Infraslow fluctuations and respiration are driving cortical neurophysiological oscillations during sleep

Abstract. Recently sleep has been linked to increased brain clearance through perivascular spaces from blood-brain barrier (BBB) externa limitans, facilitated by physiological pulsations such as cardiovascular and respiratory pulsations. Infraslow fluctuations (ISFs) characterize both fMRI BOLD signals and scalp EEG potentials. They are associated with both permeability fluctuations of BBB and the amplitude dynamics of faster (> 1Hz) neuronal oscillations. ISF together with respiration are though to synchronize with neural rhythms, however the directionality of these interactions has not been studied before. I used non-invasive measures which are necessary not to interfere the pressure sensitive CSF convection and BBB permeability combined with directional metrics to fully evaluate these relationships. I recorded full-band resting state EEG (fbEEG) during wakefulness and sleep and investigated whether recently shown increased brain clearance during sleep is followed by increased drive of neural amplitudes by the ISF and respiration phases. I show that ISF power increases during non-REM sleep, possibly reflecting altered BBB status. Furthermore, I show that ISF and respiration phase-amplitude couple and predict neuronal brain rhythms seen especially during sleep. These results pave the way for understanding the mechanisms how neuronal activity is modulated by the slow oscillations in human brain during wakefulness and sleep

Elektroenkefalografia:signaalin prosessointimenetelmät ja käyttö unitutkimuksessa

Tiivistelmä. Tutkielman ensimmäinen osa perustuu kirjallisuuskatsaukseen. Siinä tarkastellaan EEG-signaalin syntymekanismeja, laitteistoa ja signaalin ominaisuuksia. Painopisteenä unitutkimus. Tutkielman toinen osa perustuu Oulun yliopistollisessa sairaalassa tehtyyn projektiin. Siinä esitellään muun muassa työkalut, joita voidaan käyttää EEG-signaalin viiveanalyyseissä ja lähde-estimaateissa

Photon Assisted Tunneling of Zero Modes in a Majorana Wire

Hybrid nanowires with proximity-induced superconductivity in the topological regime host Majorana zero modes (MZMs) at their ends, and networks of such structures can produce topologically protected qubits. In a double-island geometry where each segment hosts a pair of MZMs, inter-pair coupling mixes the charge parity of the islands and opens an energy gap between the even and odd charge states at the inter-island charge degeneracy. Here, we report on the spectroscopic measurement of such an energy gap in an InAs/Al double-island device by tracking the position of the microwave-induced quasiparticle (qp) transitions using a radio-frequency (rf) charge sensor. In zero magnetic field, photon assisted tunneling (PAT) of Cooper pairs gives rise to resonant lines in the 2e-2e periodic charge stability diagram. In the presence of a magnetic field aligned along the nanowire, resonance lines are observed parallel to the inter-island charge degeneracy of the 1e-1e periodic charge stability diagram, where the 1e periodicity results from a zero-energy sub-gap state that emerges in magnetic field. Resonant lines in the charge stability diagram indicate coherent photon assisted tunneling of single-electron states, changing the parity of the two islands. The dependence of resonant frequency on detuning indicates a sizable (GHz-scale) hybridization of zero modes across the junction separating islands

Incidence and management of patients with colorectal cancer and synchronous and metachronous colorectal metastases : a population-based study

Background This population-based study aimed to examine the incidence, patterns and results of multimodal management of metastatic colorectal cancer. Methods A retrospective population-based study was conducted on patients with metastatic colorectal cancer in Central Finland in 2000-2015. Clinical and histopathological data were retrieved and descriptive analysis was conducted to determine the pattern of metastatic disease, defined as synchronous, early metachronous (within 12 months of diagnosis of primary disease) and late metachronous (more than 12 months after diagnosis). Subgroups were compared for resection and overall survival (OS) rates. Results Of 1671 patients, 296 (17.7 per cent) had synchronous metastases, and 255 (19.6 per cent) of 1302 patients with resected stage I-III tumours developed metachronous metastases (94 early and 161 late metastases). Liver, pulmonary and intraperitoneal metastases were the most common sites. The commonest metastatic patterns were a combination of liver and lung metastases. The overall metastasectomy rate for patients with synchronous metastases was 16.2 per cent; in this subgroup, 3- and 5-year OS rates after any resection were 63 and 44 per cent respectively, compared with 7.1 and 3.3 per cent following no resection (P <0.001). The resection rate was higher for late than for early metachronous disease (28.0versus17 per cent respectively;P = 0.048). Three- and 5-year OS rates after any resection of metachronous metastases were 78 and 62 per cent respectivelyversus42.1 and 18.2 per cent with no metastasectomy (P <0.001). Similarly, 3- and 5-year OS rates after any metastasectomy for early metachronous metastases were 57 and 50 per centversus84 and 66 per cent for late metachronous metastases (P = 0.293). Conclusion The proportion of patients with metastatic colorectal cancer was consistent with that in earlier population-based studies, as were resection rates for liver and lung metastases and survival after resection. Differentiation between synchronous, early and late metachronous metastases can improve assessment of resectability and survival.Peer reviewe

