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Biomedical subjects

J Marek

Publications and source records attributed to J Marek.

At least 19 recordsLinked to original sources
PubMed2000

Stereospecific formation of alpha-hydroxycarboxylato oxo peroxo complexes of vanadium(V). Crystal structure of (NBu4)2[V2O2(O2)2(L-lact)2] x 2H2O and (NBu4)2[V2O2(O2)2(D-lact)(L-lact)] x 2H2O.

An overview of structurally characterized alpha-hydroxycarboxylatodioxo- and alpha-hydroxycarboxylatooxoperoxovanadates(V) is presented and the geometric parameters of the V2O2 bridging core are discussed. The first case of a stereospecific formation of oxoperoxovanadates(V) is reported: The crystal structures of the isomeric compounds (NBu4)2[V2O2(O2)2(L-lact)2] x 2H2O and (NBu4)2[V2O2(O2)2(D-lact)(L-lact)] x 2H2O (lact = C3H4O3(2-), the anion of the lactic acid) differ mainly in the arrangement of the V2O2 core and in mutual orientation of the V=O bonds. The complexes with achiral ligands adopt the same structural type as the complexes formed from a racemic mixture of a chiral ligand, while the structure obtained using an enantiopure L,L-hydroxycarboxylate is different.

Crystallography, X-Ray↗
PubMed2000

Increase of adhesion molecules, fibrinogen, type-1 plasminogen activator inhibitor and orosomucoid in growth hormone (GH) deficient adults and their modulation by recombinant human GH replacement.

OBJECTIVE: GH deficiency (GHD) is usually associated with a higher incidence of cardiovascular disease (CVD). The aim of this study was to establish whether patients with GHD, like those with CVD, show an increase in fibrinogen (FBG), type-1 plasminogen activator inhibitor (PAI-1), acute phase response proteins (APR), and soluble adhesion molecules. The effect of recombinant human GH (rhGH) replacement, on these parameters was also investigated. PATIENTS AND DESIGN: Concentrations of PAI-1 antigen (Ag), adhesion molecules sE-selectin, sP-selectin, and intercellular adhesion molecule-1 (sICAM-1), FBG and levels of APR orosomucoid (ORM), and 'negative APR' transferrin (TRF) were established in 11 panhypopituitary (PHP) patients (eight men and three women, age median 39.0 years, body mass index (BMI) 27. 49 +/- 3.89 kg/m2) before and after 12-month replacement with rhGH. Control values were obtained by examination of 33 healthy age and sex matched subjects (24 men and nine women with BMI 24.16 +/- 1.99 kg/m2). RESULTS: PHP patients had higher concentrations of ORM (0.80 +/- 0.25, vs. 0.61 +/- 0.20 g/l; P = 0.05), FBG (3.22 +/- 0.48, vs. 2.57 +/- 0.47 g/l; P = 0.001), PAI-1 Ag (97.12 +/- 33.23, vs. 44.11 +/- 21.40 microgram/l; P = 0.001), sE-selectin (72.42 +/- 28.35, vs. 42. 80 +/- 12.60 microgram/l; P = 0.004), sP-selectin (221.26 +/- 75.12, vs. 104.79 +/- 26.01 microgram/l; P = 0.001) sICAM-1 (409.75 +/- 137.78, vs. 228.10 +/- 37.54 microgram/l; P = 0.001), and lower levels of TRF (2.14 +/- 0.40, vs. 2.76 +/- 0.39 g/l; P = 0.001) than controls. After 12-month rhGH replacement the patients showed an increase of TRF (2.64 +/- 0.84 g/l, P = 0.037) and decrease of soluble adhesion molecules (sE-selectin 57.98 +/- 27.04 microgram/l, P = 0.01, sP-selectin 121.74 +/- 50.42 microgram/l, P = 0.007; and sICAM-1 279.95 +/- 88.32 microgram/l, P = 0.005), which then, similarly to the ORM (0. 67 +/- 0.12 g/l) and FBG level (2.82 +/- 0.51 g/l), did not statistically differ from the values in the control group. CONCLUSION: rhGH replacement led to modulation of the 'inflammatory response' in panhypopituitary patients. This modulation occurred locally at vascular endothelium level where after rhGH replacement, sE-selectin, sP-selectin and sICAM-1 concentrations decreased, a similar effect as in the systemic inflammatory response, as was also apparent from the changes in acute phase response protein levels.

Adult↗
PubMed2000

Late complications and quality of life after atrial correction of transposition of the great arteries in 12 to 18 year follow-up.

