Recent interest has focused on the potential role of amylin in the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM). This 37-amino acid peptide is found in extracellular amyloid deposits in -5 0 % of pancreatic islets of patients with NIDDM and has been shown to inhibit skeletal muscle glycogen synthesis in vitro. Immunocytochemical studies have colocalized amylin and insulin within p-cell secretory granules in nondiabetic humans, provoking the following questions. Is amylin cosecreted with insulin? Are circulating amylin concentrations higher in patients with NIDDM either before or after food ingestion? To answer these questions, we developed a sensitive and specific immunoassay to measure plasma concentrations of amylin in humans. Use of this assay indicated that, in lean nondiabetic subjects, glucose ingestion resulted in an increase (P < 0.001) in the plasma concentration of amylin (from 2.03 ± 0.22 to 3.78 ± 0.39 pM) and insulin (from 48.3 ± 3.1 to 265 ± 44 pM). There was a significant correlation between the concentrations of insulin and amylin (r = 0.74, P < 0.001) and the increase in insulin and amylin concentration (r = 0.65, P < 0.005). Fasting concentrations of amylin did not differ in diabetic and weight-matched nondiabetic subjects and showed a similar pattern of change after ingestion of a mixed meal. We conclude that amylin is secreted in response to ingestion of either glucose or a mixed meal and circulates at concentrations that do not differ in patients with NIDDM and nondiabetic subjects. It remains to be determined whether amylin at physiological concentrations influences carbohydrate metabolism and if so whether its effects differ in diabetic and nondiabetic humans.

A B ST R A CT The effect of equal (1.1±0.1 g/kg body wt) amounts of glucose administered orally, or by peripheral intravenous or intraportal infusion on hepatic glucose uptake and fractional hepatic extraction of insulin and glucagon was studied in conscious dogs with chronically implanted Doppler flow probes on the portal vein and hepatic artery and catheters in the portal vein, hepatic vein, carotid artery, and superior mesenteric vein. Portal vein and hepatic vein plasma flow increased only after oral glucose administration. Arterial plasma glucose increased equally to 150-160 mg/100 ml after all three routes of glucose administration. Portal vein glucose was similar after oral (195±15 mg/100 ml) and intraportal glucose infusion (215±11 mg/100 ml) and significantly higher than after peripheral intravenous glucose. Hepatic glucose uptake after oral (68±4%) and intraportal glucose administration (65±7%) significantly exceeded that after peripheral intravenous glucose infusion (23±5%). The amount of insulin above basal presented to the liver during the 180 min after oral glucose was 7.6±1.3 U, 4.3±0.6 U after intraportal glucose, and 4.1±0.6 U after peripheral intravenous glucose. Hepatic extraction of insulin increased significantly after oral glucose (42±3 to 61±4%), but was unchanged after intraportal and peripheral intravenous glucose administration. When the portal vein glucose levels achieved during peripheral intravenous glucose infusion for 90 min were maintained by a subsequent 90-min intraportal glucose infusion, hepatic glucose uptake was significantly greater during the intraportal glucose infusion.Received for publication 7 December 1982 and in revised form 3 March 1983.Glucagon secretion was suppressed equally after oral glucose, intraportal glucose, and peripheral intravenous glucose administration; fractional hepatic extraction of that hormone, which was significantly less than that of insulin, was unchanged.These results indicate that hepatic glucose uptake is significantly greater after oral and intraportal glucose administration than after peripheral intravenous glucose infusion. This difference is not simply related to the amount of glucose or insulin presented to the liver and the increased hepatic glucose uptake did not depend solely upon the augmented fractional hepatic extraction of insulin. Hepatic extraction of insulin and hepatic glucose uptake appear to be regulated independently. INTRODUCTIONThe liver is important in glucose homeostasis. Splanchnic removal of glucose was greater after oral glucose compared with peripheral intravenous administration of glucose (1-6), but the mechanism of this effect is not clearly understood. DeFronzo et al. (5,6) implicated gut factors released after ingestion of glucose but Bergman et al. (7) reported similar hepatic uptake of glucose after intraportal glucose infusion and oral glucose administration. Abumrad et al. (8) also excluded a significant role for gut factors and concluded that both hyperglycemia and hyperinsulinemia were major factors in m...

Background: Over the past several decades, improvements in technology in the Neonatal Intensive Care Unit (NICU) have led to improved survival of preterm infants. Some studies have found that premature infants are at higher risk of behavioral problems, motor and sensory abnormalities, developmental delay, and poorer academic performance, while other studies have found no significant difference.Methods: A literature search was conducted through PubMed for articles published between January 2018 and September 2019. Studies that concentrated on preterm infants with relatively uncomplicated NICU courses and without extensive medical interventions were selected.Results: Historically, preterm infants have been found to be at increased risk for the inattentive subtype of attention deficit hyperactivity disorder (ADHD), depression, anxiety, autism spectrum disorder (ASD), avoidant personality, and anti-social personality, when compared to full term infants. However, some studies found that this difference between the two groups decrease as they enter adolescence and adulthood.Preterm infants are at increased risk for language, cognitive, sensory and motor deficits. Greater gestational age (GA) at birth and higher birth weight is associated with a lower risk of developmental delay. Cohort studies focusing on motor development showed that the degree of impairment decreased over time. Adverse childhood experiences (ACEs) have a negative correlation on multiple domains of development. The overall outcome of these infants may be influenced by socioeconomic status (SES), neonatal morbidities, demographics and parental education. Hearing and vision deficits are relatively infrequent among premature infants. A significant risk factor for hearing impairment involves the use of ototoxic agents such as gentamicin and infants with a patent ductus arteriosus (PDA).Conclusions: Preterm infants are at higher risk of adverse neurodevelopmental outcomes when compared to their full-term counter parts. However, in recent years it appears that rates of certain neurologic and developmental conditions are occurring in rates lower than historically noted. Premature individuals with possible developmental or mental health concerns should be identified early on so that interventions can be implemented immediately. Those meeting developmental milestone should continue to be monitored closely as deficits may develop later.

First-pass hepatic extraction of insulin and hepatic and peripheral contributions to hypoglycemia were compared in conscious dogs during portal infusion of insulin A1, B29 diacetyl insulin, or A1-B29 dodecoyl insulin at 7 and 14 pmol X kg-1 X min-1. The liver removed 43 +/- 2% of insulin, 12 +/- 1% of dodecoyl, and 8 +/- 1% of diacetyl insulin, in a single transhepatic circulation. The hypoglycemia induced by insulin and diacetyl insulin and the ensuing glucagon response were greater than that produced by the dodecoyl analogue. Diacetyl insulin primarily increased glucose utilization, dodecoyl insulin solely inhibited hepatic production, and insulin affected both. The lack of hepatic effect of diacetyl insulin during hypoglycemia can be ascribed to greater counterregulation, because under euglycemic clamp conditions, this analogue caused suppression of glucose production. The different patterns of hypoglycemia exhibited can be explained by the combined effects of altered distribution between the liver and peripheral tissues caused by differences in hepatic extraction, the effect of this phenomenon on the counterregulatory response, and the intrinsic biological potency of the analogues.