Biomedical subjects

Q P Wang

Publications and source records attributed to Q P Wang.

At least 19 recordsLinked to original sources

PubMed2002

Endomorphin-2 immunoreactivity in the cervical dorsal horn of the rat spinal cord at the electron microscopic level.

Endomorphin-2 is a newly discovered endogenous opioid peptide with high affinity and selectivity for the micro-opioid receptor, and potent analgesic activity, particularly in the spinal cord. Using immunoelectron microscopy, we examined the ultrastructure of the endomorphin-2-like immunoreactive processes and their synaptic relationships in the spinal cord. Endomorphin-2-like immunopositive dense-cored vesicles were observed in many axon terminals, and, in a few cases, were observed together with immunonegative dense-cored vesicles. Immunopositive axons with or without myelination were also observed. The endomorphin-2-like immunoreactive axon terminals formed synapses with both immunopositive and immunonegative processes. Most synapses were asymmetrical, but symmetrical synapses were also found. Examples of axo-dendritic, axo-somatic and axo-axonic contacts were observed. This first demonstration of the ultrastructure and synaptic relationships of endomorphin-2-like immunoreactive axon terminals in the spinal cord dorsal horn provides morphological evidence that this peptide functions as a transmitter regulating pain processes.

Animals↗

PubMed2001

Immunoelectron microscopic study of beta-endorphinergic synaptic innervation of GABAergic neurons in the dorsal raphe nucleus.

Using a preembedding double immunoreactive technique by immunostaining with antirat beta-endorphin and antisynthetic glutamic acid decarboxylase antisera sequentially, the synaptic relationships between beta-endorphinergic neuronal fibers and GABAergic neurons in the dorsal raphe nucleus of the rat were examined at the ultrastructural level. Although both beta-endorphin-like immunoreactive fibers and glutamic acid decarboxylase-like immunoreactive neurons can be found in the mediodorsal and medioventral parts of the dorsal raphe nucleus, the synapses between them were found only in the mediodorsal part. Most of the beta-endorphin-like immunoreactive neuronal fibers contained many dense-cored vesicles. The synapses made by beta-endorphin-like immunoreactive neuronal axon terminals on glutamic acid decarboxylase-like immunoreactive neurons were both symmetrical and asymmetrical, with the latter predominant, especially in the axo-dendritic synapses. Perikarya with beta-endorphin-like immunoreactivity were found only in the ventrobasal hypothalamus. These findings suggest the possibility that the beta-endorphin-producing neurons in the ventrobasal hypothalamus could influence GABAergic neurons in the dorsal raphe nucleus directly by synaptic relationships.

Animals↗

PubMed2001

Orexinergic innervation of POMC-containing neurons in the rat arcuate nucleus.

A pre-embedding double immunostaining technique was used to study the synaptic relationships between orexin-like immunoreactive axon terminals and preopiomelanocortin (POMC)-like immunoreactive neurons in the rat arcuate nucleus. Most of the synapses were axo-dendritic, while some axo-somatic synapses were also found. Both the axo-somatic and axodendritic synapses were symmetrical. In some cases the presynaptic orexin-like immunoreactive axon terminals contained a few large dense-cored vesicles. The results suggest that the orexinergic axon terminals in the arcuate nucleus may play an important role in the regulation of food intake via synapses through POMC neurons.

Animals↗

PubMed2001

Reciprocal synaptic relationships between angiotensin II-containing neurons and enkephalinergic neurons in the rat area postrema.

