SolPredictor: Predicting Solubility with Residual Gated Graph Neural Network

Computational methods play a pivotal role in the pursuit of efficient drug discovery, enabling the rapid assessment of compound properties before costly and time-consuming laboratory experiments. With the advent of technology and large data availability, machine and deep learning methods have proven efficient in predicting molecular solubility. High-precision in silico solubility prediction has revolutionized drug development by enhancing formulation design, guiding lead optimization, and predicting pharmacokinetic parameters. These benefits result in considerable cost and time savings, resulting in a more efficient and shortened drug development process. The proposed SolPredictor is designed with the aim of developing a computational model for solubility prediction. The model is based on residual graph neural network convolution (RGNN). The RGNNs were designed to capture long-range dependencies in graph-structured data. Residual connections enable information to be utilized over various layers, allowing the model to capture and preserve essential features and patterns scattered throughout the network. The two largest datasets available to date are compiled, and the model uses a simplified molecular-input line-entry system (SMILES) representation. SolPredictor uses the ten-fold split cross-validation Pearson correlation coefficient R2 0.79±0.02 and root mean square error (RMSE) 1.03±0.04. The proposed model was evaluated using five independent datasets. Error analysis, hyperparameter optimization analysis, and model explainability were used to determine the molecular features that were most valuable for prediction.

Suaeda glauca Attenuates Liver Fibrosis in Mice by Inhibiting TGFβ1-Smad2/3 Signaling in Hepatic Stellate Cells

Chronic liver injury due to various hepatotoxic stimuli commonly leads to fibrosis, which is a crucial factor contributing to liver disease-related mortality. Despite the potential benefits of Suaeda glauca (S. glauca) as a natural product, its biological and therapeutic effects are barely known. This study investigated the effects of S. glauca extract (SGE), obtained from a smart farming system utilizing LED lamps, on the activation of hepatic stellate cells (HSCs) and the development of liver fibrosis. C57BL/6 mice received oral administration of either vehicle or SGE (30 or 100 mg/kg) during CCl4 treatment for 6 weeks. The supplementation of SGE significantly reduced liver fibrosis induced by CCl4 in mice as evidenced by histological changes and a decrease in collagen accumulation. SGE treatment also led to a reduction in markers of HSC activation and inflammation as well as an improvement in blood biochemical parameters. Furthermore, SGE administration diminished fibrotic responses following acute liver injury. Mechanistically, SGE treatment prevented HSC activation and inhibited the phosphorylation and nuclear translocation of Smad2/3, which are induced by transforming growth factor (TGF)-β1 in HSCs. Our findings indicate that SGE exhibits anti-fibrotic effects by inhibiting TGFβ1-Smad2/3 signaling in HSCs.

Transthoracic fine-needle aspiration biopsy of the lungs using a C-arm cone-beam CT system: diagnostic accuracy and post-procedural complications

OBJECTIVE

The purpose of our study was to evaluate the diagnostic accuracy of transthoracic fine-needle aspiration biopsy (TFNAB) using a C-arm cone-beam CT (CBCT) system and to assess risk factors for immediate post-procedural complications in patients with lung lesions.

METHODS

From October 2007 to April 2009, 94 TFNAB procedures using a C-arm system were studied in 91 patients with pulmonary lesions a chest CT scans. We retrospectively reviewed the patients' radiological and histopathological findings. We evaluated the lesion size, lesion abutted to pleura and presence or absence of emphysema along the needle path, lesion depth, visibility of target lesion and patient's position. Pneumothorax and pulmonary haemorrhage were assessed after TFNAB. Overall diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were analysed.

RESULTS

In 94 TFNAB procedures, 58 lesions were malignant and 36 were benign. The sensitivity, specificity, PPV, NPV and overall diagnostic accuracy rate of TFNAB were 93.1%, 100%, 100%, 90% and 97.9%, respectively. Pneumothorax was developed in 24 procedures. None of the parameters showed significant impact on the frequency of the pneumothorax. Overall haemorrhage occurred in 43 procedures. The incidence of overall haemorrhage was higher in patients with smaller lesions, longer pleural distance and pleural abutted lesions (p<0.05). Differences in visibility at projection radiographs were statistically significant between patients with or without perilesional haemorrhage (p<0.05).

CONCLUSION

Transthoracic fine-needle aspiration biopsy using a C-arm CBCT system is feasible for imaging guidance of lung lesion and early detection of the procedural-related complications.

A pre- and postoperative bacteriological study of chronic suppurative otitis media

BACKGROUND

Although many bacteriological studies on preoperative otorrhea in patients with chronic suppurative otitis media (CSOM) have been performed, there are few studies on postoperative otorrhea. In this study, we analyzed the pathogenic microorganisms, changes in the bacterial species before and after surgery, and the antibiotic sensitivity on preoperative and postoperative cultures.

METHODS

This was a retrospective study of 87 postoperative otorrhea patients who were part of a sample of 1,754 patients with CSOM who underwent tympanomastoidectomy; preoperative and postoperative otorrhea samples were obtained from January 2002 to April 2009. We analyzed patients with postoperative otorrhea divided into two groups: those with early onset (<3 months after surgery, n = 45) and those with late onset (>3 months after surgery, n = 42) otorrhea.

RESULTS

Four species of organisms, methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Pseudomonas, and coagulase-negative Staphylococcus (CNS), showed higher prevalence than others on both the preoperative and postoperative cultures. When we compared the early and late onset otorrhea groups, we found that 'no growth' was significantly higher in the early onset group (n = 19 vs. n = 5), whereas MSSA was significantly higher in the late onset group (n = 1 vs. n = 12). Of the 67 patients with positive preoperative cultures, 15 (22.4%) had the same bacteria after surgery, 34 (50.8%) had other bacteria, 2 (3.0%) had fungi, and 16 (23.8%) showed no growth on postoperative bacteriological testing. MSSA (9%) and MRSA (16.7%) were rarely recultured after surgery, whereas Pseudomonas was recultured frequently (61.5%).

