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High salt intake induces hypertension and enhances stroke onset. However, whether an increase in brain sodium exposure itself is harmful and has poor prognosis remains unknown. Therefore, we employed hypertensive rats that underwent intracerebroventricular (ICV) infusion of sodium for 28 days and evaluated stroke onset and related cytotoxic brain injuries. Forty-seven spontaneously hypertensive stroke-prone (SHRSP) and 39 normotensive rats (Wistar Kyoto rats [WKY]) underwent persistent ICV infusion of the following four solutions: artificial cerebrospinal fluid, 0.9%, 2.7%, and 9% saline for 28 days. We evaluated stroke onset and all-cause mortality between SHRSP and WKY at each ICV sodium concentration as the primary endpoints. Our secondary objective was to explore histological brain injuries associated with SHRSP induced by high sodium ICV. The results indicated that ICV infusion of 2.7% and 9% sodium showed a significant increase in stroke onset, decrease in body weight, and increase rate of brain water content in SHRSP compared to WKY. Increased blood pressure was not observed for ICV infusion of high sodium, while serum sodium concentration was significantly increased in SHRSP compared to WKY. Histological evaluations revealed that higher sodium infusion significantly increased the number of activated microglia, superoxide, neuronal cell loss, and microbleeds compared to WKY and SHRSP with 0.9% sodium. We conclude that persistent exposure to high sodium in the brain is one of the risk factors for stroke onset upregulating cerebral microbleeds and oxidative stress in hypertensive rats., (© 2023. The Author(s), under exclusive licence to The Japanese Society of Hypertension.)

The coronavirus disease (COVID-19) pandemic has led to a dramatic increase in facemask use. Consequently, it has been reported that exhaled airflow toward the eyes can cause the dispersal of bacteria into the eyes, potentially increasing the incidence of postoperative endophthalmitis. In addition to wearing a facemask, gaps between the surgical drape and skin can also direct exhaled airflow toward the eyes. Here, we aimed to examine how the risk of contamination varies depending on the state of the drapes. We used a carbon dioxide imaging camera to visualize changes in exhaled airflow under different drape conditions and a particle counter to evaluate changes in the number of particles around the eye. The results revealed airflow present around the eye and a significant increase in the number of particles when the nasal side of the drape was detached from the skin. However, when a metal rod called "rihika" was used to create space above the body, the airflow and number of particles were significantly reduced. Thus, if drape coverage becomes incomplete during surgery, exhaled airflow toward the eye may contaminate the surgical field. On hanging up the drape, airflow can escape in the direction of the body, potentially preventing contamination., (© 2023. The Author(s).)

Intravitreal injection (IVI) of anti-vascular endothelial growth factor (VEGF) is the standard treatment modality in various types of retinal diseases. However, endophthalmitis remains the most serious complication. Despite the lack of evidence that antibiotics prevent endophthalmitis, topical antibiotics are still used routinely in Japan. We conducted a retrospective multicenter study by analyzing records from patients who underwent IVI of anti-VEGF agents with or without antibiotic treatment. In the analysis of a total of 147,440 eyes, the incidence of endophthalmitis was 0.007%: 0.005% with no use of antibiotics, 0.009% with antibiotic pretreatment, 0.012% with posttreatment, and 0.005% with pre- and posttreatment. There was no statistically significant difference among the four groups (chi-square test, p = 0.57). Most facilities used masks, sterilized gloves, and drapes. Nine of the 10 eyes that developed endophthalmitis received topical antibiotics, and all infected eyes underwent IVI with aflibercept, not the prefilled syringe delivery system. In four patients who received multiple IVI, the detection of causative bacteria revealed resistance to used antibiotics. Data from this large population, treated with or without antibiotics, suggests that antibiotic prophylaxis does not reduce the rate of endophthalmitis after IVI.

Articular cartilage damage does not heal spontaneously and causes joint dysfunction. The implantation of induced pluripotent stem cell (iPSC)-derived cartilage (iPS-Cart) is one candidate treatment to regenerate the damaged cartilage. However, concerns of tumorigenicity are associated with iPS-Cart, because the iPSC reprogramming process and long culture time for cartilage induction could increase the chance of malignancy. We evaluated the tumorigenic risks of iPS-Cart using HeLa cells as the reference. Spike tests revealed that contamination with 100 HeLa cells in 150 mg of iPS-Cart accelerated the cell growth rate. On the other hand, 150 mg of iPS-Cart without HeLa cells reached growth arrest and senescence after culture, suggesting less than 100 tumorigenic cells, assuming they behave like HeLa cells, contaminated iPS-Cart. The implantation of 10,000 or fewer HeLa cells into joint surface defects in the knee joint of nude rat did not cause tumor formation. These in vitro and in vivo studies collectively suggest that the implantation of 15 g or less iPS-Cart in the knee joint does not risk tumor formation if assuming that the tumorigenic cells in iPS-Cart are equivalent to HeLa cells and that nude rat knee joints are comparable to human knee joints in terms of tumorigenicity. However, considering the limited immunodeficiency of nude rats, the clinical amount of iPS-Cart for implantation needs to be determined cautiously.

