Ovarian response to vascular and toxic insults in early life : focus on ovarian reserve and fertility preservation

The ovarian reserve is defined as the number of eggs embodied in primordial follicles. Every woman is born with a fixed number of primordial follicles, which are formed during fetal development. Pathological events can affect the ovarian reserve both preand postnatally and cause a premature ovarian insufficiency (POI), i.e. a precocious exhaustion of the endocrine and reproductive potential of the ovaries. In prenatal life, intrauterine growth restriction (IUGR) caused by poor maternal nutrition or insufficient placental flow to the fetus, has been associated with alterations in pubertal development and follicle number in animals and humans, with inconclusive evidence. In postnatal life, major iatrogenic causes of POI are chemo- and radiotherapeutic treatments administered to cancer patients. Fertility preservation strategies, such as ovarian tissue cryopreservation (OTC), are of fundamental importance to preserve fertility in these patients. These procedures are still experimental and in continuous evolution as more data are acquired. In this thesis, we aimed at investigate the impact of IUGR on ovarian follicles and gene expression in neonatal, juvenile and peripubertal rats, using a model of surgicallyinduced placental insufficiency. Secondly, we focused on the effects of chemotherapy exposure on ovarian follicles and stroma in ovarian tissues from cancer patients who underwent OTC for fertility preservation purposes. Additionally, we analyzed the efficacy of fertility preservation criteria in selecting the patients at high risk of infertility, by analysis of ovarian function during follow-up, the fruition rate and the timing of OTC in a large pediatric oncology unit in Finland. Timing of OTC was analyzed in relation to exposure to chemotherapy. A reduced primordial and total follicle count was found in the ovaries of neonate and juvenile rats. Follicle count normalized at peripubertal ages, alongside with the recovery of body weight. The expression of 24 genes was modified in the rat ovaries in response to the placental insufficiency. We interpreted the gene reprogramming as compensatory, possibly explaining the recovery of follicle number (by a downregulation of the physiological rates of follicle activation and/or depletion). The gene modifications could also have unknown long-term consequences on ovarian function, whose definition was beyond the aims of this work. An increased number of atretic follicles and a reduced size and number of residual intact follicles were evidenced in the ovaries of patients exposed to chemotherapy before OTC. Exposure to chemotherapy also reduced the secretion of steroid hormones in culture and damaged the ovarian stroma, by increasing collagen deposition and apoptosis. Finally, analysis of OTC data from Helsinki Children’s Hospital revealed that patients at high risk of infertility were correctly identified by the selection criteria, despite fruition rate was not optimal. We observed an increased risk of ovarian failure in older patients, which is in line with the age-related decline of the ovarian reserve. We also reported longer time frames between indication to OTC and execution of the procedure in patients with malignant diseases, which was associated to increased exposure to alkylating agents. Delays in the execution of OTC should be limited in order to avoid further damage to the ovarian tissue as a consequence of chemotherapy exposure, especially in older patients

The Impact of Stress on Health in Childhood and Adolescence in the Era of the COVID-19 Pandemic

Background: The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is posing many challenges to global health. Efforts from the whole scientific community have shed light on the pathogenetic mechanisms and the clinical features of SARS-CoV-2 infection as well as on potential therapeutic strategies. Summary: The consequences of stress related to social isolation and anxiety generated by the pandemic on mental and physical health are collateral effects that are yet poorly investigated

The Effects of Nutrition on Linear Growth

Linear growth is a complex process and is considered one of the best indicators of children's well-being and health. Genetics, epigenetics and environment (mainly stress and availability of nutrients) are the main regulators of growth. Nutrition exerts its effects on growth throughout the course of life with different, not completely understood mechanisms. Cells have a sophisticated sensing system, which allows growth processes to occur in the presence of an adequate nutrient availability. Most of the nutritional influence on growth is mediated by hormonal signals, in turn sensitive to nutritional cues. Both macro- and micro-nutrients are required for normal growth, as demonstrated by the impairment of growth occurring when their intake is insufficient. Clinical conditions characterized by abnormal nutritional status, including obesity and eating disorders, are associated with alterations of growth pattern, confirming the tight link between growth and nutrition. The precise molecular mechanisms connecting nutrition to linear growth are far from being fully understood and further studies are required. A better understanding of the interplay between nutrients and the endocrine system will allow one to develop more appropriate and effective nutritional interventions for optimizing child growth

