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Biomedical subjects

C S Lin

Publications and source records attributed to C S Lin.

At least 271 records · Page 15Linked to original sources
PubMed1982

Lysosomotropic agents. 4. Carbobenzoxyglycylphenylalanyl, a new protease-sensitive masking group for introduction into cells.

Bioactive primary and secondary amines, when acylated with the Z-Gly-Phe group, are transported into pinocytic cells, such as macrophages, P-815 mastocytoma, SV-40 3T3, and leukemia 1210, much faster than the parent compounds. Amines such as lysosomotropic detergents [R. A. Firestone, J. M. Pisano, and R. J. Bonney, J. Med. Chem., 22, 1130 (1979) and nitrogen mustard, which are deactivated by acylation, are unmasked by enzymic action intracellularly, probably in lysosomes because an acidic pH maximum in activity exists which acts only on the L isomer. The added polarity and molecular weight brought about by acylation prevents the amines' normally facile entry into cells by simple diffusion, restricting it to an active-transport mechanism.

Animals↗
PubMed1981

Receptive field properties of neurons in the visual cortex of the rat.

The receptive field properties of neurons were examined in the visual cortex, area 17, of Long--Evans pigmented rats. Visually responsive cells comprised 90% of cells recorded in area 17. Five percent of these cells responded only to stationary stimuli, while the remaining responded to both stationary and moving stimuli or only to movement. Cells of the latter category were classified as complex (44%), simple (27%), hypercomplex (13%) or non-oriented (16%). The results presented here show that, contrary to existing reports, neurons in the rat visual cortex have well-defined receptive field properties.

Animals↗
PubMed1981

I-A mutation resulted in a selective loss of an antigen-specific Ir gene function.

The immune responses to several antigens were compared in the I-A mutant mouse strain B6.C-H-2bm12 and the wild-type strain C57BL/6. With a lymph node cell proliferation assay, the response to two of these antigens, beef insulin and (TG)A-L, was demonstrated to be controlled by a gene in the I-Ab region. B6.C-H-2bm12 mice failed to respond to beef insulin, while their responses to (TG)A-L, DNP-OVA and PPD were comparable with those of the wild-type strain C57BL/6. Taken together with previous studies, these data suggest that the product of a single pleiotropic I-A gene, an Ia molecule, functions as a histocompatibility, Ia, and MLR antigen, as well as a necessary component for Ir gene function. Furthermore, the data reported here demonstrate that Ia molecules have multiple functional "Ir determinants," one of which has been altered in the B6.C-H-2bm12 mutant. The B6.C-H-2bm12 mice, therefore, represent a powerful analytical tool for the understanding of the cellular and molecular basis for Ir gene control of the immune response.

Alleles↗
PubMed1981

Evaluation of free radical scavengers in studies of lymphocyte-mediated cytolysis.

Oxygen centered radicals derived from potassium superoxide (KO2) in solution were found to be toxic to P815 mastocytoma target cells. Protection of P815 cells from chemically generated radicals was mediated most efficiently by Tiron, a low molecular weight scavenger of superoxide radicals (O2-). Superoxide dismutase (SOD) and catalase also afforded protection. In vivo cytolysis of P815 target cells mediated by allogeneic lymphocytes sensitized in vivo to tumor cells was inhibited by reducing the amount of oxygen available for metabolism and by radical scavengers. Ferricytochrome c, Tiron, and phenol, all of which are relatively low molecular weight radical scavengers, inhibited cytolysis in a dose-dependent manner, while mannitol, a hydroxyl radical scavenger, did not. High molecular weight scavengers like SOD and catalase had no effect. The inhibition of cytolysis by radical scavengers was found to be independent of toxic effects on effector cells, chelation of ions, or indirect effects on prostaglandin biosynthesis. Pretreatment of either effector or target cells with Tiron had no effect on LMC. The data suggest a possible role for free radicals in molecular events leading to target cell injury by sensitized lymphocytes.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗
PubMed1981

Mossy fiber and Purkinje cell axon collateral arborization patterns in normal and X-irradiated rat cerebellum: a light microscopic study using horseradish peroxidase fiber filling techniques.

The horseradish peroxidase neuronal staining technique was applied to reveal through anterograde and retrograde staining the detailed morphology of fiber arborization patterns in the cerebella of normal adult rats as well as those treated with neonatal X-irradiation. Morphological features of anterogradely-filled mossy fibers including the axonal arborization and glomerular-type synaptic specializations were found to be similar in all groups studied. In addition, retrogradely-filled Purkinje cell axon collaterals in the cerebella degranulated by X-irradiation exhibited much more elaborate branching and arborization of recurrent collaterals than those labeled in the normal cerebellar cortex. The presence of glomerular-type specializations in the degranulated cerebellum suggested that mossy fibers develop and maintain their normal features independent of major influences from granule cells. The hypertrophy observed after destruction of the cerebellar interneurons suggests the hypothesis that the growth of the normal Purkinje cell collateral system is normally suppressed by extrinsic factors within the neuronal circuit.

