Biomedical subjects

Q Liao

Publications and source records attributed to Q Liao.

At least 55 records · Page 3Linked to original sources

PubMed1998

A practical synthesis of 3-substituted delta 3,5(6)-steroids as new potential 5 alpha-reductase inhibitor.

A new and practical synthetic approach to 3-substituted delta 3,5(6)-Steroids, as potential 5 alpha-reductase inhibitor, is described. The key step involves Pd-catalyzed coupling reaction of steroid 3-enol 5H-3-oxo-octafluoropentanosulfonates. 3-Phenylacetylenyl substituted delta 3,5(6)-steroid 3g and 3-phosphate substituted delta 3,5(6)-steroid 3f in our synthesized compounds exhibited high 5 alpha-reductase inhibitory activity in vitro assay.

5-alpha Reductase Inhibitors↗

PubMed1998

Function of adult pig hearts after 2 and 12 hours of cold cardioplegic preservation.

BACKGROUND: Most cardioplegic solutions have been developed using the classic Langendorf heart perfusion model, which only allows a short experimental follow-up. Our aim was to investigate hearts after prolonged storage by using a physiologic model including prolonged perfusion with normal, fresh blood. METHODS: Sixteen hearts from 60-kg pigs were preserved with dextran-enriched (dextran-40, 35 g/L) St. Thomas' solution for 2 or 12 hours after which they were continuously reperfused for 12 hours with normal blood, supplied by a support pig. A flexible balloon, fixed to an artificial valve apparatus connected to a circuit system, was inserted in the left ventricle for obtaining measurements of hemodynamic performance. RESULTS: During the first 3 to 4 hours of reperfusion there was no significant difference in left ventricular developed pressure, cardiac output, minute work output, or oxygen consumption between the two groups. After this time left ventricular developed pressure (p < 0.001), cardiac output (p < 0.01), minute work output (p < 0.01), and oxygen consumption were significantly lower in the 12-hour group. Coronary flow was higher (p < 0.01) and coronary vascular resistance lower (p < 0.01) during the first 5 to 6 hours of reperfusion in the 12-hour group. After 12 hours of reperfusion coronary vascular resistance was significantly higher (p < 0.01) in the 12-hour group. CONCLUSIONS: High-degree and long-lasting coronary hyperemia at the beginning of reperfusion can be a sign of unsatisfactory preservation of the heart. This investigation shows the importance of reperfusion with normal blood and a long follow-up period after postischemic reperfusion when studying the effect of cardioplegic solutions.

Animals↗

PubMed1998

Penetration kinetics of 5-fluorouracil into pancreatic fluid in post-pancreatoduodenectomy patients.

Our aim was to investigate the pharmacokinetic behavior of 5-fluorouracil (5-FU) in pancreatic fluid and to evaluate its penetration characteristics in post-pancreatoduodenectomy patients. After completing the external drainage of the pancreatic duct during pancreatoduodenectomy surgery, eight patients were administered 1.0 g 5-FU i.v. by a 5 min infusion after the eighth day post-surgery on average. Blood and pancreatic fluid were collected, and the 5-FU concentrations were determined by HPLC assay. Their pharmacokinetic parameters were obtained by PCNONLIN and statistical analysis was performed. The Cmax was 20.03 +/- 18.25 mg/l in pancreatic fluid with a Tmax of 15.6 +/- 9.5 min following i.v. administration and 49.69 +/- 20.75 mg/l in plasma. 5-FU in plasma and pancreatic fluid were all in conformity with a non-linear model with a K(m) of 1098.08 +/- 1426.57 and 11.08 +/- 6.38 mg/l, respectively. The concentrations in pancreatic fluid were similar to that observed in plasma with an average penetration index up to 1.01 +/- 0.49. It is suggested therefore that 5-FU is capable of penetrating from blood into the pancreas as evidenced by the observed pancreatic concentrations.

Body Fluids↗

PubMed1998

Pharmacokinetics of 5-fluorouracil and its penetration into pancreatic juice in dogs.

