Biomedical subjects

M Montani

Publications and source records attributed to M Montani.

8 recordsLinked to original sources

PubMed2006

IGFII and MIB1 immunohistochemistry is helpful for the differentiation of benign from malignant adrenocortical tumours.

AIMS: The differentiation of adrenocortical carcinomas from adenomas may be difficult based on morphology alone. Differential expression of insulin-like growth factor (IGF) II and cyclin-dependent kinase (CDK) 4 has recently been described in these tumours. The aim of this study was to investigate the diagnostic usefulness of these markers immunohistochemically. METHODS AND RESULTS: We examined 22 benign and 17 malignant adrenocortical tumours and compared IGFII and CDK4 expression with known immunohistochemical as well as morphological criteria of malignancy. Thirteen of 17 carcinomas showed immunohistochemical reactivity for IGFII, whereas all adenomas but one were negative. Intense CDK4 expression was detected in 11 of 17 carcinomas but was present in only three of 22 adenomas. The MIB1 index was >5% in 14 of 16 carcinomas and was <5% in all adenomas but one. The combination of IGFII immunohistochemistry with MIB1 index led to high sensitivity and specificity in detecting adrenocortical carcinomas. CONCLUSIONS: IGFII and MIB1 are helpful immunohistochemical markers to predict malignancy in adrenocortical neoplasms. These markers can be used in addition to clinical, gross and morphological features to establish a diagnosis in difficult cases.

Adrenal Cortex Neoplasms↗

PubMed2005

No mutations but an increased frequency of SDHx polymorphisms in patients with sporadic and familial medullary thyroid carcinoma.

Germline mutations of the three succinate dehydrogenase subunits SDHB, SDHC and SDHD have recently been associated with familial pheochromocytoma and paraganglioma. Several reasons make these genes candidate tumor suppressor genes for medullary thyroid carcinoma (MTC): (1) SDHB lies on chromosome 1p, the region known to be deleted most frequently in MTC, (2) MTCs develop from neural crest-derived cells, as do pheochromocytomas and paragangliomas and (3) patients with germline mutations of the Ret-protooncogene develop MTCs as well as pheochromocytomas, indicating a relationship of these tumors on a genetic level. Therefore, we attempted to determine whether the tumor suppressor genes SDHB, SDHC and SDHD are involved in sporadic and familial MTC. Somatic mutations of the SDH subunits were absent in all 35 investigated MTCs. Loss of heterozygosity was found in 27% (SDHB) and 4% (SDHD) respectively. While the frequency of non-coding, intronic polymorphisms did not differ in MTC patients compared with a control population, an accumulation of amino-acid coding polymorphisms (S163P in SDHB as well as G12S and H50R in SDHD) was found among MTC patients especially patients with familial tumors, suggesting a functional connection of coding SDH polymorphisms to activating Ret mutations.

Adult↗

PubMed2001

Intelligent knowledge retrieval for decision support in medical applications.

Knowledge management and retrieval are key issues to be addressed in the medical domain, where a large amount of information is generally available, and where the expert's skills need to be properly shared across the organisation, with the aim of improving the quality of care. Case Based Reasoning (CBR) is a very well suited methodology for the Knowledge Management task, when knowledge is in the operative form. Nevertheless, also well-assessed, formalised medical knowledge, such as clinical guidelines, should be made available to physicians in order to optimise their reasoning process. To take advantage of both knowledge types, we have defined a Multi Modal Reasoning methodology, that integrates CBR and Rule Based Reasoning, for supporting context detection, information retrieval and therapy revision in diabetes care.

Artificial Intelligence↗

PubMed1997

Electrokinesiologic measurement of trunk sagittal mobility and lumbar erector spinae muscle activity.

Additional studies to determine intratester reliability of electrokinesiologic (EK) measures related to trunk movement and low back muscle activity are needed. EMG activity and EK records of repetitive movements at both natural and maximal speeds were computer sampled and quantified among 22 nonimpaired subjects. Significant differences were observed between group means at different speeds and trials for both kinematic and EMG measures. Predictably, maximal speed testing resulted in higher levels of EMG activity when compared to natural speed testing. Intratester reliability of measures was high at both speeds. Range of motion data correlated well between two trials for both natural and maximal speed movements, ranging from 0.81 to 0.97. Correlation of speed of movement measures ranged from 0.41 to 0.76. These data suggest that computer-analyzed EMG activity and EK signals are reliable assessment tools for trunk mobility. The application of this procedure to persons with low back pain to acquire EMG activity and mobility data appears justified.

