Phase wavefront perturbation calculation model for spectroscopic refractive index matching of hybrid materials.

A low-cost flexible spectroscopic refractive index matching (SRIM) material with bandpass filtering properties without incidence angle and polarization dependence by randomly dispersing inorganic C a F 2 particles in organic polydimethylsiloxane (PDMS) materials was proposed in our previous study. Since the micron size of the dispersed particles is much larger than the visible wavelength, the calculation based on the commonly used finite-difference time-domain (FDTD) method to simulate light propagation through the SRIM material is too bulky; however, on the other hand, the light tracing method based on Monte Carlo theory in our previous study cannot adequately explain the process. Therefore, a novel approximate calculation model, to the best of our knowledge, based on phase wavefront perturbation is proposed that can well explain the propagation of light through this SRIM sample material and can also be used to approximate the soft scattering of light through composite materials with small refractive index differences, such as translucent ceramics. The model simplifies the complex superposition of wavefront phase disturbances and the calculation of scattered light propagation in space. The scattered and nonscattered light ratios; the light intensity distribution after transmission through the spectroscopic material; and the influence of absorption attenuation of the PDMS organic material on the spectroscopic performance are also considered. The simulation results based on the model are in great agreement with the experimental results. This work is important to further improve the performance of SRIM materials.

Preoperative Sarcopenia Assessment Using Pectoralis Muscle Mass Indicated Poor Mid-term Cardiac Surgery Prognosis.

BACKGROUND: Many studies have defined sarcopenia based on psoas muscle mass using abdominal computed tomography (CT). We hypothesized that sarcopenia can be assessed by measuring pectoralis muscle mass on chest CT and aimed to examine its relationship with the postoperative prognosis of cardiac surgery. METHODS: This retrospective study included 189 patients who underwent cardiac surgery via median sternotomy between July 2020 and June 2022. We excluded patients <70 years old, urgent/emergent cases, no chest CT within 90 days before surgery, and cases in which evaluation of the pectoralis muscle was impossible with CT. The pectoralis muscle area (PMA) was measured using a preoperative chest CT. The sarcopenia cut-off value was defined as the lowest sex-specific tertile in PMA at the level of the 4th thoracic vertebrae. RESULTS: Eighty patients were included. The lower tertile were classified as the sarcopenia group (SG) (n = 26) and the rest as the non-sarcopenia group (NSG) (n = 54). In the SG, 1-year survival was significantly worse than that in NSG (NSG: 92.7% vs. SG: 54.9%, p < 0.0001). In the multivariate model, sarcopenia was an independent risk factor for mid-term all-cause death (hazard ratio, 4.89; 95% confidence interval: 1.14-21.0, p = 0.033). CONCLUSION: Preoperative sarcopenia defined using PMA was associated with poor mid-term survival after elective cardiac surgery via median sternotomy. The pectoralis muscle mass observed through a chest CT could be used for preoperative risk scoring in older patients undergoing cardiac surgery.

Effect of Poly(Vinyl Alcohol) Concentration and Chain Length on Polymer Nanogel Formation in Aqueous Dispersion Polymerization.

Nanotechnology has attracted increasing interest in various research fields for fabricating functional nanomaterials. In this study, we investigated the effect of poly(vinyl alcohol) (PVA) addition on the formation and thermoresponsive properties of poly(N-isopropyl acrylamide)-based nanogels in aqueous dispersion polymerizations. During dispersion polymerization, PVA appears to play three roles: (i) it bridges the generated polymer chains during polymerization, (ii) it stabilizes the formed polymer nanogels, and (iii) it regulates the thermoresponsive properties of the polymer nanogels. By regulating the bridging effect of PVA via changing the PVA concentration and chain length, the size of the obtained polymer gel particles was maintained in the nanometer range. Furthermore, we found that the clouding-point temperature increased when using low-molecular weight PVA. We believe that the knowledge gained in this study regarding the effect of PVA concentration and chain length on nanogel formation will aid in the future fabrication of functional polymer nanogels.

[A Case of Breast Cancer Complicated by Fibrous Dysplasia That Was Difficult to Differentiate from Bone Metastasis].

