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Biomedical subjects

A Cattaneo

Publications and source records attributed to A Cattaneo.

At least 127 records · Page 7Linked to original sources
PubMed1994

Topical calcipotriol (MC 903) for psoriasis: a clinical study.

Calcipotriol, a non-calcemic vitamin D3 analogue, inhibits the proliferation and is necessary for final differentiation of keratinocytes. The aim of the present study was to determine the efficacy and tolerability of calcipotriol ointment in patients treated for 6 weeks. Twenty patients with chronic plaque-type psoriasis were treated twice daily with calcipotriol ointment 50 ng/g. After 6 weeks' treatment there was a marked and statistically significant decrease in the PASI score values for 17 patients, no improvement was seen in 1 patient and local adverse events occurred in 2. Hypercalcemia or other laboratory abnormalities did not develop in any patient.

Administration, Topical↗
PubMed1994

Vulvar lichen sclerosus. Immunohistologic evaluation before and after therapy.

In 20 women with vulvar lichen sclerosus (LS) we analyzed the immunohistologic features of the dermal lymphoid infiltrate and the number of epidermal CD1a+ cells (Langerhans cells). Activated (HLA-Dr+) T cells, associated with CD1a+ accessory cells, were found in the dermis in all cases. The number of CD1a+ epidermal cells was increased, and the cells expressed strong HLA-DR+ staining. These findings suggest activation of the skin immune system in vulvar LS lesions. Conventional 2% testosterone therapy failed to modify the immunohistologic features. Clobetasol, 0.05%, application seemed more effective in down-regulating the skin's immune system activation profile.

Adolescent↗
PubMed1994

Current role of vaccination in preventing acute respiratory infections in children in developing countries.

Acute respiratory infections (ARI) cause more than four million childhood deaths each year in developing countries. In addition to standard case management, vaccines have a great potential for reducing these deaths. Immunization against measles and pertussis, already reaching more than 70% of infants in developing countries, contributes to the prevention of more than one million childhood deaths. New conjugate vaccines against Haemophilus influenzae type b, if shown to be effective against pneumonia in developing countries, could reduce acute lower respiratory infection (ALRI) deaths by 4%. A further 10% reduction could be obtained by the availability of an effective conjugate vaccine against Streptococcus pneumoniae. A safe vaccine against respiratory syncytial virus could also prevent 10% of ALRI deaths. The potential role of other bacterial and viral vaccines needs to be clarified.

Acute Disease↗
PubMed1993

Intracellular expression of anti-p21ras single chain Fv fragments inhibits meiotic maturation of xenopus oocytes.

The recombinant variable regions of the monoclonal antibody Y13-259, directed against the p21ras protein, have been engineered for expression as intracellular single chain Fv fragments. The activity of the plasmid was confirmed by in vitro and in vivo translation of mRNA showing that the intracellularly expressed single chain fragments are stably and efficiently expressed as cytosolic proteins. The expression of the anti-p21ras single chain antibodies in the cytoplasm of Xenopus laevis oocytes leads to the inhibition of the insulin-induced meiotic maturation. This finding represents the first successful application of the strategy of intracellular antibodies to block a complex biological process in the cytosol of vertebrate cells.

Animals↗
PubMed1993

Transgenic plants expressing a functional single-chain Fv antibody are specifically protected from virus attack.

Expression of viral genes in transgenic plants is a very effective tool for attenuating plant viral infection. Nevertheless, the lack of generality and risk issues related to the expression of viral genes in plants might limit the exploitation of this strategy. Expression in plants of antibodies against essential viral proteins could provide an alternative approach to engineer viral resistance. Recently, expression of complete or engineered antibodies has been successfully achieved in plants. The engineered single-chain Fv antibody scFv (refs 10, 11) is particularly suitable for expression in plants because of its small size and the lack of assembly requirements. Here we present evidence that constitutive expression in transgenic plants of a scFv antibody, directed against the plant icosahedral tombusvirus artichoke mottled crinkle virus, causes reduction of infection incidence and delay in symptom development.

Antibodies, Viral↗
PubMed1993

Single-channel properties of cloned cGMP-activated channels from retinal rods.

Single-channel properties of a cloned channel activated by cyclic GMP have been analysed. The mRNA encoding for the channel was injected into oocytes of Xenopus laevis and the current flowing through a single ionic channel activated by cGMP was studied in excised patches under voltage-clamp conditions. The ionic channel activated by cGMP had a single-channel conductance of 32 +/- 2 pS at +120 mV and 25 +/- 4 pS at -120 mV, and its conductance was not significantly affected by increasing the cGMP concentration from 20 microM to 200 microM. The single-channel currents in the presence of NH+4, Na+, K+, Li+ and Rb+ in the medium bathing the cytoplasmic side of the membrane at +140 mV were 5.3, 4.7, 3.8, 1.3 and 0.8 pA, respectively. The single-channel current in the presence of Cs+ was less than 0.5 pA. Ca2+ and Mg2+ (both 0.5 mM) in the presence of 100 microM cGMP did not appreciably affect the channel activity at membrane potentials more negative than -80 mV, whereas at +100 mV they reduced the single-channel conductance by about threefold. The ionic selectivity and the blockage by divalent cations of the native channel found in amphibian rods and in the cloned channel from bovine rods are quite similar. However, the cloned channel has well-resolved openings, especially at positive membrane voltages, whereas the native channel is characterized by a continuous flickering between the open and closed state.

