Peritoneal tuberculosis in Qatar: a five-year hospital-based study from 2005 to 2009

There is limited information about peritoneal tuberculosis in Qatar. This retrospective study aimed to review our experience with peritoneal tuberculosis in patients admitted to Hamad general hospital over a period of 5 years, from 2005 to 2009, with emphasis on presentation, investigation, diagnosis and therapeutic outcome. Fifty-four patients with peritoneal tuberculosis identified during the study period were included. The mean age of them was 31.85 years and 96.3% (52/54) of them were non-Qataris with male predominance. The main symptoms and signs at the time of presentation were abdominal pain and ascites respectively. Underlying diseases were described in 24% (13/54) and history of contact with tuberculous cases was present in 31.5% (17/54) of patients. Tuberculin test was positive in 66.7% (36/54). The ascitic fluid smear showed acid fast bacilli in 2% (1/53), and culture was positive in 39.6% (21/53) of cases. Laparoscopically obtained peritoneal biopsy showed caseating granulomas in 93% (40/43) and mycobacteria were identified by acid fast staining and culture in 58.5% (24/41) and 98% (40/41) of the tested specimens respectively. Most of the patients (84%; 37/44) who had completed their therapy in Qatar improved with antituberculosis therapy, and only one patient died. In conclusion, the clinical features and the imaging findings of the disease were non-specific. A high index of suspicion is essential for early diagnosis. Culture of ascitic fluid delayed the diagnosis in clinically suspected cases, whereas laparoscopically guided peritoneal biopsy provided rapid and correct diagnosis. A Six-month course with antituberculous therapy was effective and improved the outcome.     

Bamboo leaf-based carbon dots for efficient tumor imaging and therapy

In this study, carbon dots synthesized from bamboo leaf cellulose were used simultaneously as a staining agent and for doxorubicin delivery to target cancer cells. Owing to their nontoxic properties, the production of carbon dots from bamboo leaves is a green approach involving optimized application of bamboo tree waste. For multifunctional applications, the carbon dots were modified with 4-carboxybenzylboronic acid and doxorubicin to improve target specificity and drug delivery to HeLa tumor cells. The resulting modified carbon dots were characterized using different analytical techniques, which showed that they were biocompatible, nontoxic, and highly stable over a wide range of pH values and at high ionic strengths. Furthermore, in vitro confocal microscopy studies demonstrated their blue fluorescence and cellular pathway for entering HeLa cells via folate receptor-mediated endocytosis. Cell viability data and flow cytometry results also confirmed the selective uptake of the carbon dots by HeLa cells, which significantly enhanced cell cytotoxicity.

In this study, carbon dots synthesized from bamboo leaf cellulose were used simultaneously as a staining agent and for doxorubicin delivery to target cancer cells.     

Association of calcium channel blocker use with clinical outcome of COVID-19: A meta-analysis

AimsThis meta-analysis aims to analyze the association of calcium channel blocker (CCB) use with COVID-19 clinical outcomes.MethodsPubMed, ProQuest, Science Direct, Scopus, and medRxiv databases were searched systematically in a limited period. The primary outcome was mortality.ResultsA total of 119,298 patients from 31 eligible studies were included. Pooled analysis of the random-effect model revealed CCB was not associated with reduced mortality (OR = 1.21 [95%CI: 0.98–1.49], p = 0.08). Interestingly, subgroup analysis in hypertensive patients revealed significantly reduced mortality (OR = 0.69 [95%CI: 0.52–0.91], p = 0.009).ConclusionCCB usage was not associated with the outcome of COVID-19. However, CCB was associated with a decreased mortality rate in hypertensive COVID-19 patients.     

The differential expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappaB ligand (RANKL) in human osteoarthritic subchondral bone osteoblasts is an indicator of the metabolic state of these disease cells

OBJECTIVE: We previously reported that human OA subchondral bone osteoblasts could be discriminated into two subpopulations identified by their levels of endogenous production (low [L] or high [H]) of PGE(2). Here, we investigated the OPG and RANKL expression levels, the histologic analysis of the subchondral bone as well as the osteoclast differentiation effect of osteoblasts on normal and both OA subpopulations (L and H), and further examined on the L OA osteoblasts the modulation of bone remodelling factors on the OPG and RANKL levels, as well as on the resorption activity. METHODS: Gene expression was determined using real-time PCR, PGE2 and OPG levels by specific ELISA, and membranous RANKL by flow cytometry. Histological observation of the subchondral bone was performed on human knee specimens. Osteoclast differentiation and formation was assayed by using the pre-osteoclastic cell line RAW 264.7. OPG and RANKL modulation on L OA osteoblasts was monitored following treatment with osteotropic factors, and the resorption activity was studied by the co-culture of differentiated PBMC/osteoblasts. RESULTS: Human OA subchondral bone osteoblasts expressed less OPG than normal. Compared to normal, RANKL gene expression levels were increased in L OA and decreased in H OA cells. The OPG/RANKL mRNA ratio was significantly diminished in L OA compared to normal or H OA (p<0.02, p<0.03), and markedly increased in H OA compared to normal. Inhibition of endogenous PGE(2) levels by indomethacin markedly decreased the ratio of OPG/RANKL on the H OA. In contrast to H OA osteoblasts, L OA cells induced a significantly higher level of osteoclast differentiation and formation (p<0.05).Histological analysis showed a reduced subchondral bone on the L OA and an increased bone mass on the H OA compared to normal. Treatment of L OA osteoblasts with osteotropic factors revealed that the OPG/RANKL mRNA expression ratio was significantly reduced by vitamin D(3) and significantly increased by TNF-alpha, PTH and PGE(2), while IL-1Beta demonstrated no effect. OPG protein levels showed similar profiles. No true effect was noted on membranous RANKL upon treatment with IL-1Beta, PGE(2) and PTH, but a significant increase was observed with vitamin D3 and TNF-alpha. The resorption activity of the L OA cells was significantly inhibited by all treatments except IL-1Beta, with maximum effect observed with vitamin D(3) and PGE(2). CONCLUSION: OPG and RANKL levels, and consequently the OPG/RANKL ratio, differed according to human OA subchondral bone osteoblast classification; it is decreased in L and increased in H OA. These findings, in addition to those showing that L OA osteoblasts have a reduced subchondral bone mass and induce a higher level of osteoclast differentiation, strongly suggest that the metabolic state of the L OA osteoblasts favours bone resorption.     

Recurrent Primary Cardiac Lymphoma on Aortic Valve Allograft: Implications for Therapy

Primary malignant cardiac lymphomas associated with grafts are extremely rare: to our knowledge, only 6 cases of prosthesis-associated B-cell lymphoma have been reported. Ours is the first report of recurrent diffuse large B-cell lymphoma associated with aortic valve allografts.We treated a 60-year-old man who presented in early 2007 with aortic valve endocarditis. He underwent aortic valve replacement with an allograft; the resected native valve showed active endocarditis without tumor. In January 2011, the patient underwent repeat aortic valve replacement because of symptomatic aortic regurgitation. The explanted valve specimen displayed diffuse large B-cell lymphoma. In September 2011, the patient presented with fever and a mass around the aortic valve. He died in January 2012. On autopsy, the explanted replacement valve displayed recurrent diffuse large B-cell lymphoma. The recurrent lymphoma on a new graft leads us to believe that this tumor is more aggressive than had been thought. We propose early systemic chemotherapy, in addition to tumor resection, for the possibility of a better prognosis. We discuss our patient''s case and review the relevant medical literature.