What Do We Know So Far About Ventricular Arrhythmias and Sudden Cardiac Death Prediction in the Mitral Valve Prolapse Population? Could Biomarkers Help Us Predict Their Occurrence?

PURPOSE OF THE REVIEW: To summarize currently available data on the topic of mitral valve prolapse (MVP) and its correlation to the occurrence of atrial and ventricular arrhythmias. To assess the prognostic value of several diagnostic methods such as transthoracic echocardiography, transesophageal echocardiography, cardiac magnetic resonance, cardiac computed tomography, electrocardiography, and electrophysiology concerning arrhythmic episodes. To explore intra and extracellular biochemistry of the cardiovascular system and its biomarkers as diagnostic tools to predict rhythm disturbances in the MVP population. RECENT FINDINGS: MVP is a common and mainly benign valvular disorder. It affects 2-3% of the general population. MVP is a heterogeneous and highly variable phenomenon with three structural phenotypes: myxomatous degeneration, fibroelastic deficiency, and forme fruste. Exercise intolerance, supraventricular tachycardia, and chest discomfort are the symptoms that are often paired with psychosomatic components. Though MVP is thought to be benign, the association between isolated MVP without mitral regurgitation (MR) or left ventricle dysfunction, with ventricular arrhythmia (VA) and sudden cardiac death (SCD) has been observed. The incidence of SCD in the MVP population is around 0.6% per year, which is 6 times higher than the occurrence of SCD in the general population. Often asymptomatic MVP population poses a challenge to screen for VA and prevent SCD. Therefore, it is crucial to carefully assess the risk of VA and SCD in patients with MVP with the use of various tools such as diagnostic imaging and biochemical and genetic screening.

Phylogeny and species delimitation of Strobilomyces (Boletaceae), with an emphasis on the Asian species.

Strobilomyces is broadly distributed geographically and serves an important ecological function. However, it has been difficult to delimit species within the genus, primarily due to developmental variations and phenotypic plasticity. To elucidate phylogenetic relationships among species within the genus and to understand its species diversity, especially in Asia, materials of the genus collected from five continents (Africa, Asia, Australia, Europe, and North/Central America) were investigated. The phylogeny of Strobilomyces was reconstructed based on nucleotide sequences of four genes coding for: the largest and the second largest subunits of the RNA polymerase II (RPB1 and RPB2); the translation elongation factor subunit 1-α (TEF1); and the mitochondrial cytochrome oxidase subunit 3 (COX3). The combined results based on molecular phylogenetics, morphological characters, host tree associations, and geographical distribution patterns support a new classification consisting of two sections, sect. Strobilomyces and sect. Echinati. Using the genealogical concordance phylogenetic species recognition (GCPSR) approach, at least 33 phylogenetic species in Asia can be delimited, all of which are supported by morphological features, and five phylogenetic species remain to be described. The mountainous region of Southwest China is especially special, containing at least 21 species and likely represents a centre of diversification. We further compared our specimens with the type specimens of 25 species of Strobilomyces. Our comparisons suggest that, there are a total of 31 distinct species, while S. sanmingensis, S. verruculosus, S. subnigricans, and S. zangii/S. areolatus, are synonyms of S. mirandus, S. giganteus, S. alpinus and S. seminudus, respectively. Eight new species, namely, S. albidus, S. anthracinus, S. calidus, S. cingulatus, S. densisquamosus, S. douformis, S. microreticulatus and S. pinophilus, are described. A dichotomous key to the Asian Strobilomyces species is provided.

An approach to the asthma-protective farm effect by geocoding: Good farms and better farms.

