Estimation of tangential finger force and its relationship with the spin rate of pitched fastball.

This study had two objectives: (a) estimating the force exerted by pitchers in generating the spin of a fastball and (b) examining the factors that influence the spin rate of a fastball. Thirteen baseball pitchers participated in this study. The resultant forces acting on the ball was measured using an accelerometer placed in the baseball, and the force was decomposed into two frequency components using maximal overlap discrete wavelet transform. The intraclass correlation coefficients (ICC) between the integration of the high-frequency component of acceleration and the variation in the tangential velocity was high (ICC(3,1) = 0.64 ± 0.16). The ball spin per velocity (SPV) was significantly correlated with the peak value of the high-frequency component of the resultant forces (r = 0.66, p < 0.01). The high-frequency component of the resultant forces reflected the force in the tangential direction, and this force was one of the factors that adjusted the ball spin rate. The SPV did not significantly correlate with the peak value of the low-frequency component of the resultant forces (r = 0.50, p > 0.05). This indicates that decomposing the resultant forces into two frequency components is necessary to investigate the function of the finger during pitching.

Peak Muscle and Joint Contact Forces of Running with Increased Duty Factors.

PURPOSE: Running with increased duty factors (DF) has been shown to effectively reduce external forces during running. In this study, we investigated whether running with increased DF (INCR) also reduces internal musculoskeletal loading measures, defined as peak muscle forces, muscle force impulses, and peak joint contact forces compared with a runners' preferred running pattern (PREF). METHOD: Ten subjects were instructed to run with increased DF at 2.1 m·s -1 . Ground reaction forces and three-dimensional kinematics were simultaneously measured. A musculoskeletal model was used to estimate muscle forces based on a dynamic optimization approach, which in turn were used to calculate muscle force impulses and (resultant and three-dimensional) joint contact forces of the ankle, knee, and hip joint during stance. RESULTS: Runners successfully increased their DF from 40.6% to 49.2% on average. This reduced peak muscle forces of muscles that contribute to support during running, i.e., the ankle plantar flexors (-19%), knee extensors (-18%), and hip extensors (-15%). As a consequence, peak joint contact forces of the ankle, knee, and hip joint reduced in the INCR condition. However, several hip flexors generated higher peak muscle forces near the end of stance. CONCLUSIONS: Running with increased DF lowers internal loading measures related to support during stance. Although some swing-related muscles generated higher forces near the end of stance, running with increased DF can be considered as a preventive strategy to reduce the occurrence of running-related injuries, especially in running populations that are prone to overuse injuries.

Inter-limb Asymmetry of Equilibrium Regulation in the Legs of 10-11-Year-Old Boys during Overground Sprinting.

Short-distance running at top speed is important in field sports. Previous studies have analyzed kinematic and kinetic properties of sprinting in adults, but equivalent knowledge in children is underexplored. Quantifying relevant aspects of children's sprinting is useful for classifying their running skills and providing effective coaching based on motor control theory. This study aimed to clarify differences in equilibrium regulation in more- and less-skilled boy sprinters. Five 10-11-year-old boys regularly participating in lessons at the Mizuno running school performed 30-meter and 50-meter field track sprints, and the kinematic and electromyography findings were recorded. Equilibrium-point-based synergy analysis was then applied to estimate their respective virtual trajectories. The virtual trajectory is an equilibrium time sequence that indicates how the central nervous system controls a skeletal system with multiple muscles. The results suggested that: (1) the equilibrium of the right and left legs was regulated differently, although together the legs showed similar kinematics; (2) in the first type of virtual trajectory (type-I) in one leg, the equilibria after foot-strike were regulated intermittently during the early swing phase; (3) in the second type of virtual trajectory (type-II) in the other leg, the equilibria after foot-strike were continuously regulated during the early swing phase; and (4) the less-skilled child runners showed a slow equilibrium action response in both types of virtual trajectory during the early swing phase. These findings provide insights for "tailor-made" coaching based on the type of leg control during sprinting.Clinical relevance-Information on gait asymmetry would be beneficial not only for coaching to improve sprint training but also from clinical and injury perspectives.

