Biological Distribution after Oral Administration of Radioiodine-Labeled Acetaminophen to Estimate Gastrointestinal Absorption Function via OATPs, OATs, and/or MRPs

We evaluated the whole-body distribution of orally-administered radioiodine-125 labeled acetaminophen (¹²⁵I-AP) to estimate gastrointestinal absorption of anionic drugs. ¹²⁵I-AP was added to human embryonic kidney (HEK)293 and Flp293 cells expressing human organic anion transporting polypeptide (OATP)1B1/3, OATP2B1, organic anion transporter (OAT)1/2/3, or carnitine/organic cation transporter (OCTN)2, with and without bromosulfalein (OATP and multidrug resistance-associated protein (MRP) inhibitor) and probenecid (OAT and MRP inhibitor). The biological distribution in mice was determined by oral administration of ¹²⁵I-AP with and without bromosulfalein and by intravenous administration of ¹²⁵I-AP. The uptake of ¹²⁵I-AP was significantly higher in HEK293/OATP1B1, OATP1B3, OATP2B1, OAT1, and OAT2 cells than that in mock cells. Bromosulfalein and probenecid inhibited OATP- and OAT-mediated uptake, respectively. Moreover, ¹²⁵I-AP was easily excreted in the urine when administered intravenously. The accumulation of ¹²⁵I-AP was significantly lower in the blood and urinary bladder of mice receiving oral administration of both ¹²⁵I-AP and bromosulfalein than those receiving only ¹²⁵I-AP, but significantly higher in the small intestine due to inhibition of OATPs and/or MRPs. This study indicates that whole-body distribution after oral ¹²⁵I-AP administration can be used to estimate gastrointestinal absorption in the small intestine via OATPs, OATs, and/or MRPs by measuring radioactivity in the urinary bladder.

A single high-dose irradiation changes accumulation of methotrexate and gene expression levels of SLC and ABC transporters in cancer cells

Chemoradiotherapy is frequently used to treat cancer. Stereotactic body radiotherapy (SBRT) is a single high-dose radiotherapy used to treat a variety of cancers. The anticancer drug methotrexate (MTX) shows affinity for solute carrier (SLC) and ATP-binding cassette (ABC) transporters. This study investigated relationships between accumulation of methotrexate and gene expression levels of solute carrier and ATP-binding cassette transporters in cancer cells after a single and high-dose X-ray irradiation. Cancer cell lines were selected from lung and cervical cancer cell line that are commonly used for stereotactic body radiotherapy and effective with methotrexate. We examined expression levels of organic anion-transporting polypeptide (OATP)1B1, OATP1B3, OATP1B7, and organic anion transporter (OAT)1 as solute carrier transporters and multidrug resistance-associated protein (MRP)1 and MRP2 as ATP-binding cassette transporters, using real-time polymerase chain reaction and accumulation of ³H-MTX in cancer cells after 10-Gy irradiation, assuming stereotactic body radiotherapy. Cells were divided into three groups: Control without irradiation; 4 h after irradiation; and 24 h after irradiation. In control, gene expression levels of OAT1 in all cells was below the limit of measurement. After irradiation, gene expression levels of OATP1B1/1B3/1B7 showed changes in each cell line. Gene expression levels of MRP1/2 tended to increase after irradiation. Gene expression levels of OATP1B1/1B3/1B7 were much lower than those of MRP1/2. Accumulation of ³H-MTX tended to decrease over time after irradiation. Irradiation of cancer cells thus alters gene expression levels of both solute carrier transporters (OATP1B1/1B3/1B7) and ABC transporters (MRP1/2) and decreases accumulation of ³H-MTX in cancer cells over time due to elevated expression of MRP1/2.

Measurement of Hepatic CYP3A4 and 2D6 Activity Using Radioiodine-Labeled O-Desmethylvenlafaxine

Drug metabolizing enzyme activity is affected by various factors such as drug–drug interactions, and a method to quantify drug metabolizing enzyme activity in real time is needed. In this study, we developed a novel radiopharmaceutical for quantitative imaging to estimate hepatic CYP3A4 and CYP2D6 activity. Iodine-123- and 125-labeled O-desmethylvenlafaxine (123/125I-ODV) was obtained with high labeling and purity, and its metabolism was found to strongly involve CYP3A4 and CYP2D6. SPECT imaging in normal mice showed that the administered 123I-ODV accumulated early in the liver and was excreted into the gallbladder, as evaluated by time activity curves. In its biological distribution, 125I-ODV administered to mice accumulated early in the liver, and only the metabolite of 125I-ODV was quickly excreted into the bile. In CYP3A4- and CYP2D6-inhibited model mice, the accumulation in bile decreased more than in normal mice, indicating inhibition of metabolite production. These results indicated that imaging and quantifying the accumulation of radioactive metabolites in excretory organs will aid in determining the dosages of various drugs metabolized by CYP3A4 and CYP2D6 for individualized medicine. Thus, 123/125I-ODV has the potential to direct, comprehensive detection and measurement of hepatic CYP3A4 and CYP2D6 activity by a simple and less invasive approach.

