Clinical Hemorheology and Microcirculation - Volume 49, issue 1-4

Authors: Velcheva, Irena | Damianov, Petar | Antonova, Nadia | Stoyneva, Zlatka | Mantarova, Stefka | Dimitrova, Valentina

Article Type: Research Article

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. Show more

Keywords: type 2 diabetes mellitus, hemorheological parameters, transcranial Doppler, head-up tilt, laser Doppler flowmetry, venoarteriolar reflex

DOI: 10.3233/CH-2011-1501

Citation: Clinical Hemorheology and Microcirculation, vol. 49, no. 1-4, pp. 505-511, 2011

Authors: Velcheva, Irena | Damianov, Petar | Mantarova, Stefka | Antonova, Nadia

Article Type: Research Article

Abstract: Our study aimed to investigate the relationship between hemorheological parameters and heart rate variability (HRV) in patients with diabetes mellitus type 2. Hemorheological variables, including hematocrit (Ht), fibrinogen (Fib), whole blood (WBV) and plasma viscosity (PV) at shear rates of 0.0237 s−1 to 128.5 s−1 were examined in 20 patients with diabetes mellitus type 2 and in 10 control subjects. They all underwent non-invasive short-term monitoring of heart rate at rest and after passive head-up tilt. Measurement of the R-R intervals and calculation of the time domain parameters and the power spectral data were performed by our softwear, …using fast Fourier transformation. Significant increase of Fib and WBV in the patients in comparison to controls was found within the range of shear rates 0.0237 s−1 to 128.5 s−1 . In the diabetic patients parallel decrease of the total power (TP), the low frequency spectral power (LF) and of the mean RR and mild increase of the low frequency-high frequency ratio (LF/HF) at rest were established. This tendency was kept after the passive tilt. In patients with diabetes mellitus type 2 the increased blood viscosity was associated with reduced HRV. Show more

Keywords: type 2 diabetes, hemorheological parameters, heart rate variability

DOI: 10.3233/CH-2011-1500

Citation: Clinical Hemorheology and Microcirculation, vol. 49, no. 1-4, pp. 513-518, 2011

Authors: Gehmert, Sanga | Gehmert, Sebastian | Bai, Xiaowen | Klein, Silvan | Ortmann, Olaf | Prantl, Lukas

Article Type: Research Article

Abstract: MSCs reside within their niche and pathologic conditions such as hypoxia and inflammation can lead to mobilization and migration of Mesenchymal Stem Cells (MSCs). Xenograft animal models using immundeficient mouse demonstrated that MSCs migrated to and distributed throughout the tumors and were found to engraft into tumor stroma and vasculature. In contrast, MSCs primarily incorporated within tumor-capsula and did not invade the tumor using immuncompetent tumor allograft models. Here we hypothesize that MSCs migrate primarily towards an inflammatory milieu independent of the underlying biological process causing the inflammation. Murine MSCs (mASCs) were isolated from subcutaneous fat tissues and transduced at …passage 0 with lentiviral vector encoding green fluorescent protein (GFP) and luciferase reporter. Breast cancer was established in BALB/c mice by subcutaneous injection of 4T1 cells into the left mammary fat pad. E. coli were injected subcutaneously in the right 4th mammary fat pad. After 24 h luciferase labeled mASCs were administered intraperitoneal (i.p.) and monitored with IVIS Bioluminescence camera for 72 hours. Control group received either tumor implantation or E. coli injection. MSCs significantly migrated towards tumor when compared to control mice without tumor or inflammatory process. However, mASCs injected in 4T1 bearing mice with E. coli only migrated towards the bacterial inflammatory focus. Our results substantiate the notation the MSCs response predominantly to the inflammatory milieu created by bacteria or tumor rather than specifically to the tumor. Thus, it is suggested that the migration of MSCs in immunodeficient mice depends on cancer secreted cytokines due to the lack of the inflammatory response by the immune system. Therefore, in vivo studies investigating the role of MSCs in tumor angiogenesis have shown controversy results and should be interpreted with caution in terms of tumor secreted cytokine dependent stem cell migration. Show more

Keywords: Mesenchymal stem cells, tumor angiogenesis, breast cancer, migration, immunsystem

DOI: 10.3233/CH-2011-1502

Citation: Clinical Hemorheology and Microcirculation, vol. 49, no. 1-4, pp. 519-526, 2011

Authors: Stock, K.F. | Klein, B.S. | Cong, M.T. Vo | Regenbogen, C. | Kemmner, S. | Büttner, M. | Wagenpfeil, S. | Matevossian, E. | Renders, L. | Heemann, U. | Küchle, C.

