Producing over 100 ml of highly concentrated hyperpolarized solution by means of dissolution DNP.

New low-temperature inserts compatible with an existing hyperpolarizer were developed to dynamically polarize nuclei in large samples. The performance of the system was tested on 8 ml glassy frozen solutions containing 13C-labeled molecules and doped with nitroxyl free radicals. The obtained 13C low-temperature polarization was comparable to the one measured on 20 times smaller sample volume with only 3-4 times higher microwave power. By using a dissolution insert that fits to the new design, it was possible to obtain about 120 ml of room-temperature hyperpolarized solution. The polarization as well as the molecule concentration was comparable to the values obtained in standard size hyperpolarized samples. Such large samples are interesting for future studies on larger animals and possibly for potential clinical applications.

Detection and traceability of genetically modified organisms in the food production chain.

Both labelling and traceability of genetically modified organisms are current issues that are considered in trade and regulation. Currently, labelling of genetically modified foods containing detectable transgenic material is required by EU legislation. A proposed package of legislation would extend this labelling to foods without any traces of transgenics. These new legislations would also impose labelling and a traceability system based on documentation throughout the food and feed manufacture system. The regulatory issues of risk analysis and labelling are currently harmonised by Codex Alimentarius. The implementation and maintenance of the regulations necessitates sampling protocols and analytical methodologies that allow for accurate determination of the content of genetically modified organisms within a food and feed sample. Current methodologies for the analysis of genetically modified organisms are focused on either one of two targets, the transgenic DNA inserted- or the novel protein(s) expressed- in a genetically modified product. For most DNA-based detection methods, the polymerase chain reaction is employed. Items that need consideration in the use of DNA-based detection methods include the specificity, sensitivity, matrix effects, internal reference DNA, availability of external reference materials, hemizygosity versus homozygosity, extrachromosomal DNA, and international harmonisation. For most protein-based methods, enzyme-linked immunosorbent assays with antibodies binding the novel protein are employed. Consideration should be given to the selection of the antigen bound by the antibody, accuracy, validation, and matrix effects. Currently, validation of detection methods for analysis of genetically modified organisms is taking place. In addition, new methodologies are developed, including the use of microarrays, mass spectrometry, and surface plasmon resonance. Challenges for GMO detection include the detection of transgenic material in materials with varying chromosome numbers. The existing and proposed regulatory EU requirements for traceability of genetically modified products fit within a broader tendency towards traceability of foods in general and, commercially, towards products that can be distinguished from each other. Traceability systems document the history of a product and may serve the purpose of both marketing and health protection. In this framework, segregation and identity preservation systems allow for the separation of genetically modified and non-modified products from "farm to fork". Implementation of these systems comes with specific technical requirements for each particular step of the food processing chain. In addition, the feasibility of traceability systems depends on a number of factors, including unique identifiers for each genetically modified product, detection methods, permissible levels of contamination, and financial costs. In conclusion, progress has been achieved in the field of sampling, detection, and traceability of genetically modified products, while some issues remain to be solved. For success, much will depend on the threshold level for adventitious contamination set by legislation.

Splenic infarction in Wegener's granulomatosis.

We describe a case of severe Wegener's granulomatosis associated with asymptomatic splenic infarction. The 4 previous case reports are reviewed and the implication of this finding for preventive strategies is highlighted.

PCR-RFLP analysis of mitochondrial DNA: a reliable method for species identification.

A method for identification of game species has been developed on the basis of the amplification of a specific part of the mitochondrial genome (tRNA(Glu)/cytochrome b) using the polymerase chain reaction (PCR). To distinguish between several game species, the obtained 464-bp-long PCR products were cut with different restriction endonucleases (RE) resulting in species-specific restriction fragment length polymorphism (RFLP). Even closely related deer species could be distinguished by application of one or two RE. Natural polymorphisms of the target sequence within one species were examined for red deer (Cervus elaphus), and base pair substitutions were identified affecting the RFLP pattern.

An unusual cause of back pain.

This case describes what may become an increasingly common clinical problem in Australia as the proportion of our population originally derived from South East Asia, ages. Our patient was of Chinese origin and presented with back pain which was eventually found to be due to metastatic disease from an otherwise silent hepatoma, in association with unrecognised chronic hepatitis B infection.

Prolonged response of multicentric reticulohistiocytosis to low dose methotrexate.

We describe a case of multicentric reticulohistiocytosis complicated by central retinal vein thrombosis and trigeminal neuropathy. A variety of treatment modalities were tried in this patient. Both skin disease and arthritis responded to low dose methotrexate over 8 years of followup. Graduated compression gloves produced an excellent cosmetic improvement in the disfiguring skin lesions.