Indirect SPECT Imaging Evaluation for Possible Nose-to-Brain Drug Delivery Using a Compound with Poor Blood–Brain Barrier Permeability in Mice

Single-photon emission computed tomography (SPECT) imaging using intravenous radioactive ligand administration to indirectly evaluate the time-dependent effect of intranasal drugs with poor blood-brain barrier permeability on brain drug distributions in mice was evaluated. The biodistribution was examined using domperidone, a dopamine D2 receptor ligand, as the model drug, with intranasal administration at 0, 15, or 30 min before intravenous [123I]IBZM administration. In the striatum, [123I]IBZM accumulation was significantly lower after intranasal (IN) domperidone administration than in controls 15 min after intravenous [125I]IBZM administration. [123I]IBZM SPECT was acquired with intravenous (IV) or IN domperidone administration 15 min before [123I]IBZM, and time–activity curves were obtained. In the striatum, [123I]IBZM accumulation was clearly lower in the IN group than in the control and IV groups. Time–activity curves showed no significant difference between the control and IV groups in the striatum, and values were significantly lowest during the first 10 min in the IN group. In the IN group, binding potential and % of receptor occupancy were significantly lower and higher, respectively, compared to the control and IV groups. Thus, brain-migrated domperidone inhibited D2R binding of [123I]IBZM. SPECT imaging is suitable for research to indirectly explore nose-to-brain drug delivery and locus-specific biological distribution.

123I-BMIPP, a Radiopharmaceutical for Myocardial Fatty Acid Metabolism Scintigraphy, Could Be Utilized in Bacterial Infection Imaging

In this study, we evaluated the use of 15-(4-123I-iodophenyl)-3(R,S)-methylpentadecanoic acid (123I-BMIPP) to visualize fatty acid metabolism in bacteria for bacterial infection imaging. We found that 123I-BMIPP, which is used for fatty acid metabolism scintigraphy in Japan, accumulated markedly in Escherichia coli EC-14 similar to 18F-FDG, which has previously been studied for bacterial imaging. To elucidate the underlying mechanism, we evaluated changes in 123I-BMIPP accumulation under low-temperature conditions and in the presence of a CD36 inhibitor. The uptake of 123I-BMIPP by EC-14 was mediated via the CD36-like fatty-acid-transporting membrane protein and accumulated by fatty acid metabolism. In model mice infected with EC-14, the biological distribution and whole-body imaging were assessed using 123I-BMIPP and 18F-FDG. The 123I-BMIPP biodistribution study showed that, 8 h after infection, the ratio of 123I-BMIPP accumulated in infected muscle to that in control muscle was 1.31 at 60 min after 123I-BMIPP injection. In whole-body imaging 1.5 h after 123I-BMIPP administration and 9.5 h after infection, infected muscle exhibited a 1.33-times higher contrast than non-infected muscle. Thus, 123I-BMIPP shows potential for visualizing fatty acid metabolism of bacteria for imaging bacterial infections.

Comparison of L- and D-Amino Acids for Bacterial Imaging in Lung Infection Mouse Model

The effectiveness of L- and D-amino acids for detecting the early stage of infection in bacterial imaging was compared. We evaluated the accumulation of ³H-L-methionine (Met), ³H-D-Met, ³H-L-alanine (Ala), and ³H-D-Ala in E. coli EC-14 and HaCaT cells. Biological distribution was assessed in control and lung-infection-model mice with EC-14 using ³H-L- and D-Met, and ¹⁸F-FDG. A maximum accumulation of ³H-L- and D-Met, and ³H-L- and D-Ala occurred in the growth phase of EC-14 in vitro. The accumulation of ³H-L-Met and L-Ala was greater than that of ³H-D-Met and D-Ala in both EC-14 and HaCaT cells. For all radiotracers, the accumulation was greater in EC-14 than in HaCaT cells at early time points. The accumulation was identified at 5 min after injection in EC-14, whereas the accumulation gradually increased in HaCaT cells over time. There was little difference in biodistribution between ³H-L-and D-Met except in the brain. ³H-L- and D-Met were sensitive for detecting areas of infection after the spread of bacteria throughout the body, whereas ¹⁸F-FDG mainly detected primary infection areas. Therefore, ¹¹C-L- and D-Met, radioisotopes that differ only in terms of ³H labeling, could be superior to ¹⁸F-FDG for detecting bacterial infection in lung-infection-model mice.

