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Biomedical subjects

A Pollack

Publications and source records attributed to A Pollack.

At least 55 records · Page 3Linked to original sources
PubMed2000

Optic nerve head blood flow measurements in non-arteritic anterior ischaemic optic neuropathy.

PURPOSE: To determine whether a decrease in blood flow, measured by the Heidelberg retiinal flowmeter, can characterise a disc at risk and predict the occurrence of non-arteritic anterior ischaemic optic neuropathy (NAION). METHODS: Blood flow, volume and velocity were measured in the optic nerve heads of 14 unaffected fellow eyes of patients with unilateral NAION, and compared with those of the affected eyes and of the eyes of 7 age-matched healthy controls. RESULTS: The affected eyes were found to differ from the unaffected eyes in all three haemodynamic parameters. Flow (measured in arbitrary units) is the most important parameter to be taken into consideration. Blood flow was significantly lower in affected than in unaffected eyes (upper rim, p < 0.05; lower rim, p < 0.025). It was also significantly lower in the unaffected eyes than in the healthy control eyes (p < 0.005, upper and lower rims), and in the affected eyes than in the control eyes (p < 0.00005, upper and lower rims). CONCLUSION: Decreased blood flow in the optic nerve head may indicate a risk for NAION and be considered a characteristic of the disc at risk.

Aged↗
PubMed2000

Two-stage cervical cancer screening: an alternative for resource-poor settings.

OBJECTIVE: We sought to introduce 2-stage cervical cancer screening in which 2 screening tests are performed sequentially (the second test is performed only if the first result is positive), followed by treatment if both test results are abnormal. STUDY DESIGN: A total of 1423 women from Cape Town, South Africa, were screened by direct visual inspection, human papillomavirus deoxyribonucleic acid testing, cytologic testing, and cervicography. If an abnormality was identified with any test, women were referred for colposcopy. RESULTS: Direct visual inspection, cytologic testing, human papillomavirus deoxyribonucleic acid testing, and cervicography, when used alone, identified 24, 26, 23, and 23 cases of disease (high-grade squamous intraepithelial lesion or cancer) per 1000 women, respectively, and would classify 182, 71, 137, and 112 women without disease as having abnormal results. Two-stage screening with direct visual inspection first, followed by cytologic testing, human papillomavirus deoxyribonucleic acid testing, or cervicography, would detect 18, 16, and 18 cases per 1000 women, respectively, and would substantially reduce the number of women without disease who were classified as having abnormal results. CONCLUSION: Two-stage screening for cervical cancer provides an attractive alternative to conventional screening for low-resource settings.

Adult↗
PubMed2000

Unusual gingival presentation of post-transplantation lymphoproliferative disorder: a case report and review of the literature.

Post-transplantation lymphoproliferative disorder is a well-documented complication of solid organ or bone marrow transplantation. Histologically, it is characterized by an abnormal proliferation of lymphocytes, which can range from benign B-cell hyperplasia to malignant lymphoma. Non-Hodgkin's lymphoma (NHL) is associated with several risk factors, such as congenital or acquired immunodeficiency states, autoimmune disorders, and infectious agents (eg, Epstein-Barr virus). Primary sites of presentation in the head and neck are Waldeyer's ring, paranasal sinuses, salivary glands, the oral cavity, and the larynx. Clinical appearance of gingival NHL varies but is usually found to be an asymptomatic gingival enlargement or mass resembling a pyogenic granuloma. We present a patient with a gingival ulceration that was subsequently diagnosed as Epstein-Barr virus malignant lymphoma resulting from the immunosuppression needed to prevent graft-versus-host disease after bone marrow transplantation.

Adult↗
PubMed2000

Prognostic factors in prostate cancer. College of American Pathologists Consensus Statement 1999.

