bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methyl palmitate prevents CCl4‐induced liver fibrosis
Authors: Rodríguez‐Rivera Adriana , Galicia‐Moreno Marina , Reyes‐Gordillo Karina , Segovia José , Vergara Paula , Moreno Mario G. , Shibayama Mineko , Tsutsumi Víctor , Muriel Pablo 
Published: July 2008

AbstractLiver fibrosis is characterized by an excess of collagen fiber deposition, and it is known that Kupffer cells play an important role by immunomodulation of the toxic response. Methyl palmitate (MP) is an effective Kupffer cell inhibitor. The aim of this work was to evaluate the effect of MP on experimental liver fibrosis. Four groups were formed: the control group, which received the vehicles only; CCl4 group (0.4 g kg−1, i.p., three times a week, for eight weeks); CCl4 plus MP (300 mg kg−1, i.p., daily); and MP alone. Alanine aminotransferase was increased by CCl4, and MP did not prevent this increase. Lipid peroxidation was increased markedly by CCl4; again, MP was not able to prevent this effect. Fibrosis increased nearly 6‐fold (measured as liver hydroxyproline content) in the CCl4 group; MP preserved the normal content of collagen. These results were corroborated by histopathology. To elucidate the antifibrogenic mechanism of MP, we measured the production of TGF‐β; CCl4 increased this cytokine several‐fold, and MP abolished this increase. Collectively the present results indicate that MP possesses a strong antifibrogenic effect at least in the CCl4 model of fibrosis. The antifibrotic effect of MP is probably associated with its ability to reduce TGF‐β content, maybe by immunomodulation of Kupffer cells functioning. Copyright © 2008 John Wiley & Sons, Ltd.
Application of structure–activity relationships to investigate the molecular mechanisms of hepatocyte toxicity and electrophilic reactivity of α,β‐unsaturated aldehydes
Authors: Chan Katie , Poon Raymond , O'Brien Peter J. 
Published: July 2008

AbstractCovalent binding of reactive electrophiles to cellular targets is a molecular interaction that has the potential to initiate severe adverse biological effects. Therefore, a measure for electrophilic reactivity with biological nucleophiles could serve as an important correlate to toxic effects such as hepatocyte death. To determine if electrophile reactivity correlates with rat hepatocyte cytotoxicity, the inherently electrophilic α,β‐unsaturated aldehydes were chosen for investigation. Reactivity was measured with simple assays that used glutathione, a soft nucleophile, and butylamine, a harder nucleophile, as models for protein thiol and amine nucleophilic sites, respectively. Despite their higher reactivity with thiols, a linear relationship was only observed between hepatocyte cytotoxicity and amine reactivity. Structure–activity relationships were also investigated for hepatocyte toxicity, and results showed toxicity was well modelled by log P and electronic parameters ELUMO and partial charge of the carbonyl carbon (
). Hydrophobicity and electronic descriptors were only significant in separate distinct models, suggesting that there were simultaneously occurring mechanisms that affected toxicity. Log P was linked to the ease of oxidation by a microsomal aldehyde dehydrogenase enzyme, while the electronic descriptors and amine reactivity were linked to direct alkylation. Even with the presence of electrophile characteristics, α,β‐unsaturated aldehyde hepatocyte toxicity could not be predicted exclusively by electrophilic reactivity as oxidative metabolism was also a factor for toxicity. Copyright © 2008 John Wiley & Sons, Ltd.
Increased levels of urinary nitrite and nitrotyrosine in Yusho victims 40 years after accidental poisoning with polychlorinated biphenyls in Nagasaki, Japan
Authors: Shimizu Kazuhiro , Ogawa Fumihide , Thiele Jens J. , Lee Jeong Boem , Bae SangJae , Sato Shinichi 
Published: July 2008

