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J P Vanegas

Publications and source records attributed to J P Vanegas.

9 recordsLinked to original sources
PubMed1998

Corporeal veno-occlusive dysfunction: a distal arterial pathology?

PURPOSE: Alteration of intracavernous smooth muscle cells has been demonstrated in patients with pure venous leakage. This modification seems correlated with reduction of intracavernous oxygen tension. However, Doppler imaging of the cavernous arteries in these patients is normal. To understand the ischemic factor we studied the endothelium of the terminal arteries with computerized image analysis and immunohistochemical staining with 2 types of lectin in patients with venous leakage and those with normal erections. Lectins are glycoproteins that can be used as histological markers to monitor functional and pathological changes. MATERIALS AND METHODS: Four patients 44 to 59 years old with normal erections who were operated on for penile cancer and 11 patients 27 to 62 years old with pure venous leakage (flow to maintain erection greater than 15 ml. per minute and cavernous flow velocity greater than 35 cm. per second) were included in the study. Immunohistochemical staining with 2 lectins, wheat germ agglutinin and Ulex europeaus agglutinin I, was performed and analyzed with computerized image analysis. The labeling index which relates to the percentage of staining indicates the distribution of the endothelial cells, and mean optical density which relates to the staining intensity indicates the function of these cells. RESULTS: Mean labeling index values for the 2 lectins were similar in both groups (p >0.05). Mean optical density values for the 2 lectins were significantly greater for the patients with normal erections (p <0.01). Therefore, the distribution of the endothelial cells was the same while their function was different in patients with corporeal veno-occlusive dysfunction. CONCLUSIONS: Staining with wheat germ agglutinin and Ulex europeaus agglutinin I lectin types allowed us to detect alteration in the glyco-histochemistry of the endothelial cells of the small arteries, and venous leakage could be the first step in vasculogenic impotence.

Adult↗
PubMed1997

Objective measurement of the different collagen types in the corpus cavernosum of potent and impotent men: an immunohistochemical staining with computerized-image analysis.

Quantitative measurements of the collagen types (I, II, and IV) in the corpora cavernosa of potent and impotent men were carried out to investigate whether quantitative immunohistochemistry might contribute additional information as to the cause of erectile dysfunction. The study group consisted of 22 men with various etiologies of impotence and 4 normal, potent men. The quantitative immunohistochemistry measurements were performed by means of a cell-image processor. Three variables for each of the three types of collagen were studied, namely, the mean optical density (MOD), which relates to histochemical staining intensity; the labeling index (LI), which is positively related to the percentage of immunostaining; and the quick score (QS) index, which takes into account both LI and MOD values. None of the quantitative parameters taken individually (monovariate statistical analyses) made it possible to obtain any statistically significant difference between the types of collagen of the group under study. The mean QS value recorded for collagen type IV was significantly lower than that noted for collagen type I in the psychogenic (P = 0.019), arteriogenic (P = 0.012), and venogenic (P = 0.001) groups, whereas the MOD value was significantly lower in the normal (P = 0.043), arteriogenic (P = 0.013), and venogenic (P = 0.001) groups but not in the psycogenic group. The mean MOD of collagen type III was intermediate between that of the other types. In contrast, the mean LI value recorded for collagen type IV was significantly lower only in the venogenic (P = 0.032) and psychogenic (P = 0.049) groups as compared with the other groups. No objective qualitative change in the collagen types was observed that could be correlated to the etiology of erectile dysfunction. The significant difference seen in the quantitative parameters with regard to collagen type IV and the observed increase in the type I/III collagen ratio might attest to the notion that the response of the erectile tissue to ischemia is similar to that of other organs. The net effect of these changes is a restricted capacity for corporal expansion and alteration of the veno-occlusive mechanism.

Adult↗
PubMed1997

Biochemical alterations of the tunica albuginea in impotence.

