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Biomedical subjects

T C Iancu

Publications and source records attributed to T C Iancu.

At least 19 recordsLinked to original sources

The hypotransferrinaemic mouse: ultrastructural and laser microprobe analysis observations.

Homozygote hypotransferrinaemic mice (hpx/hpx) have cytopathological features similar to those of human congenital atransferrinaemia, genetic haemochromatosis, and neonatal haemochromatosis. These conditions all have in common high levels of cytotoxic non-transferrin-bound serum iron. This study describes the ultrastructural features of iron overload in liver, pancreas, heart, and small intestine of 2- and 12-month-old hypotransferrinaemic mice. Electron microscopic studies of unstained sections showed early parenchymal cell siderosis, with accumulation of numerous ferritin particles and clusters in the cytosol, as well as ferritin and haemosiderin in lysosomes (siderosomes). In the 12-month-old animals, iron was also found in Kupffer cells and macrophages in other tissues. In addition, there were conspicuous iron-containing compounds in the bile canaliculi, and marked iron deposition in the pancreas and heart. Laser microprobe mass analysis (LAMMA) enabled localization and relative quantitation of iron deposition in subcellular compartments providing in situ documentation of iron accumulation in siderosomes and contributed in assessing total cytosolic iron in various cell types. Moreover, it demonstrated the importance and magnitude of the biliary route for iron excretion in these animals.

Animals

A new type of peroxisomal disorder with variable expression in liver and fibroblasts.

We describe two siblings, presently 5 and 9 years of age, who had neurodegenerative symptoms after the first year of life. Although they lacked clinical characteristics of a peroxisomal disorder, they had elevated levels of plasma very long chain fatty acids, pipecolic and phytanic acids, and abnormal bile acid intermediates, which suggested a generalized peroxisome deficiency disorder. Immunocytochemical study and electron microscopy of the liver disclosed absence of peroxisomes in approximately 90% of hepatocytes. However, the remaining 10% of the hepatocytes had numerous normal-looking peroxisomes containing catalase activity and catalase antigen. Alanine glyoxylate aminotransferase and the peroxisomal beta-oxidation enzymes acyl-coenzyme A oxidase and 3-ketoacyl coenzyme A thiolase were also present in the organelles. Both cell types were grouped in clusters. In contrast to most of the liver cells, fibroblasts cultured from skin biopsy specimens had normal peroxisomal functions. Thus this defect in peroxisome biogenesis is characterized by variable expression in different tissues (liver vs fibroblasts), as well as within individual cells in the same tissue (liver mosaicism). Awareness of the heterogeneity in tissue expression of peroxisomal disorders could be of critical importance in prenatal diagnosis.

Child

Immunological diagnosis of childhood coeliac disease: comparison between antigliadin, antireticulin and antiendomysial antibodies.

The immunological markers proposed to supplement intestinal biopsy for the diagnosis of coeliac disease are antigliadin, antireticulin and antiendomysial antibodies. These antibodies have been studied separately or compared as pairs, but no prospective comparison of all three antibodies in childhood coeliac disease exists. Thirty-four confirmed coeliacs were compared with nine non-coeliacs with pathological small intestines, and 32 children with a normal intestinal histology. Sera were examined for IgG- and IgA-antigliadin antibodies (AGA) by ELISA, and for IgA-antireticulin antibodies (ARA) and IgA endomysial antibodies (EMA) by indirect immunofluorescence. In active coeliac disease, IgA-EMA was the most sensitive (97%), while IgA-AGA the least sensitive antibody (52%). The specificity of IgA-AGA, IgG-AGA, IgA-ARA, IgA-EMA was 95%, 92%, 100% and 98%, respectively. Positive predicted values of ARA and EMA were comparable (97-100%), while EMA had the highest negative predicted value (98%). Compared with IgG-AGA, IgA-EMA titres better reflected variations in dietary gluten, and correlated best with intestinal pathology. Compared with AGA and ARA sensitivity, specificity and predictive values, EMA is the most reliable serological marker for the diagnosis of coeliac disease. It reflects dietary changes in gluten and correlates best with intestinal histopathology. Therefore, it should be considered the best of the three serological tests available for childhood coeliac disease.

Adolescent

Ferritin and hemosiderin in pathological tissues.

The biological importance of iron for most living cells has been under increasing attention during recent years. In addition to iron deficiency, iron overload has been recognized as a significant metabolic abnormality with potentially damaging consequences. The iron-storing compounds ferritin and hemosiderin have the unique quality of being ultrastructurally recognizable because of the electron-density of the iron concentrated within their particles. In this review, the electron microscopic features of iron overload are discussed, as found in various subcellular compartments and different types of cells and tissues. Defensive mechanisms against iron overload are exhibited by most cell lines and include: (1) the capacity of synthesis of the protein apoferritin by most cells whenever the concentration of ambient iron increases, (2) the capacity to bind toxic inorganic iron within the hollow shell of apoferritin; the transfer of the assembled iron-rich ferritin molecules into siderosomes and (3) the capability of further iron segregation within siderosomes by degradation of ferritin to hemosiderin. The study provides examples of cytosiderosis in different types of cells and tissues, as well as iron-related ultrastructural pathological changes.

