Action de l'antimycine a sur l'activité succinoxydase des mitochondries du tubercule de Pomme de Terre,et comportement des cytochromes de type b

A kinetic study of the effect of antimycin A on succinate oxidase from plant mitochondria produced sigmoidal curves for the reduction of cytochromes b₅₆₀ and b₅₈₅ and for the inhibition of succinate oxidase. In the stationary state the interaction of the various components of the respiratory chain (flavins, ubiquinone, cytochromes…) occurs in a sequential mode which allows the application of simple equations utilizing rate constants and cytochrome concentrations. In these equations, it is assumed that there exists an excess of ubiquinone relative to other components of the respiratory chain as suggested by Kröger & Klingenberg (1970) and that the reoxidation of b cytochromes is fast. The inhibition by antimycin A, characterized by non-linear inhibition curves for succin-oxidase and inhibitor fixation in complex III on a component other than cytochrome c₁, is interpreted in terms of this model. This hypothesis presupposes the existence of an F factor between cytochrome b₅₆₀ and cytochrome c₁ as suggested by other authors. Utilizing these equations, theoretical curves for the inhibition of the reduction of cytochrome b₅₆₀ have been constructed and the results agree with the experimental data. The kinetic behavior of cytochrome b₅₆₆ during the induction of anaerobiosis suggests that it is not directly involved in the electron transfer chain but rather is either in thermodynamic equilibrium with cytochrome b₅₆₀ or in a shunt between cytochrome b₅₆₀ and factor F. From the experimental data, an equation is derived for the inhibition of the reduction of cytochrome b₅₆₆ by antimycin A. The actual effects of ATP and mClCCP on succinoxidase agree well with those predicted by the model.     

Phenols bromes des algues rouges: Cyclotribromoveratrylene,nouveau derive obtenu au cours de l'extraction de Halopytis pinastroïdes

Cyclotribromoveratrylene has been isolated from an ethanolic extract of fresh Halopytis pinastroïdes, after treatment with diazomethane. This new     

Conclusion. Bilan des recherches interdisciplinaires effectuées sur le site de l’Homo erectus de Denizli,Kocabaş, Bassin de Denizli,Anatolie, Turquie. L’Homo erectus aux portes de l’Europe

The study of the site of Kocaba?, which yielded an archaic Homo erectus skullcap, was undertaken in 2011 and 2012, at the request of Professor Mehmet Cihat Alçiçek. This interdisciplinary French–Turkish research programme comprised the geochronological, magnetostratigraphic, biochronological and paleoenvironmental study of the site and the paleoanthropological study of the skullcap itself. The association of large mammals enabled us to attribute the travertine formations bearing the skullcap to the second part of the Upper Pleistocene, and more specifically to between 1.5 and 1.2 million years, because of the disappearance or appearance of certain species. This biochronological age is confirmed by the paleomagnetism study, which places the travertines bearing the skullcap in a period of reversed polarity, underlying a normal polarity formation, which could be attributed to the Cobb Mountain paleomagnetic excursion, dated to 1,194,000 years. The dating of these fauna by the ²⁶Al/¹⁰Be cosmogenic nuclide method by Anne-Elisabeth Lebatard yielded an age older than 1.22 Ma and more recent than 1.5 Ma. The Hominid skullcap from this formation can be attributed to a Homo erectus, slightly more evolved than those of Homo ergaster KNM-ER 3733 (1.78 Ma) and KNM-ER 15,000 (1.5 Ma), similar to that of Daka (Bouri), which is about a million years old and older than the Bodo fossil (estimated at 600,000 years) and Kabwe (between 300,000 and120,000 years). The archaic Homo erectus skullcap from Kocaba?, referred to as Denizli Man, proves that Homo erectus was already present in Anatolia, at the crossroads of Africa, Asia and Europe, a little more than 1.2 million years ago.     

Datation des travertins de Kocabaş par la méthode des nucléides cosmogéniques Al/Be

The archaic Homo erectus Kocaba? skullcap was discovered at Kocaba?, Denizli, Turkey in travertine formations over- and underlain by conglomerate formations. These units dated by the ²⁶Al/¹⁰Be cosmogenic nuclide method constrained the skullcap age between 1.0 and 1.6 Ma.     

Donnees nouvelles sur l'age des formations lacustres des bassins de Narbonne — Sigean et de leucate (aude) a l'aide des micromammiferes

Discovery of fossil rodents of oligocene and lower miocene age (Aquitanian) in the Narbonne — Sigean basin, and of pliocene age at the Leucate plateau and cliff.     

