In vitro superoxide activity in the haemolymph of the West Indian leaf cockroach,Blaberus discoidalis

The respiratory burst is an NADPH oxidase-driven reduction of molecular oxygen to superoxide, which can occur in phagocytic cells as part of an antimicrobial defence, and is well documented among the vertebrates. This paper describes a process resembling the respiratory burst, which occurs in the haemolymph and haemocytes of the cockroach, Blaberus discoidalis. The in vitro reduction of nitroblue tetrazolium by superoxide to formazan was measured spectrophotometrically in B. discoidalis haemolymph in response to various immune elicitors. Nitroblue tetrazolium reduction was partly impeded in the presence of superoxide dismutase, a specific antioxidant which converts superoxide to hydrogen peroxide, as well as by chemicals known to inhibit the respiratory burst in vertebrates (trifluoperazine, diphenylene iodonium, and N-ethylmaleimide). This suggests the generation of superoxide anions by haemolymph as part of an immune response. Furthermore, formazan staining of elicitor-treated haemocytes was observed microscopically, with less intense staining in the presence of superoxide dismutase. Finally, respiratory burst inhibitors and superoxide dismutase enhanced the growth of E. coli incubated in whole haemolymph, implying a role for haemolymph-derived superoxide in antibacterial defence.     

Tissue distribution of migration inhibitory factor and inducible nitric oxide synthase in falciparum malaria and sepsis in African children

Background

The inflammatory nature of falciparum malaria has been acknowledged since increased circulating levels of tumour necrosis factor (TNF) were first measured, but precisely where the mediators downstream from this prototype inflammatory mediator are generated has not been investigated. Here we report on the cellular distribution, by immunohistochemistry, of migration inhibitory factor (MIF) and inducible nitric oxide synthase (iNOS) in this disease, and in sepsis.

Methods

We stained for MIF and iNOS in tissues collected during 44 paediatric autopsies in Blantyre, Malawi. These comprised 42 acutely ill comatose patients, 32 of whom were diagnosed clinically as cerebral malaria and the other 10 as non-malarial diseases. Another 2 were non-malarial, non-comatose deaths. Other control tissues were from Australian adults.

Results

Of the 32 clinically diagnosed cerebral malaria cases, 11 had negligible histological change in the brain, and no or scanty intravascular sequestration of parasitised erythrocytes, another 7 had no histological changes in the brain, but sequestered parasitised erythrocytes were present (usually dense), and the remaining 14 brains showed micro-haemorrhages and intravascular mononuclear cell accumulations, plus sequestered parasitised erythrocytes. The vascular walls of the latter group stained most strongly for iNOS. Vascular wall iNOS staining was usually of low intensity in the second group (7 brains) and was virtually absent from the cerebral vascular walls of 8 of the 10 comatose patients without malaria, and also from control brains. The chest wall was chosen as a typical non-cerebral site encompassing a range of tissues of interest. Here pronounced iNOS staining in vascular wall and skeletal muscle was present in some 50% of the children in all groups, including septic meningitis, irrespective of the degree of staining in cerebral vascular walls. Parasites or malarial pigment were rare to absent in all chest wall sections. While MIF was common in chest wall vessels, usually in association with iNOS, it was absent in brain vessels.

Conclusions

These results agree with the view that clinically diagnosed cerebral malaria in African children is a collection of overlapping syndromes acting through different organ systems, with several mechanisms, not necessarily associated with cerebral vascular inflammation and damage, combining to cause death.     

Structure, function, and motility of vacuoles in filamentous fungi

Current information on the structure and function of motile tubular vacuoles in Pisolithus tinctorius and other fungi is reviewed. The use of fluorochromes to label the vacuole lumen is evaluated and observations on the structure and motility of vacuoles in P. tinctorius are differentiated from possible artifacts. The styryl dyes FM4-64 and MDY-64, used in yeast to demonstrate endocytosis, show little or no labeling of internal membranes in undamaged P. tinctorius cells. This agrees with our data showing that other probes for endocytosis such as Lucifer yellow CH are not taken up by hyphal tip cells. Overall, the observations do not support endocytosis in hyphal tips. It has been suggested that tubular vacuole systems carry out longitudinal transport, and evidence in favor of this hypothesis is evaluated. New data are presented to show that many of the large vacuoles in subapical cells are attached to the plasma membrane and are relatively immobile, while video sequences show movement of fluorochrome in pulses along a series of several large vacuoles, all interconnected via tubules. Tubular vacuoles from thick sections of hyphae processed under anhydrous conditions are shown by X-ray microanalysis to contain relatively high levels of P and K, as seen previously in the larger vacuoles. These results provide further evidence for a role of the tubular vacuoles in longitudinal transport of P. Copyright 1998 Academic Press.     

