Prioritization of implementation barriers related to integrated care models in Central and Eastern European countries.

The importance of integrated care will increase in future health systems due to aging populations and patients with chronic multimorbidity, however, such complex healthcare interventions are often developed and implemented in higher income countries. For Central and Eastern European (CEE) countries it is important to investigate which integrated care models are transferable to their setting and facilitate the implementation of relevant models by identifying barriers to their implementation. This study investigates the relative importance of integrated care models and the most critical barriers for their implementation in CEE countries. Experts from Croatia, Hungary, Poland, Romania and Serbia were invited to complete an online survey within the SELFIE H2020 project. 81 respondents completed the survey. Although experts indicated that some integrated care models were already being implemented in CEE countries, the survey revealed a great need for further improvement in the integration of care, especially the managed care of oncology patients, coordinated palliative care of terminally ill patients, and nursing care of elderly with multimorbidity. Lack of long-term financial sustainability as well as of dedicated financing schemes were seen the most critical implementation barriers, followed by the lack of integration between health and social care providers and insufficient availability of human resources. These insights can guide future policy making on integrated care in CEE countries.

Implementation of evidence-based health policy in the field of integrated care: A Ritka Betegségek Nemzeti Eroforrás Központjának tervezési folyamata / Bizonyítékokon alapuló egészségpolitikai döntéshozatal az integrált ellátásban: A Ritka Betegségek Nemzeti Eroforrás Központjának tervezési folyamata

Összefoglaló. Bevezetés: A ritka betegséggel élok ellátásában fontos elorelépések történtek az elmúlt években. Egy következo lépés lehetne hazánkban a Ritka Betegségek Nemzeti Eroforrás (Uni-Versum) Központjának (a továbbiakban: Központ) létrehozása, amely az egészségügyi, szociális és köznevelési szolgáltatásokat összehangolva és kiegészítve személyközpontú ellátást nyújtana a betegek és támogatóik részére. Célkituzés: Célunk az volt, hogy egy nemzetközi tudományos módszertan alapján javaslatokat tegyünk arra, hogy milyen eszközökkel lehet feloldani a Központ megvalósításának lehetséges korlátozó tényezoit. Módszer: A Központ megvalósíthatóságának értékelésére interdiszciplináris szakmai egyeztetést szerveztünk különbözo érintett érdekcsoportok részvételével, a SELFIE H2020 kutatási projekt által kidolgozott módszertan alapján. Az elozetesen rangsorolt legfontosabb korlátozó tényezokre lehetséges megoldási javaslatokat tettünk. Eredmények: A lehetséges korlátozó tényezoket a résztvevok relevánsnak tartották a Központ létrehozásával kapcsolatban, és ezekre összesen 17 olyan konkrét javaslat született, amelyben a résztvevok között egyetértés alakult ki. A javaslatok kiterjedtek az ellátás tartalmára, az alkalmazott technológiák támogató szerepére, a humáneroforrás-korlátok megoldására, a hatékony vezetés és szervezés kialakítására, az összetett finanszírozási struktúra kialakítására és a kutatási lehetoségek megteremtésére is. Megbeszélés: A Központ megvalósítása esetén a ritka betegséggel élok ellátása az egészségügyi, szociális és köznevelési tevékenységeket integráló megközelítés felé mozdulna el. A kutatás során megfogalmazott javaslatok hozzájárulhatnak a Központ létrehozásához, amennyiben megvan az ehhez szükséges szakpolitikai támogatás is. Ezen túlmutatóan, a leírt munkamódszer más integrált ellátási modellek bevezethetoségének elemzéséhez is mintaként szolgálhat. Következtetés: Összefoglalva megállapíthatjuk, hogy a Központ létrehozásához számos, elozetesen is látható korlátozó tényezot kell feloldani. Az érdekcsoportok közös javaslatai alapján kialakítható egy olyan muködési forma, amely az ellátórendszerek kiegészítésével és összehangolásával jelentos társadalmi értéktöbbletet eredményezhet. Orv Hetil. 2021; 162(45): 1818-1825. INTRODUCTION: In Hungary, significant achievements have been made in the care of patients with rare diseases in recent years. A next step could be the establishment of the National Resource Centre for Rare Diseases (hereinafter: Centre) to facilitate patient-centered complex care by the integration and supplementation of existing health, social and educational services. OBJECTIVE: This research aimed to develop recommendations based on international scientific methodology to overcome potential implementation barriers of the aforementioned Centre. METHOD: To evaluate the feasibility of the implementation, we organized an interdisciplinary workshop with representatives of different stakeholder groups, adopting the methodology developed in the SELFIE H2020 research project. During the workshop, we discussed the previously ranked, most significant implementation barriers and made recommendations for potential solutions. RESULTS: The potential implementation barriers were considered relevant by the participants and, reflecting on these barriers, altogether 17 recommendations were developed by consensus. These recommendations were related to the content of service delivery, use of supportive technologies, overcoming workforce issues, establishing effective leadership, implementing a complex financing structure and creating research opportunities. DISCUSSION: Implementation of the Centre would shift the care of rare diseases towards personalized and integrated health, social and educational services. Our recommendations will contribute to the establishment of the Centre, subject to positive policy decision. Furthermore, our methodological approach could support the feasibility assessment of future integrated care solutions and programs. CONCLUSION: Several predictable barriers must be overcome to establish the Centre. Recommendations developed by representatives of relevant stakeholders could support successful implementation and societal value generation. Orv Hetil. 2021; 162(45): 1818-1825.