BACKGROUND: The highly consistent association of growing up on a farm with a reduced asthma risk has so far been attributed to direct farm exposure. In contrast, geographic determinants of the larger environment have never been assessed. In this study, the effects of proximity to farms and environmental variables in relation to the residential address on asthma and atopy were assessed. METHODS: Addresses of 2265 children of the Bavarian arm of the GABRIELA study were converted into geocodes. Proximity to the nearest cow farm was calculated, and environmental characteristics were derived from satellite data or terrestrial monitoring. Bacterial diversity in mattress dust samples was assessed in 501 children by sequencing of the 16S rRNA amplicons. Logistic regression models were used to calculate associations between outcomes and exposure variables. RESULTS: Asthma and atopy were inversely associated with the presence of a farm within a radius of maximum 100 m. The environmental variables greenness, tree cover, soil sealing, altitude, air pollution differed not only between farm and non-farm children but also between farm children with and without another farm nearby. The latter distinction revealed strong associations with characteristics of traditional farms including a broader diversity of microbial exposure, which mainly contributed to the protective effect on asthma. In non-farm children, the protective effect of a farm nearby was completely explained by consumption of farm milk. CONCLUSIONS: Clustering of farms within a neighborhood of 100 m is strongly associated with the protective effect on asthma and may represent a more traditional style of farming with broader microbial exposure.

Environmental and mucosal microbiota and their role in childhood asthma.

BACKGROUND: High microbial diversity in the environment has been associated with lower asthma risk, particularly in children exposed to farming. It remains unclear whether this effect operates through an altered microbiome of the mucosal surfaces of the airways. METHODS: DNA from mattress dust and nasal samples of 86 school age children was analyzed by 454 pyrosequencing of the 16S rRNA gene fragments. Based on operational taxonomic units (OTUs), bacterial diversity and composition were related to farm exposure and asthma status. RESULTS: Farm exposure was positively associated with bacterial diversity in mattress dust samples as determined by richness (P = 8.1 × 10-6 ) and Shannon index (P = 1.3 × 10-5 ). Despite considerable agreement of richness between mattress and nasal samples, the association of richness with farming in nasal samples was restricted to a high gradient of farm exposure, that is, exposure to cows and straw vs no exposure at all. In mattress dust, the genera Clostridium, Facklamia, an unclassified genus within the family of Ruminococcaceae, and six OTUs were positively associated with farming. Asthma was inversely associated with richness [aOR = 0.48 (0.22-1.02)] and Shannon index [aOR = 0.41 (0.21-0.83)] in mattress dust and to a lower extent in nasal samples [richness aOR 0.63 = (0.38-1.06), Shannon index aOR = 0.66 (0.39-1.12)]. CONCLUSION: The stronger inverse association of asthma with bacterial diversity in mattress dust as compared to nasal samples suggests microbial involvement beyond mere colonization of the upper airways. Whether inhalation of metabolites of environmental bacteria contributes to this phenomenon should be the focus of future research.

Asthma and allergies: is the farming environment (still) protective in Poland? The GABRIEL Advanced Studies.

BACKGROUND: Evidence exists that a farming environment in childhood may provide protection against atopic respiratory disease. In the GABRIEL project based in Poland and Alpine regions of Germany, Austria and Switzerland, we aimed to assess whether a farming environment in childhood is protective against allergic diseases in Poland and whether specific exposures explain any protective effect. METHODS: In rural Poland, 23 331 families of schoolchildren completed a questionnaire enquiring into farming practices and allergic diseases (Phase I). A subsample (n = 2586) participated in Phase II involving a more detailed questionnaire on specific farm exposures with objective measures of atopy. RESULTS: Farming differed between Poland and the Alpine centres; in the latter, cattle farming was prevalent, whereas in Poland 18% of village farms kept ≥1 cow and 34% kept ≥1 pig. Polish children in villages had lower prevalences of asthma and hay fever than children from towns, and in the Phase II population, farm children had a reduced risk of atopy measured by IgE (aOR = 0.72, 95% CI 0.57, 0.91) and skin prick test (aOR = 0.65, 95% CI 0.50, 0.86). Early-life contact with grain was inversely related to the risk of atopy measured by IgE (aOR = 0.66, 95% CI 0.47, 0.92) and appeared to explain part of the farming effect. CONCLUSION: While farming in Poland differed from that in the Alpine areas as did the exposure-response associations, we found in communities engaged in small-scale, mixed farming, there was a protective farming effect against objective measures of atopy potentially related to contact with grain or associated farm activities.

