Determination of cerebral blood flow dynamics during retrograde cerebral perfusion using power M-mode transcranial Doppler

BACKGROUND: Retrograde cerebral perfusion (RCP) during profound hypothermic circulatory arrest has been used as an adjunct for cerebral protection for repairs of the ascending and transverse aortic arch. Transcranial Doppler ultrasound has been used to monitor cerebral blood flow during RCP with varying success. The purpose of this study was to characterize cerebral blood flow dynamics during RCP using a new mode of monitoring known as transcranial power motion-mode (M-mode) Doppler ultrasound. METHODS: Data on pump-flow characteristics and patient outcomes were collected prospectively for patients undergoing ascending and transverse aortic arch repair. Retrograde cerebral perfusion during profound hypothermic circulatory arrest was used for all operations. Intraoperative cerebral blood flow dynamics were monitored and recorded using transcranial power M-mode Doppler ultrasound. RESULTS: Between August 2001 and March 2002, we used transcranial power M-mode Doppler ultrasound monitoring for 40 ascending and transverse aortic arch repairs during RCP. Mean RCP time was 32.2 +/- 13.8 minutes. Mean RCP pump flow and RCP peak pressure for identification of cerebral blood flow were 0.66 +/- 0.11 L/min and 31.8 +/- 9.7 mm Hg, respectively. Retrograde cerebral blood flow during RCP was detected in 97.5% of cases (39 of 40 patients) with a mean transcranial power M-mode Doppler ultrasound flow velocity of 15.5 +/- 12.3 cm/s. In the study group, 30-day mortality was 10.0% (4 of 40 patients). The incidence of stroke was 7.6% (3 of 40 patients); the incidence of temporary neurologic deficit was 35.0% (14 of 40 patients). CONCLUSIONS: Transcranial power M-mode Doppler ultrasound consistently demonstrated retrograde middle cerebral artery blood flow during RCP. Transcranial power M-mode Doppler ultrasound can provide optimal RCP with individualized settings of pump flow.     

A detailed procedure and dissection guide for the isolation of spiral ganglion cells of the guinea pig for electrophysiological experiments

In the present study step-by-step instructions are provided for a preparative technique employed for the removal of the spiral ganglion from the inner ear of the guinea pig. Removal of the temporal bone is followed by opening of the bulla and excision of the modiolus. All major steps of the technique are illustrated with photographs. A procedure to obtain surviving, acutely separated spiral ganglion neurones is also described. By this procedure small tissue pieces are removed from the modiolus which contain the spiral ganglion neurones. The tissue fragments then undergo a mild enzyme treatment (collagenase and pronase). After the enzyme exposure, the tissue pieces are gently triturated, and the isolated cells are allowed to settle. Poly-D-lysine ensured the firm attachment of the spiral ganglion cells to the cover-slips. The application of this adhesive coating seemed to be desirable in functional studies when microelectrode techniques and/or rapid exchange of the extracellular solution were employed.     

Radioguided excision of non-palpable breast lesions with simultaneous sentinel lymph node biopsy

As a result of mammographic screening nonpalpable breast lesions are found with increasing frequency. The surgical management of these lesions presents two main problems: (1) How to localize the lesion pre- and intraoperatively; (2) What should be the extension of the axillary dissection for malignant lesions. This study is aimed to evaluate the technical feasibility of radioguided excision of nonpalpable breast lesions and the possibility of performing simultaneous sentinel lymph node biopsy for malignant lesions. Radioguided breast excisions have been performed in our Department since November 2000. The basis of this method is that radioisotope labelled colloid is injected into the lesion under stereo tactic or sonographic guidance. A gamma-probe is used intraoperatively to locate the lesion and guide its excision. Dual agent guided technique is used for sentinel lymph node biopsy. Radioguided breast excision was performed on 85 patients (93 lesion) till February 2002. The localization and excision were successful in 84 patients (92 lesions) (99%). Multifocal lesions were successfully localized and excised in 7 patients. There were 61 parenchyma lesions (66%) and 31 microcalcifications (34%). Localization was performed under sonographic guidance in 44 patients (52%) and under stereotactic guidance in 40 patients (48%). There were 25 benign (27%) and 67 malignant (73%) lesions. Second surgical procedure (mastectomy) was needed in 4 patients (6.5%) because of histologically incomplete excision. Sentinel lymph node biopsy was performed in 50 patients. The biopsy was successful in 45 patients (90%). The sentinel lymph node was histologically positive in 2 patients (4.4%). Radioguided localization with the intraoperative use of a gamma-probe is an easy, rapid and highly accurate technique for removing nonpalpable breast lesions and allows simultaneous sentinel lymph node biopsy for malignant lesions.     

