4-(Benzoylindolizinyl)butyric acids; novel nonsteroidal inhibitors of steroid 5alpha-reductase. III

A novel series of indolizinebutyric acids with various benzoyl substituents was synthesized to develop nonsteroidal inhibitors of steroid 5alpha-reductase, and the structure-activity relationships in this series were studied. We previously reported the structure-activity relationships in a series of indolebutyric acids as well as the discovery of the novel nonsteroidal 5alpha-reductase inhibitor, FK143. We have now made other modifications to this compound to improve in vivo inhibitory activity. By altering the heterocyclic nucleus and changing the benzoyl substituent we have succeeded in identifying the strongly active compound, FK687, (S)-4-[1-[4-[[1-(4-isobutylphenyl)butyl]oxy]benzoyl]indolizin-3-yl]butyric acid, which displays strong in vitro inhibitory activity against the human enzyme and in vivo inhibitory activity against the castrated young rat model. This compound should be a useful agent for the treatment of benign prostatic hyperplasia.

Cell type proportioning in Dictyostelium slugs: lack of regulation within a 2.5-fold tolerance range

The proportion of prestalk and prespore cells in Dictyostelium discoideum slugs is often cited as an example of "almost perfect" regulation. The pattern is similar over a very wide range of cell number; furthermore, removal of either of the cell types leads to compensatory transdifferentiation. Several studies of Dictyostelium fruiting bodies, however, have suggested that proportioning in Dictyostelium differs systematically from true constancy. We have confirmed this in the slug stage using a short-lived beta-galactosidase as a reporter of the prestalk specific ecmA gene expression: the prestalk proportion decreases from 24+/-5% in slugs of 10(3) cells to 10+/-3% when 10(5) cells are present. Regeneration experiments suggest that this difference is not due to a modulation of the proportioning set-point by size, as one might have expected; instead there appears to be a regulatory "tolerance zone" at all sizes. After amputation of the whole posterior region, transdifferentiation stops after the fraction of prestalk has been reduced from 100% to 28+/-20%, well above the initial value of 10+/-3%, while after anterior removal the transdifferentiation endpoint is about 10%. Most strikingly, we find no regulation at all after partial amputations of the prespore region. It seems that any prestalk proportion is stable between a approximately 10% lower threshold and a approximately 30% upper threshold. To explain this, we propose a regulation mechanism based on a negative feedback plus cell type bistability. In both intact and regenerating slugs we find that the slug morphology is regulated so that the length-to-width ratio of the anterior region is constant.

Assessment of systemic adverse reactions induced by ophthalmic beta-adrenergic receptor antagonists

To assess quantitatively the risks of ophthalmic beta-blocking agents for cardiovascular and respiratory adverse reactions, we analyzed the binding kinetics of beta-blocking agents to the beta-1 and beta-2 adrenoceptors. The relationship between the occupancies for beta-1 and beta-2 adrenoceptors and the effects on the exercise pulse rate or the forced expiratory volume in one second (FEV1) after topical administration of carteolol, befunolol, timolol and betaxolol was analyzed using a ternary complex model. The beta-1 and beta-2 receptor occupancies after ophthalmic administration were calculated to be quite high as well as those after oral administration. The maximum occupancies for beta-1 and beta-2 receptors after ordinary ophthalmic administration were 52% and 88% for carteolol, 52% and 61% for befunolol, 62% and 82% for timolol, and 44% and 3% for betaxolol, respectively. Concave relationships were obtained between a decrease in exercise pulse rate and the beta-1 receptor occupancy and between a decrease in FEV1 and beta-2 receptor occupancy, respectively. Nasolacrimal occlusion was estimated to decrease the exercise pulse rate and FEV1 by 65% and 50%, respectively. The beta-1 and beta-2 adrenoceptor occupancies were proved to be the most appropriate indicators for cardiac and pulmonary adverse reactions evoked by ophthalmic beta-blocking agents.

