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P Poncet

Publications and source records attributed to P Poncet.

At least 55 records · Page 3Linked to original sources
PubMed1986

Autoantibodies against bromelainized mouse erythrocyte: strain distribution of serum idiotype expression and relative peritoneal cell activity.

Previously, we demonstrated that the naturally occurring mouse autoantibodies directed against bromelainized mouse red blood cells (BrMRBC) comprised a family of structurally related molecules bearing a common idiotypic determinant (CP) based on structural and idiotypic analysis of a series of anti-BrMRBC monoclonal autoantibodies derived from a fusion of peritoneal cells (PerC) with plasmacytomas. In the present studies, we have evaluated the quantitative expression of circulating CP idiotype related to autoantibodies against BrMRBC in relation to specific PerC anti-BrMRBC plaque-forming activity in an individual mouse of different strains. The data presented here show no direct relationship between serum CP idiotype expression and PerC anti-BrMRBC plaque-forming activity in an individual mouse of all strains tested. However, the circulating CP idiotype content is higher in strains, viz., CBA/J, NZB, C3H, BXSB, and Biozzi high responder (H) mice which exhibit a high perC autoantibody secretory activity against BrMRBC. The strains such as BALB/c, DBA2, SJL/J, CBA/N, and Biozzi low responder (L) express little or no circulating CP idiotype with a corresponding small or no PerC anti-BrMRBC activity. Furthermore, the PerC "auto"-immune phenomenon is markedly expressed in the normal CBA/J strain since these mice show a higher percentage ratio of CP idiotype over serum IgM (2.68%) as well as highest PerC anti-BrMRBC plaque-forming activity (11,319 +/- 18,029 plaques per million viable cells) compared to other normal and autoimmune strains tested. Nevertheless, the highest circulating serum CP idiotype (49.4 micrograms/ml) is observed in the autoimmune NZB mouse. The immunodeficient CBA/N mice fail to express detectable levels of CP idiotype in their serum. The experiments conducted in genetically selected outbred Biozzi (H and L) strain have revealed remarkable differences in serum CP idiotype expression as well as PerC anti-BrMRBC plaque-forming activity in these two lines. The expression of mouse PerC "auto"-immune phenomenon and quantitative circulation of CP idiotype in the serum seem to be related to regulatory mechanisms as for sheep erythrocytes and other natural antigens earlier demonstrated to be under polygenic regulation in Biozzi (H and L) mice.

Animals↗
PubMed1986

Newborn Xid mice carry the genetic information for the production of natural autoantibodies against DNA, cytoskeletal proteins, and TNP.

Spleen cells from 6-day-old unimmunized male and female (CBA/N X BALB/c)F1 mice, fused with the nonsecreting hybrid SP2/0, gave 184 hybrids secreting immunoglobulins (183 IgM class; 115 from males and 69 from females) which were screened for antibody (Ab) activity against actin, tubulin, myosin, TNP-BSA, dsDNA, and denatured DNA. Eleven hybrids from the male series (9.65%) and eight hybrids from the female series (11.55%) secreted immunoglobulins with significant Ab activity against at least one of the six antigens tested. Four of these clones reacted with a single antigen, while 15 others reacted simultaneously with at least two antigens. Three hybrid clones exhibited Ab activity against all of the antigens tested. The monoclonality and specificity of the immunoglobulins from tissue culture supernatants were respectively assessed by two-dimensional gel electrophoresis after biosynthetic labeling and competitive enzyme-linked immunosorbent assay. These results confirm our previous findings with newborn and adult BALB/c mice, demonstrating a high frequency of this auto-Ab repertoire, especially in newborn mice, and widespread polyspecificity found among these natural auto-Ab. Xid mice are characterized by the absence of a Lyb-3+,5+ B cell population; nevertheless, these studies suggest--but do not prove--that the Lyb-3-,5- lymphocyte population seems to carry genetic information for the production of natural auto-Ab, because no marked differences were observed in the secretory patterns of hybrids obtained from male mice bearing the Xid defect and from normal female mice. Hence, we postulate that the Xid gene might be a regulatory gene because Xid mice, in contrast with normal mice, are unable to secrete anti-DNA auto-Ab on mitogenic stimulation, despite carrying the genetic information.