A preembedding double immunostaining technique was used to study synaptic relationships between angiotensin-II-like immunoreactive and enkephalin-like immunoreactive neurons in the rat area postrema. The angiotensin-II-like immunoreactive neurons were detected by silver-gold intensification of the DAB reaction results while the enkephalin-like immunoreactive neurons were detected by simple ABC-DAB reaction. The synaptic relationships were reciprocal between the two neurons. Most of the synapses found between these two neurons were the presynaptic enkephalin-like immunoreactive axon terminals that made synapses on the angiotensin-II-like immunoreactive perikarya and dendrites. Both the axo-somatic and axo-dendritic synapses were symmetrical. However, although angiotensin-II-like immunoreactive axon terminals also made synapses on enkephalin-like perikarya and dendrites, the axo-somatic synapses were symmetrical, while the axo-dendritic synapses were asymmetrical. The present results confirm the presence of angiotensin-II-like immunoreactive neurons in the area postrema and suggest that these angiotensinergic neurons in the area postrema may play a role in the regulation of blood pressure via coordinated synaptic interactions with enkephalinergic neurons.

Angiotensin II↗

PubMed2000

Observation of the ultrastructure and synaptic relationships of angiotensin II-like immunoreactive neurons in the rat area postrema.

The ultrastructure and synaptic relationships of the angiotensin II-containing neurons in the area postrema of the rat were studied by immunocytochemistry using the avidin-biotin-complex-DAB method, and also using silver-gold intensification following the DAB reaction. At the light microscopic level, the angiotensin II-like immunoreactive neurons were observed within the area postrema, especially in the upper region. At the electron microscopic level, the angiotensin II-like immunoreactive cell bodies were observed as having a round, unindented nucleus. The nuclei of these neurons were not immunostained. The angiotensin II-like immunoreactive axon terminals often contained a few dense core vesicles in addition to many small clear synaptic vesicles. Numerous axon terminals were found to make synapses on immunonegative dendrites; they were also found to make synapses on angiotensin II-like immunoreactive dendrites. Many angiotensin II-like immunoreactive dendrites received synapses from immunonegative axon terminals. Although angiotensin II-like immunoreactive cell bodies were sometimes postsynaptic to immunoreactive axon terminals, they did not receive synapses from immunonegative axon terminals. These results provide solid morphological evidence of AP endogenous angiotensin II and confirm that in spite of circulating angiotensin II, the local neurons in the AP may also play an important role in angiotensin II-induced cardiovascular regulation.

Angiotensin II↗

PubMed2000

Synaptic contacts between serotonergic and cholinergic neurons in the rat dorsal raphe nucleus and laterodorsal tegmental nucleus.

We examined synaptic connectivity between cholinergic and serotonergic neurons in the dorsal raphe nucleus and the laterodorsal tegmental nucleus of the rat. To this purpose we employed two variations (the combination of pre-embedding immunogold-silver intensification with avidin-biotin-peroxidase complex technique and the combination of avidin-biotin-peroxidase/3, 3'-diaminobenzidine/silver-gold intensification with avidin-biotin-peroxidase/3,3'-diaminobenzidine reaction) of a double pre-embedding immunoelectron procedure, using primary antibodies against vesicular acetylcholine transporter and serotonin. At the light-microscopic level, serotonin-like immunoreactive neurons in the dorsal raphe nucleus appeared as reddish black and vesicular acetylcholine transporter-like immunoreactive axon terminals were brown colored using a combination of pre-embedding immunogold-silver technique and avidin-biotin-peroxidase complex technique. Serotonin-like immunoreactive fibers projected to the laterodorsal tegmental nucleus. At the electron microscopy level, with both methods we observed in the dorsal raphe nucleus vesicular acetylcholine transporter-immunopositive axon terminals in synaptic contact with serotonin-like immunoreactive dendrites and, to a lesser degree, with serotonin-like immunoreactive cell bodies. These synapses usually were of the symmetrical type. Occasionally we noted, next to vesicular acetylcholine transporter-immunopositive axon terminals, also immunonegative terminals synapsing with the serotonin-like immunoreactive dendrites. In the laterodorsal tegmental nucleus we found serotonin-like immunoreactive axon terminals and immunonegative terminals forming synapses with vesicular acetylcholine transporter-immunoreactive dendrites. Most synapses formed by the serotonin-like immunopositive terminals were of the asymmetrical type. Our results suggest that serotonergic neurons in the dorsal raphe nucleus and cholinergic neurons in the laterodorsal tegmental nucleus may reciprocally influence each other by means of synaptic connectivity. Such connectivity may serve to regulate pain sensation, or be involved in the regulation of the sleeping-waking cycle.

