Ana Molina

Quantitative changes in the testicular structure in mice exposed to low doses of cadmium.

The purpose of this study was to quantify the consequences of a long-term exposure to low doses of cadmium on the testicular structure. Sexually mature male mice were orally exposed to cadmium (0.015g/1 of CdCl2 in drinking water) for 1, 3, 6 and 12 months and then sacrificed; cadmium withdrawal was also considered in two groups raised with cadmium for 3 and 6 months, and without cadmium for 3 and 6 months before sacrifice, respectively. Morphometrical and stereological estimations were applied to quantify the structural constituents of the testes. The morphological parameters (testicular mass and size) were significantly decreased at 6 and 12 months of cadmium exposure. Interstitium was the testicular constituent most sensitive to cadmium so that significant decreases in the volume fractions of interstitium and Leydig cells were recorded as from 3 months of cadmium exposure. Cadmium-exposed seminipherous tubules showed increased diameters and lumens together with decreased tubular densities and epithelial percentages.

Acute Effects of Microcystins MC-LR and MC-RR on Acid and Alkaline Phosphatase Activities and Pathological Changes in Intraperitoneally Exposed Tilapia Fish (Oreochromis sp.)

Microcystins (MC) are frequently present in cyanobacterial blooms in rivers and lakes, increasing the risk of toxicity to both animals and humans. There more than eighty reported microcystins, and the present study was undertaken to determine whether MC-LR and MC-RR can induce different enzyme alterations and histopathological changes in tilapia fish (Oreochromis sp.) exposed to a single intraperitoneal (i.p.) injection of the pure standards (MC-LR and MC-RR) at a dose of 500 μg/kg; the tilapia fish were then observed for seven days. The two MC variants caused significant changes in the activities of acid and alkaline phosphatases (ACP and ALP) in vital organs, showing a different response pattern. The livers and kidneys of fish injected with MC-LR were particularly affected. MC-RR induced a very pronounced increase of ACP in the kidney and a significant increase of ALP in the liver. Both MC variants caused pathological lesions in hepatic tissues, such as megalocytosis, necrotic process, and microvesicular steatosis, particularly in fish treated with MC-LR, and degenerative renal changes, glomerulopathy, were more severe in tilapias exposed to MC-RR. In addition, both microcystins also caused significant myopathy in the heart. In contrast, the gills did not show any change in enzyme activity or histopathological injury.

Endocrine-active compound evaluation: qualitative and quantitative histomorphological assessment of zebrafish gonads after bisphenol-A exposure.

There is great social concern about the risk involved from exposure to BPA as an endocrine disrupter in humans, as well as the possible repercussion of this chemical on the environment. In this study, the short-term effects of BPA at a gonadal level were assessed by means of different biomarkers in a model animal organism in vogue, the zebrafish (Danio rerio). For this purpose, 60 female zebrafish aged 16 weeks were used. These were exposed for 14 days in aquariums (following OECD Directive no.204) to BPA concentrations of 1, 10, 100 and 1000 μg/L, in addition to a control batch. After the exposure period, the zebrafish were sacrificed and samples taken for a histopathological study by light and electron microscopy and morphometric analysis. During the fourteen days of exposure, water samples were taken from the aquariums to analyze the BPA levels. The BPA concentration in the fish and the water was determined by LC-MS/MS. The gonads of the zebrafish exposed to the BPA had a normal external appearance and there were no variations in their size or body weight. An accumulation of BPA was produced in the zebrafish tissues, and this increased as the BPA concentration to which the fish were exposed did. In the histopathological and morphometric studies, multiple alterations were observed in the zebrafish ovaries, particularly highlighting the vacuolization of the follicular cytoplasm, a great degeneration of all the cell components, and an important increase in the percentage of atretic follicles as from concentrations of 100 and 1000 μg/L of BPA, verified by morphometry. These data indicate that morphological endpoints are sufficiently sensitive to individuate early effects of environmental concentration of BPA on gonads after two weeks of exposure.

Air spore microfungi in dwellings of south of Spain

SummaryIndoor and outdoor airborne microfungi were studied in fourteen homes of Córdoba (Spain) for two years. Samplings were done gravimetrically in three rooms in each home and, for comparison, also outdoors. An overall 128 taxa were identified, which were classified according to their occurrence into occasional, frequent and permanent. No statistically significant quantitative differences were found between the microfungi in each room. On the other hand, there were significant quantitative differences between indoor and outdoor microfungi. Spores occurred at their maximum concentrations in spring. Finally,Aspergillus andCladosporium were found to be the most abundant genera indoors and outdoors, respectively.Indoor and outdoor airborne microfungi were studied in fourteen homes of Cordoba (Spain) for two years. Samplings were done gravimetrically in three rooms in each home and, for comparison, also outdoors. An overall 128 taxa were identified, which were classified according to their occurrence into occasional, frequent and permanent. No statistically significant quantitative differences were found between the microfungi in each room. On the other hand, there were significant quantitative differences between indoor and outdoor microfungi. Spores occurred at their maximum concentrations in spring. Finally,Aspergillus andCladosporium were found to be the most abundant genera indoors and outdoors, respectively.

