Intestinal epithelial culture under an air-liquid interface: a tool for studying human and mouse esophagi

This study investigated whether an intestinal epithelial culture method can be applied to mouse and human esophageal cultures. The esophagi harvested from 1-day-old mice and adult humans were maintained in collagen gels. A commercially available culture medium for human embryonic stem cells was used for the human esophageal culture. We discovered that the intestinal epithelial culture method can be successfully applied to both mouse and human esophageal cultures. The long-term cultured esophageal organoids were rod-like luminal structures lined with myofibroblasts. We discovered that regeneration of the esophageal mucosal surface can be almost completely achieved in vitro, and the advantage of this method is that organoid cultures may be generated using host-derived fibroblasts as a niche. This method is a promising tool for mouse and human research in intestinal biology, carcinogenesis, and regenerative medicine.

Simultaneous optical mapping system of endocardial and epicardial excitation

The cardiac excitation propagation during arrhythmia shows a three-dimensional complex excitation behavior. Numerous optical measurements of the propagation and action potentials of the cardiac muscles have been made to elucidate the detailed arrhythmia phenomenon. The conventional optical measurement system mainly observes the action potential signal of the epicardium, and the endocardial signal measurement without incising the heart is difficult. In addition, an incised heart no longer exhibits the natural excitation behavior. Therefore, we constructed a simultaneous measurement system that integrates the conventional epicardial measurement system and the endocardial measurement system by using an endoscope for an intact heart. Then, we proposed a line-laser registration method that can match correspondence between the epicardial and endocardial images for a short period. We demonstrated that this registration method has a sub-millimeter accuracy. Subsequently, we succeeded in simultaneous optical measurement of the excitation propagation of the epicardium and endocardium of the right heart wall by using an isolated rabbit heart.

Design and fabrication of a perpendicular magnetic tunnel junction based nonvolatile programmable switch achieving 40% less area using shared-control transistor structure

A compact nonvolatile programmable switch (NVPS) using 90 nm CMOS technology together with perpendicular magnetic tunnel junction (p-MTJ) devices is fabricated for zero-standby-power field-programmable gate array. Because routing information does not change once it is programmed into an NVPS, high-speed read and write accesses are not required and a write-control transistor can be shared among all the NVPSs, which greatly simplifies structure of the NVPS. In fact, the effective area of the proposed NVPS is reduced by 40% compared to that of a conventional MTJ-based NVPS. The instant on/off behavior without external nonvolatile memory access is also demonstrated using the fabricated test chip.

Dose effects of oral estradiol on bone mineral density in Japanese women with osteoporosis

OBJECTIVES

This 2-year study compared 0.5 and 1.0 mg oral estradiol (E(2)), with or without levonorgestrel (LNG), for the treatment of postmenopausal osteoporosis in Japanese women.

METHODS

Japanese women with osteoporosis after natural menopause or bilateral oophorectomy were randomized to receive E(2) 0.5 or 1.0 mg/day with LNG 40 microg as required, or placebo, for 52 weeks. Women treated with E(2) in the first year continued therapy at the same doses in the second year. Efficacy, safety and pharmacokinetics were assessed.

RESULTS

There were 73 women randomized to E(2) 0.5 mg, 157 to E(2) 1.0 mg and 79 to placebo. Lumbar bone mineral density at 52 weeks increased significantly more with E(2) 1.0 mg (p < 0.001) and 0.5 mg (p < 0.001) than with placebo (no change). After 2 years, a 10% increase in bone mineral density with E(2) 1.0 mg was significantly greater than with E(2) 0.5 mg (8%; p = 0.008). E(2) was associated with an acceptable safety and tolerability profile, with slightly more adverse events with E(2) 1.0 than 0.5 mg. Serum E(2) concentration increased in a dose-dependent manner.

CONCLUSION

This study showed that E(2), at both 1.0 mg and 0.5 mg doses, was effective in increasing bone mineral density with an acceptable safety and tolerability profile in Japanese postmenopausal women with osteoporosis but that the bone mineral density response was higher with the 1.0 mg dose.

Association of renal artery stenosis with aortic jet velocity in hypertensive patients with aortic valve sclerosis

BACKGROUND

Patients with aortic valve sclerosis (AVS) have an increased risk of cardiovascular events. Patients with atherosclerotic renal artery stenosis (RAS) develop resistant hypertension and heart failure. We hypothesized AVS may be copresent with RAS in hypertensive patients.

METHODS

Hypertensive patients with AVS (n = 167) underwent magnetic resonance (MR) angiography using nonenhanced steady-state free precession (SSFP) technique. More than 75% luminal narrowing in the proximal region of main renal artery was regarded as significant RAS. Peak aortic jet velocity was obtained by Doppler echocardiography. We measured brain natriuretic peptide (BNP), and estimated glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease equation.

RESULTS

Unilateral or bilateral RAS was detected in 40 patients. AVS patients with RAS were older (78 +/- 6 vs. 74 +/- 8 years), and had higher levels of aortic jet velocity (162 +/- 4 vs. 144 +/- 3 cm/s), and lower levels of GFR (55 +/- 13 vs. 62 +/- 14 ml/min/1.73 m(2)) than those without RAS. Higher aortic jet velocity (odds ratio (OR) = 1.58, 95% confidence interval (CI) = 1.09-2.31) and lower GFR (OR = 0.54, 95% CI = 0.33-0.38) were associated with the presence of RAS, after being adjusted for age, systolic blood pressure, and BNP.

CONCLUSIONS

RAS was detected in hypertensive patients with AVS, particularly in patients with higher aortic jet velocity and lower GFR. Higher aortic jet velocity and lower GRF may be useful as a potential indicator for those needing assessment of RAS for risk stratification and deserves further study.

