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Biomedical subjects

M Morelli

Publications and source records attributed to M Morelli.

178 records · Page 10Linked to original sources
PubMed1978

Self-inhibitory dopamine-receptors and central effects of apomorphine.

Apomorphine, a central dopamine-receptor agonist, is well known to produce excitatory effects in animals. However, low doses exert depressant effects as hypomotility, sedation and sleep. The mechanism of these effects are discussed in terms of a stimulation by apomorphine of DA-receptors, different from the post-synaptic ones, provided of an inhibitory effect on DA-synthesis and on the firing of dopaminergic neurons.

Animals↗
PubMedDate not supplied

Immunohistochemical telomeric-repeat binding factor-1 expression in gastrointestinal tumors.

The maintenance of telomere length has been hypothesized to be involved in the early steps of cancerogenesis. A physiologic modulation of telomere maintenance is exerted by TRF1 (telomeric-repeat binding factor-1), which deletion permits telomere elongation. Gastrointestinal neoplastic (n=19) and non-neoplastic tissues (six inflammatory disease and six normal mucosa distant from tumor at least 5 cm) were studied, by immunohistochemistry, for TRF1 expression, by using a polyclonal antibody anti-TRF1. Differentiated and not proliferating epithelial secretory cells (Ki67 and p53 negative cells) were stained by anti-TRF1, which did not stain tumor cells in all cases but one (p<0.0001). p53 was expressed by 26% of tumor cases. Inflammatory gastrointestinal non-tumor tissues showed lower expression of TRF1 in epithelial secreting cells compared to normal tissues (p=0.008). These preliminary data suggest that down-regulation of the TRF1 expression in tumor cells may be involved in cell immortalization as an initial step in gastrointestinal carcinogenesis (before p53 alteration), and may open new perspectives, when confirmed, in gastrointestinal tumor prognosis.

Adenocarcinoma↗
PubMedDate not supplied

Do cutaneous receptors contribute to the changes in the amplitude of the H-reflex during massage?

Massage is known to produce a reduction in spinal reflex excitability. However, the mechanisms subserving this phenomenon have yet to be elucidated. This study was undertaken to determine the role of superficial cutaneoreceptors overlying the triceps surae during the application of a massage. Twelve neurologically healthy volunteers were subjected to an interrupted repeated measures design consisting of eight conditions. Each condition was comprised of eleven H-reflex recordings obtained from the right soleus muscle. Six conditions served to establish baseline control levels, while the remaining two conditions consisted of reflex recordings obtained simultaneous to the application of the massage. During the first massage condition, subjects were at rest while a three minute petrissage was applied to the right triceps surae muscle group. The second massage condition was always preceded by the application of a topical anaesthetic to abolish the sensation to touch and pin-prick to the skin area that was to be massaged. It was expected that the cutaneous afferents would not play any major role in the changes associated with the application of the massage. H-reflex amplitudes recorded during each massage condition (1.20 mV +/- 0.30 SEM, 1.05 mV +/- 0.23 SEM, respectively) were significantly reduced (F7.77 = 26.048, p < 0.01) in contrast to all control conditions (range: 2.21 to 2.63 mV). However, no difference was observed between the two massage conditions. The inhibitory effects of massage on the soleus H-reflex do not appear to originate from mechanical stimulation of cutaneous mechanoreceptors. It seems more likely that deep mechanoreceptors are involved.

Adult↗
PubMedDate not supplied

Immunohistochemical TRF1 expression in human primary intracranial tumors.

BACKGROUND: The telomeric-repeat binding factor (TRF1) participates in a physiological homeostatic mechanism controlling telomere shortening by inhibiting telomerase activity: down-regulation of TRF1 expression results in telomere elongation and may be involved in cell immortalization. PATIENTS AND METHODS: To determine the TRF1 expression by immunohistochemistry (IHC) in human brain tumors, a cohort of 20 consecutive flash-frozen surgical specimens (14 meningiomas and 6 anaplastic astrocytomas (AA)) were collected. RESULTS: Variable levels of TRF1 expression in 12 out of the 14 (87.5%) meningioma samples were observed. By contrast, no expression of TRF1 in tissue samples from AA (p = 0.008) was detected. Positive TRF1 cells were usually more differentiated (less atypical features) and Ki67 negative (inverse statistical association, chi2 = p < 0.001). CONCLUSION: We demonstrated, for the first time, that routine IHC techniques are capable of identifying TRF1 expression in intracranial tumors, which is heterogeneously expressed in meningiomas, but absent in AA. Although these preliminary observations need confirmation from larger studies, the TRF1 status in intracranial tumors might become of prognostic value.

Brain Neoplasms↗
PubMedDate not supplied

Reliability of individual differences for H-reflex recordings.

Complementary data from two closely-related experiments were analyzed to investigate the reliability of individual differences of H-reflex amplitude. Some concomitant analysis of M-reflex was also included. The purpose was to do this in a manner that was more direct and more detailed than found hitherto in the literature. Fundamental techniques espoused particularly by F.M. Henry (1969) formed the basis of this approach. The aims included a clearer quantification of reliability with a distinction between inter- and intra-individual sources of variation, an analysis of the effects different numbers of trials had on reliability, and an investigation of the progression of reliability over a 20-trial sequence of observations. The control conditions of both experiments were designed to be essentially identical with respect to subject position, stimulus and recording configurations. Experiment 1 had 20 subjects, four control conditions of 10-trials in each while experiment 2 had 18 subjects, five control conditions and 20 trials. The posterior tibial nerve was percutaneously stimulated every 10 sec. and surface electromyographic recordings were made from the soleus muscle. H-reflex and M-reflex amplitudes were measured on every trial. It was found that the reliability of individual differences of both H-reflex and M-reflex was extremely robust with the majority of coefficients being above .950. In addition, the reliabilities remained high when as few as four trials were examined. The pattern of individual differences over the longer series of trials confirmed the stability of interindividual differences and showed that subjects became more consistent in their responses as trials progressed.(ABSTRACT TRUNCATED AT 250 WORDS)

H-Reflex↗
PubMedDate not supplied

Comparison of human triceps surae H-reflexes obtained from mid and distal recording sites.

