Cultivable gut bacteria provide a pathway for adaptation of Chrysolina herbacea to Mentha aquatica volatiles.

BACKGROUND: A chemical cross-talk between plants and insects is required in order to achieve a successful co-adaptation. In response to herbivory, plants produce specific compounds, and feeding insects respond adequately7 to molecules produced by plants. Here we show the role of the gut microbial community of the mint beetle Chrysolina herbacea in the chemical cross-talk with Mentha aquatica (or watermint). RESULTS: By using two-dimensional gas chromatography-mass spectrometry we first evaluated the chemical patterns of both M. aquatica leaf and frass volatiles extracted by C. herbacea males and females feeding on plants, and observed marked differences between males and females volatiles. The sex-specific chemical pattern of the frass paralleled with sex-specific distribution of cultivable gut bacteria. Indeed, all isolated gut bacteria from females belonged to either α- or γ-Proteobacteria, whilst those from males were γ-Proteobacteria or Firmicutes. We then demonstrated that five Serratia marcescens strains from females possessed antibacterial activity against bacteria from males belonging to Firmicutes suggesting competition by production of antimicrobial compounds. By in vitro experiments, we lastly showed that the microbial communities from the two sexes were associated to specific metabolic patterns with respect to their ability to biotransform M. aquatica terpenoids, and metabolize them into an array of compounds with possible pheromone activity. CONCLUSIONS: Our data suggest that cultivable gut bacteria of Chrysolina herbacea males and females influence the volatile blend of herbivory induced Mentha aquatica volatiles in a sex-specific way.

Mepolizumab in Severe Pediatric Asthma: Certainties and Doubts through a Single-Center Experience and Review of the Literature.

BACKGROUND: Although, in most children with asthma, good symptom control is achieved with a low to moderate dose of inhaled corticosteroids, a small group of patients still experiences frequent symptoms, and even severe exacerbations, impairment of lung function, and reduced quality of life. Some of these subjects with severe asthma require biologic drugs as add-on therapy. In the past decade, numerous monoclonal antibodies have been approved for children or adolescents with severe asthma, in addition to their increasing use in adult asthma. However, the available evidence on how to select the most appropriate biologic based on a single patient's clinical, functional, and laboratory characteristics is still scant, and is insufficient to guide clinicians in the decision-making process of a personalized treatment. MATERIALS AND METHODS: We report a case series of four patients with severe eosinophilic asthma treated with mepolizumab, an anti-interleukin-5 monoclonal antibody, and review the existing literature on this treatment in children and adolescents. RESULTS: Our patients, all with blood eosinophilia and elevated fractional exhaled nitric oxide levels, developed poor symptom control despite prolonged treatment with high-dose inhaled corticosteroids plus a second controller, addressing the addition of a biologic drug. In all of them, a 12-month treatment with subcutaneous mepolizumab showed a reduction in the blood eosinophil count and in asthma exacerbations, as well as an improvement on the Asthma Control Test. The results of the literature search focused on the strengths and limitations of the pediatric use of mepolizumab and highlighted the areas worthy of further research. CONCLUSIONS: Mepolizumab has proven effective in improving symptom control in pediatric patients with severe asthma. Additional well-powered clinical trials will be helpful in developing evidence-based guidelines regarding biologic drugs in the pediatric population.

Mitochondrial Neurodegenerative Diseases: Three Mitochondrial Ribosomal Proteins as Intermediate Stage in the Pathway That Associates Damaged Genes with Alzheimer's and Parkinson's.

Currently, numerous research endeavors are dedicated to unraveling the intricate nature of neurodegenerative diseases. These conditions are characterized by the gradual and progressive impairment of specific neuronal systems that exhibit anatomical or physiological connections. In particular, in the last twenty years, remarkable efforts have been made to elucidate neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, despite extensive research endeavors, no cure or effective treatment has been discovered thus far. With the emergence of studies shedding light on the contribution of mitochondria to the onset and advancement of mitochondrial neurodegenerative disorders, researchers are now directing their investigations toward the development of therapies. These therapies include molecules designed to protect mitochondria and neurons from the detrimental effects of aging, as well as mutant proteins. Our objective is to discuss and evaluate the recent discovery of three mitochondrial ribosomal proteins linked to Alzheimer's and Parkinson's diseases. These proteins represent an intermediate stage in the pathway connecting damaged genes to the two mitochondrial neurological pathologies. This discovery potentially could open new avenues for the production of medicinal substances with curative potential for the treatment of these diseases.

