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Biomedical subjects

Vladimir Kanjuh

Publications and source records attributed to Vladimir Kanjuh.

8 recordsLinked to original sources
PubMed2004

[Cytohistologic and immunohistochemical characteristics of the aortic intima and media in coarctation of the aorta of the adult type].

INTRODUCTION: Classically, coarctation of the aorta has been divided into infantile and adult forms. The vascular malformation responsible for coarctation is a defect of the vessel intima and media giving rise to a prominent posterior infolding ("the posterior shelf") which, in some cases, may extend around the entire circumference of the aorta. Histological examination of the coarcted aortic segment discloses intimal and medial lesion consisting of thickened ridges that protrude posteriorly into the aortic lumen. Intimal proliferation and disruption of elastic tissue may occur in adult type. OBJECTIVE: The smooth muscle cells phenotype in the aortic intimal thickening, presence of inflammatory cells and contents of the intimal and medial pseudocysts were investigated. MATERIAL AND METHODS: The samples of coarctation segments excised at surgery from 10 patients aged from 2 to 13 years were examined. For light microscopy, the specimens were dehydrated in graded ethanol (70-100%), cleared in xylol and embedded in paraffin. Sections of 5 microm thick were cut on Leica SM 2000R and Leica Reinhart Austria microtome and stained with orcein and Alcian blue-PAS at pH 1.0 and pH 2.5. Immunocytochemical staining was performed on 5 microm sections from formaldehyde-fixed paraffin-embedded blocks, using a labeled streptavidin-biotin method with an LSAB kit (Dako). Sections were deparaffinized and rehydrated. After microwave treatment of 21 minutes in citrate buffer pH 6.0, endogenous peroxidase activity was blocked with 3% H2O2 for 15 minutes. The sections were first incubated with the primary antibody for 60 minutes (alpha-smooth muscle actin-alpha-SMA, vimentin, desmin, myosin haevy chains-MHC, CD3, CD45, S-100 and Proliferating Cell Nuclear Antigen-PCNA), then with biotinylated link antibody and finally with peroxidase-labeled streptavidin. Slides were counter-stained with hematoxylin, washed in water and mounted. For electron microscopy, the primary fixative consisted of 2.5% glutaraldehyde in 0.1 M sodium cacodylate-HCl buffer (pH 7.4) for 24 h at 4 degrees C. The specimens were postfixed for 1 h at 4 degrees C in 1% osmium tetroxide in 0.1 M cacodylate buffer and 4.8% uranyl acetate for 24 h at 4 degrees C. The samples were dehydrated in graded ethanol (70-100%) and embedded in Epon 812. The samples were cut with a diamond knife on an LKB Ultratome. Ultra-thin sections were stained with 2% uranyl acetate and alkaline lead citrate. RESULTS: All samples had focal intimal thickening on the posterior aortic wall, with accumulation of mucins which were stained with Alcian blue-PAS on pH 1.0, followed by prominent hypocellularity. Rare smooth muscle cells (SMC) showed immunoreactivity on alpha-SMA and vimentin, but not on desmin, MHC or CD3 and CD45. A large number of cells in apoptosis was noticed in the inner media on the posterior wall. On the anteromedial wall, a large number of PCNA- and S-100- positive cells was noted in the inner media while one layer of MHC- and desmin-positive cells was noted in the outer media. The elastic lamellae were focally disrupted by pools which were stained with Alcian blue-PAS at pH 1.0. DISCUSSION: In all examined samples, the immunocytochemical and TEM results revealed the presence of dedifferentiated smooth muscle cells which express alpha-SMA and vimentin, with a lack of expression of desmin and MHC. Results of this study also showed the reduction of cell number in the intima and media, followed by apoptotic smooth muscle cells in the inner media of the posterior wall and the absence of inflammatory cells. Such finding suggests that apoptosis but not necrosis may be the mechanism of reduction of cell number. The presence of smooth muscle cell proliferation in the inner media of the anteromedial wall and one layer of differentiated SMC in the outer part may lead us to suppose that changes of media (including dedifferentiation of the cells and disruption of elastic tissue) appear from inner to outer part and from posterior to anteromedial wall. The presence of pseudocysts which are stained with Alcian blue-PAS at pH 1.0 show large amount of mucins in elastic fibers. CONCLUSION: The intimal thickening on the posterior aortic wall is composed of small number of dedifferentiated smooth muscle cells (SMC). Some of these cells are in apoptosis. On the anteromedial wall, the intima and media are composed of proliferated SMC and small number of SMC which exhibit contractile phenotype. In all parts of the aortic wall, there is a large number of pseudocysts with large amount of mucins, without presence of inflammatory cells.