Animals↗
PubMed1985

Monoclonal autoantibodies against mouse red blood cells: a family of structurally restricted molecules.

Cultured mouse peritoneal cells from unstimulated mice developed plaque-forming activity against isologous bromelain-treated erythrocytes. Several IgM monoclonal autoantibodies obtained by fusion of peritoneal cells from NZB or CBA origin with BALB/c myeloma cells were purified by affinity chromatography on trimethyl ammonium (TMA) column on the basis of their cross-reactivity with TMA, phosphorylcholine (PC) or choline haptens. Binding affinity for PC hapten was of the order of 10(3) M-1. Idiotypic studies with a polyclonal rabbit anti-idiotypic reagent revealed strong cross-reactions with all hybridoma autoantibodies thus far tested. In addition, the rabbit anti-idiotypic serum detected idiotypes or cross-reactive idiotypes in the sera of NZB and CBA as well as BALB/c mice. N-terminal amino acid sequence analyses of three hybridoma autoantibodies from NZB mice and one from CBA mice were carried out. The sequences of the first 32 residues of the four heavy chains showed that three were identical while one had one amino acid interchange; they belong to the VHIII-subgroup. The light chains were identical in the first 35 residues with the exception of a substitution at position 3 in two light chains and are members of the VK-9-subgroup. These results entirely support the idiotypic data. These monoclonal autoantibodies from NZB and CBA mice although isolated and eluted from PC-related haptens do not have any apparent structural nor idiotypic relationship to PC-specific antibodies. Idiotypic and V-region N-terminal sequence data suggest that these autoantibodies constitute a highly restricted family of molecules likely to be encoded by unique germ-line genes which may be expressed as such or as somatic variants in different mouse strains.

Aging↗
PubMed1983

[Epithelioma of the lacrimal sac. Review of the literature and analysis of 8 cases].

Eight patients with lacrimal sac epitheliomas are reported and the published literature reviewed. Clinical signs of these very particular type of tumor are described, as well as their method of extension to the upper facial region which has now been perfectly documented by computed tomography images. Papillomatous forms are relatively frequent, progression of the tumors is slow, and the prognosis for recurrences is fairly good if extensive surgery has been applied.

Adult↗
PubMed1983

[Agenesis of the ear: analytical study. Apropos of 150 cases].

Congenital malformations and agenesis of the ear can affect the external and middle ears, while internal ear structures are generally spared. The malformations may be of different degrees but two stages are usually distinguished. Major agenesis involves malformations of the pinna with absence of the canal and severe middle ear lesions, while in minor agenesis the external ear is only slightly affected or is normal, but is associated with malformations of the auditory ossicula and the walls of the tympanic cavity. The difficulty in deciding on therapy and the extreme variability of results from one case to another explains the wide divergence of opinions of different authors. Three factors are of importance to ensure effective treatment : as early as possible detection, determination of suitability for operation by a complete investigation, and language teaching, a major problem in bilateral agenesis, by means of a hearing-aid initially, followed by surgery.

Ear↗
PubMed1983

[Rare benign tumors of the nasal fossae and sinuses of the face (benign schwannoma, fibromyxoma].

The authors report the observation of two cases of benign schwannomas, one in the nasal cavities, the other in the maxillary sinus and a case of odontogenous fibromyxoma of the ethmoïdo-maxillary sinus. After a study of the observations, a literature review determines the benign character of these tumours, the possibilities of recurring in case of incomplete operation, the importance of computerized tomography to precise their extension, the histological difficulty of the diagnosis and the importance of ultrastructural study to identify them. Taking the cases of schwannomas, we settle two forms A and B (ie) Antoni, because of the myxoïde degeneration which predominate in the second type. Concerning the fibromyxomas histochemicals and ultrastructural studies allow us to definite the character of "myxoblast" or "fibroblast", Cells. Treatment of these lesions is essentially surgical and a long term prognosis is favourable.

Adult↗
PubMed1982

Relationship between choline derivatives and mouse erythrocyte membrane antigens revealed by mouse monoclonal antibodies. I. Anticholine activity of anti-mouse erythrocyte monoclonal antibodies.