Acetylcholine↗

PubMed1999

The neurotensinergic synaptic innervation of vasopressin containing neurons in the rat hypothalamic paraventricular nucleus.

A recent physiological report suggested that neurotensin could inhibit the vasopressin releasing from vasopressin-producing neurons in the hypothalamic paraventricular nucleus but not in the supraoptic nucleus. In the present study, the synaptic relationship between the neurotensin-like immunoreactive and vasopressin-like immunoreactive neurons has been examined using a pre-embedding double immunostaining technique in the rat hypothalamic paraventricular nucleus. At the light microscopic level, many neurotensin-like immunoreactive fibers were found near the vasopressin-like immunoreactive neurons. At the electron microscopic level, the neurotensin-like immunoreactive fibers were identified as axon terminals that made many synapses on the vasopressin-like immunoreactive perikarya and dendrites. The synapses were both asymmetrical and symmetrical. These findings of the present study suggest that the inhibitory effect of neurotensin on the vasopressin neurons in the hypothalamic paraventricular nucleus may be due to the direct synapses made by neurotensin-like immunoreactive axon terminals on the vasopressin-like immunoreactive neurons.

Animals↗

PubMed1999

Electron microscopic observation of mu-opioid receptor in the rat area postrema.

A simple preembedding avidin-biotin-peroxidase complex technique was used to study the ultrastructural localization of mu-opioid receptor in the rat area postrema. By using low concentrations of the first antiserum for incubation with a short reaction time to 3,3'-diaminobenzidine, the immunostaining was faint at the light microscopic level. However, at the electron microscopic level, strong immunoreaction was observed. Mu-Opioid receptors were found to be localized on the postsynaptic membrane of dendrites, extrasynaptic plasma membrane, and the surface of the small, clear vesicles in axon terminals. Of the total 283 immunopositive profiles observed, 68.2% (193 of 283) were dendrites, 29.3% (83 of 283) were axon terminals, and 2.5% (7 of 283) were myelinated axons. No immunostained neuron bodies were found in the present study; 109 mu-opioid receptor immunoreactive dendrites received synapses (56.5%, 109 of 193) from nonimmunoreactive (84.4%, 92 of 109) or immunoreactive (15.6%, 17 of 109) axon terminals, whereas 84 dendrites (43.5%, 84 of 193) were found without receiving synapses. The present study shows that the mu-opioid receptor in the area postrema plays a role mainly at the synapses.

Animals↗

PubMed1998

Beta-endorphinergic innervation of mu and delta receptor containing neurons in the dorsal raphe nucleus.

A pre-embedding double immunostaining technique was used to determine the role of beta-endorphin in synapse, particularly in neurons with a postsynaptic membrane containing micro-1 or delta-1 opioid receptors. A small number of beta-endorphin immunoreactive axon terminals in the dorsal raphe nucleus was found to make direct synapses on micro-1 or delta-1 opioid receptor-immunoreactive dendrites, some of which showed immunostaining of their postsynaptic membranes, although with low frequencies. These results suggest that beta-endorphin can play a direct role through the micro-1 or delta-1 opioid receptors at synapses, but the main route would be through other opioid receptor at the synapse or even not through the synapse.

Animals↗

PubMed1998

Expression of the transforming growth factor beta isoforms in inflammatory cells of nasal polyps.

