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C Mariani

Publications and source records attributed to C Mariani.

At least 19 recordsLinked to original sources
PubMed2003

Expression analysis of five tobacco EIN3 family members in relation to tissue-specific ethylene responses.

Ethylene induces different sets of genes in different tissues and at different stages of development. To investigate whether these differential responses are caused by differential expression of members of the EIN3 family transcription factors, five tobacco family members were isolated. They can be divided into three subgroups, which is probably due to the amphidiploid nature of tobacco. In phylogenetic analysis, each of the subgroups clustered with one of the three tomato EIL proteins and all NtEILs proved to be most homologous to Arabidopsis EIN3 and EIL1. Although organ-specific ethylene responses have been observed before, northern blot analysis showed that all NtEILs were expressed in all organs. To study differential NtEIL expression at the cellular level, in situ hybridization was used on the tobacco ovary. It was found that different ovary tissues displayed variable ethylene-induced expression of two ethylene-responsive marker genes. By contrast, no differences were found in expression level or tissue-specificity for any of the NtEILs in the ovary, before or after ethylene treatment. This indicates that the organ and tissue-specific ethylene responses are not caused by differential expression of NtEIL family members. These results support a model in which the developmental signals that regulate the tissue-specific responses are integrated with the ethylene signal downstream of a common primary ethylene-signalling pathway.

Arabidopsis Proteins↗
PubMed2003

Ethylene regulates the timing of anther dehiscence in tobacco.

We investigated the involvement of ethylene signaling in the development of the reproductive structures in tobacco ( Nicotiana tabacum L.) by studying flowers that were insensitive to ethylene. Ethylene-insensitivity was generated either by expression of the mutant etr1-1 ethylene-receptor allele from Arabidopsis thaliana or by treatment with the ethylene-perception inhibitor 1-methylcyclopropene (MCP). Development of ovaries and ovules was unaffected by ethylene-insensitivity. Anther development was also unaffected, but the final event of dehiscence was delayed and was no longer synchronous with flower opening. We showed that in these anthers degeneration of the stomium cells and dehydration were delayed. In addition, we found that MCP-treatment of detached flowers and isolated, almost mature anthers delayed dehiscence whereas ethylene-treatment accelerated dehiscence. This indicated that ethylene has a direct effect on a process that takes place in the anthers just before dehiscence. Because a similar function has been described for jasmonic acid in Arabidopsis, we suggest that ethylene acts similarly to or perhaps even in concurrence with jasmonic acid as a signaling molecule controlling the processes that lead to anther dehiscence in tobacco.

Cyclopropanes↗
PubMed2003

Interleukin-1B polymorphism is associated with age at onset of Alzheimer's disease.

Interleukin-1alpha (IL-1alpha) and IL-1beta are two pro-inflammatory cytokines involved in the pathogenesis of Alzheimer's disease (AD). The genes coding for IL-1alpha (IL-1A) and for IL-1beta (IL-1B) are clustered in chromosome 2q14-2q14.2. In a previous work, we investigated the role of IL-1A promoter polymorphism (-889 position) in AD pathogenesis: IL-1A -889 TT genotype was associated with sporadic early onset AD. We now report the study on polymorphism of exon 5 IL-1B in position +3953, the nearest polymorphism to -889 IL-1A. We found that the genotype distribution of IL-1B +3953 varied significantly between patients with early and late onset of AD (P<0.0001). Patients carrying IL-1B +3953 CT or TT genotypes had 4 or 5 years anticipation of AD onset (P=0.0034; odds ratio for early onset, 3.01) and 7 years anticipation if they also carried the IL-1A -889 TT genotype (P<0.0001; odds ratio for early onset, 7.4). These data further support a role for inflammation-related genes in AD or indicate linkage disequilibrium with an unknown chromosome 2 locus.

Aged↗
PubMed2003

Characterization and localization of the transmitting tissue-specific PELPIII proteins of Nicotiana tabacum.

