Chymase-dependent angiotensin II formation in the saphenous vein versus the internal thoracic artery

OBJECTIVES

The great saphenous vein graft is known to be less patent than the internal thoracic artery graft. Recently, we reported that chymase-dependent angiotensin II formation plays an important role in the development of intimal hyperplasia in dog grafted veins. In this study we investigated the levels of angiotensin II-forming enzymes, angiotensin-converting enzyme, and chymase in human saphenous veins and internal thoracic arteries.

METHODS

The saphenous vein and internal thoracic artery specimens were obtained from coronary artery bypass grafts of patients during surgical procedures (saphenous vein, n = 16; internal thoracic artery, n = 16). Activities of angiotensin-converting enzyme and chymase were determined by using the extract from the saphenous vein or internal thoracic artery. Sections of the saphenous vein or internal thoracic artery were stained with van Gieson's elastin stain and were immunostained with anti-human chymase antibody.

RESULTS

The activities of angiotensin-converting enzyme in the saphenous vein and internal thoracic artery were 0.34 +/- 0.12 and 0.32 +/- 0.17 mU/mg protein, respectively, and the difference was not significant. The chymase activity in the saphenous vein was significantly higher than that in the internal thoracic artery (saphenous vein, 10.1 +/- 0.81 mU/mg protein; internal thoracic artery, 6.21 +/- 1.86 mU/mg protein). Chymase-positive cells in the saphenous vein were located in both the media and adventitia, and those in the internal thoracic artery were located only in the adventitia. The number of chymase-positive cells in the saphenous vein was about 2.6 times that in the internal thoracic artery.

CONCLUSION

The chymase activity, but not the angiotensin-converting enzyme activity, was significantly higher in the saphenous vein, suggesting that the high levels of chymase activity may be related to the poorer performance of the saphenous vein for use as a bypass conduit.

Rap1 is involved in cell stretching modulation of p38 but not ERK or JNK MAP kinase

Mechanical force or mechanical stress modulates intracellular signal pathways, including the mitogen-activated protein kinase (MAP kinase) cascades. In our system, cell stretching activated and cell contraction inactivated all three MAP kinase pathways (MKK1/2-extracellular signal-regulated kinase (ERK), MKK4 (SEK1)-cJun N-terminal kinase (JNK) and MKK3/6-p38 pathways). However, little is known about the molecular mechanisms that link the mechanical force to the MAP kinase cascades. To test whether Ras and Rap1 are possible components in the stretch-activated MAP kinase pathways, we examined if Ras and Rap1 were activated by cell stretching and if inhibition of their activity decreased the stretch-enhanced MAP kinase activity. Rap1 was activated by cell stretching and inactivated by cell contraction, whereas Ras was inactivated by cell stretching and activated by cell contraction. Rap1GapII and SPA-1, downregulators of Rap1 activity, decreased the stretch-enhanced p38 activity, whereas a dominant-negative mutant of Ras (RasN17) did not inhibit the stretch-initiated activation of MAP kinases. Furthermore, overexpression of Rap1 enhanced p38 activity but not ERK or JNK activity. These results indicate that Rap1 is involved in transducing the stretch-initiated signal to the MKK3/6-p38 pathway, but not to the MEK1/2-ERK or the MKK4 (SEK1)/MKK7-JNK pathway. Thus, Rap1 plays a unique role in force-initiated signal transduction.

Efficient introduction of macromolecules and oligonucleotides into brain capillary endothelial cells using HVJ-liposomes

In this study, we examined the feasibility of introducing macromolecules into cultured mouse brain capillary endothelial cells (MBEC4 cells) by utilizing the hemagglutating virus of Japan (HVJ)-liposomes with fusogenic activity. We used fluorescein isothiocyanate dextran (FITC-Dextran) and FITC-labeled oligodeoxynucleotide (FITC-ODN) as models of a macromolecule and an ODN, respectively. Intracellular fluorescence appeared rapidly after the exposure of MBEC4 cells to FITC-Dextran-containing HVJ-liposomes, and remained detectable for at least 3 days. Only a control level of intracellular fluorescence was seen after treatment with FITC-Dextran alone, FITC-Dextran with empty HVJ-liposomes or FITC-Dextran-containing liposomes without fusogenic activity. In the early phase after administration (0-30 min), the introduction of FITC-Dextran into MBEC4 cells by the HVJ-liposome method resulted in a rapid and time-dependent increase of intracellular fluorescence intensity. Moreover, FITC-ODN was also introduced into MBEC4 cells by the HVJ-liposome method, although FITC-ODN alone was not introduced. These results indicate that the HVJ-liposome method is useful for the efficient introduction of macromolecules, including ODN, into brain capillary endothelial cells.

Tc-99m DTPA renography in patients with collagen disease

PURPOSE

This study evaluated the use of Tc-99m DTPA renography in patients with collagen disease.

MATERIALS AND METHODS

Tc-99m DTPA renal scintigraphy was performed in 28 patients with clinically diagnosed collagen disease. Twenty-two other patients who underwent renal scintigraphy and were subsequently shown to have no kidney abnormalities served as the control group.

RESULTS

One quarter of the patients with collagen disease had abnormal findings of renography, despite the absence of abnormal laboratory data. Renograms were 100% sensitive for the detection of renal disease in patients with collagen disease, and their specificity was 53% when serum blood urea nitrogen, serum creatinine concentration, and proteinuria were the only measures of renal impairment considered. The glomerular filtration rate was not significantly different between the groups, but the bilateral time to peak was significantly greater in the patients with collagen disease. Hydronephrosis was present in 7% of patients with collagen disease.

CONCLUSION

Renography is useful for detecting early changes of renal involvement when the clinical state of collagen disease is evaluated.

Primary retroperitoneal ganglioneuroblastoma in an adult

A case of retroperitoneal ganglioneuroblastoma in a 60-year-old man is reported. This retroperitoneal tumor was surgically removed and pathologic diagnosis was ganglioneuroblastoma. Ganglioneuroblastoma usually occurs in children and is extremely rare in adults. The characteristics are described of an unusual tumor based on the published reports.

Serum levels of fluconazole in patients after cytotoxic chemotherapy for hematological malignancy

We performed a prospective evaluation of pharmacokinetics of fluconazole administered for prophylactic purposes to 19 patients after cytotoxic chemotherapy for hematological malignancies. On days 7 and 15, we obtained 5 ml of blood from each patient. If fluconazole was administered orally, blood samples were drawn 2, 8, and 24 hr after ingestion of the drug. If it was administered intravenously, blood samples were drawn 1, 8, and 24 hr post-injection. Serum fluconazole levels were analyzed by HPLC with ultraviolet light detection. In patients receiving 200 or 400 mg of fluconazole per day, maximal serum levels were 7.9 and 15.6 mg/l and minimum levels were 5.0 and 10.3 mg/l, respectively. There was no significant difference in serum fluconazole levels comparing the levels after oral and intravenous administration, and pharmacokinetic parameters of fluconazole were comparable at each time point within one dose level. However, considerable variation in serum fluconazole levels was noted in this study, as the maximal serum levels ranged from 4.0 to 13.3 mg/l and from 8.7 to 26.9 mg/l in patients receiving 200 and 400 mg of fluconazole orally, respectively. These variations may be associated with prophylactic failures for patients with insufficient fluconazole concentrations. Multiple regression analysis showed significant correlation between serum fluconazole levels and some variables including dose of fluconazole, age, serum aspartate aminotransferase levels and blood urea nitrogen levels. These variations may be associated with disturbance of body water balance, such as massive hemorrhage and dehydration.

