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Biomedical subjects

J Gil

Publications and source records attributed to J Gil.

At least 19 recordsLinked to original sources
PubMed1992

Quantitative perimeter and area measurements of digital images.

Quantitative estimations of perimeter and area from digitized video images, and the application of these features in morphometry, are discussed. Estimations from manual tracings via interactive peripherals and from chain codes are addressed. Topics discussed are calibration, determination of vertical and horizontal pixel resolution, effects of tracing jitter, and for chain codes, the spatial quantization scheme representation of the digital contour. Finally, new perimeter estimators for 4-connected and 8-connected chain codes for non-unity pixel aspect ratio are presented with simulation results.

Animals↗
PubMed1992

Tumor cytostasis mediated by a monoclonal IgM antibody promoting adhesion between macrophages and tumor cells. Evidence for a lectin-like behavior.

We have shown previously that an IgM mAb (A10) recognizing Ehrlich tumor (ET) cell surface carbohydrates, inhibits in vivo ET growth by a macrophage-dependent mechanism. The inhibition mechanism involving both IgM and macrophages was unclear because receptors for IgM on macrophages are controversial and another monoclonal IgM (E1), also recognizing ET cell surface carbohydrates, was completely unable to show any protective effect. Here we show that A10, but not E1, was able to promote adhesion between macrophages and ET cells by a receptor for IgM-independent mechanism. Immunofluorescence studies showed that A10, but not E1, did react with macrophages if these cells were preincubated with a source of Ag spontaneously released from ET cells. This Ag release appeared to be required for A10-mediated adhesion, because adhesion was not obtained when ET cells fixed with paraformaldehyde were used. Cytostasis studies performed with macrophages stimulated with L-929 conditioned medium and ET cells showed that A10, but not E1 nor unrelated IgM, was able to inhibit ET cell proliferation in vitro by a mechanism involving cell contact between both cell populations. Therefore, IgM inhibition of ET growth, both in vivo and in vitro, could be explained by a lectin-like mechanism, where IgM, recognizing Ag of tumor origin, bridges macrophages to tumor cells.

Animals↗
PubMed1992

Differential diagnosis of borderline and invasive serous cystadenocarcinomas of the ovary by computerized interactive morphometric analysis of nuclear features.

Whether borderline serous tumors of the ovary can be differentiated from invasive serous cystadenocarcinomas by morphometric analysis of nuclear features of the neoplastic epithelium was examined. Multiple descriptors extracted from nuclear tracings and intranuclear gray-level analysis of argyrophilic nucleolar organizer regions were evaluated in 11 borderline and 18 invasive tumors using computerized interactive morphometric analysis. These descriptors included: nuclear area and perimeter; number, area, and perimeter of argyrophilic nucleolar organizer regions; standard deviations of these findings; and a size distribution of nuclear areas in discrete classes. Multivariate statistical analysis showed the internal consistency of the two groups in terms of physical descriptors and the discriminating value of the parameters of nuclear size and pleomorphism (independently of nucleolar organizer region parameters). The results indicated that interactive morphometric analysis of nuclear features, combined with appropriate statistical methods, could be used to distinguish between these tumors.

Cell Nucleus↗
PubMed1992

Cell contour extraction on multi-threshold images.

A procedure for the extraction of cell and nuclear contours from digital images is presented. The procedure is simple and suitable for efficient implementation in an interactive environment where the user selects a region of interest containing the cell to be segmented. Segmentation is facilitated by multi-thresholding where the threshold values are determined by an iterative algorithm using the mean square error criteria to cluster the image pixel values. Edges are detected on the threshold images by employing a binary morphological filter and the desired contours are selected by considering closed contours in the edge image. The cell region is first extracted by performing segmentation, edge detection and contour extraction on the region of interest. The nuclear region is subsequently extracted by reapplication of the algorithms within the extracted cell region. Segmentation examples are presented.

Algorithms↗
PubMed1992

Two types of endometrial papillary neoplasm. A morphometric study.

