Publications by authors named "Aldrich J"

Rationale: Low-dose radiation from computed tomography (CT) may increase the risk of certain cancers, especially in children.

Objective: We sought to estimate the excess all-cause and cancer-specific mortality, which may be associated with repeated CT scanning of patients with cystic fibrosis (CF).

Methods: The radiation dose was calculated for a published CF surveillance CT scanning protocol of biennial CT scans, and the risk per scan was estimated using atom-bomb survivor data.

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The purpose of this investigation was to determine the effects of an activated charcoal (AC) suspension containing propylene glycol and glycerol on serum osmolality, osmolal gap, and lactate concentration in dogs. Six healthy adult dogs were administered 4 g/kg AC in a commercially available suspension that contained propylene glycol and glycerol as vehicles. Blood samples were taken before and 1, 4, 6, 8, 12, and 24 hours after the administration of the test suspension.

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Objective: To compare direct measurements of canine oxyhemoglobin (HbO2) saturation and blood oxygen content (ContO2) in healthy dogs with analyzer-calculated values derived by use of a human HbO2 relationship and with hand-calculated values derived by use of a canine HbO2 relationship.

Animals: 17 healthy dogs.

Procedure: 3-mL samples of heparinized arterial and jugular venous blood were collected from each dog.

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Article Synopsis
  • The study focuses on evaluating the performance of display systems in a large hospital, using criteria set by the American Association of Physicists in Medicine (AAPM) for primary and secondary displays.
  • A telescopic photometer was utilized to measure luminance and contrast ratios under different lighting conditions, revealing that only about half of the displays met the AAPM's minimum standards in low light, while none met the criteria in ambient light.
  • The article also addresses the challenges faced in enhancing display performance and calibration.
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The cyclic dynorphin A analogue [N(alpha)-benzylTyr(1),cyclo(D-Asp(5),Dap(8))]dynorphin A-(1-11)NH(2) (Dap = 2,3-diaminopropionic acid) exhibits nanomolar affinity (30 nM) and high selectivity (K(i) ratio (kappa/mu/delta) = 1/194/330) for kappa-opioid receptors. This analogue antagonizes dynorphin A-(1-13)NH(2) at kappa-opioid receptors in the adenylyl cyclase assay (K(B) = 84 nM). This is the first dynorphin A-based antagonist with modifications in the C-terminal "address" domain that alter efficacy and thus represents a novel selective kappa-opioid receptor antagonist.

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Objective: Much concern has been expressed over the radiation doses and potential harm from x-ray examinations. However, there have been few longitudinal studies in North America. A survey of doses from radiological examinations in Canada was last carried out in 1995.

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Several peptides, including penetratin and Tat, are known to translocate across the plasma membrane. Dynorphin opioid peptides are similar to cell-penetrating peptides in a high content of basic and hydrophobic amino acid residues. We demonstrate that dynorphin A and big dynorphin, consisting of dynorphins A and B, can penetrate into neurons and non-neuronal cells using confocal fluorescence microscopy/immunolabeling.

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The purpose of this project was to collate canine cardiopulmonary measurements from published and unpublished studies in our laboratory in 97 instrumented, unsedated, normovolemic dogs. Body weight; arterial and mixed-venous pH and blood gases; mean arterial, pulmonary arterial, pulmonary artery occlusion, and central venous blood pressures; cardiac output; heart rate; hemoglobin; and core temperature were measured. Body surface area; bicarbonate concentration; base deficit; cardiac index; stroke volume index, systemic and pulmonary vascular resistance indices; left and right cardiac work indices; alveolar partial pressure of oxygen (pO2) ; alveolar-arterial pO2 gradient (A-apO2); arterial, mixed-venous, and pulmonary capillary oxygen content; oxygen delivery; oxygen consumption; oxygen extraction; venous admixture; arterial and mixed-venous blood CO2 contents; and CO2 production were calculated.

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We previously reported that the novel dynorphin A (Dyn A, Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln) analog arodyn (Ac[Phe(1,2,3),Arg(4),d-Ala(8)]Dyn A-(1-11)NH(2), Bennett, M.A., Murray, T.

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Study Objective: To establish the pharmacokinetics of stavudine within the cerebrospinal fluid (CSF) of patients infected with human immunodeficiency virus (HIV).

Design: Pharmacokinetic study.

Setting: General clinical research center.

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Global assessment of the emergency patient.

Vet Clin North Am Small Anim Pract

March 2005

The approach to the global assessment of the emergency patient must bean organized, focused, and efficient pursuit of identification all the patient's problems in the order of their importance to survival. The format of the problem-oriented approach serves as a guide. The patient's history and physical examination results serve as the database for global assessment;they are the core of emergency practice.

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Gas chromatographic-electroantennographic detection (G3C-EAD) experiments showed that antennae of males and females of the goldeneyed lacewing, Chrysopa oculata Say (Co. = Chrysopa), consistently responded to four compounds extracted from the abdominal cuticle of males:nonanal, nonanol, nonanoic acid, and (1R*,2S*,5R*,8R*)-iridodial. These compounds were not detected from abdominal cuticle of females.

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Dynorphins, endogenous opioid neuropeptides derived from the prodynorphin gene, are involved in a variety of normative physiologic functions including antinociception and neuroendocrine signaling, and may be protective to neurons and oligodendroglia via their opioid receptor-mediated effects. However, under experimental or pathophysiological conditions in which dynorphin levels are substantially elevated, these peptides are excitotoxic largely through actions at glutamate receptors. Because the excitotoxic actions of dynorphins require supraphysiological concentrations or prolonged tissue exposure, there has likely been little evolutionary pressure to ameliorate the maladaptive, non-opioid receptor mediated consequences of dynorphins.

