Detection of SARS-CoV-2 Genome for over 100 Days after COVID-19 Onset.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is spreading globally. Generally, the viral genome becomes undetectable within a couple of weeks after infection. Herein, we report a case of long-term detection of the SARS-CoV-2 genome in the same individual for 106 days. Whole genome sequencing was performed on specimens taken at the onset of the disease and 2 months after onset, and the B.1.1.7 lineage was detected in both samples. A comparison of the full-length sequences revealed a single-base difference and no amino acid mutations. This is the first case in Japan where the virus was detected over a long period, and the full-length sequences were compared.

Development of Parallel Reaction Monitoring Mass Spectrometry Assay for the Detection of Human Norovirus Major Capsid Protein.

Human Norwalk viruses (HuNoVs), the most common etiological agents of acute gastroenteritis, are genetically diverse RNA viruses that frequently cause mass food poisoning internationally. Although nucleic acid detection methods, such as reverse transcription-quantitative polymerase chain reaction (RT-qPCR), are the gold standard for the diagnosis of norovirus infection, alternative methods are needed for the specific and sensitive viral protein detection for rapid diagnosis and surveillance. In this study, we developed a robust and high-throughput targeted proteomic assay workflow to directly detect the VP1 major capsid protein of HuNoVs. A parallel reaction monitoring (PRM) assay using a high-resolution mass spectrometer was used to detect representative peptides derived from VP1 in six different HuNoV genotypes. An optimized protocol using synthesized heavy isotope-labeled peptides as internal standards was also used to simultaneously genotype and quantify the VP1 protein in human stool specimens. This method is expected to become a new tool for studying the molecular epidemiology of HuNoV and to shed new light on targeted proteomics in clinical practice.

A discernable increase in the severe acute respiratory syndrome coronavirus 2 R.1 lineage carrying an E484K spike protein mutation in Japan.

Three COVID-19 waves in Japan have been characterized by the presence of distinct PANGO lineages (B.1.1. 162, B.1.1.284, and B.1.1.214). Recently, in addition to the B.1.1.7 lineage, which shows 25% abundance, an R.1 lineage carrying the E484K mutation in the spike protein was found to show up to 40% predominance. E484K could be a pivotal amino acid substitution with the potential to mediate immune escape; thus, more attention should be paid to such potential variants of concern to avoid the emergence of mutants of concern. Such comprehensive real-time genome surveillance has become essential for the containment of COVID-19 clusters.

A Longitudinal Study on Enteric Virus Contamination in Bivalves along the Coast of Ibaraki Prefecture, Japan.

ABSTRACT: During the 2014 to 2018 seasons, we conducted a longitudinal study involving enteric virus surveillance in bivalves, including natural oysters and clams harvested in Ibaraki Prefecture, Japan. Some norovirus (NoV) contaminations were detected in natural oysters, whereas no enteric virus was found in clams. NoVs detected in oysters were of the genotypes GII.4 and GII.6, both of which are closely related genetically to the NoV strains prevalent in humans. We found low level of enteric virus contamination in bivalves collected along the coast of Ibaraki Prefecture. The possibility of food poisoning caused by these viruses appears low, and few cases of infectious disease have been observed in the surrounding area. The harvest timing was more related to contamination quantity than the harvest area in many enteric viruses. Our results highlight that contamination of bivalves by enteric viruses may depend upon the prevalence of human diarrhea and illness.

Development of a predictive model for integrated medical and long-term care resource consumption based on health behaviour: application of healthcare big data of patients with circulatory diseases.

