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Biomedical subjects

Q Huang

Publications and source records attributed to Q Huang.

At least 307 records · Page 17Linked to original sources
PubMed1991

Vestibular and cerebellar modulation of expiratory motor activities in the cat.

1. The purpose of our investigation was to evaluate the hypothesis that components of the vestibular and cerebellar systems regulate efferent respiratory-modulated activities of cranial and spinal nerves. The hypothesis was based upon the observation that spinal neural activities during expiration are greatly altered subsequent to a change in posture. 2. In decerebrate and paralysed cats, efferent activities were recorded from the central cut ends of the phrenic nerve, intercostal nerve, branch of the intercostal nerve innervating the triangularis sterni, cranial iliohypogastric (abdominal) nerve and recurrent laryngeal nerve. 3. Animals were artificially ventilated. Those with intact vagi were ventilated by a servo-respirator which produced changes in lung volume in parallel with alterations in integrated activity of the phrenic nerve. Animals with bilateral vagotomy were ventilated with a standard respirator. 4. Aspiration of the entire cerebellar cortex did not produce alterations in levels of neural activities; the respiratory frequency was increased modestly. Following ablation of the ventrolateral portion of corpus medullare and cerebellar peduncles, expiratory activities of spinal nerves were completely eliminated whereas inspiratory activities were not greatly altered. Results were similar in animals having either intact or sectioned vagi. 5. Electrical stimulation or chemical stimulation by glutamate of regions of the ventrolateral cerebellum produced little change in respiratory neural activities except when these stimulations were within the infracerebellar nucleus. Stimulations in this nucleus caused pronounced increases in expiratory activities of spinal nerves. Neither inspiratory activities of spinal nerves nor inspiratory or expiratory activities of the recurrent laryngeal nerve were altered. Studies in animals having intact or sectioned vagi yielded similar results. 6. Bilateral lesions of neurons in the infracerebellar nucleus by injections of kainic acid in animals having intact or sectioned vagi caused an irreversible loss of expiratory activities of spinal nerves with neither inspiratory spinal activities nor inspiratory and expiratory laryngeal activities being altered. Similar findings were obtained following unilateral ablation of the infracerebellar nucleus in vagotomized cats. However, in cats with intact vagi, unilateral ablation of the infracerebellar nucleus produced only transient changes in either inspiratory or expiratory neural activities.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1991

Use of monoclonal antibodies to identify cytochrome P450 isozymes in rat liver microsomes that hydroxylate N-nitrosomethylamylamine at each of six positions.

Inhibition of enzyme activity by monoclonal antibodies (MAbs) was used to indicate which cytochrome P450 isozymes in Sprague-Dawley rat liver microsomes catalyse hydroxylation of the oesophageal carcinogen N-nitrosomethyl-n-amylamine (NMAA) to give 2- to 5-hydroxy-NMAA (HO-NMAA), formaldehyde and pentaldehyde. Liver microsomes (0.3-0.6 mg protein) were incubated (15 min, 23 degrees C) with 0.4 mg MAb and, after adding NMAA to 6 mM, incubated for 20 min at 37 degrees C. Mixtures were analysed for HO-NMAAs by gas chromatography-thermal energy analysis and for aldehydes by high-performance liquid chromatography of their 2,4-dinitrophenylhydrazones. The percentage inhibition by each MAb indicates the percentage metabolism by the corresponding P450 isozyme(s). These results indicate that the MAb to P450 IIB1 cross-reacts with P450 IIE1 and that the MAb to male-specific constitutive IIC11 cross-reacts with female-specific IIC12. Taking this into account, the main results were as follows. With uninduced male microsomes, 4-hydroxylation was catalysed mainly by IIC11 and demethylation by IIC11 and IIE1. With uninduced female microsomes, P450s reacting with the MAb to IIC11 (probably mainly IIC12) were responsible for most of the 4-hydroxylation and demethylation. With 3-methylcholanthrene-induced male microsomes, most 3-hydroxylation and some depentylation were due to IA1 or IA2. With phenobarbital-induced microsomes, all six reactions, but especially 4-hydroxylation and depentylation, were largely due to IIB1. With Aroclor-induced microsomes, all six reactions were catalysed by IIB1 and IA1 or IA2. The role of P450 IIC11 in 4-(omega-1)-hydroxylation was striking.

Animals↗
PubMed1990

[The effect of ginger on serotonin induced hypothermia and diarrhea].

