Biomedical subjects

B Têtu

Publications and source records attributed to B Têtu.

71 records · Page 4Linked to original sources

PubMed1989

Synthesis of alpha 1-acid glycoprotein by the human prostate.

In order better to define the extent of protein synthesis capacity of the human prostate, we have studied the translation of selected serum proteins using isolated poly(A)+ RNA preparations and the rabbit reticulocyte lysate system. The translation of alpha 1-acid glycoprotein could be conclusively demonstrated but there was no apparent translation of albumin and plasmatic transferrin. Labeled alpha 1-acid glycoprotein was identified by specific immunoprecipitation with a commercial anti alpha 1-acid glycoprotein antiserum and correct processing by canine pancreatic microsomal membranes. Furthermore, we have shown by the immunoperoxidase technique that alpha 1-acid glycoprotein was indeed localized mainly in prostatic epithelial cells in 2 out of 2 patients with benign prostatic hypertrophy and in 3 out of 11 patients with prostatic adenocarcinoma. The significance of the synthesis and secretion of alpha 1-acid glycoprotein by prostatic cell themselves is presently unknown. However, we think that it could represent an interesting subject to explore further in relation with prostatic inflammation.

Cell-Free System↗

PubMed1989

Small cell carcinoma of prostate associated with myasthenic (Eaton-Lambert) syndrome.

A fifty-eight-year-old white man was diagnosed as having an adenocarcinoma of the prostate (grade III by the U.T.M.D. Anderson Hospital grading system). Five years after the initial diagnosis and three months after signs and symptoms of the myasthenic syndrome of Eaton-Lambert (MSEL), he was found to have a small cell carcinoma of the prostate. Histologic examination showed adenocarcinoma merging into a small cell carcinoma component of intermediate cell type. Immunostaining was positive for neuroendocrine markers--namely, neuron-specific enolase and serotonin--and was limited to the small cell carcinoma component. This is the first report of a patient with small cell carcinoma of the prostate presenting with MSEL. Our findings support prior observations of a strong propensity for small cell carcinoma to be associated with paraneoplastic syndromes, regardless of the initial location of the tumor.

Adenocarcinoma↗

PubMed1989

Frequency of alpha-fetoprotein production by Sertoli-Leydig cell tumors of the ovary: an immunohistochemical study of eight cases.

Eight Sertoli-Leydig cell tumors (SLCT) of the ovary were studied by immunostaining for alpha-fetoprotein (AFP). Immunostaining was positive only in cells resembling Leydig cells in three cases and in both Sertoli and Leydig cells in one instance. In one SLCT with positive immunostaining, serum AFP was available and was elevated. Serum level was not measured in the seven other cases. Despite the small number of cases, this study suggests that AFP expression in ovarian SLCT is not unusual. The serum AFP level may, however, depend on the size of the tumor, the proportion of Leydig cells present, and their ability to produce and to release AFP into the bloodstream.

Female↗

PubMed1989

Morphologic prognostic factors of malignant mixed müllerian tumor of the uterus: a clinicopathologic study of 58 cases.

Sixty-one patients with malignant mixed müllerian tumor (MMMT) of the uterus were seen at L'Hôtel-Dieu de Québec between 1950 and 1986, and the histopathologic material was available for review in 58 cases. Of the morphologic parameters studied, the histologic grade of both epithelial and mesenchymal components correlated with the initial stage. Patients with stages I and II disease had a significantly better survival rate than those with stages III and IV (P less than 0.006). Twenty-five patients with a minimum follow-up of two years were initially stage I or II. All six patients of this subgroup with an epithelial component of serous carcinoma type were dead of their disease at 2 yr. Although not statistically significant, tumor necrosis, the mode of tumor invasive (pushing and infiltrative), and the ratio of epithelial to mesenchymal components tended to influence the outcome. The mitotic rate, the type of mesenchymal components, and vascular and myometrial invasion were of no prognostic significance. We conclude that the outcome of patients with uterine MMMT is mainly influenced by the initial stage and the type of epithelial component. The influence of tumor necrosis, the ratio of epithelial to mesenchymal component, and the mode of tumor invasion deserve further studies.

