations.
Spontaneous regression of malignant lymphoma of the breast
Authors: Iihara Kuniko , Yamaguchi Kazuyoshi , Nishimura Yu , Iwasaki Takuya , Suzuki Ken , Hirabayashi Yasuko
Published: June 2004

A complete spontaneous regression of diffuse large B cell lymphoma involving the right breast, confirmed by aspiration cytology, is reported. The patient visited a hospital due to the rapid growth of a tumor in the right breast. Five years previously she underwent a craniotomy for a brain tumor, diagnosed as B‐cell malignant lymphoma, and received several courses of irradiation to the brain. Analysis of the breast tumor cells obtained by aspiration revealed lymphoma cells morphologically, which were similar to the tumor cells in the brain expressing CD20. While waiting for further examination, the tumor regressed rapidly and was not palpable after 20 days. An excisional biopsy of the breast exhibited no definite malignant lymphoma cells among a diffuse population of CD45RO and CD8‐positive small lymphocytes. Nucleotide sequencing of HCDR3s of the brain tumor and breast tumor cells showed a completely matched sequence, revealing the breast mass to be a metastatic lesion from the tumor of the brain. Although there was no tumorous lesion, the patient received additional chemotherapy and has shown no sign of recurrence in the breast for 7 years. We were able to confirm that the breast lymphoma shown in the aspiration cytology was a metastatic one, which was not proven histologically prior to chemotherapy, and regard the present case as a malignant lymphoma of the breast showing spontaneous regression. The present case shows a rare occurrence of spontaneous regression of diffuse large B cell malignant lymphoma after aspiration and suggests that CD8‐positive T cells might be related to the regression.
Acute inflammatory reactions caused by histamine via monocytes/macrophages chronically participate in the initiation and progression of atherosclerosis
Authors: Kimura Satoshi , Wang Ke‐Yong , Tanimoto Akihide , Murata Yoshitaka , Nakashima Yasuhide , Sasaguri Yasuyuki
Published: June 2004

Previously we demonstrated that histidine decarboxylase (HDC), which produces histamine from l‐histidine, was detected in monocytes/macrophages located in human atherosclerotic lesions. As monocytic migration is a key event of atherogenesis, we investigated whether histamine induces monocytic expression of monocyte chemoattractant protein (MCP)‐1 and its receptors CCR2‐A and ‐B, and also endothelial expression of ICAM‐1 and VCAM‐1. Furthermore, we studied the effect of interleukin (IL)‐4, which inhibits the HDC expression, on the expression of MCP‐1 and CCR2. Histamine stimulated monocytes, but not macrophages, to express MCP‐1 and CCR2‐A and ‐B. The expression of MCP‐1 was inhibited by histamine H2 blocker. In contrast, IL‐4 enhanced CCR2 expression but not MCP‐1. Histamine stimulated endothelial cells to express ICAM‐1 and VCAM‐1. These results indicate that histamine and IL‐4, which are both synthesized in the arterial intima, chronically participates in the pathogenesis of atherosclerosis via the enhanced expression of monocytic MCP‐1, CCR2 and endothelial adhesion molecules.
Cooperative interactions among p53, bcl‐2 and Epstein–Barr virus latent membrane protein 1 in nasopharyngeal carcinoma cells
Authors: Sheu Lai‐Fa , Chen An , Lee Herng‐Sheng , Hsu Hsue‐Yin , Yu Da‐Shung
Published: June 2004

Interactions among p53, bcl‐2 and Epstein–Barr virus (EBV) latent membrane protein 1 (LMP1) in nasopharyngeal carcinoma (NPC) cells were evaluated by gene cotransfections. The data showed that bcl‐2 expression was not only able to prevent the growth suppression induced by wild‐type p53 but was also paradoxically able to inhibit the growth enhancement induced by mutant p53. Latent membrane protein 1 was shown to be capable of overcoming the growth inhibition induced by wild‐type p53 and the synergistic cooperation with bcl‐2 to enhance cellular growth. Latent membrane protein 1 could also cooperate with mutant p53 to provide a growth advantage for NPC cells. Most NPC revealed detectable overexpression of p53, and the majority of those were a wild type possibly responding to EBV infection. The coexpression of bcl‐2 and LMP1 was thought to inhibit the growth suppression induced by wild‐type p53 in NPC. But there was no associated expression between LMP1 and bcl‐2 because we demonstrated that transfected LMP1 failed to induce bcl‐2 expression in NPC cells in contrast to the findings in B cells. It is theorized that the cooperative expression of bcl‐2 and LMP1 exists in the majority of NPC, while a minority of NPC have cooperative expression of LMP1 and mutant p53. Each cooperative interaction could play an important role in the development and progression of NPC.
Inactivation of the p16 gene by hypermethylation and loss of heterozygosity in adenocarcinoma of the lung
Authors: Awaya Hirokazu , Takeshima Yukio , Amatya Vishwa Jeet , Furonaka Osamu , Tagawa Kohei , Kohno Nobuoki , Inai Kouki
Published: June 2004

