Microbodies (peroxisomes) in the toad, Bufo marinus. A cytochemical study.
Explore the source record for details and available documents.
Acid Phosphatase↗
Biomedical subjects
F Roels
Publications and source records attributed to F Roels.
[Localization of peroxidase activity in the Artemia salina ovum with the aid of 3,3'-diaminobenzidine, benzidine and pyrogallol].
Explore the source record for details and available documents.
Animals↗
[Binding between spindle fibers and chromosomes during meiosis].
Explore the source record for details and available documents.
Animals↗
Liver plasma membrane: the source of high molecular weight alkaline phosphatase in human serum.
This study presents biochemical, histochemical, morphological and immunological evidence that part of the high molecular weight alkaline phosphatase observed in the serum of patients with liver disease and particularly in cases of intrahepatic cholestasis or focal-, extrahepatic obstruction originates from the liver plasma membrane. The high molecular weight protein alkaline phosphatase complex contains several plasma membrane enzymes and behaves like a plasma membrane fragment after isopycnic density gradient ultracentrifugation in sucrose, cesium chloride and metrizamide. Electron microscopic examination revealed a triple-layered vesicle which retained alkaline phosphatase activity. Incubation of human liver cells with anti-serum against purified high molecular weight multienzyme complex resulted in fixation of antibodies on the plasma membrane as shown by positive plasma membrane fluorescence. These plasma membrane fragments in the serum are not of biliary origin.
Adult↗
Myocardial H2O2 production in the unanaesthetized rat. Influence of fasting, myocardial load and inhibition of superoxide dismutase and monoamine oxidase.
Myocardial H2O2 production was studied by means of the in vivo administration of aminotriazole (AT), which inactivates the catalase-H2O2 complex compound I. Measurements of the residual catalase activity in male and female rats indicate that beta-oxidation of fatty acids in peroxisomes does not contribute in a substantial way to energy production in response to fasting or to an increased myocardial load, despite previous data on peroxisomes in myocardium. Superoxide dismutase (SOD) inhibition by diethyldithiocarbamate demonstrates that SOD participates in the production of H2O2 in physiological conditions. Such a role was not demonstrated for monoamine oxidase through inhibition by phenelzine.
Amitrole↗
In situ end labeling of fragmented DNA in induced ovarian atresia.
Apoptosis is studied in a model of induced follicular atresia in the ovary of Japanese quail (Coturnix coturnix japonica) by in situ end labeling of DNA fragments in granulosa cells using two different techniques (incorporation of labeled nucleotides by DNA polymerase I or terminal deoxynucleotidyl transferase). The most remarkable observation related to apoptosis in this model is the predominant cytoplasmic localization of labeled DNA fragments, while DNA fragmentation appears to be absent from compacted chromatin masses of apoptotic nuclei and apoptotic nuclear fragments. Unstained apoptotic bodies are present adjacent to stained ones, so that their detection rate on hematoxylin + eosin stained sections is better than on the in situ end-labeled sections. This suggests that DNA fragmentation is a late even or not obligatory in apoptotic granulosa cell death. In contrast to similar studies on atretic granulosa in mammalian models, the process of apoptosis is asynchronous in the granulosal epithelium, with a majority of nuclei with normal chromatin configuration remaining negative for DNA fragmentation. Finally it is shown that the techniques used are not specific for apoptosis, as DNA fragmentation in necrotic granulosa cells is detected as well.
Animals↗
In vivo hydrogen peroxide production in rat remnant kidney.
In the rat remnant kidney hydrogen peroxide (H2O2) production is increased when compared to the normal kidney. The activities of the peroxisomal H2O2-producing oxidases, D-amino acid oxidase and acyl-coenzyme A oxidase, and of the extraperoxisomal superoxide dismutase are decreased in renal homogenate. The peroxisomal L-alpha-hydroxyacid oxidase and L-lactate oxidase as well as the peroxisomal H2O2 scavenger catalase preserve their activity. The activity of the cytosolic scavenging system, glutathione peroxidase, is decreased by 40%. A starvation period of 48 h does not produce a measurable increase in H2O2 production in the normal nor in the remnant kidney. On visual inspection, peroxisomal morphology and distribution in the renal tubules are similar in the normal and remnant kidney tissue.
Amitrole↗
Effects of L-proline on phase I and phase II xenobiotic biotransformation capacities of rat and human hepatocytes in long-term collagen gel cultures.
