Diagnosis and treatment of pelvic congestion syndrome: Single-centre experiences.

BACKGROUND: One of the underestimated causes of chronic pelvic pain (CPP) in women may be pelvic congestion syndrome (PCS) that is defined as the presence of varicose of ovarian and pelvic veins associated with chronic pain in the region of the pelvis. This pain is present longer than 6 months and intensifies with prolonged standing, coitus and menstruation. The disease constitutes a diagnostic as well as therapeutic problem, thus posing a challenge for the clinician. Transcatheter ovarian vein embolization might be a safe and effective option for PCS treatment. OBJECTIVES: The objective of this study was to evaluate the efficacy of ovarian vein embolization ovarian as a method of the PCS treatment. MATERIAL AND METHODS: Between 2002-2012, 11 embolization procedures were performed in 10 women (age range: 34-43; median age 39) with the diagnosis of PCS. One patient underwent embolization procedure twice. In 1 case the combined therapy of endovascular embolization and surgical phlebectomy of vulvar varices was performed. RESULTS: There were no major intrainterventional complications. In all the patients (100%) a significant improvement in the clinical status was noted. The procedure improved the quality of life in the patients. Three women (30%) had a mild recurrence of the symptoms at mid-term follow-up. Among 8 women who had complained of dyspareunia prior to embolization 6 patients reported complete pain relief, in other 2 cases the pain subsided partially. There was a significant decrease in the severity of symptoms associated with hemorrhoids. CONCLUSIONS: We consider embolization of insufficient ovarian veins an effective and safe way of treatment in a well-selected group of patients with PCS.

The Formation of Blood Vessel After the Administration of the Plasmid Encoding Ang-1 Gene in Fischer Rats.

BACKGROUND: Chronic limb ischemia is a serious clinical problem. Patients who do not qualify for standard treatment may benefit from novel gene therapies. OBJECTIVES: This study evaluated angiogenesis following intramuscular injections of angiogenic plasmid Ang-1 in Fisher rats. MATERIAL AND METHODS: Twenty rats had plasmids injected intramuscularly in their hind limbs. The study group consisted of 10 animals which received the Ang-1 plasmid, while the control group consisted of 10 rats that received an empty plasmid. All the animals were euthanized after 12 weeks and tissue samples from the hind limb thigh muscles and internal organs were harvested for histological and immunohistochemical examinations. To assess the angiogenesis the number of vessels in the hind limb muscles visualized by the SMA and FVIII markers was counted for each animal in five separate microscopic fields. RESULTS: There were no pathological lesions or any signs of neoplastic angiogenesis in any of the 20 rats. The number of vessels visualized by the FVIII marker in the study group was two times higher than in the control group (median: 12, range: 7-25 vs. median: 6, range: 2-15; p < 0.0001). The median estimated that the number of vessels visualized by the SMA marker is 63% higher in the study group compared to the control group (median: 6.5, range: 1-12 vs. median: 4, range: 0-10; p = 0.0008). CONCLUSIONS: Intramuscular injections of Ang-1 plasmids induced angiogenesis in the rat hind limb muscles.

Surgical management of extracranial carotid artery aneurysms.

