342 research outputs found

    Effect of genistein and oestradiol on the adrenal cortex of the ovariectomised adult female albino rats

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    Background: Genistein, a naturally occurring soy isoflavone, attracts interest as an effective and safe alternative to hormone replacement therapy for menopausal problems. The aim of the current study was to compare between the effect of genistein and oestradiol on the adrenal cortex of the ovariectomised adult female albino rats. Materials and methods: Twenty rats were used in the current study and divided into four groups, 5 rats in each group; group 1 (control non-ovariectomised), group 2 (ovariectomised), group 3 (ovariectomised + genistein) and group 4 (ovariectomised + oestradiol). The rats were sacrificed after 4 weeks. Both adrenal glands were removed for light microscope using haematoxylin and eosin stain, ultrastructural study and immunohistochemical examination using proliferating cell nuclear antigen, caspase-3, and oestrogen receptor-b. Results: Ovariectomised rats showed signs of degeneration in all zones of adrenal cortex. On the other hand, treatment with genistein showed restoration of the adrenal cortex with less proliferative effect than oestradiol. Conclusions: So, genistein can be used as effective therapy to decrease the symptoms of menopause without fear of cancer development

    Therapeutic role of bone marrow mesenchymal stem cells in diabetic neuronal alternations of rat hippocampus

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    Background: As the hippocampus is the main brain region for many forms of learning and memory functions and is acutely sensitive to blood glucose changes, diabetes mellitus, which is a serious metabolic disease, is often accompanied by learning and memory deficits. Through scientific literatures, mesenchymal stem cells (MSCs) promote functional recovery in rats with traumatic brain injury, so the present work was conducted to study MSCs as a possible treatment for the diabetic neuronal degeneration and functional impairment of rat hippocampus. Materials and methods: It was carried out using male albino rats: non-diabetic control groups (4, 8, 12 weeks) (n = 15), diabetic groups by i.v. injection of streptozotocin for (4, 8, 12 weeks) (n = 15) and MSCs treatment to diabetic groups for (8, 12 weeks) (n = 10). Hippocampal learning and memory functions were assessed by the Morris Water Maze test and its results were statistically analysed. The rat hippocampal regions (CA1 and CA3) were subjected to histological, ultrastructural examination and morphometrical analyse of pyramidal neurons. Results: Neurons of the diabetic groups showed disturbed function and architecture; shrunken hyperchromatic nuclei and vacuolated eosinophilic cytoplasm (apoptotic changes) also MSCs treatment improved hippocampal learning and memory functions plus its architectural changes; increasing populations and normal regular distribution. Conclusions: It can be concluded that diabetic hippocampal neuronal alternations and functional impairment can be ameliorated by MSCs treatment

    Elevated activity of the sympathetic nervous system is related to diminished practice effects in memory:A pilot study

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    BACKGROUND: Reductions in memory practice effects have gained interest as risk factor for future cognitive decline. Practice effects vary with age and can be moderated by factors such as individual variability in arousal or stress experience acting as an additional cognitive load. OBJECTIVE: In the current pilot study, we examined whether sympathetic nervous system activation moderates the relationship between age and practice effects. METHODS: Thirty cognitively healthy individuals aged 40–70 years performed a mnemonic discrimination task twice. Salivary alpha amylase (sAA) samples were obtained at different time points as a proxy of sympathetic activity. Spearman correlations examined the relation between practice effects and sAA. Subsequently, age by sAA interactions on practice scores were explored with bootstrapped linear regression models. Additionally, participants were divided in learners (exhibiting practice effects) and non-learners based on the difference in mnemonic discrimination performance. RESULTS: Higher age and baseline SNS activity were independently related to lower practice effects. The non-learners showed significantly higher sAA scores at all time points compared to learners. Among the learners, baseline-adjusted lower levels of sAA after encoding were associated with greater practice effects, particularly in middle-aged individuals. No such interaction was observed for non-learners. CONCLUSION: These results show that higher baseline sympathetic activation is associated with worse practice effects independently of age. Additionally, in a subgroup of middle-aged learners practice effects were observed when sympathetic activity remained low during learning. These findings suggest that elevated sympathetic nervous system activation may be a promising indicator of imminent cognitive decline

