Pediatric tympanostomy tube assessment via deep learning.

PURPOSE: Tympanostomy tube (TT) placement is the most frequently performed ambulatory surgery in children under 15. After the procedure it is recommended that patients follow up regularly for "tube checks" until TT extrusion. Such visits incur direct and indirect costs to families in the form of days off from work, copays, and travel expenses. This pilot study aims to compare the efficacy of tympanic membrane (TM) evaluation by an artificial intelligence algorithm with that of clinical staff for determining presence or absence of a tympanostomy tube within the TM. METHODS: Using a digital otoscope, we performed a prospective study in children (ages 10 months-10 years) with a history of TTs who were being seen for follow up in a pediatric otolaryngology clinic. A smartphone otoscope was used by study personnel who were not physicians to take ear exam images, then through conventional otoscopic exam, ears were assessed by a clinician for tubes being in place or tubes having extruded from the TM. We trained and tested a deep learning (artificial intelligence) algorithm to assess the images and compared that with the clinician's assessment. RESULTS: A total of 123 images were obtained from 28 subjects. The algorithm classified images as TM with or without tube in place. Overall classification accuracy was 97.7 %. Recall and precision were 100 % and 96 %, respectively, for TM without a tube present, and 95 % and 100 %, respectively, for TM with a tube in place. DISCUSSION: This is a promising deep learning algorithm for classifying ear tube presence in the TM utilizing images obtained in awake children using an over-the-counter otoscope available to the lay population. We are continuing enrollment, with the goal of building an algorithm to assess tube patency and extrusion.

Herschel/HIFI observations of the circumstellar ammonia lines in IRC+10216.

CONTEXT: A discrepancy exists between the abundance of ammonia (NH3) derived previously for the circumstellar envelope (CSE) of IRC+10216 from far-IR submillimeter rotational lines and that inferred from radio inversion or mid-infrared (MIR) absorption transitions. AIMS: To address the discrepancy described above, new high-resolution far-infrared (FIR) observations of both ortho- and para-NH3 transitions toward IRC+10216 were obtained with Herschel, with the goal of determining the ammonia abundance and constraining the distribution of NH3 in the envelope of IRC+10216. METHODS: We used the Heterodyne Instrument for the Far Infrared (HIFI) on board Herschel to observe all rotational transitions up to the J = 3 level (three ortho- and six para-NH3 lines). We conducted non-LTE multilevel radiative transfer modelling, including the effects of near-infrared (NIR) radiative pumping through vibrational transitions. The computed emission line profiles are compared with the new HIFI data, the radio inversion transitions, and the MIR absorption lines in the ν2 band taken from the literature. RESULTS: We found that NIR pumping is of key importance for understanding the excitation of rotational levels of NH3. The derived NH3 abundances relative to molecular hydrogen were (2.8 ± 0.5) × 10-8 for ortho-NH3 and [Formula: see text] for para-NH3, consistent with an ortho/para ratio of 1. These values are in a rough agreement with abundances derived from the inversion transitions, as well as with the total abundance of NH3 inferred from the MIR absorption lines. To explain the observed rotational transitions, ammonia must be formed near to the central star at a radius close to the end of the wind acceleration region, but no larger than about 20 stellar radii (1σ confidence level).

The role of shugoshin in meiotic chromosome segregation.

During meiosis, DNA replication is followed by 2 successive chromosome segregation events, resulting in the production of gametes with a haploid number of chromosomes from a diploid precursor cell. Faithful chromosome segregation in meiosis requires that sister chromatid cohesion is lost from chromosome arms during meiosis I, but retained at centromeric regions until meiosis II. Recent studies have begun to uncover the mechanisms underlying this stepwise loss of cohesion in meiosis and the role of a conserved protein, shugoshin, in regulating this process.

Thin-layer chromatography with biological detection in phytochemistry.

Bioautography on thin-layer chromatographic (TLC) plates is a means of detecting the biological activity of a sample which has migrated on the plate with a suitable solvent. It only requires small amounts of sample and is ideal for the investigation of plant constituents, which often occur as complex mixtures. It can be used for the target-directed isolation of these constituents. In contrast to HPLC, many samples can be run at the same time on TLC. Organic solvents, which cause inactivation of enzymes or death of living organisms, can be completely removed before biological detection. Many bioassays are compatible with TLC. Antimicrobial, radical scavenging, antioxidant activities and enzyme inhibition feature among the tests that are employed.