We investigated the aberrant promoter hypermethylation of p16, p15 and p14 genes and loss of heterozygosity (LOH) at 9p21–22 in 48 cases of adenocarcinoma of the lung. The frequencies of hypermethylation of genes were as follows: p16, 25.0%; p15, 22.9%; and p14, 18.8%. The frequency of LOH at chromosome 9p21–22 was 60.9%. The frequency of two‐hit inactivation of the p16 gene by hypermethylation and LOH was 21.7%. Two‐hit inactivation of the p16 gene showed loss of protein expression and was significantly correlated with tumor size, tumor grade and the Ki‐67 labeling index. Hypermethylation of the p16 gene was not significantly correlated with hypermethylation of the p15 and p14 genes, both of which are close to the p16 gene locus, suggesting that hypermethylation of these genes occurs selectivity. In conclusion, biallelic inactivation of the p16 gene by hypermethylation and LOH might cause loss of p16 expression and play an important role in the development of adenocarcinoma of the lung. Therefore, controlling and monitoring for hypermethylation of the p16 gene may be partially useful for treatment and early diagnosis of adenocarcinoma of the lung.
Frequent expression of CD30 antigen in the primary gastric non‐B, non‐Hodgkin lymphomas
Authors: Iwamizu‐Watanabe Sachiko , Yamashita Yoriko , Yatabe Yasushi , Nakamura Shigeo , Mori Naoyoshi
Published: June 2004

Most primary gastric lymphomas are of B‐cell origin. Fourteen cases of primary gastric non‐B, non‐Hodgkin lymphomas were studied to evaluate their clinicopathological and immunophenotypic findings. The cases were comprised of 11 men and three women, with a median age of 56.5 years. Most patients underwent surgery either with or without chemotherapy, exhibiting a 5 year survival rate of 57.5%. Morphologically, the neoplastic cells showed various histological features, such as anaplastic large cell lymphoma (ALCL) (n = 3), peripheral T‐cell lymphoma, unspecified, large (n = 4), medium‐sized (n = 2) and mixed cell (n = 5). Two cases displayed a non‐B, non‐T cell phenotype, whereas the remaining cases displayed a T‐cell phenotype. Six cases were CD4+, while two were CD8+. The neoplastic cells were CD30+ in 10 cases. TIA‐1 was positive in six cases. In one case, anaplastic large cell lymphoma kinase (ALK) was identified with immunostaining and chromosomal rearrangement of ALK was detected by fluorescence in situ hybridization (FISH). In conclusion, although the mechanism of CD30 expression is unknown, primary gastric non‐B, non‐Hodgkin lymphomas tend to express CD30. We consider that some of the cases in the present study may be derived from cytotoxic T cells, similar to systemic and cutaneous ALCL, the majority of which exhibit TIA‐1.
Estrogen receptor is significantly associated with the epithelioid variants of renal angiomyolipoma: A clinicopathological and immunohistochemical study of 67 cases
Authors: Cho Nam Hoon , Shim Hyo Sub , Choi Young Deuk , Kim Dong Suk
Published: June 2004

