Genetic engineering of allergens: future therapeutic products

Genetic engineering of allergens for specific immunotherapy should aim at the production of modified molecules with reduced IgE-binding epitopes (hypoallergens), while preserving structural motifs necessary for T cell recognition (T cell epitopes) and for induction of IgG antibodies reactive with the natural allergen (blocking antibodies). Common approaches for engineering of hypoallergens usually require knowledge of T and B cell epitopes and involve changing specific base pairs (mutated gene), introduction of a new piece of DNA into the existing DNA molecule (chimeric or hybrid gene), and deletions (truncated gene or fragments). DNA family shuffling has the advantage that it does not require a priori knowledge of structural and functional properties for efficient generation of hypoallergens. The combination of the hypoallergen concept with the Th1-inducing genetic immunization approach might be an attractive alternative for protein-based immunotherapy.     

Affective and psychotic symptoms relate to different types of P300 alteration in depressive disorder

BACKGROUND: Previous findings of P300 alterations in depressive disorder have been controversial. We therefore used multivariate methods to study the relationship between P300 and affective and psychotic symptoms in depressive disorder. METHODS: The P300 of 22 psychotropic drug-free depressed out-patients was registered within an auditory oddball paradigm. Affective and psychotic symptoms were evaluated using the depression and psychoticism subscales of SCL-90. The relationship of P300 amplitude and latency with affective and psychotic symptoms was assessed with multiple linear regression analysis and ANOVA. P300 values of the depressed patients were also compared with those of 22 healthy controls. RESULTS: Psychotic symptoms were associated with an overall reduction in P300 amplitude, which was pronounced in the left temporocentral electrode chain (T3, C3, Cz). Psychotic symptoms were also associated with a prolonged P300 latency. Affective symptoms were associated with a relational amplitude reduction at the right temporal scalp sites. There were no statistically significant differences in P300 amplitude or latency between depressed and control-subjects. LIMITATIONS: Rather small number of study subjects. The psychotic scores were low in all subjects. Multiple statistical analyses were used, and no specific a priori hypothesis was tested. CONCLUSIONS: In depressive disorder, affective and psychotic symptoms are associated with different types of P300 alteration, which may indicate different underlying neurobiological processes.     

Mood improvement reduces memory complaints in depressed patients

Background The aim was to examine associations between memory complaints, cognitive performance and mood in 174 adult, clinically depressed, neurologically healthy patients at baseline and during six months of follow-up. Methods Subjective memory disturbance was assessed using the Memory Complaint Questionnaire (MCQ). Levels of cognitive function, including memory, were assessed using a battery of neuropsychological tests. Mood and personality traits were assessed using rating scales, including the Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HDRS) and the 90-item Symptom Check List (SCL-90). Results At baseline, patients complaining of memory disturbances had higher BDI and HDRS scores than patients not complaining of memory problems. They also did less well in objective memory performances but not in other cognitive functions. Complaints of memory problems decreased during the follow-up. This change was associated with mood improvement and with reductions in other mental symptoms but not with changes in cognitive performance. In logistic regression analysis factors independently associated with MCQ change were age (OR 0.96) and BDI change (OR 1.06). Conclusions Subjective memory problems usually decline if depression is alleviated. Received: 3 February 2000 / Accepted: 26 October 2000     

Motor mechanisms of vertical fusion in individuals with superior oblique paresis.

PURPOSE: We wanted to determine the mechanisms of motor vertical fusion in patients with superior oblique paresis and to correlate these mechanisms with surgical outcomes. METHODS: Ten patients with superior oblique paresis underwent 3-axis, bilateral, scleral search coil eye movement recordings. Eye movements associated with fusion were analyzed. RESULTS: Six patients had decompensated congenital superior oblique paresis and 4 had acquired superior oblique paresis. All patients with acquired superior oblique paresis relied predominantly on the vertical rectus muscles for motor fusion. Patients with congenital superior oblique paresis were less uniform in their mechanisms for motor fusion: 2 patients used predominantly the oblique muscles, 2 patients used predominantly the vertical recti, and 2 patients used predominantly the superior oblique in the hyperdeviated eye and the superior rectus in the hypodeviated eye. The last 2 patients developed the largest changes in torsional eye alignment relative to changes in vertical eye alignment and were the only patients to develop symptomatic surgical overcorrections. CONCLUSION: There are 3 different mechanisms for vertical fusion in individuals with superior oblique paresis, with the predominant mechanism being the vertical recti. A subset of patients with superior oblique paresis uses predominantly the superior oblique muscle in the hyperdeviated paretic eye and the superior rectus muscle in the fellow eye for fusion. This results in intorsion of both eyes, causing a large change in torsional alignment. The consequent cyclodisparity, in addition to the existing vertical deviation, may make fusion difficult. The differing patterns of vertical fusional vergence may have implications for surgical treatment.     

