Protective effects of melatonin on changes occurring in the experimental autoimmune encephalomyelitis model of multiple sclerosis.

BACKGROUND: Melatonin has been related to the pathophysiology of multiple sclerosis (MS), and its anti-inflammatory and immunomodulatory properties have been proved in numerous neurodegenerative diseases. This study aimed to find out whether a melatonin supplement in MS is able to act as a benefit to its clinical status, i.e. oxidative stress, inflammation and indirect biomarkers of bacterial dysbiosis, lipopolysaccharide (LPS) and LPS-binding protein (LBP), verifying its therapeutic potential and its possible clinical use in patients with MS. METHODS: The animal MS model, experimental autoimmune encephalomyelitis (EAE), was employed whereby 25 male Dark Agouti rats (5 animals per group) were divided into: a control group (not manipulated); a control+vehicle group; a control+melatonin group; an EAE group; an EAE+melatonin group. Melatonin was administered daily for 51 days, at a dose of 1 mg/kg body weight/i.p., once a day, five days a week. RESULTS: The results from the administration of melatonin demonstrated an improvement in clinical status, a diminution in oxidative stress and inflammation, as well as in bacterial dysbiosis. CONCLUSION: Melatonin could play an effective role against MS, either alone or as a therapy combined with traditional agents.

Reacción local intensa en zonas de inyección de mesoterapia lipolítica / Intense Local Reaction at the Sites of Injection of Lipolytic Mesotherapy

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The Potato Cryobank at The International Potato Center (Cip): A Model for Long Term Conservation of Clonal Plant Genetic Resources Collections of the Future.

BACKGROUND: Cryobanks are a secure, efficient and low cost method for the long-term conservation of plant genetic resources for theoretically centuries or millennia with minimal maintenance. OBJECTIVE: The present manuscript describes CIP's modified protocol for potato cryopreservation, its large-scale application, and the establishment of quality and operational standards, which included a viability reassessment of material entering the cryobank. MATERIALS AND METHODS: In 2013, CIP established stricter quality and operational standards under which 1,028 potato accessions were cryopreserved with an improved PVS2-droplet protocol. In 2014 the viability of 114 accessions cryopreserved in 2013 accessions were reassessed. RESULTS: The average recovery rate (full plant recovery after LN exposure) of 1028 cryopreserved Solanum species ranged from 34 to 59%, and 70% of the processed accessions showed a minimum recovery rate of ≥20% and were considered as successfully cryopreserved. CONCLUSION: CIP has established a new high quality management system for cryobanking. Periodic viability reassessment, strict and clear recovery criteria and the monitoring of the percent of successful accessions meeting the criteria as well as contamination rates are metrics that need to be considered in cryobanks.

Mujer de 25 años con lesión seudotumoral talámica posvacunal / A 25 years-old woman with a postvaccine thalamic pseudotumoral lesion

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MRNA and miRNA expression patterns associated to pathways linked to metal mixture health effects.

Metals are a threat to human health by increasing disease risk. Experimental data have linked altered miRNA expression with exposure to some metals. MiRNAs comprise a large family of non-coding single-stranded molecules that primarily function to negatively regulate gene expression post-transcriptionally. Although several human populations are exposed to low concentrations of As, Cd and Pb as a mixture, most toxicology research focuses on the individual effects that these metals exert. Thus, this study aims to evaluate global miRNA and mRNA expression changes induced by a metal mixture containing NaAsO2, CdCl2, Pb(C2H3O2)2·3H2O and to predict possible metal-associated disease development under these conditions. Our results show that this metal mixture results in a miRNA expression profile that may be responsible for the mRNA expression changes observed under experimental conditions in which coding proteins are involved in cellular processes, including cell death, growth and proliferation related to the metal-associated inflammatory response and cancer.

