PubMed Health⌕ Search

Biomedical subjects

A de las Morenas

Publications and source records attributed to A de las Morenas.

At least 19 recordsLinked to original sources
PubMed2006

Quantitative analysis of allele imbalance supports atypical ductal hyperplasia lesions as direct breast cancer precursors.

It remains unclear whether hyperplastic breast lesions, especially with atypia, are cancer precursors or markers of increased cancer risk. Quantified comparisons of genomic alterations in coexisting lesions could address this question. Therefore, we examined allele imbalance (AI), also known as loss of heterozygosity (LOH), at 20 microsatellite markers on nine chromosome arms, in DNA from 106 samples microdissected from 17 randomly selected cancer-containing breast specimens: 13 simple (DH) and 45 atypical ductal hyperplastic (ADH) lesions, 30 in situ (DCIS) and 18 invasive ductal carcinomas (IDC). Data were analysed using regression models and generalized estimating equations. We found that AI increased as histology became more aberrant and varied with histology across the chromosome arms (p<0.0001). ADH had more AIs on 1q (p=0.03) and 16q (p=0.02) and fewer AIs on 17p (p=0.06) and 17q (p<0.0001) than on other arms. In cancers, AIs remained high on 1q and 16q, and became frequent on 17p and 17q. Concordance between AIs in ADHs and cancers exceeded the 50% expected if the lesions were separate clones in 16/20 (80%) ADHs (p=0.05), from 9/11 (82%) cases (p=0.03), and involved 41/51 (80%) evaluable markers (p=0.05). The occurrence of any AI in ADH predicted greater AI (p=0.009) and possibly lower grade (p=0.05) in coexisting cancers. Nevertheless, ADHs were not genetically identical to cancers or to each other. We found AIs discordant between ADHs and cancers (always on 1q and 16q), AIs unique to ADH (usually on 11q) and some genetic heterogeneity among coexisting ADHs. We conclude that ADH lesions are genetically advanced, with frequent alterations on 1q and 16q, and are often direct cancer precursors. Their global genetic characteristics predict features of cancers in the same breast. Nevertheless, the genetic heterogeneity detected suggests that hyperplasias and cancers may arise on a field at generalized increased cancer risk.

Adult↗
PubMed2001

Twenty-one-gauge needles provide more cellular samples than twenty-five-gauge needles in fine-needle aspiration biopsy of the thyroid but may not provide increased diagnostic accuracy.

The technique of fine-needle aspiration (FNA) biopsy of the thyroid is important to evaluate malignancy in thyroid nodules. Eighty-five percent of thyroid FNA procedures lead to sufficient cellular material for diagnosis. With more cells aspirated, the chance of sufficiency for diagnosis increases. Large-bore needles lead to more cellular material being aspirated but bloodier specimens that may interfere with cytologic interpretation. Small-bore needles may result in too few cells for diagnosis. We conducted a randomized prospective study contrasting 21-gauge and 25-gauge needles in the evaluation of 50 consecutively enrolled nodules at our institution. In our investigation, 21-gauge needles more frequently provided superior biopsy specimens (50%) than did 25-gauge needles (18%). In the remaining specimens (32%), the 21-gauge and 25-gauge needles provided similar cellular material. The rate of sufficient samples was the same. We conclude that use of 21-gauge needles results in more cellular specimens but may not result in increased diagnostic accuracy.

Biopsy, Needle↗
PubMed1999

Lack of correlation between morphometric analysis and presence of microsatellite alterations in proliferative ductal lesions of the breast.

OBJECTIVE: To apply morphometric studies using an image analyzer to a previously reported group of proliferative duct lesions and to compare results to see if there was a correlation between nuclear size range and monoclonality. STUDY DESIGN: Fifteen proliferative lesions of the breast from 12 subjects who had no history of breast malignancy were retrieved from archival pathology specimens. Evidence of monoclonality was studied using a panel of polymerase chain reaction primers to examine microsatellite alterations on microdissected paraffin-embedded specimens. Variation in nuclear size was studied using an image analyzer. RESULTS: Of six proliferative breast lesions with demonstrated genetic instability, three showed cytologic evidence of uniformity in nuclear size, a cytologic feature of malignancy. One of the six, which showed microsatellite alterations at three loci, demonstrated a wide range of nuclear size variation. Of the eight proliferative lesions that showed no genetic instability, three showed very uniform nuclear size, and five showed significant variations in nuclear size. One lesion, which fell into the "uncertain but probably genetic instable" category, showed diverse nuclear size ranges. CONCLUSION: This study demonstrated that there is no correlation between monoclonality and monomorphic cell cytology of histologic proliferative breast lesions.

