Proximal Fluid Research Articles

Preoperative protein profiles in cerebrospinal fluid in elderly hip fracture patients at risk for delirium: A proteomics and validation study

BackgroundA neuroinflammatory response is suggested to play an important role in delirium, a common complication in older hospitalized patients. We examined whether hip fracture patients who develop postoperative delirium have a different proteome in cerebrospinal fluid (CSF) prior to surgery. MethodsPatients (≥75years) were admitted for hip fracture surgery. CSF was collected during spinal anaesthesia; proteins were separated using gel electrophoresis and identified with mass spectrometry. We compared the proteome of patients with and without postoperative delirium. Findings were validated in an independent, comparable cohort using immuno-assays. ResultsIn the derivation cohort 53 patients were included, 35.8% developed postoperative delirium. We identified differences in levels of eight CSF proteins between patients with and without subsequent delirium: complement factor C3, contactin-1, fibulin-1 and I-beta-1,3-N-acetylglucosaminyltransferase were significantly lower in patients with postoperative delirium, while neural cell adhesion molecule-2, fibrinogen, zinc-α-2-glycoprotein and haptoglobin levels were significantly higher. In the validation cohort 21.2% of 52 patients developed postoperative delirium. Immuno-assays confirmed contactin-1 results although not statistically significant. Complement factor C3 was significantly higher in patients with postoperative delirium. ConclusionOur results show the complexity of pathophysiological mechanisms involved in delirium and emphasizes the need of independent validation of findings. General significanceThis study highlights the challenges and inconsistent findings in studies of delirium, a serious complication in older patients. We analysed proteins in CSF, the most proximal fluid to the brain. All patients were free from delirium at the time of sampling.

Intrathecal Analgesia for Chronic Refractory Pain: Current and Future Prospects.

The intrathecal drug-delivery system (IDDS) is one mode of infusing analgesic medications directly into the cerebrospinal fluid in close proximity to their site of action. This modality has been employed in patients with refractory pain either due to malignant or non-malignant causes for over 30 years. Unfortunately, and despite the number of years it has been in use, there is still a scarcity of rigorous evidence to guide its integration into clinical practice. Current best evidence is inconclusive as to the comparative effectiveness and harms of the IDDS relative to routine medical care of patients. There are far more systematic reviews than high-quality primary comparative studies of the IDDS vs. conventional pain treatment. Existing clinical practice recommendations are best viewed as expert opinion with competing interests. This article will review the existing literature for indications, contraindications, consensus statements, different technologies, and complications of the IDDS. Although approved analgesics for IDDS delivery are limited to morphine and ziconotide, many other analgesics, alone or in combination, are routinely used in this setting. This review will also focus on the pharmacology, clinical efficacy, and safety of intrathecal medications extensively used in clinical practice; including agents approved, unapproved, and under development.

Systems biology evaluation of cell-free amniotic fluid transcriptome of term and preterm infants to detect fetal maturity.

BackgroundAmniotic fluid (AF) is a proximal fluid to the fetus containing higher amounts of cell-free fetal RNA/DNA than maternal serum, thereby making it a promising source for identifying novel biomarkers that predict fetal development and organ maturation. Our aim was to compare AF transcriptomic profiles at different time points in pregnancy to demonstrate unique genetic signatures that would serve as potential biomarkers indicative of fetal maturation.MethodsWe isolated AF RNA from 16 women at different time points in pregnancy: 4 from 18 to 24 weeks, 6 from 34 to 36 weeks, and 6 from 39 to 40 weeks. RNA-sequencing was performed on cell-free RNA. Gene expression and splicing analyses were performed in conjunction with cell-type and pathway predictions.ResultsSample-level analysis at different time points in pregnancy demonstrated a strong correlation with cell types found in the intrauterine environment and fetal respiratory, digestive and external barrier tissues of the fetus, using high-confidence cellular molecular markers. While some RNAs and splice variants were present throughout pregnancy, many transcripts were uniquely expressed at different time points in pregnancy and associated with distinct neonatal co-morbidities (respiratory distress and gavage feeding), indicating fetal immaturity.ConclusionThe AF transcriptome exhibits unique cell/organ-selective expression patterns at different time points in pregnancy that can potentially identify fetal organ maturity and predict neonatal morbidity. Developing novel biomarkers indicative of the maturation of multiple organ systems can improve upon our current methods of fetal maturity testing which focus solely on the lung, and will better inform obstetrical decisions regarding delivery timing.Electronic supplementary materialThe online version of this article (doi:10.1186/s12920-015-0138-5) contains supplementary material, which is available to authorized users.

