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R Gelman

Publications and source records attributed to R Gelman.

At least 73 records · Page 4Linked to original sources
PubMed1991

The use of radionuclide imaging in the evaluation of suspected biliary damage during laparoscopic cholecystectomy.

Laparoscopic cholecystectomy offers a reliable and effective alternative to the standard operative cholecystectomy with reduced morbidity and patient recovery time. We report three cases in which radionuclide hepatobiliary imaging was utilized to evaluate the integrity of the extrahepatic biliary ducts following suspected biliary damage during the procedure, documenting bile leakage in two of the patients.

Adult↗
PubMed1991

Factors predicting for response, time to treatment failure, and survival in women with metastatic breast cancer treated with DAVTH: a prospective Eastern Cooperative Oncology Group study.

Six hundred twenty-four women with metastatic breast cancer were entered on Eastern Cooperative Oncology Group (ECOG) study EST 2181. Patients were treated with mitolactol, doxorubicin, vincristine (DAV), tamoxifen, and fluoxymesterone (DAVTH). Nine patients were canceled, and 114 were ineligible (half because of concomitant diseases). Among the 501 eligible patients, the overall response rate was 54% (14% complete response and 5% not assessable). The median time to treatment failure (TTF) was 9.0 months, and the median survival was 20.9 months. Multivariate models were fit on a randomly chosen half of the eligible cases and then verified on the other half. About half of the variables that were significant in the models remained significant in the verification data set. In the verification data set the variables that remained significantly associated with lower probability of response were three or more organ sites of disease and lack of nodal metastases; the variables associated with a significantly shorter TTF were liver metastases, estrogen receptor (ER)-negativity, and prior adjuvant therapy. The variables associated with significantly shorter survival were liver metastases, ER negativity, three or more organ sites of disease, and prior adjuvant chemotherapy. None of the variables in the data set had a significant influence on toxicity. The 125 patients aged over 65 years did not have worse toxicity or worse prognosis than younger patients. Ineligible patients had significantly less response but virtually identical TTF curves, survival curves, and toxicities. Therefore, patient discriminants are of paramount importance in predicting the outcome of treatment. Many of the current criteria for eligibility for entry on study may not be justified.

Adenocarcinoma↗
PubMed1991

Diaphragmatic rupture due to blunt trauma: sensitivity of plain chest radiographs.

Preoperative diagnosis of diaphragmatic rupture caused by blunt injury is often difficult because of serious concurrent injuries, a lack of specific clinical signs, and simultaneous lung disease that may mask or mimic the diagnosis radiologically. Previous reports have suggested that a preoperative diagnosis is established on the basis of chest radiographs in only one third of patients. In order to assess the value of chest radiographs and other imaging techniques in diagnosing traumatic rupture of the diaphragm, we retrospectively reviewed all preoperative diagnostic imaging performed in 50 patients with surgically proved hemidiaphragmatic rupture due to blunt trauma. Chest radiographs were diagnostic in 20 (46%) of 44 patients with left-sided rupture and were considered suspicious enough to warrant further diagnostic studies in an additional eight patients (18%). Five patients with initially normal findings on chest radiographs had diagnostic findings on delayed chest radiographs. Chest radiographs were strongly suggestive in only one (17%) of six patients with right-sided hemidiaphragmatic rupture. CT was diagnostic for diaphragmatic rupture in only one (14%) of seven instances in which it was performed. MR was diagnostic in both patients in whom it was performed. Our experience indicates that chest radiographs obtained at admission and repeated soon after are more valuable in suggesting the diagnosis of traumatic rupture of the diaphragm than previously reported, particularly in the more frequent, left-sided injuries. This increased sensitivity may be due to a greater level of suspicion maintained in a trauma referral center in which this injury is not uncommon.

Adolescent↗
PubMed1990

Nuclear binding of the estrogen receptor: a potential predictor for hormone response in metastatic breast cancer.

We have previously described an in vitro immunohistochemical test employing anti-receptor antibodies, for demonstrating the nuclear binding characteristics of estrogen receptors (ER) in breast carcinomas. Based on a retrospective analysis of twenty-five patients with estrogen receptor-positive (ER+) breast cancer who were treated with hormone therapy and whose clinical responses were evaluable, we were able to demonstrate that this test may be valuable to predict which, among the ER+ tumors (whether or not they are progesterone receptor positive, PR+), are likely to respond to hormone therapy and which may fail. While tumors in which ER exhibited abnormalities in nuclear binding behavior (ligand-independent nuclear binding or no nuclear binding) failed hormone therapy (16 out of 19 patients), those in which nuclear binding of ER appeared normal (ligand-dependent) in the in vitro test, responded to hormone therapy (5/6 patients). While our previous report dealt with the procedural details, specificity of the reagents, and the design of the study, this report addresses the clinical aspects of this study and response correlation.

