bluuebunny/crossref_metadata_2025 huggingface dataset:
COMT Val158Met polymorphism, cognitive stability and cognitive flexibility: an experimental examination
Authors: Rosa Elise C , Dickinson Dwight , Apud José , Weinberger Daniel R , Elvevåg Brita
Published: September 2010

Background

Dopamine in prefrontal cortex (PFC) modulates core cognitive processes, notably working memory and executive control. Dopamine regulating genes and polymorphisms affecting PFC - including Catechol-O-Methyltransferase (COMT) Val158Met - are crucial to understanding the molecular genetics of cognitive function and dysfunction. A mechanistic account of the COMT Val158Met effect associates the Met allele with increased tonic dopamine transmission underlying maintenance of relevant information, and the Val allele with increased phasic dopamine transmission underlying the flexibility of updating new information. Thus, consistent with some earlier work, we predicted that Val carriers would display poorer performance when the maintenance component was taxed, while Met carriers would be less efficient when rapid updating was required.

Methods

Using a Stroop task that manipulated level of required cognitive stability and flexibility, we examined reaction time performance of patients with schizophrenia (n = 67) and healthy controls (n = 186) genotyped for the Val/Met variation.

Results

In both groups we found a Met advantage for tasks requiring cognitive stability, but no COMT effect when a moderate level of cognitive flexibility was required, or when a conflict cost measure was calculated.

Conclusions

Our results do not support a simple stability/flexibility model of dopamine COMT Val/Met effects and suggest a somewhat different conceptualization and experimental operationalization of these cognitive components.
Silencing of RhoA and RhoC expression by RNA interference suppresses human colorectal carcinoma growth in vivo
Authors: Wang Haibo , Zhao Gang , Liu Xiangping , Sui Aihua , Yang Kun , Yao Ruyong , Wang Zongbao , Shi Qiang
Published: September 2010

Background

RhoA and RhoC have been proved to be over-expressed in many solid cancers, including colorectal cancer. The reduction of RhoA and RhoC expression by RNA interference (RNAi) resulted growth inhibition of cancer cells. The present study was to evaluate the effect of silencing of RhoA and RhoC expression by RNAi on growth of human colorectal carcinoma (CRC) in tumor-bearing nude mice in vivo.

Methods

To establish HCT116 cell transplantable model, the nude mice were subcutaneously inoculated with 1.0 × 107 HCT116 cells and kept growing till the tumor xenografts reached 5-7 mm in diameter. Then the mice were randomly assigned to three groups(seven mice in each group): (1) normal saline(NS) group, (2)replication-defective recombinant adenovirus carrying the negative control shRNA (Ad-HK) group and (3)replication-defective recombinant adenovirus carrying the 4-tandem linked RhoA and RhoC shRNAs (Ad-RhoA-RhoC) group. Ad-HK (4 × 108 pfu, 30 ul/mouse), Ad-RhoA-RhoC (4 × 108 pfu, 30 ul/mouse) or PBS (30 ul/mouse) was injected intratumorally four times once every other day. The weight and volumes of tumor xenografts were recorded. The levels of RhoA and RhoC mRNA transcripts and proteins in tumor xenografts were detected by reverse quantitative transcription polymerase chain reaction (QRT-PCR) and immunohistochemical staining respectively. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to detect the death of cells.

Results

The xenografts in mice could be seen at 5th day from the implantation of HCT116 cells and all had reached 5-7 mm in size at 9th day. After injection intratumorally, the growth speed of tumor xenografts in Ad-RhoA-RhoC group was significantly delayed compared with those in NS and Ad-HK group(P < 0.05). The results of QRT-PCR showed that mRNA levels of RhoA and RhoC reduced more in Ad-RhoA-RhoC group than those in NS and Ad-HK group. The relative RhoA and RhoC mRNA transcripts were decreased to 48% and 43% respectively (P < 0.05). Immunohistochemical analyses of tumor xenograft sections also revealed the decreased RhoA and RhoC expression in Ad-RhoA-RhoC group. TUNEL assay also showed higher death of tumor xenograft tissue cells in Ad-RhoA-RhoC group.

Conclusion

Recombinant adenovirus mediated RhoA and RhoC shRNA in tandem linked expression may inhibit the growth of human colorectal tumor xenografts in vivo. These results indicate that RhoA and RhoC might be potential targets for gene therapy in colorectal cancer.
The Algebraic Degree of Phase-Type Distributions
Authors: Fackrell Mark , He Qi-Ming , Taylor Peter , Zhang Hanqin
Published: September 2010

This paper is concerned with properties of the algebraic degree of the Laplace-Stieltjes transform of phase-type (PH) distributions. The main problem of interest is: given a PH generator, how do we find the maximum and the minimum algebraic degrees of all irreducible PH representations with that PH generator? Based on the matrix exponential (ME) order of ME distributions and the spectral polynomial algorithm, a method for computing the algebraic degree of a PH distribution is developed. The maximum algebraic degree is identified explicitly. Using Perron-Frobenius theory of nonnegative matrices, a lower bound and an upper bound on the minimum algebraic degree are found, subject to some conditions. Explicit results are obtained for special cases.
Stochastic Integrals and Conditional Full Support
Authors: Pakkanen Mikko S.
Published: September 2010

