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M Marchi

Publications and source records attributed to M Marchi.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Deglutition in patients treated with reconstructive laryngectomy].

INTRODUCTION: We stress the importance of dynamic radiologic studies of swallowing in the patients submitted to reconstructive laryngectomy. MATERIAL AND METHODS: January, 1989, to December, 1996, we examined 36 patients submitted to reconstructive laryngectomy, namely cricohyoidoepiglottopexy in 34 cases, cricohyoidopexy in 1 case and Guerrier's cricohyoidoepiglottopexy in 1 case. Dynamic radiologic studies were performed with fluoroscopic videorecording (Sony U-Matic RM 580) from an X-ray unit. The study was performed with the patients standing or sitting, initially acquiring AP and LL fluoroscopic images of the oropharyngeal region at rest and during swallowing. The patients then swallowed 2 boluses of 5 ml liquid (60%) and semiliquid (250%) barium. When aspiration was suspected, we began with a 2-ml bolus. RESULTS: The patients were grouped by symptoms: group A patients had no symptoms, group B patients had dysphagia and group C patients presented aspiration. The functional changes were: reduced pharyngeal contraction, reduced epiglottis deflection, reduced hyoid bone elevation, aspiration, altered upper esophageal sphincter function. The organic alterations were: parapharyngeal diverticulum, pharyngeal stenosis, posterior pharyngeal wall introflexion. Three group A patients had severe posterior pharyngeal wall introflexion, 4 had marked retention and 2 of them presented postswallowing aspiration. Two group B patients had major retention, 1 cricopharyngeal incoordination, 3 posterior pharyngeal wall introflexion, 2 a pseudodiverticulum and 2 a luminal stenosis. Seven group C patients had intraswallowing and 3 postswallowing aspiration. CONCLUSION: The videofluorographic identification of organic and functional complications, sometimes unknown in asymptomatic patients, is useful for therapy and suggests the speech specialist the best compensatory mechanism to improve the patients' swallowing and consequently their quality of life. Moreover, videofluorography of swallowing is a very useful tool in the follow-up, to monitor treatment outcome after rehabilitation.

Deglutition↗
PubMed1997

Haemangioma of the zygoma: case report.

Haemangioma of bone in the zygoma is extremely rare. We report two cases presenting with swelling of the zygomatic region. The literature is reviewed and CT, angiographic and MRI findings are discussed.

Adult↗
PubMed1996

Intrinsic compressibility and volume compression in solvated proteins by molecular dynamics simulation at high pressure.

Constant pressure and temperature molecular dynamics techniques have been employed to investigate the changes in structure and volumes of two globular proteins, superoxide dismutase and lysozyme, under pressure. Compression (the relative changes in the proteins' volumes), computed with the Voronoi technique, is closely related with the so-called protein intrinsic compressibility, estimated by sound velocity measurements. In particular, compression computed with Voronoi volumes predicts, in agreement with experimental estimates, a negative bound water contribution to the apparent protein compression. While the use of van der Waals and molecular volumes underestimates the intrinsic compressibilities of proteins, Voronoi volumes produce results closer to experimental estimates. Remarkably, for two globular proteins of very different secondary structures, we compute identical (within statistical error) protein intrinsic compressions, as predicted by recent experimental studies. Changes in the protein interatomic distances under compression are also investigated. It is found that, on average, short distances compress less than longer ones. This nonuniform contraction underlines the peculiar nature of the structural changes due to pressure in contrast with temperature effects, which instead produce spatially uniform changes in proteins. The structural effects observed in the simulations at high pressure can explain protein compressibility measurements carried out by fluorimetric and hole burning techniques. Finally, the calculation of the proteins static structure factor shows significant shifts in the peaks at short wavenumber as pressure changes. These effects might provide an alternative way to obtain information concerning compressibilities of selected protein regions.

Muramidase↗
PubMed1996

Role of external and internal calcium on heterocarrier-mediated transmitter release.

