Search PubMed⌕ Search

Biomedical subjects

M Krause

Publications and source records attributed to M Krause.

At least 217 records · Page 12Linked to original sources
PubMed1990

Correlation between the presence of sequences homologous to the vir region of Salmonella dublin plasmid pSDL2 and the virulence of twenty-two Salmonella serotypes in mice.

Large plasmids encoding important virulence properties have been found in several Salmonella serotypes. We have studied the relationship between the presence of a highly conserved 4-kilobase (kb) EcoRI fragment from the plasmid virulence region and pathogenicity for mice of 53 isolates representing 22 serotypes of Salmonella. Only strains possessing the homologous 4-kb region were virulent for mice. In addition, we transferred the virulence plasmid from S. dublin into nine different serotypes, including S. typhi and S. paratyphi A, that lack a native virulence plasmid. Only S. heidelberg and S. newport were rendered mouse virulent by the introduction of the S. dublin plasmid. This study demonstrates that plasmid-mediated virulence sequences are required for Salmonella virulence in mice, but many strains, including the agents of human typhoid fever, also lack chromosomal genes necessary to produce lethal systemic disease in mice. Since all the major Salmonella strains that are host-adapted to animals carry virulence plasmids, it appears that these plasmids are important in mediating systemic infection in animals and may contribute to septicemic, nontyphoid salmonellosis in humans.

Animals↗
PubMed1990

[Hemorheologic parameters in patients with giant cell arteritis before and after treatment with steroids].

Basic hemorheological parameters like packed cell volume (PCV), plasma viscosity, red cell aggregation, red cell filterability and whole blood viscosity were measured in 18 patients (14 women, aged 75.4 years) with giant cell arteritis before and after treatment with steroids. The patient group was compared to controls (n = 27, age: 69.8 years) with matched age and cardiovascular risc factors. While no changes in red cell aggregation and filterability could be observed plasma viscosity was increased (1.59 +/- 0.14 mm2/s) by about 20%. The typical anemia of patients with giant cell arteritis (PVC: 0.38 +/- 0.05) prevented an increase in whole blood viscosity at high and medium shear rates (6.6 +/- 0.14 cP = mPas at 23/s). After a fortnight of systemic treatment with high doses of steroids the PCV had normalized and plasma viscosity was even lower than in controls. Thus the blood fluidity was improved as shown by a fall in whole blood viscosity (5.5 +/- 0.7 cP = mPas at 23/s). Results showed: (1) increased plasma viscosity probably induced by increased fibrinogen concentration and (2) an improvement in blood fluidity by treatment with steroids. As the plasma viscosity may participate in the deterioration of microcirculation in patients with giant cell arteritis, lowering the fibrinogen may possibly prevent a further decrease in visual acuity during the first few days of steroid treatment.

Aged↗
PubMed1990

[Hypertelorism-hypospadias (BBB) syndrome. 2 additional family studies].

We report on two unrelated families with the hypertelorism-hypospadias (BBB-) syndrome. The male index patients, 3 and 10 months old, respectively, have ocular hypertelorism, cleft lip and palate, high and broad nasal bridge and hypospadias. The patients' mothers, maternal grandmothers and one patient's sister show hypertelorism. In addition, we summarize the characteristics of previously published cases.

Bone Diseases, Developmental↗
PubMed1989

Wild-type and mutant actin genes in Caenorhabditis elegans.

We have sequenced the four actin genes of Caenorhabditis elegans. These four genes encode typical invertebrate actins and are highly homologous, differing from each other by, at most, three amino acid residues. As a first step toward an understanding of the developmental regulation of this gene set we have also sequenced mutant actin genes. The mutant genes were cloned from two independent revertants of a single dominant actin mutant. For both revertants, reversion was accompanied by an actin gene rearrangement. The accumulation of actin mRNA during development in these two revertants is different from that of wild-type animals. We present here a correlation between actin gene structure and expression in wild-type and mutant animals. The results, suggest that co-ordinate regulation of actin genes is not essential for wild-type muscle function. In addition, it appears that changes in the 3' region of at least one of the actin mRNA may affect its steady-state regulation during development.

