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排序方式: 共有1322条查询结果,搜索用时 15 毫秒
1.
Marike Gabrielson Mattias Hammarström Magnus Bäcklund Jenny Bergqvist Kristina Lång Ann H Rosendahl Signe Borgquist Roxanna Hellgren Kamila Czene Per Hall 《International journal of cancer. Journal international du cancer》2023,152(11):2362-2372
Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen. 相似文献
2.
Martin Sjbeck Mattias Haglund Annette Persson Kerstin Sturesson Elisabet Englund 《Neuropathology》2003,23(4):290-295
Tissue microarrays (TMA) consist of up to 1000 cylindrical tissue cores from different donor paraffin blocks relocated into one recipient block, allowing for efficient histopathological studies by fluorescence in situ hybridization, RNA in situ hybridization or immunohistochemistry. On the background of the increasing interest of the TMA technique in cancer research and the suggestion of its application also in studies of non‐neoplastic intracranial disorders, the technique was applied to pathologic white matter in AD brains. Eight cases with AD and concomitant white matter pathology were neuropathologically diagnosed on whole brain coronal slides. The TMA technique was used to grade severity of white matter pathology and to quantify small vessels with traditional staining and immunohistochemical markers. These measurements were compared with the whole brain neuropathological assessment. The technique produced good results with preserved tissue structures as confirmed by the whole brain evaluation. Severity of white matter pathology evaluated on the TMA cores correlated negatively with small vessel quantities, and statistically significant differences in vessel quantities paralleled different grades of white matter pathology. It is concluded that the TMA technique could be further utilized in studies of dementing disorders, and may have its advantages in large, clinically well‐characterized materials (e.g. in quantitative mapping of white matter changes). 相似文献
3.
The purpose of this cross-sectional study was to evaluate bone mass in female athletes participating in an impact loading
sport (volleyball), and especially to investigate whether any changes in bone mass might be related to the type and magnitude
of weightbearing loading and muscle strength. The volleyball group consisted of 13 first division players (age 20.9 ± 3.7
years) training for about 8 hours/week, and the reference group consisted of 13 nonactive females (age 25.0 ± 2.4 years) not
participating in any kind of regular or organized sport activity. The groups were matched according to weight and height.
Areal bone mineral density (BMD) was measured in total body, head, lumbar spine, femoral neck, Ward's triangle, trochanter,
the whole femur, and humerus using dual-energy-X-ray absorptiometry. Isokinetic concentric peak torque of the quadricep and
hamstring muscles was measured using an isokinetic dynamometer. Compared with the controls, the volleyball players had a significantly
(P < 0.05–0.01) higher BMD of the total body (6.1%), lumbar spine (13.2%), femoral neck (15.8%), Ward's triangle (17.9%), trochanter
(18.8%), nondominant femur (8.2%), and humerus (dominant 9.5%, nondominant 10.0%), but not of the head and the dominant whole
femur. The dominant humerus showed significantly higher BMD than the nondominant humerus in both the volleyball and nonactive
group (P < 0.05). There was no significant difference in muscle strength of the thigh between the two groups. In the nonactive group,
muscle strength in the quadriceps, and especially hamstrings, was correlated to BMD of the adjacent bones (whole femur, hip
sites) and also to distant sites (humerus). However, in the volleyball group there were no correlations between muscle strength
and BMD of the adjacent bones, but quadricep strength correlated to BMD of the humerus. These results clearly show that young
female volleyball players have a high bone mass. The demonstrated high bone mass seems to be related to the type of loading
subjected to each BMD site. Muscle strength of the thigh seems to have little impact on BMD in female volleyball players.
Received: 18 June 1996 / Accepted: 31 October 1996 相似文献
4.
