[Treatment of recurrent laryngeal nerve paralysis]. / Therapie von Rekurrensparesen.

Whereas static vocal fold medialization or lateralization are currently the standard procedures, new dynamic treatment methods such as reinnervation and laryngeal pacing focus on better toning and remobilization of the paralyzed vocal folds. End-to-end or jump anastomoses of the recurrent laryngeal nerve can preserve muscle mass and avoid atrophy, thus enabling subsequent dynamic therapeutic options. Prognostic evaluation and the time point of therapeutic intervention are important issues in the management of patients with recurrent laryngeal nerve paralysis. Irreversible interventions should be avoided at early time points or during childhood in order to allow for spontaneous remission and dynamic therapeutic options.

Multifocal primary amyloidosis of the airways: Case report and review of the literature.

Primary localized amyloidosis of the airways is an uncommon disorder characterized by amyloid deposits in the airway mucosa. In contrast to systemic amyloidosis other organs are not involved. Among the entities of airway amyloidosis, tracheobronchial amyloidosis is comparatively the most common subtype in the lower respiratory tract and laryngeal amyloidosis in the upper respiratory tract. The pathophysiology of localized airway amyloidosis is poorly understood. The clinical presentation is variable and often non-specific. No general consensus exists with regard to optimal treatment resulting in a variety of modalities used in clinical practice to manage this disorder. We report the case of a 50 year old woman with multifocal localized amyloidosis of the tracheobronchial tree and the upper airways. Tracheobronchial amyloidosis was treated with endoscopic debulking and external beam radiation, sinunasal amyloid deposits were surgically excised and are currently under surveillance. The importance of this extremely rare case lies in the multifocal presentation of an uncommon disorder requiring a multidisciplinary approach to offer optimal treatment including external beam radiation.

[Reinnervation and neurostimulation of the larynx]. / Reinnervation und Neurostimulation des Kehlkopfs.

Dynamic rehabilitation of vocal fold paralysis (VFP) should receive more emphasis in the future. In unilateral immobility with signs of atrophy and wide glottal gap, non-selective reinnervation with ansa cervicalis may become an alternative to augmentation and thyroplasty. For bilateral VFP progress has been made in the concepts of selective reinnervation and neurostimulation (pacing). These new therapies have the potential to restore near normal respiration-without compromising the voice quality-and may contribute to the development of larynx transplantation surgery.

Complex coacervate core micro-emulsions.

Complex coacervate core micelles form in aqueous solutions from poly(acrylic acid)-block-poly(acrylamide) (PAAxPAAmy, x and y denote degree of polymerization) and poly(N,N-dimethyl aminoethyl methacrylate) (PDMAEMA150) around the stoichiometric charge ratio of the two components. The hydrodynamic radius, Rh, can be increased by adding oppositely charged homopolyelectrolytes, PAA140 and PDMAEMA150, at the stoichiometric charge ratio. Mixing the components in NaNO3 gives particles in highly aggregated metastable states, whose Rh remain unchanged (less than 5% deviation) for at least 1 month. The Rh increases more strongly with increasing addition of oppositely charged homopolyelectrolytes than is predicted by a geometrical packing model, which relates surface and volume of the particles. Preparation in a phosphate buffer - known to weaken the electrostatic interactions between PAA and PDMAEMA - yields swollen particles called complex coacervate core micro-emulsions (C3-µEs) whose Rh increase is close to that predicted by the model. These are believed to be in the stable state (lowest free energy). A two-regime increase in Rh is observed, which is attributed to a transition from more star-like to crew-cut-like, as shown by self-consistent field calculations. Varying the length of the neutral and polyelectrolyte block in electrophoretic mobility measurements shows that for long neutral blocks (PAA26PAAm405 and PAA39PAAm381) the ζ-potential is nearly zero. For shorter neutral blocks the ζ-potential is around -10 mV. This shows that the C3-µEs have excess charge, which can be almost completely screened by long enough neutral blocks.