AbstractForty years have passed since the accidental poisoning with polychlorinated biphenyls (PCB) in Japan in 1968, named Yusho. High concentrations of PCB are still detected in the serum of the Yusho victims. PCB produces superoxide (O2−) in the metabolic process and we reported high concentrations of serum nitrite, a stable metabolite reflecting nitric oxide (NO), in the Yusho victims. NO reacts with O2− and immediately produces peroxynitrite (ONOO−). ONOO− causes nitration of tyrosine residues and produces nitrotyrosine (NT). Therefore, we measured urinary concentrations of nitrite and NT in the victims and age‐matched controls. The mean urinary concentrations of nitrite and NT were significantly higher than in the controls. There was a positive correlation between urinary nitrite and NT in the Yusho victims. Furthermore, there was a positive correlation between the ratio of urinary NT to nitrite and serum PCB concentrations in the Yusho victims. It was considered that the emergence of some ailments could be presumed to have been caused by high levels of urinary nitrite and NT in the Yusho victims. Copyright © 2008 John Wiley & Sons, Ltd.
Secretion of cortisol and aldosterone as a vulnerable target for adrenal endocrine disruption — screening of 30 selected chemicals in the human H295R cell model
Authors: Ullerås Erik , Ohlsson Åsa , Oskarsson Agneta 
Published: July 2008

AbstractThe adrenal gland is a vulnerable target for toxic insult. Disruption of adrenal steroidogenesis and hormone secretion may cause serious effects on human health. A human in vitro model is needed to predict effects, and elucidate mechanisms of endocrine disruption and adrenal toxicity. The human adrenocortical cell line H295R has been used to screen for effects on sex hormones. Here, we have analyzed the effect of 30 potential endocrine disrupting chemicals on the secretion of cortisol and aldosterone from the H295R cells, using specific ELISA assays. The effect of chemicals was analyzed for basal and forskolin‐ or angiotensin II‐stimulated hormone secretion. The chemicals were tested at the highest concentration where they displayed no evident unspecific cytotoxicity. Quantitative and qualitative differences in effects on hormone secretion were demonstrated for the various chemicals. A subset of the chemicals displayed different effects on cortisol and aldosterone secretion, and in some cases the effects were different between basal and stimulated hormone secretion. Aminoglutethimide, prochloraz, ketoconazole, 6‐hydroxyflavone, imazalil and etomidate had the most marked inhibitory effects on cortisol (with or without forskolin) and ketoconazole, 6‐hydroxyflavone, imazalil and etomidate had the most marked effects on aldosterone (with or without angiotensin II). The results are discussed in terms of known effects, structural similarity and possible mechanisms. We have shown that adrenal steroidogenesis is a vulnerable target for toxic insult and that the H295R assay is a useful in vitro model for screening purposes. Copyright © 2008 John Wiley & Sons, Ltd.
Paratracheal lymph nodes: A new sonographic finding in autoimmune thyroiditis
Authors: Serres‐Créixams Xavier , Castells‐Fusté Ignasi , Pruna‐Comella Xavier , Yetano‐Laguna Victorina , Garriga‐Farriol Victòria , Gallardo‐Agromayor Elena 
Published: July 2008

AbstractPurpose.To assess the clinical value of paratracheal lymph nodes (PLNs) as a novel sonographic finding in autoimmune thyroiditis (AT).Methods.A total of 309 consecutive patients underwent sonographic examinations of the thyroid between 1998 and 2003. A single radiologist assessed the sonographic findings of AT and PLNs. All patients underwent serological tests for antimicrosomal antibodies (AMAs). Patients with clinical, cytological, or laboratory findings of thyroiditis formed the AT group with a positive AMA test (n = 199). Controls were patients with no signs of nodular thyroid disease, normal thyrotropin, negative AMA, and benign cytology (n = 110).Results.PLNs were seen in 184 of 199 patients in the AT group and in 28 of 110 controls (P < 0.001) (sensitivity of 93.4%, specificity of 74.5% in the diagnosis of AT). PLNs in controls were fewer (2.8 ± 1.5 versus 4.7 ± 2.6; P < 0.001) and smaller (8.2 ± 2.4 mm versus 10.7 ± 3.3 mm; P < 0.001) than in the AT group.Conclusion.PLNs are often present in patients with AT and are detectable with sonography. Radiologists should be aware of the importance of including the paratracheal region in the evaluation of the thyroid gland. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Improved prenatal aneuploidy screening using the novel advanced first‐trimester screening algorithm: A multicenter study of 10,017 pregnancies
Authors: Schmidt Peter , Hörmansdörfer Cindy , Pruggmayer Michael , Schütte Christian , Neumann Armin , Gerritzen Andreas , Vaske Bernhard , Hillemanns Peter , Scharf Alexander 
Published: July 2008

