Viscoelastic and Birefringence Relaxation of Individualized Cellulose Nanofibers in the Dilute and Semidilute Regions.

Viscoelastic relaxation mechanisms of individualized cellulose nanofibers (iCNFs) dispersed in glycerol in the dilute and semidilute regions were investigated by linear viscoelastic and dynamic birefringence measurements. The birefringence relaxation of the iCNFs was described by the orientational and curvature modes of an existing viscoelastic theory for ideal semiflexible polymers (Shankar-Pasquali-Morse theory). However, the Shankar-Pasquali-Morse theory could not fully describe the iCNF viscoelastic relaxation at high frequencies. Considering the results for birefringence relaxation, the experimental tension mode of the iCNFs was evaluated to be higher than the theoretical value. These results show that the viscoelastic relaxations of the iCNFs are different from those of ideal semiflexible polymers, in contrast to cellulose nanocrystals (CNCs). As the iCNF concentration increased, the orientational mode dramatically slowed, which was more drastic than other semiflexible polymers, including CNCs. This anomalous behavior is likely due to the nonideal nature of iCNFs.

[Repair of Vaginal Cuff Dehiscence after Laparoscopic Radical Cystectomy with Gracilis Myocutaneous Flap].

Vaginal cuff dehiscence after total hysterectomy or total cystectomy had been increasing since laparoscopic or robotic surgery became a common surgery among gynecologists and urologists. A 52-yearold woman underwent laparoscopic radical total cystectomy for muscle invasive bladder carcinoma at Rakuwakai Otowa Hospital. She was emergently admitted with a fist-sized lump protruding from her vagina four months after surgery. Physical examination and her past history on admission disclosed vaginal cuff dehiscence after cystectomy. Computed tomographic scan and magnetic resonance imaging showed no bowel evisceration in the lump. We confirmed that the content of lump was peritoneal tissue and removed it by laparoscopic surgery. Simultaneously, we repaired the vaginal cuff dehiscence with a gracilis myocutaneous flap. There was no subsequent recurrence of vaginal dehiscence or bladder carcinoma in one-year follow-up.

Development of a novel approach for restoration of the meniscus using silk-elastin in a rabbit meniscus injury model.

BACKGROUND: Limited healing potential of the meniscus remains a burden for the successful repair of meniscus injuries in the orthopaedic fields. Silk-elastin (SE) is a novel recombinant protein with favorable properties for wound healing. This proof-of-concept study aimed to investigate the therapeutic effect of silk-elastin in a rabbit meniscal defect model. METHODS: A migration assay using rabbit meniscus and synovial cells with various concentrations of SE in a culture medium was conducted to investigate the mechanism of meniscal healing by SE. Additionally, cylindrical defects with a 1.5 mm diameter were created at the anterior horn of the medial meniscus of rabbits. The animals were divided into three groups: 1) the Blank group; defect only, 2) the Col I group; implantation of type I atelocollagen sponge, and 3) the SE group; implantation of SE (150 mg/ml) sponge. Whole medial menisci were harvested at 4, 8, 12, and 24 weeks after surgery. Histological analyses including immunohistochemical staining were performed to assess meniscal healing. RESULTS: In vitro study, Migration assay demonstrated a significantly higher number of migrated cells only in synovial cells. Especially, the SE concentration of 10 µg/mL demonstrated the highest number of migrated cells compared with other concentrations. In vivo study, the SE group exhibited significantly higher Ishida scores than other groups at all time points. Furthermore, the SE group showed higher synovial coverage scores than the Col I group at 4 and 8 weeks. Immunohistochemical staining demonstrated higher type II collagen staining in the SE group compared to other groups at 12 weeks. Implanted SE was efficiently replaced by safranin-O staining positive tissue within 8 weeks. CONCLUSIONS: SE could effectively repair a meniscal defect by inducing coverage of synovial cells. SE has the potential to be a useful material for meniscal repair.

The c.1617del variant of TMEM260 is identified as the most frequent single gene determinant for Japanese patients with a specific type of congenital heart disease.

