A reliable assessment of the viability of schistosome eggs trapped in host tissues is difficult. The use of a coupling azo dye method for the detection of alkaline phosphatase (A1P) in Schistosoma mansoni ova was found to be a specific and sensitive method for differentiating between viable and dead eggs, and can be used in both immature and mature eggs. In fully developed miracidia within an egg, A1P activity was demonstrated in germ cells and in the sensory endings of the neural cells. The embryonating miracidia displayed A1P activity on the body surface and in von Lichienberg’s envelope. The alkaline phosphatase test for egg viability shows increased sensitivity when compared with the more conventional Oogram and Hatching tests.
The increasing worldwide production of bisphenols has been associated to several human diseases, such as chronic respiratory and kidney diseases, diabetes, breast cancer, prostate cancer, behavioral troubles and reproductive disorders in both sexes. The aim of the present in vitro study was to evaluate the potential impact bisphenols A, B, S and F on the cell viability and testosterone release in TM3 Leydig cell line. Mice Leydig cells were cultured in the presence of different concentrations of bisphenols (0.04-50 µg.ml-1 ) during 24 h exposure. Quantification of the cell viability was assessed using the metabolic activity assay, while the level of testosterone in cell culture media was determined by enzyme-linked immunosorbent assay. Within the panel of substances under investigations, the higher experimental concentrations (10; 25 and 50 µg.ml-1 ) significantly (P<0.001) decreased Leydig cells viability, while the same doses of BPA and BPB also reduced testosterone production significantly (P<0.001). Taken together, the results of our study reported herein is a consistent whit the conclusion that higher experimental doses of bisphenols have a cytotoxic effect and could have a dose-dependent impact on testosterone production.
Fascioliasis due to Fasciola hepatica (Linnaeus, 1758) is an endemic disease on the Northern Bolivian Altipiano, where human prevalences and intensities arc the highest known, sheep and cattle are the main reservoir hosts, and pigs and donkeys the secondary ones. Investigations were carried out to study the viability of metacercariae experimentally obtained from eggs shed by naturally infected Altiplanic sheep, cattle, pigs and donkeys. A total of 157 Wistar rats were infected with doses of 5, 10, 20 and 150 metacercariae. Metacercariae aged for different number of weeks were used to analyse the influence of age on their viability. The number of worms successfully developed in each rat was established by dissection. Results obtained show that metacercarial infectivity is dependent upon storage time, being lower when metacercariae arc older. The maximum longevity is 31 weeks using doses of 20 metacercariae per rat and 48 weeks with 150 metacercariae per rat, although in the latter case only a very low percentage of worms is recovered. Age-related infectivity of metacercariae from Altiplanic F. hepatica does not significantly differ from that of the liver fluke in lowlands of other countries. Concerning the influence of the isolate according to host species, results indicate that metacercarial viabilities of pig and donkey isolates are similar to the viabilities of metacercariae of sheep and cattle isolates. Thus, pig and donkey have a high transmission potential capacity concerning this aspect. This fact is of great importance for the control of human and animal fascioliasis in this highly endemic zone.
Little is known about the viability of myxozoan actinospore stages after harvest from laboratory cultures of infected oligochaete worms. The viability and reactivity of actinospores of three myxozoan species was evaluated after short-term storage at 4°C and 12°C. Two methods of determining actinospore viability were compared: differential fluorescent staining and direct microscopic observation of morphological indicators of spore integrity. Spore reactivity was quantified by measuring polar filament discharge rates in a micro-assay with fish mucus substrate and mechanical stimulation by vibration. The age-dependent viability of the three species showed clear differences. Myxobolus cerebralis actinospores had the shortest effective life span whereas Henneguya nuesslini actinospores survived significantly longer. Storage at lower temperatures yielded higher viability in all species. Myxobolus pseudodispar actinospores were significantly robust up to 12°C when assessed by staining, but showed similar viability characteristics as H. nuesslini when analyzed morphologically. Evaluation of spore viability by fluorescent staining correlated with morphological assessment, although fewer viable actinospores were usually detected microscopically. Polar filament discharge activity of morphologically intact actinospores did not significantly decrease until the third day of storage compared to freshly harvested samples. The results indicate that durability and reactivity trends during storage of actinospores differ among myxozoan species.
