Interleukin-1 alpha as a factor in occlusive vascular disease

Endotoxin-activated cultured neonatal rat cardiomyocytes express functional surface-associated interleukin-1α

Interleukin-1 (IL-1) is a potent regulator of cardiovascular proliferation, apoptosis, contraction or production of inflammatory mediators. Thus, we investigated expression and function of IL-1 in cultured neonatal rat heart cells upon endotoxin stimulation. We show that cultured neonatal rat cardiomyocytes expressed IL—1α and IL—1β mRNA. The cells expressed functional cell-associated IL—1 activity and a specific anti-IL—1α-antibody inhibited the activity. Biologically active IL—1α was present at the cell surface of the cardiomyocytes, as indicated in co-culture experiments. Immunohistochemistry showed IL—1α-staining of the neonatal cardiomyocytes. Although the cells also expressed IL—1β mRNA, we did not detect IL—1β in the supernatants of cultured cardiomyocytes by ELISA or in immunohistochemical staining. Furthermore, neonatal and adult rat heart tissues expressed IL—1α mRNA, whereas fetal, but not adult, human cardiac tissues expressed detectable IL—1α mRNA. In contrast, IL-1β mRNA was present in rat and human fetal and adult samples. Furthermore, in patients with dilated or ischemic cardiomyopathy, we measured IL—1β, but not IL—1α, mRNA. These results provide evidence for the presence of functionally active IL—1α on the cell surface of neonatal rat cardiomyocytes and may suggest a differential role of IL—1α in regulation of cellular functions during development, aging and disease in rat and human heart cells.

Immune-mediated and lipid-mediated platelet function in atherosclerosis

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is the leading cause of death and morbidity worldwide. Detailed knowledge of the mechanisms of atherosclerosis, the main underlying disease of CVD, will enable improved preventive and therapeutic options, thus potentially limiting the burden of vascular disease in aging societies. A large body of evidence illustrates the contribution of platelets to processes beyond their traditionally recognized role as mediators in thrombosis and hemostasis. Recent advances in molecular biology help to understand the complexity of atherosclerosis.

RECENT FINDINGS

This article outlines the role of platelets as modulators of immune responses in the context of atherosclerosis. It provides a short overview of interactions between platelets and endothelial cells or immune cells via direct cell contact or soluble factors during atherogenesis. By means of some well examined, exemplary pathways (e.g. CD40/CD40L dyad), this article will discuss recent discoveries in immune-related function of platelets. We also focus on the relationship between platelets and the lipid metabolism highlighting potential consequences to atherosclerosis and dyslipidemia.

SUMMARY

A better understanding of the molecular mechanisms of platelet-related immune activity allows their utilization as powerful diagnostic tools or targets of therapeutic intervention. Those findings might help to develop new classes of drugs which may supplement or replace classical anticoagulants and help clinicians to tackle CVD more efficiently.

Alteration of cytokine profiles in uranium miners exposed to long-term low dose ionizing radiation

Objective. The aim of the study is to estimate the immune function through cytokine profiles in sera of uranium mines. Methods. Antibody arrays were used to detect 50 cytokines in sera of uranium miners. Miners who had continuously worked underground for <5 years were treated as control group and those who worked for ⩾5 years as experimental group. Results. Of 28 measurable cytokines, the release of IL-1α, IL-1RI, IL-15, IL-3, and IP-10 were significantly upregulated in the experimental group, and no cytokine was found significantly downregulated. Other proinflammatory cytokines such as IFN-γ, IL-10, IL-6, and TNFα levels were slightly upregulated in the experimental group. With adjustment to age, BMI, and cigarette smoking, IL-1α and IL-3 levels increased significantly with underground time. Conclusion. Alteration of cytokine profiles in this study may indicate persistent inflammatory responses in uranium miners exposed to long-term low doses radiation.