OBJECTIVE: To determine the expression and the potential role of transforming growth factor beta (TGF-beta) in nasal polyposis. DESIGN: Comparison of TGF-beta expression between normal and inflammatory nasal mucosa and polyps; in inflammatory nasal polyps, characterization of the TGF-beta isoforms expression and their potential location in macrophages and eosinophils. SETTING: Patients and samples were selected at the Hôpital Intercommunal, Créteil, France, and immunohistochemistry and immunoblots were performed at the Institut National de la Sante et de la Recherche Medicale U296 (Universite Paris XII, France). SUBJECTS: Nasal polyps and nasal mucosa were sampled in 21 patients during ethmoidectomy, and muscosa was sampled in 6 healthy patients during rhinoplasty. METHODS: Immunohistochemistry and Western blot analysis were performed using specific antibodies to TGF-beta1-3, TGF-beta1, TGF-beta2, and TGF-beta3 isoforms. Double labeling was also performed using anti-TGF-beta1 antibody together with macrophages or eosinophil-specific antibodies. RESULTS: The expression of TGF-beta(1-3) was significantly higher in inflammatory nasal polyps than in inflammatory nasal mucosa and higher in inflammatory nasal mucosa than in nasal mucosa from healthy patients. Transforming growth factor beta1 was the main isoform detected in inflammatory nasal polyps, and it was present in numerous macrophages and in some eosinophils. CONCLUSIONS: Transforming growth factor beta, mainly TGF-beta1, is strongly expressed in inflammatory nasal mucosa, where it could be produced by macrophages and eosinophils. Transforming growth factor beta could induce epithelium and connective tissue modifications and therefore be involved in the pathogenesis of nasal polyposis.

Adult↗

PubMed1998

Ultrastructural localization of mu-1 opioid receptor in the dorsal raphe nucleus of the rat.

A simple pre-embedding avidin-biotin-peroxidase complex technique was used to study the ultrastructural localization of mu-1 opioid receptor in the rat dorsal raphe nucleus. Using low concentrations of the first antiserum for incubation with a short reaction time to 3,3'-diaminobenzidine, the immunostaining was faint at the light microscopic level. However, at the electron microscopic level strong immunoreaction was observed. Mu-1 opioid receptors were found to be localized on the postsynaptic membrane of dendrites, extra-synaptic plasma membrane, and the surface of the small, clear vesicles in axon terminals. Of the total 407 immunopositive profiles observed, 76.4% (311/407) were dendrites and 18.9% (77/407) were axon terminals. The immunostained myelinated axons and perikarya were relatively rare, with frequencies of 1.0% (4/407) and 3.7% (15/407), respectively. About 50.8% of the immunopositive dendrites (158/311) were immunostained having their MOR-LI results beneath the postsynaptic membrane, although about 19.6% of them (31/158) also exhibited MOR-LI on other components, including the extrasynaptic plasma membrane. Other immunopositive dendrites showed staining in some other contents, including extrasynaptic plasma membrane (82/311, 26.4%) or not on the plasma membranes (71/311, 22.8%). Less than half of the immunopositive axon terminals (35/77, 45.5%) were found to make synapses with nonimmunoreactive dendrites (31/77, 40.3%) or immunopositive dendrites (4/77, 5.2%); none were found to make synapses with immunoreactive perikarya. The present study shows that mu-1 opioid receptor in the dorsal raphe nucleus plays a role at both synapse or not.

Animals↗

PubMed1998

An electron microscopic observation of the vesicular acetylcholine transporter-immunoreactive fibers in the rat dorsal raphe nucleus.

By using immunocytochemistry with an antibody directed against the vesicular acetylcholine transporter, many cholinergic neuronal processes were found to be immunopositive in the dorsal raphe nucleus. At the electron microscopic level, most of these processes were found to be axons. The immunopositive axon terminals made synapses on immunonegative dendrites and their spines whereas rare synapses were found between the immunopositive axon terminals and the immunonegative neuronal perikarya. Occasionally, the dendrites postsynaptic to an immunopositive axon terminal also received a synapse from an immunonegative axon terminal. The synapses made by the immunopositive axon terminals were usually symmetric and had a short active zone. Fewer immunostained dendrites were found, and they usually received asymmetric synapses from nonimmunostained axon terminals. The existence of cholinergic axon terminals and the synapses made by these terminals support the physiological data indicating that acetylcholine plays a role in the pain inhibition system in the dorsal raphe nucleus.

