Prospective comparison of the clinical impacts of heterogeneous vancomycin-intermediate methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-susceptible MRSA.

Although methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) strains with reduced susceptibility to vancomycin (RVS-MRSA; including vancomycin-intermediate S. aureus [VISA] and heterogeneous VISA [hVISA]) have been linked with vancomycin treatment failure, it is unclear whether they are more pathogenic than vancomycin-susceptible MRSA (VS-MRSA). We prospectively assessed patients with clinical MRSA isolates during a 10-month period to determine clinical status (infection versus colonization) and therapeutic outcome before correlating these findings with the results of detailed in vitro assessment of vancomycin susceptibility, including population analysis profile (PAP) testing. hVISA and VISA were defined by standard PAP criteria (area-under-the-curve ratio compared to that of the reference hVISA strain Mu3 [>or=0.9]) and routine CLSI criteria (vancomycin MIC, 4 to 8 microg/ml), respectively. Among the 117 patients assessed, 58 had RVS-MRSA isolates (56 hVISA and 2 VISA) and 59 had VS-MRSA isolates; the patient demographics and comorbidities were similar. RVS-MRSA was associated with a lower rate of infection than VS-MRSA (29/58 versus 46/59; P = 0.003), including a lower rate of bacteremia (3/58 versus 20/59, respectively; P < 0.001). The cure rates in RVS-MRSA and VS-MRSA groups were not statistically different (16/26 versus 31/42; P = 0.43), but the post hoc assessment of treatment regimes and study size made detailed conclusions difficult. The results of the macro method Etest correlated well with the PAP results (sensitivity, 98.3%, and specificity, 91.5%), but broth microdilution and our preliminary RVS-MRSA detection method correlated poorly. All isolates were susceptible to linezolid and daptomycin. These data suggest that detailed prospective laboratory identification of RVS-MRSA isolates may be of limited value and that, instead, such in vitro investigation should be reserved for isolates from patients who are failing appropriate anti-MRSA therapy.

Primitive erythropoiesis in early chick embryogenesis. II. Correlation between hemoglobin synthesis and the mitotic history.

Primitive erythroblasts in the circulating blood of the chick embryo continue to divide while synthesizing hemoglobin (Hb). Hb measurements on successive generations of erythroblasts show that there is a progressive increase in the Hb content of both interphase and metaphase cells. Furthermore, for any given embryo the Hb content of metaphase cells is always significantly greater than that of interphase cells. The distribution of Hb values for metaphase cells suggests that there are six Hb classes corresponding to the number of cell cycles in the proliferative phase. The location of erythroblasts in the cell cycle was determined by combining Feulgen cytophotometry with thymidine radioautography on the same cells. Measurements of the Hb content for erythroblasts in different compartments of the cell cycle (G1, S, G2, and M) show a progressive increase through the cycle. Thus, the amount of Hb per cell is a function of the number of cell divisions since the initiation of Hb synthesis and, to a lesser degree, the stage of the cell cycle. Earlier generations of erythroblasts synthesize Hb at a faster rate than the terminal generation. Several models have been proposed to explain these findings.

DNA content and DNA-based centromeric index of the 24 human chromosomes.

The chromosomes of two human males were identified by fluorescent banding, restained, and measured by scanning microscopy and computer analysis. The two variables, DNA content and DNA-based centromeric index, provided almost complete discrimination of chromosome types. Some chromosomes showed significant differences in DNA content between the men, and for one man two pairs of chromosomes showed significant differences between homologs.

Stress response protein (srp-27) determination in primary human breast carcinomas: clinical, histologic, and prognostic correlations.

Expression of an estrogen-regulated protein known as the 27,000-d heat-shock or stress-response protein (srp-27) was evaluated in human breast carcinomas and established breast cancer cell lines. Results obtained by Northern and Western blot analyses and immunohistochemical methods were concordant. Immunohistochemical assessment of srp-27 expression in 300 breast carcinomas (with median patient follow-up of 8 years) was performed. Twenty-six percent of lymph node-negative and 45% of lymph node-positive tumors were overexpressors. Univariate analysis demonstrated significant correlations between srp-27 overexpression and estrogen receptor (ER) content, pS2 protein expression, nodal metastases, advanced T stage, lymphatic/vascular invasion, and a shorter disease-free survival period (but not a shorter overall survival) for the study population as a whole. Regression tree analysis showed that srp-27 expression was an independent prognostic indicator for disease-free survival only in patients with one to three positive lymph nodes. The Cox proportional hazards model confirmed the independent prognostic significance of nodal involvement, T stage, and ER content but failed to recognize srp-27 overexpression as a significant independent parameter predictive of patient outcome in the patient population as a whole. The observed associations between srp-27 overexpression and more aggressive tumors suggest a biologic role for srp-27 in human breast carcinomas.

