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T G Pretlow

Publications and source records attributed to T G Pretlow.

At least 91 records · Page 5Linked to original sources
PubMed1982

Glucose-6-phosphate dehydrogenase: a possible clinical indicator for prostatic carcinoma.

Any system of biochemical analysis that can be used to detect chemical differences between normal and malignant cells may add potentially valuable information to complement the histologic data which provide the practical definition of human prostatic carcinoma. A difference (P less than 0.0001) was observed in the levels of glucose-6-phosphate dehydrogenase (G-6-PD) activity in prostatic tissue with benign hyperplasia and prostatic carcinoma. Measured as a function of the amount of protein extracted from whole-tissue homogenates, the values for G-6-PD activity in prostatic carcinoma are almost four times those measured for benign prostatic hyperplasia. The degree of elevation of the activity of this enzyme suggests a correlation between enzymatic activity and clinical prognosticators, ie., histologic differentiation and clinical stage.

Adult↗
PubMed1982

Purification and transplantation of hepatocytes from livers of carcinogen-treated rats.

Young adult male F344 rats were given 90 ppm diethylnitrosamine in drinking water for 5 weeks. Cells were obtained in suspension from the livers of these animals by in situ perfusion of collagenase. Cells were separated in a 2.7-16% (wt/wt) continuous gradient of Ficoll in tissue culture medium in the Sorvall TZ-28 reorienting zonal rotor for 10 minutes at 4 degrees C with a centrifugal force of 12 X g at the sample-gradient interface (26 X g at the gradient-cushion interface). Up to half a billion liver cells were separated without exceeding the band capacity. In all experiments the purest fractions contained more than 90% hepatocytes. After centrifugation, 72.4 +/- 6.6% of the purified hepatocytes had histochemically demonstrable gamma-glutamyl transpeptidase (GGT). When purified hepatocytes were injected into the mesenteric veins of rats given a diet containing 0.02% (wt/wt) N-2-fluorenylacetamide for 7 days and subjected to partial hepatectomy, all rats that received these cells developed foci that exhibited histochemically demonstrable GGT. Hepatocytes with histochemically demonstrable GGT make up all or part of what previously has been referred to as "liver colony-forming units." With the TZ-28 reorienting zonal rotor, these cells can be purified in biochemically preparative quantities.

Animals↗
PubMed1982

Prostatic hexosaminidase activity in patients with benign prostatic hyperplasia and prostatic carcinoma.

Hexosaminidase activity in prostatic tissue has been compared in 15 patients with benign prostatic hyperplasia and 15 patients with prostatic carcinoma. The ratio of enzymatic activity for the two substrates tested (p-nitrophenyl-2-acetamido-2-deoxy-beta-D-glucopyranoside and p-nitrophenyl-2-acetamido-2-deoxy-beta-D-galactopyranoside) was not significantly different in the two groups of patients. The proportion of hexosaminidase represented by the B isozyme was not significantly different for the two groups of patients. Prostatic tissue hexosaminidase was greater (p = 0.0141) in carcinomatous prostates than in hyperplastic prostates.

Acetylglucosaminidase↗
PubMed1982

Decrease in creatine kinase in human prostatic carcinoma compared to benign prostatic hyperplasia.

