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1.
Sports Biomech ; 20(4): 481-494, 2021 Jun.
Article in English | MEDLINE | ID: mdl-30693842

ABSTRACT

We aimed to evaluate the accuracy of a new method to calculate the centre of pressure (COP) on a starting block above a force platform, and to examine how this method affected lower extremity joint torques during the block clearance phase compared against a previously used method which projects the COP from the metatarsophalangeal (MP) joint. To evaluate the accuracy of the new method, one experimenter applied force at 18 known locations on a starting block (under six block position and orientation conditions), during which ground reaction force was recorded underneath using a force platform. Two sprinters then performed three block starts each, and lower extremity joint torques were calculated during block clearance using the COP obtained from the new method and from the projection of the MP joint location. The calculated COP using the new method had a mean bias of ≤0.002 m. There were some large differences (effect sizes = 0.11-4.01) in the lower extremity joint torques between the two methods which could have important implications for understanding block clearance phase kinetics. The new method for obtaining the COP on a starting block is highly accurate and affects the calculation of joint torques during the block clearance phase.


Subject(s)
Athletic Performance/physiology , Lower Extremity/physiology , Running/physiology , Sports Equipment , Weight-Bearing/physiology , Biomechanical Phenomena , Humans , Male , Pressure , Young Adult
2.
J Sports Sci ; 38(21): 2437-2445, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32608346

ABSTRACT

This study examined whether modulation of the centre of pressure (COP) on the starting block surface would improve sprint start performance. Twenty male national-level sprinters performed 15-m sprints from the starting blocks in three different conditions (normal, anterior loading and posterior loading), during which ground reaction forces (GRFs) were recorded. The COP location, 10-m time, average horizontal external power (AHEP), spatiotemporal and GRF variables were calculated. The results demonstrate that, although modulation of COP location may not improve sprint start performance for the entire group, it could improve the corresponding performance for specific individuals. A sprinter who favours the posterior front block location and more to the posterior rear block COP location on the block surface at the set position could possibly improve AHEP using the anterior loading condition. An improvement of AHEP in the anterior loading condition (p =.056, effect size [ES] =.305) would be accomplished by greater rear block anteroposterior mean force (p =.043, ES =.574). Moreover, the posterior loading condition may improve the 10-m time and/or AHEP for some individuals, whereas no specific characteristics of the individuals were found. Finally, an improvement of 10-m time in the posterior loading condition (p =.015, ES =.609) would be accomplished by shorter reaction time (p =.035, ES =.780).


Subject(s)
Athletic Performance/physiology , Foot/physiology , Running/physiology , Weight-Bearing , Acceleration , Biomechanical Phenomena , Humans , Male , Reaction Time , Sports Equipment , Young Adult
3.
Article in English | MEDLINE | ID: mdl-33344945

ABSTRACT

Force application locations [i.e., center of pressure (COP)] on the block surface are not necessarily the same for individuals even if the same block locations and angles are used. The purpose of this study was to examine the association of block clearance performance with COP location on the starting block surface. Twenty-one male sprinters performed 60 m sprints from the starting blocks, during which the ground reaction forces (GRFs) on the starting blocks were recorded using two force platforms. Using a previously validated method, changes in COP location on the block surface during the block clearance for each block was calculated from the marker coordinates on the block surface, GRF signals, and moment data around the center of the force platform at the ground level. Moreover, average horizontal external power (AHEP), which was considered the key performance criterion, was computed. Statistical parametric mapping (SPM) 1D linear regressions were used to test relationships between AHEP and COP location curves in the anteroposterior and vertical directions. The COP for both legs moved backward and upward (0.042 and 0.042 m for the front block and 0.030 and 0.034 m for the rear block) at first and then forward and downward (0.113 and 0.094 m for the front block and 0.095 and 0.087 m for the rear block) toward the toe-off. Based on SPM results, AHEP was correlated with front block anteroposterior and vertical COP locations from 12.9 to 20.8% and from 10.4 to 22.2% of the force production phase, respectively, while it was correlated with rear block vertical COP location from 31.9 to 37.4% of the force production phase. In conclusion, the current results demonstrate that, regardless of the starting block location and angle, better sprint start performance is accomplished with a higher and more to the rear COP on the starting block surface, when COP is located close to heel during the middle phase of the block clearance. The fact that the COP location is related to sprint start performance will be useful for sprinters and coaches who intend to improve sprint start performance.