Incidence of Carboplatin-related hypersensitivity reactions in Japanese patients with gynecologic malignancies

Carboplatin is one of the most commonly used and well-tolerated agents for gynecologic malignancies. The rate of hypersensitivity reactions (HSRs) in the overall population of patients receiving carboplatin has been reported to increase after multiple doses of the agent. We retrospectively analyzed the incidence, clinical features, management, or outcome of carboplatin-related HSRs in 113 Japanese patients with gynecologic malignancies and the possibility of rechallenge with the drug. We intravenously administered carboplatin after paclitaxel or docetaxel. Mild HSRs are resolved by temporary interruption of carboplatin infusion, an additional antihistamine, and/or a corticosteroid. If HSRs arose, carboplatin was diluted, not exceeding 1 mg/mL, and slowly infused over 2 hours in subsequent cycles. Ten patients experienced carboplatin HSRs, with an overall incidence of 8.85%. The first HSR episode was mild in all cases. When retreated with carboplatin, 4 exhibited severe HSRs. More than 9 cycles and/or more than 5000 mg of carboplatin administration significantly increased the incidence of HSRs. In particular, carboplatin treatment beyond 15 cycles and/or 8000 mg increased the risk of severe HSRs (P < 0.0001). The incidence of HSRs in the ovarian carcinoma group was significantly greater than that in the uterine carcinoma group (P = 0.0046). Careful attention should be paid to HSRs during carboplatin treatment beyond 9 cycles and/or 5000 mg. The rate of severe HSRs greatly increases beyond 15 cycles and/or 8000 mg. Further studies are needed to identify potential risk factors that may contribute to the development of carboplatin HSRs and to decrease the risk of reactions.

Role of Ca2+ mobilization and Ca2+ sensitization in 8-iso-PGF 2 alpha-induced contraction in airway smooth muscle

BACKGROUND

Isoprostanes are prostaglandin (PG)-like compounds synthesized by oxidative stress, not by cyclooxygenase, and increase in bronchoalveolar lavage fluid of patients with asthma. The airway inflammation implicated in this disease may be amplified by oxidants. Although isoprostanes are useful biomarkers for oxidative stress, the action of these agents on airways has not been fully elucidated.

OBJECTIVE

This study was designed to determine the intracellular mechanisms underlying the effects of oxidative stress on airway smooth muscle, focused on Ca(2+) signalling pathways involved in the effect of 8-iso-PGF(2 alpha).

METHODS

Using simultaneous recording of isometric tension and F(340)/F(380) (an indicator of intracellular concentrations of Ca(2+), [Ca(2+)]i, we examined the correlation between tension and [Ca(2+)]i in response to 8-iso-PGF(2 alpha) in the fura-2 loaded tracheal smooth muscle.

RESULTS

Augmented tension and F(340)/F(380) by 8-iso-PGF(2 alpha) were attenuated by ICI-192605, an antagonist of thromboxane A(2) receptors (TP receptors). Moreover, D609, an antagonist of phosphatidylcholine-specific phospholipase C, markedly reduced both the tension and F(340)/F(380) induced by 8-iso-PGF(2 alpha), whereas U73122, an antagonist of phosphatidylinositol-specific phospholipase C, modestly inhibited them by 8-iso-PGF(2 alpha). SKF96365, a non-selective antagonist of Ca(2+) channels, markedly reduced both tension and F(340)/F(380) by 8-iso-PGF(2 alpha). However, diltiazem and verapamil, voltage-dependent Ca(2+) channel inhibitors, modestly attenuated tension although their reduction of F(340)/F(380) was not different from that by SKF96365. Y-27632, an inhibitor of Rho-kinase, significantly attenuated contraction induced by 8-iso-PGF(2 alpha) without reducing F(340)/F(380), whereas GF109203X and Go6983, protein kinase C inhibitors, did not markedly antagonize them although reducing F(340)/F(380) with a potency similar to Y-27632.

CONCLUSION

8-iso-PGF(2 alpha) causes airway smooth muscle contraction via activation of TP receptors. Ca(2+) mobilization by SKF96365- and D609-sensitive Ca(2+) influx and Ca(2+) sensitization by Rho-kinase contribute to the intracellular mechanisms underlying the action of 8-iso-PGF(2 alpha). Rho-kinase may be a therapeutic target for the physiologic abnormalities induced by oxidative stress in airways.

Neoadjuvant chemotherapy with weekly carboplatin and paclitaxel for locally advanced cervical carcinoma

The efficacy and toxicity of neoadjuvant carboplatin and paclitaxel administered on a weekly schedule for locally advanced cervical carcinoma were evaluated. Thirty patients staged as IB2-IVA according to the FIGO were treated with carboplatin (AUC 2; an area under the time-concentration of 2 mg*min/ml based on creatinine clearance) and paclitaxel (60 mg/m(2)) intravenously, every week for six cycles. A type III radical hysterectomy was then undertaken. Thirty patients were enrolled in this study. An objective response was recorded in 26 patients (87%, 95% CI 70-95%). Progressive disease was not observed. Grade 3 neutropenia was observed in only two patients (7%), and grade 1 or 2 neuropathy was seen in six patients (20%). The combination of carboplatin and paclitaxel given in weekly schedule for advanced cervical carcinoma was highly active, permitting a high rate of subsequent surgical resectability. It was well tolerated. This regimen may provide improved outcomes with minimal toxicity.

Roles of P2X receptors and Ca2+ sensitization in extracellular adenosine triphosphate-induced hyperresponsiveness in airway smooth muscle

BACKGROUND

The release of adenosine triphosphate (ATP) from the airway epithelial cells during the inflammatory process is considered to play an important role in the pathophysiology of asthma and chronic obstructive pulmonary disease.

