Ultrastructural localization of extracellular matrix proteins of the lymph node cortex: evidence supporting the reticular network as a pathway for lymphocyte migration

<p>Abstract</p> <p>Background</p> <p>The lymph node (LN) is a crossroads of blood and lymphatic vessels allowing circulating lymphocytes to efficiently recognize foreign molecules displayed on antigen presenting cells. Increasing evidence indicates that after crossing high endothelial venules, lymphocytes migrate within the node along the reticular network (RN), a scaffold of fibers enwrapped by fibroblastic reticular cells (FRC). Light microscopy has shown that the RN contains specific extracellular matrix (ECM) proteins, which are putative molecular "footholds" for migration, and are known ligands for lymphocyte integrin adhesion receptors.</p> <p>Results</p> <p>To investigate whether ECM proteins of the RN are present on the outer surface of the FRC and are thus accessible to migrating lymphocytes, ultrastructural immunohistochemical staining of cynomolgus monkey LN was performed using antibodies to human ECM proteins that were successfully employed at the light microscopic level. The fibrillar collagens I and III were observed primarily within the reticular network fibers themselves. In contrast, the matrix proteins laminin, fibronectin, collagen IV, and tenascin were observed within the reticular fibers and also on the outer membrane surface of the FRC.</p> <p>Conclusions</p> <p>These findings suggest a molecular basis for how the RN functions as a pathway for lymphocyte migration within the lymph node.</p

African volcanic emissions influencing atmospheric aerosols over the Amazon rain forest

The long-range transport (LRT) of trace gases and aerosol particles plays an important role for the composition of the Amazonian rain forest atmosphere. Sulfate aerosols originate to a substantial extent from LRT sources and play an important role in the Amazonian atmosphere as strongly light-scattering particles and effective cloud condensation nuclei. The transatlantic transport of volcanic sulfur emissions from Africa has been considered as a source of particulate sulfate in the Amazon; however, direct observations have been lacking so far. This study provides observational evidence for the influence of emissions from the Nyamuragira–Nyiragongo volcanoes in Africa on Amazonian aerosol properties and atmospheric composition during September 2014. Comprehensive ground-based and airborne aerosol measurements together with satellite observations are used to investigate the volcanic event. Under the volcanic influence, hourly mean sulfate mass concentrations in the submicron size range reached up to 3.6&thinsp;µg&thinsp;m−3 at the Amazon Tall Tower Observatory, the highest value ever reported in the Amazon region. The substantial sulfate injection increased the aerosol hygroscopicity with κ values up to 0.36, thus altering aerosol–cloud interactions over the rain forest. Airborne measurements and satellite data indicate that the transatlantic transport of volcanogenic aerosols occurred in two major volcanic plumes with a sulfate-enhanced layer between 4 and 5&thinsp;km of altitude. This study demonstrates how African aerosol sources, such as volcanic sulfur emissions, can substantially affect the aerosol cycling and atmospheric processes in Amazonia.</p

The chrondoprotective actions of a natural product are associated with the activation of IGF-1 production by human chondrocytes despite the presence of IL-1β

BACKGROUND: Cartilage loss is a hallmark of arthritis and follows activation of catabolic processes concomitant with a disruption of anabolic pathways like insulin-like growth factor 1 (IGF-1). We hypothesized that two natural products of South American origin, would limit cartilage degradation by respectively suppressing catabolism and activating local IGF-1 anabolic pathways. One extract, derived from cat's claw (Uncaria guianensis, vincaria(®)), is a well-described inhibitor of NF-κB. The other extract, derived from the vegetable Lepidium meyenii (RNI 249), possessed an uncertain mechanism of action but with defined ethnomedical applications for fertility and vitality. METHODS: Human cartilage samples were procured from surgical specimens with consent, and were evaluated either as explants or as primary chondrocytes prepared after enzymatic digestion of cartilage matrix. Assessments included IGF-1 gene expression, IGF-1 production (ELISA), cartilage matrix degradation and nitric oxide (NO) production, under basal conditions and in the presence of IL-1β. RESULTS: RNI 249 enhanced basal IGF-1 mRNA levels in human chondrocytes by 2.7 fold, an effect that was further enhanced to 3.8 fold by co-administration with vincaria. Enhanced basal IGF-1 production by RNI 249 alone and together with vincaria, was confirmed in both explants and in primary chondrocytes (P <0.05). As expected, IL-1β exposure completely silenced IGF-1 production by chondrocytes. However, in the presence of IL-1β both RNI 249 and vincaria protected IGF-1 production in an additive manner (P <0.01) with the combination restoring chondrocyte IGF-1 production to normal levels. Cartilage NO production was dramatically enhanced by IL-1β. Both vincaria and RNI 249 partially attenuated NO production in an additive manner (p < 0.05). IL-1β – induced degradation of cartilage matrix was quantified as glycosaminoglycan release. Individually RNI 249 or vincaria, prevented this catabolic action of IL-1β. CONCLUSION: The identification of agents that activate the autocrine production of IGF-1 in cartilage, even in the face of suppressive pro-inflammatory, catabolic cytokines like IL-1β, represents a novel therapeutic approach to cartilage biology. Chondroprotection associated with prevention of the catabolic events and the potential for sustained anabolic activity with this natural product suggests that it holds significant promise in the treatment of debilitating joint diseases

An inquiry into the distributional differences of Streptopus amplexifolius and S. roseus.

