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T Zimmermann

Publications and source records attributed to T Zimmermann.

At least 181 records · Page 10Linked to original sources
PubMed1987

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. No differences were detected between the cell preparations in rates of gluconeogenesis and total de novo fatty acid synthesis, but the secretion of newly synthesized fatty acids was significantly reduced in cells from cirrhotic livers. Thus adult rat hepatocytes can be isolated from thioacetamide-induced micronodular cirrhotic livers with high yield and morphological integrity. Differentiated functions are maintained in suspension for at least 4 h.

Animals↗
PubMed1987

Experimental liver cirrhosis does not influence reproductive performance of female rats and development of hepatic biotransformation in their offspring.

Experimental hepatic cirrhosis was produced in virgin female Wistar rats by thioacetamide (TAA) administration with the drinking water from the 4th up to the 6th month of life. Mating occurred 31 +/- 3 d after cessation of TAA treatment. At the time the body mass of cirrhotic rats was not different from that of untreated controls. Body mass gain during pregnancy, length of gestation, litter size and body mass of the newborns were not influenced by experimental cirrhosis. Lactation seems to be slightly decreased in TAA-dams in the first 5 postnatal days, reflected by lower growth rates of TAA- and control-pups nursed by TAA- in comparison to control-dams. Somatic development (body mass) and hepatic biotransformation (ethylmorphine N-demethylation and ethoxycoumarin O-deethylation) were not different in the TAA- and control-offspring up to adulthood. Liver mass was enhanced in TAA-offspring at birth, but not any longer in 10-d-old and older rats.

Animals↗
PubMed1987

Improved in vitro diagnosis of allergy to Alternaria tenius and Cladosporium herbarum.

To improve the in vitro diagnosis of mould allergy 22 children suffering from allergic asthma caused by Alternaria tenius and/or Cladosporium herbarum as proven by bronchial provocation test were investigated. Partially purified, standardized mould preparations were used in radioallergosorbent test (RAST) with conventional and new update mould discs, mould-induced histamine release and immunoblotting. Updated RAST discs were found to be superior to the old-type discs for the detection of Alternaria but not Cladosporium sensitivity. In all patients except one, specific IgE-antibodies to the respective mould were demonstrated by immunoblotting. Mould-induced histamine release failed to prove sensitization in only two patients. No differences were found comparing histamine release from whole blood with release from isolated cells. The results demonstrate a high sensitivity of in vitro tests when purified and standardized extracts are used.

Allergens↗
PubMed1986

Studies on lipid and lipoprotein metabolism in rat liver cirrhosis induced by different regimens of thioacetamide administration.

In female Wistar rats the animal model of TAA-induced liver cirrhosis has been tested for reliability and usefulness for studies on lipid and lipoprotein metabolism in cirrhosis. From our results we draw the following conclusions: Application of 300 mg TAA/l drinking water from the 4th to the 6th month of life leads in all treated rats to liver cirrhosis which is rather uniformly of micronodular surface morphology. Under this treatment the survival rate is about 90 percent. Increasing the administered dose (450 and 600 mg/l) and/or extension of TAA administration time (4 or more months) leads to decreasing survival rates, and to a shift from micronodular towards macronodular cirrhosis. To produce macronodular cirrhosis it is suggested to extent the application time rather than to increase the dose since in the latter case the survival rate is very low. The alterations of lipid and lipoprotein metabolism observed in this animal model, i.e. decrease of pre-beta-lipoproteins, increase of beta-lipoproteins, decrease of serum triglyceride concentration and decrease of hepatic VLDL-TG output into the serum are in good agreement with those observed in human cirrhosis. Thus, the TAA-induced chronic liver injury proved to be a reliable and useful model for studies on lipid and lipoprotein metabolism in liver cirrhosis.

Acetamides↗
PubMed1986

Quantitative studies on the fetal lipid metabolism in rats: liver fatty acid esterification and conversion into carbon dioxide, and hepatic output of triglycerides and phospholipids into serum.

Fetal lipid metabolism was studied quantitatively using the 14C-1-palmitate in vivo tracer technique and compartment analysis, and in vitro incorporation experiments. The following conclusions can be drawn from our experiments. Fetal serum free fatty acids (FFA) exchange so rapidly with the FFA of another compartment that the FFA of both compartments can be considered as one homogeneous FFA compartment. The turnover time of this compartment was calculated to be 0.76 mumol FFA/min/l through this compartment. The incorporation of fetal serum FFAs into fetal liver triglyceride fatty acids (TG-FA) and phospholipid fatty acids (PL-FA) was calculated to be 0.05 and 0.14 mumol FFA/min/l, respectively. Thus, only 16% of the fetal serum FFA is incorporated into fetal liver lipids. The fetal serum TG-FA most likely originate in the fetal liver. The fetal liver puts out 0.025 mumol TG-FA/min/l and 0.10 mumol PL-FA/min/l into the fetal serum. The turnover times of fetal serum TG-FA and PL-FA are 100 and 39 min, respectively. The fetal liver conversion rate of fatty acids (FA) into CO2 determined in vitro (0.06 mumol FA/min/l) amounts to about 25% of the rate seen in the whole rat fetus.