[The actual questions of the care of rare diseases]. / A ritka betegségek ellátásának aktuális kérdései.

The aim was to present the actual situation of rare diseases, especially to characterize the circumstances in Hungary. The most important developments were summarized which could help the care of rare disease patients in the everyday practice. There are around 800 000 patients with rare diseases in Hungary. The lack of information leads to "invisibility" for the health and social care system (most of them without ICD code). Therefore, these patients still have a huge disadvantage even when compared to the patients of common diseases. Important national and international measures took place in the last years to decrease these disadvantages. The Hungarian Centres of Expertise were officially approved, thus several health care providers were able to get membership in the forming European Reference Networks. The rare disease specific "Lifebelt" Information Centre and Help Line was established by HUFERDIS. These steps assist the implementation of the National Rare Disease Plan, although its formal approval process has temporarily stopped because of the reorganization of the health care system. The summarized developments can contribute to define better patient directions, and thus decrease the family knocks about the maze of health, social and educational systems. The realization of Rare Disease National Strategy is needed to improve the current fragmentation of services and enable patients and health, social and educational professionals to provide and use best practice care. This will ensure that all patients with rare disease cannot only be diagnosed quickly, but also have timely access to the care and support that they need, resulting in a decreasing burden of families and society. Orv Hetil. 2017; 158(47): 1851-1856.

[DISEASE BURDEN OP DUCHENNE MUSCULAR DYSTROPHY PATIENTS AND THEIR CAREGIVERS]. / DUCHENNE-FÉLE IZOMDISZTRÓFIÁVAL ÉLO BETEGEK ÉS GONDOZÓIK BETEGSÉGTERHEI.

BACKGROUND AND PURPOSE: Data on the disease burden of Duchenne Muscular Dystrophy are scarce in Hungary. The aim of this study was to assess patients' and their caregivers' health related quality of life and healthcare utilisations. METHODS: A cross sectional survey was performed as part of the European BURQOL-RD project. The EQ-5D-5L and Barthel Index questionnaires were applied, health care utilisations and patients' informal carers were surveyed. RESULTS: One symptomatic female carer, 50 children (boys 94%) and six adult patients (five males) participated in the study, the latter two subgroups were included in the analysis. The average age was 9.7 (SD = 4.6) and 24.3 (SD = 9.8) years, respectively. Median age at time of diagnosis was three years. The average EQ-5D score among children and adults was 0.198 (SD = 0.417) and 0.244 (SD = 0.322), respectively, the Barthel Index was 57.6 (SD = 29.9) and 53.0 (SD = 36.5). Score of satisfaction with healthcare (10-point Likert-scale) was mean 5.3 (SD = 2.1) and 5.3 (SD = 2.9). 15 children were hospitalised in the past 12 months for mean 12.9 (SD = 24.5) days. Two patients received help from professional carer. 25 children (mean age 11.1, SD = 4.4 years) were helped/supervisied by principal informal carer (parent) for mean 90.1 (SD = 44.4) hours/week and further family members helped in 21 cases. Correlation between EQ-5D and Barthel Index was strong and significant (0.731; p < 0.01) as well as with informal care time (-0.770; p < 0.01), but correlation with satisfaction with health care was not significant (EQ-5D: 0.241; Barthel Index: 0.219; informal care: -0.142). CONCLUSION: Duchenne muscular dystrophy leads to a significant deterioration in the quality of life of patients. Parents play outstanding role in the care of affected children. This study is the first in the Central and Eastern European region that provides quality of life data in this rare disease for further health economic studies.