BACKGROUND: Most adolescents and young adults born with transposition of the great arteries and survivors of Mustard operation are alive today and are leading ordinary lives. How far is the quality of their life influenced by residual findings? METHODS: We have analysed the oldest group of 177 children operated on with the Mustard procedure during 1979-1984 from our total experience of 609 corrections of transposition of the great arteries until 1996. In the long-term follow-up 12 to 18 years after Mustard operation the clinical investigation, 24 hours ECG Holter monitoring, 2D and colour flow Doppler echocardiography, radionuclide angiocardiography and exercise testing were performed. RESULTS: Basic sinus rhythm had 61% of 137 survivors, sinus node dysfunction had 51%. All but 4 patients needed no antiarrhythmic therapy. There were 10 sudden deaths. Severe tricuspid valve regurgitation developed in 15.9% of children, and decreased to 6% after intensive medical treatment. The right ventricular systolic dysfunction was found on radionuclide ventriculography in 8% of children after surgery. The left ventricular ejection fraction was subnormal in 10% and left ventricular diastolic function expressed by rapid filling fraction was subnormal in 80% of patients and may cause inability to increase cardiac output at exercise The obstruction of caval veins was found in 9%. There were neurological complications in 13.3% (10% already preoperatively) but severe brain damage was found in 4.4% only. CONCLUSIONS: Exercise tolerance with the maximum oxygen consumption over 30 ml/kg/min in 96% of investigated children suggests the good ability and full efficiency for recreation sports. Most survivors (84%) are reported to lead ordinary lives and function in NYHA class I.

Adolescent↗
PubMed1999

Regression of acromegalic left ventricular hypertrophy after lanreotide (a slow-release somatostatin analog).

A group of 13 acromegalic patients was treated with lanreotide for 18 months and followed-up echocardiographically; these patients showed significant correlations between the decrease of both growth hormone (GH) and insulin-like growth factor-1 and the decrease of left ventricular mass index. This documents a regression of left ventricular hypertrophy in acromegaly after lanreotide treatment, the degree of which is dependent on the magnitude of the decrease of GH and insulin-like growth factor-1 serum levels.

Acromegaly↗
PubMed1999

Retinal oligodendroglioma.

PURPOSE: To report a case of oligodendroglioma originating from the accessory glia of retina. METHOD: Case report of a 72-year-old woman with a tumor in the temporal fundus of the right eye that was suspected to be choroidal melanoma. Enucleation was declined, but 5 years later, because of tumor growth, pain, and loss of light perception, the globe was enucleated. RESULTS: Histopathologic examination disclosed a neuroepithelial tumor with a structure of oligodendroglioma. Melanoma and metastatic tumor were excluded. CONCLUSIONS: Oligodendrogliomas are rare in the retina but may originate from retinal oligodendrocytes. This case suggests that the differential diagnosis of choroidal melanoma should include the possibility of oligodendroglioma.

Aged↗
PubMed1999

Crystallization and preliminary X-ray diffraction analysis of haloalkane dehalogenase LinB from Sphingomonas paucimobilis UT26.

Haloalkane hydrolytic dehalogenase LinB from Sphingomonas paucimobilis UT26, an enzyme which releases chloride or bromide anion from n-halogenated alkanes and has a broad range of substrate specificity, was crystallized using the hanging-drop vapour-diffusion method at 278 K. The best crystals were obtained by microseeding with a precipitant containing 18-20%(w/v) PEG 6000, 0.2 M calcium acetate and 0.1 M Tris-HCl pH 8.9. The crystals diffract to at least 1.60 A using synchrotron X-ray under cryogenic (100 K) conditions. They belong to the orthorhombic space group P21212 with unit-cell parameters a = 50.29, b = 71.70, c = 72.73 A. The asymmetric unit contains one molecule of the enzyme.

Crystallization↗
PubMed1999

[Sleep apnea syndrome in acromegaly. Treatment and development-- retrospective analysis].

