bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ascorbic acid inhibits the migration of walker 256 carcinosarcoma cells
Authors: Wybieralska Ewa , Koza Monika , Sroka Jolanta , Czyż Jarosław , Madeja Zbigniew 
Published: October 2007

AbstractThe results of several experimental studies have shown that ascorbic acid inhibits tumor growth and metastasis. Ascorbic acid is an antioxidant that acts as a scavenger for a wide range of reactive oxygen species (ROS). Both tumour metastasis and cell migration have been correlated with the intracellular ROS level, so it was postulated that the inhibitory effect of ascorbic acid derivatives on cell motility may be caused by scavenging of ROS. Time-lapse analyses of Walker 256 carcinosarcoma cell migration showed that both the speed of movement and the cell displacement were inhibited by ascorbic acid applied in concentrations ranging from 10 to 250 μM. This effect correlated with a reduction in the intracellular ROS level in WC 256 cells, suggesting that ROS scavenging may be a mechanism responsible for the inhibition of WC 256 cell migration. However, another potent antioxidant, N-acetyl-L-cysteine, also efficiently decreased the intracellular ROS level in WC 256 cells, but did not affect the migration of the investigated cells. These results demonstrate that intact, unmodified ascorbic acid applied in physiologically relevant and nontoxicconcentrations exerts an inhibitory effect on the migration of WC 256 carcinosarcoma cells, and that this may be one of the factors responsible for the anti-metastatic activity of vitamin C. However, our data does not support the hypothesis that the scavenging of intracellular ROS is the main mechanism in the inhibition of cancer cell migration by ascorbic acid.
Acidification induces Bax translocation to the mitochondria and promotes ultraviolet light-induced apoptosis
Authors: Yang Lin , Mei Yongyu , Xie Qifeng , Han Xiaoyan , Zhang Fucheng , Gu Lin , Zhang Yufeng , Chen Youming , Li Gang , Gao Zhiliang 
Published: October 2007

AbstractIt has been suggested that Bax translocation to the mitochondria is related to apoptosis, and that cytosol acidification contributes to apoptosis events. However, the mechanisms remain obscure. We investigated the effect of acidification on Bax translocation and on ultraviolet (UV) light-induced apoptosis. The Bax translocation assay in vitro showed that Bax translocated to the mitochondria at pH 6.5, whereas no Bax translocation was observed at pH 7.4. VHDBB cells expressing the GFP-Bax fusion protein were treated for 12 h with a pH 6.5 DMEM medium, nigericin (5 μg/ml) and UV light (50 J/cm2), separately or in combination, and Bax translocation to the mitochondria was determined by SDS-PAGE and Western blot, and apoptotic cell death was detected by flow cytometry. The results showed that some of the Bax translocated to the mitochondria in the cells treated with the normal medium, nigericin and UV in combination, whereas all of the Bax translocated to the mitochondria in the cells treated with the pH 6.5 medium, nigericin and UV in combination. In VHDBB cells treated for 12 h with nigericin, UV alone, and UV and nigericin in combination, the respective rates of apoptotic cell death were 25.08%, 33.25% and 52.88%. In cells treated with pH 6.5 medium and nigericin, pH 6.5 medium and UV, and pH 6.5 medium, nigericin and UV in combination, the respective rates of apoptotic cell death increased to 37.19%, 41.42% and 89.44%. Our results indicated that acidification induces Bax translocation from the cytosol to the mitochondria, and promotes UV lightmediated apoptosis. This suggests that there is a possibility of improving cancer treatment by combining acidification with irradiation or chemotherapeutic drugs.
The induction of apoptosis by daunorubicin and idarubicin in human trisomic and diabetic fibroblasts
Authors: Dragojew Sylwia , Marczak Agnieszka , Maszewski Janusz , Ilnicki Krzysztof , Jóźwiak Zofia 
Published: October 2007