A 58-year-old woman with HER2-negative hormone-sensitive postmenopausal breast cancer underwent preoperative bone scintigraphy and CT to search for distant metastasis. Bone metastasis was suspected in the spinous process of the seventh cervical vertebra. MRI revealed a mass that was hypointense on T1- and T2-weighted images and hyperintense on diffusion- weighted images, with intense contrast enhancement, indicating bone metastasis at cT1N0M1, Stage Ⅳ(M: OSS). The patient underwent partial mastectomy and sentinel lymph node biopsy. The postoperative diagnosis was pT2N0cM1, Stage Ⅳ, with the status of bone metastasis being key to staging. PET-CT showed uptake in the spinous process of the seventh cervical vertebra but no other metastatic findings. However, solitary bone metastasis to the cervical spinous process is atypical. CT-guided needle biopsy confirmed benign fibrous dysplasia, and the final diagnosis was breast cancer at pT2N0M0, Stage ⅡA. Fibrous dysplasia is characterized by impaired osteogenesis leading to fibroplasia and commonly occurs in the skull, jaw bones, ribs, and limbs. Solitary fibrous dysplasia in the cervical spinous process is rare. The lesion was asymptomatic and pathologically benign, requiring no treatment. The patient underwent postoperative radiation therapy for the conserved breast and is followed up with endocrine therapy.

Clinical Outcomes After Percutaneous Coronary Intervention in East Asian Patients　- 30-Month Results of the PENDULUM Registry.

BACKGROUND: The 12-month results of the PENDULUM registry showed that after implantation of second-generation drug-eluting stents (DES), high P2Y12reaction unit (HPR) were independently associated with ischemic but not bleeding events.Methods and Results: This study analyzed cumulative incidences of major adverse cardiac and cerebrovascular events (MACCE) and major bleeding (Bleeding Academic Research Consortium type 3 and 5) at 30 months after index percutaneous coronary intervention (PCI) (primary endpoints). Of 6,422 patients undergoing PCI with DES, 5,796 completed the 30-month follow up. The continuation rate of dual antiplatelet therapy decreased to 59.3% at 12 months and 26.4% at 30 months. At 30 months, the cumulative incidence of MACCE increased linearly and reached 9.5% (95% confidence interval 8.8-10.2) and that of major bleeding had the inflection point at 12 months and was 4.4% (3.9-5.0). MACCE and bleeding events were higher in HPR patients (unadjusted P value). After covariate adjustment, P2Y12reactivity units measured immediately after index PCI was not an independent risk factor for MACCE or major bleeding at 30 months. CONCLUSIONS: MACCE consistently increased after 12 months post-PCI, whereas the increase in major bleeding events slowed down after 12 months in Japanese PCI patients in a real-world clinical setting. HPR patients had increased MACCE and bleeding complications, but HPR was not an independent risk factor of events at 30 months.

Early P2Y12 Inhibitor Single Antiplatelet Therapy for High-Bleeding Risk Patients After Stenting　- PENDULUM Mono 24-Month Analysis.

BACKGROUND: In PENDULUM mono, Japanese patients with high bleeding risk (HBR) received short-term dual antiplatelet therapy (DAPT) followed by single antiplatelet therapy (SAPT) with prasugrel after percutaneous coronary intervention (PCI). One-year data from PENDULUM mono showed better outcomes with prasugrel monotherapy after short-term DAPT compared with matched patients in the PENDULUM registry with longer DAPT durations according to guidelines at that time. This study presents 2-year results.Methods and Results: We compared 24-month data from PENDULUM mono (n=1,107; de-escalation strategy group) and the PENDULUM registry (n=2,273; conventional strategy group); both were multicenter, non-interventional, prospective registry studies, using the inverse probability of treatment weighting (IPTW) method. In the PENDULUM mono group, the cumulative incidence of clinically relevant bleeding (CRB) at 24 months post-PCI (primary endpoint) was 6.8%, and that of major adverse cardiac and cerebrovascular events (MACCE) was 8.9%. After IPTW adjustment, the cumulative incidence of CRB was 5.8% and 7.2% in PENDULUM mono and the PENDULUM registry, respectively (hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.57-1.04; P=0.086), and that of MACCE was 8.0% and 9.5%, respectively (HR 0.77; 95% CI 0.59-1.01; P=0.061). CONCLUSIONS: Japanese PCI patients with HBR prescribed prasugrel SAPT after short-term DAPT had a lower ischemic event risk than those prescribed long-term DAPT, and this was particularly relevant for ischemic events after 1 year.

