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Biomedical subjects

Y Sano

Publications and source records attributed to Y Sano.

At least 343 records · Page 19Linked to original sources

[Focal nodular hyperplasia-like lesion of the liver associated with thorotrast liver disease--report of a case].

A 66-year-old man with Thorotrast liver disease underwent a partial hepatectomy for a small tumor of the liver, which was demonstrated by digital subtraction angiography. The resected specimen was grossly a sharply circumscribed, gray-yellow nodule, 7.5 mm in diameter. Microscopically, the nodule was an ill-defined hepatic cell mass, which was divided by fine fibrous septa irregularly and incompletely. Central veins and Glisson's capsules were not observed inside the nodule. Bile duct proliferation and infiltration of lymphocytes were found in the fibrous septa. There were Thorotrast depositions within the fibrous tissues around the nodule. Because a typical fibrous boundary and central scar were not found, we have termed this condition a focal nodular hyperplasia-like lesion. A relationship between focal nodular, hyperplasia as a precancerous state and Thorotrast liver disease was suggested.

Aged↗

Immunohistochemical demonstration of serotonin-containing nerve fibers in the hypothalamus of the monkey, Macaca fuscata.

The distributional pattern of serotonin-containing nerve fibers in the hypothalamus of the monkey (Macaca fuscata) was analyzed with the use of the peroxidase-antiperoxidase method in conjunction with a highly sensitive and specific anti-serotonin serum. The highest concentrations of serotonin-immunoreactive varicose fibers were found in the nucleus praeopticus medialis, nucleus ventromedialis hypothalami, and the complex of mammillary nuclei (nucleus praemamillaris, supramamillaris, mamillaris medialis et lateralis). However, the nucleus suprachiasmaticus, where numerous serotoninergic fibers have been reported to occur in the rat, appeared to be almost devoid of these fibers. The infundibular stalk and the intermediate and posterior lobes of the pituitary contained considerable numbers of immunoreactive fibers. The present study provides a morphological basis for possible clarification of the influence of serotoninergic projections on various neuroendocrine mechanisms in primates. Furthermore, an attempt was made to clarify the differences and similarities concerning the distributional patterns of serotoninergic nerve fibers within the monkey hypothalamus in contrast to the rat hypothalamus.

Animals↗

Immunohistochemical study on the morphology of enterochromaffin cells in the human fundic mucosa.

The morphology of enterochromaffin (EC) cells in the human fundic mucosa was investigated at the light-microscopic level by means of the unlabeled peroxidase anti-peroxidase method, with the use of a highly specific anti-serotonin serum. EC-cells in the human fundic mucosa were sparsely distributed below the neck portion of the gland, but were found to be rather numerous in its lower half. Immunohistochemistry revealed marked pleomorphic and seemingly polynuclear EC-cells or cells with long, sometimes multipolar cytoplasmic processes. In addition, luminal contacts and contiguity between EC-cells, or interglandular connections were also encountered. The present immunohistochemical procedure permits, for the first time, a clear-cut morphological visualization of the entire population of EC-cells, and reveals the distinctive morphological features of these cells in the human fundic mucosa. These morphological findings imply that EC-cells in the fundic mucosa may be crucial in gastric function.

Chromaffin System↗

Serotonin nerve fibers in the primary visual cortex of the monkey. Quantitative and immunoelectronmicroscopical analysis.

A quantitative and immunoelectronmicroscopical analysis of serotonin nerve fibers in the primary visual cortex of the monkey (Macaca fuscata) was made using a sensitive immunoperoxidase method for serotonin. The overall numerical density of serotonin-containing varicosities in the primate striate cortex was approximately 770,000/mm3 and the highest concentration of immunoreactive varicosities (ca. 1,400,000/mm3) was observed in the upper portion of layer IVc, the next highest concentration being in layer IVb (ca. 1,180,000/mm3). At the ultrastructural level, the electron dense immunoreactive products were observed in the small granules (10-65 nm in diameter). The varicosities were usually small (0.5-1.0 micron in diameter) and made contact with both stellate and pyramidal cells. Serotonin fibers were often in close apposition to the poorly myelinated axons in layers IVb, V, and VI, and they rarely formed distinct synaptic structures with unlabelled neuronal elements.

Animals↗

Immunohistochemical demonstration of the serotonin neuron system in the central nervous system of the bullfrog, Rana catesbeiana.

