Radiologic screening for lung cancer

Lung cancer is the leading cause of cancer death. A number of screening trials have been carried out over the past two decades and have failed to demonstrate a reduction of lung cancer-related mortality. Recent advances in new forms of technology--spiral low-dose CT--have resuscitated interest in screening programs. Preliminary results are promising but the outstanding question is whether the magnitude of improvement is sufficient to affect a measurable reduction in lung cancer mortality?     

Non-alcoholic Steatohepatitis (NASH) and Hepatocellular Carcinoma

Non-alcoholic fatty liver disease (NAFLD) is characterized by an excessive accumulation of fatty acids and triglycerides within the cytoplasm of the hepatocytes of non-alcohol users. The natural history varies according to the initial histological diagnosis. A current consideration is that cryptogenic cirrhosis may be representative of a late stage of non-alcoholic steatohepatitis (NASH), which has lost its features of necroinflammatory activity and steatosis in up to 80% of patients. Since NASH is able to progress to cirrhosis, hepatocellular carcinoma (HCC) development may be an end-stage of this disease. We report below two clinical cases of patients diagnosed with NASH who developed HCC. The relationship between NAFLD and HCC is reviewed.     

Life-threatening gastrointestinal bleeding related to the treatment of strongyloidiasis hyperinfection in an immunocompromised patient

The clinical course and sequel of the life-threatening gastrointestinal (GI) bleeding during the treatment of strongyloides helmintic hyperinfection induced by immunosuppression in a patient with multiple myeloma is presented. A 55-year old male patient was diagnosed with strongyloides infection with stool analysis and intestinal biopsy shortly after his combined chemotherapy for myeloma. He was commenced on albendazole anthelmintic therapy. However, after initiation of the treatment he suffered life-threatening GI bleeding. Repeated endoscopies, including intraoperative enteroscopy, concluded to diffuse multifocal intestinal bleeding. The patient required huge amounts of red blood cells and plasma transfusions and correction of haemostasis with recombinant activated factor VII. Abdominal aorto-angiography showed numerous microaneurysms ("berry aneurysms") in the superior and inferior mesenteric arteries' territories. While the biopsy taken prior to the treatment with albendazole did not show evidence of vasculitis, the biopsy taken after initiation of therapy revealed leukoclastic aggregations around the vessels which was also consistent with vasculitis. These findings suggest that--in addition to direct destruction of the mucosa-vasculitis could be an important additive factor to the massive GI bleeding during the anthelmintic treatment. This might result from substances released by the worms that have been killed with anthelmintic drugs. Current guidelines advise steroids to be tapered and stopped in case of systematic parasitic infections as they reduce immunity and precipitate parasitic hyperinfection. In our pinion, steroid therapy might be of value in the management of strongyloides hyperinfection related vasculitis--in addition to the specific anthelmintic treatment. Indeed, steroid therapy of vasculitis with other means of supportive care yielded in sequel of the bleeding and in recovery of the patient.     

Cryopreservation based on freezing protocols for the long-term storage of microencapsulated myoblasts

One important challenge in biomedicine is the ability to cryogenically preserve not only cells, but also tissue-engineered constructs. In the present paper, alginate-poly-l-lysine-alginate (APA) microcapsules containing erythropoietin (Epo)-secreting C₂C₁₂ myoblasts were elaborated, characterized and tested both in vitro and in vivo. Dimethylsulfoxide (DMSO) was selected as cryoprotectant to evaluate the maintenance of physiological activity of cryopreserved microencapsulated myoblasts employing procedures based on freezing protocols up to a 45-day cryopreservation period. High chemical resistance of the cryopreserved microcapsules was observed using 10% DMSO as cryoprotectant following a standard slow-cooling procedure. Although a 42% reduction in Epo release from the microencapsulated cells was observed in comparison with the non-cryopreserved group, the in vivo biocompatibility and functionality of the encapsulated cells subcutaneously implanted in Balb/c mice was corroborated by high and sustained hematocrit levels over 194 days and lacking immunosuppressive protocols. No major host reaction was observed. Based on the results obtained in our study, a slow-cooling protocol using 10% DMSO as cryoprotectant (confirmed for cryopreservation periods up to 45 days) might be considered a suitable therapeutic strategy if the long-term storage of microencapsulated cells, such as C₂C₁₂ myoblasts is pretended.     

Association of increased phagocytic NADPH oxidase-dependent superoxide production with diminished nitric oxide generation in essential hypertension

OBJECTIVE: Oxidative stress has been implicated in the pathogenesis of hypertension and its complications through alterations in nitric oxide (NO) metabolism. This study was designed to investigate whether a relationship exists between phagocytic nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent superoxide anion (*O2-) production and NO generation in patients with essential hypertension. METHODS: Superoxide production was assayed by chemiluminescence under baseline and stimulated conditions on mononuclear cells obtained from hypertensives (n=51) and normotensives (n=43). NO production was evaluated by determining serum NO metabolites, nitrate plus nitrite (NOx). RESULTS: Although there were no differences in baseline *O2- production between normotensives and hypertensives, the *O2- production in phorbol myristate acetate (PMA)-stimulated mononuclear cells was increased (P <0.05) in hypertensives compared with normotensives. The PMA-induced *O2- production was completely abolished by apocynin, a specific inhibitor of NADPH oxidase. Moreover, stimulation of *O2- production by angiotensin II and endothelin-1 was higher (P <0.05) in cells from hypertensives than in cells from normotensives. In addition, diminished (P <0.001) serum NOx was detected in hypertensives compared with normotensives. Interestingly, an inverse correlation (r=0.493, P <0.01) was found between *O2- production and NOx in hypertensives. CONCLUSIONS: Generation of *O2- mainly dependent on NADPH oxidase is abnormally enhanced in stimulated mononuclear cells from hypertensives. It is suggested that this alteration could be involved in the diminished NO production observed in these patients.     

Uptake and Distribution of Trace Elements in Dominant Mangrove Plants of the Indian Sundarban Wetland

Absorption, accumulation and translocation of 12 trace elements in nine dominant mangrove plants in the Indian Sundarban Wetland revealed both organ-specific and site-specific characteristics. An overall enrichment of elements was recorded in rhizosediment, exceeding the prescribed effects range-low (ER-L) of consensus based sediment quality guidelines (SQGs) for Cu and Pb. Avicennia officinalis, A. alba, Ceriops decandra and Excoecaria agallocha exhibited unique potential for accumulating Al, Cd, Co, Cr, Cu, Ni, Mn and Zn and could be considered efficient accumulators. Maximum element accumulation in trunk bark (As 6.16, Cr 49.9, Co 2.67, Cu 91.00 and Zn 85.5 mg kg^?1) and root/pneumatophore (Al 1000 and Fe 2430 mg kg^?1) was recorded. Maximum bioconcentration factor (6.23) in A. officinalis and translocation factor (17.5 for Mn) in C. decandra distinguished their phytoremediation capacity. These halophytes could be used for trace element phytoremediation in stressed sites of Sundarban.