When the party continues: Impulsivity and the effect of employment on young adults' post-college alcohol use.

BACKGROUND: The transition from college to work is both an exciting and potentially high risk time for young adults. As students transition from academic settings to full-time employment, they must navigate new social demands, work demands, and adjust their drinking behaviors accordingly. Research has shown that there are both protective factors and risk factors associated with starting a new job when it comes to alcohol use, and individual differences can moderate these factors. METHOD: 1361 students were recruited from 4 geographically diverse universities and followed 1month pre- and 1month post-graduation. Drinking frequency, quantity, consequences, and impulsivity were assessed. RESULTS: Full-time employment was related to increased drinking quantity but not related to changes in other drinking outcomes. However, impulsivity moderated the relationship between employment and drinking. For those reporting higher levels of impulsivity at baseline, full-time employment was associated with an increase in drinking variables (quantity and frequency), whereas drinking was unaffected by full-time employment status among those reporting lower levels of impulsivity. Implications for future research are discussed.

Weak to strong pinning crossover.

Material defects in hard type II superconductors pin the flux lines and thus establish the dissipation-free current transport in the presence of a finite magnetic field. Depending on the density and pinning force of the defects and the vortex density, pinning is either weak collective or strong. We analyze the weak to strong pinning crossover of vortex matter in disordered superconductors and discuss the peak effect appearing naturally in this context.

Dendritic cells pulsed with viral oncolysates potently stimulate autologous T cells from cancer patients.

We demonstrated before that primary operated breast cancer patients contain in their bone marrow (BM) cancer reactive memory T cells (MTC) which have to be re-activated to become tumor infiltrating effector cells. The aim of this study was to optimize an ex vivo stimulation protocol for MTC based on autologous dendritic cells (DC). As source of tumor antigens we used lysates from unmodified tumor cells or from tumor cells infected with Newcastle Disease Virus (NDV) which contain IFN-alpha inducing viral dsRNA as one danger signal. DC from breast cancer patients were pulsed with lysates from the MCF-7 breast cancer line (Tu-L) or from NDV infected MCF-7 cells (TuN-L, viral oncolysates) and compared for stimulatory capacity in an ELISPOT response of autologous BM derived MTC. To analyze potential further danger signals derived from NDV infection, we employed MALDI mass spectrometry, Western blots, FACS cytometry and ELISA tests. DC pulsed with viral oncolysates showed increased expression of co-stimulatory molecules in comparison to Tu-L pulsed DC and induced significantly higher ELISPOT MTC responses. Supernatants from co-cultures of MTC and TuN-L pulsed DC contained increased titers of IFN-alpha and IL-15. NDV infection of tumor cells resulted in a number of differences in protein expression including a heat-shock protein (HSP27) which became phosphorylated. The results suggest that a DC preparation pulsed with viral oncolysate includes danger signals (e.g. dsRNA, cytokines, HSP molecules) and is superior for MTC stimulation to a DC preparation pulsed with lysate from non-infected tumor cells.

Full performance of modern echocardiography within the heart: in-vivo feasibility study with a new intracardiac, phased-array ultrasound-tipped catheter.

BACKGROUND: Intracardiac echocardiography with full performance of high-resolution two-dimensional-, M-mode-, colour, pulsed and continuous wave Doppler and Doppler tissue imaging has not been previously demonstrated. AIMS: This first European in-vivo study was designed to determine the utility and feasibility of a new ultrasound-tipped catheter for intravascular and intracardiac echocardiography. METHODS: The miniaturized, multi-modal, multiple-frequency (5-10MHz) transducer tipped 10Fr (3.3mm) catheter was tested in five anaesthetized mongrel dogs linked to a standard echocardiographic platform. The catheter was introduced through an 11 Fr femoral venous sheath into the inferior vena cava and right heart chambers and the pulmonary artery under limited fluoroscopic and catheter ultrasound guidance. RESULTS: Abdominal and thoracic aorta as well as their branches, both ventricles and atrias with their appendices, all valves, pulmonary arteries and all veins could be visualized with excellent quality. All Doppler signals and the determined haemodynamics, global and regional wall motion and Doppler tissue imaging were of high diagnostic quality. Coronary flow reserve could also be determined. CONCLUSIONS: Intracardiac echocardiography is feasible and potentially useful for assessing functional and morphological disorders, and probably for the guidance of interventional procedures as well as monitoring of cardiac function. A new window to the heart has been opened.

