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Several rapid extraction methods were evaluated for use with a monoclonal antibody-based competitive inhibition ELISA (cELISA) to detect sulfadimethoxine (SDM) in chicken liver tissue. These methods included extraction of the samples with (1) aqueous buffer with or without ultrafiltration, (2) acetonitrile/water, (3) methanol/water, or (4) acetone. The organic extraction methods were evaluated with or without solvent evaporation prior to dilution into assay buffer for the cELISA. The aqueous-based extraction methods were compatible with the cELISA. However, of the organic extraction methods, only the acetone liver extract with solvent evaporation prior to analysis was compatible with the cELISA. The cELISA method coupled to aqueous- or acetone-based sample extraction as well as an HPLC method was evaluated for the analysis of chicken liver tissues fortified with SDM at levels from 0.2 to 0.025 ppm. Mean SDM recoveries for the HPLC method and for the cELISA method using samples prepared by aqueous extraction, aqueous extraction and ultrafiltration, or acetone extraction, evaporation, and reconstitution were 68.9, 95.7, 60.1, and 52.5%, respectively. For the analysis of samples obtained from an SDM incurred residue study, HPLC and cELISA analysis of the same organic extract gave results that were highly correlated (R(2) = 0.976; p < 0.0001). However, results obtained from the analysis of aqueous extracts by cELISA did not correlate well with those obtained by HPLC (R(2) = 0.61, p > 0. 0006). This was attributed to the coextraction of cross-reactive SDM-related residues that were not quantified by the HPLC method. The presence of these residues should be considered during data interpretation when ELISA methods coupled with rapid aqueous extraction of samples are used in SDM residue monitoring programs.

Four fluoroquinolones were analyzed in fortified chicken liver using an automated, on-line immunoaffinity extraction method. The fluoroquinolones were extracted from the liver matrix using an immunoaffinity capture column containing anti-sarafloxacin antibodies covalently cross-linked to protein G. After interfering liver matrix components had been washed away, the captured fluoroquinolones were automatically eluted directly onto a reversed phase column. Liquid chromatographic analyses were performed by isocratic elution using 2% acetic acid/acetonitrile (85:15) as the mobile phase and an Inertsil phenyl column with fluorescence detection at excitation and emission wavelengths of 280 and 444 nm, respectively. No significant interferences from the sample matrix were observed, indicating good selectivity with the immunoaffinity column. Overall recoveries from fortified liver samples (20, 50, and 100 ng/g) ranged between 85.7 and 93.5% with standard deviations of <5%. The limit of quantification for each fluoroquinolone was 1 ng/mL. The limits of detection, based on a signal-to-noise ratio of 5:1, were 0.47, 0.32, 0.87, and 0.53 ng/mL for ciprofloxacin, enrofloxacin, sarafloxacin, and difloxacin, respectively.

An automated, on-line immunoaffinity extraction method was developed for the analysis of 4 fluoroquinolones in milk: ciprofloxacin, difloxacin, enrofloxacin, and sarafloxacin. This method involves analyte extraction using an immunoaffinity capture column containing anti-fluoroquinolone antibodies coupled on-line with reversed-phase column chromatography. Liquid chromatographic analyses were performed by isocratic elution using a mobile phase of 2% acetic acid-acetonitrile (85 + 15) and an Inertsil phenyl column with fluorescence detection at excitation and emission wavelengths of 278 and 444 nm, respectively. No significant interferences from the sample matrix were observed, indicating good selectivity with the immunoaffinity column. Recoveries from fortified raw milk samples (5-50 ppb of each fluoroquinolone) ranged from 72 to 90%, with standard deviations of < or = 8%.