Fluctuating asymmetry (FA), the small and random departures from perfect symmetry of an organism's bilateral traits, has been used as a measurement of developmental stability and an indicator of stress in endangered populations. We were interested in testing if the level of developmental stability is the same in different populations experiencing the same conditions, as the use of FA as an indicator of ecological stress is only meaningful if this is true. In order to do this, the effect of thermal stress on wing size FA over a range of temperatures was determined on three different lines of Drosophila melanogaster: two lines were maintained at one of two different constant temperatures (18°C or 28°C) and one under a fluctuating thermal regime (18°C and 28°C) for eight years. The differences in viability of these lines, when reared at a range of different temperatures, are associated with the temperature conditions they previously experienced. All lines showed a similar increase in FA at the two ends of the thermal range but with significantly different mean values. The two units of wing development (compartments) differed in their FA response depending on the selective history of each line. We discuss the implication of our results for the use of FA as an indicator of ecological stress.
The relative concentrations of inorganic phosphate and phosphomonoesters (PME) of 18 human cadaveric kidneys stored in Euro-Collins perfusion solution were measured by 31P MR spectroscopy. The signals of intracellular inorganic phosphate (Pjj) and inorganic phosphate contained in the perfusion solution (Pje) were separated by the deconvolution technique. The ratio of the signal intensities of phosphomonoesters and intracellular inorganic phosphate (Pme/Pü) was used as a marker of kidney viability and correlated with kidney function after transplantation. Separation of the Pjj and Pje signals in the measured spectra was successful in 72 % of kidneys. The results of MR analysis satisfactorily agree in 78 % with the post-transplant function of kidneys.
Východiskem článku je situace viability. Ta je analyzována jako sémantický a medicínský koncept a jsou charakterizovány důsledky, které má klinický status extrémně nezralého novorozence (dítěte narozeného na hranici viability) pro etické uvažování a pro rozhodování o odpovídající lékařské péči, když není zohledněno pouze přežití extrémně nezralého novorozence ale rovněž různá úroveň poškození způsobeného lékařským zásahem. Článek se dále zabývá medicínskou nejistotou, jež je typická pro rozhodování o zdravotní péči o extrémně nezralé novorozence. Následně se zaměřuje na nejistotu etickou, která vyplývá z nejistoty medicínské. V závěru pojednání jsou navrženy způsoby, jak postupovat, rozhodovat a konat v situaci etických dilemat zachraňování dětí narozených na samé hranici viability. and The paper departs from viability, analysing viability as semantic and medical concept and characterizing consequences that clinical status of an extremely preterm newborn (neonate born at the edge of viability) has for ethical considerations and decisions about the proper medical care – when not only survival of the extremely preterm neonate but also diverse level of medical harm to the infant are at the stake. Coming from medical uncertainty, typical for the extremely premature newborns, the paper focuses on moral uncertainty caused my medical uncertainty. Finally the paper brings some modi procedendi for ethical dilemmas of saving infants born at the edge of viability.
The aim of the study was to examine the potential impacts of bisphenol A (BPA) and its analogues BPB, BPF, and BPS on mice TM3 Leydig cells, with respect to basal cell viability parameters such as metabolic activity, cell membrane integrity, and lysosomal activity after 48-h exposure. In addition, monitoring of potential bisphenol´s actions included evaluation of ROS production and gap junctional intercellular communication (GJIC) complemented by determination of testosterone secretion. Obtained results revealed significant inhibition in mitochondrial activity started at 10 µg/ml of bisphenols after 48-h exposure. Cell membrane integrity was significantly decreased at 5 µg/ml of BPA and BPF and 10, 25, and 50 µg/ml of BPA and BPS. The lysosomal activity was significantly affected at 10, 25, and 50 µg/ml of applied bisphenols. A significant overproduction of ROS was recorded mainly at 5 and 10 µg/ml of tested compounds. In addition, significant inhibition of GJIC was observed at 5 µg/ml of BPB followed by a progressive decline at higher applied doses. In the case of testosterone production, a significant decline was confirmed at 10, 25 and 50 µg/ml.
Water-borne transmission of the coccidium Cryptosporidium parvum Tyzzer, 1912 is frequently responsible for outbreaks of human cryptosporidiosis. One of the most important was reported in 1993 in Milwaukee in the United States, where 403,000 cases were recorded. The determination of the percentage of oocysts excystated is the first step in evaluating their viability, but it alone is not sufficient. This percentage depended on the conditions of storage and also the presence of oxidant or disinfectent agents in water. The percentage of excystation is not always related to viability. Therefore, determination of the viability of excysted sporozoites by determining their infectivity for enterocytic Caco2 cell lines in culture provides information essential for evaluating the risk of contaminated drinking water.