Comparison of a modified Sugiura procedure with portal systemic shunt for prevention of recurrent variceal bleeding in cirrhosis

BACKGROUND: There is no agreement on the management of patients with cirrhosis and recurrent variceal bleeding after failure of medical or endoscopic treatments or both. Portal systemic shunts are highly effective in preventing rebleeding but are associated with a high incidence of chronic encephalopathy. This study compared the results of a slightly modified Sugiura procedure (esophageal transection plus esophagogastric devascularization plus splenectomy) with those of nonselective portal systemic shunts in patients with previous variceal bleeding. METHODS: Fifty-four patients were included in this randomized controlled study between January 1984 and April 1989. The major end point was chronic encephalopathy. Secondary end points were recurrent variceal bleeding, survival, ascites, and hepatocellular carcinoma. RESULTS: Twenty-seven patients were assigned to each group. The rate of chronic encephalopathy was significantly (p = 0.002) lower after modified Sugiura procedure than after portal systemic shunt. Recurrent variceal bleeding was more frequent after modified Sugiura procedure than after portal systemic shunt, but the difference is not significant. One-, two-, and three-year survival rates were 93%, 81%, and 67%, respectively, in the modified Sugiura group and 78%, 66%, and 39%, respectively, in the portal systemic shunt group (p = 0.044). CONCLUSIONS: These results suggest that the modified Sugiura procedure is better overall than the nonselective portal systemic shunt in the management of patients with cirrhosis and recurrent variceal bleeding. Although the rebleeding rate is higher after the modified Sugiura procedure, this does not seem to affect mortality in these patients.     

Laparoscopic cholecystectomy and gallbladder cancer: a diagnostic and therapeutic dilemma

The correct treatment strategy of patients with unsuspected gallbladder cancer undergoing laparoscopy, and the prevention of delayed diagnosis are current issues. We report a case of late diagnosis with umbilical metastasis and poor survival. A policy of careful inspection of the gallbladder and a cautious strategy in the case of gross alteration of its external morphology seems advisable during laparoscopic cholecystectomy. Although no agreement exists concerning the best treatment in the event of delayed diagnosis, the adopted strategy is contingent on patient status, disease stage and the possibility of performing appropriate follow-up.     

L-Expressnet: The Communication Subnetwork for the C-NET Project

L-Expressnet is the communication suxbnetwork for the CNET local area network project of the CNR, Italy. Based on a single bus topology, it utilizes a simple and efficient virtual-token access protocol which provides ordered and collision-free transmission. The paper discusses the needs which led to L-Expressnet, describes the protocol, proves its correct operation, and compares its throughput-delay performance with those of other typical bus Protocols. A major advantage of L-Expressnet is that its implementation may be based on Ethernet standard transceivers and network interfaces.     

Analogues of perillaketone as highly potent agonists of TRPA1 channel

Transient receptor potential (TRP) channels represent interesting molecular target structures involved in a number of different physiological and pathophysiological systems. In particular, TRPA1 channel is involved in nociception and in sensory perception of many pungent chemesthetic compounds, which are widespread in spices and food plants, including Perilla frutescens. A natural compound from P. frutescens (isoegomaketone) and 16 synthetic derivatives of perillaketone have been prepared and tested in vitro on rTRPA1 expressed in HEK293 cells and their potency, efficacy and desensibilisation activity measured. Most derivatives proved to be high potency agonists of TRPA1, with a potency higher than most natural agonists reported in the literature. These furylketones derivatives, represent a new class of chemical structures active on TRPA1 with many potential applications in the agrifood and pharmaceutical industry.     

A Monte Carlo methodological approach to plant availability modeling with maintenance, aging and obsolescence

In this paper we present a Monte Carlo approach for the evaluation of plant maintenance strategies and operating procedures under economic constraints. The proposed Monte Carlo simulation model provides a flexible tool which enables one to describe many of the relevant aspects for plant management and operation such as aging, repair, obsolescence, renovation, which are not easily captured by analytical models. The maintenance periods are varied with the age of the components. Aging is described by means of a modified Brown–Proschan model of imperfect (deteriorating) repair which accounts for the increased proneness to failure of a component after it has been repaired. A model of obsolescence is introduced to evaluate the convenience of substituting a failed component with a new, improved one. The economic constraint is formalized in terms of an energy, or cost, function; optimization studies are then performed using the maintenance period as the control parameter.     

