Search PubMed⌕ Search

Biomedical subjects

F Suter

Publications and source records attributed to F Suter.

At least 73 records · Page 4Linked to original sources

Teicoplanin in the therapy of staphylococcal neuroshunt infections.

Three patients with staphylococcal infection of neuroshunt, two with ventriculoperitoneal and one with external ventricular derivation, were treated with teicoplanin given intravenously (iv) or intraventricularly (ivt), two patients were adults, while the third was an infant. The causative organisms were methicillin-sensitive Staphylococcus epidermidis (MSSE) in the first two cases and methicillin-sensitive Staphylococcus aureus (MSSA) in the paediatric patient. Patient No. 1 was given teicoplanin iv (400 mg/day) and subsequently ivt (20 mg/day). CSF teicoplanin levels were always below 1 microgram/ml during the first part of the treatment; after the institution of ivt therapy, drug levels ranged from 20 to 35 micrograms/ml (mean 26.4). The patient was cured after 20 days of a combination treatment (ivt teicoplanin plus rifampin, 900 mg/day, iv). Patient No. 2 was given teicoplanin 400 mg/day, iv, for two weeks; its low levels in CSF (always below 0.5 microgram/ml) accounted for the failure to eradicate the MSSE. A new regimen with teicoplanin, 20 mg/day plus netilmycin, 15 mg/day, both ivt, cured the patient in two weeks. Teicoplanin levels in the CSF ranged from 12.5 to 33 micrograms/ml (mean 18.3). Patient No. 3, an 8-month-old infant, was placed on teicoplanin, 5 mg/day ivt plus chloramphenicol, 180 mg/day iv, after several other antibiotic trials had failed to eradicated a MSSA infection of his external ventricular derivation. The therapy cleared the infection in one week (CSF teicoplanin levels: 30 to 38, mean 34 micrograms/ml). Teicoplanin (iv or ivt) was well tolerated without any significant side-effects; its role in the treatment of staphylococcal neuroshunt infections deserves further studies.

Adolescent↗

Percutaneous interstitial chemotherapy of a small hepatocellular carcinoma under ultrasound guidance.

A small (less than 3 cm) inoperable hepatocellular carcinoma was treated with percutaneous interstitial chemotherapy (PIC). 5-Fluorouracil was injected by a fine needle under ultrasound guidance. After 3 months a fine needle biopsy (FNB) yielded fibronecrotic material. After 18 months another FNB yielded steatosis and dysplastic cells and the lesion showed no increase in size. PIC could be an interesting alternative treatment for small tumors unresponsive to conventional therapies.

Administration, Cutaneous↗

Linker polypeptides of the phycobilisome from the cyanobacterium Mastigocladus laminosus. I. Isolation and characterization of phycobiliprotein-linker-polypeptide complexes.

Phycobilisomes from the cyanobacterium Mastigocladus laminosus cultured in white and red light were isolated and compared with respect to the phycoerythrocyanin (PEC) and linker polypeptide contents. It was verified that the production of PEC is induced by low light intensities. A PEC complex, (alpha PEC beta PEC)6LR34.5,PEC, and a phycocyanin (PC) complex, (alpha PC beta PC)6LR34.5,PC, were isolated from phycobilisomes by Cellex-D anion exchange chromatography and sucrose density gradient centrifugation. The absorption and fluorescence emission maxima of the PEC complex are at 575 and 620 nm and those of the PC complex are at 631 and 647 nm, respectively. The extinction coefficients of the two complexes were determined. From different experiments it was concluded that PEC is present as a hexameric complex, (alpha PEC beta PEC)6LR34.5,PEC, in the phycobilisome. The two linker polypeptides LR34.5,PEC and LR34.5,PC were isolated from their phycobiliprotein complexes by gel filtration on Bio-Gel P-100 in 50% formic acid. A 5-kDa terminal segment of both linker polypeptides was found to influence the hexamer formation of the phycobiliproteins. The same segments have been described to be responsible for the hexamer-hexamer linkage (Yu, M.-H. & Glazer, A.N. (1982) J. Biol. Chem. 257, 3429-3433). A 8.9-kDa linker polypeptide, LR(C)8.9, was isolated from a PEC fraction of the Cellex-D column by Bio-Gel P-100 gel filtration in 50% formic acid. Localisation of this protein within the phycobilisome was attempted. Its most probable function is to terminate the phycobilisomal rods at the end distal to the allophycocyanin core.