Fatal pneumonia in an AIDS patient coinfected with adenovirus and Pneumocystis carinii.

BACKGROUND: Adenovirus infections are common in immunocompromised hosts. However, pulmonary adenovirus infections rarely cause significant morbidity in HIV-infected patients. PATIENT: Here we describe a 27-year-old man with AIDS who presented with tachypnea, hypoxemia and an infiltrate in the upper left lobe on chest X-ray. Bronchoscopy was performed and Pneumocystis carinii was detected in bronchoalveolar lavage (BAL) fluid. Treatment with cotrimoxazole and prednisone initially resulted in improvement, but after 10 days the patient's clinical condition deteriorated rapidly and he died after 23 days due to respiratory failure. RESULTS: On autopsy histopathologic examination showed abundant "smudge cells," suggestive of adenoviral infection. Electron microscopy revealed adenovirus-like particles arrayed in a paracrystalline manner. Subsequent immunohistochemistry confirmed the extensive presence of adenovirus in addition to P. carinii. CONCLUSION: This case demonstrates a pathogenetic role for adenovirus coinfection in P. carinii pneumonia (PCP). Earlier diagnosis, e.g. by PCR analysis of the BAL fluid or transbronchial biopsy, might have led to the consideration of ribavirin treatment.

Export of antigenic peptides from the endoplasmic reticulum intersects with retrograde protein translocation through the Sec61p channel.

Antigenic peptides are translocated by the TAP peptide transporter from the cytosol into the endoplasmic reticulum (ER) for loading onto MHC class I molecules. Peptides that fail to bind need to be removed from the ER. Here we provide evidence that peptide export utilizes the Sec61p translocon as demonstrated by blocking this channel with bacterial exotoxin. Peptide export interferes with the retrotranslocation of beta2-microglobulin from the ER to the cytosol, suggesting similar pathways for the disposal of proteins and oligopeptides. Peptide export requires ATP supply to the ER lumen but is independent of ATP hydrolysis.

Comprehensive allelotype and genetic anaysis of 466 human nervous system tumors.

Brain tumors pose a particular challenge to molecular oncology. Many different tumor entities develop in the nervous system and some of them appear to follow distinct pathogenic routes. Molecular genetic alterations have increasingly been reported in nervous system neoplasms. However, a considerable number of affected genes remain to be identified. We present here a comprehensive allelotype analysis of 466 nervous system tumors based on loss of heterozygosity (LOH) studies with 129 microsatellite markers that span the genome. Specific alterations of the EGFR, CDK4, CDKN2A, TP53, DMBT1, NF2, and PTEN genes were analyzed in addition. Our data point to several novel genetic loci associated with brain tumor development, demonstrate relationships between molecular changes and histopathological features, and further expand the concept of molecular tumor variants in neuro-oncology. This catalogue may provide a valuable framework for future studies to delineate molecular pathways in many types of human central nervous system tumors.

Molecular genetic evidence for subtypes of oligoastrocytomas.

The histogenesis of oligoastrocytomas remains controversial, with some data arguing similarity of oligoastrocytomas to astrocytic tumors, and other data suggesting closer relationships with oligodendroglial neoplasms. Since the molecular genetic changes in astrocytomas differ from those of oligodendrogliomas, we characterized 120 astrocytic and oligodendroglial tumors, including 38 oligoastrocytomas, for genetic alterations that occur disproportionately between astrocytomas and oligodendrogliomas, i.e. TP53 gene mutations and allelic loss of chromosomes 1p, 17p and 19q. As previously reported, TP53 mutations were common in astrocytic gliomas, occurring in approximately half of WHO grade II and III astrocytomas, but in only 5% of WHO grades II and III oligodendrogliomas. Allelic losses of chromosomes 1p and 19q, however, were common in oligodendrogliomas (41% and 63%), but less frequent in astrocytomas (9% and 35%). Oligoastrocytomas showed TP53 mutations in 12/38 (32%) cases and allelic losses of chromosomes 1p and 19q in 52% and 70%, respectively. Most importantly, TP53 mutations and allelic losses on chromosomes 1p and 19q were inversely correlated in oligoastrocytomas (p < 0.011 and p < 0.019). These data suggest the existence of two genetic subsets of oligoastrocytomas, one genetically related to astrocytomas and the other genetically related to oligodendrogliomas. Histologically, those oligoastrocytomas with TP53 mutations were more often astrocytoma-predominant, while those with chromosome 19q loss were more often oligodendroglioma-predominant.

