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Biomedical subjects

K Shimamoto

Publications and source records attributed to K Shimamoto.

At least 343 records · Page 19Linked to original sources
PubMed1987

Plasma levels of human atrial natriuretic peptide in patients with hypertensive diseases.

Three types of antihuman atrial natriuretic peptide antiserum were obtained. From the study of cross-reactivity to human atrial natriuretic peptide fragments, it was suggested that antisera-1, -2, and -3 are mostly specific to 1-28, 5-25, and the ring structure, respectively. The estimated values of this hormone were significantly lower in the order of antisera-1, -2, and -3. Moreover, high performance liquid chromatographic study showed that various types of fragments of atrial natriuretic peptide exist in human plasma. These findings suggested that the highly specific antiserum to 1-28 human atrial natriuretic peptide such as antiserum-1 should be used to estimate the 1-28 human atrial natriuretic peptide levels in human plasma. From the study by using antiserum-1, it was concluded that the plasma human atrial natriuretic peptide increased in essential hypertensives, and in patients with primary aldosteronism, chronic renal failure, and malignant hypertension. Regarding the pathophysiological significance of increased plasma atrial natriuretic peptide, it is unlikely that this plays an important role in the etiology of essential hypertension or other hypertensive diseases, because the plasma level of this hormone is elevated in these patients. The increase of plasma atrial natriuretic peptide level in these patients should be considered to be a secondary or compensatory reaction to high blood pressure.

Aldosterone↗
PubMed1987

Intratumoral blood flow: evaluation with color Doppler echography.

Blood flow in several types of tumors (two hepatomas, two hemangiomas, two renal cell carcinomas, one hydatidiform mole, and five invasive moles) was assessed with real-time two-dimensional color Doppler echography (ultrasound). In one of the hepatomas and all five of the invasive moles (but not in the hydatidiform mole or in either of the hemangiomas), the intratumoral flow was demonstrated with color Doppler echography, correlating well with the angiographic or dynamic computed tomographic findings. In the invasive moles, rapid blood flow was seen within the hypoechoic zone of the tumor. On follow-up study of four of the invasive moles, disappearance of the hypoechoic area due to blood flow was observed when chemotherapy was successful. Trophoblastic disease is considered to be the best application for color Doppler echography because it provides accurate evaluation of residual tumor after chemotherapy.

Carcinoma, Hepatocellular↗
PubMed1987

The analytical value for kinin concentration in blood depends on the antiserum used in the bradykinin radioimmunoassay.

Recently published blood kinin concentrations are subject a wide scatter, due to sampling time and technique. In our study we tested the influence of the used antibradykinin antiserum on the measured kinin concentration in blood. Blood was collected from the anticubital vein by a teflon cannula and inactivated immediately by hydrochloric acid in the syringe. Subsequent extraction was performed using diethylether, n-butanol, distilled water and Biorex-70. The blood extract containing the kinins was divided into four samples and measured by four radioimmunoassays using different antibradykinin antibodies. All four assays were performed under standard conditions and at the same time. The resulting kinin values were similar in two assays: 7.4 +/- 2.6 ng/l and 5.6 +/- 1.3 ng/l. In the two other assays, however, the measured kinin concentrations differed markedly from these values: 127.5 +/- 46.7 ng/l and 693.0 +/- 85.7 ng/l. These results indicate clearly that the antibody used in the assay can be a major factor determining the range of the recorded kinin concentration.

Bradykinin↗
PubMed1987

The radioimmunoassay for human plasma atrial natriuretic peptide--its application to uremic patients.

A highly sensitive radioimmunoassay for alpha-human atrial natriuretic peptide (alpha-hANP) was established and applied to measure the human plasma alpha-hANP levels. In our assay system, anti-alpha-hANP antiserum was raised in albino rabbits by intradermally injecting synthetic alpha-hANP which was conjugated with bovine serum albumin. The final antiserum dilution was 1:50,000. Sensitivity was 2 pg/tube and the 50% intercept was at 28 pg/tube. The plasma alpha-hANP was extracted using a Sep-Pak C-18 cartridge. According to this procedure, the mean recovery was 73.8 +/- 3.4% (mean +/- SE). The averaged plasma levels of immunoreactive alpha-hANP (i alpha-hANP) in normal subjects were 24.8 +/- 2.1 pg/tube. In patients with chronic renal failure undergoing hemodialysis, the averaged plasma i alpha-hANP levels were 56.4 +/- 5.0 pg/ml before hemodialysis. Plasma i alpha-hANP levels were significantly higher in the patients with chronic renal failure than in the normal subjects. After hemodialysis, plasma i alpha-hANP levels decreased significantly (32.2 +/- 2.8 pg/ml). These results suggest that the alteration in extracellular fluid volume (ECFV) may affect the plasma levels of i alpha-hANP in patients with chronic renal failure under hemodialysis; i.e., an increase in ECFV elevates and a decrease in ECFV lowers the circulating levels of alpha-hANP.

