Discovering New Natural Products Using Metabolomics-Based Approaches.

The incessant search for new natural molecules with biological activities has forced researchers in the field of chemistry of natural products to seek different approaches for their prospection studies. In particular, researchers around the world are turning to approaches in metabolomics to avoid high rates of re-isolation of certain compounds, something recurrent in this branch of science. Thanks to the development of new technologies in the analytical instrumentation of spectroscopic and spectrometric techniques, as well as the advance in the computational processing modes of the results, metabolomics has been gaining more and more space in studies that involve the prospection of natural products. Thus, this chapter summarizes the precepts and good practices in the metabolomics of microbial natural products using mass spectrometry and nuclear magnetic resonance spectroscopy, and also summarizes several examples where this approach has been applied in the discovery of bioactive molecules.

Discovery of dual PKS involved in sclerotiorin biosynthesis in Penicillium meliponae using genome mining and gene knockout.

Fungi of the genus Penicillium section Sclerotiora have as their main characteristic the presence of orange-pigmented mycelium, which is associated with sclerotiorin, a chlorinated secondary metabolite of the azaphilone subclass of polyketides. Sclerotiorin presents anti-diabetes, antioxidant, anti-inflammatory, anti-Alzheimer, antiviral, and antimicrobial activities, which has always attracted the attention of researchers worldwide. During our ongoing search for azaphilone-producing Amazonian fungi, the strain of Penicillium MMSRG-058 was isolated as an endophyte from the roots of Duguetia stelechantha and showed great capacity for producing sclerotiorin-like metabolites. Using multilocus phylogeny, this strain was identified as Penicillium meliponae. Moreover, based on the genome mining of this strain through the reverse approach, a cluster of putative biosynthetic genes (BGC) responsible for the biosynthesis of sclerotiorin-like metabolites (scl cluster) was identified. The knockout of the sclA (highly reducing PKS) and sclI (non-reducing PKS) genes resulted in mutants with loss of mycelial pigmentation and terminated the biosynthesis of sclerotiorin-like metabolites: geumsanol B, chlorogeumsanol B, 7-deacetylisochromophilone VI, isochromophilone VI, ochrephilone, isorotiorin, and sclerotiorin. Based on these results, a biosynthetic pathway was proposed considering the homology of BGC scl genes with the azaphilone BGCs that have already been functionally characterized.

The Amazonian kambô frog Phyllomedusa bicolor (Amphibia: Phyllomedusidae): Current knowledge on biology, phylogeography, toxinology, ethnopharmacology and medical aspects.

Phyllomedusa bicolor (Phyllomedusidae), popularly known as the kambô in Brazil, is a tree frog that is widely distributed in South American countries and is known for producing a skin secretion that is rich in bioactive peptides, which are often used in indigenous rituals. The biological effects of the skin secretion were observed in the first studies with indigenous communities. Over the last six decades, researchers have been studying the chemical composition in detail, as well as the potential pharmacological applications of its constituents. For this reason, indigenous communities and health agents fear the misuse of the kambô, or the inappropriate use of the species, which can result in health complications or even death of users. This article seeks to provide a transdisciplinary review that integrates knowledge regarding the biology of P. bicolor, ethnoknowledge about the ritual of the kambô, and the chemistry and pharmacology of the skin secretion of this species, in addition to medical aspects of the indiscriminate use of the kambô. Furthermore, this review seeks to shed light on perspectives on the future of research related to the kambô.

Breast specimen lumpectomy orientation: which technique is the best?

The authors report a cheap, simple, reliable and reproducible technique of breast specimen lumpectomy orientation.

Uterine metastases from primary breast-cancer - report of 2 cases.

The authors report on 2 cases of uterine dissemination from primary breast carcinoma. Special emphasis is made on this atypical site of metastases and on the necessity of a gynecological work-up in patients previously treated for breast cancer.

[Validation of the measurement of hepatic volume by three-dimensional computed tomography]. / Validation de la mesure d'un volume hépatique par scanographie tridimensionnelle.

