[Guideline-conform exact diagnosis and coding of dementia]. / Leitliniengerechte exakte Diagnose und Codierung der Demenz.

All of the currently available guidelines specify a two-stage procedure. The first stage entails performing a comprehensive description, diagnosis and confirmation of the dementia syndrome. The second stage involves the precise etiological classification. Alzheimer's disease represents the most common cause followed by vascular dementia and Parkinson's disease dementia, Lewy body dementia, frontotemporal lobar degeneration and others. Dementia encompasses a variety of underlying conditions. This review gives an overview of the clinically oriented diagnosis according to the updated S3 guidelines in Germany.

Evidence of endogenous volatile organic compounds as biomarkers of diseases in alveolar breath.

The effect of oxygen on markers of oxidative stress has been partially elucidated. Volatile organic compounds (VOCs) are created during the oxidative burst and excreted in the human alveolar breath, which indeed contains biomarkers. A general concept including collection, separation, detection and clinical biomakers validation is presented in this article: (i) a method for the collection and GC-MS of halogenated VOCs in human alveolar breath is described: a transportable apparatus which sampled specifically alveolar breath; the VOCs were captured in a thermal desorption tube, Carbotrap 200® and each sample was thermally desorbed from the trap in an automated GC-MS apparatus; (ii) the inhibitory effects of halogenated alkanes on mitochondria are suspected likely to fight against oxidative stress deleterious reactions; (iii) two-dimensional gas chromatography occurs by the repeated and re-injection of effluent from one chromatographic column into a second column of orthogonal phase. A new commercial GCxGC system is presented; it is accomplished with a dual-stage, quad-jet thermal modulator positioned between the two columns; (iv) the affinity-based sensors usually used in connection with the GCxGC system face a difficulty to take into account different biases coming from different sources of drifting. Compared to other affinity-based sensing modes like electrical ones, gravimetric sensors enable a better decoupling. Nano Electro Mechanical Systems (NEMS)-based resonators are a particular type of gravimetric gas sensors. They are coated with a sensitive layer of polymer where gases of interest present in the atmosphere adsorb, generating an additional mass load which is measured through a frequency shift; (v) examination of exhaled breath has the potential to change the existing routine approaches in human medicine. Breath sampling to identify volatile biomarkers in diseases has been proposed in several respiratory diseases. Several VOCs have been identified in these patients by GC-MS. However, the use of traditional analytical instruments such as GC-MS to detect biomarkers of diseases has not become a routine for clinical applications. Consequently the electronic nose was the logical instrument of choice for disease diagnosis due to the capability of identifying complex mixtures of VOCs (as a whole) within sampled air using pattern-recognition algorithms.

Targeting of c-kit+ haematopoietic progenitor cells prevents hypoxic pulmonary hypertension.

Haematopoietic c-kit+ progenitor cells may contribute to pulmonary vascular remodelling and pulmonary hypertension (PH). Stromal derived factor-1 (SDF-1/CXCL12) and its receptors CXCR4 and CXCR7 have been shown to be critical for homing and mobilisation of haematopoietic c-kit+ progenitor cells in the perivascular niche. We administered AMD3100, a CXCR4 antagonist, and CCX771, a CXCR7 antagonist, to chronic hypoxia exposed mice in order to study the role of c-kit+ progenitor cells in PH. CXCL12, CXCR4 and CXCR7 protein expression, haemodynamic parameters, right ventricular mass, extent of vascular remodelling and perivascular progenitor cell accumulation were studied. Chronic hypoxia-exposed mice showed increased total lung tissue expression of CXCR4, CXCR7 and CXCL12 after development of PH. This was associated with significantly increased right ventricular systolic pressure and evidence of right ventricular hypertrophy, vascular remodelling and perivascular c-kit+/sca-1+ progenitor cell accumulation. CCX771 administration did not abrogate these effects. In contrast, administration of AMD3100, whether alone or combined with CCX771, prevented vascular remodelling, PH and perivascular accumulation of c-kit+/sca-1+ progenitor cells, with a synergistic effect of these agents. This study offers important pathophysiological insights into the role of haematopoietic c-kit+ progenitors in hypoxia-induced vascular remodelling and may have therapeutic implications for PH.

Investigating sacroplasty: technical considerations and finite element analysis of polymethylmethacrylate infusion into cadaveric sacrum.

