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Biomedical subjects

K L Anderson

Publications and source records attributed to K L Anderson.

At least 91 records · Page 5Linked to original sources
PubMed1993

Determination of ceftiofur and its metabolite desfuroylceftiofur in bovine serum and milk by ion-paired liquid chromatography.

A simple and sensitive liquid chromatographic method has been developed for the simultaneous determination of ceftiofur and its metabolite desfuroylceftiofur in bovine serum and milk. The method involved an ultrafiltration of diluted serum/milk with an equal volume of 50% acetonitrile through a 10,000 dalton molecular mass cut-off filter. Separation of ceftiofur and desfuroylceftiofur from the other serum/milk components was performed by ion-paired (octane and dodecanesulfonate) liquid chromatography using a reversed-phase column eluted with acetonitrile-water solution. The ultraviolet-visible absorbance of the column effluent was monitored in 200-350 nm range of a photodiode-array detector or at lambda max 289.6 nm for ceftiofur, lambda max 265.8 nm for desfuroylceftiofur and lambda max 271.4 nm for dimer of desfuroylceftiofur. Recoveries of ceftiofur from bovine milk spiked with 1 and 10 micrograms/ml were 95.9 and 97.0% with coefficients of variation of 3.69 and 2.51%, respectively. Recovery of ceftiofur from bovine serum spiked with 10 micrograms/ml was 90.4% with a coefficient of variation of 5.29%. A correlation coefficient of 0.9992 occurred with ceftiofur in aqueous solutions (n = 5, in duplicates). The limit of detection was estimated to be approximately 50 ppb (ng/ml). Additionally, this paper documents the presence of a ceftiofur metabolite in bovine serum under in vitro and in vivo conditions. The metabolite was identified as desfuroylceftiofur together with its dimer 3,3'-desfuroylceftiofur disulfide by thermospray liquid chromatography-mass spectrometry.

Animals↗
PubMed1993

The influence of clinical history on visual search with single and multiple abnormalities.

RATIONALE AND OBJECTIVES: Facilitation of detection by clinical history generally has been found with a single abnormality per image but not with multiple abnormalities. Multiple abnormalities per image can occasion a "satisfaction-of-search" effect in which detection of one lesion is reduced in the presence of other distant lesions. Our experiment studied the combined effect of multiple abnormalities and clinical history on accuracy. METHODS: Detection of native lesions was measured 1) with histories suggestive of the native abnormality; 2) with these histories and added simulated pulmonary nodules; and 3) with the same added nodules and histories suggestive of metastatic disease. These conditions also were compared with those of a previous experiment that were similar but included no history. RESULTS: Detection was substantially improved for appropriately prompted abnormalities even in the presence of a pulmonary nodule. In fact, satisfaction of search was not found in the presence of an appropriate history. Detection of unprompted abnormalities was unchanged when prompts indicated other abnormalities actually present. Prompted abnormalities were detected earlier in search. CONCLUSIONS: History appears to direct perceptual resources to the prompted abnormalities, thereby alleviating satisfaction of search. The presence of nodules yielded a small but consistent reduction in total search time for searches involving false responses, suggesting that satisfaction of search may depend more on reduction in search time than had been indicated by previous research.

Diagnostic Errors↗
PubMed1993

Ibuprofen treatment of endotoxin-induced mastitis in cows.

Ibuprofen treatment was compared with saline solution treatment in an endotoxin-induced experimental model of bovine mastitis. Acute mastitis was induced in healthy lactating Holstein cows (n = 12) by intramammary inoculation of 1 mg of Escherichia coli 026:B6 lipopolysaccharide in a single quarter per cow. Cows were assigned at random to ibuprofen (25 mg/kg of body weight, IV, n = 6) or 0.9% sodium chloride solution control (1.25 ml/kg, IV, n = 6) treatment groups. Ibuprofen or saline solution was administered once, 2 hours after endotoxin administration. The clinical course of endotoxin-induced mastitis and hematologic, clinical biochemical, and plasma mineral changes were monitored and compared between ibuprofen-treated and control cows. Clinical monitoring and blood sample collection were performed at 0, 2, 4, 6, 8, 12, 24, 48, 96, and 192 hours after endotoxin challenge. Rectal temperature and heart and respiratory rates were significantly (P < or = 0.05) increased in saline treated cows, compared with cows treated with ibuprofen. Blood eosinophil count and serum phosphorus, sodium, and total carbon dioxide concentrations were significantly (P < or = 0.05) decreased in saline-treated cows, compared with cows treated with ibuprofen. Ibuprofen treatment did not significantly change ruminations per minute, electrical conductivity of milk, quarter size, or quarter inflammation. The remaining hematologic, serum biochemical, plasma mineral, and coagulation values also were not changed significantly in response to ibuprofen treatment. Untoward effects attributed to ibuprofen administration were not observed. These results indicate that ibuprofen may provide empiric relief of clinical signs of coliform-induced mastitis.

