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Biomedical subjects

K Ehlenz

Publications and source records attributed to K Ehlenz.

32 records · Page 2Linked to original sources
PubMed1992

[Osteoporotic vertebral fractures in systemic mastocytosis without skin involvement].

Radiological investigation of the vertebral column in two patients with low-back pain (53-year-old woman and a 52-year-old man) revealed unusually marked osteoporosis and sintering fractures of the 3rd, and 1st and 4th lumbar vertebrae, respectively. Biochemical tests failed to provide any evidence about metabolic or endocrinological abnormality. Iliac crest biopsy showed mastocytosis. There were no skin changes in either patient. Additional examinations excluded involvement of any internal organs. Despite treatment with calcium, sodium fluoride, vitamin D3 and calcitonin in the woman, and aspirin and chromoglycinic acid in the man the osteoporosis has slowly progressed during the last 7 and 5 years, but the disease has remained limited to the skeletal system. In a case of unusually marked osteoporosis, mastocytosis should be included in the differential diagnosis even in the absence of urticaria pigmentosa.

Aspirin↗
PubMed1991

Reduction of nocturnal diuresis and natriuresis during treatment of obstructive sleep apnea (OSA) with nasal continuous positive air pressure (nCPAP) correlates to cGMP excretion.

In ten patients with severe obstructive sleep apnea (OSA) profound changes in renal function could be demonstrated at night during nCPAP therapy. Natriuresis and diuresis decreased by about 50% while creatinine excretion rate and urinary osmolality did not change. We found parallel changes in the excretion of ANP's second messenger cyclic guanosine monophosphate (cGMP) in a dose-response-related manner to natriuresis respectively diuresis. These data are in agreement with recently demonstrated decrease of nocturnal plasma levels of atrial natriuretic peptide (ANP) during nCPAP therapy in apneic patients. This may be an indicator for an increased cardiac volume load during obstructive apnea. The decrease of diuresis, natriuresis and cGMP excretion demonstrate the beneficial effects of nCPAP treatment on the cardiovascular system. Therefore measurements of cGMP excretion may be a useful parameter to assess the cardiovascular function of apneic patients before and during treatment.

Adult↗
PubMed1991

[Adrenomyeloneuropathy as a cause of Addison's disease].

A 25-year old male, with a 3-year history of spastic paraparesis and a disturbance of bladder emptying, developed Addison's disease (plasma ACTH 1250 pg/ml, depressed cortisol values with loss of diurnal rhythm, potassium 6.8 mmol/l, sodium 123 mmol/l) associated with a urinary tract infection. The suspected diagnosis of adrenomyeloneuropathy was confirmed by the finding of raised plasma long-chain fatty acid concentrations. The patient was immediately given 0.4 mg fludrocortisone as a bolus, followed by 0.1 mg daily maintenance therapy, the urinary tract infection having already been successfully treated. Substitution therapy with hydrocortisone was also initiated (starting dose 30-20-10 mg daily, maintainance dose 20-10-5 mg daily). As a result, the electrolyte concentrations returned to normal and the neurological features improved. A family study was undertaken to determine whether the adrenomyeloneuropathy was an X-linked recessive form. Both the symptom-free mother (carrier) and the 19-year-old brother, who had suffered from Addison's disease since the third year of life, had raised plasma long-chain fatty acid concentrations. Both brothers were started on a diet low in long-chain fatty acids. Estimation of long-chain fatty acids is indicated in boys or young adult males with peripheral neuropathy or Addison's disease of uncertain aetiology.

Addison Disease↗
PubMed1991

Disturbances in volume regulating hormone system--a key to the pathogenesis of hypertension in obstructive sleep apnea syndrome?