Creencias y actitudes hacia la medicina tradicional Mexicana en las poblaciones de Zacualtipán y Pachuca, Hidalgo / Beliefs and attitudes towards traditional Mexican medicine in the towns of Zacualtipán and Pachuca, Hidalgo

La medicina tradicional ha resultado ser una práctica médica importante para la calidad de vida de las personas. No obstante su estudio desde la psicología social y cultural ha visto pocos frutos. A partir del presente ensayo se pretende mostrar el panorama general de la salud, la medicina y la medicina tradicional como una aproximación a tal estudio, de modo que se destaque la relevancia de este estudio por sus consecuencias en la salud, atendiendo a una aproximación sobre la conducta de las personas dirigidas a este tipo de prácticas médicas y el por qué, a pesar de tener al alcance los servicios de salud oficiales, acuden a este tipo de prácticas médicas.

Effects of a mixture of fatty acids from sugar cane (Saccharum officinarum L.) wax oil in two models of inflammation: zymosan-induced arthritis and mice tail test of psoriasis.

A mixture of fatty acids obtained from sugar cane (Saccharum officinarum L.) wax oil (FAM), in which the main constituents are palmitic, oleic, linoleic, and linolenic acids, was evaluated in two models of inflammation: zymosan-induced arthritis and in the tail test for psoriasis, both on mice. In the first model, FAM significantly reduced zymozan-induced increase of beta glucuronidase (DE(50) 90+/-7 mg/kg). Histopathological studies showed inhibition in cellular infiltration and reduction of synovial hyperplasia and synovitis, whereas in the second test, histopathological and ultrastructural studies showed that topical application of FAM induced orthokeratosis with the presence of keratohyalin granules in the previously parakeratotic adult mouse tail, and without effects on epidermal thickness. The ED(50) of FAM in this model was 155+/-10 mg. The results of our studies showed that topical application of FAM exerts an important anti-inflammatory activity in both tests without evidence of irritant effects. The anti-inflamatory effects exerted by FAM may be due to its inhibitory effects on arachidonic acid metabolism. To our knowledge, this is the first report on the anti-inflammatory effect of sugar cane by-products in experimental models of arthritis and psoriasis.

Further studies on a mixture of fatty acids from sugar cane (Saccharum officinarum) wax oil in animal models of hypersensitivity.

A mixture of fatty acids obtained from sugar cane wax oil, the main components of which are palmitic, oleic, linoleic and linolenic acids, was evaluated topically in two experimental models of hypersensitivity: the ear swelling response to ovalbumin in sensitized mice (ED50 edema: 0.63 +/- 0.06 mg/ear, ED50 myeloperoxidase: 0.56 +/- 0.04 mg/ear, ED50 degranulated cells: 0.70 +/- 0,08 mg/ear) and oxazolone-induced contact hypersensitivity in mice (ED50 edema: 1.63 +/- 0.26 mg/ear, ED50 myeloperoxidase: 1.50 +/- 0.28 mg/ear, ED50 degranulated cells: 1.69 +/- 0.08 mg/ear). Also, the effect of this mixture was studied on the chemotaxis induced by fmlp (ED50: 25 +/- 3 microg/mL). The mixture showed anti-inflammatory activity in both in vivo models of allergy and in the chemotaxis test. Therefore, these results provide evidence about the potential usefulness of the mixture of fatty acids from sugar cane wax oil in cutaneous inflammatory and allergic disorders.

Anti-inflammatory and analgesic effects of a mixture of fatty acids isolated and purified from sugar cane wax oil.

The anti-inflammatory and analgesic effects of FAM, a defined mixture of fatty acids isolated from sugar cane (Saccharum officinarum L.), was evaluated. Oral administration of this mixture showed anti-inflammatory activity in the cotton pellet granuloma assay and in the carrageenin-induced pleurisy test, both in rats, as well as in the peritoneal capillary permeability test in mice. In addition, FAM showed analgesic properties in the hot-plate model and in the acetic acid-induced writhings test, both in mice. In conclusion, these results provide evidence on the potential usefulness of the mixture of fatty acids from sugar cane wax oil in inflammatory disorders.

