On the mode of action of the organophosphorus fungicide Hinosan

Samenvatting In onderzoek naar werkingsmechanismen van fungicide organische fosforverbindingen werd aangetoond dat Hinosan bijPiricularia oryzae tussenprodukten van de chitinesynthese kan doen ophopen. Dit duidt op een beïnvloeding van de chitinesynthese. De verbinding heeft ook een effect op de permeabiliteit van de celwandmembraan. Waarschijnlijk is dit effect primair verantwoordelijk voor de fungitoxiciteit van Hinosan en moet de remming van de chitinesynthese als een indirect effect worden beschouwd.     

Analysis of Mammalian Masticatory Mechanisms: Progress and Problems

Direct measurement of bone movements and muscle activation in mammalian mastication is now possible. Early results indicate that the patterns are quite variable and depart from the stereotyped versions sometimes reported. Most mammals masticate unilaterally; only a few chew simultaneously on both sides. Orbital movements are complex and three-dimensional. While most muscles are active during the reduction phase, it is difficult to define phases by sharp transitions of activity. The fascicles of pinnate muscles differ in fiber architecture and physiology; they tend to function at different times and with distinct mechanical advantages. Interspecific diversity and marked responses to food consistency and size, still preclude generalizations. Improved methods for comparisons among orbits, for correlation of forces and excursions, and automated correlations of movements, forces and electromyograms are beginning to be available and need to be more generallv applied to analysis.     

Breakdown of pisatin by some fungi pathogenic to Pisum sativum

Samenvatting Aan een voedingsmedium, geïnoculeerd met elk der schimmelsFusarium oxysporum f. sp.pisi ras 1,Mycosphaerella pinodes (pathogenen van de erwt),Cladosporium cucumerinum, Colletotrichum lindemuthianum enMonilinia fructigena (niet-pathogenen van de erwt) werd pisatine toegevoegd. Na incubatie gedurende een week werd het medium gecentrifugeerd. Zowel de bovenstaande vloeistof als het mycelium werd onderzocht op de aanwezigheid van pisatine. Uit de U.V.-absorptiespectra van de vloeistof en alcoholextracten van het mycelium blijkt, dat beide pathogenen het pisatine kunnen afbreken, maar de drie niet-pathogenen niet.     

Plasma pro-opiomelanocortin, pro-adrenocorticotropin hormone, and pituitary adenoma size in dogs with Cushing's disease

It is difficult to predict the size of pituitary corticotroph tumors in dogs with Cushing's disease (pituitary-dependent hyperadrenocorticism [PDH]) without pituitary imaging techniques. The purpose of this study was to examine the relationship between plasma adrenocorticotropin hormone (ACTH) precursor concentration and pituitary size in dogs with Cushing's disease. Plasma concentrations of ACTH precursors (pro-opiomelanocortin [POMC]/pro-ACTH) and pituitary tumor height/brain area were measured in 36 dogs with pituitary corticotroph adenomas of various sizes. There was a correlation between tumor size (measured as the pituitary tumor height/brain area ratio [P/B]) and POMC/pro-ACTH concentration (r = .70; P < .0001). Dogs with P/B > or = 0.40 x 10(-2) mm(-1) had higher concentrations of ACTH precursors than dogs with P/B < 0.40 x 10(-2) mm(-1) (median concentration 85 pmol/L, range 15-1,350 pmol/L, n = 14 versus 15 pmol/L, range 15-108 pmol/L, n = 22; P < .0001). With a threshold of 35 pmol/L of POMC/pro-ACTH concentration, the estimated sensitivity and specificity of the kit were 93% (95% confidence interval [CI], 79-100%) and 86% (95% CI, 73-100%), respectively. We interpret these data as indicating that measurement of POMC and pro-ACTH might be of value in the characterization of tumor size in dogs with Cushing's disease. Low POMC/pro-ACTH concentrations make it unlikely that a large pituitary tumor exists in dogs with PDH.     

Evaluation of intravenous pamidronate administration in 33 cancer-bearing dogs with primary or secondary bone involvement

The purpose of this study was to evaluate the clinical safety of pamidronate when administered at a mean dosage of 1.0 mg/kg IV q28d in 33 tumor-bearing dogs. Biochemical tests of renal function were evaluated before each successive pamidronate treatment. Of 33 dogs treated with pamidronate, 1 dog had clinically relevant increases in serum creatinine and blood urea nitrogen concentrations. The biologic activity of IV pamidronate was assessed prospectively in 10 dogs with appendicular osteosarcoma and was assessed on reductions in urine N-telopeptide excretion (P = .042) and enhanced bone mineral density of the primary tumor measured with dual-energy x-ray absorptiometry (P = .024). Additionally, in these 10 dogs, pamidronate's therapeutic activity was supported by subjective improvement in pain control in 4 of the 10 dogs treated. IV pamidronate appears clinically safe in tumor-bearing dogs and may possess modest biologic activity for managing neoplastic complications associated with pathologic bone resorption.