Prostaglandin E2 increases proximal tubule fluid reabsorption, and modulates cultured proximal tubule cell responses via EP1 and EP4 receptors

Renal prostaglandin (PG) E2 regulates salt and water transport, and affects disease processes via EP1–4 receptors, but its role in the proximal tubule (PT) is unknown. Our study investigates the effects of PGE2 on mouse PT fluid reabsorption, and its role in growth, sodium transporter expression, fibrosis, and oxidative stress in a mouse PT cell line (MCT). To determine which PGE2 EP receptors are expressed in MCT, qPCR for EP1–4 was performed on cells stimulated for 24 h with PGE2 or transforming growth factor beta (TGFβ), a known mediator of PT injury in kidney disease. EP1 and EP4 were detected in MCT, but EP2 and EP3 are not expressed. EP1 was increased by PGE2 and TGFβ, but EP4 was unchanged. To confirm the involvement of EP1 and EP4, sulprostone (SLP, EP1/3 agonist), ONO8711 (EP1 antagonist), and EP1 and EP4 siRNA were used. We first show that PGE2, SLP, and TGFβ reduced H3-thymidine and H3-leucine incorporation. The effects on cell-cycle regulators were examined by western blot. PGE2 increased p27 via EP1 and EP4, but TGFβ increased p21; PGE2-induced p27 was attenuated by TGFβ. PGE2 and SLP reduced cyclinE, while TGFβ increased cyclinD1, an effect attenuated by PGE2 administration. Na-K-ATPase α1 (NaK) was increased by PGE2 via EP1 and EP4. TGFβ had no effect on NaK. Additionally, PGE2 and TGFβ increased fibronectin levels, reaching 12-fold upon co-stimulation. EP1 siRNA abrogated PGE2-fibronectin. PGE2 also increased ROS generation, and ONO-8711 blocked PGE2-ROS. Finally, PGE2 significantly increased fluid reabsorption by 31 and 46% in isolated perfused mouse PT from C57BL/6 and FVB mice, respectively, and this was attenuated in FVB-EP1 null mice. Altogether PGE2 acting on EP1 and EP4 receptors may prove to be important mediators of PT injury, and salt and water transport.

One physiology does not fit all: a path from data variability to "physiogenetics"?

Data variability is a costly complication of biomedical experimentation because the same experiment must be repeated a sufficient number of times so that the sample mean becomes a credible representation of the entire population. Since sampling is ideally done randomly in populations normalized for environmental and genetic backgrounds, data variability is viewed as a purely statistical issue reflecting the distribution in the population and captured as the standard deviation of the sampled data. The factors contributing to data variability are not analyzed by statistical methods; for want of a better explanation, data scatter is simply attributed to random noise and/or methodological limitations. In this commentary, evidence is discussed that documents an important role of interindividual biological diversity as a cause for data variability based on studies in which repeated sampling in the same individual permitted statistical comparisons between individuals in the same sample. Significant differences were found for proximal fluid reabsorption and plasma renin concentration between sample means of individuals of the same population. Furthermore, arterial blood pressure varied significantly between individual mice independently of strain and sex. Recognition of the extent of interindividual variability has important implications for data reproducibility, data collection, and data presentation in physiological research. Such nonrandom data variability may have different causes, but DNA modifications by genetic or epigenetic mechanisms could generate phenotype variants without being associated with disease symptoms. Exploration of the heritability of phenotypical diversity in physiology may be defined as "physiogenetics," and it would thus be the physiological corollary of pharmacogenetics and pharmacogenomics.

Exploring alternative ovarian cancer biomarkers using innovative nanotechnology strategies.

