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Antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats
2014
Murahata, Yusuke | Miki, Yuya | Hikasa, Yoshiaki
This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 2 mg/kg BW xylazine intramuscularly, and saline (as the control); 160 μg/kg BW prazosin; or 40, 160, or 480 μg/kg BW atipamezole or yohimbine intravenously 0.5 h later. Urine and blood samples were collected 10 times over 8 h. Urine volume, pH, and specific gravity; plasma arginine vasopressin (AVP) concentration; and creatinine, osmolality, and electrolyte values in both urine and plasma were measured. Both atipamezole and yohimbine antagonized xylazine-induced diuresis, but prazosin did not. The antidiuretic effect of atipamezole was more potent than that of yohimbine but not dose-dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed xylazine-induced decreases in both urine specific gravity and osmolality, and the increase in free water clearance. Glomerular filtration rate, osmolar clearance, and plasma electrolyte concentrations were not significantly altered. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP concentration, although the highest dose of both atipamezole and yohimbine increased plasma AVP concentration initially and temporarily, suggesting that this may in part influence antidiuretic effects of both agents. The diuretic effect of xylazine in cats may be mediated by α2-adrenoceptors but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against xylazine-induced diuresis in clinically normal cats.
Mostrar más [+] Menos [-]The interaction of nitrous oxide and fentanyl on the minimum alveolar concentration of sevoflurane blocking motor movement (MACNM) in dogs
2014
Seddighi, Reza | Doherty, Thomas J. | Kukanich, Butch | Egger, Christine M. | Henn, Melissa A. | Long, Whitney M. | Rohrbach, Barton W.
The study objective was to determine the effects of 70% nitrous oxide (N2O) and fentanyl on the end-tidal concentration of sevoflurane necessary to prevent movement (MACNM) in response to noxious stimulation in dogs. Six healthy, adult, intact male, mixed-breed dogs were used on 3 occasions in a randomized crossover design. After induction of anesthesia with sevoflurane, each of the following treatments was randomly administered: fentanyl loading dose (Ld) of 15 μg/kg and infusion of 6 μg/kg per hour [treatment 1 (T1)], 70% N2O (T2), or fentanyl (Ld of 15 μg/kg and infusion of 6 μg/kg per hour) combined with 70% N2O (T3). Each dog received each of the 3 treatments once during the 3-week period. Determination of MACNM was initiated 90 min after the start of each treatment. The values were compared using the baseline MACNM, which had been determined in a previous study on the same group of dogs. Data were analyzed using a mixed-model analysis of variance (ANOVA) and Tukey-Kramer tests, and expressed as least squares mean ± SEM. The baseline MACNM decreased by 36.6 ± 4.0%, 15.0 ± 4.0%, and 46.0 ± 4.0% for T1, T2, and T3, respectively (P < 0.05), and differed (P < 0.05) among treatments. Mean fentanyl plasma concentrations did not differ (P ≥ 0.05) between T1 (3.70 ± 0.56 ng/mL) and T3 (3.50 ± 0.56 ng/mL). The combination of fentanyl and N2O resulted in a greater sevoflurane MACNM sparing effect than either treatment alone.
