| 1. |
- Asplund, Matthias, et al.
(författare)
-
Detector response from a defective wheel
- 2024
-
Ingår i: Wear. - : Elsevier. - 0043-1648 .- 1873-2577. ; 542–543
-
Tidskriftsartikel (refereegranskat)abstract
- This paper deals with field validation of the force response from a defective wheel after normal service. The defective wheel represents a typical defect arising from normal winter operation in a cold climate. The current detector is a typical wheel load impact detector that has been in use for about fifteen years; this type of detector is widely used in the infrastructure. The wheel has defects of up to1.8 mm in depth and an un-roundness of 0.2 mm. The results from this investigation, pertaining to the particular vehicle and wheel defect, show a linear correlation of speed and force response. Each change in speed of 1 km/h changes the force response by about 0.9 kN.
|
|
| 2. |
- Asplund, Matthias, et al.
(författare)
-
Field Validation of Force Response from Defective Wheel
- 2022
-
Ingår i: CM 2022 - 12th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, Conference Proceedings. - : International Conference on Contact Mechanics of Wheel / Rail Systems. ; , s. 444-448
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 3. |
- Asplund, Pär, et al.
(författare)
-
One hundred eleven Percutaneous Balloon Compressions for Trigeminal Neuralgia in a Cohort of 66 Patients with Multiple Sclerosis
- 2019
-
Ingår i: Operative Neurosurgery. - : Oxford University Press. - 2332-4252 .- 2332-4260. ; 17:5, s. 452-459
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Trigeminal neuralgia associated with multiple sclerosis (MS-TN) is comparatively rare and larger series of percutaneous balloon compression (PBC) in such cases are few in the literature.OBJECTIVE: To evaluate the results after PBC for MS-TN with regards to therapeutic effect, side effects, and complications.METHODS: One hundred eleven procedures with PBC performed in 66 cases of MS-TN were analyzed. Therapeutic effect was measured as postoperative time to pain recurrence without medication. All complications were compiled and the sensory function was evaluated in a subgroup of cases.RESULTS: The initial pain free rate was 67% and the median time to pain recurrence was 8 mo. Thirty-six patients were treated with PBC only, and among them, the results were worse if treated 3 to 4 times before, compared to first treatment (P = .009-.034). Patients who had several PBCs had worse results already after the first surgery (P < .001). A significant number of patients had impaired sensation to light touch directly after surgery, which was normalized at the late follow-up. Sensimetric testing showed raised thresholds for perception and pain directly after surgery (P = .004-.03), but these were also normalized at the late follow-up.CONCLUSION: PBC is a treatment that can be effective for many patients with MS-TN. Repeated previous surgeries is a risk factor for an unsatisfactory outcome. However, the patients with multiple surgeries had less satisfactory results already at the first procedure, indicating that a therapy resistant disease can be predicted after the first two PBCs. Postoperative sensory deficits were common but not lasting.
|
|
| 4. |
- Asplund, Pär, 1974-
(författare)
-
Percutaneous Balloon Compression for the Treatment of Trigeminal Neuralgia
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. Trigeminal neuralgia (TN) is a paroxysmal unilateral facial pain condition. That it is rather rare is of little comfort to those who are affected, as TN is often described as one of the worst pains known to mankind. Advanced age and multiple sclerosis (MS) are risk factors for developing TN. The first line of treatment is medical, primarily with carbamazepine. When medical treatment fails, as it does in many patients, there are several surgical options. One of the minimally invasive options, suitable for patients with comorbidity, is percutaneous balloon compression (PBC). Despite its introduction in the early 1980s, PBC is arguably the least well studied of the minimally invasive procedures for the treatment of TN.Aims. The aim of this thesis was to evaluate the efficacy of PBC, both overall and in MS-TN patients specifically. Further, it intended to identify and evaluate pre- and intraoperative parameters associated with the efficacy of PBC. It also investigated changes in sensory function after PBC, and identified side effects and complications associated with PBC. Finally, it sought to evaluate how efficacy, side effects and complications differed between PBC and another minimally invasive technique; percutaneous retrogasserian glycerol rhizotomy (PRGR).Methods. Cohorts of patients treated with PBC in Umeå and Stockholm, and with PRGR in Umeå, were followed retrospectively. Data from an existing database was combined with data from medical records, radiographs and telephone interviews.Results. After PBC, 90 % of the patients were completely pain free without medication for TN. The median time to recurrence of pain was 28 months. In patients with concurrent MS, the initial success rate was 67 % and the median time to recurrence was 8 months. In patients without MS, who had not previously been treated surgically, the initial success rate was 91 % and the median time to recurrence was 48 months. The procedure could, however, be repeated with good results. A good compression, indicated by a pear-shaped balloon as seen on intraoperative lateral radiograph, was crucial to achieve good pain relief. Postoperative hypoesthesia was present in the majority of patients, but after 3-6 months, sensibility was partly or fully normalized in most patients. Severe complications were rare, but included transient cardiac arrest, meningitis and dysesthesia. The side effects profile was favorable to that of percutaneous retrogasserian glycerol rhizotomy, in that the latter produced more cases of dysesthesia and decreased corneal sensibility. The efficacy of the two treatments were, however, not significantly different.Conclusions. PBC is an effective and relatively safe treatment option for patients with TN refractory to medical treatment. It deserves its place among the standard treatments for TN, and could be considered for those patients eligible for surgery for which open surgery is a less suitable option.
