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Biomedical subjects

R Bergamaschi

Publications and source records attributed to R Bergamaschi.

At least 145 records · Page 8Linked to original sources
PubMed1992

The reliability of eye movement quantitative evaluation. II. Smooth pursuit eye movements.

We adopted the estimate of the intraclass coefficient of reliability, R, to evaluate the reliability of smooth pursuit eye movement quantitative analysis. At a one-week interval, we recorded twice smooth pursuit eye movements from fifteen healthy subjects by means of the binocular electrooculographic technique. R was computed for the constant and the slope of the target velocity/gain relationships. R values were rated good for the slope and excellent for the constant. Finally, we computed for each parameter the maximum variability value according to two differing methods; on the basis of the within-subjects mean square values, we defined the normal range of biological test-retest variability for the two parameters.

Adult↗
PubMed1992

[Trans-suture anastomosis. Choice of procedure in the management of colorectal anastomosis].

The double stapling technique was used to perform low anterior resection for rectal tumors in 122 patients (68 men, 54 women) with a mean age of 65 years (range, 28 to 87 years). There was no perioperative death. Technical problems related to the stapling technique and requiring transitory colostomy occurred in one patients. The clinical anastomotic leak rate was 5 per cent (six patients); in 2 patients, the fistula was treated successfully with a defunctioning transverse loop colostomy. Hospital stay ranged from 6 to 23 days (mean 10.2 days). Continence was normal in all patients at 6 weeks. One soft colo-anal anastomotic stenosis required dilatation. These results appear promising. The double stapling technique appears to facilitate low anterior resection of the rectum with safety.

Adult↗
PubMed1991

Multimodal evoked potentials in progressive external ophthalmoplegia with mitochondrial myopathy.

Multimodal evoked potentials were studied in 13 patients affected by progressive external ophthalmoplegia with histologically proven mitochondrial myopathy. Progressive external ophthalmoplegia occurred with craniosomatic spreading in all the patients and with a varying degree of nervous and/or other system involvement in most of them. In all but one of the subjects, at least one evoked potential modality was abnormal; 11 of them demonstrated an abnormal visual evoked potential, but this finding might have been influenced by concurrent retinal dysfunction. Abnormalities in brainstem auditory evoked potentials and/or somatosensory evoked potentials, revealing an impairment of central sensory pathways, were detected in 7 subjects, 5 of whom lacked clinical evidence of central nervous system involvement. Thus, evoked potentials represent an useful tool for the detection of subclinical central nervous system involvement in patients affected by progressive external ophthalmoplegia with mitochondrial myopathy.

Adult↗
PubMed1991

Somatosensory evoked potentials by electrical stimulation of the third trigeminal branch in humans.

Somatosensory Evoked Potentials by stimulation of the trigeminal nerve (TSEPs) were recorded from 30 healthy subjects (15 males, 15 females; mean age: 45.2 years; range: 21-66 years) in order to assess normative data for clinical purposes. To elicit the TSEPs, electrical square pulses (duration: 0.1 msec; frequency: 3.3 Hz; intensity: 4-6 mA) were delivered by bipolar skin electrodes (cathode over the foramen mentale and anode on the middle of the chin, stimulating the trigeminal third branch). TSEPs were obtained from C3-Fpz and C4-Fpz by twice averaging 1000 responses. Time base was 100 msec; bandpass filter setting was 5-1500 Hz. In our normal subjects the TSEPs were composed of several components (N1, P1, N2, P2 and N3); the components, with the exception of N3, were always bilaterally detectable. Statistical analysis (repeated measures analysis of variance) demonstrated a dependence of TSEP latencies on sex; it did not demonstrate an analogous dependence on either side of stimulation or age. Finally, we propose some guidelines for the evaluation of TSEPs: consider N1, P1, N2 and P2 waves, base the judgement of normality on latencies rather on amplitudes, use differing normative data according to sex.

Adult↗
PubMed1991

Visual evoked potentials in the white New Zealand rabbit: source localization and normative aspects.