Mostrar más [+] Menos [-]Evolution of antimicrobial resistance of <i>Salmonella enteritidis</i> (1972–2005)
2014
Jermaine Khumalo | Bamusi Saidi | Joshua Mbanga
With the extensive use of antibiotics in livestock production, surveillance revealed an increase in Salmonella resistance to the commonly used antimicrobials in veterinary and public health. This serious threat to health care is further exacerbated by the limited epidemiological information about the common zoonotic agent, Salmonella enteritidis, required to determine antibiotic therapy. The aim was to characterise the antimicrobial resistance patterns of S. enteritidis isolates across different timelines (1972–2005) with accompanying genetic changes being investigated. Thirty-seven stored S. enteritidis isolates were collected from the Central Veterinary Laboratory, Harare, with antimicrobial susceptibility determined against eight antibiotics. Plasmids were isolated to analyse any genetic variation. An overall significant increase in resistance (p < 0.05) to nalidixic acid (0% – 10%), ampicillin (14.3% – 50%), tetracycline (14.3% – 30%) and erythromycin (71.4% – 100%) was observed across the timeline. However, the highest rates of susceptibility were maintained for gentamicin, sulphamethoxazole-trimethoprim, kanamycin and chloramphenicol. We report an increase in multidrug resistance (MDR) of 14.2% – 50% with an increase in resistotypes and plasmid profiles across the timeline. Eleven plasmid profiles were obtained in the 37 isolates studied with a minority of isolates (21.6%, 8/37) harbouring a 54 kb plasmid, commonly serovar-specific. A concerning increase in antimicrobial resistance to commonly administered drugs was observed across the timeline. The surge in MDR is of great concern and implies the need for consistent antimicrobial stewardship. No correlation was observed between the plasmid and antibiotic profiles.
Mostrar más [+] Menos [-]Prevalence of bovine tuberculosis in a dairy cattle farm and a research farm in Ghana
2014
Adwoa Asante-Poku | Kwame G. Aning | Bashiru Boi-Kikimoto | Dorothy Yeboah-Manu
The aim of the study was to estimate the prevalence of bovine tuberculosis (BTB) and to identify the mycobacterial species causing BTB in a dairy farm and research farm. Six hundred and eighty-five cattle were screened for BTB by using the Comparative intradermal tuberculin test (CTT). Positive reactors were slaughtered and carcasses were taken for isolation of mycobacterial species. This was followed by speciation of isolates using both standard conventional and molecular assays. Seventeen of the cattle were positive by CTT, giving a crude BTB prevalence of 2.48% among cattle from the two farms. Six of the 17 samples (35.30%) yielded positive acid-fast bacilli cultures and three of the isolates were identified as Mycobacterium tuberculosis complex (MTBC), which were sub-divided into two Mycobacterium tuberculosis sensu scrito (Mtb) and one Mycobacterium africanum; the remaining three were Mycobacterium other than tuberculoisis (MOTT). Spoligotyping further characterised the two Mtb isolates as Ghana (spoligotype Data Base 4 number 53) and Latin American Mediterranean (LAM), whilst spoligotyping and Single Nucleotide Polymorphism (SNP) analysis typed the M. africanum as West African 1. Microseq 500 analysis identified two of the MOTT as Mycobacterium flavescens and Mycobacterium Moriokaense respectively, whilst the remaining one could not be identified. This study observed the prevalence of bovine TB among cattle from two farms in Ghana as 2.48% and confirms the public health importance of M. africanum as a pathogen in Ghana.
Mostrar más [+] Menos [-]Spatial and temporal distribution of foot-and-mouth disease virus in the eastern zone of Tanzania
2014
Julius Joseph | Christopher J. Kasanga | Mmeta Yongolo | Chanasa Mpelumbe-Ngeleja | Raphael Sallu | Mathias Mkama | Joseph Masambu
The changing landscape of rabies epidemiology and control
2014
Sarah Cleaveland | Hawthorne Beyer | Katie Hampson | Daniel Haydon | Felix Lankester | Tiziana Lembo | Francois-Xavier Meslin | Michelle Morters | Zacharia Mtema | Maganga Sambo | Sunny Townsend
Over the past 20 years, major progress has been made in our understanding of critical aspects of rabies epidemiology and control. This paper presents results of recent research, highlighting methodological advances that have been applied to burden of disease studies, rabies epidemiological modelling and rabies surveillance. These results contribute new insights and understanding with regard to the epidemiology of rabies and help to counteract misperceptions that currently hamper rabies control efforts in Africa. The conclusion of these analyses is that the elimination of canine rabies in Africa is feasible, even in wildlife-rich areas, through mass vaccination of domestic dogs and without the need for indiscriminate culling to reduce dog population density. Furthermore, the research provides valuable practical insights that support the operational planning and design of dog vaccination campaigns and rabies surveillance measures.
