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Biomedical subjects

N Takano

Publications and source records attributed to N Takano.

At least 73 records · Page 4Linked to original sources
PubMed1984

Changes of ventilation and ventilatory response to hypoxia during the menstrual cycle.

The relationship between change in hypoxic sensitivity in respiration, defined as increment in ventilation per drop of arterial O2 saturation (delta VE/delta SaO2), with the phase change from follicular to luteal and those in resting pulmonary ventilation (VE), mean inspiratory flow (VT/TI), alveolar partial pressures of CO2 and O2 (PACO2 and PAO2, respectively) and body temperature was studied in 10 women. There was a significant relationship between % increase in hypoxic sensitivity and decrement of resting PACO2 that occurred in the luteal phase. However, no significant relationships were observed between change in hypoxic sensitivity and those in the remaining parameters studied. The intersubject variation in % increase in resting VE during the luteal phase was not associated with that in % increase in hypoxic sensitivity. The results indicate that the contribution of increased hypoxic sensitivity to increasing VE during the luteal phase is variable among subjects. Reasons for the increase in hypoxic sensitivity with hypocapnia are discussed.

Adult↗
PubMed1984

Reflex hypoxic drive to respiration during the menstrual cycle.

We studied a maximum fall in VE (max delta VE) produced by 20 sec O2 breathing and its percentage of resting VE (reflex hypoxic drive) on 9 menstruating women, in order to examine menstrual phase effect on reflex hypoxic drive. During the luteal phase, resting PAO2 was higher by 4.8 mm Hg and PACO2 was lower by 3.0 mm Hg than during the follicular phase. In spite of these changes in the alveolar gases, reflex hypoxic drive was greater in the luteal phase (14.4%) than in the follicular phase (9.3%). Resting VE in the luteal phase was 7.8% greater than that in the follicular phase. Contribution of the augmented hypoxic drive to the increased resting VE in the luteal phase, calculated as delta (max delta VE)/delta VE (%), was 59 +/- 29% (mean +/- SE). These results suggest that progesterone-induced hyperventilation, as occurs in the luteal phase, is elicited partly by mediating an increase in reflex hypoxic drive which is probably produced centrally even in hyperoxia and hypocapnia, but the role of augmented hypoxic drive is highly variable among subjects.

Adult↗
PubMed1984

[Studies on tissue concentrations of cefoperazone and piperacillin classified by the site of the wall of gallbladder and concentration of piperacillin in the bile after operation].

In selection of drugs to be used in the treatment of biliary tract infections, sensitivity of causative organisms to drugs and tissue concentrations of the drugs constitute important factors. In the present study we treated patients with cholelithiasis with cefoperazone (CPZ) and piperacillin (PIPC), both of which have been reported to show high concentrations in the bile, and concentrations of the drugs in serum, cholecystic bile and various sites of the wall of gallbladder were determined. In addition the drug concentrations in the serum and bile at the 1st and 7th postoperative days were also determined. The following results were obtained. Comparison of concentrations of CPZ and PIPC at various sites of the wall of gallbladder revealed that both drugs showed high levels in the bottom, body and neck areas of the gallbladder with no difference by sites. The concentration ratios against serum for these drugs were 71.8 and 83.6%, showing good transference into tissue. The mean concentrations of CPZ and PIPC in the cholecystic bile were as high as 448.8 and 381.6 micrograms/ml, the ratio against serum being about 4:1. The serum concentrations of PIPC at the 1st and 7th postoperative days were 116 and 137 micrograms/ml at 60 minutes after starting drip infusion, with no difference between these 2 days. In the bile concentrations of PIPC on both postoperative days showed the peak levels of 2,587 and 1,157 micrograms/ml at 120 minutes after starting drip infusion. The concentrations at the 1st postoperative day were higher. The recovery rate of PIPC from the bile was also higher at the 1st postoperative day. From the results that both drugs showed high levels in the wall of gallbladder and also showed high levels in the bile immediately after the operation, PIPC and CPZ are considered to be effective drugs for biliary tract infections.

Bile↗
PubMed1983

Correlation between the antitumor activity of a polysaccharide schizophyllan and its triple-helical conformation in dilute aqueous solution.

Eight samples of a polysaccharide schizophyllan ranging in weight-average molecular weight Mw (in water) from 5 x 10(3) to 1.3 x 10(5) were prepared and their antitumor activity (expressed in terms of the tumor inhibition ratio) against Sarcoma 180 ascites, intrinsic viscosities [eta], and gel-filtration chromatograms in aqueous solution were determined. The tumor inhibition ratio was essentially unity for samples with Mw higher than 9 x 10(4), but reduced to zero or even to a negative value when Mw was lower than 10(4). The [eta] data combined with the chromatographic data showed that above Mw approximately 9 x 10(4) the predominant species of schizophyllan in aqueous solution is the previously found rigid triple helix, whereas below Mw approximately 9 x 10(4) both triple helices and single chains coexist in the solution and the fraction of triple helices decreases monotonically to zero as Mw is decreased to 5 x 10(3). From these findings it was concluded that the antitumor potency of schizophyllan in water is related to the amount of triple helices relative to that of single chains.

