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Laura Farina

Publications and source records attributed to Laura Farina.

8 recordsLinked to original sources
PubMed2005

De novo synthesis of monoterpenes by Saccharomyces cerevisiae wine yeasts.

This paper reports the production of monoterpenes, which elicit a floral aroma in wine, by strains of the yeast Saccharomyces cerevisiae. Terpenes, which are typical components of the essential oils of flowers and fruits, are also present as free and glycosylated conjugates amongst the secondary metabolites of certain wine grape varieties of Vitis vinifera. Hence, when these compounds are present in wine they are considered to originate from grape and not fermentation. However, the biosynthesis of monoterpenes by S. cerevisiae in the absence of grape derived precursors is shown here to be of de novo origin in wine yeast strains. Higher concentration of assimilable nitrogen increased accumulation of linalool and citronellol. Microaerobic compared with anaerobic conditions favored terpene accumulation in the ferment. The amount of linalool produced by some strains of S. cerevisiae could be of sensory importance in wine production. These unexpected results are discussed in relation to the known sterol biosynthetic pathway and to an alternative pathway for terpene biosynthesis not previously described in yeast.

Acyclic Monoterpenes↗
PubMed2005

Wallerian degeneration of the pontocerebellar fibers.

Two cases of pontine infarct with Wallerian degeneration (WD) of the pontocerebellar fibers are described. WD of pontocerebellar fibers, seen bilaterally along the transverse pontine fibers, is more visible in the middle cerebellar peduncles and extends into the white matter of the cerebellar hemispheres. Understanding the anatomy of the white matter and the temporal evolution of this degeneration is essential in identifying WD.

Aged↗
PubMed2004

Operative findings and outcomes of microvascular decompression for trigeminal neuralgia in 35 patients affected by multiple sclerosis.

OBJECTIVE: The concept of vascular compression of the trigeminal root as the main etiological factor in idiopathic trigeminal neuralgia has achieved widespread acceptance, and microvascular decompression (MVD) is a well-established surgical procedure for its treatment. Multiple sclerosis (MS) has long been considered to be an absolute contraindication to MVD because of the supposed exclusive causative role of a demyelinating lesion affecting the trigeminal root entry zone. Magnetic resonance imaging preoperative identification of suspicious vessels along the cisternal course of the trigeminal nerve in MS patients raises the question of a possible causative role of vascular compression in MS patients. METHODS: We describe magnetic resonance imaging findings, surgical findings, and outcomes in 35 MS patients who underwent MVD for medically intractable trigeminal neuralgia. Results were assessed by clinical follow-up and periodic phone surveys. The mean follow-up was 44 months (range, 6-108 mo). RESULTS: Magnetic resonance imaging revealed the presence of demyelinating lesions affecting the brainstem trigeminal pathways of the painful side in 26 (74%) of 35 patients. During surgery, severe neurovascular compression at the trigeminal root entry zone was found in 16 (46%) of 35 patients. The long-term outcome was excellent in 39%, good in 14%, fair in 8%, and poor in 39% of patients. No statistically significant prognostic factor predicting good outcome could be found. There was no mortality, with a 2.5% long-term morbidity rate (facial nerve palsy in one patient). CONCLUSION: Results of MVD in trigeminal neuralgia MS patients are much less satisfactory than in the idiopathic group, indicating that central mechanisms play a major role in pain genesis.

Adult↗
PubMed2002

Tetracyclines affect prion infectivity.

Prion diseases are transmissible neurodegenerative disorders of humans and animals for which no effective treatment is available. Conformationally altered, protease-resistant forms of the prion protein (PrP) termed PrP(Sc) are critical for disease transmissibility and pathogenesis, thus representing a primary target for therapeutic strategies. Based on previous findings that tetracyclines revert abnormal physicochemical properties and abolish neurotoxicity of PrP peptides in vitro, we tested the ability of these compounds to interact with PrP(Sc) from patients with the new variant of Creutzfeldt-Jakob disease (vCJD) and cattle with bovine spongiform encephalopathy (BSE). The incubation with tetracycline hydrochloride or doxycycline hyclate at concentrations ranging from 10 microM to 1 mM resulted in a dose-dependent decrease in protease resistance of PrP(Sc). This finding prompted us to investigate whether tetracyclines affect prion infectivity by using an animal model of disease. Syrian hamsters were injected intracerebrally with 263K scrapie-infected brain homogenate that was coincubated with 1 mM tetracycline hydrochloride, 1 mM doxycycline hyclate, or vehicle solution before inoculation. Hamsters injected with tetracycline-treated inoculum showed a significant delay in the onset of clinical signs of disease and prolonged survival time. These effects were paralleled by a delay in the appearance of magnetic-resonance abnormalities in the thalamus, neuropathological changes, and PrP(Sc) accumulation. When tetracycline was preincubated with highly diluted scrapie-infected inoculum, one third of hamsters did not develop disease. Our data suggest that these well characterized antibiotics reduce prion infectivity through a direct interaction with PrP(Sc) and are potentially useful for inactivation of BSE- or vCJD-contaminated products and prevention strategies.

Animals↗
PubMed2002

MR findings in Leigh syndrome with COX deficiency and SURF-1 mutations.

BACKGROUND AND PURPOSE: In a large number of patients with Leigh syndrome (LS) and cytochrome c oxidase (COX) deficiency, mutations of the SURF-1 gene were recently identified. The aim of the present study was to review the MR findings in patients with LS to verify if the genetically homogeneous patients with LS and SURF-1 mutations (LS SURF-1 patients) had a homogeneous MR pattern that could be used to differentiate them from other patients with LS (LS non-SURF-1 patients). METHODS: T1-, proton density-, and T2-weighted MR images of eight LS SURF-1 patients and 14 LS non-SURF-1 patients were reviewed. Enzymatic activity was determined according to standard methods. Genetic analysis was mostly performed by using stored DNA samples. RESULTS: All LS SURF-1 patients had lesions in the brain stem and subthalamic nuclei. Six had lesions in the cerebellum. Only two had basal ganglial abnormalities. Ten LS non-SURF-1 patients had lesions in the brain stem, but in six they were mild. Ten patients had basal ganglial abnormalities (nine of 10 in the putamina). LS-SURF-1 patients had a more severe clinical course. CONCLUSION: The MR pattern in LS SURF-1 patients is characteristic. Brain stem and subthalamic nuclei lesions may suggest the specific diagnosis. These patients die soon, probably because of lower brain stem involvement. Basal ganglial abnormalities are common only in LS non-SURF-1 patients. The absence of putaminal lesions, therefore, does not exclude the diagnosis of LS.

Brain↗