Comparison of plasma pharmacokinetics and bioavailability of ceftiofur sodium and ceftiofur hydrochloride in pigs after a single intramuscular injection.

Ceftiofur sodium, a broad-spectrum cephalosporin, is active against gram-positive and gram-negative pathogens of veterinary importance. Two studies were designed to compare the intramuscular bioavailability of the current sodium salt and the new hydrochloride salt in pigs at doses of either 3 mg or 5 mg ceftiofur equivalents (CE)/kg body weight. Twenty-six healthy young pigs were selected for these two-period, two-treatment crossover studies, 12 for the 3 mg/kg study and 14 for the 5 mg/kg study. Each animal received one intramuscular (i.m.) injection of ceftiofur sodium and one i.m. injection of ceftiofur hydrochloride with a 14-day washout period between the two treatments. Blood samples were collected serially for up to 96 h postinjection. Plasma samples were then analysed using a validated assay that measures ceftiofur and all desfuroylceftiofur-related metabolites by high-performance liquid chromatography. In the 3 mg/kg dosage study, average maximum plasma concentration (C(max)) after administration of ceftiofur sodium was 15.8+/-3.40 microg/mL at 0.4-4 h after injection. After administration of ceftiofur hydrochloride, the C(max) was 11.8+/-1.67 microg/mL at 1-4 h after injection. Concentrations of ceftiofur and metabolites 72 h after the injection were 0.392+/-0.162 microg/mL for ceftiofur hydrochloride and 0.270+/-0.118 microg/mL for ceftiofur sodium. The mean area under the curve (AUC), from time 0 to the limit of quantitation (AUC(O-LOQ)) after ceftiofur hydrochloride administration, was 216+/-28.0 microg x h/mL, compared to 169+/-45.4 microg x h/mL after ceftiofur sodium administration. The calculated time during which plasma concentrations remained above 0.02 microg/mL (t(>0.2)) was 85.3+/-10.6 h for ceftiofur sodium and 77.2+/-10.7 h for ceftiofur hydrochloride. In the 5 mg/kg dosage study, C(max) after administration of ceftiofur sodium was 28.3+/-4.45 microg/mL at 0.33-2 h after injection. After administration of ceftiofur hydrochloride, the C(max) was 29.7+/-6.72 microg/mL at 0.66-2 h after injection. Concentrations of ceftiofur and metabolites 96 h after the injection were 0.274+/-0.0550 microg/mL for ceftiofur hydrochloride and 0.224+/-0.0350 microg/mL for ceftiofur sodium. The mean AUC(O-LOQ) after ceftiofur hydrochloride administration was 382+/-89.8 microg x h/mL compared to 302+/-54.4 microg x h/mL after ceftiofur sodium administration. The t(>0.2) was 78.9+/-9.65 h for ceftiofur sodium and 94.2+/-8.64 h for ceftiofur hydrochloride. Based on the similarity of the pharmacokinetic parameters of the sodium and hydrochloride formulations of ceftiofur, similar therapeutic efficacy can be inferred for the two products.

Determination of ceftiofur and its desfuroylceftiofur-related metabolites in swine tissues by high-performance liquid chromatography.

An HPLC method was developed and validated for the determination of ceftiofur-related metabolites that have the potential to be microbiologically active in swine muscle, kidney, liver and fat. Its performance was evaluated against incurred-residue swine tissues. This method is based on the cleavage of the disulfide and/or thioester bonds between the metabolites and their conjugate sulfur containing moiety using dithioerythritol to yield desfuroylceftiofur, and further stabilization to desfuroylceftiofur acetamide. The limit of quantitation was 0.1 micrograms ceftiofur equivalents/g tissue. The assay is specific for ceftiofur-related metabolites when evaluated against commercially available antibiotics for swine.

Karyotype findings and molecular analysis of the bcr gene rearrangement supplementing the histologic classification of chronic myeloproliferative disorders.

BACKGROUND: Histologic examination of bone marrow is important in establishing diagnoses among chronic myeloproliferative disorders (CMPD). Only a few studies, however, have compared cytogenetic or molecular genetic findings to histopathology in CMPD. Diverging results on the presence of the Ph1-translocation in patients with myelofibrosis have been reported. EXPERIMENTAL DESIGN: Cytogenetic studies and molecular analysis of the bcr gene were performed in bone marrow cells of patients with CMPD simultaneously with histopathologic examination of plastic-embedded bone marrow biopsies. RESULTS: The Ph1-chromosome was found in 120/128 (93%) cases with histopathologic diagnosis of chronic myeloid leukemia (CML), including a notable proportion of cases with an increase of megakaryocytes and/or myelofibrosis; the latter was associated with a significant increase of chromosome aberrations, in addition to Ph1. Among those additional changes in myelofibrosis of Ph1-positive CML were del (13q) and t(1;11) in one case each. A bcr gene rearrangement was detected in 92% (24/26) of the CML cases examined. All other groups of CMPD, comprising cases of myelofibrosis and unclassifiable cases, were Ph1-negative by both cytogenetics (n = 102) and molecular analysis (n = 18). Karyotype changes associated with myelofibrosis in various CMPD concerned mainly balanced translocations involving 1p36 and 11q11, deletions of 5q13-34, 3p, 11q23, 13(q12,q22), and 20q12 as well as gain of 1q and trisomy 3, 8, 19, or 21. In histologically unclassifiable CMPD, karyotyping provided additional information for the differential diagnosis. CONCLUSIONS: The correlation of cytogenetic findings and histopathologic features is helpful in confirming or supporting histopathologic diagnoses and in characterizing new marker chromosomes in CMPD.

