A study on the effect of dehydroepiandrosterone sulfate on so-called cervical ripening

Dehydroepiandrosterone sulfate (DHAS) is now used for a dynamic test of placental function by many obstetricians. While practicing this test, the authors found that DHAS markedly promoted so-called "cervical ripening". To study this problem, DHAS of 50 or 100 mg in multiple doses were injected into 132 Japanese pregnant women in their 38th--42nd week of gestation. The change in Bishop score was carefully recorded. Bishop score in the injected groups of primiparae (100 mg) began to rise much sooner than the control groups (p less than 0.01 on seventh day and 14th day). However, such significant difference in the rise of Bishop score was not noted in the multiparae and primiparae with 50 mg. Although the rise of score is not significant, the duration (day) from injection to delivery was shorter in the injected group than the control group (t=2.1529, p less than 0.05 in primiparae with 50 mg, t=3.8829, p less than 0.01 with 100 mg, t=2.1029, p less than 0.05 in multiparae with 50 mg). In some of these cases, labor began or delivery was finished within 24 hrs. Among the factors of Bishop score, mainly the effacement, consistency and dilatation of the cervix were remarkably improved by DHAS injection (p less than 0.01 and less than 0.05). Side effects of any type were not seen in the mothers and foetuses. As a conclusion, DHAS injection in considered to produce favorable conditions for delivery in women with "unripe cervix" by softening the soft birth canal. Furthermore, it is suggested that DHAS might play an important role in triggering labor.

Distribution of 99mTc-1-thioglucose in rats: effect of administration route on pancreatic specificity

Tissue distribution of 99mTc-1-thioglucose was studied in inbred albino Fisher rats. High levels of radioactivity were observed in the kidney with concurrent low pancreatic levels and pancreas/liver ratios of 0.4 following intravenous administration of the agent. High pancreatic concentration were observed with pancreas/liver ratios of 4.0 after intraperitoneal administrations. Future studies on pancreatic radiopharmaceuticals should avoid production of artificially high pancreatic values by intraperitoneal injection.

Effect of hemolysin produced by Vibrio parahaemolyticus on membrane conductance and mechanical tension of rabbit myocardium

The mechanisms of the action of hemolysin extracted from Vibrio parahaemolyticus in the S-A node and right atrium cells of rabbit were studied by means of the single sucrose gap and isometric tension recording methods. Hemolysin caused the membrane to depolarize reversibly without affecting the action potential generating mechanism. Lowering of [Na+]o inhibited membrane depolarization in the presence of hemolysin while the readmission of normal Tyrode solution induced depolarization. Tetrodotoxin (TTX) barely antagonized the depolarizing action of hemolysin but slowed the rate of development of depolarization. Therefore, this depolarization is considered to be primarily due to the increase in conductance to Na which TTX may not block. The dose-response relationship was obtained by measuring a change in membrane resistance. The concentration necessary to yield one-half of the maximum reduction of the membrane was determined to by 7.5 micrograms/ml. Accumulation of Na within the cell may be responsible for an increase of twitch tension observed during the action of a low concentration of hemolysin. On the other hand, a higher concentration of hemolysin seemed to promote exchange of intracellar Na with extracellular Ca, especially when the Na concentration of the perfusing solution was reduced, and led to stronger contracture.

Isolation of a factor causing morphological changes of chinese hamster ovary cells from the culture filtrate of Vibrio parahaemolyticus

A factor changing Chinese hamster ovary cells from an oval to a spindle shape was isolated from the culture filtrate of Vibrio parahaemolyticus. It was partially purified by successive column chromatographies on diethylaminoethylcellulose, diethylaminoethyl-Sephadex A-25, hydroxylapatite, and Sephadex G-200. This factor was separated from thermostabl direct hemolysin and was heat labile.

Mean systemic pressure and mean pulmonary pressure: their effects on the total artificial heart

Mean systemic pressure (MSP) and mean pulmonary pressure (MPF), which are mean driving pressures for venous return in the natural heart, were studied in 11 calves in which the natural heart had been replaced with a total artificial heart (TAH). They were measured simply by stopping the artificial heart pumping. Although blood translocation from the arterial to the venous side was not performed, the eventual right and left atrial pressures reached six to eight seconds after stopping the TAH would represent MSP and MPP with reasonable accuracy. The MSP varied from nine to 3k mmHg (20+/-6 mmHg), whereas the MPP varied from nine to 39 mmHg (22+/-7 mmHg). The MSP varied in close relation to the right atrial pressure prior to cessation of the TAH (r=0.9124). Increases in RAP and MSP were mainly attributed to an increase in circulating blood volume. In the performance of the TAH, MSP (or MPP), proper diastolic duration and vacuum application during diastole was of prime importance in determining the end-diastolic ventricular volume.

