冠状动脉旁路移植术桡动脉桥家兔模型的建立

目的建立一个能模拟冠状动脉旁路移植术桡动脉桥情况的模型。方法50只新西兰兔,股动脉与颈总动脉行端侧吻合,两吻合口之间的颈总动脉予以结扎。术后1、3、7、14、56d分别取完整动脉桥,进行肉眼观察,HE染色观察病理变化,弹力纤维染色,计算机测算血管内膜厚度、新生内膜中膜比指数;电镜观察血管内皮细胞变化。结果50只兔成功建立动脉桥,无手术及围手术期死亡,桥血管总通畅率为86％,对通畅的桥血管作形态学观测发现血管移植后7d起至56d内膜增厚有统计学差异。结论本动物模型可以较好地模拟冠状动脉旁路移植术桡动脉桥的情况。     

双源CT 冠状动脉血管成像诊断心肌桥的价值探讨

目的：研究双源CT 冠状动脉血管成像诊断心肌桥的临床价值。方法：选择260 例具有典型心前区不适的患者进行双源CT 冠脉血管成像检查,观察其发生部位,测量其长度和深度并进行分析。结果：260 例受检患者中,62例共70 段存在心肌桥,检出率 达20.76%,高于文献报道的检出率18.2%。所有心肌桥均发生于左前降支,其中近段17 段(24.4%),中段43 段(61.4%),远段10 段 (14.2%)。心肌桥平均长度为15.8± 6.4mm,深度为1.4± 0.85mm。结论：双源CT 冠状动脉血管成像因其便捷无创,不受心率严格 限制且价格低廉可作为心肌桥筛查的理想检查手段。     

双源CT冠状动脉血管成像诊断心肌桥的价值探讨

目的：研究双源CT冠状动脉血管成像诊断心肌桥的临床价值。方法：选择260例具有典型心前区不适的患者进行双源CT冠脉血管成像检查,观察其发生部位,测量其长度和深度并进行分析。结果：260例受检患者中,62例共70段存在心肌桥,检出率达20.76%,高于文献报道的检出率18.2%。所有心肌桥均发生于左前降支,其中近段17段（24.4%）,中段43段（61.4%）,远段10段（14.2%）。心肌桥平均长度为15.8±6.4mm,深度为1.4±0.85mm。结论：双源CT冠状动脉血管成像因其便捷无创,不受心率严格限制且价格低廉可作为心肌桥筛查的理想检查手段。     

A very rare image in cardiology: posterolateral artery myocardial bridge

Muscle overlying of an epicardial coronary artery is termed a myocardial bridge. The frequency of myocardial bridging reported in angiographic studies varies from 0.5 to 16%.1 Myocardial bridging is usually confined to the left anterior descending coronary artery. A myocardial bridge of the branches of the right coronary artery is very rare.     

Stent implantation at the site of the myocardial bridge after myocardial infarction. Long-term results

Although myocardial bridge is asymptomatic in most patients, it can lead to myocardial ischemia, myocardial infarction, cardiac arrhythmias, and sudden death. The authors report the case of a symptomatic myocardial bridge treated by classical stenting of the mid left anterior descending artery. The outcome was good. A control coronary angiography performed 36 months later showed no significant restenosis. No recurrence of angina during five years follow-up was observed.     

Some observations on the posterior and lateral bridge of the atlas

Six hundred and seventy-two atlas vertebrae of 6 population groups were examined for the presence of a posterior and/or lateral bridge. Of these, 174 (25.9%) presented with partial posterior bridge formation and 53 (7.9%) with a complete bridge. Twenty-six (3.8%) showed some form of lateral bridging. Although controversy exists as to the origin of atlas bridging, the findings of the present study show that aging could be a factor predisposing to complete bridge formation. The clinical significance of bridge formation is discussed with reference to their possible effect on normal vertebral artery function, particularly in rotation.     