Animals↗
PubMed1986

[Intralobar lung sequestration. Diagnosis using the duplex-scan technic].

A 3 7/12 year old boy, suffered from a intralobar sequestration of the lung and recurrent pneumonia. In the area of the right lower lobe, a plain film showed a limited density. The ultrasonographic evaluation demonstrated a homogenous tumor above the diaphragm. We found pulsatile flow patterns by pulsed doppler sonography within the arteries feeding the sequestration. Aortography finally clearly showed the anomalous arteries leading from the descending aorta to the sequestrum. Bronchoscopy and bronchography demonstrated, that the sequestered area of the lung had no open connexion to the rest of the bronchial tree. Surgical treatment is the only possible method to remove the cause of the recurrent infections.

Aortography↗
PubMed1985

Changes in intra- and extrahepatic VLDL in the rat following acute injury by thioacetamide. A morphometric and biochemical study.

The effect of a single dose of TAA (100 mg/kg body weight) on intra- and extrahepatic lipoproteins of the very low density (VLDL) type was studied in rats by morphometric and biochemical methods. For a better quantification of VLDL in the periportal (zone 1) and centrilobular (zone 3) hepatocytes of control and TAA-intoxicated livers, colchicine was used as an inhibitor of hepatic lipoprotein secretion. Generally, there exists a great functional heterogeneity between the hepatocytes of zone 1 and 3 in the colchicine-treated controls manifested in a significantly different accumulation rate of VLDL particles. The mean number of VLDL particles per vesicle, the mean secretory vesicle size and the volume density of the electron-lucent secretory vesicles are two times larger in hepatocytes of zone 1 than zone 3. The volume of the VLDL particles amounts to 7.3 X 10(-5) microns3 and 22 X 10(-5) microns3 in the peri- and centrilobular regions. On the other hand, there is no significant lobular-zonal difference in the number of light and dark secretory vesicles. Within 48 h TAA treatment causes a reduction in the number of VLDL particles/100 microns 2 in zone 1 and 3 by 66% and 61%, whereas the number of light secretory vesicles is decreased by 31% and 58%, respectively. The volume density of the latter is significantly diminished only in zone 1. Moreover, the VLDL particle volume is reduced to nearly 50% in each lobular zone examined. The data obtained after TAA treatment from the electron-dense secretory vesicles do not differ significantly from those of the colchicine-treated controls. Acute TAA intoxication lowers the hepatic VLDL-TG output by about 50% in comparison with controls. The steady state of the serum TG concentration after TAA application implies that the clearance of TG from the serum must be diminished to the same extent as the hepatic TG output is found to decrease due to acute liver injury. The results presented here support our view that acute TAA intoxication lowers the hepatic VLDL output by inhibiting the intracellular formation of VLDL. The intrahepatic degradation of the newly synthesized VLDL seems to be unaffected. Despite the fact that the substructure of the hepatocytes in zone 3 is much more changed than in zone 1 after TAA treatment the quantitative data on the VLDL secretory products provide evidence that the process of lipoprotein formation is disturbed to nearly the same extent by TAA both in zone 1 and 3.

Acetamides↗
PubMed1985

Biochemical and substructural studies on hepatic and serum lipoprotein metabolism after acute liver injury induced by thioacetamide in rats.

The effect of an acute liver injury induced by thioacetamide (TAA) on hepatic and serum lipoprotein metabolism in rats was studied using biochemical and ultrastructural methods. A single dose of 100 mg TAA/kg body weight caused within 48 h a decrease of hepatic triglyceride (TG) output into the serum by about 50% in comparison to the controls. The steady state of serum TG concentration from 24 to 96 h after TAA treatment implies that the clearance of TG from serum must be diminished to the same extent as the hepatic TG output was found to decrease. Moreover, the TAA treatment caused changes in the electrophoretic mobility as well as in the concentration and composition of circulating serum-lipoproteins. The electrophoresis revealed a decrease in the alpha-band, which can be explained by the decrease in the high density lipoproteins (HDL) total lipid concentration. The pre-beta-migrating band disappeared, whereas a broad beta-mobility band appeared, which most likely consists of a mixture of very low density lipoproteins (VLDL) and low density lipoproteins (LDL) as can be concluded from the changes in concentration and composition of lipids in both fractions. For a better visualization of the VLDL-forming capability in perilobular and centrolobular liver parenchymal cells of the TAA-treated animals the VLDL secretion blocking agent colchicine was used. It was shown that in comparison with colchicine-treated controls the VLDL secretory products are accumulated at a considerably lower rate manifested in a diminution of VLDL clusters, secretory vesicle size and the number of intravesicular VLDL particles.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetamides↗
PubMed1985

[Frequency of sensitization to D. pteronyssinus or D. farinae in children with perennial bronchial asthma].