The techniques of gas chromatography-mass spectrometry (GC-MS) and sequential thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) have been utilised to characterise the constituents of tissue-derived or applied organic material from two Pharaonic Egyptian mummies with a view to identifying embalming practices/substances. The results obtained using TD-GC-MS revealed a series of monocarboxylic acids with the C16:0, C18:1 and C18:0 components dominating in both mummies. The thermal desorption products related to cholesterol, i.e., cholesta-3,5,7-triene and cholesta-3,5-diene (only in Khnum Nakht), were detected in both mummies. Khnum Nakht also contained a number of straight chain alkyl amides (C16-C18) and an alkyl nitrile (C18). Other products included the 2,5-diketopiperazine derivative (DKP) of proline-glycine (pro-gly) which was a major component (7.9%) in Khnum Nakht but only a very minor component in Horemkenesi. Py-GC-MS of samples of both specimens yielded a series of alkene/alkane doublets (Horemkenesi C6-C18, Khnum Nakht C6-C24) which dominated their chromatograms. Series of methyl ketones in the C9-C19 chain length range were also present, with C5-C7 cyclic ketones occurring in Horemkenesi only. These ketones are indicative of covalent bond cleavage, probably of polymerised acyl lipids. Nitrogenous products included nitriles (C9-C18) which were significant in both samples, and amides which were only detected in Khnum Nakht. Also present amongst the pyrolysis products were three steroidal hydrocarbons, cholest-(?)-ene, cholesta-3,5,7-triene and cholesta-3,5-diene. High temperature-GC-MS of trimethylsilylated lipid extracts yielded similar monocarboxylic acids to that obtained using TD-GC-MS, while a series of alpha, omega-dicarboxylic acids and a number of mono- and di-hydroxy carboxylic acids not seen in the thermal desorption or pyrolysis GC-MS analyses were significant constituents in both mummy samples. Overall, the use of GC-MS and sequential TD-GC-MS and Py-GC-MS has demonstrated in both mummies the presence of a complex suite of lipids and proteinaceous components whose compositions indicates extensive alteration via oxidative and hydrolytic processes during long-term interment. None of the classical embalming resins was detected but an exogenous origin for at least a proportion of these components cannot be discounted since fats, oils and gelatin have been proposed as embalming agents in mummification. The combined approach of sequential TD- and Py-GC-MS has potential for application to the characterisation of embalming materials in mummies. Most importantly these techniques virtually eliminate any destruction of the mummified bodies thereby allowing the scope of investigations of ancient Egyptian funerary practices to be significantly extended.

We conducted an epidemiological survey of antibiotic resistance in Salmonella recovered from market-age swine at five different Texas farms. These farms, which were visited between October 1997 and June 1998, were completely integrated, farrow-to-finish operations. Samples were taken from the lymph nodes and cecal contents at the time of slaughter. The Salmonella samples that were recovered were sent to the National Veterinary Services Laboratory for serotyping. Antibiotic resistance was determined using the Dispens-O-Disc Susceptibility Test System using 13 different antimicrobial agents that have been utilized in either veterinary medicine, human medicine, or both. Preliminary analysis of the first 183 samples out of approximately 400 Salmonella samples recovered indicated that 183 (100%) of the Salmonella samples were resistant to penicillin G, and 122 (66.7%) were resistent to chlortetracycline. Six (3.3%) were resistant to four antibiotics (chlortetracycline, penicillin G, streptomycin, and sulfisoxazole), and 25 (13.7%) were resistant to three antibiotics (chlortetracycline, penicillin G, and either streptomycin, sulfisoxazole, or ampicillin). Variation was seen between serotypes, with four out of five S. agona samples (80.0%) and two out of eight S. derby samples (25.0%) resistant to four antibiotics. Variation in antibiotic resistance also was seen between farms. There is an increasing concern about the prevalent usage of antibiotics in medicine and agriculture and the relationship this may have on emerging microbial resistance patterns; therefore, continued surveillance on antibiotic resistance in animal production is warranted.

Experiments were conducted to determine the efficacy of three inorganic sorbents, S1, S2, and S3, to reduce the toxicity of aflatoxins (AF) and T-2 toxin in male broiler chickens from day of hatch to 21 d of age. The compounds had been reported to bind to AF and T-2 toxin in vitro. S1 and S2 were the same basic compound that had been stored for different lengths of time following activation. In Experiments 1, 2, and 3, the appropriate diets were produced to contain no mycotoxins, the specific adsorbent at 0.5% of diet, AF alone at 5 mg/kg of diet, T-2 alone at 8 mg/kg of diet, AF at 5 mg/kg of diet plus the specific sorbent at 0.5% of diet, or T-2 at 8 mg/kg of diet plus the specific sorbent at 0.5% of diet. The specific sorbents used were: 1) Experiment 1, S1; 2) Experiment 2, S1 and S2; and 3) Experiment 3, S3. In Experiments 1 and 3, S1 and S3, respectively, showed no protection against AF or T-2 toxin as measured by BW gain, when compared to AF alone group. In Experiment 2, S1 showed no protection; however S2 reduced the effects of AF on BW gain by 25% as compared to AF alone diet. The data demonstrate that under the conditions of our experiment: 1) one of the sorbents provided some protection against aflatoxicosis; 2) there was variability in protection against aflatoxicosis between two different samples of the same sorbent that had been stored for different lengths of time following activation; 3) protection by the sorbents against the effects of T-2 toxin was not observed.

