Biomedical subjects

Y Z Feng

Publications and source records attributed to Y Z Feng.

At least 19 recordsLinked to original sources

PubMed2001

[Addition internal standard method in chromatographic quantitative analysis].

Internal standard method is a conventional chromatographic quantitative method which requires one or several internal standards added. The internal standard component must not be contained in the sample and need a good separation between the internal standard and sample components. In many cases selecting an internal standard is not convenient or even restricted by the seperation of components. In this paper, we try to combine the internal standard method and the addition method to form a new chromatographic quantitation method named addition internal standard method. The principles of addition internal standard method are suitable to not only chromatographic quantitation but also polarography etc. The related theory and foundation of the method are defined. The operation steps and the conditions suitable to the method are discussed. The advantages and disadvantages of this method are explained in detail.

Chromatography↗

PubMed1998

The role of glutamate in the locus coeruleus during opioid withdrawal and effects of H-7, a protein kinase inhibitor, on the action of glutamate in rats.

To investigate the role of glutamate in the locus coeruleus (LC) during opioid withdrawal, rats were continuously infused with morphine (a mu-opioid receptor agonist, 26 nmol/microl/h) or butorphanol (a mu/delta/kappa-mixed opioid receptor agonist, 26 nmol/microl/h) intracerebroventricularly (i.c.v.) via osmotic minipumps for 3 days. A direct LC injection of glutamate (1 or 10 nmol/5 microl) or naloxone (an opioid receptor antagonist, 24 nmol/5 microl) induced withdrawal signs in morphine- or butorphanol-dependent animals. However, these agents failed to precipitate any withdrawal signs in saline-treated control animals. On the other hand, the expression of withdrawal signs precipitated by the administration of glutamate or naloxone in opioid-dependent animals was completely blocked by concomitant infusion with 1 or 10 nmol/microl/h of an inhibitor of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase and protein kinase C, H-7 [1-(5-isoquinolinesulfonyl)-2-methylpiperazine]. In animals that had been infused with opioids in the same manner, i.c.v. injection of naloxone (48 nmol/5 microl) precipitated withdrawal signs and increased extracellular fluid levels of glutamate in the LC of morphine- or butorphanol-dependent rats measured by in vivo microdialysis method. However, concomitant infusion with H-7 inhibited the increases of glutamate levels in the LC. These results strongly suggest that an expeditious release of glutamate in the LC region plays an important role in the expression of physical dependence on opioids. Furthermore, the action on glutamate release might be increased by the enhancement of cAMP-dependent protein kinase and/or protein kinase C activity.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1997

Glutamate in opioid dependence.

The present review will concentrate on a discussion of recent investigations which implicate a critical linkage of three facets of the central nervous system mediation of opioid dependence, as evidenced by expression of acutely-precipitated withdrawal events. These are the kappa-opioid receptor subtype, the glutamatergic neuronal system and a specific brain locus, the locus coeruleus. The impetus for this line of investigation derives from a recognition that opioid analgesics, such as butorphanol (Stadol), exhibit a markedly different profile of activity at opioid receptors than does morphine yet have abuse liability and cause dependence readily. Emphasis will be placed on demonstration of a rodent model in which butorphanol administration induces dependence through a unique (in comparison with morphine) activation of the kappa-opioid receptor. The use of in vivo microdialysis techniques clearly identifies, in this model, that acutely-precipitated withdrawal from dependence on butorphanol results in focal increases in extracellular levels of glutamate within the locus coeruleus, and that the withdrawal syndrome can be mimicked by intracerebroventricular administration of exogenous glutamate, acting through the N-methyl-D-aspartate glutamate receptor subtype. The data confirm the participation of glutamate as a general phenomenon in opioid dependence, identify the locus coeruleus as a primary site for glutamatergic mediation of dependence, and suggest novel aspects to the neuropharmacology of opioid dependence with respect to the role of the kappa-opioid receptor.

Analgesics, Opioid↗

PubMed1996

Mu- and delta-opioid receptor antagonists precipitate similar withdrawal phenomena in butorphanol and morphine dependence.