Tumor angiogenesis as a prognostic assay for invasive ductal breast carcinoma.

BACKGROUND: Tumor angiogenesis, as assayed by microvessel density, has been proposed as an independent prognostic marker for clinical outcome in breast cancer patients. PURPOSE: The present study evaluated the microvessel density assay and assessed its utility, alone and together with the evaluation of other tumor characteristics, in predicting outcome in patients with invasive ductal carcinomas. METHODS: In a blinded design, cases of invasive ductal carcinoma were selected from a registry containing the records of and tumor specimens from 386 breast cancer patients treated at the Massachusetts General Hospital from 1977 through 1982. After the exclusion of ineligible patients and inadequate specimens, 220 patients were included in the study; their median time of follow-up was 11.5 years. Half of these patients (n = 110) were positive for axillary lymph node metastases. Histologic sections of the tumors were stained immunocytochemically for factor VIII, a coagulation protein expressed by blood vessel endothelium, and for p53 protein. Independently, two analysts counted microvessels in three microscope fields selected from separate vascular regions of the tumor. Variability in microvessel scores between analysts and among different fields of the same tumor was summarized by the coefficient of variation. The kappa statistic tested for agreement between the analysts while correcting for chance agreement. The effects of tumor characteristics on metastasis-free survival and overall survival were tested univariately by the Harrington-Fleming rank test procedure. The effect of multiple factors on survival was tested under a Cox multivariate proportional hazards model. RESULTS: Microvessel count showed considerable variability between the two analysts and among regions within each tumor, with an overall concordance for tumor classification of 73%. Univariate analysis revealed no association between microvessel count and any other tumor or patient characteristic. Multivariate analysis indicated, for these patients, that nodal status and p53 staining predicted metastasis-free survival and that nodal status, estrogen receptor (ER) status and tumor grade predicted overall survival. CONCLUSIONS: Microvessel count showed much variation among different regions of each tumor. It did not predict metastasis-free survival or overall survival. Nodal status was the most powerful criterion to stratify these patients with invasive ductal carcinoma of the breast into different survival groups. Only ER status, tumor grade, and p53 staining had additional prognostic utility for these patients after they had been stratified by nodal status.

Accumulation of p53 tumor suppressor gene protein: an independent marker of prognosis in breast cancers.

BACKGROUND: Mutations of the tumor suppressor gene p53 have been identified in breast cancer cell lines, and some breast carcinomas are detectable by immunohistochemical assay because of p53 protein accumulation. PURPOSE: This study was designed to determine whether p53 protein accumulation in breast cancers correlates with p53 gene mutation, with survival, and with five pathobiologic factors associated with prognosis. METHODS: IgG1 monoclonal antibody to human p53 protein (PAb 1801) and immunohistochemical methods were used to detect p53 protein accumulation in archival formalin-fixed, paraffin-embedded, randomly selected carcinomas. We studied 295 invasive ductal carcinomas from the Massachusetts General Hospital; 151 were determined to be sporadic (not hereditary). We also studied 97 invasive ductal carcinomas--21 sporadic and 76 familial (hereditary)--from Creighton University. In addition, we examined 31 archival in situ carcinomas, 15 snap-frozen invasive ductal carcinomas, primary cell cultures from three benign breast tissue samples, and breast carcinoma cell lines MDA-MB-231 and MDA-MB-468. RESULTS: Nuclear p53 protein was observed in 16% of the 31 in situ carcinomas, 22% of the 172 sporadic carcinomas, 34% of the 50 tumors from patients with familial breast cancer, 52% of the 23 tumors from patients with the familial breast and ovarian cancer syndrome, and all three tumors from two patients with the Li-Fraumeni syndrome. There was complete concordance between p53 gene mutation and p53 protein accumulation in the 15 snap-frozen carcinomas and in both breast carcinoma cell lines. Statistically significant associations of p53 protein accumulation with estrogen receptor negativity and with high nuclear grade were found. There were statistically significant associations, independent of other prognostic factors, between p53 protein accumulation and metastasis-free and overall survival, for randomly accrued and for both sporadic and familial tumors. CONCLUSIONS: Immunohistochemically detected p53 protein accumulation was an independent marker of shortened survival and was seen more often in familial than in sporadic carcinomas. Our findings also suggest a correlation between p53 protein accumulation and p53 gene mutation.

