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Biomedical subjects

P D Abel

Publications and source records attributed to P D Abel.

At least 19 recordsLinked to original sources
PubMed1999

Differentially expressed genes in hormone refractory prostate cancer: association with chromosomal regions involved with genetic aberrations.

Differential gene expression between the androgen sensitive human prostate cancer cell line LNCaP and an insensitive clonal variant, LNCaP-r, was demonstrated by suppression subtractive hybridization. Twenty-one sequences were identified of which 9 are homologous to known genes, 11 are represented by expressed sequence tags (ESTs), and 1 is novel. We present data for 5 of 7 sequences confirmed to be differentially expressed by Northern blot analysis and semiquantitative RT-PCR. Only one gene, fibronectin (FN), was highly overexpressed (>60-fold) in LNCaP-r cells, consistent with previously reported overexpression of FN in prostate cancer. Four sequences were down-regulated in LNCaP-r cells, including an inactive variant of the E2 ubiquitin conjugating enzyme (UEV-1), a novel metalloproteinase-related collagenase (PM5), and a potential tumor suppressor gene (breast basic conserved gene, BBC1). UEV-1 is multifunctional, regulates the cell cycle via cdk1, has homology to MMS2 and likewise functions as a DNA protection protein, and also has homology to TSG101. Aberrant splice variants of TSG101 occur frequently in both breast and prostate cancer, but its mechanism of action is unknown. FN, BBC1, and UEV-1 localize to regions of chromosomal aberration (2q3.4, 16q24.3, and 20q13.2, respectively) associated with advanced prostate cancer and thus may be highly relevant to disease progression.

Androgen Antagonists↗
PubMed1999

Development of the fertility adjustment scale.

OBJECTIVE: To develop a standardized measure of psychological adjustment to infertility. DESIGN: A cross-sectional two-group comparison study. SETTING: Two specialized fertility clinics in large teaching hospitals. PATIENT(S): Fifty men and 50 women undergoing evaluation and/or treatment of fertility problems. INTERVENTION(S): The Fertility Adjustment Scale was administered with the Hospital Anxiety and Depression Scale as a measure of concurrent validity. MAIN OUTCOME MEASURE(S): Scores on the Fertility Adjustment Scale and the Hospital Anxiety and Depression Scale. RESULT(S): Scores on the Fertility Adjustment Scale were distributed normally. Split-half and internal consistency were high. A significant correlation with measures of mood, anxiety, and distress provided evidence of concurrent validity. CONCLUSION(S): Preliminary results suggest that this measure will be a useful tool in assessing psychological reactions to fertility problems and outcomes of treatment.

Adaptation, Psychological↗
PubMed1999

Role of the Bcl-2 gene family in prostate cancer progression and its implications for therapeutic intervention.

Prostate cancer (PC) is an escalating health burden in the western world. A large number of patients still present with extraprostatic (i.e., T3/T4, N0, M0/M1 or any T category and M1 disease or involved lymph nodes) and therefore incurable disease. Since the work of Huggins in 1940, there have been no major therapeutic advances and androgen ablation remains the best treatment option for extraprostatic androgen-responsive PC. Eighty to ninety percent of PC patients respond well to this form of treatment initially. After a median time of approximately 2 years, however, relapse to an androgen-independent (AI) state occurs, followed by death after a further median 6 months. Androgen ablation is rarely curative. The major molecular defect in extraprostatic and AI PC is the inability of PC cells to initiate apoptosis in response to a variety of stimuli, including different forms of androgen ablation and cytotoxic agents. The balance between cellular proliferation and cell death is regulated by multiple genes or families of genes through the cell cycle. The exact mechanisms governing this intricate and complex process are as yet not fully understood. One family of genes involved in cell survival/death control is the Bcl-2 gene family, which consists of homologous proteins that function to regulate distal and crucial commitment steps of the apoptotic pathway. The Bcl-2 family constitutes both agonists and antagonists of apoptosis that function at least in part through protein-protein interactions between various members of the family. The final outcome depends on the relative ratio of death agonists and antagonists. Bcl-2 expression has been closely associated with the AI phenotype of PC. Cytotoxic chemotherapy may be used as palliative therapy in AI PC but has not been found effective. Most chemotherapeutic cytotoxic agents induce apoptosis in cancer cells by direct and indirect action on the cell cycle. In vitro and in vivo studies have established that Bcl-2 expression confers an antiapoptotic activity against androgen withdrawal and cytotoxic chemotherapy. It thus offers a tempting potential target for therapeutic manipulations of PC.