The purpose of this study was to determine whether a distal triceps surae recording site produced H-reflex responses similar to those obtained from the conventional soleus location in 10 healthy subjects at rest. H-reflex and M-response recruitment profiles were generated and the peak-to-peak amplitudes were measured from the two sites simultaneously. Following this, an H-reflex control signal was determined (peak-to-peak amplitude approximately equal to 30% Mmax) and 4 series of 10 trials were recorded at 5 minute intervals. A paired t-test showed non-significant (p greater than 0.05) differences in Hmax, Mmax, and Hmax: Mmax values recorded from the two sites. Linear regression analyses of recruitment profile H-reflexes and M-responses, obtained simultaneously from the two recording sites showed strong correlations (r greater than 0.90, p less than 0.001). To assess the stability of the reflex over time, intraclass correlation coefficients (ICC) were computed for each recording site (R = 0.99 in both instances). Thus the distal recording site, just proximal to the flare of the medial malleolus, is an acceptable alternative to the conventional recording location. This permits recording H-reflex amplitude changes, resulting from the application of a therapeutic intervention to the calf muscles, without having to remove and reposition the recording electrodes.

Adult↗
PubMedDate not supplied

[Percutaneous dilatational tracheostomy. Critical considerations after one year's experience].

The authors discuss a series of 57 patients submitted to percutaneous dilational tracheostomy (PDT) in an Intensive Care Unit during a fifteen months periods. Patients were admitted for cardiac and/or respiratory failure in 27 cases (47%), sepsis in 13 cases (23%), shock in 12 cases (21%), coma in 5 cases (9%). Length of orotracheal intubation before PDT was 8.3 days +/- 3.9 without significant differences between Apache II and Saps scores at this time (17.4 +/- 6.3 and 20.4 +/- 4.3 respectively) and on admission day (19.3 +/- 6.25 and 20.8 +/- 3.6). The main complications we had to deal with during PDT were damage to previously inserted orotracheal tube, a pneumomediastinum, a small oozing of blood in three cases a serious bleeding in a septic patient with coagulation disorder. After these we performed PDT always coupled with fibrotrachoscopy in the aim to ameliorate PDT safety. On subsequent days the more frequent complication come up at the time of changing tracheal cannula and consisted in troubles ascribed to tracheal shreds (four cases) and one major bleeding after the maneuver always overcome. We also report one death due to impossibility cannula repositioning and subsequent failed intubation in a previously decannulated patient who developed trachobronchial obstruction. Although a supposed midline approach between second and third tracheal rings, was supposed autopsy (performed in three patients) revealed a lateralized cut in one case and an approach higher in another patient. The main advantages in our practice were the absence fo PDT related infections and an optimal and fast tracheal closure after cannula removal. In spite of some limits, this technique has quickly and totally replaced in our practice surgical tracheostomy.

Aged↗
PubMedDate not supplied

[Schwannomas of the digestive tract. Observations on a case localizing in the ileum].

The schwannomas are rare tumors taking origin from Schwann's cells; even rarer is their location at a peripheral level. Even if they show the macroscopic and microscopic characteristics of a benign tumor, it is possible that they engage malignant course, with possibility of recurrency and of distant metastasis. In the alimentary tract the schwannomas reveal with repeated episodes of digestive hemorrhage which could engage, according to the location, the characters of enterorrhagia or melena. Arteriography has the higher diagnostic sensibility, in course of bleeding. The CT could demonstrate a submucosal neoplasia. The diagnosis of schwannomas is based on the immunohistochemical search of the protein S100, that allows to differentiate them from the tumors of muscular origin, having such tumors common histological and cytological aspects. The schwannomas are today set in the widest chapter of the so-called "stromal tumors of the gastrointestinal tract" (GISTs) with an indefinite malignancy which need surgical excision and an attentive follow-up. The authors report a case of schwannoma located at the first jejunal loop, having had repeated episodes of digestive hemorrhage. The diagnosis was based on the selective arteriography of the upper mesenteric artery and the immunohistochemical search of the protein S100. The surgical treatment consisted of the resection of the jejunal loop, after having sought for eventual multiple locations of the neoplasia.

Female↗
PubMedDate not supplied

[Comparison of hernioplasty using the technic of Bassini and Trabucco. Comparative analysis and results].

We evaluated comparatively trough a randomized perspective study the hernioplasty by Bassini technique and the Trabucco repair, respectively using general and local anaesthesia, in a group of 80 patients. We studied incidence of complications and recurrences, surgery, in-patient hospitalization time, postoperative pain, costs and work resuming. Trabucco repair had better results in each considered parameter: hospitalization time, pain and costs respectively 80%, 50% and 66% lower vs Bassini technique; moreover we found no recurrence and work resuming two weeks shorter.

Adult↗