Apoptosis signal-regulating kinase 1 (ASK1) is an intracellular inducer of keratinocyte differentiation

Cells differentiate in response to various extracellular stimuli. This cellular response requires intracellular signaling pathways. The mitogen-activated protein (MAP) kinase cascade is a core signal transduction pathway that determines the fate of many kinds of cell. MAP kinase kinase kinase activates MAP kinase kinase, which in turn activates MAP kinase. Apoptosis signal-regulating kinase (ASK1) was identified as a MAP kinase kinase kinase involved in the stress-induced apoptosis-signaling cascade that activates the SEK1-JNK and MKK3/MKK6-p38 MAP kinase cascades. Expression of the constitutively active form of ASK1 (ASK1-DeltaN) in keratinocytes induced significant morphological changes and differentiation markers, transglutaminase-1, loricrin, and involucrin. A transient increase in p21(Cip1/WAF1) reduced DNA synthesis, and cell cycle analysis verified the differentiation. p38 MAP kinase inhibitors, SB202190 and SB203580, abolished the induction of differentiation markers, transglutaminase-1, loricrin, and involucrin. In turn, the induction of differentiation with ceramide in keratinocytes caused an increase in ASK1 expression and activity. Furthermore, normal human skin expresses ASK1 protein in the upper epidermis, implicating ASK1 in in vivo keratinocyte differentiation. We propose that the ASK1-p38 MAP kinase cascade is a new intracellular regulator of keratinocyte differentiation.

[Left ventricular systolic wall motion after exercise stress and myocardial perfusion in patients with ischemic heart disease--investigation by ECG gated myocardial tomography]

To investigate regional left ventricular (LV) wall motion (WM) after recovery from myocardial ischemia, we performed ECG-gated myocardial perfusion tomography with 99mTc-MIBI (G-SPECT) in patients with ischemic heart disease (IHD). In addition, we compared the left ventricular (LV) systolic function obtained by G-SPECT at rest with that obtained by contrast left ventriculography (LVG). We performed G-SPECT at 30 minutes after exercise stress (Ex-30) and 3 hours after exercise (rest). LVWM and LV ejection fractions (EF) were analyzed by the QGS (quantitative gated SPECT) program. The LV was divided into 9 segments and regional WM (RWM) was analyzed quantitatively. In addition, myocardial perfusion was assessed quantitatively. In 64 patients with several different types of heart disease, EF obtained by G-SPECT correlated well with LVG-EF (r = 0.907, p < 0.001), and RWM of G-SPECT coincided well with that of LVG (kappa value 0.67, p < 0.01). Eighty patients with suspected IHD were divided according to Ex-Rest myocardial perfusion. In 83% of patients with Ex-induced perfusion abnormalities disappeared completely at rest, and in 58% of patients with Ex-induced abnormalities disappeared incompletely, RWM abnormalities which were observed at Ex-30 improved at rest and as did EF. In 79% of patients with a fixed defect (FD), RWM abnormalities and EF at Ex-30 did not differ with those at rest, but in 12% of the patients, the RWM abnormality of Ex-30 improved at rest. In most myocardial segments that had recovered from transient ischemia, RWM abnormalities persisted at least 30 minutes after Ex (stunning). In a small portion of the myocardial segments regarded as having myocardial necrosis because of a fixed perfusion abnormality, RWM abnormalities at Ex-30 improved at rest. These segments were supposed to contain viable myocardium. In conclusion, G-SPECT is a powerful method for clarifying the relation between the regional systolic function and myocardial perfusion.

A new operative method of correcting cryptotia using large Z-plasty

A large Z-plasty on the postauricular surface of the ear has been used for successful reconstruction of cryptotia. This technique provides extensive skin coverage of the posterior auricle without skin grafting. The technique is easy and simple. The natural hairline is not disturbed and the temporoauricular sulcus is emphasised. Almost all of the scar is hidden behind the auricle. It has been performed on 17 patients with no recurrence of the cryptotia. One patient had partial congestion in the cranial-flap tip, which improved within 1 week. There were no other complications.

Comparative study of effects of angiotensin II receptor antagonist, KD3-671, and angiotensin converting enzyme inhibitor, enalaprilat, on cough reflex in guinea pig

Angiotensin converting enzyme (ACE) inhibitor prevents the inactivation of bradykinin by inhibiting ACE activity, leading to side effects such as dry cough and angioedema. KD3-671 is a novel nonpeptide angiotensin II antagonist which is expected to exhibit persistent hypotensive action without these side effects. In this study, we investigated the relationship between the pharmacokinetics and cough-inducing effect of this drug in guinea-pig, compared with that of an ACE inhibitor, enalaprilat. KD3-671 was not significantly different from the vehicle treatment in the ability to induce coughing, whereas enalaprilat significantly enhanced coughing compared with the vehicle treatment. Thus, as expected from its mechanism of pharmacological action, KD3-671 did not induce coughing. We suggest that the citric acid-induced guinea pig coughing model will be useful in preclinical studies to examine the effect of drug on pulmonary function.

Transcellular transport of genistein, a soybean-derived isoflavone, across human colon carcinoma cell line (Caco-2)

Genistein, a soybean-derived isoflavone, is thought to have an anticarcinogenic action, but little is known about the cellular mechanisms of its intestinal absorption. This study was designed to investigate the absorption mechanisms of genistein using human colon carcinoma cell line, Caco-2 cells. The apical-to-basolateral transcellular transport of genistein across a Caco-2 cell monolayer was significantly greater than that in the opposite direction. An uptake experiment revealed that cellular uptake of genistein by Caco-2 cells was concentrative. The transcellular transport of genistein was saturable and temperature-dependent, and was inhibited by other flavonoids such as rutin, quercetin, (+)-catechin and (-)-epicatechin. These results suggest that genistein is transported across Caco-2 cells by a carrier-mediated system, located on the apical membrane.

Retroauricular flap: its clinical application and safety

We report the application and safety of the retroauricular flap in 38 cases. The flap was used on the anterior auricular surface in 21 cases, in the peri-auricular region in five cases, in the region of the preauricular sideburn area in two cases, in the malar region in six cases, in the eyelid in three cases and in the intraorbital region in one case. When this flap was used in the auricular or periauricular region, the blood circulation was safe and the appearance was aesthetically good in flaps pedicled by the postauricular vessels or by the superficial temporal vessels. However, when the defect was more remote from the auricle, the blood circulation of the flaps pedicled by superficial temporal vessels, whether subcutaneous pedicle flaps or free flaps, was unstable. In some cases there was extensive or partial necrosis of the distal area of the flap. On the other hand, the free flaps pedicled by the postauricular vessels had satisfactory blood circulation, but the vessels were sometimes short, narrow and difficult to find, especially the veins. In these cases, we were obliged to use the superficial temporal vessels. A further problem is that some of the patients, especially younger women, were dissatisfied when the retroauricular flap was used in the malar region because of the reddish colour of the flap.

