Reduction of vanadate to vanadyl by a strain of Saccharomyces cerevisiae

Three strains of Saccharomyces cerevisiae, SC-1, DBVPG 6173 and DBVPG 6037, were studied for vanadate resistance in complex Sabouraud medium since they did not thrive in different minimal media (yeast nitrogen base with and without amino acids). The strain SC-1 was resistant up to 16 mm of vanadate, whereas the strains DBVPG 6173 and DBVPG 6037 were inhibited by 8 mm and 4 mm vanadate, respectively. The vanadate resistance in strain SC-1 was constitutive and due to the reduction of this oxyanion to vanadyl, which was detected by EPR spectroscopy and visible spectroscopy. The transformation of vanadate to vanadyl took place during the exponential growth phase; 10 mm of vanadate was reduced to vanadyl outside the cells since the oxyanion was not detected in the cell biomass and only a negligible concentration of vanadyl (25 nmoles mg cells dry weight) was found in the biomass. The other two vanadate-sensitive yeast strains only accumulated vanadate and did not reduce the oxyanion to vanadyl.     

Evaluation of the voice function after the supraglottis subtotal laryngectomy

Voice quality was analysed in 39 patients with the larynx carcinoma after the supraglottis subtotal laryngectomy. Voice pattern was analysed with the use of subjective and objective spectrography before and after the surgery. A deteriorated voice quality was found after the surgery. The spectrographic examination revealed decreased frequency levels of the formants F3 and F4 and the presence of a noise component generated in the glottis area.     

Mercury-resistant bacterial strains Pseudomonas and Psychrobacter spp. isolated from sediments of Orbetello Lagoon (Italy) and their possible use in bioremediation processes

This study was aimed to isolate Hg-resistant bacteria from contaminated sediments of the Orbetello Lagoon in Italy and to assess their possible use as biofilms in bioremediation processes. Enrichment cultures prepared from contaminated sediments in the presence of 0.05 mM of mercury and under aerobic conditions allowed the isolation of five heterotrophic bacterial strains. 16S rDNA gene sequencing assigned the isolated strains to the genera Pseudomonas and Psychrobacter. For the first time mercury-resistant bacterial strains belonging to the genus Psychrobacter were evidenced. Minimum inhibitory concentrations in the presence of HgCl₂ and of CH₃HgCl showed high levels of resistance. EC50 values for the isolated bacterial strains in the presence of HgCl₂ and of CH₃HgCl confirmed the adaptation to the metal. Hg-resistant strains ORHg1, ORHg4 and ORHg5 showed the capacity to volatilize inorganic and organic mercury to elemental mercury, and formed biofilms on pumice particles, and were shown to play a role in the removal of mercury from sediment leachates. This study reports isolation and characterization of new Hg-resistant bacterial strains and provides novel insight into their possible use in bioremediation processes of mercury polluted sediments.     

Validation of thermal composting process using olive mill solid waste for industrial scale cultivation of Agaricus bisporus

The production of a substrate containing destoned olive mill solid waste for the cultivation of Agaricus bisporus (Lange) Imbach on an industrial scale was studied. A standard mushroom compost (C) mainly made from straw and poultry manure was compared with the experimental compost (EC) containing the same ingredients as (C) but with added olive mill solid waste (10.6% w/w). Microbial indicators such as counts of heterotrophic microbes and actinomycetes were higher in EC than in C. In addition, compost selectivity as indicated by higher mushroom yield and biological efficiency of EC was higher than that of C. Market quality of the mushrooms produced in both C and EC were comparable. These findings support our work that olive mill solid waste can be used safely in thermal composting process to produce a selective substrate for industrial-scale cultivation of A. bisporus. This study also demonstrates an environmentally sustainable system to manage solid waste from olive oil extraction processes thus overcoming environmental pollution brought about by irrational disposal of the waste on farm lands.     

Sclerosing variant of PEComa: report of a case and review of the literature

Tumours of perivascular epithelioid cells (PEComas) are a heterogeneous group of uncommon mesenchymal neoplasms which exhibit a peculiar immunohistochemical co-expression of muscle and melanocytic markers. PEComas occur at various visceral and soft tissue sites, generally with a benign clinical course. Nevertheless, there has been evidence of cases having an unfavourable outcome, thus prompting investigation of pathological criteria for malignancy. A sclerosing variant of PEComa, more frequently encountered in the retroperitoneum of middle-aged women, has been reported. Prognosis has generally been regarded as favourable and complete surgical excision appears to be adequate treatment. To the best of our knowledge, only two cases of sclerosing PEComa displayed high-grade malignant morphology and were associated with adverse outcome. An additional case of retroperitoneal sclerosing PEComa with a two-year follow-up and indolent behaviour is herein described. Light and electron microscopy were performed, along with immunohistochemical analysis. Further studies are needed to clarify the histogenesis and to predict the biological behaviour of this uncommon entity.     

Hypersensitivity of lung vessels to catecholamines in systemic hypertension.