Quantification by DNA-based cytophotometry of the 9q+/22q-chromosomal translocation associated with chronic myelogenous leukemia.

DNA-based cytophotometry was used to analyze metaphase chromosomes in four patients with chronic myelogenous leukemia. In three of these patients, both Philadelphia chromosome (Ph1)-positive and Ph1-negative cells were measured. On the basis of these three patients, the characteristic 9q+/22q- translocation of chronic myelogenous leukemia involves the net transfer of 0.325% of the autosomal genome; there is no evidence of net gain or loss of DNA (apart from duplication of the Ph1 chromosome in one patient), and no significant difference is found in the amount of DNA transferred in different patients. Significant differences are found among patients in the derived Chromosomes 9 and the Ph1 chromosomes and are ascribed to preexisting variations in the Ph1-negative cells of these patients. There is no evidence in these patients of any further cytogenetic lesion associated with chronic myelogenous leukemia.

Chromosomal DNA cytophotometry in 20q- nonspecific myeloid disorders.

DNA cytophotometry was used to quantify the chromosomal alterations in the bone marrow and blood of three patients with nonspecific myeloid disorders. All patients possessed a population of cells with a morphologically abnormal chromosome 20, del(20)(qll). In two of the patients, the abnormal chromosome 20 showed nearly identical DNA measurements with a net loss of 0.37% of the total autosomal DNA in one patient and 0.38% in the second. The third patient had a net loss of only 0.25% of the autosomal DNA. Analysis of the DNA content of the long arm and short arm of the abnormal No. 20 indicated that all three cases had chromosomal material added to the short arm (0.10 to 0.14% of the autosomal DNA). About 0.50% of the autosomal DNA was deleted from the long arm in two of the patients; only 0.35% of the autosomal DNA was deleted from the long arm in the third case. Within the limit of resolution, there is no evidence that the material lost has been translocated intact to another chromosome. The origin of the 20q- chromosome as the result of an incomplete pericentric inversion is suggested.

Centromeric copy number of chromosome 7 is strongly correlated with tumor grade and labeling index in human bladder cancer.

The relationship between interphase cytogenetics and tumor grade, stage, and proliferative activity was investigated in 27 transitional cell carcinomas of the urinary bladder. Using fluorescence in situ hybridization with chromosome-specific DNA probes, the copy number of pericentromeric sequences on chromosomes 7, 9, and 11 was detected within interphase nuclei in touch preparations from tumor biopsies. Monosomy of chromosome 9 was detected in 9 of 22 cases (41%), while tetrasomy for chromosomes 7 and 11 was detected in 10 of 26 (38%) and 6 of 23 (26%) cases, respectively. Copy number of chromosome 7 was the most highly correlated with increasing tumor grade (r2 = 0.616, P less than 0.001, Spearman rank correlation) or increasing pathological stage (r2 = 0.356, P less than 0.002). Copy number for chromosome 9 did not correlate with either grade or stage (P greater than 0.05). Tumor labeling index (LI) was determined after in vitro 5-bromodeoxyuridine incorporation, while proliferating cell nuclear antigen LI was determined immunohistochemically. Increasing LI by either method correlated with increasing copy number for all three chromosomes tested (r2 = 0.473, P less than 0.002 for 7; r2 = 0.384, P less than 0.01 for 11; and r2 = 0.316, P less than 0.05 for 9). Since high tumor grade, stage, and LI are all indicative of more aggressive tumor behavior and worse prognosis, these findings suggest that polysomy, especially for chromosome 7, may be highly predictive for bladder tumor aggressiveness.

Preliminary correlations of clinical outcome with in vitro chemosensitivity of second passage human breast cancer cells.

These studies describe the clinical correlations of 63 in vitro chemosensitivity assays on breast cancer cells after short-term monolayer culture. Forty-five of the assays were single agent correlations. Based on cut-off values determined empirically, the test accurately predicted resistance for 36 of 41 patients (88%) who did not respond to the drug. It also predicted sensitivity with a high degree of accuracy: 21 of 22 patients (95%) who responded to the drug tested had a sensitive assay. In five cases, two biopsies were evaluated from the same patient. Whenever assays were performed before and after treatment with a given drug, tumor cells from the second biopsy were more resistant in vitro if the patient failed on therapy. If the patient did not fail, but stopped therapy for other reasons, or if there was no intervening therapy with the tested drug, the two biopsies remained similar in drug sensitivity. These results suggest that in vitro chemosensitivity assays which accurately predict both sensitivity and resistance can be obtained with breast cancer cells after short-term culture and that further prospective trials are warranted.

