Design Improvement of the Jellyfish Valve for Long-term Use in Artificial Hearts

In a previous communication, we reported a leaflet fracture in a Jellyfish valve that was incorporated into a blood pump, after a 312-day animal implant duration. Subsequent finite element analysis revealed that the fracture location was consistent with an area of maximum strain concentration. Therefore, the aim of this study was to improve the durability in the light of these findings. Based on the engineering analysis results, a new valve seat having a concentric ring of 0.5mm width, located at a radius of 7.0 mm, was designed and fabricated. Accelerated fatigue tests, conducted under the conditions recommended by ISO 5840, demonstrated that the durability of this new prototype was extended by a factor of 10, as compared to the original valve. Moreover, further finite element analysis indicated that the maximum equivalent elastic strain of the proposed new valve was reduced by 52.3% as compared to the original valve. Accordingly, it has been confirmed that the modified Jellyfish valve is suitable for use in long-term artificial hearts.

Predictability of Intraocular Lens Power Calculation for Cataract with Keratoconus: A Multicenter Study

This study was aimed to assess the predictability of intraocular lens (IOL) power calculation after cataract surgery for keratoconus. We retrospectively reviewed the clinical charts of 102 eyes of 71 consecutive keratoconic patients who developed cataract. We determined manifest spherical equivalent, prediction errors, and absolute errors, 1 month postoperatively. The achieved refraction was significantly more hyperopic than the targeted refraction, when keratometric readings were used (p = 0.001). At 1 month, 36% and 63% of the eyes were within ±0.5 and ±1.0 D, respectively, of the targeted correction. We found a significant correlation between the prediction error and the mean keratometry (Pearson correlation coefficient r =−0.545, p < 0.001). No vision-threatening complications occurred in any case. The achieved refraction was significantly more myopic than the targeted refraction, when total corneal refractive power was used (p = 0.013). Phacoemulsification with IOL implantation appeared to be safe and effective, and the accuracy was also good in mild keratoconus, but not in severe keratoconus. It should be noted that that a large amount of hyperopic shift occurred especially in advanced keratoconic patients, when keratometric readings were used for IOL power calculation, and that a slight, but significant, myopic shift occurred, when total corneal refractive power was used.

Oxidative stress serves as a key checkpoint for IL-33 release by airway epithelium

BACKGROUND

Interleukin (IL)-33 is implicated in the pathophysiology of asthma and allergic diseases. However, our knowledge is limited regarding how IL-33 release is controlled. The transcription factor nuclear factor-erythroid-2-related factor 2 (Nrf2) plays a key role in antioxidant response regulation.

OBJECTIVE

The goal of this project was to investigate the role of cellular oxidative stress in controlling IL-33 release in airway epithelium.

METHODS

Complementary approaches were used that included human bronchial epithelial cells and mouse models of airway type-2 immunity that were exposed to fungus Alternaria extract. The clinically available Nrf2 activator 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid methyl ester (CDDO-Me) was used to evaluate the role of Nrf2-induced antioxidant molecules.

RESULTS

Human bronchial epithelial cells produced reactive oxygen species (ROS) when they were exposed to Alternaria extract. ROS scavengers, such as glutathione (GSH) and N-acetyl cysteine, prevented extracellular secretion of ATP and increases in intracellular calcium concentrations that precede IL-33 release. Administration of CDDO-Me to mice enhanced expression of a number of antioxidant molecules in the lungs and elevated lung levels of endogenous GSH. Importantly, CDDO-Me treatment reduced allergen-induced ATP secretion and IL-33 release by airway epithelial cells in vitro and protected mice from IL-33 release and asthma-like pathological changes in the lungs.

CONCLUSIONS

The balance between oxidative stress and antioxidant responses plays a key role in controlling IL-33 release in airway epithelium. The therapeutic potential of Nrf2 activators needs to be considered for asthma and allergic airway diseases.

IL-33 mediates reactive eosinophilopoiesis in response to airborne allergen exposure

BACKGROUND

Exposure to aeroallergens induces eosinophilic airway inflammation in patients with asthma and allergic airway diseases. The circulating number of eosinophils in peripheral blood is relatively small, leading us to hypothesize that bone marrow needs to be engaged quickly to meet the demands of the tissues.

METHODS

To investigate the communication between the lungs and bone marrow, we used acute allergen exposure and airway inflammation models in mice. Gene-deficient mice and cytokine reporter mice as well as in vitro cell culture models were used to dissect the mechanisms.

