Distal Bed Research Articles

Hypospadias

Hypospadias is one of the most common congenital anomalies in men. We searched the recent literature (since 1 January 2011) using the following keywords in the title or abstract: hypospadia or hypospadias, in order to provide the reader with an updated view of the subject. Early repair is recommended; distal forms are mainly treated by the tubularized incised plate technique; however, meatal stricture concerns are still noticed, limiting its use on proximal forms. The debate of proximal primary repair in either one or two stages is still ongoing. Minor modifications for preparing the distal bed for the urethroplasty in two stages are presented. One-stage repairs, either with reconstruction of the urethral plate (three-in-one concept) or simply with the onlay to tunica albuginea (Rigamonti), is a viable option with over 70% success in one surgery. The importance of barriers, such as tunica vaginalis and dartos flap, was reassessed and flow rates may indicate obstructive voiding patterns after 1-year follow-up. Further experience and comparative studies for distal and proximal hypospadias are required. Long-term data may indicate the appropriate procedure selected for primary repair.

Repair of partial loss of distal finger nail bed

Objective To investigate the method of repair for partial loss of the distal finger nail bed.Methods A total of 30 cases with partial loss of the distal finger nail bed were treated with volar advancement flap,unilateral or bilateral V-Y advancement flap along with modified nail augmentation based on the level of injury and the remaining portion of the nail. Results All flaps survived.One year postoperative follow-up (range,6 to 24 months) revealed that the texture,color and sensation of the fingertips were good.The appearance of the nails was satisfactory. Conclusion Local advancement flap combined with modified nail augmentation is an ideal method for cosmetic repair of partial loss of distal finger nail bed.It restores the length and appearance of the distal finger nail. Key words: Surgical flaps; Nails; Nailed augmentation

WHAT IS THE BEST ACCESS FOR ANGIOGRAPHY IN PATIENTS WITH A SINGLE IN-SITU LEFT MAMMARY ARTERY GRAFT

Methods: from a prospective database between Jan 2009 and Oct 2011 of 557 coronary angiography in patients treated with at least one mammary graft, we extracted 341 angiography in patients with one Left Mammary graft (14 operators). Quality of left mammary angiography was assessed by one independent reviewer: 1 or 2 respectively for selective or subselective truly diagnostic angio (graft, anastomosis and distal bed), 3 for non selective good visualization of graft and partial analysis of distal vessels, 4 for graft patency or not diagnosis only. Continuous variables are described as median and interquartile ranges (25th/75th), comparisons are done using non parametric statistics.

IS THE RIGHT RADIAL ACCESS AN ACCEPTABLE APPROACH FOR CORONARY ANGIOGRAPHY IN PATIENTS WITH AN IN-SITU LEFT MAMMARY GRAFT?

Methods: From a prospective database of 557 coronary angiographies in patients with at least one mammary graft between Jan 2009 and Oct 2011, we extracted 30 coronary angiography including injection of the Left Mammary graft from right radial access performed by a single operator using this technique for more than ten years. This group was compared to a population of Femoral approaches in the same subset performed by 14 operators (n= 183). Quality of mammary graft angio was attested by an independent reviewer: 1 or 2 respectively for selective or subselective completely diagnostic angio (graft, anastomosis and all distal vessels), 3 for non selective good visualization of graft and partial analysis of distal bed, 4 for graft patency or not diagnosis only.

WHAT IS THE BEST APPROACH FOR ANGIOGRAPHY OF DOUBLE IN-SITU MAMMARY GRAFTS?

Methods: from a prospective database of 557 coronary angiographies in patients with at least one mammary graft between Jan 2009 and Oct 2011, we extracted 166 procedures with 2 in situ mammary grafts, in order to compare different approaches (14 operators). Quality of mammary graft angio was attested by an independent reviewer: 1 or 2 respectively for selective or subselective completely diagnostic angio (graft, anastomosis and all distal vessels), 3 for non selective good visualization of graft and partial analysis of distal bed, 4 for graft patency or not only.

