We studied the alterations of dying oocytes in 1-28 days old rats using TUNEL method, immunolocalizations of active caspase 3, lamp1, localization of acid phosphatase, and DAPI staining. All procedures were performed in adjacent sections of each oocyte. In most dying oocytes exist simultaneously features of apoptosis as active caspase 3 and DNA breaks, and a large increase of lamp1 and acid phosphatase characteristic of autophagy. Large clumps of compact chromatin and membrane blebbing were absent. Electron microscope observations demonstrated the presence of small clear vesicles and autophagolysosomes. All these features indicate that a large number of oocytes are eliminated by a process sharing features of apoptosis and autophagy. In dying oocytes of new born rats the markers of apoptosis predominate over those of autophagy. However, fragmentation and apoptotic bodies were not found. These features suggest that in different cytophysiological conditions the processes of cell death may be differently modulated.
The synaptonemal complex (SC) is an evolutionarily conserved structure that mediates synapsis of homologous chromosomes during meiotic prophase I. Previous studies have established that the chromatin of homologous chromosomes is organized in loops that are attached to the lateral elements (LEs) of the SC. The characterization of the genomic sequences associated with LEs of the SC represents an important step toward understanding meiotic chromosome organization and function. To isolate these genomic sequences, we performed chromatin immunoprecipitation assays in rat spermatocytes using an antibody against SYCP3, a major structural component of the LEs of the SC. Our results demonstrated the reproducible and exclusive isolation of repeat deoxyribonucleic acid (DNA) sequences, in particular long interspersed elements, short interspersed elements, long terminal direct repeats, satellite, and simple repeats. The association of these repeat sequences to the LEs of the SC was confirmed by in situ hybridization of meiotic nuclei shown by both light and electron microscopy. Signals were also detected over the chromatin surrounding SCs and in small loops protruding from the lateral elements into the SC central region. We propose that genomic repeat DNA sequences play a key role in anchoring the chromosome to the protein scaffold of the SC.
The process of cell death of oocytes was studied in atretic ovarian follicles of rats aged from 1 to 28 days using light and electron microscope and cytochemical methods. These methods were TUNEL procedure for DNA breaks, active caspase-3 and lysosome-associated membrane protein 1 (LAMP-1) immunolocalizations. The structural features of the process of oocyte death are mainly characterized by the presence of abundant clear vacuoles and autophagosomes, as well as by the absence of large clumps of compact chromatin associated to the nuclear envelope and apoptotic bodies. These features are common to oocytes in all types of follicles studied. Cytochemical features consisting in positive reactions to TUNEL method, active caspase-3 and LAMP-1 immunolocalizations, are common to the cell death of oocytes in all types of follicles. Particular features of the process of cell death of oocytes are found in different types of follicles. Two morphological patterns of cell death occur in pre-follicular oocytes of the new born and in primordial follicles in 1 to 5 days old rats. One is distinguished by clear nucleoli and moderate compaction of chromatin in clumps frequently resembling meiotic bivalents. The second pattern is characterized by nucleolar condensation and by the absence of compact chromatin. The process of cell death of oocytes in antral follicles is characterized by ribonucleoprotein ribbon-like cytoplasmic structures, pseudo-segmentation, and loss of contact with granulosa cells.
Background: The importance of prebiotics consumption is increasing all over the world due to their beneficial effects on health. Production of better prebiotics from endemic plants raises possibilities to enhance nutritional effects in vulnerable population groups. Fructans derived from Agave Plant have demonstrated their safety and efficacy as prebiotics in animal models. Recently, the safety in humans of two fructans obtained from Agave tequilana (Metlin® and Metlos®) was demonstrated. Methods: This study aimed to demonstrate the efficacy as prebiotics of Metlin® and Metlos® in newborns of a randomized, double blind, controlled trial with a pilot study design. Biological samples were taken at 20 ± 7 days, and three months of age from healthy babies. Outcomes of efficacy include impact on immune response, serum ferritin, C-reactive protein, bone metabolism, and gut bacteria changes. Results: There were differences statistically significant for the groups of infants fed only with infant formula and with formula enriched with Metlin® and Metlos®. Conclusions: Our results support the efficacy of Metlin® and Metlos® as prebiotics in humans, and stand the bases to recommend their consumption. Trial Registration: ClinicalTrials.gov, NCT 01251783.
Summary:Relatively few cases of the 20 ring chromosome [r(20)] syndrome have been reported. Epileptic seizures, behavioral problems, mental retardation, and absence of definite dysmorphic features characterize this syndrome. We present a patient with the classic genetic and phenotypic findings. A 42-month-old boy with mild dysmorphic features and psychomotor retardation has had generalized tonic-clonic seizures, resistant to antiepileptic drug therapy since he was 26 months old. Electroencephalography (EEG) was performed on several occasions, as were brainstem auditory evoked potentials (BAEPs), magnetic resonance imaging (MRI), and cytogenetic studies. The EEG showed slow waves in anterior regions intermingled with spikes in temporal areas. The BAEPs were abnormal, and neuroimaging studies were normal. The chromosome r(20) appeared in 100 metaphases studied. Parental chromosomes were of normal karyotype. The genetic and EEG finding from this patient strongly suggest that epilepsy associated with 20 ring chromosome syndrome is a distinct new entity, although the clinical manifestations may be broader than previously recognized.
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