4.
Ophthalmologica ; 238 Suppl 1: 21-27, 2017.
Article in English | MEDLINE | ID: mdl-28693011

ABSTRACT

Objetivo: Comparar la efectividad de ranibizumab intravítreo (RIV) para el tratamiento del edema macular diabético (EMD) en ojos con y sin vitrectomía previa. Procedimientos: Evaluamos de manera prospectiva la mejor agudeza visual corregida (MAVC) y el grosor macular central (GMC) tras el tratamiento con RIV durante 6 meses. Resultados: No se observaron diferencias significativas en la MAVC o GMC inicial en ninguno de los dos grupos. En el grupo no vitrectomizado (n = 15), los cambios medios en la MAVC y GMC hasta el sexto mes de tratamiento con respecto al valor inicial resultaron significativos (p < 0,01). En el grupo vitrectomizado (n = 10), se observó una mejora más lenta, y la mejora media en la MAVC no resultó significativa (p = 0,5), aunque la media en la disminución del GMC sí que lo fue (p < 0,05). No se observaron diferencias significativas en los cambios medios en la MAVC y el GMC entre ambos grupos a los 6 meses del tratamiento. Conclusiones: La diferencia en la efectividad de RIV entre ambos grupos no resultó significativa. Ranibizumab intravítreo puede ser una opción de tratamiento incluso en pacientes vitrectomizados con EMD.

5.
Ophthalmologica ; 236(2): 67-73, 2016.
Article in English | MEDLINE | ID: mdl-27362944

ABSTRACT

PURPOSE: To compare the effectiveness of intravitreal ranibizumab (IVR) for diabetic macular edema (DME) between eyes with and without previous vitrectomy. PROCEDURES: We prospectively assessed the best-corrected visual acuity (BCVA) and central macular thickness (CMT) after IVR for 6 months. RESULTS: There were no significant differences in the baseline BCVA and CMT between both groups. In the nonvitrectomized group (n = 15), the mean changes of BCVA and CMT from baseline to month 6 were significant (p < 0.01). In the vitrectomized group (n = 10), the improvement appeared to be slower, and the mean BCVA improvement was not significant (p = 0.5), although the mean CMT decrease was significant (p < 0.05). There were no significant differences in the mean changes of BCVA and CMT between both groups at 6 months. CONCLUSIONS: The difference in the effectiveness of IVR between both groups was not significant. IVR can be a treatment option even for vitrectomized DME eyes.


Subject(s)
Diabetic Retinopathy/drug therapy , Macular Edema/drug therapy , Ranibizumab/administration & dosage , Vitrectomy , Aged , Aged, 80 and over , Diabetic Retinopathy/physiopathology , Diabetic Retinopathy/surgery , Follow-Up Studies , Glucocorticoids/administration & dosage , Humans , Intravitreal Injections , Macular Edema/physiopathology , Macular Edema/surgery , Male , Middle Aged , Prospective Studies , Time Factors , Visual Acuity
6.
Gan To Kagaku Ryoho ; 42(11): 1427-30, 2015 Nov.
Article in Japanese | MEDLINE | ID: mdl-26602405

ABSTRACT

A 71-year-old man with predialysis terminal renal insufficiency experienced peritoneal dissemination 1.5 years after low anterior resection for advanced rectal cancer. He received FOLFIRI therapy (70% dose); he achieved partial response (PR) under computed tomography and stable disease (SD) was maintained over a long term. Although Grade 3 myelosuppression was occasionally noted, he was treated with FOLFIRI for 2 years without other severe complications and without requiring the initiation of hemodialysis. After the initiation of hemodialysis, FOLFIRI treatment was continued for 1 year until progressive disease (PD). He received mFOLFOX6 as second-line therapy for 6 months, followed by LV-5-FU and a molecular targeting agent. These treatments prolonged his survival for 1 year and 8 months. FOLFIRI can be administered as an effective first-line therapy even for patients with predialysis terminal renal impairment without major renal damage. FOLFOX and molecular targeting agents should be made available and prolonged survival can be expected for advanced colorectal cancer patients with terminal renal disease after the initiation of hemodialysis.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Camptothecin/analogs & derivatives , Rectal Neoplasms/drug therapy , Renal Insufficiency, Chronic/therapy , Aged , Camptothecin/therapeutic use , Dialysis , Fatal Outcome , Fluorouracil/therapeutic use , Humans , Leucovorin/therapeutic use , Male , Organoplatinum Compounds/therapeutic use , Rectal Neoplasms/complications , Rectal Neoplasms/pathology , Rectal Neoplasms/surgery , Recurrence , Renal Insufficiency, Chronic/complications , Time Factors
7.
BMC Ophthalmol ; 14: 55, 2014 Apr 26.
Article in English | MEDLINE | ID: mdl-24766841