Impact of first-line cancer treatment on the follicle quality in cryopreserved ovarian samples from girls and young women

STUDY QUESTION: Does first-line chemotherapy affect the quality of ovarian pre-antral follicles and stromal tissue in a population of young patients? SUMMARY ANSWER: Exposure to first-line chemotherapy significantly impacts follicle viability, size of residual intact follicles, steroid secretion in culture and quality of the stromal compartment. WHAT IS KNOWN ALREADY: First-line chemotherapy is considered to have a low gonadotoxic potential, and as such, does not represent an indication for fertility preservation. Studies investigating the effects of chemotherapy on the quality of ovarian tissue stored for fertility preservation in young patients are limited and the results sometimes contradictory. STUDY DESIGN, SIZE, DURATION: We conducted a retrospective cohort study including young patients referred to three centers (Helsinki, Oslo and Tampere) to perform ovarian tissue cryopreservation for fertility preservation between 2003 and 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 43 patients (age 1-24 years) were included in the study. A total of 25 were exposed to first-line chemotherapy before cryopreservation, whereas 18 patients were not. Density and size of follicles divided by developmental stages, prevalence of atretic follicles, health of the stromal compartment and functionality of the tissue in culture were evaluated and related to age and chemotherapy exposure. Activation of dormant follicles and DNA damage were also assessed. MAIN RESULTS AND THE ROLE OF CHANCE: Patients exposed to first-line chemotherapy showed a significantly higher density of atretic primordial and intermediary follicles than untreated patients. The intact primordial and intermediary follicles were significantly smaller in size in patients exposed to chemotherapy. Production of steroids in culture was also significantly impaired and a higher content of collagen and DNA damage was observed in the stromal compartment of treated patients. Collectively, these observations may indicate reduced quality and developmental capacity of follicles as a consequence of first-line chemotherapy exposure. Neither increased activation of dormant follicles nor elevated levels of DNA damage in oocyte nuclei were found in patients exposed to chemotherapy. LIMITATIONS, REASONS FOR CAUTION: The two groups were not homogeneous in terms of age and the patients were exposed to different treatments, which did not allow us to distinguish the effect of specific agents. The limited material availability did not allow us to perform all the analyses on the entire set of patients. WIDER IMPLICATION OF THE FINDINGS: This study provides for the first time a comprehensive analysis of the effects of first-line chemotherapy on the health, density and functionality of follicles categorized according to the developmental stage in patients under 24 years of age. When exposed to these treatments, patients were considered at low/medium risk of infertility. Our data suggest a profound impact of these relatively safe therapies on ovarian health and encourages further exploration of this effect in follow-up studies in order to optimize fertility preservation for young cancer patients.Peer reviewe

Efficacy and safety of advanced hybrid closed loop systems in children with type 1 diabetes younger than 6 years

BackgroundTight glycemic control is essential for the normal growth and development of preschool children. The aim of our study was to evaluate the impact of advanced hybrid closed loop (AHCL) systems in a real-life setting in children younger than 6 years.MethodsWe conducted a two-center prospective study. We enrolled 19 patients with a median age at disease onset of 2.6 years [interquartile range (IQR) 1.6; 4.4] and a median disease duration of 1.4 years (IQR 0.9; 2.8) who were switched to AHCL from multiple daily injections or open-loop insulin therapy and with a 6-month follow-up. Clinical data, sensor glycemic metrics, and pump settings were collected and analyzed.ResultsAfter 6 months of follow-up, there was a significant reduction in median HbA1c (p = 0.0007) and glucose management indicator (p = 0.03). A reduction in both mild (>180 mg/dL) (p = 0.04) and severe (>250 mg/dL) (p = 0.01) hyperglycemia was observed after 1 month of auto mode, and in mild hyperglycemia, it persisted up to 6 months (p = 0.02). A small increase in time below range (<70 mg/dL) was observed (p = 0.04) without a significant difference in time <54 mg/dL (p = 0.73). Time in range increased significantly, reaching a 10% increment (p = 0.03) compared with baseline. A significant reduction in the average sensor glucose was observed (p = 0.01) while coefficient of glucose variability (CV%) remained stable (p = 0.12). No episodes of ketoacidosis or severe hypoglycemia have been recorded.ConclusionAHCL systems are effective and safe for children younger than 6 years and should be considered as a valid therapeutic option from diabetes onset

