Increased Acetylcholine Synthesis and Release in Brains of Cats with GM1 Gangliosidosis

Cholinergic processes were measured in motor cortex, hippocampus, and striatum of cats in the terminal stages of GM1 gangliosidosis and compared to those of control cats. The greatest difference observed was elevation in the rate of K+-stimulated release of acetylcholine (ACh) from brain slices prepared from affected cats. The K+-stimulated release of endogenous ACh was increased by 31-43% and of newly synthesized ACh by 19-80% in brain slices from different brain regions. All regions that were examined were affected but the greatest effects occurred in cortex. The rate of synthesis of ACh was elevated in cortical and hippocampal slices. Choline acetyltransferase activity in brain regions of cats with GM1 gangliosidosis was not significantly different from that in controls, whereas high-affinity choline transport in cortical synaptosomes was elevated. Muscarinic receptor binding sites were reduced in the cortex, hippocampus, and striatum of GM1 mutant cats, whereas the apparent affinity was not altered. These results indicate that there are major alterations of cholinergic function in the brains of cats with GM1 gangliosidosis.     

一种新病毒——兔出血症病毒的鉴定初报

从我国新发生的一种家兔急性败血性传染病死兔内脏抽提物中,观察到典型的病毒粒子,回归兔可引起典型发病,再从病死兔内脏回收到同样病毒,证明该病系病毒性传染病,暂定名为“兔病毒性出血症”,病原暂定为“兔出血症病毒”。经初步鉴定,认为本病毒可能是一种首次发现的新病毒,属双股RNA病毒。但从病毒大小和核酸节段看,又不同于呼肠病毒科。最终归属正在进一步研究。     

Release and establishment in Nigeria of Epidinocarsis lopezi, a parasitoid of the cassava mealybug, Phenacoccus manihoti

The encyrtid wasp Epidinocarsis (= Apoanagyrus) lopezi (De Santis) was imported from Paraguay into Nigeria for the biological control of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero. It was mass-reared and released at four localities in Nigeria. The parasitoid is now established and it is dispersing throughout cassava growing areas of Nigeria.

---

Libération et installation au Nigéria d'Epidinocarsis lopezi, parasitoïde de la cochenille du manioc Phenococcus manihoti

Résumé Epidinocarsis lopezi (Apoanagyrus) lopezi a été introduit du Paraguay au Nigéria pour lutter contre la cochenille du manioc, Phenacoccus manihoti. Il a été lâché dans quatre champs de manioc pour étudier son acclimatation et son installation au Nigéria. Trois ans après les lâchers, les résultats ont permis de conclure que E. lopezi s'est établi avec succès et se disperse dans la plupart des zones de culture du manioc au Nigeria; il a aussi survécu à trois saisons pluvieuses pendant lesquelles les populations de P. manihoti ont été très faibles. Quatorze mois après les premiers lâchers, cet encyrtide a été obtenu à environ 150 km du lieu de libération.

     

In vitro culture of the strobilar stage of Echinococcus granulosus from protoscoleces of human, camel, cattle, sheep and goat origin from Kenya and buffalo origin from India

Protoscoleces from human, camel, cattle, sheep, goat (all from Kenya) and buffalo (from India) hydatid cysts were cultured under identical conditions in vitro using the diphasic culture system of Smyth (1979b). Organisms from all sources grew and segmented in culture. Genital anlagen developed in all cultured worms but further genital differentiation occurred only in cultures of cattle (testes) and camel (testes and genital pore) material. The possible significance of these results is discussed in relation to the general epidemiology of hydatid disease and the potential infectivity of the different strains to man.     

Effects of ribavirin and adenine arabinoside on tobacco mosaic virus in Nicotiana tabacum L. var Xanthi tissue cultures

Although both ribavirin (1--ribofuranosyl-1,2,4-triazole-3carboxamide) and adenine arabinoside inhibited the multiplication of tobacco mosaic virus (TMV) in mechanically inoculated leaf tissues, neither chemical inhibited virus multiplication in unorganized tobacco callus after in vitro inoculation. The adenine deaminase inhibitor, pentostatin, did not increase the activity of adenine arabinoside in cultured cells. Several different developmental conditions and media did not increase the ability of either chemical to eradicate the virus from tobacco tissue cultures. However, the virus was eradicated from TMV-infected callus when grown in the presence of combinations of ribavirin and adenine arabinoside in shoot inducing medium.     