OBJECTIVE

This study was designed to determine whether extracellular ATP is involved in the bronchial hyperresponsiveness as an interaction between epithelium and smooth muscle in the airways.

METHODS

We examined the contractile response to methacholine (MCh) before and after exposure to low concentrations (< or = 10 microm) of ATP in isolated, epithelium-denuded guinea-pig tracheal smooth muscle by measuring isometric tension. Intracellular Ca2+ concentrations ([Ca2+]i) were assessed by fluorescent intensities of fura-2.

RESULTS

MCh-induced contractile force was increased with no change in [Ca2+]i after exposure to 10 microm ATP for 15 min. The ability of ATP to enhance the MCh-induced contraction was markedly attenuated by suramin, a non-selective P2 receptor inhibitor. Pre-incubation with ATPgammaS, a non-hydrolysable analogue of ATP and alpha,beta-meATP, a P2X agonist, also enhanced the MCh-induced contraction. In contrast, uracil triphosphate, a P2Y agonist, did not affect the MCh-induced contraction. Y-27632, a Rho-kinase inhibitor, suppressed the ability of ATP to enhance the MCh-induced contraction. Moreover, PP1 and PP2, Src tyrosin kinase inhibitors, suppressed the enhancement of MCh-induced contraction by ATP.

CONCLUSION

Pre-treatment with ATP induces hyperresponsiveness to MCh mediated by Ca2+ sensitization via the P2X receptor in airway smooth muscle. The present findings suggest the possible involvement of both the Rho-kinase and Src pathways in the intracellular mechanism of this phenomenon.

Predictive value of heart-type fatty acid-binding protein for left ventricular remodelling and clinical outcome of hypertensive patients with mild-to-moderate aortic valve diseases

Heart-type fatty acid-binding protein (H-FABP), a marker of acute myocardial infarction and a soluble cytosolic protein, may be released following left ventricular remodelling in cardiac overloaded hearts caused by hypertension, aortic regurgitation (AR) or aortic stenosis (AS). Our aim was to investigate if H-FABP levels are associated with left ventricular remodelling and clinical outcome in hypertensive patients with AR or AS. H-FABP and brain natriuretic peptide (BNP) were measured, glomerular filtration rate (GFR) was estimated using the modification of diet in renal disease (MDRD) equation, and left ventricular dimension at systole corrected for body surface area (LVDs/BSA) and relative wall thickness (RWT) were determined by echocardiography in hypertensive patients with mild-to-moderate AR (n=78), those with mild-to-moderate AS (n=73) and those without valvular heart diseases (HT) (n=50). H-FABP levels were significantly higher in AR (4.9+/-3 ng/ml) and in AS (4.5+/-3) than in HT (3.4+/-1) and BNP (65+/-73 pg/ml, 76+/-75, 35+/-22). H-FABP correlated with LVDs/BSA in AR (beta=0.23, P<0.05), and RWT in AS (beta=0.18, P<0.05) after adjustment for age, gender and all the other variables. AS and AR patients were prospectively followed up for cardiac events during 34+/-19 months. A multivariate Cox hazard analysis indicated H-FABP was an independent predictor of outcome both in AR (relative risk (RR)=7.61, 95% CI=2.39-25.3) and AS (RR=13.6, 95% CI=3.27-66.9). H-FABP, associated with left ventricular remodelling, is useful in predicting clinical outcome in hypertensive patients with mild-to-moderate aortic valve diseases.

Analysis of QT Interval Prolongation With Heart Failure by Simulation of Repolarization Process

It has been postulated that action potential duration (APD) is prolonged and I<inf>Ks</inf>, a slow component of delayed rectifier potassium current, decreases in heart failure. We have reported that QT interval is prolonged and expression weight of KCNE1, coding I<inf>Ks</inf>channel, increases in patients with heart failure. Since it is known that increase in KCNE1 increases the maximum conductance of I<inf>Ks</inf>channel, the mechanism of APD prolongation is not explained by over expression of KCNE1. In this study, we construct a cardiac membrane action potential simulation model based on the experimental data from Xenopus oocytes expressed KCNQ1 and KCNE1 to investigate the relationship between increase in KCNE1 and APD. In addition, we investigated effect of reduction in Ca²⁺-independent transient outward potassium current (I<inf>to</inf>) on APD in heart failure. In simulation, APD at 5ng KCNE1 was 180.96ms, which was 4.63% longer than that at 1ng KCNE1 (APD=172.96ms) and 55.9% longer than that at 0.2ng KCNE1 (APD=110.96ms. In the cases of KCNQ1 alone and 0.2ng KCNE1 coinjected, APD shortened as density of I<inf>to</inf>decreased, and APD prolonged as density of I<inf>to</inf>decreased in other cases. This study shows that increase in KCNE1 expression level makes maximum conductance of I<inf>Ks</inf>channel increase and I<inf>Ks</inf>channel open slowly and conductance of I<inf>Ks</inf>channel decrease according to the APD time scale. Therefore increasing the KCNE1 expression level may prolong APD with this mechanism. This method of constructing a simulation model based on experiments helps to explain the relationship between potassium currents and QT interval prolongation.

Involvement of reduced sensitivity to Ca in beta-adrenergic action on airway smooth muscle

BACKGROUND

It is well known that beta-adrenoceptor agonists (beta-agonists) cause relaxation in airway smooth muscle mediated by a reduction in the concentration of intracellular Ca2+ ([Ca2+](i)). However, little is currently known regarding whether reduced sensitization to Ca2+ is involved in the beta-adrenergic relaxation.

