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Indicators of maternal iron (Fe) status were studied in relation to placental Fe (Pl-Fe) status. Placental (Pl) and maternal (M) venous blood samples were obtained from primiparous women (n=38), with normal delivery at Paroissien Hospital, Argentina. Maternal hemoglobin (M Hb), soluble transferrin receptor (M sTfR) (ELISA) and serum ferritin (M S-Ft) were studied in relation to Pl-Fe, ferritin (Pl-Ft) and transferrin receptor (Pl-TfR). Pl-TfR was measured by dot blot assay, Pl-Ft and M S-Ft by immunoassay (IRMA) and Pl-Fe by atomic absorption spectrometry. Fe status indicators were, respectively, (mean±SD): M Hb 113±16 g/L; M S-Ft 36±42 μg/L; M sTfR 6.3±3.1 mg/L; Pl-Fe 170±56 μg/g placenta; Pl-Ft 33±18 μg/g placenta; Pl-TfR 18±18 (range 0–58) μg/g placenta. Pl-Fe, Pl-Ft and Pl-TfR did not correlate to M Hb, M S-Ft and M sTfR. Women with Pl- Fe, Pl-Ft and Pl-TfR above or below the corresponding median values did not show any statistical significant difference in M Hb, M sTfR or M S-Ft values. Pl-Ft concentration was lower in women with Hb<110 g/L than in women with normal values: 26±13 vs. 38±20 μg/g, respectively (p=0.021). When Pl-TfR, Pl-Ft and Pl-Fe were compared in women with M S-Ft above or below the cut-off point of 10 or 20 μg/L, no significant difference was found for Pl-TfR neither for Pl-Ft nor Pl-Fe. These results suggest that maternal indicators of Fe status, particularly M sTfR and M S-Ft, do not reflect Fe status of the placenta at delivery.  相似文献   

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The category "organism" has an ambiguous status: is it scientific or is it philosophical? Or, if one looks at it from within the relatively recent field or sub-field of philosophy of biology, is it a central, or at least legitimate category therein, or should it be dispensed with? In any case, it has long served as a kind of scientific bolstering for a philosophical train of argument which seeks to refute the mechanistic or reductionist trend, which has been perceived as dominant since the 17th century, whether in the case of Stahlian animism, Leibnizian monadology, the neo-vitalism of Hans Driesch, or, lastly, of the "phenomenology of organic life" in the 20th century, with authors such as Kurt Goldstein, Maurice Merleau-Ponty, and Georges Canguilhem. In this paper I try to reconstruct some of the main interpretive stages or layers of the concept of organism in order to evaluate it critically. How might organism be a useful concept if one rules out the excesses of organismic biology and metaphysics? Varieties of instrumentalism and what I call the projective concept of organism are appealing, but perhaps ultimately unsatisfying.  相似文献   

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BackgroundThis article reviews the salient features of recent results of clinical studies. It puts a special emphasis on technical aspects, mechanisms of action together with radiotherapy and chemotherapy and points out areas for additional investigation.AimTo present the current state of knowledge on hyperthermia (HT) and to highlight its role in the treatment of cervical cancer.Materials and methodsThe literature on the clinical use of combined hyperthermia for cervical cancer was analyzed. Clinical outcomes together with the technical aspects and the role of HT were also evaluated.ResultsClinically randomized trials have demonstrated benefit including survival with the addition of hyperthermia to radiation or chemotherapy in the treatment of cervical cancer without significant acute or late morbidities. The technological advances have led to an effective and safer treatment delivery, thermal treatment planning, thermal dose monitoring and online adaptive temperature modulation.ConclusionsDue to rapid development over the last decade of hyperthermia systems and new studies at the basic science and clinical level, the perception of hyperthermia as a part of multimodality treatment in cervical cancer has been changed. However, there is still a need for multicentre randomized clinical trials.  相似文献   

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ABSTRACT

Introduction: Extracellular vesicles (EVs) represent an important mode of intercellular communication. There is now a growing awareness that predominant EV subtypes; exosomes from endosomal origin, and shed microvesicles from plasma membrane budding, can be further stratified into distinct subtypes, however specific approaches in their isolation and markers that allow them to be discriminated are lacking.