Many previous studies have shown that a proportion of patients with carcinoma of the prostate have increased activity of the creatine kinase (E.C. 2.7.3.2) isoenzyme designated BB in sera from their peripheral blood. We have analyzed tissues from prostatic hyperplasia of 22 patients and from prostatic carcinoma of 23 additional patients. Prostatic carcinomas contain less (p less than 0.001) creatine kinase activity (units/g) than do prostates with benign prostatic hyperplasia. The facts that (a) histochemical studies that we performed confirmed the observation reported previously by others that creatine kinase activity is found primarily in the epithelial elements of hyperplastic prostates and prostatic carcinomas, (b) the carcinomas that we examined had, on the average, a somewhat larger epithelial component than the hyperplastic prostates that we examined, and (c) prostate cancer was found to contain less creatine kinase activity than hyperplastic prostates suggest that the epithelial cells in prostate cancers contain less creatine kinase activity per cell than do those from hyperplastic prostates. The BB form of creatine kinase accounts for 98% of the activity in prostatic carcinoma and in prostates without cancer. Creatine kinase has been discussed as a possible marker for prostatic carcinoma, and we had hoped that it might be useful for the assay of tumor burden. Our data suggest that, if creatine kinase is to be useful in the monitoring of tumor burden, it will be useful only in the contexts of particular patients studied longitudinally since the creatine kinase activity varies enormously among different prostatic carcinomas.

Aged↗
PubMed1981

Separation of two populations of cells with gamma-glutamyl transpeptidase from carcinogen-treated rat liver.

Noninbred Sprague-Dawley rats were maintained on a choline-deficient diet containing 0.05% ethionine. After 10-13 weeks, livers were dispersed with collagenase, lysozyme, collagenase and hyaluronidase. Pronase, or a selected batch of trypsin. The highest yield of cells with histochemically demonstrable gamma-glutamyl transpeptidase (GGT) was obtained with trypsin. After velocity sedimentation in an isokinetic gradient of Ficoll in tissue culture medium, two modal populations of cells with histochemically demonstrable GGT were observed. The first mode contained cells that were morphologically different from hepatocytes and that may be oval cells. The second, more rapidly sedimenting modal population of cells with GGT was morphologically similar to hepatocytes as assessed with Wright's stain; the location of this population in the gradient was the same as the location of cells with the appearance of hepatocytes that lacked iron and that had decreased glucose 6-phosphatase. In multiple experiments, the purest fractions contained 71.7 +/- 3.5% cells (mean +/- SD) with the appearance of hepatocytes with histochemically demonstrable GGT.

Animals↗
PubMed1981

Separation and characterization of the neoplastic and stromal elements of the R3230AC mammary adenocarcinoma.

The purification of the various types of cells in solid tumors is necessary for study of their biochemical and immunological functions. The R3230AC adenocarcinoma contains both a variety of stromal cells and well-differentiated neoplastic cells that possess many of the biosynthetic capabilities of normal rat mammary cells. Suspensions of cells from tumors weighing less than 1.2 g consisted of 70.4 +/- 7.2% (S.D.) malignant cells by morphology, 6.8 +/- 3.0% lymphocytes, 6.3 +/- 3.2% macrophages, 15.2 +/- 5.2% red blood cells, 0.8 +/- 0.5% granulocytes, and 0.5 +/- 0.6% unidentified cells. Sedimentation of the cells from the R3230AC tumor in a previously described isokinetic gradient resulted in a 5- to 6-fold purification of lymphocytes and macrophages. The modal fraction of malignant cells contained 95.3 +/- 2.9% malignant cells. Detection of alpha-lactalbumin by the direct peroxidase conjugate technique gave vacuolar staining of malignant cells, in contrast to the indirect and peroxidase-antiperoxidase techniques which stained ducts from normal lactating mammary gland and a wide variety of cells without vacuoles in the tumor. The best fixative for frozen sections, paraffin-embedded tissue, and cell suspensions was 50% ethanol-50% acetone. The suspensions of tumor cells contained 14.4 +/- 9.4% cells with histochemically demonstrable alpha-lactalbumin. Squamous metaplasia was commonly observed in tumors than lactating rats.

Animals↗
PubMed1980

Large-capacity separation of malignant cells and lymphocytes from the Furth mast cell tumor in a reorienting zonal rotor.

