Timing of bowel preparation and colonoscopy on colonic preparation and polyp detection: a single endoscopist study

Poster abstract no. 607link_to_OA_fulltextAsian Pacific Digestive Week (APDW) 2011, SUNTEC Singapore International Convention & Exhibition Centre, Singapore, 1-4 October 2011. In Journal of Gastroenterology and Hepatology, 2011, v. 26 n. Suppl. 5, p. 124, abstract no. 60

Fine needle aspiration cytology of lymph node with metastatic undifferentiated carcinoma and granulomatous (sarcoid-like) reaction [1]

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A 33-year-old chinese woman with a left frontal tumor

Rhabdoid tumor cells are typically observed in atypical teratoid/rhabdoid tumor (AT/RT) but may also be seen in meningioma, glioma, melanoma, rhabdomyosarcoma and metastatic carcinoma. We present an astroblastoma with unusual rhabdoid features which is rarely described in the English literature. Apart from the rhabdoid tumor cells, all the histopathological features typical for astroblastoma are present in this case. These features include pseudopapillary arrangement, astroblastic pseudorosettes, perivascular hyalinization and calcifications, absence of fibrillary background and a pushing tumor border. The tumor cells display a multilineage immunohistochemical profile. In addition, diffuse and strong membranous and cytoplasmic dot-like pattern is appreciated with epithelial membrane antigen (EMA). The diagnosis of astroblastoma is also well supported by the age of presentation, anatomical location and radiological features of the tumor. We believe that on top of the above-mentioned unusual tumors with rhabdoid cells, astroblastoma should also be considered in the list of differential diagnosis. © 2009 The Authors.link_to_subscribed_fulltex

Effect of mycophenolate mofetil on severity of nephritis and nitric oxide production in lupus-prone MRL/lpr mice

Mycophenolate mofetil (MMF), an immunosuppressive drug commonly used in organ transplantation, is increasingly being used to treat autoimmune diseases including systemic lupus erythematosus (SLE). Excessive production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of lupus nephritis. We evaluated the effect of MMF on the severity of nephritis and the production of NO in lupus-prone MRL/1pr mice. Eight-week-old female MRL/1pr mice (n = 20) were treated with MMF (100mg/kg/day) by oral gavage for 12 weeks. Control mice (n = 20) received vehicle on the same schedule. The mice were killed after 12 weeks of treatment. Treatment with MMF significantly decreased the amount of proteinuria, prolonged survival and reduced the histological severity of glomerulonephritis. Urinary nitrite/nitrate excretion in the MMF-treated mice was significantly reduced during the first 8 weeks of treatment. However, by the end of the 12 weeks' treatment period, there was no significant difference between vehicle and MMF-treated mice in terms of urinary nitrite/nitrate excretion, intra-renal production of NO, expression of iNOS protein and induction of iNOS mRNA. We conclude that MMF is effective in attenuating the severity of nephritis in MRL/1pr mice. The beneficial effects of MMF on lupus nephritis during the early phase of the disease might be partly attributed to the inhibition of NO production. The inhibitory effect of MMF on NO production diminishes as the disease progresses. MMF probably has additional, as yet undefined mode of actions to fully account for its beneficial effects on lupus nephritis.link_to_subscribed_fulltex

Effect of mycophenolate mofetil on nitric oxide production and inducible nitric oxide synthase gene expression during renal ischaemia-reperfusion injury

Background. Recent animal data suggest that inducible nitric oxide synthase (iNOS) derived nitric oxide (NO) plays an important role in the pathogenesis of renal ischaemia-reperfusion injury (IRI) and that inhibition of iNOS ameliorates IRI. Mycophenolate mofetil (MMF), a lymphocyte selective anti-proliferative agent, has been shown to inhibit NO production in vitro. The aim of this study is to evaluate the effect of MMF on NO production and iNOS gene expression in vivo during renal IRI. Methods. Renal IRI was induced by clamping the left renal pedicle of male BALB/c mice for 30 min, followed by 15 min of reperfusion. The mice received placebo or MMF at 40, 80 or 120 mg/kg/day by oral gavage for 5 days before the operation. Sham-operated mice served as the operation control. The amount of NO produced and the level of iNOS gene expression in the kidney tissue during IRI was assessed by spin trapping electron paramagnetic resonance (EPR) spectroscopy and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) respectively. Results. In the sham-operated kidneys, only low levels of NO and iNOS mRNA were detected. In mice with renal IRI, the amount of NO detected was significantly increased, which was reduced in a dose dependent fashion by pre-treatment with MMF. Pre-treatment with MMF also substantially reduced iNOS gene expression in the kidney tissue. Conclusions. We conclude that pre-treatment with MMF inhibits the production of NO and the induction of iNOS gene expression in the kidney during IRI. These results suggest that MMF might have the potential to ameliorate renal IRI.link_to_subscribed_fulltex

Altered expression of aquaporin-2 in human explants with chronic renal allograft dysfunction

OBJECTIVE: To investigate the distribution of aquaporins, a recently discovered family of transmembrane water channels, in human renal explants, with specific reference to chronic renal allograft dysfunction (CRAD). MATERIALS AND METHODS: Immunohistochemistry for aquaporin-1 and -2 was used in 11 explants, of which five had clinically and histologically confirmed CRAD. Controls were taken from the six explants unaffected by CRAD and from histologically normal areas of six kidneys excised for renal tumours. RESULTS: In the renal tumour control group, aquaporin-1 immunoreactivity was detected in the glomerular endothelium, Bowman's capsule, the proximal convoluted tubules and the thin limb of the loop of Henle, whereas immunoreactivity for aquaporin-2 was detected in the collecting ducts only. Of the expiants without CRAD, where architecture was preserved, immunoreactivity for aquaporin-1 and -2 was the same as in the renal tumour controls. In the two explants with no CRAD and loss of collecting ducts, there was no aquaporin-2 immunoreactivity. In five explants with CRAD, immunoreactivity for aquaporin-2 was decreased or absent from the medulla to the cortex. The apparent decreased immunoreactivity of aquaporin-1 in this group was secondary to a decrease in the number of viable proximal tubules. CONCLUSION: There was less aquaporin-2 immunoreactivity in human renal explants diagnosed with CRAD, starting from the medullary region. In explants with no CRAD and viable collecting ducts, or in normal controls, aquaporin-2 immunoreactivity remained unchanged. Aquaporins might be useful as markers for CRAD. © 2005 BJU INTERNATIONAL.link_to_subscribed_fulltex

Fine needle aspiration cytology of invasive micropapillary carcinoma of the breast

Aim: To determine the pathognomonic diagnostic cytological features of invasive micropapillary carcinoma of the breast which is a poor prognostic subtype of infiltrating ductal carcinoma. Methods: A series of 20 histologically proven tumours were reviewed retrospectively to evaluate the various cytological features, including tumour morules, isolated malignant cells, staghorn epithelial structures, mucinous background and apocrine metaplasia. Results: Tumour morules formation and isolated malignant cells were the two most reliable and constant cytological features, being present in 75% (15/20 cases) of cases. Staghorn epithelial structures were present in 35% (7 cases). Mucinous background (2 cases, 10%) and apocrine metaplasia (4 cases, 20%) of the tumour cells were seen in a few cases only and did not appear very helpful. Conclusion: Tumour morules formation, isolated malignant cells and staghorn epithelial structures are the most reliable cytological features, and the presence of these should raise suspicion of invasive micropapillary carcinoma. © 2007 Royal College of Pathologists of Australasia.link_to_subscribed_fulltex