The composition of the human fecal microbiota might be significantly associated with fecal SCFA levels under hyperbaric conditions.

The fecal microbiota and short-chain fatty acids (SCFAs) play important roles in the human body. This study examined how hyperbaric conditions affect the fecal microbiota and fecal SCFAs. Fecal samples were obtained from 12 divers at three points during deep-diving training (before the diving training, at 2.1 MPa, and after decompression). At 2.1 MPa, the changes in the frequency of Clostridium cluster IV and fecal iso-valerate levels were positively correlated, and the changes in the frequencies of Bacteroides and Clostridium subcluster XIVa were inversely correlated. After decompression, positive correlations were detected between the changes in the frequency of Bifidobacterium and fecal n-valerate levels and between the changes in the fecal levels of iso-butyrate and iso-valerate. On the other hand, inverse correlations were detected between the changes in the frequency of Clostridium cluster IX and fecal iso-butyrate levels, between the changes in the frequency of Clostridium cluster IX and fecal iso-valerate levels, and between the changes in the frequencies of Bacteroides and Clostridium cluster IV plus subcluster XIVa. During the study period, the changes in fecal iso-butyrate and iso-valerate levels were positively correlated, and inverse correlations were seen between the changes in the frequency of Clostridium cluster IV and fecal propionate levels and between the changes in the frequencies of Prevotella and Clostridium subcluster XIVa. These findings suggest that hyperbaric conditions affect the fecal microbiota and fecal SCFA levels and that intestinal conditions reversibly deteriorate under hyperbaric conditions.

Utility of Hyperbaric Oxygen Therapy for Acute Acoustic Trauma: 20 years' Experience at the Japan Maritime Self-Defense Force Undersea Medical Center

Introduction: Acute acoustic trauma, which is a kind of sensorineural hearing loss, is caused by acoustic overstimulation. Hyperbaric oxygen therapy (HBOT) is reported to be effective against acute acoustic trauma. Objective: We aimed to evaluate the efficacy of HBOT against acoustic hearing loss based on our 20 years of experience with such cases. Methods: Patients who were treated with HBOT for acute acoustic trauma between April 1997 and August 2017 were evaluated in this study. Thirty-five patients with a mean age of 25.7 ± 9.2 (range: 16­48) years were included. Thirty-nine out of 70 ears (35 patients) were damaged. We investigated the initial level of hearing loss; the extent to which hearing recovered; subjective symptoms, such as tinnitus and aural fullness; and the treatment administered. Results: The planned HBOT was completed in 37 of 39 ears. Twenty-six of the 37 ears (70.2%) displayed improved hearing, and 31 of the 37 ears (83.9%) exhibited symptom improvement. Twenty-three (76.7%) and 26 (86.7%) of the 30 ears treated with steroids demonstrated improvements in hearing and subjective symptoms, respectively. Conclusion: A combination of HBOT and steroids should be considered as a treatment for acute acoustic trauma in cases involving symptoms such as tinnitus and aural fullness (AU)

Utility of Hyperbaric Oxygen Therapy for Acute Acoustic Trauma: 20 years' Experience at the Japan Maritime Self-Defense Force Undersea Medical Center.

Introduction Acute acoustic trauma, which is a kind of sensorineural hearing loss, is caused by acoustic overstimulation. Hyperbaric oxygen therapy (HBOT) is reported to be effective against acute acoustic trauma. Objective We aimed to evaluate the efficacy of HBOT against acoustic hearing loss based on our 20 years of experience with such cases. Methods Patients who were treated with HBOT for acute acoustic trauma between April 1997 and August 2017 were evaluated in this study. Thirty-five patients with a mean age of 25.7 ± 9.2 (range: 16-48) years were included. Thirty-nine out of 70 ears (35 patients) were damaged. We investigated the initial level of hearing loss; the extent to which hearing recovered; subjective symptoms, such as tinnitus and aural fullness; and the treatment administered. Results The planned HBOT was completed in 37 of 39 ears. Twenty-six of the 37 ears (70.2%) displayed improved hearing, and 31 of the 37 ears (83.9%) exhibited symptom improvement. Twenty-three (76.7%) and 26 (86.7%) of the 30 ears treated with steroids demonstrated improvements in hearing and subjective symptoms, respectively. Conclusion A combination of HBOT and steroids should be considered as a treatment for acute acoustic trauma in cases involving symptoms such as tinnitus and aural fullness.

Effects of hyperbaric conditions on fecal microbiota.

We aimed to determine whether the composition of the fecal microbiota changes under hyperbaric conditions. In this study, we collected fecal samples from 6 healthy divers at three points during deep diving training (before, 2.1 MPa, end). The frequency of Clostridium cluster XVIII tended to be increased after compression. The frequencies of Clostridium cluster IV and subcluster XIVa were inversely correlated with that of Bacteroides. The compositional changes in the fecal microbiota exhibited interindividual variability. These findings suggest that hyperbaric conditions affect the fecal microbiota.

