Correction: 'Transition mechanism for a periodic bar-and-joint framework with limited degrees of freedom controlled by uniaxial load and internal stiffness' (2018), by Tanaka et al

[This corrects the article DOI: 10.1098/rsos.180139.][This corrects the article DOI: 10.1098/rsos.180139.].

Creep trajectory transition of a nonstationary viscoelastic model onto a single rate parameter

A system of three-variable differential equations, which has a nonstationary trajectory transition through the control of a single rate parameter, is formulated. For the nondimensional system, the critical trajectory creeps before a transition in a long-lasting plateau region in which the velocity vector of the system hardly changes and then diverges positively or negatively in finite time. The mathematical model well represents the compressive viscoelasticity of a spring-damper structure simulated by the multibody dynamics analysis. In the simulation, the post-transition behaviors realize a tangent stiffness of the self-contacted structure that is polarized after transition. The mathematical model is reduced not only to concisely express the abnormal compression problem, but also to elucidate the intrinsic mechanism of creep-to-transition trajectories in a general system.

Auxetic vibration behaviours of periodic tetrahedral units with a shared edge

A very low-frequency mode supported within an auxetic structure is presented. We propose a constrained periodic framework with corner-to-corner and edge-to-edge sharing of tetrahedra and develop a kinematic model incorporating two types of linear springs to calculate the momentum term under infinitesimal transformations. The modal analysis shows that the microstructure with its two degrees of freedom has both low- and high-frequency modes under auxetic transformations. The low-frequency mode approaches zero frequency when the corresponding spring constant tends to zero. With regard to coupled eigenmodes, the stress-strain relationship of the uniaxial forced vibration covers a wide range. When excited, a very slow motion is clearly observed along with a structural expansion for almost zero values of the linear elastic modulus.

Transition mechanism for a periodic bar-and-joint framework with limited degrees of freedom controlled by uniaxial load and internal stiffness

A specific periodic bar-and-joint framework with limited degrees of freedom is shown to have a transition mechanism when subjected to an external force. The static nonlinear elasticity of this framework under a uniaxial load is modelled with the two angular variables specifying the rotation and distortion of the linked square components. Numerically exploring the equilibrium paths then reveals a transition state of the structure at a critical value of the internal stiffness. A simplified formulation of the model with weak nonlinear terms yields an exact solution of its transition state. Load-displacement behaviour and stability for the two systems with or without approximation are analysed and compared.

Ras-related C3 botulinum toxin substrate 1 (RAC1) regulates glucose-stimulated insulin secretion via modulation of F-actin

AIMS/HYPOTHESIS

The small G-protein ras-related C3 botulinum toxin substrate 1 (RAC1) plays various roles in mammalian cells, such as in the regulation of cytoskeletal organisation, cell adhesion, migration and morphological changes. The present study examines the effects of RAC1 ablation on pancreatic beta cell function.

METHODS

Isolated islets from pancreatic beta cell-specific Rac1-knockout (betaRac1(-/-)) mice and RAC1 knockdown INS-1 insulinoma cells treated with small interfering RNA were used to investigate insulin secretion and cytoskeletal organisation in pancreatic beta cells.

RESULTS

BetaRac1(-/-) mice showed decreased glucose-stimulated insulin secretion, while there were no apparent differences in islet morphology. Isolated islets from the mice had blunted insulin secretion in response to high glucose levels. In RAC1 knockdown INS-1 cells, insulin secretion was also decreased in response to high glucose levels, consistent with the phenotype of betaRac1(-/-) mice. Even under high glucose levels, RAC1 knockdown INS-1 cells remained intact with F-actin, which inhibits the recruitment of the insulin granules, resulting in an inhibition of insulin secretion.

CONCLUSIONS/INTERPRETATION

In RAC1-deficient pancreatic beta cells, F-actin acts as a barrier for insulin granules and reduces glucose-stimulated insulin secretion.

Synthesis and metal-ion binding properties of monoazathiacrown ethers

Synthetic procedures for monoazathiacrown ethers were explored, and monoazatrithia-12-crown-4, monoazatetrathia-15-crown-5, and monoazapentathia-18-crown-6 were obtained in moderate yields by the reaction of bis(2-chloroethyl)amine with the appropriate dithiols in the presence of lithium hydroxide in THF. To evaluate metal-ion binding properties of the monoazathiacrown ethers by solvent extraction, lipophilic dodecyl and dodecanoyl groups were incorporated onto the monoazathiacrown ethers. The solvent extraction experiments suggested that monoazathiacrown ethers have Ag(+) and Hg(2+) selectivities and that the relative selectivity between Ag(+) and Hg(2+) depends on their nitrogen atom properties and numbers of sulfur atoms reflecting the respective affinities of nitrogen and sulfur atoms to Hg(2+) and Ag(+). An interesting ability to bind Mg(2+) was observed in the case of N-dodecyl monoazatrithia-12-crown-4.

Chemiluminescence method with potassium permanganate for the determination of organic pollutants in seawater

A chemiluminescence method with potassium permanganate was developed for use as an indicator of organic pollutants in fresh water. This method could be applied to the determination of organic pollutants in seawater as well. However, the flow chemiluminescence method suffered from the interference of chloride ions at the same concentration of seawater because of the production of manganese dioxide in the oxidation of chloride ions with permanganate. The conditions (concentrations of potassium permanganate and sulfuric acid and sample volume, i.e. flow injection method) were chosen to minimize the interference of chloride ions. The chemiluminescence method shows a good correlation with the chemical oxygen demand method on fresh water added artificial sea salt and seawater samples. Natural seawater was analyzed by the chemiluminescence method. The results obtained were compared with those obtained by chemical oxygen demand under the alkaline condition and total organic carbon methods. The chemiluminescence method has higher sensitivity and reproducibility than the conventional chemical oxygen demand and total organic carbon methods.

Investigation on diabetic autonomic neuropathy assessed by power spectral analysis of heart rate variability in WBN/Kob rats

This article investigates the development of cardiovascular autonomic dysfunction caused by diabetes mellitus. We performed power spectral analysis of heart rate variability in WBN/Kob rats as a model of spontaneous diabetes. The heart rate of the rats was measured continuously for 24 hours with an implanted telemetric transmitter, and power spectral analysis of heart rate variability was performed on continuous electrocardiograms. At 4 to 5 months of age, the rats indicated a tendency toward a decrease in plasma insulin concentration without hyperglycemia. At 8 to 9 months of age, they showed remarkable hyperglycemia, loss of the circadian rhythm of the heart rate, and reversion or loss of the circadian rhythm of the blood pressure. By the power spectral analysis of heart rate variability, it became apparent that the circadian rhythm of the low frequency/high frequency ratio was absent even in prediabetic WBN/Kob rats. In addition, the circadian rhythms of the high-frequency power level and low frequency/high frequency ratio were absent in diabetic WBN/Kob rats. These findings indicate that the autonomic nervous system in WBN/Kob rats is progressively damaged from the prediabetic to diabetic state. In conclusion, diabetic autonomic neuropathy may be characterized by the appearance of sympathetic overactivity that precedes the impairment of parasympathetic activity.

Synthesis and photochromism of spirobenzopyran derivatives bearing an oxymethylcrown ether moiety: metal ion-induced switching between positive and negative photochromisms

Spirobenzopyran derivatives carrying an oxymethylcrown ether moiety were synthesized, and their photochromism was studied in the presence of various metal ions in acetonitrile. The metal ion complexing ability of the crown ether moiety in crowned spirobenzopyrans affects both thermal isomerization and photoisomerization of their spirobenzopyran moiety to a great extent. When the interaction of the crown ether moiety with a metal ion was strong enough to cause thermal isomerization of the spirobenzopyran moiety to its corresponding merocyanine form and to suppress UV-induced isomerization to the merocyanine form, a negative photochromism appears. On the other hand, a relatively weak interaction of the crown ether moiety with a metal ion affords a positive photochromism. This phenomenon enables us to switch the photochromic behavior between positive and negative photochromisms.

