The Associated Factors of Low Birthweight Among Term Singletons in Japan: A Pregnancy Birth Registry Analysis

BACKGROUND

Progress in reducing the global low birthweight (LBW) has been insufficient. Although the focus has been on preventing preterm birth, evidence regarding LBW in term births is limited. Despite its low preterm birth prevalence, Japan has a higher LBW proportion than other developed countries. This study aimed to examine the prevalence of LBW in term singleton births and its associated factors using a national database.

METHODS

We retrospectively analyzed the data of neonates registered in the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System who were born 2013-2017. Exclusion criteria included stillbirths, delivery after 42 gestational weeks, and missing data. Logistic regression analyses were performed to investigate the maternal and perinatal factors associated with LBW in term singletons using the data of 715,414 singleton neonates.

RESULTS

The overall prevalence of LBW was 18.3%, and 35.7% of LBWs originated from singleton term pregnancies. Multiple logistic regression analyses indicated that both modifiable and non-modifiable factors were independently associated with LBW in term neonates. The modifiable maternal factors included pre-pregnancy underweight, inadequate gestational weight gain, and smoking during pregnancy, while the non-modifiable factors included younger maternal age, nulliparity, hypertensive disorders of pregnancy, cesarean section delivery, female offspring, and congenital anomalies.

CONCLUSION

Using the Japanese pregnancy birth registry data, more than one-third of LBWs were found to originate from singleton term pregnancies. Both modifiable and non-modifiable factors were independently associated with LBW in term neonates. Prevention strategies on modifiable risk factor control will be effective in reducing LBW worldwide.

DNA methylation analysis of cord blood samples in neonates born to gestational diabetes mothers diagnosed before 24 gestational weeks

INTRODUCTION

Genome-wide methylation analyses of gestational diabetes mellitus (GDM) diagnosed after 24 gestational weeks (late GDM (L-GDM)) using cord blood have been reported. However, epigenetic changes in neonates born to mothers with GDM diagnosed before 24 gestational weeks (early GDM (E-GDM)) have not been reported. We investigated DNA methylation in neonates born to mothers with E-GDM using cord blood samples.

RESEARCH DESIGN AND METHODS

Genome-wide DNA methylation analysis was performed using an Illumina EPIC array to compare methylation rates of 754 255 autosomal sites in cord blood samples from term neonates born to 162 mothers with GDM (E-GDM: n=84, L-GDM: n=78) and 60 normal glucose tolerance (normal OGTT) pregnancies. GDM was diagnosed based on Japan Society of Obstetrics and Gynecology criteria modified with International Association of Diabetes in Pregnancy Study Group criteria. In this study, all GDM mothers underwent dietary management, while self-monitoring of blood glucose and insulin administration was initiated when dietary modification did not achieve glycemic control.

RESULTS

There were no significant differences in genome-wide DNA methylation of cord blood samples between the GDM (E-GDM and L-GDM) groups and normal OGTT group or between the E-GDM and normal OGTT groups, L-GDM and normal OGTT groups, and E-GDM and L-GDM groups.

CONCLUSIONS

This is the first report to determine the DNA methylation patterns in neonates born to mothers with E-GDM. Neonates born to mothers with GDM, who were diagnosed based on Japan Society of Obstetrics and Gynecology criteria, may not differ in DNA methylation compared with those born to normal OGTT mothers.

Predictors of later insulin therapy for gestational diabetes diagnosed in early pregnancy

Interventions for gestational diabetes mellitus (GDM), diagnosed in early pregnancy, have been a topic of controversy. This study aimed to elucidate factors that predict patients with GDM diagnosed before 24 gestational weeks (early GDM: E-GDM) who require insulin therapy later during pregnancy. Furthermore, we identified patients whose impaired glucose tolerance should be strictly controlled from early gestation onward. Women diagnosed with GDM were categorized based on the gestational age at diagnosis into E-GDM (n = 388) or late GDM (L-GDM, diagnosed after 24 weeks, n = 340) groups. Clinical features were compared between the groups, and the predictors for insulin therapy was evaluated in the E-GDM group. There were no significant between-group differences in terms of perinatal outcomes (e.g., gestational weeks at delivery, fetal growth, hypertensive disorder of pregnancy), with the exception of the Apgar score at 5 min. Moreover, there was no significant difference in the frequency of insulin therapy during pregnancy between the two groups. Using multiple logistic regression analysis, pre-pregnancy body mass index (BMI) ≥25 kg/m², a family history of diabetes, and higher fasting plasma glucose (FPG), 1 h-plasma glucose (PG), and 2 h-PG values increased insulin therapy risk during pregnancy in the E-GDM group. Furthermore, since E-GDM patients with abnormal levels of FPG, as well as 1 h-PG or 2 h-PG, and those with pre-pregnancy BMI ≥25 kg/m² and a family history of diabetes had a higher risk of later insulin therapy during pregnancy, they may require more careful follow-up in the perinatal period.

New strategy for diagnosing abnormal glucose tolerance before 24 gestational weeks during the coronavirus disease 2019 pandemic

The Japanese abnormal glucose tolerance before 24 gestational weeks diagnostic strategy in the evolving coronavirus disease 2019 pandemic published by the Japanese Society of Diabetes and Pregnancy.

Expectant management for early pregnancy miscarriage after radical trachelectomy: A single hospital-based study

INTRODUCTION

Women who have undergone radical trachelectomy as a fertility-sparing treatment for early-stage cervical cancer may be at higher risk for retained tissues after early-term miscarriage due to cervical cerclage or cervical necrosis. Dilatation and curettage or aspiration may present additional risks in these women. The aim of this study was to assess the efficacy of expectant management for early pregnancy miscarriage after radical trachelectomy.