Radioprotection de l’entourage des patients traités à l’iode 131 pour des cancers différenciés de la thyroïde : comparaison de deux méthodes d’estimation des temps de restriction de contact

In France, it is required to give patients some written radiation safety advice following an iodine-131 therapy of thyroid. However, there is no regulatory methodology proposed to assess the restriction times required to limit radiation dose received by their family and by third persons. In this study, we compared two methods to perform the calculation of restriction times for differentiated thyroid cancer: the first one, called Global method, follows general recommendations and the second one, called PaDe method, provides customized recommendations based on the effective half-life measured for each patient during the 48 h of hospitalization. For these simulations, the input parameters for both methods were dose constraints, contact patterns, final dose rate measurement at discharge of the patient, effective half-life and dose rate variation with distance. For the Global method, these parameters were set and were not changed. For the PaDe method, the effective half-life and the final dose rate were adjusted for each patient. Comparison between the two methods was carried out for 103 patients. For 68.0 % of the patients, no restrictions were necessary according to the PaDe method whereas the Global method required restrictions to be applied during up to 2 days. For almost 16.5 % of them, restriction times estimated with the PaDe method were systematically lower. For the remaining 15.5 %, at least one contact pattern restriction had to be increased according to the PaDe method. Furthermore, with the Global method, the same instructions were given to 97.0 % of the patients. These results showed the limits of the Global method which does not consider individually tailored biological data. Eventually, the use of the personalized PaDe method optimizes the radiation protection by improving the well being of the patient or reinforcing the family and third person's protection.     

Quid des produits de contraste en TEP/TDM ?

It is important that PET/CT in its current technical form is used to its fullest clinical capability. In order to achieve this, training has to be such that PET/CT readers are capable PET as well as CT readers. Imaging protocols have to be devised such that contrast media enhancement in CT minimizes artefacts since the CT data are also used for attenuation correction. The easiest and most flexible way is to perform a low dose pre-PET/CT scan and add a CE-CT at the end of the examination, if necessary. Necessity is dictated by the clinical question and clinical experience is accumulating telling us that depending on the question asked from the PET/CT examination, CE is mandatory, recommended, optional or unnecessary.     

En France, la majorité des donneurs de spermatozoïdes souhaite le maintien de leur anonymat

So far in France, sperm donor anonymity, which was a fundamental principle and has been twice confirmed in the law in 1994 and 2004, is debated nowadays. In this context, the Cecos wanted to know the donors opinion on anonymity. In 2006, 193 semen donors recruited in 14 Cecos answered anonymously a questionnaire: 73% were in agreement with the principle of anonymity and less than 30% agreed that the future law should change to allow the children to know the donor identity. In case of anonymity disclosure, 60% would give up their sperm donation. The same proportion of donors would accept that non identifying information on them could be given on request to the parents and the child.     

Alcaloïdes des feuilles de Holarrhena febrifuga

Leaves of Holarrhena febrifuga from East Africa contain 1·5% of alkaloids, mostly of the amino-3α ceto-20 pregnane-5α type. Six alkaloids have been isolated: funtumine (I), holamine (II), dimethyl- and monomethyl-funtumine (Ia) and (Ib), dimethyl- and monomethylholamine (IIa) and (IIb); these methyl derivatives have been isolated for the first time from natural source. Pregnane-3,20-dione has been isolated from the same leaves.     

