Study of energetic properties of different tree organs in six Olea europaea L. cultivars

Pruning is an important horticultural practice for the management of olive orchards (Olea europaea L.) that generates a considerable amount of residues every year. Olive orchards are increasingly expanding beyond the Mediterranean Basin to new growing Countries (Australia, California, Argentina, Chile and Uruguay) and this will certainly lead to larger availability of pruning material. Currently, the interest in use of olive tree pruning residues for energy purposes is increasing but unfortunately, the information on the differences among organs of the tree, in terms of calorific value and ash content, is scarce. Another unknown aspect is the effect of cultivar vigour on dry matter partition among different tree organs, these are important traits to establish the energetic quality of pruning residues. The aim of this research was to study energetic aspects of six olive cultivars, largely grown in the Sicilian olive industry and characterized by different vigour. The trees taken into consideration in the study were selected in an experimental orchard to avoid any effect due to differences in environmental conditions and management. The energetic characteristics, calorific value and ash content, were evaluated for the various tree organs particularly shoots, leaves and branches; also root system was evaluated, although the roots can only be used once the trees are uprooted. Significant differences were observed in the calorific values among the different tree organs and the cultivars. Regarding the ash, shoots and leaves showed the highest content with respect to the other organs, thus causing a possible tendency in slagging with fouling and corrosion of boiler components.

Concomitant carotid endarterectomy and coronary bypass surgery: should cardiopulmonary bypass be used for the carotid procedure?

BACKGROUND AND OBJECTIVES

With the increasing age of patients undergoing coronary artery bypass grafting (CABG), a greater number have associated clinically significant carotid disease. This study determined the morbidity and mortality for combined carotid endarterectomy (CEA)/CABG using cardiopulmonary bypass (CPB) for both procedures versus a combined approach using CPB only during CABG.

PATIENTS AND METHODS

Between 1993 and 2000, 65 patients (Group I) underwent combined CEA and CABG using CPB for both surgical procedures and 88 patients (Group II) underwent combined CEA and CABG using CPB only during CABG. The demographic, clinical, and carotid and coronary angiographic data were similar between groups. In Group I, 22 (33.8%) patients and 32 (36%) patients in Group II presented with contralateral carotid artery stenosis.

RESULTS

CPB time was significantly longer in Group I, 127+/-21 minutes versus 98+/-11 minutes in Group II patients (p = 0.001). The incidence of surgical revision for bleeding and deep sternal wound infection was higher in Group I patients, 2 (3%) versus 1 (1.1%) and 5 (7.7%) versus 2 (2.2%), respectively, but not significant. Hospital mortality in Group I was 6% (4 patients) versus 5.7% (5 patients) in Group II (p = ns). Neurologic complications occurred in 4 (6%) and 5 (5.7%) patients in Group I and II, respectively (p = ns). Postoperative renal dysfunction was more common in Group I patients (22 [33.8%]) then in Group II patients 16 (19%) (p = 0.04). Of these patients, (16 [19%]) 8 (12.3%) in Group I and 6 (6.8%) in Group II required postoperative ultrafiltration (p = ns). Infectious complications were more frequent in Group I patients, 5 (7.7%) versus 2 (2.3%), but not statistically significant (p = ns). Overall actuarial survival at 1, 3, and 5 years, including all deaths, was 92%, 88%, and 82% in Group I versus 93%, 86%, and 81% in Group II (p = ns). Overall freedom from stroke at 5 years was 87.5% in Group I and 86.4% in Group II.

CONCLUSIONS

We conclude that combined CEA/CABG using CPB only during the myocardial revascularization procedure remains the technique of choice in patients with coronary and carotid artery disease, offering better outcome in terms of perioperative morbidity than a combined CEA/CABG using CPB for both procedures.

Beating heart myocardial revascularization on extracorporeal circulation in patients with end-stage coronary artery disease

OBJECTIVES

To evaluate in a cohort of ESCAD patients (pts) the effects of on-pump/beating-heart versus conventional CABG in terms of early and mid-term survival and morbidity and LV function improvement.