The Furth murine mastocytoma was adapted to the ascitic form and separated into fractions enriched with respect to lymphocytes and malignant cells by velocity sedimentation in the SZ-14 reorienting zonal rotor or in the isokinetic gradient. Lymphocytes were more highly purified (p less than 0.01) in the isokinetic gradient than in the zonal rotor, i.e., lymphocytes comprised 99.1% of the nucleated cells in the purest fraction from the isokinetic gradient and 80.1% of the nucleated cells in the purest fraction from the zonal rotor. Neoplastic mast cells were similarly purified by the two methods; they comprised 67.7 and 78.5% of the nucleated cells in the purest fractions from the isokinetic gradient and zonal rotor, respectively. Up to 160 million tumor cells can be purified in a single step with the reorienting zonal rotor, whereas 30 to 40 million cells per gradient approach the limit of the isokinetic gradient. After centrifugation in the zonal rotor, recovery was 85.6 +/- 12% (S.D.) of the cells layered over the gradient; and the separated tumor cells retained their ability to form tumors when transplanted into mice. The separation of large numbers of lymphocytes and malignant cells from the same tumor in the SZ-14 rotor should aid in the biochemical and immunological characterization of cancer.

Animals↗
PubMed1980

Tissue disaggregation of human renal cell carcinoma with further isopyknic and isokinetic gradient purification.

Five different human renal cell carcinomas were disaggregated with three combinations of enzymes. Significant tumor heterogeneity in response to the enzyme disaggregation was observed. A combination of collagenase (0.5 mg/ml) and trypsin (0.25%) was then used for routine disaggregation of 11 additional tumors. The viability of cells in suspension ranged between 63 and 98% with a mean viability of 83.2 +/- 10.7% (S.D.). The mean yield of total viable cells per g of tissue was 17.4 +/- 14.2 x 10(6). Tumor cells were further fractionated in isopyknic and isokinetic gradients. After isokinetic sedimentation, significant heterogeneity among tumors was seen, but lymphocytes were consistently located in Fraction 7 +/- 2, whereas tumor cells were predominantly in Fraction 22 +/- 1. Malignant epithelial cells were enriched to a 85.8 +/- 9.4% (range, 69.5 to 92.5%) purity by isokinetic gradient centrifugation. Lymphocytes could be successfully separated from tumor cells using an isopyknic gradient. Controlled rate freezing of cells provided material for repeated experiments while short-term tissue culture prior to cell separation increased the proportion of viable cells in the suspension. Disaggregation of human renal cell carcinoma and separation of malignant cells from tumor lymphocytes provides the foundation for characterizing these tumors biochemically and for analyzing hormonal responsiveness and the immunological characteristics of these tumors in vitro.

Adenocarcinoma↗
PubMed1980

The separation of human palatine tonsillar cells in the reorienting gradient zonal rotor: a large-capacity enrichment of plasma cells.

Velocity sedimentation by centrifugation in a previously described isokinetic gradient, at unit gravity, or with an elutriator has proved to be highly effective as a method for the enrichment of many kinds of cells. For many biochemical and immunological purposes, the available techniques for the separation of cells have been incapable of separating a sufficient number of cells. With a newly designed rotor, we have separated more than twenty-fold more human tonsillar cells that can be separated in the previously described isokinetic gradient. Without exceeding the band capacity, we separated 692 million tonsillar cells. Plasma cells were more than seven-fold enriched from human tonsillar cells. When 692 million tonsillar cells were separated in the rotor, the five most enriched, contiguous fractions of plasma cells contained 44 million cells. The most enriched fraction contained 27% plasma cells. We are not aware of any method for velocity sedimentation which will separate such large numbers of tonsillar cells.

Cell Count↗
PubMed1979

Hodgkin's cells and attached lymphocytes: a possible prognostic indicator in splenic tumor.

