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M Pesenti

Publications and source records attributed to M Pesenti.

16 recordsLinked to original sources
PubMed2000

Number processing and calculation in a case of visual agnosia.

We describe the performance of a brain-damaged subject who suffered from visual agnosia leading to major difficulties in generating and exploiting visual representations from long-term memory. His performance in a physical judgement task in which he was required to answer questions about the visual shapes of Arabic numerals reflected his agnosic problems. However, he showed no impairment in usual number processing and calculation tasks. This case shows that, despite some commonalities in number and object processing, actual numerical processes are not affected by visual agnosia and can be preserved even when fine visual processes are impaired.

Agnosia↗
PubMed2000

Noncommutability of the N + 0 arithmetical rule: a case study of dissociated impairment.

It has been shown that some arithmetical problems are stored in the form of individual facts representations (e.g., 3 x 4 = 12) whereas others are solved by general stored rules (e.g., 0 x N = 0). We describe the performance of a brain-damaged subject who presented a mild impairment in arithmetical fact retrieval. Although her performance was almost perfect for rule-based problems in all arithmetical operations, she was severely impaired for 0 + n problems in contrast with her relatively good performance for the corresponding n + 0 problems. This dissociation extends to addition the noncommutability of arithmetical rules described in multiplication.

Aphasia↗
PubMed2000

Neuroanatomical substrates of arabic number processing, numerical comparison, and simple addition: a PET study.

Positron emission tomography was used to localize the cerebral networks specifically involved in three basic numerical processes: arabic numeral processing, numerical magnitude comparison, and retrieval of simple addition facts. Relative cerebral blood flow changes were measured while normal volunteers were resting with eyes closed, making physical judgment on nonnumerical characters or arabic digits, comparing, or adding the same digits. Processing arabic digits bilaterally produced a large nonspecific activation of occipito-parietal areas, as well as a specific activation of the right anterior insula. Comparison and simple addition fact retrieval revealed a fronto-parietal network involving mainly the left intraparietal sulcus, the superior parietal lobule and the precentral gyrus. Comparison also activated, but to a lesser extent, the right superior parietal lobe, whereas addition also activated the orbito-frontal areas and the anterior insula in the right hemisphere. Implications for current anatomo-functional models of numerical cognition are drawn.

Adult↗
PubMed1999

Parathyroid incidentaloma discovered during thyroid ultrasound imaging.

We report two patients with incidentally discovered enlarged parathyroid glands while performing neck ultrasonography (US) for thyroid nodules. The parathyroid masses were seen as hypoechoic, homogeneous, oval nodules, separated from the thyroid gland. Both patients were completely asymptomatic, although subclinical evidence of hyperparathyroidism (serum PTH and calcium levels in the upper limit of the normal range, increased ionized serum calcium, osteocalcin, urinary calcium and hydroxyproline) was subsequently found in one patient. An enhanced uptake on sesta-MIBI scinti scan was concordant with the US finding in the two cases. PTH levels in the wash-out from the US-guided fine needle aspiration biopsy, confirmed the parathyroid origin of the lesions. Cytology and immunocytochemistry were, in our cases, unreliable diagnostic procedures. The extensive use of US imaging in thyroid pathology may increase the finding of US incidentally discovered parathyroid adenomas. The early detection of silent parathyroid pathologic findings may extend the natural history of these masses to a preclinical stage. Further investigations are necessary to evaluate the evolution of parathyroid incidentalomas and therefore their clinical significance.

Calcium↗
PubMed1999

Effect of growth temperature on the biosynthesis of cell wall proteins from Bifidobacterium globosum.

Seventy strains of Bifidobacterium globosum isolated from gastrointestinal tracts of different animals were studied. Strains were grown at temperatures ranging from 25 to 46.5 degrees C in order to examine changes both in the expression of bifidobacterial outer proteins (BIFOPs) and in their hydrophobic properties. It was observed that the expression of BIFOPs found on the cell-surface changes according to growth temperature, with quantitative and/or qualitative variations. Generally speaking, it was observed that BIFOP expression at low-growth temperature was considerably attenuated, while at medium- and high-growth temperature it increased. Furthermore, at high-growth temperatures, the presence of a new common protein was detected in all the strains studied. Cells from B. globosum strains grown under different temperature conditions were studied in terms of their cellular hydrophobicity properties. At medium-growth temperature, the cell hydrophobicity was strictly correlated with BIFOP expression, while at low and high-growth temperatures, the presence of BIFOP only partially influenced the hydrophobic features.

Animals↗
PubMed1999

Bifidobacterium animalis protects intestine from damage induced by zinc deficiency in rats.