Our increased understanding of ovarian cancer's blueprints (mediated by DNA and RNA) and behavior (mediated by proteins) points to wide differences across patients that cannot be depicted by histology alone. Conventional diagnosis usually entails an adequate tissue biopsy, which limits serial testing. There is thus a motivation to shift towards easier to obtain clinical samples (e.g., ascites or blood). In response, investigators are increasingly leveraging alternative circulating biomarkers in blood or proximal fluids and harnessing novel profiling platforms to help explore treatment-related effects on such biomarkers in serial fashion. In this review, we discuss how new nanotechnologies we developed intersect with alternative ovarian cancer biomarkers for improved understanding of metastases and therapeutic response.

Oropharyngeal aspiration of Burkholderia mallei and Burkholderia pseudomallei in BALB/c mice.

Burkholderia mallei and Burkholderia pseudomallei are potentially lethal pathogens categorized as biothreat agents due, in part, to their ability to be disseminated via aerosol. There are no protective vaccines against these pathogens and treatment options are limited and cumbersome. Since disease severity is greatest when these agents are inhaled, efforts to develop pre- or post-exposure prophylaxis focus largely on inhalation models of infection. Here, we demonstrate a non-invasive and technically simple method for affecting the inhalational challenge of BALB/c mice with B. pseudomallei and B. mallei. In this model, two investigators utilized common laboratory tools such as forceps and a micropipette to conduct and characterize an effective and reproducible inhalational challenge of BALB/c mice with B. mallei and B. pseudomallei. Challenge by oropharyngeal aspiration resulted in acute disease. Additionally, 50% endpoints for B. pseudomallei K96243 and B. mallei ATCC 23344 were nearly identical to published aerosol challenge methods. Furthermore, the pathogens disseminated to all major organs typically targeted by these agents where they proliferated. The pro-inflammatory cytokine production in the proximal and peripheral fluids demonstrated a rapid and robust immune response comparable to previously described murine and human studies. These observations demonstrate that OA is a viable alternative to aerosol exposure.

77.: Uncovering the therapeutic mechanism of blood patching for treatment of spontaneous cerebrospinal fluid leaks

The mechanism of action for lumbar blood patches affecting a therapeutic response in a proximal cerebrospinal fluid (CSF) leak is thought to be via a tamponade effect. However, our case study reveals that blood products reach and pool at the site of a proximal CSF leak in the cervical spine – therefore we hypothesise that the therapeutic response results from a combination of a tamponade effect and blood products forming a localised clot in the proximal cervical region. We present a 41-year-old woman with a 12 month history of headache from postural hypotension. The patient’s general practitioner ordered a CT scan of the brain and lumbar spine as part of a workup which revealed that the patient had a cervical spine CSF leak. Subsequent MRI confirmed the CSF leak and intracranial hypotension. A 25 ml epidural blood patch was performed in the lumbar region together with conservative measures including a period of strict bed rest for days with increased hydration and caffeine intake. The patient reported an immediate symptomatic improvement following blood patching with a reduction in headaches. Subsequent imaging revealed resolution of the intracranial hypotension. We followed up the patient with serial MRI scans. These revealed blood reaching and pooling around the site of the CSF leak in the cervical spine. The current case report demonstrates that a lumbar epidural injection of blood reaches and pools around a CSF leak as far proximally as the cervical region. This supports the “plug” theory as the mechanism for persistent symptom resolution. However, the mechanism of immediate symptomatic improvement may still involve a tamponade effect. This two stage process appears to be the best explanation for the therapeutic response obtained from epidural blood patching on the basis of the available clinical, imaging and experimental data.

Oncology

The June 2014 Oncology Roundup360 looks at: Infection still a problem in endoprosthetic reconstruction; massive allografts not as successful as we perhaps think; curopsy for aneurysmal bone cysts?; lengthening prosthesis: days are numbered; new WHO classification in brief; proximal tumours and fluid levels: bad news; infection is predictable in orthopaedic oncology; psychosocial support key in oncological outcomes.

