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Biomedical subjects

T Iwanaga

Publications and source records attributed to T Iwanaga.

At least 343 records · Page 19Linked to original sources
PubMed1986

Immunohistochemical demonstration of nerves in the predentin and dentin of human third molars with the use of an antiserum against neurofilament protein (NFP).

Immunohistochemistry by use of an antiserum against neurofilament protein (NFP) was applied for staining nerve fibers in the predentin and dentin of human third molars. By devising methods for fixation, decalcification and immunostaining, nerve fibers were clearly and specifically demonstrated in thick (more than 50 micron) sections of teeth. Numerous NFP-positive fibers were distributed in the predentin throughout the coronal region, while a few positive fibers penetrated only a short distance into the dentin. The NFP-positive nerve fibers in the predentin took transverse and complicated courses across, rather than penetrating longitudinally through, the dentinal tubules. Pain sensation in the teeth might be attributable to these complex nerve fibers showing two- or three-dimensional extensions.

Adult↗
PubMed1986

A cohort study on second malignancies in gastrectomized patients with gastric cancer. I. Second malignancies other than cancer of the gastric remnant.

In a retrospective cohort study, a total of 235 (2.32 per cent) second malignancies were clinically observed in 10,138 patients during the average 8.8-year follow-up period. The patients had undergone gastrectomy for gastric cancer during 1960-1975, in seven different institutions. This observed number was smaller than the expected one of 340.9 (p less than 0.01). Among the 235, cancers of the gastrointestinal tract (111) were the most frequent and followed by respiratory (54) and urogenital (25) cancers. Twelve cases of malignant lymphoma and five of leukemia were also noted. With regard to adjuvant chemotherapeutic agents such as mitomycin-C (MMC), 5-fluorouracil (5FU) or its derivative Tegafur, and cyclophosphamide (EDX), no significant differences in the rate of second malignancies were obtained between the chemotherapy and non-chemotherapy groups. The occurrence rate of second malignancies tended to be higher in the Billroth II group than in the Billroth I, the significance of which is yet to be determined.

Adult↗
PubMed1986

A cohort study on second malignancies in gastrectomized patients with gastric cancer. II. Second malignancies in the gastric remnant.

In a retrospective cohort study, a total of 22 (0.22 per cent) carcinomas of the gastric remnant were clinically observed, as second malignancies, in 7,672 patients during the average of a 9.4-year follow-up period. All had undergone distal subtotal gastrectomy for gastric cancer from 1960-1975 in seven different institutions. Of 22 carcinomas of the gastric remnant, 5 were at the anastomotic site, 14 distant from the anastomosis; the location was unknown in three. All five carcinomas of the anastomotic site occurred after Billroth II operation. Time intervals between the first operation and the occurrence of second cancer varied from two to 21 years. With regard to the administration of adjuvant chemotherapeutic agents such as mitomycin-C (MMC), 5-fluorouracil (5FU) or its derivative Tegafur, no significant differences in the rate of second malignancies were obtained between the chemotherapy and non-chemotherapy groups. The occurrence rate of cancer of the gastric remnant between Billroth I and Billroth II groups showed no statistically significant difference, although it did tend to be slightly higher in the latter.

Adult↗
PubMed1986

Eradication of esophageal varices with repeated injection sclerotherapy in inoperable patients.

Esophageal varices in 50 cirrhotic patients were treated with repeated injection sclerotherapy. Eradication of varices was achieved in 27 patients (54.0%) with a mean of 4.5 injections (range 2-12) after a mean period of 3.1 months (range 1-11). There was no variceal bleeding in these 27 patients once eradication had been achieved, with a mean follow up period of 5.6 months, although bleeding occurred in 5 of the same group before eradication of the varices had been achieved, during an average of 3.1 months, and in 6 of the remaining 23 patients (10 episodes) with residual varices after a mean of 4.7 injections (range 2-12) in a mean period of 12.2 months (range 1-33). Esophageal varices can thus be eradicated with repeated injections and bleeding from recurrent esophageal varices can be prevented in many patients after eradication has been achieved.

Adult↗
PubMed1986

PHI structural requirements for potentiation of glucose-induced insulin release.

Immunoreactive PHI was detected in rat pancreas. The potentiating effect of 10(-9) M PHI upon insulin release from the isolated perfused rat pancreas was significant and most consistent when 250 mg% glucose was present in the perfusion medium. PHI(1-15) retained a substantial potentiating effect on insulin release, while PHI(14-27) was essentially inactive. Replacement of amino-terminal decapeptide portion of the PHI molecule with the corresponding part of VIP resulted in a drastic decrease of the potentiating effect of PHI on insulin release. 10(-8) M PHI(14-27) substantially diminished the potentiation by 10(-9) M PHI while PHI(1-15) was without an inhibitory effect. The present results indicate that the PHI active site for potentiation of glucose-induced insulin release resides in the amino-terminal segment of the molecule but requires the carboxyl terminal segment primarily for binding to exhibit full biological activity.