Regulation of ob gene mRNA levels in cultured adipocytes.

mRNA levels of the ob gene product, leptin, were investigated by quantitative competitive RT-PCR in a mouse cell line (3T3-L1) which can be induced to differentiate into adipocytes. During conversion to fat cells, the level of leptin mRNA increased several-fold and in parallel to that for typical adipocyte markers like lipoprotein lipase, adipsin and glycerophosphate dehydrogenase. Leptin transcription, however, did not correlate with the size of the adipocytes measured as total triglycerides. On the other hand, mRNA levels for leptin in fully differentiated adipocytes were increased 2-3 fold by insulin. In contrast, free fatty acids exerted a concentration-dependent inhibition of leptin transcription while the corticosteroid dexamethasone and an elevation of intracellular cAMP displayed only marginal inhibitory effects on leptin mRNA levels.

Structure and chromosomal localization of the mouse oncomodulin gene.

The rat gene encoding oncomodulin (OM), a small calcium-binding protein, is under the control of a solo LTR derived from an endogenous intracisternal A-particle. The latter sequence is the only OM promoter analyzed so far. In order to study cell type-specific OM expression in a species lacking LTR sequences in the OM locus, we initially synthesized an OM cDNA from mouse placenta. By sequencing, we found a 137-bp-long 5'leader region that differed markedly from its rat counterpart but had high similarity to several mouse genomic sequences. Primers specific to this sequence in addition with primers specific for an exon 2/intron 2 sequence were used to screen a mouse ES cell line genomic P1 library. One positive clone contained the whole OM gene, including intron 1 of 25kb and a 5' flanking region of 27 kb lacking an LTR. The region upstream of exon 1 contains no TATA or CCAAT boxes but has a homopurine/homopyrimidine stretch of 102 bp as well as a (CA)22 repeat. The latter sequence is polymorphic and was therefore, used to map the OM gene to the distal end of the long arm of mouse Chromosome (Chr) 5 by interspecific backcross analysis. Additionally we localized the OM gene by in situ hybridization to the region G1-3 on Chr 5, confirming the genetic linkage results. Finally, the OM gene was found to be structurally conserved and to exist in a single copy in mammals.

Recombinant ob-gene product reduces food intake in fasted mice.

The ob-gene encodes for a protein of 167 amino acids which is expressed exclusively in white adipose tissue. The ob-gene product is probably released from adipocytes as a soluble hormone of 146 amino acids and has been proposed as a satiety factor. To test this hypothesis, the soluble portion of the ob-gene product devoid of signal sequence was expressed in E. coli and purified. The purified protein, which contains two Cys residues, was recovered from the periplasm in an oxidized form. After a single intravenous injection, the ob-gene product decreased food intake after fasting in normal mice. The results show that recombinant ob-gene product can be obtained in a functionally active conformation and provide direct proof that this protein is a satiety factor.

Sequence variations and promoter activities of long terminal repeats from rat intracisternal A-particles.

Nucleotide sequences of three novel rat long terminal repeats (LTR) of intracisternal A-particles (IAP) were determined and compared with two previously published solitary rat IAP LTRs from the genomic clone H12 (Furter et al. (1989) J. Biol. Chem. 264, 18276-18279) and from the upstream region of the oncomodulin (OM) gene (Banville and Boie (1989) J. Mol. Biol. 207, 481-490). These five LTRs have a length of 286 to 370 bp and show the major variability within the U3 region. The CCAAT and the TATA boxes, the AATAAA polyadenylation signals and the CA polyadenylation sites are well conserved in sequence and position in all five LTRs, whereas several putative transcriptional factor binding sites in the U3 domain show considerable heterogeneity. The transcriptional activities of three LTRs were tested in transient gene expression assays using the human growth hormone (hGH) reporter gene in chemically transformed T14c cells which produce considerable amounts of oncomodulin. Promoter strengths of the three investigated LTRs varied considerably.

[Acute fatty liver of pregnancy and subsequent pregnancy]. / Akute Schwangerschaftsfettleber und nachfolgende Gravidität.

Report on a second para, aged 25 years, with acute fatty degeneration of her liver in the 35th gestational week of a twin pregnancy. Treatment was successful. After an interval of 2 years she conceived again. This pregnancy was without complications. A healthy child was born in the 39th gestational week.

[Endoscopic-radiologic cholangio-pancreaticography (author's transl)]. / Endoskopisch-radiologische Cholangio-Pankreatikographie

Results of 408 own endoscropic-radiologic cholangio-pancreatico-graphies are presented, indications and diagnostic relevance of the method are discussed. Low rate of complications and its high diagnostic value are reasons for ERCP's clinical importance even as a routine procedure at gastro-enterological centers. In the future, cytological, immunological and biochemical analysis of juices and aspirates as well as endoscopic surgery will contribute to an even wider clinical use of the method. In 337 patients (82.6%) cannulation of the papilla of Vater and visualization of one or both duct systems were successful. In 198 cases with visualization of ducts (58.8%) pathological lesions were found. Thus observation of indications and contra-indications of ERCP is documented, of a method, which is not too risky, but relatively expensive and difficult to employ.