METHODS

Between January 1993 and December 2000, 78 (Group I) ESCAD pts underwent on-pump/beating-heart surgery. Mean age in Group I was 66.2+/-6 (58-79), NYHA and CCS class were 3.2+/-0.6 and 3.3+/-0.4 respectively, Myocardial viability index 0.69+/-0.1 (%), LVEF (%) 24.8+/-4, LVEDP (mmHg) 28.1+/-5.8 and LVEDD(mm) 69.5+/-6. Group II consisted in 78 ESCAD patients undergoing conventional CABG selected in a randomized fashion from an age, sex, and LVEF corrected group of patients. Mean age in Group II was 65.7+/-5 (57-78), NYHA 3.1+/-0.7, CCS 3.4+/-0.8, LVEF(%) 25+/-5, LVEDP(mmHg) 27.9+/-4.4 and LVEDD(mm) 69.2+/-7.2.

RESULTS

Postoperatively, 5(7.7%) patients died in Group I versus 7(11.5%) patients in Group II (P>0.1). CPB time resulted to be in Group II patients (P=0.001) and the mean distal anastomoses per patient was similar between groups (P=Ns). Perioperative AMI (P=0.039), LCOS (P=0.002), necessity for ultrafiltration (P=0.018) and bleeding>1000 ml (P=0.029) were significantly higher in Group II. None of the Group I patients underwent surgical revision for bleeding versus 8(10.3%) patients in Group II (P=0.011). At 6 months after surgery, the LV function improved significantly in Group I patients, demonstrated by an increased LVEF=27.2+/-4(%)(P=0.001), lower LVEDP=26.4+/-3(mmHg)(P=0.029) and LVEDD=67+/-4(mm) (P=0.004) instead of a lower LVEDD=66.8+/-6(mm)(P=0.032) versus the preoperative data in Group II. The actuarial survival at 1, 3 and 5 yr were 90, 82 and 71% in Group I and 89, 83 and 74% in Group II (P=Ns).

CONCLUSION

In ESCAD patients who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers a better myocardial and renal protection associated with lower postoperative complications due to intraoperative hypoperfusion.

Should mild-to-moderate and moderate ischemic mitral regurgitation be corrected in patients with impaired left ventricular function undergoing simultaneous coronary revascularization?

INTRODUCTION

Mitral valve regurgitation (MR) occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction predicts poor outcome. This study assessed the feasibility of mitral valve (MV) surgery concomitant with coronary artery bypass grafting (CABG) in patients with mild-to-moderate and moderate ischemic MR and impaired LV function.

MATERIALS AND METHOD

From January 1996 to July 2000, 49 patients (group 1) and 50 patients (group 2) with grade II and grade III ischemic MR and LV ejection fraction (EF) between 17% and 30% underwent combined MV surgery and CABG (group 1) or isolated CABG (group 2). LVEF (%), LV end-diastolic diameter (EDD) (mm), LV end-diastolic pressure (EDP) (mmHg), and LV end-systolic diameter (ESD) (mm) were 27.5 +/- 5, 67.7 +/- 7,27.7 +/- 4, and 51.4 +/- 7, respectively in group 1 versus 27.8 +/- 4, 67.5 +/- 6, 27.5 +/- 5, and 51.2 +/- 6, respectively in group 2. Groups 1 and 2 were divided into Groups 1A and 2A with mild-to-moderate MR (22 [45%] and 28 [56%] patients, respectively) and groups 1B and 2B with moderate MR (27 [55%] and 22 [46%], respectively). In group 1, MV repair was performed in 43 (88%) patients and MV replacement in 6 (12%) patients.