Breast↗
PubMed1998

Fine-needle aspiration cytology diagnosis of colloid nodule versus follicular variant of papillary carcinoma of the thyroid.

The cytologic differential diagnosis of colloid nodule (CN) and the follicular variant of papillary carcinoma (FVPC) is difficult with common morphologic features. To assess the utility of 18 cytologic morphometric parameters in the diagnosis of these thyroid lesions we evaluated 31 FNA samples that had histologic confirmation of the diagnoses. These 31 cases included 15 cases of CN, 8 cases of FVPC, and 8 cases of the usual variant of papillary carcinoma (UVPC) for reference values. For the morphometric analysis we used an Optimas 4.0 image analysis system. Comparing the CN group with the UVPC group revealed that eight of the parameters had statistically significant differences. The UVPC specimens were more cellular, less cohesive, had presence of papillary cellular groups more frequently, larger nuclei (UVPC: 109.33 +/- 30.19 microns2; CN: 66.81 +/- 15.02 microns2), higher nuclear to cytoplasmic (N/C) ratio, larger nucleoli, and present nuclear grooves and nuclear pseudoinclusions more frequently. The FVPC group differed from the CN group only in three parameters which included larger nuclei (98.49 +/- 18.24 microns2), higher N/C ratio, and a more frequent presence of nuclear pseudoinclusions. When we compared these two variants of papillary carcinoma, we found that the UVPC specimens had less cellular cohesion, less preservation of the architectural polarity and a more frequent presence of papillary cellular groups than the FVPC. The FVPC can be differentiated from CN based on nuclear changes, which included a larger size, higher N/C ratio, and presence of pseudoinclusions. The absence of cellular cohesion and polarity combined with the presence of papillary groups are useful in separating the UVPC from the FVPC. A cutoff of 75 microns2 should be used in separating benign from malignant nuclei.

Biopsy, Needle↗
PubMed1998

Genetically abnormal clones in histologically normal breast tissue.

Breast cancer is believed to develop as multiple genetic abnormalities accumulate, each conferring some growth advantage, but the timing and nature of the earliest steps in this progression are not yet elucidated. Proliferative breast lesions, associated with an increased risk of breast cancer although considered benign, recently were shown to contain clonal genetic abnormalities. Therefore, we hypothesized that clonal genetic abnormalities might be detectable before any phenotypic abnormalities are evident, ie, in histologically normal breast tissue. We examined DNA extracted from 95 normal-appearing breast ducts or terminal ductal-lobular units from 20 individuals at varying degrees of risk (those undergoing reduction mammoplasties, those with atypical hyperplastic proliferative lesions, and those already diagnosed with breast cancer). Using nine microsatellite markers, we sought evidence of genetic instability or of allelic imbalance (most likely representing loss of heterozygosity). We found genetically abnormal clones in 21/95 (22%) seemingly normal samples from 10/20 (50%) women from all three risk groups. In women under age 50, trends toward increased rates of abnormalities were noted with increased cancer risk. The abnormalities identified were more likely to be at sites of known or postulated tumor suppressor genes rather than at random or neutral loci. Our data indicate that genetic abnormalities potentially critical to breast tumorigenesis accumulate before pathological detection even of high-risk lesions and are detectable in tissue that is not only histologically benign but also completely normal.

Adult↗
PubMed1996

Detection of monoclonal microsatellite alterations in atypical breast hyperplasia.

