Taenia taeniaeformis: effectiveness of staining oncospheres is related to both temperature of treatment and molecular weight of dyes utilized     

Chapalamadugu KC  Busboom JR  Nelson ML  Hancock DD  Tang J  Jasmer DP 《Veterinary parasitology》2008,151(2-4):203-211

Methods to determine viability of taeniid oncospheres following treatments with potential lethality have practical application in efforts to control transmission. Here we investigated several methods, in lieu of infectivity studies, to assess oncosphere viability and determine lethal temperature treatment regimens. In the first experiment, a standard treatment to exshell oncospheres with 0.5% hypochlorite was assessed for influence on oncosphere recovery of Taenia taeniaeformis eggs. Recovery of eggs and exshelled oncospheres decreased with increasing time in hypochlorite, which indicated that hypochlorite can damage eggs and oncospheres, translating into potential overestimation of lethality of experimental treatments. Losses in hypochlorite were accentuated when eggs were pretreated at 75 degrees C, but not lower temperatures, including 65 degrees C, indicating a sharp threshhold between 65 degrees C and 75 degrees C where eggs and oncospheres became hypersensitive to subsequent hypochlorite treatment. To further investigate this change in relation to temperature, non-vital (acridine orange, AO) and vital (propidium iodide, PI; trypan blue, TB) dyes were used to assess staining of oncospheres (exshelled or not) under conditions ranging from room temperature up to 95 degrees C. The behaviors of dyes as related to internal staining of oncospheres were described using non-linear regression and a sigmoid four-parametric model to determine the inflection point (T50). Each of the dyes differed significantly in T50 estimates, e.g. AO (69.22+/-0.53), PI (73.89+/-0.52) and TB (79.43+/-0.45). For these dyes, the T50 increased in relation to the increasing molecular weight of the dyes. Collectively, the results suggested that barriers to chemical permeability exist in eggs that breakdown incrementally with increasing temperatures above 65 degrees C. This staining behavior and the likelihood that the temperatures involved are above a lethal threshhold clarify a basic limitation in the use of vital dyes to assess oncosphere viability. The results may be relevant to other Taenia spp.  相似文献   

Clinical chemistry values and tissue enzyme activities in western barred bandicoots (Perameles bougainville)     

Bennett MD  Woolford L  O'Hara AJ  Nicholls PK  Warren KS 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2008,37(2):221-224

BACKGROUND: The western barred bandicoot, Perameles bougainville, is an endangered Australian marsupial species whose survival is threatened by a papillomatosis and carcinomatosis syndrome. Investigations to characterize this syndrome would benefit from species-specific clinical chemistry data. OBJECTIVES: The purpose of this study was to determine plasma biochemical reference values and to determine enzyme activities in various tissues of P. bougainville. METHODS: Heparinized blood samples were collected by jugular venipuncture from 53 clinically healthy bandicoots of both sexes and at 3 geographic locations. Plasma was analyzed for routine clinical chemistry variables using an automated biochemistry analyzer. Tissues obtained following humane euthanasia of 3 bandicoots were analyzed for alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine kinase (CK), alpha-amylase (AML), and gamma-glutamyltransferase (GGT) activities. RESULTS: Significant differences in the results were found for animals based on geographic location and sex; hence, results were expressed as minimum and maximum values. A population reference interval was calculated for AST activity (20-283 U/L). ALT was found mainly in the liver, with lower levels in cardiac and skeletal muscle and kidneys. AST was detectable in many tissues, including the heart, liver, kidneys, and central nervous system; CK was found in skeletal and cardiac muscle and central nervous system; AML was found in the pancreas; and GGT was found mainly in kidneys with lower levels in the intestines and pancreas. CONCLUSIONS: These findings will facilitate the interpretation of clinical chemistry results from P. bougainville and thereby inform population management and clinical decision-making.  相似文献   

What is your diagnosis? Preputial mass in a ferret     

Mark D.G. Pinches  Guy Liebenberg  Mark F Stidworthy 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2008,37(4):443-446