Animals↗
PubMed1981

Prostaglandins and renin release in vitro.

The present studies were undertaken to explore further the role of prostaglandins in the release of renin from the renal cortex. To provide the best assessment of renin release, renin was determined by a radioimmunoassay for the direct measurement of renin. Slices of mouse renal cortex were incubated at 37 degrees C with arachidonic acid (AA), 5,8,11,14-eicosatetraenoic acid (ETA), indomethacin, prostaglandins, and synthetic prostaglandin endoperoxide analogue (EPA). Our results showed that AA at 1.5 X 10(-8) M significantly increased renin release at 10 and 30 min of incubation. This renin increase ws abolished by either ETA or indomethacin. Prostaglandin F2 alpha (PGF2 alpha) also significantly stimulated renin release at 10 and 60 min. PGE2 and 16,16-dimethyl PGE2 (DMPGE2) showed much less renin release-stimulating activity. EPA and PGI2 on the other hand very strongly stimulated renin release. However, at higher concentrations the stimulating effect of PGI2 and EPA disappeared and even became inhibitory in the case of EPA. Other prostaglandins were found to have no effect on renin release. The results suggest that the prostaglandin system directly affects renin release from the juxtaglomerular cells independent of systemic neurogenic and hemodynamic influences.

Animals↗
PubMed1981

Cytomegalic inclusion disease of the skin.

Acute cytomegalovirus infection was associated with two episodes of morbilliform eruption in a patient receiving ampicillin therapy. Shortly after the eruption cleared, the patient died. Histologic examination of the skin indicated a cytomegalovirus infection of the vascular endothelium with luminal obliteration, stasis, vasculitis, and thrombus formation.

Aged↗
PubMed1980

Interaction of D 600 with phenoxybenzamine-induced adrenergic blockade.

Pretreatment of the vas deferens with D 600 (1 x 10(-5) M/10 min) prior to addition of phenoxybenzamine (PB) (1 x 10(-7) M/5 min) had no effect on the magnitude of initial adrenergic blockade but significantly increased the rate of recovery from blockade. These results suggest that the long duration of action of PB may be due to its action at calcium mobilization sites.

Animals↗
PubMed1980

Short rib-polydactyly syndrome, type 3 with chondrocytic inclusions: report of a case and review of the literature.

A newborn with severely shortened ribs, short limbs, and postaxial polydactyly died shortly after birth. Postmortem roentgenograms established the diagnosis of type 3 short rib-polydactyly (SRP) syndrome as described by Naumoff and associates. Histopathologic study showed the chondrocytes to contain previously undescribed cytoplasmic inclusion bodies that were PAS-positive and diastase-resistant. The material appeared by staining reactions to be a glycoprotein that was seen electron microscopically to accumulate within dilated cisterns of rough endoplasmic reticulum. Similar cytoplasmic inclusions have not been seen in other short rib-polydactyly syndromes, including SRP types 1 and 2, Jeune syndrome, and Ellis-van Creveld syndrome. It is often difficult to differentiate cases of type 3 and type 1 (Saldino-Noonan) syndrome, and in the past the diagnosis has sometimes been confused. A review of previously reported cases showed that type 3 syndrome rarely (1 in 13) had cloacal developmental abnormalities, which are invariably present in patients with type 1 syndrome. Type 3 is also associated with a lower incidence of congenital heart disease, and cardiac malformations, when present, differ from those associated with type 1 syndrome. Both type 3 and type type 1 SRP syndromes are transmitted in autosomal recessive fashion. Type 3 SRP syndrome has had an equal sex distribution, although type 1 has so far been reported to occur only in girls. Further investigation with additional patients is necessary to verify the above preliminary findings.

Bone Diseases, Developmental↗
PubMed1980

Effects of monocular deprivation on geniculocortical pathways in the owl monkey, Aotus trivirgatus.

As has been shown for a number of other mammals, monocular eyelid suture in the newborn owl monkey, a New World primate, is followed by a failure of neurons in the deprived layers of the lateral geniculate nucleus to reach normal size in the adult animal. This failure appears to be almost completely confined to relay cells, identified by horseradish peroxidase (HRP) injections into cortex, rather than interneurons. Similar proportions of neurons in both the deprived and non-deprived layers are labeled after HRP injections, suggesting that relay cells do not lose all cortical connections as a result of visual deprivation.

Animals↗