Atypical hyperplastic (AH) breast lesions are currently classified and treated as benign proliferative disorders, but their presence is associated with a four- to fivefold increased risk of developing breast cancer. Currently, it is not known if an AH lesion is a marker of increased risk, or is itself a premalignant lesion. To investigate this question, we used a series of 15 microsatellite loci to analyze 15 separate AH lesions microdissected from the archived pathology specimens of subjects with no coincident or previous breast malignancy. We found that a significant subset (6/15, or 40%) of these AH lesions demonstrated evidence of monoclonal microsatellite alterations, both length variation and allele loss. These monoclonal alterations suggest that the AH lesion has already undergone genetic changes conferring a growth advantage. Thus, these AH lesions may actually be early neoplasms. We also noted that monoclonality characterized AH lesions in younger as compared with older women (44 vs. 59 yrs, P < 0.05) and that a subset of monoclonal lesions (4/6) demonstrated microsatellite alterations at more than one locus, suggesting that an undetermined type of genetic instability may play a role early in the development of abnormal breast proliferations. These findings contribute to our understanding of the pathogenesis of AH lesions and may have implications regarding their relationship to breast tumors.

Adult↗
PubMed1996

Mechanisms of venous leakage: a prospective clinicopathological correlation of corporeal function and structure.

PURPOSE: We investigated the pathophysiology of structurally based corporeal veno-occlusive dysfunction. MATERIALS AND METHODS: We prospectively evaluated 24 impotent patients (mean age plus or minus standard error 46 +/- 3 years) who had exposure to vascular risk factors and/or disorders inducing diffuse trabecular structure alterations and who underwent penile prosthesis insertion. Preoperative indexes of veno-occlusive function (flow to maintain, venous outflow resistance and pressure decay measurements using repeat dosing pharmacocavernosometry) were correlated with postoperative erectile tissue computer assisted color histomorphometry (percent trabecular smooth muscle to total erectile tissue area). To develop further study findings and correlate histomorphometric findings with molecular biological properties molecular biological studies (ribonuclease protection analysis, reverse transcription-polymerase chain reaction assay for expression of transforming growth factor-beta 1 messenger [m] ribonucleic acid [RNA] and protein affinity labeling techniques for specific transforming growth factor-beta receptors) were performed in representative patients with high (39 to 43%), intermediate (30 to 37%) and low (13 to 29%) trabecular smooth muscle content (normal 42 to 50%). RESULTS: Flow to maintain, venous outflow resistance and pressure decay values significantly correlated with trabecular smooth muscle cell content (r = -0.89, 0.82 and -0.85, respectively). In the high, intermediate and low smooth muscle content subgroups flow to maintain, venous outflow resistance and pressure decay values were 1 to 5, 9 to 30 and 50 to 120 ml. per minute, 17 to 84, 3 to 9 and 1 to 2 mm. Hg/ml. per minute, and 40 to 60, 48 to 80 and 110 to 120 mm. Hg decrease in 30 seconds from 150 mm. Hg, respectively. There were no significant differences in patient age or prevalence of risk factors among the 3 subgroups. Patients representative of all 3 subgroups had transforming growth factor-beta 1 mRNA, auto-induction of transforming growth factor-beta 1 mRNA and induction and/or increased availability of all 3 types of transforming growth factor-beta receptors. CONCLUSIONS: The pathophysiology of structurally based corporeal veno-occlusive dysfunction is related to elevated corporeal connective tissue content. Based on our data and those in the literature corporeal fibrosis is hypothesized to develop secondary to abnormalities in the regulation of normal collagen synthesis and degradation, most likely associated with adverse influences of chronic ischemia.

Adult↗
PubMed1996

Implications of prostate micrometastases in pelvic lymph nodes: an archival tissue study.

OBJECTIVES: In the United States, radical retropubic prostatectomy for adenocarcinoma usually includes a staging pelvic lymphadenectomy. If frozen section analysis of the lymph nodes fails to reveal any evidence of metastases, the prostate is removed. We have previously noted that as many as 56% of patients undergoing radical prostatectomy demonstrate rising serum prostate-specific antigen (PSA) levels by 4 years postoperatively. This report was designed to determine whether micrometastases undetectable by conventional pathologic methods: could have accounted for these biochemical failures. METHODS: A retrospective analysis of formalin-fixed paraffin-embedded pelvic lymph node material was undertaken using a reverse transcription-polymerase chain reaction (RT-PCR)-based assay designed to amplify messenger RNA from PSA. All specimens were obtained from a group of 57 patients with prostate cancer who had undergone staging pelvic lymphadenectomy at the time of radical prostatectomy, and whose long-term follow-up was known. RESULTS: Although all of these nodes appeared to be free of tumor by conventional pathologic methods, a RT-PCR assay was used to identify evidence of prostate metastases in 44% of evaluable samples. Of these, 14 of 16 went on to manifest rising serum PSA values by 5 years postoperatively. CONCLUSIONS: These results suggest that molecular staging of pelvic lymph nodes prior to planned therapy for clinically organ-confined prostate cancer may better distinguish between patients with local disease and those for whom local therapy alone will not be curative. To our knowledge, this is the first large-scale retrospective gene expression study published.

