Evaluating the efficacy of nitazoxanide in uncomplicated amebic liver abscess.

BACKGROUND: Amebic liver abscess is treated successfully with metronidazole or another nitroimidazole drug followed by a luminal amebicide. Metronidazole has long been preferred, but has been associated with several adverse effects including intolerance in certain clinical situations. Mechanisms of metronidazole resistance and mutagenic potential have been described. Effects of the use of drug in pregnant women and infants of lactating women are unknown. Nitazoxanide was proven to be efficacious in treating invasive intestinal amebiasis. Therefore, the present study was undertaken to assess the efficacy and safety of nitazoxanide as compared to metronidazole in patients with uncomplicated amebic liver abscess. METHODS: Patients with clinical and ultrasonography features suggestive of liver abscess, positive amebic serology, and/or anchovy sauce appearance on aspiration of the pus were included in the study and randomized into two parallel treatment groups. Group M received metronidazole, 2-2.5 g/day intravenous (IV), for inpatients, or 2-2.4 g/day oral, for outpatients in three divided doses for 14 days. Group N received nitazoxanide 500 mg BD per oral for 10 days. RESULTS: A total of sixty subjects fulfilling the inclusion criteria were randomized equally into two groups, group M and group N. Number of patients achieving symptomatic clinical response (SCR) was similar in the two groups (80% vs. 76.7%, p = 1.00), though time to achieve symptomatic clinical response was significantly lower in metronidazole group as compared to that in nitazoxanide group. Greater proportion of patients achieved early clinical response (ECR) in metronidazole group as compared to nitazoxanide group. Complete resolution of abscess, at 6 months, was noted in 18 (60%) patients in the M group and 22 (73.3%) patients in the N group (p = 0.273). Metronidazole was associated with significantly greater frequency of adverse effects than nitazoxanide. CONCLUSIONS: This study shows equivalent efficacy of nitazoxanide in uncomplicated amebic liver abscess as compared to metronidazole, with better tolerability and advantage of simultaneous luminal clearance, thus reducing chances of recurrence. TRIAL REGISTRATION: CTRI/2019/01/017249.

Celiac Disease and Portal Hypertension: A Causal Association or Just a Coincidence?

INTRODUCTION: Celiac disease (CD) has been linked to portal hypertension (PHT) of varied etiology, but the causality association has never been proved. We aim to study the prevalence of CD in patients of PHT of different etiology. METHODS: A prospective observational study was conducted from June 2017 to December 2018 involving all the cases of PHT of varied etiology. Consecutive patients of PHT with chronic liver disease (CLD) of defined etiology like ethanol, viral hepatitis (B or C), Budd-Chiari syndrome (BCS), autoimmune-related cirrhosis, and cryptogenic CLD (cCLD) (group A) and those with noncirrhotic PHT (NCPHT), which included noncirrhotic portal fibrosis (NCPF) and extrahepatic portal vein obstruction (EHPVO) (group B), were screened for CD by IgA anti-tTG antibody followed by duodenal biopsy in serology-positive patients. RESULTS: Out of a total of 464 patients, group A constituted 382 patients, CLD related to ethanol (155), cCLD (147), hepatitis B (42), hepatitis C (21), autoimmune (10), and BCS (7), whereas 82 patients were in group B with NCPF (64) and EHPVO (18). Total 29 patients were diagnosed with CD in both groups, 17 in group A (4.5%) and 12 in group B (14.6%). In group A, 13 patients with cCLD, two with HBV-related CLD, one with BCS, and one with autoimmune-related CLD were concomitantly diagnosed as CD. In group B, CD was diagnosed in 12 patients of NCPF (11) and EHPVO (1). Liver histology showed chronic hepatitis in two patients and was normal in three patients. CONCLUSION: CD is common in PHT of different etiology, especially in cCLD, NCPH and autoimmune hepatitis; however, the etiological basis for this association is still to be defined. The likelihood of CD is higher in liver disease than the general population, and these patients should be screened for CD.

Protein-protein interaction studies reveal the Plasmodium falciparum merozoite surface protein-1 region involved in a complex formation that binds to human erythrocytes.

Plasmodium falciparum merozoite surface protein (PfMSP) 1 has been studied extensively as a vaccine candidate antigen. PfMSP-1 undergoes proteolytic processing into four major products, such as p83, p30, p38, and p42, that are associated in the form of non-covalent complex(s) with other MSPs. To delineate MSP1 regions involved in the interaction with other MSPs, here we expressed recombinant proteins (PfMSP-165) encompassing part of p38 and p42 regions and PfMSP-119 PfMSP-165 interacted strongly with PfMSP-3, PfMSP-6, PfMSP-7, and PfMSP-9, whereas PfMSP-119 did not interact with any of these proteins. Since MSP-1 complex binds human erythrocytes, we examined the ability of these proteins to bind human erythrocyte. Among the proteins of MSP-1 complex, PfMSP-6 and PfMSP-9 bound to human erythrocytes. Serological studies showed that PfMSP-165 was frequently recognized by sera from malaria endemic regions, whereas this was not the case for PfMSP-119 In contrast, antibodies against PfMSP-119 showed much higher inhibition of merozoite invasion compared with antibodies against the larger PfMSP-165 fragment. Importantly, anti-PfMSP-119 antibodies recognized both recombinant proteins, PfMSP-119 and PfMSP-165; however, anti-PfMSP-165 antibody failed to recognize the PfMSP-119 protein. Taken together, these results demonstrate that PfMSP-1 sequences upstream of the 19 kDa C-terminal region are involved in molecular interactions with other MSPs, and these sequences may probably serve as a smoke screen to evade antibody response to the membrane-bound C-terminal 19 kDa region.

NMR investigations of amyloid-ß peptide interactions with propofol at clinically relevant concentrations with and without aqueous halothane solution.

Oligomerization of amyloid-ß peptide (Aß) is an important stage in Alzheimer's disease. Recently, it has been shown that in an experimental model, smaller sized anesthetics (e.g., isoflurane, desflurane, etc.) induce Aß oligomerization. Using state-of-the-art solution nuclear magnetic resonance, spectroscopic studies on Aß interaction with propofol indicated that propofol does not interact with the G29, A30, and I31 residues of Aß peptide at a clinically relevant concentration (0.083 mM), and no Aß oligomerization was observed after 69 days. However, Aß oligomerization was observed when treated with propofol (clinically relevant concentration) coadministered with aqueous halothane solution. Furthermore, dose dependence studies at various propofol concentrations (0.32 mM, 2.07 mM, and 53.4 mM) indicate the effect of propofol concentration on Aß oligomerization revealing the hydrophobic nature of interactions between propofol with these critical residues (G29, A30, and I31). These experimental findings reaffirm that smaller molecular sized anesthetics (e.g., halothane) do play a leading role in Aß oligomerization.