Managing Severe Upper Extremity Ischemia from Mobile Aortic Arch Thrombus: A Novel Approach Using Isolated Limb Perfusion with Tissue Plasminogen Activator

Etiologies of upper extremity ischemia are numerous and include embolic aortic pathology. Traditional operative management for this entity includes open thrombectomy, catheter directed thrombolysis and/or percutaneous mechanical thrombectomy. These conventional options, however, may not be ideal for patients having unstable aortic arch thrombus and profound distal arterial thrombosis of the hand. An alternative approach for such patients is isolated limb perfusion (ILP) with tissue plasminogen activator (tPA). A 37-year-old female presented with sudden onset acute left hand ischemia associated with sensory and motor deficits. An axillary pulse was present and distal pulses were absent as were radial, ulnar and palmar signals. Her medical history was unremarkable but she was a 1 pack/day smoker. Her evaluation included a chest CT-angiogram showing a pedunculated aortic arch thrombus that was confirmed on transthoracic echocardiogram (TTE) and was mobile (Fig 1). Her hand ischemia was presumed to be caused by an embolus originating from the aortic arch. Given the severity of distal forearm and hand ischemia with the presence of mobile aortic thrombus, catheter directed thrombolysis was felt to be contraindicated and the patient was taken to the operating room (OR) for emergent brachial, radial and ulnar thrombectomy. This yielded some thrombus; however, an intraoperative angiogram (Fig 2, A) post-thrombectomy still showed significant residual hand thrombus with absent radial, ulnar and palmar signals. Further thrombectomy was felt to be ineffective and ILP with tPA was felt to be most appropriate. A perfusion circuit was constructed and connected to the patient via brachial artery and vein cannulas. A proximal arm tourniquet was placed. The perfusate was charged with 25 mg tPA/hour for a total circulation time of 2 hours at a flow rate of 200 cc/min. Fibrinogen levels remain unchanged during perfusion. After completing perfusion, a repeat angiogram (Fig 2, B) was performed showing marked thrombus resolution. The cannula sites and incision were closed. The patient then underwent left postero-lateral thoracotomy and open aortic thrombectomy without cardiopulmonary bypass. At 6 months follow-up, radial and ulnar pulses are present and without sensory or motor hand deficits. Prompt open surgical thrombectomy remains first line therapy for cases of acute severe upper extremity ischemia due to thromboembolism although it may be ineffective for distal arterial bed thrombus. Alternatively, catheter-directed thrombolysis is effective for distal bed thrombus. However, this is precluded in advanced ischemia and when systemic tPA exposure is contraindicated due to risk of further embolization from proximal thrombus. ILP with tPA allows for rapid distal bed thrombolysis while theoretically limiting systemic exposure. In circumstances where perfusion circuits are readily available, it is possible to utilize ILP with tPA as an alternative strategy when conventional treatment methods are deemed to be suboptimal.

Treatment of dialysis access-associated steal syndrome with pressure monitorization-assisted PTFE banding

Background: We evaluated the mid-term effects on the fistula patency and clinical results of our technique of banding combined with pressure measurement from the distal bed. Methods: The mid-term results of 20 patients who were diagnosed with symptomatic steal syndrome by clinical and Doppler USG evaluation and treated with arterially pressure monitorized polytetrafluoroethylene (PTFE) banding method between January 2002 - December 2009 were studied. All the patients had aneurysmatic brachiocephalic arteriovenous fistula (AVF). Peroperatively, blood pressure was monitorized from the proximal of the fistula, brachial artery and radial artery and the radial/ brachial index values were recorded. Fistulas were constricted until the lower treshold of the radial-brachial index became 0.6. For the banding procedure PTFE grafts long enough to completely cover the aneurysmatic segment were used. Postoperatively, patients were asked to return for follow-ups within the 1st month and at three-month intervals thereafter. The fistula patency and the symptoms were evaluated and recorded in the follow-ups. Results: Symptoms were not alleviated in three patients at the 1st month follow-up. These patients underwent rebanding. In the remaining patients no early or late complications developed. All patients could receive hemodialysis in the early period and the symptoms were resolved. Other than the two patients who underwent rebanding, no cases of thrombosis were detected at the end of the first year. Conclusion: The main surgical procedures for surgical treatment of post-AVF steal syndrome are distal revascularization-interval ligation, banding, T-banding, graft interpositioning and AVF ligation. There are no large surgery studies involving patients treated with these methods. While banding procedure is technically easy, insufficient banding causes perpetuation of steal syndrome and more than necessary constriction causes thrombosis. In this study one year patency and thrombosis rates were 90% and 10%, respectively and the rate of relief of symptoms was 95%. We think that controlled banding with brachial and radial artery pressure monitoring reduces risk of fistula thrombosis and repeat procedures for insufficient constructions.