Fourteen cases of Papillary Endometrial Carcinoma (EC) were analyzed by Interactive Computerized Morphometry. Seven cases were diagnosed as well differentiated adenocarcinomas with papillary features (PF) and belonged to a group of EC with associated adenomatous hyperplasia (AH). Seven cases were diagnosed as uterine papillary serous carcinomas (PA) and belonged to a group of EC without associated AH. Two morphometric procedures were used. DRAW for the characterization of individual nuclei (area, perimeter, chord) and NU-MEAS for tissue architectural features (crowding and stratification). Using a stepwise discriminant multifactorial analysis, both methods proved to be accurate for the two diagnostic categories, as shown by the 100% posterior probabilities and by the two diagnostic categories, as shown by the 100% posterior probabilities and by the distances between group means. A doubtful case was analyzed and classified using a K-nearest neighbor procedure, compared to the individual case in the database. The distinction between the two types of papillary EC is important for the differential diagnosis of the two lesions. Well differentiated adenocarcinoma with papillary features is seen usually in the context of a well-differentiated adenocarcinoma, in a group of patients known to have estrogen-related less aggressive tumors. Uterine papillary serous carcinoma was described to have a biological behavior similar to that of papillary ovarian carcinoma and is encountered in a group of patients with more invasive and less differentiated EC2. Computerized interactive morphometry is a valuable method to use for the accuracy of this differential diagnosis in doubtful cases.

Adenocarcinoma↗
PubMed1992

Measurement of mechanical forces acting on the area pellucida of the early chick embryo.

We have designed a method for measuring mechanical forces acting on the area pellucida of the chick embryo between stages 1 to 5 of HAMBURGER and HAMILTON (1951). The coordinates of several points on the outline of the area pellucida were used as input, from which a computer program measured the changes in the position of similar points to produce a table of values which, we argue, reflect mechanical forces in the embryo. The results obtained are shown to be reproducible between embryos. The computer program and the measurements obtained were then used to predict the behaviour of surgical incisions made in the area pellucida, using the tables obtained from direct measurements of embryos and the coordinates of various points on the surface of the operated embryos. This procedure was applied to embryos cultured by the method of NEW (1955) and in-ovo. It was found that in those embryos cultured by EWS technique the computer predictions correspond very closely to shape measurements made directly from embryos. However, the correspondence is less close when applied to embryos in-ovo.

Animals↗
PubMed1992

A novel system for the culture of human lung: lung development and the response to injury.

Existing methods of fetal lung organ culture are complicated and require special skills. With the use of a polyester-based plastic sheet, we have developed a simpler human fetal lung organ culture that is viable for 6 wk. This novel method permits the study of growth and differentiation, pulmonary surfactant secretion, and the response of human lung tissue to injury in vitro. Lung tissues, obtained from human fetuses ranging in gestational age from 14 to 18 wk, were cultured on the polyester sheet in Dulbecco's modified Eagle medium supplemented with 15% fetal calf serum and gentamicin. Microscopic study of the fetal lung before culturing revealed round epithelial tubules, lined by glycogen-rich columnar cells and a thick cellular interstitium. After 1 wk in culture, morphological examination showed the development and expansion of alveolar saccules and thinning of the interstitium; type I and II pneumocytes as well as fibroblasts and myofibroblasts were present. Lipid analysis of the tissues, 2 wk after the initiation of the culture, demonstrated a high percentage of dipalmitoyl phosphatidylcholine characteristic of pulmonary surfactant. Treatment of the organ culture with asbestos fibers induced type II cell hyperplasia, increased numbers of collagen fiber bundles within the interstitium, and the accumulation of multi-lamellated surfactant material within the alveolar lumens. We conclude that this organ culture system is suitable for studying lung growth, development, and injury in human tissue.

Asbestos↗
PubMed1992

Pituitary extract causes aggregation and differentiation of rat mammary tumor MTW9/Pl cells.

Alkaline pituitary extracts (PE) of the mammosomatotropic tumor MtTW10 differentiated cultured PRL-independent rat mammary tumor cells MTW9/Pl. Within 24 h, MTW9 cells growing in suspension began to aggregate and adhere to the plastic dish. Cultured dispersed MTW9 cells were undifferentiated, but PE treatment resulted in organoid aggregates that exhibited glandular luminal structures and periodic acid-Schiff-positive material consistent with basement membrane formation. Morphometric examination of organoids demonstrated a reduction in nuclear and cell perimeters compared to those of untreated cells. Electron microscopy showed that the treatment resulted in polarization, nuclear changes, junctional complexes, secretory spaces, microvilli, and basement membrane formation. A disaggregated undifferentiated tumor now appeared as a differentiated adenocarcinoma. PE induced expression of laminin and milk protein, but failed to increase fibronectin expression. Extracts of MTOM (a variant of MtTW10 which secretes little PRL) and bovine pituitary also produced aggregation and adhesion of MTW9. A number of tissue extracts, growth factors, and hormones failed to produce such aggregation. Laminin, but not fibronectin, produced aggregation and adhesion similar to those produced by PE. Cycloheximide inhibited the aggregation effect of PE, but not that of laminin. PE was mitogenic for MTW9, but inhibition of proliferation by vinblastine did not inhibit the aggregation induced by PE. These observations suggest that the pituitary contains a novel factor that stimulates matrix synthesis, resulting in differentiation, possibly laminin induced.

