bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement of vascular function by chronic administration of a cyclo‐oxygenase inhibitor in cholesterol‐fed rabbits
Authors: Srisawat Supath , Phivthong‐ngam Laddawal , Unchern Supeenun , Chantharaksri Udom , Govitrapong Piyarat , Sanvarinda Yupin 
Published: July 2003

Summary1. Atherosclerotic cardio‐ and cerebrovascular disease is a leading cause of mortality in Western countries. Aspirin‐like drugs are widely used to prevent and treat these occlusive cardio‐ and cerebrovascular diseases. The beneficial effects of these drugs have been largely attributed to inhibition of platelet cyclo‐oxygenase activity and thromboxane (TX) A2 production. We investigated the effect of an aspirin‐like drug, namely indomethacin, on endothelial function, plaque and platelet aggregation and the formation of vasoactive substances during the development of atherosclerosis in cholesterol‐fed rabbits.2. Rabbits were fed 1% cholesterol (n = 8), 1% cholesterol plus 25 mg/day indomethacin (n = 8) or normal rabbit chow (control group; n = 8) for 12 weeks. Urinary excretion rates of 2,3‐dinor‐TXB2, 6‐keto‐prostaglandin (PG) F1α, 8‐iso‐PGF2α and nitrate were analysed at the beginning of dietary intervention and at 4 weekly intervals thereafter. At the end of the study period, platelet aggregation, aortic plaque formation and endothelium‐dependent and ‐independent vascular functions of isolated aortic rings ex vivo were assessed.3. Compared with control, in the cholesterol‐fed group, urinary 2,3‐dinor‐TXB2, 6‐keto‐PGF1α and 8‐iso‐PGF2α excretion and platelet aggregation were significantly increased (P < 0.05), but urinary excretion of nitrate was decreased (P < 0.05). Treatment with indomethacin significantly reduced platelet aggregation, urinary 2,3‐dinor‐TXB2, 6‐keto‐PGF1α and 8‐iso‐PGF2α excretion (P < 0.05 vs the cholesterol‐fed group) and attenuated the reduction in urinary nitrate excretion.4. Cholesterol feeding progressively increased aortic intimal thickening and impaired endothelium‐dependent vasodilator function (P < 0.05 vs control), whereas indomethacin partially prevented aortic plaque formation and restored endothelium‐dependent vasodilation (P < 0.05 vs the cholesterol‐fed group).5. The present study demonstrates that indomethacin reduces the progression of atherosclerotic lesions and improves endothelium‐mediated vascular responses ex vivo in cholesterol‐fed rabbits. The beneficial effects of indomethacin may be due to its ability to prevent the elevation of platelet aggregation, TXA2 (measured as urinary 2,3‐dinor‐TXB2 excretion) and 8‐iso‐PGF2α formation and to retard the decrease in endogenous nitric oxide synthesis (assessed as urinary excretion of nitrate). Despite indomethacin treatment leading to the suppression of prostacyclin biosynthesis (assessed as urinary 6‐keto‐PGF1α excretion), according to our data, indomethacin appears to preserve endothelial function.
Function of renal angiotensin AT2 receptors is not enhanced in Lyon hypertensive rats
Authors: Liu Kiao Ling , Lo Ming , Benzoni Daniel , Sassard Jean 
Published: July 2003

Summary1. Because we previously observed that angiotensin AT2 receptor stimulation decreased pressure–natriuresis, in the present study we examined the possible involvement of these receptors in altered sodium excretion shown by Lyon hypertensive (LH) rats.2. In 9‐week‐old male anaesthetized LH rats and normotensive (LL) controls pretreated with an angiotensin‐converting enzyme inhibitor (quinapril; 10 mg/kg) and an AT1 receptor antagonist (losartan; 10 mg/kg), angiotensin (Ang) II was infused (30 ng/kg per min) to stimulate AT2 receptors. In other groups of rats, an AT2 receptor antagonist (PD123319; 50 µg/kg per min) was added before AngII infusion.3. During AT2 receptor stimulation, LH differed from LL rats by significantly reduced renal blood flow (RBF), glomerular filtration rate and pressure diuresis and natriuresis. The addition of PD123319 did not change total RBF, whereas it did increase pressure diuresis and natriuresis in both strains. However, the effects of PD123319 were less marked in LH rats than in LL rats.4. These findings confirm that, under the present experimental conditions, AT2 receptors are antinatriuretic and are not of greater functional importance in hypertensive animals of the Lyon strain.
Changes in autonomic activity and baroreflex sensitivity with the hypertension process and age in rats
Authors: Nagai Ryuji , Nagata Shinya , Fukuya Fumiyo , Higaki Jitsuo , Rakugi Hiromi , Ogihara Toshio 
Published: July 2003

