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Biomedical subjects

E Heidbreder

Publications and source records attributed to E Heidbreder.

At least 73 records · Page 4Linked to original sources
PubMed1985

Disturbances of peripheral and autonomic nervous system in chronic renal failure: effects of hemodialysis and transplantation.

Investigations of peripheral and autonomic nervous system functions were performed in 37 healthy persons, 66 patients with chronic renal failure (31 undialyzed patients, 35 dialyzed patients) and in 18 transplanted patients. The study resulted in disturbances of nerve conduction velocity and pallesthesia in predialysis and hemodialysis patients. After the transplantation, an amelioration of peripheral nerve function was observed. A set of autonomic tests demonstrated vagally mediated disorders in the predialysis group. The sympathetic function was hardly affected. In dialysis group as well as in transplanted patients a significant improvement of parasympathetic dysfunction was observed. We conclude that disorders to the autonomic nervous system in chronic renal failure are characterized by reversible vagal changes, while disorders of peripheral nervous system are resistant to hemodialysis therapy.

Adult↗
PubMed1984

Granulocyte lysosomal factors and plasma elastase in uremia: a potential factor of catabolism.

In uremic intoxication proteolytic activity in plasma and striated muscle is enhanced. To get further insights into the underlying mechanisms the lysosomal factors of polymorphonuclear (PMN) leukocytes and the plasma elastase-alpha 1-proteinase inhibitor complex were investigated in patients with acute and chronic renal failure. Lysosomal activity was evaluated in peripheral blood smears by the lysis of erythrocytes and plasma (halo formation) around each neutrophil induced by 0.25 M NaC1 borate buffer. In about half of the patients with chronic renal insufficiency on dietary treatment lysosomal activity of PMN leukocytes was reduced. The plasma concentration of elastase-alpha 1-proteinase inhibitor complex was normal in most subjects, but increased in three patients with the highest serum creatinine levels (greater than 13 mg/d1). In the patients with acute renal failure (ARF) of various origin (postoperatively, septicemia, pancreatitis, or dye-induced) halo formation was either reduced or absent. The plasma elastase-alpha 1-proteinase inhibitor complex was increased in 5/6 of the patients by a factor of two to four. Also in the patients on regular hemodialysis treatment halo formation of PMN leukocytes was substantially reduced, whereas the plasma levels of elastase-alpha 1-proteinase inhibitor complex was slightly increased. The finding of reduced lysosomal activity of PMN neutrophils in uremia may be partly due to an enhanced release of neutral proteinases into the circulation as indicated by the elevated plasma levels of elastase-alpha 1-proteinase inhibitor complex in some patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1984

Release of granulocyte neutral proteinases in patients with acute and chronic renal failure.

In uremic intoxication proteolytic activity in plasma and striated muscle is enhanced. To get further insight into the underlying mechanisms the neutral proteinases of polymorphonuclear (PMN) leukocytes were investigated in patients with acute and chronic renal failure. The following studies were performed: 1. Neutral proteolytic activity of PMN neutrophils in blood smears (according to Klessen, 1978). 2. Serum levels of elastase alpha 1 proteinase inhibitor complex (Neumann et al., 1981). In about half of the patients with chronic renal insufficiency on dietary treatment the proteolytic activity of PMN leukocytes (halo formation are due to digestion of erythrocytes and plasma) was reduced. The serum concentration of elastase alpha 1 proteinase inhibitor complex was normal in most subjects, but increased in 3 patients with the highest serum creatinine levels (greater than 13 mg/dl). In the patients with acute renal failure (ARF) of various origin (postoperatively, septicemia, pancreatitis or dye induced) halo formation was either reduced or absent. Serum elastase alpha 1 proteinase inhibitor was increased in 5/6 patients by a factor of two to four. Also in the 15 patients on regular hemodialysis treatment halo formation was substantially reduced, while the serum levels of elastase alpha 1 proteinase inhibitor complex was slightly increased. The finding of reduced proteolytic activity of PMN neutrophils in uremia is probably due to an enhanced release of proteinases into the circulation as indicated by the elevated serum levels of elastase alpha 1 proteinase inhibitor complex in some patients. The release of proteinases might be in part due to the effect of "uremic toxins". In the RDT patients the contact of the blood with the dialyzer (cuprophane) membrane might be an additional factor. In the patients with ARF the underlying disease (infection, shock, trauma) contributes to the release of proteinases. These disturbances may be harmful for the patient, if the blood concentration or function of the most important proteinase inhibitors (alpha 1 proteinase inhibitor, alpha 2 macroglobulin) is reduced.

