Histopathology and histochemistry of a focus of staphylococcal infection in a sensitized body (material concerning pathogenesis)]

Rabbits were sensitized with a killed St. aureus culture (alpha-toxigenic 0-15 strain); one week later the were infected intradermally with a virulent leukocidin-active St. aureus V8 or with the 0-15 strain. A hyperegic inflammation with the signs of reaction observed in hypersensitivity of delayed type was revealed at the site of infection in 24 hours. On the seond day this process was supervened by an intensive leukocytic infiltration characteristic of this infection, with the subsequent suppuration. Beginning from the earliest stages of the process and up to its decline the inflammatory exudate displayed hyaluronic and sialic acids; they could perform functions of the nonspecific immunity factors in the focus. It was revealed at the terminal stage of the process that the organism did not react by the inflammatory reaction to the presence of the microbes remaining near the focus. Consequently, the tolerance of the organism to the microbe was revealed; this tolerance was possibly conditioned by the presence of sialic acids in the focus. Leukocytes with the phagocytized microbes appeared in the veins nearest to the focus. Histochemical shifts in the focus can be the cause of the incompleteness of phagocytosis. The tropism of staphylococci of the V8 strain to the collagen fibers was revealed.     

Microscopic Anatomy and Ultrastructure of a Polian Vessel in the Sipunculan Thysanocardia nigra Ikeda, 1904 from the Sea of Japan

The microscopic anatomy and ultrastructure of a Polian vessel have been studied in the sipunculan Thysanocardia nigra Ikeda, 1904 from the Sea of Japan using the methods of histology and electron microscopy. We describe ultrastructural features of the inner and outer coelothelium, which is constructed of podocytes and multiciliary cells. Between the processes of the podocyte cells, we found double diaphragms that are considered characteristic macromolecular filters. We conclude from an analysis of the ultrastructural features of the vessel wall that coelomic fluid may be filtered from the tentacular coelom to the trunk coelom via the wall of the Polian vessel.     

Chemical biology: Paper alert

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in chemical biology.     

The gametogenesis and sexual cycle of the bivalve Corbicula japonica Prime (1864) in the mouth of the Kievka River (Sea of Japan)

Oogenesis, spermatogenesis, and the sexual cycle of the bivalve Corbicula japonica in the estuary of the Kievka River (Primorye, Sea of Japan) were studied. The stages of development of germ cells and the role of auxiliary cells in gonads during vitellogenesis were described. The features of sperm morphology were recorded. It was shown that the reproductive cycle in C. japonica is determined by the water temperature, that gametogenesis starts at the boundary between April and May, that spawning occurs from mid-July to mid-September, and that gonads are in a stage of relative sexual inactivity in the autumn and winter.     

Cryptic species in Pacific sipunculans (Sipuncula: Phascolosomatidae): east‐west divergence between non‐sister taxa

Cryptic diversity, i.e. diversity observable in genetic but not in morphological traits, is prevalent in marine invertebrates and presents one of the greatest obstacles to obtaining accurate estimates of species richness. Sipunculans, commonly called peanut worms, are marine annelids in which high levels of cryptic diversity have previously been documented. In this study, we use genetic identification techniques to examine divergence of two lineages of Pacific sipunculans, both known under the name Phascolosoma agassizii. One lineage is isolated to the eastern Pacific coast while the other one inhabits the western Pacific coast. These clades are reciprocally monophyletic and are not recovered as sister taxa, suggesting relatively early divergence within Phascolosoma. Furthermore, we did not find support for a genetic distinction between the western Pacific Phascolosoma agassizii agassizii and Phascolosoma agassizii kurilense, a subspecies reported from the Kuril Islands. Considering that the type locality for P. agassizii is in the Eastern Pacific, we suggest that the western clade, including the samples from the Kuril islands, represent a new, undescribed species.     

Acclimation or stress symptom? An integrated study of intraspecific variation in the clonal plant Aechmea bromeliifolia,a widespread CAM tank‐bromeliad

The clonal tank-bromeliad Aechmea bromeliifolia (Rudge) Baker was found in four different habitats in a restinga (vegetation mosaic on sandy coastal plains), of south-eastern Brazil. These habitats (swamp forest, dry forest, dry shrubland and herbaceous marsh) lie within a few hundred metres of each other along a gradient extending inland from the coast, and differ markedly in terms of light and flood regime. We compared ramet morphology, leaf anatomy and physiology, and population parameters to examine the amplitude of trait variation of this widespread species in the studied restinga. This integrated approach allowed us to examine which variation conferred acclimation and which was merely a stress symptom. A . bromeliifolia showed site-specific differences in abundance, distribution, rosette size and shape, leaf anatomical arrangement and photochemical efficiency (potential quantum yield; F _v/ F _m) during the day. Most of the variation found seemed to be related to the interaction of light and flooding. The lowest number and size of ramets at the exposed, dry shrubland was matched by a marked leaf photoinhibition, which suggested poor acclimation to local levels of light intensity and limited water supply. In the other habitats, the morpho-physiological parameters measured suggested adequate foraging behaviour and site acclimation.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 140 , 391-401.