Citrinin mycotoxicosis in the rabbit.

In three trials, single or multiple doses of citrinin dissolved in 0.5 N-NaOH and adjusted to neutral pH with HCl were given to rabbits by either the oral or intraperitoneal route. The 72-hr LD50 was 50 mg/kg body weight by intraperitoneal administration and 134 mg/kg by the oral route. The primary clinical sign in rabbits receiving a single oral dose of 125-150 mg citrinin/kg was fluid diarrhoea commencing 8 hr after dosing. Pathological alterations were generally confined to the kidney and consisted of degeneration and necrosis of proximal convoluted tubules and straight segments. In rabbits given a single oral dose of citrinin (130 mg/kg) the earliest histopathological change, seen 8 hr after dosing, was cytoplasmic vacuolation of tubular epithelial cells. Rabbits given a single oral dose of 120 mg citrinin/kg had regeneration of renal tubular epithelium accompanied by slight tubular cell necrosis when examined 7 days after dosing. Rabbits given multiple sublethal doses of citrinin (33.5 or 77 mg/kg daily for 7 days) had renal alterations of mild tubular degeneration and necrosis, and tubular regeneration.

Citrinin mycotoxicosis in the rabbit: clinicopathological alterations.

Citrinin, a nephrotoxic mycotoxin, was dissolved in 0.5 N-NaOH neutralized with HCl and given in a single oral dose of 120 mg/kg (Trial I) or 80 or 100 mg/kg (Trial II) to male New Zealand white rabbits weighing 2.0-2.7 kg. In Trial I, sequential measurements of clinicopathological parameters were made over a 24-hr period. Azotaemia and metabolic acidosis with haemoconcentration and hypokalaemia developed within 4-12 hr. In Trial II, clinicopathological and urinary parameters were measured daily for 7 days. Increased blood urea nitrogen and serum-creatine levels and decreased creatinine clearance indicated renal failure; these values were most abnormal on days 2-4, returning to normal or near normal by day 7 in rabbits that survived. Urine analysis indicated tubular dysfunction and necrosis with glucosuria, isosthenuria and cylindruria; most urinary parameters were normal by day 7.

Cyclical micromovement and fracture healing.

We studied 56 patients with fractures of the tibial shaft in a multicentre prospective randomised trial of three methods of external fixation. Group I was treated with a fixator which was unlocked at 4 to 6 weeks to allow free axial compression (axial dynamisation) with weight-bearing. Group II was treated with a fixator that was similarly unlocked at 4 to 6 weeks but included a small silicone spring which on weight-bearing could be compressed by up to 2 mm. this spring returns to its original length on cessation of weight-bearing thus allowing cycles of motion of up to 2 mm. Group III had a spring fixator like group II, but it was unlocked from the start to allow cyclical micromovement as soon as weight-bearing began. Fracture healing was monitored by the measurement of fracture stiffness. We defined healing as achieving a stiffness of 15 Nm per degree. The mean time was 14.1 weeks in group I, 15.9 weeks in group II, and 19.3 weeks in group III. The difference between groups was statistically significant (p = 0.004). The 95% confidence intervals for the average delay in healing with early cyclical micromovement (group III) as compared with later axial dynamisation (group I) was 1.8 to 8.7 weeks. The healing time in patients whose cyclical micromovement was delayed for 4 to 6 weeks (group II) was between these two extremes, but the differences from either of the other groups could have been due to patient selection. In the patients who completed the full trial, there were pin-track infections in over 60% of those in the cyclical micromovement groups compared with 20% in the axial dynamisation group (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Toxicity of Fusarium moniliforme var. subglutinans for chicks, ducklings, and turkey poults.

Corn-based diets contaminated with various concentrations of a moniliformin-producing isolate of Fusarium moniliforme var. subglutinans were found to be lethal for chicks, ducklings, and turkey poults. Ducklings appeared to be the most sensitive to the lethal effects of the toxic feed. Gross lesions were ascites, hydropericardium, and myocardial pallor. Microscopic lesions were limited to the heart and liver, and they consisted of degeneration and necrosis of the myocardium and degeneration of hepatocytes. Cardiotoxicosis was the apparent cause of death.

Influence of prepubertal consumption of zearalenone on sexual development of boars.

Littermate pairs of crossbred boars were fed 40 ppm zearalenone from 14 to 18 weeks of age, and the effects on reproductive development were examined. Compared to controls, boars fed zearalenone subsequently had reduced libido scores (P greater than.05), and fewer treated animals exhibited mating behavior. Plasma concentrations of testosterone were depressed (P greater than .05) during consumption of zearalenone. Zearalenone did not significantly affect age at which sperm were first voided in the urine (P greater than .25). Body weight and testicular size were not affected by zearalenone. At 36 weeks of age, testicular weight, epididymal weight, spermatid numbers, motility of cauda epididymal sperm and testicular morphology did not differ between control boars and those that had consumed zearalenone.

Effect of Fusarium roseum corn culture containing zearalenone on early pregnancy in swine.