BACKGROUND: Medical costs and the burden associated with cardiovascular disease are on the rise. Therefore, to improve the overall economy and quality assessment of the healthcare system, we developed a predictive model of integrated healthcare resource consumption (Adherence Score for Healthcare Resource Outcome, ASHRO) that incorporates patient health behaviours, and examined its association with clinical outcomes. METHODS: This study used information from a large-scale database on health insurance claims, long-term care insurance, and health check-ups. Participants comprised patients who received inpatient medical care for diseases of the circulatory system (ICD-10 codes I00-I99). The predictive model used broadly defined composite adherence as the explanatory variable and medical and long-term care costs as the objective variable. Predictive models used random forest learning (AI: artificial intelligence) to adjust for predictors, and multiple regression analysis to construct ASHRO scores. The ability of discrimination and calibration of the prediction model were evaluated using the area under the curve and the Hosmer-Lemeshow test. We compared the overall mortality of the two ASHRO 50% cut-off groups adjusted for clinical risk factors by propensity score matching over a 48-month follow-up period. RESULTS: Overall, 48,456 patients were discharged from the hospital with cardiovascular disease (mean age, 68.3 ± 9.9 years; male, 61.9%). The broad adherence score classification, adjusted as an index of the predictive model by machine learning, was an index of eight: secondary prevention, rehabilitation intensity, guidance, proportion of days covered, overlapping outpatient visits/clinical laboratory and physiological tests, medical attendance, and generic drug rate. Multiple regression analysis showed an overall coefficient of determination of 0.313 (p < 0.001). Logistic regression analysis with cut-off values of 50% and 25%/75% for medical and long-term care costs showed that the overall coefficient of determination was statistically significant (p < 0.001). The score of ASHRO was associated with the incidence of all deaths between the two 50% cut-off groups (2% vs. 7%; p < 0.001). CONCLUSIONS: ASHRO accurately predicted future integrated healthcare resource consumption and was associated with clinical outcomes. It can be a valuable tool for evaluating the economic usefulness of individual adherence behaviours and optimising clinical outcomes.

Synthetic poly(2-acrylamido-2-methylpropanesulfonic acid) gel induces chondrogenic differentiation of ATDC5 cells via a novel protein reservoir function.

We previously demonstrated that a synthetic negatively charged poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) gel induced chondrogenic differentiation of ATDC5 cells. In this study, we clarified the underlying molecular mechanism, in particular, focusing on the events that occurred at the interface between the gel and the cells. Gene expression profiling revealed that the expression of extracellular components was enhanced in the ATDC5 cells that were cultured on the PAMPS gel, suggesting that extracellular proteins secreted from the ATDC5 cells might be adsorbed in the PAMPS gel, thereby contributing to the induction of chondrogenic differentiation. Therefore, we created "Treated-PAMPS gel," which adsorbed various proteins secreted from the cultured ATDC5 cells during 7 days. Proteomic analysis identified 27 proteins, including extracellular matrix proteins such as Types I, III, and V collagens and thrombospondin (THBS) in the Treated-PAMPS gel. The Treated-PAMPS gel preferentially induced expression of chondrogenic markers, namely, aggrecan and Type II collagen, in the ATDC5 cells compared with the untreated PAMPS gel. Addition of recombinant THBS1 to the ATDC5 cells significantly enhanced the PAMPS-induced chondrogenic differentiation, whereas knockdown of THBS1 completely abolished this response. In conclusion, we demonstrated that the PAMPS gel has the potential to induce chondrogenic differentiation through novel reservoir functions, and the adsorbed THBS plays a significant role in the induction.

A Genome Epidemiological Study of SARS-CoV-2 Introduction into Japan.

After the first case of coronavirus disease 2019 (COVID-19) in Japan on 15 January 2020, multiple nationwide COVID-19 clusters were identified by the end of February. The Japanese government focused on mitigating the emerging COVID-19 clusters by conducting active nationwide epidemiological surveillance. However, an increasing number of cases continued to appear until early April 2020, many with unclear infection routes and no recent history of travel outside Japan. We aimed to evaluate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome sequences from the COVID-19 cases that appeared until early April 2020 and to characterize their genealogical networks in order to demonstrate possible routes of spread in Japan. Nasopharyngeal specimens were collected from patients, and reverse transcription-quantitative PCR tests for SARS-CoV-2 were performed. Positive RNA samples were subjected to whole-genome sequencing, and a haplotype network analysis was performed. Some of the primary clusters identified during January and February 2020 in Japan descended directly from the Wuhan-Hu-1-related isolates from China and other distinct clusters. Clusters were almost contained until mid-March; the haplotype network analysis demonstrated that the COVID-19 cases from late March through early April may have created an additional large cluster related to the outbreak in Europe, leading to additional spread within Japan. In conclusion, genome surveillance has suggested that there were at least two distinct SARS-CoV-2 introductions into Japan from China and other countries.IMPORTANCE This study aimed to evaluate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome sequences from COVID-19 cases and to characterize their genealogical networks to demonstrate possible routes of spread in Japan. We found that there were at least two distinct SARS-CoV-2 introductions into Japan, initially from China and subsequently from other countries, including Europe. Our findings can help understand how SARS-CoV-2 entered Japan and contribute to increased knowledge of SARS-CoV-2 in Asia and its association with implemented stay-at-home/shelter-in-place/self-restraint/lockdown measures. This study suggested that it is necessary to formulate a more efficient containment strategy using real-time genome surveillance to support epidemiological field investigations in order to highlight potential infection linkages and mitigate the next wave of COVID-19 in Japan.

