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Biomedical subjects

J Marek

Publications and source records attributed to J Marek.

At least 127 records · Page 7Linked to original sources

The effect of experimental hyperthyroidism on renal and adrenal weight increase in mice.

The mouse kidneys are enlarged after the administration of thyroxine and this influence is not mediated through androgens. The administration of thyroxine increased the weight of the adrenals and the level of plasma corticosterone. Besides the direct effect of the thyroid hormones on the kidney, our findings indicate that the excess of triiodothyronine and thyroxine stimulates the activity of adrenals indirectly and evokes hyperadrenocorticism which could be related to the action of adrenal steroids on kidney function and kidney growth. In accordance with the above mentioned hypothesis it has been shown that aminoglutethimide, a potent blocker of adrenal steroidogenesis, decreases the level of plasma corticosterone and inhibits the enlargement of the kidney in hyperthyroid mice in spite of the high serum thyroxine values.

Adrenal Glands↗

N-acetyl-beta-glucosaminidase and albuminuria in acromegaly.

Significantly increased albuminuria and N-acetyl-beta-glucosaminidase activity in serum and urine have been observed in acromegalic patients in comparison with healthy persons (P less than 0.001). No relationship between these biochemical variables and serum growth hormone or insulin concentration was found in our group of patients. Significant correlation was determined between urinary NAG activity and albuminuria of acromegalic patients (r = 0.84).

Acetylglucosaminidase↗

Influence of testosterone isobutyrate on serum lipoproteins during replacement therapy of hypogonadal men.

Replacement therapy of hypogonadal men with testosterone isobutyrate, 100 mg by the i.m. route every two weeks, does not lead to a permanent significant change of the lipoprotein spectrum and to an increased risk of stereogenesis. The expected changes in the liver lipase activity and in the lipoprotein spectrum under the influence of the administered androgens are obviously suppressed by the antagonistic action of estrogens formed by conversion from androgens.

Adult↗

[Hormones in bone metabolism. I. Calcitropic hormones].

The review concentrates on calcitropic hormones (parathormone, calcitonin and the active metabolite of vitamin D-1,25-dihydroxyvitamin D3) and their action on bone remodeling. Attention is drawn to mechanisms of their action on the bone cell, on their manifestations in histology of osseous tissue and clinical symptomatology in pathological conditions. Attention is also drawn to the possible therapeutic application of calcitropic hormones.

Bone and Bones↗

[Hormones in bone metabolism. II. Other systemic hormones].

The authors present a review on a number of systemic hormones involved in bone metabolism. At the same time they demonstrate mechanisms of their action on the cellular, tissue and skeletal level. Attention is drawn to the participation of these hormones in the pathology of bone and other organs and the necessity to protect the skeleton during their therapeutic use in other than osteologic indications.

Adrenal Cortex Hormones↗

[Interrelation between static parameters of trabecular bones in acromegaly, the STH levels and the duration of the condition. Histomorphometric study].

To evaluate trabecular bone formations of active acromegalic patients the authors used the method of histomorphometry and correlated the calculated variables of the trabecular volume (V), osteoid volume (Vos), osteoid surface (Sf) and width of the osseous trabeculum (MTT) with STH levels, the patients' age and the period of the acromegalic process. No correlations were found between Vos, Sf, MTT and STH levels, age and the length of the case-history. There were negative correlations (p less than 0.05) between the trabecular volume (V) and the period of the case-history and trabecular volume (V) and the patients' age. From the results it may be concluded that STH does not influence the balance between resorption and formation of the acromegalic spongiosa in favour of formation.

Acromegaly↗

[Comparative histomorphometric study of acromegalic spongy bone. Formative static parameters].

The authors used static histomorphometric parameters obtained by processing of bioptic bone specimens for comparison of normal and acromegalic spongious bone. Parameters of the bone volume (V), osteoid volume (Vos), the extent of osteoid bone surfaces (Sf) in the two groups do not differ statistically. The two groups do not differ as to age distribution. The width of bone trabeculae is greater in acromegalic bone; the difference as compared with normal bone specimens is statistically significant (p less than 0.05). The authors conclude that STH in acromegalics subjects does not stimulate osteoid production in trabecular bone to shift the balance between bone resorption and formation significantly in favour of formation. Only restructuring of trabecular acromegalic bone occurs.

Acromegaly↗

[The effect of dopamine on hemodynamic and hormonal parameters in liver cirrhosis].