Rapid patterning in 2-D cultures of Dictyostelium cells and its relationship to zonal differentiation

Rapid patterning has been observed in confined 2-D cultures of Dictyostelium discoideum Ax-2 cells as an outer dark zone and a inner light zone. The width of outer zone was usually approximately100 microm, irrespective of the size of cell masses under atmospheric conditions. The width of the outer zone, however, changed depending on external O2 concentrations and reached up to 250 microm at 100% O2. A clear regional difference in tetramethyl rhodamine methyl ester (TMRM) staining was noticed between the outer zone and the inner zone: the inner zone was more strongly stained with TMRM than the outer zone, which faced the air. Using inhibitors of oxidative phosphorylation (dinitrophenol (DNP) or NaN3) and a specific inhibitor of CN-resistant respiration (benzohydroxamic acid (BHAM)), it has been demonstrated that the outer zone is basically formed by the O2 threshold for oxidative phosphorylation, while the inner cells mainly perform cyanide-resistant respiration. When cells around the early mound stage (just before prestalk and prespore differentiation) were cultured as 2-D cell masses, ecmA-expressing cells (pstA cells), ecmB-expressing cells (pstB cells) and D19-expressing cells (prespore; psp cells), arose in a position-dependent manner in the outer zone. In the inner zone, cell motility seemed to be markedly impaired and neither prestalk nor prespore differentiation occurred. In addition, once-differentiated prespore cells were found to dedifferentiate rapidly in the inner zone. The reason for dedifferentiation as well as for failure of cells to differentiate in the inner zone is discussed with reference to O2 radicals.

Involvement of glial cells in cyclosporine-increased permeability of brain endothelial cells

1. To test whether astrocytes participate in cyclosporine-induced dysfunction of the blood-brain barrier, we examined the effects of cyclosporine on the permeability of the mouse brain endothelial (MBEC4) cells cocultured with C6 glioma cells, each cell layer placed on the top and bottom of the insert membrane, respectively. 2. The presence of C6 cells remarkably aggravated cyclosporine-increased permeability of MBEC4 cells to sodium fluorescein. 3. In light of these findings, the possibility that astroglial cells could contribute to the occurrence of cyclosporine-induced dysfunction of the blood-brain barrier triggering neurotoxicity should be considered.

Characteristics of choline transport across the blood-brain barrier in mice: correlation with in vitro data

PURPOSE

We examined the functional properties of choline transport across the blood-brain barrier (BBB) in mice. We compared the kinetic parameters and transport properties with those found in our in vitro uptake experiments using mouse brain capillary endothelial cells (MBEC4).

METHODS

The permeability coefficient-surface area product (PS) values of [3H]choline at the BBB were estimated by means of an in situ brain perfusion technique in mice.

RESULTS

[3H]Choline uptake was well described by a two-component model: a saturable component and a nonsaturable linear component. The [3H]choline uptake was independent of pH and Na+, but was significantly decreased by the replacement of Na+ with K+. Various basic drugs, including substrates and inhibitors of the organic cation transporter, significantly inhibited the [3H]choline uptake. These in situ (in vivo) results corresponded well to the in vitro results and suggest that the choline transporter at the BBB is a member of the organic cation transporter (OCT) family.

CONCLUSION

The choline transport mechanism at the BBB is retained in MBEC4.

Angiotensin II receptor antagonist, L-158,809, prevents intimal hyperplasia in dog grafted veins

We investigated the levels of the angiotensin II-forming enzymes, chymase and angiotensin converting enzyme (ACE), in dog grafted veins, and studied the effect of an angiotensin II type 1 receptor antagonist, L-158,809, on vascular proliferation in the grafted veins. The right external jugular vein was grafted to the ipsilaterial carotid artery. In the group treated with L-158,809, the drug (10 mg/kg per day, p.o.) were administered orally from 7 days before the operation to 28 days after it, while the others were administrated placebo. In the placebo-treated group, the chymase activity in the grafted veins was increased about 10-fold and the ACE activity was doubled. The areas of intima and media were significantly increased in the grafted veins in the placebo-treated group. L-158,809 significantly reduced the intimal area of the grafted veins. An angiotensin II receptor antagonist, L-158,809, prevented the vascular proliferation in the grafted veins, and the development of the proliferation may depend on activation of local angiotensin II formation.

Inhibition of P-glycoprotein by orange juice components, polymethoxyflavones in adriamycin-resistant human myelogenous leukemia (K562/ADM) cells

We investigated the effects of the ethyl acetate extract of grapefruit juice (GFJ), that of orange juice (OJ) and their components on the uptake of [(3)H]vincristine into adriamycin-resistant human myelogenous leukemia cells. Its uptake was increased by the extracts of GFJ and OJ up to 7- and 3-fold, respectively, as well as verapamil and cyclosporin A. OJ components, i.e. 3,3',4',5,6,7,8-heptamethoxyflavone, nobiletin and tangeretin, also increased the uptake of [(3)H]vincristine in a concentration-dependent manner. Although GFJ components, dihydroxybergamottin and bergamottin, significantly increased the uptake, their potencies were considerably weaker than those of OJ components. These data suggest that OJ components inhibit P-gp-mediated efflux of [(3)H]vincristine, resulting in the intracellular accumulation of chemotherapeutic drugs. These components may become candidates of multi-drug resistance reversing agents in cancer chemotherapy.

Human placental transport of vinblastine, vincristine, digoxin and progesterone: contribution of P-glycoprotein

To elucidate the role of P-glycoprotein in human placenta, we examined its expression in placenta, and the transcellular transport and uptake of P-glycoprotein substrates in cultured human placental choriocarcinoma epithelial cells (BeWo cells). The uptake of [(3)H]vinblastine and [(3)H]vincristine into BeWo cells was increased in the presence of a metabolic inhibitor, sodium azide. The basolateral-to-apical transcellular transport of [(3)H]vinblastine, [(3)H]vincristine and [(3)H]digoxin was greater than the apical-to-basolateral transcellular transport. In the presence of cyclosporin A, the basolateral-to-apical transcellular transport of [(3)H]vinblastine, [(3)H]vincristine and [(3)H]digoxin was significantly increased, and the apical-to-basolateral transcellular transport was decreased. The uptake of [(3)H]vinblastine, [(3)H]vincristine and [(3)H]digoxin into BeWo cells was significantly enhanced in the presence of several inhibitors, such as verapamil or mouse monoclonal antibody anti-P-glycoprotein MX-MDR (MRK16) as well as cyclosporin A. Although progesterone significantly enhanced the uptake of [(3)H]vinblastine, [(3)H]vincristine and [(3)H]digoxin into BeWo cells, the uptake of [(3)H]progesterone was not affected by these inhibitors. Immunoblot analysis revealed that P-glycoprotein with a molecular weight of 172 kDa was expressed in BeWo cells and isolated trophoblast cells. Furthermore, P-glycoprotein was detected in human placental brush-border membrane vesicles, but not in human placental basolateral membrane vesicles. In conclusion, these data suggest that P-glycoprotein is expressed on the brush-border membrane (maternal side) of human placental trophoblast cells. P-Glycoprotein is considered to regulate the transfer of several substances including vinblastine, vincristine and digoxin from mother to fetus, and to protect the fetus from toxic substances.

