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Biomedical subjects

T Manabe

Publications and source records attributed to T Manabe.

At least 541 records · Page 30Linked to original sources
PubMed1979

Cholecystokinin/pancreozymin induces the parallel discharge of digestive enzymes from the in vitro rabbit pancreas.

Considerable controversy has surrounded the question of whether the exocrine pancreas discharges digestive enzymes in a parallel or nonparallel fashion. A recent report (Rothman, S.S., and Wilking, H. (1978) J. Biol. Chem. 253, 3543-3549) claimed that the in vitro rabbit pancreas demonstrated nonparallel enzyme discharge after stimulation with cholecystokinin/pancreozymin, but that parallel discharge followed stimulation with the COOH-terminal octapeptide of cholecystokinin/pancreozymin. It was suggested that the full hormone acted to inhibit chymotrypsinogen secretion while stimulating trypsinogen secretion. Because of the fundamental importance of this question to our understanding of the exocrine secretion of exportable proteins, we have repeated these experiments using the same preparation and stimulant but have observed only parallel enzyme discharge. We conclude that it is unlikely that cholecystokinin/pancreozymin causes the selective inhibition of chymotrypsinogen secretion.

Amylases↗
PubMed1979

Harmonic-sensitive neurons in the auditory cortex of the mustache bat.

Human speech and animal sounds contain phonemes with prominent and meaningful harmonics. The biosonar signals of the mustache bat also contain up to four harmonics, and each consists of a long constant-frequency component followed by a short frequency-modulated component. Neurons have been found in a large cluster within auditory cortex of this bat whose responses are facilitated by combinations of two or more harmonically related tones. Moreover, the best frequencies for excitation of these neurons are closely associated with the constant-frequency components of the biosonar signals. The properties of these neurons make them well suited for identifying the signals produced by other echolocating mustache bats. They also show how meaningful components of sound are assembled by neural circuits in the central nervous system and suggest a method by which sounds with important harmonics (or formants) may be detected and recognized by the brain in other species, including humans.

Action Potentials↗
PubMed1979

Protease inhibitors and experimental acute hemorrhagic pancreatitis.

Proteolytic enzyme inhibitors have been reported to decrease morbidity and mortality from certain types of experimental pancreatitis, although recent randomized trials have been unable to demonstrate that they are of benefit in the treatment of clinical acute pancreatitis. We have evaluated the effect of two proteolytic enzyme inhibitors (trasylol and chlorophyll-a, on experimental acute pancreatitis induced in mice by the feeding of a choline-deficient ethionine-enriched diet. The mortality rate and the biochemical and morphological severity of pancreatitis were not altered by either trasylol or chlorophyll-a administration. Thus, in this respect, diet-induced pancreatitis appears to resemble clinical acute pancreatitis. The reasons for the lack of effectiveness of proteolytic enzyme inhibitors in the treatment of both forms of pancreatitis are discussed.

Acute Disease↗
PubMed1979

Non-traumatic uriniferous pseudocyst. Report of a case.

A non-traumatic uriniferous pseudocyst was incidentally found at autopsy in a patient with invasive urothelial carcinoma involving ureteral orifices. Massive paraaortic lymph node involvement by the metastic tumor in addition to the ureteral obstruction was considered responsible for the formation of uriniferous pseudocyst. The pertinent clinical history and autopsy findings are presented and a possible mechanism of pseudocyst formation is discussed.

Aged↗
PubMed1979

Two-dimensional electrophoresis of plasma proteins without denaturing agents.

A technique of two-dimensional polyacrylamide gel electrophoresis for the separation of plasma proteins is described. Human plasma proteins were separated by isoelectric focusing followed by electrophoresis in a 4 to 21% linear gradient gel slab. No denaturing agent was used throughout the procedure, so that the analysis of native proteins is possible. Two-dimensional patterns obtained from normal human plasma samples were recorded as "staining density maps," which are similar to contour line maps, and more than 230 protein spots were counted reproducibly on each "staining density map." This technique permits the simultaneous estimation of pI's and approximate molecular weights of native proteins on the slab gel. Applications of this technique to an IgA myeloma plasma sample and a porcine serum sample are described.

Animals↗
PubMed1978

Cortical neurons sensitive to combinations of information-bearing elements of biosonar signals in the mustache bat.

The auditory cortex of the mustache bat, Pteronotus parnellii rubiginosus, is composed of functional divisions which are differently organized to be suited for processing the elements of its biosonar signal according to their biological significance. Unlike the Doppler-shifted-CF (constant frequency) processing area, the area processing the frequency-modulated components does not show clear tonotopic and amplitopic representations, but consists of several clusters of neurons, each of which is sensitive to a particular combination (or combinations) of information-bearing elements of the biosonar signal and echoes. The response properties of neurons in the major clusters indicate that processing of information carried by the frequency-modulated components of echoes is facilitated by the first harmonic of the emitted biosonar signal. The properties of some of these neurons suggest that they are tuned to a target which has a particular cross-sectional area and which is located at a particular distance.

