Purpose: Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice. Materials and Methods: The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture. Results: From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production. Conclusions p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.

Purpose: There is few evidence regarding the optimal salvage treatment options for loco-reginal recurrence of esophageal cancer. This study aimed to evaluate the clinical outcomes of salvage radiotherapy (RT) in patients with loco-regional recurrence (LRR) after surgery for esophageal cancer. Materials and Methods: We retrospectively reviewed 147 esophageal cancer patients who received salvage RT for loco-regional recurrence between 1996 and December 2019. A total dose of 60 Gy in 20 fractions was used for RT alone and 60-70 Gy in 30-35 fractions for concurrent chemoradiotherapy (CCRT). Results: The patients’ median age was 65 years (range, 41 to 86 years). The median disease-free interval was 13.5 months (1.0 to 97.4 months). After a median 18.8 months follow-up, the 2-year overall survival (OS) and progression-free survival (PFS) rates were 38.1% and 25.9%, respectively. The median OS and PFS were 18.8 and 8.4 months, respectively. The CCRT could not improve OS compared to RT (p=0.336), but there was a trend of better PFS in the CCRT group. Regarding toxicities, the rate of grade 3 or higher toxicity was 10.9% occurring in 16 patients, and it was higher in patients who received CCRT than in the RT alone group (19.6% vs. 6.3%, p=0.023). Conclusion Salvage RT alone as well as CCRT could be effective in patients with locoregionally recurrent esophageal cancer.

Purpose: Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice. Materials and Methods: The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture. Results: From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production. Conclusions p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.

Purpose: Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice. Materials and Methods: The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture. Results: From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production. Conclusions p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.

Purpose: There is few evidence regarding the optimal salvage treatment options for loco-reginal recurrence of esophageal cancer. This study aimed to evaluate the clinical outcomes of salvage radiotherapy (RT) in patients with loco-regional recurrence (LRR) after surgery for esophageal cancer. Materials and Methods: We retrospectively reviewed 147 esophageal cancer patients who received salvage RT for loco-regional recurrence between 1996 and December 2019. A total dose of 60 Gy in 20 fractions was used for RT alone and 60-70 Gy in 30-35 fractions for concurrent chemoradiotherapy (CCRT). Results: The patients’ median age was 65 years (range, 41 to 86 years). The median disease-free interval was 13.5 months (1.0 to 97.4 months). After a median 18.8 months follow-up, the 2-year overall survival (OS) and progression-free survival (PFS) rates were 38.1% and 25.9%, respectively. The median OS and PFS were 18.8 and 8.4 months, respectively. The CCRT could not improve OS compared to RT (p=0.336), but there was a trend of better PFS in the CCRT group. Regarding toxicities, the rate of grade 3 or higher toxicity was 10.9% occurring in 16 patients, and it was higher in patients who received CCRT than in the RT alone group (19.6% vs. 6.3%, p=0.023). Conclusion Salvage RT alone as well as CCRT could be effective in patients with locoregionally recurrent esophageal cancer.

Purpose: Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice. Materials and Methods: The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture. Results: From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production. Conclusions p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.

Purpose: There is few evidence regarding the optimal salvage treatment options for loco-reginal recurrence of esophageal cancer. This study aimed to evaluate the clinical outcomes of salvage radiotherapy (RT) in patients with loco-regional recurrence (LRR) after surgery for esophageal cancer. Materials and Methods: We retrospectively reviewed 147 esophageal cancer patients who received salvage RT for loco-regional recurrence between 1996 and December 2019. A total dose of 60 Gy in 20 fractions was used for RT alone and 60-70 Gy in 30-35 fractions for concurrent chemoradiotherapy (CCRT). Results: The patients’ median age was 65 years (range, 41 to 86 years). The median disease-free interval was 13.5 months (1.0 to 97.4 months). After a median 18.8 months follow-up, the 2-year overall survival (OS) and progression-free survival (PFS) rates were 38.1% and 25.9%, respectively. The median OS and PFS were 18.8 and 8.4 months, respectively. The CCRT could not improve OS compared to RT (p=0.336), but there was a trend of better PFS in the CCRT group. Regarding toxicities, the rate of grade 3 or higher toxicity was 10.9% occurring in 16 patients, and it was higher in patients who received CCRT than in the RT alone group (19.6% vs. 6.3%, p=0.023). Conclusion Salvage RT alone as well as CCRT could be effective in patients with locoregionally recurrent esophageal cancer.

Purpose: Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice. Materials and Methods: The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture. Results: From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production. Conclusions p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.

Introduction: Time away from training and competition from sport injuries may lead to detrimental effects on muscle strength and endurance. The cross-education effect plays an important role in preserving strength during recovery and rehabilitation; however, the effects have been found to be inconclusive. In addition, the distinct impacts of eccentric and concentric strengthening exercises need to be explored. The objective of this study was to compare the cross-education effects of eccentric and concentric wrist flexor strengthening exercises on hand grip strength among recreational athletes. Methods: A total of 39 recreational athletes aged between 18-25 years old were randomly assigned into two groups of wrist flexor strengthening exercise: eccentric (ECC) and concentric (CON) training groups. The training period for the study was 4 weeks with 3 sessions of strengthening exercises per week. Handgrip strength was measured bilaterally, before and after the intervention using the JAMAR handgrip dynamometer. Results: Significant increases in hand grip strength were observed for the ECC and CON groups in both the trained and untrained hands following 4 weeks of training. However, the handgrip strength between the two groups in the untrained hand was not significantly different (p=0.64). The strength gain in the untrained hand was 9.8% and 10.8%, for ECC and CON groups, respectively. Conclusion: The cross-education effect was significant in improving strength in the untrained hand. There was no difference in strength gains between concentric and eccentric strength training.

Background/Aims: The effect of proton pump inhibitors (PPIs) on the lower gastrointestinal (GI) tract is uncertain, with potential to worsen damage. This study aimed to find the best method for protecting the entire GI tract from mucosal damage. Methods: A retrospective cohort study at Samsung Medical Center (2002-2019) included 195,817 patients prescribed GI mucosa-damaging agents. The primary goal was to assess the effectiveness of GI protective agents in preventing significant hemoglobin drops (>2 g/dL), indicating overall GI mucosal damage. Self-controlled case series and landmark analysis were used to address biases in real-world data. Results: The incidence rate ratios for rebamipide, PPI, and histamine-2 receptor antagonist (H2RA) were 0.34, 0.33, and 0.52, respectively. Rebamipide showed a significantly lower incidence rate than H2RA and was comparable to PPIs. Landmark analysis revealed significant reductions in hemoglobin drop risk with rebamipide and H2RA, but not with PPI. Conclusions Rebamipide, like PPIs, was highly effective in preventing blood hemoglobin level decreases, as shown in real-world data. Rebamipide could be a comprehensive strategy for protecting the entire GI tract, especially when considering PPIs' potential side effects on the lower GI tract.