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Biomedical subjects

G Porro

Publications and source records attributed to G Porro.

At least 19 recordsLinked to original sources
PubMed2005

Role of visual dysfunction in postural control in children with cerebral palsy.

INTRODUCTION: Deficient postural control is one of the key problems in cerebral palsy (CP). Little, however, is known about the specific nature of postural problems of children with CP, nor of the relation between abnormal posture and dysfunction of the visual system. AIM OF THE STUDY: To provide additional information on the association of abnormalities in postural control and visual dysfunction of the anterior or posterior part of the visual system. METHODS: Data resulting from ophthalmologic, orthoptic, neurological, neuro-radiological, and ethological investigations of more than 313 neurologically impaired children were retrospectively analyzed. RESULTS: Abnormal postural control related to ocular and ocular motor disorders consisted of anomalous head control and subsequent abnormal head posture and torticollis. The abnormal postural control related to retrochiasmatical damage of the visual system consisted of a torticollis combined with adjustment of the upper part of the body, as if at the same time adapting to a combination of defects and optimizing residual visual functions. CONCLUSION: Visual dysfunctions play a distinct role in the postural control of children with CP.

Adolescent↗
PubMed2001

Neutrophil defensins mediate acute inflammatory response and lung dysfunction in dose-related fashion.

High concentrations of neutrophil defensins from airway and blood have been reported in patients with inflammatory lung diseases, but their exact role is unclear. We investigated the direct effect of defensins on the lungs of mice. Intratracheal instillation of purified defensins (5-30 mg/kg) induced a progressive reduction in peripheral arterial O(2) saturation, increased lung permeability, and enhanced the lung cytochrome c content. These indexes of acute lung dysfunction were associated with an increased total cell number and a significant neutrophil influx into the lung [5.1 +/- 0.04% in control vs. 48.6 +/- 12.7% in the defensin (30 mg/kg) group, P < 0.05]. Elastase concentrations in the bronchoalveolar lavage (BAL) fluids increased from 38 +/- 11 ng/ml (control) to 80 +/- 4 ng/ml (defensins, P < 0.05). Five hours after defensin instillation, concentrations of tumor necrosis factor-alpha and macrophage inflammatory protein-2 in BAL fluid were significantly increased. High levels of monocyte chemoattractant protein-1 in BAL fluid and plasma were also found after defensin stimulation. We conclude that intratracheal instillation of defensins causes acute lung inflammation and dysfunction, suggesting that high concentrations of defensins in the airways may play an important role in the pathogenesis of inflammatory lung diseases.

Animals↗
PubMed1998

Longitudinal follow-up of grating acuity in children affected by cerebral palsy: results of a 5 year study.

PURPOSE: To analyse the natural course of visual acuity in subjects affected by cerebral palsy. METHODS: During the past 5 years, 16 children underwent repeated grating acuity measurements using the acuity card procedure. At the end of the follow-up final grating acuity was compared with linear acuity obtained using standard optotypes. RESULTS: A good or moderate improvement in grating acuity was shown by 14 subjects. However, the general development of grating acuity showed a protracted course and early values did not correlate with final grating acuity (r = 0.20). Moreover, most of the children showed subnormal vision when measured with standard optotypes. CONCLUSION: Clinicians should remain optimistic about the potential for some visual development in children affected by cerebral palsy. However, great caution should be exercised in extrapolating information from early grating acuity measurements. Regular assessments with the acuity card procedure are necessary in order to gain an insight into the natural course of visual development in children affected by cerebral palsy.

Aging↗
PubMed1998

Development of visual function in hemihydranencephaly.

This study reports on the findings of longitudinal follow-up of visual function in a 12-year-old girl affected by congenital right hemihydranencephaly. This extremely rare unilateral brain malformation allowed the authors to gather new information on neuronal plasticity and functional compensations of the visual system across a period of 10 years. An extension of the preserved right visual hemifields above the middle line and strategical eye or head positions developed to increase visual functions are discussed. In addition, ophthalmological and orthoptical findings, as well as the development of monocular grating and linear acuity, are described.

Child↗
PubMed1998

Visual behaviours of neurologically impaired children with cerebral visual impairment: an ethological study.

BACKGROUND/AIMS: Visual functions of neurologically impaired children with permanent cerebral visual impairment (CVI) can be difficult to determine. This study investigated the behavioural profile of CVI children by means of ethological observations in order to gain a better understanding of their visual functions. METHODS: Video registrations of nine subjects who were unable to undergo more orthodox methods of visual function testing were observed and analysed by an ethologist. RESULTS: A series of behaviours (direct signs) and supportive or confirming behavioural elements (indirect signs) indicating some visual perception in the children were found. CONCLUSION: Detailed ethological observations of visual behaviour were shown to be useful for analysing visual functions of children with permanent CVI.

Blinking↗
PubMed1998

Diaminic carbonates, a new class of anti-inflammatory compounds: their biological characterization and mode of action.