Areas covered: Knowledge about these distinct EV subpopulations is important including the regulation of composition, release, targeting/localization, uptake, and function. This review discusses the mechanisms of distinct EV biogenesis and release, defining select EV classes (and subpopulations), which will be crucial for development of EV-based functions and clinical applications. We review the dynamics of cargo sorting leading to the mechanisms of EV heterogeneity, their mechanisms of formation, intracellular trafficking pathways, and provide an uptake about biochemical/functional differences. With advances in purification strategies and proteomic-based quantitation, allows significant benefit in accurately describing differences in EV protein cargo composition and modification.

Expert commentary: The advent of quantitative mass spectrometry-based proteomics, in conjunction with advances in molecular cell biology, and EV purification strategies, has contributed significantly to our improved characterization and understanding of the molecular composition and functionality of these distinct EV subpopulations.  相似文献   

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Menarche is an indicator frequently used to study variation in growth, development, and related health conditions among members of living populations. As a life event, menarche is often associated with changes in an individual's social identity. The reproductive lifespan, which for females starts with menarche, is a paramount feature of palaeodemographic studies. Determination of menarche status from the skeletal remains of individuals of past populations can be obtained by assessing the developmental status of the iliac crest, as well as the hand and wrist bones, which are, unlike teeth, often poorly recovered in bioarchaeological contexts. The present study seeks to evaluate the link between dental mineralization and menarche in a population of known menarche status. The relationship between permanent teeth mineralization and menarche status was investigated by using data of developing permanent teeth (167 radiographs) rated in accordance with the well‐known standards of Demirjian et al. and Moorrees et al. collected among 73 living French females of known menarcheal status. Using correlation ratios, GLMM and CART algorithm, menarcheal status is correlated with mineralization of the premolars. Menarcheal status is predicted correctly for 92 and 77% of radiographs of the learning and validation samples, respectively. Although promising, the results require caution prior to generalization to other populations. The age of menarche in this particular sample may simply coincide with the development of the premolars in this particular sample. Therefore, further investigation applied to populations with various mean ages of menarche is required in order to provide new evidence of variation in human growth and development from the correspondence between the mineralization of the permanent teeth and menarche.  相似文献   

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Summary Progress in rye karyology is reviewed with respect to chromosome structure, recognition and chromosome nomenclature. Considerable contributions have been brought about by molecular techniques which have even revealed nucleotide sequences of some of the ribosomal DNA. DNA sequence organization correlates with the distribution of major Giemsa C-band regions as well as with N-bands and the binding sites of fluorescent dyes. The several banding patterns permit the classification of rye chromosomes. The increased data and widespread application of banding analysis require a consistent system of chromosome and/or band designation. Therefore, a standard band nomenclature is proposed with reference to the recommendations of the Paris Conference on Standardization in Human Cytogenetics. In addition, advances in genetics are summarized and discussed. Based on the original accepted standard karyogram and banding patterns of the rye chromosomes, meanwhile, 120 genes determining several characters have been associated with individual chromosomes and/or chromosome arms, including linkage studies for about 19 arrangements. Most results were obtained using wheat-rye addition lines as well as test crosses with defined translocations. Moreover, genetical studies based on appropriate trisomic and telotrisomic material resulted in the localization of 19 genes, including their linkage relationships.  相似文献   

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Lipsmacking is performed by many Old World monkey species, and some studies of baboons and macaques suggest that lipsmacking may be associated with social status. We studied 60 adult anubis baboons (Papio cynocephalus anubis) for 18 months, measured social status and the rate of lipsmacking, and used these data to test the hypothesis that lipsmacking is related to social status. Our results indicate that social status and lipsmacking were not significantly correlated for either males or females. Analysis of lipsmacking in relation to social class (high vs. low) showed no significant difference between status classes for either sex. Lipsmacking was, however, found to be positively associated with affinitive behaviors. These results suggest that baboon lipsmacking provides positive social communication independently of social status.  相似文献   

