Tissue-specific variation in C4 and Slp gene regulation.

C4 and Slp are highly homologous mouse genes that differ in function and regulation. Allelic variants exist in quantitative regulation of C4 and in hormonal regulation of Slp. We have examined expression in several tissues, including liver and peritoneal macrophages which are the major sites of synthesis, using a probe that allows direct comparison of C4 and Slp mRNAs. Correctly-sized and initiated RNA, within an order of magnitude of liver levels, is found in mammary gland, lung, spleen, and kidney; lower levels are detectable in testis, brain, heart and submaxillary gland. By comparing expression in congenic mouse strains differing in C4 and Slp loci, regulation of these genes is seen to vary in different tissues. This provides a well-defined genetic system in which to examine cis-acting sequences and trans-acting factors that result in tissue-specific patterns of gene regulation.     

Ferricrocin functions as the main intracellular iron-storage compound in mycelia ofNeurospora crassa

Summary Neurospora crassa produces several structurally distinct siderophores: coprogen, ferricrocin, ferrichrome C and some minor unknown compounds. Under conditions of iron starvation, desferricoprogen is the major extracellular siderophore whereas desferriferricrocin and desferriferrichrome C are predominantly found intracellularly. Mössbauer spectroscopic analyses revealed that coprogen-bound iron is rapidly released after uptake in mycelia of the wild-typeN.crassa 74A. The major intracellular target of iron distribution is desferriferricrocin. No ferritin-like iron pools could be detected. Ferricrocin functions as the main intracellular iron-storage peptide in mycelia ofN. crassa. After uptake of ferricrocin in both the wild-typeN. crassa 74A and the siderophore-free mutantN. crassa arg-5 ota aga, surprisingly little metabolization (11%) could be observed. Since ferricrocin is the main iron-storage compound in spores ofN. crassa, we suggest that ferricrocin is stored in mycelia for inclusion into conidiospores.     

Impedimetric evaluation of the efficiency of disinfectants against biofilms

An impedimetric evaluation of disinfectant efficacy has shown that biofilms of Staphylococcus aureus, Escherichia coli, Salmonella enteritidis and Listeria mono-cytogenes attached to polyvinyl chloride (PVC), Teflon, Plexiglass, wood, rubber and stainless steel are more resistant than the same bacteria in suspension. Based on the activity against the test-organisms after 1, 3 and 5 min with exposures to 0.5, 1 and 2% of each disinfectant, the resistance towards disinfection was related to the type of hard-surface to which biofilms were attached.     

The human IL-1 receptor antagonist gene (IL1RN) maps to chromosome 2q14-q21, in the region of the IL-1 alpha and IL-1 beta loci.

The IL-1 receptor antagonist (IL-1RN) is a protein that binds to IL-1 receptors and inhibits the binding of IL-1 alpha and IL-1 beta. As a consequence, the biological activity of these two cytokines is neutralized in physiological and pathophysiological immune and inflammatory responses. In this study, using a panel of somatic rodent-human cell hybrids, we show that the gene for the human interleukin-1 receptor antagonist (IL1RN) maps to the long arm of chromosome 2. Previously, we described a length variation polymorphism within the second intron of the IL-1RN gene (Steinkasserer et al., 1991, Nucleic Acids Res. 19: 5095). Segregation of this, together with an IL-1 alpha polymorphism, was followed in a panel of five CEPH families. Linkage analysis permitted the mapping of the IL-1RN gene to band q14-q21 in the region for the IL-1 alpha and IL-1 beta loci. This study supports the view that an early gene duplication event resulted in the creation of an interleukin-1 gene family.     

Cloning and linkage mapping of three polymorphic tetranucleotide (TAAA)n repeats on human chromosome 21.

We report the cloning, sequencing, and mapping of three short sequence repeat polymorphisms due to tetranucleotide (TAAA)n repeats from human chromosome 21. These DNA markers (D21S221, D21S225, D21S226) have been cloned from the chromosome 21-specific plasmid library of J. C. Fuscoe, C. C. Collins, D. Pinkel, and J. W. Gray (1989, Genomics 5: 100-109) and were shown to be polymorphic by polymerase chain reaction amplification and polyacrylamide gel electrophoresis. Genotypes were determined in informative CEPH pedigrees and used in linkage analysis relative to other mapped markers on human chromosome 21. One of these markers, D21S221, is closely linked to the amyloid precursor protein gene (APP), which has been implicated in the etiology of familial Alzheimer disease in some families.     

Comparison of dopamine uptake and release in vitro in sheep and rat striatum.

Cocaine inhibits tritium-labeled dopamine ([3H]DA) uptake in rat (IC50 approximately 400 nM) and sheep (IC50 approximately 1 microM) striatum. GBR 12909, a selective DA uptake inhibitor, potently inhibits [3H]DA uptake in rat (IC50 less than 10 nM), but is less effective (only 60% of the uptake is inhibited at a concentration of 10 microM) and less potent (IC50 approximately 300 nM) in sheep. [3H]DA release from slices of rat or sheep striatum is stimulated by potassium (15-50 mM). In the presence of nomifensine (10 microM), cocaine (10 microM) had no effect on potassium-stimulated [3H]DA release in either species. [3H]DA release is increased by N-methyl-D-aspartate (NMDA) (10-1000 microM) in rat striatum but NMDA did not stimulate [3H]DA release in sheep striatum. These findings suggest that NMDA receptors either are absent from or do not regulate release of preloaded [3H]DA in sheep striatum.