Replacement of the urinary bladder.
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Biomedical subjects
Publications and source records attributed to D E Neal.
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1. The importance of Ca2+ release from the sarcoplasmic reticulum (SR) in excitation contraction (EC) coupling in human detrusor muscle remains controversial. In this paper the contribution of Ca2+ release to agonist induced contraction is assessed. 2. Dose response curves to carbachol (0.01 - 10 microM) were constructed before and after exposure to 200 nM Thapsigargin (Tg). Tg pre-treatment reduced the force of contraction at all agonist concentrations however, the reduction was dose dependent. At 0.1 microM the contractions were reduced to 14.5 +/- 7% (mean +/- s.e.mean) of controls (n = 8) while at 10 microM the contractions were only reduced to 92 +/- 3% of controls (n = 10). 3. The role of external Ca2+ was examined by measuring the magnitude of contraction to low and high doses of agonist in the presence and absence of external Ca2+. With (0.1-0.3 microM) carbachol the contractions in nominally Ca2+ free media were 4+/-4% of controls (n = 7) whilst with (1 - 10 microM) carbachol the contractions were 36 +/- 8% of controls (n=7) suggesting that at low agonist concentrations the release of Ca2+ has a requirement for external Ca2+. 4. Pre-treatment of muscle strips with the Ca2+ channel blocking agent diltiazem reduced the contractile responses to carbachol. Contractions induced by 0.1 microM were reduced to 29+/-11% (P<0.05) of controls while those activated by 10 microM were reduced to 86+/-6% (P= 0.1) of controls (n = 4) suggesting the Ca2+ influx needed to activate internal store release at low agonist stimulation is through L-type Ca2+ channels. 5. These observations confirm the importance of thapsigargin sensitive intracellular Ca2+ store release in the activation of contraction of detrusor smooth muscle and suggest the overall contribution of this store depends upon the magnitude of the agonist stimulation.
Transitional cell carcinomas (TCC) of the urinary bladder are known to express proteins which can yield potentially immunogenic peptide epitopes for expression in the context of cell surface class I or class II MHC antigens. However, additional costimulatory ligands must also be expressed before such a cell might directly induce full activation and proliferation of resting, antigen-specific T lymphocytes. Intravesical therapy might be used to manipulate T cell costimulation in order to promote specific rejection of TCC cells. This in vitro study examined the potential of such a strategy by transfection of the prototypical TCC line J82 with the important costimulatory molecules CD80 (B7-1) and CD86 (B7-2). Untransfected J82 cells expressed class I and II MHC antigens, a range of cell adhesion molecules, though did not induce T cell proliferation in a robust, allogeneic co-culture system. Transfected J82 cells expressed CD80 or CD86 at levels comparable to an antigen-presenting B cell line. Furthermore, functional surface expression of CD80 and CD86 was demonstrated in a mitogen-dependent assay of costimulation. However, neither CD80+ nor CD86+ transfectant J82 cells could induce significant proliferation of antigen-specific CD4+ T cells. Further analysis showed that bystander J82 cells could inhibit independent T cell activation in an effect dependent on direct cell contact. This inhibitory effect was associated with increased cell death in the responding lymphocyte population and is concordant with surface expression of CD95L by the J82 cell line.
The role of intracellular Ca2+ release in the activation of human bladder smooth muscle is controversial. We have measured the expression of mRNA encoding for the ryanodine receptor (RyR) isoforms (RyR1, RyR2 and RyR3) in isolated human detrusor smooth muscle. mRNA for RyR2 was detected in all samples but no mRNA for RyR1 or RyR3 could be found. Human bladder smooth muscle cells in culture are unresponsive to caffeine, suggesting the absence of a functional RyR system. However, mRNA encoding for RyR2 was detected in these cells. Using saponin-permeabilized cells, a Ruthenium Red-sensitive Ca(2+)-dependent 45Ca2+ release could be demonstrated from the sarcoplasmic reticulum (SR). These data confirm the functional presence of Ca(2+)-induced Ca2+ release (CICR) in cells and suggest that the properties of the RyR2 isoform in human detrusor may change when the cells are maintained in culture. The implications of these observations to detrusor smooth muscle function are discussed.
