The disappearance and regrowth of adrenergic innervation in arterial grafts in rats : a microsurgical experimental study

In many fields of surgery the function of transplanted arteries is of crucial importance. In all these fields of surgery vasospasm is regarded as a serious threat to a successful outcome. We still do not fully understand the exact mechanisms behind vasospasm and we studied sympathetic innervation in connection with operative trauma in arterial grafts. When an artery is dissected from its surrounding tissues it loses its sympathetic innervation. To investigate the changes in adrenergic nerves in transplanted arterial grafts in rats, laboratory rats were operated on. Femoral arterial grafts were anastomosed to carotid arteries and compared with control non-operated femoral artery segments. In our first experiment we studied the disappearance of catecholamine fluorescence from noradrenalin-containing sympathetic nerve fibers in arterial grafts. In the first study we used glyoxylic acid-induced fluorescence to demonstrate adrenergic nerves. In the second and third studies we used high-performance liquid chromatography (HPLC) to determine noradrenaline content in grafts. The fourth experiment was performed to characterize neuronal degeneration and regeneration events using immunohistochemistry. Specimens were assessed for vasoactive intestinal peptide, neurofilaments, growth-associated protein 43, tyrosine hydroxylase, and nitric oxide synthase. At six hours postoperatively the network of fibers had started to degenerate, and catecholamine fluorescence from the adrenergic nerves had almost completely disappeared within 24 hours of grafting. Noradrenaline levels rose significantly six hour after grafting, falling to almost nil at 24 hours. The noradrenaline levels started rising one week after the operation reaching 43% of control values at 20 weeks. Immunohistochemistry demonstrated that neuronal markers disappeared within one week from the grafts In the regeneration phase axonal growth was followed by a gradual increase in neurotransmitter markers. This was consistent with the density of neuronal networks in the corresponding arteries in their natural surroundings. Our findings also suggest that the main sequence of degeneration and regeneration follows that reported in other models of neuronal degeneration. They also indicate that innervation density in the graft may differ from that in the host, which may suggest target-derived regulation of innervation.Tässä työssä tutkittiin rotilla valtimosiirteiden sympaattista hermostusta, valtimosiirteillä on kliinistä merkitystä useilla kirurgian erikoisaloilla. Siirretyn valtimon aukipysyvyyttä uhkaa verisuonen supistumien ja veritulppa ja työssä keskityttiin verisuonten supistumiseen vaikuttavaan sympaattiseen hermotukseen. Menetelmänä käytettiin rotan reisivaltimon siirtämistä rotan kaulavaltimoon ja tutkimukset tehtiin siirteille ja toisen puolen leikkaamattomalle reisivaltimolle joka toimi kontrollinäytteenä. Ensimmäisessä osatyössä osoitettiin glyoksyylihapomenetelmällä noradrenaliinin, sympaattisen hermoston välittäjäaineen, häviävän vuorokaudessa verisuonisiirteistä. Toisessa ja kolmannessa osatyössä käytettiin nestekromatografiaa noradrenaliinin määrän mittaamiseen. Niissä osoitettiin noradrenaliinin määrän ensin nousevan merkittävästi kuuden tunnin jälkeen leikkauksesta ja häviävän 48 tunnissa mittausalueen alapuolelle. Viidessä kuukaudessa noradrenaliinin määrä nousi tilastollisesti merkittävästi lähestyen alkuperäistä tasoa. Viimeisessä osatyössä tutkittiin immunohistokemiallisin menetelmin hermojen häviämistä ja uudelleenkasvua valtimosiirteissä käyttäen tyrosiinihydroksylaasientsyymiä, GAP-43 valkuaisainetta, VIP valkuaisainetta, typpioksidia syntetisoivaa NOS entsyymiä, ja neurofilamentteja, hermosolujen tukirakenteita, merkkiaineina. Kaikki hermostolliset merkkiaineet hävisivät viikossa valtimosiirteistä. Niitä alkoi ilmaantua takaisin kuukauden kuluttua leikkauksesta ja viiden kuukauden kohdalla valtimosiirteiden hermotus muistutti reisivaltimon alkuperäistä hermotusta enemmän kuin kaulavaltimon hermotusta. Johtopäätöksenä voidaan esittää sympaattisen hermotuksen häviävän valtimosirteistä pian leikkauksen jälkeen ja vapautuvat välittäjäaineet saattavat olla merkittävä osasyy verisuonten haitalliseen supistumiseen. Viidessä kuukaudessa hermotus kasvaa uudelleen siirteisiin muistuttaen alkuperäistä hermotust

Short-term effects of prescribed burning on wood-rotting fungi.