Although the molecular mechanisms underlying congenital heart disease (CHD) remain poorly understood, recent advances in genetic analysis have facilitated the exploration of causative genes for CHD. We reported that the pathogenic variant c.1617del of TMEM260, which encodes a transmembrane protein, is highly associated with CHD, specifically persistent truncus arteriosus (PTA), the most severe cardiac outflow tract (OFT) defect. Using whole-exome sequencing, the c.1617del variant was identified in two siblings with PTA in a Japanese family and in three of the 26 DNAs obtained from Japanese individuals with PTA. The c.1617del of TMEM260 has been found only in East Asians, especially Japanese and Korean populations, and the frequency of this variant in PTA is estimated to be next to that of the 22q11.2 deletion, the most well-known genetic cause of PTA. Phenotype of patients with c.1617del appears to be predominantly in the heart, although TMEM260 is responsible for structural heart defects and renal anomalies syndrome (SHDRA). The mouse TMEM260 variant (p.W535Cfs*56), synonymous with the human variant (p.W539Cfs*9), exhibited truncation and downregulation by western blotting, and aggregation by immunocytochemistry. In situ hybridization demonstrated that Tmem260 is expressed ubiquitously during embryogenesis, including in the development of cardiac OFT implicated in PTA. This expression may be regulated by a ~ 0.8 kb genomic region in intron 3 of Tmem260 that includes multiple highly conserved binding sites for essential cardiac transcription factors, thus revealing that the c.1617del variant of TMEM260 is the major single-gene variant responsible for PTA in the Japanese population.

Relationships among hip instability, iliofemoral ligament, and pain in patients with developmental dysplasia of the hip.

BACKGROUND: To evaluate the relationships among hip instability, pain, and morphology of the iliofemoral ligament (ILFL) in patients with developmental dysplasia of the hip (DDH) using ultrasonography (US). METHODS: We reviewed 86 patients (109 hips) with DDH (Group D), 40 patients (46 hips) with borderline hip dysplasia (BDDH) (Group B) and 20 patients (23 hips) without hip pain and bony abnormality (control group). Group D was classified into three subgroups-the severe (group SP), moderate (group MP), and none/mild (group NMP) hip pain groups-using the visual analogue scale (VAS). For evaluating hip instability and ILFL morphology, the distance between the anterior edge of the anterior inferior iliac spine (AIIS) and the horizontal line to the femoral head, and ILFL thickness were measured using US. The difference between the distance in the neutral position and Patrick position was calculated and defined as the femoral head translation distance (FTD). RESULTS: FTD and ILFL thickness in group D were significantly larger than those in the control group and group B (P < 0.05). There was a significant positive correlation between FTD and ILFL thickness in three groups (r = 0.57, P < 0.05; r = 0.55, P < 0.05; r = 0.62, P < 0.05, respectively). FTD and ILFL thickness in group SP were significantly larger than those in group NMP (P < 0.05). FTD and ILFL thickness in group D had significantly negative correlations with the lateral center edge (r = -0.54, P < 0.05; r = -0.40, P < 0.05, respectively) and vertical-center-anterior angle (r = -0.51, P < 0.05; r = -0.43, P < 0.05, respectively). CONCLUSIONS: Acetabular bony deficiency, especially in the anterior and lateral region can result in antero-posterior hip instability, leading to thickened ILFL and hip pain, even in patients with BDDH. These findings may facilitate our understanding and treatment of patients with DDH. When hip instability is suspected, hip US examination may help confirm the diagnosis and assist in providing objective clinical diagnostic evidence.

Clinical Characteristics of Coronary-to-Pulmonary Artery Fistula in Patients with Pulmonary Atresia and Ventricular Septal Defect.

