The myosuppressin structure-activity relationship for cardiac contractility and its receptor interactions support the presence of a ligand-directed signaling pathway in heart.

The structural conservation and activity of the myosuppressin cardioinhibitory peptide across species suggests it plays an important role in physiology, yet much remains unknown regarding its signaling. We previously reported Drosophila melanogaster myosuppressin (dromyosuppressin, DMS; TDVDHVFLRF-NH2) decreases cardiac contractility through a G protein-coupled receptor, DMS-R2. Our study showed the DMS N-terminus amino acids influence its structure-activity relationship (SAR), yet how they act is not established. We predicted myosuppressin N-terminal amino acids played a role in signaling. Here, we tested our hypothesis in the beetle, Zophobas atratus, using a semi-isolated heart bioassay to explore SAR in a different Order and focus on cardiac signaling. We generated a series of myosuppressin truncated analogs by removing the N-terminal residue and measuring the activity of each structure on cardiac contractility. While DVDHVFLRF-NH2 decreased cardiac contractility, we found VDHVFLRF-NH2, DHVFLRF-NH2, and HVFLRF-NH2 increased activity. In contrast, VFLRF- NH2 decreased activity and FLRF-NH2 was inactive. Next, we analyzed molecular docking data and found the active truncated analogs interacted with the 3-6 lock in DMS-R2, the myosuppressin cardiac receptor, disrupting the salt bridge between H114 and E369, and K289 and Q372. Further, the docking results showed the inhibitory effect on contractility may be associated with contact to Y78, while the analogs that increased contractility lacked this interaction. The data from our study demonstrated N-terminal amino acids played a role in myosuppressin activity and signaling suggesting the cardiac receptor can be targeted by biased agonists. Our myosuppressin cardiac contractility data and predicted receptor interactions describe the presence of functional selectivity in a ligand-directed signaling pathway in heart.

Comparing coordination uranyl(vi) complexes with 2-(1H-imidazo[4,5-b]phenazin-2-yl)phenol and derivatives.

Four derivatives of 2-(1H-imidazo[4,5-b]phenazin-2-yl)phenol have been synthesized and characterized structurally using X-ray crystallography. Coordination complexes with uranyl (UO22+) and copper (Cu2+) were prepared and absorption/emission spectra detailed. We observed increased fluorescence upon uranyl binding, in stark contrast to rapid quenching observed with the addition of copper. These phenomena have been further examined by DFT computational methods.

A prospective study of treatments for adult-onset divergence insufficiency-type esotropia.

PURPOSE: To describe 10-week and 12-month outcomes following treatment for divergence insufficiency-type esotropia in adults. METHODS: In this prospective observational study, 110 adults with divergence insufficiency-type esotropia, with a distance esodeviation measuring 2Δ to 30Δ and at least 25% larger at distance than near, and binocular diplopia present at least "sometimes" at distance, were enrolled at 28 sites when initiating new treatment. Surgery, prism, or divergence exercises/therapy were chosen at the investigator's discretion. Diplopia was assessed at enrollment and at 10-week and 12-month outcome examinations using a standardized diplopia questionnaire (DQ). Success was defined as DQ responses of "rarely" or "never" when looking straight ahead in the distance, with no alternative treatment initiated. RESULTS: Of the 110 participants, 32 (29%) were prescribed base-out prism; none had received prior treatment for esotropia. Success criteria were met by 22 of 30 at 10 weeks (73%; 95% CI, 54%-88%) and by 16 of 26 at 12 months (62%; 95% CI, 41%-80%). For the 76 (68%) who underwent strabismus surgery (82% of whom had been previously treated with prism), success criteria were met by 69 of 74 at 10 weeks (93%; 95% CI, 85%-98%) and by 57 of 72 at 12 months (79%; 95% CI, 68%-88%). CONCLUSIONS: In this study cohort, both base-out prism as initial therapy and strabismus surgery (usually following prism) were successful in treating diplopia for most adults with divergence insufficiency-type esotropia when assessed during the first year of follow-up.

Genetic diversity and gene flow in collapsed and healthy abalone fisheries.

Overexploitation of marine species invariably results in population decline but can also have indirect effects on ecological processes such as larval dispersal and recruitment that ultimately affect genetic diversity and population resilience. We compared microsatellite DNA variation among depleted and healthy populations of the black-lip abalone Haliotis rubra from Tasmania, Australia, to determine if over-fishing had affected genetic diversity. We also used genetic data to assess whether variation in the scale and frequency of larval dispersal was linked to greater population decline in some regions than in others, and if larval dispersal was sufficient to facilitate natural recovery of depleted populations. Surprisingly, allelic diversity was higher in depleted populations than in healthy populations (P < 0.05). Significant subdivision across hundreds of metres among our sampling sites (F(ST) = 0.026, P < 0.01), coupled with assignment tests, indicated that larval dispersal is restricted in all regions studied, and that abalone populations across Tasmania are largely self-recruiting. Low levels of larval exchange appear to occur at the meso-scale (7-20 km), but age estimates based on shell size indicated that successful migration of larvae between any two sites may happen only once every few years. We suggest that genetic diversity may be higher in depleted populations due to the higher relative ratio of migrant to self-recruiting larvae. In addition, we expect that recovery of depleted abalone populations will be reliant on sources of larvae at the meso-scale (tens of km), but that natural recovery is only likely to occur on a timescale unacceptable to fishers and resource managers.