We present conditions that imply the conditional full support (CFS) property, introduced in Guasoni, Rásonyi and Schachermayer (2008), for processes Z := H + ∫K dW, where W is a Brownian motion, H is a continuous process, and processes H and K are either progressive or independent of W. Moreover, in the latter case, under an additional assumption that K is of finite variation, we present conditions under which Z has CFS also when W is replaced with a general continuous process with CFS. As applications of these results, we show that several stochastic volatility models and the solutions of certain stochastic differential equations have CFS.
Recurrence Equations for the Probability Distribution of Sample Configurations in Exact Population Genetics Models
Authors: Lessard Sabin
Published: September 2010

Recurrence equations for the number of types and the frequency of each type in a random sample drawn from a finite population undergoing discrete, nonoverlapping generations and reproducing according to the Cannings exchangeable model are deduced under the assumption of a mutation scheme with infinitely many types. The case of overlapping generations in discrete time is also considered. The equations are developed for the Wright-Fisher model and the Moran model, and extended to the case of the limit coalescent with nonrecurrent mutation as the population size goes to ∞ and the mutation rate to 0. Computations of the total variation distance for the distribution of the number of types in the sample suggest that the exact Moran model provides a better approximation for the sampling formula under the exact Wright-Fisher model than the Ewens sampling formula in the limit of the Kingman coalescent with nonrecurrent mutation. On the other hand, this model seems to provide a good approximation for a Λ-coalescent with nonrecurrent mutation as long as the probability of multiple mergers and the mutation rate are small enough.
Limit Theorems for a Generalized ST Petersburg Game
Authors: Gut Allan
Published: September 2010

The topic of the present paper is a generalized St Petersburg game in which the distribution of the payoff X is given by P(X =
sr(k-1)/α) = pqk-1,
k = 1, 2,…, where p + q = 1, s = 1 / p,
r = 1 / q, and 0 < α ≤ 1. For the case in which α = 1, we extend Feller's classical weak law and Martin-Löf's theorem on convergence in distribution along the 2n-subsequence. The analog for 0 < α < 1 turns out to converge in distribution to an asymmetric stable law with index α. Finally, some limit theorems for polynomial and geometric size total gains, as well as for extremes, are given.
Sum the Multiplicative Odds to One and Stop
Authors: Tamaki Mitsushi
Published: September 2010

We consider the optimal stopping problem of maximizing the probability of stopping on any of the last m successes of a sequence of independent Bernoulli trials of length n, where m and n are predetermined integers such that 1 ≤ m < n. The optimal stopping rule of this problem has a nice interpretation, that is, it stops on the first success for which the sum of the m-fold multiplicative odds of success for the future trials is less than or equal to 1. This result can be viewed as a generalization of Bruss' (2000) odds theorem. Application will be made to the secretary problem. For more generality, we extend the problem in several directions in the same manner that Ferguson (2008) used to extend the odds theorem. We apply this extended result to the full-information analogue of the secretary problem, and derive the optimal stopping rule and the probability of win explicitly. The asymptotic results, as n tends to ∞, are also obtained via the planar Poisson process approach.
Branching Process Approach for 2-Sat Thresholds
Authors: Mossel Elchanan , Sen Arnab
Published: September 2010

It is well known that, as n tends to ∞, the probability of satisfiability for a random 2-SAT formula on n variables, where each clause occurs independently with probability α / 2n, exhibits a sharp threshold at α = 1. We study a more general 2-SAT model in which each clause occurs independently but with probability αi / 2n, where i ∈ {0, 1, 2} is the number of positive literals in that clause. We generalize the branching process arguments used by Verhoeven (1999) to determine the satisfiability threshold for this model in terms of the maximum eigenvalue of the branching matrix.
Gibbs Random Fields with Unbounded Spins on Unbounded Degree Graphs
Authors: Kondratiev Yuri , Kozitsky Yuri , Pasurek Tanja
Published: September 2010

Gibbs fields are constructed and studied which correspond to systems of real-valued spins (e.g. systems of interacting anharmonic oscillators) indexed by the vertices of unbounded degree graphs of a certain type, for which the Gaussian Gibbs fields need not be existing. In these graphs, the vertex degree growth is controlled by a summability requirement formulated with the help of a generalized Randić index. In particular, it is proven that the Gibbs fields obey uniform integrability estimates, which are then used in the study of the topological properties of the set of Gibbs fields. In the second part, a class of graphs is introduced in which the mentioned summability is obtained by assuming that the vertices of large degree are located at large distances from each other. This is a stronger version of the metric property employed in Bassalygo and Dobrushin (1986).
Positive Dependence of Signals
Authors: Denuit Michel
Published: September 2010

In this paper we further investigate the problem considered by Mizuno (2006) in the special case of identically distributed signals. Specifically, we first propose an alternative sufficient condition of crossing type for the convex order to hold between the conditional expectations given signal. Then, we prove that the bivariate (2,1)-increasing convex order ensures that the conditional expectations are ordered in the convex sense. Finally, the L2 distance between the quantity of interest and its conditional expectation given signal (or expected conditional variance) is shown to decrease when the strength of the dependence increases (as measured by the (2,1)-increasing convex order).
Simultaneous localization and mapping: swarm robot mutual localization and sonar arc bidirectional carving mapping
Authors: Xu S , Ji Z , Pham D T , Yu F
Published: September 2010

