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HOXA3 accelerates wound healing in diabetic and aged non-diabetic mammals. Sci Rep 2023; 13:9923. [PMID: 37337031 DOI: 10.1038/s41598-023-36933-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 06/13/2023] [Indexed: 06/21/2023] Open
Abstract
Chronic wounds are characterized by a persistent, hyper-inflammatory environment that prevents progression to regenerative wound closure. Such chronic wounds are especially common in diabetic patients, often requiring distal limb amputation, but occur in non-diabetic, elderly patients as well. Induced expression of HoxA3, a member of the Homeobox family of body patterning and master regulatory transcription factors, has been shown to accelerate wound closure in diabetic mice when applied topically as a plasmid encased in a hydrogel. We now provide independent replication of those foundational in vivo diabetic wound closure studies, observing 16% faster healing (3.3 mm wounds vs 3.9 mm wounds at Day 9 post original injury of 6 mm diameter) under treatment with observable microscopic benefits. We then expand upon these findings with minimal dose threshold estimation of 1 μg HoxA3 plasmid delivered topically at a weekly interval. Furthermore, we observed similarities in natural wound healing rates between aged non-diabetic mice and young diabetic mice, which provided motivation to test topical HoxA3 plasmid in aged non-diabetic mice. We observed that HoxA3 treatment achieved complete wound closure (0 mm diameter) at 2 weeks whereas untreated wounds were only 50% closed (3 mm wound diameter). We did not observe any gross adverse effects macroscopically or via histology in these short studies. Whether as a plasmid or future alternative modality, topical HoxA3 is an attractive translational candidate for chronic wounds.
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Use of topical clascoterone for the treatment of hidradenitis suppurativa. JAAD Case Rep 2023; 36:38-39. [PMID: 37215295 PMCID: PMC10196707 DOI: 10.1016/j.jdcr.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023] Open
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Self-reported beta-lactam allergy in government and private hospitals in Cape Town, South Africa. S Afr Med J 2023; 113:69-74. [PMID: 36757070 DOI: 10.7196/samj.2023.v113i2.16760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Indexed: 02/10/2023] Open
Abstract
BACKGROUND Up to a quarter of inpatients in high-income countries (HICs) self-report beta-lactam allergy (BLA), which if incorrect,increases the use of alternative antibiotics, worsening individual health outcomes and driving bacterial resistance. In HICs, up to 95% ofself-reported BLAs are incorrect. The epidemiology of BLA in low- and middle-income African countries is unknown. OBJECTIVES To describe the epidemiology and de-labelling outcomes of self-reported BLA in hospitalised South African (SA) patients. METHODS Point-prevalence surveys were conducted at seven hospitals (adult, paediatric, government and privately funded, district andtertiary level) in Cape Town, SA, between April 2019 and June 2021. Ward prescription records and in-person interviews were conductedto identify and risk-stratify BLA patients using the validated PEN-FAST tool. De-labelling was attempted at the tertiary allergy clinic atGroote Schuur Hospital. RESULTS A total of 1 486 hospital inpatients were surveyed (1 166 adults and 320 children). Only 48 patients (3.2%) self-reported a BLA,with a higher rate in private than in government-funded hospitals (6.3% v. 2.8%; p=0.014). Using the PEN-FAST tool, only 10.4% (n=5/48)of self-reported BLA patients were classified as high risk for true penicillin hypersensitivity. Antibiotics were prescribed to 70.8% (n=34/48)of self-reported BLA patients, with 64.7% (n=22/34) receiving a beta-lactam. Despite three attempts to contact patients for de-labelling atthe allergy clinic, only 3/36 underwent in vivo testing, with no positive results, and 1 patient proceeded to a negative oral challenge. CONCLUSION Unlike HICs, self-reported BLA is low among inpatients in SA. The majority of those who self-reported BLA were low risk fortype 1 hypersensitivity, but outpatient de-labelling efforts were largely unsuccessful.