RESULTS

Naïve BALB/c mice produced increased numbers of eosinophil precursors and mature eosinophils in the bone marrow when their airways were exposed to a common fungal allergen, Alternaria alternata. Expression of IL-5 and IL-33 increased rapidly in the lungs, but not in the bone marrow. Sera from allergen-exposed mice promoted eosinophilopoiesis in bone marrow cells from naïve mice, which was blocked by anti-IL-5 antibody. Mice deficient in the IL-33 receptor ST2 (i.e., Il1rl1(-/-) mice) were unable to increase their serum levels of IL-5 and allergen-induced eosinophilopoiesis in the bone marrow after allergen exposure. Finally, group 2 innate lymphoid cells (ILC2s) in the lungs showed robust expression of IL-5 after Alternaria exposure.

CONCLUSIONS

These finding suggests that lung IL-33, through innate activation of ILC2s and their production of IL-5, plays a key role in promoting acute reactive eosinophilopoiesis in the bone marrow when naïve animals are exposed to airborne allergens. Therefore, bone marrow eosinophilopoiesis may be affected by atmospheric environmental conditions.

Screening for Malnutrition in Community Dwelling Older Japanese: Preliminary Development and Evaluation of the Japanese Nutritional Risk Screening Tool (NRST)

BACKGROUND

Early and effective screening for age-related malnutrition is an essential part of providing optimal nutritional care to older populations.

OBJECTIVE

This study was performed to evaluate the adaptation of the original SCREEN II questionnaire (Seniors in the Community: Risk Evaluation for Eating and Nutrition, version II) for use in Japan by examining its measurement properties and ability to predict nutritional risk and sarcopenia in community-dwelling older Japanese people. The ultimate objective of this preliminary validation study is to develop a license granted full Japanese version of the SCREEN II.

PARTICIPANTS

The measurement properties and predictive validity of the NRST were examined in this cross-sectional study of 1921 community-dwelling older Japanese people.

MEASUREMENTS

Assessments included medical history, and anthropometric and serum albumin measurements. Questions on dietary habits that corresponded to the original SCREEN II were applied to Nutritional Risk Screening Tool (NRST) scoring system. Nutritional risk was assessed by the Geriatric Nutrition Risk Index (GNRI) and the short form of the Mini-Nutritional Assessment (MNA-SF). Sarcopenia was diagnosed according to the criteria of the European Working Group on Sarcopenia in Older People.

RESULTS

The nutritional risk prevalences determined by the GNRI and MNA-SF were 5.6% and 34.7%, respectively. The prevalence of sarcopenia was 13.3%. Mean NRST scores were significantly lower in the nutritionally at-risk than in the well-nourished groups. Concurrent validity analysis showed significant correlations between NRST scores and both nutritional risk parameters (GNRI or MNA-SF) and sarcopenia. The areas under the receiver operating characteristic curves (AUC) of NRST for the prediction of nutritional risk were 0.635 and 0.584 as assessed by GNRI and MNA-SF, respectively. AUCs for the prediction of sarcopenia were 0.602 (NRST), 0.655 (age-integrated NRST), and 0.676 (age and BMI-integrated NRST).

CONCLUSIONS

These results indicate that the NRST is a promising screening tool for the prediction of malnutrition and sarcopenia in community-dwelling older Japanese people. Further development of a full Japanese version of the SCREEN II is indicated.

Predictability of Intraocular Lens Power Calculation After Simultaneous Pterygium Excision and Cataract Surgery

This study was aimed to assess the predictability of intraocular lens (IOL) power calculation after simultaneous pterygium excision and phacoemulsification with IOL implantation. We retrospectively reviewed the clinical charts of 60 eyes of 60 consecutive patients (mean age ± standard deviation, 73.5 ± 7.0 years) who developed pterygium and cataract. We determined visual acuity (logMAR), manifest spherical equivalent, manifest astigmatism, corneal astigmatism, and mean keratometry, preoperatively and 3 months postoperatively. Corrected visual acuity was significantly improved from 0.19 ± 0.20 preoperatively to -0.06 ± 0.07 postoperatively (P < 0.001, Wilcoxon signed-rank test). Uncorrected visual acuity was also significantly improved from 0.62 ± 0.33 preoperatively to 0.31 ± 0.32 postoperatively (P < 0.001). At 3 months, 48% and 82% of the eyes were within ± 0.5 and ± 1.0 D, respectively, of the targeted correction. We found significant correlations of the prediction errors with the changes in the mean keratometry (Spearman signed-rank test, r = -0.535, P < 0.001) and with the pterygium size (r = -0.378, P = 0.033). Simultaneous pterygium and cataract surgery was safe and effective, and the accuracy was moderately predictable. However, it should be noted that a significant myopic shift occurred postoperatively, possibly resulting from the steepening of the cornea after pterygium removal, especially when the size of pterygium was large.

Demographics of patients having cataract surgery after laser in situ keratomileusis

PURPOSE

To retrospectively assess the demographics of patients having cataract surgery in eyes with previous laser in situ keratomileusis (LASIK).

SETTING

Department of Ophthalmology, Kitasato University, Kanagawa, and Sanno Hospital, Tokyo, Japan.