This work primarily aims to study robot swarm global mapping in a static indoor environment. Due to the prerequisite estimation of the robots' own poses, it is upgraded to a simultaneous localization and mapping (SLAM) problem. Five techniques are proposed to solve the SLAM problem, including the extended Kalman filter (EKF)-based mutual localization, sonar arc bidirectional carving mapping, grid-oriented correlation, working robot group substitution, and termination rule. The EKF mutual localization algorithm updates the pose estimates of not only the current robot, but also the landmark-functioned robots. The arc-carving mapping algorithm is to increase the azimuth resolution of sonar readings by using their freespace regions to shrink the possible regions. It is further improved in both accuracy and efficiency by the creative ideas of bidirectional carving, grid-orientedly correlated-arc carving, working robot group substitution, and termination rule. Software simulation and hardware experiment have verified the feasibility of the proposed SLAM philosophy when implemented in a typical medium-cluttered office by a team of three robots. Besides the combined effect, individual algorithm components have also been investigated.
The effect of temperature variation on the free vibration of a simply supported curved sandwich beam with a flexible core
Authors: Alashti R A , Kashiri N
Published: September 2010

In this article, the free vibration of a singly curved sandwich beam with a transversely flexible core under various temperature conditions is investigated. The beam is assumed to have a constant width with simply supported end conditions. The core and face sheets are considered to be made of materials with temperature-dependent mechanical properties. In this model, faces of the sandwich beam are treated as thin beams with negligible shear strain and flexural rigidities obeying Bernoulli's assumptions. The analysis is based on the high-order sandwich panel theory. The core is assumed to possess vertical normal and shear stiffness and act as a medium that transfers its inertia load to face sheets. Equations of motion and boundary conditions are derived using Hamilton's principle. The variation of free vibration frequencies and eigenmodes of the beam with temperature variation considering the temperature gradient across the thickness is studied. The effect of geometrical parameters such as the ratios of the length and the thickness to the mean radius of the beam on the vibration response of the beam is investigated. It is found that the free vibration frequency of the beam would decrease when its temperature is increased.
Vibration response of coupled rotor systems with crack and misalignment
Authors: Patel T H , Zuo M J , Darpe A K
Published: September 2010

Earlier research on the vibration signatures of a crack or misalignment fault have typically been attempted considering one fault at a time. The condition of simultaneous existence of crack and misalignment (in addition to unbalance) was ignored. However, prolonged existence of misalignment preload could develop a fatigue crack in the rotor shaft. The present study aims to investigate the steady-sate vibration response of misaligned coupled rotors with a crack on one of the rotor shafts. This is perhaps the first study where unbalance, crack, and misalignment faults are considered simultaneously. Along with the axial and torsional vibration features, a detailed full spectrum analysis is carried out to reveal the fault-specific whirl signatures. Two new whirl parameters δ1 and δ2 were introduced based on differences in forward and backward whirling 1X and 2X spectral components. The influence of misalignment level and type, crack size, and crack location on these parameters is investigated for examining the effect of growth of one fault on the whirl nature of the vibration motion of the rotors with coexisting faults (i.e. unbalance, crack, and misalignment). The effects of a fault growth on the whirl parameters are found to be typical of a fault for crack and parallel misalignment faults. However, for the angularly misaligned rotors, the increase in misalignment level results in decrease/no change in the parameter δ2 in the presence/absence of a crack. This non-linear trend of the δ2 parameter cannot be related to any single fault, but it is typical of the coexisting faults.
Mathematical modelling of the fibre laser surface processing of a zirconia engineering ceramic by means of three-dimensional finite-element analysis
Authors: Shukla P P , Lawrence J
Published: September 2010

The thermal effects of fibre laser surface treatment on a ZrO2 engineering ceramic were studied using a computational finite-element model (FEM). Temperature increases on the surface and the bulk of the ZrO2 during the fibre laser processing were measured using an infra-red thermometer and specifically located thermocouples. The results showed an error of 5 per cent with the surface and 18 per cent within the bulk of the ZrO2 when comparing the experimental readings with those of the FEM. The FEM revealed a relationship between the traverse speed, power density, time, depth, and the temperature during various stages of the fibre laser surface treatment of the ZrO2. By utilizing data obtained from a thermogravimetry-differential scanning calorimetry (TG-DSC), the FEM predictions of the temperature distribution were used to map phase transformations and significant events occurring during the fibre laser surface treatment of the ZrO2. The mapping revealed that the fibre laser surface treatment generally resulted in a phase transformation of the ZrO2 at various temperatures changes as further shown in the article.
Aortic elastic properties in patients with venous thromboembolism
Authors: Duran N E , Oğuz E , Duran I , Aykan A Ç , Ertürk E , Bayram Z , Gürsoy M O , Biteker M , Karavelioğlu Y , Kaya H , Özkan M
Published: September 2010

Objectives

The relationship between venous thrombosis (VT) and atherosclerosis is controversial in recent studies. Aortic elastic properties have a predictive value in detecting early stages of atherosclerosis. The aim of this study is to evaluate the relationship between aortic elastic properties and VT.

Methods

Elastic properties of aorta in patients with spontaneous VT, without history of known cardiovascular disease and cardiovascular risk factors ( n: 31), and in healthy subjects without cardiovascular risk factors ( n: 30) were compared. Elastic properties of the aorta were assessed with transthoracic echocardiography.

