| 61. |
- Aljabery, Firas
(författare)
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Staging and tumor biological mechanisms of lymph node metastasis in invasive urinary bladder cancer
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aim: To study the possibility of detecting lymph node metastasis in locally advanced urinary bladder cancer (UBC) treated with radical cystectomy (RC) by using preoperative positron emission tomography/computed tomography (PET/CT) and peroperative sentinel node biopsy (SNB) technique. We also investigate the clinical significance of macrophage traits expression by cancer cells, M2-macrophage infiltration (MI) in tumor stroma and the immunohistochemical expression of biomarkers in cancer cells in relation to clinicopathologic data.Patients and Methods: We studied prospectively 122 patients with UBC, pathological stage pT1–pT4 treated with RC and pelvic lymph node dissection (PLND) during 2005–2011 at the Department of Urology, Linköping University Hospital. In the first study, we compared the results of preoperative PET/CT and conventional CT with the findings of postoperative histopathological evaluation of lymph nodes (LNs). In the second study we investigated the value of SNB technique for detecting pathological LNs during RC in patients with UBC. W also examined the significance of the primary tumor location in the bladder in predicting the site of LN metastases, and the prognostic significance of lympho-vascular invasion (LVI) and lymph node metastasis density (LNMD) on survival. In the third study, we investigate the clinical significance of macrophage infiltration (MI) in tumor stroma and macrophage-traits expression by tumor cells. In the fourth study, we investigate the cell cycle suppression proteins p53, p21, pRb, p16, p14 ARF as well as tumors proliferative protein Ki67 and DNA repair protein ERCC1 expression in cancer cells. The results were compared with clinical and pathological characteristics and outcome.Results: Prior to RC, PET/CT was used to detect LN metastasis in 54 patients. PET/CT had 41% sensitivity, 86% specificity, 58% PPV, and 76% NPV, whereas the corresponding figures for conventional CT were 41%, 89%, 64%, and 77%. SNB was performed during RC in 103 patients. A median number of 29 (range 7–68) nodes per patient were examined. SNs were detected in 83 out of 103 patients (81%). The sensitivity and specificity for detecting metastatic disease by SNB varied among LN stations, with average values of 67% -90%. LNMD or ≥8% and LVI were significantly related to shorter survival. In 103 patients, MI was high in 33% of cases, while moderate and low infiltration occurred in 42% and 25% of tumors respectively. Patients with tumors containing high and moderate compared to low MI had low rate of LN metastases (P=0.06) and improved survival (P=0.06), although not at significant level. The expression of different tumor suppression proteins was altered in 47-91% of the patients. There were no significant association between cancer specific survival (CSS) and any of the studied biomarkers. In case of altered p14ARF, ERCC1 or p21, CSS was low in case of low p53 immunostaining but increased in case of p53 accumulation, although not at a significant level, indicating a possible protective effect of p53 accumulation in these cases.Conclusion: PET/ CT provided no improvement over conventional CT in detection and localization of regional LN metastases in bladder cancer. It is possible to detect the SN but the technique is not a reliable for perioperative localization of LN metastases; however, LVI and LNMD at a cut-off level of 8% had significant prognostic values. MI in the tumor microenvironment but not CD163 expression in tumor cells seems to be synergistic with the immune response against urinary bladder cancer. Our results further indicate that altered p53 might have protective effect on survival in case of altered p14ARF, p21, or ERCC1 indicating an interaction between these biomarkers.
