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Biomedical subjects

A B Gelb

Publications and source records attributed to A B Gelb.

At least 19 recordsLinked to original sources
PubMed2001

Posttransplantation lymphoproliferative disorders in pediatric patients undergoing liver transplantation.

OBJECTIVES: To study the clinicopathologic and molecular genetic findings in posttransplantation lymphoproliferative disorders (PTLDs) following pediatric liver transplantation and to determine the applicability of a recently proposed consensus classification system. DESIGN: The clinical, pathologic, and molecular genetic findings of 11 PTLDs that occurred in 10 patients are presented. These 10 patients were derived from a group of 121 pediatric patients who underwent liver transplantation at the University of California, San Francisco. The PTLDs were classified using the proposed Society for Hematopathology scheme. Clonality was determined by immunohistochemical detection of monotypic immunoglobulin or by using polymerase chain reaction-based methods to detect monoclonal immunoglobulin heavy-chain gene rearrangements. Epstein-Barr virus (EBV) was detected by immunohistochemistry, in situ hybridization, or polymerase chain reaction. Epstein-Barr virus typing and the presence of LMP1 gene deletions were also analyzed by polymerase chain reaction. RESULTS: There were 3 early lesions, 4 polymorphic PTLDs, and 4 monomorphic PTLDs. Monoclonality was demonstrated in 8 of 9 cases assessed. Epstein-Barr virus was present in all cases; of 9 cases assessed by polymerase chain reaction, the virus was type A in 8 and type B in 1. No EBV LMP1 gene deletions were identified. The corresponding liver explants were negative for EBV in 8 cases and positive in 1 case. Greater than 3 foci of disease and monomorphic PTLD were associated with decreased actuarial survival (P <.05). CONCLUSIONS: The prognosis of pediatric patients with PTLD is favorable for early lesions and polymorphous PTLD, particularly in patients with localized disease. Multifocal disease and monomorphic PTLD are associated with an unfavorable prognosis.

Child↗
PubMed1998

Initiating genetic events in small renal neoplasms detected by comparative genomic hybridization.

PURPOSE: To identify the genetic alterations associated with renal adenomas. MATERIALS AND METHODS: We analyzed 37 renal adenomas obtained at autopsy (23 papillary and 14 non-papillary) by comparative genomic hybridization. RESULTS: In papillary tumors, the median number of gains and losses of genetic material per tumor was 2.0 and 1.0, respectively. Papillary tumors were characterized predominantly by gains of genetic material on chromosomes 7 (57%), 17 (35%), 16 (26%), 12 (26%), 3 (22%), 20 (22%) and loss of a sex chromosome (83%). In 6 papillary tumors less than or equal to 5 mm. in diameter, gain of chromosome 7 occurred in 4 specimens. Initiating events for papillary renal adenomas include gain of chromosome 7 and loss of a sex chromosome. In non-papillary tumors, the median number of gains and losses of genetic material per tumor was 1.0 and 1.0, respectively. Non-papillary tumors were characterized by loss of genetic material on chromosome 3p (50%), loss of a sex chromosome (36%) and a gain of chromosome 5 (43%). The initiating event for non-papillary renal adenomas is the loss of chromosome 3p. CONCLUSIONS: Renal adenomas demonstrate similar genetic alterations as clinically detected renal cell carcinomas. Their clinically indolent course may, in part, be a result of the lower number of genetic alterations per tumor than their clinically detected counterparts. Renal adenomas are thus small carcinomas which have not yet acquired the necessary genetic alterations leading to tumor progression.

Aged↗
PubMed1998

Cyclin D1 expression in renal carcinomas and oncocytomas: an immunohistochemical study.

