PubMed Health⌕ Search

Biomedical subjects

J Rudolph

Publications and source records attributed to J Rudolph.

At least 19 recordsLinked to original sources
PubMed2007

[Pulmonary embolism and deep vein thrombosis in the inferior vena cava affected by a rare anomaly].

Persistent left-sided inferior vena cava (VCI) is a rare venous anomaly, its prevalence being estimated at 0.2-0.5%. Thrombotic occlusion of a VCI has been reported in only a few of these cases. We report the case of a 24-year old woman who suffered an acute thrombosis in a left-sided VCI and recurrent pulmonary embolism. After thrombectomy the course was uneventful. The diagnostic approach and the treatment strategy are discussed with reference to the literature.

Adult↗
PubMed2006

[A new method for standardized diagnosis following renal transplantation. Ultrasound with contrast enhancement].

Ultrasound (US) imaging is an important diagnostic tool following renal transplantation. Unfortunately, due to the heterogeneity of the recipients and their multimorbidity, imaging procedures in the early phase after kidney transplantation are difficult and of limited use. We performed a study to evaluate the use of a contrast enhancer for US examination as a standardized method in the follow-up of kidney transplant recipients.The study included 40 recipients: 32 were examined on the 5th to 7th day following transplantation and 8 patients at the time when clinically suspicious findings occurred (acute rejection, tumor, acute tubular necrosis). Following the intravenous application of the contrast medium, pictures were taken during the arterial and parenchymatous phase and compared with conventional B-mode and power Doppler pictures of the same visual plane. Three examiners assessed different parameters of the transplant organ (max. vascularized area, suspected hematomas, tumors, rejection, acute tubular necrosis). Findings were confirmed by histological results of a biopsy if rejection, tumor, or acute tubular necrosis were suspected. Application of ultrasound contrast medium significantly increased visualization of the vascularized kidney area. Also, US findings in the follow-up after acute rejection therapy corresponded with the clinical course; 19 hematomas could be detected with contrast medium compared to only 9 without. With contrast medium a perfusion deficit was detectable in three patients compared to one patient with power Doppler US. Also, US contrast medium helped to detect tumor vascularization in two patients in whom conventional sonography suspected no abnormality. Ultrasound contrast medium enhancement is a reproducible, reliable, and easy to apply method which is superior to conventional sonography in the follow-up after kidney transplantation. This method is also helpful to detect and control acute rejections and to better visualize hematomas, deficits of perfusion, and tumors.

Adolescent↗
PubMed2006

[Lipoma of the cerebellopontine angle - a case report].

BACKGROUND: Lipomas of the cerebellopontine angle are rare. Until today in the english literature only isolated cases are described. The most frequent symptoms are: hearing loss (62,2 %), vertigo (43,3 %) and tinnitus (42,2 %). With the help of MRI intracranial lipomas can be diagnosed almost certainly. PATIENT: A 26 year old patient presented himself to our outpatient departement with recurrent vertigo and tinnitus since two months. Electronystagmography and caloric testing showed a unilateral weakness of the right vestibular organ. Audiometric examination revealed a Normacusis on the right side. BERA resulted in borderline prolonged interpeaklatency on the right side, wave I-V. MRI showed a ca. 5x8x11 mm Lipoma of the right cerebellopontine angel which surrounded the vestibulocochlear nerve. In contrast to schwannomas which are often described in this area the lesion did not enhance contrast medium. On the native T1 sequence the tumor was hyperintense and fat-supression images confirmed the tumor to be fat in origin. Because of the minor symptoms and the small size of the tumor we recommended a BERA after six months and an MRI every year. CONCLUSION: The therapeutic options of a lipoma of the cerebellopontine angel depend on the clinical symptoms and a radiologic confirmed progression of size. Because of the received data until today an operative therapy is only indicated when symptoms clinically can not be treated or the leason seems to be a well differentiated liposarcoma.

Adult↗
PubMed2005

[Transarterial embolization for uterine fibroids: clinical success rate and results of magnetic resonance imaging].

