Haemodynamic assessment following inferior vena cava resection without replacement

Background: Treatment of bulky retroperitoneal malignancy may require en bloc resection of the infrarenal inferior vena cava. A number of reconstructive options are available to the surgeon but objective haemodynamic assessment of the peripheral venous system following resection without replacement is lacking. The aim of the present paper was thus to determine the symptomatic and haemodynamic effects of not reconstructing the resected infrarenal inferior vena cava. Methods: A retrospective descriptive study was carried out at Princess Alexandra Hospital in Queensland. Five patients underwent resection of the thrombosed infrarenal inferior vena cava as part of retroperitoneal lymph node dissection for testicular cancer (n = 3), radical nephrectomy for renal cell carcinoma (n = 1) and thrombosed inferior vena cava aneurysm (n = 1). Clinical effects were determined via the modified venous clinical severity score and venous disability score. Haemodynamic data were obtained postoperatively using venous duplex ultrasound and air plethysmography. Results: None of the present patients scored >2 (out of 30) on the modified venous clinical severity score or >1 (out of 3) on the venous disability score. Haemodynamic studies showed only minor abnormalities. Conclusions: Not reconstructing the resected thrombosed infrarenal inferior vena cava results in minor signs and symptoms of peripheral venous hypertension and only minor abnormalities on haemodynamic assessment.

Narrowing of the inferior dental canal in relation to the lower third molars

Objectives: To assess narrowing of the inferior dental canal in the lower third molar regions using computed tomography (CT) and to determine the value of radiographic markers on rotational panoramic radiographs in assessing the true relationships of the inferior dental canal. Methods: Patients referred for CT assessment of impacted lower third molars were used in this study. The lower third molars were assessed using CT to determine the position and morphology of the inferior dental canal relative to the roots and the cortical plates. The radiographic markers on rotational panoramic radiographs were correlated with the CT findings when rotational panoramic radiographs were available. Results: The patients referred had 202 lower third molars. Inferior positioning of the inferior dental canal was the most common location on CT. Narrowing of the inferior dental canal was found in relation to the lower third molars in 66.8% of cases. The chance of narrowing of the inferior dental canal as shown using CT increased when at least one of the radiographic markers, superimposition, narrowing, deviation or reduction in density was present on the rotational panoramic radiograph. Deviation of the inferior dental canal on rotational panoramic radiographs was found to be the most significant predictor of narrowing of the inferior dental canal and a close relationship to the roots, as shown in CT. Conclusions: Narrowing of the inferior dental canal is a common finding when impacted lower third molars are assessed using CT. On rotational panoramic radiographs deviation of the inferior dental canal is the best predictor of narrowing of the inferior dental canal and a close relationship to the roots.

Equilibrium swelling measurements of network and semicrystalline polymers in supercritical carbon dioxide using high-pressure NMR

The extent of swelling of cross-linked poly(dimethylsiloxane) and linear low-density poly(ethylene) in supercritical CO2 has been investigated using high-pressure NMR spectroscopy and microscopy. Poly(dimethylsiloxane) was cross-linked to four different cross-link densities and swollen in supercritical CO2. The Flory-Huggins interaction parameter, x, was found to be 0.62 at 300 bar and 45 degrees C, indicating that supercritical CO2 is a relatively poor solvent compared to toluene or benzene. Linear low-density poly(ethylene) was shown to exhibit negligible swelling upon exposure to supercritical CO2 up to 300 bar. The effect Of CO2 pressure on the amorphous region of the poly(ethylene) was investigated by observing changes in the H-1 T-2 relaxation times of the polymer. These relaxation times decreased with increasing pressure, which was attributed to a decrease in mobility of the polymer chains as a result of compressive pressure.

The interlayer swelling and molecular packing in organoclays

Understanding the interlayer swelling and molecular packing in organoclays is important to the formation and design of polymer nanocomposites. This paper presents recent experimental and molecular simulation studies on a variety of organoclays that show a linear relationship between the increase of d-spacing and the mass ratio between organic and clay. A denser molecular packing is observed in organoclays containing surfactants with hydroxyl-ethyl units. Moreover, our simulation results show that the head (nitrogen) groups are essentially tethered to the clay surface while the long hydrocarbon chains tend to adopt a layering structure with disordered conformation, which contrasts with the previous assumptions of either the chains lying parallel to the clay surface or being tilted at rather precise angles. (c) 2005 Elsevier Inc. All rights reserved.

