9 results on '"Stoyneva Z"'
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2. Laser Doppler-recorded venoarteriolar reflex in Raynaud's phenomenon
- Author
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Stoyneva, Z.
- Published
- 2004
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3. CURRENT ASPECTS IN THE DIFFERENTIAL DIAGNOSIS OF ANGIONEUROTIC EDEMA..
- Author
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Ilkova, P., Stoyneva, Z., and Dimitrova, N.
- Subjects
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ANGIONEUROTIC edema , *DIFFERENTIAL diagnosis , *HISTORY of medicine , *PHYSICIANS , *DIAGNOSIS - Abstract
Angioedema is a disease characterized by various triggers and an increasing prevalence. The great Greek physician Hippocrates (377-460 BC), considered one of the most outstanding figures in the history of medicine and "Father of the Western Medicine," already used the term oídēma to describe „swelling of organs“. It took many centuries later until the first description of angioedema as a distinct medical entity was minted by Quinсke in 1882. The contemporary perception, defines аngioedema as a transient swelling of the skin or submucosal surface due to increased vascular permeability of small venules. The overlying skin may be normal or mildly erythematous. Over time, many causes and factors that cause or trigger angioedema have been discussed. There are two main types of angioedema without urticarial (histaminergic and nonhistaminergic) as the role of histamine in the pathogenesis of the disease is crucial. Angioedema is a frequent clinical condition that sometimes can be life-threatening. Different types of angioedema can be challenging to distinguish clinically. However, establishing a correct diagnosis is critical as different forms of angioedema require distinct treatment approaches. Implementation of contemporary differential diagnostic approaches could be a prerequisite for an accurate diagnosis, which secures appropriate management strategies are possible. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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4. Microvascular reactivity to thermal stimulation in patients with diabetes mellitus and polyneuropathy.
- Author
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Stoyneva, Z., Velcheva, I., Antonova, N., and Titianova, E.
- Subjects
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MICROCIRCULATION disorders , *NEUROPATHY , *DIABETES , *VASOCONSTRICTORS , *VASODILATORS - Abstract
The study aimed to investigate local thermally induced microvascular reactivity in patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM) and polyneuropathy and to compare it with healthy controls. A hundred and fourteen subjects were investigated divided into 3 groups: 1st group - 20 patients with T1DM; 2nd group - 50 patients with T2DM; 3rd group - 44 healthy controls. The skin perfusions of the first tiptoe were monitored by laser Doppler flowmetry during thermal test. The initial (PUi) and basal perfusions at 32°C (PUb) tended to be higher in the DM groups and the PUb of T1DM group was higher compared with the healthy subjects. The perfusion responses to heating were attenuated in the patients compared with the controls. The calculated vasodilator heat-induced indices were significantly lower and the vasoconstrictor indices during relative cooling in the recovery period were significantly higher in DM patients related to the healthy subjects. The reduced cutaneous microvascular responses to local thermal stimulation in the plantar sides of the toes of both T1DM and T2DM patients with polyneuropathy were similar to those found by previous studies in other investigated sites of glabrous and nonglabrous skin of patients with DM. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
5. Venoarteriolar reflex responses in diabetic patients.
- Author
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Stoyneva, Z., Velcheva, I., Antonova, N., Titianova, E., and Koleva, I.
- Subjects
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TYPE 2 diabetes , *NEUROPATHY , *BODY mass index , *SUPINE position , *PEOPLE with diabetes - Abstract
The aim of this study was to investigate the venoarteriolar reflex (VAR) responses in type 1 (T1DM) and type 2 (T2DM) diabetes mellitus (DM) with polyneuropathy and to estimate their relationship with age, DM duration, initial cutaneous temperature and body mass index. Four groups of subjects were investigated: 1st group - 20 patients with T1DM; 2nd group - 50 patients with T2DM; 3rd group of 20 healthy subjects with similar age and body mass index (BMI) to the T1DM group; 4th group (Control2) of 24 healthy subjects adjusted by age and BMI to the T2DM group. The cutaneous perfusions of the big toe pulp were monitored as baseline perfusions at a temperature of 32°C in supine and sitting position with hanging legs and back in supine position. Loss of venoarteriolar reflex responses was established in 75% of T1DM patients, 78% of T2DM patients and in none of the investigated healthy controls. Reduced venoarteriolar perfusion responses were established in both T1DM and T2DM patients with polyneuropathy compared with healthy subjects. Reliable positive associations between VAR responses and the age, DM duration and initial cutaneous temperature were found. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
6. Current pathophysiological views on vibration-induced Raynaud’s phenomenon
- Author
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Stoyneva, Z., Lyapina, M., Tzvetkov, D., and Vodenicharov, E.