Actins↗
PubMed1989

Sequence analysis of the complete Caenorhabditis elegans myosin heavy chain gene family.

The sequences of three myosin heavy chain (MHC) genes from Caenorhabditis elegans, myo-1, 2 and 3, are presented. These genes, together with unc-54, comprise the entire nematode sacromeric MHC family. Comparison of nematode MHC sequences and sarcomeric, smooth and non-muscle MHCs from other organisms highlights conserved sequence features of the MHC rod believed to be important for thick filament assembly. These include: conservation of sequence differences between individual 28 amino acid repeats; invariant placements of large aromatic residues, such as tryptophan, in the rod sequences; conservation of "weak spots" in the hydrophobic seam; and conservation of non-uniform charge distributions along the length of the rod. The rod sequences of the body wall isoforms A and B are more closely related to each other than to the pharyngeal isoforms C and D, suggesting that structural constraints have been imposed by their location within the same thick filament. We have also identified the major transcriptional start site for gene unc-54. Surprisingly, there are no TATA or other known transcription factor elements immediately upstream from the unc-54 start site, or in the upstream regions of the other genes of the C. elegans MHC gene family.

Amino Acid Sequence↗
PubMed1989

Gramicidin S biosynthesis operon containing the structural genes grsA and grsB has an open reading frame encoding a protein homologous to fatty acid thioesterases.

The DNA sequence of about 5.9 kilobase pairs (kbp) of the gramicidin S biosynthesis operon (grs) was determined. Three open reading frames were identified; the corresponding genes, called grsT, grsA, and grsB, were found to be organized in one transcriptional unit, not two as previously reported (M. Krause and M. A. Marahiel, J. Bacteriol. 170:4669-4674, 1988). The entire nucleotide sequence of grsA, coding for the 126.663-kilodalton gramicidin S synthetase 1, grsT, encoding a 29.191-kilodalton protein of unknown function, and 732 bp of the 5' end of grsB, encoding the gramicidin S synthetase 2, were determined. A single initiation site of transcription 81 bp upstream of the grsT initiation condon GTG was identified by high-resolution S1 mapping studies. The sequence of the grsA gene product showed a high degree of homology to the tyrocidine synthetase 1 (TycA protein), and that of grsT exhibited a significant degree of homology to vertebrate fatty acid thioesterases.

Amino Acid Sequence↗
PubMed1989

[Parenteral rehydration treatment of acute diarrhea].

Parenteral rehydration is mandatory if dehydration is severe, vomiting and anorexia prevails, peristalsis is abolished or consciousness disturbed. It has the aim to prevent a circulatory collapse, to fill up the deficit and maintain the requirement until oral feeding is restarted. The principles of parenteral rehydration did not change during the last 20 years. Initially a rapid infusion of isotonic Ringer's lactate solution is mandatory, which usually is followed by half isotonic Ringer's glucose solution. Hypertonic dehydration should be rehydrated very carefully and slowly. During 1976-1986 212 infants and children with severe dehydration were parenterally rehydrated in the Children's Hospital of Medical School Hannover. Dehydration was isotonic in 65.7%, hypertonic in 20.7%, and hypotonic in 13.6%. The parenteral rehydration lasted from 1 to 7 days and was longer necessary in the hypertonic and hypotonic than isotonic states. 4 infants with hypertonic dehydration showed cerebral complications, and 2 of them died. All other patients recovered quickly without acute sequelae.

Child, Preschool↗
PubMed1988

[Kaposi's sarcoma following kidney transplantation: remission following reduction of immunosuppression and consequent HIV infection].