Solid state π-π stacking and higher order dimensional crystal packing, reactivity, and electrochemical behaviour of salphenazine actinide and transition metal complexes.

Condensation of a 2,3-diaminophenazine or 2,3-diamino-2-quinoxalinol with two equivalents of 3,5-ditertbutylsalicylaldehyde affords new Schiff base ligands. Here, we describe and compare the synthesis, UV-Vis, electrochemical, solution, and solid state behaviour of the free base, salphenazine ligand [L(I)], and M[L(I)] complexes, where M = UO2(vi), Cu(ii), VO(iv), Zn(ii), Co(ii), and Ni(ii). The change in π-overlap and π-stacking between molecules and long-range ordering of the solid-state structure is vastly different depending on the size and electronic character of the metal. A sterically constrained µ-oxo Fe(iii) dimer complex is also reported.

Synthesis, structural characterization, electronic spectroscopy, and microfluidic detection of Cu(+2) and UO2(+2) [di-tert-butyl-salphenazine] complexes.

Metal templation by condensation of 2,3-diaminophenazine with 3,5-di-tert-butyl-2-hydroxybenzaldehyde around the metal centers [M = Cu(II), and UO2(VI)] affords a new class of M[di-tert-butyl salphenazine] metal complexes. Reported here is the synthesis, single crystal X-ray structural characterization, electronic spectroscopy, and microfluidic detection of the formation of these M[di-tert-butyl sal-phenazine] complexes.

Widespread anatomical projections of the serotonergic modulatory neuron, CB1, in Aplysia.

Although sensitization-related changes in the neural circuitry of withdrawal reflexes in Aplysia are well studied, relatively few studies address the organization of the modulatory components of sensitization. In particular, it is not known whether individual modulatory loci can simultaneously influence multiple reflex circuits. There is, however, evidence that a single modulatory transmitter, serotonin, plays a pivotal role in facilitating different reflex circuits during sensitization. Furthermore, it is known that activation of a pair of serotonergic neurons, the CB1s, produces heterosynaptic facilitation of the sensorimotor connections of one of these reflex circuits. These data together raise the possibility that the CB1s may produce sensitizing changes in the neural elements of multiple reflex systems simultaneously. In the present study, we utilized immunocytochemistry and intracellular labeling to obtain anatomical evidence of CB1's possible role in modulating multiple reflex circuits. We found that two distinct neurons satisfy previously published physiological criteria for CB1. One of these, CB1, is immunoreactive to serotonin. The second cell, here named CB2, has a different neuroanatomy and is not serotonin immunoreactive. Focusing on CB1, we found (1) profuse fine processes given off by its axons in the posterior neuropil of the cerebral ganglion, (2) extensive branching and fine processes in the pleural ganglion, and (3) a branch of CB1 that projects into the pedal ganglion. These three observations are consistent with the hypothesis that, in addition to its already established role in modulating the siphon withdrawal circuit, CB1 may also modulate synaptic connections between (1) the sensory and motor neurons of the tentacle withdrawal reflex (2) the sensory neurons and interneurons of the tail and tail-elicited siphon withdrawal reflex, and (3) the sensory and motor neurons of the tail withdrawal reflex. These observations support further physiological investigations of a possible global role of CB1 in modulating the tail and tentacle withdrawal reflexes.

Gammarus lacustris harboring Polymorphus paradoxus show altered patterns of serotonin-like immunoreactivity.

The pattern of serotonin-like immunoreactivity in the central nervous system of individuals of the amphipod Gammarus lacustris harboring polymorphid cystacanths was compared to the pattern seen in individuals not infected with acanthocephalans. Ventral nerve cords from both parasitized and nonparasitized amphipods showed the same bilateral pair of immunoreactive cell bodies in the third thoracic ganglion. Significant differences were noted in the fine structure of these cell bodies, with nerve cords from Polymorphus paradoxus-parasitized amphipods showing a greater number of bright spots or localized points of storage of serotonin. The results of this study indicate that infection of G. lacustris by cystacanths of P. paradoxus, but not P. marilis, is correlated with changes in the anatomy of the serotonergic neurons of the amphipod's central nervous system.

Parasite-altered behavior in a crustacean intermediate host: field and laboratory studies.