Analysis of Variance↗
PubMed1993

Pharmacokinetics of ibuprofen in lactating dairy cows.

The pharmacokinetics of ibuprofen were studied in 6 adult lactating dairy cows after a single IV or oral administration of ibuprofen (25 mg/kg of body weight). Ibuprofen concentrations in milk and serum were analyzed by use of high-performance liquid chromatography. The lower limit of detection of the ibuprofen assay was 50 ng/ml. Serum ibuprofen concentration-time curves after IV administration best fit an open two-compartment model. Harmonic mean volume of distribution at steady state was 0.14 (range, 0.12 to 0.17) L/kg, elimination half-life was 1.55 (range, 1.33 to 1.73) hours, and total clearance was 86.2 (range, 68.8 to 106.2) ml/kg/h. Harmonic mean oral bioavailability was 99% (range, 79 to 112). Adverse effects were not observed in cows given ibuprofen.

Administration, Oral↗
PubMed1993

Pharmacokinetics of ibuprofen in lactating dairy goats.

Pharmacokinetic variables of ibuprofen were studied in 6 adult lactating dairy goats after single administration of the drug (14 and 25 mg/kg of body weight, IV, and 50 and 100 mg/kg, PO). Each of the goats was given all doses, with a minimum of 1 week between doses. Ibuprofen concentration in serum was analyzed by use of high-performance liquid chromatography. The lower limit of detection for the ibuprofen assay was 50 ng/ml. Ibuprofen pharmacokinetic variables after IV administration best fit an open two-compartment model. Geometric mean (range) volume of distribution at steady state was 0.16 (0.11 to 0.19) and 0.17 (0.15 to 0.19) L/kg, and terminal half-life was 1.08 (0.79 to 1.70) and 1.27 (1.03 to 1.88) hours, for ibuprofen dosages of 14 and 25 mg/kg, respectively. After 50 and 100 mg/kg administered orally, bioavailability was 90.8 and 106%, respectively. Area under the curve increased linearly with dose administered. Adverse effects were not observed in goats given ibuprofen.

Administration, Oral↗
PubMed1992

Mycoplasma mycoides subspecies mycoides as the cause of a subauricular abscess and mastitis in a goat.

A 6-year-old female goat was admitted with right-sided subauricular swelling and facial nerve paralysis. Mastitis developed subsequently. The subauricular swelling localized to a mass and was excised. Mycoplasma mycoides subsp mycoides was cultured from samples obtained from the mass and mammary gland. After clinical improvement, the goat was discharged to the owner with instructions to isolate the goat and to submit milk samples from the rest of the herd for microbial culturing. Mycoplasma spp can spread to other tissues from an initial site of infection. In goats with clinical signs similar to those of the goat of this report, samples should be obtained for microbial culture on Mycoplasma medium. Goats infected with Mycoplasma spp should be isolated or culled because of the risk of transmission to uninfected animals.

Abscess↗
PubMed1992

High-performance liquid chromatographic analysis of amphotericin B in plasma, blood, urine and tissues for pharmacokinetic and tissue distribution studies.

