Malignant peripheral nerve sheath tumour presenting as a pneumothorax

Malignant peripheral nerve sheath tumours are rare and aggressive soft-tissue sarcomas of ectomesenchymal origin. These tumours commonly occur in patients with neurofibromatosis Type 1 with a cumulative lifetime risk of 10%. The vast majority of cases present with clinical evidence of a soft-tissue mass with or without features of nerve irritation and loss of function arising from the lesion of origin. The primary presentation of a malignant peripheral nerve sheath tumour with a pneumothorax in the absence of widespread metastatic disease in a patient with no medical or family history of neurofibromatosis has never been reported in the literature. We present a unique case of a systemically well 34-year-old male who presented with clinical evidence of a right-sided pneumothorax. The chest radiograph identified the right-sided pneumothorax and revealed an apical pleural mass that was confirmed by intravenous contrast-enhanced CT of the thorax. The patient was referred for video-assisted thorascopic surgical pleurodesis and biopsy of the lesion. Histopathology analyses confirmed the diagnosis of malignant peripheral nerve sheath tumour. To the best of our knowledge, no such case reports have been published in the literature. A diagnosis of malignant peripheral nerve sheath tumour should be considered as one of the rarer possibilities in patients presenting with pneumothoraces in association with apical pleural lesions.

Endovascular repair of a spontaneous ilio-iliac fistula presenting as pulmonary embolism

Spontaneous rupture of a common iliac artery aneurysm into the common iliac vein is a rare phenomenon. We report the case of a 68 year old man admitted with acute cardiac failure and massive pulmonary embolism as a complication of a spontaneous ilio-iliac fistula, secondary to aneurysmal rupture. The aneurysm was successfully excluded using an aorto-uni-iliac stent graft. No complications were noted at 9 months follow-up. Arteriovenous fistulae should be considered in patients with aortic or iliac aneurysms who develop a pulmonary embolism or symptoms of venous congestion. Endovascular repair of these pathologies is a feasible therapeutic option; however long term results remain unknown.

Isolation and synthesis of flavonols and comparison of their antioxidant activity

Phytochemical investigation of the leaves of Astragalus beckari yielded four flavonol aglycones, namely kaempferol, quercetin, 5-deoxy kaempferol and fisitin. These isolated compounds were then synthesised in the laboratory using the Algar-Flyn-Oyamad reaction. Antioxidant activity of both the isolated and synthesised flavonoids was compared using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay method. The isolated flavonoids were found to be more active.

Diagnosis and management of ureterovaginal fistula in a resource-constrained setting: experience at a district hospital in northern Nigeria

During 2007 we were invited at different times to review and manage four women with ureterovaginal fistula following caesarean section performed in different rural hospitals. We describe our experience of a simple technique of diagnosis and management of these indigent patients in a resource-constrained hospital. The condition was diagnosed by the three-swab test in all four patients, and abdominopelvic ultrasound was employed to help find the ureter involved. Transvesical ureteral implantation with a stent was carried out. Stent was removed after 2 weeks. All four patients were dry. Amidst the complexity of and sophistication of modern health care, it is important to remind ourselves of the common occurrence of this distressing condition following caesarean section and the use of a well known simple diagnostic technique and subsequent management in resource-poor communities.

Is there any justification for the routine histological examination of straightforward cholecystectomy specimens?

INTRODUCTION

Gall bladder carcinoma is a rare malignancy that carries a very poor prognosis. Laparoscopic cholecystectomy (LC) is established as the gold-standard treatment for symptomatic gall stones. The aim of the study was to assess the incidence of gall bladder carcinoma and the possibility of reducing the routine histological examination of gall bladder specimens.

PATIENTS AND METHODS

Pathology laboratory data of gall bladder specimens over a period of 5 years (June 2000 to July 2005) were analysed retrospectively. The case notes were retrieved in all cases of malignancies.

RESULTS

The total number of specimens was 1452. Four (0.27%) cases of primary gall bladder carcinoma, one case of primary B-cell lymphoma and one secondary carcinoma were detected as well as one case of intra-epithelial neoplasia. Operative notes revealed that there was a high index of suspicion of malignancy in all cases. Of the 4 primary gall bladder carcinomas, 3 were stage T2 and one T4. Pre-operative ultrasound suspected carcinoma in only one case but a thickened gall bladder wall was noted in all cases.

CONCLUSIONS

All cases of gall bladder carcinoma were suspected pre-operatively or intra-operatively. Histological examination did not alter the management or outcome in any of the cases. We suggest that selectively sending specimens for histopathological examination would result in reduced demands on the histopathology department without compromising patient safety.

Hydrodynamics beyond Navier-Stokes: exact solution to the lattice Boltzmann hierarchy

The exact solution to the hierarchy of nonlinear lattice Boltzmann (LB) kinetic equations in the stationary planar Couette flow is found at nonvanishing Knudsen numbers. A new method of solving LB kinetic equations which combines the method of moments with boundary conditions for populations enables us to derive closed-form solutions for all higher-order moments. A convergence of results suggests that the LB hierarchy with larger velocity sets is the novel way to approximate kinetic theory.

Studies on kinetics and thermostability of a novel acid invertase from Fusarium solani

The present investigation deals with purification and thermal characterization of an acid invertase produced by Fusarium solani in submerged culture. The maximum enzyme activity (9.90 U mL(-1)) was achieved after 96 h of cultivation at pH 5.0 and 30 degrees C in a basal medium containing molasses (2%) as the carbon and energy source supplemented with 1% peptone. Invertase was purified by ammonium sulfate fractionation and column chromatography on DEAE-cellulose and Sephadex G-200. The purified enzyme was proven to be homogeneous by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The molecular mass of the enzyme was 65 kDa. The optimum pH and temperature for activity were 2.6 and 50 degrees C, respectively. The Km value for sucrose was 3.57 mM with an activation energy of 4.056 kJ mol(-1). Enthalpies of activation (DeltaH) were decreased while entropies (DeltaS) of activation increased at higher temperatures. The effects of alpha-chymotrypsin and 4 M urea were tetraphasic with periodic gain and loss of enzyme activity. A possible explanation for the thermal inactivation of invertase at higher temperatures is also discussed.