Results of microfracture in the osteoarthritic knee with focal full-thickness articular cartilage defects and concomitant medial meniscal tears.

PURPOSE: To evaluate the efficacy of arthroscopic microfracture in patients with focal full-thickness cartilage defects in the osteoarthritic knee. MATERIALS AND METHODS: Seventy-six patients were enrolled in this study. They were divided into group I (n=38) who underwent microfracture plus meniscectomy and group II (n=38) who underwent only meniscectomy. Clinical and radiological evaluations were performed. RESULTS: At the time of the three-year follow-up, a total of five failures (6.6%) were reported: four patients in group I and one in group II. The two groups showed no significant difference in the Lysholm score, the Tegner activity score and the visual analog pain scale score at three years after surgery. However, at the time of the three-month follow-up, group II showed significantly more improvement in the Tegner activity and the visual analog pain score compared with group I. CONCLUSIONS: In the osteoarthritic knee, additional microfracture did not confer any additional benefit to meniscectomy.

Lateral release and medial plication for recurrent patella dislocation.

PURPOSE: This study aims to report the long-term results of lateral release and medial plication in patients with recurrent patellar dislocation. METHODS: In this study, 31 patients who underwent surgery for recurrent patellar dislocation were retrospectively reviewed between 1994 and 2004. Among the 31 patients were 12 male and 19 female patients. The average age was 23.9 ± 4.8 years, and the mean follow-up period was 11.6 ± 2.4 years. RESULTS: Three patients had postoperative dislocations. The mean Kujala score significantly improved from 57.5 ± 13.2 points preoperatively to 89.2 ± 8.7 points at the final follow-up (P < 0.0001). The median Tegner activity score significantly improved from 3 (range, 1-5) at preoperative examination to 7 (range, 3-9) at the final follow-up (P < 0.0001). Ten patients were rated as excellent, 18 as good, 2 as fair, and 1 as poor. The congruence angle improved from 16.5° ± 3.0° to -2.8° ± 2.7°, and the lateral patellofemoral angle improved from -4.2° ± 1.9° to 8.2° ± 2.5°. There was no case of osteoarthritis at the final follow-up. CONCLUSIONS: Percutaneous lateral release and medial plication showed satisfactory results with limited morbidity in the long-term follow-up. This traditional method remains a simple and effective surgical procedure for recurrent patellar dislocation. LEVEL OF EVIDENCE: Therapeutic, Level IV.

Ankle valgus deformity secondary to proximal migration of the fibula in tibial lengthening with use of the Ilizarov external fixator.

BACKGROUND: Ankle valgus deformity secondary to proximal migration of the fibula following an Ilizarov tibial lengthening has not been discussed in detail in the literature. The purposes of this study were to determine the underlying mechanism of and to identify factors associated with proximal migration of the fibula that caused ankle valgus deformity after an Ilizarov tibial lengthening. METHODS: We reviewed the outcome of seventy-four bilateral Ilizarov tibial lengthenings for short stature in thirty-seven patients. The mean age at the time of surgery was 21.7 years (range, thirteen to thirty-one years), and the mean duration of follow-up was forty-five months. Proximal migration of the fibula was assessed with changes in the malleolar tip distance. A valgus change of ≥ 5° in the tibiotalar angle was regarded as ankle valgus deformity following tibial lengthening. RESULTS: The average length gain was 6.9 cm (range, 4.7 to 11.5 cm), and the average lengthening index was 1.5 mo/cm. Valgus deformity developed in six ankles (8%) and fibular nonunion developed in ten (14%). Proximal migration of the lateral malleolus of ≥ 5 mm was related to valgus talar tilting. Bifocal tibial lengthening, rapid distraction rate of the fibula (>1 mm per day), and development of a fibular nonunion were factors associated with proximal migration of the distal end of the fibula of ≥ 5 mm, which suggests that regenerated bone of poor quality in the distraction gap may cause proximal migration of the distal end of the fibula following tibial lengthening. CONCLUSIONS: Proximal migration of the distal end of the fibula following tibial lengthening may occur even with the use of an Ilizarov ring fixator. This migration seems to be caused by collapse of regenerated bone of poor quality or fibular nonunion. Proximal migration of ≥ 5 mm is associated with the risk of valgus talar tilting. Surgeons should consider earlier intervention with bone-grafting if there are conditions that compromise regenerated bone formation in the fibular distraction gap, such as can occur with extensive tibial lengthening by bifocal corticotomy.