Ischemic and Bleeding Events in PENDULUM Patients With High Bleeding Risk and High Platelet Reactivity.

BACKGROUND: The balance between thrombotic and bleeding risk is of great concern in high bleeding risk (HBR) patients. This study evaluated the relationship between perioperative antiplatelet reactivity and thrombotic and bleeding events in patients at HBR undergoing percutaneous coronary intervention (PCI).Methods and Results: In this post hoc analysis of the PENDULUM (Platelet rEactivity in patieNts with DrUg eLUting stent and balancing risk of bleeding and ischeMic event) registry, patients undergoing PCI were categorized as HBR or non-HBR, and stratified as having high platelet reactivity (HPR; P2Y12reaction unit [PRU] >208) or non-HPR (PRU ≤208). Cumulative incidences of cardiovascular and cerebrovascular events (Journal of the American College of Cardiology expert definitions) and bleeding events (Bleeding Academic Research Consortium criteria) were assessed 12 months after index PCI. The incidence of ischemic and bleeding events was ~3-fold higher in HBR vs. non-HBR patients. Thrombotic/ischemic events were significantly more common in the HPR subgroup in HBR patients (hazard ratio [HR]: 1.59; 95% confidence interval [CI]: 1.11-2.28; P=0.012), but there was no difference in non-HBR patients. After adjustment for covariates, HPR in HBR patients remained an independent factor for thrombotic and ischemic events (HR: 1.69; 95% CI: 1.13-2.54; P=0.011), but not for bleeding events (HR: 1.56; 95% CI: 0.78-3.11; P=0.210). CONCLUSIONS: Maintaining adequate PRU levels during PCI is an important factor in improving clinical outcomes, especially for HBR patients.

Relationship between platelet aggregation and stroke risk after percutaneous coronary intervention: a PENDULUM analysis.

In patients undergoing percutaneous coronary intervention (PCI) with a stent, high on-treatment platelet reactivity may be associated with an increased risk of stroke. This post hoc analysis of the PENDULUM registry compared the risk of post-PCI stroke according to on-treatment P2Y12 reaction unit (PRU) values. Patients aged ≥ 20 years who underwent PCI were stratified by baseline PRU (at 12 and 48 h post-PCI) as either high (HPR, > 208), optimal (OPR, > 85 to ≤ 208), or low on-treatment platelet reactivity (LPR, ≤ 85). The incidences of non-fatal ischemic and non-ischemic stroke through to 12 months post-PCI were recorded. Almost all enrolled patients (6102/6267 [97.4%]) had a risk factor for ischemic stroke, and most were receiving dual antiplatelet therapy. Of the 5906 patients with PRU data (HPR, n = 2227; OPR, n = 3002; LPR, n = 677), 47 had a non-fatal stroke post-PCI (cumulative incidence: 0.68%, ischemic; 0.18%, non-ischemic stroke). Patients with a non-fatal ischemic stroke event had statistically significantly higher post-PCI PRU values versus those without an event (P = 0.037). The incidence of non-fatal non-ischemic stroke was not related to PRU value. When the patients were stratified by PRU ≤ 153 versus > 153 at 12-48 h post-PCI, a significant difference was observed in the cumulative incidence of non-fatal stroke at 12 months (P = 0.044). We found that patients with ischemic stroke tended to have higher PRU values at 12-48 h after PCI versus those without ischemic stroke.Clinical trial registration: UMIN000020332.

Increase in pediatric complicated appendicitis during the COVID-19 pandemic: a multi-center retrospective study.

PURPOSE: An increase in the incidence of pediatric complicated appendicitis (CA) during the COVID-19 pandemic has been reported in many countries. We investigated how the pandemic has affected Japan. METHODS: We retrospectively reviewed children of ≤ 15 years old treated for acute appendicitis across 5 medical centers during the pandemic period (January to October in 2020), with the pre-pandemic period (January to October in 2017 to 2019) evaluated as a historical control. The incidence of CA and disease characteristics were then compared between the periods. RESULTS: The total number of patients was 55 in 2020 and 192 in 2017-2019. In all centers, the incidence of acute pediatric CA in the pandemic period significantly increased compared to the pre-pandemic period (18.2% vs. 32.7%, p = 0.02). On limiting our evaluation to the 3 institutions with reductions in patient numbers, the incidence of CA increased (16.3% vs. 37.9%, p = 0.01), and the duration of pre-operative symptoms was prolonged (1.3% vs. 1.7 days, p = 0.03). There were no significant differences in the age, sex, white blood cell count, C-reactive protein, or body temperature. No cases were diagnosed with SARS-CoV-2. CONCLUSIONS: The incidence of acute pediatric CA increased during the pandemic period. This may be related to an extended duration of symptoms due to individuals fearing contracting COVID-19 while visiting a hospital.