Results

A significant increase in aortic stiffness index (6.5 ± 1.0 versus 6 ± 0.7, P = 0.03) and a significant decrease in aortic strain and aortic distensibility were found in patients with VT compared with healthy subjects (8.4 ± 7 versus 13 ± 8, P = 0.01, 4.9 ± 4.8 versus 6.5 ± 4.4, P = 0.03, respectively).

Conclusions

Elastic properties of aorta in patients with spontaneous VT were impaired. These results may support the role of endothelial dysfunction in the pathogenesis of VT.
Venous malformation: update on aetiopathogenesis, diagnosis and management
Authors: Dompmartin A , Vikkula M , Boon L M
Published: September 2010

The aim of this review was to discuss the current knowledge on aetiopathogenesis, diagnosis and therapeutic management of venous malformations (VMs). VMs are slow-flow vascular anomalies. They are simple, sporadic or familial (cutaneomucosal VMs or glomuvenous malformations), combined (e.g. capillaro-venous and capillaro-lymphaticovenous malformations) or syndromic (Klippel–Trenaunay, blue rubber bleb naevus and Maffucci). Genetic studies have identified causes of familial forms and of 40% of sporadic VMs. Another diagnostic advancement is the identification of elevated d-dimer level as the first biomarker of VMs within vascular anomalies. Those associated with pain are often responsive to low-molecular-weight heparin, which should also be used to avoid disseminated intravascular coagulopathy secondary to intervention, especially if fibrinogen level is low. Finally, development of a modified sclerosing agent, ethylcellulose–ethanol, has improved therapy. It is efficient and safe, and widens indications for sclerotherapy to sensitive and dangerous areas such as hands, feet and periocular area.
Epidemiology and risk factors for varicose veins among older people: cross-sectional population study in the UK
Authors: Clark A , Harvey I , Fowkes F G R
Published: September 2010

Background

There are many hypotheses concerning risk factors for the development of varicose veins based mostly on pathophysiological plausibility. Population studies have been carried out mostly on the middle aged with relatively few on elderly populations.

Objectives

To investigate epidemiological risk factors for varicose veins in an elderly population in the UK.

Methods

The South Wales Skin Cancer study – an examination survey undertaken between 1988 and 1991 of a random sample ( n = 792) drawn from all patients aged 60 and over registered with a general practitioner in South Glamorgan. Exposure variables were obtained from a structured administered questionnaire combined with clinical examination. Unadjusted and adjusted odds ratios were estimated using logistic regression.

Results

The response rate was 71% with an average age of 71 years (range 60–97). The age-adjusted prevalence of trunk varices was 63.2% (95% confidence interval [CI] 57.9–68.4%) in men and 57.0% (95% CI 50.6–63.4%) in women. In a multiple logistic regression the significant risk factors for varicose veins were increasing age ( P value = 0.001), obesity (odds ratio [OR] 3.28, 95% CI 1.25–8.63, P = 0.042), self-reported history of deep vein thrombosis (DVT) (OR 3.19, 1.16–8.78, P = 0.024) and history of hypertension (OR 0.58, 0.38–0.89, P = 0.013). The results for gender suggested that women were at greater risk than men, but this was not statistically significant (OR 1.53, 0.99–2.38, P = 0.056).

Conclusion

Trunk varices occur very commonly in older age groups with increasing age, obesity and possibly female sex as risk factors. Associations found with DVT and hypertension were based on history alone and must be interpreted with caution.
Duplex scanning is no substitute for surgical expertise in identifying the saphenopopliteal junction: results following short saphenous vein surgery
Authors: Sonnenberg S , Gowland-Hopkins N F
Published: September 2010

Objectives

Short saphenous vein (SSV) surgery carries a high risk of failure to identify the saphenopopliteal junction (SPJ). We assessed the impact of surgical expertise on anatomical outcome from SSV surgery and the role of preoperative duplex SPJ marking in improving outcome for vascular and non-vascular specialists.

Methods

A retrospective analysis identified patients (30 limbs) who had undergone SSV surgery. These were recalled for duplex scanning of the SPJ. In a prospective study, 187 limbs had preoperative duplex marking of SPJ and postoperative duplex to assess outcome. Grade of operating surgeon was recorded in both retrospective and prospective analysis.

Results

In both retrospective and prospective analysis, vascular specialists were significantly more likely than non-vascular specialists to correctly identify the SPJ ( P < 0.0001). Preoperative SPJ marking did not improve outcome for the vascular specialist or the non-vascular specialist.

Conclusion

Preoperative SPJ marking is no substitute for surgical expertise. Competence in SSV surgery should be assessed prior to surgeons proceeding to independent practice.
Triple-lumen double-balloon catheter for foam sclerotherapy of the great saphenous vein: critical review on preliminary results
Authors: Reich-Schupke S , Altmeyer P , Stücker M
Published: September 2010

Background

Different catheters (angiography, single-balloon) have been used for foam sclerotherapy of the great saphenous vein (GSV).

Objective

Is there greater efficacy and safety in the use of a double-balloon catheter?

Methods

Twenty patients were treated with a double-balloon catheter and 3% polidocanol foam. Follow-up after one day, one and six weeks, six and 12 months.

