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Dive into the research topics where Waldemar S. Costa is active.

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Featured researches published by Waldemar S. Costa.


BJUI | 2007

A morphometric analysis of bulbar urethral strictures.

Andre G. Cavalcanti; Waldemar S. Costa; Laurence S. Baskin; Jack A. McAninch; Francisco J.B. Sampaio

In a beautifully descriptive paper, authors from Rio de Janeiro and San Francisco report a quantitative and qualitative histological analysis of spongiosal tissue in patients with bulbar urethral strictures. They found that stricture formation was characterised by major alterations in extracellular matrix features.


The Journal of Urology | 2002

Testicular Migration: Remodeling of Connective Tissue and Muscle Cells in Human Gubernaculum Testis

Waldemar S. Costa; Francisco J.B. Sampaio; Luciano A. Favorito; Luiz E.M. Cardoso

PURPOSE We present the main morphological modifications in the human gubernaculum during testicular migration in humans. MATERIALS AND METHODS We obtained 12 gubernacula from fresh, macroscopically normal human fetuses at 15 to 29 weeks of gestation. Collagen was evidenced using trichrome and Sirius red staining procedures, while Weigerts resorcinol-fuchsin and anti-human elastin antibody were used to reveal elastic system fibers. Smooth muscle cells were detected by anti-human smooth muscle alpha-actin antibody. RESULTS When the testes were still located in the abdomen at 15 to 16 weeks of gestation, collagen fibers were sparse and embedded in a loose extracellular matrix. The amount of fibers then gradually increased with age and at 28 weeks of gestation the gubernaculum was mostly collagenous in composition. Elastic fibers had a similar growth pattern, although they were located mainly at the distal end of the gubernaculum. Fibroblasts largely predominated over other cell types and decreased in number with gestational age, whereas smooth muscle cells were restricted to the walls of blood vessels. Striated muscle cells were detected at the scrotal end of the gubernaculum, where they were disposed as isolated and scattered bundles running in various directions. Like fibroblasts, their number also decreased with age. CONCLUSIONS During testicular migration gubernacular connective tissue undergoes extensive remodeling and ultimately becomes an essentially fibrous structure rich in collagen and elastic fibers. Such changes should decrease the size of the gubernaculum and, thus, contribute to other forces that cause the testes to move toward the scrotum. In fact, because of the lack of smooth muscle cells, and the amount and organization of striated muscle cells, active contraction of the gubernaculum is less likely to be an important factor in testicular descent.


BJUI | 2002

Stromal and acinar components of the transition zone in normal and hyperplastic human prostate

Maurício A. Chagas; Marcio A. Babinski; Waldemar S. Costa; Francisco J.B. Sampaio

Objective To analyse the histological components of the transition zone in both normal human prostate and benign prostatic hyperplasia (BPH), and to determine the volumetric density (Vv) of the different elements (connective tissue, smooth muscle cells, acini and total stroma).


The Journal of Urology | 2000

ORGANIZATION AND RELATIVE CONTENT OF SMOOTH MUSCLE CELLS, COLLAGEN AND ELASTIC FIBERS IN THE CORPUS CAVERNOSUM OF RAT PENIS

Ana C.A.D. Pinheiro; Waldemar S. Costa; Luis Eduardo M. Cardoso; Francisco J.B. Sampaio

PURPOSE The corpus cavernosum smooth muscle and extracellular matrix are essential for normal penile erection and are implicated in erectile dysfunction. Although investigations of these issues have used the rat corpus cavernosum, organization of its components is to date not well known. We characterized and quantified the smooth muscle cells and the main extracellular matrix components of the rat corpus cavernosum. MATERIALS AND METHODS Collagen, elastic fibers and smooth muscle cells were stained on paraffin sections of rat penises using sirius red and Gomoris reticulin, Weigerts resorcin-fuchsin and an anti-smooth muscle cells alpha-actin antibody, respectively. Stained components were then quantified by computer aided morphometry. RESULTS Smooth muscle cells were restricted to the subendothelial space of corpus cavernosum and had a volumetric density of 9.1%. Collagen was thick, usually in transversely oriented bundles and was the most abundant component of the trabeculae with a volumetric density of 62.7%. Gomoris reticulin disclosed a meshwork of fibrils also in the subendothelial space but did not stain the thicker bundles. Volumetric density of elastic fibers was 4.9%, and at the periphery of the corpus cavernosum the fibers were parallel to the long axis of the penis, while in deeper regions most of them were transversely oriented and at different directions from those of collagen. CONCLUSIONS Rat corpus cavernosum differs from that of humans by lesser amounts of smooth muscle cells, greater amounts of collagen and the presence of fibrillar collagen and smooth muscle cell subendothelial layers. Therefore, these differences should be considered when using the rat penis for studies on erection.