Animals

Is eye cosmetic a source of lead poisoning?

Kohl is a lead-containing eye cosmetic applied to many infants in Israel and in other countries in the Middle East. Seven samples of kohl used in our region contained 17.3%-79.5% lead. We assessed 24 kohl users and 30 non-kohl users, aged 6-16 months, for blood lead, zinc protoporphyrin, hemoglobin, mean corpuscular volume (MCV), serum iron and calcium. Blood lead levels were significantly higher in the infants to whom kohl was applied (11.2 vs. 4.3 micrograms/dl, P less than 0.001) and were greater than 20 micrograms/dl in three of them. In the non-kohl users, blood lead levels were significantly higher in infants whose mothers used kohl (5.2 vs. 2.8 micrograms/dl, P less than 0.02). No significant differences were found in the other parameters. The kohl-using infants were significantly shorter at 3-5 weeks of age (P less than 0.005) but not at the time of the study. No significant differences were found in weight and head circumference at birth or at the time of the study between kohl-using infants and controls. Regression analysis showed that among the analyzed variables the infant's blood lead level was related only to the use of kohl. We conclude that application of kohl to the infant's or mother's eyes is associated with a significant increase in the infant's blood lead levels and in the minority of cases with asymptomatic lead poisoning.

Birth Weight

Deferoxamine-induced iron mobilization and redistribution of myocardial iron in cultured rat heart cells: studies of the chelatable iron pool by electron microscopy and Mössbauer spectroscopy.

Iron mobilization by deferoxamine from iron-loaded rat heart cells in culture was studied by electron microscopy and Mössbauer spectroscopy to identify the chelatable iron pool. Studies in which iron 59 was used have shown a diminishing response to deferoxamine with increasing time intervals, which suggests a gradual transit from a more available to a less available storage iron compartment. Mössbauer spectroscopy showed that practically all iron mobilized by deferoxamine was derived from the small (less than 3.0 nm) recently acquired iron particles, which supports the "last-in, first-out" principle. Quantitation of cytosolic ferritin iron particles has shown a highly reproducible increase in cytosolic ferritin iron after deferoxamine treatment. This intracellular redistribution of iron stores is explained either by a reduced transfer of cytosolic ferritin into siderosomes or, more likely, by increased mobilization of membrane-bound iron deposits from insoluble polynuclear iron complexes in siderosomes and their subsequent incorporation into cytosolic ferritin. Thus the protective effect of deferoxamine on iron-loaded heart cells may be twofold: (1) net removal of excess iron by the formation of a stable complex of iron with deferoxamine and its secretion into the extracellular environment and (2) a shift of solubilized iron from membrane-bound deposits into the cytosol where iron is detoxified by its incorporation into the hollow shell of the ferritin protein.

Animals

Pitfall in diagnosis of Crohn's disease in a cystic fibrosis patient.

Cystic fibrosis (CF) and Crohn's disease may both present as failure to thrive and recurrent intestinal obstruction. Proper treatment and adequate nutrition may reverse these manifestations and improve the patient's quality of life. We describe a girl with CF who, despite appropriate management, failed to grow and had several episodes of bowel obstruction. After the additional diagnosis of Crohn's disease was reached, the patient improved on antiinflammatory and nutritional therapy. This patient illustrates the pitfall in the diagnosis of Crohn's disease in a CF patient due to the clinical overlap between the two conditions. We suggest that therapeutic failure in a chronic disease justifies additional diagnostic efforts resulting in a completion of diagnosis and significant changes in management.

Child

Prolactin and cortisol levels in various paroxysmal disorders in childhood.

The hormonal response of the anterior pituitary to various epileptic and nonepileptic events in children was studied. Postictal serum prolactin and cortisol levels were measured in 17 children with epilepsy, 23 with febrile seizures, and 10 with syncope or breath-holding spells. The levels were compared with those of 30 children with nonspecific fever, and 23 afebrile children served as control subjects. Significantly higher (P less than .01) prolactin levels (26.5 +/- 3.3 ng/mL, mean +/- SEM) were found in the epileptic group, compared with levels in children with febrile seizures (13.2 +/- 1.0 ng/mL), fever (11.2 +/- 0.9 ng/mL), syncope (7.3 +/- 0.9 ng/mL), and the control group (7.9 +/- 0.6 ng/mL). In contrast, serum cortisol levels were nonspecifically elevated in the epileptics and patients with febrile seizures or fever only. These findings suggest that elevated prolactin levels may be found after epileptic seizures and much less after febrile seizures, but not after breath-holding spells or syncopal events. Cortisol secretion appears to be nonselectively triggered by all stressful events, such as epileptic and febrile seizures, and fever. Elevated prolactin levels (greater than 15 ng/mL) associated with seizures may help in differentiating epileptic from febrile seizures or syncope.