Results

Up to week six complete success was seen in 95% (19/20) patients. Only eight patients attended the checks after six and 12 months. The occlusion rates were 75% (6/8, 6 months) resp. 50% (4/8, 12 months). A further 10 patients refused these checks as they were free of symptoms but could be questioned. Side-effects were haematoma (100%), limited phlebitis (15%) and one extended thrombophlebitis followed by hyperpigmentation.

Conclusion

A double-balloon catheter is a safe treatment option for foam sclerotherapy of the GSV. However, in this case series efficacy is not superior to the use of an angiography-catheter, a single-balloon catheter or just the direct puncture of the vein.
Pathophysiology of visual disturbances occurring after foam sclerotherapy
Authors: Gillet J L , Donnet A , Lausecker M , Guedes J M , Guex J J , Lehmann P
Published: September 2010

Background

Visual disturbances (VDs) are reported with an average rate of 1.4% after foam sclerotherapy (FS). Some clinical clues indicate that they could correspond to migraine with aura (MA).

Aims

To validate the hypothesis that VDs occurring after FS correspond to MA and are not transient ischaemic cerebro-vascular events.

Method

A prospective multicentre study was carried out by the French Society of Phlebology in collaboration with the Neurology Department of the Marseille University Hospital (France). We included prospectively and consecutively all patients who experienced VDs after FS using air to make the foam. The patients were assessed (1) clinically with a specific form describing procedures of FS and recording neurological symptoms, later analysed by a neurologist specialized in migraine; and (2) by a brain diffusion-weighted magnetic resonance imaging (MRI) (T1, T2, T2*, diffusion) carried out within two weeks and analysed by a neuroradiologist.

Results

Twenty patients, 16 women and four men, were included in 11 phlebology clinics. All kinds of veins were treated. VDs occurred in average seven minutes after FS. Clinical assessment showed that VDs presented characteristics of MA in all patients, with headache in 10 and without in 10. Paresthesia was observed in five patients and dysphasic speech disturbance in one. Fifteen patients (75%) had a personal history of migraine. Fifteen MRIs were performed within two weeks (mean: 8 days) and three were late (26 days). All of them were normal. MRI was not performed in two patients.

Conclusion

These results show that VDs occurring after FS correspond to MA and are not transient ischaemic cerebro-vascular events. We suggest a pathophysiological hypothesis resting on the release of endothelin that would reach the cerebral cortex through a paten foramen ovale.
Traveller's thrombosis: airlines still not giving passengers the WRIGHT advice!
Authors: Scurr J R H , Ahmad N , Thavarajan D , Fisher R K
Published: September 2010

Introduction

This study has examined the impact of the World Health Organization's Research into Global Hazards of Travel (WRIGHT) Project's phase 1 report on the information given by airlines to their passengers regarding traveller's thrombosis.

Methods

Official websites of all airlines flying from Heathrow (UK) and John F Kennedy (USA) were located through links on the websites of these two busy international airports. In June 2007, each site was scrutinized by three independent researchers to identify if traveller's thrombosis and its risk factors were discussed and what methods of prevention were advised. This exercise was repeated a year after the publication of the WRIGHT report.

Results

One hundred and nineteen international airlines were listed in 2007 (12 were excluded from analysis). A quarter (27/107) of airlines warned of the risk of traveller's thrombosis. A year later, five airlines were no longer operational and there had been no increase in the discussion of traveller's thrombosis (23/102). Additional risk factors discussed in June 2007 versus September 2008: previous venous thromboembolism (16%, 15%); thrombophilia (14%, 15%); family history (11%, 9%); malignancy (12%, 14%); recent surgery (19%, 16%); pregnancy (17%, 16%) and obesity (11%, 12%). Prophylaxis advice given in June 2007 versus September 2008: in-flight exercise (34%, 42%); Hydration (30%, 34%); medical consultation prior to flying (20%, 18%); graduated compression stockings (13%, 12%); aspirin (<1%, <1%) and heparin (5%, 7%).

Conclusions

The majority of world airlines continue to fail to warn of the risk of traveller's thrombosis or offer appropriate advice. Alerting passengers at risk gives them an opportunity to seek medical advice before flying.
Management of deep vein thrombosis to reduce the incidence of post-thrombotic syndrome
Authors: Lowe G D O
Published: September 2010

The post-thrombotic syndrome (PTS) is the major chronic sequel of deep vein thrombosis (DVT) of the leg, and is a major socioeconomic challenge. In addition to systematic prophylaxis of DVT in hospitalized patients, effective management of DVT is important to reduce the incidence of PTS. Thrombolysis and thrombectomy are not indicated routinely. Optimal anticoagulation, usually with heparins initially and then with oral warfarin, is important to prevent recurrent DVT, which is a major risk factor for PTS. Following a routine three-month period of anticoagulation, patients with proximal idiopathic DVT should be individually assessed for the benefits and risks of continued oral anticoagulation, including patient preferences. Risk factors for recurrent DVT include active cancer, pregnancy, continued use of oral oestrogens, male sex, obesity, recurrent thrombosis, established PTS, permanent inferior vena caval filters, residual DVT, high fibrin D-dimer and other thrombophilias. Early walking, continued high levels of physical activity and wearing compression stockings for up to two years may also reduce the risk of PTS.
Post-thrombotic syndrome: prevention is better than cure
Authors: Saedon M , Stansby G
Published: September 2010