MATERIAL AND METHODS

Keio University Hospital records were reviewed for women who conceived after abdominal radical trachelectomy and received perinatal care between 1 April 2012 and 31 March 2020. A total of 62 women (76 pregnancies) were identified, and 13 of these women experienced miscarriage before 12 gestational weeks. The management and outcome of these cases were reviewed in detail.

RESULTS

The median maternal age at miscarriage was 39 years (range 31-42 years) and the median duration from abdominal radical trachelectomy to conception was 2.60 years (range 0.49-7.30 years). Cervical necrosis before conception occurred in one case (8%). One patient requested treatment with aspiration and the remaining 12 cases were managed with observation for a median of 23 days (range 7-50 days). There were no cases of endometritis or cases requiring dilatation and curettage for residue tissue. Further, no cases developed laceration of the residual cervix and no loss of cerclage sutures after discharge was noted.

CONCLUSIONS

Expectant management seems to be safe and appropriate for first trimester miscarriage after abdominal radical trachelectomy.

Epigenetic Changes in Neonates Born to Mothers With Gestational Diabetes Mellitus May Be Associated With Neonatal Hypoglycaemia

The detection of epigenetic changes associated with neonatal hypoglycaemia may reveal the pathophysiology and predict the onset of future diseases in offspring. We hypothesized that neonatal hypoglycaemia reflects the in utero environment associated with maternal gestational diabetes mellitus. The aim of this study was to identify epigenetic changes associated with neonatal hypoglycaemia. The association between DNA methylation using Infinium HumanMethylation EPIC BeadChip and neonatal plasma glucose (PG) level at 1 h after birth in 128 offspring born at term to mothers with well-controlled gestational diabetes mellitus was investigated by robust linear regression analysis. Cord blood DNA methylation at 12 CpG sites was significantly associated with PG at 1 h after birth after adding infant sex, delivery method, gestational day, and blood cell compositions as covariates to the regression model. DNA methylation at two CpG sites near an alternative transcription start site of ZNF696 was significantly associated with the PG level at 1 h following birth (false discovery rate-adjusted P < 0.05). Methylation levels at these sites increased as neonatal PG levels at 1 h after birth decreased. In conclusion, gestational diabetes mellitus is associated with DNA methylation changes at the alternative transcription start site of ZNF696 in cord blood cells. This is the first report of DNA methylation changes associated with neonatal PG at 1 h after birth.

Development of a novel hybrid method combining finite difference method and dissipative particle dynamics to simulate thrombus formation on orifice flow

In our previous works, the transport of activated platelets (APs) on orifice flow has been simulated by finite difference method (FDM). And the distribution of AP concentration on the flow was obtained. However, the effect of platelet aggregation on the distribution of AP concentration can't be investigated by FDM because FDM can't simulate platelet aggregation. On the other hand, platelet aggregation has been simulated by dissipative particle dynamics (DPD). In this paper, a hybrid method combining FDM and DPD is proposed to investigate the effect of platelet aggregation on the distribution of AP concentration. And the hybrid method is used to simulate thrombus formation on orifice flow. As for the effect of platelet aggregation, it is found that the distribution of AP concentration in the hybrid method is different from the distribution in FDM at the places of platelet aggregation. It is considered that the difference is induced by platelet aggregation. As for the distribution of thrombus, higher AP concentration and more aggregated APs are found around the reattachment point and in the recirculation area. It is considered that thrombus is mainly distributed at these places in the simulation. And according to our previous experimental results, thrombus is mainly distributed around the reattachment point and in the recirculation area. It is concluded that the effect of platelet aggregation on the distribution of AP concentration can be investigated by the hybrid method, and the computational results agree with our previous experimental results.

A key role for the subunit SUR2B in the preferential activation of vascular KATP channels by isoflurane

BACKGROUND AND PURPOSE

It has been postulated that isoflurane, a volatile anaesthetic, produces vasodilatation through activation of ATP-sensitive K+ (KATP) channels. However, there is no direct evidence for the activation of vascular KATP channels by isoflurane. This study was conducted to examine the effect of isoflurane on vascular KATP channels and compare it with that on cardiac KATP channels.

EXPERIMENTAL APPROACH

Effects of isoflurane on KATP channels were examined in aortic smooth muscle cells and cardiomyocytes of the mouse using patch clamp techniques. Effects of the anaesthetic on the KATP channels with different combinations of the inward rectifier pore subunits (Kir6.1 and Kir6.2) and sulphonylurea receptor subunits (SUR2A and SUR2B) reconstituted in a heterologous expression system were also examined.

KEY RESULTS

Isoflurane increased the coronary flow in Langendorff-perfused mouse hearts in a concentration-dependent manner, which was abolished by 10 microM glibenclamide. In enzymically-dissociated aortic smooth muscle cells, isoflurane evoked a glibenclamide-sensitive current (i.e. KATP current). In isolated mouse ventricular cells, however, isoflurane failed to evoke the KATP current unless the KATP current was preactivated by the K+ channel opener pinacidil. Although isoflurane readily activated the Kir6.1/SUR2B channels (vascular type), the volatile anesthetic could not activate the Kir6.2/SUR2A channels (cardiac type) expressed in HEK293 cells. Isoflurane activated a glibenclamide-sensitive current in HEK293 cells expressing Kir6.2/SUR2B channels.

