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Biomedical subjects

X Zheng

Publications and source records attributed to X Zheng.

322 records · Page 18Linked to original sources
PubMed1991

[Pathological observation of experimental asbestosis treated by hydroxy piperquin phosphate in dogs].

The paper presents experimental asbestosis treated with hydroxy piperquin phosphate (HPQP) in dogs. Results showed that the total cell number of bronchoalveolar lavage fluid, the viability of alveolar macrophages and the enzyme activities of lactate dehydrogenase, acid phosphatase and beta-glucuronidase of alveolar macrophages in treated dogs were higher than those in exposed dogs, asbestos fibers contents in the lungs and the mean scores of lung lesions in the treated dogs were markedly less than those in the exposed dogs. These findings support that HPQP may play a role in protecting alveolar macrophages from damage and inhibiting the progression of lung fibrosis, and that the clinical application of HPQP is somehow evidenced by this study.

Animals↗
PubMed1991

[Observation on the contraction process of ovarioles of Anopheles sinensis and Anopheles anthropophagus after oviposition].

In order to know the process of ovariole contraction after oviposition in Anopheles sinensis and An. Anthropophagus, and to determine the relationship between the ovariole contraction and the physiological age, the observation was conducted in 1988. The laboratory-reared female mosquitoes after 3-5 days of eclosion were fed with mouse blood and were kept in separate finger tubes for oviposition. After oviposition, the mosquitoes were dissected at different time. 30 ovarioles for each mosquito were examined and recorded by Detinova's method. A total number of 75 An. sinensis with 2,262 ovarioles and 87 An. anthropophagus with 2,591 ovarioles were examined after first oviposition. The duration for ovariole contraction in the phase of A,B,C,D,E was 1, 3-6, 9-14, 15-18 and 21h respectively. A total number of 40 An. sinensis with 1,337 ovarioles and 34 An. anthropophagus with 1,099 ovarioles were examined after third oviposition. The duration for ovariole contraction in the phase of A,B,C,D,E was 1, 3-9, 12-15, 18 and 21h respectively. E phase can be found in 21-24h after oviposition. There were 29.3% and 38.0% ovarioles in C and D phase for first oviposition while 48.4% and 46.0% ovarioles in C and D phase for third oviposition. It was found that the contraction occurred first in breadth and then in length.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Kainate activated single channel currents as revealed by domoic acid.

We have studied the properties of kainic acid receptor-activated channels using domoic acid as an agonist. Similarities of the electrophysiological, pharmacological and noise properties of domoic acid and kainic acid-evoked currents confirm that domoate is a potent and specific agonist of the kainate receptor. Single-channel properties of domoic acid-evoked currents were directly determined from outside-out membrane patches for the first time, and results were compared with those obtained by fluctuation analysis of macroscopic currents. Small conductance cationic-selective channels of approximately 4 pS and a mean open time of 2 to 3 ms were detected using both methods.

Animals↗
PubMed1990

The effect of in utero ethinyl oestradiol exposure on the risk of cryptorchid testis and testicular teratoma in mice.

Epidemiological findings indicate that both cryptorchid testis and testicular germ cell cancer may be a result of high maternal oestrogen levels early in pregnancy. An experiment was conducted with a mouse strain (129 Sv-S1 C P) in which the males are susceptible to testicular teratomas to determine if the frequency of undescended testis and testicular teratoma in male offspring could be increased by administration of ethinyl oestradiol (EE) to pregnant mice before day 13 of gestation. This point in gestation marks the completion of the migration of germ cells to the gonadal ridge in mice and other studies with these mice have shown that the tumours are initiated in this critical time period. EE mixed with corn oil was administered by subcutaneous injection in doses of 0.02 (n = 76) and 0.2 (n = 102) mg kg-1 of body weight on gestational days 11 and 12. These mice were allowed to deliver their offspring and the males were killed at 15 days of age. Since the tumours are present from birth, this amount of time was allowed to permit the tumours to reach sufficient size for easy visual identification. Compared to controls (n = 63), who received corn oil alone, the treated mothers produced offspring who were significantly more likely to have a cryptorchid testis (P = 0.0001) and who had an increased risk, although not significant, of a testicular teratoma.

Animals↗
PubMed1990

[Pharmacological studies of huomaisan].

After per os Huomaisan twice a day for 5 days, HMS significantly prolonged thrombus formation time and inhibited platelet aggregation induced by ADP and collagen. Meanwhile, HMS also decreased blood viscosity, but did not significantly affect hematocrit. The result shows that HMS has multiple actions on blood.

Animals↗
PubMed1990

[Determination of metoprolol in plasma by gas chromatography and electron-capture detection].

A method is described to determine metoprolol in plasma by GC-ECD. Metoprolol and alprenolol (internal standard) reacted rapidly with heptafluorobutyric anhydride under the catalysis of tetrahydrofuran (THF) after being extracted from plasma with cyclohexane. The derivatives produced quantitatively were identified by GC-MSD to be diheptafluorobutyl metoprolol and dihepatafluorobutyl alpredolol which were then separated and detected by 3% SE-30 packed glass column (2m x 3 mm) equipped with ECD. The detection limit was 1 ng/ml and the linear range was 10-1500 ng/ml (r = 0.9993). Average recovery from spiked plasma was 97.30%. The coefficient of variation of day-to-day and within-day were less than 8% and 7%, respectively. The method has been applied to investigate the pharmacokinetics and bioavailability of metoprolol and also applied to clinical monitoring of metoprolol levels in patients.