Cyclin D1 plays an important role in cell cycle progression from G1 to S phase. Cyclin D1 overexpression has been identified in many human neoplasms, including a variety of carcinomas. A systematic study of cyclin D1 expression in renal carcinomas and oncocytomas has not been reported. Ninety-six renal epithelial neoplasms, 78 renal carcinomas (45 clear-cell, 18 papillary, and 15 chromophobe), and 18 oncocytomas were analyzed immunohistochemically using routinely fixed tissue sections and a cocktail of two monoclonal anti-cyclin D1 antibodies. One thousand cells were manually counted, and the percentage of cyclin D1 positive cells was calculated. Fluorescence in situ hybridization studies using chromosome 11 centromeric and 11q13 specific probes were performed on a subset of clear-cell carcinomas and oncocytomas. Cyclin D1 immunoreactivity was observed in 23 (51%) of 45 clear-cell, 5 (28%) of 18 papillary, and 2 (13%) of 15 chromophobe carcinomas. Nine (50%) of 18 oncocytomas were positive for cyclin D1. Cyclin D1 expression in clear-cell carcinomas did not correlate with survival. Fluorescence in situ hybridization studies on eight clear-cell carcinomas and seven oncocytomas revealed normal chromosome 11 number and no evidence of amplification of the 11q13 locus. Thus, cyclin D1 can be immunohistochemically demonstrated in approximately one-half of renal oncocytomas and clear-cell carcinomas and is less frequent in papillary and chromophobe carcinomas. The mechanism of cyclin D1 expression is unknown, but it does not seem to be related to extra copies of chromosome 11 or to gene amplification.

Adenocarcinoma↗
PubMed1997

Appraisal of intratumoral microvessel density, MIB-1 score, DNA content, and p53 protein expression as prognostic indicators in patients with locally confined renal cell carcinoma.

BACKGROUND: The prognostic values of intratumoral microvessel density (iMVD), tumor cell proliferation rate, DNA content (ploidy), and p53 protein expression are controversial or have not been well studied in patients with renal cell carcinoma (RCC) confined to the kidney. METHODS: A uniform group of 52 clear cell (conventional) RCCs confined to the kidney (classified as T1N0M0 or T2N0M0) were analyzed for iMVD, MIB-1 score, DNA content, S-phase fraction, and p53 protein expression by immunohistochemical methods or flow cytometry. iMVD was evaluated in a single area (X200, 1.15 mm2) representative of the highest MVD (neovascular "hot spot") after independently highlighting endothelial cells with antibodies specific for factor VIII-related antigen (F8/86) and CD31 (JC/70A). The MIB-1 antibody (Ki-67 antigen) score was used as a marker for the tumor cell proliferation rate. DNA content and S-phase fraction were determined by flow cytometry using paraffin embedded tissue. p53 expression was assessed using the D07 antibody. RESULTS: The median time of clinical follow-up was > 9 years. Eleven patients died of disease; the median time to death was 26 months. iMVD counts using antifactor VIII and anti-CD31 were tightly correlated (correlation coefficient = 0.89). S-phase fraction was higher in aneuploid tumors than in diploid tumors (mean, 12.4% vs. 4.3%; P = 0.01). Using univariate survival analyses, tumor size (stage classification pT1 vs. PT2; P = 0.01) and nuclear grade (P = 0.04) were associated with shortened survival. No statistically significant differences in survival were found for iMVD, MIB-1 score, DNA content, S-phase fraction, or p53 expression. Only two cases strongly expressed p53 protein; both tumors were of high nuclear grade. Using multivariate survival analyses, nuclear grade and tumor size were the only independent prognostic factors (best model P = 0.002). CONCLUSIONS: In this study, nuclear grade and tumor size were found to be independent predictors of survival in locally confined clear cell (conventional) RCC, as has been shown previously for locally confined RCC in general. MIB-1 score, iMVD counts, DNA content, S-phase fraction, and p53 expression did not contribute additional prognostic information.

Adult↗
PubMed1997

Renal cell carcinoma: current prognostic factors. Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC).