DESIGN

Retrospective case series.

METHODS

This study evaluated eyes of consecutive patients scheduled for cataract surgery after previous LASIK (Group 1). The control groups comprised eyes with axial lengths (ALs) matched with ALS in Group 1 (Group 2) and all eyes scheduled for cataract surgery (Group 3). Assessed were age, sex, corrected distance visual acuity, manifest refraction, keratometry (K) readings, corneal astigmatism, and corneal higher-order aberrations (HOAs).

RESULTS

Group 1 comprised 40 eyes of 40 patients; Group 2, 606 eyes of 606 patients; and Group 3, 3642 eyes of 3642 patients. The mean age at cataract surgery of patients in Group 1 was 54.6 years ± 8.1 (SD), which was significantly younger than in Group 2 (by approximately 10 years) and Group 3 (by approximately 15 years) (P < .001, Student t test). In Group 1, 70.0% of patients were men, a significantly higher percentage than in Groups 2 and 3 (P < .05, Fisher exact test). The rate of corneal HOAs was significantly higher in Group 1 than in Groups 2 and 3 (P < .05, Student t test). There were no significant differences in other demographics except in K readings.

CONCLUSION

A long AL and an increase in corneal HOAs might contribute to a tendency for cataract surgery to be performed earlier in eyes in which LASIK has been performed.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Basophil infiltration in eosinophilic oesophagitis and proton pump inhibitor-responsive oesophageal eosinophilia

BACKGROUND

The features of proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) are similar to those of eosinophilic oesophagitis (EoE), but PPI-REE demonstrates symptomatic and histological responses to PPI therapy. Several studies have shown that basophils play a crucial role in the pathogenesis of allergic diseases.

AIM

To identify and compare basophil infiltration in the oesophageal epithelium in patients with EoE, PPI-REE, gastroesophageal reflux disease (GERD) and normal oesophagus (controls).

METHODS

Biopsy specimens from 43 patients, including 12 with EoE, 11 with PPI-REE, 10 with GERD and 10 normal oesophagus, were analysed. Immunohistochemistry was performed to quantify the number of basophils and mast cells in the oesophageal epithelium. Double immunofluorescence staining for thymic stromal lymphopoietin (TSLP) and basophils was performed. Patients with EoE were treated with swallowed fluticasone.

RESULTS

There were no differences in clinical, endoscopic or histological features between patients with EoE and PPI-REE. There were more basophils and mast cells in patients with EoE and PPI-REE than in patients with GERD and control subjects. Basophil infiltration of the oesophageal epithelium in patients with EoE was higher than that in patients with PPI-REE (3.6 ± 2.8 per high power field vs. 1.2 ± 0.9 per high power field respectively; P = 0.02); however, there was no significant difference in mast cell infiltration between the two groups. TSLP was highly expressed in the oesophageal epithelium in areas infiltrated by basophils. Steroid therapy significantly decreased intraepithelial basophils in patients with EoE.

CONCLUSION

Basophils may play an important role in the pathogenesis of eosinophilic oesophagitis.

Identification of a high-risk group for low-dose aspirin-induced gastropathy by measuring serum pepsinogen in H. pylori-infected subjects

BACKGROUND

We recently demonstrated in humans that the extent of low-dose aspirin (LDA)-induced gastropathy was directly related to the individual gastric acid secretion level. We also established reliable cutoff serum pepsinogen (PG) values to predict gastric acid secretion status. In this study, we investigated the clinical usefulness of measuring the serum pepsinogen values for identifying a high-risk group for gastric mucosal injury among chronic LDA users.

METHODS

One hundred long-term LDA users were enrolled in this analysis. Serum from each subject was subjected to determination of H. pylori status and measurement of pepsinogen values. According to our recent report, a PG I value ≥ 50 ng/mL was defined as estimated hyperchlorhydria in H. pylori-negative subjects, while a PG I/II ≥ 3.3 was defined as estimated hyperchlorhydria in H. pylori-positive subjects. The grade of gastric mucosal injury was assessed endoscopically, and multiple logistic regression analyses were used to estimate the risk.

RESULTS

Estimated hyperchlorhydria was a strong independent risk for intensive gastric mucosal injury with an OR (95% CI): 34.0 (4.5-259) and for gastric ulcer with an OR (95% CI): 10.2 (1.8-58.3) in H. pylori-positive subjects, while it was not a significant risk in H. pylori-negative subjects. The association persisted even after excluding those with conventional risks for LDA-gastropathy such as ulcer histories.

CONCLUSION

Using simple serum measurement of H. pylori antibody and pepsinogen concentrations, an extremely high-risk group for LDA-induced gastropathy could be extracted, and these patients should become a therapeutic target for prevention of LDA-induced gastropathy.