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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Gene expression profiles and clinical parameters for survival prediction in stage II and III colorectal cancer

Begum, Mubeena 01 June 2006 (has links)
Prediction of outcome in colorectal cancer (CRC) is currently based on the TNM staging classification; however, histopathological classification alone is insufficient for accurately predicting survival in stage II and III patients. Studies indicate that microarray gene expression profiles can predict survival in CRC. We hypothesize that tumor gene expression in combination with clinical parameters, is a better predictor of outcome in stage II and III colorectal cancers than the TNM stage classification alone. Clinical records and follow-up data were retrospectively reviewed for 58 Stage II and Stage III patients with primary colorectal cancer, who did not receive any neoadjuvant therapy preoperatively and whose samples had been previously analyzed for gene expression profiles using the Affymetrix U 133a Gene chip. For molecular classification of patients as being at high or low risk for poor survival, samples were divided into two clusters by hierarchical cluster analysis of genes selected by SAM. Univariate and multivariate analyses using Cox proportional hazard models were done to identify significant prognostic factors. The 3-year and 5-year survival estimates were 72.41% (SE=5.8%) and 55.17% (SE=6.7%), respectively, for all 58 patients. Univariate analysis showed that advanced stage, older age, high-risk molecular classification, positive lymph nodes were the statistically significant prognostic factors of poor survival (p<0.05), while gender, preoperative CEA level, and family history of CRC in first degree relatives were not statistically significant. In multivariate analysis molecular classification, age and body mass index were independent significant prognostic factors. In Cox proportional hazard model, the estimated hazard ratios for Stage III vs II was 2.45 (95%CI: 0.85-7.04), for high vs low molecular risk was 3.83 (95%CI: 1.22-12.06) and old vs young age was 3.72 (95%CI: 1.2-11.49). Model containing clinical stage in conjunction with molecular risk, body mass index, and age was a stronger indicator of clinical outcome (p= 0.0056) than model with clinical stage alone. Gene expression profiles predict survival independent of clinical parameters, and the addition of gene expression profiles to stage is more predictive of survival than stage alone. Further analysis needs to be done to validate the molecular classification on an independent dataset.
102

Veiksnių, turinčių įtakos sergančiųjų galvos smegenų insultu reabilitacijos efektyvumui, įvertinimas ir jų prognozinės vertės nustatymas antruoju reabilitacijos etapu / Evaluation of factors influencing effectiveness of second stage rehabilitation and their predictive value in stroke patients

