CASE-DFT Structure Elucidation of Proton-Deficient Chlorodepsidones from the Indonesian Lichen Teloschistes flavicans and Structure Revision of Flavicansone

Biodiscovery efforts in Indonesia have aimed to explore the understudied chemical diversity of its rich lichen flora, seeking to find new products endowed with significant biological properties. The chemical screening of a Teloschistes flavicans extract led to selection of this species for further investigation. LC/MS and 1H NMR-based dereplication pinpointed six chlorodepsidones from the thallus of a sample of this lichen. This led to the streamlined isolation and the subsequent structure elucidation of the three new compounds norflavicansone 1, flavicansone 2, and isocaloploicin 3, along with the known chlorodepsidones 4-6, stictic acid 7, aurantiamide acetate 8, and parietin 9. The challenging structure elucidation of these proton-deficient metabolites benefited from a state-of-the-art workflow involving a synergistic combination of Computer-Assisted Structure Elucidation (CASE) and Density Functional Theory (DFT) calculations of the top-ranked candidates. This investigation also led to the revision of flavicansone's structure, previously described from this species. The three new molecules that are being reported here are remarkable in that they represent hybrid depsidones in which one of the aromatic rings is derived from orsellinic acid and the other is derived from β-orcinol, a rare structural feature for lichen depsidones.

Synthesis of galactomannan fragments to help NMR assignment of polysaccharides extracted from lichens

The synthesis of six model trisaccharides representative of galactomannans produced by lichens was performed through stereoselective glycosylation. These standards include linear and branched galactomannans bearing either galactofuranosyl or galactopyranosyl entities. The complete assignment of 1H and 13C signals for both forms of synthetically reduced oligosaccharides was performed. The resulting NMR data were used to quickly demonstrate the structural characteristics of minor polysaccharides within different extracts of three representative lichens.

A lupeol derivative and other isolates with antiplasmodial activity from the stem root of Rauvolfia mannii Stapf. (Apocynaceae)

Rauvolfia mannii is a plant from western and eastern areas of African continent and is widely used in folk medicine for the treatment of various diseases including malaria. Herein, one previously undescribed acylated triterpene (1), together with five already published natural products (2-6) were removed from its roots. The chemical structures of these compounds were determined by spectroscopic and spectrometric means (NMR, HRESIMS, IR and UV). In addition to the isolated triterpenoids, components 5 and 6 are also newly reported from the genus Rauvolfia. Moreover, some constituents were further tested against the chloroquine-sensitive strain of P. falciparum (3D7). It has been found that 3 and 4 showed a moderate antiplasmodial activity with IC50 values of 46.25 and 39.79 µM respectively.

Δ-Keto-acid/hydroxy-lactone isomerization in some lichen depsides, depsidones and diphenyl ethers

In some compounds in lichens, the carboxylic acid is ortho-substituted by an 2-oxoalkyl chain. This particular structure induces the existence of δ-keto-acid ka or hydroxy-lactone hl isomers, clearly identified by their NMR data and chemical properties, such as dehydration, methylation and behaviour in thermal conditions. Internal hydrogen bonding between the carboxylic acid and substituent in the ortho' position is proposed as an isomerization modulator: an H-bond acceptor (OCH3) leads to ka isomers, whereas hl isomers are obtained with an H-bond donor (OH).

Eremoxylarins D-J, Antibacterial Eremophilane Sesquiterpenes Discovered from an Endolichenic Strain of Xylaria hypoxylon

An endolichenic strain of the Ascomycetaceous Xylaria hypoxylon, cultivated alone or in coculture with another endolichenic fungus Dendrothyrium variisporum, produced seven new bioactive eremophilane sesquiterpenes eremoxylarins D-J (1-7). The isolated compounds disclosed a high similarity with the eremophilane core of the bioactive integric acid, and structures were elucidated by 1D and 2D NMR spectra and electronic circular dichroism (ECD) analyses. Eremoxylarins D, F, G, and I showed a selective activity against Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus with minimum inhibitory concentration (MIC) values between 0.39 and 12.5 μg/mL. Eremoxylarin I, the most antibacterial active sesquiterpene, was also active against HCoV-229E at a concentration nontoxic to the hepatoma Huh-7 cell line with an 50% inhibitory concentration (IC₅₀) of 18.1 μM and a 50% cytotoxic concentration (CC₅₀) of 46.6 μM.