Animals↗
PubMed1987

Kallikrein in the male reproductive system.

Male genital organs were stained by the peroxidase-antiperoxidase (PAP) method to know the location of kallikrein. Sertoli cells of the testis, epithelial cells that existed from the body to the tail of the epididymis, and glandular cells of the prostate were specifically stained showing that kallikrein was produced in these cells. The concentration of kallikrein in the semen specimens mainly from patients with male sterility and from those who were subjected to vasoligation and in the prostatic fluid specimens from normal controls were measured by radioimmunoassay (RIA). The results of column chromatography suggested that kallikrein combined with the other substances to form a high molecular compound in the semen. The kallikrein level in the semen from the normal control was 40.4 +/- 21.3 ng/ml, which was more than 10 times that in the blood. The value tended to increase with the decrease of the number of spermatozoa. The kallikrein level in the semen from patients with azoospermia was 74.2 +/- 23.5 ng/ml, which was significantly higher than that of the normal control. There was no significant correlation between the kallikrein level and the sperm motility. The kallikrein level in the semen from the patients subjected to vasoligation, which did not contain the semen originated from the testis, and that in the prostatic fluid from the normal control were 20-28 ng/ml. That amount was considered to be secreted from the prostate. The oral administration of hog kallikrein tablet augmented seminal human kallikrein and Acid-P secretion. Moreover, an improvement of seminalysis was observed following long term administration of 600 U/day of hog kallikrein in the male infertile patients. This drug might be useful to treat the male infertile patients with this disorder.

Adult↗
PubMed1987

Role of renin-angiotensin and kallikrein-kinin systems on the mechanism of the hypotensive effects of converting enzyme inhibitor, alacepril.

In four patients with essential hypertension and one patient with renovascular hypertension, decreases in blood pressure and plasma angiotensin II levels, and increases in plasma renin activity and plasma kinin levels were observed during eight days of alacepril treatment. Significant correlations between the changes in mean arterial pressure and those in plasma angiotensin II or kinin levels were observed positively or negatively, respectively, in the essential hypertensives. These findings suggest that the hypotensive effect of alacepril might be caused mainly by a decrease in plasma angiotensin II levels and, at least in part, by an increase in plasma kinin levels.

Adult↗
PubMed1987

A sensitive method for precise measurement of endogenous angiotensins I, II&III in human plasma.

We measured endogenous angiotensins (ANGs) I, II&III using a system of extraction by Sep-Pak column followed by high performance liquid chromatography (HPLC) combined with radioimmunoassay (RIA). An excellent separation of ANGs was obtained by HPLC. The recovery of ANGs I, II&III was 80-84%, when these authentic peptides were added to 6 ml of plasma. The coefficient of variation of the ANGs was 0.04-0.09 for intra-assay and 0.08-0.13 for inter-assay, thereby indicating a good reproducibility. Plasma ANGs I, II&III measured by this method in 5 normal volunteers were 51,4.5 and 1.2 pg/ml. In the presence of captopril, ANGs II&III decreased by 84% and 77%, respectively, while ANG I increased 5.1 times. This method is therefore useful to assess the precise levels of plasma ANGs.

Angiotensin I↗
PubMed1987

Interrelation between plasma kinin and the sympathetic nervous system in normal subjects.

To investigate the relationship between plasma kinin and the sympathetic nervous system, we measured plasma kinin, norepinephrine, and angiotensin-I-converting enzyme (ACE:kininase II) activity in normal subjects. In six normal subjects, subpressor and pressor doses of norepinephrine (10 ng/kg/min and 50 ng/kg/min, respectively) were infused for 1 hour. In five normal subjects, 60-degree head-up tilting was performed for 20 minutes. After norepinephrine infusion, plasma kinin levels were decreased significantly (p less than 0.01) with the subpressor dose of norepinephrine and were further decreased (p less than 0.01) with the pressor dose. Plasma ACE activity, however, showed no significant changes following these infusions. During the tilting, plasma kinin levels decreased significantly (p less than 0.01), whereas plasma norepinephrine levels increased significantly (p less than 0.01). From these results, the assumption of elevated levels in plasma endogenous or exogenous norepinephrine leads to a decrease in plasma kinin levels; this suggests that these two systems may be closely interrelated.

