Drug delivery and in vitro models of the blood-brain barrier

An understanding of the physiology of the blood-brain barrier (BBB) is crucial when addressing complex issues such as drug delivery, pathogenesis of chronic neurological diseases and bio-defense. Rational central nervous system (CNS) drug design cannot entirely and exclusively rely upon the physicochemical properties of putative neurotherapeutics, since lipophilicity alone is a poor predictor for drug penetration into the CNS. This is particularly true for three large families of CNS drugs: antineoplastics, antivirals and anti-epileptics. For these drugs, in contrast to peripheral acting drugs (eg, antihistamines), negligible penetration across the BBB is preferable in order to avoid CNS side effects. Studies performed using small animals such as rodents cannot be directly extrapolated to human brain tissue, as demonstrated by both clinical and in vitro studies. Furthermore, most of the promising CNS drugs that proved effective in vitro have failed in clinical trials due to misleading predictive permeability data extrapolated from models that were not capable of fully reproducing the functional properties of the BBB in vivo. Therefore, a great effort has been made to develop new in vitro models able to reproduce the physiological, anatomical and functional characteristics of the BBB allowing for a better prediction of drug penetration across the BBB, and enabling the design of new pharmaceutical strategies to bypass the shielding of brain parenchyma. Herein we provide a detailed review and discussion of currently employed in vitro BBB models along with probable future developments.     

Significance of CA 125 serum level in discrimination between benign and malignant masses in the pelvis

Aim Our aim was to confirm that preoperative CA 125 serum level can be useful for discrimination between benign and malignant masses in the pelvis.Methods Preoperative CA 125 serum level was analyzed retrospectively in 121 patients who had surgery because of a malignant ovarian tumor and in 91 patients with benign masses in the pelvis. The cutoff serum level CA 125 between benign and malignant masses in the pelvis was 35 and 65 IU/ml.Results Of those patients with a malignant ovarian tumor, 65.3% had menopause whereas only 31.5% of those with a benign tumor did so. The average age of the patients with a malignant tumor was 54.2 years and of those with a benign tumor 46.8 years. The preoperative CA 125 serum level was higher than 35 IU/ml in 80.2% and higher than 65 IU/ml in 72.7% of all analyzed patients with a malignant tumor, whereas it was 23.9% and 9.8% respectively in patients with a benign mass. In early stage ovarian cancer disease (borderline stage, I/II) the preoperative CA 125 serum level was higher than 35 IU/ml in 67.8% and in 52.5% higher than 65 IU/ml. In advanced stages (III/IV), it was higher than 35 and 65 IU/ml in 96.1%. After therapy the CA 125 serum level dropped below 35 IU/ml in 70.8% and after three chemotherapy courses in 78.1%. A CA 125 level less than 35 IU/ml was achieved by therapy in 84.2% patients with an early stage disease (I/II) and in 62.1% in advanced stages (III/IV). The calculated sensitivity was 80.2% and negative 74.5% (CA 125 higher than 35 IU/ml) and 72.7%, 90.2%, 90.7%, 71.6% respectively (CA 125 higher than 65 IU/ml).Conclusion Preoperative determination of CA 125 is a very useful method to discriminate between benign and malignant masses in the pelvis.     

Peripheral detection of S100β during cardiothoracic surgery: what are we really measuring?

Background

S100β has been used in cardiac surgery to identify patients with postoperative neurologic complications. However, extracranial proteins may falsely elevate measurements of serum S100β;. Objectives of this study were (1) to quantify S100β levels in serum and pericardial cavity during coronary artery bypass grafting (CABG), and (2) to identify proteins recognized by standard immunodetection as S100β.

Methods

Systemic and pericardial cavity blood from 5 patients undergoing CABG were sampled before, during, and after cardiopulmonary bypass (CPB). A commercially available enzyme-linked immunosorbent assay (ELISA) kit was used to quantify S100β. Two-dimensional gel electrophoresis, Western blot, and mass spectroscopy were also performed to identify S100â and other proteins.

Results

Mean S100β levels measured by ELISA, systemic and pericardial cavity blood were (in ng · mL⁻¹) 1.0 ± 0.46 and 111 ± 71 before CPB, 0.6 ± 0.11 and 113 ± 54 during CPB, and 1.7 ± 0.64 and 101 ± 42 after CPB, respectively. However, gel electrophoresis and Western blot analysis revealed proteins other than S100β to be present in the pericardial cavity giving a falsely elevated serum S100â levels measured by immunoassay. Mass spectroscopy of identified potential candidates revealed contaminants including haptoglobin I precursor, apolipoprotein A-1 precursor, complement factor B precursor, and complement C3 precursor.

Conclusions

S100β immunoassays are not specific for S100â and give a falsely elevated reading due to contaminants from the surgical field that cross react with the assay's antibody. This does not appear to be an issue in nonsurgical patients. Caution must be exerted when evaluating immunodetection results for low-abundance proteins under conditions where contamination of the sample is likely.     

