The Hirosaki hairless rat (HHR) is a mutant strain spontaneously derived from the Sprague-Dawley rat (SDR) and its inheritance is autosomal recessive. Our recent study has revealed that an 80-kb genomic DNA on 7q36 containing basic hair keratin genes, Kb21, Kb23, Kb26 and Krt2-25, is deleted in HHR. To characterize hair follicles in HHR, progression of hair cycle and expression profiles of basic hair keratins were immunohistochemically studied and compared with those of SDR. The HHR exhibited sparse hairs and their twisted hairs were shorter than SDR hairs. HHR hair follicles entered the catagen phase earlier than SDR and massive destruction of HHR hair follicles and infiltration of inflammatory cells occurred in the catagen phase. In HHR the hair medulla was enlarged and the inner root sheath was thinned while the hair cortex was formed where Kb25 was expressed. In SDR Kb25 was expressed in the hair matrix and medulla. Electron microscopy indicated loss of the cuticle in HHR. These results suggest that hypotrichosis of HHR is due to the deletion of hair keratin genes and expression of a keratin fusion gene. Thus, HHR seems to be a useful model to examine the role of hair keratins in the hair follicle formation.
Placental/umbilical cord blood (CB) containing hematopoietic stem cells are increasingly used in basic medical research, regenerative research and hematopoietic stem cell transplantation. CB is no longer considered a biological waste product, and its importance is increasing. Over the past decade, we have investigated various aspects of hematopoiesis using CD34+ cells obtained from CB which were collected at a single birth center. The purpose of this study is to examine the possibility of conducting CB collection at birth centers, while also describing the challenges of CB collection at birth centers. A total of 470 CB units obtained from single-birth and normal vaginal deliveries were analyzed. The outline of mothers and babies was closely similar to the domestic average
birth. The mean net weight of the CB collected was 54.2 g. According to a multivariate regression analysis, the placental weight, placental volume, neonatal weight, the presence of meconium in the amniotic fluid and cord length all had a significant effect on the net weight CB. These results are consistent with the findings of most previous reports. The present study demonstrates that such birth centers can both safely and effectively collect CB.
We showed that endogenous prostacyclin inhibitor coupling factor 6 (CF6) is released from vascular endothelial cells and its release is stimulated by tumor necrosis factor-α, which is related to congestive heart failure (CHF). We also showed that CF6 increases the gene expression related to CHF. To investigate the role of CF6 in the genesis of CHF, we generated CF6-overexpressing transgenic (TG) mice, and characterized the phenotype. DNA fragment consisting of human elongation factor 1α promoter, and human calcitonin/CF6 fused gene was injected into the embryo of C57BL/6J mouse, and homozygous TG mice were generated. In TG mice, CF6 gene was overexpressed by two fold in overall tissues compared with wild type (WT) mice. Under normal salt diet, blood pressure, heart rate, and the expression of energy metabolism-related genes were similar between TG and WT mice. When the mice were fed with 8% -salt diet for 35 weeks, the mortality of TG mice was higher than that of WT mice (survival rate; 50% in TG versus 92% in WT, p<0.05 by log-rank test). This preliminary report indicates that further examination, especially analysis of the cardiac function, is needed to clarify the cause of high mortality of TG mice under high salt intake.
In the present study, we have conducted cDNA microarray in C6, rat brain glioma cell line, to assess anti-inflammatory effects of ketamine and sevoflurane in the central nervous system. The cultured C6 cells were treated with ketamine （0-100 μM） and sevoflurane (0 and 0.66 mM). Total RNA was extracted from the cells and labeled with fluorescent dye and then hybridized with microarray slide, containing 1936 genes. Quantitative analysis of each gene expression was confirmed by real-time polymerase chain reaction (PCR). Microarray analyses showed that ketamine downregulated the expression of 4 proinflammatory cytokine genes and upregulated that of 2 anti-inflammatory cytokine genes. On the other hand, sevoflurane downregulated the expression of 2 proinflammatory cytokines but upregulated that of two other proinflammatory cytokines. Furthermore, sevoflurane failed to stimulate the expressions of anti-inflammatory cytokines. Although patterns of cytokine expression in response to ketamine and sevoflurane were different from each other described above, both anesthetics downregulated a key cytokine, interleukin (IL)-1β remarkably in microarray analysis, which was confirmed by real time PCR. These results suggest that both ketamine and sevoflurane show mainly anti-inflammatory properties through the inhibition of IL-1β.