BACKGROUND: Under the auspices of the College of American Pathologists, a multidisciplinary group of clinicians, pathologists, and statisticians considered prognostic and predictive factors in prostate cancer and stratified them into categories reflecting the strength of published evidence and taking into account the expert opinions of the Prostate Working Group members. MATERIALS AND METHODS: Factors were ranked according to the previous College of American Pathologists categorical rankings: category I, factors proven to be of prognostic importance and useful in clinical patient management; category II, factors that have been extensively studied biologically and clinically but whose importance remains to be validated in statistically robust studies; and category III, all other factors not sufficiently studied to demonstrate their prognostic value. Factors in categories I and II were considered with respect to variations in methods of analysis, interpretation of findings, reporting of data, and statistical evaluation. For each factor, detailed recommendations for improvement were made. Recommendations were based on the following aims: (1) increasing uniformity and completeness of pathologic evaluation of tumor specimens, (2) enhancing the quality of data collected pertaining to existing prognostic factors, and (3) improving patient care. RESULTS AND CONCLUSIONS: Factors ranked in category I included preoperative serum prostate-specific antigen level, TNM stage grouping, histologic grade as Gleason score, and surgical margin status. Category II factors included tumor volume, histologic type, and DNA ploidy. Factors in category III included perineural invasion, neuroendocrine differentiation, microvessel density, nuclear roundness, chromatin texture, other karyometric factors, proliferation markers, prostate-specific antigen derivatives, and other factors (oncogenes, tumor suppressor genes, apoptosis genes, etc).

Biomarkers, Tumor↗
PubMed2000

Cyclophosphamide and carboplatin and selective consolidation in advanced seminoma.

This prospective Phase II study assesses the clinical efficacy and complications of a treatment regimen of combination chemotherapy with cyclophosphamide and carboplatin and selective consolidation in advanced seminoma. Of 46 patients who entered the study between December 1992 and October 1998, 46 were evaluable. Thirty-two achieved a complete remission (70%; 95% confidence interval, 56-83%) after chemotherapy alone. Fourteen achieved a complete remission (30%; 95% confidence interval, 18-46%) after chemotherapy plus consolidation. Forty-three of the 46 patients (93%; 95% confidence interval, 82-97%) remained in remission after a median follow-up period of 27.4 months. No patient experienced nephrotoxic, neurotoxic, or ototoxic effects or hemorrhagic cystitis. No patient had neutropenic fever requiring hospitalization. Thirteen % required platelet transfusions, and 9% required transfusions of packed RBCs. For patients with advanced seminoma, treatment with cyclophosphamide and carboplatin and selective consolidation is safe and effective.

Adolescent↗
PubMed2000

Prostate cancer radiosensitization in vivo with adenovirus-mediated p53 gene therapy.

An adenovirus 5 vector containing wild-type p53 cDNA (Ad5-p53) and a cytomegalovirus promoter was used to generate p53 transgene expression. Control vector (Ad5-pA) contained the poly-adenosine sequence. PC3 cells (2 x 10(6)) were injected s.c. into the legs of nude mice. Treatment with Ad5-p53 was initiated at a tumor volume of 200 mm3. Three intratumoral injections (days 1, 4, and 7) were given with 3 x 10(8) plaque-forming units, followed by 5 Gy pelvic irradiation (day 8) in one fraction using a cobalt-60 source. Tumor volume measurements were obtained every 2 days. LNCaP cells (2 x 10(6)) were injected orthotopically into the prostates of nude mice, and tumor weight was approximated using serum prostate-specific antigen (PSA) obtained from weekly tail vein bleedings. The target PSA for the start of the studies was 5 ng/ml. The intraprostatic injections of Ad5-p53 were done twice (days 1 and 2) and followed by 5 Gy pelvic irradiation on day 3. The PC3 tumor volume growth curves were log transformed and fitted using linear regression. The times (in days) for the tumors to reach 500 mm3 were calculated as 10.7 +/- 0.7 (+/- SE) for the saline control (no virus), 9.8 +/- 2.1 for Ad5-pA, 15.6 +/- 1.6 for Ad5-p53, 14.6 +/- 1.5 radiation therapy (RT; 5 Gy), 14.6 +/- 1.5 for Ad5-pA plus RT, and 31.4 +/- 5.3 for Ad5-p53 plus RT. The Ad5-p53 plus RT times were significantly different from the other groups. An enhancement factor of 3.4 was calculated, indicating supra-additivity. LNCaP tumor growth was determined via weekly serum PSA measurements. Treatment failure was determined using two PSA-based methods; a serum PSA of > 1.5 ng/ml or two rises in PSA during 6 weeks posttreatment. The results were similar using either end point. Treatment with Ad5-p53 plus 5 Gy resulted in significantly fewer PSA failures (<30%), as compared with Ad5-p53 alone (64-73%) and the other controls (approximately 80-100%) These results are also consistent with a supra-additive inhibition of tumor growth. Tumor growth in vivo was inhibited supra-additively when p53null and p53wildtype prostate tumors were treated with Ad5-p53 and 5 Gy radiation.

