Spatial pattern of black spot incidence within citrus trees related to disease severity and pathogen dispersal

Guignardia citricarpa, the causal agent of citrus black spot, forms airborne ascospores on decomposing citrus leaves and water-spread conidia on fruits, leaves and twigs. The spatial pattern of diseased fruit in citrus tree canopies was used to assess the importance of ascospores and conidia in citrus black spot epidemics in Sao Paulo State, Brazil. The aggregation of diseased fruit in the citrus tree canopy was quantified by the binomial dispersion index (D) and the binary form of Taylor`s Power Law for 303 trees in six groves. D was significantly greater than 1 in 251 trees. The intercept of the regression line of Taylor`s Power Law was significantly greater than 0 and the slope was not different from 1, implying that diseased fruit was aggregated in the canopy independent of disease incidence. Disease incidence (p) and severity (S) were assessed in 2875 citrus trees. The incidence-severity relationship was described (R-2 = 88.7%) by the model ln(S) = ln(a) + bCLL(p) where CLL = complementary log-log transformation. The high severity at low incidence observed in many cases is also indicative of low distance spread of G. citricarpa spores. For the same level of disease incidence, some trees had most of the diseased fruit with many lesions and high disease severity, whereas other trees had most of the fruit with few lesions and low disease severity. Aggregation of diseased fruit in the trees suggests that splash-dispersed conidia have an important role in increasing the disease in citrus trees in Brazil.

Localization of Pantoea ananatis inside lesions of maize White Spot Disease using transmission electron microscopy and molecular techniques

The etiological agent of maize white spot (MWS) disease has been a subject of controversy and discussion. Initially the disease was described as Phaeosphaeria leaf spot caused by Phaeosphaeria maydis. Other authors have Suggested the existence of different fungal species causing similar symptoms. Recently, a bacterium, Pantoea ananatis, was described as the causal agent of this disease. The purpose of this Study was to offer additional information on the correct etiology of this disease by providing visual evidence of the presence of the bacterium in the interior of the MWS lesions by using transmission electron microscopy (TEM) and molecular techniques. The TEM allowed Visualization of a large amount of bacteria in the intercellular spaces of lesions collected from both artificially and naturally infected plants. Fungal structures were not visualized in young lesions. Bacterial primers for the 16S rRNA and rpoB genes were used in PCR reactions to amplify DNA extracted from water-soaked (young) and necrotic lesions. The universal fungal oligonucleotide ITS4 was also included to identity the possible presence of fungal structures inside lesions. Positive PCR products from water-soaked lesions, both from naturally and artificially inoculated plants, were produced with bacterial primers, whereas no amplification was observed when ITS4 oligonucleotide was used. On the other hand, DNA amplification with ITS4 primer was observed when DNA was isolated from necrotic (old) lesions. These results reinforced previous report of P. ananatis as the primary pathogen and the hypothesis that fungal species may colonize lesions pre-established by P. ananatis.

Development of Ramulosis Disease of Cotton Under Controlled Environment and Field Conditions

Colletotrichum gossypii var. cephalosporioides, the fungus that causes ramulosis disease of cotton, is widespread in Brazil and can cause severe yield loss. Because weather conditions greatly affect disease development, the objective of this work was to develop weather-based models to assess disease favorability. Latent period, incidence, and severity of ramulosis symptoms were evaluated in controlled environment experiments using factorial combinations of temperature (15, 20, 25, 30, and 35 degrees C) and leaf wetness duration (0, 4, 8, 16, 32, and 64 h after inoculation). Severity was modeled as an exponential function of leaf wetness duration and temperature. At the optimum temperature of disease development, 27 degrees C, average latent period was 10 days. Maximum ramulosis severity occurred from 20 to 30 degrees C, with sharp decreases at lower and higher temperatures. Ramulosis severity increased as wetness periods were increased from 4 to 32 h. In field experiments at Piracicaba, Sao Paulo State, Brazil, cotton plots were inoculated (10(5) conidia ml(-1)) and ramulosis severity was evaluated weekly. The model obtained from the controlled environment study was used to generate a disease favorability index for comparison with disease progress rate in the field. Hourly measurements of solar radiation, temperature, relative humidity, leaf wetness duration, rainfall, and wind speed were also evaluated as possible explanatory variables. Both the disease favorability model and a model based on rainfall explained ramulosis growth rate well, with R(2) of 0.89 and 0.91, respectively. They are proposed as models of ramulosis development rate on cotton in Brazil, and weather-disease relationships revealed by this work can form the basis of a warning system for ramulosis development.

