Biomedical subjects

Luiz E M Cardoso

Publications and source records attributed to Luiz E M Cardoso.

5 recordsLinked to original sources

PubMed2005

Compositional changes of collagen and glycosaminoglycans in the tunica albuginea and corpus cavernosum from the human penis during the fetal and postnatal periods.

PURPOSE: We investigated the composition of collagen and glycosaminoglycans (GAGs) in the corpus cavernosum (CC) and tunica albuginea (TA) of normal human penises. MATERIALS AND METHODS: Penises were obtained from a 6-month-old child (group 1), a 2-year-old child (group 2), 18 to 34-year-old adults (group 3), 37 to 53-year-old adults (group 4) and 22 fetuses at 17.2 to 33.3 menstrual weeks (group 5). Total GAG and collagen concentrations were expressed per mg dry tissue and proportions of GAG species were determined by agarose electrophoresis and ion exchange chromatography. RESULTS: The GAG concentration in group 1 CC and TA was 1.32 and 0.52 microg/mg, respectively, and thereafter it increased noticeably. TA collagen concentration followed a similar pattern. TA had more collagen than CC in groups 3 (mean +/- SD 93.41 +/- 6.17 vs 53.77 +/- 11.18 microg/mg, p <0.001) and 4 (89.94 +/- 5.53 vs 55.39 +/- 5.89 microg/mg, p <0.01). In these groups TA and CC differed markedly in the proportion of hyaluronan, heparan sulfate and dermatan sulfate. In TA group 4 had slightly less hyaluronan and more chondroitin sulfate than group 3 but in CC the GAG proportions were similar. Collagen content in the whole fetal penis correlated with gestational age (r = 0.78, p <0.001). CONCLUSIONS: Collagen and the GAG concentration in the human penis undergo extensive modifications during development and shortly after birth but from ages 2 to approximately 46 years changes are limited to the proportion of GAG species in TA from older individuals. Reflecting diverse biomechanical roles, the extracellular matrix of CC and TA are markedly different.

Adolescent↗

PubMed2005

Urinary glycosaminoglycan excretion during the menstrual cycle in normal young women.

PURPOSE: We investigated whether the menstrual cycle affects urinary glycosaminoglycan (GAG) excretion in normal young women. MATERIALS AND METHODS: Urine samples from 10 healthy women 19 to 21 years old were collected daily during the whole menstrual cycle. Concentration of total urinary GAG was assessed as mug hexuronic acid per mg creatinine. Proportions of sulfated GAG species were determined by agarose gel electrophoresis. RESULTS: Mean excretion values +/- SD for period days 4 to 13 and 15 to 28 of the cycle were significantly different (0.445 +/- 0.041 vs 0.356 +/- 0.035 microg/mg, p <0.001). Correlation between values for the first and second halves of the cycle showed that this difference was consistent irrespective of individual variations in GAG excretion (r = 0.9757, p <0.001). Proportions of urinary sulfated GAG did not change during the cycle. CONCLUSIONS: Excretion of total urinary GAG during the normal menstrual cycle of young women has a biphasic pattern with significantly higher values occurring in the first half of the cycle. This variation implies modulation by estrogens and consequently it should be considered when comparing the GAG concentration in urine samples from women of childbearing age.

Adult↗

PubMed2002

Regional differences in the extracellular matrix of the human spongy urethra as evidenced by the composition of glycosaminoglycans.

PURPOSE: Despite the concept that the spongy urethra is a unique entity clinical evidence suggests the existence of segmental structural differences. The spongy urethra has a vascular nature, its cells may express different phenotypes and the extracellular matrix that they synthesize should reflect these differences. Glycosaminoglycans are components of the extracellular matrix that have key roles in the normal physiology and pathology of several tissues. Although total collagen content of the urethra was determined, we also analyzed urethral glycosaminoglycans (GAGs). MATERIALS AND METHODS: Fresh, macroscopically normal cadaveric urethral samples were obtained from 15 men who died at a mean age of 25.4 years. The urethra was divided into glanular, penile and bulbar segments, which were then analyzed separately. Total GAG concentration was assessed by hexuronic acid assay and expressed as microg. hexuronic acid per mg. dry tissue, while the proportions of sulfated GAGs were determined by agarose gel electrophoresis. Hyaluronan concentration was determined by ion exchange chromatography and total tissue collagen was estimated as hydroxyproline content. RESULTS: Total GAG concentration was heterogeneous along the spongy urethra (p <0.001). Mean values plus or minus standard deviation in the glanular, penile and bulbar segments were 2.53 +/- 0.42, 2.11 +/- 0.47 and 1.47 +/- 0.4 microg./mg., respectively. The most predominant GAG was hyaluronan and its highest mean concentration of 50.1% +/- 3.7% was found in the glanular urethra. The most predominant sulfated GAG in the male urethra was dermatan sulfate, followed by chondroitin sulfate and heparan sulfate. Total collagen content and the GAG-to-collagen ratio varied along the spongy urethra and were lowest in the bulbar segment. CONCLUSIONS: The extracellular matrix of the human spongy urethra shows regional differences, as evidenced by biochemical analysis of GAG and collagen. This heterogeneity implies functional adaptations in the various segments and may affect the physiology and segmental incidence of urethral diseases.

Adolescent↗

PubMed2002

Testicular migration: remodeling of connective tissue and muscle cells in human gubernaculum testis.

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 Weigert's 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.

Connective Tissue↗

PubMed2002

Extracellular matrix changes in urethral stricture disease.

PURPOSE: Glycosaminoglycans (GAGs) and collagen are major components of the extracellular matrix and they have key roles in fibrotic diseases. Little is known about the molecular environment in urethral stricture and the majority of the studies available focused on collagen analysis. However, to our knowledge there are no data on GAG composition in urethral stricture disease. MATERIALS AND METHODS: Bulbar urethral strictured segments were obtained from 10 patients 18 to 61 years old (mean age 41.8) who underwent end-to-end anastomotic urethroplasty. GAGs in dry tissue samples were extracted by papain digestion and cetylpyridinium chloride/ethanol precipitation. The concentration of total GAGs was assessed by hexuronic acid assay and expressed in microg. hexuronic acid per mg. dry tissue, while the proportion of sulfated GAGs was determined by agarose gel electrophoresis. The concentration of hyaluronic acid was determined by ion exchange chromatography and total tissue collagen was estimated as its hydroxyproline content. The control group consisted of 10 bulbar urethras obtained from fresh normal cadavers 22 to 53 years old (mean age 32.8). RESULTS: Mean total GAG concentration plus or minus standard deviation in the stricture group was 1.09 +/- 0.13, which was significantly lower than in controls (p <0.05). While the predominant GAG in normal bulbar urethras was hyaluronic acid, dermatan sulfate predominated in strictured urethras (mean 44.1% +/- 8.4 and 45.6% +/- 7.7%, respectively). Hyaluronic acid decreased 49.9% and dermatan sulfate increased 68.3%. There were no significant changes in the concentration of heparan sulfate or chondroitin sulfate in normal and strictured bulbar urethras. Mean total collagen significantly increased 32.3% (p <0.05). CONCLUSIONS: Composition changes in GAGs in strictured urethras could contribute to the noncompliant nature of urethral scar tissue and cause functional changes. These results may be useful for defining new targets for therapy for urethral stricture disease.

Adolescent↗