A viral ER-resident glycoprotein inactivates the MHC-encoded peptide transporter.

Human cytomegalovirus inhibits peptide import into the endoplasmic reticulum (ER) by the MHC-encoded TAP peptide transporter. We identified the open reading frame US6 to mediate this effect. Expression of the 21 kDa US6 glycoprotein in human cytomegalovirus-infected cells correlates with the inhibition of peptide transport during infection. The subcellular localization of US6 is ER restricted and is identical with TAP. US6 protein is found in complexes with TAP1/2, MHC class I heavy chain, beta2-microglobulin, calnexin, calreticulin, and tapasin. TAP inhibition, however, is independent of the presence of class I heavy chain and tapasin. The results establish a new mechanism for viral immune escape and a novel role for ER-resident proteins to regulate TAP via its luminal face.

The rational design of TAP inhibitors using peptide substrate modifications and peptidomimetics.

The major histocompatibility complex (MHC)-encoded transporter associated with antigen processing (TAP) translocates peptides from the cytosol into the lumen of the endoplasmic reticulum. This step precedes the binding of peptides to MHC class I molecules and is essential for cell surface expression of the MHC class I/peptide complex. TAP has a broad sequence specificity and a preference for peptides of around 9 amino acids. To synthesize inhibitors for TAP, we studied various alterations of the peptide substrate. The results indicate that TAP is stereospecific and that peptide bonds engineered into isosteric structures can improve translocation of the peptide. Furthermore, TAP is able to translocate peptides with large side chains that correspond to a peptide of approximately 21 amino acids in extended conformation. Peptides with longer side chains compete for the peptide binding site of TAP but fail to be translocated. Therefore, they represent the first rationally designed inhibitors of TAP.

Generation, intracellular transport and loading of peptides associated with MHC class I molecules.

MHC class I molecules present antigenic peptides that are mostly derived from endogenous cytosolic proteins. Recent studies addressing the function of the proteasome and its activator complexes have advanced our understanding of the cytosolic processing of peptides. Transporters associated with antigen processing (TAPs) translocate these peptides to the endoplasmic reticulum where MHC class I molecules, which are retained in transient complexes with chaperones and TAPs, await them for binding. The sequence specificity and the peptide length preference of TAPs roughly meet the requirements of class I molecules in a range of different species, suggesting evolutionary shaping of the specificity of TAPs.

Translocation of long peptides by transporters associated with antigen processing (TAP).

The major histocompatibility complex (MHC)-encoded transporters associated with antigen processing (TAP) translocate peptides from the cytosol into the lumen of the endoplasmic reticulum (ER) where they associate with MHC class I molecules. The length of class I-binding peptides is usually 8-11 amino acids, but examples of significantly longer peptides have been described. The preferred lengths and upper and lower size limits for peptides translocated by TAP have not been determined in detail because in the currently used test systems, peptides are subject to proteolytic degradation. In the present study, three sets of individual peptides or partially randomized peptide libraries ranging between 6 and 40 residues were used that contained a radiolabeled tyrosine and a consensus sequence for ER-specific N-glycosylation at opposite ends, thus ensuring that only nondegraded peptides were monitored in the transport/glycosylation assay. For three different transporters, rat TAP1/2a, rat TAP1/2u and hTAP, the most efficient ATP-dependent transport was observed for peptides with 8-12 amino acids. Hexamers and longer peptides of up to 40 amino acids were also translocated, albeit less efficiently. For two of the three sets of peptides analyzed, rat TAP1/2a showed a less stringent length selection than rat TAP1/2u and human TAP. The superior transport of the decamer of the TNKT.. Y series was not due to faster degradation or less efficient glycosylation of shorter or longer length variants. A binding assay with TAP-containing microsomes revealed a high affinity for the radiolabeled decamer (KD = 580 nM), while other length variants were clearly inferior in their binding affinities. Thus, TAP binds and preferentially translocates peptides with a length suitable for binding to MHC class I molecules, but peptides that are considerably longer may also be substrates. About 10(5) peptide binding sites per cell equivalent of microsomes were determined, providing an estimate for the number of TAP complexes in the ER membrane.

Association of loss of heterozygosity on chromosome 17p with high platelet-derived growth factor alpha receptor expression in human malignant gliomas.