Effect of anti-inflammatory bowel disease drug, E3040, on urate transport in rat renal brush border membrane vesicles

To confirm the assumption that 6-hydroxy-5, 7-dimethyl-2-methylamino-4-(3-pyridylmethyl)benzothiazole (E3040) acts on urate reabsorption by inhibiting urate-anion exchange at the luminal membrane of renal tubules, we investigated the inhibitory effect of E3040 and its two conjugated metabolites on hydroxyl ion (OH(-)) gradient-dependent urate uptake into brush border membrane vesicles from rat renal cortex and compared it with other uricosuric agents. The order of potency was AA193 (5-chloro-7, 8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-carboxylic acid)>benzbromarone>E3040>probenecid>E3040 sulfate>E3040 glucuronide. Furthermore, kinetic analysis revealed that E3040 may be a competitive inhibitor of the OH(-) gradient-dependent uptake of urate into brush border membrane vesicles.

New scheme of the biosynthesis of formononetin involving 2,7,4'-trihydroxyisoflavanone but not daidzein as the methyl acceptor

Glycyrrhiza echinata cell-free extract produced isoformononetin by the 7-O-transmethylation of daidzein from S-adenosyl-L-methionine (SAM). When the yeast microsome expressing 2-hydroxyisoflavanone synthase was mixed with the cell-free extract and incubated with liquiritigenin and SAM, formononetin emerged. Furthermore, the cell-free extract yielded formononetin on incubation with 2,7,4'-trihydroxyisoflavanone and SAM. We propose a novel pathway of formononetin biosynthesis involving 2,7,4'-trihydroxyisoflavanone as the methyl acceptor.

Diffusion and deformations of single hydra cells in cellular aggregates

Cell motion within cellular aggregates consists of both random and coherent components. We used confocal microscopy to study the center of mass displacements and deformations of single endodermal Hydra cells in two kinds of cellular aggregates, ectodermal and endodermal. We first carefully characterize the center of mass displacements using standard statistical analysis. In both aggregates, cells perform a persistent random walk, with the diffusion constant smaller in the more cohesive endodermal aggregate. We show that a simple parametric method is able to describe cell deformations and relate them to displacements. These deformations are random, with their amplitude and direction uncorrelated with the center of mass motion. Unlike for an isolated cell on a substrate, the random forces exerted by the surrounding cells predominate over the deformation of the cell itself, causing the displacements of a cell within an aggregate.

Comparative pharmacodynamic analysis of Q-T interval prolongation induced by the macrolides clarithromycin, roxithromycin, and azithromycin in rats

In order to evaluate the arrhythmogenic potency of macrolide antibiotics in a quantitative manner, we analyzed the influence of clarithromycin (CAM), roxithromycin (RXM), and azithromycin (AZM) on Q-T intervals from pharmacokinetic and pharmacodynamic points of view and in comparison with the potency of erythromycin (EM) previously reported by us for rats. Male Sprague-Dawley rats were anesthetized, and CAM (6.6, 21.6, and 43.2 mg/kg of body weight/h), RXM (20 and 40 mg/kg/h), and AZM (40 and 100 mg/kg/h) were intravenously injected for 90 min to obtain the time courses of drug concentrations in plasma and the changes in the Q-T intervals during and after the drug injections. Distinct Q-T interval prolongation of up to 10 ms was observed with CAM at its clinical concentrations. RXM and AZM evoked Q-T interval prolongation at concentrations higher than their clinical ranges. The potencies for Q-T interval prolongation, assessed as the slope of the concentration-response relationship, were 6.09, 0.536, and 0.989 ms. ml/microg for CAM, RXM, and AZM, respectively. There was hysteresis between the change in the Q-T intervals and the time course of the plasma concentration of each drug. The rank order of clinical arrhythmogenicity was estimated to be EM > CAM > RXM > AZM, as assessed from the present results and our previous report for EM. In conclusion, RXM and AZM were estimated to be less potent at provoking arrhythmia than EM and CAM. These results should be useful for making a safer choice of an appropriate agent for patients with electrocardiographic risk factors.

Influence of Helicobacter pylori infection on development of stress-induced gastric mucosal injury

Immediately after the Great Hanshin Earthquake in Kobe in 1995, the recurrence rate of peptic ulcer in patients infected with Helicobacter pylori was higher than that in patients in whom H. pylori had been eradicated. We evaluated the influence of H. pylori infection on stress-induced gastric mucosal injury in Mongolian gerbils and C57BL/6 mice. These animals were immersed in water for 30, 120, and 720 min 12 weeks after inoculation with H. pylori, and then killed to assess gastric mucosal damage, and to measure cytokine production (interleukin [IL]-1beta, IL-4, IL-6, and IL-10; interferon [IFN]-gamma; and tumor necrosis factor [TNF]-alpha) in the gastric tissue of the mice. The stress treatment for 30 min resulted in a significantly higher bleeding rate and bleeding index among infected gerbils and mice compared with results in uninfected animals. Conversely, the bleeding and ulcer indexes were significantly higher in uninfected gerbils after 720 min of the stress treatment than in infected gerbils. Prior to the stress treatment, gastric IL-1beta and IFN-gamma production was significantly higher in the infected group than in the uninfected group. After 120 min of the stress treatment, TNF-alpha production was increased in the infected group, and IL-1beta and IL-10 production was increased in the uninfected group. However, the production of these cytokines showed no change at 30 min of the stress treatment. These results suggest that H. pylori infection influences the development of gastric mucosal injury in the early phase of stress exposure; cytokines do not play a major role in this process.

Spontaneous symmetry breaking turing-type pattern formation in a confined Dictyostelium cell mass

We have discovered a new type of patterning which occurs in a two-dimensionally confined cell mass of the cellular slime mold Dictyostelium discoideum. Besides the longitudinal structure reported earlier, we observed a spontaneous symmetry breaking spot pattern whose wavelength shows similar strain dependency to that of the longitudinal pattern. We propose that these structures are due to a reaction-diffusion Turing instability similar to the one which has been exemplified by CIMA (chlorite-iodide-malonic acid) reaction. The present finding may exhibit the first biochemical Turing structure in a developmental system with a controllable boundary condition.

