Delivery of small interfering ribonucleic acid using lipid nanoparticles prepared with pH-responsive dipeptide-conjugated lipids.

The development of lipid nanoparticles (LNPs) has enabled the clinical application of small interfering ribonucleic acid (siRNA)-based therapies. Accordingly, various unique ionizable lipids have been explored for efficient siRNA delivery. However, safety concerns related to the structure of ionizable lipids have been raised. Here, we developed a pH-responsive dipeptide-conjugated lipid (DPL) for efficient, high safety siRNA delivery. We synthesized a DPL library by varying the dipeptide sequence and established a strong correlation between the knockdown efficiency of the DPL-based LNPs and the dipeptide sequence. The LNPs prepared with a DPL containing arginine (R) and glutamic acid (E) (DPL-ER) exhibited the highest knockdown efficiency. In addition, the DPL-ER-based LNPs with relatively long lipid tails (DPL-ER-C22:C22) exhibited a higher knockdown efficiency than those with short ones (DPL-ER-18:C18). The zeta potential of the DPL-ER-C22:C22-based LNPs increased as the pH decreased from 7.4 (physiological condition) to 5.5 (endosomal condition). Importantly, the DPL-ER-C22:C22-based LNPs exhibited a higher knockdown efficiency than the LNPs prepared using commercially available ionizable lipids. These results suggest that the DPL-based LNPs are safe and efficient siRNA delivery carriers.

Acute posteromedial papillary muscle rupture secondary to aortic valve endocarditis: a case report.

Background: Acute papillary muscle (PM) rupture due to infective involvement has been recognized as a complication of infective endocarditis. However, there is very limited literature describing the rupture of the posteromedial PM in primary aortic valve endocarditis without aortic root abscess. This report highlights the aetiology of the PM rupture in the setting of primary aortic valve endocarditis and the importance of a multidisciplinary approach. Case summary: An 81-year-old man without any heart failure symptoms presented with fever and loss of vision in his left eye. Initial echocardiography revealed moderate aortic valve regurgitation due to a perforated right coronary cusp without aortic root abscess, and his blood cultures were positive for Group G Streptococci. During adequate antibiotic therapy, he developed acute severe mitral regurgitation secondary to posteromedial PM rupture. Following emergent aortic and mitral valve replacement using bioprosthetic valves, he made excellent progress on a 6-week course of intravenous antibiotics. Discussion: The echocardiography and the histological findings suggested that the main cause of PM rupture was most likely a metastatic focus of infection from the aortic valve via a regurgitant jet. Successful treatment of this fatal complication includes early diagnosis and prompt surgical intervention by a multidisciplinary approach.

Multiple Cardiac Calcified Amorphous Tumors.

A 61-year-old woman who underwent hemodialysis presented with heart failure. Echocardiography revealed multiple mobile masses in the left atrium. The masses were excised, and histopathologic examination revealed calcified amorphous tumors. Here, we present several echocardiography images, including 3-dimensional transesophageal echocardiography, demonstrating the revolving masses in the left atrium. (Level of Difficulty: Intermediate.).

Acute Myocardial Infarction Due to Coronary Occlusion Caused by a Metastatic Cardiac Tumor Arising from Squamous Cell Lung Cancer: An Evaluation with Three-dimensional Transthoracic Echocardiography.

A 60-year-old man developed acute myocardial infarction from the total occlusion of the right coronary artery via metastatic squamous lung cancer and was treated with percutaneous coronary intervention (PCI). Computed tomography and transthoracic echocardiography (TTE) revealed a metastatic tumor, and three-dimensional TTE was useful for determining the size and location of the tumor in relation to the coronary artery. Six months after PCI, the patient died, and an autopsy confirmed extensive metastasis to the heart and nearby vessels as detected by three-dimensional TTE. Although rare, lung cancer metastasis to the heart may directly occlude the coronary artery.

Expanded collectin family in bullfrog (Rana catesbeiana): Identification and characterization of plasma collectins.

