Whole-slide imaging and a Fiji-based image analysis workflow of immunohistochemistry staining of pancreatic islets.

Quantification of cell populations in tissue sections is frequently examined in studies of human disease. However, traditional manual imaging of sections stained with immunohistochemistry is laborious, time-consuming, and often assesses fields of view rather than the whole tissue section. The analysis is usually manual or utilises expensive proprietary image analysis platforms. Whole-slide imaging allows rapid automated visualisation of entire tissue sections. This approach increases the quantum of data generated per slide, decreases user time compared to manual microscopy, and reduces selection bias. However, such large data sets mean that manual image analysis is no longer practicable, requiring an automated process. In the case of diabetes, the contribution of various pancreatic endocrine cell populations is often investigated in preclinical and clinical samples. We developed a two-part method to measure pancreatic endocrine cell mass, firstly describing imaging using an automated slide-scanner, and secondly, the analysis of the resulting large image data sets using the open-source software, Fiji, which is freely available to all researchers and has cross-platform compatibility. This protocol is highly versatile and may be applied either in full or in part to analysis of IHC images created using other imaging platforms and/or the analysis of other tissues and cell markers.

Cortical Oxygenation Changes during Gastric Tube Feeding in Moderate- and Late-Preterm Babies: A NIRS Study.

Smell and taste of food can trigger physiological responses facilitating digestion and metabolism of nutrients. Controlled experimental studies in preterm babies have demonstrated that smell activates the orbitofrontal cortex (OFC) but none have investigated the effect of taste stimulation. Using cotside Near-Infrared Spectroscopy (NIRS), we measured changes in OFC cerebral oxygenation in response to gastric tube feeds five and 10 days after birth in 53 assessments of 35 moderate- to late-preterm babies enrolled in a randomized trial. Babies were randomly assigned to receive smell and taste of milk before gastric tube feeds (intervention group, n = 16) or no exposure (control group, n = 19). The majority of babies were born at 33 weeks of gestation (range 32-34) and 69% were boys. No differences in OFC cerebral oxygenation were observed between control and intervention groups. Gastric tube feeds induced activation of the OFC (p < 0.05), but sensory stimulation alone with smell and taste did not. Boys, but not girls, showed activation of the OFC following exposure to smell of milk (p = 0.01). The clinical impact of sensory stimulation prior to tube feeds on nutrition of preterm babies, as well as the impact of environmental inputs on cortical activation, remains to be determined.

Effects of intrauterine insulin-like growth factor-1 therapy for fetal growth restriction on adult metabolism and body composition are sex specific.

Fetal growth restriction (FGR) is associated with compromised growth and metabolic function throughout life. Intrauterine therapy of FGR with intra-amniotic insulin-like growth factor-1 (IGF1) enhances fetal growth and alters perinatal metabolism and growth in a sex-specific manner, but the adult effects are unknown. We investigated the effects of intra-amniotic IGF1 treatment of FGR on adult growth and body composition, adrenergic sensitivity, and glucose-insulin axis regulation. Placental embolization-induced FGR was treated with four weekly doses of 360 µg intra-amniotic IGF1 (FGRI) or saline (FGRS). Offspring were raised to adulthood (18 mo: FGRI, n = 12 females, 12 males; FGRS, n = 13 females, 10 males) alongside offspring from unembolized and untreated sheep (CON; n = 12 females, 21 males). FGRI females had increased relative lean mass compared with CON but not FGRS (P < 0.05; 70.6 ± 8.2% vs. 61.4 ± 8.2% vs. 67.6 ± 8.2%), decreased abdominal adipose compared with CON and FGRS (P < 0.05; 43.7 ± 1.2% vs. 49.3 ± 0.9% vs. 48.5 ± 1.0%), increased glucose utilization compared with FGRS but not CON (P < 0.05; 9.6 ± 1.0 vs. 6.0 ± 0.9 vs. 7.6 ± 0.9 mg·kg-1·min-1), and increased ß-hydroxybutyric acid:nonesterified fatty acid ratio in response to adrenaline compared with CON and FGRS (P < 0.05; 3.9 ± 1.4 vs. 1.1 ± 1.4 vs. 1.8 ± 1.4). FGRS males were smaller and lighter compared with CON but not FGRI (P < 0.05; 86.8 ± 6.3 vs. 93.5 ± 6.1 vs. 90.7 ± 6.3 kg), with increased peak glucose concentration (10%) in response to a glucose load but few other differences. These effects of intra-amniotic IGF1 therapy on adult body composition, glucose-insulin axis function, and adrenergic sensitivity could indicate improved metabolic regulation during young adulthood in female FGR sheep.

Early-Stage Translational Research in Perinatal Medicine.