The prefire fungal flora (polypores and corticoid fungi) of 284 dead trees, mainly fallen trunks of Norway spruce (Picea abies), was studied in 1991 in an old, spruce-dominated mesic forest in southern Finland. Species diversity of the prefire fungal flora was very high, including a high proportion of locally rare species and four threatened polypore species in Finland. In 1992 part of the study area (7.3 ha) was clear-cut and a 1.7 ha forest stand in the center of study area was left standing with a tree volume of 150 m3/ha, and later on (June 1st) in the same year the whole area was burned. Burning was very efficient and all trees in the forest stand were dead one year after the fire. Also the ground layer burned almost completely. In 1993 the fungal flora of the 284 sample trees was studied again. Most of the trees had burned strongly and the fungal species diversity and the evenness in community structure had decreased considerably as compared with the prefire community. Species turnover was also great, especially in corticoid fungi. Greatest losses in the species numbers occurred in moderately and strongly decayed trees, in coniferous trees and in very strongly burned trees. Fungal flora of non-decayed and slightly decayed trees, deciduous trees and slightly burned trees seemed to have survived the fire quite well, and in these groups the species numbers had increased slightly as compared with the prefire community. Fungal species suffering from fire (anthracophobe species) were mainly growing in moderately and strongly decayed trees before the fire, whereas species favoured by fire (anthracophile species) were growing in less decayed trees. No fruitbodies of threatened polypores or other ‘old-forest species’ of polypores were found again after fire. Some very common and effective wood-rotting fungi (e.g. Fomitopsis pinicola, Fomes fomentarius, Antrodia serialis) survived the fire quite well (anthracoxene species). Species favoured by fire were mainly ruderal species which can utilize new, competition-free resources created by fire, and species that have their optima in dry and open places also outside forest-fire areas. Some rarities, e.g. Phanerochaete raduloides and Physisporinus rivulosus, were favoured by fire

Satisfaction of young ENT surgeons with their work. A Finnish national study

The objective was to investigate work satisfaction among recently graduated otorhinolaryngologist - head and neck surgeons - (ENT surgeons). An electronic questionnaire was sent to all ENT surgeons graduated in Finland during a ten-year period. Answers about work satisfaction were analyzed in detail with regards to age, gender, university of specialist training, experience, place of work and further education.Altogether 125/129 (96.9%) responded. The majority (87.8%) of the respondents enjoyed their current main occupation. The older age group (>= 40 vsPeer reviewe

Employment status of young otorhinolaryngologists in Finland during a 10-year period

We determined the employment status of recently graduated otorhinolaryngologist-head and neck surgeons (ENT doctors) in Finland during the past 10 years. We also investigated the job vacancy rate of the Departments of Otorhinolaryngology-Head and Neck Surgery (Department of ORL-HNS). An electronic questionnaire was sent to all ENT doctors who had graduated during 2007-2017 and to chief physicians of all Departments of ORL-HNS. Chi-square and Fisher's test were used in the analyses. Altogether 129 ENT doctors had graduated and 125 (96.9%) responded. Thirty (24%) physicians had been employed in a position that did not correspond to their ENT doctor training. All 30 chief physicians responded and a total of 306 physicians were working at their departments (215 ENT doctors, 91 residents). However, there were only 241 available positions (197 for ENT doctors, 44 for residents). It was estimated that 65 ENT doctors would retire within 10 years. At the moment there does not seem to be a significant shortage of ENT doctors in Finland. The current national volume of resident intake in the ENT training programme is twofold in comparison with the estimated retirement rate in the public sector.Peer reviewe

