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31.
The analysis of bone structure in vivo is an important goal in osteoporosis, because the determination of bone mineral density
alone is insufficient to predict whether an individual patient will eventually suffer an osteoporotic fracture or not. An
additional structural analysis may significantly improve the statistical assessment of fracture risk. In this study we present
a method to generate realistic although enlarged 3D phantoms of trabecular bone. These phantoms are useful in characterizing
the potential of in vivo imaging procedures for the analysis of bone structure and to verify textural or structural analysis
methods applied to these images. Our phantoms are based on a real trabecular bone specimen that was converted to a plastic
model using the technique of stereolithography. The trabecular network is modeled by hydroxyapatite. Limitations of the stereolithographic
process prevent the generation of exact 1:1 replicas of the real bone. A histomorphometric analysis of μCT scans of the phantoms
showed that an excellent replication of the bone structure could be achieved in phantoms enlarged by a factor of 2.5 with
"trabecular" hydroxyapatite concentrations up to 400 mg/cm3. In order to demonstrate the usefulness of our phantoms, we investigated one of them with various thin-slice CT protocols
using clinical single- and multi-slice spiral CT scanners. The enlargement of the phantoms limits their use on high spatial
resolution CT scanners (resolution >20 lp/cm). The limited hydroxyapatite concentration requires enhanced exposure rates for
the phantoms scans to offset the larger impact of noise due to the lower contrast in the phantoms.
Electronic Publication 相似文献
32.
B Risberg 《Acta chirurgica Scandinavica》1976,142(8):589-591
The records of 57 patients with abdominal stab wounds, treated at the Surgical Departments of the Sahlgrenska Hospital, G?teborg, between 1969-1974, were revised. Fifty-five patients were males and 2 females. The wounds were situated in the upper abdomen in 72% of the patients. Forty-nine patients were treated with an explorative laparotomy and the findings were considered to be negative in 31% of these patients. Liver injuries were found in 45% of the operated patients. No complications occurred in the patients with negative laparotomy findings. One patient with multiple intra-abdominal lesions succumbed from an irreversible septic shock. 相似文献
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34.
Opinion statement Psychiatric symptoms are common to many autoimmune disorders. Patients often will have mood disorders, anxiety, cognitive
deficits, delirium, and psychosis. These symptoms may reflect the direct or indirect effect of the autoimmune disorder on
the central nervous system, may be related to medications used to treat the disorder, or may be a direct psychologic impact
from suffering with the autoimmune disorder. Accurately recognizing the psychiatric component and generating a differential
diagnosis is a complex task for the treating physician. Treatment of the psychiatric component to the disorder often will
include addressing steroid induced side effects, psychotropic medications, psychotherapy, patient and family education, and
a strong physician-patient relationship. 相似文献
35.
B. Risberg O. St l K. Bjelkenkrantz T. Hatschek G. Franz n S. Arvidsson B. Nordenskj ld 《Acta oncologica (Stockholm, Sweden)》1985,24(6):537-544
Sections with a thickness of 50 μm from 34 formalin fixed, and paraffin embedded tumours were deparflin-ized and hydrated and the cells were disaggregated with pepsin. The cells were stained with Hoechst 33258 and a rapid method for static fluorometry was used. DNA ploidy and the fraction of cells in S-phase were estimated and compared with results obtained with freshly prepared cells. The coefficients of variation for the tumour stem-lines for both the fresh and the embedded material were approximately 6 per cent. There was a good correlation between DNA ploidy determined from fresh and embedded material, respectively; there was also a close correlation between the fractions of S-phase cells estimated from fresh and embedded turnours. It was also possible to cut out small histologically defined lesions, such as carcinoma in situ of the breast from thick parafin sections and obtain DNA histograms with high resolution. 相似文献
36.
37.