AbstractIn this study, we investigated apoptosis induced in human trisomic and diabetic fibroblasts by daunorubicin (DNR) and its derivative, idarubicin (IDA). The cells were incubated with DNR or IDA for 2 h and then cultured in a drug-free medium for a further 2–48 h. The apoptosis in the cultured cell lines was assessed by biochemical analysis. We found that both drugs induced a timedependent loss of mitochondrial membrane potential, and a significant increase in intracellular calcium and caspase-3 activity. Mitochondrial polarization and changes in the level of intracellular calcium were observed during the first 2–6 h after drug treatment. Caspase-3 activation occurred in the late stages of the apoptotic pathway. Our findings also demonstrated that idarubicin was more cytotoxic and more effective than daunorubicin in inducing apoptosis in trisomic and diabetic fibroblasts.
Natriuretic peptides in cardiovascular diseases
Authors: Piechota Mariusz , Banach Maciej , Jacoń Anna , Rysz Jacek 
Published: October 2007

AbstractThe natriuretic peptide family comprises atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), dendroaspis natriuretic peptide (DNP), and urodilatin. The activities of natriuretic peptides and endothelins are strictly associated with each other. ANP and BNP inhibit endothelin-1 (ET-1) production. ET-1 stimulates natriuretic peptide synthesis. All natriuretic peptides are synthesized from polypeptide precursors. Changes in natriuretic peptides and endothelin release were observed in many cardiovascular diseases: e.g. chronic heart failure, left ventricular dysfunction and coronary artery disease.
Sclerotia of the acellular (true) slime mould Fuligo septica as a model to study melanization and anabiosis
Authors: Krzywda Anna , Petelenz Elżbieta , Michalczyk Dominika , Płonka Przemysław 
Published: October 2007

AbstractAcellular (true) slime moulds (Myxomycetes) are capable of a transition to the stage of sclerotium — a dormant form of plasmodium produced under unfavourable environmental conditions. In this study, sclerotia of Fuligo septica were analyzed by means of electron paramagnetic resonance (EPR) spectroscopy. The moulds were cultivated in vitro on filter paper, fed with oat flour, and kept until the plasmodia began to produce sclerotia. The obtained sclerotia differed in colour from yellow through orange to dark-brown. The EPR spectra revealed a free radical, melanin-like signal correlated with the depth of the colour; it was strongest in the dark sclerotia. Sclerotization only took place when the plasmodia were starved and very slowly dried. Only the yellow sclerotia were able to regenerate into viable plasmodia. This suggests that myxomycete cytoplasm dehydration is an active process regulated metabolically. Plasmodial sclerotization may therefore serve as a convenient model system to study the regulation of cytoplasmatic water balance, and sclerotia as a convenient material for EPR measurements, combining the quality of plasmodia with the technical simplicity of the measurements characteristic of dry spores. Darkening of the sclerotia is most probably a pathological phenomenon connected with the impairment of water balance during sclerotization.
Sedation with detomidine and acepromazine influences the endoscopic evaluation of laryngeal function in horses
Authors: Lindegaard C. , Husted L. , Ullum H. , Fjeldborg J. 
Published: October 2007

SummaryReasons for performing study: Endoscopy of the upper airways of horses is used as a diagnostic tool and at purchase examinations. On some occasions it is necessary to use sedation during the procedure and it is often speculated that the result of the examination might be influenced due to the muscle‐relaxing properties of the most commonly used sedatives.Objectives: To evaluate the effect of detomidine (0.01 mg/kg bwt) and acepromazine (0.05 mg/kg bwt) on the appearance of symmetry ofrima glottidis, ability to abduct maximally the arytenoid cartilages and the effect on recurrent laryngeal neuropathy (RLN) grade.Methods: Forty‐two apparently normal horses underwent endoscopic examination of the upper airways on 3 different occasions, under the influence of 3 different treatments: no sedation (control), sedation with detomidine and sedation with acepromazine. All examinations were performed with a minimum of one week apart. The study was performed as an observer‐blind cross‐over study.Results: Sedation with detomidine had a significant effect on the RLN grading (OR = 2.91) and ability maximally to abduct the left arytenoid cartilages (OR = 2.91). Sedation with acepromazine resulted in OR = 2.43 for the RLN grading and OR = 2.22 for the ability to abduct maximally. The ability to abduct maximally the right arytenoid cartilage was not altered.Conclusions: Sedating apparently healthy horses with detomidine or acepromazine significantly impairs these horses' ability to abduct fully the left but not the right arytenoid cartilage. This resulted in different diagnosis with respect to RLN when comparing sedation to no sedation.Potential relevance: Since the ability to abduct the right arytenoid cartilage fully is not altered by sedation, it is speculated that horses changing from normal to abnormal laryngeal function when sedated, might be horses in an early stage of the disease. To confirm or reject these speculations, further studies are needed. Until then sedation during endoscopy should be used with care.
Safety of an attenuated West Nile virus vaccine, live Flavivirus chimera in horses
Authors: Long M. T. , Gibbs E. P. J. , Mellencamp M. W. , Zhang S. , Barnett D. C. , Seino K. K. , Beachboard S. E. , Humphrey P. P. 
Published: October 2007