Xanthones from Gentianella amarella ssp. acuta with acetylcholinesterase and monoamine oxidase inhibitory activities.

Two new xanthone glycosides, corymbiferin 3-O-beta-D-glucopyranoside (1) and swertiabisxanthone-I 8'-O-beta- d-glucopyranoside (2), were isolated from Gentianella amarella ssp. acuta, along with eight known xanthones: triptexanthoside C, veratriloside, corymbiferin 1-O-glucoside, swertianolin, norswertianolin, swertiabisxanthone-I, bellidin, and bellidifolin, four of them identified for the first time in G. amarella ssp. acuta. The isolation was conducted mainly by centrifugal partition chromatography, and the structures of the isolated compounds were established on the basis of spectrometric data including 2D NMR and mass spectrometry. Xanthones were weakly active against acetylcholinesterase (AChE), except triptexanthoside C, which inhibited AChE with an IC(50) of 13.8 +/- 1.6 microM. Some compounds were active against monoamine oxidases (MAO): bellidin and bellidifolin showed interesting inhibitory activity of MAO A, while swertianolin, the 8-O-glucopyranoside form of bellidifolin, gave 93.6% inhibition of MAO B activity at 10(-5) M.

The determination of huperzine A in European Lycopodiaceae species by HPLC-UV-MS.

A rapid qualitative HPLC-UV-MS method was developed for the detection of huperzine A in Lycopodiaceae species. HPLC coupled with mass spectrometry experiments allowed the identification of the alkaloid and enabled targeted analysis of complex matrices such as herbal extracts. Huperzine A was detected by single ion monitoring of the pseudomolecular ion [M + H]+ at m/z 243.2. The alkaloid was also detected on TLC in a bioautographic enzyme assay with acetylcholinesterase to show the activity of the compound. Four Lycopodiaceae species collected in Switzerland were tested by these methods and Huperzia selago (L.) Bernh. ex Schrank et Martius was the only species found to contain huperzine A.

3-Farnesyl-2-hydroxybenzoic acid is a new anti-Helicobacter pylori compound from Piper multiplinervium.

A new prenylated salicylic acid derivative, 3-farnesyl-2-hydroxy benzoic acid (1), was isolated from the leaves of Piper multiplinervium C. DC. (Piperaceae). It showed anti-Helicobacter pylori activity (MIC 37.5 microg/ml) and antimicrobial activity at MICs between 2.5 and 5 microg/ml against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Mycobacterium smegmatis, Pseudomonas aeruginosa and Candida albicans. Its structure was elucidated by means of MS, 1H and 13C NMR. The ethnomedical claim of Piper multiplinervium to treat stomach aches by the Kuna Indians of Panama may be justified by anti-Helicobacter pylori activity of its MeOH extract.

Developments in the application of counter-current chromatography to plant analysis.

Counter-current chromatography is a very versatile separation technique which does not require a solid stationary phase. It relies simply on the partition of a sample between the two phases of an immiscible solvent system. Some of the more recent applications of the method to the separation of plant-derived natural products are described here. Crude plant extracts and semi-pure fractions can be chromatographed, with sample loads ranging from milligrams to grams. Aqueous and non-aqueous solvent systems are used and the separation of compounds with a wide range of polarities is possible. The technique is complementary to other chromatographic methods and is compatible with gradient systems. The possibilities for solvent selection are almost limitless but some guidelines for the choice of successful systems are presented.

On-line identification of unstable iridoids from Jamesbrittenia fodina by HPLC-MS and HPLC-NMR.

HPLC-UV-MS analysis of the methanol extract of Jamesbrittenia fodina (Wild) O. M. Hilliard (Scrophulariaceae) revealed the presence of different iridoid cinnamic esters; however, isolation of these constituents was prevented by instability problems. HPLC-UV-MS and HPLC-NMR analysis of the mixtures obtained after a tentative isolation indicated that, in the first instance, instability was due to a light-induced cis/trans isomerisation of the cinnamic moieties. Further investigation of related compounds showed an additional instability problem linked to other chemical transformations. A detailed HPLC-NMR-MS study of these fractions demonstrated that the modifications occurred on the rhamnose moiety of these iridoids. It could be concluded that the second type of instability was attributable to transesterification of the cinnamic moiety on the rhamnose unit. The recording of stop-flow HPLC-NMR spectra for specific HPLC peaks permitted the direct monitoring of these transformations. Based on these on-line data, six new unstable aucubin derivatives were efficiently characterised.