BACKGROUND: Renal cell carcinomas include several distinct entities with a range of biologic and clinical behavior from relatively indolent to extremely aggressive. Although conventional prognostic factors such as stage and grade are quite useful, other clinical, laboratory, and pathologic findings are now believed to have additional predictive value. METHODS: A review of the literature on the evaluation of prognostic factors in general and on the current status of prognostic factors in renal cell carcinoma in particular was undertaken. A working classification of prognostic factors, as recommended by the College of American Pathologists, was used. For clarity, the prognostic indicators were grouped according to whether each was a patient-related or tumor-related factor. RESULTS: Patient-related prognostic factors include symptomatic presentation, significant weight loss, poor performance status, anemia, hypercalcemia, elevated alkaline phosphatase and, perhaps, elevated serum ferritin. The most widely used tumor-related prognostic factors include stage, grade, and histologic type. Recently proposed biomarkers still under investigation include DNA content, as well as markers of cellular proliferation, apoptosis, and angiogenesis, among others. CONCLUSIONS: Current prognostic factors for renal cell carcinoma yield considerable information for assisting with patient management and predicting clinical outcome. Traditional prognostic factors remain the most valuable, even though a variety of other patient-related and tumor-related factors may significantly contribute to prognostic information. A number of recently described biomarkers show great promise but the current data are insufficient to recommend their use.

Aneuploidy↗
PubMed1997

Crossmatch-compatible platelets improve corrected count increments in patients who are refractory to randomly selected platelets.

BACKGROUND: HLA-matched platelets and crossmatch-compatible platelets are used to support thrombocytopenic patients who are refractory to randomly selected platelets. Data supporting the effectiveness of crossmatch-compatible platelets are limited, being essentially restricted to the subset of refractory patients previously shown to be alloimmunized. The authors' hospital does not test for alloimmunization. To determine the effectiveness of crossmatch-compatible platelets in an unselected group of refractory patients, the use of such platelets for all patients who are refractory to random-donor platelets was reviewed. STUDY DESIGN AND METHODS: All patients who received crossmatch-compatible platelets between January 1991 and May 1994 were retrospectively reviewed. All study patients were refractory to random-donor platelets, having two consecutive corrected count increments (CCIs) of < 10,000. A solid-phase red cell adherence method was used for platelet crossmatching, and CCI was used to monitor the effectiveness of each platelet transfusion. RESULTS: A total of 475 crossmatch-compatible platelet components were administered to 66 evaluable patients who were refractory to random-donor platelets. A significant improvement was found in the mean CCI when crossmatch-compatible platelets were compared with randomly selected platelets (p < 0.0001): an increase of 8000 +/- 6100 (mean +/- SD). In 59 percent (39/ 66) of the patients, the mean CCI improved to at least 7,500 and in 41 percent (27/66) to at least 10,000. If the 10 patients for whom crossmatch-compatible platelets were not identified are included, the mean CCI in 51 percent (37/76) of the refractory patients improved to at least 7,500; in 36 percent (27/76), it improved to at least 10,000. The effectiveness of crossmatch-compatible platelets did not decline with continued use. CONCLUSION: Crossmatch-compatible platelet components significantly improve the mean CCI for approximately one-half of patients who are refractory to random-donor platelets, even when the patients are not preselected for having alloimmunization to explain their refractory state.

Blood Grouping and Crossmatching↗
PubMed1997

Hodgkin's disease of the esophagus.

A 61-year-old man with acquired immunodeficiency syndrome (AIDS) sought care because of the onset of progressive dysphagia. He was found to have a perforated, fungating esophageal mass. The combined histologic and immunologic findings were diagnostic of Hodgkin's disease, nodular sclerosis type, lymphocyte-depleted variant, arising in the esophagus. The Reed-Sternberg cells and mononuclear variants were positive for Epstein-Barr virus (EBV) latent membrane protein (LMP1) and EBV RNA. Occasional small lymphoid cells were also positive for EBV RNA. Polymerase chain reaction studies demonstrated the presence of EBV type A without deletion of the EBV LMP1 gene. Other authors have reported an increased frequency of type B EBV and deletion of the EBV LMP1 gene in cases of human immunodeficiency virus-associated Hodgkin's disease. Hodgkin's disease arising in the esophagus is rare in immunocompetent patients. However, in the presence of AIDS, Hodgkin's disease should be considered in the differential diagnosis of patients with signs or symptoms of esophageal disease.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Prognostic factors in colorectal carcinomas.