Chromatography, Gas↗
PubMed1989

In vitro capacitation and fertilizing ability of ejaculated rabbit sperm treated with lysophosphatidylcholine.

Four experiments were replicated 1) to establish dose-response relationships between lysophosphatidylcholine (LPC), sperm motility, and the acrosome reaction (AR), 2) to evaluate the influence of rabbit serum (RS) on these endpoints, 3) to compare buck differences in induction of the AR, and 4) to examine fertilizing ability in vitro of sperm tested under the first three objectives. Semen was collected from Dutch-belted rabbits, washed once by centrifugation, resuspended, and preincubated for 2 or 4 hr in a chemically defined medium (DM), DM plus 20% RS, or BSA-free DM plus 20% RS at 37 degrees C. At the end of preincubation LPC was added to the preincubated sperm at concentrations of from 0 to 100 micrograms/ml. Sperm were examined .5-4 hr later for AR and sperm motility. For in vitro fertilization, sperm and ova were coincubated in DM up to 24 hr after insemination and in a more complex medium for another 24 hr. Addition of LPC to 4-hr-preincubated sperm was more effective for inducing the AR than addition to 2-hr-preincubated sperm. A significant increase (P less than .05) in the AR occurred in 15 and 30 min following exposure to 100 and 80 micrograms of LPC per ml, respectively, but the higher concentration of LPC decreased sperm motility. Addition of 20% RS to DM with or without BSA surprisingly inhibited the AR but maintained sperm motility, as expected. Bucks differed (P less than .05) in the initial percentage and the induced percentage of AR sperm. For the AR the optimal concentration of LPC per ml was 80 micrograms, but for in vitro fertilization 60 micrograms tended to be superior.

Animals↗
PubMed1989

Evidence in a lethal infantile mitochondrial disease for a nuclear mutation affecting respiratory complexes I and IV.

A child died at 4 months of age of a lethal infantile mitochondrial disease associated with cardiomyopathy. Detailed pathologic evaluation of this patient revealed abnormalities in the striated muscle, smooth muscle, heart, and liver, but not the central nervous system. Biochemical analysis revealed a combined complex I and IV deficiency in skeletal muscle, heart, and liver, but not in kidney and brain. Analysis of mitochondrial translation products and mitochondrial DNA failed to detect any abnormality. Parallel studies on both parents were uniformly normal. These data support the hypothesis that this disease was the result of a nuclear DNA mutation in a developmental stage-specific and tissue-specific oxidative phosphorylation-gene.

Cardiomyopathies↗
PubMedDate not supplied

Reactivation of herpes virus after lamellar keratoplasty.

PURPOSE: To determine if lamellar keratoplasty in rabbits latently infected with herpes simplex virus type 1 (HSV-1) would stimulate graft recipients to shed virus and induce viral-specific corneal lesions. METHODS: Rabbits latently infected with HSV-1 received lamellar allografts in one eye from normal uninfected rabbits and the contralateral eyes served as unoperated controls. Normal rabbits received lamellar grafts from rabbits latently infected with HSV-1. For 1 week after surgery, slit-lamp examination and ocular swab sampling were performed daily to assess viral reactivation. RESULTS: The occurrence of positive swab cultures and corneal epithelial lesions after lamellar keratoplasty was significantly higher in operated eyes of latently infected rabbits when compared to the control eyes. Ocular shedding or recurrent lesions were not observed in the normal rabbits receiving corneal grafts from latently infected donors. CONCLUSIONS: These results indicated that lamellar keratoplasty induces HSV-1 shedding and recurrent epithelial lesions in the eyes of rabbits latently infected with HSV-1, which received lamellar grafts, but not in the eyes of normal rabbits given lamellar grafts from HSV-1 latently infected rabbits. It seems that the site of viral latency is not the anterior corneal stroma or the epithelium.

Animals↗
PubMedDate not supplied

Expression of P-glycoprotein 170 in nasal mucosa may be increased with topical steroids.

The synthesis of P-glycoprotein 170 (P-gp), a "multidrug resistance" protein capable of extruding various drugs including 11-OH steroids from human cells, can be upregulated by certain glucocorticosteroids. This study demonstrates the presence of P-gp in the columnar surface epithelium and in glandular acini of healthy nasal mucosa with immunohistochemical technique. Furthermore, nasal polyps from 5 of 17 patients treated with clinical doses of a topical nasal steroid, budesonide, appear to show a stronger staining intensity for P-gp than polyps from 13 untreated patients. This suggests the possibility of local P-gp gene induction by topical glucocorticoid treatment. Upregulation of P-gp synthesis appears as a new possible cause of relative resistance to topical steroid medication in patients with nasal inflammatory disease.

ATP Binding Cassette Transporter, Subfamily B, Mem↗