Seminal plasma as a diagnostic fluid for male reproductive system disorders

Molecular biomarkers hold promise to advance the noninvasive diagnosis of male reproductive system disorders and facilitate the identification and management of these conditions through screening, early diagnosis and more accurate prognosis. Seminal plasma has great potential as a proximal fluid for protein biomarker discovery and as a clinical sample for noninvasive diagnostics. The seminal plasma proteome contains thousands of proteins and includes a large number of tissue-specific proteins that might accurately indicate a pathological process in the tissue of origin. Potential protein biomarkers for male reproductive system disorders are more abundant in seminal plasma than in blood serum or urine, and, therefore, are more easily identified and quantified in semen by mass spectrometry and other techniques. These methods have enabled elaboration of the composition of the seminal plasma proteome and the tissue specificity of seminal plasma proteins. Strategies have been developed to discover protein biomarkers in seminal plasma through integrated 'omics' approaches. Biomarkers of male infertility and prostate cancer are now emerging, and it is evident that seminal plasma has the potential to complement other diagnostic tools available in urology clinics.

Comparative Pathology of Neurovirulent Lineage 1 (NY99/385) and Lineage 2 (SPU93/01) West Nile Virus Infections in BALBc Mice

The pathology in mice infected with neurovirulent South African lineage 2 West Nile virus (WNV) strains has not previously been described. Three- to 4-month-old male BALBc mice were infected with South African neurovirulent lineage 2 (SPU93/01) or lineage 1 (NY385/99) WNV strains and the gross and microscopic central nervous system (CNS) and extra-CNS pathology of both investigated and compared. Mice infected with both lineages showed similar illness, paralysis, and death from days 7 to 11 postinfection (PI). Two survivors of each lineage were euthanized on day 21 PI. WNV infection was confirmed by nested real-time reverse transcription polymerase chain reaction of tissues, mostly brain, in the majority of mice euthanized sick or that died and in 1 healthy lineage 2 survivor. Gross lesions caused by both lineages were identical and included marked gastric and proximal small intestinal fluid distension as described in a previous mouse study, but intestinal microscopic lesions differed. CNS lesions were subtle. Immunohistochemical (IHC)-positive labeling for WNV E protein was found in neurons multifocally in the brain of 3 lineage 1-infected and 3 lineage 2-infected mice from days 9 to 11 PI, 4 of these including brainstem neurons, and of cecal myenteric ganglion neurons in 1 lineage 2-infected day 8 PI mouse. Findings supported hypotheses in hamsters that gastrointestinal lesions are likely of brainstem origin. Ultrastructurally, virus-associated cytoplasmic vesicular or crystalline structures, or amorphous structures, were found to label IHC positive in control-positive avian cardiomyocytes and mouse thalamic neurons, respectively, and WNV-like 50-nm particles, which were scarce, did not label.

Primary Effusion Lymphoma: Secretome Analysis Reveals Novel Candidate Biomarkers with Potential Pathogenetic Significance

Primary Effusion Lymphoma: Secretome Analysis Reveals Novel Candidate Biomarkers with Potential Pathogenetic Significance

Application of Proteomic Technologies to Discover and Identify Biomarkers for Periodontal Diseases: Moesin is a Potential Mediator and Biomarker for Periodontal Disease

As a fluid in close proximity to periodontal tissue, the Gingival Crevicular Fluid (GCF) is the principal target in the search for biomarkers of periodontal disease, because its protein composition may reflect disease pathophysiology. For the identification of novel GCF biomarkers of periodontal disease, GCF samples from five patients with severe periodontal disease were analyzed by liquid chromatography-mass spectrometry/mass spectrometry. Two hundred twenty-five proteins were identified as possible candidates for GCF biomarkers. Of these marker candidates, we focused on a protein not well studied in periodontal disease, i.e., moesin, a member of the ezrin– radixin–moesin family. Western blotting analysis revealed that moesin expression in GCF was higher in patients with severe periodontal disease than in controls. We further examined moesin protein expression levels in human gingival fibroblasts (HGFs) following stimulation with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Moesin expression in HGFs was found to be increased by LPS treatment in a dose-dependent manner. Our findings suggest that moesin may be involved in progression of periodontal disease and is a potential biomarker of periodontal disease.

