Monolignol and dilignol glycosides from Pinus contorta leaves

Four monolignol glucosides have been isolated and identified from the needles of Pinus contorta. Chavicol 4-O-α-L-arabinofuranosyl-(1 →     

Acylated flavonol glucosides of Pinus contorta needles

From fresh Pinus contorta Doug (Coastal) needles four flavonol acylated glucosides and 6-methyl-kaempferol 3-β-D-glucoside were isolated. The three monoacylated glucosides were kaempferol-3-β-D(6-O-p- coumaryl)glucoside, isorhamnetin-3-β-D-(6-O-acetyl)glucoside, quercetin-3-β-D-(p-coumaryl)glucoside and the diacyl compound was kaempferol-3-β-D-(di-p-coumaryl)glucoside.     

Implications of life-history strategies for a new wrasse fishery

The variety of life-history patterns exhibited by the five species of wrasse common in Northern Europe are reviewed. The two larger wrasse species, the ballan, Labrus bergylta Ascanius, and cuckoo, Labrus mixtus (L.), are exploited through sport angling. The three smaller species, the corkwing, Symphodus (Crenilabrus) melops (L.), rock cook, Centrolabrus exoletus (L.) and goldsinny, Ctenolabrus rupestris (L.), are being exploited by a new fishery for use as parasite cleaners of farmed salmon.
The nature of salmon farming limits the wrasse fishery to a minimum size, restricted areas and the warmer months of the year. The fishery may be expected to alter population structure through selective removal of larger fish. Removal of dominant territorial males may affect social structures and removal of nest-guarding males would reduce egg survival. Quantitative models incorporating stock size and fishery requirements are now required.     

Mechanism of activation of cyclic GMP-dependent protein kinase from rat liver by multiple modulators

A number of polyanionic compounds, including DNA, RNA and polyglutamate, were shown to exhibit protein kinase stimulatory modulator activity as they were required for cyclic GMP to stimulate the phosphorylation of various cationic substrates by rat liver cyclic GMP-dependent protien kinase. Anionic proteins (casein, phosvitin) were phosphorylated poorly by the enzyme and their phosphorylation was not stimulated by the stimulatory modulators. Studies of the mechanism of action suggest that the modulators interact directly with the substrates to form a complex which is a better substrate than free histone. The observed effect of modulator is complex as it depends on the ratio of modulator to histone and the resultant state of the complex formed (better or poorer substrate than free histone). The observed effect is also dependent on the properties of the histone substrate as Michaelis-Menten kinetics are not observed in the phosphorylation of arginine-rich histone in the absence or presence of cyclic GMP.     

Spondyloepiphyseal dysplasia, chondroitin sulfate type: a possible defect of PAPS--chondroitin sulfate sulfotransferase in humans

Four patients with an unusual form of spondyloepiphyseal dysplasia excreted in the urine undersulfated chondroitin 6-sulfate (Biochem. Med. $\text{7}$, 415–423, 1973). The sera of these patients show a low activity of PAPS — chondroitin sulfate sulfotransferase, while the undersulfated chondroitin sulfate present in their urine is a much better acceptor of ${}^{35}\text{SO}{}_4$ than standard chondroitin sulfate when they are incubated with [${}^{35}\text{S}$]PAPS and normal sulfotransferases. These results suggest that in these patients the skeletal lesions are secondary to a defect in the synthesis of chondroitin sulfate involving specifically the sulfotransferase activity.     

Antigen-binding cells in central and peripheral lymphoid tissues of the rabbit

The rosette assay was used to study antigen-binding activity by cells in lymphoid tissues of rabbits immunized with sheep red blood cells and in unimmunized controls. Percentages of rosette-forming cells (RFC) observed were compared with those of cells which secreted antibody (plaque-forming cells, PFC) and cells which both bound antigen and secreted antibody. Rosette-forming cells and PFC were shown to be two distinct reactive cell populations. Thus, in the spleen less than 1% of RFC also formed plaques. Immediately following antigen stimulation, the number of RFC in the bone marrow decreased to below detectable limits. After an initial rise, the number of RFC in the appendix declined similarly. In contrast, RFC levels in the spleen rose steadily from the time of immunization. These patterns suggest that bone marrow and appendix may function as a reservoir of antigen-binding cells which are released to other sites following antigenic stimulation. Rosette-forming cells were rarely observed in the thymus. Rosette-inhibition studies using antisera specific for bone marrow-derived cells (anti-B) and thymus-derived cells (anti-T) revealed a markedly greater proportion of T-RFC in the appendix than in the spleen.     