Softening of the stiffness of bottle-brush polymers by mutual interaction.

We study bottle-brush macromolecules in a good solvent by small-angle neutron scattering (SANS), static light scattering (SLS), and dynamic light scattering (DLS). These polymers consist of a linear backbone to which long side chains are chemically grafted. The backbone contains about 1600 monomer units (weight average) and every second monomer unit carries side chains with approximately 60 monomer units. The SLS and SANS data extrapolated to infinite dilution lead to the form factor of the polymer that can be described in terms of a wormlike chain with a contour length of 380 nm and a persistence length of 17.5 nm. An analysis of the DLS data confirms these model parameters. The scattering intensities taken at finite concentration can be modeled using the polymer reference interaction site model. It reveals a softening of the bottle-brush polymers caused by their mutual interaction. We demonstrate that the persistence decreases from 17.5 nm down to 5 nm upon increasing the concentration from dilute solution to the highest concentration (40.59 gl) under consideration. The observed softening of the chains is comparable to the theoretically predicted decrease of the electrostatic persistence length of linear polyelectrolyte chains at finite concentrations.

Microscopic mechanisms of electric-field-induced alignment of block copolymer microdomains.

We investigate the microscopic mechanisms responsible for microdomain alignment in block copolymer solutions exposed to an electric field. Using time-resolved synchrotron small-angle x-ray scattering, we reveal two distinct processes, i.e., grain boundary migration and rotation of entire grains, as the two dominant microscopic mechanisms. The former dominates in weakly segregating systems, while the latter is predominant in strongly segregated systems. The kinetics of the processes are followed as a function of polymer concentration and temperature and are correlated to the solution viscosity.

DFT study of the effect of sigma-ligands on the structure of ester enolates in THF, as models of the active center in the anionic polymerization of methyl methacrylate.

A Density Functional Theory (DFT) study was carried out on structures of the lithium ester enolate of methyl isobutyrate (MIB-Li) in THF solution, in the presence of TMEDA, dimethoxyethane (DME), crown ether 12-crown-4, and cryptand-2,1,1, as electron donor ligands (sigma-ligands). Both specific solvation with THF and/or ligand molecules and nonspecific solvation by the solvent continuum were taken into account. The possibility of ligand-separated ion pair formation was analyzed for each of the ligands, including THF alone. In most cases peripherally solvated dimers are the most stable species. Only in the presence of cryptand-2,1,1 was a ligand-separated triple ion pair, (MIB-Li-MIB)(-)(THF)(2),Li(2,1,1)(1)(+), shown to be comparable in stability to the THF-solvated dimer, (MIB-Li)(2)(THF)(4). These results are in agreement with experimental NMR data on the structure of MIB-Li in the presence of DME, 12-crown-4, and cryptand-2,1,1. An upfield shift of the (13)C NMR signal of the alpha-carbon of MIB-Li observed in the presence of cryptand-2,1,1, originally attributed to a ligand-separated monomer, MIB(-),Li(2,1,1)(+), was well reproduced by Hartree--Fock calculated NMR shifts for the predicted ligand-separated triple ion pair.

Adjuvant effect of Pluchea quitoc extract on the resistance of tumor-bearing mice by modulation of the host hematopoietic response.

Progressive tumor growth is regularly accompanied by changes in the cellular constituents of the immune system. Evidence suggests that soluble factors generated during tumor growth can affect the amount of granulocyte-macrophage progenitors. In vitro colony growth of progenitor cells may be an early indicator of the cellular changes associated with tumor growth. Pluchea quitoc has been previously found to modulate the hematopoietic response during bacterial infection. This study was designed to investigate the effects of P. quitoc on the growth and differentiation of bone marrow granulocyte-macrophage progenitor cells (CFU-GM) in Ehrlich ascites tumor-bearing mice. In contrast to the myelosuppression developed in the tumor-bearing animals, treatment with P. quitoc ethanolic extract (250, 500 or 1000 mg/kg) for 3 consecutive days after tumor challenge reversibly stimulated myelopoiesis, restoring the number of CFU-GM to normal. This same dose-schedule also increased colony formation in normal mice as compared to controls. In addi tion, P. quitoc significantly enhanced survival of tumor-bearing mice. These results suggest an immunoregulatory role for P. quitoc in counteracting the tumor-induced myelopoietic suppression as well as usefulness as adjuvant treatment of cancer.

