'Unlicensed' natural killer cells dominate the response to cytomegalovirus infection.

Natural killer (NK) cells expressing inhibitory receptors that bind to self major histocompatibility complex (MHC) class I are 'licensed', or rendered functionally more responsive to stimulation, whereas 'unlicensed' NK cells lacking receptors for self MHC class I are hyporesponsive. Here we show that contrary to the licensing hypothesis, unlicensed NK cells were the main mediators of NK cell-mediated control of mouse cytomegalovirus infection in vivo. Depletion of unlicensed NK cells impaired control of viral titers, but depletion of licensed NK cells did not. The transfer of unlicensed NK cells was more protective than was the transfer of licensed NK cells. Signaling by the tyrosine phosphatase SHP-1 limited the proliferation of licensed NK cells but not that of unlicensed NK cells during infection. Thus, unlicensed NK cells are critical for protection against viral infection

I. The energies of ionic dissociation of gaseous salt molecules; II. The rate of diffusion of deuterium oxide in water, with a note on the refractive index of deuterium gas

1. An apparatus suitable for separating heavy water from mixtures with organic compounds is described. 2. The refractive index of heavy hydrogen at the wavelength 5461 Å̱ is found to be appreciably smaller than that of ordinary hydrogen and to have the value 1.0001384

The effects of increased freshwater inflow on metal enrichment in selected Eastern Cape estuaries, South Africa

The concentrations of select metals (Cd, Co, Cu, Fe, Pb, Ni and Zn) within the water column and sediment of the permanently open Kariega Estuary and temporary open / closed Riet and East Kleinemonde Estuaries were investigated during a dry and a wet season. Enrichment factors (EFs), using Fe as a reference element, and baseline linear regression models for metals vs Fe were used to assess the extent of metal enrichment in the sediments. The results of the study indicate that Cd, Co Ni and Pb were enriched above baseline concentrations (1.0 < EF < 4.1) in the sediments of all three estuaries. Co, Pb and Ni enrichment in the Kariega Estuary sediments was significantly higher during the dry season, and the mean concentrations of Pb and Cd in the water column were 19-fold and 66-fold higher in the dry season. The elevated concentration of metals during the dry season could be related to accumulation of diffuse pollution from human activities within the catchment area. Conversely, inflow of freshwater into the estuary had the net effect of reducing the concentration and enrichment of these metals within the Kariega Estuary due to scouring and outflow of estuarine water and sediment into the marine environment. The temporal variations in metal concentrations and enrichment factors were less pronounced in the temporary open / closed estuaries than the Kariega Estuary. The observed trend can probably be related to the low anthropogenic impact within the catchment areas of these systems, and the relatively smaller size of the catchments. Significant spatial variations existed in metal enrichment in the sediment of both the East Kleinemonde and Riet Estuaries, with the highest degrees of enrichment occurring in the sediments from the marine environment and lower reaches

Sec17 Can Trigger Fusion of Trans-SNARE Paired Membranes without Sec18

Sec17 [soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein; α-SNAP] and Sec18 (NSF) perform ATP-dependent disassembly of cis-SNARE complexes, liberating SNAREs for subsequent assembly of trans-complexes for fusion. A mutant of Sec17, with limited ability to stimulate Sec18, still strongly enhanced fusion when ample Sec18 was supplied, suggesting that Sec17 has additional functions. We used fusion reactions where the four SNAREs were initially separate, thus requiring no disassembly by Sec18. With proteoliposomes bearing asymmetrically disposed SNAREs, tethering and trans-SNARE pairing allowed slow fusion. Addition of Sec17 did not affect the levels of trans-SNARE complex but triggered sudden fusion of trans-SNARE paired proteoliposomes. Sec18 did not substitute for Sec17 in triggering fusion, but ADP- or ATPγS-bound Sec18 enhanced this Sec17 function. The extent of the Sec17 effect varied with the lipid headgroup and fatty acyl composition of the proteoliposomes. Two mutants further distinguished the two Sec17 functions: Sec17(L291A,L292A) did not stimulate Sec18 to disassemble cis-SNARE complex but triggered the fusion of trans-SNARE paired membranes. Sec17(F21S,M22S), with diminished apolar character to its hydrophobic loop, fully supported Sec18-mediated SNARE complex disassembly but had lost the capacity to stimulate the fusion of trans-SNARE paired membranes. To model the interactions of SNARE-bound Sec17 with membranes, we show that Sec17, but not Sec17(F21S,M22S), interacted synergistically with the soluble SNARE domains to enable their stable association with liposomes. We propose a model in which Sec17 binds to trans-SNARE complexes, oligomerizes, and inserts apolar loops into the apposed membranes, locally disturbing the lipid bilayer and thereby lowering the energy barrier for fusion

