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Dive into the research topics where Jan Dvořáček is active.

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Featured researches published by Jan Dvořáček.


European Urology | 2003

Division of Lymphatic Vessels at Varicocelectomy Leads to Testicular Oedema and Decline in Testicular Function According to the LH-RH Analogue Stimulation Test

Radim Kočvara; Jiřı́ Doležal; Richard Hampl; Ctibor Povýšil; Jan Dvořáček; Martin Hill; Zdeněk Dítě; Zdeněk Staněk; K. Novak

OBJECTIVES To study the andrological outcome of the division of testicular lymphatic vessels at varicocelectomy in children and adolescents. METHODS Testicular size and basal and stimulated luteinizing hormone (LH) and follicle-stimulating hormone (FSH) values were determined prospectively in 86 patients with left unilateral varicocele grades II-III. 22 patients underwent lymphatic non-sparing surgery (LNS group), 10 of them with artery sparing (LNS/AS) and 12 without artery sparing (LNS/ANS), 23 patients underwent lymphatic sparing repair (LS group) and 41 patients were treated conservatively (NT group). RESULTS The LNS group demonstrated significantly greater left testicular enlargement at six weeks and one year following repair, left testicular hypertrophy developed in 31.8% and hydrocele in 22.7% of patients. Marked oedema of intertubular tissue and a varying degree of tubular injury was observed in boys surgically treated for hydrocele. In the LS group, neither hypertrophy nor hydrocele developed postoperatively, the LH stimulated values were lower than in LNS/ANS group (p<0.05) and the NT group (p<0.04), the FSH stimulated values were lower than in the LNS/ANS group (p<0.001). CONCLUSIONS Division of lymphatic vessels at varicocelectomy is associated with an excessive increase in testicular volume due to oedema, and with a reduced testicular function according to higher LH and FSH stimulated values. Preservation of lymphatics is strongly advised in varicocelectomy in adolescents to ensure better andrological outcome.


European Urology | 2002

Qualitative and Quantitative Detection of Urinary Human Complement Factor H-Related Protein (BTA stat and BTA TRAK) and Fragments of Cytokeratins 8, 18 (UBC Rapid and UBC IRMA) as Markers for Transitional Cell Carcinoma of the Bladder

M. Babjuk; M Koštı́řová; K Mudra; S.M. Pecher; H Smolová; L Pecen; Z Ibrahim; Jan Dvořáček; L. Jarolim; J Novák; T Zima

OBJECTIVE To evaluate the role of BTA stat, BTA TRAK, UBC Rapid, UBC IRMA and voided urinary cytology in the detection of bladder transitional cell carcinoma (TCC). METHODS The study included 78 patients with TCC of the bladder (group A), 62 patients with a history of bladder TCC without tumor recurrence at the time of examination (B, control group), 20 patients with other malignancy of the urinary tract (C), 38 patients with non-malignant urinary tract diseases (D), 10 patients with urinary tract infection (E) and 10 healthy volunteers (F). Except in group F, voided urine was collected before cystoscopy or cystectomy. RESULTS The specificity and sensitivity in bladder cancer detection were 87.1 and 74.4%, respectively with BTA stat, 79.3 and 48.7%, respectively with UBC Rapid, 100 and 33.3%, respectively with cytology, 72.6 and 75.6%, respectively with BTA TRAK, 64.5 and 70.5%, respectively with UBC IRMA. CONCLUSIONS The BTA stat and BTATRAK tests are superior to UBC Rapid, UBC IRMA and urinary cytology in detection of bladder TCC. In daily practice however cytology remains the best adjunct to cystoscopy because of its high sensitivity in Tis and 100% specificity. Cystoscopy cannot be replaced by any of evaluated methods.


Urology | 2008

Urinary Cytology and Quantitative BTA and UBC Tests in Surveillance of Patients with pTapT1 Bladder Urothelial Carcinoma

M. Babjuk; Viktor Soukup; Michael Pešl; M. Koštířová; E. Drncová; H. Smolová; M. Szakácsová; Robert H. Getzenberg; I. Pavlík; Jan Dvořáček

OBJECTIVES To compare results of urinary cytology, quantitative detection of human complement factor H-related protein (BTA TRAK), and urinary fragments of cytokeratins 8 and 18 (UBC IRMA) with the recurrence status in patients with pTapT1 bladder cancer and to define the possible role of these methods in a surveillance protocol. METHODS We collected urine from 88 consecutive patients with primary pTapT1 tumors before the first transurethral resection (TURB) and before each follow-up cystoscopy. In all samples urinary cytology and quantitative BTA and UBC tests were performed. We compared results with recurrence status and with tumor characteristics in the case of recurrence. We constructed receiver operator characteristic (ROC) curves for quantitative methods. In addition, we evaluated individual cutoffs based on pretreatment levels. RESULTS During the mean follow-up of 16.96 months, we performed 313 cystoscopies, 93 of which were positive in 51 patients. The sensitivity and specificity of cytology, BTA, and UBC were 19.8% and 99%, 53.8% and 83.9%, and 12.1% and 97.2%, respectively. The sensitivity of pTis detection was 66.6%, 0%, and 100%, respectively. With cutoffs set to a sensitivity of 90%, the specificity of BTA and UBC dropped to 24.8% and 20.4%, respectively. Individually calculated cutoffs did not provide a significant benefit. CONCLUSIONS Because of high specificity and sensitivity in pTis detection, urinary cytology fulfills requirements for an adjunctive method to cystoscopy. Quantitative BTA and UBC tests have a low sensitivity in the detection of bladder cancer recurrence and cannot be used routinely to reduce the number of cystoscopies during follow-up.


Pathology Research and Practice | 2003

Large cell neuroendocrine carcinoma of the urinary bladder with lymphoepithelioma-like features.

