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Biomedical subjects

C Martinelli

Publications and source records attributed to C Martinelli.

At least 37 records · Page 2Linked to original sources
PubMed1997

Age-related decrease of the perineuronal satellite cell number in the rabbit spinal ganglia.

This study was undertaken to establish whether a change in the perineuronal satellite cell number contributes to the age-related reduction of the volume ratio between the perineuronal glial sheaths and their associated nerve cell bodies, observed to occur in rabbit spinal ganglia. The volumes of the nerve cell bodies and the numbers of the related satellite cell nuclei were estimated on serial semithin sections from young adult and old rabbits. As satellite cells are mononucleate, the number of the nuclei corresponds to that of these cells. The satellite cell sheaths in both age groups were also examined under the electron microscope. The mean number of satellite cells was significantly smaller in the aged animals than in the young adults although the mean volume of the nerve cell bodies was significantly larger in the former. Cytoplasmic vacuoles, invaginations of the connective tissue and autophagic vacuoles were more frequent in the old rabbits. Satellite cells with pyknotic nuclei and remnants of degenerated satellite cells were only found in aged animals, although rather rarely. The decrease in the satellite cell number is one of the mechanisms by which the age-related reduction of the volume ratio between the perineuronal glial sheaths and their associated nerve cell bodies takes place. The decrease in the satellite cell number seems to occur, at least in part, through cell degeneration. However, other mechanisms (e.g., detachment of satellite cells from the perineuronal sheaths) cannot be excluded. Since satellite cells play a role in neuronal support, the significant decrease in their number probably has negative consequences for neuronal activity.

Aging↗
PubMed1996

Increase in circulating products of lipid peroxidation in smokers with IDDM.

OBJECTIVE: To measure plasma malondialdehyde (MDA) concentration, a product of lipid peroxidation, both in IDDM patients and in healthy control subjects and to examine whether smoking has a negative impact on the plasma MDA levels in diabetic patients. RESEARCH DESIGN AND METHODS: Plasma total MDA concentration (as a thiobarbituric acid adduct by high-performance liquid chromatography) was measured in 56 young IDDM patients and in a group of 32 age-, sex-, BMI-, and smoking habit-matched healthy subjects. RESULTS: Plasma MDA concentration in IDDM patients was significantly higher than that in healthy control subjects (mean +/- SE: 0.95 +/- 0.03 vs. 0.54 +/- 0.03 mumol/l; P < 0.0001). After stratification by smoking status, it was seen that diabetic smokers had values of age, BMI, serum lipids, blood pressure, metabolic control, and diabetes duration and its chronic complications superimposable on those of their nonsmoking counterparts. Nevertheless, plasma MDA concentration was significantly higher in IDDM patients who smoked than in IDDM patients who didn't smoke (1.03 +/- 0.4 vs. 0.87 +/- 0.03 mumol/l; P = 0.002), without any sex difference with regard to MDA levels. CONCLUSIONS: These data show an increase in circulating products of lipid peroxidation in young diabetic smokers, thus further supporting the clinical importance of discouraging the initiation of smoking as well as promoting its cessation in people with IDDM.

Adult↗
PubMed1994

The insulin-like growth factor I generation test in the investigation of short stature.

Genotypic and phenotypic heterogeneity in patients with growth hormone (GH) insensitivity syndrome suggests that partial defects exist in the GH receptor. The insulin-like growth factor I (IGF-I) generation test was assessed as a means of identifying partial GH receptor defects in a heterogeneous group of 22 prepubertal children with short stature. In a subgroup of nine patients with peak GH levels of 63.7 +/- 3.7 mU/l during a glucagon tolerance test, the response to the IGF-I generation test was no different from that for the group as a whole (peak GH, 43.3 +/- 4.5 mU/l), despite the fact that this subgroup exhibited a negative relationship between height SDS and peak GH and a positive relationship between height SDS and IGF binding protein-3. This preliminary study therefore suggests that the IGF-I generation test in its present form will not be useful as a primary screening test for partial GH insensitivity. Despite this, the IGF-I generation test has been extremely useful in the confirmation of the diagnosis of GHIS and may therefore also prove useful in the confirmation of partial defects in the GH receptor. A subgroup of short children with peak GH levels above 40 mU/l had some characteristics of partial GH receptor deficiency. These children, to whom GH therapy would not normally be given, may respond better to recombinant human IGF-I.

Body Height↗
PubMed1991

[Late effects on the hypothalamo-pituitary function after the treatment of parasellar tumors].

