The safety and short-term benefits of laparoscopic colectomy for cancer remain debatable. The multicentre COLOR (COlon cancer Laparoscopic or Open Resection) trial was done to assess the safety and ...benefit of laparoscopic resection compared with open resection for curative treatment of patients with cancer of the right or left colon.
627 patients were randomly assigned to laparoscopic surgery and 621 patients to open surgery. The primary endpoint was cancer-free survival 3 years after surgery. Secondary outcomes were short-term morbidity and mortality, number of positive resection margins, local recurrence, port-site or wound-site recurrence, metastasis, overall survival, and blood loss during surgery. Analysis was by intention to treat. Here, clinical characteristics, operative findings, and postoperative outcome are reported.
Patients assigned laparoscopic resection had less blood loss compared with those assigned open resection (median 100 mL range 0–2700
vs 175 mL 0–2000, p<0·0001), although laparoscopic surgery lasted 30 min longer than did open surgery (p<0·0001). Conversion to open surgery was needed for 91 (17%) patients undergoing the laparoscopic procedure. Radicality of resection as assessed by number of removed lymph nodes and length of resected oral and aboral bowel did not differ between groups. Laparoscopic colectomy was associated with earlier recovery of bowel function (p<0·0001), need for fewer analgesics, and with a shorter hospital stay (p<0·0001) compared with open colectomy. Morbidity and mortality 28 days after colectomy did not differ between groups.
Laparoscopic surgery can be used for safe and radical resection of cancer in the right, left, and sigmoid colon.
Polyethylenimine (PEI) is one of the most efficient nonviral vectors for gene therapy. The aim of this study was to investigate the role of endocytosis in the transfection of synchronized L929 ...fibroblasts by PEI/DNA complexes. This was performed by confocal microscopy and flow cytometry, using the endocytosis marker FM4-64 and PEI/DNA complexes labeled either with the DNA intercalator YOYO-1, or with fluorescein covalently linked to PEI. Endocytosis appeared as the major if not the sole mode of entry of the PEI/DNA complexes into the L929 cells. The complexes followed a typical fluid phase endocytosis pathway and were efficiently taken up in less than 10 min in endosomes that did not exceed 200 nm in diameter. Later, the localization of the complexes became perinuclear and fusion between late endosomes was shown to occur. Comparison with the intracellular trafficking of the same complexes in EA.hy 926 cells (W.T. Godbey, K. Wu, A.G. Mikos, Proc. Natl. Acad. Sci. USA 96 (1999)) revealed that endocytosis of PEI/DNA complexes is strongly cell-dependent. In L929 cells, escape of the complexes from the endosomes is a major barrier for transfection. This limited the number of transfected cells to a few percent, even though an internalization of PEI/DNA complexes was observed in most cells. In addition, the entry of the complexes into the nucleus apparently required a mitosis and did not involve the lipids of the endosome membrane. This entry seems to be a short-lived event that involves only a few complexes.
Approximately 1700 Pg of soil carbon (C) are stored in the northern circumpolar permafrost zone, more than twice as much C than in the atmosphere. The overall amount, rate, and form of C released to ...the atmosphere in a warmer world will influence the strength of the permafrost C feedback to climate change. We used a survey to quantify variability in the perception of the vulnerability of permafrost C to climate change. Experts were asked to provide quantitative estimates of permafrost change in response to four scenarios of warming. For the highest warming scenario (RCP 8.5), experts hypothesized that C release from permafrost zone soils could be 19–45 Pg C by 2040, 162–288 Pg C by 2100, and 381–616 Pg C by 2300 in CO
2
equivalent using 100-year CH
4
global warming potential (GWP). These values become 50 % larger using 20-year CH
4
GWP, with a third to a half of expected climate forcing coming from CH
4
even though CH
4
was only 2.3 % of the expected C release. Experts projected that two-thirds of this release could be avoided under the lowest warming scenario (RCP 2.6). These results highlight the potential risk from permafrost thaw and serve to frame a hypothesis about the magnitude of this feedback to climate change. However, the level of emissions proposed here are unlikely to overshadow the impact of fossil fuel burning, which will continue to be the main source of C emissions and climate forcing.