Recent studies about renal function and volume regulating hormones in obstructive sleep apnea (oSAS) indicate complex disturbances in volume homeostasis. Increased nocturnal secretion of atrial natriuretic peptide (ANP) and decreased renin secretion during apnea looks similar to a situation seen during hypervolemia or increased cardiac volume load. Increased venous return induced by pathologically high negative intrathoracic pressure during obstructive apnea may be the cause. Since during wakefulness no true hypervolemia is present, a "pseudohypervolemia" or "central hypervolemia" must exist caused by volume shift from the peripheral to the central compartment during apnea. Since volume homeostasis and blood pressure regulation are complexly connected the question arises whether disturbances in volume homeostasis play a role in the pathogenesis of arterial hypertension in sleep apnea. In a subgroup of hypertensive patients hypertension is salt-sensitive and volume dependent; it is called volume-expanded or low-renin hypertension. An inhibitor of the Na+/K(+)-ATPase acting via the digitalis receptor - called digitalis like factor (DLF) - is regarded as the causative agent for the development of hypertension in these cases. From this background, we were interested in the question whether DLF may be the linkage between disturbances in volume homeostasis and the pathogenesis of hypertension in sleep apnea. We could demonstrate a decrease of nocturnal urinary excretion of DLF during nasal continuous positive air pressure (nCPAP) therapy. Since a positive correlation between changes in diuresis respectively natriuresis and DLF excretion was found, we suggested DLF to be involved in changes of renal function in sleep apnea besides ANP. In 3 patients we measured nocturnal plasma levels of DLF and renin.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Natriuretic Factor↗
PubMed1991

[Serum endothelin in patients with Raynaud syndrome before and following cold provocation].

To determine wether there is a pathogenetic effect of endothelin (ET) in vasoconstriction in Raynaud's phenomenon, plasma-endothelin and it's association to extent of vasoconstriction was measured before and after digital cooling. Only in cases with massive vasoconstriction ET rose significantly after cooling. In conclusion ET seems to be involved in the pathogenesis of RS, whereas the exact pathomechanism remains unclear.

Cold Temperature↗
PubMed1990

Normolipemic dysbetalipoproteinemia and hyperlipoproteinemia type III in subjects homozygous for a rare genetic apolipoprotein E variant (apoE1).

A family with three heterozygote and two homozygote carriers of the rare apolipoprotein E1 isoform was detected by isoelectric focusing. One of the homozygous patients had type III hyperlipidemia, while the other showed normolipemic dysbetalipoproteinemia. Restriction fragment length analysis as well as allele specific oligonucleotides were used to identify the structural alterations forming the abnormal epsilon 1 genotype. Comparison with the most common epsilon 3 allele showed that two base exchanges A for G in codon 127 and T for G in codon 158 (Asp for Gly and Cys for Arg, respectively) are responsible for the amino acid substitution which causes the charge shift observed in isoelectric focusing. The same defects have been described in the only previously characterized apoE1 (Weisgraber et al. 1984. J. Clin. Invest. 73: 1024-1033). In addition to the study by Weisgraber and coworkers, who reported on a heterozygous patient, we here describe the metabolic and clinical consequences of a homozygosity for this rare allele. Changes in lipoprotein metabolism, as well as in clinical phenotypes, were exactly identical to those seen in patients homozygous for the epsilon 2 allele, which has in common with the epsilon 1 allele the mutation in codon 158, but lacks the substitution in codon 127. In addition, lipoprotein profiles of the epsilon 3/epsilon 1 heterozygotes were indistinguishable from those of epsilon 3/epsilon 2 heterozygotes. Therefore, we conclude that the additional mutation in codon 127 that characterizes the epsilon 1 allele is of no functional importance in vivo.

Adolescent↗
PubMed1989

Modulation by somatostatin of nerve-mediated activation of glycogenolysis in the perfused rat liver.

Perivascular nerve stimulation of rat livers perfused in situ with erythrocyte-free Krebs-Henseleit buffer at constant pressure in a non-recirculating system resulted in an increase of glucose and lactate production and in a decrease of portal flow. Infusion of somatostatin in different concentrations (2 x 10(-7), 10(-8), 10(-9) mol.l-1) reduced the nerve-mediated activation of glucose release maximally to 66%. There was only a slight effect on the lactate output, the nerve-mediated reduction of portal flow was unaltered. In controls, somatostatin alone had no effect on the metabolic and hemodynamic parameters. In order to differentiate between a presynaptic and postsynaptic mechanism, the noradrenaline overflow was calculated. The unaltered release of the neurotransmitter in the presence or absence of somatostatin excluded a presynaptic mechanism. To mimic the nerve effects on the carbohydrate metabolism and on the hemodynamics, noradrenaline (2 x 10(-7) mol.l-1) was infused instead of the nerve stimulation over a period of 5 min. Somatostatin did not change the endocrine effects of the catecholamine under these conditions. The nerve-dependent effect of somatostatin suggests that other neurotransmitters (e.g. VIP) or mediators (e.g. prostanoids) may be influenced by somatostatin.