Adult↗

PubMed1988

Blue nevus and melanosis of the prostate. Electron-microscopic and immunohistochemical studies.

Two cases of blue nevus and one case of melanosis of the prostate were studied with ultrastructural and immunohistochemical methods. All patients complained of urinary obstruction, and the clinical impression in all was benign prostatic hyperplasia. Melanin was present in the stroma of the prostate in all cases. In one, pigment was also demonstrated both in benign and malignant epithelial cells. Electron microscopically, melanosomes in different stages were present in the two white patients, but only mature stage IV melanosomes were demonstrated in the black patient. The melanin in epithelial cells consisted only of mature melanosomes. Immunohistochemically, the stromal cells that contained melanin stained with S-100 protein. The evidence suggests that the pigmented cells in the prostatic stroma are melanocytes and the melanin in the glandular epithelium is a result of the transfer of pigment from the stromal melanocytes.

Aged↗

PubMed1988

Atypical spindle cell lesions of the prostate.

This report is a review of the spectrum of prostatic spindle cell lesions that are usually benign, but have morphologic features suggestive of high-grade malignancy. The problem is complicated further by the extreme rarity and heterogeneity of such lesions. Sixteen cases of atypical prostatic spindle cell proliferations are reported, and the differential diagnosis with malignancy is reviewed.

Adult↗

PubMed1988

Renin-producing ovarian tumor. A case report with immunohistochemical and electron-microscopic study.

A 39-year-old woman presented with arterial hypertension. Examination of the patient revealed elevated plasma renin activity, hyperaldosteronemia, hypokalemia, and a pelvic mass. Subsequently, an 11-cm right ovarian tumor mass with histologic features of an unusual stromal cell tumor was resected. Immunohistochemical studies demonstrated renin production by tumor cells. Organelles resembling mature renin granules were identified by electron microscopy. Although blood pressure normalized after the initial surgery, the hypertension resumed with later recurrence of the tumor. We believe the tumor originated from renin-secreting ovarian stromal cells, possibly granulosa cells.

Adult↗

PubMed1987

Small cell carcinoma of the kidney. A clinicopathologic, immunohistochemical, and ultrastructural study.

Three cases of primary small cell carcinoma of the kidney with light microscopic, immunohistochemical, and electron microscopic findings are reported. Two patients died of disseminated disease 8 months and 1 year, respectively, after the diagnosis and the third was free of tumor after 18 months. Immunohistochemical studies revealed keratin immunostaining of tumor cells in two cases and staining for neuron-specific enolase in the third. The third case also showed a few dense neurosecretory granules at the ultrastructural level. Although no strong conclusions regarding histogenesis can be drawn, this study indicates that small cell carcinoma of the kidney exists and does not necessarily exhibit a neuroendocrine differentiation. Small cell carcinoma of the kidney must be considered in the differential diagnosis of malignant renal tumor, especially in cases in which a large necrotic tumor is present. Based on the few cases presented in this study and on the one previously reported case, small cell carcinoma of the kidney appears to be an aggressive tumor.

Aged↗

PubMed1987

Acridine-orange flow cytometry of urinary bladder washings for the detection of transitional cell carcinoma of the bladder. The influence of prior local therapy.

