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941.
The mushroom Lepiota josserandii Bon and Boif. has been identified as the cause of an unintentional, fatal intoxication in New York. The course of the symptoms, beginning with a 9 h latent period, was similar to what would be expected in a case of Amanita phalloides-type intoxication. Despite supportive medical care the victim expired 110 h after ingestion. Thin layer chromatography detected the presence of alpha- and gamma-amanitin and radioimmunoassay confirmed a level of 3.5 mg/gm dry weight of amatoxins in mushrooms from the same location.Published as New York State Museum Journal Series No. 440. 相似文献
942.
Stanley W. Watson Eberhard Bock Frederica W. Valois John B. Waterbury Ursula Schlosser 《Archives of microbiology》1986,144(1):1-7
A new chemolithotrophic nitrite-oxidizing bacterium, for which the name Nitrospira marina is proposed, was isolated from the Gulf of Maine. N. marina is a Gramnegative curved rod which may form spirals with 1 to 12 turns. Cells have a unique periplasmic space and lack intracytoplasmic membranes and carboxysomes. N. marina is an obligate chemolithotroph, but best growth is obtained in a mixotrophic medium. N. marina may be one of the most prevalent nitrite-oxidizing bacteria in some oceanic environments. Type strain is field with American Type Culture Collection (ATCC 43039). 相似文献
943.
A dynamic programming algorithm for finding alternative RNA secondary structures. 总被引:14,自引:8,他引:6 下载免费PDF全文
Dynamic programming algorithms that predict RNA secondary structure by minimizing the free energy have had one important limitation. They were able to predict only one optimal structure. Given the uncertainties of the thermodynamic data and the effects of proteins and other environmental factors on structure, the optimal structure predicted by these methods may not have biological significance. We present a dynamic programming algorithm that can determine optimal and suboptimal secondary structures for an RNA. The power and utility of the method is demonstrated in the folding of the intervening sequence of the rRNA of Tetrahymena. By first identifying the major secondary structures corresponding to the lowest free energy minima, a secondary structure of possible biological significance is derived. 相似文献
944.
Summary Mice immunized by excision of a primary, subcutaneously growing SV40-induced mKSA solid tumor which resisted challenge of homologous tumor cells administered at a contralateral site, were found to develop a specific DTH response to SV40 tumor associated transplantation antigens (TATA).In a two-way criss-cross experiment, this DTH response (assessed by direct challenge) was found to be one-way SV40 specific in that chemically induced, non SV40, MCA tumor failed to elicit a DTH response in mice primed by excision of mKSA tumor.These mice also showed a corresponding one-way specific protection against challenge with live homologous mKSA sarcoma cells. In contrast immunization and challenge of MCA-excised mice with either MCA or mKSA tumor cells, exhibited cross-reactivity in both DTH response and protection against either tumor.Unlike this cross-immunity by the direct challenge method, transfer of immune spleen cells from mKSA or MCA excision-primed mice demonstrated a specific DTH response and protection to the original immunizing, homologous but not heterologous tumor. Tumor resistant, DTH-primed mice remained DTH reactive to the primary tumor cells over a period of 4 weeks. Characterization of the splenic T-DTH cells in mice primed by excision of mKSA tumor, indicated a Lyt 1+2+ phenotype of cells conferring both the DTH response and the immune protection against mKSA sarcoma in a local (Winn) adoptive transfer assay, thus reinforcing the correlation between the DTH response and the antitumor protection. 相似文献
945.
Scott L. Hooper Michael B. O'Neil Robert Wagner John Ewer Jorge Golowasch Eve Marder 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1986,159(2):227-240
Summary The muscles of the pyloric region of the stomach of the crab,Cancer borealis, are innervated by motorneurons found in the stomatogastric ganglion (STG). Electrophysiological recording and stimulating techniques were used to study the detailed pattern of innervation of the pyloric region muscles. Although there are two Pyloric Dilator (PD) motorneurons in lobsters, previous work reported four PD motorneurons in the crab STG (Dando et al. 1974; Hermann 1979a, b). We now find that only two of the crab PD neurons innervate muscles homologous to those innervated by the PD neurons in the lobster,Panulirus interrruptus. The remaining two PD neurons innervate muscles that are innervated by pyloric (PY) neurons inP. interruptus. The innervation patterns of the Lateral Pyloric (LP), Ventricular Dilator (VD), Inferior Cardiac (IC), and PY neurons were also determined and compared with those previously reported in lobsters. Responses of the muscles of the pyloric region to the neurotransmitters, acetylcholine (ACh) and glutamate, were determined by application of exogenous cholinergic agonists and glutamate. The effect of the cholinergic antagonist, curare, on the amplitude of the excitatory junctional potentials (EJPs) evoked by stimulation of the pyloric motor nerves was measured. These experiments suggest that the differences in innervation pattern of the pyloric muscles seen in crab and lobsters are also associated with a change in the neurotransmitter active on these muscles. Possible implications of these findings for phylogenetic relations of decapod crustaceans and for the evolution of neural circuits are discussed.Abbreviations
ACh
acetylcholine
-
Carb
carbamylcholine
-
cpv
muscles of the cardio-pyloric valve
-
cpv7n
nerve innervating muscle cpv7
-
cv
muscles of the ventral cardiac ossicles
-
cv1n
nerve innervating muscle cvl
-
cv2n
nerve innervating muscle cv2
-
EJP
excitatory junctional potential
-
IC
inferior cardiac neuron
-
IV
inferior ventricular neuron
-
IVN
inferior ventricular nerve
-
LP
lateral pyloric neuron
-
LPG
lateral posterior gastric neuron
-
lvn
lateral ventricular nerve
-
mvn
medial ventricular nerve
-
p
muscles of the pylorus
-
PD
pyloric dilator neuron
-
PD
in
intrinsic PD neuron
-
PD
ex
extrinsic PD neuron
-
pdn
pyloric dilator nerve
-
PY
pyloric neuron
-
pyn
pyloric nerve
-
STG
stomatogastric ganglion
-
VD
ventricular dilator neuron 相似文献
946.