Milinavičienė, Eglė 22 October 2008 (has links)
Galvos smegenų insultas dėl aukštų mirtingumo ir ilgalaikio neįgalumo rodiklių išlieka viena didžiausių visuomenės sveikatos problemų daugelyje pasaulio šalių, tarp jų ir Lietuvoje. Didelei daliai sergančiųjų galvos smegenų insultu išlieka judėjimo, apsitarnavimo, pažinimo funkcijų sutrikimų, kurie blogina jų gyvenimo pilnatvę. Ligonių, ištiktų galvos smegenų insulto, funkcinės būklės atsigavimas yra skirtingas, todėl labai svarbu nustatyti veiksnius, kurie gali turėti įtakos reabilitacijos efektyvumui. Darbo tikslas: įvertinti veiksnius, turinčius įtakos ligonių, patyrusių galvos smegenų insultą, reabilitacijos efektyvumui antrajame reabilitacijos etape ir nustatyti jų prognozinę vertę. Darbo uždaviniai: 1. Įvertinti galvos smegenų insultą patyrusių asmenų klinikinę ir bendrą funkcinę būklę bei susijusių su motorika ir pažinimo funkcijomis gebėjimų sutrikimus ir jų kitimą antrajame reabilitacijos etape. 2. Įvertinti kompleksinės reabilitacijos efektyvumą antrajame reabilitacijos etape priklausomai nuo ligonių amžiaus, lyties, insulto pobūdžio, galvos smegenų pažeidimo lokalizacijos ir insulto sunkumo. 3. Nustatyti veiksnius, turinčius įtakos reabilitacijos efektyvumui ir jų prognozinę vertę. Mūsų atliktas tyrimas parodė, kad vyresnis amžius, kairiojo galvos smegenų pusrutulio pažeidimas ir sunkesnė neurologinė būklė antrojo reabilitacijos etapo pradžioje turi reikšmingos įtakos funkcinės būklės sunkumui antrojo reabilitacijos etapo pabaigoje. Įrodyta, kad sunkūs motorikos... [toliau žr. visą tekstą] / Stroke is one of the most relevant public health issues due to high mortality and long-lasting disability rates around the world and in Lithuania. As a consequence, stroke patients stay with such functional disorders as motoric, self-care, and cognitive dysfunctions, that impair their life satisfaction. Complex rehabilitation improves functional status in stroke patients. However, the recovery of functional status in stroke patients is different even if stroke diagnosis is the same. Aim of the study: to establish factors, influencing the effectiveness of second stage rehabilitation, and to evaluate their predictive value in stroke patients. Goals of the study: 1. to evaluate clinical and functional status, motoric and cognitive dysfunctions and its dynamics during second stage rehabilitation in stroke patients; 2. to establish the effectiveness of complex second stage rehabilitation depending on patients' age, gender, type of stroke, damage localization, and severity of stroke; 3. to establish the factors, influencing the effectiveness of rehabilitation and to evaluate their predictive value in stroke patients. Our study demonstrated, that older age, damage in left brain hemisphere, and severity of neurologic condition as measured at baseline all are related with subsequent functional status at the end of second stage rehabilitation. The study investigated, that low rehabilitation effectiveness during second stage rehabilitation on general functional status is predicted... [to full text]
103

Kombinuoto gydymo būdų ir kitų prognozinių veiksnių įtaka išplitusiu kiaušidžių vėžiu sergančių ligonių išgyvenamumui / The influence of combined treatment methods and other prognostic factors to survival of the advanced ovarian cancer patients

Simavičius, Andrius 06 January 2006 (has links)
1. INTRODUCTION Ovarian cancer is now the most common gynaecological cancer and the fourth the most common cancer among women in Lithuania. Referring to the epidemiological research ovarian cancer has the tendency to become more common: in 1990 there were 345 new cases of ovarian cancer and in 2004 - already 406 new cases. In 2004 ovarian cancer morbidity was 22.2/100 000 of inhabitants in Lithuania. Ovarian cancer is in the fifth position in the structure of death to cancer.Since there are no specific early symptoms and effective diagnostics of ovarian cancer so even 70 percent of diagnosed cases were stages III or IV. After the cytoreduction surgery and adjuvant chemotherapy with cysplatin / cyclophosphamide (CP) the survival among stage III cases was 10-20 percent and among stage IV cases not even 10 percent. In the structure of death to cancer ovarian cancer is in the sixth position - 16.1/100 000 of women. Since there is no effective prevention so the only way to prolong survival of patients is to optimise the treatment. It has been set that the optimal cytoreduction surgery could be performed only for about 50 percent of patients with stages III or IV ovarian cancer. As an alternative to conventional surgery for this group of patients the neoadjuvant chemotherapy - medical cytoreduction was applied. It could lead to the optimal conditions for cytoreduction surgery and further to prolongation of the survival. Referring to the literature the influence of neoadjuvant... [to full text]
104

Advanced Analytical Model for the Prognostic of Industrial Systems Subject to Fatigue

Abou Jaoudé, Abdo 07 December 2012 (has links) (PDF)
This thesis is dedicated to the prognostic evaluation of dynamic systems. The work presented here aims at developing an advanced tool to treat the prognostic evaluation in linear and nonlinear deterministic context in a first part as well as in the stochastic context in a second part. Our purpose is to prepare a general prognostic tool that can be capable of well predicting the RUL of a system based on an analytical damage accumulation law in either a deterministic or a stochastic context.
105