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| 62. |
- Alkaissi, Aidah, 1953-
(författare)
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Postoperative Symptoms After Gynaecological Surgery : How They Are Influenced by Prophylactic Antiemetics Sensory Stimulation (P6-Acupressure)
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Symptoms after surgery and anaesthesia influence the patient´s ability to resume daily activities. If postoperative symptoms are controlled rehabilitation may be accelerated. The aims of this dissertation were to identify disturbing symptoms reported by patients after gynaecological surgery, to investigate what effect prohylactic treatment with antiemetics has on these symptoms and whether or not sensory simulation of the P6-acupressure has an effect on postoperative nausea and vomiting (PONV) and motion sickness.Methods: Total 1138 women participated in three clinical trials (Studies I, II, III) and one experimental study (Study IV). A questionnaire investigating postoperative symptoms was constructed and validated. The questionnaire was used in a prospective, consecutive, doubleblind, randomised, multicentre, and controlled study to identify incidence, and intensity of postoperative symptoms and the effect of common antiemetics (droperidol and granisetron) (Study III). The patients were followed for 24 h. In two studies (I, II) P6-acupressure was compared (prospective, double-blind, ransomised, controlled) with placebo acupressure and a reference group where the effect on PONV was followed over 24 h. The effect of P6-acupressure and placebo acupressure on motion sickness induced by a nauseogenic motion challenge was studied (Study III).Results: A high incidence and severity of postoperative symptoms were found after gynaecological surgery in a group with a high risk (>30%) for PONV. Sixty-four per cent (107/165) of the patients experienced disturbing symptoms after surgery and 46 % (76/165) scored their symptoms as moderate to very severe. Fourty-eight per cent (79/165) had two or more symptoms. A higher incidence of symptoms were reported in the groups with prophylactic treatment, granisetron 74% (123/165) and droperidol 80% (133/165) compared to the control group 41% (69/165) (P <0.05). The relative risk reduction for PONV with granisetron or droperidol prophylaxis is 27% respective 22%. The relative risk increase for headache is 63% after granisetron, and 44% for difficulty with accommodation after droperidol. Less PONV was seen after P6-acupressure, 33% (44/135) compared to reference group 46% (63/136) (p = 0.019), number needed to treat (NNT) was 7 [95% confidence interval (CI) 4- 6]. When comparing laparoscopic and vaginal surgery (subgroup analysis) the main effect was in the vaginal group (day-case surgery), 36% (27/75) in the reference group to 27% (23/86) in the placebo group and to 20% (17/84) in the P6-acupressure group, (P = 0.017), NNT for the vaginal group was 6 [95% CI 3-18]. P6-acupressure increased time to nausea after a laboratory motion challenge and reduced the total number of symptoms reported (p <0.009).Conclusions: There is no clinical efficacy in the form of reduced postoperative symptoms after prophylactic antiemetics (droperidol and granisetron) in females with a high risk (>30%) for PONV undergoing gynaecological surgery. P6-acupressure reduces the incidence of PONV after gynaecological surgery in females with a high (>30%) risk for PONV. The effect seems to be most prominent after vaginal surgery. P6-acupressure increased tolerance to experimental nausogenic stimuli and reduced the total number of symptoms reported in females with a history of motion sickness.