Incidence, nature, and causes of ice hockey injuries. A three-year prospective study of a Swedish elite ice hockey team 总被引:2,自引:0,他引:2
In this prospective study, we have investigated incidence of injuries of different severity, types of injury, and mechanisms of injury during ice hockey practice and games. One Swedish elite hockey team was closely observed during three seasons (1982 to 1985). There was a total number of 95 injuries and 29 facial lacerations. The majority of injuries were minor (73%) and only 8% were classified as major. Seventy-six percent of the injuries occurred during games and 24% during practice. The incidence of injury during practice was 1.4 per 1,000 player-practice hours and 78.4 per 1,000 player-game hours. In comparison with other sports, the incidence of injury during hockey practice is very low, while that during games is high. Eighty percent of the injuries were caused by trauma and 20% by overuse. The most common types of injury were contusions, strains, and sprains. Complete tear of the medial collateral ligament of the knee was the most common severe injury. Most injuries resulted from body contact, predominantly tackling (checking), and from puck or stick contact. A reduction of the number of minor and moderate injuries should be possible by stricter enforcement of the hockey rules, especially against stick violations, and more widespread use of visors. 相似文献
5.
S Gizurarson M Lorentzon T R?munddal F Waagstein L Bergfeldt E Omerovic 《Europace : European pacing, arrhythmias, and cardiac electrophysiology》2007,9(6):411-416
AIMS: Severe sustained bradycardia may cause acute and possibly chronic congestive heart failure (CHF). The aim of this study was to investigate acute and chronic effects of complete heart block (CHB) on cardiac function, morphology, and creatine (Cr) metabolism. METHODS AND RESULTS: CHB was induced in male Sprague-Dawley rats (approximately 250 g, n = 11) by means of electrocautery applied to the region of AV node and were compared with controls (n = 15). The rats were investigated at 1, 3, and 12 weeks after CHB induction with transthoracic echocardiography. Invasive haemodynamic assessment of left and right ventricular pressures was performed at 12 weeks. After the sacrifice, the hearts were freeze-clamped for analysis of myocardial Cr, and high energy phosphometabolites. The efficacy of operative procedure was 54%. The peri-operative mortality rate was 20%. Heart rate (HR) decreased by approximately 50% (P < 0.01) while stroke volume (SV) increased 2.5 times (P < 0.01) in the CHB rats. Cardiac index remained unchanged. The rats with CHB grew normally and were in no apparent distress. Filling pressures in left and right ventricles were normal. The CHB rats developed marked cardiomegaly with biventricular dilatation and eccentric left ventricular hypertrophy (P < 0.01). There was no change in the myocardial content of Cr and high energy phosphometabolites. CONCLUSION: Rats with CHB are compensating for reduction in HR with increased SV without haemodynamic and biochemical characteristics of CHF. This model may be useful to study the effects of CHB and bradycardia on myocardial structure, function, electrophysiology, and metabolism as well as for studies of cell therapy for reparation of AV conductance. 相似文献
6.
Lisbeth Brax Olofsson Olle Svensson Ronny Lorentzon Inger Lindström Håkan Alfredson 《Knee surgery, sports traumatology, arthroscopy》2007,15(5):560-563
Autologous periosteal transplantation (without chondrocyte cell transplantation) for treating traumatic articular cartilage
defects of the patella gives pain relief in uncontrolled clinical studies. To study the whole transplanted area macroscopically
and microscopically, animal studies are motivated. In this pilot study, we reproduce the surgical technique for periosteum
transplantation on human patella to a rabbit model. A full-thickness cartilage defect of the whole patella was created in
eight adult female rabbits. The defect was treated with autologous periosteal transplantation. After surgery, the rabbits
were allowed free activity. This is the difference compared to the treatment in humans, where our group uses CPM for 5 days
and non-weight-bearing for 12 weeks. After 21 weeks, there was a diffuse synovitis in all transplanted knees, and in five
of eight knees there were signs of osteoarthritis in the patello-femoral joint. Histologically, in three animals, small islands
of hyaline cartilage surrounded by fibrocartilage were seen in the transplanted area. In the other five animals, fibrocartilage
was the predominant tissue. In contrast to previous experimental studies using a rabbit model, we did not achieve hyaline
cartilage resurfacing. 相似文献
7.