PURPOSE: The objectives of this study were to quantify the immunohistochemical stainings of collagen types I, III and IV, and investigate the value of glycohistochemical staining with 3 lectin types specific to a particular glycan structure, Arachis hypogaea, Triticum vulgare and concanavalin A, as a method of defining possible changes in the collagen structure of the tunica albuginea in potent and impotent patients. MATERIALS AND METHODS: The study involved 4 normal men, 4 with pure venous leakage and 4 with pure arterial disease. Collagen types I, III and IV, and lectins Arachis hypogaea, Triticum vulgare and concanavalin A were studied using a cell image processor. The labeling index relates to the percentage of staining and mean optical density relates to the staining intensity. RESULTS: Mean labeling index values for the 3 types of collagen and lectins were similar (p > 0.05). Mean optical density value relating to collagen type I was significantly higher in the arteriogenic group than in the other groups (p < 0.05), while mean optical density value of collagen type IV was significantly higher in the venogenic group than in the 2 other groups (p < 0.05). Mean optical density values relating to the 3 lectin types were similar in the 3 clinical groups (p > 0.05). CONCLUSIONS: An alteration in the distribution and structure of the various collagen types and lectins in the tunica albuginea of impotent patients has been shown that may interfere with normal function and lead to impotence.

Adult↗
PubMed1996

Do prostate specific antigen and prostate specific antigen density enhance the detection of prostate carcinoma after initial diagnosis of prostatic intraepithelial neoplasia without concurrent carcinoma?

BACKGROUND: Prostatic intraepithelial neoplasia (PIN) is considered to be a precursor of prostate carcinoma in which serum levels of prostate specific antigen (PSA) have been correlated with PIN grades. The aim of this study was to determine whether PSA and prostate specific antigen density (PSAD), obtained at the time of initial diagnosis of PIN without concurrent carcinoma, can be used as predictive factors to discriminate patients with subsequent cancer on repeat biopsy. METHODS: We studied, retrospectively, the records of 93 patients with PIN (low and high grade) without concurrent carcinoma at the time of their first needle biopsy. We assessed the relationship between initial PIN grade, PSA, and PSAD with later detection of carcinoma on repeat biopsy. Patients were divided into 3 subgroups for analysis according to their initial PSA level (0-4, 4.1-10, >10 ng/mL). RESULTS: Carcinoma detection rate on repeat biopsy was 13.3% for patients with low grade PIN and 47.7% for patients with high grade PIN (P < 0.006). High grade PIN was frequently associated with subsequent carcinoma whatever the PSA level (33.3-61.9%). Low grade PIN was associated with subsequent carcinoma in 42.8% of the cases when PSA was greater than 10 ng/mL. When PSA was between 4 and 10 ng/mL, low grade PIN carcinoma was found on repeat biopsies in only 10.7% of the cases (P = 0.05). In none of the PSA subgroups did PSAD enhance later cancer detection. CONCLUSIONS: For patients with high grade PIN, the incidence of subsequent carcinoma is high, whatever the PSA values. For these cases repeat biopsies should be recommended. Patients with low grade PIN and PSA greater than 10 ng/mL should have repeat biopsies because the incidence of subsequent carcinoma is high and comparable to high grade PIN. PSAD did not provide additional information.

Biopsy, Needle↗
PubMed1996

Differential histochemical peanut agglutinin stain in benign and malignant human prostate tumors: relationship with prostatic specific antigen immunostain and nuclear DNA content.

The histochemical binding pattern of the peanut (Arachis hypogaea) lectin (PNA) was quantitatively described by means of computer-assisted microscope analysis in 28 benign prostatic hyperplasias (BPH), 15 prostatic intraepithelial neoplasias (PIN), and 119 prostatic adenocarcinomas. PNA exhibits nonimmune but selective binding to glycoproteins with beta-D-galactosyl(1,3)-N-acetyl-D-galactosamine residues. We also investigated whether a relationship existed between the number of histochemical-related PNA acceptors and the histochemical prostate-specific antigen (PSA) stain intensity, and between the number of PNA receptors and DNA ploidy level. The results show that neoplastic prostate tissues and high-grade intraepithelial prostatic neoplasias (PIN2_3) exhibit a significantly higher number of PNA acceptors than benign prostatic hyperplasias and low (PIN1) grade prostatic intraepithelial neoplasias. A statistically significant correlation was observed between the number of histochemically related PNA acceptors and PSA immunostain intensity. Lastly, diploid prostatic tumors, whether benign or malignant, exhibited a significantly higher number of PNA acceptors than aneuploid ones. These results suggest that PNA acceptors play an important role in the biology of prostate tumors.