BLAST searches against databases for the bullfrog (Rana catesbeiana), using the collectin sequence previously identified in tadpoles, revealed the presence of at least 20 members of the collectin gene family. Phylogenetic analysis demonstrated that the bullfrog possesses expanded gene subfamilies encoding mannose-binding lectin (MBL) and pulmonary surfactant-associated protein D (PSAPD). Two collectins, of 20 kDa (PSAPD1) and 25 kDa (PSAPD6), were purified as a mixture from adult bullfrog plasma using affinity chromatography. These collectins were present as an oligomer of ~400 kDa in their native state, and showed Ca2+-dependent carbohydrate binding with different sugar preferences. Affinity-purified collectins showed weak E. coli agglutination and bactericidal activities, compared with those of plasma. Although both PSAPD1 and PSAPD6 genes were predominantly expressed in the liver, PSAPD1 transcripts were abundant in adults whereas PSAPD6 transcripts were abundant in tadpoles. The findings indicate that two gene subfamilies in the collectin family have diverged structurally, functionally and transcriptionally in the bullfrog. Rapid expansion of the collectin family in bullfrogs may reflect the onset of sub-functionalization of the prototype MBL gene towards tetrapod MBL and PSAPDs, and may be one means of natural adaptation in the innate immune system to various pathogens in both aquatic and terrestrial environments.

Modulation of plasma protein expression in bullfrog (Rana catesbeiana) tadpoles during seasonal acclimatization and thermal acclimation.

Biological activities in ectothermic vertebrates depend to a great extent on ambient temperature. Adapting their biological systems to annual or short-term alterations in temperature may play an important role in thermal resistance or overwintering survival. Using SDS-PAGE and western blot, we examined plasma proteins in bullfrog (Rana catesbeiana) tadpoles that were seasonally acclimatized (winter vs. summer) or thermally acclimated (4 °C vs. 21 °C) and identified two season-responsive proteins. The first, transthyretin (TTR), is a plasma thyroid hormone distributor protein that was abundant in summer, and the second is a protein containing C-type lectin-like domain (CTLD) that was abundant in winter and cold acclimation of 4 weeks. Sequence analysis revealed that the C-terminal carbohydrate recognition domain of this CTLD protein (termed collectin X) was highly similar to those of the collectin family members, which participate in complement activation of the innate immune system; however, it lacked most of collagen-like domain. Among the hepatic genes involved in the thyroid system, ttr and dio3 were up-regulated, whereas thra and thrb were down-regulated, in summer acclimatization or warm acclimation. In contrast, the collectin X gene (colectx), as well as colect10 and colect11 in the collectin family involved in the innate immune system, were down-regulated during warm acclimation, although fcn2 in the ficolin family was up-regulated during summer acclimatization and warm acclimation. These findings indicate that seasonal acclimatization and thermal acclimation differentially affect some components of the thyroid and innate immune systems at protein and transcript levels.

Patients With Obesity Exhibit a Plateau Pattern of the Right Ventricular Waveform.

BACKGROUND: Ventricular waveforms are characterized by a dip-and-plateau pattern during diastole owing to an abrupt termination of ventricular filling because of pericardial constraint under conditions such as constrictive pericarditis (CP). However, constrictive hemodynamics is not specifically caused by CP. Therefore, this study aimed to evaluate whether patients with obesity exhibited constrictive hemodynamics. METHODS: Overall, 60 consecutive Japanese patients (mean age, 69.5 years; 45% women) who underwent right heart catheterization at the Japan Community Healthcare Organization Osaka Hospital from July 2016 to September 2018 were examined. Two-dimensional echocardiography was used to measure the epicardial adipose tissue (EAT) in the standard parasternal long-axis view during end-diastole. Because patients who underwent open-heart surgery were highly likely to have CP, they were excluded. RESULTS: Among the 60 patients, 11 (18%) exhibited a plateau pattern of the right ventricular waveform and had a mean EAT value of 4.2 mm, which was significantly higher than that of patients without such a pattern (2.1 mm, P < 0.001). Similarly, the mean body mass index (BMI) values were significantly higher in patients with a plateau pattern than in those without it (27.2 vs. 21.8 kg/m2, P < 0.001). EAT was significantly correlated with the BMI (r = 0.72, P < 0.001). In patients with a plateau pattern, the triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) levels were significantly higher (TG: 150 vs. 100 mg/dL, LDL-C: 121 vs. 95 mg/dL, P < 0.05) and the left atrial diameter (52.8 vs. 44.7 mm, P < 0.01) and left atrial volume index (58.7 vs. 47.6 mL/m2, P < 0.05) were significantly greater than those in the patients without it. The EAT was also significantly correlated with the TG level (r = 0.37, P < 0.01). CONCLUSIONS: Obese patients may present with constrictive hemodynamics, suggesting left ventricular diastolic dysfunction. EAT was significantly correlated with metabolic syndrome components, namely obesity and TG levels.

Interstitial pneumonia suspected during regorafenib administration and exacerbated by subsequent therapy with lenvatinib for unresectable hepatocellular carcinoma.