Perivascular epithelioid cells (PEC) in angiomyolipoma (AML) were recently proposed to be its most common progenitor cells. Histologically, triphasic components were present in various proportions, but were overwhelmingly myogenic in epithelioid variants of AML. Despite histological discrimination, the immunophenotypic profiles between triphasic and epithelioid AML have never been compared. The aim of the present study was to clarify the identity of PEC by using immunoreactivity to estrogen receptor (ER), progesterone receptor (PR), bcl‐2 and placenta alkaline phosphatase (PLAP), and to use this information to compare triphasic and epithelioid AML. A total of 33 out of 67 cases of renal angiomyolipoma that underwent surgery were reviewed over the period 1998–2003. Two cases were associated with tuberous sclerosis. Ten patients had other malignant tumors, and three patients had a nodal extension. Immunohistochemistry showed that bcl‐2 (59.4%), PLAP (46.9%), HMB‐45 (100%) was predominantly localized around vessels. The stem cell markers were absolutely negative in all AML types. The estrogen receptors were positive in 14 cases (42.4%) and the progesterone receptors were positive in five cases. Bcl‐2 and both female sex hormone receptors were significantly more frequent in the epithelioid variant of AML than in the triphasic type. Perivascular epithelioid cells express bcl‐2, ER, PR and PLAP, and ER could be partly associated with myogenic proliferation.
Chorionic plate vessels as an origin of amniotic fluid neutrophils
Authors: Lee Soong Deok , Kim Mi Ran , Hwang Pil Gyu , Shim Soon‐Sup , Yoon Bo Hyun , Kim Chong Jai
Published: June 2004

The present study was conducted to investigate the potential anatomical source of amniotic fluid neutrophils. Microdissection of neutrophils from the chorioamnion of the fetal membranes and the amnion of the chorionic plates of 10 preterm placentas with acute chorioamnionitis was performed and the genotypes of the neutrophils were compared with those of the mother and fetus using polymerase chain reaction of nine autosomal STR loci. In separate analyses, we reviewed eight cases of fetal autopsies with increased amniotic fluid neutrophils for the presence of neutrophils in the alveoli, and also analyzed the relationship between the amniotic fluid white blood cell (WBC) count and the histological pattern of placental inflammation. The genotypes of all of the neutrophils found in the chorioamnion of the fetal membrane matched those of the mother (n = 10). The genotypes of neutrophils found in the chorionic plate were of mixed maternal and fetal origin (n = 4). In the autopsy series of the fetuses with amniotic fluid WBC (n = 8), only five cases showed neutrophils in the alveolar space, while all the placentas had chorioamnionitis. There was no significant difference in amniotic fluid WBC count between the cases with or without acute membranitis, while among the cases with placental inflammation, those with inflammation of the chorionic plate had a significantly higher amniotic fluid WBC count than both the membranitis‐only cases (P < 0.001) and the membranitis and funisitis cases (P < 0.05). These results imply that fetal vasculature at the chorionic plate is the main source of amniotic fluid neutrophils, especially in the cases without funisitis.
Gardner's syndrome associated fibromas
Authors: Michal Michal , Boudova Ludmila , Mukensnabl Petr
Published: June 2004

Three patients with Gardner's syndrome having benign fibrous proliferations in the soft tissues and the oral cavity are presented. Lesions in all three patients were morphologically different. Two excised lesions in Case 1 were histologically identical to nuchal‐type fibroma (NTF) and one lesion in this patient was an epidermal cyst. Case 2 had a lesion located in the soft tissues of the shoulder, which was morphologically similar to NTF and, in addition, contained mildly atypical and multinucleated fibroblastic cells. The oral lesion in Case 3 looked like a fibroma and was morphologically different from all fibrous lesions that have ever been described in Gardner's syndrome. The cases in the present report show that the term Gardner's fibroma is just a descriptive name encompassing a spectrum of morphologically different benign fibrous proliferations associated with this syndrome. Therefore, the term Gardner's fibroma should not be used as a specific name for NTF arising in patients with Gardner's syndrome as suggested in the most recent WHO classification of soft tissue and bone tumors.
Lipoma‐like tumor mass probably arising in the retroperitoneal heterotopic pancreas: A previously undescribed lesion
Authors: Moriki Toshiaki , Ohtsuki Yuji , Takahashi Tamotsu , Ueta Shousuke , Mitani Miko , Ichien Miho , Fukata Satoshi , Murata Yoriko
Published: June 2004

Heterotopic pancreatic tissue is found in several locations of the body. However, to the best of our knowledge, there have been no reports on heterotopic pancreas in the retroperitoneum. A case of retroperitoneal lipoma‐like large tumor mass probably arising in the heterotopic pancreas is reported. A 45‐year‐old Japanese woman was admitted to hospital because of back pain. Imaging modalities showed an abnormal mass in the retroperitoneum separate from the surrounding organs, including the pancreas and kidney. Histologically, the mass consisted of mature adipose tissue and scattered ductal and acinar elements. Although there was no islet tissue in this fatty mass, the epithelial elements suggested heterotopic pancreatic tissue in origin. The present case is very unusual; however, heterotopic pancreas should be considered in the differential diagnosis of retroperitoneal tumors.
Meningioma in mature cystic teratoma of the ovary
Authors: Takeshima Yukio , Kaneko Mayumi , Furonaka Osamu , Jeet Amatya V. , Inai Kouki
Published: June 2004