PURPOSE: To analyze the clinical success rate and the findings of magnetic resonance imaging (MRI) after uterine artery embolization of symptomatic leiomyomas (fibroids) of the uterus. MATERIALS AND METHODS: This is a prospective single-center case study of 80 consecutively treated patients, followed for 3 - 6 months (group I), 7 - 12 months, (group II), and 13 - 25 months (group III). MRI was used to determine the uterine volume and size of the dominant leiomyoma. Symptoms and causes requiring repeat interventions were analyzed. RESULTS: Significant (p < 0.01) volume reduction of the uterus (median: 34.95 % confidence interval [CI]: 30.41 - 41.76 %) and dominant leiomyoma (median: 52.07 %, CI: 47.71 - 61.57 %) was found. The decrease in uterine volume (I-III: 22.68 %, 33.56 %, 47.93 %) and dominant leiomyoma volume (I-III: 41.86 %, 62.16 %, 73.96 %) progressed with the follow-up time. Bleeding resolved significantly (p < 0.0001) in all three follow-up groups (groups I-III: 92.86 %, 95.23 %, 96.67 %). Furthermore, urinary frequency (groups I-III: 70 %, 75 %, 82.35 %) and sensation of pelvic pressure (groups I-III: 42.86 %, 60 %, 93.75 %) improved, which was statistically significant in group III (p < 0.01). The number of leiomyomas correlated (p < 0.05) with improvement of the bleeding and the pelvic pressure. Repeat therapy was necessary for complications in four patients (5 %) and for therapeutic failure in three patients (3.8 %). Permanent amenorrhea was observed in four patients (5 %) of age 45 years or older. CONCLUSION: Uterine artery embolization of uterine leiomyomas has a high clinical success rate with an acceptable incidence of complications and repeat interventions.

Adult↗
PubMed2005

Coarse and reliable geometric alignment for protein docking.

We present an efficient algorithm for generating a small set of coarse alignments between interacting proteins using meaningful features on their surfaces. The proteins are treated as rigid bodies, but the results are more generally useful as the produced configurations can serve as input to local improvement algorithms that allow for protein flexibility. We apply our algorithm to a diverse set of protein complexes from the Protein Data Bank, demonstrating the effectivity of our algorithm, both for bound and for unbound protein docking problems.

Algorithms↗
PubMed2004

Remote hot spots mediate protein substrate recognition for the Cdc25 phosphatase.

Cdc25B is a phosphatase that catalyzes the dephosphorylation and activation of the cyclin-dependent kinases, thus driving cell cycle progression. We have identified two residues, R488 and Y497, located >20 A from the active site, that mediate protein substrate recognition without affecting activity toward small-molecule substrates. Injection of Cdc25B wild-type but not the R488L or Y497A variants induces germinal vesicle breakdown and cyclin-dependent kinase activation in Xenopus oocytes. The conditional knockout of the cdc25 homolog (mih1) in Saccharomyces cerevisiae can be complemented by the wild type but not by the hot spot variants, indicating that protein substrate recognition by the Cdc25 phosphatases is an essential and evolutionarily conserved feature.

Animals↗
PubMed2004

Anomalous spin dephasing in (110) GaAs quantum wells: anisotropy and intersubband effects.

A strong anisotropy of electron spin decoherence is observed in GaAs/(AlGa)As quantum wells grown on a (110) oriented substrate. The spin lifetime of spins perpendicular to the growth direction is about one order of magnitude shorter compared to spins along [110]. The spin lifetimes of both spin orientations decrease monotonically above temperatures of 80 and 120 K, respectively. The decrease is very surprising for spins along the [110] direction and cannot be explained by the usual Dyakonov-Perel dephasing mechanism. A novel spin dephasing mechanism is put forward that is based on scattering of electrons between different quantum well subbands.

Journal Article↗
PubMed2004

Cdc25 phosphatases and cancer.

The Cdc25 phosphatases function as key regulators of the cell cycle during normal eukaryotic cell division and as mediators of the checkpoint response in cells with DNA damage. The role of Cdc25s in cancer has become increasingly evident in recent years. More than 20 studies of patient samples from diverse cancers show significant overexpression of Cdc25 with frequent correlation to clinical outcome. Recent screening and design efforts have yielded novel classes of inhibitors that show specificity for the Cdc25s over other phosphatases and cause cell cycle arrest in vivo. Herein we provide a single source for those interested in the cellular functions of Cdc25 in cell cycle progression, its role in the progress of cancer and survival of cancer patients, and recent efforts in the design of specific inhibitors.

Animals↗
PubMed2004

Early postoperative ultrasound of kidney transplants: evaluation of contrast medium dynamics using time-intensity curves.