AIM: To study the pharmacokinetic behavior of 5-fluorouracil (5-FU) in pancreatic juice in dogs and its correlation with 5-FU in plasma, and to evaluate its penetration characteristics. METHODS: After placing a pancreatico-drainage tube, 8 dogs were injected 5-FU 250 mg i.v. Blood and pancreatic samples were collected and the 5-FU concentrations were determined by HPLC. The pharmacokinetic parameters were obtained with statistical analysis. RESULTS: The mean slopes of the terminal phase (K10) in plasma and pancreatic juice were 9.4 h-1 and 10.2 h-1, respectively (P > 0.05). The pharmacokinetic behaviors of 5-FU in plasma and pancreatic juice fitted a nonlinear model. Its penetration index was 3.39 +/- 2.84. The penetration of 5-FU from blood to pancreatic juice was relatively rapid, demonstrating a consistently higher concentration in pancreatic juice than in plasma. CONCLUSIONS: The elimination phase of 5-FU in plasma was similar to that in pancreatic juice, indicating that they were in the same kinetic compartment.

Animals↗

PubMed1998

[Gene diagnosis of 10 Chinese families with adult polycystic kidney disease from Guangxi region].

OBJECTIVE: To study presymptomatic gene diagnosis in adult polycystic kidney disease (APKD). METHODS: Linkage analysis and haplotype characterization were carried out in 10 unrelated Chinese APKD families from Guangxi region, including 97 individuals and 29 affected members. Members of these families were ultrasonographically examined. Linkage to PKD1 was investigated in all families with four microsatellite markers(SM7, CW2, AC2.5, and KG8). These flanking markers were amplified by PCR. RESULTS: The families were fully informative for gene diagnosis and no evidence of genetic heterogeneity was found. DNA analysis predicted 7 asymptomatic individuals(by 28 years old) as being affected, although they all presented negative ultrasonographs. CONCLUSION: Linkage analysis is still an important way in APKD presymptomatic gene diagnosis.

Adult↗

PubMed1997

Modeling neural activity using the generalized inverse Gaussian distribution.

Spike trains from neurons are often used to make inferences about the underlying processes that generate the spikes. Random walks or diffusions are commonly used to model these processes; in such models, a spike corresponds to the first passage of the diffusion to a boundary, or firing threshold. An important first step in such a study is to fit families of densities to the trains' interspike interval histograms; the estimated parameters, and the families' goodness of fit can then provide information about the process leading to the spikes. In this paper, we propose the generalized inverse Gaussian family because its members arise as first passage time distributions of certain diffusions to a constant boundary. We provide some theoretical support for the use of these diffusions in neural firing models. We compare this family with the lognormal family, using spike trains from retinal ganglion cells of goldfish, and simulations from an integrate-and-fire and a dynamical model for generating spikes. We show that the generalized inverse Gaussian family is closer to the true model in all these cases.

Action Potentials↗

PubMed1997

[The effect of blood-pancreatic juice barrier on antitumor drugs excretion].

Chemotherapy is one of important adjuvant therapies for patients with pancreatic adenocarcinoma, but the mechamism 5-FU and MMC distributed over the pancreas is not known at home and abroad. Based on determining the ratio of the concentration of several kinds of antibioticsin plasma and pancreatic juice, we used fourteen dogs to study the distribution and the relationship of agents in plasma and pancreatic juice after giving 5-FU and MMC intravenously. At the same time, we observed some patients who received Whipple's operation. The results showed that 5-FU and MMC in plasma can penetrate the pancreatic tissue and cross the blood-pancreatic juice barrier (BPJB). Both agents suitable for the adjuvant chemotherapy of pancreatic adenocarcinoma.

Ampulla of Vater↗

PubMed1997

[An analysis of acute leukemia cells TfR expression in children].

There are a lot of transferrin receptors on the acute leukemia cells. We used the method of "Receptor Radioligand Assay" to determine the numbers of TfR binding sites on leukemia cells from 20 child patients with acute lymphocyte leukemia (ALL) and 9 with acute myeloid leukemia (AML). The results showed the numbers of TfR binding sites of AML cells were higher than those of ALL cells, and the numbers of complete remission group were lower than those of dead or relapse group. This indicated there might be a relationship between the TfR expression and the prognosis.

Adolescent↗

PubMed1997

[Expression of iron responsive element binding protein mRNA and analysis of aconitase activity in iron deficiency anemia rats].

OBJECTIVE: To explore the regulatory mechanism of iron responsive element binding protein (IRE-BP) in iron metabolism. METHODS: The expression level of IRE-BP mRNA and the aconitase activity were studied in iron deficiency anemia (IDA) rat model. RESULTS: No distinct change of IRE-BP mRNA expression was observed in iron deficiency rats. The aconitase activity of liver cytoplasmic protein was much lower in iron deficiency rats than that in controls and treatment of liver cytoplasmic protein with FeSO4 resulted in a strong stimulation of the enzymatic activity. CONCLUSION: Both posttranslational and posttranscriptional regulation of IRE-BP may take part in iron metabolism balance.