A case of meningioma arising in a mature cystic teratoma of the ovary in a 60‐year‐old woman is described. The tumor was located in the right ovary, and salpingo‐oophorectomy was performed. The right ovary was 10 × 10 × 8 cm in size and contained an unilocular cyst. In the wall, a solid nodule measuring 3 × 3 × 2 cm was noted. Histologically, the cyst wall was composed of typical mature cystic teratoma. In contrast, the mural nodule was composed of the proliferating spindle‐ and polygonal‐shaped cells showing positive staining for epithelial membrane antigen and microcystic change was prominent. These findings were consistent with microcystic meningioma. The arachnoidal cells around mature brain tissue may be the origin of this unusual tumor. To the best of our knowledge, this is the first case of mature cystic teratoma with meningioma of the ovary reported in English medical literature. This case may further indicate the totipotential nature of mature cystic teratoma.
Mycorrhizal networks mediate overstorey‐understorey competition in a temperate forest
Authors: Booth Michael G.
Published: June 2004

In forests, common mycorrhizal networks (CMNs) often connect the roots of neighbouring plants. Observations of material flows between hosts connected by CMNs have given rise to the hypothesis that CMNs limit the negative effects of competition by overstorey trees on seedlings recruiting underneath them. I conducted an experiment in a temperate forest dominated by ectomycorrhizal conifers and hardwoods to isolate the effects of CMNs on the growth and survival of four tree species that co‐occur in the understorey. Ectomycorrhizal networks had strong negative effects on the survival of an arbuscular mycorrhizal species, Acer rubrum, and neutral effects on the survival of three ectomycorrhizal species, Betula allegheniensis, Pinus strobus, and Tsuga canadensis. CMNs had positive effects on the growth of at least one ectomycorrhizal species, P. strobus. Interspecific differences in juvenile responses to CMNs may influence forest community development, promoting coexistence of some tree species while limiting the success of others.
Detritus, trophic dynamics and biodiversity
Authors: Moore John C. , Berlow Eric L. , Coleman David C. , de Ruiter Peter C. , Dong Quan , Hastings Alan , Johnson Nancy Collins , McCann Kevin S. , Melville Kim , Morin Peter J. , Nadelhoffer Knute , Rosemond Amy D. , Post David M. , Sabo John L. , Scow Kate M. , Vanni Michael J. , Wall Diana H.
Published: June 2004

Traditional approaches to the study of food webs emphasize the transfer of local primary productivity in the form of living plant organic matter across trophic levels. However, dead organic matter, or detritus, a common feature of most ecosystems plays a frequently overlooked role as a dynamic heterogeneous resource and habitat for many species. We develop an integrative framework for understanding the impact of detritus that emphasizes the ontogeny and heterogeneity of detritus and the various ways that explicit inclusion of detrital dynamics alters generalizations about the structure and functioning of food webs. Through its influences on food web composition and dynamics, detritus often increases system stability and persistence, having substantial effects on trophic structure and biodiversity. Inclusion of detrital heterogeneity in models of food web dynamics is an essential new direction for ecological research.
Biodiversity effects increase linearly with biotope space
Authors: Dimitrakopoulos Panayiotis G. , Schmid Bernhard
Published: June 2004

Understanding the influence of environmental variation on the relationship between biodiversity and ecosystem functioning is of theoretical and practical interest. We predicted that the strength of this relationship should increase with available biotope space (the physical space associated with a species’ niche) due to increased niche complementarity between species. In this study, biotope space specifically refers to soil volume which is associated with the niche dimension of nutrient acquisition. We tested our prediction by growing plant communities on a gradient of increasing soil depth and volume, offering increased rooting space to species. Our results provide support for a linear increase of the magnitude of positive biodiversity effects on above‐ and belowground community biomass with increasing biotope space. This increase was caused by complementarity effects between species. Soil erosion may thus reduce intercropping benefits.
Testing the energetic equivalence rule with helminth endoparasites of vertebrates
Authors: George‐Nascimento Mario , Muñoz Gabriela , Marquet Pablo A. , Poulin Robert
Published: June 2004