Failure of Helicobacter pylori eradication--suggestions for further therapy

Success of first H. pylori eradication attempts in the literature is around 80-90% and based on urea breath test of 1027 patients in Hungary is 75%. Repeated eradication attempts are needed in 10-25% of cases. In the clinical practice in Hungary second and third eradication attempts were successful only in 36% and 20% of cases. To improve efficacy the following suggestions has to be kept in mind: 1. Do not repeat the same combination if the first attempt is failed. 2. After failure of the first PPI + amoxicillin + clarithromycin triple therapy, either the quadriple therapy (PPI + tetracycline + metronidazole + bismuth) or the replacement of PPI with ranitidine bismuth citrate in the triple therapy is suggested. 3. If PPI + amoxicillin + metronidazole/tinidazole therapy fails, the metronidazole/tinidazole can be replaced by clarythromycin. 4. Do not start with clarithromycin + metronidazole/tinidazole therapy. 5. In case of uncertain previous therapies and for third eradication treatment send the patient to specialist. Rifabutin-based combinations seem to be effective, but the use of them in general practice is not advised due to the possible development of mycobacterium tuberculosis resistance.     

Immunobiology of dendritic cells and their application in clinical practice

INTRODUCTION: Dendritic cells play a central role in the regulation of the immune responses towards cellular or humoral immunity. Several types of dendritic cells can be distinguished, which originate from different hematopoietic lineages, and differ from each other in function, morphology and localization within the organism. Immature dendritic cell-precursors originate from bone marrow haemopoietic stem cells, circulate in blood system and reach peripheral tissues, where they differentiate into active antigen capturing and processing cells. They have further maturation by the effect of adequate signals (antigen stimuli and inflammatory cytokines) and migrate into secondary lymphoid organs, presented cell surface MHC molecules-linked peptides from antigens which they have captured and processed, to T lymphocytes, induce immune reaction by T cell activation. Apart from the fact that dendritic cells as professional antigen presenting cells are essential to induction T cell-mediated immune responses, they influence activation and function of B lymphocytes and effector cells of natural immune system by cytokines and cell-cell interactions. CONCLUSIONS: Complex regulatory function of dendritic cells make a possibility for artificial alteration of immune processes by modification of dendritic cells: direct against definitive antigens, increase or decrease their intensity, hereby we can accomplish the immunotherapy of different diseases such as tumors, infection, autoimmune diseases, transplants' rejection.     

Effect of imatinib treatment of gastrointestinal stromal tumors

INTRODUCTION: Advanced malignant gastrointestinal stromal tumours are practically resistant to further radio- or chemotherapy. These tumours are characterized by the presence of C-KIT (a transmembrane tyrosin kinase) mutation which can be specified by CD117 expression. Imatinib (2-fenilaminopirimidine) is a selective inhibitor of the mutated C-KIT. AIM: The purpose of our study was to determine the potential antitumour effect of imatinib in patients with gastrointestinal stroma tumour patients. MATERIALS AND METHODS: An open, non-randomized trial was performed involving 38 patients each of which had received/metastatic disease associated with CD117 positivity. Consecutively daily doses of 400-600 mg imatinib was administered orally to the patients. The evaluation was carried out on 37 patients in a form of an interim analysis. RESULTS: After a 3-18 months observation period 1 complete, 19 partial remissions and 10 static diseases could be registered (78%), in association of only grade 1-2 toxicity. CONCLUSIONS: The imatinib treatment improved the quality of life of the patients with gastrointestinal stroma tumour and their life expectancy became considerably prolonged. Further follow-up of the patients as well as design of a prospective, randomized trial on a larger patient material is urgently needed.     

