Selective venting of cigarette smoke in dichotomous ducts and preserved human bronchi

Mechanically generated cigarette smoke and ambient air were injected into dichotomous ducts and geometrically preserved human bronchi in a fashion simulating typical smoking technique. When the air passages were at ambient temperature, the smoke settled into the lower branches. Smoke which was injected into passages warmed to body temperature rose to the upper branches. The latter selective distribution of the smoke resembled the distribution of centrilobular emphysema in the lungs.     

Borreliosis in dogs from southern Connecticut

Blood samples were obtained from dogs in tick-infested regions of southern Connecticut to assess canine exposure to Borrelia burgdorferi, the etiologic agent of Lyme disease in human beings. An indirect fluorescent antibody test detected immunoglobulin (Ig)M antibodies at titers of 1:64 to 1:512 in 22 of 84 serum samples previously shown to be positive with a polyvalent rabbit anti-dog total Ig conjugate. Analyses of paired serum samples from 20 seropositive dogs revealed temporal differences in titers; changes occurred during brief (1 month) or extended (greater than 4 years) sampling periods. Clinical records for 52 seropositive dogs indicated a history of intermittent lameness in 19 of these. Limb/joint disorders typically developed in dogs without IgM antibodies, suggesting manifestation during later phases of illness. A microscopic-agglutination test was used to assess cross reactivity between B burgdorferi and 20 serovars of Leptospira interrogans and biflexa. Analyses of 63 dog serum specimens with antibodies to B burgdorferi and a series of reference rabbit sera revealed minor antigenic relatedness. There was geographic clustering of dogs with antibodies to B burgdorferi in areas of south-central and southeastern Connecticut, where human Lyme disease also occurs.     

Discospondylitis and orchitis associated with high Brucella titre in a dog

A case of discospondylitis and orchitis associated with high Brucella titre in a dog is presented. Clinical signs included intermittent pain, poor appetite and a decreased level of physical activity. Radiographic evidence of discospondylitis was found. Histopathological findings on the testes are included. Treatment regime and clinical progress are given. Diagnosis and treatment of B. canis are described and a brief review of the treatment of discospondylitis is presented.     

Production of a Mating Inhibitor by Ustilago hordei

ABSTRACT Ustilago hordei, the cause of barley covered smut, was found to produce a factor that inhibited its own mating. The mating inhibition factor (MIF) specifically inhibited mating of U. hordei and other Ustilago spp., but not teliospore germination or sporidial growth. MIF did prevent teliospore germination of Tilletia caries and T. contraversa. MIF was found at low levels in culture supernatants of either mating type of U. hordei grown separately, but at higher levels when both mating types were grown together, in the supernatants of MAT-1 mating type cells transformed with the MAT-1 pheromone gene mfa1 and of MAT-2 cells transformed with either mfa1 or the MAT-1 pheromone receptor gene pra1. Diploid cells produced no detectable inhibitor, nor did MAT-1 cells with a disrupted mating type locus that deleted both mfa1 and pra1. MIF production was restored when mfa1, but not pra1, was added back to the MAT-1Delta cells. MIF activity was altered by protease treatment. Highly purified MIF from MAT-1 cells contained cysteine methyl ester, farnesyl cysteine, farnesyl cysteine methyl ester, and a dodecapeptide with a mass consistent with that of MAT-1 pheromone lacking the terminal cysteine. Since smut fungi must first mate to become pathogenic, mating inhibition has the potential to be an effective method of disease control for these pathogens.