Transforming growth factor-beta1 (TGFbeta1) is inhibitory to most epithelia, but its role in the control of proliferation of prostatic epithelium is unclear. In some cells, TGFbeta1 inhibition is achieved by up-regulation of cyclin-dependent kinase (cdk) inhibitors including p15, p21 and p27. Our aims were to determine whether the effects of TGFbeta1 on human prostatic epithelial cell cycle kinetics were mediated by alterations in the levels of the cdk inhibitors p15, p16, p21 and p27 and hypo-phosphorylated retinoblastoma protein (Rb). Human prostatic epithelial cells in primary culture were grown in the presence of TGFbeta1 (0-10 ng/ml) for up to 4 days and proliferation assessed using a [3H]thymidine uptake assay. Levels of p15, p16, p21 and p27 were measured at both mRNA and protein level by means of a reverse transcriptase PCR-based assay and Western analysis. Rb and cdk2 levels were measured. Exogenous TGFbeta1 (0-5 ng/ml) inhibited proliferation. This was associated with blocking of the cell cycle at G1, and up to 4-fold increases in p15, p21 and p27 mRNA levels, but no change was observed in p16 mRNA levels; these changes were not blocked by cycloheximide. Increased levels of p15, p21 and p27 protein were also accompanied by increased levels of hypo-phosphorylated Rb and decreased cdk2 kinase activity. TGFbeta1 has mainly inhibitory effects on benign human prostatic epithelium, which are caused by up-regulation of cdk inhibitors, hypo-phosphorylation of Rb and delaying of the cell cycle in G1.
OBJECTIVE: HIV-positive individuals commonly have symptoms of airway disease. We evaluated thin-section CT scans of HIV-infected individuals during inspiration and expiration for evidence of focal air trapping. We also correlated imaging findings with pulmonary function test results. SUBJECTS AND METHODS: Fifty-nine subjects, 48 of whom were HIV-positive and 11 of whom were HIV-negative, underwent thin-section CT of the thorax during inspiration and expiration. All subjects also underwent pulmonary function tests. Two radiologists, who were unaware of the subjects' HIV status and smoking history and of the results of pulmonary function tests, evaluated the CT scans for the presence and severity of focal air trapping. RESULTS: Expiratory CT revealed focal air trapping in 33 subjects: 30 were HIV-positive and three were HIV-negative (p = .0338). The mean values of forced expiratory volume in 1 sec (FEV1), forced mid expiratory flow, and diffusion capacity (DL(CO)) were significantly lower for subjects with focal air trapping (mean = 88.85, 84.52, and 80.80, respectively) than for those with normal findings on CT (mean = 100.84, 99.24, and 95.82, respectively; p = .001, p = .021, and p = .003, respectively). We found no significant differences in smoking history between HIV-positive and HIV-negative subjects. Severe air trapping on expiratory CT scans was seen in three subjects: All three had HIV infection, low CD4 counts, and abnormally decreased FEV1 and DL(CO) values. CONCLUSION: Focal air trapping was a common finding on thoracic CT scans obtained during expiration in HIV-positive subjects. In addition, focal air trapping was associated with significantly lower FEV1, forced mid expiratory flow, and DL(CO) values than those found for subjects in whom CT revealed no focal air trapping. These results suggest that small airways disease may accompany a decline in pulmonary function in HIV-positive individuals.
PURPOSE: The aim of this study was to investigate stretch activated channels in human detrusor using hypo-osmolar solutions to produce cell deformation. Stretch activated channels could provide another mechanism by which detrusor myocytes may be coupled. MATERIALS AND METHODS: Human detrusor removed at surgery was dissected into strips and also enzymatically digested and cultured. Strips (5x1x1 mm.) were mounted in an organ bath and perfused with gassed Tyrode's. Hypo-osmolar solutions were made by removal of NaCl. Gadolinium (Gd3+), a blocker of stretch activated channels (SACs), and diltiazem, an L-type Ca2+ channel antagonist were used at 10 microM concentrations. Mean data +/- S.E.M. are expressed as a percentage of maximal tension produced by 1 microM carbachol for each patient. Enzymatically disaggregated, human detrusor was cultured in flasks, passaged and placed on glass coverslips. Once confluent the cells were incubated with the Ca2+ sensitive fluorochrome Fura-2AM. Coverslips were placed in a bath on the stage of EPI-fluorescence microscope and solutions were perfused through the bath (5 ml. per minute, 35C, pH 7.4). Changes in fluorescence emission ratio (proportional to changes in cytosolic Ca2+) were measured. RESULTS: Hypo-osmolar solutions produced a tension increase in the strips and a Ca2+ influx in the cells. In the strips in paired experiments Gd3+ and diltiazem significantly reduced the response to hypo-osmolar solution (87%+/-16% v. 51%+/-12.5%, p = 0.003, n = 10 for Gd3+), and (69%+/-11% v. 37%+/-9%, p = 0.001, n = 9 for diltiazem). In Ca2+ free solution responses were significantly reduced (65%+/-10% v. 21%+/-8%, p = 0.001, n = 9). In the cells in paired experiments, 10 microM Gd3+ significantly reduced the elevation of cytosolic Ca2+ in response to hypo-osmolar solutions (median 0 v. 0.38 (62 cells, n = 7 bladders)), as did Ca2+ free hypo-osmolar solution (median 0 v. 0.44 (46 cells, n = 7)). 10 microM diltiazem (L-type Ca2+ channel antagonist) did not influence the response to hypo-osmolar solution (p = 0.14, median 0.5 v. 0.54 (31 cells, n = 4)). CONCLUSIONS: Hypo-osmolar solutions produced a tension increase in human detrusor that appears to be dependent on upon influx of Ca2+ through stretch activated channels (SACs), influx of Ca2+ through L-type Ca2+ channels and also on release of intracellular Ca2+.