OBJECTIVE

This study was designed to determine the intracellular mechanisms underlying suppression of Ca2+ sensitization in beta-adrenergic relaxation (Ca(2+)-independent relaxation by beta-agonists). Methods Isometric tension and [Ca2+](i) were simultaneously measured in fura-2-loaded strips isolated from guinea-pig tracheal smooth muscles. The relationships between tension and [Ca2+](i) were examined in the inhibitory action of isoprenaline (ISO) and other cAMP-related agents against methacholine-induced contraction.

RESULTS

The concentration-inhibition curve for ISO against methacholine in tension was significantly dissociated from the curve for ISO in [Ca2+](i). In ISO-induced relaxation, a reduction in tension was significantly greater than that in [Ca2+](i.) This phenomenon was mimicked by other cAMP-related agents: forskolin and dibutyryl-cAMP. In contrast, the inhibitory action of SKF-96365, a non-selective inhibitor of Ca(2+) channels, was associated with that in [Ca2+](i). In the presence of Rp-cAMPS, an inhibitor of protein kinase A (PKA), ISO caused an equivalent relaxation with less reduction in [Ca2+](i). The effects of ISO were not affected by Y-27632, an inhibitor of Rho-kinase, or by bisindolylmaleimide, an inhibitor of protein kinase C. ISO failed to inhibit contraction elicited by calyculin A, an inhibitor of myosin phosphatase. Conclusion beta-Adrenergic action antagonizes not only Ca2+ mobilization but also Ca2+ sensitization in methacholine-induced contraction. The cAMP/PKA-independent, G(s)-direct action is more potent in Ca(2+)-independent relaxation by beta-agonists than the cAMP/PKA-dependent pathway. Moreover, myosin phosphatase is a fundamentally affected protein in the reduced response to Ca2+ mediated by beta-agonist. Our results may provide evidence that this Ca2+ desensitization is a novel target for a reliever medication using rapid-acting beta-agonists in acute asthma management.

Acute cholecystitis due to strangulation of a floating gallbladder by the lesser omentum

We report a unique case of acute cholecystitis due to strangulation of a floating gallbladder by the lesser omentum, which could be detected by abdominal ultrasonography. We believe this case to be the first case of reported literatures in English.

Case control study of hormone replacement therapy (HRT) and breast cancer in Japanese women

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Background: Some prospective studies in US and UK (represented by Women’s Health Initiative and Million Women Study) show that HRT use may increase the risk of breast cancer. However, it is unclear whether or not this perspective is applicable to Japanese women, due to several factors such as the difference in incidence of breast cancer, difference in HRT prevalence, which are to be concerned in this study. To investigate the relationship between HRT use and breast cancer, a case-control study was conducted in Japan. Methods: We sent self-administered questionnaire to 4,500 cases who have a previous history of confirmed histological breast cancer and 4,500 controls who were selected according to the inclusion criteria. All the subjects were between age 45 and 69 at the time of enrollment. Among these subjects, 3,434 in case group and 2,427 in control group sent back their questionnaire (total 5,861). The datacenter was run in Kitasato Univ. and the statistical analysis was performed using SAS (version 9.1). Control was selected by considering the screening record for GI disease and respiratory disorders, with no previous history of breast cancer, gynecological and hormonal disease at the time of screening. We asked about past history of exposure to the factors supposed to be breast cancer-causing; previous or current use of HRT, age at diagnosis, academic background, BMI, lifestyle habits, age of menarche, birth history, history of breast feeding, family history, use of contraceptive agents and menopausal status. Results: As the main analysis result, 164 (5.0%) out of 3,316 cases and 253 (7.4%) out of 2355 controls had used HRT (Odds ratio 0.432 [95% CI 0.352–0.530]. Conclusions: The result of this study shows that HRT users were less likely to develop breast cancer than never users. However, in this study, there was a difference in the observation period for the past use of HRT between cases and controls. Considering the transition of HRT prevalence in Japan, there may be a possibility that this difference can be a cause of a serious bias for the main analysis result. Further sensitivity analyses are needed to evaluate the robustness of the findings and this point is under consideration.

No significant financial relationships to disclose.

Connexins in the sinoatrial and atrioventricular nodes

The sinoatrial node (SAN) and the atrioventricular node (AVN) are specialized tissues in the heart: the SAN is specialized for pacemaking (it is the pacemaker of the heart), whereas the AVN is specialized for slow conduction of the action potential (to introduce a delay between atrial and ventricular activation during the cardiac cycle). These functions have special requirements regarding electrical coupling and, therefore, expression of connexin isoforms. Electrical coupling in the center of the SAN should be weak to protect it from the inhibitory electrotonic influence of the more hyperpolarized non-pacemaking atrial muscle surrounding the SAN. However, for the SAN to be able to drive the atrial muscle, electrical coupling should be strong in the periphery of the SAN. Consistent with this, in the center of the SAN there is no expression of Cx43 (the principal connexin of the working myocardium) and little expression of Cx40, but there is expression of Cx45 and Cx30.2, whereas in the periphery of the SAN Cx43 as well Cx45 is expressed. In the AVN, there is a similar pattern of expression of connexins as in the center of the SAN and this is likely to be in large part responsible for the slow conduction of the action potential.

Computer three-dimensional reconstruction of the sinoatrial node

BACKGROUND

There is an effort to build an anatomically and biophysically detailed virtual heart, and, although there are models for the atria and ventricles, there is no model for the sinoatrial node (SAN). For the SAN to show pacemaking and drive atrial muscle, theoretically, there should be a gradient in electrical coupling from the center to the periphery of the SAN and an interdigitation of SAN and atrial cells at the periphery. Any model should include such features.