Human xanthine dehydrogenase cDNA sequence and protein in an atypical case of type I xanthinuria in comparison with normal subjects

To investigate the properties of xanthine dehydrogenase/xanthine oxidase (XDH/XO) deficiency in a patient with atypical type I xanthinuria, as indicated by oxypurine data, a cDNA sequence encoding XDH, XDH/XO immunoblot analysis and a competitive PCR assay were performed, and the results were compared with those of normal subjects. The xanthine dehydrogenase cDNA sequence of the patient was consistent with the controls, while immunologically reactive 150 kD XDH/XO protein was not present in the xanthinuric duodenal mucosa, unlike the control duodenal mucosa. In addition, a decrease in XDH/XO messenger RNA was found by competitive PCR. These results suggest that atypical type I xanthinuria is due to a decrease in messenger RNA of XDH/XO. Furthermore, it was considered that this decrease could explain the normal plasma level and near normal urinary excretion of hypoxanthine seen in this case of xanthinuria, though XDH/XO activity and protein were not detected spectrophotometrically and immunologically, respectively.

Spectral analysis of circadian rhythms in heart rate variability of dogs

OBJECTIVE

To determine characteristics of power spectral analysis of heart rate variability (HRV) during a 24-hour period in dogs and to evaluate the effects of vagal and sympathetic tone on HRV ANIMALS: 16 healthy adult Beagles.

PROCEDURE

Power spectral analysis of HRV was conducted, using 24-hour ambulatory ECG recordings. Circadian rhythms were evaluated in terms of absolute units of low-frequency (LF) and high-frequency (HF) powers, their ratio (LF:HF), and their adjusted (normalized) units (LF[norm] and HF[norm]). Three or 4 dogs were used for simultaneous measurement of heart rate and respiratory waveform as well as to evaluate treatment (propranolol, atropine, or both) administered to cause blockade of the autonomic nervous system.

RESULTS

Values for LF and HF powers, LF:HF, LF(norm), and HF(norm) had obvious rhythmicity in clinically normal dogs. The HF power of HRV in dogs was extremely high, compared with that of other species, and HF peaks corresponded to peaks obtained from respiratory waveforms. Blockade of the autonomic nervous system documented that HRV in dogs was mostly attributable to vagal activity.

CONCLUSION AND CLINICAL RELEVANCE

We determined characteristics of power spectral analysis of HRV in dogs, including circadian rhythm of the autonomic nervous system. Power spectral analysis of HRV may provide a useful noninvasive technique for assessing the effect of drugs on activity of the autonomic nervous system in dogs.

Long-term administration of highly purified eicosapentaenoic acid ethyl ester improves the dysfunction of vascular endothelial and smooth muscle cells in male WBN/Kob rats

We investigated the effect of long-term administration of highly purified eicosapentaenoic acid ethyl ester (EPA-E), an n-3 polyunsaturated fatty acid, on the dysfunction of the endothelium and smooth muscle cells in male WBN/Kob rats, a model of spontaneous diabetes mellitus. After oral 8-month treatment with EPA-E, the agent significantly and dose-dependently increased the migration activity of vascular endothelial cells and also decreased 5-bromodeoxyuridine (BrdU) uptake by vascular smooth muscle cells at a dose of 0.1 g/kg or higher. In addition, there were significant correlations between the endothelial cell migration or smooth muscle cell proliferation and the 4-hour fasting glucose level. These findings suggest that EPA-E has a suppressive effect on thrombosis and atherosclerosis.

Abnormal haemoglobins, Hb Takamatsu and Hb G-Szuhu, detected during the analysis of glycated haemoglobin (HbA1C) by high performance liquid chromatography

BACKGROUND

During medical checkups of two unrelated female outpatients during their annual health examination and one male inpatient suffering from cardiac failure the glycated haemoglobin (HbA1C) concentrations measured by high performance liquid chromatography (HPLC) were low, in spite of normal fasting plasma glucose concentrations. However, HbA1C concentrations measured by latex immunoagglutination and fructosamine concentrations were within the normal range.

METHOD

Investigations were performed to elucidate the reasons for these discrepancies.

RESULTS

Abnormal haemoglobins, Hb Takamatsu and Hb G-Szuhu, were found. The HPLC chromatogram showed an additional peak near HbA1a + b, which resulted in falsely low HbA1C concentrations. Isoelectric focusing analysis of the patients' haemoglobin disclosed abnormal haemoglobins, which migrated faster than normal HbA1 in the two female patients and slower in the male patient. The cDNA sequence and amino acid analyses of the haemoglobin alpha-chains and beta-chains indicated the presence of the haemoglobin variant beta 120 Lys-->Gln in the two female patients and beta 80 Asn-->Lys in the male patient; that is, Hb Takamatsu and Hb G-Szuhu.

CONCLUSIONS

These cases show how these silent haemoglobin variants can result in falsely low HbA1C concentration readings when using HPLC.

Growth-stimulating effect of dienogest, a synthetic steroid, on rodent, canine, and primate mammary glands

We observed hyperplasia of the mammary gland in female beagle dogs, but not in female rats and monkeys, in 91-day toxicity studies on dienogest. In order to elucidate a possible mechanism for its development and to account for this species difference, we determined the plasma level of growth hormone (GH) in dogs, rats, and monkeys treated orally with dienogest for 91 days. As a result, dogs with mammary hyperplasia showed a prominent, dose-dependent increase in their GH level; and, contrarily, rats and monkeys without the hyperplasia of this organ failed to show any such increase. These results were supported by evidence from immunohistochemical and morphometric analysis of the pituitary gland. In addition, dienogest and medroxyprogesterone acetate (MPA) stimulated the growth of canine mammary epithelial cells in the presence of estradiol in vitro, but had no effect on rat and human mammary epithelial cells incubated under the same conditions. In conclusion, dienogest with progestational activity caused proliferation of the mammary gland in beagle dogs by increasing the secretion of GH, as do other progestational compounds. This change may be partially dependent on the direct effect of the drug.

[Intrasellar epidermoid cyst]

We report a rare case of intrasellar epidermoid cyst. A 61-year-old man presented with complaints of the disturbance of consciousness and general fatigability. His laboratory data showed panhypopituitarism and MRI revealed the cystic tumor located at the intrasellar region. Tumor was removed by transsphenoidal approach and histological examination of the surgical specimen showed that the cyst wall was composed of the stratified squamous epithelium with keratohyaline granules.

