Circular dichroism and two-dimensional NMR spectra indicate that a peptide fragment consisting of the first 28 residues from the N-terminus of human growth hormone (hGH 1-28) has considerable alpha-helical structure. The peptide, (1) H-Phe-Pro-Thr-Ile-Pro-Leu-Ser-Arg-Leu-Phe-Asp-Asn-Ala-Met-Leu-Arg-Ala-Hi s-Arg- Leu-His-Gln-Leu-Ala-Phe-Asp-Thr-Tyr-OH (28), was synthesized on an automated peptide synthesizer using the Merrifield solid-phase method. The peptide can be modeled as an amphiphilic helix, and the unusual stability of the alpha-helix in aqueous solution is suggested to be attributable to formation of a dimer of alpha-helices. Most of the 1H NMR signals were assigned through pure absorption phase COSY/NOESY and single- and double-relay COSY 2D NMR spectra by using the sequential assignment methodology. The NOEs were large and negative, suggesting that the peptide was not a random coil and that it existed in solution primarily as a large, fairly rigid macromolecule, consistent with the dimer structure. A network of N alpha Hi-N alpha Hi+1 NOESY crosspeaks is observed from residues 13 to 18 as are several other crosspeaks which indicate that the peptide has considerable alpha-helical structure between residues 8 and 24. In addition, gel filtration of the peptide is consistent with a dimer structure, presumably involving packing of the two hydrophobic faces of the amphiphilic alpha-helices.

Amino Acid Sequence↗

PubMed1989

Use of the triplex scanner in diagnosis of deep venous thrombosis.

We report our experience with 264 patients who underwent triplex scans for venous occlusive disease over a 10-month period. Venography was obtained in 30 of these patients. Correlation between the two procedures was 100%. The anatomic location of thrombosis and the extent of disease were identical in both studies. The presence of intraluminal clot by angiodynography is detected by looking for changes in the venous color-flow patterns and in the B-mode image. Newer clots have low echogenicity and are seen as large black areas in the gray-scale image. Older clots are more echogenic. The presence of enlarged venous collateral veins as well as absence of color flow and inability to compress the veins confirm the diagnosis of acute deep venous thrombosis. The results of angiodynography alone can be used safely in diagnosing acute deep venous thrombosis in patients. Equally important, treatment can be withheld safety in a patient with normal results.

Arm↗

PubMed1989

Mapping of the gene encoding the multifunctional protein carrying out the first three steps of pyrimidine biosynthesis to human chromosome 2.

The CAD gene encodes a trifunctional protein that carries the activities of the first three enzymes (carbamyl phosphate synthetase II, aspartate transcarbamylase, and dihydroorotase) of de novo pyrimidine biosynthesis. Genomic fragments of the human CAD gene have been obtained by screening a human genomic library in bacteriophage lambda using a Syrian hamster cDNA clone as a probe. These human genomic clones have been used to assign the CAD gene to human chromosome 2 using in situ hybridization to human metaphase chromosomes and Southern blot hybridization analysis of DNA isolated from a panel of Chinese hamster/human hybrid cells. In situ hybridization analysis has allowed further localization of this gene to the chromosomal region 2p21-p22.

Amidohydrolases↗

PubMed1989

A fine-structure deletion map of human chromosome 11p: analysis of J1 series hybrids.

Deletion analysis offers a powerful alternative to linkage and karyotypic approaches for human chromosome mapping. A panel of deletion hybrids has been derived by mutagenizing J1, a hamster cell line that stably retains chromosome 11 as its only human DNA, and selecting for loss of MIC1, a surface antigen encoded by a gene in band 11p13. A unique, self-consistent map was constructed by analyzing the pattern of marker segregation in 22 derivative cells lines; these carry overlapping deletions of 11p13, but selectively retain a segment near the 11p telomere. The map orders 35 breakpoints and 36 genetic markers, including 3 antigens, 2 isozymes, 12 cloned genes, and 19 anonymous DNA probes. The deletions span the entire short arm, dividing it into more than 20 segments and define a set of reagents that can be used to rapidly locate any newly identified marker on 11p, with greatest resolution in the region surrounding MIC1. The approach we demonstrate can be applied to map any mammalian chromosome. To test the gene order, we examined somatic cell hybrids from five patients, whose reciprocal translocations bisect band 11p13; these include two translocations associated with familial aniridia and two with acute T-cell leukemia. In each patient, the markers segregate in telomeric and centromeric groups as predicted by the deletion map. These data locate the aniridia gene (AN2) and a recurrent T-cell leukemia breakpoint (TCL2) in the marker sequence, on opposite sides of MIC1. To provide additional support, we have characterized the dosage of DNA markers in a patient with Beckwith-Wiedemann syndrome and an 11p15-11pter duplication. Our findings suggest the following gene order: TEL - (HRAS1, MER2, CTSD, TH/INS/IGF2, H19, D11S32) - (RRM1, D11S1, D11S25, D11S26) - D11S12 - (HBBC, D11S30) - D11S20 - (PTH, CALC) - (LDHA, SAA, TRPH, D11S18, D11S21) - D11S31 - D11S17 - HBVS1 - (FSHB, D11S16) - AN2 - MIC1 - TCL2 - delta J - CAT - MIC4 - D11S9 - D11S14 - ACP2 - (D11S33, 14L) - CEN. We have used the deletion map to show the distribution on 11p of two centromeric repetitive elements and the low-order interspersed repeat A36Fc. Finally, we provide evidence for an allelic segregation event in the hamster genome that underlies the stability of chromosome 11 in J1. The deletion map provides a basis to position hereditary disease loci on 11p, to distinguish the pattern of recessive mutations in different forms of cancer and, since many of these genes have been mapped in other mammalian species, to study the evolution of a conserved syntenic group.