[A case of ulcerative colitis with preexisting idiopathic thrombocytopenic purpura].

A 53-year-old man was diagnosed as having idiopathic thrombocytopenic purpura (ITP). Hematochezia appeared under steroid therapy for ITP after the diagnosis of ITP 18 months. Colonoscopic study demonstrated inflamed rectal mucosa but there was no evidence of infectious colitis. The colonoscopic and pathological findings were compatible with ulcerative colitis (UC). There have been a few reports of patients with UC complicated by ITP, but in all except one report, UC preceded ITP. This is the third case in which ITP preceded UC and the first case in which the proctitis type of UC was complicated by ITP in Japan.

Overexpression of the neuropilin 1 (NRP1) gene correlated with poor prognosis in human glioma.

We studied whether the expression of the Neuropilin (NRP) gene was correlated with clinicopathological features in glioma. We examined the gene expression of vascular endothelial growth factor (VEGF)-A, Flt-1, KDR, NRP1 and NRP2 in 37 gliomas by real time reverse transcriptase PCR (real time RT-PCR) as well as immunohistochemical analysis. The vascular counts of each tumor were evaluated by anti-CD34 antibody. NRP1 mRNA overexpression was significantly higher in neoplastic tissue compared to normal brain tissue samples. The higher grade of glioma overexpressed the NRP1 gene significantly (p=0.0015). The glioma patients with NRP1 overexpression showed a poorer prognosis (p=0.0202) than those without such overexpression. NRP1 was observed in the glioma cells by immunohistochemical analyses. VEGF-A and VEGFR overexpression did not show any correlation with the clinicopathological features, including NRP expression. These results suggest that NRP1 overexpression, rather than VEGF-A or VEGFR, contributes to tumor progression and has clinical significance for glioma.

Ribozyme mediated down-regulation of thrombospondin receptor CD36 inhibits the growth of the human osteosarcoma cell line.

Thrombospondin-1 (TSP1) is known to possess tumor suppressor functions. In contradiction, TSP1 enhances the stromal vascularization and growth of certain cancers. A cell adhesion receptor, CD36, has been shown to interact with a ligand TSP1. We studied how CD36 affects the growth of the osteosarcoma cell line (HOS) expressing TSP1. We used the anti-CD36 ribozyme to specifically suppress CD36 gene expression in the HOS. The expression of the CD36 mRNA was significantly suppressed in the ribozyme-introduced cell line (HOS/Rz). The transformant HOS/Rz markedly decreased its growth. The growth of the osteosarcoma cell line HOS may be regulated by autocrine or paracrine loop TSP1 and CD36.

Overexpression of the thrombospondin 2 (TSP2) gene modulated by the matrix metalloproteinase family expression and production in human colon carcinoma cell line.

Thrombospondin 2 (TSP2) is an extracellular matrix glycoprotein involved in tumor progression and angiogenesis. We evaluated whether overexpression of the TSP2 gene show an alteration of various genes by cDNA arrays in the colon carcinoma cell line SW480. The transformants with the human TSP2 gene overexpression showed a down-regulation of matrix metalloproteinase 2 (MMP2) and MMP9 in comparison to those with vector-control. Protein production of MMP2 and MMP9 decreased in the transformants overexpressing the TSP2 gene. Conversely, the SW480 transformants showed up-regulation of MMP12 and MMP17. These results suggested that the TSP2 gene is a multifunctional modulator of remodeling tissue in which matrix degradation is required.

Reversal of drug resistance mediated by hammerhead ribozyme against multidrug resistance-associated protein 1 in a human glioma cell line.

We examined the effects of suppressing multidrug resistance-associated protein 1 (MRP1) gene expression in a human glioma cell line U87MG. Hammerhead ribozymes, designed to cleave MRP1 mRNA (alphaMRP1-Rz), were transfected into the U87MG cells. The U87MG/alphaMRP1-Rz cells were significantly sensitive to nitrosourea (ACNU) and doxorubicin (DOX) compared with the U87MG cells (p<0.01 and p<0.05, respectively, unpaired t-test). There was no significant difference in the expression of other human genes between the U87MG/alphaMRP1-Rz and controls by cDNA array. The hammerhead ribozyme-mediated specific suppression of MRP1 was sufficient to reverse the resistance of ACNU and DOX in the human glioma cell line.

Neuropilin 1 and neuropilin 2 co-expression is significantly correlated with increased vascularity and poor prognosis in nonsmall cell lung carcinoma.