Comparison of blood-brain barrier permeability in mice and rats using in situ brain perfusion technique

Here we present a method for measuring the permeability coefficient-surface area product (PS) values at the blood-brain barrier in mice, using the in situ brain perfusion technique originally developed for rats by Takasato et al. (Am J Physiol Heart Circ Physiol 247: H484-H493, 1984). Retrograde infusion into the right external carotid artery increased the carotid perfusion pressure in proportion to the perfusion rate. Intravascular volume and cerebral perfusion fluid flow at a perfusion rate of 1.0 ml/min in mice were similar to those in rats. In addition, the contribution of systemic blood to total flow in the hemisphere was small (only 3. 2%). These findings indicated that this perfusion rate is suitable for mice. The PS values of more than 20 different compounds were determined in mice by using the in situ brain perfusion technique, and comparisons were made with data from rats. There was a close relationship (1:1) between the PS values in mice and rats, indicating that brain capillary permeabilities are similar in mice and rats.

Diagnosis and treatment of 6-pyruvoyl-tetrahydropterin synthase deficiency

We detected a case of 6-pyruvoyl tetrahydropterin synthase (PTPS) deficiency during a neonatal mass screening and considered the differentiation and treatment of the peripheral form of PTPS deficiency. Although single treatment of BH4 had been started, because of the lowered biopterin (B) value, elevated neopterin (N) value, and N/B ratio in the cerebrospinal fluid (CSF), the peripheral form was judged negative and combined treatment with L-dopa and 5-hydroxy tryptophan (5-HTP) was started. Follow-up study will be necessary to confirm the diagnosis of PTPS deficiency.

Thallium-201 myocardial SPET in patients with collagen disease

We analysed stress 201Tl myocardial single photon emission tomography (SPET) in collagen disease patients to evaluate abnormal uptake patterns and their clinical significance in the assessment of the cardiac status of these patients. The main purpose of the study was to evaluate the clinical significance of reverse redistribution. Twenty-two collagen disease patients (13 with progressive systemic sclerosis (PSS) and nine with systemic lupus erythematosus (SLE)) were examined by 201Tl myocardial SPET with exercise (n = 9) or dipyridamole stress (n = 13). For quantitative analysis, each 201Tl SPET polar map was divided into 17 segments, and the 201Tl uptake pattern of each segment was classified into four types. Eighteen (82%) of the patients showed abnormal findings on 201Tl SPET. Of the 374 segments analysed, 295 (79%) were classified as normal, 16 (4%) as reverse redistribution, 49 (13%) as reversible defect and 14 (4%) as fixed defect. Patients were divided into two groups: those with cardiac abnormalities on conventional testing (Group A, n = 10) and those without (Group B, n = 12). The incidences of fixed defect, reversible defect and reverse redistribution were significantly higher (P <0.01, P <0.0005, P <0.05, respectively) in Group A than in Group B. Nine (90%) of the patients in Group A and nine (75%) in Group B showed abnormal findings. No significant difference was found between the PSS and SLE patients in the incidence of the individual uptake patterns. Stress 201Tl myocardial SPET appears to be an effective method of evaluating a wide spectrum of myocardial involvement in collagen disease patients and in assessing their clinical cardiac status. Reverse redistribution is found to be a significant finding in collagen disease patients.

Induction of apoptosis in mouse brain capillary endothelial cells by cyclosporin A and tacrolimus

Although cyclosporin A and tacrolimus are used clinically as potent immunosuppressants, there have been reports of neurotoxicity and encephalopathy. A possible mechanism is that these drugs damage the blood-brain barrier (BBB), inducing dysfunction and increased permeability, and are then able to enter the brain. We studied the cytotoxicity of cyclosporin A and tacrolimus, focused on apoptosis induction, using an immortalized cell line established from BALB/c mouse cerebral microvessel endothelial cells (MBEC4). We found that these two drugs induced cell shrinkage, chromatin condensation and DNA fragmentation, which are characteristics of apoptosis. Our data suggest that the induction of apoptosis on the brain capillary endothelial cells may be at least partly involved in the occurrence of immunosuppressant-induced encephalopathy.

[Successive myocardial fatty acid metabolic imaging in patients with dilated cardiomyopathy: usefulness as a prognostic indicator]

To evaluate the prognostic value of fatty acid metabolic imaging in patients with idiopathic dilated cardiomyopathy (DCM), we performed myocardial imaging with 123I-BMIPP (BMIPP). We studied 23 patients with DCM who were admitted because of congestive heart failure (CHF) and after discharge the stable condition persisted for more than one year. BMIPP imaging was obtained when CHF recovered (first study) and the second study was performed one year after the first study. From BMIPP imaging we calculated % Uptake (percentage of cardiac uptake of isotope to total injected dose) and Defect Score (degree and extent of regional abnormality in BMIPP uptake, DS). In the first study, we performed myocardial imaging with 201T1 to calculate Uptake Ratio of BMIPP (% Uptake of BMIPP divided by % Uptake of 201T1, UR). During the follow up period of 18.2 +/- 9.5 months (4.5-39.6 months) after the second study, cardiac event developed in 8 patients (cardiac death; 4, deterioration of CHF; 4). On univariate analysis, the following indices differed significantly between the event and event-free groups; left ventricular end-systolic dimension, graded DS, UR and % Uptake of 201T1 at the first study, % Uptake of BMIPP and DS at the second study, difference of % Uptake of BMIPP and DS between the first and second study, and newly designed index from graded DS of the first study and its change in the second study (Defect Index, DI). Cox proportional hazard analysis showed that DI (p = 0.0026) and age (p = 0.0262) were independent predictors of cardiac events. In patients with DI > or = 3, the relative risk of cardiac event was 25.0 times greater than that in patients with DI < or = 2. These data suggested that the extent and degree of regional abnormality of BMIPP uptake (DS) and its changes with time were useful for evaluating the prognosis in patients with DCM even though a clinically stable condition is persisting.

Nasal reconstruction based on aesthetic subunits in Orientals

Reconstruction based on the aesthetic subunit principle has yielded good aesthetic outcomes in patients with moderate to severe nasal defects caused by trauma or tumor resection. However, the topographic subunits previously proposed are often unsuitable for Orientals. Compared with the nose in white patients, the nose in Orientals is low, lacks nasal muscle, and has a flat glabella; the structural features of the underlying cartilage and bone are not distinctly reflected in outward appearance. The authors devised aesthetic subunits suitable for Orientals, and they used these units to reconstruct various parts of the nose. The major difference between these units and those presented previously is the lack of soft triangles and the addition of the glabella as an independent unit. The authors divided the nose into the following five topographic units: the glabella, the nasal dorsum, the nasal tip, and the two alae. The border of the nasal dorsum unit was extended to above the maxillonasal suture. The basic reconstruction techniques use a V-Y advancement flap from the forehead to reconstruct the glabella, an island flap from the forehead to reconstruct the nasal dorsum and nasal tip, a nasolabial flap to reconstruct an ala, and a malar flap to reconstruct the cheek. A combination of flaps was used when the defect involved more than one unit. This concept was used for nasal reconstruction in 24 patients. In one patient undergoing reconstruction of the nasal dorsum and in one undergoing reconstruction of the nasal tip, the texture of the forearm flap did not match well, which resulted in a slightly unsatisfactory aesthetic outcome. In one patient in whom the glabella, nasal dorsum, and part of the cheek were reconstructed simultaneously, a web was formed at the medial ocular angle, and a secondary operation was subsequently performed using Z-plasty. In one patient undergoing reconstruction with a forehead flap, defatting was required to reduce the bulk of the subcutaneous flap pedicle at the glabella. However, suture lines were placed in the most inconspicuous sites in all patients, and the use of a trapdoor contraction emphasized the three-dimensional appearance of the nose. The use of these aesthetic subunits for reconstruction offers several advantages, particularly in Oriental patients. Because the nasal dorsum is reconstructed together with the side walls, tenting of the nasal dorsum is avoided, which prevents a flat appearance of the nose. A forehead flap is useful in the repair of complex defects. Defects of the alae should be separately reconstructed with a nasolabial flap to enhance the effect of the trapdoor contraction and to highlight the three-dimensional appearance of the nose. Candidates for reconstruction should be selected on the basis of nasal structure. The results suggest that these units can also be used in some white patients.

