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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 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↗
PubMed1985

Specificity of the interaction between lambda cro repressor protein and operator DNA fragments.

Cro repressor protein is known to interact with specific sites in the operator DNA. The cro protein of lambda phage was isolated and the mode of its interaction with three different DNA fragment, lambda-OR3 17mer, phi 80-OR2 19mer and CAP binding site 22-mer, were examined by the use of proton NMR. Some of the imino proton resonances of lambda-OR3 shifted and were broadened remarkably on addition of lambda-cro protein, which indicated the induction of conformational change with complexation. In the spectrum of phi 80-OR2 which has a six base pair sequence common to lambda-OR3 the signals of the common base pairs revealed slight shifts on addition of lambda-cro protein. The imino proton signals of the CAP site DNA, however, did not show any change at all on mixing with lambda-cro. Combining the data of photo CIDNP of lambda-cro, we could postulate the mode of interaction between lambda-cro repressor and operator DNA.

Bacteriophage lambda↗
PubMed1985

Modified Blalock-Taussig shunt following long-term administration of prostaglandin E1 for ductus-dependent neonates with cyanotic congenital heart disease.

In the treatment of cyanotic heart diseases in neonates who are ductus dependent, the small size of the pulmonary artery and/or subclavian artery often precludes construction of a sufficient Blalock-Taussig shunt. To avoid an emergency operation and to obtain pulmonary and subclavian arteries of adequate size (3 mm), a low dose of prostaglandin E1 was given to 16 neonates for a mean of 47 days (range 26 to 65 days), and a modified Blalock-Taussig shunt operation was performed in neonates whose mean age was 50 days. The pulmonary artery grew significantly (mean 4.5 mm) and the mean diameter of the subclavian artery was 3 mm, which was large enough for a good shunt at the time of operation. There were two late deaths and one operative death. All surviving patients shunts at the mean follow-up period of 22 months. The shunt was constructed on the same side as the ductus arteriosus so that the ductus could be ligated at the same operation in selected cases; the ductus may not close after discontinuation of prostaglandin E1 infusion and may cause uncontrollable congestive heart failure because of excessive pulmonary blood flow, particularly in patients with a univentricular heart. The ductus, dissected in nine patients, was enlarged and elongated in all and was ligated in four patients without complication.

Ductus Arteriosus, Patent↗