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Biomedical subjects

S Nachev

Publications and source records attributed to S Nachev.

12 recordsLinked to original sources
PubMed2001

[Surgical treatment of coronary disease with ischemic mitral regurgitation--early and late results].

UNLABELLED: Patients with ischemic mitral incompetence have a high operative risk and the advantage of repair over replacement in those patients is unclear. In cases of moderate mitral regurgitation and coronary artery disease operative strategy continues to be debated between coronary artery bypass grafting (CABG) alone and concomitant valve replacement or repair. The objective of the study is to review our experience with the different surgical treatments and to assess the impact of pre- and intraoperative factors on mortality, morbidity and long-term survival. METHODS: From July 1990 to May 2000, 102 patients with ischemic mitral regurgitation > 2 + grade underwent operative treatment. CABG alone was performed in 52 and combined procedures in 50 cases (18 replacements and 32 repairs). Mitral repairs were accomplished by Carpentier or Key techniques and/or ring implantation. All replacements were done with preservation of the posterior mitral valve leaflet. RESULTS: Overall mortality is 11(10.8%)-3 patients (5.8%) in the CABG group and 8 (16%) in the combined group (3-16.7% for replacement and 5-15.6% for repair). There was 7 late deaths in both groups. Five year survival was 78% for CABG, 78% for repair and 76 for replacement. CONCLUSIONS: In high risk patients with ejection fraction < 35% and mitral regurgitation < 3 + grade we recommend CABG alone. Valve replacement is the procedure of choice in case of papillary muscle rupture. All patients need complete revascularisation. Good results are obtained with repair techniques and ring implantation.

Adult↗
PubMed1999

Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) and its receptor flt-1 in microcystic meningiomas.

We investigated the immunohistochemical expression of vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) and of its endothelial cell receptor flt-1 in relationship to microcyst formation in meningiomas. Expression of VPF/VEGF was studied in 60 meningiomas (6 microcystic, 38 partially microcystic and 16 with no microcystic areas) and 30 meningiomas from these three subgroups were evaluated for flt-1 expression. VPF/VEGF immunoreactivity was mainly observed in vessel endothelium. Positive vessels were present in 75% (33/44) of meningiomas with any amount of microcystic pattern and in 38% (6/16) of the solid meningiomas (P < 0.02). Densities and percentages of both VPF/VEGF-positive and flt-1-positive vessels were higher in meningiomas with microcystic areas than in solid meningiomas (P </= 0.002). The 6 microcystic meningiomas showed the highest densities and percentages of both VPF/VEGF-positive (P </= 0.0002) and flt-1-positive vessels (P </= 0. 01). Vessel expression of VPF/VEGF and flt-1 were positively correlated (r >/= 0.75, P < 0.0001). A strong positive correlation between VPF/VEGF-positive vessel density and proportion of microcystic pattern in all 60 specimens was found (r = 0.75, P < 0. 0001). We conclude that accumulation of flt-1-bound VPF/VEGF on endothelial cells of meningiomas is associated with microcyst formation that leads to the histologic appearance of microcystic meningiomas.

Endothelial Growth Factors↗
PubMed1993

[Morphological changes in the nervous system in lead poisoning. II. Experimental lead-induced encephalopathy].

The morphological investigation in an experimental model of lead (Pb) encephalopathy (according to the method of A. Pentschew, 1966) is presented. Electron microscopy-dense inclusions are found out in the nuclei and cytoplasm of astrocytes and in some ependyma cells in the investigated cortical and subcortical (paraventricular) structure of the brain and spinal cord. This confirms the direct toxic action of Pb on these structures and proves their participation in pathogeneses of the developing encephalopathy. The established inclusions in the ependyma and the data about a disturbance of the blood-brain barrier give a reason to be proposed the possibility for a penetration of Pb in the nervous system not only through a blood but also through a cerebrospinal fluid way.

Animals↗
PubMed1993

[Polypous endocarditis of the tricuspid valve. The morphological changes in the heart and lung in one case].

A case of polypous endocarditis which affects the tricuspid valve and whose genesis remains unclear (a septic state, an idiopathic disease?) is described. Clinically the disease has taken its course as a chronically recurring form of pulmonary thromboembolism. Morphologically it concerns to a massive fibroplastic verrucous endocarditis of the tricuspid valve and a more slightly expressed similar process in the wall of the right atrium and ventricle, combined with a significant fibrosis of the myocardium. The death has come from a massive thrombotic embolism in the two branches of the pulmonary artery on the background of a great number of small thromboembolic and hemorrhagenic infarctions with a different duration in the two lobes of the lung, which lead to an adaptable reconstruction of many lung vessels. The presence of a discrete affection of the aortic valve according to a rheumatic type and the combination of the disease, in the described case, with essential hypertension and thrombophlebitis undergone in the past, give a reason to discuss the possibility of taking into account these diseases in etiopathogenesis of the described myocardiopathy.