Cloning and characterization of a novel RNA-binding protein SRL300 with RS domains

AT-rich element binding factor 1 (ATBF1) mRNA encodes a transcription factor implicated in neuronal differentiation. A cDNA for the protein that can bind the 5'-noncoding sequence of the ATBF1 mRNA was cloned. The deduced protein, termed SRL300, contains a unique RNA-binding region, two large RS domains and many phosphorylation sites. SRL300 protein was detected in both human and rat cells.

Correlating the severity of paraquat poisoning with specific hemodynamic and oxygen metabolism variables

OBJECTIVE

To investigate the hemodynamics and oxygen metabolism of patients with varying degrees of severity of paraquat poisoning.

DESIGN

Prospective, observational, clinical study.

SETTING

Intensive care unit in a university hospital.

PATIENTS

Forty-three consecutive patients with paraquat and/or diquat poisoning were classified into three groups by the severity index of paraquat poisoning (SIPP; hr/mg/L).

INTERVENTIONS

Standard treatments included specific respiratory management, fluid resuscitation, and aggressive circulatory support.

MEASUREMENTS AND MAIN RESULTS

Serum paraquat and diquat levels were measured at arrival, and SIPP was calculated. The cardiac index (CI), left ventricular stroke work index (LVSWI), systemic vascular resistance index (SVRI), oxygen delivery index (DO2I), oxygen consumption index (VO2I), and oxygen extraction ratio (O2ER) were measured at 6, 12, 24, 36, 48, 72, and 96 hrs postadmission. A significant inverse correlation between SIPP and survival time was found in 31 fatal cases (r = .85; p < .001). In the SIPP 10-50 group, CI, DO2I, VO2I, and O2ER were maintained at higher levels than in the SIPP group of <10 (p < .05), whereas SVRI decreased significantly (p < .05). In the SIPP group of >50, CI, LVSWI, SVRI, DO2I, and VO2I decreased, whereas O2ER had a tendency to increase progressively. There was a significant correlation between SVRI and SIPP, O2ER and SIPP, and O2ER and SVRI 24 hrs after admission, respectively (p < .001).

CONCLUSIONS

Paraquat poisoning is characterized by high oxygen consumption with high oxygen extraction, with the degree of derangement based on the severity index. The development of a marked imbalance between increased oxygen demand and decreased oxygen supply because of myocardial depression might be a possible cause of death in circulatory failure.

Effect of bioflavonoids on vincristine transport across blood-brain barrier

Several grapefruit juice bioflavonoids, including quercetin, are reported to stimulate P-glycoprotein-mediated drug efflux from cultured tumor cells. To see whether these bioflavonoids alter the permeation of vincristine across the blood-brain barrier, we conducted experiments with cultured mouse brain capillary endothelial cells (MBEC4 cells) in vitro and ddY mice in vivo. The steady-state uptake of [3H]vincristine by MBEC4 cells was decreased by 10 microM quercetin, but increased by 50 microM quercetin. Similarly, the in vivo brain-to-plasma concentration ratio of [3H]vincristine in ddY mice was decreased by coadministration of 0.1 mg/kg quercetin, but increased by 1.0 mg/kg quercetin. Kaempferol had a similar biphasic effect on the in vitro uptake of [3H]vincristine. Other aglycones tested (chrysin, flavon, hesperetin, naringenin) increased [3H]vincristine uptake in the 10-50 microM range, and glycosides (hesperidin, naringin, rutin) were without effect. We then addressed the mechanism of the concentration-dependent biphasic action of quercetin. Verapamil, a P-glycoprotein inhibitor, inhibited the efflux of [3H]vincristine from MBEC4 cells, while 10 microM quercetin significantly stimulated it. The uptake of [3H]vincristine by MBEC4 cells was increased by inhibitors of protein kinase C, but decreased by phorbol 12-myristate-13-acetate (PMA), as well as by 10 microM quercetin. The phosphorylation level of P-glycoprotein was increased in the presence of 5 microM quercetin or 100 nM PMA, but decreased by the protein kinase C inhibitor H7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine, 30 microM). We conclude that low concentrations of quercetin indirectly activate the transport of [3H]vincristine by enhancing the phosphorylation (and hence activity) of P-glycoprotein, whereas high concentrations of quercetin inhibit P-glycoprotein. Our results indicate that patients taking drugs which are P-glycoprotein substrates may need to restrict their intake of bioflavonoid-containing foods and beverages, such as grapefruit juice.

Propiverine-induced Parkinsonism: a case report and a pharmacokinetic/pharmacodynamic study in mice

PURPOSE

We present a case report of propiverine-induced Parkinsonism. We previously reported the induction of catalepsy by amiodarone, aprindine and procaine, which possess a diethylaminomethyl moiety and demonstrated selective blockade of dopamine D2 receptors by these drugs in mice. We hypothesized that drugs possessing a diethylaminomethyl structure may generally induce Parkinsonism and/or catalepsy.

METHODS

Thus, we performed a study to examine whether oxybutynin, pentoxyverine and etafenone, as well as propiverine, induce catalepsy in mice.

RESULTS

The intensity of drug-induced catalepsy was in the order: haloperidol > etafenone > pentoxyverine > propiverine > oxybutynin. In vivo occupancy of dopamine D1, D2 and mACh receptors in the striatum was also examined. The in vitro binding affinities to the D1, D2 and mACh receptors in the striatum synaptic membrane were within the ranges of 2.4-140 microM, 380-4,200 nM, and 1.2-2,800 nM, respectively.

CONCLUSIONS

These results support the idea that any drug possessing a diethylaminomethyl moiety may contribute to the induction of catalepsy, possibly by occupying dopamine receptors.