Among patients with primary systemic hypertension pressure and arteriolar resistance in the pulmonary circulation exceed normal values and are hyper-reactive to sympathetic stimulation. A study was therefore carried out in 16 patients with uncomplicated essential hypertension and nine healthy subjects to compare the pulmonary vascular reactivity to exogenous catecholamines. In the normotensive group the dose response relation to adrenaline (microgram: dyn) was 1 = -4, 2 = -9, 3 = -9, and 4 = -10 and to noradrenaline 2 = +3, 4 = /8, 6 = +4, and 8 = +3. The relations in the hypertensive subjects were 1 = +18, 2 = +42, 3 = +59, and 4 = +77 and 2 = +39, 4 = +54, 6 = +76, and 8 = +100, respectively. Group differences were highly significant. Cardiac output (blood flow through the lungs) was raised by adrenaline and reduced by noradrenaline. In either case the driving pressure across the lungs was significantly augmented in the hypertensive patients but not in the normotensive group. Both catecholamines had a vasoconstrictor effect on the pulmonary circulation as a result of vascular over-reactivity. The opposite changes in resistance between normal and hypertensive subjects produced by adrenaline suggest that a constrictor vascular hypersensitivity occurs in the pulmonary circulation with the development of systemic high blood pressure.     

Performance of olive mill solid waste as a constituent of the substrate in commercial cultivation of Agaricus bisporus

The feasibility of using olive mill waste (OMW) as an ingredient in the substrate used for cultivation of Agaricus bisporus (Lange) Sing. was studied in a large-scale cultivation trial, concerning 2500 m² of mushroom growing area, at a specialized mushroom farm. Standard commercial cultivation technique involving compost preparation, spawning, casing and harvesting was used. The performance indicators such as mushroom yield, biological efficiency, market quality as well as horticultural value of the spent compost showed that the compost prepared with OMW was superior to the control compost in all the categories. The OMW-amended substrate supported higher populations of beneficial microorganisms especially, actinomycetes which enabled the breakdown of the compost ingredients. It is suggested that OMW is a suitable ingredient for the preparation of mushroom substrate. We have demonstrated that conversion of OMW (a liability) into value-added mushroom substrate (an asset) is an effective waste management tool in oleaculture.     

Tolerance to mercury chloride in Scenedesmus strains

Mercury chloride toxicity was investigated in two strains of Chlorella and in a strain of Scenedesmus isolated from polluted areas in Tuscany (Italy). No Hg resistance was found in the autotrophic microorganisms isolated, but Scenedesmus sp. strain AR-2489, isolated from the Arno river, was able to grow at concentrations of up to 5 mg ml1 of Hg. This concentration was twice that which inhibited growth of the two Chlorella strains and Scenedesmus acutus 8M, the reference strain from a culture collection. Photosynthesizing cells of Scenedesmus sp. AR-2489 showed reduced Hg uptake, with the highest percentage of Hg removal from the medium. Loss of Hg was not due to Hg(0) volatilization, as shown by a comparison test with the broad-spectrum Hg-resistant Pseudomonas putida FB1. The metabolic differences between Scenedesmus sp. strain AR-2489 and Siacatus strain 8M were: (1) higher growth rate (doubling time of 6.0h versus 10.6 h); (2) higher O2 production rate (maximum 2 mmol h mg dry weight); and (3) higher intracellular pH during growth. The latter was imaged with a green fluorescence molecular probe (BCEFC–AM) and observed by scanning confocal laser microscopy (SCLM). The distribution of red-autofluorescence chlorophyll-a showed that strain AR-2489 had a rougher and hence more extended specific chloroplast surface than strain 8M. Hg tolerance in strain AR-2489 was related to the rapid increase in dissolved O in the medium and in intracellular pH; this caused a loss of soluble mercury transformed to insoluble mercury hydroxide, which is thermodynamically more stable at alkaline pH in highly oxygenated systems.     

The evaluation of human papillomavirus and p53 gene mutation in benign and malignant conjunctiva and eyelid lesions

Papillomas and squamous cell carcinomas are the most common conjunctival and eyelid lesions. The etiology is still unclear and recently human papillomavirus infection and p53 gene mutation have been taken into consideration. The aim of our study was the evaluation of HPV DNApresence and p53 gene mutation in 45 benign and 38 malignant squamous lesions of the conjunctiva and eyelid. For HPV detection PCR-RFLP and immunohistochemical reaction were used; for p53 gene mutation PCR-SSCP was used. Only 8.8% papillomas, 9.1% squamous cell cancers and 3.7% basal cell cancers (using PCR-RFLP method) and 26.6% papillomas, 7.4% squamous cell cancers and 9.1% basal cell cancers (using immunohisto-chemical reaction) were HPV positive. p53 gene mutation was evaluated in 24.4% papillomas, 54.5% squamous cell cancers and 22.2% basal cell cancers; most commonly in 6 and 7 exon. Human papillomavirus infection, opposite to p53 gene mutation, is not a significant etiological factor of the benign and malignant conjunctival and eyelid lesions development.