Adult↗
PubMed1987

The role of plasma angiotensin I converting enzyme in regulation of renin-angiotensin system activity in patients with essential hypertension.

In order to investigate the role of plasma angiotensin I (pAI) converting enzyme on the activity of the renin-angiotensin system, we measured plasma renin activity (PRA), plasma angiotensin II (pAII), and plasma angiotensin I converting enzyme (pACE) activity in fourteen patients with essential hypertension before and after two hours of ambulation combined with intravenous furosemide administration. Significant increases were observed in the values of PRA (p less than 0.005), pAII (p less than 0.005) and ACE activity (p less than 0.05) after ambulation. The ratios of log pAII/log PRA were increased significantly after ambulation (p less than 0.005), and a significantly positive correlation was observed between log pAII/log PRA and ACE activity (p less than 0.01). These results suggested that not only PRA but also ACE activity contributed to the activity of renin-angiotensin system through the generation of AII.

Adult↗
PubMed1987

CT evaluation of pancreatic cancer. Analysis of resected tumours.

Preoperative CT examination including dynamic scan was performed in 25 patients with pancreatic carcinoma. Dynamic scans, which clearly demonstrated the attenuation difference between the normal and neoplastic pancreatic tissue in 92% of cases, were superior to high dose contrast enhancement scans that failed to display the relatively hypodense component of tumours in 40%. Detailed comparison of CT interpretation and surgical or pathological findings revealed the usefulness of CT examination in the evaluation of tumour size and local invasion. However, low sensitivity in detection of metastatic lesions (range: 20-38%) indicates limitations of CT diagnosis.

Adenoma, Islet Cell↗
PubMed1987

[Evaluation of ultrasonography in management of choriocarcinoma and invasive mole].

To clarify the clinical significance of ultrasonography (USG) in the therapeutic course of invasive mole and choriocarcinoma, a detailed study of USG images from 31 patients, taken upon admission, in which an abnormal condition was clearly indicated, was undertaken. In addition, the clinical value of the pulse doppler and color doppler images used to determine the blood flow was also studied. The results revealed the following points. 1) Before the 1st therapy, USG conditions could be classified into three categories, type I (massive echogenic), type II (one or more echo free space (EFS) surrounded with a massive echogenic area) and type III (EFS). 2) A large number of patients with invasive mole exhibited type II, with a few exhibiting type III. A large number of patients with choriocarcinoma exhibited type I, and a few exhibited type II. 3) A comparison with PAG conditions showed a high correlation between the pooling image in PAG and the EFS in USG. 4) There was a positive correlation between the estimated volume of the tumor at the start of therapy and the hCG value in urine. In the chemotherapy patients, the reduction of hCG was accompanied by shrinkage of the tumor, and in 9 out of 22 patients (40.9%), the tumor disappeared on the USG at the point where the hCG became negative. 5) 14 of 22 chemotherapy patients (63.6%) matched the "Standard Progress" course, which was decided and based on the changes observed in the USG image over the course of chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Choriocarcinoma↗
PubMed1987

[The systolic slipping mechanism of the anterior mitral leaflet in patients with the straight back syndrome].

The systolic slipping mechanism of the anterior mitral leaflet in patients with the straight back syndrome (SBS) was evaluated by two-dimensional echocardiography in 16 SBS patients and 11 normal subjects. Doppler echocardiography was performed in all subjects to detect mitral regurgitation. The site of the mitral slipping was identified in a centromedial region of the anterior mitral leaflet in these patients. The ellipsoidal index (long axis/short axis) of the left ventricle was greater in SBS patients than in normal subjects. The left ventricular wall had a characteristic motion in SBS. The lateral wall contracted well, while the posterior septum and inferoposterior wall were hypokinetic. Moreover, the anterolateral papillary muscle moved horizontally during systole, while the posteromedial papillary muscle moved anteriorly. There was a significant correlation between the distance of slipping of the anterior mitral leaflet and the PL/PM ratio (r = -0.39, p less than 0.001), where PL is the distance from the gravity point of the left ventricle to the midpoint of the anterolateral papillary muscle, and PM is that from the gravity point of the left ventricle to the posteromedial papillary muscle. Mild mitral regurgitation was identified in four cases with SBS by Doppler echocardiography, and this regurgitant jet was directed from the posterior mitral leaflet to the posterior wall of the left atrium. These results suggest that the systolic slipping of the anterior mitral leaflet in SBS might be caused by asynchronous papillary muscle motion. This might be based on the ellipsoidal left ventricle due to the short internal dimension of the thorax.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

The tissue kallikrein-kinin system in human seminal plasma--biochemical and functional aspects.

