Detrimental effects of latex and cardiac glycosides on survival and growth of first-instar monarch butterfly larvae Danaus plexippus feeding on the sandhill milkweed Asclepias humistrata

1. A novel experimental method was developed to study negative physical and chemical effects of latex and cardiac glycosides on first-instar monarch butterfly larvae in their natural environment in north central Florida. Forceps were used to nibble through the petioles of leaves of the sandhill milkweed Asclepias humistrata, mimicking the behaviour of mature monarch larvae. This notching cut off the supply-of latex to the leaves without significantly reducing either their cardiac glycoside concentration or water content. 2. The mean cardiac glycoside concentration in larvae that fed on intact leaves was nearly two: and a half times greater than in larvae that fed on notched leaves. This was probably because more latex is present in the gut of the larvae that fed on the intact leaves. Supporting this is the fact that the mean concentration of cardiac glycosides in the latex was 34-47 times that in the leaves. 3. Wet weights, dry weights, and growth rates of first-instar larvae that fed on intact leaves over a 72-h period were less than half those of larvae that fed on notched leaves. 4. Mortality due to miring in the latex was 27% on the intact leaves compared with 2% on the notched leaves. 5. Latex, cardiac glycosides, and other as yet undetermined plant factors all have a negative effect on:first-instar larval survival. 6. Video-analyses indicated that ingestion of latex caused the larvae to become cataleptic and increased their chances of being mired on the leaf by the setting latex glue. Dysfunction resulting from latex ingestion may lead to the larvae falling off the plant and being killed by invertebrate predators. 7. The difficulty of neonate monarch larvae surviving on A. humistrata - one of the principal milkweed species fed on each spring as monarchs remigrate from Mexico into the southern U.S.A. - is evidence that a co-evolutionary arms race is operating in this plant-herbivore system.

Back to (non)-Basics: Recent developments in neutral and charge-balanced glycosidase inhibitors

Certain glycosidase inhibitors possess potent antiviral, antitumour and antidiabetic properties. Glyconic acid lactones, the earliest glycosidase inhibitors identified, have planar anomeric carbons that mimic the transition state of glycoside hydrolysis. Other classes include lactams, glycals, epoxides, halides and sulfonium ions, the latter based on the natural product salacinol from an antidiabetic herb.

Two distinct arabinofuranosidases contribute to arabino-oligosaccharide degradation in Bacillus subtilis.

Microbiology 154 (2008) 2719-2729

Characterization of the abn2(yxiA) encoding a Bacillus subtilis GH43 arabinanase, Abn2, and its role in arabino-polysaccharides degradation.

Journal of Bacteriology (Junho 2008) 4272-4280

Overproduction, crystallization and preliminary X-ray characterization of Abn2, an endo-1,5-alpha-arabinanase from Bacillus subtilis.

Acta Crystallographica F64 (2008) 636-638

Modulation of inflammatory mediators by Opuntia ficus-indica and Prunus avium bioproducts using an in vitro cell-based model of intestinal inflammation

Dissertation to obtain a Master Degree in Biotechnology

Cutinase promotes dry esterification of cotton cellulose

Cutinase from Thermobifida fusca was used to esterify the hydroxyl groups of cellulose with the fatty acids from triolein. Cutinase and triolein were pre-adsorbed on cotton and the reaction proceeded in a dry state during 48 hours at 35ºC. The cutinase-catalyzed esterification of the surface of cotton fabric resulted in the linkage of the oleate groups to the glycoside units of cotton cellulose. The superficial modification was confirmed by performing ATR-FTIR on treated cotton samples and by MALDI-TOF analysis of the liquors from the treatment of the esterified cotton with a crude cellulase mixture. Modified cotton fabric also showed a significant increase of hydrophobicity. This work proposes a novel bio-based approach to obtain hydrophobic cotton. This article is protected by copyright. All rights reserved.