RESULTS

Preoperative data analysis did not reveal any difference between groups. Five (10%) patients in group 1 died versus 6 (12%) in group 2 (p = ns). Within 6 months after surgery, LV function and its geometry improved significantly in group 1 versus group 2 (LVEF, p < 0.001; LVEDD, p = 0.002; LVESD, p = 0.003; and LVEDP (p < 0.001) improved significantly in group 1 instead of a mild improvement in Group 2). The regurgitation fraction decreased significantly in group 1 patients after surgery (p < 0.001). There was an inverse strong correlation between postoperative forward cardiac output and regurgitation fraction (p < 0.001). LVEF and LVESD improved significantly in group 1 versus group 2 patients (p = 0.04 and p = 0.02, respectively). The cardiac index increased significantly in group 1 and 2 (p < 0.001 and p = 0.03, respectively). LV function and geometry improved significantly postoperatively in group 1B versus group 2B (LVEDD, p = 0.027; LVESD, p = 0.014; LVEDP, p = 0.034; and LVEF, p = 0.02), instead of a mild improvement in group 1A versus group 2A (LVESD, p = 0.015; LVEF, p = 0.046; and LVEDD and LVEDP, p = 0.05). At follow-up, 4 (67%) of 6 patients undergoing MV replacement died versus 5 (11.5%) of 43 patients undergoing MV repair in group 1 (p = 0.007). The overall survival at 3 years in Group 2 was significantly lower than group 1 (p < 0.009).

CONCLUSION

MV repair and replacement-preserving subvalvular apparatus in patients with impaired LV function offered acceptable outcomes in terms of morbidity and survival. Surgical correction of mild-to-moderate and moderate MR in patients with impaired LV function should be taken into consideration since it yields better survival and improved LV function.

Lambda graft with the radial artery or free left internal mammary artery anastomosed to the right internal mammary artery: flow dynamics

BACKGROUND

The aim of this study was to evaluate the outcome and flow dynamics of the lambda graft configuration, relative to a second arterial graft.

METHODS

From 1998 to 2000, 47 patients (mean age 55.5 +/- 4.7 years) with triple-vessel disease underwent arterial revascularization using the lambda graft. The in situ left internal mammary artery (LIMA) and right internal mammary artery (RIMA) were anastomosed to the left anterior descending (LAD) and obtuse marginal arteries, respectively. In 21 patients (group I) presenting proximal or middle-third LAD or right coronary (RC) arterial stenoses, the lambda graft was constructed by anastomosing the distal LIMA, as a free LIMA graft, to the RC and proximally to the in situ RIMA. In the other 26 patients (group II) presenting with middle-distal third LAD or RC arterial stenoses, the radial artery (RA) was used to construct the lambda graft. All patients underwent transthoracic echo color Doppler before and after an adenosine test at 1 week and 3 months after operation.

RESULTS

There were no hospital deaths. Overall, 47 lambda grafts were constructed. There was no difference between baseline and maximal flows and coronary flow reserve (CFR) between groups. CFR at IMA stems increased in both groups within 3 months versus 1 week [(LIMA)CFR = 2 +/- 0.3 vs 2.3 +/- 0.3 (p = 0.002) and (RIMA)CFR = 2.2 +/- 0.4 vs 2.5 +/- 0.3 (p = 0.009) in group I, and (LIMA)CFR = 2.12 +/- 0.33 vs 2.4 +/- 0.35 (p = 0.005) and (RIMA)CFR = 2.17 +/- 0.32 vs 2.52 +/- 0.26 (p = 0.001) in group II]. At 3 months versus 1 week, the (RIMA)diameter(i) (mm) at rest was 1.69 +/- 0.32 versus 1.48 +/- 0.2 (p = 0.015) in group I and 1.66 +/- 0.3 versus 1.47 + 0.2 (p = 0.01) in group II. At 6 +/- 2.4 months, all patients were free of angina.

CONCLUSIONS

These data, almost identical for free LIMA and RA to RIMA using the lambda graft, demonstrate that RIMA flow reserve is adequate for multiple coronary anastomoses irrespective of the second arterial graft.

Does on-pump/beating-heart coronary artery bypass grafting offer better outcome in end-stage coronary artery disease patients?