Kaposi's sarcoma (KS) in renal allograft recipients is a rare though serious complication of immunosuppressive treatment. Therapeutic procedures such as surgical excision and local irradiation are inappropriate, since the endothelial-originated tumor is often multicentric. However, systemic treatment such as chemotherapy entails further immunosuppression. We observed a patient with renal allograft who developed disseminated KS of legs and trunk while receiving azathioprine, cyclosporin and prednisone after intensive rejection therapy with high dose corticosteroids, antithymocyte globulin and transplant irradiation. At that time the immunological status was similar to that of an AIDS patient, though HIV serology was negative. Azathioprine was withdrawn while cyclosporin and prednisone were continued. KS disappeared shortly after without a decrease in allograft function, and immunological parameters tended to normalize. When KS had disappeared almost completely the patient became infected with HIV. Complete remission was not hampered, nor was there recurrence of KS. The late appearance of HIV-antigenemia with seroconversion in the course of the tumor makes HIV unlikely as a causative factor. The predisposing factors for KS after renal transplantation are discussed: 1. Amplification of immunosuppression due to rejection therapy, 2. Genetic predisposition such as HLA DR5 antigen, 3. Cytomegalovirus infections. For therapy of iatrogenic KS we propose reduction of immunosuppressive therapy before additional chemotherapy is initiated.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Phaeochromocytoma without symptoms: desensitization of the alpha- and beta-adrenoceptors.

A 16-year-old boy is described who had a relapse of a phaeochromocytoma 6 years after an initially successful tumour resection. The relapse was suspected after routine testing of urinary catecholamine excretion and was confirmed by scintigraphy with 123I-meta-iodobenzylguanidine, computed tomography and magnetic resonance imaging. The plasma norepinephrine level was 3082 pg/ml (normal less than 500 pg/ml); the plasma epinephrine level was in the normal range. Surprisingly, our patient had no symptoms, including hypertension. The density of the alpha- and beta-adrenoceptors on circulating blood cells was decreased. Postoperatively the plasma catecholamine levels were in the normal range. Three months after surgery the adrenoceptor density was almost normal. We conclude that the absence of clinical symptoms was probably due to desensitization of the adrenoceptors. After a successful operation to treat phaeochromocytoma, long-term monitoring of catecholamines is necessary to rule out an asymptomatic relapse.

Adolescent↗
PubMed1988

Organization of the biosynthesis genes for the peptide antibiotic gramicidin S.

A recombinant bacteriophage containing the intact Bacillus brevis gene for gramicidin S synthetase 1, grsA, and the 5' end of the gramicidin S synthetase 2 gene, grsB, was identified by screening an EMBL3 library with anti-GrsA antibodies. This clone, EMBL315, has a 14-kilobase (kb) insert that hybridizes to the previously isolated 3.9-kb fragment of the grsB gene, which encodes the 155-kilodalton ornithine-activating domain of gramicidin S synthetase 2. Deletion and subcloning experiments with the 14-kb insert located the grsA structural gene and its putative promoter on a 4.5-kb PvuII fragment which encoded the full-length 120-kilodalton protein in Escherichia coli. In addition, hybridization analysis revealed that the 5' end of the grsB gene is located approximately 3 kb from the grsA structural gene. Furthermore, these studies indicated that grsA and grsB are transcribed in opposite orientations.

Amino Acid Isomerases↗
PubMed1987

A trans-spliced leader sequence on actin mRNA in C. elegans.

While determining the 5' ends of C. elegans actin mRNAs, we have discovered a 22 nucleotide spliced leader sequence. The leader sequence is found on mRNA from three of the four nematode actin genes. The leader also appears to be present on some, but not all, nonactin mRNAs. The actin mRNA leader sequence is identical to the first 22 nucleotides of a novel 100 nucleotide RNA transcribed adjacent, and in the opposite orientation, to the 5S ribosomal gene. The evidence suggests that the actin mRNA leader sequence is acquired from this novel nucleotide transcript by an intermolecular trans-splicing mechanism.

Actins↗
PubMed1987

Localization of small RNAs hybridizable to a B2 clone in the nuclear fraction of mouse cell lines.

An RNA polymerase III transcript, 7SK nuclear RNA, was found to bear sequence homology to the B2 class of highly repeated elements in the mouse genome. Northern blot hybridizations between the small RNAs and two B2 clones showed that only one of them (p49C8) hybridized to 7SK RNA. Both clones, however, hybridized to 4.5SI RNA as well as to a third class of nuclear RNA transcripts around 170 nucleotides long, whose levels were found to be greatly increased upon induction of transformation in a mouse 3T3 cell line transformed with a temperature-sensitive mutant of simian virus 40.

Animals↗