Bacteroides fragilis derived metabolites, identified by molecular networking, decrease Salmonella virulence in mice model

In the gut microbiota, resident bacteria prevent pathogens infection by producing specific metabolites. Among bacteria belonging to phylum Bacteroidota, we have previously shown that Bacteroides fragilis or its cell-free supernatant inhibited in vitro Salmonella Heidelberg translocation. In the present study, we have analyzed this supernatant to identify bioactive molecules after extraction and subsequent fractionation using a semi-preparative reversed-phase Liquid Chromatography High-Resolution Tandem Mass Spectrometry (LC-HRMS/MS). The results indicated that only two fractions (F3 and F4) strongly inhibited S. Heidelberg translocation in a model mimicking the intestinal epithelium. The efficiency of the bioactive fractions was evaluated in BALB/c mice, and the results showed a decrease of S. Heidelberg in Peyer’s patches and spleen, associated with a decrease in inflammatory cytokines and neutrophils infiltration. The reduction of the genus Alistipes in mice receiving the fractions could be related to the anti-inflammatory effects of bioactive fractions. Furthermore, these bioactive fractions did not alter the gut microbiota diversity in mice. To further characterize the compounds present in these bioactive fractions, Liquid Chromatography High-Resolution Tandem Mass Spectrometry (LC-HRMS/MS) data were analyzed through molecular networking, highlighting cholic acid (CA) and deoxycholic acid. In vitro, CA had inhibitory activity against the translocation of S. Heidelberg by significantly decreasing the expression of Salmonella virulence genes such as sipA. The bioactive fractions also significantly downregulated the flagellar gene fliC, suggesting the involvement of other active molecules. This study showed the interest to characterize better the metabolites produced by B. fragilis to make them means of fighting pathogenic bacteria by targeting their virulence factor without modifying the gut microbiota.

Intramolecular transesterification of depsides yields fluorescent 1H-isochromen-1-ones: Application as a chemical probe for lichen determination

The reactivity of eight purified depsides obtained from six european lichens and that display as 2-oxoalkyl chain in ortho-position of the ester bond was explored. These depsides were found to lead to 1H-Isochromen-1-ones, which exhibit a distinctive blue fluorescence at 365 nm, in the presence of a 10% aqueous solution of KOH. A mechanistic explanation, involving the formation of an enolate intermediate and intramolecular transesterification, was proposed and validated by DFT. By exploiting this fluorescent phenomenon, we conceived a chemical probe (the KUV probe) that is useful for lichen determination, as exemplified on a selection of European Porpidia species.

Chemical fingerprinting of the Brazilian medicinal plant Calea pinnatifida (R. Br.) Less. (Asteraceae) collected at different altitudes

Calea pinnatifida (R. Br.) Less. is a plant of Brazilian folk medicine. We evaluated the influence of environmental factors on the chemical profile of C. pinnatifida collected during the winter season. C. pinnatifida leaves, alongside soil samples, were collected from two sites of different altitude. Plant samples were sequentially extracted, while soil samples were subject to compositional analysis. Plant extracts were compared using HPTLC-UV, using chemometric analyses to compare samplings harvested at both altitudes. Two marker metabolites, calein A (1) and acetylportentol (2), were isolated from samples collected at the respective altitudes. The differing metabolic profiles observed may be a result of the influence of environmental factors.

