Correction to: The characteristics of gastrointestinal symptoms in patients with severe COVID-19: a systematic review and meta-analysis

Journal of Gastroenterology - A correction to this paper has been published: https://doi.org/10.1007/s00535-021-01786-z     

Incidence of hepatocellular carcinoma in HCV-infected patients with normal alanine aminotransferase levels categorized by Japanese treatment guidelines

Background

This study was conducted to evaluate Japanese treatment guidelines for patients with chronic hepatitis C virus (HCV) infection and normal alanine aminotransferase (N-ALT) levels from the viewpoint of the incidence of hepatocellular carcinoma (HCC).

Methods

Four groups of patients with chronic HCV infection treated with pegylated interferon (Peg-IFN) plus ribavirin, and classified according to the N-ALT guidelines, were examined for HCC incidence: group A (n = 353), ALT ≤30 IU/L and platelet (PLT) ≥15 × 10⁴/mm³; group B (n = 123), ALT ≤30 IU/L and PLT <15 × 10⁴/mm³; group C (n = 233), 30 < ALT ≤ 40 IU/L and PLT ≥15 × 10⁴/mm³; and group D (n = 100), 30 < ALT ≤ 40 IU/L and PLT <15 × 10⁴/mm³. The mean observation period was 36.2 ± 16.5 months

Results

In groups A and C, the HCC incidence was low even in patients with non-response (NR) (cumulative rates at 3 years, 0.0 and 2.9 %, respectively). In groups B and D, 14.5 and 5.3 % of NR patients had developed HCC at 3 years, but none of the patients with sustained virologic response (SVR) or relapse had developed HCC. In group B, no patients with mild fibrosis developed HCC irrespective of the antiviral effect of the treatment. Among patients with PLT <15 × 10⁴/mm³ (group B plus group D), the HCC incidence was significantly lower in patients with SVR and relapse than in NR patients (p < 0.001, p = 0.021, respectively).

Conclusion

These results suggest that N-ALT patients with PLT <15 × 10⁴/mm³ could be candidates for early antiviral therapy.     

Clinical prediction rule to distinguish pelvic inflammatory disease from acute appendicitis in women of childbearing age

Objective

We aimed to develop a clinical prediction rule to distinguish pelvic inflammatory disease (PID) from acute appendicitis in women of childbearing age.

Methods

We reviewed medical records over a 4-year period of female patients of childbearing age who had presented with abdominal pain at an urban emergency department and had either appendicitis (n = 109) or PID (n = 72). A prediction rule was developed by use of recursive partitioning based on significant factors for the discrimination.

Results

The significant factors to favor PID over appendicitis were (1) no migration of pain (odds ratio [OR], 4.2; 95% confidence interval [CI], 1.5-11.5), (2) bilateral abdominal tenderness (OR, 16.7; 95% CI, 5.3-50.0), and (3) absence of nausea and vomiting (OR, 8.4; 95% CI, 2.8-24.8). The prediction rule could rule out appendicitis from PID with sensitivity of 99% (95% CI, 94-100%) when classified as a low-risk group by the following factors: (1) no migration of pain, (2) bilateral abdominal tenderness, and (3) no nausea and vomiting.

Conclusion

We developed a prediction rule for childbearing-aged women presenting with acute abdominal pain to distinguish acute appendicitis from PID based on 3 simple, clinical features: migration of pain, bilateral abdominal tenderness, and nausea and vomiting. Prospective validation is needed in other settings.     

Synthesis of self-assembled nucleobases and their anhydrous proton conductivity

We synthesized self-assembled nucleobases (SANs), such as 1-dodecylthymine (DOT) or 9-dodecyladenine (DOA), in which the nucleobase is immobilized on a long alkyl chain. The thermal stability of the SAN was increased by mixing with the acidic surfactant mono-dodecyl phosphate (MDP). Additionally, the SAN–MDP composite material showed proton conductivity of 4.62 × 10⁻⁴ S cm⁻¹ at 160 °C under anhydrous conditions. Additionally, the activation energy of the proton conduction was approximately 0.2 eV and this value was one order of magnitude higher than that of a typical humidified perfluorinated membrane, in which the proton can be moved by vehicle molecules, such as water molecules. In contrast, when the nucleobase without the immobilization of a long alkyl chain was mixed with MDP, the proton conductivity of these composite materials was two orders of magnitude less than that of the SAN–MDP composite. Therefore, we measured the XRD spectra of the SAN–MDP composite material. As a result, the SAN–MDP composite material showed a self-assembled structure with a two-dimensional proton conducting pathway, such as a lamellar structure, and that the anhydrous proton conduction was related to the interaction between the nucleobase of the SAN and the phosphate group of MDP. Consequently, the self-assembled nucleobase derivatives have the potential for use as novel anhydrous proton conductors with a two-dimensional proton conducting pathway.

