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Biomedical subjects

C Jiang

Publications and source records attributed to C Jiang.

At least 271 records · Page 15Linked to original sources
PubMed1991

Prolonged augmentation of respiratory discharge in hypoglossal motoneurons following superior laryngeal nerve stimulation.

Experiments were conducted to investigate long-lasting effects of brief superior laryngeal nerve (SLN) stimulation on respiratory discharge in the hypoglossal nerve. In paralyzed, decerebrate and artificially ventilated cats, SLN stimulation (Hz, 3-5, s, 3-5 times threshold for inhibition of phrenic nerve discharge) immediately increase hypoglossal activity. Following stimulation, the amplitude of respiratory activity in the hypoglossal nerve was augmented (478 +/- 205%), and slowly decayed to prestimulus levels with a time constant of 106 +/- 16 s. In contrast, phrenic nerve activity was completely inhibited during the SLN stimulation and for several seconds thereafter. After activity resumed, phrenic burst frequency remained depressed (33 +/- 6%). Stimulation of the carotid sinus nerve elicited similar effects on hypoglossal nerve activity. Intracellular recordings from hypoglossal motoneurons indicated that SLN stimulation increased central respiratory drive potentials (CRDPs) following a stimulus train, but had inconsistent effects on resting membrane potential. Intracellular depolarizing current pulses (5-15 nA; 2 s) had no prolonged effects on membrane potential or CRDPs. The possible role of serotonin in prolonged augmentation of hypoglossal activity following SLN stimulation was investigated. Intracellular injection of horseradish peroxidase (HRP) into hypoglossal motoneurons and immunohistochemistry for serotonin revealed some close appositions between serotonin immunoreactive boutons and HRP-labeled neurons, but such appositions were sparse. Pretreatment with methysergide had little effect on prolonged augmentation of hypoglossal discharge following SLN stimulation. These results indicate that: (1) SLN stimulation causes prolonged augmentation of hypoglossal activity probably via increased synaptic inputs to hypoglossal motoneurons; and (2) serotonin is not necessary in the underlying mechanism.

Animals↗
PubMed1991

Dual fluorescence combined with a two-color immunoperoxidase technique: a new way of visualizing diverse neuronal elements.

A method is described that allows an estimation of the neurotransmitter-related immunoreactivity, morphology and relationship to other immunoreactive elements, of single functionally identified neurons in the central nervous system. First, neurons are identified electrophysiologically using intracellular recording and labelled by iontophoresis of lucifer yellow (LY). After fixation and sectioning of the brain tissue, the location of the labelled neuron is determined by fluorescence microscopy. Sections are then processed using an indirect immunofluorescence procedure in order to determine the antigen content of the labelled neurons. Antisera to LY and an avidin-biotin immunoperoxidase technique is then used to localize LY in a permanent form, while the other previously localized antigen is permanently visualised by using the fluorescent-labelled second antibody as a bridge antibody in a peroxidase anti-peroxidase technique. The method is illustrated by an examination of neurons in the medulla oblongata of the rat, that have been stained intracellularly with LY, their content of tyrosine hydroxylase assessed, and their relationship to other tyrosine hydroxylase immunoreactive neurons determined.

Animals↗
PubMed1991

Intracellular recording from respiratory neurones in the perfused 'in situ' rat brain.

The study describes an arterially perfused in situ rat brain preparation, which uses an 'open circuit' flow of blood substitute with or without an oxygen carrier (2% perfluorotributylamine). The respiratory motor output was recorded from the phrenic and hypoglossal nerves, and could be maintained for up to 11 h from the start of perfusion (temperature of perfusate: 27-30 degrees C). The preparation allowed stable intracellular recordings from respiratory neurons in the brain stem and cervical spinal cord, and should be suitable for other studies which cannot be performed in standard whole animal models. The advantages of this approach compared with other in vitro or perfused in situ preparations are discussed.

Animals↗
PubMed1991

Inhibition by barium and glibenclamide of the net loss of 86Rb+ from rabbit myocardium during hypoxia.

