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Biomedical subjects

C L Shen

Publications and source records attributed to C L Shen.

72 records · Page 4Linked to original sources
PubMed1987

An autoradiographic study of the retinal projections in the Formosan monkey.

This study investigated the retinal projections of the adult Formosan rock monkey by monocular injection of radioactive proline and fucose. We found that the retinofugal fibers terminated bilaterally in the suprachiasmatic, pregeniculate, lateral geniculate, pretectal complex, pulvinar nucleus, superior colliculus, dorsal and lateral terminal nuclei of the accessory optic system. More crossed retinal terminations were observed, with the exception that the suprachiasmatic nucleus received almost equally of both retinal projections. The existence of the retinal projection to the medial terminal nucleus of the accessory nucleus was in doubt. In the geniculate nucleus, the retinal fibers terminated contralaterally in layers 1, 4 and 6; and ipsilaterally in 2, 3 and 5. In the superior colliculus, most retinal fibers were aggregated superficially in a band located in the contralateral striatum griseum superficialis of the superior colliculus, and had few gaps on the ipsilateral one. The present investigation shows that the Formosan rock monkey has a similar pattern of optic fiber distribution to that of other macaques.

Animals↗
PubMed1987

Retinofugal sprouting of ipsilateral projections in rat.

Expansion of ipsilateral retinal inputs into terminal regions of the primary was assessed in rats enucleated at birth or as adults. In addition, one animal with a congenital absence of one eye received an injection of the label into the remaining eye and was similarly processed. Analysis of the sections revealed an increase in retinal inputs, relative to control injections, in the lateral geniculate nucleus and the superior colliculus. The increase observed in the brains of animals receiving enucleation at birth was greater than the increase observed after eye removal in the adult, although the greatest increase was observed in the animal with the congenital loss of one eye. Differences in the sprouting response within the various terminal areas as well as the age related decrease in the ability of retinofugal axons to sprout into denervated visual areas in the brain are discussed.

Aging↗
PubMed1986

Tyramine-induced release of neuropeptide Y (NPY) in isolated rabbit intestine.

The effect of tyramine on the contractile activity of rabbit ileal segments was studied. Treatment with tyramine initiated a short-lived, fast contraction followed first by a relaxation then by a subsequent sustained contracture. Although the mechanism of the initial fast contraction remains obscure, the relaxation was abolished by the pretreatment with a combination of phentolamine and propranolol and the sustained contracture was blocked by neuropeptide Y (NPY)-antiserum. The inhibitory effect of the NPY-antiserum was produced in a dose-dependent manner. Thus, it is suggested that tyramine induced the release of NPY to initiate the subsequent sustained contracture.

Animals↗
PubMed1986

Expansion of the ipsilateral retinal projection to the medial terminal nucleus of the accessory optic system in rats with one eye removed.

Expansion of ipsilateral retinal inputs into terminal regions of the accessory optic system was assessed in rats with one eye removed either at birth or as adults and in one animal with a congenital absence of one eye. The increase in the ipsilateral projection to the medial terminal nucleus in animals receiving unilateral enucleation at birth was greater than after eye removal as an adult. The greatest increase was observed in the animal with the congenital loss of one eye. No ipsilateral projection to other nuclei of the accessory optic system was observed.

Animals↗
PubMed1985

Ultrastructural sequence of myelin breakdown during Wallerian degeneration in the rat optic nerve.

Adult albino rats were subjected to unilateral surgical removal of the eyeball. After survival times of 7-140 days, the numerical response of the neuroglial cells, and the progressive disintegration of the myelin sheaths in the optic nerves, were studied qualitatively and quantitatively in electron-microscopic montages. The distribution density of microglia and astroglia in degenerating optic nerve increased to peaks after 35 and 56 days respectively, whereas, the oligodendroglia gradually decreased. During the early stage of degeneration, microglial cells appeared and invaded the sheath at the intraperiod line, peeling off the outer lamellae, which were then engulfed by phagocytosis. Within the microglia, myelin sheath fragments were surrounded by a membrane curled to form a myelin ring. In the intermediate stage of degeneration, the paired electron-dense lines of the ring, made up of myelin basic protein, decomposed and formed a homogeneous or heterogeneous osmiophilic layered structure, the myelin body, which, in the final stages, disintegrated and transformed into globoid lipid droplets and needle shaped cholesterol crystals.

