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Biomedical subjects

M Manfredi

Publications and source records attributed to M Manfredi.

At least 73 records · Page 4Linked to original sources
PubMed2000

Trigeminal small-fibre dysfunction in patients with diabetes mellitus: a study with laser evoked potentials and corneal reflex.

OBJECTIVE: To investigate trigeminal small-fibre function in patients with diabetes mellitus. METHODS: In 52 diabetic patients we studied the trigeminal laser evoked potentials after stimulation of the skin bordering the lower lip. In the 21 patients with the severest peripheral nerve damage we also studied the electrically evoked corneal reflex. Both responses are mediated by small myelinated afferents. RESULTS: Laser evoked potentials had a longer mean latency and lower amplitude in diabetic patients than in normal subjects (P<0.005). The abnormality frequency of the laser evoked potentials correlated with the severity of polyneuropathy (P<0.005). In contrast, the corneal reflex was normal. CONCLUSION: Dysfunction of small afferents of the mandibular nerve is frequent in patients with diabetic polyneuropathy. We speculate that the primary cause could be segmental demyelination.

Adult↗
PubMed2000

Dysfunction of small myelinated afferents in diabetic polyneuropathy, as assessed by laser evoked potentials.

OBJECTIVE: To verify whether laser evoked potentials are useful in assessing the function of small afferent fibers and to compare dysfunction of large and small afferent fibers in patients with diabetic polyneuropathy. METHODS: The brain potentials evoked by CO2 laser stimulation of the hand and foot were studied in diabetic patients (n = 45) with various degrees of peripheral nerve damage. Laser evoked potentials (which assess the function of small myelinated afferents) were also compared with ulnar and sural nerve sensory action potentials (which assess the function of large myelinated afferents) by scoring the abnormalities of the two neurophysiological tests with similar criteria. RESULTS: Laser evoked potentials were often absent; the mean latency was normal and mean amplitude decreased, as expected in axonopathies. Although clinical examination showed more frequent impairment of vibratory than pinprick sensation, laser evoked potentials and sensory action potentials yielded similar abnormality scores and showed a strong intra-individual correlation. CONCLUSIONS: Laser evoked potentials, possibly better than standard clinical examination for assessing the abnormalities of small-diameter afferents, indicate that diabetic polyneuropathy induces large- and small-afferent dysfunction in parallel.

Brain↗
PubMed2000

New onset atrial flutter termination by overdrive transoesophageal pacing: effects of different protocols of stimulation.

AIM: We evaluated the effect of different stimulation protocols on atrial flutter interruption by transoesophageal pacing. METHODS AND RESULTS: Eighty patients with new onset atrial flutter were randomized into four groups. Pacing was attempted under the following conditions: with short bursts (5 s), without treatment (group A) and after oral administration of propafenone 600 mg (group B); with prolonged bursts (30 s), without treatment (group C) and after oral administration of propafenone 600 mg (group D). Pacing interrupted atrial flutter in 20% of patients in A, 55% in B, 50% in C and 85% in D. The use of longer bursts gave better results both in patients without treatment (P < 0.05: C vs A) and in patients with propafenone (P < 0.05: D vs B). Comparing groups with the same stimulation protocol, we observed a better response in patients treated with propafenone (P < 0.05: B vs A and D vs C). In the groups without treatment the use of shorter bursts was associated with a lower induction of stable atrial fibrillation (three vs nine episodes), in the groups on propafenone no differences were observed (one vs one episode). CONCLUSIONS: We conclude that the association of propafenone with long bursts gives the best result for interruption of new onset atrial flutter by transoesophageal pacing.

Administration, Oral↗
PubMed2000

A mathematic-geometric model to calculate variation in mandibular arch form.

