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J Roland

Publications and source records attributed to J Roland.

At least 55 records · Page 3Linked to original sources
PubMed1996

The veins of the medulla oblongata: MRI cross-sectional anatomy.

Magnetic resonance imaging (MRI) has progressively become the major or even the only imaging procedure for displaying the vascular relationships of the brainstem in the context of infra-tentorial lesions. In order to assess the MR sectional anatomy of the bulbar vv. 40 normal patients were examined in the MR axial, frontal and sagittal planes after gadolinium i.v. injection. The bulbar venous networks were inconstantly visualised: anterior vv. (16%). posterior (3%), lateral (8%). The vein of the lateral recess of the fourth ventricle was constant in the three planes; the inferior petrosal sinus could be seen in 82% of cases. Their relation with the posterior fossa structures are emphasised and discussed.

Contrast Media↗
PubMed1996

Antibodies to neutrophil elastase: a study in patients with vasculitis.

Whether antibodies to elastase (EL) exist in autoimmune disease is controversial, due in part to inadequate methods used to determine antibody titers. We have developed a highly sensitive and specific enzyme-linked immunosorbent assay, using immobilized EL and mouse monoclonal antibodies for standardization. The specificity of the enzyme-linked immunosorbent assay was confirmed by absorption studies and Western blot analysis. Using this enzyme-linked immunosorbent assay, antibodies to EL were found in antineutrophil cytoplasmic antibody-positive vasculitis patients to a higher degree than reported in the literature (in eight of 108 patients with Wegener's granulomatosis and in 15 of 78 patients with microscopic polyangiitis). Patients with Wegener's granulomatosis or microscopic polyangiitis and antibodies to EL had significantly more severe renal involvement, as indicated by the higher frequency of dialysis dependency. Also in contrast to reported data, antibodies to EL were found less frequently in patients with systemic lupus erythematosus (nine of 64 patients). Binding of systemic lupus erythematosus sera to uncoated plates, giving a nonspecific reaction, was seen quite frequently, which might explain the discrepancy.

Adult↗
PubMed1996

The role of Ly49A and 5E6(Ly49C) molecules in hybrid resistance mediated by murine natural killer cells against normal T cell blasts.

We address the mechanism of hybrid resistance (HR) in vitro using NK effector cells and target lymphoblasts from H-2b, H-2d, and H-2b/d mice. The 5E6 (Ly49C)+ subset of F1 NK cells lyse BALB/c (H-2d) but not B6 (H-2b) targets unless either anti-5E6 or anti-H-2Kb MAbs are present. H-2Dd transgenic B6 (D8) targets are not susceptible to F1 Ly49A+ effectors. Furthermore, 5E6+ Ly49A+ F1 effectors lyse B6 and BALB/c targets only in the presence of anti-5E6 and anti-Ly49A MAbs, respectively. Thus, recognition of H-2Kb by 5E6 and H-2Dd by Ly49A transduce independent inhibitory signals. Moreover, anti-5E6 MAbs enable 5E6+ BALB/c NK cells to lyse (BALB/c x B6)F1 targets. These data support the "missing self" and not the "hemopoietic histocompatibility antigen" hypothesis for HR. In addition, 5E6+ NK cells from BALB/c and BALB.B, but not B6 or (BALB/c x B6)F1, mice receive negative signals from both H-2d and Kb class I antigens. Thus, allelic differences in 5E6 (C57BL versus BALB) may regulate recognition events by NK cells.

Alleles↗
PubMed1996

Generalized bone marrow metastases. High liver uptake on bone marrow immunoscintigraphy associated with extramedullary hematopoiesis.

Increased hepatic uptake and absent bone marrow uptake on bone marrow immunoscintigraphy has been reported after the formation of human antimurine antibodies. A case of generalized bone marrow metastases is presented, in whom an elevated liver uptake on bone marrow immunoscintigraphy proved to be associated with extramedullary hematopoiesis. Extramedullary hematopoiesis should be included as a possible cause of a disproportionately elevated liver uptake on bone marrow immunoscintigraphy, especially on initial studies, or on repeat studies with low human antimurine antibody titers. Tc-99m labeled BW 250/183 immunoscintigraphy may aid in the localization of suspected sites of extramedullary hematopoiesis.