Colorectal carcinoma remains a leading cause of cancer morbidity and mortality. Various clinical signs and pathologic factors have been shown to have a bearing on a patient's prognosis. Some of these factors, such as extent of disease (stage) and histologic grade, are generally accepted, while others, primarily biologic and molecular markers, have been proposed recently and remain controversial. The authors describe both more established and newly proposed variables, reviewing multivariate analyses to examine their relative importance. The recommendations of the Association of Directors of Anatomic and Surgical Pathology for the reporting of colorectal carcinomas are presented.

Biomarkers, Tumor↗
PubMed1996

Pregnancy-associated lymphomas. A clinicopathologic study.

BACKGROUND: The natural histories of Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHL) during pregnancy are not well understood. METHODS: All cases of HD and NHL diagnosed during pregnancy at Stanford University Medical Center since 1987 were reviewed and clinical follow-up was obtained. Various immunohistochemical studies and in situ hybridization for Epstein-Barr virus (EBV) encoded RNA were performed in a subset of cases. RESULTS: Seventeen cases of HD and 12 cases of NHL were accessioned (median age; 27 yrs). The HD cases were classified as 13 nodular sclerosis type, 3 mixed cellularity type, and 1 unclassified. Clinical follow-up revealed most of the patients had Stage II to III disease and were diagnosed on average at 22 weeks gestation. Most of the patients deferred therapy until after delivery and had no evidence of disease at the last follow-up except for one death with disease but not from it. NHL were classified according to the working formulation as high or intermediate grade lymphomas of various types, including both nodal and extranodal sites. Clinical follow-up revealed most had Stage II to IV disease and were diagnosed on average at 23 weeks gestation. Patients with HD tended to survive longer than those with NHL (raw mortality, P = 0.04). In situ hybridization failed to provide support for the presence of EBV in a subset of patients with NHL. CONCLUSIONS: The clinical behavior of these neoplasms during pregnancy does not appear to be significantly different from that outside of the setting of pregnancy. Treatment of selected HD patients apparently may be safely deferred until after delivery. Patients with NHL present with higher stage disease and have a poorer prognosis than those with HD.

Adolescent↗
PubMed1996

Editorial summary of the Pre-symposium workshop on the Contemporary Assessment of Technologies.

The following is the editor's summary of the Pre-symposium workshop on Contemporary Assessment of Technologies presented at the Symposium on Molecular Approaches to Laboratory Diagnosis at San Francisco in February 1995. This workshop was moderated by Dr Joel M. Palefsky, and Dr Michael P. Busch. We have briefly summarized the presentations by: (1) Dr Indira Hewlett of the Center for Biologics Evaluation and Research, Food and Drug Administration entitled 'Technology overview'; (2) Dr John J. Sninsky of Roche Molecular Systems Inc. entitled "Polymerase Chain Reaction'; (3) Dr Terrance Walker of Becton Dickinson Research Center entitled 'Strand Displacement Amplification'; (4) Dr Mickey Urdea of Chiron Corporation entitled 'bDNA assay' and (5) Dr Robert H. Singer of University of Massachussetts Medical Center entitled 'Image analysis of in situ hybridization'. Although it was not possible to list all the references to the primary literature, we have attempted to provide the key references as far as possible.

DNA↗
PubMed1996

Changes in blood coagulation during and following cardiopulmonary bypass: lack of correlation with clinical bleeding.

