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Biomedical subjects

C N Robertson

Publications and source records attributed to C N Robertson.

At least 37 records · Page 2Linked to original sources
PubMed1995

Knowledge, beliefs, and prior screening behavior among blacks and whites reporting for prostate cancer screening.

OBJECTIVES: A survey to determine prostate cancer-related knowledge, beliefs, and prior screening behavior was administered to men participating in prostate cancer screening events at nine major sites in the southeast. Since prostate cancer disproportionately affects blacks, a primary focus of the analysis was to determine if differences in responses exist between racial groups. METHODS: A 20-question, multiple-choice survey to ascertain prostate cancer knowledge and beliefs, demographics, and health care access information was administered at nine major southeastern sites participating in Prostate Cancer Awareness screening events. Potential differences between the responses of blacks and whites were tested using the Cochran-Mantel-Haenszel test (P < 0.05), adjusting for differences among sites. RESULTS: Major findings of this study on 286 black and 1218 white men are as follows: (1) only 28% of black or white men report that their doctor ever discussed a test for prostate cancer with them; (2) blacks were less likely to have a regular doctor (P = 0.03) or ever to have had a digital rectal examination (P < 0.001) or prostate-specific antigen testing (P = 0.005); (3) blacks were less likely to report knowing someone with prostate cancer (P < 0.001) and were more apt to report their acquaintances experiencing post-treatment impotence than whites (P = 0.03); they were less likely to report that "a man with prostate cancer can lead a normal life" (P < 0.001) or that "men can have prostate cancer without symptoms" (P < 0.001); (4) a substantial number of all men did not know that race and/or heredity are risk factors; and (5) "peace of mind" was the leading reason why men (63% of whites and 50% of blacks) attended prostate cancer screening events. CONCLUSIONS: There are a number of similarities among black and white men regarding knowledge and beliefs related to prostate cancer. Important differences, however, in access to screening, perception of the disease and its treatment, and knowledge of risk factors exist between racial groups and represent significant barriers to early detection among African Americans.

Black or African American↗
PubMed1995

The alpha 1C-adrenoceptor in human prostate: cloning, functional expression, and localization to specific prostatic cell types.

1. Benign prostatic hyperplasia (BPH) causes urinary obstruction in aging men that frequently requires surgery to relieve the symptoms of urinary retention, nocturia, and micturition. Smooth muscle tone which contributes to the urethral constriction in the enlarged gland appears to be mediated by the alpha 1-adrenoceptors. In this paper, molecular and pharmacological approaches are used to establish the role played by the alpha 1C-adrenoceptor subtype in the prostate. 2. The alpha 1-adrenoceptor subtype(s) expressed in human prostate were investigated by use of polymerase chain reaction (PCR), Northern blot, and in situ hybridization. The alpha 1C subtype was found in both prostate stromal and glandular cells while alpha 1B and alpha 1D subtypes were expressed in glandular cells. High expression levels for alpha 1C were observed in prostate cancer tissues in both stroma and glandular cells. 3. Full length alpha 1C-adrenoceptor cDNA was cloned from human prostate. Stable mammalian cell lines expressing human alpha 1B-, alpha 1C-, and alpha 1D-adrenoceptors were made. Membranes prepared from these cell lines and human prostate were used to evaluate the pharmacological profiles of human alpha 1B-, alpha 1C- and alpha 1D-adrenoceptors in comparison to human prostate. Leverage plot analysis of compound affinities determined by competition for [125I]-I-HEAT binding demonstrated that the alpha 1C subtype is the predominant alpha 1-adrenoceptor in human prostate. 4. The alpha 1-adrenoceptors cause smooth muscle constriction by coupling to IP3 turnover and intracellular Ca2+ release. Using stable cell lines to measure IP3 production in response to noradrenaline, alpha 1C stimulated IP3 production most efficiently, with alpha 1B at an intermediate level, while little IP3 above background could be detected with alpha 1D. These results supported a functional role of the alpha 1C-adrenoceptor on prostate smooth muscle constriction by noradrenaline stimulation.

Amino Acid Sequence↗
PubMed1994

Differential immunoreactivity of transforming growth factor alpha in benign, dysplastic and malignant prostatic tissues.