Prognostic significance of spatial and density analysis of T lymphocytes in colorectal cancer

Background Although high T cell density is a strong favourable prognostic factor in colorectal cancer, the significance of the spatial distribution of T cells is incompletely understood. We aimed to evaluate the prognostic significance of tumour cell-T cell co-localisation and T cell densities. Methods We analysed CD3 and CD8 immunohistochemistry in a study cohort of 983 colorectal cancer patients and a validation cohort (N = 246). Individual immune and tumour cells were identified to calculate T cell densities (to derive T cell density score) and G-cross function values, estimating the likelihood of tumour cells being co-located with T cells within 20 mu m radius (to derive T cell proximity score). Results High T cell proximity score associated with longer cancer-specific survival in both the study cohort [adjusted HR for high (vs. low) 0.33, 95% CI 0.20-0.52, P-trend < 0.0001] and the validation cohort [adjusted HR for high (vs. low) 0.15, 95% CI 0.05-0.45, P-trend < 0.0001] and its prognostic value was independent of T cell density score. Conclusions The spatial point pattern analysis of tumour cell-T cell co-localisation could provide detailed information on colorectal cancer prognosis, supporting the value of spatial measurement of T cell infiltrates as a novel, robust tumour-immune biomarker.Peer reviewe

Impact of Age and Comorbidity on Multimodal Management and Survival from Colorectal Cancer: A Population-Based Study

This retrospective population-based study examined the impact of age and comorbidity burden on multimodal management and survival from colorectal cancer (CRC). From 2000 to 2015, 1479 consecutive patients, who underwent surgical resection for CRC, were reviewed for age-adjusted Charlson comorbidity index (ACCI) including 19 well-defined weighted comorbidities. The impact of ACCI on multimodal management and survival was compared between low (score 0–2), intermediate (score 3) and high ACCI (score ≥ 4) groups. Changes in treatment from 2000 to 2015 were seen next to a major increase of laparoscopic surgery, increased use of adjuvant chemotherapy and an intensified treatment of metastatic disease. Patients with a high ACCI score were, by definition, older and had higher comorbidity. Major elective and emergency resections for colon carcinoma were evenly performed between the ACCI groups, as were laparoscopic and open resections. (Chemo)radiotherapy for rectal carcinoma was less frequently used, and a higher rate of local excisions, and consequently lower rate of major elective resections, was performed in the high ACCI group. Adjuvant chemotherapy and metastasectomy were less frequently used in the ACCI high group. Overall and cancer-specific survival from stage I-III CRC remained stable over time, but survival from stage IV improved. However, the 5-year overall survival from stage I–IV colon and rectal carcinoma was worse in the high ACCI group compared to the low ACCI group. Five-year cancer-specific and disease-free survival rates did not differ significantly by the ACCI. Cox proportional hazard analysis showed that high ACCI was an independent predictor of poor overall survival (p < 0.001). Our results show that despite improvements in multimodal management over time, old age and high comorbidity burden affect the use of adjuvant chemotherapy, preoperative (chemo)radiotherapy and management of metastatic disease, and worsen overall survival from CRC

Impact of Age and Comorbidity on Multimodal Management and Survival from Colorectal Cancer: A Population-Based Study

