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Biomedical subjects

J Gil

Publications and source records attributed to J Gil.

At least 181 records · Page 10Linked to original sources
PubMed1993

Altered diaphragm function modifies neonatal lung growth: biologic morphometric assessment.

Thoracic volume relationships supported by the diaphragm are important mechanical components of neonatal lung growth. Alterations modify regional lung growth. We used stereologic morphometry to study effects of altered diaphragm function on alveolar growth in neonatal pigs. Nine piglets (1 mo) were divided into three groups: unilateral phrenectomy, noncompliant patch replacement of diaphragm, and sham. Seven days later lungs were fixed in situ with 2.5% glutaraldehyde by airway installation at 20 cm H2O. Five 1-mm cubes were cut from lung corresponding to apex/RUQ(A), base/RLQ(B), apex/LUQ(C), and base/LLQ(D) and prepared for light microscopy (n = 25/quad/animal). Stereologic morphometry involved point counting for air volume density and point intersect to determine the surface area density of the alveolar spaces. Results were analyzed for variance and by Tukey range testing. Variance of air volume % between groups-quadrants B, C, D had decreased air volume % in phrenectomy group compared with patch and sham group (P < .05). Variance of air volume % within groups, for phrenectomy group A (81.5%), is different from all others (B = 70.6%, C = 75.5%, D = 66.7%); C is different from D (P < .05). For patch and sham group, D (P = 74.8%, S = 80.7%) is different from A (P = 84.1%, S = 86.6%) and C (P = 86.2%, S = 84.4%). Variance of surface area density between groups--quadrant D had increased surface area density % in phrenectomy group compared to sham group (P < .05). Variance of surface area density % within groups, for phrenectomy group, A (37.9 mm-1) is different from D (55.7 mm-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1993

Morphometric differentiation between responsive tumor cells and mesothelial hyperplasia in second-look operations for ovarian cancer.

We developed a procedure based on computerized image analysis to establish objective criteria for the differential diagnosis between mesothelial hyperplasia and cancer in peritoneal tissue samples obtained at second-look operations for ovarian cancer. The tumor tissue after chemotherapy was classified as "nonresponsive" if it was found by histologic criteria to be roughly similar to the tumor before chemotherapy and as "responsive" if it was found to be different (small clusters of bland-looking cells with no mitotic activity). Eighty-five samples of tissue had been classified previously by a pathologist into one of the four following groups: ovarian tumor prior to chemotherapy, "responsive" tumor, "nonresponsive" tumor, or mesothelial hyperplasia. Cell profiles of the tissue samples were studied by computerized image analysis using 21 morphometric descriptors derived from the manual tracings of tumor nuclei, including nuclear perimeter, nuclear area, maximal chord, circularity factor, and standard deviations of these descriptors. Size distribution curves of nuclear areas and maximal chords were included in the analysis. A multivariate discriminant analysis confirmed the separation into the four diagnostic groups, accomplished with consideration of the physical descriptors alone, except for some overlapping between groups 1 and 3. The separation between carcinoma and mesothelial hyperplasia was clear in all cases.

Cell Nucleus↗
PubMed1993

Neonatal group B streptococcal infection in Mallorca, Spain.

Early onset infection in neonates caused by group B Streptococcus and the prevalence of colonization by this microorganism in a group of 1,003 pregnant women and their neonates were studied. The capsular serotypes of the colonizing and infecting bacterial isolates and the components of C protein expressed were determined. Except for serotype IV, all the currently recognized capsular serotypes (including serotype V) were found. Among the colonizing strains, serotypes III, Ia, and Ib were almost equally represented and accounted for 82% of the isolates. Serotype III was predominantly found in cases of infection (55%), and serotypes Ia and V were also found in such cases. C protein was not detected in serotype III isolates, but alpha and/or beta components of this protein were found in isolates of all other serotypes. Neonatal infection and colonization due to this microorganism were observed in 1.2 cases per 1,000 live births and in 7.1% of pregnant women. Host factors for infection, such as low birth weight, premature delivery, and prolonged rupture of membranes, were uncommon. The level of specific antibodies to serotype III was also quantitated; lower levels were found in infected children and their mothers than in healthy infants and pregnant women. Further similar studies in Spain are necessary so that preventive measures can be planned.

Antibodies, Bacterial↗
PubMed1993

Development of an enzyme-linked immunosorbent assay method for typing and quantitation of Klebsiella pneumoniae lipopolysaccharide: application to serotype O1.

We describe a method for the typing and quantitation of Klebsiella pneumoniae serotype O1 lipopolysaccharide (LPS) based on inhibition in an enzyme-linked immunosorbent assay of a reaction of known O1 LPS antigen and anti-O1 antibody by unknown LPS extracts. Serotype O1 was found in 32% of the 124 K. pneumoniae clinical isolates tested, showing that this serotype is frequent among the eight O serotypes which have been described previously.

Bacterial Typing Techniques↗
PubMed1993

Evaluation of different criteria for the separation of pleural transudates from exudates.