Abstract: A 7‐year‐old neutered male polecat‐type ferret (Mustela putorius furo) was presented for evaluation of a cutaneous mass close to the preputial orifice. Cytologic examination of a fine‐needle aspirate revealed numerous large clumps of amorphous pink mucinous material and numerous large clumps of slightly pleomorphic epithelial cells. The cells were arranged in papillary structures, palisades, and loosely cohesive sheets with a vaguely honeycomb appearance. Occasional acinar formations were also seen. The cells had moderate to large amounts of finely granular gray to gray–blue cytoplasm. The cells were round to wispy and elongated, with indistinct borders. Often, anuclear cytoplasmic clumps were seen free in the background or adjacent to intact cells. Nuclei were round to oval and usually off‐center. Chromatin was finely stippled and contained 1–3 indistinct nucleoli. Anisokaryosis and anisocytosis were moderate. Binucleated cells were noted occasionally. The cytologic features were consistent with a carcinoma of probable apocrine origin. Histopathologic examination supported a diagnosis of secretory apocrine adenocarcinoma of the preputial skin. Secretory apocrine adenocarcinomas of the prepuce are seen relatively frequently in ferrets, although their cytologic appearance has not been described widely. These neoplasms carry a poor prognosis although prompt surgical removal with wide and deep surgical margins and adjunctive radiotherapy may improve survival.  相似文献   

A novel medium devoid of ruminant peptone for high yield growth of Mycoplasma ovipneumoniae     

Patel H  Mackintosh D  Ayling RD  Nicholas RA  Fielder MD 《Veterinary microbiology》2008,127(3-4):309-314

Mycoplasma ovipneumoniae is considered an emerging veterinary pathogen causing pneumonia in sheep and goats worldwide. Currently it has not been possible to define a growth medium that yields the maximum growth of M. ovipneumoniae within a short incubation period. Growth yields of M. ovipneumoniae in Eaton's medium are variable and not as consistently high as those seen with other Mycoplasma spp. This study investigated the ability of different M. ovipneumoniae field strains to grow in various media formulations, where PPLO broth was replaced by a vegetable protein source, and comparisons were made in terms of strain viability in Eaton's medium. Studies were also conducted to determine the optimal carbohydrate source for use in the M. ovipneumoniae medium. Generally, it was found that different strains showed good growth in all media tested, with growth yields at 24h in TSB-1 medium higher than those observed with Eaton's medium. Growth yields reached 10(8) to 10(9)cfu ml(-1) within 24h for particular field strains, with all strains achieving this growth level within 48-72h.  相似文献   

Reef shark declines in remote atolls highlight the need for multi‐faceted conservation action     

Nicholas A. J. Graham  Mark D. Spalding  Charles R. C. Sheppard 《水产资源保护:海洋与淡水生态系统》2010,20(5):543-548

• 1. The decline of large‐bodied predatory species in the oceans is a concern both from a sustainability perspective and because such species can have important ecological roles. Sharks are particularly vulnerable to fishing as their life histories are characterized by late age at maturity, large body size, and low fecundity.
• 2. Substantial shark population declines have been documented for a number of coastal and pelagic systems, with high population abundance limited to a few remote locations. The relative abundance and composition of reef shark populations are assessed from 1975 to 2006 at a remote, largely uninhabited, group of atolls in the central Indian Ocean; the Chagos Archipelago.
• 3. Number of sharks observed per scientific dive declined from a mean of 4.2 in the 1970s to 0.4 in 2006, representing a decline of over 90%. Silvertip sharks displayed an increase in abundance from 1996, whereas blacktip and whitetip reef sharks were rarely encountered in 2006.
• 4. Poaching in the archipelago, is the most likely cause of these declines, highlighted by a number of illegal vessels containing large numbers of sharks arrested since 1996. The data highlight that shark populations, even in remote, otherwise pristine, marine areas, are vulnerable to distant fishing fleets, and a range of strategies will need to be used in concert for their conservation. Copyright © 2010 John Wiley & Sons, Ltd.

