Long-term decline of the Amazon carbon sink

Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

Diethylnitrosamine (DEN)-induced carcinogenic liver injury in mice

The toxic properties of various nitrosamines in animals and humans are well established. The parenteral or oral administration of the smallest quantities of diethylnitrosamine (DEN) or dimethylnitrosamine (DMN) results in severe liver damage. Most prominent are intense neutrophilic infiltration, extensive centrilobular haemorrhagic necrosis, bile duct proliferation, fibrosis, and bridging necrosis that ends in hepatocarcinogenesis. Due to the robustness of the induced hepatic alterations, the application of DEN in rodents has become an attractive experimental model for studies aimed at understanding the pathogenetic alterations underlying the formation of liver cancer, which represents one of the most common malignancies in humans worldwide. However, several studies have shown that the hepatocarcinogenic effects of nitrosamines might vary with the genetic background of the animals, their sex, their age, and other factors that might impact the outcome of experimentation. We present general guidelines for working with DEN, and a detailed protocol that allows the establishment of highly reproducible liver cancer in mice. The outcome of liver injury after the application of DEN in mice, as estimated by the formation of cirrhosis and cancer, appears to be a suitable animal model for the analysis of some aspects and processes that promote the pathogenesis of hepatocellular carcinoma in humans.

Intended follow up of women with breast cancer at low risk of recurrence and at least 5 years from diagnosis

BACKGROUND

Although there is evidence that minimal surveillance is compatible with an optimal outcome in women after early stage breast cancer, little is known of the surveillance that these women receive.

AIMS

To describe the intended clinical follow up and patterns of use of imaging modalities in low-risk breast cancer survivors who are at least 5 years from diagnosis.

METHODS

Participants in the Bupa Health Foundation Health and Wellbeing After Breast Cancer Study with stage 1 invasive breast cancer at diagnosis, who had survived free of recurrence or new primary breast cancer for at least 5 years, provided information for this analysis.

RESULTS

The most common choice of physician follow up was with one doctor only (54%). Within this group, the most frequent choice was a general practitioner (GP) (63%) followed by medical oncologist (23%). Thirty-five per cent of women said that they intended to consult two doctors and within this group, the most common combination was a GP and a medical oncologist (45%). This was despite two out of three women reporting being advised that there was no need to consult a medical oncologist. Over 90% of women reported having a mammogram with, or without, breast ultrasound in the previous 12 months. There was a low rate of use of other imaging tests in the absence of clear indications.

CONCLUSIONS

Minimising unnecessary medical consultations by women with breast cancer at low risk of recurrence 5 years from diagnosis will require education about the benefits of a minimal surveillance strategy.

Mechanism and functional impact of CD40 ligand-induced von Willebrand factor release from endothelial cells

Co-stimulation via CD154 binding to CD40, pivotal for both innate and adaptive immunity, may also link haemostasis to vascular remodelling. Here we demonstrate that human platelet-bound or recombinant soluble CD154 (sCD154) elicit the release from and tethering of ultra-large (UL) von Willebrand factor (vWF) multimers to the surface of human cultured endothelial cells (ECs) exposed to shear stress. This CD40-mediated ULVWF multimer release from the Weibel-Palade bodies was triggered by consecutive activation of TRAF6, the tyrosine kinase c-Src and phospholipase Cγ1 followed by inositol-1,4,5 trisphosphate-mediated calcium mobilisation. Subsequent exposure to human washed platelets caused ULVWF multimer-platelet string formation on the EC surface in a shear stress-dependent manner. Platelets tethered to these ULVWF multimers exhibited P-selectin on their surface and captured labelled monocytes from the superfusate. When exposed to shear stress and sCD154, native ECs from wild-type but not CD40 or vWF-deficient mice revealed a comparable release of ULVWF multimers to which murine washed platelets rapidly adhered, turning P-selectin-positive and subsequently capturing monocytes from the perfusate. This novel CD154-provoked ULVWF multimer-platelet string formation at normal to fast flow may contribute to vascular remodelling processes requiring the perivascular or intravascular accumulation of pro-inflammatory macrophages such as arteriogenesis or atherosclerosis.