A sensitive and reproducible high-performance liquid chromatographic method was developed to assay ampherotericin B in plasma, blood, urine and various tissue samples. Amphotericin B was isolated from each sample matrix by solid-phase extraction (Bond-Elut). The eluate from Bond-Elut containing amphotericin B was injected onto a reversed-phase C18 column (Waters, mu Bondpak, 10 microns, 300 mm x 3.9 mm I.D.) with a mobile phase of 45% acetonitrile in 2.5 mM Na2EDTA at 1 ml/min. Detection of amphotericin B was by ultraviolet absorption at 382 nm. Blood and tissues were homogenized and extracted with methanol prior to Bond-Elut extraction. The extraction efficiencies of amphotericin B from plasma, blood and tissues were approximately 90, 70 and 75%, respectively. The sensitivity of the assay was less than or equal to 5 ng/ml for plasma, less than or equal to 25 ng/ml for blood, 2.5 ng/ml for urine and 50 ng/g for tissues. The linearity of the assay method was up to 2.5 micrograms/ml for plasma, 5 micrograms/ml for blood, 500 ng/ml for urine and 500 micrograms/g for tissues. The assay was reproducible with an intra-day coefficient of variation (C.V., n = 3) of less than 5% in general for plasma, blood and tissues. The inter-day C.V. of the assay was less than 5% for plasma (n = 5), less than 10% for blood (n = 4) and less than 5% for tissues (n = 3). The overall variability in the urine assay was generally less than 10%. This method has demonstrated significant improvement in the sensitivity and reproducibility in assaying amphotericin B in plasma and especially in blood, urine and tissues. We have employed this assay to compare the pharmacokinetic and tissue distribution profiles of amphotericin B in rats and dogs following administration of Fungizone and ABCD (amphotericin B-cholesteryl sulfate colloidal dispersion), a lipid-based dosage form. In addition, the assay method for plasma and urine samples can also be applied to pharmacokinetics studies of amphotericin B in man.

Amphotericin B↗
PubMed1992

Polymorphonuclear neutrophil leukocyte function in clinical bovine patients and in cows with or without Staphylococcus aureus mastitis.

A fluorochrome microassay was used to investigate peripheral blood polymorphonuclear leukocyte (PMNL) function in cattle. Glass-adherent PMNL were reacted with Staphylococcus aureus preincubated in 20% bovine serum for 30, 60 and 90 min. Coverslips were stained with acridine orange (AO) followed by crystal violet to quench extracellular bacterial fluorescence. PMNL function was evaluated by counting the number of dead (stained red with AO) and live (stained green with AO) S. aureus contained within 100 PMNL. A phagocytic index was calculated as the average number of bacteria contained within PMNL. The percentage killing of S. aureus was calculated from the average proportion of S. aureus within PMNL that were dead. Six clinically normal Holstein calves, 3-4 months of age, were sampled on 6 consecutive days. PMNL phagocytosis and killing did not vary significantly (p greater than 0.05) among repeated samplings per calf. PMNL function increased with increasing time of incubation of PMNL with S. aureus. Means (+/- SD) for percentage killing were 46.7 +/- 13.1, 57.4 +/- 11.6, and 62.1 +/- 9.8% for 30, 60 and 90 min of reaction, respectively. Means (+/- SD) for the phagocytic index were 2.9 +/- 0.8, 3.6 +/- 1.0, and 4.2 +/- 1.1 bacteria/PMNL for 30, 60 and 90 min of reaction, respectively. PMNL function was determined in 30 normal cattle of various breeds, age and sex, and these values were pooled to provide normal values for PMNL function. When values for bovine clinical patients (n = 25) with various diagnoses were compared with normal values (defined by the mean +/- 2SD for the 30 normal cattle) for PMNL function, only one patient was observed to exhibit PMNL hypofunction. A cow with disseminated intravascular coagulation in association with peracute coliform mastitis exhibited decreased PMNL killing capacity. Abnormal PMNL function was uncommon in the hospital population studied. Peripheral blood PMNL function was evaluated in lactating Holstein cows with (n = 15) or without (n = 15) chronic subclinical S. aureus mastitis. There was no significant (p greater than 0.05) difference in PMNL function among these cows.

Acridine Orange↗
PubMed1991

The influence of anti-inflammatory therapy on bacterial clearance following intramammary Escherichia coli challenge in goats.

Coliform mastitis in dairy cattle frequently results in systemic disease with occasional deaths in association with endotoxic shock. Systemic anti-inflammatory therapy has been used to alter the course of endotoxic shock in severe cases. Use of anti-inflammatory therapy has been questioned on the basis that such treatment may compromise immune function and decrease clearance of bacteria from infected mammary glands. The purpose of this investigation was to determine whether anti-inflammatory therapy influenced bacterial clearance following intramammary challenge of lactating goats with Escherichia coli. Standardized quantities of a pathogenic coliform culture were infused through the teat canal into one half of the mammary gland in 18 goat does. The does were then randomly assigned to receive one of three intravenous treatments: saline (controls), one dose of steroid (dexamethasone), or two doses of a non-steroidal anti-inflammatory agent (flunixin meglumine). The clinical signs, milk production, complete blood counts, serum clinical chemistry values, milk bacterial cultures and milk somatic cell concentrations were monitored sequentially. Goats treated with anti-inflammatory agents exhibited some improvement in clinical response to challenge with E. coli (e.g. rectal temperature, degree of appetite suppression) as compared to saline controls. There were no significant differences between treatments in the degree of inflammation present in the mammary glands or supramammary lymph nodes examined at necropsy. The most important finding was that anti-inflammatory therapy did not adversely influence the clearance of E. coli from challenged glands.

