IMAGING OF PHEOCHROMOCYTOMA IN 2 DOGS USING p-[18F] FLUOROBENZYLGUANIDINE

p-[18F]Fluorobenzylguanidine ([18F]PFBG) is a norepinephrine analog that has been developed as a positron emission tomography (PET) imaging radiopharmaceutical. Myocardial sympathetic innervation, neuroendocrine structures, and tumors can be noninvasively imaged with [18F]PFBG. In this study, the uptake characteristics of [18F]PFBG were investigated in 2 dogs with a spontaneous pheochromocytoma. The extent of the pheochromocytoma was well documented in both dogs on the PET study. The standardized uptake values within the pheochromocytomas were greater than 25 by 10 min, and were 37 and 50 by 45 min in each dog. A third dog that was suspected to have an adrenal mass was also studied. In this dog, the [18F]PFBG study was normal. Surgical exploration and adrenal biopsy confirmed the [15F]PFBG imaging findings in both dogs. In each dog, there was rapid blood-pool clearance (within 10 min after intravenous administration of the [18F]PFBG), with high uptake specific within the myocardium and adrenal medulla. The results indicate that [18F]PFBG may be useful for imaging canine pheochromocytomas and aid in differentiating adrenal masses.     

Molecular Variability among Strains of Pasteurella multocida Isolated from an Outbreak of Haemorrhagic Septicaemia in India

The applicability of conventional and molecular methods for rapid detection and differentiation of Pasteurella multocida serogroup B isolates involved in an outbreak of haemorrhagic septicaemia affecting Indian buffaloes, was studied. Five isolates were obtained and were subjected to phenotypic and genotypic characterization. None of the five isolates could be differentiated on the basis of cultural, biochemical, pathogenicity and antimicrobial sensitivity patterns. Polymerase chain reaction (PCR)-based techniques were found to be specific and sensitive for rapid detection and differentiation of isolates. Repetitive extragenic palindromic (REP-) PCR, enterobacterial repetitive intergenic consensus (ERIC-) PCR and single-primer PCR differentiated all the five isolates into different profiles. All the isolates involved in the outbreak were found to have a genetic profile different from standard P. multocida strain (P52). However, three isolates had similar profiles, whereas each of the remaining two had a different profile. The study indicates the involvement of multiple strains of P. multocida in a single outbreak of haemorrhagic septicaemia in buffaloes. The results also indicate that molecular methods of detection and typing are superior to conventional methods for rapid epidemiological investigations of haemorrhagic septicaemia.     

Plant regeneration of an endangered medicinal plant Hydrastis canadensis L.

Goldenseal (Hydrastis canadensis L.) is an endangered medicinal plant used to treat sore eyes and mouths, cold and flu and also as a dye. The objective of this study was to develop an efficient in vitro propagation protocol for goldenseal. Significantly more shoots (26 shoots per leaf explants) were induced on a medium containing 2.5 μM thidiazuron (TDZ) and 5.0 μM 1-naphthaleneacetic acid (NAA) than any other treatment. Sub-culturing regenerated shoots on a medium with 5.0 μM 6-benzylaminopurine (BA) induced the maximum rate of shoot multiplication. Growth of the regenerated shoots in a temporary immersion bioreactor resulted in significant increases in biomass, shoot height and shoot multiplication. The regenerated shoots from the temporary immersion bioreactor formed roots when transferred onto a medium with 1.0–2.0 μM indole-3-butyric acid (IBA). Regenerated whole plantlets were acclimatized and maintained in standard greenhouse conditions for further growth. The regeneration protocol developed in this study provides a basis for germplasm conservation and for further investigation of this rare, medicinally important species.     

Serological Identification of Escherichia coli Isolated From Cats and Dogs

In a group of 112 cats, examined during an outbreak of diarrhea, 104 (92.8%) yielded Escherichia coli with identifiable O groups as compared to 12 (21.8%) of 55 control cats apparently free of intestinal ailments. E. coli group O6 occurred in 49.1% of the cats with diarrhea, and persisted in this group of cats at about the same rate when examined for a period of ten months. E. coli group O6 was not isolated from the control group.

Specimens were also collected from dogs with various clinical signs. E. coli O4 and O6 strains appear to be important potential pathogens for canine species and were found to spread from one dog to another when in close contact. E. coli group O4 was identified in ten and O6 in three of 14 dogs examined. All isolates in which the O group could be identified were hemolytic.

     

Strain differentiation of Indian isolates of Salmonella by ERIC-PCR

Enterobacterial repetitive intergenic consensus (ERIC) sequences are the repetitive elements present in the family enterobacteriacae. In the present study, ERIC-PCR (target ERIC sequence) was used for the molecular typing of 24 isolates of Salmonella serovars, namely abortusequi, choleraesuis, bareilly and dublin. In ERIC-PCR, seven molecular types were observed with ERIC-Cl primer, and nine molecular types with ERIC-C2 primer. When the results of both the ERIC-PCR were combined for molecular typing, 21 molecular types were observed, which indicated a high degree of discrimination. Both the ERIC primers are designed from the ERIC consensus sequence, yet they gave different profiles, indicating that they supplement each other. ERIC sequences were found to be useful targets for molecular typing. The different profiles observed appear to be due to differences in ERIC sequences and differences in inter-ERIC distance. The study indicates that ERIC-PCR is a very efficient tool for molecular typing of Salmonella species.     