AbstractPurpose.It has been postulated that the maternal age component should be completely excluded from first‐trimester screening (FTS) for fetal aneuploidies. In this study, we tested a new algorithm known as advanced first‐trimester screening (AFS), which disregards maternal age.Method.In a multicenter study, FTS findings were retrieved from 10,017 pregnancies. FTS risk assessment was performed using the Nicolaides method, and the AFS score was calculated. The results of both methods were compared.Results.Within this population, 81 fetuses had an abnormal karyotype. The sensitivity of the 2 algorithms was 86.4%. When the AFS method was used, the positive predictive value rose from 9.6% (FTS) to 12.4% (AFS). Using AFS, the test positive rate could be decreased by 161 cases (−22.2%) (p < 0.0001), due to a reduction of false positive cases. As a result, the false positive rate of AFS was 24.5% lower than that of FTS, while the same number of aneuploidies was detected.Conclusion.AFS can markedly reduce the rate of false positive test results. If these results are confirmed by larger multicenter studies, the new AFS will represent a great improvement in fetal aneuploidy screening. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Extracranial and intracranial vertebral artery dissection: Long‐term clinical and duplex sonographic follow‐up
Authors: Wessels Tiemo , Mosso Maria , Krings Timo , Klötzsch Christof , Harrer Judith U. 
Published: July 2008

AbstractPurpose.To determine the value of color Doppler sonography (CDUS) in the diagnosis and follow‐up of patients with extracranial and intracranial vertebral artery (VA) dissection.Method.Thirty‐three patients aged 42 ± 12 years with 40 VADS confirmed via digital subtraction angiography (DSA) (n = 37) and magnetic resonance angiography (MRA) (n = 3) were included in the study. All patients were investigated with extracranial CDUS and transcranial CDUS (TCCDUS) over a mean ± SD follow‐up period of 42 ± 24 months and occurrence of new ischemic symptoms was assessed. Sonographic results were compared with initial and follow‐up angiographic results.Results.At presentation, 24/33 (73%) patients had suffered an ischemic stroke, 5/33 (15%) had a transient ischemic attack (TIA), and 4/33 (12%) were asymptomatic. Two patients had a recurrent vertebrobasilar TIA; there was no recurrent stroke. The initial DSA findings consisted of 14 stenoses, 20 tapered occlusions, and 6 pseudoaneurysms. During follow‐up, 63% of the vessels recanalized. Sonographic findings were consistent with angiographic findings in 80% at the initial examination and in 86% during follow‐up. The main reason for discordant results was the failure of CDUS to detect pseudoaneurysms. No recurrence occurred in the vertebral arteries (VA), but 1 patient had an asymptomatic carotid artery dissection during follow‐up.Conclusion.Recurrent TIA or stroke after VAD appears to be extremely rare, independent of recanalization or persistent occlusion of the affected artery. CDUS and TCCDUS provide reliable follow‐up of VAD in all patients presenting with stenosis or occlusion, but do not allow for detection of pseudoaneurysms of the VA. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Hybridization betweenCrocodylus acutusandCrocodylus moreletiiin the Yucatan Peninsula: I. evidence from mitochondrial DNA and morphology
Authors: Cedeño‐Vázquez José Rogelio , Rodriguez David , Calmé Sophie , Ross James Perran , Densmore Llewellyn D. , Thorbjarnarson John B. 
Published: July 2008

AbstractThe American crocodile (Crocodylus acutus) and the Morelet's crocodile (C. moreletii) are broadly sympatric in Belize and Mexico. The presence of morphologically anomalous individuals in the overlapping range area suggests possible hybridization between these species. Analysis of 477 base pairs of the mitochondrial tRNAPro‐tRNAPhe‐Dloop region revealed the presence of pureC.acutus(N=43) andC. moreletii(N=56), as well as a high proportion of interspecific hybrids (N=17, 14.6%) in the Yucatan Peninsula, Mexico. Although all individuals could be assigned to one species or other based on phenotypic characters, some had been characterized as potential hybrids in the field by anomalous scale counts. The hybridization zone lies along the area of sympatry betweenC. acutusandC. moreletiiinvestigated in this study, but extends further inland if hybrid localities from Belize are included. Hybridization in the Yucatan Peninsula is bidirectional, which indicates considerably more genetic contact between these species than previously recognized, and is probably more detrimental to the genetic integrity of smallerC. acutuspopulations. A more intensive study of the pattern of hybridization is warranted and supports continued classification ofC. acutusas a critically threatened species in the Yucatan Peninsula.J. Exp. Zool. 309A:661–673, 2008. © 2008 Wiley‐Liss, Inc.
Spider silk aging: initial improvement in a high performance material followed by slow degradation
Authors: Agnarsson Ingi , Boutry Cecilia , Blackledge Todd A. 
Published: July 2008