To examine retrospectively the prognostic significance of TP53 immunoreactivity for both tumor response and patient survival in 83 patients with nonmetastatic muscle-invasive bladder cancer treated with a single transurethral resection (TUR) of tumor and combined cisplatin-based systemic chemotherapy followed by repeat TUR, paraffin-embedded sections of a bladder tumor obtained at TUR before chemotherapy (1 T2, 52 T3, and 30 T4) were immunostained for TP53 using monoclonal PAb1801 and DO-7 antibodies. For the entire cohort, TP53 immunopositivity (PAb1801 or DO-7) did not predict complete response (CR), complete or partial response (PR), progressive disease, or time to death from bladder cancer. There was a highly significant correlation between PAb1801 and DO-7 nuclear immunoreactivity (r = 0.8242; P<0.0001). In 76 patients in which complete clinical data were available, tumor stage (T2/T3; P = 0.0499), CR and PR (P = 0.0016) and CR (P<0.0001) were associated with patient survival. In a multivariate model, CR (P<0.0001) was the only independent predictor of improved survival. In complete responders, neither TP53 immunostaining nor clinicopathological factors stratified patients into prognostic groups. However, in the subset of patients (n = 38) who were chemoresistant (PR or progressive disease), improved survival was associated with > or =20% TP53 immunoreactivity (PAb1801; P = 0.0191) and tumor stage (T2/T3; P = 0.0358). TP53 immunopositivity (PAb1801 or DO-7) did not predict overall survival or response to systemic chemotherapy in patients with nonmetastatic but predominantly clinical stage > or =T3 bladder cancer, but it had prognostic significance within the chemoresistant subgroup.
BACKGROUND: Apoptosis-regulating genes have been shown to be important in the biology of prostate cancer. The aim of this study was to examine and correlate the expression of the apoptosis-regulating genes bcl-2, bax, and p53 with the frequency of apoptosis and rate of proliferation in benign prostatic epithelium (BP), prostate cancer, and high-grade prostatic intraepithelial neoplasia (HGPIN), which is currently considered the most likely precursor of prostate cancer. METHODS: Forty-four patients with histologically proven prostate cancer were investigated. All the men underwent radical prostatectomy. Immunohistochemistry was performed to assess expression of bcl-2, bax, and p53, and proliferation rate, as measured by the Ki-67 index. The frequency of apoptotic bodies was assessed by morphological criteria. RESULTS: The apoptotic index (AI) was highest in prostate cancer, and was significantly greater in HGPIN compared to benign prostate. The Ki-67 index was greatest in cancer, intermediate in HGPIN, and lowest in BP. The AI was increased in areas of BP in patients treated with neoadjuvant androgen ablation. No change in AI was seen in treated cases of HGPIN or cancer. Accumulation of p53 protein was infrequent in prostate cancer (2/43: 4.6%), and was absent in HGPIN. Bcl-2 overexpression was present in 2.3% of cancers (1/43) and in 34.9% of cases of HGPIN (15/43). Bax expression was seen in all cases of cancer and HGPIN. There was no correlation between bcl-2 expression and the apoptotic and Ki-67 indices in HGPIN. CONCLUSIONS: p53 and bcl-2 expression is infrequent in clinically organ confined prostate cancer. Bcl-2 expression is significantly higher in HGPIN than in both the associated prostate cancer and BP. The AI and Ki-67 index appeared intermediate in the putative precursor lesion HGPIN compared to prostate cancer and BP.