METHODS AND RESULTS

Staining of rabbit SAN preparations for histology, middle neurofilament, atrial natriuretic peptide, and connexin (Cx) 43 revealed multiple cell types within and around the SAN (SAN and atrial cells, fibroblasts, and adipocytes). In contrast to atrial cells, all SAN cells expressed middle neurofilament (but not atrial natriuretic peptide) mRNA and protein. However, 2 distinct SAN cell types were observed: cells in the center (leading pacemaker site) were small, were organized in a mesh, and did not express Cx43. In contrast, cells in the periphery (exit pathway from the SAN) were large, were arranged predominantly in parallel, often expressed Cx43, and were mixed with atrial cells. An approximately 2.5-million-element array model of the SAN and surrounding atrium, incorporating all cell types, was constructed.

CONCLUSIONS

For the first time, a 3D anatomically detailed mathematical model of the SAN has been constructed, and this shows the presence of a specialized interface between the SAN and atrial muscle.

A novel detection method for 2'-deoxyoxanosine

2'-Deoxyoxanosine (dOxo) is a novel DNA lesion produced from 2'-deoxyguanosine by the treatment with nitrous acid and nitric oxide. However, there has been no direct evidence on the formation of dOxo in vivo so far. In order to detect dOxo in vivo, we have explored a sensitive detection method specific for dOxo by using a fluorescent labeling reagent and HPLC analysis. An efficient method to detect the dOxo formation in DNA is described.

Expression of nuclear factor of activated T cells mRNA in maternal peripheral blood cells

PROBLEM

In T lymphocytes, nuclear factor of activated T cells (NF-AT) regulates the induction of cytokine genes upon antigenic stimulation. This study was designed to analyse the relationship between NF-AT and pregnancy.

METHOD OF STUDY

With informed consent, peripheral blood cells (PBCs) were obtained from non-pregnant (n = 114), pregnant (n = 604), and puerperal women (n = 52). The expression of NF-AT2 and NF-AT3 mRNAs in PBCs was measured by a quantitative reverse transcriptase-polymerase chain reaction method.

RESULTS

In the early pregnancy period, in successful pregnancy, both NF-AT2 and NF-AT3 mRNAs increased significantly, whereas in cases of spontaneous abortion they did not change significantly. After peaking, they decreased gradually and were re-elevated in the ninth and tenth gestational month. In the puerperal period, NF-AT3 mRNAs decreased, but NF-AT2 mRNA showed a comparatively high expression level.

CONCLUSION

These findings suggested that in humans NF-AT signal transduction might be involved in alloantigenic recognition and tolerance and play important roles, especially in the early and late period of pregnancy.

Sarcoplasmic reticulum Ca2+ release is not a dominating factor in sinoatrial node pacemaker activity

Recent work on isolated sinoatrial node cells from rabbit has suggested that sarcoplasmic reticulum Ca2+ release plays a dominant role in the pacemaker potential, and ryanodine at a high concentration (30 micromol/L blocks sarcoplasmic reticulum Ca2+ release) abolishes pacemaking and at a lower concentration abolishes the chronotropic effect of beta-adrenergic stimulation. The aim of the present study was to test this hypothesis in the intact sinoatrial node of the rabbit. Spontaneous activity and the pattern of activation were recorded using a grid of 120 pairs of extracellular electrodes. Ryanodine 30 micromol/L did not abolish spontaneous activity or shift the position of the leading pacemaker site, although it slowed the spontaneous rate by 18.9+/-2.5% (n=6). After ryanodine treatment, beta-adrenergic stimulation still resulted in a substantial chronotropic effect (0.3 micromol/L isoproterenol increased spontaneous rate by 52.6+/-10.5%, n=5). In isolated sinoatrial node cells from rabbit, 30 micromol/L ryanodine slowed spontaneous rate by 21.5+/-2.6% (n=13). It is concluded that sarcoplasmic reticulum Ca2+ release does not play a dominating role in pacemaking in the sinoatrial node. The full text of this article is available at http://www.circresaha.org.

Endometriosis: the pathophysiology as an estrogen-dependent disease

Endometriosis, defined as the presence of endometrial glands and stroma outside of the uterine cavity, develops mostly in women of reproductive age and regresses after menopause or ovariectomy, suggesting that the growth is estrogen-dependent. Indeed, the lesions contain estrogen receptors (ER) as well as aromatase, an enzyme that catalyses the conversion of androgens to estrogens, suggesting that local estrogen production may stimulate the growth of lesions. The expression patterns of ER and progesterone receptors in endometriotic lesions are different from those in the eutopic endometrium. Moreover, estrogen metabolism, including the expression pattern of aromatase and the regulation of 17 beta-hydroxysteroid dehydrogenase type 2 (an enzyme responsible for the inactivation of estradiol to estrone), is altered in the eutopic endometrium of women with endometriosis, adenomyosis, and/or leiomyomas compared to that in the eutopic endometrium of women without disease. Immunostaining for P450arom in endometrial biopsy specimens diagnosed these diseases with sensitivity and specificity of 91 and 100%, respectively. This is applicable to the clinical diagnosis of endometriosis. The polymorphisms in the ER-alpha gene, the CYP19 gene encoding aromatase, and several other genes are associated with the risk of endometriosis. Studies of these will lead to better understandings of the etiology and pathophysiology of endometriosis.

Postmenopausal hormone replacement therapy use and risk of endometrial cancer in Japanese women

The relationship between the risk of endometrial cancer and the use of noncontraceptive estrogens by Japanese postmenopausal women was investigated in a hospital-based case-control study of 1025 women with endometrial cancer and 1267 with other conditions. The overall odds ratio (OR) for estrogen use with or without progestins, compared with never use of any type of estrogens, was 0.917 (95% confidence interval (CI) 0.622-1.353), suggesting that hormone replacement therapy is not a causative agent for endometrial cancer in Japanese women, and that a recent increase in the incidence of endometrial cancer in Japanese women may be related to changes in their life-style. However, although not statistically significant, women who used estrogen without progestin for 12 or more months had an OR of 2.552 (CI 0.231-28.192), while those who used estrogen with progestin for 12 or more months had an OR of 0.425 (CI 0.086-2.113). These results indicate that the addition of a progestin should be considered for reducing the risk of endometrial cancer in Japanese women.

