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J Rudolph

Publications and source records attributed to J Rudolph.

At least 37 records · Page 2Linked to original sources
PubMed2001

seco-Cyclothialidines: new concise synthesis, inhibitory activity toward bacterial and human DNA topoisomerases, and antibacterial properties.

seco-Cyclothialidines are a promising class of bacterial DNA gyrase B subunit inhibitors. A new seco-cyclothialidine derivative containing a dioxazine moiety, BAY 50-7952, was synthesized through a new concise pathway. One key step of the synthesis is the straightforward formation of the 2-aminothiazole derivative of S-tritylcysteine. In biological tests, BAY 50-7952 and other known seco-cyclothialidines exhibited high and selective activity toward bacterial DNA gyrase and toward Gram-positive bacteria. The dioxazine moiety and other similar groups were found to be important for the ability of the seco-cyclothialidines to penetrate bacterial membranes. The opposite enantiomer ((S)-form) of BAY 50-7952 was also synthesized, and neither significant target activity nor in vitro antibacterial activity were found, suggesting a highly selective fit of the (R)-form. Despite promising in vitro activity, only poor activity was found in the murine infection model.

Animals↗
PubMed2001

Specificity of natural and artificial substrates for human Cdc25A.

Cdc25A is a dual-specific protein phosphatase involved in the regulation of the kinase activity of Cdk-cyclin complexes in the eukaryotic cell cycle. To understand the mechanism of this important regulator, we have generated highly purified biochemical reagents to determine the kinetic constants for human Cdc25A with respect to a set of peptidic, artificial, and natural substrates. Cdc25A and its catalytic domain (dN25A) demonstrate very similar kinetics toward the artificial substrates p-nitrophenyl phosphate (k(cat)/K(m) = 15-25 M(-1) s(-1)) and 3-O-methylfluorescein phosphate (k(cat)/K(m) = 1.1-1.3 x 10(4) M(-1) s(-1)). Phospho-peptide substrates exhibit extremely low second-order rate constants and a flat specificity profile toward Cdc25A and dN25A (k(cat)/K(m) = 1 to 10 M(-1) s(-1)). In contrast to peptidic substrates, Cdc25A and dN25A are highly active phosphatases toward the natural substrate, T14- and Y15-bis-phosphorylated Cdk2/CycA complex (Cdk2-pTpY/CycA) with k(cat)/K(m) values of 1.0-1.1 x 10(6) M(-1) s(-1). In the context of the Cdk2-pTpY/CycA complex, phospho-threonine is preferred over phospho-tyrosine by more than 10-fold. The highly homologous catalytic domain of Cdc25c is essentially inactive toward Cdk2-pTpY/CycA. Taken together these data indicate that a significant degree of the specificity of Cdc25 toward its Cdk substrate resides within the catalytic domain itself and yet is in a region(s) that is outside the phosphate binding site of the enzyme.

Amino Acid Sequence↗
PubMed2001

Extracellular proteins of Staphylococcus aureus and the role of SarA and sigma B.

Staphylococcus aureus synthesizes a large number of extracellular proteins that have been postulated to play a role in bacterial virulence. The proteomic approach was used to analyse the pattern of extracellular proteins of two different S. aureus strains, RN6390 and COL. Thirty-nine protein spots were identified by N-terminal sequencing or MALDI-TOF-MS. The differences of the extracellular protein patterns between both strains are striking. Among the 18 proteins identified in S. aureus COL there are nine proteins not yet discovered in S. aureus RN6390. These are enterotoxin B, leukotoxin D, enterotoxin, serin proteases (SplA and SplC), thermonuclease, an IgG binding protein and two so far unknown proteins in S. aureus with similarities to SceD precursor in Staphylococcus carnosus and to synergohymenotropic toxin precursor in Streptococcus intermedius. In contrast, lipase as well as staphylokinase identified in S. aureus RN6390 were not detectable in S. aureus COL under the same conditions. By using a regulatory mutant of sarA (ALC136) isogenic to strain RN6390 we identified five proteins positively regulated by SarA and 12 proteins negatively regulated by SarA. Besides V8 protease (StsP) and Hlb already described to be regulated by the sar locus new putatively sarA-dependent proteins were identified, e.g. glycerolester hydrolase and autolysin both down-regulated in the sarA mutant, and aureolysin, staphylokinase, staphopain and format tetrahydrofolate lyase up-regulated in the mutant. Moreover, the role of sigma B in expression of extracellular proteins was studied. Interestingly, we found 11 proteins at an enhanced level in a sigB mutant of S. aureus COL, among them enterotoxin B, alpha and beta hemolysin, serine proteases SplA and SplB, leukotoxin D, and staphopain homologues. The sigma B-dependent repression of gene expression occurs at the transcriptional level. Only one protein, SceD, was identified whose synthesis was down-regulated in the mutant indicating that its gene belongs to the sigma B-dependent general stress regulon.