BACKGROUND: We present the methods and results of the surgical management of extracranial carotid artery aneurysms (ECCA). Postoperative complications including early and late neurological events were analysed. Correlation between reconstruction techniques and morphology of ECCA was assessed in this retrospective study. PATIENTS AND METHODS: In total, 32 reconstructions of ECCA were performed in 31 symptomatic patients with a mean age of 59.2 (range 33-84) years. The causes of ECCA were divided among atherosclerosis (n = 25; 78.1%), previous carotid endarterectomy with Dacron patch (n = 4; 12.5%), iatrogenic injury (n = 2; 6.3%) and infection (n = 1; 3.1%). In 23 cases, intervention consisted of carotid bypass. Aneurysmectomy with end-to-end suture was performed in 4 cases. Aneurysmal resection with patching was done in 2 cases and aneurysmorrhaphy without patching in another 2 cases. In 1 case, ligature of the internal carotid artery (ICA) was required. RESULTS: Technical success defined as the preservation of ICA patency was achieved in 31 cases (96.9%). There was one perioperative death due to major stroke (3.1%). Two cases of minor stroke occurred in the 30-day observation period (6.3%). Three patients had a transient hypoglossal nerve palsy that subsided spontaneously (9.4%). At a mean long-term follow-up of 68 months, there were no major or minor ipsilateral strokes or surgery-related deaths reported. In all 30 surviving patients (96.9%), long-term clinical outcomes were free from ipsilateral neurological symptoms. CONCLUSIONS: Open surgery is a relatively safe method in the therapy of ECCA. Surgical repair of ECCAs can be associated with an acceptable major stroke rate and moderate minor stroke rate. Complication-free long-term outcomes can be achieved in as many as 96.9 % of patients. Aneurysmectomy with end-to-end anastomosis or bypass surgery can be implemented during open repair of ECCA.

Type of Renal Replacement Therapy (Hemodialysis versus Peritoneal Dialysis) Does Not Affect Cytokine Gene Expression or Clinical Parameters of Renal Transplant Candidates.

UNLABELLED: Patients with renal failure suffer from immune disturbances, caused by uremic toxins and influenced by dialysis treatment. The aim of the present study was to reveal whether type of dialysis modality (hemodialysis, HD, versus peritoneal dialysis, PD) differentially affects the immunocompetence, particularly the expression of genes involved in the immune response. MATERIAL: 87 renal transplant candidates (66 HD, 21 PD) were included in the study. METHODS: The peripheral blood RNA samples were obtained with the PAXgene Blood system just before transplantation. The gene expression of CASP3, FAS, TP53, FOXP3, IFNG, IL2, IL6, IL8, IL10, IL17, IL18, LCN2, TGFB1, and TNF was assessed with real-time PCR on custom-designed low density arrays (TaqMan). Gene expression data were analyzed in relation to pretransplant clinical parameters. RESULTS: The mean expression of examined genes showed no significant differences between PD and HD with the exception of FAS, expression of which was 30% higher in PD patients compared to the HD group. There was nonsignificantly higher expression of proinflammatory cytokines in the PD group. The clinical inflammatory parameters (CRP, albumin, cholesterol, and hemoglobin levels) did not differ between the groups. CONCLUSION: Type of renal replacement therapy exerts no differential effect on cytokine gene expression or inflammatory clinical parameters.

Combined autologous bone marrow mononuclear cell and gene therapy as the last resort for patients with critical limb ischemia.

INTRODUCTION: Our study was designed to investigate the safety and efficacy of combined autologous bone marrow mononuclear cell (MNC) and gene therapy in comparison to conventional drug therapy in patients with critical limb ischemia (CLI). MATERIAL AND METHODS: Thirty-two patients with CLI persisting for 12-48 months (average time 27.5 months) were randomized into 2 groups, each group consisting of 16 patients. In the first group, administration of autologous bone marrow MNC and vascular endothelial growth factor (VEGF) plasmid was performed. The patients from the second group were treated pharmacologically with pentoxifylline. Ankle-brachial index (ABI) was measured and angiography was performed before and finally 3 months after treatment. The pain was evaluated using the Visual Analog Scale (VAS) before and after 3 months. RESULTS: Ankle-brachial index improved significantly from 0.29 ±0.21 to 0.52 ±0.23 (p < 0.001) in 12 patients (75.0%) 3 months after the experimental therapy in group 1. In this group angiography showed the development of collateral vessels. Ischemic ulcers healed completely in 11 patients (68.75%). In group 2 the ABI did not improve in any patient; moreover the complete healing of skin ulcers was not found in any of the patients of this group. Amputation was performed in 4 (25.0%) patients in group 1, and in 8 patients (50%) from group 2. CONCLUSIONS: These data after 3-month follow-up indicate that intramuscular injection of MNC combined with gene therapy in patients with chronic CLI is safe, and a more feasible and effective method of treatment than the conventional therapy. However, both therapies are limited by the degree of microcirculation damage.