Animals↗
PubMed1993

Cloning and expression of an anti-nerve growth factor (NGF) antibody for studies using the neuroantibody approach.

1. The neuroantibody approach, based on the expression of selected monoclonal antibodies by cells of the nervous system, has recently been described (Cattaneo and Neuberger, 1987; Piccioli et al., 1991). In order to apply this experimental strategy to study the role of nerve growth factor (NGF) in the central nervous system (CNS), we exploited the monoclonal antibody (mAb), alpha D11, which neutralizes very efficiently the biological activity of NGF, both in vitro and in vivo (Cattaneo et al., 1988). 2. The alpha D11 antibody chains were cloned and expressed in COS cells as rat/human chimaeric proteins. The cloned antibody was shown to display all the properties of the parental alpha D11 antibody, including its ability to neutralize NGF biological activity. 3. This will allow us to engineer the expression of recombinant alpha D11 antibodies in the CNS, to study the role of NGF in the developing and adult nervous system. This approach can be extended to other neurotrophic factors for which neutralizing monoclonal antibodies are available.

Amino Acid Sequence↗
PubMed1993

MRI and cognitive patterns in relapsing-remitting multiple sclerosis.

We studied the relationships between magnetic resonance imaging (MRI) and the Luria-Nebraska Neuropsychological Battery (LNNB) in 64 patients with relapsing-remitting multiple sclerosis (MS). MRI films were scored according to arbitrary descriptive criteria designed to emphasize patterns of alterations. Five groups were created: group 1 and 2 had typical discrete white matter lesions, group 3 had confluent lesions, group 4 had large discrete lesions and group 5 had only few small lesions. In addition, groups 2 and 3 had evidence of parenchymal atrophy. Groups 2 and 3 were the most impaired on the LNNB, but none of these patients was actually demented. Groups 1 and 5 were globally intact in spite of very different mean age and MRI pattern. Group 4 was composed of younger subjects with a shorter disease duration; they showed mild loss of attentive and abstracting abilities. We suggest that since their MRI was showing greater signs of local biological activity their mental deficits may be a transitory condition capable of two distinct outcomes: a favorable one as in groups 1 and 5, and a slowly progressive one associated with loss of brain tissue as in groups 2 and 3.

Adolescent↗
PubMed1993

Use of living columns to select specific phage antibodies.

Here we demonstrate that it is possible to confront two recombinant microorganisms in order to select one using the other. We have shown that an epitope derived from p21ras expressed within the outer membrane protein, LamB, can be recognized both by the monoclonal antibody Y13-259, as well as the single chain Fv fragment derived from it. This specificity, which is maintained when the Y13-259 single chain Fv is expressed as a fusion protein with the phage fd gene 3 protein, has allowed us to use the living column of LamB-ras to purify Y13-259 phage from a background of non-binding phage, even at dilutions as high as 10 phage in 10(10) irrelevant phage.

Antibodies, Monoclonal↗
PubMed1993

Expression of TRK-T1 oncogene induces differentiation of PC12 cells.

The TRK-T1 oncogene, isolated from a human thyroid carcinoma, represents a rearranged form of the high affinity nerve growth factor (NGF) receptor encoded by the NTRK1 gene; it is created by an intrachromosomal rearrangement fusing the NTRK1 tyrosine kinase domain to the 5' portion of the TPR gene. We have investigated the effect of the TRK-T1 oncogene in PC12 cells, a model system for studying neuronal differentiation and the mechanism of action of NGF. Here, we report that, in PC12 cells, the TRK-T1 oncogene has a differentiating effect that resembles that of NGF and requires the phosphorylation of the oncoprotein. Our results are consistent with the hypothesis that TRK-T1, as well as the original TRK oncogene, induces PC12 differentiation by mimicking the action of NGF bound to its receptor.

Animals↗
PubMed1993

Clinical and histologic effects of topical treatments of vulval lichen sclerosus. A critical evaluation.

A randomized study was conducted on 79 patients with vulval lichen sclerosus who were treated for three months with four topical drugs including testosterone (2%), progesterone (2%), clobetasol propionate (.05%) and a cream based preparation. To evaluate the efficacy of the treatments, patients were examined before and after therapy for symptoms, gross appearance of the lesions and histopathologic features. Patients treated with clobetasol had a better response than responses recorded in the other groups. Remission of symptoms occurred in 75% of patients treated with clobetasol compared to 20% treated with testosterone, 10% treated with progesterone and 10% treated with a cream based preparation. The clobetasol group was the only group with gross changes and histologic evaluations before and after treatment, that showed a highly significant difference (P < .001). In a condition characterized by epidermal atrophy, we observed a significant reduction in epidermal atrophy after treatment. This study suggests that clobetasol propionate (.05%) (a very potent topical steroid) is the therapy of choice in vulval lichen sclerosus.

