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Biomedical subjects

M Kitano

Publications and source records attributed to M Kitano.

At least 235 records · Page 13Linked to original sources
PubMed1986

Role of angiotensin II in the pathogenesis of hyperdipsia in chronic renal failure.

The relation of thirst to the renin-angiotensin system was examined in 38 patients with chronic renal failure receiving hemodialysis treatment. They were classified into three groups, ie, group 1 (19 patients), no or modest thirst; group 2 (13 patients), moderate thirst; and group 3 (six patients), excessive thirst. The plasma renin activity, plasma angiotensin II levels, and interdialytic weight gains of groups 1 to 3 significantly increased in a progressive manner with intensity of thirst. The hyperdipsia experienced by four patients in group 3 ameliorated after administration of an angiotensin-converting-enzyme inhibitor. The hyperdipsia of some patients with chronic renal failure therefore appears to be mediated by increased production of endogenous angiotensin II.

Adult↗
PubMed1986

Distribution of demyelinating lesions in pontine and extrapontine myelinolysis--three autopsy cases including one case devoid of central pontine myelinolysis.

Three autopsy cases of pontine and extrapontine myelinolysis are reported; one, a malignant lymphoma in a man of 66 years, the other an alcoholic liver cirrhosis in a man of 54 years, and an esophageal cancer in a woman of 68 years who presented only with extrapontine myelinolysis, but lacked central pontine myelinolysis (CPM). The extrapontine lesions in these three cases revealed a characteristic and common localization; they occurred mostly in the bundles of myelinated fibers in the gray matter, such as in the pons, basal ganglia, and thalamus; and in the white matter surrounded by massive gray matter, such as the deeper layers of the cortex and subjacent white matter of the crowns and sides of the cerebral gyri, the white matter of the cerebellar folia and internal, external, and extreme capsules. Therefore, the third patient was classified as a subtype of pontine and extrapontine myelinolysis, which may be called the "extrapontine form" because of absence of CPM. Moreover, bilateral demyelination of the mamillary body was found in all cases, and laminar cortical astrocytosis and necrosis similar to Morel's cortical laminar sclerosis in two of them. From the clinical and pathologic findings, the significance of the changed osmolarity of the blood as a cause and the importance of some specificity of the tissue architecture in the pathogenesis are discussed.

Aged↗
PubMed1986

Role of the thymus in propylnitrosourea-induced thymic lymphomagenesis in F344 rats.

The role of the thymus in propylnitrosourea (PNU)-induced thymic lymphomagenesis was studied in F344 rats with genetically determined high susceptibility. The thymus was absolutely required for thymic lymphomagenesis, since thymectomy prior to or after PNU treatment abolished lymphomagenesis, whereas grafting of a normal neonatal thymus before PNU treatment restored it. Exposure to PNU for 42 days resulted in the appearance of potentially lymphomatous cells first in the thymus, and overt T-lymphomas subsequently appeared. Such cells seemed to be thymus-dependent, since intrathymic transfer of the thymus cells from 42-day PNU-treated rats induced T-lymphomas much more efficiently than intravenous transfer. Further, grafting of the thymus from 42-day PNU-treated rats into thymectomized rats resulted in T-lymphomas of donor origin without additional PNU treatment. Cells from the spleen or bone marrow from the same donors did not give rise to T-lymphomas irrespective of the route of cell transfer and sublethal irradiation of the recipients. Morphologically atypical cell foci were detected first on the 28th day in the thymus and were most pronounced during the 35th-42nd days. Therefore, the thymus is the essential organ in which the early events of PNU-induced rat T-lymphomagenesis take place.

Animals↗
PubMed1985

Decrease in human growth hormone (HGH) levels during transsphenoidal surgery for acromegaly as a guide for prognosis.

To evaluate the clinical significance of human growth hormone (HGH) dynamics during transsphenoidal microsurgery for acromegaly, serial HGH levels during the surgery were compared with the post-operative basal HGH levels in 15 acromegalic patients, retrospectively. In all patients, in whom the HGH level immediately after tumor resection was reduced below 5 ng/ml or the decreasing rate which stood for the magnitude of decrease of HGH during resection procedure was above 80%, postoperative permanent HGH levels fell to below 5 ng/ml, namely, within the normal range. The rapid radioimmunoassay (RIA) of HGH was developed by the use of high affinity antibody in order to inform the surgeons of plasma HGH levels quickly during the surgery. It is now possible to know HGH levels about 1 hour after submitting the samples. It was verified that HGH levels measured in the rapid RIA correlated well with those obtained in the conventional way. The rapid RIA method was applied to 6 patients and the correlation between HGH levels during the surgery and post operative levels was also studied prospectively. The results were essentially identical to those in a retrospective study. It was suggested that the HGH level immediately after tumor resection and the extent of the decrease in HGH during the resection procedure were good indicators of the prognosis of surgical results in acromegaly and the rapid RIA method was useful in order to judge HGH levels quickly during the surgery.

Acromegaly↗
PubMed1985

Light and electron microscopic studies of perineural invasion by esophageal carcinoma.

Light and electron microscopic findings on perineural invasion by human esophageal squamous cell carcinoma are reported. Perineural invasion was observed histologically in 30 of a total of 129 cases (23%) of esophageal squamous cell carcinoma and in 11 of the 24 cases (46%) in which tumors infiltrated other organs by passing through the esophageal adventitial layer. Electron microscopic observation showed that the perineurium of peripheral nerves was completely surrounded by carcinoma cells and that marked degeneration and loss of perineural cells occurred. Irregularly thickened basal laminae were detected in the perineurium. For nerves incompletely surrounded by carcinoma tissue, the free portion of the perineurium revealed degenerative findings similar to those for completely surrounded nerves. Cytoplasmic projections of the leading margin of the invading cancer tissue were located in the degenerated perineurium, contained many lysosomes, and were not always surrounded by basal laminae. These observations suggest that invading carcinoma tissue actively contributes to the degeneration of the perineural sheath and that the special pattern of carcinoma tissue surrounding the peripheral nerves results from infiltration along the degenerated sheath of the perineurium.

Aged↗