Programed Thermoresponsive Polymers with Cleavage-Induced Phase Transition.

A new programed upper critical solution temperature-type thermoresponsive polymer was developed using water-soluble anionic polymer conjugates derived from polyallylamine and phthalic acid with cleavage-induced phase transition property. Intrinsic charge inversion from anion to cation of the polymer side chain is induced through a side chain cleavage reaction in acidic aqueous media. With the progress of side chain cleavage under fixed external conditions, the polymer conjugates express a thermoresponsive property, followed by shifting a phase boundary due to the change in polymer composition. When the phase transition boundary eventually reached the examined temperature, phase transition occurs under fixed external conditions. Such new insight obtained in this study opens up the new concept of time-programed stimuli-responsive polymer possessing a cleavage-induced phase transition.

Hydrophilic Hyperbranched Polymer-Coated siRNA/Polyamidoamine Dendron-Bearing Lipid Complexes Preparation for High Colloidal Stability and Efficient RNAi.

RNA interference (RNAi) using siRNA has gained much attention for use in therapies for cancer and genetic disorders. To establish RNAi-based therapeutics, the development of efficient siRNA nanocarriers is desired. Earlier, we developed polyamidoamine dendron-bearing lipids able to form complexes with nucleic acids as gene vectors. Especially, dendron lipids with unsaturated alkyl chains (DL-G1-U2) induced efficient endosomal escape by membrane fusion, leading to efficient transfection in vitro. For this study, dendron lipids having oleyl/linoleyl groups (DL-G1-U3) were designed to increase membrane fusogenic activity further. Indeed, DL-G1-U3/siRNA complexes achieved higher membrane fusogenic activity and knockdown of the target gene more efficiently than conventional DL-G1-U2/siRNA complexes did. A hydrophilic polymer, hyperbranched polyglycidol lauryl ester (HPG-Lau), was modified further on the surface of DL-G1-U3/siRNA complexes to provide colloidal stability. Surface modification of HPG-Lau increased the colloidal stability in a physiological condition more than complexes without HPG-Lau. Importantly, HPG-Lau-coated DL/siRNA complexes showed identical RNAi effects to those of parental DL/siRNA complexes, whereas the RNAi activity of poly(ethylene glycol)-bearing lipid (PEG-PE)-modified DL/siRNA complexes was hindered completely. Introduction of unsaturated bonds into dendron lipids and selection of suitable hydrophilic polymers for nanocarrier modification are important for obtaining efficient siRNA vectors toward in vivo siRNA delivery.

Multifunctional Traceable Liposomes with Temperature-Triggered Drug Release and Neovasculature-Targeting Properties for Improved Cancer Chemotherapy.

Poor distribution of nanocarriers at the tumor site and insufficient drug penetration into the tissue are major challenges in the development of effective and safe cancer therapy. Here, we aim to enhance the therapeutic effect of liposomes by accumulating doxorubicin-loaded liposomes at high concentrations in and around the tumor, followed by heat-triggered drug release to facilitate low-molecular-weight drug penetration throughout the tumor. A cyclic RGD peptide (cRGD) was incorporated into liposomes decorated with a thermosensitive polymer that allowed precise tuning of drug release temperature (i.e., Polymer-lip) to develop a targeted thermosensitive liposome (cRGD-Polymer-lip). Compared with conventional thermosensitive liposomes, cRGD-Polymer-lip enhanced the binding of liposomes to endothelial cells, leading to their accumulation at the tumor site upon intravenous administration in tumor-bearing mice. Drug release triggered by local heating strongly inhibited tumor growth. Notably, tumor remission was achieved via multiple administrations of cRGD-Polymer-lip and heat treatments. Thus, combining the advantages of tumor neovascular targeting and heat-triggered drug release, these liposomes offer high potential for minimally invasive and effective cancer chemotherapy.

