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T Krafft

Publications and source records attributed to T Krafft.

At least 19 recordsLinked to original sources
PubMed2003

[Comparison of the emergency medical services systems of Birmingham and Bonn: process efficacy and cost effectiveness].

OBJECTIVE: Due to rising health care costs there is a need to verify that the treatment by Emergency Medical Services (EMS) systems is efficient and cost effective. The integration of emergency physicians is inherent part of out-of-hospital emergency care and regulated by law in Germany but not in England and the United States of America. Aim of this study therefore was to conduct a cost performance analysis by evaluating the underlying structure, the costs incurred and the achieved performance in two EMS systems with paramedics or emergency physicians on scene. METHODS: The study was carried out in West-Birmingham, a part of the West-Midlands-Ambulance-Service (WMAS), and the EMS of Bonn. Pre defined questionnaires, EMS protocols, calculations of purchasing power parity and recent publications concerning out-of-hospital resuscitation (CPR) were used to evaluate the operating costs, to describe the structure and to measure the quality of performance. Significance was assumed at p < 0.01 for CHI(2)- or t-test, respectively. RESULTS: Birmingham used state of the art technology for dispatch and logistics whereas Bonn trusted in high qualified personnel. In the 1st quarter 1997 the Mainz-Emergency-Evaluation Score could be achieved before (MEES A) and after preclinical treatment (MEES B) in 3502 and 3422 patients in Birmingham and Bonn, respectively. In Birmingham 7.5 % and in Bonn 17 % of all patients could be improved by the EMS treatment, respectively (p < 0.01). Looking at severely ill patients (MEES A < 22) the EMS in West-Birmingham achieved an improvement in 27.9 % of these patients with an averaged change in MEES of 0.9 +/- 1.7 points in all of them. In contrast the Bonn EMS improved the status in 47.8 % of these patients and MEES A could be improved considerably by 2.3 +/- 3.4 points (p < 0.01). Pharmacological treatment was less frequently used in Birmingham than in Bonn (12.9 % vs. 32.4 %, respectively; p < 0.01). At equal incidences of CPR attempts discharge rate after CPR was only 4 % in WMAS compared to 14.7 % in Bonn-North (p < 0.01). Per inhabitant and year total costs amounted to 10.43 euro for the EMS system in Birmingham, which is 42 % less than in Bonn. Unit hour utilisation reached 0.6 in Birmingham and only 0.33 in Bonn. In severely ill patients the improvement of MEES A by 0.1 points cost per inhabitant and year 1.16 euro in Birmingham and only 0.65 euro in Bonn. The survival of one patient after CPR was calculated to 0.7 euro in Birmingham and 0.17 euro in Bonn. CONCLUSIONS: The provider of the EMS in West-Birmingham--WMAS--organised a reliable system with high efficiency concerning unit hour utilisation and response time reliability. In the EMS of Bonn, in contrast, the complex therapy by the emergency physicians improved MEES considerably and increased probability of survival after CPR at a higher level of efficiency. Further investigations however are necessary to evaluate the presented parameter of efficiency.

Allied Health Personnel↗
PubMed2000

Cloning and sequencing of the genes encoding the periplasmic-cytochrome B-containing selenate reductase of Thauera selenatis.

The periplasmic selenate reductase (Ser) of Thauera selennatis is a component of the electron transport chain catalyzing selenate reduction with acetate as the electron donor (i.e., selenate respiration). The purified enzyme consists of three subunits (SerA, SerB and SerC). Using transposon (i.e., Tn5) mutagenesis selenate reductase mutants were isolated. Junction fragments of DNA adjacent to the integrated Tn5 were used, together with oligonucleotides derived from the N-termini of SerA and SerB, to clone from a gene bank a DNA fragment that contained the corresponding genes. After sequencing, serA, serB and serC were identified by sequence comparison with the N-termini of the three subunits. The genes are arranged in the order serA, serB, serC; a fourth open reading frame (serD) in between, but overlapping serB and serC, is also present. The serA gene product contains an apparent leader peptide with a twin-arginine motif. The remainder of the translated amino acid sequence is similar to that of a number of prokaryotic molybdenum-containing enzymes (e.g., nitrate reductases and formate dehydrogenases of Escherichia coli). The serB gene product contains four cysteine clusters and is similar to various iron-sulfur protein subunits. The serC gene product contains a putative Sec-dependent leader peptide, but there are no similarities between the remainder of the translated protein and other protein subunits. The SerC contains two histidine and four methionine residues, and these may noncovalently bind heme b--which is a component of the active selenate reductase. The serD gene product encodes a putative protein that shows no significant sequence similarities to other proteins. However, the location of the serD within the other ser genes is similar to that of narJ within the E. coli narGHJI operon (nitrate reductase A); thus suggesting that the role of SerD may be similar to that of NarJ, which is a system-specific chaperone protein.

