Morphologic observations on respiratory tracts of chickens after hatchery infectious bronchitis vaccination and formaldehyde fumigation

The histologic changes in the respiratory tracts of chickens were evaluated after hatchery fumigation with 40% formaldehyde vapors and vaccination against infectious bronchitis virus with live attenuated vaccine (Massachusetts serotype). One-day-old chickens were housed in four isolation units in controlled environmental conditions, fed and watered ad libitum, and separated into four groups: 1) fumigated and vaccinated birds (FV group); 2) nonfumigated and vaccinated birds (NFV group); 3) fumigated and nonvaccinated birds (FNV group); and 4) control group (C group). All birds were tested to be free from Mycoplasma gallisepticum and Mycoplasma synoviae. After necropsy on the first, eighth, and twenty-sixth days after birth, samples from tracheal upper portion and lungs were conventionally processed for light, scanning, and transmission electron microscopy. Tissue response was monitored by microscopic examination of trachea and lung. On the first day of observation, fumigated and vaccinated birds (FV group) showed extensively damaged tracheal epithelium with exfoliated areas and some active glands with electrodense granules, and in the lung, the primary bronchi epithelium had disorganized cilia and abundant lymphocytes, with emphysematous areas in tertiary bronchus. On day 8 after vaccination, cubical and cylindrical tracheal cell proliferation was observed, and on day 26, ciliated columnar epithelium was almost regenerated with heterophil corion infiltration, and hyaline cartilage nodules appeared in parabronchi. The nonfumigated and vaccinated birds (NFV) revealed less injury on the epithelial surface and a more rapid response to epithelial regeneration than the in only fumigated animals (FNV). The control group did not show remarkable morphologic changes. Postvaccinal and fumigation effects on the upper respiratory tract were temporary, whereas in lungs, increased emphysema, cartilage nodules in the interchange zone, and general lymphocyte infiltration had caused intensive injury.     

Ductus Epididymidis Compartments and Morphology of Epididymal Spermatozoa in Llamas

In this work, an attempt was made to asses possible regional specializations in the llama ductus epididymidis. According to histological and histochemical criteria, six segments (I-VI) were identified. Segment I was a short region where ductuli efferentes joined the ductus epididymidis. Segments II and III showed maximal epithelial height and mitotic activity, respectively, and weak LDH activity. Epithelial cells in segment IV contained PAS-positive, amylase and neuraminidase-resistant secretory granules. Segment V showed strong acid phosphatase and lactate dehydrogenase activities. Segment VI was characterized by moderate acid phosphatase and high lactate dehydrogenase activities, respectively, and by maximal spermatozoa packagement. Scanning electron microscopy of epidydimal spermatozoa revealed that cytoplasmic droplet translocation was accomplished at the distal part of the corpus epididymidis. Bent middle pieces characterized spermatozoa during droplet translocation.