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J Schaefer

Publications and source records attributed to J Schaefer.

At least 19 recordsLinked to original sources
PubMed2006

An experiential mind-body approach to the management of medically unexplained symptoms.

This article outlines an experiential mind-body framework for understanding and treating patients with medically unexplained symptoms. The model relies on somatic awareness, a normal part of consciousness, to resolve the mind-body dualism inherent in conventional multidisciplinary approaches. Somatic awareness represents a guiding healing heuristic which allows for a linear treatment application of the biopsychosocial model. The heuristic acknowledges the validity of the patient's physical symptoms and identifies psychological and social factors needed for the healing process. Somatic awareness is used to direct changes in coping styles, illness beliefs, medication dependence and personal dynamics that are necessary to achieve symptom control. The mind-body concept is consistent with and supported by neurobiological models which draw on central nervous system mechanisms to explain medically unexplained symptoms. The concept is also supported by a recent hypothesis concerning the role peripheral connective tissue may play in influencing illness and well-being. Finally, somatic awareness is described as having potential to enhance understanding and conscious use of inner healing mechanisms at the basis of the placebo effect.

Humans↗
PubMed2005

[Evaluation of image quality of the Iso C3D image processor in comparison to computer tomography. Use in the pelvic area].

Intraoperative 3-D visualization using the Siremobil Iso C(3D) (Siemens, Erlangen, Germany) has been approved for use in spine and long bone surgery since its recent clinical launch. In preparation for the clinical use of the Siremobil Iso C(3D) in pelvic surgery, the aim of this study was to grade the quality of visualization in comparison with the gold standard of computer tomography in four therapy relevant pelvic regions in eight human cadavers, including SI screws to exemplify implants in the dorsal pelvic ring. Besides the influence of the body mass index and the interference of metal artefacts, visualization quality was evaluated in different pelvic regions (sacroiliac joint, acetabulum, femoral neck and anterior pelvic ring) using a score with five subgroups, rating the applicability of Siremobil Iso C(3D) in pelvic surgery. The grading of image quality in comparable standard projections was performed independently by three surgeons and three radiologists.Visualization quality appeared sufficient for both intraoperative and postoperative control in cases with a known preoperative diagnosis. There was no influence of body mass index found in any of the eight cadavers. Implants positioned in the dorsal pelvic ring reduced visualization quality, but sufficient estimation of bony structures was still possible. For primary diagnostics, computer tomography remains a clearly superior option due to better image quality. For intraoperative control of the reduction and positioning of implants in pelvic surgery, however, the additional intraoperative use of Siremobil Iso C(3D) is considered to offer clear advantages over current 2-D C-arm visualization tools.

Cadaver↗
PubMed2005

[Comparison of conventional full spine radiographs and fluoroscopic scanning method in young patients with idiopathic scoliosis].

PURPOSE: Evaluation of low-dose full spine radiographs using fluoroscopic images for the assessment of the Cobb angle measurement in patients with scoliosis. MATERIAL AND METHODS: Twenty-one consecutive patients (aged 10 - 27 years, mean age 14 years) with a conventional full spine examination (film speed class 800) underwent a follow-up exam using digital pulsed fluoroscopy (Multi Diagnost 4, Philips Medical Systems, Eindhoven, The Netherlands). The mean follow-up was 9 months. During a synchronized scan with a C-arm speed of 4 cm/sec fluoroscopic images were stored with a pulsed frequency of 3 images per second. The single images were merged and reconstructed to one image with the software Easy Spine (Philips medical Systems, Eindhoven, The Netherlands). The corresponding dose-area product values (DAP) of both methods were compared. Three independent observers assessed Cobb angles and image quality for each technique. RESULTS: The mean DAP values for conventional imaging was 94.9 cGy x cm (2) and for fluoroscopy 7.8 cGy x cm (2), respectively. A significant dose reduction of 91.8 % (CI 91 % to 95 %) was calculated. The average absolute angle difference between the observers was found to be 2.7 degrees for conventional imaging and 2.4 degrees for the fluoroscopic method. Interobserver standard deviation of 2.9 degrees was lower than the 5.3 degrees for conventional images. Image quality was better in the conventional images. CONCLUSION: Using the scanning method, we could achieve a mean reduction of the radiation dose of 92 %, while the accuracy of the Cobb angle measurements was comparable for both techniques despite of reduced image quality of digital fluoroscopy.

