In vitro and in vivo activity of ribavirin against Andes virus infection

Pathogenic hantaviruses are a closely related group of rodent-borne viruses which are responsible for two distinct diseases in humans, hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome (HPS, otherwise known as hantavirus cardiopulmonary syndrome, HCPS). The antiviral effect of ribavirin against Old World hantaviruses, most notably Hantaan virus, is well documented; however, only a few studies have addressed its inhibitory effect on New World hantaviruses. In the present study, we demonstrate that ribavirin is highly active against Andes virus (ANDV), an important etiological agent of HPS, both in vitro and in vivo using a lethal hamster model of HPS. Treatment of ANDV infected Vero E6 cells with ribavirin resulted in dose-dependent reductions in viral RNA and protein as well as virus yields with a half maximal inhibitory concentration between 5 and 12.5 μg ml(-1). In hamsters, treatment with as little as 5 mg kg(-1) day(-1) was 100% effective at preventing lethal HPS disease when therapy was administered by intraperitoneal injection from day 1 through day 10 post-infection. Significant reductions were observed in ANDV RNA and antigen positive cells in lung and liver tissues. Ribavirin remained completely protective when administered by intraperitoneal injections up to three days post-infection. In addition, we show that daily oral ribavirin therapy initiated 1 day post-infection and continuing for ten days is also protective against lethal ANDV disease, even at doses of 5 mg kg(-1) day(-1). Our results suggest ribavirin treatment is beneficial for postexposure prophylaxis against HPS-causing hantaviruses and should be considered in scenarios where exposure to the virus is probable. The similarities between the results obtained in this study and those from previous clinical evaluations of ribavirin against HPS, further validate the hamster model of lethal HPS and demonstrate its usefulness in screening antiviral agents against this disease.     

Synthesis of phosphatidylglycerol by chloroplasts from leaves of Spinacia oleracea L. (spinach)

Purified chloroplasts from leaves of Spinacia oleracea L. (spinach) incorporated glycerol 3-phosphate into diacylglycerol, monoacylglycerol, phosphatidylglycerol, phosphatidic acid, and lysophosphatidic acid. The omission of ATP or CTP, CoA or illumination decreased the incorporation markedly. The fraction of incorporated glycerol 3-phosphate found in phosphatidylglycerol was greatly reduced by the omission of bicarbonate, acetate, and ATP, or in darkness, low-osmolarity medium, or high magnesium ion concentration (10 mM). Incorporation of glycerol 3-phosphate into lipid and specifically into phosphatidylglycerol was optimal at a $\text{Mg}{}^{\mathrm{2+}}\text{CTP}$ ratio of 1, whereas the optimal ratio for $\text{Mg}{}^{\mathrm{2+}}\text{ATP}$ was closer to 2. The $\text{Mg}{}^{\mathrm{2+}}\text{CTP}$ gave lower total incorporation but a higher fraction of incorporation in phosphatidylglycerol. Triton X-100 inhibited incorporation of glycerol 3-phosphate into lipid, especially into phosphatidylglycerol.     

The combination of photogrammetry and finite elements for a fine grained functional analysis of anatomical structures

Summary A new method of functional morphological analysis is presented. Combining stereophotogrammetry with the finite element technique, a new approach, permits a three-dimensional numerical stress analysis of arbitrarily shaped bodies to be performed. The stereophotogrammetric method which originated for three-dimensional calculations in the study of surfaces in land surveying is well suited for the determination of the nodal co-ordinates required for the finite element method, an engineering technique developed for behavioural analysis of solids and fluids responding to external forces. This approach was tested in a study of the functional morphology of the bill of an African wading bird, the shoebill Balaeniceps rex. A few findings of that study are given here in order to demonstrate the method. Advantages of the finite element method compared with other techniques for stress analysis of anatomical structures are also discussed. The method presents exciting possibilities for predicting displacement and stress responses more accurately and in much greater detail. The scope of this powerful computerized stress analysis technique is greatly enhanced with the introduction of stereophotogrammetry for determining the three-dimensional co-ordinates of complex anatomical structures. With the finite element method, the properties of the bone structure can be modelled as they occur in the life of the animal. This is not possible with physical models. Furthermore, rare specimens can be analysed non-destructively.     