As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release ...will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
A lake sediment record from the north-eastern European Russian Arctic was examined using palaeolimnological methods, including subfossil chironomid and diatom analysis. The objective of this study is ...to disentangle environmental history of the lake and climate variability during the past 2000 years. The sediment profile was divided into two main sections following changes in the lithology, separating the limno-telmatic phase between ~2000 and 1200 cal. yr BP and the lacustrine phase between ~1200 cal. yr BP and the present. Owing to the large proportion of semi-terrestrial chironomids and poor modern analogues, a reliable chironomid-based temperature reconstruction for the limno-telmatic phase was not possible. However, the lacustrine phase showed gradually cooling climate conditions from ~1200 cal. yr BP until ~700 cal. yr BP. The increase in stream chironomids within this sediment section indicates that this period may also have had increased precipitation that caused the adjacent river to overflow, subsequently transporting chironomids to the lacustrine basin. After a short-lived warm phase at ~700 cal. yr BP, the climate again cooled, and a progressive climate warming trend was evident from the most recent sediment samples, where the biological assemblages seem to have experienced an eutrophication-like response to climate warming. The temperature reconstruction showed more similarities with the climate development in the Siberian side of the Urals than with northern Europe. This study provides a characteristic archive of arctic lake ontogeny and a valuable temperature record from a remote climate-sensitive area of northern Russia.
High hospital case volume has been associated with improved outcome after open operation for colorectal malignancies.
To assess the impact of hospital case volume on short-term outcome after ...laparoscopic operation for colon cancer, we conducted an analysis of patients who underwent laparoscopic colon resection within the COlon Cancer Laparoscopic or Open Resection (COLOR) trial.
A total of 536 patients with adenocarcinoma of the colon were included in the analysis. Median operating time was 240, 210 and 188 min in centers with low, medium, and high case volumes, respectively (p < 0.001). A significant difference in conversion rate was observed among low, medium, and high case volume hospitals (24% vs 24% vs 9%; p < 0.001). A higher number of lymph nodes were harvested at high case volume hospitals (p < 0.001). After operation, fewer complications (p = 0.006) and a shorter hospital stay (p < 0.001) were observed in patients treated at hospitals with high caseloads.
Laparoscopic operation for colon cancer at hospitals with high caseloads appears to be associated with improved short-term results.
This study presents a detailed analysis of geochemical and biotic proxies in a lake sediment profile to assess the effects of local and regional environmental drivers on the Holocene development of ...Lake Loitsana, situated in the northern boreal forest of NE Finland. Multi-proxy studies, in particular those that include a detailed plant macrofossil record, from the part of the northern boreal zone of Fennoscandia which has not been affected by treeline fluctuations, are scarce and few of these records date back to the earliest part of the Holocene. A 9-m sediment sequence of gyttja overlying silts representing the last c. 10,700 cal year, allowed for a high-resolution study with emphasis on the early to mid-Holocene lake history. The lacustrine sediments were studied using lithology, loss-on-ignition and C/N ratios, micro- and macro-fossils of aquatic and wetland taxa, diatoms, chironomids and accelerator mass spectrometry ¹⁴C dating on terrestrial plant macrofossils. Our study shows that the local development at Loitsana was complex and included a distinct glacial lake phase and subsequent drainage, a history of fluvial input affected by nearby wetland expansion, and lake infilling in an eventual esker-fed shallow lake. Enhanced trophic conditions, due to morphometric eutrophication, are recorded as Glacial Lake Sokli drained and open water conditions became restricted to a relatively small Lake Loitsana depression. pH appears to have been stable throughout the Holocene with a well-buffered lake due to the local carbonatite bedrock (Sokli Carbonatite Massif). The fossil assemblage changes are best explained by a complex mixture of drivers, including water-body conditions (i.e. depth, turbidity and turbulence), rate of sediment input, and the general infilling of the lake, highlighting the need to carefully evaluate the possible influence of such local factors as palaeoenvironmental conditions are reconstructed based on aquatic proxies.
Stable carbon and oxygen isotope ratios in single plant components in Sphagnum peat have a good potential to reveal environmental changes in peat archives. Two peat profiles, covering the past ∼
6000
...years, and a Sphagnum hummock from a discontinuous permafrost area in west central Canada were studied in order to evaluate the effect of decomposition rate on isotope records and to assess which plant components are most suitable for climate reconstructions. The stable isotope values from the most recently forming Sphagnum tissues were compared with observational climate data to study the impact of variations in temperature and precipitation on the peat isotopes. Our results show that there is high correlation between δ
13C values in α-cellulose isolated from
Sphagnum fuscum stems and summer temperatures, whereas δ
18O in the plant tissues is controlled by several factors, such as summer precipitation, summer temperature and evaporation. According to our results, decomposition as derived from C/N values and colorimetry does not seem to affect the oxygen and carbon isotope values of α-cellulose from
Sphagnum fuscum peat significantly. There is, however, a (quasi-) constant offset between the isotope values of branches and stems and between whole plant material and α-cellulose, which makes it crucial to select single moss-fractions when past climate and environmental changes are to be derived from the isotope record.
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