Treatment of type B aortic dissection: endoluminal repair or conventional medical therapy?

OBJECTIVE: To evaluate the mid-term results of endovascular stent-grafting for type B aortic dissection, in comparison with those of standard medical therapy in uncomplicated cases. METHODS: Between January 1999 and 2004, among 56 patients (mean age 59.5+/-11.5 years) with type B aortic dissection, hypotensive medical therapy was the only treatment in 28 uncomplicated cases, (group A), while stent-graft implantation was performed in 28 patients with uncontrolled hypertension, persistent pain or evidence of dissection progression or complication (group B). In 14 cases (50%) the procedure was performed in an acute setting. Stent-grafting procedures were monitored with intraoperative trans-esophageal echocardiography and cine-angiography. CT scan and trans-esophageal echocardiography were performed before hospital discharge, at 6 and 12 months and then yearly. RESULTS: Follow-up (range 1-61 months, average 18.1+/-16.9 months) was 100% complete. In-hospital mortality was 10.7% (three patients, all belonging to Group B; P=0.24). No spinal cord injuries were observed. Early endoleak occurred in one patient (3.5%). Mid-term mortality was lower in Group B, although the difference was not significant (10.7 versus 14.3% in Group A, P=0.71). Follow-up CT scans evidenced complete thrombosis of the false lumen in 75% cases in Group B, 10.7% in Group A (P=0.0001), and an aneurismal dilatation of the descending aorta in 3.5% cases in Group B, 28.5% in Group A (P=0.02). CONCLUSIONS: Although with still considerable early mortality, endovascular stent-graft implantation is an effective option for the treatment of complicated type B aortic dissection. Endovascular treatment achieved a better mid-term fate of the descending thoracic aorta than medical therapy alone, even in patients with worse preoperative conditions.     

术中射频消融后病灶刮除治疗脊柱转移瘤

目的:探讨术中射频消融(RFA)后再行病灶刮除术治疗脊柱转移瘤的可行性及疗效.方法:2004年～2006年,对11例脊柱转移瘤患者术中实施RFA后再行病灶刮除术,将FRA前后病灶标本进行光镜和电镜病理检查,随访患者疼痛缓解情况及肿瘤复发情况.结果:术中未出现脊髓和神经根损伤,RFA后瘤组织固缩,刮除顺利,出血量350～3800ml,平均1024.5ml.全部病例得到6个月以上随访,平均9.8个月,全部患者生存期超过6个月,VAS评分术前平均5.8分,术后6个月时平均1.9分.1例出现局部肿瘤复发.RFA前的标本光、电镜检查均未见肿瘤组织坏死.RFA后光镜检查3例无明显坏死,9例肿瘤细胞完全坏死:电镜检查10例肿瘤细胞完全坏死,1例肿瘤细胞部分坏死,1例无明显坏死.结论:术中RFA后再行病灶刮除治疗脊柱转移瘤安全可行,有利于肿瘤的刮除,减少局部复发的风险.     

Copper,Zinc and Lead Enrichments in Sediments from Guacanayabo Gulf,Cuba, and Its Bioaccumulation in Oysters,Crassostrea rhizophorae

Levels of iron, copper, zinc and lead were determined in sediments and soft tissue of the oyster Crassostrea rhizophorae collected from Guacanayabo Gulf, Cuba. Metal-to-Iron ratio in sediments shows an average enrichment for Cu (5,1), Pb (11,7) and Zn (1,3) in the last 20 years. Metal concentrations found in soft tissue of C. rhizophorae are site dependent. The average biota-sediment accumulation factors (BSAFs) obtained for Fe, Cu and Pb are less than unity in all cases, indicating that only a little fraction of Cu and Pb in the sediments is bioavailable, independently of their enrichments. Zinc has an average BSAF value of 2.4 and may represent a serious impact in the area. The concentrations of zinc and copper in some of the oysters are above typical public health recommended limits.     

Replacement of the Descending Thoracic Aorta for Massive Aneurysm in Neonatal Marfan Syndrome

We describe a patient with neonatal Marfan syndrome presenting with massive ascending and descending thoracic aortic aneurysm. Because of rapidly progressive respiratory distress due to tracheobronchial compression, emergency replacement of the descending thoracic aorta with a 12-mm PTFE vascular prosthesis was undertaken at 1 month of age. The postoperative course was complicated by bilateral tension pneumothorax contributing to irreversible respiratory failure. The unique clinico-pathological features and the relevant surgical implications of the case are discussed. (J Card Surg 1994;9:109–114)     

Myocardial protection in adult cardiac surgery: current options and future challenges

Current techniques of myocardial protection are evolving with the use of less conventional modalities of cardioplegia and have reduced the morbidity and mortality of cardiac operations. Blood cardioplegic solutions appear superior to cold cardioplegia in terms of myocardial protection and adjuncts as glutamate/aspartate enhancement, antioxidant supplementation, nitric oxide donors and maintenance of calcium homeostasis seem effective. In the near future, further experimental and clinical investigations about pharmacological preconditioning, sodium–hydrogen exchangers inhibition and gene therapy need to be addressed to well define their potential role in the improvement of current techniques of myocardial protection that are suboptimal in high-risk clinical settings.     