Air trapping: The major factor limiting diaphragm mobility in chronic obstructive pulmonary disease patients

Background and objective: Patients with COPD can have impaired diaphragm mechanics. A new method of assessing the mobility of the diaphragm, using ultrasound, has recently been validated. This study evaluated the relationship between pulmonary function and diaphragm mobility, as well as that between respiratory muscle strength and diaphragm mobility, in COPD patients. Methods: COPD patients with pulmonary hyperinflation (n = 54) and healthy subjects (n = 20) were studied. Patients were tested for pulmonary function, maximal respiratory pressures and diaphragm mobility using ultrasound to measure the craniocaudal displacement of the left branch of the portal vein. Results: COPD patients had less diaphragm mobility than did healthy individuals (36.5 +/- 10.9 mm vs 46.3 +/- 9.5 mm, P = 0.001). In COPD patients, diaphragm mobility correlated strongly with pulmonary function parameters that quantify air trapping (RV: r = -0.60, P < 0.001; RV/TLC: r = -0.76, P < 0.001), moderately with airway obstruction (FEV1: r = 0.55, P < 0.001; airway resistance: r = -0.32, P = 0.02) and weakly with pulmonary hyperinflation (TLC: r = -0.28, P = 0.04). No relationship was observed between diaphragm mobility and respiratory muscle strength (maximal inspiratory pressure: r = -0.11, P = 0.43; maximal expiratory pressure: r = 0.03, P = 0.80). Conclusion: The results of this study suggest that the reduction in diaphragm mobility in COPD patients is mainly due to air trapping and is not influenced by respiratory muscle strength or pulmonary hyperinflation.

Enteric cell proliferation in newborn lambs fed bovine and ovine colostrum

The objective of this study was to investigate immunoglobulin G (IgG) and total serum protein (TP) acquisition in newborn Santa Ines lambs fed Holstein bovine or Santa Ines ovine colostrum as well as the cell proliferation rate in the animals` intestine epithelium. At 0 h and 6 h of life, 12 newborn lambs received 250 mL of bovine 1st milking colostrum (BC) and another 12 animals received 250 mL of ovine 1st milking colostrum (OC). Blood samples were collected at 0, 6, 24. and 72 h of life. Six animals were randomly slaughtered just after birth, without colostrum intake. The other animals were randomly slaughtered at 24 and 72 h. The IgG serum concentration at 6, 24 and 72 h were significantly higher for BC, 16.32 +/- 6.19; 33.80 +/- 5.68 and 27.95 +/- 5.46 mg/mL respectively, compared with OC, 11.31 +/- 6.08, 21.02 +/- 6.53 and 19.88 +/- 7.31 mg/mL BC showed higher (P < 0.05) TP values (7.29 +/- 0.87 and 6.89 +/- 0.30 g/100 mL) at 24 and 72 h in relation to OC (5.73 +/- 1.35 and 5.69 +/- 0.57 g/100 mL). At birth, the animals showed 32.52%, 45.47% and 30.60% cells in division for the duodenum, jejunum and ileum, respectively. At 24 h, the OC animals showed lower (P < 0.0001) mitotic cell percentage in the duodenum (42.12%) and ileum (35.66%) in relation to the BC animals, 46.44% and 39.74%, respectively. At 72 h, a lower (P < 0.0001) rate of proliferation was observed in the duodenum crypts of the OC animals (36.28%) compared with BC (43.18%). The results indicate that this lacteal secretion can accelerate the epithelium renovation process and can be used as an alternative source of IgG for newborn lambs. (C) 2009 Elsevier B.V. All rights reserved.