Adult↗
PubMed1996

Exon 2-mediated c-myc mRNA decay in vivo is independent of its translation.

We have previously shown that the steady-state level of c-myc mRNA in vivo is primarily controlled by posttranscriptional regulatory mechanisms. To identify the sequences involved in this process, we constructed a series of H-2/myc transgenic lines in which various regions of the human c-MYC gene were placed under the control of the quasi-ubiquitous H-2K class I regulatory sequences. We demonstrated that the presence of one of the two coding exons, exon 2 or exon 3, is sufficient to confer a level of expression of transgene mRNA similar to that of endogenous c-myc in various adult tissues as well as after partial hepatectomy or after protein synthesis inhibition. We now focus on the molecular mechanisms involved in modulation of expression of mRNAs containing c-myc exon 2 sequences, with special emphasis on the coupling between translation and c-myc mRNA turnover. We have undertaken an analysis of expression, both at the mRNA level and at the protein level, of new transgenic constructs in which the translation is impaired either by disruption of the initiation codon or by addition of stop codons upstream of exon 2. Our results show that the translation of c-myc exon 2 is not required for regulated expression of the transgene in the different situations analyzed, and therefore they indicate that the mRNA destabilizing function of exon 2 is independent of translation by ribosomes. Our investigations also reveal that, in the thymus, some H-2/myc transgenes express high levels of mRNA but low levels of protein. Besides the fact that these results suggest the existence of tissue-specific mechanisms that control c-myc translatability in vivo, they also bring another indication of the uncoupling of c-myc mRNA translation and degradation.

Animals↗
PubMed1996

[Demonstration of the immunoreactivity of polynuclear eosinophils for bombesin and substance P. A new concept of the neuro-immune axis].

Immunoreactivity for B and SP was detected by means of light and electron microscopy (by preembedding immunocytochemistry), in eosiniphilic polymorphonuclear leukocytes infiltrating the connective tissue of gastrointestinal and respiratory tract in mouse, rat and human ; and in human bronchoalveolar lavages in case of hypereosinophilia. This positive reaction depends on the use of an acetic-acid-containing-fixative (minimum 48 hours), and is located in the granules of eosinophils at their membrane level, and on eosinophil plasma membranes. Eosinophil peroxidases (catalases) should not affect the immunocytochemical reaction, since heating during a paraplast embedding and sodium-azide in electron microscopy procedure destroyed these enzymes. The membrane-bound immunoreaction for B and SP, with very close structural similarity, suggested cross-reactivity between the two neuropeptides, with recognition of one or several epitopes by the polyclonal antisera. One of these epitopes is probably associated with the C-terminal sequence of B (with tachykinin-like activity) and seems to be present in other neuropeptides such as SP ; another epitope would be the N-terminal sequence of SP (with bradykinin-like activity). Hence, eosinophils could be the source of tachykinin and bradykinin. Another hypothesis about the membrane immunolocalization (as yet unproved experimentally) would be a cross-reactivity due to recognition of electron-negative charges of membrane phospholipides. Lysophosphatidic acid could play a hormone-like activity and mimic B and SP activities, such as growth factors. Finally, anti-B and anti-SP antisera could contain anti-idiotype antibodies uncovering receptors. In conclusion : eosinophils might produce neuropeptides or neuropeptide-like substances, with, for instance, bronchoconstrictive activity by paracrine control and possible complementarity with nerve endings.

Animals↗
PubMed1995

Allelic exclusion of Ly49-family genes encoding class I MHC-specific receptors on NK cells.