Inactivation of the biological activities of the thermostable direct hemolysin of Vibrio parahaemolyticus by ganglioside Gt1

Biological activities of the thermostable direct hemolysin produced by Vibrio parahaemolyticus, such as its hemolytic activity and lethal activity, were inhibited by neuraminidase-sensitive gangliosides, of which GT1 ganglioside was the most inhibitory. Neuraminidase-resistant gangliosides did not affect the activities of the hemolysin. Results showed that horse erythrocytes, which are resistant to the hemolysin, do not contain the neuraminidase-sensitive gangliosides GT1 and GD1a. Therefore, we propose that neuraminidase-sensitive gangliosides, and especially GT1 ganglioside, may be the receptor sites on the membranes for the thermostable direct hemolysin of V. parahaemolyticus.

Increase in membrane conductance and positive inotropic action of hemolysin produced by Vibrio parahaemolyticus on rabbit myocardium

The effects of purified thermostable direct hemolysin from the cultured filtrate of Vibrio parahaemolyticus on both S-A node cells and atrial cells were studied electrophysiologically. Hemolysin caused the membrane conductance to increase, thereby causing membrane depolarization. The major ion responsible for this depolarization was Na+, but other ions, such as K+ and Ca2+, also participated. Positive inotropic action of hemolysin was observed, and the Na-Ca exchange mechanism was enhanced after hemolysin treatment.

Stopping of spontaneous beating of cultured mouse and rat myocardial cells by a toxin (thermostable direct hemolysin) from Vibrio parahaemolyticus

Low concentrations of thermostable direct hemolysin from Vibrio parahaemolyticus stopped the spontaneous beating of cultured mouse and rat myocardial cells. These low concentrations depolarized the maximal diastolic potential and inhibited the generation of action potential of cultured myocardial cells. The toxin lost its activity when preincubated with ganglioside, GT1 or GM1. GT1 was more effective than GM1. High concentrations of the toxin caused morphological damage of cultured mouse and rat myocardial cells, but did not stop the beating, or cause morphological damage of cultured chick myocardial cells.

Cytotoxic effect of the thermostable direct hemolysin produced by Vibrio parahaemolyticus on FL cells

The thermostable direct hemolysin produced by Vibrio parahaemolyticus showed cytotoxic activity on FL cells derived from human amniotic membrane. Scanning electron micrographs of the whole cells showed that the microvilli on the cell surface decreased in number and changed in shape on treatment with the hemolysin. Most of the microvilli disappeared before death of the cells, as judged from the results of staining the cells with trypan blue and measuring release of alkaline phosphatase from the cells. Electron micrographs of thin sections ofthe cells showed that the cytoplasm of the cells was not significantly affected by treatment with sublethal amounts of hemolysin, even when the microvilli on the cell surface were significantly affected. Lethal amounts of hemolysin affected the cytoplasm and caused disarovilli on the cell surface are affected by treatment with the hemolysin before cytoxic effects develop.

Identification of lethal toxin with the thermostable direct hemolysin produced by Vibrio parahaemolyticus, and some physicochemical properties of the purified toxin

Lethal toxin was purified extensively from the culture filtrate of a Kanagawa phenomenon-positive strain of Vibrio parahaemolyticus. The purified toxin was a protein, and its homogeneity was demonstrated by sodium dodecyl sulfate-polyacrylamide gel disc electrophoresis and analytical ultracentrifugation. It was demonstrated that the thermostable direct hemolysin was identical to the lethal toxin and that it was the main, if not only, lethal toxin in the culture filtrate. The purified toxin had a lethal effect when injected into mice either intravenously or intraperitoneally. Its lethal effect was very rapid, a dose of 5 mug of toxin per mouse killing the animals within 1 min. The lethal activity was inhibited by a ganglioside mixture. Some physicochemical properties of the purified toxin are reported.

Demonstration of the cardiotoxicity of the thermostable direct hemolysin (lethal toxin) produced by Vibrio parahaemolyticus

Intravenous injection of the thermostable direct hemolysin (lethal toxin) produced by Vibrio parahaemolyticus caused rapid death of rats. Studies by electroencephalography and electrocardiography showed that after intravenous injection of the toxin the electroencephalogram remained normal for quite a long time after the heart of the animals had stopped beating. Depression of intraatrial and intraventricular conduction of electrical activation, including atrioventricular block, was observed in electrocardiograms of animals injected with the toxin. The toxin was also found to be toxic to cultured mouse heart cells. When it was added to the medium, the beating rhythm of the cultured heart cells increased temporarily and then soon stopped abruptly. The effect of the toxin on cultured mouse heart cells was blocked by preincubation of the toxin with a ganglioside mixture. From these results it is concluded that the thermostable direct hemolysin (lethal toxin) had cardiotoxic activity, and thus administration of the toxin causes rapid death of animals.