Single Antiplatelet Therapy With Prasugrel vs. Dual Antiplatelet Therapy in Japanese Percutaneous Coronary Intervention Patients With High Bleeding Risk.

BACKGROUND: Outcomes with prasugrel single antiplatelet therapy (SAPT) vs. dual antiplatelet therapy (DAPT) in Japanese percutaneous coronary intervention (PCI) patients with high bleeding risk (HBR) are currently unknown.Methods and Results:Data from 1,173 SAPT and 2,535 DAPT patients from the PENDULUM mono and PENDULUM registry studies (respective median DAPT durations: 108 vs. 312 days) were compared. The adjusted cumulative incidence of Bleeding Academic Research Consortium (BARC) 2, 3, or 5 bleeding from 1 to 12 months after PCI (primary endpoint) was 2.8% (95% confidence interval [CI], 1.9-4.2) and 4.1% (95% CI, 3.3-5.1), respectively (hazard ratio [HR], 0.69; 95% CI, 0.45-1.06; P=0.090). The adjusted cumulative incidences of BARC 2, 3, or 5 bleeding from 0 to 12 months after PCI (secondary endpoint) were 3.8% (95% CI, 2.7-5.3) and 5.6% (95% CI, 4.7-6.7), respectively (HR, 0.68; 95% CI, 0.47-0.98; P=0.039). There was no significant difference in major adverse cardiac and cerebrovascular events (MACCE) from 1 to 12 months after PCI (HR, 0.93; 95% CI, 0.63-1.37; P=0.696) and at 12 months after PCI (HR, 0.85; 95% CI, 0.61-1.19; P=0.348) between the groups. CONCLUSIONS: Prasugrel SAPT may reduce BARC 2, 3, or 5 bleeding, without increasing MACCE, in Japanese patients with HBR.

Visualization of the human enteric nervous system by probe confocal laser endomicroscopy: a first real-time observation of Hirschsprung's disease and allied disorders.

BACKGROUND: Our group previously proved that the human enteric nervous system can be visualized with confocal laser endomicroscopy after topical application of cresyl violet using surgically resected intestine specimens. The present report documents the first in vivo visualization of the human enteric nervous system with confocal laser endomicroscopy using local cresyl violet staining. The aim of this study was to evaluate the technical feasibility and clinical efficiency of confocal laser endomicroscopy in patients with Hirschsprung's disease and allied disorders in vivo. METHODS: Confocal laser endomicroscopy was performed in vivo in two patients to confirm the presence of the enteric nervous system during surgery in patients with Hirschsprung's disease and allied disorders. Cresyl violet was gently injected from the serosal side into the muscular layer of the intestine, and scanning was performed within 30 min. Then, the scanned intestines were resected, and the visualized area of the specimens was pathologically evaluated. RESULTS: The ganglion cell nuclei and the enteric nervous system network were clearly visualized intraoperatively in both cases. The morphological findings were similar to the pathological findings of the enteric nervous system in both cases although the period of visibility was brief. CONCLUSION: This study demonstrated the first, real-time observation of the enteric nervous system in humans using confocal laser endomicroscopy and suggest the potential to identify the enteric nervous system intra-operatively during surgery for Hirschsprung's disease and allied disorders.

Assessment of eldecalcitol and alendronate effect on postural balance control in aged women with osteoporosis.

INTRODUCTION: Older people aged over 75 are more prone to falls because physical functions become deteriorated along with aging, and also fracture risk is strongly correlated with age. We evaluated the effects of anti-osteoporosis agents, eldecalcitol (ELD) and alendronate (ALN) on physical functions by assessing dynamic and static postural balance in aged patients with osteoporosis. MATERIALS AND METHODS: A randomized, open-label, controlled clinical trial has been conducted with 124 female patients aged 65 or over with osteoporosis. Patients were randomly assigned to receive either 0.75 µg of ELD once-a-day or 35 mg of ALN once-a-week for 24 weeks. The primary endpoint was the change in a postural balance index, adjusted composite equilibrium score (CES) of sensory organization test (SOT). The SOT equilibrium scores, leg muscle strength, and other physical functions were also evaluated. RESULTS: The Adjusted CES increased from baseline by 6.10% in the ELD group and 6.28% in the ALN group. There was no statistically significant difference between the two groups. The static postural balance at fixed platform were maintained in the ELD group, but declined in the ALN group. The dynamic postural balance at swaying platform and knee extension power increased from baseline in both groups. CONCLUSIONS: These results suggest that ELD and ALN treatments may each be beneficial to improve postural balance control in older patients with osteoporosis via different mechanisms of action.