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| 63. |
- Alkaissi, Hammoudi, 1983-
(författare)
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Identification of candidate genes involved in Mercury Toxicokinetics and Mercury Induced Autoimmunity
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: Autoimmune diseases require the involvement and activation of immune cells and occur when the body builds up an immune response against its own tissues. This process takes place due to the inability to distinguish self-antigen from foreign antigen. Systemic autoimmunity represents an important cause of morbidity and mortality in humans. The mechanisms triggering autoimmune responses are complex and involve a network of genetic factors. Genome wide association study (GWAS) is a powerful method, used to identify genetic risk factors in numerous diseases, such as systemic autoimmune diseases. The goal of GWAS is to identify these genetic risk factors in order to make predictions about who is at risk and investigate the biological process of disease susceptibility. There are several valuable mouse models to investigate the underlying mechanisms causing systemic autoimmune diseases in which mercury induced autoimmunity (HgIA) is a well- established and relevant model. HgIA in mice includes development of autoantibodies, immune complex glomerulonephritis, lymphocyte proliferation, hypergammaglobulinemia and polyclonal B cell activation. In humans, mercury exposure accumulates with considerable concentrations in kidney, liver, and brain. Toxicokinetics of Hg has been studied extensively but the key for inter-individual variation in humans are largely unclear. Differences in accumulation of renal Hg between inbred mouse strains suggest a genetic inter-strain variation regulating retention or/and excretion of Hg.OBJECTIVES: To find loci and candidate genes associated with phenotypes involved in the development of autoimmunity and find candidate genes involved in the regulation of renal Hg excretion.METHODS: MHC II (H-2s) mice were paired (A.SW x B10.S) to obtain F2 offspring exposed to 2.0 or 4.0 mg Hg in drinking water for 6 weeks. Mercury induced autoimmune phenotypes were studied with immunofluorescence (anti-nucleolar antibodies (ANoA)), ELISA anti-DNP/anti-ssDNA (polyclonal B cell activation), anti-chromatin antibodies (ACA) (4.0 mg Hg), and serum IgG1 concentrations. Mercury accumulation in kidney was performed previously and data was included as phenotype. F2 mice exposed to 2.0 mg Hg were genotyped with microsatellites for genome-wide scan with Ion Pair Reverse Phase High Performance Liquid Chromatography (IP RP HPLC). F2 mice exposed to 4.0 mg Hg were genotyped with single nucleotide polymorphisms for genomewide scan with SNP&SEQ technology platform. Quantitative trait loci (QTL) was established with R/QTL. Denaturing HPLC, next generation sequencing, conserved region analysis and genetic mouse strain comparison were used for haplotyping and fine mapping on QTLs associated with Hg concentration in kidney, development of ANoA and serum IgG1 hypergammaglobulinemia. Candidate genes (Pprc1, Bank1 and Nfkb1) verified by additional QTL were further investigated by real time polymerase chain reaction. Genes involved in the intracellular signaling together with candidate genes were included for gene expression analysis.RESULTS: F2 mice exposed to 2.0 mg Hg had low or no development of autoantibodies and showed no significant difference in polyclonal B cell activation in the B10.S and F2 strains. F2 mice exposed to 4.0 mg Hg developed autoantibodies and significantly increased IgG1 concentration and polyclonal B cell activation (anti-DNP). QTL analysis showed a logarithm of odds ratio (LOD) score between 2.9 – 4.36 on all serological phenotypes exposed to 4.0 mg Hg, and a LOD score of 5.78 on renal Hg concentration. Haplotyping and fine mapping associated the development of ANoA with Bank1 (B-cell scaffold protein with ankyrin repeats 1) and Nfkb1 (nuclear factor kappa B subunit 1). The serum IgG1 concentration was associated with a locus on chromosome 3, in which Rxfp4 (Relaxin Family Peptide/INSL5 Receptor 4) is a potential candidate gene. The renal Hg concentration was associated with Pprc1 (Peroxisome Proliferator-Activated Receptor Gamma, Co-activator-Related). Gene expression analysis revealed that the more susceptible A.SW strain expresses significantly higher levels of Nfkb1, Il6 and Tnf than the less susceptible B10.S strain. The A.SW strain expresses significantly lower levels of Pprc1 and cascade proteins than the B10.S strain. Development of ACA was associated with chromosomes 3, 6, 7 and 16 (LOD 3.1, 3.2, 3.4 and 6.8 respectively). Polyclonal B cell activation was associated with chromosome 2 with a LOD score of 2.9.CONCLUSIONS: By implementing a GWAS on HgIA in mice, several QTLs were discovered to be associated with the development of autoantibodies, polyclonal B cell activation and hypergammaglobulinemia. This thesis plausibly supports Bank1 and Nfkb1 as key regulators for ANoA development and HgIA seems to be initiated by B cells rather than T cells. GWAS on renal mercury excretion plausibly supports Pprc1 as key regulator and it seems that this gene has a protective role against Hg.
