Plant biostimulants: a review on the processing of macroalgae and use of extracts for crop management to reduce abiotic and biotic stresses

A biostimulant is an organic material that, when applied in small quantities, enhances plant growth and development such that the response cannot be attributed to the application of traditional plant nutrients. This review is aimed at highlighting developments in the processing of macroalgae for agricultural biostimulants (AB), summarising the biologically active components of brown macroalgae and examining the factors supporting the use of macroalgal AB for managing abiotic and biotic stresses in crop plants. The policy drivers supporting the use of macroalgal-derived ABs in agriculture are also emphasised. We examine the use of macroalgal ABs in crop production and evaluated the benefits of seed priming, foliar application, soil drenches and hydroponic treatments. The use of macroalgal ABs on crop plants can generate multiple benefits with reported effects including enhanced rooting, higher crop and fruit yields, freezing, drought and salt tolerance, enhanced photosynthetic activity and resistance to fungi, bacteria and virus. ABs can be applied as an alternative, or used in conjunction with synthetic crop protection products and plant growth regulators, and may have a role in maintaining crop production levels, health and quality in the future when many active ingredients will be lost to the industry due to changes in European Union regulations. Worldwide, macroalgae remain largely unexploited, we highlight some of the future research and development priorities.     

Relationship between cytokine concentrations and the level of antibodies to neuronal proteins as dependent on the severity of mercury neurotoxicity

Serum levels of cytokines and antibodies (ABs) to neuronal proteins and their relationship were studied in patients with chronic mercury intoxication (CMI) varying in severity. CMI development was observed to worsen the imbalance of pro- and anti-inflammatory cytokines, and the cytokine levels proved to reflect the severity of the pathological process. The relationships (positive and negative correlations) between cytokine and neuronal AB concentrations and their dependence on the severity of neurointoxication with elemental mercury vapor were assumed to indicate that a distorted cytokine regulation of autoimmune processes plays an important role in mercury neurotoxicity.     

Asbestos bodies in bronchoalveolar lavage fluid. A study of 20 asbestos-exposed individuals and comparison to patients with other chronic interstitial lung diseases

We studied the asbestos body (AB) content of bronchoalveolar lavage fluid from 20 patients with a history of occupational asbestos exposure, 31 patients with sarcoidosis and 5 patients with idiopathic pulmonary fibrosis. The cellular lavage pellet was digested in sodium hypochlorite and filtered onto Nuclepore filters for AB quantification by light microscopy. ABs were found in 15 of 20 asbestos-exposed individuals, 9 of 31 sarcoidosis cases and 2 of 5 patients with idiopathic pulmonary fibrosis. There was a statistically significant difference in the number of ABs per million cells recovered or per milliliter of recovered lavage fluid in the asbestos-exposed group as compared to the other categories of chronic interstitial lung disease. The highest levels occurred in patients with asbestosis. Large numbers of asbestos bodies in the lavage fluid (greater than 1 AB/10(6) cells) were indicative of considerable occupational asbestos exposure, whereas occasional bodies were a nonspecific finding.     

Diversity of integrase-hydrolyzing IgGs and IgMs from sera of HIV-infected patients

It was previously shown that small fractions of IgGs and IgMs from the sera of AIDS patients specifically hydrolyze only HIV integrase (IN) but not many other tested proteins. Here we present evidence showing that these IgGs and IgMs are extreme catalytically heterogeneous. Affinity chromatography on IN-Sepharose using elution of IgGs (or IgMs) with different concentration of NaCl and acidic buffer separated catalytic antibodies (ABs) into many AB subfractions demonstrating different values of K _m for IN and k _cat. Nonfractionated IgGs and IgMs possess serine-, thiol-, acidiclike, and metal-dependent proteolytic activity. Metal-dependent activity of abzymes increases in the presence of ions of different metals. In contrast to canonical proteases having one pH optimum, initial nonfractionated IgGs and IgMs demonstrate several optima at pH from 3 to 10. The data obtained show that IN-hydrolyzing polyclonal IgG and IgM of HIV-infected patients are cocktails of anti-IN ABs with different structure of the active centers possessing various affinity to IN, pH optima, and relative rates of the specific substrate hydrolysis.     