On-line identification of tropane alkaloids from Erythroxylum vacciniifolium by liquid chromatography-UV detection-multiple mass spectrometry and liquid chromatography-nuclear magnetic resonance spectrometry.

The bark of catuaba (Erythroxylum vacciniifolium Martius, Erythroxylaceae), a tree native to the northern part of Brazil, was investigated for its alkaloid content. With the aim of obtaining preliminary structure information on-line, the alkaloid extract was analysed by high-performance liquid chromatography coupled to diode array UV detection, to mass spectrometry and to nuclear magnetic resonance. Interpretation of on-line spectroscopic data obtained from this extract led to structural elucidation of six new alkaloids and partial identification of 18 potentially original alkaloids bearing the same tropane skeleton esterified in positions 3 and 6 by 1-methyl-1H-pyrrol-2-carboxylic acid and/or 4-hydroxy-3,5-dimethoxybenzoic acid.

Antifungal isopimaranes from Hypoestes serpens.

Five isopimarane diterpenes (7beta-hydroxyisopimara-8,15-dien-14-one, 14alpha-hydroxyisopimara-7,15-dien-1-one, 1beta,14alpha-dihydroxyisopimara-7,15-diene, 7beta-hydroxyisopimara-8(14),15-dien-1-one and 7beta-acetoxyisopimara-8(14),15-dien-1-one) have been isolated from the leaves of Hypoestes serpens (Acanthaceae). All compounds exhibited antifungal activity against both the plant pathogenic fungus Cladosporium cucumerinum and the yeast Candida albicans; two of them also displayed an acetylcholinesterase inhibition. The structures of the compounds were determined by means of spectrometric methods, including 1D and 2D NMR experiments and MS analysis.

Triterpenoid saponins from the roots of Silene cucubalus.

A new triterpenoid saponin was isolated from the roots of Silene cucubalus and its structure was determined on the basis of one- and two-dimensional NMR spectroscopy as gypsogenin 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside. A known saponin, quillaic acid 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside, was also isolated.

On-line identification of unstable catalpol derivatives from Jamesbrittenia fodina by LC-mS and LC-NMR.

LC-UV-MS analysis of the methanol extract of Jamesbrittenia fodina O. M. Hilliard (Scrophulariaceae) revealed the presence of cinnamic ester derivatives. Two isomeric pairs of these constituents were detected, but could not be isolated. In order to identify these unstable compounds, LC-1H-NMR spectra were obtained for each individual isomer and standard NMR measurements were performed in-mixture. The spectra clearly demonstrated that the fractions consisted of mixtures of cis and trans cinnamoyl catalpol glycoside esters.

A rapid TLC bioautographic method for the detection of acetylcholinesterase and butyrylcholinesterase inhibitors in plants.

A simple and rapid bioautographic enzyme assay on TLC plates has been developed for the screening of acetylcholinesterase and butyrylcholinesterase inhibition by plant extracts. Enzyme activity was detected by the conversion of naphthyl acetate into naphthol and the formation of the corresponding purple-coloured diazonium dye with Fast Blue B salt. Inhibitors of cholinesterases produced white spots on the dye-coloured background of the TLC plates. The alkaloids galanthamine and physostigmine, which are known inhibitors of acetylcholinesterase, were used to determine the sensitivity of the assay. Various plant extracts were tested using the bioassay.

NMR and LC-MSn characterisation of two minor saponins from Ilex paraguariensis.

Two minor saponins obtained from the methanolic extract of the leaves of Ilex paraguariensis have been characterised by 13C-NMR, 1H-NMR, API-MS and chemical hydrolysis as oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)-(28-->1)- beta-D-glucopyranosyl ester (guaiacin B) and oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-(alpha-L-rhamnopyranosyl- (1-->2))-alpha-L-arabinopyranosyl)-(28-->1)-beta-D-glucopyranosyl ester (nudicaucin C). Both are isomeric forms of the known matesaponins 1 (MSP 1) and 2 (MSP 2) and differ only by the nature of the aglycone: they have oleanolic acid instead of ursolic acid, as found in the matesaponins. These minor saponins have not been fully separated from their major isomers MSP 1 and 2 and were characterised by in-mixture NMR analysis, LC-MS and LC-MSn experiments.

