Transgenerational inheritance of methylmercury and vitamin A-induced toxicological effects in a Wistar rats environmental-based model

Mercury (Hg) and vitamin A (VitA) are two environmental factors with potential health impacts, especially during pregnancy and early childhood. Fish and seafood may present elevated levels of methylmercury (MeHg), the major Hg derivative, and VitA. This study aimed to evaluate the transgenerational effects of exposure to MeHg and/or VitA on epigenetic and toxicological parameters in a Wistar rat model. Our findings revealed persistent toxicological effects in generations F1 and F2 following low/mild doses of MeHg and/or VitA exposure during dams' (F0) gestation and breastfeeding. Toxicological effects observed in F2 included chronic DNA damage, bone marrow toxicity, altered microglial content, reduced neuronal signal, and diminished male longevity. Sex-specific patterns were also observed. Co-exposure to MeHg and VitA showed both synergistic and antagonistic effects. Additionally, the study demonstrated that MeHg and VitA affected histone methylation and caused consistent effects in F2. While MeHg exposure has been associated with transgenerational inheritance effects in other organisms, this study provides the first evidence of transgenerational inheritance of MeHg and VitA-induced toxicological effects in rodents. Although the exact mechanism is not yet fully understood, these findings suggest that MeHg and VitA may perpetuate their impacts across generations. The study highlights the need for remedial policies and interventions to mitigate the potential health problems faced by future generations exposed to MeHg or VitA. Further research is warranted to investigate the transgenerational effects beyond F2 and determine the matrilineal or patrilineal inheritance patterns.

Unusual magnetic resonance imaging findings of cystic bone lesions in congenital generalized lipodystrophy

Cystic bone lesions are the hallmark of skeletal abnormalities in patients with congenital generalized lipodystrophy (CGL). However, their pathophysiology is still unclear and theories about their origin remain largely speculative. This article reports on a patient with CGL and cystic bone lesions, some of them with unusual magnetic resonance imaging (MRI) findings that include elevated signal intensity on T1-weighted images and fluid-fluid levels, the latter evolving to a more "classic" cystic appearance on follow-up. Even though similar findings were first described almost 30 years ago, little attention was given to them back then; furthermore, other than the present report, no other study has performed sequential exams to follow their evolution in serial MRI. The authors conduct a review of the literature, hypothesizing that these remarkable findings may reflect an intermediate stage in the process of cystification of the abnormal bone marrow, incapable to perform adipose conversion, lending factual support to the modern theories about this issue.

Hepatic and neurobiological effects of foetal and breastfeeding and adulthood exposure to methylmercury in Wistar rats

Methylmercury (MeHg) is an organic bioaccumulated mercury derivative that strongly affects the environment and represents a public health problem primarily to riparian communities in South America. Our objective was to investigate the hepatic and neurological effects of MeHg exposure during the phases foetal and breast-feeding and adult in Wistar rats. Wistar rats (n = 10) were divided into 3 groups. Control group received mineral oil; The simple exposure (SE) group was exposed only in adulthood (0.5 mg/kg/day); and double exposure (DE) was pre-exposed to MeHg 0.5 mg/kg/day during pregnancy and breastfeeding (±40 days) and re-exposed to MeHg for 45 days from day 100. After, we evaluated possible abnormalities. Behavioral and biochemical parameters in liver and occipital cortex (CO), markers of liver injury, redox and AKT/GSK3β/mTOR signaling pathway. Our results showed that both groups treated with MeHg presented significant alterations, such as decreased locomotion and exploration and impaired visuospatial perception. The rats exposed to MeHg showed severe liver damage and increased hepatic glycogen concentration. The MeHg groups showed significant impairment in redox balance and oxidative damage to liver macromolecules and CO. MeHg upregulated the AKT/GSK3β/mTOR pathway and the phosphorylated form of the Tau protein. In addition, we found a reduction in NeuN and GFAP immunocontent. These results represent the first approach to the hepatotoxic and neural effects of foetal and adult MeHg exposure.