Synthesis of pH-responsive mesoporous silica nanotubes for controlled release

A novel mesoporous silica tubes (MMT) which possessed pH-sensitive controlled release ability had been fabricated and synthesized by using carbon nanotubes (CNTs) as template. The sample replicated the morphologies of the CNTs successfully. The Brunauer–Emmett–Teller surface area of the materials can reach 1,017 m2 g−1 with the pore size of 3.8 nm. As a model drug, metformin HCl was applied to study the drug loading and control release ability of the materials. MMT possesses higher drug loading ratio (36 %) than that of MCM-41 (27.5 %). The release kinetics were studied in simulated gastric fluid (pH = 1.2) and in simulated proximal intestine fluid (pH = 7. 4), respectively. The result shows that the delivery systems exhibit well pH-sensitive control release ability and the as-synthesized materials have potential application in biomedical field.

Multifunctional SBA-15 for magnetically oriented and pH targeted delivery of ibuprofen

A magnetic and pH targeting drug delivery system based on the magnetic nanocomposite doping mesoporous silica material has been successfully prepared. The material exhibited highly ordered mesostructure, large Brunauer–Emmett–Teller surface area, high pore volume, regular nanoparticle morphology and superior magnetic property. The structure and properties of the magnetic mesoporous nanocomposites were characterised by X-ray diffraction, scanning electron microscope, transmission electron microscope, N2 adsorption–desorption, Fourier transform infrared spectroscopy and vibrating sample magnetometer technique. The as obtained magnetic mesoporous material was used as drug carrier, and ibuprofen was used as model drug. The releases in simulated proximal intestine fluid (pH 7·4) and simulated gastric fluid (pH 1·2) were studied. Therefore, a novel multifunctional drug delivery system with magnetically oriented and alkalescence site targeted release has been obtained.

Significant water absorption goes paracellular in kidney proximal tubules

it had been a fundamental dispute for several decades, whether water passes epithelia such as kidney proximal tubule or small intestine along the transcellular, paracellular, or both pathways. By discovery of the transmembranal aquaporin water channels (AQP), the molecular basis of the

Fluid reabsorption in proximal convoluted tubules of mice with gene deletions of claudin-2 and/or aquaporin1

Deletions of claudin-2 (Cldn2) and aquaporin1 (AQP1) reduce proximal fluid reabsorption (PFR) by about 30% and 50%, respectively. Experiments were done to replicate these observations and to determine in AQP1/claudin-2 double knockout mice (DKO) if the effects of deletions of these established water pores are additive. PFR was determined in inactin/ketamine-anesthetized mice by free-flow micropuncture using single-nephron I(125)-iothalamate (io) clearance. Animal means of PFR [% of glomerular filtration rate (GFR)] derived from TF/Piothalamate ratios in 12 mice in each of four groups [wild type (WT), Cldn2(-/-), AQP1(-/-), and DKO) were 45.8 ± 0.85 (51 tubules), 35.4 ± 1 (54 tubules; P < 0.01 vs. WT), 36.8 ± 1 (63 tubules; P < 0.05 vs. WT), and 33.9 ± 1.4 (69 tubules; P < 0.01 vs. WT). Kidney and single-nephron GFRs (SNGFR) were significantly reduced in all mutant strains. The direct relationship between PFR and SNGFR was maintained in mutant mice, but the slope of this relationship was reduced in the absence of Cldn2 and/or AQP1. Transtubular osmotic pressure differences were not different between WT and Cldn2(-/-) mice, but markedly increased in DKO. In conclusion, the deletion of Cldn2, AQP1, or of both Cldn2 and AQP1 reduces PFR by 22.7%, 19.6%, and 26%, respectively. Our data are consistent with an up to 25% paracellular contribution to PFR. The reduced osmotic water permeability caused by absence of AQP1 augments luminal hypotonicity. Aided by a fall in filtered load, the capacity of non-AQP1-dependent transcellular reabsorption is sufficient to maintain PFR without AQP1 and claudin-2 at 75% of control.