Social/economic costs and health-related quality of life of mucopolysaccharidosis patients and their caregivers in Europe.

OBJECTIVES: To assess the health-related quality of life (HRQOL) of patients with mucopolysaccharidosis (MPS) and their caregivers and to quantify the disease-related costs from a societal perspective. METHODS: In the context of a multi-country study of rare diseases (BURQOL-RD project), a cross-sectional survey was performed among MPS patients in seven European countries. Data on demographic characteristics, health resource utilization, informal care, and loss of labor productivity were collected. The EQ-5D, Barthel index (BI), and Zarit burden interview (ZBI) questionnaires were used to assess patients' and their informal caregivers' quality of life, patients' functional ability, and caregivers' burden, respectively. RESULTS: Altogether, 120 patients (children 62 %, females 40 %) and 66 caregivers completed the questionnaire. Patients' mean age was 16.5 years and median age at diagnosis was 3 years. Adult patients' average EQ-5D and EQ VAS scores varied across countries from 0.13 to 0.43 and 30.0 to 62.2, respectively, mean BI was 46.7, and ZBI was 32.7. Mean informal care time was 51.3 h/week. The mean total annual cost per patient (reference year 2012) was €24,520 in Hungary, €25,993 in France, €84,921 in Italy, €94,384 in Spain, and €209,420 in Germany. Costs are also shown to differ between children and adults. Direct costs accounted for most of the costs in all five countries (80, 100, 99, 98, and 93 %, respectively). CONCLUSIONS: MPS patients experience substantial loss of HRQOL and their families take a remarkable part in their care. Although utilization of health and social care resources varies significantly across countries, MPS incurs considerable societal costs in all the countries studied.

[Cystic fibrosis -- disease burden and health-related quality of life of patients and their caregivers: results of the European BURQOL-RD survey in Hungary]. / Cystás fibrosissal élo betegek és gondozóik életminosége és betegségterhei: a BURQOL-RD európai felmérés magyarországi eredményei.

INTRODUCTION: Data on disease burden of cystic fibrosis in Hungary are scarce. AIM: To assess quality of life and resource utilisations of patients with cystic fibrosis. METHOD: In a cross-sectional survey (BURQOL-RD project), the EQ-5D-5L questionnaire was applied and healthcare utilisations were retrospectively surveyed. RESULTS: 110 patients participated in the study (age-groups, year: 0-13, N = 48; 14-17, N = 12; ≥18, N = 50), median age at the diagnosis was 1 year. EQ-5D-5L score in age-groups 18-24 and 25-34 was significantly lower than in the general population (p<0.05). 75 patients (68%) attended pulmonology care, 55 patients (50%) were hospitalised in the past 6 and 12 months, respectively, and 57 patients (52%) were taking dornase alpha. Five adult patients (10%) received help from non-professional caregiver. CONCLUSIONS: Cystic fibrosis leads to significant deterioration of quality of life. This study is the first from the Central Eastern European region that provides basic inputs for further health economic evaluations of cystic fibrosis care.

[Rare diseases and their patient organization: the Hungarian Federation of People with Rare and Congenital Diseases]. / A ritka betegségek és hazai betegszervezetük: a Ritka és Veleszületett Rendellenességgel Élok Országos Szövetsége.

The aim of the author is to discuss special issues of rare diseases, with emphasis on circumstances present in Hungary, including those leading to the foundation of the non-governmental organization, the Hungarian Federation of People with Rare and Congenital Diseases. The author briefly reviews the most important findings of current international surveys which have been performed with or without the involvement of member associations of the Hungarian Federation of People with Rare and Congenital Diseases. At the level of medical and social services in Hungary, it is still "incidental" to get to the appropriate expert or centre providing the diagnosis or treatment. It is difficult to find the still very few existing services due to the lack of suitable "pathways" and referrals. There are long delays in obtaining the first appointment, resulting in vulnerability and inequality along the regions. The overall consequence is the insufficiency or lack of access to medical and social services. There are also difficulties related to the supply of orphan medication and the long duration of hospitalization. At the level of patient organizations financial scarcity and uncertainty are typical, combined with inappropriate infrastructural background and human resources. The poor quality of organization of patient bodies along with insufficient cooperation among them are characteristic as well. The author concludes that a National Plan or Strategy is needed to improve the current fragmentation of services which would enable patients and health, social and educational professionals to provide and use the best care in the practice. This would ensure all patients with rare diseases to be diagnosed within a possible shortest time allowing access to the care and support needed in time resulting in a decrease in burden of families and society.