CONCLUSION AND IMPLICATIONS

Isoflurane activates KATP channels in vascular smooth muscle cells and produces coronary vasodilation in mouse hearts. SUR2B may be important for the activation of vascular-type KATP channels by isoflurane.

Functional roles of cardiac and vascular ATP-sensitive potassium channels clarified by Kir6.2-knockout mice

-ATP-sensitive potassium (K(ATP)) channels were discovered in ventricular cells, but their roles in the heart remain mysterious. K(ATP) channels have also been found in numerous other tissues, including vascular smooth muscle. Two pore-forming subunits, Kir6.1 and Kir6.2, contribute to the diversity of K(ATP) channels. To determine which subunits are operative in the cardiovascular system and their functional roles, we characterized the effects of pharmacological K(+) channel openers (KCOs, ie, pinacidil, P-1075, and diazoxide) in Kir6.2-deficient mice. Sarcolemmal K(ATP) channels could be recorded electrophysiologically in ventricular cells from Kir6.2(+/+) (wild-type [WT]) but not from Kir6.2(-/-) (knockout [KO]) mice. In WT ventricular cells, pinacidil induced an outward current and action potential shortening, effects that were blocked by glibenclamide, a K(ATP) channel blocker. KO ventricular cells exhibited no response to KCOs, but gene transfer of Kir6.2 into neonatal ventricular cells rescued the electrophysiological response to P-1075. In terms of contractile function, pinacidil decreased force generation in WT but not KO hearts. Pinacidil and diazoxide produced concentration-dependent relaxation in both WT and KO aortas precontracted with norepinephrine. In addition, pinacidil induced a glibenclamide-sensitive current of similar magnitude in WT and KO aortic smooth muscle cells and comparable levels of hypotension in anesthetized WT and KO mice. In both WT and KO aortas, only Kir6.1 mRNA was expressed. These findings indicate that the Kir6.2 subunit mediates the depression of cardiac excitability and contractility induced by KCOs; in contrast, Kir6.2 plays no discernible role in the arterial tree.

Inhibitory effects of JTV-519, a novel cardioprotective drug, on potassium currents and experimental atrial fibrillation in guinea-pig hearts

1. We investigated the effects of JTV-519 (4-[3-(4-benzylpiperidin-1-yl)propionyl]-7-methoxy-2,3,4, 5-tetrahydro-1,4-benzothiazepine monohydrochloride), a novel cardioprotective drug, on the repolarizing K(+) currents in guinea-pig atrial cells by use of patch-clamp techniques. We also evaluated the effects of JTV-519 on experimental atrial fibrillation (AF) in isolated guinea-pig hearts. 2. In atrial cells stimulated at 0.2 Hz, JTV-519 in concentrations of 0.3 and 1 microM slightly prolonged the action potential duration (APD). The drug also reversed the action potential shortening induced by the muscarinic agonist carbachol in a concentration-dependent manner. 3. The muscarinic acetylcholine receptor-operated K(+) current (I(K.ACh)) was activated by the extracellular application of carbachol (1 microM), adenosine (10 microM) or by the intracellular loading of GTP gamma S (100 microM). JTV-519 inhibited the carbachol-, adenosine- and GTP gamma S-induced I(K.ACh) with the IC(50) values of 0.12, 2.29 and 2.42 microM, respectively, suggesting that the drug may inhibit I(K.ACh) mainly by blocking the muscarinic receptors. 4. JTV-519 (1 microM) inhibited the delayed rectifier K(+) current (I(K)). Electrophysiological analyses indicated that the drug preferentially inhibits I(Kr) (rapidly activating component) but not I(Ks) (slowly activating component). 5. In isolated hearts, perfusion of carbachol (1 microM) shortened monophasic action potential (MAP) and effective refractory period (ERP), and lowered atrial fibrillation threshold (AFT). Addition of JTV-519 (1 microM) inhibited the induction of AF by prolonging MAP and ERP. 6. We conclude that JTV-519 can exert antiarrhythmic effects against AF by inhibiting repolarizing K(+) currents. The drug may be useful for the treatment of AF in patients with ischaemic heart disease.

Magnetic resonance imaging of the male pelvic floor: the anatomical configuration and dynamic movement in healthy men

The male pelvic organs and the rhabdosphincter were visualized using magnetic resonance imaging (MRI) in five young male volunteers (mean age, 25.6 years). The prostate was crescent-shaped in three subjects and doughnut-shaped in two subjects. The external urethral sphincter (EUS) was located anterior to and lateral to the urethra but was rare on the rectal side. The membranous urethral length measured 28-35 mm (average, 31.0 mm). The pubourethral portion of the levator ani embraced the urinary bladder, the prostate, and the membranous urethra, and the most distal portion of the levator was thickened. During anal contraction, the EUS became thinner on both coronal and sagittal images and the levator was approximated closer to the urethra. Consequently, the prostate and the bladder base were elevated and the membranous urethra was elongated by 0-12mm (average, 5.6 mm). On sagittal images, the prostate, the membranous urethra, and the rectum were pulled closer to the pubic bone by anal contraction and the retropubic area became narrower. This study clearly demonstrated that MRI was useful in examining the anatomical configuration of the male pelvic floor and its dynamic movement during anal contraction.

Selective impairment of HCO3(-)-dependent pHi regulation by lysophosphatidylcholine in guinea pig ventricular myocardium

OBJECTIVE

The aim was to examine the effects of lysophosphatidylcholine (LPC), an amphiphilic lipid metabolite in ischemic myocardium, on intracellular pH (pH(i)) regulatory systems in guinea pig papillary muscles.