Inhibition of the Hepatic Uptake of 99mTc-Tetrofosmin Using an Organic Cation Transporter Blocker

The accumulation of high levels of ^99mTc-tetrofosmin (^99mTc-TF) in the hepatobiliary system can lead to imaging artifacts and interference with diagnosis. The present study investigated the transport mechanisms of ^99mTc-TF and attempted to apply competitive inhibition using a specific inhibitor to reduce ^99mTc-TF hepatic accumulation. In this in vitro study, ^99mTc-TF was incubated in HEK293 cells expressing human organic anion transporting polypeptide 1B1 (OATP1B1), OATP1B3, OATP2B1, organic anion transporter 2 (OAT2), organic cation transporter 1 (OCT1), OCT2, and Na⁺-taurocholate cotransporting polypeptide with or without each specific inhibitor to evaluate the contribution of each transporter to ^99mTc-TF transportation. In vivo studies, dynamic planar imaging, and single photon emission computed tomography (SPECT) experiments with rats were performed to observe alterations to ^99mTc-TF pharmacokinetics using cimetidine (CMT) as an OCT1 inhibitor. Time-activity curves in the liver and heart were acquired from dynamic data, and the ^99mTc-TF uptake ratio was calculated from SPECT. From the in vitro study, ^99mTc-TF was found to be transported by OCT1 and OCT2. When CMT-preloaded rats and control rats were compared, the hepatic accumulation of the ^99mTc-TF was reduced, and the time to peak heart count shifted to an earlier stage. The hepatic accumulation of ^99mTc-TF was markedly suppressed, and the heart-to-liver ratio increased 1.6-fold. The pharmacokinetics of ^99mTc-TF were greatly changed by OCT1 inhibitor. Even in humans, the administration of OCT1 inhibitor before cardiac SPECT examination may reduce ^99mTc-TF hepatic accumulation and contribute to the suppression of artifacts and the improvement of SPECT image quality.

Assessment of drug transporters involved in the urinary secretion of [99mTc]dimercaptosuccinic acid

INTRODUCTION

We clarified the renal uptake and urinary secretion mechanism of [^99mTc]dimercaptosuccinic acid ([^99mTc]DMSA) via drug transporters in renal proximal tubules.

METHODS

[^99mTc]DMSA was added to human embryonic kidney 293 cells expressing human multidrug and toxin extrusion (MATE)1 and MATE2-K, carnitine/organic cation transporter (OCTN)1 and OCTN2, and organic cation transporter (OCT)2; to Flp293 cells expressing human organic anion transporter (OAT)1 and OAT3; and to vesicles expressing P-glycoprotein (P-gp), multidrug resistance associated protein (MRP)2, MRP4, or breast cancer resistance protein with and without probenecid (OAT inhibitor for both OATs and MRPs). Time activity curves of [^99mTc]DMSA with and without probenecid were established using LLC-PK₁ cells. Biodistribution and single photon emission computed tomography (SPECT) imaging in mice were conducted using [^99mTc]DMSA with and without probenecid.

RESULTS

[^99mTc]DMSA uptake was significantly higher in Flp293/OAT3 than in mock cells. Uptake via OAT3 was inhibited by probenecid. [^99mTc]DMSA uptake into vesicles that highly expressed MRP2 was significantly higher in adenosine triphosphate (ATP) than in adenosine monophosphate (AMP), and probenecid decreased uptake to similar levels as that in AMP. In the time activity curves for [^99mTc]DMSA in LLC-PK₁ cells, probenecid loading inhibited accumulation from the basolateral side into LLC-PK₁ cells, whereas accumulation from the apical side into cells gradually increased. Transport of [^99mTc]DMSA from both sides was low. Biodistribution and SPECT imaging studies showed that [^99mTc]DMSA with probenecid loading resulted in significantly higher accumulation in blood, heart, liver, and bladder after [^99mTc]DMSA injection compared with control mice. Probenecid induced significantly lower accumulation in the kidney after [^99mTc]DMSA injection.

CONCLUSIONS

[^99mTc]DMSA accumulates in renal proximal tubular epithelial cells from blood via OAT3 on the basolateral side, and then a small volume of [^99mTc]DMSA will be excreted in urine via MRP2. ADVANCES IN KNOWLEDGE: [^99mTc]DMSA accumulates via OAT3 in renal proximal tubular epithelial cells and is slightly excreted from the cells via MRP2. IMPLICATIONS FOR PATIENT CARE: [^99mTc]DMSA may be useful for measuring renal transport function with OAT3 in patients.