The class III pistil-specific PELP proteins (PELPIII) of Nicotiana tabacum includes at least two members of highly soluble glycoproteins containing glucan modules that are characteristic for arabinogalactan proteins (AGPs). PELPIII accumulates in the style transmitting tissue (TT) during pistil development and, at flower anthesis, is present in the intercellular matrix (IM) of non-pollinated pistils. After pollination, PELPIII appears to be directly and completely translocated from the IM into the pollen tube callose walls, no significant accumulation was observed in the primary wall in the tip. In the spent parts of the pollen tubes these proteins become detectable against the remnants of the tube cell membrane and in the callose plugs. Different protein extraction procedures of PELPIII from pollinated tobacco pistils showed that these proteins remain in the highly soluble protein fraction and are not modified by the growing pollen tubes. These data concur with a role in IM development and pollen tube growth. In addition, the data show that the PELPIII are able to reach the cell membrane, facilitated by an already present or induced high porosity of the tube wall and an additional, yet unknown, mechanism. The differences in behaviour between the three related classes of style IM glycoproteins of Nicotiana, namely, PELPII, TTS and the 120 kDa glycoprotein, are proposed to connect more to their differences in glycosylation than to major differences in amino acid sequence.

Blotting, Western↗
PubMed2003

Functional neuroimaging (PET and SPECT) in the selection and assessment of patients with Parkinson's disease undergoing deep brain stimulation.

Deep brain Stimulation (DBS) is an effective treatment for patients with advanced Parkinson's disease (PD) and motor complications who can no longer be improved by adjustment of medical therapy. Selection of surgery candidates and follow-up after surgery are critical for good outcome. Functional neuroimaging can help in the clinical assessment of these patients. We have used single photon emission computed tomography (SPECT) and the tracer ECD to measure regional cerebral blood flow before and 6 months after DBS of the subthalamic nucleus (STN) in 20 patients with advanced PD. We found a significant increase in the anterior cingulate/supplementary motor cortex in the 12 good responders (change in off unified UPDRS >50%). Conversely, patients with poor response (n=8; change in off UPDRS-III <50% following DBS) revealed a significant worsening of cortical hypoperfusion particularly in the prefrontal areas. No flow decrements were detected in the basal ganglia and in the thalamus in both groups during DBS stimulation suggesting that DBS does not have a "lesion like" effect. If DBS stimulates and does not inactivate STN projection neurons, flow reduction in the poor responders may be secondary to increased inhibitory basal ganglia output.

Cerebrovascular Circulation↗
PubMed2002

Description of a cellulose-binding domain and a linker sequence from Aspergillus fungi.

A family I cellulose-binding domain (CBD) and a serine- and threonine-rich linker peptide were cloned from the fungi Aspergillus japonicus and Aspergillus aculeatus. A glutathione S-transferase (GST) fusion protein comprising GST and a peptide linker with the CBD fused to its C-terminus, was expressed in Escherichia coli. The renatured GST-CBD recovered from inclusion bodies had a molecular mass of 36.5 kDa which agrees with the 29 kDa of the GST plus the calculated 7.5 kDa of the linker with the CBD. The isolated GST-CBD protein adsorbed to both bacterial microcrystalline cellulose and carboxymethyl cellulose. Deletion of the linker peptide caused a decrease in cellulose adsorbance and a higher sensitivity to protease digestion.

Amino Acid Sequence↗
PubMed2002

General Knowledge of the World: a standardised assessment.

An entirely verbal enquiry of "General Knowledge of the World" made up by 168 questions exploring 14 domains of knowledge (12 questions each) has been standardised on 175 (97 women and 78 men) healthy Italian subjects with at least 8 years of formal education. Norms for each set of questions are provided. An unexpected finding is that age did not play an influential role on performance, whereas education did: the higher it was, the better the score. Women proved to fare significantly worse than men. A feasibility check on 30 Alzheimer patients with very mild overall cognitive impairment showed that the general knowledge enquiry was relatively easy to administer. The discrimination power between normal controls and Alzheimer patients for each subtest has been calculated.