- Subjects
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AUTONOMIC nervous system , *ENDOTHELINS - Abstract
This review attempts to summarize and discuss contemporary pathogenetic views on vibration-induced Raynaud’s phenomenon assuming its multifactorial etiology. An increase in central and peripheral sympathetic nervous activity is discussed based on different physiological indicators of autonomic dysfunction and sympathetic hyperactivity. Local acral vasodysregulation is considered. Receptor and nerve endings dysfunction presented with predominance of α2-receptor function in the digital arteries and neuronal loss in those digital cutaneous perivascular nerves containing calcitonin gene-related peptide result in deficiency of endogenous release of this powerful vasodilator. Endothelial damage and dysregulation induced by vibration and increased shear stresses are demonstrated by the elevated plasma level of thrombomodulin and of von Willebrand factor and reduced endothelium-dependent vasodilator responses. The concentrations of endothelin-1 are high, the highest being in most advanced stages. Decreased plasma thiol level, indicating increased production and activity of free radicals, contribute to vasospastic paroxysms in vibration white finger patients. Dysbalance of local vasoactive factors with opposing effects on vascular smooth muscle like endothelin and nitric oxide, endothelin and calcitonin gene-related peptide, nitric oxide and superoxide anion are discussed. Disturbed smooth muscle response is supposed. Changes in hemostasis, fibrinolysis and hemorrheology, activation of blood cells with erythrocyte hyperaggregation and red cell hypodeformability, platelet aggregation with increased release of vasoconstricting thromboxane A2 and serotonin as well as leukocyte activation, entrapment within capillaries and post-capillary venules and increased reactive oxygen species and lysosomal lytic enzymes release might also contribute to digital vasospasms and tissue damage. Elevated soluble intercellular adhesion molecule-1 levels involved in the adherence of leukocytes to endothelium and to other leukocytes have been found in patients with hand–arm vibration syndrome. [Copyright &y& Elsevier]
- Published
- 2003
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7. Spatial heterogeneity in the time and frequency properties of skin perfusion.
- Author
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Sorelli M, Stoyneva Z, Mizeva I, and Bocchi L
- Subjects
- Healthy Volunteers, Humans, Laser-Doppler Flowmetry, Skin Temperature, Time Factors, Wavelet Analysis, Microcirculation, Skin blood supply
- Abstract
Pathological alterations of the microcirculatory system can be identified by measuring the temporal and spectral properties of laser Doppler flowmetry (LDF) signals acquired on the skin, and their changes following physiological stimulation. A wide range of stimulation protocols and measurement locations is observed in literature. Researchers often use non-invasive stimulation techniques, such as post-occlusive hyperaemia, cold tests, and local heating. As concerns the stimulation/recording sites, the forearm, fingers, and toes are typically selected to conduct microcirculation studies. However, recent clinical investigations showed that different anatomical sites present dissimilar blood flow patterns. Therefore, studies involving the comparison of LDF data, obtained from various anatomical locations, and thus subjected to the intrinsic heterogeneity of the microcirculation, may be methodologically inaccurate. At the moment, no consensus has been reached upon the optimal measurement location, the stimulation pattern, and the physiological parameters of interest. The aim of this study is to quantitatively characterize the heterogeneity of the peripheral perfusion at different anatomical locations: the index finger, the forearm, and the hallux. The skin microvascular system exhibits a complex vasodilatory response in the temporal domain, upon local heating. This physiological reactive hyperaemia comprises two effects: a fast transient response, correlated to neural activation, named axon reflex, followed by a slower hyperaemic plateau, mediated by the release of nitric oxide. In this work, we compare the vasodilatory reaction to heating at the different sites, based on a parametric representation of the perfusion signal. Moreover, skin blood flow is characterized by several components fluctuating at different time scales. Time-frequency decomposition of LDF signals allows to quantitatively evaluate the relative contribution of known physiological mechanisms to the regulation of the peripheral circulation. For this reason, we analyze the wavelet transform coefficients of LDF signals at baseline, to assess potential spatial heterogeneities of the perfusion power spectra among the aforementioned anatomical locations.