METHODS

In CO2/HCO(3-)-buffered Tyrode solution, pH(i), intracellular Na+ activity (aNai) and membrane potential of isolated guinea pig papillary muscles were measured using ion-selective microelectrode and conventional microelectrode. Standard ammonium prepulsing with 20 mM NH4Cl was used to produce an intracellular acid load, and effects of LPC on the pH(i) recovery from acidosis were evaluated in the absence and presence of a transport inhibitor.

RESULTS

LPC acidified the resting pH(i) by 0.03 +/- 0.01 pH units (n = 15, p < 0.01) concomitantly with a slight decrease in resting membrane potential and an increase in aNai in quiescent preparations. The pH(i) recovery rate from an intracellular acid load was decreased to 83 +/- 4% of the control value by 30 microM LPC (n = 8, P < 0.05) but not by 30 microM phosphatidylcholine (PC). In the presence of 10 microM 5-(N,N-hexamethylene) amiloride (HMA), a Na(+)-H+ exchange inhibitor, LPC still slowed pH(i) recovery from an intracellular acid load to 77 +/- 4% of the control (n = 5, P < 0.05). However, LPC failed to alter the pH(i) recovery rate in the presence of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS, 0.5 mM), a Na(+)-HCO3- symport inhibitor.

CONCLUSION

LPC impairs Na(+)-HCO3- symport but not Na(+)-H+ exchange, and LPC may potentiate its arrhythmogenic action by intensifying the intracellular acidosis in ischemic myocardium.

Pirmenol inhibits muscarinic acetylcholine receptor-operated K+ current in the guinea pig heart

We examined the effects of pirmenol and disopyramide on the muscarinic acetylcholine receptor-operated K+ current (I[K.ACh]) in atrial cells and on experimental atrial fibrillation in isolated guinea-pig hearts. In isolated atrial myocytes, both pirmenol and disopyramide concentration-dependently inhibited the I(K.ACh) induced by carbachol or intracellular loading of GTPgammaS. Their inhibitory effects on the carbachol-induced current were more potent than those on GTPgammaS-induced current, suggesting that these drugs inhibit I(K.ACh) mainly by blocking muscarinic receptors. In Langendorff-perfused hearts these drugs reversed the carbachol-induced decreases in effective refractory periods and atrial fibrillation threshold. These drugs may be useful for the prevention of vagally induced atrial fibrillation.

Inhibitory effect of amiodarone on the muscarinic acetylcholine receptor-operated potassium current in guinea pig atrial cells

It is well known that amiodarone is effective for the treatment of atrial fibrillation. However, effects of amiodarone on the muscarinic acetylcholine receptor-operated K+ current (IK.ACh), which plays an important role in the repolarization of atrial action potential, have not been evaluated. This study was undertaken to determine whether amiodarone inhibits the acetyl-choline-sensitive muscarinic K+ (KACh) channel by use of the patch-clamp technique. In isolated guinea pig atrial cells, IK.ACh was activated by extracellular application of carbachol (1 microM) or adenosine (10 microM) or by the intracellular loading of GTP gamma S (100 microM). Amiodarone inhibited the IK.ACh activated in these three different ways with similar IC50 values around 2 microM, which indicated that amiodarone directly depresses the function of the KACh channel itself and/or GTP-binding proteins. Single KACh channel current was also recorded by use of a pipette solution containing carbachol (1 microM) or atropine (10 microM) plus theophylline (100 microM) in a cell-attached configuration. Amiodarone at a concentration of 3 microM significantly decreased the open probability of the KACh channel in both conditions. Amiodarone also reversed the carbachol- and adenosine-induced action potential shortening in a concentration-dependent manner. In isolated guinea pig hearts, perfusion of 1 microM carbachol shortened the effective refractory period of the atria and lowered the atrial fibrillation threshold. Addition of 10 microM amiodarone reversed these electrophysiological parameters to the control level. These results suggest that amiodarone inhibits IK.ACh by depressing the function of the KACh channel itself and/or associated GTP-binding proteins. This effect of amiodarone may at least in part be involved in the antiarrhythmic action against atrial fibrillation.

Prediction of hemolysis in turbulent shear orifice flow

This study proposes a method of predicting hemolysis induced by turbulent shear stress (Reynolds stress) in a simplified orifice pipe flow. In developing centrifugal blood pumps, there has been a serious problem with hemolysis at the impeller or casing edge; because of flow separation and turbulence in these regions. In the present study, hemolysis caused by turbulent shear stress must occur at high shear stress levels in regions near the edge of an orifice pipe flow. We have computed turbulent shear flow using the low-Reynolds number k-epsilon model. We found that the computed turbulent shear stress near the edge was several hundreds times that of the laminar shear stress (molecular shear stress). The peak turbulent shear stress is much greater than that obtained in conventional hemolysis testing using a viscometer apparatus. Thus, these high turbulent shear stresses should not be ignored in estimating hemolysis in this blood flow. Using an integrated power by shear force, it is optimal to determine the threshold of the turbulent shear stress by comparing computed stress levels with those of hemolysis experiments or pipe orifice blood flow.