Long-term administration of highly purified eicosapentaenoic acid ethyl ester prevents diabetes and abnormalities of blood coagulation in male WBN/Kob rats

We investigated the effect of long-term administration of highly purified eicosapentaenoic acid ethyl ester (EPA-E), an n-3 polyunsaturated fatty acid, on the development of diabetes, insulin resistance, and abnormalities of blood coagulation in male WBN/Kob rats, a model of spontaneous diabetes mellitus. After 8-month oral EPA-E treatment, the incidence of diabetes at a dose of 0.1, 0.3, and 1.0 g/kg was 92%, 50%, and 17%, respectively. Its incidence was suppressed significantly and dose-dependently at a dose of 0.3 g/kg or higher compared with the rate (100%) for the vehicle control. Additionally, EPA-E significantly and dose-dependently decreased the elevation of plasma glucose after an oral glucose load and increased the glucose infusion rate (GIR) during the euglycemic insulin-glucose clamp test at a dose of 0.1 g/kg or higher compared with the vehicle control. Furthermore, EPA-E significantly and dose-dependently ameliorated coagulation-related parameters, including the prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen level, and factor II, V, VII, VIII, IX, X, XI, and XII and antithrombin III (AT III) activities, and fibrinolysis-related parameters, including plasminogen, tissue-type plasminogen activator (t-PA), alpha2-plasmin inhibitor (alpha2-PI), and plasminogen activator inhibitor (PAI), and also suppressed ADP- or collagen-induced platelet aggregation and the cholesterol to phospholipid (C/P) molar ratio in platelet membranes at a dose of 0.1 g/kg or higher. These data demonstrate multiple actions of the product in these laboratory animals. These include changes in platelet function, coagulation/fibrinolysis factors, plasma immunoreactive insulin secretion, and plasma glucose/insulin resistance.

Age-related changes in coagulation, fibrinolysis, and platelet aggregation in male WBN/Kob rats

We investigated the age-related changes in blood coagulation, fibrinolysis, and platelet aggregation in male WBN/Kob rats, animals that exhibit spontaneously diabetes mellitus at more than 6 months of age. The rats aged 6 months or more showed significant hyperglycemia, hypoinsulinemia, and hyperlipidemia. As changes in coagulation parameters, the data indicated significant increases in factors II, V, VII, VIII, IX, X, and XII activities; a significant decrease in antithrombin III activity in rats more than 6 months of age; significant increases in fibrinogen level and factor XI activity; and significant decreases in prothrombin time and activated partial thromboplastin time in those more than 9 months of age. As changes in fibrinolytic parameters, the animals showed significant decreases in plasminogen and tissue-type plasminogen activator, and significant increases in alpha2-plasmin inhibitor and plasminogen activator inhibitor at more than 6 months of age. In addition, there were significant correlations between the plasma levels of coagulation/fibrinolytic markers and the 4-hour fasting glucose or lipids. Furthermore, they displayed significant increases in ADP- or collagen-induced platelet aggregation and in cholesterol/phospholipid molar ratio in platelets at more than 9 months of age. The increase in cholesterol/phospholipid ratio may be responsible for hyperaggregation of platelets in diabetic animals. These findings suggest that WBN/Kob rats are suitable for research on blood coagulation abnormalities in diabetes. However, further studies are needed to clarify the details of the mechanisms involved.

D0870, an antifungal agent, induces reverse use-dependent QT prolongation in dogs

We previously reported that D0870 induced QT prolongation and sudden death due to torsades de pointes (TdP) in dogs and that catecholamines played an important part in the development of the sudden death. In the present study, we analyzed in detail the ambulatory electrocardiographic recordings obtained from the just-mentioned study to elucidate the mechanism of the onset of TdPs and conducted an in vitro study using isolated canine Purkinje fibers to assess the effect of D0870 on repolarization. The hearts with TdPs observed before the sudden death showed a higher sinus rate for 5 and 10 sec before the onset, a shorter coupling interval, and a higher ventricular tachycardia rate compared with those having the non-sustained TdPs. These findings suggest that D0870-induced fatal TdPs may be provoked by a triggered activity developed from delayed after depolarizations. In contrast, as the pause-dependent, non-sustained TdPs in bradycardia showed a typical "short-long-short" sequence, they may be developed from early afterdepolarization . Moreover, the results of the in vitro study supported our contention that D0870 induced QT prolongation in a reverse use-dependent manner in vivo and suggested that it may inhibit not only rapidly activating delayed rectifier potassium current (Ik(r)) but also L-type Ca current (I(ca-L)).

Influences of catecholamines on the sudden death induced in dogs by an antifungal agent, D0870

We previously reported the occurrence of QT prolongation and sudden death owing to torsades de pointes (TdP) in dogs treated with D0870, an antifungal agent. In the present study, we evaluated the influences of epinephrine and isoproterenol on the onset of TdP each time D0870 was given to 6 anesthetized open-chest dogs at a dosage of 20 mg/kg, 5 times every 40 minutes, by the simultaneous measurements of surface electrocardiogram and epicardial monophasic action potential (MAP). D0870 alone induced noticeable prolongation of the QT interval and action potential duration (APD), but neither ventricular premature contraction (VPC) nor sudden death. In contrast, the additional administration of the catecholamines induced a greater shortening of APD during the later phase of repolarization than during its earlier one and VPCs in all dogs tested, and sudden deaths owing to TdPs in 4 of the 6 dogs treated with D0870. These results suggest that D0870 alone does not induce TdP but that catecholamines play an important part in the development of sudden death induced by D0870 in dogs.

Effect of ACTH on renal excretion of purine bases in a patient with isolated ACTH deficiency

We investigated the renal transport of purine bases (uric acid, hypoxanthine and xanthine) after rapid and continuous ACTH loading tests in a patient with isolated ACTH deficiency, a rare cause of secondary adrenocortical insufficiency. Plasma uric acid concentration and the urinary ratio of uric acid/creatinine did not change in the rapid ACTH test, which did not increase plasma cortisol concentration. In the continuous ACTH loading test, the plasma concentration of uric acid and oxypurines (hypoxanthine and xanthine) decreased, and the urinary excretion and fractional clearance of them increased as well as the plasma concentrations and urinary excretion of cortisol. These findings suggest that glucocorticoid directly affects the common renal transport pathway for uric acid, hypoxanthine, and xanthine.

Suicidal insulin overdose in a type 1 diabetic patient: relation of serum insulin concentrations to the duration of hypoglycemia

We present a case of a 31-year-old Type 1 diabetic woman who self-administered 2400 units of insulin mixture (70% NPH human insulin and 30% Regular human insulin) as a suicidal attempt. The subsequent hypoglycemia was prolonged probably due to delayed absorption of the subcutaneous insulin, but it was not very difficult to control despite the administration of large amounts of insulin. Although the estimated serum insulin level was not well correlated with the severity of hypoglycemia, the hypoglycemia subsided when the serum insulin level returned to the physiological level. Therefore, the study of insulin pharmacokinetics after insulin overdose may be useful to know the necessary duration of exogenous glucose administration required to manage the medical emergency of severe insulin intoxication in future cases.

Dienogest, a synthetic steroid, suppresses both embryonic and tumor-cell-induced angiogenesis

Orally administered dienogest (17alpha-cyanomethyl-17beta-hydroxy-estra-4,9-diene-3-one) is efficacious against human hormone-dependent cancer xenografts in severely immunodeficient mice and in rats with experimental endometriosis, but its mechanisms of action remain unclear. We assessed the effect of dienogest on angiogenesis, because these two diseases that are sensitive to dienogest are known to be angiogenesis-dependent. Topical dienogest treatment dose-dependently inhibited embryonic angiogenesis, the ID(50) value being 6.4 nmol/egg. Oral administration of dienogest (1 mg kg(-1) day(-1)) for 5 consecutive days significantly suppressed angiogenesis induced by S-180 mouse tumor cells in the mouse dorsal air sac assay. In vitro experiments showed that dienogest at concentrations up to 10 microM had little or no effect on the proliferation of plasminogen activator activity or formation of tube-like structures by microvascular endothelial cells. These results suggest that dienogest is a new, orally active antagonist of angiogenesis, and that its anti-angiogenic action may be involved in its therapeutic effects on cancer xenografts and endometriosis that we observed previously.

