In contrast to ventricular myocytes, the structural and functional importance of atrial transverse tubules (T-tubules) is not fully understood. Therefore, we investigated the ultrastructure of T-tubules of living rat atrial myocytes in comparison with ventricular myocytes. Nanoscale cell surface imaging by scanning ion conductance microscopy (SICM) was accompanied by confocal imaging of intracellular T-tubule network, and the effect of removal of T-tubules on atrial excitation-contraction coupling (EC-coupling) was observed. By SICM imaging, we classified atrial cell surface into 4 subtypes. About 38% of atrial myocytes had smooth cell surface with no clear T-tubule openings and intracellular T-tubules (smooth-type). In 33% of cells, we found a novel membrane nanostructure running in the direction of cell length and named it 'longitudinal fissures' (LFs-type). Interestingly, T-tubule openings were often found inside the LFs. About 17% of atrial cells resembled ventricular myocytes, but they had smaller T-tubule openings and a lower Z-groove ratio than the ventricle (ventricular-type). The remaining 12% of cells showed a mixed structure of each subtype (mixed-type). The LFs-, ventricular-, and mixed-type had an appreciable amount of reticular form of intracellular T-tubules. Formamide-induced detubulation effectively removed atrial T-tubules, which was confirmed by both confocal images and decreased cell capacitance. However, the LFs remained intact after detubulation. Detubulation reduced action potential duration and L-type Ca2+ channel (LTCC) density, and prolonged relaxation time of the myocytes. Taken together, we observed heterogeneity of rat atrial T-tubules and membranous ultrastructure, and the alteration of atrial EC-coupling by disruption of T-tubules.

In contrast to ventricular myocytes, the structural and functional importance of atrial transverse tubules (T-tubules) is not fully understood. Therefore, we investigated the ultrastructure of T-tubules of living rat atrial myocytes in comparison with ventricular myocytes. Nanoscale cell surface imaging by scanning ion conductance microscopy (SICM) was accompanied by confocal imaging of intracellular T-tubule network, and the effect of removal of T-tubules on atrial excitation-contraction coupling (EC-coupling) was observed. By SICM imaging, we classified atrial cell surface into 4 subtypes. About 38% of atrial myocytes had smooth cell surface with no clear T-tubule openings and intracellular T-tubules (smooth-type). In 33% of cells, we found a novel membrane nanostructure running in the direction of cell length and named it 'longitudinal fissures' (LFs-type). Interestingly, T-tubule openings were often found inside the LFs. About 17% of atrial cells resembled ventricular myocytes, but they had smaller T-tubule openings and a lower Z-groove ratio than the ventricle (ventricular-type). The remaining 12% of cells showed a mixed structure of each subtype (mixed-type). The LFs-, ventricular-, and mixed-type had an appreciable amount of reticular form of intracellular T-tubules. Formamide-induced detubulation effectively removed atrial T-tubules, which was confirmed by both confocal images and decreased cell capacitance. However, the LFs remained intact after detubulation. Detubulation reduced action potential duration and L-type Ca2+ channel (LTCC) density, and prolonged relaxation time of the myocytes. Taken together, we observed heterogeneity of rat atrial T-tubules and membranous ultrastructure, and the alteration of atrial EC-coupling by disruption of T-tubules.

Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as limb girdle muscular dystrophy type 2L (LGMD2L) and Miyoshi muscular dystrophy type 3 (MMD3) in human. However, the molecular mechanisms of the skeletal myopathies caused by ANO5 defects are poorly understood. To understand the role of ANO5 in skeletal muscle development and function, we silenced the ANO5 gene in C2C12 myoblasts and evaluated whether it impairs myogenesis and myotube function. ANO5 knockdown (ANO5-KD) by shRNA resulted in clustered or aggregated nuclei at the body of myotubes without affecting differentiation or myotube formation. Nuclear positioning defect of ANO5-KD myotubes was accompanied with reduced expression of Kif5b protein, a kinesin-related motor protein that controls nuclear transport during myogenesis. ANO5-KD impaired depolarization-induced [Ca²⁺]i transient and reduced sarcoplasmic reticulum (SR) Ca²⁺ storage. ANO5-KD resulted in reduced protein expression of the dihydropyridine receptor (DHPR) and SR Ca²⁺-ATPase subtype 1. In addition, ANO5-KD compromised co-localization between DHPR and ryanodine receptor subtype 1. It is concluded that ANO5-KD causes nuclear positioning defect by reduction of Kif5b expression, and compromises Ca²⁺ signaling by downregulating the expression of DHPR and SERCA proteins.
Active Transport, Cell Nucleus ; Calcium Channels, L-Type ; Cell Membrane ; Chloride Channels ; Humans ; Muscle Development ; Muscle Fibers, Skeletal ; Muscle, Skeletal ; Muscular Diseases ; Muscular Dystrophies ; Muscular Dystrophies, Limb-Girdle ; Myoblasts ; RNA, Small Interfering ; Ryanodine Receptor Calcium Release Channel ; Sarcoplasmic Reticulum

