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.

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.

[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.

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.

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.

[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.

[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.

[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.

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.

Diabetes in urban African Americans: functional health literacy of municipal hospital outpatients with diabetes

Functional health literacy was assessed in 63 patients from the diabetes outpatient clinic, 20 from the general medicine clinic, and a total of 48 from two satellite medical clinics. All patients received a demographic questionnaire, visual screening, and the Test of Functional Health Literacy in Adults, an instrument with good validity and internal consistency used to measure the ability to read and understand medical instructions. Functional health literacy was adequate in only 47% of new patients at the diabetes clinic and only 25% of established patients at all sites. There were no significant differences in functional health literacy among established patients across all sites. Overall, patients' mean functional health literacy level was inadequate to marginal. Of the patients with inadequate functional health literacy, 43% denied difficulty in reading. Patient education strategies and materials are needed to address this important barrier to healthcare delivery.

[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.

[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.

[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.

[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.

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.

[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.

[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.

[Preparation of human placenta microvillous membrane and the study of its transferrin receptor]

Human placenta microvillous membrane (PMM) was prepared by differential centrifugation and by sucrose gradient centrifugation, and the transferrin receptor (TfR) was studied using the receptor radioassay with 125I-transferrin as a radioligand. The factors affecting ligand-receptor binding reaction and the characteristics of TfR were also studied. The result showed that there was no significant differences (P > 0.1) in specific binding rates of 125I-transferrin to its receptor between the two membrane preparations, indicating that both of them could be used for TfR analysis, but the method of differential centrifugation was more simple and less time consuming. The study of TfR in sixty cases showed that the TfR binding sites on PMM and Bmax were 3.53 +/- 1.98 x 10(12) sites/mg membrane protein and 6.33 +/- 4.21 x 10(-12) mol/mg membrane protein, respectively. The Kd was 4.95 +/- 3.39 x 10(-9) mol/L, and the highest specific binding was 26% with nonspecific binding less than 3%. The conditions for ligand-receptor binding reaction were optimized when the concentrations of membrane protein and the 125I-transferrin in each test tube were 50 micrograms and 50,000 cpm (specific radioactivity being 2109 kBq/micrograms transferrin) respectively the incubation time was 30 min, and the concentration of polyethylene glycol added for separating B/F was 12% (W/V). transferrin binding to its receptor was characterized by high affinity, high specificity and being saturated.

[Investigation of impairment of neutrophil's phagocytosis and bactericidal function in rats with iron deficiency]

Studies were made to determine the neutrophil's phagocytosis and bactericidal function in three groups of rats (control, iron deficiency, and iron supplement). Results showed that there were significant differences in values of chemiluminescence (CL) among three groups. The values of peak CL and five minutes integrated CL were markedly decreased in neutrophils of iron-deficient rats, accounting for only 41% and 32% of the control's values respectively. These suggested that the activity of NADPH oxidase was decreased, and the function of respiratory burst of neutrophils was impaired. The activity of myeloperoxidase in the iron-deficient neutrophils was also significantly lower than that in the control cells. It constituted only 30% of the control's value, indicating that the bactericidal function of neutrophils was injured. One week after iron administration, the low values of the peak CL, the five minutes integrated CL and the activity of myeloperoxidase all went up apparently, but not reached the normal levels yet. The time the function of neutrophils in iron-deficient rats returned to normal may be related to the process of neutrophil maturation in bone marrow.

[Influence of iron deficiency anemia on development of thymus and spleen and adenosine deaminase activity in rats]

Models of rats with iron deficiency anemia (IDA) were established, and changes in development of the thymus and spleen and adenosine deaminase (ADA) activity in them studied. The size and weight of the thymus in IDA rats were decreased, which suggested that the development of the thymus was lowered; but the size and weight of the spleen in IDA group were increased. ADA activities of the thymus and the spleen in IDA rats were significantly decreased by 32.98% and 25.89%, respectively. One week after iron supplement, the weight of the thymus and spleen in IDS group returned to normal level (P greater than 0.05), and their ADA activity also significantly increased, but ADA activity of the thymus tissue did not return to the normal. The results suggested that the changes in ADA activity of the thymus and spleen tissues were related to iron deficiency. Stepwise regression analysis suggested that there was a negative correlation between ADA activity of the thymus tissue and FEP/Hb ratio.