Diagnostic testing of autonomous cortisol secretion in adrenal incidentalomas

Objective: Autonomous cortisol secretion (ACS) is a condition with ACTH-independent cortisol overproduction from adrenal incidentalomas (AI) or adrenal hyperplasia. The hypercortisolism is often mild, and most patients lack typical clinical features of overt Cushing’s syndrome (CS). ACS is not well defined and diagnostic tests lack validation. Methods: Retrospective study of 165 patients with AI evaluated clinically and by assay of morning plasma ACTH, late-night saliva cortisol, serum DHEA sulphate (DHEAS), 24-h urine-free cortisol, and cortisol after dexamethasone suppression. Results: Patients with AI (n = 165) were diagnosed as non-functioning incidentalomas (NFI) (n = 82) or ACS (n = 83) according to current European guidelines. Late-night saliva cortisol discriminated poorly between NFI and ACS, showing a high rate of false-positive (23/63) and false-negative (38/69) results. The conventional low-dose dexamethasone suppression test (LDDST) did not improve the diagnostic specificity, compared with the 1 mg overnight DST. Receiver operating characteristic curve analysis of DHEAS in the two cohorts demonstrated an area under the curve of 0.76 (P < 0.01) with a sensitivity for ACS of 58% and a specificity of 80% using the recommended cutoff at 1.04 µmol/L (40 µg/dL). Conclusion: We here demonstrate in a large retrospective cohort of incidentaloma patients, that neither DHEAS, late-night saliva cortisol nor 24-h urine free cortisol are useful to discriminate between non-functioning adrenal incidentalomas and ACS. The conventional LDDST do not add further information compared with the 1 mg overnight DST. Alternative biomarkers are needed to improve the diagnostic workup of ACS.publishedVersio

Development of Biomimetic Robot Leg with ROS Implementation

Denne bacheloroppgaven dokumenterer utviklingen av et overaktuert robotben med fire frihetsgrader. Dette omfatter design, konstruksjon, det matematiske rammeverket, regulering og simulering. Målet med prosjektet er å muliggjøre framtidig forskning på biomimetisk robotbevegelse og skape en fysisk modell for bruk i undervisning innen robotikk. Robotbenet består av fire aktuatorer hvor tre er plassert i samme plan for å etterligne hofte, kne og ankel til en vanlig huskatt. Dette gjør roboten overaktuert hvis den blir sett på i to dimensjoner. 3D-printede deler utgjør de fleste delene som kobler aktuatorene sammen. En enkel anatomisk analyse ble utført for å finne korrekte proporsjoner for hver lenke. Robotbenet er festet til et stativ med kulehjul for å muliggjøre bevegelse. En matematisk modell for kinematikken til roboten ble implementert i Matlab. Dette muliggjorde planlegging av baner mellom viapunkter funnet i en gangeanalyse av katter. Matlab modellen for roboten ble aldri implementert på den fysiske modellen, men er inkludert som grunnlaget for integrasjon mellom Matlab og ROS i framtidig arbeid. En mer komplett matematisk modell og optimal regulerings løsning er også presentert. Det integrerte elektroniske systemet består av fire likestrøms børstemotorer kontrollert av en Arduino Mega som kjører individuell PID-regulator for hvert ledd. Doble motordrivere brukes for å konvertere PID-regulatorens pådragssignal til aktuatorhastighet. Vinkelposisjonen til leddene er målt med inkrementelle enkodere, hvor signalene blir lest og posisjonen lagret av en Arduino Nano for hver aktuator. Kommunikasjonen mellom enhetene er gjort ved hjelp av I2C protokollen, mens mellom Megaen og ROS benyttes seriell USB. Til slutt fungerte det integrerte elektroniske systemet som planlagt med unntak av motorene som viste seg å være for svake for roboten under bruk. Ved å eksportere informasjon fra designfilene ble det laget en robotmodell som kunne brukes i blant annet ROS. Denne muliggjør simulering av bevegelse og ganglag før testing på den fysiske modellen. Baner ble generert ved å sette start og stopp posisjoner for robotbenet. ROS er satt opp til å sende settpunkter til motor regulatorene slik at den fysiske roboten vil følge den planlagte banen. En modell med fire ben er også laget og simulert i ROS. De fleste aspektene ved roboten fungerte til slutt som planlagt, med unntak av aktuatorene som var for svake. Før de sviktet ble det vist at ROS sendte settpunkter til regulatorene og at ønskede posisjoner ble oppnådd. Gitt mer tid eller større budsjett er gruppemedlemmene sikre på at full funksjonalitet ville blitt oppnådd. For å gjøre framtidig arbeid enklere er mye av diskusjonen funnet i denne oppgaven fokusert på framtidig arbeid og mulige forbedringer

