Papers by Daniela Daniela
Editura Anima, Bucureşti, 1990
Nature, 1993
An extracellular serine protease (Ac1) with a molecular mass of 35 kDa was puriWed from the nemat... more An extracellular serine protease (Ac1) with a molecular mass of 35 kDa was puriWed from the nematodetrapping fungus Arthrobotrys conoides. The optimum activity of Ac1 is at pH 7.0 and 53.2°C (over 20 min). Ac1 can degrade a broad range of substrates including casein, gelatin, bovine serum albumin, collagen, and nematode cuticles. Moreover, the enzyme can immobilize the freeliving nematode Panagrellus redivivus and the pine wood nematode Bursaphelenchus xylophilus, indicating Ac1 may be involved in infection against nematodes. The encoding gene of Ac1 contains one intron of 60-bp and two exons encoding a polypeptide of 411 amino acid residues. The deduced polypeptide sequence of Ac1 showed a high degree of similarity to two previously reported serine proteases PII and Mlx from other nematode-trapping fungi (81% aa sequence identity). However, three proteases Ac1, Aoz1 and Mlx showed optimum temperatures at 53.2, 45 and 65°C, respectively. Compared to PII, Ac1 appears to have a signiWcantly higher activity against gelatin, bovine serum albumin, and non-denatured collagen. Moreover, our bioassay experiments showed that Ac1 is more eVective at immobilizing P. redivivus than B. xylophilus.
PLOS Pathogens, 2009
The basidiomycete Ustilago maydis causes smut disease in maize. Colonization of the host plant is... more The basidiomycete Ustilago maydis causes smut disease in maize. Colonization of the host plant is initiated by direct penetration of cuticle and cell wall of maize epidermis cells. The invading hyphae are surrounded by the plant plasma membrane and proliferate within the plant tissue. We identified a novel secreted protein, termed Pep1, that is essential for penetration. Disruption mutants of pep1 are not affected in saprophytic growth and develop normal infection structures. However, Dpep1 mutants arrest during penetration of the epidermal cell and elicit a strong plant defense response. Using Affymetrix maize arrays, we identified 116 plant genes which are differentially regulated in Dpep1 compared to wild type infections. Most of these genes are related to plant defense. By in vivo immunolocalization, live-cell imaging and plasmolysis approaches, we detected Pep1 in the apoplastic space as well as its accumulation at sites of cell-to-cell passages. Sitedirected mutagenesis identified two of the four cysteine residues in Pep1 as essential for function, suggesting that the formation of disulfide bridges is crucial for proper protein folding. The barley covered smut fungus Ustilago hordei contains an ortholog of pep1 which is needed for penetration of barley and which is able to complement the U. maydis Dpep1 mutant. Based on these results, we conclude that Pep1 has a conserved function essential for establishing compatibility that is not restricted to the U. maydis / maize interaction.
Current Drug Targets - Cns & Neurological Disorders, 2005
Drug dependence is a chronically relapsing disorder, manifested as an intense desire for the drug... more Drug dependence is a chronically relapsing disorder, manifested as an intense desire for the drug, with impaired ability to control the urges to take the drug, even at the expense of serious adverse consequences. These behavioral abnormalities develop gradually during repeated exposure to a drug of abuse, and can persist for months or years after discontinuation of use, suggesting that this addiction can be considered a form of drug-induced neural plasticity. Many neurotransmitters, including gamma-aminobutyric acid (GABA), glutamate, acetylcholine, dopamine, serotonin and endogenous opioid peptides, have been implicated in the effects of the various drugs of abuse. Dopamine has been consistently associated with the reinforcing effects of most of them. There is, in addition, a growing body of evidence that the endogenous cannabinoid system might participate in the motivational and dopamine-releasing effects of several drugs of abuse. This review will discuss the latest advances on the mechanisms of cannabinoid dependence and the possible role of the endocannabinoid system in the treatment of addiction, not only to marijuana but also to the other common illicit drugs.
Archives of Environmental Health, 2000
Chromosome analysis was conducted for peripheral lymphocytes of 23 printers exposed to toluene co... more Chromosome analysis was conducted for peripheral lymphocytes of 23 printers exposed to toluene concentrations of 590 mg/m3 in a rotary machine workshop and to rotogravure printing inks. The percentages of aberrant cells were 2.30 in the printers and 1.46 in the control group (n = 22) (p < .05). The concentration of hippuric acid in printers was significantly higher than in the control group (p < .01), and the level of blood toluene at the end of the workshift was 0.500 mg/l. The authors also examined rotogravure printing inks-considered a potential source of genotoxic polycyclic aromatic hydrocarbons because they contained carbon black-their use in printing plants, and previous documentation of increased chromosomal aberrations in rotogravure printers. Only milligrams of fluorene and phenanthrene per gram of the printing inks were found; no polycyclic aromatic hydrocarbons with carcinogenic properties were discovered in the inks. The authors used Salmonella typhimurium indicator strains TA 98, TA 100, TA 1537, and YG 1041 in spot tests and indicator strains TA 98 and TA 100 in plate-incorporation assays to determine that there was no bacterial mutagenicity of all four colors of rotogravure inks. Urinary mutagenicity, which was evaluated with a microsuspension assay containing YG 1041 indicator strain both in the presence and absence of metabolic activation, was also studied. No significant difference in bacterial mutagenicity was found between the exposed and control groups. The increased percentage of aberrant cells in printers can be explained by exposure to genotoxicants that are not excreted in urine. Toluene was the most likely cause of the aberration.
Neurology, 1994
We developed a new instrument, the Neuropsychiatric Inventory (NPI), to assess 10 behavioral dist... more We developed a new instrument, the Neuropsychiatric Inventory (NPI), to assess 10 behavioral disturbances occurring in dementia patients: delusions, hallucinations, dysphoria, anxiety, agitation/aggression, euphoria, disinhibition, irritability/lability, apathy, and aberrant motor activity. The NPI uses a screening strategy to minimize administration time, examining and scoring only those behavioral domains with positive responses to screening questions. Both the frequency and the severity of each behavior are determined. Information for the NPI is obtained from a caregiver familiar with the patient's behavior. Studies reported here demonstrate the content and concurrent validity as well as between-rater, test-retest, and internal consistency reliability; the instrument is both valid and reliable. The NPI has the advantages of evaluating a wider range of psychopathology than existing instruments, soliciting information that may distinguish among different etiologies of dementia, differentiating between severity and frequency of behavioral changes, and minimizing administration time.
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Papers by Daniela Daniela