Effect of highly purified eicosapentaenoic acid ethyl ester on insulin resistance and hypertension in Dahl salt-sensitive rats

We investigated the effect of long-term administration of highly purified eicosapentaenoic acid ethyl ester (EPA-E), an n-3 polyunsaturated fatty acid derived from fish oil, in comparison to lard on the development of hypertension and insulin resistance in Dahl salt-sensitive (Dahl-S) rats fed a high-sucrose diet (HSD), a model of salt-sensitive hypertension. After 16 weeks of treatment, the glucose infusion rate (GIR) during the euglycemic insulin-glucose clamp test significantly increased in the HSD-EPA-E group compared with the HSD-water or -lard control group. The GIR was approximately three times higher in the HSD-EPA-E group versus the HSD-water or -lard control group, and it was about 70% of the rate in the calorically deprived control group fed a low-fat-high-fiber diet (LF-HFD). In addition, EPA-E significantly suppressed the elevation of plasma glucose and insulin levels after oral glucose loading. These results indicate that EPA-E prevents the development of insulin resistance in Dahl-S rats fed a HSD. Fatty acid analysis of phospholipids in skeletal muscle showed a significant increase in C18:2, C20:5, and C22:5 components in the HSD-EPA-E group and, conversely, a significant decrease in C16:0, C20:4, and C22:6. The present results indicate that the beneficial effect of EPA-E on insulin resistance in Dahl-S rats fed a HSD is likely dependent on the modification of phospholipid components in the skeletal muscle membrane. These findings suggest that EPA-E might prevent the development of insulin resistance in dietary obesity. In addition, the HSD-EPA-E group showed a significant increase in the level of uncoupling protein (UCP) in brown adipose tissue as compared with the HSD-water or -lard control group. However, EPA-E had no effect on the development of hypertension and obesity in Dahl-S rats fed the HSD.

Human natural tumor necrosis factor alpha induces multiple endocrine and hematologic disorders in rats

Slc:Wistar male rats treated with human natural tumor necrosis factor alpha (hn TNF-alpha, 3 X 10(5) Japan reference units/kg intravenously) for 3 months showed histologic vacuolation of basophils in the anterior pituitary, hyperplasia of the thyroidal follicular epithelium, and hyperplasia of the testicular interstitial cells. The vacuolated basophils were immunohistochemically shown to be thyrotrophs. In addition, there were decreases in plasma levels of triiodothyronine (T3), thyroxin (T4), and testosterone, and an increase in thyroid-stimulating hormone (TSH). The number of lymphocytes in the marginal zones of lymphoid follicles in spleen and lymph nodes and B-lymphocytes in the peripheral blood decreased. Hyperplasia of hematopoietic cells in the bone marrow and decreases in both leukocytes and erythrocytes in the peripheral blood were prominent. Hyperplasia of bile ductular epithelial cells with periportal mononuclear cell infiltration in the liver and increased cellularity in alveolar walls in the lung were also characteristic. In in vitro studies, hn TNF-alpha inhibited both proliferation and peroxidase activity of thyroid follicular epithelial cells. These findings demonstrate that hn TNF-alpha may induce histologic vacuolation of thyrotrophs by causing a decrease in plasma levels of T3 and T4; hyperplasia of the thyroid follicular epithelium, which may be attributed to the increased plasma level of TSH; hyperplasia of testicular interstitial cells, by lowering the plasma level of testosterone; hyperplasia of bile ductular epithelial cells; hyperplasia of hematopoietic cells in bone marrow; and the increase in cellularity in pulmonary alveolar walls. In addition, hn TNF-alpha may suppress the differentiation of B-lymphocytes.

Acute toxicity of an anti-Fas antibody in mice

By histopathologic examination of various organs in 3 normal strains, C3H/HeN, ICR, and DBA/1J, of mice treated intravenously once with anti-Fas antibody (Jo2), we failed to determine any target organ, except the liver, responsible for the acute lethality induced by the Fas/anti-Fas antibody interaction. However, we could show the presence of Fas-mediated apoptosis in other organs aside from the liver and normal mouse strain differences in susceptibility to anti-Fas antibody. Among these strains, C3H/HeN was the most susceptible to the antibody, followed by ICR and DBA/1J. We observed Fas-mediated apoptosis in the liver, spleen, thymus, lymph nodes, Peyer's patch, intestine, skin, coagulation glands, ovary, uterus, and vagina in all 3 strains and additionally in the epididymides and seminal vesicles in the DBA/1J strain. We also demonstrated that Fas-mediated apoptosis of small lymphocytes in the mantle zone of splenic lymphatic follicles preceded that of the hepatocytes or thymic cells. Since cellular damage was most severe in the liver among all the apoptotic organs in the 3 mouse strains, liver injury induced by anti-Fas antibody is speculated to play a significant role in the death.

A case of classical xanthinuria (type 1) with diabetes mellitus and Hashimoto's thyroiditis

In a 62-year-old woman with non-insulin-dependent diabetes mellitus and Hashimoto's thyroiditis, hypouricemia was detected by a routine examination. Her plasma uric acid level was markedly low and urinary excretion of uric acid was undetectable. The high plasma and urine levels of xanthine were observed, although those of hypoxanthine were within normal ranges at rest after an overnight fast. After taking diet, plasma concentration and urinary excretion of hypoxanthine were markedly increased together with those of xanthine. The xanthine oxidase activity of duodenal mucosa was below the limits of detection. Allopurinol was metabolized to oxypurinol and pyrazinamide to 5-hydroxypyrazinamide in spite of no activity of xanthine oxidase, suggesting that aldehyde oxidase converted allopurinol to oxypurinol and pyrazinamide to 5-hydroxypyrazinamide. Based on these findings, she was diagnosed as having a subtype of classical xanthinuria type 1 with the normal plasma concentration of hypoxanthine in fast.

Silver and thallium(I) complexation with dibenzo-16-crown-4

Dibenzo-16-crown-4 (1) indicates high silver and thallium(I) ion selectivity over sodium, potassium, and rubidium ion evaluated from the solvent extraction of metal picrates, while its cation-binding ability is lower than those of dibenzo-18-crown-6 (2) and dibenzo-22-crown-6 (3). Taking account of the highest thallium(I) ion selectivity for 1 obtained from extraction experiments, PVC membrane thallium(I)-selective electrodes based on 1 are prepared. The electrode shows the best potentiometric selectivity coefficients for thallium(I) over potassium and rubidium than those of 2 and 3, and commercially available bis(crown ether)s (4).

QT prolongation and torsades de pointes induced by an antifungal agent, D0870, in conscious dogs

D0870 ((R)-2-(2,4-difluoro-phenyl)-1-[3-[(E)-4-(2,2,3,3-tetrafluoropropoxy+ ++)-styryl]-1H-1,2,4-triazol-1-yl]-3-(1H-1,2,4-triazole-1-yl) propan-2-ol), a novel bis-triazole antifungal agent, induced sudden deaths at a high dose of 5 mg/kg/day in a 6-month toxicity study in dogs. In the present study, we intended to elucidate the cause of the sudden death in dogs. When used in a single dose, D0870 induced prolongation of QTc intervals in proportion to its plasma concentration, and the threshold plasma concentration of the drug causing 10% QTc prolongation was estimated to be 3.8 microg/ml. Then, we conducted a study to induce sudden death in dogs using loading (50 mg/kg) and maintenance (5 mg/kg/day) doses with long-term ambulatory electrocardiographic monitoring. Marked QTc prolongation (52-96%), ventricular premature contractions, and T-wave alternans were observed in all 10 animals treated with the drug, and seven out 10 animals died of ventricular fibrillation (VF) associated with torsades de pointes (TdP) when the dogs were treated with D0870 for 14 or 16 days. The TdPs were elicited in both tachycardia and bradycardia, and some of them in the former proceeded to VF. Consequently, we clarified that D0870-induced sudden death is primarily attributable to the development of TdP preceding VF and may be enhanced by sympathetic nervous tone produced by emotional or physical stress.