Bronchial sensitization against house dust mites (dermatophagoides farinae, dermatophagoides pteronyssinus) was investigated in 48 children. The therapeutic effect of hyposensitization and removal of house dust mite allergen was evaluated. The diagnosis was established by skin-prick-test, RAST and bronchial provocation. The bronchial provocation test was carried out by a whole body plethysmograph with breath by breath registration of the airway resistance. We found a bronchial reaction against both mites in 70% of the children; 18% showed bronchial reaction only against d. farinae, 10% only against d. pteronyssinus. There was a better correlation between RAST and bronchial provocation (69,5%) than between skin-prick-test and bronchial provocation (65%). The correlation concerning the skin-brick-test and RAST was 55% with d. farinae and 59% with d. pteronyssinus. There was no correlation between PRIST and RAST, RAST and eosinophiles, therapeutic effects of hyposensitization and positive allergen tests. After one year of therapy, the conditions of 87,5% (only mite sensitization) respectively 92% (mixed sensitization) of patients improved. Another group of sensitized children was only treated by removal of house dust mite allergen and anti-allergic and bronchodilating drugs. 43% (mixed allergy) respectively 54% (only mite sensitization) had less asthma problems. After the hyposensitization the children showed a significant improvement. There was no difference in the therapeutic effect after hyposensitization against d. farinae or d. pteronyssinus.

Adolescent↗
PubMed1984

Comparison of two bacterial azoreductases acquired during adaptation to growth on azo dyes.

Selection for utilization of carboxy-Orange I [1-(4'-carboxyphenylazo)-4-naphthol] in the chemostat yielded Pseudomonas strain K24 which was unable to grow on carboxy-Orange II [1-(4'-carboxyphenylazo)-2-naphthol] while selection for growth on carboxy-Orange II had previously led to strain KF46 which did not utilize carboxy-Orange I. Orange I azoreductase of strain K24, the key enzyme of dye degradation, was purified 80-fold with 17% yield to electrophoretic homogeneity and compared to the previously purified Orange II azoreductase of strain KF46. Common properties of the two enzymes were their monomeric structure, their specificity for NADPH and NADH as cosubstrates, the range of their Km values for substrates and cosubstrates as well as their reactivity towards a series of substrate analogs. They differed from each other with respect to molecular weight (21,000 and 30,000) and in the absolute requirement of Orange I azoreductase for a hydroxy group in the 4'position of the naphthol ring of the substrate molecule as compared to the requirement for substrates with a 2-naphthol moiety by Orange II azoreductase. The pure enzymes did not exhibit immunological cross-reaction with each other. Crude extracts of strains K24 and KF46 and of azoreductase-negative strains isolated at different stages of the adaptation experiments, however, contained material which cross-reacted (CRM) with both anti Orange I azoreductase serum and anti Orange II azoreductase serum. The CRM may represent a common precursor protein of the azoreductases in strains K24 and KF46.

Adaptation, Physiological↗
PubMed1984

Studies on the fatty acid synthesis of the perfused cirrhotic liver.

The fatty acid synthesis rate (using 3H2O incorporation experiments) and bile composition were studied in thioacetamide induced cirrhotic rat livers. The results show that the fatty acid synthesis rate of cirrhotic livers expressed as mumoles newly synthesized fatty acids per g liver is smaller than that of controls. Transient changes were observed in the incorporation pattern of newly synthesized fatty acids into individual lipid classes between cirrhotic and control livers. The output of bile acids is significantly decreased in cirrhotic livers.

Animals↗
PubMed1984

[Bronchial asthma in childhood. Therapy with fenoterol and ipratropium bromide powder].

In a double blind randomized study during a period of 2 weeks we compared the therapeutic effectiveness and side effects of IK-6-Inhaletten (0.1 mg Fenoterol + 0.04 mg Ipratropiumbromide) and SCH 1000-Inhaletten (0.2 mg Ipratropiumbromide) in 39 children (4-14 years) suffering from mild, moderate or severe asthma bronchiale. All measurements were performed with a whole body plethysmograph. In contrast to SCH 1000-inhalation after inhalation of IK-6-Inhaletten, we found a good improvement of the total airway resistance Rtot, the specific airway resistance SRaw and the forced exspiratory volume FEV1. Especially SRaw was significantly diminished compared to the less effective SCH 1000-inhalation. IK-6-inhalation allowed to decrease the amount of bronchospasmolytic therapy in our group of patients. We did not observe any severe side effects after inhalation of IK-6 or SCH 1000. In summary, we recommend the application of the IK-6-Inhaletten in children suffering from mild and moderate asthma bronchiale.

Adolescent↗