- Published
- 2017
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8. Postocclusive reactive hyperemia in hand-arm vibration syndrome.
- Author
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Stoyneva Z
- Subjects
- Adult, Female, Fingers blood supply, Humans, Laser-Doppler Flowmetry, Male, Middle Aged, Occupational Diseases physiopathology, Scleroderma, Systemic physiopathology, Skin Temperature, Hand-Arm Vibration Syndrome physiopathology, Hyperemia physiopathology, Raynaud Disease physiopathology
- Abstract
Objectives: To assess laser Doppler-recorded postocclusive reactive hyperemic responses in vibration-induced Raynaud's phenomenon and compare it with primary and secondary to sclerodermy Raynaud's phenomenon., Material and Methods: Thirty patients with vibration-induced Raynaud's phenomenon and 30 healthy controls and patients with primary and secondary to sclerodermy Raynaud's phenomenon were investigated. Fingerpulp skin blood flow was monitored by laser Doppler flowmetry during postocclusive reactive hyperemia test., Results: Lower initial perfusion values were established in all the patients with Raynaud's phenomenon compared to the healthy controls (p < 0.0001). The postocclusive reactive hyperemic peak was lower in all the Raynaud's phenomenon groups compared to the controls (p < 0.0001). The postocclusive and basal perfusions were lower in the secondary Raynaud's phenomenon groups compared to the control and the primary Raynaud's phenomenon groups (p < 0.0001). The velocities to postocclusive hyperemic peak were lower in all the Raynaud's phenomenon patients (p < 0.0001), so were in the vibration-induced (p < 0.002) and the sclerodermy Raynaud's phenomenon (p < 0.004) groups in relation to the primary Raynaud's phenomenon group. The perfusion values and the velocities were significantly influenced by the initial superficial skin temperatures and perfusions, while the velocities were dependent also on gender, and the hyperemic peak on age., Conclusions: Postocclusive reactive hyperemia is abnormal in all Raynaud's phenomenon patients. Laser Doppler-recorded reactive hyperemia test contributes to diagnosing Raynaud's phenomenon and has proved to be valuable for group analysis. The applied method is not sensitive enough to discriminate adequately the type of Raynaud's phenomenon among individual cases., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)
- Published
- 2016
- Full Text
- View/download PDF
9. Hemorheology and vascular reactivity in patients with diabetes mellitus type 2.
- Author
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Velcheva I, Damianov P, Antonova N, Stoyneva Z, Mantarova S, and Dimitrova V
- Subjects
- Adult, Aged, Blood Flow Velocity, Body Mass Index, Cerebrovascular Circulation, Diabetes Mellitus, Type 2 physiopathology, Diabetic Angiopathies blood, Diabetic Angiopathies physiopathology, Diabetic Neuropathies blood, Erythrocyte Indices, Female, Fibrinogen analysis, Humans, Lipids blood, Male, Middle Aged, Middle Cerebral Artery diagnostic imaging, Skin blood supply, Toes blood supply, Ultrasonography, Diabetes Mellitus, Type 2 blood, Hemorheology, Posture physiology
- Abstract
The study aimed to investigate the hemorheological parameters in patients with diabetes mellitus type 2 and to estimate their relationship with the cerebral and cutaneous blood flow and their responses to postural changes. The basic hemorheological constituents: hematocrit (Ht), fibrinogen (Fib), whole blood (WBV) and plasma viscosity (PV) were examined in 20 patients with diabetes mellitus type 2 and in 10 healthy age and sex matched controls. Blood flow velocity in the middle cerebral artery (MCA) was measured by transcranial Doppler monitoring at rest and during 5-min head-up tilt. Also laser Doppler-recorded tiptoe skin blood flow was investigated and venoarteriolar reflex perfusion responses to postural impact was monitored. Significant increase of Fib and WBV at shear rates of 0.0237 s(-1) to 128.5 s(-1) in the patients in comparison to controls was found. The postural challenge caused decrease of the cerebral blood flow velocity and increase of the resistance index (RI) in the diabetic patients. The initial mean skin perfusion values of the tiptoes and the venoarteriolar constriction response indices were significantly higher in the diabetes group. In the patients with diabetes mellitus type 2 the increased blood viscosity values were associated with impaired cerebrovascular and peripheral vascular responces.
- Published
- 2011
- Full Text
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