Genome-wide association study of body mass index in 23 000 individuals with and without asthma.

BACKGROUND: Both asthma and obesity are complex disorders that are influenced by environmental and genetic factors. Shared genetic factors between asthma and obesity have been proposed to partly explain epidemiological findings of co-morbidity between these conditions. OBJECTIVE: To identify genetic variants that are associated with body mass index (BMI) in asthmatic children and adults, and to evaluate if there are differences between the genetics of BMI in asthmatics and healthy individuals. METHODS: In total, 19 studies contributed with genome-wide analysis study (GWAS) data from more than 23 000 individuals with predominantly European descent, of whom 8165 are asthmatics. RESULTS: We report associations between several DENND1B variants (P = 2.2 × 10(-7) for rs4915551) on chromosome 1q31 and BMI from a meta-analysis of GWAS data using 2691 asthmatic children (screening data). The top DENND1B single nucleotide polymorphisms(SNPs) were next evaluated in seven independent replication data sets comprising 2014 asthmatics, and rs4915551 was nominally replicated (P < 0.05) in two of the seven studies and of borderline significance in one (P = 0.059). However, strong evidence of effect heterogeneity was observed and overall, the association between rs4915551 and BMI was not significant in the total replication data set, P = 0.71. Using a random effects model, BMI was overall estimated to increase by 0.30 kg/m(2) (P = 0.01 for combined screening and replication data sets, N = 4705) per additional G allele of this DENND1BSNP. FTO was confirmed as an important gene for adult and childhood BMI regardless of asthma status. CONCLUSIONS AND CLINICAL RELEVANCE: DENND1B was recently identified as an asthma susceptibility gene in a GWAS on children, and here, we find evidence that DENND1B variants may also be associated with BMI in asthmatic children. However, the association was overall not replicated in the independent data sets and the heterogeneous effect of DENND1B points to complex associations with the studied diseases that deserve further study.

[Diagnostics of primary ciliary dyskinesia]. / Diagnostik der primären Ziliendyskinesie.

Primary ciliary dyskinesia (PCD) is an autosomal recessive inherited disease characterized by abnormal ciliary motion and impaired mucociliary clearance. The prevalence of PCD is approximately 1 : 15 000 - 1 : 20 000 in live births. Cilia dysfunction is also implicated in a wider spectrum of diseases due to impaired organ genesis and body symmetry. Cilia are highly conserved in animals and show complex structures containing more than 250 proteins for their formation. Recent studies have begun to locate the PCD genes in the genome and characterize functional mutations. Specific diagnosis of the ciliary dysfunction requires physiological measurements as well as light- and electron microscopy. Abnormalities in ciliary motion and ultrastructural studies can be performed with nasal mucosal epithelium.

Targeting ErbB2 and ErbB3 with a bispecific single-chain Fv enhances targeting selectivity and induces a therapeutic effect in vitro.

Inappropriate signalling through the EGFR and ErbB2/HER2 members of the epidermal growth factor family of receptor tyrosine kinases is well recognised as being causally linked to a variety of cancers. Consequently, monoclonal antibodies specific for these receptors have become increasingly important components of effective treatment strategies for cancer. Increasing evidence suggests that ErbB3 plays a critical role in cancer progression and resistance to therapy. We hypothesised that co-targeting the preferred ErbB2/ErbB3 heterodimer with a bispecific single-chain Fv (bs-scFv) antibody would promote increased targeting selectivity over antibodies specific for a single tumour-associated antigen (TAA). In addition, we hypothesised that targeting this important heterodimer could induce a therapeutic effect. Here, we describe the construction and evaluation of the A5-linker-ML3.9 bs-scFv (ALM), an anti-ErbB3/ErbB2 bs-scFv. The A5-linker-ML3.9 bs-scFv exhibits selective targeting of tumour cells in vitro and in vivo that co-express the two target antigens over tumour cells that express only one target antigen or normal cells that express low levels of both antigens. The A5-linker-ML3.9 bs-scFv also exhibits significantly greater in vivo targeting of ErbB2'+'/ErbB3'+' tumours than derivative molecules that contain only one functional arm targeting ErbB2 or ErbB3. Binding of ALM to ErbB2'+'/ErbB3'+' cells mediates inhibition of tumour cell growth in vitro by effectively targeting the therapeutic anti-ErbB3 A5 scFv. This suggests both that ALM could provide the basis for an effective therapeutic agent and that engineered antibodies selected to co-target critical functional pairs of TAAs can enhance the targeting specificity and efficacy of antibody-based cancer therapeutics.

