Browsing by Subject "PRESERVATION"

Sort by: Order: Results:

Now showing items 1-13 of 13
  • Choque-Velasquez, Joham; Colasanti , Roberto; Rezai Jahromi, Behnam; Hernesniemi, Juha (2017)
    OBJECTIVE: The preservation of normal peri/intralesional bridging veins is extremely important in every micro-neurosurgical operation. The purpose of our study was to describe the "squeeze maneuver"assisted by indocyanine green videoangiography (ICGV), a simple technique to "resuscitate" partially occluded bridging veins during microneurosurgical operations. METHODS: When a bridging vein is inadvertently stretched up to its collapse during microneurosurgical procedures, a precise identification of the partially occluded zone is carried out under high magnification (10-153), as well as with the aid of the ICGV. If a continuous irrigation with isotonic saline solution does not allow one to reestablish the venous flow, the "squeeze maneuver" is carried out. This consists of squeezing and sliding with the bipolar forceps the occluded vessel along the normal venous flow direction. This procedure is repeated several times, while a continuous saline irriga-tion is applied. The ICGV is performed to confirm an adequate patency of the vein. RESULTS: This maneuver permits to restore the normal diameter of the vein and blood flow inside it. CONCLUSION: The "squeeze maneuver"assisted by ICGV represents a safe, clean, fast, and even cheap method for restoring the flow of partially occluded bridging veins during microneurosurgical operations.
  • Yurtseva, Anastasia; Noreikiene, Kristina; Lajus, Dmitry; Li, Zitong; Alapassi, Tarja; Ivanova, Tatiana; Ivanov, Mikhail; Golovin, Pavel; Vesala, Sami; Merilä, Juha (2019)
    In order to assess the accuracy and reliability of age estimates from calcified structures in the three-spined stickleback Gasterosteus aculeatus, we evaluated intra and inter-reader repeatability from three structures: otoliths, gill covers and pelvic spines). Average age estimates were also compared between the structures. The overall intra-reader repeatability of age estimates were highest for otoliths (69%), lowest for gill covers (53%) and intermediate for spine cross-sections (63%). Although four of the seven readers had the highest intra-reader repeatability score for spine cross-sections, the inter-reader variance in this structure was much higher than in others. Otoliths were the easiest in terms of their pre-analysis treatment and exchange of materials (as digital images) between readers. In addition, otoliths are more well-studied compared with the other structures with respect to their development through ontogenesis; hence, age estimates based on otoliths should be the most reliable. Therefore, our recommendation is that whenever possible, analysis of otoliths should be the preferred approach for aging G. aculeatus.
  • Häkkinen, Arja; Borg, Håkan; Hakulinen, Mikko; Jurvelin, Jukka; Anttila, Esa; Parviainen, Tapani; Kiviranta, Ilkka (2011)
  • Auvinen, Vili-Veli; Merivaara, Arto; Kiiskinen, Jasmi; Paukkonen, Heli; Laurén, Patrick; Hakkarainen, Tiina; Koivuniemi, Raili; Sarkanen, Riina; Ylikomi, Timo; Laaksonen, Timo; Yliperttula, Marjo (2019)
    The aim of this study was to evaluate the effects of two nanofibrillated cellulose (NFC) hydrogels on two human derivatives during freeze-drying. Native NFC hydrogel is a suitable platform to culture 3D cell spheroids and a hydrogel processed further, called anionic NFC (ANFC) hydrogel, is an excellent platform for controlled release of proteins. Moreover, it has been shown to be compatible with freeze-drying when correct lyoprotectants are implemented. Freeze-drying is a method, where substance is first frozen, and then vacuum dried trough sublimation of water in order to achieve dry matter without the loss of the original three-dimensional structures. The first chosen human derivative was adipose tissue extract (ATE) which is a cell-free growth factor-rich preparation capable of promoting growth of regenerative cells. The release of growth factors from the freeze-dried mixture of ATE and ANFC was compared to that of non-freeze-dried control mixtures. The release profiles remained at the same level after freeze-drying. The second derivative was hepatocellular carcinoma (HepG2) cell spheroids which were evaluated before and after freeze-drying. The 3D structure of the HepG2 cell spheroids was preserved and the spheroids retained 18% of their metabolic activity after rehydration. However, the freeze-dried and rehydrated HepG2 cell spheroids did not proliferate and the cell membrane was damaged by fusion and formation of crystals.
