bluuebunny/crossref_metadata_2025_split huggingface dataset:
Helicobacter pylori is a fragile bacteria when stored at low and ultra‐low temperatures
Authors: OHKUSA TOSHIFUMI , Miwa HIROTO , ENDO SHU , OKAYASU ISAO , SATO NOBUHIRO 
Published: January 2004

AbstractBackground and Aim:  Usually, bacteria are cryopreserved for short‐term storage at low and ultra‐low temperatures. There are no reports as to whether Helicobacter pylori is a fragile bacteria when stored at low and ultra‐low temperatures as compared with other intestinal bacteria. A study was done on seven H. pylori strains and other intestinal bacteria to compare different temperatures for storage of organisms in saline solution.Methods:  Seven H. pylori strains, specifically American Type Culture Collection (ATCC) strains 43504 and TN2GF4, and five strains isolated from the present patients were grown on a modified Skirrow's agar for H. pylori. Escherichia coli and Bacteroides distasonis, both representing isolates from the present patients, were grown on trypticase soy blood agar for E. coli, and EG agar for B. distasonis. Culture was for 4–5 days under microaerobic, aerobic and anaerobic conditions at 37°C. Cells were harvested by scraping growth from the solid medium and into sterile saline. The cells were adjusted to concentrations of 109 viable cells/mL in saline and preserved at 4°C, −20°C, or −80°C for 3 weeks before reculture under microaerobic, aerobic and anaerobic conditions at 37°C for 7 days. After incubation, morphologically distinct colonies were counted, isolated, and identified by standard bacteriologic techniques. The H. pylori were morphologically analyzed by electronic microscopy before and after preservation. Mongolian gerbils were inoculated with the cryopreserved H. pylori to evaluate the bacterial infectivity.Results:  Six  of  the  seven  H. pylori strains  failed  to  culture  after  being  preserved  at  4°C,  −20°C, or −80°C. Only ATCC 43504 could be cultured after freezing at −80°C. The number of H. pylori ATCC 43504 before preservation was 9.0 ± 0.5 (log10 no. organisms/mL) and decreased to 5.7 ± 0.6 after preservation. Morphologically, all H. pylori except ATCC 43504 strains transformed from a bacillary to a coccoid form after preservation. In addition, none of the H. pylori strains could infect Mongolian gerbils after preservation. Escherichia coli and B. distasonis were recovered. Titers before and after 4°C, −20°C, and −80°C, respectively, were 9.1 ± 0.2, 8.9 ± 0.5, 8.6 ± 0.3, and 8.7 ± 0.3 for E. coli and 9.1 ± 0.4, 8.7 ± 0.6, 8.6 ± 0.5, and 8.8 ± 0.3 for B. distasonis.Conclusions:  Helicobacter pylori is a fragile bacteria for storage at low and ultra‐low temperatures in comparison with other intestinal bacteria.
Increased hepatic and renal expressions of multidrug resistance‐associated protein 3 in Eisai hyperbilirubinuria rats
Authors: KURODA MAKOTO , KOBAYASHI YOSHINAO , TANAKA YUJI , ITANI TOSHIO , MIFUJI RUMI , ARAKI JUN , KAITO MASAHIKO , ADACHI YUKIHIKO 
Published: January 2004