Journal Article↗
PubMed1983

Renal contribution to acid-base regulation during the menstrual cycle.

Menstruating women exhibit a light but sustained hypocapnia during the luteal phase. To elucidate whether the hypocapnia results primarily from a respiratory or renal mechanism, we measured the rate of urinary excretion of acid at intervals during the menstrual cycle in five subjects. The acid-base composition of arterial blood in three subjects and end-tidal PCO2 in the remaining two subjects were also determined. During the follicular phase, the acid-base composition of blood and the rate of net acid excretion remained virtually constant. After ovulation, significant decreases in PaCO2 (3.5 mmHg), [HCO3]p (2 meq/liter), and net acid excretion (2 meq/h) occurred in the first 4-6 days of the luteal phase (14 days long). Following this, net acid excretion returned to the preovulatory level. PaCO2 and [HCO3]p, however, remained decreased for 3 more days. At the end of the luteal phase, restoration of PaCO2 proceeded faster than that of [HCO3]p. The acid-base changes in blood and urine observed during the luteal phase were comparable to those occurring during adaptation and recovery from sustained hypocapnia, suggesting that hypocapnia during the luteal phase is primarily respiratory in origin.

Acid-Base Equilibrium↗
PubMed1982

Resting pulmonary ventilation and dead space ventilation during the menstrual cycle.

By reanalyzing our previous study (TAKANO et al., 1981) of resting ventilation and PACO2 during the menstrual cycle of eight healthy women, we found that relative to the follicular phase, a 9.4% increase in VA (p less than 0.05) and a 2.5 mmHg decrease in PACO2 (p less than 0.001) occurring during the luteal phase, both of which have been reported previously, were attributable mostly to a decrease in VD (-7.2%, 0.05 less than p less than 0.1) but not to an increase in VE (+1.9%, N.S.), the latter two changes producing an 8.7% decrease in VD/VT (p less than 0.01).

Adult↗
PubMed1982

Defective estrogen receptor in uteri of rats treated neonatally with a high dose of estrogen.

The female Sprague-Dawley rats were daily injected with 100 micrograms of estradiol-17beta from the day of birth to 10 days of age. All these neonatally estrogenized rats exhibited a state of persistent vaginal diestrus after attainment of puberty. When 3H-estradiol-17beta was administered, the radioactivity in the uteri of the estrogenized postpubertal rats was significantly reduced, compared to that in the untreated rats. Otherwise, there was no significant difference of the radioactivity in the liver, diaphragm, and serum between the estrogenized and untreated groups. Uterine estrogen receptor having a sedimentation constant of 8S was demonstrated in the untreated immature and mature rats by sucrose density gradient centrifugation, whereas there was no detectable estrogen binding components in the uterine cytosol from the estrogenized postpubertal rats, irrespective of the date of autopsy. No discernible changes in the sedimentation profiles could be observed in the estrogenized postpubertal rats after oophorectomy. The results suggest that high doses of estrogen administered in the estrogen administered neonatally to female rats may couse permanent deficiency of uterine estrogen receptor and result in uterine insensitiveness to estrogen in their later lives.

Animals↗
PubMed1981

Analysis of alveolar PCO2 control during the menstrual cycle.

We attempted to analyze how PACO2 is regulated during progesterone-induced hyperventilation in the luteal phase. A model for the CO2 control loop was constructed, in which the function of the CO2 exchange system was described as PACO2 = 0.863 x VCO2/VA (gain H = dPACO2/dVA) and that of the CO2 sensing system as VA = S (PACO2 - B). Using this model, we estimated (1) the primary increase in VA (delta VA (op)) produced by progesterone stimulation and (2) the effectiveness (E) of the loop to regulate PACO2, defined as delta PACO2 (op)/delta PACO2 (cl) in which op signifies open-loop and cl, closed-loop. These respiratory variables were investigated throughout the menstrual cycle in 8 healthy women. During the luteal phase, on average, VA increased by 9.4% and PACO2, B and H decreased by 0.33 kPa (2.5 mm Hg), 0.47 kPa (3.5 mm Hg) and 13.6%, respectively, while S and VCO2 did not change significantly. Delta VA (op) increased progressively on successive days of the luteal phase while E remained unchanged at a value of 7.9, thus there was a progressive decrease in PACO2. The decrease in H was considered to lessen delta PACO2 (op) and so reduce the final deviation of PACO2 (delta PACO2 (cl) during the luteal phase. The decrease in B was found to be dependent on delta VA (op).

Adult↗
PubMed1981

[Clinical evaluation of pivmecillinam in the maintenance therapy of chronic urinary tract infection (author's transl)].