Apoptosis↗
PubMed1998

What determines the choice of procedure in stress incontinence surgery? The use of multilevel modeling.

The purpose of this study was to identify the determinants of choice of surgical procedure (anterior colporrhaphy, colposuspension, or needle suspension) to treat stress incontinence in women. We used multilevel modeling of data on 271 patients in 18 hospitals in England in 1993-94. Patient-related factors included sociodemographic details, anatomical diagnosis, symptom severity, symptom impact, previous treatment, parity, comorbidity, and general health status. Surgeon-related factors were specialty, grade, and annual volume of procedures undertaken. Hospital teaching status was considered. Some patient-related factors were associated with choice of procedure: women with a concomitant genital prolapse, with a history of high parity, and with no previous nonsurgical treatment were more likely to undergo an anterior colporrhaphy than a colposuspension or needle suspension (although this finding could be confounded by surgical specialty). In addition, women were more likely to be treated by colposuspension if their surgeon specialized in incontinence surgery (measured by annual volume of cases). Finally, being treated by needle suspension depended on there being a consultant surgeon familiar with the procedure at the hospital attended. While choice of surgical procedure depends partly on the patient's anatomical diagnosis, it is also dependent on the specialty of the surgeon whom she consults and the hospital that she attends. This variability, in turn, could have implications for the patient (as the relative effectiveness of the different procedures is unknown) and for the purchasers of care (as the relative cost-effectiveness of procedures is also unknown).

Adult↗
PubMed1998

Impact of surgery for stress incontinence on the social lives of women.

OBJECTIVE: To assess the feasibility of collecting disease-specific and generic data on the impact of surgery on the social lives of women with stress incontinence; to describe the social impact of surgery in a representative group; and to determine the effect of timing on the assessment of outcome. DESIGN: Longitudinal study; questionnaires before and three, six, and twelve months after surgery. SETTING: Eighteen hospitals in North Thames region. PARTICIPANTS: Four hundred and forty-two women undergoing surgery for stress incontinence between January 1993 and June 1994. MAIN OUTCOME MEASURES: Post-operative recovery time, stress incontinence symptom impact index, activities of daily living, and cost of protection. RESULTS: Post-operative recovery was uneventful for most women, but three months after surgery 24% of those in paid employment beforehand were still on sick or unpaid leave. Most women (75%) reported that stress incontinence had less adverse impact on their lives three months after surgery, though 18% reported no change, and 7% felt life was worse. The likelihood of improvement was similar regardless of whether pre-operative urodynamic studies had been conducted. The extent of improvement was dependent on pre-operative severity. Similar findings were obtained six and twelve months after surgery. After an initial slight but nonsignificant deterioration in their ability to carry out activities of daily living, women gained a slight benefit from surgery (proportion with no or only slight limitation rose from 72% to 82%; P=0.0001). The mean cost of protection (pads and towels) fell from 8.59 pound sterling a month before surgery to 2.99 pound sterling a month one year after surgery, by which time 68% of women were not using protection. In contrast, 11% were still spending over 10 pound sterling a month. CONCLUSIONS: It is possible to collect standard data on the impact of surgery on social functioning and, thus, provide women with better information on likely outcomes. The benefits of pre-operative urodynamic investigations need to be assessed. The stability of the outcome measures over the first post-operative year suggest that outcomes need to be assessed only once and at any time from three to twelve months after the operation.

Activities of Daily Living↗
PubMed1997

Ion channels.

Explore the source record for details and available documents.

Adenosine Triphosphate↗
PubMed1997

Molecular and cellular biology of prostate cancer.

Prostate cancer is an enigmatic disease. Although prostatic-intraepithelial neoplasia appears as early as the third decade and as many as 80% of 80 year old men have epithelial cells in their prostate that fit the morphological criteria for cancer, only about 10% of men will ever have the clinical disease and less than 3% will die from it. There have been no significant proven interventions which have altered the natural history of the disease since hormone down regulation was introduced in the 1940s and new research has been poorly supported. There is however an urgent need to develop new criteria to distinguish those patients with localised disease who will benefit from intervention from those that do not require it or who will have occult extra prostatic metastases. Similarly, there is an urgent need to develop new treatments for those in whom the disease is extra-prostatic and therefore incurable by conventional treatments. This review covers the latest developments in epidemiology, cellular and molecular biology including new areas such as ion channels in the field of prostate cancer.