Fishery Resource of the Upper Mississippi River and Relationship to Stream Discharge

ABSTRACT-Fish population data collected through the Northern States Power Company monitoring program near its plants at Monticello and Becker, Minnesota were analyzed to describe species diversity, changes in recreational fishing, fishing success, and the influence of stream discharge on smallmouth bass year-class success and abundance. The work is part of a more extensive effort to develop a model applicable in managing the upper Mississippi River to meet the growing needs of recreation, agriculture, communities, and industry. Analysis of these data shows 48 species to be present and that smallmouth bass, Micropterus dolomieu~ is the most important game species in the growing recreational fishery. Comparison of smallmouth bass year-class strength estimates with stream discharge for the period 1973-1987, indicates strong year-classes develop during years characterized by low spring and summer discharge

Characterization of thromboxane A2 receptor and TRPV1 mRNA expression in cultured sensory neurons

Thromboxane A2 (TxA2) is an arachidonic acid metabolite that stimulates platelet aggregation and vasoconstriction when released from platelets and other cell types during tissue trauma. More recent research has demonstrated that TxA2 can also stimulate vagal and spinal sensory nerves. The purpose of this study was twofold. One, we compared the expression of the TxA2 receptor (TxA2R) in neurons from two sensory ganglia: the nodose ganglion (NG) containing cell bodies of vagal afferent nerves and the thoracic dorsal root ganglion (DRG) containing cell bodies of spinal afferent nerves. Two, we determined if TxA2R co-localizes with mRNA for the nociceptive marker, TRPV1, which is the receptor for the noxious substance capsaicin. We found a greater percentage of neurons in the NG that are positive for TxA2R expression than in the DRG. We also found that there was no correlation of expression of TxA2R with TRPV1. These data suggest that while TxA2R is expressed in both vagal and spinal neurons, TxA2 may elicit stronger vagal or parasympathetic reflexes in the rabbit when released during tissue trauma depending on the location of release. Our data also indicate that TxA2 is likely to stimulate both nociceptive and non-nociceptive neurons thereby broadening the types of neurons and reflexes that it may excite

Predictive Screening of M1 and M2 Macrophages Reveals the Immunomodulatory Effectiveness of Post Spinal Cord Injury Azithromycin Treatment

Spinal cord injury (SCI) triggers a heterogeneous macrophage response that when experimentally polarized toward alternative forms of activation (M2 macrophages) promotes tissue and functional recovery. There are limited pharmacological therapies that can drive this reparative inflammatory state. In the current study, we used in vitrosystems to comprehensively defined markers of macrophages with known pathological (M1) and reparative (M2) properties in SCI. We then used these markers to objectively define the macrophage activation states after SCI in response to delayed azithromycin treatment. Mice were subjected to moderate-severe thoracic contusion SCI. Azithromycin or vehicle was administered beginning 30 minutes post-SCI and then daily for 3 or 7 days post injury (dpi). We detected a dose-dependent polarization toward purportedly protective M2 macrophages with daily AZM treatment. Specifically, AZM doses of 10, 40, or 160 mg/kg decreased M1 macrophage gene expression at 3 dpi while the lowest (10 mg/kg) and highest (160 mg/kg) doses increased M2 macrophage gene expression at 7 dpi. Azithromycin has documented immunomodulatory properties and is commonly prescribed to treat infections in SCI individuals. This work demonstrates the utility of objective, comprehensive macrophage gene profiling for evaluating immunomodulatory SCI therapies and highlights azithromycin as a promising agent for SCI treatment