Pavel Dundr; Michael Pešl; Ctibor Povýšil; Ivana Vitkova; Jan Dvořáček

The group of undifferentiated carcinomas of the urinary bladder encompasses small cell undifferentiated carcinoma, giant cell carcinoma, lymphoepithelioma-like carcinoma (LELC), and large cell neuroendocrine carcinoma (LCNEC). These tumors are either pure or can be associated with other components, such as transitional cell carcinoma, squamous cell carcinoma, and adenocarcinoma. We report a case of LCNEC of the urinary bladder in a 54-year-old woman. Histologically, the tumor showed features of LELC; immunohistochemically, the tumor cells reacted to chromogranin A, NSE, and synaptophysin. In addition to these neuroendocrine markers, tumor cells were positive for cytokeratin CAM 5.2 and AE1/AE3, and there was focal positivity for vimentin. In situ hybridization for the detection of Epstein-Barr virus was negative. Despite radical cystourethrectomy and six courses of chemotherapy, the patient developed metastases invading the left inguinal lymph nodes 11 months postoperatively. Currently, 16 months postoperatively, the patient has developed metastases spreading into the lymph nodes of the right ischiorectal fossa; therefore, she is receiving a new cyclus of chemotherapy. There are only three previously reported cases of LCNEC of the urinary bladder, and the significance of neuroendocrine differentiation in non-small cell carcinomas at this location remains to be established. However, LELC appears to be a separate clinicopathological entity with sensitivity to chemotherapy and a relatively favorable prognosis. The differentiation between LELC and LCNEC with prominent inflammatory reaction could be of therapeutic relevance. However, in our case, this was possible using immunohistochemistry only.


Pathology Research and Practice | 2003

Pigmented composite paraganglioma-ganglioneuroma of the urinary bladder

Pavel Dundr; Daniela Dudorkinová; Ctibor Povýšil; Michael Pešl; Marko Babjuk; Jan Dvořáček

We report a case of a pigmented composite paraganglioma-ganglioneuroma of the urinary bladder in a 70-year-old female. Grossly, the tumor measured 6.5 cm in diameter and had arisen from the base of the urinary bladder. Histologically, the tumor was composed of approximately equal components of paraganglioma and ganglioneuroma, which were partly separated and partly mixed, and intermingled with each other. There were foci of ample dark brown pigmentation in the cytoplasm of chromaffin paraganglioma cells. The pigment was Masson-Fontana-positive and had been bleached by hydrogen peroxide (H2O2). Electron microscopy showed large, abundant, pleomorphic electron-dense granules consistent with neuromelanin. In addition, there were numerous electron-dense neurosecretory-type granules. Neuromelanin, melanin or lipofuscin are occasionally observed in paragangliomas, although the occurrence of these pigments has never been described in a composite tumor originating from either adrenal medulla or extraadrenal paraganglia. To the best of our knowledge, our report represents the first case of pigmented composite paraganglioma-ganglioneuroma and expands the morphological spectrum of these unusual tumors.


Journal of Pediatric Urology | 2010

Transmesocolic laparoscopic pyeloplasty in children: A standard approach for the left-side repair

Josef Sedláček; Radim Kočvara; Jaroslav Molčan; Zdeněk Dítě; Jan Dvořáček

OBJECTIVE To compare the transmesocolic approach in the left laparoscopic pyeloplasty with the laterocolic right-side repair in children. PATIENTS AND METHODS Dismembered pyeloplasty was performed in 77 consecutive children aged 1.2-18.2 years. The transmesocolic approach was used in 49 patients with left hydronephrosis (group I) and the conventional laterocolic approach in 28 patients with right hydronephrosis (group II). Three age groups were defined. RESULTS The transmesocolic approach was applicable in 48 of 49 patients (98%); the colic vessels were preserved. The operation time was significantly shorter in the transmesocolic group, also when comparing patients with similar age, incidence of crossing vessels and urinary diversion. A shorter operation time was achieved in children without internal urine diversion. Postoperative complications were encountered in 6.3% of group I and 7.1% of group II without any conversion to open repair or recurrence of obstruction within a 2.5-year follow-up period. CONCLUSIONS The transmesocolic approach offers clear anatomy and provides safe access to the dilated left renal pelvis and crossing vessels. The operative time is shorter due to very limited tissue dissection. The medial reflection of the colon is avoided. This approach allows for microsurgical performance of the left-side pyeloplasty in all paediatric age groups.


Pathology Research and Practice | 2007

Anaplastic variant of spermatocytic seminoma

Pavel Dundr; Michael Pešl; Ctibor Povýšil; Petra Prokopová; Ivan Pavlík; Viktor Soukup; Jan Dvořáček


Pathology Research and Practice | 2007

Pigmented microcystic chromophobe renal cell carcinoma

Pavel Dundr; Michael Pešl; Ctibor Povýšil; Daniel Tvrdík; Ivan Pavlík; Viktor Soukup; Jan Dvořáček


Česká urologie | 2008

Predikce patologické klasifikace karcinomu prostaty

O. Čapoun; M. Babjuk; Jan Dvořáček; Hanuš Tomáš; Libor Šafařík; Ivan Pavlík


Česká urologie | 2008

Postgraduální vzdělávání v urologii - současný stav

Radim Kočvara; Jan Dvořáček

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Michael Pešl

Charles University in Prague

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Ctibor Povýšil

Charles University in Prague

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Radim Kočvara

Charles University in Prague

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Viktor Soukup

Charles University in Prague

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Ivan Pavlík

Charles University in Prague

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Zdeněk Dítě

Charles University in Prague

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Marko Babjuk

Charles University in Prague

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Josef Sedláček

Charles University in Prague

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K. Novak

Charles University in Prague

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M. Babjuk

Charles University in Prague

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