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21.
Humanin (HN) is a 24-amino acid peptide with cytoprotective action in several cell types such as neurons and testicular germ cells. Rattin (HNr), a homologous peptide of HN expressed in several adult rat tissues, also has antiapoptotic action. In the present work, we demonstrated by immunocytochemical analysis and flow cytometry the expression of HNr in the anterior pituitary of female and male adult rats as well as in pituitary tumor GH3 cells. HNr was localized in lactotropes and somatotropes. The expression of HNr was lower in females than in males, and was inhibited by estrogens in pituitary cells from both ovariectomized female and orquidectomized male rats. However, the expression of HNr in pituitary tumor cells was not regulated by estrogens. We also evaluated HN action on the proapoptotic effect of TNF-α in anterior pituitary cells assessed by the TUNEL method. HN (5 µM) per se did not modify basal apoptosis of anterior pituitary cells but completely blocked the proapoptotic effect of TNF-α in total anterior pituitary cells, lactotropes and somatotropes from both female and male rats. Also, HN inhibited the apoptotic effect of TNF-α on pituitary tumor cells. In summary, our results demonstrate that HNr is present in the anterior pituitary gland, its expression showing sexual dimorphism, which suggests that gonadal steroids may be involved in the regulation of HNr expression in this gland. Antiapoptotic action of HN in anterior pituitary cells suggests that this peptide could be involved in the homeostasis of this gland. HNr is present and functional in GH3 cells, but it lacks regulation by estrogens, suggesting that HN could participate in the pathogenesis of pituitary tumors.  相似文献   
22.
We have found that sarcoplasmic reticulum from rabbit muscle contains an ADPase which cleaves ADP bound to F-actin. The interaction is not of the simple Michaelis-Menten type, the order of the reaction being larger than the first. A possible explanation of this behaviour could be that ADPase binds to two adjacent actin monomers with a preferred orientation thus cleaving preferentially the nucleotide of one of the two monomers.  相似文献   
23.
The antisense oligonucleotide Nusinersen has been recently licensed to treat spinal muscular atrophy (SMA). Since SMA type 3 is characterized by variable phenotype and milder progression, biomarkers of early treatment response are urgently needed. We investigated the cerebrospinal fluid (CSF) concentration of neurofilaments in SMA type 3 patients treated with Nusinersen as a potential biomarker of treatment efficacy. The concentration of phosphorylated neurofilaments heavy chain (pNfH) and light chain (NfL) in the CSF of SMA type 3 patients was evaluated before and after six months since the first Nusinersen administration, performed with commercially available enzyme-linked immunosorbent assay (ELISA) kits. Clinical evaluation of SMA patients was performed with standardized motor function scales. Baseline neurofilament levels in patients were comparable to controls, but significantly decreased after six months of treatment, while motor functions were only marginally ameliorated. No significant correlation was observed between the change in motor functions and that of neurofilaments over time. The reduction of neurofilament levels suggests a possible early biochemical effect of treatment on axonal degeneration, which may precede changes in motor performance. Our study mandates further investigations to assess neurofilaments as a marker of treatment response.  相似文献   
24.

Background

Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by visual loss consequent to optic nerve atrophy. In some cases, LHON is associated with heterogeneous neurological extraocular manifestations and is referred to as “Leber plus disease”; rarely it is associated with a multiple sclerosis (MS)-like syndrome known as Harding disease, but no pediatric extraocular acute spinal onset is reported.

Case presentation

We describe the case of a 5-year-old girl carrying the G3460A mtDNA mutation who was referred to clinical examination for bilateral upper and lower limb weakness with no sign of optic neuropathy. Spinal cord MRI showed hyperintense signal alterations in T2-weighted and restricted diffusion in DWI sequences in the anterior portion of the cervical and dorsal spinal cord resembling a spinal cord vascular injury. No association between this mutation and pediatric spinal cord lesions has previously been reported. Alternative diagnostic hypotheses, including infective, ischemic and inflammatory disorders, were not substantiated by clinical and instrumental investigations.

Conclusions

Our case reports a novel pediatric clinical manifestation associated with the m.3460G?>?A mtDNA mutation, broadening the clinical spectrum of this disease. Early identification of new cases and monitoring of carriers beginning in childhood is important to prevent neurological deterioration and preserve long-term function.
  相似文献   
25.
Active subunits of rabbit liver fructose diphosphatase   总被引:2,自引:0,他引:2  
Fructose diphosphatase, bound to a matrix of Sepharose, retains most of the catalytic activity but becomes half desensitized to AMP. The dimers, obtained by acid dissociation of the enzyme bound to the matrix, possess half of the specific activity of the tetramers and are almost completely desensitized to AMP. The monomers are inactive.  相似文献   
26.
The new thrusts in molecular logic are gathered together in this short review, while paying attention to the seeds from which these developments have arisen. The original demonstration of a few basic logic operations has now been extended to cover many of the one- and two-input varieties and even some of the three-input types. Many kinds of inputs and outputs have emerged, including various chemical species and some physical properties. The latter can include heat, light and, arguably, polarity. Reconfigurable logic has grown up to include a range of examples. Even superposable logic has proved possible with molecular systems. Numerical processors have flowered in recent years with several diverse approaches being revealed in recent years. Photochemical concepts such as photoinduced electron transfer (PET), internal charge transfer (ICT) and electronic energy transfer (EET) can be discerned among the designs in the field.  相似文献   
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Physiological characteristics, DNA base composition (% GC) and DNA-DNA reassociation values were determined for 138 Lactobacillus acidophilus strains. Twenty seven strains were received from various culture collections and 111 strains were freshly isolated during a study on the composition of the intestinal lactic microflora of piglets and suckling calves.All strains had physiological characteristics which were substantially similar. The strains isolated from pigs were unable to ferment trehalose. The % GC ranged from 35.8 to 43.4.On the basis of the results of DNA-DNA hybridization the strains were divided into four genetic groups.This study was partially supported by grants from the Consiplio Nazionale Ricerche (C.N.R.).  相似文献   
30.
The phylogeography of Y-chromosome haplogroups E (Hg E) and J (Hg J) was investigated in >2400 subjects from 29 populations, mainly from Europe and the Mediterranean area but also from Africa and Asia. The observed 501 Hg E and 445 Hg J samples were subtyped using 36 binary markers and eight microsatellite loci. Spatial patterns reveal that (1). the two sister clades, J-M267 and J-M172, are distributed differentially within the Near East, North Africa, and Europe; (2). J-M267 was spread by two temporally distinct migratory episodes, the most recent one probably associated with the diffusion of Arab people; (3). E-M81 is typical of Berbers, and its presence in Iberia and Sicily is due to recent gene flow from North Africa; (4). J-M172(xM12) distribution is consistent with a Levantine/Anatolian dispersal route to southeastern Europe and may reflect the spread of Anatolian farmers; and (5). E-M78 (for which microsatellite data suggest an eastern African origin) and, to a lesser extent, J-M12(M102) lineages would trace the subsequent diffusion of people from the southern Balkans to the west. A 7%-22% contribution of Y chromosomes from Greece to southern Italy was estimated by admixture analysis.  相似文献   
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