(-)-Epigallocatechin gallate, the most active polyphenolic catechin in green tea, presynaptically facilitates Ca2+-dependent glutamate release via activation of protein kinase C in rat cerebral cortex

(-)-Epigallocatechin gallate (EGCG), the main polyphenolic constituent of green tea, has been reported to improve cognitive decline. Considering the central glutamatergic activity is crucial to cognitive function, the objective of this study was to investigate the effect of EGCG on the release of endogenous glutamate using nerve terminals purified from rat cerebral cortex. Results showed that the release of glutamate evoked by 4-aminopyridine (4AP) was facilitated by EGCG in a concentration-dependent manner, and this effect resulted from an enhancement of vesicular exocytosis and not from an increase in Ca2+-independent efflux via glutamate transporter. Examination of the effect of EGCG on cytoplasmic free Ca2+ concentration ([Ca2+]c) revealed that the facilitation of glutamate release could be attributed to an increase in Ca2+ influx through N- and P/Q-type voltage-dependent Ca2+ channels. Consistent with this, the EGCG-mediated facilitation of 4AP-evoked glutamate release was significantly prevented in synaptosomes pretreated with a combination of the N- and P/Q-type Ca2+ channel blockers. Additionally, inhibition of protein kinase C (PKC) by treatment with Ro318220 significantly reduced the facilitatory effect of EGCG on 4AP-evoked glutamate release and phosphorylation of PKC or its presynaptic target myristoylated alanine-rich C kinase substrate (MARCKS). These results suggest that EGCG effects a facilitation of glutamate release from glutamatergic terminals by positively modulating N- and P/Q-type Ca2+ channel activation through a signaling cascade involving PKC. In this EGCG/PKC signaling cascade facilitating glutamate release, the regulation of cytoskeleton dynamics was also indicated to be involved by disruption of cytoskeleton organization with cytochalasin D occluded the EGCG-mediated facilitation of 4AP-evoked glutamate release.     

Mechanical injuries to the ipsilateral non-diseased lobes(s) during pulmonary resection--another factor causing postoperative complications

BACKGROUND: The occurrence of complications after major pulmonary resection is known to be related to various factors. However, peri-surgical injuries to the ipsilateral non-diseased lobes(s) occurring during resection have never been mentioned in the literature. This study aimed to verify the injury in cases after lobectomy and wedge resection. METHODS: Data from eighteen patients who underwent lobectomy or wedge resection for malignant tumor between January 2003 and January 2004 were collected. All patients had pre- and postoperative examinations of alveolar-capillary membrane (A/C) permeability using 99m TC-DPTA radioaerosol. RESULTS: Ten lobectomies and eight wedge resection were performed. Using the paired t-test with each patient's pre-operative A/C permeability as his own control data, the postoperative A/C permeability of the ipsilateral non-diseased lobe(s) was found to be significantly increased. The degree of increase in the lobectomy group was the same as that in the wedge resection group. However, no significant change was found on the contralateral side in both groups. CONCLUSION: The degree of increase of permeability was the same in both groups, indicating that the effects of stretch on the surviving lung are not a contributing factor to the change in A/C permeability. The mechanical injuries during the pulmonary surgical procedure alter the permeability, which could be a possible factor causing postoperative pulmonary complications.     

Functional nanofiber scaffolds with different spacers modulate adhesion and expansion of cryopreserved umbilical cord blood hematopoietic stem/progenitor cells