A mathematic-geometric model was used to evaluate the variation of mandibular dental arch length with respect to the incisor inclination, but without modifying the intercanine width. In analytical terms, the equations of the curves representing the lower dental arch, before and after incisor inclination of 1 mm and of 1 degree, with controlled and uncontrolled tipping, were studied. The length of the mandibular dental arch changed in the parabolic arch form by 1.51 mm for each millimetre of incisor inclination with respect to the occlusal functional plane, by 0.54 mm for each degree of controlled tipping and by 0.43 mm for each degree of uncontrolled tipping. In the elliptical arch form (e = 0.78), it changed by 1.21, 0.43, and 0.34 mm, respectively, in the hyperbolic form by 1.61, 0.57, and 0.46 mm, in the circular form by 1.21, 0.43, and 0.34 mm, and in the catenary form by 2.07, 0.74, and 0.59 mm. The results show that by changing the arch form without modifying the dimension of the dental arch, different arch lengths can be gained for each millimetre of proclination. In addition, by controlled tipping an inter-incisive arch one-fifth longer than by uncontrolled tipping can be obtained. It would be advisable in orthodontic treatment planning to evaluate the type of dental arch, since the space available or the space required changes depending on the arch form and on the orthodontic tooth movement.

Algorithms↗
PubMed2000

Effects of botulinum toxin type A on intracortical inhibition in patients with dystonia.

To find out whether botulinum toxin alters the excitability of cortical motor areas, we studied intracortical inhibition with transcranial magnetic stimulation in patients with upper limb dystonia before, 1 month after, and 3 months after the injection of botulinum toxin type A in the affected muscles. Eleven normal subjects and 12 patients with dystonia involving the upper limbs (7 with generalized dystonia, 2 with segmental dystonia, and 3 with focal dystonia) were studied. Patients were assessed clinically with the Dystonia Movement Scale. Paired magnetic stimuli were delivered by two Magstim 200 magnetic stimulators connected through a Bistim module to a figure-of-eight coil placed over the motor area of the forearm muscles. Paired stimulation was given at rest. A subthreshold (80% of motor threshold) conditioning stimulus was delivered 3 and 5 msec before the suprathreshold (120% of motor threshold) test stimulus. Electromyographic signals were recorded over the flexor or extensor muscles of the forearm on the affected side. We measured the amplitude of the test motor evoked potential (expressed as a percentage of the unconditioned motor evoked potential). All results were compared using ANOVA. In all patients, a botulinum toxin type A injection (50-100 mouse units) reduced dystonic movements in the arm. In normal subjects, electromyographic recordings showed significant inhibition of the test response. Before botulinum toxin injection, patients had less test response inhibition than normal subjects. One month after injection, patients had test response inhibition similar to that of normal subjects. At 3 months after injection, they again had less inhibition than normal subjects or patients at 1 month after injection. In conclusion, our data suggest that botulinum toxin can transiently alter the excitability of the cortical motor areas by reorganizing the inhibitory and excitatory intracortical circuits. The cortical changes probably originate through peripheral mechanisms.

Adult↗
PubMed2000

[Burning mouth syndrome. Clinical experience with 75 patients].

The burning mouth syndrome (BMS) is a very common disorder frequently seen in practical dentistry. It is a particular condition with a complex of strange burning sensation localized in the oral mucosa which is clinically normal. It is very important for the dentist to recognize and classify this particular syndrome in order to exclude other factors which can cause the same symptoms. On the basis of personal experience on 75 patients, the complex management of this particular group of patients has been evaluated to make a right diagnosis and a correct treatment.

Burning Mouth Syndrome↗
PubMed2000

[Neoplastic transformation of oral lichen planus. I: Review of the literature].

Lichen planus is described like a well-characterized dermatological condition affecting the skin and the oral and genital mucosa. Over the years, different authors have expressed the possible oral lichen planus premalignant nature, but this is still controversial. This criticism is due to the insufficiency of the clinical and histopathological data to support the initial diagnosis of oral lichen planus, the occurrence of some wrong diagnostic criteria for this pathology, the contemporary presence in the same region of the oral lichen planus lesions and of neoplasia. The malignant transformation of oral lichen planus rate varies, according to authors, from 0.4 to 3.7%. The aim of this study is to review the literature from 1910 to 1999, focusing on the suggested possible premalignant nature of oral lichen planus.

Humans↗
PubMed2000

[Neoplastic transformation of oral lichen planus. II: association with risk co-factors].