Diagnostic testing of autonomous cortisol secretion in adrenal incidentalomas

Objective: Autonomous cortisol secretion (ACS) is a condition with ACTH-independent cortisol overproduction from adrenal incidentalomas (AI) or adrenal hyperplasia. The hypercortisolism is often mild, and most patients lack typical clinical features of overt Cushing’s syndrome (CS). ACS is not well defined and diagnostic tests lack validation. Methods: Retrospective study of 165 patients with AI evaluated clinically and by assay of morning plasma ACTH, late-night saliva cortisol, serum DHEA sulphate (DHEAS), 24-h urine-free cortisol, and cortisol after dexamethasone suppression. Results: Patients with AI (n = 165) were diagnosed as non-functioning incidentalomas (NFI) (n = 82) or ACS (n = 83) according to current European guidelines. Late-night saliva cortisol discriminated poorly between NFI and ACS, showing a high rate of false-positive (23/63) and false-negative (38/69) results. The conventional low-dose dexamethasone suppression test (LDDST) did not improve the diagnostic specificity, compared with the 1 mg overnight DST. Receiver operating characteristic curve analysis of DHEAS in the two cohorts demonstrated an area under the curve of 0.76 (P < 0.01) with a sensitivity for ACS of 58% and a specificity of 80% using the recommended cutoff at 1.04 µmol/L (40 µg/dL). Conclusion: We here demonstrate in a large retrospective cohort of incidentaloma patients, that neither DHEAS, late-night saliva cortisol nor 24-h urine free cortisol are useful to discriminate between non-functioning adrenal incidentalomas and ACS. The conventional LDDST do not add further information compared with the 1 mg overnight DST. Alternative biomarkers are needed to improve the diagnostic workup of ACS

Epilepsy and other seizure disorders in acute psychiatric inpatients

Background: It is well known that patients with epilepsy have a high rate of psychiatric comorbidity. However, studies exploring epilepsy in psychiatric cohorts are scarce. The aim of this study was to examine the prevalence of seizure disorders in acute psychiatric inpatients. Methods: This is a cross-sectional study performed in a catchment-area based acute psychiatric department. All patients (age > 18) admitted during September 2011 - March 2012 were eligible for inclusion. Consenting patients were screened for a life-time history of epilepsy or seizures using self-reported questionnaire data and diagnostic codes for epilepsy in hospital and National registries. Patients scoring positive to one or more of these screening criteria underwent a thorough diagnostic validation (chart review), and the seizure disorders were classified as epilepsy, acute symptomatic seizures and/or psychogenic non-epileptic seizures according to current definitions. Results: A total of 380 out of 591 (64.3%) consecutively admitted patients consented to participate in the study. Eighty-nine patients (23.4%) scored positive to one or more screening criteria. Fifteen (3.9%) were classified with epilepsy, 21 (5.5%) with acute symptomatic seizures and 9 (2.4%) with psychogenic non-epileptic seizures. Conclusions: This is the first study to report on the prevalence of seizure disorders in acute psychiatric inpatients. The life-time prevalence of epilepsy in this cohort of patients is five - six times as high as reports in the general population. These findings underscore the need for the clinical psychiatrist to have comprehensive knowledge on the interface between epileptology and psychiatry. Trials registration: ClinicalTrials.gov identifier NCT01415323

Interplay of choline metabolites and genes in patient-derived breast cancer xenografts