|
|
| 5. |
- Asplund, Pär, et al.
(författare)
-
Percutaneous Balloon Compression vs Percutaneous Retrogasserian Glycerol Rhizotomy for the Primary Treatment of Trigeminal Neuralgia
- 2016
-
Ingår i: Neurosurgery. - : Wolters Kluwer. - 0148-396X .- 1524-4040. ; 78:3, s. 421-428
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite >30 years of clinical use, the literature is still sparse when it comes to comparisons between percutaneous balloon compression (PBC) and percutaneous retrogasserian glycerol rhizolysis (PRGR) as treatments for trigeminal neuralgia.OBJECTIVE: To perform a retrospective cohort comparison between PBC and PRGR with regard to therapeutic effect, side effects, and complications.METHODS: Medical records and follow-up data from 124 primary PRGRs performed from 1986 to 2000 and 82 primary PBCs performed from 2000 to 2013 were reviewed. All patients had undergone clinical sensory testing and assessment of sensory thresholds. Analyses were performed to compare duration of pain relief, frequency of sensory disturbances, and side effects.RESULTS: Median duration of pain relief was 21 months after PRGR and 20 months after PBC. Both methods carried a high risk of hypesthesia/hypalgesia (P < .001) that was partly reversed with time. Decreased corneal sensibility was common after PRGR (P < .001) but not after PBC. Dysesthesia was more common after PRGR (23%) compared after PBC (4%; P < .001). Other side effects were noted but uncommon.CONCLUSION: PBC and PRGR are both effective as primary surgical treatment of trigeminal neuralgia. Both carry a risk of postoperative hypesthesia, but in this series, the side effect profile favored PBC. Furthermore, PBC is technically less challenging, whereas PRGR requires fewer resources. Between these 2 techniques, we propose PBC as the primary surgical technique for percutaneous treatment of trigeminal neuralgia on the basis of its lower incidence of dysesthesia, corneal hypesthesia, and technical failures.ABBREVIATIONS: MS, multiple sclerosisPBC, percutaneous balloon compressionPRGR, percutaneous retrogasserian glycerol rhizotomyTN, trigeminal neuralgiaThis is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work, provided it is properly cited. The work cannot be changed in any way or used commercially.
|
|
| 6. |
|
|
| 7. |
- Bergenheim, Tommy, et al.
(författare)
-
Percutaneous retrogasserian balloon compression for trigeminal neuralgia : review of critical technical details and outcomes
- 2013
-
Ingår i: World Neurosurgery. - : Elsevier BV. - 1878-8750 .- 1878-8769. ; 79:2, s. 359-368
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To describe percutaneous balloon compression (PBC) of the trigeminal rootlets as treatment for trigeminal neuralgia (TN), including history, operative techniques, outcomes, side effects, and some recent findings increasing the likelihood of a positive outcome.METHODS: PBC is indicated in patients with TN in whom microvascular decompression is considered less suitable. The procedure is simplified by the use of biplanar fluoroscopy, although it is usually carried out with C-arm fluoroscopy to facilitate the introduction of the needle and the visualization of the inflated catheter. In the right position, a clearly defined pear shape usually appears after injection of 0.5-0.7 mL of contrast material. The balloon is kept inflated for 1.5-3 minutes. It is crucial to obtain a pear shape because this probably is the most significant factor for obtaining good, long-lasting pain relief.RESULTS: An analysis of 100 consecutive PBC procedures showed an initial success rate of 90% and a median pain-free time without medication of 28 months. Subdividing these patients into primary TN (n = 77) and TN secondary to multiple sclerosis (a = 23), the median pain-free times were 33 months and 24 months (P = 0.2), indicating that the outcome may depend on the preoperative conditions.CONCLUSIONS: Complications and side effects include cardiovascular stress during the procedure, local hemorrhages in the cheek, postoperative sensory disturbance, masseter weakness, infections, and transitory diplopia after surgery. Measures to minimize side effects are proposed. With meticulous technique, PBC is a straightforward, effective, and fast procedure that compares well with other percutaneous therapies for TN.