BACKGROUND: Cell-retained isoforms of vascular endothelial growth factor A (VEGF-A) have been reported to play an essential role in tumor progression through stromal neovascularization in malignant solid tumors. While more than 95% of nonsmall cell lung carcinoma (NSCLC) expresses cell-retained VEGF-A isoform, the clinicopathologic implications of neuropilin (NRP), considered the specific receptor for limited types of VEGF-A isoform, are not well understood. METHODS: The authors examined NRP1 and NRP2 mRNA expression in 68 NSCLCs and 15 extraneoplastic tissues by a densitometry-assisted, semi-quantitative reverse transcription-polymerase chain reaction. The authors determined the distinct expression of NRPs using the expression level of NRPs relative by optical density to beta2-microglobulin. The authors also investigated VEGF-A isoforms, their receptors, and the clinical implications. Vascularity of NSCLC was morphologically estimated on sections immunostained with anti-CD34 antibody. RESULTS: Eleven of 15 extraneoplastic specimens showed NRP1 expression (73.3%) and 8 showed NRP2 expression (53.3%). The expression level of NRP1 or NRP2 of neoplasmic tissue was higher than that of extraneoplastic tissues (P < 0.01, Mann-Whitney U test). Fifty-five and 44 NSCLCs expressed NRP1 and NRP2, respectively. Forty patients co-expressing NRP1 and NRP2 showed significantly poorer prognosis and increased vessel counts as compared to those 28 cases without co-expression (P < 0.05, log-rank test; P < 0.05, Mann-Whitney U test). CONCLUSIONS: The co-expression of NRP1 and NRP2 genes is significantly correlated with tumor progression through neovascularization in NSCLC. These results suggest that both NRP1 and NRP2 are key molecules for stromal vascularization by cell-retained VEGF in NSCLC.

Unique properties of 189 amino acid isoform of vascular endothelial growth factor in tumorigenesis.

The 189 amino acid isoform of vascular endothelial growth factor (VEGF189) has been shown to be more strongly associated with the cell membrane than other isoforms of human VEGF (VEGF121, VEGF165). To analyze the biological activities of these VEGF isoforms on tumor growth, we transfected human VEGF121, VEGF165 or VEGF189 cDNA into the human colon cancer cell line SW-480, and established several clones overexpressing these VEGF isoforms. The total amounts of VEGF protein in the culture supernatants of the VEGF189-transfectants were less than those of VEGF121 and VEGF165-transfectants. These transfectants showed no significant differences in growth in culture. Nevertheless, the rate of in vivo tumor growth of VEGF189-transfectants was faster than or equivalent to that of VEGF121-transfectants, while the VEGF165-transfectant showed the greatest enhancement of tumor growth. The protein levels of VEGF were markedly increased only in the VEGF189-transfectants cultured in the presence of heparin. The enhanced in vivo tumor growth of VEGF189-transfectants can be partly explained by the cell-associated features of VEGF189 molecules. The VEGF189 molecule, which is strongly bound to the cell surface, has unique properties and high potential in local angiogenesis and tumor growth in the cancer inductive microenvironment.

Ribozyme mediated cleavage of cell-associated isoform of vascular endothelial growth factor inhibits liver metastasis of a pancreatic cancer cell line.

Stromal angiogenesis is an important factor for progression of malignant neoplasms. We used hammerhead ribozymes against vascular endothelial growth factor (VEGF) gene transcripts to down-regulate cell-associated VEGF189 isoform function in the pancreatic cancer cell line MIA PaCa2. MIA PaCa2 transfected with anti-VEGF189 ribozyme did not show any alteration of growth rate under tissue culture. When the transformants were subcutaneously transplanted, tumour volume of the ribozyme-transfected MIA PaCa2 xenografts was significantly smaller (P<0.01). No metastasis of MIA PaCa2 transfected with anti-VEGF189 was apparent, while disabled ribozyme-transfected MIA PaCa2 showed significant liver metastasis (P<0.05). These results suggested that VEGF189 plays an important role in growth and metastatic potential through alteration of angiogenic balance in cancer.

Angiopoietin-1 and vascular endothelial growth factor expression in human esophageal cancer.

Angiopoietin-1 (Ang-1) has been shown to act as an angiogenic promoter in embryonic angiogenesis by promoting vascular branching, pericyte recruitment and endothelial survival. Ang-1 expression has not been examined in human esophageal cancer. We examined Ang-1 and vascular endothelial growth factor (VEGF) gene expression in tumors from 45 esophageal cancer patients who underwent surgical resection. Forty (88.9%) of the 45 esophageal cancers revealed Ang-1 gene expression. VEGF121, VEGF165 and VEGF189 isoforms were detected in 93.3 (42/45), 55.6 (25/45) and 26.7% (12/45) of the cases, respectively. Ang-1 gene expression was significantly correlated with VEGF121 and VEGF165 gene expression (P=0.0289 and P=0.0127, respectively, Fisher's test). The results suggest that Ang-1 is associated with neovascularization in the cancer stroma through VEGF net-works in esophageal cancer.

