124 research outputs found
Study investigating the role of skeletal muscle mass estimation in metastatic spinal cord compression
Background
Age-related loss of functional muscle mass is associated with reduced functional ability and life expectancy. In disseminated cancer, age-related muscle loss may be exacerbated by cachexia and poor nutritional intake, increasing functional decline, morbidity and accelerate death. Patients with spinal metastases frequently present for decompressive surgery with decision to operate based upon functional assessment. A subjective assessment of physical performance has, however, been shown to be a poor indicator of life expectancy in these patients. We aimed to develop an objective measure based upon lean muscle mass to aid decision making, in these individuals, by investigating the association between muscle mass and 1-year survival.
Methods
Muscle mass was calculated as total psoas area (TPA)/ vertebral body area (VBA), by two independent blinded doctors from CT images, acquired within 7 days of spinal metastases surgery, at the mid L3 vertebral level. Outcome at 1 year following surgery was recorded from a prospectively updated metastatic spinal cord compression database.
Results
86 patients were followed for 1 year, with an overall mortality of 39.5 %. Mortality rates at 1 year were significantly high among patients in the lowest quartile of muscle mass, compared with those in the highest quartile (57.1 vs 23.8 %, p = 0.02).
Conclusion
Death within 1 year in individuals with spinal metastases is related to lean muscle mass at presentation. Assessment of lean muscle mass may inform decision to operate in patients with spinal metastases
Quantitation of SPLUNC1 in saliva with an xMAP particle-based antibody capture and detection immunoassay
The short palate lung and nasal epithelial clone 1 (SPLUNC1) protein may be differentially expressed in oral infections, oral inflammatory disorders, or oral malignancies and may be involved in innate immune responses in the oral cavity. However, the actual concentration of SPLUNC1 in saliva has not previously been determined. In this study, we determined the concentrations of SPLUNC1 in saliva using a particle-based antibody capture and detection immunoassay. A commercial goat anti-rhSPLUNC1 polyclonal antibody (AF1897) was linked to fluorescent polystyrene microspheres and used as the capture antibody. A commercial mouse IgG2b anti-rhSPLUNC1 monoclonal antibody (MAB1897) was biotinylated and used as the detection antibody. Western blot and 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) analysis of immunoprecipitated rhSPLUNC1 and SPLUNC1 from saliva were used to show that the capture AF1897 and detection MAB1897 antibodies both recognized SPLUNC1. Protein concentrations in saliva from 20 subjects ranged from 0.9 to 23.9 mg/ml; SPLUNC1 concentrations ranged from 34.7 ng/ml to 13.8 μg/ml; and SPLUNC concentrations normalized per mg of total salivary protein ranged from 4.7 ng/ml to 5.3 μg/ml. These results show that SPLUNC1 is detected in saliva in a variety of concentrations. This immunoassay may prove to be useful in determining the concentration of SPLUNC1 in saliva for assessing its role in the pathogenesis of oral infections, oral inflammatory disorders, or oral malignancies
The Multifunctional Host Defense Peptide SPLUNC1 Is Critical for Homeostasis of the Mammalian Upper Airway
Otitis media (OM) is a highly prevalent pediatric disease caused by normal flora of the nasopharynx that ascend the Eustachian tube and enter the middle ear. As OM is a disease of opportunity, it is critical to gain an increased understanding of immune system components that are operational in the upper airway and aid in prevention of this disease. SPLUNC1 is an antimicrobial host defense peptide that is hypothesized to contribute to the health of the airway both through bactericidal and non-bactericidal mechanisms. We used small interfering RNA (siRNA) technology to knock down expression of the chinchilla ortholog of human SPLUNC1 (cSPLUNC1) to begin to determine the role that this protein played in prevention of OM. We showed that knock down of cSPLUNC1 expression did not impact survival of nontypeable Haemophilus influenzae, a predominant causative agent of OM, in the chinchilla middle ear under the conditions tested. In contrast, expression of cSPLUNC1 was essential for maintenance of middle ear pressure and efficient mucociliary clearance, key defense mechanisms of the tubotympanum. Collectively, our data have provided the first in vivo evidence that cSPLUNC1 functions to maintain homeostasis of the upper airway and, thereby, is critical for protection of the middle ear
The diverse structures and functions of surfactant proteins