Nuclear RXRα and RXRβ receptors exert distinct and opposite effects on RA-mediated neuroblastoma differentiation

Retinoic acid (RA) promotes differentiation in multiple neurogenic cell types by promoting gene reprogramming through retinoid receptors and also by inducing cytosolic signaling events. The nuclear RXR receptors are one of the main mediators of RA cellular effects, classically by joining the direct receptors of RA, the nuclear RAR receptors, in RAR/RXR dimers which act as transcription factors. Distinct RXR genes lead to RXRα, RXRβ and RXRγ subtypes, but their specific roles in neuronal differentiation remain unclear. We firstly investigated both RXRs and RARs expression profiles during RA-mediated neuronal differentiation of human neuroblastoma cell line SH-SY5Y, and found varying levels of retinoid receptors transcript and protein contents along the process. In order to understand the roles of the expression of distinct RXR subtypes to RA signal transduction, we performed siRNA-mediated silencing of RXRα and RXRβ during the first stages of SH-SY5Y differentiation. Our results showed that RXRα is required for RA-induced neuronal differentiation of SH-SY5Y cells, since its silencing compromised cell cycle arrest and prevented the upregulation of neuronal markers and the adoption of neuronal morphology. Besides, silencing of RXRα affected the phosphorylation of ERK1/2. By contrast, silencing of RXRβ improved neurite extension and led to increased expression of tau and synaptophysin, suggesting that RXRβ may negatively regulate neuronal parameters related to neurite outgrowth and function. Our results indicate distinct functions for RXR subtypes during RA-dependent neuronal differentiation and reveal new perspectives for studying such receptors as clinical targets in therapies aiming at restoring neuronal function.

Anti-RAGE antibody selectively blocks acute systemic inflammatory responses to LPS in serum, liver, CSF and striatum

Systemic inflammation induces transient or permanent dysfunction in the brain by exposing it to soluble inflammatory mediators. The receptor for advanced glycation endproducts (RAGE) binds to distinct ligands mediating and increasing inflammatory processes. In this study we used an LPS-induced systemic inflammation model in rats to investigate the effect of blocking RAGE in serum, liver, cerebrospinal fluid (CSF) and brain (striatum, prefrontal cortex, ventral tegmental area and substantia nigra). Intraperitoneal injection of RAGE antibody (50μg/kg) was followed after 1h by a single LPS (5mg/kg) intraperitoneal injection. Twenty-four hours later, tissues were isolated for analysis. RAGE antibody reduced LPS-induced inflammatory effects in both serum and liver; the levels of proinflammatory cytokines (TNF-α, IL-1β) were decreased and the phosphorylation/activation of RAGE downstream targets (ERK1/2, IκB and p65) in liver were significantly attenuated. RAGE antibody prevented LPS-induced effects on TNF-α and IL-1β in CSF. In striatum, RAGE antibody inhibited increases in IL-1β, Iba-1, GFAP, phospho-ERK1/2 and phospho-tau (ser202), as well as the decrease in synaptophysin levels. These effects were caused by systemic RAGE inhibition, as RAGE antibody did not cross the blood-brain barrier. RAGE antibody also prevented striatal lipoperoxidation and activation of mitochondrial complex II. In conclusion, blockade of RAGE is able to inhibit inflammatory responses induced by LPS in serum, liver, CSF and brain.

Effect of fixed-time embryo transfer on reproductive efficiency in high-producing repeat-breeder Holstein cows