To 11 patients with liver cirrhosis (5 with ascites) and 6 controls a one-hour dopamine infusion, 1.5 micrograms/kg/min., was administered. In all before administration of the infusion catheterization of the hepatic veins and lesser circulation was performed with concurrent assessment of the cardiac minute volume by thermodilution, and haemodynamic measurements were repeated also after the dopamine infusion. Before the dopamine administration and after termination of the infusion the plasma renin activity was assessed (PRA), plasma aldosterone, the atrial natriuretic factor (ANF), prolactin and in some patients also plasma catecholamines. Dopamine administration was not associated with an increase of the cardiac output, heart rate or peripheral resistance; the infusion had only purely dopaminergic effects. Plasma prolactin declined after dopamine administration significantly in controls (from 29.17 +/- 7.01 to 11.83 +/- 3.22, p less than 0.05, in patients with liver cirrhosis without ascites) from 18.16 +/- 2.44 to 8.64 +/- 2.01, p less than 0.01) in patients with ascites liver cirrhosis (from 23.5 +/- 9.3 to 15.2 +/- 7.47, p less than 0.05). In the controls after the dopamine infusion PRA suppression occurred (from 2.37 +/- 0.81 to 0.9 +/- 0.27, p less than 0.05), while in patients with compensated liver cirrhosis (from 0.97 +/- 0.41 to 0.85 +/- 0.34, n.s.) and in patients with decompensated liver cirrhosis the PRA did not change significantly either (from 4.56 +/- 1.67 to 5.065 +/- 2.29, n. s.). After the dopamine infusion in none of the investigated patient groups changes of plasma aldosterone and ANF were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗

[Can atrial septal defects be reliably diagnosed by echocardiography?].

The diagnostic reliability of echocardiography (ECHO) was analyzed in a group of 179 children operated on account of an atrial septal defect (ASD) and partial anomalous pulmonary venous drainage (PAPVD). A total of 223 individual types of ASD and PAPVD and their mutual combinations were proved on operation. In all patients indirect signs of a left-to-right shunt at the atrial level was proved. The sensitivity and specificity of ECHO examinations in the ASD type fossa ovalis was 0.97 and 0.80 resp., in ASD type sinus venosus it was 0.47 and 0.98, in PAPVD 0.38 and 0.99. In both types of ASD type sinus coronarius assessed on operation the ECHO diagnosis was correct. The application of colour Doppler technique increased the reliability of the ECHO examination. The accuracy of ECHO in ASD and PAPVD depends indirectly on age, body weight and body surface. No relationship was proved between reliability of ECHO diagnosis of the defect and the magnitude of the left-to-right shunt assessed by radiocirculography and the size of the defect assessed during operation. In no instance the diagnostic inaccuracy affected the surgical approach and the result of the operation. Despite certain diagnostic pitfalls, it is therefore possible to operate, using the comprehensive non-invasive examination procedure, children with these anomalies in our department without previous cardiac catheterization and angiography.

Adolescent↗

Bronchial anomaly of the right upper lobe.

This case report presents a rare anomaly of right upper lobe bronchial anatomy. During routine right upper lobe resection for carcinoma, a common right upper and middle lobe bronchus was found. The resection was completed as a right upper and middle bilobectomy. Knowledge of this uncommon variant was beneficial in performing the pulmonary resection. A review of the literature is presented.

Adenocarcinoma↗

Cardiomyopathy and changes of skeletal muscles in cystic fibrosis.

Cardiomyopathy (CMP) was found in 26 children with cystic fibrosis (CF), 24 of them died, the majority of them during the first 3 years of life. Only 4 of them were older than 10 years. 2 children are living. CMP must be suspected in young children with CF and early heart failure. When CMP is the cause of sudden death, CF has to be suspected. The combination of changes in skeletal and cardiac muscles in CF is reported here for the first time.

Cardiomyopathies↗

[Removal of pulmonary metastases using the Nd:YAG laser].

The authors submit a case-history on their first successful application of a Nd:YAG laser in pulmonary surgery. They operated a 17-year-old boy with metastases of a synovial sarcoma in both wings of the lungs. First the boy was operated on the left side by the classical technique, half a year later the authors used a Nd:YAG laser on the right side. By means of the laser four metastases were removed. The postoperative course was without complications. One month after operation the patient was discharged from the care of oncologists and was free of complaints. The authors compare the surgical techniques and the postoperative course of the patient. A Nd:YAG laser is a suitable supplement of the equipment of pulmonary surgeons. Since the described case the authors used the laser in same indication in another three patients.

Adolescent↗

[Echocardiographic diagnosis of aortic coarctation in neonates and infants].

