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Biomedical subjects

I Hagemann

Publications and source records attributed to I Hagemann.

At least 19 recordsLinked to original sources
PubMed1999

Intermittent feeding and fasting reduces diabetes incidence in BB rats.

Food intake may be one of several factors which influence the risk of development of insulin dependent diabetes mellitus, but the influence of the pattern of food supply has not been studied previously. The aim of the present study was to investigate the effect of intermittent feeding and fasting upon diabetes in BB rats. This study included three groups. Group 1 served as control and included 77 animals, 79% became diabetic. In groups 2 and 3, after weaning, food but not water was withdrawn from the animals: 24 h twice a week in group 2; 24 h every second day in group 3. Group 2 included 40 BB rats, 50% (p < 0.004) became diabetic. Group 3 included 44 BB rats, 52% (p < 0.01) became diabetic. No differences were seen between sexes. Degree of insulitis was not influenced by changed food supply. Regarding blood glucose, no influence was seen among diabetic animals, among non-diabetic animals changed food supply reduced blood glucose values obtained at the end of the study. Intermittent feeding and fasting tended to reduce mean age at the time of diagnosis of diabetes, significance was reached only in female animals from group 3 compared to group 1. Body weight was obtained weekly. Intermittent feeding and fasting caused a reduced weight gain in group 2 as well as in group 3 compared to control animals; however, most pronounced in group 3 and also more pronounced among males compared to females. For pre-diabetic and non-diabetic animals comparable influence on body weight was seen. The main conclusion in the study is that intermittent feeding and fasting reduced diabetes incidence in BB rats.

Age Factors↗
PubMed1997

Influence of high-dose ketamine on the vascular reactivity of human and porcine isolated coronary artery segments.

The influence of ketamine on the vasomotor effect of histamine and serotonin was studied in isolated human and porcine coronary artery rings. Ketamine (10(-3) mol L-1) attenuated the contractile response to both mediators significantly (P < 0.05 for histamine concentrations of 3 x 10(-5) mol L-1 and above as well as for serotonin concentrations of 3 x 10(-8) mol L-1 and above). This effect of ketamine was observed in intact and endothelial denuded porcine rings (difference n.s.) as well as in coronary arteries from explanted human hearts of patients undergoing heart transplantation. It is concluded that this reduction of the contractile response to histamine and serotonin caused by ketamine is not dependent on the endothelial function (e.g. endothelium-derived relaxing factor).

Anesthetics, Dissociative↗
PubMed1996

Topical treatment by urea reduces epidermal hyperproliferation and induces differentiation in psoriasis.

The mechanisms of action of urea-containing ointments in the treatment of eczema, ichthyosis and psoriasis are only partly known and related to proteolysis and keratinolysis. In this study, we have examined the effects of topical urea on epidermal proliferation and differentiation in 10 patients with psoriasis. Plaque type lesions were treated for 2 weeks with an ointment containing 10% urea, with the vehicle alone, or left untreated. Clinical score, hydration of the stratum corneum, transepidermal water loss (TEWL), and immunohistochemical studies were performed. Epidermal proliferation was assessed using the Ki-S3 proliferation-associated nuclear antigen. For epidermal differentiation antibodies against involucrin and against keratins CK 5, 6, 17 and CK 1, 5, 10, 14 were used. The patients showed a reduction of the clinical score (> 50%), a 2-fold increase in stratum corneum hydration (p < 0.01), and a small decrease in TEWL (N.S.) on the urea- treated compared to the untreated site. Light microscopy studies revealed a 29% reduction in epidermal thickness (p < 0.01); epidermal proliferation was decreased by 51% (p < 0.005). The altered expression of involucrin and of cytokeratins (reduction of CK 5, 1 and 10 and induction of CK 6 and 17) was partially reversed. The ointment base also improved psoriasis, but urea was significantly better than the vehicle (urea: 40% reduction in epidermal proliferation vs. vehicle). In summary, these studies show that urea influences epidermal proliferation and differentiation in psoriasis.

Administration, Topical↗
PubMed1987

[Methods for determining the glomerular filtration rate in experiments with small animals: position report of the Animal Experiment Diagnosis of Kidney Function Study Group of the Society of Nephrology of East Germany].

The methods of the investigation of the glomerular filtration rate (GFR) in the animal experiment on cats and rats used at present are demonstrated as survey and the results of the basic investigations are compared. The values in cats lie between 20 and 30 ml/min/100 g kidney, in rats GFR values are between 0.6 and 1.0 ml/min/100 g body mass and 0.6-0.3 ml/min/1 g kidney. The basic values are essentially influenced by the experimental conditions and determination methods so that only clearance values within the working team concerned are comparable.

Animals↗
PubMed1987

[Kidney function in spontaneously hypertensive rats under minoxidil treatment].