Animals↗
PubMed1984

Neuroglia of the adult rat optic nerve in the course of wallerian degeneration.

The neurological reactions in Wallerian degeneration have been studied by electron microscopy in the optic nerve of adult albino rats from 7 to 120 days after unilateral enucleation. Reactive astrocytes contained abundant dense bodies, numerous microtubules and hyperplastic glial filaments. These astrocytes also assisted phagocytosis of degenerated myelin sheaths and in glial scar formation. Oligodendrocytes disconnected their cytoplasmic extensions, which were phagocytosed by microglial cells and astrocytes, by increased production of lysosomes. Microglial cells consisted of crinkled, long, rough endoplasmic reticula, several highly-active Golgi complexes, laminar inclusions and globoid lipid droplets. Microglia engulfed and lysed the disintegrated axons and myelin sheaths.

Animals↗
PubMed1983

Efferent projections from the mammillary complex of the guinea pig: an autoradiographic study.

The efferent projections from the medial and lateral mammillary nuclei of the guinea pig were traced after injecting tritiated amino acid. The major efferent started as the principal mammillary tract, but soon divided into mammillothalamic and mammillotegmental tracts. The mammillothalamic tract projected anterodorsally and terminated in the anterior dorsal, anterior ventral and anterior medial thalamic nuclei. The mammillotegmental tract projected caudally and terminated in the dorsal tegmental nucleus and central gray. The mammillary efferents in the mammillary peduncle ran via the tegmentum of the midbrain and pons. It terminated in the dorsal and ventral tegmental nuclei, basal pontine nucleus and pontine tegmental reticular nucleus. A diffuse mammillary projection had fibers directed dorsally which distributed in the midline thalamic nuclei and in central gray. Rostral projections via the medial forebrain bundle from the medial mammillary nucleus were found in the septal area and diagonal band of Broca. The lateral mammillary nucleus sent fibers which also joined the mammillothalamic and mammillotegmental tracts. These terminated bilaterally mainly in the anterior dorsal and anterior ventral nuclei of the thalamus, and caudally in the dorsal and ventral tegmental nuclei and basal pontine nucleus.

Animals↗
PubMed1983

Efferent projections from the lateral hypothalamus in the guinea pig: an autoradiographic study.

Autoradiography was employed to investigate the efferent projections from the lateral hypothalamus in the guinea pig. Lateral hypothalamic axons were traced along the medial forebrain bundle in both ascending and descending directions. Anteriorly, the label was traced along the medial forebrain bundle in both ascending and descending directions. Anteriorly, the label was traced to the lateral preoptic area, diagonal band of Broca, and septal nuclei. Posterior projections included the ventral tegmental area of Tsai, central gray matter and the reticular formation throughout the brain stem. Laterally, the lateral hypothalamic efferents were found in the stria terminalis, amygdala and globus pallidus. Dorsally, the lateral hypothalamic axons projected to the midline nuclei of the thalamus and bilaterally to the lateral habenular nuclei. Projections to the medial hypothalamus included a labeled fiber bundle to the internal layer of the median eminence and to the posterior lobe of the pituitary gland. Labeled fibers and diffuse label were also found in some areas contralateral to the injection site.

Amygdala↗
PubMedDate not supplied

Distribution of FMRFamide-like immunoreactivity in the central nervous system of the Formosan monkey (Macaca cyclopsis).