Effects of all-trans-retinoic acid on limb development in the genetic polydactyly mouse

Pdn/+ female mice, mated with Pdn/+ males, were treated with 40 mg/kg body weight of all-trans-retinoic acid (RA) intraperitoneally on day 10 or 11 of gestation, and effects on the limb development were investigated. RA treatment induced the shortening of stylopodium and zygopodium. In the present experiment, we focused on the differences between genotypes in the shortening of stylopodium and zygopodium induced by RA. The effects of RA were milder in Pdn/Pdn than +/- (Pdn/+ and/or +/+) fetuses. The differences between genotypes in the effects of RA were more significant in the group treated on day 11 than on day 10 of gestation. Cartilage of stylopodium and zygopodium was longer in day-13 Pdn/Pdn embryos exposed to RA on day 11 of gestation than those in similarly treated +/- embryos. Many apoptotic cells were observed in the mesenchyme of the forelimb plates at 12 hr after injection of RA on day 11 of gestation. These results suggest that the Pdn gene might influence the apoptosis induced by RA in the mesenchymal cells of the limb, causing milder effects in the shortening of stylopodium and zygopodium in Pdn/Pdn fetuses.

Reversible acquired tracheobronchomalacia of a combined crescent type and saber-sheath type

A case of tracheobronchomalacia (TBM) in a 71-year-old woman, who had suffered a cough syncope, is reported. It was a combination of both the crescent type (the posterior membranous portion of trachea or bronchus protrudes into the lumen) and the saber-sheath type (the lateral cartilaginous wall of trachea or bronchus protrudes into the lumen). In this patient, acute bronchitis had developed superimposed upon a chronic bronchitis in addition to age-related regressive changes of the trachea and bronchus. A TBM due to acute inflammation can be reversible, but aggressive airway management as well as medical treatment of the underlying inflammation are critical to a successful outcome.

The effects of ketamine on conduction velocity and maximum rate of rise of action potential upstroke in guinea pig papillary muscles: comparison with quinidine

Using standard microelectrode techniques, the effects of ketamine on the maximum rate of rise of action potential upstroke (Vmax) and the conduction velocity were examined and compared with the effects of quinidine, a sodium channel blocker, in isolated guinea pig papillary muscles. Both ketamine and quinidine decreased Vmax and the square of the conduction velocity in a concentration-dependent manner. The conduction slowing paralleled the decreases in Vmax, suggesting that the sodium current inhibition produced by these drugs is responsible for the conduction slowing. In the presence of quinidine, a train of stimulation after a quiescent period produced an exponential decline in Vmax, and the decrease in Vmax was enhanced by increasing stimulation frequency (i.e., use-dependent block). Ketamine significantly depressed Vmax of the first action potential after a long quiescent period (tonic block), and failed to produce a further decrease in Vmax during the subsequent train of stimulation. The decrease in Vmax was enhanced by simultaneous administration of ketamine and quinidine. Thus, ketamine decreases conduction velocity by inhibiting the sodium current. The mode of action on cardiac conduction is similar to that of quinidine, but different from that of volatile anesthetics which produce conduction slowing by impairing cell-to-cell coupling. However, ketamine produces a tonic block of the sodium channel while quinidine produces a use-dependent block. We conclude that ketamine should be administered with caution to patients receiving Class I antiarrhythmic drugs.

[Effects of adrenergic drugs injected into the nucleus tractus solitarius region on the baroreceptor reflex in rabbits]

It has been presumed that a primary site of termination of the baroreceptor afferent was in the nucleus tractus solitarii (NTS). The intermediate region of the nucleus, located at the level of the obex, contains a large number of catecholamine neurons. The principal noradrenergic innervation of the NTS appears to arise from neurons of the so-called A2 group. It has been proposed that catecholamines released by A2 neurons serve to lower blood pressure and heart rate. We performed experiments to determine the effects of alpha-adrenoceptor agonists and antagonists on the baroreceptor reflex and alpha-adrenoceptor. Rabbits anesthetized with chloralose-urethane were injected with an alpha-adrenoceptor agonist, such as noradrenaline, phenylephrine or clonidine, into the NTS. An adrenoceptor-antagonist, such as yohimbine, phentolamine, prazosin or corynanthine was injected into the NTS of other anesthetized rabbits. Clonidine markedly lowered the blood pressure and heart rate, and it inhibited the baroreceptor reflex responses. Noradrenaline or phenylephrine did not lower the blood pressure and heart rate and scarcely inhibited the baroreceptor reflex. Yohimbine remarkedly inhibited the baroreceptor reflex responses; on the other hand, prazosin, corynanthine and phentolamine produced little inhibition of the responses. It is concluded that there are alpha 1- and alpha 2-receptors in the NTS of the rabbits, and the alpha 2-receptors play an important role in the neurotransmission in the NTS.

Carcinogenicity study of gamma-oryzanol in F344 rats

The carcinogenic potential of gamma-oryzanol, a drug mainly used for the treatment of hyperlipidaemia, was studied in F344 rats. Groups of 50 males and 50 females were fed a diet containing 0 (control), 200, 600 or 2000 mg gamma-oryzanol/kg body weight/day for 2 yr. Although females in the highest dose group (2000 mg/kg body weight) showed a slight decrease in body weight at 104 wk, there were no treatment-related changes in general condition, food consumption, mortality, organ weight or haematology. Histopathological examination showed various tumours in all groups, including the control group. In the control and 2000-mg/kg groups, high tumour incidences were observed in the testes, pituitary and thyroid of males, and in the pituitary, uterus and mammary gland of females; however, there was no significant increase in the incidence of any tumours between the control and the 2000-mg/kg groups. The findings indicate that under the experimental conditions described gamma-oryzanol was not carcinogenic in F344 rats.