Maintenance of the differentiated state in skeletal muscle: activation of v-Src disrupts sarcomeres in quail myotubes

We have used quail skeletal myotubes expressing a temperature-sensitive allele of the v-src oncogene to address the issue of the homeostasis of sarcomeric myofibrils in differentiated muscle cells. Reactivation of the v-Src tyrosine kinase by shifting the cultures to the permissive temperature leads within minutes to the formation of F-actin-containing bodies (ABs), that originate in the ventral region of the myotubes and increase in number concomitantly with the dismantling of the I-Z-I complex of the sarcomeres. This process is detailed by confocal and electron microscopy. Indirect immunofluorescence reveals that ABs contain muscle-specific protein isoforms associated with the I-Z-I complexes and vinculin, a component of the cytoskeletal network. Anti- phosphotyrosine antibodies label proteins in ABs and Z-discs. Evidence is presented indicating that this phenomenon specifically depends on the persistent activation of v-Src, rather than on a general increase in phosphotyrosine content such as that induced by vanadate. AB formation is prevented by activation of protein kinase C by phorbol ester or by treatment with the kinase inhibitor 2-aminopurine, without any detectable effect on tyrosine phosphorylation. Taken together these findings indicate that phosphorylation of specific target proteins by v- Src, although necessary, is not sufficient per se to induce AB formation. In addition, the signal transduction cascade that culminates in MAP kinase activation and its nuclear translocation is activated both by v-Src and phorbol ester, and is relatively unaffected by 2- aminopurine. These findings imply that both phorbol esters and 2- aminopurine operate, at least in part, at the level of alternative pathways that may diverge upstream of the MAP kinase and are presumably mediating the early effects of v-Src on the differentiated phenotype.     

Autoantigens are translocated into small apoptotic bodies during early stages of apoptosis

A dysregulation of apoptosis or an ineffective clearance of apoptotic material is suspected to be involved in the pathogenesis of systemic lupus erythematodes. Subcellular fragments such as apoptotic bodies (ABs) have been recognized as modulators of intercellular communication and immune function. In this context, we have been interested whether nuclear and cytoplasmic antigens are relocated into ABs. In the present study, we characterized ABs isolated from apoptozing lymphoblasts. We found an accumulation of the linker-histone (histone 1) as well as the core-histones (histone 2A, histone 2B, histone 3, histone 4) in ABs. Further, they contained DNA, RNA and the ribonuclear protein La/SSB. Proteins such as cytochrome c, HSP 70, prohibitin, p53, nuclear matrix antigen or lamin B were excluded from ABs. The content of ABs differed from that observed in membrane microparticles isolated from viable cells. Formation of ABs occurred early during apoptosis. It was observed before DNA-degradation or phosphatidylserine exposure was detected. ABs were engulfed by monocyte-derived phagocytes. These findings suggest that immunogenic molecules are actively translocated into ABs followed by a rapid engulfment of the latter by environmental phagocytes. In autoimmune diseases, a defect in the clearance of ABs or AB formation may contribute to the development of autoimmunity.     

Polyreactivity of natural antibodies: Exchange by HL-fragments

The polyreactivity of binding (formation of antibody (AB) complexes not only with specific but also with foreign antigens) is a widespread phenomenon that in some cases can be caused by a conformational lability of the antigen-binding sites of antibodies (which increases upon treatment with various destabilizing agents) and leads to AB binding with very different antigens. Some ABs exist as dimers of the initial ABs and their idiotypes (or anti-idiotypes) capable of producing intramolecular cyclic complexes with features of polyreactants. Another mechanism of binding polyreactivity is an exchange in blood by halves of IgG4 molecules (HL-fragments) against various antigens. Also, for the first time catalytic polyfunctionality of human milk ABs has been detected, which is caused by an exchange by HL-fragments between molecules of λ- and κ-IgG (IgG1-IgG4) and also by λ- and κ-sIgA against different antigens with formation of very different chimeric antibodies. This review considers all possible pathways of formation of polyspecific immunoglobulins and their biological functions described in the literature, as well as mechanisms of binding polyreactivity and catalytic polyfunctionality of natural antibodies.     

The sensitivity of detection of asbestos bodies in sputa and bronchial washings

While asbestos bodies (ABs) in sputum and/or bronchial washings are highly specific markers for significant asbestos exposure, comparison of the sensitivity between sputum cytology and bronchial washing cytology for the detection of ABs had not been documented. Review of the files of the Cytopathology Laboratory, Methodist Hospital, Houston, Texas, for the period 1973 to 1984 identified 11 patients with slides available for review who (1) had been examined by both sputum cytology and bronchial washing cytology and (2) had at least one specimen positive for ABs. Of the 11 evaluable cases, all had ABs in the bronchial washings but ony 6 had ABs in the sputum. In addition, iron stain (e.g., the Prussian blue stain) was found to be more sensitive than the Papanicolaou stain for the detection of ABs in these cases. These findings indicate that iron-stained bronchial washing specimens should be preferred for the cytologic detection of asbestos exposure.     