BACKGROUND: Human prostatic epithelium consists mainly of basal and secretory luminal cells: the origin of these phenotypes from a common stem cell, within the basal compartment, has been proposed but not yet demonstrated. METHODS: Analyses by light and electron microscopy, immunocytochemistry, and flow cytometry were used to determine lineage. The criteria for identifying the different phenotypes were characteristic morphology, and organization and expression of luminal- and basal-specific markers. RESULTS: After organoids attached, outgrowths appeared with cells maintaining close cell-to-cell associations. The dividing cell compartment contained a subpopulation of cells with stem-cell characteristics and a major population that may correspond to amplifying cells. The characteristics of the stem-cell phenotype included reactivity with antibodies CKbasal, CK14, and Ki67. The amplifying cells were characterized as an intermediate phenotype between basal and luminal, as reactivity was demonstrated with CKbasal, CK14, and CK18. As outgrowths eventually merged, multilayering was apparent and cells on the uppermost layer had numerous secretory vacuoles and reacted strongly with antibodies CK18 and CK19, androgen receptor, and prostate-specific antigen, which is characteristic of secretory luminal cells in vivo. In passaged cultures, loss of reactivity with CKbasal was detected; we postulate that this population contains the stem-cell fraction. CONCLUSIONS: These findings demonstrate that basal and luminal cells are of the same lineage and are derived from a common stem cell. Moreover, the progenitor stem cells reside within the basal compartment.
BACKGROUND: Delta-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) is currently being investigated for the treatment of prostate diseases. In this study, we evaluate 1) the in vitro production of protoporphyrin IX (PPIX) (the active photosensitizing agent of ALA-mediated PDT) by two different prostate cancer cell lines (LNCaP and PC-3) and a benign, modified, prostatic cell line (TP-2), and 2) the extent of PDT-induced cell injury, as determined by electron microscopy (EM) and cell survival. METHODS: The cell lines were assigned into four treatment groups: group 1, control, no ALA and no light irradiation; group 2, dark control, ALA only; group 3, light control, radiation only; and group 4, PDT, ALA followed by irradiation (630 nm, 3 joules/cm2). The experiments were performed in triplicate. ALA concentration was 50 microg/ml of media in all instances. RESULTS: Following incubation with ALA, PPIX production was significantly increased in the three cell lines studied, and more notably in the PC-3 cell line. Compared to controls, EM and cell survival studies demonstrated significant mitochondrial damage and decreased survival, respectively, in the cells treated with PDT. This was also more evident in the PC-3 cell line. CONCLUSIONS: Our results demonstrate that prostate cells differ in their response to ALA-mediated PDT. This response appears to depend on the intracellular production of PPIX and the cell type, i.e., on the functional and structural characteristics of the cell mitochondria. In addition, our results suggest that PDT might be effective at killing prostate cancer cells.
Androgens are essential for normal prostate physiology and are intimately associated with the growth and progression of prostate cancer. However, few androgen regulated genes in the prostate have been identified. Using the mRNA differential display technique a 164-bp cDNA fragment was identified as being androgen regulated in the human prostate. Nucleotide sequence analysis of this fragment revealed 84% homology with the gene encoding the cytoskeletal protein talin. Confirmation of the androgen regulation of this gene was carried out using Northern analysis. Primary prostatic stromal cells treated with conditioned medium (CM) from androgen-treated primary prostatic epithelial cells showed an approximate 2-fold reduction in talin mRNA levels compared with stromal cells treated with CM from epithelial cells not exposed to androgens. Expression of talin mRNA in human prostatic tissue was confirmed by in situ hybridisation. The highest levels of expression were present in the epithelial cells, with lower levels of expression in the stroma. Thus, androgen regulation of talin expression may play a role in normal and/or aberrant growth and development of the prostate.
The recently identified epidermal growth factor-related peptide cripto-1 has been previously implicated in the development of the malignant phenotype. The identification of gene products that can act as prognostic markers in bladder cancer would be value in determining the management of this heterogeneous group of patients. This study examines cripto-1 expression in benign and malignant bladder using immunohistochemical techniques. The expression of cripto-1 protein in benign and malignant bladder was examined in 45 bladder tumours (Ta/T1 n = 26, T2 n = 5, T3/T4 n = 14) and six benign controls. All 45 tumours showed positive cytoplasmic staining for cripto-1, including areas of carcinoma in situ. None of the six benign controls showed any evidence of positive cripto-1 staining. Twenty-three (60 per cent) bladder tumours had areas of papillary tumour that showed strong positive staining for cripto-1 as opposed to six (29 per cent) sections of histologically normal urothelium adjacent to tumour (P < 0.05). There was no association between cripto-1 staining and tumour grade, stage, or clinical outcome. Cripto-1 protein appears to be specifically expressed in malignant and benign adjacent urothelium of patients with bladder cancer. Its clinical significance, however, remains to be determined.