Perspectives de l’analyse de la mobilité des spermatozoïdes

Several studies have shown a good correlation between sperm motility and fertility though the microscopic evaluation of the percentage of motile sperm is highly subjective by nature. Therefore in the last decade, various objectives methods have been proposed to overcome this problem. Two types of methods were developed: The methods based on the analysis of images obtained by microphotography, microcinematography and microvideography and the global, undirect methods based on physical principles. Several systems based on video and image analysis (Computer Aided Sperm Analysis, CASA) have been developed and are used in numerous laboratories of reproductive biology. CASA technology offers the possibility to analyse some characteristics of sperm motion which are related to the fertilization potential and to develop new parameters related to some important aspects of sperm behavior such as hyperactivation. However, there is a large amount of interactions between the operator and the CASA machine. CASA instruments are not “ready-to-use” robots: the reliability of CASA depends largely on the expertise and training of the user and the application of standardized procedures and quality control schemes. By contrast, there is only minimal interaction between the operator and the Sperm Quality Anlyser which is a new device measuring and index of sperm motility highly correlated to the concentration of progressively motile sperm. The device uses light passed through a small sample of semen introduced in a capillary tube to detect variations in optical density that result from moving particles. The reproducibility of the measurements is excellent, the device is easy to use and this is a potentially useful tool for field-work studies. Further investigations of this device in the managment of male infertility is warranted. Finally, both types of objectives approaches are complementary to the conventional analysis of sperm motility and they will not replace it. Standardized procedures have been proposed by the World Health Organization for the subjective evaluation of sperm motility. Such procedures are very useful to reduce significantly the intra- and interlaboratory variations but internal and external quality controls schemes indicate that they are not sufficient to achieve acceptable levels of variation and regular quality controls followed by the definition and the application of corrective procedures are required.     

13C NMR des alcaloïdes des Strychnos: Les dérivés de l'harmane et de l'usambarensine

¹³C NMR spectra of some tertiary and quaternary indole alkaloids are recorded and the signals assigned. Graphic interpretation of off-resonance spectra and substituent shielding effects together with the effect of N_b-methylation are utilized in the spectral interpretation.     

Cancer différencié de la thyroïde métastatique à propos de 70 cas : impact des nouvelles recommandations de 2017

IntroductionMetastatic differentiated thyroid carcinoma (MDT) represents an average of 10% of patients with CDT. Metastases are prognostic factors. Their care is multidisciplinary.ObjectiveTo study the epidemiological, clinical, histological, therapeutic and evolutionary aspects of metastatic CDT and to study the impact of new recommendations.Patients and methodsRetrospective study of 70 patients followed for a metastatic CDT collected between June 2007 and June 2017, in the nuclear medicine department of Hassan II University Hospital of Fez.ResultsMean age 51.34 ± 15.96 years, sex ratio F:H: 2.5. Age > 45 years old at 65.7% of whom 42.8% > 55 years old. Circumstances of discovery: nodule 15.8%, multi-hetero-nodular goiter 17.1%, metastases 65.7%. Multivariate analysis shows a significant correlation of age greater than 45 years (P: 0,001) and revealing metastasis. Histology: papillary carcinoma 72.9%, vesicular carcinoma 22.8% and carcinoma poorly differentiated 4.3%. Tumor > 4 cm in 45.7%, the TNM classification (2010) vs. TNM classification (2017): 31.4% vs. 48.6% in stage I, 12.9% vs. 28.6% in stage II, the stage III in 17.1% vs. 0% and 38.6% vs. 22.8% in stage IV. Complementary investigations: localization of metastases: 40% at the bone level, 31.4% lung, 14.3% ganglionnaires and others 9.9%. Hormonal braking treatment was administered in all patients and the « irathérapie » (ATA vs. French recommendation 2017).EvolutionSeven cases of cure, 1 case of recurrence, 4.3% refractory to iodine.ConclusionThe presence of metastases, worsens the prognosis. Therapeutic de-escalation with French recommendations. Bone localization was predominant, its management is multidisciplinary, and radioactive iodine as a complementary treatment does not allow their healing.     

Mensurations échographiques de la thyroïde chez des enfants de zéro à 15 ans de la ville de Ouagadougou

Among the methods used to carry out measurements of thyroid, echography is the best because it is noninvasive and more specific. The goals of this study were to determine the normal thyroid volume of the Burkinabe child; to study the parameters which induce a variation of thyroid volume and to compare our values with those from other localities. Through a cross-sectional study, 240 children from the town of Ouagadougou benefited from a thyroid echography. Thus the height (h), the transverse diameter (dt) and the thickness (e) were measured. Volume (vl) of each lobe was estimated by: vl = h × dt × e × 3.14/6. The total volume (VT) is the sum of the volumes of each lobe, the isthmus being neglected. A correlation set at the threshold p < 0.001 has been carried out between VT and some anthropometric parameters. The following averages were observed: before one year, the average volume is of 0.51 L ± 0.21; from one to three years, it is of 0.95 mL ± 0.33; from four to six years, the average volume is of 1.35 mL ± 0.43; from seven to nine years, it is of 1.95 mL ± 0.62. From 10 to 12 years, the average volume is of 3.01 mL ± 1.08 and it is of 5.32 mL ± 2.07 from 13 to 15 years. It stands out that the VT is positively associated with the age (r = 0.82), with the size (r = 0.73), with the weight (r = 0.81) and with body surface (r = 0.78). Moreover, the VT is higher among boys than in girls beyond one year of age. This parameter varies according to the area of origin. Lastly, compared with the American, European and Asian averages, our values are smaller. This study enabled us to establish our own standards which we will be able from now on to use in daily practice. However, multicentric studies associated with thyroid and sexual hormones blood levels measurements must be undertaken to ascertain these data.     