Animals↗
PubMed1991

Influence of age on neutrophil function in foals.

Functional activities (phagocytosis and killing) of neutrophil leucocytes (NL) and immunoglobulin G concentrations were evaluated in six healthy foals from birth to 6 months of age. Peripheral blood NL were reacted with Streptococcus equisimilis in 20 per cent pooled equine serum for 30, 60 and 90 mins and functional activities of NL were determined using a fluorochrome microassay. Values for foal NL function were compared with those of healthy adult horses (n = 28). Foal neutrophil function was influenced by age. Killing capacity of NL decreased, whereas phagocytic capacity increased, until 113 days of age, after which a reversal in trends became apparent. Immunoglobulin G concentrations changed significantly over time and were lowest at 29 to 56 days of age. All foal values for NL function fell within the range of normal values established for healthy adult horses.

Aging↗
PubMed1991

Conjugal transfer of a shuttle vector from the human colonic anaerobe Bacteroides uniformis to the ruminal anaerobe Prevotella (Bacteroides) ruminicola B(1)4.

Prevotella ruminicola (formerly Bacteroides ruminicola) is an anaerobic, gram-negative, polysaccharide-degrading bacterium which is found in the rumina of cattle. Since P. ruminicola is thought to make an important contribution to digestion of plant material in rumina, the ability to alter this strain genetically might help improve the efficiency of rumen fermentation. However, previously there has been no way to introduce foreign DNA into P. ruminicola strains. In this study we transferred a shuttle vector, pRDB5, from the colonic species Bacteroides uniformis to P. ruminicola B(1)4. The transfer frequency was 10(-6) to 10(-7) per recipient. pRDB5 contains sequences from pBR328, a cryptic colonic Bacteroides plasmid pB8-51, and a colonic Bacteroides tetracycline resistance (Tcr) gene. pRDB5 was mobilized out of B. uniformis by a self-transmissible Bacteroides chromosomal element designated Tcr Emr 12256. pRDB5 replicated in Escherichia coli as well as in Bacteroides spp. and was also mobilized from E. coli to B. uniformis by using IncP plasmid R751. However, direct transfer from E. coli to P. ruminicola B(1)4 was not detected. Thus, to introduce cloned DNA into P. ruminicola B(1)4, it was necessary first to mobilize the plasmid from E. coli to B. uniformis and then to mobilize the plasmid from B. uniformis to P. ruminicola B(1)4.

Animals↗
PubMed1991

Molecular analysis of major histocompatibility complex alleles associated with the lupus anticoagulant.

Autoantibodies to phospholipids (APA) occur frequently in systemic lupus erythematosus (SLE) and other autoimmune disorders and predispose to intravascular thromboses. Major histocompatibility complex (MHC) class II alleles (HLA-DR and DQ) were determined by restriction fragment length polymorphisms (RFLP) in 20 patients with APA (lupus anticoagulant). HLA-DQw7 (DQB1*0301), linked to HLA-DR5 and -DR4 haplotypes, occurred in 70% and was significantly increased compared to 139 race-matched normal controls (P = 0.002, P corrected [pc] = 0.05, odds ratio [OR] = 5.1). Moreover, the frequency of HLA-DQw7 was significantly higher in SLE patients with APA as compared with patients without APA but with other autoantibodies, including anti-Ro and La (P = 0.0001, pc = 0.002, OR = 10.7), anti-Ro alone (P = 0.001, pc = 0.02, OR = 11.2), anti-dsDNA (P = 0.001, pc = 0.02, OR = 7.1), and possibly anti-Sm (P = 0.04, pc = NS, OR = 6.8) and anti-nRNP (U1-RNP) (P = 0.01, pc = NS, OR = 7.8). The DQB1*0301 allele of DQw7 showed the strongest association, while the frequencies of the DQA1*0301 (45%) and DQA1*0501 (50%) alleles did not differ from the controls. Among the HLA-DQB1*0301 (DQw7) negative patients, all possessed HLA-DQw8 (DQB1*0302) and/or HLA-DQw6 (DQB1*0602 or DQB1*0603) alleles. The HLA-DQB1*0301 chain shares an identical seven amino acid sequence with DQB1*0302, *0602, and *0603 chains in the third hypervariable region of the HLA-DQ molecule. This candidate "epitope" may play a role in mediating an autoimmune response to APA.