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| 64. |
- Alkhori, Liza
(författare)
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Mechanisms of sensory neuron diversification during development and in the adult Drosophila : How to make a difference
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The nervous system contains a vast number of neurons and displays a great diversity in cell types and classes. Even though this has been known for a long time, the exact mechanism of cell specification is still poorly understood. How does a cell know what type of neuron to which it should be specified? It is important to understand cellular specification, not only for our general understanding of biological processes, but also to allow us to develop treatments for patients with destructive diseases, such as Alzheimer’s, Parkinson, cancer or stroke. To address how neuronal specification and thereby diversification is evolved, we have chosen to study a complex but defined set of neurons, the Drosophila olfactory system. Olfactory sensory neurons (OSNs) detect an enormous variety of small volatile molecules with extremely high specificity and sensitivity. The adult Drosophila olfactory system contains 34 OSN classes each defined by their expression of a specific odorant receptor (OR). In both insects and vertebrates, each OSN expresses only one OR. In mouse there are approximately 1200 and in Drosophila 60 different OR genes. Despite the range of mechanisms known to determine cell identity and that the olfactory system is remarkably conserved across the phyla, it is still unclear how an OSN chooses to express a particular OR from a large genomic repertoire. In this thesis, the specification and diversification of the final steps establishing an OSN identity is addressed. We find seven transcription factors that are continuously required in different combinations for the expression of all ORs. The TFs can in different gene context both activate and repress OR expression, making the regulation more economical and indicating that repression is crucial for correct gene expression. We further identified a repressor complex that is able to segregate OR expression between OSN classes and propose a mechanism on how one single co-repressor can specify a large number of neuron classes.Exploring the OSN we found the developmental Hh signalling pathway is expressed in the postmitotic neuron. We show several fundamental similarities between the canonical Drosophila Hh pathway and the cilia mediated Hh transduction in component function. Further investigation revealed a function of cilia mediated Hh signalling in sensory neuron modulator. The results generated here will create a greater in vivo understanding of how postmitotic processes generate neurons with different fates and contribute to the maintaining of neuron function.
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| 65. |
- Allemann, Hanna, 1979-
(författare)
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Online support for informal carers of persons with heart failure : Focus on perceptions, development and experiences
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Heart failure (HF) is a common condition, and its prevalence is expected to increase. The illness trajectory is unpredictable, and its effects will include a potential impact on informal carers, i.e., family, friends, and significant others. Sometimes these persons are affected by the help and care they provide in such a way that they might themselves need support. However, they may be unrecognised in their endeavours, and might also experience a lack of support, especially from healthcare. Online solutions are considered to have the potential to provide accessible support to carers that is also anticipated to be cost-effective. Aim: This thesis focuses on support to informal carers to persons living with HF, but also take the viewpoint of the person with HF by exploring social supports associations with their health and well-being. The overall aim was to explore perceptions, development, and experiences of online support for informal carers. Method: This thesis comprises four studies. Study I had a cross-sectional design using self-reported data and data from the Swedish Pace-maker and ICD Registry. Data from 1,550 persons with HF who were living with an ICD and who had complete data on the outcome variable were utilised for both descriptive analysis and logistic regression. The outcome variable, perceived social support, was measured using the questionnaire Multidimensional Scale of Perceived Social Support (MSPSS), which includes measuring support from significant others, family, and friends. The logistic regression was conducted to compare those dichotomised as having low/medium perceived social support to those having high levels of support. Study II had a qualitative design, and data were collected through 8 focus groups with 23 informal carers of persons with HF to explore their perceptions of how online solutions could be of value for support. Data were analysed using qualitative content analysis. Study III had a descriptive design. It describes the co-design process of an online support pro-gramme for carers through three phases. In phase I, topics and content that reflected carers needs and preferences were identified. In phase II, the content for the support