Platelets in atherosclerosis

Beyond obvious functions in haemostasis and thrombosis, platelets are considered to be essential in proinflammatory surroundings such as atherosclerosis, allergy, rheumatoid arthritis and even cancer. In atherosclerosis, platelets facilitate the recruitment of inflammatory cells towards the lesion sites and release a plethora of inflammatory mediators, thereby enriching and boosting the inflammatory milieu. Platelets do so by interacting with endothelial cells, circulating leukocytes (monocytes, neutrophils, dendritic cells, T-cells) and progenitor cells. This cross-talk enforces leukocyte activation, adhesion and transmigration. Furthermore, platelets are known to function in innate host defense through the release of antimicrobial peptides and the expression of pattern recognition receptors. In severe sepsis, platelets are able to trigger the formation of neutrophil extracellular traps (NETs), which bind and clear pathogens. The present antiplatelet therapies that target key pathways of platelet activation and aggregation therefore hold the potential to modulate platelet-derived immune functions by reducing cellular interactions of platelets with other immune components and by reducing the secretion of inflammatory proteins into the milieu. The objective of this review is to update and discuss the current perceptions of the platelet immune constituents and their prospect as therapeutic targets in an atherosclerotic setting.

Platelet activation and inflammatory response in patients with non-dipper hypertension

OBJECTIVE

Non-dipper hypertensives had about three times the risk of atherosclerotic events than hypertensives whose blood pressure was >10% lower at night compared to daytime (dippers). Platelet activation and inflammatory response may derive from most atherosclerotic events. Mean platelet volume (MPV) is a determinant of platelet activation and high sensitive C-reactive protein (hs-CRP) is the best candidate assay to identify and monitor the inflammatory response. We aimed to determine whether MPV and hs-CRP levels are elevated in non-dipper patients compared to dippers and healthy controls. In addition, we tried to find out if MPV and CRP are related to each other or not in non-dipper hypertensives.

METHOD

The total 126 patients study group included 86 patients with hypertension and 40 healthy subjects (16 male, mean age; 51+/-4) as control. Ambulatory blood pressure monitoring was performed for all patients. Hypertensive patients were divided into two groups; 46 dipper patients (18 male, mean age; 50+/-9) and 40 non-dipper patients (17 male, mean age; 53+/-11). Clinical baseline characteristics were similar between groups. We measured mean platelet volume in a blood sample collected in EDTA tubes and high-sensitive CRP was measured by using BN2 model nephlometer.

RESULTS

Non-dipper patients demonstrated higher levels of MPV compared to dippers and normotensives (9.72+/-0.52 fl vs 9.38+/-0.33 fl and 8.92+/-0.42 fl, p<0.05, respectively). High-sensitive CRP levels were also significantly higher in non-dippers compared to dippers and normotensives (4.9+/-1.7mg/l vs 3.8+/-1.5mg/l and 2.7+/-0.8mg/l, p<0.05, respectively). There was significant positive correlation between MPV and CRP levels (p=0.002, r=0.482) in non-dipper hypertensives.

CONCLUSION

Our results suggest that patients with non-dipping tend to have increased platelet activation and inflammatory response. Increased platelet activation and inflammatory response could contribute to increase the atherosclerotic risk in non-dipper patients compared to dippers.

Pathophysiology of aortocoronary saphenous vein bypass graft disease

Aortocoronary saphenous vein bypass grafting relieves anginal pain in patients with coronary artery disease. However, its effectiveness is limited due to graft failure; the 10-year patency rate is 50%-60%. Early, 1-year and late graft failure may be due to thrombosis, fibrointimal hyperplasia and atherosclerosis, respectively. There is general agreement that vein graft atherosclerosis differs from arterial lesions in terms of temporal and histological changes. Vein graft atherosclerosis is more rapid, with diffuse concentric changes and a less noticeable fibrous cap, making venous plaques more vulnerable to rupture and subsequent thrombus formation. Despite progress in understanding the pathophysiology, some aspects of vein graft atherosclerosis need to be clarified. This review focuses on the pathophysiologic aspects of this widespread, costly and disabling disease, with emphasis on late graft occlusion and distinctions between arterial and venous atherosclerosis in terms of histology, pathophysiology and risk factors.