Release-regulating heterocarriers exist on brain nerve endings. We have investigated in this study the mechanisms involved in the neurotransmitter release evoked by GABA heterocarrier activation. GABA increased the basal release of [3H]acetylcholine and [3H]noradrenaline from rat hippocampal synaptosomes and of [3H]dopamine from striatal synaptosomes. These GABA effects, insensitive to GABA receptor antagonists, were prevented by inhibiting GABA uptake but not by blocking noradrenaline, choline, or dopamine transport. Lack of extracellular Ca2+ or addition of tetrodotoxin selectively abolished the GABA-evoked release of [3H]noradrenaline, leaving unaffected that of [3H]acetylcholine or [3H]dopamine. 1,2-Bis(2-aminophenoxyl)-ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM) or vesamicol attenuated the release of [3H]acetylcholine elicited by GABA. Reserpine, but not BAPTA-AM, prevented the effect of GABA on [3H] dopamine release. Autoreceptor activation inhibited the GABA-evoked release of [3H]noradrenaline but not that of [3H]acetylcholine or [3H]dopamine. It is concluded that (a) the release of [3H]noradrenaline consequent to activation of GABA heterocarriers sited on noradrenergic terminals meets the criteria of a conventional exocytotic process, (b) the extracellular [Ca2+]-independent releases of [3H]acetylcholine and [3H]dopamine appear to occur from vesicles possibly through involvement of intraterminal Ca2+, and (c) autoreceptor activation only affects heterocarrier-mediated vesicular release linked to entry of extracellular Ca2+.

Acetylcholine↗
PubMed1996

Nicotinic autoreceptors mediating enhancement of acetylcholine release become operative in conditions of "impaired" cholinergic presynaptic function.

The existence in the mammalian CNS of release-inhibiting muscarinic autoreceptors is well established. In contrast, few reports have focused on nicotinic autoreceptors mediating enhancement of acetylcholine (ACh) release. Moreover, it is unclear under what conditions the function of one type of autoreceptor prevails over that of the other. Rat cerebrocortex slices, prelabeled with [3H]choline, were stimulated electrically at 3 or 0.1 Hz. The release of [3H]ACh evoked at both frequencies was inhibited by oxotremorine, a muscarinic receptor agonist, and stimulated by atropine, a muscarinic antagonist. Nicotine, ineffective at 3 Hz, enhanced [3H]ACh release at 0.1 Hz; mecamylamine, a nicotinic antagonist, had no effect at 3 Hz but inhibited [3H]ACh release at 0.1 Hz. The cholinesterase inhibitor neostigmine decreased [3H]ACh release at 3 Hz but not at 0.1 Hz; in the presence of atropine, neostigmine potentiated [3H]ACh release, an effect blocked by mecamylamine. In synaptosomes depolarized with 15 mM KCl, ACh inhibited [3H]ACh release; this inhibition was reversed to an enhancement when the external [Ca2+] was lowered. The same occurred when, at 1.2 mM Ca2+, external [K+] was decreased. Oxotremorine still inhibited [3H]ACh release at 0.1 mM Ca2+. When muscarinic receptors were inactivated with atropine, the K+ (15 mM)-evoked release of [3H]ACh (at 0.1 mM Ca2+) was potently enhanced by ACh acting at nicotinic receptors (EC50 approximately 0.6 microM). In conclusion, synaptic ACh concentration does not seem to determine whether muscarinic or nicotinic autoreceptors are activated. Although muscarinic autoreceptors prevail under normal conditions, nicotinic autoreceptors appear to become responsive to endogenous ACh and to exogenous nicotinic agents under conditions mimicking impairment of ACh release. Our data may explain in part the reported efficacy of cholinesterase inhibitors (and nicotinic agonists) in Alzheimer's disease.

Acetylcholine↗
PubMed1995

Effects of an acute increase in plasma triglyceride levels on glucose metabolism in man.