Aconitate Hydratase↗

PubMed1997

[Expression of ferritin receptor on placental microvillous membrane and its role in maternal-fetal iron transport].

OBJECTIVE: In order to investigate the expression of ferritin receptor (FnR) on human placental microvillous membrane in mid-pregnancy and its implication. METHODS: Radioligand binding assay was used, with horse spleen 125I-apo-ferritin as radioligand. RESULTS: The FnR expression in normal placental microvillous membrane in mid-pregnancy was (9.63 +/- 4.72) x 10(12) sites/mg pro, similar to that in normal placental of term delivery,and the dissociation constants (Kd) between them had also no significant difference: Competitive binding assay indicated that the receptor bound basic ferritin with higher affinity than acidic one. CONCLUSIONS: The expression of FnR in mid-pregnancy almost come to mature level; The FnR on placenta might be involved in maternal-fetal iron transport, transfering iron from mother to fetal.

Apoferritins↗

PubMed1997

[Localization of ferritin in placental villous tissue and its role in the maternal-fetal iron transport].

OBJECTIVE: To investigate the localization and quantity of ferritin in placental villous tissue and its implications. METHODS: The localization of ferritin in placental villous tissue at different gestation period was assayed by immunocytochemistry. The quantity of ferritin in placental villous tissue was determined with radioimmunoassay. RESULTS: Ferritin was localized in all layers of the trophoblast, especially in the surface of the syncytiotrophoblast and basal membrane. The quantity of ferritin in placental villous tissue was increased with gestation progress and decreased in pregnant women with IDA. CONCLUSIONS: Ferritin may be the important carrier of transplacental iron transport, and its receptor plays a crucial role in the course. The placental iron transport varied with gestation progress and iron nutritional status of the mother.

Anemia, Iron-Deficiency↗

PubMed1997

[Internal fixation with U-shaped pin in the treatment of fracture-dislocation of the cervical spine].

Twenty cases with fracture-dislocation of the cervical spine were treated by U-shaped pin fixation. The U-shaped pin made of Steiman pin was used to hold sublaminar fixation of two segments above and below the vertebra of fracture. When atlas or axis was injured, a pair of small holes were drilled on the occipitale. The closed end of the U-Shaped pin was wired through the holes. Early postoperative ambulation was allowed without external fixation. 18 cases were followed up for 8-35 months. 5 cases of six patients with neurologic deficits recovered completely. The remaining one improved, no failure or loosening of the U-Shaped pin or wires was observed. Sound union of the bone grafts was obtained in all the patients. The results suggest that the operative procedure is simple, with sound fixation and satisfactory reduction and union of the fractures.

Adolescent↗

PubMed1997

[Development of three dimensional bone-connecting plate and its clinical application].

Biomechanical assessment showed that the three dimensional plate developed by the authors which had stereo-rigidity in the fixation of long bone fractures was superior to compressive plate and flanged plate in terms of anti-compressive and anti-torsional strength. The anti-bending strength was superior to the flanged plate but inferior to compressive plate. The comprehensive nature of the three dimensional plate remained superior. Clinical application in 112 cases with 85 of them being followed-up for 8-44 months showed that bone union occurred in 45-98 days. The average was 82 days. In 65 cases of them the plates had been removed. No delayed-union or non-union occurred. Preliminary experience showed that the three dimensional plate was a new design for the treatment of long bone fractures. It can be applied to various types of long bone fractures especially the severe comminuted fractures owing to its requirement of proper fixation.

Adolescent↗

PubMed1995

[A 3-year follow-up study of 50 children with acute lymphoblastic leukemia].

Fifty children with acute lymphoblastic leukemia were followed up for an average period of 3 3/12 years. The results showed that 19 (38%) cases were given up after diagnosis. Eight patients only received treatment irregularly for 1 year; among them, 2 discontinued therapy by themselves for 2-3 years and survived free of events, and 6 were lost, Twenty-three received treatment regularly; among them, 3 died of infection, 11 were in continuously complete remission and 9 experienced relapse. The total disease-free survival rate for mean 3 3/12 years is 42% (13/31), exclusive of the 19 given up cases. Statistical analysis indicates a higher relapse rate in those cases with lower initial glucocorticoid receptors (GCR) of peripheral blood lymphocytes.