L-Proline supplementation of the medium for collagen gel cultures of hepatocytes has been shown to improve albumin secretion. A study was made as to whether L-proline is also essential for the maintenance of xenobiotic biotransformation capacities in collagen gel sandwich and immobilisation cultures of rat and human hepatocytes. Key phase I (cytochrome P450-dependent monooxygenase [CYP)] and microsomal epoxide hydrase [mEH]) and phase II (glutathione S-transferase [GST]) biotransformation enzyme activities and the secretion of albumin in the culture medium were assessed in the absence and presence of L-proline. CYP and mEH activities were not affected by the addition of L-proline, whereas phase II alpha-Class GST activity of rat hepatocytes in collagen cultures was decreased. Species differences were demonstrated, as human hepatocytes showed a better maintenance of GST activities than their rat counterparts in the presence of L-proline. Albumin secretion, often considered to be a marker for differentiated cell function, does not parallel the biotransformation capacities of the hepatocytes in culture. Additional results demonstrated an L-proline-mediated enhancement of the proliferation rate of contaminating stellate cells in conventional monolayer culture. Transdifferentiation of stellate cells to proliferating myofibroblasts, along with an increased albumin secretion and collagen synthesis, are characteristic of fibrotic liver. Since the last two phenomena have been observed in L-proline-supplemented collagen gel cultures, it can be concluded that when stable collagen gel cultures of rat hepatocytes are needed for long-term pharmacotoxicological studies, it is preferable to use an L-proline-free culture medium. Further studies on medium optimisation are required for hepatocytes from species other than rat.
Adult↗
Hepatic ultrastructure in congenital total lipodystrophy with special reference to peroxisomes.
The liver of an 8-year-old boy with congenital total lipodystrophy was investigated by means of catalase cytochemistry and morphometry. Comparison was made with eight human control livers. Light microscopy revealed cirrhosis and steatosis. Ultrastructural changes included lipid droplets with lamellae in the periphery, cup-shaped mitochondria, and nuclear pseudoinclusions. Peroxisomes were significantly increased in number but were not enlarged; they displayed various shapes and showed a moderate heterogeneity in catalase activity. A correlation between increased lipids and peroxisomal proliferation is suggested.
Child↗
[Zellweger syndrome. Reports on two new cases].
INTRODUCTION: Zellweger syndrome, or cerebrohepatorenal syndrome, is the most serious form of the peroxisomal diseases. Clinically, it is characterised by the association between craniofacial dysmorphia and neurological disorders, together with the involvement of other organs. To perform a diagnosis it is advisable to follow a procedural protocol that begins with the quantification of very long chain fatty acids in an assortment of samples (serum, fibroblasts and mononucleate cells), plasmalogens, branched chain fatty acids in serum (phytanic and pristanic acids), polyunsaturated acids and bile salts. Studies conducted with neuroimaging, renal echography, skeletal X rays and biopsy samples of different tissues will provide us with information about the involvement of different organs. CASE REPORTS: The first case we report is that of a male who, from birth, presented a distinctive phenotype with very large fontanelles, important hypotonia, epileptic seizures and acute organic disorders that led to death at the age of seven weeks. The second case involved a new born male suffering from prenatally diagnosed heart disease and craniofacial dysmorphia with hypotonia. CONCLUSIONS: Given the scarce survival rate of patients, early diagnosis of this type of disease is crucial and, although complex, a study must be conducted so as to be able to provide genetic counselling.
Cerebral Cortex↗
Rapid effects of dietary fish oil on peroxisomes in mouse liver.
We investigated hepatic catalase activity, and morphologic and morphometric alterations of hepatocellular peroxisomes after catalase cytochemistry, in mice given a diet supplemented with 10% Beromegan, a commercial fish oil preparation, for up to three days. Fish oil is rich in docosahexaenoic acid (C22:6 (n-3)) and in eicosapentaenoic acid (20:5 (n-3)). Hepatic catalase activity showed a gradual increase in mice fed this diet, being significantly increased (136 +/- 10 UB/g liver) after three days when compared top controls (85 +/- 11 UB/g liver). Light microscopy indicated an increase in peroxisomal staining and peroxisomal proliferation. The latter observation was confirmed by ultrastructural morphometry: number, volume density and surface density of the peroxisomes were more than doubled after a three day diet containing fish oil. Peroxisomal size was not changed. These alterations are suggestive for an increased peroxisomal metabolism induced by a diet rich in poly-unsaturated fatty acids.
Animals↗