Introduction Dysregulated choline metabolism is a well-known feature of breast cancer, but the underlying mechanisms are not fully understood. In this study, the metabolomic and transcriptomic characteristics of a large panel of human breast cancer xenograft models were mapped, with focus on choline metabolism. Methods Tumor specimens from 34 patient-derived xenograft models were collected and divided in two. One part was examined using high-resolution magic angle spinning (HR-MAS) MR spectroscopy while another part was analyzed using gene expression microarrays. Expression data of genes encoding proteins in the choline metabolism pathway were analyzed and correlated to the levels of choline (Cho), phosphocholine (PCho) and glycerophosphocholine (GPC) using Pearson’s correlation analysis. For comparison purposes, metabolic and gene expression data were collected from human breast tumors belonging to corresponding molecular subgroups. Results Most of the xenograft models were classified as basal-like (N = 19) or luminal B (N = 7). These two subgroups showed significantly different choline metabolic and gene expression profiles. The luminal B xenografts were characterized by a high PCho/GPC ratio while the basal-like xenografts were characterized by highly variable PCho/GPC ratio. Also, Cho, PCho and GPC levels were correlated to expression of several genes encoding proteins in the choline metabolism pathway, including choline kinase alpha (CHKA) and glycerophosphodiester phosphodiesterase domain containing 5 (GDPD5). These characteristics were similar to those found in human tumor samples. Conclusion The higher PCho/GPC ratio found in luminal B compared with most basal-like breast cancer xenograft models and human tissue samples do not correspond to results observed from in vitro studies. It is likely that microenvironmental factors play a role in the in vivo regulation of choline metabolism. Cho, PCho and GPC were correlated to different choline pathway-encoding genes in luminal B compared with basal-like xenografts, suggesting that regulation of choline metabolism may vary between different breast cancer subgroups. The concordance between the metabolic and gene expression profiles from xenograft models with breast cancer tissue samples from patients indicates that these xenografts are representative models of human breast cancer and represent relevant models to study tumor metabolism in vivo

Interplay of choline metabolites and genes in patient-derived breast cancer xenografts

Introduction: Dysregulated choline metabolism is a well-known feature of breast cancer, but the underlying mechanisms are not fully understood. In this study, the metabolomic and transcriptomic characteristics of a large panel of human breast cancer xenograft models were mapped, with focus on choline metabolism. Methods: Tumor specimens from 34 patient-derived xenograft models were collected and divided in two. One part was examined using high-resolution magic angle spinning (HR-MAS) MR spectroscopy while another part was analyzed using gene expression microarrays. Expression data of genes encoding proteins in the choline metabolism pathway were analyzed and correlated to the levels of choline (Cho), phosphocholine (PCho) and glycerophosphocholine (GPC) using Pearson’s correlation analysis. For comparison purposes, metabolic and gene expression data were collected from human breast tumors belonging to corresponding molecular subgroups. Results: Most of the xenograft models were classified as basal-like (N = 19) or luminal B (N = 7). These two subgroups showed significantly different choline metabolic and gene expression profiles. The luminal B xenografts were characterized by a high PCho/GPC ratio while the basal-like xenografts were characterized by highly variable PCho/GPC ratio. Also, Cho, PCho and GPC levels were correlated to expression of several genes encoding proteins in the choline metabolism pathway, including choline kinase alpha (CHKA) and glycerophosphodiester phosphodiesterase domain containing 5 (GDPD5). These characteristics were similar to those found in human tumor samples. Conclusion: The higher PCho/GPC ratio found in luminal B compared with most basal-like breast cancer xenograft models and human tissue samples do not correspond to results observed from in vitro studies. It is likely that microenvironmental factors play a role in the in vivo regulation of choline metabolism. Cho, PCho and GPC were correlated to different choline pathway-encoding genes in luminal B compared with basal-like xenografts, suggesting that regulation of choline metabolism may vary between different breast cancer subgroups. The concordance between the metabolic and gene expression profiles from xenograft models with breast cancer tissue samples from patients indicates that these xenografts are representative models of human breast cancer and represent relevant models to study tumor metabolism in vivo