CONCLUSION

Unlike MSSA and MRSA, ciprofloxacin-resistant P. aeruginosa (CRP) occasionally causes early onset postoperative otorrhea due to the lack of highly potent antibiotics against this species. The success rate of infection control by surgery and antibiotics was low for CRP.

Preparation of doxorubicin-containing chitosan microspheres for transcatheter arterial chemoembolization of hepatocellular carcinoma

A new form of doxorubicin hydrochloride (DRH)-containing chitosan microspheres (CMs) was prepared by employing an expanding-loading-shrinking (E-L-S) process. One hundred mg of pre-formed CMs were soaked in absolute ethanol and then placed in reduced pressure (the expanding process). Ten mg of DRH (2 mg ml(-1)) were added into the expanded CMs (the loading process). Next the microspheres were freeze-dried (the shrinking process). As a result of this E-L-S process, 10% (w/w) DRH-containing CMs (DRH-CM) were made. During 7 days, 22.6% of the DRH was observed to be released on the in vitro drug release study. In addition, these new DRH-CMs could be used for transcatheter arterial chemoembolization (TACE) procedure in VX2 hepatic tumour models of rabbit and the anti-tumour effects of DRH-CMs were investigated. On the post-CT scan 7 days after the TACE, total infarctions of the VX2 tumour were observed in 5 rabbits among the 6 total rabbits.

Expression and characterization of a recombinant Cry1Ac crystal protein with enhanced green fluorescent protein in acrystalliferous Bacillus thuringiensis

AIMS

To investigate fusion expression between Bacillus thuringiensis crystal protein and a foreign protein, the expression of a fusion protein comprised of Cry1Ac, and enhanced green fluorescent protein (EGFP) in B. thuringiensis Cry(-)B strain was examined.

METHODS AND RESULTS

The N-terminal fusion expression of EGFP in Cry1Ac was attempted under the control of the native cry1Ac promoter. The EGFP gene was cloned into pProMu and named pProMu-EGFP. The transformant, ProMu-EGFP/CB produced parasporal inclusions that were of bipyramidal-shaped crystals in size ranging from 200 to 300 nm. The fusion protein was approximately 150 kDa and identified by the immunoblot analysis using a Cry1Ac antibody and also a GFP antibody. The LC(50) of the ProMu-EGFP/CB was twofold higher when compared with that by the ProAc/CB. However, the crystal protein produced by the ProMu-EGFP/CB was effective on Plutella xylostella larvae.

CONCLUSIONS

The ProMu-EGFP/CB produced bipyramidal shaped and insecticidal crystals comprising fusion proteins.

SIGNIFICANCE AND IMPACT OF THE STUDY

Through the N-terminal fusion expression of EGFP and Cry1Ac, expression and crystallization between the B. thuringiensis crystal protein and a foreign protein were validated.

Pharmacokinetics, stability, and blood partition of DA-8159, a new phosphodiesterase V inhibitor

The pharmacokinetics of DA-8159, a new phosphodiesterase V inhibitor, after 1 min intravenous, 30 mg/kg, and oral, 30 mg/kg, administration of the drug to rats, the stability of DA-8159 in various pH solutions ranging from 1 to 13, and human and rat plasma and urine, and the blood partition of DA-8159 between plasma and blood cells of rabbit were evaluated. After intravenous administration, DA-8159 was eliminated fast with the mean total body clearance of 126 ml/min/kg, and was almost completely metabolized in rats; 5.98% of intravenous dose of DA-8159 were excreted unchanged in 24-hr urine. The extent of absolute oral bioavailibility of DA-8159 was approximately 25%. The apparent volume of distribution at steady state was considerably large, 15048 ml/kg, suggesting that DA-8159 has a good affinity to rat tissues. DA-8159 was relatively stable in various pH solutions, and human and rat plasma and urine for up to 48 h incubation in a water-bath shaker kept at 37 degrees C and at a rate of 50 oscillations per min. DA-8159 reached equilibrium fast (within 30 sec mixing manually) between plasma and blood cells of rabbit blood and the plasma-to-blood cell concentration ratios were independent of initial blood concentrations of DA-8159, 1, 5, and 10 microg/ml, when the rabbit whole blood was incubated for up to 120 min; the ratios were in the range of 0.662-0.812. There was no in vitro 'blood storage effect' in the plasma concentration of DA-8159.

An experimental model of ischemia in rabbit hindlimb

This study was performed to establish an experimental model of ischemia for the investigation of new treatment modality of limb-threatening ischemia. We produced ischemia in the hindlimbs of 8 New Zealand white rabbits. Under general anesthesia, the left femoral artery was exposed, freed, and excised from distal external iliac artery to proximal popliteal and saphenous arteries. And then both hindlimbs were serially examined to assess the ischemia according to the time table until postoperative 6 weeks. We assessed clinical observation, blood pressure, radioisotopic perfusion scan, and angiography. Clinical ischemic changes of the operated feet were observed in 63%. The blood pressure of left calves was measurable on postoperative day 3 (p<0.05, vs preoperative day 2) and then gradually increased to reach a plateau in postoperative week 6. Radioisotopic arterial perfusion showed similar profiles as in blood pressure. Angiography of ischemic hindlimbs demonstrated a few collateral vessels arising from the internal iliac artery with the reconstitution of the posterior tibial artery in postoperative week 2. In postoperative week 6, collaterals remained the same in number. However, these became dilated and tortuous and showed reconstitution in distal hindleg. In conclusion, this is a reproducible, measurable, and economical animal model of hind limb ischemia.