Alleles↗
PubMed1991

Restriction fragment length polymorphism analysis of HLA-DR, DQ, DP and C4 alleles in Caucasians with systemic lupus erythematosus.

HLA-DR, DQ, DP and C4 null alleles were determined by restriction fragment length polymorphism (RFLP) analysis in 60 Caucasian patients with systemic lupus erythematosus (SLE) and 66 controls. DR3 (DRw17) and DQw2.1 were increased in frequency in the patients with SLE associated with the presence of C4A null genes. HLA-DP alleles determined by RFLP analysis of genomic DNA as well as of PCR amplified DNA were not associated with SLE or any clinical or autoantibody subset thereof. No DR, DQ, or C4 null gene association was found with renal or neuropsychiatric involvement or nDNA antibodies (or levels thereof). These data suggest that the primary predisposition to SLE lies with HLA-DR or C4 null alleles, and not with HLA-DP.

Alleles↗
PubMed1991

Renal clearance and fractional excretion of electrolytes over four 6-hour periods in cattle.

Four consecutive 6-hour urine sample collections were performed on 7 healthy adult Holstein cows fed a diet of coastal Bermuda hay with ad libitum water consumption. Urine (via indwelling urinary catheter) and venous blood samples were collected at 6, 12, 18, and 24 hours. Total 24-hour urine production for the 7 cows ranged from 4,515 to 7,130 ml/d (mean +/- SD, 5,633 +/- 946 ml/d) or 0.02 to 0.04 ml/kg of body weight/d (mean +/- SD, 0.03 +/- 0.007 ml/kg/d). Renal clearance (C) of creatinine (Cr), sodium (Na), calcium (Ca), and magnesium (Mg) varied significantly (P less than 0.05) among individuals, but did not vary significantly among the four 6-hour collection periods. Clearance of chloride (Cl) and phosphorous (P) did not vary significantly either among individuals or among the four 6-hour periods. Clearance of potassium (K) varied significantly (P less than 0.05) among individuals and among the four-6-hour periods. Creatinine clearance was significantly (P less than 0.01) correlated with C(Cl), C(Ca), C(P), and C(Mg) when all data were considered. Significant (P less than 0.05) correlations were also found between C(Cl) and C(K), C(Ca), C(P), and C(Mg); between C(Ca) and C(P) and C(Mg); and between C(P) and C(Mg). Fractional excretion (FE) of Na, K, Cl, Ca, P, and Mg did not vary significantly among the four 6-hour periods. Fractional excretion of Na, Ca, and Mg (P less than 0.01) and K and P (P less than 0.05) varied significantly within individuals among the 6-hour periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Bovine viral diarrhea virus-induced cerebellar disease in a calf.

Bovine viral diarrhea virus (BVDV) was isolated from buffy coat cells of a 10-day-old calf with signs of cerebellar disease--ataxia, hypermetria, and intention head tremor. The tentative diagnosis was BVDV-induced cerebellar hypoplasia. At necropsy, gross lesions were not identified. Histologic findings suggested BVDV-induced diffuse hypomyelination throughout the CNS, as reported in the United Kingdom and The Netherlands.

Animals↗
PubMed1990

Suspected actinobacillosis manifested by facial enlargement in a heifer.

Actinobacillosis was the suspected cause of severe, bilateral facial enlargement of 8 months' duration in a 2.5-year-old Holstein heifer. Serum protein electrophoresis revealed a polyclonal gammopathy. Necropsy findings indicated that facial swelling was caused by fibrosis between the skin and underlying bone. Lesions were characterized microscopically by scattered pyogranulomas containing eosinophilic, club-like colonies surrounding gram-negative bacterial rods. The lesion was compatible with diagnosis of actinobacillosis. It is unusual for severe bilateral facial enlargement to be associated with actinobacillosis.

Actinobacillosis↗