Amino Acid Sequence↗
PubMed1999

Mutational analysis of the follicle-stimulating hormone (FSH) receptor in normal and infertile men: identification and characterization of two discrete FSH receptor isoforms.

In a search for pathophysiological causes of idiopathic male infertility we investigated the occurrence of mutations of the FSH receptor in 48 men with this disorder. The entire FSH receptor gene was analyzed by single stranded conformation polymorphism analysis (SSCP). A heterozygous point mutation without functional consequences, exchanging Val to Ala in codon 341, was found in one patient. SSCP analysis led to the identification of 2 polymorphisms in exon 10 associated in 2 discrete FSH receptor allelic variants, i.e. Thr307-Asn680 and Ala307-Ser680. The frequency and distribution of the two allelic variants was further analyzed in 86 proven fathers and 75 infertile men by SSCP (codon 307) and restriction fragment length polymorphism (codon 680). The 2 receptor isoforms showed similar Mendelian distribution in proven fathers and in infertile men. Serum FSH, inhibin B, and combined testicular volume did not differ between subjects with different receptor isoforms. Binding studies in transiently transfected COS-7 cells showed similar binding affinity for the two receptor variants. Moreover, the Ala307-Ser680 and the Thr307-Asn680 FSH receptors responded in vitro to FSH with comparable cAMP production. These data suggest that different isoforms of the FSH receptor with similar functional properties exist in normal and infertile men. We conclude that mutations of the FSH receptor or the FSH receptor genotype do not play a pathogenic role in male idiopathic infertility. The possibility that different FSH isoforms might interact differently with the 2 receptor variants remains to be investigated.

Animals↗
PubMed1998

Purification and characterization of the respiratory arsenate reductase of Chrysiogenes arsenatis.

Chrysiogenes arsenatis is the only bacterium known that respires anaerobically using arsenate as the terminal electron acceptor and the respiratory substrate acetate as the electron donor. During growth, the arsenate is reduced to arsenite; the reduction is catalyzed by an arsenate reductase. This study describes the purification and characterization of a respiratory arsenate reductase (Arr). The enzyme consists of two subunits with molecular masses of 87 kDa (ArrA) and 29 kDa (ArrB), and is a heterodimer alpha1beta1 with a native molecular mass of 123 kDa. The arsenate reductase contains molybdenum, iron, acid-labile sulfur and zinc as cofactor constituents. The Km of the enzyme for arsenate is 0.3 mM and the Vmax is 7013 micromol arsenate reduced x min(-1) x mg protein(-1). Nitrate, sulfate, selenate and fumarate cannot serve as alternative electron acceptors for the arsenate reductase. Synthesis of the protein is regulated, as arsenate must be present during growth for the enzyme to be fully induced. The N-terminus of ArrA is similar to a number of procaryotic molybdenum-containing polypeptides (e.g. the formate dehydrogenases H and N of Escherichia coli). The N-terminus of ArrB is similar to iron-sulfur proteins. The respiratory arsenate reductase of C. arsenatis is different from the non-respiratory arsenate reductases of E. coli and Staphylococcus aureus.

Adenosine Triphosphatases↗
PubMed1997

Purification and characterization of the selenate reductase from Thauera selenatis.