Circulating nucleosomes as predictive markers of severe acute pancreatitis

Abstract Background The components of nucleosomes, which contain DNA and histones, are released into the circulation from damaged cells and can promote inflammation. We studied whether the on-admission levels of circulating nucleosomes predict the development of severe acute pancreatitis (AP), in particular among the patients who present without clinical signs of organ dysfunction. Methods This is a prospective study of 74 AP patients admitted to Helsinki University Hospital from 2003 to 2007. Twenty-three patients had mild, 27 moderately severe, and 24 severe AP as defined by the revised Atlanta criteria. 14/24 severe AP patients had no sign of organ dysfunction on admission (modified marshall score <2). Blood samples were obtained on admission and the plasma levels of nucleosomes were measured using enzyme-linked immunosorbent assay. Results The on-admission levels of nucleosomes were significantly higher in severe AP than in mild or moderately severe AP (p < 0.001 for all), higher in non-survivors (n = 8) than in survivors (p = 0.019), and correlated with the on-admission levels of C-reactive protein (p < 0.001) and creatinine (p < 0.001). Among the AP patients who presented without organ dysfunction, the on-admission nucleosome level was an independent predictor of severe AP (p = 0.038, gender-adjusted forward-stepping logistic regression). Conclusions Circulating nucleosome levels may be helpful in identifying, on admission to hospital, the AP patients who present without clinical signs of organ dysfunction, and, yet, are bound to develop organ dysfunction during hospitalization

Employment status of young otorhinolaryngologists in Finland during a 10-year period

We determined the employment status of recently graduated otorhinolaryngologist-head and neck surgeons (ENT doctors) in Finland during the past 10 years. We also investigated the job vacancy rate of the Departments of Otorhinolaryngology-Head and Neck Surgery (Department of ORL-HNS). An electronic questionnaire was sent to all ENT doctors who had graduated during 2007-2017 and to chief physicians of all Departments of ORL-HNS. Chi-square and Fisher's test were used in the analyses. Altogether 129 ENT doctors had graduated and 125 (96.9%) responded. Thirty (24%) physicians had been employed in a position that did not correspond to their ENT doctor training. All 30 chief physicians responded and a total of 306 physicians were working at their departments (215 ENT doctors, 91 residents). However, there were only 241 available positions (197 for ENT doctors, 44 for residents). It was estimated that 65 ENT doctors would retire within 10 years. At the moment there does not seem to be a significant shortage of ENT doctors in Finland. The current national volume of resident intake in the ENT training programme is twofold in comparison with the estimated retirement rate in the public sector

Satisfaction of young ENT surgeons with their work. A Finnish national study

The objective was to investigate work satisfaction among recently graduated otorhinolaryngologist - head and neck surgeons - (ENT surgeons). An electronic questionnaire was sent to all ENT surgeons graduated in Finland during a ten-year period. Answers about work satisfaction were analyzed in detail with regards to age, gender, university of specialist training, experience, place of work and further education.Altogether 125/129 (96.9%) responded. The majority (87.8%) of the respondents enjoyed their current main occupation. The older age group (>= 40 vs <40 years) was more satisfied (93.7% vs. 81.7%; p=0.042). Consultation opportunities and workplace atmosphere were reported as good by 85.6% and 90.4% of the respondents, respectively. Training opportunities were considered good by 82.4%, albeit by only 60% of the private physicians (p=0.047). Private sector practitioners were also less satisfied with the versatility of their work (p<0.001). Work at a university hospital was considered more strenuous (p<0.001). Over half (54.8%) felt insecure about continuation of their employment status. Most of the recently graduated Finnish ENT surgeons are satisfied with their current occupation, consultation opportunities and workplace atmosphere. However, work at university hospitals in particular was considered often strenuous and over half of the respondents felt insecure about the continuity of their employment

A methodology for implementing a digital twin of the earth’s forests to match the requirements of different user groups

Publisher Copyright: © 2021 GI_Forum.Europe has acknowledged the need to develop a very high precision digital model of the Earth, a Digital Twin Earth, running on cloud infrastructure to bring data and end-users closer together. We present results of an investigation of a proposed submodel of the digital twin, simulating the worlds’ forests. We focus on the architecture of the system and the key user needs on data content and access. The results are based on a user survey showing that the forest-related communities in Europe require information on contrasting forest variables and processes, with common interest in the status and forecast of forest carbon stock. We discuss the required spatial resolution, accuracies, and modelling tools required to match the needs of the different communities in data availability and simulation of the forest ecosystem. This, together with the knowledge on existing and projected future capabilities, allows us to specify a data architecture to implement the proposed system regionally, with the outlook to expand to continental and global scales. Ultimately, a system simulating the behaviour of forests, a digital twin, would connect the bottom-up and top-down approaches of computing the forest carbon balance: from tree-based accounting of forest growth to atmospheric measurements, respectively.Peer reviewe