Hepatocellular carcinoma: correlation between vascular endothelial growth factor level and degree of enhancement by multiphase contrast-enhanced computed tomography

RATIONALE AND OBJECTIVES

To determine whether vascular endothelial growth factor (VEGF) is a histopathological factor influencing contrast enhancement of hepatocellular carcinoma (HCC) on computed tomography (CT).

METHODS

Twenty-two nodular HCCs underwent multiphase helical CT and surgery. Tumor size, histological grading of differentiation, and type of hepatitis were evaluated. Tumor attenuation was graded as hyperattenuated, isoattenuated, and hypoattenuated. Immunohistochemical staining with anti-VEGF antibody was performed and scored as weak, intermediate, or strong. Spearman's rank correlation test was used.

RESULTS

Tumors ranged from 1.0 to 12.0 cm (mean 5.1 cm). The degree of enhancement during the hepatic arterial phase was significantly correlated with VEGF expression. Size was negatively correlated with VEGF expression and the degree of enhancement, but histological grade and type of hepatitis were not correlated with VEGF expression, tumor size, or degree of enhancement.

CONCLUSIONS

In HCC, VEGF expression is correlated with the degree of contrast enhancement during arterial-phase CT.

Subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, after single and 4-week repeated oral administration in dogs

The subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, were evaluated after single (at the 1st day) and 4-week (at the 28th day) oral administration of the drug, in doses of 0 (to serve as a control), 12.5, 50 and 200 mg/kg/day, to male and female dogs (n=3 for male and female dogs for each dose). DA-8159 had an effect on the immune-related organs (or tissues), circulatory systems, liver, adrenal glands, ovaries and pancreas. The toxic dose was 200 mg/kg and no observed adverse effect level was less than 50 mg/kg for male and female dogs. There were no significant gender differences in the pharmacokinetic parameters of DA-8159 for each dose after both single and 4-week oral administration. The pharmacokinetic parameters of DA-8159 were dose-independent after single oral administration; the time to reach a peak plasma concentration (T(max)) and the dose-normalized area under the plasma concentration-time curve from time zero to 24 h in plasma (AUC(0-24 h)) were not significantly different among three doses. However, accumulation of DA-8159 after 4-week oral administration was considerable at toxic dose, 200 mg/kg/day. For example, after 4-week administration, the dose-normalized AUC(0-24 h) value at 200 mg/kg/day (4.71 and 15.3 microg h/ml) was significantly greater than that at 12.5 mg/kg/day. After 4-week oral administration, the dose-normalized C(max) and AUC(0-24 h) at 200 mg/kg/day were significantly higher and greater, respectively, than those after a single oral administration.

Correlation of VEGF with contrast enhancement on dual-phase dynamic helical CT in liver tumors: preliminary study

The purpose of this preliminary study is to elucidate that vascular endothelial growth factor (VEGF) influences contrast enhancement of hepatic tumors on computed tomography (CT). Fourteen patients with hepatic tumors (11 hepatocellular carcinomas; 3 metastatic cancers) underwent a dual-phase dynamic helical CT or computed tomographic hepatic arteriography. The attenuation of each mass was determined as hyperattenuation, isoattenuation or hypoattenuation with respect to the adjacent nontumorous parenchyma. Gun-needle biopsy was done for each tumor, and paraffin sections were immunostained with anti- VEGF antibody by the avidin-biotin-peroxidase complex method. The pathologic grade was made by intensity (1 +, 2+, 3+) and area (+/-, 1 +, 2+). The tumor ranged 2.0-14.0 cm in size (mean, 5.8 cm). In arterial phase, the intensity was not correlated with the degree of enhancement (p=0.086). However, the correlation between the attenuation value of hepatic arterial phase and the area of positive tumor cells was statistically significant (p=0.002). VEGF may be the factor that enhances the hepatic mass with water-soluble iodinated contrast agent in CT.

Factors influencing the protein binding of a new phosphodiesterase V inhibitor, DA-8159, using an equilibrium dialysis technique

Various factors influencing the protein binding of DA-8159 to 4% human serum albumin (HSA) were evaluated using an equilibrium dialysis technique at an initial DA-8159 concentration of 5 microg/mL. It took approximately 8 h incubation to reach an equilibrium between 4% HSA and an isotonic phosphate buffer of pH 7.4 containing 3% of dextran ('the buffer') using a Spectra/Por 2 membrane (mol. wt. cut-off: 12,000--14,000) in a water bath shaker kept at 37 degrees C and at a rate of 50 oscillations per min. The extent of binding was dependent on DA-8159 concentrations, HSA concentrations, incubation temperature, buffer pH, and alpha-1-acid glycoprotein (AAG) concentrations. The binding of DA-8159 in heparinized human plasma (93.9%) was significantly higher than in rats (81.4%), rabbits (80.4%), and dogs (82.2%), and this could be due to differences in AAG concentrations in plasma.

Tuberculous aneurysm of the abdominal aorta: endovascular repair using stent grafts in two cases

Tuberculous aneurysm of the aorta is exceedingly rare. To date, the standard therapy for mycotic aneurysm of the abdominal aorta has been surgery involving in-situ graft placement or extra-anatomic bypass surgery followed by effective anti-tuberculous medication. Only recently has the use of a stent graft in the treatment of tuberculous aortic aneurysm been described in the literature. We report two cases in which a tuberculous aneurysm of the abdominal aorta was successfully repaired using endovascular stent grafts. One case involved is a 42-year-old woman with a large suprarenal abdominal aortic aneurysm and a right psoas abscess, and the other, a 41-year-old man in whom an abdominal aortic aneurysm ruptured during surgical drainage of a psoas abscess.