Summary1. Autonomic activity and baroreflex sensitivity (BRS) were compared in age‐matched conscious groups of Wistar Kyoto (WKY) rats, spontaneously hypertensive rats (SHR) and stroke‐prone spontaneously hypertensive rats (SHRSP).2. Male WKY rats, SHR and SHRSP aged 4–30 weeks were used. Autonomic activity and BRS were estimated by power spectral and cross‐spectral analysis of systolic blood pressure (SBP) and SBP–SBP (SS) interval fluctuations, respectively.3. The time‐course of heart rate (HR), SBP, the amplitude of the low‐frequency component of SBP fluctuation (SBP‐LF; prazosin‐sensitive index) and the amplitude of the high‐frequency component of the SS interval fluctuation (SS‐HF; atropine‐sensitive index) consisted of two periods. In the first period (up to 10 or 15 weeks of age), BP, SBP‐LF and SS‐HF increased with age. The order of SBP‐LF was SHRSP > SHR > WKY rats throughout this period. During the second period, BP was sustained at certain levels in all strains, but changes in SBP‐LF and SS‐HF with age were different among strains. In particular, in SHRSP, SBP‐LF markedly decreased with age after 10 weeks. Baroreflex sensitivity in WKY rats increased gradually with age, whereas the BRS in SHR and SHRSP decreased before 6 weeks of age and remained lower than that in WKY rats.4. In conclusion, the present study shows that both prazosin‐sensitive and atropine‐sensitive indices are associated with the elevation of BP in all strains studied. However, hypertension after 15 weeks of age in SHRSP is sustained despite a paradoxical reduction in sympathetic activity with an abnormal control of BRS. Therefore, the contribution of autonomic activity to hypertension may be discussed separately as a developmental period and a sustained period.
Role of mitochondrial KATP channels and protein kinase C in ischaemic preconditioning
Authors: Uchiyama Yuka , Otani Hajime , Wakeno Mayu , Okada Takayuki , Uchiyama Takamichi , Sumida Tomohiko , Kido Masakuni , Imamura Hiroji , Nakao Shinichi , Shingu Koh 
Published: July 2003

Summary1. Activation of mitochondrial KATP (mitoKATP) channels and protein kinase C (PKC) has been implicated in cardioprotective mechanisms of ischaemic preconditioning (IPC). However, the exact role of these events in early IPC remains unclear.2. Isolated and perfused rat hearts underwent IPC with three cycles of 5 min ischaemia and 5 min reperfusion. The heart was subjected to 30 min global ischaemia followed by 120 min reperfusion. Flavoprotein oxidation was monitored to assess mitoKATP channel activity. Cardioprotection was evaluated by recovery of isovolumic left ventricular (LV) function and infarct size.3. Diazoxide (50 mgr;mol/L) increased flavoprotein oxidation and conferred cardioprotection in a manner sensitive to the selective mitoKATP channel blocker 5‐hydroxydecanoate (5‐HD; 0.5 mmol/L).4. Pretreatment with 0.5 mmol/L 5‐HD abrogated IPC‐induced flavoprotein oxidation and cardioprotection, whereas late treatment with 5‐HD after IPC required a higher dose (2 mmol/L) to abolish flavoprotein oxidation and cardioprotection afforded by IPC.5. Pretreatment with the PKC inhibitors Ro318425 (1 µmol/L) and chelerythrine (5 µmol/L) abolished IPC‐induced flavoprotein oxidation and cardioprotection, whereas late treatment with Ro318425 required a higher dose (4 µmol/L) to abolish flavoprotein oxidation and cardioprotection.6. In conclusion, these results suggest that activation of mitoKATP channels is the trigger and the mediator of IPC and that PKC plays a crucial role in both phases of mitoKATP channel activation, although mitoKATP channels and PKC may be more activated during the mediator phase.
Role of the diurnal variation of urinary pH and urinary calcium in urolithiasis: A study in outpatients
Authors: Murayama Tetsuo , Sakai Naoki , Yamada Tetsuo , Takano Tetsuzou 
Published: July 2003

