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Biomedical subjects

N Hartmann

Publications and source records attributed to N Hartmann.

At least 19 recordsLinked to original sources
PubMed1992

Pleiotrophin stimulates fibroblasts and endothelial and epithelial cells and is expressed in human cancer.

Previously we reported the purification of the heparin-binding growth factor pleiotrophin (PTN) from supernatants of the human breast cancer cell line MDA-MB-231. To investigate further the biological activities of PTN and its potential role in cancer, we cloned a PTN cDNA and expressed the gene in a human kidney and in a human adrenal carcinoma cell line (SW-13). The supernatants harvested from cells transfected with PTN contained a heparin-binding specific protein of an apparent molecular mass of 18 kDa. These supernatants stimulated the proliferation of endothelial cells as well as the anchorage-independent growth of SW-13 cells and of normal rat kidney fibroblasts. Furthermore, SW-13 cells transfected with PTN acquired autonomous growth in soft agar and were tumorigenic in athymic nude mice. In contrast to these results with PTN from human cells, PTN obtained from insect cells (Sf9) using recombinant baculovirus as a vector was biologically inactive. We detected high levels of PTN mRNA in 16 of 27 primary human breast cancer samples (62%) as well as in 8 of 8 carcinogen-induced rat mammary tumors. Furthermore, 9 of 34 human tumor cell lines of different origin showed detectable PTN mRNA. We conclude that PTN may function as a tumor growth and angiogenesis factor in addition to its role during embryonic development.

Adrenal Gland Neoplasms↗
PubMed1990

Does isoflurane lead to a higher incidence of myocardial infarction and perioperative death than enflurane in coronary artery surgery? A clinical study of 1178 patients.

To examine if the choice of volatile agents influences cardiac outcome in coronary artery surgery, 1178 patients undergoing elective coronary artery bypass grafting without additional operations received enflurane (608) or isoflurane (570) as their primary anesthetics. The inspired concentration of volatile agent (administered with 50% nitrous oxide) was adjusted depending on the level of blood pressure at the discretion of the anesthesiologist. In addition to the volatile agent assigned, each patient received small doses of fentanyl at induction and before sternotomy (total 0.006-0.008 mg/kg). The groups did not differ in preoperative and surgical characteristics except for a more frequent history of renal dysfunction in patients given isoflurane. The rates of postoperative myocardial infarction, administration of positive inotropic agents at the time of weaning from cardiopulmonary bypass, and in-hospital deaths in the enflurane and isoflurane groups were 1.8% and 4.0% (P less than 0.05), 4.9% and 8.1% (P less than 0.05%), and 0.3% and 2.1% (P less than 0.01), respectively. Although the mechanism of the adverse effects of isoflurane could not be clarified in this study, these results demonstrate that the use of isoflurane could be inappropriate in patients undergoing coronary artery bypass grafting.

Aged↗
PubMed1987

[Diplopia, enophthalmos and motility disorders in isolated orbital floor fractures].

In cases of pure blow-out fracture with unequivocal clinical symptoms (limitation of movement of the globe, dislocation and/or enophthalmos) and confirmed X-ray findings, early surgery is the treatment of choice. In cases where the clinical findings are less pronounced, a "wait-and-see" policy, keeping the patient under observation, seems appropriate for the sake of avoiding surgical trauma. Coronal computerized tomography offers advantages in cases where the diagnosis is questionable.

Adult↗
PubMed1980

[The lactate-pyruvate quotient in the framework of modern thyroid diagnosis].

In literature a big number of central and peripheral parameters for the diagnosis and control of therapeutical measures in diseases of human thyroid gland is described. That means, that none of the methods used has a sufficient weight. The enzymatic estimation of pyruvate and lactate reflect the peripheral effect of the hormones of thyroid gland. The pyruvate and lactate levels differ in the several groups of patients with euthyreosis, hypothyreosis, hyperthyreosis and euthyreotic goitre. Between these all groups the lactate/pyruvate ratio showed highly significant differences. The comparison of the lactate/pyruvate ratio and the T3-values showed highly significant correlation between both parameters. This good conformity is underlined by the behaviour of the parameters in courses of therapy, with additional support by farther functional tests--ETR-, T3- and T4-test. Our results confirmed the suggestion, also in agreement with literature, that the lactate/pyruvate ratio represent a possible enrichment in the laboratory programme for diagnosis and control of therapy in patients with thyroid diseases.

Adolescent↗
PubMed1980

[Liver deiodase activity in rats of different body weight and fat contents following high or low fat diet. Comparison of enzymatic deiodination with T4-clearance rate and thyroid activity in animals].

