Search PubMed⌕ Search

Biomedical subjects

K Hartmann

Publications and source records attributed to K Hartmann.

At least 181 records · Page 10Linked to original sources
PubMed1979

[T4 metabolism in age matched heavy and light rats with good and bad feed efficiency following high- or low-in-fat diet].

Rats, fed two diets (high or low in fat content), were at the and of the feeding-period separated in light and in heavy animal groups. The leaner rats from the diet group high in fat content show opposite to the heavier animals of this diet group significantly increased T4 distribution spaces, significantly shortened T4 half life time and lower feed efficiency. T4 serum values, absolute T4 degradation per day and body mass and free thyroxine index in these leaner rats also increased significantly. However comparing heavy rats feed a diet low and light rats fed a diet high in rat content the latter show also a decreased feed efficiency, but no differences in T4 serum concentration or T3 binding capacity of serum proteins, free thyroxine index and T4 degradation. The results in T4 metabolism are discussed in relation to feed efficiency of the investigated animal groups.

Animals↗
PubMed1979

[Iodoamino acid distribution and weight of the thyroid gland, T4 serum level and T4 metabolism in relation to diet, body fat content and age of rats].

Rats were rendered obese by feeding them a fatty diet (HFD, fat: 50% of weight). At the end of the experimental period the animals were divided, also the control rats, which were fed a low-fat diet (LFD, fat: 3% of weight), in light and heavy weight groups. The heavy and obese HFD groups showed, unlike the light LFD-animals, equal absolute but significantly lower relative thyroidal weights. The absolute thyroidal weights of light and heavy animal groups, which received in each case the same diet, were identical, the relative thyroidal weights of the heavy rats on the other hand decreased significantly. The iodoamino acid distribution in the thyroid of rats showed no variation in animals fed various diets and differed in body mass and fat content. The T4 serum levels of the HFD-, in comparison to the LFD-animals increased significantly. Between light and heavy animals in equal diet groups no differences were obtained for the T4 serum values. The serum T3 levels of LFD- and HFD-rats were also equal. The heavy HFD- showed in comparison to the light LFD-animals a significantly lower T4 clearance and in the higher age groups a significantly extended T4 half-life time. The HFD- and LFD-rats with approximately equal body mass and body fat content showed no differences in T4 half-life time and T4 clearance rate depending on diet. A relation between higher body fat content and increased serum T4 levels as a possible adaption to obesity in heavy HFD-rats is discussed. By the comparison of younger and older rats in the most investigated diet and weight groups the older animals showed a decreasing tendency for K and TD/100 g KM and a significant decrease in the clearance rate and in the TD for T4, related to body mass. An influence of diet, body mass or fat content on the decrease of the T4 metabolism of rats with increased age is not evident. The T4 serum levels were not different in dependence on age, but the free T4 serum level was significantly lower in the older rats.

Adipose Tissue↗
PubMed1979

[Methodical optimization of redioiodine uptake experiments in living rats].

The paper deals with the estimation of thyroidal uptake of 131I in living rats. The animals are fixed in a specially marked glass tube. This tube is discontinuously moved over a scintillation counter within a lead collimator. Counts of 131I are estimated segmentically. The highest counts ratio with the geometrical factor of the appropriate segment is used to calculate the thyroidal radioiodine uptake. Similar results, obtained with an 131I-source placed in various segments of the top side of glass tube, indicate that the uptake values obtained in this manner exact. Thyroidal uptake values, which were received on living rats with this method (in vivo) and compared with values obtained with the prepared and plated thyroid of the same rats (in vitro) show a very high correlation (r = 0,99; p greater than 0,001). In repeated estimations of the thyroidal 131I-uptake on one animal a variation coefficient of 1.5% (n = 13) was obtained. The advantage of this in vivo method is the possibility to determine the thyroidal activity at various times after 131I-application (2 phase test) and by repeated 131I-applications under different conditions (diet, age, for instance).

Animals↗
PubMed1978

[Postnatal development of the epithelium of the small intestine of guinea-pigs (author's transl)].

