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Biomedical subjects

J Simek

Publications and source records attributed to J Simek.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Serum selenium levels in the population of four regions in southern Moravia].

The paper deals with the problem of selenium in the food chain of man. The authors investigated the serum selenium concentration of healthy blood donors in four South Moravian regions. Consistent with other authors they found a marked deficiency of this element. While optimal values in analyzed samples were found in 11% in the Trebíc area, 5% in the Vyskov and Brno area, in the Znojmo area no specimens belonging in that group were found. Based on the assembled results the authors consider 22% of the South Moravian population selenium deficient. With regard to this finding it would be useful to modify the therapeutic pattern in some serious conditions. The question remains what to do for the general population. There are several possibilities: adding selenium to fertilizer leading to higher contents in food, administration of selenium preparations, mixing agricultural products containing high and low selenium concentration and finally complete knowledge of selenium metabolism.

Adolescent↗
PubMed1997

[Valve replacement in congenital aortic stenosis].

BACKGROUND: Hemodynamically significant congenital aortic stenosis is usually surgically solved by valvotomy, infrequently aortic valve replacement is necessary. The aim of this retrospective study (period 1979-1995) is to find reasons for valve replacement, frequency of these procedures and early and long term results after aortic valve replacement for congenital aortic stenosis. METHODS AND RESULTS: Congenital aortic stenosis was solved by aortic valvotomy in 82 patients and by aortic valve replacement in 18 patients. Aortic valve replacement was performed 6x for congenital valvar aortic stenosis with mean aortic gradient 53.7 +/- 13.9 mm Hg and aortic valve area 0.42 +/- 0.04 cm2/m2 and 4x for valvar and subvalvar stenosis with mean aortic gradient 87.0 +/- 31.3 mm Hg, valve area 0.45 +/- 0.03 cm2/m2 and associated regurgitation 44.7 +/- 25.6%. In the remaining 8 patients aortic valve replacement was performed as reoperation after aortic valvotomy (after 20 +/- 8.4 years). In this group mean aortic gradient was only 32.2 +/- 13.8 mm Hg but regurgitation was 54.0 +/- 15.8%. Infective endocarditis occurred in 8 patients (44.5%) preoperatively. There were two hospital deaths (sudden death and multiorgan failure) and one death 3 years after operation (prosthetic endocarditis). Remaining 15 patients are in very good condition (NYHA I.-II.) 1-13 years after aortic valve replacement. CONCLUSIONS: Severely calcified aortic valve, endocarditis and associated incompetence are indications for valve replacement in patients with congenital aortic valve disease. Prevention of infective endocarditis is necessary pre and postoperatively, too. Long-term results after valve replacement for aortic valve stenosis are very good.

Adult↗
PubMed1997

[Results of open valvotomy in congenital stenosis of the aortic valve].

Between 1977 and 1992 at the Cardiosurgical Clinic of the Faculty Hospital in Hradec Králové on account of congenital valvular aortic stenosis 142 patients were subjected to catheterization. Valvotomy of a stenotic aortic valve was performed in 69 patients. The submitted paper evaluates the progression of aortic stenosis based on investigations of the aortic gradient and the area of the aortic orifice in repeatedly catheterized patients before and after valvotomy and evaluates also the results of surgery after a 1-15-year interval after surgery.

Adolescent↗
PubMed1996

S-100 protein positive (sustentacular) cells in pulmonary carcinoid tumorlets: a quantitative study of 24 cases.

Stellate-shaped S-100 protein positive sustentacular cells (SCs) appear to correlate inversely with the degree of tumor malignancy in some neuroendocrine tumors. Therefore, the SCs have been investigated in carcinoid pulmonary tumorlets and subsequently examined quantitatively in order to provide a basis for estimation of this phenomenon in tumorlet related lesions, especially carcinoids and neuroendocrine carcinomas. Pulmonary tissue from twenty-four patients with carcinoid tumorlets was studied immunohistochemically for S-100 protein positive SCs together with glial fibrillary acidic protein, actin, desmin, vimentin and cytokeratins. Tumorlet SCs were calculated per 10,000 tumorlet elements. The presence of SCs was proven in 18 subjects (75%) of all examined cases with quantitative frequency between 13 and 196 SCs per 10,000 tumorlet elements. The histogram showed three separate clusters of cases. Cluster 2 and cluster 3 with strikingly high frequency of SCs, i.e. from 66 up to 196 SCs per 10,000 tumorlet cells, may represent the biphasic differentiation potential of tumorlet elements. The mentioned lesions could be regarded as the possible precursors of pulmonary paragangliomas or paraganglioid carcinoids.