Endogenous interleukin-1 alpha promotes a proliferative and proinflammatory phenotype in human vascular smooth muscle cells

During vascular disease and following injury, vascular smooth muscle cells (VSMC) proliferate and produce inflammation-promoting cytokines and chemokines. Similar phenotypic changes can be elicited in vitro by activation of Toll-like receptors (TLR) within VSMC. TLR-activated VSMC also produce IL-1 alpha, but it is unknown whether endogenous IL-1 alpha stimulates VSMC in an autocrine manner. Here we tested the hypothesis that endogenous IL-1 alpha contributes to TLR-induced proliferation and chemokine release in human VSMC by using RNA interference to knock down IL-1 alpha expression. Knockdown of IL-1 alpha abolished TLR-induced proliferation and suppressed TLR4-induced release of monocyte chemoattractant protein-1 (MCP-1) by VSMC, indicating that endogenous IL-1 alpha plays a crucial role in both responses. Serum, PDGF, FGF-2, and EGF each increased cellular IL-1 alpha concentrations, and IL-1 alpha knockdown inhibited serum- and PDGF-induced DNA synthesis, further indicating that endogenous IL-1 alpha also contributed to VSMC responses to growth factors. IL-1 receptor antagonist, a competitive inhibitor of IL-1 receptor I (IL-1RI), also attenuated TLR-induced proliferation and both basal and TLR-induced MCP-1 expression, indicating at least a partial role of the IL-1RI in mediating these responses. The results support the hypothesis that autocrine actions of endogenous IL-1 alpha, mediated at least in part via IL-1RI signaling, contribute to a proproliferative and proinflammatory phenotypic shift in TLR-activated human VSMC, which might play a pathogenic role in vascular disorders.

Platelets as immune cells: bridging inflammation and cardiovascular disease

Beyond an eminent role in hemostasis and thrombosis, platelets are characterized by expert functions in assisting and modulating inflammatory reactions and immune responses. This is achieved by the regulated expression of adhesive and immune receptors on the platelet surface and by the release of a multitude of secretory products including inflammatory mediators and cytokines, which can mediate the interaction with leukocytes and enhance their recruitment. In addition, platelets are characterized by an enormous surface area and open canalicular system, which in concert with specialized recognition receptors may contribute to the engulfment of serum components, antigens, and pathogens. Platelet-dependent increases in leukocyte adhesion may not only account for an exacerbation of atherosclerosis, for arterial repair processes, but also for lymphocyte trafficking during adaptive immunity and host defense. This review compiles a selection of platelet-derived tools for bridging inflammation and vascular disease and highlights the molecular key components governing platelet-mediated mechanisms operative in immune surveillance, vascular remodeling, and atherosclerosis.

Juxtacrine effects of IL-1 alpha precursor promote iNOS expression in vascular smooth muscle cells