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The most objectively substantiated health-related reason for tanning is that it improves vitamin D status. The serum 25-hydroxyvitamin D concentration (25(OH)D) is the measure of vitamin D nutrition status. Human biology was probably optimized through natural selection for a sun-rich environment that maintained serum 25(OH)D higher than 100 nmol/L. These levels are now only prevalent in people who spend an above-average amount of time outdoors, with the sun high in the sky. The best-characterized criteria for vitamin D adequacy are based on randomized clinical trials that show fracture prevention and preservation of bone mineral density. Based upon these studies, 25(OH)D concentrations should exceed 75 nmol/L. This concentration is near the upper end of the 25(OH)D reference ("normal") range for populations living in temperate climates, or for people who practice sun-avoidance, or who wear head coverings. Officially mandated nutrition guidelines restrict vitamin D intake from fortified food and supplements to less than 25 mcg/day, a dose objectively shown to raise serum 25(OH)D in adults by about 25 nmol/L. The combined effect of current nutrition guidelines and current sun-avoidance advice is to ensure that adults who follow these recommendations will have 25(OH)D concentrations lower than 75 nmol/L. Therefore, advice to avoid UVB light should be accompanied by encouragement to supplement with vitamin D in an amount that will correct for the nutrient deficit that sun-avoidance will cause.  相似文献   

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Biochemical assessment of growth hormone (GH) status is required in both suspected GH deficiency and GH excess. GH secretion can either be measured through investigation of the pituitary or by monitoring markers that change as a consequence of GH action on its target tissues. The two most widely used and, to date, best validated biochemical parameters are immunoassay measurement of either human GH (hGH) or insulin-like growth factor (IGF)-I. The fundamental difference between measurement of hGH and IGF-I is that the first reflects GH secretion while the second reflects GH action. However, because GH secretion is pulsatile in nature, random blood sampling for determination of hGH levels is only minimally informative. Analytical methods for measuring GH and IGF-I show considerable between-method variability. Since these parameters are used in establishing diagnoses and in monitoring GH-related diseases, the endocrinologist should be aware of the specifications and limitations of the analytical methods available.  相似文献   

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This article provides theoretical grounds and empirical evidence that different types of lynching in the post-Reconstruction South were driven by social processes at different levels of analysis. County-level analyses based upon new detailed data on lynchings in Georgia and Louisiana from 1882 to 1930 reveal that ‘private' lynchings, perpetrated by small groups outside the public purview without manifest ritual, were related to whites’ interracial status and social identity concerns on the interpersonal level, whereas ‘public' lynchings, involving larger mobs and ritualized violence, appear unaffected by such dynamics. These results validate relational and interactionist perspectives on violence, lend support to calls for disaggregation in the study of racial, ethnic, and nationalist violence, and shed light on the intertwining of racial identity formation with the generation of racial inequalities. They also carry implications for the study of contemporary ethno-racial hate crime.  相似文献   

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Semen from Barbary sheep (Ammotragus lervia), Bighorn sheep (Ovis canadensis), Mouflon sheep (Ovis musimon), Fallow deer (Dama dama), collected by electroejaculation, and semen from Wildebeest antelope (Connochaetes taurinus), collected post mortem, were frozen using a standardized technique and a commercial freezing medium (Triladyl). Sperm quality was assessed by measuring their capacitation status (chlortetracycline assay) in addition to classic assessment: motility, viability (plasma membrane integrity), and acrosome integrity. Sperm cryosurvival measured in terms of recovery (from the initial, pre-freeze values) of motility, viability, and acrosome integrity was relatively high in most species. However, proportion of premature-capacitated spermatozoa (B + AR patterns) increased many times in relation to that of fresh semen: from 8% to 78% in Barbary sheep; from 27% to 61% in Bighorn sheep; and from 12% to 68% in Mouflon sheep. The use of a standardized technique for freezing of spermatozoa from wild ruminant species produced, in most of the cases, acceptable results. This approach may be extensively used to carry out sperm cryopreservation in field conditions. Chlortetracycline assay allowed identifying the same fluorescent patterns observed in spermatozoa from domestic animals and produced additional information on sperm cryosurvival. That is, it revealed those cells that survive freeze–thawing and are potentially fertile: non-capacitated (F pattern) and capacitated acrosome-intact spermatozoa (B pattern).  相似文献   

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