Gold Nanoparticles Produced by Low-temperature Heating of the Dry Residue of a Droplet of an HCl Acidic Solution of HAuCl4·4H2O in a Low Vacuum.

An easy method is presented for producing gold nanoparticles. We show that by performing simultaneous low-temperature heating of a quartz glass substrate on which the dry residue of a 10 µL droplet of an HCl acidic solution of HAuCl4·4H2O is deposited and a counter substrate using Peltier devices in a low vacuum produced by a rotary pump, gold nanoparticles with sizes ranging from about twenty to one hundred and several tens of nanometers are produced on the counter substrate. In this study, an application of a gold nanoparticle substrate produced by this method to the sample holder for surface-enhanced Raman scattering analysis is also shown.

Relationship between duty factor and external forces in slow recreational runners.

OBJECTIVES: Recreational runners show a large interindividual variation in spatiotemporal characteristics. This research focused on slow runners and intended: (1) to document the variance in duty factor (DF) between runners in a real-life running setting and (2) examine whether the interindividual variation in DF and stride frequency (SF) relates to differences in external loading parameters between runners. METHODS: Spatiotemporal characteristics of 23 slow runners (ie, <2.6 m/s) were determined during a 5.2 km running event. To relate the interindividual variation in DF and SF to differences in external forces between runners (maximal vertical ground reaction force (FzMax), peak braking force (PBF) and vertical instantaneous loading rate (VILR)), 14 of them were invited to the lab. They ran at 1.9 m/s on a treadmill while ground reaction forces were recorded. A multiple linear regression analysis was conducted to investigate the effect of DF and SF on external force measures. RESULTS: DF between slow runners varied from 42.50% to 56.49% in a recreational running event. DF was found to be a significant predictor of FzMax (R²=0.755) and PBF (R²=0.430). SF only improved the model for PBF, but to a smaller extent than DF (R² change=0.191). For VILR, neither DF nor SF were significant predictors. CONCLUSION: External forces are lower in recreational runners that run with higher DFs and slightly lower SFs. These findings may be important for injury prevention purposes, especially directed to recreational runners that are more prone to overuse injuries.

Grounded Running Reduces Musculoskeletal Loading.

PURPOSE: Recent observations demonstrate that a sizeable proportion of the recreational running population runs at rather slow speeds and does not always show a clear flight phase. This study determined the key biomechanical and physiological characteristics of this running pattern, i.e., grounded running (GR), and compared these characteristics with slow aerial running (SAR) and reference data on walking at the same slow running speed. METHODS: Thirty male subjects performed instructed GR and SAR at 2.10 m·s on a treadmill. Ground reaction forces, tibial accelerations, and metabolic rate were measured to estimate general musculoskeletal loading (external power and maximal vertical ground reaction force), impact intensity (vertical instantaneous loading rate and tibial acceleration), and energy expenditure. More explicit measures of muscular loading (muscle stresses and peak eccentric power) were calculated based on a representative subsample, in which detailed kinematics and kinetics were recorded. We hypothesized that all measures would be lower for the GR condition. RESULTS: Subjects successfully altered their running pattern upon a simple instruction toward a GR pattern by increasing their duty factor from 41.5% to 51.2%. As hypothesized, impact intensity, general measures for musculoskeletal, and the more explicit measures for muscular loading decreased by up to 35.0%, 20.3%, and 34.0%, respectively, compared with SAR. Contrary to our hypothesis, metabolic rate showed an increase of 4.8%. CONCLUSIONS: Changing running style from SAR to GR reduces musculoskeletal loading without lowering the metabolic energy requirements. As such, GR might be beneficial for most runners as it has the potential to reduce the risk of running-related injuries while remaining a moderate to vigorous form of physical activity, contributing to fulfillment of the recommendations concerning physical activity and public health.