Urology | 2004

Treatment of Recurrent Priapism in Sickle Cell Anemia With Finasteride: A New Approach

Daibes Rachid-Filho; Andre G. Cavalcanti; Luciano A. Favorito; Waldemar S. Costa; Francisco J.B. Sampaio

OBJECTIVES To determine whether the use of finasteride controls recurrent priapism in patients with sickle cell anemia. METHODS Thirty-five patients with recurrent priapism because of sickle cell disease received finasteride during 120 days. The initial dose was decreased every 40 days, from 5 mg/d to 3 mg and then to 1 mg of finasteride until the end of 120 days. Five groups (G) were created based on priapism episodes in a month: G0, no episode; G1, 1-15 episodes; G2, 16-30; G3, 31-45; and G4, >45 episodes. RESULTS Records on day 0: G0, no patient; G1, 7 (20%); G2, 21 (60%); G3, 4 (12%); and G4: 3 (8%). After 40 days of using 5 mg/d finasteride we found the following results: G0, 5 patients (14%); G1, 19 (55%); G2, 8 (23%); G3, 3 (8%); and G4, none. At the end of the 40-day period, using 3 mg/d finasteride, the findings were as follows: G0, 19 patients (55%); G1, 14 (39%); G2, 2 (6%); G3, none; and G4, none. The findings after 120 days with 1 mg/d finasteride for the last 40 days were as follows: 16 patients (46%) and G1, 16 (46%). In 1 patient, the dose was increased to 3 mg and in 2 patients, to 5 mg, so as to achieve remission. CONCLUSIONS To our knowledge, this is the first study demonstrating that the use of finasteride could decrease and control the number of priapism recurrences in patients with sickle cell anemia, with fewer side effects than other drugs currently used.


International Braz J Urol | 2004

Anatomic aspects of epididymis and tunica vaginalis in patients with testicular torsion

Luciano A. Favorito; André G. Cavalcante; Waldemar S. Costa

OBJECTIVE To analyze the morphology of epididymis and tunica vaginalis as well as their anatomical anomalies in patients with testicular torsion. MATERIALS AND METHODS We studied 25 patients (50 testes) aged between 12 and 23 years (mean 15.6). Torsion length ranged from 2 hours to 2 days (mean 8 hours). Epididymal anatomy was classified in 6 groups: Type I--epididymis united to the testis by its head and tail; Type II--epididymis totally united to the testis; Type III--disjunction of epididymal tail; Type IV--disjunction of epididymal head; Type V--total disjunction between testis and epididymis, and Type VI--epididymal atresia. The type of torsion was classified in 3 groups: Group A--intravaginal torsion; Group B--extravaginal torsion and Group C--torsion due to long mesorchium. RESULTS Of the 50 analyzed testes, 40 (80%) presented bell clapper deformity (with 21 presenting intravaginal torsion); 8 testes (16%) had long mesorchium (4 with torsion), and only 2 (4%) presented normal anatomy in the tunica vaginalis. The most frequently found anatomical relationship between testis and epididymis was Type I--38 cases (76%); Type II relationship was found in 6 cases (12%) and Type III relationship was found in 6 cases (12%). CONCLUSIONS Intravaginal torsion is the most frequent type, and torsion due to long mesorchium is associated with cryptorchism. The most frequently found anatomical relation between testis and epididymis in the study group was Type I.


BJUI | 2006

Comparative analysis of the penis corpora cavernosa in controls and patients with erectile dysfunction

Waldemar S. Costa; Fabricio B. Carrerete; Wagner G. Horta; Francisco J.B. Sampaio

To evaluate the presence of structural disorders of the corpora cavernosa in patients with erectile dysfunction (ED), as despite new drugs being effective in many men with ED, some aspects of structural disorders of the corpora cavernosa remain unknown.


