Single-photon emission computed tomography in distal field hypoperfusion

To assess the ability of technetium-99m hexamethylpropyleneamineoxime single-photon emission computed tomography (SPECT) imaging to differentiate distal field hypoperfusion from other stroke mechanisms, 24 patients with acute cerebral ischemia were studied. SPECT scans were read by two physicians according to a preestablished set of criteria for distal field hypoperfusion. SPECT patterns read as "probable" or "definite" for distal field hypoperfusion were found in 42% (10/24); of these, 80% (8/10) had ipsilateral carotid occlusion or high-grade stenosis. Severe carotid stenosis was found in 43% (6/14) with SPECT scans negative for distal field hypoperfusion (Fisher exact test [1-tailed] p = 0.0796). The results suggest that a distal field hypoperfusion pattern on SPECT may identify patients with hemodynamically significant large vessel disease.

SPECT in patients with epilepsia partialis continua

We report 2 patients with epilepsia partialis continua (EPC) in whom ictal single photon emission computed tomography (SPECT) showed focal increased signal while EEG failed to show epileptic changes. SPECT may clarify confusing situations when EPC is suspected.

Structure of a modified cytosine: an antiviral nucleoside analog, homo-Ara-C

Homo-Ara-C [5'-(hydroxymethyl)-5'-deoxy-1-beta-D-arabinofuranosyl-3H- cytosine], C10H16N3O5, Mr = 258.25, P2,2,2, a = 8.261 (2), b = 19.644 (4), c = 6.993 (6) A, V = 1134.8 A3, Z = 4, Dx = 1.511 g cm-3, lambda (Cu Ka) = 1.5418 A, mu = 10.5 cm-1, F(000) = 548, T = 288 K, final R = 0.053 for 1189 observed reflections. Conformational features of the nucleoside include a glycosidic bond conformation in the anti range, a ribose moiety in the 2E [C(2')-endo] form like 5'-N3-Ara-C, 5-NO2-Ara-U and Ara-C and a C(5')-C(6') bond that is gauche to C(4')-O(4') but trans to C(4')-C(3').

Azarcón por empacho--another cause of lead toxicity

A new source of toxic lead ingestion has been identified roentgenologically in Mexican-American children and adults. Azarcón is an orange powder that contains 86% to 95% lead tetroxide (Pb3O4). At least three children have been treated with this substance by folk healers for relief of abdominal symptoms. Other Hispanic medical folklores may include this toxic "remedy."

Differentiation of posterior pararenal space infection from psoas abscess by gallium imaging

Three of four patients whose cases fit the clinical description of psoas abscess proved on gallium imaging to have infection in the posterior pararenal space sparing the psoas muscle. This space provides a route for spread of infection connecting the spine, the anterior abdominal wall, the scrotum, the anterior thigh, and the gluteal region as demonstrated by the cases presented. Clinical differentiation between posterior pararenal space infection and psoas abscesses is difficult and CT studies may not demonstrate the process when the psoas space is not involved.

A monoclonal antiidiotypic antibody to MOPC 315 IgA inhibits the growth of MOPC 315 myeloma cells in vitro

Spleen cells from BALB/c mice immunized with MOPC 315 IgA were fused with P3X63/Ag8 myeloma cells. Hybrid clones were screened for antibody production by a plate-binding radioimmunoassay in which MOPC 315 IgA was reacted with culture supernatants and 125I-protein A. One antibody-producing hybridoma clone (D10) was selected and injected i.p. into BALB/c mice. Ascitic fluid of tum or-bearing animals reacted specifically with MOPC 315 IgA and the reaction was inhibited by DNP- aminocaproic acid, indicating that the monoclonal antibody was directed against the hapten-binding site of MOPC 315 IgA. The monoclonal antiidiotypic antibody was of the complement (C)-binding IgG2a subclass and inhibited IgA production and growth of MOPC 315 cells in vitro in the presence of guinea pig C, as assessed by inhibition of formation of plaques and colonies by MOPC 315 cells in agar.