Inhibition of hemolytic activity of the thermostable direct hemolysin of Vibrio parahaemolyticus by ganglioside

The hemolytic activity of the thermostable direct hemolysin produced by Vibrio parahaemolyticus was inhibited by a ganglioside mixture. The ganglioside component which inhibited the hemolysin was not FM1 ganglioside.

Refinement in application of total artificial heart, with improvement in survival and histopathological findings

Recent improvements in total artificial heart (TAH) experiments have changed the pathological findings as well as the concept of the TAH. In the past 3 years, 67 experiments were performed in our laboratory. This study concerns the 11 calves operated upon most recently. Histopathological findings in the lungs, kidneys, livers and spleens of these animals were greatly improved over findings from previously studied animals. Disseminated intravascular coagulation (DIC) syndrome has been seen in only 1 calf. These improvements can be attributed to the following factors: (1) Improved management of the lumg during surgery has essentially eliminated pulmonary insufficiency;(2) liver damage has been successfully prevented by the discovery of the relationship between high right atrial pressure and anemia; (3) careful aseptic surgical procedures and optimal prophylactic use of antibiotics and anticoagulants have minimized the incidence of infection and clot formation.

The effect of dipyridamole on the coronary hemodynamics in man

The effects of dipyridamole (Persantin) on the coronary blood flow (the great cardiac vein flow and coronary sinus ostial flow), the femoral arterial pressure, the coronary vascular resistance and the heart rate were measured continuously in man. The newly devised method of the continuous local thermodilution method enabled us to perform the exact measurement of the above mentioned variables in man. The increase of the coronary blood flow was seen definitely in the non-ischemic group and, therefore, the decrease in the coronary vascular resistance occurred in 30 sec and continued for more than 20 min. In the myocardial ischemic group, some patients showed the similar response to the non-ischemic group. However, some patients showed no increase of the flow, even though the coronary vascular resistance decreased in all cases in this group. The heart rate increased slightly in all cases.

Possible identity between the hepatoma alkaline phosphatase and an isozyme of human amniotic membrane (FL cells)

The electrophoretically faster migrating alkaline phosphatase isozyme in FL cells derived from the human amniotic membrane was similar in some of the enzymatic and immunochemical properties to the variant alkaline phosphatase which occurs in serum and cancerous tissue of some patients with hepatocellular carcinoma. These facts suggest that the hepatoma-associated alkaline phosphatase may be the resurgence of the isozyme originally present in the amniotic membrane.

Syntheses and tissue distribution of 99m-Tc-sulfonylureas

Four new tolbutamide analogs were prepared and evaluated as hypoglycemics. Hypoglycemic action was observed in two members of the class, and 99m-Tc-chelates were tested as potential radiopharmaceutical imaging agents.

One 25 day survivor with total artificial heart

One calf, which weighed 87 kilograms, survived for 25 days with a total artificial heart (TAH) implanted orthotopically. All hemodynamic parameters stayed normal except the right atrial pressure (RAP), which increased gradually toward the end of the experiment. The cardiac output was maintained between 8.0 and 11.0 L. per minute. Kidney function was well maintained, and no pulmonary insufficiency was noted. Infection became obvious after 2 weeks of pumping although it was controlled to the extent that the calf was able to eat, to several factors, amont them mechanical damage to red blood cells, infection, malnutrition, and liver damage. The calf was standing until 30 minutes before its sudden death from cerebral thromboembolism. The calf's activity throughout the postoperative course convinced us of the feasibility of clinical application and of immediate application to studies of cardiovascular physiology and pharmacology.

Antigenic difference between polar montrichous and peritrichous flagella of Vibrio parahaemolyticus

Polar monotrichous and peritrichous flagella of Vibrio parahaemolyticus were isolated and purified separately. On hydroxylapatite column chromatography, the flagellins of polar monotrichous flagella were eluted with a higher concentration of phosphate than those of peritrichous flagella. Gel diffusion tests showed an antigenic difference between the flagellins of polar monotrichous and peritrichous flagella. Electron microscope observations on cells stained with ferritin-conjugated antibodies demonstrated that polar monotrichous and peritrichous flagella reacted specifically with antimonotrichous flagellin and antiperitrichous flagellin antisera, respectively.