In total 56 subjects with acromegaly (37 men and 19 females) were examined in attempt to find sleep apnoea syndrome (SAS). The examination consisted of clinical examination and of all-night monitoring MESAM4 or polyMESAM. The diagnosis of SAS was established in 76.4% of subjects: 31 men and 11 females, average age 51.8 (SD +/- 9.6) years. The average ODI (oxygen desaturation index--number of oxygen saturation drops per 1 hour of sleep) of SAS patients was 29.2 (+/- 20.7). The therapy of SAS was recommended to 27 patients: sleeping position on the side (3 patients), reduction of the weight (8 patients), change of hypnotic drug (1 patient) and CPAP--continuous positive airway pressure (24 patients). CPAP titration was performed in 18 patients (in one subject the titration was repeated 4 years later). CPAP was titrated within all-night polysomnography in 10 subjects and in 9 subjects using self adjusting CPAP. Primary acceptance of CPAP was 94.4%. The average CPAP pressure was 7.8 (+/- 2.1) mbar. The theoretical duration of CPAP use was 546.6 (+/- 533.7) days. Long term compliance was considered as sufficient (weekly 25 hours or more) in 66.7% of patients. Ten patients underwent important acromegaly therapy or its change during the follow up and the improvement or the disappearance of SAS symptoms occurred in 6 of them.

Acromegaly↗
PubMed1998

[Can normalization of vascular cytoadhesive activity be explained by the anti-atherosclerosis effect of growth hormone?].

BACKGROUND: The increased mortality caused by premature atherosclerosis has been shown among patients with hypopituitarism receiving conventional hormone treatment but with unsubstituted growth hormone deficiency. This experience belongs among the most important arguments in favour of replacement with growth hormone. The mechanisms of the antiatherogenic effect of growth hormone are poorly understood. The protective effect of growth hormone on the vascular endothel and its intervention in the clotting process, which have not been yet elucidated, may be the causative factors. METHODS AND RESULTS: The endothelial damage as given by measuring of circulating soluble cytoadhesive molecules sE-selectin, sP-selectin and intercellular adhesive molecule 1 (ICAM 1) was measured in 15 adult panhypopituitaric patients before and after 1 year treatment with recombinant human growth hormone. The blood levels of all of these cytoadhesive molecules decreased significantly (p < 0.01) during the treatment. None of the concomitantly followed coagulation tests (prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin III, von Willebrand's factor and D-dimer) was significantly changed during the treatment. The tendency to decrease (p = 0.054) was observed with antithrombin III. CONCLUSIONS: The decrease of circulating cytoadhesive molecules in blood during the treatment of growth hormone gives evidence for its protective effect, either direct or mediated, on the vascular endothel. These findings could bring an explantation for the premature atherosclerotic changes in hypopituitarism and antiatherogenic effect of growth hormone.

Adult↗
PubMed1998

[Treatment of hypopituitarism in adults with growth hormone improves improves the thickness of the arterial intima].

BACKGROUND: Increased mortality of hypopituitary adults with atherosclerotic vascular disease is commonly explained by growth hormone deficiency and forms the main argument for the growth hormone replacement. At the same time it is known that the growth hormone-IGF-I axis stimulates the vessel wall proliferation as an initial step of atherosclerosis. Investigation of the arterial intima thickness in hypopituitary adults with duplex ultrasound system and its follow up during the growth hormone therapy may clarify these effects of growth hormone on the vessel wall. METHODS AND RESULTS: Luminal diameter, maximal blood flow velocity and arterial intima thickness of common carotid arteries was measured with colour duplex ultrasound system in 15 adults with hypopituitarism before and after one year therapy with recombinant growth hormone. The results were compared with healthy controls matched for gender, age, blood pressure and weight. The luminal diameter did not changed during the therapy with growth hormone and was the same in patients and controls. Maximal blood velocity in hypopituitary patients before the therapy was lower than in control subjects (74.8 +/- 13.9 cm/s vs. 94.0 +/- 21.0 cm/s), but the statistical difference was only borderline. Arterial intima thickness was significantly thinner in hypopituitary patients when compared with controls (0.56 +/- 0.1 mm vs. 0.71 +/- 0.12 mm, p < 0.001) but became thicker after the treatment and was not any more different from the controls (0.56 +/- 0.1 mm vs. 0.66 +/- 0.1 mm, p < 0.001). CONCLUSIONS: In hypopituitary adults the arterial intima thickness of common carotid arteries is less than in healthy controls. The reduced thickness was normalised after one year treatment with growth hormone. Atheromatous plaques were not found either before or after the treatment. Duplex ultrasound measurement may be one of the means of checking of the effects of growth hormone therapy.

Adult↗
PubMed1998

Dexfenfluramine in psychotic patients.