Percutaneously implantable catheter-port system for chemotherapeutic infusion through the hepatic artery

OBJECTIVE

The goal of this study was to determine the feasibility and outcomes of percutaneously implantable catheter-port system placement in the hepatic artery for the purpose of intraarterial chemotherapeutic infusion.

CONCLUSION

Percutaneously implantable catheter-port system placement is safe and technically feasible for use in the hepatic artery. The implantation procedure is less invasive than surgical implantation of similar port systems.

Recanalization of obstructed Tenckhoff peritoneal dialysis catheter: wire/stylet manipulation combined with endoluminal electrocauterization

We report the results of fluoroscopically guided wire/stylet manipulation combined with endoluminal electrocauterization in seven patients with obstructed Tenckhoff peritoneal dialysis catheters. In preparation for clinical application, electrocauterization was performed using a stone basket to recanalize surgically removed Tenckhoff catheters obstructed with omental fat ingrowing through the side holes. All ingrowing omental fat was removed easily by electrocauterization with the rotating movement of a stone basket. The technique was then applied in vivo in seven cases with ingrowing omental fat and malpositioned catheter; six (86%) were successfully recanalized. Among those six cases with initial success, four maintained good catheter function with durable patency (mean 261.3 days). No significant complication was noted.

Phase I clinical trial: pharmacokinetics of a novel anthracycline, DA-125 and metabolites. Single dose study

Single dose of DA-125, 20 (n = 3), 40 (n = 3), 60 (n = 3), 80 (n = 6), or 100 (n = 6) mg/m2 body surface area, was administered intravenously in 5 min to 21 patients with various types of cancer as phase I clinical trial. The main side-effects of DA-125 were nausea, vomiting, leukopenia (especially neutropenia), and thrombocytopenia. Among those, hematological side-effects increased with increased doses of DA-125. No patient developed side-effects equal to or higher than grade III up to DA-125 dose of 60 mg/m2. However, at DA-125 dose of 80 mg/m2, 1 out of 3 patients developed grade III leukopenia and grade IV neutropenia. Therefore, 3 additional patients participated taking the dose of 80 mg/m2; no patient developed side-effects equal to or higher than grade III. Hence, DA-125 dose increased to 100 mg/m2. At DA-125 dose of 100 mg/m2, 2 out of 3 patients developed side-effects equal to or higher than grade III and, therefore, 3 additional patients participated taking this dose. Among the 3 additional patients, 1 patient developed both grade III leukopenia and neutropenia. Therefore, further accrual was stopped at this dose (100 mg/m2). The maximally tolerated dose (MTD) of DA-125 was determined to be 100 mg/m2, and the dose-limiting factor for DA-125 was bone marrow suppression. DA-125 dose of 80 mg/m2, 80% of MTD of DA-125, was recommended as the dose for phase II clinical trial. Cardiotoxicity was not observed in any of the 21 patients according to the ECG and RVG. Neither fever, stomatitis, diarrhea, and renal and nervous system toxicity, nor abnormality in blood coagulation was observed in any of the patients, and death or life-threatening side-effects due to DA-125 were also not observed. Antitumor effects of DA-125 were evaluated from the 21 patients; 6 progressive disease, 14 stable disease, and 1 partial response. Pharmacokinetic parameters of M1, such as AUC, t1/2, CL, VSS, and MRT, seemed to be independent of i.v. doses of DA- 125, 20-100 mg/m2 and less than 0.75% of M1 were excreted in 96 h urine when expressed in terms of DA-125 i.v. dose. M2 was the main metabolite of DA-125 among M1-M4 excreted in urine; 10.1 approximately 22.3% of M2 was excreted in 96 h urine when expressed in terms of DA-125 i.v. dose. Bile was collected via the T-tube in 1 additional patient at the dose of 100 mg/m2. Biliary excretion of M1 and M2 was negligible; less than 0.320 and 4.76% of M1 and M2, respectively, were excreted in 96 h bile when expressed in terms of DA-125 i.v. dose.

Pharmacokinetics of a new carbapenem, DA-1131, after intravenous administration to rats with uranyl nitrate-induced acute renal failure

Because the physiological changes that occur in patients with acute renal failure could alter the pharmacokinetics of the drugs used to treat the disease, the pharmacokinetics of DA-1131, a new carbapenem antibiotic, were investigated after 1-min intravenous administration of the drug (50 mg/kg of body weight) to control rats and rats with uranyl nitrate-induced acute renal failure (U-ARF rats). The impaired kidney function was observed in U-ARF rats on the basis of physiological parameters observed by microscopy of the kidney and obtained by chemical analysis of the plasma. After a 1-min intravenous infusion of DA-1131, the concentrations in plasma and the total area under the plasma concentration-time curve from time zero to time infinity increased significantly in U-ARF rats compared with those in control rats (13,000 versus 4,400 microg x min/ml). This was due to the significantly slower total body clearance (CL) of DA-1131 (3.84 versus 11.4 ml/min/kg) from U-ARF rats than from control rats. The significantly slower CL of DA-1131 from U-ARF rats was due to both significantly slower renal clearance (0.000635 versus 4.95 ml/min/kg because of a significant decrease in the 8-h urinary excretion of unchanged DA-1131 [1.54 versus 43.8% of the intravenous dose] due to impaired kidney function, as proved by the significant decrease in creatinine clearance [0.0159 versus 4.29 ml/min/kg]) and significantly slower nonrenal clearance (3.80 versus 6.34 ml/min/kg because of a significant decrease in the metabolism of DA-1131 in the kidney) in U-ARF rats. The amounts of DA-1131 recovered from all tissues studied (except the kidneys) were significantly higher for U-ARF rats than for control rats; however, the ratios of the amount in tissue to the concentration in plasma (except those for the kidney, small intestine, and spleen) were not significantly different between the two groups of rats, indicating that the affinity of DA-1131 for rat tissues was not changed considerably in U-ARF rats.