Analysis of cellular DNA and RNA contents of 249 bladder irrigation specimens from 129 patients with a history of transitional cell carcinoma (TCC) of the bladder was performed using acridine-orange flow cytometry (FCM). Washings from patients with prior intravesical chemotherapy or radiation therapy were compared to those from patients with no history of treatment other than tumor resection to evaluate the reliability of FCM for the detection of tumor and the influence of prior local therapy on that reliability. Five FCM patterns were defined on the basis of DNA and RNA indexes in relationship to peripheral blood lymphocytes. FCM results were compared to cytologic findings in 237 cases, cystoscopic findings in 230 cases, and histologic data in 99 cases. Presence of a single diploid stem line was associated with absence of bladder tumor in 71% of cases from patients treated with surgery alone or with radiation therapy, but there was residual tumor in 53% of patients exposed to prior local chemotherapy. An elevated RNA content in a diploid cell population did not provide additional diagnostic information. Presence of an aneuploid stem line was associated with tumor in 85% of cases, regardless of prior therapy. Aneuploidy predicted the appearance of tumor in four of six patients with a negative cystoscopy. Tetraploidy (greater than 10% of total cell population) was associated with tumor in 79% of patients treated with surgery alone, whereas no tumor was found in more than 50% of patients who had undergone prior chemotherapy or radiation therapy. This study stresses the importance of prior treatment history in evaluating the results of DNA-FCM for bladder cancer. It demonstrates the unreliability of FCM diploid and tetraploid cell populations in patients previously treated by local chemotherapy or radiation. However, it also supports prior observations that DNA-aneuploidy and DNA-tetraploidy are useful for detecting and predicting bladder cancer in patients submitted to surgery alone.

Acridine Orange↗

PubMed1987

Small cell carcinoma of the prostate. Part I. A clinicopathologic study of 20 cases.

Clinical information and histological slides of 20 cases of small cell carcinoma of the prostate seen at The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston over a 23-year period were reviewed. Patient's ages ranged from 30 to 89 years (median, 67 years). In nine cases, pure adenocarcinoma of the prostate preceded recognition of the small cell component by 7 months to 8 years (median, 18 months); five of these were initially at Stage A. There was a small cell component at presentation in 11 cases (10, Stage D). Small cell carcinoma was merging with the adenocarcinoma in 11 cases and represented 30% to 90% of total tumor volume. Eleven of 20 patients died of their disease. Those presenting initially with a pure adenocarcinoma survived between 7 months and 9 years (median, 24 months). After the recognition of the small cell carcinoma component, regardless of a prior history of adenocarcinoma, death followed within 1.5 years (median, 5 months). This study suggests a biologic difference in behavior in prostatic carcinoma containing a small cell carcinoma component. The small cell component may manifest early or late in the disease.

Adenocarcinoma↗

PubMed1987

Small cell carcinoma of the prostate. II. Immunohistochemical and electron microscopic studies of 18 cases.

To evaluate the histogenesis of small cell carcinoma of the prostate, 18 cases of this tumor (9 pure small cell and 9 combined adeno- and small cell carcinoma) were studied using immunohistochemical methods. Seven of the small cell components also were assessed by electron microscopic examination. Using neuron-specific enolase (NSE), prostatic acid phosphatase (PAP), and prostate-specific antigen (PSA) on tissue sections, three distinctive immunostaining patterns of small cell carcinoma components were identified: staining positive for NSE and negative for PSA and PAP (10 cases), staining positive for PSA and PAP and negative for NSE (3 cases), and negative reaction for all three antigens (5 cases). Electron microscopic study demonstrated neurosecretory granules in two cases. Based on the immunostaining and electron microscopic findings, small cell carcinomas of the prostate appear to be a heterogeneous group of tumors. Some of them are neuroendocrine carcinomas whereas others are poorly differentiated adenocarcinomas or, possibly, reserve cell carcinomas. Differences in immunostaining patterns or presence and absence of adenocarcinoma component do not reflect any differences in the uniformly poor prognosis of small cell carcinomas, in which median survivals is 7.7 months. The authors believe that, because of such heterogeneity, small cell carcinomas of the prostate arise from multipotential prostatic epithelium and that an origin from specific neuroendocrine cells need not be implicated.

Acid Phosphatase↗

PubMed1987

Flow cytometry of transitional cell carcinoma of the urinary bladder: influence of prior local therapy.