Mycophenolate mofetil in patients with Crohn's disease

Objective: Intolerance to azathioprine is a rare but important problem in treating chronically active Crohn's disease. We performed this study to evaluate mycophenolate mofetil as an alternative immunosuppressive therapy for patients with Crohn's disease who did not tolerate azathioprine.
Methods: Four patients with highly active perianal Crohn's disease and two patients with chronically active, steroid-dependent Crohn's disease were included. All patients consumed 2 g/day of mycophenolate mofetil for a median of 8 months (range, 6–12 months). Disease activity was measured by the Perianal Crohn's Disease Activity Index in patients with perianal disease and by the Crohn's Disease Activity Index in patients with chronically active Crohn's disease.
Results: Azathioprine-induced side effects disappeared after the drug was discontinued. All patients improved during treatment with mycophenolate mofetil, as shown by a remarkable reduction in the respective clinical scores. Five patients showed no side effects during treatment with mycophenolate mofetil. After 4 months' treatment one patient developed diarrhea that was probably not due to mycophenolate mofetil.
Conclusions: Mycophenolate mofetil could be an alternative therapy to azathioprine in patients with Crohn's disease.     

Pandemic whole-virion,Vero-cell-derived,adjuvant-free influenza A H1N1 vaccine in patients with solid tumors and hematologic malignancies receiving concurrent anticancer treatment: Immunogenicity,tolerability, and acceptability during the pandemic situation

Patients with malignancies are considered to be at increased risk of acquiring influenza. Because of higher complication and case fatality rates, preventive measures such as vaccination are of great interest. The objective of this study was to assess the acceptability, tolerability and immunogenicity of an adjuvant-free whole-virion pandemic influenza A (H1N1) vaccine in cancer patients with ongoing anticancer treatment during a ‘pandemic situation’. Adult patients with hematologic malignancies or solid tumors and concurrent cytotoxic, targeted, and/or hormone therapy were recruited during the influenza A (H1N1) pandemic in 2009/2010 and were offered free vaccine. Antibody titers were measured using virus-specific hemagglutination inhibition assay and ELISA. Among 285 patients with solid tumors who were offered vaccination during their therapy, 260 (91.2%) declined and 25 (8.8%) accepted. Seventeen patients with hematologic malignancies were also vaccinated during therapy; 23 healthy individuals served as a control group. When measured using hemagglutination-inhibition assays, rates of seroprotection, seroconversion, and geometric mean titer ratios after the second vaccination were 96%, 70%, and 4.1 respectively among the healthy individuals, 90%, 52%, and 4.3 among patients with solid tumors, and 67%, 13%, and 1.5 among patients with hematologic malignancies during therapy (P < 0.05). When measured using ELISA, seropositivity differed significantly among the three groups after the second vaccination: healthy individuals 74%, patients with solid tumors 57%, those with hematologic malignancies 13% (P < 0.001). The vaccine was well tolerated. Our results demonstrate a low uptake of the well tolerated adjuvant-free influenza A (H1N1) vaccine by cancer patients receiving anticancer treatment during the pandemic of 2009/2010. Among the vaccinated patients, the immune response was weaker than that in healthy individuals. The immune response in patients with hematological malignancies was low. Two doses of vaccine are needed in these immunosuppressed patients.     

Temporal cortex dopamine D2/3 receptor binding in major depression

The aim of this study was to assess the dopamine function of the temporal cortex in major depressive disorder using [¹²³I]epidepride to image D_2/3 receptor binding sites. Ten major depressives and 10 healthy controls were selected from a general population sample for single-photon emission computed tomography imaging. Among the major depressives there was a strong bilateral correlation between the scores on the 21-item Hamilton Depression Rating Scale and D_2/3 receptor binding. Dopaminergic abnormalities may be present in the temporal cortices of major depressives.     

Aquaporin-1 and HCO3−-Cl− transporter-mediated transport of CO2 across the human erythrocyte membrane

Recent studies have suggested that aquaporin-1 (AQP1) as well as the HCO₃⁻-Cl⁻ transporter may be involved in CO₂ transport across biological membranes, but the physiological importance of this route of gas transport remained unknown. We studied CO₂ transport in human red blood cell ghosts at physiological temperatures (37 °C). Replacement of inert with CO₂-containing gas above a stirred cell suspension caused an outside-to-inside directed CO₂ gradient and generated a rapid biphasic intracellular acidification. The gradient of the acidifying gas was kept small to favour high affinity entry of CO₂ passing the membrane. All rates of acidification except that of the approach to physicochemical equilibrium of the uncatalysed reaction were restricted to the intracellular environment. Inhibition of carbonic anhydrase (CA) demonstrated that CO₂-induced acidification required the catalytic activity of CA. Blockade of the function of either AQP1 (by HgCl₂ at 65 μM) or the HCO₃⁻-Cl⁻ transporter (by DIDS at 15 μM) completely prevented fast acidification. These data indicate that, at low chemical gradients for CO₂, nearly the entire CO₂ transport across the red cell membrane is mediated by AQP1 and the HCO₃⁻-Cl⁻ transporter. Therefore, these proteins may function as high affinity sites for CO₂ transport across the erythrocyte membrane.     

Sequential changes of noradrenaline content of vein grafts in rats: quantitative estimation by high-performance liquid chromatography using electrochemical detection

Supradiaphragmatic inferior vena cava was transplanted end-to-end into the abdominal aorta of 11-week-old rats of the same inbred strain and same litter using microvascular technique. The grafts were removed 3 days, 4, 8, 16, and 35 weeks postoperatively, and their noradrenaline (NA) content was estimated by high-performance liquid chromatography using electrochemical detection. The amount of NA was significantly lower (P less than .001) in all vein grafts as compared to nontransplanted vena cava. The substantial decrease of NA in the vein grafts throughout the observation period indicates a persistent denervation of the transplant.