Antisense knockdown of the Shaker-like Kv1.1 gene abolishes the central stimulatory effects of amphetamines in mice and rats.

Amphetamine (AMPH) is an indirect sympathomimetic compound classified as a substrate-type releaser that distinguishes it from other stimulants that act as uptake 1 blockers, such as cocaine (COC). In mammals, AMPH elicits central stimulation, hypermotility, anorexia, analgesia and analeptic activity, mainly through the increase of extracellular brain dopamine (DA). The inversion of vesicular transporters and/or intravesicular alkalinization is assumed to have a role in AMPH-induced exocytosis. However, the action mechanism of this compound has not yet been completely clarified. Recent evidence on the action of AMPHs indicates potassium channel-blocking properties in peripheral tissues. We investigated the possible involvement of a Shaker-like Kv1.1 channel subtype in the central effects of AMPH, using an antisense oligodeoxyribonucleotide (aODN) that specifically and reversibly inhibits the expression of these channels in the brain. The effect of aODN pretreatments was studied by evaluating the modification of behavioral effects induced in mice through the intracerebroventricular administration of AMPH, COC, or other compounds. The aODN in mice almost completely blocked the stimulatory effects of AMPH and other releasers but was ineffective in reducing the central activity of COC. In aODN-pretreated rats a strong reduction of the AMPH, but not of the COC-stimulated DA efflux from nucleus accumbens was observed. Our results suggest that the stimulant effects of AMPH and chemically related compounds, but not COC, require the presence of functionally active Kv1.1 channels in the brain.     

Early reconstruction of the abdominal wall in giant omphalocele.

Omphalocele is the most common congenital defect of the abdominal wall. Mortality rate is between 20 and 70% and early closure of the abdominal wall, within 10 days of life, is vital to the successful outcome of the surgical treatment. The authors describe the use of two bipedicled flaps of abdominal skin to correct the defect of the midline as soon as the reduction of all viscera has been accomplished.     

Effects of long-term acetyl-L-carnitine administration in rats--II: Protection against the disrupting effect of stress on the acquisition of appetitive behavior.

Long-term acetyl-L-carnitine (ALCAR) administration prevents the development of escape deficit produced by acute exposure to unavoidable stress. However, it does not revert the escape deficit sustained by chronic stress exposure. Rats exposed to chronic stress show a low dopamine (DA) output in the nucleus accumbens shell (NAcS) and do not acquire an appetitive behavior sustained by the earning of vanilla sugar (VS) made contingent on the choice of one of the two divergent arms of a Y-maze (VS-sustained appetitive behavior, VAB), while control rats consistently do. The present study shows that ALCAR treatment in rats exposed to a 7-day stress protocol prevented a decrease in DA output in the NAcS and medial prefrontal cortex (mPFC) of rats, and that it strengthened the DA response to VS consummation in the same two areas. Moreover, rats treated with long-term ALCAR or exposed to chronic stress while treated with ALCAR acquired VAB as efficiently as control rats. Moreover, VAB acquisition in stressed rats treated with ALCAR coincided with the reversal of the deficits in escape and in dopaminergic transmission in the NAcS. Thus, repeated ALCAR treatment preserved the DA response to VS in chronically stressed rats and this effect appeared to be predictive of the rat's competence to acquire VAB.     

β-N-Acetylhexosaminadases in human cerebrospinal fluid and serum of patients with multiple sclerosis

β-N-Acetylhexosaminidase activity and isoenzyme have been investigated in normal human cerebrospinal fluid and that of patients with multiple sclerosis. β-N-acetylhexosaminidase activity in normal cerebrospinal fluids has been resolved into five components. The major component was in a form that eluted from DEAE cellulose at the same salt concentration as hexosaminidase As, the isoenzyme previously identified in human serum. Cerebrospinal fluid from patients exhibited a different isoenzyme profile, showing a remarkable increase in a form having a pI which was more acidic than that of As. These changes have a potential use in the diagnosis and further biochemical characterization of multiple sclerosis.     

MR findings in pituitary haemosiderosis

A girl with Diamond-Blackfan syndrome and hypopituitarism was suspected of having pituitary haemosiderosis because of the clinical picture and the long history of blood transfusions. On T1-weighted MR images the pituitary exhibited a markedly hypointense anterior lobe (mimicking the empty sella), suggesting iron deposition, while on T2W MRI the low signal of the pituitary was surrounded by the high signal of the CSF. MR may be considered the examination of choice for detecting iron overload in the pituitary. Received: 10 November 1997 Accepted: 21 November 1997