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Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

At least 631 records · Page 35Linked to original sources

[A case of carcinoma of the prostate presenting as abdominal mass].

A 69-year-old man was hospitalized for bilateral abdominal masses and constipation on October 31, 1986. Physical examination revealed firm, rough, movable, hard masses of over fist size, in the bilateral lower abdomen. CT scan disclosed two large masses in the pelvis. The prostate was of walnut size, rough and elastic firm on rectal examination. The serum acid phosphatase was elevated. Needle biopsy of the prostate and open biopsy of the mass showed a poor differentiated adenocarcinoma. Treatment with diethylstilbestrol diphosphate, 5-fluorouracil, estramustine sodium phosphate, chlormadinone acetate, 1-la-tetrahydrofuryl-5-fluorouracil, and cyclophosphamide was effective. The masses-metastasis of intrapelvic lymph nodes have shrunk and serum acid phosphatase has fallen to the normal level. In April 1987, the patient left hospital, and as of October 1987, he is still alive. This case indicates the presence of an unusual type of prostatic carcinoma in which huge lymph node metastasis occurs.

Adenocarcinoma↗

Detection of early myocardial infarction in formalin-fixed, paraffin-embedded tissue.

Whether the early infarct area in formalin-fixed, paraffin-embedded tissue could be delineated by the immunohistochemical method using myoglobin-antibody was studied in 23 pig hearts without collateral circulation. Five hearts were examined at 20 minutes, 2 hours, 4 hours, and 6 hours after occlusion of the distal one third of the left anterior descending coronary artery, respectively. Three pigs were killed 24 hours after occlusion. Heart rate and aortic pressure before and after occlusion did not change in any groups. The subepicardial and subendocardial regional blood flows were reduced to almost zero in all hearts after occlusion (0.88 +/- 0.10 to 0.02 +/- 0.02 mL/g/min). Slight myoglobin defects in the ischemic tissue were noted in the five pigs examined 2 hours after occlusion and definite myoglobin defects were detected in all pigs examined at 4, 6, and 24 hours after occlusion. Nitrotetrazorium blue stain of myocardial tissue before formalin fixation showed slight demarcation of the ischemic area at 4 hours after occlusion and definite demarcation at 6 and 24 hours after occlusion. Slight demarcation was noted at 2 hours after occlusion in Masson trichrome stain and 4 hours after occlusion in the hematoxylin-eosin stain. However, definite demarcation of the ischemic area was seen in Masson trichrome stain only at 24 hours after occlusion and was not noted in hematoxylin-eosin stain even at 24 hours after occlusion. Our previous electron microscopic study revealed that, in the pig heart, irreversible cellular damage was transmurally seen at two hours after occlusion of the coronary artery. Therefore, a definite myoglobin defect reflects irreversible cellular damage such as infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Reno-submandibular axis controls release of extrarenal inactive renin.

The mechanisms causing the release of plasma inactive renin (PIR) area still unclear. We have investigated the role of the kidney in the release of trypsin-activable PIR from extrarenal sources in the rat, with special reference to the submandibular gland. The activation of PIR was performed by incubation with 20 mg/ml trypsin at 4 degrees C for up to 10 min; the reaction was then terminated by addition of 20 mg/ml of soybean trypsin inhibitor. Bilateral nephrectomy resulted in a gradual, marked, sex-independent increase in PIR concentration, reaching levels 4.5 times higher than basal in 24 h (time 0: 14.8 +/- 1.0 ng/ml per h; 24 h: 66.8 +/- 3.4 ng/ml per h, mean +/- s.d., P less than 0.001). This increase was not altered by the concomitant intravenous infusion of pressor doses of either angiotensin (Ang) II (30 ng/min) or pure mouse submandibular renin (a 20-ng intravenous bolus followed by intravenous infusion at the rate of 50 ng/h) for 4 h, but was completely prevented by prior removal of the submandibular glands, in which no activity of active renin and no inactive renin was detected. These results suggest that the post-nephrectomy increase of PIR is not dependent on feedback mechanisms of the suppressed renin-angiotensin system, but is controlled by the presence of submandibular glands in the rat.

Animals↗

[Evaluation of immunosuppressive acid protein in genitourinary malignant diseases].

Clinical significance of serum immunosuppressive acid protein (IAP) was evaluated on the basis of experience on 55 patients with genitourinary malignant disease and 49 control patients. Although the measurement of serum level of IAP is not good enough to diagnose early stage of cancer, patients with 800 micrograms/ml or more of serum IAP can be suspected to have malignant diseases. With the exception of prostatic cancer, both mean serum level and positive rate of IAP were higher in patients with high stage of disease than in those with low stage. Furthermore, on an individual basis, serum level of IAP was elevated with the progress of malignant tumor and was reduced with effective treatment. Thus, serum IAP is considered as a valuable nonspecific tumor marker in monitoring clinical course of genitourinary malignant diseases except for cancer of the prostate. In patients with advanced prostatic cancer, no definite correlation was seen between serum IAP and stage of disease, histopathological finding or serum prostatic acid phosphatase.