Normative data of visual evoked potentials were obtained from occipital screw electrodes referenced to a nasal electrode in 10 white New Zealand rabbits. Two time-bases were used (200 and 400 ms) in order to reliably identify both early components (of retinal and cortical origin), as well as late components. The putative origin of the single components was established by simultaneous recording of ERG and by stereotaxic recordings from the lateral geniculate body. Test-retest variability was measured repeating the recordings after 24 hours.

Animals↗
PubMed1991

Brainstem auditory evoked potentials in the rabbit.

Eight white New Zealand rabbits were submitted to auditory stimulation in order to obtain normative BAEP parameters. A monaural alternating 0.1 ms click stimulation at 20 Hz, 90 dB was used. Two series of 1000 responses were averaged (10 ms time-base, 160-3000 Hz band-pass) and highly reproducible peaks were obtained. Peaks P1, P2, P3, P4 were obtained in all ipsilateral recordings, whereas peak P5 was detectable in only 6 animals. In contralateral recordings P1 was absent and the following peaks were similar to those of ipsilateral recordings. Normative values of absolute and interpeak latencies, peak amplitudes and amplitude ratios were obtained. The procedure was repeated 24 hours after basal recordings and measures of test-retest variability were obtained.

Animals↗
PubMed1991

Prestimulus EEG influence on late ERP components.

Ten healthy volunteers were submitted to an auditory oddball event related potentials (ERP) paradigm. Single trial 500 ms poststimulus ERPs (Pz, Cz, Fz--linked earlobes) along with the correspondent 1000 ms prestimulus EEG (O1-Cz) were stored. EEG epochs were submitted to spectral analysis and a slow wave index (SWI = delta + theta/total) was computed. Three selective ERP averages corresponding to low, medium and high SWI were computed. N2 latency was longer and P3a amplitude was lower in high SWI averages as compared to low SWI averages.

Analysis of Variance↗
PubMed1991

Effect of repetition rate on middle latency auditory evoked potentials in humans.

Middle Latency Auditory Evoked Potentials (MLAEPs) were recorded from 15 healthy subjects in order to evaluate the influence of different repetition rates on the latency and the amplitude of their main components Na, Pa and Nb. MLAEPs were obtained from Cz-ipsilateral ear lobe by averaging responses to 2000 monaural clicks delivered to both ears, at 65 dB SL of intensity, for each of 3 different repetition rates (1.1, 4.1, 8.1 Hz). Time base was 100 ms, analogical band-pass filter 5-1000 Hz (off-line digital bandpass: 20-100 Hz). The statistical analysis (repeated measures analysis of variance), demonstrated that, the latency and the amplitude of the Nb component were slightly influenced by repetition rate while Pa and Na were not. Moreover Nb showed the greatest interindividual variability (as already pointed out by other authors too); thus, we suggest that a stimulus rate of 8.1 Hz and the analysis of Na and Pa component only, can be regarded as the best assessment for MLAEPs evaluation when they are used for clinical purposes.

Adult↗
PubMed1991

Effect of stimulus mode on middle latency auditory evoked potentials in humans.

Middle Latency Auditory Evoked Potentials (MLAEPs) were recorded in 35 healthy subjects; all underwent monaural stimulation and 18 of them additionally underwent binaural stimulation. The aim of the study was to determine the effect of stimulus mode on MLAEP Na, Pa and Nb components and to assess normative data for clinical purposes. MLAEPs were respectively obtained from Cz-ipsilateral ear lobe (monaural mode) and from Cz-A1 and Cz-A2 (binaural mode) by twice averaging 1000 responses to 65 dBHL alternating clicks delivered at a repetition rate of 8.1 Hz. Time base was 100 msec; analogical band-pass filter setting was 5-1000 Hz (off-line digital badpass: 20-100 Hz). The statistical analyses (paired t-test, repeated measures analysis of variance) were not able to demonstrate any differences that derived from differing sides of stimulation (monaural mode) or from differing recording derivations (binaural mode); on the contrary, we demonstrated a slight increase in waveform amplitudes when the binaural mode was employed. In particular, we observed an increase in Na-Pa peak-to-peak amplitude, whereas Pa-Nb amplitude was unmodified. This finding is explicable in terms of a binaural interaction effect. Finally, we propose some guidelines for the correct performance and evaluation of MLAEPs in clinical practice.