Bacterial Proteins↗

Linker polypeptides of the phycobilisome from the cyanobacterium Mastigocladus laminosus. II. Amino-acid sequences and functions.

The complete primary structure of an 80-residue linker polypeptide, LR(C)8.9, from the phycobilisome of the cyanobacterium Mastigocladus laminosus was determined as well as the 44 N-terminal residues of the two linker polypeptides LR34.5,PEC and LR34.5,PC and the 114 C-terminal residues of LR34.5,PEC. A brief description of the structure determination and an extensive discussion of the relationships of these polypeptides have been published recently (Füglistaller, P., Suter, F. & Zuber, H. (1985) Biol. Chem. Hoppe-Seyler 366, 993-1001). In this paper we report in detail about the elucidation of the primary structures. Limited digestion of the hexameric phycobiliprotein-linker polypeptide complex (alpha PEC beta PEC)6LR34.5,PEC with various proteases resulted in a linker polypeptide diminished by a 1-5 kDa segment, while the phycobiliproteins remained intact. By N-terminal sequence analysis of the residual part of the linker polypeptide in the complex, LR34.5-5,PEC, it was concluded that the C-terminus of the polypeptide had been attacked by the proteases. This C-terminal part of the protein influences the hexamer formation of phycoerythrocyanin (PEC) and is responsible for the linkage between two phycobiliprotein hexamers. From the function of the C-terminal segment of LR34.5,PEC and its homology to the LR(C)8.9 polypeptide, it was concluded that LR(C)8.9 is located at the end of the peripheral phycobilisomal rods distal to the allophycocyanin core.

Amino Acid Sequence↗

The primary structure of Bacillus cereus neutral proteinase and comparison with thermolysin and Bacillus subtilis neutral proteinase.

The complete amino-acid sequence of a neutral proteinase, produced by Bacillus cereus, was determined by protein sequencing. The neutral proteinase consists of 317 amino-acid residues. The primary structure is 70% homologous to thermolysin, a thermostable neutral proteinase and 45% homologous to Bacillus subtilis neutral proteinase. The zinc-binding site and the hydrophobic pocket of the active site are highly similar in all three proteinases. B. cereus neutral proteinase which is 20 degrees C less thermostable (60 degrees C) than thermolysin (80 degrees C) shows only minor differences in calcium binding sites and salt bridges compared to thermolysin (known from its X-ray diffraction analysis), whereas B. subtilis neutral proteinase (50 degrees C) differs considerably. Therefore it was assumed that the difference in thermostability between B. cereus neutral proteinase and thermolysin is not caused by different metal binding properties, or differences in the active site, but by changes within the rest of the molecule. Calculation of secondary structure potentials according to Chou & Fasman, hydrophobicity and bulkiness of the different structural elements and preferred cold----hot amino-acid residue exchanges indicated, that the thermostability of thermolysin compared to B. cereus neutral proteinase is caused by small effects contributed by numerous amino-acid exchanges distributed over the whole molecule, resulting in increased hydrophobicity of beta-pleated sheet and higher bulkiness of alpha-helical regions.

Amino Acid Sequence↗

Complete amino acid sequence of the B875 light-harvesting protein of Rhodopseudomonas sphaeroides strain 2.4.1. Comparison with R26.1 carotenoidless-mutant strain.