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Highly Sensitive, Stretchable, and Robust Strain Sensor Based on Crack Propagation and Opening. ACS APPLIED MATERIALS & INTERFACES 2023; 15:1798-1807. [PMID: 36548931 PMCID: PMC10403976 DOI: 10.1021/acsami.2c16741] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Soft and stretchable strain sensors have been attracting significant attention. However, the trade-off between the sensitivity (gauge factor) and the sensing range has been a major challenge. In this work, we report a soft stretchable resistive strain sensor with an unusual combination of high sensitivity, large sensing range, and high robustness. The sensor is made of a silver nanowire network embedded below the surface of an elastomeric matrix (e.g., poly(dimethylsiloxane)). Periodic mechanical cuts are applied to the top surface of the sensor, changing the current flow from uniformly across the sensor to along the conducting path defined by the open cracks. Both experiment and finite element analysis are conducted to study the effect of the slit depth, slit length, and pitch between the slits. The stretchable strain sensor can be integrated into wearable systems for monitoring physiological functions and body motions associated with different levels of strain, such as blood pressure and lower back health. Finally, a soft three-dimensional (3D) touch sensor that tracks both normal and shear stresses is developed for human-machine interfaces and tactile sensing for robotics.
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Psoriasis adverse events and associated medications as reported in the US Food and Drug Administration’s Adverse Event Reporting System from 2016 to 2021. JAAD Int 2022; 7:144-145. [PMID: 35497638 PMCID: PMC9043660 DOI: 10.1016/j.jdin.2022.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Significant improvement of dermatitis herpetiformis with tofacitinib. Dermatol Online J 2021; 27. [PMID: 34391330 DOI: 10.5070/d327754365] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 08/09/2021] [Indexed: 11/08/2022] Open
Abstract
Dermatitis herpetiformis (DH) is a rare autoimmune blistering disorder in which patients with celiac disease, a gluten-sensitive enteropathy, present with a severely pruritic papulovesicular eruption over extensor surfaces such as the knees, elbows, lower back, buttocks, and neck. Patients are instructed to adhere to a gluten-free diet for purposes of improving their skin disease and gluten-sensitive enteropathy; this is the only treatment that lowers risk of enteropathy-associated T cell lymphoma. Patients who adhere to a strict gluten-free diet often have remission of their skin disease over months to years. Dapsone is a rapid and extremely effective first-line treatment option and often used while transitioning to a gluten-free diet. Aside from gluten-free diet and dapsone, second-line treatment options include sulfapyridine, sulfasalazine, and colchicine. Some patients have difficulty adhering to a gluten-free diet or develop intolerable side effects to systemic therapies. Furthermore, there is limited data on the use of the second-line treatments. Recent studies have shed light on the role of JAK-STAT-dependent pathways in the pathogenesis of dermatitis herpetiformis. We present a patient treated with tofacitinib, 5mg twice daily, an oral JAK1/3 inhibitor, who demonstrated clinical improvement of DH and control of new lesion development.
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Erythema nodosum-like panniculitis associated with immune checkpoint inhibitor therapy: Two cases reporting a rare cutaneous adverse event. JAAD Case Rep 2021; 13:118-120. [PMID: 34189226 PMCID: PMC8220292 DOI: 10.1016/j.jdcr.2021.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Uranium integral fission product yields for a spectrally-shaped 14.1 MeV neutron source at the National Ignition Facility. Appl Radiat Isot 2021; 173:109711. [PMID: 33848751 DOI: 10.1016/j.apradiso.2021.109711] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 11/27/2022]
Abstract
This paper describes the experimental results for an energy tuning assembly created to modify the National Ignition Facility deuterium-tritium fusion neutron source into a notional thermonuclear and prompt fission neutron spectrum, which has applications in integral measurements, nuclear data benchmarks, and radiation effects on microelectronics. The Monte Carlo neutron transport utilized MCNP5 to estimate the ETA-modified fluence using the ENDF-B/VIII.0 and IRDFF-II continuous energy nuclear data libraries, and SCALE Sampler was used to estimate the systematic nuclear data covariance using ENDF-B/VII.1 and IRDFF-II in a 252-group structure. The experiment fielded eight activation foils and a highly enriched uranium sample. This provided fifteen reaction channels that were used in a forward-fit comparison to the modeled results and to unfold the neutron spectrum using STAYSL. Gamma-ray spectrometry was performed on the activation and highly enriched uranium foils, and the reduced χ2 between the modeled and experimental values was 1.21. The results from the STAYSL unfold, reduced χ2=1.62, indicated that the modeled neutron spectrum was achieved and the systematic nuclear data uncertainty associated with the neutron transport and activation product cross sections was representative of the experiment. Integral cumulative fission product yield data were collected for 37 mass chains with a combination of gamma-ray spectrometry and radiochemical analysis. Fission product analysis was generally in agreement with two models using a semi-empirical fit and the General Observables of Fission code, with the exception of mass chains 88, 109, 111, 112, 113, 129, 139, 142, 144, 151, and 156.