Thauera selenatis is one of two isolated bacterial species that can obtain energy by respiring anaerobically with selenate as the terminal electron acceptor. The reduction of selenate to selenite is catalyzed by a selenate reductase, previously shown to be located in the periplasmic space of the cell. This study describes the purification of the enzyme from T. selenatis grown anaerobically with selenate. The enzyme is a trimeric alphabetagamma complex with an apparent Mr of 180,000. The alpha, beta, and gamma subunits are 96 kDa, 40 kDa, and 23 kDa, respectively, in size. The selenate reductase contains molybdenum, iron, and acid-labile sulfur as prosthetic group constituents. UV-visible absorption spectroscopy also revealed the presence of one cytochrome b per alphabetagamma complex. The Km for selenate was determined to be 16 microM, and the Vmax was 40 micromol/min/mg of protein. The enzyme is specific for the reduction of selenate; nitrate, nitrite, chlorate, and sulfate were not reduced at detectable rates. These studies constitute the first description of a selenate reductase, which represents a new class of enzymes. The significance of this enzyme in relation to cell growth and energy generation is discussed.

Amino Acid Sequence↗
PubMed1996

Properties of a Wolinella succinogenes mutant lacking periplasmic sulfide dehydrogenase (Sud).

A delta sud deletion mutant of Wolinella succinogenes that lacked the periplasmic sulfide dehydrogenase (Sud) was constructed using homologous recombination. The mutant grew with sulfide and fumarate, indicating that Sud was not a component of the electron transport chain that catalyzed fumarate respiration with sulfide as an electron donor. Likewise, growth with formate and either polysulfide or sulfur was not affected by the deletion. Removal of Sud from wild-type W. succinogenes by spheroplast formation did not decrease the activity of electron transport to polysulfide. The delta psr deletion mutant that lacks polysulfide reductase (Psr) grew by fumarate respiration with sulfide as an electron donor, indicating that Psr is not required for this activity.

Cytochrome c Group↗
PubMed1995

The function of Wolinella succinogenes psr genes in electron transport with polysulphide as the terminal electron acceptor.

The membrane-integrated polysulphide reductase (Psr) of Wolinella succinogenes is part of the electron transport chain catalyzing polysulphide reduction by formate or hydrogen. The isolated enzyme catalyzes sulphide oxidation by dimethylnaphthoquinone. The two hydrophilic subunits, PsrA and PsrB of the enzyme, are encoded by genes that form an apparent operon psrABC together with a third gene. Using homologous recombination, three deletion mutants of W. succinogenes were constructed that lack psrC, psrBC or the whole psr operon. The mutants grown with formate and fumarate were fractionated, and the cell fractions were analyzed for the presence of PsrA and enzyme activity. It was concluded that: (a) polysulphide reductase is a constituent of the wild-type chain catalyzing electron transport from formate to polysulphide; (b) the gene psrC encodes a subunit that anchors the enzyme in the membrane and is required for electron transport; (c) PsrA which probably carries the substrate site, is exposed to the bacterial periplasm; (d) PsrA and PsrB are required for the activity of sulphide oxidation with 2,3-dimethyl-1,4-naphthoquinone. Surprisingly, the delta psrABC mutant could grow with formate and polysulphide. The membrane fraction of the mutant grown under these conditions contained an enzyme that replaced polysulphide reductase in electron transport, and catalyzed sulphide oxidation with 2,3-dimethyl-1,4-naphthoquinone.

Electron Transport↗
PubMed1994

Abrasion of surface components in endosseous implants depending on their shape and coating.

To investigate titanium surface abrasion of dental implants by mere insertion into the bone, we tested 20 implants of different shape, surface, and length. Under in vitro conditions, it could be proved that longer implants had more abrasion than cylindric implants, that screw implants had more abrasion than cylindric implants, that carved threads caused less abrasion than uncarved ones, and that plasma-flame-coated implants had more abrasion than implants with polished surfaces. Possible causes of the metal abrasion are discussed.

Animals↗
PubMed1994

[Xenogenic cartilage as a transplant for reconstruction of the facial skull].

90 patients were followed-up, in whom 110 cartilage grafts of bovine origin (Chondroplast) had been inserted. Nose and orbit (46 and/or 32 cartilage grafts) were the most frequent implantation sites. In three out of those 90 patients incorporation of the grafts was eventful. In two out of those three complication finally resulted in a loss of the graft. When following-up in 57 patients whether the grafts had kept their shape we found out that the cartilage grafts had still kept their shape quite well after three and a half years in 50 patients.