Nuclear envelope associated protein that binds telomeric DNAs

Rana temporaria oocytes at the 6th diplotene stage of maturation contain a special structure, the karyosphere capsule, with chromosomes covered and detached from the nuclear envelope (NE), though at the previous stage the telomeres were attached to the membrane, as characteristic of germ cells. The DNA-protein complexes from band shift assays with proteins extracted from oocyte NEs and telomeric DNA fragment (T(2)G(4))(130) were isolated and injected into a guinea pig. In the present paper the only protein of 70 kDa recognized by antibody (AB) in the NE is named the Membrane Telomere Binding Protein (MTBP). Western blots with guinea pig AB and AB against telobox peptide from TRF2 show that protein of 60 kDa (probably TRF1) belongs to the chromatin, but MTBP (TRF2 according to immunoprecipitation) belongs to the NE. In the somatic cell nuclei both proteins are present and recognized by AB against telobox peptide, but AB raised recognize only MTBP/TRF2 due to the epitope different from telobox. Combined in situ hybridization with the vertebrate telomeric DNA sequences (T(2)AG(3))(135) and immunocytochemistry with the MTBP AB showed them to be colocalized within the mouse nucleus. As it was shown by immunofluorescense of NE spread, MTBP is organized in a distinct pattern that looks like a network made of double-dots. Electron microscope immunogold staining with both ABs showed that the protein is localized on the outer surface of the oocyte NE within cup-like structures attached to the membrane. This is the first clear evidence of a protein, which could be responsible for the attachment of telomeres to the nuclear membrane.     

The effect of polar auxin transport on adventitious branches formation in Gracilaria lichenoides in vitro

Seaweed tissue culture (STC) is an important micropropagation tool that has been applied for strain improvement, micropropagation and genetic engineering. Because the mechanisms associated with STC are poorly understood, its application to these organisms lags far behind that of tissue culture propagation of higher plants. Auxin, calcium (Ca²⁺) and hydrogen peroxide (H₂O₂) fluxes all play key roles during plant growth and development. In this study, we therefore measured indole‐3‐acetic acid, Ca²⁺ and H₂O₂ fluxes of Gracilaria lichenoides explants during adventitious branches (ABs) formation for the first time using noninvasive micro‐test technology. We confirmed that polar auxin transport (PAT) also occurs in the marine red alga G. lichenoides. We additionally found that N‐1‐naphthylphthalamic acid may suppress auxin efflux via ABCB1 transporters and then inhibit ABs formation from the apical region of G. lichenoides segments. The involvement of Ca²⁺ and H₂O₂ fluxes in PAT‐mediated AB formation in G. lichenoides was also investigated. We propose that complex feedback among Ca²⁺, H₂O₂ and auxin signaling and response systems may occur during ABs polar formation in G. lichenoides explants, similar to that in higher plants. Our results provide innovative insights that should aid future elucidation of mechanisms operative during STC.     

Some pathophysiological aspects of vibration-induced white finger

The level of sympathetic nervous activity was assessed by evaluating cardiovascular responses to a cold test in 63 vibration-exposed workers (50 subjects without vibration white finger (VWF) and 13 subjects at stages 1 and 2 of VWF) and in 41 controls. Blood pressure, heart rate, systolic time intervals and the skin temperature of the third finger of the right hand were monitored throughout the cold test period. Basal urinary excretion of free catecholamines and platelet aggregation indices both in vitro and in vivo were also determined in all subjects. Systolic time intervals such as electromechanical systole index (QS2I) and left ventricular ejection time index (LVETI) were found to be shorter in the vibration-exposed workers with and without VWF than in the controls, both at rest and during cold exposure and recovery (p less than 0.001). A significant inverse relationship between urinary free catecholamines and the duration of LVETI was observed under resting conditions (p less than 0.03). The recovery rate of the basal finger skin temperature after local cooling was slower in vibration workers with VWF than in those without VWF (p less than 0.05) and in the controls (p less than 0.001). Platelet aggregation indices were similar in all groups studied. The results suggest that the level of sympathetic nervous activity is higher in vibration-exposed workers than in controls. In subjects with VWF, sympathetic hyperactivity in combination with local factors such as vibration-induced hyperresponsiveness to cold of the digital vessels may be responsible for finger blanching attacks.(ABSTRACT TRUNCATED AT 250 WORDS)     