AbstractBackground and Aim:  Eisai hyperbilirubinuria rats (EHBR) are animal models of Dubin–Johnson syndrome, which suffer from jaundice due to impaired biliary excretion of bilirubin glucuronides. In EHBR, deficiency of multidrug resistance‐associated protein 2 (mrp2) causes defective biliary excretion of numerous organic anions. However, little is known about the expression of other organic anion transporters in this mrp2‐deficient model. The aim of the present study was to investigate adaptive expressions of mrp1, mrp3, mrp6, organic anion transporting polypeptide 1 (oatp1) and oatp2 in liver and kidney of EHBR.Methods:  For the present study, EHBR (n = 5) were used. Hepatic and renal mRNA expression of the aforementioned transporters was determined by constructed semiquantitative reverse transcription polymerase chain reaction assay. Their protein expression was determined by western blotting. Localization of hepatic and renal mrp3 was confirmed by immunohistochemistry. Sprague–Dawley (SD) rats (n = 5) were used as normal controls.Results:  Deficiency of mrp2 protein was confirmed in EHBR. Hepatic and renal expression of mrp3 mRNA was 53.6% (P < 0.001) and 82.9% (P < 0.001), and its protein expression was 298.9% (P < 0.001) and 245.0% (P = 0.001) higher in EHBR than in SD rats, respectively. Hepatic and renal expression of mrp1 and mrp6 mRNA was not significantly different between EHBR and SD rats. The mrp1 and mrp6 proteins were expressed in very low amounts in the liver and kidney of both EHBR and SD rats. In contrast to mrp3, hepatic expression of oatp1 and oatp2 mRNA was 33.9% (P = 0. 001) and 38.6% (P < 0.001), and their protein expression was 57.4% (P < 0.05) and 51.0% (P < 0.01) lower in EHBR than in SD rats, respectively. Hepatic and renal mrp3 protein was localized at the basolateral membrane.Conclusions:  Mrp3 plays an important role in the compensation of mrp2 deficiency in liver and kidney of EHBR. Hepatic expressions of mrp3, oatp1 and oatp2 changed adaptively in this animal model. This is a compensatory mechanism for reducing injury to hepatocytes from cytotoxic materials that increase in mrp2 deficiency.
Measuring floristic homogenization by non‐native plants in North America
Authors: McKinney Michael L. 
Published: January 2004

ABSTRACTAim  To determine if non‐native plant species are homogenizing species composition among widely dispersed plant communities.Location  Twenty localities in North America.Methods  Species lists among localities were compared to measure the influence of non‐native species richness at each locality on the Jaccard Index (JI) of similarity between localities.Results  After removing the effects of distance, because shared native species decreased with distance, three (nonexclusive) lines of evidence indicate that non‐native species promote homogenization. First, pairs of sites with a high combined total of non‐native species tend to have higher similarity than those with a low total of non‐natives. Second, for a given distance, more non‐native than native species tended to be shared among localities. Third, whereas most of the site comparisons with high total non‐native richness have a non‐native/native JI ratio greater than 1 (often much greater), only half of the comparisons with low total non‐native richness have a ratio greater than one.Main conclusions  These findings provide quantitative support for the widely held, but rarely tested, notion that non‐native species tend to homogenize biological communities because they are more commonly shared among communities. Such testing is important as non‐native species could theoretically have no impact or even reduce homogenization among communities, if non‐native colonizers consist of different species pools.
Local and regional abundance of exotic plant species on Mediterranean islands: are species traits important?
Authors: Lloret Francisco , Médail Fréderic , Brundu Giuseppe , Hulme Philip E. 
Published: January 2004

ABSTRACTAim  We assess the importance of three relevant and readily obtainable life‐history traits (dispersal syndrome, stem height and growth form) and biogeographical origin (European vs. non‐European) on the local and regional abundance of over 400 exotic plant species across eight Mediterranean islands.Location  The Mediterranean islands of Lesbos, Rhodes, Crete, Malta, Corsica, Sardinia, Majorca and Minorca.Methods  We adopt two abundance criteria for each exotic species: the proportion of islands in which the species occurs (regional abundance), and a qualitative estimate of species abundance within each of five islands (local abundance). Subsequently, we assess the relationship between local and regional abundance, as well as the role of key life‐history traits on both regional and local abundance. These analyses were undertaken separately for the European exotics and the non‐European exotics.Results  Only 10.9% of the species occur on more than four islands, and only four species are present on all eight islands. Both local and regional abundances were higher for the non‐European than the European species. Local and regional abundances were positively correlated, particularly for exotics with non‐European origins. Wind‐dispersed species tended to have higher regional abundance than species dispersed by other means but this trend only occurred for local abundance on two islands — Corsica and Majorca. Neither a species’ growth form nor its stem height explained trends in regional or local abundance.Conclusions  Although wind‐dispersed exotics are more widespread in the Mediterranean, plant life‐history traits appear to play a lesser role in invasion success than area of biogeographical origin. In general, exotic species of non‐European origin were more abundant at both local and regional scales. Invasion patterns should be interpreted at both local and regional scales, but the stochastic nature of biological invasions may limit deterministic interpretations of invasion patterns, especially if islands are studied in isolation.
From sampling stations to archipelagos: investigating aspects of the assemblage of insular biota
Authors: Sfenthourakis Spyros , Giokas Sinos , Tzanatos Evangelos 
Published: January 2004