Treatment of a Severe Form of Euglycemic Ketoacidosis in a Patient Treated with SGLT-2 Inhibitors with the Aid of Somatostatin.

Currently, the use of SGLT2 inhibitors is becoming more widespread, both for their role in controlling diabetes, and for their pleiotropic effects on glomerular hyperfiltration and heart failure. Along with their positive effects, these drugs can lead to various complications, the most severe being euglycemic ketoacidosis. The clinical case we have reported precisely describes this potentially serious complication which occurred in a 47-year-old patient who had been on SGLT2 inhibitor therapy for 5 years. In the resolution of this case we used, in addition to standard therapy, the continuous infusion of somatostatin, resulting in a rapid resolution of ketoacidosis and an improvement in the clinical condition.

Mitochondrial ribosomal protein genes connected with Alzheimer's and tellurite toxicity.

Mitochondrial diseases are a group of genetic disorders characterized by dysfunctional mitochondria. Within eukaryotic cells, mitochondria contain their own ribosomes, which synthesize small amounts of proteins, all of which are essential for the biogenesis of the oxidative phosphorylation system. The ribosome is an evolutionarily conserved macromolecular machine in nature both from a structural and functional point of view, universally responsible for the synthesis of proteins. Among the diseases afflicting humans, those of ribosomal origin - either cytoplasmic ribosomes (80S) or mitochondrial ribosomes (70S) - are relevant. These are inherited or acquired diseases most commonly caused by either ribosomal protein haploinsufficiency or defects in ribosome biogenesis. Here we review the scientific literature about the recent advances on changes in mitochondrial ribosomal structural and assembly proteins that are implicated in primary mitochondrial diseases and neurodegenerative disorders, and their possible connection with metalloid pollution and toxicity, with a focus on MRPL44, NAM9 (MNA6) and GEP3 (MTG3), whose lack or defect was associated with resistance to tellurite. Finally, we illustrate the suitability of yeast Saccharomyces cerevisiae (S. cerevisiae) and the nematode Caenorhabditis elegans (C. elegans) as model organisms for studying mitochondrial ribosome dysfunctions including those involved in human diseases.

Chemical Composition, Fatty Acid and Mineral Content of Food-Grade White, Red and Black Sorghum Varieties Grown in the Mediterranean Environment.

Grain sorghum (Sorghum bicolor) is a gluten-free cereal grown around the world and is a food staple in semi-arid and subtropical regions. Sorghum is a diverse crop with a range of pericarp colour including white, various shades of red, and black, all of which show health-promoting properties as they are rich sources of antioxidants such as polyphenols, carotenoids, as well as micro- and macro-nutrients. This work examined the grain composition of three sorghum varieties possessing a range of pericarp colours (white, red, and black) grown in the Mediterranean region. To determine the nutritional quality independent of the contributions of phenolics, mineral and fatty acid content and composition were measured. Minor differences in both protein and carbohydrate were observed among varieties, and a higher fibre content was found in both the red and black varieties. A higher amount of total saturated fats was found in the white variety, while the black variety had a lower amount of total unsaturated and polyunsaturated fats than either the white or red varieties. Oleic, linoleic, and palmitic were the primary fatty acids in all three analysed sorghum varieties. Significant differences in mineral content were found among the samples with a greater amount of Mg, K, Al, Mn, Fe, Ni, Zn, Pb and U in both red and black than the white sorghum variety. The results show that sorghum whole grain flour made from grain with varying pericarp colours contains unique nutritional properties.

Low salt diet and treatment of hypertension: an old story.