The complete amino acid sequence was determined for the alpha- and beta-chains of the B875 light-harvesting protein purified from photosynthetic membranes of Rhodopseudomonas sphaeroides 2.4.1. The sequence of the B875-alpha-polypeptide was identical to that reported for the R26.1 carotenoidless mutant [(1985) Biochim. Biophys. Acta 806, 185-186] and contained 58 amino acid residues with a blocked methionine and a glutamic acid at the N- and C-termini, respectively. The B875-beta-polypeptide contained 48 amino acid residues with alanine and phenylalanine as respective N- and C-termini; although otherwise identical, the leucine at position 29 in the wild-type strain was replaced by proline in the mutant. This radical amino acid substitution occurred within the central hydrophobic domain of the beta-polypeptide chain and is thought to result in a weakening of the structure of the alpha/beta heterodimer since it was not possible to isolate the intact pigment-protein complex from the R26.1 mutant strain.

Amino Acid Sequence↗

Tissue distribution and ultrastructure of B lymphocytes reacting with the monoclonal antibody anti-Y29/55.

The reactivity of normal tonsilar cells with the monoclonal antibody anti-Y29/55 is characterized at the tissue and ultrastructural cytological level. Using an indirect immuno-alkaline phosphatase method on frozen sections the antibody labels mantle zone and germinal center lymphocytes. This staining reaction is more generalized in B-lymphocyte areas than that obtained with antibodies to IgM and IgD. By indirect immunoperoxidase staining, as well as by an indirect rosetting procedure in cell suspensions, the reactive cell population were either small resting lymphocytes or activated lymphocytes corresponding to centrocytes, centroblasts, immunoblasts and plasmoblasts; some plasma cells were also labeled. These results characterize the monoclonal antibody anti-Y29/55 as a pan-B-marker antibody, useful for labeling resting and activated peripheral B-lymphocytes in frozen tissue sections and cell suspensions.

Animals↗

Purification, amino-acid sequence and some properties of the ferredoxin isolated from Bacillus acidocaldarius.

Ferredoxin was isolated from the aerobic, thermophilic and acidophilic bacterium Bacillus acidocaldarius and its sequence of 78 amino acids completely determined by automated Edman degradation of the protein and of peptides derived from chemical cleavage between aspartic acid and proline and from enzymatic digestions. The optical spectrum of the oxidized protein has a broad maximum around 400 nm. The ferredoxin is thermostable: its absorbance begins to decrease only at incubation over 71 degrees C. The number of iron and inorganic sulphur atoms per molecule was determined to be 5.3 and 5.0, respectively. The calculated molar extinction coefficient was 23 000 M-1 X cm-1, the molecular mass of the apoferredoxin 8 872 Da. Contrary to all expectations, the sequence of B. acidocaldarius ferredoxin shows very little homology to that of B. stearothermophilus but closely resembles that of Thermus thermophilus.

Amino Acid Sequence↗

Structural studies on cryptomonad biliprotein subunits. Two different alpha-subunits in Chroomonas phycocyanin-645 and Cryptomonas phycoerythrin-545.

The N-terminal amino-acid sequences of two green alpha-subunit fractions from Chroomonas phycocyanin-645 and from two violet alpha-subunit fractions from Cryptomonas phycoerythrin-545 reveal that these cryptomonad biliproteins each contain two different alpha-subunits. The chromophore binding sites at the cysteine residues in positions 18 or 19 are homologous to the chromophore binding site at cysteine position 84 in cyanobacterial biliproteins. The sequence homologies of the beta-subunits to cyanobacterial biliproteins are higher than those of the alpha-subunits. Cryptomonas phycoerythrin-545 alpha-subunits contain a gamma-hydroxylysine residue at the fourth position of the polypeptide chains. 50%-75% of the total sequence of the alpha-subunits was determined by N-terminal amino-acid sequence analysis. The alpha-subunits of the Cryptomonad biliproteins are smaller than the alpha-subunits of the cyanobacterial biliproteins. Comparing sequence homologies we found 60 amino-acid residues less at the N-terminus of Cryptomonad biliproteins than in cyanobacterial biliproteins.

Amino Acid Sequence↗

The light-harvesting polypeptides of Rhodopseudomonas viridis. The complete amino-acid sequences of B1015-alpha, B1015-beta and B1015-gamma.