On the Characterization of a Non-Newtonian Blood Analog and Its Response to Pulsatile Flow Downstream of a Simplified Stenosis

Particle image velocimetry (PIV) was used to investigate the influence of a non-Newtonian blood analog of aqueous xanthan gum on flow separation in laminar and transitional environments and in both steady and pulsatile flow. Initial steady pressure drop measurements in laminar and transitional flow for a Newtonian analog showed an extension of laminar behavior to Reynolds number (Re) ~ 2900 for the non-Newtonian case. On a macroscale level, this showed good agreement with porcine blood. Subsequently, PIV was used to measure flow patterns and turbulent statistics downstream of an axisymmetric stenosis in the aqueous xanthan gum solution and for a Newtonian analog at Re ~ 520 and Re ~ 1250. The recirculation length for the non-Newtonian case was reduced at Re ~ 520 resultant from increased viscosity at low shear strain rates. At Re ~ 1250, peak turbulent intensities and turbulent shear stresses were dampened by the non-Newtonian fluid in close proximity to the blockage outlet. Although the non-Newtonian case's recirculation length was increased at peak pulsatile flow, turbulent shear stress was found to be elevated for the Newtonian case downstream from the blockage, suggesting shear layer fragmentation and radial transport. Our findings conclude that the xanthan gum elastic polymer prolongs flow stabilization, which in turn emphasizes the importance of non-Newtonian blood characteristics on the resulting flow patterns in such cardiovascular environments.

PTU-163 Proximal Oesophageal Functional Mucosal Integrity during Distal Oesophageal Acidification in Patients with Nerd and FH

IntroductionAlthough macroscopically normal, the oesophageal mucosa in patients with non-erosive reflux disease (NERD) displays epithelial dilated intercellular spaces (DIS). Such loss of barrier integrity is thought to be important in...

37 Luminal Acid-Associated Post-Prandial Epithelial Hypoxia Maintains the Expression of Iron Absorptive DMT1 and DCYTB, and Cyclooxygenases

Background: We recently identified Slc26a9 as an anion conductance that is upregulated in airway inflammation and prevents bronchial mucus obstruction (Anagnostopoulou et al. JCI 2012). Slc26a9 variants were recently found associated with meconium ileus in cystic fibrosis infants (Sun et al. Nature 2012). Aim: The association with meconium ileus raises the question where Slc26a9 is expressed in the gastrointestinal tract and what is its function. Methods: Acid, HCO3, short circuit current (Isc) measurements were performed in isolated mucosa and acid, HCO3 , and fluid absorptive and secretory rates were measured by single pass perfusion and back titration in anesthetized Slc26a9 KO and WT mice by inhalation of 2.0% isoflurane. Slc26a9 cellular expression was studied by laser dissection and qPCR, and quantitative morphometry was performed in the different segments of the murine gastrointestinal tract. Results: Slc26a9 was found highly expressed in the mucosae of the upper gastrointestinal tract, with abrupt decrease of expression levels to virtually undectable levels beyond the duodenum. As previously reported, Slc26a9 KO mice had completely lost the ability to secrete acid in adulthood. However, Slc26a9 was found highly expressed along the whole gastric gland, even in areas without H+,K+-ATPase expression. Proximal duodenal bicarbonate and fluid secretory rates, which are higher in the proximal than the distal duodenum in WT mice, as well as the ability to stimulate these rates with forskolin, were reduced in the absence of Slc26a9 expression. The gastric antrum, as well as the fundus (after omeprazole treatment to rule out any residual acid secretory capacity) was studied to test whether Slc26a9 transports HCO3 itself. Gastric antrum, while expressing high Slc26a9 levels in WT mice, had lower basal and forskolin-stimulated HCO3 rate as well as lower Isc response in WT than KO mice, arguing against a role of Slc26a9 as a HCO3 transporter. Morphometry revealed strongly elongated fundic as well as antral glands, and slightly elongated proximal duodenal villi as well as crypts. Conclusions: Slc26a9 expression is necessary for normal gastric acid and proximal duodenal bicarbonate secretion, but it is not expressed inmore distal parts of the gastrointestinal mucosa. The increased risk for meconium ileus may be due to loss of digestive function of the stomach and proximal duodenum.