Long term follow-up of patients submitted to treatment of parasellar tumours region is important for the detection of late therapeutic complications. In this study the authors conducted an evaluation of six patients with craniopharyngioma, one with germinoma, one with meningioma, and one epidermoid cyst. All above tumours were localized at parasellar region. Six out of nine patients had been treated both by surgery and by radiotherapy and the other three surgically only, on an average 3.8 +/- 3.2 years before this observation was carried out. Five patients were female with their ages average 24.3 +/- 18.8 years old. Evaluation consisted: in the first place, an intravenous infusion of thyrotropin-releasing hormone (TRH, 200 micrograms), gonadotropin-releasing hormone (GnRH, 100 micrograms), and insulin tolerance test (0.1 IU/Kg, regular insulin); and secondly, in measurements of pituitary hormones secretion at different time points--0, 20, 40, 60 and 80 minutes. We found both diminished response of growth hormone and cortisol in all the patients. Seven out of nine patients did not have adequate response to follicle-stimulating hormone. Three out of nine responded unsatisfactory to luteinizing hormone. Four out of nine showed inadequate responses to prolactin as well as, two out of eight to thyrotropin. We concluded that: (a) growth hormone and cortisol deficiency are the most frequent finding in these patients; (b) post-radiotherapy lesions can be located in the hypothalamus or pituitary, or even in both; (c) hypophysial and hypothalamic cells sensitivity to irradiation is different, according to their respective hormones; and (d) it is necessary a frequent endocrinologic follow-up of patients to detect late hormonal deficiencies.

Adolescent↗
PubMed1990

Radiographic and computed tomographic findings in hydatid disease of bone.

Twenty-six patients with hydatid disease of bone were evaluated by means of radiography and conventional tomography. Fourteen patients underwent high resolution computed tomography (CT). In two patients with vertebral disease, magnetic resonance imaging (MRI) examination was also performed. Seventeen patients underwent surgery with histological examination in all. Based on the surgical data and gross examination of the specimen, the radiographic and CT findings have been reviewed to identify the most characteristic radiographic features and to assess the role of CT. Radiographic finding of hydatidosis are rarely typical in bone, and only in a few patients can CT contribute to the diagnosis. On the other hand, the local extension of the lesion both in bone and in soft tissues, which is essential in planning surgery, is always demonstrated well by CT.

Adolescent↗
PubMed1987

CT diagnosis of lumbosacral conjoined nerve roots. Findings in 19 cases.

The authors report the observations derived from CT evaluation of 19 cases of lumbosacral conjoined nerve roots; 11 of these have been confirmed by lumbar myelography and/or at surgery. They conclude that CT without intrathecal metrizamide allows the recognition in most cases of the presence of conjoined nerve roots and to differentiate them from a herniated disk fragment; this is especially useful to avoid surgical damage of anomalous roots.

Adult↗
PubMed1987

Muscle CT, biopsy and EMG in diagnosis of neuromuscular diseases.

The diagnostic value of EMG and muscle biopsy has been compared with muscle CT in 53 patients with neuromuscular diseases. CT concordance with clinical diagnosis was found in 62% of myopathies and was highest in Duchenne PMD and scapulo-peroneal myopathy and very low in metabolic and inflammatory myopathies. In neurogenic diseases muscle CT agreed with clinical diagnosis in 63% of patients: the highest concordance was found in acquired polyneuropathies.

Biopsy↗
PubMed1987

[CT evaluation of sacrococcygeal chordoma].

From June 1985 to September 1986, eight patients affected by sacrococcygeal chordoma were examined by means of conventional radiography and tomography first, and then by high-resolution CT. All patients underwent surgery and an histologic examination of the surgical specimen was carried out. CT always allowed to detect the sacro-coccygeal neoplasm, which looked like a solid non-homogeneous mass; in 50% of cases coarse calcifications were found. CT made it possible to evaluate the growing side of the tumor, its relation with the adjacent anatomical structures-especially the longitudinal extension and the involvement of the sacral hiatus; these findings proved to be very useful in order to choose the most appropriate surgical technique. CT findings also suggested the nature of the tumor but rarely allowed a definitive diagnosis. CT is, at any rate, mandatory in order to evaluate the real extent of the tumor and to plan surgery.

Adult↗
PubMed1987

[Value and limitations of computerized tomography in the study of benign tumors of the bone].

In order to stress the role of CT in the evaluation of benign tumors of the bone the authors studied by means of a high-resolution CT scanner 74 patients that later underwent surgery (70 cases) and histological examination (all cases). CT findings were compared with the surgical and histological data. The results prove that the diagnostic contributions of CT are less important in the evaluation of benign than in malignant bone tumors. The major contributions of CT were:--the capability of detecting the presence of osteoid osteoma not found by means of conventional radiographic techniques;--differentiation between benign osteochondroma and peripheral chondrosarcoma by measurement of the peripheral cartilaginous cap: this criterion, on the other hand, does not seem to be always reliable and useful;--differential diagnosis of different types of cystic and fibrocystic diseases (simple and aneurysmal bone cyst, fibrous dysplasia);--evaluation of soft-tissue tumoral masses and of their extra-osseus extent in giant cell tumor and chondroblastoma; this allows us to establish the real extension of the tumor and to plan surgery more accurately.

Adolescent↗
PubMed1986

CT and the diagnosis of myopathies. Preliminary findings in 42 cases.

A total of 42 patients with myopathies underwent CT scans in order to study the relationship between CT images and clinical findings. CT is a valuable diagnostic aid to distinguish primary from neurogenic myopathies, to facilitate directed biopsy and finally to classify the disease according to the degree and extent of the muscular lesion.

Adolescent↗