Recently, three tyrosine kinase inhibitors (TKIs) have become available for treatment of unresectable hepatocellular carcinoma (HCC). We herein report a case of a 59-year-old man with interstitial pneumonia that was suspected during regorafenib administration and was exacerbated by subsequent lenvatinib treatment for advanced HCC. After sorafenib was discontinued due to progressive HCC, regorafenib treatment was started. Progressive HCC was again noted and reticular shadows were suspected in both lower lung fields at 2 months after starting regorafenib administration. Subsequent treatment with lenvatinib obtained a partial response for HCC, but the reticular shadows became marked and dyspnea on effort emerged, followed by hypoxemia and an increased Krebs von den Lungen-6 (KL-6) value. Because we suspected acute interstitial pneumonia, due to these TKIs, intravenous pulse steroid therapy was started immediately after discontinuing lenvatinib. Within 1 week after starting steroid therapy, the patient's respiratory condition and hypoxemia gradually began improving. No previous case of pulmonary interstitial changes that appeared in association with regorafenib administration for HCC and that were exacerbated by subsequent treatment with lenvatinib has been reported. This case emphasizes that it is necessary to observe the patient's respiratory condition and to perform imaging examinations to monitor for adverse events during TKI treatment.

The impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients: retrospective before-after observational study.

PURPOSE: To assess the impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients, we conducted retrospective before-after study in a tertiary teaching hospital. METHODS: We examined all adult patients admitted ICU after an elective operation for head and neck cancer, or esophageal cancer from February 2014 to January 2017. From February 2014 to July 2015, patients were administered hypotonic fluid (sodium; 35 mmol/L) as the National Institute for Health and Care Excellence (NICE) have recommended. From August 2015 to January 2017, patients were administered isotonic fluid (sodium; 140 mmol/L). We defined the incidence of delirium as the primary outcome. The delirium was defined as the Intensive Care Delirium Screening Checklist during the ICU stay ≥ 4. A propensity score-matched model was used to adjust confounders. RESULTS: As postoperative intravenous maintenance fluid, hypotonic fluid was administered to 119 patients and isotonic fluid was administered to 92 patients. Among those total cohorts, the incidence of postoperative delirium in the hypotonic group was 21.8%, which was significantly higher than that (9.8%) in the isotonic group (p = 0.019). After propensity score matching, we selected 77 patients in each group. The incidence of delirium during the ICU stay in the hypotonic group was 26.0%, which was significantly higher than the incidence of 11.7% in the isotonic group (p = 0.023). CONCLUSIONS: In this study, the use of postoperative hypotonic maintenance fluid was associated with a higher risk of postoperative delirium than that when isotonic maintenance fluid was used.

Successful direct-acting antiviral treatment of three patients with genotype 2/1 recombinant hepatitis C virus.

There have been a few reports on the treatment of patients infected with recombinant hepatitis C virus (HCV) genotype 2/1 strains with direct-acting antivirals (DAAs). We experienced three patients, with genotype 2/1 recombinant HCV, treated with DAAs successfully. The first, a 39-year-old man, was infected with recombinant HCV genotype 2a/1b, a rare variant. The sequence of the relapsed virus showed chimeric HCV 2a/1b with the recombinant breakpoint found at nucleotide +49 from the start of the NS3 region. Sofosbuvir plus ribavirin, a regimen recommended for HCV genotype 2, did not lead to a sustained viral response (SVR). Retreatment with grazoprevir plus elbasvir resulted in an SVR. The second case, a 70-year-old woman, was infected with recombinant HCV genotype 2b/1b. DAA therapy with sofosbuvir plus ledipasvir resulted in an SVR. The third case, a 48-year-old woman, was also infected with recombinant HCV genotype 2b/1b. DAA therapy with daclatasvir plus asunaprevir resulted in an SVR. The baseline sequences of the viruses from both the second and third cases showed chimeric HCV 2b/1b with the recombinant breakpoint found at nucleotide +10 from the NS3 start. We report three cases with 2/1 chimeras and discuss the prevalence and response to therapy.

Immunoglobulin G4-related disease of the thickened aortic valve extending to the left ventricular outflow tract causing severe aortic regurgitation and complete atrioventricular block: a case report.