Living at high altitude and risk of hospitalisation for atopic asthma in children: results from a large prospective birth-cohort study.

BACKGROUND: Asthma is among the most common chronic diseases in childhood and is steadily increasing in prevalence. Better characterisation of factors that determine the risk of hospitalisation for atopic asthma in childhood may help design prevention programmes and improve our understanding of disease pathobiology. This study will focus on the altitude of residence. METHODS: This is an ongoing prospective birth-cohort study that enrolled all live-born infants in the Tyrol. Between 1994 and 1999, baseline data were collected for 33 808 infants. From 2000 to 2005, all children hospitalised for atopic asthma at the age of > or =6 years (n = 305) were identified by a careful search of hospital databases. Disease status was ascertained from the typical medical history, a thorough examination and proof of atopy. RESULTS: Living at higher altitude was associated with an enhanced risk of hospitalisation for atopic asthma (multivariate RRs (95% confidence interval 2.08 (1.45 to 2.98) and 1.49 (1.05 to 2.11) for a comparison between altitude categories > or =1200 m and 900-1199 m versus <900 m; p<0.001). This finding applied equally to hospital admissions in spring, summer, autumn and winter. When altitude of residence was analysed as a continuous variable, the risk for asthma hospitalisation increased by 7% for each 100-m increase in altitude (p = 0.013). CONCLUSIONS: This large prospective study shows a significant association between the risk of hospitalisation for atopic asthma and altitude of residence between 450 and 1800 m. The underlying mechanisms remain to be elucidated, but it is tempting to speculate about a role for altitude characteristics such as the decline in outdoor temperature and air humidity and increase in ozone levels, which may trigger airway hyper-responsiveness and attenuate lung function.

Preparation and in vivo evaluation of linkers for 211At labeling of humanized anti-Tac.

The syntheses, radiolabeling, antibody conjugation, and in vivo evaluation of new linkers for 211At labeling of humanized anti-Tac (Hu-anti-Tac), an antibody to the alpha-chain of the IL-2 receptor (IL-2Ralpha) shown to be a useful target for radioimmunotherapy are described. Synthesis of the organometallic linker precursors is accomplished by reaction of the corresponding bromo- or iodoaryl esters with bis(tributyltin) in the presence of a palladium catalyst. Subsequent conversion to the corresponding N-succinimidyl ester and labeling with 211At of two new linkers, N-succinimidyl 4-[211At]astato-3-methylbenzoate and N-succinimidyl N-(4-[211At]astatophenethyl)succinamate (SAPS), together with the previously reported N-succinimidyl 4-[211At]astatobenzoate and N-succinimidyl 3-[211At]astato-4-methylbenzoate, are each conjugated to Hu-anti-Tac. The plasma survival times of these conjugates are compared to those of directly iodinated (125I) Hu-anti-Tac. The N-succinimidyl N-(4-[211At]astatophenethyl)succinamate compound (SAPS) emerged from this assay as the most viable candidate for 211At-labeling of Hu-anti-Tac. SAPS, along with the directly analogous radio-iodinated reagent, N-succinimidyl N-(4-[125I]astatophenethyl)succinamate (SIPS), are evaluated in a biodistribution study along with directly iodinated (125I) Hu-anti-Tac. Blood clearance and biological accretion results indicate that SAPS is a viable candidate for further evaluation for radioimmunotherapy of cancer.