[Central stimulating effect of the combination of the new quinolone group of antimicrobials and nonsteroidal anti-inflammatory drugs in mice]

Six new quinolones: enoxacin, norfloxacin, ofloxacin, ciproflosacin, lomefloxacin, and tosufloxacin and eight nonsteroidal anti-inflammatory drugs: fenbufen, flurbiprofen, ketoprofen, pranoprofen, ibuprofen, indomethacin, mefenamic acid and aspirin were tested for their ability to produce a central stimulating effect in mice. At 5 min after the oral administration of one of the nonsteroidal anti-inflammatory drugs, a new quinolone was administered orally. The combination of drugs induced convulsions in a dose-dependent manner, and some mice died as a result of the convulsions. The survival time was used as an index to measure the intensity of convulsions induced by the drug combination. The new quinolones in combination with fenbufen at 100 mg/kg produced convulsions in the following order of potencies: enoxacin greater than lomefloxacin greater than norfloxacin. In contrast, administration of fenbufen together with ofloxacin, ciprofloxacin, or tosufloxacin up to a dose of 1000 mg/kg caused no convulsions. Four nonsteroidal anti-inflammatory drugs combined with enoxacin at 100 mg/kg also caused convulsion dose-dependently. The order of potency in producing convulsion was as follows: fenbufen greater than flurbiprofen greater than ketoprofen = pranoprofen. However, no convulsions were produced by treatment of ibuprofen, indomethacin, mefenamic acid or aspirin together with enoxacin. From these results, the important chemical structures of the new quinolones particularly concerned with the appearance of convulsion were discussed.

[Effects of the combination of new quinolones and a nonsteroidal anti-inflammatory drug, fenbufen, on the EEG of rabbits]

A combination of fenbufen, a non-steroidal anti-inflammatory drug and the new quinolone produces a central stimulating action. To confirm the action, we used 6 kinds of new quinolones: enoxacin, norfloxacin, ofloxacin, ciprofloxacin, lomefloxacin and tosufloxacin in this experiment. The convulsive effects of these drugs were tested on the EEG recorded from the neocortex and subcortical regions of the rabbits. Animals treated with fenbufen (50-200 mg/kg, p.o.) tended to have a high amplitude slow wave in their EEG. Rabbits treated with the new quinolones at the dose of 100 mg/kg, p.o., with the exception of tosufloxacin, also tended to show a high amplitude slow wave in their EEG. Each new quinolone given 30 min after fenbufen (50 mg/kg, p.o.) elicited characteristic spikes on the EEG. Then, high-frequency-spikes and epileptiform seizure waves appeared for a long experimental period with this combination. The combination of fenbufen and tosufloxacin (100-400 mg/kg, p.o.) caused no changes in EEG and behavior. The spike and epileptiform wave could be suppressed only temporarily with diazepam (1-4 mg/kg, i.v.). These results suggest that combined use of fenbufen and one of the new quinolones, except for tosufloxacin, produces the seizure. Not only GABA but also several other mechanisms in the central nervous system may be involved in the convulsion.

Carcinogenicity study of gamma-oryzanol in B6C3F1 mice

The carcinogenic potential of gamma-oryzanol, a drug mainly used for the treatment of hyperlipidaemia, was studied in B6C3F1 mice. Groups of 50 males and 50 females were fed a diet containing 0 (control), 200, 600 or 2000 mg gamma-oryzanol/kg body weight/day for 78 wk. No treatment-related changes were observed in general condition, body weight, food consumption, mortality, organ weight or haematology. Histopathological examinations showed various tumours in all groups, including the control group. In the control and 2000-mg/kg groups, relatively high tumour incidences were observed in the liver of males and in the haematopoietic organs of females. However, there was no statistically significant difference in the incidence of any tumours between the control and the 2000-mg/kg groups. The findings indicate that under the experimental conditions described gamma-oryzanol was not carcinogenic in B6C3F1 mice.

Intraarterial digital subtraction angiography in detection of hepatocellular carcinoma

To evaluate the usefulness of intraarterial digital subtraction angiography (IADSA) in hepatocellular carcinoma, IADSA was prospectively performed, combined with conventional film-screen angiography, in 40 patients in whom the tumor was histologically proven or highly suspected. Of the 16 main tumors less than 2 cm, IADSA detected 7 that were missed by film-screen angiography; 6 of these were less than 1 cm in size. With other diagnostic modalities including ultrasound, routine CT study, and CT after intraarterial Lipiodol injection, the detection rate of these tumors was low. IADSA's contribution is important in the detection of small hepatocellular carcinomas.

[A case of metastatic malignant melanoma mimicking pancreatic pseudocyst]

A 74-year-old male was admitted to our hospital complaining of an abdominal mass. Abdominal US and ERCP disclosed a cyst in the pancreas, communicating with a crater in the stomach. Spontaneous rupture of a pancreatic pseudocyst into the stomach was considered. Laparotomy demonstrated an irregular black pancreatic cyst, and histological examination showed atypical spindle shaped cells with brown to black pigmentation, compatible with malignant melanoma. Autopsy confirmed the diagnosis of malignant melanoma involving the pancreas, stomach and other organs. Efforts to elucidate the primary site were unsuccessful, Metastatic melanoma without a primary site is well known and has been reported to occur in from 2.4% to 8.7% of all cases. This case suggests that malignant melanoma must be considered in cases of tumors with various symptoms and multiple metastases without a definite primary site.

