Blood inflammatory response to inhaled endotoxin in normal subjects

Previously we have reported that in asthmatics an inhalation of 20 μg lipopolysaccharide (LPS) produces a bronchial obstruction associated with an inflammatory blood response. The aim of the present study was to evaluate this response in normal subjects. Eight normal non-atopic subjects were challenged by inhalation of a solution containing 20 μg LPS (from Escherichia coli 026:B6) a week after bronchial challenge with control solution. The lung function response was evaluated by the changes in forced expiratory volume in one second (FEV₁), in specific conductance and in airway resistance while the blood inflammatory response was evaluated by serial measures of total white blood cells (WBC) and polymorphonuclear neutrophils (PMN) count, luminol enhanced-chemiluminescence (luminol-CL, as a marker of the PMN degree of activation), C-reactive protein (CRP), haptoglobin, complement fraction C3, tumour necrosis factor-α (TNF-α) and adrenocorticotropic hormone (ACTH). No response in lung function was observed for 6 h after the LPS inhalation. The count in WBC and PMN increased 300 (P < 0.01) and 360 (P < 0.01) min after the LPS challenge associated with an increase in the level of luminol-CL (P < 0.001). This rise in luminol-CL level was significant at 120 min (P < 0.05) before any change in the PMN count. After 24 and 48 h the acute-phase protein CRP raised significantly (P < 0.01), the other proteins C3 and haptoglobin being unchanged. A slight increase in ACTH was observed 240 and 360 min (P < 0.05) after the LPS challenge while the TNFα detectable level was not modified. In conclusion, in normal subjects, inhalation of a pro-inflammatory agent is able to induce a systemic inflammatory response in the absence of any effect on lung mechanics, while in asthmatics the same bronchial challenge has been reported to induce a similar blood inflammation associated with a significant response in lung function.     

Integration of Merged Delayed‐Enhanced Magnetic Resonance Imaging and Multidetector Computed Tomography for the Guidance of Ventricular Tachycardia Ablation: A Pilot Study

MDCT/MRI Fusion for the Guidance of VT Ablation . Background: Delayed enhancement (DE) MRI can assess the fibrotic substrate of scar‐related VT. MDCT has the advantage of inframillimetric spatial resolution and better 3D reconstructions. We sought to evaluate the feasibility and usefulness of integrating merged MDCT/MRI data in 3D‐mapping systems for structure–function assessment and multimodal guidance of VT mapping and ablation. Methods: Nine patients, including 3 ischemic cardiomyopathy (ICM), 3 nonischemic cardiomyopathy (NICM), 2 myocarditis, and 1 redo procedure for idiopathic VT, underwent MRI and MDCT before VT ablation. Merged MRI/MDCT data were integrated in 3D‐mapping systems and registered to high‐density endocardial and epicardial maps. Low‐voltage areas (<1.5 mV) and local abnormal ventricular activities (LAVA) during sinus rhythm were correlated to DE at MRI, and wall‐thinning (WT) at MDCT. Results: Endocardium and epicardium were mapped with 391 ± 388 and 1098 ± 734 points per map, respectively. Registration of MDCT allowed visualization of coronary arteries during epicardial mapping/ablation. In the idiopathic patient, integration of MRI data identified previously ablated regions. In ICM patients, both DE at MRI and WT at MDCT matched areas of low voltage (overlap 94 ± 6% and 79 ± 5%, respectively). In NICM patients, wall‐thinning areas matched areas of low voltage (overlap 63 ± 21%). In patients with myocarditis, subepicardial DE matched areas of epicardial low voltage (overlap 92 ± 12%). A total number of 266 LAVA sites were found in 7/9 patients. All LAVA sites were associated to structural substrate at imaging (90% inside, 100% within 18 mm). Conclusion: The integration of merged MDCT and DEMRI data is feasible and allows combining substrate assessment with high‐spatial resolution to better define structure–function relationship in scar‐related VT. (J Cardiovasc Electrophysiol, Vol. 24, pp. 419‐426, April 2013)     

Long-Lasting Catch-up Growth under Bio-Methionyl Growth Hormone Treatment in an Infant with Isolated Growth Hormone Deficiency Type 1A1

ABSTRACT. This case report concerns a 7-month-old infant with severe height retardation (–5.0 SD), typical growth hormone (GH)-deficient phenotype, and undetectable GH serum levels in response to three pharmacological stimuli. Diagnosis of isolated GH deficiency type 1A was confirmed by restriction endonuclease analysis of genomic DNA which pointed out GH-N gene deletion. The introduction of bio-methionyl-GH therapy in this patient was followed by a transient and clinically irrelevant appearance of low binding capacity GH antibodies as well as by a long-lasting catch-up growth (42.2 cm) which is continuing 44 months after beginning of treatment. This atypical pattern confirms that immune and growth response to exogenous GH in isolated GH deficiency 1A may be very heterogeneous.     