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We have used microdissection of paraffin-embedded histological sections and polymerase chain reaction (PCR)-based direct DNA sequencing for 54 transitional cell carcinoma (TCC) of the bladder, to examine critically the association between TP53 nuclear accumulation determined by immunohistochemistry and the presence of TP53 mutations, and to examine their relationship to tumour stage and grade, as well as patient survival. There was a significant association between the presence of TP53-positive nuclei (> 10%) and a higher histological stage and grade (P = 0.0115, P = 0.0151 respectively; Fisher's exact). A significant association between TP53 gene mutations and TP53 nuclear reactivity in more than 10% of tumour cell nuclei was also observed (P = 0.0003; Fisher's exact). Mutations were detected in 18/54 (33%) cases together with the wild-type sequence when analysed from bulk frozen samples, with significant clustering of mutations in exons 7 and 8. The microdissection method distinguished more clearly between heterozygous and/or homozygous alterations of the TP53 tumour-suppressor gene, and clearly showed frequent accumulation of TP53 in the absence of mutations. When microdissecting immunonegative regions from the same paraffin sections, three out of ten samples showed the identical mutations detected in the immunopositive regions. There was a significant association between TP53 immunoreactivity in more than 50% of tumour cell nuclei and decreased survival among all patients (P = 0.0325; log-rank test). The patients with TP53 mutations showed a trend for a shorter survival period; however, the association was not statistically significant at the 95% confidence level (P = 0.132; log-rank test). In conclusion, our observations show that accumulation of TP53 occurs frequently in the absence of mutations, and that such accumulation is nevertheless associated with poor survival when it occurs in a high proportion (> 50%) of tumour cell nuclei.
Prostate cancer is the second most common malignancy in men in the UK. The disease is unpredictable in its behaviour and, at present, no single investigative method allows clinicians to differentiate between tumours that will progress and those that will remain quiescent. There is an increasing need for novel means to predict prognosis and outcome of the disease. The aim of this study was to assess the value of artificial neural networks in predicting outcome in prostate cancer in comparison with statistical methods, using a combination of conventional and experimental biological markers. Forty-one patients with different stages and grades of prostate cancer undergoing a variety of treatments were analysed. Artificial neural networks were used as follows: eight input neurons consisting of six conventional factors (age, stage, bone scan findings, grade, serum PSA, treatment) and two experimental markers (immunostaining for bcl-2 and p53, which are both apoptosis-regulating genes). Twenty-one patients were used for training and 20 for testing. A total of 80% of the patients were correctly classified regarding outcome using the combination of factors. When both bcl-2 and p53 immunoreactivity were excluded from the analysis, correct prediction of the outcome was achieved in only 60% of the patients (P = 0.0032). This study was able to demonstrate the value of artificial neural networks in the analysis of prognostic markers in prostate cancer. In addition, the potential for using this technology to evaluate novel markers is highlighted. Further large-scale analyses are required to incorporate this methodology into routine clinical practice.
Prostatic adenocarcinoma commonly metastasizes to bone. Unlike most other bony secondaries, the majority of skeletal prostatic metastases are osteoblastic rather than osteolytic in nature. Several growth factors which are known to stimulate bone formation are expressed in benign and malignant prostate cells, but none has been specifically linked to osteosclerotic metastases. Bone morphogenetic proteins (BMPs) induce ectopic bone formation in vivo. We have reported previously that BMP-6 mRNA and protein are expressed in the majority of primary prostatic carcinomas with established skeletal metastases but rarely in clinically organ-confined tumours. This study examines the expression of BMP-6 mRNA in matched prostatic primary and secondary bony lesions and in isolated skeletal metastases from prostatic adenocarcinomas, as well as other common human malignancies, by in situ hybridization. BMP-6 mRNA was detected in 11 out of 13 bone metastases from prostate carcinoma and in three paired samples of primary prostate carcinoma and matching skeletal metastasis. Weak signals for BMP-6 were also present in 5 out of 17 skeletal deposits from non-prostatic malignancies. BMP-6 mRNA appears to be strongly expressed in prostatic adenocarcinomas, both in the primary tumour and in bone metastases. It is also expressed, though less frequently, in skeletal metastases from other human carcinomas. Our findings suggest that BMP-6 may hold potential as an attractive marker and possible mediator of skeletal metastases, particularly in prostate carcinoma.