Acute stress increases permeability of the blood-brain-barrier through activation of brain mast cells

Disruption of the blood-brain-barrier (BBB) is important in the pathophysiology of various inflammatory conditions of the central nervous system (CNS), such as multiple sclerosis (MS), in which breakdown of the BBB precedes any clinical or pathological findings. There is some evidence that relapsing-remitting MS attacks may be correlated with certain types of acute stressful episodes. Stress typically activates the hypothalamic-pituitary-adrenal (HPA) axis through the release of corticotropin releasing hormone (CRH), leading to production of glucocorticoids that down regulate immune responses. However, acute stress also has pro-inflammatory effects that appear to be mediated through activation of mast cells. Here we show that acute stress by immobilization increased permeability of rat BBB to intravenous 99Technetium gluceptate (99Tc). This effect was statistically significant in the diencephalon and the cerebellum, while it was absent in the cerebral cortex where there are not mast cells. Immobilization stress also induced activation of mast cells in diencephalon, the site where most mast cells are found in the rat brain. Both BBB permeability and mast cell activation were inhibited by the 'mast cell stabilizer' disodium cromoglycate (cromolyn). These results expand the pathophysiology of mast cells and implicate them in CNS disorders, that may possibly be induced or exacerbated by stress.     

Thiocyanatochromium(III) complexes with pilocarpine and the analytical determination of this alkaloid (author's transl)]

Thiocyanatochromium(III) Complexes with Pilocarpine and the Analytical Determination of this Alkaloid A new reinecke salt-like compound NH₄[Cr(NCS)₄ (pilocarpine)₂] · H₂O was obtained from K₃[Cr(NCS)₆] and pilocarpine in the molten state. The constitution of the complex anion was proven by means of a series of double decomposition reactions with amines and cobalt(III)-amine bases. The structure and the thermal stability of the title compound were studied by means of UV and IR spectroscopy and derivatography. The slightly soluble compounds pilocarpine H[Cr(NCS)₄ (aniline)₂] and pilocarpine · H[Cr(NCS)₄ (morpholine)₂] were used for the oxidimetric and spectrophotometric determination of pilocarpine.     

Preparation and characterisation of poly(vinyl alcohol)/cyclodextrin microspheres as matrix for inclusion and separation of drugs

Poly(vinyl alcohol) (PVA) microspheres containing cyclodextrin (CD) were obtained by chemical cross-linking with glutaraldehyde of an acidified mixture solution of PVA and alpha-, beta- or gamma-CD. The amount of linked CD in microspheres, estimated by tetrazolium blue method, decreases in the order beta- > gamma- > alpha-CD. The dimensions of PVA/gamma-CD microspheres are much higher than those of PVA/alpha- and beta-CD. The cross-linking density of microspheres was estimated by the amount of iodine retained by the polymer matrix. The pore size as well as the porous volume of PVA/CD microspheres decrease significantly on increasing the amount of glutaraldehyde, but are enough large to permit the access of drugs to the CD cavity. In order to test the PVA/CD microsphere inclusion ability, the microspheres were packed in a glass column and the liquid chromatographic behaviour by isocratic elution of different drugs or typical organic compounds, taken as model drugs, was investigated.     

Free flaps for type III complex pharyngoesophageal defects after enlarged ablative surgery for advanced cancer of larynx and hypopharynx

Free tissue transfer has become a useful technique for reconstruction of type III complex pharyngoesophageal defects after enlarged laryngectomy and partial or total pharyngoesophageal resection. We present a retrospective analysis of our experience with 36 patients who received free flaps for reconstruction of complex pharyngoesophageal defects associated with skin and soft-tissue defects. Free fasciocutaneous flaps and jejunum combined with a deltopectoral flap and musculocutaneous pectoralis major flap, gastro-omental flap, and combined latissimus dorsi musculocutaneous and cutaneous scapular flaps were used for reconstruction. Adjuvant therapy included preoperative or postoperative radiotherapy. Free flap failure occurred in 2 of 36 patients. Twenty-eight patients had good swallowing function. Better results with fewer complications in reconstruction of type III complex pharyngoesophageal defects were obtained with the use of a combined latissimus dorsi and scapular flap.     