    Aberrant Maturation of the Uncinate Fasciculus Follows Exposure to Unpredictable Patterns of Maternal Signals

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    Across species, unpredictable patterns of maternal behavior are emerging as novel predictors of aberrant cognitive and emotional outcomes later in life. In animal models, exposure to unpredictable patterns of maternal behavior alters brain circuit maturation and cognitive and emotional outcomes. However, whether exposure to such signals in humans alters the development of brain pathways is unknown. In mother–child dyads, we tested the hypothesis that exposure to more unpredictable maternal signals in infancy is associated with aberrant maturation of corticolimbic pathways. We focused on the uncinate fasciculus, the primary fiber bundle connecting the amygdala to the orbitofrontal cortex and a key component of the medial temporal lobe–prefrontal cortex circuit. Infant exposure to unpredictable maternal sensory signals was assessed at 6 and 12 months. Using high angular resolution diffusion imaging, we quantified the integrity of the uncinate fasciculus using generalized fractional anisotropy (GFA). Higher maternal unpredictability during infancy presaged greater uncinate fasciculus GFA in children 9–11 years of age (n = 69, 29 female). In contrast to the uncinate, GFA of a second corticolimbic projection, the hippocampal cingulum, was not associated with maternal unpredictability. Addressing the overall functional significance of the uncinate and cingulum relationships, we found that the resulting imbalance of medial temporal lobe–prefrontal cortex connectivity partially mediated the association between unpredictable maternal sensory signals and impaired episodic memory function. These results suggest that unbalanced maturation of corticolimbic circuits is a mechanism by which early unpredictable sensory signals may impact cognition later in life

    Diagnosis and Reporting of Follicular-Patterned Thyroid Lesions by Fine Needle Aspiration

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    Over the past 3 decades, fine needle aspiration (FNA) has developed as the most accurate and cost-effective initial method for guiding the clinical management of patients with thyroid nodules. Thyroid FNA specimens containing follicular-patterned lesions are the most commonly encountered and include various forms of benign thyroid nodules, follicular carcinomas, and the follicular variant of papillary thyroid carcinoma. Based primarily upon the cytoarchitectural pattern, FNA is used as a screening test for follicular-patterned lesions to identify the majority of patients with benign nodules who can be managed without surgical intervention. The terminology and reporting of thyroid FNA results have been problematic due to significant variation between laboratories, but the recent multidisciplinary NCI Thyroid FNA State of the Science Conference has provided a seven-tiered diagnostic solution. A key element of this approach is the category “atypical cells of undetermined significance” (ACUS) which is used for those aspirates which cannot be easily classified as benign, suspicious, or malignant. Lesions in this category represent approximately 3–6% of thyroid FNAs and have a risk of malignancy intermediate between the “benign” category and the “suspicious for a follicular neoplasm” category. The recommended follow-up for an ACUS diagnosis is clinical correlation and in most cases, repeat FNA sampling

    Cortical Thinning in Patients with Recent Onset Post-Traumatic Stress Disorder after a Single Prolonged Trauma Exposure

