Mechanisms of interaction of chromium with Aspergillus niger var tubingensis strain Ed8.

Experiments were conducted to determine the mechanisms of interaction with chromium of Aspergillus niger var tubingensis strain Ed8 in batch culture and in bioreactor experiments. Results obtained in this work showed that the interaction of A. niger var tubingensis Ed8 with Cr(VI) is based mainly in a reduction process and also, secondly, in a sorption process. Using electron microscopy techniques the ultrathin sections obtained from the mycelium biomass produced by the fungus in batch cultures showed the ability to incorporate Cr intracellulary, into low electron-dense inclusions, but not extracellularly. On the other hand, cultures without Cr(VI) of A. niger var tubingensis Ed8, grown in a bubble column bioreactor, reduced Cr(VI) immediately after repeated addition of this oxyanion; after six loads, 460 mg Cr(VI) was reduced to Cr(III) in 60 h, corresponding to a reduction rate of 2.62 mg Cr(VI)g(-1) dry biomass h(-1).

Changes in microvascular blood flow during coupled plasma filtration and adsorption.

A 51-year-old man with septic shock underwent three consecutive sessions of coupled plasma filtration-adsorption each lasting 12 hours. Sublingual microvascular perfusion was assessed using the orthogonal polarisation spectral imaging technique at three different times: immediate pre-coupled plasma filtration-adsorption phase, two hours following commencement and two hours after its termination. The video images of the sublingual microcirculation were analysed by an investigator blinded to the time of image acquisition. The De Backer's score was calculated. During the coupled plasma filtration-adsorption, the number of perfused vessels increased compared with the pre-coupled plasma filtration-adsorption period, but decreased again after its termination. It is arguable that the elimination of septic mediators during the procedure could account for the observed variations.

Increased PCP removal by Amylomyces rouxii transformants with heterologous Phanerochaete chrysosporium peroxidases supplementing their natural degradative pathway.

Fungal peroxidases and phenoloxidases are widely used in aromatic toxic compounds degradation. Peroxidases, such as lignin peroxidase and manganese peroxidase, as well as laccases are mainly produced by basidiomycetes and to a lower extent by other fungi, such as ascomycetes. Peroxidase-encoding genes have been described and homologous expression has been achieved in basidiomycetes. Heterologous expression has also been achieved in some non-producing peroxidase ascomycetes, like Penicillium and Aspergillus. In this work, heterologous expression of peroxidase-encoding genes, lignin peroxidase, and manganese peroxidase was achieved in a zygomycete producing only phenoloxidases (Amylomyces rouxii), aimed at coupling two different pathways used in nature for PCP removal in only one microbial strain. The ability of PCP removal was assayed with one of the obtained transformants, resulting in increased activity with respect to the ability of the parental strain cultured free of the inducer tyrosine (95% and 45%, respectively, of the initial PCP (12.5 mg L(-1)) in 120 h, or 100% and 49%, respectively, of the initial PCP after 144 h of liquid culture).

Influence of pH regulation and nutrient content on cephalosporin C production in solid-state fermentation by Acremonium chrysogenum C10.

AIMS: To investigate the effect of pH regulation and nutrient concentration on cephalosporin C (CPC) production in solid-state fermentation (SSF), using sugarcane bagasse as inert support, impregnated with liquid medium. METHODS AND RESULTS: Solid-state fermentation using different initial pH values, buffer and nutrient concentrations were performed. Results revealed pH as a key parameter in CPC SSF, as it hampered the antibiotic production not only above 7.8, but also under 6.4. Using initial pH lower than 6.8 and PB in the solid medium, it was possible to keep pH within the production range, increase the production period (from 1 to 3 days) and hence the CPC yield from 468 to 3200 microg gdm(-1) (g(-1) of dry matter). CONCLUSION: Parameters that help to keep pH in adequate values for CPC production in SSF, such as initial pH, buffering system and nutrient concentration, can greatly increase the production time and CPC yields in this fermentation technique. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first work on CPC production on impregnated support, and the only one revealing pH as a key parameter; it is also shown that high nutrient concentration can improve CPC yields in SSF as long as pH is kept under control.

A fungal phenoloxidase (tyrosinase) involved in pentachlorophenol degradation.

Amylomyces rouxii eliminated 85% of initial pentachlorophenol (PCP) at 12.5 mg l(-1) when grown with 0.1 g tyrosine l(-1), but only 55% without tyrosine. Addition of tyrosine in the culture medium increased the monophenolase activity by 1.8-fold. Tyrosinase is thus indicated to be the phenoloxidase involved in PCP degradation by A. rouxii .

Effect of some nutritional and environmental parameters on the production of diacetyl and on starch consumption by Pediococcus pentosaceus and Lactobacillus acidophilus in submerged cultures.