|
|
| 8. |
- Samir, Raghad, 1968-
(författare)
-
Tissue tumor marker expression in normal cervical tissue and in cervical intraepithelial neoplasia, for women who are at high risk of human papilloma virus infection, are smokers, contraceptive users or in fertile age
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this research was to study the correlation between tissue tumor marker expression and HR-HPV infection, smoking, hormonal contraceptive use and sex steroids in women with cervical intraepithelial neoplasia or normal epithelium. The study investigated the expression of 11 tumor markers in cervical biopsies obtained from 228 women with different diagnoses ranging from normal cervical epithelium to various stages of CIN. 188 women were recruited at our colposcopy clinic (out-patient surgery, Department of Obstetrics and Gynecology, Falun Hospital) for laser cervical conization or a directed punch biopsy, either because of a vaginal smear (Pap smear) that showed cytological findings suggesting CIN, or because of repeated findings showing atypical squamous cells of undetermined significance (ASCUS). For 40 volunteers, punch biopsies were taken from the normal cervical epithelium. The time period for this study was 2005-2007.Study I : 228 women, of whom 116 were tested, 64 were positive to HR-HPV. The results showed that Ki67 tumor cell proliferation index was the only marker that independently correlated to both the presence of HR-HPV and the severity of cervical lesions.Study II: 228 women, of whom 83 were smokers (36, 9%). Smokers showed lower expression of p53, FHIT (tumor suppressor markers) and interleukin-10 .Higher expression of Cox-2 and Ki-67 (tumor proliferation markers).Study III: 195 women who were premenopausal. There was increased p53 expression (tumor suppressor) in the progestin-IUD users compared to non-users. Decreased IL-10 expression (immunological marker) was observed in both COC users and any progestin-only users.Study IV: Serum from 80 premenopausal women was available. The main finding was that the increased levels of serum progesterone and estradiol were associated with increased Cox-2 expression (proliferation marker). Serum progesterone and estradiol levels influence cellular and extracellular proteins which have been associated with neoplastic development in normal epithelium and CIN.Conclusion: The results of these studies support previous epidemiological findings on the role of smoking, contraceptive use and sex steroids as co-factors in development of CIN and that tumor marker expression varies in different grades of CIN.
|
|
| 9. |
- Ulvestad, Maria, et al.
(författare)
-
Drug metabolizing enzyme and transporter protein profiles of hepatocytes derived from human embryonic and induced pluripotent stem cells
- 2013
-
Ingår i: Biochemical Pharmacology. - : Elsevier. - 0006-2952 .- 1356-1839 .- 1873-2968. ; 86:5, s. 691-702
-
Tidskriftsartikel (refereegranskat)abstract
- Human embryonic and induced pluripotent stem cell-derived hepatocytes (hESC-Hep and hiPSC-Hep) have the potential to provide relevant human in vitro model systems for toxicity testing and drug discovery studies. In this study, the expression and function of important drug metabolizing cytochrome P450 (CYP) enzymes and transporter proteins in hESC-Hep and hiPSC-Hep were compared to cryopreserved human primary hepatocytes (hphep) and HepG2 cells. Overall, CYP activities in hESC-Hep and hiPSC-Hep were much lower than in hphep cultured for 4 h, but CYP1A and 3A activities were comparable to levels in hphep cultured for 48 h (CYP1A: 35% and 26% of 48 h hphep, respectively; CYP3A: 80% and 440% of 48 h hphep, respectively). Importantly, in hESC-Hep and hiPSC-Hep, CYP activities were stable or increasing for at least one week in culture which was in contrast to the rapid loss of CYP activities in cultured hphep between 4 and 48 h after plating. With regard to transporters, in hESC-Hep and hiPSC-Hep, pronounced NTCP activity (17% and 29% of 4 h hphep, respectively) and moderate BSEP activity (6% and 8% of 4 h hphep, respectively) were observed. Analyses of mRNA expression and immunocytochemistry supported the observed CYP and transporter activities and showed expression of additional CYPs and transporters. In conclusion, the stable expression and function of CYPs and transporters in hESC-Hep and hiPSC-Hep for at least one week opens up the possibility to reproducibly perform long term and extensive studies, e.g. chronic toxicity testing, in a stem cell-derived hepatic system. (C) 2013 Elsevier Inc. All rights reserved.
|
|