Effect of dienogest on bleeding time, coagulation, fibrinolysis, and platelet aggregation in female rats

We investigated the effect of dienogest on bleeding time, coagulation, fibrinolysis, and platelet aggregation in female rats compared with that of medroxyprogesterone acetate (MPA) and danazol, in order to elucidate the reason for relatively high incidence of bleeding in dienogest-treated patients with endometriosis. Dienogest caused no change in the bleeding time at a single dose of 100 mg/kg or at a repeated dose of 10 mg/kg per day for 2 weeks. The drug increased the fibrinogen level, coagulation factor II and V activities, and antithrombin III activity, but had no effect on fibrinolysis or on platelet aggregation at repeated doses of 1 and 10 mg/kg per day for 4 weeks. MPA significantly shortened the bleeding time at the same doses as dienogest. MPA increased the fibrinogen level and plasminogen activity, potentiated the platelet aggregation, and increased the platelet cholesterol-to-phospholipid ratio at a repeated dose of 10 mg/kg per day for 4 weeks. Danazol significantly shortened the bleeding time like MPA. Danazol increased the fibrinogen level, coagulation factor II, V, VII, VIII, IX, X, XI, and XII activities, and antithrombin III activity, but had no influence on the platelet aggregation at repeated doses of 10 and 100 mg/kg per day for 4 weeks. In comparison with MPA and danazol, dienogest may induce a relatively high incidence of bleeding in patients with endometriosis partially because of its minimal effect on hemostasis.

Histopathological and biochemical studies on pancreatic fibrosis in WBN/Kob rats

We investigated the time-course of changes in pancreatic fibrosis accompanied with pancreatitis in WBN/Kob rats. The areas of fibrosis and fatty replacement were analysed morphometrically, and biochemical measurements of pancreatic and plasma prolyl hydroxylase and of pancreatic collagenase were assessed. Male rats showed acute pancreatitis at 2-3 months of age, lesions that later underwent a transition to widespread fibrosis. The fibrosis then decreased, and the fibrotic tissue was replaced with adipose tissue. Morphometrically, the fibrotic area reached its maximal size when the rats were 4 months old, diminishing thereafter. The fibrosis occurred mainly in the intralobular space, and was principally attributable to type-III collagen. Type-I collagen scarcely appeared throughout the experimental period. Alpha-Smooth muscle actin appeared in and around myofibroblasts that developed in an early stage and diminished later in accordance with the progressive manner of fibrosis. The plasma prolyl hydroxylase level was higher in males than in females from 4 through 10 months of age. Pancreatic collagenase activity in the males also increased during the same period. These findings suggest that pancreatic fibrosis in male WBN/Kob rats is affected by the balance between prolyl hydroxylase and collagenase.

Protection against preterm delivery in mice by urinary trypsin inhibitor

OBJECTIVE

To investigate the precise mechanism by which urinary trypsin inhibitor suppresses cytokine production in the prevention of preterm delivery.

METHODS

In vivo and in vitro studies were performed using ascites and peritoneal macrophages obtained on day 15 of pregnancy from female C3H/HeN mice that had been impregnated by B6D2F1 male mice. Lipopolysaccharide receptor, the intracellular signal transduction system, and nuclear factor-kappaB level were examined.

RESULTS

In the in vivo study, we found that urinary trypsin inhibitor ameliorated the deterioration of intraperitoneal conditions induced by lipopolysaccharide (ie, increases in ascitic volume, peritoneal cell count, and tumor necrosis factor-alpha level) and caused a decrease in the binding of lipopolysaccharide to mouse macrophages. In the in vitro studies, urinary trypsin inhibitor decreased the binding capacity of lipopolysaccharide for its receptor, blocked the intracellular signal transduction induced by lipopolysaccharide, and decreased the nuclear factor-kappaB level. Increases were induced in the binding capacity of the macrophages for urinary trypsin inhibitor and its incorporation into them in the presence of lipopolysaccharide.

CONCLUSION

We postulate that urinary trypsin inhibitor may suppress the production of inflammatory cytokines induced by lipopolysaccharide in mouse peritoneal macrophages through suppression of the lipopolysaccharide receptor, inhibition of the intracellular signal transduction system, and decrease in the nuclear factor-kappaB level.

Effects of dienogest (a synthetic steroid) on coagulation, fibrinolysis, and platelet aggregation in female monkeys

We investigated the effects of dienogest (0.1-10 mg/kg per day, p.o.) on coagulation, fibrinolysis and platelet aggregation in female rhesus monkeys. Then, we also examined those of medroxyprogesterone acetate (MPA, 10 mg/kg per day, p.o.) or danazol (10-1000 mg/kg per day, p.o.) on these parameters in the same species. In addition, we assessed the effects of dienogest (1 and 3 mg/kg per day, p.o.) or MPA (10 mg/kg per day, p.o.) on platelet aggregation and platelet lipids in female cynomolgus monkeys. At doses of 0.3 mg/kg or greater, dienogest increased the levels of several coagulation and anticoagulation factors, but had no effect on the prothrombin time, activated partial thromboplastin time, fibrinolysis, or platelet aggregation. MPA (10 mg/kg) had no effect on coagulation or fibrinolysis, but significantly potentiated platelet aggregation in response to ADP and collagen and also increased the platelet cholesterol-to-phospholipid ratio. Danazol (10 mg/kg or more) increased the activities of coagulation factors V, VII, VIII, X, XI, and XII in comparison to dienogest and MPA. Consequently, dienogest caused less potentiation of platelet aggregation than MPA and less potentiation of coagulation than danazol.

Tocolytic effect of magnesium sulfate and/or urinary trypsin inhibitor against lipopolysaccharide-induced preterm delivery in mice

BACKGROUND

The purpose of this investigation was to evaluate the effect of magnesium sulfate (magnesium) alone or along with urinary trypsin inhibitor (UTI) in a mouse model in the prevention of preterm delivery.

METHODS

On day 17 of pregnancy, female C3H/HeN mice impregnated by male B6D2F1 mice were given two intraperitoneal injections of lipopolysaccharide (LPS; 50 microg/kg) at a 3-hour interval, which treatment induced a 100% incidence of preterm delivery within 25 hours of the second dose. Magnesium (4, 5, 6, 7, or 8 mg/hr, s.c.), UTI (25 x 10(4) units/kg, i.p.), magnesium (5 mg/hr, s.c.) plus UTI (25 x 10(4) units/kg, i.p.), saline solution (0.3 ml/hr, s.c.), or saline solution (0.1 ml/hr, s.c. and 2.5 ml/kg, i.p.) was administered to pregnant animals on day 18 of gestation. UTI was intraperitoneally given 5 times at 2-hour intervals from 8:00 am to 4:00 pm, and magnesium was infused subcutaneously and constantly from 8:00 am to 6:00 pm. In addition, the preventive effect of magnesium on LPS-induced contraction of uterine muscle strips and that of magnesium, UTI, or magnesium plus UTI on LPS-induced calcium influx in uterine smooth muscle cells were examined using muscle tissue isolated from pregnant mice on day 17 of gestation.

RESULTS

The incidence of preterm delivery decreased significantly in a dose-dependent fashion with magnesium treatment, and there was a significant and synergistic decrease after combined treatment with magnesium plus UTI. The in vitro uterine contraction and calcium influx induced by LPS were significantly suppressed by magnesium. The latter was significantly suppressed by UTI and additively reduced by magnesium plus UTI.