Surface tension at liquid–air interfaces is a major barrier that needs to be surmounted by a wide range of organisms; surfactant and interfacially active proteins have evolved for this purpose. Although these proteins are essential for a variety of biological processes, our understanding of how they elicit their function has been limited. However, with the recent determination of high-resolution 3D structures of several examples, we have gained insight into the distinct shapes and mechanisms that have evolved to confer interfacial activity. It is now a matter of harnessing this information, and these systems, for biotechnological purposes
Increased Secreted Amyloid Precursor Protein-α (sAPPα) in Severe Autism: Proposal of a Specific, Anabolic Pathway and Putative Biomarker
Autism is a neurodevelopmental disorder characterized by deficits in verbal communication, social interactions, and the presence of repetitive, stereotyped and compulsive behaviors. Excessive early brain growth is found commonly in some patients and may contribute to disease phenotype. Reports of increased levels of brain-derived neurotrophic factor (BDNF) and other neurotrophic-like factors in autistic neonates suggest that enhanced anabolic activity in CNS mediates this overgrowth effect. We have shown previously that in a subset of patients with severe autism and aggression, plasma levels of the secreted amyloid-β (Aβ) precursor protein-alpha form (sAPPα) were significantly elevated relative to controls and patients with mild-to-moderate autism. Here we further tested the hypothesis that levels of sAPPα and sAPPβ (proteolytic cleavage products of APP by α- and β-secretase, respectively) are deranged in autism and may contribute to an anabolic environment leading to brain overgrowth. We measured plasma levels of sAPPα, sAPPβ, Aβ peptides and BDNF by corresponding ELISA in a well characterized set of subjects. We included for analysis 18 control, 6 mild-to-moderate, and 15 severely autistic patient plasma samples. We have observed that sAPPα levels are increased and BDNF levels decreased in the plasma of patients with severe autism as compared to controls. Further, we show that Aβ1-40, Aβ1-42, and sAPPβ levels are significantly decreased in the plasma of patients with severe autism. These findings do not extend to patients with mild-to-moderate autism, providing a biochemical correlate of phenotypic severity. Taken together, this study provides evidence that sAPPα levels are generally elevated in severe autism and suggests that these patients may have aberrant non-amyloidogenic processing of APP
An innate defense peptide BPIFA1/SPLUNC1 restricts influenza A virus infection
The airway epithelium secretes proteins that function in innate defense against
infection. BPI fold-containing family member A1 (BPIFA1) is secreted into airways
and has a protective role during bacterial infections, but it is not known whether it
also has an antiviral role. To determine a role in host defense against influenza A
virus (IAV) infection and to find the underlying defense mechanism we developed
transgenic mouse models that are deficient in BPIFA1 and used these, in
combination with in vitro 3D mouse tracheal epithelial cell (mTEC) cultures, to
investigate its antiviral properties. We show that BPIFA1 has a significant role in
mucosal defense against IAV infection. BPIFA1 secretion was highly modulated after
IAV infection. Mice deficient in BPIFA1 lost more weight after infection, supported a
higher viral load and virus reached the peripheral lung earlier, indicative of a defect
in the control of infection. Further analysis using mTEC cultures showed that
BPIFA1-deficient cells bound more virus particles, displayed increased nuclear
import of IAV ribonucleoprotein complexes and supported higher levels of viral
replication. Our results identify a critical role for BPIFA1 in the initial phase of
infection by inhibiting the binding and entry of IAV into airway epithelial cells
<span style="font-size:18.5pt;mso-bidi-font-size:13.5pt; font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Immune haemolymph proteins in response to bacterial infection and identification of a putative bacteria binding protein in malaria vector <i><span style="font-size:19.0pt;mso-bidi-font-size:14.0pt;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA">Anopheles stephensi</span></i></span>
558-561Induction of haemolymph
proteins in mosquito A. stephensi due
to wounding or bacterial infection (E.
coli) was analyzed using SDS-PAGE.
Wounding response of pupa revealed subsequent induction of two polypeptides (21
and 74
kDa). Two other polypeptides (44 and 57 kDa)
were induced commonly in both pupa and adult female haemolymph upon bacterial
infection. In vitro binding assay
revealed identification of 44 kDa, a putative bacterial binding protein, a more
relevant protein for further elucidation of molecular mechanism involved in
host parasite interactions.</span
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