168 research outputs found
Heterogeneity of mouse spleen dendritic cells: in vivo phagocytic activity, expression of macrophage markers, and subpopulation turnover
In the normal mouse spleen, two distinct populations of dendritic cells
(DC) are present that differ in microanatomical location. The major
population of marginal DC is found in the "marginal zone bridging
channels" and extends into the red pulp. The interdigitating cells (IDC)
are localized in the T cell areas in the white pulp. The aim of the
present study was to characterize these two splenic DC populations with
regard to their phenotype, in vivo phagocytic function, and turnover. Both
marginal DC and IDC are CD11c+ and CD13+, but only IDC are NLDC-145+ and
CD8alpha+. Notably, both populations, when freshly isolated, express the
macrophage markers F4/80, BM8, and Mac-1. To study the phagocytic capacity
of these cells, we employed the macrophage "suicide" technique by
injecting liposomes loaded with clodronate i.v. Marginal DC, but not IDC,
were eliminated by this treatment. Phagocytosis of DiI-labeled liposomes
by DC confirmed this finding. The two DC populations differed
significantly with regard to their turnover rates, as studied in a
transgenic mouse model of conditional depletion of DC populations with
high turnover. In these mice, marginal DC were completely eliminated, but
the IDC population remained virtually intact. From these data we conclude
that the marginal DC population has a high turnover, in contrast to the
IDC population. Taken together, the present results indicate that marginal
DC and IDC represent two essentially distinct populations of DC in the
mouse spleen. They differ not only in location, but also in phenotype,
phagocytic ability, and turnover
Heterogeneity of mouse spleen dentritic cells: in vivo phagocytic activity, expression of macrophage markers, and subpopulation turnover
Heterogeneity of mouse spleen dentritic cells: in vivo phagocytic activity, expression of macrophage markers, and subpopulation turnover
A Business Process Improvement framework for Knowledge-Intensive Entrepreneurial Ventures
Pushed by the transition towards the knowledge economy, as well as several other change drivers, an ever-increasing number of knowledge intensive ventures are relying on operational knowledge intensity in order to generate value. Through their interaction with their varied stakeholders -- from actors within their supply chains to educational and financial institutions -- knowledge intensive enterprises are increasingly becoming a key component of regional economic stability. Within their complex environment, these organisations lack the support of suitable frameworks to inform their efforts to optimise, adapt and improve their underlying business processes in order to maximise the efficiency of their performance and pursue growth ambitions. This paper examines the distinct nature of knowledge intensive entrepreneurial ventures (KIEs) and the applicability of current Business Process Improvement (BPI) frameworks to their setting. Finally, a KIE-oriented business process improvement framework is developed through an integrative adaptation of the concepts of knowledge intensity and knowledge management to the principles of business process redesign and re-engineering reported in existing literature. The proposed framework contributes to the existing literature in the subject of BPI modelling for knowledge intensive entrepreneurial ventures by addressing a distinct set of improvement concerns that this type of organisations face at a process level
Heterogeneity of mouse spleen dentritic cells: in vivo phagocytic activity, expression of macrophage markers, and subpopulation turnover
Network structure and taxonomic composition of tritrophic communities of Fagaceae, cynipid gallwasps and parasitoids in Sichuan, China
A key question in insect community ecology is whether parasitoid assemblages are structured by the food plants of their herbivore hosts. Tritrophic communities centred on oak-feeding cynipid gallwasps are one of the best-studied tritrophic insect communities. Previous work suggests that host plant identity is a much stronger predictor of oak–cynipid interactions than of cynipid–parasitoid interactions. However, these relationships have not been formally quantified. We reason that the potential for ‘bottom-up’ effects should increase with host plant phylogenetic diversity. We, therefore, generated quantified interaction network data for previously unstudied tritrophic cynipid communities in Sichuan, China, where, in addition to Quercus, cynipid host plants include Castanea, Castanopsis and Lithocarpus. We characterise these communities taxonomically and compare the extent to which host plant taxonomy predicts plant–herbivore and plant–parasitoid associations. We sampled 42,620 cynipid galls of 176 morphotypes from 23 host plant species, yielding over 4500 specimens of 64 parasitoid morphospecies. Many parasitoids were identifiable to chalcidoid taxa present in other Holarctic oak cynipid communities, with the addition of Cynipencyrtus (Cynipencyrtidae). As elsewhere, Sichuan parasitoid assemblages were dominated by generalists. Gallwasp–plant interaction networks were significantly more modular than parasitoid–plant association networks. Gallwasps were significantly more specialised to host plants (i.e. had higher mean d' values) than parasitoids. Parasitoid assemblages nevertheless showed significant plant-associated beta diversity, with a dominant turnover component. We summarise parallels between our study and other Fagaceae-associated cynipid communities and discuss our findings in light of the processes thought to structure tritrophic interactions centred on endophytic insect herbivores
Network structure and taxonomic composition of tritrophic communities of Fagaceae, cynipid gallwasps and parasitoids in Sichuan, China