Rapid and sensitive GC/MS characterization of glycolipid released Galalpha1,3Gal-terminated oligosaccharides from small organ specimens of a single pig

Pig to human xenotransplantation is considered a possible solution to the prevailing chronic lack of human donor organs for allotransplantation. The Galalpha1,3Gal determinant is the major porcine xenogeneic epitope causing hyperacute rejection following human antibody binding and complement activation. In order to characterize the tissue distribution of Galalpha1,3Gal-containing and blood group- type glycosphingolipids in pig, acid and nonacid glycosphingolipids were isolated from the kidney, small intestine, spleen, salivary gland, liver, and heart of a single pig obtained from a semi-inbred strain homozygous at the SLA locus. Glycolipids were analyzed by thin-layer immunostaining using monoclonal antibodies, and following ceramide glycanase cleavage as permethylated oligosaccharides by gas chromatography, gas chromatography-mass spectrometry, and matrix- assisted laser desorption/ionization mass spectrometry. The kidney contained large amounts of Galalpha1,3Gal-containing penta- and hexasaccharides having carbohydrate sequences consistent with the Galalpha1,3nLc4and Galalpha1,3Lexstructures, respectively. The former structure was tentatively identified in all organs by GC/MS. The presence of extended Galalpha1,3Gal-terminated structures in the kidney and heart was suggested by antibody binding, and GC/MS indicated the presence of a Galalpha1,3nLc6structure in the heart. The kidney, spleen, and heart contained blood group H pentaglycosylceramides based on type 1 (H-5-1) and type 2 (H-5-2) chains, and H hexaglycosylceramides based on the type 4 chain (H-6-4). In the intestine H-5-1 and H-6-4 were expressed, in the salivary gland H-5-1 and H-5-2, whereas only the H-5-1 structure was identified in the liver. Blood group A structures were identified in the salivary gland and the heart by antibody binding and GC/MS, indicating an organ- specific expression of blood group AH antigens in the pig.      

Ecological Imagery and Cultural Adaptability: The Canelos Quichua of Eastern Ecuador

Ecological imagery among the Upper Amazonian Canelos Quichua native peoples of eastern Ecuador provides a paradigmatic, symbolic template organized by sets of cosmological premises. This template, anchored by traditional shamanism and ceramic manufacture, is invoked in emotionally charged ceremonial and juropolitical contexts to express resistance to normative culture bearers who have a potential or real impact on the ecosystem and indigenous political economy. The imagery is described as it exists within a system of radical change. Mechanisms are discussed whereby ecosystem knowledge and social structure are systemically linked to cosmological premises within a dynamic system of indigenous cultural adaptability . [Ecuador, symbolism of Canelos Quichua, Amazonian cosmology, cultural adaptability, ecological imagery]     

Gonadal development in hermaphrodite mice

Summary The genetic background and morphology of spontaneous mosaic hermaphrodites of mice have been described. Presented in the formal symposium on Sexual Differentiation in Vitro and in Vivo at the 29th Annual Meeting of the Tissue Culture Association, Denver, Colorado, June 4–8. 1978. This work was supported by Grant HD 04083 from the National Institute of Child Health and Human Development.     

Reproduction in free-ranging Propithecus verreauxi: Estrus and the relationship between multiple partner matings and fertilization

Female sifaka mate selectively with one or more resident and/or non-resident males during the breeding season. Various adaptive explanations have been advanced to explain why female primates mate with multiple males including that 1) females seek to confuse paternity and thereby forestall male infanticide and/or ensure male infant care or 2) females seek to ensure fertilization. Assessing the power of fertilization insurance to explain mating patterns in females requires information on the temporal relationship between mating and ovarian hormones. The hormonal correlates of reproduction and mating in free-ranging Propithecus verreauxi were investigated using excreted steroids as indices of reproductive state. Solid-phase extraction and radioimmunoassay techniques were used to measure unconjugated estradiol (E₃) and progesterone (P₄) in 485 desiccated fecal samples collected from five female sifaka before and during the breeding season at Beza Mahafaly, Madagascar. Results suggest that behavioral estrus was characterized by 10- to 15-day elevations in E₂; hormonal activity was observed to be similar to pseudo-estrus reported for other lemur species; apparent conception was associated with sustained P₄ elevations beginning 1 to 3 days post-estrus with gestational phase elevations of E₂ beginning 42 to 45 days post-conception; and mating with multiple partners appeared not to be a prerequisite to fertilization, as conception resulted from both monoandrous and polyandrous matings. These preliminary data suggest that fertilization insurance is not adequate to explain polyandrous mating in sifaka at Beza Mahafaly. © 1996 Wiley-Liss, Inc.