Antifeedants for adult western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), were isolated and identified from inflorescences of cultivated sunflower, Helianthus annuus L., and Canadian goldenrod, Solidago canadensis L. Fractionation of floral principles was guided by a bioassay using treated disks from squash flowers containing cucurbitacins, potent rootworm feeding stimulants. Sequential surface extraction of sunflower inflorescences followed by solvent partitioning of residues yielded ethyl acetate solubles rich in antifeedant activity. Further chromatography on Toyopearl TSK HW-40F and/or silica gel gave over 65 compounds, from which 15 active structures were identified. Feeding deterrency decreased in order of sesquiterpenes >> diterpenes > flavonoids > dicaffeoylquinic acids, of which the most potent were sesquiterpene lactone angelates including argophyllin A and 3-methoxyniveusin A, the diterpenoic acids grandifloric acid and its 15-angelate, and the flavonoids nevadensin and quercetin beta-7-O-glucoside. Similarly, kaempferol was identified as a weak antifeedant from Canadian goldenrod. Two of the electrophilic germacranolide angelates with 4,5-unsaturation, when injected into rootworm adults, gave neurotoxic symptoms (hyperexcitability, enhanced egg expulsion, tarsal tetany) similar to picrotoxinin, a sesquiterpene lactone epoxide known to act on the gamma-aminobutyric acid-gated chloride channel. These neurotoxic antifeedants may explain both the seven-fold decreased tolerance of western corn rootworm to aldrin and its decreased longevity when fed on floral tissues of sunflower in comparison to corn. Relevance of these results to other herbivore-phytochemical associations, particularly those with chrysomelids, will be discussed.

Feeding deterrents for adult western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), some of which were neurotoxic, were isolated from inflorescences of cultivated sunflower by chromatography of ethyl acetate solubles on Toyopearl TSK HW-40F and silica gel. Antifeedants, as measured through a consumption bioassay with treated squash flower disks containing cucurbitacin feeding stimulants for rootworm, were characterized by UV, H-1 and C-13 NMR, and EIMS. Fractionation by these methods gave 15 active principles of which argophyllin A and 3-O-methylniveusin A, both sesquiterpene lactone angelates, were the most potent. Feeding deterrency decreased in the order sesquiterpenes >> diterpenes > flavonoids > dicaffeoylquinic acids. The diterpenoic acid grandifloric acid and its 15-angelate and the flavonoids nevadensin and quercetin-beta-7-O-glucoside were much poorer antifeedants, although more abundant components of sunflower. Synergistic or antagonistic interactions for combinations of deterrents within or between the sesquiterpene, diterpene, and flavonoid classes were not found, indicating sunflower antifeedants act jointly in an additive fashion. The highly active antifeedant germacranolide angelates exhibit structural features and injected symptoms in adult rootworm similar to picrotoxinin, a gamma-aminobutyric acid gated chloride channel antagonist, suggesting a link between sesquiterpene neurotoxicity and GABA.

To provide normative data, we measured anogenital distances in 115 infants of 25 to 42 weeks gestational age and 10 pregnant women, including anus to fourchette (AF), anus to base of the clitoris (AC), and fourchette to base of the clitoris (FC). All infant measurements showed positive and significant correlations with body surface area, weight, length, and gestational age (P less than 0.001). However, the anogenital ratio (AF/AC) followed a normal distribution and did not correlate with any of the anthropometric variables or age. Mean (+/- SD) value in infants was 0.37 +/- 0.07, and in adults, 0.36 +/- 0.07. An anogenital ratio greater than 0.50 falls outside the 95% confidence limits, suggests labioscrotal fusion, and indicates a need for further evaluation. Because it is independent of body size and gestational age, the anogenital ratio should be useful in diagnosing androgen-induced labioscrotal fusion in both premature and full-term female infants.

To establish normal values for gastric secretory function in preterm infants, we studied 34 healthy preterm infants once a week during hospitalization. Basal acid output, pentagastrin-stimulated acid output, fasting serum gastrin, and fasting serum pancreatic polypeptide were measured during each study. Basal acid output at 1 week of age was 12 mumol/kg/hr, increasing over the first 4 weeks to 30 mumol/kg/hr. Administration of pentagastrin 6 micrograms/kg subcutaneously increased acid output in all age groups. Pentagastrin-stimulated acid output at 1 week was 21 mumol/kg/hr, increasing over the first 4 weeks to 44 mumol/kg/hr. Acid secretion did not change significantly over the next 4 to 6 weeks. Fasting serum gastrin concentration was stable over the first 6 weeks of life, but doubled during the end of the second month. Pancreatic polypeptide was found at low levels throughout the study. These studies confirm that the majority of healthy preterm infants secrete acid in quantity sufficient to maintain the gastric pH less than or equal to 4, providing a barrier to bacteria and protein antigens.

To determine the effect of an intravenous amino acid infusion on gastric acid secretion we measured acid secretion in 7 enterally fed chronically ill infants (age 3-7 mo, weight 2-6 kg) requiring intravenous supplements. Amino acids were emitted from intravenous solutions for 8 hr, and enteral feedings were omitted for 6 hr prior to studies on 2 consecutive days. On day 1 basal acid output (BAO) was 28±5 μmoles/kg.hr, and post-pentagastrin (6 μg/kg, s.c.) maximal acid output (MAO) was 99±20 μmoles/kg.hr. On day 2 BAO was determined and then acid output was measured for 4 hr following addition of amino acids (Aminosyn, Abbott) to the intravenous solution. The rate of amino acid infusion was 0.15 gm/kg.hr. Serum gastrin was measured by radioimmunoassay before and after amino acid infusion. All results were expressed as mean ± SEM.