The distribution of FMRFamide-like immunoreactivity in the central nervous system of the Formosan monkey (Macaca cyclopsis) was investigated employing immunohistochemical techniques. FMRFamide-containing cells were found to be widely distributed throughout the forebrain. Principal densities of FMRFamide neuronal perikarya were observed in the following areas: the amygdaloid complex, the olfactory tubercle, the cerebral cortex, the basal ganglia, the septum, the caudate-putamen and the arcuate nucleus. A large number of immunoreactive fibers were observed in areas ranging from the cerebral cortex to the spinal cord, and were noted in the following locations: the preoptic area, the tuberal and posterior hypothalamic areas, the bed nucleus of the stria terminalis, the nuclei of the spinal trigeminal nerve, the hypoglossal nucleus, the nucleus of the solitary tract, and the dorsal horn of the spinal cord. The results generally parallel those described in the rat and guinea pig.

Animals↗
PubMedDate not supplied

Efferents of the medial preoptic area in the guinea pig: an autoradiographic study.

Medial preoptic axons were traced into the diagonal band of Broca and septum, particularly lateral septum. Other labeled fibers could be followed dorsally from medial preoptic area injections adjacent to the stria medullaris, and in the periventricular fiber system and the stria terminalis and its bed nucleus. The anterior and medial amygdaloid nuclei were labeled by fibers via the stria terminalis and other arching over the optic tract and through the substantia innominata. The lateral habenula was labeled. Labeled periventricular fibers reached the periventricular nucleus of the thalamus. Descending efferents were traced principally below the fornix and in the adjacent lateral hypothalamus to label the anterior hypothalamus, the tuberal nuclei, and median eminence. Axons of the medial preoptic area joined the medial part of the medial forebrain bundle and distributed to the reticular formation and the central gray of the midbrain and pons. A small amount of contralateral connections were described.

Animals↗
PubMedDate not supplied

Efferents from the medial anterior hypothalamic area in the guinea pig.

Medial anterior hypothalamic connections were studied with H3-proline and autoradiography. Most of the axons projected to other hypothalamic nuclei. The major pathways were found ventral medial to the fornix and in the periventricular tract. Substantial projections were apparent in the ventromedial and dorsomedial nuclei with less label in the arcuate nucleus. The dorsal premammillary nuclei were labeled bilaterally, particularly with more caudal injections of anterior hypothalamus. Efferents were evident in the posterior hypothalamus and continued into the central gray of the midbrain. Labeled fibers reached the ventral tegmental area and in the reticular formation were traced only through pons. Rostral projections were to the medial and lateral preoptic areas and ventral lateral septum. The bed nucleus of stria terminals was labeled a very few fibers reached the medial amygdaloid nucleus. The periventricular nucleus of thalamus was labeled.

Animals↗
PubMedDate not supplied

Liver volume in patients with or without chronic liver diseases.

BACKGROUND/AIMS: The size of the liver is an important clinical parameter; the aim of this study is to examine the correlation between liver volume and etiology and the severity of disease, and to evaluate its usefulness in predicting survival. METHODOLOGY: Patients observed in this study were comprised of thirty three patients with non-liver disease and 44 patients with chronic liver disease (alcoholic hepatitis, 9; hepatitis B, 24; and hepatitis C, 11). The liver volume was measured from digitized CT scan images. Techniques of planimetry and summation of areas were utilized for calculation. RESULTS: The prediction model to estimate liver volume in patients without liver disease was: liver volume (ml)= [13 x height (cm)] +[12 x weight (Kg)] - 1530. The volume ratio (%) [(volume from reconstructed image /predicted volume) x 100] of alcoholic patients was 135.9+/-25.8, which was significantly higher than that of chronic hepatitis B (73.6+/-15.4) and chronic hepatitis C (74.5+/-20.7). Patients with chronic viral hepatitis were classified into Child-Pugh class A (N=10), B (N=14) and C (N=11). Analysis of variance and trend test revealed that the volume ratio had a significant decreasing trend from the control group (100.5+/-8.1), class A (83.4+/-13.9), class B (72.2+/-13.2) to class C (63.3+/-14.4). CONCLUSIONS: Liver volume can be predicted from patients' weight and height if they have no liver disease. The liver volume ratio correlates much better with etiology and severity of the disease and is a reliable predictor for patient's survival.

Adult↗