Adolescent↗
PubMed2003

Diagnostic value of pericardial biopsy: improvement with extensive sampling enabled by pericardioscopy.

BACKGROUND: The clinical significance of pericardial biopsy is controversial. The aim of this study was to assess the feasibility and diagnostic value of 3 approaches to pericardial biopsy: fluoroscopic control and standard sampling, pericardioscopy guidance with standard sampling, and pericardioscopy guidance with extensive sampling. METHODS AND RESULTS: Forty-nine subsequent patients with a large pericardial effusion underwent parietal pericardial biopsy. In group 1 (12 patients, 66.7% males, age 46.7+/-12.2 years), pericardial biopsy was guided by fluoroscopy (3 to 6 samples per patient). Group 2 included 22 patients (50% males, age 50.8+/-10.4 years) undergoing 4 to 6 pericardial biopsies per patient guided by pericardioscopy (16F flexible endoscope). In group 3, extensive pericardial sampling was performed, guided by pericardioscopy (15 patients, 53.3% males, age 53.7+/-12.8 years, 18 to 20 samples per patient). Sampling efficiency was better with pericardioscopy (group 2, 84.9%; group 3, 84.2%) compared with fluoroscopic guidance (group 1, 43.7%; P<0.01). Diagnostic value was defined as a new diagnosis uncovered, etiology revealed, clinical diagnosis confirmed, and the biopsy false-negative. Pericardial biopsy in group 3 had higher diagnostic value than in group 1 in revealing new diagnosis (40% versus 8.3%, P<0.05) and etiology (53.3% versus 8.3%, P<0.05). In group 2, pericardial biopsy had a higher yield in establishing etiology than in group 1 (40.9% versus 8.3%; P<0.05). Pericardial biopsy was false-negative in 58.3% in group 1 in contrast to 6.7% in group 3 (P<0.01). There were no major complications. CONCLUSIONS: Pericardioscopic guidance enhanced pericardial sampling efficiency. The diagnostic value of pericardial biopsy was significantly improved by extensive sampling made possible by pericardioscopy.

Biopsy↗
PubMedDate not supplied

[Changes in calcium levels in blood and urine during various regimens of table salt intake in patients with essential arterial hypertension].

