Melatonin Induces Apoptosis and Modulates Cyclin Expression and MAPK Phosphorylation in Pancreatic Stellate Cells Subjected to Hypoxia.

In certain diseases of the pancreas, pancreatic stellate cells form an important part of fibrosis and are critical for the development of cancer cells. A hypoxic condition develops within the tumor, to which pancreatic stellate cells adapt and are able to proliferate. The consequence is the growth of the tumor.

Melatonin Modulates the Antioxidant Defenses and the Expression of Proinflammatory Mediators in Pancreatic Stellate Cells Subjected to Hypoxia.

Pancreatic stellate cells (PSC) play a major role in the formation of fibrotic tissue in pancreatic tumors. On its side, melatonin is a putative therapeutic agent for pancreatic cancer and inflammation. In this work, the actions of melatonin on PSC subjected to hypoxia were evaluated.

Pancreatic stellate cells exhibit adaptation to oxidative stress evoked by hypoxia.

Background Information: Pancreatic stellate cells play a key role in the fibrosis that develops in diseases such as pancreatic cancer. In the growing tumour, a hypoxia condition develops under which cancer cells are able to proliferate. The growth of fibrotic tissue contributes to hypoxia.

The melatonin receptor antagonist luzindole induces the activation of cellular stress responses and decreases viability of rat pancreatic stellate cells.

In this study, we have examined the effects of luzindole, a melatonin receptor-antagonist, on cultured pancreatic stellate cells. Intracellular free-Ca concentration, production of reactive oxygen species (ROS), activation of mitogen-activated protein kinases (MAPK), endoplasmic reticulum stress and cell viability were analyzed. Stimulation of cells with the luzindole (1, 5, 10 and 50 μm) evoked a slow and progressive increase in intracellular free Ca ([Ca ] ) towards a plateau.

Melatonin modulates proliferation of pancreatic stellate cells through caspase-3 activation and changes in cyclin A and D expression.

In this study, the effects of melatonin (1 μM-1 mM) on pancreatic stellate cells (PSC) have been examined. Cell viability and proliferation, caspase-3 activation, and the expression of cyclin A and cyclin D were analyzed. Our results show that melatonin decreased PSC viability in a time- and concentration-dependent manner.

Melatonin modulates red-ox state and decreases viability of rat pancreatic stellate cells.

In this work we have studied the effects of pharmacological concentrations of melatonin (1 µM-1 mM) on pancreatic stellate cells (PSC). Cell viability was analyzed by AlamarBlue test. Production of reactive oxygen species (ROS) was monitored following CM-HDCFDA and MitoSOX Red-derived fluorescence.

The melatonin receptor antagonist luzindole induces Ca mobilization, reactive oxygen species generation and impairs trypsin secretion in mouse pancreatic acinar cells.

Background: In this work we studied the effects of the melatonin receptor-antagonist luzindole (1 μM-50 μM) on isolated mouse pancreatic acinar cells.

Methods: Changes in intracellular free-Ca concentration, reactive oxygen species production and trypsin secretion were analyzed.

Results: Luzindole induced increases in [Ca] that diminished CCK-8 induced Ca mobilization, compared with that observed when CCK-8 was applied alone.

Melatonin induces reactive oxygen species generation and changes in glutathione levels and reduces viability in human pancreatic stellate cells.

In this study, the effects of pharmacological concentrations of melatonin (1 μM-1 mM) on human pancreatic stellate cells (HPSCs) have been examined. Cell type-specific markers and expression of melatonin receptors were analyzed by western blot analysis. Changes in intracellular free Ca concentration were followed by fluorimetric analysis of fura-2-loaded cells.

Effect of long-term exposure to simazine on histopathology, hematological, and biochemical parameters in Cyprinus carpio.

We investigated if residues of simazine in the natural waters would cause histological, hematological, and biochemical alterations in carps from contaminated areas in Badajoz (Spain). Some necrotic foci in kidney and liver, hepatitis, and hepatic steatosis were detected. No changes on measured hematological and biochemical parameters between fish from reference and contaminated ponds were observed.

Histomorphogenesis and immunohistochemical study of the bovine pineal gland (Bos taurus) during prenatal development (160 days of gestation to birth).

The ontogenesis of the pineal gland of 20 bovine embryos (Bos taurus) has been analysed from 160 days of gestation to birth by means of optical microscopy and immunohistochemical techniques. For this study, the specimens were grouped into two stage in accordance with the most relevant histological characteristics: Stage 1 (160 to 200 days of prenatal development) and Stage 2 (220 days of prenatal development to birth). At 160 days of gestation some rounded structures with a central lumen, which we refer to as glandular rosettes, begin differentiation from the epithelium of the pineal recess, experiencing an extraordinary increase in number and size at 200 days of intrauterine life.

Embryonic development of the bovine pineal gland (Bos taurus) during prenatal life (30 to 135 days of gestation).