ABSTRACTAim  To investigate the formation of nestedness and species co‐occurrence patterns at the local (sampling station), the intermediate (island group), and the archipelago scale.Location  The study used data on the distribution of terrestrial isopods on 20 islands of the central Aegean (Greece). These islands are assigned to two distinct subgroups (Kyklades and Eastern islands).Methods  The Nestedness Temperature Calculator was used to obtain nestedness values and maximally nested matrices, the EcoSim7 software and a modified version of Sanderson (2000) method were used for the analysis of species co‐occurrences. Idiosyncratic temperatures of species and the order of species placement in the maximally nested matrices were used for further comparisons among spatial scales. The relationships of nestedness values with beta‐diversity, habitat diversity and a number of ecological factors recorded for each sampling station were also investigated.Results  Significant nestedness was found at all spatial scales. Levels of nestedness were not related to beta‐diversity or habitat diversity. Nestedness values were similar among spatial scales, but they were affected by matrix size. The species that contributed most to the nested patterns within single islands were not the same as those that produce nestedness at the archipelago scale. There was significant variation in the frequency of species occurrence among islands and among spatial scales. There was no direct effect of ecological factors on the shaping of patterns of nestedness within individual islands, but habitat heterogeneity was crucial for the existence of such patterns. Positive associations among species prevailed at all scales when species per station were considered, while negative associations prevailed in the species per island matrices. All associations resulted from the habitat structure of sampling stations and from particularities of geographical distributions.Conclusions  There was no clear‐cut distinction between nestedness patterns among spatial scales, even though different species, and partially different factors, contributed to the formation of these patterns in each case. There was a core of species that contributed to the formation of nested patterns at all spatial scales, while the patterns of species associations suggested that biotic interactions are not an important causal factor. The results of this study suggest that locally rare species cannot be widespread at a higher spatial scale, while locally common species can have a restricted distribution.
Geographic gradients of deforestation and mammalian communities in a fragmented, temperate rain forest landscape
Authors: Lomolino Mark V. , Perault David R. 
Published: January 2004

ABSTRACTAim  We studied the temporal and spatial patterns in deforestation and community structure of mammals in a fragmented old‐growth, temperate rain forest to test the hypothesis that anthropogenic habitat conversion advances in a nonrandom manner across native landscapes, and that its effects on ecological communities are both persistent and predictable.Location  The location is the Hood Canal district of Olympic National Forest, Washington, USA.Results  Deforestation followed the apparently general pattern observed for deforestation of tropical rain forests and other native landscapes, advancing first along low and relatively level valleys, then to areas at higher elevations and along steeper slopes, and eventually to sites more distant from those of initial land conversion and transportation centres. Mammal surveys within this area indicated that this nonrandom advance of deforestation has created relatively steep geographical and topographic gradients in both local and landscape‐level factors and, ultimately, in the structure of mammalian communities.Conclusion  The close and likely causal relationship between anthropogenic habitat loss and the ecological dynamics of mammalian communities and dependent species (e.g. spotted owls) indicates that our abilities to understand and eventually reduce the current extinction crisis may rely heavily on our understanding of, and abilities to modify, the manner in which we expand across and transform native landscapes.
Latitudinal gradient in species richness of the New World Triatominae (Reduviidae)
Authors: Rodriguero Marcela S. , Gorla David E. 
Published: January 2004

