Fracture of a persistent olecranon physis in an adult

A persistent olecranon physis is relatively rare; a fracture through the persistent olecranon physis in an adult is particularly rare. Little is known about the pathology of this disease. We report a case of a 36-year-old man presenting with right elbow pain after he had slipped and hit his elbow, with a history of a persistent symptomatic olecranon physis when he was a junior high school baseball player. He had been diagnosed with a fracture through a persistent olecranon physis by another doctor. Ten weeks after the injury, an iliac autograft was inserted and internal fixation was achieved with Kirschner wires and a figure-of-eight tension band in our hospital. Histologically, a fracture passed through the persistent physis cartilage and degeneration of the remnant of the physis was observed. The remnant of the physis at the olecranon side had not been replaced by new bone, though the physis at the distal ulnar was nearly replaced by new bone. The patient returned to work without experiencing pain or limitation in the range of motion 6 months after the operation. Radiographic evidence of bone union was seen after removal of internal fixation at the 13-month follow-up

Elbow injuries in young baseball players

Among the１６０５participants,３１．１％ reported episodes of elbow pain. Limits of７０pitches per day may protect elbow injuries in younger than １２ years old pitchers. Even in the asymptomatic early stage capitellar osteochondritis dissecans（OCD）, it is desirable to stop throwing until the healing is observed. Arthroscopic debridement of capitellar OCD resulted in a functional elbow with subjective symptom relief for the majority of patients

Capitellar OCD

Osteochondritis dissecans (OCD) of the capitellum is a leading cause of elbow disability in adolescent baseball players. Previous studies have not found an association of player position with capitellar OCD. Elbow pain and a longer playing history might be related to progression of capitellar OCD but do not in themselves increase the risk of development of the condition. The cause of capitellar OCD is likely to include a combination of repetitive microtrauma and internal factors, such as ischemia and genetic predisposition. A combination of radiography, computed tomography, magnetic resonance imaging, and ultrasonography have aided our understanding of the pathology of capitellar OCD. Screening using ultrasonography enables early detection and provides an opportunity for successful conservative treatment. Treatment has conventionally included both operative and nonoperative measures based on the stage and size of the lesion, skeletal maturity, subjective symptoms, and structural integrity of the cartilage. Early-stage lesions respond better to nonoperative treatment than those in more advanced stages. Operative indications include persistent symptoms despite nonoperative treatment, symptomatic loose bodies, and displacement or detachment of fragments

Reaction dynamics analysis of an E. coli protein translation system by computational modeling

A single enzymatic reaction can often be described by Michaelis-Menten kinetics, but once reactions are connected to one other, it becomes difficult to understand and capture a complete description of the reaction dynamics due to its high dimensionality. To elucidate the dynamic features of a biologically relevant large-scale reaction network, we constructed a computational model of minimal protein synthesis consisting of 241 components and 968 reactions that synthesize the Met-Gly-Gly (MGG) peptide based on an Escherichia coli-based reconstituted in vitro translation (IVT) system [1]. We performed a simulation using parameters collected primarily from the literature and found that the rate of MGG peptide synthesis becomes nearly constant in minutes, thus achieving a steady-state similar to experimental observations. In addition, concentration changes to 70% of the components, including intermediates, reached a plateau in a few minutes. However, the concentration change of each component exhibits several temporal plateaus, or a quasi-stationary state (QSS), before reaching the final plateau. To understand the complex dynamics, we focused on whether the components reached a QSS, mapped the arrangement of components in a QSS in the entire reaction network structure and investigated time-dependent changes. We found that components in a QSS form clusters that grow over time but not in a linear fashion and that this process involves the collapse and regrowth of clusters before the formation of a final large single cluster. These observations might commonly occur in other large-scale biological reaction networks. This developed analysis might be useful for understanding large-scale enzymatic reactions, thereby extracting the characteristics of the reaction network, including phase transitions. As the reconstituted IVT has been used for various applications inducing directed evolution of membrane proteins [2,3], the developed computational model might be useful in further enhancement of the yield of synthesized proteins using the reconstituted IVT. Please click Additional Files below to see the full abstract

Effects of ribosomes on the kinetics of Qβ replication

AbstractBacteriophage Qβ utilizes some host cell translation factors during replication. Previously, we constructed a kinetic model that explains replication of long RNA molecules by Qβ replicase. Here, we expanded the previous kinetic model to include the effects of ribosome concentration on RNA replication. The expanded model quantitatively explained single- and double-strand formation kinetics during replication with various ribosome concentrations for two artificial long RNAs. This expanded model and the knowledge obtained in this study provide useful frameworks to understand the precise replication mechanism of Qβ replicase with ribosomes and to design amplifiable RNA genomes in translation-coupling systems

Effect of the angiotensin-converting enzyme inhibitor imidapril on reactive hyperemia in patients with essential hypertension: relationship between treatment periods and resistance artery endothelial function