Allele-Specific Expression of the MAOA Gene and X Chromosome Inactivation in In Vitro Produced Bovine Embryos

During embryogenesis, one of the two X chromosomes is inactivated in embryos. The production of embryos in vitro may affect epigenetic mechanisms that could alter the expression of genes related to embryo development and X chromosome inactivation (XCI). The aim of this study was to understand XCI during in vitro, pre-implantation bovine embryo development by characterizing the allele-specific expression pattern of the X chromosome-linked gene, monoamine oxidase A (MAOA). Two pools of ten embryos, comprised of the 4-, 8- to 16-cell, morula, blastocyst, and expanded blastocyst stages, were collected. Total RNA from embryos was isolated, and the RT-PCR-RFLP technique was used to observe expression of the MAOA gene. The DNA amplicons were also sequenced using the dideoxy sequencing method. MAOA mRNA was detected, and allele-specific expression was identified in each pool of embryos. We showed the presence of both the maternal and paternal alleles in the 4-, 8-to 16-cell, blastocyst and expanded blastocyst embryos, but only the maternal allele was present in the morula stage. Therefore, we can affirm that the paternal X chromosome is totally inactivated at the morula stage and reactivated at the blastocyst stage. To our knowledge, this is the first report of allele-specific expression of an X-linked gene that is subject to XCI in in vitro bovine embryos from the 4-cell to expanded blastocyst stages. We have established a pattern of XCI in our in vitro embryo production system that can be useful as a marker to assist the development of new protocols for in vitro embryo production. Mol. Reprod. Dev. MoL Reprod. Dev. 77: 615-621, 2010. (C) 2010 Wiley-Liss, Inc.

Relationship between occurrence of Panama disease in banana trees of cv. Nanicao and nutrients in soil and leaves

Relationship between occurrence of Panama disease in banana trees of cv. Nanicao and nutrients in soil and leaves The objective of the present work was to verify if the incited symptoms in banana trees cv. Nanicao, belonging to the subgroup Cavendish, in Vale do Ribeira, are related to levels of nutrients in soil and leaves. Sixteen areas in Vale do Ribeira were selected, one half with symptomatic plants and the other with healthy plants. In those areas the third leaf of five plants and the soil near those plants were collected, at depths from 0 to 20 cm and from 20 to 40 cm. At both depths of the sampled soil, levels of Ca, Mg, PO(4)(-3), S and cationic exchange capacity (CEC) were significantly different among the areas, and the low values of these elements were present in the areas containing symptomatic plants. At both depths, Mg, Al and H in relation to CEC were significantly different among the areas, and the low values of Mg and high of Al and H were present in the areas with symptomatic plants. The N, K and S in the leaves were significantly different among the areas. These elements showed low values in the areas containing symptomatic plants. Despite the fact that some amounts of macronutrients of the soil and of the leaves are present only in the areas containing plants of Nanicao with symptoms similar to fusariosis, proof of a possible occurrence of race of the pathogen should be looked for in Vale do Ribeira.

Phenolic compounds and antioxidant activity of seed and skin extracts of red grape (Vitis vinifera and Vitis labrusca) pomace from Brazilian winemaking

The phenolic compounds content and antioxidant activity of seed and skin of pomace from the vinification of grape varieties widely produced in Brazil were investigated with a view to their exploitation as a potential source of natural antioxidants. There was a greater concentration of phenolic compounds in the seeds (2128 to 16,518 mg of catechin equivalents (CE)/100 g) than in the skins (660 to 1839 mg CE/100 g). The highest antioxidant activity values determined as DPPH radical-scavenging ability and ferric reducing-antioxidant power (FRAP) were found for the seeds of the Pinot Noir variety (16,925 mu mol Trolox equivalents (TE)/100 g and 21,492 mu mol Fe(2+)/100 g, respectively) and in the skin extracts of the Isabel variety (3640 mu mol TE/100 g and 4362 mu mol Fe(2+)/100 g, respectively). The skin of Cabernet Sauvignon and Primitivo varieties had the highest contents of anthocyanins (935 and 832 mg/100 g, respectively). The grape seed extracts were rich in oligomeric and polymeric flavanols. The data suggested that grape seed and skin extracts may be exploited as antioxidant agents. (C) 2011 Elsevier Ltd. All rights reserved.

