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Biomedical subjects

T Iwanaga

Publications and source records attributed to T Iwanaga.

At least 325 records · Page 18Linked to original sources
PubMed1987

Distribution of nerve fibers immunoreactive to neurofilament protein in rat molars and periodontium.

The distribution of nerve fibers in molars, periodontal ligament and gingiva of the rat shows a complex pattern. Decalcified material including the alveolar bone was sectioned in three different planes and stained by means of immunohistochemistry for detection of the neurofilament protein (NFP); the immunoreactive neural elements were clearly visualized in three-dimensional analyses. NFP-positive nerve fibers formed a subodontoblastic plexus in the roof area of the dental pulp; some of them entered the predentin and dentin directly through the dentinal tubules. This penetration was found mainly in the pulp horn, and was limited to a distance of about 100 micrometers from the pulpo-dentinal junction. In the periodontal ligament, NFP-positive nerve fibers were found densely distributed in the lower half of the alveolar socket. Two types of nerve terminals were recognized in the periodontal ligament: free nerve endings with tree-like ramifications, and expanded nerve terminals showing button- or glove-like shapes. The former tapered among the periodontal fibers, some even reaching the cementoblastic layer. The latter were located, frequently in groups, within the ligament restricted to the lower third of the alveolar socket. A well-developed plexus of NFP-positive nerves was revealed in the lamina propria of the free gingiva, the innervation being denser toward the epithelium of the gingival crevice. The characteristic distribution of NFP-immunoreactive nerve fibers revealed in this study is discussed in relation to region-specific sensations in the teeth and surrounding tissues.

Animals↗
PubMed1987

Serotonin-immunoreactive cells of peculiar shape in the urethral epithelium of the human penis.

The present study deals with endocrine-like cells in the urethra of human penis. A large number of basal-granulated cells immunoreactive for serotonin were dispersed in the urethral epithelium. No cellular elements were stained positively with antisera against bioactive peptides. The serotonin-immunoreactive cells consisted of a small oval perikaryon and slender processes, and resembled neurons in shape. An apical process reached the urethral lumen. The basal processes frequently branched out in a dendritic fashion, some running laterally for a considerable distance. The number of cells immunoreactive for serotonin was remarkably reduced in subjects over 60 years of age.

Aged↗
PubMed1987

Validity of ultrasonic duplex system for measurement of the portal blood flow in patients with liver disease.

The validity of an ultrasonic duplex system for assessment of portal blood flow was clinically investigated. The maximum portal blood flow velocity was measured using this system (X) in ten patients with liver disease, and data obtained were compared on patients simultaneously undergoing cineangiographic mapping of Lipiodol droplets released into the portal vein through an indwelling catheter (Y). A linear correlation between X and Y was statistically significant (r = 0.970, n = 13). The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.

Humans↗
PubMed1987

A transparent over-tube for endoscopic injection sclerotherapy and results in patients with esophageal varices.

This report describes our data regarding repeated injection sclerotherapy using a newly designed over-tube. We treated 17 consecutive patients with esophageal varices, (3 acute, 6 elective and 8 prophylactic). An intravariceal injection of 5 per cent ethanolamine oleate was administered, using a newly designed transparent over-tube containing a second lumen for a flexible injection needle. This over-tube provides an easier, safer, shorter-in-time method of sclerosing esophageal varices. One of the 17 patients died as a result of liver failure associated with advanced cirrhosis and a concomitant hepatoma. Eradication of esophageal varices was attained in the remaining 16 patients, after an average of 5.0 injections over an average period of 5.8 weeks (range: 3-7 injections during 3-11 weeks). No complications, such as esophageal perforation or aspiration pneumonia were encountered. Recurrent variceal bleeding has not occurred during the 9 months follow-up.

Adult↗
PubMed1987

Increase in thromboxane B2 and decrease in prostaglandin E2 and 6-keto-prostaglandin F1 alpha release into rat bronchoalveolar fluid as a consequence of cigarette smoking.

Rats were exposed to cigarette smoke once daily for 4 to 8 weeks. Bronchoalveolar lavage fluid was obtained from each animal and assayed for immunoreactive PGE2, TXB2 and 6-Keto-PGF1 alpha. Significant increase in TXB2 and decrease in PGE2 and 6-Keto-PGF1 a release into bronchoalveolar fluid as a consequence of cigarette smoking were observed. These changes of arachidonate metabolites in lung alveoli may account in part for bronchoconstriction induced by cigarette smoking.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Gene conversion-like events cause steroid 21-hydroxylase deficiency in congenital adrenal hyperplasia.