[131I]MIBG exports via MRP transporters and inhibition of the MRP transporters improves accumulation of [131I]MIBG in neuroblastoma

INTRODUCTION

¹³¹I-labeled m-iodobenzylguanidine ([¹³¹I]MIBG) has been used to treat neuroblastoma patients, but [¹³¹I]MIBG may be immediately excreted from the cancer cells by the adenosine triphosphate binding cassette transporters, similar to anticancer drugs. The purpose of this study was to clarify the efflux mechanism of [¹³¹I]MIBG in neuroblastomas and improve accumulation by inhibition of the transporter in neuroblastomas.

METHODS

[¹³¹I]MIBG was incubated in human embryonic kidney (HEK)293 cells expressing human organic anion transporting polypeptide (OATP)1B1, OATP1B3, OATP2B1, organic anion transporter (OAT)1 and OAT2, organic cation transporter (OCT)1 and OCT2, and sodium taurocholate cotransporting polypeptide, and in vesicles expressing P-glycoprotein (MDR1), multidrug resistance associated protein (MRP)1-4, or breast cancer resistance protein with and without MK-571 and probenecid (MRP inhibitors). Time activity curves of [¹³¹I]MIBG with and without MK-571 and probenecid were established using an SK-N-SH neuroblastoma cell line, and transporter expression of multiple drug resistance was measured. Biodistribution and SPECT imaging examinations were conducted using [¹²³I]MIBG with and without probenecid in SK-N-SH-bearing mice.

RESULTS

[¹³¹I]MIBG uptake was significantly higher in OAT1, OAT2, OCT1, and OCT2 than in mock cells. Uptake via OCT1 and OCT2 was little inhibited by MK-571 and probenecid. [¹³¹I]MIBG uptake into vesicles that highly expressed MRP1 or MRP4 was significantly higher in ATP than in AMP, and these inhibitors restored uptake to levels similar to that in AMP. Examining the time activity curves for [¹³¹I]MIBG in SK-N-SH cells, higher expressions of MDR1, MRP1, MRP4, and MK-571, or probenecid loading produced significantly higher uptake than in control at most incubation times. The ratios of tumors to blood or muscle in SK-N-SH-bearing mice were significantly increased by probenecid loading in comparison with normal mice.

CONCLUSIONS

[¹³¹I]MIBG exports via MRP1 and MRP4 in neuroblastoma. The accumulation and tumor-to-blood or muscle ratios of [¹³¹I]MIBG are improved by inhibition of MRPs with probenecid in neuroblastoma. ADVANCES IN KNOWLEDGE: [¹³¹I]MIBG, widely used for treatment of neuroendocrine tumors including neuroblastoma, is excreted via MRP1 and MRP4 in neuroblastoma.

IMPLICATIONS FOR PATIENT CARE

Loading with probenecid, OAT, and MRP inhibitors improves [¹³¹I]MIBG accumulation.

Design protocol of microjet mixers for achieving desirable mixing times with arbitrary flow rate ratios

We extensively examined the performance of microjet mixers.

Elevated 1-h plasma glucose following 75-g oral glucose load is a predictor of arterial stiffness in subjects with normal glucose tolerance

AIMS

The study aimed to investigate arterial stiffness in subjects with normal glucose tolerance.

METHODS

BMI, systolic blood pressure, fasting plasma glucose, lipid variables, ankle-brachial pressure index and brachial-ankle pulse wave velocity were measured in 2059 subjects from Takasaki city, located approximately 100 km north of Tokyo in Japan. Following a 75-g oral glucose tolerance test, only subjects with normal glucose tolerance were selected.

RESULTS

One-hour post-challenge plasma glucose levels were correlated with brachial-ankle pulse wave velocity values (r = 0.340, P < 0.0001). When subjects with normal glucose tolerance were divided into three groups-group 1 (1-h plasma glucose < 8.56 mmol/l, n = 1595), group 2 (1-h plasma glucose ≥ 8.56 and < 10.17 mmol/l, n = 334) and group 3 (1-h plasma glucose ≥ 10.17 mmol/l, n = 130)-the brachial-ankle pulse wave velocity of group 3 (1473 ± 322 cm/s) was significantly higher than that of group 2 (1355 ± 252 cm/s) and brachial-ankle pulse wave velocity of group 2 was also significantly higher than that of group 1 (1275 ± 212 cm/s).