Dexfenfluramine (DF) is contraindicated in severe psychiatric disorders and in depression. We used DF in 3 patients with chronic psychosis and severe overeating without changes in psychiatric pharmacotherapy. Two patients had paranoid schizophrenic psychosis with hallucinations, one patient mixed psychosis, beginning with lactation psychosis, and several attacks of hallucinations and depression later. Overeating was removed in all 3 patients without any negative effect on the psychotic state. All patients were able to maintain their body weight. Two patients with poorly controlled diabetes improved markedly their metabolic status. Doses up to 75 mg per day of DF were necessary during binge eating episodes in one patient. We conclude that DF can be used with care under close psychiatric supervision in psychotic patients with severe overeating.

Adult↗
PubMed1998

Primary manifestation of Hodgkin's disease in the central nervous system.

A 62-year-old woman presented with loss of memory and a mild hemiparesis. Neuroradiology demonstrated a left frontoparietal tumour. Biopsy specimens of this lesion revealed intracerebral Hodgkin's lymphoma, a diagnosis supported by immunohistochemical reactions of the tumour cells for the CD30 antigen. Additional cell cycle studies revealed a high proliferative activity of the tumour cells in association with absence of apoptosis. There was no evidence that overexpression of bcl-2 or Epstein-Barr virus infection was involved in the pathogenesis of this neoplasm. Lymphomas in the lung were detected 3 months later. Following neurosurgical excision, radiotherapy, and chemotherapy, the patient had no evidence of Hodgkin's disease after 13 months of follow-up.

Apoptosis↗
PubMed1998

Evaluating institutional variability of duplex scanning in the detection of carotid artery stenosis.

PURPOSE: Duplex scanning is widely used to measure carotid artery stenosis, but the issue of variability between institutions must be raised. To examine for this potential variability, we evaluated two ATL Ultramark 9 duplex machines at two hospitals within our institution. METHODS: Stenosis was calculated angiographically as in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Internal carotid artery (ICA) to common carotid artery (CCA) peak systolic velocity (PSV) ratios were determined using the two ATL machines. Receiver operating characteristic (ROC) curves were generated for each hospital. RESULTS: ROC curves varied significantly. The area under the curve from hospital 1 was 0.95 (SE = 0.021); the area under the curve from hospital 2 was 0.87 (SE = 0.034). The curves were essentially statistically different (P = 0.0516). COMMENTS: We showed a difference in predicting diameter stenosis utilizing ICA PSV/CCA PSV ratios at two hospitals within our institution. Variability is likely due to technologists, since equipment and physician interpreters were the same. Criteria must be developed for each different machine in each laboratory. Quality assurance is critical to minimize variability.

Carotid Stenosis↗
PubMed1998

Primary repair of transposition of the great arteries with interrupted aortic arch.

Primary repair of transposition of the great arteries with interrupted aortic arch was performed in a 2 day old neonate weighing 2.1 kg. The repair consisted of a direct anastomosis between the ascending and the descending aorta and an arterial switch repair without Lecompte procedure because of the side by side position of the great arteries and an anomaly of the coronary arteries. A total of 28 months after the repair, the patient remains in excellent clinical condition.

Aorta, Thoracic↗
PubMed1998

Results of primary and two-stage repair of interrupted aortic arch.

OBJECTIVE: Early results of primary and two-stage repair of interrupted aortic arch have improved. Experience with different surgical approaches should be analysed and compared. METHODS: Forty neonates and infants with interrupted aortic arch underwent primary repair (19 patients) or palliative operation (21 patients). Twenty (50%) patients were followed-up for 5.1+/-4.3 years. All patients were regularly examined with the aim of determining clinical development, presence of residual lesions or complications and need for re-intervention. Aortic arch and the left ventricular outflow tract growth were assessed by echocardiographic examination. Data from hospital and outpatient department records were analysed. RESULTS: The early mortality was 61.9% after palliative operations and 36.8% after the primary repair. Presence of complications (P < 0.001), earlier year of surgery (P < 0.01), bad clinical condition and acidosis (P < 0.05) represented statistically significant risk factors for death in the whole series. In seven (87.5%) out of eight early survivors, after the initial palliative operation, closure of ventricular septal defect and debanding were done, and in three (37.5%) patients, re-operation for aortic arch obstruction was also required. Out of 12 patients, after the primary repair, one required early re-operation for persistent left ventricular outflow tract obstruction and two needed late re-intervention for left bronchus obstruction. In three (25%) patients, after the primary repair, left ventricular outflow tract obstruction with a maximal systolic pressure gradient higher than 30 mmHg developed. At present, all 20 early survivors are alive. Five patients, after palliative operation, are in NYHA class 1, but in three patients, who are in class III or IV, the outcome is influenced by severe complications. All patients after the primary repair are in class I or II. CONCLUSIONS: Our experience confirmed better results after the primary repair of interrupted aortic arch, which was associated with lower mortality, prevalence of severe complications and need for re-intervention. Higher prevalence of subaortic stenosis after primary repair could be explained by patient selection early in our experience. We recommend the primary repair of interrupted aortic arch and associated heart lesions in neonates, however, in unfavourable conditions an individualised surgical approach with initial palliative surgery should be considered.

