Association between High HbA1c Levels and Mast Cell Phenotype in the Infrapatellar Fat Pad of Patients with Knee Osteoarthritis.

Diabetes mellitus (DM) has been suggested as a potential risk factor for knee osteoarthritis (KOA), and its underlying mechanisms remain unclear. The infrapatellar fat pad (IPFP) contributes to OA through inflammatory mediator secretion. Mast cells' (MCs) role in diabetic IPFP pathology is unclear. In 156 KOA patients, hemoglobin A1c (HbA1c) was stratified (HbA1c ≥ 6.5, n = 28; HbA1c < 6.5, n = 128). MC markers (TPSB2, CPA3) in IPFP were studied. Propensity-matched cohorts (n = 27 each) addressed demographic differences. MC-rich fraction (MC-RF) and MC-poor fraction (MC-PF) were isolated, comparing MC markers and genes elevated in diabetic skin-derived MC (PAXIP1, ARG1, HAS1, IL3RA). TPSB2 and CPA3 expression were significantly higher in HbA1c ≥ 6.5 vs. <6.5, both before and after matching. MC-RF showed higher TPSB2 and CPA3 expression than MC-PF in both groups. In the HbA1c ≥ 6.5 group, PAXIP1 and ARG1 expression were significantly higher in the MC-RF than MC-PF. However, no statistical difference in the evaluated genes was detected between the High and Normal groups in the MC-RF. Elevated TPSB2 and CPA3 levels in the IPFP of high HbA1c patients likely reflect higher numbers of MCs in the IPFP, though no difference was found in MC-specific markers on a cell-to-cell basis, as shown in the MC-RF comparison. These findings deepen our understanding of the intricate interplay between diabetes and KOA, guiding targeted therapeutic interventions.

Increase in TPSB2 and TPSD1 Expression in Synovium of Hip Osteoarthritis Patients Who Are Overweight.

While research suggests that increasing body mass index (BMI) is a risk factor for hip osteoarthritis (HOA), the mechanisms of this effect are not fully understood. Tryptases are among the main proteases found in mast cells (MCs) and contribute to OA pathology. TPSB2, which encodes ß-tryptase, is increased in the synovium of overweight and obese knee OA patients. However, it remains unclear whether tryptase in the synovium of HOA is increased with increasing BMI. Here, we investigated tryptase genes (TPSB2 and TPSD1) in the synovium of overweight HOA patients. Forty-six patients radiographically diagnosed with HOA were allocated to two groups based on BMI, namely normal (<25 kg/m2) and overweight (25-29.99 kg/m2). TPSB2 and TPSD1 expression in the synovium of the two groups was compared using real-time polymerase chain reaction. To compare TPSB2 and TPSD1 expression in MCs between the groups, we isolated the MC-rich fraction (MC-RF) and MC-poor fraction (MC-PF), extracted using magnetic isolation. TPSB2 and TPSD1 expression was increased in the overweight group compared with the normal group. Expression of both genes in the MC-RF was significantly higher than that in MC-PF in both groups. However, TPSB2 and TPSD1 expression levels in the MC-RF did not differ between the groups. Tryptase genes were highly expressed in the synovium of overweight HOA patients. Further investigation to reveal the role of tryptase in the relationship between increasing BMI and HOA pathology is required.

Increased NMUR1 Expression in Mast Cells in the Synovial Membrane of Obese Osteoarthritis Patients.

Obesity is a risk factor for knee osteoarthritis (KOA). Neuromedin U (NMU) and NMU receptors (NMUR1 and NMUR2) are associated with obesity-related disorders and found in mast cells (MCs), which are elevated in osteoarthritis. However, NMU/NMUR expression was not examined in the synovial membrane (SM) or synovial MCs of obese osteoarthritis patients. We compared expression of NMU, NMUR1, NMUR2, and the mast cell (MC) marker, CPA3, in the SM of KOA patients categorized as normal weight (NW; BMI < 25 kg/m2, n = 79), overweight (OW; BMI ≥ 25 and <30 kg/m2, n = 87), and obese (OB; ≥30 kg/m2, n = 40). To study NMU/NMUR expression in MCs, we compared the MC-rich fraction (MC-RF), CD88(+) MC-RF, and CD88(−) MC-RF, extracted using magnetic isolation, with the MC-poor fraction (MC-PF). While NMU and NMUR2 expression were comparable, NMUR1 was significantly elevated in OW and OB compared to NW. Moreover, CPA3 levels were significantly greater in OB than NW. NMUR1 and CPA3 expression were significantly higher in both the CD88(+) and CD88(−) MC-RF than MC-PF. Therefore, NMUR1 expression was elevated in the SM of OB KOA patients, and its expression was found in MCs. Further investigation to analyze the NMU/NMUR1 pathway in MC may provide a link between obesity and KOA pathology.

