Quantification of mechanical properties in long-term in vivo used silicone catheter lines according to DIN 10555-3.

BACKGROUND: Totally implantable central venous access port devices are crucial for intravenous application of chemotherapeutics and long-term therapy for chronic disease. Common complications include thrombosis and device fracture related to altered material properties through exposure in situ. This study exhibits whether uniaxial tensile properties (DIN 10555-3) of in vivo used catheters prove inferior to unused catheters. MATERIAL AND METHODS: 5 unused, originally packed silicone catheters were cut into 6 segments of 50 mm: 3 segments each were cleaned via cleaning solution (n = 15) while 3 segments were left unattended (n = 15). Distal segments (50 mm) of long-term in vivo used silicone catheters were cleaned before testing (n = 33). Overall mechanical behavior was tested in a custom-made self-centering, torsion free carrier. Maximum force stress at failure, strain at failure and Young's modulus were determined and statistically analyzed. FINDINGS: Unused catheters showed no significant difference in testing. in vivo used catheters exhibited 20% lower maximal force than unused catheters (p < 0.001), strain at break (p ã€ˆ0,001), and 7% higher elastic modulus (p = 0.004; power: 0.845). Due to a constant cross section area, stress at failure was proportional to maximum force (p < 0.001). Relation between determined parameters and dwell times was non-significant. INTERPRETATION: In vivo long-term used silicone catheters showed significantly lower ultimate strength than unused ones. It is likely that in situ altering changes the mechanical properties of catheters and may potentially lead to failure.

A NEW TL-DOS NEUTRON DOSEMETER FOR MEASUREMENTS OF THE PERSONAL DOSE EQUIVALENT HP(10).

A new thermoluminescence albedo dosemeter with improved properties is developed as part of the TL-DOS project. The dosemeter measures the neutron and photon whole-body dose of radiation workers. The TL-DOS neutron dosemeter is presented and its results of well-known field measurements as well as field calibrations are shown. Its advantages, such as its potential to measure the high-linear energy transfer peaks, its improved detector sensitivity and long detector lifetime, are explained. The new dosemeter is compared to a thermoluminescence albedo dosemeter already used in routine dosimetry in Germany.

Control of bovine tuberculosis in a farmed red deer herd in England.

This report describes how Mycobacterium bovis infection was controlled and eventually eradicated in a farmed red deer herd in the north of England, following sustained tuberculin skin testing supplemented with serological (antibody) tests over a period of approximately two years. By taking advantage of the anamnestic antibody response produced by the skin test to detect skin test-negative, antibody-positive infected individuals, a total of 35 additional animals were identified, including 2 with gross visible lesions typical of bovine tuberculosis (BTB). Without detection and removal, these animals would have posed a continued risk of BTB persistence within the herd and potentially contributed to the spread of infection from deer into wildlife and surrounding cattle farms in an area of low BTB incidence. This case supports the use of ancillary diagnostic serological tests to speed up the resolution of incidents of BTB caused by M bovis in captive deer herds.

INTERCOMPARISON OF EYE LENS DOSEMETERS.

An intercomparison of eye lens dosemeters has been conducted in terms of the quantity Hp(3). For the first time, besides photon radiation also beta radiation qualities were included. Three dosemeter types designed for the quantity Hp(3) and ten for Hp(0.07) took part in the intercomparison. As shown in a previous intercomparison for photon radiation only, the dosemeters designed for Hp(0.07) and calibrated in terms of Hp(3) performed well in photon radiation fields. But for beta radiation, it turned out that Hp(0.07) dosemeters over-responded up to a factor of 5 000 (with respect to the true Hp(3) dose) in the medium beta energy range (85Kr with a beta endpoint energy of 0.69 MeV), while some Hp(3) dosemeters performed quite well. For medium (57 keV) and high (662 keV) energy photon radiation, all dosemeter types showed response values well within the trumpet curve according to the current draft of ISO 14146.

A THIN-LAYER LIF THERMOLUMINESCENCE DOSEMETER SYSTEM WITH FAST READOUT FOR THE USE IN PERSONAL DOSIMETRY SERVICES.

A newly developed thermoluminescence dosemeter system is presented that is suitable for application in fields where personal monitoring of a large number of users is required. The system presented here is intended to be used as the upcoming main dosemeter for whole body dosimetry at the dosimetry service of the MPA NRW (Germany) with ∼110,000 evaluations per month.