Adenocarcinoma↗
PubMed1995

Two separate domains of laminin promote lung organogenesis by different mechanisms of action.

Laminin is a major component of basement membranes. We previously reported that the globular region of laminin B chain(s) and the cross region of the A chain play an active role in mouse lung branching morphogenesis. In this study, basic morphogenic cell behaviors modulated by laminin were analyzed in order to elucidate how this glycoprotein promotes lung development. Cocultures of epithelial and mesenchymal cells from mouse fetal lungs were used to determine the effect of site-specific monoclonal antibodies to laminin (AL-1, AL-2, AL-3, AL-4, and AL-5) on epithelial and mesenchymal cell adhesion, proliferation, and organotypic rearrangement. We found that monoclonal antibody AL-1, directed against the cross region of the laminin A chain, inhibited epithelial and mesenchymal cell attachment and had a selective antiproliferative effect on epithelial cells. In contrast, monoclonal antibody AL-5, directed against the globular region of the B chain(s), blocked epithelial cell polarity. Immunohistochemical studies on epithelial-mesenchymal cocultures exposed to monoclonal antibody AL-5 revealed the absence of laminin deposition at the epithelial-mesenchymal interface, whereas type collagen IV was present at this site. These findings suggest that each of the two laminin domains involved in lung development promotes morphogenesis by a different mechanism of action. The cross-region of the A chain mediates cell adhesion and epithelial cell proliferation, whereas the globular region of the laminin B chain(s) is critical for the process of basement membrane assembly and cell polarization. The combined effect of both laminin domains on epithelial and mesenchymal cells and on the interaction between them seems to be essential for normal lung branching morphogenesis.

Amino Acid Sequence↗
PubMed1995

A rapid and simple method for the detection of prostate-specific antigen mRNA in archival tissue specimens using a reverse transcription-polymerase chain reaction assay.

OBJECTIVES: Polymerase chain reaction (PCR) amplification of DNA from archival, fixed tissue sources is now performed routinely. In this report, we describe a reproducible technique for mRNA amplification from archival tissues. METHODS: Archival, fixed tissue was treated with a modification of a rapid, acid guanidinium technique. The RNA yielded was reverse transcribed and subjected to 40 cycles of two-step PCR, using a panel of primers designed to encompass relatively short (less than 250 bp) cDNA fragments. PCR products were analyzed by agarose gel electrophoresis followed by ethidium bromide staining. RESULTS: Using fixed, paraffin-embedded specimens of human prostate, we have demonstrated a reproducible pattern of reverse transcription (RT)-PCR products using several different primer sets. Our data suggest that RNA degradation proceeds to fragments approximately 250 bp or shorter in length but that many of these fragments survive intact over extended periods of time and are of suitable quality to serve as a template for RT and subsequent PCR amplification. CONCLUSIONS: We describe a technique that will allow the retrospective analysis of archival tissues for gene expression. These methods are generally applicable to a wide variety of systems. Such a method will make it possible to perform retrospective studies of gene expression in the archival tissues of patients whose eventual clinical course is already known, greatly shortening the time needed for genetic outcome studies in slowly growing tumors, such as prostate cancer.

Base Sequence↗
PubMed1995

Extensive corporeal fibrosis after penile irradiation.