Insulin-like growth factor (IGF)-1 is known to exert beneficial effects on the heart, but its source and function under hypoxia are unknown. We investigated the effect of hypoxia on IGF-1 expression and its role in the regeneration in the heart. Cardiac myocytes and fibroblasts obtained from neonate mice heart were cultured and exposed to hypoxia. mRNA of IGF-1, IGF-binding protein 3 (IGFBP3), and vascular endothelial growth factor-A (VEGF-A) was measured by real-time PCR. In cardiac myocytes, IGF-1 mRNA was increased by 3.5 ± 1.1 fold at 3 hours after hypoxia concomitantly with the increase in IGFBP3 and VEGF-A mRNA, and returned to the baseline at 24 hours. In contrast, IGF-1 mRNA in cardiac fibroblasts was unchanged by hypoxia, although VEGF-A mRNA was increased. To investigate the role of IGF-1 in the heart regeneration, we measured the gene expressions of stromal cell-derived factor-1 (SDF-1), its receptor CXCR4, and matrix metalloproteinase (MMP)-14 related to cell homing. In cardiac myocytes, SDF-1 and MMP-14 mRNA were increased at 3 hours after hypoxia and tended to be positively correlated with IGF-1 mRNA. These suggest that hypoxia increases IGF-1 expression in cardiac myocytes, and this endogenous IGF-1 may exert beneficial effects on regeneration in the heart.
Structural remodeling occurs in diverse heart diseases and affects their clinical courses. We reported that amiodarone suppresses both electrical and structural remodeling in a canine persistent atrial fibrillation model. As a mechanism for amiodarone's effect on structural remodeling, we suggested its inhibitory effect on matrix metalloproteinase (MMP) activity. To elucidate it, we investigated the effect of amiodarone on MMP activity in a rat myocardial infarction model created by left coronary artery (LCA) ligation. Adult Sprague-Dawley rats were divided into sham-operated (Sham), sham-operated with amiodarone (Sham+AMD), LCA-ligated without amiodarone (MI) and LCA-ligated with amiodarone rats (MI+AMD). Amiodarone (20 mg/kg/day) was administered for 2 weeks before and for 4 weeks after operation. The hearts were excised at 4 weeks after operation. MMP-2 activity was measured by gelatin zymography. At 4 weeks after surgery, left ventricular fractional shortening was decreased in
MI but not in MI+AMD rats. There was no difference in the infarct size between MI and MI+AMD rats (P=NS). As compared with Sham, MMP-2 activity was increased in MI (P<0.01), but not in MI+AMD (P=NS versus Sham; P<0.05 versus MI). MMP-2 activity was not increased in Sham+AMD (P=NS). Thus, amiodarone exerts an inhibitory effect on MMP activity. This may be related to the improvement left ventricular function in MI rats.
The aim of this study was to determine the time course and mechanism of hypoxia-induced pancreatic islet dysfunction. Islets isolated from Sprague Dawley rats were cultured in 1% O₂ (hypoxia). Glucose stimulated insulin secretion (GSIS) was then examined for islets in either static or perifused cultures, followed by an evaluation of mitochondrial activity and islet cell death. Additionally, we examined the effect of culturing previously hypoxic islets for an additional 24 h under normoxia to determine whether the hypoxic effects were reversible and to assess the effects of re-oxygenation on GSIS. In the static islet culture, insulin secretion declined significantly after 24 h. In perifused islets, the area under the curve (AUC) of first-phase GSIS declined significantly after 6 h, while the AUC of second-phase GSIS decreased significantly after 12 h. Mitochondrial activity dropped markedly after 48 h, but cell death assays revealed that apoptosis did not increase in the time period from 6 h to 48 h. However, necrosis increased significantly after 24 h. In the re-oxygenation study, the return to normoxia significantly worsened the decline in GSIS. In conclusion, exposure to hypoxia first causes functional disorder in the islets, followed by cell death due to necrosis rather than apoptosis. Furthermore, re-oxygenation aggravated islet dysfunction.