As a general test of the energetic equivalence rule, we examined macroecological relationships among abundance, density and host body mass in a comparative analysis of the assemblages of trophically transmitted endoparasitic helminths of 131 species of vertebrate hosts. Both the numbers and total volume of parasites per gram of host decreased allometrically with host body mass, with slopes roughly consistent with those expected from the allometric relationship between host basal metabolic rate and body mass. From an evolutionary perspective, large body size may therefore allow hosts to escape from the deleterious effects of parasitism.
Parasites in the food web: linking amphibian malformations and aquatic eutrophication
Authors: Johnson Pieter T. J. , Chase Jonathan M.
Published: June 2004

Emerging diseases are an ever‐growing affliction of both humans and wildlife. By exploring recent increases in amphibian malformations (e.g. extra or missing limbs), we illustrate the importance of food web theory and community ecology for understanding and controlling emerging infections. Evidence points to a native parasite,Ribeiroia ondatrae, as the primary culprit of these malformations, but reasons for the increase have remained conjectural. We suggest that the increase is a consequence of complex changes to aquatic food webs resulting from anthropogenic disturbance. Our results implicate cultural eutrophication as a driver of elevated parasitic infection: (1) eutrophication causes a predator‐mediated shift in snail species composition towardPlanorbellaspp., (2)Planorbellaare the exclusive first intermediate hosts ofR. ondatraeand (3)Ribeiroiainfection is a strong predictor of amphibian malformation levels. Our study illustrates how the effects of anthropogenic disturbance on epidemic disease can be mediated through direct and indirect changes in food web structure.
Intraguild predation: a widespread interaction related to species biology
Authors: Arim Matías , Marquet Pablo A.
Published: June 2004

Intraguild predation (IGP), defined as killing and eating among potential competitors, seems to be a ubiquitous interaction, differing from competition or predation. In the present study we assess the frequency of IGP among 763 potential intraguild prey and 599 potential intraguild predators. Our results indicate that IGP is common in nature, reaching frequencies between 58.4 and 86.7%. A null model suggests that IGP in different groups of predators and prey (i.e. carnivores, omnivores, herbivores, detritivores, or top and intermediate species) have different deviations from a chance expectation, indicating these attributes of species biology as main determinants of IGP persistence. We suggest that IGP satisfies two basic requirements to be considered as important to the trophic structuring of communities. First, its occurrence is not random, rather it is associated with well‐defined attributes of species biology, and secondly, it is a widespread interaction.
Limited filling of the potential range in European tree species
Authors: Svenning Jens‐Christian , Skov Flemming
Published: June 2004

The relative roles of environment and history in controlling large‐scale species distributions are important not only theoretically, but also for forecasting range responses to climatic change. Here, we use atlas data to examine the extent to which 55 tree species fill their climatically determined potential ranges in Europe. Quantifying range filling (R/P) as realized/potential range size ratios using bioclimatic envelope modelling we find meanR/P = 38.3% (±30.3% SD). Many European tree species naturalize extensively outside their native ranges, providing support for interpreting the many lowR/Ps as primarily reflecting dispersal limitation.R/Pincreases strongly with latitudinal range centroid and secondarily with hardiness and decreases weakly with longitudinal range centroid. Hence, European tree species ranges appear strongly controlled by geographical dispersal constraints on post‐glacial expansion as well as climate. Consequently, we expect European tree species to show only limited tracking of near‐future climate changes.
Genetic organization of the catabolic plasmid pJP4 from Ralstonia eutropha JMP134 (pJP4) reveals mechanisms of adaptation to chloroaromatic pollutants and evolution of specialized chloroaromatic degradation pathways
Authors: Trefault N. , De la Iglesia R. , Molina A. M. , Manzano M. , Ledger T. , Pérez‐Pantoja D. , Sánchez M. A. , Stuardo M. , González B.
Published: June 2004