An important feature of natural killer (NK) cell activity is the lysis of cells that have extinguished expression of some or all class I major histocompatibility (MHC) molecules. Accordingly, the Ly49A NK-cell antigen receptor has been shown to deliver an inhibitory signal to NK cells on encounter with Dd or Dk class I MHC on target cells. Ly49A belongs to a family of eight or more highly related, tightly linked genes. Expression of Ly49A and Ly49C, another member of the Ly49 family with distinct MHC specificity, define subpopulations of NK cells that are only partly overlapping. The mechanisms regulating the expression of LY49 family members are unknown. We show here that the Ly49A and Ly49C NK-cell receptors are each subject to allelic exclusion. Because Ly49 genes are not thought to undergo DNA rearrangement, allelic exclusion of Ly49 genes could involve a mechanism distinct from that used by B and T lymphocytes and is likely to play an important role in the genesis of a putative NK-cell repertoire specific for class I molecules.

Alleles↗
PubMed1995

Employment of the anatomical terminology of the Nomina Anatomica in the radiologic literature.

The purpose of this paper was to assess the relationship of the anatomical terms employed in the radiologic literature to the International Nomenclature derived from the Nomina Anatomica. A critical analysis was made of the anatomical terminology employed in three French and two American journals of radiology. In about 40% of the French journals, the International Anatomical Nomenclature was not adhered to, whereas in 50%, there was no difference in the terms encountered between the French traditional terminology and the French adaptation of the Nomina Anatomica. In contrast, a close adherence to the Nomina Anatomica was observed in the two American journals. The exceptions most frequently encountered are detailed. The aim and principles of the Nomina Anatomica, based on the Latin terminology and aimed at clarification and systematisation, are stressed. The advantages of employing the International Anatomical Nomenclature in medical papers, allowing easy understanding by foreign readers in a world of rapid information exchange are highlighted.

Anatomy↗
PubMed1995

Metastases seen on SPECT imaging despite a normal planar bone scan.

Although bone scintigraphy is an extremely sensitive method for the detection of focal bone disease, small lesions below the resolution of planar imaging may be missed. This is a report of a patient with carcinoma of the breast who showed tumor progression 1 year after initial treatment. Complete evaluation was performed in order to detect the origin of increased level of a tumor marker. Although planar bone scintigraphy could not demonstrate any lesion in the spine, multiple metastases were detected in the lumbar and the thoracic spines on SPECT imaging. Only some of these lesions were seen with MRI. Repeat planar bone imaging 6 weeks later showed multiple bone lesions in the lumbar and thoracic areas.

Adenocarcinoma↗
PubMed1995

[The anatomy and the MRI anatomy of the interhemispheric cerebral commissures].

Correlation of myelin-stained or cryotomic sections of human brain with inversion-recovery MR images can display the cerebral commissures as white-matter tracts (in hypersignal on MRI), crossing the mid-line. MRI shows routinely in three orthogonal planes a) the corpus callosum stretched above the supra-tentorial ventricles, it's four portions (rostrum, genu, body and splenium) and connections with the Deep Grey Nuclei b) the fornix, intralimbic commissure joining anteriorly the mammillary bodies (through it's columns) to the alveus posteriorly and inferiorly (via it's two crura), arcing around the thalamus and lying over the hippocampus and the dentate gyrus as shown on the frontal sections c) the anterior commissure, white-matter tract connecting the two temporal lobes. In axial view, the anterior commissure has the shape of bicycle handlebars, coursing posteriorly, inferiorly and laterally behind the head of the caudate nucleus and passes into the lateral nucleus of the globus pallidus into the inferior and middle temporal gyri. Because the anterior commissure is easily recognisable in all planes, it's appears to be a important landmark for identification of the lateral and medial nuclei of the globus pallidus on axial and sagittal planes d) at least, the posterior commissure, anterior margin of the pineal region, closely related to the superior colliculi, acquire a major importance in the AC-PC line delineation becoming a reference landmark for stereotatical procedures.

Brain↗
PubMed1994

Incidence and risk factors for latent sensitization to chymopapain: predictive skin-prick tests in 700 candidates for chemonucleolysis.