STUDY OBJECTIVE: The aim was to determine the effects of barium ions and glibenclamide on the hypoxia induced K+ efflux from rabbit myocardium. DESIGN: Experiments were performed on the isolated interventricular septum of the rabbit perfused with a physiological solution through the septal artery. The stimulation rate was 90 beats.min-1 and the temperature 32 degrees C. The flux of 86Rb+ was used as a surrogate of K+ fluxes. EXPERIMENTAL MATERIAL: Septa were obtained from adult male New Zealand white rabbits. MEASUREMENTS AND MAIN RESULTS: The uptake of 86Rb+ by the septum could be fitted to a single exponential curve with a rate constant of 0.024(SEM 0.001) min-1 (n = 14). Washout experiments were performed in which septa were labelled with 86Rb+ and then perfused with unlabelled solution for 60 min. The rate constants for the efflux of 86Rb+ were similar and were 0.022(0.001) min-1 (n = 13) for radioactivity in the tissue and 0.029(0.001) min-1 (n = 13) for radioactivity in the effluent. These rate constants were similar to those reported previously for 42K+. Septa were labelled for 150 to 180 min with 86Rb+ and then perfused with a hypoxic substrate free solution for 15 min followed by reoxygenation. The net loss of 86Rb+ was calculated to be equivalent to 4.00(0.20) mmol.kg-1 wet tissue of K+ (n = 8) and in washout experiments (n = 6) this loss was shown to be due to increased efflux. Ba2+, 0.1 mM and 1.0 mM, added at the onset of hypoxia decreased net tissue loss of 86Rb+ by 64(6)% (n = 5) and 97(1)% (n = 6) respectively (both p less than 0.01). Glibenclamide (0.1 mM) decreased tissue net loss by 52(3)% (n = 6, p less than 0.01). CONCLUSIONS: Part of hypoxia induced net K+ loss in this preparation can be attributed to activation of ATP sensitive K+ channels but other mechanisms are also involved.

Animals↗
PubMed1991

Effect of anoxia on intracellular and extracellular potassium activity in hypoglossal neurons in vitro.

1. A brain slice preparation was used to study the hypoglossal (XII) neuronal response to anoxia. Both intra- and extracellular potassium activities (K+i,K+o) were measured by the use of ion-selective microelectrodes, and K+ flux was assessed by the use of pharmacologic blockers. 2. Extracellular recordings showed that a short period of anoxia (4 min) induced an increase in K+o of 26.4 +/- 7.5 mM (mean +/- SD, n = 20) in the XII nucleus of adult rats. 3. Intracellular recordings (n = 31) in XII neurons showed a substantial decrease in K+i during anoxia. Fourteen neurons were analyzed in detail and these showed that XII neurons depolarized to -25.3 +/- 7.7 mV, whereas K+i dropped from 93.6 +/- 14.9 to 32 +/- 9.0 mM. These results strongly suggested that K+ is lost from XII neurons during anoxia. 4. Although the extracellular space (ECS) shrank by approximately 50% during anoxia, the possibility that the increase in K+o and decrease in K+i were mainly caused by shrinkage of the ECS and swelling of intraneuronal space was excluded to a great degree because the changes in K+i and K+o during anoxia were relatively very large. 5. To study the mechanisms by which K+ is lost from XII neurons, we used several pharmacologic blockers. High concentration of ouabain (10 mM) and strophanthidin (80 microM) increased K+o from baseline (3-4 mM) to 40.9 +/- 2.5 mM (n = 6) but did not abolish an additional anoxia-induced increase in K+o, suggesting that mechanisms other than Na(+)-K(+)-adenosine triphosphatase inhibition were also responsible for the anoxia-induced K+ leakage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Dynamic variation of saikosaponin contents].

In this paper both the cultivated and wild Bupleurum chinense and B. scorzonerifolium from northeast China of different growing periods and ages were analyzed for the contents of saikosaponins a and d by HPLC and total saikosaponins by spectrophotometry. The results indicated that the saikosaponin content of B. chinense was higher than that of B. scorzonerifolium, and that the saikosaponin contents of the cultivated species were higher than or almost equal to those of the wild ones. It was also found that both the cultivated and wild B. chinense and B. scorzonerifolium featured the highest contents of saikosaponins in the nutrition-growing period.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

The therapeutic and biological effects of total lymph node irradiation and autologous bone marrow infusion on malignant lymphoma patients.

Forty patients with malignant lymphoma were treated by 60Co total lymphoid irradiation (TLI): 21 cases received 6 Gy and 19 received 8 Gy. Ten also received autologous bone marrow infusion (ABMI). Acute radiation damage with digestive tract reaction and hemopoietic and immunological depression was observed. Bone marrow was depressed. WBC and platelets decreased rapidly. Lymphocytes showed quantitative and qualitative changes even at the early stage. All these symptoms subsided within 40 days. TLI accompanied by irradiation of the tumor site could result in effective control. The 1-, 3-, and 5-year survival rates of malignant lymphoma patients were 30/40 (75%), 14/24 (58%) and 4/12 (33%), respectively, while in those with Hodgkin's disease alone, the 1- and 3-year survival rates were 10/13 (76%) and 5/7 (71.4%), respectively. ABMI hastened hemopoietic reconstitution, which recovered relatively quickly after TLI.