Adolescent↗
PubMed2005

Improving medical emergency team (MET) performance using a novel curriculum and a computerized human patient simulator.

PROBLEM: Advance cardiac life support (ACLS) training does not address coordination of team resources to improve the ability of teams to deliver needed treatments reliably and rapidly. Our objective was to use a human simulation training educational environment to develop multidisciplinary team skills and improve medical emergency team (MET) performance. We report findings of a crisis team training course that is focused on organization. SETTING: Large center for human simulation training at a university affiliated tertiary care hospital. PARTICIPANTS: Ten courses were delivered and 138 clinically experienced individuals were trained (69 critical care nurses, 48 physicians, and 21 respiratory therapists). All participants were ACLS trained and experienced in responding to cardiac arrest situations. COURSE DESIGN: Each course had four components: (1) a web based presentation and pretest before the course; (2) a brief reinforcing didactic session on the day of the course; (3) three of five different simulated scenarios; each followed by (4) debriefing and analysis with the team. Three of five simulator scenarios were used; scenario selection and order was random. Trainees did not repeat any scenario or role during the training. Participants were video recorded to assist debriefing. Debriefing focused on reinforcing organizational aspects of team performance: assuming designated roles independently, completing goals (tasks) assigned to each role, and directed communication. MEASURES FOR IMPROVEMENT: Participants graded their performance of specific organizational and treatment tasks within specified time intervals by consensus. Simulator "survival" depended on supporting oxygenation, ventilation, circulation within 60 seconds, and delivering the definitive treatment within 3 minutes. EFFECTS OF CHANGE: Simulated survival (following predetermined criteria for death) increased from 0% to 89%. The initial team task completion rate was 10-45% and rose to 80-95% during the third session. LESSONS LEARNT: Training multidisciplinary teams to organize using simulation technology is feasible. This preliminary report warrants more detailed inquiry.

Computer Simulation↗
PubMed2004

[Expandable cages: biomechanical comparison of different cages for ventral spondylodesis in the thoracolumbar spine].

INTRODUCTION: Due to a recent increase in the commercial availability of expandable cages for vertebral body replacement, this study was designed to gain more information about their biomechanical properties. All three expandable cages evaluated in this study are approved for clinical use, but little knowledge about their biomechanical properties exists. MATERIAL AND METHODS: Human thoracolumbar spines (T11 to L3) ( n=32) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method. Three-dimensional displacement was measured using an optical measurement system. All motion segments were tested intact. After L1 corporectomy, cages were implanted and the following groups ( n=8 each) were tested: (1) meshed titanium cage (nonexpandable cage, DePuy Acromed), (2) X-tenz (expandable cage, DePuy Acromed), (3) Synex (expandable Cage, Synthes), and (4) VBR (expandable cage, Ulrich). Finally, posterior stabilization and posterior-anterior stabilization, both using USS (Synthes), and anterior plating (LCDCP, Synthes) was applied. The mean apparent stiffness values, ranges of motion, and neutral and elastic zones were calculated from the corresponding load/displacement curves. RESULTS: No significant differences were found between the in vitro biomechanical properties of expandable and nonexpandable cages. Compared to the intact motion segment, isolated anterior stabilization using cages and anterior plating significantly decreased stiffness and increased range of motion in all directions. Additional posterior stabilization significantly increased stiffness and decreased range of motion in all directions compared to the intact motion segment. Combined anterior-posterior stabilization demonstrated the greatest stiffness results. CONCLUSION: Design variations of expandable cages for vertebral body replacement do not show any significant effect on the biomechanical results. There was no significant difference found, between the biomechanical properties of expandable and non-expandable cages. After corporectomy, isolated implantation of expandable cages plus anterior plating was not able to restore normal stability of the motion segment. As a consequence, isolated anterior stabilization using cages plus LCDCP should not be used for vertebral body replacement in the thoraco-lumbar spine.

Biomechanical Phenomena↗
PubMed2004

Variable penetrance of a familial progressive necrotising encephalopathy due to a novel tRNA(Ile) homoplasmic mutation in the mitochondrial genome.

