Defensive secretions of larvae of a carabid beetle

Secretions of an eversible gland on the metathorax of larvae of Chlaenius cordicollis Kirby (Coleoptera: Carabidae) are investigated by headspace analysis using solid phase microextraction followed by gas chromatography‐mass spectrometry (GC‐MS). Larvae from Manitoba, Canada and Pennsylvania, U.S.A., are sampled. Nine presumed defensive compounds are detected when the gland is everted, and this represents the first characterization of defensive secretions of larvae of a carabid beetle. With the exception of a single component (2‐methoxy‐4‐methylphenol), these compounds are distinct from those found in the defensive secretion of adult C. cordicollis. However, seven are more oxidized versions of the alkylphenolic compounds secreted by adult beetles: three hydroquinones (hydroquinone, methylhydroquinone and 2,3‐dimethylhydroquinone) and four quinones (p‐benzoquinone, toluquinone, 2,3‐dimethylquinone and ethyl‐p‐benzoquinone). An additional alkoxyphenol (2‐methoxy‐4‐ethylphenol) is also detected. Two patterns of composition are observed: in one, p‐benzoquinone and hydroquinone are undetectable and the ratio of toluquinone : 2,3‐dimethylquinone is 1 : 4.6 ± 0.6 (mean ± SE); in the other, all nine compounds are detectable and the ratio of toluquinone : 2,3‐dimethylquinone is 1 : 1.0 ± 0.2. These differences in pattern do not appear to be related to geographical source, sex or age of the larvae.     

Down-regulation of phorbol diester binding to NG115-401L neuronal cells is dependent on structure, concentration and time

The down-regulation of [3H]PDBu binding to a neural cell line, NG115-401L, has been examined in response to two biologically active phorbol diesters, PDBu and PMA. Chronic treatment with PDBu or PMA causes a concentration- and time-dependent loss of specific [3H]PDBu binding. The action of PMA is biphasic with respect to both concentration and time dependence.     

Monoclonal antibodies which identify a genus-specific Listeria antigen.

Fifteen murine monoclonal antibodies (MAbs) which react specifically with a protein antigen found in all species of Listeria were developed and characterized. These MAbs were tested extensively by both enzyme-linked immunosorbent assay and Western blot (immunoblot) analyses for cross-reaction with non-Listeria organisms, such as Staphylococcus, Streptococcus, Citrobacter, Pseudomonas, and Salmonella species, and were found to be nonreactive. The genus-specific antigen was identified as a heat-stable protein with a molecular weight in the range of 30,000 to 38,000 (under both reducing and nonreducing conditions), depending on the species of Listeria tested. In Listeria monocytogenes, L. innocua, L. ivanovii, and L. seeligeri the antigen has a molecular weight of approximately 30,000 to 34,000. In L. grayi and L. murrayi it has a molecular weight of approximately 35,000 to 38,000. In addition, several of the MAbs recognize lower-molecular-weight protein bands. There appear to be at least two groups of Listeria-specific MAbs based upon isotype and results of enzyme-linked immunosorbent assay and Western blot analyses. These MAbs have proven to be useful in the development of a diagnostic assay for Listeria species in food products.     

Plasma 11-Hydroxycorticoid Levels after Carbenoxolone Sodium

A definite rise in plasma 11-hydroxycorticoid levels has been shown in eight patients with duodenal ulcer following the oral administration of carbenoxolone sodium. A similar rise was seen in one patient with sarcoidosis whose pituitary A.C.T.H. secretion had been acutely suppressed with dexamethasone. No such rise, however, was seen in three patients suffering from adrenal insufficiency. It is suggested that carbenoxolone acts directly on the adrenal cortex, causing an increased production of corticosteroids.     

Seed transmission of turnip yellow mosaic virus in winter turnip and winter oilseed rapes

This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings.     

Temperature sensitivity of fructose-1,6-biphosphate aldolase accounts for the inability of the high-virulence clone ofStreptococcus agalactiae to grow at 40°C

A high-virulence clone of serotype IIIStreptoccus agalactiae causing invasive neonatal disease has recently been identified by multilocus enzyme electrophoresis and can be further distinguished by its inability to grow at 40°C in a chemically defined medium. The basis for the unusual growth inhibition at 40°C was examined in the present study and shown to be owing to a temperature-sensitive fructose-1,6-bisphosphate aldolase (fba). Crude enzyme preparations (75% saturated ammonium sulfate precipitates) of fba obtained from a high-virulence clone demonstrated a 75% reduction in aldolase activity when preincubated at 40°C for 30 min compared with 37°C. In contrast, fba from a serotype III isolate obtained from an asymptomatically colonized infant demonstrated <10% decrease in activity at 40°C. Comparison of another enzyme, lactate dehydrogenase (ldh), from both organisms indicated no loss in activity at 40°C compared with 37°C. Glyceraldehyde-3-phosphate, one of the end-products of fba activity, relieved growth inhibition at 40°C.     

Aspects of hadrosaurian cranial anatomy

Supraorbital bones in Saurolophus angustirostris are described, and their presence in all hadrosaurs is suggested. Frontal-nasal and premaxillar-nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginous diverticulum nasi within the circumnarial depression in Saurobphus ongustirostris are presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is proposed.     

The influence of substrate organic content on the growth of a stream chironomid

Stream detritus and Tipula (Diptera) feces were wet-sieved to a 63–250 µm particle size range and mixed in three proportions with ashed sand of the same size to yield food substrates of varying quality. Growth of fourth-instar Stictochironomus annulicrus (Townes) (Diptera: Chironomidae) larvae was used to indicate whether the more nutritious particles were selected from these mixtures. Respective mean relative growth rates on the substrates, in order of decreasing percentage organic matter (i.e. food quality), were: 0.0229, 0.0104 and 0.0004 mg·mg^–1d^–1. Replicates of the relatively high quality substrate consistently elicited the highest growth rates; animals grew at intermediate rates on medium quality, and slowest on low quality substrates. Thus, this collector does not appear to have selected for food quality under the described experimental conditions.