Buervenich S Carmine A Galter D Shahabi HN Johnels B Holmberg B Ahlberg J Nissbrandt H Eerola J Hellström O Tienari PJ Matsuura T Ashizawa T Wüllner U Klockgether T Zimprich A Gasser T Hanson M Waseem S Singleton A McMahon FJ Anvret M Sydow O Olson L 《Archives of neurology》2005,62(1):74-78
BACKGROUND: Alcohol dehydrogenases (ADHs) may be involved in the pathogenesis of neurodegenerative disorders because of their multiple roles in detoxification pathways and retinoic acid synthesis. In a previous study, significant association of an ADH class IV allele with Parkinson disease (PD) was found in a Swedish sample. PATIENTS: The previously associated single-nucleotide polymorphism plus 12 further polymorphisms in the ADH cluster on human chromosome 4q23 were screened for association in an extension of the original sample that now included 123 Swedish PD patients and 127 geographically matched control subjects. A rare nonsense single-nucleotide polymorphism in ADH1C (G78stop, rs283413) was identified in 3 of these patients but in no controls. To obtain sufficient power to detect a possible association of this rare variant with disease, we screened a large international sample of 1076 PD patients of European ancestry and 940 matched controls. RESULTS: The previously identified association with an ADH class IV allele remained significant (P<.02) in the extended Swedish study. Furthermore, in the international collaboration, the G78stop mutation in ADH1C was found in 22 (2.0%) of the PD patients but only in 6 controls (0.6%). This association was statistically significant (chi(2)(1) = 7.5; 2-sided P = .007; odds ratio, 3.25 [95% confidence interval, 1.31-8.05]). In addition, the G78stop mutation was identified in 4 (10.0%) of 40 Caucasian index cases with PD with mainly hereditary forms of the disorder. CONCLUSION: Findings presented herein provide further evidence for mutations in genes encoding ADHs as genetic risk factors for PD. 相似文献
38.
Stress and coping in a week-long disabled submarine exercise 总被引:1,自引:0,他引:1
BACKGROUND: Emotional stress could impair cognitive performance and decision-making in the initial period within a disabled submarine (SUBSUNK). The aim of the present study was to explore stress reactions over time in submarine crewmembers exposed to a simulated SUBSUNK trial. METHODS: There were 18 Norwegian sailors who were confined within the front section of a conventional diesel-electric submarine for 6 d 18 h complying with emergency SUBSUNK procedures. Self-reported measures of habitual coping and personality hardiness were completed before the simulation, and measures of emotional stress symptoms and quality of life were assessed daily during the exercise and at 2 wk after the exercise. RESULTS: A repeated measures analysis of variance showed that emotional stress symptoms declined [F (6,14) = 2.76, p < 0.05], while quality of life improved over time [F (6,14) = 4.00, p < 0.01] from the first day compared with subsequent days of the experiment. Personality hardiness was negatively associated with emotional stress (r = -0.52) and lower quality of life (r = -0.47), while avoidant coping was positively associated with lower quality of life (r = 0.53) in the first 24 h of the SUBSUNK situation (all p < 0.05). CONCLUSIONS: These findings suggest that the level of emotional stress was highest in the first 24-h period, and that the level of distress was related to scores on personality hardiness and personality traits. These data have possible implications for selection and healthcare of personnel, and also suggest that crews will benefit from external help especially in the first 24 h of emergency response techniques. 相似文献
39.
40.
Xi Z Klokk TI Korkmaz K Kurys P Elbi C Risberg B Danielsen H Loda M Saatcioglu F 《Cancer research》2004,64(7):2365-2370
Kallikreins (KLKs) are highly conserved serine proteases that play key roles in a variety of physiological and pathological processes. KLKs are secreted proteins that have extracellular substrates and function. For example, prostate-specific antigen (or KLK3) is a secreted protein that is widely used as a diagnostic marker for prostate cancer. KLK4 is a recently identified member of the kallikrein family that is regulated by androgens and is highly specific to prostate for expression. Here, we show that the gene product of KLK4, hK4, is the first member of the KLK family that is intracellularly localized. We provide strong evidence that the previously assigned first exon that was predicted to code for a signal peptide that would target hK4 for secretion is not part of the physiologically relevant form of KLK4 mRNA. In addition to detailed mapping of the KLK4 mRNA 5' end by RT-PCR, this conclusion is supported by predominantly nuclear localization of the hK4 protein in the cell, documented by both immunofluorescence and cell fractionation experiments. Furthermore, in addition to androgens, hK4 expression is regulated by estrogen and progesterone in prostate cancer cells. Finally, in situ hybridization on normal and hyperplastic prostate samples in tissue microarrays indicate that KLK4 is predominantly expressed in the basal cells of the normal prostate gland and overexpressed in prostate cancer. These data suggest that KLK4 has a unique structure and function compared with other members of the KLK family and may have a role in the biology and characterization of prostate cancer. 相似文献