Immunohistochemical examination of radical prostatectomy specimens from 57 patients was performed to determine the differential expression of transforming growth factor alpha in the human prostate. In addition, epidermal growth factor receptor (EGFr) immunoreactivity was assessed in each case. Stromal versus epithelial staining was determined for each histological subtype: benign prostatic hypertrophy (BPH), prostatic intra-epithelial neoplasia (PIN), and prostatic cancer (CaP) by a single pathologist reviewer. TGFa staining was predominant in stroma while EGFr was localized to the epithelial basal cell layer. Immunoreactivity of both TGFa (P = 0.002) and EGFr (P < 0.001) revealed a significant reduction in CaP compared to BPH or PIN. Autocrine stimulation of EGFr by TGFa or other unrecognized factors may be present in CaP. Conversely, altered stromal influence of CaP via TGFa may be present. These observations could form the basis for future cancer therapeutic strategies using antagonist factors.

Aged↗
PubMed1993

Genetic risk and carcinogen exposure: a common inherited defect of the carcinogen-metabolism gene glutathione S-transferase M1 (GSTM1) that increases susceptibility to bladder cancer.

BACKGROUND: Numerous studies have associated bladder cancer with exposure to carcinogens present in tobacco smoke and other environmental or occupational exposures. Approximately 50% of all humans inherit two deleted copies of the GSTM1 gene which encodes for the carcinogen-detoxification enzyme glutathione S-transferase M1. Recent findings suggest that the GSTM1 gene may modulate the internal dose of environmental carcinogens and thereby affect the risk of developing bladder cancer. PURPOSE: We investigated whether the absence of the GSTM1 gene affects bladder cancer risk and whether there are racial differences in GSTM1 genotype frequency. METHODS: Using a polymerase chain reaction (PCR)-based method, we examined the frequency of the homozygous deleted genotype (GSTM1 0/0) in 229 patients with transitional cell carcinoma of the bladder and 211 control subjects who were enrolled from the Urology Clinics at Duke University Medical Center and the University of North Carolina Hospitals. Control subjects were urology clinic patients who primarily presented with benign prostatic hypertrophy or impotence, who had no history of any cancer other than nonmelanoma skin cancer, and who were frequency matched to case patients on race, sex, and age (10-year age intervals). In order to explore racial differences in GSTM1 gene frequency, genotype was also determined in a community-based sample of 466 paid, healthy, unrelated volunteers from Durham and Chapel Hill, N.C. The presence or absence of the GSTM1 gene locus was determined by using a differential PCR, a semiquantitative technique in which multiple genes are coamplified. RESULTS: Overall, the GSTM1 0/0 genotype conferred a 70% increased risk of bladder cancer (odds ratio [OR] = 1.7; 95% confidence interval [CI] = 1.2-2.5; P = .004). Absence of the GSTM1 gene encoding the glutathione S-transferase M1 enzyme significantly increased risk to persons with exposure to the carcinogens in tobacco smoke (OR = 1.8; 95% CI = 1.2-3.0; P = .01) but poses little increased risk to persons without such exposure. Persons with smoking exposure of more than 50 pack-years who had the GSTM1 0/0 genotype had a sixfold greater risk relative to persons in the lowest risk group (i.e., nonsmokers who were GSTM1 +/+ or +/0). In the pooled clinic control and community sample groups (677 individuals), the GSTM1 0/0 genotype occurred less frequently among Blacks (35%) than among Whites (49%, P < .001). CONCLUSIONS: These findings support a protective role for the GSTM1 gene in bladder cancer. From these findings, it is estimated that 25% of all bladder cancer may be attributable to the at-risk GSTM1 0/0 genotype.

Base Sequence↗
PubMed1993

Characteristics of men reporting for prostate cancer screening.

A survey to determine demographics, prostate cancer screening practices, and prostate cancer-related knowledge and beliefs was administered to over 1,700 participants at five sites during Prostate Cancer Awareness Week (1991) screening events. Findings are presented by site since significant differences in demographics existed. Results suggest that screenings conducted at the major medical centers attract primarily white males, a number of whom already practice adequate secondary prevention. Thus, if optimal benefit is sought through mass prostate cancer screening, innovative strategies to reach populations that are currently underserved and at risk are necessary.

Adult↗
PubMed1993

Differential immunoreactivity of epidermal growth factor receptor in benign, dysplastic and malignant prostatic tissues.