Gastroprotective effect of aparisthman, a diterpene isolated from Aparisthmium cordatum, on experimental gastric ulcer models in rats and mice.

Aparisthmium cordatum (Juss.) Bail. (Euphorbiaceae), known in the State of Pará, Brazil as "ariquena queimosa", is a medium-sized tree which is native to the North Brazilian coastal region. Previous phytochemical studies of the bark of A. cordatum yielded a furan diterpenoid with a clerodane skeleton, called aparisthman. Recently, we reported the antiulcerogenic activity of trans-dehydrocrotonin (DHC), a furan diterpene isolated from Croton cajucara bark, in different ulcerogenic models in mice and rats. The aim of the present study was to assess the possible antiulcerogenic activity of aparisthman. When previously administered (p.o.) at the dose of 100 mg/kg(-1), aparisthman reduced significantly (p < 0.01) gastric injury induced by the indomethacin/bethanechol (71%), ethanol (71%), pylorus ligature, (59%) and hypothermic restraint-stress models (50%), in mice and rats. In the HCl/ethanol-induced gastric ulcer model in mice, at oral doses of 100 and 250 mg/kg(-1), aparisthman from A. cordatum reduced significantly (p < 0.001) the formation of gastric lesions by 59% and 66%, respectively, as compared with control. In the pylorus-ligature model, aparisthman (p.o.) decreased the volume of gastric juice as compared with control (p < 0.001). When aparisthman (100 mg/kg(-1)) was administered intraduodenally to mice, significant modifications were found, such as a decrease in gastric acidity as compared with control. In the animals pre-treated with aparisthman, free mucus production increased by 19% in the gastric mucosa (p < 0.05). The results suggest that aparisthman from A. cordatum presents a significant anti-ulcer effect when assessed in these induced ulcer models. Although the mechanism underlying this antiulcerogenic effect remains unknown, it seems to be related to an increase of the defensive mechanisms of the stomach such as prostaglandin synthesis and mucus production. The good yield of aparisthman obtained from A. cordatum, as well as its antiulcerogenic activity, suggest that this compound should be submitted to pharmacological research as a potential new antiulcerogenic drug.

Stimulatory action of Pluchea quitoc extract on the hematopoietic response during murine listeriosis.

The importance of both granulocytes and macrophages in the response to Listeria monocytogenes infection make this infection a suitable choice to investigate the effects of Pluchea quitoc on hematopoiesis. A significant depletion of bone marrow granulocyte-macrophage progenitor cells (CFU-GM) was observed at 48 and 72 h after intraperitoneal infection of mice with 1 x 10(4) L. monocytogenes. However, the treatment of infected animals with P. quitoc ethanolic extract (250, 500 or 1000 mg/kg) given orally for 3 consecutive days prior to infection produced a stimulatory effect on myelopoiesis, restoring the number of CFU-GM to normal. This same dose-schedule also increased colony formation in normal mice as compared to controls. In addition, P. quitoc significantly enhanced survival of infected mice. Thus, it is probable that the ability of P. quitoc to induce a higher reserve of granulocyte-macrophage precursors in the bone marrow is of major significance in determining early resistance to infection.

Flavonoids from Brosimum acutifolium.

4'-Hydroxy-7,8-[2-(2-hydroxyisopropyl)dihydrofuran]flavan and 4',7-dihydroxy-8-(3,3-dimethylallyl)flavan, together with 10 known plant constituents, were obtained from the trunk bark of Brosimum acutifolium. Their structures were elucidated by spectroscopic methods, including 2D NMR spectroscopic techniques.