A case of Mikulicz's disease complicated by malignant lymphoma: a postmortem histopathological finding.

A 66-year-old Japanese man with an 11-year history of Mikulicz's disease (MD) received continuous corticosteroid administration. At age 58, a left renal pelvic mass was identified and diagnosed as an IgG4-related inflammatory pseudotumor. The patient underwent an operation to remove the tumor. Subsequently, he contracted repeated pulmonary infections and eventually died of severe gastrointestinal bleeding. Autopsy revealed systemic lymph node swelling and infiltration in some organs, and diffuse large B-cell lymphoma (DLBCL) was diagnosed. These findings suggest that an IgG4-related disease can be causally related to the development of malignant lymphoma through the occurrence of mucosa-associated lymphoid tissue lymphoma.

Primary gastric diffuse large B-cell lymphoma with orbital involvement: diagnostic usefulness of 18F-fluorodeoxyglucose positron emission tomography.

A 38-year-old man presented to our hospital with abdominal pain and melena. Gastrointestinal endoscopy revealed a large gastric ulcer, and the pathological diagnosis of diffuse large B-cell lymphoma (DLBCL) was made based on immunohistochemical findings. Left diplopia developed soon after commencement of chemotherapy. Despite normal findings from head MRI, orbital involvement in DLBCL was detected with 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). The patient was treated with salvage chemotherapy with success. Treatment analysis using FDG-PET for patients with DLBCL, especially for those with clinical symptoms and negative findings on conventional modalities, may be useful for assessing disease status and adjusting treatments.

Usefulness of double balloon enteroscopy and video capsule endoscopy for the diagnosis and management of primary follicular lymphoma of the gastrointestinal tract in its early stages.

AIM: The aim of this study is to evaluate the usefulness of double balloon enteroscopy (DBE) and video capsule endoscopy (VCE) in patients with primary follicular lymphoma (FL) of the gastrointestinal (GI) tract. Furthermore, we estimate the effectiveness of chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone) including rituximab for them. METHODS: Thirteen consecutive patients who were diagnosed of having FL in the duodenum between July 2005 and September 2008 were studied. All patients were given the conventional staging examinations, including total enteroscopy using DBE and/or VCE procedures. Chemotherapy was performed after written informed consent. Response assessment was performed every 6-12 months. The median follow-up period was 30.2 months. RESULTS: FL was diagnosed in each patient as low grade (grade 1, n = 7; 2, n = 6) and, in all but 4 patients, localized lymphoma (stage I, n = 8; II(1), n = 1; II(2), n = 4). DBE revealed multifocal lesions in the jejunum in 10 of the patients, and in the ileum in 6. VCE showed similar findings in the jejunum in the recent 2 patients. Eleven of 13 patients finally received chemotherapy, and all of them achieved complete regression. They showed no evidence of recurrence after that. CONCLUSION: Total examination of the small intestine using DBE should be performed before treatment to choose a suitable treatment procedure for primary FL of the GI tract. On the other hand, VCE is useful for screening and following the small intestine in the patients with it. Chemotherapy is effective to achieve complete regression of primary FL of the GI tract.

Altered expression of CDX-2, PDX-1 and mucin core proteins in "Ulcer-associated cell lineage (UACL)" in Crohn's disease.