CONCLUSIONS

We have identified that, in normal glucose tolerance, arterial stiffness is advanced in subjects with higher 1-h post-challenge plasma glucose in spite of the normal range for BMI, systolic blood pressure, fasting plasma glucose and lipid variables. Higher 1-h plasma glucose level is a risk factor for arterial stiffness in normal glucose tolerance.

Impaired blood rheology in critically ill patients in an intensive care unit

Critically ill patients are at increased risk of thromboembolic complications. Japanese patients admitted to the intensive care unit of Gunma University Hospital were divided into critically ill (high score) and moderately ill (low score) groups according to mean Acute Physiology and Chronic Health Evaluation (APACHE) II score. White blood cell count, potassium, creatinine, immunoglobulin G and blood passage time, measured using the microchannel method, were significantly higher and the platelet aggregation score and platelet count were significantly lower in the high-score group than in the low-score group, but other haemorheological parameters did not differ significantly between the two groups. White blood cell count, potassium, creatinine, APACHE II score and levels of immunoglobulins G, A and M were positively correlated with blood passage time in all patients. Critically ill patients had impaired blood rheology, which could result from increased white blood cell count, potassium, creatinine and immunoglobulins and may be associated with the pathophysiology of the thromboembolic process.

Relationship between triglyceride concentrations and LDL size evaluated by malondialdehyde-modified LDL

BACKGROUND

Hypertriglyceridemia is associated with decreased HDL-cholesterol (HDL-C) and increased small dense LDL. In addition, small dense LDL is known to be susceptible to oxidation.

METHODS

We measured LDL particle size, using gradient gel electrophoresis, and malondialdehyde-modified LDL (MDA-LDL), using an ELISA, and investigated the association between triglyceride (TG) concentrations, LDL size, and MDA-LDL.

RESULTS

TG concentrations correlated negatively with the predominant LDL size (r = -0.650) and HDL-C concentration (r = -0.556). The relationship between TG concentration and LDL size, evaluated by measuring MDA-LDL, distinguished subgroups derived from four subfractions of TG concentrations and four distribution ranges of LDL size. These experiments indicated that there is a threshold for oxidation susceptibility at an LDL size of 25.5 nm and a TG concentration of 1500 mg/L. To investigate the relationship between LDL size, MDA-LDL concentration, and other lipids (TGs, HDL-C, apolipoprotein B, and total cholesterol), we evaluated them in control subjects and patients with diabetes mellitus or hypertriglyceridemia. When the size range for normal LDL was postulated to be 25.5 < or = phi (LDL diameter) < 26.5 nm, the MDA-LDL concentration was significantly higher in the subgroups of patients with LDL in the size range 24.5 < or = phi < 25.5 nm compared with patients with normal LDL. This result also suggests that the threshold is at a LDL size of 25.5 nm.

CONCLUSION

The threshold for oxidation susceptibility coincided with the point of LDL size separation between the LDL subclass patterns A and B as an atherosclerotic risk.

Inhibitory effect of TAS-301, a new synthesized constrictive remodeling regulator, on renarrowing after balloon overstretch injury of porcine coronary artery

The purpose of this study was to determine the efficacy and the possible mechanism of action of a recently synthesized drug, TAS-301 [3-bis(4-methoxyphenyl)methylene-2-indolinone], on stenosis after balloon overstretch injury of porcine arteries. We measured the diameter of vessels by angiography and conducted histological analysis. The oral administration of TAS-301 kept dilated the angiographic luminal diameter of injured segment 4 weeks after overstretch injury and reduced calculated stenosis ratio in a dose-dependent manner, significantly reducing it at doses of 30 and 100 mg/kg. Histopathological analysis showed that TAS-301 significantly reduced the adventitial area at doses of 30 and 100 mg/kg with moderate reduction of the neointimal area, resulting in the larger residual lumen. In an in vitro assay, TAS-301 dose dependently inhibited the proliferation of adventitial fibroblasts stimulated by basic fibroblast growth factor or transforming growth factor-beta(1). In addition, the drug reduced adventitial fibroblast-mediated three-dimensional collagen gel contraction. These findings indicate that TAS-301, the first compound developed for targeting the constrictive remodeling, showed a high inhibitory potency on coronary artery stenosis of micropigs after injury, mainly due to inhibition of adventitial fibroblast proliferation and of the contractile ability of myofibroblasts. Our results suggest the strong possibility that TAS-301 may be efficacious for prevention of restenosis after angioplasty and the need to examine the therapeutic usefulness of this drug in clinical trials.