Inhibitory Effects of Secondary Metabolites from the Lichen Stereocaulon evolutum on Protein Tyrosine Phosphatase 1B

Protein tyrosine phosphatase 1B plays a significant role in type 2 diabetes mellitus and other diseases and is therefore considered a new drug target. Within this study, an acetone extract from the lichen Stereocaulon evolutum was identified to possess strong protein tyrosine phosphatase 1B inhibition in a cell-free assay (IC₅₀ of 11.8 µg/mL). Fractionation of this bioactive extract led to the isolation of seven known molecules belonging to the depsidones and the related diphenylethers and one new natural product, i.e., 3-butyl-3,7-dihydroxy-5-methoxy-1(3H)-isobenzofurane. The isolated compounds were evaluated for their inhibition of protein tyrosine phosphatase 1B. Two depsidones, lobaric acid and norlobaric acid, and the diphenylether anhydrosakisacaulon A potently inhibited protein tyrosine phosphatase 1B with IC₅₀ values of 12.9, 15.1, and 16.1 µM, respectively, which is in the range of the protein tyrosine phosphatase 1B inhibitory activity of the positive control ursolic acid (IC₅₀ of 14.4 µM). Molecular simulations performed on the eight compounds showed that i) a contact between the molecule and the four main regions of the protein is required for inhibitory activity, ii) the relative rigidity of the depsidones lobaric acid and norlobaric acid and the reactivity related to hydrogen bond donors or acceptors, which interact with protein tyrosine phosphatase 1B key amino acids, are involved in the bioactivity on protein tyrosine phosphatase 1B, iii) the cycle opening observed for diphenylethers decreased the inhibition, except for anhydrosakisacaulon A where its double bond on C-8 offsets this loss of activity, iv) the function present at C-8 is a determinant for the inhibitory effect on protein tyrosine phosphatase 1B, and v) the more hydrogen bonds with Arg221 there are, the more anchorage is favored.

Comet 41P/Tuttle-Giacobini-Kresak, 45P/Honda-Mrkos-Pajdusakova, and 46P/Wirtanen: Water Production Activity over 21 Years with SOHO/SWAN

In 2017, 2018, and 2019, comets 46P/Wirtanen, 45P/Honda-Mrkos-Pajdusakova, and 41P/Tuttle-Giacobini-Kresak all had perihelion passages. Their hydrogen comae were observed by the Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyman-alpha camera on the SOlar and Heliospheric Observer (SOHO) satellite: comet 46P for the fourth time and comets 45P and 41P for the third time each since 1997. Comet 46P/Wirtanen is one of a small class of so-called hyperactive comets whose gas production rates belie their small size. This comet was the original target comet of the Rosetta mission. The Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyman-alpha camera on the SOlar and Heliospheric Observer (SOHO) satellite observed the hydrogen coma of comet 46P/Wirtanen during the apparitions of 1997, 2002, 2008, and 2018. Over the 22 years, the activity decreased and its variation with heliocentric distance has changed markedly in a way very similar to that of another hyperactive comet, 103P/Hartley 2. Comet 45P/Honda-Mrkos-Pajdusakova was observed by SWAN during its perihelion apparitions of 2001, 2011, and 2017. Over this time period the activity level has remained remarkably similar, with no long-term fading or abrupt decreases. Comet 41P/Tuttle-Giacobini-Kresak was observed by SWAN in its perihelion apparitions of 2001, 2006, and 2017 and has decreased in activity markedly over the same time period. In 1973 it was known for large outbursts, which continued during the 2001 (2 outbursts) and 2006 (1 outburst) apparitions. However, over the 2001 to 2017 time period covered by the SOHO/SWAN observations the water production rates have greatly decreased by factors of 10-30 over corresponding times during its orbit.

Salazinic Acid-Derived Depsidones and Diphenylethers with α-Glucosidase Inhibitory Activity from the Lichen Parmotrema dilatatum

Three new depsidones, parmosidones F - G (1 - 2), and 8'-O-methylsalazinic acid (3), and 3 new diphenylethers, parmetherines A - C (4 - 6), together with 2 known congeners were isolated from the whole thalli of Parmotrema dilatatum, a foliose chlorolichen. Their structures were unambiguously determined by extensive spectroscopic analyses and comparison with literature data. The isolated polyphenolics were assayed for their α-glucosidase inhibitory activities. Newly reported benzylated depsidones 1: and 2: in particular inhibited α-glucosidase with IC₅₀ values of 2.2 and 4.3 µM, respectively, and are thus more potent than the positive control, acarbose.