OBJECTIVE: Nanofiber scaffolds with amino groups conjugated to fiber surface through different spacers (ethylene, butylenes, and hexylene groups, respectively) were prepared and the effect of spacer length on adhesion and expansion of umbilical cord blood hematopoietic stem/ progenitor cells (HSPCs) was investigated. MATERIALS AND METHODS: Electrospun polymer nanofiber scaffolds were functionalized with poly(acrylic acid) grafting, followed by conjugation of amino groups with different spacers. HSPCs were expanded on aminated scaffolds for 10 days. Cell proliferation, surface marker expression, clonogenic potential, and nonobese diabetic (NOD)/severe combined immunodeficient (SCID) repopulation potential of the expanded cells were evaluated following expansion culture. RESULTS: Aminated nanofiber scaffolds with ethylene and butylene spacers showed high-expansion efficiencies (773- and 805-fold expansion of total cells, 200- and 235-fold expansion of CD34+CD45' cells, respectively). HSPC proliferation on aminated scaffold with hexylene spacer was significantly lower (210-fold expansion of total cells and 86-fold expansion of CD34+CD45+ cells), but maintained the highest CD34+CD45+ cell fraction (41.1%). Colony-forming unit granulocyte-erythrocyte-monocyte-megakaryocyte and long-term culture-initiating cell maintenance was similar for HSPCs expanded on all three aminated nanofiber scaffolds; nevertheless, the NOD/SCID mice engraftment potential of HSPCs expanded on aminoethyl and aminobutyl conjugated nanofibers was significantly higher than that on aminohexyl conjugated nanofibers. CONCLUSION: This study demonstrated that aminated nanofibers are superior substrates for ex vivo HSPC expansion, which was correlated with the enhanced HSPC adhesion to these aminated nanofibers. The spacer, through which amino groups were conjugated to nanofiber surface, affected the expansion outcome. Our results highlighted the importance of scaffold topography and cell-substrate interaction to regulating HSPC proliferation and self-renewal in cytokine-supplemented expansion.     

Diagnosis of peripheral lung cancer with three echoic features via endobronchial ultrasound

BACKGROUND: Endobronchial ultrasonography (EBUS) is useful in localizing peripheral lung lesions. Previous reports have revealed that several characteristic echoic patterns correlate well with the histopathologic findings of benign and malignant lesions. Therefore, EBUS may be also useful in the differential diagnosis of malignant lesions of the lung. OBJECTIVE: To assess the feasibility of EBUS in the differential diagnosis between malignant and benign lesions by the following three characteristic echoic features indicating malignancy: continuous margin; absence of a linear-discrete air bronchogram; and heterogeneous echogenicity. METHOD: EBUS images from 224 patients who undergone bronchoscopy for a peripheral lung lesion were analyzed. The sensitivity and specificity for each echoic feature or in combination in diagnosing malignancy or benignity were determined. RESULT: Continuous margin, absence of linear-discrete air bronchogram, and heterogeneous echogenicity are three echoic features indicating malignancy. The absence of linear-discrete air bronchogram has the highest sensitivity in the diagnosis of malignancy (91.9%), but the lowest specificity (62.4%). By contrast, a well-defined margin has the highest specificity (93.1%), but the lowest sensitivity (27.6%). The sensitivity and specificity for heterogeneous echogenicity are intermediate (65.0% and 90.1%, respectively). The negative predictive value for the malignancy of a lesion with none of these three echoic features is 93.7%. The positive predictive value for malignancy of a lesion with any two of the three echoic features is 89.2%. CONCLUSION: These results indicate that EBUS is useful as an adjunct in lung cancer diagnosis, especially when peripheral lung lesions are not visible in traditional bronchoscopy.     

Cytomegalovirus UL97 kinase mutations that confer maribavir resistance

The cytomegalovirus (CMV) UL97 kinase inhibitor maribavir (MBV) is undergoing clinical antiviral trials. Two clinical CMV isolates serially passaged in cell culture under MBV showed >20-fold increases in MBV resistance after the development of the UL97 mutation V353A in one of the isolates and of T409M in the other. Marker transfer studies confirmed that the V353A and T409M mutations conferred ~15-fold and ~80-fold increases, respectively, in MBV resistance without significantly affecting ganciclovir susceptibility. The 3 UL97 mutations now known to confer MBV resistance are located upstream of UL97 mutations linked to ganciclovir resistance, closer to kinase domains that are associated with adenosine triphosphate binding and phosphotransfer.     

Lupus erythematosus (LE) cells in ascites: initial diagnosis of systemic lupus erythematosus by cytological examination: a case report

Systemic lupus erythematosus (SLE) is an autoimmune disease, involving multiple organs. Diverse manifestations may obscure the diagnosis and confuse our thinking process, especially when few clues are present at the beginning. Serositis is one of the various presentations, and the presence of lupus erythematosus (LE) cell in body fluid may be a hint for the final diagnosis of SLE. Herein, we present a young female patient diagnosed of SLE with initial presentation of lupus peritonitis. Finding of LE cell in ascites prompted us for immunologic survey. Diagnosis of SLE was confirmed with high titer of anti-nuclear antibody and antibody to double-stranded DNA. Cytologic examination of body fluid is mainly useful in detecting malignant cells, but high specificity of this marker aids in early diagnosis of SLE.