One of the important medicinal properties of ginger is known to remove chills caused by common cold and to warm body. In the present study, acetone extract of ginger at 100 mg/kg p.o. significantly inhibited serotonin (5-HT) induced hypothermia. Therefore, the active constituents of ginger were further examined. The acetone extract was functioned into 4 fractions by column chromatography. Fractions 1 and 2 showed significant activity. Fraction 2 was further purified and [6]-shogaol which was obtained from fraction 2-2, at 10 mg/kg p.o. was shown to inhibit 5-HT induced hypothermia. Anticathartic activity is known to be one of the medicinal effects of ginger. In the present study, acetone extract of ginger at 75 mg/kg p.o., significantly inhibited 5-HT induced diarrhea. In order to clarify the active constituents, the acetone extract was fractionated into 4 fractions by silica gel chromatography. Fractions 2 and 3, which was especially effective, were further purified and [6]-shogoal, [6]-dehydrogingerdione, [8]- and [10]-gingerol were found to have an anticathartic action. [6]-Shogaol was more potent than [6]-dehydrogingerdione, [8]- and [10]-gingerol.

Acetone↗
PubMed1989

Respiratory activities of intralaryngeal branches of the recurrent laryngeal nerve.

To distinguish experimentally between motor nerve activity destined for vocal cord abductor muscles and that bound for muscles that adduct the cords, we recorded efferent activities of intralaryngeal branches of the recurrent laryngeal nerve (RLN) in decerebrate, vagotomized, paralyzed, ventilated cats. Activities of the whole RLN and phrenic nerve were also recorded. Nerve activities were assessed at several steady-state end-tidal O2 and CO2 concentrations. The nerve to the thyroarytenoid (TA) muscle, a vocal cord adductor, was only slightly active under base-line (normocapnic, hyperoxic) conditions but in most cats developed strong activity during expiration in hypocapnia or hypoxia. In severe hypocapnia, phasic expiratory TA activity persisted even during phrenic apnea, indicating continuing activity of the respiratory rhythm generator. The nerve to the posterior cricoarytenoid (PCA) muscle, the vocal cord abductor, was always active in inspiration but often showed expiratory activity as well. This expiratory activity was usually enhanced by hypercapnia and often inhibited by hypoxia. The results are consistent with previous electromyographic findings and emphasize the importance of distinguishing abductor from adductor activity in studies of laryngeal control.

Animals↗
PubMed1989

Influence of lung volume on activities of branches of the recurrent laryngeal nerve.

To investigate the influence of inspiratory lung inflation on the respiratory activities of laryngeal motor nerves, vagally intact decerebrate paralyzed cats were ventilated by a servorespirator in accordance with their own phrenic nerve activity. Records were made of the activities of the phrenic nerve, the superior laryngeal nerve (SLN), the recurrent laryngeal nerve (RLN), and the intralaryngeal branches of the RLN serving the thyroarytenoid (TA) and posterior cricoarytenoid (PCA) muscles. Neural activities were assessed in the steady state at different end-tidal O2 and CO2 concentrations. Transient responses to withholding inspiratory lung inflation and to preventing expiratory lung emptying were also studied. Hypercapnia and hypoxia increased the inspiratory activities of the phrenic nerve, SLN, RLN, and its PCA branch. TA inspiratory activity was not changed. Expiratory activities of RLN, PCA, and TA were all increased in hypoxia. When lung inflation was withheld, neural inspiratory duration and the inspiratory activities of all nerves increased. The subsequent period of neural expiration was marked by an exaggerated burst of activity by the TA branch of the RLN. TA expiratory activity was also sharply increased after inspiratory efforts that were reflexly delayed by the prevention of lung emptying. TA activity in expiration was enhanced after vagotomy and was usually more prominent than when lung inflation was withheld before vagal section. The results demonstrate the importance and complexity of the influence of vagal afferents on laryngeal motor activity.

Afferent Pathways↗
PubMed1989

[Electron microscopic observation of the sporogonic stage of Plasmodium gallinaceum after five antimalarials].

Ultrastructural changes in Plasmodium gallinaceum oocysts and sporozoites were studies after 5 antimalarials (pyrimethamine, primaquine, artemisinine, 5-p-fluorobenzoxyl-primaquine citrate and nitroquine) were administered to Aedes albopictus. Obvious disfigurement, such as abnormal vacuoles of various sizes in the cytoplasma, thickened oocyst capsules and damaged sporozoite pellical membranes were found in many oocysts and sporozoites in the mosquitoes. When the grade of infection of sporozoites in the salivary glands of the 5 different groups of mosquitoes were compared with the control, the rank test (Hc = 271) showed a very significant variance (P less than 0.01).

Aedes↗
PubMed1989

[Assessment of intracutaneous test in longitudinal surveillance for lymphatic filariasis].