The aim of this work was to verify experimentally the reliability of 3D CT scan in measuring hepatic volumes. Eight livers were dissected from corpses. The referring liver volume was determined by measure of its hydric shift. The correlation coefficient R was 0.93 (p < 0.001) on 5 mm/5 mm 3D sections, 0.92 (p < 0.001) on 10 mm/10 mm 3D sections and 0.94 (p < 0.0006) on 5 mm/10 mm 3D sections. The paired t-test also showed a 5% risk correlation between the two measurements. Although in vivo imaging is slightly different from in vitro, 3D CT scan seems to be a reliable method to determine an hepatic volume without increased X-ray irradiation.

[190 cancers of the thyroid with a follow-up of more than 5 years]. / 190 cancers de la thyroïde. Avec plus de 5 ans de recul.

Outcome in 190 patients operated upon by first intention for thyroid cancer is analyzed after follow up over more than 5 years. No deaths due to cancer occurred in 57 cases of papillary cancer, but 7 cases presented pulmonary metastases, while the global-5-year survival rate in 63 cases of vesicular cancer (including 25% with preoperative metastases) was 60%. In the absence of preoperative metastases, ans if well differentiated forms are separated from moderately differentiated forms, the respective 5-year survivals were 88 and 45%. The 1-year survival rate for the 42 cases of anaplastic cancer was 15%, while the 5-year rate for 15 cases of medullary cancer was 80%.

[Study by radioactive microspheres of bone microcirculation in aseptic osteonecrosis of the femoral head]. / Etude par microsphères radioactives de la microcirculation osseuse dans l'ostéonécrose aseptique de la tête fémorale.

Thirty-two hips affected by aseptic necrosis, four of them post-traumatic and 12 contralateral hips thought to be healthy have been studied by combining superselective arteriography with the injection of radioactive microspheres. It has been possible to show that aseptic necrosis begins with a global ischaemia and is followed by an incomplete revascularisation leaving a necrotic area. On the border between the two areas hypervascularity produces a zone of fragility where microfractures develop with detachment of a sequestrum. The presumed opposite hip is almost always, even in traumatic lesions, the site of a hypovascularity which seems to suggest a predisposition to the lesion. There is a correlation between radiological and clinical worsening and the development of revascularisation in the femoral head.

Detection of right ventricular pressure overloading by thallium-201 myocardial scintigraphy. Results in 57 patients with chronic respiratory diseases.

The diagnostic value of thallium 201 (201Tl) myocardial imaging was studied in 57 patients with chronic respiratory diseases, most with COPD (n = 46), by comparing the results to hemodynamic findings. In healthy subjects, the right ventricle (RV) is not visualized; therefore, any recorded activity of the RV was considered as indicating RV hypertrophy due to RV pressure overloading (RVPO). RV activity was graded from 0 (no activity) to 3 (activity greater than or equal to that of the left ventricle). Patients were divided into three groups according to the level of the pulmonary artery mean pressure (PPA): PPA less than or equal to 20 mm Hg (no pulmonary arterial hypertension [PAH] ) = group 1, n = 20; PPA ranging from 21 to 30 mm Hg (mild to moderate PAH) = group 2, n = 20; PPA greater than 30 mm Hg (marked PAH) = group 3, n = 17. RV was visualized in 14 patients in group 3 (82 percent) and in 13 patients in group 2 (65 percent). For all patients with PAH (2 + 3) the sensitivity of 201Tl imaging for the diagnosis of RVPO was of 73 percent, higher than that of ECG and echocardiography (both 51 percent). The sensitivity of 201Tl, even if moderate (65 percent) was better than that of ECG (30 percent) or echo (40 percent) in patients with mild-to-moderate PAH (group 2). A high RV activity (grade 3) was observed in only three patients. The specificity of this method (obtained from results in group 1) was of 80 percent vs 89 percent for echo and 100 percent for ECG. These results suggest that 201Tl myocardial imaging is a rather sensitive method and could be of interest for the noninvasive diagnosis of RVPO in COPD patients.

Relationship between pulmonary artery mean pressure and the vertical gradient of perfusion in chronic respiratory diseases.

The relationship between mean pulmonary artery pressure (PPA) and the regional distribution of perfusion, investigated with 133Xe, was studied in 67 patients with chronic respiratory diseases, including 57 patients with chronic obstructive pulmonary disease. The vertical gradient of perfusion, assessed by the ratio upper/lower perfusion (RQ), was considered as normal when RQ was less than or equal to 0.85. Patients were divided into three groups: no pulmonary hypertension, mild hypertension, moderate to severe hypertension. RQ was normal in the majority of patients, even in the group with PPA greater than 30 mm Hg. The average values of RQ did not significantly differ from one group to another. There was no correlation between PPA or pulmonary vascular resistance and RQ. These results suggest that the vertical gradient of perfusion is generally conserved and that the distribution of perfusion cannot provide any reliable prediction of pulmonary hypertension in chronic obstructive pulmonary disease.