ABSTRACTAim To quantify the latitudinal gradient in species richness in the New World Triatominae and to explore the species‐energy and area hypotheses as possible causes.Location The gradient was studied for North and South America, between 43° N and 32° S.Methods A database was constructed containing the geographical distribution of the 118 New World Triatominae species based on data extracted from several published sources. Species richness was recorded as the number of species present within 5° latitudinal bands. We used univariate and multivariate models to analyse the relationship between area within each latitudinal belt, land surface temperature, and potential evapotranspiration as explanatory variables, and species richness. All variables were georeferenced and data were extracted using a GIS.Results Species richness of Triatominae increases significantly from the poles towards the Equator, peaking over the 5°−10 ° S latitudinal band. It increases according to a linear model, both north and south of the Equator, although a quadratic model fits better to southern hemisphere data. Richness correlates with habitable geographical area, when it is analysed through a nonlinear multiple regression factoring out latitude, only in the southern hemisphere. Regarding the species‐energy hypothesis, a multiple regression analysis controlling the effect of latitude shows a significant relationship between temperature and species richness. This effect is more pronounced in the southern hemisphere. Species richness shows a strong longitudinal trend south of the Equator (increasing to the east), but not north of the Equator. This differential pattern is reflected in significant interactions between longitude and both latitude and temperature in models of the species richness of the New World Triatominae.Main conclusions To our knowledge, this is the first time that a latitudinal gradient in species richness has been shown and analysed for obligate haematophagous organisms, and it shows that the species–energy hypothesis can account for this phenomenon. This relationship is stronger in the southern hemisphere.
Renal Dopamine and Salt Sensitivity of Blood Pressure in IgA Nephropathy
Authors: Pestana Manuel , Santos Joana , Santos Alejandro , Coroas Andreia , Correia Flora , Serrão Paula , Valbuena Carmen , Soares-da-Silva Patrício 
Published: January 2004

<i>Background:</i> Patients with chronic glomerulonephritis exhibit salt-sensitive (SS) hypertension. In the early stage, however, the exact characteristics are still unclear. A decrease in renal dopamine production under basal conditions or after a sodium load has been reported in a subset of patients with SS primary hypertension. <i>Aims:</i> The present study examined 17 untreated IgA-N patients with near-normal renal function, to determine whether salt sensitivity appears before hypertension and whether this sensitivity is related to renal dopamine production. <i>Methods:</i> Daily urinary excretion of dopamine, the amine precursor – L-DOPA, and metabolites was monitored in conditions of basal sodium ingestion, followed by three consecutive 5-day periods of 100, 20 and 350 mmol/day sodium intake. The sodium sensitivity index (SSI) was evaluated in each patient. In addition, the patients were considered SS when showing an increase ≧5 mm Hg in 24-hour mean BP when they changed from a 20- to a 350-mmol/day sodium diet. <i>Results:</i> Urinary dopamine output was lower in SS than in salt-resistant patients throughout the study (p < 0.001). This was accompanied by lower creatinine clearance values and higher urinary protein excretion in SS IgA-N patients. A strong negative relationship was observed in these 17 IgA-N patients between the SSI and the daily urinary excretion of dopamine in conditions of both 20 mmol/day sodium intake (r<sup>2</sup> = 0.592; p = 0.0003) and 350 mmol/day sodium diet (r<sup>2</sup> = 0.352; p = 0.01). However, urinary dopamine output varied appropriately throughout the study in SS patients, in agreement with changes in sodium intake. <i>Conclusion:</i> We conclude that in IgA-N patients, a rightward shift in the ‘pressure natriuresis’ can appear before hypertension and is related with a reduced renal production of dopamine. It is suggested that decreased renal dopamine synthesis in SS IgA-N patients results from acquired tubulointerstitial injury. In contrast to what has been found in SS primary hypertension, renal dopamine may behave appropriately in SS IgA-N patients, as a compensatory hormone.
Thrombolysis for Ischemic Stroke in Patients with Old Microbleeds on Pretreatment MRI
Authors: Derex Laurent , Nighoghossian Norbert , Hermier Marc , Adeleine Patrice , Philippeau Frédéric , Honnorat Jérôme , Yilmaz Hasan , Dardel Pascal , Froment Jean-Claude , Trouillas Paul 
Published: January 2004