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Abstract
Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry.
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P1-252 Creutzfeldt-Jakob Disease (CJD) surveillance in Texas2010: a surveillance Odyssey. Br J Soc Med 2011. [DOI: 10.1136/jech.2011.142976e.44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Prevalence and use of clinical pathways in 23 countries - an international survey by the European Pathway Association. ACTA ACUST UNITED AC 2006. [DOI: 10.1258/j.jicp.2006.124] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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113: Heavy Metals Exposures and Neural Tube Defects in Offspring. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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The use of consent-to-treatment forms at the state hospital: an audit in 1996 and 2000. MEDICINE, SCIENCE, AND THE LAW 2003; 43:132-135. [PMID: 12741657 DOI: 10.1258/rsmmsl.43.2.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Crystal structure of isopropyl 3-isopropyloxy-5-oxophenyl-δ2-1,2,4-triazoline-1-carboxylate, C15H19N3O4. Z KRIST-NEW CRYST ST 2002. [DOI: 10.1524/ncrs.2002.217.1.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Point of technique: The retrograde Add-a-Cath technique: an aid to changing the difficult suprapubic catheter. BJU Int 1999; 84:365. [PMID: 10468739 DOI: 10.1046/j.1464-410x.1999.00225.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Vasopressin in the forebrain of common marmosets (Callithrix jacchus): studies with in situ hybridization, immunocytochemistry and receptor autoradiography. Brain Res 1997; 768:147-56. [PMID: 9369311 DOI: 10.1016/s0006-8993(97)00636-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The distribution of vasopressin (AVP) producing cells, their projections and AVP receptors was examined in the brain of common marmosets (Callithrix jacchus) using in situ hybridization, immunocytochemistry and receptor autoradiography. Clusters of cells labeled for AVP mRNA or stained for AVP immunoreactivity (AVP-ir) were found in the paraventricular (PVN), supraoptic (SON) and suprachiasmatic nuclei (SCN) of the hypothalamus. Scattered AVP producing cells were also found in the lateral hypothalamus and the bed nucleus of the stria terminalis (BST). Neither AVP mRNA-labeled nor AVP-ir cells were detected in the amygdala. Although AVP-ir fibers were evident outside of the hypothalamic-neurohypophyseal tract, a plexus of fibers in the lateral septum, as observed in the rat brain, was not detected. Receptor autoradiography using 125I-linear-AVP revealed specific binding for AVP receptors in the nucleus accumbens, diagonal band, lateral septum, the BST, SCN, PVN, amygdala, anterodorsal and ventromedial nucleus of the hypothalamus, indicating sites for central AVP action in the marmoset brain. Together, these data provide a comprehensive picture of AVP pathways in the marmoset brain, demonstrating differences from rodents in the distribution of cell bodies, fibers and receptors.
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Abstract
Vasopressin (AVP) and oxytocin (OT) immunoreactive (ir) neurons and fibers were examined in the forebrain of male and female common marmosets (Callithrix jacchus). As expected from previous studies of cell distribution in the rodent and primate brain, AVP-ir cells were most evident in the paraventricularis, supraopticus, and suprachiasmaticus of the hypothalamus. AVP-ir cells were also widely distributed in the lateral hypothalamus and the bed nucleus of the stria terminalis. A sexually dimorphic pattern of AVP-ir cells was found in the bed nucleus of the stria terminalis, in which males had more AVP-ir cells than females. OT-ir cells were found in the paraventricularis and supraopticus of the hypothalamus as well as in the bed nucleus of the stria terminalis and the medial amygdala. Male and female marmosets did not differ in the distribution of OT-ir cells. Fibers for both AVP and OT were evident outside of the hypothalamic-neurohypophyseal tract, but a plexus of AVP-ir fibers in the lateral septum or lateral habenular nucleus, as seen in the rat brain, could not be detected for either peptide.