Plasmid pULB113 (RP4::Mini-Mu) promoted homologous gene transfer inAeromonas hydrophila; transfer of chromosomal markers occurred at frequencies of between 10–3 and 10–4 per donor cell regardless of the marker selected; this indicated chromosome transfer from multiple origins. With a variety of amino acid biosynthetic markers, a single circular map of this bacterium was constructed. 相似文献
947.
John D. Smith 《Environmental Biology of Fishes》1986,16(4):295-308
Synopsis The seasonal transmission ofRaphidascaris acus was studied in two small lakes on Manitoulin Island, Ontario. Dragonfly nymphs and caddisfly larvae, acting as paratenic hosts, contained second-stage larvae. Several fishes, including percids and cyprinids, were intermediate hosts with second, third, and fourth-stage larvae in the liver. Yellow perch,Perca flavescens, was the most important of these. Intensities were up to 928 and increased with length and age of the perch; prevalence was 100%. Abundance ofR. acus tended to be higher in females but was not related to condition of the perch. Second-stage larvae were acquired from invertebrates in summer and developed to the fourth stage by November. They became surrounded by fibrous capsules during the next summer but remained alive for at least another year. The longevity of larvae in the intermediate host may ensure survival of the parasite through periods of low host abundance after winterkill. Northern pike,Esox lucius, was the definitive host. Abundance ofR. acus tended to be greater in larger pike but was not related to sex or condition of the fish. The parasite was acquired in late fall. Prevalence was 100% and mean intensities were over 200 in winter and spring, declining to 64–100% and less than 15, respectively, in summer. Mature worms were present from early spring through summer. Seasonality of infection in the definitive host is not attributable to seasonal availability of larvae in perch. Instead it may be controlled by timing of predation on perch and rate of development and longevity of the parasite. Transmission to pike apparently continues in summer. Low intensity may result from low recruitment rate and rapid turnover of the parasite population. 相似文献
948.
Eight flavonoids, four 6-oxygenated flavones, two methyl ethers of luteolin, apigenin 6,8-C-diglucoside and quercetin 3-O-glucoside,
were isolated fromNama lobbii andN. rothrockii, sole members of sects.Arachnoidea andCinerascentia, respectively. Both taxa diverge markedly from other namas in morphology and chromosome number and their placement inNama has been questioned. The occurrence of 6-oxygenated flavones in these taxa adds to their already distinctive nature. Flavonoid
evidence argues that both are more closely allied toEriodictyon than either is toNama. 相似文献
949.
Direct somatic embryogenesis on immature zygotic embryos in vitro has been confirmed for Trifolium pratense and extended to T. resupinatum and T. subterraneum. For all species direct embryo cloning can be achieved on an appropriate basal medium supplemented with 1gl–1 yeast extract and 0.05 mgl–1 BAP. Basal medium/sucrose formulation, level of yeast extract and level of BAP affected the nature of in vitro responses. In particular, for T. pratense and T. subterraneum lowering of the yeast extract level suppressed embryoid initiation, and raising of the BAP level stimulated formation of nodular morphogenic callus. For T. resupinatum alteration of the basal medium/sucrose formulation changed the tissue site of embryoid initiation from hypocotyl to cotyledons or both. Control of embryoid initiation is briefly discussed.Abbreviation BAP
6-benzylaminopurine 相似文献
950.
Keisuke Kohmoto Kazuya Akimitsu Tetsuyuki Kohguchi Hiroshi Otani John M. Gardner 《Plant cell reports》1986,5(1):54-56
Amberlite XAD-7, a nonionic polyacrylate adsorbent, was found to be a very effective protectant for isolating mitochondria from tissues rich in oils and phenolics. Physiologically active, well-coupled mitochondria were successfully prepared from young green leaf tissues of citrus, apple, pear and tobacco.Abbreviations DNP
2,4-dinitrophenol
- CCCP
carbonyl cyanide m-chlorophenylhydrazone
- BSA
bovine serum albumin
- PVP
polyvinylpyrrolidone 相似文献