The aim of this study was to examine platelet-derived growth factor alpha receptor (PDGFR-alpha) expression in gliomas of various degrees of malignancy and to correlate the findings with genetic alterations present in the same tumor samples. We analyzed 83 tumors by in situ hybridization using a PDGFR-alpha cRNA probe. Increased PDGFR-alpha mRNA expression was observed in astrocytic tumors of all stages of malignancy, although the highest levels were found in glioblastoma multiforme. To evaluate the frequency of PDGFR-alpha gene amplification, differential PCR requiring less DNA than Southern analysis was used with fluorescence-labeled primers corresponding to the kinase insert region of the PDGFR-alpha. Only 7 of 43 glioblastomas and none of the other tumors tested showed amplification of the PDGFR-alpha gene, suggesting that a mechanism other than gene amplification is responsible for the overexpression of PDGFR-alpha in glial brain tumors. Comparison of the in situ hybridization data with genetic alterations in the same tumor material showed a significant correlation of loss of heterozygosity on chromosome 17p (Fisher's exact, P < 0.0002) with high expression levels of PDGFR-alpha. Because that was the case in both low- and high-grade astrocytomas, our data imply that PDGFR-alpha is actively involved in tumor cell proliferation in early and late stages of glioma development. The association of PDGFR-alpha expression with a distinct subset of glioblastomas characterized by loss of heterozygosity 17p further supports the differentiation of these tumors into molecular variants.

Multiple polymorphisms, but no mutations, in the WAF1/CIP1 gene in human brain tumours.

The cyclin kinase inhibitor WAF1/CIP1, also termed CDKN1, mediates p53-induced cell cycle arrest in response to DNA damage. This property makes it an attractive tumour-suppressor candidate for a p53-associated tumour-suppressor gene. In order to investigate the role of WAF1/CIP1 in the pathogenesis of primary human brain tumours we performed single-stranded conformation polymorphism (SSCP) analysis and direct sequencing of exon 2 of the gene in a representative series of 158 brain tumours and corresponding blood samples. In addition, all tumours were examined for mutations in exons 5-8 of the p53 gene. Analysis of WAF1/CIP1 revealed multiple polymorphisms, the most abundant being AGC-->AGA (Ser-->Arg) at codon 31 with an allele frequency of 8.5%. Less common polymorphisms included GTG-->GGG (Val-->Gly) at codon 25, GCC-->ACC (Ala-->Thr) at codon 64, CGC-->CTC (Arg-->Leu) at codon 32, GGC-->AGC (Gly-->Ser) at codon 14 and GCG-->GTG (Ala-->Val) at codon 39 each with an allele frequency of 0.3%. These polymorphisms were all located in a conserved region of exon 2. Two of the polymorphisms were also seen in a group of 157 healthy controls indicating that WAF1/CIP1 polymorphisms do not predispose to cancer. None of the tumours included in our series showed a somatic mutation in WAF1/CIP1. All samples were also analysed for loss of heterozygosity on the short arm of chromosome 6 in the region of the WAF1/CIP1 locus. Allelic loss was observed in only one patient with a glioblastoma. Mutations in the p53 gene were found in 22 of 158 tumours. No association was found between any polymorphism of the WAF1/CIP1 gene, p53 mutations and histopathological tumour type. Our data indicate that WAF1/CIP1 mutations are probably not involved in the formation of primary human brain tumours.

Expression of lectin, interleukin-2 and histopathologic blood group binding sites in prostate cancer and its correlation with integrated optical density and syntactic structure analysis.

The binding of several biotinylated biologic probes was determined in sections of 20 surgical specimens of prostate cancer and of 21 biopsy specimens of hyperplastic prostate. Whereas neither the immunomodulatory, galactoside-specific lectin from Viscum album nor the human beta-galactoside-specific lectin (M(r) 14 kd) or its specific antibody discerned any remarkable differences, the lectin from Urtica dioica (UDA) and interleukin-2, the in vitro production of which is enhanced by this lectin, exhibited obvious preference for hyperplastic cells. In addition, the presence of binding sites for chemically synthesized blood group determinants was tested. Carcinoma cases revealed a higher percentage of binding of synthetic blood group trisaccharide H than hyperplasia cases. Due to these differences, diverse parameters, derived from measurement of integrated optical density (IOD) and from syntactic structure analysis, were correlated with the extent of binding of these biologic probes for the tumor cases. Primarily, parameters that are related to computation of a minimum spanning tree were significantly different in positive and negative cases for both UDA and interleukin-2. For the binding of blood group trisaccharide H the 5C exceeding rate, the 2CV deviation index and the distance of neighboring tumor cells with an IOD > 5 were clearly dissimilar. Our results thus suggest an extension of the panel of biologic probes for prostate cancer and substantiate the usefulness of correlations of binding of selected biologic probes to features derived from the assessment of IOD and syntactic structure analysis.