The aim of the present study was to compare a synchronization of time of ovulation protocol for fixed-timed embryo transfer (FTET) with the usual administration of a single dose of prostaglandin associated with detection of estrus. Also, the effect of the presence of CL at the beginning of FTET protocol was evaluated. Lactating Holstein cows (n=651) with three previous artificial inseminations were classified according to presence or absence of a corpus luteum (CL). Cows with a CL were randomly assigned to two additional treatments and submitted to embryo transfer after detection of estrus (PGF-Estrus) or FTET (FTET-CL). Cows without CL were allocated to the FTET-NoCL treatment. On a random day of the estrous cycle (Day 0), cows in the PGF-Estrus treatment (n=229) were treated with 150 microg d-cloprostenol (PGF) i.m. followed by detection of estrus from Day 1 through Day 5 after PGF. Embryos were transferred 6-8 days after estrus detection. Cows in the FTET-CL (n=208; presence of CL) and FTET-NoCL (n=214; absence of CL) treatments received a norgestomet ear implant plus 2mg estradiol benzoate (EB) and 50mg progesterone i.m. on Day 0. On Day 8, the implant was removed and 400 IUeCG, 150 microg d-cloprostenol and 1mg estradiol cypionate i.m. were administered. No detection of estrus was performed and Day 10 was arbitrarily considered as the estrus day. Ultrasonographic exams were performed in all recipients and only cows with a single CL> or =15 mm or multiple CL received a fresh or frozen-thawed embryo on Day 17. Pregnancy was diagnosed by ultrasonography at 30 and 60 days of pregnancy. When FTET and PGF-Estrus were compared, the proportion of cows receiving an embryo (recipients transferred-to-treated rate) was greater in the FTET-CL (75.0% (156/208) than in PGF-Estrus (34.5%, 79/229; P<0.0001) treatment. Pregnancy rate (60 days) was also greater in FTET-CL (29.3%, 61/208) when compared to PGF-Estrus (16.2%, 37/229; P=0.001). However, no differences were found in pregnancy loss [PGF-Estrus=11.9% (5/42), FTET-CL=9.0% (6/67); P=0.62] and circulating progesterone concentration at embryo transfer [PGF-Estrus=4.02+/-0.52 ng/mL (n=25), FTET-CL=3.33+/-0.32 ng/mL (n=27); P=0.25] among these treatments. The presence of CL at the beginning of FTET protocol resulted greater transferred-to-treated rate [FTET-CL=75.0% (156/208) vs. FTET-NoCL=61.2% (131/214); P=0.003], but showed no effect on pregnancy rate at 60 days [FTET-CL=29.3% (61/208) vs. FTET-NoCL=22.9% (49/214); P=0.13], pregnancy loss [FTET-CL=9.0% (6/67) vs. FTET-NoCL=2.0% (1/50); P=0.15] and circulating progesterone concentration at ET [FTET-CL=3.33+/-0.32 ng/mL (n=27) compared to FTET-NoCL=3.44+/-0.40 ng/mL (n=2 9); P=0.82]. In conclusion, the protocol for synchronization of time of ovulation using norgestomet ear implant, EB and eCG increased recipients transferred-to-treated and pregnancy rates in high-producing repeat-breeder Holstein cows. Also, recipients without CL at the beginning of the time of ovulation synchronization treatment resulted in similar pregnancy rate as recipients with CL submitted to FTET protocol. Thus, the suggested protocol allowed the performance of FTET, without the need for detection of estrus, simplifying the reproductive management and increasing the reproductive efficiency in repeat-breeder Holstein recipients.

Anaerobic digestion of space mission wastes

The technical feasibility of applying leachbed high-solids anaerobic digestion for reduction and stabilization of the organic fraction of solid wastes generated during space missions was investigated. This process has the advantages of not requiring oxygen or high temperature and pressure while producing methane, carbon dioxide, nutrients, and compost as valuable products. Anaerobic biochemical methane potential assays run on several waste feedstocks expected during space missions resulted in ultimate methane yields ranging from 0.23 to 0.30 L g-1 VS added. Modifications for operation of a leachbed anaerobic digestion process in space environments were incorporated into a new design, which included; (1) flooded operation to force leachate through densified feedstock beds; and (2) separation of biogas from leachate in a gas collection reservoir. This mode of operation resulted in stable performance with 85% conversion of a typical space solid waste blend, and a methane yield of 0.3 Lg per g VS added after a retention time of 15 days. These results were reproduced in a full-scale prototype system. A detailed analysis of this process was conducted to design the system sized for a space mission with a six-person crew. Anaerobic digestion compared favorably with other technologies for solid waste stabilization.

The source of ochratoxin A in Brazilian coffee and its formation in relation to processing methods

A total of 408 Brazilian coffee samples was examined during the 1999 and 2000 coffee harvest seasons for the presence of ochratoxin A (OA) and fungi with the potential to produce it. Samples came from four regions: Alta Paulista (western area of São Paulo State), Sorocabana (southwest São Paulo State), Alta Mogiana (northeast São Paulo State) and Cerrado Mineiro (western area of Minas Gerais State). Cherries and beans were examined at different stages: immature, mature and overripe cherries from trees, overripe cherries from the ground and beans during drying and storage on the farm. For mycological studies, the cherries and beans were surface disinfected with chlorine, plated on Dichloran 18% Glycerol Agar at 25 degrees C for 5-7 days and analysed for the presence of Aspergillus ochraceus and closely related species, A. carbonarius and A. niger. More than 800 isolates of fungi belonging to these species were identified and studied for the ability to produce OA using the agar plug technique and thin layer chromatography (TLC). A. niger was the species found most commonly (63% of isolates of these three species), but only 3% of them produced OA. A. ochraceus also occurred commonly (31% of isolates), and 75% of those studied were capable of OA production, a much higher percentage than reported elsewhere. A. carbonarius was found (6% of isolates) only in Alta Paulista, the hottest region studied, and only from beans in the drying yard or in storage. However, 77% of the A. carbonarius isolates were capable of producing OA. Average infection rates for cherries taken from trees were very low, but were higher in fruit taken from the ground, from the drying yard and from storage, indicating infection by toxigenic species after harvest. The average OA content in 135 samples of mature cherries from trees, overripe from trees, overripe from the ground, drying yard and storage was 0.1, <0.2, 1.6, 2.1 and 3.3 microg/kg, respectively. Although individual OA levels varied widely, only 9 of the 135 samples analysed exceeded 5 microg/kg OA, with one sample of poor quality dried coffee in excess of 100 microg/kg OA. The causes of high contamination were investigated on the farms concerned and several critical points were found, relating both to local climatic conditions and the drying processes used.