The existence of a coronary-to-pulmonary artery fistula (CPF) in pulmonary atresia with ventricular septal defect (PAVSD) potentially affects treatment; however, its clinical features have not been comprehensively described due to the disease's rarity. We reviewed 69 cases from 42 studies to reveal the clinical overview of patients with CPF and PAVSD. Among the included patients, the male-to-female ratio was exactly 1:1, and only two patients (3%) exhibited the 22q11.2 microdeletion syndrome. Regarding anatomical features, CPFs originated from the left coronary artery in 65% of patients, and 62% had other major aortopulmonary collateral arteries. Thirty-nine percent of patients had a definitive CPF diagnosis at 0 years of age, whereas 10% were diagnosed in adulthood. Seventy percent underwent catheter angiography to obtain a definitive CPF diagnosis. Ninety-five percent of patients underwent cardiac surgery, and among them, 43% underwent palliative surgery, whereas 52% underwent one-stage repair. Four patients including three adult patients developed cardiac dysfunction due to myocardial ischemia, and three of them exhibited improved cardiac function after the intervention for CPF. Of all the patients, 88% survived and 12% died. The surgical strategy and prognosis were similar to those in PAVSD patients without CPF. This review provides detailed clinical phenotypes that are potentially useful in enhancing the management of patients with this rare disease.

Investigating the subchondral trabecular bone microstructure in patients with osteonecrosis of the femoral head using multi-detector row computed tomography.

OBJECTIVES: To analyse the microstructural changes of subchondral trabecular bone in patients with osteonecrosis of the femoral head (ONFH) using multi-detector row computed tomography (MDCT). METHODS: We retrospectively investigated 76 hips in 50 patients diagnosed with ONFH between 2017 and 2021. Groups 1, 2, 3, and 4 comprised hips without ONFH, ONFH without femoral head collapse (FHC), ONFH with mild collapse (<2 mm), and ONFH with severe collapse (>2 mm), respectively. All patients underwent MDCT, and the subchondral trabecular bone microstructure was assessed. Regions of interests were set at the lateral boundary of the femoral head necrotic lesion and centre of the acetabular weight-bearing portion. RESULTS: In both the femoral head and the acetabular regions, there were significant differences in Groups 2 and 3 compared to Group 1, with increased volumetric bone mineral density and apparent bone volume fraction, and more plate-like with increased connectivity, indicating that osteosclerotic changes were occurring. CONCLUSIONS: In both the femoral head and the acetabular regions, osteosclerotic changes of subchondral trabecular bone microstructure were present before FHC.

Evaluation of antero-posterior instability of the hip using modified Lequesne's false profile view.

BACKGROUND: Accurate evaluation of hip instability is critical for the diagnosis and successful treatment of developmental dysplasia of the hip (DDH). However, dynamic evaluation of hip instability is not well established. This study aimed to use the lateral view from a radiograph to evaluate dynamic antero-posterior hip instability in patients with DDH. METHODS: Seventy-four patients (92 hips) with DDH (DDH group) and 46 patients (59 hips) without hip pain and DDH (Control group) were examined. A false profile view (FPV) according to Lequesne was taken at standard and 90° flexion with the hip of interest defined as functional FPV; the translation of the center of the femoral head (CFH) obtained from the functional FPV was measured. As a validation test, we measured the anterior translation of the CFH using ultrasonography (US). RESULTS: There was a significant difference between the two groups in the translation of the CFH (p < 0.01). The degree of CFH translation depended on the severity of DDH (lateral center edge angle, r = -0.56, p < 0.01; vertical center anterior margin angle, r = -0.57, p<0.01) and lateralization of the femoral head (head lateralization index, r = 0.54, p < 0.01). There was a significant correlation between functional FPV and US measurements (r = 0.71, p < 0.01). CONCLUSION: The present study confirmed that antero-posterior hip instability in DDH patients can be detected using functional FPV. Our novel measurement, as a new method for assessing hip instability, may be useful for evaluating hip dynamic instability in diagnosing the etiology, and determining and evaluating the treatment for DDH at lower cost and improved accessibility.

Coordination polymer-forming liquid Cu(2-isopropylimidazolate).

The structure of the melt state of one-dimensional (1D) coordination polymer crystal Cu(isopropylimidazolate) (melting temperature T m = 143 °C) was characterized by DSC, variable temperature PXRD, solid-state NMR (SSNMR), viscoelastic measurements, XAS, and DFT-AIMD calculations. These analyses suggested "coordination polymer-forming liquid" formation with preserved coordination bonds above T m. Variable chain configurations and moderate cohesive interaction in adjacent chains are the keys to the rarely observed polymer-forming liquid. The melt structure is reminiscent of the common 1D organic polymer melts such as entanglement or random coil structures.