Amino Acid Sequence↗
PubMed2001

[Choledochus revision in the age of endoscopic papillotomy. Indications and outcome].

OBJECTIVE: In the age of endoscopic papillotomy (EPT) the operative revision of the bile duct needs to be used stringently and interventional therapeutic options have to be considered primarily in the treatment of gallbladder and bile duct stone disease. PATIENTS AND METHODS: 70 patients treated by choledochus revision for cholecysto- and choledocholithiasis in our department between 1988-1999 were analyzed retrospectively for indication and results. RESULTS: ERCPs were performed in only 24 patients. In 17 patients no endoscopic papillotomy could be accomplished due to a former operation (Billroth II or Whipple-OP). 70 patients underwent a surgical bile duct exploration with insertion of a T-drainage. The postoperative surgical complication rate amounted to 36%. The most frequent complications after revision of the common bile duct were edematous pancreatitis as well as bile duct fistula. 37 of 70 patients could be reexamined 4-48 months postoperatively. A pancreatitis or stenosis of papilla Vateri were not seen in these patients. In the sonography the common bile duct was inconspicuous. CONCLUSIONS: In the therapy of bile duct stones the therapeutic splitting has become generally accepted. The patients should be submitted to a ERCP with EPT and subsequent laparoscopic cholecystectomy. Surgical revision of the common bile duct nevertheless remains an important tool in the therapy of choledocholithiasis.

Adult↗
PubMed2001

[Experiences in stage-adapted therapy of pleural empyema].

INTRODUCTION: Up till now the phases adapted treatment of a pleural empyema unfortunately is still not obvious, but recently the operative spectrum has been widened in the field of video-assisted thoracoscopic surgery (VATS) of the pleural empyema. PATIENTS AND METHODS: In the present study we examined all our patients with a pleural empyema and we followed them for a postoperative period of 4 years analysing our therapy-efficacy and our treatment concept of pleural empyema. RESULTS: 52 out of 102 patients--who suffered from a pleural empyema in the last 10 years--were reexamined postoperatively. In 96% of the 102 cases we found a phase II-III empyema. Initially all patients were treated with a closed-chest-tube drainage, followed by an operation in 78%. In 6 cases a video-assisted-thoracoscopic evacuation of the cavity with an early decortication was performed. All the 52 patients who were treated in an early phase showed the best functional results 4 years later. CONCLUSION: Especially in phase III the open operative revision of a pleural empyema is the method of choice. In the fibrinopurulent phase the drainage therapy may be sufficient. If the empyema cavity is divided we recommend the early video-assisted-thoracoscopic revision of the thoracic empyema.

Adolescent↗
PubMed2001

[A case of painful defect of unknown origin of the pediatric patella].

An uncertain history of potential trauma versus possible developmental variants and disorders in childhood may cause differential diagnostic problems in pediatric radiology. We report the case of a 12-year old boy with an unclear unilateral defect of the patella and long-persisting complaints in his knee. The plain radiological and MRI morphology of this lesion are described and possible differential diagnoses are discussed.

Arthralgia↗
PubMed2000

Dual-specific Cdc25B phosphatase: in search of the catalytic acid.