This investigation deals with the histochemical, biochemical and electron microscopical development of the postnatal epithelium in the small intestine of guinea-pigs. Immediately after birth the enterocytes of the whole small intestine are rich in glycogen. Within 48 hours the glycogen in broken down by intralysosomal digestion and glycogenolysis or disappears from the villus epithelium by extrusion of the absorptive cells. The first loss of glycogen occurs in the jejunum; at the latest it leaves the lining epithelium of the ileum so that a proxoim-distal gradient exists. Afterwards for maximal 14 days fat ist taken up from the mother's milk only by the enterocytes of the jejunum without any signs of endocytosis; the bigger part of the fat leaves the cells by exocytosis and enters the intercellular space. Most of the lipid reaches the lymphatics or is absorbed by marcophages; only small amounts are found in the blood capillaries. The number of the enterocytes engaged in the absorption and passage of fat depends on its quantity in the lumen of the small intestine. During the first days of life everywhere in the small intestine the ultrastructure of the enterocytes is characterized by 2 types of mitochondria (large and small ones with different internal structure). Furthermore in the ileum the absorptive cells contain more lysosomes and a more extensive inframicrovillous membrane system than in jejunum. The membrane system consists of aggregated tubules, vacuoles and vesicles; they are situated below the microvilli and sometimes communicate with the lumen of the gut. The big mitochondria are broken down in the lysosomes or appear in the lumen of the small bowel following extrusion of the enterocytes. The lysosomes are involved in autophagic (digestion of glycogen and cell organelles) as well as in autophagic processes (hydrolysis of molecules from the mother's milk and foreign food). These substances are probably incorporated by means of the inframicrovillous membrane system. With respect to the microvillous hydrolases (lactase, alpha-D-glucosidases, peptidases, alkaline phosphatase) histochemical and biochemical assays were carried out with the same artificial substrate. The results depend on the method employed and the enzyme investigated. Using histochemical techniques and indolyl, naphthly, naphthol AS or naphthylamine derivatives as substrates the activity of peptidases and alkaline phosphatase correspond to that in adult guinea-pigs already at the time of birth; alpha-D-glucosidases (glucoamylase, saccharaseisomaltase) become mature at the end of the first, and the development of lactase is finished after the second week of life. For the biochemical investigations (fluorometric measurements of naphthol and naphthylamine) of microvillous enzymes with naphthyl and naphthylamine substrates a new technique of homogenisation using freeze-dried cryostate sections is successfully employed...

Animals↗
PubMed1978

[Surgical treatment of entropium senile (author's transl)].

The authors report on a modification of the entropion surgery of Celsus-Hotz which was successfully carried out in 87 patients with entropion senile from 1969 to 1976. After excision of an about 5 mm wide crescentshaped dermal tissue of the lower eyelid about 3 mm down the margin the muscle fibres of the M. orbicularis near the margin are resected. Before suturing the skin 3-6 stitches of Hotz are done to reduce the tarsus. The advantages of this technique are the safe therapeutical effect, the cosmetical effect and the easy correction of this operation in case of a failure.

Aged↗
PubMed1978

[Glucose-6-phosphate dehydrogenase activity in the liver of rats with experimental hyperthyroxinemia and hypothyroidism].

The activity of glucose-6-phosphate dehydrogenase was investigated in liver of hyperthyroxinemic or hypothyreotic rats. The enzyme activity level in hyperthyroxic rats. The enzyme activity level in hyperthyroxinemic animals was significantly elevated in contrast to the hypothyreotic rats, who showed significantly reduced enzyme activity. The protein concentration in liver extracts of hyperthyroxinemic animals was slightly elevated, while hypothyreotic animals showed significantly reduced protein content of the extract.

Animals↗
PubMed1978

[The place of ultrasonic tomography in irradiation planning (author's transl)].

Therapy-planning frequently requires cross-section sketches of the body in correct scale. The use of anatomic-topographic standard cross sections can lead to considerable errors in the estimation of the actual position of the organs and yields no information on the extension of the pathological process. The kidney, the bladder and the prostate were used as examples to demonstrate the capacity of ultrasonic tomography to supply all information, including body contour, relevant to therapy planning, as long as no limits are set to the procedure, as in the thorax area. Ultrasonic tomography can supplement but not replace the radiological procedure in therapy-planning.

Humans↗
PubMed1978

[Effect of diet and thyroxine on body composition in rats].

In young male Wistar rats the influence of different fat content of the diet (7 or 25 or 50 weight percent of fat) and of thyroxine (5 or 50 microgram/100 g body mass, 2 times/week, sc.) on body composition was investigated by carcass analysis. After high doses of thyroxine the percentage body fat decreases and protein and water content increases within the same diet group (7 or 25 or 50% fat diet). Smaller doses of thyroxine have only the same effect as high thyroxine doses in the 7% fat diet group; the body composition is unchanged in the 25% fat diet group, and in rats after 50% fat diet thyroxine even brings about an increase in body fat. It is concluded that the fat content of the diet makes thyroxine partly ineffective. A comparison of the different diet groups, also with or without thyroxine treatment, brings the result of significantly increased percentage body fat after 25 and 50% fat diet; body protein and body water decreases respectively. It appears from the present study that controversial results in literature concerning body composition after thyroxine treatment, may be caused by different diets, especially the fat content of the diets.

Animals↗
PubMed1978

[Uptake of utilizable food energy by light-weight and heavy-weight rats fed a low-fat or high-fat diet].