Based on experience with the examination of 78 children under one year with coarctation of the aorta the authors present an account of basic echocardiographic examination procedures and findings in this defect. Two-dimensional echocardiography revealed in 98.8% of the patients a reduced pulsation of the abdominal aorta, as compared with the pulsation of the ascending aorta. In all instances it proved possible to visualize the coarctation. Pulsed Doppler echocardiography proved an abnormal flow in the abdominal aorta in 89.7% children; at the site of coarctation in 96.1% a typical saw-like flow with an acceleration typical for the flow in a stenotic vessel. Hypoplasia of the aortal arch was recorded in 51.3%, a patent ductus arteriosus in 73.2% of the children. An anomaly of the aortal valve was found in 57.7%, obstruction of the left ventricular, outflow tract in 35.9% children. An anomaly of the mitral valve was present in 23.2% children. M-mode echocardiographic findings proved enlargement of the right ventricle and hypertrophy of its wall. The size of the left ventricle and thickness of its wall differed less from normal values. The width of the aortal root was smaller than in a group of normal patients, the left atrium was enlarged. A combination of echocardiographic methods makes reliable non-invasive diagnosis of coarctation of the aorta in neonates and infants possible, as well as the evaluation of associated defects and indication for operation without the application of invasive methods.

Aortic Coarctation↗

[Surgical treatment of congenital vascular anomalies causing tracheoesophageal compression].

Forty four children underwent surgery for congenital vascular anomalies causing tracheal compression in Kardiocentrum--Motol during last ten years. Double aortic arch was encountered 18 times, tracheal compression by the innominate artery in 12 instances, right aortic arch with left ligamentum arteriosum and possibly aberrant left subclavian artery 7 times, pulmonary artery sling in 5, finally aberrant right subclavian artery twice. The age of the children was 2 weeks to 11 years (median 6 months). Stridor was present in 38 infants under 3 months, 17 children with severe dyspnoea had artificial ventilation or were resuscitated or hospitalized at the intensive care department. In four an associated cardiac defects was present. The diagnosis was made by oesophagography, echography, laryngotracheoscopy, in the majority of children it was confirmed by angiography of the sometime with tracheobronchography. The operation was performed in 41 children from left-sided thoracotomy, the vascular ring was released by resection or retraction of the compromising vessel and connective tissue from the trachea. Serious stenosis of the distal trachea in one patient found before operation persists one year after operation, the patient breathes through an individual tracheostomic cannula. Four children could not be extubated for prolonged periods after operation, they were re-operated, the annulus was released. Three patients died, one from bronchopneumonia during the postoperative period, the second one from hypoxic brain damage and the third one after operation of a complex heart disease. In 40 children satisfactory long-term results were achieved, the operation resolved respiratory complaints. The prerequisite of satisfactory results in an accurate diagnosis, early indication of the operation and a perfect surgical operation and good postoperative care.

Aorta, Thoracic↗

The subrenal capsule assay in immunocompetent mice--the inevitable role of histopathology in assessment of this method as a tool determining tumor sensitivity to cytostatic drugs.

The subrenal capsule assay (SRC) in immunocompetent mice became one of commonly used approaches to evaluating the efficiency of cytostatic therapy. A comparison of the classical macroscopic evaluation according to the Bogden diagram with results of the histopathologic examination in 118 mice with implanted Yoshida sarcoma or human rectal adenocarcinoma demonstrated the tumor to be present to different extent only in 26 out of 50 macroscopically positive cases and, on the other hand, it was found in 3 out of 68 macroscopically negative animals. Histological changes in these cases, as well as a study of the dynamics of the development of histopathologic changes after tumor implantation and the changes after implantation of inert materials demonstrated that the resorptive and reparative granuloma, originating in immunocompetent mice under the renal capsule after implanting the tumor or other materials, simulates perfectly the growth of the tumor infiltrate. For this reason we consider this method in immunocompetent mice as unreliable when there is no parallel histological examination.

Animals↗

[Echocardiographic diagnosis of interrupted aortic arch in a group of 13 patients (children)].

Based on experience with the examination of 13 children with interruption of the aortal arch (IAA) the authors present an account of the basic echocardiographic (ECHO) diagnostic signs and procedures in IAA. Two-dimensional ECHO makes it possible, when a suprasternal approach is used, to assess the type of IAA. Examination from a subcostal and parasternal approach helps to detect associated heart diseases. ECHO findings correlated with angiocardiographic, surgical and necrotic findings. ECHO makes it possible to select further suitable examination methods and therapeutic procedures in this rare critical congenital heart disease.

Aorta, Thoracic↗