Force-Velocity Profiling During the Braking Phase of Countermovement Jump: Relationship to Eccentric Strength and Validity of the 2-Point Method.

ABSTRACT: Nishiumi, D, Yamaguchi, S, Kurokawa, T, Wakamiya, K, and Hirose, N. Force-velocity profiling during the braking phase of countermovement jump: Relationship to eccentric strength and validity of the 2-point method. J Strength Cond Res 37(11): 2141-2148, 2023-The aims of this study were threefold: to investigate the force-velocity profile during the braking phase (bFVP) of the countermovement jump (CMJ) and its relationship with other performance indicators, and whether it could be measured using the two-point method. Sixteen trained men performed 6 different loaded CMJs (0%, 32 kg, 60, 80, 100, and 120% body mass), and eccentric strength measurements were determined. Scatter plots were created using the mean force and velocity during the braking phase of each loaded CMJ. The corrected Akaike's information criterion (AICc) was calculated by fitting linear, quadratic, and cubic regression equations to the bFVP and compared using the 1-way analysis of variance and Bonferroni's post hoc tests. A correlation analysis was performed between the bFVP and other performance indicators. A bias assessment was performed to validate the 2-point method of the bFVP. The significance level was set at p < 0.05. The AICc in the linear regression equation was significantly lower (p < 0.05) than those in the other regression equations. Significant correlations were found between the slope and theoretical maximum force of the bFVP obtained from the linear regression equation and eccentric 1 repetition maximum. The acceptable condition for bias was met by 0-120%. The bFVP is likely to have a linear relationship and can be associated with eccentric strength. Furthermore, the 2-point method in bFVP has validity.

Associations of eccentric force variables during jumping and eccentric lower-limb strength with vertical jump performance: A systematic review.

The purpose of this systematic review was to summarize the associations of eccentric force variables during jumping and eccentric lower-limb strength with vertical jump performance. A literature search was conducted in September 2022 using PubMed, Web of Science, and Scopus. Thirteen cross-sectional studies investigating the relationship between eccentric force and strength variables, such as force, rate of force development (RFD), power, time, and velocity, and vertical jump performance, including the jump height, reactive strength index (RSI), and reactive strength index-modified (RSImod), were included in this systematic review. As eccentric strength, variables during the unloading-to-braking phase of countermovement jump (CMJ) (force, RFD, etc.) and the eccentric force of the squat movement and knee joint were included. The CMJ height, RSImod, and drop jump RSI were included to analyze the vertical jump performance. The modified form of the Downs and Black checklist was used to evaluate quality. Associations between the force and RFD during the descending phase of the CMJ and jump height were observed in some studies but not in others, with differences between the studies. Some studies reported associations between the force and/or RFD during the descending phase of the CMJ and RSImod of the CMJ, with no differences among their results. In addition, there are associations of the eccentric forces during squatting and knee extension with the CMJ and the drop jump heights and RSI of the drop jump. The eccentric force variables in the CMJ and RSImod are related; however, their relationship with jump height remains unclear. Furthermore, improved eccentric muscle strength may contribute to vertical jump height because of the associations of the eccentric strength during knee extension and squatting with jump height.

Adenocarcinoma in the jejunal pouch after proximal gastrectomy for early stage upper gastric cancer: report of a case.

An 84-year-old male was admitted to a local clinic suffering from general fatigue with associated anemia, and therefore was referred to our hospital. His medical history included a proximal gastrectomy with the formation of a jejunal pouch as a reconstructive treatment for early upper gastric cancer at 78 years of age (6 years prior). A type 2 tumor located in the jejunal pouch almost completely surrounded by small intestinal mucosa was demonstrated by gastrointestinal endoscopy. The biopsy specimens showed a moderately differentiated tubular adenocarcinoma. Computed tomography showed no lymphadenopathy or hepatic metastases. A resection of the residual stomach and jejunal pouch was performed. Based on the histological findings from the resected specimen, the tumor was considered to be primary adenocarcinoma in the jejunal pouch. The postoperative course was uneventful, and the patient has shown no evidence of any recurrence during the 6-year period after the most recent surgery.

[Thymoma which is detected with a cough derived from pulmonary invasion; report of a case].