We investigated the potential beneficial effects of Bifidobacterium animalis on intestinal damage using zinc-deficient (ZD) rats as a model for intestinal alterations. The ZD rats were fed diets containing 1 mg Zn/kg for 20 (ZD(20)) or 40 (ZD(40)) d to induce damage that differed in severity. Subgroups of these rats, the ZD(20) + B and ZD(40) + B groups, received a suspension of B. animalis (3.5 x 10(8) colony forming units) daily for the last 10 d. Another subgroup, the ZD(40) + B + 7 d group, was fed the ZD diet for 7 d after the B. animalis treatment period. Zinc deficiency induced ulcerations, edema, inflammatory cell infiltration and dilatation of blood vessels in duodenum, jejunum and ileum, with increasing severity between 20 and 40 d of zinc deficiency. The mucosa of the ZD(20) + B group was well preserved, and most of the morphologic alterations induced by zinc deficiency were normalized in the ZD(40) + B group. The high fecal concentrations of B. animalis in the ZD(40) + B and ZD(40) + B + 7 d groups indicate that these bifidobacteria survived passage through the gastrointestinal tract and proliferated. Electron microscopy confirmed the elevated numbers of bifidobacteria in cecum. Treatment with B. animalis resulted in greater epithelial cell proliferation and disaccharidase activities in the ZD(40) + B group compared with the ZD(40) group. These findings indicate that B. animalis can protect the intestine from alterations induced by zinc deficiency, suggesting that this bacterium may play a role in intestinal mucosal defense.

Animals↗
PubMed1998

Age-related differences in random generation.

This study investigated the effects of age on a random generation task. In Experiment 1, young and elderly subjects were asked to generate random strings of letters at 1-, 2-, and 4-s rates. The elderly subjects produced more alphabetical stereotype responses than young subjects, even in the slowest rate condition. Furthermore, as faster rates were imposed, elderly subjects could no longer maintain the pace and missed responses. In Experiment 2, subjects were required to generate letters at the same time that they sorted cards into one, two, four, or eight categories. Age-related differences were observed on most of the measures of randomness (stereotypes, zero-order, and first-order measures). In addition, the number of errors increased with the number of sorting alternatives, especially for elderly subjects. These results suggest the existence of a reduction of the central executive resources, along with a reduced inhibition ability, in the elderly subjects. However, the contribution of a perceptual speed factor is also discussed.

Adult↗
PubMed1998

[Efficacy of delayed-release lanreotide in the medical therapy of acromegaly].

BACKGROUND: The efficacy of 6 months therapy with slow-release lanreotide (30 mg i.m. every 10-14 days) in 8 acromegalic patients has been studied. METHODS: These patients had been previously treated (for 62 +/- 5.7 months) with octreotide (100 micrograms t.i.d.) and therefore presented, at the beginning of the study, normal mean GH (3.5 +/- 1.1 ng/ml) and IGF-1 (301.7 +/- 32.9 ng/ml) plasma levels. After a week of wash-out, mean GH (5.5 +/- 1.3 ng/ml) and IGF-1 (523.8 +/- 26.7 ng/ml) plasma levels showed a significant increase (p < 0.01) compared to the values observed during the treatment with octreotide. All 8 acromegalic patients then started the treatment with lanreotide, 30 mg i.m. After 14 days, mean GH plasma levels (4.2 +/- 1.3 ng/ml) did not significantly differ (p = NS) from those observed in the same group of patients during treatment with octreotide, whilst plasma IGF-1 levels (477 +/- 43 ng/ml) were significantly higher (p < 0.05). Four patients, in which mean plasma GH values resulted < 5 ng/ml, continued the therapy with lanreotide every 14 days. In the remaining 4 patients, in which plasma GH values were > 5 ng/ml, lanreotide was administered every 10 days. RESULTS: After 3 months of therapy, 6 out of the 8 patients presented persistent GH levels < 5 ng/ml during the day, with IGF-1 levels comparable to those observed during treatment with octreotide. The other 2 subjects presented plasma GH levels > 5 ng/ml during the day, with increased plasma levels of IGF-1. This latter group of patients was resubmitted treatment with octreotide, 100 micrograms t.i.d. After 6 months of therapy, all 6 patients presented GH and IGF-1 plasma levels comparable to those observed during treatment with octreotide. CONCLUSIONS: These data show that slow-release lanreotide can be a valid therapeutic alternative to octreotide in the medical treatment of acromegalic patients.

Acromegaly↗
PubMed1997

[Mammary carcinoma in a patient with hyperprolactinemia].

In 1990, a 50 year-old man was referred to us for hyperprolactinemia. At 37 years of age the patient had undergone left mastectomy, for a histologically confirmed gynecomastia and, in 1989, he had undergone pituitary adenomectomy, for a PRL secreting macroadenoma (PRL = 3520 ng/ml). Persistently high PRL plasma levels (PRL = 550 ng/ml) showed an incomplete surgical removal of the adenoma and as a consequence, radiotherapy of the pituitary area was performed in 1990. When the patient referred to us, PRL plasma levels were still pathologic and medical therapy with bromocriptine was started. A year later a replacement therapy with cortisone, testosterone, L-thyroxine, was commenced, as the patient presented a post-radiotherapy hypopituitarism. Since the treatment with bromocriptine was unsuccessful, the drug was replaced with cabergoline, but not even the latter was able to normalize PRL plasma levels. In 1996, a nodule of 3 cm in diameter was discovered under his right mammary areola. The nodule biopsy showed a grade II infiltrating ductal breast carcinoma positive to the estrogen and progesterone receptors analysis. A right total mastectomy was performed and the diagnosis was confirmed through histological examination. A case of gynecomastia and breast cancer in a male patient who had been exposed to high PRL plasma levels for several years is reported. In this patient, both elevated PRL plasma levels and a relative hyperestrogenic state may have contributed to originate breast cancer.