programme was developed and through phase III the content was refined and finalised. Informal carers participated in every phase, and the co-design process also involved professionals with expertise in, for example, HF and caregiving, for the development of content. It was an iterative process, moving back and forth between phases, and the re-search group acted as coordinators and ensured that carers’ voices were kept central to the process. Study IV had a qualitative design, and data were collected through individual semi-structured interviews with 15 carers. Interviews were analysed using qualitative content analysis. The study focused on informal carers' experiences of online, co-designed support pro-gramme while being participants in a randomised controlled trial (RCT) that has the aim of studying the effects of engaging with the programme. Results: The findings show that one in five diagnosed with HF and living with an ICD reported low/medium levels of social support and that these persons had higher odds of negative psychosocial outcomes. This un-derscores the value and importance of support from informal carers for the well-being of those with HF. The thesis focused on perceptions, development, and experiences of online support for informal carers. The findings suggest that a co-designed support programme has the potential to be usable and useful for carers considering the online format and its content. It may provide insights, preparedness, and validation in relation to being a carer of a person with HF. However, carers may have an ‘ambiguous stance’ towards the online format and going online for support may not be the preferred form of support for all carers. Conclusion: A co-designed online support programme, when built on a trusted platform within a healthcare context, may be considered both usable and useful for carers. The online format and content also provide the potential to offer timely and adaptable support. The content, developed in a collaboration between carers and professionals, offers evidence-based, relevant information, thereby possibly avoiding seeming impersonal, which can also be beneficial. The programme acknowledges the intertwined lives of carers and those with HF, and its content reflects this, potentially also enhancing its perception as usable and useful for carers. Still, the potential of the support programme depends on carers being aware of its existence, or being made aware, and can further recognise its value. The support programme is considered to have the capacity to be relevant for a broad group of carers, and therefore efforts may be of importance to ensure it is accessed and utilised. However, it is also important to take into account that not everyone may be willing or able to go online for support, or may wish to stay in a caring role. Healthcare also needs to recognise this when offering support to carers and the online support may be regarded an option among several.
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| 66. |
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| 67. |
- Almer, Sven, 1953-
(författare)
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Ulcerative colitis : Imaging of inflammation
- 1995
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Ulcerative colitis is a chronic inflannnatory disorder of unknown origin engaging the large bowel. Based on the need for accurate assessment of inflammation, three different non-invasive techniques, two leukocyte scintigraphy techniques and one radiological method, were evaluated in the assessment of active inflammation in altogether 131 patients with ulcerative colitis. Results were compared to those of endoscopy with biopsy, and with histopathological grading of depth of ulceration in colectomy specimens. Nine non-inflamed controls were also includedLeukoeyte scintigraphy using technetium-99m exarnetazime-labelled lenkocytes was found to reliably differ between patients with and without colonic inflammation. A good correlation existed between a simple visual scoring system of lenkocyte scans and colonic inflannnation viewed endoscopically and histologically in ulcerative colitis. In active disease, inflammation was better visualized with technetiurn-99m exametazimelabelled leukocytes than with technetium-99m anti-granulocyte antibody BW 250/183.Air enema radiology was of value in estimating severe mucosal inflammation in acute ulcerative colitis. Presence of faecal residue or a normal air enema film were associated with normal or only mildly inflamed mucosa at colonoscopy, i.e. a friable or ulcerated mucosa can be excluded. The absence of faecal residue or an abnormal finding at air enema X-ray were predictive of endoscopically inflamed mucosa. Air enema radiology underestimated the extent of inflannnation compared to endoscopy or lenkocyte scintigraphy. Air enema radiology was able to demonstrate presence of deep histopathological ulceration in the colectomy specimens from patients with an acute attack of ulcerative colitis.In conclusion, scintigraphy with technetium-99m exarnetazime-labelled lenkocytes can be applied in excluding or confirming bowel inflammation in individual patients, and, in assessing intensity and extent of ulcerative colitis. Air enema radiology should be a first-line investigation in acute colitis to assess the presence of mucosal or deeper ulceration.