[Two-dimensional echo-cardiographic study on left atrial thrombi in patients with a mitral prosthetic valve]

Two-dimensional echocardiographic study was performed to detect left atrial thrombi in 33 patients with a prosthetic mitral valve. The subjects were 9 males and 24 females and their ages ranged from 21 to 61 years (average 43.2 years). Their prosthetic valves consisted of 18 Hancock, three Carpentier-Edwards, four Björk-Shiley, four Starr-Edwards and four St. Jude Medical valves. Two-dimensional echocardiograms were obtained using a Toshiba SSH-11A echograph with an electronic phased-array scanner. The left parasternal, apical, subcostal and right parasternal windows were used to detect left atrial thrombi. In five of the 33 patients, a left atrial thrombus was demonstrated as a mass echo attached to the posterior wall of the left atrium. The clinical and echographic features of five patients with a left atrial thrombus (Group A) were compared to those of 28 patients without it (Group B). The average age at the time of operation was 44.6 +/- 9.7 years in Group A and 43.0 +/- 9.5 years in Group B, showing no difference between the two groups. In 10 of the 33 patients, a left atrial thrombus was confirmed by the initial operation. In only one of these 10 patients, a left atrial thrombus was demonstrated by post-operative two-dimensional echocardiographic examination. The presence or absence of a left atrial thrombus in the pre-operative stage did not clearly relate to the occurrence of a left atrial thrombus in the post-operative stage. The cardio-thoracic ratio was significantly greater (p less than 0.01) in Group A (74.4 +/- 6.3%) than in Group B (58.1 +/- 8.1%). Left atrial dimension by M-mode echocardiograms was significantly greater (p less than 0.05) in Group A (70.6 +/- 11.3 mm) than in Group B (51.6 +/- 7.7 mm). The length of the pseudo-septalized left ventricular posterior wall was longer (p less than 0.05) in Group A (34.0 +/- 11.5 mm) than in Group B (12.8 +/- 9.4 mm). The angle between the perpendicular to the mitral annulus and the upper part of the interventricular septum was significantly greater (p less than 0.01) in Group A (58.6 +/- 18.0 degrees) than in Group B (18.8 +/- 9.6 degrees). The characteristics observed in Group A were thought to be caused mainly by the giant left atrium. Therefore it is concluded that there is a close relationship between left atrial thrombi and the giant left atrium in patients with a mitral prosthetic valve.

Modulation of somatostatin release by endogenous glucagon and insulin: physiological relationship between A, B and D cells in rat pancreatic islets

In order to understand the physiological role of endogenous insulin or glucagon in somatostatin release, isolated rat pancreatic islets were treated with antiinsulin or antiglucagon antiserum in the presence of physiological amounts of glucose. The release of somatostatin was unchanged by treatment with antiinsulin antiserum which neutralized insulin released by 3.3, 8.3 and 16.7 mM of glucose. However, somatostatin release after treatment with antiglucagon antiserum was much reduced at all concentrations of glucose when compared with the release from control serum. Exogenous rat insulin (0.11, 1.11 micrograms/ml) had no effect, but exogenous glucagon (1, 5 micrograms/ml) resulted in a significant increase. Somatostatin release was stimulated by glucose, but the effect was insignificant. These results clearly indicate the physiological role of endogenous glucagon in the modulation of somatostatin release from the islets of Langerhans. Furthermore, the physiological relationship between A, B and D cells may be mediated through the paracrine mechanism.

[Evaluation of left ventricular diastolic chamber stiffness by the apexcardiogram and echocardiogram]

This study was made to evaluate left ventricular (LV) chamber stiffness noninvasively utilizing the apexcardiogram and echocardiogram. Subjects were 13 patients with left ventricular hypertrophy (LVH) and 17 patients without LVH. Cardiac catheterization and LV angiography were also performed in all patients. In the apexcardiogram, as shown in Figs. 1 and 2, the ratios of an amplitude to the total amplitude were measured at the onset of left atrial systole (H1) (80 msec after the onset of the P wave) and the peak of A wave (H2). In the echocardiogram, LV internal diameters were determined at 80 msec after the onset of the P wave (D1) and the peak of the R wave of ECG (D2). In addition left ventricular volumes, V1 and V2, were calculated by D1 and D2 using Teichholz's method. Increments of the ratio of an amplitude of the ACG wave (delta H = H2-H1) and LV volume changes (delta V = V2-V1) which are associated with left atrial systole were calculated. The ratio of delta H to delta V (delta H/delta V) was defined as a measure of LV diastolic chamber stiffness. On the other hand, various parameters (delta P/delta V, K, dV/dP, dV/VdP) which represent LV diastolic properties were determined by LV pressure curves and LV cineangiograms. delta H/delta V by noninvasive method showed good correlations with delta P/delta V (r = 0.83), K (r = 0.68), dV/dP (r = -0.80) and dV/VdP (r = -0.75), respectively. The correlations were much better between delta H/delta V and these parameters than between A/Eo and these parameters. Patients with LVH had much greater diastolic stiffness (delta H/delta V = 2.03 +/- 1.10) than those without LVH (delta H/delta V = 0.60 +/- 0.29, p less than 0.01). It is concluded that delta H/delta V obtained from ACG and the echocardiogram is a useful parameter to evaluate LV diastolic chamber stiffness noninvasively and this ratio is well correlated with LVH.