Serum and urine metabolomic fingerprinting in diagnostics of inflammatory bowel diseases.

AIM: To evaluate the utility of serum and urine metabolomic analysis in diagnosing and monitoring of inflammatory bowel diseases (IBD). METHODS: Serum and urine samples were collected from 24 patients with ulcerative colitis (UC), 19 patients with the Crohn's disease (CD) and 17 healthy controls. The activity of UC was assessed with the Simple Clinical Colitis Activity Index, while the activity of CD was determined using the Harvey-Bradshaw Index. The analysis of serum and urine samples was performed using proton nuclear magnetic resonance (NMR) spectroscopy. All spectra were exported to Matlab for preprocessing which resulted in two data matrixes for serum and urine. Prior to the chemometric analysis, both data sets were unit variance scaled. The differences in metabolite fingerprints were assessed using partial least-squares-discriminant analysis (PLS-DA). Receiver operating characteristic curves and area under curves were used to evaluate the quality and prediction performance of the obtained PLS-DA models. Metabolites responsible for separation in models were tested using STATISTICA 10 with the Mann-Whitney-Wilcoxon test and the Student's t test (α = 0.05). RESULTS: The comparison between the group of patients with active IBD and the group with IBD in remission provided good PLS-DA models (P value 0.002 for serum and 0.003 for urine). The metabolites that allowed to distinguish these groups were: N-acetylated compounds and phenylalanine (up-regulated in serum), low-density lipoproteins and very low-density lipoproteins (decreased in serum) as well as glycine (increased in urine) and acetoacetate (decreased in urine). The significant differences in metabolomic profiles were also found between the group of patients with active IBD and healthy control subjects providing the PLS-DA models with a very good separation (P value < 0.001 for serum and 0.003 for urine). The metabolites that were found to be the strongest biomarkers included in this case: leucine, isoleucine, 3-hydroxybutyric acid, N-acetylated compounds, acetoacetate, glycine, phenylalanine and lactate (increased in serum), creatine, dimethyl sulfone, histidine, choline and its derivatives (decreased in serum), as well as citrate, hippurate, trigonelline, taurine, succinate and 2-hydroxyisobutyrate (decreased in urine). No clear separation in PLS-DA models was found between CD and UC patients based on the analysis of serum and urine samples, although one metabolite (formate) in univariate statistical analysis was significantly lower in serum of patients with active CD, and two metabolites (alanine and N-acetylated compounds) were significantly higher in serum of patients with CD when comparing jointly patients in the remission and active phase of the diseases. Contrary to the results obtained from the serum samples, the analysis of urine samples allowed to distinguish patients with IBD in remission from healthy control subjects. The metabolites of importance included in this case up-regulated acetoacetate and down-regulated citrate, hippurate, taurine, succinate, glycine, alanine and formate. CONCLUSION: NMR-based metabolomic fingerprinting of serum and urine has the potential to be a useful tool in distinguishing patients with active IBD from those in remission.

[Stem and progenitor cells in biostructure of blood vessel walls]. / Komórki macierzyste i progenitorowe w biostrukturze scian naczyn krwionosnych.

Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, "anchored" in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC). Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as "subendothelial or vasculogenic zones". Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies.

Transplantation of autologous bone marrow mononuclear cells with VEGF gene improves diabetic critical limb ischaemia.