Shared allelic losses on chromosomes 1p and 19q suggest a common origin of oligodendroglioma and oligoastrocytoma.

Loss of heterozygosity (LOH) in specific chromosomal regions, which are likely to harbor tumor suppressor genes, has been associated with human gliomas. In this study we have analyzed astrocytic and oligodendroglial tumors for LOH on chromosomes 1 and 19. By microsatellite analysis LOH was found on chromosome arm 1p in 6/15 oligodendrogliomas WHO grade II and III, 12/25 oligoastrocytomas WHO grade II and III, 6/79 glioblastomas WHO grade IV, 5/44 astrocytomas WHO grade II and III and 0/23 pilocytic astrocytomas WHO grade I. The high incidence of LOH on chromosome arm 1p in oligodendrogliomas and oligoastrocytomas indicates that a putative tumor suppressor gene in this region is involved in the formation of gliomas with oligodendroglial features. Furthermore, the frequent involvement of chromosome arm 1p in oligodendrogliomas and oligoastrocytomas, but not in astrocytomas, suggests that genetically oligoastrocytoma is more similar to oligodendroglioma than to astrocytoma. In order to support this hypothesis, oligodendroglial and astrocytic areas in three mixed oligoastrocytomas were examined differentially for LOH 1p and for LOH 19q, the second genetic region believed to be affected in these tumors. All three tumors had LOH of 1p and LOH of 19q in both areas of oligodendroglial and of astrocytic differentiation. These findings show that the astrocytic and oligodendroglial portions of oligoastrocytoma share molecular genetic features and probably are of monoclonal origin.

Cell type-dependent alterations of binding of synthetic blood group antigen-related oligosaccharides in lung cancer.

Blood group antigen-related oligosaccharides have been implicated in growth regulation, cell mobility control and adhesion; we are therefore interested in the localization of receptors for these oligosaccharides in tumour cells. Labelled neoglycoconjugates that carry synthetic sugar structures are suitable tools to determine: whether such binding sites are present in human lung cancer; whether structural alterations of the glycoligand part will affect extent of binding; and whether cell type-associated alterations can be detected. Sections from 121 cases of lung cancer, representing small cell and non-small cell lung carcinoma, mesothelioma and metastases from extrapulmonary primary carcinomas were used to study the binding of nine synthetic AH- and Le-related oligosaccharides. Probes with fucose-alpha 1-3/4-N-acetylglucosamine-beta 1-R, an A-like disaccharide and 3'-sulfated galactose as ligand appear to bind less well to small cell than to non-small cell lung cancer cases, whereas Lec-disaccharide distinguishes mesothelioma from metastatic carcinoma. The latter ligand, A-like disaccharide and H (type III)-like trisaccharide exhibit evident cell type-associated differences in extent of binding. Thus, tailor-made neoglycoconjugates constitute a promising class of histopathological tools that warrants further study.

Gel-immobilized heparin-binding lectin as sensitive sensor for certain groups of charge-bearing carbohydrates.

The specificity of lectins to carbohydrate moieties in principle enables them to serve as sensors for sugars with ligand properties. However, experimental systems and parameters to measure this interaction need to be defined. On the basis of knowledge about temperature-sensitive volume changes of gels, composed of acrylamide derivatives, and about the influence of presence of charge-bearing groups within the gel on this behavior, we covalently immobilized a human heparin-binding lectin into a gel matrix. Besides the lectin-carrying derivative N-isopropylacrylamide and N,N'-methylenebisacrylamide are the monomeric constituents of the polymer. The lectin has been attached to divinyl sulfone-activated N-hydroxymethylacrylamide. Several anionic sugar moieties are added to the solution, covering the gel pieces, and the mechanical response of the individual gel slices in dependence to stepwise temperature increases is automatically recorded with an electronic transducer at a sensitivity of 5 mV/microns. Only carboxyl group-containing sugar moieties like glucuronic acid notably reduce the extent of the temperature-dependent gel shrinking as indicator for a protein-carbohydrate interaction. The individual slices are reuseable, emphasizing practical applications. This sensitive and automated assay concept with the covalently immobilized heparin-binding protein is supposed to be adaptable to other groups of lectins with specificity to anionic sugars like sialic acid-binding proteins.