Adult↗
PubMed1997

Expression of bcl-2 and p53 oncoproteins in schistosomiasis-associated transitional and squamous cell carcinoma of urinary bladder.

OBJECTIVES: To analyze the expression of bcl-2 and p53 proteins in schistosomiasis-associated bladder cancer compared to adjacent urothelium showing morphological alteration including hyperplasia, metaplasia and dysplasia. MATERIALS AND METHODS: Twenty-two formalin-fixed and paraffin-embedded samples of histologically confirmed schistosomiasis-associated bladder tumours were assessed for grade, pathological stage (pT category) and the presence of hyperplasia, metaplasia and dysplasia in adjacent mucosa. There were 11 transitional cell carcinomas (TCCs), 10 squamous cell carcinomas (SCCs) and one diffuse infiltrating (signet-ring cell type) adenocarcinoma. Epithelial hyperplasia was observed in seven cases and metaplasia in 18, most of which were squamous except for a single case of glandular metaplasia. Focal dysplastic areas were observed in eight cases. Sections were stained immunohistochemically for the expression of bcl-2 and p53 proteins. RESULTS: Immunoreactivity for bcl-2 was present in seven of 22 cases (four SCCs and three TCCs) of which three cases (two SCCs and one TCC) were strongly positive, but in contrast to previous studies, there was no increase in the poorly differentiated tumours, bcl-2 was absent in metaplastic and dysplastic epithelium (except in a single case of glandular metaplasia) but it was present at low levels in basal cells of morphologically normal or hyperplastic transitional epithelium in 15 of 22 cases. Nine of 11 TCCs and seven of 10 SCCs showed p53 nuclear immunoreactivity. Heterogenous weak to moderate immunoreactivity for p53 was seen in 13 of 18 cases of metaplasia and in seven of eight cases of dysplasia in the mucosa adjacent to tumours, p53 was absent in normal and hyperplastic urothelium. Co-expression of p53 and bcl-2 was only seen in well differentiated areas of three tumours (two SCCs and one TCC). CONCLUSION: This study detected the expression of bcl-2 in a subset of bladder cancers (32%), whereas most (72%) of the tumours expressed immunoreactive p53. Additionally, p53 was also detected in metaplastic and dysplastic epithelium. Over-expression of both p53 and bcl-2 in the same tumour was only evident in a minority of schistosomiasis-associated cancers (13%). There was no inverse relationship of p53 and bcl-2 immunoreactivity.

Adult↗
PubMed1997

Expression of bcl-2 in bladder neoplasms is a cell lineage associated and p53-independent event.

AIMS: To investigate bcl-2 and p53 protein expression in hyperplastic, metaplastic and neoplastic epithelia of the urinary bladder in relation to cell lineages (transitional versus glandular epithelia). METHODS: Formalin fixed, paraffin wax embedded archival tissue blocks of 29 transitional cell carcinomas (TCC), 11 adenocarcinomas, five specimens of cystitis glandularis, four papillomas, and seven samples of morphologically normal bladder mucosa were examined immunohistochemically with antibodies specific to bcl-2 and p53. Consecutive sections were used to assess co-expression of the two proteins. RESULTS: bcl-2 protein was expressed heterogeneously in basal cells of the normal transitional epithelium, whereas p53 was rarely detectable in either normal or hyperplastic epithelium. Of the 29 TCCs, 20 (69%) expressed immunodetectable p53 which was positively associated with grade. In contrast, bcl-2 was detected in four (14%) TCCs and its expression was not associated with grade. bcl-2 was expressed constitutively in all five specimens of cystitis glandularis and in all adenocarcinomas; p53 was co-expressed in most of the latter. There was no association between bcl-2 and p53 protein expression in the TCCs. Expression of bcl-2 protein correlated negatively with grade of adenocarcinoma. CONCLUSION: In bladder adenocarcinomas, bcl-2 expression correlated negatively with tumour grade whereas p53 was associated positively with tumour grade. The association of bcl-2 with cystitis glandularis and adenocarcinoma but not TCC suggests that it may be involved in triggering a lineage switch converting transitional epithelium to a glandular phenotype.

