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The ultrastructure of the interfacial zone which separates the intracellular structures of vesicular-arbuscular mycorrhizal fungi from host cytoplasm has been described in a variety of ways by recent investigators. Evidence is presented here which suggests that previous interpretations of the ultrastructure of the interfacial zone have been based on an artifact of fixation. Using an improved procedure, a dense, granular material was found in the interfacial zone. This material was preserved by simultaneous glutaraldehyde-osmium fixation but not by conventional prefixation and postfixation in glutaraldehyde and osmium, respectively.

Structural characteristics of aged (10 days) bovine longissimus and semitendinosus muscles as affected by thermal treatment were evaluated with scanning electron microscopy (SEM) and transmission electron microscopy PEM). Steaks were oven roasted at 177°C to internal temperatures of either 63, 68, or 73°C. At 63°C both muscle samples exhibited coagulation and denaturation of the perimy-sium and sarcolemma and progressively increased to near complete coagulation and denaturation at 73°C. Well-defined myofibrillar surface features were present in semitendinosus samples at 63°C and increased sarcomere denaturation and shrinkage were observed at the higher temperatures. Whereas, the overall topographical features of longissimus myofibrils were not well-defined and exhibited a granular appearance even at 63°C. TEM of samples heated to 63°C revealed less distinct myofibrils in longissimus than in semitendinosus samples. Disintegration of filaments in the I-band and shrinkage of filaments in the A-band occurred at 63°C. Increased disintegration of actin filaments in the I-band at the junction of the Z-disc and shrinkage and disruption of the A-band material occurred as temperatures were increased. Z-disc material remained intact with some evidence of disruption at the higher temperatures. Although progressive disruption of muscle fiber ultrastructure occurred as steaks were heated to higher internal temperatures, these changes did not result in increased muscle tenderness. Instead the samples became progressively less tender as internal temperatures were increased likely due to the shrinkage and hardening of filamentous material in the A-bands. Increased disintegration of filaments in the I-band as temperature was increased apparently did not contribute to an improvement in tenderness.

Sclerotial germination, hyphal growth pattern, and appressorial formation of the charcoal rot fungus, Macrophomina phaseolina (Tassi) Goid. on the surface of soybean roots, Glycine max (L.) Merrill was observed using scanning electron microscopy. Sclerotial germination is followed by a hyphal growth pattern which does not appear to be associated with any specific structural feature on the corrugated root surface. Appressoria are produced on the root surface at the tips of both primary hyphae and side branches within three days after inoculation.

Extract Auto-immune, haemolytic anacmias (AHA) of man (Dacie, 1963) and domestiicated animals (Schalm, 1965; Farrelly et al., 1966; Lapras and Oudar, 1971) are classified either as idiopathic or secondary to an underlying disease process (Pirofsky, 1969). In both categories antibodies active against the indivual's own erythrocytes are formed. These auto-antibodies are of two types being either warm or cold-acting. Warm-acting antibodies are most effective at 37°C, belong to the IgG class of immunoglobulins, and are incomplete in that, generally, they do not cause autohaemagglutination. Coldacting, or cryopathic, antibodies show maximum activitv at 4°C, are of the IgM immunoglobulin class and are capable of effecting autohaemagglutination. The two types of antibodies also differ in their prevalence. In man warm-acting antibodies occur infrequently and are always pathological (Dacie, 1963) while low titres of cold antibodies occur in most normal sera (Finland et al., 1945; Ellenhorn and Weiner, 195...

The measured reflections of lateral waves at discontinuities and boundaries are shown for two frequencies. A cylindrical model lithosphere bounded at its perimeter in seven distinct ways is utilized. The resulting fields are compared with the theory of normally incident lateral waves.

Plants of two soybean cultivars infected withGlomus mosseae were physiologically stressed by top removal and were harvested at seven bi-weekly intervals. Removing tops stopped root growth, stimulated branching, delayed plant growth stages by approximately two weeks, but did not affect spore production. Spore numbers were significantly related only to time of harvest. Pot variation in spore number was not significantly correlated with infection percentage or root dry weight. Harvest, cultivar, and cutting effects were highly significant for root and shoot weights and root/shoot ratios.

