Medial Meniscal Tears in Anterior Cruciate Ligament-Deficient Knees: Effects of Posterior Tibial Slope on Medial Meniscal Tear

PURPOSE: To evaluate the incidence of meniscal tears in patients with chronic anterior cruciate ligament (ACL)-deficient knees, and to determine the influence of posterior tibial slope (PTS) on medial meniscal tears in ACL-deficient knees. MATERIALS AND METHODS: We reviewed 174 patients (174 knees) with a mean age of 30.7 years who underwent ACL reconstruction for chronic ACL tears. We divided the patients into two groups: low group (135 knees with a PTS or =13degrees). RESULTS: The incidence of medial meniscus tears was 44% (77/174), and that of lateral meniscus tears was 35% (61/174). The mean PTS in patients with medial meniscal tears was 11.4degrees+/-3.0degrees, whereas that in patients without medial meniscal tears was 9.8degrees+/-2.4degrees. The incidence of meniscal tears was 57.8% (78/135) in the low group and 89.7% (35/39) in the high group (p or =13degrees is a risk factor for secondary medial meniscal tears in ACL-deficient knees. So, we suggest that PTS is one of the considerations for determining early ACL reconstruction to prevent secondary meniscal tears.ope

Mesenteric extraskeletal osteosarcoma with telangiectatic features: a case report

<p>Abstract</p> <p>Background</p> <p>Extraskeletal osteosarcoma is a rare malignant mesenchymal tumor, with a predominant occurrence in the extremities. Only two cases of mesenteric extraskeletal osteosarcoma have been documented. We describe an unusual case of extraskeletal osteosarcoma with telangiectatic features occurring in the mesentery.</p> <p>Case presentation</p> <p>A 67-year-old male presented with blood-tinged stool of 1-month's duration. On colonoscopy, a solid mass was detected protruding from the colon wall. Computed tomography showed a 15 × 9.7 cm heterogeneously enhancing mass, with mottled calcification and a cystic portion, occupying the left upper quadrant of the abdominal cavity. Curative resection of the tumor was performed, and the excised tumor was composed of large multilocular cysts containing old hematomas and necrotic debris. The histology revealed an osteosarcoma showing osteoid formation and blood-filled spaces lined with atypical cells. Despite postoperative chemotherapy, he developed a recurrent peritoneal mass and multiple lung metastases 3 months postoperatively.</p> <p>Conclusion</p> <p>Given the rarity of cases of mesenteric extraskeletal osteosarcoma, its biologic behavior at this location remains to be determined. However, extraskeletal osteosarcoma with telangiectatic features is an uncommon entity to be recognized because of the possible fatal outcome related to the tumors.</p

pH-responsive high-density lipoprotein-like nanoparticles to release paclitaxel at acidic pH in cancer chemotherapy