Optical Recordings of Ventricular Excitability of Frog Heart by an Extracellular Stimulating Point Electrode

To enhance understanding of the excitability of cardiac wusde during rest, an optical technique using the fluorescent voltage sensitive dye di-4-ANEPPS was used. Unlike conventional electrical recordings, optical recordings are free from electrical artifacts and. therefore, allow the observation of the transmembrane potential not only following the stimulation pulse, but also during the pulse itself Transmembrane potentials (V?_m) were recorded optically from frog ventricular epicardium in calcium containing Ringer's solution directly under an extracellular stimulating point electrode. Anodal and cathodal S stimuli were applied at rest. As observed by previous investigators, the post-pulse excitatory responses for cathodal pulses, compared with anodal pulses were greater. Changes in transmembrane potential (ΔV?_m) during the pulse were as expected for a passive cable only for low intensity pulses (< 4 × the cathodal threshold of excitation in diastole. CTE). However, at the higher intensities necessary to produce an excitatory response (> 6–8 × CTE), an “irregular” response in V?_m was observed—a reversal of the hyperpolarization during an anodal stimulus pulse and a reversal of the depolarization during a cathodal stimulus pulse. To elucidate further the biophysical basis for this behavior, ΔV?_m was mapped around the stimulating electrode. During stimulation, regions could be observed having a response with opposite polarity to that under the electrode (i.e. depolarization for an anodal pulse and hyperpolarization for a cathodal pulse). Removal of the bath solution or the addition of channel Mockers did not eliminate the occurrence of these regions. These regions appear to be the basis for the irregular behavior of ΔV?_m directly under the electrode as well as for anodal excitation.     

Synthesis and immunological characterization of a 134-mer synthetic peptide corresponding to the N-terminal half of the HIV-1 nucleoprotein,p24

A 134-mer peptide corresponding to the N-terminal sequence of p24 (residues 146–279 of the gag gene product of the LAV strain) was chemically synthesized using highly optimised protocols on an ABI 430A synthesizer. The crude peptide was obtained by treating the peptide-resin with HF, then purified by a combination of size exclusion and RP-HPLC. One hundred milligram of 90% pure 134-mer can be obtained within a month. Both mice and rabbit polyclonal antisera raised against a commercial preparation of recombinant p24, and a pooled sera from HIV-1 infected individuals reacted strongly with the 134-mer peptide in ELISA. Both mice and rabbits immunized with the free peptide emulsified in Freund's complete adjuvant generated strong anti-peptide and anti-p24 antibody responses as judged by immunoblots and ELISAs. Immunodominant epitopes were mapped to residues 201–227 (LKETINEEAAEWDRVHPVHAGPIAPG). These B-cell epitopes had previously been identified by mouse monoclonal antibodies raised against HIV-1 virus or gag gene products. Furthermore, murine T-cell lines generated against the 134-mer peptide were found to respond to two short peptides, P24B (residues 195–215) and P24D1 (residues 268–279). These two T-cell epitopes were previously reported as human helper T-cell and CTL epitopes, respectively. These results clearly indicate that the synthetic 134-mer peptide could elicit both T- and B-cell responses to HIV-1 similar to those obtained with the natural viral gag protein, and could be useful for the development of a synthetic HIV vaccine     

Relationships Between Histological and Functional Indices of Acute Chemically Induced Nephrotoxicity

Relationships Between Histological and Functional Indices ofAcute Chemically Induced Nephrotoxicity. Miyajima, H., Hewitt,W.R., Côté, M.G., and Plaa, G.L. (1983). Fundam.Appl. Toxicol. 3: 543–551. Acute renal injury was producedin rats with K₂Cr₂O₇ (5–40 mg/kg, sc) HgCl₂ (0.5–5.0mg/kg, sc) or cephaloridine (0.5–3.0 g/kg, sc). Histological(percentage of normal, degenerated or necrotic cells) and functionalindices (relative kidney weight, renal cortical slice accumulationof organic ions, and blood urea nitrogen content) were evaluated48 hours later. The relative sensitivity of each of these indiceswas determined for each nephrotoxicant. Renal cortical accumulationof organic ions appeared to be the most sensitive of the functionalparameters. A quantitative histological evaluation was foundto be as sensitive an indicator of nephrotoxicity as organicion accumulation. Alterations in each of the functional indiceswere significantly correlated with changes in renal histology.     

THE MOLECULAR CONTROL OF ANGIOGENESIS

Angiogenesis is a key event in a broad range of pathological conditions including both diseases with an enhanced and insufficient angiogensis. Angiogenesis is often intiated with vasodilation accompanied by an increase in vascular permeability. After destabilization of the vessel wall and degradation of the surrounding extracellular matrix, extravasation of plasma proteins provides a provisional scaffold for the migration of endothelial cells. Endothileal cell proliferation and migration themselves are under tight control by a balance of angionenesis inducers and inhibitors. A large number of angiogenic factors work together in a highly coordinated manner to induce endothelial cell outgrowth and the formation of functional vessels. On the other hand, angiostatic factor may play a critical role in the pathogenesis of ischemic diseases and contribute to the temination of physiological angiogenesis. Angiogenesis ends with the recruitment of pericytes and smooth muscle cells, which stabilize the newly formed vessel. The rapid increase in the knowledge about the molecular mechanisms of angiogenesis has led to first treatment trials in diseases with both enhanced and reduced angiogeneis. Although initial results are promising, much more work has to be done to consdier anti-angiogenic or pro-angiogenic approaches as reliable therapeutic tools.