Prominent publications by Barry L Smith

KOL Index score: 9886

AIMS: To study the increase in phylloerythrin concentration in plasma and the disposition of phylloerythrin in skin and other tissues of sheep in which the hepatogenous photosensitisation,facial eczema, had been experimentally induced by dosing with the mycotoxin, sporidesmin. Spectroscopic differences between plasma and skin measurements of animals kept inside and outside after dosing were also studied in order to establish whether phylloerythrin undergoes photodegradation when exposed ...

Also Ranks for: Facial Eczema |  phylloerythrin plasma |  healthy sheep |  emission spectra |  exposed sunlight
KOL Index score: 8581

Ryegrass staggers is a seasonal mycotoxicosis of grazing livestock characterised by tremors, in coordination and a staggering gait almost unaccompanied by physical lesions. Deaths occur only as a consequence of accident or starvation. Outbreaks, in summer and autumn, occur only on pasture in which endophyte (Neotyphodium lolii)-infected perennial ryegrass (Lolium perenne) predominates and usually on which animals are grazed intensively. Animals recover when moved to a different type of ...

Also Ranks for: Ryegrass Staggers |  lolium perenne |  neotyphodium lolii |  secondary metabolites |  endophyte infection
KOL Index score: 8565

The mycotoxic tremorgens penitrem, paxilline and lolitrem B had profound effects on electromyographic (EMG) activity of smooth muscle of the reticulorumen in conscious sheep, with a similar time course of action to their respective characteristic effects on the induction (1 to 2, 15 to 20 and 20 to 30 minutes) and the duration (1 to 2, 1 to 2 and 8 to 12 hours) of tremoring. Responses to penitrem revealed a greater sensitivity of smooth muscle than skeletal muscle. Effects included an ...

Also Ranks for: Electromyographic Activity |  tremorgenic mycotoxins |  smooth muscle |  penitrem lolitrem |  conscious sheep
KOL Index score: 7849

It has previously been shown that rats pre-treated with butylated hydroxyanisole (BHA), a well-known inducer of the enzyme DT-diaphorase, are protected against the toxic effects of 2-methyl-1,4-naphthoquinone but are made more susceptible to the harmful action of 2-hydroxy-1,4-naphthoquinone. In the present experiments, the effects of BHA have been compared with those of other inducers of DT-diaphorase. Rats were dosed with BHA, butylated hydroxytoluene (BHT), ethoxyquin (EQ), dimethyl ...

Also Ranks for: Inducers Dtdiaphorase |  naphthoquinone rats |  enzyme diaphorase |  2 hydroxy14 |  butylated hydroxyanisole
KOL Index score: 7727

The electromyographic (EMG) activity of skeletal muscle was investigated as a method of recording the tremorgenic activity of the mycotoxins penitrem, paxilline and lolitrem B in sheep. EMG recordings were made concurrently from the abomasal antrum and duodenum to study the effects of these tremorgens on smooth muscle of the gut. Penitrem (2.2 to 7.5 micrograms kg-1) induced mild to moderate tremors within 15 to 20 minutes of injection which lasted for two to four hours. Paxilline (0.66 ...

Also Ranks for: Smooth Muscle |  electromyographic activity |  paxilline lolitrem |  inhibitory effects |  indole alkaloids
KOL Index score: 7563

The enzyme DT-diaphorase catalyses the 2-electron reduction of quinones. This reaction may facilitate the detoxification of such compounds, since the hydroquinone so formed can be converted into non-toxic conjugates. There is evidence for the involvement of DT-diaphorase in the detoxification of menadione (2-methyl-1,4-naphthoquinone) in a wide range of cells and tissues in vitro, but no information is available on the possible influence of this enzyme on the harmful effects of menadione ...

Also Ranks for: Butylated Hydroxyanisole |  haemolytic anaemia |  enzyme diaphorase |  harmful effects |  dehydrogenase quinone
KOL Index score: 6735

OBJECTIVE: To compare the effects of the ergot alkaloid ergovaline with effects of ergotamine on blood pressure, heart rate, respiratory rate, and body temperature in conscious sheep.

ANIMALS: 3 sheep with indwelling arterial catheters.

PROCEDURE: Ergotamine and ergovaline were injected IV (20 nmol/kg), and their effects on arterial blood pressure, heart rate, respiratory rate and pattern, body temperature, and skeletal muscle electromyographic activity were compared with control values ...