Effectivity of long antigen exposition dendritic cell therapy (LANEXDC®) in the palliative treatment of pancreatic cancer

PURPOSE

In pancreatic cancer median survival times range around 6, 6 to 6,9 months. Here we retrospectively analyzed the outcome of immunotherapy in the additional palliative treatment of pancreatic cancer with long antigen exposition dendritic cell therapy (LANEX-DC(®)) in 138 patients who were treated at our institution.

PATIENTS

Data were available of 134 patients (97.1%). The median interval between first diagnosis and start of treatment was 1.4 months.

RESULTS

Therapy was well tolerated and no serious side effects were observed. The survival rate after 6 months was 72.2 % and afters 9 month 50.4%. The median survival time according to Kaplan- Meier regression analysis was 8.9 months. Median survival was significantly higher in the group of patients who started immunotherapy within 2 months following diagnosis (p=0.029) or repeated immunotherapy (p=0.027). Interestingly, younger patients <= 60 years of age lived significantly longer as patients > 60 years of age (p = 0.022).

CONCLUSION

We were able to demonstrate in a large retrospective analysis that additional treatment with dendritic cells (LANEX-DC(®)) is highly effective and extends the median survival times up to 8.9 months. Furthermore we were able to demonstrate that median survival can be increased by early beginning and repetition of LANEX-DC(®) treatment.

[Immunological treatment options for schizophrenia]

The pathophysiological mechanism leading to dopaminergic dysfunction in schizophrenia is still unclear. Inflammation seems to play a key role. A dysfunction in the activation of the type 1 immune response is associated with decreased activity of the key enzyme of the tryptophan/kynurenine metabolism, indolamine-2.3-dioxygenase (IDO), results in a higher production of kynurenine acid (KYNA)--an N-methyl-D-aspartate antagonist--in the central nervous system (CNS) and decreased glutamatergic neurotransmission. The differential activation of microglial cells and astrocytes, which serve as immune cells in the CNS, contributes to the TH1-TH2 immune imbalance. Antipsychotics, all acting as dopamine D2 receptor antagonists show several shortcomings. The immune effects of antipsychotics rebalance partly the imbalance of the type-1/type-2 immune response and the overproduction of KYNA. The inflammation is associated with higher prostaglandin E2 (PGE2) production and higher cyclo-oxygenase-2 (COX-2) expression. Increasing evidence from clinical studies with COX-2 inhibitors points to an advantageous effect of anti-inflammatory therapy in schizophrenia, especially in the early stages of the disease. Further options of immunomodulatory therapy in schizophrenia are discussed.

Endothelialization of electrospun polycaprolactone (PCL) small caliber vascular grafts spun from different polymer blends

Small caliber vascular grafts represent a challenge to material scientists. In contrast to large caliber grafts, prostheses with diameter <6 mm, lead to increased hemodynamic disturbances and thrombogenic complications. Thus, endothelialization of small caliber grafts should create a compatible interface for hemodynamic processes. The purpose of our study was to compare different compositions of electrospun scaffolds with conventional ePTFE grafts with an inner diameter of 4 mm as well as different pre-coatings to create an optimized physiological interface for endothelialization. Polycaprolactone, polylactide, and polyethylenglycol (PCL/PLA and PCL/PLA/PEG) electrospun grafts and ePTFE grafts were pre-coated with blood, gelatine or fibronectin and seeded with endothelial cells from the human term placenta. Best results were obtained with fibronectin-coated PCL/PLA/PEG grafts. Here, the number of attached viable cells was 78-81% higher than on fibronectin pre-treated ePTFE grafts. Cells attached to PCL/PLA/PEG grafts appeared in physiological cobblestone morphology. Viability analysis showed a high cell viability of more than 98%. Fibronectin-coated PCL/PLA/PEG grafts may be a promising improvement to conventionally used ePTFE grafts.