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Biomedical subjects

G Kramer

Publications and source records attributed to G Kramer.

At least 55 records · Page 3Linked to original sources
PubMed2000

Sequential administration of interferon gamma and interleukin-2 in metastatic renal cell carcinoma: results of a phase II trial. Austrian Renal Cell Carcinoma Study Group.

BACKGROUND: Because of the known efficacy of several cytokines in the treatment of advanced renal cell cancer (RCC), we have conducted a phase II trial of the efficacy and toxicity of subcutaneous interferon gamma (IFNgamma) and interleukin-2 (IL-2). METHODS: 63 patients with progressive metastatic RCC were treated with 100 microg recombinant IFNgamma1b administered three times weekly during weeks 1 and 2 and with 4.5 MU recombinant IL-2 administered on 4 consecutive days during weeks 3 and 4, every 6 weeks. RESULTS: 11% of patients had an objective response (CR: 3%, PR: 8%), 33% had SD. Toxicity was generally mild. The median duration of remissions (CR + PR) was 9.6 months; the median duration of SD 8 months. A significant survival benefit was evident at a median observation time of 51 months for patients (44%) responding to therapy (P < 0.0001). CONCLUSIONS: we conclude that sequential treatment with IFNgamma and IL-2 may prolong survival in patients with metastatic RCC responding to therapy.

Adult↗
PubMed2000

Long term survival of a patient with malignant pleural mesothelioma as a late complication of radiotherapy for Hodgkin's disease treated with 90yttrium-silicate.

A case of malignant pleural mesothelioma (PM) 24 years after thoracic radiotherapy for Hodgkin's disease is presented. As primary treatment and to relieve symptoms of dyspnea secondary to pleural effusion a thoracic drain was installed, followed by intracavitary radiation therapy with 90yttrium-silicate. Minor complaints of fever and a dry cough as a side-effect of this treatment were effectively treated with prednisone during 2 weeks. The patient remains in a good clinical condition now 6 years after diagnosis. Considering the few therapeutic options the use of 90yttrium-silicate intrapleural installation could be propagated as a safe and effective antitumour treatment for a selected group of patients with malignant PM.

Hodgkin Disease↗
PubMed2000

Initiation of protein synthesis with fluorophore-Met-tRNA(f) and the involvement of IF-2.

The complicity of initiation factor 2 (IF-2) in causing the observed low incorporation of N-terminal fluorophore from fluorophore-methionyl-tRNA(f) during protein synthesis in an in vitro coupled transcription/translation system was investigated. The low incorporation in comparison to formyl-methionine was not due to the lack of interaction of fluorophore-Met-tRNA(f) with IF-2. Fluorescence measurements of cascade yellow-, eosin-, pyrene-, or coumarin-Met-tRNA(f) determined that all were capable of binding IF-2 at 4 mM Mg(2+) and 37 degrees C. Filter binding assays conducted in the absence of magnesium ions on fMet-tRNA(f), eosin-Met-tRNA(f), and cascade yellow-Met-tRNA(f) confirmed the previously reported value for the dissociation constant of fMet-tRNA(f) of about 1 microM and placed the binding constants for the two fluorophore derivatives about three-fold higher. Binding of the fluorophore-Met-tRNA(f) species to salt-washed ribosomes showed a more significant decrease compared to fMet-tRNA(f). Stimulation in the amount of tRNA bound to the ribosomes upon the addition of IF-2 was observed in each case. All ribosome-bound cascade yellow-Met-tRNA(f) and eosin-Met-tRNA(f) were as puromycin-reactive as fMet-tRNA(f). Cumulatively, the effects observed for the fluorophore-Met-tRNA species in partial reactions of initiation may account for the reduced incorporation of these probes at the N terminus of polypeptides.

Codon, Initiator↗
PubMed2000

Feasibility study prior to the certification of trace elements in urban and industrial wastewater reference materials.