Monotherapy With Prasugrel After Dual-Antiplatelet Therapy for Japanese Percutaneous Coronary Intervention Patients With High Bleeding Risk　- A Prospective Cohort Study (PENDULUM mono Study).

BACKGROUND: The risks of bleeding and cardiovascular events in high bleeding risk (HBR) Japanese patients undergoing percutaneous coronary intervention (PCI) while receiving single-antiplatelet therapy (SAPT) remains unknown. We aimed to evaluate the frequency of bleeding and cardiovascular events associated with prasugrel monotherapy after short-term dual-antiplatelet therapy (DAPT) in Japanese HBR patients after PCI.Methods and Results:The PENDULUM mono study was a multicenter, non-interventional, prospective registry (n=1,173). The primary endpoint was the cumulative incidence of clinically relevant bleeding (CRB; Bleeding Academic Research Consortium types 2, 3, and 5) from 1 to 12 months after PCI. Secondary endpoints included major adverse cardiac and cerebrovascular events (MACCE). The proportion of patients who received prasugrel monotherapy at 12 months after PCI was 79.7%, and no cases of stent thrombosis were observed among these patients. The cumulative incidence of CRB was 3.2% from 1 to 12 months after PCI; that of MACCE was 3.8%. Severe anemia, chronic kidney disease, oral anticoagulant use at discharge, and heart failure were significantly associated with CRB. CONCLUSIONS: Among HBR patients undergoing PCI who were not suitable for concomitant aspirin and were scheduled for prasugrel monotherapy, most patients were on prasugrel monotherapy after DAPT. Cumulative incidences of CRB and MACCE after periprocedural period were 3.2% and 3.8%, respectively, and no cases of stent thrombosis were reported. SAPT might be a suitable alternative to DAPT.

Prasugrel effectively reduces the platelet reactivity units in patients with genetically metabolic dysfunction of cytochrome P450 2C19 who are treated with long-term dual antiplatelet therapy after undergoing drug-eluting stent implantation.

Dual antiplatelet therapy (DAPT) with aspirin and P2Y12 inhibitor is administered following percutaneous coronary intervention (PCI) with coronary stent implantation. Several studies have reported the effects of switching between P2Y12 inhibitors on platelet reactivity (P2Y12 reaction units: PRU), from acute to late phase after PCI. However, the effect of switching at very late phase is unknown. This study examined the effect on PRU in Japanese coronary heart disease patients with long-term DAPT (aspirin + clopidogrel) when switching from clopidogrel to prasugrel. Ninety-six patients were enrolled in this study. The median DAPT duration at enrollment was 1824.0 days. Twenty-three patients with PRU ≥ 208 at enrollment were randomly assigned into either continuing to receive clopidogrel (Continued Group; n = 11) or switching to prasugrel (Switched Group; n = 12). The primary endpoint was the rate of patients who achieved PRU < 208 at the end of 12 weeks of treatment, which was significantly higher in Switched Group relative to Continued Group (90.0% vs. 36.4%; P = 0.024). The secondary endpoint was the PRU at week 12 in groups subdivided according to cytochrome P450 (CYP) 2C19 genotypes. At week 12, extensive metabolizers (EM Group) had 202.3 ± 60.0 and 174.5 ± 22.3 in Continued Group and Switched Group (P = 0.591), respectively; intermediate and poor metabolizers (non-EM Group) had 229.4 ± 36.9 and 148.4 ± 48.4 in Continued Group and Switched Group (P = 0.002), respectively. The PRU for non-EM Group was significantly reduced in Switched Group. Thus, for patients with long-term DAPT (aspirin + clopidogrel) after PCI with coronary stent implantation, switching from clopidogrel to prasugrel resulted in a stable reduction in PRU, regardless of CYP2C19 polymorphism.

The outcomes of conservative management and the natural history of asymptomatic hydroceles in children.