Child

Iron, transferrin, and ferritin in cerebrospinal fluid of children.

We measured iron, ferritin, and transferrin in cerebrospinal fluid (CSF) of pediatric patients. Because the concentrations of iron and iron-binding proteins in CSF in these samples were lower than those ordinarily measured in older subjects, we had to modify the lower limit of detection of the methods used. The concentrations of these three analytes in patients with viral meningitis were higher than those in healthy infants and children.

Child

Krabbe disease in Israel.

Over a period of 15 years, 18 infants affected with Krabbe disease were diagnosed in Israel. None of the patients were Jews. Six were Druze from a large kindred in which a very high incidence of the disease was previously reported. The 12 other patients were Moslem Arabs; 7 were from two adjacent villages and most of them were found to be related, originating from a large kindred in which the incidence of the disease is 1/130 live births. Three other patients were from a third large kindred that also had a high incidence of Krabbe disease. Israel's population includes communities in which a high incidence of lysosomal diseases has been found. The incidence of these diseases in Israel may be reduced by delineating the populations at risk. With respect to Krabbe disease, as reported here, the tests for heterozygote detection are not sufficiently accurate for a screening of the populations at risk. Prevention is possible only by prenatal diagnosis in the families at risk.

Female

Ultrastructural changes in the pancreas of carbonyl iron-fed rats.

Diabetes mellitus is found with increased frequency in patients with both primary and secondary hemochromatosis. In these conditions, the pancreas shows fibrosis and iron overload of acini, interstitium, and islet B cells. Previous morphological studies have only described changes found in advanced stages of disease, while abnormalities of the initial stage of iron overload have, as yet, not been reported. Rats fed a carbonyl iron-supplemented diet for 4-15 months showed storage iron deposition (ferritin and hemosiderin) in many organs, in a pattern similar to primary human hemochromatosis. Electron microscopic examination of the pancreas showed ferritin particles segregated in lysosomes of acinar cells, as well as diffuse cytosiderosis of macrophages in the interstitial septa. In the islets, iron deposits were discrete and only in B cells. In the absence of electron-microscopic studies of incipient pancreatic cytosiderosis in human subjects, the present experimental animal study may contribute to a better understanding of the pathway leading to the extensive lesions found in the advanced stages of the human iron overloading diseases.

Animals

Autonomic seizures in an infant: unusual cutaneous and cardiac manifestations.

An eight-month-old infant developed autonomic seizures, manifested by skin reaction (harlequin-like syndrome) and paroxysmal bradycardia. Interictal EEG showed multifocal spikes, 24-hour EEG/ECG monitoring disclosed episodes of cerebral decremental response associated with cardiac nodal rhythm. Head CT and other laboratory tests were normal. Despite excellent seizure control with carbamazepine, the child has moderate psychomotor retardation.

Anticonvulsants

Biological and ultrastructural aspects of iron overload: an overview.

The morphologic aspects of iron overload have been studied in human subjects, mammals, and birds with spontaneous overload, in a variety of experimental animals, and also in cell cultures. Reviewed here are the contributions of electron microscopy to the understanding of the iron-loading process, as reported during the last 12 years. The electron-density of ferrihydrite cores located within the protein shell of the ferritin molecule enabled its identification within either cytosol or lysosomes (siderosomes) of iron-exposed cells. The process of (holo)ferritin assembly, its transfer into siderosomes, and its degradation to hemosiderin can be followed in various cells. Siderosomes display cell-line-specific ultrastructural features, and different cell types show varying iron-segregating capacity. The study of experimental animals and cultured cells show that an iron-rich milieu may be damaging, probably through iron-catalyzed lipid peroxidation. Recent ultrastructural studies stress the value of describing initial alterations as opposed to the irrelevant end-stage findings. Further efforts should be directed toward elucidating the origin of iron in neonatal hemochromatosis, the role of iron in infection and neoplasia, and the nature and role of brain iron.

Absorption

Functional immunoregulatory T-cell abnormalities in cystic fibrosis patients.

The role of B cells and regulatory T cells in the reduced in vitro IgG synthesis of cystic fibrosis (CF) patients was studied. Intact proportion, proliferation, and differentiation of B cells and reduced suppressor and helper T-cell function were found. To explore the T-cell defects further, CF sera or supernatant derived from Pseudomonas aeruginosa cultures (PA supernatant) was added to the relevant T helper- and suppressor-cell assays. Both CF sera derived from PA-positive patients and PA supernatant interfered with the appearance of interleukin 2 (IL-2) receptors and with the functional enhancement caused by exogenously added IL-2. PA-negative CF patients, however, also had functional T-cell defects and inhibitory sera, but these sera did not affect IL-2 pathways. Thus different serum factors and intrinsic T-cell defects in CF patients are suggested.

Adolescent