选择性冠状静脉动脉化搭桥术中不同移植物的应用疗效比较

目的:对比选择性冠状静脉动脉化(SCVBG)搭桥治疗弥漫性右冠状动脉狭窄病变中选择乳内动脉和大隐静脉作为桥血管的治疗效果。方法:选择2008年10月到2014年10月在我院行SCVBG搭桥的84例患者资料,其中选择大隐静脉作为桥血管进行冠状静脉动脉化搭桥患者46例(大隐静脉桥组),选择乳内动脉作为桥血管进行冠状静脉动脉化搭桥患者38例(乳内动脉桥组)。随访记录两组患者的生存情况、近期复查超声心动图、冠状动脉CTA及心绞痛复发率。结果:乳内动脉桥组患者总生存率(100%)明显高于大隐静脉桥组(82.6%)(P0.05)。乳内动脉桥组患者桥血管和心中静脉通畅率(100%)明显大于大隐静脉桥组(54.35%)(P0.05)。两组患者左心室射血分数(LVEF)较治疗前明显增加,左心室舒张期末内径(LVEDD)较治疗前明显减小(P0.05)。治疗后,乳内动脉桥组患者心绞痛复发率明显小于大隐静脉桥组(P0.05)。结论:SCVBG搭桥治疗弥漫性右冠状动脉狭窄病变中,选择乳内动脉桥效果优于大隐静脉桥,能明显提高桥血管和心中静脉通畅率,降低心绞痛复发率。     

A tissue-expanding vermilion myocutaneous flap for lip repair

An approach to lip reconstruction is described utilizing a myocutaneous vermilion flap based on the inferior labial artery. The inherent elasticity of the lip is used to great advantage by stretching the freed vermilion flap to bridge a loss of about one-half the lower lip. This vermilion flap may be worthy of consideration when reconstructing lip defects resulting from trauma (e.g., electric burns), tumor resections, and other congenital anomalies.     

Relationship Between Myocardial Bridging and Coronary Arteriosclerosis

The objective of the study was to explore the prevalence and characteristics of myocardial bridging in patients who underwent coronary angiography and to also evaluate the correlation between bridged coronary segments and atherosclerosis. For this purpose, clinical materials of 1,500 patients who had received coronary angiography were retrospectively analyzed. The location and length of the myocardial bridge were recorded as well as the extent and location of coronary artery stenosis was described. Segments proximal and distal to the bridging were evaluated for coronary arteriosclerosis as were the remaining coronary segments. We found that myocardial bridging was present in 179 (11.9 %) patients. Bridges were frequently (84.9 %) localized in the mid-distal segment of the left anterior descending (LAD) artery. Myocardial bridging was not considered a significant risk factor for coronary atherosclerosis (odds ratio 0.58) compared with traditional cardiovascular risk factors. The incidence of coronary arteriosclerosis in the distal segments was significantly less affected than the proximal segments (P < 0.01). It was, therefore, concluded that myocardial bridging frequently localized in the mid-distal segment of the LAD artery. The presence of myocardial bridging promotes proximal atherosclerosis but it is not an additional risk factor for coronary atherosclerosis.     

So-called muscular "bridges" and their interrelationship with blood vessels]

Fifty hearts of corpses of humans of different age groups were studied by means of macro-microscopical anatomical dissection of muscle fibres and cardiac blood vessels. The muscle bridges were found over the coronary arteries in all preparations of the heart. They were most frequently met on the anterior interventricular branch of the left coronary artery. The topography of muscle bridges is described and the miocardium muscle bundles participating in their formation are revealed. The character of the course of fibres in the muscle bridge is related to the course of the fibres of the muscle bundle forming it.     