Abstract Background: We previously reported that the urinary excretion of calcium and the diurnal variation of urinary pH were important for stone formation in hospitalized inpatients with hospital standard diet. Because almost all urinary stones are formed in outpatients with ambulatory free diet, it is essential to investigate these factors in outpatients.Methods: We examined the urinary excretion of calcium, oxalate, uric acid, phosphate and magnesium in 96 male outpatients and 142 male inpatients. We also studied the relationship between the stone composition and the diurnal variation of urinary pH in 32 male outpatients (five uric acid stones (UA), 13 pure calcium oxalate stones (CaOX) and 14 mixed calcium oxalate and calcium phosphate stones (CaOX–CaP)) and 53 male inpatients (nine UA, 15 CaOX and 29 CaOX–CaP).Results: There was a significant difference in the urinary excretion of calcium among outpatients with UA, CaOX and CaOX–CaP (133 ± 96 vs 219 ± 97 vs 268 ± 102 mg per day, P < 0.05). In outpatients with UA, urinary pH was constantly low throughout the entire day. In contrast, outpatients with CaOX and those with CaOX–CaP had diurnal variation of urinary pH that was low in the early morning, followed by elevation in the daytime and was lowered in the night.The pHs in the early morning, afternoon and night were significantly higher in outpatients with CaOX–CaP than in those with CaOX.Conclusion: The diurnal variation of urinary pH and the urinary calcium are important for stone formation.
Comparison of Japanese General Rules of Prostatic Cancer and Gleason grading system
Authors: Fukagai Takashi , Namiki Thomas , Carlile Robert G. , Sugawara So , Morita Masashi , Shimada Makoto , Yoshida Hideki , Namiki Hideo 
Published: July 2003

Abstract Background: We compared the prognostic efficacy between the Japanese General Rules of Prostatic Cancer (JGRPC) and the Gleason grading system (GGS) by applying them to a single set of patients and assessing the survival outcome.Methods: One hundred and seventy‐six patients with previously untreated prostate cancer were studied. One experienced Japanese pathologist graded the slides with JGRPC. Another experienced American pathologist graded the same slides with the Gleason grading system. The JGRPC grades were correlated with the Gleason scores (GS) grouped into three (GS 2–4, 5–7 and 8–10) or four (GS 2–4, 5–6, 7 and 8–10) tiers.Results: The highest cancer death rates were seen in the higher grade groups in both systems. Comparison of JGRPC grade and three‐tiered grouping of the GS showed identical grades in 81 of 176 cases (46.0%). The overall kappa value of agreement was only 0.151. The 96 cases of JGRPC moderately differentiated carcinoma group contained two nearly equal‐sized groups by the Gleason grading system, those with GS 5–7 (47cases) and GS 8–10 (49 cases). There was a significant difference in survival rate between the GS 5–7 and GS 8–10 groups. No significant differences were noted in the reverse analysis of survival by JGRPC groups within patients with the same GS three‐tiered groups. Similar trends were seen when JGRPC was compared with the four‐tiered grouping of the GS.Conclusion: Both JGRPC and the Gleason grading system are useful in estimating the prognosis of prostate cancer, but only a mild correlation was found between the two systems. The Gleason grading system may provide more prognostic information than JGRPC in the moderately differentiated group.
Indications and Techniques for Endoscopic Mucosal Resection in the Lesions of A Colorectal Tumor
Authors: TAMURA SATORU , OHKAWAUCHI KOJI , YOKOYAMA YUICHI , ONISHI SABURO 
Published: July 2003

We evaluated the possibility of an extended application of endoscopic treatment for submucosal‐invading colorectal cancers, and describe the method of endoscopic mucosal resection (EMR) using a one channel colonoscope.A total of 328 submucosal‐invading cancers were examined from July 1985 to September 2002. The patterns of infiltrating growth into the submucosal layer were further divided into two groups: expanding growth, and infiltrating growth. Lymph node metastasis occurred in sm2 and extension cancer in more advanced stages. The lowest measurement of submucosal invading cancer with lymph node metastasis was 1250 µm. As for patterns of invasion, the frequencies of lymph node metastasis in the groups of expanding growth and infiltrating growth were 0% (0/87) and 14.5% (16/110), respectively, (P = 0.0002, Fisher's direct method). Results showed that endoscopic treatment is suitable for sm1 extension without vessel invasion, but there is a possibility that some sm2 extension cancers can be cured radically when the pattern of submucosal invasion shows expanding growth with a distinct border.
Quantification of dissimilatory (bi)sulphite reductase gene expression in Desulfobacterium autotrophicum using real‐time RT‐PCR
Authors: Neretin Lev N. , Schippers Axel , Pernthaler Annelie , Hamann Knut , Amann Rudolf , Jørgensen Bo Barker 
Published: July 2003