A comparative pharmacodynamic study of the arrhythmogenicity of antidepressants, fluvoxamine and imipramine, in guinea pigs

Among several classes of antidepressants, tricyclic antidepressants are known to prolong QTc intervals (QT interval corrected by heart rate) in electrocardiograms, while selective serotonin uptake inhibitors (SSRI) are considered to be devoid of arrhythmogenicity. In this study, we aimed to compare the arrhythmogenic potencies of imipramine (IMI), a typical tricyclic antidepressant, and fluvoxamine (FLV), an SSRI, at therapeutic and supratherapeutic concentrations using guinea pigs in vivo. Guinea pigs were anesthetized, and IMI (10 and 20 mg/kg/h) or FLV (20 mg/kg/h) was intravenously administered for 90 minutes to obtain the time-courses of drug concentrations in plasma and the changes in the QTc intervals during and after the drug administration. IMI induced distinct QTc prolongation in a dose-dependent manner, while FLV prolonged QTc intervals only slightly. A pharmacokinetic-pharmacodynamic analysis revealed that the potency for QTc prolongation of IMI was 1.7-fold higher than that of FLV. Taking the therapeutic concentration into account, the clinical risk of FLV for QTc prolongation was suggested to be 5-fold lower than that of IMI. Therefore, this SSRI agent was suggested to be safer than the tricyclic antidepressant for patients with cardiac risk factors, including arrhythmia, or for those taking other arrhythmogenic drugs concomitantly.

Normalized pulse volume (NPV) derived photo-plethysmographically as a more valid measure of the finger vascular tone

Normalized pulse volume (NPV) was advocated as a more valid measure for the assessment of finger vascular tone. Based on the optical model in the finger tip expressed by Lambert--Beer's law, NPV is expressed as Delta I(a)/I. Here, Delta I(a) is the intensity of pulsatile component superimposed on the transmitted light (I). Theoretically, NPV seems to be superior to the conventional pulse volume (PV; corresponding to Delta I(a)). Firstly, NPV is in direct proportion to Delta V(a), which is the pulsatile component of the arterial blood volume, in a more exact manner. Relatedly, NPV can be processed as if it is an absolute value. Secondly, the sensitivity of NPV during stressful stimulations is expected to be higher. These expectations were supported experimentally using 13 male students. Firstly, the correlation between cutaneous vascular resistance in the finger tip (CVR) and NPV was higher than that between CVR and PV among all the subjects, although there was not much difference between these correlations within each subject. Secondly, NPV decreased much more than PV during mental stress. Some limitations of the present study were addressed, including the point that certain factors can violate the direct proportional relationship of NPV and PV to Delta V(a).

[Plication of the sinotubular junction for aneurysm of the ascending aorta associated with aortic regurgitation: a case report]

A 63-year-old woman with aneurysm of the ascending aorta associated with AR due to dilatation of the sinotubular junction (STJ) and with poor LV function, who did not have Marfan syndrome, underwent a plication of the STJ and replacement of the ascending aorta. In operation, we simultaneously performed the plication of dilated STJ (60 mm) and the replacement of ascending aorta using a 26 mm Woven Dacron graft. Post-operative angiogram (1 POM) showed no aortic regurgitation and good recovery of the LV function. This procedure is less invasive, and indicated for patients without significant elongation or thickening of the aortic valve, especially when the patients have higher risk.

Reconstruction of large nasal defects with a combination of local flaps based on the aesthetic subunit principle

Herein is described a technique that uses a combination of local flaps to reconstruct large defects involving the nasal dorsum and cheek. The flaps used are a transposition flap elevated from the area adjoining the defect and bilateral cheek advancement flaps. This technique leaves all suture wounds at borders of the aesthetic subunits that have been described previously. Color and texture matches were good and symmetrical. The transposition flap can be modified according to whether the defect includes the nasal tip. After raising the cheek advancement flap, it is also possible to use a dog-ear on the nasolabial region for any alar defects. Nine patients were treated using this procedure. The technique is very reliable (no complications such as congestion and skin necrosis in our series) and is easy to perform. One patient had palpebral ectropion after the operation and underwent secondary repair. In this series, defects measuring 45 x 30 mm in maximum diameter and including the nasal dorsum, nasal tip, ala, and cheek were treated.