Post-thrombotic syndrome (PTS) can be debilitating to patients and have a major economic impact on health-care services. It arises after deep venous thrombosis (DVT) due to residual venous obstruction or valvular reflux, leading to increased venous pressure in the microcirculation. While the inflammatory process at the time of DVT may aid thrombus resolution, it may also promote destruction of venous valves. The diagnosis of PTS is principally clinical and patients typically complain of leg heaviness, swelling, pain, itching, cramps, ulcer and signs of lipodermatosclerosis. Several clinical scales or classifications have been used but it is recommended that Villalta scale is the most suitable. Risk factors for PTS include a proximal DVT and recurrent thrombosis as well as obesity and prior varicose veins. Poor quality of anticoagulation control may also be a factor. Established PTS is usually managed along the same lines as chronic venous hypertension with compression therapy and leg elevation. Surgery has only a limited role but may benefit some patients. Further trials are desperately needed to define the role of acute thrombolysis and mechanical thrombectomy, which seem to be promising treatments in the studies to date. For patients who have had a DVT more attention should be given to prescribing and using compression hosiery.
Leg ulceration: the importance of treating the underlying pathophysiology
Authors: Ghauri A S K , Nyamekye I K
Published: September 2010

The last 20 years have seen considerable advances in the management of vascular diseases both in non-invasive imaging and minimally invasive surgical interventions. Colour duplex ultrasonography provides non-invasive and increasingly high-resolution anatomic and haemodynamic vascular information. This has been complimented by the development of minimally invasive interventional procedures such as subintimal angioplasty and endovenous treatments, all of which can be performed under local anaesthesia. These advances can now be utilized to improve both the assessment and management of patients with chronic leg ulceration where the aetiology is usually vascular and mostly primary venous insufficiency. Using non-invasive Doppler pressures and colour duplex imaging, the anatomic and haemodynamic pattern of the underlying vascular disease (and consequently the pathophysiology) can be precisely determined. This enables appropriate planning and targeting of effective management from an early stage in the history of any particular ulcer. This paper highlights the importance of achieving accurate diagnosis and instituting effective treatments that are appropriately targeted at the underlying pathophysiology, in patients with chronic leg ulceration, and describes how recent advances in technology and interventions have substantially increased the tools available to the vascular specialist. Thus allowing safe and effective management of what can otherwise become a prolonged or recurrent disease process.
A simple prognostic scoring system for typhoid ileal perforation peritonitis
Authors: Singh Hemant , Mishra Arpan , Sharma Dhananjaya , Somashekar Uday
Published: September 2010

The increasing awareness of the worse than expected outcome after typhoid ileal perforation (TIP) prompted us to prospectively prognosticate patients with the help of the Jabalpur prognostic score (JPS), a simplified scoring system for peptic perforation peritonitis (PPP). Eighty-two consecutive patients with TIP were studied from May 2005 to August 2008 in the Department of Surgery, NSCB Government Medical College, Jabalpur (MP), India. Six parameters used in the JPS were recorded: age, heart rate, mean blood pressure, serum creatinine, any co-morbid illness and perforation-operation interval. JPS correlated with morbidity and mortality in TIP patients and, as the score increased, so did the morbidity and mortality. Survivors had a significantly lower mean score (3.86 ± 2.23) than non-survivors (7.94 ± 3.6; P < 0.001). Expectedly, TIP patients had worse outcome, stage by stage, than PPP patients. JPS can be easily modified for TIP (JPS-TIP) and can be easily used for its prognostication.
Antimicrobial drug use in a small Indian community hospital
Authors: Blomberg M , Jensen M Blomberg , Henry A , Singh S T , Banipal R P Singh , da Cunha-Bang C , Bygbjerg I C
Published: September 2010

Antimicrobial drug use and overuse have been a topic of interest for many years, lately focusing on the growing resistance worldwide. This study was conducted in a small Indian hospital, where more than 80% of all admitted patients received antimicrobial drugs. Penicillin, gentamycin, co-trimoxazole, ciprofloxacin and metronidazole were most commonly used and all antimicrobial drugs were given empirically with no confirmation of the infective agent. Reports of increasing resistance to antimicrobial drugs in India, and elsewhere, necessitates a focus on how antimicrobials drugs are used in relation to investigations of resistance patterns among the local strains of pathogens. This study may be considered a base-line study, though of relevance for other hospitals, in particular in low-income areas, where development of resistance to standard antimicrobial drugs may have severe implications for both patients and health managers.
An innovative and cost-effective way of managing ankle fractures prior to surgery – home therapy
Authors: Lloyd John M , Martin Rachel , Rajagopolan Senthil , Zieneh Nedal , Hartley Richard
Published: September 2010

INTRODUCTION

Ankle fractures are common injuries affecting all age groups and constitute a large proportion of the orthopaedic trauma case load. Patients are usually admitted directly to the ward from the emergency department and a large number of bed-days are spent waiting for the ankle swelling to subside prior to surgery. We audited current practice and then implemented a home therapy programme (HTP). The purpose of the study was to assess the pioneering HTP with respect to cost effectiveness, length of stay and patient satisfaction.

PATIENTS AND METHODS

If HTP criteria were met, patients with reduced, unstable ankle fractures were taught safe mobilisation by physiotherapists in the emergency department. They were then discharged home to ice and elevate their ankle in a plaster backslab. A provisional operation date was allocated on discharge. They were admitted to hospital the day of surgery and then discharged home when safe and comfortable.