Development of Monoclonal Antibodies and Antigen-Capture ELISA for Human Parechovirus Type 3.

Human parechovirus type 3 (HPeV3) is an etiologic agent of respiratory diseases, meningitis, and sepsis-like illness in both infants and adults. Monoclonal antibodies (mAbs) can be a promising diagnostic tool for antigenic diseases such as virus infection, as they offer a high specificity toward a specific viral antigen. However, to date, there is no specific mAb available for the diagnosis of HPeV3 infection. In this study, we developed and characterized mAbs specific for HPeV3 capsid protein VP0. We used cell-free, wheat germ-synthesized viral VP0 protein for immunizing BALB/c mice to generate hybridomas. From the resultant hybridoma clones, we selected nine clones producing mAbs reactive to the HPeV3-VP0 antigen, based on enzyme-linked immunosorbent assay (ELISA). Epitope mapping showed that these mAbs recognized three distinct domains in HPeV3 VP0. Six mAbs recognized HPeV3 specifically and the other three mAbs showed cross-reactivity with other HPeVs. Using the HPeV3-specific mAbs, we then developed an ELISA for viral antigen detection that could be reliably used for laboratory diagnosis of HPeV3. This ELISA system exhibited no cross-reactivity with other related viruses. Our newly developed mAbs would, thus, provide a useful set of tools for future research and ensure HPeV3-specific diagnosis.

Examining the association between the "My Pharmacist" model and the service quality of community pharmacies.

BACKGROUND: In Japan, patients can freely choose medical facilities. Many visit different medical facilities for different diseases, and for convenience, often utilize the pharmacies neighboring these facilities. Accordingly, a "My Pharmacy" model was recommended, in which patients select a single pharmacy using their own judgement to receive proper medication services. A "My Pharmacist" model, in which the pharmacist is constantly involved in the treatment of a patient, was also proposed. However, patients' evaluations of pharmacist/pharmacy services under these models have not been investigated. OBJECTIVE: To examine how a patient's constant involvement with the same pharmacist and pharmacy is associated with their evaluation of the quality of pharmacy services. METHODS: A cross-sectional survey using a self-administered questionnaire was conducted among patients who used pharmacies periodically. Patients evaluated the pharmacist/pharmacy services and were classified into 4 groups ("My Pharmacy/My Pharmacist," "My Pharmacy/Multiple Pharmacists," "Multiple Pharmacies/My Pharmacist," and "Multiple Pharmacies/Multiple Pharmacists") according to the form of their usage of pharmacies and pharmacists. An intergroup comparison was then performed and correlations within each group analyzed. RESULTS: Data from 3,492 individuals using 147 pharmacies were analyzed. "My Pharmacy" users had significantly higher scores than did "Multiple Pharmacies" users on patient experience of proper medication services (e.g., identifying duplicate medication) (p < 0.001). "My Pharmacy/My Pharmacist" users scored higher than the other three groups on four evaluation factors, including "pharmacy/pharmacist's interpersonal services" ("sharing and utilizing patient information," "enhanced health support function," and "consideration towards patients"), "patient satisfaction with the pharmacy," "placing more emphasis on quality of interaction with pharmacist than on waiting time," and "attitude when visiting healthcare facilities" (all p < 0.001). CONCLUSION: The findings indicate that highly tailored, in-person services provided by "My Pharmacists" are associated with not only with the degree of patients' overall satisfaction, but also their evaluation of "the quality of pharmacist services."