At least three species of tissue kallikrein-like antigens are present in human seminal plasma which differ in their molecular masses and enzymatic activities. At least one of these species is a genuine tissue kallikrein as judged by the criteria of molecular mass, immunoreactivity, inhibition by aprotinin and non-inhibition by soybean trypsin inhibitor, and the ability to release kallidin from kininogen. The prostatic gland was identified as the origin of the seminal fluid tissue kallikrein first by indirect studies and then by demonstrating the presence of immunoreactive tissue kallikrein both in prostatic tissue and secretion.

Humans↗
PubMed1986

Interrelation between the renin-angiotensin system and kallikrein-kinin system in patients with essential hypertension.

In order to investigate the relationship between the kallikrein-kinin (K-K) system and renin-angiotensin (R-A) system, plasma kinin (pKIN), plasma angiotensin II (pAII), plasma renin activity (PRA) and angiotensin converting enzyme activity (ACEA) were determined in 19 essential hypertensives (EHT). pKIN and pATII measurements were performed by highly sensitive radioimmunoassay (RIA), both of which were established in our laboratory. The assay sensitivity of pKIN and pAII were 0.5 pg/tube and 0.1 pg/tube, respectively. In pKIN RIA, pKIN was extracted by ethanol from 0.8 ml of plasma obtained with a syringe containing kinin generating and destroying enzyme inhibitors. In pAII RIA, pAII was measured directly in small amounts of 50-100 microliter, unextracted plasma samples. The level in pAII was significantly higher (p less than 0.05) in the normal renin group (NRH: n = 13) as compared with low renin group of EHT (LRH: n = 6). However, no significant difference was found in pKIN and ACEA between these two groups. Although a significantly positive correlation was observed between pAII and PRA (p less than 0.001) in EHT, the ratio of pAII/PRA tended to be higher in LHR than in NRH. ACEA correlated positively with pAII (p less than 0.01) or PRA (p less than 0.02), respectively. On the other hand, a significant negative correlation was also found between pKIN and pAII (p less than 0.05). From these findings, it was assumed that there was a closed relationship between R-A and K-K systems, and that angiotensin converting enzyme (kininase II) might play some role in the interrelation between both systems.

Adult↗
PubMed1986

The role of renal kallikrein-kinin system and prostaglandins in diuresis and natriuresis following saline infusion in normotensives and essential hypertensives.

In order to clarify the significance of the renal kallikrein(KAL)-kinin(KIN) system and prostaglandins (PG) in exaggerated natriuresis in essential hypertensives, the effect of acute sodium load on urinary KAL, KIN, PG, and renal water and sodium handling were investigated in normotensives (NT) and patients with essential hypertension (EHT). Nine NT and seven EHT were studied following acute physiological saline infusion (1000 ml/2 hrs). Urine volume (UV), urinary sodium excretion (UNaV), fractional excretion of sodium (FENa), and fractional excretion of inorganic phosphorus (FEP) were measured by the clearance method. Urinary KAL and KIN were determined by direct-RIA. Urinary kininase (total, I and II) activities were measured by the kinin destroying capacity. Urinary PGE was measured by RIA. Following saline infusion, UV, UNaV, FEP, KAL, KIN and PGE significantly increased in both NT and EHT. The increases of UV, UNaV, FENa, FEP and KAL were remarkably greater in EHT than each in NT, while no significant difference was found in the increment of PGE between NT and EHT. Significantly positive correlations were observed between PGE and KAL or KIN in NT (r = 0.889, p less than 0.005; r = 0.574, p less than 0.05, respectively), but not in EHT. From these results, it was concluded that the exaggerated natriuresis observed in EHT following infusion may be significantly related to the augmentation of renal KAL-KIN system, but was not directly related to PGE.

Diuresis↗