[Personalized medicine from the viewpoint of patients and their relatives]. / A személyre szabott orvoslás a betegek és hozzátartozóik szemével.

Our goal was to overview the situation of personalized medicine, especially to characterize the role of patient organizations. We embedded this process into the on-going procedures of the transformation of health care system, outlining the Hungarian and international tendencies. We introduce the exceptional role of rare diseases, among others the rare cancers, thanks to their special status. Some results of the recent Hungarian and international surveys are also demonstrated. The presented global tendencies give the frame for the necessary alteration of the Hungarian health care system. Beside the solution of the country-specific problems of our health care system, the main principles of the new paradigm of 21st century medicine are also influencing: personalized, participatory, preventive, predictive and proactive. The new medicine is continuously associated with the patients, instead of separated interventions. The changing of attitude is necessary for spreading these principles and also gives the basis of future medical service of society. The role of patient organizations is vital during this progress. The development is possible to the direction of patient-centred health care model by changing the structure of residential expenditure, even during the time of global financial crisis. However, a stronger community involvement is required. Good examples of this patient organization involvement are presented in the case of rare diseases, which can be, together with orphan drugs, the precursors to personalized medicine, paving the path to this direction. A closer participation of patients and their organizations is essential to transform the present health care system to the route of personalized medicine and to alter the public outlook.

[Diagnostic delay of rare diseases in Europe and in Hungary]. / A ritka betegségek diagnosztikájának késedelme Európában és Magyarországon.

UNLABELLED: The long diagnostic delay is a characteristic problem of rare disease patients. AIMS: Diagnostic delay was studied in 14 countries by EurordisCare2 involving patient organizations. METHODS: 252 Hungarian patients (cystic fibrosis; Duchenne muscular dystrophy; tuberous sclerosis, retinitis pigmentosa, and Williams' syndrome) completed the questionnaires. RESULTS: The median delay was longer in Hungary than in Europe (cystic fibrosis: 227 vs. 45 days; Duchenne muscular dystrophy: 467 vs. 360 days; tuberous sclerosis: 155 vs. 120 days). Patients' experience was similar in Hungary and in Europe. The proportion of misdiagnosis was 30.8% in Hungary (Europe: 41%), 34.8% of patients got diagnosis outside of living place region (EU: 26%) and 19.9% of them found the personal expenses too high (EU: 10%). Delivery of the diagnosis was unnecessary according to 27.4% of Hungarian patients (EU: 35%). CONCLUSIONS: The qualitative survey demonstrated that the problems with the diagnosis of rare diseases are widespread, the identified areas require interventions, and it confirmed the importance of centralized care.

Differential inhibition of single and cluster type tumor cell migration.

For the control of tumor metastasis it is important to identify chemical compounds with antimigratory potency. Agents acting against single cell and cluster type migration are necessary for successful antimetastatic therapy. In the present study, the migration of HT-1080 fibrosarcoma cells and OSCORT osteosarcoma cells was compared in a Boyden chamber and in an extracellular matrix (ECM)-based three-dimensional cell culture (3-DCC) model system. The Boyden chamber offers a model of single tumor cell migration, whereas the 3-DCC model system demonstrates invasive growth in the form of a cluster. Since PD98059 (MEK inhibitor) exclusively reduced migration in the 3-DCC model, it may be plausible that the ERK/MAPK signaling pathway is essential for cluster type migration. Interestingly, single cell migration was stimulated upon blocking phosphatidylinositol 3-kinase (PI3K) and also p38-MAPK by treatment with LY294002 and SB203580 respectively. A remarkable reduction of single cell migration was observed following treatment with okadaic acid, a phosphatase 1 (PP1) and 2A (PP2A) inhibitor, which was rather intriguing. This study provided evidence that certain cytotoxic/cytostatic agents at appropriate concentrations were able to preferentially inhibit certain types of migration relative to cell proliferation. Single cell migration was selectively inhibited by taxol at very low subtoxic concentration, whereas 5-hexyl-2'-deoxyuridine (HUdR) exclusively inhibited the cluster type of migration. The borrelidin compound was able to inhibit both types of tumor cell migration, but single tumor cell migration was much less affected. It is interesting that migration was more reduced than proliferation by borrelidin, especially at the advanced growth stage. Taxol is recommended as an agent acting against single cell migration, as well as HUdR and borrelidin as leading compounds for developing antimetastatic drugs against cluster type migration.