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Resistance of Phytophthora porri to metalaxyl     

Thomas Locke  John Scrace  J. Mark Peace 《Pest management science》1997,51(3):371-374

Metalaxyl resistance has been identified in the Phytophthora porri population in the UK. In field experiments the presence of such resistant strains reduced the level of control of leek white tip given by applications of phenylamide-containing fungicides. The level of control achieved by fungicides with alternative modes of action to the phenylamides was not affected. ©1997 SCI  相似文献   

Method for Determining the Rate and Extent of Accelerated Starch Retrogradation     

Mark R. Jacobson  James N. BeMiller 《Cereal Chemistry》1998,75(1):22-29

A method to accelerate and quantitate retrogradation of starch pastes using a freeze-thaw cycle (FTC) process and turbidometric analysis has been developed. Using this method and differential scanning calorimetry (DSC), it was determined that the rate of retrogradation in 2.5% waxy maize pastes was inversely correlated to the rate of freezing, and that the thawing temperature affected perfection of the crystallites in retrograded amylopectin. DSC and X-ray diffraction were used to determine whether the crystallites formed during the FTC process were the same as those formed in starch pastes held isothermally at 4°C. Analysis of retrogradation of pastes of starches from various botanical sources indicated that the method reflects retrogradation in higher concentration pastes. Retrogradation rates were reduced by the addition of sodium dodecyl sulfate. Microstructures of freeze-thaw processed waxy maize and common corn starch pastes were examined.  相似文献   

Tobacco anionic peroxidase often increases resistance to insects in different dicotyledonous species     

Patrick F Dowd  L Mark Lagrimini  Daniel A Herms 《Pest management science》1999,55(6):633-634

Different species and strains of tobacco (Nicotiana spp), tomato (Lycopersicon esculentum) and sweetgum (Liquidambar styraciflua) that had total peroxidase activity enhanced by a few- to over 100-fold through the expression of a tobacco anionic peroxidase gene driven by a cauliflower mosaic promoter were compared with wild-type plants for resistance to relevant insects. Reduced levels of feeding were generally noticed for leaves, stems and fruit, but the age of tissues and insects influenced the response. Enhanced resistance to Helicoverpa zea and Manduca sexta were noted for tobacco and tomato, and resistance to Hyphantria cunea and Lymantria dispar were noted for sweetgum. In several cases increased mortality and/or reduced growth rates were noted for the high-peroxidase plants. Although many modes of action are possible, indirect comparisons and gravitational nutritional studies suggest peroxidase-enhanced rates of production of compounds toxic to the insects are the most important.  相似文献   

Verbena × hybrida flower volatiles attractive to Western flower thrips,Frankliniella occidentalis     

Antony M Hooper  Jude A Bennison  Mark C Luszniak  John A Pickett  Eleanor M Pow  Lester J Wadhams 《Pest management science》1999,55(6):660-662

Western flower thrips (WFT) are attracted to three flowering verbena cultivars. The volatile components of these cultivars contain different enantiomers of linalool oxide which have been synthesised and one shown to be attractive to WFT.  相似文献   

Impacts of the COVID-19 pandemic on the dairy industry: Lessons from China and the United States and policy implications          下载免费PDF全文

Qingbin WANG  LIU Chang-quan  ZHAO Yuan-feng  Anthony KITSOS  Mark CANNELLA  WANG Shu-kun  HAN Lei 《农业科学学报》2020,19(12):2903-2915

The purposes of this study are to assess the COVID-19 pandemic's impacts on the dairy industries in China and the United States and to derive policy recommendations for enhancing the diary industries' resilience to pandemics and other market shocks. Specifically, data from the two nations are used to analyze and compare the mechanisms through which the pandemic has affected their dairy industries and to discuss potential lessons from their experiences. The findings suggest that this pandemic has heavily affected the dairy industries in both China and the United States through similar mechanisms, such as decreased farmgate milk prices, disruption and difficulties of moving milk within the supply chains, worker shortages, increased production costs, and lack of operating capital. There were also significant differences in the affecting mechanisms between the two nations, including transportation difficulties from widespread road closures and significant reduction in holiday sales of dairy products in China, and the shutdown of many dairy processors in the United States due to the closing of schools, restaurants, and hotels. While government financial reliefs are highly needed to help many dairy farms and processors survive this pandemic in the short term, the dairy industries and governments need to work together to develop long-term strategies and policies to balance the industries' efficiency and flexibility, product specialization and diversification, supply chain integration and local food systems, and market mechanisms and policy regulations and interventions.  相似文献