Utilização da safena magna in situ para arterialização do arco venoso do pé

CONTEXTO: O tratamento da isquemia crítica de membros inferiores sem leito arterial distal pode ser realizado por meio da inversão do fluxo no arco venoso do pé. OBJETIVO: O objetivo deste trabalho foi apresentar a técnica e os resultados obtidos com a arterialização do arco venoso do pé, mantendo a safena magna in situ. MÉTODOS: Dezoito pacientes, dos quais 11 com aterosclerose (AO), 6 com tromboangeíte obliterante (TO) e 1 com trombose de aneurisma de artéria poplítea (TA) foram submetidos ao método. A safena magna in situ foi anastomosada à melhor artéria doadora. O fluxo arterial derivado para o sistema venoso progride por meio da veia cujas válvulas são destruídas. As colaterais da veia safena magna são ligadas desde a anastomose até o maléolo medial, a partir do qual são preservadas. RESULTADOS: Dos pacientes, 10 (55,6%) mantiveram suas extremidades, 5 com AO e 5 com TO; 7 (38,9%) foram amputados, 5 com AO, 1 com TO e 1 com Ta; houve 1 óbito (5,5%). CONCLUSÃO: A inversão do fluxo arterial no sistema venoso do pé deve ser considerada para salvamento de extremidade com isquemia crítica sem leito arterial distal.

New insights into the molecular pathogenesis of pulmonary arterial hypertension: Relevance to novel therapeutic strategies

Haploinsufficiency of bone morphogenetic protein receptor-2 (BMPR2) underlies most cases of familial and almost one-half of the idiopathic forms of pulmonary arterial hypertension (PAH). The BMPR2 pathway has been implicated in inhibitory growth regulation of pulmonary artery smooth muscle cells (SMCs), whereas it mediates survival signalling in endothelial cells (ECs). Thus, loss-of-function mutations may contribute to the pathophysiology of PAH by two complementary mechanisms: first, through dysregulated SMC growth leading to medial hyperplasia of pulmonary arteries and arterioles; and, second, by increasing the susceptibility of pulmonary arteriolar ECs to injury and loss in response to various environmental triggers. This hypothesis may represent a ‘double jeopardy' for PAH because apoptosis of pulmonary vascular ECs, particularly at the level of precapillary arterioles, could lead directly to the degeneration of these fragile endothelial structures and loss of efficient perfusion of the distal alveolar capillary bed, while exaggerated SMC proliferation may result in dramatic arterial remodelling. Moreover, EC apoptosis has been suggested to create conditions that favour the emergence of abnormal, apoptosisresistant, hyperproliferative ECs, which may be the genesis of the characteristic plexiform lesions in PAH. This new paradigm suggests that novel strategies aimed at endothelial repair and regeneration may be uniquely effective for the treatment of PAH. The use of endothelial progenitor cells and angiogenic gene therapy, and the results of preclinical proof-of-principle experiments supporting the initiation of a first-in-man clinical trial are reviewed.

