A pyrene-functionalized foldamer: structural impact and recognition properties supported by donor-acceptor interactions.

An electroactive and luminescent foldamer based on an oligopyridine biscarboxamide skeleton was synthesized and characterised. Its conformation in the solid state proved to be strongly affected by the peripheral pyrene units. The latter also endow the target derivative with recognition abilities toward electron-withdrawing molecules, which allow tuning of the spectroscopic properties of the foldamer.

Metal-driven self-assembly: the case of redox-active discrete architectures.

The metal-driven self-assembly strategy is well-established for the construction of discrete architectures featuring a cavity. The resulting molecular rings and cages are potentially useful as hosts for complementary guests. Recent years have seen growing interest in the introduction of given functionalities, including redox properties which, among others, allow modulating the ionic charge of the cavity. Depending on which subunit is electroactive, various situations can be encountered, with a global redox activity which is ligand- and/or metal-centered and which involves or not electronic interactions between the constituting units. In this feature article, we propose to survey those different situations by exploring some recent examples of the growing family of redox-active self-assembled rings and cages.

Intraperitoneal free cancer cells in non-gynaecological adenocarcinomas: a reproducibility study.

OBJECTIVE: In recent years, therapeutic approaches including cytoreductive surgery followed by intraperitoneal chemotherapy have proven effective in peritoneal carcinomatosis of colorectal origin. If cytology is to be used to include patients in aggressive treatment regimens, it is necessary to evaluate its performance, particularly in terms of specificity. The aim of this study was to assess interobserver agreement for the detection of intraperitoneal free cancer cells (IFCCs) in patients with non-gynaecological adenocarcinomas. METHODS: Over a 5-year period, 1223 patients were recruited in 19 French surgery departments. Peritoneal samples were examined in 14 dispersed pathology laboratories. Giemsa-stained slides were sent to a control reader blind to the previous diagnosis. Discordant cases, concordant positive results and a random selection of negative concordant cases were reviewed by a panel of seven cytopathologists. The 'final diagnosis' was that of the consensus meetings but took into account locally-processed slides. RESULTS: Gathering dubious cases with negative results, a 95.6% concordance was achieved between local readers and the control reader. IFCCs were ascertained by the panel in 85 cases (7.0%). Eight of 873 colorectal cancers cases viewed locally were falsely positive (0.9%). Radiotherapy and neoadjuvant therapy had no impact on the false-positive rate as assessed by final validation by the panel (P > 0.05). Samples initially considered as dubious were reclassified as negative by the panel in 24 of 25 cases (96.0%). CONCLUSIONS: The panel consensus allowed reclassification of most dubious/equivocal peritoneal cytology cases, whereas clearcut distinction between benign and malignant cases was correctly achieved in almost all cases.

A study by spectroelectrochemical FTIR and density functional theory calculations of the reversible complexing ability of an electroactive tetrathiafulvalene crown.

We report on the study of the electrochemically targeted complexation/expulsion of a metal cation (Ba2+) by a crown ether tetra(thiomethyl)tetrathiafulvalene derivative (crown-TTM-TTF). Real time, in situ FTIR spectroelectrochemistry was used to obtain spectroscopic evidence of this electrochemically triggered phenomenon. Density functional theory calculations allowed the spectral information collected to be assigned. Both experimental and theoretical results clearly show that neutral crown-TTM-TTF complexes well Ba2+. Complexation is evidenced by a significant downshift of the frequency corresponding to the asymmetric stretching of the C-O-C ether groups. Concerning the cation crown-TTM-TTF, the spectroscopic signal of the complex form was difficult to identify, first because of the rather low value of the complexation constant and second because the vibration modes involving the oxygen atoms (which are the most affected by the complexation) were found by calculation to occur in the lower spectral region (<1000 cm(-1)), which is not accessible in our experimental conditions. In the case of the dication crown-TTM-TTF, it is now clear that the complex form does not exist, which means that the electrochemical formation of the dication necessarily involves the expulsion of the barium ion.

Tetrathiafulvalene crowns: redox-switchable ligands.

A series of redox-responsive ligands that associate the electroactive tetrathiafulvalene core with polyether subunits of various lengths has been synthesized. X-ray structures are provided for each of the free ligands. The requisite structural criteria for reaching switchable ligands are satisfied for the largest macrocycles, that is, planarity of the 1,1',3,3'-tetrathiafulvalene (TTF) pi system and correctly oriented coordinating atoms. The ability of these ligands to recognize various metal cations as a function of the cavity size has been investigated by various techniques (LSIMS, 1H NMR, and UV/Vis spectroscopy, cyclic voltammetry). These systems exhibit an unprecedented high coordination ability among TTF crown ethers. Their switchable ligating properties have been confirmed by cyclic voltammetry, and metal-cation complexation has been illustrated by X-ray structures of three of the corresponding metal complexes (Pb2+, Sr2+, and Ba2+). Solid-state structures of these complexes display original packing modes with channel-like arrangements.

Giant foot schwannoma.