Effects of MET-88, a gamma-butyrobetaine hydroxylase inhibitor, on tissue carnitine and lipid levels in rats

MET-88, 3-(2,2,2-trimethylhydrazinium) propionate, suppresses carnitine synthesis by inhibiting (gamma-butyrobetaine hydroxylase. The purpose of this study was to clarify the effects of suppression of carnitine synthesis on carnitine and lipid contents in tissues. MET-88 (50, 100, 200 or 400 mg/kg/d) was administered orally to male SD rats for 10, 30 or 60 d. Total carnitine and lipid (triglycerides, non-esterified fatty acids) contents were measured in heart and liver. In both tissues, treatment with MET-88 dose-dependently decreased total carnitine levels, and the reduction reached the plateau state after 30 d at each dose. MET-88 had no effect on lipid content in the heart, but increased the lipid content in the liver at the highest doses. Treatment with MET-88 at 400 mg/kg for 60 d resulted in no pathologic findings in the histological study, and also had no effect on parameters of liver function such as glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase as judged from the results of blood biochemical analysis. We concluded that long-term treatment with MET-88 decreased the carnitine content to a constant level in both heart and liver, but had no effect on lipid contents in the heart, although it affected lipid metabolism in the liver.

Inhibitory effects of bovine lactoferrin on the adherence of enterotoxigenic Escherichia coli to host cells

Adherence is an essential and prerequisite step for the colonization of mucosal surfaces by enterotoxigenic Escherichia coli (ETEC). We studied the effect of bovine lactoferrin (BLF) on the adherence of ETEC to human epithelial cells in vitro, and to intestinal mucosa of ICR germfree mice in vivo. In the in vitro study, BLF was found to inhibit the adherence of ETEC. This adhesion-inhibiting activity of BLF was found to lessen with decreasing BLF concentration, but the data obtained suggest a positive inhibitory effect of BLF against the adhesion of ETEC cells. In the in vivo study, the counts of adherent bacteria in various sections of the intestinal tract (duodenum, jejunoileum, and large intestine) were lower in the BLF group than in the control group, suggesting the possible action of BLF as an intestinal tract adherence-blocking agent with regards to ETEC.

Dynamic reaction in a homogeneous HDL-cholesterol assay visualized by electron microscopy

BACKGROUND

Measurement of HDL-cholesterol (HDL-C) by homogeneous assays with automated analyzers is replacing precipitation methods. However, in this reaction-type assay, interactions between the reagents and lipoproteins remain unknown.

METHODS

Electron microscopy was used to investigate the reactions in a homogeneous HDL-C assay. Negative staining with 10 g/L uranyl acetate was performed for lipoprotein visualization by electron microscopy. Observations of the interactions between lipoproteins and the reagents of a polyanion-polymer/detergent assay were achieved by cooling the reaction mixture in ice water. This treatment also allowed observation of the time course of the reaction.

RESULTS

In the first-reagent reaction (polyanion-polymer), every lipoprotein aggregated almost completely. In the second-reagent reaction (enzymes and detergent), only HDL in the lipoprotein aggregates was selectively resolved and reacted enzymatically. Reagent 1 contains two important substances: polyanion and synthetic polymer. Using x-ray microanalysis, we confirmed that aggregation of lipoproteins in the first reaction occurred through interaction with the phosphotungstate of the polyanion.

CONCLUSION

Electron microscopy morphologically revealed the dynamic reaction in a homogeneous HDL-C assay.

Normalization of reproductive function in germfree mice following bacterial contamination

The capacity for reproduction in germfree mice remain inferior to their conventional counterparts even after improvement of feed and other such rearing conditions. The authors provide evidence of increased reproductive capacity in germfree mice following association with bacteria. Estrous cycles were normalized in female mice accidentally contaminated with bacteria, and in mice given fecal suspensions of the accidentally contaminated mice per os. Significant rises were seen in their copulation and implantation rates, reaching levels comparable to values in conventional mice. In male mice, bacterial contamination induced significant increase in sperm motility. Bacteria were identified in the feces of the contaminated mice, and reproductive capacity was examined in mice associated with the identified bacteria. As a result, normalization of the estrous cycle, and rises in copulation and implantation rates were noted in B. distasonis and C. perfringens di-associated mice. Values from B. subtilis mono-associated mice were comparable to those in germfree mice. These results from our accidental contamination indicate that B. distasonis and C. perfringens are capable of normalizing estrous cycles in female germfree mice, and in increasing their reproductive capacity by raising their rates of copulation and implantation.

