EPR detection of paramagnetic chromium in liver of fish (Anguilla anguilla) treated with dichromate(VI) and associated oxidative stress responses—Contribution to elucidation of toxicity mechanisms

The impact of chromium (Cr) on fish health has been the subject of numerous investigations, establishing a wide spectrum of toxicity, attributed particularly to the hexavalent form [Cr(VI)]. However, reports on the simultaneous assessment of Cr toxicity in fish and its toxico-kinetics, namely involving metal speciation, are scarce. Therefore, keeping in view the understanding of the mechanisms of Cr(VI) toxicity, this work intended to detect the formation of paramagnetic Cr species in liver of Anguilla anguilla following short-term dichromate(VI) intraperitoneal treatment (up to 180 min), assessing simultaneously the pro-oxidant properties. The formation of Cr(V) and Cr(III) was examined by electron paramagnetic resonance (EPR), as an innovative approach in the context of fish toxicology, and related with the levels of total Cr. Cr(V) was successfully detected and quantified by EPR spectrometry, showing a transient occurrence, mostly between 15 and 90 min post-injection, with a peak at 30 min. The limitations of EPR methodology towards the detection and quantification of Cr(III) were confirmed. Although Cr(VI) exposure induced the antioxidant system in the eel's liver, the oxidative deterioration of lipids was not prevented. Overall, the results suggested that Cr(V), as a short-lived species, did not appear to be directly and primarily responsible for the cellular damaging effects observed, since stress responses persisted up to the end of exposure regardless Cr(V) drastic decay. Though further research is needed, ROS mediated pathways (suggested by superoxide dismutase and catalase activity induction) and formation of Cr(III) complexes emerged as the most plausible mechanisms involved in Cr(VI) toxicity.     

Ghrelin induces apoptosis in colon adenocarcinoma cells via proteasome inhibition and autophagy induction

Ghrelin is a metabolism-regulating hormone recently investigated for its role in cancer survival and progression. Controversially, ghrelin may act as either anti-apoptotic or pro-apoptotic factor in different cancer cells, suggesting that the effects are cell type dependent. Limited data are currently available on the effects exerted by ghrelin on intracellular proteolytic pathways in cancer. Both the lysosomal and the proteasomal systems are fundamental in cellular proliferation and apoptosis regulation. With the aim of exploring if the proteasome and autophagy may be possible targets of ghrelin in cancer, we exposed human colorectal adenocarcinoma cells to ghrelin. Preliminary in vitro fluorimetric assays evidenced for the first time a direct inhibition of 20S proteasomes by ghrelin, particularly evident for the trypsin-like activity. Moreover, 1 μM ghrelin induced apoptosis in colorectal adenocarcinoma cells by inhibiting the ubiquitin–proteasome system and by activating autophagy, with p53 having an “interactive” role.     

Grazing history influences biodiversity: a case study on ground-dwelling arachnids (Arachnida: Araneae, Opiliones) in the Natural Park of Alpi Marittime (NW Italy)

Alpine pastures are typical examples of “high nature value farmlands”, representing important habitats harbouring unique biological communities. Disturbance induced by overgrazing influences significantly ecosystem processes, in which invertebrates play a major role. To develop new models of sustainable management of pastures, more knowledge is needed of the animal communities, essential to the ecological functioning of pasture ecosystems. The apparent poor ecological state of several pastures in the Natural Regional Park of Alpi Marittime (NW-Italy) lead us to evaluate the influence of grazing history on biodiversity, using spider and harvestmen assemblages as key groups. Four different pastoral types characterized by four different grazing histories were identified using the Daget-Poissonet method. Spiders and harvestmen were collected by means of pitfall traps. Arachnid assemblages were characterized in terms of composition, abundance, species richness, richness of endemic species and taxonomic relatedness. Generalized linear mixed models (GLMM) were used to test differences among assemblages occurring in each pastoral type. Furthermore, we tested differences in terms of plant communities (species richness and percentage of zoogenic species). Specificity and fidelity of every spider and harvestmen species within pastoral types were explored by the IndVal (Indicator Value) procedure. Fifty-eight species of spiders and seven species of harvestmen were collected (2,304 individuals). Pastoral types related to intensive grazing were characterized by the dominance of diurnal wanderer spiders (namely Lycosidae) while, conversely, nocturnal wanderers (mainly Gnaphosidae) were more abundant in extensive pastoral types. Results show that both species richness and spider abundance were higher in abandoned areas of extensive grazing, while endemic assemblages were richer in extensive grazed areas, which also hosted the most diverse plant community. Furthermore, most of the indicator species of spiders of this type were endemic, characterized by more demanding ecological requirements.     