Ralstonia eutropha JMP134 (pJP4) is a useful model for the study of bacterial degradation of substituted aromatic pollutants. Several key degrading capabilities, encoded by tfd genes, are located in the 88 kb, self‐transmissible, IncP‐1 β plasmid pJP4. The complete sequence of the 87 688 nucleotides of pJP4, encoding 83 open reading frames (ORFs), is reported. Most of the coding sequence corresponds to a well‐conserved IncP‐1 β backbone and the previously reported tfd genes. In addition, we found hypothetical proteins putatively involved in the transport of aromatic compounds and short‐chain fatty acid oxidation. ORFs related to mobile elements, including the Tn501‐encoded mercury resistance determinants, an IS1071‐based composite transposon and a cryptic class II transposon, are also present in pJP4. These mobile elements are inefficient in transposition and are located in two regions of pJP4 that are rich in remnants of lateral gene transfer events. pJP4 plasmid was able to capture chromosomal genes and form hybrid plasmids with the IncP‐1 α plasmid RP4. These observations are integrated into a model for the evolution of pJP4, which reveals mechanisms of bacterial adaptation to degrade pollutants.
High overall diversity and dominance of microdiverse relationships in salt marsh sulphate‐reducing bacteria
Authors: Klepac‐Ceraj Vanja , Bahr Michele , Crump Byron C. , Teske Andreas P. , Hobbie John E. , Polz Martin F.
Published: June 2004

The biogeochemistry of North Atlantic salt marshes is characterized by the interplay between the marsh grass Spartina and sulphate‐reducing bacteria (SRB), which mineralize the diverse carbon substrates provided by the plants. It was hypothesized that SRB populations display high diversity within the sediment as a result of the rich spatial and chemical structuring provided by Spartina roots. A 2000‐member 16S rRNA gene library, prepared with delta‐proteobacterial SRB‐selective primers, was analysed for diversity patterns and phylogenetic relationships. Sequence clustering detected 348 16S rRNA sequence types (ribotypes) related to delta‐proteobacterial SRB, and it was estimated that a total of 623 ribotypes were present in the library. Similarity clustering showed that ≈ 46% of these sequences fell into groups with < 1% divergence; thus, microheterogeneity accounts for a large portion of the observable genetic diversity. Phylogenetic comparison revealed that sequences most frequently recovered were associated with the Desulfobacteriaceae and Desulfobulbaceae families. Sequences from the Desulfovibrionaceae family were also observed, but were infrequent. Over 80% of the delta‐proteobacterial ribotypes clustered with cultured representatives of Desulfosarcina, Desulfococcus and Desulfobacterium genera, suggesting that complete oxidizers with high substrate versatility dominate. The large‐scale approach demonstrates the co‐existence of numerous SRB‐like sequences and reveals an unexpected amount of microdiversity.
Occurrence and distribution of Vibrio cholerae in the coastal environment of Peru
Authors: Gil Ana I. , Louis Valérie R. , Rivera Irma N. G. , Lipp Erin , Huq Anwar , Lanata Claudio F. , Taylor David N. , Russek‐Cohen Estelle , Choopun Nipa , Sack R. Bradley , Colwell Rita R.
Published: June 2004

The occurrence and distribution of Vibrio cholerae in sea water and plankton along the coast of Peru were studied from October 1997 to June 2000, and included the 1997–98 El Niño event. Samples were collected at four sites in coastal waters off Peru at monthly intervals. Of 178 samples collected and tested, V. cholerae O1 was cultured from 10 (5.6%) samples, and V. cholerae O1 was detected by direct fluorescent antibody assay in 26 out of 159 samples tested (16.4%). Based on the number of cholera cases reported in Peru from 1997 to 2000, a significant correlation was observed between cholera incidence and elevated sea surface temperature (SST) along the coast of Peru (P < 0.001). From the results of this study, coastal sea water and zooplankton are concluded to be a reservoir for V. cholerae in Peru. The climate–cholera relationship observed for the 1997–98 El Niño year suggests that an early warning system for cholera risk can be established for Peru and neighbouring Latin American countries.
Bacteria and viruses in the water column of tropical freshwater reservoirs
Authors: Peduzzi Peter , Schiemer Fritz
Published: June 2004

In tropical freshwater reservoirs of Sri Lanka, which are linked in an aquatic network, bacterial abundance and production as well as virus abundance, frequency of viral infection and virus production were investigated together with a set of nutrient species (Kjeldahl‐N, NO3‐N, total P, soluble P, PO4‐P). At two characteristic seasons (wet season, dry season), samples were taken from two types of reservoirs (new upland impoundment and ancient, shallow lowland reservoir), each during 4 days at various depths of the entire water columns. Kjeldahl‐N and total P were greatly elevated in the wind‐mixed water body of the shallow impoundment during the dry season, whereas the deeper reservoir type exhibited no obvious seasonality. In SYBR green™‐stained samples, bacterial abundance showed no seasonal pattern in either reservoir type. Bacterial secondary production, however, was significantly elevated in the entire water column of the shallow impoundment under wind‐mixed conditions in the dry season. Highest abundance of virus particles and elevated frequency of bacteria containing mature phages were also observed in the shallow reservoir during the dry season indicating favourable conditions for virus propagation. Data from this aquatic network show that most virus parameters, such as abundance or frequency of visibly infected cells, were positively linked to bacterial abundance and production, but also to organic nitrogen or some phosphorus species. We calculated that between 13.2% and 46.1% of the bacterial standing stocks would be subjected to virus‐mediated mortality. Estimates of bacteriophage production revealed that from 10 × 109 up to 98 × 109 phages were produced per litre and day. Bacteria and viruses in the studied tropical freshwater system appear to be linked to various environmental conditions and may affect processes at the ecosystem scale.
Free Shiga toxin bacteriophages isolated from sewage showed diversity although the stx genes appeared conserved
Authors: Muniesa M. , Serra‐Moreno R. , Jofre J.
Published: June 2004

