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Biomedical subjects

A Cattaneo

Publications and source records attributed to A Cattaneo.

At least 145 records · Page 8Linked to original sources
PubMed1991

Neuroantibodies: molecular cloning of a monoclonal antibody against substance P for expression in the central nervous system.

We present a strategy to study functional and/or developmental processes occurring in the nervous system, as well as in other systems, of mice. This strategy is based on the local expression of specific monoclonal antibodies (mAbs) by cells of the nervous system. As an application of this strategy, we report the cloning of the anti-substance P rat mAb NC1/34HL. Functional substance P-binding antibodies were reconstituted from the cloned variable domains by using vectors for expression in myeloma cells. With these and other vectors a general system for the cloning and expression of mAbs under a series of promoters (of the rat VGF8a gene, the neurofilament light-chain gene, and the methallothionein gene) has been created. The activity of these plasmids was confirmed by expressing the recombinant NC1/34HL mAb in GH3 pituitary cells, PC12 pheochromocytoma cells, and COS cells. DNA from the described constructs can be used to target the expression of the NC1/34HL mAb to the central nervous system of transgenic mice. This procedure will allow us to perturb substance P activity in a controlled way in order to dissect its multiple roles.

Amino Acid Sequence↗
PubMed1991

'Phytoantibodies': a general vector for the expression of immunoglobulin domains in transgenic plants.

Sequences encoding the immunoglobulin heavy-chain variable (VH) domains were engineered in a new general purpose vector to transform plants via Agrobacterium. The expression of an isolated VH domain (IVD) after introduction into the plant genome has been monitored by northern, western and immunohistochemical analysis. Immunoblotting showed that the polypeptide was stably expressed and accounted for up to 1% of the soluble protein fraction. It is therefore proposed that single immunoglobulin domains of suitable specificity expressed in plants may constitute an effective system to inhibit the activity of molecules involved in plant pathology or plant development.

Agrobacterium tumefaciens↗
PubMed1991

Immunohistologic evaluation of the effect of cyclosporine treatment on the lichen planus immune infiltrate.

We have investigated immunohistologically the cutaneous immune infiltrate in the lesions of five patients with severe, extensive lichen planus of recent onset before and after 15 days of oral, low-dose cyclosporine therapy (3 mg/kg/day). Before therapy, we observed an abnormal bandlike cellular infiltrate localized in the papillary dermis, composed mostly of CD3+ cells, with a prevalence of CD4+ cells. Infiltrating lymphocytes showed markers of activation (HLA-DR antigens and interleukin 2 receptor), and there were many Langerhans (CD1+) cells in the dermal infiltrate. After 15 days of cyclosporine therapy, we observed a dramatic decrease in the total number of T cells and a corresponding decrease in interleukin 2 receptor-positive activated CD25+ cells and in antigen-presenting cells (CD1+ and CD14b+). These changes were concurrent with clinical improvement. Our results are compatible with the hypothesis that the inhibition of CD4 T cells by cyclosporine might explain the drug's therapeutic action and that the interaction between antigen-presenting cells and CD4 T cells is important in the pathogenesis of lichen planus.

Adult↗
PubMed1991

Immunohistochemical evidence of skin immune system involvement in vulvar lichen sclerosus et atrophicus.

Biopsies taken from vulvar lesions in 12 women affected by vulvar lichen sclerosus et atrophicus (LSA) have been processed for immunohistological study. Activated (HLA-Dr+) T cells, associated with CD1a+ accessory cells, were found in the dermis in all cases, with architectural patterns varying in relation to the histological phase (early, well developed, old) of the lesion. Interestingly, the number of epidermal CD1a+ Langerhans cells (LCs) was increased in all cases, without any correlation with the amount of the dermal infiltrate and with the histological phase of the lesions. In fact, also in old lesions the number of epidermal CD1a+ LCs was increased, and the sparse dermal lymphoid cells showed a persistent HLA-Dr antigen expression. These data, indicating the persistent activation of epidermal antigen-presenting cells and lymphoid cells in all the evolutive phases of vulvar LSA, suggest a possible involvement of the skin immune system in the pathogenesis of LSA.

Adolescent↗
PubMed1991

Lichen sclerosus and squamous hyperplasia of the vulva. A clinical study of medical treatment.