Restoration of Pattern Recognition Receptor Costimulation to Treat Chromoblastomycosis, a Chronic Fungal Infection of the Skin

Chromoblastomycosis is a chronic skin infection caused by the fungus Fonsecaea pedrosoi. Exploring the reasons underlying the chronic nature of F. pedrosoi infection in a murine model of chromoblastomycosis, we find that chronicity develops due to a lack of pattern recognition receptor (PRR) costimulation. F. pedrosoi was recognized primarily by C-type lectin receptors (CLRs), but not by Toll-like receptors (TLRs), which resulted in the defective induction of proinflammatory cytokines. Inflammatory responses to F. pedrosoi could be reinstated by TLR costimulation, but also required the CLR Mincle and signaling via the Syk/CARD9 pathway. Importantly, exogenously administering TLR ligands helped clear F. pedrosoi infection in vivo. These results demonstrate how a failure in innate recognition can result in chronic infection, highlight the importance of coordinated PRR signaling, and provide proof of the principle that exogenously applied PRR agonists can be used therapeutically.

Standardization and determination of photostability of leaf extracts of Pothomorphe umbellata L. Miq (pariparoba) and evaluation of the inhibition in vitro of metalloproteinases 2 and 9 in skin

Most researches that have been done until today about the beneficial effects of hariparoha (Pothomorphe umbellata L. Miq) have been done with root extract of this species, but the use in large scale would compromise the sustainable exploration of this natutral resource. In this sense, the utilization of pariparoha leaves, substituting the roots, in the cosmetic industry does not put in risk the existence of the species. In this work the concentration of 4-nerolidyl-cathecol (4-NC) in leaf extract was determined by the analytical methodology validated in our laboratory. The concentration of 4-NC in leaf extract was around 30% less than that of root extract, obtained in the same way. Concerning the study of the photostability of a leaves extract solution containing 4-NC did not demonstrate meaningful alterations in the spectrometry, profile after 2 hours of exposure under UVB radiation, showing its stability under this conditions. Metalloproteinases (MMPs) cure endopeptidases that are zinc-dependent, involved in remodeling extracellular matrix (ECM), that are important in the appearance of typical photoaging wrinkles. In this work the capacity of leaf extract of P. umbellata to inhibit MMP-2 and 9 activities of hairless mouse skin in vitro by zymography gel was also evalutated. The leaf extract (0,1 mg/mL) inhibit in 80% activity of this enzymes, according to the densitometric zymography evaluation.

Increased class A scavenger receptor and glomerular lipid precede mesangial matrix expansion in the bGH mouse model

Objective: Elevated neutral lipid content and mRNA expression of class A scavenger receptor (SRA) have been found in the renal cortex of the bovine growth hormone (bGH) mouse model of progressive glomerulosclerosis (GS). We hypothesize that the increased expression of SRA precedes glomerular scarring in this model. Design: Real time RT-PCR and immunofluorescence were employed to measure SRA and collagen types I and IV in the bGH transgenic and control mice at 5 and 12 weeks (wk) of age to determine the chronology of change in SRA expression in relation to glomerular scarring. Alternative mechanisms for increasing glomerular lipid were assessed by measuring mRNA expression levels of low-density lipoprotein receptor (LDL-r), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), and ATP-binding cassette transporter A1 (ABCA1). In addition, the involvement of macrophages in early GS was assessed by CD68 mRNA expression in kidney cortex. Results: Both mRNA and protein levels of SRA were significantly increased in 5-wk bGH compared with control mice, whereas the expression of collagen I and IV was unaltered. Unchanged levels of LDL-r and HMGR mRNA indicate that neither regulated cholesterol uptake via LDL-r nor the cholesterol synthetic pathway played a role in the early lipid increase. The finding of increased ABCA1 expression was an indicator of excess intracellular lipid in the renal cortex of bGH mice at 5 wk. CD68 expression in bGH did not differ significantly from that of controls at 5 wk suggesting that cortical macrophage infiltration was not increased in bGH mice at this time point. Conclusion: An early increase in SRA mRNA and protein expression in the bGH kidney precedes glomerular scarring and is independent of macrophage influx. Published by Elsevier Ltd. on behalf of Growth Hormone Research Society.