Pharmacokinetics of a non-narcotic analgesic, DA-5018, in rats

The pharmacokinetics of a non-narcotic analgesic, DA-5018, were compared after single intravenous (i.v.), subcutaneous (s.c.), and oral administrations, and after multiple (seven consecutive days) s.c. administration to rats. After i.v. administration of DA-5018, 1, 2, and 5 mg kg-1, the pharmacokinetic parameters of DA-5018 were independent of the dose ranges studied. After oral administration of DA-5018, absorption of the drug from gastrointestinal (GI) tract was fast, but the extent of absolute bioavailability (F) was low; the values were 23.2, 23.0, and 27.3% for 2, 5, and 10 mg kg-1, respectively. After single s.c. administration of DA-5018, absorption of the drug from the injected site was fast and the extent of absorption was fairly good; the F values were 74.5 and 71.8% for 2 and 5 mg kg-1, respectively. The lower F values after oral administration of DA-5018 to rats could be due to degradation of the drug in rat GI tract and/or considerable first-pass effect. After i.v., oral, and s.c. administration of DA-5018, the drug had a strong affinity to the rat tissues studied as reflected in the greater-than-unity tissue to plasma ratio. After i.v., oral, and s.c. administration of the drug, the biliary and urinary excretion of unchanged DA-5018 were negligible. There was no significant difference in the pharmacokinetics or tissue distribution of DA-5018 between single and multiple s.c. administration of the drug, 5 mg kg-1, to rats, indicating that there could be no tissue accumulation of the drug after multiple s.c. administration of the drug to rats.

Determination of a new non-narcotic analgesic, DA-5018, in plasma, urine and bile by high-performance liquid chromatography

A high-performance liquid chromatographic method was developed for the determination of a new non-narcotic analgesic, DA-5018 (I), in rat plasma, urine and bile samples, using propranolol for plasma samples and protriptyline for urine and bile samples as internal standards. The method involved extraction followed by injection of 100 microliters of the aqueous layer onto a C18 reversed-phase column. The mobile phases were 5 mM methanesulfonic acid with 10 mM NaH2PO4 (pH 2.5)-acetonitrile, 70:30 (v/v) for plasma samples and 75:25 (v/v) for urine and bile samples. The flow-rates were 1.0 ml/min for plasma samples and 1.2 ml/min for urine and bile samples. The column effluent was monitored by a fluorescence detector with an excitation wavelength of 270 nm and an emission wavelength of 330 nm. The retention time for I was 4.8 min in plasma samples and 10.0 min in urine and bile samples. The detection limits for I in rat plasma, urine and bile were 20, 100 and 100 ng/ml, respectively. There was no interference from endogenous substances.

Pharmacokinetics of DA-125, a new anthracycline, after intravenous administration to spontaneously hypertensive rats and DOCA-salt-induced hypertensive rats

Pharmacokinetic parameters-including tissue distribution, biliary excretion, and urinary excretion of M1-M4-were compared after an intravenous administration of DA-125 (a new anthracycline derivative; 20 mg/kg body weight) to male spontaneously hypersensitive rats (SHRs) at 16 weeks (an animal model for human primary hypertension) and at 6 weeks (corresponding to the early phase of the development of hypertension, at which time blood pressure remains within the normotensive range) of age and their age-matched control Kyoto-Wistar rats, and male deoxycorticosterone acetate-salt-induced Sprague-Dawley rats (DOCA-salt rats, an animal model for human secondary hypertension) at 16 weeks of age and their age-matched control Sprague-Dawley rats. Mean plasma concentrations of both M2 and M4, and the resultant area under the plasma concentration-time curve from time 0 to last measured time [AUCT; M2 (68.9 vs. 29.3 micrograms-min/ml) and M4 (53.4 vs. 33.4 micrograms-min/ml)], increased significantly in SHRs at 16 weeks of age, compared with their control rats. Similar results were also obtained from DOCA-salt rats at 16 weeks of age, compared with their control rats. However, values were not significantly different between SHRs at 6 weeks of age and their control rats. Previous data indicated that the significant increase in plasma concentrations and the resultant AUCT values of both M2 and M4 in SHRs at 16 weeks of age were due to the hypertension state itself, and not to any hereditary characteristics of the SHRs. The significantly increased plasma concentrations and the resultant AUCT values of M2 in both SHRs and DOCA-salt rats at 16 weeks of age were due to the significantly decreased biliary excretion of M2 and possibly to the increased amount of aldo-keto reductase in the liver. However, the increase in the two aforementioned pharmacokinetic parameters in the case of M4 were possibly due solely to the increased amount of aldo-keto reductase in the liver.