ABSTRACT

BACKGROUND: Several retinal ischemic diseases can cause neovascular glaucoma (NVG). Trabeculectomy with mitomycin C (MMC) is a relatively better treatment modality in the management of eyes with NVG than other glaucoma surgeries. The aim of this study was to investigate the factors that may influence the outcome of trabeculectomy with MMC for NVG. METHODS: Forty-nine NVG eyes from 43 patients (26 males and 17 females) underwent primary trabeculectomy with MMC. The mean follow-up period was 16.8 ± 8.1 months (range, 6 to 34 months). Twenty-one eyes of 21 patients received intravitreal bevacizumab (IVB) 3.6 ± 1.8 days before trabeculectomy with MMC. A Kaplan-Meier survival-curve analysis was used to summarize the cumulative probability of success. We examined the relationship between the surgical outcome and the following surgical factors: gender, age, history of panretinal photocoagulation, history of cataract surgery, history of vitrectomy, preoperative IVB, NVG in the fellow eye, and postoperative complications (hyphema, choroidal detachment, and formation of fibrin) by multivariate analysis. RESULTS: The survival rate was 83.7% after 6 months, 70.9% after 12 months, and 60.8% after 24 months. The Kaplan-Meier survival curves showed no significant difference in the survival rate between the eyes with preoperative IVB (n = 21) and the eyes without preoperative IVB (n = 28) (p = 0.14). The multiple logistic regression analysis showed that postoperative hyphema (odds ratio, 6.54; 95% confidence interval, 1.41 to 35.97) was significantly associated with the surgical outcome (p = 0.02). CONCLUSIONS: Postoperative hyphema was significantly correlated with the outcome of trabeculectomy for NVG. There was no significant association between preoperative IVB and postoperative hyphema or the results of trabeculectomy.


Subject(s)
Glaucoma, Neovascular/surgery , Hyphema/etiology , Postoperative Hemorrhage/etiology , Trabeculectomy/adverse effects , Adult , Aged , Angiogenesis Inhibitors/administration & dosage , Antibodies, Monoclonal, Humanized/administration & dosage , Bevacizumab , Female , Follow-Up Studies , Glaucoma, Neovascular/diagnosis , Glaucoma, Neovascular/physiopathology , Humans , Hyphema/diagnosis , Hyphema/epidemiology , Incidence , Intraocular Pressure , Intravitreal Injections , Japan/epidemiology , Male , Middle Aged , Postoperative Hemorrhage/epidemiology , Postoperative Hemorrhage/prevention & control , Retrospective Studies , Risk Factors , Survival Rate/trends , Time Factors , Treatment Outcome , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Visual Acuity
8.
Gan To Kagaku Ryoho ; 40(6): 815-7, 2013 Jun.
Article in Japanese | MEDLINE | ID: mdl-23863666

ABSTRACT

We report a case of advanced rectal cancer treated with chemotherapy, for which laparoscopic splenectomy had been effective for thrombocytopenia. A 56-year-old man suffered from advanced rectal cancer with multiple lung metastases. He underwent Hartmann's procedure and received chemotherapy with FOLFOX and FOLFIRI with bevacizumab. After 3 years and 2 months, he also suffered from splenomegaly and thrombocytopenia. Laparoscopic splenectomy produced and increased the thrombocyte count, allowing for a restart of chemotherapy. Oxaliplatin-based chemotherapy might produce hepatic sinusoid injury and induce splenomegaly owing to portal hypertension. Laparoscopic splenectomy seemed to be useful for treating thrombocytopenia, and allowed the continuation of chemotherapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/adverse effects , Organoplatinum Compounds/adverse effects , Rectal Neoplasms/drug therapy , Splenectomy , Splenomegaly/chemically induced , Thrombocytopenia/chemically induced , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Fatal Outcome , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Humans , Laparoscopy , Leucovorin/administration & dosage , Leucovorin/adverse effects , Lung Neoplasms/drug therapy , Lung Neoplasms/secondary , Male , Middle Aged , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Rectal Neoplasms/pathology , Splenomegaly/surgery
9.
World J Gastroenterol ; 15(46): 5805-12, 2009 Dec 14.
Article in English | MEDLINE | ID: mdl-19998501