INTRODUCTION: We present a family comprising a clinically normal mother and two daughters, each with severe encephalopathy with onset in late childhood. A third daughter had died previously of an earlier onset but neuropathologically similar disease. METHODS: Sequence analysis of the entire mtDNA was carried out in muscle, fibroblasts, and lymphocytes of the affected daughters and unaffected mother. Biochemical analysis of individual respiratory chain enzymes was performed on the same tissues, and on several transmitochondrial cybrid clones containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA. RESULTS: Genetic analyses revealed in both daughters and mother the presence of a novel mutation in the tRNA(Ile) gene of mtDNA, which was homoplasmic in fibroblasts, lymphocytes, and skeletal muscle of the two patients. It was also homoplasmic in fibroblast and skeletal muscle samples of the mother, and approximately 97% heteroplasmic in her lymphocytes. Combined defects of complexes I and IV of the mitochondrial respiratory chain were found not only in fibroblasts of the two probands, but surprisingly also in those of their clinically unaffected mother. The respiratory chain defect segregated in transmitochondrial cybrids containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA, indicating that the latter was responsible for the biochemical phenotype. DISCUSSION: Our results support the concept that homoplasmic mutations in tRNA genes can be responsible for mitochondrial disorders characterised by extremely variable penetrance. Albeit still unexplained, this phenomenon has important consequences in the nosological characterisation, clinical management, and genetic counselling of mitochondrial disorders.

Adolescent↗
PubMed2001

Outpatient mental health care, self-help groups, and patients' one-year treatment outcomes.

OBJECTIVE: To examine the association between the duration and amount of outpatient mental health care, participation in self-help groups, and patients' casemix-adjusted one-year outcomes. METHODS: A total of 2,376 patients with substance use disorders, 35% of whom also had psychiatric disorders, were assessed at entry to treatment and at a one-year follow-up. Information about the duration and amount of outpatient mental health care was obtained from a centralized health services utilization database. RESULTS: Patients who obtained regular outpatient mental health care over a longer interval and patients who attended more self-help group meetings had better one-year substance use and social functioning outcomes than did patients who were less involved in formal and informal care. The amount of outpatient mental health care did not independently predict one-year outcomes. CONCLUSIONS: The duration of outpatient mental health care and the level of self-help involvement are independently associated with less substance use and more positive social functioning. The provision of low intensity treatment for a longer time interval may be a cost-effective way to enhance substance abuse and psychiatric patients' long-term outcomes.

Adult↗
PubMed2001

Failure to express GAP-43 during neurogenesis affects cell cycle regulation and differentiation of neural precursors and stimulates apoptosis of neurons.

GAP-43 is first expressed in proliferating neuroblasts and is required for maturation of neurons. When GAP-43 is not expressed in differentiating embryonal carcinoma P19 cells, reduced numbers of neurons were generated. Here we show that neuronal differentiation is initially disrupted at the onset of cell-cycle arrest in aggregated, proliferating neuronal precursors. The ratio of nestin:beta-tubulin-labeled progeny generated at this stage suggests that the differentiation is asymmetric. Apoptosis of immature neurons subsequently produced was also significantly induced. In vivo, too, proliferation of neuroblasts was significantly reduced in cortex of GAP-43(-/-) mice at E14.5. These data demonstrate that when GAP-43 is not expressed in proliferating neuroblasts, neural differentiation is not initiated appropriately, inducing apoptosis. Moreover, the concurrent inhibition of Ca2+-dependent adhesion between differentiating P19 cells in aggregates implicates GAP-43 in CAM-mediated signaling during neurogenesis, as has been previously shown in growth cones.

Animals↗
PubMed2001

Metal and radionuclide bioremediation: issues, considerations and potentials.

Recent demonstrations of the removal and immobilization of inorganic contaminants by microbial transformations, sorption and mineralization show the potential of both natural and engineered microbes as bioremedial tools. Demonstrations of microbe-mediated mineral formation in biofilms implicate this mode of microbial life in geological evolution and remediation of inorganic contaminants.

Bacteria↗
PubMed2001

Oral vitamin B(12) and high-dose folic acid in hemodialysis patients with hyper-homocyst(e)inemia.