A relatively low salt intake is nowadays considered one of the characteristics of a healthy diet in the Western world because several disorders appear to be unfavorably affected by excessive salt intake with the diet. The first notion about a relation between salt intake and blood pressure traces back to 2500 bc in an ancient Chinese medical textbook. This paper focuses on studies about salt and hypertension in the first half of the 20th century. The first papers in this field were published from the beginning of the century, but due to a modest scientific content were still not considered in the 1940s to provide sufficient evidence in favor of a salt restriction in hypertensive patients. A major practical contribution came from the Kempner rice diet, an effective antihypertensive dietary treatment which included a severe restriction of salt intake. After that, several studies in animals and humans showed that, with regard to the antihypertensive effect, the key element of the Kempner diet was the low salt content. By the first years of the 1950s, the evidence was already available that salt restriction is an effective antihypertensive treatment and that adherence to the treatment should be assessed by monitoring urinary electrolytes.

Effects of tellurite on growth of Saccharomyces cerevisiae.

The effects of potassium tellurite on growth and survival of rho(+) and rho(0) Saccharomyces cerevisiae strains were investigated. Both rho(+) and rho(0) strains grew on a fermentable carbon source with up to 1.2 mM K(2)TeO(3), while rho(+) yeast cells grown on a non-fermentable carbon source were inhibited at tellurite levels as low as 50 muM suggesting that this metalloid specifically inhibited mitochondrial functions. Growth of rho(+) yeast cells in the presence of increasing amount of tellurite resulted in dose-dependent blackening of the culture, a phenomenon not observed with rho(0) cultures. Transmission electron microscopy of S. cerevisiae rho(+) cells grown in the presence of tellurite showed that blackening was likely due to elemental tellurium (Te(0)) that formed large deposits along the cell wall and small precipitates in both the cytoplasm and mitochondria.

The microbial community of Vetiver root and its involvement into essential oil biogenesis.

Vetiver is the only grass cultivated worldwide for the root essential oil, which is a mixture of sesquiterpene alcohols and hydrocarbons, used extensively in perfumery and cosmetics. Light and transmission electron microscopy demonstrated the presence of bacteria in the cortical parenchymatous essential oil-producing cells and in the lysigen lacunae in close association with the essential oil. This finding and the evidence that axenic Vetiver produces in vitro only trace amounts of oil with a strikingly different composition compared with the oils from in vivo Vetiver plants stimulated the hypothesis of an involvement of these bacteria in the oil metabolism. We used culture-based and culture-independent approaches to analyse the microbial community of the Vetiver root. Results demonstrate a broad phylogenetic spectrum of bacteria, including alpha-, beta- and gamma-Proteobacteria, high-G+C-content Gram-positive bacteria, and microbes belonging to the Fibrobacteres/Acidobacteria group. We isolated root-associated bacteria and showed that most of them are able to grow by using oil sesquiterpenes as a carbon source and to metabolize them releasing into the medium a large number of compounds typically found in commercial Vetiver oils. Several bacteria were also able to induce gene expression of a Vetiver sesquiterpene synthase. These results support the intriguing hypothesis that bacteria may have a role in essential oil biosynthesis opening the possibility to use them to manoeuvre the Vetiver oil molecular structure.

Mitochondrial ribosomal proteins involved in tellurite resistance in yeast Saccharomyces cerevisiae.

A considerable body of evidence links together mitochondrial dysfunctions, toxic action of metalloid oxyanions, and system and neurodegenerative disorders. In this study we have used the model yeast Saccharomyces cerevisiae to investigate the genetic determinants associated with tellurite resistance/sensitivity. Nitrosoguanidine-induced K2TeO3-resistant mutants were isolated, and one of these mutants, named Sc57-Te5R, was characterized. Both random spore analysis and tetrad analysis and growth of heterozygous (TeS/Te5R) diploid from Sc57-Te5R mutant revealed that nuclear and recessive mutation(s) was responsible for the resistance. To get insight into the mechanisms responsible for K2TeO3-resistance, RNA microarray analyses were performed with K2TeO3-treated and untreated Sc57-Te5R cells. A total of 372 differentially expressed loci were identified corresponding to 6.37% of the S. cerevisiae transcriptome. Of these, 288 transcripts were up-regulated upon K2TeO3 treatment. About half of up-regulated transcripts were associated with the following molecular functions: oxidoreductase activity, structural constituent of cell wall, transporter activity. Comparative whole-genome sequencing allowed us to identify nucleotide variants distinguishing Sc57-Te5R from parental strain Sc57. We detected 15 CDS-inactivating mutations, and found that 3 of them affected genes coding mitochondrial ribosomal proteins (MRPL44 and NAM9) and mitochondrial ribosomal biogenesis (GEP3) pointing out to alteration of mitochondrial ribosome as main determinant of tellurite resistance.