The possible malignant transformation of oral lichen planus is still controversial. It is not clear if this is in fact due to the premalignant nature of oral lichen planus or to the presence of some risk-factors in patients with this pathology. The risk co-factors that may he involved in this malignant transformation are numerous. Some authors suggested a correlation between oral lichen planus and HCV or HGV, or with the presence of some oncogenic viruses (EBV, HSV, HPV). Cases of this malignant transformation on oral and genital mucosa with lichen are reported, hut none on the skin lesions. The aim of this study is to investigate, through the literature, these correlations that may have a role in the malignant transformation of oral lichen planus.

Humans↗
PubMed2000

[Digestive endoscopy in children].

Also in the pediatric population the digestive endoscopy became, at this point, a very good diagnostic and operative technique largement used. The endoscopy can explore the upper gastrointestinal tract (esophagus, stomach, duodenum and jejunum) and can investigate the colon and the terminal ileum regarding the lower gastrointestinal tract. Principally, the operative endoscopy concerns emostasis of gastrointestinal bleeding, polipectomy, extraction of foreign bodies, and intestinal dilatations. The patients population submitted to this investigation by now is very wide thanks to the modernization of the instruments and at specialization of gastroenterologist pediatricians: range from newborn, to childhood, adolescence and young adults. The gastroenterologist pediatricians specialization associated to a routine use of amnemonic drugs (benzodiazepine) reduced at the minimum the invasivity of endoscopy; this technique can be considered a good safe procedure and free of important physical and psychic side effects for the young patient.

Child↗
PubMed2000

[Digestive endoscopy in neonates. Personal experience].

Gastrointestinal (GI) endoscopy is actually considered an essential diagnostic and therapeutic technique both in pediatrician and in newborn infants. At the moment upper GI endoscopy in neonatal age allows to explore the esophagus, stomach and duodenum; instead lower GI endoscopy easily reaches sigmoid-colon junction. The exploration of other distal parts of bowel is more difficult and with more risks. Therefore it has to be make only if it is necessary. In the newborn this exam should be so fast not to require premedication. In our study, we considered every neonatal patient who underwent GI endoscopy at the "Digestive Endoscopy and Gastroenterology Service of Pediatric Clinic-University of Parma" (from September 1983 to June 2000). We considered two groups of patients: first group: early neonatal age (0-14 days) second group: late neonatal age (15-28 days). We made 127 endoscopies: 112 of these were upper GI. The most frequent symptoms that babies showed and indicated upper GI endoscopy were reflux and/or vomiting (86%). Upper operative GI endoscopies included also 7 esophageal dilatations. The lower GI endoscopies were 15 and in all the cases the indication was intestinal bleeding. We conclude that the GI endoscopy in the neonates shows a diagnostic sensibility and specificity really high and for sure better than the radiology for mucosal lesions. Also GI endoscopy can be not only a very precious diagnostic instrument but also therapeutic in neonatal disease. Considering the age of the little patients, it is very important that only endoscopists with large experience use this technique.

Age Factors↗
PubMed1999

Highly Th2-skewed cytokine profile of beta-lactam-specific T cells from nonatopic subjects with adverse drug reactions.

A positive lymphocyte transformation test to beta-lactams (beta-L) was found in 12 of 29 subjects with adverse drug reaction (ADR) to beta-L, irrespective of either the type of clinical manifestation or the presence of specific serum IgE. Short-term T cell lines specific for penicillin G, amoxicillin, and ampicillin could be generated only from subjects with ADR (eight with positive and one with negative lymphocyte transformation test), while streptokinase and Dermatophagoides pteronyssinus group 1 (Der p 1)-specific T cells were obtained from all these subjects, from 7 atopic Der p-sensitive donors without history of ADR and 17 healthy nonatopic donors. Streptokinase-specific T cells from all subjects showed intracellular expression of IFN-gamma with poor or no IL-4, whereas Der p 1-specific T cells exhibited IFN-gamma but low or no IL-4 expression in nonatopics, and remarkable IL-4 expression in atopic donors. By contrast, all penicillin G-, ampicillin-, and amoxicillin-specific short-term T cell lines showed high intracellular expression of IL-4, IL-5, and IL-13, but poor or no expression of IFN-gamma, thus exhibiting a clear-cut Th2 profile. Accordingly, most penicillin G-specific T cell clones derived from two subjects with ADR released high concentrations of IL-4 alone or IL-4 and IFN-gamma. These data suggest that cytokines produced by Th2 cells play an important role in all beta-L-induced ADR, even when late clinical manifestations occur and an IgE-mediated mechanism is apparently indemonstrable.