A 83-year-old female was referred to our hospital for investigation of a persistent cough. A chest X-ray showed enlargement of the mediastinum. Computed tomography of the chest showed an anterior mediastinal mass with a maximal diameter of 6.5 cm, which had invasion to the lung. The patient underwent thymothymectomy combined resections of the lung, pericardium, and left innominate vein through a median sternotomy. Histological examination of the resected tumor revealed a World Health Organization (WHO) classification type B3 thymoma with infiltration into the lung. There were no infiltrations of the tumor into the pericardium and the innominate vein. A persistent cough disappeared after surgery. No adjuvant chemotherapy was performed. She is still free from disease with a follow-up period of 4 months. We report a rare case of thymoma detected with a persistent cough derived from pulmonary invasion.

[Lung carcinoma producing carbohydrate antigen 19-9; report of a case].

A 58-year-old female was admitted to our hospital for investigation of serum elevation of carbohydrate antigen (CA 19-9). Computed tomography of the chest revealed a spiculated pulmonary nodule with the longest diameter of 3.7 cm in the right lower lobe. The diagnosis of lung adenocarcinoma was made. The patient underwent right lower lobectomy with lymphnode dissection. Histological examination revealed acinar type adenocarcinoma. The tumor was classified as stage IB with T2aN0M0. Immunohistochemically, the tumor cells stained positively for CA19-9. The serum CA19-9 level returned to a normal level after operation, but increased again with mediastinal lymphnode metastasis and brain metastasis. She died after an operation in 16 months.

Higher-order structure of polymer melt described by persistent homology.

The optimal method of the polymer Materials Informatics (MI) has not been developed because the amorphous nature of the higher-order structure affects these properties. We have now tried to develop the polymer MI's descriptor of the higher-order structure using persistent homology as the topological method. We have experimentally studied the influence of the MD simulation cell size as the higher-order structure of the polymer on its electrical properties important for a soft material sensor or actuator device. The all-atom MD simulation of the polymer has been calculated and the obtained atomic coordinate has been analyzed by the persistent homology. The change in the higher-order structure by different cell size simulations affects the dielectric constant, although these changes are not described by a radial distribution function (RDF). On the other hand, using the 2nd order persistent diagram (PD), it was found that when the cell size is small, the island-shaped distribution become smoother as the cell size increased. There is the same tendency for the condition of change in the monomer ratio, the polymer chain length or temperature. As a result, the persistent homology may express the higher-order structure generated by the MD simulation as a descriptor of the polymer MI.

CD4+ and CD8+ T cells cooperate to improve prognosis of patients with esophageal squamous cell carcinoma.

The purpose of this study is to clarify the roles of immune cell types, both individually and synergistically, in esophageal squamous cell carcinoma (ESCC). One hundred and twenty-two patients (105 males and 17 females; mean age, 62.3 years) with primary ESCC underwent surgical tumor resection at the Department of Surgical Oncology, School of Medicine, Hokkaido University and two affiliated hospitals between 1989 and 1999. Immunohistochemical analyses were performed for CD4, CD8, and CD57 (surface markers for natural killer cells). Patient prognosis was found to correlate with the number of CD4(+) and CD8(+) T cells in the stroma and the number of CD8(+) T cells within the cancer cell nest. Furthermore, the number of CD8(+) T cells in the stroma and within the cancer cell nest was found to be correlated [correlation coefficient (r) = 0.790; P < 0.0001). However, no correlation was observed between the number of natural killer cells and patient prognosis. Patients were classified into the following four groups based on CD4(+) and CD8(+) T-cell count: CD4/8(+/+), CD4/8(+/-), CD4/8(-/+), CD4/8(-/-). For the general patient pool, as well as for selected p-stage III and IV cases (n = 48), the survival rate for CD4/8(+/+) patients was significantly higher than that for the other three groups (log-rank test, P = 0.0012 and 0.0088, respectively). Multivariate analysis identified CD4/8(+/+) status, T classification, and N classification as independent prognostic factors. In conclusion, cooperation between CD4(+) and CD8(+) T cells correlates strongly with ESCC patient prognosis.