Aged↗
PubMed1996

[Results of pericardiectomy in the treatment of constrictive pericarditis].

Between 1981 and 1990 at the Cardiosurgical Clinic in Hradec Králové pericardectomy on account of chronic constrictive pericarditis was performed in 20 patients. The authors evaluated the duration of complaints, preoperative symptomatology, surgical procedure and results of the operation. Symptoms of right-sided cardiac congestion were recorded in 80% of the patients. Calcifications of the pericardium were found in 70% of the patients. During the postoperative period one patient died (5%). The long-term results evaluated at least three years after operation were very good in 65% of the operated patients. Treatment of chronic constrictive pericarditis is surgical and involves subtotal pericardectomy from medial sternotomy.

Adult↗
PubMed1996

[Satellite cells in pulmonary carcinoid tumorlets and carcinoids].

Pulmonary tissue of twenty-four patients with carcinoid tumorlets and twenty-three typical carcinoid tumors was studied immunohistochemically for stellate-shaped S-100 protein positive (sustentacular) cells. Sustentacular cells (SCs) have been calculated per 10,000 tumorlet or carcinoid elements. The presence of SCs was proved in 18 subjects (75%) of all examined tumorlet cases with quantitative frequency between 13 and 196 SCs per 10,000 tumorlet cells. These elements were also found in 18 carcinoid tumors (79%) of all 23 investigated cases with quantitative frequency between 5 and 927 SCs per 10,000 carcinoid cells. The cluster analysis showed two separate clusters in both groups of lesions with strikingly high frequency of SCs, i.e., from 66 up to 196 SCs/10,000 tumorlet elements and from 138 up to 923 CSs/10.000 carcinoid cells, respectively. SCs may not be used as an indicator of biological behaviour of pulmonary neuroendocrine tumors for their a broad frequency spectrum in examined benign lesions, i.e. tumorlets and typical carcinoid tumors.

Adolescent↗
PubMed1995

Serum levels of selected liver proteins following partial hepatectomy in the female rat.

Liver regeneration in the rat following partial hepatectomy (PH) is a frequently used model to study regulatory mechanisms in relation to cell growth and differentiation. In the present study, we analysed quantitative changes in the peripheral circulation of a number of important serum proteins following PH and laparotomy. Alpha-fetoprotein synthesis was induced in the PH rats and remained at very low levels in non-operated controls. Pregnancy-associated murine protein-1 levels and fibronectin levels were lower in the circulation of all operated animals compared with the intact controls. The serum levels of alpha-2 macroglobulin were elevated in all operated animals compared with the non-operated controls. Circulating complement factors C3c and C4 were present at significantly lower levels in PH animals than in rats following laparotomy. Small growth stimulating molecules (< 10 kDa) synthesized by different organs during the regenerative process have been described in the literature, but dialysates of the spleen and liver from non-operated rats and PH rats showed no significant impact on serum levels of the proteins in the present study.

Animals↗
PubMed1995

Unusual clinical presentation of endotracheal mesenchymoma.

This report describes an unusual case of 35 year old man with endotracheal mesenchymoma. He was treated for two years as asthmoid bronchitis or asthma without any favourable result. The diagnosis was established by x-ray tomography and the patient was referred to the surgical treatment. The tumour was removed and the trachea was reconstructed. Postoperative course was very good. The patient is doing well without recurrence many years following the operation.

Adult↗
PubMed1995

[Medical ethics in modern medicine].

The author submits basic information from the sphere of medical ethics as a modern medical discipline. After mentioning briefly its history, he reviews moral theories which can be applied in medical ethics and two basic patterns of moral reasoning in medicine. Finally he draws attention to some moral problems of contemporary psychiatry.

Ethics, Medical↗
PubMed1995

[Development of metabolic parameters in the early phases of liver regeneration].

