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Biomedical subjects

G X Song

Publications and source records attributed to G X Song.

At least 37 records · Page 2Linked to original sources
PubMed1986

Immunoultrastructural demonstration of prostatic acid phosphatase isoenzyme 2 in prostatic carcinoma.

Human prostatic acid phosphatase isoenzyme 2 (HPAcP-2) was isolated from semen. This purified enzyme was immunized to rabbit to produce polyclonal antibodies. The specificity of the antibodies was tested by Western blot transfer method. Rabbit IgG-peroxidase conjugate was prepared from the antiserum and used to localize HPAcP-2 in prostatic carcinoma. It was found that in the tumor glandular acinus the normal basal cells were replaced by tumor cells containing reaction product. In the tumor cells, the reaction product was seen in the cisternae of rough endoplasmic reticulum (ER) and Golgi apparatus. The secretory vesicles which contained reaction product-stained granules and some amorphous material were seen to fuse with the apical plasma membrane and discharged their content into the glandular lumen. On the other hand, some secretory vesicles in the tumor cells facing to the basement membrane also discharged their similar content into the extracellular spaces. Reaction product-stained granules were found in the interstitial spaces surrounding the tumor cells. These findings suggest that HPAcP-2 is synthesized on the bound ribosomes and discharged into the cisternae of rough ER. The molecules are transported to the Golgi cisternae. After concentration and packaging, HPAcP-2 molecules are then transferred to the secretory vesicles, and discharged into the glandular lumen and to the extracellular spaces. The isoenzyme released in the extracellular space may reach the blood stream through the interstitial spaces or the lymphatic system, resulting in the elevation of serum HPAcPase level in some prostatic cancer patients.

Acid Phosphatase↗
PubMed1986

Calmodulin: localization in plant tissues.

Calmodulin was purified from bovine brain by preparative SDS-polyacrylamide gel electrophoresis. The denatured, purified calmodulin was used to immunize rabbits to produce antiserum. This antiserum was used to study the distribution of calmodulin in plant tissues by indirect immunohistochemistry. The root tips from corn seeds, oat seeds, peanuts, spaghetti squash seeds, and the terminal buds of spinach were investigated. A method for plant tissue sectioning and inhibition of endogenous peroxide activity was developed. In the corn root section, reaction product from anti-calmodulin was found mainly in the root cap cells. Lesser but significant amounts of calmodulin were localized in metaxylem elements, in some stele cells surrounding metaxylem elements, in apical initials, and in the cortical cells. Similar findings were also observed in other root tips from oat seeds, peanuts, and spaghetti squash seeds. In the terminal buds of the spinach, calmodulin-stained cells were highly concentrated in the apical meristem and leaf primordium. These findings suggest that the high concentration of calmodulin in the root cap may be important in relation to gravitropism and growth development.

Calmodulin↗
PubMed1985

Is taurine a neurotransmitter in rabbit retina?

Rabbit retina was used as a model to study the possible role of taurine in the retina. The taurine-synthesizing enzyme, cysteine sulfinic acid decarboxylase (CSAD), is localized immunohistochemically using specific antibodies against CSAD. The CSAD-immunoreactivity appears to be most prominent in the inner nuclear layer (INL) and ganglion cell layer (GCL). The inner plexiform layer (IPL), the outer nuclear layer and outer plexiform layer are sporadically stained. The CSAD-positive neurons include some amacrine cells and probably the bipolar cells in the INL and some large and small ganglion cells in the GCL. Autoradiographic studies reveal that the uptake of [3H]taurine is most prominent in the INL. The IPL and GCL, as well as the Müller cells, also show a moderate degree of [3H]taurine accumulation. In conclusion, we have demonstrated the presence of the taurine-synthesizing enzyme and uptake systems in rabbit retina. Based on the above evidence, we propose that taurine may be used by some neurons, presumably amacrine cells, as a transmitter in the rabbit retina.

Animals↗
PubMed1985

Ultrastructural demonstration of L-glutamate decarboxylase and cysteinesulfinic acid decarboxylase in rat retina by immunocytochemistry.

The gamma-aminobutyric acid (GABA) synthesizing enzyme, L-glutamate decarboxylase (GAD), and the taurine synthesizing enzyme, cysteinesulfinic acid decarboxylase (CSAD) have been localized in rat retina at the ultrastructural level by indirect immunoelectron microscopy. GAD immunoreactivity (GAD-IR) was seen only in some amacrine cells and their terminals. CSAD immunoreactivity (CSAD-IR) was found in most retinal neuronal types and their processes including photoreceptor cells (rod and cone cells), bipolar cells, amacrine cells and ganglion cells. The GAD-IR positive amacrine terminals have been found to make synaptic contact with other GAD-IR negative bipolar and amacrine terminals, and ganglion cell dendrites. Most of the GAD-IR positive terminals are presynaptic. Occasionally, GAD-IR positive amacrine terminals are postsynaptic to another amacrine terminal or ganglion cell body. In the inner plexiform layer, CSAD-IR positive amacrine terminals also make synaptic contacts with other nerve terminals, similar to that of GAD-IR positive amacrine terminals. In addition, CSAD-IR positive bipolar terminals make synaptic contact with some CSAD-IR positive as well as negative amacrine terminals. Both CSAD-IR positive amacrine and bipolar terminals are mostly presynaptic to other CSAD-IR negative terminals. In the outer plexiform layer, CSAD-IR was found to be associated with synaptic vesicles and the synaptic membrane in certain cone pedicles and rod spherules. It is concluded that only a fraction of amacrine cells in rat retina may use GABA as a neurotransmitter. The presence of CSAD-IR in some amacrine, bipolar, photoreceptor and ganglion cells in rat retina is compatible with the notion that taurine may play some important roles, such as those of neurotransmitter or neuromodulator in mammalian retina.

Animals↗
PubMed1985

Immunoelectron microscopic demonstration of prostatic acid phosphatase in human hyperplastic prostate.

Immunoelectron microscopic studies were done on prostatic tissues obtained from patients with benign hyperplasia. Rabbit IgG-peroxidase conjugate against purified human prostatic acid phosphatase band 2 (HPAP-2) was used for studies. Under the light microscope, the columnar secretory epithelia of prostatic glands showed different intensity and distribution of immunostaining whereas the basal cells were unstained. Under the electron microscope, the secretory epithelial cells often showed electron-dense reaction product in the Golgi apparatus and secretory vesicles and vacuoles, and only sparingly in the cisternae of nuclear envelope and rough ER. Sometimes, fusion of secretory vacuolar membrane and plasma membrane and discharge of the vacuolar contents into the extracellular space were noted. The surfaces of microvilli at the apical portion of the columnar epithelia and the lumen of the glandular acini always showed reaction product. These findings suggest that HPAP-2 may be synthesized in the rough ER and transported to the Golgi apparatus where it is concentrated and transferred to the secretory vesicles and vacuoles. HPAP-2 is finally discharged into the extracellular spaces through exocytosis, a secretory mechanism similar to that of other secretory proteins.

Acid Phosphatase↗