A corn culture of Fusarium roseum was added to a standard corn-soybean swine gestation ration. Low, middle, and high dosage mixed feeds contained 7, 38, and 64 mg of zearalenone/kg of feed (7, 38, and 64 ppm) and 0.5, 2.5, and 4.5 mg of deoxynivalenol/kg, respectively. Control feed was the standard ration without added F roseum corn culture. Mature gilts were bred by natural service and fed control or F roseum molded feed from 3 to 34 days after breeding. The main effect of the molded feed was an inhibition of fetal development, with decreased numbers of fetuses present in treated animals at slaughter (38 to 43 days after breeding). Normal litters were present in 7 of 8 control animals, in 2 of 4 gilts given the low-dosage feed, in 1 of 4 gilts given the medium dosage, and in 0 of 4 given the high-dosage feed. Corpora lutea were maintained in all treated animals, as evidenced by serum progesterone concentrations. Serum estradiol concentrations were decreased in gilts in the middle- and high-dosage groups. The genital system of the gilts fed low- and middle-dosage feeds had a gross and microscopic appearance similar to that of the pregnant controls and reflected prolonged progesterone stimulation. Morphologic changes in the genital system of the high-dosage group were intermediate between changes induced by progesterone and those induced by estrogen. Clinical signs of hyperestrogenism and partial feed refusal were noticed in only some of the high-dosage group animals.

Effect of Fusarium roseum (Gibberella zea) on pregnancy and the estrous cycle in gilts fed molded corn on days 7-17 post-estrus.

A laboratory produced corn culture of Fusarium roseum (Gibberella zea) was fed as 10% of the total diet to bred and non-bred gilts on days 7-17 postestrus. The corn culture contained both zearalenone and deoxynivalenol by analysis, and caused considerable feed refusal. Although 6 of 10 bred gilts fed the corn culture appeared to be pregnant by ultrasound testing between days 40-50 post-breeding, none of them farrowed. Progesterone analyses indicated that none of the 10 gilts cycled normally during the 20 week observation period. Three maintained high serum progesterone (greater than 10 ng/ml) during the entire period. Progesterone analyses were similar in 5 non-bred gilts fed the corn culture in that none of them cycled normally in 20 weeks. The retention or loss of corpora lutea could not be attributed to levels of luteinizing hormone, as no relationship was found between concentrations of progesterone and luteinizing hormone. This experiment indicates that limited dietary exposure of female swine to Fusarium roseum infected corn can result in embryonic loss and disruption of normal reproductive cycling for an extended length of time.

Ochratoxin A and citrinin induced nephrosis in Beagle dogs. I. Clinical and clinicopathological features.

Ochratoxin A and citrinin, both mycotoxins, were given separately and combined to young Beagle dogs for 14 days. Ochratoxin A, 0.1 and 0.2 mg/kg, was given by capsule, and citrinin, 5 and 10 mg/kg, was dissolved in ethanol and given by intraperitoneal injection. Clinical signs of toxicosis in dogs given 10 mg/kg citrinin and the higher combined doses included anorexia, retching, tenesmus, weight loss, prostration and death. Severity of the clinical disease and mortality were increased when the mycotoxins were combined, which indicated synergism. The clinicopathological abnormalities reflected renal damage, in that glutamic oxaloacetic transaminase and lactic dehydrogenase increased in the urine of the dogs with clinical signs of poisoning. Serum lactic dehydrogenase was increased in dogs given 10 mg/kg citrinin. Cellular and granular casts, ketones, protein and glucose were in the urine of dogs given large doses of citrinin alone or combined with ochratoxin A. Serum concentrations of sodium, potassium and chloride in the dogs given high doses of each group.

Ochratoxin A and citrinin induced nephrosis in Beagle dogs. II. Pathology.

Beagle dogs were given ochratoxin A (0.1 and 0.2 mg/kg) and citrinin (5 and 10 mg/kg) alone and in two dose combinations for 14 days. The gross lesions included focal peritonitis and intestinal intussusceptions in dogs given citrinin. Changes in the kidneys of dogs given ochratoxin A were degeneration and necrosis with desquamation of tubular epithelial cells, primarily in the straight segment of the proximal tubules. Dogs given 10 mg/kg citrin had similar changes in the distal tubules and collecting ducts. Dogs given combined doses of citrinin and ochratoxin A had degeneration and necrosis in proximal and distal tubules, and in thin segments and the collecting ducts; there were desquamated cells and granular casts in the lumina. Dogs given ochratoxin A had necrosis of lymphoid tissues in the spleen, tonsil, thymus, peripheral lymph nodes and lymph nodules of the ileum, colon and rectum. There was ulceration of the mucosa of the intestine in dogs given large combined doses of ochratoxin A and citrinin.

Mycotoxicosis produced in swine by cultural products of an isolate of Aspergillus ochraceus. II. Clinicopathologic changes.