Cdc25 is a dual-specificity phosphatase that catalyzes the activation of the cyclin-dependent kinases, thus causing initiation and progression of successive phases of the cell cycle. Although it is not significantly structurally homologous to other well-characterized members, Cdc25 belongs to the class of well-studied cysteine phosphatases as it contains their active site signature motif. However, the catalytic acid needed for protonation of the leaving group has yet to be identified. To elucidate the role and identity of this key catalytic residue, we have performed a detailed pH-dependent kinetic analysis of Cdc25B. The pK(a) of the catalytic cysteine was found to be 5.6-6.3 in steady state and one-turnover burst experiments using the small molecule substrates p-nitrophenyl phosphate and 3-O-methylfluorescein phosphate. Interestingly, Cdc25B does not exhibit the typical bell-shaped pH-rate profile with small molecule substrates seen in other cysteine phosphatases and indicative of the catalytic acid because it lacks pH dependence between 6.5 and 9. Reactions of Cdc25B with the natural substrate Cdk2-pTpY/CycA, however, did yield a bell-shaped pH-rate profile with a pK(a) of 6.1 for the catalytic acid residue. Recent structural studies of Cdc25 have suggested that Glu474 [Fauman, E. B., et al. (1998) Cell 93, 617-625] or Glu478 [Reynolds, R. A., et al. (1999) J. Mol. Biol. 293, 559-568] could function as the catalytic acid in Cdc25B. Using site-directed mutagenesis and truncation experiments, however, we found that neither of these residues, nor the unstructured C-terminus, is responsible for the observed pH dependence. These results indicate that the catalytic acid does not appear to lie within the known structure of Cdc25B and may lie on its protein substrate.

Amino Acid Substitution↗
PubMed2000

[Indirect MR arthrography in the diagnosis of rotator cuff lesions].

PURPOSE: To determine the value of indirect MR arthrography in lesions of the rotator cuff, prospectively versus arthroscopy. METHODS: 63 patients with suspected shoulder pathology were examined: oblique-coronary and axial T1w sequences, axial FLASH-2D sequences, furthermore oblique-coronary T2- and PD-weighted sequences were taken. After intravenous administration of 0.1 mmol Gd-DTPA/kilogram body weight and active motion of the shoulder T1w sequences were repeated. Signal intensities (SI) inside the tendon were quantitatively measured by the ROI technique (region-of-interest) and the percentual contrast-enhancement CE was calculated. In 32 patients the results were confirmed by surgical follow-up. RESULTS: The mean SI measured in the supraspinous tendon were higher in lesions (degeneration, impingement, partial and total rupture), before as well as after contrast medium, compared to intact findings (p < 0.05). Similarly the percentual CE (p < 0.05) was higher. We detected 9 total ruptures and three impingements (for both sensitivity before/after Gd-DTPA 100%), furthermore 6 partial ruptures. Of the latter three were false positive and one false negative, leading to a sensitivity of 75% and a specificity of 50%. CONCLUSION: The visualization of rotator cuff lesions can be optimized with indirect MR arthrography. The detection of partial ruptures remains faulty, because the exact demarcation of degenerative change and partial rupture is still difficult.

Adolescent↗
PubMed1999

Car: a cytoplasmic sensor responsible for arginine chemotaxis in the archaeon Halobacterium salinarum.

A new metabolic signaling pathway for arginine, both a chemoeffector and a fermentative energy source, is described for Halobacterium salinarum. Systematic screening of 80+ potentially chemotactic compounds with two behavioral assays identified leucine, isoleucine, valine, methionine, cysteine, arginine and several peptides as strong chemoattractants. Deletion analysis of a number of potential halobacterial transducer genes led to the identification of Car, a specific cytoplasmic arginine transducer which lacks transmembrane helices and was biochemically shown to be localized in the cytoplasm. Flow assays were used to show specific adaptive responses to arginine and ornithine in wild-type but not Deltacar cells, demonstrating the role of Car in sensing arginine. The signaling pathway from external arginine to the flagellar motor of the cell involves an arginine:ornithine antiporter which was quantitatively characterized for its transport kinetics and inhibitors. By compiling the chemotactic behavior, the adaptive responses and the characteristics of the arginine:ornithine antiporter to arginine and its analogs, we now understand how the combination of arginine uptake and its metabolic conversion is required to build an effective sensing system. In both bacteria and the archaea this is the first chemoeffector molecule of a soluble methylatable transducer to be identified.

Amino Acids↗
PubMed1999

[A prospective study on the detection of lesions of the labrum glenoidale by indirect MR arthrography of the shoulder].