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Abstract
We undertook this study to determine the types and frequency of injuries sustained in the sport of luge. Before this study, no data were available in the medical literature on luge injuries. We performed a retrospective analysis between the years 1985 and 1992 using data obtained from the athlete injury and illness report forms at the US Training Center Sports Medicine Clinic in Lake Placid, New York. During the 7 years examined, 1043 athletes took 57,244 track runs and sustained 407 injuries. The risk of sustaining an injury was 0.39 per person per year, and the risk of an injury causing the loss of more than 1 day of practice was 0.04 per person per year. Contusions were the major injury (51%), followed by strains (27%). Strains of the neck muscles and contusions of extremities, especially the hands, were characteristic injuries sustained by athletes. The most serious injuries were concussions (2%) and fractures (3%). Crashes were responsible for 64% of injuries. Luge appears to be a relatively safe sport with injury rates comparable with recreational alpine skiing.
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Effect of water overflowing from a herbicide‐treated rice field on herbicide performance. ACTA ACUST UNITED AC 1992. [DOI: 10.1080/09670879209371641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Cellular and extracellular phospholipase A2 activity in zymosan pleurisy in rat. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1990; 275:145-54. [PMID: 2239443 DOI: 10.1007/978-1-4684-5805-3_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The pleural exudate from rats treated intrapleurally with zymosan contains phospholipase A2 (PLA2) activity which is Ca2(+)-independent and optimally active at a neutral pH. This PLA2 activity was found in approximately equal amounts in both the cellular and extracellular fractions of the exudate. The Ca2(+)-independency of the PLA2's in the pleural exudate distinguishes them from plasma PLA2's and this suggests that the source of the exudate PLA2's is not plasma. The appearance of PLA2 activity in zymosan-induced pleural exudate correlates temporally with increases in exudate volume and pleural cell number. In all cases, the maximum response was seen 24 hr after zymosan challenge. All parameters of pleurisy and PLA2 activity are similarly sensitive to the steroid dexamethasone which has been hypothesized to act, in part, through the synthesis of PLA2 inhibitory peptides. In its entirety, this information suggests that there is a relationship between pleural PLA2 activity and the appearance of pleural inflammation (exudate volume and cells) and that PLA2 may play an important role in the initiation and propagation of this inflammatory process in rats. Furthermore, the zymosan-induced pleurisy model may serve as a useful model for the identification of PLA2 inhibitors with antiinflammatory activity.
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The volunteer physician program of the Lake Placid Olympic Training Center. DELAWARE MEDICAL JOURNAL 1984; 56:681-3. [PMID: 6500108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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POST-MI HOSPITAL COURSE AND RESPONSE TO EARLY EXERCISE TRAINING. Med Sci Sports Exerc 1982. [DOI: 10.1249/00005768-198202000-00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dance Therapy Program for Nursing Homes. THE GERONTOLOGIST 1972. [DOI: 10.1093/geront/12.3_part_1.312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Aerothionin and homoaerothionin: two tetrabromo spirocyclohexadienylisoxazoles from Verongia sponges. ACTA ACUST UNITED AC 1972. [DOI: 10.1039/p19720000018] [Citation(s) in RCA: 85] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Heterocyclic compounds from alloxan and amines. XIII. Phenazine freeradical betaines and their dehydro dimers derived from alloxan and 2-aminodiphenylamines. Aust J Chem 1971. [DOI: 10.1071/ch9712593] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
2-Amino-N-alkydiphenylamines
and 2-aminotriphenylamines react with alloxan at room temperature to give
green, intensely coloured, stable, free-radical betaines (dihydrophenazinioylbarbiturates).