Genomic DNAs from twelve Japanese patients with steroid 21-hydroxylase [21-OHase; steroid 21-monooxygenase; steroid, hydrogen-donor:oxygen oxidoreductase (21-hydroxylating); EC 1.14.99.10] deficiency were analyzed by Southern blot hybridization. A 3.7-kilobase (kb) Taq I and a 1.7-kb Pvu II restriction endonuclease fragment that correspond to a 21-OHase B gene were absent from the DNA of two unrelated patients with the salt-wasting form of the disease. However, a 10.5-kb Bgl II fragment corresponding to the region encompassing the 21-OHase B gene was still present in these two patients. The genes encoding 21-OHase were cloned from one of these two patients, who was homozygous by descent for HLA-A26;B39;C4A3;C4B1;DR4. Restriction endonuclease mapping as well as partial nucleotide sequencing analysis revealed that the 21-OHase B gene of the patient has been converted to the pseudogene, 21-OHase A, as far as the critical 0.5-kb sequence was concerned. Thus, the defect was due to both chromosomes each carrying two copies of 21-OHase A pseudogene and lacking functional 21-OHase B gene.

Adrenal Hyperplasia, Congenital↗
PubMed1987

Regional therapy in the management of intrahepatic recurrence after surgery for hepatoma.

The significance of regional therapy against the intrahepatic recurrence for hepatocellular carcinoma (HCC) was evaluated. During the past 6 years, 101 patients who had radical operations for HCC (liver cirrhosis, 75%; chronic hepatitis, 22%) were followed. Forty-seven patients (47%) had recurrences; the liver was the site of first recurrence in 43 patients and distant site recurrence in four patients. In the patients where the liver was the recurrent site, 33 patients (77%) received regional therapies for an aggregate total of 60 times. Transcatheter arterial chemoembolization was chosen as the first preferred therapy against recurrence in the liver in 30 of 33 patients (91%). Postrecurrence survival of the patients treated with regional therapy was significantly better than disease-free survival (p less than 0.001). Disease-free survival after surgery, postrecurrence survival, and postsurgery survival were compared in the patients treated with regional therapy and untreated patients. Fifty per cent survival after recurrence of the treated patients was 27 months, and that of the untreated patients was 3 months. Postrecurrence survival (p less than 0.001) and postsurgery survival (p less than 0.01) of the treated patients were significantly better than those of the untreated patients. To obtain successful long-term survival after surgery for the cirrhotic patients with HCC, it is necessary to repeat active regional therapies against the recurrent liver.

Adult↗
PubMed1987

Ultrasonic duplex system to facilitate assessment of portal blood flow velocity.

The usefulness of an ultrasonic duplex system to assess portal blood flow was investigated. In a model involving a steady flow through a vinyl tube in agar, there was a significant linear correlation between the maximum blood flow velocity measured by this system (V-max) and the mean blood flow velocity calculated from the actually measured blood flow volume (V-mean), that is, V-mean = 0.53 X V-max was obtained (r = 0.994; n = 47). This equation was used to calculate the mean portal blood flow velocity by this system (V-dopp) in 10 patients with liver disease, and the findings were compared with data simultaneously obtained by cineangiographic mapping of Lipiodol droplets released into the portal vein through a catheter placed in situ at the time of surgery (V-cine). A linear correlation between V-dopp and V-cine was statistically significant (r = 0.970; n = 13), and the regression line was V-cine = 1.29 X V-dopp -2.11. The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.

Blood Flow Velocity↗
PubMed1987

Mechanism of penile erection in the dog. Pressure-flow study combined with morphological observation of vascular casts.

A pressure-flow study of the corpus cavernosum penis in the dog was performed during the flaccid, tumescent, erect and rigid stages. Perfusion was selectively made into the penile deep artery. The erect stage was induced with the local administration of papaverine hydrochloride, and the rigid stage by electrostimulation of the ischiocavernous muscle during the erect stage. Concurrently, vascular casts of the penis at each stage of erection were observed under a scanning electron microscope for the anatomical analysis of the mechanisms controlling cavernous pressure. In the pressure-flow study, it was demonstrated that a combination of decreased arterial resistance and restricted venous outflow was essential to both cause and maintain the erect state. The rigid stage was generated by contraction of the ischiocavernous muscle tightly compressing the crus penis. In the rigid stage, the cavernous pressure was elevated as high as five times the perfusion pressure; nevertheless, no backflow from the cavernous sinus to the deep artery was recognized. By use of the casts, it was confirmed that venous outflow restriction in the erect and rigid stages was due to compression of the postcavernous venules and penetrating veins in the tunica albuginea. The deep artery was occluded in the tunica albuginea in the casts made during the rigid stage, suggesting that the backflow from the corpus cavernosum penis to the deep artery was prevented by this occlusion. Therefore, in the rigid stage, the arterial and venous occlusion isolated the cavernous sinus from the systemic circulation; this mechanism seems to account for the maintenance of the extremely high cavernous pressure.

Algorithms↗
PubMed1987

Monolayer-forming islet cell culture from neonatal pig pancreas: using sequential treatment with EDTA-dispase and monoiodoacetic acid for preparation and purification.