Pharmacokinetics of four metabolites of DA-125, a new anthracycline antineoplastic agent after single and multiple intravenous administration to rats

The tissue distribution, and biliary and urinary excretion of four metabolites (M1-M4) of a new anthracycline antineoplastic agent (DA-125) were compared after single and multiple (7 consecutive days) intravenous (i.v.) administration to rats. The mean pharmacokinetic parameters of M1, such as area under the plasma concentration-time curve (AUC: 56.4 micrograms/ml vs. 69.0 micrograms min/ml), terminal half-life (t1/2: 3.51 h vs. 3.01 h), total body clearance (Cl: 70.9 ml/min/kg vs. 58.0 ml/min/kg), renal clearance (ClR: 0.193 ml/min/kg vs. 0.336 ml/min/kg) and nonrenal clearance (ClNR: 70.7 ml/min/kg vs. 57.7 ml/min/kg); of M2, such as plasma AUC (39.4 micrograms min/ml vs. 41.9 micrograms min/ ml), t1/2 (6.15 h vs. 7.34 h) and ClR (10.5 ml/min/ kg vs. 13.8 ml/min/kg); and of M4, such as plasma AUC (4.82 micrograms min/ml vs. 6.54 micrograms min/ml) and t1/2 (3.33 h vs 4.02 h), were comparable between single and multiple administrations of DA-125. M3 was detected in plasma for up to 1-5 min, and M3 and M4 were below the detection limit in 24-h urine after both single and multiple administrations of DA-125. M2 was the main metabolite of DA-125 excreted (among M1-M4) in 24-h urine after both single and multiple administrations of DA-125; approximately 12.3% and 20.1% (P < 0.01) of i.v. dosage (expressed in terms of DA-125) was excreted as M2 after single and multiple administrations of DA-125, respectively. Corresponding values for M1 were 0.326% and 0.694% (P < 0.05). The mean levels of M1 (229 micrograms vs. 175 micrograms) and M2 (1330 micrograms vs. 1120 micrograms) excreted in 24-h bile after single and multiple administrations of DA-125 were not significantly different; the percentages of i.v. dosage excreted in 24-h bile as M1 (expressed in terms of DA-125) were 4.83% and 3.58% after single and multiple administrations, respectively. The corresponding values for M2 were 27.8% and 22.5%. M3 and M4 were below the detection limit in 24-h bile after both single and multiple administrations of DA-125. Mean AUAts (area under the amount-time curves from time zero to last measurement time t) (or AUCts-area under the plasma concentration-time curves from time zero until the last measurement time t) of M1-M4 in each tissue after single and multiple administrations of DA-125 were also comparable except in the bone marrow and thymus. The data suggest that 7 consecutive days of i.v. administration of DA-125 (4 mg/kg) to rats does not lead to considerable accumulation of M1-M4 in the tissues, except in the bone marrow and thymus.

Comparison of pharmacokinetics of M1, M2, M3, and M4 after intravenous administration of DA-125 or ME2303 to mice and rats. New adriamycin analogues containing fluorine

The pharmacokinetics of M1, M2, M3 and/or M4 were compared after intravenous (i.v.) administration of DA-125 and/or ME2303 to mice (25 mg kg(-1)) and rats (5, 10, 20, 30, and 40 mg kg(-1)). The mean plasma concentrations of M1 were detected up to 8 h after i.v. administration of both DA-125 and ME2303 to mice, and were significantly higher for DA-125 than ME2303; this resulted in a considerably greater AUC (303 against 148 micrograms min mL(-1)) and a considerably slower CL of M1 (69.3 against 136 mL min-1 kg(-1)) after i.v. administration of DA-125. The MRT (371 against 189 min) and CLNR of M1 (68.7 against 136 mL min-1 kg(-1)) were considerably greater and slower, respectively, after i.v. administration of DA-125. The mean plasma concentrations of M2 were detected up to 8 and 4 h after i.v. administration of DA-125 and ME2303, respectively, to mice and were significantly higher for DA-125 than ME2303, resulting in a considerably greater AUC of M2 (148 against 27.1 micrograms min mL(-1)) after i.v. administration of DA-125. The mean plasma concentrations of M3, being the lowest among M1-M4, were detected only up to 15 min after i.v. administration of both DA-125 and ME2303 to mice, and were comparable after i.v. administration of DA-125 and ME2303 to mice. The mean plasma concentrations of M4 were detected up to 8 h after i.v. administration of both DA-125 and ME2303 to mice, and were higher after i.v. administration of DA-125 than ME2303, resulting in a considerably greater AUC of M4 (197 against 61.9 micrograms min mL(-1)) after i.v. administration of DA-125. Similar results on M1 and M2 were also obtained from rats: the mean plasma concentrations of both M1 and M2 were significantly higher after i.v. administration of DA-125, 10 mg kg(-1), than after ME2303. The plasma concentrations of M1, M2, and M4, and hence their AUCs, were significantly higher after i.v. administration of DA-125, 5, 10, 20, 30, and 40 mg kg(-1), to rats than after ME2303: the mean plasma concentrations of M2, approximately 0.1-0.4 micrograms mL(-1), were maintained from 30 min to 8-10 h after i.v. administration of DA-125, 20, 30, and 40 mg kg(-1), to rats; the plasma concentrations of M3 were the lowest among M1-M4 at all DA-125 doses; and those of M1 and M4 were maintained for a long period of time. However, after i.v. administration of M2, 5 mg kg(-1), to rats, the mean plasma concentrations of M2 were detected up to 60 min with a mean terminal half-life of only 38.8 min, and the concentrations of M3 were negligible. After i.v. administration of M3, 5 mg kg(-1), to rats, the mean plasma concentrations of M3 were detected up to 15 min; the plasma concentrations of M4, reaching their peak at 5 min, decayed more slowly and were higher than those of M3. The AUC of M4 after i.v. administration of M3, 5 mg kg(-1), was comparable to that after i.v. administration of M4, 5 mg kg(-1), to rats, suggesting that M4 is formed fast and almost completely from M3. M1 was not detected in plasma after i.v. administration of either M2 or M3 to rats. After i.v. administration of M4, 5 mg kg(-1), to rats, the mean plasma concentrations of M4 decayed fast with a mean terminal half-life of 43.9 min and neither M2 nor M3 were detected in plasma. The following disposition mechanisms for M1, M2, M3, and M4 after i.v. administration of DA-125 to rats could be obtained from the above data; (i) the maintenance of plasma concentrations of M2 for a longer period of time after i.v. administration of DA-125 than those after i.v. administration of M2 could be due to the continuous formation of M2 from M1; (ii) the lowest plasma concentrations of M3 among M1-M4 after i.v. administration of DA-125 could be due to the fast and almost complete information of M4 from M3 as soon as M3 is formed from M1, and not due to the fast renal excretion of unchanged M3; (iii) M4 was exclusively and continuously formed from M3 and the formation of M4 from M2 was negligible; and (i.v.) reversible me

