Association study of GIT1 gene with attention‐deficit hyperactivity disorder in Brazilian children and adolescents

Attention‐deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in children with a worldwide prevalence of 5.3%. Recently, a Korean group assessed the G‐protein‐coupled receptor kinase‐interacting protein 1 (GIT1) gene that had previously been associated with ADHD. In their work, 27 single nucleotide polymorphisms SNPs in the GIT1 gene were tested; however, only the rs550818 SNP was associated with ADHD susceptibility. Moreover, the presence of the risk‐associated allele determined reduced GIT1 expression, and Git1‐deficient mice exhibit ADHD‐like phenotypes. The aim of this study was to determine if this association also occurs in a sample of Brazilian children with ADHD. No effect of GIT1 genotypes on ADHD susceptibility was observed in the case–control analysis. The odds ratios (ORs) were 0.75 (P = 0.184) for the CT genotype and 1.09 (P = 0.862) for the TT genotype. In addition, the adjusted OR of the CT+TT genotypes vs. the CC genotype was also estimated (P = 0.245). There were no dimensional associations between the GIT1 genotypes and both hyperactivity and /impulsivity, and only hyperactivity Swanson, Nolan and Pelham Scale‐Version IV (SNAP‐IV) scores (P = 0.609 and P = 0.247, respectively). The transmission/disequilibrium test indicated that there was no over‐transmission of rs550818 alleles from parents to ADHD children (z = 0.305; P = 0.761). We conclude that rs550818 is not associated with ADHD in this Brazilian sample. More studies are required before concluding that this polymorphism plays a role in ADHD susceptibility.     

The effect of age on the ability of oocytes to synthesize RNA and proteins during in vitro maturation

Summary The effect of age on the ability of the oocyte to resume meiosis in vitro and to incorporate ³H-uridine and ³H-leucine into RNA and protein, respectively, was examined in the rat. In comparison with the mature control oocyte, the nucleolus of the aged oocyte tends to be retained although the rate of germinal vesicle breakdown is not altered. The incorporation of ³H-uridine is reduced, while ³H-leucine incorporation is not impaired. It is concluded that the inability of the aged oocyte to synthesize RNA may be responsible for its inability to complete meiotic maturation in vitro.This work was supported in part by a grant from the Easter Seal Research Foundation of the National Easter Seal Society for Crippled Children and Adults     

Temporal and endocrine sequelae of aspirating follicular contents in rhesus monkeys

Aspiration of ovarian follicular contents in humans is a well-established procedure used to obtain oocytes for fertilization in vitro (IVF). However, the effects of aspiration on the menstrual cycle and resulting luteal function have been incompletely characterized. The present study was designed to investigate alterations in the temporal and endocrine characteristics of menstrual cycles following aspiration of contents of the dominant preovulatory follicle (DF) on day 10 of the cycle in normal rhesus monkeys. When aspiration was performed prior to the preovulatory surge of luteinizing hormone (LH), cycle length was extended to 38.6 ± 8.6 [15] (x days ± SD, [n]), as compared to 29.5 ± 5.7 [8] days when the surge occurred before the time of aspiration. Mean and maximal amounts of progesterone (P) in the luteal phase and the number of days in which P-values were > 1 ng/ml were significantly greater when aspiration was performed prior to the surge of LH than for aspiration after this event. Laparoscopic observations made in the midluteal phase in animals of the former group demonstrated that the corpus luteum (CL was derived from a follicle other than the original DF which had been aspirated on day 10 of the menstrual cycle; observations in the latter group of animals indicated that the CL was derived from the DF.     

Technologic advances in the imaging of ovarian morphology and their roles in ascertaining follicular growth and development in the rhesus monkey

Imaging follicular development has advanced notably from the invasive—laparotomy—to the relatively noninvasive—laparoscopy (making frequent observations over a single cycle possible)—to totally noninvasive approaches such as ultrasonography and magnetic resonance imaging (MRI). Now we can identify the dominant preovulatory follicle (DF) in macaques by day 6 of the menstrual cycle via laparoscopy and by day 6–8 via ultrasonography. MRI scans are remarkably correlated with histologic specimens. We obtained axial, coronal, and sagittal ovarian images with MRI software. Moreover, we are discerning structure/function relationships in ovarian estrogen-receptor systems using X-ray autoradiography and immunocytochemistry. We have localized the estrogen receptor in functional corpus luteum (CL) with ³H-estradiol and in germinal epithelium and granulosa cells with monoclonal antibody to the receptor. We believe that by using a combination of the aforementioned techniques, we will be able to investigate more fully the processes of recruitment and selection of ovarian follicles.     

Atretogenic action of estrogen in rhesus monkeys: Effects of repeated treatment

The effects of 17β-estradiol (E₂), administered in Silastic capsules for 24 hours at intervals of 10 or 14 days, on follicular development and menstrual cycle characteristics were studied in 13 rhesus monkeys. In seven monkeys receiving E₂ at l0-day intervals for 50 treatment periods, new follicles frequently developed between treatments but usually regressed. In seven instances, the follicles persisted longer than expected but were steroidogenically suppressed and regressed spontaneously. Ovulation occurred in only two instances. In six monkeys receiving E₂ at 14-day intervals, new follicles developed regularly, with seven ovulations occurring in 37 treatment periods. A persistent anovulatory follicle was noted in only one instance. Menstruation occurred with equal frequency, and the interval from treatment to onset of menstruation was not significantly different regardless of treatment or the occurrence of ovulation; the intervals between menstruation approximated those of normal menstrual cycles. In general, following termination of treatment, menstrual cycles returned to normal quickly. These data indicate that E₂ administered intermittently at 10-day intervals effectively suppresses ovulation, and they provide new insight into the actions of E₂ on folliculogenesis in primates.     