The distribution of serotonin immunoreactivity in the brain of the bullfrog (Rana catesbeiana) was studied, using the peroxidase-antiperoxidase (PAP) immunohistochemical method with serotonin antiserum. The somata of the serotonin neurons were mainly located in the raphe regions of the brain stem from the level of the caudal mesencephalon to that of the spinomedullary junction. A small number of serotonin neurons were also distributed as cerebrospinal-fluid contacting neurons in the preoptic recess organ (PRO), the paraventricular organ (PVO), and the nucleus infundibularis dorsalis (Nid). In the raphe region, these serotonin neurons formed nearly-continuous bilaterally-symmetrical cell columns along the midline of the brain stem, divided into lateral and medial groups. The medial group was further subdivided into rostral and caudal parts. Processes of the serotonin neurons were widely distributed in the central nervous system, forming dense networks in various regions. The greatest concentrations of these fibers were in the nucleus medialis septi, lateral portion of striatum, nucleus corporis geniculi, nucleus entopeduncularis, periventricular gray of ventral hypothalamus, optic tectum, nucleus isthmi, nucleus interpeduncularis, dorsal edge of medulla oblongata, and fasciculus solitarius.

Animals↗

Sexual differences in the topographical distribution of serotonergic fibers in the anterior column of rat lumbar spinal cord.

Sexual dimorphism in the topographical organization of immunoreactive serotonergic fibers has been shown for the first time in the anterior column of the rat lumbar cord. A characteristic preferential arrangement of serotonergic fibers on the small cell column composed of anterior horn motoneurons, which have been proved to send their axons to the cremaster muscle, was demonstrated at the lumbar segments (L1-L2) of male rats, using the immunoperoxidase technique with antiserum against serotonin. A similar finding was also observed in female rats, but was less prominent than in males. Comparative analysis of the cell numbers and the size of neuronal somata of the aforementioned nucleus, done using retrograde transport of fluorescent dye (DAPI) via axonal fibers coursing down the genitofemoral nerve to the cremaster muscle, gave significantly larger values in males. The sexual difference in the serotonergic innervation pattern was, in consequence, surmised to be caused by the cytoarchitectonic contrast ascertained in the lumbar anterior column. Furthermore, there may be a striated muscle endowed with some active functions homologous to those of the male cremaster muscle in the female rat.

Animals↗

Serotonin immunohistochemistry reveals immature EC cells.

Radioautographic studies of rat duodenal mucosa were carried out after single injections of 3H-thymidine, and the labelling indices of enterochromaffin (EC) cells identified by serotonin immunohistochemistry and by the diazo reaction were compared. The labelling index of EC cells by serotonin immunohistochemistry was 2.3% (mean percentage of 2 rats), while no labelled cells were found in diazo-positive EC cells. This finding indicates that serotonin immunohistochemistry reveals a less mature population of EC cells than conventional techniques such as the diazo reaction.

Animals↗

Fluorescence histochemical study on the noradrenergic control to the anterior column of the spinal lumbosacral segments of the rat and dog, with special reference to motoneurons innervating the perineal striated muscles (Onuf's nucleus).

The organization of noradrenergic fibers in the lumbosacral anterior column of rats and dogs was examined in detail using a modification of a highly sensitive glyoxylic acid fluorescence histochemical method. In both rat and dog, there were greater concentrations of fluorescing noradrenergic fibers around the motoneurons innervating the perineal striated muscles (Onuf's nucleus) than around other motoneuronal groups. The preferential accumulation of noradrenergic fibers in Onuf's nucleus may indicate that the noradrenergic neuron system in the spinal cord of rodents and carnivores is closely related to the functional peculiarities of the perineal striated muscles, including the external anal and urethral sphincter muscles.

Animals↗

Ontogenesis of the central serotonin neuron system of the rat--an immunohistochemical study.

The peroxidase-antiperoxidase technique was used to study the ontogenesis of serotonin-containing neurons in fetal, neonatal and adult rats. Serotonin-containing neurons were first detected in a rat embryo of crown-rump length (CRL) 5 mm, bilaterally distributed in the ventral metencephalon near the isthmus rhombencephali. Serotonin fibers were first detected in CRL 6 mm embryos. There was a rapid increase in serotonin-immunoreactive neurons of embryos of 7-8 mm CRL. Serotonin neurons appeared initially as independent, bilateral groups of neurons, but as early as CRL 16 mm, the adult mid-line distribution was present, while the neurons that occurred as single groups in the adult already existed as single groups or at least were only partially connected across the mid-line. A continuous distribution of serotonin neurons was observed in the mesencephalic and pontine reticular formation from CRL 13 mm to the adult stage. It is suggested that the rapid increase in serotonin neurons at 7 and 8 mm CRL is associated with the completion of mitosis which occurs at this time.

Animals↗

Genetic determinant of pyocin AP41 as an insert in the Pseudomonas aeruginosa chromosome.

The genetic determinant for pyocin AP41 , a bacteriocin produced by Pseudomonas aeruginosa PAF, was transferred to P. aeruginosa PAO and analyzed. By conjugation experiments, the pyocin determinant was found to be located on the chromosome, being closely linked to argG at about 45 min on the genetic map. Cloning of the pyocin AP41 gene into the plasmid R68.45 was attempted in vivo by taking advantage of its linkage at argG. R' argG+ plasmids were isolated by interspecific conjugation between P. aeruginosa and Escherichia coli recA argG strains. Some of the R' argG+ plasmids did contain the pyocin AP41 determinant. Genetic and physical analyses of these R' plasmids indicated that the pyocin AP41 determinant was located within a 2.9-kilobase extra segment found at a certain position of the chromosome of various pyocin AP41 producer strains.