CONCLUSIONS

Combination therapy with magnesium plus UTI may possibly be helpful for preventing preterm delivery in humans without the severe side effects induced by hypermagnesemia.

Lipoteichoic acid induces preterm delivery in mice

The purpose of this study was to determine whether or not lipoteichoic acid (LTA) could induce preterm delivery in mice. On days 15 and 17 of pregnancy, female C3H/HeN mice impregnated by male B6D2F1 mice were given intraperitoneal injections of LTA (12.5-75 mg/kg, single dose or repeated doses at a 3-h interval). We examined the changes in cervix, placental trophoblasts, and plasma and amniotic fluid concentrations of interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) after dosing with LTA. In addition, the effect of LTA on the contraction of isolated uterine muscle from pregnant mice was also measured. The incidence of preterm delivery was highest (100%), when the pregnant animals were treated with 75 mg/kg LTA twice on day 15 of pregnancy or with 25 mg/kg LTA twice on day 17 of pregnancy. LTA-accelerated cervical ripening and placental abruption preceding the onset of preterm delivery, as well as increased plasma and amniotic fluid concentrations of IL-1alpha, IL-6, and TNF-alpha. Also, LTA increased contraction of uterine muscle strips. In conclusion, LTA induced preterm delivery in mice in the same manner as lipopolysaccharide (LPS), but the effective dose of LTA was larger than that of LPS.

Effects of dienogest, a synthetic steroid, on experimental endometriosis in rats

OBJECTIVE

Dienogest, a synthetic steroid with progestational activity, is used as a component of oral contraceptives and is currently being evaluated clinically for the treatment of endometriosis. The present study was conducted to confirm the effects of dienogest on experimental endometriosis in rats and to elucidate its mechanism of action.

DESIGN

Experimental endometriosis induced by autotransplantation of endometrium in rats.

METHODS

Endometrial implants, immune system, and bone mineral were investigated after 3 weeks of medication.

RESULTS

Dienogest (0.1-1 mg/kg per day, p.o.) reduced the endometrial implant volume to the same extent as danazol (100 mg/kg per day, p.o.). Simultaneously, dienogest ameliorated the endometrial implant-induced alterations of the immune system: i.e. it increased the natural killer activity of peritoneal fluid cells and splenic cells, decreased the number of peritoneal fluid cells, and decreased interleukin-1beta production by peritoneal macrophages. In contrast, danazol (100 mg/kg per day, p.o.) and buserelin (30 microg/kg per day, s.c.) had none of these immunologic effects. Additionally, combined administration of dienogest (0.1 mg/kg per day) plus buserelin (0.3 microg/kg per day) suppressed the bone mineral loss induced by buserelin alone, with no reduction of the effect on endometrial implants. In vitro studies on dienogest revealed an antiproliferative effect on rat endometrial cells due to inhibition of protein kinase C activity plus a partial progestational effect.

CONCLUSIONS

Dienogest appears to be a potent agent with mechanisms of action different from those of danazol and GnRH agonists currently available for the treatment of endometriosis.

Influence of highly purified eicosapentaenoic acid ethyl ester on insulin resistance in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous non-insulin-dependent diabetes mellitus

We investigated the effect of long-term administration of highly purified eicosapentaenoic acid ethyl ester (EPA-E), an n-3 polyunsaturated fatty acid derived from fish oil, in comparison to the effects of lard, olive oil, safflower oil, or distilled water as the control on the development of insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of spontaneous non-insulin-dependent diabetes mellitus (NIDDM) with obesity. After 17 or 18 weeks of treatment, the glucose infusion rate (GIR) in the euglycemic insulin-glucose clamp test only showed a significant increase in EPA-E-treated rats compared with control rats given distilled water alone as the vehicle. The GIR in EPA-E-treated animals was approximately three times greater than in the controls. This is the first report to display the influence of various fatty acids on the development of insulin resistance in OLETF rats. We demonstrated that EPA-E prevents the onset of insulin resistance, whereas olive oil and safflower oil have no effect and lard exacerbates insulin resistance. Fatty acid analysis of phospholipids in skeletal muscle showed a significant increase of the C18:2, C20:5, and C22:5 components in EPA-E-treated rats and, conversely, a significant decrease in C20:4. In addition, EPA-E-treated rats showed a significant increase in GLUT4 mRNA in skeletal muscle when compared with control rats. Our results indicate that the beneficial effect of EPA-E on insulin resistance in OLETF rats is likely to be dependent on modification of the phospholipid components of the skeletal muscle membrane. These findings suggest that dietary fatty acids may play a key role in the development of insulin resistance in patients with NIDDM.

QT corrected for heart rate and relation between QT and RR intervals in beagle dogs

The beagle dog has been widely used in cardiovascular research, but the adequacy of QT prediction formulas in dogs over a wide range of RR intervals has not been evaluated sufficiently. We investigated the QT-RR relation in beagles by analysis of the QT and preceding RR intervals obtained from 24-h ambulatory electrocardiograms. The acceptability of 14 QT prediction formulas was evaluated by use of 100-150 selected pairs of QT-RR points per animal in seven male and seven female beagles. The accuracy of fit with the measured data was assessed according to the minimum Akaike information criterion. The best fit was given by the logarithmic and inverse Kovács' formulas among one- and two-parameter linear regression equations, respectively. Exponential formulas produced a better fit than did the linear regression formulas, but are impractical because of the complicated interpretation of parameters due to the nonlinearity. In addition, the results obtained under physiological conditions were also confirmed by those of the pharmacological intervention study with disopyramide. Consequently, we propose a one-parameter logarithmic formula (QTc= log600 x QT/logRR) for correcting the QT interval for a heart rate of 100 bpm and the inverse Kovács' formula for evaluating a reverse-use-dependency of QT prolongation.

Animal studies on the endocrinological profile of dienogest, a novel synthetic steroid

Dienogest is an orally active synthetic steroid that is used for contraception and is currently being studied for the possible treatment of endometriosis. Earlier we demonstrated that dienogest had therapeutic effects on experimental endometriosis in rats and that its mechanisms of action were different from those of drugs currently on the market for the treatment of endometriosis. We also reported preclinically that dienogest showed a potential anticancer action against hormone-dependent cancers that was different from that of progestins. Accordingly, we obtained preclinical background data for the above-described clinical applications and extension of the clinical use of the drug in the near future by investigating the endocrinological profile of dienogest in rabbits and rats. Dienogest was characterized by having a moderate binding affinity for progesterone receptors and by progestational activities: it stimulated endometrial proliferation (> or = 0.01 mg/kg) that was only partially inhibited by RU-486, and induced carbonic anhydrase activity in endometrium (> or = 0.01 mg/kg). Also, it was slightly uterotrophic (> or = 1 mg/kg) with very low binding affinity for oestrogen receptors but without biological androgenic and anabolic activities (100 mg/kg), with neither glucocorticoid activity nor mineralocorticoid activity (100 mg/kg), and with very slight binding affinity for human sex hormone-binding globulin. These findings suggest that dienogest is not a pure progestin and appears to induce fewer side effects than drugs currently on the market for the treatment of endometriosis.

Preventive effect of ritodrine hydrochloride and/or urinary trypsin inhibitor against lipopolysaccharide-induced preterm delivery in mice

BACKGROUND

The purpose of this study was to confirm the preventive effect of ritodrine hydrochloride (ritodrine) alone or ritodrine plus urinary trypsin inhibitor (UTI) in a mouse model of preterm delivery.