Although previous studies have documented a wide variety of derangements in laboratory measurements of blood coagulation and platelets during cardiopulmonary bypass, limited data are available concerning the magnitude of these changes and any association with excessive bleeding. To determine whether abnormalities in commonly available laboratory tests for the evaluation of coagulation, fibrinolysis and hemostasis correlate with postoperative blood loss and transfusion requirements as measures of clinical outcome, 47 consecutive patients undergoing coronary artery bypass grafting with hypothermic cardiopulmonary bypass (CPB) were studied prospectively at 12 time points before, during, and following CPB. Routine blood coagulation tests, coagulation factor levels (fibrinogen, V, VII, VIII, and IX) and fibrinolysis (FDP) became abnormal within 15 minutes after patients were placed on CPB, remained abnormal for the duration of CPB, and recovered at varying rates after discontinuation of CPB. Mean factor V levels declined by the greatest percentage, to 15% of normal, followed by factor VIII which decreased to 30%. Platelet counts declined to below 100 x 10(9)/L after the initiation of CPB and remained low in the postoperative period. Twenty-eight percent of patients had mediastinal output > or = 100 mL per hour during the immediate postoperative period, and were considered to be "bleeders." There were no clinically relevant differences in any of the laboratory measurements between patients with normal postoperative blood loss and those defined as bleeders. Thus, the absence of significant correlations between various laboratory measurements of hemostasis and actual postoperative bleeding indicates that these laboratory derangements are transient, are not predictive of clinically important hemostatic abnormalities, and should not be used in isolation to guide the use of blood components in these patients. Furthermore, although bleeders received more blood components, there was surprisingly little effect on the coagulation factor levels measured.

Adult↗
PubMed1996

Solitary fibrous tumor involving the renal capsule.

Solitary fibrous tumors are spindle-cell neoplasms that originally were described in the pleura but that can occur in a large variety of sites. We report a well-circumscribed tumor, apparently involving the renal capsule, clinically thought to be a renal-cell carcinoma or oncocytoma. It was composed of bland spindle-shaped cells with a patchy lymphoplasmacytic infiltrate, suggesting sarcomatoid renal-cell carcinoma, inflammatory myofibroblastic tumor, or solitary fibrous tumor; however, immunohistochemical stains were negative for keratin, alpha-smooth-muscle actin, and desmin but strongly positive for CD34. Ultrastructural examination revealed fibroblast-like cells without myofibroblastic or epithelial differentiation. The combined findings favor a diagnosis of a solitary fibrous tumor involving the renal capsule. To our knowledge, this lesion has not been reported in this location.

Antigens, CD34↗
PubMed1995

Adult renal epithelial neoplasms.

The consideration of adult renal epithelial neoplasms is no longer limited to renal adenocarcinoma, but also includes oncocytoma, chromophobe carcinoma, renal papillary neoplasms, collecting duct carcinoma, and neuroendocrine tumors. The recent application of classical and molecular cytogenetic techniques, particularly the studies of Kovacs and colleagues, has provided a biologic basis for this new classification. This review discusses the clinical and pathologic characteristics of these entities, with attention to differential diagnosis. Prognostic factors in renal adenocarcinoma are also discussed.

Adenocarcinoma↗
PubMed1994

Helicobacter pylori infection and gastric lymphoma.

BACKGROUND: Helicobacter pylori infection is a risk factor for gastric adenocarcinoma. We examined whether this infection is also a risk factor for primary gastric non-Hodgkin's lymphoma. METHODS: This nested case-control study involved two large cohorts (230,593 participants). Serum had been collected from cohort members and stored, and all subjects were followed for cancer. Thirty-three patients with gastric non-Hodgkin's lymphoma were identified, and each was matched to four controls according to cohort, age, sex, and date of serum collection. For comparison, 31 patients with nongastric non-Hodgkin's lymphoma from one of the cohorts were evaluated, each of whom had been previously matched to 2 controls. Pathological reports and specimens were reviewed to confirm the histologic type of the tumor. Serum samples from all subjects were tested for H. pylori IgG by an enzyme-linked immunosorbent assay. RESULTS: Thirty-three cases of gastric non-Hodgkin's lymphoma occurred a median of 14 years after serum collection. Patients with gastric lymphoma were significantly more likely than matched controls to have evidence of previous H. pylori infection (matched odds ratio, 6.3; 95 percent confidence interval, 2.0 to 19.9). The results were similar in both cohorts. Among the 31 patients with nongastric lymphoma, a median of six years had elapsed between serum collection and the development of disease. No association was found between nongastric non-Hodgkin's lymphoma and previous H. pylori infection (matched odds ratio, 1.2; 95 percent confidence interval, 0.5 to 3.0). CONCLUSIONS: Non-Hodgkin's lymphoma affecting the stomach, but not other sites, is associated with previous H. pylori infection. A causative role for the organism is plausible, but remains unproved.

Aged↗