  • Harkonen, Kati; Kivekas, Ilkka; Kotti, Voitto; Sivonen, Ville; Vasama, Juha-Pekka (2017)
    The objective of the present study is to evaluate the effect of hybrid cochlear implantation (hCI) on quality of life (QoL), quality of hearing (QoH), and working performance in adult patients, and to compare the long-term results of patients with hCI to those of patients with conventional unilateral cochlear implantation (CI), bilateral CI, and single-sided deafness (SSD) with CI. Sound localization accuracy and speech-in-noise test were also compared between these groups. Eight patients with high-frequency sensorineural hearing loss of unknown etiology were selected in the study. Patients with hCI had better long-term speech perception in noise than uni- or bilateral CI patients, but the difference was not statistically significant. The sound localization accuracy was equal in the hCI, bilateral CI, and SSD patients. QoH was statistically significantly better in bilateral CI patients than in the others. In hCI patients, residual hearing was preserved in all patients after the surgery. During the 3.6-year follow-up, the mean hearing threshold at 125-500 Hz decreased on average by 15 dB HL in the implanted ear. QoL and working performance improved significantly in all CI patients. Hearing outcomes with hCI are comparable to the results of bilateral CI or CI with SSD, but hearing in noise and sound localization are statistically significantly better than with unilateral CI. Interestingly, the impact of CI on QoL, QoH, and working performance was similar in all groups.
  • Dodd, Matthew S.; Papineau, Dominic; Pirajno, Franco; Wan, Yusheng; Karhu, Juha A. (2019)
    The cycling of iron and organic matter (OM) is thought to have been a major biogeochemical cycle in the early ferruginous oceans which contributed to the deposition of banded iron formations (BIF). However, BIF are deficient in OM, which is postulated to be the result of near-complete oxidation of OM during iron reduction. We test this idea by documenting the prevalence of OM in clays within BIF and clays in shales associated with BIF. We find in shales >80% of OM occurs in clays, but
  • Kiuru, O.; Sinervo, J.; Vähänikkilä, H.; Anttonen, V.; Tjäderhane, L. (2021)
    Objectives. Resin-dentin bond strength decreases over time. This reduction is related to the loss of hybrid layer integrity. Collagenolytic enzymes, especially matrix metalloproteinases (MMPs), are responsible for the degradation of the collagen matrix of the hybrid layer. Various MMP inhibitors with the ability to prevent enzymatic degradation have been identified. This study aimed to systematically review the literature for studies which evaluated the effect of MMP inhibitors on the immediate and aged dentin bond strengths. Study SelectionScreening and analysis were carried out by two reviewers. Two databases were searched, and from a total of 740 articles, 43 were accepted for full review. 21 articles with 0.2%-2% chlorhexidine (CHX) treatments were included for meta-analysis. A risk of bias assessment was performed on all studies chosen for meta-analysis. A variety of MMP inhibitors have been studied, CHX being the most widely used. Conclusions. A clear trend for a lower loss of dentin bond strength was observed with different MMP inhibitors. In meta-analysis, no significant difference was seen between the CHX and control in the immediate bond strengths. Bond strengths in the CHX group were significantly higher than the control group after aging (P
  • Brauer, Anna; Mäkinen, Ville; Forsch, Axel; Oksanen, Juha; Haunert, Jan-Henrik (2022)
    Ever since location-based services and mobile applications collecting data gathered through Global Navigation Satellite System (GNSS) positioning have become popular, concerns about location privacy have been expressed. Research has shown that human trajectory repositories containing sequences of observed locations ordered in time constitute a rich source for analyzing movement patterns, but they can also reveal sensitive personal information, such as a person's home address. In this paper, we present a mechanism that protects visits to sensitive locations by suppressing revealing parts of trajectories. Our attack model acknowledges that the course of a trajectory, combined with spatial context information, can facilitate privacy breaches even if sensitive locations have been concealed. Thus, we introduce the concept of k-site-unidentifiability, a specialization of k-anonymity, under which a sensitive location cannot be singled out from a group of at least k sites that the trajectory could have visited. In an experimental study, we show that our method is utility-preserving and protects sensitive locations reliably even in sparsely built environments. As it can process each trajectory independently, individuals may also use our mechanism to enhance their privacy before publishing their trajectories.