[Regional pulmonary function in unilateral sero-fibrinous pleural effusions and changes under the influence of treatment (author's transl)]. / La fonction pulmonaire régionale au cours des pleurésies séro-fibrineuses unilatérales et son évolution sous traitement.

The regional distribution of ventilation (Vr), perfusion (Qr) (expressed in absolute values) and the regional distribution of ventilated lung volume, of ventilation and of perfusion (expressed as %) were studied using Xenon 133 in 13 subjects with a unilateral pleural effusion of proven or presumed tuberculous origin. The examinations were performed in a sitting position. The initial examination was carried out after as complete an evacuation as possible of the fluid effusion. Eight subjects underwent a follow-up examination after two months treatment with tuberculostatic agents combined with daily respiratory physiotherapy. The initial results emphasized the following points: - in absolute values, a deficit in ventilation on the involved side affecting the 3 regions explored without any similar change in perfusion ; a hyperventilation on the controlateral upper and middle regions ; - in relative values, a slight deficit in ventilated volume and perfusion localised at the base, whilst the deficit in ventilation was more marked and more extensive. After treatment the contribution to ventilation of the involved side increased on average by 6%. However this improvement only concerned the lower territory. The mechanisms of impairment of regional function and its improvement under the influence of treatment are discussed.

[Recent advances in isotopic exploration of the skeletal system in prostate cancer (author's transl)]. / Mise au point sur les explorations isotopiques du squelette dans les cancers de la prostate.

Skeletal isotopic exploration is fundamental in patients with prostatic cancer. Bone scintiscan is reliable. Its sensibility can be increased by using new radioactive isotopes and quantitative isotopic explorations. Bone marrow histologic study is indicated in case of a doubtful diagnosis, when there is a discordance between radiological and isotopic exploration.

Radionuclide computerized ventilation studies.

Studies of regional lung function have developed rapidly in the last few years. Xenon -133 is the most frequently used isotope because of its physiocochemical and biologic properties. Fixed counters are being replaced by the scintillation camera interfaced to a computer allowing easy acquisition and interpretation of results and numerical data. The use of isotopes other than 133Xe, such as 81mKr, is less widespread. In this article, a method is described for studying regional ventilation in which the isotope used is 133Xe, the radioactivity is recorded by a scintillation camera, interfaced to a computer andsix (or 12) regions for both lungs are selected and investigated. The regional ventilation is expressed as an absolute value in ml/min/ml of ventilated volume as well as the relative contribution in percent of each zone to the total ventilation and volume. To illustrate this method, the results are reported for healthy subjects and for patients with chronic bronchitis and emphysema. Scintigraphs of individual cases are presented. Certain theoretic problems related to calculation of regional ventilation are discussed.

[The regional exploration of pulmonary function using xenon 133. Value of the gamma camera connected to a computer (author's transl)]. / Exploration régionale de la fonction pulmonaire par le xénon 133. Intérêt de la gamma caméra couplée à l'ordinateur. Résultats dans les bronchopneumopathies chroniques obstructives.

Regional isotopic exploration of ventilation and pulmonary perfusion is not yet widely applied in clinical practice, by virtue of the complexity of the equipment required, but also because of the complicated and lengthy analysis of the results. In this respect, connection of the scintillation camera to a computer represents a major advance which other authors have already emphasized. Our own experience in this area and our method of exploration are described. The results of regional exploration in a group of 43 cases of chronic obstructive lung disease (33 patients of the chronic bronchitis type, 10 patients with emphysema) are analysed and discussed. The results indicate the following : in chronic bronchitis, a very marked fall in ventilation of the bases with inversion of the normal vertical ventilation gradient, and a fall in the ventilation/perfusion ratio of the bases; in emphysema, a fall in ventilation, but also and above all in regional perfusion of all territories with preservation of normal or even increased regional ventilation/perfusion ratios. Regional exploration may also be of value in the detection of early stages of obstructive lung disease, and in pre-operative assessment in thoracic surgery.