High affinity restricts the localization and tumor penetration of single-chain fv antibody molecules.

Antitumor monoclonal antibodies must bind to tumor antigens with high affinity to achieve durable tumor retention. This has spurred efforts to generate high affinity antibodies for use in cancer therapy. However, it has been hypothesized that very high affinity interactions between antibodies and tumor antigens may impair efficient tumor penetration of the monoclonal antibodies and thus diminish effective in vivo targeting (K. Fujimori et al., J. Nucl. Med., 31: 1191-1198, 1990). Here we show that intrinsic affinity properties regulate the quantitative delivery of antitumor single-chain Fv (scFv) molecules to solid tumors and the penetration of scFv from the vasculature into tumor masses. In biodistribution studies examining a series of radioiodinated scFv mutants with affinities ranging from 10(-7)-10(-11) M, quantitative tumor retention did not significantly increase with enhancements in affinity beyond 10(-9) M. Similar distribution patterns were observed when the scFv were evaluated in the absence of renal clearance in anephric mice, indicating that the rapid renal clearance of the scFv was not responsible for these observations. IHC and IF evaluations of tumor sections after the i.v. administration of scFv affinity mutants revealed that the lowest affinity molecule exhibited diffuse tumor staining whereas the highest affinity scFv was primarily retained in the perivascular regions of the tumor. These results indicate that antibody-based molecules with extremely high affinity have impaired tumor penetration properties that must be considered in the design of antibody-based cancer therapies.

Increasing the affinity for tumor antigen enhances bispecific antibody cytotoxicity.

We tested the hypothesis that bispecific Abs (Bsab) with increased binding affinity for tumor Ags augment retargeted antitumor cytotoxicity. We report that an increase in the affinity of Bsab for the HER2/neu Ag correlates with an increase in the ability of the Bsab to promote retargeted cytotoxicity against HER2/neu-positive cell lines. A series of anti-HER2/neu extracellular domain-directed single-chain Fv fragments (scFv), ranging in affinity for HER2/neu from 10(-7) to 10(-11) M, were fused to the phage display-derived NM3E2 human scFV: NM3E2 associates with the extracellular domain of human FcgammaRIII (CD16). The resulting series of Bsab promoted cytotoxicity of SKOV3 human ovarian carcinoma cells overexpressing HER2/neu by human PBMC preparations containing CD16-positive NK cells. The affinity for HER2/neu clearly influenced the ability of the Bsab to promote cytotoxicity of (51)Cr-labeled SKOV3 cells. Lysis was 6.5% with an anti-HER2/neu K(D) = 1.7 x 10(-7) M, 14.5% with K(D) = 5.7 x 10(-9) M, and 21.3% with K(D) = 1.7 x 10(-10) M at 50:1 E:T ratios. These scFv-based Bsab did not cross-link receptors and induce leukocyte calcium mobilization in the absence of tumor cell engagement. Thus, these novel Bsab structures should not induce the dose-limiting cytokine release syndromes that have been observed in clinical trials with intact IgG BSAB: Additional manipulations in Bsab structure that improve selective tumor retention or facilitate the ability of Bsab to selectively cross-link tumor and effector cells at tumor sites should further improve the utility of this therapeutic strategy.

Delivery of the alpha-emitting radioisotope bismuth-213 to solid tumors via single-chain Fv and diabody molecules.

