Characterization of the LIM/homeodomain gene islet-1 and single nucleotide screening in NIDDM.

Islet-1 (Isl-1) is a unique transcription factor that binds to the enhancer region of the insulin gene. To evaluate this gene in non-insulin-dependent diabetes mellitus (NIDDM), a full-length human Isl-1 cDNA was isolated and the genomic structure was characterized. The cDNA [2,395 bp plus additional poly(A) residues] contained an open reading frame from an initiator methionine at nucleotide 240 to an opal stop codon at nucleotide 1,286 (GenBank accession number UO7559), encoding a predicted protein of 349 amino acids (39 kDa).

Mouse endogenous X-linked genes do not show lineage-specific delayed inactivation during development.

X chromosome inactivation (XCI) has been assumed to be complete in all cells of female mouse embryos at about 6 d post coitum (dpc). However, a recent study on beta-galactosidase expression of an X-linked lacZ transgene suggests that XCI is probably not complete several days after this time in some lineages. To help resolve this issue, we analysed XCI in embryos which carry the T(X;16)16H (Searle's) translocation and are heterozygous at the X-linked Hprt and Pgk-1 genes.

Metaphase chromosome analysis by ligation-mediated PCR: heritable chromatin structure and a comparison of active and inactive X chromosomes.

We report that ligation-mediated PCR (LMPCR) can be used for high-resolution study of metaphase chromosomes, and we discuss the role of metaphase chromatin structure in the preservation of differentiated cell states. The X chromosome-linked human PGK1 (phosphoglycerate kinase 1) promoter region was investigated, and euchromatic active X chromosome (Xa) metaphase chromatin was compared with interphase Xa chromatin and to heterochromatic inactive X chromosome (Xi) metaphase and interphase chromatin. We find that (i) good-quality data at single-nucleotide resolution can be obtained by LMPCR analysis of dimethyl sulfate-treated intact metaphase cells; (ii) transcription factors present on the Xa promoter of interphase chromatin are not present on metaphase chromatin, establishing that the transcription complex on the PGK1 promoter must form de novo each cell generation; and (iii) the dimethyl sulfate reactivity pattern of Xa and Xi chromatin at metaphase is very similar to that of naked DNA.

Ancestral, mammalian-wide subfamilies of LINE-1 repetitive sequences.

Analysis of the 3'-ends of approximately 900 separate human LINE-1 (L1) elements from primates revealed 47 contiguous but distinct subfamilies with the L1 family. Eight previously described medium reiteration frequency sequences (MERs) were found to be parts of ancient L1 untranslated 3'-regions which show little or no sequence similarity to the presently active L1 3'-end. Some of the major changes in 3'-end sequence can be explained by recombination events between different L1 repeats as well as between L1 and unrelated repetitive sequences.

MIRs are classic, tRNA-derived SINEs that amplified before the mammalian radiation.

Short Interspersed Nucleotide Elements (SINEs) are highly abundant in mammalian genomes. The term SINE has come to be restricted to short retroposons with internal RNA polymerase III promoter sites in a region derived from a structural RNA (usually a tRNA). Here we describe a novel, 260 bp tRNA-derived SINE, some fragments of which have been noted before to be repetitive in mammalian DNA.

A mutation in the Glut2 glucose transporter gene of a diabetic patient abolishes transport activity.

Glut2, the facilitative glucose transporter isoform expressed in pancreatic beta cells, is believed to play a role in glucose-stimulated insulin secretion. Two polymorphisms that result in amino acid substitutions have been reported in the human Glut2 gene (Tanizawa, Y., Riggs, A.

Isolation of the human LIM/homeodomain gene islet-1 and identification of a simple sequence repeat polymorphism [corrected].

The islet-1 (Isl-1) gene encodes a protein that binds to the enhancer region of the insulin gene. Isl-1 is a member of the LIM/homeodomain family of transcription factors. Because insulin deficiency, either relative or absolute, is a cardinal feature of non-insulin-dependent diabetes mellitus (NIDDM), this study addressed the question of whether mutations in genes that regulate insulin production could be involved.

Human glucagon-like peptide-1 receptor gene in NIDDM. Identification and use of simple sequence repeat polymorphisms in genetic analysis.

Glucagon-like polypeptides, GLP-1-(7-36)-amide and GLP-1-(7-37), are important regulators of insulin synthesis and secretion by islet beta-cells. The hypothesis to be tested in this study was that defects in the islet beta-cell GLP-1 receptor gene contribute to the impaired glucose-regulated insulin secretion of non-insulin-dependent diabetes mellitus (NIDDM). Human islet GLP-1 receptor genomic clones were isolated, and two highly polymorphic simple sequence repeat regions (GLP-1R-CA1 and GLP-1R-CA3) were identified.

Variability of the pancreatic islet beta cell/liver (GLUT 2) glucose transporter gene in NIDDM patients.

The purpose of these experiments was to test the hypothesis that impaired glucose-stimulated insulin secretion in NIDDM is due to mutations in the islet beta cell/liver glucose transporter (GLUT 2) gene. Using oligonucleotide primers flanking each of the 11 exons, the structural portion of the gene was studied by PCR-SSCP analysis. DNA from African-American females (n = 48), who had gestational diabetes but developed overt NIDDM after delivery, was studied.

Structural analysis of Urechis caupo hemoglobin.

The structure of Urechis caupo hemoglobin in the cyanomet state has been refined to R = 0.148 at 2.5 A resolution.

500,000-year stable carbon isotopic record from devils hole, nevada.