BACKGROUND AND PURPOSE: Sacroplasty is not as routinely performed as vertebroplasty, possibly due to technical challenges and the paucity of data regarding subsequent outcomes. The first goal of the present investigation was to describe a technique for sacroplasty that facilitates safe needle placement and polymethylmethacrylate (PMMA) extrusion. The second goal was to perform finite element analysis (FEA) by using a geometric model of sacral fracture to identify mechanical outcomes of sacroplasty. MATERIALS AND METHODS: Sacroplasty was performed on fresh pelvis specimens (n=4) under biplane fluoroscopy. Cadavers were imaged via CT before and after sacroplasty and volume rendered to examine needle placement and PMMA extrusion. The volume-rendered CT data were then used to generate geometric models of the intact, fractured, and cement-augmented fractured sacrum for comparison by using FEA. RESULTS: CT data demonstrate that safe injection needle placement and PMMA delivery may be facilitated by orienting the needle parallel to the L5-S1 interspace and ipsilateral sacroiliac joint, then targeting the superolateral sacral ala within an area bounded by a line lateral to the posterior foraminal openings and a line superimposed on the medial edge of the sacroiliac joint. FEA revealed that simulated sacroplasty decreased maximal principal stress at the point of sacral fracture propagation by 83% and fracture gap micromotion by 48%. CONCLUSION: Sacral landmarks can be used to place PMMA safely where sacral fractures occur. FEA suggests that sacroplasty may decrease fracture-associated mechanical stress and micromotion, which may contribute to patient reports of decreased pain and increased mobility postsacroplasty.

Radioiodinated Capsids Facilitate In Vivo Non-Invasive Tracking of Adeno-Associated Gene Transfer Vectors.

Viral vector mediated gene therapy has become commonplace in clinical trials for a wide range of inherited disorders. Successful gene transfer depends on a number of factors, of which tissue tropism is among the most important. To date, definitive mapping of the spatial and temporal distribution of viral vectors in vivo has generally required postmortem examination of tissue. Here we present two methods for radiolabeling adeno-associated virus (AAV), one of the most commonly used viral vectors for gene therapy trials, and demonstrate their potential usefulness in the development of surrogate markers for vector delivery during the first week after administration. Specifically, we labeled adeno-associated virus serotype 10 expressing the coding sequences for the CLN2 gene implicated in late infantile neuronal ceroid lipofuscinosis with iodine-124. Using direct (Iodogen) and indirect (modified Bolton-Hunter) methods, we observed the vector in the murine brain for up to one week using positron emission tomography. Capsid radioiodination of viral vectors enables non-invasive, whole body, in vivo evaluation of spatial and temporal vector distribution that should inform methods for efficacious gene therapy over a broad range of applications.

Brain Region-Specific Degeneration with Disease Progression in Late Infantile Neuronal Ceroid Lipofuscinosis (CLN2 Disease).

BACKGROUND AND PURPOSE: Late infantile neuronal ceroid lipofuscinosis (CLN2 disease) is a uniformly fatal lysosomal storage disease resulting from mutations in the CLN2 gene. Our hypothesis was that regional analysis of cortical brain degeneration may identify brain regions that are affected earliest and most severely by the disease. MATERIALS AND METHODS: Fifty-two high-resolution 3T MR imaging datasets were prospectively acquired on 38 subjects with CLN2. A retrospective cohort of 52 disease-free children served as a control population. The FreeSurfer software suite was used for calculation of cortical thickness. RESULTS: An increased rate of global cortical thinning in CLN2 versus control subjects was the primary finding in this study. Three distinct patterns were observed across brain regions. In the first, subjects with CLN2 exhibited differing rates of cortical thinning versus age. This was true in 22 and 26 of 34 regions in the left and right hemispheres, respectively, and was also clearly discernable when considering brain lobes as a whole and Brodmann regions. The second pattern exhibited a difference in thickness from healthy controls but with no discernable change with age (9 left hemispheres, 5 right hemispheres). In the third pattern, there was no difference in either the rate of cortical thinning or the mean cortical thickness between groups (3 left hemispheres, 3 right hemispheres). CONCLUSIONS: This study demonstrates that CLN2 causes differential rates of degeneration across the brain. Anatomic and functional regions that degenerate sooner and more severely than others compared with those in healthy controls may offer targets for directed therapies. The information gained may also provide neurobiologic insights regarding the mechanisms underlying disease progression.

Reduction of thioredoxin significantly decreases its partial specific volume and adiabatic compressibility.