A database of high-resolution MS/MS spectra for lichen metabolites

While analytical techniques in natural products research massively shifted to liquid chromatography-mass spectrometry, lichen chemistry remains reliant on limited analytical methods, Thin Layer Chromatography being the gold standard. To meet the modern standards of metabolomics within lichenochemistry, we announce the publication of an open access MS/MS library with 250 metabolites, coined LDB for Lichen DataBase, providing a comprehensive coverage of lichen chemodiversity. These were donated by the Berlin Garden and Botanical Museum from the collection of Siegfried Huneck to be analyzed by LC-MS/MS. Spectra at individual collision energies were submitted to MetaboLights (https://www.ebi.ac.uk/metabolights/MTBLS999) while merged spectra were uploaded to the GNPS platform (CCMSLIB00004751209 to CCMSLIB00004751517). Technical validation was achieved by dereplicating three lichen extracts using a Molecular Networking approach, revealing the detection of eleven unique molecules that would have been missed without LDB implementation to the GNPS. From a chemist's viewpoint, this database should help streamlining the isolation of formerly unreported metabolites. From a taxonomist perspective, the LDB offers a versatile tool for the chemical profiling of newly reported species.

UV-Vis Spectroelectrochemistry of Oleuropein, Tyrosol, and p-Coumaric Acid Individually and in an Equimolar Combination. Differences in LC-ESI-MS2 Profiles of Oxidation Products and their Neuroprotective Properties

Major phenolic compounds from olive oil (ArOH-EVOO), oleuropein (Ole), tyrosol (Tyr), and p-coumaric acid (p-Cou), are known for their antioxidant and neuroprotective properties. We previously demonstrated that their combination could potentiate their antioxidant activity in vitro and in cellulo. To further our knowledge of their electron-transfer properties, Ole, Tyr, and p-Cou underwent a spectroelectrochemical study, performed either individually or in equimolar mixtures. Two mixtures (Mix and Mix-seq) were prepared in order to determine whether distinct molecules could arise from their simultaneous or sequential oxidation. The comparison of Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry (LC-ESI-MS2) profiles highlighted the presence of specific oxidized products found in the mixes. We hypothesized that they derived from the dimerization between Tyr and Ole or p-Cou, which have reacted either in their native or oxidized forms. Moreover, Ole regenerates when the Mix undergoes oxidation. Our study also showed significant neuroprotection by oxidized Ole and oxidized Mix against H2O2 toxicity on SK-N-SH cells, after 24 h of treatment with very low concentrations (1 and 5 nM). This suggests the putative relevant role of oxidized Ole products to protect or delay neuronal death.

A Survey of Water Production in 61 Comets from SOHO/SWAN Observations of Hydrogen Lyman-alpha: Twenty-One Years 1996-2016

The Solar Wind Anisotropies (SWAN) instrument on the SOlar and Heliospheric Observatory (SOHO) satellite has observed 44 long period and new Oort cloud comets and 36 apparitions of 17 short period comets since its launch in December 1995. Water production rates have been determined from the over 3700 images producing a consistent set of activity variations over large parts of each comet's orbit. This has enabled the calculation of exponential power-law variations with heliocentric distance of these comets both before and after perihelion, as well as the absolute values of the water production rates. These various measures of overall water activity including pre- and post-perihelion exponents, absolute water production rates at 1 AU, active surface areas and their variations have been compared with a number of dynamical quantities for each comet including dynamical class, original semi-major axis, nucleus radius (when available), and compositional taxonomic class. Evidence for evolution of cometary nuclei is seen in both long-period and short-period comets.

