Potentiation of sympathetic neurotransmission in bovine isolated irides by isoprostanes

Isoprostanes (IsoP) are formed by free radical catalyzed peroxidation of arachidonic acid independent of the cyclooxygenase enzyme. In the present study, we examined the effect of IsoP on norepinephrine (NE) release from the bovine isolated iris. Furthermore, we studied the role of IsoP's in hydrogen peroxide (H₂O₂)-induced enhancement of NE release from this tissue. Isolated bovine irides were prepared for studies of [³H]NE release using the superfusion method. Release of [³H]NE was induced via electrical field stimulation. Both 8-iso-prostaglandin E₂ (E₂-IsoP) and 8-iso-prostaglandin F_2α (F₂-IsoP) produced a concentration-related enhancement of field-stimulated [³H]NE release from isolated bovine irides, an effect that was mimicked by the thromboxane (Tx) receptor agonist, U46619 and by H₂O₂. The Tx-receptor antagonist, SQ 29548 inhibited responses to E₂-IsoP (10μM) with an IC₅₀ of 370±50 nM. SQ 29548 (10μM) also blocked the enhancement of electrically-evoked [³H]NE release induced by U46619 (10μM) but not that caused by H₂O₂ (300μM). The Tx synthetase inhibitor, carboxyheptylimidazole (10μM) prevented the stimulatory effect of E₂-IsoP on evoked [³H]NE release without affecting responses induced by H₂O₂. We conclude that IsoP's can enhance sympathetic neurotransmission in the bovine isolated iris, an effect that can be blocked by a Tx-receptor antagonist. Furthermore, endogenously produced Tx's mediate the stimulatory effect of IsoP's on NE release. However, endogenously generated IsoP's or Tx's are not involved in H₂O₂-induced potentiation of sympathetic neurotransmission.     

Unique Dental Morphology of Homo floresiensis and Its Evolutionary Implications

Homo floresiensis is an extinct, diminutive hominin species discovered in the Late Pleistocene deposits of Liang Bua cave, Flores, eastern Indonesia. The nature and evolutionary origins of H. floresiensis’ unique physical characters have been intensively debated. Based on extensive comparisons using linear metric analyses, crown contour analyses, and other trait-by-trait morphological comparisons, we report here that the dental remains from multiple individuals indicate that H. floresiensis had primitive canine-premolar and advanced molar morphologies, a combination of dental traits unknown in any other hominin species. The primitive aspects are comparable to H. erectus from the Early Pleistocene, whereas some of the molar morphologies are more progressive even compared to those of modern humans. This evidence contradicts the earlier claim of an entirely modern human-like dental morphology of H. floresiensis, while at the same time does not support the hypothesis that H. floresiensis originated from a much older H. habilis or Australopithecus-like small-brained hominin species currently unknown in the Asian fossil record. These results are however consistent with the alternative hypothesis that H. floresiensis derived from an earlier Asian Homo erectus population and experienced substantial body and brain size dwarfism in an isolated insular setting. The dentition of H. floresiensis is not a simple, scaled-down version of earlier hominins.     

Characterization and Modulation of Glucose Uptake in a Human Blood–Brain Barrier Model

The blood–brain barrier (BBB) plays a key role in limiting and regulating glucose access to glial and neuronal cells. In this work glucose uptake on a human BBB cell model (the hCMEC/D3 cell line) was characterized. The influence of some hormones and diet components on glucose uptake was also studied. ³H-2-deoxy-d-glucose ([³H]-DG) uptake for hCMEC/D3 cells was evaluated in the presence or absence of tested compounds. [³H]-DG uptake was sodium- and energy-independent. [³H]-DG uptake was regulated by Ca²⁺ and calmodulin but not by MAPK kinase pathways. PKC, PKA and protein tyrosine kinase also seem to be involved in glucose uptake modulation. Progesterone and estrone were found to decrease ³H-DG uptake. Catechin and epicatechin did not have any effect, but their methylated metabolites increased [³H]-DG uptake. Quercetin and myricetin decreased [³H]-DG uptake, and glucuronic acid-conjugated quercetin did not have any effect. These cells expressed GLUT1, GLUT3 and SGLT1 mRNA.     

