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Biomedical subjects

A Wada

Publications and source records attributed to A Wada.

At least 505 records · Page 28Linked to original sources
PubMed1979

Stability mapping along the DNA double strand and its relation to the genetic map.

The distribution of the stability of the double helical structure along the whole DNA of fdphage and its restriction fragments is calculated. In this calculation, Poland's method, which has been established as a rigorous algorithm for taking the base sequence explicitly into consideration, is used. The molecular thermodynamic parameters in the calculation have been determined so as to best reproduce the melting profile of the DNA and its fragments. The results, which are presented as melting maps, show fairly good agreement with those experimentally obtained by the present authors earlier. A close correlation with genes in the genetic map is apparent for some cooperatively melting regions observed in the stability map.

Chemical Phenomena↗
PubMed1978

Location of the cooperative melting regions in bacteriophage fd DNA.

Differential melting profiles of the linear replicative form (RF-III) DNA of bacteriophage fd, of the fragments obtained by the restriction endonuclease R.HinHI and of those obtained by R.Hga were investigated. With these results a physical map which locates the cooperative melting regions on the DNA was constructed, and compared with the genetic map.

Base Sequence↗
PubMed1978

Production of several substances by medullary carcinoma of the thyroid.

Two patients with the typical morphology of medullary carcinoma of the thyroid are reported. Biochemical analysis of the tumor tissue demonstrated the presence of calcitonin, ACTH and MSH, although symptoms referable to these hormones were hardly manifested. Serum CEA levels were elevated and CEA immunofluorescences in the tumor cells were positive. Moreover, in one patient, serotonin concentration was raised in the tumor tissue, and gastrin level was also elevated in the peripheral blood. These results suggest that the tumors may produce several substances.

Adult↗
PubMed1978

A cytologic study on small cell carcinoma of the esophagus.

The cytologic picture of small cell carcinoma primarily arising from the esophagus was studied with 7 cases which were confirmed by histologic examination. Cytomorphologic characteristics of small cell carcinoma of the esophagus are as follows: the arrangement of groups of tumor cells is irregular and overlapping with indistinct cell boundaries. The cytoplasm is small, or sometimes absent. The nuclei are round, oval or occasionally spindle shaped. Nuclear borders are thin. The chromatin of finely granular pattern has increased and is evenly distributed.

Aged↗
PubMed1978

Coexistence of bilateral pheochromocytoma and pancreatic islet cell tumor: report of a case and review of the literature.

A 14-year-old Japanese male with a previously undescribed combination of bilateral pheochromocytoma and an islet cell tumor of the pancreas is presented. The combination of endocrine neoplasms in this patient overlaps multiple endocrine neoplasia (MEN) Type 1 and Type 2. A total of 14 reported cases of MEN overlapping Type 1 and Type 2 is reviewed. Of the 14, 7 patients with acromegaly developed a paraganglioma(s), 2 patients with Sipple syndrome had a pituitary adenoma, and in the other 5 patients, an intestinal carcinoid or a pancreatic islet-cell tumor occurred in association with either a thyroid medullary carcinoma or a paraganglioma(s). We believe that the occurrence of MEN overlapping Type 1 and Type 2 is more than a fortuitous association, and can be explained on the basis of the neuroectodermal origin.

Adenoma, Islet Cell↗
PubMed1978

Mechanisms of late recurrence after radical surgery for gastric carcinoma.

Factors involved in late recurrence of gastric carcinoma were investigated in 25 patients with late recurrence who died five or more years after radical surgery and 129 with early recurrence who died within two years after surgery. In the patients with late recurrence, the important routes of cancer spread in the initial phase of the recurrence were contiguous invasion and lymphatic spread. Whether early or late recurrence occurred had a high correlation with the following four conditions: (1) the amount of residual cancer left at the time of surgery; (2) the spread of the residual cancer; (3) the rate of cancer proliferation; and (4) the resistance of the host. To prevent late recurrence, it is necessary not to leave any cancer tissue in these routes at the time of gastrectomy, as well as to employ adjuvant chemo- and immunotherapy for the inhibition of cancer proliferation and elevation of the host resistance.

Humans↗
PubMed1978

"Thermal stability" maps for several double-stranded DNA fragments of known sequence.

The origin of cooperatively melting regions in DNA, which appear as fine structures in the optical melting profile, has been examined for DNA fragments of known base sequences from bacteriophages phiX174 and fd. Thermal stability maps, which indicate the states of base pairs along these DNA strands, were constructed within the established theoretical framework using the parameters which best reproduce the melting profiles obtained by high temperature resolution experiments. By comparing these stability maps with genetic maps, it was found that several cooperatively melting regions which span several hundred bases have some correlation with the gene locations.

Base Sequence↗
PubMed1978

Base and base sequence specificity of the binding of 4-hydroxyaminoquinoline 1-oxide to DNA.

Synthetic and natural DNAs we;e reacted with 4-hydroxyaminoquinoline 1-oxide (4-HAQO) in an in vitro enzyme system. The amount of 4-HAQO bound to DNA varied significantly depending on the DNA used. The base sequence as well as the base composition affected the binding. Optical melting profiles of 4-HAQO-modified DNAs were examined. Decrease in the melting temperature and broadening of the transition width were commonly observed. Melting fine structure of lambda-phage DNA became less clear according to the modification. The shape of the melting curves of synthetic polynucleotides was little affected by binding, which suggests that the binding sites are distributed randomly along a DNA molecule. Binding of 4-HAQO to a purine base may distort the secondary structure of neighboring base pairs in a DNA molecule. Degree of the distortion can be estimated as a free energy increment associated with the binding. It was found that the free energy increment differs considerably among the polynucleotides with different base sequences.

4-Hydroxyaminoquinoline-1-oxide↗
PubMed1978

Inhibition by trichlormethiazide of catecholamine release from perfused bovine adrenals.

Effect of thiazides on catecholamine release was examined using perfused bovine adrenal glands in vitro. Thiazides, such as trichlormethiazide and methyclothiazide inhibited catecholamine release evoked by carbamylcholine although they did not inhibit catecholamine release evoked by excess potassium. Thus it seems that these drugs inhibit catecholamine release release by an anticholinergic mechanism. Such inhibitory effect of thiazide on catecholamine release may be involved in the antihypertensive effect of these drugs.

Adrenal Glands↗
PubMed1978

Studies on the use of mumps virus for treatment of human cancer.

Purified mumps virus (Urabe strain) was given mainly by intravenous injection to a total of 200 patients with cancer. The only adverse clinical reaction was transient mild fever in about half the patients. The beneficial clinical effects were as follows; decrease or disappearance of ascites and edema of the lower limbs at high rates (26/37 and 4/4, respectively), usually within a week after treatment: decrease or stoppage of cancerous bleeding in 30 of 35 patients: decrease or disappearance of pain in most of the patients: and tumor regression in 26 patients with cancer of the breast, rectum, ileocaecum, thyroid gland, uterus, skin, etc. Histologically, the virus-treatment caused shrinkage of nuclei and vacuolization of the cytoplasma of tumor cells, but the degenerative changes of tumor cells were not so great as those after chemotherapy or radiotherapy. Infiltration of lymphocytes, fibrosis and collagenesis occurred around tumor tissues, where necrosis or exfoliation of tumor cells was frequently observed.

Adenocarcinoma↗