Article Type: Research Article

Abstract: Background and purpose: Beyond the medical history, the clinical exam and lab findings, non-invasive ultrasound parameters such as kidney size and Doppler values (e.g. the resistive index) are important tools assisting clinical decision making in the monitoring of renal allografts. The gold standard for the diagnosis of renal allograft dysfunction remains the renal biopsy; while an invasive procedure, the justifiable necessity for this derives from its definitive nature a requirement beyond the synopses of all non-invasive tools. “Acoustic Radiation Force Impulse Imaging”(ARFI)-quantification is a novel ultrasound-based technology measuring tissue elasticity properties. So far experience related to this new method has …not been reported in renal transplant follow-up. The purpose of this study was to evaluate changes in ARFI-measurements between clinically stable renal allografts and biopsy-proven transplant dysfunction. Methods: We employed “Virtual Touch™ tissue quantification” (Siemens Acuson, S2000) for the quantitative measurement of tissue stiffness in the cortex of transplant kidneys. We performed initial baseline and later disease-evaluative ultrasound examinations in 8 renal transplant patients in a prospective study design. Patients were first examined during stable allograft function with a routine post-transplant renal ultrasound protocol. A second follow-up examination was carried out on subsequent presentation with transplant dysfunction prior to allograft biopsy and histological evaluation. All patiens were examined using ARFI-quantification (15 measurements/kidney). Resistive indices (RI) were calculated using pulsed-wave Doppler ultrasound, and transplant kidney size was measured on B-mode ultrasound images. All biopsies were evaluated histologically by a reference nephropathologist unaware of the results of the ultrasound studies. Histopathological diagnoses were based on biopsy results, taking clinical and laboratory findings into account. Finally we calculated the relative changes in ARFI-quantification, resistive indices and the absolute change of kidney size on a percentage basis at these defined assessment times and compared the results with the final pathologic diagnosis. Results: Histological results enumerated five cases of acute T-cell-mediated rejection, one case of calcineurin inhibitor toxicity and two cases of acute tubular necrosis. Calcineurin inhibitor toxicity and acute tubular necrosis were subsumed as “other pathologies”. Mean ARFI-values showed an average increase of more than 15% percent in transplants with histologically proven acute rejection whereas no increase was seen in transplants with other pathologies. Mean RI-values showed no increase either in the diagnostic group of acute rejection, nor in the group with other pathologies. Kidney size showed a mean absolute increase of 0.5 centimetres in allografts with acute rejection, whereas a mean decrease of 0.17 centimetres was seen in the group with other pathologies. Conclusion: As shown before in other studies, RI values andkidney size are of doubtful utility in the evaluation of kidneyallograft dysfunction. ARFI-based elasticity measurement showspromise as a complementary non-invasive parameter in follow-ondiagnosis of renal allograft rejection. Show more

Keywords: Ultrasonography, elasticity imaging techniques, kidney, kidney transplantation, Doppler ultrasonography, ARFI, graft rejection

DOI: 10.3233/CH-2011-1503

Citation: Clinical Hemorheology and Microcirculation, vol. 49, no. 1-4, pp. 527-535, 2011

Authors: Helck, A. | D'Anastasi, M. | Notohamiprodjo, M. | Thieme, S. | Reiser, M. | Clevert, D.A.

Article Type: Research Article

Abstract: Purpose: To evaluate the potential benefit of three-dimensional ultrasound in the assessment of renal lesions. Materials and methods: 21 patients with unclear renal findings were prospectively included in the study. Every patient was examined using two-dimensional (2D) ultrasound (US), X-plane technique (simultaneous display of main image and second image at a plane at right angles to the first), and real time three-dimensional (3D) US. The imaging model used were standard gray scale-, duplex- and contrast-enhanced ultrasound (CEUS). All acquisitions were compared to each other with regard to image quality and identifiability of renal lesions. Additionally, when using the X-plane technique …the quality of the first and the second image were analysed separately. The assessment was done using a subjective 6 point scale (1 = best). Results: All acquisitions were successfully performed and no patient had to be excluded. Image quality of real time 3D-US (score: 2.4 ± 0.73) was slightly inferior to 2D-US and X-plane technique (main image) with a score of 2.2 ± 0.43 and 2.2 ± 0.5, respectively. The image quality of second image in the X-plane mode –due to a lower spatial resolution- was lower with a score of 3.2 ± 0.5. Real time 3D-US and X-plane technique allowed for better identifiability (score: 1.4 ± 0.59 and 1.9 ± 0.53) of renal lesions compared to 2D-US (score: 2.5 ± 0.6). The most marked difference was observed between the simultaneous use of real time 3D-US and X-plane technique versus 2D-US in case of renal cell carcinoma, especially with regard to extra-capsular tumor extension (score: 1.6 ± 0.52, 1.8 ± 0.71, and 3.0 ± 0.52, respectively). Conclusion: Assessment of renal lesions using real time 3D-US is feasible and improves the identifiability of renal lesions. Show more

Keywords: Renal lesions, real-time 3D, three-dimensional ultrasound, X-plane, image quality

DOI: 10.3233/CH-2011-1504

Citation: Clinical Hemorheology and Microcirculation, vol. 49, no. 1-4, pp. 537-550, 2011

Article Type: Correction

Abstract: Erratum to [Clinical Hemorheology and Microcirculation 48 (1–3) (2011), 29–40] DOI 10.3233/CH-2011-1406

DOI: 10.3233/CH-2011-1511

Citation: Clinical Hemorheology and Microcirculation, vol. 49, no. 1-4, pp. 551-551, 2011

Article Type: Other

Citation: Clinical Hemorheology and Microcirculation, vol. 49, no. 1-4, pp. 553-560, 2011