Allergens↗
PubMed1999

Assessment of trigeminal small-fiber function: brain and reflex responses evoked by CO2-laser stimulation.

Laser pulses selectively excite mechano-thermal nociceptors and evoke brain potentials that may reveal small-fiber dysfunction. We applied CO2-laser pulses to the perioral and supraorbital regions and recorded the scalp laser-evoked potentials (LEPs) and reflex responses in the orbicularis oculi, masticatory, and neck muscles in 30 controls and 10 patients with facial sensory disturbances. Low-intensity pulses readily evoked scalp potentials consisting of a negative component with a latency of 165 ms followed by a positive component at 250 ms. In vertex recordings, the amplitude of LEPs exceeded 30 microV. Although only high-intensity pulses evoked reflex responses, some subjects showed--even to low-intensity pulses--an orbicularis oculi (blink-like) response that markedly contaminated the scalp recording. Scalp LEPs were abnormal in patients with hypalgesia and normal trigeminal reflexes and normal in patients with normal pain sensitivity and abnormal trigeminal reflexes. Possibly because of the high receptor density in this area and the short conduction distance, laser stimulation of the trigeminal territory yields low-threshold and large LEPs, which are useful for detecting dysfunction in peripheral and central pain pathways.

Adult↗
PubMed1999

Effects of repetitive cortical stimulation on the silent period evoked by magnetic stimulation.

The effects of repetitive transcranial stimulation (rTMS) on brain activity remain unknown. In healthy subjects, we studied the effects of rTMS on the duration of the cortical silent period (SP). Repetitive stimuli were delivered with a Cadwell High Speed Magnetic Stimulator and a figure-of-eight coil placed over the hand motor area. rTMS was delivered in trains of 11 or 20 stimuli at frequencies of 3 and 5 Hz and at stimulation intensities of 110 and 120% of motor threshold. The SP was recorded from the forearm muscles during a voluntary contraction (20% of maximum effort). rTMS delivered at a frequency of 3 and 5 Hz and intensities of 110 and 120% motor threshold prolonged the duration of the SP, without modifying either the size or the latency of the muscle-evoked potentials (MEP). A conditioning train of 11 stimuli at 3 Hz had no effect on the duration of the SP evoked by a single magnetic shock delivered 600 ms after the train. These findings show that rTMS increases the duration of the cortical SP, but does so only during the train of stimuli. rTMS probably changes the duration of the SP by facilitating cortical inhibitory interneurons.

Adult↗
PubMed1999

Superficial siderosis of the central nervous system and anticoagulant therapy: a case report.

Superficial siderosis of the central nervous system is a rare condition characterized by deposition of haemosiderin in the leptomeninges and in the subpial layers of the brain and spinal cord. With the widespread use of magnetic resonance imaging, an increasing number of cases of superficial siderosis are being discovered, secondary forms being more frequent than idiopathic ones. We report a 78-year-old man in oral anticoagulant therapy, who presented neurosensory hearing loss, gait ataxia and spastic paraparesis. Magnetic resonance imaging suggested the diagnosis of superficial siderosis of the central nervous system, without an evident bleeding source.

Aged↗
PubMed1999

Botulism: a case associated with pyramidal signs.

Botulism is a widespread neuroparalytic disease that may be confused with other neurological disorders. As it is potentially lethal, clinicians are required to be aware of its diagnosis and management. We report a case of botulism complicated by pyramidal signs in a 35-year-old woman. Clinical aspects, differential diagnoses and therapeutic problems are discussed.

Adult↗