Heating the free-radical betaines alone or in a solvent gives rise to blue
dimers. 3,7-Disubstitution of the phenazinioyl nucleus by methyl groups
prevents formation of the blue dimers, which are therefore considered to arise
by dimerization at the 3-position, followed by dehydrogenation. Dimerization of
3,7- dimethyldihydrophenazinioylbarbi- turates gives deep green 3,3?-dimers in which the 3,3?-methyl
substituents prevent the dehydrogenation step entailed in the formation of the
blue dehydro dimers. ��� A violent explosion occurred in two
instances during preparation of phenazine by oxidative sublimation of crude
dihydrophenazine by Morley's method (J. chem. Soc., 1952, 4008).
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Abstract
Secondary and tertiary alicyclic amines (piperidine,
morpholine, N-ethyl-piperidine, and N-methylmorpholine), and aromatic nitrogen heterocycles (benzimidazole, 2-methyl- and
2-t-butyl-benzimidazole, and pyridine), are shown to yield the heterocyclic
amine purpurates (murexide
analogues) by reaction with anhydrous alloxan in dry
acetic acid. The central nitrogen atom of the purpurate
anion, normally derived from ammonia, is considered to arise from degradation
of some of the alloxan, and is accompanied by liberation
of carbon dioxide. Pyrrolidine did not yield a purpurate (or carbon dioxide) under the reaction
conditions.
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Heterocyclic compounds from alloxan and amines. XI. Uramils, dialuric acids, and related compounds. Aust J Chem 1970. [DOI: 10.1071/ch9701229] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Preparation of a number of uramils and 5-aryldialuric acids
from
o-substituted anilines is described.
Methylation of the uramils gave dimethoxy-N-monomethyl
pyrimidine derivatives accompanied by minor amounts of trimethoxy-pyrimidines,
and the dialuric acids gave 1,3-dimethylpyrimidines
or 5-methoxy-1,3-dimethylbarbituric acids (with an
excess of diazomethane). Ring contraction of the 1,3-dimethyldialuric
acids gave the isomeric 5-N-methylcarbamoyloxazolidine-2,4-diones. The dialuric acid from dimedone gave
a trimethyl derivative (a methoxycyclohexenyl-1,3-dimethyldialuric
acid). Anthranilic acid and alloxan
in acetic acid gave a benzoxazonespirobarbituric
acid, but in aqueous ethanol yielded a dialuric acid
which was characterized by conversion into several derivatives. Infrared and N.M.R. data
are recorded for the uramils, dialuric
acids, and their derivatives.
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Aerothionin, a tetrabromo-compound from Aplysina aerophoba and Verongia thiona. ACTA ACUST UNITED AC 1970. [DOI: 10.1039/c29700000752] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Heterocyclic compounds from alloxan and amines. XII. Tetrahydroquinoxalinespirobarbituric acids and 5-(1-Benzimidazolio)-4-barbiturates from 2-Dialkylaminoanilines. Aust J Chem 1970. [DOI: 10.1071/ch9701249] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The betaine formed from 2-dimethylaminoaniline and alloxan
is shown to be 5-(3-methyl-1-benzimidazolio)-4-barbiturate
by synthesis from 1-methylbenzimidazole; it's
N,S-dimethyl derivative (1,3-dimethylbarbiturate) was
also synthesized. A number of analogous betaines was
prepared from alloxan and 1-o-aminophenyl
derivatives of secondary amines, and it was shown by tracer studies that
enamines are not intermediates in
the reaction. A probable mechanism is discussed. 2-Amino-N-mesityl-N-methylaniline and the N-ethyl analogue gave tetrahydroquinoxaline-spirohexahydrotrioxopyrimidines with alloxan instead of betaines, and
alkaline hydrolysis led to the related 4-mesityltetrahydroquinoxalinohydantoins.
Some of the betaines, and one of the spirans, were also obtained by oxidation of uramils. Mass spectra of the betaines are discussed, and N.M.R. data are reported. Ring
expansion occurs during conversion of 5-(3-methyl-1-benzimidazolio)-4-barbiturate
into the related tetrahydroquinoxalinespirobarbituric
acid by reduction with sodium borohydride.
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