Cultural influence on mindful eating: traditions and values as experienced by Mexican-American and non-Hispanic white parents of elementary-school children.

OBJECTIVE: To examine perceptions of mindful eating and mindful food parenting among parents of elementary school children. METHODS: Four focus groups were conducted with 19 Mexican-American parents and 13 non-Hispanic white parents of children from a northern California elementary school. RESULTS: Themes emerging from this research included food traditions during mealtime, perceptions of mindful eating, mindful food parenting and portion control, mindful food parenting practices through gardening, and mindful food parenting with traditional foods. Mexican-American participants identified cooking traditional foods as an important part of their mindful eating and food parenting practices. Mexican-American participants also highlighted the importance of using their senses to appreciate food. Both Mexican-American and non-Hispanic white participants emphasized the importance of involving children in gardening and meal preparation. Mexican-American parents had different perceptions of food portion control than the non-Hispanic white participants. CONCLUSIONS: The current study indicates the importance of mindfulness in broad food-related practices such as gardening, cooking and preserving food traditions in mindful eating practices. More research is needed to further understand how culture shapes and impacts these food practices among different cultural groups.

[What Is Involved in the Training Program for a Japanese Academic Detailer?]

'Academic Detailing' is an approach to providing doctors with information about medicines based on the latest non-commercial evidence-based data for proper prescription. Overseas, pharmacists have been active as academic detailers. Academic Detailing in Japan, as a new approach to disseminating comparative drug information based on basic pharmaceutical sciences and clinical evidence, will influence clinical decision making by doctors, and contribute to better patient-centered medical care. Pharmacists have been participating in ensuring the proper use of drugs by their patients by entering their homes or wards. However, in the future, it is necessary to take steps to improving pharmaceutical decision making by doctors. Therefore, we are considering the following educational points in the Japanese version of training an academic detailer. "A: We shall compare medicines based on basic pharmaceutical sciences and the latest non-commercial evidence-based data. B: We shall understand the point of using medicines based on the patient's condition. C: We shall choose cost-effective drugs from the viewpoint of pharmacoeconomics. And D: We shall acquire communication skills for effective academic detailing." In the future, this first class of Academic Detailers who facilitate academic detailing in the health care field will be pioneers. They will also participate in research to track and quantify the effects of academic detailing.

Difference in central nerve system metastasis during gefitinib or erlotinib therapy in patients with EGFR-mutated non-small cell lung cancer: a retrospective study.

BACKGROUND: Central nervous system (CNS) metastasis is a poor prognostic factor in patients with advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation EGFR-mutant NSCLC and is associated with a deteriorated quality of life (QOL). Some clinical studies have suggested a possible difference in the incidence of CNS metastasis between EGFR-mutant NSCLC patients treated with gefitinib and erlotinib, both of which are classified as first-generation EGFR tyrosine kinase inhibitors (TKIs). However, the difference in the incidence of CNS metastasis between patients receiving these two drugs has not yet been sufficiently well investigated. We analyzed the frequency of occurrence/progression of CNS metastasis in EGFR-mutant NSCLC patients treated with erlotinib and gefitinib as the first-line treatment. METHODS: We analyzed the incidence of CNS metastasis, frequency of progression of CNS metastasis and the treatment outcomes in EGFR-mutant patients who received gefitinib or erlotinib as the first-line EGFR-TKI treatment. CNS progressive disease (PD) was defined as progression of CNS metastasis during EGFR-TKI treatment. We also evaluated the progression-free survival (PFS), CNS-PFS, and overall survival (OS) of the patients who received each of the two drugs. RESULTS: A total of 170 patients were enrolled in the study, of which 144 had received gefitinib, and 26 had received erlotinib. The frequency of CNS PD in the erlotinib group tended to be lower than that in the gefitinib group (11.5% vs. 29.9%, P=0.06). In patients with no existing CNS metastasis at the start of the EGFR-TKI treatments, the incidence of CNS PD was significantly lower in the erlotinib group than that in the gefitinib group (4.8% vs. 24.5%, P=0.04). A re-biopsy after failure of EGFR-TKI treatment was performed in 48 patients. The incidence of EGFR T790M tended to be higher among patients with CNS PD than in those without CNS PD, although the difference was not statistically significant (66.7% vs. 40.4%; P=0.23). CONCLUSIONS: The incidence of progression of CNS metastasis during erlotinib treatment was lower than that during gefitinib treatment. In addition, the difference in the incidence in patients without existing CNS metastasis at the time of start of EGFR-TKI treatment was significantly lower in the patients treated with erlotinib than in those treated with gefitinib.