The effects of the acanthocephalan parasite Pomphorhynchus laevis on the behavior of its crustacean intermediate host, the amphipod Echinogammarus stammeri, were studied. A drift study revealed that infected amphipods were disproportionately represented in drift samples taken throughout a 24-hr period; infection with more than 1 parasite enhanced this effect. Infection also interacted with the daily timing of drift, with parasitized amphipods beginning to drift earlier in the evening. Two distinct behaviors quantified in laboratory settings may play a role in this increased drifting behavior: parasitized amphipods showed (1) an increased preference for an illuminated environment and (2) increased activity in comparison to nonparasitized conspecifics. These results are consistent with previous studies on the effects of P. laevis on another amphipod host, Gammarus pulex, and provide new data on the activity level of P. laevis-infected amphipods.

Posttraumatic stress two years after the Oklahoma City bombing in youths geographically distant from the explosion.

This article describes Posttraumatic Stress Disorder (PTSD) symptomatology in 69 sixth-grade youths who resided within 100 miles of Oklahoma City at the time of the 1995 bombing of the Alfred P. Murrah Federal Building. These youths neither had any direct physical exposure nor personally knew anyone killed or injured in the explosion. A survey conducted two years after the bombing assessed exposure, PTSD symptoms, and functioning. PTSD symptom frequency was measured with the Impact of Event Scale--Revised. Our BCD criteria for defining PTSD caseness was modeled after DSM-IV B, C, and D criteria requiring one reexperiencing, three avoidance/numbing, and two arousal symptoms for diagnosis. Those who met our BCD criteria had significantly higher PTSD symptom scores than those who did not. Both increased mean PTSD symptom score and meeting our caseness definition were associated with increased functioning difficulties. Media exposure and indirect interpersonal exposure (having a friend who knew someone killed or injured) were significant predictors of symptomatology. These findings suggest that children geographically distant from disaster who have not directly experienced an interpersonal loss report PTSD symptoms and functional impairment associated with increased media exposure and indirect loss.

The role of exposure in posttraumatic stress in youths following the 1995 bombing.

This study investigated the relative impact of various forms of exposure to the 1995 Oklahoma City bombing in middle and high school students seven weeks after the incident. We assessed 3210 youths with an instrument that probed for physical, television, and emotional exposure to the bombing and subsequent posttraumatic stress symptomatology and television reactivity. The majority of youths were exposed through physical proximity--hearing and/or feeling the blast--and through television viewing. These types of exposure, as well as emotional exposure, constituted important variables in the development of posttraumatic stress symptoms and television reactivity. Youths with immediate family casualties were more symptomatic than those without.

Conserved residues in RF-NH2 receptor models identify predicted contact sites in ligand-receptor binding.

Peptides in the RF-NH2 family are grouped together based on an amidated dipeptide C terminus and signal through G-protein coupled receptors (GPCRs) to influence diverse physiological functions. By determining the mechanisms underlying RF-NH2 signaling targets can be identified to modulate physiological activity; yet, how RF-NH2 peptides interact with GPCRs is relatively unexplored. We predicted conserved residues played a role in Drosophila melanogaster RF-NH2 ligand-receptor interactions. In this study D. melanogaster rhodopsin-like family A peptide GPCRs alignments identified eight conserved residues unique to RF-NH2 receptors. Three of these residues were in extra-cellular loops of modeled RF-NH2 receptors and four in transmembrane helices oriented into a ligand binding pocket to allow contact with a peptide. The eighth residue was unavailable for interaction; yet its conservation suggested it played another role. A novel hydrophobic region representative of RF-NH2 receptors was also discovered. The presence of rhodopsin-like family A GPCR structural motifs including a toggle switch indicated RF-NH2s signal classically; however, some features of the DMS receptors were distinct from other RF-NH2 GPCRs. Additionally, differences in RF-NH2 receptor structures which bind the same peptide explained ligand specificity. Our novel results predicted conserved residues as RF-NH2 ligand-receptor contact sites and identified unique and classic structural features. These discoveries will aid antagonist design to modulate RF-NH2 signaling.

Histologic and immunofluorescence study of cutaneous porphyrias.

We reviewed the histologic and direct immunofluorescence findings in skin biopsy specimens from 24 patients with cutaneous porphyrias. The histopathologic changes were characterized by cell-poor subepidermal bullae, festooning of dermal papillae, thickening and hyalinization of dermal blood vessel walls, dermal sclerosis, and a mild perivascular infiltration of mononuclear cells in the upper dermis. The characteristic pattern on direct immunofluorescence testing was fluorescence of thickened doughnut-like blood vessels in the upper dermis, reflecting deposition of immunoglobulins and C3, and deposition of immunoglobulins or C3 or both at the dermal-epidermal junction in most cases. These findings are characteristic but not specific for the porphyrias; they may also be observed in the pseudoporphyria syndromes and in other clinical settings. However, the immunopathologic findings are distinctive enough to be useful in differentiating the porphyrias and pseudoporphyria syndromes from other subepidermal bullous diseases such as epidermolysis bullosa acquisita and bullous pemphigoid. The most important diagnostic test in the evaluation of the cutaneous porphyrias still is measurement of porphyrins in urine, stool, and blood.