Distribution of the muscarinic K+ channel proteins Kir3.1 and Kir3.4 in the ventricle, atrium, and sinoatrial node of heart

The functionally important effects on the heart of ACh released from vagal nerves are principally mediated by the muscarinic K+ channel. The aim of this study was to determine the abundance and cellular location of the muscarinic K+ channel subunits Kir3.1 and Kir3.4 in different regions of heart. Western blotting showed a very low abundance of Kir3.1 in rat ventricle, although Kir3.1 was undetectable in guinea pig and ferret ventricle. Although immunofluorescence on tissue sections showed no labeling of Kir3.1 in rat, guinea pig, and ferret ventricle and Kir3.4 in rat ventricle, immunofluorescence on single ventricular cells from rat showed labeling in t-tubules of both Kir3.1 and Kir3.4. Kir3.1 was abundant in the atrium of the three species, as shown by Western blotting and immunofluorescence, and Kir3.4 was abundant in the atrium of rat, as shown by immunofluorescence. Immunofluorescence showed Kir3.1 expression in SA node from the three species and Kir3.4 expression in the SA node from rat. The muscarinic K+ channel is activated by ACh via the m2 muscarinic receptor and, in atrium and SA node from ferret, Kir3.1 labeling was co-localized with m2 muscarinic receptor labeling throughout the outer cell membrane.

Heterogeneous expression of the delayed-rectifier K+ currents i(K,r) and i(K,s) in rabbit sinoatrial node cells

1. The electrical activity of sinoatrial node cells is heterogeneous. To understand the reasons for this, the density of the delayed-rectifier K+ current and its two components, i(K,r) and i(K,s), as a function of the size (as measured by cell capacitance) of rabbit sinoatrial node cells was investigated using the whole-cell voltage-clamp technique at 35 degrees C. 2. i(K,r) and i(K,s) were isolated using E-4031 and 293B. Features of the E-4031-sensitive and 293B-insensitive currents corresponded well to those of i(K,r), while features of the E-4031-insensitive and 293B-sensitive currents corresponded well to those of i(K,s). 3. The densities of the outward current under control conditions and the drug-sensitive and -insensitive currents were significantly (P < 0.01) correlated with cell capacitance, with current densities being greater in larger cells. 4. The effects of partial blockade of i(K,r) by 0.1 microM E-4031 on spontaneous action potentials were greater in smaller cells. 5. It is concluded that there are cell size-dependent differences in the density of the i(K,r) and i(K,s) components, and these may be involved in the heterogeneity of the electrical activity of single sinoatrial node cells as well as that of the intact sinoatrial node.

Immunohistochemical localization of aromatase and apoptosis-associated proteins in ovarian serous cystadenocarcinoma arising from ovarian endometriosis

An immunohistochemical study was made of a case of serous cystadenocarcinoma that had been shown to have arisen from ovarian endometriosis. Aromatase cytochrome P450 (P450arom), an enzyme responsible for estrogen biosynthesis, was localized in the epithelial linings of the endometriosis and faintly in the transitional part, whereas it was not expressed in the carcinoma tissue. In contrast, estrogen receptors, progesterone receptors, and apoptosis-associated proteins, Fas, Fas ligand, and Bax were expressed in both endometriosis and carcinoma tissues of the tumor, whereas Bcl-2 was not expressed in either tissue of the tumor. It was suggested that the undifferentiated shift of the histologic grade might result in the loss of P450arom and that the malignant transformation was not caused by an altered balance of apoptosis-associated proteins. Accumulation of these studies may lead to a better understanding of the nature of malignant transformation of ovarian endometriosis.

Identification of 16alpha,19-dihydroxyandrostenedione in the serum of pregnant women by gas chromatography-mass spectrometry

16alpha,19-Dihydroxyandrostenedione [16alpha,19-(OH)2 AD], a potential precursor of estriol, was identified in the serum of pregnant women by gas chromatography-mass spectrometry (GC-MS). Preliminary study indicated that the average serum concentration of 16alpha,19-(OH)2 AD in 10 normal pregnant women was 154.2+/-20 pg/ml. In contrast, the serum concentration of 16alpha,19-dihydroxydehydroepiandrosterone was less than the detection limit (30 pg/mI) of the GC-MS method.

Estrogen protects neuronal cells from amyloid beta-induced apoptotic cell death

Accumulating studies have shown that estrogen replacement therapy reduces the risk of Alzheimer's disease. In this study, we clarified that 17beta-estradiol (E2) significantly rescues PC12 neuronal cells from amyloid beta protein (Abeta)-induced cell death. We found that the amino acid residues of 25 to 35 (Abeta25-35) were more cytotoxic than the full length protein (Abeta1-40) and these residues induced DNA fragmentation typical for apopto- sis. In addition, E2 was confirmed to inhibit calcium influx and cytochrome c release induced by Abeta25-35. Since these sequential events cause apoptosis, the protective effect of E2 may be exerted not by the direct interaction with Abeta, but by the blockade of the mitochondrial apoptotic pathway induced by Abeta.

Two small intrahepatic cholangiocarcinomas with different sonographic appearances

We report on 2 cases of small intrahepatic (or peripheral) cholangiocarcinomas initially detected by sonography and completely resected. The lesions had a peripheral hypoechoic component and a central isoechoic or hyperechoic component. One had posterior acoustic shadowing on sonography, and the other did not. Comparison with pathologic findings in both cases indicated that severe fibrotic changes may have caused the posterior acoustic shadowing. This finding is extremely rare. We found only 1 previously reported case of cholangiocarcinoma accompanied by acoustic shadowing.