AbstractSpider silk possesses a unique combination of high tensile strength and elasticity resulting in extraordinarily tough fibers, compared with the best synthetic materials. However, the potential application of spider silk and biomimetic fibers depends upon retention of their high performance under a variety of conditions. Here, we report on changes in the mechanical properties of dragline and capture silk fibers from several spider species over periods up to 4 years of benign aging. We find an improvement in mechanical performance of silk fibers during the first year of aging. Fibers rapidly decrease in diameter, suggesting an increase in structural alignment and organization of molecules. One‐year old silk also is stiffer and has higher stress at yield than fresh silk, whereas breaking force, elasticity, and toughness either improve or are unaffected by early aging. However, 4‐year old silk shows signs of degradation as the breaking load, elasticity, and toughness are all lower than in fresh silk. Aging, however, does not reduce the tensile strength of silk. These data suggest initially rapid reorganization and tighter packaging of molecules within the fiber, followed by longer‐term decomposition. We hypothesize that possibly the breakdown of amino acids via emission of ammonia gas, as is seen in long‐term aging of museum silkworm fabrics, may contribute. Degradation of spider silk under benign conditions may be a concern for efforts to construct and utilize biomimetic silk analogs. However, our findings suggest an initial improvement in mechanical performance and that even old spider silk still retains impressive mechanical performance. J. Exp. Zool. 309A:494–504, 2008. © 2008 Wiley‐Liss, Inc.
Ectopic dermal ridge configurations on the interdigital webbings and postaxial marginal portion of the hindlimb in Hammertoe mutant mice (Hm)
Authors: Kimura Sumiko , Schaumann Blanka A. , Shiota Kohei 
Published: July 2008

AbstractThe effects of the hereditary malformation of Hammertoe mutant mice (gene symbol Hm) on the digital pads and dermal ridge configurations on their hindlimbs were examined. In the wild‐type (+/+) mice with normally separated digits, dermal ridges developed only on the pads. Heterozygous (Hm/+) and homozygous (Hm/Hm) mutant mice, however, had a broad big toe, fused interdigital soft tissues, reduced claws, an extra rudimentary postaxial digit and camptodactyly. The dermal ridges appeared not only on the pads, affected in their number and configurations, but also on the ventral surface of the interdigital webbings and postaxial marginal area exhibiting an extra rudimentary digit and webbing. These aberrant configurations may be related to the abnormal occurrence of programmed cell death (PCD) in the interdigital zones and the postaxial marginal portion in Hm/+ and Hm/Hm mice. That is, the diminished cell death may fail to decrease the cell density in the interdigital zones and postaxial marginal portion and result in the webbing and an extra rudimentary digit and webbing, respectively. Simultaneously, it could also interrupt the migration of surviving cells of these areas toward the neighboring digits and the distal area of the sole and produce the ectopic dermal ridges on the way to the as yet unformed (presumptive) digital and plantar volar pads. The present findings suggest that normal interdigital and pre/postaxial PCD contributes not only to the separation of digits, the initial formation of individual digits of different sizes, and the inhibition of the extra digit but also to the development of the presumptive digital and plantar pads, including dermal ridges. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Recombinant arginine deiminase reduces inducible nitric oxide synthase iNOS‐mediated neurotoxicity in a coculture of neurons and microglia
Authors: Yu Hao‐Hsin , Wu Fe‐Lin Lin , Lin Shan‐Erh , Shen Li‐Jiuan 
Published: July 2008