PURPOSE: Tumor regression grade (TRG) is predictive of therapeutic response in rectal cancer patients after chemoradiotherapy (CRT) followed by curative resection. However, various TRG systems have been suggested, with subjective categorization, resulting in interobserver variability. This study compared the prognostic validity of four different TRG systems in order to identify the most ideal TRG system. MATERIALS AND METHODS: This study included 933 patients who underwent preoperative CRT and curative resection. Primary tumors alone were graded according to the American Joint Committee on Cancer (AJCC), Dworak, and Ryan TRG systems, and both primary tumors and regional lymph nodes were graded according to a modified Dworak TRG system. The ability of each TRG system to predict recurrence-free survival (RFS) and overall survival (OS) was analyzed using chi-square and C statistics. RESULTS: All four TRG systems were significantly predictive of both RFS and OS (p < 0.001 each), however none was a better predictor of prognosis than ypStage. Among the four TRGs, the mDworak TRG system was a better predictor of RFS and OS than the AJCC, Dworak, and Ryan TRG systems, and both the chi-square and C statistics were higher for the former, although the differences were not statistically significant. The combination of ypStage and the modified Dworak TRG better predicted RFS and OS than ypStage alone. CONCLUSION: The modified Dworak TRG system for evaluation of entire tumors including regional lymph nodes is a better predictor of survival than current TRG systems for evaluation of the primary tumor alone.
Chemoradiotherapy* ; Humans ; Joints ; Lymph Nodes ; Observer Variation ; Prognosis ; Rectal Neoplasms*

PURPOSE: The objective of this study is to evaluate the relationship of atheroembolic risk factors with postoperative recovery of renal function after on-clamp partial nephrectomy (PN) with warm ischemia in patients with staged T1-2 renal cell carcinoma (RCC). MATERIALS AND METHODS: A total of 234 patients from 2004 to 2012 were included, and their clinicopathologic and operative parameters, including atheroembolic risk factors were reviewed retrospectively. Renal function, as determined by estimated glomerular filtration rate (eGFR) and measurement of serum creatinine level (Cr) at each scheduled follow-up for a median four years, was compared between the high-risk (HR) group (n=49, > or = five risk factors) and the low-risk (LR) group (n=185, < five risk factors). RESULTS: Except for baseline renal function and number of risk factors for atheroembolism, differences in characteristics between groups were comparatively insignificant. At 3 months after the operation, Cr and eGFR differed significantly between the two groups (p < 0.05), but no differences were observed afterward. Significant deterioration from baseline in Cr and eGFR was observed in both groups at 1 month after the operation, with a greater change in the HR group (p < 0.05). From measurement to measurement, significantly faster deterioration in Cr and eGFR was observed in the HR group than in the LR group until 6 months after the operation (Cr: LR, 0.02 mg/dL and HR, 0.13 mg/dL; eGFR: LR, 1.50 mL/min/1.73 m2 and HR, 6.38 mL/min/1.73 m2; p < 0.05). CONCLUSION: The presence of atheroembolic risk factors may negatively influence postoperative recovery of renal function after PN in patients with localized RCC.
Atherosclerosis ; Carcinoma, Renal Cell* ; Creatinine ; Embolism ; Embolism, Cholesterol ; Follow-Up Studies* ; Glomerular Filtration Rate ; Humans ; Nephrectomy* ; Retrospective Studies ; Risk Factors* ; Warm Ischemia