BACKGROUND: Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease characterized by the tumefactive lesions and infiltration of IgG4-positive plasma cells. IgG4-RD has been described in various organs, but rarely the aortic valve. There are only a few reports of aortic stenosis, and none on significant aortic regurgitation. In addition, previous case reports relating to aortic valve lesions led to surgery as a first-line treatment. The effect of steroid treatment has not yet been determined. CASE SUMMARY: A 62-year-old man, receiving steroid therapy, who presented with general malaise, shortness of breath, and bradycardia. He had suspected IgG4-RD because of pancreatitis, lacrimal gland enlargement, and retroperitoneal fibrosis. An examination revealed a thickened aortic valve extending to the left ventricular outflow tract with severe aortic regurgitation and complete atrioventricular block. He received intensive steroid therapy for a suspected IgG4-related aortic valve lesion. The complete atrioventricular block improved, but worsening aortic regurgitation caused congestive heart failure. He required replacement of the aortic valve. A histopathological examination of the excised aortic valve leaflets revealed IgG4-positive lymphoplasmacytic infiltration with fibrotic tissue. The prosthetic valve was functioning well without leakage around the valve at the 1-year follow-up. DISCUSSION: This case highlights the rare possibility that IgG4-RD of the aortic valve also causes significant aortic regurgitation. Conservative treatment with steroids may induce regression of the lesion and contribute to the stability of the prosthetic valve after surgery, but it may also exacerbate heart failure due to the progression of aortic regurgitation in patients with aortic valve lesions.

Constant Current vs. Constant Voltage Systems for Temporal Spinal Cord Stimulation for Intractable Pain.

Although spinal cord stimulation (SCS) is a useful treatment for chronic intractable pain, the optimal method of stimulation has not yet been established. In this prospective, crossover study, we compared the efficacy of using a constant current (CC) system with that of a constant voltage (CV) system for temporal SCS. Twenty patients were enrolled and divided into two groups. For 10 patients, a CV system was applied on Days 1-5, followed by the use of a CC system on Days 6-10. For the other 10 patients, a CC system was applied for the first five days, followed by a CV system for the subsequent five days. We evaluated the alteration of pain intensity using a visual analogue scale (VAS), the area of stimulation, the stability of effect, and patient satisfaction regarding treatment. The pain scores decreased significantly after the start of the SCS. There was no significant difference in the change in VAS between the two systems. The stimulation method used for temporal SCS did not affect the reduction of pain intensity. Patients felt a wider stimulation area by the CC system compared to the CV system.

Effects of antiviral therapy in patients with chronic hepatitis B and cirrhosis.

INTRODUCTION: Hepatitis B virus (HBV) infection is the major cause of cirrhosis worldwide. The ultimate goal of current antiviral treatments for chronic hepatitis B (nucleos(t)ide analogs and interferon-α) is to prevent the development of end-stage liver diseases. Areas covered: We present a review of the current literature on antiviral therapy in patients with chronic hepatitis B and cirrhosis. Medline search was performed to identify relevant literature from 1993 through January of 2017. Expert commentary: One randomized controlled trial and a number of observational studies have shown that nucleos(t)ide analogs can decrease the incidence of hepatocellular carcinoma (HCC) in chronic hepatitis B patients with advanced fibrosis. Data from clinical trials of entecavir and tenofovir have shown that histological improvement and regression of fibrosis can be achieved in the majority of patients with chronic hepatitis B by successful viral suppression. Entecavir and tenofovir are the preferred antiviral agents for treatment of chronic hepatitis B in patients with cirrhosis due to their high antiviral potency and high genetic barrier to resistance. Pegylated interferon-α is another therapeutic option for chronic hepatitis B patients with well-compensated cirrhosis. However, interferon therapy is contraindicated in patients with decompensated cirrhosis, and evidence for reduced HCC is currently insufficient.

Comparison of the incidences of hyponatremia in adult postoperative critically ill patients receiving intravenous maintenance fluids with 140 mmol/L or 35 mmol/L of sodium: retrospective before/after observational study.