We synthesized the proton conductive self-assembled nucleobase, such as 1-dodecylthymine and 9-dodecyladenine, in which the nucleobase is immobilized on a long alkyl chain.     

Influences of environmental noise level and respiration rate on the accuracy of acoustic respiration rate monitoring

We tested the hypothesis that the environmental noise generated by a forced-air warming system reduces the monitoring accuracy of acoustic respiration rate (RRa). Noise levels were adjusted to 45–55, 56–65, 66–75, and 76–85 dB. Healthy participants breathed at set respiration rates (RRset) of 6, 12, and 30/min. Under each noise level at each RRset, the respiration rates by manual counting (RRm) and RRa were recorded. Any appearance of the alarm display on the RRa monitor was also recorded. Each RRm of all participants agreed with each RRset at each noise level. At 45–55 dB noise, the RRa of 13, 17, and 17 participants agreed with RRset of 6, 12, and 30/min, respectively. The RRa of 14, 17, and 16 participants at 56–65 dB noise, agreed with RRset of 6, 12, and 30/min, respectively. At 66–75 dB noise, the RRa of 9, 15, and 16 participants agreed with RRset of 6, 12, and 30/min, respectively. The RRa of one, nine, and nine participants at 76–85 dB noise agreed with RRset of 6, 12, and 30/min, respectively, which was significantly less than the other noise levels (P?<?0.05). Overall, 72.9% of alarm displays highlighted incorrect values of RRa. In a noisy situation involving the operation of a forced-air warming system, the acoustic respiration monitoring should be used carefully especially in patients with a low respiration rate.     

Nationwide survey for patients with acute-on-chronic liver failure occurring between 2017 and 2019 and diagnosed according to proposed Japanese criteria

Journal of Gastroenterology - The significance of the 2018 Japanese diagnostic criteria for acute-on-chronic liver failure (ACLF) has not yet been evaluated. A nationwide survey was performed for...     

Nanoanalytical analysis of bisphosphonate-driven alterations of microcalcifications using a 3D hydrogel system and in vivo mouse model

Vascular calcification predicts atherosclerotic plaque rupture and cardiovascular events. Retrospective studies of women taking bisphosphonates (BiPs), a proposed therapy for vascular calcification, showed that BiPs paradoxically increased morbidity in patients with prior acute cardiovascular events but decreased mortality in event-free patients. Calcifying extracellular vesicles (EVs), released by cells within atherosclerotic plaques, aggregate and nucleate calcification. We hypothesized that BiPs block EV aggregation and modify existing mineral growth, potentially altering microcalcification morphology and the risk of plaque rupture. Three-dimensional (3D) collagen hydrogels incubated with calcifying EVs were used to mimic fibrous cap calcification in vitro, while an ApoE^−/− mouse was used as a model of atherosclerosis in vivo. EV aggregation and formation of stress-inducing microcalcifications was imaged via scanning electron microscopy (SEM) and atomic force microscopy (AFM). In both models, BiP (ibandronate) treatment resulted in time-dependent changes in microcalcification size and mineral morphology, dependent on whether BiP treatment was initiated before or after the expected onset of microcalcification formation. Following BiP treatment at any time, microcalcifications formed in vitro were predicted to have an associated threefold decrease in fibrous cap tensile stress compared to untreated controls, estimated using finite element analysis (FEA). These findings support our hypothesis that BiPs alter EV-driven calcification. The study also confirmed that our 3D hydrogel is a viable platform to study EV-mediated mineral nucleation and evaluate potential therapies for cardiovascular calcification.