Abstract 414: Endothelial dysfunction of Epicardial Resistance Arteries in Pigs after Coronary Artery Implant of Paclitaxel-Eluting Stents

Background: Abnormal endothelium-dependent vasorelaxation of coronary arteries adjacent to drug-eluting stent (DES) implants has been reported and may be associated with late stent thrombosis. However, epicardial resistance vessel vasomotor function in the distal perfusion bed of DES has not been studied. We tested small vessel function 1 mo after coronary artery paclitaxel-eluting stent (PES) implant. Methods: Pigs (n=9) received overlapping bare metal stent (BMS) and PES as well as naïve vessels. One month later, myocardium distal to the stented region, as well as similar location in non-stented vessel (nSV) was harvested. Eighteen epicardial resistance arteries (lumen diameter ~ 250μm) were isolated under a dissecting microscope and mounted on a myograph apparatus. Vasoconstriction (KCl, PGF2α & ET-1), endothelial-dependent relaxation (EDdR) response to substance P (SP), and endothelial-independent relaxation (EDiR) to sodium nitroprosside (SNP) were measured. Results: Angiographic late lumen loss at 1-mo was less for PES than BMS (p=0.002). Epicardial resistance artery relaxation was attenuated in the perfusion distribution of PES, as maximal EDdR in response to SP was 56.0±7.0% compared to vessels isolated from the perfusion distribution of BMS (85.0±7.0%) and non-stented coronary segments (107±2.0%, P=0.034 vs. PES). Maximal EDiR in response to SNP, however, was similar among the groups (90.0±6.0%, PES; 98.0±2.0%, BMS; 123±5.0%, nSV; P=NS respectively). Similarly contraction to endothelin-1 was not affected by stent type (3.95±0.56%, PES; 3.07±0.65%, BMS; 3.01±0.36%, nSV; ratio of contraction ET-1/KCl; P=NS respectively). Conclusions: Epicardial resistance artery endothelial-dependent vasomotor dysfunction is present one month after overlapping coronary PES implant in swine. Derangement of microcirculatory vasomotor function may also be present with DES implant in humans and be associated with a spectrum of adverse clinical sequelae.

Differences in cardiac microcirculatory wave patterns between the proximal left mainstem and proximal right coronary artery

Despite having almost identical origins and similar perfusion pressures, the flow-velocity waveforms in the left and right coronary arteries are strikingly different. We hypothesized that pressure differences originating from the distal (microcirculatory) bed would account for the differences in the flow-velocity waveform. We used wave intensity analysis to separate and quantify proximal- and distal-originating pressures to study the differences in velocity waveforms. In 20 subjects with unobstructed coronary arteries, sensor-tipped intra-arterial wires were used to measure simultaneous pressure and Doppler velocity in the proximal left main stem (LMS) and proximal right coronary artery (RCA). Proximal- and distal-originating waves were separated using wave intensity analysis, and differences in waves were examined in relation to structural and anatomic differences between the two arteries. Diastolic flow velocity was lower in the RCA than in the LMS (35.1 +/- 21.4 vs. 56.4 +/- 32.5 cm/s, P < 0.002), and, consequently, the diastolic-to-systolic ratio of peak flow velocity in the RCA was significantly less than in the LMS (1.00 +/- 0.32 vs. 1.79 +/- 0.48, P < 0.001). This was due to a lower distal-originating suction wave (8.2 +/- 6.6 x 10(3) vs. 16.0 +/- 12.2 x 10(3) W.m(-2).s(-1), P < 0.01). The suction wave in the LMS correlated positively with left ventricular pressure (r = 0.6, P < 0.01) and in the RCA with estimated right ventricular systolic pressure (r = 0.7, P = 0.05) but not with the respective diameter in these arteries. In contrast to the LMS, where coronary flow velocity was predominantly diastolic, in the proximal RCA coronary flow velocity was similar in systole and diastole. This difference was due to a smaller distal-originating suction wave in the RCA, which can be explained by differences in elastance and pressure generated between right and left ventricles.

