Comparative study of calcification in human choroid plexus, pineal gland, and habenula

Choroid plexus, pineal gland, and habenula tend to accumulate physiologic calcifications (concrements) over a lifetime. However, until now the composition and causes of the intracranial calcifications remain unclear. The detailed analysis of concrements has been done by us using X-ray diffraction analysis (XRD), X-ray diffraction topography (XRDT), micro-CT, X-ray phase-contrast tomography (XPCT), as well as histology and immunohistochemistry (IHC). By combining physical (XRD) and biochemical (IHC) methods, we identified inorganic (hydroxyapatite) and organic (vimentin) components of the concrements. Via XPCT, XRDT, histological, and IHC methods, we assessed the structure of concrements within their appropriate tissue environment in both two and three dimensions. The study found that hydroxyapatite was a major component of all calcified depositions. It should be noted, however, that the concrements displayed distinctive characteristics corresponding to each specific structure of the brain. As a result, our study provides a basis for assessing the pathological and physiological changes that occur in brain structure containing calcifications.

[Clinical, biochemical and histological indicators of Del Nido cardioplegia efficacy in patients with severe myocardial hypertrophy]

OBJECTIVE

To evaluate the effectiveness of two cardioplegia techniques in patients with severe myocardial hypertrophy undergoing septal myectomy or aortic valve replacement.

MATERIAL AND METHODS

A comparative pilot prospective single-center randomized study included 46 patients between 2022 and 2023. Patients were randomized into 2 groups: Del Nido (n=23) and Custodiol (n=23). We analyzed perioperative echocardiography data, troponin I at several time points, perioperative complications and histological data.

RESULTS

Both groups were comparable in time of myocardial ischemia, cardiopulmonary bypass, duration of anesthesia and surgery (p>0.05). The maximum ischemia time in the Del Nido group was 84 min. The same group showed significantly higher percentage of spontaneous rhythm recovery (65.2% vs. 30%, p=0.008). None patient required mechanical support, high-dose inotropes or vasopressors. Troponin I in 2 hours after cardiopulmonary bypass (p=0.415), 12 (p=0.528) and 24 hours after admission to the intensive care unit (p=0.281) were similar in both groups. No significant difference was found in ventilation time, ICU- and hospital-stay.

CONCLUSION

Del Nido cardioplegia has some advantages compared to Custodiol and does not lead to perioperative complications in case of aortic cross-clamping time <90 min in patients with myocardial hypertrophy.

[Primary delayed growth of the right and left atrial myxoma]

There is more than 58-year experience of surgical treatment of patients with intracardiac myxomas at the Petrovsky National Research Center of Surgery. Primary delayed growth of the right and left atrial myxoma after 21 years and 5 months was observed only in 1 (0.36%) patient. Transthoracic echocardiography was used for diagnosis of tumors. Tumors were totally resected including adjacent parts of myocardium or subendocardial tissue with subsequent cautery. In-hospital mortality was absent. There were no recurrent myxomas throughout subsequent 10-year follow-up.

[Inflammatory infiltrates, vasa vasorum, and endothelial NO synthase in the wall of thoracic aortic aneurysm]

OBJECTIVE

To elucidate whether there is a relationship between inflammation of the wall of aortic aneurysm and the number of vasa vasorum in it.

MATERIAL AND METHODS

The investigation material was aortic aneurysm wall segments obtained during surgery. Among the patients, there were 20 men and 5 women. The patients' age ranged from 33 to 69 years. The investigation used monoclonal antibodies to macrophages (CD68), T cells (CD3, CD4, and CD8) and antibodies to von Willebrand factor, endothelial NO synthase, and alpha smooth muscle actin. A morphometric study was conducted.

RESULTS

Calculation of the number of vasa vasorum (including newly formed vessels) in the adventitia of aortic aneurysm revealed that there was a statistically significant difference between the number of vasa vasorum in patients with an active inflammatory response (Group 1) versus Group 2 patients with a moderate inflammatory process in the aneurysm wall (p≤0.05) and a statistically significant difference between Groups 1 and 3 (without inflammatory infiltrates) (p≤0.05). Endothelial vasa vasorum heterogeneity was found in case of an immune response to NO synthase. At the same time individual vasa vasorium did not contain NO synthase, this enzyme was identified in the endothelium in a number of nearby vessels.