Procedures for sectioning fungal fructifications in host tissues or on artificial media are described, which allow observation of internal structures by scanning electron microscopy. Perithecia of Ceratocystis fimbriata and Phyllachora graminis, and telia of Puccinia xanthii showed excellent preservation of exposed structures in sections which were osmium-coated before being dried. While similar preservation was obtained in sectioned acervuli of Lecanosticta acicola and Marssonina juglandis and in pycnidia of Dothiorella ribis and Phomopsis occulta, the mucilaginous substances produced in these fructifications precluded observation of conidiophores. Extraction of mucilage from these sections was accomplished by periodic acid and dilute KOH treatments, followed by an osmium-coating procedure. In such preparations, mucilage was removed, internal structures were preserved, and pertinent characteristics of conidiogenous cells were resolved.

Phomopsis longicolla Hobbs, a causal agent of Phomopsis seed decay, colonizes the seed coats and embryos of mature soybean (Glycine max (L.) Merr.) seeds. The mode of infection of immature soybean pods and seeds by P. longicolla was examined using scanning electron microscopy. Phomopsis longicolla penetrated directly through pod walls by appressoria. Penetration through stomata in the pod surface was not observed. Immature seeds were also penetrated directly. Heavily infected immature seeds showed extensive colonization of the seed coats and embryos.

An ultrastructural investigation of seedling soybean root tissue infected by the charcoal rot fungus indicated that during the initial stages of pathogenesis, the fungus appears to be restricted mostly to the intercellular spaces and that penetration of interior cell walls occurred as a result of both mechanical pressure and chemical softening. Subsequently, the middle lamella disintegrates, the plasmalemma is separated from the cell wall, the cytoplasm becomes highly vesiculated and the mitochondria disorganized. In later stages of pathogenesis, the fungus becomes intracellular and recognizable cytoplasmic organelles disappear.

An intercellular matrix was observed to develop in normal cytoplasmic male-fertile corn lines infected by either race O or race T of Helminthosporium maydis. It usually occurred at the junction of necrotic and healthy cells but did not develop in infected Texas cytoplasmic male-sterile corn lines. Cytochemical tests indicated that the matrix was proteinaceous and ultrastructural examination showed that it was fibrous.

Mature conidia of race O and of race T of Helminthosporium maydis were examined microscopically to characterize the general ultrastructure of the conidia and to determine if the two races could be differentiated on the basis of conidial morphology. At the light-microscope level, the two races could not be separated. Histochemical analyses showed that, in both races, the cell wall was composed of chitin with melanin pigmentation. Electron-microscopic examination of thin-sectioned conidia revealed the presence of two distinct cell walls. Cross-walls were found to have typical ascomycetous septal pores. The types of cell organelles found in mature conidia did not provide any indication of the pathogenic capability of the fungus. No consistent differences were found in the ultrastructure of the two races and it was concluded that race T could not be differentiated from race O on the basis of conidial morphology.

This paper describes the development of a membrane-based process for dehumidifying the Extravehicular Mobility Unit (EMU). The membrane process promises to be smaller, lighter, and more energy efficient than the other technologies for dehumidification. The dehydration membranes were tested for 90 days at conditions expected to be present in the EMU. The results of these tests indicate that membrane-based technology can effectively control humidity in the EMU.

Human monocytes, pulmonary alveolar macrophages (PAMs) and spleen macrophages were concentrated by immobilization on cold insoluble globulins. These cell preparations were 90 +/- 3%, 95 +/- 1% and 83 +/- 3% esterase rich, respectively, 87 +/- 4%, 95 +/- 3% and 66 +/- 11% phagocytic and 78 +/- 3%, 79 +/- 9% and 68 +/- 5% reactive with OKM1 monoclonal antibody. Spleen macrophages differed from the other two cell preparations in that significantly fewer reacted with 61D3 or 63D2 monoclonal antibodies. Monocytes and PAMs promoted the mixed leucocyte response by autologous lymphocytes when added at low concentrations, but suppressed this response at high concentrations. Spleen macrophages only promoted the mixed leucocyte reaction but were required in much higher numbers than either monocytes or PAMs for optimal promotion. Likewise, the added presence of monocytes or PAMs in high numbers suppressed Ig synthesis stimulated with pokeweed mitogen, while spleen macrophages were not suppressive in this system. This study shows that the distribution of macrophages that differ in their regulatory effects upon lymphocyte responses varies in different tissues. The human spleen is deficient in macrophage related suppression.