Evaluation of the gastroprotective activity of cordatin, a diterpene isolated from Aparisthmium cordatum (Euphorbiaceae).

Aparisthmium cordatum (Juss.) BAIL. (Euphorbiaceae) is a medium sized tree native to the North Brazilian coastal region, which is known in the State of Pará as "ariquena queimosa." To our knowledge it has no popular use. Phytochemical studies of the benzene extract of the bark of A. cordatum yielded a furan diterpene with a clerodane skeleton, called cordatin. Recently, we reported the antiulcerogenic activity of trans-dehydrocrotonin (DHC), another furan diterpene isolated from Croton cajucara bark, in different ulcerogenic models in mice and rats. The aim of the present study was to assess the possible antiulcerogenic activity of cordatin, another compound of the clerodane diterpene group present in A. cordatum bark. When previously administered (p.o.) at the dose of 100 mg/kg, cordatin significantly reduced (p<0.01) gastric injury induced by the indomethacin/bethanechol (78%), ethanol (76%), and hypothermic restraint-stress models (66%) and by pylorus ligature (50%) in mice and rats. In the HCl/ethanol-induced gastric ulcer model in mice, at oral doses of 100 and 250 mg/kg, cordatin from A. cordatum significantly reduced (p<0.001) the formation of gastric lesions by 70% and 77%, respectively, when compared to the control. In the pylorus-ligature model, cordatin (p.o.) only decreased the volume of gastric juice compared to the control (p<0.001). When cordatin (100 mg/kg) was administered intraduodenally to mice, significant modifications were found, such as a decrease in gastric acidity compared to the control (p<0.05). In the animals pre-treated with cordatin, free mucus production was not altered when compared with the control group. The results suggest that cordatin from A. cordatum presents a significant anti-ulcer effect when assessed in these induced ulcer models. Although the mechanism underlying this antiulcerogenic effect remains unknown, it seems to be related to an anti-secretory property but the involvement of mucosal defensive mechanisms are not to be ignored. The good yield of cordatin obtained from A. cordatum, as well as its antiulcerogenic activity, suggest that this compound should be submitted to pharmacological research as a potential new antiulcerogenic drug.

A dimeric ArC2 compound from Peperomia pellucida.

Pellucidin A, a novel dimeric ArC2 compound, together with dill-apiol have been isolated from the aerial parts of Peperomia pellucida. The structure of pellucidin A was established by 1D and 2D NMR spectroscopy (1H-1H COSY; 1H-13C COSY; DEPT; NOESY and double irradiation) and other spectroscopic techniques. The biogenesis of pellucidin A is also briefly discussed.

Maturation induced internalization of beta 1-integrin by Xenopus oocytes and formation of the maternal integrin pool.

A pool of beta 1-integrin, ready to be inserted into the cleavage membranes, is present in the cytoplasm of the Xenopus egg, while its plasma membrane is devoid of this membrane protein (Gawantka et al., 1992). The underlying mechanisms that lead to this specific pattern of beta 1-integrin distribution in the egg have been investigated. beta 1-Integrin is present on the oocyte membrane throughout oogenesis. During maturation the oocyte membrane is cleared of beta 1-integrin via internalization of the protein by the oocyte. Synthesis of beta 1-integrin precursor is stimulated moderately in the maturing oocyte. At the same time processing of the precursor into the mature form of beta 1-integrin and its complexing with a putative alpha-chain is greatly accelerated. This way a maternal integrin pool accumulates in the mature oocyte. It is localized in conspicuous yolk free patches which contain large amounts of endoplasmic reticulum, Golgi complexes and smooth vesicles. We suggest that membrane vesicles harbouring the beta 1-integrin are generated in these cytoplasmic regions and that this store of vesicles provides the material source for the rapid membrane formation during cleavage.

U-cadherin in Xenopus oogenesis and oocyte maturation.