CONCLUSION

The increase in the number of vasa vasorum in the aneurysm wall in patients with abundant inflammatory infiltrates is due to the fact that some of the inflammatory cytokines of T-cells and macrophages also contribute to angiogenesis.

[Prospects and peculiarities of the procedure of ultrasound ablation of subcutaneous veins of the lower limbs]

The last decade has seen active development of minimally invasive (endovenous) methods of surgical removal of lower limb varicose veins (LLVV); however, the problem of increasing efficacy of these methods and improving long-term results still remains of current importance. The authors of this work propose a method of ultrasound ablation of subcutaneous veins of lower extremities. Our experimental study was aimed at determining the pattern of venous wall damage after ultrasound exposure. Samples of segments of the trunk of the great saphenous vein (GSV) were divided into 5 groups: group 1 - the control group, group 2 - treatment with a sclerosant in the amount of 0.3 ml for 30 s, group 3 - treatment with ultrasound at a frequency of 26 kHz and amplitude 40 μm and 0.3-ml sclerosant for 30 s, group 4 - exposure to ultrasound at a frequency of 26 kHz and amplitude 40 μm and 0.3-ml sclerosant for 60 s, group 5 samples were exposed to ultrasound at 26 kHz and amplitude of 40 μm for 60 s. The results of analysing the histological sections of the samples of the 2nd and 3rd groups demonstrated that the degree of alteration in the GSV wall on combined exposure to ultrasound and a sclerosant was 4.5-fold higher as compared with treatment with a sclerosant solution alone. During ultrasound exposure, the maximum temperature of the venous wall of group 5 samples was by 20 °C higher than in samples of group 4. Analysing the histological sections demonstrated a similar pattern of structural alterations of the samples of group 4 and 5, thus suggesting a possibility of controlling the temperature of the venous wall during ultrasound ablation without changing quality of structural lesions. The obtained findings showed a possibility of initiating irreversible dystrophic alterations in the venous wall on exposure to ultrasound by means of combining the mechanisms of chemical, mechanical, and thermal ablation.

Hybrid PCL/CaCO3 scaffolds with capabilities of carrying biologically active molecules: Synthesis, loading and in vivo applications

Designing advanced biomaterials for tissue regeneration with drug delivery and release functionalities remains a challenge in regenerative medicine. In this research, we have developed novel composite scaffolds based on polymeric polycaprolactone fibers coated with porous calcium carbonate structures (PCL/CaCO₃) for tissue engineering and have shown their drug delivery and release in rats. In vivo biocompatibility tests of PCL/CaCO₃ scaffolds were complemented with in vivo drug release study, where tannic acid (TA) was used as a model drug. Release of TA from the scaffolds was realized by recrystallization of the porous vaterite phase of calcium carbonate into the crystalline calcite. Cell colonization and tissue vascularization as well as transplantability of developed PCL/CaCO₃+TA scaffolds were observed. Detailed study of scaffold transformations during 21-day implantation period was followed by scanning electron microscopy and X-ray diffraction studies before and after in vivo implantation. The presented results demonstrate that PCL/CaCO₃ scaffolds are attractive candidates for implants in bone regeneration and tissue engineering with a possibility of loading biologically active molecules and controlled release.

[Ultrasonic examination of the breast adipose grafts after mammoplasty]

AIM

To present the results of PRP-adipose grafts implanatation.

MATERIAL AND METHODS

The study included 25 patients after transplantation of autologous adipose tissue. Autotransplantation was performed to correct volume defects of breast and to restore lost volume after polyacrylamide gel removal in 4 patients; after mastectomy in 6 cases; after complicated replacement using silicone endoprostheses in 11 patients; after previous reduction in 2 cases; after augmentation mammoplasty in 2 cases. Mean age of patients was 42 years. Patients were divided into 2 groups. Group 1 included 12 patients in whom pure adipose tissue was transplanted. Group 2 consisted of 13 patients who received autologous fat with platelet-rich plasma (PRP).

RESULTS

Dynamic ultrasonic monitoring showed early resorption processes (liponecrosis foci) after autologous fat injection. Locally increased vascular pattern of breast tissue is an inflammatory sign requiring anti-inflammatory therapy. PRP-adipose grafts have improved outcomes.