Animals↗

PubMed1989

Immunohistochemical localization of renin and angiotensin II in human ovaries.

Ovaries from six women with normal menstrual cycles, a follicle wall biopsy specimen from a gonadotropin-stimulated preovulatory ovary, and a corpus luteum of pregnancy were examined by immunohistochemistry for the presence of immunoreactive renin and angiotensin II. Both antisera densely stained thecal and stromal cells (interstitial complex) and luteal cells. Whereas granulosa cells in developing follicles were either unstained or lightly stained, the heavily luteinized granulosa cells of the preovulatory stimulated follicle were strongly positive for immunoreactive renin and angiotensin II. These anatomic findings are consistent with gonadotropin-stimulated local production of both renin and angiotensin II in the human ovary and support the functional roles proposed for the ovarian renin-angiotensin system in follicle development, ovulation, and luteal function and during pregnancy.

Adult↗

PubMed1989

The minimal transforming fragment of HSV-2 mtrIII can function as a complex promoter element.

The minimal transforming fragment (486 TF) of HSV-2 mtrIII (0.567-0.570 map units) is composed of two distinct and non-overlapping promoter elements when linked to bacterial CAT genes. A 230-nucleotide fragment of 486 TF, Sal1-Hpa1, was active as a promoter element in primate cells but not rodent cells. A 173-nucleotide fragment, Sma1-Pst1, was active in both primate and rodent cells. The 486 TF did not compete for limiting cellular factors required to drive the CAT gene under control of the SV40 early promoter/enhancer. However, gel-retardation assays suggest that unique factors exist in cells transformed by HSV-2 which specifically recognized regions of 486 TF. These results are discussed with respect to HSV-2-mediated transformation.

Animals↗

PubMed1989

NOEMOL: integrated molecular graphics and the simulation of Nuclear Overhauser effects in NMR spectroscopy.

Nuclear Overhauser effects (NOEs) are a widely used method of determining the spatial proximity of spins in Nuclear Magnetic Resonance (NMR) spectroscopy. This paper describes a C program developed for the Sun-3 workstation family that allows the computation of multispin NOE effects for a given molecular structure and given NMR parameters (i.e., resonance frequency and correlation time for molecular reorientation). The integration of these facilities with simple molecular graphics display routines allows modifications to the molecular conformation (such as bond rotations) to be performed, and the effect of these modifications on the NOE effects can then be rapidly calculated and easily visualized. Using the Sun windowing system, the NOE effects can be calculated for two (or more) candidate structures and compared to experimental NMR results. The overall molecular reorientation can be modeled by either isotropic or symmetric top diffusion models, and the internal motions of methyl groups are modeled using an algorithm reported by Tropp.

Carbohydrate Sequence↗

PubMed1989

Mechanistic investigation of species-specific thyroid lesions induced by treatment with the histamine H1 antagonist temelastine (SK&F 93944) in rats.

Temelastine (SK&F 93944), an H1 histamine receptor antagonist, induces thyroid histopathological lesions in the rat, indicative of thyroid follicular cell stimulation, at oral doses of 10-33 mg/kg body weight/day. These changes do not occur in the dog or mouse. Endocrinological short-term studies support an increased thyroid follicular activity (increased radioiodide accumulation) with decreased circulating thyroxine (T4) at oral doses at or above 300 mg/kg body weight/day and increased circulating thyroid stimulating hormone (TSH). This is thought to be responsible for the thyroid follicular stimulation following Temelastine treatment. No direct inhibition of thyroid function occurs. Temelastine produces these species-specific changes by enhancing thyroxine clearance from the circulation in the rat, but not in the dog or mouse. In vitro studies with cultured rat hepatocytes suggest that the mechanism behind these changes is a drug-induced increase of hepatocellular T4 binding and uptake which leads to an enhanced metabolic clearance of the hormone.

Animals↗

PubMed1989

Intraoperative dosimetry of 90Y in liver tissue.