Nucleic Acid Tools for Invasive Fungal Disease Diagnosis

Current Fungal Infection Reports - This review has incorporated the knowledge and experience of the leads of each of the laboratory working parties of the fungal PCR initiative in order to provide...     

Thermal adaptations to extreme freeze–thaw cycles in the high tropical Andes

Temperature plays a key role in the biology of ectotherms, including anurans, which are found at higher elevations in the tropics than anywhere in the temperate zone. High elevation tropical environments are characterized by extreme daily thermal fluctuation including high daily maxima and nightly freezing. Our study investigated the contrasting operative temperatures of the anurans Telmatobius marmoratus and Pleurodema marmoratum in different environmental contexts at the same elevation and biome above 5,200 m. Telmatobius marmoratus avoids extremes of daily temperature fluctuation by utilizing thermally buffered aquatic habitat at all life stages, with minimal operative temperature variation (range: 4.6–8.0°C). Pleurodema marmoratum, in contrast, experienced operative temperatures from ?3.5 to 44°C and has one of the widest thermal breadths reported for any tropical frog, from >32°C (critical thermal maximum) to surviving freezing periods of 1 and 6 hr down to ?3.0°C. Our findings expand experimental evidence of frost tolerance in amphibians to the widespread Neotropical family Leptodactylidae, the first such evidence of frost tolerance in a tropical amphibian. Our study identifies three strategies (wide thermal tolerance breadth, use of buffered microhabitats, and behavioral thermoregulation), which allow these tropical frogs to withstand the current wide daily thermal fluctuation above 5,000 m.a.s.l. and which may help them adapt to future climatic changes. Abstract in Spanish is available with online material     

Aerosol Exposure to Rift Valley Fever Virus Causes Earlier and More Severe Neuropathology in the Murine Model,which Has Important Implications for Therapeutic Development

Rift Valley fever virus (RVFV) is an important mosquito-borne veterinary and human pathogen that can cause severe disease including acute-onset hepatitis, delayed-onset encephalitis, retinitis and blindness, or a hemorrhagic syndrome. Currently, no licensed vaccine or therapeutics exist to treat this potentially deadly disease. Detailed studies describing the pathogenesis of RVFV following aerosol exposure have not been completed and candidate therapeutics have not been evaluated following an aerosol exposure. These studies are important because while mosquito transmission is the primary means for human infection, it can also be transmitted by aerosol or through mucosal contact. Therefore, we directly compared the pathogenesis of RVFV following aerosol exposure to a subcutaneous (SC) exposure in the murine model by analyzing survival, clinical observations, blood chemistry, hematology, immunohistochemistry, and virus titration of tissues. Additionally, we evaluated the effectiveness of the nucleoside analog ribavirin administered prophylactically to treat mice exposed by aerosol and SC. The route of exposure did not significantly affect the survival, chemistry or hematology results of the mice. Acute hepatitis occurred despite the route of exposure. However, the development of neuropathology occurred much earlier and was more severe in mice exposed by aerosol compared to SC exposed mice. Mice treated with ribavirin and exposed SC were partially protected, whereas treated mice exposed by aerosol were not protected. Early and aggressive viral invasion of brain tissues following aerosol exposure likely played an important role in ribavirin''s failure to prevent mortality among these animals. Our results highlight the need for more candidate antivirals to treat RVFV infection, especially in the case of a potential aerosol exposure. Additionally, our study provides an account of the key pathogenetic differences in RVF disease following two potential exposure routes and provides important insights into the development and evaluation of potential vaccines and therapeutics to treat RVFV infection.