Hybrid procedures for acute limb ischemia.

The most efficient treatment for acute arterial embolism is operative embolectomy using Fogarty's balloon catheter, especially if a single large artery is involved. Unfortunately, although the early surgical success of arterial thromboembolectomy often seems acceptable, the early clinical outcome still remains unsatisfactory. This may be related to the incomplete restoration of perfusion (i.e., residual thrombus in distal vessels not reached by the balloon catheter thromboembolectomy), propagation of residual thrombi or presence of underlying steno-occlusive lesions. In such a situation a meticulous intraoperative assessment of the adequacy of clot removal is decisive. Residual thrombus, chronic atherosclerotic disease and even vessel injuries secondary to balloon catheter passage can be corrected by endovascular techniques (hybrid procedures). The combination of surgical and endovascular options may overcome the limitations that characterize the traditional approach, and it is likely that in the future many treatments will be a mix of techniques that can be performed by vascular surgeons in the operating room or in a dedicated endovascular suite. This review article summarizes the hybrid treatment options for acute arterial occlusion caused by either embolism or local thrombosis.

An unusual late complication after SFA stenting: the artery rupture.

Peripheral artery rupture as a late complication of an endovascular stenting, due to the protrusion of a stent, has never been described in the literature in thigh arteries. Here we describe two anecdotic cases of artery rupture after superficial femoral artery (SFA) stenting. In both cases the endovascular procedure was performed as a reintervention at 2 and 27 months after a failed surgical or hybrid procedure for limb revascularization. The stent had been delivered in the first part of the SFA and the rupture occurred at the junction between the common femoral artery and SFA, which is one of the most flexible parts of the femoral artery. The cause of rupture was probably caused by an ulcer of the stent against the artery wall concomitant with a status of local or systemic infection. A huge pseudoaneurysm developed in both cases. The massive bleeding was stopped by an emergency surgical bypass, with the removal of the stented artery. These two cases show the possibility of SFA rupture after stenting. Previous surgical treatment, the site of stenting (first part of the SFA) and an active infection could predispose patients to this life-threatening complication.

Posterior fossa vestibular neurotomy as primary surgical treatment of Menière's disease: a re-evaluation.

Fifty-eight patients underwent vestibular neurotomy via the posterior fossa approach between September 1992 and December 1998 at the ENT department of Legnano. All patients presented a history of disabling unilateral Menière's disease and underwent complete neuro-otologic evaluation following the 1985 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guidelines. All patients underwent MRI imaging, ABR and electronystagmographic testing before surgery. Objective analysis of results is reported using the criteria published by the Committee on Hearing and Equilibrium of the AAO-HNS in 1985. According to the AAO formula, 52 patients obtained a score of 0, indicating complete control of major vertigo spells, while four were classified within the 'substantial control' group. Immediate hearing results indicated that 93 per cent of the patients maintained a level within 10 dB from the pre-operative level. Only one patient experienced a subtotal hearing loss yet retained measurable hearing. No major complications were reported. We conclude that a retrosigmoid approach to vestibular neurotomy can be considered a safe and effective procedure in relieving medically refractory vertigo in Menière's disease while preserving the hearing. Tinnitus and long-term hearing deterioration are not influenced by the procedure.

[Trans-labyrinthine approach for the resection large and giant acoustic nerve neuromas]. / Abordaje translaberíntico para resección de neurinomas de gran tamaño y gigantes del nervio acústico.

The standard translabyrinthine approach for acoustic neuromas removal was introduced by W. House in 1964. After several years of experience the original translabyrinthine approach has been progressively modified into the current "enlarged" approach by extending the area of bone removal. This increased surgical field has made the translabyrinthine approach suitable for the removal of tumours of all sizes. We present our serie of 71 large (52) and giant (19) neuromas of the VIIIth nerve removed through a translabyrinthine approach between 1993 and 1998 at the ENT Department of Legnano.

Cloning and expression of a novel hepatitis B virus-binding protein from HepG2 cells.