Natural bradykinin antagonists

Bradykinin (BK) a nonapeptide generated in plasma during tissue injury, is involved in many physiological and pathological states. Kinin actions are mediated by specific membrane receptors and involve a complex signal transducer and also second messager mechanisms. Due to its inequivocal relevance, an intensive effort has been focused in recent years to develop selective and competitive BK antagonists. Thus, the development of a new series of peptide BK antagonists has made an important contribution to the understanding of the pharmacological, physiological and pathophysiological role of BK, and this is certain to provide a firm basis for developing new drugs to relieve pain and inflammation. However, BK antagonists derived from peptide origin reported to date have limited clinical use due to their poor oral absortion and short duration of effect. Thus, considerable effort has also been made in developing stable nonpeptide BK antagonists. Up to now, most nonpeptide compounds reported to exhibit BK antagonistic activity have been derived from plants, including many flavonoids, terpenes, and also synthetic substances with various molecular structures. Amongst them, the pregnane glycoside compounds isolated from the plant Mandevilla velutina are the most promising. These compounds are effective in antognizing BK responses in a variety of preparations, and they also exhibit potent and long-lasting analgesic and anti-inflammatory activities. The exact mechanism underlying their action however, is not yet completely understood.

Bioactive glycosides from Chinese medicines

Glycosides are the bioactive components of many famous Chinese medicines. Here reported are some bioactive glycosides we discovered from Chinese medicines in recent years. (1) Pheolic glycosides from Chinese medicines: Gastrodia elata, acontium austroynanense and Helicia erratica, three bioactive phenolic glycosides were discovered and two of them have been developed into new drugs. (2) Terpenoidal glycosides: a) Monoterpenoid: the sweroside from Swertia mollensis has been developed intro an anti-hepatitis drug; b) Diterpenoid: Phlomis betonicoides contains sweet glycoides; c) Triterpenoid: many biologically active triterpenoid glycosides were isolated from Panax plants and Siraitia grosvenorii. (3) Steroidal glycosides: a) C21-steroid: Cynanchum otophyllum and C. atratrum contain anti-epilepsy and-tumor glycosides; b) C27-steroid Hemostatic saponins were found in Paris polyphylla.

Frequency of Fabry disease in male and female haemodialysis patients in Spain

BACKGROUND: Fabry disease (FD), an X-linked lysosomal storage disorder, is caused by a reduced activity of the lysosomal enzyme alpha-galactosidase A. The disorder ultimately leads to organ damage (including renal failure) in males and females. However, heterozygous females usually present a milder phenotype with a later onset and a slower progression. METHODS: A combined enzymatic and genetic strategy was used, measuring the activity of alpha-galactosidase A and genotyping the alpha-galactosidase A gene (GLA) in dried blood samples (DBS) of 911 patients undergoing haemodialysis in centers across Spain. RESULTS: GLA alterations were found in seven unrelated patients (4 males and 3 females). Two novel mutations (p.Gly346AlafsX347 and p.Val199GlyfsX203) were identified as well as a previously described mutation, R118C. The R118C mutation was present in 60% of unrelated patients with GLA causal mutations. The D313Y alteration, considered by some authors as a pseudo-deficiency allele, was also found in two out of seven patients. CONCLUSIONS: Excluding the controversial D313Y alteration, FD presents a frequency of one in 182 individuals (0.55%) within this population of males and females undergoing haemodialysis. Moreover, our findings suggest that a number of patients with unexplained and atypical symptoms of renal disease may have FD. Screening programmes for FD in populations of individuals presenting severe kidney dysfunction, cardiac alterations or cerebrovascular disease may lead to the diagnosis of FD in those patients, the study of their families and eventually the implementation of a specific therapy.

The effect of colostrum source (goat vs. sheep) and timing of the first colostrum feeding (2h vs. 14h after birth) on body weight and immune status of artificially reared newborn lambs.