SummaryWe developed a real‐time RT‐PCR method for the quantification of dissimilatory (bi)sulphite reductase (DSR) mRNA in Desulfobacterium autotrophicum cells. The amount of DSR mRNA was determined relative to the amount of 16S rRNA at different growth conditions during transition from exponential to stationary phase: sulphate respiration with lactate, thiosulphate respiration with lactate, sulphate respiration with H2 and pyruvate fermentation. The dsr gene was expressed constitutively, although DSR mRNA content per‐cell varied under different growth conditions. The maximum DSR mRNA per‐cell content was 2.0 to 4.1‐fold higher during sulphate or thiosulphate respiration than during pyruvate fermentation. After transfer of a pyruvate‐fermenting culture into sulphate‐rich medium, upregulation of the DSR mRNA content was observed. Irrespective of the mode of metabolism the per‐cell DSR mRNA content changed significantly during growth (up to 310‐fold from the early to the late exponential phase during respiration with thiosulphate). The maximum DSR mRNA per‐cell contents correlated with cell‐specific sulphate reduction rates for all experiments. Environmental applications for the quantification of DSR mRNA are discussed.
Interspecific evolution: microbial symbiosis, endosymbiosis and gene transfer
Authors: Hoffmeister Meike , Martin William 
Published: July 2003

SummaryMicrobial symbioses are interesting in their own right and also serve as exemplary models to help biologists to understand two important symbioses in the evolutionary past of eukaryotic cells: the origins of chloroplasts and mitochondria. Most, if not all, microbial symbioses have a chemical basis: compounds produced by one partner are useful for the other. But symbioses can also entail the transfer of genes from one partner to the other, which in some cases cements two cells into a bipartite, co‐evolving unit. Here, we discuss some microbial symbioses in which progress is being made in uncovering the nature of symbiotic interactions: anaerobic methane‐oxidizing consortia, marine worms that possess endosymbionts instead of a digestive tract, amino acid‐producing endosymbionts of aphids, prokaryotic endosymbionts living within a prokaryotic host within mealybugs, endosymbionts of an insect vector of human disease and a photosynthetic sea slug that steals chloroplasts from algae. In the case of chloroplasts and mitochondria, examples of recent and ancient gene transfer to the chromosomes of their host cell illustrate the process of genetic merger in the wake of organelle origins.
Influence of the growth substrate on ester‐linked phospho‐ and glycolipid fatty acids of PAH‐degrading Mycobacterium sp. LB501T
Authors: Wick Lukas Y. , Pelz Oliver , Bernasconi Stefano M. , Andersen Nils , Harms Hauke 
Published: July 2003

SummaryThe influences of poorly water‐soluble anthracene on ester‐linked phospholipid fatty acid (PLFA) and glycolipid fatty acid (GLFA) profiles of Mycobacterium sp. LB501T were studied. Bacteria were cultivated on either anthracene or glucose (one culture with successively amended small doses of this substrate and one with excess concentrations) to distinguish between influences of the chemical structure and the bioavailability of the growth substrate. Results revealed that GLFA and PLFA profiles of M. sp. LB501T depended on the availability and the structure of the carbon source. Fatty acid profiles obtained with anthracene differed from those obtained with excess glucose. They were interpreted as a specific adaptation to this poorly bioavailable polycyclic aromatic hydrocarbon (PAH). In contrast, profiles obtained with low glucose concentrations showed clear signs of starvation stress. Stable carbon isotopic ratios (δ13C) of GLFA and PLFA of M. sp. LB501T were analysed to characterize the 13C‐fractionation during the biosynthesis of individual fatty acids and to evaluate their value as markers for substrate usage. Although the δ13C values of PLFA and GLFA showed differential isotope fractionation during anthracene‐ and glucose‐degradation, they were sufficiently distinct to be used as signatures of bacterial substrate usage.
Analysis of natural populations of Prochlorococcus spp. in the northern Red Sea using phycoerythrin gene sequences
Authors: Steglich Claudia , Post Anton F. , Hess Wolfgang R. 
Published: July 2003