Screening of Malian medicinal plants for antifungal, larvicidal, molluscicidal, antioxidant and radical scavenging activities.

A total of 78 different extracts from 20 medicinal plants belonging to 14 plant families from Mali were tested for their antifungal, larvicidal, molluscicidal, antioxidant and radical scavenging activities. Dichloromethane, methanol, water and ethanol extracts were used. TLC autobiography for antifungal activity was run with Cladosporium cucumerinum and Candida albicans. Extracts were also tested on the larvae of the mosquitoes Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. Molluscicidal activities were established with the snails Biomphalaria glabrata, Biomphalaria pfeifferi and Bulinus truncatus. beta-Carotene and DPPH solutions sprayed on TLC plates were used for antioxidant and radical scavenging assays. Of the extracts investigated, 20% were antioxidant and radical scavengers, 19% fungicidal, 30% were larvicidal and 11% were molluscicidal. Three of the plant extracts, from Cussonia barteri (Araliaceae), Glinus oppositifolius (Aïzoaceae) and Lannea velutina (Anacardiaceae) gave positive responses in all four tests.

Five new prenylated stilbenes from the root bark of Lonchocarpus chiricanus.

Besides the known compounds longistylines C (1), D (2), and 3,5-dimethoxystilbene (5), five new prenylated stilbenes, named chiricanines A--E (3, 4, 6--8), have been isolated from the root bark of Lonchocarpus chiricanus. Their structures were resolved on the basis of spectrometric methods including (1)H, (13)C, and 2D NMR experiments and mass spectrometry. Compound 3 was the only prenylated stilbene to demonstrate antifungal effects against Cladosporium cucumerinum. Four of the isolated compounds showed toxic properties against larvae of the yellow fever-transmitting mosquito Aedes aegypti. Compound 5 was found to be as potent as rotenone in larvicidal dilution tests.

A localized GTPase exchange factor, Bud5, determines the orientation of division axes in yeast.

GTPases are widespread in directing cytoskeletal rearrangements and affecting cellular organization. How they do so is not well understood. Yeast cells divide by budding, which occurs in two spatially programmed patterns, axial or bipolar [1-3]. Cytoskeletal polarization to form a bud is governed by the Ras-like GTPase, Bud1/Rsr1, in response to cortical landmarks. Bud1 is uniformly distributed on the plasma membrane, so presumably its regulators, Bud5 GTPase exchange factor and Bud2 GTPase activating protein, impart spatial specificity to Bud1 action [4]. We examined the localizations of Bud5 and Bud2. Both Bud1 regulators associate with cortical landmarks designating former division sites. In haploids, Bud5 forms double rings that encircle the mother-bud neck and split upon cytokinesis so that each progeny cell inherits Bud5 at the axial division remnant. Recruitment of Bud5 into these structures depends on known axial landmark components. In cells undergoing bipolar budding, Bud5 associates with multiple sites, in response to the bipolar landmarks. Like Bud5, Bud2 associates with the axial division remnant, but rather than being inherited, Bud2 transiently associates with the remnant in late G1, before condensing into a patch at the incipient bud site. The relative timing of Bud5 and Bud2 localizations suggests that both regulators contribute to the spatially specific control of Bud1 GTPase.

Study of two plants used in traditional medicine in Zimbabwe for skin problems and rheumatism: Dioscorea sylvatica and Urginea altissima.

Two plants used in Zimbabwean traditional medicine, Dioscorea sylvatica (Dioscoreaceae) and Urginea altissima (Liliaceae), produce mild inflammation and itching when rubbed on the skin. Investigations of the causes of these cutaneous reactions showed that raphides of calcium oxalate are, at least in part, responsible for the effects. Histamine could not be detected.

A methylflavan with free radical scavenging properties from Pancratium littorale.

The isolation of 7,4'-dihydroxy-8-methylflavan (1) from the dichloromethane extract of Pancratium littorale stem was guided by an assay for free radical scavenging activity towards the 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH). The structure of 1 was established by spectrometric methods including UV, EI mass spectrometry, 1H and 13C-NMR. The free radical scavenging properties of 1 were quantified in solution using spectrophotometry.