The effects of brisk walking on markers of bone and calcium metabolism in postmenopausal women 总被引:5,自引:0,他引:5
Weight-bearing exercise has been shown to maintain or increase bone mass in younger as well as older individuals but the mechanisms
by which mechanical loading affects bone metabolism are not known in detail. Twelve postmenopausal women participated in a
single bout of brisk walking (50% of VO2 max) for 90 minuttes. Calciotropic hormones and markers of type I collagen formation (PICP) and degradation (ICTP) were measured
before the exercise, and 1, 24, and 72 hours following the exercise. Total body bone mineral content (BMC) and density (BMD)
were measured by dual energy X-ray absorptiometry (DXA). Brisk walking did not induce any significant changes in the concentrations
of ionized calcium, parathyroid hormone (PTH), calcitonin, or osteocalcin. A significant increase of PICP was noted 24 and
72 hours (P<0.01) after exertion and a significant decrease in the concentration of serum ICTP at 1 hour (P<0.05) was followed by an increase at 72 hours (P<0.001). There was no significant difference between the increases in the concentrations of PICP and ICTP at 72 hours. Strong
inverse correlations between the basal levels of PTH and BMD (r=−0.78;P<0.01) as well as between osteocalcin and BMD (r=−0.83;P<0.01) were noticed. The changes in serum levels of bone collagen markers indicate an altered bone collagen turnover due to
this moderate endurance exercise. The results also support the fact that serum levels of PTH as well as those of osteocalcin
are associated with total body BMD in postmenopausal women. 相似文献
8.
Höglund M Gisselsson D Soller M Hansen GB Elfving P Mitelman F 《Cancer Genetics and Cytogenetics》2004,154(1):1-9
Molecular cytogenetic analysis frequently shows human papillomavirus (HPV) integration near translocation breakpoints in cervical cancer cells. We have recently described a cluster of HPV18 integrations in the distal end of the common fragile site FRA8C at 8q24 in primary cervical carcinoma samples. Chromosome band 8q24 contains the MYC gene (alias c-MYC), FRA8C, and FRA8D. The MYC gene is frequently deregulated--usually by translocation or amplification--in various tumor types. In the present study, we performed a molecular cytogenetic analysis of HPV18 integration patterns and the 8q24 translocation in a primary cervical carcinoma and in HeLa cells using combined binary ratio-fluorescence in situ hybridization. Our aim was to determine how the chromosomal breaks involved in these events relate physically to the MYC gene; whether they map to the FRA8C site, the FRA8D site, or both; and how they correlate with the occurrence of DNA flexibility domains. The 8q24 translocation breakpoints mapped between stretches of integrated HPV18 sequences in the distal end of FRA8C. This region contained DNA helix flexibility clusters, several of which mapped in the vicinity of HPV integration sites and translocation breakpoints in cervical carcinomas. DNA helix flexibility clusters were also found near known MYC translocation breakpoints in Burkitt lymphomas (BL), but most BL breakpoints mapped clearly outside FRA8C. Our data revealed that FRA8C is involved in HPV integration and chromosomal translocations in cervical carcinoma; however, this fragile site is not involved in classical MYC translocations in most BLs. In the context of the familial nature of cervical cancer, FRA8C may be considered a candidate susceptibility region for cervical carcinoma. 相似文献
9.
Does a torn anterior cruciate ligament lead to change in the central nervous drive of the knee extensors? 总被引:2,自引:0,他引:2
Lars -Gunnar Elmqvist Ronny Lorentzon Christer Johansson Axel R. Fugl-Meyer 《European journal of applied physiology》1988,58(1-2):203-207
Summary Integrated surface electromyograms of the three superficial parts of the quadriceps and isokinetic knee extensor maximum torque and power production were recorded simultaneously and at different angular velocities in both legs in 11 male subjects with unilateral tear of the anterior cruciate ligament. The cross-sectional area (CSA) of the thigh and its muscular components were measured by computerized tomography. The principal findings were a small but significant decrease in quadriceps CSA on the affected side; a decreased active, but not passive, range of movement; decreased mechanical output, whether or not corrected for differences in CSA; and decreased electrornyographic activity — particularly in rectus femoris. These findings suggest that the reason for the decreased maximum and total knee extensor performance seen in these patients is a change in knee joint receptor afferent inflow. 相似文献
10.