Binding of simple carbohydrates and some N-acetyllactosamine-containing oligosaccharides to Erythrina cristagalli agglutinin as followed with a fluorescent indicator ligand

Erythrina cristagalli agglutinin, a dimeric lectin [J. L. Iglesias, et al. (1982) Eur. J. Biochem.123, 247–252] was shown by equilibrium dialysis to be bivalent for 4-methylumbelliferyl-β-d-galactoside. Upon binding to the lectin, this ligand showed a difference absorption spectrum with two maxima (at 322 and 336 nm) of equal intensity (Δ? = 1.2 × 10³m^?1 cm^?1). A similar spectrum with a comparable value of Δ? was obtained with 4-methylumbelliferyl-N-acetyl-β-d-galactosaminide. Binding of methyl-α-d-galactoside, lactose, and N-acetyllactosamine all produced small but equally intense protein difference spectra with a maximum (Δ? = 2.8 × 10² M^?1 cm^?1) at 291.6 nm. Upon binding of N-dansyl-d-galactosamine to the lectin, there was a fivefold increase in fluorescence intensity of this ligand. The association constant for N-dansyl-d-galactosamine was caused by a very favorable ΔS° of the dansyl group without affecting the strictly carbohydrate-specific character of binding. N-Dansyl-d-galactosamine was employed as a fluorescent indicator ligand in substitution titrations. This involved the use of simple carbohydrates, N-acetyllactosamine, and oligosaccharides which occur in the carbohydrate units of N-glycoproteins; the latter were Gal(β → 4)GlcNAc(β1 → 2)Man, Gal(β1 → 4)GlcNAc(β1 → 6)Man, and Gal(β1 → 4)GlcNAc(β1 → 6)[Gal(β1 → 4)GlcNAc(β1 → 2)]Man. The titrations were performed at two temperatures to determine the thermodynamic parameters. In the series N-acetyl-d-galactosamine, methyl-α-d-galactoside, and lactose, ?ΔH° increased from 24 to 41 kJ mol^?1; it increased further for N-acetyllactosamine and then remained unchanged for the N-acetyllactosamine-containing oligosaccharides (55 ± 1 kJ mol^?1). This indicated that the site specifically accommodated the disaccharide structure with an important contribution of the 2-acetamido group in the penultimate sugar. Beyond this, no additional contacts seemed to be formed. This conclusion also followed from considerations of ΔS° values which became more unfavorable in the above series (?23 to ?101 ± 4 J mol^?1 K^?1); the most negative value of ΔS° was observed with N-acetyllactosamine and the three N-acetyllactosamine-containing oligosaccharides.     

Bile acids and their nuclear receptor FXR: Relevance for hepatobiliary and gastrointestinal disease

The nuclear receptor Farnesoid X Receptor (FXR) critically regulates nascent bile formation and bile acid enterohepatic circulation. Bile acids and FXR play a pivotal role in regulating hepatic inflammation and regeneration as well as in regulating extent of inflammatory responses, barrier function and prevention of bacterial translocation in the intestinal tract. Recent evidence suggests, that the bile acid–FXR interaction is involved in the pathophysiology of a wide range of diseases of the liver, biliary and gastrointestinal tract, such as cholestatic and inflammatory liver diseases and hepatocellular carcinoma, inflammatory bowel disease and inflammation-associated cancer of the colon and esophagus. In this review we discuss current knowledge of the role the bile acid–FXR interaction has in (patho)physiology of the liver, biliary and gastrointestinal tract, and proposed underlying mechanisms, based on in vitro data and experimental animal models. Given the availability of highly potent synthetic FXR agonists, we focus particularly on potential relevance for human disease.     

The rhodium(III) trisacetonitrile complexes: a re-investigation of the synthesis of fac- and mer- [RhCl3(CH3CN)3], their characterization by 2D NMR spectroscopy and the X-ray crystal structure of mer-[RhCl3(CH3CN)3] · CH3CN

It is shown that the reaction of RhCl₃·3H₂O with acetonitrile normally produces mixtures of mer- and fac-[RhCl₃(CH₃CN)₃] (1a and 1b, respectively). The IR and ¹H NMR spectra of these isomers were re-investigated. Their two-dimensional (¹⁰³Rh,¹H) NMR spectra were also recorded. Equilibrium and exchange studies of 1a and 1b in CD₃C were performed. It was found that in 1a the exchange rate of the nitrile molecule trans to Cl is much faster than those of mutually trans nitriles. Also the nitrile molecules in 1b underwent fast exchange in CD₃CN; however, their rate was slightly faster than that of the more labile CH₃CN in 1a. The X-ray crystal structure of mer-[RhCl₃(CH₃CN)₃]·CH₃CN (1c) was determined. Crystal data: triclinic space group

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A novel family of linear plasmids with homology to plasmid pAL2-1 of Podospora anserina