Endocarditis↗
PubMed1992

A unique case of naturally occurring mummification of human brain tissue.

When skulls and bones were exhumed from a mass grave in Bulgaria and subjected to medicolegal examination they were found to originate from 39 humans aged 36-60 years old who had been buried approximately 45-50 years ago. Solid structures which strongly resembled shrunken human brain tissue were found inside 2 intact skulls. Among other bones 5 similar structures were found one of which was an almost entirely preserved human brain, and the others were fragments from different regions of the human brain. Samples of these structures were immersed in 15% aqueous glycerol solution to soften and were examined by light and electron microscopy. Samples of this material and of fresh human brain were subjected to elementary atomic spectral analysis. These complex studies indicated the samples to be naturally mummified human brain tissue and that this process had occurred due to specific conditions within the cranial cavities after burial.

Adult↗
PubMed1992

Hemangioblastoma during pregnancy. Case report.

A 20-year-old pregnant woman (8th month of gestation) developed signs of intracranial hypertension and coordination disorders. The CT examination demonstrated hydrocephalus, occlusion of the IV ventricle and hyperdense mass lesion in the right cerebellar hemisphere. Following ventricular drainage cesarean section was performed and then total removal of cerebellar hemangioblastoma, which resulted in rapid and complete reversal of neurological abnormalities of the mother and the child.

Adult↗
PubMed1990

[Morphological changes in the nervous system in lead poisoning. I. Experimentally induced lead neuropathy].

A morphological study on experimental model of lead (Pb) neuropathy (by the method of Pentschev, A., 1966) was described. Dense inclusions in Schwann's cells and satellite cells of the sensory ganglia were found by an electron microscope in the examined peripheral nerves (n. ischiadicus) and sensory ganglia (g. lumbale and g. trigeminale--Gasseri). These finding supported direct toxic action of Pb on these structures and proved their participation in the pathogenesis of developing neuropathy.

Animals↗
PubMed1989

[Long-term observation of a case of Hand-Schüller-Christian disease].

A case is presented of a 28-year-old man with Hand-Schüller-Christian's disease whose initial manifestations were skull bones lesions and a diffuse interstitial fibrosis. Three years later the patient developed diabetes insipidus without changes in the hypothalamic-hypophysial region on computed tomography. Some features of the clinical picture are discussed.

Adult↗
PubMed1986

[Multiple endocrine adenomatosis manifested chiefly by hyperparathyroidism].

A case with multiple endocrine neoplasia was reported, including parathyroid adenoma, of the main cells of the gland, multiple small adenomas in the tail of pancreas, (cytologically and electron-microscopically determined as A cellular) and light-cellular adenoma of adrenal. The hyperfunction of parathyroid adenoma was manifested with hypercalcemia (3.75 mmol/l), and morphologically--with the multiple calcium metastases in lungs, kidneys and heart, established at necropsy. The cause for the death was the acutely advanced ischemic disease of myocardium, on the background of chronic pyelonephritis and renal insufficiency. The timely diagnosis of such morbid states is concluded to be important for the clinical practice and could lead to the saving of the patients by operative removal of the tumour.

Adenoma↗
PubMed1983

[Vascular changes in the lung in a case of primary (idiopathic) pulmonary hypertension].

The authors present one lethal case of primary pulmonary hypertension (PPH) in a male of 40. The pathomorphological examination revealed very characteristic changes in the vessels of the lungs. Often slot-like canals were found, with proliferated myoepithelial cells, connecting the lumena of vessels with thickened walls with thin-wall vessels ("plexiform changes") or with vessels with sinusoidal-cavernous type ("angiomatoid formations"). Those vascular changes are in a strong contrast with the absence of inflammatory alterations in the lungs. The possibilities of developing of similar vascular changes in the lungs, leading to PPH are discussed in accordance with the up-to date literature data.

Adult↗
PubMed1976

[Enzootic dermonecrosis in chickens].

An enzootic of necrotic dermatosis in hen layers was described. The changes consisted in that they had constant localization and demarkated sites on the skin between the back and the neck. The disease was observed on a farm for 5000 layers in the course of two consecutive years. All birds contracted the disease and in the first year they recovered the 10 months; in second year they recovered for three months. Each bird showed symptoms for 3 weeks. The skin lesions resulted in cicatrization. The etiologic agent (a Pasteurella-like organism) was isolated from the necrotic foci. It proved pathogenic for albino mice and manifested biochemical activity and morphology characteristic of Pasteurella multocida. The disease was successfully reproduced with a broth culture applied on a scarified skin of test birds. Histopathologically, the spontaneous lesions proved undistinguishable from the experimental ones and represented coagulation necrosis of the epidermis, derm, and subcutis. It is supposed that the constant localization was due to the porte d'entrer of the infection, associated with the bad habit of picage on the neck as demonstrated on a large scale by the birds of the infected flock. This is characteristic of some lines of the White Leghorn breed.

Animals↗