Development of fluorescent glucose bioprobes and their application on real-time and quantitative monitoring of glucose uptake in living cells.

We developed a novel fluorescent glucose bioprobe, GB2-Cy3, for the real-time and quantitative monitoring of glucose uptake in living cells. We synthesized a series of fluorescent glucose analogues by adding Cy3 fluorophores to the α-anomeric position of D-glucose through various linkers. Systematic and quantitative analysis of these Cy3-labeled glucose analogues revealed that GB2-Cy3 was the ideal fluorescent glucose bioprobe. The cellular uptake of this probe competed with the cellular uptake of D-glucose in the media and was mediated by a glucose-specific transport system, and not by passive diffusion. Flow cytometry and fluorescence microscopy analyses revealed that GB2-Cy3 is ten times more sensitive than 2-NBDG, a leading fluorescent glucose bioprobe. GB2-Cy3 can also be utilized for the quantitative flow cytometry monitoring of glucose uptake in metabolically active C2C12 myocytes under various treatment conditions. As opposed to a glucose uptake assay performed by using radioisotope-labeled deoxy-D-glucose and a scintillation counter, GB2-Cy3 allows the real-time monitoring of glucose uptake in living cells under various experimental conditions by using fluorescence microscopy or confocal laser scanning microscopy (CLSM). Therefore, we believe that GB2-Cy3 can be utilized in high-content screening (HCS) for the discovery of novel therapeutic agents and for making significant advances in biomedical studies and diagnosis of various diseases, especially metabolic diseases.

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<13°) and high group (39 knees with a PTS≥13°). 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 11.4°±3.0°, whereas that in patients without medial meniscal tears was 9.8°±2.4°. The incidence of meniscal tears was 57.8% (78/135) in the low group and 89.7% (35/39) in the high group (p<0.001). CONCLUSIONS: Our data demonstrate that PTS≥13° 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.

Ligament reconstruction in congenital absence of the anterior cruciate ligament: a case report.

Congenital absence of the cruciate ligament is an extremely rare condition that was first reported in Giorgi's radiographic study in 1956. The authors report on a case of anterior cruciate ligament reconstruction performed on a 21-year-old female patient with congenital anterior cruciate ligament absence. We also discuss radiographic evidence that could provide clues to the congenital absence and possible difficulties that may be encountered during surgery with a review of the relevant literature.

Magnetic resonance imaging evidence of meniscal extrusion in medial meniscus posterior root tear.

PURPOSE: The purpose of this study was to evaluate the relation between meniscal extrusion on magnetic resonance imaging (MRI) and tearing of the posterior root of the medial meniscus, as well as to understand the relation between meniscal extrusion and chondral lesions. METHODS: From January 2007 to December 2008, 387 consecutive cases of medial meniscal tears were treated arthroscopically. Of these cases, 248 (64.1%) with MRI were reviewed. Arthroscopic findings were reviewed for the type of tear and medial compartment cartilage lesion. Root tear was defined as a radial tear in the posterior horn of the medial meniscus near the tibial spine (i.e., within 5 mm of the root attachment). An MRI scan of the knee was used to evaluate the presence and extent of meniscal extrusion. Meniscal extrusion of 3 mm or greater was considered pathologic. Arthroscopic findings were compared with respect to the extent of meniscal extrusion. RESULTS: There were 98 male patients and 150 female patients. The mean age was 53.5 years (range, 15 to 81 years). The results showed 127 cases (51.2%) in which the medial meniscus had meniscal extrusion of 3 mm or greater. Posterior root tears were found in 66 (26.6%) of the 248 knees. The mean meniscal extrusion in patients with root tear was 3.8 ± 1.4 mm, whereas the mean extrusion of those who had no root tear was 2.7 ± 1.3 mm. We found an association between pathologic meniscal extrusion and root tear (P < .001). Meniscal extrusion showed a low positive predictive value (39%) and specificity (58%) with regard to the meniscal root tear. Meniscal extrusion was also significantly correlated with severity of chondral lesions (P < .001). CONCLUSIONS: Considerable extrusion (≥3 mm) can be associated with tearing of the medial meniscus root and chondral lesion of the medial femoral condyle. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

In vitro trans-differentiation of rat mesenchymal cells into insulin-producing cells by rat pancreatic extract.