In order to evaluate the usefulness of intracutaneous test (IT) in longitudinal surveillance of filariasis, two administrative villages selected from Queshan County, Henan Province of China, endemic for Wuchereria bancrofti, were surveyed in 1982, 1983 and 1987 respectively, by IT with antigen FPT derived from Dirofilaria immitis. The result showed that the original level of IT to antigen FPT in the population was consistent with the data of either etiological or entomological investigation before chemotherapy. When the microfilaraemia rate and natural filarial infection rate of mosquitoes in a village were high, the positive rate and frequency of strong positivity (skin wheel diameter greater than or equal to 1.3 mm) for immediate hypersensitivity reaction would be high too; and the reverse was true. It is suggested that both criteria of IT mentioned above may be useful in assessing endemicity of lymphatic filariasis before mass chemotherapy. The speed of negative conversion of IT in both groups, the previously microfilaraemic patients and the microfilaraemic inhabitants positive to immediate hypersensitivity reaction before chemotherapy, were different, the former being significantly slower than that of the latter after mass and selective chemotherapy with diethylcarbamazine. All of the three criteria for immediate hypersensitivity, positive rate, frequency of strong positivity and positive conversion rate, decreased gradually after a mass and selective DEC treatment. Until 1987, the 5th year after the chemotherapy, the average positive rate in the two villages dropped to 20.0% from 55.4% in 1982, the frequency of strong positivity to 2.8% from 23.8% in 1982, and the positive conversion rate to 9.7% (1984-1987) form 19.2% (1982-1983).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Respiratory neural activities after caudal-to-rostral ablation of medullary regions.

The purpose is to assess the importance of medullary mechanisms for the neurogenesis of eupnea. Cats that were used were decerebrate, cerebellectomized, vagotomized, paralyzed, and ventilated. Activities of the phrenic, facial, and mylohyoid nerves were monitored. Progressive caudal-to-rostral transections of the spinal cord and medulla were performed. Phrenic activity was eliminated by C1 spinal transections. Only modest changes in facial and mylohyoid activities resulted from transections as far rostral as the level of the dorsal respiratory nucleus. Rhythmic discharges ceased on transections at the pontomedullary junction. However, rhythmic mylohyoid discharges were maintained if protriptyline and strychnine were administered before and during the transection. In other studies rhythmic phrenic, facial, and mylohyoid discharges continued, albeit with an altered rhythm, after destruction of neurons in the dorsal respiratory nucleus by kainic acid. We conclude that caudal medullary mechanisms do not play an essential role in the neurogenesis of breathing movements. Rather, structures in rostral medulla and pons appear necessary for sustaining eupneic neural activities. The concept of multiple brain stem sites for ventilatory neurogenesis is discussed.

Animals↗
PubMed1988

[Diagnosis and treatment of cerebral metastasis from lung cancer].

A clinical analysis of 38 patients with cerebral metastasis from lung cancer is reported 17 patients had primary cancer symptoms prior to the increased intracranial pressure 34 patients were examined by cerebral angiography or ventriculography and 4 by CT scan. The incidence of cerebral metastasis with lung as the primary focus ranks first (54.7%). Three pathologic processes of intracranial metastasis: (1) cancer cell thrombosis stage (2) growth reaction stage (3) increased intracranial pressure stage. In this series, 16 patients were given conservative treatment and 22 were operated by craniotomy and resection. The results show that the operation could improve the symptoms and signs and prolong the survival time. The surgical treatment of lesions in the brain is emphasized and the indications are discussed.

Adult↗
PubMed1987

[Establishment of human glioma cell line--nude mice solid tumor model NHG-1 and its characteristics].

Establishment and its characteristics of a nude mice solid tumor model NHG-1 from human glioma cell line are reported. 5-8 week old NC nude mice of both sexes and SHG-44 cell line used in this experiment were from our laboratory. The initial successful transplantation rate was 7/11 (64%) and that of 30 passages in the subsequent 4 years was 100%. After subcutaneous inoculation, growth curve showed a latent period in week 1-2, slow growing period in week 3-4, rapid growing period in week 5-6 and a final plateau period in week 7. The doubling time was 7 days and cell cycle time was 2.5 days. The cells in G1, S and G2M phases comprised 56%, 27% and 17%, respectively. The survival time of the host was 54 +/- 15 days. The tumor tissues showed a tendency towards invading the surrounding soft tissues. By morphological observation with light and electron microscopes, LDH isozyme assay, PAP immuno-histochemistry labelling GFAP and chromosome analysis, it is confirmed that the transplantable tumor possesses the characteristics of human malignant glioma. The estrogen receptor in the transplantable tumors demonstrated by cytochemical assay indicates that the glioma carcinogenesis is related to endocrine factor of the host. The therapeutic effects of anticancer drugs, such as ACNU, BCNU and 10-hydroxy-2-decenoic acid from the royal jelly on NHG-1 model are evaluated.

Animals↗