One hundred thirty-eight cases of nonneoplastic epithelial disorders of the vulva treated with medical therapy from 1984 to 1988 were evaluated at the University of Florence, Florence, Italy. The 67 cases of lichen sclerosus were treated with testosterone propionate or progesterone ointment for 32 weeks. The 31 cases of squamous hyperplasia were treated with corticosteroid ointment for 16 weeks. The 40 patients with lichen sclerosus associated with squamous hyperplasia were treated with corticosteroid ointment for 12 weeks and then with testosterone propionate ointment for another 20. To evaluate the efficacy of the treatments, the patients were examined before and after therapy. The evaluation took into account the symptoms and gross appearance of the lesions, which were given a score of 1-3. Considering all the cases evaluated, a total regression of symptoms occurred in 82 patients (59.4%), while a partial regression occurred in 37 (26.8%). Furthermore, there was a total regression of gross changes in 68 cases (49.3%) and a partial one in 43 (31.1%). The best results were obtained with squamous hyperplasia, which lichen sclerosus, alone or associated with squamous hyperplasia, yielded less successful results.

Adolescent↗
PubMed1990

Intracellular immunization. Cloning and intracellular expression of a monoclonal antibody to the p21ras protein.

Following the demonstration that intracellular expression of antibodies ('intracellular immunization') may be utilized to engineer new traits in mammalian cells, we undertook experiments to perturb the function of p21ras proteins, by engineering the intracellular expression of the anti-p21ras antibody Y13-259. The variable regions of this antibody have been cloned and, after verifying their antigen binding activity, expressed in general purpose vectors for the intracellular expression of antibodies. The results confirmed that the cloned antibody has been efficiently expressed both in the secretory and the intracellular forms. Thus, intracellular immunization of mammalian cells against p21ras, or any other antigen for which a monoclonal antibody is available, can now be performed.

Amino Acid Sequence↗
PubMed1990

Expression and targeting of intracellular antibodies in mammalian cells.

Genes encoding the heavy and light chains of a hapten-specific IgM antibody were modified by site-directed mutagenesis to destroy the hydrophobic leader sequences and allow expression in the cytoplasm of non-lymphoid cells. The in situ assembly of the mutant heavy and light chains was tested in transfected cell lines by immunofluorescence using anti-idiotypic antibodies. A positive diffuse cytoplasmic staining was observed. This demonstrated that the antibody polypeptide chains could assemble in the cell cytoplasm and led us to ask whether antibodies could be further targeted to the nucleus. Mutations were therefore made in which the leader sequence of the light chain was replaced by the nuclear localization signal of the SV40 large T antigen. Transfectants in which the heavy chain lacking the hydrophobic leader was expressed together with a light chain carrying the nuclear localization signal were selected and a nuclear distribution of the assembled antibody was found. Thus, it should prove possible to target a specific antibody to the cell nucleus with the aim of interfering with the function of a nuclear antigen.

Amino Acid Sequence↗
PubMed1990

Immunohistological evaluation of basal cell carcinoma immunoinfiltrate during intralesional treatment with alpha 2-interferon.

We investigated the peritumoral and intratumoral immune infiltrate in 6 basal cell carcinomas (BCCs) treated with recombinant alpha 2b-interferon. Each BCC was injected intralesionally three times a week for 3 weeks with 1.5 x 10(6) IU of interferon per injection (total dose 13.5 x 10(6) IU). The immunohistological study was done before the start of interferon therapy and 15 days afterwards, using a series of monoclonal antibodies and an immunocytochemical technique. Before therapy the infiltrate consisted mainly of CD3+ (T) cells, with prevalence of CD4+ (helper/inducer) T cells. The percentage of T cells expressing interleukin-2 receptor (CD25+ cells) was higher in the tumor nests than in the peritumoral infiltrate (20% and 11% respectively). CD1+ (Langerhans) cells and CD14b+ cells (monocytes/macrophages) were present in the peritumoral infiltrate in all cases (9% +/- 5% and 14% +/- 7% respectively). Very few CD56+ (natural killer), CD15+ (granulocytes) and CD20+ (B) cells were observed in the peritumoral infiltrate and none at all in tumor nests. After 15 days of interferon therapy, we observed an increase in peritumoral and intratumoral CD4+ cells. There was a decrease in the number of CD25+ cells and of CD1+ cells in the peritumoral infiltrate. The number of intratumoral CD25+ increased. No variations were seen in CD14b, CD15, CD20, and CD56 positive cells. Eight weeks after completion of therapy, two BCCs were cleared and the remaining four showed clinical and histological improvement. These results may indicate a direct effect of interferon against BCC; in addition the immunohistological findings suggest that intralesional interferon enhances T cell mediated immune response, especially in tumor nests.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

T cell subpopulations in vitiligo: a chronobiologic study.