Summary Reasons for performing study: West Nile virus (WNV) infection is endemic and able to cause disease in naive hosts. It is necessary therefore to evaluate the safety of new vaccines. Objectives: To establish: 1) the safety of a modified live Flavivirus/West Nile virus (WN‐FV) chimera by administration of an overdose and testing for shed of vaccine virus and spread to uninoculated sentinel horses; 2) that this vaccine did not become pathogenic once passaged in horses; and 3) vaccine safety under field conditions. Methods: There were 3 protocols: 1) In the overdose/shed and spread study, horses were vaccinated with a 100x immunogenicity overdose of WN‐FV chimera vaccine and housed with sentinel horses. 2) A reversion to virulence study, where horses were vaccinated with a 20x immunogenicity overdose of WN‐FV chimera vaccine. Horses in both studies were evaluated for abnormal health conditions and samples obtained to detect virus, seroconversion and dissemination into tissues. 3) In a field safety test 919 healthy horses of various ages, breeds and sex were used. Results: Vaccination did not result in site or systemic reactions in either experimental or field‐injected horses. There was no shed of vaccine virus, no detection of vaccine virus into tissue and no reversion to virulence with passage. Conclusions: WN‐FV chimera vaccine is safe to use in horses with no evidence of ill effects from very high doses of vaccine. There was no evidence of reversion to virulence. In addition, administration of this vaccine to several hundred horses that may have been previously exposed to WNV or WNV vaccine resulted in no untoward reactions. Potential relevance: These studies establish that this live attenuated Flavivirus chimera is safe to use for immunoprophylaxis against WNV disease in horses.
Clinical, immunophenotypic and functional characterisation of T‐cell leukaemia in six horses
Authors: Rendle D. I. , Durham A. E. , Thompson J. C. , Archer J. , Mitchell M. , Saunders K. , Millere J. , Paillot R. , Smith K. C. , Kydd J. H. 
Published: October 2007

Summary Reasons for performing the study: Lymphoid leukaemia (LL) is rare in equids. In man, immunophenotypic classification identifies distinct leukaemic types with different treatment strategies. Improved understanding and classification of equine LL may allow similar advances. Objectives: To document the clinical, immunophenotypic and functional characteristics in 6 cases of equine LL of T‐cell origin. Methods: The clinical records and pathological findings from 6 cases of equine LL were analysed. Immunohistochemistry to identify T or B lymphocytes was performed on paraffin embedded tissues in 4 cases. Peripheral blood mononuclear cells (PBMC) were phenotyped for expression of CD4, CD8, MHC class I and II and B‐cell antigens in 4 cases using monoclonal antibodies (mAbs) and flow cytometry. Neoplastic lymphocytes from 4 horses were stimulated with mitogens. Results and conclusions: Six horses of various breeds were identified with LL of T‐cell origin. The clinical course and presenting signs varied. Neoplastic lymphocytes were identified in peripheral blood samples from all horses and tissue invasion was confirmed at examination post mortem in 4 horses. Immunophenotyping identified a predominance of CD3+ T‐cells in lymphoid tissues and CD4+ T‐cells in circulating peripheral blood mononuclear cells (PBMC) in the affected horses. Neoplastic lymphocytes from the 4 cases that were tested failed to proliferate in response to mitogens. Potential relevance: Characterisation of the clinical, pathological and immunological findings in 6 horses with LL has added to reports of this rare condition, characterised it in greater detail and therefore provides a starting point for further investigations.
Efficacy, duration, and onset of immunogenicity of a West Nile virus vaccine, live Flavivirus chimera, in horses with a clinical disease challenge model
Authors: Long M. T. , Gibbs E. P. J. , Mellencamp M. W. , Bowen R. A. , Seino K. K. , Zhang S. , Beachboard S. E. , Humphrey P. P. 
Published: October 2007