Different clones of mouse hybridomas, derived from the fusion of unstimulated mouse peritoneal cells with mouse myeloma cells, producing IgM monoclonal antibodies directed against the membrane of bromelain-treated mouse erythrocytes (MRBC(Br)) have been previously established. We have recently shown that one of these hybridomas produce, in ascites, antibodies cross-reacting with phosphorylcholine derivatives (trimethylammonium (TMA) derivatives). In this work the cross-reactivity for TMA derivatives of the monoclonal antibodies produced by 4 anti-MRBC(Br) hybridomas have been studied at the cell level (plaque-forming cells). Phosphorylcholine, choline bromide and p-aminophenyl-trimethylammonium were found to be potent specific inhibitors of plaque formation (anti MRBC(Br)). The hemolytic activities of ascites and tissue culture supernatants were studied and their inhibition by TMA derivatives was determined. Immunoglobulins from ascites purified on TMA immunoadsorbent column were analyzed by two-dimensional gel electrophoresis, their spectrotype was compared to the spectrotype of immunoglobulins from tissue culture supernatants from the same hybridoma radioactively tagged by internal incorporation of [14C]leucine. It could be shown without ambiguity that the PTMA column retained an IgM with the same characteristics as the IgM secreted in vitro.

Animals↗
PubMed1981

[Radiotherapy in cases of tumours glomus jugulare (author's transl)].

Eight cases of glomus jugulare tumours were irradiated with megavoltage from 1964 through 1978. All had extensive bone destruction of the base of skull 5 000 to 6 000 rads in 7 of the cases. Regression of functional signs was constant whereas regression of palsies was rare and recalcification of bone lesions exceptional. All patients are living with apparent control of disease for periods of 16 to ç years. Accurate technique is indispensible to prevent radiation myelitis. For the extensive jugulare tumours results of radiotherapy compare very favorably with those of extensive surgery.

Adult↗
PubMed1977

[Initial results of a simple immunological study of E.N.T. carcinomas (author's transl)].

45 patients suffering from carcinomas of the upper airway and digestive tract were studied from an immunological standpoint, by estimation of serum immunoglobulins and by a series of skin tests. This latter technique gave the most interesting results. It showed that immunodepression is statistically more frequent in extensive forms and that the prognosis in immunodepressed patients is much more severe than in those who have retained normal immune reactions.

Cobalt Radioisotopes↗
PubMed1977

[Primary coblat therapy and secondary surgery for supra-glottal carcinoma (author's transl)].

This statistical study concerned 218 carcinomas of the laryngeal vestibule and margin treated at the Curie Foundation between 1958 and 1967, by primary cobalt therapy followed when necessary by secondary total laryngectomy. It shows that cobalt therapy alone gives excellent results in early forms (T1 and T2) even in the presence of N1 or N2 nodes. By contrast, the proportion of cures is much lower in T3 and T4 forms. Secondary total laryngectomy was used in only 25 cases out of 127 failures. The postoperative course was often difficult (4 fatal complications and 3 pharyngostomies) but 7 of the patients were cured at 5 years. The use of a surgical technique with minimal trauma and in particular respecting the integrity of the carotid gutters has been associated, in a more recent series, with a notable improvement in the results obtained (one cure out of 2 at 3 years).

Cobalt Radioisotopes↗
PubMed1975

[Remote prognosis in esthesioneuromas (apropos of 11 cases)].

Research was carried out into a group of 11 patients with tumours of the olfactory placode or aesthesioneuromas observed and treated by the authors (10 of them unpublished cases). The authors recall the histological characteristics which, theoretically, distinguish aesthesioneuroepithelioma from aesthesioneurocytoma and aesthesioneuroblastoma and the risk of mistaken interpretation due to confusion with other types of tumour. The following conclusions emerged from this research : 1) Aesthesioneuroma is indisputably a radiosensitive tumour as has been proved by the long-term cures obtained either by irradiation alone or by irradiation after incomplete surgery. 2) However it is exceptional for diagnosis to be made merely by intranasal biopsy. In all doubtful cases, surgical investigation is necessary. This requires a broad para-latero nasal approach route which is the only one affording accurate anatomical localisation of the lesions and complete ablation of the tumour including, where necessary, removal of the lamina cribrosa.

Adolescent↗