PURPOSE: Aim of this prospective study was the evaluation of signal-alterations of anatomic shoulder structures before and after intravenous application of Gd-DTPA. Furthermore the tested clinical value of indirect MR-arthrography in detecting labrum lesions was tested. MATERIAL AND METHODS: 52 patients with suspected shoulder injury were examined on a 1.5 T system: Sequences were T1-weighted axial and oblique-coronary, additionally oblique-coronary T2-weighted, PD-weighted- and axial FLASH-2D-Sequences. After intravenous injection of contrast medium T1-weighted sequences were repeated. Signal-intensities (SI) of anatomic structures were measured by ROI-technique, the percentual contrast-enhancement (CE) and alterations in SNR (signal-noise-ratio) and CNR (contrast-noise-ratio) were calculated. Labrum tears were graded by three observers, their results could be confirmed by arthroscopy or open surgery in 24 patients. RESULTS: Contrast-enhancement was shown in all structures, most remarkable in the joint cavity. In pathologic findings of the labrum the SI and CE were significantly higher compared to intact strictures (p < 0.05). Sensitivity and specificity in the detection of labrum tears were 70% and 71.4% without contrast media, respectively 100% and 71.4% with indirect arthrography. CONCLUSIONS: The indirect arthrography improves the signal parameters of the structures. The detection of labrum lesions is improved, but still remains difficult.

Adolescent↗
PubMed1998

[Duplication of the stomach as a rare cause of cystic epigastric tumor].

Duplications of the gastrointestinal tract are congenital anomalies seen in about 0.2% of all children. These include the rare gastric duplications. Latter diagnosis is usually made in the first months after birth on recurrent vomiting by detection of an abdominal tumor. The most important imaging modality is ultrasonography. The case of a prematurely born child weighing 1900 g is presented in whom at the age of three weeks a gastric duplication of the greater curvature was diagnosed and who was successfully treated by resection. The postoperative follow-up for 24 months was uncomplicated.

Cysts↗
PubMed1996

A family of halobacterial transducer proteins.

A DNA probe to the signaling domain of a halobacterial transducer for phototaxis (HtrI) was used to clone and sequence four members of a new family of transducer proteins (Htps) in Halobacterium salinarium potentially involved in chemo- or phototactic signal transduction. The signaling domains in these proteins have 31-43% identity when compared with each other or with their bacterial analogs, the methyl-accepting chemotaxis proteins. An additional region of homology found in three of the Htps has 31-43% identity with HtrI. The Htps contain from 0 to 3 transmembrane helices and Western blotting showed that HtpIII is soluble. The arrangement of the domains in these Htps suggests a modular architecture in their construction.

Amino Acid Sequence↗
PubMed1996

Deletion analysis of the che operon in the archaeon Halobacterium salinarium.

Halobacterium salinarium is a chemo- and phototactic archaeon whose signal transduction pathway includes the classical two-component system made up of CheA and CheY. Deletion analysis of the che operon in H. salinarium has been undertaken. Following the removal of the entire operon, the importance of each of the four individual members, cheY, cheB, cheA, and the novel member cheJ, was evaluated by their replacement in combinations of three. The mutant strains were investigated for their motility, their chemo- and phototactic signalling, and the rotational bias of their flagella. Loss of cheA, cheY or cheB led to the complete loss of chemo- and phototaxis, whereas the absence of cheJ caused a reduction in chemo- and phototactic ability. Reverse swimming and counterclockwise rotation of the flagella required the presence of cheA and CheY. The wild-type 50:50 distribution of forward and reverse swimming was observed in the strain lacking cheB, whereas this distribution was perturbed to 88:12 in the strain lacking cheJ. These results are compared with the corresponding deletion strains in Escherichia coli and provide new insights into the eu- and archeabacterial flagellar switch.

Bacterial Proteins↗
PubMed1996

Ovarian remnant syndrome: experience at Jackson Memorial Hospital, University of Miami, 1985 through 1993.

OBJECTIVE: Ovarian remnant syndrome has become increasingly recognized as a cause of pelvic pain after extirpative surgery. The purpose of this review was to compare our patient population with those reported in the literature, as well as to address the usefulness of careful retroperitoneal discussion in the surgical management of these patients. STUDY DESIGN: This article discusses the presentation and surgical management of eight cases of ovarian remnant. RESULTS: Data were obtained through a retrospective chart review of pathologically confirmed cases of ovarian remnant. Discussion focuses on the surgical management of these cases. CONCLUSION: In summary, extensive and careful retroperitoneal dissection is typically required to facilitate identification and removal of the ovarian remnant tissue.

Adult↗