Three-dimensional Nuclear Telomere Organization in Multiple Myeloma

Multiple myeloma (MM) is preceded by monoclonal gammopathy of undetermined significance (MGUS). Up to date, it is difficult to predict an individual's time to disease progression and the treatment response. To examine whether the nuclear telomeric architecture will unravel some of these questions, we carried out. Three-dimensional (3D) telomere analysis on samples from patients diagnosed with MGUS and MM, as well as from patients who went into relapse. Telomere signal intensity, number of telomere aggregates, nuclear volume, and the overall nuclear telomere distribution (a/c ratio) were analyzed. The telomeric profiles allowed for the differentiation of the disease stages. The telomeric profiles of myeloma cells obtained from blood and bone marrow aspirates were identical. Based on this study, we discuss the use of 3D telomere profiling as a potential future tool for risk stratification and personalized treatment decisions.     

Silicon-Induced changes in antifungal phenolic acids, flavonoids, and key phenylpropanoid pathway genes during the interaction between miniature roses and the biotrophic pathogen Podosphaera pannosa

Application of 3.6 mm silicon (Si+) to the rose (Rosa hybrida) cultivar Smart increased the concentration of antimicrobial phenolic acids and flavonoids in response to infection by rose powdery mildew (Podosphaera pannosa). Simultaneously, the expression of genes coding for key enzymes in the phenylpropanoid pathway (phenylalanine ammonia lyase, cinnamyl alcohol dehydrogenase, and chalcone synthase) was up-regulated. The increase in phenolic compounds correlated with a 46% reduction in disease severity compared with inoculated leaves without Si application (Si-). Furthermore, Si application without pathogen inoculation induced gene expression and primed the accumulation of several phenolics compared with the uninoculated Si- control. Chlorogenic acid was the phenolic acid detected in the highest concentration, with an increase of more than 80% in Si+ inoculated compared with Si- uninoculated plants. Among the quantified flavonoids, rutin and quercitrin were detected in the highest concentrations, and the rutin concentration increased more than 20-fold in Si+ inoculated compared with Si- uninoculated plants. Both rutin and chlorogenic acid had antimicrobial effects on P. pannosa, evidenced by reduced conidial germination and appressorium formation of the pathogen, both after spray application and infiltration into leaves. The application of rutin and chlorogenic acid reduced powdery mildew severity by 40% to 50%, and observation of an effect after leaf infiltration indicated that these two phenolics can be transported to the epidermal surface. In conclusion, we provide evidence that Si plays an active role in disease reduction in rose by inducing the production of antifungal phenolic metabolites as a response to powdery mildew infection.     

Biogenic amine production by lactic acid bacteria isolated from cider

AIMS: To study the occurrence of histidine, tyrosine and ornithine decarboxylase activity in lactic acid bacteria (LAB) isolated from natural ciders and to examine their potential to produce detrimental levels of biogenic amines. METHODS AND RESULTS: The presence of biogenic amines in a decarboxylase synthetic broth and in cider was determined by reversed-phase high-performance liquid chromatography (RP-HPLC). Among the 54 LAB strains tested, six (five lactobacilli and one oenococci) were biogenic amine producers in both media. Histamine and tyramine were the amines formed by the LAB strains investigated. Lactobacillus diolivorans were the most intensive histamine producers. This species together with Lactobacillus collinoides and Oenococcus oeni also seemed to produce tyramine. No ability to form histamine, tyramine or putrescine by Pediococus parvulus was observed, although it is a known biogenic amine producer in wines and beers. CONCLUSIONS: This study demonstrated that LAB microbiota growing in ciders had the ability to produce biogenic amines, particularly histamine and tyramine, and suggests that this capability might be strain-dependent rather than being related to a particular bacterial species. SIGNIFICANCE AND IMPACT OF THE STUDY: Production of biogenic amines by food micro-organisms has continued to be the focus of intensive study because of their potential toxicity. The main goal was to identify the microbial species capable of producing these compounds in order to control their presence and metabolic activity in foods.     