Pharmacokinetics of DA-125, a new anthracycline, after intravenous administration to uranyl nitrate-induced acute renal failure rats or protein-calorie malnutrition rats

The pharmacokinetics of DA-125 were compared after intravenous (i.v.) administration of the drug, 10 mg kg-1, to control male Sprague-Dawley rats (n = 9) and uranyl nitrate-induced acute renal failure (U-ARF, n = 12) rats, or male Sprague-Dawley rats fed on a 23% (control, n = 8) or a 5% (protein-calorie malnutrition, PCM, n = 9) protein diet. After i.v. administration of DA-125, almost 'constant' plasma concentrations of M1, M2, and M4 were maintained from 1-2 h to 8-10 h in all rat groups due to the continuous formation of M2 from M1 and M4 from M3. The plasma concentrations of M3 were the lowest among M1-M4 for all rat groups due to the rapid and almost complete conversion of M3 to M4 and other metabolite(s). The AUCt values of M1 (115 against 82.5 micrograms min mL-1), M2 (33.0 against 23.6 micrograms min mL-1), and M4 (26.3 against 15.1 micrograms min mL-1) were significantly higher in the U-ARF rats than in the control rats. The percentages of i.v. dose excreted in 24 h urine as M1 (under the detection limit against 0.316%), M2 (under the detection limit against 5.58%), and M4 (0.0174 against 0.719%)--expressed in terms of DA-125--were significantly lower in the U-ARF rats than in the control rats, and this could be due to the decreased kidney function in the U-ARF rats. However, the percentages of i.v. dose recovered from the GI tract at 24 h as M1 (0.0532% against under the detection limit), M3 (0.0286% against under the detection limit), and M4 (0.702% against 0.305%)--expressed in terms of DA-125--were significantly greater in the U-ARF rats than in the control rats. All U-ARF rats had ascites, but the concentrations of M1 (0.0320 micrograms mL-1), M2 (0.0265 micrograms mL-1), M3 (under the detection limit), and M4 (0.032 micrograms mL-1) in the ascites from one rat were almost negligible. The plasma concentrations and most of the pharmacokinetic parameters of M1, M2, and M4 were not significantly different between the PCM rats and their control rats.

Stability, blood partition, and protein binding of DA-5018, a new nonnarcotic analgesic

The stability of DA-5018, a capsaicin analog as a new non-narcotic analgesic, in plasma, blood, 4% human serum albumin (HSA), and isotonic Sørensen phosphate buffer at pH 7.4 containing dextran to make 3% ('the buffer'), the blood partition of DA-5018 between plasma and blood cells, and the factors influencing the binding of DA-5018 to 4% HSA using an equilibrium dialysis technique were evaluated. DA-5018 was stable in both rat blood and plasma for up to 4 hr storage at 25 degrees C. However, DA-5018 was unstable in both dog blood and plasma; the disappearance half-lives were 1 and 1.67 hr for dog blood and plasma, respectively, when they were kept at 25 degrees C. DA-5018 seemed to be stable in 'the buffer' for up to 24 hr standing at both 25 degrees C and 37 degrees C, and in 4% HSA at 25 degrees C. However, DA-5018 was unstable in 4% HSA at 37 degrees C. DA-5018 reached equilibrium very fast between blood cells and plasma in rat blood; the mean blood cells to plasma concentration ratio was 1.31 +/- 0.0907. Although both blood and plasma concentrations of DA-5018 were unstable after incubation in dog blood, the blood cells to plasma concentration ratio was independent of incubation time; the mean value was 0.857 +/- 0.0502. Binding of DA-5018 to 4% HSA was dependent on DA-5018 concentration, buffer pH, and incubation temperature. The binding was independent of buffers containing various chloride ion concentrations. The binding of DA-5018 was dependent on alpha-1-acid glycoprotein and HSA concentrations.

Improved transjugular intrahepatic portosystemic shunt patency with PTFE-covered stent-grafts: experimental results in swine

PURPOSE

To evaluate the ability of stent-grafts made with polytetrafluoroethylene (PTFE) graft material to improve transjugular intrahepatic portosystemic shunt (TIPS) patency.

MATERIALS AND METHODS

TIPS were created in 13 swine by using PTFE-covered stent-grafts. Uncovered TIPS were placed in 13 other swine. Twenty-one of 26 animals were followed up with portal venography for 3 months or until the shunt became severely stenotic. Five animals without severe stenosis were sacrificed before 3 months because of illness.

RESULTS

At 4 weeks after TIPS placement, nine of 13 stent-graft TIPS were patent (< 50% diameter narrowing) compared with only one patent stent in 13 uncovered TIPS. Six of 13 stent-graft TIPS remained patent until the animals were sacrificed. In 11 of 12 uncovered TIPS, stenosis was most prominent in the parenchymal tract. In five of seven stent-graft TIPS, stenosis was most prominent in the hepatic vein above the end of the graft material. Bile leaks were discovered in six occluded uncovered TIPS and in two of the stent-graft TIPS.