OBJECTIVES: To determine the relative usefulness of different criteria for the separation of pleural transudates from exudates. DESIGN: Prospective evaluation of patients referred for thoracentesis. SETTING: Community teaching hospital. PATIENTS: Three hundred fifty-one consecutive patients with pleural effusions referred for thoracentesis. Fifty-four of these patients were excluded from the analysis. MEASUREMENTS: We recorded clinical characteristics and final diagnosis and measured pleural fluid and serum levels of total protein, lactate dehydrogenase, and cholesterol. All patients included were followed up until final diagnosis. MEAN RESULTS: Forty-four (15 percent) pleural effusions were transudates and 253 (85 percent) were exudates. The criteria of Light et al, with a sensitivity of 98 percent and a specificity of 77 percent for exudates, showed the best accuracy (95.2 percent). Moreover, when the cutoff used for the criteria of Light et al was modified according to our own laboratory results, specificity rose to 93 percent with almost a similar accuracy (94 percent). Protein pleural fluid/serum ratio > 0.5 and pleural fluid cholesterol > 60 mg/dl showed equal specificity (91 percent), but the former had better sensitivity for exudates (88 percent vs 81 percent). CONCLUSIONS: When the proportion of exudates included is 85 percent or more, as in the present series, the criteria of Light et al remain the method that offers the highest accuracy for segregating transudates from exudates.

Adolescent↗
PubMed1993

Leu-arylamidase activity levels during the estrous cycle and pregnancy in several extrahypothalamic areas of the rat brain.

A wide variety of behavioral changes in the female rat have been associated with the estrous cycle, pregnancy, and the postpartum period and their accompanying hormonal fluctuations. Since aminopeptidase activity, that presumably controls the activity of several neuroactive peptides, has been implicated in the control of these hormonal changes, the present study examined the tissue levels of Leu-arylamidase activity (Leu-ArA) in the cortices (frontal, parietal and occipital), striatum, hippocampus, amygdala, pineal gland and medulla oblongata during the estrous cycle, different stages of pregnancy (2nd, 7th, 14th and 20th postinsemination day) and the postpartum day. In the estrous cycle, Leu-ArA was significantly increased during the afternoon of the proestrous in the occipital cortex, amygdala and medulla oblongata. In general, higher enzyme levels were found during the middle stages of pregnancy. There is a significant rise after parturition in the occipital cortex, and clear but insignificant increases in the striatum and medulla. It is suggested that several extrahypothalamic areas may mediate several effects on Gn-RH secretion from the hypothalamus, and that Leu-ArA could be implicated.

Animals↗
PubMed1993

Morphometric analysis of benign and malignant adrenal pheochromocytomas.

At present, there are no reliable histologic features that can predict malignancy in adrenal pheochromocytomas other than the documentation of metastases. With the use of computerized interactive morphometry, our aim was to assess nuclei from tissue sections of confirmed cases of benign and malignant pheochromocytomas to determine whether consistent quantitative differences existed between the two. Eight benign cases with at least a 5-year follow-up and nine malignant cases with documented metastases were evaluated. Size distribution plots of the maximum nuclear cord length and of the nuclear area showed a narrow peak for the malignant cases, whereas benign cases showed a right-shifted curve with a wider peak. We concluded that nuclear morphometric analysis of benign and malignant pheochromocytomas yields two distinctive patterns and may be of utility in the assessment of future cases.

Adrenal Gland Neoplasms↗
PubMed1993

Morphometric analysis of neoplastic renal aspirates and benign renal tissue.

This study was designed to develop a practical morphometric procedure for the diagnosis of carcinoma in renal aspirates. We studied aspirates from renal cell carcinomas (grades 1-2) and normal kidneys. Video images of nuclei were traced on a high-resolution, touch-sensitive screen connected to an image analysis system. From each tracing the computer calculated nuclear perimeter length, nuclear profile area, maximal chord length, and the means and standard deviation for all measurements. Size distribution of nuclear profile areas and perimeter length in discrete bins ranged, respectively, from 30 to 80 at 10 microns2 intervals for areas and from 1 to 12 microns at 1-micron intervals for the maximum chords. The size distribution plots for the maximal chord of individual nuclei demonstrated an early narrow peak at low values for normal renal aspirates (peak located in the class ranging from 7 to 8 microns), while a broader, flatter peak with a shift to the right and a malignant tail was seen in renal cell carcinoma aspirates (peak located at 9-10 microns). These data were used for multivariate analysis to form two categories to establish a data base against which unknown cases could be tested. Multivariate analysis using a total of 14 variables yielded a value of 169.1 for the euclidean distances between the center of clusters of the neoplastic and normal renal aspirates and confirmed the classification with posterior probabilities of 1.0. From these data, automated classificatory analysis of 10 unknown cases was performed by means of the k-nearest neighbor procedure, with correct classification established in each case.

Biopsy, Needle↗
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

Effect of a bioengineered pseudorabies (Aujeszky's disease) vaccine on the semen quality of boars.

Eight boars 11 months of age that were seronegative to pseudorabies virus were trained for hand collection of semen. A genetically engineered pseudorabies virus vaccine was given to 7 of 8 boars, while the eighth was left unvaccinated to serve as a control. Semen samples were collected at 7 day intervals from 42 days prior to vaccination through 49 days after vaccination. Rectal temperatures and general health of the boars were clinically normal throughout the trial, and no clear differences were observed in the quality of semen collected from the boars before or after vaccination. The semen samples were tested for vaccine virus and none was detected.

Journal Article↗
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↗