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81.
Somatostatin receptors type 2 (sst(2)) are expressed in high concentration on numerous neudoendocrine tumors. The successful use of radiolabeled somatostatin analogs in imaging promoted further studies in utilizing them in radiopeptide therapy. The somatostatin analog [(90)Y-DOTA-D-Phe(1)-Try3]octreotide (DOTATOC) (DOTA: 1,4,7,10-tetraazacyclododecane-N,N',N',N'-tetraacetic acid) possesses favorable characteristic for its therapeutic use; shows high affinity for sst(2), moderately high affinity for sst(5), and intermediate affinity for sst(3); high hydrophilicity; stable and facile labeling with (111) In and (90) Y. In this article we report our experience with (90)Y-DOTATOC in neuroendocrine tumors. Eighty-seven patients with neuroendocrine tumors were treated with a cumulated activity ranging from 7.4 to 20.2 GBq. Most patients responded with stabilization of disease (48%); however, objective responses were observed in 28% of patients (5% complete response). No major acute reactions were observed up to the activity of 5.55 GBq per cycle. The dose limiting was bone marrow toxicity and the maximal tolerated dose was defined as 5.18 GBq.  相似文献   
82.
Summary Frequency distributions of egg mass for more than 3000 species each of passerine and non-passerine birds derived from the tables ofSchönwetter are lognormal in form.
Häufigkeitsverteilung der Eimassen nach den Angaben in den Tabellen vonSchönwetter
Zusammenfassung Die Häufigkeiten der Eimassen von jeweils über 3000 Arten der Singvögel und Nichtsingvögel aus den Tabellen im Handbuch vonSchönwetter sind lognormal verteilt (vgl. Abb.).
  相似文献   
83.
The asymmetric hydroformylation reaction represents a potential powerful synthetic tool for the preparation of large number of different chiral products to be used as precursors of several organic compounds endowed with therapeutic activity. Essential and nonessential amino acids, 2-arylpropanoic acids, aryloxypropyl- and beta-phenylpropylamines, modified beta-phenylethylamines, pheniramines, and other classes of pharmaceuticals are available through enantioselective oxo-reaction of appropriate functionalized olefins; this process is catalyzed by rhodium or platinum complexes with chiral ligands, mainly chelating phosphines, and sometimes affords very high enantiomeric excesses. Furthermore, the application of many simple optically active aldehydes arising from asymmetric hydroformylation as chiral building blocks for the synthesis of complex pharmacologically active molecules such as antibiotics, peptides, antitumor macrocycle compounds, and prostaglandins is conveniently emphasized. The possibility of a future application of this asymmetric process for the production of many synthons to obtain other valuable pharmaceuticals is widely discussed too.  相似文献   
84.
Apoptosis plays a major role during HIV infection, including the primary, acute HIV syndrome (AHS), during which such phenomenon is massive. We asked whether apoptosis involved not only peripheral blood lymphocytes, but also monocytes (PBM) and granulocytes (PBG). Thus, we studied cells from different patients during the acute phase of the viral syndrome. The CD95 molecule was expressed at high density on the PBM and PBG surface during AHS. Culturing PBG for a few hours resulted in a significant membrane expression of phosphatidylserine, consistent with apoptosis. However, cells maintained for hours plasma membrane integrity and showed no relevant changes in mitochondrial membrane potential. The overexpression of CD95 was not associated with high plasmatic levels of sCD95 and, together with apoptosis and its related markers decreased after a few weeks of highly active antiretroviral therapy. During AHS, a deregulation of the CD95 system occurs in monocytes and granulocytes, is related to a high propensity of PBG to undergo apoptosis, and may contribute to the pathogenesis of the disease. Antiretroviral treatment resulted not only in a decrease of virus production, but also in a reduced PBG tendency to undergo spontaneous apoptosis. Even if the mechanism(s) responsible for this phenomenon remains to be elucidated, our data suggest a possible (indirect?) action of antiretroviral therapies on PBG and PBM which could explain, at least partially, the rescue of natural immunity and the reduced use of granulocyte-colony stimulating factor during such treatments.  相似文献   
85.
The presence of predators can induce changes in both the morphology and behaviour of Anuran larvae, affecting both their size and developmental stage at metamorphosis and, consequently, the fitness of adult individuals. Tadpoles have been shown to be capable of finely tuning their defensive responses according to the actual risk perceived, which is expected to vary according to the prey-to-predator size ratio. In this study, we exposed common frog (Rana temporaria) tadpoles (Gosner stages 28–30), for a period of 2 weeks, to the non-lethal presence of dragonfly larvae (Anax imperator) and backswimmers (Notonecta glauca). In such a narrow window of time, we expected behavioural responses to be similar for both predators and exposure to predation risk to have negligible effects on tadpole development and weight. Overall, tadpoles increased hiding behaviour and were less active when predators were present in the experimental mesocosms, but behavioural responses were constrained to the early phase of the ontogeny and were no longer used when tadpoles reached a threshold size. Developmental rate slightly slowed down for predator treatments in comparison to controls, possibly as a consequence of energetic investment in unrecorded morphological defences. Although variation in laboratory conditions and protocols makes it hard to compare the results of different experiments, our results contribute to verify the consistency of behavioural responses in Anuran larvae.  相似文献   
86.