AbstractModulation of nitric oxide (NO) production is considered a promising approach to therapy of diseases involving excessive inducible nitric oxide synthase (iNOS) expression, such as certain neuronal diseases. Recombinant arginine deiminase (rADI, EC3.5.3.6) catalyzes the conversion of L‐arginine (L‐arg), the sole substrate of NOS for NO production, to L‐citrulline (L‐cit) and ammonia. To understand the effect of the depletion of L‐arg by rADI on NO concentration and neuroprotection, a direct coculture of neuron SHSY5Y cells and microglia BV2 cells treated with lipopolysaccharide (LPS) and interferon‐γ (IFN‐γ) was used as a model of iNOS induction. The results showed that rADI preserved cell viability (4‐fold higher compared with the cells treated with LPS/IFN‐γ only) by the MTT assay, corresponding with the results of neuronal viability by neuron‐specific immunostaining assay. NO production (mean ± SD) decreased from 67.0 ± 1.3 to 19.5 ± 5.5 μM after a 2‐day treatment of rADI by the Griess assay; meanwhile, induction of iNOS protein expression by rADI was observed. In addition, rADI substantially preserved the neuronal function of dopamine uptake in the coculture. The replenishment of L‐arg in the coculture eliminated the neuroprotective and NO‐suppressive effects of rADI in the coculture, indicating that L‐arg played a crucial role in the effects of rADI. These results highlight the important role of L‐arg in the neuron‐microglia coculture in excessive induction of iNOS. Regulation of L‐arg by ADI demonstrated that rADI has a potentially therapeutic role in iNOS‐related neuronal diseases. © 2008 Wiley‐Liss, Inc.
Light and food signals cooperate to entrain the rat pineal circadian system
Authors: Wu Tao , Jin Yuanxiang , Kato Hisanori , Fu Zhengwei 
Published: July 2008

AbstractLight and food signals are two dominant Zeitgeber for central and peripheral circadian clocks, respectively. However, whether and how changes in light and food stimuli affect circadian rhythms of mammalian pineal clock genes are still largely unknown. For the first time, in the present study, we established a method for analysis of the expression levels of most clock genes (Bmal1, Per1, Per2, Per3, Cry1, Dec1 and Dec2) and AANAT in a single rat pineal gland and used it to investigate individual and cooperative effects of feeding and light cycle reversals on the pineal circadian system. Feeding reversal (RF) alone for 7 days had only weak effect on the rhythmicity of clock gene expression in the pineal gland, whereas light/dark reversal for the same period without any change in the feeding regime could not absolutely reverse the expression phases of all examined genes either. However, reversal of the LD cycle together with the feeding regime completely resynchronized the circadian gene expression in the pineal gland within 7 days. These data suggest that photic regulation is the dominant cue that synchronizes the pineal circadian rhythm more efficiently than the feeding‐related cue, but food availability does contribute to reentrainment of the pineal circadian system. In addition, the inability of RF in the pineal circadian system suggests that the pineal gland is more strongly coupled to the master clock than other peripheral organs and alternatively distinguishes it from other peripheral organs in the hierarchically organized mammalian circadian systems. © 2008 Wiley‐Liss, Inc.
Fibroblast growth factor‐2 mRNA expression in the brainstem and spinal cord of normal and chronic spinally transected urodeles
Authors: Moftah Marie , Landry Marc , Nagy Frédéric , Cabelguen Jean‐Marie 
Published: July 2008

AbstractDescending pathways in the spinal cord of adult urodele amphibians show a high regenerative ability after body spinal cord transection; regenerated axons regrow into the transected spinal cord, and hindlimb locomotor recovery occurs spontaneously. Little is currently known about the molecular basis of spinal cord regeneration in urodeles, but it is believed that fibroblast growth factor‐2 (FGF2) may play an important role by inducing proliferation of neural progenitor cells. The aim of our study, using in situ hybridization in adult Pleurodeles waltlii, was twofold: 1) to document FGF2 mRNA expression pattern along the brainstem‐spinal cord of intact salamanders and 2) to investigate the changes in this pattern in animals unable to display hindlimb locomotor movements and in animals having fully recovered hindlimb locomotor activity after body spinal cord transection. This design establishes a firm basis for further studies on the role of FGF2 in functional recovery of hindlimb locomotion. Our results revealed a decreasing rostrocaudal gradient in FGF2 mRNA expression along the brainstem‐spinal cord in intact animals. They further demonstrated a long‐lasting up‐regulation of FGF2 mRNA expression in response to spinal transection at the midtrunk level, both in brainstem and in the spinal cord below the injury. Finally, double immunolabeling showed that FGF2 was up‐regulated in neuroglial, presumably undifferentiated, cells. Therefore, we propose that FGF2 may be involved in cell proliferation and/or neuronal differentiation after body spinal cord transection in salamander and could thus play an important role in functional recovery of locomotion after spinal lesion. © 2008 Wiley‐Liss, Inc.