Importance of the sporotrichosis asteroid body for the rapid diagnosis of sporotrichosis

Eighty patients with cutaneous sporotrichosis were studied between 1985 and 1996. The investigation of asteroid bodies (AB) was done by direct microscopic slides examination of pus obtained from the lesions. Patients were divided into two groups: 32 consulting before 1989, and 48 consulting after 1990. In the first group, material was obtained as usual by simple digital pressure of the most productive lesion, and then wet preparation microscopic examination was performed. Fourteen patients with AB were found in this group (43.75%). In the second group the initial pus was discarded and new samples were taken more deeply, and examined up to five slides for each patient. The slides were carefully examined at light microscope. Fourty five patients with AB were detected in this group (93.75%). All eighty samples were cultured and all of them were positive for Sporothrix schenckii. The change of methodology to obtain the samples and the exhaustive observations, increased the possibility of AB detection. ABs are of great diagnostic value and might be of importance to initiate treatment before reporting culture.     

Quantitative and qualitative changes in protein biosynthesis induced by hypoxia and transplantation of embryonic nerve tissue into the brain of adult mammals

The changes in biochemical processes in brain cortex in rats with experimental hypoxia and hypoxia with consequent transplantation of embryonic nervous tissue into brain of adults have been studied. A small increase (2-3 times) in incorporation of biosynthesis precursors was observed as a result of transplantation both in normal and in hypoxic rats. These changes could be observed 100 days after the transplantation. These changes in biosynthesis led to selective increase in the amounts of 40-45 and 35-39 kDa proteins, which are characteristic both for local trauma caused by transplantation and for general one caused by hypoxia. The effect observed may be explained as a reaction of nervous cells on damage, and not on the presence of an embryonic brain transplant.     

Responses of aerobic anoxygenic phototrophic bacteria to algal blooms in the East China Sea

Aerobic anoxygenic phototrophic bacteria (AAPB) are a new functional group of heterotrophic bacteria capable of phototrophy, and are suggested to be closely related with phytoplankton. However, less known is the relationship between AAPB and dominant phytoplankton populations. In this tudy, the responses of AAPB to algal blooms (ABs) in the AB-frequent-occurrence area of the East China Sea were investigated during four cruises from March to June 2005, using an advanced ‘Time-series observation-based cyanobacteria-calibrated InfraRed Epifluorescence Microscopy (TIREM)’ approach. Generally, total bacterial abundances at the bloom stations were higher than or similar to those at the non-bloom stations during the same time period. Interestingly, the responses of AAPB to ABs seemed to be more diverse and complex. AAPB abundance was higher at the stations with ABs where Thalassiosira curviseriata Takano and Skeletonema costatum (Greville) Cleve, Noctiluca scintillans (Macartney) Kofoid et Swezy, or Prorocentrum donghaiense Lu and Karenia mikimotoi Hansen co-dominated than those at the non-bloom stations during the same time period. However at the stations with a bloom of Akashiwo sanguinea Hansen, AAPB abundance only accounted for ~20% of the average abundance of AAPB at the non-bloom stations. In addition, variations of AAPB’s proportion to total bacterial abundance (AAPB%) in response to ABs basically followed AAPB abundance. Overall, our results suggest that the responses of AAPB to ABs are AB-species specific and somewhat independent of chlorophyll a concentration.     

Differential Effects of Antibiotic Therapy on the Structure and Function of Human Gut Microbiota

The human intestinal microbiota performs many essential functions for the host. Antimicrobial agents, such as antibiotics (AB), are also known to disturb microbial community equilibrium, thereby having an impact on human physiology. While an increasing number of studies investigate the effects of AB usage on changes in human gut microbiota biodiversity, its functional effects are still poorly understood. We performed a follow-up study to explore the effect of ABs with different modes of action on human gut microbiota composition and function. Four individuals were treated with different antibiotics and samples were taken before, during and after the AB course for all of them. Changes in the total and in the active (growing) microbiota as well as the functional changes were addressed by 16S rRNA gene and metagenomic 454-based pyrosequencing approaches. We have found that the class of antibiotic, particularly its antimicrobial effect and mode of action, played an important role in modulating the gut microbiota composition and function. Furthermore, analysis of the resistome suggested that oscillatory dynamics are not only due to antibiotic-target resistance, but also to fluctuations in the surviving bacterial community. Our results indicated that the effect of AB on the human gut microbiota relates to the interaction of several factors, principally the properties of the antimicrobial agent, and the structure, functions and resistance genes of the microbial community.     

