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Biomedical subjects

A Migliore

Publications and source records attributed to A Migliore.

At least 19 recordsLinked to original sources
PubMed2006

First-principles density-functional theory calculations of electron-transfer rates in azurin dimers.

We have conceived and implemented a new method to calculate transfer integrals between molecular sites, which exploits few quantities derived from density-functional theory electronic structure computations and does not require the knowledge of the exact transition state coordinate. The method uses a complete multielectron scheme, thus including electronic relaxation effects. Moreover, it makes no use of empirical parameters. The computed electronic couplings can then be combined with estimates of the reorganization energy to evaluate electron-transfer rates that are measured in kinetic experiments: the latter are the basis to interpret electron-transfer mechanisms. We have applied our approach to the study of the electron self-exchange reaction of azurin, an electron-transfer protein belonging to the family of cupredoxins. The transfer integral estimates provided by the proposed method have been compared with those resulting from other computational techniques, from empirical models, and with available experimental data.

Algorithms↗
PubMed2003

A new mathematical model based on clinical and laboratory variables for the diagnosis of Sjögren's syndrome.

Sjögren's syndrome (SS) is a systemic autoimmune disease that mainly affects exocrine glands. A diagnosis of SS in its early stages has a potential clinical relevance, but it is difficult and cannot be made solely on clinical grounds. Several sets of diagnostic criteria have been proposed, but none has met with a general consensus. Minor salivary gland has been judged to be the "gold standard" for the diagnosis of SS. However, it is a painful procedure and has a small but significant proportion of both false positive and false negative results. The aim of our study was to develop a simple mathematical score that uses clinical and laboratory variables for diagnosing SS, thereby reducing the need of minor salivary gland. The following variables were included in the model: ANA, SS-A/SS-B, Schirmer's Test/BUT, C3/C4, serum gammaglobulin levels. One hundred consecutive individuals reporting clinical syndromes consistent with a sicca syndrome were included in the study. The application of our multifactorial mathematical model has shown a high predictive value for SS vs controls or vs patients with other autoimmune disorders (Sensitivity 93%, Specificity 100%), with an estimated minor salivary gland reduction of 77%. We conclude that our mathematical model can be considered a useful non-invasive approach for diagnosing Sjogren's Syndrome and recommend its validation on a larger scale.

Adult↗
PubMed2001

Isolated hemangioblastoma of the filum terminale. Case report.

The filum terminale is an exceptional location for isolated hemangioblastoma. Only five cases are reported in literature, prior to the magnetic resonance imaging era. A 57-year-old man was referred to our Department with a prolonged history of progressive back pain, particularly severe when recumbent, and recurrent unilateral sciatalgia. Computed tomography demonstrated a non-homogeneous mass at L4 level. Magnetic resonance imaging displayed earliness and homogeneous enhancement of the mass with tortuous vessels above the rostral pole of the tumour, suggesting the diagnosis of a vascular tumour. The tumour was totally removed. Histological examination confirmed the hemangioblastoma diagnosis. The case indicates that hemangioblastoma, although uncommon, must be taken into consideration in cauda equina tumour diagnosis, and also emphasises the specificity of magnetic resonance features.

Cauda Equina↗
PubMed1994

Acute intracerebral haemorrhage: circadian and circannual patterns of onset.

Hypothesis of the circannual and circadian variation in onset of intracerebral haemorrhage (CH) was verified, by means of single cosinor method and chi-square test for goodness of fit, in 161 consecutive patients (94 men and 67 women) admitted into the Institute of Neurosurgery of Ferrara Hospital, Italy, over 9 years. The majority of CH occurred in the morning between 06.00 AM and 12.00 noon (36.7% of cases, p < 0.001); when considering the specific anatomical sites, typical supratentorial haemorrhages showed a similar pattern (37.4%, p = 0.01). A similar morning behavior was found when considering subgroups by sex (men 36.2%, women 37.3%), age > or = 60 years (42.5%), no presence of hypertension (39.7%), no presence of diabetes mellitus (33.3%) and non-smokers (30.4%). The results by cosinor analysis yielded a circadian rhythmicity both for total sample and, for the men's subgroup, with a morning peak at 11.44 and 11.25, respectively. For women, however, spectral analysis found a significant ultradian cycle, having a period of 12 h (p = 0.01). A circannual periodicity, with a prevalent peak in February, was found for total sample and males subgroups, too. The results of this study confirm that intracerebral haemorrhages present a characteristic circadian and circannual pattern in onset.

Adult↗
PubMed1992

Intrinsic III ventricle craniopharyngioma.

A case of intrinsic III ventricle craniopharyngioma in an 11-year-old girl is presented. Only five cases in children have previously been reported in detail. The intraventricular location of a craniopharyngioma originates from ectopic remnants and causes intracranial hypertension without hormonal or neurological disorders. The tumor was safely removed by the transcallosal approach, and we confirmed that the floor of the III ventricle was intact.

Cerebral Ventricle Neoplasms↗
PubMed1992

Nicotinamide treatment in subjects at high risk of developing IDDM improves insulin secretion.