Animals↗
PubMed1992

Cloning and nucleotide sequence of the psrA gene of Wolinella succinogenes polysulphide reductase.

The polysulphide reductase (formerly sulphur reductase) of Wolinella succinogenes is a component of the phosphorylative electron transport system with polysulphide as the terminal acceptor. Using an antiserum raised against the major subunit (PsrA, 85 kDa) of the enzyme, the corresponding gene (psrA) was cloned from a lambda-gene bank. The N-terminal amino acid sequence of PsrA mapped within the psrA gene product, which also contained an apparent signal peptide. Downstream of the psrA gene two more open reading frames (psrB and psrC) were found. The three genes may form a transcriptional unit with the transcription start site in front of psrA. The three genes were present only once on the genome. PsrA is a hydrophilic protein homologous to the largest subunits of six prokaryotic molybdoenzymes. PsrB is predicted to be hydrophilic, to contain ferredoxin-like cysteine clusters and to be homologous to the smaller hydrophilic subunits of four molybdoenzymes. PsrC is predicted to be a hydrophobic protein that could possibly serve as the membrane anchor of the enzyme.

Amino Acid Sequence↗
PubMed1992

The quinone-reactive Ni/Fe-hydrogenase of Wolinella succinogenes.

The hydrogenase (Hyd) isolated from the cytoplasmic membrane of Wolinella succinogenes consists of three polypeptides (HydA, HydB and HydC) and contains cytochrome b (6.4 mumol/g protein), which was reduced upon the addition of H2. The enzyme catalyzed the reduction of 2,3-dimethyl-1,4-naphthoquinone with H2, in contrast to an earlier preparation which was made up of HydA and HydB only and did not contain cytochrome b (Unden, G., Böcher, R., Knecht, J. & Kröger, A. (1982) FEBS Lett. 145, 230-234). This suggests that HydC is a cytochrome b which serves as a mediator in the electron transfer from H2 to the quinone. The hydrogenase genes were cloned, sequenced and identified by sequence comparison with the N-termini of the three subunits. The three genes were arranged in the order hydA, hydB, hydC, with the transcription start site in front of hydA, and were present only once on the genome. Separated by an intergene region of 69 nucleotides, hydC was followed by at least two more open reading frames of unknown function. The amino acid sequences derived from hydA, hydB and hydC were similar to those of the membrane Ni-hydrogenases of seven other bacteria. HydA and HydB also showed similarity to the small and the large subunits of periplasmic Ni-hydrogenases. HydC was predicted to contain four hydrophobic segments which might span the bacterial membrane. Two histidine residues located in hydrophobic segments are conserved in the corresponding sequences of the other membrane hydrogenases and might ligate the haem B.

Amino Acid Sequence↗
PubMed1991

[Individually controlled sedation using Midazolam].

Midazolam might be an alternative to general anesthesia for noncooperative children. 40 children were treated during 94 midazolam sedations to evaluate the potential dental therapy. An average of 2 fillings and 1 endodontic treatment was possible per sedation. The initial Midazolam dosage was 0.6 mg/kg. Every 15 min another 0.3 mg Midazolam/kg were administered to maintain the treatability of the children. 30 min after the initial Midazolam dosage dental treatment could be started. The average duration of a sedation was 76 min. Our results suggest that sedations complement under dental treatment general anesthesia.

Anesthesia, Dental↗
PubMed1991

[Treatment of deciduous teeth under rectal Midazolam sedation].

Individual controlled sedation using Midazolam proves to be a valuable addition to the range of therapeutic options for non-cooperative children. In a clinical study the oral and rectal routes of administration were compared with each other. Rectal application allowed considerably better dose adjustment. While the quality of sedation and the therapeutic range were equal with both routes, rectal application had the advantage that treatment can be commenced sooner. The sedation was of shorter duration and left the patient with less unpleasant memories. Rectal application was easier and required a smaller amount of Midazolam than oral administration.

Administration, Oral↗