Immunolocalization of basic fibroblast growth factor during wound repair in rat retina after laser photocoagulation

Background: Basic fibroblast growth factor (bFGF) stimulates the mitogenesis of various cells and plays a key role in wound repair. We studied the immunohistochemical localization of bFGF during wound repair in the rat retina after laser photocoagulation. Methods: Krypton laser photocoagulation was performed on the eyes of pigmented rats. The eyes were enucleated on days 1, 3, 7, 14 and 28 after the photocoagulation, and the immunohistochemical localization of bFGF was assessed. Two different monoclonal antibodies and one polyclonal antibody against bFGF as first antibodies were used. Results: Marked immunoreactivity for bFGF was found in the ganglion cell layer, and weak immunoreactivity for bFGF was found in the retinal pigment epithelial (RPE) cells of the normal adult rat retina. On day 3 after laser photocoagulation, the nuclei and cytoplasm of proliferating RPE cells at the center of the photocoagulated lesion showed intense bFGF immunoreactivity. The nuclei of RPE cells around the lesion showed intense bFGF immunoreactivity. Macrophages that migrated into the lesion showed positive staining for bFGF. These immunoreactivity decreased with time. Controls (0.05 M Tris-HCl buffer, normal serum, or these same antibodies preabsorbed with bFGF) did not show positive staining. Conclusion: The finding of an elevated expression of bFGF immunoreactivity in the photocoagulated lesion suggests that bFGF may play a role in wound repair in the rat retina after laser photocoagulation.     

Thrombin inhibitor ameliorates secondary damage in rat brain injury: suppression of inflammatory cells and vimentin-positive astrocytes

The effects of the thrombin inhibitor argatroban on the number of inflammatory cells and reactive astrocytes were investigated in a rat brain injury model. Gelatin sponge soaked with thrombin inhibitor (treatment group) or saline (control group) was placed in the brain defect to assess the infiltration of inflammatory cells by hematoxylin-eosin and immunohistochemical staining. Expression of polymorphonuclear leukocytes (PMNs) and monocyte/macrophage (Mo/Mo) cells, and vimentin (VIM)-positive astrocytes and glial fibrillary acidic protein (GFAP)-positive astrocytes were compared between groups. In the treatment group, infiltration of both PMNs and Mo/Mo cells, and the number of VIM-positive astrocytes were significantly reduced, but the number of GFAP-positive astrocytes was not different from the control group. Thrombin inhibitor suppresses the infiltration of inflammatory cells and excessive gliosis caused by VIM-positive astrocytes, but not expression of GFAP-positive astrocytes, suggesting minimization of secondary brain damage and promotion of the conditions required for neural regeneration.     

Patent ductus venosus with a hypoplastic intrahepatic portal system presenting intrapulmonary shunt: a case treated with banding of the ductus venosus

A case of patent ductus venosus (PDV) presenting intrapulmonary shunting is described. Although retrograde venography of ductus venosus showed few intrahepatic branches, banding of PDV resulted in increased intrahepatic portal branches and disappearance of symptoms 10 months after the operation. Banding of the ductus venosus may be effective in PDV even with hypoplastic intrahepatic portal system.     

Prolonged oral treatment with an essential amino acid L-leucine does not affect female reproductive function and embryo-fetal development in rats.

L-leucine, an essential amino acid, is one of the most popular ingredients in dietary supplements. To investigate a possibility of its embryo-fetal toxicity in rats, 11- to 12-week old dams were orally administered an aqueous solution of L-leucine at doses of 300 or 1000 mg/kg body weight on gestational days 7-17. Body weight and feed intake was evaluated throughout the whole course of pregnancy (days 0-20). L-Leucine did not influence body weight, but at a dose of 1000 mg/kg, slightly enhanced feed intake on days 14 and 18 of pregnancy. Caesarean section (day 20) revealed no influences on the litter size and weight of live-born fetuses, the number of corpora lutea, implantation index or the quality of placenta, and the minor increase in feed intake was considered irrelevant to the pregnancy outcomes. Fetuses were evaluated in a battery of external, visceral and skeletal examinations. No effects of L-leucine on gender ratio and external abnormalities, and no significant treatment-related variations in visceral and skeletal pathologies were observed. These results suggested that L-leucine, administered orally during organogenesis at doses up to 1000 mg/kg body weight, did not affect the outcome of pregnancy and did not cause fetotoxicity in rats.     

