Strategies and Controversies in the Treatment With Carbon Dioxide Laser of Laryngeal Hemangioma: A Case Series and Review of the Literature

Introduction: The hemangioma is the most common vascular tumor, involving the head and neck in 60% of cases. It is rare in the larynx. In children, hemangiomas are more frequent on the subglottis, whereas in adults the most common site is the supraglottis. Laryngeal hemangioma with cavernous features isolated to the free edge of the vocal fold is a very rare clinical finding. We present 2 cases of glottic hemangioma. Both patients reported severe hoarseness. Cases: In the first patient, an extensive blue-purple mass was seen on the right vocal cord. The patient was posted for microlaryngeal surgery with carbon dioxide (CO2) laser. Second patient had a large, smooth, flesh-colored polypoid mass emanating from the left vocal cord. The patient was posted for microlaryngeal surgery. After 2 months, both patients showed a considerable voice improvement. Discussion: Vocal cord hemangiomas are very rare, and they usually cause problem in the voice of the patient. A vascular lesion that may mimic a hemangioma may sometimes result from an organizing hematoma following a hemorrhage on the vocal cords due to voice abuse. Laryngeal hemangiomas also need to be distinguished pathologically from polypoidal vascular granulation tissue that may be produced by laryngeal biopsy, intubation, or trauma. Indirect endoscopy is enough to diagnosis. No active treatment is advised for adult laryngeal hemangiomas unless the lesions are symptomatic or show a tendency to involve other parts. There is no uniformly accepted treatment of head and neck hemangiomas. Surgical excision with laser CO2 microlaryngoscopic techniques gives satisfactory results

Effect of nitrate on enzymes of N-metabolism in durum wheat seedlings

XXXIX Congresso Annuale della Società Italiana di Fisiologia Vegetale (p. 84). SIFV- Bologna, 18 - 20 Settembre 2000

Coumarin inhibits the growth of carrot (Daucus carota L. cv. Saint Valery) cells in suspension culture

We used a carrot (Daucus carota L. cv. Saint Valery) cell suspension culture as a simplified model system to study the effects of the allelochemical compound coumarin (1,2 benzopyrone) on cell growth and utilisation of exogenous nitrate, ammonium and carbohydrates. Exposure to micromolar levels of coumarin caused severe inhibition of cell growth starting from the second day of culture onwards. At the same time, the presence of 50μmol/L coumarin caused accumulation of free amino acids and of ammonium in the cultured cells, and stimulated their glutamine synthetase, glutamate dehydrogenase, glucose-6-phosphate dehydrogenase and phosphoenolpyruvate carboxylase activities. Malate dehydrogenase, on the other hand, was inhibited under the same conditions. These effects were interpreted in terms of the stimulation of protein catabolism and/or interference with protein biosynthesis induced by coumarin. This could have led to a series of compensatory changes in the activities of enzymes linking nitrogen and carbon metabolism. Because coumarin seemed to abolish the exponential phase and to accelerate the onset of the stationary phase of cell growth, we hypothesise that such allelochemical compounds may act in nature as an inhibitor of the cell cycle and/or as a senescence-promoting substance

Genetic full waveform inversion to characterise fractures

Understanding the physical properties of fractures, location, orientation, and geometry is of primary importance in the comprehension of geo-resources and geo-hazards. In doing so seismic waves can be an effective tool for non-invasive investigation of fracture parameters. We have developed a novel stochastic Full Waveform Fracture Inversion employing Genetic Algorithms (GA-FWFI) to quantify mechanical properties of fractures (fracture-specific stiffnesses) in a synthetic sample. We focus on the inversion of transmitted waves, simulating ultrasonic laboratory data, on a specimen containing 6 horizontal fractures orthogonal to the wave propagation. The inversion results show a good convergence to the solution which best fits the observed data within the maximum number of generations and number of models set

SEA URCHIN DNA METHYL-TRANSFERASES.

DNA methyltransferase activities have been partially purified from unfertilized eggs and blastula nuclei of sea urchin embryos. Comparative studies, using different DNAs as substrates, show that the two preparations are most active on hemimethylated and singlestrand DNA, but they methylate, though at a lower rate, also on double-strand DNA. The two activities show distinctive efficiencies in methylating plasmid DNAs and marked differences in the rate of methyl transfer to DNAs in different structural states: linear, relaxed, or supercoiled. The ratio of the apparent specific activity of the two preparations depends on the particular DNA used as substrate and its structure. Methylation analysis of the restriction fragments of methylated plasmid DNAs shows a linear correlation between introduced methyl groups and the percent of CpG of each particular fragment, indicating that methylation is substantially random and sequence is less relevant than conformation in determining enzyme efficiency. The data do not permit us to decide if the two activities are different enzymes or the same enzyme with different modulating factors. © 1989 Humana Press Inc