After injury to the blood vessel wall, vascular smooth muscle cells (SMC) synthesize interleukin (IL)-1 and inducible nitric oxide (NO) synthase (iNOS). The present study tested whether endogenous production of IL-1 alpha stimulates iNOS expression in vascular SMC, and assessed whether IL-1 alpha exerts autocrine effects on the cells producing IL-1 alpha or juxtacrine effects on cells that contact the IL-1 alpha producing cells. Rat aortic SMC were transiently transfected with expression plasmids encoding either IL-1 alpha precursor, which localizes to the plasma membrane, or mature IL-1 alpha, which remains cytosolic. iNOS mRNA levels, determined by RT-PCR, and production of nitrite, a stable oxidation product of NO, were markedly elevated in SMC overexpressing IL-1 alpha precursor, and modestly elevated in SMC overexpressing mature IL-1 alpha, relative to SMC transfected with vector alone. Exposure to exogenous IL-1 beta or TNF-alpha further stimulated iNOS gene expression in SMC producing IL-1 alpha; low levels of IL-1 beta (20 pg/ml) were effective in SMC transfected with IL-1 alpha precursor plasmid, whereas SMC transfected with mature IL-1 alpha plasmid or vector alone required higher concentrations of IL-1 beta (200 and 2,000 pg/ml, respectively). The increases in iNOS mRNA levels and NO production in SMC overexpressing IL-1 alpha precursor were prevented by exogenous IL-1 receptor antagonist, suggesting that these effects were mediated by the type I IL-1 receptor. Immunostaining studies indicated that IL-1 alpha precursor stimulates iNOS gene expression via cell-cell contact. Expression of iNOS was enhanced in cells that were in contact with a cell overexpressing IL-1 alpha precursor (identified by coexpression of green fluorescent protein), and in cells that were overexpressing IL-1 alpha themselves, but only when the cell contacted another cell. Together these results indicate that IL-1 alpha precursor acts by cell-cell contact as an autocrine and juxtacrine enhancer of iNOS gene expression, inducing moderate iNOS expression on its own, and markedly augmenting the responsiveness of rat aortic SMC to exogenous cytokines.

Relation of inflammation to vascular function in patients with coronary heart disease

Endothelium plays a pivotal role in the regulation of vascular relaxation. Inflammation may in turn induce endothelial dysfunction and thus increase the risk of atherothrombosis. We investigated 31 men with angiographically verified coronary heart disease, aged 57. 7+/-5.3 years, in regard to endothelium-dependent, acetylcholine-induced, and to endothelium-independent, sodium nitroprusside-induced vasodilatation in the forearm vasculature by strain-gauge plethysmography. Logistic regression analysis served to determine the relation between forearm vascular function and the inflammatory factors measured, concentration of C-reactive protein, subtypes of peripheral blood T-lymphocytes, and other factors potentially affecting endothelial function (lipoprotein and glucose levels). Concentration of C-reactive protein was an independent determinant of endothelium-dependent vascular function (P<0.001 for low dose acetylcholine, P=0.01 for high dose acetylcholine). Other determinants of endothelium-dependent vascular dysfunction were CD8-lymphocytes expressing ICAM-1 (P=0.001), antibodies to oxidized low-density lipoprotein (P<0.001), and body weight (P=0.007). The present data showed an association between inflammatory risk factors linked to atherothrombosis and endothelial dysfunction in coronary heart disease patients. It is possible that endothelial dysfunction in coronary heart disease patients is related to the chronic inflammation or infection coexisting with atherosclerosis.

Increasing levels of interleukin (IL)-1Ra and IL-6 during the first 2 days of hospitalization in unstable angina are associated with increased risk of in-hospital coronary events

BACKGROUND

A growing body of evidence suggests a role for inflammation in acute coronary syndromes. The aim of this study was to assess the role of proinflammatory cytokines, their time course, and their association with prognosis in unstable angina.

METHODS AND RESULTS

We studied 43 patients aged 62+/-8 years admitted to our coronary care unit for Braunwald class IIIB unstable angina. In each patient, serum levels of interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6) (which represent sensitive markers of biologically active IL-1beta and tumor necrosis factor-alpha levels, respectively), and troponin T were measured at entry and 48 hours after admission. Troponin T-positive patients were excluded. Patients were divided a posteriori into 2 groups according to their in-hospital outcome: group 1 comprised 17 patients with an uneventful course, and group 2 comprised 26 patients with a complicated in-hospital course. In group 1, mean IL-1Ra decreased at 48 hours by 12%, and IL-6 diminished at 48 hours by 13%. In group 2, IL-1Ra and IL-6 entry levels were higher than in group 1 and increased respectively by 37% and 57% at 48 hours (P<0.01).