Adenoviridae↗
PubMed2000

[Surgery for blepharoptosis in muscular dystrophy].

In some muscular dystrophies there is ocular involvement characterized by blepharoptosis and ophthalmoplegia. These conditions occur in chronic progressive external ophthalmoplegia, oculopharyngeal muscular dystrophy, mitochondrial myopathy, myotonic dystrophy, and ocular myasthenia, among others. Although they differ in their systemic clinical manifestations and in genetic inheritance, ocular involvement is common to all of them. Manifestations include bilateral progressive blepharoptosis with or without extraocular muscle malfunction. During surgical repair of the ptotic eyelid, consideration must be given to eyeball movements, in addition to maximal eyelid elevation, and to avoiding overcorrection and consequent corneal overexposure, leading to dryness and visual impairment. With these muscular dystrophic disorders, resection of the levator muscle or blepharoplasty alone does not suffice. Follow-up shows that most patients need a secondary repair after a short while. Operative correction uses a frontalis sling for eyelid elevation and support. A series of 8 patients with these diseases, operated on by various surgical techniques during the past 7 years, is presented.

Adolescent↗
PubMed1999

Relationship of Ki-67 labeling index to DNA-ploidy, S-phase fraction, and outcome in prostate cancer treated with radiotherapy.

BACKGROUND: Our purpose was to evaluate the relationship of Ki-67 labeling index (Ki67-LI) to deoxyribonucleic acid (DNA) ploidy, S phase fraction (SPF), other clinical prognostic factors, and clinical outcome for patients with prostate cancer treated by external beam radiotherapy. METHODS: Tissue was retrieved from 42 patients who underwent transurethral resection of the prostate before treatment with external beam radiotherapy between 1987-1993. DNA histogram profiles were classified as diploid (diploid + near-diploid) and nondiploid (tetraploid + aneuploid). Immunohistochemical staining of Ki-67 by the MIB-1 monoclonal antibody was used to calculate Ki67-LI. Median patient follow-up was 62 months. Treatment failure was defined as two consecutive rises in serum prostate-specific antigen (PSA) or clinical evidence of disease recurrence. RESULTS: The mean and median Ki67-LIs were 3.1 and 2.4, respectively (range, 0-12.4). Mean Ki67-LI values were significantly associated with higher stage, Gleason score, and pretreatment PSA. Nondiploid tumors had significantly higher Ki67-LIs, as did patients who failed radiotherapy over the follow-up period. SPF was not significantly correlated with Ki67-LI. As a categorical variable, the most significant relationships were seen when Ki67-LI was subdivided into thirds around the median (Ki67-LI </=1.5%, Ki67-LI >1.5-3.5%, and Ki67-LI >3.5%). This trichotomous variable correlated significantly with pretreatment PSA (P = 0.0008), tumor stage (P = 0.016), Gleason score (P = 0.024), and treatment failure (P = 0.0015), but not with DNA-ploidy (P = 0.15). In actuarial univariate analyses, Ki67-LI appeared to be a more significant predictor of patient outcome (P = 0.003) than DNA-ploidy (P = 0.035). CONCLUSIONS: The Ki67-LI correlated with known prognostic factors such as pretreatment PSA, tumor stage, and Gleason score, and was also weakly related to DNA-ploidy. In comparison to DNA-ploidy, Ki67 LI seems to be a better correlate of treatment outcome.

Aged↗
PubMed1999

Conventional external-beam radiation therapy alone or with androgen ablation for clinical stage III (T3, NX/N0, M0) adenocarcinoma of the prostate.