Hipofizės adenomų chirurginio gydymo rezultatus įtakojantys veiksniai / Factors influencing an effect on the results of surgery for pituitary adenomas

Šinkūnas, Kęstutis 07 October 2008 (has links)
Hipofizės adenoma yra biologiškai gerybinis navikas, augantis iš priekinės hipofizės dalies – adenohipofizės ląstelių, galinčių produkuoti įvairius hipofizės hormonus. Jos paplitimas yra 20 atvejų 100000 gyventojų, kasmet nustatomi 1,5 – 2 atvejai 100000 gyventojų. Pagrindiniu priėjimu prie hipofizės šiuo metu tapo transsfenoidinis priėjimas, transkranijinį naudojant tik labai retais atvejais. Nors hipofizės adenomos diagnostikos ir gydymo galimybės tobulėja, vis dar išlieka nemaža neišspręstų problemų. Šio darbo tikslas buvo nustatyti veiksnius, turinčius reikšmės hipofizės adenomų chirurginio gydymo rezultatams. Darbo uždaviniai: 1. Įvertinti intraoperacinių ir pooperacinių komplikacijų dažnį naudojant skirtingus priėjimo prie turkiabalnio metodus. 2. Nustatyti intraoperacinį smegenų skysčio tekėjimą įtakojančius veiksnius. 3. Įvertinti naujo daugiasluoksnio turkiabalnio uždarymo metodo efektyvumą, palyginti su anksčiau naudotais metodais, esant intraoperaciniam smegenų skysčio tekėjimui. 4. Išnagrinėti prolaktinomų chirurginio gydymo baigtį lemiančius veiksnius. 5. Nustatyti veiksnius, leidžiančius prognozuoti gerą somatotropinį hormoną sekretuojančių adenomų chirurginio gydymo baigtį. 6. Įvertinti regos atsistatymo po transsfenoidinio hipofizės adenomos pašalinimo rezultatus ir nustatyti prognozinius veiksnius, leidžiančius tikėtis regos atsistatymo po operacijos. 7. Įvertinti Farnsword – Munsell spalvų skyrimo ir spalvų juslės slenksčio kompiuterinio testo jautrumą ir... [toliau žr. visą tekstą] / Pituitary adenoma is a biologically benign tumour growing from the anterior part of pituitary gland - adenopituitary cells that can produce different hormones. Its incidence rate is 20 cases per 100 000 population and each year 1.5 - 2 cases per 100 000 population are diagnosed. Transsphenoidal approach has become the major approach to the pituitary gland, with transcranial approach being applied in extremely rare cases. Although the possibilities of pituitary adenoma diagnosis and treatment have been improving, a number of problems remain unsolved. Aim of the study - to identify the factors that have an effect on the results of surgery for pituitary adenomas. Objectives: 1. To assess the incidence of intraoperative and postoperative complications by using different approach to sella turcica. 2. To identify the factors that have an effect on intraoperative cerebrospinal fluid leak. 3. To assess the efficiency of the new multi-layer sella turcica closure technique as compared to the previously used techniques in the presence of intraoperative cerebrospinal fluid flow. 4. To analyse the factors determining the outcome of surgery for prolactinomas. 5. To identify the factors enabling to prognosticate a favourable outcome of surgery for adenomas secreting the somatotropic hormone. 6. To assess the vision recovery results after transsphenoidal removal of pituitary adenoma and to establish prognostic criteria enabling to expect vision recovery after surgery. 7. To assess the... [to full text]
106

Medical and social conditions in the elderly gender and age differences : the Umeå longitudinal study