RESULTS

Forty-three consecutive patients met our inclusion criteria and underwent surgical fixation of unstable ankle fractures over a 3-month period (February–April 2008). The average length of hospital stay was 8 days (range, 1–18 days), 4.5 days pre-operatively and 3.5 days postoperatively. Patients were frustrated and dissatisfied with the whole process. In total, 177 patients underwent surgical fixation of unstable ankle fractures over an 11-month period (November 2008 to October 2009) and, of these, 59 met the home therapy criteria. The average length of hospital stay was 2.4 days, 1 day pre-operatively (range, 0–4 days) and 1.4 days postoperatively (range, 0–5 days). All HTP patients expressed satisfaction with the process. Over the course of the HTP, 354 bed-days were saved which equates to a saving of £81,774. The annual estimated cost saving is £90,000.

CONCLUSIONS

The home therapy programme has proved effective in reducing hospital stay both pre- and postoperatively. It is cost-effective and well received by patients.
The S-Plus lift: a short-scar, long-flap rhytidectomy
Authors: Hopping Steven B , Janjanin Sasa , Tanna Neil , Joshi Arjun S
Published: September 2010

INTRODUCTION

As rhytidectomy is one of the most elective surgical procedures, there is a strong trend toward less aggressive operative techniques. The authors introduce the S-Plus lift, a ‘long flap’ superficial musculo-aponeurotic system (SMAS) imbrication technique that diminishes risks, decreases recovery time, and yields long-lasting results.

PATIENTS AND METHODS

This paper describes a novel approach to mid-facial rejuvenation that combines the limited incision of an S-lift with two SMASectomies, purse-string suture imbrication of the extended supraplatysmal plane (ESP) and SMAS, and malar soft tissue suspension. SMAS excisions are performed pre-auricularly, and in the region overlying the anterior edge of the parotid gland. Purse-string imbrication sutures are designed to close the SMAS defects, pull the soft tissues of the neck upward, pull the jowl and lower face posteriorly and superiorly, and tighten the platysma. Ancillary purse-string suture lifts the malar fat pad and cheek soft tissues vertically, which achieves mid-face fullness and lifting. Compared to S-lift, the technique extends its efficacy in those patients who have moderate-to-severe mid-facial laxity, prominent nasolabial folds, and platysma redundancy.

RESULTS

A review of 144 consecutive S-Plus lifts performed by a single surgeon (SBH), with at least 6 months of follow-up, was performed. Over a 3-year period, 130 (90.3%) females and 14 (9.7%) males underwent S-Plus lift. S-Plus lift as primary rhytidectomy was performed in 132 (91.7%) and as secondary in 12 (8.3%) cases. Complication rate was low and comparable with other techniques of rhytidectomy.

CONCLUSIONS

The S-Plus lift is a novel, hybrid technique with pleasing results, short down-time, and high patient satisfaction rate. The technique combines two SMASectomies with purse-string suture imbrication of the ESP and SMAS, and malar fat suture suspension.
Audit-induced change reduces complications of the Ganz trochanteric flip approach
Authors: Guyver PM , Cattell A , Reddy RP , Edwards C , Williams D , Dixon SM , Norton MR , Fern ED
Published: September 2010

INTRODUCTION

The Ganz trochanteric flip approach aims to avoid the potential risk of avascular necrosis in hip conserving surgery and may reduce the risk of femoral neck fractures, neck thinning and femoral head implant migration in hip resurfacing. Our initial audit revealed the complications of non-union and trochanteric screw irritation to be associated with this approach. We, therefore, modified our selection criteria and re-audited our results.

SUBJECTS AND METHODS

The initial audit (IA) ran between January 2003 and November 2007 after which an age limit of 50 years was recommended. The re-audit (RA) ran between November 2007 and December 2008 where one of the senior authors stopped using the approach in the over 50 year age group whilst the other senior author continued on selected patients over 50 years.

RESULTS

There were 545 hips in the IA and 152 hips in the RA group. The incidence of non-union decreased in the RA after the change of selection criteria (6.2% [IA] vs 1.3% [RA]). In both audit groups, the incidence of non-union increased with age, and in the RA no non-unions were observed under the age of 50 years. The incidence of screw irritation and the necessity for removal remained relatively unchanged (20.7% [IA] vs 28.3% [RA]) with a combined incidence of 22.4%.

CONCLUSIONS

The trochanteric flip approach to the hip can be used safely with an acceptable complication rate in young adult impingement and resurfacing surgery. Caution must, however, be exercised in patients over 50 years of age as they have a higher incidence of trochanteric non-union. In addition, all patients should be consented for the possibility of screw removal as a second procedure.
Fifteen years' experience in thyroid surgery
Authors: Watkinson John C
Published: September 2010

INTRODUCTION

Thyroid disease is common, thyroid cancer is uncommon. Most goitres are investigated using blood tests, fine needle aspiration cytology together with ultrasound. Surgery usually entails either lobectomy or total thyroidectomy, and for malignancy, patients may need a neck dissection. Recently, significant advances have been made regarding mechanisms involved in both thyroid growth and function (goitrogenesis) and carcinogenesis at a molecular level.