To investigate epidermal growth factor receptor (EGFr) presence in the prostate, monoclonal antibody (clone EGFR1) immunohistochemical examination of radical prostatectomy specimens was performed (n = 37). All prostatic specimens contained benign prostatic hyperplasia (BPH) and/or dysplasia (prostatic intraepithelial neoplasia or PIN), as well as prostatic carcinoma (CaP). Areas of dysplasia were further categorized as to the basal cell layer and the luminal cell area. BPH, PIN, and CaP tissues in each specimen were analyzed by a single observer and graded on a scale from 0-4+. Fifteen samples were also analyzed for EGFr content utilizing a Cell Analysis Systems (CAS 200) image cytometer. EGFr immunoreactivity of BPH basal cells was significantly higher than EGFr immunoreactivity in areas of CaP (p < 0.001). EGFr staining of BPH basal cells was also significantly higher than that seen in PIN luminal cells (p < 0.001). Immunoreactivity of EGFr in PIN basal cells was significantly higher than in PIN luminal cells (p < 0.001). EGFr staining of basal cells in BPH tissues was higher than that seen in the PIN basal cell layer but the difference was not statistically significant (p = 0.06). The amount of staining present in PIN luminal cells was also significantly greater than in CaP tissues (p = 0.002). Quantitative image analysis utilizing the CAS 200 image cytometer was performed on BPH and CaP areas exclusively. EGFr immunoreactivity in basal cells of the BPH tissues was significantly greater than that seen in CaP tissues (p < 0.001). The decreased EGFr immunoreactivity in CaP may reflect a differentiating role for EGFr in normal tissues. Loss of EGFr influence may be associated with an increased proliferative state in PIN and CaP. Destruction or alteration of the epidermal grwoth factor receptor by a protease, such as prostatic specific antigen, may also explain our findings. At the present time the meaning of the different amounts of EGFr in the various types of prostate tissues is unknown.

Aged↗
PubMed1992

Differential immunoreactivity of her-2/neu oncoprotein in prostatic tissues.

To investigate HER-2/neu oncoprotein immunoreactivity, monoclonal antibody TA1 immunohistochemical examination of flash-frozen radical prostatectomy specimens was performed (n = 35). All prostatic specimens contained benign prostatic hyperplasia (BPH) and/or prostatic intraepithelial neoplasia (PIN), as well as prostatic carcinoma (CaP). HER-2/neu oncoprotein immunoreactivity in BPH tissues was not significantly different than that for the PIN basal cell layer (P = 0.10) or for the PIN luminal cells (P = 0.17). There was significantly more HER-2/neu oncoprotein immunoreactivity in BPH than in areas of CaP (P < 0.001). There was no significant difference in the amount of immunoreactivity present in PIN basal cells when compared to the PIN luminal cells (P = 0.49). Both the PIN basal cells and luminal cells stained for the HER-2/neu oncoprotein to a higher degree than cells in the CaP areas (P < 0.001 in both cases). HER-2/neu oncoprotein immunoreactivity is present at a significantly higher degree in BPH and PIN than in malignant prostatic epithelium.

Aged↗
PubMed1992

Detection of human papillomavirus in the prostate by polymerase chain reaction and in situ hybridization.

Human papillomavirus is associated with a variety of anogenital lesions, including genital warts, precancers and cancers. In male patients human papillomavirus has been identified in proliferative lesions ranging from penile and urethral warts to penile and prostatic cancers. We examined the association of human papillomavirus deoxyribonucleic acid (DNA) in 84 prostate tissue specimens. Specimens were selected from radical prostatectomy, transurethral resection or transrectal biopsy procedures. A total of 60 formalin-fixed, paraffin-embedded tissues (24 prostate cancer specimens, 16 benign prostatic hyperplasia specimens and 20 normal specimens) was examined by polymerase chain reaction and in situ hybridization. Also, 24 gelatin-embedded frozen prostate cancer specimens were examined for human papillomavirus DNA by polymerase chain reaction. Of the specimens 69 were deemed adequate for polymerase chain reaction analysis, whereas all 60 paraffin-embedded tissues were sufficient for in situ hybridization. Human papillomavirus DNA was detected in 2 normal tissues and 6 prostate cancers using polymerase chain reaction. None of the benign prostatic hyperplasia specimens was positive for human papillomavirus. Human papillomavirus typing results indicated that virus type 16 was present in each of the 8 positive specimens. Confirmation of the presence of human papillomavirus was obtained for 1 of the prostate cancers by nonisotopic in situ hybridization with biotinylated human papillomavirus genomic probes. The low prevalence of human papillomavirus in this study population does not strongly support an etiological role for the virus in prostate cancer.

Adult↗
PubMed1991

DNA in radical prostatectomy specimens. Prognostic value of tumor ploidy.