Study of sunless tanning formulas using molted snake skin as an alternative membrane model

Sunless tanning formulas have become increasingly popular in recent years for their ability to give people convincing tans without the dangers of skin cancer. Most sunless tanners currently on the market contain dihydroxyacetone (DHA), a keto sugar with three carbons. The temporary pigment provided by these formulasis designed to resemble a UV-induced tan. This study evaluated the effectiveness of carbomer gels and cold process self emulsifying bases on skin pigmentation, using different concentrations of a chemical system composed of DHA and N-acetyl tyrosine, which are found in moulted snake skins and their effectiveness was tested by Mexameter (R) MX 18. Eight different sunless tanning formulas were developed, four of which were gels and four of which were emulsions (base, base plus 4.0%, 5.0% and 6.0% (w/w) of a system of DHA and N-acetyl tyrosine). Tests to determine the extent of artificial tanning were done by applying 30 mg cm(-2) of each formula onto standard sizes of moulted snake skin (2.0 cm x 3.0 cm). A Mexameter (R) MX 18 was used to evaluate the extent of coloration in the moulted snake skin at T(0) (before the application) and after 24, 48, 72, 168, 192 and 216 h. The moulted snake skins can be used as an alternative membrane model for in vitro sunless tanning efficacy tests due to their similarity to the human stratum corneum. The DHA concentration was found to influence the initiation of the pigmentation in both sunless tanning systems (emulsion and gel) as well as the time required to increases by a given amount on the tanning index. In the emulsion system, the DHA concentration also influenced the final value on the tanning index. The type of system (emulsion or gel) has no influence on the final value in the tanning index after 216 h for samples with the same DHA concentration.

SENSORY APPROACH TO MEASURE FRAGRANCE INTENSITY ON THE SKIN

Sensory analysis is a precise and descriptive measuring technique to quantify human responses to stimuli. Odor, one of these stimuli, is basically the result of the interaction between a chemical stimulus and the olfactory receptor system, which can be described using a number of different dimensions and measures through different sensory tests: threshold, intensity and quality. To measure fragrance performance on the skin, these parameters are very important, but the main attribute to be evaluated is substantivity, thus the importance of the sensory scale chosen to measure perception, discriminate different intensities and determine the substantivity of the fragrance. Some studies comparing the labeled magnitude scale (LMS) with other magnitude scales and their derivations showed that the use of the LMS scale to measure fragrance intensity could semantically understand the intensity of the stimulus. Tests using this scale confirmed the applicability and efficiency of the LMS. PRACTICAL APPLICATIONS The objective of this article is to review the techniques used to measure odor and fragrance intensities applied on the skin. The review shows general sensory techniques and their goals, the newest olfactory mechanism and its contribution to sensory evaluation and which attributes should be considered to measure odor. Substantivity/retentivity or longevity can be regarded as the most important attributes if you want to measure fragrance performance on the skin. Past studies showed different scales tested to measure odor, and some of them demonstrated that the labeled magnitude scale is very suitable to measure fragrance on the skin.

In vitro safety assessment of papain on human skin: A qualitative Light and Transmission Electron Microscopy (TEM) study

Papain is a thiol proteolytic enzyme widely used in dermatology that found applications in wound treatment. Recently, papain was also used as absorption enhancer which can modify the peptide/ protein material in the bilayer domain. We investigated papain safety using human skin that was exposed to papain in vitro at different times: 4, 24 and 48 hours. The samples were examined using Light and Transmission Electron Microscopy (TEM) to study of the mechanisms involved in enhancer-skin interaction. After 24 hours, changes occurred in corneosomes. However, samples of 48 hours did not show major changes in agreement with the control. These findings indicated that papain could be used safely onto the skin.

Cytotoxicity and Endothelial Cell Adhesion of Lyophilized and Irradiated Bovine Pericardium Modified With Silk Fibroin and Chitosan

Grafts of biological tissues have been used since the 1960s as an alternative to the mechanical heart prostheses. Nowadays, the most consolidated treatment to bovine pericardial (BP) bioprostheses is the crosslinking with glutaraldehyde (GA), although GA may induce calcification in vivo. In previous work, our group demonstrated that electron beam irradiation applied to lyophilized BP in the absence of oxygen promoted crosslinks among collagen fibers of BP tissue. In this work, the incorporation of silk fibroin (SF) and chitosan (CHIT) in the BP not treated with GA was studied. The samples were irradiated and then analyzed for their cytotoxicity and the ability of adhesion and growth of endothelial cells. Initially, all samples showed cytotoxicity. However, after a few washing cycles, the cytotoxicity due to acetic acid and ethanol residues was removed from the biomaterial making it suitable for the biofunctional test. The samples modified with SF/CHIT and electron beam irradiated favored the adhesion and growth of endothelial cells throughout the tissue.