Acute Disease↗
PubMed1984

[Connatal ptosis: a symptom of the syndrome of multiple pterygium and arthrogryposes].

Report on a 56-year-old female exhibiting features of the multiple pterygium syndrome, e.g., puffiness and ptosis of the upper lids, hypertelorism, pterygium of the metacarpophalangeal joints, hypomobility of joints, short stature, obviously inherited as an autosomal recessive trait. In differential diagnosis distal arthrogryposis has to be considered. It is not known whether the intravitreous hemorrhage from which this patient suffered is associated with the disorder.

Arthrogryposis↗
PubMed1984

Psychomental stress in tetraplegic man: dissociation in autonomic variables and emotional responsiveness.

Tetraplegic patients with physiologically complete cervical spinal cord transsection are classic ablation models of sympathetic denervation. Therefore this study was conducted to investigate the hemodynamic response (blood pressure, cardiac rate) and the plasma catecholamine (adrenaline, noradrenaline) release induced by a standardized psychomental stress model (sonic confuser). Attention was focussed on subjective evaluation of stress experience in spinal man. During psychomental stress, typical pressure reaction was not observed, cardiac rate was elevated insignificantly, and catecholamine release was diminished. The subjective estimates of stress experience, however, did not differ from those of the control group. It appears that psychomental stress in sympathectomized man is not extinguished despite abolished peripheral autonomic feedback modifying the state of the central nervous system. Cognitive processes and cortical arousal seem to be the initial and important steps of emotional experience and they are independent from peripheral autonomic processes. These results lend support to the centralistic view of emotions and the importance of cognitive factors in emotional responsiveness.

Adult↗
PubMed1983

[Hypocalcemia in malignant diseases].

Hypercalcemia accompanies often malignant diseases. The majority of cases of malignancy complicated by hypercalcemia is induced by metastases involving bone, hypercalcemia may also accompany localised tumors. Various hormones have been implicated in the genesis of malignant hypercalcemia: ectopic secretion of parathyroid hormone by tumor or orthotopic secretion by concomitant primary hyperparathyroidism, prostaglandin activating osteoclasts, production of hypercalcemic factor other than these hormones. This review summarizes current knowledge about endocrine-mediated mechanisms which produce hypercalcemia and about its frequency and mechanism in different types of tumors.

Adrenal Gland Neoplasms↗
PubMed1983

[Calcium antagonists in the therapy of hypertension].

Calcium antagonists (nifedipine, verapamil, diltiazem) are potent vascular smooth muscle relaxants. Experimental and clinical investigations provide growing evidence that they are effective in acute and (sub)chronic therapy of arterial hypertension by lowering peripheral vascular resistance and improvement of altered hemodynamics--independent from pathogenesis of hypertension. Due to its prompt and profound hypotensive action, sublingual or oral nifedipine has been used successfully in hypertensive crises. The hypotensive effect usually correlated closely with the severity of hypertension and is nearly absent in normotensive controls. Since the blood pressure drop may occasionally results in absolute or relative hypotension, the initial dose should be as low as possible. The activation of the adrenergic and renin angiotension systems seen after nifedipine administration is less pronounced after chronic administration of the drug and is nearly absent after verapamil and diltiazem. Plasma aldosterone concentrations remain constant or are slightly decreased. In contrast to classic vasodilators, the long-term administration of calcium antagonists usually does not result in tachycardia (nifedipine), but slight sinus bradycardia (verapamil, diltiazem). Peripheral edema may occasionally occur after nifedipine. A tolerance has been observed during long-term treatment of hypertension. Combining these drugs (verapamil, diltiazem) with betablockers is not recommended due to the negative inotropic and bathmotropic effects. Simultaneous administration of nifedipine and beta-blockers enhances the hypotensive action, but favours the development of peripheral edema and in rare cases (especially in severe coronary heart disease) results in a dramatic drop in blood pressure and/or congestive heart failure. Further clinical evaluation and long-term trials of calcium antagonists as antihypertensive agents will be needed before definite conclusions can be drawn.

Biological Transport↗
PubMed1983

Effect of diuretics and calcium antagonists on circulatory parameters and plasma catecholamines during mental stress.

In a model of mental stress the influence of nifedipine and hydrochlorothiazide on stress-induced changes in blood pressure, heart rate, and plasma catecholamines was studied in normal persons. The drugs were used to investigate whether substances with antihypertensive but no particular sympatholytic properties were capable of suppressing emotionally induced stress reactions. In all subjects blood pressure and heart rate increased significantly during mental stress, and this effect was not inhibited either by nifedipine or hydrochlorothiazide. In the hydrochlorothiazide group plasma noradrenaline levels were significantly higher than in controls in the resting state and during the stress reaction, whereas in the nifedipine group no difference was observed. It is concluded that nifedipine or hydrochlorothiazide do not inhibit emotional stress reactions in normotensive persons.