  • Martinez Molina, Noelia; Siponkoski, Sini-Tuuli; Pitkäniemi, Anni; Moisseinen, Nella; Kuusela, Linda; Pekkola, Johanna; Laitinen, Sari; Särkämö, Essi-Reetta; Melkas, Susanna; Kleber, Boris; Schlaug, Gottfried; Sihvonen, Aleksi; Särkämö, Teppo (2022)
    A classical observation in neurology is that aphasic stroke patients with impairments in speech production can nonetheless sing the same utterances. This preserved ability suggests a distinctive neural architecture for singing that could contribute to speech recovery. However, to date, these structural correlates remain unknown. Here, we combined a multivariate lesion–symptom mapping and voxel-based morphometry approach to analyse the relationship between lesion patterns and grey matter volume and production rate in speech and singing tasks. Lesion patterns for spontaneous speech and cued repetition extended into frontal, temporal and parietal areas typically reported within the speech production network. Impairment in spontaneous singing was associated with damage to the left anterior–posterior superior and middle temporal gyri. Preservation of grey matter volume in the same regions where damage led to poor speech and singing production supported better performance in these tasks. When dividing the patients into fluent and dysfluent singers based on the singing performance from demographically matched controls, we found that the preservation of the left middle temporal gyrus was related to better spontaneous singing. These findings provide insights into the structural correlates of singing in chronic aphasia and may serve as biomarkers to predict treatment response in clinical trials using singing-based interventions for speech rehabilitation.
  • Kiviniemi, Vesa; Korhonen, Vesa; Kortelainen, Jukka; Rytky, Seppo; Keinanen, Tuija; Tuovinen, Timo; Isokangas, Matti; Sonkajarvi, Eila; Siniluoto, Topi; Nikkinen, Juha; Alahuhta, Seppo; Tervonen, Osmo; Turpeenniemi-Hujanen, Taina; Myllyla, Teemu; Kuittinen, Outi; Voipio, Juha (2017)
    Chemotherapy aided by opening of the blood-brain barrier with intra-arterial infusion of hyperosmolar mannitol improves the outcome in primary central nervous system lymphoma. Proper opening of the blood-brain barrier is crucial for the treatment, yet there are no means available for its real-time monitoring. The intact blood-brain barrier maintains a mV-level electrical potential difference between blood and brain tissue, giving rise to a measurable electrical signal at the scalp. Therefore, we used direct-current electroencephalography ( DC-EEG) to characterize the spatiotemporal behavior of scalp-recorded slow electrical signals during blood-brain barrier opening. Nine anesthetized patients receiving chemotherapy were monitored continuously during 47 blood-brain barrier openings induced by carotid or vertebral artery mannitol infusion. Left or right carotid artery mannitol infusion generated a strongly lateralized DC-EEG response that began with a 2 min negative shift of up to 2000 mu V followed by a positive shift lasting up to 20 min above the infused carotid artery territory, whereas contralateral responses were of opposite polarity. Vertebral artery mannitol infusion gave rise to a minimally lateralized and more uniformly distributed slow negative response with a posterior-frontal gradient. Simultaneously performed near-infrared spectroscopy detected a multiphasic response beginning with mannitol-bolus induced dilution of blood and ending in a prolonged increase in the oxy/deoxyhemoglobin ratio. The pronounced DC-EEG shifts are readily accounted for by opening and sealing of the blood-brain barrier. These data show that DC-EEG is a promising real-time monitoring tool for bloodbrain barrier disruption augmented drug delivery.
  • Wagner, Magdalena; Yoshihara, Masahito; Douagi, Iyadh; Damdimopoulos, Anastasios; Panula, Sarita; Petropoulos, Sophie; Lu, Haojiang; Pettersson, Karin; Palm, Kerstin; Katayama, Shintaro; Hovatta, Outi; Kere, Juha; Lanner, Fredrik; Damdimopoulou, Pauliina (2020)
    The human ovary orchestrates sex hormone production and undergoes monthly structural changes to release mature oocytes. The outer lining of the ovary (cortex) has a key role in defining fertility in women as it harbors the ovarian reserve. It has been postulated that putative oogonial stem cells exist in the ovarian cortex and that these can be captured by DDX4 antibody isolation. Here, we report single-cell transcriptomes and cell surface antigen profiles of over 24,000 cells from high quality ovarian cortex samples from 21 patients. Our data identify transcriptional profiles of six main cell types; oocytes, granulosa cells, immune cells, endothelial cells, perivascular cells, and stromal cells. Cells captured by DDX4 antibody are perivascular cells, not oogonial stem cells. Our data do not support the existence of germline stem cells in adult human ovaries, thereby reinforcing the dogma of a limited ovarian reserve. The outer lining or cortex of the human ovary determines fertility and has been postulated to contain oogonial stem cells. Here, the authors generate a single-cell map of the adult human ovarian cortex and show that DDX4 labels perivascular cells but no oogonial stem cells.