CD95/Fas expression on peripheral blood T lymphocytes in patients with multiple sclerosis: effect of high-dose methylprednisolone therapy

Recent data indicate that the apoptotic process, mediated by the CD95/Fas cell surface receptor, is impaired in activated lymphocytes of patients with relapsing-remitting multiple sclerosis. Using flow cytometric-immunophenotyping, we analyzed the expression of CD95/Fas on peripheral blood CD4+ and CD8+ T lymphocytes (PBL) in 10 MS patients in relapse, and the effect of pulse corticosteroid therapy on the apoptosis of autoreactive lymphocytes. The proportions of CD8+ and CD8+CD95+ T lymphocytes were significantly higher in MS patients in relapse before than after pulse corticosteroid therapy. Conversely, the proportions of CD4+ and CD4+CD95+ T cells were significantly lower before than after therapy, but not significantly different from healthy persons. The different expression of CD95/Fas on peripheral blood CD8+ T lymphocytes in relapsing RRMS and in healthy controls suggests a possible involvement of apoptosis in the pathogenesis of MS. Our results also show that pulse corticosteroid therapy influences the CD95/Fas expression on CD8+ and CD4+ T lymphocytes in patients with RRMS.     

Fluorine-18-fluorodeoxyglucose positron emission tomography metabolic imaging in patients with lymphoma

Fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) provides unique information about the metabolic behavior of the malignant tumors, independent of morphological criteria. This technique is more sensitive in imaging lymphoma prior to therapy than conventional computed tomography (CT) imaging and Ga-67 scintigraphy. FDG-PET performed in patients with lymphoma offers important additional information on the presence of viable disease in residual masses of the tumor. It is also of great value in assessing therapy response in patients with Hodgkin s disease and non-Hodgkin s lymphoma, because of its ability to differentiate between fibrosis and active tumor. More studies are needed to assess the value of this method in long-term follow-up. In our institution this method is mostly used for clarification of residual post-therapy abnormalities that fall under the category of unconfirmed/uncertain complete remission. Our preliminary data on 14 patients indicate that this non-invasive, metabolic imaging is superior to CT and other conventional diagnostic methods in the post-therapy staging of lymphoma.     

Azithromycin vs doxycycline in the treatment of inclusion conjunctivitis

PURPOSE: The aim of the study was to compare the efficacy and safety of azithromycin and doxycycline in the treatment of chlamydial conjunctivitis in adults. DESIGN: An open, randomized clinical trial. METHODS: Seventy-eight adult patients with incluson conjunctivitis were enrolled in this multicenter clinical study. Patients with chlamydial conjunctivitis as indicated by a positive direct fluorescent antibody (DFA) test or cell culture were randomized to receive a single 1-g dose of azithromycin or doxycycline, 100 mg twice daily for 10 days. A conjuctival swab for cell culture was obtained from all patients immediately before the treatment for subsequent confirmation of the presence of chlamydial infection in the central laboratory. Control examinations were performed 10 to 12 days and 4 to 6 weeks after the treatment initiation. Clinical and bacteriological responses to the treatment were evaluated at the last visit. The occurrence and frequency of adverse events were analyzed as well. RESULTS: Of 78 patients enrolled, 51 completed the study and were evaluated for efficacy. The main reasons for withdrawal were lack of confirmation of the presence of chlamydial infection by the central laboratory and failure to attend the follow-up visit. Eradication of C. trachomatis was achieved in 23 of 25 (92%) patients treated with azithromycin and in 25 of 26 (96%) patients treated with doxycycline. Clinical cure was observed in 15 (60%) and 18 (69%) patients treated with azithromycin and doxycycline, respectively. Both drugs were equally well tolerated. CONCLUSIONS: A single 1-g azithromycin therapy was as effective as standard 10-day treatment with doxycycline (100 mg twice daily) in the treatment of adult inclusion conjunctivitis.     

The use of cervical fascia for hypopharyngeal reconstruction with laryngeal preservation

Surgical resection of carcinomas of the posterior hypopharyngeal wall and reconstruction of defects with preservation of laryngeal function and swallowing are complex surgical problems. The various reconstructive procedures have been well described. There is no uniform agreement among surgeons as to which of the most frequently used techniques offers the best results. We use the cervical fascia in a new method for reconstruction of the posterior hypopharyngeal wall after carcinoma resection with preservation of laryngeal functions. Reconstruction with the fascia flap was used in eight selected patients. The surgical technique is easy and oncologically safe, with a short operative time and low complication rate. The cervical fascia proved to be good quality biological material for the reconstruction of two-dimensional defects. Functional results of swallowing, respiration and phonation have been satisfactory. Based on our experience and good results using the cervical fascia flap, this method has proven to be very beneficial in select patients with carcinoma of the posterior wall of the hypopharynx.     

Respiratory symptoms and pulmonary function among school-age children in the Aral Sea region

The saline Aral Sea in central Asia was once the 4th largest inland lake in the world. Desiccation of the Aral Sea as a result of diversion of inflow for irrigation has resulted in significant adverse health effects among residents of surrounding areas. This study was conducted to examine respiratory symptoms and function among children who lived in "the heavily affected disaster zone" (i.e., within 200 km of the Aral Sea), by comparing them with children who lived in "the slightly affected disaster zone" (i.e., located approximately 500 km from the Aral Sea). A questionnaire-based interview was conducted among 383 students 6-15 yr of age who lived in the study area and 432 students who lived in the reference area. Pulmonary function tests were completed by 337 children in the study area and 417 children in the reference area. Prevalence of current cough and current wheezing was higher among the study group participants. Percentage of predicted forced vital capacity (FVC% predicted) was lower in the study group (median = 96.6%) than in the reference group (median = 100.5%), and prevalence of restrictive pulmonary dysfunction was higher in the study group (10.6%) than in the reference group (2.6%). Multivariate analysis indicated that FVC% predicted was lower among females and in the study area, but was not associated with socioeconomic factors.