Pharmacokinetic and Pharmacological Profiles of Free and Liposomal Recombinant Human Erythropoietin After Intravenous and Subcutaneous Administrations in Rats

Purpose. Recombinant human erythropoietin (Epo) is used frequently through intravenous (i.v.) and subcutaneous (s.c.) administration for the clinical treatment of the last stage of renal anemia. We encapsulated Epo in liposomes to develop an alternative administration route. The purpose of our study was to evaluate the pharmacokinetics and the pharmacological effects of liposomal Epo in comparison with the Epo after i.v. and s.c. administration to rats. Methods. Epo was encapsulated in liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and soybean-derived sterol mixture (SS) prepared by the reversed-phase evaporation vesicle method. After filtration through a 0.1 m polycarbonate membrane, liposomes were gel filtered (Epo/liposomes). Results. Epo/liposomes showed higher pharmacological activity than Epo/liposomes before gel filtration after i.v. administration to rats. Non-encapsulated Epo lost its activity, whereas encapsulated Epo in liposomes retained it. The pharmacological effects of Epo/liposomes were greater than those of Epo after i.v. administration. Epo/liposomes afforded 3–9 times higher AUC, lower clearance and lower steady-state volume of distribution than Epo after both i.v. and s.c. administrations. Epo/liposomes had an improved pharmacokinetic profile compared with Epo. S.c. administration of Epo/liposomes at 7 h may penetrate primarily (40% of dose) through the blood as a liposome and partly (7% of dose) in lymph. Conclusions. Epo/liposomes may reduce the frequency of injections required for a certain reticulocyte effect in comparison to Epo. The lower clearance of Epo/liposomes may increase the plasma concentrations of Epo, which increases the efficacy.     

Analysis of C-myc messenger-RNA expression in primary breast carcinomas with clinical follow-up

The level of c-myc messenger RNA was measured in 105 primary breast carcinoma samples and matched normal breast tissue from the same patients. Only tumors showing a greater than 2-fold increase in c-myc levels were considered to be overexpressed. Overexpression of c-myc mRNA was identified in 27.6% of tumor samples analysed and was significantly correlated with mitotic grade (p=0.05) and intense lymphocytic infiltrate (p=0.026) but not with other clinical and pathological variables such as size, necrosis, lymph node involvement, estrogen or progesterone receptor status, menopausal status, age or staging of the patients and increased risk of relapse or overall survival. Approximately 25% of the tumors contained overexpression of c-erbB-2 mRNA and simultaneous overexpression of the two oncogenes was seen in only five samples. Disease-free survival was significantly shorter in these patients (p=0.02) and this reduction remained significant after adjustment for nodal status. However, simultaneous overexpression of c-myc and c-erbB-2 did not improve significantly the prediction of risk of death.     

Effect of non-depolarizing muscle relaxants on autonomic nervous system activity--assessment by heart rate variability analysis

We investigated the effect of d-tubocurarine (d-Tc), pancuronium (PAN), vecuronium (VEC), and rocuronium (ROC) on the autonomic nervous system in cats by measuring changes in the invasive mean arterial pressure (MAP), heart rate (HR), and heart rate variability following four administrations of each drug at 2.ED95. Heart rate variability analysis was used to assess the effects of the drugs on sympathetic and parasympathetic nervous system function using low-frequency (0.04-0.22 Hz) component (LF) and high-frequency (0.22-0.60 Hz) component (HF). Comparisons of the HR, MAP, LF, HF, and LF/HF ratio before and after drug administration were made for each drug. The administration of d-Tc caused a significant decrease in MAP and a significant increase in HR accompanied by increase in LF, HF, and LF/HF ratio. The increases in the LF, HF and LF/HF ratio appeared to be related to the mean abrupt enhancement of sympathetic and parasympathetic nervous system function caused by changes in circulatory dynamics. PAN caused a significant increase in HR, and a significant decrease in the HF, which we thought were related to suppression of cardiac parasympathetic function. Neither VEC nor ROC produced a significant change in any of the parameters and were considered to have no significant effect on the autonomic nervous system.     

Finger bougie method compared with pyloroplasty in the gastric replacement of the esophagus

To elucidate the necessity of pyloroplasty for the gastric tube through the posterior mediastinum in esophageal surgery, gastric emptying and duodenogastric reflux (DGR) were evaluated in 16 cases undergoing an anterior pylorectomy (group P) and in 16 cases treated by the finger bougie method (group F). First, the obstruction and reflux symptoms were examined based on a patient questionnaire using a brief scoring system. The median value of the symptom score showed the patients in P to have more symptoms than those in F; however, the difference was not significant (8.0 vs 6.0). Secondly, the swallowed Tc O₄ ⁻ (85 MBq) was counted using a gamma camera at three sites on the sternal bone in the upright position based on a gastric transit scintigram. Both the descending time of the RI peak and the clearance rates were similar between the two groups. Thirdly, intragastric 24-h pH monitoring was carried out. Antimony pH sensors were anchored 5 and 15 cm below the esophagogastrostomy. We could not find any difference between the two groups in both the % time pH>4 and %time pH>7. These findings thus revealed no big difference between groups P and F. The finger bougie method to drain the vagotomized posterior mediastinal stomach was found to achieve results similar to conventional pyloroplasty, while it was also simpler and safer.     

Recurrent benign chondroblastoma at the distal end of the radius

We report a 13-year-old boy with a rapidly recurring benign chondroblastoma in the epiphysis of the distal end of the radius.     

Distribution of mouse interferon-β in normal and brain tumour-bearing mice

Summary The distribution of¹²⁵I-labelled recombinant mouse interferon- (rMuIFN-) in normal and glioma (203 glioma) bearing mice was studied by radioassay and macro-autoradiography at 15 and 30 min after a single intravenous injection. The level of rMuIFN- in the spleen was about 20-fold higher than in serum. Concentrations higher than the serum level was detected in the lung, liver and kidney. The concentration of rMuIFN- in the brain was 8% of the serum level and the concentration in the glioma 30 min after administration was about 10-fold higher than in normal mouse brain. Macro-autoradiographic study demonstrated a wide distribution range and selective uptake in glioma tissue. Furthermore, we found that mouse gliomas were sensitive to mouse IFN-. Our findings demonstrate that in the mouse glioma model, intravenously administered interferon reaches the tumour.     

Cell biological basis for combination radiotherapy using heavy-ion beams and high-energy X-rays.

We investigated the biological effect of combining carbon-beam and X-ray in vitro. The results showed that when we employed Gray equivalent as the indication of therapeutic dose, the effects could be explained with simple additive way in the treatment plan. This fact provides important information about the combined therapy of carbon-beam and X-ray.