Diabetic nephropathy and retinopathy (DR) including diabetic macular edema (DME) are representative microvascular complications of diabetes. We conducted a retrospective multicenter study analyzing records from patients with DR (132 eyes in 70 patients) and end-stage renal diseases (ESRD) who underwent hemodialysis for the first time. We demonstrated that the central retinal thickness (CRT) values were significantly decreased (p < 0.0001), and the best-corrected visual acuity (BCVA) values were improved (p < 0.05) at 1, 3, 6, 9, and 12 months after hemodialysis initiation, in spite of a lack of specific ocular treatments for DME in 93.2% of eyes. We found a significant positive correlation in the rates of CRT changes between right and left eyes. The CRT reductions were greater in eyes with DME type subretinal detachment than in those with spongelike swelling and cystoid macular edema. The visual outcome gain was associated with the CRT reduction at 12 months in the eyes with good initial BCVA (≧20/50). Hemodialysis induction contributed to functional and anatomical improvements after 1 year, independently of initial laboratory values before the hemodialysis.

Neovascular glaucoma (NVG) is a terminal severe complication in eyes with proliferative diabetic retinopathy (PDR), and PDR eyes with vitreous hemorrhage (VH) which undergo vitrectomy may have higher risk of postoperative NVG. The incidence and the prognostic factor of postoperative NVG after 25-gauge vitrectomy with advanced surgical options remain unclear. We retrospectively reviewed medical records of 268 eyes of 268 consecutive PDR patients with VH who underwent 25-gauge vitrectomy and 12 months follow-up at seven centers. Preoperative ocular factors (visual acuity, tractional retinal detachment, panretinal photocoagulation [PRP]), demographics and clinical factors (sex, age, diabetic duration, HbA1c, hypertension, anticoagulant medication, and kidney function), surgical procedures, and postoperative complications were compared between patients who developed postoperative NVG (9.3%) and those who did not. NVG eyes was significantly younger (P = 0.026), had shorter diabetic duration (P = 0.022), higher HbA1c (P = 0.028), absence of PRP (P = 0.039) and higher frequency of postoperative VH (P = 0.0075) than non-NVG eyes. Logistic regression analysis identified postoperative VH (P = 0.014), shorter diabetic duration (P = 0.029), and no PRP (P = 0.028) as prognostic factors for postoperative NVG. This multicenter study indicates that younger age, uncontrolled diabetes, no PRP, and postoperative VH are risk factors of post-vitrectomy NVG.

Uric acid (UA) therapy may prevent early ischemic worsening after acute stroke in thrombolysis patients. The aim of this study was to examine the influence of UA on the thrombolytic efficacy of alteplase in human blood samples by measuring thrombolysis under flow conditions using a newly developed microchip-based flow-chamber assay. Human blood samples from healthy volunteers were exposed to UA, alteplase, or a combination of UA and alteplase. Whole blood and platelet-rich plasma were perfused over a collagen- and thromboplastin-coated microchip, and capillary occlusion was monitored with a video microscope and flow-pressure sensor. The area under the curve (extent of thrombogenesis or thrombolysis) at 30 minutes was 92% lower in the UA-alteplase-treated group compared with the alteplase-treated group. D-dimers were measured to evaluate these effects in human platelet-poor plasma samples. Although hydrogen peroxide significantly decreased the elevation of D-dimers by alteplase, UA significantly inhibited the effect of hydrogen peroxide. Meanwhile, rat models of thromboembolic cerebral ischemia were treated with either alteplase or UA-alteplase combination therapy. Compared with alteplase alone, the combination therapy reduced the infarct volume and inhibited haemorrhagic transformation. UA enhances alteplase-mediated thrombolysis, potentially by preventing oxidative stress, which inhibits fibrinolysis by alteplase in thrombi.