Taking advantage of a standard assay on mouse LM cells (murine fibroblast-like cells), we found that several diaminic carbonates, a new class of organic compounds synthesized in our laboratories, were able to inhibit human tumor necrosis factor alpha (huTNFalpha)-induced cytotoxicity in a dose-dependent manner. Structure-function relationship studies indicated precise structural requirements for compounds being active as huTNFalpha inhibitors. ITF1779, one of the most active compounds in inhibiting huTNFalpha-induced cytotoxicity, was selected for further studies. In vitro experiments showed that ITF1779 inhibited not only huTNFalpha-induced cytotoxicity on LM cells but also another response of the same cells, interleukin-1-induced interleukin-6 production. Receptor-binding studies performed under nonequilibrium conditions and morphologic evidence of vacuole formation in cells treated with high concentrations of ITF1779 showed that the effects were strikingly similar to those of chloroquine, a lysosomotropic agent. Consistent with a mechanism of action of diaminic carbonates closely matching that of chloroquine are some structural similarities between the two classes of compounds, in particular their both being diprotic weak bases. Moreover, ITF1779 was shown to be active in vivo because it afforded protection against lipopolysaccharide-induced shock in mice, a systemic inflammatory response crucially dependent on tumor necrosis factoralpha production.

Animals↗
PubMed1995

Cochaperonins are histone-binding proteins.

Cochaperonins (cpn10) assist chaperonins (cpn60) in mediating folding of polypeptide substrates in an ATP-dependent reaction. Moreover, they have been shown to be secretory products of living cells and to perform discrete biological activities without the need to interact with cpn60. Here, we have investigated the possible existence of cellular cpn10 binding sites that could mediate such activities. For this purpose, we performed binding studies with iodinated cpn10 on whole cells and on electrophoretically separated eukaryotic cell lysates. The former studies yielded negative results, whereas in the latter binding to several proteins was detected. These proteins were identified as being histones. Binding was observed to all core histones (H2A, H2B, H3 and H4) and, although weaker, to the linker histone H1 as well. These results show that cpn10 are histone-binding proteins.

Animals↗
PubMed1995

Different cytotoxic activity and intracellular fate of an anti-CD5-momordin immunotoxin in normal compared to tumour cells.

We investigated the different sensitivity of peripheral blood mononuclear cells (PBMC) and human T cell leukaemias (Jurkat and CEM) to an anti-CD5-momordin immunotoxin. In a short-term assay, the immunotoxin displayed different cytotoxic activity on normal and tumour cells: for leukaemic cell lines an incubation time of 72 h was necessary for the immunotoxin to reach the IC50 of 41-53 pM, compared to the 1 h sufficient for 6 pM immunotoxin to inhibit 50% of PBMC protein synthesis. In a long-term clonogenic assay (15 days), the immunotoxin demonstrated a comparable efficacy of clonogenic cell killing for both cell types. We investigated the immunotoxin internalization pathway by a flow-cytometric method and our data seem to indicate that the molecules meet a different intracellular fate in the two cell populations. It may be assumed that the low cytotoxic activity of immunotoxins on tumour cells, detected in the short-term assay, is due to inefficient delivery to their cytoplasmatic target, while a longer exposure of the cells to the immunotoxin promotes adequate intracellular distribution.

Antibodies, Monoclonal↗
PubMed1994

Production and characterization of monoclonal antibodies against the ribosome inactivating proteins dianthin32 and momochin.

Female BALB/c mice were immunized with either dianthin32 or momochin, type 1 ribosome-inactivating proteins (RIPs) derived from Dianthus charyophyllus and Momordica cochinchinensis, respectively. Five anti-dianthin32 and 6 anti-momochin secreting hybridomas were obtained by somatic fusion of lymphocytes with myeloma cell line NS0. The monoclonal antibodies (MAbs) produced were highly specific, as demonstrated by cross-reactivity assays performed with taxonomically related and unrelated type 1 RIPs, and recognized different epitopes of the antigen. The affinity constant of anti-RIPs MAbs ranged between 10(8) M-1 and 10(10) M-1.

Animals↗
PubMed1993

Preferential looking: parameters and preliminary data of a new computerized version.

A computerized version of preferential looking (CPL) was developed by the authors. Formal parameters (spatial frequency, luminance, contrast of the stimuli; randomized procedure; computerized statistical control) and preliminary binocular acuity results in 69 healthy children (6-36 months) are compared to those of OPL, FPL and ACP version. Low cost, standardized procedure, statistical control of visual acuity estimates and the need of one operator only are among CPL advantages.

Child, Preschool↗
PubMed1993

Preferential looking techniques yield important information in strabismic amblyopia follow-up.

Two groups of monocular strabismic patients were followed-up by means of both PL and orthoptic examinations. The first group underwent a full-day occlusion except 1 to 4 hours; the second was occluded less than 4 hours per day. The first treatment regimen proved to be faster in getting pseudo-isoacuity and alternating fixation, but was followed by relative occlusion amblyopia and/or shifting of the dominant eye in three patients. PL techniques proved to be particularly useful in strictly monitoring these patients.