Tumor endothelial cells with high aldehyde dehydrogenase activity show drug resistance

Tumor blood vessels play an important role in tumor progression and metastasis. We previously reported that tumor endothelial cells (TEC) exhibit several altered phenotypes compared with normal endothelial cells (NEC). For example, TEC have chromosomal abnormalities and are resistant to several anticancer drugs. Furthermore, TEC contain stem cell‐like populations with high aldehyde dehydrogenase (ALDH) activity (ALDH^high TEC). ALDH^high TEC have proangiogenic properties compared with ALDH^low TEC. However, the association between ALDH^high TEC and drug resistance remains unclear. In the present study, we found that ALDH mRNA expression and activity were higher in both human and mouse TEC than in NEC. Human NEC:human microvascular endothelial cells (HMVEC) were treated with tumor‐conditioned medium (tumor CM). The ALDH^high population increased along with upregulation of stem‐related genes such as multidrug resistance 1, CD90, ALP, and Oct‐4. Tumor CM also induced sphere‐forming ability in HMVEC. Platelet‐derived growth factor (PDGF)‐A in tumor CM was shown to induce ALDH expression in HMVEC. Finally, ALDH^high TEC were resistant to fluorouracil (5‐FU) in vitro and in vivo. ALDH^high TEC showed a higher grade of aneuploidy compared with that in ALDH^low TEC. These results suggested that tumor‐secreting factor increases ALDH^high TEC populations that are resistant to 5‐FU. Therefore, ALDH^high TEC in tumor blood vessels might be an important target to overcome or prevent drug resistance.     

Novel oral transforming growth factor‐β signaling inhibitor EW‐7197 eradicates CML‐initiating cells

Recent strategies for treating CML patients have focused on investigating new combinations of tyrosine kinase inhibitors (TKIs) as well as identifying novel translational research agents that can eradicate CML leukemia‐initiating cells (CML‐LICs). However, little is known about the therapeutic benefits such CML‐LIC targeting therapies might bring to CML patients. In this study, we investigated the therapeutic potential of EW‐7197, an orally bioavailable transforming growth factor‐β signaling inhibitor which has recently been approved as an Investigational New Drug (NIH, USA), to suppress CML‐LICs in vivo. Compared to TKI treatment alone, administration of TKI plus EW‐7197 to CML‐affected mice significantly delayed disease relapse and prolonged survival. Notably, combined treatment with EW‐7197 plus TKI was effective in eliminating CML‐LICs even if they expressed the TKI‐resistant T315I mutant BCR‐ABL1 oncogene. Collectively, these results indicate that EW‐7197 may be a promising candidate for a new therapeutic that can greatly benefit CML patients by working in combination with TKIs to eradicate CML‐LICs.     

Inverse agonist activity of sarpogrelate, a selective 5-HT2A-receptor antagonist, at the constitutively active human 5-HT2A receptor

Mutations producing constitutively active G-protein coupled receptors have been found in the pathophysiology of several diseases, implying that inverse agonists at the constitutively active receptors may have preferred therapeutic applications. Because of the involvement of 5-HT(2A) receptors in mediating many cardiovascular diseases, constitutively active mutants of the 5-HT(2A) receptor may be responsible for the disease states. Thus, the purpose of the present study was to investigate the inverse agonist activity of sarpogrelate, a selective 5-HT(2A)-receptor antagonist, and its active metabolite, M-1; and we compared their activities with those of other 5-HT(2A)-receptor antagonists such as ritanserin, ketanserin, and cyproheptadine. Using a constitutively active mutant (C322K) of the human 5-HT(2A) receptor, we demonstrated that like other 5-HT(2A)-receptor antagonists, sarpogrelate acts as a potent inverse agonist by significantly reducing basal inositol phosphate levels. However, there were no significant differences between sarpogrelate and other 5-HT(2A)-receptor antagonists for their inverse agonist activity. Compared with the wild type receptor, mutant receptor displayed significantly higher affinity for 5-HT and lower affinity for sarpogrelate. These results indicate that stabilization of the inactive conformation of the 5-HT(2A) receptor may be a key component of the mechanism of action of sarpogrelate.     

Relationship between perfusion index and central temperature before and after induction of anesthesia in laparoscopic gastrointestinal surgery: A prospective cohort study

The perfusion index (PI) cutoff value before anesthesia induction and the ratio of PI variation after anesthesia induction remain unclear. This study aimed to clarify the relationship between PI and central temperature during anesthesia induction, and the potential of PI in individualized and effective control of redistribution hypothermia. This prospective observational single center study analyzed 100 gastrointestinal surgeries performed under general anesthesia from August 2021 to February 2022. The PI was measured as peripheral perfusion, and the relationship between central and peripheral temperature values was investigated. Receiver operating characteristic curve analysis was performed to identify baseline PI before anesthesia, which predicts a decrease in central temperature 30 minutes after anesthesia induction, and the rate of change in PI that predicts the decrease in central temperature 60 minutes after anesthesia induction. In cases with a central temperature decrease of ≥ 0.6°C after 30 minutes, the area under the curve was 0.744, Youden index was 0.456, and the cutoff value of baseline PI was 2.30. In cases with a central temperature decrease of ≥ 0.6°C after 60 minutes, the area under curve was 0.857, Youden index was 0.693, and the cutoff value of the PI ratio of variation after 30 minutes of anesthesia induction was 1.58. If the baseline PI is ≤ 2.30 and the PI 30 minutes after anesthesia induction is at least 1.58-fold the PI ratio of variation, there is a high probability of a central temperature decrease of at least 0.6°C within 30 minutes after 2 time points.