Adenocarcinoma↗
PubMed1996

[A new method of cancer treatment: the use of radiofrequencies in urological tumors].

This study reports our preliminary experience with interstitial radiofrequencies in the treatment of urological malignancies. Bipolar radiofrequency was interstitially delivered in four freshly removed human kidneys in an ex-vivo model. The kidney was perfused ex-vivo with 37 degrees C saline in order to mimic physiological conditions. Large reproducible and controlled lesions (hypereosinophilia and pyknosis) were observed in the parenchyma between the active needles. Further animal and human clinical studies are planned to precise the place of bipolar RF in the treatment or urological malignancies, and especially in kidney tumors.

Electrocoagulation↗
PubMed1996

[Intra-cavernous collagen analysis in impotence].

The role of the different components of the corpus cavernosum is very important in the physiopathology of erectile dysfunction. The precise function of collagen fibers in erectile physiology is controversial. We measured the different types of collagen (I, III, IV) in the corpus cavernosum of 26 impotent and potent men using cell image analysis and immunohistochemistry. We found differences in the distribution of collagen I, III, IV in each pathological group (arterial, caverno-venous, psychogenic). The augmentation of collagen I and the light diminution in collagen III makes the corpus cavernosum less compliant which translates clinically as an alteration in the filling of the vascular spaces and by dysfunction of the veno-occlusive mechanism. The diminution in collagen IV shows an alteration in the function of endothelial cells. The fact that in the psychogenic group we found also a diminution in collagen IV content, makes us infer that psychogenic impotence could be the first stage of an organic impotence.

Adult↗
PubMedDate not supplied

Difference in glycohistochemical lectin staining of collagen fibers in the corpora cavernosa of normal and impotent men.

The objectives of this study were to investigate the value of glycohistochemical staining with three lectin types specific to a particular glycan structure (Arachis hypogaea [PNA], Triticum vulgare [WGA], and concanavalin A [Con A]) as a method of defining possible changes in the collagen structure in the corpora cavernosa in potent and impotent men. The study group consisted of 4 normal potent men and 22 men with various etiologies of impotence. The quantitative histochemical measurements were performed by means of a cell image processor. Two variables for each of the three types of lectins were studied. These were the mean optical density (MOD), which relates to glycohistochemical staining intensity, and the labeling index (LI), which is positively related to the percentage of immunostaining. Only WGA staining made it possible to discriminate significantly between the normal and pathological groups under study. The two parameters (LI, MOD) were significantly higher in the case of WGA staining in the normal group (P = 0.004 and 0.013, respectively). In contrast, only the mean LI value, in the case of the psychogenic and venogenic patients, reached a level of statistical significance (P = 0.005 and 0.001, respectively), when it increased from PNA through WGA to Con A histochemical staining. The two variables (LI, MOD) changed markedly from PNA through WGA to Con A in the arteriogenic patients (P = 0.003 and P < 0.001, respectively). WGA is of diagnostic value in distinguishing between normal and abnormal collagen in the corpora cavernosa. The difference in the lectin staining of the other groups, particularly the arteriogenic group, may be attributed to alterations in the glycosylation of the procollagen that are probably due to changes in the partial pressure of oxygen (PO2) level, an important cofactor in normal glycosylation. WGA staining may therefore be used as a marker to distinguish true psychogenic patients from those with organic diseases. Moreover, it may be used as an additional parameter in selecting the best candidates for penile revascularization.

Adult↗