Possible involvement of Rho kinase in Ca2+ sensitization and mobilization by MCh in tracheal smooth muscle

We examined the effects of Rho kinase on contraction and intracellular Ca2+ concentration ([Ca2+](i)) in guinea pig trachealis by measuring isometric force and the fura 2 signal [340- to 380-nm fluorescence ratio (F340/F380)]. A Rho kinase inhibitor, Y-27632 (1-1,000 microM), inhibited methacholine (MCh)-induced contraction, with a reduction in F340/F380 in a concentration-dependent manner. The values of EC(50) for contraction and F340/F380 induced by 1 microM MCh with Y-27632 were 27.3 +/- 5.1 and 524.1 +/- 31.0 microM, respectively. With 0.1 microM MCh, the values for these parameters were decreased to 1.0 +/- 0.1 and 98.2 +/- 6.2 microM, respectively. Tension-F340/F380 curves for MCh indicated that Y-27632 caused an ~50% inhibition of MCh-induced contraction, without a reduction in F340/F380. These effects of Y-27632 were not inhibited by a protein kinase C inhibitor, GF-109203X. Our results indicate that inhibition of Rho kinase attenuates both Ca2+ sensitization and [Ca2+](i).

Progesterone inhibition of functional leptin receptor mRNA expression in human endometrium

Leptin is secreted by adipocytes and regulates appetite through interaction with hypothalamic leptin receptors (OB-R). Leptin is involved in the stimulation of reproductive functions, and local expression of leptin and OB-R in the ovary, oocyte, embryo, and placenta might play a role in early development. The mRNA and protein of the long form leptin receptor (OB-R(L)) but not of leptin are expressed in the human endometrium and the abundance of OB-R mRNA expression varies during the menstrual cycle with a peak in the early secretory phase. We examined the steroidal regulation of OB-R(L) mRNA expression. Northern blot analyses showed that in organ-cultured proliferative endometrial specimens, oestradiol (10(-9) and 10(-8) mol/l) had no acute effect on the OB-R(L) mRNA expression, whereas oestradiol plus progesterone (10(-8), 10(-7) and 10(-6) mol/l) or medroxyprogesterone acetate (10(-8) and 10(-7) mol/l) suppressed the expression by approximately 50%. This progestin-induced suppression was blocked by a concomitant addition of mifepristone. Additionally, incubation of endometrial specimens in the presence of leptin resulted in the phosphorylation of its intracellular target, STAT3 (signal transducer and activator of transcription 3). These results indicate that, in the human endometrium, progestins act via the progesterone receptors to suppress functional OB-R(L) mRNA expression, and may thereby alter the sensitivity of the endometrium to leptin.

Localization of interferon regulatory factor-1 in human endometrium throughout the menstrual cycle

OBJECTIVE

To determine the expression and localization of IRF-1 in human endometrium throughout the menstrual cycle.

DESIGN

A comparative study.

SETTING

Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine.

PATIENTS

Thirty-eight women aged 33 to 46 years, with regular menstrual cycles and nonpathological endometrium, undergoing hysterectomy.

INTERVENTION(S)

Endometrial tissues were obtained from operative samples.

MAIN OUTCOME MEASURE(S)

Expression of IRF-1 mRNA throughout the menstrual cycle was investigated using semiquantitative reverse transcription-polymerase chain reaction. Localization of IRF-1 protein was determined using immunohistochemistry.

RESULT(S)

IRF-1 mRNA was expressed in the human endometrium at each phase of the menstrual cycle. The immunoreactivity for IRF-1 was observed in the extranuclear compartment of the surface and glandular epithelial cells, both during the proliferative and secretory phases, as well as in the gland secretion during the secretory phase. In contrast, stromal cells were nearly unstained.

CONCLUSION(S)

IRF-1 was localized in the human endometrium, implying that this nuclear protein plays some role other than as a transcription factor.

Prognostic value of thymidine phosphorylase immunostaining in patients with uterine cervical cancer treated concurrently with doxifluridine, radiotherapy and immunotherapy

Thymidine phosphorylase (dThdPase) is reportedly identical to platelet-derived endothelial cell growth factor (PD-ECGF). We conducted immunohistochemical staining of dThdPase to assess correlation between its expression in cancer tissue and efficacy of a combination therapy with 5'-DFUR, radiotherapy and sizofilan (SPG) in uterine cervical cancer patients. No difference in response rates was observed between dThdPase positive and negative tumor and stromal cells. Survival curves significantly differed between stromal dThdPase positive and negative groups (p=0.032). Results showed that dThdPase immunostaining is possibly prognostic and predictive in determining success of the combination therapy.

Pacemaker shift in the rabbit sinoatrial node in response to vagal nerve stimulation

Effects of brief postganglionic vagal nerve stimulation on the activation sequence of the rabbit sinoatrial (SA) node were investigated. Activation sequences in a small area (7 mm x 7 mm) on the epicardial surface were measured in a beat-to-beat manner using an extracellular potential mapping system composed of 64 modified bipolar electrodes with high-gain and low-frequency band-pass filtering. The leading pacemaker site was recognised clearly from both the activation sequence and the characteristic morphology of the potentials. Vagal stimulation resulted in a short-lasting initial slowing of spontaneous rate followed by a long-lasting secondary slowing; a brief period of relative or absolute acceleration was interposed between the two slowing phases. During these changes of spontaneous rate, the leading pacemaker site shifted in a complex beat-to-beat manner by 1-6 mm alongside the crista terminalis in the superior or inferior direction. For the first spontaneous excitation following stimulation, the greater the slowing, the larger the distance of the pacemaker shift. There was no such linear relationship between the extent of slowing and the distance of pacemaker shift for the subsequent beats. These changes in the leading pacemaker site in response to vagal stimulation may be the result of the functional and morphological heterogeneity of the mammalian SA node in terms of innervation, receptor distribution and ion channel densities. Experimental Physiology (2001) 86.2, 177-184.