The circadian rhythms of helper (CD4) and suppressor (CD8) T cells from the peripheral blood of 12 vitiligo patients (seven with active disease, five with static) and 12 healthy control subjects were studied. Patients with active vitiligo had a lower percentage of CD4+ cells than did control subjects at 0000 hours and at 0600 and 1200 hours; there were no differences between these values in patients with static vitiligo and those in control subjects. The percentage of CD8+ cells were lower at 1200 and 1800 hours in both active and static vitiligo patients than in control subjects. Cosinor analysis of the CD4+ cells showed a circadian rhythm in static vitiligo, whereas the rhythmicity was lost in active vitiligo. CD8+ cells did not show any circadian rhythm in either active or static vitiligo. Our data show more striking aberrations for T cell subtypes in active vitiligo than in static vitiligo. They suggest that cell-mediated immunity may play a role in the pathogenesis of the disease.

Adolescent↗
PubMed1989

Effectiveness of cyclosporine treatment in severe psoriasis: a clinical and immunologic study.

The effectiveness of low doses of cyclosporine (3 to 5 mg/kg/day) for short-term treatment in 13 patients with severe psoriasis was studied. The psoriasis cleared in 12 of 13 patients within 3 to 4 weeks of treatment, and there was appreciable improvement in the thirteenth patient. No major side effects were observed: two patients showed biochemical evidence of slight transient renal dysfunction and three others had cutaneous infections (two viral and one mycotic). An immunohistologic study showed that the psoriatic plaques contained an infiltrate composed mainly of activated helper T lymphocytes. After 15 days of cyclosporine treatment, CD4+ cells were significantly fewer in the epidermis and dermis, and Langerhans cells were more regularly distributed in the epidermis. Our studies of neutrophil chemotaxis showed that it is not significantly influenced by cyclosporine in vitro but is decreased in vivo.

Adult↗
PubMed1988

The mode of action of nerve growth factor in PC12 cells.

This review deals with the mechanism of nerve growth factor action. In view of the many and diversified effects of this growth factor, and since it could utilize different mechanism(s) in distinct types of cells, we have confined our analysis to the best characterized and more extensively studied target, the clonal cell line PC12. When exposed to NGF in vitro, these neoplastic cells recapitulate the last major steps of neuronal differentiation, i.e., the commitment to become a neuron and the acquisition of the neuronal phenotype. This is characterized by electrically excitable neurites, a display of a highly organized cytoskeleton, and the specific chemical and molecular neuronal properties. These effects are elicited upon the interaction of NGF with a receptor whose gene has been cloned and whose kinetic properties are now relatively well characterized. It is not yet clear, on the contrary, if and which of the several potential second messengers (cAMP, Ca, or phosphoinositides) that undergo marked fluctuations following NGF binding, transduce and amplify the NGF message. Among both the early and late effects of NGF is the modulation of expression of several genes. Some of the products of these genes are mainly restricted to nerve cells and others appear to play a crucial role in regulating the proper assembly of cytoskeletal elements. It is hypothesized that this complex array of chemical, molecular, and ultrastructural changes is triggered by NGF, not through activation of a single pathway, but more likely via combinatorial processes whereby several intracellular signals interplay before the irreversible commitment of becoming a neuron is undertaken.

Animals↗
PubMed1988

Three distinct types of monoclonal antibodies after long-term immunization of rats with mouse nerve growth factor.

This article reports the results of a systematic investigation of the different types of antibodies produced in the course of a long-term immunization of rats with mouse nerve growth factor (NGF). We have characterized three types of monoclonal antibodies, namely: (1) antibodies that bind to NGF and inhibit its binding to target cells and its biological activity in culture (type A); (2) antibodies that bind to and precipitate NGF but do not inhibit its binding to target cells or its biological activity (type B); (3) antibodies that fail to recognize NGF itself, but inhibit nonetheless its binding to target cells (type C). These antibodies bind to an antigen present on NGF target cells and not on rat fibroblasts lacking NGF receptor. They appear thus to be antiidiotypic antibodies directed against the NGF receptor, developed as a consequence of the long-term immunization with NGF.

Animals↗
PubMed1987

[Acute poisoning caused by methemoglobinemia-inducing substances. 6 cases].

Six patients were admitted to intensive care in Lodi Hospital with acute poisoning by substances causing methemoglobinaemia. They were treated with antidotes, purifying substances, blood exchange and symptomatic intensive care. The patients were observed 1-3 hours after ingestion of the poison. Three patients (50%) died. This is in line with reports in the literature given the severity of the poisoning. Three patients recovered completely and without sequelae. The importance of early diagnosis with particular attention to anamnestic data and the peculiar clinical symptoms of this syndrome is emphasised as essential for the prompt treatment required. A new classification for the causes of methemoglobinaemia based on pathogenetic criteria is proposed.

Adult↗