PURPOSE: The purpose of this study was to compare the incidences of hyponatremia in adult postoperative critically ill patients receiving isotonic and hypotonic maintenance fluids. METHODS: In this single-center retrospective before/after observational study, we included patients who had undergone an elective operation for esophageal cancer or for head and neck cancer and who received postoperative intensive care for >48 h from August 2014 to July 2016. In those patients, sodium-poor solution (35 mmol/L of sodium; Na35) had been administered as maintenance fluid until July 2015. From August 2015, the protocol for postoperative maintenance fluid was revised to the use of isotonic fluid (140 mmol/L of sodium; Na140). The primary outcome was the incidence of hyponatremia (<135 mmol/L) until the morning of postoperative day (POD) 2. RESULTS: We included 179 patients (Na35: 87 patients, Na140: 92 patients) in the current study. The mean volume of fluid received from ICU admission to POD 2 was not significantly different between the two groups (3291 vs 3337 mL, p = 0.84). The incidence of postoperative hyponatremia was 16.3% (15/92) in the Na140 cohort, which was significantly lower than that of 52.9% (46/87) in the Na35 group (odds ratio = 0.17, 95% confidence interval 0.09-0.35, p < 0.001]. The incidences of hypernatremia, defined as serum sodium concentration >145 mmol/L, were not significantly different between the two groups. CONCLUSION: In this study, the use of intravenous maintenance fluid with 35 mmol/L of sodium was significantly associated with an increased risk of hyponatremia compared to that with 140 mmol/L of sodium in adult postoperative critically ill patients.

A case of delayed respiratory depression caused by accidental subcutaneous opioid infusion.

We report a case of delayed respiratory depression due to accidental subcutaneous opioid infusion. A healthy 33-year-old woman underwent orthopedic surgery under general anesthesia. Before the end of the operation, it was noticed that a part of the opioid infusion had been administered subcutaneously. About 15 min after tracheal extubation, the patient developed respiratory depression and loss of consciousness. The patient recovered with the use of jaw lift together with bag-valve-mask ventilation. We believe that accidental subcutaneous opioid accumulation may have caused the respiratory depression.

The significance of platelet consumption in the development of thrombocytopenia in patients with cirrhosis.

INTRODUCTION: Thrombocytopenia in cirrhosis is mainly explained by accelerated platelet destruction/sequestration because of hypersplenism or by decreased thrombopoietin levels. Excessive platelet consumption because of cirrhosis-related hypercoagulability has also been assumed to be an etiopathologic factor in thrombocytopenia. To clarify whether excessive platelet consumption (eg, venous thrombosis and disseminated intravascular coagulation) contributes to thrombocytopenia in cirrhosis, the following autopsy-based study was performed. METHODS: Ninety-nine autopsies of chronic liver disease (80 cirrhosis and 19 noncirrhosis) were examined retrospectively. Platelet count, weight of spleen and thrombotic complications were checked in autopsy protocols. Megakaryocytes in bone marrow were counted under high-power microscopic view. Univariate and multivariate analyses were performed to evaluate significances of these factors in thrombocytopenia. RESULTS: The platelet count was significantly lower in the cirrhosis cases (88 ± 51 × 10/L) than in the noncirrhosis cases (150 ± 120 × 10/L). The megakaryocyte count was also lower in the cirrhosis cases (1.5 ± 0.6 per high-power field) than in the noncirrhosis cases (1.9 ± 0.5 per high-power field). The weight of the spleen was greater in the cirrhosis cases (264 ± 179 g) than in the noncirrhosis cases (142 ± 82 g). Thrombotic complications had been recorded in 29 cases, whose platelet count (70 ± 41 × 10/L) was lower than that of those without these complications (113 ± 80 × 10/L). Multivariate analysis revealed that these 3 factors (megakaryocyte count, weight of spleen, and thrombotic complications) were independently correlated with the platelet count. CONCLUSIONS: These results suggest that the imbalance of platelet production-destruction/sequestration-consumption contributes to thrombocytopenia in cirrhosis. Excessive platelet consumption cannot be ignored to explain this complex condition, especially in patients with major thrombotic events.

Characterization of the Escherichia coli O157:H7 outbreak strain whose Shiga toxin 2 gene is inactivated by IS1203v insertion.

A total of 12 enterohemorrhagic Escherichia coli (EHEC) O157:H7 strains were isolated during a recent outbreak in a nursery school in Ehime Prefecture, Japan. These isolates were considered to be derived from a common strain when analyzed using an IS-printing method and pulsed-field gel electrophoresis. PCR analysis revealed that the isolates harbor stx1, stx2, eae, and hlyA. However, assessment of the production of the Stx proteins revealed that these isolates produced Stx1 but not Stx2. We determined their stx2 variants such as stx2c and found that the size of the PCR product was much larger than the expected size. Sequencing of the entire stx2 gene revealed that a 1310-bp fragment was inserted into the coding region of the Stx2A subunit and that the sequences of the insert were identical to those of IS1203v. According to the sequences around the insertion site, additional amino acid residues should be attached at the C-terminus of the A subunit, which may hamper the Stx2 complex formation. Finally, this study also suggested that such an insertion may lead to the misinterpretation of results when screening EHEC isolates for virulence genes by PCR.