International Braz J Urol | 2007

Applied Anatomic Study of Testicular Veins in Adult Cadavers and in Human Fetuses

Luciano A. Favorito; Waldemar S. Costa; Francisco J.B. Sampaio

OBJECTIVES Analyze the anatomic variations of the testicular veins in human cadavers and fetuses. MATERIALS AND METHODS One hundred male adult cadavers and 24 fetuses were studied. Four anatomic aspects were considered: 1) Number of testicular veins, 2) The local of vein termination, 3) Type and number of collaterals present and 4) Testicular vein termination angle. RESULTS Cadavers - Right side - One testicular vein occurred in 85% and 2 veins in 5% of the cases. There were communicating veins with the colon in 21% of the cases. Left side - One testicular vein occurred in 82%, two veins in 15%, three veins in 2% and four veins in 1% of the cases. There were communicating veins with the colon in 31% of the cases. Fetuses - Right side - One testicular vein occurred in all cases. This vein drained to the vena cava in 83.3% of the cases, to the junction of the vena cava with the renal vein in 12.5% and to the renal vein in 4.2%. There were communicating veins with the colon in 25% of the cases. Left side - One testicular vein occurred in 66.6% of the cases, and 2 veins in occurred 33.3%. Communicating veins with the colon were found in 41.6% of the cases. CONCLUSION The testicular vein presents numeric variations and also variations in its local of termination. In approximately 30% of the cases, there are collaterals that communicate the testicular vein with retroperitoneal veins. These anatomic findings can help understanding the origin of varicocele and its recurrence after surgical interventions.


BJUI | 2004

The concentration of elastic fibres in the male urethra during human fetal development.

Ana L. Bastos; Eloísio A. da Silva; Waldemar S. Costa; Francisco J.B. Sampaio

To describe the distribution of elastic fibres in the developing male urethra and to provide stereological data of the concentration of elastic fibres in the human urethra.


The Journal of Urology | 2000

PROXIMAL INSERTION OF GUBERNACULUM TESTIS IN NORMAL HUMAN FETUSES AND IN BOYS WITH CRYPTORCHIDISM

Luciano A. Favorito; Francisco J.B. Sampaio; Valter Javaroni; Luiz E.M. Cardoso; Waldemar S. Costa

PURPOSE We determine how the proximal gubernaculum testis is attached to the testis and epididymis in human fetuses, and compare these data with findings in boys who had undergone surgery for cryptorchidism. MATERIALS AND METHODS We analyzed 280 testes and epididymides with the gubernacula of 140 well preserved, fresh human fetuses ranging from 10 to 35 weeks after conception with no detectable congenital malformations and 36 undescended testes of 28 boys 2 to 15 years old (mean age 6.8) who had undergone surgery for cryptorchidism. In both groups the different conformations of the relationship among the proximal gubernaculum, testis and epididymis were classified according to a system used for patients with cryptorchidism. In group A the gubernaculum is attached to the testis and epididymis, in group B the gubernaculum is attached only to the testis with a tail disjunction epididymal anomaly, in group C the gubernaculum is attached only to the testis with total disjunction of the epididymis, in group D the gubernaculum is attached only to the epididymal tail and in group E there are no attachments among gubernaculum, testis and epididymis. RESULTS Of the 280 fetal testes studied 194 (69.2%) were in the abdomen, 38 (13. 57%) in the inguinal canal and 48 (17.14%) in the scrotum. There were 277 cases (98.9%) in group A and 3 (1.1%) in group B. Of the 36 undescended testes analyzed 2 (5.6%) were abdominal and 34 (94.4%) were inguinal. There were 26 cases (72.2%) in group A, 8 (22.2%) in group B and 2 in group D. CONCLUSIONS In fetuses without congenital malformations or epididymal alterations, such as tail disjunction or elongated epididymis, the proximal portion of the gubernaculum was attached to the testis and epididymis in all cases. In undescended testes there was an increased incidence of paratesticular structure malformations accompanied by gubernacular attachment anomalies compared to the testes in normal fetuses.

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Francisco J.B. Sampaio

Rio de Janeiro State University

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Luciano A. Favorito

Rio de Janeiro State University

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Diogo Benchimol de Souza

Rio de Janeiro State University

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C. Gallo

Rio de Janeiro State University

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Luiz E.M. Cardoso

Rio de Janeiro State University

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Bianca Martins Gregório

Rio de Janeiro State University

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Marco A. Pereira-Sampaio

Rio de Janeiro State University

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Marcio A. Babinski

Rio de Janeiro State University

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Cristiane da Fonte Ramos

Rio de Janeiro State University

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Andre G. Cavalcanti

Rio de Janeiro State University

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