The relative involvement of mu- and delta-opioid receptors in the mediation of butorphanol-, as compared to morphine-, dependence was examined with the use of highly selective antagonists at mu- and delta-opioid receptors. Extracellular fluid levels of glutamate (Glu) and aspartate (Asp) were measured within the pontine locus coeruleus following precipitation of withdrawal from dependence on either butorphanol or morphine in conscious Sprague-Dawley rats. Dependence was induced by intracerebroventricular (i.c.v.) infusion of butorphanol (26 nmol/mu l/h), morphine (26 nmol/mu l/h) or saline vehicle (1 mu l/h) for 3 days by means of an osmotic minipump. Microdialysis probes (2 mm tip) were inserted into the locus coeruleus 24 h before precipitation of withdrawal by i.c.v. injection of either the mu-opioid receptor antagonist, D-Pen-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP; 48 nmol/5 mu l or 48 nmol/5 mu l), or the delta-opioid receptor antagonist, naltrindole (17-cyclopropy;methyl-6,7-dehydro-4,5-epoxy-3, 14-dihydroxy-6,7,2'3'-indolmorphinan hydrochloride; 48 nmol/5 mu l or 100 nmol/5 mu l). Baseline levels of Glu ranged from 9.59 + or - 1.27 to 12.84 + or - 3.01 mu M in the various treatment groups. Levels of Asp were similar. Precipitation of withdrawal by CTOP elicited significant increases of Glu and Asp in both morphine- and butorphanol-dependent rats. Maximal increases in Glu of 425% and 258% above baseline levels were elicited in the first 15 min microdialysis sample following i.c.v. injection of CTOP in morphine- and butorphanol-dependent rats, respectively. Behavioral signs of withdrawal were greater in morphine than butorphanol-dependent groups. The i.c.v. treatment with naltrindole elicited increases in Glu and Asp that were similar, although less marked, than those precipitated by CTOP treatment. Administration of naltrindole produced equivalent signs of withdrawal in both morphine- and butorphanol-dependent rats. Withdrawal from dependence on both morphine and butorphanol is characterized by elevations in coerulear levels of excitatory amino acids. Responses elicited following the use of selective mu- and delta-opioid receptor antagonists to precipitate withdrawal suggest that the role played by these receptors in mediation of the signs and symptoms of withdrawal do not differ greatly between butorphanol- and morphine-dependent rats.

Animals↗

PubMed1995

Increased locus coeruleus glutamate levels are associated with naloxone-precipitated withdrawal from butorphanol in the rat.

Extracellular fluid levels of glutamate were measured in the locus coeruleus during butorphanol (a mixed agonist at mu-, delta-, and kappa-opioid receptors) withdrawal by using microdialysis in conscious butorphanol-dependent Sprague-Dawley rats. Guide cannulae were implanted chronically and rats were given intracerebroventricular (i.c.v.) infusions of butorphanol (26 nmol/1 microliter/hr) or saline (1 microliter/hr) for 3 days. Microdialysis probes (2 mm tip) were inserted into the locus coeruleus 24 hr before precipitation of withdrawal by i.c.v. injection of naloxone (48 nmol/5 microliters). A separate series of rats was rendered dependent by peripheral injection of butorphanol (20 mg/kg, s.c., b.i.d.) for 5 days and naloxone (5 mg/kg, i.p.) was given to precipitate withdrawal. Single injections of butorphanol (26 nmol/5 microliters, i.c.v.) had no effect on the extracellular fluid levels of glutamate, compared to rats injected with vehicle. Behavioral evidence of withdrawal was detected following naloxone challenge in butorphanol-dependent rats (both i.c.v. and s.c. models), but not in non-dependent, vehicle-treated rats. Significant increases (P < 0.05) in levels of glutamate were noted after naloxone-precipitated withdrawal only in the butorphanol group. The glutamate levels in the locus coeruleus increased from 8.37 +/- 2.01 before, to 21.93 +/- 4.58 microM in the first 15 min sample following i.c.v. injections of 48 nmol/5 microliters naloxone and from 10.84 +/- 1.74 before, to 26.01 +/- 6.19 microM in the 15-30 min sample following i.p. injections of 5 mg/kg naloxone in the butorphanol-dependent rats, respectively. These results provide direct evidence to support the role of excitatory amino acids within the locus coeruleus in butorphanol withdrawal.