Adult↗

[Retrograde nephrostomy for percutaneous nephrolithotomy].

Between June, 1985 and November, 1986, 25 patients at our institute underwent retrograde nephrostomy placement to provide percutaneous access to the kidney for percutaneous nephrolithotomy (PNL) of renal or upper ureteral calculi. Overall, retrograde nephrostomy was successfully completed through the desired calyx in 80% of the patients and calculi were successfully removed by the subsequent PNL. There were 5 failures primarily due to wrong indication and inexperience with the technique. The procedures had been done without significant complications in this series including unsuccessful cases. On the basis of our experiences, it is practically important for successful retrograde nephrostomy to fix the tip of the catheter firmly in the desired calyx until the puncture wire is advanced into the renal parenchyma. It is also important to aim the puncture wire at the skin in a favorable direction to avoid adjacent visceral penetration. Retrograde nephrostomy is a useful aid for percutaneous calculus removal particularly in patients with nondilated intrarenal collecting systems, because this new technique allows precise tract placement to the kidney required for efficient calculus manipulation with less risk than that associated with conventional percutaneous nephrostomy.

Adult↗

[Effect of oral administration of L-dopa on the plasma levels of growth hormone-releasing hormone (GHRH) in normal subjects and patients with various endocrine and metabolic diseases].

The responses of plasma growth hormone-releasing hormone (GHRH) and growth hormone (GH) to oral administration of L-dopa were studied in normal subjects and patients with various endocrine and metabolic diseases to clarify the pathophysiological role of the GHRH-GH axis. In normal subjects, the plasma GHRH concentration was increased from the basal value of 9.8 +/- 1.4 pg/ml (mean +/- SE) to 34.8 +/- 3.1 pg/ml at 30 approximately 90 min after oral administration of 500 mg L-dopa, followed by a rise of GH release (plasma GH level from less than 1 ng/ml to 21.7 +/- 4.7 ng/ml) in most cases, indicating that L-dopa stimulates GH secretion via hypothalamic GHRH. On L-dopa administration, no apparent increases in both plasma GHRH and GH concentrations were observed in patients with hypothalamic hypopituitarism, whereas GHRH administration induced almost normal GH response. In patients with acromegaly, the plasma levels of GHRH remained stationary after the L-dopa administration and did not correlate with plasma GH levels. In subjects with simple obesity, the responses of plasma GHRH (peak 13.2 +/- 1.2 pg/ml) and GH (peak 4.3 +/- 1.7 ng/ml) to L-dopa were significantly lower than those in normal subjects (p less than 0.01). In patients with primary hypothyroidism, peak levels of plasma GHRH (12.6 +/- 1.3 pg/ml) and GH (2.4 +/- 0.6 ng/ml) were significantly lower than those in normal subjects (p less than 0.01). In patients with non-insulin dependent diabetes mellitus (NIDDM), the responses of GHRH and GH were divided into 2 groups; in the responder the peak values of GHRH and GH were 19.4 +/- 8.6 pg/ml and 12.2 +/- 1.4 ng/ml and in the low or non responder 14.7 +/- 1.5 pg/ml and 2.0 +/- 0.6 ng/ml, respectively. Between both groups, there was a significant difference in the values of fasting blood sugar and HbA1 and mean suffering period. These findings suggest that GH secretion evoked by the L-dopa administration is induced by GHRH released from the hypothalamus, and impairment of GH secretion associated with simple obesity, primary hypothyroidism, or NIDDM may be in part attributed to insufficiency of GHRH release from the hypothalamus, and indicate that L-dopa test is clinically useful for evaluating the ability of intrinsic GHRH release in such diseased states.

Adolescent↗

[Roles of kidney and submandibular gland in the release of rat plasma inactive renin].

