164 research outputs found
Focusing and imaging with increased numerical apertures through multimode fibers with micro-fabricated optics
The use of individual multimode optical fibers in endoscopy applications has
the potential to provide highly miniaturized and noninvasive probes for
microscopy and optical micromanipulation. A few different strategies have been
proposed recently, but they all suffer from intrinsically low resolution
related to the low numerical aperture of multimode fibers. Here, we show that
two-photon polymerization allows for direct fabrication of micro-optics
components on the fiber end, resulting in an increase of the numerical aperture
to a value that is close to 1. Coupling light into the fiber through a spatial
light modulator, we were able to optically scan a submicrometer spot (300 nm
FWHM) over an extended region, facing the opposite fiber end. Fluorescence
imaging with improved resolution is also demonstrated.Comment: 5 pages, 3 figure
Ethnobotany, Phytochemistry and Pharmacology of \u3cem\u3eMussaenda\u3c/em\u3e Species (Rubiaceae)
The genus Mussaenda is an important source of medicinal natural products, particularly iridoids, triterpenes and flavonoids. The purpose of this paper is to cover the more recent developments in the ethnobotany, pharmacology and phytochemistry of this genus. The species in which the largest number of compounds has been identified is Mussaenda pubescens. Pharmacological studies have also been made, however, of other species in this genus. These lesser known plants of the genus are described here according to their cytotoxicity, anti-inflammatory, antiviral, antioxidant and antibacterial properties. The information given here is intended to serve as a reference tool for practitioners in the fields of ethnopharmacology and natural products chemistry
Helminth Infections Coincident with Active Pulmonary Tuberculosis Inhibit Mono- and Multifunctional CD4+ and CD8+ T Cell Responses in a Process Dependent on IL-10
Tissue invasive helminth infections and tuberculosis (TB) are co-endemic in many parts of the world and can trigger immune responses that might antagonize each other. We have previously shown that helminth infections modulate the Th1 and Th17 responses to mycobacterial-antigens in latent TB. To determine whether helminth infections modulate antigen-specific and non-specific immune responses in active pulmonary TB, we examined CD4(+) and CD8(+) T cell responses as well as the systemic (plasma) cytokine levels in individuals with pulmonary TB with or without two distinct helminth infections-Wuchereria bancrofti and Strongyloides stercoralis infection. By analyzing the frequencies of Th1 and Th17 CD4(+) and CD8(+) T cells and their component subsets (including multifunctional cells), we report a significant diminution in the mycobacterial-specific frequencies of mono- and multi-functional CD4(+) Th1 and (to a lesser extent) Th17 cells when concomitant filarial or Strongyloides infection occurs. The impairment in CD4(+) and CD8(+) T cell cytokine responses was antigen-specific as polyclonal activated T cell frequencies were equivalent irrespective of helminth infection status. This diminution in T cell responses was also reflected in diminished circulating levels of Th1 (IFN-γ, TNF-α and IL-2)- and Th17 (IL-17A and IL-17F)-associated cytokines. Finally, we demonstrate that for the filarial co-infections at least, this diminished frequency of multifunctional CD4(+) T cell responses was partially dependent on IL-10 as IL-10 blockade significantly increased the frequencies of CD4(+) Th1 cells. Thus, co-existent helminth infection is associated with an IL-10 mediated (for filarial infection) profound inhibition of antigen-specific CD4(+) T cell responses as well as protective systemic cytokine responses in active pulmonary TB
Dynamic alterations in monocyte numbers, subset frequencies and activation markers in acute and convalescent COVID-19 individuals
Monocytes are thought to play an important role in host defence and pathogenesis of COVID-19. However, a comprehensive examination of monocyte numbers and function has not been performed longitudinally in acute and convalescent COVID-19. We examined the absolute counts of monocytes, the frequency of monocyte subsets, the plasma levels of monocyte activation markers using flowcytometry and ELISA in seven groups of COVID-19 individuals, classified based on days since RT-PCR confirmation of SARS-CoV2 infection. Our data shows that the absolute counts of total monocytes and the frequencies of intermediate and non-classical monocytes increases from Days 15–30 to Days 61–90 and plateau thereafter. In contrast, the frequency of classical monocytes decreases from Days 15–30 till Days 121–150. The plasma levels of sCD14, CRP, sCD163 and sTissue Factor (sTF)—all decrease from Days 15–30 till Days 151–180. COVID-19 patients with severe disease exhibit higher levels of monocyte counts and higher frequencies of classical monocytes and lower frequencies of intermediate and non-classical monocytes and elevated plasma levels of sCD14, CRP, sCD163 and sTF in comparison with mild disease. Thus, our study provides evidence of dynamic alterations in monocyte counts, subset frequencies and activation status in acute and convalescent COVID-19 individuals
Recovery of Memory B-cell Subsets and Persistence of Antibodies in Convalescent COVID-19 Patients
Inhibition of Intestinal Adenoma Formation in APCMin/+ Mice by Riccardin D, a Natural Product Derived from Liverwort Plant Dumortiera hirsuta
BACKGROUND: Mutation of tumor suppressor gene, adenomatous polyposis coli (APC), is the primary molecular event in the development of most intestinal carcinomas. Animal model with APC gene mutation is an effective tool for study of preventive approaches against intestinal carcinomas. We aimed to evaluate the effect of Riccardin D, a macrocyclic bisbibenzyl compound, as a chemopreventive agent against intestinal adenoma formation in APC(Min/+) mice. METHODS: APC(Min/+) mice were given Riccardin D by p.o. gavage for 7 weeks. Mice were sacrificed, and the number, size and histopathology of intestinal polyps were examined under a microscope. We performed immunohistochemical staining, western blotting, reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) in intestinal polyps to investigate the mechanism of chemopreventive effect of Riccardin D. RESULTS: Riccardin D treatment resulted in a significant inhibition of intestinal adenoma formation, showing a reduction of polyp number by 41.7%, 31.1% and 44.4%, respectively, in proximal, middle and distal portions of small intestine. The activity of Riccardin D against polyp formation was more profound in colon, wherein Riccardin D decreased polyp number by 79.3%. Size distribution analysis revealed a significant reduction in large-size polyps (2-3 mm) by 40.0%, 42.5% and 33.3%, respectively, in proximal, middle and distal portions of small intestine, and 77.8% in colon. Histopathological analysis of the intestinal polyps revealed mostly hyperplastic morphology without obvious dysplasia in Riccardin D-treated mice. Molecular analyses of the polyps suggested that the inhibitory effect of Riccardin D on intestinal adenoma formation was associated with its abilities of reduction in cell proliferation, induction of apoptosis, antiangiogenesis, inhibition of the Wnt signaling pathway and suppression of inflammatory mediators in polyps. CONCLUSIONS: Our results suggested that Riccardin D exerts its chemopreventive effect against intestinal adenoma formation through multiple mechanisms including anti-proliferative, apoptotic, anti-angiogenic and anti-inflammatory activity
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