CONCLUSIONS

These findings indicate that although they receive the same medical therapy as patients who do not experience an in-hospital event, patients with unstable angina and with complicated in-hospital courses have higher cytokine levels on admission. A fall in IL-1Ra and IL-6 48 hours after admission was associated with an uneventful course and their increase with a complicated hospital course. These findings may suggest novel therapeutic approaches to patients with unstable angina.

Constitutive expression of interleukin-1alpha precursor promotes human vascular smooth muscle cell proliferation

Vascular smooth muscle cell (VSMC) proliferation plays a critical role in the failure of vascular surgeries and contributes to the development of atherosclerotic lesions. Evidence that interleukin-1 (IL-1) is a mitogen for cultured VSMC has implicated its release by activated macrophages in the development of atherosclerosis. VSMC also produce IL-1, including the precursor form of IL-1alpha. However, it is not known whether IL-1alpha precursor is processed to mature IL-1alpha or released from VSMC, nor is it known whether either precursor or mature IL-1alpha functions as an autocrine growth factor. The goals of the present study were to establish whether proliferation is enhanced in human VSMC transfectants producing IL-1alpha constitutively at levels comparable to those produced after activation, and to determine which domains of IL-1alpha are important for its activity. Human VSMC were stably transfected with expression vectors directing constitutive expression of either full-length IL-1alpha precursor [IL-1alpha-(1-271)], its NH2-terminal domain [IL-1alpha-(1-112)], or mature IL-1alpha [IL-1alpha-(113-271)]. Both IL-1alpha-(1-271) and IL-1alpha-(113-271) stable transfectants produced moderate levels of IL-1alpha (0.2-1.0 ng/10(6) cells) and released low levels of IL-1alpha into the supernatant (<20 pg/ml). VSMC stably transfected with either IL-1alpha-(1-271) or IL-1alpha-(113-271) expression plasmids proliferated rapidly compared with nontransfected or vector-transfected VSMC and displayed a distinct morphology characterized by elongated, spindle-shaped cells. Stable transfection with IL-1alpha-(1-271) was somewhat more effective than transfection with IL-1alpha-(113-271). Interestingly, VSMC transfected with IL-1alpha-(113-271) expression plasmids also expressed IL-1alpha-(1-271) mRNA, suggesting that IL-1alpha-(113-271) activates an IL-1-induced IL-1 autocrine loop. In contrast, neither proliferation rates nor morphology was affected by stable transfection with IL-1alpha-(1-112) expression plasmids. Exogenous IL-1 receptor antagonist partially reversed the enhanced DNA synthesis in VSMC transfected with either IL-1alpha-(1-271) or IL-1alpha-(113-271) expression plasmids, suggesting that the pro-proliferative effect of VSMC-derived IL-1alpha is at least partially mediated by signaling via the type I IL-1 receptor. These results demonstrate that IL-1alpha precursor is an autocrine growth factor for human VSMC and further indicate that amino acids 113-271 play a crucial role in its actions.

Biologic activities of IL-1 and its role in human disease

The role of the polypeptide proinflammatory cytokine IL-1 family represents a group of proteins that have contrasting and synergistic biologic responses. IL-1alpha and beta and their precursor forms are heavily involved in the enhancement of inflammation and host defense. Within this family of gene products, there is also a naturally occurring receptor antagonist, IL-1ra, as well as a family of receptor proteins that have differential signaling functions and activities. The study of these proteins in human disease, including allergic disease and type 1 hypersensitivity responses, has led to a better understanding of the underlying general inflammation associated with these syndromes and has provided opportunities to look at new forms of intervention in allergic disease and asthma.

Histopathological features of in situ vein bypass stenoses

OBJECTIVES

To analyse the histopathological features of in situ vein bypass stenoses.

MATERIALS AND METHODS

Nineteen specimens of primary (n = 16) or recurrent (n = 3) vein graft stenoses obtained from 17 patients during surgical revision were prepared for light microscopy and immunohistochemical investigation. The median time interval from bypass surgery to stenosis excision was 5 months (range 2-52 months). Twenty-seven saphenous vein segments obtained from patients undergoing primary bypass surgery served as controls.

