Age-related changes in the cell kinetics of rat foot epidermis.

The durations of the cell cycle and its component phases have been determined for the basal layer of the epidermis of the skin from the upper surface of the hind foot of the rat using single pulse [3H]-thymidine labelling and the percent labelled mitosis (PLM) technique. Rats of three age groups were used, namely 7, 14 and 52 weeks. The duration of DNA synthesis (Ts) and the G2 plus M phase (TG2 + M) were comparable in 7-week and 52-week-old rats (P greater than 0.

[Fc-receptor mediated immune complex clearance function of the mononuclear phagocyte system in systemic lupus erythematosus].

Fc receptor mediated immune complex clearance function was measured in patients with systemic lupus erythematosus. Autologous erythrocytes were sensitized by human IgG anti-Rh(D) and used as immune complex model. An impaired Fc receptor function was demonstrable in 20 of 25 investigated patients.

Substructural alterations of liver parenchymal cells induced by xenobiotics.

Xenobiotic-induced basic ultrastructural reactions of liver parenchymal cells as visualized with the basic method in ultrastructural research, the transmission electron microscopy, are described. There exists no "average hepatocyte", but even the normal liver is composed of a heterogeneous population of parenchymal cells revealing distinct ultrastructural and functional differences according to the intra-acinar location, circadian rhythms or metabolic and physiologic conditions. This liver cell heterogeneity is, as a rule, very much increased after acute or chronic exposure of the liver to any xenobiotic compound.

[Indications for radiotherapy of rectal cancer].

Surgery and radiotherapy complete each other in local control of suffering from rectal carcinoma. A radiotherapeutic effect on tumor is secured often. The adjuvant radiotherapy is the most interesting indication, though the most controversial as present too.

Biochemical and ultrastructural studies on the effect of verapamil on formation and secretion of lipoproteins in rat hepatocyte suspensions.

The effect of the calcium channel blocker verapamil on structure, formation and secretion of very-low-density lipoproteins (VLDL) from rat hepatocytes in suspension was examined. After 30 min incubation at a verapamil dose of 200 microM neither free fatty acid (FFA) uptake nor triglyceride (TG) and phospholipid (PL) secretion into the incubation medium were significantly changed. After 90 min incubation the TG secretion was inhibited by about 60%, whereas the PL output was only insignificantly lowered, indicating the secretion of abnormally composed lipoprotein particles.

Isolation and characterization of parenchymal cells from experimentally induced macronodular rat liver cirrhosis.

Hepatocytes were isolated from thioacetamide (TAA)-induced macronodular cirrhotic rat livers by a collagenase perfusion method. In the content of cellular metabolites, fatty acid uptake and lipid secretion there were no substantial differences compared with cells isolated from micronodular cirrhosis described previously. In contrast to isolated hepatocytes from normal livers those from macronodular cirrhosis had a lowered cellular content of triglycerides, phospholipids and cholesterol but not of cholesterol esters and free fatty acids.

Glutathione synthesis and export in experimental liver cirrhosis induced by thioacetamide: relations to ultrastructural changes.

Micro-and macronodular experimental liver cirrhosis was induced in female rats by administration of 0.03% thioacetamide (TAA) in drinking water for 3 or 6 months, respectively. The glutathione (GSH) status (content, synthesis, export) and ultrastructural changes of liver were investigated 14 d after withdrawal of TAA.

Hepatic actions of levonorgestrel: correlations between biochemical and morphological findings.

The influence of the synthetic sexual steroid levonorgestrel (LN) on rat liver in various doses and at different structural levels was investigated. A slight reactive hepatosis was found by histological examination after administration of LN in a dose of 10 mg per kg body wt. The same dose caused exclusively distinct lesions of the mitochondria, however, only in centrilobular parenchymal cells, whereas in the periportal hepatocytes only the lipid droplet content appears somewhat elevated.

Evaluating polyimides as lightguide materials.

Lightguides were fabricated from three commercial polyimides of which one contains one and the others contain two hexafluoroisopropylidene (6F) groups. The latter are isomers using either the para or the meta isomer of the same diamine. As the number of 6F groups increases the optical losses of the corresponding lightguides decreases.

Receptor-mediated uptake of homologous low-density lipoproteins by isolated liver parenchymal cells of fetal rats.

The binding and uptake of gold-labeled homologous, apolipoprotein E-free low-density lipoproteins (LDL) by isolated fetal rat liver parenchymal cells in suspension were studied ultrastructurally and morphometrically. Binding experiments using 125I-labeled LDL were also performed. After a 2-h preincubation in a lipoprotein-free medium and a subsequent 1-h postincubation in the presence of LDL-gold, fetal liver parenchymal cells exhibit a binding of 248 +/- 17 gold conjugates/100 micron plasma membrane and an uptake of 235 +/- 17 gold conjugates/100 micron2 cytoplasm.

