Winter vertebrate browsing of birch: effects on the use of leaf litter leachates by stream microorganisms

Thesis (M.S.) University of Alaska Fairbanks, 2001Winter browsing of birch leads to chemical changes in leaves of the following growing season, potentially generating differences in the quality of leachates derived from leaf litter and in leachate use by stream microorganisms. The effects of moose browsing were tested on leachates from leaves collected from browsed and unbrowsed trees and inoculated with microbial communities. Respiration and bacterial abundance were used to assess qualitative differences in leachates. Microbes cultured in leachates derived from leaves of browsed trees had significantly higher rates of oxygen uptake. There were no significant differences in bacterial abundance between treatments. The basis for the qualitative difference in leachates is likely due to an 89% greater concentration of amino acides in leachates derived from leaves of previously browsed trees. This study provides evidence that winter herbivory of birch can influence the use of leaf leachates by stream microbes, demonstrating coupling between riparian zones and stream ecosystems

PUROMYCIN-INDUCED NECROSIS OF CRYPT CELLS OF THE SMALL INTESTINE OF MOUSE

Chemical and radioautographic analysis of the small intestine of mice injected intraperitoneally with puromycin revealed an immediate decrease of precursor incorporation into DNA and protein and a delayed decrease of precursor incorporation into RNA. In addition to this decrease of precursor incorporation, damage to the crypt cells, but not to the cells of the villus of the small intestine, was observed. Further examination of other dividing cells (spleen) and nondividing cells (liver and heart) of these mice showed again that only cells of actively dividing tissues were damaged. The metabolic inhibitors actinomycin D, cytosine arabinoside, actidione, and puromycin aminonucleoside were used in an attempt to clarify the mechanism of cell damage by puromycin. The results showed that there was no clear correlation between cell necrosis and the pattern of inhibition of synthesis of DNA, RNA, or protein

Lederspennets betydning for avdelingsleders arbeidshverdag

Utgangspunktet for denne undersøkelsen er interessen for lederspenn og hvordan dette påvirker arbeidshverdagen til førstelinjeledere i helse og omsorgstjenesten. Problemstilling: Hvilke krav opplever avdelingsledere med stort lederspenn og hvordan mestrer de arbeidshverdagen. Det er en kvalitativ studie blant ledere i kommunal helse og omsorgstjeneste med stort lederspenn, med variasjoner fra 25 til 33 årsverk og mellom 51 og 71ansatte. Grunnet sommerferie har flere avdelinger i perioder inntil 90 ansatte. Flere avdelingsledere har fagansvar for mange pasienter og er ledere for flere lokasjoner. Studien har seks informanter. Studien viser at informantene opplever lederspennet stort og at arbeidshverdagen har mange krav, knyttet til rollebelastning, ansattutfordringer, tjenesteproduksjon og avdelingens behov for ledelse. Det kommer også frem ressurser som avdelingslederne har i hverdagen for å balansere jobbkravene. De mest fremtredende ressursene er støtte, personlige egenskaper og tiltak i privatlivet, grensesetting og kontorplass i avdeling. Mestringsstrategier som benyttes for å mestre egen arbeidshverdag er tilstedeværelse i avdeling, brannslukking og delegere oppgaver. Analysen viser at avdelingsledere opplever at når kravene blir for mange og at de mangler ressurser og mestringsstrategier som kan hjelpe lederne i å håndtere kravene. Dette resulterer i mindre tilstedeværelse i avdelingen, noe som igjen bidrar til økt krav og press fra ansatte, tjenestemottakere, administrative oppgaver og økte negative effekter som følge av fraværende leder. Dette bidra til at avdelingslederne kommer inn i en vond sirkel som resulterer i økt belastning. Studiens resultater kan til tross for sitt beskjedene omfang bidra til økt kunnskap om hva som oppleves som krav og ressurser i kommunal helse og omsorgstjeneste. Samtidig er det behov for å finne måter å bidra til økt bruk av aktive mestringsstrategier, som kan bidrar til varig økte ressurser eller mindre/stabile krav. Avdelingsledernes ansvarsområde bør gjennomgås for å avklare hvilken oppgaver som tilhører ansvarsområdet. Nøkkelord: Lederspenn, krav og ressurser, mestringsstrategi, avdelingsleder, kommunal helse og omsorgstjeneste

