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J Meissner

Publications and source records attributed to J Meissner.

At least 19 recordsLinked to original sources
PubMed2003

Complete coding sequences of dengue-1 viruses from Paraguay and Argentina.

We have determined the complete coding sequences of six dengue-1 (DEN-1) viruses isolated from Paraguay and Argentina in 2000 from patients with dengue fever. Sequences of strains 259par00, 280par00, 295arg00, 297arg00 and 301arg00 can encode a polyprotein of 3392 amino acids. Strain 293arg00 circulated as a "wild type+deletion mutant" quasispecies, with a subpopulation characterized by a 3-nucleotide deletion in the NS4A region. This variant, which would encode a three amino acid change in the NS4A protein, was found as a minority population in one additional partially-sequenced isolate from the same outbreak. These six South American strains group into two different clades of the "American-African" DEN-1 genotype-one clade is most closely related to strains isolated from Brazil in 1997, the other to a Peruvian strain isolated in 1991 for which only partial sequence information is available. DEN-1 viruses isolated worldwide comprise at least four different genotypes according to previously defined classification criteria.

Amino Acid Sequence↗
PubMed2002

Phylogenetic relationships of dengue-1 viruses from Argentina and Paraguay.

We sequenced the Capsid-pre Membrane (C/prM) and the Envelope-Nonstructural protein 1 (E/NS1) regions of 24 recent isolates of dengue-1 (DEN-1) from South America. This included 12 Argentinean and 11 Paraguayan DEN-1 strains isolated in 2000 plus a Paraguayan strain isolated in 1988. These sequences were compared with published sequences of DEN-1 isolated worldwide to determine the origin of these isolates. Pairwise comparisons of strains from Paraguay and Argentina revealed a nucleotide divergence of 0-5% in the E/NS1 region and 0-3% in the C/prM region. Our results showed that these viruses belong to the same genotype, but can be separated into two clades. Interestingly, both clades circulated simultaneously in the same geographic area during the 2000 outbreaks. Amino acid differences were found between both clades in the C/prM region at position 100 (Lys vs. Arg) and in the E/NS1 region at positions 722 (Ala vs. Thr). Although the geographic movement of DEN-1 virus can not be unequivocally traced from the genetic relationship determined here, our results suggest that the recent epidemics in Argentina and Paraguay were due to the re-emergence of a previously circulating strain, or to the virus circulating unnoticed, rather than to the introduction of a new genotype.

Amino Acid Sequence↗
PubMed1999

Stem cell factor influences neuro-immune interactions: the response of mast cells to pituitary adenylate cyclase activating polypeptide is altered by stem cell factor.

Mast cells degranulation can be elicited by a number of biologically important neuropeptides, but the mechanisms involved in mast cell-neuropeptide interactions have not been fully elucidated. Stem cell factor (SCF), also known as c-kit or kit ligand, induces multiple effects on mast cells, including proliferation, differentiation, maturation, and prevents apoptosis. We investigated the ability of SCF to affect mast cell responsiveness to the neuropeptides pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP). PACAP 1-27, PACAP1-38, or VIP failed to induced preformed mediator release from mouse bone-marrow-cultured mast cells (BMCMC) derived in concanavalin A-stimulated spleen conditioned medium (CM). By contrast, BMCMC grown in SCF-containing medium or freshly isolated peritoneal mast cells exhibited significant 3H-hydroxytrypamine (5-HT) release in response to PACAP peptides or VIP. Deoxyglucose and the mitochondrial inhibitor antimycin significantly inhibited PACAP-induced 5-HT release indicating that the central event induced by PACAP peptides was exocytosis. The G(alpha)i inhibitor, pertussis toxin, significantly diminished PACAP-induced 5-HT release from BMCMCs in SCF suggesting the involvement of heterotrimeric G-proteins. Western blot analysis using antibodies directed against the human VIP type I/PACAP type II receptor demonstrated a 70-72 kD immunoreactive protein expressed in greater amounts in BMCMC grown in SCF compared with BMCMC in CM. We conclude that SCF induces a mast cell population that is responsive to PACAPs and VIP involving a heterotrimeric G-protein-dependent mechanism.