The West Nile virus encephalitis outbreak in the United States (1999-2000): from Flushing, New York, to beyond its borders

Viruses cause most forms of encephalitis. The two main types responsible for epidemic encephalitis are enteroviruses and arboviruses. The City of New York reports about 10 cases of encephalitis yearly. Establishing a diagnosis is often difficult. In August 1999, a cluster of five patients with fever, confusion, and weakness were admitted to a community hospital in Flushing, New York. Flaccid paralysis developed in four of the five patients, and they required ventilatory support. Three, less severe, cases presented later in the same month. An investigation was conducted by the NewYork City (NYC) and New York State (NYS) health departments and the national Centers for Disease Control and Prevention (CDC). The West Nile virus (WNV) was identified as the etiologic agent. WNV is an arthropod-borne flavivirus, with a geographic distribution in Africa, the Middle East, and southwestern Asia. It has also been isolated in Australia and sporadically in Europe but never in the Americas. The majority of people infected have no symptoms. Fever, severe myalgias, headache, conjunctivitis, lymphadenopathy, and a roseolar rash can occur. Rarely, encephalitis or meningitis is seen. The NYC outbreak resulted in the first cases of WNV infection in the Western Hemisphere and the first arboviral infection in NYC since yellow fever in the nineteenth century. The WNV is now a public health concern in the United States.

Kinetic parameters estimation for ascorbic acid degradation in fruit nectar using the Partial Equivalent Isothermal Exposures (PEIE) method under non-isothermal continuous heating conditions

With the purpose of testing the Paired Equivalent Isothermal Exposures (PEIE) method to determine reaction kinetic parameters under non-isothermal conditions, continuous pasteurizations were carried out with a tropical fruit nectar [25% cupuaçu (Theobroma grandiflorum) pulp and 15% sugar] to estimate the ascorbic acid thermal degradation kinetic parameters. Fifteen continuous thermal exposures were studied, with seven being cycled. The experimental ascorbic acid thermal degradation kinetic parameters were estimated by the PEIE method (E(a) = 73 +/- 9 kJ/mol, k(8)(0)( degrees )(C) = 0.017 +/- 0.001 min(-)(1)). These values compared very well to the previously determined values for the same product under isothermal conditions (E(a) = 73 +/- 7 kJ/mol, k(8)(0)( degrees )(C) = 0.020 +/- 0.001 min(-)(1)). The predicted extents of reaction presented a good fit to the experimental data, although the cycled thermal treatments presented some deviation. In addition to being easier and faster than the Isothermal method, the PEIE method can be a more reliable method to estimate first-order reaction kinetic parameters when continuous heating is considered.

Comparison of capillary and test tube procedures for analysis of thermal inactivation kinetics of mold spores

Characteristics of capillary and test tube procedures for thermal inactivation kinetic analysis of microbial cells were studied for mold spores. During heating, capillaries were submerged in a water bath and test tubes were held with their caps positioned above the level of the heating medium. Thermal inactivation curves of Aspergillus niger spores in capillaries at around 60 degrees C consisted of a shoulder and a fast linear decline, whereas curves in test tubes consisted of a shoulder, a fast linear decline, and a horizontal tail. There were no significant differences in values of the rate and the delay of fast declines in curves between the procedures. Some experiments were done to clarify the cause for tailing with test tubes. There were no tails with test tubes whose inner walls were not contaminated by A. niger spores, suggesting that tails arise from A. niger spores contaminating the inner walls of test tubes. Temperature of the inner wall at the level of a heating medium was lower than that of the medium. Further, there were no tails for test tubes submerged in the heating medium. These results showed that the reason for survival of contaminants on the upper wall of test tubes was that cells were not subjected to sufficient inactivation temperature. Finally, thermal inactivation curves of A. niger spores in capillaries at various constant temperatures were studied. Curves consisted of a shoulder and a fast linear decline at 57 degrees C and above, whereas curves at below 57 degrees C consisted of a shoulder, a fast linear decline, and a sloping tail.