Computer modeling of fluid dynamics related to a myocardial bridge in a coronary artery

Fluid mechanics associated with blood flows induced by the so-called myocardial bridge (MB) has been studied systematically using a computational fluid dynamic modeling of the Newtonian, incompressible, two-dimensional, unsteady flow in a channel with a time-dependently flushing in/out indentation. During each cycle, a train of vortex wave flow was observed downstream of the phasic stenosis and both upper and lower walls suffer severely from consistently high, oscillating wall shear stresses (WSS). Extensive studies were conducted on the influence of the Reynolds number, the geometry and the Strouhal number of the MB movement on the nature of the vortex flow and the time-dependent wall shear stress distribution. Special attention was drawn to the relationship between the vortex wave and the pressure distribution. It was found that the pressure gradient changed markedly during one cycle, which was apparently dominated by the dynamics of the indentation. A steep, adverse pressure gradient was observed when the indentation was flushing out, which corresponded to the existence of the most developing vortices. It implies the possibility that the MB in a coronary artery can produce an extremely low pressure region immediately downstream of the phasic stenosis, where elastic choking or collapse of the coronary artery might occur.     

Cytokinetic activities in a human cell line: the midbody and intercellular bridge

The midbody and intercellular bridge of D-98S cells were studied by time lapse cinemicrography. Before separation interconnected daughter cells tended to move in opposition to each other, maintaining tension across the bridge and, in some cases, lengthening the bridge. Cell separation was preceded by a reduction in width of the bridge, on one or both sides of the midbody, to a cytoplasmic strand less than 0-5 μ wide, which was then stretched and broken by movements of the daughter cells, completing cytokinesis. Wave-like movements were observed to pass along longer intercellular bridges from the midbody to the daughter cells. This activity was judged to be involved with the retraction of cytoplasm from the bridge into the daughter cells. Wave activity was disrupted by the drug cytochalasin B.     

New basicrania of Paleocene-Eocene Ignacius: re-evaluation of the Plesiadapiform-Dermopteran link

Plesiadapiformes has long been considered to be an archaic group of Primates. Discovery of a paromomyid plesiadapiform skull and independent analysis of referred postcrania have led investigators to conclude that Plesiadapiformes shares a closer relationship to extant flying lemurs (Dermoptera) than to Primates (= Euprimates of Hoffstetter [1977] Bull Mem Soc Anthropol Paris Ser 13 4:327-346). Despite challenges to this interpretation, the plesiadapiform-dermopteran relationship has gained currency in recent years. Here we show that newly discovered crania of Ignacius graybullianus, preserving previously undocumented portions of the ear, are more similar to primates than to dermopterans. New specimens confirm that paromomyids lacked the petrosal bulla of primates. However, these new specimens also demonstrate that paromomyids likely had: 1) a small promontorial branch of the internal carotid artery; 2) a lateral route for the internal carotid nerves crossing the promontorium; and 3) a ring-like ectotympanic with an annular bridge. This pattern is similar to primitive primates and fundamentally different from dermopterans, which have: 1) no internal carotid artery; 2) internal carotid nerves that take a more medial route; and 3) no annular bridge. Recognition of some primate-like traits, documented here by new evidence, indicates that Paromomyidae is likely to be more closely related to other Paleogene Plesiadapiformes and Eocene Primates than to extant Dermoptera. In view of these findings, a link between paromomyids and extant dermopterans ("Eudermoptera") is not convincingly supported by a single characteristic of the basicranium.     

Site-directed mutagenesis of disulfide bridges in Aspergillus niger NRRL 3135 phytase (PhyA), their expression in Pichia pastoris and catalytic characterization

Earlier studies have established the importance of five disulfide bridges (DBs) in Aspergillus niger phytase. In this study, the relative importance of each of the individual disulfide bridge is determined by its removal by site-directed mutagenesis of specific cysteines in the cloned A. niger phyA gene. Individually, these mutant phytases were expressed in a Pichia expression system and their product purified and characterized. The removal of disulfide bridge 2 yielded a mutant phytase with a complete loss of catalytic activity. The other disulfide mutants displayed a broad array of altered catalytic properties including a lower optimum temperature from 58°C to 53°C for bridge number 1, 37°C for bridge number 3 and 4, and 42°C for bridge number 5. The pH versus activity profile was also modified in the DB mutants. The pH profile of the wild-type phytase was modified by the DB mutations. In bridge number 1, 3, and 4, the second peak at pH 2.5 was abolished, and in bridge number 5, the peak at pH 5.0 was abolished completely leaving only the pH 2.5. While the K _m was not affected drastically, the turnover number was lowered significantly in bridge number 3, 4, and 5.     