Animals↗
PubMed1997

The promoter of the human type I 5'-deiodinase gene--mapping of the transcription start site and identification of a DR+4 thyroid-hormone-responsive element.

The selenoenzyme thyroxine 5'-deiodinase type I deiodinates the prohormone thyroxine to the active thyroid hormone 3,3',5-triiodothyronine. It is thus one of the key enzymes involved in the triiodothyronine-mediated control of growth, differentiation and basal metabolism in vertebrates. We report here the identification of the transcription start site and the cloning of 1500 bases of the upstream regulatory region of the human 5'-deiodinase gene. They contain a complex triiodothyronine-responsive element at nucleotides -696 to -673, consisting of an ideal direct repeat (DR) of two AGGTCA half-sites with a spacing of four nucleotides (DR+4) and a third putative AGTTCA half-site with a spacing of another two nucleotides (DR+2). The whole DR+4+2 specifically bound to thyroid hormone receptor and retinoid X receptor in electrophoretic mobility shift assays. The DR+4+2 mediates triiodothyronine-responsiveness in cotransfection experiments of constructs containing the 5'-deiodinase upstream promoter and enhancer region fused to luciferase or chloramphenicol acetyltransferase reporter genes with expression plasmids of thyroid hormone receptor subtypes. Also, an about 2.5-fold induction of the 5'-deiodinase-promoter-luciferase-reporter construct by all-trans retinoic acid was observed in a cotransfection assay with retinoic acid receptors. Point mutation analysis of the DR+4+2 type hormone-responsive element, however, revealed that it does not alone mediate the retinoic acid effect. The transcription start point of the 5'-deiodinase gene was mapped to nucleotides -23 and -24. No CAAT or TATA box is located within the usual distance to the transcription initiation site. Two GC boxes were found at nucleotides -68 to -63 and -39 to -34. Transfection analysis revealed that the proximal 105 nucleotides in the 5'-flanking region of the 5'-deiodinase gene act as a functional core promoter. This data indicates that triiodothyronine, the end product of thyroid hormone synthesis, positively regulates one of the key enzymes in its production.

Base Sequence↗
PubMed1995

Expression, purification, and characterization of the cGMP-dependent protein kinases I beta and II using the baculovirus system.

Detailed studies of differences in distinct cGMP kinase isoforms are highly dependent on expression of large amounts of these enzyme isoforms that are not easily purified by conventional methods. Here cGMP-dependent protein kinases, the type I beta soluble form from human placenta, and the type II membrane-associated form from rat intestine, were each expressed in a baculovirus/Sf9 cell system and purified in milligram amounts by affinity chromatography. The expressed recombinant proteins displayed characteristics like those of their native counterparts. cGK I beta was expressed as a 76 kDa protein predominantly found in the cytosol fraction, whereas cGK II was expressed as an 86 kDa protein predominantly associated with the membrane fraction. The apparent Ka and Vmax of cGMP for activation of cGK I beta were 0.5 microM and 3.4 mumol/min/mg, and for cGK II were 0.04 microM and 1.8 mumol/min/mg.

Animals↗
PubMed1990

Nebulized heparin and anabolic steroid in the prevention of postoperative deep vein thrombosis following elective abdominal surgery.

One hundred eighty three patients, all over 40 years old, who underwent major abdominal surgery, were randomized into 3 groups: Group I received a single dose of nebulized heparin (800 IU per kg b.w.) administered by inhalation one day prior to surgery. Group II besides the above, also received a single injection of 50 mg of long acting anabolic steroid (nandrolone phenylpropionate) intramuscularly. Group III received 5000 IU heparin subcutaneously on hr prior to surgery as well as every 12 h for the next 5 postoperative days. Postoperatively the patients were evaluated for deep vein thrombosis (DVT) using the 125-I-fibrinogen test. The occurrence of DVT was determined as: in Group I--16%, in Group II--7.9%, in Group III--7.8%. Haemorrhagic complications (clinically important) were observed in 7.8% of patients from Group III, but only in 1.7% of patients in Group I and 1.6% in Group II. For DVT prophylaxis following abdominal surgery a single application of nebulized heparin and long acting anabolic steroid is as effective as conventional low-dose subcutaneous heparin administration, but gives less haemorrhagic complications. This method is also more advantagenous in term of acceptance by the patients and represents considerable saving of nursing time.