Animals↗
PubMed1992

Immunotherapy of chronic active viral hepatitis B with propionibacterium granulosum KP-45 (a 5-year follow-up report).

In the period 1982 to 1984, 14 HBS-AG-positive patients with chronic active hepatitis B were treated monthly with a cell wall preparation (5 or 10 mg) of Propionibacterium granulosum KP-45 (PG), intravenously administered for a period of 6 to 10 months. All 14 patients were monitored by serological and biochemical tests as well as liver biopsy two, three and five years after completing immunotherapy with PG. During this period the patients received neither a specific antiviral, corticosteroid or interferon therapy, nor PG. Re-appearance of HBSAG or HBeAG was never seen in patients who were already free from the antigens one year after completing PG immunotherapy. During the 5-year follow-up, spontaneous improvement in serological and morphological (liver biopsy) parameters of chronic virus B hepatitis occurred in six patients. Five years after completion of PG immunotherapy, only four of the 14 patients showed trace amounts of serum HBSAG (carriers), and in two low levels of anti-HBeAG were present, while the whole group showed a decreasing tendency and serum anti-HBc was still detectable in six patients. HBeAG- and DNA-polymerase-positivity was absent in all patients. Microscopic examination of liver biopsies 5 years after PG immunotherapy showed mild symptoms of chronic hepatitis with inflammatory infiltration, non-active cirrhosis, but without massive periportal and/or multilobular necrosis and trace amounts of HBsAG and HBcAG in hepatocytes only in the four carriers. The remaining 10 patients were free of symptoms of active hepatitis and/or active cirrhosis, but all the patients had moderate to intensive fibrosis in their liver biopsies.

Adjuvants, Immunologic↗
PubMed1992

Early in-vitro histological chondral differentiation.

In vitro chondrogenesis is possible in the chick embryo from stage 4 of Hamburger and Hamilton (1951), only 18-19 hours of incubation, before somite formation. In stage 4 of Hamburger and Hamilton (1951) the chondroblasts are placed laterally to the primitive streak and notochord cells are not necessary for cartilage differentiation.

Animals↗
PubMed1992

Use of computerized interactive morphometry in the diagnosis of mammary adenoma and adenocarcinoma in dogs.

We attempted to define quantitative objective criteria for diagnosis of mammary adenoma and adenocarcinoma in dogs. To that end, correlation between diagnosis made by conventional histologic examination and morphometric descriptors, obtained by computerized histologic analysis, was assessed in biopsy specimens of mammary tissue from 63 dogs. We used 2 interactive computer procedures: one assessed mean nuclear perimeter, mean nuclear area, and circularity factor; and the other evaluated nuclear stratification and cell crowding. A data base was generated with 11 specimens from normal mammary tissue, 17 specimens from mammary adenoma, 18 specimens from low-grade mammary adenocarcinoma, and 15 specimens from mammary adenocarcinoma. The mean values of nuclear perimeter, nuclear area, nuclei per millimeter of basement membrane, and minimal distances from cells to basement membrane gradually increased from normal to high-grade malignancy. Distributions of nuclear areas and of minimal distances from cells to basement membrane were shifted in specimens from malignant tumors. Multivariate analysis confirmed the homogeneity of the diagnostic groups.

Adenocarcinoma↗
PubMed1991

6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in rat brain.

The concentration of fructose 2,6-bisphosphate in the brain remained stable during starvation and early stages of ischaemia, but decreased in diabetes or after lengthened ischaemia. 6-Phosphofructo-1-kinase activity was also decreased in diabetic and ischaemic animals, whereas 6-phosphofructo-2-kinase was not modified. The concentration of the bisphosphorylated metabolite seems to be remarkably constant under a wide variety of experimental conditions, suggesting that it plays an essential role in the basal activation of 6-phosphofructo-1-kinase. Purified 6-phosphofructo-2-kinase also showed fructose-2,6-bisphosphatase activity with an activity ratio similar to that of the purified heart isoenzyme. The brain enzyme also has a net charge similar to that of the heart isoenzyme. Its activity is not modified by sn-glycerol 3-phosphate, and it is more sensitive to citrate than the liver or muscle isoenzyme. Moreover, the enzyme from brain, similarly to that from heart and muscle, is not modified by the cyclic AMP-dependent protein kinase or protein kinase C. A near-full-length cDNA probe from liver hybridized with RNA from brain and heart. In both cases, a major band of 6.8 kb of RNA and a minor one of 4 kb of RNA were detected. All these properties support the hypothesis that brain contains a different isoenzymic form from that of liver and muscle, and it is probably related to the heart isoform.