Avulsion injuries of the thumb

Avulsion amputations of the thumb are generally thought to have a worse prognosis after replantation than other amputations. We report the results of 17 thumbs that had an avulsion amputation and were replanted. Fourteen of the 17 survived (82 percent). Our experience indicated that the survival rate was improved by restoring continuity of at least two veins and two arteries, using a Y-shaped vein graft and the princeps pollicis artery for the source of arterial circulation. Nerve grafts were used to bridge defects in avulsed digital nerves. When possible, avulsed tendons were reattached to their muscle. Key pinch strength was 60 percent of normal, and grip strength was always less than that of the normal hand. The age of the patients and the cold ischemia time had no significant effect on either survival or function of the replanted thumb. When excellent venous backflow occurred immediately after the vessel repair and continued for at least 20 minutes, the thumb always survived without complications.     

A new flap design: neural-island flap

This report introduces the "neural-island flap" concept, which represents a consistent and reliable skin flap design supplied only by the intrinsic vasculature of a cutaneous nerve. In this study, the lateral femoral cutaneous nerve was selected as the pedicle of the neural-island flap, and a standard skin flap, which is the territory of the accompanying vessels (i.e., iliac branches of the iliolumbar artery and vein), was elevated on the lower dorsal region of the rats. In a total of 92 Wistar rats, three experiments were performed. In part I (n = 24), the vascular anatomy of the lateral femoral cutaneous nerve was established by the methods of dissection, microangiography, nerve mapping, perfusion with colored latex and India ink, and histologic analysis. In part II (n = 46), the role of the cutaneous nerve in supporting an acutely elevated skin flap was explored by creating five flap groups as follows: group 1, conventional flap (artery, vein, and nerve intact); group 2, neural island flap (only the nerve intact); group 3, neurocutaneous flap (vein and nerve intact); group 4, denervated flap (artery and vein intact); and group 5, skin graft. In part III (n = 22), the role of a preliminary surgical delay procedure to augment the survival of the neural island flap was investigated. Results of the anatomic studies indicated a consistent perineural vasculature by the accompanying iliolumbar artery. Skin flaps survived totally in groups where the artery and vein were intact, whereas mean survival rates for the neural island flap and the neurocutaneous flap were 38.2 +/- 3.1 percent and 44.5 +/- 3.8 percent, respectively (p > 0.05). Results of part III of the experiment demonstrated a significantly higher survival for the delayed neural island flap (94.5 +/- 5.5 percent) compared with the acutely elevated neural island flap (p < 0.05). The perineural and intraneural vessels were found to be greatly dilated after a delay procedure, demonstrated by direct observation, microangiography, histologic analysis, dye injection study, and scanning electron microscopy. On the basis of this promising series of experiments, a clinical technique was developed using the sural neural-island flap. The flap was used to reconstruct lower extremity defects in four cases. A delay procedure was accomplished in the first stage by elevating a fasciocutaneous flap from the midcalf region based on a posterior skin bridge and the sural nerve. After a 2-week delay period, a sural neural-island flap was created based on the nerve and transposed to the defect. Flap survival was complete in all cases, with a satisfactory result. The authors conclude that this report proves for the first time that a robust and reliable skin flap can be created pedicled only by the intrinsic vasculature of a cutaneous nerve, after a proper surgical delay. The so-created neural-island flap design offers two novel advantages: (1) a very narrow pedicle and (2) a pedicle without any restriction to a specific pivot point, in addition to the previously described unique advantages of preservation of a major artery and avoidance of microvascular anastomoses.     

