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51.
Preoteasa CT Ionescu E Didilescu AC Meleşcanu-Imre M Bencze MA Preoteasa E 《Revue roumaine de morphologie et embryologie》2011,52(3):937-941
Like any other medical intervention, the orthodontic treatment may have, besides the positive effects, also unwanted secondary consequences. The aim of this study was to evaluate the changes present in dental hard tissue associated with orthodontic treatment. The stereo-microscopic ex vivo analysis was performed on two sets of maxillary first premolars undergoing orthodontic treatment for a long period of time (12 and 23 months); five teeth with other clinical situations were used as controls. By analyzing the teeth undergoing orthodontics, enamel color alterations were mainly found adjacent to the bracket, more pronounced in the gingival area, suggesting the need for a correct oral hygiene around it. Roughness was higher on the enamel surface corresponding to the bracket's base, aspect linked to the resign impregnation during bonding procedures. At the apical part, changes regarding contour, appearance and surface roughness were noticed. These modifications were suggestive for the presence of apical root resorption. The severity of root resorption was not correlated with the duration of treatment. In conclusion, through microscopic analysis changes that may be associated with orthodontic treatment have been observed in both crown and apical level. 相似文献
52.
Pharmacological manipulation of both dopamine and glutamate systems affects motor responses in laboratory animals. The two systems, however, seem to act in opposite ways, since direct or indirect activation of dopamine receptors induces similar stimulatory effects to those seen following blockade of N-methyl-D-aspartate receptors. In the present study we compared the pattern of c-fos activation induced by systemic and intra-accumbens administration of the non-competitive N-methyl-D-aspartate antagonist MK-801 and the indirect dopamine agonist amphetamine. Systemic MK-801 induced c-fos mRNA expression in the motor cortex and preferentially in the motor thalamus, i.e. ventrolateral nucleus. Systemic amphetamine, on the other hand, enhanced c-fos mRNA expression in the shell of the accumbens and in limbic thalamic nuclei such as the anteroventral and anterodorsal nuclei. The main effect observed after intra-accumbens administrations of either drug was enhanced c-fos expression in the thalamus, somewhat similar to what seen following systemic administration. In fact also in this case there was a preferential activation of the limbic thalamus by amphetamine and the motor thalamus by MK-801.The present results confirm that different neural substrates underlie behavioral effects induced by systemic administrations of N-methyl-D-aspartate receptor antagonists and dopamine agonists. Further they suggest that intra-accumbens manipulation of the two neural systems could affect different efferent pathways from this structure activating different thalamic targets. 相似文献
53.
Fifty women with polycystic ovaries took part in a prospective randomized
study. All women required treatment by in-vitro fertilization (IVF) for
reasons other than anovulation. They had all previously undergone ovarian
stimulation with gonadotrophin therapy which had failed to result in
pregnancy or had been abandoned due to high risk of developing ovarian
hyperstimulation syndrome (OHSS). Twenty-five women were treated by
long-term pituitary desensitization followed by gonadotrophin therapy,
oocyte retrieval and embryo transfer (group 1). Twenty-five women underwent
laparoscopic ovarian electrocautery after pituitary desensitization
followed by gonadotrophin therapy, oocyte retrieval and embryo transfer
(group 2). A significantly higher number of women in group 1 had to have
the treatment cycle abandoned due to impending or actual OHSS, determined
by endocrine and clinical findings. In addition, the development of
moderate or severe OHSS in completed cycles was higher in group 1. The
pregnancy rate and miscarriage rates in the two treatment groups were
similar. The authors propose that laparoscopic ovarian electrocautery is a
potentially useful treatment for women who have previously had an IVF
treatment cycle cancelled due to risk of OHSS or who have suffered OHSS in
a previous treatment cycle.
相似文献
54.
The bias favoring deletion over inversion in DH-JH rearrangement has been
known for years, but the underlying mechanism has yet to be fully defined.
It has been suggested that the ratio of deletion/inversion is determined by
the combined effect of two factors: (i) the relative strengths of 5' and 3'
recombination signal sequences (RSS) of a DH segment, and (ii) the
efficiency with which the deletional product (one joint) forms relative to
the inversional product (two joints). In this study, we analyzed for the
first time the effect of factor 1 alone on the biased 3' RSS utilization in
DH-JH joining by using deletional plasmids in an extrachromosomal substrate
V(D)J recombination assay. It was found that the 3' RSS and associated
coding end (12 bp) mediate recombination more efficiently than the 5'
RSS/coding end DH-JH plasmids. These results demonstrate that the effect of
the RSS/coding end alone can account, at least partially, for the
predominant deletion in DH-JH recombination. The potential effect of the
relative strength of RSS and associated coding end on the ordered
rearrangement of DH-JH followed by VH to DH-JH was also assessed. When
recombination frequencies of D-->J (3' DH to J3) were compared with
frequencies of V-- >D (VHPJ14 to 3' DH or VHOX2 to 3' DH), it was found
that V-->D joining was, if anything, more efficient than D-->J
joining. Therefore, if all three segments were accessible, RSS/coding end
effects would not contribute to the ordered rearrangement of the IgH locus.
相似文献
55.