Bone disease in patients with long-term renal transplantation and normal renal function.

Renal osteodystrophy may persist during the early years after renal transplantation. However, information on bone status after a successful long-term renal transplantation is limited. We examined biochemical parameters, bone mineral density (BMD), and bone histomorphometry in 25 asymptomatic men with normal renal function after 7.5 +/- 5.7 years of a renal transplantation. Serum calcium, phosphorus, alkaline phosphatase, and 1,25(OH)(2)D(3) levels and urinary calcium level and cyclic andenosine monophosphate excretion were within normal range in all patients. Serum intact parathyroid hormone (PTH) level was elevated in 11 subjects (133.6 +/- 78 pg/mL) and normal in the other 14 subjects (47.9 +/- 13.6 pg/mL). Mean BMD at the lumbar spine and femoral neck was low in the entire group. However, it progressively increased as time after transplantation increased, approaching normal values after 10 years. Bone histomorphometric analysis showed bone resorption, osteoid volume, and osteoid surface greater than normal range in the majority of patients. Bone formation rate and mineralization surface were low, and mineralization time was delayed in most patients. These lesions were more severe in patients after 3 to 4 years of transplantation but improved with time and approached normal values after a period of 10 years. PTH values did not correlate with bone histological characteristics or BMD. These results show that the bone alterations observed after long-term renal transplantation consist of a mixed bone disease in which features of high bone turnover coexist with altered bone formation and delayed mineralization. These findings may result from the combined effect of preexisting bone disease and immunosuppressive therapy.

Alzheimer's beta-amyloid, human islet amylin, and prion protein fragment evoke intracellular free calcium elevations by a common mechanism in a hypothalamic GnRH neuronal cell line.

A growing number of reports suggest that elevated levels of extracellular Alzheimer's beta-amyloid protein alter the homeostasis of free [Ca(2+)](i) in different cell types of the mammalian brain. In line with these results, we have previously shown that AbetaP[1-40] forms cation-selective channels (Ca(2+) included) across artificial planar bilayers formed from acidic phospholipids and across excised membrane patches from immortalized hypothalamic GnRH neurons (GT1-7 cells), suggesting that the nonregulated Ca(2+)-influx through these spontaneously formed "amyloid channels" may provide a mechanism to explain its toxicity (1). We have now found and report here that the application of AbetaP[1-40] to GT1-7 neurons consistently elevates [Ca(2+)](i) levels. We also found that human islet amylin and the prion protein fragment (PrP106-126), peptides that acquire beta-pleated sheet conformation in water solutions and have been reported to form ion channels across planar bilayer membranes, also increase cytosolic free calcium in GT1-7 neurons. Searching for protective agents, we found that soluble cholesterol, known to decrease the fluidity of the cell membrane, inhibits AbetaP[1-40]-evoked [Ca(2+)](i) rise. These results suggest that unregulated Ca(2+) entry across amyloid channels may be a common mechanism causing cell death, not only in diseases of the third age, including Alzheimer's disease and type 2 diabetes mellitus, but also in prion-induced diseases.

Are metals dietary carcinogens?

Humans have been in contact with metals almost since the beginning of our existence. In fact, one cannot even think on human evolution without considering the great role played by metals in mankind's development. Metals are common moieties of molecules involved in a wide variety of biological processes, and hence are found in virtually all living organisms. Some metals are essential for human nutrition; others are found as contaminants in foodstuffs. One feature of the normal human diet which is frequently found is the simultaneous presence of both essential and toxic metals. Other factors important in the risk-evaluation analysis of metals are their pharmacokinetics, interactions among them and with other major components of the diet, and, especially, the great differences in the dietary habits of different populations and in the regional distribution of metals. In attempting to understand the role which dietary metals could play in human carcinogenesis, we found that the many factors involved and the lack of specific information made it difficult to reach firm conclusions on the hazards of dietary metals. We hope that this paper will raise the interest of genetic toxicologists in the subject and will consequently facilitate a risk analysis of the carcinogenic potential of dietary metals.