Acoustic Stimulation↗
PubMed1991

Multimodal evoked potentials in diabetics.

In the present study we performed brainstem auditory evoked potentials, pattern electroretinogram and visual evoked potentials for the identification of a subclinical involvement of central auditory and visual pathways in diabetes mellitus. We tested 30 patients, and a neurophysiological central nervous system involvement was demonstrated in 23.3% of them. The mean values of patients and controls were significantly different for most of the evoked potential parameters. Some of these parameters were linearly related with duration of the disease, clinical score and peripheral nerve conduction velocities.

Adult↗
PubMed1990

Bronchial reactivity and sex hormone: study in a Turner's population.

Respiratory function and bronchial reactivity was studied by carbachol challenge in 41 patients with Turner's syndrome and in 46 controls. In patients and controls the personal and family history of atopic illnesses was evaluated; reactivity to skin allergen tests was studied in patients only. Patients with Turner's syndrome had less allergy skin test reactivity; no difference was found in allergic symptoms between patients and controls despite the patients having a more positive family history of atopy (P less than 0.05). Respiratory function variables were higher in patients than in controls, and bronchial reactivity as expressed by the results of carbachol testing was higher in Turner's patients than in controls (P less than 0.01). Bronchial reactivity was significantly reduced after 6 months of estrogenic therapy (P less than 0.05) in subjects with Turner's syndrome, while the same did not occur in patients who did not receive estrogen treatment. This study of pulmonary function and bronchial reactivity in Turner's patients may help understand the effects of sex hormones in the regulation of bronchial tone and of bronchial response to constrictive agents.

Adolescent↗
PubMed1990

Effects of sport (football) on growth: auxological, anthropometric and hormonal aspects.

There are very few data available on the relationship between sporting activities, endocrine levels and changes in anthropometric measurements during growth. In order to study these relationships, we have made measurements of growth, changes in physical conformation and the plasma levels of several hormones [cortisol, dehydroepiandrosterone sulphate (DHEA-S), testosterone, growth hormone, somatomedin C, insulin, glycaemia and haemoglobin A1C] in 175 boys, aged 10-16 years, who have played football at a competitive level and in 224 boys, severing as controls, who have never performed sporting activities regularly. The football players were divided into prepubertal and pubertal subjects (10-11.99 years, 12-13.99 years and 14-16 years, chronological and bone age groups). Our results showed no significant differences in the growth indices between prepubertal athletes and controls, but the plasma level of DHEA-S was significantly higher (P less than 0.05) in the athletes. Pubertal football players, however, were significantly taller than the control subjects, particularly at 14-16 years chronological age. There were no such significant differences when bone age was considered. The pubertal football players were also more advanced in all biological indices of maturity, i.e. pubic hair, testicular volume and bone age. The increase in DHEA-S in pubertal football players, already seen in prepubertals, was also combined with a significant increase in testosterone, growth hormone and cortisol levels. Thus, in football players the DHEA-S level is already higher during prepuberty. This increase thus precedes all other indices of growth and maturation associated with puberty. We hypothesize that, while not excluding the possible influence of selection, as ours is a cross-sectional study, adrenal hyperactivity may be mainly responsible for the earlier onset of pubertal growth and maturity in exercising males.

Adolescent↗
PubMed1990

Devic's neuromyelitis optica: long-term follow-up and serial CSF findings in two cases.

Sixteen cerebrospinal fluid (CSF) specimens serially obtained during long-term follow-up of two patients with Devic's neuromyelitis optica (DNO) were compared with 65 CSF samples from patients with multiple sclerosis (MS). By statistical analysis, the CSF profile in DNO was found to differ from that observed in MS, mainly showing pleocytosis, blood-brain barrier damage, and absence of persistent immunoglobulin G synthesis within the central nervous system. Oligoclonal bands, detected with isoelectric focusing, were present in CSF of 92% of the patients with MS, and in three CSF specimens from one patient with DNO during the first 6 months after disease onset. The bands disappeared in two subsequent samples. This finding has never been described in MS. One patient with DNO had an apparent chronic-relapsing course probably due to steroid dependence. The clinical and CSF features of our cases favour the nosographic independence of DNO and MS.