Long-term antibacterial activity of vancomycin from calcium phosphate cement in vivo.

BACKGROUND: Periprosthetic joint infection is a major complication of total joint arthroplasty, with treatment requiring a two-stage exchange procedure and 6 weeks of systemic antibiotics. However, depending on the infection site, intravenous delivery of antibiotics like vancomycin (VCM) can have poor tissue transferability, thus reducing their therapeutic effect. OBJECTIVE: This study demonstrates the 24-week in vivo release profile and antibacterial activity of VCM from calcium phosphate cement impregnated with VCM (CPC/VCM) and compares them with those from polymethylmethacrylate impregnated with VCM (PMMA/VCM). METHODS: Rats were implanted with the test specimens between the fascia and quadriceps. After implantation for 24 weeks, the test specimens were removed and residual VCM was extracted to calculate the concentration of VCM released into rat tissues. We also examined the antibacterial activity of releasable VCM from the removed test specimens by placing them directly onto the surface of agar. RESULTS: CPC/VCM released greater concentrations of VCM for a longer period of time within the 24 weeks than PMMA/VCM. Moreover, CPC/VCM released 1.4 to 26.1-fold more VCM than PMMA/VCM. Using Staphylococcus aureus, antibacterial activity was logarithmically correlated with VCM concentration across the entire concentration range tested (12.5-800 µg/mL). While the area within which inhibition was observed-the inhibition zone-for both CPC/VCM and PMMA/VCM formed and gradually shrank with time after implantation, that for CPC/VCM was significantly larger than that for PMMA/VCM in each week after implantation. CONCLUSION: CPC/VCM releases greater amounts of VCM with antibacterial activity for longer periods of time than PMMA/VCM, suggesting that CPC is effective for facilitating the release of antibiotics for local action in patients with established postoperative infection.

Increase in CD5L expression in the synovial membrane of knee osteoarthritis patients with obesity.

INTRODUCTION: Obesity appears to be a powerful risk factor for the development of knee osteoarthritis (KOA), but the mechanisms of this are not fully understood. CD5L is expressed in tissue macrophages and is increased in obese mice. We hypothesized that CD5L expression is increased in the synovial membrane (SM) of obese KOA patients. Here, we investigated CD5L expression in the SM of these patients. MATERIAL AND METHODS: Ninety KOA patients (26 males, 64 females) were allocated to one of three groups based on body mass index (BMI): normal weight (NW, < 25 kg/m2), overweight (OW, 25-29.99 kg/m2) and obese (OB, ≥ 30 kg/m2), according to the World Health Organization BMI classification (each n = 30). Expression of CD5L in SM among the groups was compared using real-time polymerase chain reaction. To investigate CD5L-expressing cells in SM, CD14+ (macrophage fraction) and CD14- (fibroblast fraction) cells were separated from the SM. RESULTS: CD5L expression was significantly higher in the OB group than in the NW and OW groups (p < 0.001). CD5L expression was observed in the CD14+ fraction but not in the CD14- fraction. CONCLUSIONS: CD5L is highly expressed in the SM of KOA patients with obesity. Further investigation is required to identify the role of CD5L in the relationship between KOA pathology and obesity.

Possible Regulation of bFGF Expression by Mast Cells in Osteoarthritis Patients with Obesity: A Cross-Sectional Study.