Bullet Embolism after Gunshot Injury: A Case Report

We describe a case of gunshot injury presenting with cardiac tamponade in which a dummy bullet advanced through the aorta and caused embolization in the right renal interlobar artery after passing above the sternoclavicular joint and penetrating into the aorta. Emergency surgery with cardiopulmonary bypass was performed to repair the cardiac tamponade and aortic injury. Postoperatively, a direct abdominal x ray revealed a bullet image, confirmed by an ultrasonography examination that demonstrated the presence of a metal object in the right renal pelvis. The bullet was considered to have reached the kidney via an arterial route and to cause embolization in the distal bed. The procedure was successful, and the patient was discharged on postoperative day 8. In gunshot injuries, if all entrance points are not paired with exit points, the possibility of an organ or extremity embolism caused by the presence of a bullet or shrapnel fragments in circulation should be borne in mind, although such occurrences are rare.

Intravascular Sarcoidosis Presenting as Pulmonary Vein Occlusion

It is well known that destruction of the distal capillary bed from extensive fibrosis and honeycombing in the setting of sarcoidosis may lead to pulmonary hypertension. However, we report an unusual manifestation of sarcoidosis where pulmonary hypertension resulted from granulomatous involvement of the pulmonary veins and venules. This presented as venous occlusion and intraluminal filling defects that simulated thrombus on chest computed tomography. To our knowledge, this is the first reported imaging case of such a presentation.

Native anomalous left coronary artery from the pulmonary artery in an adult: Evidence of impaired coronary flow reserve by rubidium-82 positron emission tomography quantification

A 52-year-old woman presented with a two-year history of decreased exercise tolerance and palpitations. An echocardiogram demonstrated a markedly dilated and tortuous right coronary artery. The left main coronary artery could not be visualized. Coronary angiography showed an anomalous left coronary artery from the pulmonary artery (Figure 1). Blood flow to the left coronary system was entirely dependent on collaterals emanating from the right coronary artery. For a portion of the collateralized blood, there was a retrograde (‘upstream’) flow in the left epicardial system, with subsequent drainage into the pulmonary artery (‘myocardial-pulmonary steal’). This created a left-to-right shunt with a calculated pulmonary to systemic blood flow ratio of 1.5. On rubidium-82 positron emission tomography scanning, there was no perfusion abnormality at rest (Figure 2). This may have been possible due to chronic, compensatory arteriolar vasodilation in the distal bed of the left epicardial tree. This mechanism permitted the myocardium to ‘compete’ with the low pressure ‘sink’ of the pulmonary artery, thus allowing for a portion of the collateralized flow to pursue an antegrade (‘downstream’) course toward the left coronary microcirculation. On stress imaging with dipyridamole, there was a large defect in the left anterior descending artery area. Regional myocardial blood flow quantification, using rubidium-82 net retention, showed a marked reduction in coronary flow reserve in the left anterior descending artery area compared with that of the right coronary artery (Figure 3). This impaired flow reserve may be explained by limitations in further vasodilation at the site of the collateral network and/or the arteriolar circulation in the distal bed of the left anterior descending artery system. This setup creates the potential for intermittent ischemic episodes during stress and may explain the risk of sudden death reported in this patient population. Figure 1 Selective injection of the right coronary artery (RCA) in the 30° right anterior oblique projection. In the early phase of injection, a markedly dilated and tortuous RCA is noted (A). In the late phase of the injection, the left anterior descending ... Figure 2 Short and vertical long axis views of standard single photon emission computed tomography imaging with rubidium-82. Markedly diminished perfusion is seen in the left anterior descending artery area during dipyridamole infusion (stress), with normalization ... Figure 3 Quantification method: Rest and stress rubidium-82 uptake plus stress/rest (flow reserve) polar maps. In the upper panel, calculated flows (in mL/g/min) are on the right of the colour bar. In the lower panel, each increment represents a degree of standard ...