Biomarkers, Tumor↗
PubMed1990

Numerical abstraction by human infants.

Across several experiments, 6- to 8-month-old human infants were found to detect numerical correspondences between sets of entities presented in different sensory modalities and bearing no natural relation to one another. At the basis of this ability, we argue, is a sensitivity to numerosity, an abstract property of collections of objects and events. Our findings provide evidence that the emergence of the earliest numerical abilities does not depend upon the development of language or complex actions, or upon cultural experience with number.

Attention↗
PubMed1990

Early breast cancer: predictors of breast recurrence for patients treated with conservative surgery and radiation therapy.

The identification of factors associated with breast recurrence following conservative surgery (CS) and radiation therapy (RT) is of potential use in refining patient selection criteria and treatment technique. In an attempt to define such factors we examined the relationship between various clinical, pathologic and treatment characteristics and the likelihood of breast recurrence in 783 patients with clinical stage I or II breast cancer treated between July 1968 and December 1982. Treatment consisted of complete gross excision of the primary tumor and RT to a total dose of at least 60 Gy to the primary site. During this period, pre-treatment mammograms and detailed histologic assessment of the margins of resection were not routinely performed. Median follow-up for surviving patients was 80 months. Thirteen patients (1.6%) were lost to follow-up. Ninety-one patients (12%) have developed a breast recurrence, corresponding to 5- and 10-year actuarial rates of 10 and 18%, respectively. The major feature associated with breast recurrence was the presence of an "extensive intraductal component" (EIC+). An EIC+ tumor was seen in 28% of evaluable cases with infiltrating ductal carcinoma and accounted for 60% of breast recurrences. Forty-three of 166 patients (26%) with EIC+ tumors developed a breast recurrence compared with 29 of 418 patients (7%) without an EIC (EIC-) (p = 0.0001). The 5-year actuarial rates of breast relapse were 24 and 6%, respectively (p = 0.0001). Very young age (defined as 34 years of age or younger) was also a significant factor associated with the risk of breast recurrence. Very young patients comprised 8% of the patient population and accounted for 16% of breast recurrences. Fifteen of 61 very young patients (25%) developed a breast recurrence compared with 76 of 722 older patients (11%) (p = 0.001). The corresponding 5-year actuarial rates of breast recurrence were 21 and 9% (p = 0.005). None of the other clinical or pathological factors examined by univariate analysis were significantly correlated with recurrence in the breast. A multivariate model of site of first failure (polychotomous logistic regression) also showed that EIC+ tumors and very young age were the main factors associated with a high relative risk of breast recurrence. We conclude that EIC+ tumors and very young age are associated with a high risk of breast recurrence for patients treated with limited excision prior to RT.

Actuarial Analysis↗
PubMed1990

Genetics of survival in mice: subregions of the major histocompatibility complex.

In this study of murine survival, 422 F1 hybrids between DBA/2J (D2) female mice and C57BL/10 (B10) background H-2 congenic male mice (11 strains), 88 F1 hybrids between B10 female mice and B10 background H-2 congenic male mice (3 strains), and 532 control mice from the 11 parental B10 background H-2 congenic mice were bred over a period of 2 yr. Toward the end of the breeding period there was documentation of Sendai infection in the mouse rooms. All analyses were done separately for the two sexes. Although it did not appear that an unusually high number of mice died during the time the colony was infected with Sendai, there was a highly significant tendency for mice who were younger at the time of the Sendai infection to have shorter survival than mice who were older at that time point. The effect of birth date on survival was approximately as significant as the effect of strain on survival. Hence all analyses of genetic effects on survival were either done within subsets of mice born in the same quarter of a particular year or else included date of birth variables in survival models. Of the 18 possible comparisons of pairs of strains which overlapped in birth dates and differed only in the D end of H-2, five were associated with highly significant survival differences. Of the 11 pairs of strains which overlapped in birth date and differed only in the K end of H-2, none was associated with significant survival differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1990

The presence of an extensive intraductal component following a limited excision correlates with prominent residual disease in the remainder of the breast.