[Cytogenetics and molecular studies confirm the histopathologic diagnosis of chronic myeloproliferative diseases]. / Zytogenetik und molekulare Untersuchungen sichern die histopathologischen Diagnosen von chronischen myeloproliferativen Erkrankungen ab.

The histopathological classification of chronic myeloproliferative disorders can be supported by applying cytogenetics and molecular genetics to the analysis of bone marrow or blood cells, as demonstrated in 253 cases evaluated. The Philadelphia translocation (9;22) is the most important genetic parameter, being specific for chronic myeloid leukemia. Conventional methods for the detection of the t(9;22) are karyotyping and Southern blot analysis of the bcr gene. The newly established technique of fluorescence in situ hybridization (FISH) allows visualization of bcr-abl fusion even in non dividing cells. Molecular cytogenetics for t(9;22) yield results that are rapid and reliable as well as easily quantifiable.

Evidence from molecular genetic and cytogenetic analyses that bone marrow histopathology is reliable in the diagnosis of chronic myeloproliferative disorders.

The reliability of histopathological diagnosis in bone marrow specimens from patients with chronic myeloproliferative disorders (CMPD) was evaluated by correlating the histological findings with molecular genetic and cytogenetic analyses of the Ph1-translocation. A rearrangement of m-bcr was detected only in patients (28/30) diagnosed histologically as chronic myeloid leukemia (CML). This finding was supported by the presence of a Ph1-chromosome in 24/26 patients with CML examined. All the patients with other types of CMPD, including polycythemia vera (PV), primary thrombocythemia (PTH) and chronic megakaryocytic-granulocytic myelosis (CMGM), as well as those with unclassifiable CMPD (CMPD.UC) were Ph1-negative (n = 38). The histopathological discrimination of CML from Ph1-negative varieties of CMPD was also reliable for patients with myelofibrosis complicating CML, CMGM and CMPD.UC. The results demonstrate that bone marrow histopathology allows a reliable diagnosis of CML. This is in contrast with hematological data such as high platelet counts which show considerable overlapping in the various forms of CMPD.

An experimental model for subclinical edema disease (Escherichia coli enterotoxemia) manifest as vascular necrosis in pigs.

An experimental model for subclinical edema disease was developed in weanling pigs. In multiple experiments, 3-week-old pigs were weaned, then inoculated intragastrically with 10(10) colony-forming units of an SLT-IIv-positive strain of Escherichia coli originally isolated from a pig with edema disease (principals). Control pigs were inoculated with a nonpathogenic E coli strain. Of 39 principals, 8 developed clinical edema disease within 14 days after inoculation. However, 20 of 21 principals that did not develop clinical signs of edema disease, but were submitted for necropsy examination at 14 days after inoculation, had characteristic vascular lesions of edema disease. Vascular lesions, found principally in ileum and brain, consisted of segmental necrosis of myocytes in the tunica media of small arteries and arterioles. None of the pigs inoculated with a nonpathogenic strain of E coli developed edema disease or vascular lesions. None of the principals necropsied at 2 days after inoculation had vascular lesions. Development of vascular lesions by 14 days after inoculation was used as the end point for detecting subclinical edema disease in the model.

Immunohistochemical and biochemical characterization of the mucin-type tumor associated antigen TAG-12 by monoclonal antibody 7A9.

The reactivity of monoclonal antibody 7A9 with normal and neoplastic human tissues and some biochemical characteristics of the antigen (TAG-12) bound by 7A9 were evaluated. Antibody 7A9 showed broad reactivity with various carcinomas in paraffin sections. High percentages of positive tumor cells, displaying membrane and cytoplasmic staining, were noticed in adenocarcinomas of the breast (83/85), serous cystadenocarcinomas of the ovary (15/16), and lung adenocarcinomas (14/16). TAG-12 antigen was also detectable in normal adult and fetal tissues, but the reactivity of 7A9 was mainly restricted to the luminal surface of epithelial cells. For biochemical analyses, TAG-12 antigen purified from T47-D breast carcinoma cells by lectin affinity chromatography was treated with different glycosidases and proteases and analyzed by immunoblotting with 7A9. The data indicate that the antigen recognized by 7A9 is a heavily sialated mucin-type glycoprotein with a molecular weight of more than 200 KD. Similar to all other antibodies against tumor associated antigens, monoclonal antibody 7A9 is not tumor-specific but displays tissue staining patterns with a high carcinoma-to-normal ratio. The strong reactivity with the majority of tumor cells in several carcinoma types suggests that 7A9 is useful for in vitro and in vivo targeting of those tumors.

[Cytogenetic examination of bone marrow cells in stem cell diseases of myelodysplastic syndromes]. / Zytogenetische Untersuchung von Knochenmarkszellen bei der Stammzellerkrankung des Myelodysplastischen Syndroms.

Cytogenetic examination of bone marrow cells was performed in 43 patients with myelodysplastic syndrome (MDS). MDS was diagnosed from bone marrow biopsies and smears according to the FAB classification. Of all 43 patients 24 (56%) had clonal karyotype changes including frequently monosomies of chromosomes #5 and #7 as well as interstitial deletions of the long arm of #5, 5 q-. Chromosome aberrations were observed in patients belonging to all FAB-subgroups, e.g. 11/15 patients with RA, 6/10 with RAEB, 5/9 with RAEB/T, and 1/9 with CMMoL. Complex chromosome aberrations involving more than 2 chromosomes occurred predominantly in patients with RAEB/T (4/9) but also in patients with RA (2/15) and RAEB (2/10), and correlated significantly (p less than 0.002) with a shorter survival. No correlation was found between chromosome aberrations and the development of ANLL in 9/43 patients (21%).