Variation of human norovirus GII genotypes detected in Ibaraki, Japan, during 2012-2018.

BACKGROUND: Human norovirus (HuNoV) is the major cause of viral acute gastroenteritis for all age groups in various countries. HuNoV GII in particular accounted for the majority of norovirus outbreaks, among which GII.4 caused repeated outbreaks for a long time. Besides GII.4, other norovirus genotypes, GII.2, GII.6, and GII.17, have also been prevalent in various contexts in recent years, but few detailed epidemiological studies of them have been performed and are poorly understood. We thus conducted an epidemiological analysis of HuNoV GII in Ibaraki Prefecture, Japan, by performing surveillance in the six seasons from September 2012 to August 2018. RESULTS: HuNoV GI occurred almost sporadically for all genotypes; however, each genotype of GII exhibited its typical epidemiological characteristics. Although the number of outbreaks of GII.4 decreased season by season, it reemerged in 2017/2018 season. The timing of the epidemic peak in terms of number of cases for GII.17 differed from that for the other genotypes. The patients age with GII.2 and GII.6 were younger and outbreak of GII.17 occurred frequently as food poisoning. Namely, the primarily infected outbreak group differed for each genotype of HuNoV GII. Moreover, the viral load of patients differed according to the genotype. CONCLUSIONS: Various HuNoV genotypes including GII.2, GII.4, GII.6, and GII.17 were shown to be associated with various types of outbreak sites (at childcare and educational facilities, involving cases of food poisoning, and at elderly nursing homes) in this study. These genotypes emerged in recent years, and their prevalence patterns differed from each other. Moreover, differences in outbreak sites and viral load of patients among the genotypes were identified.

Pharmacokinetic study of the oral fluorouracil antitumor agent S-1 in patients with impaired renal function.

Although dose reduction of S-1 is recommended for patients with impaired renal function, dose modification for such patients has not been prospectively evaluated. The aim of the present study was to investigate the pharmacokinetic parameters of 5-fluorouracil, 5-chloro-2,4 dihydroxypyridine and oteracil potassium, and to review the recommended dose modification of S-1 in patients with renal impairment. We classified patients receiving S-1 into 4 groups according to their renal function, as measured using the Japanese estimated glomerular filtration rate (eGFR) equation. The daily S-1 dose was adjusted based on the patient's eGFR and body surface area. Blood samples were collected for pharmacokinetic analysis. A total of 33 patients were enrolled and classified into 4 groups as follows: 10 patients in cohort 1 (eGFR ≥ 80 mL/min/1.73 m2 ), 10 patients in cohort 2 (eGFR = 50-79 mL/min/1.73 m2 ), 10 patients in cohort 3 (eGFR = 30-49 mL/min/1.73 m2 ), and 3 patients in cohort 4 (eGFR < 30 mL/min/1.73 m2 ). Those in cohorts 3 and 4 treated with an adjusted dose of S-1 showed a similar area under the curve for 5-fluorouracil (941.9 ± 275.6 and 1043.5 ± 224.8 ng/mL, respectively) compared with cohort 2 (1034.9 ± 414.3 ng/mL). Notably, while there was a statistically significant difference between cohort 1 (689.6 ± 208.8 ng/mL) and 2 (P = 0.0474) treated with an equal dose of S-1, there was no significant difference observed in the toxicity profiles of the cohorts. In conclusion, dose adjustment of S-1 in patients with impaired renal function using eGFR is appropriate and safe.