River system discontinuities due to lateral inputs: generic styles and controls

AbstractIn alluvial river systems, lateral inputs of water and/or sediment at junctions or undercut hillsides can disrupt what would otherwise be smooth downstream trends in mainstream bed elevation, channel gradient, and bed grain size. Generic styles of mainstream response to lateral inputs are investigated using a one‐dimensional sediment routing model with multiple grain size fractions. Numerical experiments isolate the effects of three para‐meters: ratio of tributary to mainstream water flux (QR), ratio of tributary to mainstream bedload flux (FR), and ratio of tributary to mainstream bedload diameter (DR). The findings are not unduly sensitive to the choice of initial conditions or to approximations made in the model. The primary distinction is between junctions that aggrade, causing local profile convexity with interrupted downstream fining, and junctions that degrade. The immediate effects of aggradation extend further upstream than downstream, whereas degradation is much more subdued and has no upstream impact. Aggradation is typical of coarse inputs (DR &gt; 2), and degradation of fine inputs (DR &lt; 1), but very high ratios of QR to FR also promote degradation. Both aggrading and degrading junctions can lead to a change in mainstream bed grain size well below the junction, with higher ratios of QR to FR producing a coarser distal bed. The effect of a tributary reflects the interplay between additional bed load and additional discharge to transport it. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Resultados tardios das reconstruções arteriais dos membros inferiores com a utilização de veias portadoras de dilatações varicosas revestidas seletivamente com segmentos protéticos

OBJETIVO: Responder as seguintes questões: 1) o revestimento protético deve ser precedido de uma redução da ectasia? 2) as zonas revestidas apresentam um risco de hiperplasia ou estenose? 3) as zonas não revestidas possuem um risco de dilatação e ruptura? MÉTODOS: Doze pacientes (10 homens e duas mulheres), com idades entre 33 e 77 anos (idade mediana = 68), foram submetidos a pontes em conseqüência de arterite (n = 7), aneurisma poplíteo (n = 4) ou ruptura de prótese (n = 1). As pontes foram fêmoro-poplíteas (n = 8), fêmoro-infra poplíteas (n = 3) e poplíteo-poplítea (n = 1). A safena utilizada foi de forma reversa em nove casos e ex situ devalvuladas em três casos. Os revestimentos foram aplicados em número de um (n = 2), dois (n = 3), três (n = 6) e quatro (n = 1). Todos, exceto um, foram de PTFE. RESULTADOS: Duas pontes ocluíram, uma precocemente por déficit de leito distal e outra 4 anos após a operação. As outras 10 pontes permaneceram pérvias durante o acompanhamento, que variou entre 1 e 11 anos (mediana = 4 anos). Metade dos casos apresentou uma deterioração progressiva do leito distal. No último controle, duas pontes permaneceram pérvias, a despeito de um leito distal desértico. CONCLUSÃO: Os resultados desta série apresentam-se notadamente superiores aos das pontes protéicas descritas na literatura. O revestimento é efetuado facilmente com uma prótese curta de PTFE de parede fina. É inútil reduzir as dilatações antes do revestimento por sutura ou ressecção - anastomose. As zonas situadas sobre a bainha de PTFE não evoluem para estenoses. As zonas intermediárias dilatam-se por vezes moderadamente e sem risco de ruptura.

Catheter-based interventional palliation for hypoplastic left heart syndrome

Catheter-based interventional palliation of infants with hypoplastic left heart syndrome (HLHS) has been successfully used to stabilize infants awaiting orthotopic heart transplantation. The three critical palliative requirements for HLHS are ductal patentcy, left heart decompression, and the regulation of pulmonary flow. We reviewed our experience in 40 infants with ductal stenting, and 17 of these 40 infants underwent placement of internal pulmonary artery bands. The infants ranged in age from 2 days to 7 months and from 2.1 to 6.6 kg in weight. There was one procedure-related death after balloon septostomy. The duration of palliation was from 3 days to 1 year. Late survival was 75% with long-term palliation or transplantation. Experience and anatomy of the RV outflow tract/ductus arteriosus was related to technical complications. Infants with mesoversion (12%) were more likely to have procedural and late complications (65%). Internal pulmonary artery bands provide predictable and effective protection of the distal pulmonary artery bed. Pulmonary artery reconstruction was not required, and there were no late pulmonary artery stenoses. We conclude that interventional catheter-based palliation of HLHS has been proven in principle, and further gains in experience and technology will likely make this desirable in the majority of infants with hypoplastic left heart syndrome.