Experiments were conducted to determine the ability of a hydrated sodium calcium aluminosilicate (T-Bind) sorbent to reduce the toxicity of aflatoxins (AF) or T-2 toxin in male broiler chickens from day of hatch to 21 d of age. In Experiment 1, the sorbent was added at 0.250 or 0.375% to diets containing AF at 5 or T-2 toxin at 8 mg/kg of diet. When compared with controls, AF reduced BW gain by 27% and T-2 toxin reduced BW gain by 17%. The addition of the sorbent at 0.250 or 0.375%, in the absence of added mycotoxins, did not alter the performance of the chicks. The sorbent reduced the toxic effects of 5 mg AF/kg of diet on BW gain by 43% but did not significantly diminish the toxic effects of 8 mg T-2 toxin/kg of diet. The decreased efficiency of feed utilization and the increased relative organ weights caused by AF were significantly diminished to differing degrees by the sorbent. Oral lesions caused by T-2 toxin were not affected by the sorbent. In Experiment 2, the sorbent was added at 0.80% to a diet containing 8 mg T-2 toxin/kg of diet. The sorbent did not diminish the toxic effects of T-2 toxin when added at 0.80% of the diet. These data demonstrate that this specific sorbent can provide protection against the toxicity of AF, but not T-2 toxin, in young broiler chicks.

Previous studies have demonstrated that a novel source of ozone gas (O3) maybe used to chemically degrade numerous mycotoxins, including aflatoxin (AF) B1. Subsequent in vitro analyses demonstrated detoxification of AFB1, suggesting a potential method of remediate AF-contaminated grain. The objective of this study was to evaluate the capability of electrochemically produced ozone to degrade AFB1 in naturally contaminated whole kernel corn and confirm detoxification in turkey poults. Corn was procured from the southern coastal areas of Texas and HPLC revealed 1,220 +/- 73.3 ppb AFB1. Control and contaminated corn were treated for 92 h with O3 at 200 mg/min in 30 kg batches; greater than 95% reduction of AFB1 in contaminated corn was achieved. One-day-old female turkey poults were fed 1) control corn, 2) control corn + O3, 3) AFB1 corn, or 4) AFB1 corn + O3 mixed in rations (46% by wt.) and consumed ad libitum for 3 wk. When compared with controls, turkeys fed AFB1 corn had reduced body weight gain and relative liver weight, whereas turkeys fed control corn + O3 or AFB1 corn + O3 did not differ from controls. Furthermore, alterations in the majority of relative organ weight, liver discoloration, serum enzyme activity, hematological parameters, and blood chemistry caused by AFB1 were eliminated (no difference from controls) by treatment with O3. These data demonstrate that treatment of contaminated corn with electrochemically produced O3 provided protection against AFB1 in young turkey poults. It is important to note that treatment of control corn with O3 did not alter the performance of the turkey poults.

Ceftiofur, a recently introduced antibiotic of the beta-lactam group, is rapidly converted to both free and protein-bound metabolites when administered by the prescribed procedure, intramuscular injection. Free metabolites retain antimicrobial activity and may be detected by antibiotic-screening tests based on antimicrobial activity. It is thus desirable to distinguish ceftiofur metabolites from other antibiotics. A multiresidue procedure for beta-lactams in milk was adapted for determination of free ceftiofur metabolites by collecting appropriate liquid chromatographic fractions during cleanup. Analysis of tissues from treated animals showed that the principal free metabolite was the desfuroylceftiofurcysteine conjugate.

A model for experimental and natural infection of early weaned pigs with Salmonella choleraesuis, the aetiologic agent of swine paratyphoid, has been developed. An oral dose of 10(8) colony forming units (cfu) of S choleraesuis caused 100 per cent infection of 10 pigs inoculated, as indicated by recovery of the challenge organism from ileocolic lymph nodes collected at necropsy seven days post challenge. Seven of the pigs were observed shedding S choleraesuis at least once post S choleraesuis challenge. The cumulative incidence of shedding was 30 per cent and was sufficient to infect four of 10 pigs exposed naturally. Oral challenges with less than 10(8) cfu S choleraesuis were less effective in infecting early weaned pigs and did not result in natural transmission.

The effects of feeding diets containing 100 mg moniliformin (M)/kg of feed from culture material and 16 mg deoxynivalenol (DON)/kg of feed from naturally contaminated wheat were evaluated in growing broiler chicks from 1 day to 21 days of age. Body weight (BW), body-weight gain, and feed consumption were decreased by feeding M and M plus DON diets. Relative heart weight was increased by the M diet, whereas relative weights of proventriculus, gizzard, and heart were increased by the M plus DON diet. The M diet increased alanine transferase and aspartate transaminase activities and creatinine concentration and decreased mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration (MCHC). The M and DON diet decreased glucose, hemoglobin, and MCHC. Histopathological lesions from the M diet were limited to the kidney and consisted of extensive renal tubular epithelial degeneration plus luminal mineralization. A moderation of the severity of lesions was seen in the tissues of the M plus DON-fed chicks, consisting of generally mild tubular epithelial degeneration. None of the parameters measured were affected by the DON diet. Results indicate additive or less-than-additive toxicity for most parameters when chicks were fed diets containing 100 mg M plus 16 mg DON/kg of feed. Although the concentration of M in this study was high compared with that reported for feedstuffs, additional information on the occurrence and toxicity of M will need to be collected in order to assess the importance of M to the poultry industry.