Rice culture of a toxigenic strain of Aspergillus ochraceus was fed at a concentration of 25% to weanling pigs for 10 days. The clinicopathological abnormalities reflected renal damage. Activities of lactic dehydrogenase, glutamic-oxaloacetic transaminase and isocitrate dehydrogenase were increased in the urine but not in the serum. Serum concentrations of urea nitrogen and creatinine were high. Cellular and granular casts, blood, protein, and glucose were in the urine of pigs fed toxic diet. Serum concentrations of K+, Na+ and Cl- were unchanged, but concentrations of these electrolytes were reduced in the urine.

Mycotoxicosis produced in swine by cultural products of an isolate of Aspergillus ochraceus. I. Clinical observations and pathology.

Pigs fed a ration, 25% of which was rice culture, of Aspergillus ochraceus lost weight or failed to gain and became depressed. Some pigs died and most developed subcutaneous edema, hydrothorax, hydroperitoneum, pulmonary atelectasis, edema of the mesentery and perirenal edema. Microscopic lesions in addition to edema were primarily renal and consisted of tubular degeneration and necrosis, hyaline tubular casts, interstitial fibrosis and tubular cell regeneration. The first change found after 3 days was cytoplasmic vacuolation of the convoluted and straight segments of the proximal tubules. Necrotic proximal tubules were found after 4 days and after 9 days degeneration and necrosis involved predominantly proximal tubular segments. Pigs fed a ration, 12.5% of which was rice culture, for 8 weeks did not develop perirenal edema but had firm kidneys. Extensive interstitial fibrosis of the cortical labyrinth was the principal change. Within the fibrous connective tissue, some tubules were necrotic and others were atrophied.

Natural occurrence of deoxynivalenol, 15-acetyl-deoxynivalenol, and zearalenone in refusal factor corn stored since 1972.

Two samples of "refusal factor" corn, one stored frozen in Minnesota and one stored dry in Indiana since 1972 or 1973, were analyzed for the presence of Fusarium spp. and Fusarium toxins. Both samples were from corn refused by swine in Indiana from 1972 to 1973. Sample FS 808 (stored in Indiana) contained 20 ppm of deoxynivalenol (20 micrograms/g), 16 ppm of 15-acetyl-deoxynivalenol, 5 ppm of zearalenone, and 0.2 ppm of alpha-zearalenol. Sample FS 362 (stored in Minnesota) contained 3 ppm of deoxynivalenol, 1 ppm of 15-acetyldeoxynivalenol, and 0.3 ppm of zearalenone. The presence of 15-acetyl-deoxynivalenol is significant because it is the first report of it occurring naturally in refusal factor corn, and it may account in part for the refusal that could not be solely attributed to deoxynivalenol.

Assay for aflatoxin production by the genera Aspergillus and Penicillium.

A total of 260 isolates, including 43 species of Penicillium and 7 species of Aspergillus, were screened for their ability to produce aflatoxin on rice. Chloroform extracts were analyzed by thin-layer chromatography. None of the isolates produced aflatoxin. Certain species of Penicillium produced fluorescent substances that either were similar in R(F) or were of similar color to B and G aflatoxins. These substances were subsequently proved not to be aflatoxin by two-dimensional chromatography, by reaction with iodine fumes, or by both methods.

Zearalenone production by Fusarium species.

One-hundred-and-thirteen isolates of Fusarium were tested for their ability to produce zearalenone on autoclaved corn. They belonged to the following species (number of producers per number tested): F. epispheria, (0/1); F. moniliforme, (0/8); Gibberella fujikuroi, (0/3); F. nivale, (0/7); F. oxysporum, (0/15); F. roseum, (31/51); F. solani, (0/9); F. tricinctum (3/19). The isolates of individual species produced the following amounts of zearalenone per gram of corn: 3 isolates of F. roseum (0.6 to 119 mug), 3 of F. roseum "Culmorum" (1 to 210 mug), 3 of F. roseum "Equiseti" (0.6 to 2.0 mug), F. roseum "Gibbosum" (115 to 175 mug), 21 of F. roseum "Graminearum" (0.2 to 230 mug), and 3 of F. tricinctum (0.2 to 6.0 mug). All isolates of F. roseum "Graminearum" which formed the perithecial stage of G. zeae (G. roseum) produced zearalenone. Production occurred by the wild but not the appressed cultural type. Zearalenone production by F. tricinctum was confirmed by a mouse bioassay.

Emetic and refusal activity of deoxynivalenol to swine.

The minimum emetic dose of deoxynivalenol to swine weighing 9 to 10 kg was 0.05 mg/kg of body weight intraperitoneally and 0.1 to 0.2 mg/kg orally. There was no emesis by undosed pigs consuming vomitus from pigs orally dosed with deoxynivalenol or penned with such pigs without access to vomitus. Analysis by gas-liquid chromatography of a sample of Gibberella zeae-infected corn containing about 25% visually damaged kernels indicated 12 ppm of deoxynivalenol. Deoxynivalenol added to feed reduced feed consumption of 20- to 45-kg pigs, ranging from a 20% decrease with 3.6 ppm to 90% reduction with 40 ppm. Loss in weight was associated with feed refusal. Feed refusal, however, was much greater for naturally infected corn samples than for feeds with equal concentrations of the pure compound added, indicating the involvement of an additional factor(s) in the swine refusal response.