PATIENTS AND METHODS

In the study cohort, 1113 patients had benign disease and 387 malignancy. For benign disease, 716 patients had lobectomy or isthmusectomy, 44 had near-total thyroidectomy and 318 a total thyroidectomy. For malignancy, patients received initial lobectomy (180) or total thyroidectomy (152). One hundred and eleven had completion surgery. Thirty patients had extensive surgery. Thyroid growth and function was investigated using 500 human thyroid cell primary cultures obtained at surgery, as well as in three animal models. The role of pituitary tumour transforming gene (PTTG), PTTG binding factor (PBF) and sodium iodide symporter (NIS) in thyroid cell function was then evaluated.

RESULTS

Temporary and permanent recurrent laryngeal nerve palsy rates were 2.4% and 0.4%. Other complications included temporary (21%) and permanent (3%) hypoparathyroidism, wound infection (1.2%), haematoma (1.2%) and poor scar (0.8%). Six patients have died. Regarding thyroid growth and function, TSH represents (either directly or indirectly) the main factor mediating thyroid follicular cell growth. For carcinogenesis, over-expression of the proto-oncogenes PTTG and PBF induces tumours in nude mice, and PTTG can induce proliferation of human thyroid cells and, in addition, both repress expression and function of NIS.
Bilateral type 1 capitellar fractures: a case report
Authors: Sturridge Sabastian , Corbett Steven
Published: September 2010

There have been no cases of bilateral type I capitellar fractures reported in the UK, and only two reported world-wide. This report describes the clinical case of a 26-year-old woman, who fell sustaining this injury, and how careful management resulted in an excellent outcome. This case highlights the rarity of this injury, its potential morbidity, and an approach to its management which produces excellent clinical results.
Chyle leak following laparoscopic cholecystectomy: a rare complication
Authors: Gogalniceanu Petrut , Purkayastha Sanjay , Spalding Duncan , Zacharakis Emmanouil
Published: September 2010

Gallstone disease is a highly prevalent condition which is commonly and safely treated by laparoscopic cholecystectomy. We present the third reported case of chyle leakage following laparoscopic cholecystectomy in the setting of acute cholecystitis. The report reviews current literature on the prevalence, diagnosis and management of this condition.
Idiopathic retroperitoneal fibrosis of the pancreas versus pancreatic carcinoma
Authors: Baker Bilal , Salameh Habeeb , Daoud Faiez
Published: September 2010

We report one of few cases of idiopathic retroperitoneal fibrosis of the pancreas, which is different from the classical retroperitoneal fibrosis that affects ureters and vessels that mimicking locally advanced pancreatic carcinoma at presentation.
Acute presentation of intestinal malrotation in adults: a report of two cases
Authors: Hanna Thomas , Akoh Jacob A
Published: September 2010

Introduction

Intestinal malrotation is a rare developmental abnormality occurring as a result of incomplete rotation during fetal life. It usually presents in the first few weeks of life, but may persist unrecognised into adult life. We report two interesting cases in elderly patients both characterised by a significant diagnostic challenge due to atypical clinical and radiological signs and in one case an unusual complication following laparotomy.

Case Reports

The first case was a 64-year-old man initially treated for diverticulitis but at laparotomy was found to have malrotation of the midgut and a perforated left-sided appendicitis. The second case was a 76-year-old woman admitted with multiple fractures and increasing abdominal distension following a fall. Ten days after admission, she underwent right hemicolectomy to treat faecal peritonitis due to multiple caecal perforations complicating volvulus in the presence of midgut malrotation.

Conclusions

These cases illustrate challenges associated with managing patients with undiagnosed intestinal malrotation. Delayed diagnosis is a common feature in several case reports describing atypical presentation of appendicitis in patients with malrotation. While abdominal CT scan can remove much of the diagnostic uncertainty, the diagnosis of malrotation can be missed unless there is a high index of suspicion.
A peculiar case of bilateral, spontaneous thromboses of the pampiniform plexi
Authors: Kayes Oliver , Patrick Nina , Sengupta Anup
Published: September 2010

Acute thrombosis of the pampiniform plexus is an uncommon clinical problem which causes a diagnostic conundrum in men presenting urgently to medical personnel. We present an unusual case of a young man who presented with metachronous thromboses of his pampiniform plexi and review the literature to explore potential aetiologies and therapeutic strategies.
Varices of the round ligament mimicking an inguinal hernia – an important differential diagnosis during pregnancy
Authors: Dent BM , Al Samaraee A , Coyne PE , Nice C , Katory M
Published: September 2010

Pregnancy is a recognised risk factor for the development of inguinal hernias due to an increase in intra-abdominal pressure. Whilst often managed conservatively until after the pregnancy, if the hernia presents acutely as a painful or tender groin lump, urgent or emergency repair may be required. Many clinicians rely heavily on clinical examination alone in order to diagnose the presence of such a hernia. In pregnancy, however, in order to prevent unnecessary surgery, the use of ultrasound has a more important role to play in reaching this diagnosis. We report a cautionary case that highlights the need for ultrasound evaluation of all painful groin lumps in pregnant women prior to considering surgery.
Gastrointestinal stromal tumour presenting with duodenal-jejunal intussusception: a case report
Authors: Wall Michael L , Ghallab Mohammed A , Farmer Martin , Durkin Damien J
Published: September 2010

Duodenal-jejunal intussusception is an extremely rare occurrence and has never been reported in the context of a gastrointestinal stromal tumour (GIST). We present the case of a duodenal GIST which presented with major intestinal haemorrhage in addition to duodenal-jejunal intussusception.