A review of acridine-orange DNA and RNA flow cytometry (FCM) histograms of 249 bladder irrigation specimens from 129 patients with a previous history of transitional cell carcinoma (TCC) reveals that aneuploidy and tetraploidy (greater than 10% of total cell population) are reliable markers to detect the presence of bladder tumor in patients treated by surgical resection of tumor only. Tetraploidy is unreliable when the patient received intravesical chemotherapy or radiation therapy but aneuploidy remains accurate. A comparison of the reliability of FCM compared with cytology indicates an overall lower sensitivity and specificity for FCM (respectively, 52% and 73%) as opposed to cytology (respectively, 62% and 92%). Sensitivity is improved and raised to 77% if FCM and cytology are used in conjunction and reaches 82% in patients treated by surgery only and 88% in those who received radiation therapy. The lowest sensitivity and specificity obtained with FCM are in patients treated by intravesical chemotherapy (respectively, 44% and 58%) and the highest are in those treated by surgery without additional therapy (56% and 83%). This study demonstrates that FCM criteria for diagnosis of TCC of urinary bladder on bladder irrigation specimens depends on patient's treatment history. It also indicates that sensitivity and specificity of cytology to detect bladder tumor are superior to those obtained with FCM but both methods may be considerably improved if they are used in conjunction.

Aneuploidy↗

PubMed1986

Chondrosarcoma with additional mesenchymal component (dedifferentiated chondrosarcoma). I. A clinicopathologic study of 26 cases.

During a 37-year period, 26 patients were seen who had chondrosarcoma with additional mesenchymal components ("dedifferentiated low-grade chondrosarcoma"). Sixteen were men and 10 were women aged 30 to 85 years (median, 61 years). The tumors' chondroid areas were of borderline or low-grade malignancy. The additional mesenchymal component was histologically classified as malignant fibrous histiocytoma (16), rhabdomyosarcoma (4), low-grade fibrosarcoma (3), osteosarcoma (2), and undifferentiated sarcoma (1). Preferred locations were pelvis (10) and femur (8). Symptoms had been present for 1 year or less in most cases. Pain was the most common symptom. In 15 of 26, major amputation was the primary treatment. Twelve patients received chemotherapy, usually after developing metastatic disease, but only one achieved a partial response. Median disease-free interval after diagnosis was 4 months, median survival was 6 months, and 19 patients died within 1 year. Of 4 who survived longer than 18 months, 3 presented with a low-grade fibrosarcoma. Survival and development of metastasis appeared unrelated to cell type, initial treatment, or chemotherapy, except when the tumor's initial nonchondroid component was low-grade fibrosarcoma.

Adult↗

PubMed1986

Chondrosarcoma with additional mesenchymal component (dedifferentiated chondrosarcoma). II. An immunohistochemical and electron microscopic study.

Light microscopic, immunocytochemical and ultrastructural studies were performed on chondrosarcomas which contained a second, noncartilagenous mesenchymal component. Attention was focused on the nonchondroid portion of each tumor in an attempt to elucidate the histogenesis of this mixed variant of chondrosarcoma. The immunoreactivity of 20 tumors was studied using antisera for S-100 protein, alpha-1-antitrypsin, alpha-1-antichymotrypsin, smooth muscle myosin, desmin, and myoglobin. Cells of the nonchondroid portion stained for alpha-1-antichymotrypsin in 12 of 20 cases, and these were predominantly tumors that had been classified as fibrosarcoma or malignant fibrous histiocytoma by conventional light microscopic study. Staining for S-100 protein was consistently negative, whereas the chondrosarcoma component stained in 14 cases. Six tumors stained for desmin, and four of the six were positive for myoglobin and two for smooth muscle myosin; in four, a rhabdomyosarcomatous component was identified in the hematoxylin and eosin-stained sections. Electron microscopic study was performed on ten tumors and there was a good correlation between the immunohistochemical and ultrastructural findings. Three of the ten were pure rhabdomyosarcomas while the others displayed a range of ultrastructural appearances that can be seen in fibrosarcomas and malignant fibrous histiocytomas. The findings from this study support the view that the tumors are formed by the synchronous differentiation of two separate clones of cells.

Adult↗

PubMed1986

Comparison of monoclonal and polyclonal antibodies directed against immunoglobulin light and heavy chains in non-Hodgkin's lymphoma.