RESULTS

Graft stenoses were characterised by moderate to severe intimal hyperplasia composed of actin positive but desmin negative cells, interspersed with areas of fibrosis. A single layer of factor VIII positive endothelial cells were identified on the luminal surface. The media, separated from the intima by a poorly defined elastic lamina, usually appeared normal or mildly hyperplastic and consisted of smooth muscle cells, which stained positive for actin as well as for desmin. The adventitia was composed of loose connective tissue in which lymphocytes, plasma cells and giant cells were occasionally seen. Atheromatous material was absent from intragraft lesions, but was observed in one specimen, which was harvested from a proximal anastomotic lesion. The majority of pre-bypass vein segments showed evidence of intimal thickening whereas medial hyperplasia was less common.

CONCLUSIONS

In situ vein bypass stenoses mainly consisted of intimal hyperplasia and varying degrees of fibrosis. Similar but less pronounced morphological changes were found in pre-bypass vein segments. The nature of the actin positive but desmin and factor VIII negative intima cells is uncertain, and further studies are needed to characterise this cell type.

Vein quality influences neointimal hyperplasia in an organ culture model of human saphenous vein

OBJECTIVES

The severity of pre-existing pathological changes in human saphenous vein (HSV) correlates with the development of vein graft stenosis and graft patency. The aim of this study was to investigate the influence of pre-existing intimal hyperplasia on development of the neointima in vitro, using an organ culture model.

MATERIALS AND METHODS

Segments of HSV were harvested during coronary artery bypass surgery. Histology was performed on part of the vein; the remainder was maintained in culture. Pre-existing intimal thickness (PIT) in HSV from day 0 and neointimal thickness (NIT) in cultured HSV were measured using computerised image analysis on histological sections. Day 0 and 14 veins were compared with respect to intimal hyperplasia.

RESULTS

Twelve pairs of veins were examined. A mean tissue ATP of 297 nmoles/g wet weight for cultured. HSV confirmed cell viability. Mean PIT was 180 microns (CI: 86-274) and mean NIT was 60 microns (CI: 48-72), with a significant correlation between them using the Spearman Rank test (Rs = 0.72; p = 0.008).

CONCLUSIONS

Pre-existing vein quality as measured by PIT correlates with the development of neointimal hyperplasia in culture, adding further support to clinical evidence that poor vein quality predisposes to vein graft stenosis due to an inherent susceptibility to intimal hyperplasia.

In situ endothelin in coronary artery disease

Despite the significant advances made in the understanding and treatment of coronary artery disease much remains unclear about the pathogenesis of this complex atherothrombotic process. Atherogenesis may reflect a combination of multiple factors interacting with one another leading to coronary artery occlusion. One potential participant may be endothelin-1 (ET-1), a potent mitogenic vasoconstrictor. The presence of endothelin within saphenous veins before insertion and after removal during coronary artery bypass grafting (CABG) because of bypass closure, within internal mammary arteries before and after surgical intervention, and within native coronary artery segments resected during CABG was demonstrated immunocytochemically with an antiendothelin antibody and aminoethyl carbazole as the indicator chromogen. Increased amounts of ET-1 were observed in failed venous grafts, in damaged internal mammary artery grafts, and in vessels of the myocardium. These results suggest that ET-1 may play a significant pathophysiologic role in the evolution of coronary heart disease.

Increased serum concentrations of interleukin-1 beta in patients with coronary artery disease

OBJECTIVE

To assess serum interleukin-1 beta (IL-1 beta) concentrations in patients with ischaemic heart disease, to characterise subgroups of patients with raised IL-1 beta concentrations, and to examine whether serum IL-1 beta concentrations correlate with non-specific indices of inflammation.

DESIGN

Survey study of patients with ischaemic heart disease.

SETTING

Cardiac catheterisation laboratory of a tertiary medical centre.