Abdomen↗
PubMed1989

[Detection of steroid hormone receptors in patients with mastopathies and fibroadenomas].

Estradiol and progesterone receptors have been determined in 74 women with mastopathy and 33 women with fibroadenomas in the period from 1986-1988. Mastopathy was classified according to Prechtel (stage I-III). A negative steroid-hormon-receptorstatus (less than 10 fmol/mg protein) was predominant in the group with Prechtel I and II. In our study the progesterone receptor was detectable more frequently than the estradiol receptor in patients with mastopathy or fibroadenomas.

Adenofibroma↗
PubMed1989

[Detection and significance of tissue polypeptide antigen (TPA) in breast cancer patients].

20 female with breast cancer aged between 44 and 72 years have been investigated for tissue-polypeptid-antigen (TPA). 20 females without any disorders of the breast were included in our control group. Their age ranged between 22 and 48 years. Patients with breast cancer have been treated by limited-radical-mastectomy according to Auchincloss-Madden followed by axilla dissection and chemotherapy. Cancer has been typed pathohistologically, graded and classified using TNM-nomenclature of maligne tumours. So we can characterize our patients as "pT2N1M0". We estimated TPA preoperativ upto 24 months postoperatively. Our results showed an early and significant increase of TPA in 5 patients suffering a recurrence.

Adult↗
PubMed1988

Absence of a characteristic cell wall lipopolysaccharide in the phototrophic bacterium Chloroflexus aurantiacus.

Two strains of the gliding phototrophic bacterium Chloroflexus aurantiacus were investigated for the presence of lipopolysaccharide (LPS). With both strains, all fractions of hot phenol-water extracts and the extracted cell residues from whole cells or cell homogenates were found to be free from characteristic LPS constituents, such as 3-hydroxy fatty acids, 2-keto-3-deoxyoctonate, heptoses, or O-chain sugars. Phenolchloroform-petroleum ether extracts were also free from precipitable LPS. A lipid A fraction could not be obtained, and there was no hint for glucosamine as a possible lipid A backbone amino sugar. Absence of LPS was confirmed by sodium deoxycholate gel electrophoresis.

Bacteria↗
PubMed1988

Lipopolysaccharides of Thiocystis violacea, Thiocapsa pfennigii, and Chromatium tepidum, species of the family Chromatiaceae.

The lipopolysaccharides (LPS) of three species of purple sulfur bacteria (Chromatiaceae), Thiocystis violacea, Thiocapsa pfennigii, and the moderately thermophilic bacterium Chromatium tepidum, were isolated. The LPS of Thiocystis violacea and Chromatium tepidum contained typical O-specific sugars, indicating O-chains. Long O-chains were confirmed for these species by sodium deoxycholate gel electrophoresis of their LPS. Thiocapsa pfennigii, however, had short or no O-chains. The core region of the LPS of all three species comprised D-glycero-D-mannoheptose as the only heptose and 2-keto-3-deoxyoctonate. The lipid A, obtained from the LPS by mild acid hydrolysis, contained glucosamine as the main amino sugar. Amide-bound 3-hydroxymyristic acid was the only hydroxy fatty acid. The main ester-bound fatty acid in all lipid A fractions was 12:0. Mannose and small amounts of 2,3-diamino-2,3-dideoxy-D-glucose were common constituents of the lipid A of the three Chromatiaceae species investigated. All lipid A fractions were essentially free of phosphate.

Chromatiaceae↗
PubMed1988

[GnRH-TRH stimulation tests in patients with mastopathy].

20 eumenorrhoic patients with clinical manifest mastopathie and biphasic basal body temperature curve were investigated with GnRH-TRH stimulation tests. The tests were carried out in the early/middle follicular phase (13 patients, 3rd to 8th day) of cycle and in the corpus luteum phase (7 patients, 20th to 24th day) of cycle. Compared with the normal level our results showed a significant increase of the basic prolactin secretion. In response to the TRH stimulation 3 females had an excessive PRL answer. There were no deviations of other evaluated hormonal parameters from the normal range of healthy females.

Adolescent↗