Previous studies of patients with infiltrating ductal breast cancer treated with conservative surgery (ie, limited excision) and radiotherapy have indicated that the presence of an extensive intraductal component (EIC) in the excision specimen is highly associated with subsequent breast recurrence. The reason for this association is not clear, but possible explanations include the presence of more extensive disease in the breast or increased radiation resistance among tumors with an EIC (EIC+) compared with those without (EIC-) tumors. To investigate this association further, we related the presence or absence of an EIC in the primary tumors of 214 women who underwent mastectomy to the likelihood of finding additional foci of cancer in their mastectomy specimens using a correlated pathologic-radiologic mapping technique. Primary tumors that were EIC+ were significantly more likely to have carcinoma in the remainder of the breast than those which were EIC--(74% v 42%; P = .00001). This difference was primarily due to the presence of residual intraductal carcinoma. Seventy-one percent of EIC+ patients had residual intraductal carcinoma compared with 28% of EIC-patients (P less than .00001). In particular, 44% of EIC+ patients had "prominent" residual intraductal carcinoma compared with 3% of EIC-patients (P less than .00001). We conclude that patients whose tumors contain an EIC more frequently have a large subclinical tumor burden in the remainder of the breast compared with patients whose tumors do not contain an EIC. This observation may explain the association between EIC and subsequent breast recurrence when patients are treated with a limited excision before radiotherapy.

Breast↗
PubMed1990

Improved methodology for analyzing local and distant recurrence.

Studies of radiation therapy and/or surgery in the treatment of cancer frequently use actuarial methods to estimate curves of time to local failure and compare two such curves with statistical methods originally developed for survival data. In such analyses, patients who fail first in distant sites or die before local failure are considered censored for time to local failure. While the arithmetic of these calculations is usually correct, the interpretation of the results is almost universally incorrect. For example, an actuarial Kaplan-Meier curve of time to breast recurrence after breast conserving treatment consistently overestimates the percentage of patients who would benefit from a subsequent mastectomy. Actuarial methods require the assumption that time to local failure and time to distant failure are statistically independent. For most human malignancies this is not a reasonable assumption, since there are always some patient subgroups at high risk of both local and distant failure and some patient subgroups at low risk for either type of failure. Without the assumption of independence, the time to local failure distribution is not well defined. The basic problem is that estimating time to local failure falls into the category of analyzing "competing risks," since the various causes of failure are competing for the same patient. For this reason, the effects of a particular treatment on local failure cannot be assessed separately from its effects on distant failure. This report explains the concepts of statistical independence, nonidentifiability, and competing risks and illustrates the pitfalls of using actuarial methods to assess local tumor control.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1989

Spontaneous mutation rates of tumorigenic and nontumorigenic Chinese hamster embryo fibroblast cell lines.

The genomic stability of a series of nontumorigenic, tumorigenic, and tumor-derived Chinese hamster embryo fibroblastic (CHEF) cell lines was compared by examining their rates of spontaneous mutation at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus, using thioguanine resistance for selection of mutants. The spontaneous mutation rates were 1.1 x 10(-6) mutations/cell/generation in the non-tumor-forming CHEF/18 cell line and 4.9 x 10(-6) in the tumorigenic CHEF/16 cells. Three tumorigenic and tumor-derived CHEF cell lines derived from CHEF/18 (J132 3-2 T3L, focus 2, focus 3) and two lines (16-2 Tuk 4 and 204 Bu50 Tuk 2) derived from CHEF/16 were chosen on the basis of their karyotypes, which demonstrated a considerable level of chromosomal rearrangement. Mutation rates of four of these five lines ranged from 1.2 x 10(-6) to 8.9 x 10(-6) mutations per cell per generation. Only the fifth line, 16-2 Tuk 4, showed a significantly elevated rate of mutation as compared with the nontumorigenic CHEF/18 cell line. Thus, we have found no simple correlation between spontaneous mutation rate and the malignant phenotype, and we conclude that mutation rate per se is not a sensitive index of malignancy. In addition, we have compared three methods of calculating mutation rate and find that they rank the cell lines in the same order, but each stresses a different aspect of the distribution and therefore produces different estimates of the mutation rate.

Animals↗
PubMed1989

Results of the flow cytometry ACTG quality control program: analysis and findings.

The AIDS Clinical Trial Group's (ACTG) Immunology Committee was charged with initiating a quality control program for all laboratories participating in the ACTG program reporting flow cytometry data. Forty-one laboratories were evaluated. This report defines the goals of this program and the subsequent findings after 19 send-outs were made. Both HIV positive volunteer donors and normal age-matched donors were used. Sample sets included both heparin and EDTA anticoagulated bloods. Laboratories were asked to report hematologic parameters as well as flow cytometry data both in percentages and absolute numbers. Results were evaluated using nonparametric statistical analysis. Robust CVs and interquartile ranges were used to define the performance of individual laboratories for each CD subset analyzed. Intralaboratory reproducibility was analyzed by paired sample sets. All laboratories were found to be able to define normal samples as normal. Seventy-five percent of the laboratories were able to define abnormal samples as abnormal. Twenty-five percent could not identify two abnormal samples as abnormal. Forty percent of the labs were found unable to reproduce paired samples within an absolute of +/- 5%. EDTA was found slightly superior to heparin in bloods evaluated by flow cytometry within 30 hr of collection. The analysis of specific histograms, questionnaires, and data analysis led to a specific set of recommendations for performance of flow cytometry studies.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Premenopausal breast cancer patients treated with conservative surgery, radiotherapy and adjuvant chemotherapy have a low risk of local failure.

