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Biomedical subjects

J Nolte

Publications and source records attributed to J Nolte.

17 recordsLinked to original sources

The fine structure of the parietal retinas of Anolis carolinensis and Iguana iguana.

An electron microscopic examination of the parietal retinas of Anolis carolinensis and Iguana iguana demonstrated within each retina (1) two distinct populations of neurons, (2) two populations of glia, and (3) a population of photoreceptors which could not be subdivided. A small population of very electron-dense cells, in many respects similar to photoreceptors, was also found in the iguana. Correspondingly dark processes were found in the plexiform layer of each retina. Parietal photoreceptors generally resemble cones of the lateral eye. Glial cells were sub-classified on the basis of the location of their somata and the disposition of their processes. Neurons were identified by virtue of their cytology and their reception of axosomatic ribbon synapses from unidentified plexiform layer processes. Neuronal subtypes were located on opposite sides of the plexiform layer. Neurons distal to that layer were found to project the initial segments of their processes into the plexiform layer parallel to its long axis, while neurons central to the plexiform layer projected axons centrally and dendrites radially into the plexiform layer. The existence of at least two neuronal populations and of interphotoreceptor synapses suggests that photosensory processing within the parietal retina may be more complex than previously assumed.

Animals

Freeze-fracturing studies of mitochondrial myopathy. A correlated clinical, biochemical and morphological investigation.

Freeze-fracture studies of pathologically changed mitochondria in situ from muscle biopsies of a 9.5-year-old girl with a mitochondrial myopathy were correlated with clinical, biochemical and histochemical investigations. In the ultrathin sections giant mitochondria with densely packed cristae membranes - often reoriented to concentric circles - and, in addition, paracrystalline mitochondrial inclusions were found. The freeze fracture faces of such transformed mitochondria and preparations of their inner and outer membranes provided a morphological insight in the macromolecular structure of the mitochondrial membrane under such pathological conditions. The results lead to the hypothesis that part of the transformed mitochondria stay active functionally for an extended period by maintaining the delimitation from the cytoplasm and by preserving the macromolecular membrane architecture. This hypothesis could explain the slow progression of the myogenic symptoms.

Child

[Exercise-induced muscular weakness, myalgia and contractures. II. Casuistic contribution].

Two sisters with exercise-induced myalgias, muscular weakness and contractures are reported. Neurologic and psychiatric findings were normal, nor did electromyography, serum enzymes and ischemic forearm exercise test reveal specific findings. Under the light microscope multiple muscle fibers contained small vacuoles which stained positive with Oil Red O. No further information resulted from histochemical examinations. In the more seriously affected patient morphometric analysis of electronmicrographs showed a tenfold increase of fat content in comparison to normal controls. Alterations in the enzymatic activities could be demonstrated in glycogenolysis, glycolysis and in fat metabolism, but there were no previously described enzyme defects such as phosphorylase deficiency, phosphofructokinase deficiency, phosphohexoisomerase inhibitor, carnitine or carnitine-palmityltransferase deficiency. Myopathy with lactic acidosis, prolonged muscular relaxation due to deficient reabsorption of sarcoplasmic calcium in the tubular system and dyskalemic paralysis can be ruled out on the basis of the clinical signs. This myopathy may be due to an as yet unknown metabolic disturbances.

Adult

The fine structure of the iris of the grass frog, Rana pipiens.

The iris of the grass frog Rana iiens, can respond to light even when isolated from the remainder of the animal. The iris is a three-layered structure, comprising a stromal layer and two layers of pigment epithelium. The sphincter pupillae, which is composed of pigmented smooth muscle cells, is embedded between the two layers of pigment epithelium. There is no dilator pupillae in this species. We have been unable to find any cells or any organelles in the iris which are anatomically specialized for photoreception in any obvious way.

Animals

Influence of serum blocking factors on cancer patients undergoing immunotherapy.

Blocking factors are small polypeptide molecules that may appear in the serum of patients with cancer. These factors block the transformation of lymphocytes in culture to nonspecific mitogens such as phytohemagglutinin or concanavalin A and, therefore, may reflect changes in the immunocompetence of the patient. Blocking factors were monitored during the clinical course of thirty-five patients with cancer. These factors did not develop in patients with response to therapy whereas they did develop in patients without response. A third group of patients without response to therapy after a previous remission showed an absence of lymphocyte responsiveness in culture that was not due to blocking factors, suggesting that immune clone consumption had occurred. Dermal responsiveness to tumor antigen correlated with a favorable clinical course and was usually absent when serum blocking factors were present.

Antibody Formation