Thiamine-like fibers in the monkey brain: an immunocytochemical study.

The distribution of thiamine-immunoreactive structures was studied in the brain of the monkey using an indirect immunoperoxidase technique. Fibers containing thiamine, but no thiamine-immunoreactive cell bodies, were found. The highest density of fibers containing thiamine was observed in the pulvinar nucleus and in the region extending from the pulvinar nucleus to the caudate nucleus. In the mesencephalon, immunoreactive fibers containing thiamine were only found at rostral level close to the medial lemniscus (at the mesencephalic-diencephalic junction). In the thalamus, the distribution of thiamine-immunoreactive structures was more widespread. Thus, immunoreactive fibers were found in nuclei close to the midline (centrum medianum/parafascicular complex), in the ventrolateral thalamus (medial geniculate nucleus, inferior pulvinar nucleus), and in the dorsolateral thalamus (lateral posterior nucleus, pulvinar nucleus). Finally, in the anterior commissure and in the cerebral cortex a low density immunoreactive fibers was visualized. Thus, in the brainstem, no immunoreactive structures were visualized in the medulla oblongata, pons, or in the medial-caudal mesencephalon, and no immunoreactive fibers were observed in the cerebellum, hypothalamus and in the basal ganglia. The present report describes the first visualization and the morphological characteristics (thick, smooth and short, medium or long in length) of the thiamine-immunoreactive fibers in the primate central nervous system using an antiserum directed against this vitamin. The distribution of thiamine-immunoreactive structures in the monkey brain suggests that this vitamin could be involved in several physiological mechanisms.

Riboflavin-like inmunoreactive fibers in the monkey brain.

Using an antiserum directed against the vitamin riboflavin, we studied the distribution of riboflavin-like immunoreactive structures in the monkey brain. In the mesencephalon, at the level of the mesencephalic-diencephalic junction, single riboflavin-like immunoreactive fibers were observed in its dorsal part, whereas a low density of immunoreactive fibers was found below the surface of the section and close to substantia nigra, and a high density was observed above the substantia nigra and close to the medial geniculate nucleus. In the thalamus, single riboflavin-like immunoreactive fibers were found in the ventral regions of the lateral posterior and the medial geniculate nuclei; a low density in the region located above the medial and lateral geniculate nuclei and a high density in the ventral part of the pulvinar nucleus and in the region extending from this latter to the caudate nucleus. Immunoreactive fibers were not observed in the medulla oblongata, pons, cerebellum, hypothalamus, basal ganglia and cerebral cortex. Moreover, no riboflavin-like immunoreactive cell bodies were observed in the monkey brain. The distribution of riboflavin-like immunoreactive fibers in the monkey suggests that this vitamin could be involved in several physiological mechanisms.

Folic acid in the monkey brain: an immunocytochemical study.

The present report describes the first visualization of folic acid-immunoreactive fibers in the mammalian central nervous system using a highly specific antiserum directed against this vitamin. The distribution of folic acid-immunoreactive structures was studied in the brainstem and thalamus of the monkey using an indirect immunoperoxidase technique. We observed fibers containing folic acid, but no folic acid-immunoreactive cell bodies were found. In the brainstem, no immunoreactive structures were visualized in the medulla oblongata, pons, or in the medial-caudal mesencephalon, since at this location immunoreactive fibers containing folic acid were only found at the rostral level in the dorsolateral mesencephalon (in the mesencephalic-diencephalic junction). In the thalamus, the distribution of folic acid-immunoreactive structures was more widespread. Thus, we found immunoreactive fibers in the midline, in nuclei close to the midline (dorsomedial nucleus, centrum medianum/parafascicular complex), in the ventral region of the thalamus (ventral posteroinferior nucleus, ventral posteromedial nucleus), in the ventrolateral thalamus (medial geniculate nucleus, lateral geniculate nucleus, inferior pulvinar nucleus) and in the dorsolateral thalamus (lateral posterior nucleus, pulvinar nucleus). The highest density of fibers containing folic acid was observed in the dorsolateral mesencephalon and in the pulvinar nucleus. The distribution of folic acid-immunoreactive structures in the monkey brain suggests that this vitamin could be involved in several mechanisms, such as visual, auditory, motor and somatosensorial functions.