Debelenko LV; Brambilla E; Agarwal SK; Swalwell JI; Kester MB; Lubensky IA; Zhuang Z; Guru SC; Manickam P; Olufemi SE; Chandrasekharappa SC; Crabtree JS; Kim YS; Heppner C; Burns AL; Spiegel AM; Marx SJ; Liotta LA; Collins FS; Travis WD; Emmert-Buck MR 《Human molecular genetics》1997,6(13):2285-2290
Lung carcinoids occur sporadically and rarely in association with multiple
endocrine neoplasia type 1 (MEN1). There are no well defined genetic
abnormalities known to occur in these tumors. We studied 11 sporadic lung
carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene
on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy
fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was
studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene
were inactivated. All four tumors showed the presence of a MEN1 gene
mutation and loss of the other allele. Observed mutations included a 1 bp
insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide
substitution affecting a donor splice site. Each mutation predicts
truncation or potentially complete loss of menin. The remaining seven
tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH.
The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a
complex germline MEN1 gene mutation. The data implicate the MEN1 gene in
the pathogenesis of sporadic lung carcinoids, representing the first
defined genetic alteration in these tumors.
相似文献
56.
M.D. Pereda C. Alonso L. Burgos-Asperilla J.A. del Valle O.A. Ruano P. Perez M.A. Fernández Lorenzo de Mele 《Acta biomaterialia》2010,6(5):1772-1782
Pure Mg has been proposed as a potential degradable biomaterial to avoid both the disadvantages of non-degradable internal fixation implants and the use of alloying elements that may be toxic. However, it shows excessively high corrosion rate and insufficient yield strength. The effects of reinforcing Mg by a powder metallurgy (PM) route and the application of biocompatible corrosion inhibitors (immersion in 0.1 and 1 M KF solution treatments, 0.1 M FST and 1 M FST, respectively) were analyzed in order to improve Mg mechanical and corrosion resistance, respectively. Open circuit potential measurements, polarization techniques (PT), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were performed to evaluate its corrosion behavior. SECM showed that the local current of attacked areas decreased during the F? treatments. The corrosion inhibitory action of 0.1 M FST and 1 M FST in phosphate buffered solution was assessed by PT and EIS. Under the experimental conditions assayed, 0.1 M FST revealed better performance. X-ray photoelectron spectroscopy, energy dispersive X-ray and X-ray diffraction analyses of Mg(PM) with 0.1 M FST showed the presence of KMgF3 crystals on the surface while a MgF2 film was detected for 1 M FST. After fluoride inhibition treatments, promising results were observed for Mg(PM) as degradable metallic biomaterial due to its higher yield strength and lower initial corrosion rate than untreated Mg, as well as a progressive loss of the protective characteristics of the F?-containing film which ensures the gradual degradation process. 相似文献
57.
Mengyun Hu Samuele Notarbartolo Mathilde Foglierini Sandra Jovic Federico Mele David Jarrossay Antonio Lanzavecchia Antonino Cassotta Federica Sallusto 《European journal of immunology》2023,53(2):2250190
T follicular helper (TFH) cells play an essential role in promoting B cell responses and antibody affinity maturation in germinal centers (GC). A subset of memory CD4+ T cells expressing the chemokine receptor CXCR5 has been described in human blood as phenotypically and clonally related to GC TFH cells. However, the antigen specificity and relationship of these circulating TFH (cTFH) cells with other memory CD4+ T cells remain poorly defined. Combining antigenic stimulation and T cell receptor (TCR) Vβ sequencing, we found T cells specific to tetanus toxoid (TT), influenza vaccine (Flu), or Candida albicans (C.alb) in both cTFH and non-cTFH subsets, although with different frequencies and effector functions. Interestingly, cTFH and non-cTFH cells specific for C.alb or TT had a largely overlapping TCR Vβ repertoire while the repertoire of Flu-specific cTFH and non-cTFH cells was distinct. Furthermore, Flu-specific but not C.alb-specific PD-1+ cTFH cells had a “GC TFH-like” phenotype, with overexpression of IL21, CXCL13, and BCL6. Longitudinal analysis of serial blood donations showed that Flu-specific cTFH and non-cTFH cells persisted as stable repertoires for years. Collectively, our study provides insights on the relationship of cTFH with non-cTFH cells and on the heterogeneity and persistence of antigen-specific human cTFH cells. 相似文献
58.
59.
Arianna Rinaldi Silvia Mandillo Alberto Oliverio Andrea Mele 《Neuropsychopharmacology》2007,32(2):309-319
The prefrontal cortex (PFC) is a cortical area involved in selecting and retaining information to produce complex behaviors. Within the PFC, the dopaminergic system plays an important role in information processing. Thus, the objective of this study was to test whether bilateral administration of the D1 and D2 receptor antagonists in the prelimbic region of the PFC influenced the performance of mice in a non-associative spatial learning task. CD1 mice were bilaterally microinjected in the PFC with either the D1 receptor antagonist, SCH23390 (SCH 6.25; 12.5; 50 ng), or the D2 receptor antagonist, sulpiride (SULP 12.5; 50; 100 ng) and placed into an open field containing five different objects. After three sessions of habituation two objects were repositioned (spatial change) and in the subsequent session one of the objects was substituted (non-spatial change). No significant alteration was observed in the habituation pattern of the animals after D1 or D2 receptor blockade. When two of the objects were displaced, control mice explored the displaced objects far more than the non-displaced ones, while mice treated with SCH or SULP spent a comparable amount of time re-exploring the two object categories. Conversely, DA antagonists had no effects on the discrimination of the new object. Thus, the administration of both SCH and SULP selectively impaired the ability of mice to discriminate a spatial change, without affecting any other behavioral parameter. These findings could provide a model to study the role of the PFC dopaminergic system in spatial learning and to study the neural mechanisms underlying cognitive and attention deficits often observed in psychiatric disorders. 相似文献
60.