METHODS

On day 17 of pregnancy, female C3H/HeN mice impregnated by male B6D2F1 mice were given two intraperitoneal injections of lipopolysaccharide (LPS) (50 micrograms/kg) at a 3-hour interval, which induced a 100% incidence of preterm delivery within 25 hours of the second dose. Ritodrine (1, 3, or 10 mg/kg, p.o.), UTI (25 X 10(4) units/kg, i.p.), ritodrine (3 mg/kg, p.o.) plus UTI (25 x 10(4) units/kg, i.p.), distilled water (10 ml/kg, p.o.), or distilled water (10 mg/kg, p.o.) plus saline solution (10 ml/kg, i.p.) were administered to the pregnant animals 10 times at 1-hour intervals from 8:00 AM to 5:00 PM on day 18 of pregnancy. In addition, the preventive effect of ritodrine, UTI, or ritodrine plus UTI was examined on LPS-induced contraction of uterine muscle strips isolated from pregnant mice on day 17 of gestation.

RESULTS

The incidence of preterm delivery decreased significantly in a dose-dependent fashion with ritodrine treatment, and there was a significant and synergistic decrease after combined treatment with ritodrine plus UTI. The in vitro uterine contraction induced by LPS was significantly suppressed by both ritodrine and UTI.

CONCLUSIONS

Combination therapy with ritodrine plus UTI may be helpful for preventing preterm delivery in humans without the cardiovascular side effects that often accompany treatment with ritodrine alone.

Trophoblastic apoptosis in mice with preterm delivery and its suppression by urinary trypsin inhibitor

OBJECTIVE

To investigate histopathologic changes of the placenta in mice with preterm delivery induced by lipopolysaccharide and the effect of urinary trypsin inhibitor.

METHODS

Female C3H/HeN mice impregnated by male B6D2F1 mice were treated with lipopolysaccharide (50 micrograms/kg, intraperitoneally) or lipopolysaccharide plus urinary trypsin inhibitor (25 x 10(4) U/kg, intraperitoneally). At 3, 6, 9, and 18 hours after the second dose of lipopolysaccharide, and at delivery in the control and urinary trypsin inhibitor-treated groups, the concentrations, of interleukin-1 alpha and tumor necrosis factor-alpha were determined in serum and amniotic fluid. Subsequently, the placentas were examined. In the same manner, we examined mice treated with interleukin-1 alpha (250 micrograms/kg, subcutaneously) on day 15 of pregnancy and intact mice on days 15 and 18 of pregnancy as well as at delivery. To assess the direct action of cytokines, we cultured placental slices with tumor necrosis factor-alpha, interleukin-1 alpha, or tumor necrosis factor-alpha plus urinary trypsin inhibitor and examined them morphologically.

RESULTS

Control mice were characterized by trophoblastic apoptosis and increased serum levels of tumor necrosis factor-alpha and interleukin-1 alpha. In contrast, urinary trypsin inhibitor-treated mice showed suppression of apoptosis and lower cytokine levels. Interleukin-1 alpha induced trophoblastic apoptosis and increased the serum level of tumor necrosis factor-alpha. The in vitro study showed that tumor necrosis factor-alpha directly induced trophoblastic apoptosis in placental slices.

CONCLUSION

We demonstrated that trophoblastic apoptosis occurs in the placentas of a mouse model with preterm delivery induced by lipopolysaccharide. We postulated that apoptosis may lead to placental abruption, and its development may be prevented by treatment with urinary trypsin inhibitor.

Ability of intrauterine bacterial lipopolysaccharide to cause in situ uterine contractions in pregnant rabbits

BACKGROUND

To investigate the ability of bacterial lipopolysaccharide delivered by the intra-uterine route to cause uterine contractions in rabbits, and to assess the suppressive effect of urinary trypsin inhibitor on them.

METHODS

Both pregnant and non-pregnant rabbits were chronically implanted with a force-transducer to make it possible to record isometric uterine contractions under unanesthetized and unrestrained conditions. Lipopolysaccharide (10 micrograms/animal) was administered via a catheter to their uteri; and then, after confirmation of lipopolysaccharide-induced uterine contractions, urinary trypsin inhibitor (3,000 or 10,000 units/animal/time) or saline solution was injected through the catheter, 5 times for pregnant animals or 3 times for non-pregnant animals at 1-hour intervals in both cases. Their uterine contractions were continuously recorded for 3 to 5 hours. Effects of lipopolysaccharide (10 micrograms/ml) and urinary trypsin inhibitor (100 and 1,000 units/ml) on the contraction of isolated uteri from pregnant mice were also measured, as was their production of prostaglandin E2 and prostaglandin F2 alpha by an enzyme immunoassay method.

RESULTS

Lipopolysaccharide augmented the in situ uterine contractions in both pregnant and non-pregnant rabbits, as well as the in vitro contractions of isolated uteri from pregnant mice. Lipopolysaccharide also increased the uterine prostaglandin production. Urinary trypsin inhibitor inhibited significantly the lipopolysaccharide-induced uterine contractions and the prostaglandin production.

CONCLUSIONS

Lipopolysaccharide enhanced uterine contractions through, at least partly, a direct mechanism via uterine prostaglandin production, which action could explain the onset of preterm delivery due to intrauterine bacterial infection. As urinary trypsin inhibitor suppressed the lipopolysaccharide-induced uterine contractions, this inhibitor may be a hopeful candidate of a drug for prevention of preterm delivery.

Dienogest, a novel synthetic steroid, overcomes hormone-dependent cancer in a different manner than progestins

BACKGROUND

Dienogest is a synthetic progestational steroid that is used for contraception. It is being studied for the treatment of endometriosis, but its anticancer activity remains unknown. The authors investigated the anticancer effect of dienogest on hormone-dependent cancers.

METHODS

The authors used two cell lines derived from human endometrial carcinoma (HEC-88nu cells expressing estrogen receptors [ER] but not progesterone receptors [PR] and Ishikawa cells expressing both ER and PR) and a cell line derived from human breast carcinoma (MCF-7 cells expressing both ER and PR). The authors examined the in vivo antitumor activity and the antiuterotropic activity of dienogest in mice and compared it with the activity of several progestins.

RESULTS

At oral doses of 0.01-1 mg/kg/day, dienogest significantly suppressed the 17 beta-estradiol benzoate (E2)-dependent tumor growth of HEC-88nu cells, which were unresponsive to known progestins such as medroxyprogesterone acetate (MPA, 100 mg/kg/day, administered orally) and norethisterone (NES, 100 mg/kg/ day, administered orally). The suppressive effect of dienogest on tumor growth was not diminished in the presence of excess MPA. Dienogest also suppressed the E2-dependent tumor growth of both Ishikawa and MCF-7 cells, both of which responded to MPA. However, the minimum effective dose of dienogest (0.01-1 mg/kg/day) was much lower than that of MPA (100 mg/kg/day). In contrast, dienogest did not suppress the E2-induced increase in uterine weight, whereas MPA and NES suppressed it significantly.

CONCLUSIONS

Dienogest showed potent anticancer activity against hormone-dependent cancers at doses at which progestins show no activity.

Role of urinary trypsin inhibitor in the maintenance of pregnancy in mice

OBJECTIVE

To investigate the mechanisms whereby urinary trypsin inhibitor prevents lipopolysaccharide-induced preterm delivery in mice.

METHODS

On day 15 of pregnancy, C3H/HeNCrg female mice impregnated by Crg:B6D2F1 male mice were treated intraperitoneally with lipopolysaccharide (50 micrograms/kg, twice at a 3-hour interval) to induce preterm delivery. Urinary trypsin inhibitor (2.5 x 10(4), 7.5 x 10(4), or 25 x 10(4) units/kg, ten times at 1-hour intervals) or saline solution was administered intraperitoneally to the animals.