Amblyopia↗
PubMed1993

In vitro and in vivo properties of an anti-CD5-momordin immunotoxin on normal and neoplastic T lymphocytes.

An anti-CD5 monoclonal antibody (mAb) was linked to the plant toxin momordin, a type-1 ribosome-inactivating protein purified from Momordica charantia. The in vitro cytotoxicity of the immunotoxin was evaluated as the inhibition of protein and/or DNA synthesis on isolated peripheral blood mononuclear cells (PBMC) and on human T cell leukemia Jurkat. The potency of the immunotoxin on PBMC was very high (IC50 = 1 - 10 pM) and was not affected by blood components. The conjugate was also very efficient in the inhibition of the proliferative response in a mixed lymphocyte reaction (IC50 = 10 pM). Moreover, the in vitro performance of the immunotoxin compared favorably with those reported for other anti-CD5-based immunoconjugates containing ricin A chain. The in vivo activity of the immunotoxin was assessed in the model of nu/nu mice bearing Jurkat leukemia. A significant inhibition of the tumour development (80%, P < 0.01) in the animals treated with immunotoxin was observed. Taken together, the in vitro and in vivo results suggest that the anti-CD5-momordin conjugate may be useful for graft-versus-host disease therapy and potentially in the treatment of CD5-positive leukemias and lymphomas.

Animals↗
PubMed1990

Self-induced pattern-sensitive epilepsy in childhood.

We studied five children (1 boy and 4 girls) with self-induced pattern-sensitive epilepsy. All patients had refractory epilepsy with multiform, though mainly myoclonic, seizures and medium grade to severe mental retardation. Spontaneously self-induced seizures were documented in all cases by EEG. All the patients underwent full neurophysiological assessment (baseline EEG recording, with activation: eyelid closed, hyperventilation, ILS, EEG during the randomized presentation of 3 types of spatial structured stimuli, VEP-F and VEP-PR). The pattern that triggered the EEG anomalies was highly specific and selective for each patient. Clinical seizures were reproduced by the same patterns as the ones used by the patients to bring on the seizures at will. Authors stress the importance of identifying such peculiar type of epilepsy and of attempting adequate treatment.

Child↗
PubMed1989

Electrocardiographic abnormalities in childhood spinal muscular atrophy.

Tremors of the isoelectric line in routine electrocardiograms have been described in patients with spinal muscular atrophy and have been interpreted as fasciculations of denervated muscles. In order to evaluate this phenomenon, 13 patients with spinal muscular atrophy have been studied (average age: 37.3 months). A first electrocardiogram was recorded routinely; a second tracing was then recorded with double sensitivity and double speed. In addition, all patients were evaluated clinically and had M-mode and cross-sectional echocardiography. Regular and constant spikes on the isoelectric electrocardiographic line were recorded in 12 patients (93.4%); their frequency ranged from 39 to 48 cycles/sec (average: 42.08 +/- 2.64). Contrary to previous reports, we found an "abnormal" electrocardiogram in all our patients with severe spinal muscular atrophy. The only patient with a normal electrocardiogram had a mild and clinically stable form of spinal muscular atrophy. We did not find any significant structural cardiac abnormality by clinical and echocardiographic evaluation. We conclude that continuous tremor on the isoelectric line of electrocardiogram represents a characteristic of spinal muscular atrophy in these patients. It is a result of muscle fasciculations and does not imply any abnormality of the heart.

Adolescent↗
PubMed1989

Intractable epilepsies. An open trial with Clobazam.

Clobazam was used as an added treatment in 28 patients with intractable epilepsies: 26 subjects had associated handicaps. A good response was observed during the first two-three months of Clobazam treatment: the reduction in seizure frequency of 73% for partial seizures and 62% for GTCs. A tolerance to Clobazam treatment was observed after the third month of treatment: at the end of the sixth month, the seizure frequency was reduced to 36% for partial seizures and 39% for GTCs. Out of 28 patients 4 were seizure free at the end of the sixth month; we have not found any specific characteristic in these patients. The AA. suggest the possibility of an intermittent use of Clobazam for this type of patients.

Adolescent↗
PubMed1988

Monoclonal antibody detection of carcinoma cells in bone marrow biopsy specimens from breast cancer patients.

The possibility of using immunologic methods for detecting metastatic cells in bone marrow samples from breast cancer patients was investigated. The MBr1 monoclonal antibody, which recognizes a membrane antigen on breast carcinoma cells and is unreactive on normal bone marrow cells, seemed to be an adequate reagent for this kind of approach. When human leukocyte suspensions artificially contaminated with mammary tumor cells were tested by MBr1 immunofluorescence, it was demonstrated that the added tumor cells could be specifically discriminated from normal cells and that as little as one tumor cell in 200,000 could be detected. With the same methodology we screened bone marrow biopsies from breast cancer patients with apparently uninvolved lymph nodes at the moment of surgery. Immunoreactive tumor cells were detected by the MBr1 antibody in 17% of N- patients. None of the bone marrow samples showed any evidence of tumor involvement by conventional histologic analysis.

Antibodies, Monoclonal↗