tert-Butylphenolic Derivatives from Paenibacillus odorifer-A Case of Bioconversion

Two compounds (1) and (2) containing tert-butylphenol groups were, for the first time, produced during the culture of Paenibacillus odorifer, a bacterial strain associated with the crustose lichen, Rhizocarpon geographicum. Their entire structures were identified by one-dimensional (1D) and two-dimensional (2D) NMR and high-resolution electrospray ionisation mass spectrometry (HRESIMS) spectroscopic analyses. Among them, Compound 1 exhibited significant cytotoxicity against B16 murine melanoma and HaCaT human keratinocyte cell lines with micromolar half maximal inhibitory concentration (IC₅₀) values. Furthermore, after supplementation studies, a putative biosynthesis pathway was proposed for Compound 1 throughout a bioconversion by this bacterial strain of butylated hydroxyanisole (BHA), an antioxidant polymer additive.

Intrathalline Metabolite Profiles in the Lichen Argopsis friesiana Shape Gastropod Grazing Patterns

Lichen-gastropod interactions generally focus on the potential deterrent or toxic role of secondary metabolites. To better understand lichen-gastropod interactions, a controlled feeding experiment was designed to identify the parts of the lichen Argopsis friesiana consumed by the Subantarctic land snail Notodiscus hookeri. Besides profiling secondary metabolites in various lichen parts (apothecia, cephalodia, phyllocladia and fungal axis of the pseudopodetium), we investigated potentially beneficial resources that snails can utilize from the lichen (carbohydrates, amino acids, fatty acids, polysaccharides and total nitrogen). Notodiscus hookeri preferred cephalodia and algal layers, which had high contents of carbohydrates, nitrogen, or both. Apothecia were avoided, perhaps due to their low contents of sugars and polyols. Although pseudopodetia were characterized by high content of arabitol, they were also rich in medullary secondary compounds, which may explain why they were not consumed. Thus, the balance between nutrients (particularly nitrogen and polyols) and secondary metabolites appears to play a key role in the feeding preferences of this snail.

Water Production Activity of Nine Long-Period Comets from SOHO/SWAN Observations of Hydrogen Lyman-alpha: 2013-2016

Nine recently discovered long-period comets were observed by the Solar Wind Anisotropies (SWAN) Lyman-alpha all-sky camera on board the Solar and Heliosphere Observatory (SOHO) satellite during the period of 2013 to 2016. These were C/2012 K1 (PanSTARRS), C/2013 US10 (Catalina), C/2013 V5 (Oukaimeden), C/2013 R1 (Lovejoy), C/2014 E2 (Jacques), C/2014 Q2 (Lovejoy), C/2015 G2 (MASTER), C/2014 Q1 (PanSTARRS) and C/2013 X1 (PanSTARRS). Of these 9 comets 6 were long-period comets and 3 were possibly dynamically new. Water production rates were calculated from each of the 885 images using our standard time-resolved model that accounts for the whole water photodissociation chain, exothermic velocities and collisional escape of H atoms. For most of these comets there were enough observations over a broad enough range of heliocentric distances to calculate power-law fits to the variation of production rate with heliocentric distances for pre- and post-perihelion portions of the orbits. Comet C/2014 Q1 (PanSTARRS), with a perihelion distance of only ~0.3 AU, showed the most unusual variation of water production rate with heliocentric distance and the resulting active area variation, indicating that when the comet was within 0.7 AU its activity was dominated by the continuous release of icy grains and chunks, greatly increasing the active sublimation area by more than a factor of 10 beyond what it had at larger heliocentric distances. A possible interpretation suggests that a large fraction of the comet's mass was lost during the apparition.

Tsavoenones A–C: unprecedented polyketides with a 1,7-dioxadispiro[4.0.4.4]tetradecane core from the lichen Parmotrema tsavoense

Three racemic polyketides with a novel scaffold are reported from the lichen Parmotrema tsavoense.

