Sublethal physiological effects of chlorinated paraffins on the flounder, Platichthys flesus L.

Exposure of flounder, Platichthys flesus L., to two different chlorinated paraffin preparations, Witachlor 149 and Hülz 70C, caused sublethal effects on hematology and intermediary metabolism, together with changed activities in xenobiotic and steroid metabolizing enzymes, especially in female fish. The changes observed must be considered important and urge for further studies as the chlorinated paraffins are used in steadily increasing amounts and constitute a possible ecological threat.     

Effect of different degrees of brain ischemia and tissue lactic acidosis on the short-term recovery of neurophysiologic and metabolic variables

The recovery of the EEG and somatosensory evoked responses (SER) as compared with recovery of the cerebral energy state was studied in rats during recirculation following different degrees of brain ischemia with varying tissue lactic acidosis. Reversible complete and incomplete ischemia was induced either by increasing the intracranial pressure (compression ischemia) or by carotid artery clamping combined with arterial hypotension. In incomplete ischemia the degree of tissue lactic acidosis was varied by manipulations of blood and brain glucose levels. Animals with an increase in brain lactate to about 25 mumol X g-1 (whole brain wet weight) during ischemia showed persistent failure of both cerebral energy metabolism and neurophysiologic restitution during the recirculation phase; if less than 20 mumol X g-1 metabolic recovery was almost complete. Despite a similar restitution of tissue energy metabolism in these animals, neurophysiologic recovery was inversely proportional to brain lactate concentrations during ischemia. At similar levels of ischemic tissue lactic acidosis, and despite a similar recovery of cortical energy state, the neurophysiologic restitution was clearly inferior after complete ischemia to that following incomplete ischemia. Three conclusions were drawn: (i) neurophysiologic variables were more sensitive indicators of postischemic persistent cerebral dysfunction than the cerebral energy state; (ii) the degree to which lactate accumulated in the ischemic brain influenced neurophysiologic restitution even if concentrations critical for metabolic recovery were not attained; and (iii) incomplete ischemia was less harmful than complete ischemia provided that tissue lactic acidosis was not excessive.     

The effects of lead on δ-aminolevulinic acid dehydratase activity,growth, hemoglobin content,and reproduction in Daphnia magna

The effects of continuous exposure to lead for various periods and recovery in clean water on δ-aminolevulinic acid dehydratase (ALA-D) activity, hemoglobin content, growth, and reproduction were studied in Daphnia magna. Steady-state inhibition of ALA-D activity was reached within 2 days in 16, 64, and 256 μg Pb liter^?1, but restoration in clean water was prolonged in relation to previous exposure. In spite of the inhibition of ALA-D activity hemoglobin content increased after 2 days in 16 and 24 μg Pb liter^?1. Furthermore, hemoglobin content in previously exposed animals increased during recovery in clean water. Maximum hemoglobin content (2.9 times control value) was found after 2 days recovery of animals exposed to 64 μg Pb liter^?1. These findings suggest that some enzyme(s) other than ALA-D in the biosynthetic pathway of hemoglobin formation is (are) more sensitive to lead. Growth, in contrast to reproduction, was stimulated by low concentrations of lead (<64 μg Pb liter^?1), although in 256 μg Pb liter^?1 growth was also significantly impaired. After 19 days the 16 and 50% reproductive impairment concentrations were ?1 and 10 μg Pb liter^?1, respectively.     

The effect of cadmium on the hematology and on the activity of delta-aminolevulinic acid dehydratase (ALA-D) in blood and hematopoietic tissues of the flounder, Pleuronectes flesus L.

Flounders (Pleuronectes flesus) were exposed to sublethal levels of cadmium (5, 50, and 500 micrograms of Cd2+/liter) for periods of 4 and 9 weeks, and the hematological response as well as the effect on the activity of delta-aminolevulinic acid dehydratase (ALA-D) in blood and blood-forming tissues were investigated. Significant reductions of hematocrit, hemoglobin, and red blood cell count were found in the cadmium-exposed fish. This anemic response was apparent even in flounders exposed to the lowest cadmium concentration, approximately corresponding to 1/4000 of the 96-hr LC50 value. The anemia was accompanied by a significant increase of the ALA-D activity in renal tissues. This indicates a compensatory stimulation of the introductory steps of the hemoglobin biosynthesis. However, the formation of hemoglobin does not seem to be accomplished, which might be due to a disturbed iron metabolism. The cadmium exposure also resulted in a significant increase of the number of lymphocytes, indicating an action on the immunological defense of the fish.     

Implementation of a new rapid tissue processing method--advantages and challenges

Conventional tissue processing of histologic specimens has been carried out in the same manner for many years. It is a time-consuming process involving batch production, resulting in a 1-day delay of the diagnosis. Microwave-assisted tissue processing enables a continuous high flow of histologic specimens through the processor with a processing time of as low as 1h. In this article, we present the effects of the automated microwave-assisted tissue processor on the histomorphologic quality and the turnaround time (TAT) for histopathology reports. We present a blind comparative study regarding the histomorphologic quality of microwave-processed and conventionally processed tissue samples. A total of 333 specimens were included. The microwave-assisted processing method showed a histomorphologic quality comparable to the conventional method for a number of tissue types, including skin and specimens from the gastrointestinal, urogenital, and female genital tract. We studied the TAT for all histologic specimens received in a period of six consecutive weeks in 2006 and 2007, respectively. We found a positive impact on TATs after introducing microwave-assisted processing in the laboratory. Turnaround times, in general, were improved, and same-day-reporting, in particular, showed an increase from 0% to 15%.     

Mesenchymal stem cell therapy of acute thermal burns: A systematic review of the effect on inflammation and wound healing

AimMesenchymal stem cell (MSC) therapies are emerging as a promising strategy to promote tissue repair, and may extend their utility to burn care. This comprehensive review of the extant literature, evaluated all in vivo studies, to elucidate the potential protective and therapeutic effect of MSCs in acute thermal skin burns.MethodsPubMed was systematically searched, according to PRISMA guidelines, and all relevant preclinical and clinical studies were included according to pre-specified eligibility criteria.ResultsForty-two studies were included in a qualitative synthesis, of which three were human and 39 were animal studies. The preclinical studies showed that MSCs can significantly reduce inflammation, burn wound progression and accelerate healing rate of acute burns. The underlying mechanisms are complex and not fully understood but paracrine modulators, such as immunomodulatory, antioxidative and trophic factors, seem to play important roles. Allogeneic MSC therapy has proved feasible in humans, and could allow for prompt treatment of acute burns in a clinical setting.ConclusionMSC therapy show positive results, regarding improved burn wound healing and immunologic response. However, most findings are based on small animal studies. Randomized clinical trials are warranted to investigate the regenerative effects in human burns before translating the findings into clinical practice.