The use of an intraoperative radiation detection probe was assessed following the injection of 90Y labelled radioactive microspheres into the normal liver of 10 sheep. The absorbed dose to the liver ranged from 10 to 50 Gy. There was a linear relationship between the probe recordings and the radiation dose as measured by scintillation counting of liver tissue. By using the probe during the procedures for internal radiation therapy the injected dose of radioactive microspheres can be manipulated to provide the maximum tolerable dose to normal tissue.

Animals↗

PubMed1989

Linked markers flanking the gene for multiple endocrine neoplasia type 2A.

The inherited cancer syndrome multiple endocrine neoplasia type 2A (MEN2A) has recently been mapped to chromosome 10. We have typed 29 families with this disorder with DNA markers from the pericentromeric region of chromosome 10. Two markers, RBP3 and MCK2, were tightly linked to the MEN2A gene at recombination fractions of less than 3%. Multipoint analysis of the linkage data suggests that the gene is located within a 3-cM interval defined by the markers RBP3/MCK2 on one side and TB14.34 on the other. No evidence for locus heterogeneity was detected in any of the 27 families from 14 countries who were informative for the markers tested. The data confirm and refine the original assignment and provide the basis for presymptomatic screening for this disorder.

Chromosome Mapping↗

PubMed1989

Gene order, amplification, and rearrangement of chromosome band 11q23 in hematologic malignancies.

Eleven genes were found to be amplified in a patient with acute myelogenous leukemia and a homogeneous staining region 11q23qter. The gene order of such region was determined by using transverse alternating field electrophoresis of normal cell DNA and Southern blots of DNA from somatic cell hybrids, each containing a single human derivative chromosome 11 from six different chromosomal defects. This in turn allowed us to uncover a breakpoint in band 11q23.3 between the CD3 gamma and the ets-1 genes in genomic rearrangements found in acute myelogenous leukemia, acute lymphocytic leukemia, and B-cell diffuse lymphoma. The breakpoint of a constitutional deletion from a patient whose mother and brother have a heritable 11q23.3 fragile site occurs in the same region.

Adult↗

PubMed1989

Folate analogues. 32. Synthesis and biological evaluation of 2-desamino-2-methyl-N10-propargyl-5,8-dideazafolic acid and related compounds.

The chemical synthesis of three close analogues (2-4) of N10-propargyl-5,8-dideazafolate (PDDF) is described. The quinazoline ring of 2 and 4 was constructed from the pivotal intermediate 9 in a novel and unambiguous manner during the final step of the synthesis under very mild conditions. 2-Desamino-2-methyl-N10-propargyl-5,8-dideazafolate (DMPDDF) (2) was a strong inhibitor of human and Lactobacillus casei thymidylate synthases, whereas 2-desamino-2-(trifluoromethyl)-N10-propargyl-5,8-didezafolate (3) and 2-desamino-2,3-dimethyl-N10-propargyl-5,8-dideazafolate (4) were only weak inhibitors of this enzyme. DMPDDF exhibited excellent growth inhibition of Manca human lymphoid leukemia and H35 hepatoma cells in culture. The inhibitor activities of 2 were 43- and 65-fold greater than that of PDDF, respectively, in these cell lines. H35R cells that are resistant to methotrexate by virtue of a transport defect were cross resistant to DMPDDF but not to PDDF. H35FF cells which have 70-fold greater amounts of thymidylate synthase compared to H35N cells were 130-fold resistant to DMPDDF. Furthermore, the toxicity of DMPDDF to H35 hepatoma cells could be completely reversed by thymidine, establishing its locus of action as thymidylate synthase. Transport studies in vitro established that DMPDDF effectively inhibits MTX influx into H35 hepatoma cells, whereas PDDF has no effect on MTX transport in this cell line. These data suggest that the greater activity of DMPDDF relative to PDDF is partly due to the ability of the former compound to enter cells via the MTX/reduced folate transport system. Enzyme inhibition data of 4 suggest that the presence of N3H in DMPDDF is essential for binding to thymidylate synthase.

Breast Neoplasms↗

PubMed1989

Enhanced in vivo activity of adriamycin incorporated into controlled release microspheres.

A comparison of the cytotoxic effectiveness of adriamycin incorporated into ion exchange microspheres with conventional chemotherapeutic use of adriamycin was carried out in a rat tumour model. Drug microspheres were targeted to the tumours by embolisation into the arterial supply of the hind limb bearing the tumour. Microspheres were found to embolise in tumour tissue at concentrations of up to 39 times that of the surrounding normal tissue. As a result, adriamycin microsphere therapy was found to retard significantly (P less than 0.01) tumour growth rates compared to growth rates associated with similar doses of adriamycin delivered as free drug rather than bound to controlled release microspheres. Equivalent sham microsphere treatments showed no significant difference in tumour growth rates compared with the control group. Adriamycin loaded on to ion exchange microspheres holds strong potential for treatment of human malignancy.

Adenocarcinoma↗

PubMed1989

Sisters of Charity and the ailing poor.

Explore the source record for details and available documents.

France↗