Atherosclerotic plaque rupture is the leading cause of myocardial infarction and stroke (1, 2). Studies assessing the correlation between calcium scores and cardiovascular events have demonstrated a predictive power that is superior to and independent from that of lipid scores (3, 4). Additionally, clinical imaging studies have revealed that the risk of plaque rupture is further heightened by the presence of small, “spotty” calcifications, or microcalcifications (5, 6), and cardiovascular risk is inversely correlated with the size of calcific deposits, quantified as a calcium density score (7). Indeed, computational modeling has demonstrated that, while large calcifications can reinforce the fibrous cap (8), microcalcifications (typically 5 to 15 μm in diameter) uniquely mediate an increase in mechanical stress of the relatively soft, collagen-rich fibrous cap (9–12).Histologic studies have revealed the presence of cell-derived vesicles within calcifying atherosclerotic lesions (13–16). The inflammatory environment of the atherosclerotic lesion can induce vascular smooth muscle cells (vSMCs) to take on an osteochondrogenic phenotype and release calcifying extracellular vesicles (EVs) (17–19). Macrophages have also been shown to release procalcifying vesicles (20, 21). Thus, just as bone formation is hypothesized to be an active, cell-driven process (22, 23), mediated by calcifying matrix vesicles, atheroma-associated calcification may similarly be initiated by the production and aggregation of calcifying EVs (11, 20, 24–28).One proposed strategy for halting pathologic calcification has been the use of bisphosphonates (BiPs). BiPs are analogs of pyrophosphate (29), a naturally occurring compound derived in vivo from adenosine triphosphate (ATP) (30). Pyrophosphate binds to calcium phosphate and inhibits calcification via physicochemical mechanisms, namely, by blocking calcium and phosphate ions from forming crystals, preventing crystal aggregation, and preventing mineral transformation from amorphous calcium phosphate to hydroxyapatite (29). BiPs were identified as pyrophosphate analogs that, unlike pyrophosphate itself, resist enzymatic hydrolysis. A second, distinct property of BiPs is the ability to inhibit bone resorption via biological activity directed against osteoclasts following osteoclast endocytosis of the BiP molecule adsorbed to the surface of bone (29, 31). First-generation, or nonnitrogen-containing BiPs, are incorporated into nonhydrolyzable ATP analogs, and induce osteoclast apoptosis by limiting ATP-dependent enzymes. In contrast, nitrogen-containing BiPs inhibit farnesyl pyrophosphate synthetase and thereby induce osteoclast apoptosis (31).In vivo animal investigations have been performed to explore the potential for BiPs to inhibit cardiovascular calcification. Studies of first-generation BiPs revealed that the doses required to inhibit cardiovascular calcification also critically compromised normal bone mineralization (29, 32). However, newer, nitrogen-containing BiPs effectively arrested cardiovascular calcification in animal models at doses that did not compromise bone formation (32). Further, while it has been proposed that BiP treatment modifies cardiovascular calcification via its impact on bone-regulated circulating calcium and phosphate levels, a study in uremic rats demonstrated that BiP treatment inhibited medial aortic calcification with no significant change in plasma calcium and phosphate levels (33). The same study demonstrated that BiP treatment inhibited calcification of explanted rat aortas, indicating that BiPs can act directly on vascular tissue, independent of bone metabolism (33).Retrospective clinical data examining the effect of BiP therapy on cardiovascular calcification has demonstrated conflicting findings and intriguing paradoxes. In women with chronic kidney disease, BiP therapy decreased the mortality rate for patients without a prior history of cardiovascular disease (34), but for those patients with a history of prior cardiovascular events, BiP therapy was associated with an increased mortality rate (35). In another study, BiP therapy correlated with a lower rate of cardiovascular calcification in older patients (>65 y), but a greater rate in younger patients (<65 y) (36). These clinical findings motivated our study, in which we sought to further understand how BiP therapy impacts cardiovascular outcomes. Given that cardiovascular calcification, and especially the presence of microcalcification, is a strong and independent risk factor for adverse cardiac events, and BiPs are prescribed to modulate pathologies of mineralization, we hypothesize that BiPs modulate cardiovascular outcomes by altering the dynamics of cardiovascular calcification.EVs are smaller than the resolution limits of traditional microscopy techniques, hindering studies into the mechanisms of calcification nucleation and growth. We previously developed an in vitro collagen hydrogel platform that allowed the visualization of calcific mineral development mediated by EVs isolated from vSMCs (24). Using superresolution microscopy, confocal, and electron microscopy techniques, we showed that calcification requires the accumulation of EVs that aggregate and merge to build mineral. Collagen serves as a scaffold that promotes associations between EVs that spread into interfibrillar spaces. The resultant mineral that forms within the collagen hydrogel appears spectroscopically similar to microcalcifications in human tissues and allows the study of these structures on the time scale of 1 wk. In this study, we utilized this three-dimensional (3D) acellular platform to examine the direct effect of ibandronate, a nitrogen-containing BiP, on the EV-directed nucleation and growth of microcalcifications, a process that cannot be isolated from cellular and tissue-level mechanisms in a more complex, in vivo system. In parallel, we utilized a mouse model of atherosclerosis to assess the effect of ibandronate therapy on plaque-associated calcification, comparing mineral morphologies between the in vitro and in vivo samples. We hypothesize that BiPs block EV aggregation and modify existing mineral growth, potentially altering microcalcification morphology and the risk of plaque rupture. Understanding the EV-specific action of BiPs is imperative both to develop anticalcific therapeutics targeting EV mineralization and to understand one potential mechanism driving the cardiovascular impact of BiPs used in clinical settings.