[Study of drugs against neoplastic metastasis]. / A tumorok áttétképzését korlátozó hatóanyagok kutatása.

Further progress in the therapy of malignant diseases is expected from the introduction of potent antimetastatic drugs. Surveying of the complex and multi-step behavior of the metastatic process, compounds showing inhibitory action against tumor cell migration may be ranked among the promising antimetastatic agents. Our present study indicate, however, that the antimigratory actions of certain antitumor drugs (doxorubicin, taxol), and inhibitors of signal transduction (PD-98059, LY-294002, SB-203580) are highly dependent on the assay applied (Boyden-chamber, 3D ECM cell culture). It has been proposed that agents interrupting cell-extracellular matrix contacts (hexyldeoxyuridine, borrelidin) and others interfering with the regulatory mechanism of gene translation (rapamycin, ribavirin) could be regarded as leading compounds in the antimetastatic drug development process. Nevertheless, for introducing diagnostically based targeted therapy the forthcoming tasks must include the further elucidation of the molecular mechanisms implicated in the amoeboid and cluster type of cell migration.

Repopulation of osteosarcoma cells after treatment with doxorubicin in the presence of extracellular matrix biopolymers.

PURPOSE: To elucidate the role of extracellular matrix (ECM) in repopulation capacity of osteosarcoma cells after doxorubicin treatment. METHODS: OSCORT cells established in our laboratory from a human osteosarcoma, were treated with doxorubicin in monolayer for 4 h, then cells were further incubated either in monolayer or in ECM-containing three-dimensional cell-culture (3-DCC), apoptosis induction and changes in cell number were measured. Alkaline comet assay was applied to estimate DNA damage, immunoblot technique and immunocytochemistry were used to investigate p53 protein synthesis, and the repopulating capacity in monolayer culture and in ECM-based 3-DCC, after doxorubicin treatment was measured. In addition to OSCORT culture five other human cell lines (HT-1080, PC-3, MDA-MB231, A-431 and ZR-75-1) were used to compare the antimigratory and antiproliferative effects of doxorubicin. RESULTS: The apoptotic index, the extent of DNA damage and the representation of p53 were much lower in the OSCORT cell cultures if the cells were exposed to ECM after treatment with doxorubicin. The doxorubicin-treated OSCORT cells transferred from the monolayer culture were not able to proliferate at all, at the same time, the cytoprotection provided by ECM prevailed upon transferring the cells into plastic dish, and resulted in potent repopulation capacity of the cells. CONCLUSIONS: Present data indicate that ECM contributes to failure in therapy of human osteosarcoma in clinical situation. Overall, the application of ECM-based 3-DCC could be suggested as an appropriate model system for the better understanding of antitumor drug action and hereby to set the stage for promising novel pharmacological approaches in cancer therapy.

Invasive growth and topoisomerase-switch induced by tumorous extracellular matrix in osteosarcoma cell culture.

Osteosarcoma cells are capable of extracellular matrix (ECM) synthesis. The ability of ECM to trigger the proliferation of a novel osteosarcoma cell line (OSCORT) was tested in this study in relation to a known tumor ECM, isolated from Engelbreth-Holm-Swarm (EHS) sarcoma (EHS-ECM). OSCORT was grown in monolayer, in EHS-ECM and in ECM deposited by the cells (OSCORT-ECM). Both EHS-ECM and OSCORT-ECM increased the proliferation and migration of OSCORT cells. Among the ECM biopolymers, heparan sulfate proteoglycan (HSPG) and fibronectin enhanced invasive growth, collagen type IV reduced it, while laminin had no effect. Among the ECM components HSPG and collagen IV increased both the synthesis and activation of collagenase type IV, and all the ECM components substantially increased beta1 integrin levels in the cells. The majority of ECM biopolymers decreased the level of topoisomerase I (except laminin) and elevated topoisomerase II (except fibronectin) in OSCORT. The switch in the ratio between the activities of topoisomerases I and II was mainly due to HSPG. The HSPG synthesized by OSCORT cells is described as agrin, which is a novel finding. The present study showed that HSPG (agrin) showed the most remarkable stimulatory action on the growth and migration of OSCORT cells. HSPG-induced topoisomerase II-induction deserves further experimentation, to discover its relevance to tumor progression.