Mostrar más [+] Menos [-]The changing landscape of public health in sub-Saharan Africa: Control and prevention of communicable diseases needs rethinking
2014
Leonard E.G. Mboera | Sayoki G. Mfinanga | Esron D. Karimuribo | Susan F. Rumisha | Calvin Sindato
In sub-Saharan Africa, communicable diseases (CDs) are the leading public health problems and major causes of morbidity and mortality. CDs result in significant individual suffering, disrupting daily life, threatening livelihoods and causing one-third of the years lost to illness or death worldwide. This paper aims to analyse the current strategies in the control and prevention of CDs in sub-Saharan Africa and proposes an ecohealth approach in relation to current changing epidemiological profiles. Whilst in recent years the burden of HIV and AIDS, tuberculosis and malaria have helped to mobilise large amounts of funding and expertise to help address them, many CDs, particularly those affecting the poor, have been neglected. People living in rural areas are also likely to be politically marginalised and living in degraded environments. They often lack assets, knowledge and opportunities to gain access to health care or protect themselves from infections. New diseases are also emerging at unprecedented rates and require attention. Many CDs are rooted in environmental and livelihood conditions and mediated by social and individual determinants. It is now increasingly recognised that a much broader, coordinated and multi-sectoral ecohealth approach is required to address CDs in sub-Saharan Africa. An ecohealth approach has been shown to be more robust in public health interventions than the traditional medical approach. The approach helps to generate an understanding of ecosystem factors that influence the emergence and spread of both old and new diseases, considers temporal and spatial dimensions of disease infection and allows systems thinking. In conclusion, establishing intersectoral and multisectoral linkages is important to facilitate joint efforts to address CDs at the national, district and community levels.
Mostrar más [+] Menos [-]Spatial and temporal distribution of foot-and-mouth disease virus in the lake zone of Tanzania
2014
Joseph M. Genchwere | Christopher J. Kasanga
This study was conducted to determine the spatiotemporal distribution of foot-and-mouth disease (FMD) virus (FMDV) serotypes and evaluate the awareness of livestock keepers about FMD in Tanzania. An observational prospective study involving serological analysis, FMDV antigen detection and questionnaire survey was carried out in the lake zone of Tanzania. Seroprevalence of antibodies to the nonstructural protein 3ABC of FMDV and serotype-specific antigen detection were investigated by using SVANOVIR® FMDV 3ABC-Ab ELISA and indirect-sandwich ELISA (sELISA), respectively, whilst a structured questionnaire was used to evaluate the awareness of livestock keepers about FMD. During the period of 2010–2011, both serum and tissue (foot-and-mouth epithelia) samples were collected from cattle suspected of FMD in 13 districts of the four regions of the lake zone. A total of 107 (80.5%) out of 133 tested serum samples were seropositive to nonstructural protein 3ABC, with at least one sample being positive from all 10 districts screened. Fifteen (53.6%) out of 28 tissue epithelial samples collected from FMD cases in eight districts during the course of this study were positive to serotype O FMDV antigen. Of these eight districts, serotype O FMDV antigens were detected from seven districts and no other serotypes were recovered from animal samples screened. Questionnaire surveys in six districts indicated that livestock keepers in the lake zone were aware of the clinical manifestations (26/29 = 90.0%) and economic impact (23/29 = 79.0%) of FMD in the region. The questionnaire data showed that FMD outbreaks often occurred after rainy seasons (22/29 = 75.9%), with the highest peaks predominantly occurring just after the long rains in May and June, and at the end of the short rains in November and December of each year. The spatial distribution of the FMD cases suggested that serotype O virus exposure was the only widespread cause of the 2010–2011 outbreaks in the lake zone.