A study comparing the usage of monoclonal and polyclonal antibodies specific for immunoglobulin light and heavy chains was performed on frozen-tissue sections of 30 B-cell non-Hodgkin's lymphomas. In 16 cases, monotypic staining for an immunoglobulin light chain was demonstrated with monoclonal antibodies using a three-step avidin-biotin peroxidase complex (ABC) method; 13 cases were positive for kappa. In 14 cases, no immunoglobulin light-chain production was demonstrated. Repeat staining of 11 of these 14 cases with polyclonal anti-sera by a direct immunoperoxidase method demonstrated monotypic staining for light chain in 10 cases, 9 of which were positive for lambda. In 22 of 30 non-Hodgkin's lymphomas, an immunoglobulin heavy chain was identified using monoclonal anti-sera. In eight cases, however, no heavy chain was found. Repeated staining with polyclonal sera of additional sections in three of eight cases demonstrated heavy-chain production in each case. Decreased sensitivity, especially for the detection of the lambda light chain, rendered this particular lot of monoclonal antibodies unsuitable for immunophenotyping non-Hodgkin's lymphomas. Variability of antigenic sites on the immunoglobulin molecule seems a likely explanation for these observations.

Antibodies, Monoclonal↗

PubMed1979

Effects of noradrenaline and nicotinic acid on plasma free fatty acids and oxygen consumption in cold-adapted rats.

A 3-h noradrenaline (NA) infusion (1.5 microgram kg-1 min-1) produced a sustained enhanced oxygen consumption (O2 cons.) in cold-adapted rats. Plasma free fatty acid (FFA) levels were elevated by NA in control and in cold-adapted rats, but to lesser extent in cold-adapted rats; the increase was maintained at a plateau in both groups during the entire period of NA infusion. A 1-h nicotinic acid (Nic A) infusion (1.5 mg kg-1 min-1) added to the NA infusion inhibited the calorigenic response to NA in cold-adapted rats and reduced the elevated plasma FFA concentration in control and in cold-adapted rats to values below basal levels. However, when the Nic A infusion was stopped, the O2 cons. was increased again in cold-adapted rats by the uninterrupted NA infusion, without the simultaneous increase of the plasma FFA concentration; the plasma FFA concentration was maintained in cold-adapted rats below basal values and merely brought back to basal levels in control rats. From these results, it is suggested that plasma FFA are not an essential substrate to the calorigenic response to NA observed in cold-adapted rats, as 85% of the response can occur when the plasma FFA concentration is very low.

Adaptation, Physiological↗

PubMedDate not supplied

Production of bioengineered cancer tissue constructs in vitro: epithelium-mesenchyme heterotypic interactions.

A few models have been established to study cancer cells in vitro. However, the cellular interactions have rarely been studied specifically using bioengineered cancer constructs combining human carcinoma cells and tumor-associated fibroblasts. We developed an in vitro model of tridimensional bioengineered cancer tissue constructs (bCTC) by seeding mammary epithelial cancer cells or normal keratinocytes over a mesenchymal layer containing tumor-derived fibroblastic cells or normal skin fibroblasts. After the introduction of epithelial cells, each construct was cultured for another 10 d. Histologic analyses showed that carcinoma cell lines could invade the subjacent mesenchymal layer and that the capacity to migrate was related to the invasive potential of cancer cells and the type of fibroblasts used, while noninvasive populations did not. Of the tested epithelial cells, MDA-MB-231 and, to a lesser degree, HDQ-P1 cell lines were invasive, and the invasion was deeper into the mesenchymal component containing tumor-derived fibroblasts. However, with normal skin fibroblasts, the mesenchymal layer was degraded twice faster than with tumor-derived fibroblastic cells. MDA-MB-231 cells and normal keratinocytes induced the highest level of gelatinase B, and the level was lowest with the MCF-7 cell line. The activated form of gelatinase B was, however, induced to the highest levels in the keratinocyte-seeded bCTC containing tumor-derived but not normal fibroblasts. MDA-MB-231 was the only epithelial cancer cell line whose activity of gelatinase A was reduced when cocultured with tumor-derived fibroblasts but not under normal fibroblast stimulation. Finally, a 50/48-kDa gelatinase band has been observed in bCTCs with noninvasive epithelial cells only. Our study demonstrates the selective secretion of gelatinases according to the phenotype of the cells seeded in the various bCTCs.

Breast↗