INTRODUCTION: The aim of this study was to assess the safety and efficacy of combined autologous bone marrow mononuclear cell and VEGF165 gene therapy in patients with diabetes mellitus suffering from critical limb ischaemia (CLI). MATERIAL AND METHODS: The administration of mononuclear cells (MNCs) and naked VEGF165 plasmid was performed in 16 limbs of 16 patients with rest pain and ischaemic ulcers due to diabetes. MNCs and plasmid were injected into the muscles of the ischaemic limbs. The levels of VEGF in serum and the ankle-brachial index (ABI) were measured before and after treatment. The Visual Analogue Scale (VAS) was used to evaluate pain sensation. CT angiography was performed before and after three months of therapy. RESULTS: Mean (± SD) plasma levels of VEGF increased non-significantly from 257 ± 80 pg/L to 391 ± 82 pg/L (p 〉 0.05) two weeks after therapy. The ABI improved significantly from 0.26 ± 0.22 to 0.49 ± 0.30 (p 〈 0.001) three months after therapy. A decrease in rest pain was observed in all patients; mean VAS decreased from 6.3 ± 1.4 to 1.2 ± 1.1 after three months (p 〈 0.002). Angiograms showed the development of collateral vessels in 12 limbs. Ischaemic ulcers healed in 12 limbs. Amputation was performed in four patients only, because of advanced wound infection. However, the level of amputations was lowered below knee level in these cases. Complications were limited to transient leg oedema in two patients and fever in two patients. CONCLUSIONS: Intramuscular bone marrow MNCs autotransplantation combined with the administration of phVEGF165 gene is safe, feasible and effective for patients with diabetes and CLI.

[Usage of hydrophilic catheters and guidewires in endovascular surgery]. / Zastosowanie prowadników i cewników hydrofilnych w chirurgii endowaskularnej.

AIM OF STUDY: The aim of this study was to evaluate the effectiveness of hydrophilic catheters and guidewires during endovascular overcoming long stenoses or occlusions of the superficial femoral and popliteal artery. MATERIAL AND METHODS: Based on 142 procedures rated the functionality of the equipment of the hydrophilic coating. The operations were performed in the years 2010-2012 in the Department of Vascular, General and Transplantation, Medical University in Wroclaw. Procedures related to recanalization or enlargement of the superficial femoral artery. Patients were divided into groups according to the Consensus TASC II depending on the length change. Each patient was assessed ankle-brachial ratio (ABI), claudication distance measured and constructed with double ultrasound imaging (USG-DD). In doubtful cases an additional study was performed with contrast computed tomography (angio-CT). The procedure was performed at the Laboratory of angiography using a angiograph Siemens Artis Zee Ceiling. Every time the contrlateral access was made, and as the first step the angiography was performed to verify type of changes in the arteries RESULTS: . A significant benefit of using hydrophilic guidewires and catheters in patients with long stenoses or occlusions. In case of long and calcified changes, hydrophilic catheters was the only option because it gave good support for hydrophilic guidewire. CONCLUSIONS: The changes in the type C and D according to the criteria for TASC II, an essential tool to achieve a positive treatment effect is the use of hydrophilic catheters and guidewires.

Evaluation of the humoral and cellular immune responses after implantation of a PTFE vascular prosthesis.

INTRODUCTION: The experiment was designed in order to determine the immunological processes that occur during the healing in synthetic vascular grafts, especially to establish the differences in the location of the complement system proteins between the proximal and distal anastomosis and the differences in the arrangement of inflammatory cells in those anastomoses. The understanding of those processes will provide a true basis for determining risk factors for complications after arterial repair procedures. MATERIAL/METHODS: The experiment was carried out on 16 dogs that underwent implantation of unilateral aorto-femoral bypass with expanded polytetrafluoroethylene (ePTFE). After 6 months all animals were euthanized to dissect the vascular grafts. Immunohistochemical assays and electron microscopic examinations were performed. RESULTS: Immunohistochemical findings in the structure of neointima between anastomoses of vascular prostheses demonstrated significant differences between humoral and cellular responses. The area of proximal anastomosis revealed the presence of fibroblasts, but no macrophages were detected. The histological structure of the proximal anastomosis indicates that inflammatory processes were ended during the prosthesis healing. The immunological response obtained in the distal anastomosis corresponded to the chronic inflammatory reaction with the presence of macrophages, myofibroblasts and deposits of complement C3. DISCUSSION: The identification of differences in the presence of macrophages and myofibroblasts and the presence of the C3 component between the anastomoses is the original achievement of the present study. In the available literature, no such significant differences have been shown so far in the humoral and cellular immune response caused by the presence of an artificial vessel in the arterial system.

[The treatment of dissected thoraco-abdominal aorta aneurysm with the use hybrid procedure]. / Zaopatrzenie tetniaka aorty piersiowo-brzusznej przy uzyciu procedur hybrydowych.