The aim of the study was to evaluate the effects of an acute increase in triglyceride levels induced by Intralipid (Kabivitrum, Stockholm, Sweden) infusion on forearm glucose uptake, glucose oxidative metabolism, and hepatic glucose production independent of circulating free fatty acid (FFA) levels in man. Six normal subjects underwent three different tests in random order. Each test consisted of a control period of 120 minutes followed by a euglycemic, hyperinsulinemic clamp lasting 120 minutes. In test 1, a high-dose intravenous Intralipid infusion was performed to increase triglyceride and FFA levels. In test 2, heparin (30 U/min) plus low-dose Intralipid infusions were performed to maintain triglyceride at normal levels and increase only FFA levels. Test 3 was performed as a control study. During the 120-minute control period, forearm glucose uptake and hepatic glucose production were not affected by increasing only FFA levels (test 2) or FFA and triglyceride levels (test 1) as compared with the control study. On the contrary, glucose oxidation was significantly decreased as compared with the control study during tests 1 and 2, without a further significant decrease during simultaneously increased FFA and triglyceride levels. Concomitantly, lipid oxidation was similar in tests 1 and 2, at values significantly greater than in test 3. During the euglycemic clamp, forearm glucose uptake and glucose oxidation were significantly lower during tests 1 and 2 than test 3. At variance with the control period, the increase of triglyceride levels during test 1 caused a significant 30% to 40% decrease of both parameters as compared with test 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Lateral thigh free flap in head and neck reconstruction.

To understand the role of the lateral thigh flap in head and neck reconstruction, we performed injection studies and anatomic dissections in 2 fresh and 61 preserved cadaver extremities followed by 10 clinical cases involving defects after tumor ablation. The flap, based on the third perforator of the profunda femoris artery, is designed on the posterolateral aspect of the distal thigh. The pedicle courses through the biceps short head, allowing optional transfer of this muscle. Defects of the oral cavity, pharynx, cervical esophagus, and external skin were successfully restored. One flap was unsuccessful because of intraoperative injury to the vascular pedicle. Compared with the radial forearm flap, the lateral thigh flap provides more tissue and the donor scar is more easily hidden, but the vascular pedicle is shorter, of smaller caliber, and more variable. The lateral thigh flap provides thin, pliable, and reliable tissue for a variety of needs in properly selected patients.

Adult↗
PubMed1995

[Time series analysis in environmental epidemiology: short-term effects of air pollution on mortality and morbidity].

This work gives an overview of design and analysis of temporal studies using aggregated data in air pollution epidemiology. In the last years time series are often used to study the short-term association between ambient air pollution levels and aggregated health data. Health endpoints are usually daily mortality and/or daily hospital admission data from routine health registers. Air quality data are commonly obtained from one (or a few) fixed site monitoring stations. To detect the temporal association between the time-pattern in air pollution and the time-pattern in health data particular attention needs to be given to the autocorrelation structure, to the seasonality and long term trend in the data, and to the weather variables. Poisson regression with autocorrelated residuals is the suitable statistical method to analyze time studies. Furthermore, the pollutant variable can be analyzed at different lag-times to account for short latency periods in the manifestation of diseases. Studies with temporal aggregated data show the same disadvantages of the ecologic studies, although, in this case, confounding is less of a problem. Temporal studies usually are based on a large database, so that sufficient power can be achieved to detect even weak associations. Finally, the exposure information on subjects is often better characterized by short-term fluctuations in ambient air quality than is the case in geographic aggregations.

Air Pollutants↗
PubMed1995

[A critical review of epidemiological methods for spatial analysis].

Since the 1950's a number of methods have been developed whose aims is to provide enhanced mapping tools, which allow the depiction of the distribution of disease, and thereafter, to assess risks due to environmental factors (or other spatial-defined factors). Our review of statistical-epidemiological methodology for spatial analysis of diseases shall outline the distinction between global tests for clustering (detection of non casual distribution of events in an area) and cluster detection's techniques for the identification and location of abnormal aggregation of disease's cases. In this paper we evaluate each-one of the proposed methods, on general grounds, with regard to whether they meet the aims of the analysis and how successful they are in overcoming problems.