Adult↗
PubMed1990

Progress in the assessment of lymphatic spread in rectal cancer. Rectal endoscopic lymphoscintigraphy.

Rectal endoscopic lymphoscintigraphy was performed in 10 control subjects and in a series of 85 patients with adenocarcinoma of the rectum as a prospective study to evaluate lymphatic drainage of the rectum and lymphatic spread in rectal cancer. Complete cranial drainage was demonstrated in all control subjects, and internal iliac nodes were also visible in 50 percent of cases. Results were correlated with histologic node examination in all patients operated upon for rectal cancer. Rectal endoscopic lymphoscintigraphy was assessed for sensitivity (85 percent), specificity (68 percent), overall accuracy (76 percent), positive predictive value (71 percent), and negative predictive value (83 percent). False-negative and false-positive results are discussed. Rectal endoscopic lymphoscintigraphy represents the only method currently available for evaluation of lymphatic spread in rectal cancer.

Adenocarcinoma↗
PubMed1989

[Acute colonic hemorrhage. Importance of a preoperative localization of the origin of bleeding in patients requiring emergency surgery].

Conservative management of distal gastro-intestinal bleeding is successful in most cases; 10% of patients hospitalised with this diagnosis will however undergo emergency surgery. Preoperative localisation of the bleeding site allows to perform a limited, segmental colectomy even in emergency. This has been shown to be associated with a lower operative mortality and morbidity when compared with subtotal colectomy. In this retrospective study we reviewed the notes of 134 patients admitted with lower gastro-intestinal bleeding. 22 of these required more than 4 units of blood transfusion and 12 underwent emergency surgery. Preoperative localisation of the source of bleeding was possible in 7 cases (58%); the remaining 5 underwent a subtotal colectomy. The operative mortality was 8%. The Authors emphasise the importance of an aggressive diagnostic work up in all cases of massive bleeding (i.e. more than 4 units of blood requirement in the first 24 hours following hospitalisation) in order to minimise the number of emergency subtotal colectomy.

Acute Disease↗
PubMed1989

Tumor necrosis factor in serum and cerebrospinal fluid of patients with multiple sclerosis.

We measured levels of alpha-tumor necrosis factor (alpha-TNF) in cerebrospinal fluid and serum samples from 50 drug-free patients with multiple sclerosis, 25 patients with other neurological diseases, 27 patients with non-neurological diseases, and 10 normal subjects. The most elevated levels of alpha-TNF were found in patients with inflammatory or autoimmune diseases. Comparable serum levels of alpha-TNF were detected in normal control subjects, patients with multiple sclerosis, and patients with degenerative neurological diseases. In patients with multiple sclerosis, alpha-TNF levels were also unrelated to time elapsed between the occurrence of clinical exacerbation and the time of sample collection. Only 3 patients with chronic progressive multiple sclerosis had detectable alpha-TNF in the cerebrospinal fluid. Our data do not support a role for elevated levels of circulating alpha-TNF in the maintenance of the disease. However, we cannot rule out the possibility that a transient elevation of alpha-TNF triggers the cellular events leading to demyelination in multiple sclerosis.

Adolescent↗
PubMed1989

Brainstem impairment in multiple sclerosis: an assessment by multimodal evoked potentials.

The usefulness of multimodal evoked potentials for the diagnosis of Multiple Sclerosis (MS) is established. Our purpose was to try to set of 3 EPs (BAEP, median SEP and trigeminal SEP) in the evaluation of brainstem dysfunction. 53 definite and probable MS patients have been examined; they were allotted to 3 groups according to the duration of the disease. Our results showed that median SEP is the most sensitive investigation, while BAEP and trigeminal SEP were abnormal in a smaller number of cases. The combined use of median and trigeminal SEPs supplied sufficient information on brainstem function, without using the complete set of EPs. No significant relation between EP abnormalities and duration of the disease was found.

Acoustic Stimulation↗