NMR reassignment of stictic acid isolated from a Sumatran lichen Stereocaulon montagneanum (Stereocaulaceae) with superoxide anion scavenging activities

The phytochemical study of Stereocaulon montagneanum harvested in Sumatra (Indonesia) led to the isolation of 11 known compounds including two metabolites not previously described in the genus Stereocaulon, peristictic acid (8) and menegazziaic acid (10). The complete 1H and 13C NMR spectral assignments of stictic acid derivatives are reported with some revisions. Five depsidones belonging to the stictic acid chemosyndrome were superoxide anion scavengers as potent as ascorbic acid and with no toxicity on two human cell lines.

Minor Pyranonaphthoquinones from the Apothecia of the Lichen Ophioparma ventosa

Four new quinonoid naphthopyranones, ophioparmin (1), 4-methoxyhaemoventosins (2a and 2b), and 4-hydroxyhaemoventosin (3), together with anhydrofusarubin lactone (4) and haemoventosin (5) were isolated from the fruiting bodies of Ophioparma ventosa, a crustose lichen. Their structures were determined by spectroscopic analyses, and the absolute configurations of 1 and 2 were elucidated through experimental and calculated electronic circular dichroism analyses. Compounds 1, 2, and 5 exhibited moderate to strong antioxidant activities. The main pigment haemoventosin exhibited significant cytotoxicity toward a panel of nine cell lines.

Correlation between imaging and prognostic factors: molecular classification of breast cancers

The new molecular classification of breast cancers defines cancer sub-groups with a distinct prognosis and response to treatment. Studies on the literature deal with the imaging of each tumour sub-type. The radiologist should be familiar with them in order to adapt the care of an aggressive sub-type. In view of the current knowledge, the following have been significantly more often observed: mammographical spiculated mass with echogenic halo in luminal A sub-type; architectural distortion in luminal B sub-type; an irregular mass with indistinct margin comprising microcalcifications, with an abrupt interface in the sonography, or non-sonographic mass in the HER2 sub-type; a very hypoechogenic, lobulated mass with indistinct or microlobulated margin, with an abrupt interface, sometimes pseudo-benign, in the triple-negative sub-type.

Correlation between imaging and molecular classification of breast cancers

The histological type of tumour according to the WHO: ductal, lobular, rare forms, is correlated with specific aspects of the imaging based on each type. This morphological classification was improved by knowledge of the molecular anomalies of breast cancers, resulting in the definition of cancer sub-groups with distinct prognoses and different responses to treatment: luminal A, luminal B, HER2 positive, basal-like, triple-negative. Studies are beginning to deal with the appearance of each sub-type in the imaging. It is now important for the radiologist to be familiar with them.

Radiological features of triple-negative breast cancers (73 cases)

OBJECTIVES

Triple-negative breast cancers generally occur in young women and they have the potential to be aggressive. It is important for this subtype of tumour to be detected early. We studied the appearance of 73 tumours on mammography, sonography and MRI in order to determine what specific features they showed on imaging.

PATIENTS AND METHODS

From July 2009 to December 2010, we retrospectively reviewed mammogram and sonogram images of 73 triple-negative cancers. Colour Doppler had been used to depict vascularisation in 34 cases and elastography score calculated in 17 cases. Sixteen patients had undergone MRI. The radiological description of these different modalities draws on the BI-RADS lexicon and categorisation.

RESULTS

On mammography, triple-negative cancers often presented as a round mass (59.3%) or an oval or lobulated mass (65%), with circumscribed (15%), microlobulated (12.5%), indistinct (55%) or occasionally spiculated margins (15%). On sonography, the vast majority of these cancers appeared as masses (92.8%) with occasional posterior acoustic attenuation (22.6%). MRI showed more suspicious images than the standard examinations, notably rim-enhancement (eight out of 12 masses).

CONCLUSION

. Radiological images appear as lobulated masses more readily, while on sonography posterior enhancement is shown more often than attenuation, and MRI finds rim-enhancement.