In this study we outlined the development of an enzymatic technique to activate plasma inactive renin by trypsin in rat plasma. Using this method, we reported the releasing mechanism of the trypsin-activable inactive renin which has not yet been clarified. Adult male Wistar rats (260-300 g) were kept on regular diet (Na: 260 mg/100g) unless explained and underwent operation under pentobarbital anesthesia (50 mg/kg). Blood samples were obtained from conscious rats through the cannulae, which had been inserted into the left femoral arteries 24h before the experiments. After addition of excessive renin substrate which had been obtained from the 24 h-nephrectomized rat plasma, renin was measured by the commercial RIA-kit (Dainabot). Trypsin (Worthington) treatment (20 mg/ml plasma for 10 min at 4 degrees C) was followed by addition of SBTI (Sigma) (20 mg/ml plasma). This condition maximally increased the rate of angiotensin I generation and did not alter the Km or optimum pH of the renin reaction. In this condition, trypsin reaction was completely inhibited by adding these concentrations of SBTI. The molecular weight of inactive renin (51,000) in the normal rat plasma estimated by Sephadex G-100 column (Pharmacia) was the same as that in the nephrectomized rat plasma. In conclusion, trypsin treatment of plasma (20 mg/ml plasma for 10 min at 4 degrees C) followed by SBTI (20 mg/ml plasma) was justified for trypsin activation of rat plasma. Using this method, we investigated the changes in active and inactive renin after bilateral nephrectomy in the salt-depleted rat. Active renin decreased rapidly after bilateral nephrectomy with a half life of 23.6 +/- 4.0 min. Inactive renin, on the other hand, increased gradually and reached to a plateau 24 h after bilateral nephrectomy, and was kept unchanged during the following 24 h. The infusion of mouse submandibular gland active renin or angiotensin II could not prevent the increase of plasma inactive renin in the nephrectomized rat. These suggest that there may be no feedback mechanisms between plasma inactive and active renin or angiotensin II. Furthermore, we investigated the organ-related sources of plasma inactive renin which markedly increased after total nephrectomy. Simultaneous removals of submandibular glands but not of adrenal glands completely prevented the postnephrectomy increases of plasma inactive renin. But, removals of submandibular glands or adrenal glands alone were followed by no changes in the basal levels of plasma inactive renin.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Bioelectric responses of sea urchin eggs inseminated with oyster spermatozoa: a sperm evoked potential without egg activation.

Multiple oyster spermatozoa can enter sea urchin eggs with or often without fertilization membrane formation (Osanai and Kyozuka, 1982). In the present work, electrical responses of sea urchin (Temnopleurus hardwicki) eggs inseminated with oyster (Crassostrea gigas) sperm were examined and correlated to the failure of monospermy and egg activation. With diluted sperm, a transient depolarization of the membrane with a constant pattern appeared repeatedly and discretely, and the depolarizations (sperm evoked potentials, SEPs) were not associated with fertilization membrane elevation. With dense sperm, the SEPs occurred consecutively, and sometimes an assembled consecutive depolarization was followed by an activation potential associated with cortical granule discharge. When the membrane potential was artificially held at positive levels, the frequency of SEPs was strongly suppressed but not completely blocked. The present results indicate that an individual heterologous spermatozoon neither produces a depolarization sufficient to block additional sperm entry, nor stimulates egg activation, and that simultaneous entries of multiple heterologous spermatozoa, as possibly reflected by the assembled consecutive depolarizations, induce cortical granule discharge and egg activation.

Animals↗

Enhanced degradation of low density lipoprotein in human monocyte-derived macrophages associated with an increase in its free fatty acid content.

Low density lipoprotein (LDL) rich in oleic acid (designated FFA-rich LDL) was produced by the reconstitution technique. FFA-rich LDL, like acetyl LDL, moved faster than native LDL in agarose gel electrophoresis. While FFA-rich LDL was observed to degrade far less than natural LDL in lymphocytes, its degradation in monocyte-derived macrophages was three times higher than that of natural LDL or LDL reconstituted without the addition of oleic acid. A competitive study showed that the catabolism of FFA-rich LDL in macrophages may be influenced by systems other than the acetyl LDL receptor.

Cells, Cultured↗

Benign osteoblastoma of the temporal bone of an infant.

Benign osteoblastoma is a rare neoplasm of bone tissue most commonly involving the vertebral column and long bones. Occurrence in the calvarium is extremely rare, and no cases in infants have previously been described. We report a case of benign osteoblastoma occurring in the temporal squama of an infant. The clinical features of this type of tumor occurring in the calvarium are briefly discussed.

Age Factors↗

Long-term prognosis of tuberous sclerosis with epilepsy in children.

A follow-up study was performed on 40 children with tuberous sclerosis and epilepsy. In 68% of the patients with infantile spasms and 73% of those without them, complex partial seizures were observed. Thus, patients with tuberous sclerosis are subject to not only infantile spasms but also complex partial seizures. Patients with infantile spasms showed mental retardation more often than those without. Seizures which had evolved from infantile spasms were more difficult to control than those which had not. The prognosis of infantile spasms associated with tuberous sclerosis was better than that of prenatal group other than tuberous sclerosis. Forty percent of the 40 cases showed asymmetry on EEG, and the asymmetry tended to disappear as the patients grew up.

Adolescent↗