Human synovial tissues have been assayed for the production of cartilage degrading activity (CDA). This activity is thought to be homologous with catabolin/interleukin 1 (IL1) produced by porcine synovium and leucocytes and by human leucocytes. The CDA of 26 rheumatoid (RA) and 41 non-rheumatoid synovia was measured on a dry weight basis. The rheumatoid synovia showed a threefold increase in activity over the non-rheumatoid, but there was no significant overall difference on a deoxyribonucleic acid (DNA) basis. The rheumatoid synovia appeared to consist of two populations; in over half the samples CDA was not related to cellularity, but eight patients had a high CDA and a high cellularity.

Scanning electron stereoscopy and transmission electron microscopy were used to correlate morphological alterations and cytological phenomena associated with deterioration of arbuscules in yellow poplar mycorrhizae. Arbuscular degradation was initiated at the tips of the finest branches and progressed basipetally. Cytoplasm in arbuscular hyphae progressively deteriorated and was followed by collapse of the fungal walls. Degraded portions of the arbuscules aggregated into clumps comprised of host wall material and the distorted fungal walls. Host nuclei, abundant mitochondria, and proplastids were closely associated with arbuscular branches undergoing cytoplasmic deterioration and with clumped portions of the arbuscule which contained degraded hyphal branches. Most of the arbuscules observed had deteriorated to the clumped stage. Some cortical cells contained several clumped arbuscules and nearly mature, intact arbuscules which indicated that reinfection occurs even as degradative phenomena are in progress. It is suggested that substantial quantities of mineral nutrients may be made available to the host via degradation of fungal cytoplasm in the arbuscular hyphae preceding aggregation of degraded hyphae into discrete clumps.

The interaction of divalent and trivalent metal cations, ferricyanide, a lipophilic ion (tetraphenylborate), and a local anesthetic (tetracaine) with the phosphocholine head group of egg lecithin was investigated by using wide-line 14N and 31P NMR. Measurements of the 14N quadrupolar splittings in the presence of a variety of perturbing agents demonstrated that the 14N NMR technique can be used to directly monitor ion or anesthetic binding. The 14N quadrupolar splitting (delta nu Q) is a measure of the order parameter of the C beta-N bond segment, and changes in delta nu Q as large as 3.5 kHz were observed. Moreover, a comparison of the changes in the quadrupolar splittings induced by the binding of ions or anesthetics provided a sensitive method of discriminating between these perturbing agents in their ability to alter the orientational order of the C beta-N bond segment of the phosphocholine moiety. Without exception, addition of metal ions or anesthetics always resulted in a decrease of the 14N delta nu Q. This reduction reflects a change in the average orientation or degree of motional averaging at the C beta-N bond segment position. In the case of metal ion binding, the strength of the interaction increased with the charge of the metal ion in the order Ca2+ less than Ln3+, in agreement with a previous 2H NMR study [Akutsu, H.,Seelig, J. (1981) Biochemistry 20, 7366-7373].(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular requirements for induction of primary proliferative responses by human T cells to trinitrophenylated autologous stimulators have been characterized. Substantial proliferative responses were observed with each of the Ia+ stimulator populations tested. Nevertheless, major differences in the hapten specificity of such responses were observed. Thus purified macrophages/monocytes (M phi) when TNP-modified induced responses that were relatively modest in absolute magnitude, but were highly hapten specific. This reflected the very limited capacity of purified M phi to induce proliferation when unmodified, i.e., an autologous mixed leukocyte response (AMLR). In contrast, unmodified M phi-depleted B plus null cells were potent stimulators of AMLR, but hapten modification did not significantly enhance the responses induced by these cells. Moreover, when M phi were added to B plus null cell stimulators AMLR responses were reduced and, with TNP-modified stimulators, hapten-specific responses were restored. The data thus suggest that M phi may have important roles in induction of primary T cell responses to conventional antigens but function largely as regulators rather than stimulators of AMLR. Finally, we have introduced a novel antigen-presenting cell population, the irradiated Ia+ TNP-specific cloned T cell. The possibility that such cells may utilize autostimulatory positive feedback circuits for activation of naive T cells and in interactions between subpopulations of hapten-reactive T cells is discussed.

