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Biomedical subjects

J Roland

Publications and source records attributed to J Roland.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

A and b allotypy in Oryctolagus and Lepus species.

It had been previously shown by the description in wild rabbits Oryctolagus cuniculus of unknown allotypic specificities belonging to the a series and the b series, that the genetic polymorphism found in domestic rabbits was only a part of the genetic polymorphism of the species O. cuniculus. To the known a1, a2 and a3 allotypic specificities have been added in the last years a100 and a101 which are under the control of allelic genes at the a locus. Studies of cross-reactivities in the a system is a way to detect variants of a given allotypic specificity. The phylogenetic studies in the hare Lepus capensis demonstrate that a2 and a3 determinants are allotypic, apparently without polymorphism in this species; indeed, all the tested hares have either a2 or a3 determinants or both. Four presumably "new" allotypic specificities of the b series, A93, A94, A95 and A96 have been found in a population of wild rabbits O. cuniculus from an Island in Tunisia. A95 allotypic specificities against which specific antisera have been prepared, shows cross-reactivities with b4, b5 and b6 allotypes of domestic rabbit. Genetic data demonstrate that A95 is indeed under the control of an allele at the b locus. If schematic mechanisms involving duplication and mutations of genes are suitable to understand the presence of variants and their cross-reactivities, one has to understand how so many genes are involved in allotypy and how it remains stable during evolution.

Animals↗
PubMedDate not supplied

[Carcinoid tumors of the rectum. Apropos of 2 cases with metastases].

We are reporting two cases of carcinoid tumors of the rectum treated surgically. In both cases, there were nodes metastases and in one case liver metastases without carcinoid syndrome. Carcinoid tumors of the rectum are rare and usually asymptomatic; metastases are essentially located in the lymph nodes and the liver.

Carcinoid Tumor↗
PubMedDate not supplied

Phylogenic studies on allotypic specificities of rabbit immunoglobulins.

Phylogenic studies of rabbit allotypic specificities are carried out in several lagomorphs. We give the results obtained through the study of hare Lepus capensis immunoglobulins. IgG of all the 140 studied hares exhibit determinants recognized by anti-b4 and anti-b5 immune sera. Most hares, but not all, have determinants recognized by anti-b6 immune sera. Among the determinants recognized by anti-b4 immune sera, some seem to be isotypic (found in all studied hares), others (absent in some hares) are allotypic. Determinants recognized by anti-b5 immune sera behave as isotypic; they are recognized by anti-b5 antibodies which participate to the cross reaction with b6 pattern. Other determinants recognized by anti-b5 antibodies are allotypic. Three allotypic patterns, at least, each made of two determinants, belonging to the same series, have been detected on hare L chains. Two of them are recognized by anti-b6 immune sera; the third is characterized by its lack of determinants cross-reacting with anti-b6 antibodies. It does not seem that L. capensis has any determinant recognized by anti-b9 immune sera. IgG of some but not all hares have determinants recognized by anti-a2 immune sera, only when these have been prepared in rabbits with the phenotype a(1-2-3+).

Animals↗
PubMedDate not supplied

[Blood and bone marrow abnormalities in primary lung cancers (author's transl)].

Blood and bone marrow abnormalities accompanying cancers have been known for a while, without yet being understood. The study of 89 patients having lung cancers leads to the following observations: thrombocytosis is frequent and should be considered as a diagnostic criterion; anemia is often associated and we have noticed a correlation between the two. The bone marrow abnormalities shown on biopsy are also frequent, presenting mainly (54/104) as irritative type. This histological pattern becomes a criterion of prognosis, since one should interpret it as a bone marrow reaction to the implantation of cancerous cells. Lastly, no relationship has been found between the blood count and the bone marrow pattern.

Anemia↗
PubMedDate not supplied

[A probable glucidic allotypic pattern carried by the Fab fragment of rabbit IgG (author's transl)].

An allotypic specificity of rabbit immunoglobulins designated as A90 has been studied. The A90 pattern found on the Fab fragment and gamma chain of IgG, is located on the constant region of the Fd fragment of IgG. Aa+ molecules (which carry a specificity of the a series) and Aa- molecules (which lack the a series specificity) isolated from the same serum carry the A90 pattern. A90 distribution in a given serum has been studied in several IgG fractions separated by DEAE cellulose chromatography; the most negatively charged of equally concentrated IgG fractions has ten times more A90 allotypic concentration than positively charged ones. The gene controlling A90 allotypic concentration than positively charged ones. The gene controlling A90 synthesis is not linked to a genes. The percentage of IgG molecules carrying the A90 pattern decreases with the age of the rabbits. Part of the anti-A90 antibodies combine with human IgG (of different subclasses) as well as with sheep and mouse IgG (among which they do not differentiate). The absence of linkage between A90 and a genes suggests that the A90 pattern has a glucidic part. We discuss this hypothesis, comparing some features of the A90 pattern to those of IgG human allotypic pattern for which a glucidic structure has been proposed.

Aging↗