BACKGROUND: Hyper-homocyst(e)inemia is an independent risk factor for atherosclerotic vascular disease in patients with end-stage renal disease (ESRD), although optimal treatment remains unknown. This randomized, double-blind, placebo-controlled study was designed to measure the effect of high-dose oral vitamin B(12) and folic acid on predialysis total homocyst(e)ine levels in patients with ESRD. METHODS: We studied 81 hemodialysis patients who had hyper-homocyst(e)inemia (>16 micromol/L) on varied doses of a multivitamin containing 1 mg of folic acid/day. After screening blood work, all patients were switched to daily multivitamin therapy, including 1 mg of folic acid for four weeks. For all patients, vitamin B(12), 1 mg/day, was added for an additional four weeks. Patients were then randomized to receive four weeks of 0, 5, or 20 mg of folic acid in addition to the multivitamin and vitamin B(12) (all given daily). RESULTS: Screening homocyst(e)ine levels (mean 27.7 micromol/L) decreased by 19.2% after four weeks of treatment with a daily multivitamin containing 1 mg of folic acid (P < 0.001). Homocyst(e)ine levels were reduced further from 22.3 to 18.6 micromol/L (mean reduction 16.7%, 95% CI 11.8 to 21.6%, P < 0.001) after four weeks of therapy with vitamin B(12) (1 mg/day). There was no significant difference in mean reduction of homocyst(e)ine levels after therapy with high-dose folic acid compared with placebo (P = 0.35). CONCLUSIONS: The optimal oral treatment of hyper-homocyst(e)inemia in hemodialysis patients consists of 1 mg of folic acid and 1 mg of oral vitamin B(12) daily. Whether this treatment will lower the risk of future atherosclerotic vascular events remains to be investigated.

Administration, Oral↗
PubMed2000

Coupling between adsorbate vibrations and an electronic surface state

We report direct angle-resolved photoemission measurements of the coupling between the symmetric stretch vibrational mode of adsorbed hydrogen and a surface band on W(110). This coupling is manifested by the surface band being split into two branches at a binding energy comparable to the vibrational mode energy, as confirmed by observation of a dramatic hydrogen/deuterium isotope effect. The electron-phonon coupling parameter lambda is found to be significantly larger than that for bulk W, and to be closely related to the degree of surface localization of the surface state wave function.

Journal Article↗
PubMed2000

Deuterium NMR investigation of an amphotericin B derivative in mechanically aligned lipid bilayers.

The methyl-d(3) amide derivative of the polyene antibiotic amphotericin B was synthesized, assayed for biological activity, incorporated into mechanically aligned bilayers of dipalmitoylphosphatidylcholine (DPPC), and examined by deuterium and phosphorus NMR. The amide derivative has a lesser, but qualitatively similar, biological activity relative to amphotericin B. Incorporation of the amide derivative and ergosterol into aligned DPPC bilayers resulted in a single, stable bilayer phase, as shown by phosphorus NMR of the DPPC headgroups. Deuterium NMR spectra revealed one major (2)H quadrupolar splitting and one major (2)H-(1)H dipolar splitting in the liquid-crystalline phase, consistent with a high degree of alignment and a single, averaged physical state for amphotericin B methyl-d(3) amide in the bilayer. Variations of the quadrupolar and dipolar splittings as a function of macroscopic sample orientation and temperature indicated that the amide derivative undergoes fast rotation about a motional axis that is parallel to the bilayer normal.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

Targeted disruption of GAP-43 in P19 embryonal carcinoma cells inhibits neuronal differentiation. As well as acquisition of the morphological phenotype.

GAP-43 is expressed in proliferating neuroblasts in vivo and in vitro, but its role during early neurogenesis has not been investigated. Here we show that neuroectodermal differentiation stimulated by retinoic acid (RA) in the embryonal carcinoma (EC) line P19 is accompanied by upregulation of GAP-43 expression in neuroepithelial precursor cells. In contrast, when upregulation of GAP-43 expression was prevented in 3 independent P19 lines because of a targeted insertion into the gene, generation of neuroepithelial precursors was inhibited. Consequently, neuronal number was significantly decreased, neuronal morphology was abnormal and fewer than 20% of all neurons were able to initiate neuritogenesis. Extracellular matrix (ECM) was unable to rescue initiation of neuritogenesis in the mutant cells, however those neurites that were extended responded normally to ECM-stimulated neurite outgrowth-promoting signals. These data suggest that GAP-43 function is required for commitment to a neuronal phenotype as well as initiation of neurite extension. However, stimulation of neurite outgrowth by ECM in P19s occurs independently of GAP-43.

Animals↗
PubMed2000

Conformation of microtubule-bound paclitaxel determined by fluorescence spectroscopy and REDOR NMR.