Development and evaluation of a non-peptidic ligand for the molecular imaging of inflammatory processes using S100A9 (MRP14) as a novel target.

The establishment of novel molecular imaging tools to monitor the local activity of inflammation remains an interdisciplinary challenge. Our target, the alarmin S100A9, one subunit of the heterodimer S100A8/S100A9 (calprotectin), is locally secreted in high concentrations from immigrated and activated phagocytes at local sites of inflammation. Calprotectin is already a well established serum biomarker for many inflammatory disorders. Here we show the development and first evaluation of the novel S100A9 specific molecular imaging probe for optical imaging of local inflammatory activity in vivo.

Albedo neutron dosimetry in Germany: regulations and performance.

Personal neutron dosimetry has been performed in Germany using albedo dosemeters for >20 y. This paper describes the main principles, the national standards, regulations and recommendations, the quality management and the overall performance, giving some examples.

Current methods for estimating the rate of photorespiration in leaves.

Photorespiration is a process that competes with photosynthesis, in which Rubisco oxygenates, instead of carboxylates, its substrate ribulose 1,5-bisphosphate. The photorespiratory metabolism associated with the recovery of 3-phosphoglycerate is energetically costly and results in the release of previously fixed CO2. The ability to quantify photorespiration is gaining importance as a tool to help improve plant productivity in order to meet the increasing global food demand. In recent years, substantial progress has been made in the methods used to measure photorespiration. Current techniques are able to measure multiple aspects of photorespiration at different points along the photorespiratory C2 cycle. Six different methods used to estimate photorespiration are reviewed, and their advantages and disadvantages discussed.

A whole-body dosimetry system for personal monitoring based on hot-pressed thin layer TLD.

We are introducing a new high-capacity thermoluminescent dosemeter (TLD) system to measure the whole body values of H(p)(10) and H(p)(0.07) from photons for use in individual monitoring services. Small and light-weight badges allow a convenient application in a wide variety of workplaces with photon radiation from 20 keV to at least 7 MeV. The main advantage of this system will be the large capacity of ∼ 100,000 dosemeters per month at costs equivalent to the current film monitoring. The hot-pressed thin-layer TL detector (LiF:Mg,Ti) is welded onto an aluminium substrate and provided with a data matrix code for automatic processing. The detector holder has been optimised, that no additional filter is necessary. The new designed TLD reader with readout times <10 s will allow a large throughput and a considerable degree of automation.

A pilot open trial of brief psychodynamic psychotherapy for panic disorder.

This is a complete report of an open trial of manualized psychodynamic psychotherapy for treatment of panic disorder, Panic-Focused Psychodynamic Psychotherapy (PFPP). Twenty-one patients with PD were entered into a trial of twice-weekly, 24-session treatment. Sixteen of 21 experienced remission of panic and agoraphobia. Treatment completers with depression also experienced remission of depression. Improvements in symptoms and in quality of life were substantial and consistent across all measured areas. Symptomatic gains were maintained over 6 months. This report was prepared specifically to describe 6-month follow-up on these patients. Psychodynamic psychotherapy appears to be a promising nonpharmacological treatment for panic disorder.

How treating psychoanalysts respond to psychotherapy research constraints.

The psychoanalytic community increasingly recognizes the importance of research on psychoanalytic treatments, yet a significant number of psychoanalysts continue to believe that research is either irrelevant to psychoanalysis or impossible to accomplish. Psychoanalysts who accept the value of research express concern that intrusions required by research protocols create significant distortions in the psychoanalytic process. The authors, all psychoanalysts, are studying the outcome of a brief (twenty-four-session) psychodynamic treatment of panic disorder. They report their experiences and struggles with the intrusions of videotaping, working with a treatment manual, and time-limited treatment. This research process required them to question old beliefs and to confront feelings of disloyalty toward their analytic training and identity, particularly with regard to keeping a "clean field" and routinely performing long-term analysis of character. The therapists' psychoanalytic knowledge, however, emerged as crucial for them in managing specific research constraints. Despite concerns about providing inadequate treatment, therapists were found to engage patients with psychoanalytic tools and focus in vibrant and productive therapies that led to significant improvements in panic symptoms and associated quality of life. The authors suggest that psychoanalysts have been overestimating the potential damage of research constraints on psychoanalytic process and outcome.