A monoclonal antiidiotypic antibody to MOPC 315 IgA inhibits the growth of MOPC 315 myeloma cells in vitro

Spleen cells from BALB/c mice immunized with MOPC 315 IgA were fused with P3X63/Ag8 myeloma cells. Hybrid clones were screened for antibody production by a plate-binding radioimmunoassay in which MOPC 315 IgA was reacted with culture supernatants and 125I-protein A. One antibody-producing hybridoma clone (D10) was selected and injected i.p. into BALB/c mice. Ascitic fluid of tum or-bearing animals reacted specifically with MOPC 315 IgA and the reaction was inhibited by DNP- aminocaproic acid, indicating that the monoclonal antibody was directed against the hapten-binding site of MOPC 315 IgA. The monoclonal antiidiotypic antibody was of the complement (C)-binding IgG2a subclass and inhibited IgA production and growth of MOPC 315 cells in vitro in the presence of guinea pig C, as assessed by inhibition of formation of plaques and colonies by MOPC 315 cells in agar.

Induction of cytotoxic factors by immunization of mice with Freund's adjuvant components

Antiidiotypic antibody (AIA) was raised in mice by immunization with MOPC 315 immunoglobulin A emulsified in Freund's adjuvant (FA). The antibody content of mouse serum was assessed by (a) its ability to inhibit rosetting of 2,4,6-trinitro-phenyl-sheep red blood cells around MOPC 315 myeloma cells, and (b) by a solid phase antigen-binding plate assay based on reactivity with 125I-Protein A and inhibition in the presence of dinitrophenyl aminocaproic acid. FA was necessary for the production of AIA to MOPC 315 immunoglobulin A. Some of the AIA-containing mouse sera were cytotoxic for MOPC 315 cells in the presence of guinea pig complement. However, cytotoxicity was not correlated with amount of AIA, as assessed by inhibition of rosette formation, nor was it specific for myeloma cells bearing the MOPC 315 idiotype. Furthermore, cytotoxicity could also be generated by immunization of mice with complete Freund's adjuvant, incomplete Freund's adjuvant, or the muramyl dipeptide portion of mycobacteria, all in the absence of MOPC 315 immunoglobulin A. Therefore, the complement-dependent cytotoxic antibodies in the AIA-containing antisera, which belonged to the immunoglobulin G and M classes, were likely directed against some component of FA. Myeloma cells which were not killed by anti-FA antiserum, as assessed by dye exclusion, were inhibited in their ability to secrete immunoglobulin and to form clones in agar.

In vitro growth of wheat and flax rust fungi on complex and chemically defined media