Action Potentials↗
PubMed1978

Aural representation in the Doppler-shifted-CF processing area of the auditory cortex of the mustache bat.

In the mustache bat (Pteronotus pamellii rubiginosus) the frequency and amplitude of an acoustic signal are represented in the coordinates parallel to the surface of the Doppler-shifted-CF (constant frequency) processing area ofthe primary auditory cortex. In this area all cortical neurons studied were excited by contralateral stimuli, and almost all of them were either excited or inhibited by ipsilateral stimuli. These are called E-E (ipsilateral and contralateral excitatory) and I-E (ipsilateral inhibitory and contralateral excitatory) neurons, respectively. The I-E neurons are directionally sensitive, while the E-E neurons are not. The E-E neurons are equally sensitive to echoes between 30 degrees contralateral and 30 degrees ipsilateral. Of the electrode penetrations orthogonal to the Doppler-shifted-CF processing area, 57 percent were characterized by either E-E or I-E neurons. Thus, there are at least two types of binaural columns: E-E columns, mainly located in a ventral part of the Doppler-shifted-CF processing area, where neurons are tuned to weak echoes; and IE columns, mainly distributed in a dorsal part, where neurons are tuned to moderate to intense echoes. Therefore, neurons tuned to weaker echoes integrate or even multiply faint signals from both ears for effective detection of a distant small target, while neurons tuned to moderate to intense echoes are suited for processing directional information and are stimulated when a bat approaches a target at short range. The Doppler-shifted-CF processing area may be considered to consist of two functional subdivisions.

Animals↗
PubMed1978

Primary carcinoma of the cystic duct.

We described a case of primary carcinoma of the cystic duct that conforms to previously established criteria. To our knowledge, this is the 21st recorded case; it was accidentally discovered during cholecystectomy. The features of all 21 cases are reviewed. Since these tumors tend to be treated surgically at an early stage because of the relatively early developement of clinical symptoms, such as right upper abdominal pain and palpable mass, caused by the obstruction of the cystic duct, the prognosis is better than that of other extrahepatic bile duct carcinomas.

Adenocarcinoma↗
PubMed1978

The freeze-fracture study of alveolar type II cells and alveolar content in fetal rabbit lung.

Freeze-fracture replication technique was utilized to study the morphology of type II alveolar epithelial cells and alveolar contents in the late gestation of rabbit fetuses. It was shown that the lamellar inclusion bodies of type II cells were enveloped by the usual type of unit membrane with membrane-associated particles of 15 nm diameter. The interior of the inclusion bodies was composed of multiple stacks and/or whorls of membranes which were devoid of membrane-associated particles. Small vesicles within the inclusion were found more frequently with this technique than in chemically fixed thin-sectioned preparations. The intra-alveolar contents were comprised of two components; sperical bodies, which were identical to the internal contents of the lamellar bodies of type II cells, and tubular elements. These tubules most often appeared rectangular on cross-fractured faces. Triangular hexagonal fracture faces were also noted. The tubules were seen to rest on the surfaces of the spherical components. Our observations suggest that the tubular element of alveolar contents is formed through the interaction between the discharged lamellar body content and the alveolar fluid, and further suggest that at least the major constituent of type II cell lamellar bodies is lipid not bound to protein. Three new observations were made in this study; the absence of membrane-associated particles on the interior of the lamellae of the inclusions, the cross-fractured profiles of tubular elements of the alveolar contents, and the occasional multicompartmental nature of type II cell inclusions.

Animals↗
PubMed1978

A freeze-fracture study of tubular myelin in fetal rabbit lung.

A freeze-fracture replication study was undertaken to clarify the relationship between intracellular lamellar bodies of type II alveolar epithelial cells and intra-alveolar contents in late gestation rabbit fetuses. The interior of the inclusion bodies was composed of multiple stacks and/or whorls of membranes devoid of membrane-associated particles, while the limiting membrane of intracellular lamellar inclusion bodies was studied with membrane-associated particles of 150A diameter. The intra-alveolar contents were comprised of two components; spherical bodies, and tubular elements. Spherical bodies were identical to the internal contents of the lamellar bodies and also were devoid of membrane-associated particles. Tubular elements mostly appeared rectangular on cross-fractured faces, but triangular and hexagonal forms could also be seen. These tubules rested on the surfaces of the spherical bodies and appeared to be formed of the outer lipid monolayer of spherical bodies. The present observations suggest that the tubular element of the alveolar contents is formed through the interaction between the discharged lamellar body content and the alveolar fluid.

Animals↗
PubMed1978

Impairment of cell-mediated immunity in ectodermal dysplasia with aplastic anemia.

A case of ectodermal dysplasia and aplastic anemia is presented in which a cell-mediated immunodeficiency led to a fatal Pneumocystis carinii infection. Elevated levels of IgG, IgA and IgD were present with normal specific antibody titres. A deficient cell-mediated immunity was documented by low T cell numbers, poor in vitro mitogenic responses, negative skin tests and by the histologic finding at autopsy of thymic dysplasia.

Anemia, Aplastic↗