In order to evaluate the efficacy and safety of pivmecillinam (melysin tablet, PMPC), PMPC was administered to 78 chronic UTI cases in the field of obstetrics and gynecology (posthysterectomy infection, chronic cystitis, chronic pyelonephritis and etc.). In principle, daily 400 mg of PMPC was administered for 2 weeks. (1) Overall clinical efficacy judged by doctor was evaluated in 78 cases and the result was; excellent in 17, good in 37, fair in 10, poor in 13 and unknown in 1 case with the effectiveness rate of 69.2%. (2) Overall clinical efficacy judged by 'criteria for clinical evaluation in complicated UTI' recommended by UTI study member was evaluated in 54 cases and the result was; excellent in 15, good in 20 and poor in 19 cases with the overall efficacy rate of 64.8%, the result of which was similar to that of doctor's judgement. (3) Efficacy on pyuria was evaluated in 72 cases and it was cleared in 27, decreased in 25, unchanged in 20 and unknown in 6 cases. Efficacy on bacteriuria was evaluated in 72 cases and it was eliminated in 44, decreased in 9, replaced in 8, unchanged in 8 and unknown in 9 cases. (4) Side effect, considered by doctors to be caused by PMPC administration, was noticed in 3 out of 78 cases (3.8%), all of which was mild gastrointestinal disturbance and the administration of PMPC was continued. Abnormal change of laboratory finding considered by doctors to be caused by PMPC administration was noticed in 1 out of 78 cases, which was slight elevation of GOT and GPT values. It is therefore considered that PMPC appear to be useful drug for the maintenance therapy of chronic UTI in the field of obstetrics and gynecology.

Adult↗
PubMed1980

[Analytical studies of HSG on cases of tuboplasty and their histopathological findings (author's transl)].

Tubal shadows in HSG after the tuboplasty were analysed in relation to their histology, for the betterment of diagnosis of tubal factors and for the establishment of appropriate therapeutic indication in infertile clinics. 91 cases of tuboplasty were followed up more than one year postoperatively. One set of HSG consist of four films; immediately after injection of contrast medium 3-5 ml (1), additional 6-10 ml (2), their side snap (3) and 5 minutes after the end of injection (4). Tubal partial resection was performed in some of them for microscopic and SEM studies correlating with HSG figures. Passage recovery was observed more than one year, in 73 tubes (52.1%) out of 140, in 91 cases. Pregnancy was successfully brought about in 16 (17.6%). HSG with abnormal direction and shape in tubal shadows suggested adhesion, endometriosis or tumor in their corresponding portions. Abnormal morphology of tubal shadow was associated with histopathological changes in high occurrence rate. Posttuboplatic pregnant cases have indicated physiological range both in their postoperative HSG and in their histological changes.

Fallopian Tubes↗
PubMed1979

Acid-base curve nomogram for chimpanzee blood and comparison with human blood characteristics.

An acid-base nomogram for chimpanzee blood was constructed. Blood was drawn from eight lightly anesthetized chimpanzees. Each sample of blood was oxygenated and nine aliquots were prepared with three different concentrations of hemoglobin and three different amounts of added acid or base. Each aliquot was equilibrated at two PCO2 levels and the pH was measured and plotted on pH-logPCO2 coordinates. Using the intersection point of these pH-logPCO2 lines as a point of equal hemoglobin-independent "base excess" for each condition, values for true base excess were plotted. Connecting these values provided a Cartesian PCO2-pH base excess nomogram for the chimpanzee comparable to that devised by Siggaard-Andersen for humans. Examination of blood from normal human subjects by the same methods showed no appreciable differences from the original Siggaard-Andersen nomogram. However, the PCO2-pH-base excess nomogram for chimpanzee blood deviated slightly from that for human blood. It is possible that the deviation is related to an arterial bicarbonate concentration in the chimpanzee slightly higher than that in human.

Acid-Base Equilibrium↗
PubMed1979

Body temperature and oxygen consumption of newborn rats at various ambient temperatures.

The thermogenic response and rectal temperature (Tre) of newborn rats (0 to 32 days old) on exposure to various ambient temperatures (Ta) were investigated. The O2 consumption (VO2 in ml . min-1 per 100 cm2 surface area) was measured for one rat at a time by means of a closed circuit system. The results were that (1) within the thermal neutral ranges, Tre stood at 36--37 degrees C regardless of the age and the value of VO2 was lowest at the age of 6--7 days, after this period increasing and reaching a level of 1.4 ml . min-1 . cm-2 X 10(-2) after 18--21 days old (the weaning period); (2) the thermogenic response to cold (delta VO2/--delta Ta) was higher at ages prior to the weaning period than after the weaning period; (3) in spite of the higher thermogenic responses, Tre decreased markedly on exposure to cold prior to the weaning period, because of a poor development of thermal insulation; and (4) the achievement of homeothermy of the rat at subneutral temperatures was observed after the weaning period.

Animals↗