Alzheimer's disease amyloid beta-protein forms Zn(2+)-sensitive, cation-selective channels across excised membrane patches from hypothalamic neurons.

We have previously shown that the 40-residue peptide termed amyloid beta-protein (A beta P[1-40]) in solution forms cation-selective channels across artificial phospholipid bilayer membranes. To determine whether A beta P[1-40] also forms channels across natural membranes, we used electrically silent excised membrane patches from a cell line derived from hypothalamic gonadotrophin-releasing hormone GnRH neurons. We found that exposing either the internal or the external side of excised membrane patches to A beta P[1-40] leads to the spontaneous formation of cation-selective channels. With Cs+ as the main cation in both the external as well as the internal saline, the amplitude of the A beta P[1-40] channel currents was found to follow the Cs+ gradient and to exhibit spontaneous conductance changes over a wide range (50-500 pS). We also found that free zinc (Zn2+), reported to bind to amyloid beta-protein in solution, can block the flow of Cs+ through the A beta P[1-40] channel. Because the Zn2+ chelator o-phenanthroline can reverse this blockade, we conclude that the underlying mechanism involves a direct interaction between the transition element Zn2+ and sites in the A beta P[1-40] channel pore. These properties of the A beta P[1-40] channel are rather similar to those observed in the artificial bilayer system. We also show here, by immunocytochemical confocal microscopy, that amyloid beta-protein molecules form deposits closely associated with the plasma membrane of a substantial fraction of the GnRH neurons. Taken together, these results suggest that the interactions between amyloid beta-protein and neuronal membranes also occur in vivo, lending further support to the idea that A beta P[1-40] channel formation might be a mechanism of amyloid beta-protein neurotoxicity.

Effects of Cuban red propolis on galactosamine-induced hepatitis in rats.

Using transmission electron microscopy and biochemical analysis, the effect of cuban red propolis against hepatitis induced by 1,000 mg kg-1 of galactosamine in rats was studied. An ethanolic extract of propolis was prepared and it was given to rats at doses of 10, 50 and 100 mg kg-1, 30 min before the hepatotoxin. Propolis extract prevented hepatocytes alterations induced by galactosamine. It was mainly seen in rough endoplasmic reticulum, Golgi complex, nucleus and plasma membrane of hepatocytes. Propolis extract induced reversion of the increased activity of alanine aminotransferase and malondialdehyde concentration in the serum of rats treated with galactosamine. The probable role of antioxidant activity of propolis in the prevention of hepatitis is discussed in this paper.

Protective effects of Propolis extract on allyl alcohol-induced liver injury in mice.

Potential protective effects of ethanolic extract of Cuban red propolis against toxicity induced by allyl alcohol in mice was investigated. Propolis at doses of 25, 50 and 100 mg/i.p. significantly decreased the activity of alanine amino transferase (EC 2.6.1.2) in serum and the levels of mal-ondialdehyde in mouse liver after induction with a dose of 64 mg/kg of allyl alcohol. However, propolis did not increase the concentration of reduced glutathione in mouse liver which is depleted by allyl alcohol. Propolis also reduced liver damage induced by allyl alcohol in mice. This effect was observed by electron microscopy. The hepatoprotective effects of propolis were dose-dependent and they were produced when propolis was administered 30 min before allyl alcohol administration. It is indicated that the ethanolic extract of red propolis exerts potential hepatoprotective effects in this experimental model which is probably caused by antioxidative properties (e.g. scavenging action against oxygen radicals) of this extract.

Genotoxic effects of Karwinskia humboldtiana toxin T-514 in peripheral blood lymphocytes.