Indications de la recherche des anticorps anti-spermatozoïdes

The clinical significance of antisperm antibodies (ASA) is highly controversial. A significant percentage of infertile men and women present immunity to spermatozoa, suggesting that ASA may interfere with the fertilizing capacity. ASA can act negatively on sperm parameters, sperm-cervical mucus interaction, gamete fusion and possibly also on the first step of embryonic development. ASA are present in approximately 2.8% to 26% of the male population and 0.2% to 1.6% of women. The pathogenesis of immunity to spermatozoa had not been fully elucidated: breakdown of normal protective mechanisms, i.e. blood-testis barrier, or epithelial barrier in women, and other mechanisms of immunological sperm tolerance, such as regulation of suppressor T lymphocytes. The indication for antisperm antibody testing is based on clinical and laboratory findings of infertile patients. In men, indictions for ASA testing include a history of genital disease, surgery for genital abnormalities, vasectomy, obstruction or injuries of the male genital tract, infection of accessory glands, long-standing infertility, alteration of semen parameters (agglutination, motility), mucus penetration, and reduced fertilizing capacity in IVF. In many cases, no etiological cause of autoimmunity is found and a genetic predisposition has been suggested. A majority of women do not develop antisperm antibodies, despite repeated contact with spermatozoa during their sexual life. Upper genital tract infection is the main cause of isoimmunization in females, although sexual practices, endometriosis, surgery for cervical neoplasia, recurrent spontaneous abortion and long-term infertility may also be involved. Sperm-cervical mucus impairment is the most obvious effect of immunization in women associated with IVF failure. Autoantibodies are frequently associated with antisperm antibodies. One of the consequences of the success of ICSI has been a decreased research effort to further the understanding of the origin and relevance of antisperm antibodies and specific antibody-antigen interactions. A better understanding of the natural history of immunological infertility would be useful for patient conseiling and to develop the most effective, efficient and safest management strategies. Such data could also be useful for the development of new tests and immunological methods of male contraception.     

La TEP-TDM à la F-Dopa aurait-elle un rôle dans le suivi postopératoire des patients atteints de carcinome médullaire de la thyroïde ? Résultats préliminaires de l’expérience strasbourgeoise et revue de la littérature

Aim

Retrospective study to assess the value of fluorine-18 dihydroxyphenylalanine (¹⁸F-Dopa) positron emission tomography (PET)/computed tomography (CT) in the post-surgical follow-up of patients with history of medullary thyroid carcinoma (MTC) and biological suspicion of disease relapse. A review of the literature was also performed.

Patients and methods

Ten patients (23-71 years) with MTC previously treated by surgery were examined by at least one ¹⁸F-Dopa PET/CT. All patients presented with elevated serum calcitonin (130-9076 ng/l) and/or CEA (1.2-518 ng/ml) levels. 3D whole body PET/CT was performed 45 and 120 minutes after intravenous injection of 4 MBq/kg of ¹⁸F-Dopa. Scintigraphic images were visually interpreted. For quantitative analysis, maximum standardized uptake value (SUV_max) per focus was employed. PET results were compared with histological findings and/or with the results of all other imaging procedures.

Results

Seven patients (70%) had a positive ¹⁸F-Dopa PET/CT. Twenty-five focal tracer accumulations were described. Histopathological confirmation of metastatic disease was obtained in four of the seven patients with pathologic ¹⁸F-Dopa PET/CT. No scintigraphic abnormalities were evidenced in the three other patients, whose conventional morphological imaging procedures were also negatives. Delayed PET/CT examinations didn’t increase sensitivity. No correlation between ¹⁸F-Dopa PET/CT results and both serum calcitonin and CEA levels was achieved.

Conclusion

Our results are in accordance with the existing literature, showing the potential role of ¹⁸F-Dopa PET/CT in the clinical management of patients with history of MTC and biological suspicion of relapse during post-surgical follow-up. Prospective studies including larger patient series are necessary to confirm the future place of ¹⁸F-Dopa PET/CT in follow-up of MTC.     