Lack of detectable N-nitroso-N-methyl-N-cyclohexylamine in humans after administration of bromhexine.

The possible formation of N-nitroso-N-methyl-N-cyclohexylamine (NMCA) from the drug bromhexine (N-methyl-N-cyclohexyl-(2-amino-3,5-dibromobenzyl)-ammonium hydrochloride) and nitrite was investigated in humans using three different approaches: 1. analysis on metabolites of NMCA in human urine; 2. analysis on NMCA in human gastric juice; 3.

Lack of detectable DNA alkylation for bromhexine in man.

It is known that in vitro incubation of the expectorant drug bromhexine (N-methyl-N-cyclohexyl-(2-amino-3,5-dibromobenzyl)-ammonium hydrochloride) with nitrite yields methylcyclohexyl nitrosamine (NMCA). NMCA is capable of methylating DNA when administered to rats. In vivo tests with bromhexine have also demonstrated that the drug methylates DNA when it is orally administered in the presence of sodium nitrite, presumably due to the intragastric formation of NMCA.

Relation between renal and hepatic excretion of drugs: VII. Hepatic and renal excretion of phenol red in thioacetamide-induced acute and chronic liver damage.

Acute and chronic liver damage was induced in rats by thioacetamide (TAA). Centrilobular liver cell damage associated with an accumulation of lipid droplets was produced by a single high dose (10 mg TAA/100 g b.m.

Rat LDL metabolism in the perinatal period.

In fetal rats at term LDL carries 75% of the total serum cholesterol, whereas in adult ones this value amounts to 20% only. Using a time-dependent two pool model the flux rates for LDL cholesterol can be calculated for the newborn. The data reveal that at birth the LDL cholesterol flux is 15-20 times higher than in the adult.

Short-term effects of carbon tetrachloride on the lipoprotein secretion in isolated rat hepatocytes.

Short-term exposure of isolated rat hepatocytes in suspension to a low dose of CCl4 (20 micrograms/ml) leads within minutes to characteristic structural alterations. The earliest reaction is a disappearance of the microvilli border 5 min after starting the incubation. After 10 min the number of Golgi VLDL is decreased by about 80% and reaches zero after 20 min.

Clinical pharmacology of two specific bradycardiac agents.

The effect of two i.v.-infusion regimens of falipamil on atropine-induced changes of heart rate and the effect of ULFS 49 Cl in 3 different oral doses during a 7-day medication period were studied in volunteers.

In vivo binding and uptake of low-density lipoprotein-gold- and albumin-gold conjugates by parenchymal and sinusoidal cells of the fetal rat liver.

To elucidate the participation of fetal rat liver cells in the receptor-mediated internalization of low-density lipoproteins (LDL), rat fetuses were injected with either LDL-gold or albumin-gold conjugates. The degree of binding and uptake of LDL-gold and albumin-gold by parenchymal and sinusoidal cells of the fetal rat liver differs markedly. Endothelial cells exhibit low LDL-gold uptake.

Pineal region tumours of childhood.

In Germany, the relative frequency of pineal region tumours seems to be much higher than hitherto assumed. At the University Hospital Hamburg, from 1980-1985 17 children with pineal region tumours were encountered amongst 102 children with CNS tumours. Two-cell-type germinoma is the most frequent pineal region tumour.

[Cardiac arrhythmias in active elderly persons--age dependence of heart rate and arrhythmias].

Arrhythmias and heart rate of 82 active elderly persons (mean age 79.5 yrs) were registered by 24-hour electrocardiographic recording and compared with the results of 100 asymptomatic subjects (age 34.8 yrs).

Isolation and characterization of parenchymal cells from normal and cirrhotic rat liver.

A technique is described for isolation of adult rat hepatocytes from micronodular cirrhotic livers based on a collagenase digestion procedure. Hepatocytes from normal livers and those chronically injured by thioacetamide did not differ with respect to the viability measured by the trypan blue exclusion test or to the cellular concentrations of protein and glycogen, but the triglyceride content of cells from cirrhotic livers was significantly reduced. Hepatocytes isolated from cirrhotic livers are ultrastructurally in a good state of preservation but they appear to be poorer than controls in RER membranes, although the well-preserved mitochondria are somewhat richer in cristae.

Binding and internalization of low density lipoproteins in fetal rat liver at term under in vivo and in vitro conditions.

Binding and internalization of rat low density lipoproteins (LDL) by fetal rat liver cells were studied under in vivo and in vitro conditions by ultrastructural and biochemical methods. By using LDL-gold conjugates it could be shown that on day 22 of gestation hepatocytes and Kupffer cells mainly contribute to specific binding and uptake of LDL, but not endothelial cells. Estrogen administration to the pregnant rats stimulated binding and internalization of LDL-gold.