PURPOSE: Obesity is associated with the risk of developing knee osteoarthritis (KOA). Furthermore, synovial basic fibroblast growth factor (bFGF) is linked to the severity of KOA. We previously demonstrated that bFGF and mast cell (MC) marker expression were elevated in the synovial tissues (ST) of KOA patients with obesity. However, it remains unclear whether MCs contribute to bFGF expression and regulation. PATIENTS AND METHODS: Radiographically diagnosed KOA patients (n=249) were assigned to groups based on the body mass index (BMI) classifications used by the World Health Organization: normal-weight (NW, BMI <25 kg/m2, n=95), overweight (OW, BMI ≥25 and <30, n=109) and obese (OB, ≥30 kg/m2, n=45). BFGF expression in the ST was examined using quantitative polymerase chain reaction and compared across the BMI groups. Additionally, BFGF and interleukin (IL) 13 expression were examined in freshly extracted MC-rich (THY-1-, CD3-, CD14-, and CD19-) and MC-poor (THY-1+, CD3+, CD14+, or CD19+) fractions from ST. Moreover, regulation of BFGF expression by IL-13 was studied in CD14-negative (fibroblast-rich) and CD14-positive (Mφ-rich) and cells in culture. RESULTS: BFGF expression was significantly higher in OB than in NW patients. Furthermore, although IL13 was significantly higher in the MC-rich than the MC-poor fraction, BFGF expression was comparable. Recombinant human IL-13 stimulated expression of BFGF in synovial fibroblast cells. CONCLUSION: BFGF expression is higher in the ST of KOA patients with obesity. Increased numbers of MCs may contribute to the elevated BFGF expression through IL-13 in KOA patients with obesity.

Differential Synovial CGRP/RAMP1 Expression in Men and Women With Knee Osteoarthritis.

Background Female patients with osteoarthritis report more severe knee pain compared to men. However, the mechanism underlying sex differences in pain remains unclear. We previously found that calcitonin gene-related peptide (CGRP) was expressed in synovial tissue and that this localization may play a role in pain associated with knee osteoarthritis (KOA). Several animal studies have shown that the expression of CGRP and its receptor (receptor activity modifying protein 1, RAMP1) differs by sex. Here, we investigated synovial CGRP and RAMP1 expression in male and female patients with KOA. Methods Synovial tissue (ST) was harvested from male and female subjects (n=30 each) with radiographically confirmed unilateral Kellgren/Lawrence grade 3-4 KOA during total knee arthroplasty. Patients' subjective pain severity was scored on a 0 to 10 cm visual analog scale (VAS). We compared the expression of CGRP and RAMP1 in ST from men and women and examined the correlation between mRNA levels of CGRP and RAMP1 and pain severity. Results Synovial expression of CGRP and RAMP1 was significantly elevated in women compared to men (CGRP, P=0.017; RAMP1, P=0.028). While CGRP expression was positively correlated with pain severity in females (ρ=0.443, P=0.014), no correlation was observed in men (ρ=-0.021, P=0.913). RAMP1 expression was not correlated with pain severity in either men or women (male, ρ=-0.114, P=0.939; female, ρ=-0.047, P=0.807). Conclusion CGRP and RAMP1 expression levels differ between men and women. Differential CGRP levels may suggest the presence of different pain mechanisms in men and women with KOA.

Chylous retroperitoneum following 720 degree anteroposterior-combined corrective surgery for adult spinal deformity with split vertebral fracture subluxation: a case report.

STUDY DESIGN: Clinical case report. PURPOSE: To report the rare case with post-operative chylous retroperitoneum after corrective surgery for adult spinal deformity. METHODS: We present a case of a 73-year-old woman with Parkinson's disease. She sustained a severe split fracture subluxation of the L3 vertebra with AO Spine Thoracolumbar classification type CN2M2, resulting in severe kyphoscoliosis in global alignment. She underwent a two-stage 720-degree anteroposterior-combined corrective surgery with anterior vertebral column resection of L3 and posterior fusion from T4 to the pelvis. On post-operative day 1, milky fluid in the drainage tube was noted, which was diagnosed as post-operative chylous retroperitoneum. RESULTS: Oral intake was discontinued immediately and peripheral parenteral nutrition was started. A low-fat, high-protein diet was started on post-operative day 4, and drainage was removed on day 6. A low-fat diet was continued until 3 months post-operatively, with dietary counselling by a nutritionist. The chylous retroperitoneum resolved without recurrence at the final follow-up evaluation at 3 years. CONCLUSION: Surgeons should recognize this rare complication, which might be induced by direct damage to the lymphatic flow during an operative maneuver anterior to the lumbar vertebral body and indirect damage due to shearing force during correction of a subluxated vertebra, especially in cases with a severe deformity.

Elevated macrophage-inducible C-type lectin expression in the synovial tissue of patients with rheumatoid arthritis.