Antiproliferative and antimigratory effects of doxorubicin in human osteosarcoma cells exposed to extracellular matrix.

Osteosarcoma cells are involved in the remodeling of the extracellular matrix (ECM) that affects their growth, invasive and metastatic activities. The tumour ECM provided effective protection against chemotherapy agents in several previously studied malignancies. The current study examined the effects of doxorubicin on cells that were migrated into a 3-dimensional extracellular matrix gel (ECM-gel) in comparison with its effects on cells remaining in the monolayer compartment. A human osteosarcoma cell line (OSCORT) was treated with doxorubicin in monolayer culture for 4 or 24 hours, and then overlaid by ECM-gel for 24 hours. Tumour cells remaining in the monolayer were separated from the cells migrated into ECM-gel, and both of them were characterized. OSCORT cells migrated into ECM-gel showed elevated levels and activity of topoisomerase II, increased protein expression of beta1 integrin and matrix metalloproteinase-9 activity. Doxorubicin treatment for 4 hours resulted in increased cytotoxicity in the monolayer compartment relative to the cells migrated into ECM-gel, whereas 24-hour treatment at a low concentration (0.01 microg/ml) showed an antimigratory effect. Different antiproliferative and antimigratory effects of doxorubicin treatment schedules warrant short-term, high-dose treatment for targeting the tumour growth, and long-term, low-dose treatment for targeting the invasion of osteosarcoma.

Selective suppression of an endothelin and platelet-derived growth factor containing vesicular system in endothelium of rat saphenous vein by long-term orthostasis.

Electron-dense vesicles were observed in rat vascular endothelium. The purpose of this study was to characterize their content(s), venous-arterial distribution and response to chronic orthostatic stress in extremity vessels. Saphenous and brachial vessels - saphenous vein (SV), saphenous artery (SA), brachial vein, brachial artery - were prepared for electron microscopy to quantitate the vesicle area within the endothelium following immunohistochemical and immunocytochemical identification. The effect of long-term orthostasis was assessed by exposure to head-up tilt for 2 weeks. The vesicular area in relation to the total cross-sectional area of the endothelial cells in the SV and SA of normal and confined control groups was 3.88 +/- 0.38 versus 0.89 +/- 0.06% (p < 0.05) and 4.92 +/- 0.25 versus 1.09 +/- 0.47% (p < 0.05), respectively. Head-up tilt suppressed the vesicle content of the SV to 2.26 +/- 0.39% (p < 0.05), but it remained low in the SA (1.29 +/- 0.45%), brachial vein (0.45 +/- 0.12%) and brachial artery (0.59 +/- 0.17%). Endothelin and platelet-derived growth factor, but not acidic phosphatase activity or lipid content, could be identified in the vesicles. Plasma endothelin levels were unchanged. We conclude that dense vesicles in the endothelium of extremity vessels are not cell degradation products. They may represent a vesicular secretory or storage system for endothelin and platelet-derived growth factor which participates in regional vascular adaptation to long-term orthostatic load.

Vacuole formation in the endothelium of rat extremity vessels depends on fixation techniques and vessel type.

Applying immersion fixation for electron microscopy, huge clear endothelial membrane-bound vacuoles of 0.1-3 microm diameter were noted in the extremity veins of Sprague-Dawley rats. Histological and electron microscopic histochemical methods were applied to determine whether they were the product of programmed cell death or any other kind of cell damage. Image analyzer was used to measure the total area of the vacuoles in the endothelium cells. Neither lipid content nor acidic phosphatase activity could be identified in the vacuoles. In saphenous and brachial veins, the vacuoles occupied 20.6 +/- 2.21% and 18 +/- 2.45% of the endothelium, respectively. Venous endothelium of two different strains of rat also contained the vacuoles. No such structures appeared in extremity arteries. Long-term tilting did not influence vacuolization. Using in vivo whole body fixation, only pinocytotic and dense microvesicles, but no vacuoles were noted. In conclusion, the clear vacuolar structures represent neither lipid inclusions nor secondary lysosomes. The method of tissue fixation is critical when venous endothelial vesicles are investigated. It is presumed that the vacuoles originated from intra- or intercellular microstructures, and that in case of the collapsible vein segments, their size is increased under the pathological-hypoxic and low-pressure-conditions of in vitro fixation.