The ulcer-associated cell lineage (UACL) induced at the site of ileac chronic ulceration in Crohn's disease has been reported to show histological differentiation resembling gastric pyloric mucosa. To clarify the significance of homeobox gene-encoded transcription factors in the formation of the UACL in Crohn's disease, we investigated the immunohistochemical expression of gastrointestinal mucins (MUC5AC for gastric surface mucous cells; MUC6 for gastric gland mucous cells, and MUC2 for intestinal goblet cells) and homeobox gene-encoded transcription factors (CDX-2 for intestinal mucosa and PDX-1 for pyloric mucosa) in the UACL. The analysis was undertaken on ileal mucosa obtained from ileal resections performed in 19 patients with active Crohn's disease of the small bowel. The UACL was observed in nine patients. In the UACL, expression of mucous cells with a foveolar-structure showed immunoreactivity to MUC5AC, and the mucous cells with a glandular structure showed immunoreactivity to MUC6, and the expression of MUC2 was decreased. In addition, we detected the decreased expression of CDX-2 along with the increased expression of PDX-1 in the UACL. The UACL showed histological differentiation simulating gastric pylori mucosa. The down-regulation of CDX-2 and the up-regulation of PDX-1 could be an important mechanism in the induction of the UACL.

Ultrastructure of Helicobacter pylori in human gastric mucosa and H. pylori-infected human gastric mucosa using transmission electron microscopy and the high-pressure freezing-freeze substitution technique.

BACKGROUND: Conventional ultrastructural analyses of Helicobacter pylori and H. pylori-infected gastric mucosa by transmission electron microscopy (TEM) have limitations because of structural artifacts introduced during fixation. METHODS: We used high-pressure freezing (HPF) followed by freeze substitution for TEM to investigate the ultrastructure of H. pylori and H. pylori-infected gastric mucosa. For HPF-freeze substitution, human gastric biopsy specimens were placed in the HPF instrument at a pressure of approximately 2,000 atm at the temperature of liquid nitrogen. Specimens were then transferred to an instrument for freeze substitution. Specimens were first placed in acetone containing 2% OsO4 at -85 degrees C. The temperature was increased to -3 degrees C, followed by embedding in Quetol 812. Ultrathin sections were double-stained by uranium acetate/lead nitrate. HPF and conventionally prepared samples were examined by TEM. RESULTS: The H. pylori envelope was clearly seen to consist of an outer membrane, periplasmic space, and plasma membrane. The periplasmic space was filled with electron-dense materials. A peptidoglycan layer was only occasionally visible. A thick, very fine filamentous or reticular fringe corresponding to the bacterial glycocalyx was seen surrounding the H. pylori cells. At the adhesion loci of H. pylori to gastric epithelial cells, H. pylori was connected to the epithelial cells by very fine, thickly arranged filaments or more closely, with a contact zone. The epithelial cells showed indentations or pedestals. CONCLUSIONS: The well-developed, thick bacterial glycocalyx of H. pylori appears to strongly interact with external cellular components and may play an important role in the adhesion of H. pylori to epithelial cells.

Regulation of the ASC expression in response to LPS stimulation is related to IL-8 secretion in the human intestinal mucosa.

Expression of the caspase-activating adaptor ASC was reported to be associated with the production of IL-8, a primary mediator of mucosal inflammation, in vitro. However, the significance of the ASC-mediated IL-8 production in primary tissues has remained poorly understood. Primary intestinal mucosa isolated from surgically resected ileum or colon was incubated with several concentrations of LPS or left untreated. ASC expression was up-regulated at 2 h after stimulation with low doses of LPS (1-10 ng/ml), and was associated with IL-8 secretion, and then was down-regulated later. In contrast, ASC expression remained at the basal level in mucosal tissue treated with a high dose of LPS (1000 ng/ml). Interestingly, in mucosa from several cases of Crohn's disease, ASC was highly expressed without stimulation, and IL-8 was stably secreted with no regulation by LPS. These findings revealed that ASC expression correlates with IL-8 secretion and may play an important role in maintaining mucosal homeostasis.

Helicobacter pylori infection increases cell kinetics in human gastric epithelial cells without adhering to proliferating cells.

We investigated the effect of H. pylori infection on cell proliferation of gastric mucosa using immunostaining for H. pylori or Ki67. H. pylori cells attached to surface mucous cells covering luminal surface and the upper part of gastric foveolae, and up-regulated the proliferative activity of gastric epithelial cells without adhering to the proliferating epithelial cells.