OBJECTIVE: To evaluate kidney recipients in the early posttransplant phase by semiquantitative analysis of the arterial arrival of ultrasound (US) contrast medium using time-intensity curves. PATIENTS AND METHODS: Twenty-two kidney recipients underwent US examination after intravenous bolus administration of 2.4 ml of US contrast medium (SonoVue, Bracco Altana) 5 to 7 days after transplantation. The examinations were performed with the Aplio US system (Toshiba) and a 3.5-MHz wideband transducer using contrast harmonic imaging at a low mechanical index of 0.1. Arterial arrival was documented digitally over 60 sec (image repetition rate: 10 images per sec) for subsequent evaluation of contrast medium kinetics in the main renal artery, interlobar artery, subcapsular area, and renal vein using the system's integrated time-intensity curve (TIC) software. The increase, decrease, and percentage enhancement factor were calculated from the curves. Four patients were excluded from analysis because of perirenal hematoma (n = 3) or a polar perfusion loss demonstrated by power Doppler (n = 1). RESULTS: Twelve of the remaining 18 patients assigned to the nonrejection group showed an uneventful clinical course. These had uniform TICs with an early and steep increase of similar magnitude in the main renal artery (11.7 +/- 4.5 intensity units/sec), interlobar artery (8.7 +/- 4.6 intensity units/sec), and subcapsular area (8.3 +/- 3.7 intensity units/sec) followed by a washout and subsequent plateau phase. Six patients showed histologically proven acute rejection on day 5 or 6 after transplantation (rejection group). This group had a delayed (time to peak in the subcapsular area: 32.9 +/- 8.3 sec in the rejection group versus 20.9 +/- 4.7 sec in the nonrejection group, p < 0.05) and smaller subcapsular percentage increase (41.2 +/- 21.9 % versus 114.4 +/- 59.8 %, p < 0.05). In the rejection group the subcapsular area (3.8 +/- 2.3 intensity units/sec) showed a less pronounced increase than the main renal artery (7.9 +/- 5.9 intensity units/sec) and interlobar artery (8.7 +/- 3.8 intensity units/sec). The RI in the rejection group was in the normal range at the time of contrast-enhanced US (day 5: 0.78 +/- 0.06) and increased to abnormal levels in the further course (day 7: 0.94 +/- 0.09). CONCLUSIONS: Quantitative determination of arterial arrival of an US contrast medium in the early phase after kidney transplantation is possible. This new US procedure might identify acute rejection earlier than conventional techniques.

Adult↗
PubMed2004

Unusual enhancement pattern of liver lesions in hepatosplenic candidiasis.

PURPOSE: To describe an unusual enhancement pattern of hepatosplenic candidiasis (HSC) liver lesions in biphasic spiral liver computed tomography (CT). MATERIAL AND METHODS: Twenty-one patients with suspected HSC were scanned with a biphasic liver CT perfusion protocol. The liver lesions detected were assessed for their morphology and enhancement pattern during both perfusion phases. A liver biopsy was performed in 11/21 patients. RESULTS: The majority of hepatic lesions in 15/21 patients showed the well-known abscess-like pattern. In 6/21 patients an uncommon central contrast enhancement with a peripheral double ring was detected in the arterial phase. In some cases the lesions showed decreased diameter or even seemed to disappear completely in the portalvenous phase. CONCLUSIONS: CT in the arterial phase showed an unusual enhancement pattern of liver lesions in HSC. Scanning only in the portalvenous phase implies possible pitfalls, because lesions may be overlooked or undersized. Therefore, biphasic liver CT is considered essential in the diagnosis and follow-up of HSC in clinical practice.

Adult↗
PubMed2002

Cloning of the genomes of equine herpesvirus type 1 (EHV-1) strains KyA and racL11 as bacterial artificial chromosomes (BAC).