[Expression of matrix metalloproteinases and their inhibitors in the internal carotid artery wall in pathological tortuosity]

The principal morphological sign of fibromuscular dysplasia in pathological tortuosity (PT) of the internal carotid artery (ICA) is the fragmentation of elastic fibers that are degraded by matrix metalloproteinases 2 and 9 (MMP-2, MMP-9). Nevertheless, the role of MMPs and their inhibitors in the pathogenesis of ICA PT remains completely unexplored.

AIM

to investigate the expression of elastin-degrading MMPs and their inhibitors in the wall of the ICA in PT by immunohistochemistry and confocal laser scanning microscopy.

METHODS

Immunohistochemical examination was made using antibodies to MMP-2, MMP-9 and their tissue inhibitors TIMP-1 and TIMP-2. MMP-9 and TIMP-1 levels were determined by confocal laser scanning microscopy.

RESULTS

Immunohistochemical examination revealed a statistically significant predominance of high concentrations of MMP-2 and MMP-9 and a low level of their inhibitor TIMP-1 in ICA PT, while simultaneous obvious accumulation of both markers was most often identified in the control group (p<0.05). Analysis of MMP-2/TIMP-2 and MMP-9/TIMP-2 ratios showed the prevalence of the simultaneously high expression of both proteins in ICA PT and in the control group too. The similar data were also obtained by confocal microscopy: the control group showed elevated MMP-9 and TIMP-1 expressions and the ICA PT control displayed a high proteinase and low inhibitor levels (p<0.05).

CONCLUSION

Elastic fiber fragmentation in ICA PT is due to imbalance between MMPs and their inhibitors; namely, the prevalence of MMP-2 and MMP-9 over their inhibitor TIMP-1, which leads to the degradation of extracellular matrix components, primarily elastin.

[Adhesion molecules and mononuclear cell subpopulations in the coronary and pulmonary arteries of patients with coronary heart disease]

Atherosclerosis is a multifactor disease, in which dysfunction of the endothelium leads to the emergence of its adhesion molecules.

OBJECTIVE

to investigate the expression of the endothelial adhesion molecules PECAM (CD31), ICAM, and VCAM, as well as adherent endothelial T cells and monocytes. The material examined was en face pulmonary and coronary artery samples taken during autopsies (10 men), and en face specimens obtained from the coronary artery fragments taken from coronary heart disease patients during endarterectomy (37 men). This investigation used antibodies to the adhesion molecules ICAM-1, VCAM-1, and PECAM and those to CD3, CD4, CD8 T-cells and CD68 monocytes.

RESULTS

The endothelial cells in the atherosclerotically intact coronary arteries had an elongated shape and were aligned along the blood flow. Those located above atheromas and fibroatheromas changed their shape from elongated to polygonal. Above the fatty streaks and atheromas, the reaction with antibodies to CD31 antigens became weaker at the edge of endothelial cells and disappeared in places. While the atherosclerotic process progressed, the reaction with the CD31 antigen at the edge of endothelial cells was similar in intensity to that on the surface of the endothelium. Adhesion of T cells and monocytes to the endothelium of coronary arteries increased as the atherosclerotic vascular process progressed. T cells and monocytes more often adhered to the endothelium at the sites where the endothelial cells contacted each other.

CONCLUSION

Heterogeneity was found in the endothelial cells: their shape, the expression of adhesion molecules, and the adhesion of lymphocytes and monocytes to them changed during the progression of the atherosclerotic process.

[The structure of the internal carotid artery wall in pathological tortuosity]

OBJECTIVE

to study a change in the content of main components of the internal carotid artery (ICA) wall in pathological tortuosity (PT) resulting from fibromuscular dysplasia, using immunohistochemistry and confocal laser scanning microscopy.

MATERIAL AND METHODS

Immunohistochemical (IHC) analysis using antibodies to elastin, collagen types I and III, and smooth muscle actin was made. The levels of elastin and matrix metalloproteinase 9 (MMP-9) were determined by confocal laser scanning microscopy. The relative area of expression and the area of co-location of these markers were measured.

RESULTS

IHC examination of the expression of elastin revealed that the patients with PT of ICA had its higher content than the controls, but they were observed to have fiber fragmentation. Comparison of collagen types I and III expressions showed no significant differences between the groups. The found significantly lower smooth muscle actin expression in the patients with PT of ICA than in the controls was suggestive of the decreased levels of smooth muscle cells. Confocal microscopy analysis showed high elastin and low MMP-9 expressions in the control group and, on the contrary, low elastin and high proteinase levels in the PT group (р<0.05).