Recent reports have suggested that mesenchymal cells derived from bone marrow may differentiate into not only mesenchymal lineage cells but also other lineage cells. There is possibility for insulin-producing cells (IPCs) to be differentiated from mesenchymal cells. We used self-functional repair stimuli of stem cells by partial injury. Rat pancreatic extract (RPE) from the regenerating pancreas (2 days after 60% pancreatectomy) was treated to rat mesenchymal cells. After the treatment of RPE, they made clusters like islet of Langerhans within a week and expressed four pancreatic endocrine hormones; insulin, glucagon, pancreatic polypeptide, and somatostatin. Moreover, IPCs released insulin in response to normal glucose challenge. Here we demonstrate that the treatment of RPE can differentiate rat mesenchymal cells into IPCs which can be a potential source for the therapy of diabetes.

Proteome analysis of rat pancreas induced by pancreatectomy.

The previous study demonstrated that the streptozotocin (STZ)-induced diabetic mice can be cured by injecting the regenerating pancreatic extract (RPE) of the partially pancreatectomized Wistar-Kyoto rats. In this study, to characterize the complex pattern of protein expression in RPE, the proteins of altered expression level after the pancreatectomy were identified by 2-dimensional electrophoresis (2-DE) and mass spectrometry. Of 76 significantly up- or down-regulated protein spots, 61 were identified by MALDI-TOF/MS. Moreover, the whole RPE was fractionated into 4 groups using an anion-exchange chromatography and each fraction's cell proliferating activity was measured by MTT assay. Compared to the normal pancreatic extract, fraction 3 and 4 of RPE showed the maximal cell proliferating activity. On 2-DE of 3 and 4 fractions, a total of 10 spots, which are differentially expressed after the pancreatectomy, were identified by MS/MS. Of these identified proteins, Reg III which might be functionally associated with well known regenerating factor (Reg I) was found. Taken together, our results demonstrated that the differential protein expression associated with pancreas regeneration could be sought by 2-DE and mass spectroscopy and suggested that the pre-fractionation method combined with in vitro cell proliferation assay is effectively used to pinpoint the active components for pancreas regeneration.

Insulin microcrystal suspension as a long-acting formulation for pulmonary delivery.

Pulmonary delivery provides the most promising non-parenteral route of insulin administration. Insulin was used as a model protein to demonstrate the feasibility of using protein crystals for the pulmonary delivery of a sustained-release protein drug formulation. Insulin microcrystals with a mean diameter of 3 microm were prepared using a seed zone method. The yield of crystallization was very high (95.8 +/- 0.97%), and the microcrystals were recovered with high efficiency (>98%) by centrifugation. Morphological examination using scanning electron microphotography showed the microcrystals to be of a homogeneous rhombohedral shape, with some rhombus forms, without aggregates. After the administration of 32 U/kg of the microcrystal suspension to STZ-induced diabetic SD rats by intratracheal instillation, the blood glucose levels were reduced and hypoglycemia was prolonged over 13 h, as compared to the insulin solution. The percent minimum reductions of the blood glucose concentration (% MRBG) produced by the microcrystal suspension and insulin solution reached 36.5 and 37.2%, respectively, of the initial level, and the percent total reductions in blood glucose (% TRBG(13 h)) were 34.4 and 25.0%, respectively. In the case of inhalation using a sieve-type ultrasonic nebulizer, the % MRBG produced by the microcrystal suspension and insulin solution were 21.7 and 26.3%, respectively, of the initial level, and the % TRBG(13 h) were 66.7 and 58.4%, respectively. However, the hypoglycemic effects of the microcrystal suspension were prolonged over 7 h, which compares favorably with the insulin solution (P<0.5 by unpaired t-test). These results could be attributed to the sustained-release of insulin from the microcrystals, which were deposited widely throughout the entire lung.

Isolation of ethanol-induced genes in pancreatic beta-cells by representational difference analysis (RDA).

Recent epidemiological studies suggest that alcohol consumption is one of the risk factors leading to type 2 diabetes, but the direct effect of ethanol on beta-cell gene expression is not known. Here, using cDNA RDA method, we isolated 43 ethanol-induced genes in pancreatic beta-cells, and confirmed their differential expression by Northern blot or semi-quantitative RT-PCR. These genes were further categorized by the functional criteria based on the published data; Translation, Transcription, Metabolism, Signal transduction, Transport, Structure, Cytoskeleton, Regulation, or Putative/Unknown genes. The effects of each gene on beta-cell function need to be further investigated, however, the present data strongly suggest that these genes might be related to the metabolic alterations caused by ethanol as indicated in earlier study. In particular, RPS3 gene expression was increased by ethanol, glucosamine, and cytokines, implying that ethanol might decrease the metabolic activity by oxidative stress in beta-cells. Therefore, cloning of these genes in full-length and the detailed studies of each gene on beta-cell functions might provide clues on the pathophysiology of type 2 diabetes caused by alcohol.