Correlation between interleukin 10 and vascular endothelial growth factor expression in human esophageal cancer.

Interleukin 10 (IL-10) is an immunosuppressive cytokine produced by T-lymphocytes, and is a regulatory molecule for angiogenesis in various cancers. We examined IL-10 and vascular endothelial growth factor (VEGF) gene expression in 45 esophageal cancer patients who underwent surgical resection. Thirty-seven (82.2%) of the 45 esophageal cancers revealed IL-10 gene expression. VEGF121, VEGF165 and VEGF189 isoforms were detected in 93.3% (42/45), 55.6% (25/45) and 26.7% (12/45) of cases, respectively. IL-10 gene expression was significantly correlated with VEGF121 gene expression (P=0.0039, Fisher's test). The results suggested that IL-10 stimulates angiogenic factor gene expression.

Pathological significance of vascular endothelial growth factor A isoform expression in human cancer.

Vascular endothelial growth factor (VEGF) is a highly specific factor for vascular endothelial cells. Five VEGF-A isoforms (splice variants 121, 145, 165, 189 and 206) are generated as a result of alternative splicing from a single VEGF-A gene. These differ in their molecular weights and in biological properties such as their ability to bind to cell-surface heparan sulfate proteoglycans. Deregulated VEGF-A expression contributes to the development of solid tumors by promoting tumor angiogenesis. More specifically, VEGF-A189 expression is related to angiogenesis and prognosis in certain human solid tumors. VEGF-A189 expression is also related to the xenotransplantability of human cancers into immunodeficient mice in vivo. Consequently, inhibition of VEGF-A or VEGF-A189 signaling regulates the development and metastasis of a variety of tumors. This review focuses on recent studies of the mechanisms by which VEGF-A regulates angiogenesis in the cancer stroma and on our recent findings concerning the potential mechanisms of VEGF-A189 expression on tumor growth and metastasis.

Ribozyme mediated suppression of vascular endothelial growth factor gene expression enhances matrix metalloproteinase 1 expression in a human hepatocellular carcinoma cell line.

The levels of expression of various genes were altered in cellular transformants with manipulation of expression of single genes. Vascular endothelial growth factor A (VEGF-A) is a key molecule for tumor progression, although it is unclear how VEGF-A expression regulates various genes. Multiple gene expression levels were evaluated using cDNA arrays in a human hepatocellular carcinoma cell line (HLF) with suppression of the VEGF-A gene by anti-VEGF-A ribozyme (alphaVRz). The ribozyme-mediated suppression of VEGF-A gene solely up-regulated matrix metalloproteinase 1 (MMP1) gene level in HLF/alphaVRz. Levels of expression of other members of MMP family or tissue inhibitors of MMPs did not show any alteration. These results suggested that intracellular suppression of VEGF-A gene was specifically linked to up-regulation of MMP1 in human hepatocellular carcinoma cells.

Expression of interleukin-10 is inversely correlated with distant metastasis of renal cell carcinoma.

Interleukin-10 (IL-10) is an immunomodulative cytokine produced by T cells, B cells, and monocytic cells. The significance of IL-10 and IL-10R expression in renal cell carcinoma (RCC) has not been well characterized. In this study, we assessed the correlation between IL-10 gene expression and its pathological significance in 44 RCC specimens. The patients with IL-10 gene expression showed a decreased incidence of metastasis compared to those without IL-10 gene expression. The expression of IL-10 was correlated with vascular endothelial growth factor (VEGF)-A gene expression. These findings suggest that IL-10 gene expression plays some roles in the metastasis of RCC.

Human thrombospondin 2 inhibits proliferation of microvascular endothelial cells.

This study was performed to characterize human thrombospondin 2 (TSP2). TSP2 has recently attracted attention as an endogenous negative regulator of angiogenesis in tumorigenesis. We cloned and transfected human TSP2 cDNA into the human colon cancer cell line SW-480. Stable transfectants (TSP2-1, TSP2-6) overexpressing TSP2 were established. Growth characteristics of TSP2-transfectants were investigated in vitro and in vivo. TSP2-transfectants showed similar growth properties to vector-transfectants and wild-type SW-480 cells. The overexpression of transfected human TSP2 cDNA did not affect proliferation of SW-480 cells. When the conditioned media of TSP2-transfectants were added to cultures of bovine pulmonary microvascular endothelial cells (BPMEC), the BPMEC proliferation was significantly inhibited. These results suggested that human TSP2 is a potential inhibitor of angiogenesis.