AIM OF STUDY: We analyzed the case of a patient treated in Vascular Surgery Department with the use of the hybrid procedure with a good results. MATERIALS AND METHODS: Acute cases of dissected aortic aneurysm are commonly known as an immediate danger of human live and determinate a big challenge for physicians. The collaboration of classic and endovascular methods (hybrid procedures) gives much more chances to improve patient's survival and resumption to normal life activity. Endovascular procedures are limiting the operation shock, improving recovery time. That means rising the chances of survival so advanced surgical procedure. CONCLUSION: Hybrid procedures are a modern technic that gives good results.

[The surgical treatment of thoracic outlet syndrome]. / Leczenie chirurgiczne zespolu uciskowego górnego otworu klatki piersiowej.

UNLABELLED: In this paper the surgical treatment of thoracic outlet syndrome (TOS) is presented. MATERIAL AND METHODS: The investigation of 74 patients treated for vascular complications of the TOS the Paget-Schroetter syndrome and postthrombotic syndrome (27 patients), as well as upper limb ischemia and/or the subclavian artery aneurysm (14 patients) and for neurological complications of the TOS (33 patients) was performed. In case of venous thrombosis the treatment consisted of thrombolytic therapy and decompressive procedures that included transaxillary first rib resection and other surgical procedures that excise different anomalies in the region of the thoracic outlet. In case of complications associated with compression of the subclavian artery the operation consisted of resection of the first rib and accessory osseous and muscular pathological elements using supraclavicular and/or infraclavicular approach with implantation of vascular bypass were performed. In the neurological syndrome of TOS the operation consisted of transaxillary first rib resection and other surgical procedures that excise different anomalies in the region of the thoracic outlet. The therapy results were estimated with use of the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire of the American Academy of Orthopedic Surgeons. RESULTS: In case of venous complications the thrombolytic therapy was successful in all cases the restoration of complete patency was obtained. In all patients first rib was resected via transaxillary approach. The DASH questionnaire revealed the full return of upper limb function in most of patients. Improvement was obtained the in the cases with postthrombotic syndrome. In case of upper limb ischemia the improvement of blood flow was obtained after the subclavian-brachial bypass implantation (5 patients). In this group the DASH score showed return to full activity. In case of subclavian artery aneurysm surgery (9 patients) the DASH scale revealed worsening of limb function in 4 patients during the follow-up period. In the neurological syndrome of TOS the restoration of complete activity of limb was observed. The DASH scale revealed worsening of limb function in 4 patients during the follow-up period. CONCLUSIONS: The optimal therapy of vascular complications is multimodal treatment (thrombolysis or reconstructive vascular procedure with decompressive surgery). The surgical treatment of neurological TOS halts degradation of brachial splice. The decompression of neurovascular bundle in vascular TOS should include the first rib resection in each case.

[Presence of Chlamydia pneumoniae in the carotid artery]. / Wystepowanie Chlamydia pneumoniae w tetnicach szyjnych.

UNLABELLED: There is growing experimental evidence that Chlamydia pneumoniae is a risk factor and contribute to the development of atherosclerosis of carotid artery. This process might cause stenosis of carotid artery and TIA or stroke. AIM: Aim of this study was to evaluate the frequency of Ch. pneumoniae infection in carotid artery stenosis patients and in control group-healthy artery from multiorgan donors. MATERIAL AND METHODS: From each of 84 patients undergoing carotid endarterectomy the samples were analyzed by nested PCR for Ch. pneumoniae DNA. Furthermore we determined DNA Ch. pneumoniae in carotid artery from 20 multiorgan donors. RESULTS: In control group-healthy artery the PCR for Ch. pneumoniae was negative in all samples. Ch. pneumoniae was detected in 57 patients (67.85%) with symptomatic carotid artery stenosis, however in 27 patients (32.15%) the PCR test was negative. CONCLUSIONS: We did not observe infection of Ch. pneumoniae in healthy carotid artery-control group. We noted great frequency of infection in patients with stenosis of carotid artery. Patients with stenosis of carotid artery can be candidates to antibiotic therapy, which can slow down the progression of artery stenosis.