SummaryMarine cyanobacteria of the genus Prochlorococcus belong to one of two ecotypes that are specifically adapted to either low light (LL) or high light (HL) conditions. Previous analyses of the differences in pigmentation and gene complement revealed that LL‐adapted ecotypes carry a gene cluster to produce a functional phycoerythrin, whereas in the fully sequenced genome of the HL‐adapted strain MED4, only a single and free‐standing cpeB gene occurs. This gene encodes a derived form of β‐phycoerythrin, the function of which has remained enigmatic so far. Here, an analysis of HL‐adapted Prochlorococcus strains from different ocean provinces revealed the presence of a cpeB gene highly similar to that of MED4. To investigate whether the presence of particular phycoerythrin genes is a common characteristic of the LL‐ and HL‐adapted ecotypes, primer sets targeting specific motifs in LL‐cpeB and HL‐cpeB were designed for polymerase chain reaction (PCR) analysis of Red Sea phytoplankton. A major PCR product for Prochlorococcus HL‐cpeB was obtained from samples taken at 5–70 m depth and for LL‐cpeB from 70–125 m. The high sensitivity of this approach allowed the detection of HL‐cpeB down to 100 m and LL‐cpeB as deep as 175 m. DNA sequence and phylogenetic analysis of 70 individual clones for HL‐cpeB and of 68 clones for LL‐cpeB revealed a monophyletic origin for the HL and LL sequences respectively. This study shows that cpeB sequences are suitable as very sensitive molecular markers for the study of natural populations of Prochlorococcus. The low sequence divergence of HL‐cpeB among Prochlorococcus strains, which have been isolated from the Mediterranean Sea, the Arabian Sea and the Southern Pacific Ocean as well as in populations from the Red Sea, suggests the HL‐cpeB gene to be conserved and its product to be functional in Prochlorococcus.
Effects of temperature and fertilizer on activity and community structure of soil ammonia oxidizers
Authors: Avrahami Sharon , Liesack Werner , Conrad Ralf 
Published: July 2003

SummaryWe investigated the effect of temperature on the activity of soil ammonia oxidizers caused by changes in the availability of ammonium and in the microbial community structure. Both short (5 days) and long (6.5, 16 and 20 weeks) incubation of an agricultural soil resulted in a decrease in ammonium concentration that was more pronounced at temperatures between 10 and 25°C than at either 4°C or 30–37°C. Consistently, potential nitrification was higher between 10 and 25°C than at either 4°C or 37°C. However, as long as ammonium was not limiting, release rates of N2O increased monotonously between 4 and 37°C after short‐term temperature adaptation, with nitrification accounting for about 35–50% of the N2O production between 4 and 25°C. In order to see whether temperature may also affect the community structure of ammonia oxidizers, we studied moist soil during long incubation at low and high concentrations of commercial fertilizer. The soil was also incubated in buffered (pH 7) slurry amended with urea. Communities of ammonia oxidizers were assayed by denaturant gradient gel electrophoresis (DGGE) of the amoA gene coding for the α subunit of ammonia monooxygenase. We found that a polymerase chain reaction (PCR) system using a non‐degenerated reverse primer (amoAR1) gave the best results. Community shifts occurred in all soil treatments after 16 weeks of incubation. The community shifts were obviously influenced by the different fertilizer treatments, indicating that ammonium was a selective factor for different ammonia oxidizer populations. Temperature was also a selective factor, in particular as community shifts were also observed in the soil slurries, in which ammonium concentrations and pH were better controlled. Cloning and sequencing of selected DGGE bands indicated that amoA sequences belonging to Nitrosospira cluster 1 were dominant at low temperatures (4–10°C), but were absent after long incubation at low fertilizer treatment. Sequences of Nitrosospira cluster 9 could only be detected at low ammonium concentrations, whereas those of Nitrosospira cluster 3 were found at most ammonium concentrations and temperatures, although individual clones of this cluster exhibited trends with temperature. Obviously, ammonia oxidizers are able to adapt to soil conditions by changes in the community structure if sufficient time (several weeks) is available.
Studies on pathogenic Vibrio parahaemolyticus during a warm weather season in the Seto Inland Sea, Japan
Authors: Alam M. Jahangir , Miyoshi Shin‐Ichi , Shinoda Sumio 
Published: July 2003

Summary Vibrio parahaemolyticus is a potentially pathogenic bacterium, occurring naturally in estuarine and marine environments throughout the world. The incidence of this organism in an aquatic environment depends upon many ecofactors. Sea water and organic material were collected during the warm weather season from a coast of the Seto Inland Sea, Japan, and analysed to determine V. parahaemolyticus densities and the occurrence of pathogenic strains, defined as those possessing tdh and/or trh genes by polymerase chain reaction (PCR), using isolated DNA from enrichment culture of the samples. About 99% of samples were positive for V. parahaemolyticus with densities of 3 to> 1400 cells per 100 ml of water or 10 g of organic samples by the most‐probable‐number (MPN)‐PCR technique, but only 76.6% were positive by the conventional MPN culture technique, with densities ranging from 3 to> 1400 cells per 100 ml of water or 10 g of organics. Furthermore, the tdh and trh genes were positive in 41.5% and 8.5% of samples, respectively, by the MPN‐PCR technique. No tdh and trh gene‐positive strains were isolated by the conventional MPN culture procedure. The difference in detection between the MPN culture and the MPN‐PCR techniques appeared to be significant and may be attributed to different detection sensitivities and other factors.