Adenocarcinoma↗
PubMed1997

Expression and functional analysis of voltage-activated Na+ channels in human prostate cancer cell lines and their contribution to invasion in vitro.

Ion channels are important for many cellular functions and disease states including cystic fibrosis and multidrug resistance. Previous work in the Dunning rat model of prostate cancer has suggested a relationship between voltage-activated Na+ channels (VASCs) and the invasive phenotype in vitro. The objectives of this study were to 1) evaluate the expression of VASCs in the LNCaP and PC-3 human prostate cancer cell lines by Western blotting, flow cytometry, and whole-cell patch clamping, 2) determine their role in invasion in vitro using modified Boyden chambers with and without a specific blocker of VASCs (tetrodotoxin). A 260-kd protein representing VASCs was found only in the PC-3 cell line, and these were shown to be membrane expressed on flow cytometry. Patch clamping studies indicated that functional VASCs were present in 10% of PC-3 cells and blocking these by tetrodotoxin (600 nmol/L) reduced their invasiveness by 31% (P = 0.02) without affecting the invasiveness of the LNCaP cells. These results indicate that the reduction of invasion is a direct result of VASC blockade and not a nonspecific action of the drug. This is the first report of VASCs in a human prostatic cell line. VASCs are present in PC-3 but not LNCaP cells as determined by both protein and functional studies. Tetrodotoxin reduced the invasiveness of PC-3 but not LNCaP cells, and these data suggest that ion channels may play an important functional role in tumor invasion.

Animals↗
PubMed1996

Sociodemographic and symptomatic characteristics of women undergoing stress incontinence surgery in the UK.

OBJECTIVES: To: (i) describe the sociodemographic characteristics of women undergoing surgery for stress incontinence in the UK and the ways in which they differ from women of a similar age in the general population: (ii) the severity and impact of their symptoms and their expectations of surgery and: (iii) their general state of health. PATIENTS AND METHODS: A prospective cohort study was carried out on 442 women undergoing surgery for stress incontinence in 18 hospitals in the North Thames region between January 1993 and June 1994. Sociodemographic factors, stress incontinence severity, symptom impact scores, and general health status were measured. RESULTS: Women undergoing surgery for stress incontinence were similar to their peers in the general population apart from being more likely to have smoked (61.4 against 51.1%), to have subsequently given up (39.5 and 25.3%) and to be of higher parity (> or = 4; 19.7 and 12.0%). Most women (81.6%) reported moderate to very severe stress incontinence. The impact of symptoms was correlated positively with severity (P < 0.001) after accounting for its positive correlation with mental health status (P < 0.005), socioeconomic status (P < 0.05) and its negative correlation with age (P < 0.02). Many women also suffered from other urinary symptoms including urgency (76%) and frequency (42.3%). Apart from their urinary problems, women were in good health (77% reported no or only mild coexistent conditions). However, a very high proportion (34.2%) had previously undergone a hysterectomy. CONCLUSIONS: These results suggest that women undergoing stress incontinence surgery are remarkably similar to their peers, apart from their primary condition. The effect that stress incontinence has on women's lives depends not only on the severity of the problem but also on other factors. The high rate of previous hysterectomy warrants further study.

Adult↗
PubMed1996

Differences between doctor and patient estimates of outcome in male sub-fertility clinic attenders.

Treatment for male factor sub-fertility is limited, with low increases in pregnancy rate. Couples attending a male sub-fertility clinic are provided with prognostic information and advised about treatment options. This study aimed to examine the influence of clinic attendance on male sub-fertility patients' expectations of their partners becoming pregnant. Data were collected on 103 male sub-fertility clinic attenders before and after clinic consultation. Patients' mood and expectations of their partners achieving a pregnancy were recorded and compared with the consultant's expectations. Before consultation, patients expected that following the clinic visit their chance of pregnancy would be increased. Post-consultation, their perceptions of their chances of pregnancy were often inaccurate and were more influenced by their own expectations than by the consultant's view. There was no overall correlation between anxiety or depression and estimation of achieving a pregnancy. The clinical implications of these findings are discussed.