Comorbidities in Children and Adolescents with AIDS Acquired by HIV Vertical Transmission in Vitória,Brazil

Background

Studying diseases associated with AIDS is essential for establishing intervention strategies because comorbidities can lead to death. The objectives were to describe the frequency of comorbidities and verify their distribution according to demographic, epidemiological and clinical data as well as to classify diseases in children and adolescents with AIDS in Vitória, Brazil.

Methods

A retrospective cohort study was conducted among children with AIDS, as defined according to the criteria established by the Ministry of Health, who acquired HIV via vertical transmission, were aged 0 to 18 years, and were monitored at a referral hospital from January 2001 to December 2011.

Results

A total of 177 patients were included, of whom 97 were female (55%). There were 60 patients (34%) <1 year old, 67 patients (38%) between the ages of 1 and 5, and 50 patients (28%) ≥6 years of age included at the time of admission to the Infectious Diseases Ward. Regarding clinical-immunological classification, 146 patients (82.5%) showed moderate/severe forms of the disease at the time of admission into the Ward, and 26 patients (14.7%) died during the study. The most common clinical signs were hepatomegaly (81.62%), splenomegaly (63.8%), lymphadenopathy (68.4%) and persistent fever (32.8%). The most common comorbidities were anaemia (67.2%), pneumonia/septicaemia/acute bacterial meningitis (ABM) (64.2%), acute otitis media (AOM)/recurrent sinusitis (55.4%), recurrent severe bacterial infections (47.4%) and dermatitis (43.1%). An association between severe clinical-immunological classification and admission to the Ward for children aged less than one year old was found for several comorbidities (p<0.001).

Conclusion

Delayed diagnosis was observed because the majority of patients were admitted to the Infectious Diseases Ward at ≥1 year of age and were already presenting with serious diseases. The general paediatrician should be alert to this possibility to make an early diagnosis in children infected with HIV.     

Occurrence of Nontuberculous Mycobacterial Pulmonary Infection in an Endemic Area of Tuberculosis

The majority of investigations of the epidemiology of nontuberculous mycobacteria (NTM) have focused on highly developed nations with a low prevalence of tuberculosis. In contrast, the Para state of north Brazil represents an area of high tuberculosis prevalence and increasing NTM incidence. Toward the goal of understanding the dynamics of infection by all Mycobacterium species, we report patient characteristics and the identification of NTM strains isolated from sputum samples from patients that were residents of Para, a state in the Amazon region, Northern of Brazil, over the period January 2010 through December 2011 (2 years). The 29 NTM patients comprised 13.5% of positive mycobacterial cultures over the 2-year period. A major risk factor for NTM pulmonary disease was previous tuberculosis (76%). Further, the average age of NTM patients (52 years) was significantly higher than that of tuberculosis patients (39 years) and more were female (72.4% vs. 37.4%). Unlike other Brazilian states, NTM pulmonary patients in Para were infected with a different spectrum of mycobacteria; primarily the rapidly growing Mycobacterium massiliense and Mycobacterium simiae complex.     