Summary Reasons for performing study: West Nile virus (WNF) is a Flavivirus responsible for a life‐threatening neurological disease in man and horses. Development of improved vaccines against Flavivirus infections is therefore important. Objectives: To establish that a single immunogenicity dose of live Flavivirus chimera (WN‐FV) vaccine protects horses from the disease and it induces a protective immune response, and to determine the duration of the protective immunity. Methods: Clinical signs were compared between vaccinated (VACC) and control (CTRL) horses after an intrathecal WNV challenge given at 10 or 28 days, or 12 months post vaccination. Results: Challenge of horses in the immunogenicity study at Day 28 post vaccination resulted in severe clinical signs of WNV infection in 10/10 control (CTRL) compared to 1/20 vaccinated (VACC) horses (P<0.01). None of the VACC horses developed viraemia and minimal histopathology was noted. Duration of immunity (DPI) was established at 12 months post vaccination. Eight of 10 CTRL exhibited severe clinical signs of infection compared to 1 of 9 VACC horses (P<0.05). There was a significant reduction in the occurrence of viraemia and histopathology lesion in VACC horses relative to CTRL horses. Horses challenged at Day 10 post vaccination experienced moderate or severe clinical signs of WNV infection in 3/3 CTRL compared to 5/6 VACC horses (P<0.05). Conclusions: This novel WN‐FV chimera vaccine generates a protective immune response to WNV infection in horses that is demonstrated 10 days after a single vaccination and lasts for up to one year. Potential relevance: This is the first USDA licensed equine WNV vaccine to utilise a severe challenge model that produces the same WNV disease observed under field conditions to obtain a label claim for prevention of viraemia and aid in the prevention of WNV disease and encephalitis with a duration of immunity of 12 months.
Hypertrophy and physiological death of equine chondrocytes in vitro
Authors: Ahmed Y. A. , Tatarczuch L. , Pagel C. N. , Davies H. M. , Mirams M. , Mackie E. J. 
Published: October 2007

Summary Reasons for performing study: Equine osteochondrosis results from a failure of endochondral ossification during skeletal growth. Endochondral ossification involves chondrocyte proliferation, hypertrophy and death. Until recently no culture system was available to study these processes in equine chondrocytes. Objective: To optimise an in vitro model in which equine chondrocytes can be induced to undergo hypertrophy and physiological death as seen in vivo. Methods: Chondrocytes isolated from fetal or older (neonatal, growing and mature) horses were cultured as pellets in 10% fetal calf serum (FCS) or 10% horse serum (HS). The pellets were examined by light and electron microscopy. Total RNA was extracted from the pellets, and quantitative PCR carried out to investigate changes in expression of a number of genes regulating endochondral ossification. Results: Chondrocytes from fetal foals, grown as pellets, underwent hypertrophy and died by a process morphologically similar to that seen in vivo. Chondrocytes from horses age >5 months did not undergo hypertrophy in pellet culture. They formed intramembranous inclusion bodies and the cultures included cells of osteoblastic appearance. Pellets from neonatal foals cultured in FCS resembled pellets from older horses, however pellets grown in HS underwent hypertrophy but contained inclusion bodies. Chondrocytes from fetal foals formed a typical cartilage‐like tissue grossly and histologically, and expressed the cartilage markers collagen type II and aggrecan mRNA. Expression of Sox9, collagen type II, Runx2, matrix metalloproteinase‐13 and connective tissue growth factor mRNA increased at different times in culture. Expression of fibroblast growth factor receptor‐3 and vascular endothelial growth factor mRNA decreased with time in culture. Conclusions: Freshly isolated cells from fetal growth cartilage cultured as pellets provide optimal conditions for studying hypertrophy and death of equine chondrocytes. Potential relevance: This culture system should greatly assist laboratory studies aimed at elucidating the pathogenesis of osteochondrosis.
Influence of breed and oestrous cycle on endometrial gland surface density in the mare
Authors: Lefranc A.‐C. , Allen W. R. 
Published: October 2007