Adolescent↗

PubMed1996

Fractal analysis: a new method for evaluating fetal heart rate variability.

In this report we describe how the technique of "deterministic chaos" can be successfully applied to the study of fetal cardiotocography (CTG). The CTG tracings were analysed, after identification as "normal" or "pathological" by experts and by a computerised system, to evaluate the correlation dimension (D2), and the graphic analysis of the attractors which visualize the phase-space of the system that generated the signal (of the state of the underlying hypothetical system). Thanks to this analysis of the traces, it is possible to detect the existence of chaos in the system that generates a certain signal in this case the fetal heart rate. Normal CTG traces at term (37-41 wks) show a fractal dimension (D2) index ranging from 4.22 to 5.22; highly pathological CTG tracings show a D2 ranging from 2.0 to 3.09. Moreover, we introduced recurrence plots in the study of CTG, as tool for non stationary signals, working in real time. To our knowledge this is one of the first attempts to apply fractal analysis and recurrence plots in the evaluation of fetal heart rate in pregnancy, using very small data sets.

Cardiotocography↗

PubMed1992

Case report: autonomic postganglionic denervation--sural nerve and saphenous vein biopsy.

The authors describe a 31-year-old woman of British Isle ancestry who developed a syndrome resembling familial dysautonomia in her early teenage years. Predominant manifestations included achalasia, severe orthostatic hypotension, and abnormal sweating. The study included resting and stimulated fractional catecholamines, which were almost nonexistent in both situations, and urinary catecholamines, demonstrating an increase in dopamine degradation products. Immunohistochemistry of saphenous vein was negative for dopamine beta-hydroxylase (DBH), serotonin (5-HT) and several vasoactive neuropeptides. The only neuropeptide detected at levels thought to be physiologically relevant was calcitonin gene-related peptide (CGRP), a vasodilator. This was in contrast to control veins, all of which had DBH and neuropeptide Y immunoreactive fibers but few CGRP fibers. Also in contrast to controls, electron microscopy of the saphenous vein indicated a close to total absence of terminals with norepinephrine containing vesicles. Sural nerve biopsy showed, on electron microscopy, a considerable reduction in the number of myelinated fibers, while unmyelinated fibers appeared to be in the normal range. The authors suggest, from the above findings, that the autonomic fibers were undergoing some form of distal axonal degeneration. Their findings differ from most biopsies performed in dysautonomic children, and they believe their patient has a different neurologic entity.

Adult↗

PubMed1988

Temperature influence on Penicillium citrinum thom growth and citrinin accumulation kinetics.

To study the temperature influence on both Penicillium citrinum growth and citrinin accumulation, a 20, 25 and 30 degrees C. Radial and 30 degrees C. Radial growth rate and lag phase were determined from the increase in colony diameter with time. The optimal temperature for P. citrinum growth was 30 degrees C. Citrinin extracted from the agar medium was determined by thin layer chromatography. Citrinin accumulation kinetics were analyzed by fitting the data to curves generated by using a logistic function. The parameters obtained from this equation demonstrated, for all temperatures studied, that the maximum citrinin accumulation by P. citrinum on Czapek agar with maize extract was at about 30 degrees C. At 37 degrees C a rapid decrease in the citrinin concentration was observed after a maximal value was reached.

Agar↗

PubMed1983

Platelet release reaction and prostaglandin pathway activation in angina patients during exercise: effect of indobufen.

Platelet 14C-serotonin release induced by collagen, and platelet malondialdehyde (M.D.A.) generation induced by thrombin were assessed in twenty patients with stable angina, before and after exercise with a bicycle ergometer. The patients received a single oral 200 mg dose of indobufen or placebo according to a crossover design in double-blind conditions. The M.D.A. concentration increased when exercise was carried out after placebo, whereas indobufen markedly inhibited M.D.A. production and 14C-serotonin release. These results suggest that effort may be an important factor in activation of the platelet prostaglandin pathway and that the use of antithrombotic drugs may be appropriate in patients with angina.

Adult↗