Isolates of Phakopsora pachyrhizi from Australia, Indian, the Philippines, Taiwan, and Puerto Rico were compared with respect to morphology and development of 'Wayne' soybean. The most extensive comparisons were made between the Puerto Rican and Taiwanese isolates; these were indistinguishable in their prepenetration, penetration, and early colonization phases. Examination of uredia of all isolates by light and scanning electron microscopy (SEM) revealed no differences in uredial morphology. All isolates were indistinguishable with respect to uredospore size, shape, and apparently the number and distribution of uredospore germ pores. The only difference observed was the appearance of germ pores; germ pores of the Puerto Rican isolate were easier to see by means of SEM than those of the four Eastern Hemisphere isolates, suggesting that the Puerto Rican isolate may have thinner germ pore plugs. This difference is not sufficient to consider the isolates as taxonomically distinct.

To investigate mechanisms by which antigen, macrophages, and interleukin 2 (IL2) participate in the induction of secondary T-cell proliferative responses, trinitrophenyl (TNP) was presented in three distinct modes: (i) TNP-modified peripheral blood mononuclear cells (TNP-PBMC), (ii) TNP-PBMC cell sonicates, and (iii) TNP-ovalbumin (TNP-OVA). Stimulators were depleted of Mac-120+ macrophages using Mac-120 monoclonal antibody plus complement. TNP-Mac-120 macrophages stimulated primed T cells nearly as well as TNP-unfractionated macrophages (which were about 40% Mac-120+). In contrast, although greater than 70% DR+, Mac-120- macrophages plus either TNP-OVA or TNP-PBMC sonicate elicited minimal responses compared to unfractionated macrophages plus antigen. After 21-28 days of in vitro priming, macrophage-depleted T cells were not stimulated to proliferate by either IL2 alone or sonicates alone. IL2 plus TNP-PBMC sonicates, however, stimulated significant proliferation. Furthermore, this response was considerably greater than that to IL2 plus either TNP-T cell sonicates or TNP-mouse spleen sonicates. Thus, the Mac-120+ macrophage population may have an important antigen-presenting and/or accessory function in the stimulation of primed T cells by soluble or particulate antigen, although it is unnecessary for responses to intact TNP-Ia+ PBMC. In addition, the data suggest that Ia+ sonicates alone may suffice for induction of IL2 responsiveness, but not for endogenous IL2 production and subsequent proliferation by primed T cells.

Coronary artery disease due to atherosclerosis takes the lives of approximately 550,000 Americans each year--an enormous toll. Put in economic terms, the cost to the United States alone has been estimated to exceed 60 billion dollars annually. We have found that well-resolved proton (1H) NMR spectra can be obtained from human atheroma (fatty plaque), despite its macroscopic solid appearance. The fraction of the total spectral intensity corresponding to the sharp 1H NMR signals is temperature dependent and approaches unity at body temperature (37 degrees C). Studies of the total lipids extracted from atheroma and cholesteryl esters were conducted to identify the chemical and physical origin of the spectral signature. The samples were characterized through assignment of their chemical shifts and by measurement of their T1 and T2 relaxation times as a function of magnetic field strength. The results suggest that the relatively sharp 1H NMR signals from human atheroma (excluding water) are due to a mixture of cholesteryl esters, whose liquid-crystalline to isotropic fluid phase transition is near body temperature. Preliminary applications to NMR imaging of human atheroma are reported, which demonstrate early fatty plaque formation within the wall of the aorta. These findings offer a basis for noninvasive imaging by NMR to monitor early and potentially reversible stages of human atherogenesis.