Schwannoma of the foot is rare; only 12 cases have been reported. A schwannoma is a benign neurogenic tumour derived from Schwann cells. The diagnosis is often delayed because the symptoms are mainly those of compression disorders. We describe a 7cm schwannoma of the heel in a 30-year-old man. Ten years earlier a schwannoma was removed from the same site. The recurrent lesion was widely excised and a medial plantar flap was used to repair the heel.

pi conjugation across the tetrathiafulvalene core: synthesis of extended tetrathiafulvalene derivatives and theoretical analysis of their unusual electrochemical properties

A series of extended tetrathiafulvalene (TTF) derivatives bearing one or two 1,4-dithiafulven-6-yl substitutents has been prepared. The new compounds present remarkable electrochemical singularities compared with other TTF derivatives, which are strongly affected by the nature of the substitution on the lateral heterocycle(s). This unusual electrochemical behaviour follows a square-scheme sequence and is attributed to structural changes upon oxidation of the pi-donating molecules. Digital simulations of the electrochemical data have been used to reach the values of the kinetic and thermodynamic constants involved in the square scheme. Theoretical calculations establish an important contribution of a highly delocalised resonant form involving a tetravalent sulphur in oxidised species, which could justify the occurrence of an electrochemical behaviour distinct from that of TTF. Finally, third-order susceptibilities chi 3 of two of these systems, for which electron-donating and electron-withdrawing substituents coexist and are conjugated through the TTF pi system, are given.

[Transthoracic aspiration. Evaluation of cytologic and histologic diagnosis in a pulmonary nodule by retrospective comparison of 2 series of 267 cytoaspirations and 292 coaxial needle aspirations]. / La ponction trans-thoracique. Evaluation du diagnostic cytologique et histologique d'un nodule pulmonaire par comparaison rétrospective de 2 séries de 267 cytoponctions et de 292 ponctions à l'aiguille coaxiale.

Percutaneous fine-needle aspiration is a well established method for the diagnosis of peripheral lung lesion. In order to compare different methods of aspiration, we analyze retrospectively two different series: 267 fine needle aspirations (FNA) compared with the histological diagnosis on surgical specimens and 292 lung biopsies using a coaxial technique with comparison between cytological diagnosis--smears and imprints--and histological diagnosis simultaneously obtained on the same specimen. The sensitivity (91%), the specificity (90%) and the overall typing accuracy related to the histological types obtained by FNAB are equivalent to those of the literature. The low rate of pneumothorax in the series (6%) is related to the use of immediate interpretation of the specimen. Automated biopsy with a coaxial cutting needle provide cytological specimens--smears and imprint--with a high rate of sensibility (95.3%) and of sensibility (98%). The overall sensitivity of the cytological methods alone is better than biopsy (95.3% vs. 92.9%), but the typing accuracy is not as good as biopsy alone (98% vs. 100%). False-positive and false-negative diagnoses are the same in both series. In conclusion the percutaneous aspiration method choose to establish a morphological diagnosis in lung lesion depends now on the habits of the radiologist and the pathologist.

Cytological aspiration of intraocular retinoblastoma in an 11-year-old boy.

Only a few cases of retinoblastomas in older children have been reported and the clinical diagnosis may be difficult. In case, fine-needle aspiration from an atypical retinal mass of an 11-yr-old boy was performed. The vitreous fluid was stained with Diff-Quik for an immediate cytological examination and the diagnosis of retinoblastoma was suggested. The rest of the specimen was separated into two parts. One was stained with May-Grünwald-Giemsa and the other was centrifuged, embedded in paraffin, and finally stained with hematoxylin-eosin-safran. The undifferentiated blue cells were associated with abundant necrotic debris and portions of capillaries with perivascular tumor cells around. The cytoplasm of the tumor cells was strongly stained with neuron-specific enolase antibody. The diagnosis of retinoblastoma was confirmed. The specimen of enucleation confirmed the diagnosis. In conclusion, cytological aspiration can categorically diagnose suspected intraocular tumors of older children in whom clinical and noninvasive investigations have failed to establish the diagnosis.

Electronic and nuclear contributions to the third-order nonlinear optical susceptibilities of new p-N, N'-dimethylaniline tetrathiafulvalene derivatives.

We report large third-order nonlinear optical susceptibilities (?3?)(ijkl) of new tetrathiafulvalene derivatives, using the degenerate four-wave mixing (DFWM) method. To understand the physical nature of the optical nonlinearities, we separate their electronic and nuclear contributions. The electronic contribution to the third-order nonlinear optical susceptibilities of the molecules turns out to be dominant. From DFWM measurements we also deduce the values of the second-order hyperpolarizabilities gamma, which are ~10(5) greater than the gamma value of CS(2).

Molecular cloning and polymorphism of the human immune deficiency virus type 2.