The genome of equine herpesvirus type 1 (EHV-1) strain RacL11, a highly virulent isolate obtained from an aborted foal, and that of the modified live vaccine strain KyA, were cloned as bacterial artificial chromosomes (BAC) in Eseherichia coli. Mini F plasmid sequences were inserted into the viral genomes by homologous recombination instead of the gene 71 (EUS4) open reading frame after co-transfection of viral DNA and recombinant plasmid pdelta71-pHA2 into RK13 cells. After isolation of recombinant viruses by three rounds of plaque purification, viral DNA was isolated from RK13 cells infected with RacL11 or KyA virus mutants expressing the green fluorescent protein (GFP), and electroporated into Escherichia coli DH10B cells. Several bacterial colonies were shown to contain high-molecular weight BAC DNA with a restriction enzyme fragment pattern indicative of the presence of full-length RacL11 or KyA genomes. Two selected BAC clones were analysed by restriction enzyme analysis and Southern blotting, and were eventually termed pRacLI I and pKyA. respectively. Upon transfection of pRacL11 or pKyA DNA into RK13 cells, GFP-expressing fluorescing virus plaques could be identified from day 1 after transfection. Infectivity after transfection of pRacL11 or pKyA could be readily propagated on RK13 or equine cells, indicating that infectious full-length DNA clones of strains RacL11 and KyA were successfully cloned in Escherichia coli as BACs. The glycoprotein 2-negative progeny reconstituted from pRacL11 and pKyA (L11deltagp2 and KyAdeltagp2) exhibited different growth properties. Whereas both L11deltagp2 and KyAdeltagp2 extracellular titres were reduced by 15- to 32-fold, plaque diameters were only markedly (50%) reduced in the case of KyAdeltagp2.

Animals↗
PubMed2002

[Visceral artery aneurysms].

The purpose of this article is to review the etiology, clinical presentation and treatment options of visceral artery aneurysms (VAA) on the basis of our experiences. Visceral artery aneurysms are uncommon lesions with a frequency of 0,1-0,2 % in autopsy statistics. In fact many visceral artery aneurysms still present first with a rupture (22 %) and despite emergency laparotomies the mortality rate is about 8,5 %. The course of disease often is disastrous due to rupture of the aneurysms or thromboembolic complications, emphasizing the importance to be aware of this differential diagnosis of abdominal pain. This article covers 9 patients with VAA. 3 patients each revealed an a. lienalis aneurysm and a. gastrica aneurysm, resp. In the other 3 patients an aneurysm of the a. gastroepiploica, the a. pancreatico-duodenalis and the a. mesenterica superior resp. was proven. In 8 of 9 patients a surgical therapy of the VAA took place. Only 2 patients (22 %) were interventionally treated. 1 patient deceased due to postoperative hemorrhage. Both the surgical and the radiological intervention therapy are available for treatment of the VAA. The decision on the choice of the therapeutic procedure should be made on an individual basis.

Abdomen, Acute↗
PubMed2001

The C-terminal tail of the dual-specificity Cdc25B phosphatase mediates modular substrate recognition.

Cdc25 is a dual-specificity phosphatase that catalyzes the activation of the cyclin-dependent kinases (Cdk/cyclins), thus triggering initiation and progression of successive phases of the cell cycle. In our efforts to elucidate the interaction between Cdc25B and the natural substrate, bis-phosphorylated Cdk2/CycA (Cdk2-pTpY/CycA), we have previously found that the 17 residues of the C-terminal tail mediate a factor of 10 in substrate recognition. In the studies reported here, we localize the majority of this interaction using site-directed mutagenesis to two arginine residues (Arg556 and Arg562) located within this C-terminal region. We also show that the catalytic domain of Cdc25C, which differs most significantly from Cdc25B in this tail region, has a 100-fold lower activity toward Cdk2-pTpY/CycA. We further demonstrate that the proper presentation of the C-terminal tail of Cdc25B can be achieved in a "gain-of-function" chimeric protein consisting of the C-terminal tail of Cdc25B fused onto the catalytic core of Cdc25C. The >10-fold increase in activity seen only in the chimeric protein containing the two critical arginine residues demonstrates that the modular C-terminal tail of Cdc25B is the basis for most of the catalytic advantage of Cdc25B versus Cdc25C toward the Cdk2-pTpY/CycA substrate.

Amino Acid Sequence↗
PubMed2001

Highly efficient chiral-pool synthesis of (2S,4R)-4-hydroxyornithine.

[reaction: see text] A concise synthesis of the amino acid (2S,4R)-4-hydroxyornithine is described. Starting from diprotected L-aspartic acid, the scaffold of the target compound is constructed in a three-step approach: an efficient alpha-nitroketone formation through acylation of nitromethane is followed by a diastereoselective reduction of the resulting ketone. In the last step, the nitro group is reduced to furnish the (2S,4R)-4-hydroxyornithine scaffold. This new approach to the title compound offers advantages to the synthetic pathways previously described.

Aspartic Acid↗