Adult↗
PubMed2002

Expression of the ACC synthase and ACC oxidase coding genes after self-pollination and incongruous pollination of tobacco pistils.

In tobacco, as in other species, ethylene is produced in response to pollination. Although tobacco is a self-compatible species, it displays unilateral incongruity with other Nicotiana plants. Incongruous pollination also results in ethylene production, but this production differs depending on the pollen used and is related to the extent to which pollen tubes grow in the tobacco style. In the investigation reported here we followed the expression of the ACC synthase- and ACC oxidase-coding genes upon pollination of tobacco pistils and compared self-pollination with incongruous pollination. The pattern of expression of these genes also correlated with pollen-tube growth, although wounding alone cannot explain the results obtained. We also examined the expression of these genes upon pollination of immature tobacco pistils, in which different pollen tubes grew indistinctly inside the tobacco style and reached the ovary at the same rate. In this situation no significant differences in gene expression could be observed between the different pollinations. Ethephon, a substance that produces ethylene, could, in some cases, minimize the arrest of incongruous pollen tubes inside the style.

Amino Acid Oxidoreductases↗
PubMed2002

Comparing two programs of cognitive training in Alzheimer's disease: a pilot study.

OBJECTIVES: To evaluate the efficacy of two different procedures of individual cognitive training in mild to moderate Alzheimer's Disease (AD). MATERIAL AND METHODS: Twenty-two AD patients entered the study. We compared stimulation of procedural memory (group 1) with training of partially spared cognitive functions (group 2). Assessment included: neuropsychological tests, scales, and the Functional Living Skills Assessment (FLSA), a standardized battery built to directly evaluate patients' performance in everyday life. RESULTS: We observed a significant improvement for both groups after training in FLSA total score (P=0.005) and subscales. For group 1, we also found a slightly improved performance in two tests: Attentional Matrices (P=0.041), and Verbal Fluency for Letters (P=0.059). After 3 months, patients' results showed a tendency to regress to the pre-training level. CONCLUSION: Both AD groups showed a substantial improvement after training in a direct performance measure of everyday functioning. However, results at neuropsychological tests suggest that training activities of daily living (supported by procedural memory) may be more effective than stimulating "residual" cognitive functions.

Aged↗
PubMed2002

Frontal impairment in subcortical ischemic vascular dementia in comparison to Alzheimer's disease.

We compared the performance of patients with Alzheimer's disease to that of patients with subcortical vascular dementia (s-IVD) in a set of tasks assessing categorization abilities, sustained and selective attention, and set-shifting and set-maintaining skills. Only the measures of naming and categorization abilities on the Test of Classification and Recall of Pictures (TCRP) proved useful in differentiating AD from s-IVD patients. s-IVD patients showed worse performance than AD on the TCRP categorization measures, while both AD and s-IVD patients were equally impaired in other tasks assessing executive functions (EF). With respect to the naming task, s-IVD patients made significantly more perseverative and unrelated errors than AD patients. Moreover, in the s-IVD group, we found a strong correlation between categorization ability and an attentional test score (Attentional Matrices), while no such correlation emerged in the AD group. These results suggest a dissociated impairment of EF in the 2 dementia groups. In our view, the lack of inhibition and the inability to manipulate complex information are responsible for a greater executive dysfunction in s-IVD patients in comparison with AD patients. The capacity to build up strategies appears more preserved in AD patients, whose impaired performance in executive tasks seems to be related to an impairment of attentional shifting and working memory.

Aged↗
PubMed2001

Ethylene response to pollen tube growth in Nicotiana tabacum flowers.

In flowers of Nicotiana tabacum L., pollination induces a transient increase in ethylene production by the pistil. The characteristic dynamics of the increase in ethylene correspond to the main steps of the pollen-tube journey into the pistil: penetration into the stigma, growth through the style, entry into the ovary and fertilization. Ethylene is synthesized de novo in the pistil, and its production is reduced in the dark. Ethylene production was monitored in tobacco flowers after pollination with incongruous pollen from three different Nicotiana species, N. rustica, N. repanda and N. trigonophylla, and with pollen from Petunia hybrida. Pollen from all of these different sources can germinate on the stigma surface but each pollen type shows a different behavior and efficiency in penetrating the pistil tissues. Thus, these different crosses provided a model with which to study the response of the pistil to pollination and fertilization. Ethylene evolution upon pollination in tobacco differed in each cross, suggesting that ethylene is correlated with the response to pollen tube growth in the tobacco flower.