Rheumatoid arthritis (RA), a systemic autoimmune disease, is known to cause chronic inflammation in synovial joints. A number of inflammatory conditions are associated with stimulation of Clec4e, a macrophage-inducible C-type lectin (MINCLE) and transmembrane pattern recognition receptor that functions in innate immunity. We previously reported MINCLE expression in synovial macrophages isolated from the synovium of osteoarthritis (OA) patients. However, MINCLE expression has not been examined in RA synovial tissue. To examine MINCLE expression in RA patients, synovial tissue specimens were obtained from patients with RA and OA during joint replacement surgery (n = 20 each). Total RNA was extracted from synovial tissue and used to compare MINCLE expression in OA and RA (n = 15 each). We also extracted fresh CD14+ (macrophage-rich) and CD14- cell fractions from synovial tissue and compared MINCLE expression between OA and RA patients (n = 5 each). MINCLE levels in synovial tissue were significantly elevated in RA patients compared to OA patients. MINCLE expression was significantly elevated in the CD14+ fraction compared to the CD14- fraction in both OA and RA patients. Further, while there were no differences in the CD14+ fraction between RA and OA, MINCLE expression in the CD14- fraction was elevated in RA compared to OA. Our findings indicate that MINCLE expression is elevated in the synovium of RA patients and that MINCLE expression in non-macrophage cell fractions may be a key feature of RA.

Acceleration of bone union by in situ-formed hydrogel containing bone morphogenetic protein-2 in a mouse refractory fracture model.

BACKGROUND: An enzymatic crosslinking strategy using hydrogen peroxide and horseradish peroxidase is receiving increasing attention for application with in situ-formed hydrogels (IFHs). Several studies have reported the application of IFHs in cell delivery and tissue engineering. IFHs may also be ideal carrier materials for bone repair, although their potential as a carrier for bone morphogenetic protein (BMP)-2 has yet to be examined. Here, we examined the effect of an IFH made of hyaluronic acid (IFH-HA) containing BMP-2 in promoting osteogenesis in a mouse refractory fracture model. METHODS: Immediately following a fracture procedure, animals either received no treatment (control) or an injection of IFH-HA/PBS or IFH-HA containing 2 µg BMP-2 (IFH-HA/BMP-2) into the fracture site (n = 16, each treatment). RESULTS: Fracture sites injected with IFH-HA/BMP-2 showed significantly greater bone volume, bone mineral content, and bone union compared with sites receiving no treatment or treated with IFH-HA/PBS alone (each n = 10). Gene expression levels of osteogenic markers, Alpl, Bglap, and Osx, were significantly raised in the IFH-HA/BMP-2 group compared to the IFH-HA/PBS and control groups (each n = 6). CONCLUSION: IFH-HA/BMP-2 may contribute to the treatment of refractory fractures.

Arthroscopic Reconstruction of the Anterior Tibiotalar Ligament Using a Free Tendon Graft.

Deltoid ligament injuries account for 5.1% to 15.8% of ankle sprains and occur with concomitant lateral ankle sprains. The anterior tibiotalar ligament (ATTL), located within the deep layer of the deltoid ligament complex, connects the talus and the tibia on the medial side of the ankle and controls ankle eversion and rotation. If conservative treatment for chronic medial ankle instability after an ankle sprain fails, ATTL repair or reconstruction might be necessary. Arthroscopic reconstruction techniques of the lateral ankle ligaments recently have been reported. Here, we describe arthroscopic reconstruction of the ATTL using a free tendon graft (ARATTL). This technique is less invasive than other treatments and results in a more stable medial ankle joint.

Increase in Tryptase and Its Role in the Synovial Membrane of Overweight and Obese Patients with Osteoarthritis of the Knee.

PURPOSE: The mechanisms governing evidence that obesity is a risk factor for osteoarthritis (OA) are not well understood. We previously reported an increase in mast cell (MC) marker expression in the osteoarthritic synovial membrane (SM) of patients with obesity. We hypothesized that an enzyme produced by MC, ß-tryptase, may be increased in the SM of obese patients with knee OA and contribute to synovial inflammation. This study investigated the expression of the ß-tryptase encoding gene, TPSB2, in the SM of obese patients with knee OA and ß-tryptase-mediated regulation of IL-1ß in synovial cells. PATIENTS AND METHODS: A total of 216 patients radiographically diagnosed with knee OA were grouped according to the World Health Organization's body mass index classifications: normal weight (NW; <25 kg/m2), overweight (OW; 25-29.99 kg/m2) and obese (OB; ≥30 kg/m2). Quantitative polymerase chain reaction was conducted to examine TPSB2 expression in the SM among the three groups. We also examined TPSB2 and IL1B expression in MC-rich (CD3-CD14-CD19-CD90-) and MC-poor (CD3+, CD14+, CD19+, or CD90+) fractions freshly isolated from synovial tissue. Further, the effect of ß-tryptase on IL1B expression was investigated in cultured CD14-positive (macrophage-rich fraction) and CD14-negative (fibroblast-rich fraction) cells. RESULTS: There was significantly elevated TPSB2 expression in the OW and OB groups compared to the NW group. The MC-rich fraction had significantly higher levels of TPSB2, CD117 and CD203c than the MC-poor fraction. Recombinant human ß-tryptase stimulated IL1B expression in both the synovial fibroblast and macrophage fractions. CONCLUSION: Obese patients with knee OA showed elevated TPSB2 expression in the SM. Tryptase may play a role in synovial inflammation in obese patients with OA.