OBJECTIVES

The purpose of our study was to evaluate in a cohort of end-stage coronary artery disease (ESCAD) patients the effects of on-pump/beating-heart versus conventional coronary artery bypass grafting (CABG) requiring cardioplegic arrest. We report early and midterm survival, morbidity, and improvement of left ventricular (LV) function.

METHODS

Between January 1992 and October 1999, 107 (Group I) ESCAD patients underwent on-pump/beating-heart surgery and 191 (Group II) ESCAD patients underwent conventional CABG requiring cardioplegic arrest. Mean age in Group I was 65.8 +/- 6.5 years (58-79 years); New York Heart Association (NYHA) and Canadian Cardiovascular Society (CCS) classifications were 3.2 +/- 0.4 and 3.3 +/- 0.5, respectively. LV ejection fraction (LVEF) was 24.8% +/- 4%, LV end diastolic pressure (LVEDP) was 28.2 +/- 3.8 mmHg, and LV end diastolic diameter (LVEDD) was 69.6 +/- 4.6 mm. Mean age in Group II was 64.1 +/- 5 years (57-76 years), NYHA class was 3 +/- 0.6, CCS class was 3.4 +/- 0.4, LVEF was 26.2% +/- 4.3%, LVEDP was 27.2 +/- 3.4 mmHg, and LVED was 68 +/- 4.2 mm.

RESULTS

Preoperatively, Group I patients versus Group II patients had a markedly depressed LV function (LVEF, p = 0.006; LVEDP, p = 0.02; LVEDD, p = 0.003; and NYHA class, p = 0.002), older age (p = 0.012), and higher incidences of multiple acute myocardial infarction (AMI; p = 0.004), cardiovascular disease (CVD; p = 0.008), and chronic renal failure (CRH, p = 0.002). Cardiopulmonary bypass (CPB) time was longer in Group II patients (p = 0.028). The mean distal anastomosis per patient was similar between groups (p = NS). Operative mortality between Groups I and II was 7 (6.5%) and 19 (10%), respectively (p = NS). Perioperative AMI (p = 0.034), low cardiac output syndrome (LCOS; p = 0.011), necessity for ultrafiltration (p = 0.017), and bleeding (p = 0.012) were higher in Group II. Improvement of LV function within 3 months after the surgical procedure was markedly higher in Group I, demonstrated by increased LVEF (p = 0.035), lower LVEDP (p = 0.027), and LVEDD (p = 0.001) versus the preoperative data in Group II. The actuarial survivals at 1, 3, and 5 years were 95%, 86%, and 73% in Group I and 95%, 84%, and 72% in Group II (p = NS).

CONCLUSIONS

ESCAD patients with bypassable vessels to two or more regions of reversible ischemia can undergo safe CABG with acceptable hospital survival and mortality and morbidity. In higher risk ESCAD patients, who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers better myocardial and renal protection associated with lower postoperative complications.

An immunohistochemical study of the compartmentation of metabolism during the development of grape (Vitis vinifera L.) berries

The compartmentation of key processes in sugar, organic acid and amino acid metabolism was studied during the development of the flesh and seeds of grape (Vitis vinifera L.) berries. Antibodies specific for enzymes involved in sugar (cell wall and vacuolar invertases, pyrophosphate: fructose 6-phosphate phosphotransferase, aldolase, NADP-glyceraldehyde-P dehydrogenase, cytosolic fructose 1,6-bisphosphatase), photosynthesis (Rubisco, fructose 1,6-bisphosphatase, sedoheptulose 1,7-bisphosphatase), amino acid metabolism (cytosolic and mitochondrial aspartate aminotransferases, alanine aminotransferase, glutamate dehydrogenase, glutamine synthetase), organic acid metabolism (phosphoenolpyruvate carboxylase, NAD- and NADP-dependent malic enzyme, ascorbate peroxidase), and lipid metabolism (acetyl CoA carboxylase, isocitrate lyase) were used to determine how their abundance changed during development. There were marked changes in the abundance of many of these enzymes in both the flesh and seeds. The intercellular location of some enzymes was investigated using immunohistochemistry. Several enzymes (e.g. phosphoenolpyruvate carboxylase and those involved in amino acid metabolism) were associated with tissues likely to function in the transport of imported assimilates, such as the vasculature. Although other enzymes (e.g. NADP-malic enzyme and soluble acid invertase, involved in the metabolism of sugars and organic acids) were largely present in the parenchyma cells of the flesh, their distribution was extremely heterogeneous. This study shows that when considering the metabolism of complex structures such as fruit, it is essential to consider how metabolism is compartmentalized between and within different tissues, even when they are apparently structurally homogeneous.