Endocrine and endothelial cells of the anterior pituitary gland frequently make close appositions or contacts, and the secretory granules of each endocrine cell tend to accumulate at the perivascular regions, which is generally considered to facilitate secretory functions of these cells. However, three-dimensional relationships between the localization pattern of secretory granules and blood vessels are not fully understood. To define and characterize these spatial relationships, we used scanning electron microscopy (SEM) three-dimensional reconstruction method based on focused ion-beam slicing and scanning electron microscopy (FIB/SEM). Full three-dimensional cellular architectures of the anterior pituitary tissue at ultrastructural resolution revealed that about 70% of endocrine cells were in apposition to the endothelial cells, while almost 30% of endocrine cells were entirely isolated from perivascular space in the tissue. Our three-dimensional analyses also visualized the distribution pattern of secretory granules in individual endocrine cells, showing an accumulation of secretory granules in regions in close apposition to the blood vessels in many cases. However, secretory granules in cells isolated from the perivascular region tended to distribute uniformly in the cytoplasm of these cells. These data suggest that the cellular interactions between the endocrine and endothelial cells promote an uneven cytoplasmic distribution of the secretory granules.

Gain-of-function mutations in the fibroblast growth factor receptor 3 gene (FGFR3) result in skeletal dysplasias, such as thanatophoric dysplasia and achondroplasia (ACH). The lack of disease models using human cells has hampered the identification of a clinically effective treatment for these diseases. Here we show that statin treatment can rescue patient-specific induced pluripotent stem cell (iPSC) models and a mouse model of FGFR3 skeletal dysplasia. We converted fibroblasts from thanatophoric dysplasia type I (TD1) and ACH patients into iPSCs. The chondrogenic differentiation of TD1 iPSCs and ACH iPSCs resulted in the formation of degraded cartilage. We found that statins could correct the degraded cartilage in both chondrogenically differentiated TD1 and ACH iPSCs. Treatment of ACH model mice with statin led to a significant recovery of bone growth. These results suggest that statins could represent a medical treatment for infants and children with TD1 and ACH.

The c-myc proto-oncogene encodes a transcription factor that promotes cell cycle progression and cell proliferation, and its deficiency results in severely retarded proliferation rates. The ATF3 stress response gene encodes a transcription factor that plays a role in determining cell fate under stress conditions. Its biological significance in the control of cell proliferation and its crosstalk regulation, however, are not well understood. Here, we report that the serum response of the ATF3 gene expression depends on c-myc gene and that the c-Myc complex at ATF/CREB site of the gene promoter plays a role in mediating the serum response. Intriguingly, ectopic expression of ATF3 promotes proliferation of c-myc-deficient cells, mostly by alleviating the impeded G1-phase progression observed in these cells, whereas ATF3 knockdown significantly suppresses proliferation of wild-type cells. Our study demonstrates that ATF3 is downstream of the c-Myc signaling pathway and plays a role in mediating the cell proliferation function of c-Myc. Our results provide a novel insight into the functional link of the stress response gene ATF3 and the proto-oncogene c-myc.

Brain ischemia induces apoptosis in neuronal cells, but the mechanism is not well understood. When wild-type mice were subjected to bilateral common carotid arteries occlusion (BCCAO) for 15 min, apoptosis-associated morphological changes and appearance of TUNEL-positive cells were observed in the striatum and in the hippocampus at 48 h after occlusion. RT-PCR analysis revealed that mRNAs for ER stress-associated proapoptotic factor CHOP and an ER chaperone BiP are markedly induced at 12 h after BCCAO. Immunohistochemical analysis showed that CHOP protein is induced in nuclei of damaged neurons at 24 h after occlusion. In contrast, ischemia-associated apoptotic loss of neurons was decreased in CHOP(-/-) mice. Primary hippocampal neurons from CHOP(-/-) mice were more resistant to hypoxia-reoxygenation-induced apoptosis than those from wild-type animals. These results indicate that ischemia-induced neuronal cell death is mediated by the ER stress pathway involving CHOP induction.

Two new types of macrolide antibiotics, YM-32890 A and B, have been isolated from the fermentation broth of cytophaga sp. YL-02905S. In this paper, the taxonomy of the producing strain, fermentation, isolation, structure elucidation, and biological activity of the antibiotics are reported. YM-32890 A inhibits the growth of staphylococci including a macrolide-resistant strain, but shows no antimicrobial activity against other Gram-positive, Gram-negative bacteria and yeast.