Three low molecular mass polypeptides have been isolated by using the technique of organic solvent extraction of thylakoid membranes or whole cells from Rhodopseudomonas viridis. Their primary structures were determined by long liquid phase sequencer runs, combined with the isolation and sequence analysis of the C-terminal o-iodosobenzoic acid fragment and carboxypeptidase degradation. The polypeptide which consists of 58 amino-acids and is 46% homologous to the antenna polypeptide B880-alpha from Rhodospirillum rubrum was designated as B1015-alpha (1 His residue). The sequence homology between the second polypeptide, named B1015-beta (55 amino acids, 2 His residues) and B880-beta from Rs. rubrum is 52%. For the third polypeptide consisting of 36 amino acids and exhibiting a high hydrophobicity, no equivalent polypeptide has so far been found in other purple bacteria. The molar ratio of these three organic solvent soluble polypeptides from Rp. viridis was estimated to be 1:1:1. Accordingly, the 36 amino-acid polypeptide is likely to be an additional constituent of the light-harvesting complex B1015, consequently termed as B1015-gamma. According to hydrophathy profiles, the transmembrane arrangement of B1015-alpha and B1015-beta within the thylakoid membrane is supposed to be similar. B1015-gamma, however, shows a somewhat different hydropathy profile. A particular feature of this polypeptide is its high amount of aromatic amino acids. It is postulated that B1015-gamma is involved in the formation of regular arrays of light-harvesting complexes.

Amino Acid Sequence↗

Linker polypeptides of the phycobilisome from the cyanobacterium Mastigocladus laminosus: amino-acid sequences and relationships.

Three linker polypeptides of the phycobilisome from the cyanobacterium Mastigocladus laminosus were isolated: A 8.9-kDa polypeptide, L8.9R(C), which is probably associated with C-phycocyanin, a 34.5-kDa polypeptide, L34.5,PCR, which forms a complex with C-phycocyanin, and a 34.5-kDa polypeptide, L34.5,PECR, which is linked to phycoerythrocyanin. The complete amino-acid sequence (80 residues) of the L8.9R(C) polypeptide was determined as well as the N-terminal 44 residues of both L34.5R polypeptides and the 114 C-terminal residues of L34.5,PECR. L8.9R(C) is homologous to L8.9C (Füglistaller et al. (1984) Hoppe-Seyler's Z. Physiol. Chem. 365, 1085-1096) and to the C-terminal sequence of L34.5,PECR. The N-terminal sequences of L34.5,PECR and L34.5,PCR exhibit 34% homology. The 44 N-terminal residues of L34.5,PECR are related to the beta-subunit of phycoerythrocyanin (23% homology), while the C-terminal sequence of L34.5,PECR is more related to alpha PEC (21% homology within 60 residues). This suggests that the 30-kDa-linker polypeptide family originates from a fusion of the alpha- and beta-subunit genes and the corresponding intercistronic DNA sequence, as might have arisen through mutation in the stop-codon of the beta-subunit gene. Hence, all polypeptides of the phycobilisome (including perhaps the anchor polypeptide) may be derived from an early ancestor phycobiliprotein subunit, which itself is also related to myoglobin (Schirmer et al. (1985) J. Mol. Biol. 184, 251-277).

Amino Acid Sequence↗

Ceftazidime in the therapy of pseudomonal meningitis.

In this study we report about the efficacy and tolerability of ceftazidime in the treatment of 10 cases of pseudomonal meningitis (nine Pseudomonas aeruginosa and one Pseudomonas cepacia). The 10 patients had a pseudomonal infection of the central nervous system (CNS) complicating neurosurgical procedures or developed on a preexisting immunodepressing condition; four patients were of pediatric age. All isolates were sensitive to ceftazidime with MICs ranging from 0.39 to 3.12 micrograms/ml. Ceftazidime was given intravenously at the dosage of 100-150 mg/kg/day. In seven cases amikacin was associated by intralumbar or intraventricular instillation. The duration of ceftazidime treatment ranged from 9 to 49 days with a mean of 22.2. Eight cases out of ten were cured bacteriologically and clinically, while the remaining two were cured after treatment with other antibiotics. Concentrations of ceftazidime in serum and in lumbar and/or ventricular cerebrospinal fluid (CSF) were obtained in four cases; the mean concentration in lumbar CSF was 12.2 micrograms/ml and in ventricular 3.3 micrograms/ml. The study demonstrated that ceftazidime is effective in the treatment of Pseudomonal meningitis.