The inflammatory breast: management, decision-making algorithms, therapeutic principles

Inflammatory syndrome is one of the rare emergency breast situations. Its etiology is benign, infectious in most cases. The clinical examination is often self-evident and suggests the diagnosis. But alone it is insufficient, and diagnostic tests are necessary to guide therapy. As essential as it is, mammography's limitations reinforce the benefit of ultrasonography, which in all cases reveals an abscess and has greater sensitivity for detecting a malignant tumor. If the etiology is benign, clinical signs will disappear with medical treatment, with no need for further investigation. While it is legitimate to initiate a trial treatment, it must not delay oncologic management, because of the severity of inflammatory cancer.

Composition and organization of the SCZ: a large germinal layer containing neural stem cells in the adult mammalian brain

Two known germinal zones continue to generate new neurons and glia in the adult mammalian brain: the subventricular zone (SVZ), lining the lateral walls of the lateral ventricle, and the subgranular zone of the dentate gyrus. Here we describe a region we will refer to as the subcallosal zone (SCZ). The SCZ is a caudal extension of the SVZ that is no longer associated to an open ventricle. It lies between the hippocampus and the corpus callosum. Cells isolated from the SCZ and cultured as neurospheres behave as neural stem cells in vitro. Using electron and light microscopy, we describe the cell types present in this region and how their organization differs from that of the SVZ. Using retroviral labeling and homotypic-homochronic microtransplantation techniques, we show that the majority of cells born in the SCZ migrate into the corpus callosum to become oligodendrocytes in vivo. This study defines the organization and fate of cells born in a large germinal region of the adult forebrain.

Comparative bioavailability study of zidovudine administered as two different tablet formulations in healthy adult subjects

AIM

Zidovudine is a synthetic nucleoside analogue of thymidine with activity against the human immunodeficiency virus type 1 (HIV-1). In patients with HIV infections or the acquired immunodeficiency syndrome (AIDS), zidovudine is a first-line therapy that was shown to reduce morbidity, mortality, and hospitalization. A generic formulation of zidovudine offers the possibility of considerable savings to HIV/AIDS patients in developed and Third World countries. The objective of the current study was to characterize the pharmacokinetic and safety profiles of zidovudine administered as a generic tablet formulation relative to the innovator product.

VOLUNTEERS AND METHODS

A total of 68 healthy adult volunteers received a 300 mg oral dose of zidovudine as the generic formulation (AVIRO-Z 300 mg tablet, Ranbaxy Laboratories Limited) and as the innovator product (Retrovir tablet, GlaxoSmithKline) in a randomized, 2-way crossover study. Multiple blood samples were collected over 12 hours and plasma concentrations of zidovudine were assayed using an LC/MS/MS method with an analytical range of 5.00 to 2,000 ng/ml. Pharmacokinetic parameters were calculated using non-compartmental methods.

RESULTS

Mean plasma concentrations of zidovudine declined in a mono-exponential manner, with mean concentration values falling below the limit of quantitation 12 hours after administration of both formulations. Mean area under the curve from time 0 to the last measurable concentration (AUC(0-t)), mean area under the curve from time 0 to infinity (AUC(0-infinity)) and peak plasma concentrations (C(max)) of zidovudine for the generic tablet formulation (2,220.6 ng x h/ml, 2,236.0 ng x h/ml and 1,087.9 ng/ml, respectively) were very similar to those observed for the innovator product (2,139.7 ng x h/ml, 2,158.6 ng x h/ml and 1,066.5 ng/ml, respectively). Ratios of least-squares means and 90% confidence intervals of AUC(0-t) AUC(0-infinity) and C(max) between the 2 formulations were within 80-125%, suggesting that the two tablet formulations displayed similar rate and extent of bioavailability. The oral clearance (CL/F) of zidovudine for the generic and innovator formulations were 2.11 1/h/kg and 2.16 1/h/kg, respectively. For the two formulations, adverse events were similar in nature and frequency.

