PubMed Health⌕ Search

Biomedical subjects

R Götz

Publications and source records attributed to R Götz.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Regulation of thirst in end-stage kidney insufficiency].

About 30% of hemodialyzed patients are suffering from chronic fluid overload despite advice to restrict the oral fluid intake. To investigate the cause of the abnormal drinking behaviour a clinical study was performed in 51 non-diabetic patients with endstage renal disease exhibiting lower interdialysis weight gain (less than 3 kg, n = 17) and increased interdialysis weight gain (greater than 3 kg, n = 34). Blood pressure, body weight self-estimated thirst intensity before and after hemodialysis were analyzed. Biochemical and behavioral variables were measured including hormonal factors of water and sodium metabolism. Significant differences of dry weight, creatinine, urea nitrogen and thirst intensity were found between the two groups. Catecholamines, renin, angiotensin II, aldosterone, vasopressin and atrial natriuretic peptide exhibited a similar pattern in both groups. Atrial natriuretic peptide decreased during hemodialysis in both groups, angiotensin II, however, and norepinephrine showed an exaggerated response to ultrafiltration rate in polydipsic patients. These results suggest that changes in serum osmolality during hemodialysis did not contribute to thirst and drinking behaviour. It seems that postdialytic hypovolaemia together with higher plasma-angiotensin II-levels is responsible for increased oral intake of fluid and excessive weight gain.

Angiotensin II↗
PubMed1990

[Dilatation and balloon-expandable stents for the treatment of central venous stenosis in dialysis patients].

On 10 dialysis patients we performed 12 balloon dilatations, 2 catheter lyses, 6 stent implants (Palmaz stent) and one atherectomy of central venous stenoses or occlusions (v. subclavia, v. brachiocephalica) at the shunt arm of the patient. The primary success rate was, in balloon PTA and lysis, 12/14 interventions, and in stent placement and atherectomy 7/7. The angiographical and clinical primary result after stent implantation was significantly better than after conventional dilatation. After 66% of the balloon dilatations recidivation occurred within the first year; this can be treated by means of repeated PTA. Whether long-term exclusion of recurrence can be achieved by stent implantation, must be established by means of follow-up studies that are at present in progress.

Adult↗
PubMed1990

Impaired response to intrarenal administered atrial natriuretic peptide in ischemic acute renal failure of a transplanted patient.

A 30-year-old male patient suffering from membrano-proliferative glomerulonephritis was transplanted a cadaveric kidney 3 years ago. Five days later the transplant was removed because of fresh thrombosis in larger arteries. Three years after first transplantation a second graft was transplanted. Repeated perfusion scintigraphies of persistent anuric patient showed a delayed perfusion of renal parenchyma, no intrarenal bolus was obtained. Urgently, an arterial angiography was performed. It demonstrated that calibers of renal parenchymal vasculature were narrowed. Suggesting ischemic nature of acute renal failure, 50 micrograms human atrial natriuretic peptide (hANP) was injected intrarenally as bolus. Five minutes after hANP injection in a second angiography a significant improvement of renal blood flow was demonstrated but no amelioration of urine production or electrolyte excretion was observed. Histologically an ischemic lesion of transplant was proven. This finding indicates a blunted excretory response of acute renal failure after kidney transplantation despite of significantly ameliorated renal blood flow visualized radiologically.

Acute Kidney Injury↗
PubMed1990

Atrial natriuretic peptide reverses experimental acute renal failure induced by arginine vasopressin.

Recently, it has been reported that atrial natriuretic peptide (ANP) reverses or prevents acute renal failure induced by norepinephrine in rats. Therefore, we tested the hypothesis that vasoconstrictor doses of arginine vasopressin (VP) can induce renal ischemia and that consequent renal dysfunction is reversed by ANP infusion or bolus injections in rats. Intrarenally infused VP produced a significant decrease of glomerular filtration rate (GFR) and an increase of urinary volume and sodium excretion rate. Systemic blood pressure increased significantly during VP administration. In a second experimental period, ANP was also given intrarenally, control rats received isotonic saline solution. ANP infusion revealed a highly significant increment of GFR, urinary volume and sodium excretion. Blood pressure fell down below values of the preperiod. After cessation of ANP infusion, renal function was reduced again. These results indicate that VP induces a nonoliguric acute renal failure which is reversed by ANP infusion but only at the time of its administration.

Acute Kidney Injury↗
PubMed1990

Angiotensin-converting enzyme inhibition in renal and hypertensive disorders.

Angiotensin-converting enzyme (ACE) inhibitors have been available for about 10 years for the treatment of various forms of hypertension. Essential hypertension responds particularly well to the administration of this group of drugs, especially when combined with diuretics. A pronounced fall in blood pressure can be achieved in renovascular hypertension with high plasma renin levels; when ACE inhibitors were administered in diagnosed renal artery stenosis there was a significant rise in plasma renin activity on the affected side. Renoparenchymatous hypertension and hypertension in diabetes mellitus can also be improved by the long-term administration of ACE inhibitors, and the progression of renal failure in these disorders seems to be slowed down. Side effects such as neutropenia, exanthema, hearing disorders and pronounced hypotension with an acute deterioration in renal function are substance- and dose-dependent; regular monitoring of the patients greatly reduces their occurrence.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1989

Plasma clearance of bile acids in the rat: hepatic uptake under physiological conditions without countertransport.