Effect of vinpocetin on the hemorheologic parameters in patients with chronic cerebrovascular disease

INTRODUCTION: Data collected from large number of multicenter, randomized trials in acute and chronic stroke patients provide evidence, that incidence and high mortality of cerebrovascular disorders can be decreased mainly by prevention and that the effectiveness of acute stroke treatment is limited. The terminology of "chronic cerebrovascular diseases" involves many pathologic entities and often atypical clinical symptoms refer to the focal or global hypoperfusion of the brain. However, hemorheological disturbances seem to be important factors of the complex pathomechanism. Vinpocetine has successfully been used in the treatment of cerebrovascular diseases, the part of the mechanism of action are the favourable rheological effects demonstrated after oral administration in more previous studies. AIMS AND METHODS: In this study the hemorheological changes after administration of small (30 mg/day) and high dose (increased to 70 mg/day) intravenous vinpocetine for 7 days in 30 patients in chronic phase of ischemic cerebrovascular disease were investigated. RESULTS: High dose parenteral vinpocetine treatment significantly (p < 0.05-0.005) decreased the hematocrit, the whole blood and plasma viscosity and red blood cell aggregation compared to the values before the treatment. Only red blood cell aggregation was improved significantly (p < 0.05) by small dose treatment. CONCLUSION: This study and other hemorheological studies in cerebrovascular patients demonstrated persistent rheological abnormalities despite the preventive therapy. The beneficial rheological effect of high dose parenteral vinpocetine indicates the use of this drug in the treatment of chronic cerebrovascular diseases.     

Possibilities of monitoring oxidative damage and its clinical aspects

In their earlier work the authors reviewed some methods, which appeared to be suitable for monitoring the redox-status of the human organism and, therefore, may be applied under routine clinical laboratory circumstances. This possibility can lead to a new perspective to set up epidemiological studies in different populations in order to investigate connecting points between the manner of life, alimentary customs (especially consumption of antioxidants), and the risk of chronic or acute illnesses. In this review the authors surveyed different methods for the measurements of end products (lipids, proteins, nucleic acids) produced by cells and tissues through oxidative injury, caused by the free radicals. These methods have already served the work of scientists for many years, helping them to obtain experience about the pathomechanisms of different diseases. With the help of these measurements it could be possible to monitor the results of medical therapy or surgical treatments, or in the field of chronic illnesses e.g. diabetes, to predict the possible development of late complications.     

Effects of cardiovascular risk factors on hemorheologic parameters in cerebrovascular patients

INTRODUCTION: Hemorheological factors are of significance in the determination of flow characteristics of blood and play an important role in the pathogenesis of cerebrovascular diseases. AIMS AND METHODS: In this study the changes of rheological factors--hematocrit (Hct), plasma fibrinogen concentration (PFC), whole blood (WBV) and plasma viscosity (PV), red blood cell aggregation (AI) and deformability and the association between these parameters and cardiovascular risk factors were investigated in 297 patients (173 males, 124 females, mean age: 60 11 years) with chronic phase (3 months after onset) ischemic cerebrovascular diseases, and in 68 healthy volunteers (30 males, 38 females, mean age: 36 6 years). RESULTS: All investigated hemorheological factors were significantly (p < 0.05-0.0001) elevated in cerebrovascular patients compared to normal controls, the rise in Hct, WBV and PV are some of the most prominent findings. In the group of hypertensive, hyperlipidemic patients, smokers and alcoholics Hct, PFC, WBV, PV and AI were significantly (p < 0.05-0.0001) higher compared to healthy controls, the same factors except plasma fibrinogen concentration showed association with diabetic history. Comparing cerebrovascular patients with or without risk factors, the most severe hemorheological deficit was observed in patients with hyperlipidemia and smoking habits. CONCLUSIONS: In this study the authors proved in chronic ischemic cerebrovascular patients that hemorheological abnormalities persist in most cases for a long time after an acute stroke, significant correlation could be seen between blood rheology and cardiovascular risk factors. Examination of rheological parameters can support to choose the optimal medical treatment in the secondary prevention of stroke, correction of hemorheological disturbances can reduce the risk of recurrent stroke.