Child↗

PubMed1995

Diagnosis and surgical treatment of bronchogenic cysts.

Between 1974 and 1993, 22 patients with bronchogenic cysts were operated on in our hospital; there were 14 men and 8 women, ranging in age from 11 to 62 years. The cyst locations were mediastinal in 13 (59.1%) and intrapulmonary in 9 (40.9%). There were symptoms (chest pain and recurrent bronchiolitis) in 20 patients (91%). The preoperative complications included infection in the lung and in the cyst and dysphagia due to esophageal compression. Chest pain was the main symptom in mediastinal cyst and recurrent infection of lung in intrapulmonary cyst. Plain chest radiograms showed that a round shadow, occasional air-fluid levels, and peripheral calcification may be found in cysts. An operation is the best treatment for cysts. All cysts were completely excised. No postoperative complications, late complications, or recurrence developed in our patients.

Adolescent↗

PubMed1995

[The sandwich enzyme-linked immunoabsorbent assay of serum transferrin receptor by using monoclonal and polyclonal antibodies].

The human placenta transferrin receptor was purified in the form of transferrin-transferrin receptor complex (Tf-TfR), and a monospecific polyclonal antibody against TfR was developed by a Tf-coupled Sepharose 4B affinity chromatography to remove the anti-Tf components in the antiserum. A sandwich enzyme-linked immunoabsorbent assay (ELISA) was established for measuring serum transferrin receptor (sTfR) by using monoclonal antibody OKT9 and monospecific polyclonal antibody. This method is simple, specific and sensitive and has a good accuracy. The measurement of sTfR showed that the level of normal children was 4.54 +/- 1.08 mg/L. There were increased levels of sTfR in patients with severe iron deficiency anemia and those with hemolytic anemia (13.92 +/- 4.45 mg/L and 9.94 +/- 3.22 mg/L, respectively). In patients with aplastic anemia, the level was decreased (2.06 +/- 0.82 mg/L). These results indicate that the sTfR measurement has a differential significance for diagnoses of various anemia.

Anemia, Aplastic↗

PubMed1994

[Surgical treatment and diagnosis of adult bronchogenic cysts].

Between 1974 and 1993, 22 adults with bronchogenic cysts were operated in our hospital: 14 men and 8 women, ranging from 11 to 62 years old. The location was mediastinal in 13 (59.1%) and intrapulmonary in 9 (40.9%). Cysts were symptomatic (chest pain and recurrent bronchiolitis) in 20 patients (91%). The perioperative complications include infection in lungs and in the cysts and dysphagia due to esophageal compression. Chest pain was the main symptom in mediastinal cyst and recurrent infection of lungs in intrapulmonary cysts. Plain chest radiographs showed round shadows. Occasional air-fluid levels, peripheral calcification may be found. Operation is the best method for treating cysts. All cysts were completely excised. No perioperative, late complication or recurrence developed in our patients. Operation was recommended in most instances to confirm the diagnosis, to relieve symptoms, and to prevent complications.

Adolescent↗

PubMed1994

[Malignant lymphomas in childhood in Sichuan province--a clinicopathological analysis of 304 cases].

A clinicopathological study of 304 cases of malignant lymphomas (ML) in children in Sichuan province is reported. One hundred and sixty of them were Hodgkin's disease (HD). The ratio between males and females was 5.7 to 1. The disease was more prevalent in children aged from 5 to 9. Cervical lymph nodes were more easily involved. Extra-nodal HD wasn't found in these cases. When subtypes of HD were concerned 62.5% of cases belonged to mixed-cellularity HD. The prognosis of HD was better than that of non-Hodgkin's lymphoma (NHL). The remaining 144 cases were NHL. The ratio between males and females was 3.4 to 1. The disease was more prevalent in children aged from 4 to 14. Eighty four percent of NHL primarily originated from superficial lymph nodes and the other 16.0% of NHL was of extranodal involvement. Seventy two point nine percent of cases in this group was of high grade malignancy. Among them the lymphoblastic type of NHL occupied 44.5%. On the other hand, the follicular type of NHL was rare (0.7%). The specialities of malignant lymphomas in childhood in China are also discussed in the present report.

Adolescent↗