The partial specific volume and adiabatic compressibility were determined at several temperatures for oxidized and reduced Escherichia coli thioredoxin. Oxidized thioredoxin had a partial specific volume of 0.785-0.809 mL/g at the observed upper limit for all proteins whereas the partial specific volume of reduced thioredoxin was 0.745-0.755 mL/g, a value in the range found for a majority of proteins. The adiabatic compressibility of oxidized thioredoxin was also much larger (9.8-18 x 10(-12) cm2 dyne-1) than that of the reduced protein (3.8-7.3 x 10(-12)). Apart from the region immediately around the small disulfide loop, the structures of the oxidized (X-ray, crystal) and reduced protein (nuclear magnetic resonance, solution) are reported to be very similar. It would appear that alterations in the solvent layer in contact with the protein surface must play a major role in producing these large changes in the apparent specific volumes and compressibilities in this system. Some activities of thioredoxin require the reduced structure but are not electron transfer reactions. The large changes in physical parameters reported here suggest the possibility of a reversible metabolic control function for the SS bond.

Differences in hydrogen exchange behavior between the oxidized and reduced forms of Escherichia coli thioredoxin.

Amide proton exchange of thioredoxin is used to monitor the structural effects of reduction of its single disulfide. An effective 3-5-proton difference between the oxidized and reduced protein form is observed early in proton out-exchange of the whole protein, which is independent of temperature in the range of 5-45 degrees C, indicating that redox-sensitive changes are probably not due to low-energy structural fluctuations. Medium resolution hydrogen exchange experiments have localized the redox-sensitive amide protons to two parts of the sequence that are distant from each other in the three-dimensional structure: the active-site turn and the first beta-strand. The sum of the proton differences observed in the peptides from these regions is equal to that of the whole protein, indicating that all redox-sensitive hydrogen exchange effects are observed in the peptide experiments. A model combining structural changes within the protein matrix with changes in the surface hydration properties is proposed as a mechanism for the communication between distant sites within the protein. Sound velocity and density measurements of reduced and oxidized thioredoxin are presented in the accompanying paper (Kaminsky, S.M. & Richards, F.M., 1992, Protein Sci. 1, 22-30).

Feasibility of gene therapy for late neuronal ceroid lipofuscinosis.

Late infantile neuronal ceroid lipofuscinosis is a progressive childhood neurodegenerative disorder characterized by intracellular accumulation of autofluorescent material resembling lipofuscin in neuronal cells. This report summarizes the new therapies under consideration for late infantile neuronal ceroid lipofuscinosis, with a focus on strategies for in vivo gene therapy for the retinal and central nervous system manifestations of the disease.

Cellular aspects of myasthenia gravis.

Several cellular aspects were investigated in a large series of patients with MG. First, non-Ag-specific proliferation was tested by measuring the response to r-IL2. Thymocytes from most MG patients showed hyperactivity to r-IL2. Peripheral blood lymphocytes (PBL) from some patients also showed a high response to r-IL2. These responding patients were generally those tested before thymectomy, presenting a high anti-AChR Ab titer and a severe form of the disease. Second, Ag-specific proliferation of MG PBL was assayed using 8 synthetic peptides corresponding to selected domains of torpedo or human AChR. Only 2 peptides gave a positive response in a significant number of patients, essentially in those presenting high anti-AChR Ab titer. The first is located near the alpha-bungarotoxin binding site and the second is in a cytoplasmic domain, according to models predicting the AChR transmembrane orientation. The positive results were essentially obtained with the human peptides; the corresponding torpedo peptides were positive in very few patients. Both human and torpedo peptides which include a part of the alpha-bungarotoxin binding site were negative. Finally, although morphological abnormalities were clearly visible in thymic hyperplasia, no correlation could be established between the thymus type and the cellular proliferation either to r-IL2, or to the peptides. Overall, our data indicate that cell-dependent mechanisms participate in the pathogenesis of MG, but the level of their involvement deserves further investigation.

Evidence of enhanced recombinant interleukin-2 sensitivity in thymic lymphocytes from patients with myasthenia gravis: possible role in autoimmune pathogenesis.

We evaluated the activation state of thymic lymphocytes in patients with myasthenia gravis (MG) by cytofluorographic analysis of CD25 expression and by testing their sensitivity to recombinant interleukin-2 (rIL-2) in the absence of any known previous stimulation. We detected no phenotypic signs of activation in fresh MG thymic lymphocyte suspensions, while functional signs of activation were reflected in a significantly higher sensitivity to rIL-2 in MG patients than in controls. The responses to rIL-2 were time- and dose-dependent, were inhibited by a blocking anti-IL-2 receptor antibody, and were associated with an increase in CD25+ T cells in both patients and controls. The T cells with functional signs of previous activation may represent autoreactive cells involved in the autoimmune process and confirm thymus gland hyperactivity in MG. These cells could result from primary autosensitization against the thymic acetylcholine receptor (AChR)-like molecule or from altered migration of peripheral activated cells into an abnormal thymic environment. Our results also provide a clue for understanding the effect of thymectomy in myasthenia gravis.