TAS-301, an inhibitor of smooth muscle cell migration and proliferation, inhibits intimal thickening after balloon injury to rat carotid arteries

The purpose of this study was to determine the efficacy and the possible mechanism of action of a recently synthesized drug, TAS-301 [3-bis (4-methoxyphenyl)methylene-2-indolinone], on intimal formation in comparison with those of tranilast, the clinical efficacy of which was reported earlier. Rat carotid arteries were injured using a balloon catheter. Neointimal thickening, measured 14 days after injury, was reduced by the oral administration of TAS-301 in a dose-dependent fashion (3-100 mg/kg), and the effect of TAS-301 at a dose of 100 mg/kg was significantly greater than that of tranilast (300 mg/kg). Fewer cells were found on the intima of balloon-injured arteries of TAS-301-treated rats than on arteries of tranilast-treated rats. In an in vitro assay, TAS-301 inhibited the migration of smooth muscle cells (SMCs) stimulated by platelet-derived growth factor-BB, insulin-like growth factor-1 or heparin-binding epidermal growth factor-like growth factor. In addition, TAS-301 and tranilast reduced the proliferation of medial and intimal SMCs at 4 and 8 days, respectively, after the injury. In vitro, TAS-301 inhibited basic fibroblast growth factor-induced proliferation of SMCs dose dependently. These findings indicate that TAS-301 shows a higher inhibitory potency on intimal formation than tranilast due to inhibition of both migration of medial SMCs and proliferation of medial and intimal SMCs. Our results suggest that further evaluation of TAS-301 as an inhibitor of postangioplasty intimal thickening is warranted.

Cardioprotective profile of MET-88, an inhibitor of carnitine synthesis, and insulin during hypoxia in isolated perfused rat hearts

3-(2,2,2-trimethylhydrazinium) propionate (MET-88) is an inhibitor of carnitine synthesis. This study was carried out to investigate whether or not reduction of carnitine content could attenuate hypoxic damage in isolated perfused rat hearts. Rats were divided into four groups: 1) vehicle control; 2) pretreatment with MET-88 (MET-88); 3) application of insulin (500 muU/mL) in the perfusate (insulin); and 4) pretreatment with MET-88 and application of insulin (MET-88 + insulin). MET-88 (100 mg/kg) was orally administered once a day for 10 days until the day before the experiments. Hearts were initially perfused for a 10 min period under normoxia, followed by a 30 min period under hypoxia. Hearts were frozen at the end of hypoxia for the measurement of high-energy phosphates, carnitine derivatives, and glycolysis intermediates. In a separate series of untreated and MET-88 treated hearts, exogenous glucose and palmitate oxidation was measured. MET-88 decreased the extent of the depression of cardiac contractility (+dP/dt), and aortic flow during the hypoxic state. Insulin also improved cardiac function, and co-treatment of MET-88 and insulin additionally improved cardiac function during hypoxia. MET-88 prevented the decrease of high-energy phosphate and the increase of long-chain acylcarnitine after 30 min of hypoxic perfusion. In addition, MET-88 increased the steady state of glucose oxidation in hypoxic perfused rat hearts. These results indicate that MET-88 has cardioprotective effects on contractile function and energy metabolism of isolated perfused rat hearts in a hypoxic condition. Preventing the accumulation of long-chain acylcarnitine may serve to protect hypoxic hearts.

Development of a CAI program entitled 'Introduction to Nursing Process'. Requirement for nursing education in Japan

A new teaching strategy is required in nursing education in Japan. A multimedia CAI (Computer Assisted Instruction) program entitled "Introduction to Nursing Process." was developed. The aim of this study was to examine whether CAI could assist students' knowledge acquisition, and increase their motivation and readiness to learn clinical nursing practice. This study involved the process of developing CAI and a pilot study for measuring and evaluating the CAI program. Results demonstrate that CAI can increase students' understanding about the nursing process, enhance their motivation to learn, and provide realistic situations describing the concept of nursing the process.

Beneficial effect of MET-88, a gamma-butyrobetaine hydroxylase inhibitor, on energy metabolism in ischemic dog hearts

The effect of MET-88 [3-(2, 2, 2-trimethylhydrazinium) propionate], a gamma-butyrobetaine hydroxylase inhibitor, on the ischemic changes of energy metabolism was studied in the anesthetized dog. In the dog pretreated orally with MET-88 (50, 100 or 200 mg/kg/day) or placebo for 10 days, the left anterior descending coronary artery was occluded for 60 min, and the myocardium was taken from the left anterior descending coronary area (ischemic area) and left circumflex area (nonischemic area) for metabolic analysis. In the ischemic area, occlusion of the left anterior descending coronary artery decreased the tissue levels of adenosine triphosphate, adenosine diphosphate and creatine phosphate, increased the tissue levels of adenosine monophosphate and lactate, and decreased the value of the energy charge potential. These metabolic alterations, induced by occlusion of the left anterior descending coronary artery, were dose-dependently attenuated by MET-88. In the nonischemic area, MET-88 did not markedly change either the tissue levels of energy metabolites or the value of the energy charge potential. These results indicate that MET-88 attenuates the derangement of the energy metabolism in the ischemic myocardium, without affecting the energy metabolism in the nonischemic myocardium.