An immunohistochemical study of the compartmentation of metabolism during the development of grape (Vitis vinifera L.) berries

The compartmentation of key processes in sugar, organic acid and amino acid metabolism was studied during the development of the flesh and seeds of grape (Vitis vinifera L.) berries. Antibodies specific for enzymes involved in sugar (cell wall and vacuolar invertases, pyrophosphate: fructose 6-phosphate phosphotransferase, aldolase, NADP-glyceraldehyde-P dehydrogenase, cytosolic fructose 1,6-bisphosphatase), photosynthesis (Rubisco, fructose 1,6-bisphosphatase, sedoheptulose 1,7-bisphosphatase), amino acid metabolism (cytosolic and mitochondrial aspartate aminotransferases, alanine aminotransferase, glutamate dehydrogenase, glutamine synthetase), organic acid metabolism (phosphoenolpyruvate carboxylase, NAD- and NADP-dependent malic enzyme, ascorbate peroxidase), and lipid metabolism (acetyl CoA carboxylase, isocitrate lyase) were used to determine how their abundance changed during development. There were marked changes in the abundance of many of these enzymes in both the flesh and seeds. The intercellular location of some enzymes was investigated using immunohistochemistry. Several enzymes (e.g. phosphoenolpyruvate carboxylase and those involved in amino acid metabolism) were associated with tissues likely to function in the transport of imported assimilates, such as the vasculature. Although other enzymes (e.g. NADP-malic enzyme and soluble acid invertase, involved in the metabolism of sugars and organic acids) were largely present in the parenchyma cells of the flesh, their distribution was extremely heterogeneous. This study shows that when considering the metabolism of complex structures such as fruit, it is essential to consider how metabolism is compartmentalized between and within different tissues, even when they are apparently structurally homogeneous.

Fluid shear stress increases the release of platelet derived growth factor BB (PDGF BB) by aortic endothelial cells

OBJECTIVES

The aim of this study was to determine the correlation between shear stress and the release of Platelet Derived Growth Factor (PDGF BB) by aortic endothelial cells.

DESIGN AND SETTING

Laboratory in vitro study.

MATERIALS

Bovine aortic endothelial cells were seeded in fibronectin-coated cylinders at 1.0 x 10(6) cells/tube and allowed to reach confluence and to adhere for 48 hours. The experimental groups were subjected to nonpulsatile, laminar flow of 50, 100, 150 ml/min in polystyrene cylinders (i.d. 10 mm) of a closed circulatory loop giving a shear stress on the endothelial cells of 3, 6, 9 dyn/cm2. The control group was subjected to similar incubation conditions without flow.

OUTCOME MEASURES

The release of PDGF BB by endothelial cells was measured by ELISA and Western Blot Analysis.

RESULTS

Shear stress increased significantly (p < 0.01) the release of PDGF BB by endothelial cells.

CONCLUSIONS

PDGF BB release by endothelial cells may be one of the mechanisms linking hemodynamic forces and adaptation of blood vessels wall.

Growth factors and myointimal hyperplasia in experimental aortic allografts

OBJECTIVES

To analyse the role of growth factors (platelet derived growth factor, PDGF; basic fibroblast growth factor, bFGF; interleukin 1, IL-1) in the genesis of myointimal hyperplasia in arterial allografts.