The West Nile Virus outbreak of 1999 in New York: the Flushing Hospital experience

West Nile Virus (WNV) is a mosquito-borne flavivirus, which has been known to cause human infection in Africa, the Middle East, and southwestern Asia. It has also been isolated in Australia and sporadically in Europe but never in the Americas. Clinical features include acute fever, severe myalgias, headache, conjunctivitis, lymphadenopathy, and a roseolar rash. Rarely is encephalitis or meningitis seen. During the month of August 1999, a cluster of 5 patients with fever, confusion, and weakness were admitted to the intensive care unit of the same hospital in New York City. Ultimately 4 of the 5 developed flaccid paralysis and required ventilatory support. Three patients with less-severe cases presented shortly thereafter. With the assistance of the New York City and New York State health departments and the Centers for Disease Control and Prevention, these were documented as the first cases of WNV infection on this continent.

Hepatic abscess in Crohn's disease

Hepatic abscess is a rare complication of Crohn's disease. The present report describes an additional case diagnosed by CT scanning and successfully treated by surgery. Recognition of this complication is important because early therapy could improve the prognosis.

Effects of denervation induced by 6-hydroxydopamine on cell nucleus activity of arterial and cardiac cells of the dog

1 Denervation was induced in dogs by 6-hydroxydopamine (6-OHDA) treatment. The effects of this on cell nucleus activity of smooth muscle cells and fibroblasts of the mesenteric artery (main trunk and jejunal branches) and of myocardial cells, fibroblasts and endothelial capillary cells of the heart were studied. 2 Changes in the nucleii or cell size measured with light microscopy morphometric techniques and frequency of nucleoli in myocardial cells were chosen as indices of cell nucleus activity state. 3 Noradrenaline depletion 5 days after initiation of 6-OHDA administration was much more marked in the heart (with a content of 10% of control values) than in the arterial vessels (with a content of 50% of control values). 4 Denervation by 6-OHDA led to an increase in the synthetic activity state of the cell nucleus in all cell types and tissues. 5 Plasma noradrenaline and adrenaline levels were strikingly increased by 6-OHDA treatment. 6 The results strongly support the hypothesis of a nuclear modulating effect of the sympathetic innervation upon the effector cells. The incapacity of high noradrenaline plasma levels to prevent the consequences of sympathetic denervation on the effector cells appears to indicate that in the sympathetic innervation there is a 'trophic factor' which is not identical with noradrenaline.

Structural and functional alterations caused at the extraneuronal level by sympathetic denervation of blood vessels

The lateral saphenous vein of the dog and the rabbit ear artery were surgically denervated, by clamping the vessel or by removal of the superior cervical ganglion, respectively. Both procedures resulted in denervation of the vessels. The denervated, lateral saphenous vein was supersensitive to exogenous noradrenaline and inactivation of the amine (in oil immersion experiments) was slower in denervated vein strips than in control strips treated with cocaine. Incubation experiments with 3H-noradrenaline confirmed that denervated strips formed considerably fewer metabolites than control ones (in the absence or presence of cocaine) and that O-methylation of noradrenaline was reduced by about 50%. When the strips were incubated with 3H-isoprenaline, the denervated ones accumulated and metabolized isoprenaline to a lesser degree than control strips. Hydrocortisone did not reduce the accumulation of isoprenaline in the denervated vein and had only minor effects on O-methylation. The metabolism of noradrenaline and isoprenaline gradually recovered with time. In the ear artery, denervation was accompanied by a marked reduction in O-methylation, but not in accumulation, of isoprenaline. In both vessels there was a highly significant positive correlation between noradrenaline content and O-methylating capacity; in the saphenous vein accumulation of isoprenaline was also positively correlated to noradrenaline content. Morphological changes observed in the denervated vessels consisted essentially in dedifferentiation of smooth muscle cells (which attained larger dimensions, had an indented, large nucleus, augmented euchromatin and an increased amount of ribosomes), abundance of extracellular material and fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)