Adolescent↗

In utero sonographic diagnosis of semilobar holoprosencephaly.

Since its early diagnostic application in the study of pregnancy, ultrasonography (US) has been widely employed in the detection of fetal malformations. Head abnormalities, recognized through the evaluation of brain and skull structures, accounted for the majority of these observations. We report here on a case of holoprosencephaly, a rare malformation (incidence is around 1/16,000 live births according to Roach et al. [1975]) diagnosed and monitored up to delivery by multiple US examinations.

Adult↗

Isolation and complete amino-acid sequence of the small polypeptide from light-harvesting pigment-protein complex I (B870) of Rhodopseudomonas capsulata.

The small bacteriochlorophyll-binding polypeptide of the light-harvesting complex B870 was extracted from the intracytoplasmic membrane of the strain A1a+ of Rhodopseudomonas capsulata with chloroform/methanol/ammonium acetate and separated by chromatography on Sephadex LH60 using the same solvent. The polypeptide obtained from the peak fraction III was found to be homogeneous and identical with the small polypeptide isolated from the B870 complex as shown by dodecyl sulfate/polyacrylamide gel electrophoresis, amino acid composition and N-terminal sequence. The complete amino acid sequence is given. The relative molecular mass based on the amino acid sequence is 5341. The polarity of amino acids is 35.42%. The C-terminal part of the peptide chain from residue 29 to 48 is hydrophobic and includes one His residue.

Amino Acid Sequence↗

Rifampicin in collections of pus--a kinetic study in human abscesses.

Most of the successful non-surgical management of abdominal abscesses is based upon the presence of therapeutic amounts of effective antibiotics within the collection. However few data are currently available concerning antimicrobial levels in human purulent lesions. To study the relationship between serum and pus concentrations of rifampicin, 11 patients with deep-seated abscesses were given 900 mg intravenously of rifampicin daily; after 3, 8 and 20 h from injection, an ultrasound-guided percutaneous aspiration of the collection was performed. Samples were obtained on the first day of therapy in six cases, while in other six the aspiration took place on the third day. Rifampicin levels of therapeutic value were present after 8 h from the first injection. From this time antibiotic amounts in pus, ranging from 1.6 to 5.8 mg/l, were consistent with a long persistence of rifampicin in abscesses, without any evidence of accumulation.

Abscess↗

Management of staphylococcal endocarditis in drug addicts. Combined therapy with oral rifampicin and aminoglycosides.

Staphylococcal endocarditis is a condition affecting intravenous drug abusers at increasing rates, and its treatment is still controversial. We used, successfully, high doses of rifampicin, associated with an aminoglycoside, for the treatment of two heroin addicts. In the first we found a left-sided endocarditis with metastatic abscesses in brain, both kidneys, liver and spleen; in the other the finding of bilateral lung abscesses was related to embolic episodes from a diseased tricuspid valve. Since the isolated strains of Staphylococcus aureus were tolerant to methicillin, we used oral rifampicin (20 mg/kg/day) plus an aminoglycoside (amikacin in the former and gentamicin in the latter), after in-vitro testing had proved these combinations to be effective. We achieved, in both cases stable bactericidal concentrations in the serum and a lasting clinical recovery.

Adult↗

The light-harvesting polypeptides of Rhodospirillum rubrum. I. The amino-acid sequence of the second light-harvestng polypeptide B 880-beta (B 870-beta) of Rhodospirillum rubrum S 1 and the carotenoidless mutant G-9+. carotenoidless mutant G-9+.