Deoxyribonucleic acid cytometry helps identify parathyroid carcinomas.

It may be difficult in some patients with parathyroid tumors to distinguish between parathyroid carcinoma and parathyroid adenoma on the basis of clinical and histopathological findings. Patients initially diagnosed as having a parathyroid adenoma have subsequently occasionally developed metastases, and thereby their tumor was proven to be a carcinoma. To determine whether the nuclear DNA content would correlate with the clinical course and pathology of parathyroid tumors DNA cytometry was performed on parathyroid carcinomas (9 patients), histologically atypical adenomas (10 patients), adenomas associated with severe hypercalcemia [serum calcium, greater than or equal to 13.0 mg/dL (greater than or equal to 3.24 mmol/L); 11 patients], typical benign adenomas (11 patients), and incidentally removed normal parathyroid glands (6 patients). Sections were cut from the original paraffin-embedded surgical specimens and stained for nuclear DNA using the azure A Feulgen reaction. Nuclear DNA stain content was measured using an integrating image cytometer, and the results were plotted as histograms. Adjusted optical density (AOD) values were measured (in arbitrary units) to estimate the DNA content of whole nuclei in the specimens. The mean nuclear DNA content in the parathyroid carcinomas [24.6 +/- 2.1 (+/- SE) AOD] was significantly greater than that in the three groups of parathyroid adenomas (P less than 0.005, by unpaired t test) and in the normal parathyroid glands (P less than 0.0005). The mean nuclear DNA content in the atypical adenomas (15.8 +/- 1.6 AOD), profoundly hypercalcemic adenomas (16.8 +/- 1.3 AOD), and typical adenomas (16.0 +/- 1.1. AOD) were similar, and all were significantly greater than that in the normal parathyroid glands (11.5 +/- 0.7 AOD, P less than 0.05). Five distinct DNA histogram patterns were present in the parathyroid specimens from these 47 patients. Four of the 9 parathyroid carcinomas had an aneuploid DNA pattern, an abnormal pattern not found in any of the other groups; 2 of these tumors were originally diagnosed as atypical parathyroid adenomas. Both patients developed recurrent disease, and 1 died from a hepatic metastasis. Therefore, DNA cytometry provides valuable information in differentiating some parathyroid carcinomas from adenomas and diagnosing certain parathyroid carcinomas before the appearance of grossly invasive or metastatic tumor.

Correlation of bromodeoxyuridine (BRDU) labeling of breast carcinoma cells with mitotic figure content and tumor grade.

Tumor proliferation is inversely associated with survival in patients with breast carcinoma. Labeling of tumor cells with bromodeoxyuridine (BRDU) correlates highly with that seen with [3H]thymidine, the current "gold standard" for measuring tumor S-phase. However, the relationship of BRDU labeling to mitotic figure content and tumor grade remains incompletely defined. To determine this, we labeled 55 breast carcinomas with BRDU in vivo and correlated the results with mitotic figure content. The BRDU labeling index was the number of BRDU-positive cells/2,000 tumor cells, the mitotic figure index was the number of mitotic figures per 1,000 tumor cells, and the mitotic figure count was the number of mitotic figures per 10 high-powered fields. BRDU labeling was also correlated with tumor grade (Scarff-Bloom-Richardson). The BRDU labeling index correlated highly with the mitotic figure index (r = 0.814, p = 7.0 x 10(-14)), mitotic figure count (r = 0.725, p = 6.0 x 10(-10)), and tumor grade (r = 0.68, p = 1.1 x 10(-8)). The correlation of BRDU labeling with mitotic figure content was strong enough to suggest that a very carefully measured mitotic figure index provides an estimate of tumor growth fraction equivalent to the BRDU labeling index. Also, analysis of variance showed that the mitotic figure index was twice as precise as the mitotic figure count in estimating BRDU labeling, and thus was a more accurate measure of tumor proliferation. Moreover, measurements made by the mitotic figure index were as precise as those made by BRDU labeling. However, which method is optimal for estimating tumor proliferation rate remains unclear. Further studies are indicated.

