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Biomedical subjects

R Yamaguchi

Publications and source records attributed to R Yamaguchi.

At least 217 records · Page 12Linked to original sources
PubMed1978

Effect of cyclic AMP on placental active transport of amino acid in rats.

In pursuit of the probable relationship of cAMP to the placental active transport of amino acids as suggested by our previous human data, experiments were done in this study with dibutyryl cAMP and theophylline loaded in pregnant rats to examine the changes in level of 14C-lysine in the maternal liver, placenta and fetus. The results are: (1) Loading of dibutyryl cAMP had no effect on the uptake of 14C-lysine in the maternal liver, placenta or fetus, except that the correction of the values with its concentration in the maternal blood revealed only a slightly significant elevation in the value in each of them 30 min after the loading. (2) Loading of theophylline significantly increased the uptake of 14C-lysine in all these organs. (3) The content of cAMP in the placenta significantly increased with the loading of theophylline. These results have led the authors to believe that endogenous cAMP is significantly linked with the placental active transport of amino acids, though there is no apparent contribution to it by exogenous cAMP.

Amino Acids↗
PubMed1978

Diagnosis of placental function by prediction curves for heat-stable alkaline phosphatase (HSAP).

In order to establish an effective diagnostic method for placental function using HSAP, the authors formulated two expressions to predict HSAP values for their rise before 38.7 weeks of gestation and declining after that; loge y = 1.03a-3.37 + 0.123x (i), and y = Y (1 + d/100( (ii), respectively. Further they prepared a chart of curves for these predicting expressions. The results obtained are as follows: (1) In normal pregnancies the deviation of prediction from measured values of HSAP was +/- 15% in 94% of the cases examined. (2) Many of cases of abnormal pregnancy showed a low level of HSAP, -15% or lower, and abnormal signs in HSAP pattern were found several days or weeks prior to the onset of fetal troubles. (3) Prolonged pregnancy with fetal troubles was able to be distinguished from "false" prolonged pregnancy. (4) In two consecutive pregnancies in the same woman, the courses of HSAP were strikingly consistent as far as both pregnancies were normal. The last fact suggests that the placental production of HSAP and its release into the maternal blood may be influenced by the individual constant a in expression (i). (5) It is recommended that the HSAP prediction curve is worthy to use as an easy screening method for placental function in the third trimester of pregnancy.

Alkaline Phosphatase↗
PubMed1977

Feto-maternal amino acid patterns and cyclic AMP in the human placenta with abnormal pregnancies, particularly with SFD.

To clarify the causes of SFD from the view-point of placental function, investigations were made on feto-maternal amino acid circumstances and on how cyclic AMP behaves in the placenta, particularly in relation to the transport of amino acid across the placenta. Amino acids were measured by gas liquid chromatography (hydrogen-flame ion detector), c-AMP by the binding protein method, adenyl cyclase activity by Krishna's method, and proteins by Lowry's method. Results show: (1) The levels of maternal amino acids were indistinctive between the SFD group and the normal pregnancy group. (2) The feto-maternal ratio of amino acid concentrations (f/m ratio) was lower in the SFD group than in the normal control. (3) The level of c-AMP in the placenta was lower in the SFD group than in the control. (4) The lower level of placenta c-AMP in the SFD placenta seems partly attributable to the decreased adenyl cyclase activity. (5) There was a positive correlation (gamma=0.61) between the content of c-AMP in the placenta and the f/m ratio of amino acid concentrations. These findings suggest a decline in placental active transport of acids in SFD; adenyl cyclase and c-AMP in the placenta presumably play a key role in such course.

Adenylyl Cyclases↗
PubMed1976

Preventive procedure of dysuria after radical hysterectomy by adnexal flap fixation to the bladder.

To prevent postoperative dysuria, which occurs inevitably after the radical hysterectomy, several surgical procedures have been tried. The principal method is to suture adnexal flaps to the bladder trigone and fundus. Of four procedures so far tried sequentially, the best one was to fix the bladder trigone and to support it with round ligament flaps sutured with the bladder fundus covered by tubal flaps (Type IV). In follow-up studies, Type IV proved more preferable than the other three types or the non-sutured control group in regard to the following aspects: (1) days necessary for the disappearance of residual urine, (2) appearance of urinary sensation, (3) acquirement of urinary sensation, (4) incidence of urinary incontinence, (5) residual urine/bladder capacity ratio, (6) cystometric findings, and others. Effectiveness of our procedures, particularly of Type IV, may be ascribed to the supported bladder trigone and fundus by sutured tissues and to the acquirement of urinary sensation, rather than to the restoration of nervous contact between the bladder and the micturition center in the spinal cord.

Adnexa Uteri↗