CONCLUSION

PTFE-covered stent-grafts significantly improved TIPS patency in swine (P < .01). However, stenosis in the hepatic vein led to late shunt malfunction in selected cases.

Pharmacokinetics and antitumour activity of a new anthracycline, DA-125, after intravenous administration to subcutaneously implanted Lewis-lung-carcinoma-bearing mice

The pharmacokinetics and tissue distribution of M1-M4 were compared after intravenous (i.v.) administration of DA-125, 25 mg kg-1, to BDF1 mice (n = 5 at each sampling time) and subcutaneously implanted Lewis-lung-carcinoma-bearing BDF1 mice (n = 10 at each sampling time. The mean plasma concentrations of M1-M4 were not significantly different between the two groups of mice, and hence similar pharmacokinetic parameters for M1-M4 were obtained. The amount of M1 in the lung was significantly greater in the tumour-bearing mice than in the control mice, resulting in a greater AUAt in the tumour-bearing mice (18,600 against 8940 micrograms min g-1), and vice versa in the liver (962 against 3840 micrograms min g-1). However, the corresponding values for other tissues were comparable between the control and tumour-bearing mice. The amount of M1 was greatest in the lung for up to 2 h in the tumour-bearing mice. M2 was the predominant metabolite among M1-M4 excreted in 24 h urine by both groups of mice; 8.36 and 10.7% of the i.v. dose were excreted in 24 h urine as M2--expressed in terms of DA-125--by the control and tumour-bearing mice, respectively. The amount of M1 in the tumour mass reached a mean Cmax of 3.75 micrograms g-1 immediately after i.v. administration of DA-125 to the tumour-bearing mice, then declined very slowly to an amount that remained almost constant for up to 24 h. This suggested that M1 has high affinity for the subcutaneously implanted Lewis lung carcinoma. The antitumour activity, such as the increase in life span (ILS) and tumour growth inhibition (TGI) of DA-125, 6-48 mg kg-1, and adriamycin (ADM), 3-18 mg kg-1, were also compared in subcutaneously implanted Lewis-lung-carcinoma-bearing BDF1 mice after four weekly i.v. administration of the drugs on days 1,8,15, and 22 following tumour implantation. More than three out of six mice survived as tumour-free for longer than 70 d at a DA-125 dose range of 6-24 mg kg-1, but there were no tumour-free mice at any dose of ADM. Assuming ILS values higher than 30% to be effective, DA-125 doses ranging from 6 to 24 mg kg-1 were effective in increasing the life span, which ADM does only within the dose range of 6-12 mg kg-1.

Simultaneous determination of a new anthracycline, DA-125, and its metabolites M1, M2, M3 and M4 in plasma and urine by high-performance liquid chromatography

A high-performance liquid chromatographic method was developed for the simultaneous determination of a new anthracycline, DA-125 (I), and its metabolites (M1, M2, M3, and M4) in rat plasma and urine using fluorescein as an internal standard. Compound I, a prodrug of M1, is a beta-alanine derivative of M1, and only M1 shows antineoplastic activity. The method involved extraction or deproteinization followed by injection of 80-100 microliters of the aqueous layer or supernatant onto a C18 reversed-phase column. The mobile phases were 1% acetic acid-isopropyl alcohol-methanol (70:20:10, v/v) or 5 mM of ion-pairing chromatography reagent (IPC B8)-isopropyl alcohol-methanol (70:20:10, v/v) for the extraction or deproteinization methods, respectively. The flow-rate was 1.5 ml/min for both methods. The column effluent was monitored by a fluorescence detector with excitation wavelength of 488 nm and emission wavelength of 556 nm. The detection limits for M1, M2, M3, and M4 in rat plasma and urine were 50 ng/ml for all compounds using the extraction method, and 100, 50, 50, 50, and 50 ng/ml for I, M1, M2, M3 and M4 in rat plasma respectively, using the deproteinization method. No interferences from endogenous substances, adriamycin or daunorubicin were found.

Factors influencing the protein binding of bumetanide using an equilibrium dialysis technique

Factors that influence the plasma protein binding of bumetanide were evaluated using equilibrium dialysis. It took approximately 12 h of incubation to reach an equilibrium between plasma and isotonic phosphate buffer of pH 7.4 containing 3% dextran using a Spectrapor 2 membrane (mol. wt cut-off = 12,000-14,000) in a water-bath shaker kept at 37 degrees C and at a rate of 50 oscillations per min. Bumetanide was fairly stable in both 4% human serum albumin (HSA) and in the isotonic phosphate buffer of pH 7.4 for up to 24 h. The binding of bumetanide to 4% HSA was constant (87.5 +/- 1.73%) at bumetanide concentrations ranging from 0.1 to 100 micrograms/ml. The extents of binding were 72.0, 83.3, 88.5, 90.2, 91.3 and 91.4% at albumin concentrations of 0.5, 1, 2, 3, 4 and 5 g/100 ml, respectively, and increased with a decrease in incubation temperature; the values bound were 94.6, 90.3 and 89.3% when incubated at 4, 22 and 37 degrees C, respectively. The binding of bumetanide was independent of the buffer composition used, the quantities of AAG (up to 0.32%), heparin (up to 40 units/ml), sodium azide (up to 0.5%) and anticoagulants (EDTA, heparin and citrate). The free fraction of bumetanide in rabbit plasma (2.91%) was significantly higher than in humans (1.98%) or rats (1.85%).