Growth from uredospores seeded in axenic culture is described for several races of Puccinia graminis Pers. f. sp. tritici (Erikss. and Henn.) and race 3 of Melampsora lini (Ehrenb.) Lév. on complex media containing peptone, yeast extract, and bovine serum albumin (BSA); and for an Australian isolate of Puccinia graminis, race 126-ANZ 6,7, and Melampsora lini, race 3, on chemically defined, liquid media.Of six North American isolates of Puccinia graminis only race 38 formed colonies approaching those of race 126-ANZ 6,7 in final size and general morphology on complex media. 5′AMP had no effect on the growth of 126-ANZ 6,7, but cyclic AMP inhibited growth after uredospore germination. Good growth and sporulation were obtained with 126-ANZ 6,7, but not with the other isolates tested, using a new, chemically defined liquid medium, sterilized by millipore filtration, and containing glucose, Czapek's minerals plus micronutrients, Ca2+, glucose and aspartic acid, glutathione, and cysteine. Uredospores produced in culture reinfected exposed mesophyll tissue, but not intact seedling leaves of wheat.Highly reproducible growth and sporulation of Melampsora lini, race 3, were obtained routinely on a solid medium containing Difco-Bacto agar, sucrose, Knop's minerals, micronutrients, yeast extract, peptone, and BSA. Vegetative cultures, capable of reinfecting the cut ends of surface-sterilized flax cotyledons, could be maintained indefinitely by subdivision before sporulation and transfer to the same medium minus BSA. Evidence is presented that BSA stimulated the development of colonies and the formation of uredospores. The mode of action of BSA is unknown, but it could not be replaced by putrescine.A new chemically defined, liquid medium containing sucrose, Knop's mineral salts, micronutrients, aspartic (or glutamic) acid, and cysteine supported the growth of colonies of Melampsora lini in a highly reproducible manner. The formation of uredospores and teliospores by these colonies was controlled by (a) the level of Ca2+ (as Ca(NO3)2∙4H2O), (b) the concentration of aspartic acid, and (c) the number of colonies per flask. At inoculum levels giving 40 to 60 colonies per flask, in media containing 8.5 mM Ca+ and 45 mM aspartic acid, uredospore formation occurred in 60 to 70% of the colonies. A decrease in the Ca2+ level to 4.25 mM, or a decrease in aspartic acid to 22.5 mM, or adjustment of the inoculum level to give about 10 colonies per flask each resulted in only infrequent sporulation. The uredospores produced in vitro infected intact, 1-week-old flax cotyledons in a normal manner.

Sporulation and pathogenicity of an Australian isolate of wheat rust grown in vitro

Colonies of Puccinia graminis Pers. f. sp. tritici Erikss. & Henn., race ANZ 126-6,7 were grown from uredospores on Czapek's mineral salts, 3% glucose, 0.1% Evans' peptone, plus defatted bovine serum albumen. Dikaryotic vegetative hyphae apparently developed from centers of germ tube anastomosis, without the formation of typical infection structures. Typical pigmented uredospores and teliospores were formed after 6 to 8 weeks growth. Both spore forms were coated with a layer of material which was visible under the scanning electron microscope and was not observed on uredospores grown on intact wheat leaves. The uredospores were capable of infecting the mesophyll of wheat leaves exposed by stripping back the lower epidermis. The possibility is considered that the surface coating of uredospores grown in vitro is related to their inability to infect intact leaves via the stomata.

In vitro culture of the flax rust, Melampsora lini

Two different strains of Melampsora lini (Pers.) Lév. were grown on media similar to those described by Turel (Can. J. Bot. 47: 821–823). Alterations in organic and inorganic constituents did not, in general, prevent growth. Peptone and yeast extract, singly or in combination, supported growth, but coconut milk did not. Maintenance of the ambient temperature below 17 °C during transfer procedures increased the number of colonies which grew. The mycelium was generally binucleate. Spore-like cells of varying shapes were found, some of which resembled uredospores and teliospores.

Erythrocyte Life Span And Sequestration Studies With 51chromium in Kala-azar

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In vitro growth of gelatin suspensions of uredospores of Puccinia graminis f. sp. tritici

A comparison was made of the growth of the Australian isolate of Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn. race ANZ 126-6,7 on 1.5% Difco Bacto-Agar using water and 15% gelatin as suspension media for seeding uredospores on the media. A range of media was tested, the basic constituents being 3% glucose, Czapek's minerals, peptone, and 1% bovine serum albumin. Spores embedded in gelatin gave much better growth than those applied to the agar surface in water suspension in all media. Sodium citrate (0.2%) inhibited growth; pectin (0.2%) did also, but partial recovery occurred later. Best growth was on the basic medium seeded with uredospores in gelatin. The mycelium was white and fluffy in appearance at first, but collapsed later as a dense brown stroma developed beneath it. Diffusion of brown pigment into the agar medium took place with the gelatin, but not the water series. Sporulation was observed after 60 days in a few colonies and was located in the brown stroma. Spores were non-pigmented, oval in shape, and similar in size to typical uredospores. It is suggested that the physical environment around the spores affects growth.