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| 68. |
- Almroth, Gabriel, 1953-
(författare)
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Immunoglobulins, immunoglobulin subclass-distributions and serologic markers in some renal and systemic disorders
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this study we evaluated pathogenetic factors and possible mediators of renal and systemic disorders where immunologic mechanisms might be of importance.An abberant immunoglobulin and IgG-subclass distribution was detected in 103 patients with primary and secondary glomerulonephritis as well as in 38 patients with the systemic disease primary Sjögren 's syndrome or purpura hypergammaglobulinemica (elevated IgG1 and low IgG2 ).The drug hydralazine, an anti-hypertensive, was considered to cause renal disease on an immunologic base in 17 patients, with autoantibody production (mainly ANA and antibodies to myeloperoxidase).Dialysis-patients showed adequate antibody responses to vaccination against pneumococci but low responses against hepatitis B, while the IgG-subclass response of the hepatitis B antibody (anti-HBs) was low, but not shown to be significantly different from that of healthy adults.A therapeutical removal of igG-antibodies with immunoadsorption or plasmapheresis was considered to have a possible adjuvant effect to medical immunosuppressive treatment alone in 44 patients with rapidly progressive glomerulonephritis.Hepatitis C virus (HCV) is common in dialysis patients and renal transplant recipients. In 20 anti-HCV positive sera from 1988-91 recombinant immunoblott assay (RIBA) was positive in 8 cases and indeterminate in 7, while HCV RNA was present in 13/20 tested sera. In October 1991 17% of our hemodialysis patients were verified or suspected carriers while 11% were verified or suspected carriers in January 1997. Genotype 2b was found in 13/24 tested cases and in 7 amplifiable 2b sequences a strong phylogenetic relationship occurred. In 8 out of 12 RIBA-3 indeterminate sera HCV-RNA was still positive. Awareness and preventive measures limited transmission between patients.Indeterminate RlBA-results should, also with modem assays, be regarded with caution due to the relative immunodeficiency of uremic patients.In conclusion renal and systemic diseases may affect the serum immunoglobulins and immunoglobulin G-subclasses, while a study of the specific antibody subclass distributions (anti-HBs) showed no difference in renal (dialysis) patients and healthy adults. Medication (hydralazine) and infection may be triggering factors of various forms of glomerulonephritis. Uremia affects the antibody responses to hepatitis C in dialysis patients. The extent of renal disease as well as the possibility of therapeutic removal of antibodies is also important for the immunologic responses of such disorders.
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| 69. |
- Alwin, Jenny, 1978-
(författare)
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Assessment of Support Interventions in Dementia : Methodological and Empirical Studies
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dementia means a continuous deterioration of abilities and has a large impact on the persons affected as well as on family members and others close to the persons with dementia. Interventions aimed at this population in order to support and alleviate the often straining situation may be of great importance. There is a need to increase the knowledge and understanding of the impact and consequences of these interventions, both at an individual level and at a societal level. The demand for information concerning, e.g., economic and medical impact of technologies and interventions within health care is increasing. Assessment of technologies and interventions in dementia is related to certain methodological issues. The overall aim of this thesis is to contribute to the development of methodological knowledge concerning assessment studies and understanding of support interventions in dementia.This thesis work includes four studies that examine methodological aspects of assessment of support interventions in dementia and also report empirical research on the perception of support interventions from the perspectives of family caregivers of persons with dementia. In study I, an assessment model for assistive technology (AT) interventions in dementia was developed. In study II, part of the assessment model is applied, and a process evaluation of the AT intervention is presented. Study III examines family caregivers’ perception of the importance of different types of support and services. In the final study, study IV, a well‐acknowledged methodological challenge within the field of assessment in dementia is addressed: measuring health‐related quality of life (HRQoL). The studies are based on different data materials.An assessment model of AT interventions was developed that includes health economic evaluation from a societal perspective as well as evaluation of the intervention process. The perspectives of both persons with dementia and their relatives were incorporated in the model. The process evaluation was applied in study II in order to study the relatives’ perception of an AT intervention process. Assistive technology interventions in dementia may be of great significance for the relatives. By performing the process evaluation, several important aspects that need to be acknowledged in AT intervention processes in dementia were identified.Family caregivers of persons with dementia perceived different types of support/services within the comprehensive areas of counselling, relief and information as very important. Knowledge of the caregivers’ preferences is significant so that more directed support interventions may be provided.One specific methodological issue was addressed in study IV. The results of study IV showed that there were large differences in the results of cost‐effectiveness analyses depending on whether patient self‐ratings or proxy ratings (ratings of persons close to the patient) of patient HRQoL were used for the same analysis. These differences in the results could ultimately have an important impact on decision making and resource allocation.Support interventions aimed at persons with dementia and their relatives may be of great value. Conducting assessment studies of technologies and interventions within health care is important in order to increase the knowledge concerning, e.g., economic and medical impact. Assessment studies of support interventions dementia entails methodological issues that need to be addressed. There is a need for increased knowledge within this field and suggestions on methodology are made.