Several factors can affect lamb body weight (BW) and immune status during the first days of life, including colostrum source and timing of the first colostrum feeding. The aim of this study was to evaluate the effects of colostrum source (goat or sheep) and timing of the first colostrum feeding (2 or 14h after birth) on lamb BW and immune status. In this study, 40 lambs were removed from their dams at birth and randomly assigned into 4 groups of 10 lambs each. Lambs were subsequently fed at 2 or 14h after birth with goat or sheep colostrum. Blood samples and BW recording were performed before feeding. Blood plasma was used to measure the immunoglobulin concentration (IgG and IgM), chitotriosidase activity, and complement system activity (total and alternative pathways). In general, no differences in any of the measured variables were observed among the 4 groups, indicating that neither colostrum source nor timing of the first colostrum feeding had an effect on these variables. These findings may improve management on lamb farms that raise animals under artificial conditions, because our results indicate that it is not necessary to feed colostrum to lambs immediately after birth and that goat colostrum may be used to feed newborn lambs.

Identification of serum and urine proteins responsible for enhanced pigment production by group B streptococci as amylases.

The serum and urine proteins responsible for enhanced pigment production in Streptococcus agalactiae in culture media were purified by chromatography and were identified as amylases by comparison of their amino acid composition with that calculated for proteins with known sequences. Similar pigment-enhancing activity was displayed by other amylases of nonanimal origin and by maltooligosaccharides.

Phytobezoar by aloe vera as long term complication after oesophagectomy resolved using cellulase.

Bezoars are uncommon diseases caused by the presence of indigestible mass of strange material in the gastrointestinal tract. Gold-standard treatment remains unclear and there are not clinical guidelines to follow. We present a very rare case of 53-year-old man suffering phytobezoar in a gastroplasty after oesophagectomy due to aloe vera ingestion as natural medicine. Finally it was solved with cellulase. Therefore, this is a scarcely complication after esophagectomy. Cellulase is a very good option to treat phytobezoar avoiding reintervention in this kind of patient.

Phytobezoar by aloe vera as long term complication after oesophagectomy resolved using cellulase.

Bezoars are uncommon diseases caused by the presence of indigestible mass of strange material in the gastrointestinal tract. Gold-standard treatment remains unclear and there are not clinical guidelines to follow. We present a very rare case of 53-year-old man suffering phytobezoar in a gastroplasty after oesophagectomy due to aloe vera ingestion as natural medicine. Finally it was solved with cellulase. Therefore, this is a scarcely complication after esophagectomy. Cellulase is a very good option to treat phytobezoar avoiding reintervention in this kind of patient.

Comparative functional analysis of two fibroblast growth factor receptor 1 (FGFR1) mutations affecting the same residue (R254W and R254Q) in isolated hypogonadotropic hypogonadism (IHH).

FGFR1 mutations have been identified in both Kallmann syndrome and normosmic HH (nIHH). To date, few mutations in the FGFR1 gene have been structurally or functionally characterized in vitro to identify molecular mechanisms that contribute to the disease pathogenesis. We attempted to define the in vitro functionality of two FGFR1 mutants (R254W and R254Q), resulting from two different amino acid substitutions of the same residue, and to correlate the in vitro findings to the patient phenotypes. Two unrelated GnRH deficient probands were found to harbor mutations in FGFR1 (R254W and R254Q). Mutant signaling activity and expression levels were evaluated in vitro and compared to a wild type (WT) receptor. Signaling activity was determined by a FGF2/FGFR1 dependent transcription reporter assay. Receptor total expression levels were assessed by Western blot and cell surface expression was measured by a radiolabeled antibody binding assay. The R254W maximal receptor signaling capacity was reduced by 45% (p<0.01) while R254Q activity was not different from WT. However, both mutants displayed diminished total protein expression levels (40 and 30% reduction relative to WT, respectively), while protein maturation was unaffected. Accordingly, cell surface expression levels of the mutant receptors were also significantly reduced (35% p<0.01 and 15% p<0.05, respectively). The p.R254W and p.R254Q are both loss-of-function mutations as demonstrated by their reduced overall and cell surface expression levels suggesting a deleterious effect on receptor folding and stability. It appears that a tryptophan substitution at R254 is more disruptive to receptor structure than the more conserved glutamine substitution. No clear correlation between the severity of in vitro loss-of-function and phenotypic presentation could be assigned.