This retrospective population-based study examined the impact of age and comorbidity burden on multimodal management and survival from colorectal cancer (CRC). From 2000 to 2015, 1479 consecutive patients, who underwent surgical resection for CRC, were reviewed for age-adjusted Charlson comorbidity index (ACCI) including 19 well-defined weighted comorbidities. The impact of ACCI on multimodal management and survival was compared between low (score 0–2), intermediate (score 3) and high ACCI (score ≥ 4) groups. Changes in treatment from 2000 to 2015 were seen next to a major increase of laparoscopic surgery, increased use of adjuvant chemotherapy and an intensified treatment of metastatic disease. Patients with a high ACCI score were, by definition, older and had higher comorbidity. Major elective and emergency resections for colon carcinoma were evenly performed between the ACCI groups, as were laparoscopic and open resections. (Chemo)radiotherapy for rectal carcinoma was less frequently used, and a higher rate of local excisions, and consequently lower rate of major elective resections, was performed in the high ACCI group. Adjuvant chemotherapy and metastasectomy were less frequently used in the ACCI high group. Overall and cancer-specific survival from stage I-III CRC remained stable over time, but survival from stage IV improved. However, the 5-year overall survival from stage I–IV colon and rectal carcinoma was worse in the high ACCI group compared to the low ACCI group. Five-year cancer-specific and disease-free survival rates did not differ significantly by the ACCI. Cox proportional hazard analysis showed that high ACCI was an independent predictor of poor overall survival (p < 0.001). Our results show that despite improvements in multimodal management over time, old age and high comorbidity burden affect the use of adjuvant chemotherapy, preoperative (chemo)radiotherapy and management of metastatic disease, and worsen overall survival from CRC

Human pluripotent stem cell-derived cells endogenously expressing follicle-stimulating hormone receptors : modeling the function of an inactivating receptor mutation

Follicle-stimulating hormone (FSH) is crucial in the development and regulation of reproductive functions. The actions of human FSH and its receptor (FSHR) and mutations therein have mainly been studied using in vivo models, primary cells, cancer cells and cell lines ectopically expressing the FSHR. To allow studies of endogenous FSHR function in vitro, we differentiated FSHR-expressing cells from human pluripotent stem cells. FSH stimulation of the wild-type (WT), but not the inactivating Finnish founder mutant (A189V) receptor, activated the canonical cyclic adenosine monophosphate (cAMP)-dependent signaling pathway and downstream mediators. To investigate protein-protein interaction partners of FSHR at resting state and upon FSH stimulation, we expressed FSHR in HEK293 cells followed by affinity purification mass spectrometry analyses. We found 19 specific high-confidence interacting proteins for WT FSHR and 14 for A189V FSHR, several of which have been linked to infertility. Interestingly, while only WT FSHR interacted with FSH, insulin-like growth factor 1 receptor (IGF1R), for example, interacted with both WT and A189V FSHR upon FSH stimulation. In conclusion, our protocol allows detailed studies of FSH action and disease modeling in human cells endogenously expressing FSHR.Peer reviewe

Human pluripotent stem cell-derived cells endogenously expressing follicle-stimulating hormone receptors : modeling the function of an inactivating receptor mutation

Follicle-stimulating hormone (FSH) is crucial in the development and regulation of reproductive functions. The actions of human FSH and its receptor (FSHR) and mutations therein have mainly been studied using in vivo models, primary cells, cancer cells and cell lines ectopically expressing the FSHR. To allow studies of endogenous FSHR function in vitro, we differentiated FSHR-expressing cells from human pluripotent stem cells. FSH stimulation of the wild-type (WT), but not the inactivating Finnish founder mutant (A189V) receptor, activated the canonical cyclic adenosine monophosphate (cAMP)-dependent signaling pathway and downstream mediators. To investigate protein-protein interaction partners of FSHR at resting state and upon FSH stimulation, we expressed FSHR in HEK293 cells followed by affinity purification mass spectrometry analyses. We found 19 specific high-confidence interacting proteins for WT FSHR and 14 for A189V FSHR, several of which have been linked to infertility. Interestingly, while only WT FSHR interacted with FSH, insulin-like growth factor 1 receptor (IGF1R), for example, interacted with both WT and A189V FSHR upon FSH stimulation. In conclusion, our protocol allows detailed studies of FSH action and disease modeling in human cells endogenously expressing FSHR.Peer reviewe