Intravenously administered anti-tumor single-chain Fv (scFv) and diabody molecules exhibit rapid clearance kinetics and accumulation in tumors that express their cognate antigen. In an attempt to fit the rate of isotope decay to the timing of delivery and duration of tumor retention, anti-HER2/neu CHX-A" DTPA-C6.5K-A scFv and diabody conjugates were labeled with the alpha-particle emitter (213)Bi (t(1/2) = 47 min). Radioimmunotherapy studies employing 0.64, 0.35, or 0.15 microCi of (213)Bi-labeled C6.5K-A diabody or 1.1, 0.6, or 0. 3 microCi of (213)Bi-labeled C6.5K-A scFv were performed in nude mice bearing early, established SK-OV-3 tumors. Only the 0.3 microCi dose of (213)Bi-labeled C6.5K-A scFv resulted in both acceptable toxicity and a reduction in tumor growth rate. The specificity of the anti-tumor effects was determined by comparing the efficacy of treatment with 0.3 and 0.15 microCi doses of (213)Bi-labeled C6.5K-A scFv and (213)Bi-labeled NM3E2 (an irrelevant scFv) in nude mice bearing large established tumors. The 0.3 microCi dose of (213)Bi on both the C6.5K-A and NM3E2 scFvs resulted in similar anti-tumor effects (p = 0.46) indicating that antigen-specific targeting was not a factor. This suggests that the physical half-life of (213)Bi may be too brief to be effectively paired with systemically-administered diabody or scFv molecules.

Complications of percutaneous insertion of Hickman catheters in children.

BACKGROUND/PURPOSE: The aim of this study was a retrospective evaluation of insertion and management complications of percutaneous Hickman catheter lines in pediatric patients to investigate whether the complication rate is acceptable in comparison with other insertion methods or other age groups. METHODS: Over a period of 22 months a total of 27 Hickman catheters were inserted in 22 pediatric patients (20 oncological, 2 nononcological; age 6 weeks to 17.5 years). RESULTS: Twenty-three of 36 insertion attempts (63.9%) were successful at first attempt. In another 4 patients, catheters were placed after repeated attempts. In an additional 4 patients, catheters were inserted by surgeons after percutaneous insertion failed. As immediate complications, 1 pneumothorax and 1 malposition were seen. Late complications included 1 to 29 (median, 8) days of fever in 15 patients, corresponding to 53 of 1,000 catheter days. Fourteen patients showed 21 positive blood cultures, including 11 cases of Staphylococcus epidermides, which might be related to the catheter. Antibiotics were given for a total of 1 to 130 (median, 35) days, that is 205 of 1,000 catheter days. No catheter was removed because of infectious complications. The total life span of the Hickman catheters was 1 to 371 (median, 163) days, the patients were in the hospital from 1 to 351 (median, 102) days because of their underlying disease. At the end of the study period, 8 of 27 (29.6%) catheters remained functioning in situ; 9 (33.3%) had been selectively removed. Two patients died with the catheter (7.4%) functioning well. Another 2 patients showed catheter thrombosis. Six catheters (22.2%) in 5 patients showed inadvertent dislodgement. CONCLUSION: Percutaneous Hickman catheter insertion in pediatric patients is effective; however, complication rate is relevant, but not higher than percutaneous insertion of subclavian vein or Hickman catheters in adults.

Isolation and characterization of an anti-CD16 single-chain Fv fragment and construction of an anti-HER2/neu/anti-CD16 bispecific scFv that triggers CD16-dependent tumor cytolysis.