We recently reported the isolation of a novel retrovirus, the human immune deficiency virus type 2 (HIV-2, previously named LAV-2), from patients with acquired immune deficiency syndrome (AIDS) originating from West Africa. This virus is related to HIV-1, the causative agent of the AIDS epidemic now spreading in Central and East Africa, as well as the USA and Europe (see ref. 3 for review) both by its morphology and by its tropism and in vitro cytopathic effect on CD4 (T4) positive cell lines and lymphocytes. But preliminary hybridization experiments indicated that there are substantiated differences between the sequences of the two genomes. Furthermore, the proteins of HIV-1 and HIV-2 have different sizes and their serological cross-reactivity is restricted to the major core protein, as the envelope glycoproteins of HIV-2 are not immunoprecipitated by HIV-1-positive sera. We now report the molecular cloning of the complete 9.5-kilobase (kb) genome of HIV-2, the observation of restriction site polymorphism between different isolates, and a preliminary analysis of the relationship of HIV-2 with other human and simian retroviruses.

[Contribution of thoracoscopic brushing to the diagnosis of pleural diseases]. / Apport du brossage par thoracoscopie au diagnostic des affections pleurales.

Pleural brushing can be performed under thoracoscopic examination. The combined use of all three methods of diagnosis (macroscopy, biopsy, cytology) achieved optimal diagnostic results. From September 1980 to October 1981 we have performed 150 thoracoscopies for pleural effusions, while the results of conventional pleural cytology and biopsy were negative. In 108 cases pleural brushing and biopsy were both performed. The diagnosis was in 37 cases non malignant diseases states associated with effusions and in 71 cases tumoral effusions. Among the 37 cases of non malignant diseases states associated with effusions were: 6 mechanical effusions, 27 inflammatory processes, 4 infectious processes. Among the 71 cases of tumoral effusions were 3 benign pleural lipomas, 50 metastatic carcinomas, 18 carcinomatous mesotheliomas. We studied the diagnostic accuracy of pleural brushing: in non malignant diseases, pleural brushing show the non tumoral features of the process, in metastatic tumours, biopsy was positive in 80% of the cases; pleural brushing in 78% of cases; taken together they allowed the diagnosis in 86% of the cases, in carcinomatous mesotheliomas biopsy was positive in 82,3%, pleural brushing in 78%; taken together they allowed the diagnosis in 89% of the cases. Pleural brushing allows a rapid cytological diagnosis, enhances the histological results and may also be used to get cellular material in areas dangerous to biopsy.

[Value of transparietal lung biopsy in the cytological diagnosis of bronchiolo-alveolar carcinomas of the lung. Apropos of 3 cases]. / Apport de la ponction pulmonaire transpariétale au diagnostic cytologique des carcinomes bronchiolo-alvéolaires du poumon. A propos de 3 cas.

Bronchiolo-alveolar carcinoma is a rare primary lung tumour, which is difficult to diagnose by cytological techniques. This peripheral tumour, which develops on pre-existing alveolar walls, is not visible on bronchial endoscopy and brushing is often negative. The cellular material derived from aspiration or expectoration is characterised by numerous papillae, without any cytonuclear criteria of malignancy. The differential diagnosis is very difficult with reactive papillary hyperplasia and various forms of chronic bronchial inflammation. Transparietal aspiration lung biopsy facilitates the diagnosis of glandular carcinoma: the material examined corresponds to pathological tissue, as the biopsy is performed under image intensifier control. An inflammatory lesion is excluded by the rich cellularity and by the presence of architectural features of malignancy: cohesive and three-dimensional clumps of papillary tumour cells. The early cytological diagnosis of bronchiolo-alveolar and primary bronchiolar carcinomas of the lung by transparietal aspiration biopsy can allow the surgical cure of certain localised forms.

[Thoracoscopy with pleural brushing. A new diagnostic method for pleural diseases]. / La thoracoscopie avec brossage pleural. Un nouveau mode diagnostique des affections de la plèvre.

Pleural brushing can be performed under thoracoscopic examination. The combined use of all three methods of diagnosis (macroscopy, biopsy, cytology) achieved optimal diagnostic results. From September 1980 to October 1981 we have performed 150 thoracoscopies for pleural effusions, while the results of conventional pleural cytology and biopsy were negative. In 108 cases pleural brushing and biopsy were both performed. The diagnosis was in 37 cases non malignant disease states associated with effusions and in 71 cases tumoural effusions. Among the 37 cases of non malignant diseases states associated with effusions were 6 mechanical effusions, 27 inflammatory processes, 4 infectious processes. Among the 71 cases of tumoural effusions were 3 benign pleural lipomas, 50 metastatic carcinomas, 18 carcinomatous mesotheliomas. We studied the diagnostic accuracy of pleural brushing: in non malignant diseases pleural brushing show the non tumoural features of the process, in metastatic tumours biopsy was positive in 80% of the cases; pleural brushing in 78% of cases; taken together they allowed the diagnosis in 86% of the cases, in carcinomatous mesotheliomas biopsy was positive in 82.3%, pleural brushing in 78%; taken together they allowed the diagnosis in 89% of the cases. Pleural brushing allows a rapid cytological diagnosis, enhances the histological results and may be used to get cellular material in areas dangerous to biopsy.