BACKGROUND: Pre-clinical research, which encompasses studies in animals and in the laboratory, has made significant contributions to the improvement of neonatal outcomes. METHODS: Here, we describe examples of how pre-clinical research can be the starting point on the journey to the development of new interventions to improve neonatal care and outcomes and discuss recent progress in ensuring methodological and ethical rigour in pre-clinical research involving animal models. RESULTS: Studies in pregnant sheep led to the serendipitous discovery that preterm lambs born after exogenous corticosteroid exposure were able to aerate their lungs. Subsequent clinical trials confirmed that antenatal corticosteroids given to women at risk of preterm delivery substantially reduce mortality and morbidity in babies born preterm. Animal research also contributed to discoveries in the mechanism of brain injury after hypoxic ischaemic encephalopathy, leading to the use of therapeutic hypothermia as an effective treatment. However, animals are sentient creatures and there are significant ethical concerns with their use in studies to benefit human health. Mandated institutional animal research ethics committees ensure adherence to ethical requirements. To provide high-quality data which can be translated into clinical research, pre-clinical research needs to follow rigorous standards of study design and reporting. The ARRIVE guidelines provide guidance for pre-clinical research similar to that provided in the CONSORT guidelines for clinical trials and are gaining acceptance among researchers and journal editors. CONCLUSION: Improved scientific rigour in the use of animal research will increase the likelihood that pre-clinical research will continue to translate into improved neonatal outcomes.

Long-Term Outcomes of Hyperglycemic Preterm Infants Randomized to Tight Glycemic Control.

OBJECTIVE: To determine whether tight glycemic control of neonatal hyperglycemia changes neurodevelopment, growth, and metabolism at school age. STUDY DESIGN: Children born very low birth weight and randomized as hyperglycemic neonates to a trial of tight vs standard glycemic control were assessed at 7 years corrected age, including Wechsler Intelligence Scale for Children Fourth Edition, Movement Assessment Battery for Children 2, visual and neurologic examinations, growth measures, dual X-ray absorptiometry, and frequently sampled intravenous glucose tolerance test. The primary outcome was survival without neurodevelopmental impairment at age 7 years. Outcomes were compared using linear regression, adjusted for sex, small for gestational age, birth plurality, and the clustering of twins. Data are reported as number (%) or mean (SD). RESULTS: Of the 88 infants randomized, 11 (13%) had died and 57 (74% of eligible children) were assessed at corrected age 7 years. Survival without neurodevelopmental impairment occurred in 25 of 68 children (37%), with no significant difference between tight (14 of 35; 40%) and standard (11 of 33; 33%) glycemic control groups (P = .60). Children in the tight group were shorter than those in the standard group (121.3 [6.3] cm vs 125.1 [5.4] cm; P < .05), but had similar weight and head circumference. Children in the tight group had greater height-adjusted lean mass (18.7 [0.3] vs 17.6 [0.2] kg; P < .01) and lower fasting glucose concentrations (84.6 [6.30] vs 90.0 [5.6] mg⋅dL-1; P < .05), but no other differences in measures of body composition or insulin-glucose metabolism. CONCLUSION: Tight glycemic control for neonatal hyperglycemia does not change survival without neurodevelopmental impairment, but reduces height, increases height-adjusted lean mass, and reduces fasting blood glucose concentrations at school age. TRIAL REGISTRATION: ACTRN: 12606000270516.

Relationship between Measures of Neonatal Glycemia, Neonatal Illness, and 2-Year Outcomes in Very Preterm Infants.

OBJECTIVES: To investigate relationships between early neonatal glycemia, neonatal characteristics, neonatal illness, and developmental outcomes in very preterm infants. STUDY DESIGN: A retrospective, observational cohort study of 443 infants born weighing <1500 g or <30 weeks of gestation, and admitted within 24 hours to National Women's Hospital, Auckland, New Zealand. Glucose variability was defined as the standard deviation around the mean after log transformation of all blood glucose concentrations. Absolute glycemic excursions in the first week were used to divide the infants into 4 groups: normoglycemic; hypoglycemic; hyperglycemic, and unstable. RESULTS: Compared with normoglycemic infants, hypoglycemic and unstable infants had lower birth weight z-scores, and hyperglycemic and unstable infants were of lower birth weight. Hypoglycemic infants had similar outcomes to normoglycemic infants. Hyperglycemic and unstable infants were less likely to survive without neonatal morbidity and less likely to survive without neurodevelopmental impairment at 2 years of age. Higher mean blood glucose concentration was seen in the hyperglycemic and unstable groups, and was associated with worse neonatal and 2-year outcomes. Greater glucose variability was seen in the hypoglycemic and unstable groups, and was associated with worse neonatal illness but not outcome at 2 years. No associations between measures of neonatal glycemia and neonatal or 2-year outcomes remained after correction for gestation, birth weight z-score, and socioeconomic status. CONCLUSIONS: In very preterm infants, measures of neonatal glycemia are markers of gestational age and intrauterine growth, and are not independent predictors of neonatal illness or outcomes at 2 years of age.