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    Most of magnetic resonance imaging (MRI) studies about post-traumatic stress disorder (PTSD) focused primarily on measuring of small brain structure volume or regional brain volume changes. There were rare reports investigating cortical thickness alterations in recent onset PTSD. Recent advances in computational analysis made it possible to measure cortical thickness in a fully automatic way, along with voxel-based morphometry (VBM) that enables an exploration of global structural changes throughout the brain by applying statistical parametric mapping (SPM) to high-resolution MRI. In this paper, Laplacian method was utilized to estimate cortical thickness after automatic segmentation of gray matter from MR images under SPM. Then thickness maps were analyzed by SPM8. Comparison between 10 survivors from a mining disaster with recent onset PTSD and 10 survivors without PTSD from the same trauma indicates cortical thinning in the left parietal lobe, right inferior frontal gyrus, and right parahippocampal gyrus. The regional cortical thickness of the right inferior frontal gyrus showed a significant negative correlation with the CAPS score in the patients with PTSD. Our study suggests that shape-related cortical thickness analysis may be more sensitive than volumetric analysis to subtle alteration at early stage of PTSD

    The new molecular markers DDIT3, STT3A, ARG2 and FAM129A are not useful in diagnosing thyroid follicular tumors

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    Preoperative characterization of thyroid follicular lesions is challenging. Fine-needle aspiration specimens cannot differentiate follicular carcinomas from benign follicular neoplasias. Recently, promising markers have been detected using modern molecular techniques. We conducted a retrospective study to confirm the usefulness of immunohistochemical staining for the protein markers, DDIT3, STT3A (ITM1), ARG2 and FAM129A (C1orf24) in separating benign and malignant thyroid follicular lesions. Formalin-fixed, paraffin-embedded thyroid tissue from 30 in-house cases (15 follicular carcinomas and 15 follicular adenomas), as well as 8 follicular carcinomas and 21 follicular adenomas on tissue microarray slides were stained immunohistochemically for DDIT3, STT3A, ARG2 and FAM129A expression. Control tissue consisted of thyroid parenchyma adjacent to the tumors and 11 separate cases of normal thyroid parenchyma. All in-house cases of follicular adenomas, follicular carcinomas and adjacent normal thyroid tissue showed positive immunostaining with anti-DDIT3 and anti-STT3A. Anti-ARG2 and anti-FAM129A polyclonal antibodies showed positive staining in 20 and 60% of in-house follicular adenomas, and 40 and 87% of in-house follicular carcinomas, respectively. Monoclonal anti-FAM129A demonstrated positive staining in 13 and 33% of in-house follicular adenomas and follicular carcinomas, respectively. Polyclonal anti-DDIT3, -STT3A and -FAM129A antibodies showed positive staining in all tissue microarray slides of follicular carcinoma and in 76, 85 and 81% of the follicular adenomas, respectively. Monoclonal anti-STT3A stained 81% of the follicular adenoma cores. Anti-ARG2 stained positive in 13% of follicular carcinomas and 10% of follicular adenomas on the tissue microarray slides. In conclusion, DDIT3, STT3A, ARG2 and FAM129A immunohistochemistry does not appear to be useful in the diagnosis of thyroid follicular neoplasias, as they do not reliably distinguish follicular thyroid carcinoma from follicular thyroid adenoma

    Assembly and dynamics of the bacteriophage T4 homologous recombination machinery

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    Homologous recombination (HR), a process involving the physical exchange of strands between homologous or nearly homologous DNA molecules, is critical for maintaining the genetic diversity and genome stability of species. Bacteriophage T4 is one of the classic systems for studies of homologous recombination. T4 uses HR for high-frequency genetic exchanges, for homology-directed DNA repair (HDR) processes including DNA double-strand break repair, and for the initiation of DNA replication (RDR). T4 recombination proteins are expressed at high levels during T4 infection in E. coli, and share strong sequence, structural, and/or functional conservation with their counterparts in cellular organisms. Biochemical studies of T4 recombination have provided key insights on DNA strand exchange mechanisms, on the structure and function of recombination proteins, and on the coordination of recombination and DNA synthesis activities during RDR and HDR. Recent years have seen the development of detailed biochemical models for the assembly and dynamics of presynaptic filaments in the T4 recombination system, for the atomic structure of T4 UvsX recombinase, and for the roles of DNA helicases in T4 recombination. The goal of this chapter is to review these recent advances and their implications for HR and HDR mechanisms in all organisms
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