Quantitative prediction of catalepsy induced by amoxapine, cinnarizine and cyclophosphamide in mice

Parkinsonism can be a side effect of antipsychotic drugs, and has recently been reported with peripherally acting drugs such as calcium channel blockers, antiarrhythmic agents and so on. In this study, we examined the quantitative prediction of drug-induced catalepsy by amoxapine, cinnarizine and cyclophosphamide, which have been reported to induce parkinsonism. Dose-dependent catalepsy was induced by these drugs in mice. In vivo dopamine D(1), D(2) and muscarinic acetylcholine (mACh) receptor occupancies by these drugs in the striatum were also examined. The in vitro binding affinities (K(i) values) of amoxapine and cinnarizine to dopamine D(1), D(2) and mACh receptors in rat striatal synaptic membrane were 200 and 2900 nM, 58.4 and 76.4 nM and 379 and 290 nM, respectively. Cyclophosphamide did not bind to these receptors at concentrations up to 100 microM. Twenty drugs, including those mentioned above, showed a significant correlation between the observed intensity of catalepsy and the values predicted with a pharmacodynamic model (Haraguchi K, Ito K, Kotaki H, Sawada Y, Iga T. Prediction of drug-induced catalepsy based on dopamine D(1), D(2), and muscarinic acetylcholine receptor occupancies. Drug Metab Disp 1997; 25: 675-684) based on in vivo occupancy of dopamine D(1), D(2) and mACh receptors. We conclude that occupancy of dopamine D(1) and D(2) receptors contributes to catalepsy induction by amoxapine and cinnarizine.

Learning-induced synchronization of a globally coupled excitable map system

We propose a pulse-coupled neural network model in which one-dimensional excitable maps connected in a time-delayed network serve as the neural processing units. Although the individual processing unit has simple dynamical properties, the network exhibits collective chaos in the active states. Introducing a Hebbian learning algorithm for synaptic connections enhances the synchronization of excitation timing of the units within a subpopulation. The synchronizing clusters approximately exhibit a power-law size distribution, suggesting a hierarchy of synchronization. After applying a stationary signal to a subpopulation of the units with learning, the network then reproduces the signal. The learnable time range is much longer than the inherent time scale of the processing units, i.e., the synaptic delay time. Also, the network can reproduce periodic signals with time resolution finer than the delay time. Our present network model can be considered as a temporal association device which operates in chaotic states.

Experiential assessment of endoventricular circular patch plasty in patients with depressed left ventricular function due to ischemia

A concept of volume reduction surgery for patients with end-stage dilated cardiomyopathy was introduced to the surgical aspect. We started consequently to employ this operation for patients with ischemic cadiomyopathy. Between October 1997 and April 1999, 14 patients (mean age 64 years; 12 men, 2 women) underwent endoventricular circular patch plasty (EVCPP) in our institute.

TECHNIQUE

The left ventricle (LV) is opened by placing an incision parallel to the left anterior descending (LAD) coronary artery. An endocardial purse-string suture is placed circumferentially at the root of the posterior papillary muscle. The remaining opening of the cavity is closed with a circular bovine pericardial patch. The excluded edges of LV free wall and septum are directly closed with felt strips.

RESULTS

There were no significant hemodynamic differences in heart rate, cardiac index and pulmonary capillary wedge pressure before and after the operation. Either LV end-diastolic volume index (from 134.8 +/- 30.7 to 77.1 +/- 16.3 ml/m2) or LV end-systolic volume index (from 85.0 +/- 21.8 to 40.0 +/- 12.5 ml/m2) definitely reduced postoperatively, the LV ejection fraction (EF), consequently, significantly improved from 0.31 +/- 0. 09 to 0.48 +/- 0.10 (p=0.0007). In all patients the New York Heart Association (NYHA) functional class improved from 2.8 +/- 0.7 to 1.3 +/- 0.5 after operation. We will aggressively employ this procedure for patients with ischemic cardiomyopathy in consideration of the limitations of the efficacy and the indication of this operation.

Polymethoxylated flavones in orange juice are inhibitors of P-glycoprotein but not cytochrome P450 3A4

The presence in orange juice of compounds that specifically inhibit the P-glycoprotein (P-gp) drug efflux transporter, but not the cytochrome P450 (CYP) isozyme CYP3A4, was investigated. The uptake of [(3)H]vinblastine, a substrate of P-gp, by Caco-2 cells was measured. An ethyl acetate extract of orange juice did not affect the initial uptake rate of [(3)H]vinblastine but significantly increased the steady-state uptake, as did cyclosporin A (20 microM), an inhibitor of P-gp. No significant effect on the uptake of 3-O-[(3)H]methylglucose or [(14)C]phenylalanine by Caco-2 cells was found, compared with the control. When the extract was separated on a Cosmosil column, the eluate with 70% methanol showed the most potent ability to increase [(3)H]vinblastine uptake. Additional separation of the 70% methanol eluate on a silica gel column with hexane-acetone (3:1) gave 3,3',4',5,6,7,8-heptamethoxyflavone (HMF) and 4',5,6,7,8-pentamethoxyflavone (tangeretin). HMF, tangeretin, and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin), another methoxyflavone contained in orange juice, all increased the steady-state uptake of [(3)H]vinblastine by Caco-2 cells in a concentration-dependent manner. The order of potency of these compounds at the concentration of 50 microM was tangeretin > HMF > nobiletin. None of these methoxyflavones inhibited 6beta-hydroxylation of testosterone catalyzed by CYP3A4. The ethyl acetate extract of orange juice and these methoxyflavones also increased steady-state [(3)H]vinblastine uptake by LLC-GA5-COL300 cells (a cell line transfected with human MDR1 cDNA). We conclude that these methoxyflavones enhanced vinblastine uptake by specifically inhibiting drug efflux via P-gp. They may have potential as agents for reversing multidrug resistance or for recovering the bioavailability of certain drugs.

Quantitative prediction of metabolic inhibition of midazolam by erythromycin, diltiazem, and verapamil in rats: implication of concentrative uptake of inhibitors into liver

To evaluate the degree of drug-drug interaction concerning metabolic inhibition in the liver quantitatively, we tried to predict the plasma concentration increasing ratio (R) of midazolam (MDZ) by erythromycin (EM), diltiazem (DLZ), or verapamil (VER) in rats. MDZ was administered through the portal vein at the steady state of plasma concentration of these inhibitors. The R values in the area under the plasma concentration curve of MDZ in the presence of EM, DLZ, and VER were 2.02, 1.64, and 1.30, respectively. The liver to plasma unbound concentration ratios of EM, DLZ, and VER at the steady state after infusion were 20.8, 1.02, and 3.01, respectively, suggesting concentrative uptake of EM and VER into the liver. The predicted R value in the presence of EM calculated by use of plasma unbound concentration was 1.03, whereas the value calculated with liver unbound concentration was 1.61, which was very close to the observed value. These findings indicated the need to consider the concentrative uptake of inhibitors into the liver for the quantitative prediction of metabolic inhibition. However, the predicted values in the presence of DLZ or VER calculated by use of liver unbound concentration were still underestimated. This result may be due to the metabolic inhibition by the metabolites of both inhibitors. Therefore, when predicting the degree of metabolic inhibition quantitatively, the inhibitory effect by coadministered drugs and the disposition of these metabolites in the liver must also be considered.