Adult↗
PubMed1983

Proteolytic enzymes and catabolism: enhanced release of granulocyte proteinases in uremic intoxication and during hemodialysis.

Proteinases are classified into four groups according to their catalytic mechanisms: the serine, cysteine (thiol), aspartic (carboxyl), and metallo-proteinases. Neutrophil granulocytes contain a variety of neutral proteinases and two acid proteinases. Lysosomal proteinases are released from cells during phagocytosis, cell death, or exposure to antigen-antibody complexes, complement factors, and toxins. Under pathological conditions, massive proteinase release may cause tissue injury and degradation of plasma proteins. Plasma proteolytic activity is controlled by inhibitors of blood systems (antithrombin III, C1 inhibitor, and plasmin inhibitor) and by inhibitors against proteinases of various body cells (alpha 1-proteinase inhibitor, alpha 1-antichymotrypsin, beta 1-collagenase inhibitor, and inter-alpha-trypsin inhibitor). Intracellular proteinases are controlled by different cytosolic inhibitors. In hypercatabolic states (septicemia, trauma, burns), the concentrations of many plasma proteins, including proteinase inhibitors, are decreased. Kallikrein-kinin, complement, and fibrinolytic systems may be activated, probably due to enhanced proteinase activity. In acute renal failure, there is a release of granulocyte neutral proteinases. The plasma concentration of the elastase-alpha 1-proteinase inhibitor complex is simultaneously increased. Granulocytes of chronically uremic patients treated with diet or regular dialysis have a slightly to markedly reduced proteinase content as compared with normal controls. There is a dramatic rise of the plasma elastase alpha 1-proteinase inhibitor complex during hemodialysis treatment.

Acute Kidney Injury↗
PubMed1982

Circulatory changes during mental stress in tetraplegic and paraplegic man.

In ten patients suffering from complete chronic cervical spinal cord lesion, the effect of mental stress was studied. Before, during and after stress, variations of blood pressure, heart rate and plasma catecholamines were tested. The study showed a loss of hemodynamic reactions under mental stress in tetraplegics, namely the pressure response, the typical increase in heart rate and in plasma noradrenaline and adrenaline. It is concluded, that changes in sympathectomized man interfere with the acute hemodynamic stress reaction and impair the blood pressure homeostasis.

Adult↗
PubMed1981

[Stress, emotion and hypertension: the integrative role of central nervous system (author's transl)].

In current literature stress is assumed to be of important factor in the multifactorial pathogenesis of hypertension. The cardiovascular response might be dependent on the type and severity of stressors, the complexity of stress reaction and the ability of man to counteract stress. In this review the concept of stress, its nature and the participation of the central nervous system are elucidated. The role of emotion is also discussed, as well as a connection to stress mechanisms. The sympathetic nervous system acts as link between stress and hypertension, especially borderline-hypertension. Based on various experimental models as well as epidemiological investigations the hypothesis that stress is a causative factor in the initiation of hypertension is critically discussed. In patients with a genetic predisposition to hypertension, stress may play an important role in early manifestations of chronic blood pressure elevation, and in established hypertension, however, psychological stress contributes to temporary or longer lasting increases of blood pressure.

Animals↗
PubMed1980

[Toxic nephropathies (author's transl)].

Direct tubular damage, hypersensitivity reaction, metabolically mediated kidney disturbances, and chronic nephropathies are important sequelae of several drugs or their metabolites. In this review the drug-induced kidney disease is discussed from a clinical, histological, and pathogenetic point of view. The knowledge of possible nephrotoxic reactions and their underlying toxins are essential for prevention of this kidney disease.

Analgesics↗
PubMed1980

Effect of guanfacine on vigilance.

1. In 20 patients suffering from mild hypertension (WHO classification I-II) the effect on vigilance was studied under double-blind conditions. Ten patients were given guanfacine 2 mg daily and ten others a placebo preparation. 2. Before the study and following 2 weeks' medication a battery of tests was applied in which the reaction time and attention were subjected to comparative analysis. The variation in blood pressure and heart rate under mental stress conditions was also tested. 3. The study shows a non-significant reduction in blood pressure in the guanfacine group without the parameters of vigilance being affected. Under mental stress, there was no impairment of haemodynamic reactions. 4. It is concluded that guanfacine, at the selected dose of 2 mg daily, has no apparent effect on the vigilance of hypertensive patients.

Adult↗