Epidemiologic Methods↗
PubMed1994

Brain stem and motor evoked responses in "locked-in" syndrome.

A patient suffering for an ischemic "locked-in" syndrome following a subarachnoid hemorrhage, was evaluated with brain stem acoustic evoked potentials (BAEPs), short latency somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs). Neuroradiological findings failed to reveal any lesion in the brain stem, while a transcranial Doppler showed increased flow velocity upon the basilar artery, suggesting vascular spasm. BAEPs were normal and SEPs showed to be slightly impaired while MEPs upon magnetic cortical stimulation were heavily deranged. Neurophysiological investigations appeared remarkable for the early diagnosis of the disease, when neuro-radiological findings were still negative.

Adult↗
PubMed1994

A single center's experience with 308 free flaps for repair of head and neck cancer defects.

Since its inception at our institution in 1988, microvascular reconstructive surgery has become an integral part of the treatment of head and neck cancer patients. This review of 308 free flaps performed over the last 4 years was done to evaluate the complication and flap loss rates and to investigate which factors may contribute to these rates. The overall complication rate was 36.1 percent, the vessel thrombosis rate was 6.8 percent, the flap loss rate was 5.5 percent, and the flap salvage rate was 19.0 percent. Multifactorial analysis of delayed reconstruction, tobacco use, alcohol consumption, previous radiation therapy, previous surgery, and use of vein grafts showed that only previous surgery and the use of vein grafts led to significantly higher rates of flap loss (p < 0.01 for both).

Adolescent↗
PubMed1994

[Percutaneous computed tomography-guided biopsy in spinal diseases].

The use of percutaneous spinal biopsy (PSB) is on the increase in the field of interventional radiology. From July 1990 to December 1992 in the Department of Radiology in the Istituto Ortopedico Rizzoli, 74 patients (50 men and 24 women, mean age: 47 years old) underwent CT-guided spinal biopsy. This study was aimed at evaluating the diagnostic capabilities and accuracy of CT-guided percutaneous biopsy, which is considered as a simple, reliable and definitive method for histopathologic diagnosis. In our case histories, the total average accuracy rate, which varies according to the involved segment and to the kind of lesion to be examined, was 86%; in 14% of cases the excised tissue proved insufficient for histologic diagnosis. By allowing the histopathologic diagnosis to be made, CT-guided PSB proves a valuable technique to plan the treatment of primary/secondary neoplastic lesions or of inflammatory and dysmetabolic processes.

Biopsy, Needle↗
PubMed1994

[Azithromycin-omeprazole. Treatment for the eradication of Helicobacter pylori].

AIM: To evaluate the benefit of 4-week regimen including azithromycin+omeprazole (vs omeprazole alone) for eradication of Helicobacter pylori. METHODS: Twenty HP positive patients with an ulcer dyspepsia (NUD) were included in this study. They were given either omeprazole 40 mg for 4 weeks alone or in combination with azithromycin 1 g/die for 1 week. Endoscopy was performed before 4 weeks after and 4 months after treatment. The presence of HP was assessed in antral and corporeal biopsies by urease test and histology. RESULTS: HP eradication was observed in 9/10 (90%) patients in the omeprazole+azithromycin group and 0/10 patients in the omeprazole alone group. CONCLUSION: Omeprazole 40 mg for 4 weeks in combination with azithromycin 1 g die for 1 week eradicates HP in 90% of these patients. The good eradication percentage and absence of collateral effect make us extend patients' number to test.

Adult↗
PubMed1993

A method for optimizing skin graft healing and outcome of wounds of the penile shaft and scrotum.

Split-thickness skin grafting provides the best functional and aesthetic result in the treatment of wounds of the penis and scrotum. Achieving graft adherence and take in this anatomically mobile region is challenging. A simple method of effectively stabilizing skin grafts in the treatment of penile and perineal wounds is described, and patients in whom complete graft take was achieved are discussed.

Bandages↗