Patients with supranuclear and internuclear ocular motility disorders may have nystagmus and oscillopsia, or need to adopt an abnormal head posture to either fixate or maintain binocularity. Many have a cosmetically unsatisfactory appearance. In addition, because of lesions involving ocular motor nuclei or nerve fascicles, double vision is also a common problem. The usual management of these patients is symptomatic with occlusion or prisms. We report on 11 patients who underwent extraocular muscle surgery with the aim of reducing symptoms and restoring or improving binocular single vision. Three patients had bilateral internuclear ophthalmoplegia with exotropia, 3 had dorsal midbrain syndrome, 2 had residual upgaze palsies after cerebral vascular accidents, 2 had oculopalatal myoclonus and one skew deviation. After surgery, symptoms, visual function and cosmesis improved in nearly all patients. We recommend that surgery should be considered more readily in the rehabilitation of these patients.

Purtscher's retinopathy presents to the clinician as loss of vision in a patient with a history of a possible precipitating event such as recent major trauma, pancreatitis, childbirth or renal failure. The ophthalmological picture is one of ischaemia at the posterior pole with white patches of oedema and haemorrhages concentrated around the optic disc. The most probable pathological cause is embolisation of the peripapillary terminal arterioles supplying the superficial peripapillary capillary net. The nature of the embolic particles remains uncertain. Complement-mediated aggregates, fat, air, fibrin clots and platelet clumps may all be involved in what is most likely to be a multifactorial process. There is at present no recognised treatment for the condition.

The treatment of acute angle closure glaucoma has been influenced by the development of the YAG laser and its ability to perform iridotomies as an outpatient procedure. In this retrospective study the results of YAG iridotomy were compared with surgical peripheral iridectomy. When compared with surgical peripheral iridectomy patients, YAG iridotomy patients were at greater risk of proceeding to further surgery, with this risk being significantly associated with increasing duration of attack. The authors suggest that in selected cases, surgical iridectomy should be given consideration as a primary procedure.

Ibopamine is a dopaminergic mydriatic of proven use for fundoscopy. This double-blind prospective trial assessed its efficacy and safety as a preoperative mydriatic agent. 105 patients undergoing extracapsular cataract surgery were randomly allocated to receive Ibopamine 1%, Ibopamine 1% with Cyclopentolate 1%, or the control Phenylephrine 10% with Cyclopentolate 1%. Ibopamine alone achieved good mydriasis prior to anaesthesia, but this was not maintained intraoperatively. Cyclopentolate combined with Ibopamine, produced consistently greater mydriasis than when combined with Phenylephrine, but the difference became less marked as surgery continued. Analysis in relation to the stage of surgery showed that the greatest stimulus to miosis occurred during expression of the nucleus. Pulse rate and blood pressure in the 51 local anaesthetic cases showed no significant difference between the treatment groups, and there was no significant variation from baseline. The incidence of local side effects was similar in the three groups, and there were no systemic symptoms attributable to the drops. In conclusion, Ibopamine is a safe and effective mydriatic agent for cataract surgery, when used in combination with Cyclopentolate.

Laser panretinal photocoagulation (PRP) reduces visual loss in proliferative diabetic retinopathy but decreases peripheral retinal function. The Driver and Vehicle Licensing Centre (DVLC) states that when a patient volunteers that he or she has had photocoagulation, a questionnaire will then be sent to the patient's diabetic physician who can refer the patient for formal field testing. Of 30 patients who had PRP, 15 failed DVLC visual field regulations using the Esterman binocular field test on the Humphrey field analyser. The failures were more likely to have had treatment with a xenon laser, but there was no difference between the groups as regards age, number of burns or whether an argon or diode laser was used. The patients who failed were more likely to be hypertensive (p = 0.04). Two patients with unilateral PRP could not meet the driving regulations because of other field defects. Diabetes itself causes field defects, and therefore even with small amounts of laser, formal field testing may be necessary.

The effect of the level of training on house staff's abilities to accurately diagnose acute ischemic heart disease (AIHD) and admit patients presenting in an emergency room was assessed. A validated mathematical instrument, which calculates patients' probabilities of AIHD, was used to retrospectively stratify admitted patients. Sensitivity rates of house staff were similar for patients with high probabilities (greater than or equal to 40%) of AIHD (ns). When probabilities of AIHD were low (less than 40%), junior residents correctly admitted a significantly higher proportion of patients with confirmed AIHD than did interns (86% versus 63%, respectively; p less than 0.06). Specificity was unaffected by the level of house staff training for patients with probabilities of AIHD less than 40% (ns). In the high probability group of patients, the interns' specificity rate (54%) was significantly better than the 20% for junior residents (p less than 0.03); however, when clinical severity was controlled for, no differences by level of training were found.