Administration, Topical↗
PubMed1992

Plasma alpha-melanocyte-stimulating hormone, beta-endorphin, met-enkephalin, and natural killer cell activity in vitiligo.

BACKGROUND: The immune system is important in the pathogenesis of vitiligo, and emotional stress has precipitated vitiligo in some patients. Opioid peptides, beta-endorphin, met-enkephalin, and alpha-melanocyte-stimulating hormone (MSH) act as immunomodulators, and their secretion increases during periods of stress. OBJECTIVE: To see whether these three neuropeptides might be related to vitiligo itself or to some alterations of the immune system in patients with vitiligo, we compared circadian variations in their plasma concentrations and natural killer cell activity of peripheral blood lymphocytes in 14 patients with vitiligo with those of 12 healthy subjects. METHODS: Plasma concentrations of neurohormones were evaluated by radioimmunoassay (immunoradiometric assay for beta-endorphin). Natural killer cell activity (NKCA) was assayed against K562 cells by 51Cr release technique. Data were compared by the Student t test and analyzed by cosinor analysis. RESULTS: The NKCA in vitiligo patients was higher than in controls but had similar circadian rhythm. alpha-MSH had no circadian rhythm in controls or in patients; plasma alpha-MSH levels were the same. Daily met-enkephalin and beta-endorphin oscillations in patients were no longer circadian. beta-Endorphin plasma levels in stable vitiligo were higher than in controls. There were no differences between patients with active vitiligo and normal subjects. Met-enkephalin plasma levels were generally higher in vitiligo patients, especially in the one with active vitiligo, than in controls. CONCLUSION: In vitiligo there are aberrations in neuropeptide, beta-endorphin, and met-enkephalin secretion. The plasma met-enkephalin level is positively correlated with the aggressiveness of the disease.

Adult↗
PubMed1992

[Solitary perforated diverticulum of the right colon. Five cases].

Solitary perforated diverticulum of the right colon is a very uncommon acute disease in emergency surgery, and usually a preoperative diagnosis of acute appendicitis is performed. Five cases of solitary perforated diverticulum of the right colon are presented. Preoperative diagnostic difficulties as well as surgical procedures are discussed.

Adult↗
PubMed1992

[Clobetasol vs. testosterone in the treatment of lichen sclerosus of the vulvar region].

The paper describes a study carried out in 40 patients affected by lichen sclerosus (LS) of the vulva. The mean age of patients was 60.9 years (range 27-83) and 31 were in menopause. Patients were divided randomly into two groups of 20. The symptoms (itching, burning, pain, dyspareunia), clinical aspects (atrophy, hyperkeratosis, sclerosis) and histological alterations (atrophy of the epithelium, edema, inflammatory infiltrate, fibrosis) were quantified in each patient by a score. The mean scores relating to the three parameters examined were then calculated for each group. One group was treated with testosterone propionate 2% and the other with a strong synthetic corticosteroid, clobetasol dipropionate 0.05%. After 24 weeks of treatment patients were again evaluated in relation to clinical (symptoms and clinical aspects) and histological parameters, following the procedure used before the start of treatment. The mean scores obtained were then compared with those before the start of treatment. Statistical analyses were performed using Student's t-test. Testosterone was found to be effective in relation to symptoms but no significant change was observed in relation to clinical aspects and histological alterations. It also caused major secondary effects which led to the suspension of treatment in one patient. Clobetasol was shown to be highly effective both in relation to symptoms and in terms of clinical aspects and histological alterations, and did not cause any noteworthy collateral effects, especially contact dermatitis. In the context of the objective parameters examined in this study, sclerosis and hyperkeratosis were easily modified by corticosteroid treatment in comparison to atrophy, especially in those patients with a longer duration of disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

A recombinant cell line expressing a form of the Y13-259 anti-p21ras antibody which binds protein A and may be produced as ascites.

We have recently reported the molecular cloning of the immunoglobulin genes encoding the variable regions of the rat anti-p21ras antibody, Y13-259. These genes were reassembled into expression vectors supplying DNA sequences encoding human gamma 1 and kappa constant domains, as well as the leader sequence for antibody secretion, thus yielding Hu-Y13-259, a secretory anti-p21ras antibody containing human constant regions. We now report the creation of a recombinant cell line, NS0/Hu-Y13-259/B6, secreting high levels of the Hu-Y13-259 Ig. The antigen specificity of this recombinant antibody was demonstrated to be identical to that of the parental Y13-259, i.e. the amino acid sequence 60-76 of the p21ras protein. Unlike the parental cell line, the recombinant cells could be grown as ascites in mice, allowing the production of large quantities of the protein A-binding Hu-Y13-259 antibody.

Animals↗