A key question in insect community ecology is whether parasitoid assemblages are structured by the food plants of their herbivore hosts. Tritrophic communities centred on oak‐feeding cynipid gallwasps are one of the best‐studied tritrophic insect communities. Previous work suggests that host plant identity is a much stronger predictor of oak–cynipid interactions than of cynipid–parasitoid interactions. However, these relationships have not been formally quantified. We reason that the potential for ‘bottom‐up’ effects should increase with host plant phylogenetic diversity. We, therefore, generated quantified interaction network data for previously unstudied tritrophic cynipid communities in Sichuan, China, where, in addition to Quercus, cynipid host plants include Castanea, Castanopsis and Lithocarpus. We characterise these communities taxonomically and compare the extent to which host plant taxonomy predicts plant–herbivore and plant–parasitoid associations. We sampled 42,620 cynipid galls of 176 morphotypes from 23 host plant species, yielding over 4500 specimens of 64 parasitoid morphospecies. Many parasitoids were identifiable to chalcidoid taxa present in other Holarctic oak cynipid communities, with the addition of Cynipencyrtus (Cynipencyrtidae). As elsewhere, Sichuan parasitoid assemblages were dominated by generalists. Gallwasp–plant interaction networks were significantly more modular than parasitoid–plant association networks. Gallwasps were significantly more specialised to host plants (i.e. had higher mean d' values) than parasitoids. Parasitoid assemblages nevertheless showed significant plant‐associated beta diversity, with a dominant turnover component. We summarise parallels between our study and other Fagaceae‐associated cynipid communities and discuss our findings in light of the processes thought to structure tritrophic interactions centred on endophytic insect herbivores
Network structure and taxonomic composition of tritrophic communities of Fagaceae, cynipid gallwasps and parasitoids in Sichuan, China
A key question in insect community ecology is whether parasitoid assemblages are structured by the food plants of their herbivore hosts. Tritrophic communities centred on oak‐feeding cynipid gallwasps are one of the best‐studied tritrophic insect communities. Previous work suggests that host plant identity is a much stronger predictor of oak–cynipid interactions than of cynipid–parasitoid interactions. However, these relationships have not been formally quantified. We reason that the potential for ‘bottom‐up’ effects should increase with host plant phylogenetic diversity. We, therefore, generated quantified interaction network data for previously unstudied tritrophic cynipid communities in Sichuan, China, where, in addition to Quercus, cynipid host plants include Castanea, Castanopsis and Lithocarpus. We characterise these communities taxonomically and compare the extent to which host plant taxonomy predicts plant–herbivore and plant–parasitoid associations. We sampled 42,620 cynipid galls of 176 morphotypes from 23 host plant species, yielding over 4500 specimens of 64 parasitoid morphospecies. Many parasitoids were identifiable to chalcidoid taxa present in other Holarctic oak cynipid communities, with the addition of Cynipencyrtus (Cynipencyrtidae). As elsewhere, Sichuan parasitoid assemblages were dominated by generalists. Gallwasp–plant interaction networks were significantly more modular than parasitoid–plant association networks. Gallwasps were significantly more specialised to host plants (i.e. had higher mean d' values) than parasitoids. Parasitoid assemblages nevertheless showed significant plant‐associated beta diversity, with a dominant turnover component. We summarise parallels between our study and other Fagaceae‐associated cynipid communities and discuss our findings in light of the processes thought to structure tritrophic interactions centred on endophytic insect herbivores
Metastatic gallbladder adenocarcinoma with signet-ring cells: A case report
<p>Abstract</p> <p>Introduction</p> <p>Signet-ring cell carcinoma is a rare and aggressive variant of mucinous adenocarcinoma. Only a few cases of gallbladder adenocarcinoma with signet-ring cells have been reported and because of this there is a lack of knowledge about the behavior and biology of this pathology.</p> <p>Case presentation</p> <p>We present the case of a 63-year-old Arab man with gallbladder signet-ring cell adenocarcinoma. He had an elective cholecystectomy and refused chemotherapy. Two months later, a small hepatic metastatic nodule was found, and nine months later he presented with multiple metastases in the liver, lymphatic nodes, both pleuras, peritoneum and subcutaneous tissue.</p> <p>Conclusion</p> <p>The proliferation of signet-ring cells in a gallbladder adenocarcinoma worsens the prognosis of an already adverse neoplasm. New lines of treatment in chemotherapy, such as cisplatin, or new biological therapy, such as monoclonal antibody c-myc oncogene, should be encouraged to improve the survival and life quality of these oncologic patients.</p
Increased blood pressure in adult offspring of families with Balkan Endemic Nephropathy: a prospective study
BACKGROUND: Previous studies have linked smaller kidney dimensions to increased blood pressure. However, patients with Balkan Endemic Nephropathy (BEN), whose kidneys shrink during the course of the disease, do not manifest increased blood pressure. The authors evaluated the relationship between kidney cortex width, kidney length, and blood pressure in the offspring of BEN patients and controls. METHODS: 102 offspring of BEN patients and 99 control offspring of non-BEN hospital patients in the Vratza District, Bulgaria, were enrolled in a prospective study and examined twice (2003/04 and 2004/05). Kidney dimensions were determined using ultrasound, blood pressure was measured, and medical information was collected. The parental disease of BEN was categorized into three groups: mother, father, or both parents. Repeated measurements were analyzed with mixed regression models. RESULTS: In all participants, a decrease in minimal kidney cortex width of 1 mm was related to an increase in systolic blood pressure of 1.4 mm Hg (p = 0.005). There was no association between kidney length and blood pressure. A maternal history of BEN was associated with an increase in systolic blood pressure of 6.7 mm Hg (p = 0.03); paternal BEN, +3.2 mm Hg (p = 0.35); or both parents affected, +9.9 mm Hg (p = 0.002). There was a similar relation of kidney cortex width and parental history of BEN with pulse pressure; however, no association with diastolic blood pressure was found. CONCLUSION: In BEN and control offspring, a smaller kidney cortex width predisposed to higher blood pressure. Unexpectedly, a maternal history of BEN was associated with average increased systolic blood pressure in offspring
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