Role of glucagon and somatostatin in insulin release

The role of endogenous glucagon and somatostatin in insulin release was studied. Islets isolated from adult rats were incubated for 60 min in 3.3, 8,3 and 16.7 mM glucose with anti-glucagon antiserum (AGA) or anti-somatostatin antiserum (ASA) which was produced in rabbits. For the control experiments the antiserum was replaced by normal rabbit serum (NRS). Insulin release from islets treated with AGA was suppressed in 3.3 and 8.3 mM glucose as compared to islets treated with NRS, while insulin release was not affected in 16.7 mM glucose. On the other hand, insulin release from islets treated with ASA was enhanced in 3.3 and 8.3 mM glucose as compared to that from islets treated with NRS, whereas in 16.7 mM glucose it was not different from the control. These observations indicate that endogenous glucagon and somatostatin play a physiological role in the regulation of insulin release, but their regulation of insulin release is deranged at non-physiologically high glucose concentrations.

[The maintenance of insulin secretory response of long-term cultured pancreatic islets to glucose, acetylcholine and epinephrine (author's transl)]

The present study was performed to investigate whether long-term cultured rat pancreatic islets possess a postcultural insulin secretory response to hormones and neurotransmitters in spite of their lack of stimulation during the culture period. We also investigated the method of maintaining the insulin secretory response of islets cultured in a physiological concentration of glucose. The tissue culture media were TCM 199 supplemented with 5.5 mM glucose (A medium), 5.5 mM glucose plus 1 mM adenosine (B medium), 16.7 mM glucose (C medium), and 16.7 mM glucose plus 1 mM adenosine (D medium). Short-term incubation after the culture period of 14 days showed that the islets cultured in B, C and D media maintained the same insulin secretory responsiveness to 8.3 mM glucose and/or 5 microM acetylcholine and also to 1 microM epinephrine as did non-cultured islets. A similar response was found among the islets maintained in B, C and D media. An insulin secretory response to epinephrine and phentolamine was deficient in islets cultured in A medium, whereas it was maintained in those cultured in C medium. The responsiveness of the islets cultured in C medium to the concomitant stimulation by epinephrine and phentolamine was not different from that of the non-cultured islets. It was thus concluded that the addition of adenosine in the culture medium containing the physiological concentration of glucose was as effective in amintaining the insulin secretory ability of the islets as was the culture medium containing a high concentration of glucose, and it was suggested that even the pancreatic islets cultured in these media, though separated from the innervation might preserve acetylcholine and adrenergic receptors similar to freshly isolated islets. Considering the action of adenosine, the necessity of enhancing ATP and C-AMP concentrations in B cells was also suggested in order to maintain the insulin secretory ability of cultured pancreatic islets.

Reproduction study of carteolol hydrochloride in mice. Part I. Fertility and reproductive performance

Carteolol was administered orally by gastric intubation at 3, 15, 75 or 150 mg/kg/day to ICR-JCL mice of both sexes prior to mating and to females during early stage of pregnancy to determine its effects on the entire reproductive process and fetal development. Following results were obtained: 1) The decrease of spontaneous motor activity was observed in all treatment groups, and some animals in the 75 mg/kg and 150 mg/kg groups pressed the chest or abdomen against the cage wall. 2) The incidence of early resorptions in the 75 mg/kg and 150 mg/kg groups was significantly higher than that in controls.3) The ossification of the talus and calcaneus was significantly retarded in the 75 mg/kg and 150 mg/kg groups. The maximum non-effective dose on fertility and reproduction for carteolol was estimated to be 15 mg/kg/day, although the incidence of early resorptions was slightly elevated with this dose.

Reproduction study of carteolol hydrochloride in mice. Part 2. Peri -and postnatal toxicity

Carteolol was orally administered to mice once a day at doses of 3, 30 and 150 mg/kg/day during the perinatal and lactation periods and evaluated on its adverse effects on pregnant animals and their offspring. No appreciably abnormal findings related to the drug administration were revealed. Therefore, it was concluded that carteolol have no serious toxic potential on parturition and lactation by mother animals, no adverse effects on growth and development, and behavioral and reproductive performance of offspring and no carcinogenic action through placental and milk transfer.

Evaluation of a commercial enzyme immunoassay for insulin in human serum, and its clinical application

We applied a "sandwich" method, with use of beads coated with anti-insulin serum and of peroxidase-labeled anti-insulin serum, to an enzyme immunoassay of insulin in human serum. 5-Aminosalicylic acid was used as the substrate for the enzymic reaction. As little as 5 milli-int. units of insulin per liter of serum insulin was detectable. Reproducibility was satisfactory, but extraordinarily high concentrations of proinsulin and of hydrogen donors such as reduced glutathione affect results of the assay. Values determined by our enzyme immunoassay and by double-antibody radioimmunoassay correlated highly (r = 0.938, p less than 0.001, n = 216). We recommend this method for use in the clinical laboratory.

Evaluation of a commercial enzyme immunoassay for insulin in human serum, and its clinical application

We applied a "sandwich" method, with use of beads coated with anti-insulin serum and of peroxidase-labeled anti-insulin serum, to an enzyme immunoassay of insulin in human serum. 5-Aminosalicylic acid was used as the substrate for the enzymic reaction. As little as 5 milli-int. units of insulin per liter of serum insulin was detectable. Reproducibility was satisfactory, but extraordinarily high concentrations of proinsulin and of hydrogen donors such as reduced glutathione affect results of the assay. Values determined by our enzyme immunoassay and by double-antibody radioimmunoassay correlated highly (r = 0.938, p less than 0.001, n = 216). We recommend this method for use in the clinical laboratory.