The record of carbon-13 (delta(13)C) variations in DH-11 vein calcite core from Devils Hole, Nevada, shows four prominent minima near glacial terminations (glacial-interglacial transitions) V to II. The delta(13)C time series is inversely correlated with the DH-11 oxygen isotope ratio time series and leads it by as much as 7000 years. The delta(13)C variations likely record fluctuations in the delta(13)C of dissolved inorganic carbon of water recharging the aquifer.

Glucokinase gene in gestational diabetes mellitus: population association study and molecular scanning.

Mutations of the glucokinase gene result in early-onset familial Type 2 (non-insulin-dependent) diabetes mellitus, and several members of the mutant glucokinase kindreds were originally diagnosed as having gestational diabetes. This study examined the glucokinase gene in 270 American Black women, including 94 with gestational diabetes whose diabetes resolved after pregnancy (gestational diabetes only), 77 with gestational diabetes who developed Type 2 diabetes after pregnancy (overt diabetes), and 99 normal control subjects who were recruited during the peripartum period. Two simple sequence repeat polymorphisms flanking either end of the glucokinase gene were evaluated.

The hemoglobins of the bullfrog, Rana catesbeiana. Deoxygenation-linked association of tetrameric components B and C to form the trimer BC2: sedimentation analysis and oxygen equilibria.

Hemolysates from the adult bullfrog, Rana catesbeiana, show an unusually high degree of cooperativity of oxygen binding with Hill coefficients greater than 4. The principal components of the tetrameric hemoglobin, B and C, do not show this high cooperativity when isolated, but it reappears when the components are mixed. Sedimentation velocity measurements show that the unusual behavior results from the mixed association of components B and C to form complexes larger than tetramers.

The hemoglobins of the bullfrog, Rana catesbeiana. The cDNA-derived amino acid sequences of the alpha chains of adult hemoglobins B and C: their roles in deoxygenation-induced aggregation.

The adult bullfrog (Rana catesbeiana) has two major tetrameric hemoglobins, B and C, which share a common beta chain but have different alpha chains. Components B and C associate upon deoxygenation to form a complex of the form BC2, a trimer of tetramers that depends on contacts between the alpha B and alpha C chains. Nucleotide sequences of cDNA transcripts for these chains have been determined.

Methylation analysis by genomic sequencing of 5' region of mouse Pgk-1 gene and a cautionary note concerning the method.

We have used genomic sequencing aided by ligation-mediated PCR (LMPCR) to assay for 5-methylcytosine in the CpG-rich promoter region of the mouse X-linked phosphoglycerate kinase gene (Pgk-1). Earlier studies showed that there was very heavy methylation of CpG dinucleotides in the CpG-rich promoter of the human PGK1 gene on the inactive X chromosome (the Xi), but that these same sites were completely unmethylated on the active X chromosome (the Xa). For mouse Pgk-1, previous restriction enzyme analysis had shown apparently complete methylation of only one cytosine in the promoter region on the Xi, at HpaII site H7, which is located in the untranslated region, 28 nucleotides upstream of the translation start site.

Linker chain L1 of earthworm hemoglobin. Structure of gene and protein: homology with low density lipoprotein receptor.

The extracellular hemoglobins (Hbs) of annelids and tube worms are giant multisubunit proteins of up to approximately 200 polypeptides and molecular masses to at least 3,900 kDa. They differ from all other Hbs in having both O2-binding chains and "linker" chains. The latter are required for assembly and structural integrity of the protein and are deficient in or lack heme.

The extracellular hemoglobin of the earthworm, Lumbricus terrestris. Determination of subunit stoichiometry.

The giant extracellular hemoglobin of the earthworm, Lumbricus terrestris, has four major O2-binding chains, a, b, and c (forming a disulfide-linked trimer) and d ("monomer"). Participation of additional "linker" chains L1, L2, and L3 is necessary for the assembly of the approximately 3,900+ kDa two-tiered hexagonal structure. We have determined the proportions of linker chains, trimer, and chain d in the hemoglobin by reverse phase high performance liquid chromatography which resolves all of the components and also permits simultaneous determination of the heme content.

Staff in Australian nursing homes: their qualifications, experience and attitudes.

This paper is based upon findings from a study carried out by the Institute of Nursing Research between 1989 and 1990. The major objective of the study was to determine the impact of staffing mix on nursing home residents' quality of care and life as measured against the standards set out in 'Living in a Nursing Home'. An additional objective was to identify if there are any factors which may constrain or influence optimality.

Genomic footprinting by ligation mediated polymerase chain reaction.

Chromatin structure analysis at single-nucleotide resolution can be done by genomic sequencing, and, recently, several techniques have been developed (1) that give improved specificity and sensitivity over the original method of Church and Gilbert (2). The most sensitive method uses ligation-mediated polymerase chain reaction (LM-PCR) to amplify all fragments of the genomic sequence ladder (3,4). The unique aspect of LM-PCR is the ligation of an oligonucleotide linker onto the 5' end of each DNA molecule.

Quality of care in nursing homes: from the resident's perspective.

This paper derives from a study conducted by the Deakin Institute of Nursing Research between 1988 and 1990, whose major objective was to determine the impact of staffing mix on nursing resident's quality of care and life. Resident satisfaction with life in the nursing home is a key element in determining the quality of care and quality of life provided. Both the literature review and the study objectives supported the view that resident outcome can be collected through assessing the quality of care and the quality of life, through assessment by informed observers using instruments derived from explicitly stated standards, and through eliciting the perceptions of residents themselves.