RESULTS

The incidence of preterm delivery was significantly decreased on a dose-related basis by urinary trypsin inhibitor treatment. Urinary trypsin inhibitor prevented the morphologic and functional changes in fetal membranes and cervical ripening preceding the onset of preterm delivery. Urinary trypsin inhibitor also suppressed the increase in plasma and amniotic fluid concentrations of interleukin-1 alpha, interleukin-6, and tumor necrosis factor-alpha after the lipopolysaccharide dosing in this animal model for preterm delivery.

CONCLUSION

Urinary trypsin inhibitor prevents the pathogenicity of preterm delivery through the suppression of cytokine production.

Usefulness of a new tactile sensor for measurement of uterine cervical ripening in mice in a quantitative and noninvasive manner

OBJECTIVE

The purpose of this study was to establish a method with a new tactile sensor for determining in a quantitative and noninvasive manner the extent of uterine cervical ripening.

STUDY DESIGN

We used a newly designed tactile sensor to measure the softness of the cervix in untreated nonpregnant, pregnant, parturient, and nursing mice and then on day 15 of gestation in pregnant mice treated with dehydroepiandrosterone sulfate or Escherichia coli lipopolysaccharide. Additionally, to elucidate the correlation between the extent of cervical softness and its morphologic changes, we observed microscopically the uterine cervices.

RESULTS

The hardness of the murine cervix decreased with the progression of pregnancy and became minimal at delivery. We demonstrated for the first time with a tactile sensor for measuring hardness that dehydroepiandrosterone sulfate and lipopolysaccharide significantly decreased the stiffness of the murine cervix. These findings were supported by the morphologic observations on the cervices.

CONCLUSIONS

These results show that the tactile sensor for measuring hardness makes it possible to determine the extent of cervical ripening quantitatively rather than qualitatively. We consider that cervical ripening determined objectively in this manner is a good parameter to predict the onset of preterm delivery.

Repeated administration of low-dose lipopolysaccharide induces preterm delivery in mice: a model for human preterm parturition and for assessment of the therapeutic ability of drugs against preterm delivery

OBJECTIVE

Our purpose was to establish a new animal model for human preterm delivery for assessment of the protective effect of drugs against preterm delivery.

STUDY DESIGN

C3H/HeN, C3H/HeN, and BALB/c female mice impregnated by C3H/HeN, B6D2F1, and B6D2F1 male mice, respectively, were treated intraperitoneally with Escherichia coli lipopolysaccharide (0 to 100 microgram/kg, single dose or repeated doses at 1- to 6-hour intervals) on days 12 through 17 of pregnancy. On day 15 of pregnancy, the C3H/HeN females that had been impregnated by B6D2F1 males and administered lipopolysaccharide were treated intraperitoneally with indomethacin (1000 microgram/kg), ritodrine hydrochloride (1000 microgram/kg), urinary trypsin inhibitor (25 x 10(4) units/kg), or gabexate mesylate (100 mg/kg); preterm or term delivery was recorded for these mice.

RESULTS

C3H/HeN females impregnated by B6D2F1 males revealed the highest (100%) incidence of preterm delivery when the females were treated with 50 microgram/kg lipopolysaccharide twice at a 3-hour interval on day 15 or 17 of pregnancy. Indomethacin and urinary trypsin inhibitor used separately significantly decreased the incidence of preterm delivery, but only urinary trypsin inhibitor, and not any of the other drugs, significantly increased the incidence of term delivery in the mice.

CONCLUSION

A new animal model for investigation of preterm delivery was established, and its usefulness for assessment of the protective effect of drugs against preterm delivery was demonstrated.

Thyroid hemiagenesis with subacute thyroiditis

A 58-year-old woman with thyroid hemiagenesis associated with subacute thyroiditis is described. Physical examinations revealed a firm nodule with spontaneous pain and tenderness in the left thyroid lobe. A serum thyroid hormone levels were elevated and thyroid scintiscan with 99mTc pertechnetate showed an extremely low uptake, we made a diagnosis of subacute thyroiditis. A 201Tl thyroid scan demonstrated an enlarged left lobe and absence of the right lobe. Ultrasonography of the thyroid gland revealed an enlarged left lobe occupied mostly with a hypoechoic region. An incidental finding was absence of the right lobe. Two months later thyroid function returned to normal. A follow-up thyroid scintiscan revealed a normal left lobe but absent right lobe. The diagnosis of hemiagenesis was confirmed by CT scan. This appears to be the first case report of thyroid hemiagenesis associated with subacute thyroiditis.

Simultaneous high-performance liquid chromatographic determination of 6 beta-hydroxycortisol and cortisol in urine with fluorescence detection and its application for estimating hepatic drug-metabolizing enzyme induction

A simple and sensitive high-performance liquid chromatographic method is described for the simultaneous determination of 6 beta-hydroxycortisol (6 beta-OHF) and cortisol (F) in urine. Urine (1 ml) containing fludrocortisone as the internal standard is extracted with ethyl acetate. The extract is washed successively with sodium hydroxide solution and water, and subsequently dried under a stream of nitrogen. The residue is redissolved in methanol. The 6 beta-OHF, F and fludrocortisone in the methanol solution are oxidized by cupric acetate and the resulting glyoxal compounds are converted into fluorescent derivatives with 1,2-diamino-4,5-methylenedioxybenzene (DMB). The DMB derivatives of the corticosteroids are separated within 70 min on a reversed-phase column, L-Column ODS, using stepwise elution with methanol-acetonitrile-0.5 M ammonium acetate and detected fluorimetrically at 350 nm (excitation) and 390 nm (emission). The lower limits of detection for 6 beta-OHF and F are 1.8 pmol (680 pg) and 2.4 pmol (950 pg)/ml urine (0.6 pmol and 0.8 pmol/100 microliters injection volume), respectively, at a signal-to-noise ratio of 3. This method can be applied to the determination of urinary 6 beta-OHF, and the ratio of 6 beta-OHF to F in humans and in rhesus monkeys treated orally with phenobarbital as a hepatic drug-metabolizing enzyme inducer.

[A case report of primary triple cancers in the thyroid, stomach and rectum with evidence of variable oncoprotein expressions]

A case with primary triple cancers including thyroid cancer is reported. A 57-year old woman complaining of laryngeal discomfort was found to have an firm elastic lump on the right anterior neck. On 123I scan, the nodule in the right thyroid lobe accumulated considerable amounts of radioiodine as a warm nodule, while the remainder of the gland showed decreased uptake. Thyroid hormone levels remained within normal ranges. Cytological findings obtained by fine-needle aspiration biopsy showed papillary carcinoma. Right lobectomy was performed. The histological examinations revealed papillary carcinoma embedded within adenomatous thyroid tissue. It is probable that the surrounding adenomatous tissue accumulated radioiodine, since the warm nodule on 123I scan was larger than the size of the carcinoma. Examinations of the gastrointestinal tract revealed the presence of poorly differentiated adenocarcinoma in the stomach and well differentiated adenocarcinoma (carcinoma in adenoma) in the rectum. Expressions of ras p21 and p53 were examined immunohistochemically in these carcinoma tissues. The ras p21 product was clearly detected in not only the thyroid carcinoma but in a part of the surrounding adenomatous regions as well. Both ras p21 and p53 proteins were observed in the rectal cancer tissue. In contrast, these oncoproteins were not found in the gastric cancer tissue. In this case ras oncogene activation may be an early event in the tumorigenic process of the thyroid and rectum. However, different genetic alterations seem to occur during the development of these three carcinomas.