CONCLUSION

Since the two formulations displayed similar in vivo delivery rate of zidovudine in the bloodstream, the generic tablet formulation of zidovudine developed by Ranbaxy should be equally effective as the innovator product and is expected to produce considerable cost-savings in AIDS patients worldwide.

Deflection of the interstellar neutral hydrogen flow across the heliospheric interface

Using an absorption cell, we measured the Doppler shifts of the interstellar hydrogen resonance glow to show the direction of the neutral hydrogen flow as it enters the inner heliosphere. The neutral hydrogen flow is found to be deflected relative to the helium flow by about 4 degrees . The most likely explanation of this deflection is a distortion of the heliosphere under the action of an ambient interstellar magnetic field. In this case, the helium flow vector and the hydrogen flow vector constrain the direction of the magnetic field and act as an interstellar magnetic compass.

Effects of transdermal estrogens on endothelial function in postmenopausal women with coronary disease

OBJECTIVE

Oral estrogens improve endothelial function, and for this reason may be considered cardioprotective; however, in women with coronary heart disease there may also be an increase in the risk of thrombosis. Although transdermal estrogen administration may decrease this adverse effect, there are few data on endothelial function in women with coronary heart disease treated using such therapy. This study aimed to report the endothelial response in postmenopausal women with coronary heart disease treated with transdermal estrogen.

MATERIALS AND METHODS

This was a double-blind, prospective, randomized study. Eighteen patients with a history of acute coronary syndrome and nine healthy women were studied over 4 weeks. Coronary patients were assigned at random to receive a patch containing either 50 microg estradiol or placebo on a weekly basis. Endothelial function was assessed by flow-mediated vasodilatation of the brachial artery. Baseline blood flow (brachial artery diameter) was measured after 30 min rest and following ischemia, prior to treatment and after 4 weeks.

RESULTS

Flow-mediated vasodilatation in normal patients was 17.8%, whereas in women with coronary disease it was 1.2% (p = 0.0001). Arterial diameter for the resting period in coronary disease subjects increased from 4.22 +/- 0.59 to 4.41 +/- 0.56 mm (p < 0.004) after 4 weeks of estrogen therapy, whereas, in women receiving placebo, it did not change. Flow-mediated vasodilatation in the estrogen group was 3.4% and in the placebo group was 0.5% (p = 0.05).

CONCLUSIONS

Transdermal estrogen may improve endothelial function in women with coronary heart disease.

Anterior Zielke instrumentation for spinal deformity in adults

Fifty-eight adults who had scoliosis or hyperlordosis had anterior arthrodesis and Zielke instrumentation. Postoperatively, the curve improved 68 per cent in forty-nine patients who had idiopathic scoliosis and 40 per cent in nine patients who had paralytic scoliosis or hyperlordosis or congenital scoliosis. More correction was obtained when a derotator apparatus was used. Only one patient had failure of the instrumentation that necessitated additional surgical treatment. All of the arthrodeses resulted in osseous fusion. No patient who had idiopathic scoliosis lost correction (average follow-up, forty-two months; range, thirty to seventy-eight months). There were no serious complications. Lumbar lordosis decreased an average of 24 per cent compared with the preoperative measurement. This decrease was thought to be related to the correction of vertebral rotation in the curve and to the surgical technique. Use of the Zielke instrumentation resulted in excellent correction, which was not lost postoperatively in the patients who had an idiopathic curve and which was associated with minimum complications.

Ontogeny of murine I-Ak antigens in tissue of nonlymphoid origin

The ontogeny of I-Ak antigens in murine tissues of nonlymphoid origin has been evaluated by reacting acetone-fixed cryostat sections of embryonic, neonate, and adult tissues with the MOAb 10-2.16 in indirect immunofluorescence. Thymus dendritic cells appear to be the first to express I-Ak antigens which become detectable only after birth in skin Langerhans cells, gastrointestinal epithelium, septal cells in lung alveoli, and some endothelia. The full expression of I-Ak antigens as detected in adult mice is reached only at 1 month of age.