Arthroscopic Reconstruction of the Anterior Talofibular Ligament, Lateral Talocalcaneal Ligament, and Calcaneofibular Ligament Using a Triangle-Shaped Tendon Graft (ALC-Triangle).

The lateral talocalcaneal ligament (LTCL) connects the talus and calcaneus on the lateral side of the hindfoot. Although its function remains has not yet been clearly elucidated, the LTCL is thought to be important for the stabilization of the subtalar joint. Ankle sprains often include not only the talocrural joint but also the subtalar joint; therefore, LTCL injuries occur at a certain rate. Moreover, surgeons often encounter and reluctantly dissect the LTCL during arthroscopic anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) reconstruction because the LTCL connects to the ATFL at the talus in 42% of people and connects to the CFL at the calcaneus in 18% of people. As a result, LTCL reconstruction might be necessary for those patients. We describe the arthroscopic reconstruction technique of the ATFL, LTCL, and CFL using a triangle-shaped tendon graft (ALC-triangle). This technique provides a possible advantage of an anatomical and stable talocrural joint and subtalar joint.

Anatomical Arthroscopic Anterior Talofibular Ligament Repair and Reconstruction Using a Free Tendon.

Arthroscopic techniques for anterior talofibular ligament (ATFL) repair and reconstruction have been developed in recent years. We simultaneously performed anatomical arthroscopic ATFL repair and reconstruction using a free tendon graft. The ATFL remnant is carefully dissected only at the footprint of the superior limb of the ATFL, and a bone tunnel is created on each side of the fibula and talus. A soft suture anchor with 2 sets of threads is inserted into the fibular tunnel. One set of threads is used to grab the ATFL remnant via a lasso-loop technique, whereas the other set of threads is used to introduce the ATFL graft. The graft is first fixed with a screw in the talar tunnel. Subsequently, the ATFL remnant and the graft are tightened simultaneously by pulling the 2 sets of suture anchor threads at the fibular tunnel and are fixed with a screw. This technique provides the possible advantages of remnant preservation and promotion of load sharing by the repaired ATFL remnant and the reconstructed ATFL graft.

[A Case of Undifferentiated Intestinal Carcinoma].

Undifferentiated cancer of the small intestine has a poor prognosis and has rarely been reported.We report a case of undifferentiated intestinal carcinoma.A 55-year-old man presented with epigastralgia in December 2018. Blood test results showed a high degree of anemia.Contrast -enhanced abdominal CT showed a small intestinal tumor with a diffuse thickened wall along with multiple liver metastases.Capsule endoscopy revealed a bleeding tumor.It was diagnosed as carcinoma by transhepatic-ultrasound-guided core needle biopsy.Given the preoperative diagnosis of intestinal carcinoma, we resected the tumor along with a part of the small intestine and the enlarged lymph nodes.The pathological diagnosis was undifferentiated intestinal carcinoma.The patient was discharged on the 6th postoperative day after surgery.He was scheduled to receive postoperative chemotherapy.There was no evidence of undifferentiated intestinal carcinoma.Herein, we review case reports from the literature.

Elevated leptin levels induce inflammation through IL-6 in skeletal muscle of aged female rats.