Characterisation, cloning and sequencing of a conformation-dependent monoclonal antibody to the alphaIIbbeta3 integrin: interest for use in thrombus detection.

The detection of newly formed thrombi is of primary importance in clinical medicine. The activated platelet is a potential target for the localization of thrombotic lesions in arteries. The integrin alpha(IIb)beta(3) membrane changes conformation upon activation. A novel anti-alpha(IIb)beta(3) monoclonal antibody (MAb), XIIF9, is described which recognizes an epitope whose expression was enhanced by activation. Radioiodinated XIIF9 bound to a single class of sites on the beta(3) subunit, with 13600 +/- 2000 molecules bound per unstimulated platelet and a K(d) of 34.5 nM. Platelets stimulated with 0.5 U/ml of thrombin bound 66000 +/- 4000 molecules/cell (K(d) = 51.6 nM). Moreover, XIIF9 binding to unstimulated platelets could be increased 4-fold by treatment of the alpha(IIb)beta(3) complex with 5 mM EDTA. Thus, XIIF9 recognized an epitope on the beta(3) subunit whose accessibility was increased upon thrombin activation or EDTA treatment. Sequence analysis of the gene segment encoding the XIIF9 heavy chain revealed interesting motifs shared with cyclic CX6-7C anti-alpha(IIb)beta(3) peptides or with AC7, a published MAb specific for activated alpha(IIb)beta(3). In vivo experiments in atherosclerotic rabbits followed by immunohistological analysis, revealed a specific binding of XIIF9 on platelets engaged in thrombus formation, demonstrating real clinical potential for such MAbs in imaging.

Characterization and application of new macroporous membrane ion exchangers.

A new ready-to-use unit for high-performance membrane chromatography has been characterized. Its dynamic capacity, resolving power and protein recovery were measured at different flow-rates. The binding capacity was 0.5-2 mg/cm2 with a 95% recovery at 10 ml/min irrespective of the protein concentration up to 10 mg/ml. For very-high flow-rates (50 and 100 ml/min) the recovery was 90% and 70%. At these flow-rates, the maximum back-pressure was about 0.1 MPa and was independent of the filtration area. By increasing the filtration area, a proportional capacity increase was obtained, indicating an easy scale-up. High flow-rates had only a slight effect on resolution. This new adsorber was able to purify IgM from supernatant of cell culture of a human hybridoma in less than 8 min with a high degree of purity (95%).

Fibrous carbon implants for the maintenance of bone volume after tooth avulsion: first clinical results.

When the avulsion of the last teeth of a patient is necessary, we propose to maintain the bone mass in order to improve the prosthetic conditions. For this purpose, we use fibrous carbon which is a biocompatible material well tolerated by the surrounding tissues. The results are reported of 10 yr of clinical use of fibrous carbon roots implanted in 38 alveoli of 26 patients with a mean follow-up of 34 month. There were 26 accepted artificial roots and 12 failures. The causes of failure are principally: (1) absent external bone wall near implanted alveoli (presence of the four bone walls is necessary); (2) existing local inflammation near implant site area.

Mechanical evaluation of splint therapy in treatment of the edentulous patient.

Many edentulous patients have temporomandibular joint (TMJ) dysfunction that affects the use of their complete dentures. During the diagnostic and treatment-planning phase an ordered series of procedures must be performed. An arbitrary axis mounting, needlepoint and pantographic tracings on stabilized record bases will aid the dentist in determining the functional state of the TMJ and associated muscles. If no pathosis is found, a conventional denture technique can be used. If TMJ dysfunction is noted on the basis of an analysis of the tracings, an interim mandibular denture can be modified to correct the TMJ and musculature before new complete dentures are made. The occlusal scheme chosen for each patient can be based on a careful analysis of the tracings over a period of months.

[Joint and muscular pathology before, during and after treatment of total edentulousness]. / Les pathologies articulaires et musculaires avant, pendant et après les traitements des édentations totales.

Firstly, the author raises the question related to dysfunction of the temporomandibular joint that should not be considered any longer as an epiphenomenon in patients with full dentures. Then he deals with the diagnostic procedures: palpation and measurement of muscular activity, mechanical evaluation of muscular and articular dysfunction. Finally, he describes the therapeutical aspects of bite guards with their specifications.