http://deepblue.lib.umich.edu/bitstream/2027.42/53204/1/1638.pdfDescription of 1638.pdf : Access restricted to on-site users at the U-M Biological Station

Walter Bobrowski Diary, 1944-1946

To access archived versions of content referenced in the diary transcript, download 'Bobrowski-Diary_Resources.zip' and extract contents with an appropriate utility. Then open the 'index.html' file in a web browser.Native of Detroit, Mich., born on June 27, 1924 and graduated from Chadsey High School in 1942. Apprenticed at Solvay Process Chemical Co. repair shop and worked as lathe hand at Timken Detroit Axle Co. before induction in the United States Navy. Served in the Pacific theater aboard LCT (6) 1411, with first action on the western beaches of Okinawa in April, 1945. Continued service in Okinawa after the unconditional surrender of Japan, earning rank of Motor Machinist Mate 3rd class. Returned to the United States aboard the U.S.S. Ticonderoga. Discharged on January 30, 1946 and was a member of VFW Post 6896. Died January 6, 2012. Collection includes a transcript of Bobrowski's World War II service diary from induction to discharge, including participation in the invasion of Okinawa in 1945. Provides details of combat operations, shipping of material, Japanese kamikaze attacks, and the daily life of sailors, with references to films (The Big Sleep) and musicians (Duke Ellington). Also notes the bombing of Hiroshima, Russian declaration of war on Japan, and V-J Day. Collection also contains two photographs of Bobrowski in uniform and archived versions of online resources referred to in diary transcript.http://deepblue.lib.umich.edu/bitstream/2027.42/102027/1/Bobrowski_WWII-Diary.docxhttp://deepblue.lib.umich.edu/bitstream/2027.42/102027/2/Bobrowski-Diary_Resources.ziphttp://deepblue.lib.umich.edu/bitstream/2027.42/102027/3/Bobrowski_Navy-whites.JPGhttp://deepblue.lib.umich.edu/bitstream/2027.42/102027/4/Bobrowslo_Navy-blues.JP

Preliminary results of biomonitoring survey at Virunga Volcanic Province (D.R. Congo), Eastern Africa.

Biomonitoring techniques have been widely used in environmental studies to monitor anthropogenic pollutants. Recently such techniques have been also applied to ascertain the impact of contaminants naturally released by volcanic activity (Calabrese et al., 2015; Arndt et al., 2017). In the present study a biomonitoring survey has been performed in different sites around Nyiragongo and Nyamulagira (D.R. Congo), active volcanoes in the western branch of the East African Rift. We applied both active and passive biomonitoring techniques in order to investigate the release of some harmful chemical elements by Nyiragongo and Nyamulagira: the former was performed by exposing moss-bags (Sphagnum sp.) as active accumulators of volcanic gases and particles. At the same time, additional samples were collected from Amaranthus viridis and Senecio sp. leaves, as well as liquid samples from squeezed banana tree (Musa paradisiaca and Musa nana). Both Amaranthus viridis and banana are plants widespread in the study area and locally edible. While Amaranthus viridis is solely used as vegetable, banana is starchy and additionally used for juice and wine production. The liquid from squeezed banana tree is further used for cooking and drinking in some localities around Nyiragongo and Nyamulagira during the dry season. Any presence of volcanogenic harmful elements in these plants would lead to potential health risk for the population living around these volcanoes. These plants can thus be used to assess the environmental impact and the human health hazard associated with Nyiragongo and Nyamulagira volcanic emissions. All leave samples were gently isolated, dried and powdered avoiding metal contamination for acid microwave extraction (HNO3 + H2O2). Solutions were analyzed for major and trace elements by inductively coupled plasma spectrometry (ICP-MS and ICP-OES) for 49 elements. Preliminary results show a clear fingerprint of volcanic emissions both in the exposed moss bags and in the collected plants. Several elements (Al, As, Ba, Bi, Fe, Mo, Sb, Se, Sr, Te, Tl, Pb) are strongly enriched in the mosses exposed to the volcanic emissions with the highest enrichment measured close to the summit crater. However, evidences of metal bioaccumulation are also found in downwind sites (e.g. Kingi village, at several km from the volcanic source). Leaves of the studied plants also reflect the geographical dispersion of the volcanic plume, especially for highly volatile elements in high temperature volcanic environments such as Tl, Te, Bi, Se, Cu, As, Cd, S. Also alkali metals showed a significant increase in their concentrations, probably because of their affinity for the halide species which are often carried by particles (ashes, pele’s hair and tears, lithics) produced by the spattering and fracturing at the lava lake surface. The liquid water from banana samples has high concentrations of nutrients (Na, K, Mg, Ca, Cl) and trace metals (B, Ba, Cs, Rb, Zn, Tl). The preliminary results clearly highlighted a potential hazard for the population that live close to the Nyiragongo and Nyamulagira volcanoes. Calabrese et al., 2015, Chemosphere, 119, 1447-1455 Arndt et al., 2017, JVGR, 343, 220-23

Annex 2 to: Passive Degassing at Nyiragongo (D.R. Congo) and Etna (Italy) Volcanoes.

Plumes [...

Annex 1 to: Passive Degassing at Nyiragongo (D.R. Congo) and Etna (Italy) Volcanoes.

Volcanic EmissionsThe technique for the assessment of the metal output from volcanoes was based on direct (in- plume) collection of the plume on filter substrates. Gas and aerosols in the volcanic plume have been sampled from the rims of the active craters. [...