BACKGROUND: Chronic inflammation with aging contributes to sarcopenia. Previous studies have suggested that the accumulation of adipose tissue in skeletal muscle, referred to as intermuscular adipose tissue (IMAT), increases with age and is associated with inflammation. However, the mechanism governing ectopic inflammation in skeletal muscle due to aging is not fully understood. Leptin, an adipocytokine derived from adipose tissue, is an important mediator of inflammatory processes. We examined changes in leptin levels with age and whether leptin contributes to ectopic inflammation. METHODS: To evaluate ectopic inflammation in skeletal muscle, we measured alterations to the expression of inflammatory cytokine genes (Il1b, Il6, and Tnfa) and muscle break down-related gene (MuRF1 and Atrogin1) in the quadricep muscles of young (10 weeks) and aged (48 weeks) female rats using quantitative reverse-transcription polymerase chain reaction (Q-RT-PCR). Histological examination was performed to identify the extent of IMAT. Leptin mRNA and leptin protein expression were examined using Q-RT-PCR and enzyme-linked immunosorbent assay, respectively. The effect of leptin on the mRNA expression of Il1b, Il6, and Tnfa in quadricep muscle-derived cells was also examined by stimulating the cells with 0 (control), 1, or 10 µg/mL rat recombinant leptin using Q-RT-PCR. RESULTS: Aged rats had significantly higher Il6, MuRF1, and Atrogin1 but not Il1b and Tnfa, expression and greater levels of IMAT in their quadricep muscles than young rats. Aged rats also had significantly higher leptin expression and leptin protein concentration in their quadricep muscles than young rats. The addition of exogenous leptin to quadricep muscle-derived cells significantly increased the gene expression of Il1b and Il6 but not Tnfa. CONCLUSIONS: Our results suggest that elevated leptin levels due to aging cause ectopic inflammation through IL-6 in the skeletal muscle of aged rats.

Increase in mast cell marker expression in the synovium of obese patients with osteoarthritis of the knee.

Purpose: While research suggests that obesity is a risk factor for knee osteoarthritis (KOA), the mechanisms are not fully understood. Mast cell (MC) numbers are increased in the osteoarthritic synovium and in the adipose tissue of obese individuals. We hypothesized that MC numbers are increased in the synovium of obese KOA patients. This study investigated MC marker and MC-generated cytokine/growth factor expression in the synovium of obese KOA patients. Patients and methods: Patients radiographically diagnosed with KOA (male: 38, female: 132) were allocated to three groups based on their body mass index (BMI): normal (<25 kg/m2), overweight (25-29.99 kg/m2) and obese (≥30 kg/m2), according to the World Health Organization BMI classification. We used real-time polymerase chain reaction to compare the expression of MC markers (CD117, CD203c) and growth factors/cytokines (FGF2, VEGFA, TNFA, and IL8) in patients' synovium among the groups. Results: CD117 expression was significantly higher in the obese group than in the normal and overweight groups. CD203c and FGF2 expression were higher in the obese group than in the normal group. FGF2 expression levels were significantly correlated with those of CD117 (ρ=0.487) and CD203c (ρ=0.751). Conclusion: MC markers CD117 and CD203c, and FGF2 were highly expressed in the synovium of obese KOA patients. Further investigations are needed to reveal the role of MCs in the relationship between obesity and osteoarthritis pathology.

[Four Cases of Locally Advanced Colorectal Cancer Resected after Neoadjuvant Chemotherapy with mFOLFOX6 plus Bevacizumab].

We describe 4 cases of locally advanced colorectal cancer resected successfully after neoadjuvant chemotherapy(NAC) conducted between April 2015 and August 2016. The NAC with mFOLFOX6 plus bevacizumab was performed after ileostomy for prevention of obstruction, because of tumor invasion into other organs. After chemotherapy, we could perform resection and avoid invasive surgery in either cases.

Isoflurane Induces Transient Impairment of Retention of Spatial Working Memory in Rats.

Postoperative cognitive dysfunction (POCD) occurs in nearly one-third of patients after non-cardiac surgery. Many animal behavior studies have investigated the effect of general anesthesia on cognitive function. However, there have been no studies examining the effects on working memory specifically, with a focus on the retention of working memory. We demonstrate here that isoflurane anesthesia induces deficits in the retention of spatial working memory in rats, as revealed by an increase in isoflurane- induced across-phase errors in the delayed spatial win-shift (SWSh) task with a 30-min delay in an 8-arm radial arm maze on post-anesthesia days (PADs) 1,2,4, and 10. A post-hoc analysis revealed a significant increase in across-phase errors on PAD 1 and recovery on PAD 10 in the isoflurane group. In contrast, within-phase errors independent of the retention of working memory were unaffected by isoflurane. These results demonstrate that isoflurane anesthesia transiently impairs the retention of spatial working memory in rats.

Osteochondritis dissecans of the fourth proximal interphalangeal joint in a Japanese drummer.

We report a rare case of osteochondritis dissecans involving the fourth proximal interphalangeal joint in a young Japanese drummer. We treated it successfully with the removal of loose body and drilling of the donor site.