Bacteriocins↗

Serotonin-containing neurons in the rat and cat brain, especially in the hypothalamus, following monoamine oxidase inhibitor pretreatment: an immunohistochemical study using anti-serotonin antiserum.

The presence of serotonin-containing neurons in the hypothalamus of the rat and cat was studied by immunohistochemistry. In the rat, a group of serotonin-immunoreactive neurons was observed in the nucleus dorsomedialis hypothalami following nialamide pretreatment at a high dosage (over 300 mg/kg). In the cat, serotonin-immunoreactive neurons were sparsely distributed in the ventral part of the middle to the caudal lateral hypothalamic area after high dosage (500 mg/kg) nialamide pretreatment.

Animals↗

[Successful resection of giant hepatocellular carcinoma with hypoglycemic attack].

We experienced a 68 years-old male who had frequent hypoglycemic attacks. The diagnosis of a giant hepatoma associated with hypoglycemia was established by oral glucose tolerance test (O-GTT), angiography and computed tomography. The cavography demonstrated the invasion or depression of the tumor. It was ascertained by an operative exploration that the tumor occupied most of the right trisegments of the liver and infiltrated into a part of the left lateral segment. The right hepatic trisegmentectomy along 1.5cm left side line apart from the falciform ligament was performed. Resected tumor showed 11 X 13 X 10cm in size and 1200g in weight. Microscopic findings demonstrated hepatocellular carcinoma as Edmondson's Type II. After the operation, this patient became free from the hypoglycemic attack. A fasting blood sugar became within normal limits and O-GTT demonstrated a normal blood sugar level and insulin response. No concentration of immuno-reactive insulin was found in the resected tumor, however, the blood sugar in rats which received the intravenous injection of the tumor extracts was remarkably decreased in 20 minutes. From these observation, hypoglycemia in this patient seemed to depend mainly on the factor of insulin-like activity of the tumor. In the literature, the hepatocellular carcinoma associated with paraneoplastic phenomenon, e.g. hypoglycemia, has rarely been resected because of accompanied liver cirrhosis or giant size of the tumor. This is the second patient in our country in whom the tumor was fortunately resected and the paraneoplastic syndrome disappeared postoperatively.

Aged↗

Establishment of three PPD-reactive helper T cell clones with distinct functions in B cell activation.

Three PPD-reactive long-term cultured helper T cell clones were established from Mycobacterium tuberculosis (Tbc)-primed spleen cells. Clones B11.15 and B12.F were derived from C57BL/6 mice, and clone D-2 was originated from DBA/2Ha mice that have an X-linked recessive inheritance of T cell-replacing factor (TRF) unresponsiveness. Proliferative responses of these cloned T cells were induced by stimulation with PPD in a dose-dependent manner only when I-A-subregion compatible antigen-presenting cells (APC) were present. These three T cell clones have distinct helper functions in B cell activation. Clone B11.15 activated DNP-primed B cells to induce anti-DNP IgM plaque-forming cell (PFC) responses only when high amounts of PPD (5 micrograms) were added to the culture in a major histocompatibility complex (MHC)-unrestricted manner (factor-mediated interaction), whereas stimulation with a low amount of DNP-PPD (0.05 microgram) was ineffective. On the other hand, clone D-2 triggered B cells in the presence of a low amount of DNP-PPD in a MHC-restricted manner (cognate interaction). Significant helper activity of D-2, however, was not observed in the presence of high amounts of PPD. Clone B12.F was able to activate B cells in the presence of either DNP-PPD or PPD. Moreover, both B11.15 and B12.F produced helper factor(s) such as TRF by stimulation with high amounts of PPD in the presence of syngeneic APC, whereas D-2 did not produce measurable helper factor(s) under the same conditions. These results suggest that at least three distinctly functioning PPD-reactive helper T cells can be generated by active immunization with Tbc in vivo. T-B cell interaction between distinctly functioning T cell clones and B cells from (DBA/Ha X C57BL/6) (DB6)F1 male or female mice was then examined. B cells from DB6F1 female mice were triggered by both B11.15 and B12.F in a factor-mediated manner and were also activated with B12.F or D-2 in cognate manner. On the other hand, B cells from DB6F1 male mice, which are TRF low responders, were activated by B12.F or D-2 only through cognate interaction, and they failed to cooperate with B12.F or B11.15 in factor-mediated manner. These findings further suggest that B cells can be triggered by at least two distinct helper T cell subpopulations via respective pathways (cognate interaction and factor-mediated interaction).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