Neonatal lupus erythematosus syndrome.

Three cases of neonatal lupus erythematosus (NLE) syndrome are described. The key diagnostic sign is the erythematous and annular clinical appearance of lesions. The histopathologic findings may be subtle in NLE syndrome compared with discoid or subacute cutaneous lupus erythematosus. Direct immunofluorescence testing may be useful in supplementing the histopathologic evaluation. Detection of immunoglobulins, complement, or both at the basement membrane zone in lesional skin by immunofluorescence occurs in approximately half of cases; a negative study does not preclude the diagnosis of NLE syndrome. Clinical and serologic evaluation of both the infant and the mother are important in establishing a diagnosis of NLE syndrome, particularly when histopathologic findings are subtle.

Schnitzler's syndrome.

We report on a case of Schnitzler's syndrome, focusing on pattern of bone involvement and its differential diagnosis.

Transitional cell carcinoma of the fossa navicularis of the male urethra.

We report a case of transitional cell carcinoma arising in the fossa navicularis, a portion of the male urethra ordinarily lined by squamous epithelium. This is the third reported case of transitional cell carcinoma of the distal urethra. The neoplasm metastasized to superficial inguinal lymph nodes.

Anti-Jka, -C, and -E in a single patient, initially demonstrable only by the manual hexadimethrine bromide (Polybrene) test, with incompatibilities confirmed by 51Cr-labeled red cell studies.

Published reports have confirmed the superior sensitivity of the manual hexadimethrine bromide (Polybrene) test (MPT) for demonstrating many alloantibodies in vitro; however, the clinical significance of alloantibodies demonstrable exclusively by MPT has not been shown conclusively. A patient with macroglobulinemia experienced chills, fever, hemoglobinemia, and hemoglobinuria following the transfusion of 1 unit of red cells (RBCs) shown to be compatible by the low-ionic-strength antiglobulin (LIS-AG) method. Serologic investigation was negative. Intravascular hemolysis occurred with a second "compatible" unit. Serologic studies were again negative by LIS-AG and ficin-AG methods, but revealed anti-Jka by MPT. Both donors were Jk(a+b-), and 51Cr studies of the second donor's RBCs revealed a t1/2 of less than 30 minutes, with marked intravascular hemolysis. A LIS-AG-compatible Jk(a-) unit was transfused uneventfully, but with no rise in hematocrit. MPT next revealed anti-C; subsequent 51Cr studies with the Jk(a-), Cc donor's RBCs showed a 51Cr t1/2 of 100 minutes with slight intravascular lysis. Four transfusions of Jk(a-), C- blood were uneventful, but 5 days later the patient's hemoglobin declined. The following day, anti-E was demonstrable exclusively by MPT. 51Cr-labeled Jk(a-), C-, E- RBCs had normal 24-hour survival. The patient's hemoglobin rose to 11 g per dl following transfusions of Jk(a-), C-, E- RBCs, and he was discharged. In vitro studies employing the patient's purified IgM paraprotein revealed no interference with alloantibody binding or detection.

Drug-induced linear IgA bullous dermatosis: report of six cases and review of the literature.

BACKGROUND: Linear IgA bullous dermatosis (LABD) is an autoimmune subepidermal blistering disease that may be associated with drug exposure. OBJECTIVE: Our purpose was to compare the clinical, pathologic, and immunofluorescence findings in drug-induced LABD with those in the idiopathic type. METHODS: Six patients with an acute drug eruption were identified who had linear IgA deposition at the basement membrane zone (BMZ). Lesional tissue was examined by brightfield microscopy, and perilesional tissue was examined by direct immunofluorescence (DIF). The presence of circulating BMZ antibody was assayed by indirect immunofluorescence (IIF) on monkey esophagus (ME) and salt-split human skin (SS). RESULTS: Histopathologic examination showed subepidermal bullae with varying numbers of inflammatory cells. DIF showed linear IgA at the BMZ; three of the patients also had weak deposition of C3 at the BMZ. Serum from five patients was studied by IIF. One patient had circulating IgA BMZ antibodies in a titer of 1:80 on ME, localized to the dermal side on SS. All patients were free of lesions within 5 weeks after discontinuation of the drug. CONCLUSION: Drug-induced LABD is a self-limited eruption characterized by linear deposition of IgA without IgG at the BMZ. Most patients lack circulating antibodies. The distribution of lesions and the course of the disease differ from those of idiopathic LABD.