Upregulatory Expression of Furin and Transforming Growth Factor-β by Fluid Shear Stress in Vascular Endothelial Cells

Abstract —Furin, a yeast Kex2-family endoprotease, converts many vasoregulatory propeptides, including pro-transforming growth factor (TGF)-β to their mature forms. We examined whether furin expression is regulated by shear stress in vivo and in vitro. When an arteriovenous shunt was placed between the carotid artery and external jugular vein in rabbits, furin and TGF-β were highly expressed in shear stress–loaded endothelial cells. Exposure of bovine aortic endothelial cells in culture to shear stress induced furin and TGF-β expression in a similar manner. Molecular analysis of furin expression in bovine aortic endothelial cells revealed that shear stress increases the furin gene expression at transcriptional levels. Furthermore, TGF-β itself increased the furin mRNA levels. Shear-mediated furin expression was partly mediated by TGF-β because shear-induced furin mRNA levels were considerably decreased by overexpression of the truncated form of the TGF-β type II receptor. Likewise, blockade of furin activity by a furin inhibitor significantly decreased the endothelial production of mature TGF-β. Taken together, the results indicate that furin expression is induced and maintained by a coordination of shear stress and TGF-β. Increased furin expression may facilitate the formation of mature TGF-β, resulting in the enhanced effects of TGF-β on endothelial cells and vascular smooth muscle cells in the vasculature.

Uptake mechanism of valproic acid in human placental choriocarcinoma cell line (BeWo)

Valproic acid is an anticonvulsant widely used for the treatment of epilepsy. However, valproic acid is known to show fetal toxicity, including teratogenicity. In the present study, to elucidate the mechanisms of valproic acid transport across the blood-placental barrier, we carried out transcellular transport and uptake experiments with human placental choriocarcinoma epithelial cells (BeWo cells) in culture. The permeability coefficient of [3H]valproic acid in BeWo cells for the apical-to-basolateral flux was greater than that for the opposite flux, suggesting a higher unidirectional transport in the fetal direction. The uptake of [3H]valproic acid from the apical side was temperature-dependent and enhanced under acidic pH. In the presence of 50 microM carbonyl cyanide p-trifluoromethoxylhydrazone, the uptake of [3H]valproic acid was significantly reduced. A metabolic inhibitor, 10 mM sodium azide, also significantly reduced the uptake of [3H]valproic acid. Therefore, valproic acid is actively transported in a pH-dependent manner on the brush-border membrane of BeWo cells. Kinetic analysis of valproic acid uptake revealed the involvement of a non-saturable component and a saturable component. The Michaelis constant for the saturable transport (K(t)) was smaller under acidic pH, suggesting a proton-linked active transport mechanism for valproic acid in BeWo cells. In the inhibitory experiments, some short-chain fatty acids, such as acetic acid, lactic acid, propanoic acid and butyric acid, and medium-chain fatty acids, such as hexanoic acid and octanoic acid, inhibited the uptake of [3H]valproic acid. The uptake of [3H]valproic acid was also significantly decreased in the presence of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, salicylic acid and furosemide, which are well-known inhibitors of the anion exchange system. Moreover, p-aminohippuric acid significantly reduced the uptake of [3H]valproic acid. These results suggest that an active transport mechanism for valproic acid exists on the brush-border membrane of placental trophoblast cells and operates in a proton-linked manner.

Prediction of midazolam-CYP3A inhibitors interaction in the human liver from in vivo/in vitro absorption, distribution, and metabolism data

The extent of decreases in apparent hepatic clearance and intrinsic hepatic clearance of midazolam (MDZ) after intravenous administration of MDZ with concomitant oral administration of cimetidine (CIM), itraconazole (ITZ), or erythromycin (EM) was predicted using plasma unbound concentrations and liver unbound concentrations of inhibitors. When MDZ was concomitantly administered with CIM, the observed increase in MDZ concentration was successfully predicted using inhibition constants assessed by human liver microsome and liver-to-plasma unbound concentration ratios in rats. However, the extent of interaction with ITZ or EM was still underestimated even taking into account the concentrative uptake of inhibitors into liver. We could predict the degree of "mechanism-based" inhibition by EM on the hepatic metabolism of MDZ, after repeated administration of EM, by a physiological model incorporating the amount of active enzyme as well as the concentration of inhibitor. The maximum inactivation rate constant and the apparent inactivation constant of EM on MDZ metabolism were 0.0665 min(-1) and 81.8 microM, respectively. These kinetic parameters for the inactivation of the enzyme were applied to the physiological model with pharmacokinetic parameters of EM and MDZ obtained from published results. Consequently, we estimated that cytochrome P450 3A4 in the liver after repeated oral administration of EM was inactivated, resulting in 2.6-fold increase in the plasma concentration of MDZ. The estimated extent of increase in MDZ concentration in our study correlated well with the observed value based on metabolic inhibition by EM from published results.

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.