ABSTRACT

AIM: To evaluate the utility of diffusion-weighted imaging (DWI) in screening and differential diagnosis of benign and malignant focal hepatic lesions. METHODS: Magnetic resonance imaging (MRI) examinations were performed using the Signa Excite Xl Twin Speed 1.5T system (GE Healthcare, Milwaukee, WI, USA). Seventy patients who had undergone MRI of the liver [29 hepatocellular carcinomas (HCC), four cholangiocarcinomas, 34 metastatic liver cancers, 10 hemangiomas, and eight cysts] between April 2004 and August 2008 were retrospectively evaluated. Visualization of lesions, relative contrast ratio (RCR), and apparent diffusion coefficient (ADC) were compared between benign and malignant lesions on DWI. Superparamagnetic iron oxide (SPIO) was administered to 59 patients, and RCR was compared pre- and post-administration. RESULTS: DWI showed higher contrast between malignant lesions (especially in multiple small metastatic cancers) and surrounding liver parenchyma than did contrast-enhanced computed tomography. ADCs (mean +/- SD x 10(-3) mm(2)/s) were significantly lower (P < 0.05) in malignant lesions (HCC: 1.31 +/- 0.28 and liver metastasis: 1.11 +/- 0.22) and were significantly higher in benign lesions (hemangioma: 1.84 +/- 0.37 and cyst: 2.61 +/- 0.45) than in the surrounding hepatic tissues. RCR between malignant lesions and surrounding hepatic tissues significantly improved after SPIO administration, but RCRs in benign lesions were not improved. CONCLUSION: DWI is a simple and sensitive method for screening focal hepatic lesions and is useful for differential diagnosis.


Subject(s)
Carcinoma, Hepatocellular , Diffusion Magnetic Resonance Imaging/methods , Liver Neoplasms , Adult , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/pathology , Diagnosis, Differential , Female , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/pathology , Male , Middle Aged , Retrospective Studies
10.
J Biosci Bioeng ; 106(5): 503-6, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19111648

ABSTRACT

When the oxidative refolding of lysozyme (Lyzm) was carried out in the presence of protein disulfide isomerase (PDI) an increased refolding rate and a recovered activity exceeding 100% were reproducibly observed. The origin of this excess activity was investigated by HPLC, SDS-PAGE, and mass spectrometry and assessed using an assay for Lyzm activity. The refolding of Lyzm was achieved through the formation of PDI-Lyzm intermediates and the excess activity was derived from the nascent lysozyme released from these complexes. The released lysozyme exhibited a higher molecular activity than observed for the native protein.


Subject(s)
Biotechnology/methods , Molecular Chaperones/metabolism , Muramidase/chemistry , Chromatography, High Pressure Liquid , Dimerization , Disulfides/chemistry , Mass Spectrometry/methods , Micrococcus/metabolism , Models, Chemical , Oxygen/chemistry , Protein Denaturation , Protein Disulfide-Isomerases , Protein Folding
11.
J Biosci Bioeng ; 106(4): 345-9, 2008 Oct.
Article in English | MEDLINE | ID: mdl-19000609

ABSTRACT

Refolding of bovine pancreatic trypsin was carried out. When starting with denatured S-S intact trypsin, the recovered activity attained was 95-100%. In contrast, the recovered activity after refolding denatured S-S reduced trypsin was considerably low compared with other proteases that have been worked with previously. Such low recovered activity was attributed to the small amount of fully reduced trypsin used as starting material for complete refolding. Taking this into account, a recovered activity of 86% could be achieved when using inhibitor-immobilized gels.


Subject(s)
Pancreas/metabolism , Trypsin/chemistry , Animals , Cattle , Chromatography, High Pressure Liquid , Ethanolamines/chemistry , Hydrogen-Ion Concentration , Mass Spectrometry/methods , Protein Conformation , Protein Denaturation , Protein Folding , Sulfhydryl Compounds , Trypsin Inhibitors/chemistry , Trypsinogen/chemistry
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