AbstractOBJECTIVESThe purpose of this study was to evaluate the effects of the angiotensin-converting enzyme (ACE) inhibitor imidapril and the calcium antagonist amlodipine on endothelial function before and after 2, 4, 8, 12, 24 and 48 weeks of treatment.BACKGROUNDThere are limited data on whether and how long endothelial function is improved after initiation of ACE inhibitor treatment and how the grade of endothelial function further progresses after improvement of endothelial dysfunction in patients with essential hypertension.METHODSThe forearm blood flow (FBF) was measured in 25 patients with essential hypertension and in 25 normotensive subjects by using strain-gauge plethysmography during reactive hyperemia (RH) (280 mm Hg for 5 min) and after sublingual administration of nitroglycerin (NTG, 0.3 mg).RESULTSThe FBF of patients with essential hypertension during RH was significantly less than that of normotensive subjects. The increase in FBF after sublingual NTG was similar in both groups. Both imidapril (n = 13) and amlodipine (n = 12) significantly reduced systolic blood pressure and diastolic after eight weeks of treatment from the pretreatment values. Forearm vascular resistance was significantly decreased after two weeks of treatment. Imidapril significantly augmented RH after 12 weeks of treatment from the pretreatment values (31.6 ± 5.7 to 38.2 ± 6.0 ml/min per 100 ml tissue, p < 0.05), whereas amlodipine did not alter RH for each treatment period. The ability of imidapril to improve RH was maintained throughout the 48-week treatment period. There was no significant difference in RH at 12, 24 and 48 weeks. The increase in FBF after sublingual administration of NTG was similar in all treatment periods for the two groups. The infusion of NG-monomethyl-L-arginine, a nitric oxide (NO) synthase inhibitor, abolished the enhancement of RH in hypertensive patients treated with imidapril.CONCLUSIONSThese findings suggest that the ACE inhibitor imidapril augments RH after 12 weeks of treatment in patients with essential hypertension and that this ACE inhibitor-induced augmentation of RH may be due to an increase in NO

Follow-up of Osteochondral LFC Injury

Chondral and osteochondral injuries of the femoral condyle are rare, and relatively few cases have been reported. Therefore, the mechanism, treatment, and findings on follow-up of these injuries are not well described. Here, we report the case of an adolescent basketball player who sustained a sports-related traumatic osteochondral injury of the lateral femoral condyle. He was treated with open reduction and internal fixation with the pull-out suture technique. Two years later, he was able to resume sporting activities at his pre-injury level with no symptoms. Magnetic resonance imaging (MRI) confirmed survival of the fixed osteochondral fragment and restoration of the congruity of the articular cartilage with no sign of delamination. This report describes the clinical outcome of this osteochondral injury of the lateral femoral condyle as seen on MRI at the 2-year follow-up and discuss the mechanism and treatment of this injury

Early changes in muscle atrophy and muscle fiber type conversion after spinal cord transection and peripheral nerve transection in rats

BACKGROUND: Spinal cord transection and peripheral nerve transection cause muscle atrophy and muscle fiber type conversion. It is still unknown how spinal cord transection and peripheral nerve transection each affect the differentiation of muscle fiber type conversion mechanism and muscle atrophy. The aim of our study was to evaluate the difference of muscle weight change, muscle fiber type conversion, and Peroxisome proliferator-activated receptor-γ coactivatior-1α (PGC-1α) expression brought about by spinal cord transection and by peripheral nerve transection. METHODS: Twenty-four Wistar rats underwent surgery, the control rats underwent a laminectomy; the spinal cord injury group underwent a spinal cord transection; the denervation group underwent a sciatic nerve transection. The rats were harvested of the soleus muscle and the TA muscle at 0 week, 1 week and 2 weeks after surgery. Histological examination was assessed using hematoxylin and eosin (H&E) staining and immunofluorescent staing. Western blot was performed with 3 groups. RESULTS: Both sciatic nerve transection and spinal cord transection caused muscle atrophy with the effect being more severe after sciatic nerve transection. Spinal cord transection caused a reduction in the expression of both sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection produced an increase in expression of sMHC protein and PGC-1α protein in the soleus muscle. The results of the expression of PGC-1α were expected in other words muscle atrophy after sciatic nerve transection is less than after spinal cord transection, however muscle atrophy after sciatic nerve transection was more severe than after spinal cord transection. CONCLUSION: In the conclusion, spinal cord transection diminished the expression of sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection enhanced the expression of sMHC protein and PGC-1α protein in the soleus muscle

Platelet-rich plasma does not reduce skeletal muscle fibrosis after distraction osteogenesis

Background: Skeletal muscle fibrosis caused by an increase in collagen deposition often occurs after distraction osteogenesis. Although studies are available reporting the effects of platelet-rich plasma (PRP) on tissue healing following injury, current findings remain controversial. This study focused on determining whether PRP reduces skeletal muscle fibrosis caused by distraction osteogenesis. Methods: Tibial osteotomies were performed on 8-week-old wild type mice, and tibiae were distracted at a rate of 0.42 mm/day for 2 weeks, starting 1 week after osteotomy. Immediately after distraction was completed (3 weeks after osteotomy), PRP or phosphate buffered saline (as a sham) was injected into the gastrocnemius (GC) muscle. The GC muscles were harvested and analyzed. Results: The amount and area of collagenous tissue increased in both the PRP and control groups following distraction osteogenesis, but the changes were not significantly different between both groups at all time points (p = 0.89, 0.45, 0.33 and 0.52 at 4, 6, 8 and 10 weeks). Conclusion: From this study, our results suggest that PRP did not significantly reduce skeletal muscle fibrosis due to distraction osteogenesis