A simple and reproducible cerebral thrombosis model in rats induced by a photochemical reaction and the effect of a plasminogen-plasminogen activator chimera in this model

In this study a new model of cerebral ischemia, based on a middle cerebral artery (MCA) thrombosis in rats is described. Furthermore, the effect of the novel plasminogen activator (SUN9216), a plasminogen-plasminogen activator chimera, comprising the fibrin kringle 1 domain of a plasminogen, and the two kringles, and the serine protease domains of wild-type tissue plasminogen activator (t-PA), including a modification of the mannose glycosylation site on the kringle 1 of t-PA (PK1de1FE1X), was studied in this model. In the newly described model of thrombotic cerebral ischemia, an occlusive thrombus occurred usually within 8 min in the MCA as a consequence of an endothelial injury subsequent to a photochemical reaction between a systemically administered photosensitive dye (rose bengal) and a transillumination of the MCA with a high-intensity green light with a wavelength of 540 nm. The study was quantitated by means of pathological examination of the MCA and the brain. A platelet-rich thrombus was observed in the MCA using electron microscopical analysis based on ion beam bombardment. At 24 hr after induction of the thrombus, the brain was removed from 13 control animals, nine coronal sections were stained from each brain with triphenyltetrazoliumchloride (TTC), and the ischemic area was quantitated. A constant area of infarction was observed in the cortex and the lateral part of the basal ganglia. In a second group (n = 8), at 1 or 8 weeks after induction of the thrombosis in the MCA, the coronal sections were stained with hematoxylin and eosin.(ABSTRACT TRUNCATED AT 250 WORDS)

Dissociation of photoreceptor cells from the pineal organ of the lamprey, Lampetra japonica

Photoreceptor cells, nerve cells and supporting cells were dissociated from the pineal organ of the river lamprey, Lampetra japonica, by the use of 10 U/ml papain solution at 28 degrees C for 20 min, followed by repeated trituration. With the aid of Nomarski interference-contrast optics, photoreceptor cells, nerve cells and supporting cells were readily identified. Electron-microscopic examination revealed that isolated photoreceptor cells display an outer segment endowed with a few lamellar disks and connected to the inner segment (ellipsoid) via a connecting cilium. The structural features of the dissociated photoreceptor and supporting cells strongly resemble the morphology of the respective cellular elements in situ. We succeeded in culturing dissociated cells for time periods up to 48 h when the procedure described in detail was applied.

Alterations of glomerular basement membrane relevant to haematuria

To elucidate the morphological basis of glomerular haematuria, morphometric analysis of the glomerular basement membrane (GBM) and lamina densa (LD) was performed on silver impregnated samples for electron microscopy. The cases studied consisted of 3 groups: group A, normal controls, being from donors for kidney transplantation; group B, haematuric; and group C, non-haematuric cases with isolated proteinuria. Qualitative analysis revealed that gap formation, splitting, segmental and diffuse thinning of the GBM occur preferentially in haematuric cases. The morphometry of the GBM and LD yielded increased mean values of the GBM and of LD thickness in groups B and C. The coefficient of variation (CV, SD/mean) for the GBM and LD, however, was the highest in group B among the 3 groups, suggesting the most irregular GBM and LD in group B. In addition, CV was significantly higher in cases with splitting, segmental attenuation and gap of the GBM than cases without. The findings suggest that the irregularity of the GBM rather than its mean thickness is clearly associated with splitting and ultimately with haematuria via the gaps produced.

Digital processing methods using scanning densitometer and microcomputer for the structural analysis of a scanning electron micrograph

The fundamental equation of image contrast with practical resolving power is shown taking account of the optical and specimen characteristics. Then, the structural factor which is used to indicate the scattering from the unit of structure to form the periodic object in a scanning electron microscopy can be derived straight-forwardly by digital processing. Based on the Fourier analysis, the reconstruction and subsequent interpretation of structural images such as biological specimens of rat microvilli have been successful. These microvilli must exhibit regularity of a hexagonal lattice consisting of rod-like crystalline arrays. Lattice defects are analysed by means of contrast enhancement, level slicing and histogram plotting techniques. The resolution of SEM can be tested from the granularity distance of coated films by the image sharpening by differentiation and subsequent superimposition of reconstructed images. Furthermore, the structural details in high brightness owing to reducing of the brightness level and filtering the high frequency component have been analysed.