A potent man with early signs and symptoms of Peyronie's disease 3 months in duration received 1,200 rad of external beam radiation to the penis and presented 5 months later with impotence. Physical examination revealed diffusely woody indurated corporeal tissue. Nocturnal penile tumescence testing was abnormal and pharmaco-cavernosometry demonstrated diffuse corporeal veno-occlusive dysfunction. Treatment by penile injections was unsuccessful. During penile prosthesis implantation bilateral rubbery erectile tissue was encountered, requiring extensive bilateral corporotomy and sharp corporeal tissue excision for prosthesis insertion. Histological analysis of excised corporeal tissue demonstrated extensive corporeal fibrosis and arterial vasculopathy. Computer assisted color histomorphometry revealed that the mean percentage of trabecular smooth muscle area to total erectile tissue area was 26.5 +/- 15.8 (normal 40 to 52%). Immunohistochemical staining with desmin confirmed extensive fibrosis. The most likely explanation for severe corporeal fibrosis is penile irradiation. The hypothesized mechanism of radiation associated fibrosis is ionizing injury to the endothelial cells of the lacunar spaces and cavernous/helicine arteries, which induced irreversible corporeal extracellular matrix structural changes. Penile irradiation, like vascular disease and priapism, is a potential cause of diffuse corporeal fibrosis.

Adult↗
PubMed1995

Systemic sclerosis and impotence: a clinicopathological correlation.

A hypothesis of the mechanism of systemic sclerosis associated impotence was developed by making a clinicopathological correlation between the results of preoperative erectile function testing and those of pathological examination of excised erectile tissue in an impotent man with systemic sclerosis. Preoperative examination revealed firm corporeal tissue with diminished penile stretch capability. Pharmacocavernosometry/pharmacocavernosography under conditions consistent with trabecular smooth muscle relaxation revealed severe diffuse corporeal veno-occlusive dysfunction. During penile implantation surgery the compact erectile tissue was unable to be dilated and required sharp corporeal tissue excision under direct vision to achieve cylinder insertion. Histological investigation of the excised corporeal tissue demonstrated severe corporeal fibrosis. Computer assisted color histomorphometry revealed that the mean percentage of trabecular smooth muscle area to total erectile tissue area was 18.2 +/- 13.9% (normal 40 to 52). Immunohistochemical staining with desmin, a protein found in smooth muscle, verified prolific corporeal fibrosis. In situ hybridization of the corporeal tissue demonstrated messenger ribonucleic acid collagen and fibronectin messenger ribonucleic acid expression. Strong hybridization signals were found in mesenchymal cell types, including trabecular smooth muscle cells. In summary, clinicopathological correlation revealed that veno-occlusive dysfunction and loss of penile length were secondary to the excessive accumulation of extracellular matrix, partially due to trabecular smooth muscle cells undergoing synthetic as opposed to contractile phenotypic activity.

Adult↗
PubMed1992

Monoclonal antibodies to human endothelin-1: characterization and utilization in radioimmunoassay and immunocytochemistry.

A host of monoclonal antibodies directed against human endothelin-1 (ET-1) has been developed and characterized. The antibodies reacted with ET-1 specifically and with high affinity, as determined by competition analysis and sucrose density gradients. The antibodies did not cross-react with neuropeptide YY, beta-endorphin, calcitonin gene-related peptide, secretin or somatostatin. The antibodies cross-reacted with big endothelin (B-ET), endothelin-2 (ET-2), vasointestinal constrictor peptide (VIC), and endothelin-3 (ET-3) albeit with varying affinity but did not cross-react with sarafotoxin (SRTX-6b). None of the antibodies reacted with the C-terminal hexapeptide (HXPT) of ET-1, indicating that the epitopes are not located within this region of ET-1. The monoclonal antibodies exhibited binding activity in dilutions ranging from 1:1000, to 1:10(6). The isotypes of the monoclonal antibodies were determined by competition binding assay. Six of the monoclonal antibodies were of the IgG gamma 1, two were IgM and one of the IgG gamma 2a subclass. The antibodies detected immunoreactive ETs by radioimmunoassay and in immunocytochemical localization, suggesting the potential use of these antibodies as tools to determine the concentration of ETs in biological fluids and in immunocytochemical localization of ETs in specific cell types in various tissues.

Amino Acid Sequence↗
PubMed1991

Primary angiosarcoma of the seminal vesicle.