Ty1 transposition induced by carcinogens in Saccharomyces cerevisiae yeast depends on mitochondrial function.

The transposition of the Ty mobile genetic element of Saccharomyces cerevisiae is induced by carcinogens. While the molecular background of spontaneous Ty1 transposition is well understood, the detailed mechanism of carcinogen induced Ty1 transposition is not clear. We found that mitochondrial functions participate in the Ty induced transposition induced by carcinogens. Contrary to the parental rho(+) cells rho(-) mutants (spontaneous or induced by ethidium bromide) do not increase the rate of Ty1 transposition upon treatment with carcinogens. Preliminary results strongly suggest that the absence of oxidative phosphorylation in rho(-) mutants is the reason for the inhibited Ty transposition. The lack of carcinogen induced Ty1 transposition in rho(-) cells is not specific for a particular carcinogen and represents a general feature of different carcinogenic substances inducing rho(-). It is concluded that carcinogen induced Ty1 transposition depends on the functional state of mitochondria and cannot take place in cells with compromised mitochondrial function (rho(-)).

Interaction between yeast mitochondrial and nuclear genomes: null alleles of RTG genes affect resistance to the alkaloid lycorine in rho0 petites of Saccharomyces cerevisiae.

Some nuclear genes in Saccharomyces cerevisiae (S. cerevisiae) respond to signals from the mitochondria in a process called by Butow (Cell Death Differ. 9 (2002) 1043-1045) retrograde regulation. Expression of these genes is activated in cells lacking mitochondrial function by involvement of RTG1, RTG2 and RTG3 genes whose protein products bind to "R-boxes" in the promoter region; RTG2p is a cytoplasmic protein. Since S. cerevisiae rho0 strains, lacking the entire mitochondrial genome, are resistant to lycorine, an alkaloid extracted from Amaryllis plants, it could be hypothesized that in rho0 cells the dysfunctional mitochondrial status stimulates overexpression of nuclear genes very likely involved in both nuclear and mitochondrial DNA replication. In this report we show that the resistance of rho0 cells to lycorine is affected by the deletion of RTG genes.

Tellurium as a valuable tool for studying the prokaryotic origins of mitochondria.

Mitochondria are eukaryotic organelles which contain the own genetic material and evolved from free-living Eubacteria, namely hydrogen-producing Alphaproteobacteria. Since 1965, biologists provided, by research at molecular level, evidence for the prokaryotic origins of mitochondria. However, determining the precise origins of mitochondria is challenging due to inherent difficulties in phylogenetically reconstructing ancient evolutionary events. The use of new tools to evidence the prokaryotic origin of mitochondria could be useful to gain an insight into the bacterial endosymbiotic event that resulted in the permanent acquisition of bacteria, from the ancestral cell, that through time were transformed into mitochondria. Electron microscopy has shown that both proteobacterial and yeast cells during their growth in the presence of increasing amount of tellurite resulted in dose-dependent blackening of the culture due to elemental tellurium (Te(0)) that formed large deposits either along the proteobacterial membrane or along the yeast cell wall and mitochondria. Since the mitochondrial inner membrane composition is similar to that of proteobacterial membrane, in the present work we evidenced the black tellurium deposits on both, cell wall and mitochondria of ρ(+) and respiratory deficient ρ(-) mutants of yeast. A possible role of tellurite in studying the evolutionary origins of mitochondria will be discussed.

Isolation and characterisation of nuclear mutants with enhanced mitochondrial mutability in the fission yeast Schizosaccharomyces pombe.