Azithromycin Drives Alternative Macrophage Activation and Improves Recovery and Tissue Sparing in Contusion Spinal Cord Injury

BACKGROUND: Macrophages persist indefinitely at sites of spinal cord injury (SCI) and contribute to both pathological and reparative processes. While the alternative, anti-inflammatory (M2) phenotype is believed to promote cell protection, regeneration, and plasticity, pro-inflammatory (M1) macrophages persist after SCI and contribute to protracted cell and tissue loss. Thus, identifying non-invasive, clinically viable, pharmacological therapies for altering macrophage phenotype is a challenging, yet promising, approach for treating SCI. Azithromycin (AZM), a commonly used macrolide antibiotic, drives anti-inflammatory macrophage activation in rodent models of inflammation and in humans with cystic fibrosis. METHODS: We hypothesized that AZM treatment can alter the macrophage response to SCI and reduce progressive tissue pathology. To test this hypothesis, mice (C57BL/6J, 3-month-old) received daily doses of AZM (160 mg/kg) or vehicle treatment via oral gavage for 3 days prior and up to 7 days after a moderate-severe thoracic contusion SCI (75-kdyn force injury). Fluorescent-activated cell sorting was used in combination with real-time PCR (rtPCR) to evaluate the disposition and activation status of microglia, monocytes, and neutrophils, as well as macrophage phenotype in response to AZM treatment. An open-field locomotor rating scale (Basso Mouse Scale) and gridwalk task were used to determine the effects of AZM treatment on SCI recovery. Bone marrow-derived macrophages (BMDMs) were used to determine the effect of AZM treatment on macrophage phenotype in vitro. RESULTS: In accordance with our hypothesis, SCI mice exhibited significantly increased anti-inflammatory and decreased pro-inflammatory macrophage activation in response to AZM treatment. In addition, AZM treatment led to improved tissue sparing and recovery of gross and coordinated locomotor function. Furthermore, AZM treatment altered macrophage phenotype in vitro and lowered the neurotoxic potential of pro-inflammatory, M1 macrophages. CONCLUSIONS: Taken together, these data suggest that pharmacologically intervening with AZM can alter SCI macrophage polarization toward a beneficial phenotype that, in turn, may potentially limit secondary injury processes. Given that pro-inflammatory macrophage activation is a hallmark of many neurological pathologies and that AZM is non-invasive and clinically viable, these data highlight a novel approach for treating SCI and other maladaptive neuroinflammatory conditions

Modulation of Sleep Quality and Autonomic Functioning by Symptoms of Depression in Women with Irritable Bowel Syndrome

The objective of this study was to determine how depressive symptoms affect autonomic activity during sleep, objective and subjective sleep, and gastrointestinal symptom severity in women with irritable bowel syndrome (IBS). Seventy women who met the Rome II criteria for IBS and 21 healthy volunteers participated. All participants were recruited from the surrounding community. IBS patients were stratified into two groups based on their Beck Depression Inventory II score and 44 IBS patients with depressive symptoms (IBS+DS) were compared to 26 IBS patients without depressive symptoms (IBS−DS). Autonomic activity was measured by heart rate variability (HRV) analysis. Fifteen-minute segments were selected from a baseline presleep period, stage 2, slow-wave sleep, and rapid-eye movement sleep for heart rate variability spectral analysis. Subjective sleep quality was assessed by the Pittsburg Sleep Quality Index (PSQI) and gastrointestinal symptom severity was assessed by an 18-item questionnaire. The IBS+DS group reported significantly ( P <0.01) more sleep complaints, measured by the PSQI, than the IBS−DS group and healthy controls. The IBS+DS group took significantly ( P <0.05) longer to enter their first rapid-eye movement period than healthy controls. The IBS+DS group reported significantly ( P =0.01) increased gastrointestinal symptom severity compared to the IBS−DS group. There were no significant group differences in autonomic activity during the baseline presleep period or sleep stages. The results demonstrated that IBS patients with significant depressive symptoms had increased gastrointestinal symptom severity, increased sleep complaints, and alterations in sleep architecture compared to healthy controls and IBS patients without significant depressive symptoms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44433/1/10620_2004_Article_494230.pd