Effects of Psidium guajava leaf extract on secretion systems of gram‐negative enteropathogenic bacteria

In this study, 672 plant‐tissue extracts were screened for phytochemicals that inhibit the function of the type III secretion system (T3SS) of enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). Among candidates examined, an extract from the leaves of Psidium guajava (guava) was found to inhibit secretion of EPEC‐secreted protein B (EspB) from EPEC and EHEC without affecting bacterial growth. Guava extract (GE) also inhibited EPEC and EHEC from adhering to, and injecting EspB into, HEp‐2 cells. GE seemed to block translocation of EspB from the bacterial cells to the culture medium. In addition, GE also inhibited the T3SS of Yersinia pseudotuberculosis and Salmonella enterica serovar Typhimurium. After exposure to GE, Y. pseudotuberculosis stopped secreting Yersinia outer proteins and was unable to induce apoptosis of mouse bone marrow‐derived macrophages. S. typhimurium exposed to GE stopped secreting Sip proteins and was unable to invade HEp‐2 cells. GE inhibited secretion of EspC, the type V secretion protein of EPEC, but not secretion of Shiga toxin 2 from EHEC. Thus, our results suggest that guava leaves contain a novel type of antimicrobial compound that could be used to treat and prevent gram‐negative enteropathogenic bacterial infections.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145239/1/mim12604.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145239/2/mim12604_am.pd

Early Bone Marrow Hematopoietic Defect in Simian/Human Immunodeficiency Virus C2/1-Infected Macaques and Relevance to Advance of Disease

To clarify hematological abnormalities following infection with human immunodeficiency virus (HIV), we examined the hematopoietic capability of bone marrow by using cynomolgus monkeys infected with pathogenic simian/human immunodeficiency virus (SHIV) strain C2/1, an animal model of HIV infection. The relationship between the progress of the infection and the CD4/CD8 ratio of T lymphocytes or the amount of SHIV C2/1 viral load in the peripheral blood was also investigated. A colony assay was performed to assess the hematopoietic capability of bone marrow stem cells during the early and advanced phases of the infection. Colonies of granulocytes-macrophages (GM) were examined by PCR for the presence of the SIVmac239 gag region to reveal direct viral infection. There was a remarkable decrease in the CFU-GM growth on days 1 and 3 postinoculation, followed by recovery on day 56. During the more advanced stage, the CFU-GM growth decreased again. There was minimal evidence of direct viral infection of pooled cultured CFU-GM despite the continuously low CD4/CD8 ratios. These results indicate that the decrease in colony formation by bone marrow stem cells is reversible and fluctuates with the advance of the disease. This decrease was not due to direct viral infection of CFU-GM. Our data may support the concept that, in the early phase, production of inhibitory factors or deficiency of a stimulatory cytokine is responsible for some of the bone marrow defects described in the SHIV C2/1 model

F-18-FDG Positron Emission Tomography Findings Correlate Pathological Proliferative Activity of Oral Squamous Cell Carcinoma

Background : It is still controversial whether FDG uptake is correlated with cellular proliferation and prognosis of oral squamous cell carcinoma (OSC). In this study, we performed PET study and immunohistochemical analysis to elucidate the relationship between FDG uptake and expression of cellular proliferative markers and pathological prognostic markers in patients with OSC. Methods : FDG PET and immunohistochemical staining have been carried out in sixteen patients with OSC. Tumor uptake of FDG was expressed with standardized uptake value (SUV). The expression of Ki-67, Topoisomerase IIα (Topo IIα), p53, and p63 in cancer cells was quantitatively assessed with positivity of the immunohistochemical staining. SUV was compared with the results of immunohistochemical analysis. Results : FDG PET study revealed that SUV ranged from 3.6 to 22.1 with average of 10.4. Average positive rate of Ki-67, Topo IIα, p53, and p63 was 68.9%, 58.9%, 72.0%, and 65.2%, respectively. Pearson product-moment correlation coefficient analysis revealed that SUV was significantly correlated with Ki-67 (r=0.616, p=0.01), Topo IIα (r=0.677, p=0.004), p53 (r=0.613, p=0.01), and p63 (r=0.710, p=0.002), respectively. Conclusion : The present preliminary study indicated that FDG uptake was closely correlated with pathological cellular proliferative and prognostic markers in patients with OSC

SEDIMENTOLOGICAL STUDY OF THE SEA BOTTOM SEDIMENTS IN AND AROUND THE ROSS SEA CONTINENTAL SHELF, ANTARCTICA

Sediment cores collected in and around the Ross Sea, Antarctica, are described and discussed based on sedimentological data, such as visual descriptions, sedimentary structures, magnetic susceptibility, sand contents, and water content. On the Ross Sea Continental Shelf, the core sequences contain two lithologic units, soft diatomaceous mud in the upper and compound glacio-marine sediments in the lower. The lower lithologic unit suggests that highly ice-sheet influenced sedimentation existed in glacial times in the Ross Sea. The core sequences on the continental slope and deep-sea basins off the Ross Sea comprise foraminiferal ooze, siliceous mud, and terrigenous mud, sometimes with laminated parts. The laminated parts of the core sequences suggest that strengthened bottom water influenced sedimentation, probably in glacial times. The sedimentary environment in the Late Quaternary is reconstructed based on the core data