12 research outputs found
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2187: Adenoviral E2F1 and Antisense MDM2 Sensitize Prostate Cancer Cells To Androgen Deprivation and Radiation
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Expression of the matrix metalloproteinase promatrilysin in coculture of prostate carcinoma cell lines
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Adenoviral-E2F1 in Combination with Androgen Deprivation and Radiation Inhibit Prostate Tumor Growth in Nude Mice
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Changes in structure and functions of prostate by long‐term administration of an androgen, testosterone enanthate, in rhesus monkey (Macaca mulatta)
The increasing use of androgens in clinical trials for developing a safe, effective, and reversible male contraceptive has necessitated a critical evaluation of the effects of their long‐term use on the structure and functions of the prostate gland, which is androgen dependent. Combination regimens using progestogens, gonadotropin‐releasing hormone antagonists, or antiandrogens along with androgens are undergoing clinical evaluation as antispermatogenic agents. The majority of these regimens have used testosterone enanthate (TE) as the androgen of choice, but very limited information is available on the side effects of long‐term androgen use. The present study is the first report that critically evaluates the effects of long‐term use of TE on prostate structure and functions.
Adult male rhesus monkeys received intramuscular injections of 50 mg of TE once in 14 days for 33 months. The cranial and caudal lobes of the prostate, which were removed under ketamine anesthesia, were processed for the preparation of semithin sections to evaluate histological changes. The DNA distribution in the cells was studied in single cell suspensions of cranial and caudal lobes of the prostate by using flow cytometry. Changes in the levels of testosterone, estradiol, prostate‐specific acid phosphatase (PAP), and prostate‐specific antigen (PSA) in samples collected during the pretreatment period and at the time of removal of the prostate were estimated by using conventional procedures. Control samples were processed simultaneously. The administration of TE for 33 months caused the following changes: 1) significant increase in the weight of both lobes of the prostate, 2) cellular hypertrophy and increase in secretory material in the cells and in the lumen of the acini in the central and peripheral zones of the two lobes of the prostate, 3) cellular hyperplasia indicated by flow cytometric analysis of DNA content, 4) significant increase in the secretion of PAP and levels of estradiol, and 5) a marked increase in fibromuscular stroma in the central and peripheral zones of both the lobes of the prostate.
The present study is the first report to provide evidence that long‐term androgen treatment has caused hypertrophy of the prostatic epithelial cells, which showed increased secretory activity. The hyperplastic changes indicate a need for the development of new androgens with a better pharmacokinetic profile for use in male contraceptive regimens. Anat. Rec. 252:637–645, 1998. © 1998 Wiley‐Liss, Inc
Vapour phase preparation and characterisation of SiC f-SiC and C f-SiC ceramic matrix composites
Several 2D SiC f-SiC and C f-SiC composites were fabricated using isothermal and isobaric Chemical Vapour Infiltration (ICVI) process. The reinforcements used in the above composites are Nicalon CG fabric and C fabric. Prior to SiC matrix infiltration, BN and C interfaces were applied to the fibre by using the pre-cursors Boron Trichloride (BCl 3)-Ammonia (NH 3) and Methane (CH 4) respectively to improve the mechanical performance of the composites. SiC matrix was infiltrated by the decomposition of Methyl Trichloro Silane-CH 3SiCl 3 (MTS) in the presence of hydrogen at the temperature ranging from 950°C to 980°C. H 2/MTS flow rate ratio used for this study is 16:1.An appropriate temperature for uniform SiC infiltration without any premature pore closures have been obtained by kinetic experiment. Density and porosity of the above composites were measured using the method described by EN1389:2003. Various mechanical characterizations like flexural strength, tensile strength and fracture toughness of the SiC f-SiC composites were also studied. The SiC f-SiC composites were subjected to thermal exposure (1000°C for 100 hr in an oxidizing atmosphere) and tensile strength results obtained before and after thermal exposure were compared. RT Flexural Strength and Fracture Toughness (K IC) of composite-SQAV (SiC f/C/SiC) and composite-SQBII ( SiC f/BN/SiC) are measured by 3-point bending and results were compared. RT Flexural strength of C f-SiC composites with C interface of two thicknesses were measured and compared. X-ray diffraction and micro structure studies have been made to confirm the β-SiC and to see the fibre/matrix interface, uniformity of infiltration, fibre pullout and crack deflections
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Aberrant expression of fibroblast growth factor receptor‐1 in prostate epithelial cells allows induction of promatrilysin expression by fibroblast growth factors
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Promatrilysin expression is induced by fibroblast growth factors in the prostatic carcinoma cell line LNCaP but not in normal primary prostate epithelial cells
CD19-positive acute myeloblastic leukemia with trisomy 21 as a sole acquired karyotypic abnormality
We report that a 63-year-old Chinese female had acute myeloblastic leukemia (AML) in which trisomy 21 (+21) was found as the sole acquired karyotypic abnormality. The blasts were positive for myeloperoxidase, and the immunophenotype was positive for cluster of differentiation 19 (CD19), CD33, CD34, and human leukocyte antigens (HLA)-DR. The chromosomal analysis of bone marrow showed 47,XX,+21[2]/46,XX[18]. Fluorescent in situ hybridization (FISH) showed that three copies of AML1 were situated in separate chromosomes, and that t(8;21) was negative. The patient did not have any features of Down syndrome. A diagnosis of CD19-positive AML-M5 was established with trisomy 21 as a sole acquired karyotypic abnormality. The patient did not respond well to chemotherapy and died three months after the diagnosis. This is the first reported case of CD19-positive AML with trisomy 21 as the sole cytogenetic abnormality. The possible prognostic significance of the finding in AML with +21 as the sole acquired karyotypic abnormality was discussed
Extracellular Matrix and Its Role in Spermatogenesis
In adult mammalian testes, such as rats, Sertoli and germ cells at different stages of their development in the seminiferous epithelium are in close contact with the basement membrane, a modified form of extracellular matrix (ECM). In essence, Sertoli and germ cells in particular spermatogonia are “resting” on the basement membrane at different stages of the seminiferous epithelial cycle, relying on its structural and hormonal supports. Thus, it is not entirely unexpected that ECM plays a significant role in regulating spermatogenesis, particularly spermatogonia and Sertoli cells, and the blood-testis barrier (BTB) constituted by Sertoli cells since these cells are in physical contact with the basement membrane. Additionally, the basement membrane is also in close contact with the underlying collagen network and the myoid cell layers, which together with the lymphatic network, constitute the tunica propria. The seminiferous epithelium and the tunica propria, in turn, constitute the seminiferous tubule, which is the functional unit that produces spermatozoa via its interaction with Leydig cells in the interstitium. In short, the basement membrane and the underlying collagen network that create the acellular zone of the tunica propria may even facilitate cross-talk between the seminiferous epithelium, the myoid cells and cells in the interstitium. Recent studies in the field have illustrated the crucial role of ECM in supporting Sertoli and germ cell function in the seminiferous epithelium, including the BTB dynamics. In this chapter, we summarize some of the latest findings in the field regarding the functional role of ECM in spermatogenesis using the adult rat testis as a model. We also highlight specific areas of research that deserve attention for investigators in the field