U-cadherin is a member of the cadherin family in Xenopus that participates in interblastomere adhesion in the early embryo from the first cleavage onwards. Though a maternal pool of U-cadherin is available in the egg, it is not present on the egg membrane (Angres et al., 1991. Development 111, 829-844). To assess the origin of this unexpected distribution in the egg, the accumulation and localization of the cadherin during oogenesis and oocyte maturation were investigated. We report here that U-cadherin is present in Xenopus oocytes throughout oogenesis. It is localized at the oocyte-follicle cell contacts suggesting that it functions in the adhesion of the two cell types. When oocytes mature and the contacts to the follicle cells break, U-cadherin disappears from the oocyte surface. Evidence for a translocation of U-cadherin from the membrane to the inside of the oocyte was obtained when the fate of membrane-bound U-cadherin, which was labelled on the surface of oocytes prior to maturation, was followed through maturation. The total U-cadherin content of the oocyte increases during maturation. Metabolic labelling experiments indicate that at maturation the translation of U-cadherin is elevated well above the level that one would expect from the general increase in protein synthesis is presumably the main source of the maternal pool of U-cadherin in the egg.

Differential expression of two cadherins in Xenopus laevis.

Using a cadherin fraction from Xenopus tissue culture cells as an immunogen, two monoclonal antibodies were obtained that allowed the characterization of two distinct cadherins in the Xenopus embryo. The two cadherins differ in molecular weight, in their time of appearance during development and in their spatial pattern of expression. One of the antigens was identified as E-cadherin. It appears in the embryonic ectoderm during gastrulation when epidermal differentiation commences and it disappears from the neural plate area upon neural induction. The second antigen could not be allocated to any of the known cadherin subtypes and was termed U-cadherin. It is present in the egg and becomes deposited in newly formed inner cell membranes during cleavage, the outer apical membranes of the embryo remaining devoid of the cadherin throughout development. U-cadherin is found on membranes of all cells up to the late neurula stages. A conspicuous polarized expression of the antigen on the membranes of individual inner cells suggests its participation in the segregation of cell layers and organ anlagen. These findings are discussed in the context of current hypotheses on the role of cadherins in establishing the spatial structure of the embryo.

El sulcus lunatus en el hombre. (Estudio morfologico). / Sulcus lunatus in human brain (Morphologic study)

Los autores presentan una investigacion casuistica sobre la incidencia y predominancia del sulcus lunatus en el cerebro del hombre. Tomando como punto de partida las incongruencias bibliograficas encontradas, se enfoca el trabajo desde un punto de vista estrictamente morfologico y macroscopico. La metodologia empleada consistio en observaciones directas del lobulo occipital, secciones en diferentes planos, mediciones de longitud y diagramacion de los casos examinados. A traves de los resultados obtenidos se arriba a conclusiones de alta significacion con respecto a incidencia, predominancia y bilateralidad. Se senala, ademas, que la diversidad del sulcus lunatus en cuanto a su conformacion anatomica ha obligado a dividir los casos positivos en un grupo con caracteres tipicos y otro con diferentes grados de atipia

[Radiologic aspects of temporal-bone fractures with facial paresis]. / Röntgenologische Aspekte der Felsenbeinfrakturen mit Fazialisparese

The value of the radiobiological diagnosis in establishing the localization of a facial palsy resulting from temporal bone fractures has been investigated in 49 cases. Radiological confirmation was found in 21 out of 37 cases of longitudinal fracture and in 11 out of 12 patients (90%) with a transverse fracture. The fracture line was seen by polytomography alone in 1 out of 21 (5%) longitudinal fractures and in 5 out of 11 (45%) transverse fractures. A precise readiological localization of the facial nerve lesion was only possible if the fracutre line was running across the long axis of the pyramid. The surgical revision of 37 patients has shown that the labyrinthine segment of the facial nerve was injured in 93% of longitudinal fractures and in 70% of the transverse fractures. Therefore, one should always be prepared to expose the labyringhine segment of the facial nerve when revising a facial nerve palsy due to a fracture of the temporal bone.