PATIENTS

Consecutive patients with angina pectoris and patients recovering from uncomplicated acute myocardial infarction and undergoing elective coronary angiography.

RESULTS

Mean(SD) serum IL-1 beta concentrations were higher (P < 0.001) in patients with angina and < 50% coronary artery stenosis (n = 11; 18.8(19.9) pg/ml), patients with angina > or = 50% stenosis (n = 23; 10.2(11.4) pg/ml), and patients 8(0.8) days post-infarction (n = 13; 4.4(5.8) pg/ml) than in 15 healthy, age-matched controls (0.3(0.5) pg/ml). Serum IL-1 beta concentrations did not correlate with total blood leucocyte counts (r = -0.07, P = NS), blood lymphocyte counts (r = -0.24, P = NS), and blood monocyte counts (r = -0.29, P = NS), or with fibrinogen (r = -0.16, P = NS) and C-reactive protein concentrations (9(10.5) mg/dl v 14.1(19) mg/dl for patients with undetectable and detectable concentrations, respectively, P = NS).

CONCLUSION

Serum IL-1 beta concentrations are raised in patients with ischaemic heart disease, in particular in those with minimal coronary artery disease and angina. The precise role of IL-1 beta in coronary artery disease remains to be determined.

Anatomy of the internal mammary veins and their use in free TRAM flap breast reconstruction

The anatomy of 61 internal mammary veins (IMV) in the 3rd, 4th and 5th intercostal spaces was studied in 34 fresh human cadavers by injection and corrosion methods and surgical dissection. The IMV was present in all 34 cadavers. Four different patterns of venous anatomy were identified: Types 1 (69%) and 2 (26%) were common, Types 3 (3%) and 4(2%) were rare. The most common arrangement (Type 1) consists of the internal mammary vein running medial and parallel to the artery to the 4th intercostal space where it divides into the medial and the lateral IMV, the lateral crossing the internal mammary artery (IMA) anterior to it in direction from medial to lateral. Both veins are connected by interconnecting branches. The mean diameter of internal mammary veins is 2.7 mm (range 1.1-4.8 mm) for the medial and 1.8 mm (range 0.5-3.5 mm) for the lateral one. The mean distance from the lateral bordoffof the sternum of the medial vein is 9 mm (range 2-18 mm) and 14 mm (range 9-24 mm) for the lateral vepfpff. We present a review of 7 patients in whom internal mammary vessels were used as recipient vessels for breast reconstruction with free TRAM flaps with no complications, as well as the advantages and disadvantages of such a procedure.

Vein graft factors in the outcome of femorodistal bypass

Various vein factors affect the outcome of femorodistal bypass using vein in the treatment of lower limb ischaemia. In this review, the effect of factors such as vein size, compliance and morphology are discussed.

Therapeutic approaches to the control of fibrocellular intimal hyperplasia after angioplasty

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Circulating levels of soluble interleukin 2 receptors are elevated in the sera of humans with spinal cord injury

A unique molecular regulatory mechanism or final common molecular pathway mediating the autonomic dysfunction and several pathobiologic sequelae of spinal cord injury (SCI) in humans has not been delineated. Although seemingly disparate in etiopathogenesis, much of the pathology caused by traumatic disruption of the spinal cord may be attributable to the pleiotropism demonstrated by a unique family of endogenous bioactive molecules, the interleukins. To begin testing this hypothesis, we examined the sera of patients with chronic SCI for elevations in interleukin 1 beta (IL-1 beta) and interleukin 2 receptor (IL-2R) and compared them to a control population of able-bodied subjects. In comparison to control subjects, a statistically significant increase in IL-2R was observed in patients with cervical spinal myelopathy. Elevated levels of IL-2R were not seen in paraplegic patients. Significant differences between the means and variances of serum IL-1 beta could not be detected among the study groups. We conclude that the sera of quadriplegic patients with chronic SCI contain elevated levels of IL-2R and suggest that the elevated levels of IL-2R may be of diagnostic, prognostic, and therapeutic importance.