PURPOSE: To evaluate the outcome of clinical Stage III (T3, N0/NX, M0) prostate cancer treated by conventional radiation alone or with adjuvant androgen ablation. METHODS AND MATERIALS: Three hundred forty-four men with T3, N0/NX, M0 adenocarcinoma of the prostate who received conventional radiation alone (260) or with androgen ablation (84) were analyzed for relapse or rising prostate-specific antigen (PSA), using univariate and multivariate techniques. RESULTS: With a median follow-up of 68 months, the 260 men treated with radiation alone had a 10-year actuarial rate of relapse or rising PSA of 76%. Pretreatment PSA level (< or = 10 ng/ml vs. > 10 < or = 20 ng/ml vs. > 20 ng/ml) and radiation dose (< 68 Gy vs. > or = 68 Gy) were the only independently significant determinants of biochemical failure; Gleason score (2-7 vs. 8-10) was an additional determinant of metastatic relapse. Patients treated to doses < 68 Gy experienced 6-year failure rates exceeding 50% regardless of PSA level. Patients with PSA < or = 10 ng/ml and receiving 68-70 Gy had a 6-year failure of 24%, but those with PSA > 10 ng/ml had relapse rates exceeding 50% even at doses of 70 Gy. At a median follow-up of 44 months, the 84 patients treated with radiation and androgen ablation had a 6-year biochemical failure rate of 22%. The only significant determinant of outcome in this group was pretreatment PSA; patients with PSA < or = 80 ng/ml had a 6-year failure rate of only 12% compared to a failure rate of 53% for those with PSA > 80 ng/ml. The outcome for those treated with combined modalities was significantly better than for those treated with radiation alone in all PSA strata. CONCLUSION: Conventional radiation alone has little curative potential for Stage III disease. Doses < 68 Gy are particularly ineffective. Patients with PSA < or = 10 ng/ml may be candidates for conventional radiation to a dose of 70 Gy. Other patients are probably best served by combined radiation-androgen ablation or high-dose conformal radiation.

Acid Phosphatase↗
PubMed1999

Transrectal ultrasound for staging prostate carcinoma prior to radiation therapy: an evaluation based on disease outcome.

BACKGROUND: Despite its subjectivity and inaccuracy, digital rectal examination (DRE) has a long history of well-documented prognostic significance in patients with prostate carcinoma. To the authors' knowledge, very few studies have evaluated the relative prognostic merits of transrectal ultrasound (TRUS) versus DRE. This question is addressed in this study. METHODS: The outcome for 558 men with T1-T3, N0, M0 adenocarcinoma of the prostate who underwent both DRE and TRUS and received external beam radiation without androgen ablation was evaluated relative to the prognostic information from DRE, TRUS, or both. The outcome endpoints were no evidence of disease (NED) (no relapse or rising prostate specific antigen level) and freedom from metastases. Prognostic factors were evaluated with univariate and multivariate techniques. The median follow-up was 55 months. RESULTS: Both purely DRE-based and purely TRUS-based T categories correlated significantly with NED status. For DRE T categories, 6-year NED rates for T1/T2 and T3 disease were 64% and 36%, respectively (P < 0.001). For TRUS T categories, the rates for T1/T2 and T3 were 63% and 39%, respectively (P < 0.001). There were significant differences in patient composition between DRE and TRUS T categories. Only 40% of patients were in the same DRE and TRUS category, but the majority of the reclassification based on TRUS was within rather than between major T categories (T1/T2 vs. T3). Changes between the prognostically significant T1/T2 versus T3 categories occurred in < or =25%. This accounted for the similarity in NED outcome for DRE and TRUS T categories. However, TRUS categories did not discriminate significantly for metastatic recurrence between T1/T2 and T3 categories, whereas DRE categories did. Upstaging or downstaging by TRUS relative to DRE did not alter the DRE prognostic groupings substantially. CONCLUSIONS: There was no clinically meaningful superiority of TRUS over DRE in the definition of prognostically useful T categories. Moreover, the addition of TRUS to DRE did not enhance the prognostic value of DRE findings in any meaningful way. Despite its subjectivity and inaccuracy, DRE provides prognostic information at least equivalent to TRUS and is preferable because of its low cost.

Adenocarcinoma↗