In this paper we report the isolation and preliminary characterisation of nuclear mutants with increased mitochondrial mutability in fission yeast. Screening of about 2000 clones after nitrosoguanidine mutagenesis led to the isolation of ten mutator mutants. For one of them (mut-1) we show that the mutation is chromosomally encoded. The activity of the mutator is restricted to the mitochondrial genome, since it increases the mutation rate to mitochondrially encoded drug resistance considerably, whereas the mutability of nuclear genes is not altered.

[A case of encapsulating peritoneal sclerosis after fifteen years of peritoneal dialysis with a favorable outcome]. / Un caso di peritonite sclerosante incapsulante con esito favorevole dopo 15 anni di dialisi peritoneale.

Encapsulating peritoneal sclerosis (EPS) represents a critical complication of peritoneal dialysis (PD). EPS is characterized by abdominal discomfort, often leading to fatal outcomes with limited pharmaceutical and surgical options. Herein is described a case of EPS with a favorable outcome in an African male treated with PD for 15 years. Repeated courses of prednisone and tamoxifen significantly attenuated the abdominal symptoms and the peritoneal membrane thickening. This case suggests a time dependent effect of medical treatment encouraging clinical efforts to maintain a mild immunosuppressant regimen and tamoxifen in the presence of EPS also on the long run. Future and ad hoc studies should test this hypothesis.

Sorghum, a healthy and gluten-free food for celiac patients as demonstrated by genome, biochemical, and immunochemical analyses.

Wheat (Triticum spp. L.), rye (Secale cereal L.), and barley (Hordeum vulgare L.) seeds contain peptides toxic to celiac patients. Maize (Zea mays L.) and rice (Oryza sativa L.) are distant relatives of wheat as well as sorghum (Sorghum bicolor (L.) Moench) and are known to be safe for celiacs. Both immunochemical studies and in vitro and in vivo challenge of wheat-free sorghum food products support this conclusion, although molecular evidence is missing. The goal of the present study was to provide biochemical and genetic evidence that sorghum is safe for celiac patients. In silico analysis of the recently published sorghum genome predicts that sorghum does not contain peptides that are toxic for celiac patients. Aqueous/alcohol-soluble prolamins (kafirins) from different sorghum varieties, including pure lines and hybrids, were evaluated by SDS-PAGE and HPLC analyses as well as an established enzyme-linked immunosorbent assay (ELISA) based on the R5 antibody. These analyses provide molecular evidence for the absence of toxic gliadin-like peptides in sorghum, confirming that sorghum can be definitively considered safe for consumption by people with celiac disease.

Celiac disease: in vitro and in vivo safety and palatability of wheat-free sorghum food products.

BACKGROUND & AIMS: Celiac disease is a condition in which genetically predisposed people have an autoimmune reaction to gluten proteins found in all wheat types and closely related cereals such as barley and rye. This reaction causes the formation of autoantibodies and the destruction of the villi in the small intestine, which results in malabsorption of nutrientsand other gluten-induced autoimmune diseases. Sorghum is a cereal grain with potential to be developed into an important crop for human food products. The flour produced from white sorghum hybrids is light in color and has a bland, neutral taste that does not impart unusual colors or flavors to food products. These attributes make it desirable for use in wheat-free food products. While sorghum is considered as a safe food for celiac patients, primarily due to its relationship to maize, no direct testing has been conducted on its safety for gluten intolerance. Therefore studies are needed to assess its safety and tolerability in celiac patients. Thus the aim of the present study was to assess safety and tolerability of sorghum flour products in adult celiac disease patients, utilizing an in vitro and in vivo challenge. RESULTS: Sorghum protein digests did not elicit any morphometric or immunomediated alteration of duodenal explants from celiac patients. Patients fed daily for 5 days with sorghum-derived food product did not experience gastrointestinal or non-gastrointestinal symptoms and the level of anti-transglutaminase antibodies was unmodified at the end of the 5-days challenge. CONCLUSIONS: Sorghum-derived products did not show toxicity for celiac patients in both in vitro and in vivo challenge. Therefore sorghum can be considered safe for people with celiac disease.

Nitrite metabolism in Debaryomyces hansenii TOB-Y7, a yeast strain involved in tobacco fermentation.