Toxicity by Karwinskia humboldtiana, a Rhamnaceae plant, has been assessed in a number of studies. Four dimmeric anthracenones, named T-496, T-514, T-516 and T-544 for their molecular weight, have been isolated from this plant. T-514, in particular, has been shown to be toxic to liver and lung as well as to tumoral cell lines, preferentially to those from liver tumors. For this reason it has been suggested that the toxin could be used as an antineoplastic agent. The present study was performed to characterize the biological activity of T-514 as a potential cytostatic and genotoxic agent. Peripheral blood lymphocytes in culture were used as a test system, where chromosomal aberrations and sister chromatid exchanges were scored in order to evaluate genotoxicity, and mitotic index and cell proliferation kinetics were used as parameters for cytostatic and cytotoxic ability. Genotoxicity to lymphocytes was negative. However, proliferation was affected by the toxin, demonstrating a cytostatic activity independent of genotoxic damage.

GnRH-induced cytosolic calcium oscillations in pituitary gonadotrophs: phase resetting by membrane depolarization.

Cultured rat pituitary gonadotrophs under whole-cell voltage clamp conditions respond to the hypothalamic hormone GnRH with synchronized oscillatory changes in both cytosolic Ca2+ concentration ([Ca2+]i) and [Ca2+]i-activated, apamin-sensitive K+ current (IK(Ca)). We found, and report here for the first time, that in GnRH-stimulated cells a brief depolarizing pulse can elicit a transient [Ca2+]i rise similar to the endogenous cycle. Furthermore, Ca2+ entry during a single depolarizing pulse was found to shift the phase of subsequent endogenous [Ca2+]i oscillations, which thereafter continue to occur at their previous frequency before the pulse. Application of two consecutive depolarizing pulses showed that the size of the [Ca2+]i rise evoked by the second pulse depended on the time lapsed between two consecutive pulses, indicating that each endogenous or evoked [Ca2+]i rise cycle leaves the Ca2+ release mechanism of the gonadotroph in a refractory state. Recovery from this condition can be described by an exponential function of the time lapsed between the pulses (time constant of ca. 1 s). We propose that the underlying mechanism in both refractoriness after endogenous cycles and phase resetting by a brief pulse of Ca2+ entry involves the InsP3 receptor-channel molecule presumed to be located on the cytosolic aspect of the endoplasmic reticulum membrane.

Properties of the ryanodine receptor present in the sarcoplasmic reticulum from lobster skeletal muscle.

Microsomal sarcoplasmic reticulum (SR) fractions from lobster skeletal muscle were found to bind [3H]-ryanodine. [3H]-ryanodine binding was enhanced by AMP, Ca2+ and caffeine, and significantly diminished by ATP, Ba2+ and Sr2+. Furthermore, dantrolene and ruthenium red, two classical inhibitors of Ca2+ release from the SR, blocked [3H]-ryanodine binding. Similarly, tetracaine, known to block the charge movement associated with excitation-contraction coupling in vertebrate muscle, inhibited the binding of the alkaloid. Our lobster SR preparation exhibited a single high-affinity ryanodine binding site (Kd = 6.6 nM, Bmax = 10 pmol/mg protein). Since SDS-PAGE of the SR proteins revealed a major band c. 565 kDa which comigrated with the putative ryanodine receptor from both rat and chicken skeletal muscle, we concluded that lobster skeletal muscle is equipped with the 565 kDa ryanodine receptor. Finally, incorporation of the SR microsomal fraction from lobster into planar bilayer membranes revealed the presence of a ryanodine-sensitive Ca2+ channel activity (160 pS in symmetrical 200 mM CsCl solutions). We concluded that both the crustacean and vertebrate skeletal muscle ryanodine receptor share the relevant properties such as molecular weight and affinity for ryanodine and inositol 1,4,5 triphosphate. However, there are important differences between the two receptors including differential effects of the alkaloid on the Ca2+ release channel and modulation of the receptor by nucleotides.