Animals↗
PubMed1991

Bombesin, vasopressin, and endothelin rapidly stimulate tyrosine phosphorylation in intact Swiss 3T3 cells.

The mitogenic neuropeptides bombesin and vasopressin markedly increased tyrosine and serine phosphorylation of multiple substrates in quiescent Swiss 3T3 fibroblasts, including two major bands of Mr 90,000 and 115,000. Tyrosine phosphorylation of these proteins was increased as judged by immunoprecipitation of 32Pi-labeled cells and immunoblotting of unlabeled cells with monoclonal antiphosphotyrosine antibodies, elution with phenyl phosphate, and phospho amino acid analysis. Phosphotyrosyl proteins generated by bombesin and vasopressin did not correspond either by apparent molecular weight or by immunological and biochemical criteria to several known tyrosine kinase substrates, including phospholipase C gamma, the microtubule-associated protein 2 kinase, GTPase-activating protein, or phosphatidylinositol kinase. The effect was rapid (within seconds), concentration dependent, and inhibited by specific receptor antagonists for both bombesin and vasopressin. The endothelin-related peptide, vasoactive intestinal contractor, also elicited a rapid and concentration-dependent tyrosine/serine phosphorylation of a similar set of substrates. These results demonstrate that neuropeptides, acting through receptors linked to GTP-binding proteins, stimulate tyrosine phosphorylation of a common set of substrates in quiescent Swiss 3T3 cells and suggest the existence of an additional signal transduction pathway in neuropeptide-induced mitogenesis.

1-Phosphatidylinositol 4-Kinase↗
PubMed1991

Antigen shedding vs. development of natural suppressor cells as mechanism of tumor escape in mice bearing Ehrlich tumor.

C57BL/6J mice immunized with devitalized Ehrlich tumor (ET) cells produce high serum levels of IgM antibodies to ET cell-surface carbohydrates that are critical in the observed resistance against this tumor. However, this response is not found in ET-bearing mice at any stage of tumor development. Since previous studies had shown splenic natural suppressor (NS) cells in ET-bearers, their role in such IgM impairment was assessed. Here we show that tumor-bearers' spleen cells (TBSC) are unable to produce IgM in vitro in response to LPS, due to the presence of NS cells. Nevertheless, TBSC do produce IgM antibodies to ET cell-surface carbohydrates in increasing amounts as the tumor progresses. Yet these antibodies are not detected in sera of ET-bearers and are greatly decreased in immunized mice with a growing tumor. Moreover, increasing amounts of circulating carbohydrates, able to absorb most specific IgM, are found in ET-bearing sera associated with a large molecular size structure(s). These carbohydrates are also found in ET cell-culture supernatants and cell-free ascites fluid derived from this tumor, indicating their tumor origin. Taken together, our results indicate that lack of specific IgM antibodies in ET-bearing mice is not due to faulty production, but to in vivo absorption by carbohydrates shed from ET cells in increasing amounts as the tumor progresses. Thus, NS cells are unable to suppress this IgM production in vivo, despite the strong suppressor activity they show for many responses in vitro.

Animals↗
PubMed1991

Correlation of nuclear morphometry and DNA ploidy in rectal cancer.

Several investigators have used morphometric measurements to determine differences in the nuclear size and shape of normal and neoplastic colorectal tissue. Changes in nuclear morphometric parameters have also been shown to correlate with prognosis in a variety of noncolorectal cancers. The association of nuclear morphometry with prognostic indicators in rectal cancer has not been well studied. Measurements of the nuclear area, perimeter, longest cord, and circularity factor from 39 primary rectal adenocarcinomas were compared with DNA content, degree of tumor differentiation, Dukes' class, and patient survival. Nuclear circularity was found to correlate with DNA ploidy. Nondiploid tumors with a DNA index greater than 1.3 had significantly more circular nuclei than tumors with diploid or near-diploid DNA content. There was no correlation between nuclear morphometry and Dukes' class or patient survival. Significant increases in DNA content of rectal cancers appear to be reflected by measurable changes in nuclear shape. Nuclear morphometric measurements may provide useful information in the study of the progression of neoplastic changes in colorectal cancer.

Actuarial Analysis↗