Österlind, Per Olov January 1993 (has links)
In 1981, no representative study of the medical and social conditions among elderly persons in northern Scandinavia was performed. Nor was there such a study in a smaller Swedish town than Gothenburg. This study was initiated to fill that knowledge gap. The aim of the study was to evaluate gender and age differences in medical and social conditions among elderly people, including the reference intervals of clinical chemistry parameters and characteristic features of the 24-hour electrocardiogram (ECG) in healthy elderly. By way of longitudinal design with birth cohorts stratified by gender, it was assumed that the effects could be demonstrated. Also, the death risk of various social and medical variables was to be assessed. During the study period 1981 to 1990, the subjects were between 70 and 88 years of age. The proportion of persons living in private housing decreased from almost all at the age of 70 to slightly more than half at 88 years of age. The number of socially active persons decreased considerably during the period. The need of help increased from almost none to 60 % of the persons. The proportions of persons with normal sight and hearing decreased from two thirds to around one tenth The most frequent symptoms were general tiredness, pains, dyspnoea, constipation and dryness of the mouth. Cardiovascular diseases were the most frequent. Hypertensive disease became less, and congestive heart failure more frequent with age. The frequency of dementia increased steeply among the oldest persons; at 88 years of age, 40 % were demented. Drug consumption increased; the oldest persons in both age cohorts used 5 different drugs or more per person regularly. The consumption increase was mainly due to the increasing morbidity accompanying age. The most common drugs taken were cardiovascular preparations, psychoactive agents, drugs to alleviate gastrointestinal symptoms, and analgesics. Drug intake and symptom prevalence were generally higher in women, despite the fact that there was no gender difference in the number of diseases. The reference intervals of many blood components in healthy elderly were shown to be broader than those of younger persons. The intervals of P(lasma)-folate and P- potassium were on a lower and those of the erythrocyte sedimentation rate, P-creati- nine and, in women, S(erum)-cholesterol, were on a higher level than among younger persons. Several features of the 24-hour ECG, e.g. the number of episodes of supraventricular tachycardia as well as supraventricular and ventricular premature beats in healthy elderly were more frequent than among younger persons. Between 80 and 88 years of age, many functions crucial to the chances of living a rich and vital life were found deteriorating in the elderly persons. High age, male sex, dementia, congestive heart failure, and low values of S-creatinine were shown to be independent factors connected with an increased death risk. / <p>S. 1-112: sammanfattning, s. 115-177: 5 uppsatser</p> / digitalisering@umu.se
107

Thyroid cancer : studies on etiology and prognosis

Hallquist, Arne January 1994 (has links)
Thyroid cancer constitutes about 1% of all malignant tumours and the incidence is increasing in Sweden. It is rare in children before the age of 10. During puberty the female to male ratio increases to be two to three times more common in females. The ratio remains constant until menopause and thereafter declines. The etiology of this gender-dependent incidence difference is unclear. Ionizing radiation is the only well-established risk factor for the disease, while the impact of other etiological factors is not clear. A retrospective study based upon medical records of 218 females and 91 males with papillary, mixed or follicular types of thyroid cancer was conducted. Prognostic factors were compared by multivariate analysis using Cox's semiparametric hazard model. Differences in prognosis between women and men were found. There was a higher relapse rate and mortality risk among men. Distant metastasis, age &gt;50 years, regional lymph node metastasis, low or moderate differentiation, and tumour related symptoms at diagnosis were also independent factors related to increased tumour mortality risk. A population-based case-control study including 180 cases and 360 controls was carried out to identify risk factors for thyroid cancer. Information on exposure was obtained by mailed questionnaires. The first part of the study investigated connections between medical ionizing radiation and thyroid cancer. The results showed that diagnostic X rays were a significant risk factor for papillary thyroid cancer in women between 20 and 50 years at diagnosis. Exposure to iodine-131 caused no increased risk for thyroid cancer. The result supports that external radiotherapy is a risk factor for thyroid cancer in women. The second part of the case-control study dealt with occupation and different exposures. Work with diagnostic X-ray investigations and work as a lineman was associated with thyroid cancer. Exposure to impregnating agents increased the risk. The third part of this study showed that one pregnancy increased the risk for papillary thyroid cancer. A medical history of asthma or allergy decreased the risk. Another case-control study using medical records as the source for assessment of exposure gave a non significantly increased risk for thyroid cancer in patients who had been treated with external radiotherapy including the thyroid gland. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 5 uppsatser.</p> / digitalisering@umu
108