Preliminary statistical modeling of the presence of two conidial types ofCladosporium in the atmosphere of Córdoba, Spain

In this study we report an aerobiological sampling of the atmosphere of Córdoba, in which airborne conidia belonging to the genusCladosporium were volumetrically counted for a period of 3 years. Two types ofCladosporium conidia were identified, differentiated by their morphological characteristics: the typecladosporioides and the typeherbarum. Correlation analyses with meteorological parameters have shown that daily mean temperature and relative humidity were the most influential factors governing the daily presence ofCladosporium in the atmosphere. Regression analyses were also done in order to establish predictive models of future airborne concentrations. The models that have shown the best adjustment to our data set have been obtained through the utilization of the weekly average temperature prior to the conidia forecast as an independent variable and the 5-day moving average conidia count as the dependent variable. Finally, our statistical analyses showed that variations of theherbarum type adjust more closely to the model of variations obtained than that of thecladosporioides type.

Quantitative Study of Leydig Cell Populations in Mice Exposed to Low Doses of Cadmium

Leydig cell morphological changes were evaluated using morphometric and stereological methods in male mice exposed to low doses of cadmium. A possible reversibility of the changes after cadmium withdrawal was also considered. Nuclear morphological parameters and stereological densities of the Leydig cell population were lower in the cadmium-exposed groups than in the control. The withdrawal of cadmium did not lead to any significant recovery of the morphological parameters. Nevertheless, numerical density increased significantly in the withdrawn groups, suggesting that the hyperplasia of interstitial cells could try to relieve morphological damage after cadmium withdrawal.

Presence ofAspergillus Mich. ex Fr. in several different biotopes in Córdoba (Spain)

The medical, veterinary and saprophytic importance ofAspergillus has been acknowledged by many authors. This paper reports on the occurrence ofAspergillus species in the air and dust of Córdoba (Spain). Four studied were done: first, on the air of three rooms and the outside area of 14 homes over 2 years; second, outdoor air in the west of the central district, with three samples daily over 1 year; third, the air inside and outside four of the largest silos and commercial grain warehouses in the province, over 1 year: and fourth, the dust of 12 primary schools in Córdoba city, for two consecutive school years. For air-sampling, volumetric and gravimetric methods were used, both with a culture medium and with 20-min exposure. For dust-sampling, a customised vacuum cleaner was used; samples collected were inoculated onto Petri dishes containing culture medium. A total of 38Aspergillus species were identified (we also detected four ascosporic states). A comparison of the results obtained at each of the sampling sites was made and an analysis of variance revealed quantitatively significant differences between sampling times.

Adverse effects of bisphenol A on the testicular parenchyma of zebrafish revealed using histomorphological methods

The purpose of this study was to evaluate the consequences of bisphenol A (BPA) exposure in zebrafish (Danio rerio). Short-term effects at a testes level were assessed by means of different biomarkers in 60 male zebrafish exposed for 14 days in aquariums to different concentrations of BPA (1, 10, 100 and 1000 μg/l) in addition to a control batch. The LC-MS/MS method was used for the quantification of BPA. The BPA levels in the zebrafish tissues increased together with increasing exposure of fish to BPA. Several alterations were observed in the zebrafish testes. Particularly notable morphological changes included, a pronounced degeneration of all cell components, an increase in the percentage of the sustentacular (Sertoli) cells, and a marked decrease in the percentage of germ cells starting from concentrations of 100 μg/l of BPA. Our results indicate that histopathology and testes morphometry are sensitive biomarkers for the analysis of early effects of an environmental concentration of BPA in zebrafish experimental models. Our observations reveal that the nature and intensity of the morphological changes in the testes are concentration-dependent in the case of BPA, and manifest as adverse effects on the fish’s reproductive health.

Evaluation of toxicological endpoints in female zebrafish after bisphenol A exposure

Given the importance of bisphenol A (BPA) as a xenoestrogen and its potential effects on human and animal health, we evaluated BPA exposures short-term effects on follicular development, yolk protein vitellogenin (VTG) production and aromatase expression in female zebrafish. Histological modifications were observed along with increased presence of atretic follicles. Whole-body VTG concentration increased with the dose of BPA exposure. In contrast, expression of Cyp19a mRNA in the ovaries of BPA-exposed fish exhibited an apparent non-monotonic response curve, marked by downregulation at 1 μg/L BPA, upregulation at 10 μg/L BPA, and a return to downregulation at 100 μg/L BPA and higher doses. Ovaries only exhibited significant increases in follicular atresia and VTG concentration after exposure to 100 μg/L BPA and higher doses. Ovarian histopathology, aromatase Cyp19a transcript levels and whole-body VTG protein abundance may be good biomarkers for early detection of environmental BPA exposure.

Analyses of anaesthesia with ketamine combined with different sedatives in rats.

The goal of this study was to establish an easy-to-perform, reliable, and safe protocol for intraperi - toneal injection anaesthesia in rats, as well as an easy method to assess anaesthesia depth under routine clini - cal conditions. Seventy Wistar rats (35 males and 35 females) were used to evaluate intraperitoneal anaesthesia with ketamine (75 mg/kg) combined with one of the following central nervous system depressors: acepromazine (2.5 mg/kg), diazepam (5 mg/kg), medetomidine (0.5 mg/kg), midazolam (5 mg/kg) and xylazine (2.5 mg/kg). Sig - nificant differences were found between the combinations in ataxia, recovery and righting parameters, as well as respiratory and heart rates and haemoglobin saturation by oxygen, whereas significant differences between sexes for the parameters of ataxia, hypnosis, recovery, righting and exploratory behaviour were observed upon waking. The best results for parameters such as induction, and maintenance and recovery from anaesthesia (more regular and stable) were observed with α 2 -agonists: ketamine/xylazine in males and ketamine/medetomidine in females.