A new method for the preparation and purification of a monolayer-forming islet cell culture from the neonatal pig pancreas is described. Single cell preparations of the pig pancreas were obtained by gently stirring the chopped pancreases in a medium containing sequential EDTA-dipase. Exposure of the cells to monoiodoacetic acid (10 micron) and BSA-gradient resulted in improved preparation, highly enriched in the endocrine cells. The cells were maintained in tissue culture medium 199 containing 5.5 mM D-glucose, with or without 0.1 mM 3-isobutyl-1-methylxanthine, or 16.7 mM D-glucose and 20% fetal calf serum. During a 6-day culture period, many small cell aggregates appeared in the media. The cell clusters attached to the bottom of the dish and formed monolayers. Provocative stimulation and radioimmunoassay for insulin showed the existence of numerous and viable B cells in the cell clusters. The other three types of islet cells were also demonstrated immunohistochemically in the cell cluster. It is concluded that this improved culture technique provides a useful tool for morphological and biochemical studies of islet cells and a potential source of material for transplantation of B-cells from the pancreas.

1-Methyl-3-isobutylxanthine↗
PubMed1987

[Ultrasonographic diagnosis of intracystic breast tumors].

Ultrasonography was performed on 1805 patients with breast diseases during the past 3 years and 20 (1.1%) intracystic tumors were detected. Among 20 intracystic tumors, 14 were finally diagnosed as benign and 6 as malignant. None of the 6 malignant lesions was judged as exclusively malignant and only 3 were considered as suspiciously malignant by ultrasonography. Ultrasonography is effective in making the location of intracystic tumors clear but not suitable for distinguishing malignant tumor from those that are benign. On the contrary, among the 6 malignant lesions, 5 were diagnosed as malignant and 1 as suspiciously malignant by aspiration cytology. Therefore, a combined examination of ultrasonography and aspiration cytology is a useful method for preoperative diagnosis of intracystic breast tumors.

Adenocarcinoma↗
PubMed1987

Radical radiation therapy of the thoracic esophageal carcinoma supplemented with or without salvage surgery.

From September 1977 to June 1985, 63 patients received radical radiotherapy for squamous cell carcinoma of the thoracic esophagus at the Center for Adult Diseases, Osaka. Fourty-six of them received radiation therapy alone (RT) and 17 received surgical treatment after irradiation (RT-OP) due to local recurrence or residual tumor. In these groups, 38 of 46 in RT only group and twelve of 17 in RT-OP group were selected for radiotherapy because of high risk for surgery or T3 lesion. For RT only group, tumor response after irradiation was the most important prognostic factor and a statistically significant difference of survival rates was detected between complete response (CR) group and non-CR group. Among RT-OP group, there were three five-year survivors in CR group (n = 8) after irradiation while no five-year survivor in non-CR group (n = 9). Tumor response after radical radiation therapy seems to show the indication for the salvage surgery in high risk or T3 patient.

Aged↗
PubMed1987

[Erectile mechanism studied using penile vascular casts in the dog].

The possible mechanism of penile erection was discussed based on the findings obtained by the scanning electron microscope observations of the penile vascular casts in the dog. Polsters protruding into the lumen of the distal helicine arteries regulate blood flow into the cavernous spaces. The drainage veins from the corpus cavernosum penis arose on the dorsal surface and crept on the corpus until changing direction perpendicularly. This suggested that these veins were efficiently compressed between the tunica albuginea and the corpus cavernosum penis during erection. For a high pressure to be maintained in the cavernous spaces during erection, a closed system separated from the systemic circulation must be required.

Animals↗
PubMed1986

Fibrinolysis in patients with acute promyelocytic leukemia and disseminated intravascular coagulation during heparin therapy.

Two patients diagnosed as having acute promyelocytic leukemia (APL) and disseminated intravascular coagulation (DIC) were closely followed by serial fibrinolysis and coagulation studies from the day of admission until completion of the first course of chemotherapy. One patient was treated with intravenous heparin and Trasylol (Bayer AG, West Germany) and the other received heparin therapy without Trasylol. In Patient 1, hyperfibrinolytic activity, not observed during the administration of Trasylol, developed with its discontinuance. In Patient 2, hyperfibrinolysis was observed coincidentally with a decrease in APL cells due to chemotherapy. These results indicate that hyperfibrinolysis in APL is not associated with DIC.

Adult↗
PubMed1986

The significance of the fibrin/fibrinogen degradation product in serum of carcinoma patients with hematogenous metastasis.

Fibrin/fibrinogen degradation product (FDP) was measured in 270 cases with various carcinomas. An elevation of FDP (5 micrograms/ml or more) was observed in 68 cases (25%). Of the 68 elevated FDP cases, 5 (82%) were inoperable or received nonradical resection. Forty of those 56 cases (71%) showed hematogenous metastasis. FDP in those cases which showed hematogenous metastasis was found to be due to fibrinolysis accompanied by consumption coagulopathy.

Blood Coagulation↗