Nicotinamide (NCT) has been shown to be effective in preventing the onset of type 1 diabetes mellitus (IDDM) in mice with non-obese diabetic (NOD) and beta cell damage, mediated by the diabetogenic agents including streptozotocin. NCT therapy in man has been shown to have a beneficial effect on the remission phase of IDDM, and its use is safe. In this open pilot trial we therefore studied the effect of oral NCT administration on insulin secretion rate and islet-cell antibody (ICA) titres in IDDM high risk subjects. NCT (25 mg/10 kg bw) was administered in 6/13 high risk patients identified by a family screening programme. Those subjects tested after eight months without treatment showed a decreasing secretion in comparison to onset baseline (56,1 +/- 37.8 versus 35,5 +/- 12.2), whereas the treated subjects showed an increasing insulin secretion after treatment (26 +/- 10 versus 50.2 +/- 26.6), in spite of ICA persistence. Statistical analysis shows an increased insulin secretion in the treated group versus the untreated group (chi 2 = 3.899, P = 0.048). No side-effects were observed. We conclude that NCT may repair beta-cell function in high risk subjects too if damage is not too severe; furthermore, the effect seems not to be mediated by an immune mechanism.

Adolescent↗
PubMed1990

[Immunogenetic and functional study of first-degree relatives of patients with type I diabetes mellitus for identifying prediabetic subjects].

Insulin dependent diabetes mellitus is an autoimmune disease with HLA-related genetic susceptibility. There is a latent phase before overt disease. During this phase islet cell antibodies (ICA) as a marker of humoral autoimmunity are detected and i.v. glucose tolerance test (IVGTT) is decreased. The aim of our work was to correlate IVGTT, HLA typing and ICA testing in all siblings of IDDM patients in order to identify high risk subjects (HRS). IVGTT showed significantly lower insulin levels in siblings vs controls (P less than 0.0001). This phenomenon could be caused by HLA unrelated genetic predisposition to low insulin secretion. Insulin level values of ICA+ siblings were lower than those of ICA- siblings, even if the difference was not significant.

Autoantibodies↗
PubMed1988

Primary central nervous system lymphoma: a case of long survival.

Despite combined treatment (surgery, radio--and chemotherapy) primary central nervous system lymphoma (PCNSL) has generally a poor prognosis. Long surviving cases (more than 5 years) are exceptional. We report a case of a patient completely symptom-free 79 months after craniotomy. Histological diagnosis was diffuse centroblastic-centrocytic malignant lymphoma. Immunohistological study of the lesion was performed. Repeated CT scans reveal no tumor recurrence and screenings for extraneural disease remain negative. The prognostic value of tumor histology is emphasized.

Brain Neoplasms↗
PubMed1978

5-hydroxyindoleacetic acid (5-HIAA) levels in the cerebrospinal fluid of hydrocephalic children before and after ventricular shunting procedure.

21 cases of hypertensive hydrocephalus were investigated for lumbar 5-HIAA before and after operation. Seven groups (posterior fossa tumors) of patients aged between 2 and 12 years were tested after tumor removal; the others (nontumorous hydrocephalus) after ventricular shunting. This last group included 8 patients with noncommunicating hydrocephalus aged between 15 days and 12 years and 6 with communicating hydrocephalus aged between 6 months and 9 years. At the time of the second determination all patients presented an improvement of clinical signs of intracranial hypertension. A correlative analysis of 5-HIAA values before and after operation is made. In tumor cases, preoperative levels were higher than controls, and a significant decrease was found after operation in comparison with preoperative levels. In nontumor cases, a significant decrease was also observed in noncommunicating hydrocephalus, confirming clinical usefulness of the results for controlling the degree of the intracranial hypertension and, in consequence, shunt performance. In communicating cases the results were disappointing, because almost always postoperative levels did not differ from the preoperative ones. Possible interpretations of the data are analyzed.

Cerebrospinal Fluid Shunts↗
PubMed1977

[Aortoplasty with dacron patch in the surgical treatment of aortic coarctation].

The indications for aortoplasty and the techniques employed are described. The advantages of using Dacron patches are explained, namely: restricted mobilisation of the aorta, no sacrifice of intercostal vessels, no risk of haemorrhage from ectasic collateral vessels with weak walls, or from the calcified aorta wall, and simplicity. The method requires lengthwise section (extended as necessary) of the aorta where it is restricted following the application of clamps, removal of the stenosing diaphragm and application of a lozenge-shaped patch, with continuous suture of the anterior edges of the opening in the vessel. It is pointed out that the method is especially indicated in cases with marked atheromatous alterations and in chil-childrens, whose aorta is thereby enabled to grow normally, since a sufficient part of the wall is left in its natural continuity.

Adolescent↗
PubMed1975

[Disadvantages of mechanical valve prostheses in the surgical treatment of mitral insufficiency].

Various disadvantages may be encountered with mechanical valve prostheses in the surgical management of mitral insufficiency; namely: 1) Early and secondary disinsertion; this is nearly always partial and is usually accompanied by haemolytic anaemial. 2) Infection with nil response to antibiotics. Death from septicaemia may be rapid. Replacement of the prosthesis is otherwise mandatory. 3) Thrombosis, usually partial, accompanied by one or more embolisms. Thrombo-embolism is more frequently noted in the first 6 months after implantation and becomes less common as time passes. 4) Deterioration of the movable part (ball variance) consisting of changes in colour and shape, with swelling and unevenness of the surface, breakage, pitting and loss of elasticity. 5) Low stroke volume syndrome. 6) Erosion of the septum and serious rhythm disturbances. 7) Proliferation of endothelial tissue leading to narrowing of the orifice. 8) Disturbed movement of the movable part, leading to intermittent or permanent blockage and loss of opening or closing play due to the interposition of fibrin and blood clots.

Anemia, Hemolytic↗