Open trial of psychodynamic psychotherapy for panic disorder: a pilot study.

OBJECTIVE: This report contains preliminary data from an open trial of brief psychodynamic psychotherapy for panic disorder. METHOD: Fourteen patients with primary DSM-IV panic disorder completed a 24-session, twice-weekly course of psychodynamic psychotherapy. Other psychiatric treatment was not permitted throughout the 12-week treatment period and the 6-month follow-up. Symptoms were assessed at baseline, treatment termination, and 6-month posttermination follow-up (40 weeks). RESULTS: Statistically significant, clinically meaningful improvements appeared in panic, depression, anxiety, and functional impairment both at treatment termination and at 6-month follow-up. CONCLUSIONS: Psychodynamic monotherapy can be used successfully to retain and treat patients with panic disorder. Psychodynamic interventions warrant further study for patients with panic disorder.

What is a deep interpretation?

Important differences are emerging regarding the place where analysts believe the most meaningful analytic work takes place. One area that highlights these distinct ways of working is the analyst's view of deep interpretations. Models underlying the differing perspectives on this issue are presented, along with an extended clinical example that illustrates the importance of considering, in formulating analytic interventions, the concept of a structured mind. A view of the analytic process that accords the patient's perspective greater privilege is introduced.

Oedipal dynamics in panic disorder.

Both research and clinical work have revealed factors that can lead to the onset and persistence of panic disorder. Preoedipal conflicts intensify the danger of oedipal longings for panic patients. Competition with the same-sex parent is linked with angry preoedipal fantasies and associated fears of disruption in attachments. Fantasies or actual successes can thus trigger panic episodes. Regression to a helpless, dependent state such as panic defends against the danger of aggressive, competitive fantasies and actual achievements. However, the regressive state can also be experienced as dangerous, and can be linked with frightening homosexual fantasies. A reactive aggressive oedipal stance can sometimes result, triggering escalating turmoil. The panic episode serves a series of compromise formations in dealing with these conflicted wishes.

Theory and technique in psychodynamic treatment of panic disorder.

The authors elaborate psychodynamic factors that are relevant to the treatment of panic disorder. They outline psychoanalytic concepts that were employed to develop a psychodynamic approach to panic disorder, including the idea of unconscious mental life and the existence of defense mechanisms, compromise formations, the pleasure principle, and the transference. The authors then describe a panic-focused psychodynamic treatment based on a psychodynamic formulation of panic. Clinical techniques used in this approach, such as working with transference and working through, are described. Finally, a case vignette is employed to illustrate the relevance of these factors to panic disorder and the use of this treatment.(The Journal of Psychotherapy Practice and Research 1999; 8:234-242)

Fractionated administration of high-dose cyclophosphamide: influence on dose-dependent changes in pharmacokinetics and metabolism.

PURPOSE: The alkylating agent cyclophosphamide (CP) is a prodrug that is metabolized to both cytotoxic and inactive compounds. We have previously shown that following dose escalation from conventional-dose (CD) to high-dose (HD) levels; the fraction of the dose cleared by bioactivation is significantly decreased (66% versus 48.5%) in favor of inactivating elimination pathways when the HD is given as a single 1-h infusion. Based on the concept of bioactivating enzyme saturation with increasing doses, we investigated the influence of fractionated application of HD-CP on dose-dependent changes in metabolism. PATIENTS AND METHODS: Plasma concentrations of CP (measured by high-performance liquid chromatography, HPLC) and urinary concentrations of CP and its major metabolites (quantified by [31P]-nuclear magnetic resonance spectroscopy; [31P]-NMR spectroscopy), were determined in four patients with high-risk primary breast cancer who received adjuvant chemotherapy including both CD-CP (500 mg/ m2 infused over 1 h) and split HD-CP (50 mg/kg infused over 1 h on each of 2 consecutive days (d): d1 and d2. RESULTS: (Data are given as mean values for CD and d1/d2 of HD, respectively). Systemic clearance (CL) of CP was similar during CD and d1 of HD, but significantly increased on d2 of HD (CL: 83 and 78/115 ml/min; P < 0.01 for d1 versus d2). The latter was translated into an increase in formation CL of both active (+ 16.4 ml/min) and inactive metabolites (+ 17.6 ml/ min) and reflects autoinduction of metabolism. As compared with CD-CP, no statistically significant decrease was observed in the relative contribution of bioactivation CL to overall CL during both days of HD (63% versus 57%/53%). Recovery of intact CP in 24-h urine corresponded to 24%, 29%, 22% of the dose (P < 0.05 for d1 versus d2 of HD). CONCLUSIONS: Following dose escalation of CP, dividing the high dose over 2 days instead of one single infusion may favorably impact the metabolism of CP in terms of bioactivation. In addition, on day 2 of a split regimen, renal elimination of CP is decreased, which implies that more drug is available for metabolism.