Three series of 5-day submerged cultures with Pediococcus pentosaceus MITJ-10 and Lactobacillus acidophilus Hansen 1748 were carried out in starch-based media, and the effect of cultural factors on the changes of starch, diacetyl and amylase activity determined. In axenic cultures, Ped. pentosaceus MITJ-10 produced more diacetyl (63.27 mg l(-1)) by adding glucose, yeast extract and CaCO3 (P < 0.01), at 28 degrees C (P < 0.05); but more starch was consumed (18.4 g l(-1)) in the absence of glucose (P < 0.01). Lact. acidophilus Hansen 1748 consumed more starch (26.56 g l(-1)) at 28 degrees C, with CaCO3, glucose (P < 0.01) and yeast extract (P < 0.05); however, the amylolytic activity (10077U l(-1)) was favoured at 35 degrees C (P < 0.01). Little starch was consumed in mixed cultures due to the low pH; nevertheless, diacetyl content rose to 135.76 mg l(-1) at 32 degrees C (P < 0.01). Therefore, both studied strains might be useful to produce aromatic extensors from starchy substrates. These natural aromatic extensors are of interest to the food industry.

Plasmapheresis in the critically ill patient.

Despite the wide number of diseases currently or previously treated with plasma exchange and plasmapheresis, the clinical effectiveness of these treatments has been established by large, controlled clinical trials only in few clinical conditions. The firmly accepted and the possible indications for these techniques in critically ill patients are reviewed and discussed, as well as their complications and possible side effects.

Fatal Streptococcus viridans descending mediastinitis: case report and review of the literature.

Mediastinitis is a life-threatening complication of cardiac, neck and oesophageal surgery. It has also been reported following upper digestive and respiratory procedures and as a consequence of oesophageal perforation following the ingestion of foreign bodies. Much more infrequently, mediastinitis can occur in association with oropharyngeal or cervical infections. We describe the case of a patient with fatal mediastinitis and septic shock. The onset of mediastinitis was preceded by a 2-day course of sore throat and other flu-like symptoms.

Traumatic blunt carotid injury: clinical experience and review of the literature.

To evaluate the symptoms, the associated lesions, the treatment and the outcome of patients with blunt carotid injury (BCI), we reviewed the records of all patients admitted to our intensive care unit with head trauma between May 1991 and May 1995. A patient's assessment included the commonly used severity scores and cranial computed tomography (CT). Other diagnostic investigations were performed according to the clinical setting. Four patients (2 males, 2 females, age 29 +/- 13 years) out of 145 were diagnosed to have BCI. At admission, the Glasgow Coma Scale (GCS) was > or = 12 in all patients, and was associated with hemiparesis in three of them; the fourth became paretic 48 hours later. No pathological elements were demonstrated at the initial CT scan, whilst subsequent examinations showed signs of ischaemia after a variable interval from admission. In every patient the radiologic investigations demonstrated a thrombotic obstruction of the internal carotid artery (ICA), associated with an intimal dissection in two cases. Three patients were discharged with only minor neurologic symptoms. The fourth patient was referred to our ICU after the development of a massive hemispheric infarction, and died 3 days after admission.

Drug-induced hyperthermia in a patient with persistent vegetative state. Case report and review of the literature.

The case of posttraumatic patient with persistent vegetative state and severe and prolonged hyperthermia (T = 39-40 degrees C for more than 20 days), in absence of infection, is described. Diffuse muscular rigidity, treated with L-dopa, slightly preceded the onset of hyperthermia, which was treated with several antipyretics, including phenotiazines. The withdrawal of these drugs and the administration of dantrolene and bromocriptine was followed by the restoration of the normal body temperature.

[Botulinum poisoning in adults: a case report and differential diagnosis]. / Intossicazione botulinica nell'adulto: descrizione di un caso e diagnosi differenziale.

The authors reports the case of a patient with quadriplegia associated with respiratory failure. A few days before, a paralysis of the oculomotor nerves appeared, which rapidly spreads in cranio-caudal fashion. The occurrence of a similar symptomatology in a patients' relative addressed the diagnosis toward a possible Clostridium botulinum intoxication. Other possible differential diagnoses are reviewed and discussed.

[Occurrence of acute refractory hypotension during laparoscopic cholecystectomy. Report of a case and review of the literature]. / Insorgenza di ipotensione acuta refrattaria durante colecistectomia laparoscopica. Descrizione di un caso e revisione della letteratura.

The authors report the case of a patient who developed irreversible cardiovascular collapse during a laparoscopic cholecystectomy. The abrupt onset of shock and the rapid deterioration of the hemodynamic conditions prevented a thorough diagnostic workup. Possible differential diagnoses of hypotension occurring during laparoscopic procedures are reviewed and discussed.