The uptake of utilizable dietary energy (DE) as affected by diet (containing 3 or 50% (w/w)fat), body mass (BM) and age was investigated in male Wistar rats. In comparing heavy-weight animals fed the high-fat diet (HFD) with light-weight animals fed the low-fat diet (LFD) (differences in BM up to 60%), it was found that the uptakes of DE calculated on animal were significantly higher (up to 55%) in the HFD animals than in the LFD animals; but there were no significant differences when the uptakes of DE were calculated on 100 g BM. Thus, the LFD rats (the diet of which contained a high proportion of protein (70% (w/w)) exhibited no reduced uptakes of utilizable DE as compared to HFD rats. Of the heavy-weight LFD animals and the light-weight HFD animals which showed virtually no differences in BM, the HFD animals take up more utilizable DE (per animal or per 100 g BM) than the LFD animals. This difference, which amounts to 60%, is statistically significant. The comparison of the uptakes of DE/animal/100 g BM by light-weight rats with those by heavy-weight rats fed the same diet showed that the uptakes by the heavy-weight animals were in most cases significantly greater. Consequently, the greater BM of the heavy-weight animals of the respective diet groups must be attributed to more efficient utilization of feed. This is also indicated by the fact that the light-weight HFD animals excret more fat in the faeces than the heavy-weight animals. The amount of fat excreted by the HFD animals is some 10-fold greater than that excreted by the LFD animals. However, when the amount of excreted fat is expressed in % of ingested dietary fat, the fat excretion is of the same order of magnitude on both diets.

Aging↗
PubMed1978

[Changed body composition by increased total body fat content in experimentally hypothyroid rats].

Total body fat content was determined in growing normal male Wistar rats and hypothyroidized animals 7 weeks after feeding with Methimazol (group MMI-HT), Methyl-thiouracil (group MTU-HT), and performance of radiothyroidectomy by 131-iodine (group R-HT), respectively. At the end of experiments there was an extreme hypothyroid state in all treated groups, verified by external signs, growth kinetics, serum cholesterol estimation and evaluation of the iodothyrosine pattern of the thyroid glands. Changed body composition resulted in all HT-groups from significant increase of total body fat content. The relation of constituents fat : protein : water of 1 : 2 : 6 in the KT-group was changed into 1 : 1 : 3 in the HT-groups. No differences were found between the different HT-groups. Our findings are in good agreement with altered metabolism of plasma lipids described by other authors showing the existence of a highly disturbed lipid metabolism in thyroid hormone deficiency.

Animals↗
PubMed1977

[Effects of two special diets on the body weight of rats].

The authors studied the effects of 2 special diets on the weight behaviour of male Wistar rats (aged 4--5 weeks) from Schönerlinde near Berlin up to the age of 35 weeks. The weight behaviour of rats fed a standard diet (commercially available pellets) lies between those of the experimental rats and near that of the rats on low-fat (3%) diet. The one special diet that contains 3% of fat is low-fat (8.4% of the gross energy of the feed) and high-protein (69.3% of the gross energy); the other diet that contains 50% of fat is high-fat (76% of the gross energy). The two diets (containing 331 and 612 kcal/100 g, respectively) are not isocaloric but the animals on the low-fat diet ate twice as much as the animals on the high-fat diet. The rats on the high-protein low-fat diet were prone to copious sweating. It was generally noticed that the animals on the high-fat diet became to a greater extent hypokinetic with increasing age. The weight difference between the two dietary groups increased with increasing age, reaching its maximum value (77%) at the age of 24 weeks and then decreasing to 60% (at the age of 35 weeks). Up to the age of 12 weeks, the rats are in the more "dynamic" phase of weight increase; and from the 16th week, in the more "static" phase of weight increase.

Aging↗
PubMed1977

[Effect of protein content and thyroid hormone on body composition in growing rats].

The effects of an isocaloric control diet of high-protein and low-protein diets (in which protein amounted to 16, 62 and 2% of total calorie content, respectively) with and without simultaneous administration of Thyreotom or methylthiouracil on total body composition have been studied in growing male Wistar rats. In spite of higher average Kcal intake (per day and 100 g of body weight), the rats on the high-protein diet were weighing less than the control animals at the end of the experiment. As compared to the control animals, the rats on the high-protein diet as well as those on the low-protein diet showed a greater relative weight of the thyroid gland. The protein percentage of the body was not significantly increased by an increase in protein supply; likewise, it was not significantly reduced by a decrease in protein supply. The body fat content was by 2/3 lower in the rats on the lowprotein diet than in the control animals. This difference was statistically significant. Thyroid hormones (1 mug liothyronine + 4 mug levothyroxine/100 g body weight, administered orally for 3 weeks) produced a slight increase of body protein in the rats on the high-protein diet; they increased it significantly in the rats on the low-protein diet. Body fat was correspondingly reduced. Methylthiouracil reduces the body fat content in the control animals and in the rats on the high-protein diet; it increased the body fat content in the rats on the low-protein diet. Our results confirm the partial findings of human pathology and demonstrate clearly that nutritional diseases, especially protein deficiency, worsen considerably in case of concomitant disorders of thyroid hormone metabolism.

Animals↗
PubMed1977

[Total body analysis of rats with special regard to fat determination. Possibility of determining fat and proteins by calculation].

The authors present a method for the whole body analysis of rats which combines the animal body preparation according to Mickelsen with the lipid analysis according to Folch; the liquid analysis has been somewhat modified. In this way and by the non-gutting of the animals, the determination of the body fat becomes less laborious. The body fat content can also be calculated from the water content. The body water content was determined gravimetrically. The body protein content was determined according to Kjeldahl; the protein content may also be calculated from the fat and water contents if an error range of +1% is acceptable.

Animals↗