Mostrar más [+] Menos [-]Evaluation of medicinal turpentine used for the prevention of bovine babesiosis in southern KwaZulu-Natal and the eastern Free State
2014
Louise J. Biggs | Chris A.P. Carrington | Vinny Naidoo
Medicinal turpentine has been used extensively in the eastern Free State and KwaZulu-Natal provinces of South Africa with reportedly excellent results. It is believed that it is able to prevent and treat babesiosis (redwater) in cattle. Redwater is an often-fatal disease in cattle and results in losses of large numbers every year in South Africa. This study was initiated in an attempt to investigate the validity of the use of the turpentine as a medicinal agent. Using a semi in vitro screening assay, Babesia caballi grown in primary equine erythrocytes was exposed to various concentrations of turpentine in comparison to diminazene and imidocarb. The turpentine had no parasiticidal effect following direct exposure. During the recovery phase, the previously exposed parasites appeared to grow more slowly than the controls. In comparison, diminazene and imidocarb were 100% effective in killing the parasites. In a subsequent tolerance study in adult cattle (n = 6) at 1x (2 mL), 3x and 5x the recommended dose, the product was non-toxic. Irritation was noted at the injection site with the higher dose. The only major finding on clinical pathology was a general increase in globulins, without a concurrent change in native babesia antibody titres. It was concluded that it is unlikely that medicinal turpentine is an effective treatment against babesiosis.
Mostrar más [+] Menos [-]Virulence of <i>Trypanosoma congolense</i> strains isolated from cattle and African buffaloes (<i>Syncerus caffer</i>) in KwaZulu-Natal, South Africa
2014
Makhosazana Y. Motloang | Justin Masumu | Ben J. Mans | Abdalla A. Latif
Trypanosoma congolense and Trypanosoma vivax are major species that infect cattle in north-eastern KwaZulu-Natal (KZN), South Africa. Of the two genetically distinct types of T. congolense, Savannah and Kilifi sub-groups, isolated from cattle and tsetse flies in KZN, the former is more prevalent and thought to be responsible for African animal trypanosomosis outbreaks in cattle. Furthermore, variation in pathogenicity within the Savannah sub-group is ascribed to strain differences and seems to be related to geographical locations. The objective of the present study was to compare the virulence of T. congolense strains isolated from African buffaloes (Syncerus caffer) inside Hluhluwe-iMfolozi Park, and from cattle on farms near wildlife parks (< 5 km), to isolates from cattle kept away (> 10 km) from parks. To obtain T. congolense isolates, blood of known parasitologically positive cattle or cattle symptomatically suspect with trypanosomosis, as well as isolates from buffaloes kept inside Hluhluwe-iMfolozi Park were passaged in inbred BALB/c mice. A total of 26 T. congolense isolates were obtained: 5 from buffaloes, 13 from cattle kept near parks and 8 from cattle distant from parks. Molecular characterisation revealed 80% and 20% of isolates to belong to T. congolense Savannah and Kilifi, respectively. To compare virulence, each isolate was inoculated into a group of six mice. No statistical differences were observed in the mean pre-patent period, maximum parasitaemia or drop in packed cell volume (PCV). Significant differences were found in days after infection for the drop in PCV, the patent period and the survival time. These differences were used to categorise the isolates as being of high, moderate or low virulence. Based on the virulence, 12 of 26 (46%) isolates were classified as highly virulent and 27% each as either of moderate or of low virulence. Whilst 11 of 12 high virulent strains were from buffaloes or cattle near the park, only 1 of 7 low virulent strains was from these animals. All the Kilifi T. congolense types were less virulent than the Savannah types. These results confirmed the higher virulence of T. congolense Savannah type compared to Kilifi type and indicated the prevalence of highly virulent strains to be higher in wildlife parks and in cattle near the parks than on farms further away. The geographical location of these strains in relation to the wildlife parks in the area was discussed.
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