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Biomedical subjects

P Capek

Publications and source records attributed to P Capek.

36 records · Page 2Linked to original sources
PubMed1990

[Expression of CA 19-9 in tubular and tubulovillous adenomas of the descending and sigmoid colon and the rectum with respect to morphologic differentiation characteristics and the adenoma-carcinoma sequence].

Expression of CA19-9 was studied in 29 adenomas and 6 adenocarcinomas of the distal colon in rectum. The authors did not find an unequivocal correlation between expression of CA19-9 and the morphological differentiation. Expression of CA19-9 was recorded twice in epithelia of normal mucosa.

Adenocarcinoma↗
PubMed1989

[The so-called sclerosing hemangioma of the lungs].

A 12-year old girl had a focal density in the lung found by checking CT. Structural features were those of the so called sclerosing hemangioma. Analysis of structure in various methods and of references supported authors' interpretation that lesion represented a late consequence of pecul a obliterative mainly venous process with prevailing plasmacytic feature. Characteristic segmental destructive venous lesion conused segmental obliterat on and hyalinization. Similarity of the lesion to intravascular fasciitis was discussed. Peripheral accumulation of pneumocytes around the lesion seemed to be secondary. To name it pneumocytoma would be unproper and a possibility of vascular tumorous character could not based on respectable analogies. A closer etiopathogenetic specification of the so called sclerosing hemangioma of the lung remains to be accomplished.

Child↗
PubMed1989

[Methodologic aspects of immunoperoxidase technics].

In attempt to standardize immunoperoxidase tests many partial methodological experiments were performed and the results discussed. The proved processing included purification of peroxidase conjugates, sequential administering in double indirect immunoperoxidase method (double sandwich). A high level dilution of primary antibodies and lengthening of incubation were recommended. Silicagel and vaseline rim round sections were found advantageous for improving adhesion of paraffin sections.

Immunoenzyme Techniques↗
PubMed1989

[Bizarre cells in pseudotumors of the digestive tract].

Aneuploid cells were studied in the mucous stroma in 10 bioptic excisions of the tongue, gums, stomach, colon, rectum and anus. These bizarre cells corresponded most probably to fibroblasts, macrophages and endotheliomas strangely proliferating in inflammatory polyps, granular tissue and hyperplastic stroma. Significance of repeated mechanical irritation for pathogenesis of this reactive phenomena in projecting pseudo-tumours is stressed.

Adult↗
PubMed1988

Adaptive histogram equalization in digital radiography of destructive skeletal lesions.

Adaptive histogram equalization, an image-processing technique that distributes pixel values of an image uniformly throughout the gray scale, was applied to 28 plain radiographs of bone lesions, after they had been digitized. The non-equalized and equalized digital images were compared by two skeletal radiologists with respect to lesion margins, internal matrix, soft-tissue mass, cortical breakthrough, and periosteal reaction. Receiver operating characteristic (ROC) curves were constructed on the basis of the responses. Equalized images were superior to nonequalized images in determination of cortical breakthrough and presence or absence of periosteal reaction. ROC analysis showed no significant difference in determination of margins, matrix, or soft-tissue masses.

Bone Neoplasms↗
PubMed1987

Porta hepatis: duplex Doppler US with angiographic correlation.

Duplex Doppler ultrasonography (US) and panhepatic angiography were performed and interpreted independently in 20 patients with suspected portal hypertension to assess the accuracy of duplex US in the porta hepatis. Hepatic arterial resistive indexes were correlated with corrected sinusoidal pressures. The results of duplex US agreed with those of angiography in 16 patients with a normal portal vein (including three with hepatofugal flow) and two with total thrombosis. One angiographically normal portal vein appeared thrombosed on an initial sonogram, but a second scan was normal. One case of partial thrombosis was not diagnosed with duplex US. Sensitivity and specificity for main portal vein disorders were 83% and 93%, respectively. Two patients had portal vein branch occlusions that were found by angiography but not by US. Portal vein echogenicity was neither sensitive nor specific for thrombosis. The resistive index of the hepatic artery was specific for portal hypertension when above .78, but it was not sensitive. Duplex US is accurate in prospectively assessing the direction of flow and the presence of total thrombosis in the portal vein, but partial thrombosis may not be detected on sonograms.

Adolescent↗
PubMed1985

Histogram equalization of CT images.