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| 70. |
- Amandusson, Åsa, 1974-
(författare)
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Estrogen receptor expression in relation to pain modulation and transmission : experimental studies in rats
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Estrogens have a remarkably wide range of actions in the mammalian brain. They not only play a pivotal role in reproductive behavior and sexual differentiation, but also contribute to e.g. thermoregulation, feeding, memory, neuronal survival and the perception of somatosensory stimuli. A multitude of studies on both animals and human subjects has demonstrated potential effects of gonadal hormones, such as estrogens, on pain transmission. These effects most likely involve multiple neuroanatomical circuits as well as diverse neurochemical systems and therefore need to be evaluated specifically in relation to the localization and intrinsic characteristics of the neurons engaged. The overall aim of this thesis is to gain specific knowledge of the possible cellular mechanisms by which estrogens may influence the transmission of nociceptive stimuli at the level of the spinal cord. The estrogen receptors, by which estrogens regulate non-genomic as well as genomic mechanisms, are crucial to estrogen signaling in general and essential to the estrogen-induced effects in the brain. In Paper I, we use immunohistochemistry to label neurons containing estrogen receptor-! (ERα) in the medullary and spinal dorsal horn of female rats. Large numbers of ER!-expressing neurons were found in lamina I and lamina II, i.e. in the areas involved in the processing of primary afferent nociceptive information. This distribution in part overlaps that of enkephalin, a potent pain-inhibiting endogenous opioid. The effects of gonadal hormones on pain modulation may, to a great extent, be blocked by the opioid antagonist naloxone, suggesting an involvement of the endogenous opioid system in the prosecution of hormonal pain regulation. By combining immunohistochemical labeling of ERα with in situ hybridization of preproenkephalin mRNA (Paper II), we demonstrate that the majority of enkephalinergic neurons in the superficial laminae of the spinal and medullary dorsal horn express ER!. This co-localization and the fact that the preproenkephalin gene contains a sequence that binds ERs, suggest that estrogens may potentially regulate enkephalin expression in these cells. This is further supported by the findings in Paper III in which we show that a single subcutaneous injection of estradiol induces a significant increase (on average 68%) in preproenkephalin mRNA content in the spinal cord after 4 hours. The expression of the enkephalin gene in the spinal cord is thus sensitive to fluctuating estradiol levels. In Paper IV, a noxious injection of formalin is used to induce activation of a neuronal population involved in nociceptive transmission from the face. By using a dual-labeling immunohistochemistry protocol, we were able to identify ER!-expressing cells within this neuronal population suggesting that nociceptive-responsive neurons in the medullary dorsal horn express ER!. In all, our findings provide morphological as well as biochemical evidence in support for an estrogen-dependent modulation of nociceptive processing at the level of the dorsal horn.
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