Mites occurring on a number ofnatural and secondary (i.e., planted) hedgerowslocated in north-eastern Italy were monitoredwith particular attention being paid tophytoseiids (Acari: Phytoseiidae). Pollendiversity and abundance were analysed tohighlight potential relationships betweenpollen availability and phytoseiids. Secondaryhedgerows were structured in modules containinga single species (field maple, hornbeam,dogwood, hazel, and elderberry) andmodules containing a mixture of theabove-mentioned species. These hedgerows werelocated in an experimental farm where they werecontiguous to a vineyard. Natural hedgerowswere located in the same area. The pollen ofPoaceae was the most important component ofnon-arboreal pollen (NAP), and that ofelderberry of arboreal pollen (AP). Pollendiversity was higher on natural than onsecondary hedgerows. Generally, pollendensities reached relatively high levels fromlate April to late June and decreased insummer. Pollen was more abundant on naturalthan on secondary hedgerows and phytoseiidabundance showed a similar trend. On elderberryand hornbeam in natural hedgerows a potentialrelationship between pollen availability andthe abundance of phytoseiids, in particular ofEuseius finlandicus (Oudemans) was found.Experimental pollen applications increased thefecundity and the abundance of this species.  相似文献   
87.
Extracellular vesicles (EV) can transfer cellular molecules for specific intercellular communication with potential relevance in pathological conditions. We searched for the presence in plasma from coronary artery disease (CAD) patients of EV containing the adenosine A2A receptor (A2AR), a signalling receptor associated with myocardial ischaemia and whose expression is related to homocysteine (HCy) metabolism. Using protein organic solvent precipitation for plasma EV preparation and Western blotting for protein identification, we found that plasma from CAD patients contained various amounts of EV with ubiquitin bound to A2AR. Interestingly, the presence of ubiquitinated A2AR in EV from patients was dependent on hyperhomocysteinemia, the amount being inversely proportional to A2AR expression in peripheral mononuclear cells in patients with the highest levels of HCy. CEM, a human T cell line, was also found to released EV containing various amounts of ubiquitinated A2AR in stimulated conditions depending on the hypoxic status and HCy level of culture medium. Together, these data show that ubiquitinated A2AR‐containing EV circulate in the plasma of CAD patients and that this presence is related to hyperhomocysteinemia. A2AR in plasma EV could be a useful tool for diagnosis and a promising drug for the treatment of CAD.  相似文献   
88.
1. Late prenatal chicken embryos in eggs injected with saline showed a feeble homeothermic metabolic response to gradual cooling. This response was absent in thiourea-treated eggs. This suggests that the incipient homeothermic metabolic response before paranatal life may be attributed to thyroid development. 2. The compensatory metabolic response disappeared in embryos exposed to a hypoxic environment, while it was augmented in eggs in pure O2, decreasing as ambient temperature fell. 3. These results may indicate that the homeothermic metabolic response in late embryos is O2-conductance-limited and power-limited as previously suggested.  相似文献   
89.
Umbilical cord matrix stem cells (UCMSC) have generated great interest in various therapeutic approaches, including liver regeneration. This article aims to analyze the specific characteristics and the potential occurrence of premalignant alterations of UCMSC during long-term expansion, which are important issues for clinical applications. UCMSC were isolated from the umbilical cord of 14 full-term newborns and expanded in vitro until senescence. We examined the long-term growth potential, senescence characteristics, immunophenotype and multilineage differentiation capacity of these cells. In addition, their genetic stability was assessed through karyotyping, telomerase maintenance mechanisms and analysis of expression and functionality of cell cycle regulation genes. The tumorigenic potential was also studied in immunocompromised mice. In vitro, UCMSC reached up to 33.7±2.1 cumulative population doublings before entering replicative senescence. Their immunophenotype and differentiation potential, notably into hepatocyte-like cells, remained stable over time. Cytogenetic analyses did not reveal any chromosomal abnormality and the expression of oncogenes was not induced. Telomere maintenance mechanisms were not activated. Just as UCMSC lacked transformed features in vitro, they could not give rise to tumors in vivo. UCMSC could be expanded in long-term cultures while maintaining stable genetic features and endodermal differentiation potential. UCMSC therefore represent safe candidates for liver regenerative medicine.  相似文献   
90.
Hyperhomocysteinemia is associated with coronary artery disease (CAD). The mechanistic aspects of this relationship are unclear. In CAD patients, homocysteine (HCy) concentration correlates with plasma level of adenosine that controls the coronary circulation via the activation of adenosine A2A receptors (A2AR). We addressed in CAD patients the relationship between HCy and A2AR production, and in cellulo the effect of HCy on A2AR function. 46 patients with CAD and 20 control healthy subjects were included. We evaluated A2AR production by peripheral blood mononuclear cells using Western blotting. We studied in cellulo (CEM human T cells) the effect of HCy on A2A R production as well as on basal and stimulated cAMP production following A2A R activation by an agonist‐like monoclonal antibody. HCy concentration was higher in CAD patients vs controls (median, range: 16.6 [7‐45] vs 8 [5‐12] µM, P < 0.001). A2A R production was lower in patients vs controls (1.1[0.62‐1.6] vs 1.53[0.7‐1.9] arbitrary units, P < 0.001). We observed a negative correlation between HCy concentration and A2A R production (r = ?0.43; P < 0.0001), with decreased A2A R production above 25 µM HCy. In cellulo, HCy inhibited A2AR production, as well as basal and stimulated cAMP production. In conclusion, HCy is negatively associated with A2A R production in CAD patients, as well as with A2A R and cAMP production in cellulo. The decrease in A2A R production and function, which is known to hamper coronary blood flow and promote inflammation, may support CAD pathogenesis.  相似文献   
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