Experimental approaches to the study of permeability of the blood-brain barrier for native autogenous proteins in chicken ontogenesis

The composition and distribution of serum proteins in blood, brain vesicles liquid, and nervous tissue has been studied in chicken embryos at 4-20 day of incubation using electrophoresis, immunoelectrophoresis, and fluorescent antibodies. At the 4-5 day of incubation, a difference in the protein composition of brain vesicles liquid and blood serum is apparent. This indicates that the border membrane of brain vesicles plays a part of the barrier. The vessels, preventing the transport of serum proteins to the nervous tissue, which are characteristic of hematoencephalic barrier of adult animals, develop in the embryo brain at the end of incubation period.     

Effect of ATP on protein synthesis in cultured nerve tissue of the edible snail]

External ATP in concentrations of 10(-6)--10(-3) M is shown to stimulate the label incorporation from intracellular labeled pool of 14C-leucine into proteins of mollusc nervous tissue. The maximum effect (by 45% higher than in control) is observed at the 10(-5) ATP concentration. In solutions with high concentration of bivalent ions, ATP action increases by 10--15%. Being incubated for an hour in physiological solutions without energic substrates nervous tissue loses 30--50% of labeled amino acids. Outwashing of 14C-leucine depends only a little on the bivalent ion concentration in the external solution and on the presence of helating agents. Addition of 10(-4) M ATP into the solution, completely inhibits the washing of amino acids out of tissue. At low bivalent ion concentrations 14C-leucine incorporation into nervous tissue in the presence of ATP changes inversely to the ATP concentration: low ATP concentrations (10(-5)--10(-6) M) activate label incorporation by 60--40%, whereas high concentrations lead to the corresponding inhibition. This inhibition is due to helating action of ATP.     

The "other" respiratory effect of opioids: suppression of spontaneous augmented ("sigh") breaths

The purpose of this study was to examine the effects of a clinically relevant opioid on the production of augmented breaths (ABs) in unanesthetized animals breathing normal room air, using a dosage which does not depress breathing. To do this we monitored breathing noninvasively, in unrestrained animals before and after subcutaneous injection of either morphine, or a saline control. The effect of ketamine/xylazine was also studied to determine the potential effect of an alternative sedative agent. Last, the effect of naloxone was studied to determine the potential influence of endogenous opioids in regulating the normal incidence of ABs. Morphine (5 mg/kg) had no depressive effect on breathing, but completely eliminated ABs in all animals in room air (P = 0.027). However, when animals breathed hypoxic air (10% O(2)), animals did express ABs, although their incidence was still reduced by morphine (P < 0.001). This was not a result of sedation per se, as ABs continued at their normal rate in room air during sedation with ketamine. Naloxone had no effect on breathing or AB production, and so endogenous opioids are not likely involved in regulating their rate of production under normal conditions. Our results show that in unanesthetized animals breathing normal room air, a clinically relevant opioid eliminates ABs, even at a dose that does not cause respiratory depression. Despite this, hypoxia-induced stimulation of breathing can facilitate the production of ABs even with the systemic opioid present, indicating that peripheral chemoreceptor stimulation provides a potential means of overcoming the opioid-induced suppression of these respiratory events.     

Molecular evolution of the mammalian alpha 2B adrenergic receptor

The alpha 2B adrenergic receptor (A2AB) is a heptahelical G protein-coupled receptor for catecholamines. We compared the almost complete coding region (about 1,175 bp) of the A2AB gene from 48 mammalian species, including eight newly determined sequences, representing all the 18 eutherian and two marsupial orders. Comparison of the encoded proteins reveals that residues thought to be involved in agonist binding are highly conserved, as are the regions playing a role in G protein-coupling. The three extracellular loops are generally more variable than the transmembrane domains and two of the intracellular loops, indicating a lower functional constraint. However, the greatest variation is observed in the very long, third intracellular loop, where only a few residues and a polyglutamyl tract are preserved. Although this polyglutamyl domain displays a great variation in length, its presence in all described A2ABs confirms its proposed role in agonist-dependent phosphorylation of the third intracellular loop. Phylogenetic analyses of the A2AB data set, including Bayesian methods, recognized the superordinal clades Afrotheria, Laurasiatheria, and Euarchontoglires, in agreement with recent molecular evidence, albeit with lower support. Within Afrotheria, A2AB strongly supports the paenungulate clade and the association of the continental African otter shrew with Malagasy tenrecs. Among Laurasiatheria, A2AB confirms the nesting of whales within the artiodactyls, as a sister group to hippopotamus. Within the Euarchontoglires, there is constant support for rodent monophyly.