The light-harvesting complex B 880 from Rhodospirillum rubrum S 1 (wild type) and B 870 from the carotenoidless mutant G-9+ was shown to consist mainly of an organic solvent-(chloroform/methanol-) soluble and an organic solvent-insoluble polypeptide. The isolation and separation of these two low-molecular-mass polypeptides (Mr 6101 and Mr 6079) were achieved by a two-step extraction procedure of chromatophores using in the first step chloroform/methanol containing 0.1M ammonium acetate. Following Sephadex LH-60 chromatography of this first extract a light-harvesting polypeptide (B 870-alpha) was isolated and its complete amino acid sequence was determined (R. Brunisholz et al. (1981) FEBS Lett. 129/1, 150-154, B 880-alpha: G. Gogel et al. (1983) Biochim. Biophys. Acta 746, 32-39). Upon reextraction of the chromatophore pellet with chloroform/methanol/ammonium acetate containing in addition acetic acid a second low-molecular-mass polypeptide (B 880-beta of B 870-beta) was generated. The complete amino acid sequences of the chloroform/methanol-insoluble light-harvesting polypeptide of Rs. rubrum S 1 (B 880-beta) and of Rs. rubrum G-9+ (B 870-beta) were determined. They are identical and consist of 54 amino acid residues. The conserved histidine residue within the hydrophobic stretch raises more evidence for ligand complexation of bacteriochlorophyll to this specific histidine residue which therefore possibly plays the key role in pigment-protein interactions. Both polypeptides (B 880-alpha and B 880-beta) are part of the light-harvesting complex B 880 in an apparent ratio of 1:1. Based on the primary structure data a possible arrangement of both light-harvesting polypeptides within the membrane will be discussed.

Amino Acid Sequence↗

The light-harvesting polypeptides of Rhodospirillum rubrum. II. Localisation of the amino-terminal regions of the light-harvesting polypeptides B 870-alpha and B 870-beta and the reaction-centre subunit L at the cytoplasmic side of the photosynthetic membrane of Rhodospirillum rubrum G-9+.

The unspecific proteinase K and the specific proteases alpha-chymotrypsin, trypsin and S. aureus V 8 protease were used in order to determine the orientation of the polypeptides B 870-alpha and B 870-beta from the major antenna complex B 870 of Rs. rubrum G-9+ within the chromatophore membrane (inside-out vesicle). Although B 870-alpha exhibits cleavable peptide bonds, treatment with specific proteases yielded splitting only in B 870-beta within the N-terminal region. In the case of proteinase K, which was most effective, mainly 6 (B 870-alpha) and 16 (B 870-beta) amino acid residues were removed from their N-terminal parts as proved by means of Edman degradation of cleavage products. The major peptide bonds cleaved were identified as Gln6-Leu7 in B 870-alpha and as Lys16-Glu17 in B 870-beta. The central hydrophobic stretch regions and the relatively hydrophilic C-terminal parts of both light-harvesting polypeptides were not affected by proteinase K. On the basis of these degradation experiments a transmembrane orientation of B 870-alpha and B 870-beta is postulated, with their N-terminal towards the cytoplasm and their C-termini towards periplasm with regard to the photosynthetic membrane. This hypothesis is supported by the transmembrane model proposed by Brunisholz et al. (Hoppe-Seyler's Z., Physiol. Chem., (1984) 365, 675-688) in which the hydrophobic stretch of B 870-alpha and of B 870-beta forming an alpha-helix would span the membrane once. Organic solvent extraction of chromatophores treated with proteinase K yielded a fairly pure polypeptide fragment with an apparent molecular mass of 14000 Da. Its N-terminal amino-acid sequence is identical with the sequence within the N-terminal region of the reaction centre subunit L of Rs. rubrum G-9+. Thus it is most likely that as in the case of B 870-beta, proteinase K removed 16 amino acid residues from the N-terminal part of subunit L. This subunit therefore also seems to be exposed at the surface of the cytoplasmic side of the chromatophore membrane.

Amino Acids↗