Adult↗
PubMed1995

Differential expression of voltage-activated Na+ currents in two prostatic tumour cell lines: contribution to invasiveness in vitro.

The voltage-gated ionic currents of two rodent prostatic cancer cell lines were investigated using the whole-cell patch clamp technique. The highly metastatic Mat-Ly-Lu cells expressed a transient, inward Na+ current (blocked by 600 nM tetrodotoxin), which was not found in any of the weakly metastatic AT-2 cells. Although both cell lines expressed a sustained, outward K+ current, this occurred at a significantly higher density in the AT-2 than in the Mat-Ly-Lu cells. Incubation of the Mat-Ly-Lu cell line with 600 nM tetrodotoxin significantly reduced the invasive capacity of the cells in vitro. Under identical conditions, tetrodotoxin had no effect on the invasiveness of the AT-2 cells.

Animals↗
PubMed1994

Incidence, racial differences, and prognostic significance of prostate carcinomas diagnosed with obstructive symptoms.

BACKGROUND: It is unknown how often prostate carcinomas are diagnosed as a result of urinary obstructive symptoms or whether prostate carcinomas diagnosed because of obstructive symptoms have a favorable or unfavorable prognosis. It is also unknown whether racial differences in obstructive symptoms could help explain why black men with prostate carcinoma are diagnosed with more advanced stages and grades of prostate carcinoma than are white men with prostate carcinoma. METHOD: At a single Veterans Administration Medical Center, 478 consecutive cases of prostate carcinoma diagnosed between 1973 and 1985 were identified. The incidence of obstructive symptoms at diagnosis, racial differences in obstructive symptoms, and the survival of patients with and without obstructive symptoms, stratified by stage and grade, were determined. In addition, racial differences in the frequency of surgical intervention required to relieve the obstructive symptoms were determined. RESULTS: All patients diagnosed with Stage A prostate carcinoma and most (82%) patients diagnosed with Stage C prostate carcinoma had obstructive symptoms. Those diagnosed with Stage B and Stage D prostate carcinomas had with similar frequencies (53% and 55%, respectively) of obstructive symptoms. Survival, stratified by stage and grade, was similar for men with and without obstructive symptoms. The incidences of obstructive symptoms and the frequency of surgical intervention to relieve the obstructive symptoms, stage for stage, were similar for white and black men. CONCLUSION: Survival, stratified by stage and grade, is not affected adversely by obstructive symptoms. Neither racial differences in the incidence of obstructive symptoms nor the frequency with which obstructive symptoms require surgical correction explain why black men with CAP consistently are diagnosed more frequently with Stage D prostate carcinoma and less frequently with Stage A CAP than white men with CAP.

Adult↗
PubMed1994

Effect of fish oil on cancer cachexia and host liver metabolism in rats with prostate tumors.

The aim of this study was to investigate whether tumor-induced cachexia and aberrations in host liver metabolism, induced by the MAT-LyLu variant of the Dunning prostate tumor, could be prevented by omega 3 fatty acids from fish oil. On day 0, adult Copenhagen-Fisher rats fed normal chow ad libitum were inoculated with 10(6) MAT-LyLu cells (n = 14) or saline (n = 9). On day 7, when tumors were palpable, four tumor-bearing (TB) and four nontumor-bearing (NTB) rats were put on isocaloric diets with 50% of total energy as fish oil. The introduction of fish oil-enriched diets caused a reduction in energy intake to less than half of the energy intake by animals fed normal diets during days 7-14 (difference by dietary group: NTB, P < 0.001; TB, P < 0.001). During days 14-21, energy intake in fish oil-fed animals returned to approximately 75% of energy intake by animals fed normal diets (difference by dietary group: NTB, P < 0.003; TB, P = 0.001). Carcass weight of animals on day 21, when the study was terminated, was significantly related to initial weight (P = 0.05) and mean food intake during the study (P = 0.01). When data were adjusted for these variables using analysis of covariance, with NTB animals on normal diets being the reference group, significant loss of carcass weight was observed in TB animals on normal diets only (mean +/- SEM 58 +/- 10 g loss, P < 0.001), but not in TB animals on fish oil diets (8 +/- 18 g loss, P = 0.67).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