Summary Reasons for performing study: The diffuse noninvasive epitheliochorial equine placenta develops an intimate and complex interdigitation with the maternal endometrium throughout gestation to maximise surface contact and, consequently, optimise nutritional and gaseous maternofetal exchanges. A significant reduction occurs in the surface density of microcotyledons on the placentae of Welsh Pony vs. Thoroughbred mares that may relate to a difference in either the number or density of endometrial glands between these breeds. Objectives: To examine this hypothesis and to determine the influence of the oestrous cycle upon the development and surface density of endometrial glands. Methods: Endometrial biopsies were taken under videoendoscopic visual control from the base of a uterine horn from young, fertile, Welsh Pony and Thoroughbred mares at defined stages of the oestrous cycle. Computer‐assisted morphometric analysis then permitted the surface density of endometrial glands within the stratum spongiosum to be assessed. Conclusions: There was a statistically significant reduction in endometrial gland surface density in the Welsh Pony vs. Thoroughbred mares during both oestrus and dioestrus. Potential relevance: A substantial upregulation of epidermal growth factor (EGF) mRNA in the epithelial cells lining the apical portions of endometrial glands has been demonstrated in pregnant mares between Days 35 and 40 after ovulation, coincident with the onset of interdigitation between the allantochorion and endometrium to form the microcotyledonary placenta. The increased surface density of endometrial glands noted in the uteri of Thoroughbred mares might account for the greater surface density of placental microcotyledons in this breed.
Alternative vaccination against equine botulism (BoNT/C)
Authors: Frey J. , Eberle S. , Stahl C. , Mazuet C. , Popoff M. , Schatzmann E. , Gerber V. , Dungu B. , Straub R. 
Published: October 2007

Summary Reasons for performing study: In Europe the incidence of botulism in horses has increased in the last decade due to the growing popularity of haylage feeding. Recombinant vaccines are safer and less expensive to produce and are generally better tolerated than toxoids. Objectives: To investigate whether the recombinant C‐terminal half of the heavy chain of the botulinum neurotoxin C (Hc BoNT/C) in combination with an immunstimulatory adjuvant is an appropriate vaccine candidate for horses by testing its efficacy to induce neutralising antibodies and by comparing its immunogenic properties and adverse reactions to a commercial toxoid vaccine. Formation of oedema and local pain reactions were assessed. ELISA and Western blot assay against Hc BoNT/C and testing of neutralising antibody induction in a mouse protection assay were used to evaluate the immune response. Results: With the recombinant vaccine, only minor local swelling with full recovery after 5 days was noted after brisket injections. The toxoid vaccine produced local, painful reactions with longer recovery periods of up to 2 weeks. Horses vaccinated with either vaccine induced neutralising antibodies after the second booster vaccination, while seroconversion on ELISA and Western blot to Hc BoNT/C was apparent after the first recombinant vaccination, and at various time points in the vaccination schedule in horses that received commercial toxoid vaccine. Conclusion: The recombinant vaccine showed fewer adverse reactions compared to the only commercially available vaccine but induced similar concentrations of neutralising antibodies. There was no correlation between the serological response to Hc BoNT/C and the neutralising capacity of serum. Potential relevance: Recombinant Hc BoNT/C is an appropriate vaccine candidate to stimulate production of neutralising antibodies against botulinum neurotoxin C in horses and creates only minor local reactions at the injection site.
A case‐control study of factors associated with development of clinical disease due to West Nile virus, Saskatchewan 2003
Authors: Epp T. , Waldner C. , Townsend H. G. G. 
Published: October 2007

Summary Reasons for performing study: West Nile virus (WNV) was first diagnosed in Saskatchewan equids in 2002. A WNV epidemic was considered highly likely for 2003, which would provide a unique opportunity to study all aspects of WNV subclinical infection and clinical disease development in a relatively naive population. Hypothesis: There are individual equid attributes and management risk factors associated with development of clinical disease. Specifically, this study could address the question of vaccine efficacy for the prevention of development of clinical disease. Methods: A case‐control study was conducted in the summer of 2003 during a province‐wide outbreak of WNV. Between 5 and 10 equids were sampled from each of 23 case premises with clinical disease and 23 control premises with no apparent or confirmed clinical disease. Data were analysed to identify risk factors for the development of clinical disease. Results: The proportion of equids serologically positive for natural exposure to West Nile virus was 64% (193/300). Nonvaccinated equids were 23 times (95%CI limits 3.0, 168.5, P = 0.002) more likely to develop clinical disease than those vaccinated. The estimate of vaccine efficacy in this field study was 96% (95%CI limits 67%, 99%). Conclusions: The study demonstrated that vaccination was strongly associated with the prevention of clinical disease. Potential relevance: Vaccination is an effective, practical method of prevention of clinical disease.