X-ray microtomography (microCT) using phase contrast for the investigation of organic matter.

PURPOSE: We show that microtomography (microCT) using synchrotron radiation (SR) can be extended to include X-ray phase contrast, which is two to three orders of magnitude more sensitive than conventional attenuation contrast and better suited for the investigation of specimens consisting chiefly of light elements for photon energies ranging at least from 1 to 100 keV. METHOD: Phase contrast is generated by placing the specimen in one of the interfering beams of an X-ray interferometer. With use of 12-keV X-rays, phase projections of the specimen are recorded at 180 or 360 angular settings equally spaced between 0 and 180 degrees. One phase projection consists of four pairs of "associated" radiograms in the sense that one is taken with and the other without the specimen in the beam. Between pairs a parallel-sided phase-shifter plate is rotated for changing the relative phase of the two interfering beams by multiples of pi/2 rad. By calculating phase-weighted sums of all associated pairs of radiograms, true phase-shift projections are obtained for all angular settings of the specimen, which are then reconstructed. RESULTS: Three-dimensional images have been obtained from rat cerebrum and rat trigeminal nerve, showing cell structures at 8- to 15-micron spatial resolution. Gray and white matter of cerebrum and neurons in the trigeminal nerve are clearly visible. CONCLUSION: X-ray phase-contrast microCT is becoming a valuable tool for studies of organic samples in medicine and biology.

Dose escalation of cyclophosphamide in patients with breast cancer: consequences for pharmacokinetics and metabolism.

PURPOSE: The alkylating anticancer agent cyclophosphamide (CP) is a prodrug that undergoes a complex metabolism in humans producing both active and inactive metabolites. In parallel, unchanged CP is excreted via the kidneys. The aim of this study was to investigate the influence of dose escalation on CP pharmacokinetics and relative contribution of activating and inactivating elimination pathways. PATIENTS AND METHODS: Pharmacokinetics of CP were assessed in 12 patients with high-risk primary breast cancer who received an adjuvant chemotherapy regimen that included four courses of conventional-dose CP (500 mg/m2 over 1 hour every 3 weeks) followed by one final course of high-dose CP (100 mg/kg over 1 hour). Plasma concentrations of CP were analyzed by high-performance liquid chromatography (HPLC), 24-hour urinary concentrations of CP, and its inactive metabolites (carboxyphosphamide, dechloroethylcyclophosphamide [dechlorethylCP], ketocyclophosphamide [ketoCP]) were determined by 31-phosphorus-nuclear magnetic resonance (31P-NMR)-spectroscopy. RESULTS: There was no difference in dose-corrected area under the concentration-time curve (AUC) (216 v 223 [mumol.h/[mL.g]), elimination half-life (4.8 v 4.8 hours), systemic clearance (79 v 77 mL/min) and volume of distribution (0.49 v 0.45 L/kg) of CP between conventional- and high-dose therapy, respectively. However, during high-dose chemotherapy, we observed a significant increase in the renal clearance of CP (15 v 23 mL/min; P < .01) and in the formation clearance of carboxyphosphamide (7 v 12 mL/min; P < .05) and dechloroethylCP (3.2 v 4.2 mL/min; P < .05), whereas metabolic clearance to ketoCP remained unchanged (1.3 v 1.2 mL/min). Consequently, metabolic clearance to the remaining (reactive) metabolites decreased from 52 to 38 mL/min (P < .001). The relative contribution of the different elimination pathways to overall clearance of CP demonstrated wide interindividual variability. CONCLUSION: Overall pharmacokinetics of CP are apparently not affected during eightfold dose escalation. However, there is a shift in the relative contribution of different clearances to systemic CP clearance in favor of inactivating elimination pathways, thereby indicating saturation of bioactivating enzymes during dose escalation. Besides individual enzyme capacity, hydration and concomitant medication with dexamethasone modulated CP disposition.