Adolescent↗
PubMed1990

An intracellular study of respiratory neurons in the rostral ventrolateral medulla of the rat and their relationship to catecholamine-containing neurons.

Intracellular recording and labelling with Lucifer yellow of respiratory neurons in the rostral ventrolateral medulla were carried out in urethane-anaesthetised rats. A combined immunofluorescence and immunoperoxidase technique enabled an assessment of the tyrosine hydroxylase immunoreactivity, as well as an examination of the morphology of inspiratory and expiratory neurons in this part of the medulla oblongata. The results demonstrate: a) that respiratory neurons in the rostral ventrolateral medulla of the rat are intermingled with catecholamine-containing neurons of the C1 cell group, but are not themselves catecholamine-containing; b) that many non-spinally projecting respiratory neurons have axonal arborisations within the ventrolateral medulla in the same region as the C1 cell group, other respiratory neurons, and neurons reported to have a cardiovascular function; and c) that the dendrites of respiratory neurons in this region radiate throughout the ventrolateral medulla and frequently approach the ventral surface.

Animals↗
PubMed1990

GABA-immunoreactive boutons make synapses with inspiratory neurons of the dorsal respiratory group.

Intracellular labelling with horseradish peroxidase (HRP) combined with gamma-aminobutyric (GABA) immunocytochemistry was used to assess the GABAergic input to inspiratory bulbospinal neurons of the dorsal respiratory group in the cat. The relationship between GABA-immunoreactive (GABA-IR) boutons and intracellularly labelled neurons was examined at the light microscopic and ultrastructural levels. At the light microscopic level, GABA-IR boutons were frequently found in close apposition to dendrites and cell bodies of labelled neurons. The presence of synapses was confirmed with electron microscopy. In addition, synaptic specializations were observed between immunoreactive boutons and unlabelled terminals which in turn formed synaptic contacts with HRP-labelled dendrites, a finding consistent with presynaptic inhibition. These results demonstrate a direct GABAergic input to a functionally defined population of medullary respiratory neurons, and suggest involvement of this neurotransmitter in the control of these neurons.

Animals↗
PubMed1990

Serotonin immunoreactive boutons form close appositions with respiratory neurons of the dorsal respiratory group in the cat.

The aim of this study was to examine the location of serotonin immunoreactive boutons on both the soma and dendrites of neurons in the dorsal respiratory group by using a combination of intracellular recording and labelling and immunohistochemistry. Inspiratory neurons in the ventrolateral nucleus of the solitary tract (vl-NTS) were intracellularly labelled with horseradish peroxidase (HRP) in anaesthetised adult cats. The morphology of 23 neurons, all antidromically activated from the contralateral C3 spinal segment, was examined. Six neurons displayed pronounced dendritic arborizations outside the vl-NTS, with prominent dorsal and/or medial projections. The dendrites of the remaining neurons were almost entirely confined to the vl-NTS. Intramedullary axon collaterals were detected in four of nineteen examined axons. Serotoninergic fibres were immunohistochemically demonstrated in the NTS, and the apposition of immunoreactive boutons to the HRP-filled neurons examined at the light microscopic level. Boutons were identified in close apposition with the somata, proximal and distal dendrites of these neurons. However, the density of contacts was found to be substantially less than in a previous study of phrenic motoneurons (Lipski et al: Soc. Neurosci. Abst. 14:379, '88; Pilowsky et al: J. Neurosci. in press, '90). The relative paucity of contacts of serotonin immunoreactive boutons with premotor inspiratory neurons of the dorsal respiratory group indicates that the serotoninergic system affects respiratory pathways mainly at the level of respiratory motoneurons or at brainstem sites outside the vl-NTS.

Action Potentials↗
PubMed1990

Extensive monosynaptic inhibition of ventral respiratory group neurons by augmenting neurons in the Bötzinger complex in the cat.

Axonal projections and synaptic connectivity of expiratory Bötzinger neurons with an augmenting firing pattern (Bot-Aug neurons) to neurons in the ipsilateral ventral respiratory group (VRG) were studied in anaesthetized cats. Antidromic mapping revealed extensive axonal arborizations of Bot-Aug neurons (24 of 45) to the rostral or caudal VRG, with some having arbors in both regions. Of 234 pairs of neurons studied with intracellular recording and spike-triggered averaging, monosynaptic inhibitory postsynaptic potentials (IPSPs) were evoked in 49/221 VRG neurons by 38/98 Bot-Aug neurons. The highest incidence of monosynaptic inhibition was found in inspiratory bulbospinal neurons (10 of 23 tested). Evidence was also found for monosynaptic inhibition, by a separate group of Bot-Aug neurons, of expiratory bulbospinal neurons (12/58), while excitatory postsynaptic potentials (EPSPs) were identified in another two of these neurons. In addition, monosynaptic IPSPs were recorded from 13 of 53 identified laryngeal motoneurons, and from 14 of 100 respiratory propriobulbar neurons. Presumptive disynaptic IPSPs were recorded from 11 of the 221 VRG neurons. We conclude that Bot-Aug neurons exert widespread inhibition on all major neuron categories in the ipsilateral VRG, and should be regarded as an important element in shaping the spatiotemporal output pattern of both respiratory motoneurons and premotor neurons.