Effects of concomitant use of doxifluridine, radiotherapy and immunotherapy in patients with advanced cervical cancer

Clinical effects of doxifluridine (group A, 600 mg/body/day; group B, 800 mg/body/day) combined with radiotherapy and immunotherapy were evaluated in patients with advanced cancer of the uterine cervix. Response rates were 84.2% (16/19 patients) in group A and 100% (18/18 patients) in group B, respectively (p=0.230). There was no significant difference in adverse reaction incidence between the methods but significantly higher grade adverse reaction were observed in group B than in group A (p=0.048). Time to progression (TTP) was longer in group B than in group A (p=0.081). The optimal 5'-DFUR dose was 800 mg/body (group B), by which higher grade adverse reactions were fully controlled and TTP was prolonged.

Acupuncture on clinical symptoms and urodynamic measurements in spinal-cord-injured patients with detrusor hyperreflexia

OBJECTIVES

We investigated the possible use of acupuncture for the treatment of urinary incontinence caused by detrusor hyperreflexia in patients with chronic spinal cord injuries.

METHODS

A total of 13 patients (11 males, 2 females) suffering from urinary incontinence due to spinal cord injuries were treated by acupuncture, which was carried out with disposable stainless steel needles inserted into the bilateral BL-33 (Zhongliao) points on the skin of the third posterior sacral foramina. Urodynamic studies were also performed before acupuncture, immediately after the 1st acupuncture and 1 week after the 4th acupuncture. In 6 patients, these urodynamic studies were performed again 1 month after the 4th acupuncture.

RESULTS

No side effects were recognized throughout the treatment period. Of the 13 patients, incontinence disappeared in 2 (15%) and decreased to 50% or less compared to baseline in a further 6 (46%). Maximum cystometric bladder capacity increased significantly from 76.2 +/- 62.3 to 148.1 +/- 81.5 ml 1 week after the 4th acupuncture (p < 0.01). In the 6 patients in whom cystometry was repeated 1 month after the 4th acupuncture, bladder capacity decreased from 187.5 +/- 90.4 ml 1 week after the 4th acupuncture to 128.3 +/- 93.4 ml.

CONCLUSION

In spinal cord injury patients acupuncture could represent another valuable therapeutic alternative to the treatment of urinary incontinence caused by detrusor hyperreflexia.

Gonadal regulation of PrRP mRNA expression in the nucleus tractus solitarius and ventral and lateral reticular nuclei of the rat

We investigated the prolactin-releasing peptide (PrRP) gene expression quantitatively in the rat brain and the involvement of estrogen and progesterone using in situ hybridization. The strongest signals were observed in the nucleus tractus solitarius (NTS), which showed approximately 70% of total PrRP mRNA in the brain. Moderate expression was observed in the ventral and lateral reticular nuclei (VLRN) of the medulla oblongata. PrRP mRNA signals in the hypothalamic ventromedial- and dorsomedial nuclei showed only 5% of total signals. The PrRP mRNA expression among female rats showing normal gonadal cycle and male rats showed that the highest levels were in female rats in proestrus. Administration of estrogen or progesterone after ovariectomy induced an increase in PrRP mRNA expression in the NTS. PrRP mRNA content in the NTS increased with the progress of the pregnancy and reached a peak on the 14th day, the mid-period of pregnancy, when plasma progesterone increases. We also observed the colocalization of PrRP and estrogen receptor alpha in the neurons distributed in the NTS by double labeling immunocytochemistry. These findings indicate that PrRP gene expression is regulated by gonadal steroid hormones in the medulla oblongata, and parts of PrRP synthesizing neurons are considered to be directly influenced by estrogen in the NTS.

Gap junction remodeling in hypertrophied left ventricles of aortic-banded rats: prevention by angiotensin II type 1 receptor blockade

Remodeling of gap-junctional organization in hypertrophied left ventricle (LV) in response to pressure overload in rats induced by abdominal aorta banding was investigated by immunoconfocal and electron microscopy. Eight to 12 weeks after banding, rats developed significant LV hypertrophy. In contrast to control LV myocytes, which showed connexin43 (Cx43) labeling largely confined to the intercalated disks, LV myocytes from aortic-banded rats showed dispersion of punctate Cx43 labeling over the entire cell surface. In LV tissues sectioned longitudinally, the proportion of Cx43 label at the intercalated disk decreased significantly (control, 0.87 v aortic-banded, 0.62). En-face views of intercalated disks of hypertrophied myocardium revealed a reduction of Cx43 gap junctions in the disk center, giving rise to a significant decrease in the proportion of the disk occupied by gap-junctional membrane (control, 0.32 v aortic-banded, 0.24). Electron microscopy of hypertrophied LV tissue revealed that Cx43-containing gap junctions were frequently displaced from their usual locations to form side-to-side contacts distant from the disk, and also appeared as annular profiles. In aortic-banded rats treated with the angiotensin II (AII) type 1 receptor (AT1) antagonist, losartan (10 mg/kg/day, 11 weeks) not only LV hypertrophy, but also the gap junction disorganization was markedly reduced. These results suggest that LV hypertrophy induced by pressure overload is associated with Cx43 gap junction disorganization and that AII may play an important role either directly or indirectly in gap-junctional remodeling.