Neutrophilic nodules in the intestinal walls of Japanese monkeys associated with the neutrophil chemotactic activity of larval extracts and secretions of Oesophagostomum aculeatum

High neutrophil chemotactic activity was detected in the culture medium from Oesophagostomum aculeatum larvae in vitro using blind-well chambers with Millipore filters, and guinea pig leucocytes as indicator cells. Neutrophil chemotactic activity was also detected in the extract from larval worms in a dose dependent fashion. This activity was detected in the low molecular weight fractions adjacent to a sodium chloride marker by gel filtration on Sephadex G200. These results were further confirmed with monkey neutrophils. The possible role of this activity in the formation of granulomatous lesions rich in neutrophils found in O aculeatum infections in the Japanese monkey is discussed.     

Duration of maternally derived antibodies against equine influenza in newborn foals

Serum antibody concentrations against influenza A-equi-1 virus and A-equi-2 virus were measured in a group of 18 foals from birth to 4 months of age. More than 50% of the foals were seronegative to A-equi-1 virus infection by 4 weeks of age, with titers of less than or equal to 1:16. For A-equi-2 virus, more than 50% of the foals were seronegative by 2 weeks of age, with titers of less than or equal to 1:8. Passively derived antibodies against influenza A-equi-1 virus and A-equi-2 virus in foals obtained from recently vaccinated mares and from mares not vaccinated within 6 months before foaling were low in titer. The duration of passively derived antibodies was also short-lived.     

Ultrastructure of goat testes: tubulobulbar complexes between spermatids and Sertoli cells

The fine structure of tubulobulbar complex (TBC) of goat seminiferous epithelium was studied using testicular samples fixed by perfusion. During the maturation phase of the spermatid, the TBC appeared on the periphery of the head before spermiation, dorsal and ventral parts of the head, both sides of the acrosome and on the postnuclear sheath region. At an early stage of the development of the TBC, a partial loss of smooth endoplasmic reticulum in the ectoplasmic specialization of a neighboring Sertoli cell was observed; filament bundles disappeared and a small fragmented smooth endoplasmic reticulum was left. Subsequently, a spermatid vesicle (coated vesicle) expanded to be in contact with the Sertoli cytoplasm by a small channel. These tubular projections extended to form a bulbous balloon-like structure forming sometimes a bi-balloon appearance, until torn off from the spermatid into the Sertoli cytoplasm and probably digested by the Sertoli cell. The significance of this structural development was morphologically discussed.     

Poxvirus infection in Nile crocodiles (Crocodylus niloticus)

An outbreak was encountered of numerous yellowish cutaneous nodules in one- to two-year-old farmed Nile crocodiles (Crocodylus niloticus) in Kasaba Bay Crocodile Farm at Lake Tanganyika in Zambia during 1988. Out of 4000 crocodiles of different age groups, 300 yearlings were affected and 82 of those affected died. The lesions were prominent on the head, especially around the eyelids, the nostrils, both sides of the mouth, ventral neck, ventral pale belly, limbs and the root of the tail. Histologically, the epidermal lesions revealed large focal areas of marked acanthosis accompanied by hyperkeratosis and parakeratosis. In the prickle cells, there were multiple small neutrophilic granular inclusions and large eosinophilic homogeneous cytoplasmic inclusions. Electron microscopically, there were numerous poxvirus particles and matrices in the cytoplasm of many prickle cells. Dark blue homogeneous cytoplasmic inclusions in toluidine blue sections consisted of an electron opaque matrix with mature viral particles (160 x 200 x 230 nm). Furthermore, there were clumps of granular matrix containing immature viral particles (200 x 399 nm) in the cytoplasm. Various features of viral developing processes were observed.     

Inoculum levels ofVerticillium dahliae in the soils of the hot semi-arid negev region of Israel

In the Negev area,Verticillium dahliae Kleb. produces 50 times more microsclerotia (MS) on potato plants harvested in the winter than on those harvested in the summer. Number and distribution of viable fungal units, subsequent to incorporation of infected potato plants and during a sequence of non-susceptible hosts, were estimated in February of the following years by counting fungal units in four sublayers: 0–10, 10–20, 20–30 and 30–40 cm. Inoculum density ofV. dahliae was the highest in the top layer, decreasing to the deepest sublayer. Reduction of population density of viableV. dahliae units was less in the field than in the laboratory. No viable units were detected after 5 years of storage in the laboratory, whereas 4% of the original population remained viable after 7 years of crop rotation. Although crop rotation did not control the fungus completely, it did reduce inoculum density markedly.