After the purification of Hodgkin's cells by a previously reported method from splenic tumor of 8 patients with Stages III or IV Hodgkin's disease, we have examined the proportions of Hodgkin's cells with attached lymphocytes. All patients were studied 3--5 years after staging laparotomy. Four patients had no recurrent disease; 3 had histologically confirmed recurrent disease; and 1 had clinically suspected recurrent disease (enlarged nodes) but has thus far refused further medical study and care. The proportion of purified Hodgkin's cells which had attached lymphocytes was consistently higher in the patients who were clinically free of disease. The possible biological significance of this observation is discussed briefly and would appear to warrant further investigation of this phenomenon in more patients with splenic tumor than are available to us.

Adolescent↗
PubMed1979

Urinary hexosaminidase in patients with lung carcinoma.

The specific activity of urinary hexosaminidase was determined in 58 patients with various histological types of lung carcinoma. Compared to an apparently healthy control population, 32/35 patients with widely disseminated disease showed elevated values and 18/23 patients with disease confined to the chest had normal hexosaminidase values. Detailed studies of 18 patients indicated that declining hexosaminidase values were associated with effective therapy, rising values generally accompanied progressive disease.

Adenocarcinoma↗
PubMed1979

Centrifugal elutriation (counterstreaming centrifugation) of cells.

Lindahl first described the separation of cells by velocity sedimentation utilizing a special technique (counterstreaming centrifugation) that was later modified slightly and renamed centrifugal elutriation. Centrifugal elutriation has been applied, with variable degrees of success, to the separation of hemopoietic cells, mouse tumor cells, testicular cells, and a variety of other specialized cells as well as cells in particular phases of the cell cycle. The capacity of the elutriator to separate large numbers of cells is its chief advantage. The purities of the separated cells have not been compared with the purities of cells separated by other methods in most cases; such comparisons would permit more sophisticated comparison of elutriation with other techniques for velocity sedimentation.

Animals↗
PubMed1979

Human colostral cells. I. Separation and characterization.

Analyses of the cells present in human colostrum obtained from fifty-four healthy donors during the first four days of lactation revealed that there were 3.3 x 10(6) (range 1.1 x 10(5)--1.2 x 10(7)) cells per ml of colostrum. Based on histochemical examinations, it was found that this population consisted of 30--47% macrophages, 40--60% polymorphonuclear leucocytes, 5.2--8.9% lymphocytes, and 1.3--2.8% colostral corpuscles; epithelial cells were rarely encountered. The identity of various cell types was confirmed by Wright's stain and by a series of histochemical techniques which disclosed the presence of non-specific esterase, peroxidase, and lipids. For further characterization, the different types of cells were separated by various methods, such as Ficoll-Hypaque density centrifugation, isokinetic centrifugation on a linear Ficoll gradient, adherence to glass or plastic, and phagocytosis of carbonyl iron. Immunohistochemical staining with FITC- and/or TRITC-labelled reagents to IgA, IgM, IgG, K- and lambda-chains, secretory component, lactoferrin, and alpha-lactalbumin were applied to unseparated as well as separated colostral cells. Polymorphonuclear leucocytes (staining for peroxidase) as well as macrophages and colostral corpuscles (staining for non-specific esterase) exhibited numerous intracellular vesicles that contained lipids as well as various combinations of milk proteins. Lymphoid cells did not stain with any of these reagents and plasma cells were not detected among the colostral cells. Individual phagocytic cells contained immunoglobulins of the IgA and IgM classes, both K and lambda light chains, secretory component, lactoferrin, and alpha-lactalbumin. The coincidental appearance of these proteins in single, phagocytic cells but not in lymphoid cells indicate that the cells acquired these proteins by ingestion from the environment. Markers commonly used for the identification of B lymphocytes (surface immunoglobulins) and T lymphocytes (receptors for sheep red blood cells) were unreliable for the analysis of colostral cells (unless accompanied by subsequent morphological characterization) because strong fluorescence was observed on the surface of many non-lymphoid cells and because numerous macrophages and colostral corpuscles formed rosettes with sheep red blood cells (SRBC). Lymphocytes, often found in association with colostral macrophages or corpuscles, were classified as T cells.

Cell Count↗