Animals↗
PubMed1989

Role of circulating catecholamines in the control of pancreatic polypeptide and gastrin release.

The influence of circulating catecholamines on the release of pancreatic polypeptide (PP) and gastrin was studied in volunteers. Physical exercise increased plasma epinephrine by 374 +/- 123% and plasma norepinephrine by 167 +/- 30%, but plasma PP concentrations remained unchanged during standardized bicycle ergometry. Immediately after cessation of exercise catecholamine levels decreased rapidly, whereas PP concentrations increased by 55%. In a second series, epinephrine infusion (5, 25, and 75 ng.kg-1.min-1) increased epinephrine levels by 38 +/- 12, 331 +/- 69, and 1229 +/- 131%, respectively, whilst norepinephrine was unaffected. Neither during nor after catecholamine infusion PP secretion was affected. Gastrin release increased by a maximum of 85 +/- 38% (at epinephrine 75 ng.kg-1.min-1). It is concluded, that (1) changes in circulating adrenaline do not significantly influence PP secretion in man; (2) the PP increase immediately following physical exercise cannot be attributed to a rapid fall of catecholamine levels; (3) endogenous catecholamines are of minor importance in the control of gastrin secretion.

Adult↗
PubMed1989

[Does determination of atrial natriuretic factor have significance in the assessment of cardiac stress in apnea in sleep apnea patients?].

It has long been known that the heart is involved volume regulation. This fact took on new importance when, in 1981, de Bold discovered the existence of ANF. Apnea-associated cardiovascular changes make the treatment of apnea necessary to prevent the occurrence of cardiovascular sequelae. What is needed, however, is a parameter which, non-invasively, reflects both the cardiac loading during apnea and effects of treatment. Krieger succeeded in demonstrating that the commonly observed nycturia regresses under nasal cPAP therapy. This prompted us to consider whether the ANF factor might not be involved. In an attempt to find an answer, we have, up to now, investigated six patients prior to and during nCPAP therapy. On the basis of the results we obtained, the following conclusions may be drawn: 1. During apnea, the patients show sometimes dramatic increases in ANF plasma levels. 2. Under nasal CPAP treatment, these elevated levels decrease again, in some cases by as much as 50%. 3. The ANF plasma level correlates with pulmonary arterial pressure. This suggests to us that ANF determination is of importance for the assessment of cardiac loading during apnea, and represents a parameter that reflects the effects of therapy.

Atrial Natriuretic Factor↗
PubMed1986

Hormonal and cardiovascular variations during a public lecture.

A long-time electrocardiogram over a period of 12 h was recorded from ten test persons without cardiovascular diseases, and their blood pressure was checked at regular intervals on the day of a public speech. In order to determine plasma concentrations of epinephrine, norepinephrine, cortisol, human growth hormone (hGH), prolactin and gastrin, blood samples were taken from the subjects by inserting a venous catheter in the morning. The levels of epinephrine, norepinephrine and cortisol were also examined in urine collected from the volunteers. During the public speech there was a distinct increase in blood pressure and pulse rate. Epinephrine and cortisol showed the clearest increase in serum and collected urine, whereas norepinephrine, prolactin, hGH and gastrin reacted less strongly. The epinephrine/norepinephrine ratio value is discussed as a parameter for psychomental and emotional strain.

Adult↗
PubMed1984

[Sex hormones and fertility following portacaval anastomosis in rats].

Portocaval anastomosis (PCA) in the normal male rat causes profound alterations in testicular morphology and function and in plasma levels of sex steroids as well as of gonadotropins. Testicular atrophy is accompanied by a significant decrease of plasma testosterone (0.03 ng/ml versus 0.99 ng/ml) and an increase of estradiol (76.2 pg/ml versus 39.7 pg/ml) and estrone (68. pg/ml versus 45.5 pg/ml). Plasma levels of gonadotropins (LH, FSH) and prolactin are lowered too (LH: 15 ng/ml versus 28.5 ng/ml, FSH:119 versus 182 ng/ml, prolactin:53 versus 109 ng/ml). The altered sex hormone metabolism is reflected in marked changes of the morphology and nucleic acid content of the metabolizing organs i.e. liver, gonades and kidney. The results of this study are consistent with the hypothesis that portosystemic shunt per se plays an important role in the pathogenesis of the disturbed metabolism of sex hormones observed in patients with liver cirrhosis and portal hypertension.

Adrenal Glands↗