Reliable results for the determination of trace elements in urban and industrial wastewaters are of paramount importance for both checking the performance of sewage treatment and for detecting possible urban or industrial contamination sources. The quality control of measurements should in principle rely on external tools such as certified reference materials (CRM), which should represent, as closely as possible, the matrix of samples currently analysed, e.g., in the frame of environmental monitoring. To date, however, no CRM representatives of wastewater composition are available, which limits the possibility for control laboratories to check their QC externally. To fill this gap, the European Commission's Standards, Measurements and Testing Programme (formerly BCR) has started a European collaborative project of which the aim is to test the feasibility of preparation of wastewater reference materials and the analytical state-of-the-art to enable the certification of trace elements in such matrices. This paper presents the results of the first phase of this project, namely the feasibility study and the results of an interlaboratory trial.

Certification↗
PubMed2000

The impact of health status on waiting time for major joint arthroplasty.

This study was conducted to determine the impact of health status on waiting time for major joint arthroplasty in a universal publicly funded health system. Data were collected prospectively from a cohort of 553 patients waiting for total hip or total knee arthroplasty. The WOMAC and SF-36 health status instruments were administered at the time the patient was placed on the waiting list. The outcome measure was length of waiting time. Multivariate analyses found increased body mass index and decreased social function as the only determinants of waiting time. This model explained only 4% of the variance in waiting time. The association between health status and waiting time for arthroplasties appears to be small. These findings suggest that major joint arthroplasty is not prioritized on the basis of burden of illness.

Adult↗
PubMed2000

Vinorelbine and interferon-alpha2c as second-line therapy in metastatic renal cell carcinoma.

Second-line treatment of patients with metastatic renal cell carcinoma (MRCC) progressing under therapy with biological response modifiers (BRM) is an unresolved issue. Thirty-seven patients with MRCC progressing under treatment with BRM received vinorelbine i.v. at a dose of 30 mg/m2 q 22 days and 4,800,000 IU interferon (IFN)-alpha2c s.c. thrice weekly. Partial remission (PR) occurred in 8% of patients, stable disease (SD) (median duration 8, range 3-35+ months) was observed in 46% of patients. Median overall survival was 15 (range 1-49) months. No major toxicities occurred. Patients with MRCC who failed first-line treatment with BRM had a high chance to enter PR or SD under combined, low-toxic therapy with vinorelbine and IFN-alpha2c.

Adult↗
PubMed2000

Botulinum-A toxin for treating detrusor hyperreflexia in spinal cord injured patients: a new alternative to anticholinergic drugs? Preliminary results.

PURPOSE: We evaluated the efficacy of botulinum-A toxin injections into the detrusor muscle in patients with spinal cord injury, detrusor hyperreflexia and urge incontinence resistant to anticholinergic drugs. The purpose of treatment was to suppress incontinence episodes and increase functional bladder capacity. MATERIALS AND METHODS: Included in our prospective nonrandomized study done at 2 clinics were 31 patients with traumatic spinal cord injury who emptied the bladder by intermittent self-catheterization. These patients had severe detrusor hyperreflexia and incontinence despite a high dose of anticholinergic medication. Pretreatment evaluation included a clinical examination and complete urodynamic investigation. Under cystoscopic control a total of 200 to 300 units of botulinum-A toxin were injected into the detrusor muscle at 20 to 30 sites (10 units per ml. per site), sparing the trigone. Clinical and urodynamic followup was planned for 6, 16 and 36 weeks after treatment. Patients were asked to decrease their intake of anticholinergic drugs during week 1 after treatment. RESULTS: Of the 21 patients 19 underwent a complete examination 6 weeks after the botulinum-A toxin injections, and 11 at 16 and 36 weeks. At the 6-week followup complete continence was restored in 17 of 19 cases in which anticholinergic medication was markedly decreased or withdrawn. Less satisfactory results in 2 cases were associated with an insufficient dose of 200 units botulinum-A toxin. After the injections overall mean reflex volume and mean maximum cystometric bladder capacity plus or minus standard deviation significantly increased from 215.8 +/- 90.4 ml. to 415.7 +/- 211.1 (p <0.016) and 296.3 +/- 145.2 to 480.5 +/- 134.1 (p <0.016), respectively. There was also a significant decrease after treatment in mean maximum detrusor voiding pressure from 65.6 +/- 29.2 cm. water to 35 +/- 32. 1 (p <0.016). Mean post-void residual urine volume catheterized at the end of the urodynamic examination increased significantly from a mean of 261.8 +/- 241.3 ml. to 490.5 +/- 204.8 (p <0.016). Moreover, autonomic dysreflexia associated with bladder emptying that manifested as a hypertensive crisis during voiding disappeared after treatment in the 3 patients with tetraplegia. Satisfaction was high in all successfully treated patients and no side effects were observed. Ongoing improvement in urodynamic parameters and incontinence was already present in all patients reevaluated at 16 and 36 weeks. CONCLUSIONS: Botulinum-A toxin injections into the detrusor seem to be a safe and valuable therapeutic option in spinal cord injured patients with incontinence resistant to anticholinergic medication who perform clean intermittent self-catheterization. Successfully treated patients become continent again and may withdraw from or markedly decrease anticholinergic drug intake. A dose of 300 units botulinum-A toxin seems to be needed to counteract an overactive detrusor. The duration of bladder paresis induced by the toxin is at least 9 months, when repeat injections are required.

