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Biomedical subjects

T Andoh

Publications and source records attributed to T Andoh.

At least 217 records · Page 12Linked to original sources
PubMed1989

[Thallium-201 imaging of brain tumors using single photon emission CT].

Single photon emission CT using thallium-201 chloride, injected intravenously, was performed on 28 cases of cerebral lesions, among which were 16 gliomas, 2 meningiomas, 5 other brain tumors, 3 metastatic brain tumors and 2 cerebral radiation necroses. The degree of thallium-201 accumulation was evaluated by a new method called the thallium index (TLI); that is, TLI was expressed as (T-C)/C (T and C indicate relative counts in a pixel of a lesion and in non-affected normal brain tissue, respectively). Thallium-201 accumulation occurred in 86% (24) of the evaluated cases. In general, there was a tendency in high-grade or recurrent gliomas, as well as in metastatic brain tumors for the TLI values to be high. Moreover, high TLI values were noticed in cases of meningioma, radiation necrosis of cerebellum and in cases involving subacute stages of cerebral infarction. It is particularly noteworthy that the meningioma TLI values were about two times higher than those of the glioblastomas. The CT contrast-enhancement of lesions was clearly correlated with the TLI values, and the relationship between the TLI values and the number of vessels observed microscopically in the specimen was statistically significant. From the above results, it was concluded that thallium-201 accumulation in lesions might be strongly influenced by the development of vascularity in lesions, and/or the interference with the blood brain barrier due to the tumor itself. However, this malignancy diagnostic method is probably limited to the diagnosis of glioma.

Adult↗
PubMed1989

[Ultrasonography-guided cobalt-60 brachytherapy of malignant glioma].

Brachytherapy with cobalt-60 source is reported. In this method it is characterized that the source is inserted interstitially with remote control system by after-loading method via outer catheter (using tandem tube), which was established in the center of residual tumor, using ultrasonography guide with trepanation, or intraoperatively put within the dead space after tumor resection. Six cases of deep-seated and recurrent malignant glioma, were treated with this method. A total dose of 20 to 45 Gy (10 to 15 Gy/day for 2 to 3 days) was delivered to the target. Additionally conventional external irradiation was followed. The effect of cobalt-60 brachytherapy on such tumors were favorable especially for well-circumscribed glioma less than 3 cm on CT scan.

Adolescent↗
PubMed1989

[Clinical study on intracranial arachnoid cyst: with reference to the middle cranial fossa].

Thirty-two cases of congenital arachnoid cyst (AC), 26 cases of supratentorial, and 6 cases of infratentorial cyst are reported. They were encountered over a period of 9 years. The 26 supratentorial cysts consisted of 21 cases located in the middle fossa, 2 in the frontal, and 3 in the suprasellar. Patients' ages ranged from 7 months to 67 years (mean: 19.3 years), with a male to female ratio of 23:9. The most common symptoms were headache, epileptic seizure, and cranial enlargement. Based on observations between neuroradiological examinations including analysis of the cyst content, and operation, typical AC might be defined as "duplicated arachnoid and its splitting", and it may be said that "there is continuous existence of cerebral structure such as cortex and white matter lying adjacent to AC on MRI". Out of 32 cases, 15 received surgical treatment because of mass effect of AC itself, abnormal dynamics of the AC fluid, and/or increasing sign of ICP. 13 cases had resection of AC outer membrane with craniotomy, and the remaining two had cystoperitoneal shunt. One of the shunting cases complicated subdural hematoma. Surgical treatment was discussed and radical craniotomy rather than a shunt procedure was preferred. Prognosis of all cases was favorable and uneventful.

Adolescent↗
PubMed1989

[Changes in serum pancreatic secretory trypsin inhibitor (PSTI) during and after heart surgery].

Serum pancreatic secretory trypsin inhibitor (PSTI) is considered to be one of the acute phase reactants which increase after tissue injuries like surgery or major trauma. 25 patients were studied to investigate the changes in serum PSTI during and after heart surgery. 18 patients underwent the operation with the aid of cardiopulmonary bypass (CPB)-CPB group, and the other 7 patients, all pediatric cases, were treated under simple deep hypothermia by surface cooling without CPB-simple hypothermia group. Serum amylase, serum C reactive protein (CRP), cardiac index and A-aDO2 after surgery were examined, and the duration of CPB or circulatory arrest were recorded. The correlation between serum level of PSTI after surgery and these parameters were also studied. During surgery, a transient elevation of serum PSTI was noticed in the period of CPB, but no significant change of serum PSTI was seen under simple deep hypothermia and circulatory arrest. On the first post operative day, a slight but significant increase of serum PSTI was seen in CPB group, on the other hand no significant increase was seen in simple hypothermia group. Postoperative increase of serum PSTI was correlated to circulatory arrest time in simple hypothermia group, and was inversely correlated to cardiac index determined immediately after the operation in CPB group. No correlation was seen between serum level of PSTI after surgery and serum amylase, CRP, A-aDO2 or duration of CPB. The magnitude of increase of serum PSTI after heart surgery was small, and did not seem to be well correlated to the extent of surgical insults.