Adult↗
PubMed1994

Selective impairment as evidence for mental organisation of arithmetical facts: BB, a case of preserved subtraction?

We report here the case of a patient (BB), suffering from a precocious evolving dementia with impaired arithmetic performance, who showed specific and theoretical pertinent dissociations in basic mental arithmetic. First, in a task involving production of answers to simple arithmetic problems, a strong dissociation was found among operation: while multiplication was severely impaired, addition was moderately and subtraction only slightly impaired. A second dissociation was found between problems potentially solvable by rules and the others, with the former being better preserved. Finally, in multiplication verification tasks, the rate and distribution of errors among problems were not different from those observed in the multiplication production task. This pattern of performance like the one presented by the patient RG (Dagenbach and McCloskey, 1992), suggests first that stored arithmetical fact representations are segregated by arithmetic operation and second that a distinction has to be drawn between arithmetical rules and arithmetical facts. Last, the parallelism of performance observed here in verification and production tasks suggests that the same deficit(s) is (are) responsible for errors in both tasks.

Adult↗
PubMed1992

Images of numbers, or "When 98 is upper left and 6 sky blue".

Some people declare that they possess a personal visual representation of numbers: some automatically "see" the numbers they are confronted with in a precise location in a structured mental space, others "associate" specific colours with given numbers. Such visuo-spatial representations of numbers were first described by Galton in 1880 but have since received little attention from psychologists. It is the aim of this article to describe these mental representations and discuss their role in number processing. The authors first review Galton's observations, and then present their own. Finally, they discuss the relevance of these visuo-spatial representations in relation to contemporary debates on number representation and calculation.

Adult↗
PubMed1989

Antihypertensive effect of slow-release nicardipine. A placebo-controlled cross-over study.

The magnitude and duration of the antihypertensive effect of slow-release nicardipine (SR-Nicardipine) have been compared with placebo in 36 uncomplicated essential hypertensives (diastolic BP 95 to 115 mm Hg after 1-month placebo washout). According to a double-blind, randomized, cross-over design they received SR-Nicardipine 40 mg b.d. and placebo for 1 month. At the end of each treatment period, blood pressure and heart rate were measured 12 h after the evening dose and 1, 2, 3 and 4 h after the morning dose. SR-Nicardipine significantly reduced systolic (SBP) and diastolic (DBP) blood pressure at each time after dosing. The absolute decrements peaked 4 h after dosing (-18.3 and -11.7 mm Hg, respectively) and more than 90% of the peak effect persisted 12 h after dosing, both for SBP and DBP. The heart rate was slightly increased by SR-Ni-cardipine. Adverse effects monitored with a check-list occurred in 31% of patients during SR-Nicardipine treatment and in 28% on placebo. Thus, SR-Nicardipine 40 mg b.d. has a maintained and significant antihypertensive effect lasting up to 12 h in essential hypertension.

Adult↗
PubMedDate not supplied

Detection and diagnosis of parathyroid incidentalomas during thyroid sonography.

PURPOSE: The aim of our study was to evaluate the incidence of incidentally found parathyroid adenomas (incidentalomas) in patients undergoing sonography of the neck for thyroid disease. METHODS: A total of 1,686 patients (305 men and 1,381 women) underwent sonography of the neck; the mean age was 49.6 +/- 21.7 years. In 38 patients (2.3%; 7 men and 31 women) with a mean age of 48.7 +/- 14.7 years, hypoechoic, homogeneous, oval nodules (mean volume, 1.0 +/- 0. 9 cm(3)) adjacent to the thyroid parenchyma were observed. All these lesions, compatible with the shape of an enlarged parathyroid gland, underwent ultrasound-guided fine-needle aspiration biopsy (FNAB), with measurement of parathyroid hormone (PTH) and thyroglobulin (Tg) levels in the needle washings (FNAB-PTH and FNAB-Tg). Biochemical screening for hyperparathyroidism was also performed. RESULTS: Cytologic examination plus FNAB-PTH/FNAB-Tg measurements revealed the presence of cellular material consistent with parathyroid tissue in 9 patients (24%), thyroid tissue in 22 patients (58%), and lymphoid tissue in 4 patients (11%). A tissue diagnosis was not established in 3 patients (8%). Five of 9 patients with parathyroid enlargement had high serum PTH and calcium levels. CONCLUSIONS: Enlarged parathyroid glands may be incidentally discovered during sonography of the thyroid. In patients with thyroid disease, the positive-predictive value of sonography in the identification of parathyroid tissue was low. Ultrasound-guided FNAB-PTH determination should be carried out when parathyroid adenoma is suspected. The incidental finding of an enlarged parathyroid may or may not be associated with yet undiagnosed hyperparathyroidism.

Adenoma↗