Three recently isolated wild-type strains of the ascomycete Podospora anserina were analyzed for the presence of linear mitochondrial plasmids. In one of these strains, designated Wa6, at least 12 distinct plasmid-like elements were identified. From molecular analyses a minimum number of 78 individual linear molecules with proteins bound to their 5′ ends was estimated. In addition, the different members of this family of typical linear plasmids were shown to possess a common central region and terminal sequences which differ from one plasmid to another due to the presence of different numbers of a 2.4 kb sequence module. Finally, the pWa6 plasmids share a high degree of sequence similarity with pAL2-1, a linear plasmid previously identified in mitochondria of a long-lived mutant of P.anserina. A mechanism is proposed which explains the generation of these distinct, closely related extrachromosomal genetic traits.     

Different responses of tobacco antioxidant enzymes to light and chilling stress

The effect of elevated light treatment (25 degrees C, PPFD 360 mumol m-2 sec-1) or chilling temperatures combined with elevated light (5 degrees C, PPFD 360 mumol m-2 sec-1) on the activity of six antioxidant enzymes, guaiacol peroxidases, and glutathione peroxidase (GPx, EC 1.11.1.9) protein accumulation were studied in tobacco Nicotiana tabacum cv. Petit Havana SR1. Both treatments caused no photooxidative damage, but chilling caused a transient wilting. The light treatment increased the activities of ascorbate peroxidase (APx, EC 1.11.1.11) and guaiacol peroxidases while catalase (EC 1.11.1.6), superoxide dismutase (SOD, EC 1.15.1.1), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (EC 1.6.4.2) were unchanged. In contrast, chilling treatment did not increase any of the antioxidant enzyme activities, but decreased catalase and to a lesser extent DHAR activities. Glutathione peroxidase protein levels increased sporadically under light treatment and constantly under chilling. Both chilling and light stress caused induction of glutathione synthesis and accumulation of oxidised glutathione, although the predominant part of the glutathione pool remained in the reduced form. Antioxidant enzymes from the chilling treated plants were measured at both 25 degrees C and 5 degrees C. Measurements at 5 degrees C revealed a 3-fold reduction in catalase activity, compared with that measured at 25 degrees C, indicating that the overall reduction in catalase after four days of chilling was approximately 10-fold. The overall reduction in activity for the other antioxidant enzymes after four days of chilling was 2-fold for GR and APx, 1.5-fold for MDHAR, 3.5-fold for DHAR. The activity of SOD was the same at 25 and 5 degrees C. These results indicate that catalase and DHAR are most strongly affected by the chilling treatment and may be the rate-limiting factor of the antioxidant system at low temperatures.     

Goldston syndrome: report of a case.

Cerebrohepatorenal malformation is a rare familial disorder characterized by typical renal lesions combined with Dandy-Walker malformation, and congenital hepatic fibrosis. In this case report, a male premie with the diagnosis of cerebrorenal syndrome or so called Goldston syndrome is presented. Besides the rarity of this syndrome, this case is the second reported patient diagnosed prenatally.     

Caste-specific modulation of juvenile hormone III content and ecdysteroid titer in postembryonic development of the stingless bee,Scaptotrigona postica depilis

Summary Juvenile hormone III content and ecdysteroid titer were analyzed for larval and pupal development of the stingless bee,Scaptotrigona postica depilis. Castespecific differences in juvenile hormone III content were detected at three developmental phases: at the transition from the fourth to the fifth larval stadium, in the spinning phase of the fifth larval stadium, and shortly after the imaginal moult. During the fifth larval stadium, juvenile hormone content closely reflects corpora allata activity. Juvenile hormone synthesis may thus be responsible for the elevated hormone titer in spinning-phase queen larvae, a phase of known sensitivity for induction of queen characters by exogenous juvenile hormone. For ecdysteroids, two phases of caste-specific differences were found: in the pre-pupal phase, and shortly after the imaginal moult. In both periods the titer in queens is distinctly higher compared to workers.Abbreviations Im imago 1 day after eclosion - L3, L4, L5 larval instars 3, 4, and 5 - L5F1, L5F2 substages of feeding phase in fifth larval instar - L5S1, L5S2, L5S3 substages of spinning phase in fifth larval instar - PP1, PP2 substages of prepupal phase - Pw white eyed pupa - Pp pink eyed pupa - Pr red eyed pupa - Pd dark eyed pupa - Pdl, Pdm, Pdd dark eyed pupa with progressive tanning of cuticle - RIA radioimmunoassay