High prevalence of hepatitis E virus infection among domestic pigs in Ibaraki Prefecture, Japan.

BACKGROUND: Hepatitis E virus (HEV) is prevalent in pigs and may serve as a reservoir for human infection. However, data on HEV infections in pigs in Ibaraki Prefecture, Japan, are limited. Here, we clarified the process and course of HEV in naturally infected pigs. Serum (n = 160) and liver (n = 110) samples were collected from pigs at the slaughterhouse. Furthermore, serum samples were collected from 45 breeding sows and serum and feces samples were collected from 7 piglets once a week (raised until 166 days of age). HEV antigen and antibodies were evaluated, and the genotype was identified based on molecular phylogenetic tree analysis. RESULTS: The samples collected from the slaughterhouse revealed that few pigs were HEV carriers but most possessed anti-HEV antibodies. Most breeding sows possessed antibodies, and the piglets excreted HEV on the farm at approximately 10 weeks of age. One pig was initially infected, and in a few weeks, the other pigs living in the same sty became infected. CONCLUSIONS: Most pigs in Ibaraki Prefecture were with HEV. On the farm, most piglets were infected with HEV by the time they reached slaughter age. We confirmed that HEV infection is successively transmitted among piglets living in the same sty.

Development and initial validation evidence for a mindful eating questionnaire for children.

Mindful eating interventions have become a focus among health professionals, which warrants a need for a psychometrically solid assessment tool. The current study outlines the development and initial validation of the Mindful Eating Questionnaire (MEQ) adapted for Children (MEQ-C). Participants included 262 third through fifth grade students (53% female, 57% white, non-Hispanic) who participated in a mindful eating intervention Foodie U. Data was also collected from 140 parents. Exploratory factor analysis delineated two factors (Awareness and Mindless Eating). Test-retest analysis with a subsample (n = 93) indicated moderate correlations for both factors. The two subscales have good construct validity and can be utilized in an exploratory sense for mindful eating interventions among children. Specifically, the eight-item mindless eating subscale has good internal consistency reliability and can independently be used as a questionnaire to assess overall mindless eating practices among children. Further research is needed to explore and better understand domains of mindful eating among children besides awareness.

Pregnancy and Breastfeeding during Intrathecal Baclofen Therapy - A Case Study and Review.

We report the case of a young woman who received intrathecal baclofen therapy (ITB) and subsequently became pregnant and had a normal delivery. A 28-year-old woman with flexion myelopathy had anterior decompression with fusion at C4/5 and C5/6 levels. Clinical symptoms improved after surgery. However, when she was 29 years old, her symptoms steadily advanced to Modified Ashworth Scale 3 spasticity level in the lower legs, with pain in both of them and urinary retention tendency. Since a 25 µg intrathecal baclofen injection improved her symptoms, an ITB pump system was implanted. After surgery, lower limb spasticity and urinary retention improved. Two years after ITB pump implantation, the patient married and became pregnant. The patient intended to have normal delivery but the induction of labor was ineffective and childbirth was completed by Cesarean section with lumbar anesthesia. The infant's Apgar score was 8 at 1 min and 9 at 5 min, and birth-weight was 2,704 g. We measured the baclofen concentration in the patient's breast milk using high-performance liquid chromatography/tandem mass spectrometry. The level of baclofen in the breast milk was very low (0.617 ng/ml) and the predicted pharmacological effect on the infant was judged to be negligible. No withdrawal symptoms or muscle tone abnormalities were found after birth. Our findings indicate that ITB therapy could be considered for young women with severe spasticity, even if they plan to have children.

Effects of osteochondral defect size on cartilage regeneration using a double-network hydrogel.