Animals↗

PubMed1997

Intertransverse approach for extraforaminal herniations.

STUDY DESIGN: This case report illustrates three patients with extraforaminal disc herniation in the lumbar spine. OBJECTIVES: Treatment consisted of discectomy through an intertransverse approach. SUMMARY OF BACKGROUND DATA: The surgical treatment of lumbar disc herniation has been well studied and reported in the literature. Laminectomy, foraminotomy, and facetectomy have traditionally been used for extraforaminal disc herniation. Intertransverse discectomy used in these three patients confirms the benefits of this approach. SURGICAL METHOD: A midline incision was made, and the paraspinous muscles on the affected side were detached to expose the appropriate laminae, facets, transverse processes, and intertransverse ligament. After resecting the ligament and retracting the compressed spinal nerve outside the facet, the nucleus pulposus was removed. RESULTS: Postoperative results were satisfactory. Weakness and low back and leg pain disappeared rapidly. The three patients returned to work 2-3 months postoperatively. CONCLUSIONS: The patho-anatomical characteristic of the entity is compression of the spinal nerve outside the foramen. Intertransverse discectomy is a rational technique-its advantages are that the spinal canal is not opened, spine stability is maintained, and multiple disc herniation can be managed through a single posterior midline incision.

Female↗

PubMed1997

Electron microscopic study of GABAergic synaptic innervation of nitric oxide synthase immunoreactive neurons in the dorsal raphe nucleus in the rat.

A double immunocytochemical method combining the preembedding avidin biotin peroxidase complex technique and the postembedding immunogold technique was used to examine synaptic interactions between GABAergic and nitric oxide synthase containing neurons in the same tissue sections of the dorsal raphe nucleus of the Wistar white rat. Although a large number of immunogold stained GABAergic axon terminals were found to be presynaptic to dendrites containing nitric oxide synthase-like immunoreaction product, synapses between GABA-like immunoreactive axon terminals and nitric oxide synthase-like immunoreactive perikarya were rare. The labeled boutons were found to make symmetrical and asymmetrical synapses. No axo-axonic synapse was found. These results suggest that GABAergic neurons could modulate nitric oxide producing neurons in the dorsal raphe nucleus through direct synaptic relations.

Animals↗

PubMed1997

Ultrastructural localization of delta-1 opioid receptor in the dorsal raphe nucleus of the rat.

The ultrastructural localization of delta-1 opioid receptor in the rat dorsal raphe nucleus was studied by the preembedding avidin-biotin-peroxidase complex technique. With application of a low concentration of the first antiserum in incubation and control of short-time reaction to 3,3'-diaminobenzidine, the immunoreaction seemed to be faint at the light microscopic level. At the electron microscopic level, however, delta-1 opioid receptor immunoreaction products were found to be localized specifically on the postsynaptic membrane of dendrites, dense-cored vesicles, and the surface of the small, clear vesicles in axon terminals with strong immunoreactivity. Of the total 659 immunopositive profiles observed, up to 62.4% (411/659) were dendrites, whereas 33.8% (223/659) were axon terminals. The immunostained myelinated axons and perikarya were relatively rare, with the frequencies 0.8% (5/659) and 3.0% (20/659), respectively. Most of the immunopositive dendrites (338/411, 82.2%) were immunostained only at the postsynaptic membranes. Other immunoreactive dendrites showed their immunoreaction products also in some other contents besides the postsynaptic membranes (44/411, 10.7%) or only in those contents but not the postsynaptic membranes (25/411, 6.1%). Only four dendrites showed their immunoreactive results only at the membrane not related to synapse (4/267, 1.0%). No dendrite was found immunostained in all the contents. About half of the immunopositive axon terminals (125/223, 56.1%) were found to make synapse with nonimmunoreactive dendrites (76/223, 34.1%) or immunoreactive dendrites (49/223, 22.0%), while only one was found to make contact with immunoreactive perikarya. The present study showed that delta-1 opioid receptor in the dorsal raphe nucleus is mostly localized on postsynaptic membrane; the main function of the delta-1 receptor in the dorsal raphe nucleus is to receive signals from the opioid-containing axon terminals through synapses.