Adolescent↗
PubMed2000

Role of bacteria in the development of kidney stones.

Currently, only struvite stones are regarded as deriving from bacteria. Recent work has suggested that calcium-based stones might also have an infectious origin. Nanobacteria, small intracellular bacteria found in human kidney stones, are capable of forming a calcium phosphate shell, and thus could serve as crystallization centres for renal calculi formation. Until now, however, all trials performed to confirm the presence of nanobacteria in human calculi, serum or urine have failed. In a hyperoxaluric rat model, tissue-residing macrophages were able to remove interstitial crystals and thus may not be primarily engaged in defending against micro-organisms, if present.

Animals↗
PubMed2000

Is one set of sextant biopsies enough to rule out prostate Cancer? Influence of transition and total prostate volumes on prostate cancer yield.

PURPOSE: Although the sextant biopsy technique has been widely used, concern has arisen that this method may not include an adequate sampling of the prostate, especially for large prostate volumes. We conducted a multicenter study in patients with PSA levels <10 ng/ml to determine the influence of the total and transition zone (TZ) volumes of the prostate for predicting whether one single set of biopsies was sufficient to rule out prostate cancer (PCa). These parameters were evaluated in patients in whom PCa was found after one set of systematic sextant biopsies and those in whom PCa was found after a repeat biopsy. MATERIALS AND METHODS: A total of 1,018 patients were included in this study. All underwent transrectal ultrasound-guided needle sextant and two TZ biopsies of the prostate. Total and TZ volumes of the prostate were measured (prolate ellipsoid method). From this cohort, all patients in whom a benign disease was found after the first set of biopsies underwent a second similar set of biopsies within 6 weeks. Only patients with PCa were included in this study, whether diagnosed on first or repeat biopsy. Uni- and multivariate statistical analysis using the SAS system (Cary, N.C., USA) and ROC curves were used to compare patients in whom the diagnosis was performed after the first set of biopsies and those who required a second set. RESULTS: Of the 1,018 patients, 344 (33.8%) had PCa diagnosed, 285 (28%) after the first set of biopsies, and 59 (8.1%) on repeat biopsy. As compared to patients diagnosed with PCa after the first set of biopsies, patients diagnosed after the second set had larger total prostate and TZ volumes (43.1+/-13.0 vs. 32.5+/-10.6 cm(3), p<0.0001 and 20.5+/-8.3 vs. 12.8+/-6.0 cm(3), p<0.0001). ROC curves showed that total and TZ volumes of 45 and 22. 5 cm(3), respectively, provided the best combination of sensitivity and specificity for discriminating between patients diagnosed with PCa after the first from those diagnosed after a second set. CONCLUSION: In patients with total prostate volume >45 cm(3) and TZ >22.5 cm(3), a single set of sextant biopsies may not be sufficient to rule out PCa. In these patients, a repeat biopsy should be considered in case of a negative first biopsy.

Aged↗
PubMed1999

Domain separation precedes global unfolding of rhodanese.