Polyphenols restore endothelial function in DOCA-salt hypertension: role of endothelin-1 and NADPH oxidase

Red wine polyphenols (RWPs) have been reported to exert beneficial effects in preventing cardiovascular diseases, such as hypertension. We studied the effects of chronic treatment with RWPs and apocynin, an inhibitor of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, on blood pressure, endothelial function, and oxidative status in deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Rats were administered RWPs (40 mg/kg) or apocynin (33 microg/kg) daily by gavage for 5 weeks. Plasma catechin levels were detected only after RWP treatment. RWPs and apocynin prevented both the increase in systolic blood pressure and the proteinuria induced by DOCA-salt. Plasma malonyldialdehyde levels, urinary iso-prostaglandin F(2alpha) excretion, aortic superoxide production, and aortic NADPH oxidase activity were found to be increased in animals of the DOCA group. RWP and apocynin treatments reduced these parameters in DOCA-salt rats, having no effect on control rats. However, only RWPs reduced the increase in plasma endothelin-1 (ET-1) levels and aortic p22(phox) gene overexpression found in DOCA-salt animals. RWPs and apocynin also improved the blunted endothelium-dependent relaxation response to acetylcholine in noradrenaline-precontracted aortic rings. All these results suggest that chronic treatment with RWPs prevents hypertension and vascular dysfunction. RWPs prevent vascular oxidative stress by inhibiting NADPH oxidase activity and/or by reducing ET-1 release.     

Estrogen receptor genes polymorphisms determine serum lipid profile in healthy postmenopausal women treated with calcium,vitamin D,and genistein

Cardiovascular risk increases in women after menopause. Unfavorable lipid-lipoprotein changes due to a lack of estrogens may have an important role in this context. Estrogen actions are mainly mediated by their binding to two estrogen receptors (ERs) whose signaling may be conditioned by different factors. Calcium, vitamin D, and genistein, among others, cause a beneficial effect on serum lipid profile by its modulation. Some genetic factors can also determine this signal. We determined the possible additive effect of genistein on calcium and vitamin D supplementation regarding serum lipid profile changes and whether ER polymorphisms may mediate in this effect. We performed a prospective, double blind study in which women were randomized in two groups: one group received calcium and vitamin D and the other group received calcium, vitamin D and genistein. Subsequently, we studied rs9340799, rs928554, and rs4986938 ER polymorphisms in both groups. Our results showed that being a carrier of the variant allele G of rs928554 polymorphism was associated with a greater decrease in triglyceride levels and that the homozygous AA genotype of rs9340799 polymorphism was associated with a greater decrease in total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels after calcium, vitamin D, and genistein supplementation. This is the first report showing an association between polymorphisms in ER genes and an improvement of the serum lipid profile after taking calcium, vitamin D, and genistein supplementation in postmenopausal women. It reinforces the hypothesis that genetic factors are crucial in ER signalling.     

Valencene oxidase CYP706M1 from Alaska cedar (Callitropsis nootkatensis)

(+)-Nootkatone is a natural sesquiterpene ketone used in grapefruit and citrus flavour compositions. It occurs in small amounts in grapefruit and is a major component of Alaska cedar (Callitropsis nootkatensis) heartwood essential oil. Upon co-expression of candidate cytochrome P450 enzymes from Alaska cedar in yeast with a valencene synthase, a C. nootkatensis valencene oxidase (CnVO) was identified to produce trans-nootkatol and (+)-nootkatone. Formation of (+)-nootkatone was detected at 144 ± 10 μg/L yeast culture. CnVO belongs to a new subfamily of the CYP706 family of cytochrome P450 oxidases.     

Riboflavin-overproducing strains of Lactobacillus fermentum for riboflavin-enriched bread

Lactobacillus fermentum isolated from sourdough was able to produce riboflavin. Spontaneous roseoflavin-resistant mutants were obtained by exposing the wild strain (named L. fermentum PBCC11) to increasing concentrations of roseoflavin. Fifteen spontaneous roseoflavin-resistant mutants were isolated, and the level of vitamin B₂ was quantified by HPLC. Seven mutant strains produced concentrations of vitamin B₂ higher than 1 mg L^?1. Interestingly, three mutants were unable to overproduce riboflavin even though they were able to withstand the selective pressure of roseoflavin. Alignment of the rib leader region of PBCC11 and its derivatives showed only point mutations at two neighboring locations of the RFN element. In particular, the highest riboflavin-producing isolates possess an A to G mutation at position 240, while the lowest riboflavin producer carries a T to A substitution at position 236. No mutations were detected in the derivative strains that did not have an overproducing phenotype. The best riboflavin overproducing strain, named L. fermentum PBCC11.5, and its parental strain were used to fortify bread. The effect of two different periods of fermentation on the riboflavin level was compared. Bread produced using the coinoculum yeast and L. fermentum PBCC11.5 led to an approximately twofold increase of final vitamin B₂ content.