Seven hundred patients were investigated prospectively before undergoing chemonucleolysis. A past history of allergy and/or previous exposure to papain, either in food, beverages or drugs, was sought, and a skin-prick test with chymopapain was performed. Based on the results obtained, the subjects were classified into four groups: Group I--225 non-atopic non-papain-exposed subjects; Group II--285 non-atopic papain-exposed subjects; Group III--69 atopic non-papain-exposed subjects; and Group IV--121 atopic papain-exposed subjects. Latent sensitization to papain was observed in 0.4% of subjects in Group I, 3.16% in Group II, 5.8% in Group III and 7.4% in Group IV. The odds ratios were 13.8 for atopy and 7.3 for exposure to papain. Interaction between atopy and papain exposure did not result in a significantly greater risk. Neither sex nor age nor a history of a previous drug reaction were risk factors. Only one patient out of the 23 who were sensitive to papain had no risk factor. The 677 skin-test negative patients then underwent chemonucleolysis and none of them had an anaphylactic reaction. This was significantly less frequent: (P = 0.04) than the incidence in a random population (0.45%). Prick tests performed 6 weeks and 6 months after chemonucleolysis revealed newly acquired sensitization in 36% of the patients. Atopy was not a risk factor for this event.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Production and characterization of polyclonal anti-idiotypic anti-TRH antibodies: application to the study of pituitary TRH receptor.

cDNA encoding the thyrotropin-releasing hormone receptor (TRH-R) was recently cloned in rat pituitary prolactin cells and in mouse thyrotropes. The molecular weights of the protein sequences obtained are 46.6 and 44.5 kD. However, TRH-R has not yet been purified to homogeneity and specific anti-TRH-R antibody could not yet be obtained by classical biochemical methods. We thus attempted to obtain antibodies specific for TRH-R using an anti-idiotypic approach. Rabbits of the same allotype were immunized using Igs (Ab1) extracted from rabbit polyclonal anti-TRH immune serum. Anti-idiotypic rabbit polyclonal anti-anti-TRH antibodies (Ab2) were obtained, as shown by their ability to inhibit the formation of TRH-anti-TRH complexes in a radioimmunoassay system. One of them, the polyclonal Ab2 R38/B12, was tested for its ability to recognize the TRH-R in rat pituitary, tumor-derived, GH3/B6 prolactin-secreting cells. Immunoreactive material was immunocytochemically detected in fixed and saponin-permeabilized GH3/B6 cells. The immunostaining was localized at the plasma membrane and on intracellular structures. It was not observed using non-anti-TRH Ab2 and was abolished in the presence of excess TRH. Furthermore, binding of [125I]R38/B12 on fixed and saponin-permeabilized GH3/B6 cells was partially inhibited by excess TRH. By immunoblot analyses of Triton X-114 cell extracts performed under reducing or nonreducing conditions, the polyclonal R38/B12 Igs revealed two main protein species of approximately 98 and approximately 76 kD as well as several proteins < or = 46 kD. In the presence of excess TRH, the approximately 98- and approximately 42-kD bands were abolished, whereas the intensity of the other bands was faintly attenuated only. The approximately 98-kD protein was also revealed in a two-dimensional PAGE analysis. Nevertheless, the effects of R38/B12 Igs on [3H]TRH binding by GH3/B6 cells and on basal or TRH-induced prolactin secretion were not markedly different from those elicited by control Ab2. These data suggest that we have characterized Ab2 antibodies which recognize a molecular entity that might be related to the TRH-R in GH3B6 cells.

Animals↗
PubMed1994

[Lumbar intervertebral disk. Structure. Knowledge status].

The purpose of this paper is to review the main data on the structure of the intervertebral disc, which are illustrated by personal documents. Applications in understanding the degenerative pathology are highlighted. The nucleus pulposus is the "central" component of the disc, highly hydrophilic, deformable but remaining of constant volume. It can be compared to a hydraulic chamber within the disc, sealed by the annulus fibrosus, which is a dense peripheric ring of concentric fibrous lamellae. The cartilaginous end plates (cranial and caudal) separate the disc from the adjacent subchondral vertebral bone. (Their involvement in the discal metabolism as well as the blood supply of the disc are developed elsewhere (see our companion article)).