Liver regeneration means the ability of the liver to restore the initial cellular mass after damage of various etiology. The primary mechanism of liver regeneration is not clearly defined yet. According to the recent knowledge the liver regeneration is directed by co-acting of many factors and events, among which the metabolic changes in regenerating liver tissue play important role. The aim of this study is to summarize the most important metabolic changes in the early steps of liver regeneration. The study presents the changes, which are taking place in the liver and in the other tissues and organs during liver regeneration, particularly after partial hepatectomy, but also in other types of liver damage. In the beginning the short overview of genetic changes, which enable the development of metabolic changes, is presented. After that the attention is drawn to the carbohydrate, lipid and protein metabolism. In the part, discussing the lipids, the results of experiments, in which the authors followed the influencing of liver regeneration in the rat after partial hepatectomy by means of parenteral and enteral application of various types of lipids and lipids combined with carnitine, is presented. In the next part the study discusses the metabolism of protein kinases and/or ions and trace elements. The energy metabolism as the necessary part of metabolic events is mentioned after that. In the last part the study draws attention to enzymatic retrodifferentiation in regenerating liver.

Animals↗
PubMed1995

[Carcinoid tumorlets and pulmonary hypoxia].

Relationship between carcinoid tumourlets and chronic pulmonary hypoxia was studied on a group of 29 patients coming to necropsy (25 cases) in the last 25 years or surgically treated (4 cases) for non-neoplastic pulmonary lesions. All tumourlets expressed the argyrophilia and were immunoreactive for neurone-specific enolase. Pulmonary hypoxia was studied according to the presence of chronic bronchitis, emphysema and microscopical signs of hypoxic arteriopathy. Cigarette smoking was an additional criterion. The results indicated a strong relationship between tumourlets and chronic pulmonary hypoxia. 79% of patients with tumourlets have had the emphysema and in 41% of examined cases with this lesion the chronic bronchitis was diagnosed. The hypoxic arteriopathy was present in 48% of subjects with emphysema and 27% of cases with bronchitis. It was found in the same number of patients with both the examined lung diseases. On the other hand, the possibility of other cause of neuroendocrine cell hyperplasia was to be considered in 17% of investigated subjects in whom no evidence for the above mentioned relationship was found.

Adult↗
PubMed1994

Hypercaloric lipid and glucose infusion reduces the mitochondrial respiratory activity in the regenerating rat liver.

In order to evaluate the liver mitochondrial response to an increased energy load, eight groups of rats were studied: a control group (no surgery), a sham-operated group, and 6 groups that had undergone partial hepatectomy (PH). The PH rats either had no infusion following surgery, saline, isocaloric lipid, hypercaloric lipid, isocaloric glucose or hypercaloric glucose infusion. After isolation of liver mitochondria 6, 12, 18 and 24 h after surgery states 3 and 4 of respiration were measured in vitro in the presence of succinate. State 3 and 4 mitochondrial respiration was higher in the sham-operated rats 6 h after surgery than in the control animals, and a gradual decrease towards control values occurred in the 12-24 h period following surgery. Results in mitochondria from PH rats showed variable results, in most cases both State 3 and 4 respiration was higher after PH, while the respiratory control index in general was lower. State 3 respiration was significantly increased in the PH isocaloric lipid and glucose infused groups 6, 12 and 18 h, but not 24 h after partial hepatectomy. The PH hypercaloric glucose and hypercaloric lipid infused rats showed decreases in the liver mitochondrial oxygen consumption after 6, 12 and 18 h of liver regeneration, this was more pronounced after hypercaloric lipid infusion. These results suggest that, in vitro, the surgery tends to increase Status 3 and Status 4 mitochondrial respiration. The hypercaloric parenteral nutrition, both lipid and glucose based, significantly decreased liver mitochondrial oxygen consumption in partially hepatectomized rats, particularly in the first hours of liver regeneration, with restoration 24 h after surgery.

Journal Article↗
PubMed1993

Surgical treatment of pulmonary artery primary myxosarcoma.

Case of the 47-year-old man, clinically suffering from recurrent dyspnoea, cough, syncopes, haemoptysis, unsuccessfully treated with anticoagulant and fibrinolytic agents, is described. Large masses of a tumour, occupying nearly the whole lumen of pulmonary artery and extending to peripheral branches, were removed during surgery. The tumour was histologically and immunohistochemically classified as myxosarcoma. Following surgery, the patient was asymptomatic, could do his original job (lorry-driver) for the next 14 months. He died 20 months after surgery, showing symptoms and signs of progressive right heart failure. At autopsy, the tumourous obliteration of the pulmonary artery and adjacent thrombosis were found. Primary pulmonary artery sarcoma should be considered in the differential diagnosis of recurrent pulmonary thromboembolism, especially when no peripheral vein thrombosis could be found.