Animals↗

PubMed1994

Tolerance development to butorphanol: comparison with morphine.

In order to evaluate and to compare the time course, dose response, and the degree of tolerance development to butorphanol and morphine, rats were continuously intracerebroventricularly (ICV) infused with saline vehicle (1 microliter/h), butorphanol (6.5, 13, 26, and 52 nmol/microliters/h), or morphine (1.6, 6.5, and 26 nmol/microliters/h) through osmotic minipumps for 1 to 3 days. The tail-flick responses were determined pre-, during, and postinfusion. Tolerance to morphine developed faster than that to butorphanol. The antinociceptive response to the ICV challenge dose (6 h after the termination of drug infusion) of butorphanol or morphine was decreased significantly and there was a negative correlation between the dose of the drug infused and the observed antinociceptive response. In terms of butorphanol and morphine tolerance, a parallel rightward shift in the dose-response curve was produced with the degree of shift proportional to the log of the infusion dose. In tail-flick tests, the shifts of the dose-response curves for butorphanol and morphine in tolerant animals were 11.8- and 46.3-fold, respectively. However, in the acetic acid writhing test, the shifts of the dose-response curves for butorphanol and morphine in tolerant animals were 11.3- and 11.7-fold, respectively. These results suggest that there is a greater degree of tolerance to morphine than there is to butorphanol, but the degree of butorphanol tolerance is still substantial. In addition, two pain assays (tail flick vs. writhing) yielded different estimations of tolerance in a comparison of morphine and butorphanol.

Animals↗

PubMed1994

Crosstolerance between butorphanol and morphine in rats.

To investigate the antinociceptive effects of morphine and U-50,488 after continuous administration with butorphanol, rats were intracerebroventricularly (ICV) infused with butorphanol (26 nmol/microliters/h) through osmotic minipumps for 3 days. Six hours after termination of infusion, the rats were challenged with different doses of morphine or U-50,488. Antinociceptive effects, as assessed by tail-flick and acetic acid writing tests, were measured 15 min after challenge. Development of crosstolerance to morphine was evident in butorphanol-infused animals. The study also revealed that crosstolerance to butorphanol developed in continuously ICV morphine-infused animals. Continuous ICV infusion with butorphanol produced a marked rightward shift of the antinociceptive dose-response curve resulting from U-50,488 challenge. These results showed that there is an antinociceptive crosstolerance between butorphanol and morphine, and crosstolerance to U-50,488 developed in continuously butorphanol-infused animals. The present data suggested that chronic ICV treatment with high doses of butorphanol can lead to desensitization of the antinociceptive systems mediated through the central kappa as well as mu receptors in rats.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

PubMed1994

[Hereditary persistence of alpha-fetoprotein].

A proband with persistently elevated AFP levels ranging between 21-129 ng/ml with median of 90 ng/ml has been found and observed for 1 year. Family studies have revealed that his father had had persistent AFP elevation for 4 years, ranging from 46 to 198.2 ng/ml, with median level of 93 ng/ml. His brother also has elevated AFP level. However, his mother, paternal uncle and paternal aunt have normal AFP level. Clinical examinations and laboratory tests have shown that AFP elevations are not associated with primary hepatocellular carcinoma, hepatitis, or other malignancies. We believe that such AFP persistency is of hereditary nature. To our knowledge, this is the first family of hereditary AFP persistence reported in China and the fourth one reported in the world literature.

Adult↗

PubMed1994

[Rational surgical approaches to the treatment of small primary liver cancer, and the prevention of postoperative recurrence].