The Italian cigar manufacturing process includes a fermentation step that leads to accumulation of nitrite and tobacco-specific nitrosamines (TSNA), undesirable by-products due to their negative impact on health. In this study, growth and biochemical properties of Debaryomyces hansenii TOB-Y7, a yeast strain that predominates during the early phase of fermentation, have been investigated. With respect to other D. hansenii collection strains (Y7426, J26, and CBS 1796), TOB-Y7 was characterized by the ability to tolerate very high nitrite levels and to utilize nitrite, but not nitrate, as a sole nitrogen source in a chemically defined medium, a property that was enhanced in microaerophilic environment. The ability to assimilate nitrite was associated to the presence of YNI1, the gene encoding the assimilatory NAD(P)H:nitrite reductase (NiR), absent in Y7426, J26, and CBS 1796 by Southern blot data. YNI1 from TOB-Y7 was entirely sequenced, and its expression was analyzed in different media by Northern blot and reverse transcriptase polymerase chain reaction. The evidence that, in D. hansenii TOB-Y7, YNI1 was transcriptional active also in the presence of high ammonia concentration typical of tobacco fermentation, stimulated the development of an improved process that, on a laboratory scale, was proved to be effective in minimizing nitrite and TSNA accumulation.

Hyper-expression of small nucleolar RNAs (snoRNAs) in female inflorescences of hazelnut (Corylus avellana L.) supports rRNA aggregation in vitro.

Under certain in vitro (salt and temperature) conditions rRNA aggregation occurs in female inflorescences but not in leaves or pollen RNA preparations from hazelnut (Corylus avellana L.), a species of economic interest. This paper describes experiments addressing an explanation of this phenomenon. The experiments demonstrate that: (i) trans-acting factors induce rRNA aggregate formation in female inflorescences RNA preparations; (ii) these factors support aggregation also of heterologous rRNA; (iii) aggregation is a function of temperature pre-treatment of rRNA and not of source 18S rRNA; (iv) the factors inducing rRNA aggregates are sensitive to RNase; (v) antisense small nucleolar RNAs (snoRNAs) participate in rRNA aggregate formation. snoRNAs are involved in pre-rRNA spacer cleavages, and are required for the two most common types of rRNA modifications: 2'-O-ribose methylation and pseudouridylation. Even though it is questionable whether rRNA aggregation really happens in female inflorescence in vivo, the phenomenon observed in vitro may reflect the abundance of snoRNAs in these reproductive structures. In fact the level of accumulation of three tested snoRNAs, R1, U14 and U3, is much higher in female inflorescence than in leaves or pollen of hazelnut. This finding opens the possibility of studying the role of snoRNAs in tissue development in plants.

Phenotypes of a naturally defective recB allele in Neisseria meningitidis clinical isolates.

Neisseria meningitidis strains belonging to the hypervirulent lineage ET-37 and several unrelated strains are extremely UV sensitive. The phenotype is consequent to the presence of a nonfunctional recB(ET-37) allele carrying multiple missense mutations. Phenotypic analysis has been performed with congenic meningococcal strains harboring either the wild-type recB allele or the recB(ET-37) allele. Congenic recB(ET-37) meningococci, in addition to being sensitive to UV, were defective both in repair of DNA lesions induced by UV treatment and, partially, in recombination-mediated transformation. Consistently, the wild-type, but not the recB(ET-37), allele was able to complement the Escherichia coli recB21 mutation to UV resistance and proficiency in recombination. recB(ET-37) meningococci did not exhibit higher frequencies of spontaneous mutation to rifampin resistance than recB-proficient strains. However, mutation rates were enhanced following UV treatment, a phenomenon not observed in the recB-proficient counterpart. Interestingly, the results of PCR-based assays demonstrated that the presence of the recB(ET-37) allele considerably increased the frequency of recombination at the pilin loci. The main conclusion that can be drawn is that the presence of the defective recB(ET-37) allele in N. meningitidis isolates causes an increase in genetic diversity, due to an ineffective RecBCD-dependent DNA repair and recombination pathway, and an increase in pilin antigenic variation.