In a series of 94 patients with prostatic adenocarcinoma the prognostic significance of some factors was studied after radical prostatectomy. DNA ploidy was assessed by flow cytometry of cells from deparaffinized specimens. Gleason sum, seminal vesicle status and ploidy turned all out to be important predictors of disease progression. The ploidy status significantly enhanced the ability to prognostically evaluate patients with intermediate grade carcinoma compared to tumor grade alone. Patients with seminal vesicle invasion and aneuploidy had a very poor prognosis which prompts trials with alternatives of adjuvant therapy in this patient population.

Adenocarcinoma↗
PubMed1991

The relevance of stage A malignancy in prostatic cancer.

Patients with T1 (stage A) prostatic cancer detected on transurethral resection and patients with T2 (stage B) cancer, identified by palpation and needle biopsy, had similar time to failure and survival following radical prostatectomy. Transurethral resection was not associated with a higher degree of failure. The volume of the tumor and the biology of the disease were decisive of the outcome. In low-grade low-volume prostatic adenocarcinoma the risk of progression is very low.

Aged↗
PubMed1991

Radical surgery versus radiation therapy in early prostatic carcinoma.

Patients with organ-confined prostatic cancer, as determined by digital examination, bone scans and serum acid phosphatase determination, were randomized to radical prostatectomy or external-beam radiation therapy. With respect to first evidence of treatment failure, there was a significant difference in favor of the patients who had surgical treatment. In the patients given radiotherapy there was no essential difference in time to failure as compared with comparable patients in two recent observation-only trials on record.

Bone Neoplasms↗
PubMed1991

Positive margins: is adjunctive radiation therapy indicated?

Patients with margin positive disease after radical prostatectomy are prognostically disadvantaged. The question of postoperative adjunctive radiotherapy in these patients is controversial. A retrospective study suggested that adjunctive radiation therapy reduced the local recurrence rate but did not alter survival.

Combined Modality Therapy↗
PubMed1990

Collecting duct carcinoma of the kidney.

Collecting duct carcinoma is an unusual variant of renal cell carcinoma, whose appearance and behavior are not well established. We identified six cases of collecting duct carcinoma in our files. The clinical, pathologic, and immunohistochemical characteristics of these tumors are reported. The most common symptom was gross hematuria (four cases). Two patients had cervical adenopathy due to metastatic tumor. Four rapidly developed systemic metastases and died within 4 to 24 months. The primary renal tumors were located predominantly in the renal medulla and pelvis and had a partially cystic white-gray appearance. Histologic examination showed prominent tubulopapillary structures, nests of clear cells, and infiltrating tubules in a dense desmoplastic stroma. Atypical hyperplastic changes were found in some of the adjacent collecting ducts. Mucicarminophilic material was present in glandular elements in all six cases. Immunohistochemical studies revealed positivity with antibodies to epithelial membrane antigen, keratins, peanut agglutinin, vimentin, Leu M1 and lysozyme. The location of this tumor in the medulla, its distinctive histologic appearance, mucin positivity, expression of high molecular weight cytokeratins, and peanut agglutinin suggest that this is a distinct clinicopathologic entity which has an aggressive clinical course.

Adult↗
PubMed1990

Preparative cytoreductive surgery in patients with metastatic renal cell carcinoma treated with adoptive immunotherapy with interleukin-2 or interleukin-2 plus lymphokine activated killer cells.

A total of 63 patients with metastatic renal cell carcinoma with the primary kidney tumor in place was accepted as candidates for immunotherapy at the Surgery Branch of the National Cancer Institute. Of the 63 patients 54 underwent nephrectomy and 9 were treated with the primary kidney tumor in place. Many of the patients underwent associated procedures, such as regional lymphadenectomy (11), venacavotomy with extraction of tumor thrombus (9), hepatic resection (2), pulmonary wedge resection (2), cholecystectomy (2), splenectomy (2), distal pancreatectomy (1), omentectomy (1) and contralateral adrenalectomy (1). Of the 54 patients 20 were not able to enter therapy because of tumor-related (17) or other medical (3) reasons that developed between the operation and therapy, while 34 were able to receive immunotherapy postoperatively. The 20 patients who were treated with either high dose interleukin-2 or interleukin-2 plus lymphokine activated killer cells soon postoperatively (mean 2.1 months) were able to tolerate roughly the same amount of interleukin-2 as the 74 who had undergone nephrectomy before referral to our institute and who were treated for a mean of 22 months after nephrectomy. Further studies, including a prospective, randomized trial, will be required to define the role of nephrectomy in patients with advanced renal cell carcinoma before treatment with interleukin-2 based immunotherapies.