Antibodies to thymic epithelial cells in myasthenia gravis.

The presence of anti-thymus antibodies was investigated in the serum of 36 patients with myasthenia gravis (MG). Using an immunofluorescence technique on frozen thymic sections, we found 45% of patients sera reacting with normal or MG thymuses. Staining was confined to subcapsular and medullary keratin-positive epithelial cells. Thirty-five out of 36 sera from healthy controls and all 15 sera from patients presenting another autoimmune disorder were negative. Antibodies to thymic epithelial cells were almost exclusively detected in patients presenting thymic hyperplasia and did not disappear after thymectomy. They were not clearly associated with antiacetylcholine receptor antibody titer, nor with disease severity. Their strong association to thymic abnormalities highlights the role of the thymus in pathogenesis of MG. The reasons for the appearance of these antibodies, the structure they recognize on thymic epithelial cells and their possible etiological role are discussed.

In vivo preferential usage of TCR V beta 8 in Torpedo acetylcholine receptor immune response in the murine experimental model of myasthenia gravis.

The aim of our study was to determine the T cell receptor (TCR) V beta gene usage involved in the T cell response to Torpedo AChR in C57BL/6 mice. The specific proliferation towards AChR was found to be blocked by anti-V beta 8.1,2,3 and to a lesser extent by anti-V beta 5 mAbs, but not by the other antibodies used (anti-V beta 2, V beta 6, V beta 9). In addition, a significant expansion of CD4+ V beta 8+ cells was observed when lymph node cells from these primed mice were stimulated in vitro with purified AChR. Involvement of V beta 8 subfamilies was also explored in vivo. After 7 days of treatment, there was a striking inhibition of the proliferative response of cells from anti-V beta 8.1,2,3-treated mice and a moderate inhibition when using anti-V beta 8.1,2 and anti-V beta 8.2 antibodies. Thus our in vitro and in vivo analysis indicate that in C57Bl/6 mice, T cell response to AChR is restricted to few V beta TCR, mostly belonging to the V beta 8 sub-families.

Identification by genomic typing of non-DR3 HLA class II genes associated with myasthenia gravis.

HLA association with myasthenia gravis (MG) has been studied in a series of 114 patients using class I and class II genotyping after PCR amplification. Positive association was found with DR3, particularly in women (RR = 2.6) and in early MG onset (RR = 3.4). DRB1, DRB3, DQB1, DQA1 and B (B8 and B18) genotyping revealed that the association was predominantly with the B8 DRB1*03 DRB3*0101 DQB1*0201 DQA1*0501 ancestral haplotype. This haplotype frequency was also increased in patients with thymic hyperplasia (RR = 3.5) and was greatly reduced in patients with thymoma (RR = 0.35). Sixteen out of 48 patients carrying this 8.1 ancestral haplotype showed absence of B8 (n = 4) or of DR3 (n = 12). HLA class II genotyping further revealed the existence of two other significant associations. MG was positively associated with the DQB1*0604 allele (RR = 3.4), particularly in patients with thymoma (RR = 5.7). Furthermore, the disease was negatively associated with DR1 in females (RR = 0.32). These data suggest that MG is placed under the control of at least three distinct genes: (1) a class II predisposing gene in the 8.1 ancestral haplotype; (2) a thymoma-associated class II allele on the DQB1*0604 haplotype; and (3) a protective allele DR1.

Evaluation of a lipopeptide immunogen as a therapeutic in HIV type 1-seropositive individuals.