Whiplash associated disorders : acute and chronic consequences with some implications for rehabilitation

Sterner, Ylva January 2001 (has links)
Background: Whiplash associated disorders (WAD) account for a large proportion of the overall impairment and disability from traffic injuries and causes substantial bio psychosocial consequences for some individuals. Aims: To increase the knowledge about factors described in terms of either function /impairment, activity/disability and life satisfaction in acute and chronic WAD as well as possible implications for rehabilitation. Within this aim the incidence and recovery rate of whiplash injury and prognostic factors of interest for early rehabilitation have been studied. Subjects and Methods: Fifty-five healthy controls and 34 WAD subjects were analysed within and between groups concerning a) biomechanical out put, endurance, fatigue and muscle tension (EMG activity of trapezius, infraspinatus and deltoideus) during repetitive shoulder forward flexion b) impairments and activity/disability and life satisfaction.356 subjects seeking medical attention due to whiplash trauma, 296 were available at follow up, mean 16 months post injury. Incidence and odds ratio of accident and other background factors on disability were determined. Thirty-four out of 43 patients with whiplash injury were investigated through quantitative sensory tests at six weeks and 71 months after injury. 62 WAD participated in an interdisciplinary rehabilitation program (a pilot study) designed to evaluate such rehabilitation program for patients with chronic (in relatively early stage) WAD. Program evaluation of impairment, disability and life satisfaction (prospective and retrospective) was carried out before and after program and at 6 months. Results: No significant effects of sex or age on the ability to relax between repetitive r muscle contractions (SAR) were found in healthy subjects (study I). Significantly higher inability to relax between contractions was found for the two portions of trapezius and infraspinatus in the WAD group compared to the healthy group (study II). Significantly lower levels of activity preferences were noted for three out of five indices in females with WAD The WAD group had significantly higher prevalence of neropsychological and emotional symptoms. Both pain related symptoms and neropsychological symptoms were of significant importance for aspects of disability and life satisfaction in this group (study IV). Sensory disturbances over the trigeminal skin area persisted over the years. At follow-up a significant correlation was found between the sensory disturbances and the symptoms related to the central nervous system while no significant relationship was found with the musculoskeletal symptoms (study HI) .The annual incidence according to the grading of the Quebec Task Force on Whiplash-Associated Disorders (WAD 1-3) was 3.2/1000 and 4.2/1000 when WAD 0 was included. Sixty-eight percent of the patients recovered during the follow-up Pre-traumatic neck pain, low educational level, female gender and WAD grade E-Ill were significantly associated with a poor prognosis (study IV). . Participants in the rehabilitation program reported increased coping ability. Stress reactions seemed rather frequent (32 %). Pain intensity in the neck and upper back were significantly decreased at 6 months follow-up. However, for most of the functional and psychological markers, no significant changes were found (study V). Conclusion: The higher prevalence of musculoskeletal complaints of the neck shoulder region in females cannot be explained by higher muscle tension and clinical assumption of increased muscle tension seems correct in whiplash patients Results indicate heterogeneity among WAD subjects. Females are at risk after a whiplash trauma but the severity of initial symptoms and signs also affect outcome as well as low education. High levels of neuropsychological symptoms and pain, signs of posttraumatic stress, fear and avoidance, loss of control, anxiety, bio-mechanical and psychosocial factors at work (studies) and social support are potential factors to be aware of. Extensive and costly investigations are in most cases not necessary. However most persons will recover a whiplash injury. Multidisciplinary/interdisciplinary assessment should be considered at three months if substantial negative effect on the person’s ability to function and health situation exists. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 2001, härtill 6 uppsatser.</p> / digitalisering@umu
109

The Prognostic Impact of Proliferation Markers in Breast Cancer with Emphasis on Cyclin B1 and PPH3