A microassay for detection of DNA and RNA in small numbers of plant cells

Summary A microtechnique for the detection of DNA or RNA in small numbers of plant cells (1–50) has been developed using cauliflower mosaic virus (CaMV) infection of turnip as a model system. Both DNA and RNA extracted from 10 mesophyll protoplasts from CaMV-infected plants can be detected by hybridization using a radioactive probe made from cloned CaMV DNA (pCaMV10). No hybridization above background was detected in extracts of protoplasts from uninfected plants. At least 0.15 pg (11 000 molecules) of purified pCaMV10 DNA can be detected. This method is superior to existing macro techniques for nucleic acid detection as smaller amounts of tissue are required and the detection is approximately 100-fold more sensitive. re]19850326 rv]19850530 ac]19850611     

Cellular systems for the study of the biosynthesis of polyamines and ethylene,as well as of virus multiplication

Leaves of Chinese cabbage from healthy plants or from those infected with turnip yellow mosaic virus yield protoplasts which convert methionine to protein, S-adenosylmethionine, decarboxylated S-adenosylmethionine, spermidine, spermine and 1-aminocyclopropane-1-carboxylate. The enzyme spermidine synthase is entirely cytosolic and has been purified extensively. An inhibitor of this enzyme, dicyclohexylamine, blocks spermidine synthesis in intact protoplasts, and in so doing stimulates spermine synthesis. Aminoethoxyvinylglycine blocks the conversion of S-adenosylmethionine to 1-aminocyclopropane-1-carboxylate, the precursor to ethylene, in protoplasts. This inhibitor markedly stimulates the synthesis of both spermidine and spermine. Essentially all the protoplasts obtained from new leaves of plants infected 7 days earlier are infected. On incubation, such protoplasts convert exogenous methionine to viral protein and viral spermidine whose specific radioactivity is twice that of total cell spermidine. Exogeneous spermidine is also converted to cell putrescine and viral spermidine and spermine. Normal and virus-infected cells are being studied for their content of phenolic acid amides of the polyamines.     

马立克氏病毒单克隆抗体的研究

获得了4株分泌马立克氏病毒(MDV)特异性单克隆抗体(McAb)的杂交瘤细胞:4BS10对MDV所有毒株呈阳性反应;4CN8 对MDV血清1,3型毒株发生反应;2BN90和4CN24只对MDV血清1型毒株有阳性反应。3个McAb属IgG1,1个为IgG2b,均不中和MDV,免疫扩散试验也无沉淀线。对禽白血病毒(ALV)无交叉反应。 以2BN90和辣根过氧化物酶、异硫氰酸荧光素的结合物进行直接酶联免疫吸附试验和直接荧光抗体试验,均获得成功。抗体滴度前者为1/51,200,后者为1/640。对ALV无交叉反应。     

Macrophage mediation of the inhibitory effects of elevated intracellular levels of adenosine-3':5' cyclic monophosphate (cAMP) on macrophage-Trypanosoma cruzi association

Presence of theophylline and dibutyryl-cAMP—agents which cause elevation of intracellular levels of cAMP—in in vitro systems in which murine macrophages interact with virulent blood forms of Trypanosoma cruzi resulted in a marked inhibition of cell-parasite association (i.e., decreased surface binding and/or internalization). This effect was evidenced in terms of significant reductions in both the percentage of infected macrophages and the average number of trypanosomes per 100 macrophages. Pretreatment of the macrophages with these agents produced a similar inhibition whereas pretreatment of the parasites had no significant consequence on the interaction. The inhibitory effect was transient since it was no longer seen after 30 min of incubation of the treated macrophages in fresh medium. Thus, the inhibitory effect is exerted through a transient effect on the macrophage.     

Structure of tomato bushy stunt virus: V. Coat protein sequence determination and its structural implications

We report the chemically determined sequence of most of the polypeptide chain of the coat protein of tomato bushy stunt virus. Peptide locations have been determined by comparison with the high-resolution electron density map from X-ray crystallographic analysis as well as by conventional chemical overlaps. Three small gaps remain in the 387-residue sequence. Positively charged side-chains are concentrated in the N-terminal part of the polypeptide (the R domain) as well as on inward-facing surfaces of the S domain. There is homology of S-domain sequences with structurally corresponding residues in southern bean mosaic virus.