The localizations of nonheme-Fe (III) and Fe (II) were studied in the hypothalamo-neurohypophyseal system of the rat brain by light and electron microscopic nonheme iron-histochemistry. Fe (III)-deposit was heavily accumulated in the parvocellular part of the hypothalamic paraventricular nucleus (HPV), where numerous glias were stained. Fe (III)-deposit heavily filled the cytosol and lysosomes of microglia-, oligodendrocyte- and astrocyte-like cells, while neurons contained only a small number of Fe (III)-laden lysosomes. Fine processes of Fe (III)- laden microglia- and oligodendrocyte-like cells closely ensheathed the cell body and proximal dendrites of neurons. Fe (III)-laden astrocytelike cells tightly enclosed the capillary wall. The magnocellular part of the HPV and the supraoptic nucleus were less intensely stained than the parvocellular part of the HPV. The secretory axon terminals in the outer lamina of the median eminence (ME) and the posterior pituitary including the Herring bodies contained Fe (III)-laden small lysosomes among densely aggregated secretory granules. The secretory axon terminals in the ME were tightly enclosed by heavily Fe (III)-laden processes of tanycyte. The heavily Fe (III)-laden pituicytes and interstitial, pericapillary phagocytes closely approached the secretory axon terminals in the posterior pituitary. Fe
(II) was largely localized in the lysosomes throughout the hypothalamo-neurohypophyseal system.
Two- and three-dimensional motion analysis methods are commonly used for the measurement of dynamic lower limb alignment. However, there has been very few comparative studies between these two methods. The purpose of the present study was to investigate the correlation of the biomechanical data between two- and three-dimensional motion analysis methods for the evaluation of dynamic knee alignment. Seven female and 7 male college basketball players were recruited to perform a drop jump test. The Knee/Hip ratio for evaluation of valgus alignment of the knee in the coronal plane was measured by a two-dimensional motion analysis system with a digital video camera. The joint kinematics and kinetics of the knee were evaluated by a three-dimensional motion analysis system. From toe touch to maximum knee flexion, the knee/hip ratio decreased significantly both in males and females. However, the knee valgus angle and the peak knee valgus moment were not correlated with change in the knee/hip ratio. Both males and females showed a similar change in the knee/hip ratio in the two-dimensional motion analysis during the drop jump, but significant differences in joint kinematic and kinetic patterns were seen in the three-dimensional motion analysis. These differences should be taken into account when using the two different motion analysis systems.
To examine the effect of chronic hypertension on endothelium-derived hyperpolarizing factor (EDHF) responses, the hearts of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were isolated and perfused using Langendorff system with constant perfusion pressure. Bradykinin increased coronary flow (CF) dose-dependently and this was not affected by NG-nitro-L-arginine methyl ester or indomethacin, indicating that bradykinin's effect on CF was not mediated by nitric oxide or prostacyclin but by EDHF. Bradykinin-induced CF increase was smaller in SHR than in WKY. Tetrabutylammonium (a non-specific KCa channel blocker) abolished bradykinin-induced CF increase in both rats. 1-Ethyl-2-benzimedazolinone (1-EBIO, an agonist of intermediate conductance KCa channel)-induced increase in CF was smaller in SHR than in WKY. 1,3-Dihydro-1-[2-hydroxy-5-(trifluoromethyl) phenyl]-5-(trifluoromethyl)-2H-benzimidazol-2-one (NS1619, an agonist of large conductance KCa channel)-induced increase in CF did not differ between SHR and WKY. In early stage of hypertension, there was no significant difference between SHR and WKY in bradykinin- and 1-EBIO-induced increases in CF. In conclusion, EDHF response in coronary microcirculation is impaired in SHR due to dysfunction of intermediate-conductance calcium-activated potassium channels.
We report a rare case of esophageal schwannoma. The patient was a 41-year-old man who was admitted to our hospital due to chest oppression. Chest imaging showed a solid mass in the middle mediastinum compressing the esophagus and the trachea. Neurogenic tumor was suspected and the patient underwent extirpation of the tumor through right thoracotomy. The tumor, 4.5×4.3×3.4 cm in size, was strongly attached to the esophageal wall.
Pathological examination revealed myxomatous pattern in the tumor. Immunohistochemical staining for S-100 protein
was positive and the diagnosis of schwannoma was made. The majority of mediastinal schwannomas arise from
sympathetic nerve cells in the posterior mediastinum. Esophageal schwannoma is rare and only 27 cases were reported
in literature to date.