Interactive display and analysis of data from bivariate flow cytometers.

An interactive computer program, SWELL, displayss and analyzes bivariate distributions generated by flow cytometers. SWELL is modular with options available via a menu, is written in Fortran, and utilizes a video color display system. Data are accumulated as a bivariate distribution that is transferred to the computer as a 64 x 64 matrix. For ease of visualization, matrices are displayed in pseudocolor. The distribution values are broken into eight ranges and each range is represented by a color. Each element of the matrix is then displayed in its assigned color. To allow pooling and comparison, distributions are aligned, edited, and standardized. Unknown samples are pooled or analyzed singly and compared to the normal pool by subtraction. Differences are displayed as pseudocolor matrices of sign, magnitude, or statistical magnitude in units of standard deviation. This latter display, scaled to tolerance limits, readily reveals regions of significant difference between normal and abnormal samples. Counts within such regions can be compared to diagnose samples automatically.

Strategies for choosing a deoxyribonucleic acid stain for flow cytometry of metaphase chromosomes.

Requirements for flow cytometry of metaphase chromosomes stained with three deoxyribonucleic acid (DNA)-specific fluorescent dyes--Hoechst 33258, Chromomycin A3, and ethidium bromide--are reviewed. Fluorescence properties of these three stains when bound to mitotic cells or to chromosomes in suspension are measured and compared with fluorescence properties when bound to DNA in solution. Conditions are given for high resolution flow cytometry of Chinese hamster chromosomes stained with each of the fluorophors, and histograms are presented that exhibit differences in relative peak position and area. Energy transfer fluorescence between two DNA stains is presented as a potentially useful new parameter for flow cytometry of chromosomes and is illustrated by fluorescence energy transfer from Chromomycin A3 to ethidium bromide when simultaneously bound to hamster mitotic cells.

Flow cytometry of human gynecologic specimens using log chromomycin A3 fluorescence and log 90 degrees light scatter.

Flow cytometry and electronic cell sorting are being investigated to screen gynecologic specimens for cervical neoplasia. Cellular DNA content is quantitated by Chromomycin A3 fluorescence and cell size is quantitated by 90 degrees light scatter; the logarithms of the measured intensities are used to produce a two parameter histogram. To determine the cell types responsible for signals in various histogram regions, systematic electronic cell sorting is performed. The sorted fractions are sedimented into microscope slides and stained by the Papanicolaou technique. The cells in each fraction are identified by conventional cytomorphologic criteria. Morphologic analysis of sorted cells reveals histogram regions corresponding to specific cell types. One very important region contains the highest concentration of signals from abnormal cells and is therefore the best region to analyze for specimen abnormality. However, because a significant number of signals in this region are from normal cells, specimens cannot be diagnosed by their analysis. Another important histogram region is composed primarily of signals from endocervical columnar and metaplastic cells. The presence of such cells is a good criterion for specimen adequacy, therefore analysis of signals in this region is essential to assess specimen adequacy for automatic screening.

Purification of the chromosomes of the Indian muntjac by flow sorting.

Metaphase chromosomes were isolated from a male Indian muntjac cell line, were stained with ethidium bromide and were analyzed by flow microfluorometry to establish a deoxyribonucleic acid (DNA)-based karyotype. Five major peaks were evident on the chromosomal DNA distribution corresponding to the five chromosome types in this species. The amount of DNA in each chromosome was confirmed by cytophotometric measurements of intact metaphase spreads. The five chromosome types were separated by flow sorting at rates up to several hundred chromosomes per second. The sorted chromosomes were identified by morphology and by Giemsa banding patterns. The automsomes, Numbers 1, 2 and 3, and the X + 3 composite chromosome were separated with a high degree of purity (90%). The centromere region of the X + 3 chromosome was fragile to mechanical shearing, and during isolation a small proportion of these chromosomes broke into four segiments: the long arm, the short arm, the short arm plus centromere and the centromere region. A large fraction of the constitutive heterochromatin of this species is present in the centromere region of the X + 3 chromosome and in the Y chromosome; these two regions possess similar amounts of DNA and therefore sort together. Chromosome flow sorting is rapid, reproducible and precise; it allows the collection of microgram quantities of purified chromosomes.

Ha-ras codon 12 mutation in papillary tumors of the urinary-bladder - a retrospective study.

