Gas exchange in young Scots pine following pruning of current shoots

A pine shoot beetle attack was simulated by cutting all current shoots in the upper crown of 2 20-yr-old Scots pines (Pinus sylvestris L) while gas exchange was followed continuously before and after the shoot removal. Net photosynthetic rate and mesophyll conductance of the 2-yr-old shoots decreased by = 50% immediately after pruning but recovered within 10 d after the shoot removal. The quantum yield was also much lower after cutting. Water status and transpiration rate were not systematically affected by the treatment. Possible explanations of the photosynthetic decrease could be an accumulation of assimilation products decreasing the mesophyll conductance of carbon dioxide to the chloroplasts or changes of the carbon allocation pattern.Échanges gazeux chez des jeunes pins sylvestres après élagage des pousses de l'année. Une attaque du scolytide Tomicus piniperda a été simulée en coupant toutes les pousses de l'année dans la partie supérieure de la couronne de 2 pins sylvestres (Pinus sylvestris L) de 20 ans. Pendant le même temps, les échanges gazeux ont été suivis de façon continue avant et après l'opération. Le taux net de photosynthèse et la conductance du mésophylle des pousses de un an décroît d'environ 50% immédiatement après l'élagage, mais récupère dans les 10 jours suivant le retrait des pousses. Le rendement quantique diminue aussi beaucoup après la coupe des pousses. L'état hydrique et le taux de transpiration ne sont pas affectés systématiquement par le traitement. La diminution de la photosynthèse pourrait être expliquée par une accumulation d'assimilats ayant pour effet de diminuer la conductance du mésophylle pour le dioxyde de carbone vers les chloroplastes ou par des modifications dans le shéma d'allocation du carbone

Increased synthesis of dopamine in prefrontal cortex and striatum in drug-naive schizophrenic patients studied by use of 11C-labelled L-dopamine and positron emission tomography

The present study was design to test the hypothesis of a deviant dopaminergic activity in schizophrenia by using the positron emission tomography (PET) technique (GE 2048-15B Plus camera) and 11C-labelled L-DOPA as the tracer, which enables calculation of the rate of synthesis (‘utilization’) of dopamine in different brain regions. Twelve first-admitted and never-treated patients with a DSM-IV diagnosis of schizophrenia (10 men and 2 women) were included. Their mean age was 31.6 years. Controls were 10 healthy volunteers (8 male and 2 female) with a mean age of 33 years. Scanning began immediately after injection of 11C-L-DOPA and continued for 60 min. A patlak plot was calculated for each individual, giving the K3 value, which indirectly reflects the enzymatic utilization of L-DOPA and indirectly the synthesis rate for dopamine. The data showed no lateralization for any brain region tested, either in controls or in schizophrenic patients. However, when compared with healthy controls, a significantly increased synthesis of dopamine was found in the putamen (K3, 1.75 versus 1.59, P = 0.01) and in the caudatus (K3, 1.72 versus 1.50, P=0.002). Further, a significantly increased K3 was also seen in the medial prefrontal cortex in schizophrenic patients (K3, 0.84 versus 0.70, P=0.014). The present results indicate an increased synthesis of dopamine in certain brain areas, most interestingly in the frontal lobe, in schizophrenia

Improving the diagnosis and management of neuroendocrine tumors: Utilizing new advances in biomarker and molecular imaging science

Neuroendocrine tumors (NET) are malignant solid tumors that arise in hormone-secreting tissue of the diffuse neuroendocrine system or endocrine glands. Although traditionally understood to be a rare disease, the incidence and prevalence of NET have increased greatly in the past 3 decades. However, during this time, progress in diagnosis and outcome of NET has generally been modest. In order to achieve improved outcome in NET, a better understanding of NET biology combined with more reliable serum markers and better techniques to identify tumor localization and small lesions are needed. Although some NET biomarkers exist, sensitive and specific markers that predict tumor growth and behavior are generally lacking. In addition, the integration of new molecular imaging technologies in patient diagnosis and follow-up has the potential to enhance care. To discuss developments and issues required to improve diagnostics and management of NET patients, with specific focus on the latest advances in molecular imaging and biomarker science, 17 global leaders in the fields of NET, molecular imaging and biomarker technology gathered to participate in a 2-day meeting hosted by Prof. Kjell Oberg at the University of Uppsala in Sweden. During this time, findings were presented regarding methods with potential prognostic and treatment applications in NET or other types of cancers. This paper describes the symposium presentations and resulting discussions