Chylothorax is the accumulation of chyle-containing lymphatic fluid within the pleural space. It is mainly caused by injury or obstruction of the thoracic duct due to neoplasm or trauma. There have been several reports of chylothorax associated with chromosomal anomaly such as Down syndrome. Most cases are congenital, and development of chylothorax in an adult with Down syndrome is rare. Here, we report a case of chylothorax in an adult with Down syndrome who had been treated with mechanical ventilation. A 31-year-old woman with Down syndrome was admitted with urosepsis. She was treated with mechanical ventilation due to severe respiratory acidosis. Four days after mechanical ventilation, she developed unilateral pleural effusion, and analysis indicated chylothorax. After conservative treatment, including fasting and total parenteral nutritional support, the chylous formation completely disappeared.
Acidosis, Respiratory ; Adult ; Chylothorax ; Down Syndrome ; Fasting ; Female ; Humans ; Nutritional Support ; Pleural Effusion ; Respiration, Artificial ; Thoracic Duct ; Wounds, Nonpenetrating

Colonoscopy is a widely used diagnostic and therapeutic intervention with an excellent safety profile. Although an intraperitoneal hemorrhage is a rare complication after colonoscopy, and usually associated with splenic injury or solid organ pathology, it is potentially serious and can be life-threatening. We report a rare case of spontaneous intraperitoneal hemorrhage after diagnostic colonoscopy without splenic injury or intra-abdominal abnormality, known as idiopathic spontaneous intraperitoneal hemorrhage. This case emphasizes that physicians should be aware of the emergence of acute abdomen after colonoscopy.
Abdomen ; Abdomen, Acute ; Colonoscopy ; Hemoperitoneum ; Hemorrhage ; Spleen

Phytobezoars are the most common bezoars composed of non-digestible food materials, such as fiber, seeds, skin of fruits. The predisposing factors of bezoars are altered gastrointestinal motility and anatomy. It is uncommon for bezoars occurring in patient with normal gastric anatomy to cause impaction on the duodenal bulb. We experienced a phytobezoar at the duodenal bulb causing gastric outlet obstruction in a patient who had no predisposing factors. The patient was treated by endoscopic removal.
Bezoars ; Duodenum ; Fruit ; Gastric Outlet Obstruction ; Gastrointestinal Motility ; Humans ; Seeds ; Skin

Vitamin C, one of essential micronutrients, has been reported to modulate the humoral immune responses in some mammals. We investigated whether vitamin C might modulate this response in mice by directly affecting B cells. Splenic B cells were isolated and activated by CD40- and B cell receptor-ligation in vitro. The cells were cultured with a pretreatment of vitamin C from 0 to 1 mM of concentrations. Vitamin C slightly increased apoptosis of B cells dose-dependently and behaved as an antioxidant. We found that in vivo administration of vitamin C by intraperitoneal injection affected isotype switching as previously reported: the titer of antigen-specific IgG1 antibody was decreased, while that of IgG2a was unaffected. Somewhat different from those observed in vivo, in vitro exposure to vitamin C slightly decreased isotype switching to IgG1 and increased isotype switching to IgG2a. Pretreatment with vitamin C in the safe range did not affect either proliferation of cultured B cells or the expression of CD80 and CD86 in those cells. Taken together, in vivo results suggest that vitamin C acts to modulate isotype switching in the mouse. However, because of our in vitro results, we suggest that the modulation exerted by vitamin C in vivo is by indirectly affecting B cells, perhaps by directly influencing other immune cells such as dendritic cells.
Animals ; Apoptosis ; Ascorbic Acid ; B-Lymphocytes ; Dendritic Cells ; Immunity, Humoral ; Immunoglobulin Class Switching ; Immunoglobulin G ; Injections, Intraperitoneal ; Mammals ; Mice ; Micronutrients ; Reactive Oxygen Species ; Vitamins

Although assisted reproductive technology is associated with higher rates of interstitial pregnancy and heterotopic pregnancy, heterotopic pregnancy after bilateral salpingectomy is still extremely rare. We report a case of heterotopic pregnancy after bilateral salpingectomy in an in vitro fertilization/embryo transfer patient, who underwent cornual resection by laparotomy due to ruptured cornual pregnancy. However, 3 days after surgery, the remaining intrauterine pregnancy miscarried, and a dilatation and curettage was performed.
Dilatation and Curettage ; Embryo Transfer ; Embryonic Structures ; Female ; Fertilization in Vitro ; Humans ; Laparotomy ; Pregnancy ; Pregnancy, Heterotopic ; Reproductive Techniques, Assisted ; Salpingectomy