We report on an unusual case of primary angiosarcoma of the seminal vesicle. Diagnosis was confirmed by light and electron microscopy, as well as specific immunohistochemical staining. This rare tumor is highly aggressive, and refractory to traditional surgical and adjuvant therapeutic modalities. Sarcomatous lesions of the seminal vesicle are reviewed.

Brain Neoplasms↗
PubMed1991

Endothelin: localization, synthesis, activity, and receptor types in human penile corpus cavernosum.

The localization, synthesis, and activity of endothelin and the receptor types mediating its effects in penile corpus cavernosum were investigated in whole tissue and in cultured cells derived from this tissue. With immunocytochemistry, utilizing an antiendothelin 1 (ET-1) monoclonal antibody, endothelin-like immunoreactivity was localized intensely in the endothelium and to a lesser degree in the trabecular smooth muscle. Human corpus cavernosum endothelial cells in culture expressed preproendothelin 1 mRNA, as determined by Northern blot analysis. Significant amounts of endothelin-like immunoreactivity were measured by radioimmunoassay in the supernatants of corpus cavernosum endothelial cells in culture. Endothelins are potent constrictors and caused long-lasting contractions of corporeal strips in organ chambers. Equilibrium binding analysis of endothelins to their receptor sites revealed high-affinity, specific, and saturable binding of labeled endothelins to corporeal membranes. Competition binding experiments demonstrated receptors with high affinity for ET-1 and -2 and low affinity for ET-3 and another, less abundant, set of receptors with high affinity for ET-1, -2, and -3. Affinity labeling of endothelins to corporeal membranes, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, revealed that ET-1 and -2 cross-linked specifically to three different molecular mass components (75, 52, and 34 kDa). ET-3 bound only to the 34-kDa component. It is concluded that human corpus cavernosum endothelium has the ability to synthesize and release endothelin, that endothelins contract corporeal smooth muscle, and that at least two distinct endothelin receptors may exist and are differentiated by their affinity for ET-3.

Affinity Labels↗
PubMed1989

Expanded role for fine needle aspiration of the prostate. A study of 335 specimens.

In 279 patients, 335 cytologic samples were obtained from the prostate and correlated with histology obtained by core needle biopsy in 189 cases. Approximately 6% of the cytologic specimens were inadequate for diagnosis. The unconfirmed positive rate for malignancy was 1.6%, the false-negative rate was 27.9%, and the accuracy rate was 89.6%. Granulomatous inflammation was diagnosed in 19 cases, and three cases of tumors other than acinar carcinoma of the prostate were encountered. Based on our experience, cytologic criteria for the diagnosis of prostatic adenocarcinoma are described.

Adenocarcinoma↗
PubMed1989

Fluoroscopically guided retrograde brush biopsy in the diagnosis of transitional cell carcinoma of the upper urinary tract: results in 45 patients.

This is a retrospective review of 45 patients suspected of having transitional cell carcinoma of the upper urinary tract who underwent fluoroscopically guided retrograde brush biopsy at our institution during a recent 3-year period. All patients evaluated had an abnormal IV urogram or retrograde pyelogram in which the diagnosis of transitional cell carcinoma of the kidney or ureter was suspected or could not be excluded. The results of the brush biopsy were compared with the final diagnosis established at surgery or through clinical and surgical follow-up. Results of the biopsies were classified into five categories: (I) normal transitional epithelium (16 patients), (II) atypical cells (eight patients), (III) dysplastic cells (two patients), (IV) suspicious for malignancy (four patients), and (V) conclusive evidence of malignancy (eight patients). In four additional patients, other miscellaneous diagnoses were made, and in three others the procedure was nondiagnostic. Brush biopsies interpreted as Categories III, IV, and V had a positive predictive value of 100% (14/14) for the diagnosis of transitional cell carcinoma, and biopsies showing atypical cells (Category II) had a positive predictive value of 75% (6/8). Tabulating all diagnostic categories except for normal as a positive diagnosis, the procedure had a sensitivity of 91%, a specificity of 88%, and an accuracy of 89%. No significant complications were encountered. This experience suggests that brush biopsy is a valuable technique in patients suspected of having transitional cell carcinoma.

Adult↗