Sources of fish in the ephemeral western iishana region of the Cuvelai–Etosha Basin in Angola and Namibia

The triangle between the Kavango and Kunene rivers is drained by the Cuvelai, an ephemeral and deltaic drainage system covering more than 100 000 km². In good rainfall years, the area becomes populated by fish communities dominated by five species migrating southward towards the endorheic Etosha Pan, the basin’s terminal sump. When water dries up, fish subsequently die-off and their sudden appearance in rainy years has captivated scientists for decades. The current study was prompted by hitherto untapped indigenous knowledge through narratives of opportunistic fish harvesting of migrating fish at temporary connections between the Kunene River and the Cuvelai- Etosha Basin. A reconnaissance fish survey in 2017 was complemented by digital satellite images and elevation data analyses. Results support the presence of at least three major ephemeral fish migration routes. The dominant fish genera migrating upstream in Kunene tributaries comprise Enteromius, Oreochromis and Clarias, all eurytopic and known to undertake upstream, lateral and downstream migrations on floodplains. Although other notable fish refugia in the Cuvelai–Etosha Basin are yet to be identified, there is a necessity for the protection and management of these migration routes in tandem with studies on the nature and extent of this inter-basin fish migration under climate change and variability.     

Changes in follicular populations, in serum estrogen and progesterone, and in ovarian steroid secretion in vitro during the guinea pig estrous cycle

It has been proposed that the guinea pig estrous cycle manifests biphasic follicular development. The follicles of one cohort apparently achieve their greatest diameter by approximately Day 10 of the cycle and then undergo atresia while the second cohort ovulates; this constitutes an uninvestigated and novel model for the evaluation of atresia. In this study, follicular development was evaluated in vivo and in vitro to confirm this pattern. On cycle Day 3, 5, 7, 10, 12, 15 or 0 (ovulation), guinea pigs were killed and trunk blood was collected; ovaries were excised, weighed, and measured, and size and number of large (greater than 400 microns) follicles were determined. Ovaries were quartered and placed into culture dishes for incubation. Culture variables were presence or absence of human follicle-stimulating hormone (100 ng/ml) and time. Ovarian fragments were processed for histology. Estrogen (E) and progesterone (P) in sera and culture media were analyzed by radioimmunoassay. The abundance of large follicles on both the ovarian surface (greater than 635 microns) and in histologic section (greater than 500 microns) relative to all follicles observed was high on Day 7 and Day 10, respectively; lower on Day 10 and Day 12; and high again at Day 12 and Day 15. Mean secretion of E in culture was elevated on Day 10 (253.0 +/- 60.3 pg/ml/mg ovary), low on Day 12 (67.9 +/- 13.0), and high again on Day 0 (185.8 +/- 56.8). Peripheral P reached a maximum of 2.93 +/- 0.09 ng/ml (Day 5), and then declined to Day 15.(ABSTRACT TRUNCATED AT 250 WORDS)     

Direct effect of estradiol-17β on progesterone accumulation by ovarian granulosa cells from rhesus monkeys

We have previously demonstrated that estradiol-17β (E₂) administered in vivo induces atresia of the dominant ovarian follicle (DF). Whether this effect is exerted directly at the ovarian level or by central mediation has not been confirmed. The present study was designed to assess whether E₂ in amounts similar to those found in monkey follicular fluid (FF) directly alters in vitro progesterone (P) accumulation by granulosa cells (GC) aspirated from follicles in cycling rhesus monkeys. Follicular contents were aspirated from three to five animals on each of days 8–13 of the cycle. GC were plated at a density of 50,000 viable GC/0.5 ml medium; GC were incubated with 0 or 2–2,000 ng/ml E₂, and cultures were maintained for 72 h. P accumulation by GC collected on day 8 and treated with 2 ng/ml E₂ was augmented 37.5 ± 5.5% (X ± S. E. M.; P<.05) over controls but was diminished significantly at 20 ng/ml ( ?55 ± 18% with respect to controls), 200 ng/ml ( ?73.7 ± 13.2%), and 2,000 ng/ml ( ?77.3 ± 18.4%). A similar dose-response relationship was noted on other cycle days. At a concentration of 2,000 ng/ml, E₂ significantly reduced P 91.5 ± 8.5% (day 10), 81.5 ± 18.5% (day 11), 84.3 ± 4.7% (day 12), and 53.7 ± 15.8% (day 13). We conclude that E₂ at concentrations found in FF can inhibit P output by monkey GC through a direct action.     

High interpopulation homogeneity in Central Argentina as assessed by Ancestry Informative Markers (AIMs)

The population of Argentina has already been studied with regard to several genetic markers, but much more data are needed for the appropriate definition of its genetic profile. This study aimed at investigating the admixture patterns and genetic structure in Central Argentina, using biparental markers and comparing the results with those previously obtained by us with mitochondrial DNA (mtDNA) in the same samples. A total of 521 healthy unrelated individuals living in 13 villages of the Córdoba and San Luis provinces were tested. The individuals were genotyped for ten autosomal ancestry informative markers (AIMs). Allele frequencies were compared with those of African, European and Native American populations, chosen to represent parental contributions. The AIM estimates indicated a greater influence of the Native American ancestry as compared to previous studies in the same or other Argentinean regions, but smaller than that observed with the mtDNA tests. These differences can be explained, respectively, by different genetic contributions between rural and urban areas, and asymmetric gene flow occurred in the past. But a most unexpected finding was the marked interpopulation genetic homogeneity found in villages located in diverse geographic environments across a wide territory, suggesting considerable gene flow.