Immune responses induced by DNA vaccines encoding Newcastle virus haemagglutinin and/or fusion proteins in maternal antibody-positive commercial broiler chicken

1. The immune responses induced by recombinant plasmids containing Newcastle disease virus (NDV) F (pVAX.nd.f) or HN (pcDNA.nd.hn) genes separately or in combination in bi-cistronic (pIRES.nd.hn.f) constructs were evaluated in maternal antibody-positive commercial chicks. 2. Immunofluorescence and immunoperoxidase tests demonstrated the expression of both F and HN proteins in Vero cells. Real-time PCR analysis revealed the expression of HN and/or F genes in muscle, peripheral blood mononuclear cells (PBMC), spleen and liver after immunisation. 3. Chicks inoculated intramuscularly thrice (two booster doses) with pVAX.nd.f and pcDNA.nd.hn did not develop detectable haemagglutination inhibiting (HI) antibodies. In contrast, an increase in a NDV-specific cell-mediated immune response was demonstrated. 4. After challenge with virulent NDV, chicks immunised with the recombinant plasmids as well as those in control groups succumbed to Newcastle disease. 5. Based on these results, it is concluded that DNA vaccines containing HN and/or F genes fail to protect commercial chicks, possibly due to interference from maternal antibodies.     

Structural and functional changes in mouse fibroblast cells treated with 2,3-dichloro-1,4-naphthoquinone (dichlone)

When strain L mouse fibroblasts were treated with the substituted quinone pesticide dichlone (2,3-dichloro-1,4-naphthoquinone), a rapid loss of intracellular potassium, ATP, and protein with a concomitant increase in intracellular water and volume occurred. Electron microscopic examination showed a nonreversible swelling of the cells associated with the formation of large protruding blebs. The findings indicate that dichlone can alter the permeability of the cell membrane which may be one of the sites of action of the pesticide in the fibroblast cells. Menadione (2-methyl-1,4-naphthoquinone), a synthetic vitamin K, also a substituted quinone, was found to be less effective in short-term incubation at corresponding concentrations, althought it did produce loss of K⁺ ions and protein from the cell.The action of dichlone was compared with that of model compounds which are known to act on plasma membranes (p-chloromercuribenzene sulfonate—PCMBS) and those which interfere with intracellular energy metabolism (combination of antimycin A plus iodoacetate). From the results reported in this paper it appears that dichlone acts in most respects, like PCMBS, by a direct interaction with membrane components, but unlike PCMBS, dichlone enters the cell rapidly and stimulates oxygen uptake probably by constituting a bypass of electron transfer.     

Uptake,metabolism and effects of DDT,fenitrothion and chlorpyrifos on Tetrahymena pyriformis

The uptake and metabolism of DDT, fenitrothion and chlorpyrifos were studied in cultures of the ciliate protozoan Tetrahymena pyriformis. When cultures were treated with DDT in concentrations varying from 0.01 to 0.5 μg ml⁻¹, concentrations found in T. pyriformis were 3.8 to 335 μg g⁻¹ dry weight. The accumulation of fenitrothion ranged from 28.7 μg g⁻¹ in cultures treated with 1 μg ml⁻¹ to 2260 μg g⁻¹ in cultures treated with 10 μg ml⁻¹. Under similar experimental conditions chlorpyrifos was accumulated from 24.7 to 15400 μg g⁻¹. The patterns of uptake were dependent on the growth cycle, the ability of the organism to metabolise insecticide and the type of the insecticide used. Maximum accumulation of DDT, fenitrothion and chlorpyrifos occurred in 2, 4 and 6 h respectively. Tetrahymena metabolised DDT to DDD and DDE but failed to metabolise fenitrothion and chlorpyrifos. The effects on growth and morphology of T. pyriformis were studied over a period of 5 days. Higher concentrations (10, 50 and 100 μg ml⁻¹) of DDT inhibited only the growth of the organisms and did not change cell morphology. Fenitrothion was extremely toxic to the organisms and at 5 and 10 μg ml⁻¹ cells became more or less spherical and died after 48 h. However, concentrations of 0.5, 1 and 2.5 μg ml⁻¹ fenitrothion caused growth inhibition, but only at 2.5 μg ml⁻¹ was this permanent. Chlorpyrifos inhibited the growth of the organisms at 1, 5 and 10 μg ml⁻¹ but the morphology was affected only at 5 and 10 μg ml⁻¹.     

Chronic chlordane toxicity: Effect on blood biochemistry of Meriones hurrianae Jerdon,the Indian desert gerbil

Indian desert gerbils, administered with repeated doses of 2.5 mg/kg body weight chlordane to study the chronic toxic effects, show changes in serum proteins, blood glucose, alkaline and acid phosphatase activities. The effect of chlordane includes hyperproteinemia, hyperglycemia, enhanced serum alkaline and acid phosphatase activity. Possible reasons for changes are discussed.