The conformation of microtubule-bound paclitaxel has been examined by fluorescence and solid-state NMR spectroscopy. A fluorescent derivative of paclitaxel, 3'-N-debenzoyl-3'-N-(m-aminobenzoyl)paclitaxel (N-AB-PT), was prepared by semisynthesis. No differences in the microtubule-promoting activity between N-AB-PT and paclitaxel were observed, demonstrating that addition of the amino group did not adversely affect the ligand-receptor association. The distance between the fluorophore N-AB-PT and the colchicine binding site on tubulin polymers was determined through time-resolved measurements of fluorescence resonance energy transfer to be 29 +/- 2 A. The absorption and emission spectra of N-AB-PT bound to microtubules and in various solvents were measured. A plot of the Stokes shift as a function of solvent polarity was highly unusual. The Stokes shift increased linearly with solvent polarity in protic solvents, which is expected due to the nature of the fluorophore. In aprotic solvents, however, the Stokes shift was invariant with solvent polarity, indicating that the fluorophore was somehow shielded from the effects of the solvent. These data are best explained by considering the solution-state conformational properties of paclitaxel. It is known that paclitaxel adopts different conformations depending on the nature of the solvent, and these fluorescence data are consistent with the molecule adopting a "hydrophobic collapsed" conformation in protic solvents and an "extended" conformation in aprotic solvents. The Stokes shift of microtubule-bound N-AB-PT was within the protic solvent region, demonstrating that microtubule-bound paclitaxel is in a hydrophobic collapsed conformation. Microtubule-bound paclitaxel was also investigated by solid-state NMR. Paclitaxel was labeled with (19)F at the para position of the C-2 benzoyl substituent and with (13)C and (15)N in the side chain. Distances between the fluorine and carbon nuclei were determined by REDOR. The distance between the fluorine and the 3'-amide carbonyl carbon was 9.8 +/- 0.5 A, and the distance between the fluorine atom and the 3'-methine carbon was 10. 3 +/- 0.5 A. These spectroscopic data were used in conjunction with molecular modeling to refine the microtubule-bound conformation of paclitaxel and to suggest an alternative orientation of the ligand within the paclitaxel binding site.

Animals↗
PubMed2000

Overcoming remoteness in CME videoteleconferencing: "I want my MD TV".

Videoteleconferencing in continuing medical education (CME) is here to stay. In the growing health care climate, with increased mergers of institutions and facilities, education's reliance on this medium promises to grow. This project summary describes one large metropolitan institution's effort to improve the commitment to, use in, and effectiveness of videoteleconferencing in its multisite delivery of CME programs. The institution is a nationally renowned interdisciplinary teaching and research hospital health center, with more than 1000 beds. The medical staff numbers more than 1100. The CME program, accredited by the Medical Society of the State of New York, sponsors more than 44 activities a year, awarding over 13,000 certified category 1 CME credits and serving a combined total of over 806 participating MDs and DOs. A study team comprised of the Medical Board Education Committee's Chair-director of CME, an adult education consultant-professor of adult education, and a visual literacy consultant undertook a year-long qualitative research project to explore issues, unearth dilemmas in practice, and generate recommendations for future policy and practice related to videoteleconferencing. The primary objective was to derive strategies for enhancing the educational effectiveness and community building potential of videoteleconferencing at the hospital-health center.

Computer Literacy↗
PubMed2000

An evaluation of employee exposure to volatile organic compounds in three photocopy centers.

Personal and area samples from three copy centres were collected in thermal desorption tubes and analyzed using gas chromatography-mass spectrometry. Real-time personal total volatile organic compounds (TVOC) were measured using a data-logging photoionization detector. Fifty-four different VOCs were detected in the area samples. The maximum concentration measured was 1132.0 ppb (toluene, copy center 3, day 1). Thirty-eight VOCs were detected in the personal samples and concentrations ranged from 0.1 ppb (1,1-biphenyl, p-dichlorobenzene, propylbenzene, styrene, and tetrachloroethylene) to 689.6 ppb (toluene). Real-time TVOC measurements indicated daily fluctuations in exposure, ranging from <71 to 21,300 ppb. The time-weighted average exposures for the photocopier operators on days 1 and 2 were 235 and 266 ppb and 6155 and 3683 ppb, in copy centers 2 and 3, respectively. Personal exposure measurements of individual VOCs were below accepted occupational standards and guidelines. For example, the maximum concentration was 0.3% of the permissible exposure limits (toluene, copy center 3). Exposures were highest in copy center 3; this is likely due to the presence of offset printing presses. It is concluded that photocopiers contribute a wide variety of VOCs to the indoor air of photocopy centers; however, exposures are at least 100 times below established standards.

Air Pollution, Indoor↗