Relationship between time after intake of grapefruit juice and the effect on pharmacokinetics and pharmacodynamics of nisoldipine in healthy subjects

A clinical study was performed in eight healthy volunteers to investigate the effect of various timing of grapefruit juice intake on nisoldipine pharmacokinetics and pharmacodynamics, and to validate our pharmacokinetic model. The subjects were given 10 mg oral nisoldipine with water (control), or 5 mg oral nisoldipine with 200 mL grapefruit juice (G0) or with water at 14 (G14), 38 (G38), 72 (G72) or 96 hours (G96) after a 7-day period of thrice-daily intake of grapefruit juice. Grapefruit juice ingestion did not affect heart rate or the effect area during the first 8 hours of heart rate after nisoldipine administration, although significant decreases of systolic and diastolic blood pressure were caused in G0 by coadministration of grapefruit juice with nisoldipine. Headaches were reported by 3, 2, and 1 persons in G0, G14, and G38, respectively, but no subjects in G72 and G96 reported headaches. Compared with the control group, the maximum plasma concentration of nisoldipine was significantly increased after grapefruit juice intake in G0 and G14, and the plasma concentration was significantly increased at each time in G0 to G72. Therefore the effect of grapefruit juice decreased time dependently and lasted for at least 3 days after intake. Furthermore, our model gave predicted values in good agreement with the observed values. It is therefore necessary to withhold grapefruit juice for at least 3 days before administration of the drug to prevent grapefruit juice-nisoldipine interaction.

Invariant power law distribution of langevin systems with colored multiplicative noise

The random multiplicative process is studied for the case of a colored multiplicative noise with exponentially decreasing autocorrelation function. We observe the power law exponent of probability distribution in a statistically steady state numerically to clarify the effect of finite correlation time. The renormalization procedure is applied to derive the power law exponent theoretically. The power law exponent is inversely proportional to the autocorrelation time of the multiplicative noise.

Comparison of pathologic changes in Helicobacter pylori-infected Mongolian gerbils and humans

Helicobacter pylori has been recognized as a pathogen causing gastroduodenal disease, with adequate evidence to prove this relation in clinical research. Available animal models, however, were inadequate until 1995, when a new animal model of H. pylori infection was established using Mongolian gerbils. In this study we compared pathological changes in seven H. pylori-infected Mongolian gerbils with ulcers to five patients with gastric ulcer who underwent operation. All of the animals showed positive reactions for both H. pylori culture and serum anti-H. pylori antibody titer. All human subjects had H. pylori on the mucosal surface. Thus, inflammatory cell infiltration in the pyloric gland area was observed throughout almost all layers in the animals. In contrast, inflammation was observed in the surface layer of the mucosa in the pyloric gland area in the human subjects. Lymph follicle formation was observed more often in humans than in the animals. Inflammation of the fundic gland area in both groups was weaker than of the pyloric gland area and was observed within the mucosa. Histological changes observed in both groups were chronic active gastritis, lymph follicles, and intestinal metaplasia in the stomach. H. pylori-associated gastritis in humans is characterized by erosion, inflammation with neutrophil infiltration, lymph follicles, intestinal metaplasia, and atrophy. These findings are similar to those in this animal model. Thus, H. pylori infection might participate in the pathogenesis of gastroduodenal mucosal damage. In conclusion, the Mongolian gerbil is a good animal model for H. pylori-associated gastric diseases, and it might be useful for investigating the pathogenesis of H. pylori infection.

Beat-by-beat double-normalized pulse volume derived photoplethysmographically as a new quantitative index of finger vascular tone in humans

Near-infrared finger photoplethysmograms were recorded and double-normalized pulse volumes (DNPV = DeltaV(b)/V(b); V(b) = total blood volume in the fingertip, DeltaV(b) = pulsatile component of V(b)) were calculated in ten subjects during, immersion of the contralateral hand in water at three different temperatures (44 degrees C, 22 degrees C, 11 degrees C). The DNPV from the left finger was compared beat-by-beat with cutaneous vascular resistance (CVR) derived by dividing mean blood pressure of the left third finger by cutaneous blood flow of the left fourth finger. The correlations overall at the three temperatures between log DNPV(LF) and log CVR(LF) (LF, low frequency component of DNPV and CVR) ranged from -0.89 to -0.96 among the subjects. After adjusting for a maximal extension of the vascular wall (DNPV(max)), the correlations became stronger. It was concluded that DNPV was a reliable and valid indicator of vascular tone in the finger.

Pharmacokinetic analysis of felodipine-grapefruit juice interaction based on an irreversible enzyme inhibition model

Aims Ingestion of grapefruit juice (GFJ) alters the pharmacokinetics of various orally administered drugs. Quantitative evaluation of this GFJ-drug interaction is required for the proper clinical management of patients. Methods Using felodipine as a model drug, we constructed a pharmacokinetic model based on irreversible inhibition of intestinal cytochrome P450 3A4 (CYP3A4) by GFJ. We fitted previously published data [5, 6] for felodipine ER (extended release formulation) to the ratio of CLGI,int before and after grapefruit juice ingestion by nonlinear least-squares regression analysis to estimate the reaction rate constant between GFJ and CYP3A4 (K) and the elimination rate constant of CYP3A4 (k ).

RESULTS

The model gave a turnover rate of CYP3A4 of 0.0849 h-1, corresponding to a half-life of 8.16 h, in agreement with reported values. The AUC-time profiles of felodipine ER in the case of different amounts and schedules of GFJ ingestion were simulated using the parameter values estimated from the model.

CONCLUSIONS

The modelling leads to the important conclusion that GFJ-felodipine interaction increases with increasing frequency and amount of GFJ ingestion, and that an interval of 2-3 days between GFJ intake and felodipine administration is necessary if GFJ-felodipine interaction is to be avoided.

Intratumoral pyrimidine nucleoside phosphorylase (PyNPase) activity predicts a selective effect of adjuvant 5'-deoxy-5-fluorouridine (5'DFUR) on breast cancer

BACKGROUND

Pyrimidine nucleoside phosphorylase (PyNPase) is the enzyme that converts 5'-deoxy-5-fluorouracil (5'DFUR) to 5-fluorouracil (5FU). Its activity in cancer tissue may correlate with the selective antitumor activity of 5'DFUR in breast cancer.

METHODS

Two hundred and sixteen T2 breast cancer patients were treated consecutively with surgery followed by 5'DFUR (600 mg/body/day) + tamoxifen (20 mg/body/day) for 2 years. PyNPase activity in breast cancer tissue, determined by high-performance liquid chromatography, ranged from 4.2-626.0 micrograms FU/mg protein/hr (mean +/- SD, 203.5 +/- 122.4), and the examined patients were divided into two groups: group A (high PyNPase group), cases with the PyNPase activity equal to or more than the mean value of 203.5 micrograms FU/mg protein/hr, and group B (low PyNPase group), cases with activity less than the mean value.

RESULTS

Although there was no difference in relapse-free survival (RFS) between groups A and B, among node-positive patients (n = 83) those in group A tended to have a longer RFS. When divided into subgroups according to estrogen receptor (ER) status, among node-positive and ER-positive tumors (n = 49), the RFS was significantly better in group A than in group B (p < 0.05).

CONCLUSION

Intratumoral PyNPase activity might be of use as a predictor of the effect of adjuvant 5'DFUR on breast cancer.