Koliadi, Anthoula January 2014 (has links)
The aim of this thesis was to investigate the prognostic role of the proliferation markers cyclin B1 and Phosphorylated Histone 3 (PPH3) in breast cancer (BC). In paper I we used an experimental study design, we compared women dying early from their BC with women free from relapse more than eight years after initial diagnosis. All women had stage I, node-negative and hormone receptor positive disease. None had received adjuvant chemotherapy. We found that low-risk node negative patients with high expression of cyclin B1 had a significantly worse outcome than patients with low expression of cyclin B1. In paper II a population-based case control study was performed to further investigate the prognostic value of cyclin B1. One hundred and ninety women who died from BC were defined as cases and 190 women alive at the time for the corresponding case’s death were defined as controls. Inclusion criteria were tumor size 50 mm, no lymph node metastases, and no adjuvant chemotherapy. Two investigators evaluated the stainings independently. Cyclin B1 was found to be a prognostic factor for BC death that could identify high-risk patients with a good to very good reproducibility. Paper III aimed to investigate the role of proliferation in male breast cancer (MBC). One hundred and ninety-seven MBC tumors were stained for cyclin A, B1, D1 and Ki67. Overexpression of cyclin A and B1 and elevated mitotic count were predictive of breast cancer death. Ki67 was re-evaluated and different cut-offs were used, but no prognostic value could be demonstrated. On the other hand high levels of cyclin D1 were associated with better outcome in MBC. In paper IV we applied the immunohistochemichal panel suggested from international guidelines to the same patient material as in paper II, to discriminate luminal A from luminal B BC. We wanted to evaluate if different cut-off values of Ki67, cyclin A or B1 could more clearly separate luminal A from B. Cyclin A, B1 and Ki67 (cut-off 20%) could detect difference in outcome between these subtypes with cyclin A showing greater prognostic value. The aim of paper V was to examine the prognostic role of PPH3 compared to the proliferation markers Ki67, cyclin A and cyclin B1 with focus on ER positive disease. PPH3 was found to be a prognostic factor for breast cancer death but in the multivariate analysis including all proliferation markers, only cyclin A remained a prognostic factor. Finally, we conclude that both cyclin B1 and PPH3 are prognostic factors for breast cancer death, but are outperformed by cyclin A in ER positive patients. In male breast cancer prognostic factors need to be further studied.
110

Stochastic modeling and prognostic analysis of complex systems using condition-based real-time sensor signals

Bian, Linkan 14 March 2013 (has links)
This dissertation presents a stochastic framework for modeling the degradation processes of components in complex engineering systems using sensor based signals. Chapters 1 and 2 discuses the challenges and the existing literature in monitoring and predicting the performance of complex engineering systems. Chapter 3 presents the degradation model with the absorbing failure threshold for a single unit and the RLD estimation using the first-passage-time approach. Subsequently, we develop the estimate of the RLD using the first-passage-time approach for two cases: information prior distributions and non-informative prior distributions. A case study is presented using real-world data from rolling elements bearing applications. Chapter 4 presents a stochastic methodology for modeling degradation signals from components functioning under dynamically evolving environmental conditions. We utilize in-situ sensor signals related to the degradation process, as well as the environmental conditions, to predict and continuously update, in real-time, the distribution of a component’s residual lifetime. Two distinct models are presented. The first considers future environmental profiles that evolve in a deterministic manner while the second assumes the environment evolves as a continuous-time Markov chain. Chapters 5 and 6 generalize the failure-dependent models and develop a general model that examines the interactions among the degradation processes of interconnected components/subsystems. In particular, we model how the degradation level of one component affects the degradation rates of other components in the system. Hereafter, we refer to this type of component-to-component interaction caused by their stochastic dependence as degradation-rate-interaction (DRI). Chapter 5 focuses on the scenario in which these changes occur in a discrete manner, whereas, Chapter 6 focuses on the scenario, in which DRIs occur in a continuous manner. We demonstrate that incorporating the effects of component interactions significantly improves the prediction accuracy of RLDs. Finally, we outline the conclusion remarks and a future work plan in Chapter 7.

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