The biochemical basis for the multiple resistance to aminoglycoside antibiotics (AGs) of kasugamycin-producing Streptomyces kasugaensis MB273 was studied. The strain was resistant to a wide range of deoxystreptamine (DOS)-containing AGs as well as astromicin (ASTM) group antibiotics. These AGs strongly inhibited in vitro polyU-directed polyphenylalanine-synthesis using ribosomes from the strain, while they were acetylated and inactivated by the MB273 cell free extract supplemented with acetyl-CoA. It seemed thus likely that the acetyltransferase activity played a critical role for the multiple AG resistance. The acetylation was selective to AGs with 2'-NH2, suggesting the involvement of aminoglycoside 2'-N-acetyltransferase, AAC (2'). Interestingly, the acetylation of istamycin B (ISM-B; an ASTM group AG) resulted in the formation of two different products (1-N-acetyl ISM-B and 2"-N-acetyl ISM-B) at a similar ratio. In this context, an AAC (2') gene cloned as an ISM-B resistance gene from the strain MB273 directed the conversion of ISM-B to only 1-N-acetyl ISM-B. It seemed likely that two types of AACs [AAC(2') and a novel one] were involved in the mechanism of resistance to ASTM group AGs.

Novel antibacterial antibiotics, kalimantacins A, B and C, have been isolated from the fermentation broth of Alcaligenes sp. YL-02632S. In this paper, the taxonomy of the producing strain, fermentation, isolation and biological activities of kalimantacins are reported. Kalimantacins inhibit the growth of Staphylococcus aureus and S. epidermidis including multiple-drug resistant strains.

A new antibacterial antibiotic tetrazomine was found from the fermentation broth of an actinomycete strain which was isolated from beach sand collected at Chichijima, Ogasawara Islands, Tokyo, Japan. The strain Y-09194L, was identified as Saccharothrix mutabilis subsp. chichijimaensis subsp. nov. The antibiotic exhibited broad antimicrobial activity against Gram-positive and Gram-negative bacteria in vitro. It also exhibited strong cytotoxic activity against P388 leukemia cells and showed antitumor activity against P388 leukemia. The apparent molecular formula of tetrazomine was determined as C24H34N4O5. It has a rare structure which consists of six rings including piperidine, piperadine, oxazole, and pyrrolidine.

Okilactomycin, a novel antibiotic, was isolated from the culture filtrate of a strain of actinomycetes. The producing organism, strain YP-02908L, was identified as Streptomyces griseoflavus subsp. zamamiensis subsp. nov. The antibiotic was extracted with ethyl acetate and purified by silica gel column chromatography. It was obtained as colorless prisms from a dichloromethane solution. It exhibited weak antimicrobial activity against Ehrlich ascites carcinoma in vivo. The apparent molecular formula of okilactomycin was determined as C24H32O6. It is a new member of the lactone group antibiotics.

An actinomycete isolate designated as TS-1980 with multiple resistance to aminoglycoside antibiotics was found to produce novel antibiotics. The strain showed taxonomic features identical to the type strain of Nocardiopsis mutabilis except for the temperature range for growth and the utilization of mannitol and raffinose. Based on the capability of growing at lower temperature range, the strain was named N. mutabilis subsp. cryophilis subsp. nov. Physico-chemical and biological characterization of a purified antibiotic revealed its novel polyamine-type nature with a broad antimicrobial activity. The antibiotic was named dopsisamine.

The profile of bioconversion products of istamycin (IS) components by a blocked IS mutant of Streptomyces tenjimariensis that lost IS-productivity suggested a possible biosynthetic pathway of IS similar to that of fortimicin (FT) by Micromonospora olivasterospora. Both organisms are resistant to the antibiotics produced by each other. Based on these similarities, they were examined for their capability to convert an FT-intermediate (FT-B) and IS-intermediates (IS-A0 and -B0) through their biosynthetic pathways. S. tenjimariensis formed 1-epi-FT-B, 2''-N-formimidoyl-FT-A (= dactimicin) and 1-epidactimicin (a new antibiotic) from FT-B. On the other hand, M. olivasterospora converted IS-A0 and -B0 to 2''-N-formimidoyl-IS-A (= IS-A3) and -B (= IS-B3), respectively. Thus, the similarity in antibiotic biosynthesis was confirmed between these FT-group antibiotic-producing organisms. It was also found that the major fermentation product of M. olivasterospora is not FT-A (astromicin) but dactimicin.

Hatomamicin, a new alkaloid antibiotic, was isolated from the culture filtrate of a strain of Saccharopolyspora. The antibiotic was extracted with EtOAc and purified by silica gel column chromatography. The free alkaloid was obtained as pale yellowish prisms from CH3CN solution. It exhibits antimicrobial activity against Gram-positive organisms. The apparent molecular formula of hatomamicin was determined to be C22H31NO5. The structure has been established by a combination of spectroscopic and X-ray crystallographic studies.