The Silent Epidemic of Diabetic Ketoacidosis at Diagnosis of Type 1 Diabetes in Children and Adolescents in Italy During the COVID-19 Pandemic in 2020

To compare the frequency of diabetic ketoacidosis (DKA) at diagnosis of type 1 diabetes in Italy during the COVID-19 pandemic in 2020 with the frequency of DKA during 2017-2019

Long-acting growth hormone preparations and their use in children with growth hormone deficiency

Background: Daily recombinant human growth hormone (rhGH) is approved and marketed worldwide to treat children and adults with GH deficiency (GHD) and other conditions. Efficacy of rhGH therapy is influenced by several variables. Drop of treatment adherence over time has been recognized as a cause of reduced rhGH efficacy and has driven considerable efforts from pharmaceutical companies and scientists to develop long-acting rhGH (LAGH) formulations in order to relieve patients and their families from the burden of daily injections. Summary: Different technologies to manipulate drug release have been produced allowing weekly, biweekly or monthly rhGH administration. The LAGH formulations developed at present have demonstrated a comparable or even higher efficacy as compared with daily rhGH in most of the cases and no major safety issues in phase 3 studies. A greater incidence of injection-site reactions has been reported but mainly of mild and transient nature. Key messages: Despite LAGH analogs appearing promising, potential drawbacks still need to be addressed. Long-term consequences of un-physiological GH profile and its consequences on metabolism and risk of cancer, optimal therapeutic monitoring, immunogenicity of LAGH molecules and potential novel side-effects related to the technologies used to develop these molecules are among the major concerns that require answers from long-term surveillance. Finally, increased acceptance of LAGH formulations from patients and their caregivers is yet to be demonstrated and cost-effectiveness evaluated consequently

The Effects of Nutrition on Linear Growth

Linear growth is a complex process and is considered one of the best indicators of children’s well-being and health. Genetics, epigenetics and environment (mainly stress and availability of nutrients) are the main regulators of growth. Nutrition exerts its effects on growth throughout the course of life with different, not completely understood mechanisms. Cells have a sophisticated sensing system, which allows growth processes to occur in the presence of an adequate nutrient availability. Most of the nutritional influence on growth is mediated by hormonal signals, in turn sensitive to nutritional cues. Both macro- and micro-nutrients are required for normal growth, as demonstrated by the impairment of growth occurring when their intake is insufficient. Clinical conditions characterized by abnormal nutritional status, including obesity and eating disorders, are associated with alterations of growth pattern, confirming the tight link between growth and nutrition. The precise molecular mechanisms connecting nutrition to linear growth are far from being fully understood and further studies are required. A better understanding of the interplay between nutrients and the endocrine system will allow one to develop more appropriate and effective nutritional interventions for optimizing child growth

Impact of uteroplacental insufficiency on ovarian follicular pool in the rat

Abstract Background A low oxygen supply to the fetus causes intrauterine growth restriction and can affect gonadal development of the offspring, having a potential impact on fertility. We investigated histology and gene expression in the postnatal rat ovary after fetal hypoxia induced by uterine artery ligation. Methods Sprague-Dawley rats underwent uterine artery ligation at day 19 of gestation. Offspring were sacrificed at 5, 20 and 40 days post-partum. Follicles were counted and classified in hematoxylin-eosin stained sections. Gene expression of 90 genes was analyzed by TaqMan® Low Density Array. Results A significantly lower number of total and primordial follicles was detected in 20 days post-partum intrauterine growth restricted animals. Follicle density was not different at 40 days post-partum, suggesting that compensatory mechanisms occurred during the pre-pubertal window. Uterine artery ligation modified the expression of 24 genes involved in different cellular functions, among which proliferation, apoptosis and metabolism. Conclusion Ovarian follicle pool was affected by fetal hypoxia in early life, but this effect did not persist in puberty. Genes involved in cellular processes were affected at all ages, potentially implying long-term genetic alterations. Further analyses are needed to elucidate later effects of fetal hypoxia on ovarian function and fertility

Expression of insulin-like growth factor I and its receptor in the liver of children with biopsy-proven NAFLD - Fig 4

<p><b>Number of alpha-SMA positive cells (activated HSCs) expressing IGF-I (A) and IGF-IR (B) in the different stages of fibrosis.</b> Values are displayed as median and interquartile range (IQR).</p