Disrupted cortical proprioceptive representation evokes symptoms of peculiarity, foreignness and swelling, but not pain

Objectives. It has been proposed that disruption of the internal proprioceptive representation, via incongruent sensory input, may underpin pathological pain states, but experimental evidence relies on conflicting visual input, which is not clinically relevant. We aimed to determine the symptomatic effect of incongruent proprioceptive input, imparted by vibration of the wrist tendons, which evokes the illusion of perpetual wrist flexion and disrupts cortical proprioceptive representation. Methods. Twenty-nine healthy and naive volunteers reported symptoms during five conditions: control, active and passive wrist flexion, extensor carpi radialis tendon vibration to evoke illusion of perpetual wrist flexion, and ulnar styloid (sham) vibration. No advice was given about possible illusions. Results. Twenty-one subjects reported the illusion of perpetual wrist flexion during tendon vibration. There was no effect of condition or of whether or not subjects reported an illusion on discomfort/pain (P > 0.28). Peculiarity, swelling and foreignness were greater during tendon vibration than during the other conditions, and greater during tendon vibration in those who reported an illusion of wrist flexion than in those who did not (P < 0.05 for all). Symptoms were reported by at least two subjects in each condition and four subjects reported systemic symptoms (e.g. nausea). Conclusions. In healthy volunteers, incongruent proprioceptive input does not cause discomfort or pain but does evoke feelings of peculiarity, swelling and foreignness in the limb.

Mechanisms involved in the swelling of erythrocytes caused by Pacific and Caribbean ciguatoxins

The mechanisms underlying the swelling of frog red blood cells (RBC), induced by Pacific (P-CTX-1) and Caribbean (C-CTX-1) ciguatoxins (CTXs), were investigated by measuring the length, width and surface of their elliptic shape. P-CTX-1 (0.5 to 5 nM) and C-CTX-1 (1 mu M) induced RBC swelling within 60 min. The CTXs-induced RBC swelling was blocked by apamin (1 mu M) and by Sr2+ (1 mu M). P-CTX-1-induced RBC swelling was prevented and inhibited by H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one(27 mu M), an inhibitor Of Soluble guanylate cyclase (sGC), and NOS blockade by NG methyl-L-arginine (L-NMA; 10 mu M). Cytochalasin D (cytD, 10 mu M) increased RBC surface and mimicked CTX effect but did not prevent the P-CTX-1-induced L-NMA-sensitive extra increase. Calculations revealed that P-CTX-1 and cytD increase RBC total surface envelop and volume. These data strongly suggest that the molecular mechanisms underlying CTXs-induced RBC swelling involve the NO pathway by an activation of the inducible NOS, leading to sGC activation which modulates intracellular cGMP and regulates L-type Ca2+ channels. The resulting increase in intracellular Ca2+ content, in turn, disrupts the actin cytoskeleton, which causes a water influx and triggers a Ca2+-activated K+ current through SK2 isoform channels. (c) 2005 Elsevier Inc. All rights reserved.

Three classes of starch granule swelling: Influence of surface proteins and lipids

The role of non-carbohydrate surface components of granular starch in determining gelatinisation behaviour has been tested by treatment of native starches with a range of extractants. Resulting washed starches were analysed for (bio)chemical, calorimetric and theological properties. Sodium dodecyl sulphate (SDS) was the most efficient extractant tested, and resulted in major changes to the subsequent theological properties of wheat and maize starches but not other starches. Three classes of starch granule swelling behaviour are identified: (i) rapid swelling (e.g. waxy maize, potato), (ii) slow swelling that can be converted to rapid swelling by extraction of surface proteins and lipids (e.g. wheat, maize), and (iii) limited swelling not affected by protein/lipid extraction (e.g. high amylose maize/potato). Comparison of a range of extractants suggests that all of protein, lipid and amylose are involved in restriction of swelling for wheat or maize starches. Treatment of starches with SDS leads to a residue at comparable (low) levels of SDS for all starches. C-13 NMR analysis shows that this SDS is present as a glucan inclusion complex, even for waxy maize starch. We infer that under the conditions used, glucan inclusion complexation of SDS is equally likely with amylopectin as with amylose. (c) 2006 Elsevier Ltd. All rights reserved.

Oral granular cell tumour of the lip in an adult patient

Oral granular cell tumour is a rare soft tissue tumour of mesenchymal origin. The most frequently affected site in the oral cavity is the tongue, followed by the floor of mouth, and buccal mucosa. In paediatric patients, 25% of cases have been reported to occur in the lip, but this presentation in adults is extremely rare. We report a case of oral granular cell tumour in a 35 year-old female, located in the lower lip. Histopathological examination revealed eosinophilic granular cells which stained positively for S-100 protein; a finding supportive of a neural origin. A history of trauma was elicited in this case, and the lesion was treated with surgical excision.

Liberal Democracy and the Inferior 'Other'Other’: Could the peace liberal democracy promises to bring not extend to ‘Others’?

Advocates of liberal democracy argue that its principles and practices contribute directly to peace (at both inter-state and domestic levels). They rely on ideals such as the rule of law, institutional checks and balances on power, an ethos of tolerance, and free market economics to deliver the liberal peace. Liberals, however, overlook three important features embedded in the construction of liberal democracy which can serve to facilitate political violence: 1) the fixed and thus non-negotiable nature of liberal democracy’s core principles, 2) the inferior manner in which it conceives ‘Other’ social orders that do not share its core principles, and 3) the urge to proselytise Others. Together, these constitutive qualities can facilitate moves by leaders of Other groups to argue that liberal democracy threatens ‘their’ preferred identity, and thus its promised peaceful outcomes can be put in doubt.