Phylogenetic Analysis Reveals a High Prevalence of Sporothrix brasiliensis in Feline Sporotrichosis Outbreaks

Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1α) loci in strains originated from Rio de Janeiro (RJ, n = 15), Rio Grande do Sul (RS, n = 10), Paraná (PR, n = 4), São Paulo (SP, n = 3) and Minas Gerais (MG, n = 1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil.     

P-I Snake Venom Metalloproteinase Is Able to Activate the Complement System by Direct Cleavage of Central Components of the Cascade

Background

Snake Venom Metalloproteinases (SVMPs) are amongst the key enzymes that contribute to the high toxicity of snake venom. We have recently shown that snake venoms from the Bothrops genus activate the Complement system (C) by promoting direct cleavage of C-components and generating anaphylatoxins, thereby contributing to the pathology and spread of the venom. The aim of the present study was to isolate and characterize the C-activating protease from Bothrops pirajai venom.

Results

Using two gel-filtration chromatography steps, a metalloproteinase of 23 kDa that activates Complement was isolated from Bothrops pirajai venom. The mass spectrometric identification of this protein, named here as C-SVMP, revealed peptides that matched sequences from the P-I class of SVMPs. C-SVMP activated the alternative, classical and lectin C-pathways by cleaving the α-chain of C3, C4 and C5, thereby generating anaphylatoxins C3a, C4a and C5a. In vivo, C-SVMP induced consumption of murine complement components, most likely by activation of the pathways and/or by direct cleavage of C3, leading to a reduction of serum lytic activity.

Conclusion

We show here that a P-I metalloproteinase from Bothrops pirajai snake venom activated the Complement system by direct cleavage of the central C-components, i.e., C3, C4 and C5, thereby generating biologically active fragments, such as anaphylatoxins, and by cleaving the C1-Inhibitor, which may affect Complement activation control. These results suggest that direct complement activation by SVMPs may play a role in the progression of symptoms that follow envenomation.     

IL28B Gene Polymorphisms and US Liver Fatty Changes in Patients Who Spontaneously Cleared Hepatitis C Virus Infection

Background

Recent clinical studies have shown that the presence of CC genotype in the rs12979860 region of IL28B gene is associated with an increase in the probability of spontaneous clearance of hepatitis C virus (HCV). Moreover, IL28B polymorphism seems to influence the probability of developing liver steatosis in chronic HCV patients.

Aims

The aims of our clinical study were 1) to verify the distribution of IL28B genotypes (CC, CT or TT) among subjects with spontaneous clearance of HCV infection and 2) to examine the correlation between IL28B polymorphism and hepatic steatosis among these subjects.

Methods and patients

We enrolled 41 subjects with spontaneous resolution of HCV infection (detectable serum anti-HCV but undetectable HCV-RNA) and 134 healthy controls from the same geographical area. The IL28B single-nucleotide polymorphism (SNP) rs12979860 was genotyped by using a Pyrosequencing™ technique. The presence of steatosis was assessed by liver biopsy or ultrasound examination in the 41 study subjects.

Results

CC, CT and TT-genotypes of the SNP rs1979860 were found in 66%, 24% and 10% of the subjects who spontaneously cleared HCV and in 31%, 54% and 15% of controls, respectively (p = 0.0003). Among the study subjects, females with CC-genotype were significantly more represented (p = 0.02). Hepatic steatosis did not correlate with IL28B genotype (p = 0,14) but only with a high body mass index (BMI) value (p = 0.03).

Conclusions

Female subjects carrying IL28B CC-genotype are significantly more represented among Italian patients who spontaneously cleared HCV infection. In addition, among these subjects, the presence of liver steatosis does not correlate with IL28B genotype but is solely related to the occurrence of high BMI. Thus, the association between IL28B polymorphism and steatosis in chronic HCV patients requires the presence of active HCV replication to occur, while in subjects who have cleared the infection, the mechanism(s) inducing liver steatosis are independent from IL28B profile.