Expression of EGFR in Paired New and Recurrent Glioblastomas

Background: The aim of this study was to analyse the expression of EGFR in newly diagnosed and recurrent glioblastoma multiforme (GBM). Materials and Methods: Our study included a total of 48 paired samples collected from 24 patients diagnosed with GBM. The intensity of EGFR cytoplasmatic staining was scored on a scale of 1-3 (weak, intermediate or strong). Results: We found EGFR overexpression in 23 patients (96%) with newly diagnosed GBM, while all recurrent tumours overexpressed EGFR. Ten recurrent tumours (42%) had a lower expression than their new counterpart 13 tumours (54%) had a similar expression, and only one case (2%) had increased expression on recurrence. The expression of EGFR in newly diagnosed GBM was significantly correlated with EGFR expression in recurrent tumour (p 0.036). In addition, new GBMs with strong EGFR expression had a mean relapse-free interval of 11.5 months (p0.017). A benefit of combined therapy was observed in the radiotherapy-plus-chemotherapy group where the average time was 11 months (p0.011), as compared with surgery/radiotherapy alone (average time 6.8 months). Conclusions: The present data show that EGFR is overexpressed in paired GBMs. The discrepancies of EGFR expression between the primary tumour and the recurrence suggest heterogeneity of GBMs but also unity at relapse.     

Designing of Novel Carbonic Anhydrase Inhibitors and Activators

Carbonic anhydrases (CAs, EC 4.2.1.1) are wide spread enzymes, present in mammals in at least 14 different isoforms: some of these isozymes are cytosolic (CA I, CA II, CA III, CA VII), while others are membrane-bound (CA IV, CA IX, CA XII and CA XIV); CA V is mitochondrial, and CA VI is secreted in the saliva. Three acatalytic forms are also known (CARP VIII, CARP X and CARP XI). Several important physiological and physio-pathological functions are played by many CA isozymes, which are strongly inhibited by aromatic and heterocyclic sulfonamides. The catalytic and inhibition mechanisms of these enzymes are understood in great detail, and this greatly helped in the design of potent inhibitors, some of which possess important clinical applications. The use of such CA inhibitors (CAIs) as antiglaucoma drugs will be discussed in detail, together with the recent developments that led to isozyme-specific and organ-selective inhibitors. A recent discovery is connected with the involvement of CAs and their sulfonamide inhibitors in cancer: many potent CAIs were shown to inhibit the growth of several tumor cell lines in vitro and in vivo, constituting thus interesting leads for developing novel antitumor therapies. Future prospects for drug design applications for inhibitors of these ubiquitous enzymes will be dealt with. Although activation of CAs has been a controversial issue for some time, recent kinetic, spectroscopic and X-ray crystallographic experiments offered an explanation for this phenomenon, based on the catalytic mechanism. It has been demonstrated recently, that molecules that act as carbonic anhydrase activators (CAAs) bind at the entrance of the enzyme active site participating in facilitated proton transfer processes between the active site and the reaction medium. In addition to CA II--activator adducts, X-ray crystallographic studies have also been reported for ternary complexes of this isozyme with activators and anion (azide) inhibitors. Structure-activity correlations for diverse classes of activators will be discussed for the isozymes for which the phenomenon has been studied, i.e., CA I, II, III and IV. The possible physiologic relevance of CA activation will also be addressed, together with the recent pharmacological applications of blood CA isozymes activators, as potential memory enhancing drugs.     

fMRI mapping of a morphed continuum of 3D shapes within inferior temporal cortex

Here, we mapped fMRI responses to incrementally changing shapes along a continuous 3D morph, ranging from a head ("face") to a house ("place"). The response to each shape was mapped independently by using single-stimulus imaging, and stimulus shapes were equated for lower-level visual cues. We measured activity in 2-mm samples across human inferior temporal cortex from the fusiform face area (FFA) (apparently selective for faces) to the parahippocampal place area (PPA) (apparently selective for places), testing for (i) incremental changes in the topography of FFA and PPA (predicted by the continuous-mapping model) or (ii) little or no response to the intermediate morphed shapes (predicted by the category model). Neither result occurred; instead, we found approximately linearly graded changes in the response amplitudes to graded-shape changes, without changes in topography-similar to visual responses in different lower-tier cortical areas.     

Considerations on in vitro and in vivo magnetic nanoparticles hemocompatibility testing

The aim of this paper is to summarize few aspects and underline some difficulties that hemocompatibility testing come up. The purpose of hemocompatibility testing is to look for possible undesirable changes in the blood caused directly by a medical device, by chemicals leaching from a device or biomaterials. Undesirable effects of device materials on the blood may include alterations in coagulation parameters, thrombus formation, hemolysis, and immunological changes. For each different event the literature is rich in showing tests, not different in principle, but in testing conditions. ISO 10993-4 describes hemocompatibility tests in five different categories (thrombosis, coagulation, platelets, hematology, and immunology). Here we put together the tests that ISO 10993 and/or American Society for Testing and Materials (ASTM) suggest to evaluate hemocompatibility and we emphases on their utility for magnetic nanoparticules testing. The individual tests are not discussed in detail; they may be performed either in vivo or, preferably, in vitro. For each test we made few considerations with criticism. There is still some uncertainty with respect to what is actually required by the regulatory authorities for the hemocompatibility test, and there is still no harmony between ASTM and ISO 10993 regulations regarding some aspects to be standardised.