A 32-amino acid HIV-1 Gag immunogen was assessed for its ability to augment existing virus-specific CTL responses in chronically HIV-1-infected individuals. The immunogen was an HIV-1 synthetic lipopeptide conjugate composed of an N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2R)-propyl-N-(R)-cysteinyl] group covalently coupled to a synthetic 32-amino acid Gag peptide containing at least 5 CTL epitopes known to be restricted by HLA-A33, -B8, -B27, -B35, and -Bw62. This potential immunotherapeutic was first determined to be safe in six HIV-1-seropositive subjects, with no adverse clinical effects noted during a 182-day period after administration of a dose of 350 microg. The immunogenicity of this lipopeptide conjugate was then assessed in a pilot study in nine HIV-1-seropositive volunteers with peripheral blood CD4+ lymphocyte counts of >500/microl. Three groups of individuals were studied: HLA-selected subjects who received 350 microg of the immunogen on days 0, 28, and 56 (four subjects); HLA-selected subjects who received a placebo according to a similar inoculation schedule (three subjects); and HLA-mismatched subjects who received the experimental immunogen (two subjects). All subjects were monitored for 26 weeks. After treatment, PBLs from two of the four HLA-selected subjects who received the experimental immunogen showed a transient increase in Gag peptide-specific bulk CTL activity. None of the placebo-vaccinated or vaccinated HLA-mismatched subjects showed any change in bulk Gag peptide-specific CTL activity. However, no consistent decrease in plasma HIV-1 RNA levels was noted in any of the subjects. The present study illustrates that this peptide formulation may not be a sufficiently potent immunogen to significantly augment HIV-1-specific CTLs and to decrease virus load in HIV-1-seropositive individuals.

In situ production of interleukins in hyperplastic thymus from myasthenia gravis patients.

We analyzed by in situ hybridization the expression of four interleukin genes (interleukin-beta [IL-1 beta], IL-6, IL-2, and interferon-gamma) in seven thymuses displaying a follicular hyperplasia. The seven thymuses were obtained from patients with myasthenia gravis. Interleukin-1 beta- and IL-6-producing cells were detected in similar amounts and with similar distributions: mainly in perifollicular areas and in the connective structures emerging from the septae at the site of cortex disruption. The comparison of in situ hybridization and immunohistochemical results suggested that thymic epithelial cells and/or perifollicular macrophages were responsible for this production. Interleukin-2-producing cells were detected in perifollicular areas and, to a lesser extent, inside follicles. They were clearly outnumbered by CD25-positive cells which were similarly distributed. Despite the expression of these molecular and immunohistochemical markers of T-cell activation, interferon-gamma-producing cells were extremely rare in myasthenic thymuses. The pattern of interleukin production (which was virtually absent in normal control thymuses) in myasthenic thymuses was different from that in benign hyperplastic lymph nodes. This interleukin production may play a role in the development of follicular hyperplasia in myasthenic thymuses, a phenomenon which is associated with the in situ production of autoantibodies.

Antivector and antitransgene host responses in gene therapy.

Current viral gene therapy vectors effectively transfer genes in vivo at the price of eliciting innate and acquired host responses against the vector and/or transgene. Antigens present in the viral vector and the expression of the transgene both cause cellular and humoral immune responses dependent on the viral vector, the route of administration, and the genotype and infection history of the host. In general, adenoviral vectors cause strong immune responses, which result in only transient expression of the therapeutic gene. Adeno-associated virus and retrovirus vectors elicit weaker immune responses and can therefore result in long-term gene transfer and expression. Methods to avoid host responses, including modification of viral vector and immunosuppression of the host, can increase the longevity and efficiency of gene transfer.

Amniocentesis for selection before rescue cerclage.

OBJECTIVE: To determine whether diagnostic amniocentesis should be part of evaluations of women under consideration for rescue cerclage. METHODS: We reviewed the obstetric records of 25 candidates for rescue cerclage seen between June 30, 1995, and July 1, 1997. Rescue cerclage was defined as a procedure on a cervix with an internal os dilated at least 2 cm and 50% effaced, with membranes visible at the external os. Transabdominal amniocentesis was offered as part of the preoperative evaluation, and amniotic fluid (AF) was sent for glucose and lactate dehydrogenase level determinations, Gram staining, and culture for aerobic and anaerobic bacteria. Placentas were examined for histopathologic evidence of inflammation. The women were divided into three groups. Eleven women had rescue cerclage after amniocentesis, seven had rescue cerclage after declining amniocentesis, and seven had amniocentesis but were treated conservatively because of AF markers of infection. Analysis of variance and chi(2) statistics were used. RESULTS: The group that had rescue cerclage after amniocentesis had a significantly longer mean admission-to-delivery interval, higher mean gestational age at delivery, higher mean birth weight, and higher neonatal survival rate than did the group that had rescue cerclage without amniocentesis and the group that had no cerclage after amniocentesis (P <.001). CONCLUSION: Amniocentesis before rescue cerclage placement identified women with subclinical chorioamnionitis who would not benefit from cerclage.