Phages carrying the stx2 gene were detected in a range of sewage samples using a plaque hybridization‐based method. After detection, phages were isolated and propagated with a laboratory strain of Escherichia coli as host for characterization purposes. Although it was not possible to conduct propagation or transduction experiments on most of the phages, 11 reached a sufficiently high titre for studies of host infectivity, electron microscopy and sequencing of the stx2 flanking regions to be performed. These phages showed a wide range of host infectivity and morphology. The genetic structure of the 5′stx flanking region appeared conserved whereas the 3′ region differed from that of previously described phages. This is the first description of infectious stx‐phages isolated as free particles in the environment, and as such constitutes a new contribution to the study of the ecology of these phages.
Adaptation of sympatric Achromatium spp. to different redox conditions as a mechanism for coexistence of functionally similar sulphur bacteria
Authors: Gray Neil D. , Comaskey Daria , Miskin Ian P. , Pickup Roger W. , Suzuki Keiko , Head Ian M.
Published: June 2004

Changes in the abundance of sympatric Achromatium spp. in response to the artificial manipulation of redox conditions in sediment microcosms was determined by fluorescence in situ hybridization (FISH). Adaptation to different redox conditions was shown to be one mechanism that supported the coexistence of functionally similar Achromatium spp. In sediment microcosms, in which the overlying water was oxygenated, Achromatium community size and composition remained unchanged over time. However, imposition of anoxic conditions induced changes in community structure. Anoxia caused a reduction in the relative abundance of Achromatium sp. RY8 (72 ± 4% to 49 ± 2%) and an increase in Achromatium sp. RY5 (19 ± 5% to 32 ± 3%) and a newly identified Achromatium sp., RYKS (14 ± 4% to 27 ± 2%). In anoxic microcosms supplemented with a single addition of nitrate at different initial concentrations the relative decline in Achromatium sp. RY8 was dependent on the initial nitrate concentration. In these experiments nitrate was rapidly removed. In contrast, when high levels of nitrate were maintained by periodic replacement of the overlying water with nitrate supplemented anoxic water, the composition of the Achromatium community remained stable over time. This suggested that all of the coexisting Achromatium spp. are obligate or facultative anaerobes, but, Achromatium sp. RY8 was more sensitive to sediment redox conditions than the other Achromatium species. Given the heterogeneous nature of sedimentary environments, redox‐related niche differentiation may promote coexistence of sympatric Achromatium spp.
Identification and phylogenetic sorting of bacterial lineages with universally conserved genes and proteins
Authors: Santos Scott R. , Ochman Howard
Published: June 2004

Molecular characterizations of bacteria often employ ribosomal DNA (rDNA) to establish the identity and relationships among organisms, but the use of rRNA sequences can be problematic as the result of alignment ambiguities caused by indels, the lack of informative characters, and varying functional constraints over the molecule. Although protein‐coding regions have been used as an alternative to rRNA, there is neither consensus among the genes examined nor ways to rapidly obtain sequence information for such genes from uncharacterized bacterial species. To standardize the set of protein‐coding loci assayed in bacterial genomes, we examined over 100 widely distributed genes to identify sets of universal primers for use in the PCR amplification of protein coding regions that are common to virtually all bacteria. From this set, we developed primer sets that each target of 10 genes spanning an array of genomic locations and functional categories. Although many of the primers contain sequence degeneracies that aid in targeting genes across diverse taxa, most are adequate for direct sequencing of amplification products, thereby eliminating intermediate cloning before sequence determination. We foresee the analysis of these protein‐coding regions as being complementary to ribosomal DNA for answering questions pertaining to bacterial identification, classification, phylogenetics and evolution.
Design and application of two oligonucleotide probes for the identification of Geodermatophilaceae strains using fluorescence in situ hybridization (FISH)
Authors: Urzì Clara , La Cono Violetta , Stackebrandt Erko
Published: June 2004