Animals↗
PubMed1986

Immunochemotherapy in human hepatocellular carcinoma using the streptococcal agent OK-432.

Twenty-one patients with nonresectable hepatocellular carcinoma (HCC) received intraarterial infusion chemotherapy of Adriamycin (Adria Laboratories, Columbus, Ohio) via an indwelling catheter in the hepatic artery. Additional intratumoral injection therapy of OK-432 (50 KE) was administered to ten of these 21 patients. Nine of the ten patients showed a remarkable decrease in lymphocyte count on the first day after therapy. In all of the patients with a decreased lymphocyte count, computed tomograms (CTs) demonstrated evidence of necrosis associated with a rapid decrease in alpha fetoprotein (alpha-FP). Blastogenesis of lymphocytes in peripheral blood induced by phytohemagglutinin (PHA) increased by 3.99 +/- 1.9 (mean +/- SE) times 4 weeks after therapy. On the basis of these results, we concluded that intratumoral injection therapy of OK-432 apparently produced initiation of necrosis in HCC by cell-damaging activity as well as by improvement of cell-mediated immunity.

B-Lymphocytes↗
PubMed1986

Immunohistochemical demonstration of S-100 protein in fibroblast-like cells of the guinea-pig heart.

The immunocytochemical localization of S-100 protein was examined in the hearts of adult guinea-pigs. In addition to Schwann cells, adipose cells and chondrocytes, fibroblast-like cells densely distributed in the cardiac skeleton, all of the four valves and tendinous chordae were immunoreactive for S-100 protein. The S-100-positive fibroblast-like cells were conspicuously rounded in shape and extended their thin, thread-like cell processes in opposite directions; the cytoplasm was restricted to perinuclear region. In these morphological features, the cells were distinctly different from ordinary fibroblasts which were immunonegative for S-100 protein. Electron microscopic observation revealed that the S-100-like immunoreactivity was distributed throughout the cytoplasmic matrix in the cell body and processes, but absent from the nuclei and cell organelles. The significance of the S-100 immunopositive fibroblast-like cells was discussed in relation to cartilaginous tissues, which have the potential to form in the region of the cardiac skeleton and valves under both normal and abnormal conditions.

Animals↗
PubMed1986

Immunohistochemical localization of urotensins I and II in the caudal neurosecretory neurons of the carp Cyprinus carpio and the sharks Heterodontus japonicus and Cephaloscyllium umbratile.

Using antisera to urotensins I and II (UI and UII), in the carp, Cyprinus carpio, three types of caudal neurosecretory neurons were identified: those with both UI- and UII-immunoreactivities, those with only UI-immunoreactivity and those with only UII-immunoreactivity. The last type of neurons exceeded the other types in number, while neurons immunoreactive with both UI and UII antisera were relatively few. The axons of neurons of these three types terminated around the capillaries in the urophysis. In the cat shark, Heterodontus japonicus and the swell shark, Cephaloscyllium umbratile, two types of neurons were identified: those with both UI- and UII-immunoreactivities and those with only UII-immunoreactivity. Neurons of the former type were greater in number than the latter. The axons of neurons of both types terminated in the neurohemal areas.

Animals↗
PubMed1986

[Surgical treatment of scirrhous carcinoma of the stomach].

In surgical treatment of scirrhous gastric carcinoma, the important points are as follows: Extensive resection of the stomach should be performed. Left epigastric evisceration and extensive dissection of lymph nodes including the para-aortic nodes should be done for sufficient extirpation of the tissues around the stomach. Adjuvant therapy is recommended for intensive chemotherapy immediately after surgery and for postoperative long-term maintenance therapy. Development of a combined therapy which takes into account the characteristics of scirrhous gastric cancer is hoped for in the future.

Adenocarcinoma, Scirrhous↗
PubMed1986

[Adjuvant therapy of gastric cancer in the literature from 1980-1984].

A literature survey was conducted regarding adjuvant therapy for surgical cases of gastric cancer. A total of 66 papers published on a world wide basis in the 5 years from 1980 through 1984 were collected. Forty-three papers (65%) were published by Japanese researchers, of which only 17 were written in English. Adjuvant therapy was regarded as being effective in about 60% of the papers. The main drugs achieving effective adjuvant chemotherapy were mitomycin C (M), 5-FU (F), Tegafur, MF, and MFC(M+F+cytosine arabinoside). The cases yielding an effective result were mainly patients who had undergone radical surgery for stage II or III gastric cancer. The doses used for adjuvant chemotherapy were slightly less than the doses used for chemotherapy of advanced gastric cancer in internal medicine. The incidences of adverse effects of the adjuvant chemotherapy were almost the same as those encountered in internal medicine, and severe complications occasionally developed. Some recent reports observed that efficacy of adjuvant chemotherapy was increased by intensive therapy in the immediate postoperative period and by maintenance therapy over the long term.