This report concerns the retrospective examination of low grade, low stage (Ta/T1) bladder tumors for the Ha-ras codon 12 G-->T mutation. The patients studied had a minimum of 5 years follow-up and were grouped into 3 categories: (i) patients with no recurring tumors, (ii) patients with recurring Ta/T1 tumors and (iii) patients who subsequently developed high grade, high stage tumors. A heminested, non-isotopic, allele-specific polymerase chain reaction (PCR) amplification assay was used. The codon 12 G-->T mutation was found in 10/27 specimens from patients with non-recurring Ta/T1 tumors; in 11/27 initial and 12/23 recurring Ta/T1 tumors, and in 5/8 initial Ta/T1 lesions and 8/12 subsequently developed high grade/stage tumors. Although there was no correlation between disease recurrence and mutation, these results indicate that a relatively large proportion of patients with Ta/T1 tumors of the bladder have cells with the Ha-ras codon 12 G-->T substitution.

Correlation of Pneumocystis carinii cyst density with mortality in patients with acquired immunodeficiency syndrome and pneumocystis pneumonia.

Fifteen percent to 20% of patients with the acquired immunodeficiency syndrome and pneumocystis pneumonia do poorly despite early intervention. It is not known what distinguishes those who die, despite early intervention and aggressive therapy, from those who readily respond to therapy. We used image analysis to determine the relative abundance of cysts within aggregates of Pneumocystis carinii found in induced sputa (21 patients) and bronchoalveolar lavage fluid (14 patients) from 35 patients with pneumocystis pneumonia. We calculated a cyst density (number of cysts per area of aggregate) for each aggregate and a mean cyst density for all of the aggregates on the smear. Six patients died within 2 weeks of diagnosis; four of these six patients who had autopsies all had residual P carinii. The mean cyst density for those who died was 9.7 +/- 3.9 (range, 5 to 15 x 10(-3)). The 29 patients who survived beyond 2 weeks had a mean cyst density of 18.4 +/- 8.7 (range, 5 to 35 x 10(-3); P = .01). Mean cyst density was not influenced by the number of aggregates present in the smear, the variation in cyst density among aggregates in a smear, or the episode of pneumocystis pneumonia. Cyst density determinations alone should not be used to predict outcome for individuals with P carinii pneumonia until further study is completed. Nevertheless, the current study suggests that a low cyst density specimen, which may indirectly indicate a greater proportion of trophozoites compared with a high cyst density specimen, may be associated with an unfavorable outcome in acquired immunodeficiency syndrome-associated pneumocystis pneumonia.

Comparison of five histopathologic methods to assess cellular proliferation in transitional cell carcinoma of the urinary bladder.

Transitional cell carcinomas of the urinary bladder vary in their biologic potential, which may be correlated with the grade and stage of the tumor. Cellular proliferation may prove to be another measure of predicting tumor biologic potential. We have compared five different methods to assess proliferation in 26 tumors and correlated these results with tumor grade and stage. A portion of each tumor was incubated in vitro with bromodeoxyuridine (BrdUrd). For each tumor this was compared with at least three of the following four other markers of proliferation: mitotic count, silver-stained nucleolar organizer regions, immunohistochemical staining with Ki67, and proliferating cell nuclear antigen. Statistical correlations were seen between tumor grade and stage and these markers. There were strong correlations between the BrdUrd labeling index (LI) and both the Ki67 LI and proliferating cell nuclear antigen LI. The correlation between the BrdUrd LI and mitotic count was more tenuous; no significant correlation was found between BrdUrd LI and silver-stained nucleolar organizer region count. The correlation between these measurements of proliferation and tumor grade and stage was less strong. Our data suggest that cellular proliferation of transitional cell carcinomas can be reliably assessed with several different markers and that most of these markers can be correlated with tumor grade but not with stage.

In vivo measurement of breast cancer growth rate.

S-phase cells of 66 primary breast cancers were labeled in vivo by preoperative infusion of the thymidine analogue bromodeoxyuridine. A monoclonal antibody specific for DNA-incorporated bromodeoxyuridine was used to identify positive cells and compute a labeling index on histologic sections. The labeling index (the percentage of cells in S-phase) ranged from 0.1% to 23.9%; it correlated positively with poorly differentiated cancer, higher mitotic counts on routine histologic examination, and tumor size; and it correlated inversely with estrogen and progesterone receptors. The labeling index did not correlate with nodal involvement or ploidy. Of the 15 patients with a labeling index greater than 12%, three died and one had systemic disease after a median follow-up of 19 months. No other patients had recurrences. There were no clinical complications of bromodeoxyuridine infusion.