Bispecific antibody (bsAb)-based clinical trials of cancer have been conducted primarily using intact murine monoclonal antibody (mAb)-derived molecules. In some of these trials, toxicity resulting from the interactions of antibody Fc domains with cellular Fc receptors has limited the doses of antibody (Ab) that can be employed. Furthermore, human anti-mouse Ab responses prohibit multiple therapy courses. These factors have decreased the efficacy of the bsAb 2B1, which targets the extracellular domains (ECD) of the HER2/neu protooncogene product and the human FcgammaRIII (CD16). To address these obstacles, we have constructed and characterized a fully human gene-fused bsAb from single-chain Fv (scFv) molecules specific for HER2/neu and CD16. The human anti-CD16 scFv component, NM3E2, was isolated from a human scFv phage display library. As binding of NM3E2 to human neutrophil-associated CD16 decreased in the presence of plasma IgG, we have concluded that NM3E2 recognizes an epitope in the vicinity of the Fc binding pocket. Furthermore, the NM3E2 scFv was found by surface plasmon resonance-based epitope mapping to share an overlapping epitope with the Leu-11c mAb. The human anti-HER2/neu scFv component, C6.5, which was previously isolated from a human scFv phage display library, was employed as fusion partner for the creation of a bispecific scFv (bs-scFv). In the presence of the C6.5 x NM3E2 bs-scFv, peripheral blood lymphocytes promoted significant lysis of human SK-OV-3 ovarian cancer cells overexpressing HER2/neu. Biodistribution studies performed in SK-OV-3 tumor-bearing scid mice revealed that 1% ID/g of 125I-labeled C6.5 x NM3E2 bs-scFv was specifically retained in tumor at 23 h following injection. These results indicated that both scFv components of the bs-scFv retained their function in the fusion protein. This bsAb should overcome some of the problems associated with the 2B1 bsAb. C6.5 x NM3E2 bs-scFv offers promise as a platform for multifunctional binding proteins with potential clinical applications as a result of its human origin, lack of an Fc domain, ease of production, high level of in vitro tumor cell cytotoxicity and highly selective tumor targeting.

Neopterin levels and pulmonary tuberculosis in infants.

Neopterin is produced and released by human macrophages in response to stimulation with interferon-gamma and changes in neopterin concentrations indicate cellular immune activation. Pulmonary infection with Mycobacterium tuberculosis is also associated with increased neopterin levels in body fluids. We report the clinical course, the diagnostic results, and the urinary neopterin levels of seven children (ages 10 months-6(6/12) years) with pulmonary tuberculosis. Two of them had progressive primary tuberculosis, in one case caused by isoniazid resistance. Diagnostic criteria included chest radiographs, intradermal tuberculosis skin testing, and culture of aspirated secretions for tuberculosis. Neopterin levels were determined by high performance liquid chromatography. The five patients with uncomplicated primary disease and a good response to therapy with isoniazid, rifampin, and pyrazinamide showed no or slightly elevated neopterin levels (mean, 458 micromol/mol creatinine). In the two patients with progressive primary tuberculosis we documented excessively high neopterin levels (mean, 2170 micromol/mol creatinine). We conclude that neopterin may be a useful parameter for measuring the degree of disease activity and the response to therapy.

[Pulmonary sling or ring-sling complex? respiratory problems--diagnosis, therapy, prognosis]. / Pulmonalisschlinge oder "Ring-Sling" Komplex? Respiratorische Probleme--Diagnostik, Therapie, Prognose.

PS is a rare congenital vascular anomaly in which the left pulmonary artery originates from the right pulmonary artery and courses between trachea and esophagus to the hilus of the left lung causing compression of the right mainstem bronchus and trachea. In about half of all cases this vessel anomaly is associated with tracheo-bronchial and/or cardiovascular malformations. We present 6 patients with PS concentrating on the accompanying malformations of the tracheobronchial tree. All patients had the typical symptoms of wheezing and stridor already in early infancy. 3 patients showed concomitant tracheobronchial anomalies. 2 patients had additional cardiovascular deformities. In 3 of the patients the positive clinical course allowed conservative therapy. In the case of 2 further patients the respiratory problems demanded surgery, one of this patients died. A further patient died after palliative surgery of cardiac anomaly.

Effects of the tyrosine-kinase inhibitor geldanamycin on ligand-induced Her-2/neu activation, receptor expression and proliferation of Her-2-positive malignant cell lines.