Histogram equalization for display of clinical CT images was evaluated. In theory, histogram equalization makes optimal use of an available grey scale to display an image, and its use could circumvent the problem of selecting specific window settings for each image. In several clinical images, the use of a spatially variable histogram equalization technique limited to that portion of the CT image occupied by the patient did appear to increase the visibility of anatomic structures. However, using the technique also increased displayed image noise and artifacts. Although radiologists found this to be objectionable, it did not decrease the detectability of simulated low-contrast liver metastases. Further evaluation of histogram equalization for displaying CT images is being pursued.

Brain↗
PubMed1973

Axonal transport of dopamine- -hydroxylase by human sural nerves in vitro.

Dopamine-beta-hydroxylase activity accumulated above a ligature on biopsy samples of normal human sural nerves incubated in vitro. The rate of accumulation indicated that this enzyme was transported distally at a velocity of 2 millimeters per hour. Axoplasmic transport of dopamine-beta-hydroxylase was greatly reduced in sural nerves from a few patients with peripheral neuropathies.

Axonal Transport↗
PubMedDate not supplied

The effect of prolonged left ventricular support on myocardial histopathology in patients with end-stage cardiomyopathy.

To determine the histopathologic effect of prolonged (> 30 days) left ventricular unloading on the myocardium, the authors studied myocardial tissue specimens from eight men (mean age, 40.8 years) with end-stage cardiomyopathy (six idiopathic, two ischemic) who were supported with the HeartMate (Thermo Cardiosystems, Inc., Woburn, MA) left ventricular assist device (LVAD) as a bridge to cardiac transplantation. The average length of support was 79.6 days (range, 31-136 days). Before left ventricular support was instituted, transthoracic echocardiography revealed that all patients had significantly dilated left ventricular cavities (average left ventricular diastolic dimension, 7.2 cm). Tissue specimens from the core of the left ventricular apex, which is removed at the time of LVAD implantation, were compared through pathologic examination with specimens from the explanted hearts at the time of cardiac transplantation. Apical core specimens from all patients exhibited extensive areas of attenuated myocardial fibers, combined with wavy patterns in some areas. In these regions, the nuclei of the cardiac myocytes from idiopathic cardiomyopathy specimens were neither pyknotic nor disappearing, as was noted in an infarcted area of a specimen from one patient with ischemic cardiomyopathy. At the time of heart transplantation, myocardial tissue specimens from the explanted hearts had a significant decrease or disappearance of stretched fibers. There was also a slight increase in interstitial replacement fibrosis, as well as an increase in the diameter of the myocardial fibers. These findings appear to correlate with the clinical impression of improved native ventricular function and with radiographic findings and decreased chamber size during prolonged ventricular support.

Adult↗
PubMedDate not supplied

Human intraperitoneal response to a left ventricular assist device with a Ti-6AI-4V alloy surface.

The soft tissue reaction to long-term implantation of an intraperitoneal left ventricular assist device (LVAD) was investigated. The HeartMate 1000 (Thermo Cardiosystems, Inc., Woburn, MA) is a pneumatically driven blood pump with smooth titanium alloy (Ti-6AI-4V) outer surfaces that is placed intraperitoneally in the left upper quadrant and sutured to the anterior abdominal wall. It is being used currently as a bridge to cardiac transplant, which sometimes requires extended support times. We examined the tissue capsule that formed around the rigid circular pump housing of four LVADs (duration of implant: 61, 86, 128, and 153 days) for gross, histologic, immunohistochemical, and ultrastructural analysis. Immunostaining was performed using monoclonal and polyclonal antibodies against cytoskeletal tissue markers (vimentin, desmin, alpha-smooth muscle actin), T and B lymphocytes, carcinoembryonic antigen, factor VIII, and cytokeratins (CAM 5.2 AE1/AE3, 34 beta E12, and 35 beta H11). Direct fluorescent immunolabeling for fibrinogen was also performed to characterize cell and tissue type. Histologic analysis of the 3 to 4 mm thick capsule with white, glistening inner surfaces showed fibrovascular tissue with multipotential subserosal cells (MSCs), capillary endothelium, collagen, and a few mononuclear infiltrates. The immunohistochemical profile of the MSCs differed from myofibroblasts despite a morphologic similarity. Transmission electron microscopy revealed abundant rough endoplasmic reticulum and peripherally arranged myofilaments within the spindle shaped cells. It was hypothesized that capsule formation was initiated by fibrin deposition, followed by proliferation of MSCs and subsequent formation of fibrovascular tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