[Incidence of factor VII and C3 in vascular anastomosis]. / Wystepowanie czynnika VII krzepniecia krwi oraz czynnika C3 ukladu dopelniacza w zespoleniach naczyniowych.

In order to study pathogenesis of vascular prosthesis healing process the following experiment was designed. 16 dogs underwent implantation of unilateral straight aorto-femoral teflon (PTFE, polytetrafluoroethylene) by-pass. After 6 months all dogs were killed, dissected and vascular prostheses with margin of adjacent aorta and femoral artery were collected for further study. Areas of proximal and distal anastomosis were examined immunohistochemically. Presence of coagulation factor VII, and C3 complement factor were studied. The obtained results were analyzed statistically by means of t-Student test. Factor VII as well C3 were found in areas of both proximal and distal anastomosis. Concentration of all two substances in proximal and distal anastomosis was compared. No statistically valid differences in factor VII concentration in proximal and distal anastomosis were found, whereas amounts of C3 factor as well as degree of extracellular matrix infiltration were markedly higher in distal anastomosis.

[Immunosuppression in the treatment of vascular prosthesis infection with arterial transplantation]. / Immunosupresja w leczeniu zakazen protez naczyniowych przeszczepami tetniczymi.

AIM: The purpose of this study is to evaluate the use of immunosuppression in treatment of prosthetic graft infections with arterial transplantation. MATERIAL AND METHODS: In this paper 29 cases of the massive aorto-ilio-femoral graft infection treated by the replacement of infected prosthesis with arterial homograft are presented. The arterial allograft was stored with application of cold ischemia method in preservation solution at 4 degrees C. During the follow up period the patients were divided into two groups: group received immunosuppressive regimen after surgery (n = 16) and group without immunosuppression (n = 13). The Duplex-Doppler ultrasound, the scintigraphy with use of Technetium-labeled leukocytes, bacteriological and antigenic examination and blood levels of Cyclosporin A were used in the diagnostic trial of infection and of the healing process of the homograft. In both groups there was performed evaluation of arterial wall by using the scanning electron microscopy. RESULTS: In the group with immunosuppression no complications due to the homograft's wall degradation and deficiency of cell mediated immunity in infections were noticed. In the group without immunosuppression there were observed complications related to the impairment of the allograft wall: in 3 cases--the graft rupture, in 2 cases--the graft true aneurysm and homograft thrombosis in 3 cases. CONCLUSION: The use of immunosuppression in transplantation of artery produces increase in survival rate and improves function of arterial graft.

The treatment of massive prosthetic grafts infections with the use of silver/collagen coated dacron vascular prosthesis.

In this paper the use of silver-coated medical prosthesis of massive aorto-bifemoral and ilio-femoral dacron graft infection with hemorrhage is presented. To solve this problem in situ replacement was attempted using silver-coated dacron vascular prosthesis more resistant to infection. 9 patients with this therapeutic method is reported. Although positive clinical effect was obtained, the scintigraphy and Duplex Doppler Ultrasound of implanted graft revealed its infection. In our opinion therefore application of silver-coated medical prosthesis should be very cautious and limited to the critical states.

Treatment of a rare case of local prosthetic graft infection with silver coated prosthesis.

The infection after synthetic vascular prosthetic graft implantation remains a serious complication of reconstructive vascular surgery. Surgical treatment consists of complete removal of the infected vascular graft with the preservation of the limb circulation. In this paper the case of aortofemoral by-pass infection limited to the distal part of the branches is presented. Because of the unsatisfactory results of conventional treatment the patients underwent the in situ replacement of infected prosthesis with the silver/collagen coated prosthesis. The postoperative check up (clinical examination, duplex-doppler ultrasound, scintigraphy of Technetium 99m-labeled leucocytes) revealed the complete remission of infection. The surgery can be limited to the replacement of infected segment of prosthesis with arterial homograft, but this therapeutic method requires further investigations and scrupulous observations.