Weanling male wistar rats were fed 4 weeks a standard diet and separated into 2 groups, which received a high fat diet (50% w fat; HFD) or a low fat diet (3% w fat; LFD). These diets were fed 6-8 weeks and the animals then separated into light and heavy animals in each group. T4 deiodination in liver homogenates was investigated in all groups and compared with T4 clearance rate and thyroidal activity of these animals. The HFD-rats showed independently of weight and body fat content significantly higher liver deiodinase activity than LFD-rats. In light and heavy HFD-rats with great differences in body fat content the liver deiodinase activity was equal. T4 deiodination in liver, contrary to the T4 clearance rate, depends on fat content of diet and not of body. The thyroidal radioiodine uptake and PBI-131-values in some weight groups of HFD-rats were significantly higher than in some LFD-weight-groups, but a dependence of the thyroidal activity from fat content of diet or of body was not clearly evident. The results indicate however, that the thyroidal activity is likely not responsible for the increase of liver deiodinase activity after high fat diet. The apparent discrepancy between the results of higher liver T4 deiodination and equal or lower T4 clearance rate or equal T3 serum concentrations is discussed.

Animals↗
PubMed1979

[Effect of diet and L-thyroxine on deiodination of L-thyroxine in rat liver].

Male Wistar rats on 3 or 50% fat diet for 14 weeks were treated during 6 weeks with L-thyroxine (5 or 25 or 50 microgram 100 g body weight/2 times weekly, sc.) and the activity of L-thyroxine-deiodinase was determined in supernatans of liver homogenates. With increasing thyroxine lading the deiodinating activity increases statistically significantly within each diet group. The liver of animals on 50% fat diet deiodinates increasing thyroxine doses to a lesser extent than livers of animals on 3% fat diet. It is discussed that high fat diet influences thyroid function and that thyroxine shares effectiveness and undergoes deiodination also in other tissues, probably in fat tissue, to a higher extent.

Animals↗
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↗
PubMed1978

[Heart trauma caused by central venous catheter (author's transl)].

Four cases of extensive traumatic lesions of the right atrium induced by central venous catheter, are reported. In one case there was beginning in the other complete perforation of the right atrium. Such lesions can be caused by horizontal fixation of the intracardiac portion of a catheter due to wall-adherent thrombi; catheters held near the coronary sinus by a so-called Chiari net; or by coiling of the catheter within the atrium. Central venous catheters often cause endothelial lesions and thrombotic changes in the veins near the heart. Possible trauma to the right atrium, which could provoke fatal complications (e. g. haemopericardium or arrhythmias) must, therefore, be given special attention.

Adult↗
PubMed1978

[Properties of adipocytes (diameter, volume, triglyceride content, cell number) of certain types of fatty tissue as a function of age in male Wistar rats].

The diameter, volume, triglyceride content and number of adipocytes were determined in male Wistar rats at the age of 6 weeks and 2, 3, 12 and 18 months, respectively. A standard diet and water were given ad libitum. The adipocytes were isolated by means of the method of RODBELL. The weight and fat content of the fatty tissues were determined gravimetrically. Age exerts no effect on the adipocyte parameter, nor on the weight and the fat content of the fatty tissue. In contrast to this, there are relationships between adipocyte diameter and the increases in body weight. In all age groups, the increase in size and number of the adipocytes was significantly greater in heavy animals than in light ones. Genetic, hormonal and dietarily-induced factors are discussed as a possible cause. The authors observed no difference in adipocyte size between epididymal and perirenal fatty tissues. As compared to this, the mesenteric adipocytes were smaller.

Adipose Tissue↗
PubMed1978

[Effect of a high fat diet on the behavior of the diameter, volume, triglyceride content and number of the adipocytes in different types of fatty tissues in male Wistar rats].

The effect of a high-fat diet on the diameter, volume, triglyceride content and number of the adipocytes was studied in male Wistar rats at the age of 9 weeks and 6 months, respectively. The adipocytes were isolated by means of the method of RODBELL. The adipocyte diameters were measured using the microscopic method. The weight and the fat content of the fatty tissue were determined gravimetrically. A diet containing 50% fat increases the diameter, volume and triglyceride content of the adipocytes and also the weight and the fat content of the different types of fatty tissue. The fat content of the diet and the duration of feeding are of importance. The high-fat diet exerts no effect on the adipocyte number. However, in both age groups, the adipocyte numbers were sometimes greater in heavy animals than in light ones fed the same diet. Genetic, hormonal, and dietarily-induced factors are considered as a possible cause.

Adipose Tissue↗