Amino Acids, Cyclic↗
PubMed2001

New mutation (R42P) of the parkin gene in the ubiquitinlike domain associated with parkinsonism.

OBJECTIVE: To investigate the association between parkin gene mutations and parkinsonism in an Italian family in which three of 12 siblings born to first-degree consanguineous parents had early-onset parkinsonism. BACKGROUND: Several deleting or truncating mutations as well as missense mutations of the parkin gene were associated with early-onset parkinsonism. METHOD: Three brothers were examined clinically at several stages of the disease. Single-strand conformational polymorphism analysis was done on the parkin gene of 32 members of the family. Samples showing mobility shifts were considered for mutation analysis. RESULTS: Direct DNA sequencing revealed a novel homozygous amino acid substitution, Arg42Pro, in all three patients compared with a control DNA sample. The mutation occurred in the ubiquitinlike domain at the N-terminal of the protein. The patients did not display the clinical hallmarks previously seen with parkin mutations and were indistinguishable from patients with sporadic PD. CONCLUSIONS: These findings confirm the recessive character of parkin mutations causing early-onset parkinsonism and the essential role of the ubiquitinlike region, highly conserved among species, and in accordance with the proposed parkin function.

DNA↗
PubMed2001

Hydroxyproline-rich glycoproteins in plant reproductive tissues: structure, functions and regulation.

The plant reproductive process of pollination involves a series of interactions between the male gametophyte (the pollen grain or pollen tube) and extracellular matrix (ECM) molecules secreted by different cell types along the pollen tube growth pathway in the female organ, the pistil. These interactions are believed to signal and regulate the pollen tube growth process to effect successful delivery of the sperm cells to the ovules where fertilization takes place. Hydroxyproline-rich glycoproteins secreted by plant cells are believed to play a broad range of functions, ranging from providing structural integrity to mediating cell-cell interactions and communication. The pistil and pollen tube ECM is enriched in these highly glycosylated proteins. Our discussions here will focus on a number of these proteins for which most information has been available, from Nicotiana tabacum, its self-incompatible relative N. alata, and Zea mays. In addition, the regulation of the synthesis and glyco-modification of one of these proteins, TTS (transmitting tissue-specific) protein from N. tabacum will be discussed in the light of how differential glycosylation may be used to regulate molecular interactions within the ECM.

Extracellular Matrix↗
PubMed2001

Class III pistil-specific extensin-like proteins from tobacco have characteristics of arabinogalactan proteins.

Class III pistil-specific extensin-like proteins (PELPIII) are specifically localized in the intercellular matrix of tobacco (Nicotiana tabacum) styles. After pollination the majority of PELPIII are translocated into the callosic layer and the callose plugs of the pollen tubes, which could suggest a function of PELPIII in pollen tube growth. PELPIII may represent one of the chemical and/or physical factors from the female sporophytic tissue that contributes to the difference between in vivo and in vitro pollen tube growth. PELPIII glycoproteins were purified and biochemically characterized. Because of their high proline (Pro) and hydroxy-Pro (Hyp) content, PELPIII proteins belong to the class of Pro/Hyp-rich glycoproteins. The carbohydrate moiety of PELPIII is attached through O-glycosidic linkages and comprises more than one-half the total glycoprotein. Deglycosylation of PELPIII revealed two backbones, both reacting with PELPIII-specific antibodies. N-terminal amino acid sequencing of these backbones showed that PELPIII is encoded by the MG14 and MG15 genes. Two heterogeneous N-terminal sequences of MG14 and MG15, both starting downstream of the predicted signal peptide cleavage site, seem to be present, which indicates a novel N-terminal processing. Monosaccharide analysis showed that the carbohydrate moiety of PELPIII almost completely consists of arabinose and galactose in an equal molar ratio. Carbohydrate linkage analysis showed terminal and 2-linked arabinofuranosyl residues, as well as terminal and 6-, 3-, and 3,6-linked galactopyranosyl residues to be present, indicating the presence of both extensin-like and Type II arabinogalactan oligosaccharide units. The ability of beta-glucosyl Yariv reagent to bind with PELPIII confirmed the arabinogalactan protein-like characteristics of these proteins.

