Effects of 1 alpha,25-dihydroxycholecalciferol on disuse osteoporosis in the dog: a histomorphometric study.

Disuse osteoporosis was produced in dogs by immobilization of the left rear limb in a plaster cast. The trabecular bone volume of the calcaneus was then determined following treatment with 1 alpha,25-dihydroxycholecalciferol for 4 weeks with oral dosages of 60 to 240 ng/kg of body weight. The trabecular bone volume percentage of the immobilized calcaneus was in direct relation to the dosage of 1 alpha,25-dihydroxycholecalciferol.     

Natural remission of nephrotic syndrome in a dog with immune-complex glomerular disease.

A nephrotic syndrome caused by immune-complex glomerular disease was diagnosed in a 4-year-old male Great Dane. The syndrome was characterized by proteinuria, hypoproteinemia, hypoalbuminemia, hypercholesterolemia, and subcutaneous edema. Renal biopsy revealed segmental membranous glomerular disease. The edema underwent complete remission 18 days after admission. Two months after admission, there was no clinical or laboratory evidence of glomerular disease. Periodic reevaluation of the dog during the next 2 years revealed recurrence of proteinuria, but no other clinical or laboratory abnormalities. Serial renal biopsies revealed persistence, but no appreciable increase, in the severity of the segmental membranous glomerular disease. The natural course of the nephrotic syndrome and immune-complex glomerular disease has been associated with unpredictable variability. It was concluded that the widespread use of corticosteroid or immunosuppressant therapy in dogs with immune complex glomerular disease should be withheld until the natural course of the disease has been evaluated in a significant number of patients and until the results of well-controlled clinical studies confirm or deny their therapeutic value.     

A comparison of polychromasia and reticulocyte counts in assessing erythrocytic regenerative response in the cat.

Three staining techniques were evaluated for use in assessing the erythrocytic regenerative responses in the cat. Using new methylene blue as a vital stain, the aggregate reticulocyte count closely corresponded to the reticulocyte count on air-dried smears stained with new methylene blue and to the polychromatophilic erythrocyte count on Wright's stained smears.     

Enhancement of fungicidal and insecticidal activity by reductive alkylation of chitosan

A series of N-alkyl chitosan (NAC) derivatives were synthesized using a reductive alkylation reaction to examine their fungicidal and insecticidal activity. The chemical structures were characterized by IR and (1)H NMR spectroscopy, and the degree of substitution (DS) ranged from 0.02 to 0.37. Their fungicidal activity was evaluated against the grey mould Botrytis cinerea Pers ex Fr (Leotiales: Sclerotiniaceae) and the rice leaf blast pathogen Pyricularia grisea Sacc [Teleomorph: Magnaporthe grisea (Hebert) Barr] by a radial growth bioassay. It was of interest that most of the NAC derivatives were more active against both fungi than chitosan itself. The most active derivative was N-(2,2-diphenylethyl)chitosan with EC50 values of 0.031 and 0.23 g L(-1) against B. cinerea and P. grisea respectively. In addition, some derivatives, at higher concentrations up to 1.0 g L(-1), inhibited the mycelial growth and spore formation of P. grisea. Bioassays against larvae of the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) with the NAC derivatives at a rate of 5.0 g kg(-1) in artificial diet demonstrated that N-(3-phenylbutyl)chitosan was the most active compound. In addition, N-propylchitosan, N-undecanylchitosan and N-(3-phenylpropyl)chitosan derivatives strongly inhibited larval weight gain in S. littoralis, with respective reductions of 76, 66 and 65% after 4 days of feeding on treated diet.