CONCLUSION

One of the causes of PT is impairment in vascular elastic properties due to the destruction of elastic fibers and to their fragmentation, as well as to the decreased count of smooth muscle cells, which in turn causes enhanced MMP-9 activity and tissue matrix degradation.

Synthesis and magnetic properties of the chromium-doped iron sulfide Fe1−xCrxS single crystalline nanoplates with a NiAs crystal structure

Chromium-doped pyrrhotite Fe_1−xCr_xS nanoparticles have been synthesized. The specific magnetic properties important for applications in technical devices can be tuned by chromium doping.

[Surgical treatment for fibro-muscular dysplasia]

AIM

To present the results of surgical treatment of patients with fibro-muscular dysplasia.

MATERIAL AND METHODS

Our experience of treatment of 144 patients with fibro-muscular dysplasia is presented in the article. 118 (82%) patients suffered from stenoses, kinking and aneurysms of internal carotid arteries, 21 (14.5%) patients had lesion of renal arteries, 5 (3.5%) patients--azygous visceral arteries lesion. It was performed 157 reconstructive operations in the Department of cardiac surgery N(o)1 (aortic surgery) of acad. B.V. Petrovskiy Russian Research Center for Surgery for the period from 1993 to 2014. Clinical features of fibro-muscular dysplasia, surgical tactics and technique depending to the localization of lesion are described.

RESULTS

Immediate and remote surgical results were studied. There were no any severe intraoperative and immediate postoperative complications. Follow-up after carotid surgery was 104.49±68.68 months (6-247 months). Strokes were not observed. Hemodynamically insignificant re-stenoses were diagnosed in 7 (5.5%) cases. Mean follow-up after renal reconstructions was 139.24±63.96 months (28-239 months). Persistent blood pressure normalization was achieved in 11 (73.3%) cases. Patients with azygous visceral arteries dysplasia have been examined for the period of 103.4±69.6 months (35-205 months). There were no recurrent aneurysms and abdominal ischemia in the remote postoperative period. Hospital and remote mortality was absent. Based on own experience and colleagues' data we consider that surgical treatment of patients with some forms of fibro-muscular dysplasia provides satisfactory results if advisable strategy is selected.

[Sevoflurane optimal dosage estimation for myocardium pharmacological postconditioning: an experimental study]

We estimated the optimal dosage of inhalation anesthetic sevoflurane, for the maximum cardioprotective effect with minimal angioparalytic action. 25 pigs were included in this study, they were divided into 5 groups, depending on the sevoflurane dosage used for pharmacological postconditioning (PPC): control group - PPC has't been conducted, a group of PPC 0.5 - sevoflurane PPC in a dose of 0.5 V%, a group of PPC 1.0 - sevoflurane PPC in a dose of 1.0 V%, a group of PPC 1.5 - sevoflurane PPC in a dose of 1.5 V%, a group of PPC 2.0 - sevoflurane PPC in a dose of 2.0 V%, a group of PPC 2.5 - sevoflurane PPC in a dose of 2.5 V%. Ischemia was simulated by left coronary artery crossclamping. Further PPC was held according to the following Protocol: 20 min before left coronary artery clamp off and first 20 min of reperfusion sevoflurane was given into CPB circuit. Myocardial ischemia period was 60 min in all groups. It was found and experimentally proved that the optimal sevoflurane dosage for PPC is 2 V%

A comparative study of the aortic wall in patients with Marfan's syndrome and Erdheim's disease

The materiel of intraoperative biopsies (378) and autopsies was used to study the morphology of the aortic wall in patients with Marfan's syndrome (62) and Erdheim's disease (133). Histological, histochemical and electron microscopy research methods were employed with an assay of the results obtained. It has been demonstrated that in connective tissue dysplasia in the aorta, the histological structure of the intima undergoes substantial changes alongside the pathology of the tunica media. It is marked by the formation of a focal and diffuse thickening with the predominance of the interstitial substance, rich in glycosaminoglycans, and of a small amount of fibrous structures. The morphological signs of the impairment of endothelial permeability (vacuolisation of cytoplasm, thinning of its peripheral portions and basal membrane, expansion of intercellular fissures) are identifiabe, which leads to the disorder of aortic wall metabolism and early development of atherosclerosis. The changes in the intima together with the pathology of the tunica media ere predisposing factors of aneurysm formation, dissection and rupture of the aorta.