Geldanamycin belongs to the family of benzoquinoid ansamycin tyrosine-kinase inhibitors. We have examined its effects on Her-2/neu kinase activity, protein expression level, and proliferation of Her-2+ malignant cells. In SK-BR-3 breast-cancer cells, short-time treatment with geldanamycin completely abrogated gp30-ligand-induced activation of Her-2 without a change of receptor-expression level. Longer treatment of intact cells with geldanamycin induced decreased steady-state Her-2 autophosphorylation activity, which correlated with reduction of Her-2 protein expression and phosphotyrosine content of several proteins. The decrease was time- and dose-dependent, starting after 1 hr at 100 nM concentration and reaching completion by 24 hr. The reduction of the Her-2 protein level probably resulted from increased degradation, since the Her-2 mRNA level remained constant. Geldanamycin effects were not specific for Her-2, since the non-receptor tyrosine-kinase fyn was inhibited equally. In contrast to these results, protein-kinase-C activity was not affected. In 3 other malignant cell lines expressing different amounts of Her-2 (SK-BR-3 > SK-OV-3 > OVCAR3 > MCF7), geldanamycin also effectively reduced Her-2-kinase activity proportionally to the decrease of protein expression. In contrast, in a [3H]-thymidine-uptake assay, cell growth was meaningfully inhibited by geldanamycin at nanomolar concentrations only in SK-BR-3 (IC50 2 nM) and MCF7 (IC50 20 nM), while OVCAR3 was only moderately sensitive (IC50 2 microM) and SK-OV-3 was clearly resistant to geldanamycin. In direct comparison with herbimycin A, another benzoquinoid ansamycin that has been more thoroughly characterized, the biologic effects of geldanamycin were more pronounced.

Radioimmunotherapy targeting of HER2/neu oncoprotein on ovarian tumor using lead-212-DOTA-AE1.

UNLABELLED: The specificity, toxicity and efficacy of lead (212Pb) radioimmunotherapy were evaluated in nude mice bearing the SK-OV-3 human ovarian tumor cell line expressing the HER2/neu proto-oncogene. METHODS: The therapeutic agent used was the tumor-specific anti-HER2/neu monoclonal antibody AE1 conjugated to 212Pb, 212Bi being the daughter and thus the source of the alpha-particle and beta emissions. A bifunctional derivative of tetraazacyclododecanetetraacetic acid (p-SCN-Bz-DOTA) was used to couple 212Pb to the anti-HER2/neu monoclonal antibody AE1. The chelating agent did not alter the binding affinity to its antigenic target or the pharmacokinetics and tissue distribution of the AE1 antibody. Toxicity and therapeutic efficacy of 212Pb-AE1 were evaluated in nude mouse ascites or solid tumor models, wherein SK-OV-3 cells were administered i.p. or s.c., respectively. RESULTS: The dose-limiting acute toxicity after i.v. administration of 212Pb-AE1 was bone marrow suppression, which was observed at doses above 25 microCi. Therefore, doses of 10 and 20 microCi were used in efficacy trials. The i.p. administration of 212Pb-AE1 3 days after i.p. tumor inoculation led to a significant (P2 = 0.015) prolongation of tumor-free survival. In a second model, i.v. treatment with 212Pb-AE1 3 days after s.c. tumor inoculation prevented subsequent tumor development in all animals treated with 10 or 20 microCi of 212Pb-AE1 (P2 = 0.002 compared to control groups). This efficacy in the adjuvant setting was antibody specific because treatments with equivalently labeled control antibody or unlabeled AE1 antibody or no treatment were less effective. The rate of growth of small (mean tumor volume, 15 mm3) SK-OV-3 tumors was modestly inhibited. However, tumor growth was not inhibited in mice bearing larger (mean tumor volume, 146 mm3) SK-OV-3 tumors by the administration of a single dose of 10 or 20 microCi of 212Pb-AE1. CONCLUSION: Lead-212-AE1 as an intact radiolabeled monoclonal antibody may be of only modest value in the therapy of bulky solid tumors due to the short physical half-life of 212Pb and time required to achieve a useful tumor-to-normal tissue ratio of radionuclide after administration. However, the radiolabeled monoclonal antibody may be useful in therapy of tumors in the adjuvant setting. Furthermore, 212Pb may be of value in select situations, including treatment of leukemia, intercavitary therapy or strategies that target vascular endothelial cells of tumors.