Jae-Yoon Shin,1,* Yoosoo Yang,1,* Paul Heo,1 Ji-Chun Lee,1 ByoungJae Kong,1 Jae Youl Cho,1 Keejung Yoon,1 Cheol-Su Shin,2 Jin-Ho Seo,3 Sung-Gun Kim,4 Dae-Hyuk Kweon11Department of Genetic Engineering, College of Biotechnology and Bioengineering, and Center for Human Interface Nano Technology, Sungkyunkwan University, 2APTech Research Center, Suwon, 3Department of Agricultural Biotechnology, Seoul National University, Seoul, 4Department of Biomedical Science, Youngdong University, Chungbuk, South Korea*These authors contributed equally to this workBackground: Nanoparticles undergoing physicochemical changes to release enclosed drugs at acidic pH conditions are promising vehicles for antitumor drug delivery. Among the various drug carriers, high-density lipoprotein (HDL)-like nanoparticles have been shown to be beneficial for cancer chemotherapy, but have not yet been designed to be pH-responsive.Methods and results: In this study, we developed a pH-responsive HDL-like nanoparticle that selectively releases paclitaxel, a model antitumor drug, at acidic pH. While the well known HDL-like nanoparticle containing phospholipids, phosphatidylcholine, and apolipoprotein A-I, as well as paclitaxel (PTX-PL-NP) was structurally robust at a wide range of pH values (3.8&amp;ndash;10.0), the paclitaxel nanoparticle that only contained paclitaxel and apoA-I selectively released paclitaxel into the medium at low pH. The paclitaxel nanoparticle was stable at physiological and basic pH values, and over a wide range of temperatures, which is a required feature for efficient cancer chemotherapy. The homogeneous assembly enabled high paclitaxel loading per nanoparticle, which was 62.2% (w/w). The molar ratio of apolipoprotein A-I and paclitaxel was 1:55, suggesting that a single nanoparticle contained approximately 110 paclitaxel particles in a spherical structure with a 9.2 nm diameter. Among the several reconstitution methods applied, simple dilution following sonication enhanced the reconstitution yield of soluble paclitaxel nanoparticles, which was 0.66. As a result of the pH responsiveness, the anticancer effect of paclitaxel nanoparticles was much more potent than free paclitaxel or PTX-PL-NP.Conclusion: The anticancer efficacy of both paclitaxel nanoparticles and PTX-PL-NP was dependent on the expression of scavenger receptor class B type I, while the killing efficacy of free paclitaxel was independent of this receptor. We speculate that the pH responsiveness of paclitaxel nanoparticles enabled efficient endosomal escape of paclitaxel before lysosomal break down. This is the first report on pH-responsive nanoparticles that do not contain any synthetic polymer.Keywords: pH responsiveness, nanoparticle, apolipoprotein A-I, paclitaxe

CHANGES IN MUSCLE ACTIVITY PATTERN IN LOWER LIMB EXTREMITY DURING PEDALLING BY SADDLE HEIGHT

As a preliminary study for a preferential saddle height for cyclist, muscle activity pattern in lower limb extremity between preferred and higher saddle height during pedalling was compared. Seven cyclists performed 3 min sub-maximal pedalling under two different saddle heights. Range of motion (ROM) of muscle length, onset-timing of muscle activity, and amount of muscle activity in biceps femoris (BF), vastus lateralis (VL), gastrocnemius (GM), and tibialis anterior muscles (TA) were used to compare changes in muscle activity pattern due to saddle height. Results showed that there was a significant difference in ROM of VL and that of TA (

Improved elimination of motion artifacts from a photoplethysmographic signal using a Kalman smoother with simultaneous accelerometry

A photoplethysmography (PPG) signal provides very useful information about a subject's hemodynamic status in a hospital or ubiquitous environment. However, PPG is very vulnerable to motion artifacts, which can significantly distort the information belonging to the PPG signal itself. Thus, the reduction of the effects of motion artifacts is an important issue when monitoring the cardiovascular system by PPG. There have been many adaptive techniques to reduce motion artifacts from PPG signals. In the present study, we compared a method based on the fixed-interval Kalman smoother with the usual adaptive filtering algorithms, e.g. the normalized least mean squares, recursive least squares and the conventional Kalman filter. We found that the fixed-interval Kalman smoother reduced motion artifacts from the PPG signal most effectively. Therefore, the use of the fixed-interval Kalman smoother can reduce motion artifacts in PPG, thus providing the most reliable information that can be deduced from the reconstructed PPG signals.This study was supported by the IT R&D program of MKE/KEIT (2009-S-014-01, On the development of Sensing-Based Emotive Service Mobile Handheld Devices) and also by a grant from the Institute of Medical System Engineering in the GIST, Korea

Vortex solutions of a Maxwell-Chern-Simons field coupled to four-fermion theory

We find the static vortex solutions of the model of Maxwell-Chern-Simons gauge field coupled to a (2+1)-dimensional four-fermion theory. Especially, we introduce two matter currents coupled to the gauge field minimally: the electromagnetic current and a topological current associated with the electromagnetic current. Unlike other Chern-Simons solitons the N-soliton solution of this theory has binding energy and the stability of the solutions is maintained by the charge conservation laws.Comment: 7 pages, harvmac, To be published in Phys. Rev. D5