The enzyme rhodanese was investigated for the conformational transition associated with its urea unfolding. When rhodanese was treated with 0 or 3 M urea, the activity was not significantly affected. 4.25 M urea treatment led to a time-dependent loss of activity in 60 min. Rhodanese was completely inactivated within 2 min in 6 M urea. The 1,1'-bi(4-anilino)naphthalene-5,5'-disulfonic acid fluorescence intensity was not significantly increased during 0, 3, and 6 M urea equilibrations, and the fluorescence was dramatically increased with 4.25 M urea, indicating that hydrophobic surfaces are exposed. After 0 and 3 M urea equilibration, rhodanese was not significantly proteolyzed with trypsin. Treatment with 4.25 M urea led to simultaneous formation of major 12-, 15.9-, 17-, and 21.2-kDa fragments, followed by progressive emergence of smaller peptides. The N termini of the 17- and 21.2-kDa bands were those of intact rhodanese. The N terminus of the 15.9-kDa band starts at the end of the interdomain tether. The 12-kDa band begins with either residue 183 or residue 187. The size and sequence information suggest that the 17- and 15.9-kDa bands correspond to the two domains. The 21.2- and 12-kDa bands appear to be generated through one-site tryptic cleavage. It is concluded that urea disrupts interaction between the two domains, increasing the accessibility of the interdomain tether that can be digested by trypsin. The released domains have increased proteolytic susceptibility and produce smaller peptides, which may represent subdomains of rhodanese.

Anilino Naphthalenesulfonates↗
PubMed1999

Elastin gene expression in benign prostatic hyperplasia.

BACKGROUND: Benign prostatic hyperplasia (BPH) is mainly a stromal process, showing an increased ratio of stromal to epithelial elements, a collagen type III downregulation, and a collagen types I and IV upregulation. Little is known about elastin gene expression in BPH tissues due to difficulties related to extensive alternative splicing of the elastin gene. Therefore, we analyzed and quantified elastin gene expression in BPH. METHODS: A competitive reverse transcriptase-polymerase chain reaction (competitive RT-PCR) quantitative technique was used, and a quantitative elastin mRNA analysis with normal (n = 10) and BPH (n = 12) tissues was performed with two newly designed elastin primers. Small tissue samples (4-8 mg) were homogenized and sonicated, and cDNA was synthesized from mRNA using a RT reaction. Various target (wild-type) elastin cDNAs with unknown concentrations were competitively coamplified with known serial dilutions of the control mutant template, differing from the target cDNA by a short deletion. Gel fractions and computerized densitometry, were performed and cDNA concentration was calculated by linear regression. RESULTS: The primers identified in our study (BOB-1 and BOB-2) accurately amplified a consistent length of the elastin cDNA, avoiding areas of alternative splicing. The average elastin mRNA concentration in BPH tissues was 53 attomole/mg +/- 11.6 vs. 140.6 attomole/mg +/- 19.6 in normal prostatic tissue (P = 0.019). The variation within every sample was less than 10%. CONCLUSIONS: Our observations suggest a significant downregulation (70%) of the elastin mRNA gene in the transition zone of BPH patients.

Aged↗
PubMed1999

The effect of a hydrophobic N-terminal probe on translational pausing of chloramphenicol acetyl transferase and rhodanese.

The effect on translational pausing of a hydrophobic probe, coumarin, at the N terminus of nascent peptides was investigated. Two different proteins, bacterial chloramphenicol acetyltransferase and bovine rhodanese, were synthesized by coupled transcription/translation in a cell-free system derived from Escherichia coli. Protein synthesis was initiated with N-formyl-Met-tRNAf or N-acetyl-S-coumarin-Met-tRNAf. Cotranslational incorporation of the coumarin derivative generated nascent polypeptides with a hydrophobic residue at their N termini. The effect of the two N-terminal groups on the size distribution and quantity of the peptides formed by translational pausing was investigated. The N-terminal coumarin caused an accumulation of nascent chloramphenicol acetyltransferase peptides in the mass range of 3.5-4.0 kDa that reflects a delay in translation at this point. No similar effect on rhodanese pause-site peptides was observed. This effect on translational pausing cannot be explained by either mRNA secondary structure or rare codons and tRNA abundance. It is suggested that the effect of N-terminal coumarin on translational pausing is the result of the interaction of the nascent peptide with components of the large ribosomal subunit along the path it follows between the peptidyl transferase center and the exit site on the distal surface.