Vascular function in adults with cyanotic congenital heart disease

Background Patients with cyanotic congenital heart disease (CCHD) may have a low burden of atherosclerosis. Endothelial dysfunction is an early stage of atherosclerosis and endothelial function is previously studied in smaller CCHD groups with different techniques and variable results. We aimed to examine endothelial function and carotid atherosclerosis in a larger group of CCHD patients. Methods This multicentre study assessed endothelial function in adults with CCHD and controls by measuring the dilatory response of the brachial artery to post-ischemic hyperaemia (endothelium-dependent flow-mediated-vasodilatation (FMD)), and to nitroglycerin (endothelium-independent nitroglycerin-induced dilatation (NID)). Flow was measured at baseline and after ischaemia (reactive hyperaemia). Carotid-intima-media-thickness (CIMT), prevalence of carotid plaque and plaque thickness (cPT-max) were evaluated ultrasonographically. Lipoproteins, inflammatory and vascular markers, including sphingosine-1-phosphate (S1P) were measured. Results Forty-five patients with CCHD (median age 50 years) and 45 matched controls (median age 52 years) were included. The patients presented with lower reactive hyperaemia (409 ± 114% vs. 611 ± 248%, p < 0.0001), however preserved FMD response compared to controls (106.5 ± 8.3% vs. 106.4 ± 6.1%, p = 0.95). In contrast, NID was lower in the patients (110.5 ± 6.1% vs. 115.1 ± 7.4%, p = 0.053). There was no difference in CIMT, carotid plaque or cPT-max. The patients presented with lower high-density-lipoprotein cholesterol, and higher level of inflammatory markers and S1P. Conclusion Adults with CCHD had preserved FMD in the brachial artery, but impaired NID response and lower reactive hyperaemia than controls. The preserved FMD and the comparable prevalence of carotid atherosclerosis indicate that CCHD patients have the same risk of atherosclerosis as controls

Short-term outcome after open-heart surgery for severe chronic rheumatic heart disease in a low-income country, with comparison with an historical control group: an observational study

Objectives Rheumatic heart disease (RHD) is a major burden in low-income and middle-income countries (LMICs). Cardiac surgery is the only curative treatment. Little is known about patients with severe chronic RHD operated in LMICs, and challenges regarding postoperative follow-up are an important issue. At Tikur Anbessa Specialised Hospital, Addis Ababa, Ethiopia, we aimed to evaluate the course and 12-month outcome of patients with severe chronic RHD who received open-heart surgery, as compared with the natural course of controls waiting for surgery and undergoing only medical treatment. Methods Clinical data and outcome measures were registered in 46 patients operated during five missions from March 2016 to November 2019, and compared with the first-year course in a cohort of 49 controls from the same hospital’s waiting list for surgery. Adverse events were death or complications such as stroke, other thromboembolic events, bleeding, hospitalisation for heart failure and infectious endocarditis. Results Survival at 12 months was 89% and survival free from complications was 80% in the surgical group. Despite undergoing open-heart surgery, with its inherent risks, outcome measures of the surgical group were non-inferior to the natural course of the control group in the first year after inclusion on the waiting list (p≥0.45). All except six surgical patients were in New York Heart Association class I after 12 months and 84% had resumed working. Conclusions Cardiac surgery for severe chronic RHD is feasible in LMICs if the service is structured and planned. Rates of survival and survival free from complications were similar to those of controls at 12 months. Functional level and resumption of work were high in the surgical group. Whether the patients who underwent cardiac surgery will have better long-term prognosis, in line with what is known in high-income countries, needs to be evaluated in future studies.publishedVersio