Anastomosis, Surgical↗
PubMed1998

Repair of tetralogy of Fallot associated with atrioventricular septal defect.

Tetralogy of Fallot, when associated with atrioventricular septal defect permitting shunting at ventricular level, represents a complex cyanotic congenital malformation. Experience with surgical repair is limited, and results vary considerably. Between 1984 and 1996, we repaired 14 consecutive patients with this combination seen in our center. Their ages ranged from 8 months to 21 years (median 7.4 years). Six (42.9%) had Down's syndrome. In eight patients the correct diagnosis was made using echocardiography alone. In the remaining six patients, who had previously-constructed arterial shunts and/or suspected pulmonary arterial stenosis, catheterization and angiocardiography were also performed. The repair consisted of double patch closure of the septal defect, reconstruction of two atrioventricular orifices, and relief of pulmonary stenosis at all levels. In five patients with a hypoplastic pulmonary trunk, a monocusp transannular patch (four patients) or an allograft (one patient) was used for restoration of continuity from the right ventricle to the pulmonary arteries. Patch enlargement of one or both pulmonary arteries was necessary in five patients. One patient (7.1%) died early, and another late. The twelve surviving (85.8%) patients have been followed for 1.2-12.5 years after surgery (median 4.9 years, mean 5.9+/-3.9 years). During the follow-up, reoperation was necessary for repair of residual ventricular septal defect and pulmonary regurgitation in two patients, and closure of an atrial septal defect and alteration to left atrioventricular valvar regurgitation in one patient. Seven patients are in class I of the New York Heart Association, four in class II, and one in class III. Tetralogy of Fallot associated with atrioventricular septal defect can be corrected with low mortality and good long-term results. Residual lesions, however, have a tendency to progress, especially when seen in combination. After surgery, all patients need long-term close follow-up.

Adolescent↗
PubMed1998

[Congenital thrombosis of the aortic arch simulating aortic coarctation in a neonate].

The authors present the case-history of a two-day-old neonate with clinical signs of critical coarctation of the aorta where echocardiography revealed thrombosis of the aortic arch and isthmus. By surgery it was impossible to remove the organized thrombus from the aorta, therefore the portion of the aorta with the thrombus was resected and the aorta was reconstructed by an end-to-end anastomosis. After surgery long-term anticoagulation treatment with Warfarin was started. Examination of haemocoagulation factors, incl. proteins C and S and antithrombin III revealed normal findings. The test for lupus erythematosus was also negative. From the case-history of the mother's pregnancy the cause of the serious congenital aortic thrombosis could not be traced. The child is all right after surgery and thrives.

Aorta, Thoracic↗
PubMed1998

[Primary repair of interrupted aortic arch in neonates].

In the Kardiocentrum, University Hospital Motol, Prague, protocol of the primary repair of interrupted aortic arch was introduced, and between 1993-1997, 15 neonates aged 1-26 days (median 5 days) were operated on. Treatment with prostaglandins E for maintenance of the ductal patency, correction of metabolic acidosis, and treatment of all complications were necessary before surgery. The correction was performed from the midline sternotomy approach, in extracorporeal circulation and deep hypothermia with circulatory arrest. Direct anastomosis between the ascending and the descending aorta was possible in all the patients. At the same time, associated heart lesions were corrected (ventricular septal defect in 13, persistent truncus arteriosus in 3, subaortic stenosis in 2, transposition of the great arteries, double-outlet right ventricle and aortico-pulmonary window in 1 patient, each). Four (26.7%) patients died after surgery. Out of the first 6 neonates 3 (50.0%) died, but out of the subsequent 9 patients only 1 (11.1%) died. Reoperation was necessary in 2 patients. All 11 early survivors are alive and doing well 8-54 months after the repair. In one of them restenosis at the site of aortic anastomosis and hemodynamically significant subaortic stenosis occurred. All the remaining patients have a nonrestrictive aortic anastomosis. Primary repair of interrupted aortic arch and associated heart lesions can be performed in a neonate with reasonable mortality. Treatment of complications is necessary before surgery. Results depend especially on the patient's clinical condition and experience of the center.

Aorta, Thoracic↗