Estimation of whole-plant resistance to gaseous exchange independent of leaf temperature measurement

For studies into the uptake of mercury vapor by wheat (Triticum aestivum), a simple theory and plant chamber were employed to estimate total leaf resistance of whole plants to water vapor exchange. The estimates were independent of leaf temperature, for which mean values were indirectly determined. The approach involved the measurement, at steady-state conditions, of the net change in water vapor flux per unit of leaf surface (Δq_v) in response to a small induced change in absolute humidity (ΔC_a). Assuming that total leaf resistance (r_l) was constant and that change in leaf temperature (T_l) was negligible, total leaf resistance was calculated from the equation, [Formula: see text]     

Burn syndactyly.

When the entire digital web space has been destroyed by burn scarring and there is a contracture of the volar aspect of the web as well as the dorsum, Z-plasties and skin grafts alone seldom produce a satisfactory web space. During the past 3 years, for the release of 46 contracted web spaces in 20 burned patients, we have turned a rectangular flap from the dorsal surface of the web through into an inverted-T incision in the palm. The adjacent sides of the defects have been skin grafted. In all these patients, we obtained satisfactory release of the contracture and restoration of the web space.     

The isolation of peptides by high-performance liquid chromatography using predicted elution positions

This paper describes the derivation and use of predictive retention coefficients for the reversed-phase high-performance liquid chromatography of peptides. The use of predicted elution positions in the isolation of peptides is illustrated by two examples where peptides, whose existence was postulated from cDNA sequence data, have been successfully isolated. The combination of the powerful chromatographic technology and the ability to predict the elution positions of peptides based on their composition provides a very potent method for the isolation of peptides from biological tissues.     

Inhibition of mitosis in fertilized sea urchin eggs by inhibition of the cyclic AMP-dependent protein kinase

Inhibition of cAMP-dependent protein kinase activity by microinjection of a specific physiologic protein inhibitor into sea urchin eggs inhibits the first cleavage after fertilization. Inhibition apparently occurs at some time prior to or during formation of the mitotic spindle. Measurement of the total protein kinase activity of sea urchin egg homogenates after fertilization showed that cAMP-dependent phosphorylation increases after fertilization and then declines prior to or at the time of the first cleavage. It is concluded that a cAMP-dependent phosphorylation plays a significant role in events leading to regulation of mitotic spindle assembly.     

Cytologic features of pilocytic astrocytoma in cerebrospinal fluid specimens

OBJECTIVE: To illustrate the cytomorphologic features of pilocytic astrocytoma (PA) in cerebrospinal fluid (CSF) samples. STUDY DESIGN: A search of records from 1965 to 2001 was performed to identify all patients with a diagnosis of PA in whom CSF samples were examined. Slides from CSF samples originally reported as atypical, suspicious or positive were reviewed and the cytomorphologic features assessed. RESULTS: Two hundred ninety-three patients with a diagnosis of PA were identified. Of these, 44 had a total of 65 cytologic preparations of CSF. In 34 patients (77.2%) the CSF cytology was negative, in 5 (11.4%) either atypical or suspicious, and in 5 (11.4%) positive for neoplastic cells. The tumors in the 5 positive cases arose in the cerebellar hemispheres (2), cerebellar vermis (1), thalamus (1) and tectum with extension into the fourth ventricle (1). All positive samples were hypercellular, with an average of 5 cell clusters per case (range, 3-11). The clusters were composed of cohesive epithelioid cells with a mean of 8 cells per cluster. In addition, some cases had scattered, isolated, single cells. These single neoplastic cells had prominent, hairlike cytoplasmic processes. The cells in clusters appeared epithelioid, with oval nuclei, mild nuclear pleomorphism, finely or slightly coarsely granular chromatin and cobweblike cytoplasm. CONCLUSION: The cytomorphologic features of PAs recapitulate their histologic characteristics. The tumor cells are recognizable in CSF samples and readily distinguishable from histiocytes and ependymal cells.     

A phylogeny of the families of Scarabaeoidea (Coleoptera)

Abstract. A study, based on examination of thirteen scarabaeoid families, was made of 134 adult and larval characters from the following character suites: 105 adult characters of the antennae, eye, epipharynx, mandible, maxillae, labium, tentorium, trochantin, procoxae, mesocoxae, mesothoracic spiracles, hind wing articulation, hind wing base, hind wing venation, hind wing folding, abdominal sternites, abdominal spiracles, male genitalia, ovarioles and karyotype; twenty larval characters of the antennae, fronto-clypeal suture, stemmata, labial palpi, maxillae, mandibles, legs, stridulatory apparatus, spiracles and ecdysial process; and nine adult and larval biological characters. In order to assess the reliability of different characters in resolving scarabaeoid family relationships, six data sets were subjected to cladistic analysis: the total evidence character set (134 characters), restricted adult character set (thirty-two characters, not including those of the wings), wing character set (seventy-three characters), larval character set (twenty characters), biological character set (nine characters) and re-coded Howden (1982) character set (thirty-nine characters). The complete character set and wing character set both produced phylograms with all nodes resolved; the restricted adult data set, larval data set, Howden (1982) data set and biological data set produced phylograms with diminishing levels of node resolution. The reconstructed phylogeny, from the preferred phylogram of the total evidence character set, shows that the Scarabaeoidea comprises three major lineages; a glaresid, passalid and scarabaeid lineage. The glaresid lineage consists only of the Glaresidae. The passalid lineage comprises two major lines; a glaphyrid line (containing Glaphyridae, Passalidae, Lucanidae, Diphyllostomatidae, Trogidae, Bolboceratidae and Pleocomidae) and a geotrupid line (containing Geotrupidae, Ochodaeidae, Ceratocanthidae and Hybosoridae). The scarabaeid lineage contains those taxa traditionally included within the Scarabaeidae (Aphodiinae, Scarabaeinae, Orphninae, Melolonthinae, Acoma, Chasmatopterinae, Hopliinae, Oncerinae, Rutelinae, Dynastinae, Trichiinae, Cetoniinae and Valginae).     

Targeting conserved water molecules: Design of 4-aryl-5-cyanopyrrolo[2,3-d]pyrimidine Hsp90 inhibitors using fragment-based screening and structure-based optimization

Inhibitors of the Hsp90 molecular chaperone are showing promise as anti-cancer agents. Here we describe a series of 4-aryl-5-cyanopyrrolo[2,3-d]pyrimidine ATP competitive Hsp90 inhibitors that were identified following structure-driven optimization of purine hits revealed by NMR based screening of a proprietary fragment library. Ligand-Hsp90 X-ray structures combined with molecular modeling led to the rational displacement of a conserved water molecule leading to enhanced affinity for Hsp90 as measured by fluorescence polarization, isothermal titration calorimetry and surface plasmon resonance assays. This displacement was achieved with a nitrile group, presenting an example of efficient gain in binding affinity with minimal increase in molecular weight. Some compounds in this chemical series inhibit the proliferation of human cancer cell lines in vitro and cause depletion of oncogenic Hsp90 client proteins and concomitant elevation of the co-chaperone Hsp70. In addition, one compound was demonstrated to be orally bioavailable in the mouse. This work demonstrates the power of structure-based design for the rapid evolution of potent Hsp90 inhibitors and the importance of considering conserved water molecules in drug design.