Characterization of streptozotocin-induced diabetic rats and pharmacodynamics of insulin formulations.

Morphological and functional changes of rat pancreatic islets caused by administration of streptozotocin (STZ) and the bioavailability of insulin formulations administered to STZ-induced diabetic rats with fasting (12 h) or non-fasting were investigated. Islets isolated from normal rats maintained a good three-dimensional structure and the islet yield was 962.5+/-86.5 islet equivalent number (IEQ, islets converted to an average diameter of 150 microm). In the diabetic group (>500 mg/ml blood glucose), the islet yield was only 44.4+/-8.3 IEQ and the islet was severely damaged. The minimum reduction of blood glucose of each formulation, such as insulin solution, microcrystal, and insulin microcrystal capsule, was shown to be 11.3, 11.0, and 16.3 mg/dl, respectively, at 6 h in fasting with diabetic rats. These results indicated that the administration of insulin formulations to the fasting groups increased the severe hypoglycemic effect of insulin action more than in non-fasting diabetic rats. The diabetic rat with fasting has a regulatory disorder in maintaining the blood glucose level. Accordingly, the validity of pharmacological availability as an optimal modeling of insulin formulations is best in non-fasting STZ-induced diabetic rats.

Enhancement of mouse pancreatic regeneration and HIT-T15 cell proliferation with rat pancreatic extract.

In this study, the effects of rat pancreatic extract (RPE) on regeneration of impaired mouse pancreas and proliferation of beta-cell line (HIT-T15) were investigated. RPE from the regenerating pancreas (2 days after 60% pancreatectomy) was treated to cure streptozotocin (STZ) induced diabetes in BALB/c mice. RPE-treated BALB/c mice for 21 consecutive days became euglycemic by day 30 and remained normoglycemic during a 150 day follow-up. Saline treated mice remained hyperglycemic sustained uncontrolled hyperglycemia. Islet neogenesis was observed in RPE-treated mice and confirmed by use of immunocytochemistry. Morphometric analysis of pancreas in reverted RPE-treated mice showed a new population of small islets compared with saline controls and an increased islet number. When HIT-T15 cells were treated with RPE, HIT-T15 cell proliferation and insulin secretion increased with increases in the RPE concentration. These results imply that RPE have the regeneration factors and help in the cure of diabetes.

Microcrystallization of indomethacin using a pH-shift method.

This study developed a microcrystallization process for indomethacin, a nonsteroidal anti-inflammatory drug (NSAID), using a pH-shift method in aqueous solution. The physicochemical properties of the microcrystals produced were similar to those of the standard crystalline powder in X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR) analyses, except for a lower XRD peak height and a slightly lower melting temperature (Tm) (1.5 degrees C). Phase contrast microscopy and scanning electron microscopy (SEM) showed that the indomethacin microcrystals were plate-like with a uniform size distribution (mean diameter =10.4+/-0.4 microm). In the initial phase, the dissolution rate of the indomethacin microcrystals was about 2.2 times higher than that of the standard crystalline powder. The biological activity of the indomethacin microcrystals was about 20% higher than that of the standard crystalline powder in their ability to inhibit the proliferation of colon cancer cells (HT-29).

Ethanol decreases basal insulin secretion from HIT-T15 cells.

Various epidemiological studies suggest that alcohol intake is one of the risk factors leading to type II or non-insulin-dependent diabetes mellitus (NIDDM), but the effect of alcohol on beta-cell function remains unexplored. To study the mechanism of the diabetogenic action of ethanol, we investigated the effect of ethanol on beta-cell functions using a single clonal beta-cell line, HIT-T15 cells. When HIT cells were treated with ethanol, the metabolic activity judged by MTT assay was inhibited in dose- and time dependent manners, but cytotoxicity was not observed. Ethanol also inhibited basal insulin secretion by 30% compared to the untreated control. However, glucose-stimulated insulin secretion was not impaired by ethanol although the basal insulin secretion was inhibited. These results imply that ethanol exert beta-cells to overwork in order to compensate inhibition of the basal secretion. This finding may at least in part explain the diabetogenic action of ethanol.