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Five mosquito trapping systems were evaluated in a large wildlife research center containing extensive and diverse mosquito-breeding habitat. The systems evaluated included Centers for Disease Control (CDC) New Standard Miniature Light traps with and without CO2 (dry ice), CDC gravid traps, partially open 1.8-m3 cages, and Fay-Prince traps baited with CO2.

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Objective: To determine incidence of and possible risk factors for catheter-associated urinary tract infection (UTI) among dogs hospitalized in an intensive care unit and compare results of bacterial culture of urine samples with results of bacterial culture of catheter tips.

Design: Prospective study.

Animals: 39 dogs.

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Two compounds that together constitute the female sex pheromone of the pink hibiscus mealybug (PHM), Maconellicoccus hirsutus, were isolated, identified, and synthesized. They are (R)-2-isopropenyl-5-methyl-4-hexenyl (S)-2-methylbutanoate [common name is (R)-lavandulyl (S)-2-methylbutanoate] and [(R)-2,2-dimethyl-3-(1-methylethylidene)cyclobutyl]methyl (S)-2-methylbutanoate [which we refer to as (R)-maconelliyl (S)-2-methylbutanoate]. Maconelliol is an unusual cyclobutanoid monoterpene, and its structure has been established by enantioselective synthesis from precursors of known structure and configuration.

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A series of potential affinity label derivatives of the amphibian opioid peptide [D-Ala2]deltorphin I were prepared by incorporation at the para position of Phe3 (in the 'message' sequence) or Phe5 (in the 'address' sequence) of an electrophilic group (i.e. isothiocyanate or bromoacetamide).

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Novel N-terminus-to-side-chain cyclic analogs of the opioid peptide dynorphin (Dyn) A-(1-11)NH(2) were prepared that retain the basicity of the N-terminal amine and restrict the backbone conformation around the important Tyr(1) residue. Cyclic peptides were synthesized in which the N-terminal amine and the N(epsilon)-amine of a Lys at position 3 or 5 were attached to the alpha-carbon and carbonyl of an acetyl group, respectively. Several synthetic strategies were explored with detailed analysis of the side reactions in order to obtain the desired cyclic peptides.

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cyclo[d-Asp(2),Dap(5)]Dyn A-(1-13)NH(2) (Dap, 2,3-diaminopropionic acid; Dyn A, dynorphin A), synthesized previously in our laboratory, showed sub-nanomolar affinity for kappa opioid receptors and potent agonist activity in the guinea pig ileum assay (Arttamangkul et al., J. Med.

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As part of an effort to develop peptide-based affinity labels for opioid receptors, [Leu(5)]enkephalin (LeuEnk) and DTLET (Tyr-D-Thr-Gly-Phe-Leu-Thr), potent agonists for delta receptors, were selected as the parent peptides for further modification. The affinity label derivatives were prepared using standard Fmoc solid-phase peptide synthesis in conjunction with Fmoc-Phe(p-NHAlloc) (Fmoc: 9-flourenylmethoxycarbonyl;) and selective modification of the p-amino group on this residue. The electrophilic isothiocyanate and bromoacetamide groups were introduced into the para position of Phe(4); the corresponding free amine-containing peptides were also prepared for comparison.

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In plant bugs (Miridae), females produce sex pheromones in the metathoracic scent gland, which in most other true bugs (Heteroptera) is responsible for chemical defense. The possibility that the metathoracic gland secretion of male plant bugs plays a role other than defense has been largely overlooked. Here we show that in a pine-inhabiting mirid, Phytocoris difficilis Knight, hexyl butyrate and ( E)-2-hexenyl butyrate are abundantly produced only in males; we demonstrate that these metathoracic gland compounds elicit strong antennal responses in conspecific males, and that these butyrates totally interrupt attraction of males to the female-produced sex pheromone.

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The synthetic aggregation pheromone of the large milkweed bug, Oncopeltus fasciatus (Dallas) (Lygaeinae), also attracted males of the plant bug, Phytocoris difficilis Knight (Miridae). Field testing partial blends against the six-component blend comprising the Oncopeltus pheromone showed that cross-attraction of P. difficilis males was due to synergism between (E)-2-octenyl acetate and (E,E)-2,4-hexadienyl acetate.

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Phenylalanine at position 4 of the peptide dynorphin A (Dyn A) is an important residue for opioid receptor affinity and activity, but there is very little information available on the structure-activity relationships or conformational preference of this residue for interaction with kappa-opioid receptors. Based on the hypothesis that the spatial orientation of the aromatic ring at position 4 of Dyn A is important for opioid receptor affinity and selectivity, a series of Dyn A analogues with various Phe derivatives substituted at position 4 were synthesized and evaluated for their opioid receptor affinity and activity. The L- and D-Homophe4 (homophenylalanine) analogues of [D-Ala8]Dyn A-(1-11)NH2 were compared to the (R)- and (S)-Atc4 (2-aminotetralin-2-carboxylic acid) derivatives (Aldrich et al.

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Article Synopsis
  • Neotropical monkeys, specifically wedge-capped capuchin monkeys, engage in self-anointing by using millipedes, potentially to deter mosquitoes.
  • Recent experiments show that compounds secreted by these millipedes decrease the landing and feeding rates of yellow fever mosquitoes, indicating a repellent effect.
  • These millipede compounds also trigger self-anointing behavior in other capuchin species, suggesting a broader significance in their interaction with environmental threats.
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This multi-author paper reviews current work by USDA-ARS scientists in the field of chemical ecology. Work with pheromones, the discovery and development of the codling moth kairomone, studies on insect-plant interactions and chemically mediated tritrophic plant-insect interactions have led to practical methods for control of important insect pests.

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