Contexte géographique et géologique du site de Kocabaş, Bassin de Denizli,Anatolie, Turquie

The site of Kocaba? is located in the Denizli Basin, in western Anatolia, 400 km southwest of Ankara, 360 km south of Istanbul, 200 km east-southeast of Izmir and 150 km northwest of Antalya. The Denizli Basin depression, at the junction of the Buyuk Menderes and Gediz grabens, which began to form at the beginning of the Miocene, was filled in around the edges, along fault lines, by significant travertine formations, some of which are still active today. The age of the Kocaba? travertines, which yielded the Kocaba? Homo erectus skullcap, was evaluated by thermoluminescence at 828,000 years, by electron spin resonance (ESR) at 1,110,000 years and by the ²⁶Al/¹⁰Be cosmogenic nuclide method to more than 1.22 Ma and less than 1.5 Ma, a date which has been confirmed by magnetostratigraphy and biochronology.     

Nouveaux traceurs TEMP : exemple des traceurs des protéoglycanes et de la mélanine

The majority of research program on new radiopharmaceutics turn to tracers used for positron emission tomography (PET). Only a few teams work on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma cameras should boost the development of non-PET tracers. We exhibit in this article the experience acquired by our laboratory in the conception and design of two new non fluorine labelled compounds. The ^99mTc-NTP 15-5 which binds to proteoglycans could be used for the diagnosis and staging of osteoarthritis and chondrosarcoma. The iodobenzamides, specific to the melanin, are nowadays compared to ¹⁸F-fluorodeoxyglucose in a phase III clinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on BZA heteroaromatic analogues usable for melanoma treatment.     

Reproduction de l'Omble de fontaine,Salvelinus fontinalis (Mitchill), dans des lacs de différents pH

Mn, Fe, Cu, and Cd concentrations are reported for Lake Vanda, a closed-basin, meromictic, Antarctic lake and for its single major inflow, the Onyx River. Trace metal distributions in the upper lake and annual metal fluxes from the Onyx River were used to estimate chemical residence times in the mixed zone above the chemocline. Residence times, based on total metal loads, were 9.4 years for Mn; 1.4 years for iron; 174 years for copper; and 82 years for cadmium. Controls on the steady state concentrations of metals in this system are likely to include: particle settling of Fe and Mn; scavenging of minor elements on metal oxide surfaces; sulfide precipitation from the anoxic brine; and possibly uptake of metals on the surface of benthic algal mats. Model calculations show that metal removal by sinking phytoplankton can account for only a small fraction of the annual loss.     

Associations de kystes de dinoflagellés des séries du Jurassique supérieur (Oxfordien–Tithonien) du Rif externe (Prérif interne et Mésorif,Maroc) et comparaisons régionales

A biostratigraphic study of dinoflagellate cysts of the Upper Jurassic series from the eastern External Rif Chain, has been achieved for the first time on four outcrop sections : the DM section (Douar Marticha), the TB section (the Tarhchenna “Sof”), the KSD section (the Kef Mallou “Sof”) and the Y section (Douar Lamriene) among which three sections (TB, KSD and Y) are well-dated by ammonites and calpionellids fauna. The DM and TB sections are complementary in terms of stratigraphy and correspond respectively to the upper part of the “Ferrysch” Formation, a thick shaly–silty and sandy sequence assigned to the Callovian-Oxfordian stages and to the El Gouzat limestones Formation (Kimmeridgian - Lower Tithonian age) and to the Tarhchenna marly limestones Formation (Upper Tithonian age) from the EL Gouzat area (Mesorif). The KSD and Y sections are also complementary and correspond to the Kimmeridgian-Lower Tithonian Msila limestones Formation and to the overlying marly limestones Massif Formation of Upper Tithonian age, outcropping in the Msila region (Internal Prerif). These four sections have shown many dinocysts rich levels, which had allowed characterizing the Middle? and Upper Oxfordian substages in the DM section. In the other sections, the dinoflagellate cyst assemblages are nearly similar to those of the Kimmeridgian–Tithonian of many sections from the Boreal, Sub-boreal and North tethyan realms, particularily from England, Russia and South-East France basin. The results of the present work confirm once again, the important value of dinoflagellate cysts, for age dating of ammonites-lacking Mesozoic sedimentary sequences and for biostratigraphic correlations.