Carcinoma, Renal Cell↗
PubMed1990

Epidermal growth factor receptor gene analysis in renal cell carcinoma.

The epidermal growth factor receptor binds the mitogens epidermal growth factor and transforming growth factor-alpha. Increased expression of the epidermal growth factor receptor has been noted in many types of tumors and is associated with gene amplification in several including epidermoid carcinoma, lung carcinoma, breast carcinoma and glioblastoma. We have recently observed increased expression of the epidermal growth factor receptor messenger RNA in neoplastic tissue relative to normal kidney tissue from patients with renal cell carcinoma. To determine if epidermal growth factor receptor gene amplification was present in renal cell carcinoma, DNA was extracted from renal cell carcinoma cell lines and from normal kidney and renal cell carcinoma tissues derived from radical nephrectomy specimens from thirty patients. DNA was analyzed by Southern blot hybridization. There was no epidermal growth factor receptor gene amplification detected in the renal cell carcinoma samples studied, indicating the increased epidermal growth factor gene expression observed in renal cell carcinoma does not occur through gene amplification. Unlike other tumors with enhanced epidermal growth factor receptor gene expression, amplification of this gene does not appear to be a common feature of renal cell carcinoma.

Adenocarcinoma↗
PubMed1990

Surgical management of pheochromocytoma with the use of metyrosine.

Despite recommended preoperative preparation with alpha-adrenergic blockers, severe hemodynamic instability may occur during operations to resect pheochromocytoma. We combined the alpha-blocker phenoxybenzamine with the tyrosine hydroxylase inhibitor metyrosine in an attempt to better manage the hypertension of patients with pheochromocytoma undergoing surgical resection. This report reviews the cases of 25 consecutive patients undergoing surgery for known intra-abdominal pheochromocytoma. Each patient had elevated serum or urine levels of catecholamines or their metabolites. Nineteen patients were prepared before operation with phenoxybenzamine and metyrosine and six patients were given phenoxybenzamine alone. There were no significant differences in maximum, minimum, or mean blood pressure before or after tumor resection between patients who received metyrosine and those who did not. However careful review suggested that those who received metyrosine had more severe disease as judged by biochemical criteria. Study of selected patients matched for age and severity of disease suggested that the intraoperative blood pressure management of patients prepared with phenoxybenzamine and metyrosine was facilitated. In addition metyrosine-prepared patients lost less blood and required less volume replacement during surgery than did non-metyrosine-prepared patients. There were no apparent differences in postoperative fluid requirements. Although the study is not a prospective randomized trial, a retrospective review of patients managed with the combination of phenoxybenzamine and metyrosine suggests that surgery to resect pheochromocytoma can be better performed with both drugs than with phenoxybenzamine alone. The combination regimen appears to result in better blood pressure control, less blood loss, and the need for less intraoperative fluid replacement than does the traditional method of single-agent alpha-adrenergic blockade.

Adrenal Gland Neoplasms↗
PubMed1989

Genetic changes in human adrenocortical carcinomas.

Recent studies have suggested that loss of heterozygosity at loci on the short arm of human chromosome 11 (11p) may be important in the pathogenesis of benign and malignant adrenal cortical tumors. To test this concept, adrenocortical carcinomas from nine patients and benign adrenal cortical lesions from eight patients were tested for loss of alleles at loci on human chromosomes 11, 13, and 17. All patients with adrenocortical carcinoma whose normal somatic tissues were heterozygous for a locus on chromosome 17p had lost alleles in the tumor. Four of six patients with adrenocortical carcinoma who were heterozygous for one or more alleles on chromosome 11p in normal tissues had lost 11p alleles in the tumor. Three of six patients with adrenocortical carcinoma showed loss of 13q alleles in the tumor. Loss of alleles on chromosomes 11p, 13q, and 17p was observed in primary tumors and metastases but not in adrenocortical adenomas or hyperplastic lesions of the adrenal cortex. One patient with adrenocortical carcinoma had a somatic mutation in the HRAS1 gene in the normal adrenal gland. The consistency of the genetic changes on chromosomes 11p, 13q, and 17p suggests that they are important in the pathogenesis of adrenocortical carcinoma.

Adrenal Cortex Neoplasms↗