<i>Background:</i> Old asymptomatic microbleeds (MBs) visualized on T<sub>2</sub>-weighted MRI are indicative of microangiopathy. They may be a marker of increased risk of intracerebral hemorrhage (ICH) following thrombolysis. However, data regarding this potential risk are limited. <i>Methods:</i> A retrospective analysis of pretreatment T<sub>2</sub>-weighted MRI was performed in consecutive stroke patients who received intravenous tissue plasminogen activator (tPA). We aimed to assess the impact of MBs on the risk of cerebral bleeding. The frequency and location of MBs were assessed and compared with the location of ICH after thrombolysis. <i>Results:</i> Forty-four patients were studied. MBs were present on pretreatment MRI in 8 cases (18.2%). At day 1, symptomatic ICH occurred in none of 8 patients with MBs versus 1 of 36 patients without (NS). At day 1, ICH occurred in 3 of 8 patients with MBs versus 10 of 36 patients without (NS). At day 7, symptomatic ICH occurred in 1 of 8 patients with MBs versus 2 of 36 patients without (NS). At day 7, ICH occurred in 5 of 8 patients with MBs versus 12 of 36 patients without (NS). No ICH occurred at the site of an MB. ICH occurred within the ischemic area in all patients who bled. <i>Conclusions:</i> Our study suggests that stroke patients with a small number of MBs on pretreatment MRI could be treated safely with thrombolysis. Larger prospective studies are needed to address the predictive value of detection of MBs with regard to the risk of tPA-induced ICH.
JNK activation is a mediator of arsenic trioxide-induced apoptosis in acute promyelocytic leukemia cells
Authors: Davison Kelly , Mann Koren K. , Waxman Samuel , Miller Wilson H. 
Published: January 2004

Abstract
Arsenic trioxide induces c-jun N-terminal kinase (JNK) activation and apoptosis in acute promyelocytic leukemia (APL), where it has major clinical activity, but whether JNK is necessary to induce apoptosis is unknown. To clarify this necessity, we established 2 arsenic trioxide (As2O3)-resistant subclones of the APL cell line, NB4. Both resistant lines showed little activation of JNK1 following treatment with As2O3, even at doses sufficient to elicit robust activation in NB4 cells. One mechanism of resistance in these cells is up-regulated glutathione (GSH) content, and GSH depletion by l-buthionine-[S,R]-sulfoximine (BSO) restores JNK activation and As2O3 sensitivity. This correlation between JNK activation and apoptosis led us to test whether inhibition of JNK would protect cells from As2O3-induced apoptosis. SEK1-/- mouse embryo fibroblasts (MEFs) showed diminished JNK activation following As2O3 treatment and were protected from As2O3-induced but not doxorubicin-induced apoptosis. Furthermore, treatment of arsenic trioxide-sensitive APL cells with the JNK inhibitor, dicumarol, significantly increased growth and survival in response to As2O3 but did not protect cells from doxorubicin. Together, these data support an essential role for JNK signaling in the induction of growth inhibition and apoptosis by As2O3 and suggest that activating JNK may provide a therapeutic advantage in the treatment of cancers that do not respond to arsenic alone. (Blood. 2004;103:3496-3502)
A pilot study of alemtuzumab (anti-CD52 monoclonal antibody) therapy for patients with relapsed or chemotherapy-refractory peripheral T-cell lymphomas
Authors: Enblad Gunilla , Hagberg Hans , Erlanson Martin , Lundin Jeanette , MacDonald Anja Porwit , Repp Roland , Schetelig Johannes , Seipelt Gernot , Österborg Anders 
Published: January 2004

Abstract
Patients with peripheral T-cell lymphomas (PTLs) have an extremely poor prognosis when relapsed or refractory to conventional chemotherapy. We have studied alemtuzumab, a humanized anti-CD52 monoclonal antibody, as therapy for patients with heavily pretreated and refractory PTL. Fourteen patients entered the study. All had clinical stage III or IV disease. Patients received a rapidly escalating dosage of alemtuzumab during the first week and, thereafter, 30 mg intravenously 3 times per week for a maximum of 12 weeks. Trimethoprim/sulphamethoxazole and valaciclovir prophylaxis was given to all patients. The overall response rate was 36% (5 of 14). Three patients achieved a complete remission (CR) and 2 patients a partial remission. The durations of the CRs were 2, 6, and 12 months, respectively. Toxicity included cytomegalovirus reactivation in 6 patients, which was successfully treated with ganciclovir or foscarnet; pulmonary aspergillosis in 2 patients; and pancytopenia in 4 patients. Epstein-Barr virus–related hemophagocytosis was observed in 2 patients. Five patients died of causes related to the treatment, in combination with advanced disease. We conclude that alemtuzumab is active when used in patients with advanced, heavily pretreated PTL, although it is associated with significant hematologic toxicity and infectious complications. Further studies are warranted in younger patients and patients with less advanced disease. (Blood. 2004;103: 2920-2924)