Studies in rats by others indicated that sulfobromophthalein (BSP), bilirubin and indocyanine green are taken up by the liver and can be transported back to plasma against the prevailing concentration gradient (= countertransport). The present in vivo study was designed to determine whether the bile acids cholic acid and taurocholic acid under physiological conditions undergo appreciable countertransport as has been suggested by experiments in isolated hepatocytes. Experiments with BSP (controls) showed that injections of unlabeled BSP into rats five minutes after the administration of radiolabeled BSP was followed by a release of radioactivity into plasma (BSP-countertransport). In contrast bile acid countertransport could not be demonstrated, no matter whether it was tested 1, 5 or 8 minutes after the administration of radiolabeled cholic- or taurocholic acid.

Animals↗
PubMed1988

[Atypical Caroli syndrome with kidney failure in cystic renal changes].

In a 61-year-old man in terminal renal failure from bilateral renal polycystic degeneration abdominal sonography chanced to demonstrate in the left lobe of the liver a saccular, pearl string-like dilatation of the, at first no further definable, duct systems. Hepatobiliary scintigraphy revealed them to be bile-draining and thus confirmed Caroli's disease, which had previously been asymptomatic for any hepatic involvement. Since in the majority of cases of Caroli's disease renal changes are symptom-free associated findings, the question arises whether in this case there is the coexistence of polycystic renal disease and Caroli's disease or whether the biliary tract and renal changes constitute a nosological entity in the sense of atypical Caroli's disease.

Bile Duct Diseases↗
PubMed1987

Rhizobium meliloti swims by unidirectional, intermittent rotation of right-handed flagellar helices.

The 5 to 10 peritrichously inserted complex flagella of Rhizobium meliloti MVII-1 were found to form right-handed flagellar bundles. Bacteria swam at speeds up to 60 microns/s, their random three-dimensional walk consisting of straight runs and quick directional changes (turns) without the vigorous angular motion (tumbling) seen in swimming Escherichia coli cells. Observations of R. meliloti cells tethered by a single flagellar filament revealed that flagellar rotation was exclusively clockwise, interrupted by very brief stops (shorter than 0.1 s), typically every 1 to 2 s. Swimming bacteria responded to chemotactic stimuli by extending their runs, and tethered bacteria responded by prolonged intervals of clockwise rotation. Moreover, the motility tracks of a generally nonchemotactic ("smooth") mutant consisted of long runs without sharp turns, and tethered mutant cells showed continuous clockwise rotation without detectable stops. These observations suggested that the runs of swimming cells correspond to clockwise flagellar rotation, and the turns correspond to the brief rotation stops. We propose that single rotating flagella (depending on their insertion point on the rod-shaped bacterial surface) can reorient a swimming cell whenever the majority of flagellar motors stop.

Chemotaxis↗
PubMed1986

Molecular cloning of bovine and chick nerve growth factor (NGF): delineation of conserved and unconserved domains and their relationship to the biological activity and antigenicity of NGF.

Previous experiments with purified mouse and bovine nerve growth factor (NGF) have shown that the biological activities of these two NGFs are identical, whereas the immunological cross-reactivity of antibodies produced against the two NGF molecules is very limited. This observation, together with the fact that antibodies to mouse NGF do not affect the development of sympathetic and sensory neurons in chick embryos, suggests that the domain of the NGF molecules responsible for the biological action has been highly conserved during evolution, whereas other domains determining the immunological properties were under less rigorous evolutionary constraint. The nucleotide sequences of bovine and chick NGF were determined from a cDNA clone prepared from mRNA of bovine seminal vesicles and from cloned chick genomic DNA, and the amino acid sequences deduced therefrom were compared with the available sequences of mouse and human NGF. All six cysteine residues were conserved in agreement with the previous finding that the biological activity of NGF is conformation-dependent requiring intact disulfide bridges. Amino acid changes are mainly confined to hydrophilic regions expected to be potential antigenic determinants, thus providing an explanation for the poor immunological cross-reactivities between the different NGFs. One single hydrophilic region is conserved in all NGFs and this region could be involved in the biological activity. The carboxy termini of bovine and chick NGF differ from that of mouse NGF, the changes in the amino acid sequences suggest that chick and bovine NGF are probably not processed by the gamma-subunit and that no 7S complex can be formed as in the mouse submandibular gland.

Amino Acid Sequence↗
PubMed1986

Diminished parathyroid gland responsiveness to hypocalcemia in diabetic patients with uremia.

The parathyroid gland responsiveness to hypocalcemia induced by short-term calcium-free hemodialysis in patients with insulin-dependent diabetes mellitus was investigated in comparison with 10 nondiabetic uremic patients and compared with test results from the autonomic nervous system. Diabetic patients had lower C-terminal parathyroid hormone (cPTH) levels before hemodialysis than uremic control patients and showed a significantly smaller increase in cPTH during hypocalcemia. The neurological tests revealed severe disturbances of the autonomic functions in the diabetic group. In conclusion, the disturbances observed in the parathyroid secretory pattern are probably caused by gland dysfunction; it is hypothesized that the defective autonomic nervous system has an additional effect on the development of this hormonal dysfunction.

Adult↗
PubMed1986

Toxic renal failure in the rat: beneficial effects of atrial natriuretic factor.

Acute renal failure was induced in rats by intramuscular injection of glycerol. Experiments consisted of three periods: a basal infusion period for all animals, an infusion period of atrial natriuretic factor (5 micrograms or 10 micrograms/250 g body weight) in experimental rats, control rats received isotonic glucose solution, and a post-period with isotonic saline infusion in all animals. According to the severity of acute renal failure three subgroups were formed: mild, moderate, and severe acute renal failure. In all experimental rats, atrial natriuretic factor was capable of ameliorating impaired renal function, leading to increased glomerular filtration rate, diuresis and natriuresis. The effects of atrial natriuretic factor were less pronounced in severe forms of acute renal failure.

Acute Kidney Injury↗