INTRODUCTION: It has been reported that changes in salt loading influence parameters of calcium metabolism in hypertensive subjects. It was also reported that response of blood pressure to salt intake is related to salt-induced increase in intracellular calcium and decrease in intracellular magnesium concentrations [1]. Several authors showed that salt-sensitive hypertensive subjects significantly decreased blood pressure after calcium intake which was emphasized by high salt intake. Resnick et al. showed that during high salt intake regimen increase in blood pressure was followed with decrease in serum calcium level, this was explained by the fact that high salt intake stimulates the calcium uptake by cells [2]. They also reported the following characteristics of hypertensive patients with additionally lower blood pressure as a response to calcium intake: salt-sensitive, low serum ionized calcium and plasma renin activity (PRA) values and high parathyroid hormonE (PTH) values and 1.25-(OH)2-D values. The aim of the study was to evaluate values of corrected and ionized serum and urine calcium in a group of salt-sensitive patients, salt-resistant patients and a whole group during normal salt-intake regimen, and a group without salt and during sodium load (10 g salt extra). MATERIAL AND METHODS: In our study, 50 untreated patients (27 women and 23 men; average age 42 +/- 9.2 yrs; average BMI 27.91 +/- 4.6 kg/m2) with essential hypertension were put on a high salt regimen (200 mmol NaCl per day) for one week after a week on a low salt diet (20 mmol NaCl per day). On the last day of the normal regimen and during the 1st, 3rd and 5th day of low salt and high salt regimens, the following follow-up was carried out: total (corrected) serum calcium level and total urine calcium level, ionized serum calcium urine creatininE level; serum albumin and daily diuresis and blood pressure. All patients had normal sodium and potassium serum concentrations. Salt intake was checked by taking a specimen of 24-hour urine considered as satisfactory if sodium excretion of 100 to 150 mmol/d (mmol per day) was noted. During the whole hospital examination, calcium intake through hospital meals was standardized to about 817 mg of calcium daily. Salt sensitivity was defined as 10 mmHg increase in mean blood pressure at the end of high vs. low salt diet. Salt sensitive group consisted of 26 patients and salt insensitive of 24 patients. RESULTS: According to sex, there was no statistically significant difference: 27 females (54%) and 24 males (46%). Average age of patients was 49 +/- 9.2 yrs, ranging from 21 to 64 with normal frequency distribution. Average body weight was 80.49 kg +/- 12.45 kg. Body height was from 150 to 192 cm with average of 170.12 +/- 10.53 cm. Average value of Body Mass Index (BMI in kg per square meter) was 27.91 +/- 4.6. In the studied patients average duration of hypertension was 6.98 +/- 6.4 yrs with non-homogeneous distribution. In 32 patients (64%) the medical history confirmed that one or more family members had hypertension. It was found that salt loading significantly decreased ionized calcium (F = 2.49; p < 0.05) and significantly increased urinary excretion of calcium (F = 5.22; p < 0.001) in salt sensitive patients in comparison with salt insensitive subjects. Serum calcium did not differ significantly during different salt intake regimens between two groups. Our study revealed no positive correlation between gender, age, BMI and family history and calcium metabolism. CONCLUSION: The findings of this study support the opinion of altered calcium metabolism in hypertensive subjects sensitive to salt intake. By demonstrated results we tried to define clinically different pathophysiologic and potentially different therapeutic subgroups in hypertensive population and to point to clinical and biochemical heterogeneity of primary hypertension.

Adult↗
PubMedDate not supplied

[Morphological changes in aorto-coronary vein graft--the analysis of autopsy and biopsy material].

BACKGROUND: Patients with implanted aortic coronary grafts have different survival time, which raises the question why the efficacy of graft implants is so poor. The aim of this study was to present the results of the analysis of morphological changes in the vein grafts taken after the death of patients who died after surgery in different time intervals, as well to present the analysis of the grafts obtained after surgical reintervention. METHODS: The total number of 656 grafts of 308 dead patients was analyzed, as well as 76 grafts from 40 patients who underwent surgical reintervention. According to the duration of the graft since surgical intervention until death, all the analyzed changes were divided into two groups: a) early changes and complications, and b) late changes and complications in aorto-coronary vein grafts. RESULTS: After the autopsy, 518 vein grafts from the first group were evaluated histopathologically. Changes were found in the form of small or large areas with peeled endothelium in 266 grafts, with the insudation of fibrin and thrombocytes in such places, subendothelial edema, and occlusive thrombosis of the graft lumen. Significant stenosis, which occurred distally from the anastomoses, was present in 118 grafts without changes in the walls of the graft, and there was significant narrowing of the graft lumen in 134 vein grafts due to intimal hyperplasia. In the second group, 138 grafts were histopathologically analyzed after autopsy. Significant hyperplasia was present in 117 grafts with the migration of smooth muscle cells from media into intima, and in 21 grafts there were atheromatous plaques. In 120 veins analyzed before the graft implantation, the lesion or the lack of endothelium was found, as well as the penetration of fibrin and blood elements and intimal hyperplasia. In 46 veins analyzed before the graft implantation, significant intimal hyperplasia with the elevated number of smooth muscle cells was found. CONCLUSION: The most frequent lesions in the grafts were the lesions of the endothelium, which caused thrombosis formation and lumen occlusion. Intimal hyperplasia in patients with longer survival time occurred due to the migration of smooth muscle cells from the media, or due to the formation of atherosclerotic plaques, which caused graft lumen stenosis or thrombosis.

Adult↗