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.

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.

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.

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.

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.