PURPOSE: To elucidate the natural history of asymptomatic hydroceles (AHs) in children with conservative management and to discuss management strategies for AHs in children. METHODS: We retrospectively reviewed 113 children with AHs who were followed without immediate surgery. Patients were divided into four groups according to age at presentation; group 1: ≤ 1 month, group 2: 1-12 months, group 3: 12-24 months, and group 4: > 24 months. Ages at spontaneous resolution or surgery were reviewed. To assess the effect of AH on the testis, testicular size before and after conservative management was compared in 11 cases. RESULTS: In groups 1, 2, 3, and 4, spontaneous resolution occurred in 94.3%, 75.0%, 65.0%, and 33.3%, and the average time to resolution from presentation was 5, 5, 17, and 9 months, respectively. 41 patients underwent surgery at a mean age of 4.2 years. The testicular size did not differ significantly between before and after conservative management (14.4 vs. 14.5 mm, p = 0.483). CONCLUSION: About one-third of children over 2 years of age achieve spontaneous resolution. Hydroceles with conservative management may not affect the testicular size. Thus, initial conservative management before surgery is recommend for AHs in children, even over 2 years of age.

Highly Ordered Polypeptide with UCST Phase Separation Behavior.

Manipulating phase separation structures of thermoresponsive polymers will enhance the usefulness of structure-controllable materials in fields such as drug delivery and tissue engineering. However, behaviors of upper critical solution temperature (UCST) have been less investigated so far, despite the importance of UCST. Here, we examined two citrulline-based polypeptides, poly(d-ornithine- co-d-citrulline) (PdOC) and poly(dl-ornithine- co-dl-citrulline) (PdlOC), to investigate how stereoregularity of the polypeptides influences UCST behavior, in addition to poly(l-ornithine- co-l-citrulline) (PlOC) previously studied. Homochiral PlOC and PdOC showed phase separation temperatures ( Tps) higher than that of racemic PdlOC. Moreover, PdlOC underwent liquid to coacervate phase separation at Tp, whereas PlOC and PdOC underwent liquid to solid-like aggregation transitions. From a structural point of view, circular dichroism and small-angle X-ray scattering measurements revealed that homochiral PlOC and PdOC polypeptides formed α-helical structures and assembled into a regular hexagonal lattice upon phase separation. Interactions between the pendent ureido groups of homochiral POCs appear to play pivotal roles in helical folding and assembly into the hexagonal structure. In addition, Tp change in response to biodegradation was confirmed for both PlOC and PdlOC. The biodegradability was considerably influenced by phase-separated structures. These findings of UCST-type POCs in this study would provide important insights into structure-controllable and thermoresponsive biomaterials.

Chondroitin Sulfate-Based pH-Sensitive Polymer-Modified Liposomes for Intracellular Antigen Delivery and Induction of Cancer Immunity.

Induction of cancer-specific cytotoxic T lymphocytes is crucially important to complement therapeutic effects of immune checkpoint inhibitors and to achieve efficient cancer immunotherapy. To induce cancer-specific cytotoxic T lymphocytes, cancer antigen carriers must have multiple functions to deliver cancer antigens to antigen presenting cells, release antigens into cytosol, and promote the maturation of these cells. We earlier achieved cytosolic delivery of antigens and induction of antigen-specific cytotoxic T lymphocytes using carboxylated polyglycidol or polysaccharide derivative-modified liposomes that can induce membrane fusion with endosomes in response to weakly acidic pH. Furthermore, pH-sensitivity and adjuvant properties of these polymers were enhanced strongly by introduction of hydrophobic carboxylated units to dextran. Against our expectations, these polymer-modified liposomes only slightly induce cancer immunity, probably because of the high hydrophobicity of spacer units. This study used a polysaccharide with charged groups (chondroitin sulfate) instead of dextran as a backbone to reduce hydrophobicity. Chondroitin sulfate derivative-modified liposomes showed almost equal pH-sensitivity to that of dextran derivative-modified liposomes and achieved selective delivery to dendritic cells, whereas dextran derivative-modified liposomes were highly taken up by both dendritic cells and fibroblasts. Chondroitin sulfate derivative-modified liposomes delivered model antigenic proteins into cytosol of dendritic cells and promoted cytokine production from the cells, leading to tumor regression on tumor-bearing mice after subcutaneous administration. Results demonstrate that charged groups having polysaccharide as a backbone can be used in an effective strategy to balance strong hydrophobicity of spacer units with their utilization for immunity-inducing systems.