A direct involvement of the hepatitis B virus (HBV) preS1-(21-47) sequence in virus attachment to cell membrane receptor(s) and the presence on the plasma membranes of HepG2 cells of protein(s) with receptor activity for HBV have been suggested by many previous experiments. In this study, by using a tetravalent derivative of the preS1-(21-47) sequence, we have isolated by affinity chromatography from detergent-solubilized HepG2 plasma membranes a 44-kDa protein (HBV-binding protein; HBV-BP), which was found to closely correspond to the human squamous cell carcinoma antigen 1 (SCCA1), a member of the ovalbumin family of serine protease inhibitors. Comparison of SCCA1 sequence with the sequence of the corresponding HBV-BP cDNA, cloned by polymerase chain reaction starting from RNA poly(A)(+) fractions extracted from HepG2 cells, indicated the presence of only four nucleotide substitutions in the coding region, leading to three amino acid changes. Intact recombinant HBV-BP lacked inhibitory activity for serine proteases such as alpha-chymotrypsin and trypsin but inhibited with high potency cysteine proteases such as papain and cathepsin L. Direct binding experiments confirmed the interaction of recombinant HBV-BP with the HBV preS1 domain. HepG2 cells overexpressing HBV-BP after transfection of corresponding cDNA showed a virus binding capacity increased by 2 orders of magnitude compared with untransfected cells, while Chinese hamster ovary cells, which normally do not bind to HBV, acquired susceptibility to HBV binding after transfection. Native HBV particle entry was enhanced in transfected cells. Both recombinant HBV-BP and antibodies to recombinant HBV-BP blocked virus binding and internalization in transfected cells as well as in primary human hepatocytes in a dose-dependent manner. Our findings suggest that this protein plays a major role in HBV infection.

N-terminal myristylation of HBV preS1 domain enhances receptor recognition.

The N-terminal portion of the large envelope protein of the human hepatitis B virus (HBV), the preS1 domain, plays a fundamental role in cell attachment and infectivity. Recent investigations have suggested that myristylation of preS1 Gly2 residue is essential for viral infectivity, but the importance of this post-translational modification on HBV-receptor interaction has not been elucidated completely. In this study we produced, using stepwise solid-phase chemical synthesis, the entire preS1[1-119] domain (adw2 subtype), and compared its receptor binding activity with the myristylated form, myristyl-preS1[2-119] in order to define the importance of fatty acid modification. Both synthetic proteins were fully characterized in terms of structural identity using TOF-MALDI mass spectrometry and analysis of tryptic fragments. Circular dichroism measurements indicated a low content of ordered structure in the preS1 protein, while the propensity of the myristylated derivative to assume a conformationally defined structure was more evident. HBV-receptor binding assays performed with plasma membranes preparations from the hepatocyte carcinoma cell line HepG2 clearly showed that the preS1[1-119] domain recognizes the HBV receptor, and confirmed that binding is occurring through the 21-47 region. The myristylated derivative recognized HBV receptor preparations with higher affinity than the preS1 domain, suggesting that the conformational transitions induced in the preS1 moiety by fatty acid post-translational modification are important for efficient attachment of viral particles to HBV receptors.

[Petrous bone cholesteatoma: surgical strategy]. / I colesteatomi della rocca: strategia chirurgica.

Petrous bone cholesteatoma is a rare pathology which grows slowly and is often asymptomatic. This work presents a series of 25 cases of Petrous bone cholesteatoma and discusses the diagnostic impact, the surgical approach, the results and the complications. Currently our surgical orientation favors translabyrinthine and transcochlear approaches which, better than other ones, allow both radical excision of the lesion and preservation of the main neuro-vascular structures. Out of the 25 patients undergoing surgery, 22 were treated with the translabyrinthine (6 cases) or transcochlear (16 cases) approaches, in 1 case an infratemporal type A approach was used while the remaining 2 were treated with a median cranial fossa approach. Paralysis of the facial nerve is the most dreaded complication, particularly when a deficit is already present prior to surgery. In just a few cases did the hearing justify an attempt at preservation but in no case should this compromise radical removal of the cholesteatoma.

Purification and identification of ADP-ribosylated proteins from bull testis intact nuclei.

Isolated, intact bull testis nuclei were incubated with [14C] NAD. A large amount of radioactivity was associated to loosely bound chromosomal proteins extracted with 0.35M NaCl and fractionated with trichloroacetic acid. The labelled nuclear proteins included essentially a number of components belonging to the low mobility group. Mg2(+)-catalyzed alkali digestion of radioactive proteins and further analysis demonstrated that the final products were 5'-AMP and phospho-ribosyl-AMP, which arise from the hydrolysis of poly(ADP-ribose).