Also Ranks for: Effects Ergotamine |  heart rate |  sheep ergovaline |  blood pressure |  body temperature
KOL Index score: 6568

It has previously been shown that rats pre-treated with butylated hydroxyanisole (BHA), a well-known inducer of the enzyme DT-diaphorase, are protected against the harmful effects of 2-methyl-1,4-naphthoquinone. This is consistent with a role for diaphorase in the detoxification of this quinone, but it is not known if increased tissue levels of this enzyme give protection against other naphthoquinone derivatives. In the present study, rats were dosed with BHA and then challenged with a ...

Also Ranks for: Butylated Hydroxyanisole |  rats bha |  enzyme diaphorase |  quinone naphthoquinones |  2 hydroxy14
KOL Index score: 6404

OBJECTIVE: To investigate the effects of IV administration of ergotamine and ergovaline and intraruminal administration of ergotamine on electromyographic (EMG) activity of reticuloruminal smooth muscle in conscious sheep.

ANIMALS: 3 sheep with indwelling electrodes in the musculature of the reticulum and rumen.

PROCEDURE: In a crossover design study, reticuloruminal motility before and after IV administration of ergotamine (5, 10, 20, and 40 nmol/kg) or ergovaline (2.5, 5, and 10 ...

Also Ranks for: Smooth Muscle |  rumen sheep |  effects ergotamine |  vasoconstrictor agents |  administration 40
KOL Index score: 5766

Facial eczema (pithomycotoxicosis), a photosensitisation of ruminants grazing pasture, has been known in New Zealand for over 100 years, but its cause, a toxin produced by a largely saprophytic fungus, Pithomyces chartarum, growing on litter at the base of pasture and sporing profusely under warm moist conditions in late summer and autumn, was found only 50 years ago. As the fungus spores it produces the toxin sporidesmin which, when eaten by sheep, cattle, goats or deer, causes liver ...

Also Ranks for: Facial Eczema |  new zealand |  toxin sporidesmin |  pithomyces chartarum |  bile ducts
KOL Index score: 5698

Bracken fern (Pteridium esculentum) was harvested from two sites LB and TB one of which (TB) was on a central North Island New Zealand farm where bovine enzootic haematuria (BEH) was known to occur. The fern was dried, ground and incorporated (25% w/w) into a pelleted diet and fed to female rats for a total of 162 days. Fifteen weeks later when the rats were autopsied it was found that numerous tumours, mainly of the ileum and urinary bladder were present in the animals fed the bracken ...

Also Ranks for: New Zealand |  pteridium esculentum |  bracken fern |  bovine enzootic haematuria |  urinary bladder
KOL Index score: 5545

Mycotoxicoses are some of the most important diseases of animals grazing pastures in New Zealand, especially in northern areas where the disease, facial eczema, occurs. New Zealand scientists have led the world in research on facial eczema and endophyte-related diseases associated with tremoring. Facial eczema (pithomycotoxicosis) was one of the first mycotoxicoses to be studied systematically and successful methods for its control now exist. Toxicity is caused by the concentration of ...

Also Ranks for: New Zealand |  grazing animals |  facial eczema |  fusarium spp |  sheep cattle
KOL Index score: 5330

Bracken fern (Pteridium spp.) causes cancer of the oesophagus and the urinary bladder in cattle and sheep. Ptaquiloside (PT) is believed to be the carcinogenic principle which alkylates DNA when activated to its unstable dienone form (APT) under alkaline conditions. In this report we present evidence for the presence of PT-DNA adducts in the ileum of bracken fem-fed calves using the 32P-postlabelling assay. H-ras mutations were also observed in the ileum using single strand conformation ...

Also Ranks for: Bracken Fern Carcinogenesis |  urinary bladder |  dna alkylation |  alkaline conditions |  plants toxic

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Barry L Smith:Expert Impact

Concepts for whichBarry L Smithhas direct influence:New zealand,  Facial eczema,  Bracken fern,  Ryegrass staggers,  Body temperature,  Butylated hydroxyanisole,  Electromyographic activity.

Barry L Smith:KOL impact

Concepts related to the work of other authors for whichfor which Barry L Smith has influence:New zealand,  Facial eczema,  Pteridium aquilinum,  Bracken fern,  Ergot alkaloids,  Urinary bladder,  Perennial ryegrass.



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AgResearch, Ruakura Agricultural Research Centre, Private Bag 3123, Hamilton, New Zealand | AgResearch, Ruakura Agricultural Research Centre, Private Bag 3123, Hamilton 2001, New Zealand | Toxicology, AgResearch, Ruakura Research Centre, Hamilton, Ne