Antineoplastic Agents↗
PubMed1986

[Indications for surgical resection of lung metastasis from breast cancer--considerations according to the mechanism of extension of metastases].

The indications for surgical treatment of lung metastasis from breast cancer were analyzed according to the extension mode of the metastasis. Of lung lesions that seemed operable roentgenographically at the time of their first manifestation, about half developed new metastatic nodules within six months thereafter, while the other half did not do so for more than two years. No clinicopathologic findings at the time of mastectomy were helpful to differentiate the two groups, except that a cancer-free interval of less than a year fell exclusively into the former group. Thus, the only way to determine the indications is to watch the lesions for six months with chemo-endocrine therapy.

Breast Neoplasms↗
PubMed1986

[An effect of the intra-arterial infusion of angiotensin II in the chemotherapy of human hepatic cancer].

Changes in the distribution of hepatic arterial blood flow following the intra-arterial infusion of a vasoactive drug, angiotensin II (AT-II) were studied in human hepatic cancers using extremely short-lived RI (81mKr: half-life, 13 sec), with a view to applying the drug to intra-arterial chemotherapy. The arterial blood flow in the tumor region increased gradually after continuous AT-II infusion, and reached a peak at approximately 100 seconds, thereafter showing a gradual decreasing tendency. Blood flow in the non-tumor region decreased gradually and reached a minimum at about 100 seconds, subsequently showing a tendency to increase. As a result, the time course of arterial blood flow in both regions exhibited a good symmetry. The peripheral blood pressure rose to a value 1.5 times higher than the preinfusion value after 3 minutes, maintaining a constant value thereafter during the infusion of AT-II. In other words, the T/N ratio showed a peak before the peripheral blood pressure reached a plateau, and exhibited a tendency to decrease at that plateau. The difference in response between routes (intra-arterial and intravenous) of AT-II infusion was studied in 5 patients. The intra-arterial infusion of AT-II showed a much greater increase in tumor blood flow than intravenous infusion. It is considered that intra-arterial infusion chemotherapy with local use of AT-II improves the accessibility of chemotherapeutic drugs to tumors.

Angiography↗
PubMed1986

[Secondary malignancies after gastrectomy for gastric cancer].

In patients who have undergone gastrectomy for gastric cancer, the use of adjuvant chemotherapy has now become very widespread in Japan. The possibility of secondary malignancies in these patients emerges as a long-term effect of these therapeutic agents. This collaborative study was done to examine the possibility of secondary malignancies resulting from both operative methods and anticancer agents at the surgical departments of seven major institutions in Japan. The study was carried out using questionnaires for all patients with gastric cancer who had undergone gastrectomy between 1960 and 1975 in those hospitals and who had survived more than one year after gastrectomy. A total of 235 secondary malignancies (2.32%) were noted among 10,138 gastrectomized patients, and 22 cancers of the gastric remnant (0.29%) were recorded among 7,672 subtotal gastrectomized cases. Cancers suspected to be recurrent gastric cancer were all excluded. As to anticancer agents, Mitomycin C (MMC), 5-Fluorouracil (5-FU) or Tegafur and Cyclophosphamide (EDX) were analyzed. The occurrence rate of secondary cancers in gastric cancer patients was calculated in many instances by dividing the actual number of secondary cancers by the total time at risk (person-years). Patients with gastric cancer who had undergone gastric resection revealed a lower incidence of secondary malignancies than had been expected. The most common secondary cancers were those occurring in the digestive system, followed by those of the respiratory system. With regard to MMC, 67 secondary cancers (2.21%) occurred in the MMC group and 168 cancers (2.36%) in the non-MMC group. Although the overall incidence of secondary cancers showed no difference between MMC and non-MMC groups, secondary cancers of the digestive system were less common in the MMC group than in the non-MMC group. A total of 22 cancers originated in the gastric remnant out of 7,672 subtotally resected stomachs. The interval between the first operation and cancer of the gastric remnant varied greatly without showing any detectable trend. Nine cancers were observed to involve the anastomotic site while 14 did not involve the anastomotic site. The incidence of cancer of the gastric remnant tended to be slightly higher with the Billroth II method than in the Billroth I method, but there was no difference in the site of secondary malignancy between the two groups.

Adult↗
PubMed1986

[Surgical treatment of intermediate-stage gastric cancer].

Gastric cancers for which either the invasion depth of the stomach wall layers is moderate or the extent of lymph node metastasis is moderate were defined as carcinomas of intermediate-stage. In consideration of the clinico-pathological characteristics of these intermediate-stage gastric cancers, the therapeutic methods for the cancers were studied. It was concluded that since intermediate-stage gastric cancer is a kind of advanced cancers, the most desirable surgical approach will be a radical surgical operation and an adequate adjuvant therapy.

Antineoplastic Agents↗