Deficiency of hMLH1 and hMSH2 expression is a poor prognostic factor in esophageal squamous cell carcinoma.

BACKGROUND: The human Mut-L-Homologon-1 (MLH1) and Mut-S-Homologon-2 (MSH2) are post replication mismatch repair (MMR) genes. METHODS: We examined the correlation of the clinical features of 122 patients with esophageal squamous cell carcinoma (ESCC) with the expression of MLH1 and MSH2 by immunohistochemical analysis. RESULTS: According to our criteria, 34 and 25 cases did not express MLH1 and MSH2, respectively. Expression of both the MLH1 and MSH2 gene products was observed in 73 (59.8%) cases; loss of MLH1 or MSH2 expression was detected in 35(28.7%) cases. Fourteen (11.5%) cases demonstrated loss of both MLH1 and MSH2 expression in ESCC. Loss of MLH1 and/or MSH2 gene expression significantly correlated with increases in malignancy, as evidenced by increases in the existence of metastatic lymph nodes (P = 0.0056), extensive invasion (P = 0.0007), and poor differentiation (P = 0.0992). The MLH1-negative patients had a significantly poorer prognosis than those in the MLH1-positive group (P = 0.0043). Similar results were observed for MSH2 expression (P = 0.0002). Patients both MLH1 and MSH2 negative exhibited the most poor clinical outcome than other patients (P < 0.0001). CONCLUSION: We conclude that MMR protein expression, detected by immunohistochemistry, is a useful marker providing information necessary to decide appropriate therapeutic strategies in patients with ESCC.

Spontaneous pneumothorax secondary to radiographically occult lung metastasis from parapharyngeal synovial sarcoma: report of a case.

This report describes a case of secondary pneumothorax caused by a radiographically occult lung metastasis from parapharyngeal synovial sarcoma, a relatively rare tumor known to be highly metastatic to the lung. Although chest X-ray and thoracic computed tomography scan failed to detect the metastatic nodule in the right lung, the surgically resected specimen proved to be a 3-mm lung metastasis. To our knowledge, only eight cases of lung metastases from synovial sarcoma causing pneumothorax have ever been reported. In most of these cases, the lung metastases were detected by radiographical examinations. However, in this patient, the metastatic lesion was not detected during examination. It is speculated that secondary pneumothorax caused by synovial sarcoma may occur during the early stages of lung metastasis. Therefore, if pneumothorax occurs in a patient with a synovial sarcoma, the possibility of lung metastasis should be carefully considered, even if it is undetectable on radiological examinations.

CD8+ tumor-infiltrating lymphocytes together with CD4+ tumor-infiltrating lymphocytes and dendritic cells improve the prognosis of patients with pancreatic adenocarcinoma.

OBJECTIVE: Recent studies have demonstrated the importance of tumor immunity for a cancer patient's prognosis. In some types of cancer, it has been shown through immunohistochemical analysis that the existence of CD8+ tumor-infiltrating lymphocytes (TILs) is a crucial factor in determining prognosis. In an experimental model, CD4+ lymphocytes together with CD8+ lymphocytes contributed significantly to tumor immunity. METHODS: Specimens were taken from 80 surgically resected pancreatic adenocarcinomas between 1992 and 1999. Immunohistochemical staining of CD4, CD8, and S100 protein was performed, and the levels of these proteins were determined by microscopic analysis. The percentages of patients in the CD4(+) and CD8(+) groups were 59% (47/80) and 25% (16/80), respectively. When separated into 4 groups, CD4/8(+/+), CD4/8(+/-), CD4/8(-/+) and CD4/8(-/-), the overall survival rate was significantly higher in CD4/8(+/+) patients (13 cases) compared with those in all other groups combined (67 cases; P = 0.0098). CD4/8(+/+) status was negatively correlated with tumor depth and TNM stage. Multivariate analyses showed that CD4/8(+/+) status was an independent favorable prognostic factor. The number of tumor-infiltrating S100 protein positive cells was also significantly higher in the CD4/8(+/+) group than in others (P = 0.0084). CONCLUSIONS: In pancreatic adenocarcinoma, the presence of CD4+ TILs together with CD8+ TILs serves as a good indicator of the patient's outcome after surgical treatment.