MATERIALS

Two groups of experiments were performed: isografts and allografts. The isograft group consisted of 15 inbred Lewis rats in which a 1 cm long segment of aorta was inserted as an abdominal aortic interposition graft. The aortic segments were obtained from syngenic Lewis rats. The allograft group consisted of 15 inbred Lewis rats, in which a 1 cm long segment of aorta was interposed at the abdominal aorta level. The aortic segments were obtained from allogenic Brown-Norway rats.

CHIEF OUTCOME MEASURES

The animals were killed 4 weeks after surgery and were analysed by morphometric analysis (n = 3 for each group). In addition, production of PDGF, bFGF and IL-1 by aortic segments (n = 12 for each group) in organ culture was assessed.

MAIN RESULTS

Allografts had more myointimal hyperplasia, than isografts (p < 0.05). PDGF and bFGF production, generally considered to be the cause of myointimal hyperplasia, was not increased in allografts. IL-1 production was higher in allografts (p < 0.001).

MAIN CONCLUSIONS

Myointimal hyperplasia in aortic allografts is dependent on growth factors produced by the graft itself. These growth factors are different from PDGF and bFGF that generally have been implicated in the genesis of naturally occurring myointimal hyperplasia and atherosclerosis. IL-1 may have a principal role in the genesis of myointimal hyperplasia in arterial allografts.

Hemodynamic forces modulate simultaneously the release of growth factors and the organisation of cytoskeleton of aortic smooth muscle-cells

Recurrent stenosis because of myointimal hyperplasia or atherosclerosis after carotid endarterectomy occurs in 5-15% of the cases. The key event is the abnormal proliferation of arterial Smooth Muscle Cells (SMC). After endarterectomy SMC are directly exposed to the blood flowing under pressure. The aim of the present study was to determine the changes in morphology, cytoskeleton organisation, and release of growth factors by SMC exposed to laminar flow. Subconfluent SMC were exposed to a level of shear stress of 6 dyne/cm2 (100 ml/min) for 24 hours under conditions of steady laminar flow. The changes in morphology and cytoskeleton organisation were analysed by light and scanning electron microscopy, and by fluorescence microscopy. Growth factors release was assessed by ELISA. After exposure to laminar flow, SMC assumed a spindle-like shape; they lost many of their protrusions and there was a clear reorganisation of the cytoskeleton and simultaneously their released a higher quantity of PDGF and bFGF. In this study, we found simultaneous changes in cytoskeleton organisation and release of growth factors in SMC exposed to flow. Cytoskeleton reorganisation might be the mechanism through which SMC respond to changes in blood flow. These findings may help to explain the genesis of myointimal hyperplasia following carotid endarterectomy.

Growth factor production by arterial and vein grafts: relevance to coronary artery bypass grafting

BACKGROUND

Occlusion caused by myointimal hyperplasia, atherosclerosis, or both is the main reason for late failure of saphenous vein coronary artery bypass grafts. On the other hand, internal mammary artery grafts are usually spared from atherosclerosis. Evidence exists that platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) are involved in the genesis of myointimal hyperplasia and atherosclerosis. The aim of this study was to assess the production of PDGF and bFGF by arterial and vein grafts.

METHODS

In 20 inbred Lewis rats alpha 1 cm long segment of arterial graft was interposed at the level of the abdominal aorta. In a control group of 20 Lewis rats alpha 1 cm long segment of vein graft was implanted at the level of the abdominal aorta. Animals were killed 4 weeks after operation, and the grafts were studied in serum-free organ culture to assess the production of PDGF and bFGF. RESULTS. Arterial grafts produced a smaller quantity of PDGF and bFGF than vein grafts (p < 0.01) Higher mitogenic activity was present in the conditioned media from vein grafts than in the conditioned media from arterial grafts (p < 0.001). A large amount of myointimal hyperplasia was present in all vein grafts.

CONCLUSIONS

This phenomenon could explain the rarity of atherosclerotic changes in internal mammary coronary bypass grafts.