  • Yli-Halla, Markku; Lötjönen, Timo; Kekkonen, Jarkko; Virtanen, Seija; Marttila, Hannu; Liimatainen, Maarit; Saari, Markus; Mikkola, Jarmo; Suomela, Raija; Joki-Tokola, Erkki (2022)
    The off-site effects of agricultural organic soils include the leaching of N, P, and organic carbon (OC) to watercourses and CO2, CH4, and N2O emissions into the atmosphere. The aim of this study was to quantify how the thickness of organic layers affects these loads. A 19.56-ha experimental field drained by subsurface pipes was established in Ruukki, northwestern Finland. Three plots had a 60–80 cm-thick sedge peat layer and three others had a thickness of 20 cm or less. The drainage pipes lie in mineral soil that, in this field, contains sulfidic material. This study documents the experimental settings and reports on the leaching of substances in the first two years, as well as CO2, CH4 and N2O emissions during eight weeks in one summer. Total N (TN) and OC loads were higher from the thicker peat plots. The mean TN loads during a hydrological year were 15.4 and 9.2 kg ha-1 from the thicker and thinner peat plots, respectively, with organic N representing 36% of TN load. Total P (TP) load averaged 0.27 kg ha-1 yr-1. Dissolved P load represented 63 and 36% of TP in the thicker peat area and only 23 and 13% in the thinner peat area, and was thus increased upon peat thickness. These N and P loads through the subsurface drainage system represented roughly 83% of TN and 64% of TP loads from this field. There were no clear differences in greenhouse gas emissions among the plots during the eight-week monitoring period. Slowly oxidizing sulfide in the subsoil resulted in annual leaching of 147 kg S ha-1, almost ten times that of non-sulfidic soils. Our first results emphasize the effect of the peat thickness on the leaching of substances and warn about considering all organic soils as a single group in environmental assessments.
  • Mustonen, Laura; Aho, Tommi; Harno, Hanna; Sipilä, Reetta; Meretoja, Tuomo; Kalso, Eija (2019)
    Nerve injury during breast cancer surgery can cause neuropathic pain (NP). It is not known why some, but not all, patients develop chronic postsurgical neuropathic pain (CPSNP) after the same nerve injury. In this study, we examined 251 breast cancer survivors with surgeon-verified intercostobrachial nerve resection to identify factors that associate with CPSNP. The patients were recruited from a previous study of 1000 women treated for breast cancer in 2006 to 2010. This enabled us to analyze preoperative factors that associate with future CPSNP. The patients were re-examined in 2014 to 2016 to diagnose CPSNP using the revised NP diagnostic criteria. Preoperative assessments were pain in the area to be operated on, any chronic pain condition, depressive symptoms, anxiety, sleep, and experimental cold pain sensitivity using the cold pressor test (CPT). Follow-up assessments were CPT, psychological factors, sleep, any chronic pain, and basic laboratory tests. One hundred thirty-seven (55%) patients with intercostobrachial nerve resection fulfilled CPSNP diagnostic criteria after 4 to 9 years. Of them, 30 patients (22%) had moderate to severe pain in self-reports and 86 (63%) presented moderate to severe evoked pain at examination. Preoperative pain in the surgical area, other chronic pains, and breast-conserving surgery were associated with future CPSNP. Other chronic pains, increased psychological burden, and insomnia, both before surgery and at the follow-up, were associated with CPSNP. Preoperative CPT did not associate with future CPSNP. Patients with established CPSNP showed increased pain sensitivity in CPT and higher levels of inflammatory markers, suggesting that central sensitization and inflammation may associate with the maintenance of CPSNP.