Bacteria of the family of Geodermatophilaceae are actively involved in the decay processes [Urzì, C. and Realini, M. (1998) Int Biodeterior Biodegrad 42: 45–54; Urzì, C., Salamone, P., Schumann, P., and Stackebrandt, E. (2000) Int J Syst Evol Microbiol 50: 529–536] of stone monuments. Characterization of isolates includes phenotypic, chemotaxonomic and genetic analysis often requiring long‐term procedures. The use of specific probes for members of Geodermatophilaceae family could be useful for the easy detection of those strains colonizing rock surfaces and involved in the biodeterioration. Two 16S rRNA‐targeted oligonucleotide probes were designed for the specific detection of members of the family Geodermatophilaceae using fluorescence in situ hybridization (FISH); one probe specific for members of the two genera Geodermatophilus/Blastococcus and the second for members of the genus Modestobacter.
Political Influence and Coexistence of a Uniform Accounting System and Accounting Standards: Recent Developments in China
Authors: Zezhong Xiao Jason , Weetman Pauline , Sun Manli
Published: June 2004

This article investigates the role of political influence, as well as accounting tradition and the equity market, in China's recent changes in accounting regulation. We find that the Chinese government, in part self‐motivated and in part under external pressure, has been active in developing accounting standards in harmony with international accounting standards. However, it has retained a uniform accounting system in the Enterprise Accounting System issued in 2000 to accommodate the special circumstances of a transforming government, strong state‐ownership, a weak accounting profession, a weak and imperfect equity market, and the inertial effect of accounting tradition and cultural factors. This article also contributes to existing models of accounting system classification by illustrating the need for considering political influence as a factor that affects the rate of transition towards full implementation of international accounting standards.
Customer Profitability Analysis Reports for Resource Allocation: The Role of Complex Marketing Environments
Authors: Cardinaels Eddy , Roodhooft Filip , Warlop Luk
Published: June 2004

Most decision making research in management accounting remains focused on cost information in a production context. Little is known on the relevance of customer profifitability analysis (CuPA) reports, which more accurately reflect revenue and marketing support variations acrosscustomers, for marketing decisions. This study uses an experimental design to examine the impact of such reports on resource allocation decisions (that affect the firm's profits) in marketing environments varying in complexity. The main result of the experiment suggests that the value of CuPA reports depends on the complexity of the marketing setting. Only in a highly complex marketing setting do they enhance resource allocation decisions and resultant firm profitability. Conversely, in the simple marketing environment, decision makers can combine their traditional volume‐based cost data with other available types of feedback to perform as well as under a more accurate CuPA report. These findings on complexity contrast with those of a prior study in a production context (Gupta and King, 1997). It is argued that improvements in the current research design, in the form of regularly updated profitability reports and concerning accuracy, increase the relevance of CuPA reports in a complex marketing setting.
Gaps in Guidelines on Audit Committees
Authors: Walker R. G.
Published: June 2004

Since the 1940s, advocacy of the establishment of audit committees was undertaken by regulatory agencies, and subsequently by the accounting profession, and committees representing combinations of interest groups. Over time, this advocacy literature has reflected changing views about the key responsibilities of audit committees. Initially, audit committees were primarily concerned with negotiations with (or responding to) auditors, and reviewing financial statements prior to publication. Since the 1970s, formal guidelines or requirements have suggested additional responsibilities that involve oversight of the internal management of corporations. There is a pattern of renewed enthusiasm for enhanced corporate governance and for a stronger role for audit committees following spates of corporate crashes or disasters. Nevertheless, some of the lessons from those events continue to be ignored, so that arguably there are gaps in contemporary guidelines on audit committees. These gaps concern the need for audit committees to review the structure and design of delegations, and the adequacy of financial and operational information being provided to senior management and boards (particularly concerning subsidiaries and associated entities). These gaps are also reflected in the charters of the audit committees of Australia's top 200 listed entities. However, in some respects, Australian practice has gone beyond the recommendations embodied in recent guidelines. Drawing from literature and practice, this article proposes a model charter which, if adopted, may contribute to improvements in the effectiveness of audit committees.