Animals↗

PubMed1997

Electron microscopic observation of delta-opioid receptor-1 in the rat area postrema.

The ultrastructural localization of delta-1-opioid-receptor in the rat area postrema was quantitatively studied by pre-embedding avidin-biotin-peroxidase-complex technique. Most of the immunoreactive profiles (67.4%) observed in the present study were axon terminals, whereas the immunopositive dendrites were less (28.3%). Within the axon terminals, the immunoreactivity was found stronger in the dense-cored vesicles than in the small, clear, and round vesicles. Almost 2/3 of the DOR-1 immunoreactive axon terminals had DAB reacted dense-cored vesicles. About half of the immunopositive axon terminals were found to make synapse to dendrites. The dendrites postsynaptic to DOR-1 immunoreactive axon terminals were identified as DOR-1 immunoreactive or not, mainly according to the immunoreactive appearance of the postsynaptic membrane. About half of the DOR-1 immunoreactive dendrites were observed to receive synapse: most of them have their immunoreactivity results at the postsynaptic membranes.

Animals↗

PubMed1997

Myofibroblast accumulation induced by transforming growth factor-beta is involved in the pathogenesis of nasal polyps.

Myofibroblasts that express alpha-smooth muscle actin (alpha-SMA) are detected in many chronic inflammatory diseases. Transforming growth factor-beta (TGF-beta) is a potent inducer of myofibroblast accumulation in tissues. In this study, scattered myofibroblasts and TGF-beta were quantified and localized in nasal polyps (NPs) and normal nasal mucosa (NM). NPs were sampled in 16 patients during ethmoidectomy and NM was obtained from 10 control subjects during rhinoplasty. alpha-SMA and TGF-beta were detected using immunohistochemistry and the numbers of labeled cells were quantified (alpha-SMA and TGF-beta indices) and compared between NPs and NM. In eight NPs, in which the pedicle was preserved, alpha-SMA and TGF-beta were evaluated and compared in the pedicle, central, and tip areas. Finally, TGF-beta expression was compared between low (zone 1), moderate (zone 2), and high (zone 3) zones of alpha-SMA positivity. alpha-SMA and TGF-beta indices were significantly higher in NPs than in NM. In the eight selected NPs, alpha-SMA-positive cells were significantly more abundant in the pedicle than in the central and tip areas, whereas TGF-beta-positive cells were significantly more numerous in the pedicle than in the tip area. The number of TGF-beta-positive cells was significantly higher in zone 3 than in zone 1 of alpha-SMA positivity. Myofibroblasts, which are abundant in NPs but rare in NM, could be involved in the growth of NPs by inducing extracellular matrix accumulation. The local development of myofibroblasts in NPs could be controlled by TGF-beta, locally produced by inflammatory cells.

Actins↗

PubMed1996

Electron microscopic study of GABAergic synaptic innervation of neurotensin-immunoreactive neurons in the dorsal raphe nucleus.

A double immunocytochemical method combining the preembedding avidin-biotin-peroxidase-complex technique and the postembedding immunogold technique was used to examine synaptic interactions between GABAergic and neurotensin-containing neurons in the same tissue sections of the dorsal raphe nucleus of the rat. Whereas the neurotensin-like immunoreactive perikarya rarely received synapses from GABA-like immunostaining axon terminals, the neurotensin-like immunoreactive dendrites frequently received synapses from GABA-like immunoreactive neurons. These results suggest that GABAergic neurons could modulate neurotensinergic neurons in the dorsal raphe nucleus through synaptic relations. The immunocytochemically identified local synaptic circuit in the dorsal raphe was discussed.

Animals↗