295 Ten years follow-up after myocardial revascularisation for end-stage heart failure and poor distal coronary bed

295 Ten years follow-up after myocardial revascularisation for end-stage heart failure and poor distal coronary bed

If there's smoke, is there fire?

As we read through the medical literature, we are always looking for the “hottest” new advances (jumping right into the smoke/fire analogy thing): basic science that gives us new mechanistic insights, clinical trials that confirm or reject our so-called insights, major new diagnostic and therapeutic options, and breakthrough technology. We are a lot like forest rangers, sitting up on a platform, way above the trees, looking out over the forest, and seeing something in the distance that looks like smoke. Then we have to decide if what we are seeing is really smoke coming from some forest-threatening fire, or if it is just fog in the trees. See p 1476 In the present issue of Circulation , Payne et al present a study1 showing that the addition of clopidogrel to aspirin significantly reduced the incidence of transcranial Doppler (TCD)–detected microemboli in patients after carotid endarterectomy (CEA). At face value, this makes intuitive sense. Given the importance of platelets and platelet emboli in postprocedural distal bed vascular injury (a lesson well learned in the coronary circulation), it seems logical to extend this to try to improve the outcomes of vascular manipulations in the cerebrovascular circulation. “Manipulation” may be a bit of an understatement when applied to a surgical procedure such as CEA, but the fact remains that there is room for improvement. Given the considerable benefits of aspirin plus thienopyridines in the world of percutaneous intervention in STent Antithrombotic Regimen Study (STARS)2 and the more recent Clopidogrel for Reduction of Events During Observation (CREDO)3 and Intracoronary Stenting and Antithrombotic Regimen–Rapid Early Action for Coronary Treatment (ISAR-REACT)4 studies, and in acute coronary syndromes in Clopidogrel in Unstable angina to prevent Recurrent ischemic Events (CURE),5 does this look to be a promising strategy for CEA? The study by …

Expression of TGF-beta in region of bone defect repaired by collagen/nano-beta-tricalcium phosphate composite artificial bone.

The distribution and function of transforming growth factor-beta (TGF-beta) in the region of bone defect repaired by collagen/nano-beta-tricalcium phosphate composite artificial bone (Co/N-TCP) and the ability of Co/N-TCP recruiting osteoblasts to precipitate the repair of bone defect were investigated. Twenty-four domestic rabbits were operated on bilateral cranial bone to create an experimental bone defect of 8.0 mm in diameter through the whole bone. On the left, Co/N-TCP was implanted as experimental group, but on the right, Co/TCP was implanted as control group. At 2nd, 4th, 8th, 12th week after operation, all animals were sacrificed and the implanted materials with surrounding bone were taken out. Immunohistochemical staining was performed for TGF-beta assay by avidin-biotin complex method (SABC). Simultaneously, TGF-beta was quantitatively analyzed by HPIAS-1000 imaging analysis system. The immunohistochemical staining for TGF-beta revealed that osteoblasts and immature osteocytes highly expressed TGF-beta. Diffused TGF-beta positive staining particles appeared in the mesenchymal and fibrous-tissue. There was no significant difference in the TGF-beta positive staining between two groups in the medial region to original osseous beds at different time points (P > 0.05). However, in distal original osseous bed of the defected region, the positive expression of TGF-beta in the Co/N-TCP group was significantly stronger than in the control group (P < 0.05 or 0.01). The Co/N-TCP has good bioactivities and ability of stimulating and conducting TGF-beta to aggregate and precipitate the healing of bone defect.