Capture-division packet access for wireless personal communications

This paper presents a new architecture for the third-generation mobile systems, capture-division packetized access (CDPA), that overcomes most of the limitations of present cellular systems. It addresses the three main issues of radio access, namely the channel reuse, the multiple access, and the handover problems, in complete adherence to packet-switching principles. The CDPA channel reuse mechanism is a completely new alternative with respect to time-division, frequency-division, or code-division multiple-access (TDMA, FDMA, and CDMA, respectively), which achieve communication parallelism by subdividing the bandwidth a priori among cells. In CDPA, a single frequency channel is used and parallel transmissions are achieved through the “capture” capability of receivers. The hybrid reservation-polling multiple access mechanism used in CDPA is able to integrate any kind of traffic and guarantees almost immediate retransmission of packets that are not captured, thus assuring their correct reception. Finally, the packet-switching approach allows connectionless communications with any base station (BS), and eliminates the need for extra radio traffic in managing handovers. This turns out to be very effective in local area systems where the required high bandwidth is obtained by using a pico-cell structure. We present the CDPA architecture, discuss some implementation issues, and evaluate its performance under a variety of system parameters and operating conditions, using analytical and simulation methods     

Slotted ALOHA and CDPA: A comparison of channel accessperformance in cellular systems

The paper compares the performance of two channel-access schemes suitable for the cellular environment, which, in particular, allow the packet capture and can deal with inter-cell interference. The first scheme is the well known S-ALOHA while the second one is the Capture Division Packet Access, recently proposed. The comparison is analytically performed over a common system with a common analytical model. Despite the many analyses appeared on S-ALOHA, the one we develop is new because a throughput density uniformly distributed on the plane is considered in a multiple cell environment. The analysis clearly shows the effect of intra-cell and inter-cell interference on the ALOHA system and quantifies the throughput gain achieved by CDPA, which completely avoids intra-cell interference. Our analysis also provides insight about the effectiveness of power control on both systems. This revised version was published online in July 2006 with corrections to the Cover Date.     

Retransmissions versus FEC plus interleaving for real-timeapplications: a comparison between CDPA and MC-TDMA cellularsystems

The capacity of mobile cellular systems is mainly limited by cochannel interference. Commonly in multiple carrier-time division multiple access (MC-TDMA) systems, like the global system for mobile (GSM) communications, the interference noise is first reduced by means of channel clustering and slow frequency hopping. The residual interference, characterized by a level varying slot by slot, causes errors in burst which are spread with bit interleaving and fought with correcting codes for random errors. With real-time services like voice, no other error control technique, such as automatic repeat request (ARQ), is usually adopted. An alternative approach is given by capture division packet access (CDPA) where transmissions are spread in time adopting a dynamic slot assignment (DSA), and errors are dealt with a retransmission mechanism. In this paper, we present a comparison of this two approaches, and using a simple theoretic capacity analysis, we justify the better performance of CDPA. Moreover, by the delay performance analysis, we prove that in spite of its retransmission mechanism, CDPA is effective also with delay constrained services     

Large granular lymphocyte leukemia associated with hepatocellular carcinoma: a case report

Both primary and metastatic malignancies of the masseter muscle are rare. We report a case of metastatic renal cell carcinoma to the masseter muscle. It was incidentally found as a hypervascular mass in carotid angiography for delineating a recurrent metastatic brain tumour. Prior to surgical removal, intravascular embolization via the left facial artery was performed in order to decrease intra-operative bleeding. The tumour was removed with minimum damage to the muscle fibres by the extraoral method, followed by a transient lower lip palsy. Metastatic intramuscular tumours, which are assumed to be due to haematogenous spread, are generally a sign of poor prognosis.