From Sep. 1985 to Dec. 1990, surgical treatment was performed in 27 patients with small primary liver cancer (SPLC, < or = 5cm in diameter). Of them, segmentectomy was done in 23 cases and radical local resection in 4 cases with recurrence rate of 66.77% (18/27). Non recurrent lesions were located in the incisal margin. In this group re-resection rate was 55.6% (10/18). (1) Early detection and treatment of recurrent lesions remain a mainstay of prolonging survival. (2) Serum Alpha-fetoprotein (AFP), ultrasonography and X-ray chest film were basic follow-up methods for subclinical recurrence of SPLC. For re-operation cases, digital subtract angiography (DSA) are useful in identifying subclinical lesions. (3) For recurrent liver cancer local hepatectomy was a reasonable approach. (4) For SPLC, radical segmentectomy or radical local resection with a safe margin of 1 to 2cm was the authors' choice.

Carcinoma, Hepatocellular↗

PubMed1992

Evaluation of combined assays of serum ferritin, alpha-1-antitrypsin and alpha-fetoprotein in liver cancer.

Serum ferritin (SF), alpha-1-antitrypsin (AAT) and alpha-fetoprotein (AFP) were examined preoperatively in 66 patients with intrahepatic space-occupied lesions revealed by B-real time ultrasonography. Elevated SF levels (> 300 micrograms/L in males and > 180 micrograms/L in females), AAT levels (4.2 g/L), and AFP levels (> 20 micrograms/L) were shown in 84%, 71% and 66% respectively of 55 patients with liver cancer. Combined analysis indicates that if all the three tests are negative, liver cancer can be essentially excluded; and positive AFP can rule out hepatic hemangioma. So combined assays of SF, AAT and AFP are valuable in the diagnosis and differential diagnosis of liver cancer.

Adolescent↗

PubMed1991

Primary ovarian pregnancy. Report of fifteen cases.

From June 1973 through November 1988, fifteen cases of ovarian pregnancy were admitted to the Shanghai First People's Hospital. All these cases met the four criteria for the diagnosis as listed by Spiegelberg. The incidence of ovarian pregnancy as compared to those of normal and ectopic pregnancy are 1:3 179 and 1:28.1, respectively, which are higher than foreign data reported. Ovarian pregnancy is quite similar to tubal pregnancy in clinical manifestations. Etiological analysis does not reveal any close relationship with inflammation of the female genital tract. However, application of IUD increases the risk of ovarian pregnancy. The principle of management is wedge resection of the diseased ovary.

Adult↗

PubMed1989

[Short-term curative effects of daoyin-tuna qigong therapy in 103 cases of chronic atrophic gastritis].

UNLABELLED: Daoyin-Tuna Qigong therapy was applied to 103 cases with chronic atrophic gastritis (CAG). The average duration of disease was 7.8 years. Daoyin-Tuna Qigong exercises were done 4 times a day, 1 hour each time. 79 days made a course and no drug was given. 31 cases were checked with gastroscopy and biopsy, 30 cases with electrogastrogram and 34 cases with immunity detection before and after treatment course. RESULTS: In clinical symptoms, the therapy appeared markedly effective in 72 cases (69.9%). The effective cases were 28 (27.2%). The total effective rate was 97.1%. The body weight of 95 cases (92.2%) increased by 2.4 +/- 1.3 kg on the average at the end of the treatment course, and the capacity for eating was increased by 110 +/- 70 g a day in 99 cases (96.1%). In gastroscopy and pathology examination, the rates of marked effectiveness were 35.5% and 48.4%, the effective 29.0% and 38.7%, the total effective 64.5% and 87.1% respectively. Electrogastrogram check: the frequency and amplitude of the electrogastrogram increased markedly (P less than 0.05) in comparison with the pre-therapy. Immunology examination: E-rosette was 51.3 +/- 8.4% before treatment and 55.3 +/- 7.7% after treatment (P less than 0.05). It is suggested that Daoyin-Tuna Qigong therapy would be a better and new treatment for CAG.

Adolescent↗

PubMed1987