In 25 spontaneously hypertensive rats the blood pressure was lowered from 192 +/- 11.6 to 130 +/- 11.7 mm Hg and in 26 normotensive Wistar rats from 129 +/- 9.1 to 107 +/- 6.7 mm Hg by applying 1 mg/kg body weight minoxidil twice a day orally. 19 spontaneously hypertensive and 21 normotensive rats served as untreated control groups. During the treatment the glomerular filtration rate, determined by the slope clearance of Tc-99m-DTPA, remained unchanged. Under maximal water diuresis the excretion fraction of sodium was diminished compared with the control data. The Na+ and water reabsorption was increased in the proximal tubules (not an aldosterone effect) only in the treated spontaneously hypertensive rats. The potassium clearance was increased in this group, but decreased in the treated normotensive group. The different reactions of the renal tubular function to the treatment with minoxidil in spontaneously hypertensive compared with normotensive rats were discussed in connection with changes of membrane transport in essential hypertension.

Animals↗
PubMed1986

[Modern study methods in experimental nephrology].

The investigation technique of the experimental nephrology comprise in-vivo and in-vitro methods. This order results from the increasing reduction of the size of the investigation object, beginning with the kidneys in the intact organism up to the subcellular structures. Modern investigation techniques such as the nuclear magnetic resonance spectrometry or the tubular microperfusion method with or without ion-selective micropotential measurement have opened new ways of approach and led to new recognitions concerning the function of the kidney in physiological and pathophysiological situations. To this among others belong the characterization of the tubulo-glomerular feedback and aspects of the humoral regulation of renal compensatory adaptation processes. It remains open whether in near future a new stage of experimental nephrology is beginning. It might take its starting point from the cultivation of nephronal cells and via bioartificial hybrid systems lead to new ways in simulating the tubular renal function.

Animals↗
PubMed1985

[Bacteriologic, histologic and functional studies of the kidney in 5 days' therapy of experimental E. coli pyelonephritis with gentamycin. Comparison with 9 days' therapy].

Short-term antibiotic treatment is recommended in infections of the lower urinary tract but its effectiveness is questioned in the upper urinary tract infections. We compared a 5 and a 9 day treatment of experimental E. coli 022 pyelonephritis after unilateral nephrectomy in 127 mal Wistar rats. We used 9 mg gentamycin per kg b.w. twice daily. I131 hippurat excretion was not decreased during the 5 day treatment but was only temporarily diminished during the 9 day treatment. Histologically the severe acute pyelonephritis was decreased after the 9 day treatment but not after 5 days of treatment. Bacteriologically almost all the kidneys were sterile after the 9 day treatment but the majority of the kidneys showed the injected strain of E. coli after the 5 day treatment. The results indicated that the shortened treatment was much less effective in our acute experimental pyelonephritis.

Animals↗
PubMed1985

[Kidney function and bacteriological and histological research in the therapy of experimental E. coli pyelonephritis using trimethoprim-sulfamethoxazole (TMP-SMO)].

40 uninephrectomized male Wistar rats with an experimental E.-coli-022-pyelonephritis (PN) were treated twice daily for 9 days with 30 mg trimethoprim and 150 mg sulfamethoxazole (TMP-SMO) i.p. Bacteriologically most of the kidneys became sterile. Histologically a significant reduction of the frequency of severe PN was found in the treated group. The biologic half-life of 131I-hippuran indicated a decrease of excretory function which was reversible. Urine osmolality and osmotic clearance were increased after oral water loading in 10 untreated control animals with PN but not in the treated group. The 9 day treatment had a favourable effect bacteriologically, histologically and also on renal function.

Animals↗
PubMed1979

[Treatment of experimental immune complex nephritis with indomethacin].

Functional, histological and immune-histological examination were performed in altogether 64 Wistar-rats, in order to control the effect of a therapy with 2 mg/kg per body weight indomethazine lasting 2 months at the model of an experimental immune complex nephritis. In 44 rats after presensibilisation an immune complex nephritis was performed by intraperitoneal injections with human serum albumin which were repeated three times a week. 24 glomerulonephritis animals and other 20 animals without glomerulonephritis were daily administered indomethazin through a tube probe, the remaining 20 animals with glomerulonephritis served as untreated control groups. The excretion function of the kidney was tested before the beginning of the experiment, 2 weeks after the beginning of the therapy and the regular serum injections, respectively, and before the end of the experiment by determination of the biological half-life period of 131J-hippuran. In every case one day before this the proteinuria during 24 hours was determined. At the end of the experiment the kidneys were examined histologically and immune-histologically. The results showed that indomethazin does not lead to a clear influence on the proteinuria in the immune complex nephritis of the rat. The excretion of 131J-hippuran was significantly restricted, whereas the histological and immune-histological preparations in the animals with foreign serum injections showed clear changes of the glomeruli in the sense of an early stage of the immune complex nephritis, however, they did not show any essential influence by indomethazin. That is, indomethazin had altogether no favourable effect on the immune complex nephritis of the rat.

Animals↗
PubMed1975

[Determination of kidney circulation with radioxenon].

On 23 investigations in dogs the 133xenon eluation method was compared with the bloody measurement of the renal blood supply. The most favourable correlation presents the measurement of the initial decrease of the curves with r = 0.827 and y = 0.889x + 53.3, besides the modified hight-surface-method. Possibilities of error exist especially by the recirculation of xenon and the influence on the blood supply by the xenon-injection.

Animals↗