Amino Acid Sequence↗
PubMed2000

Hereditary hemochromatosis in a patient with congenital dyserythropoietic anemia.

Herein is described the case of a young woman presenting with iron overload and macrocytosis. The initial diagnosis was hereditary hemochromatosis. Severe anemia developed after a few phlebotomies, and she was also found to have congenital dyserythropoietic anemia that, though not completely typical, resembled type II. Only genetic testing allowed the definition of the coexistence of the 2 diseases, both responsible for the iron overload. This report points out the need to consider congenital dyserythropoietic anemia in patients with hemochromatosis and unexplained macrocytosis and, conversely, to check for the presence of hereditary hemochromatosis in patients with congenital dyserythropoietic anemia and severe iron overload. To the authors' knowledge, this is the first report of homozygosity for the C282Y mutation of the HFE gene in a patient affected by congenital dyserythropoietic anemia.

Adult↗
PubMed2000

Visual feedback has differential effects on reaching movements in Parkinson's and Alzheimer's disease.

We examine the role of visual feedback in the programming and execution of reaching movement in patients with Parkinson's disease without cognitive impairment and patients with Alzheimer's disease without extrapyramidal signs. Controls were normally aging subjects. All subjects moved a cursor to targets on a digitizing tablet without seeing their limb. Starting and target positions were always visible on a screen while, during movement, cursor position was either visible or blanked. They were instructed to make uncorrected movements, as fast and as accurate as possible without minimizing reaction time. In absence of visual feedback, movement accuracy in patients with AD was severely impaired. Hand paths of parkinsonian patients were as accurate as normal subjects' with similar temporal velocity profiles and movement speed. With cursor feedback, accuracy was the same in the three groups, although movement speed and transport phase in patients with Alzheimer's disease were significantly reduced compared to the other groups. Also, movements of parkinsonian patients showed shorter transport phase and lower mean velocity than controls'. The different characteristics of the motor performance suggests that in the two diseases visual information is used differently for both motor programming and execution: patients with Alzheimer's disease, while scarcely using feed forward commands, relied on continuous on-line external cues. The correlation of motor performance with cognitive impairment argues against the hypothesis of basal ganglia involvement in AD. The motor abnormalities we found may represent early subclinical manifestation of apraxic disturbance. Parkinsonian patients showed higher reliance on feedback commands only with cursor feedback: this could be explained by their difficulty in engaging effectively automatic routines when distractors are present.

Aged↗
PubMed2000

Selective uppercase dysgraphia with loss of visual imagery of letter forms: a window on the organization of graphomotor patterns.

We report a patient who, after a left parieto-occipital lesion, showed alexia and selective dysgraphia for uppercase letters. He showed preserved oral spelling, associated with handwriting impairment in all written production; spontaneous writing, writing to dictation, real words, pseudowords, and single letters were affected. The great majority of errors were well-formed letter substitutions: most of them were located on the first position of each word, which the patient always wrote in uppercase (as he used to do before his illness). The patient also showed a complete inability to access the visual representation of letters. As demonstrated by a stroke segmentation analysis, letter substitutions followed a rule of graphomotor similarity. We propose that the patient's impairment was at the stage where selection of the specific graphomotor pattern for each letter is made and that the apparent selective disruption of capital case was due to a greater stroke similarity among letters belonging to the same case. We conclude that a visual format is necessary neither for spelling nor for handwriting.

Aged↗