Cartilage↗
PubMed1994

[Lumbar intervertebral disk. Intervertebral disk-vertebral body pathways and discal vascularization].

We studied the disco-vertebral interface and the blood supply of the intervertebral disks L3-L4, L4-L5, and L5-S1 of 5 human adult columns. Moreover, in order to investigate the discal vasculature, infusion of Japanese ink was used in 2 other adult columns, as well as immuno-histological methods in the L5-S1 disk of 4 adults and 2 infants. Our study confirms the paucity of discal vasculature in adults, by contrast with that of infants, but shows numerous defects in the subchondral vertebral plate, which are filled by vascularised medullary soft tissue and are in contact with the cartilaginous discal end plate. By these contacts, nutrients could reach the intervertebral disk, as suggested by other works, and as is the case in other cartilaginous structures of the body.

Humans↗
PubMed1994

Venous territories of the brain.

The venous return of the cerebral hemispheres is ensured by two systems. The first, superficial system, reaches the peripheral dural sinuses, i.e. the superior sagittal sinus, the lateral sinus and the cavernous sinus. The second, deep system, corresponds to Galen's vein. Anatomical and angiographic data from the literature enable the usual drainage territory to be defined for each of these collecting vessels. However, the variability of the superficial sylvian vein and the importance of cortical anastomotic vessels make impossible to delimit precisely the territory of each peripheral sinus. The functional role played by numerous centro-peripheral anastomoses is more difficult to assert in each individual. It is therefore probable that in the cerebral hemispheres there is a deep territory balancing the superficial territories.

Cavernous Sinus↗
PubMed1994

Present status of computerized tomography and angiography in the diagnosis of cerebral thrombophlebitis cavernous sinus thrombosis excluded.

In order to evaluate the contribution of computerized tomography (CT) to the diagnosis of cerebral thrombophlebitis, a series of 28 cases was reviewed and compared with data from the literature. In an examination carried out 4 to 5 days of its constitution the thrombus may be directly visualized as a spontaneous hyperdensity. This early but very transient sign, called "cord sign", can easily be overlooked, which explains why it was found in only 5 of our 28 cases and in 2% of the largest series of the literature. The thrombus thereafter becomes hypodense and can be intensified by peripheral contrast enhancement which produces the classical "delta sign". This sign is more frequent: 13/28 in our series and 16 to 30% in published cases. It is usually found in the superior sagittal sinus and must be distinguished from anatomical variations which are common at that level. These two direct signs acquire a greater value when associated with such indirect signs as diffuse or localized cerebral oedema (12 to 52%) and venous ischaemia (22 to 59%). Venous ischaemia is characterized by its strong bleeding potential (more than 50% of the cases) and by its usually favourable course; these two elements and its site differentiate it from arterial ischaemia. Finally, venous stasis is responsible, in 5 to 19% of the cases, for intense enhancement of the tentorium cerebelli; this sign is not specific but easy to evidence and of great value when associated with a direct sign. Dilatation of cortical veins, found in 4 of our 28 cases, also seems to be an interesting sign which, to our knowledge, has not yet been mentioned in the literature. Since in 3.6 to 26% of the cerebral thrombophlebitis the CT scan is normal, a negative CT examination does not rule out this disease, and in many cases the exploration must be rapidly completed by angiography or MRI. Because it is non-invasive and very sensitive to flows, MRI has become the key examination to assert the diagnosis. Angiography is now restricted to those cases where cases where MRI cannot be performed promptly or to certain, purely cortical thrombophlebitis which might pass unnoticed at MRI. When carried out and interpreted cautiously, angiography always shows the venous thrombosis, its exact size and its suppletive network. The results of this study show that MRI alone can diagnose cerebral thrombophlebitis in most patients, that CT well done and interpreted often provides useful but seldom sufficient indices, and that angiography should be reserved for difficult cases.

Cavernous Sinus↗