Humans↗
PubMed1992

Liver regeneration in partially hepatectomized rats infused with carnitine and lipids.

Male Wistar rats were subjected to 65-70% hepatectomy. Immediately after surgery a 6-hour infusion was given containing 115 kJ/kg b.w. of long-chain fatty acids (Nutralipid Spofa) (N) or N combined with L-carnitine (Carnitene Sigma Tau) in doses 8 mg (12.4 mumol), 40 mg (62 mumol) and 200 mg (310 mumol)/kg b.w. The rats were killed 6, 18, 21, 24 and 30 h after surgery. The results of our study demonstrate that infusion of lipids combined with carnitine, has a stimulating dose-dependent effect on liver regeneration in partially hepatectomized rats, excluding the low dose of carnitine--8 mg/kg. The dose of carnitine of 40 mg/kg had the highest stimulating effect on the course of the liver DNA synthesis, culminating 21 h after partial hepatectomy. Later, 24 and 30 h after hepatectomy, the mitotic activity of hepatocytes was highest in rats infused with carnitine in doses of 200 mg/kg b.w.

Animals↗
PubMed1992

Effect of propylthiouracil on liver regeneration in rats after partial hepatectomy.

The effect of propylthiouracil (PTU) on the growth activity of intact liver and liver regenerating after partial (65-70%) hepatectomy (PH) was studied in rats. PTU (Propycil, Kali-Chemie, FRG) was dissolved in drinking water (1 g PTU per litre) and this was given to the rats, as their sole source of fluids, three days before PH and then up to the end of the experiment. In rats given PTU, marked inhibition of liver DNA synthesis and the mitotic activity of hepatocytes was found after PH. This effect was potentiated to some extent by partial inanition of the experimental animals given PTU, as demonstrated in a paired feeding test in control rats. PTU inhibition of DNA synthesis in intact and regenerating liver also took effect in thyroidectomized rats, even with substitution (thyroid hormone) therapy. The experiments demonstrated that the effect of propylthiouracil on DNA synthesis in the liver is mediated primarily by way of its direct effect on the liver.

Animals↗
PubMed1992

[The effect of carnitine on the early phase of liver regeneration after partial hepatectomy in rats with experimental diabetes].

The effect of intraperitoneally administered carnitine (10 or 100 mg/kg) on the early stage of liver regeneration after two-third hepatectomy was studied in rats with experimentally induced alloxan diabetes (60 mg/kg IV). The level of regeneration was assessed mainly on the basis of DNA synthesis in the liver. Untreated diabetic rats exhibited significantly lower values of DNA synthesis determined 24 hours after hepatectomy. Administration of carnitine resulted in a significant increase in DNA synthesis over the given time interval. The stimulatory effect of carnitine in diabetic rats was confirmed also by the recorded values of serum lipids, particularly by the decreased concentration of triacylglycerols and the increased concentration of HDL-cholesterol, as determined in carnitine treated diabetic rats 24 hours following partial hepatectomy. (Tab. 2, Fig. 3, Ref. 34.)

Animals↗
PubMed1991

Effect of glucose and branched chain amino acid (BCAA) infusion on onset of liver regeneration and plasma amino acid pattern in partially hepatectomized rats.

Immediately after 70% hepatectomy, rats were infused via the jugular vein with one of the following solutions: saline, 3% or 8% glucose solution, 3% BCAA solution, 8% Nutramin (17% BCAA) or 8% Nutramin enriched with BCAA (47% BCAA). Rats were killed 18, 21, 24 and 30 h after partial hepatectomy. The course of liver regeneration was assessed from incorporation of labeled thymidine into DNA and from hepatocyte mitotic activity. After partial hepatectomy a decrease of glycemia and increase of plasma phenylalanine concentrations were observed. Glucose infusion had a pronounced inhibiting effect on the onset of liver regeneration. The decreased incorporation of labeled thymidine into DNA and the decreased hepatocyte mitotic activity in glucose-infused rats were associated with higher plasma concentrations of tyrosine and phenylalanine. Parenteral administration of 3% BCAA solution and 8% Nutramin enriched with BCAA had a favourable effect on the onset of liver regeneration after partial hepatectomy compared with glucose- and Nutramin-infused groups. In BCAA-infused rats elevated levels of BCAA and decreased concentrations of tyrosine and phenylalanine were noted.

Amino Acids↗