BACKGROUND: There has been increased interest in one-step cell-free procedures to avoid the problems related to cell manipulation and its inherent disadvantages. We have studied the chondrogenic induction ability of a PAMPS/PDMAAm double-network (DN) gel and found it to induce chondrogenesis in animal osteochondral defect models. The purpose of this study was to investigate whether the healing process and the degree of cartilage regeneration induced by the cell-free method using DN gel are influenced by the size of osteochondral defects. METHODS: A total of 63 mature female Japanese white rabbits were used in this study, randomly divided into 3 groups of 21 rabbits each. A 2.5-mm diameter osteochondral defect was created in the femoral trochlea of the patellofemoral joint of bilateral knees in Group I, a 4.3-mm osteochondral defect in Group II, and a 5.8-mm osteochondral defect in Group III. In the right knee of each animal, a DN gel plug was implanted so that a vacant space of 2-mm depth was left above the plug. In the left knee, we did not conduct any treatment to obtain control data. Animals were sacrificed at 2, 4, and 12 weeks after surgery, and gross and histological evaluations were made. RESULTS: The present study demonstrated that all sizes of the DN gel implanted defects as well as the 2.5mm untreated defects showed cartilage regeneration at 4 and 12 weeks. The 4.3-mm and 5.8-mm untreated defects did not show cartilage regeneration during the 12-week period. The quantitative score reported by O'Driscoll et al. was significantly higher in the 4.3-mm and 5.8-mm DN gel-implanted defects than the untreated defects at 4 and 12 weeks (p < 0.05). The 2.5-mm and 4.3-mm DN gel implanted defects maintained relatively high macroscopic and histological scores for the 12-week implantation period, while the histological score of the 5.8-mm DN gel implanted defect had decreased somewhat but statistically significantly at 12 weeks (p = 0.0057). CONCLUSIONS: The DN gel induced cartilage regeneration in defects between 2.5 and 5.8 mm, offering a promising device to establish a cell-free cartilage regeneration therapy and applicable to various sizes of osteochondral defects.

The Effect of Intraoperative Graft Coverage With Preserved Remnant Tissue on the Results of the Pivot-Shift Test After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction: Quantitative Evaluations With an Electromagnetic Sensor System.

BACKGROUND: Remnant tissue preservation may be important in improving graft healing after anterior cruciate ligament (ACL) reconstruction, but it has yet to be established whether remnant tissue preservation improves the control of pivot-shift laxity. HYPOTHESIS: The amount of ACL graft coverage with preserved remnant tissue improves the control of pivot-shift laxity, as qualitatively determined with an electromagnetic device. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The 3-dimensional kinematics were evaluated intraoperatively using an electromagnetic sensor system in 38 patients at the time of anatomic double-bundle ACL reconstruction with remnant tissue preservation and again at a minimum of 12 months postoperatively. The magnitude of the peak coupled anterior tibial translation (pCAT) and the maximal acceleration of posterior translation (APT) during the pivot-shift test were evaluated. The degree of graft coverage by remnant tissue was determined arthroscopically at the end of surgery, which was evaluated quantitatively using a scoring system (0-9 points). The relationship between the values during the pivot-shift test and preoperative and intraoperative factors were assessed. RESULTS: The mean (±SD) side-to-side difference of the pCAT (ΔpCAT) was significantly ( P < .0001) improved from 14.0 ± 5.0 mm to 2.6 ± 1.1 mm. Also, the mean side-to-side difference of the APT (ΔAPT) was significantly ( P < .0001) improved from 525.6 ± 99.7 mm/s2 to 32.9 ± 23.6 mm/s2. The mean initial graft coverage score was 5.3 ± 2.6. The correlation analysis demonstrated that the degree of initial graft coverage was significantly correlated with the ΔpCAT ( r = -0.517, P = .0007) and ΔAPT ( r = -0.532, P = .0005). The status of the reconstructed graft at second-look arthroscopic surgery showed no significant correlations with the degree of initial graft coverage or the results of the pivot-shift test. CONCLUSION: The present study demonstrated that the preservation of ACL remnant tissue in anatomic double-bundle ACL reconstruction appears to improve the control of pivot-shift laxity at a minimum of 12 months postoperatively, as measured by an electromagnetic device. This improvement was significantly affected by the degree of intraoperative graft coverage with preserved remnant tissue.