The use of adjuvant chemotherapy in premenopausal breast cancer patients with positive nodes is now routine, but the optimal local treatment of these patients is uncertain. To determine the effect of adjuvant chemotherapy on the likelihood of local recurrence as the first site of failure in premenopausal patients treated with conservative surgery (CS) and radiotherapy (RT), we examined the outcome of 74 patients treated with CS, RT, and adjuvant chemotherapy and compared it to the outcome in 192 patients treated with CS and RT alone. Adjuvant chemotherapy consisted of four or more cycles of either a doxorubicin-containing regimen or cyclophosphamide, methotrexate, and 5-fluorouracil. All patients were less than 50 years old, had UICC-AJCC Stage I or II breast cancer treated between 1968 and 1981, had gross excision of the primary tumor, and had a total radiation dose to the primary tumor bed of greater than or equal to 6000 cGy. Factors predicting for local recurrence, such as extensive intraductal carcinoma and age less than 35, were equivalent in the two groups. Women treated with adjuvant chemotherapy had significantly worse T- and N-stages than women treated with conservative surgery and radiotherapy alone: 61% versus 36% had T2 tumors (p = 0.0003), 34% versus 6% had clinically positive nodes (p less than 0.0001), and 97% versus 4% had pathologically positive nodes (p less than 0.0001). Despite the poorer prognosis of patients treated with adjuvant chemotherapy, within 5 years of diagnosis, 4% of patients who received adjuvant chemotherapy had their initial relapse in the breast and 24% had initial failure elsewhere, compared with 15% local failure first and 14% failure elsewhere first for those treated without chemotherapy (p = 0.01). We conclude that premenopausal patients with positive nodes treated with combined modality therapy (conservative surgery, radiation therapy, and adjuvant chemotherapy) have a low risk of local recurrence as a first site of failure. These results suggest a possible interaction between radiation therapy and chemotherapy in their effects on local tumor control.

Adult↗
PubMed1989

The predictors of distant relapse following conservative surgery and radiotherapy for early breast cancer are similar to those following mastectomy.

Although previous studies have indicated that the predictors of local recurrence following conservative surgery (CS) and radiotherapy (RT) are not the same as those following mastectomy, it remains unclear whether the predictors of distant relapse differ by local treatment modality. Clinical and pathologic features predictive of distant relapse for patients treated with mastectomy have been well established and include lymph node involvement, histologic grade, and peritumoral lymphatic vessel invasion (LVI). To study the influence of these and other factors on the rate of distant relapse in patients treated with CS and RT, we have identified a group of 438 patients treated between 1968 and 1981 who met the following criteria: primary tumor size less than or equal to 5 cm, excision of the primary tumor, infiltrating ductal carcinoma as the most aggressive histologic subtype, histology evaluable for the presence of an extensive intraductal component, and a dose to the primary site greater than or equal to 60 Gy. Estrogen receptor status was available in 58% of cases, 76% had an axillary dissection, and 23% were treated with adjuvant chemotherapy. With a median follow-up of 89 months, 107 patients (24%) developed a distant relapse. The 5-year actuarial freedom from distant relapse (FDR) was 80%. Stepdown Cox proportional hazards regression analysis identified several factors associated with a significantly (p less than 0.01) increased risk for distant relapse: positive lymph nodes, histologic grade, necrosis, and lymphatic vessel invasion. The magnitude of each effect was then examined with a lifetable calculation. Five-year freedom from distant relapse was 86% for the node-negative subgroup, 78% for patients with one to three positive nodes, and 45% for patients with four or more positive nodes. For histologic grades I, II, and III, 5-year freedom from distant relapse was 96%, 97%, and 75%, respectively. For necrosis scored as absent, scant, moderate, or marked, 5-year freedom from distant relapse was 90%, 78%, 77%, and 66%, respectively. For lymphatic vessel invasion scored as absent or present, 5-year freedom from distant relapse was 85% and 63%, respectively. We conclude that the clinico-pathologic predictors for distant relapse following conservative surgery and radiotherapy appear to be the same as those following mastectomy. This observation is consistent with the notion that distant relapse is caused by the presence of micrometastases at the time of initial patient sentation and is not greatly influenced by selection of local treatment.

Breast Neoplasms↗