Animals↗
PubMed1999

Functional dissection of the transmitter module of the histidine kinase NtrB in Escherichia coli.

Signal transduction by two-component systems involves phosphorylation and thereby activation of the response regulator by the cognate histidine kinase. Bifunctional histidine kinases have two opposing activities: depending on the environmental stimuli they either promote phosphorylation or stimulate the rapid dephosphorylation of the response regulator. To determine the mechanism of this switch, we analyzed the domain organization of the bifunctional histidine kinase NtrB. Based on sequence alignments with other histidine kinases and a deletion analysis, we defined three separate subdomains of the transmitter module, the H domain (amino acids 123-221), the N domain (amino acids 221-269), and the G domain (amino acids 269-349). The transmitter module, when separately expressed, exhibited a constitutive positive phenotype. In contrast, in the absence of the G domain, the H domain exhibits a constitutive negative phenotype. This negative regulatory activity of the H domain is inhibited by the G domain. The G domain could be physically uncoupled; when coexpressed with the H-N fragment, the constitutive positive phenotype of the transmitter was restored. We demonstrate, in vitro, that the constitutive negative phenotype of the fragments lacking the G domain is caused by stimulation of dephosphorylation of the response regulator NtrC-P. Based on our analysis, we suggest that the function of the sensor domain is to control the interaction of the H and G domains. If these subdomains interact, NtrB acts as a positive regulator; if they cannot interact, NtrB acts as a negative regulator.

Bacterial Proteins↗
PubMed1999

Bioavailability of trospium chloride after intravesical instillation in patients with neurogenic lower urinary tract dysfunction: A pilot study.

Oral drug treatment of detrusor overactivity often causes undesirable side effects in other organs. For some patients, in particular those with neurogenically induced detrusor overactivity (detrusor hyperreflexia), the tolerance level for adverse effects is low and oral treatment may become ineffective. Intravesical administration of the drug can diminish the side effects or increase treatment effectivity in patients who are (partially) refractory to oral treatment because the relative concentration of the drug is increased in the target organ and decreased in the circulation. Six men (19-34 years old) with traumatic spinal cord lesions between C2 and Th11 were randomized to intravesical instillation with 15 or 30 mg trospium chloride in 40 ml saline into the empty bladder. Catheterization was postponed until at least 3 h after instillation, and fluid intake was not allowed during the first 4 h. Blood samples were taken before and 11 times after instillation; the last sample 12 h post instillation. Four positive samples were found in three patients: 0.10 ng/ml after 1 h and 0.13 ng/ml after 2(1/2) h in two patients with 15 mg, and 0.24 ng/ml after 30 min and 0.70 ng/ml after 6 h in one patient with 30 mg instilled trospium chloride. Three adverse effects were reported and were rated as probably not related to the drug. It is concluded that intravesically instilled trospium chloride is not absorbed into the circulation in significant amounts and, thus, it may be expected that this mode of administration will improve the efficacy of trospium chloride therapy by reducing the side effects. Neurourol. Urodynam. 18:447-453, 1999.

Adult↗
PubMed1999

[Detrusor myectomy (autoaugmentation) in the treatment of hyper-reflexive low compliance bladder].

After unsuccessful medical treatment of a neurogenic hyperreflexive bladder dysfunction further treatment options are the ileal bladder augmentation, the detrusor-myectomy (bladder auto-augmentation) and the sacral root deafferentation. All techniques lead to a low-pressure bladder with enlarged storage volume. The authors here report about their personal experience with the detrusor myectomy in 62 patients with hyperreflexive neurogenic bladder dysfunction from 1989 until 1998. Indication, surgical technique, and long-time results are presented.

Adult↗
PubMed1999

Co-translational folding.

Nascent proteins appear to fold co-translationally. The ribosome itself may function as a chaperone, providing a sheltered environment in which the nascent peptide is protected from aggregation and degradation, and in which folding into the tertiary structure is facilitated by interactions both with ribosomal proteins and with specific segments of the ribosomal RNA.

Amino Acid Sequence↗