Animals↗
PubMed1990

[Application of acupuncture anesthesia during craniocerebral operation in temporo-fronto-occipital region].

The paper reports 174 cases of brain operations in temporo-fronto-occipital region by using the regime of combined acupuncture and medication. The patients comprised of 122 males and 52 females. The acupoints consisted of ear needling and body needling. Adjuvant drugs used were half-dosage Innovar and 0.1% lidocaine for scalp infiltration. According to the documented two-grade scaling criteria, 97.1% patients belonged to grade I. No obvious discrepancy existed between ear needling group and body needling one. Three controlled groups are presented for comparison: 1) 0.1% lidocaine alone; 2) acupuncture plus normal saline; 3) acupuncture plus 0.1% lidocaine. The resultant P value was less than 0.005, with remarkable statistical significance. It is revealed that 0.1% lidocaine per se cannot achieve satisfactory analgesia, whereas the efficacy of acupuncture can be greatly enhanced by the combination of 0.1% lidocaine and acupuncture. This method is proved as an effectual means to offset the incomplete analgesia of acupuncture, especially for those requiring intraoperative demonstration of surgical effects, to avoid impairment to functional areas of cerebral cortex, which are undoubtedly superior to general anesthesia.

Acupuncture Analgesia↗
PubMed1989

Studies on social medicine and leprosy in east China.

Leprosy is a disease in which the social, economic, cultural and environmental factors play an important role in occurrence, spread, control, eradication and rehabilitation. Eliminating the unfavourable factors hindering leprosy control can make achieving the goal of basic eradication of leprosy in China before the end of this century possible. For this reason, since 1984 we have carried out systematic studies of the social aspects of leprosy in Baoying County, a former high-endemic area in Jiangsu Province of East China, where the endemicity of leprosy is nearing full control.

Adolescent↗
PubMed1988

Substrate properties of analogs of myo-inositol.

The hydrolysis of the minor cell membrane lipid phosphatidylinositol-4,5-bisphosphate mediates the action of many growth factors and hormones. As an approach to the development of specific inhibitors of this process, we have synthesized a series of analogs of myo-inositol and have evaluated their ability to serve as substrates for phosphatidylinositol synthetase. Modification at the 2-, 3-, or 4-positions produced compounds unable to serve as substrates, but several 5-modified analogs retained activity as substrates of phosphatidylinositol synthetase. The product formed from 5-deoxy-5-fluoro-myo-[3H]inositol by phatidylinositol synthetase was hydrolyzed by phospholipase D and gave 5-deoxy-5-fluoro-myo-inositol as the radiolabeled product. Two analogs, 5-deoxy-myo-inositol and 5-deoxy-5-fluoro-myo-inositol, were shown to permeate L1210 leukemia cells and be incorporated into cellular phospholipid. Analysis of the radiolabeled lipids formed on incubation of L1210 cells with 5-deoxy-5-fluoro-myo-[3H]inositol indicated that the fradulent lipid formed was further phosphorylated to the monophosphate but not to the diphosphate form.

CDP-Diacylglycerol-Inositol 3-Phosphatidyltransfer↗
PubMed1987

Antidromic mapping of descending axons of respiratory bulbospinal neurons in the nucleus tractus solitarius of the rabbit.

Antidromic mapping of the descending axons of the respiratory bulbospinal neurons in the region of the nucleus tractus solitarius (NTS) was performed on rabbits anesthetized with urethane. Among 177 units tested, 29 out of 87 inspiratory (I), 27 out of 84 expiratory (E) and 2 out of 6 phase-spanning units were identified as bulbospinal. A prominent feature of the bulbospinal pathway from the NTS in the rabbit is the abundance of ipsilateral descending axons. The axons rising from one side are situated in the ventrolateral and ventral funiculi of both sides. The axonal conduction velocities are about 25-35 m/s. Both I and E bulbospinal neurons can be divided into R alpha and R beta types according to 'no I inflation' and 'maintained E inflation' tests.

Animals↗