The ontogenesis of the pineal gland of 30 bovine embryos (Bos taurus) has been analysed from 30 until 135 days of gestation by means of optical microscopy and immunohistochemical techniques. For this study, the specimens were grouped into three stages in accordance with the most relevant histological characteristics: Stage 1 (30 to 64 days of prenatal development); Stage 2 (70 to 90 days) and Stage 3 (106 to 135 days). In the cow, it is from 30 days of gestation that the first glandular outline becomes differentiated from the diencephalic ependyma of the third ventricle.

Lymphoma in a rabbit: histopathological and immunohistochemical findings.

Lymphoma is a very common lymphoid neoplasm in domestic animals, but few naturally occurring cases have been reported in rabbits. It presents at different sites within rabbits and, although the macroscopic pattern tends to be similar, different cell populations may be involved. This report describes a case of spontaneous lymphoma ocurring in a two-and-a-half-year-old pet Dutch dwarf rabbit.

Lesions induced by 2,4-D and chlorpyrifos in tench (Tinca tinca L.): implication in toxicity studies.

This study was undertaken to demonstrate the toxicity of two pesticides, chlorpyrifos (O,O-diethyl 0-3,5,6-trichloro-2-pyridyl phosphorothioate) and 2,4-D (Dichlorophenoxyacetic acid) to tench (Tinca tinca Linnaeus). Pathological samples of damaged tench kidney showing lesions were taken for statistical analysis in order to quantify different parameters. Analysis revealed differences in the action and/or action time of the two pesticides.

Acute 2,4-D poisoning in tench (Tinca tinca L.): lesions in the hematopoietic portion of the kidney.

An experimental model was designed to study the acute lesions caused by a continuous exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) disolved in water (400 mg/L) in hematopoietic kidney tissue in tench (Tinca tinca L). Fifty fish were used in this study, 15 for calculating LC50 and 35 were euthanized 1, 2, 5, 8, and 12 days postpoisoning (five treated and two controls each time). Tissue samples, fixed in 5% glutaraldehyde in 0.

Trenbolone acetate induced changes in the genital tract of male pigs.

Eleven entire and twelve castrated male pigs were implanted with trenbolone acetate and the effects of the treatment on genital tract macro- and microscopical modifications were evaluated and compared to non-implanted animals. In entire male pigs a reduction of testicular weight and size was observed as a consequence of the treatment (< 0.001), but no important modifications were found in bulbourethral gland and seminal vesicles macroscopically.

Experimental reproduction of acute pneumonic pasteurellosis in rabbits.

A histomorphometric and physiopathological study was made of the lung parenchyma of Belgian White SPF rabbits infected experimentally with Pasteurella multocida type A. Symptoms observed were characteristic of the acute respiratory syndrome. Mean serum cortisol concentration and rectal temperature increased in all experimental groups.

Adenocarcinoma of the ethmoid olfactory mucosa: a histopathological and ultrastructural study with evidence of virus-like particles.

A histopathological, morphometric and ultrastructural study was made of enzootic nasal neoplasia in a group of 25 Verata goats. A nasal adenocarcinoma was diagnosed. The neoplasm contained two clearly defined zones, one cystic and the other compact.

Morphometric, structural, and ultrastructural studies of tench (Tinca tinca L.) hepatocytes after copper sulfate administration.

A structural, ultrastructural, and morphometric study was made of the liver parenchyma of 12 adult tench (Tinca tinca, L.) subjected to acute experimental copper sulfate poisoning. The lesions observed were characterized by the accumulation in the cytoplasm of large amounts of hemoglobinemic pigment produced by intense hemolysis, initially in Kupffer cells and by the last stage of the experiment in hepatocytes.

Experimental lead nitrate poisoning: microscopic and ultrastructural study of the gills of tench (Tinca tinca, L.).

A microscopic, ultrastructural, and morphometric study was made of the gills of tench (Tinca tinca, L.) subjected to acute experimental lead nitrate poisoning. Twenty-one adult tench were subjected to poisoning and a further 22 were used as controls.

Structural and ultrastructural differentiation of cell types in the gills of the tench (Tinca tinca, L.).

This study used 22 tench of 25-30 cm in length and weighing roughly 200 g. After sacrifice, the gill arch was extracted and fixed in 5% glutaraldehyde for structural, ultrastructural and morphometrical study. Tench gills consist of primary lamellae which are perpendicular to numerous secondary lamellae in which the respiratory barrier is located.

Glomerular filtration barrier in experimental endotoxin shock: a histopathological and physiopathological study.

In the present work a morphopathological study is carried out of the glomerular filtration barrier in 20 Large-White pigs weighing 20 kg, subjected to experimental intravenous inoculations of endotoxin from Salmonella enteritidis. The study is completed with the determination of protein plasmatic levels, through urine test with the determination of pH, density, proteins, glucose, ketone body levels and urinary sediment. The histopathological and physiopathological results reveal alterations at the level of the filtration barrier with quantitative differences between the different experimental groups.

A histopathological and morphometrical study of femur head cartilage in Wistar rats treated with prednisolone.

An analysis was made of histopathological developments in femur head cartilage in a group of Wistar rats receiving a daily intra-muscular injection of 2.5 mg prednisolone. This group was divided into four experimental batches, each consisting of 6 rats.