Conformation-based design of two cyclic physalaemin analogues

Two new cyclic analogues of physalaemin were designed on the basis of the conformation found in DMSO solution. Glp-Ala-cyclo(-Asp-Pro-Asn-Lys-)-Phe-Tyr-Gly-Leu-Met-NH2 (1) was synthesized by cyclization of physalaemin. In 2 the Asp residue was replaced by Glu. The linear analogue of 2 was synthesized by the solid phase method and subsequently cyclized. Two-dimensional nmr methods were employed to assign the proton and carbon resonances. Proton-proton distances were extracted from rotating frame nuclear Overhauser effect spectra and used as restraints in the molecular dynamics calculations. Analogue 1 was found to have a similar conformation as physalaemin, whereas 2 did not form intramolecular hydrogen bonds. The pharmacological evaluation revealed that both peptides have similar potencies as physalaemin in the dog carotid artery (NK-1 receptor). Therefore, the charged side chains of physalaemin appear not essential for NK-1 activation. However, the other tachykinin receptors show good sensitivity to the cyclic peptides. It is concluded that the replacement of a salt bridge by an amide bond connecting the side chains of natural residues might provide useful information about the biological significance of some charged side chains of neurokinins.     

ACS,myocardial bridging,Tako-tsubo syndrome and mitral regurgitation

Isolated systolic compression of the mid portion of the left anterior descending artery (LAD) by a bridge of overlying cardiac muscle is an infrequent but well-recognised angiographic anomaly that is often considered harmless. The long-term prognosis appears to be excellent, but occasional reports of patients with angina pectoris, myocardial infarction and sudden death indicate that this is not always true. The prevalence of the anomaly in the normal population is unknown, but the incidence is low and ischaemic events are rare.Tako-tsubo-like left ventricular dysfunction syndrome (TTS) is characterised by ischaemia, anterior ST-segment elevation, no significant coronary artery disease and reversible ampulla-like left ventricular ballooning in postmenopausal females after emotional or physical stress. Dynamic left ventricular outflow tract (LVOT) obstruction is a rare but potentially fatal complication of acute anterior wall infarction.We present a patient with an acute coronary syndrome (ACS) with ST-segment elevation in the anterior leads, transient TTS and transient LVOT obstruction with systolic anterior motion (SAM) of the mitral valve and severe mitral regurgitation. This is the first report of myocardial bridging associated with TTS, and the first report of TTS associated with dynamic LVOT obstruction with SAM and mitral regurgitation.     

Conformationally restricted TRH analogues: constraining the pyroglutamate region.

A modified synthetic route has been developed so that the steric size of constraints added to the pyroglutamate region of TRH (pGluHisProNH(2)) can be varied. Both an analogue with a smaller ethylene bridge and a larger, more flexible propane bridge in this region have been synthesized. These analogues were synthesized in order to probe why the initial incorporation of an ethane bridge into this region of the molecule had led to an analogue with a binding constant and potency three times lower than that of an directly analogous unconstrained analogue. The data for both analogues indicated that the fall off in activity caused by the ethane bridge in the initial analogue was not caused by the size of the bridge.     

Preliminary studies on the optimum shape of dental bridges

Several pre-existing anterior and posterior dental bridge models using Finite elements and the new ceramic material In-Ceram have been developed. The mechanical behaviour of these models has been compared with optimised profiles obtained from a newly developed evolutionary algorithm known as Evolutionary Structural Optimisation (ESO). The results show that the mechanical behaviour of the bridges was mainly restricted by the properties of the porcelain veneer and the design of the bridges themselves. For the case of the anterior bridge, it was found that there existed a specific thickness of veneer that minimised the maximum principal stress. This was related to peak stresses that occurred at the bridge surface. Peak stresses also occurred in the material interface between the In-Ceram and the veneer. These extreme stresses were attributed to the notch size and shape. For the case of the posterior bridge, it was concluded that the shape of the bottom of the Pontic tooth is crucial in reducing the magnitude of the maximum principal tensile stress. The ESO process produced bridge designs which have uniformly stressed bridge surfaces, and which also have significantly lower maximum principal tensile stresses compared to the pre-existing designs (up to 44%).