Adult↗
PubMed1989

[Power spectral analysis of EEG during simple deep hypothermia under ether anesthesia].

Power spectral analysis of electroencephalogram was performed during simple deep hypothermia under ether anesthesia, compared with that during hypothermic cardiopulmonary bypass under morphine anesthesia. In ether anesthesia group, EEG isoelectricity developed at average esophageal temperature of 27.2 degrees C which is higher than the temperature previously reported. This remarkable depression of the EEG may be due to deep ether anesthesia, because severe hypotension episodes were not associated with this and no neurological complication was noticed post-operatively. In cardiopulmonary bypass group, EEG activity persisted throughout the procedures even at the lowest esophageal temperature reached of 22.3 degrees C. In ether anesthesia group, the temperature at which EEG activity reappeared correlated with the duration of circulatory arrest. During simple deep hypothermia under ether anesthesia, the EEG is not useful to detect brain ischemia during cooling period, because EEG activity was lost in the early course of cooling, but during rewarming period the EEG demonstrated depression of cerebral function due to total circulatory arrest.

Anesthesia↗
PubMed1988

Characterization of a camptothecin-resistant human DNA topoisomerase I.

Topoisomerase I purified from a camptothecin-resistant human leukemia cell line and from the parental, camptothecin-sensitive line were compared in vitro. Relaxation of supercoiled DNA by the wild type enzyme was inhibited in the presence of camptothecin, while the mutant enzyme was unimpaired. Camptothecin altered the cleavage pattern of the wild type but not of the mutant enzyme. The stability of cleavable complexes was studied at a preferred topoisomerase I-binding sequence recognized by both enzymes. Camptothecin greatly enhanced the kinetic stability of the cleavable complex formed by the wild type enzyme, whereas that of the mutant enzyme was only marginally affected. In the absence of camptothecin, the cleavable complex formed by the mutant enzyme was stabilized relative to that of the wild type by several criteria. Thus, the mutant enzyme cleaved the topoisomerase I recognition sequence with 2-fold higher efficiency than the wild type enzyme. The mutant cleavable complex had a higher kinetic stability and was less sensitive to salt dissociation than the wild type complex. Furthermore, the mutant enzyme formed cleavable complexes in the absence of divalent cations, which were required for complex formation by the wild type enzyme.

Base Sequence↗
PubMed1988

Fate and distribution of an antitumor protein-bound polysaccharide PSK (Krestin).

The fate of 14C-labelled PSK in the body was investigated. Although only substances with low mol. wt were observed in blood shortly after the administration, with time, substances with high mol. wt appeared, suggesting absorption of PSK in its original form from the digestive tract. 14C-labelled PSK was distributed in bone marrow, salivary gland, brain liver, spleen, pancreas and tumor. Approximately 70% of 14C-labelled PSK was excreted by expiratory air after 24 h and approximately 15-20% in urine after 72 h. Only a small amount of 14C-labelled PSK was transferred into lymph and bile. The present study on the in vivo behavior of PSK provides an important basis for further analysis of its pharmacological actions.

Absorption↗
PubMed1988

Primary structure of two mRNAs encoding putative salmon alpha-subunits of pituitary glycoprotein hormone.

1. By random sequence analyses, we isolated from the cDNA library of salmon pituitary glands two clones, the deduced amino acid sequences corresponding to the C-terminal region of which are almost the same as those of the alpha subunits of mammalian glycoprotein hormones. 2. Comparison of the nucleotide sequences and deduced amino acid sequences from these two clones with those of mammalian species revealed that the two newly-isolated cDNAs corresponded to mRNAs encoding the putative salmon pre-alpha subunit of glycoprotein hormones. 3. Homology in the nucleotide sequences of these two clones suggested that corresponding mRNAs may be encoded by separate genes which probably evolved from a common ancestral gene.

Amino Acid Sequence↗
PubMed1988

Absence of a gamma-melanocyte-stimulating hormone sequence in proopiomelanocortin mRNA of chum salmon Oncorhynchus keta.

1. Complete nucleotide sequence of one of the salmon proopiomelanocortin mRNAs (POMC mRNAs) was determined. 2. The region corresponding to gamma-melanocyte-stimulating hormone (gamma-MSH) was lacking in salmon POMC mRNA, although overall organization of the multi-hormone structure was exactly the same as that of mammalian POMC mRNAs. 3. The possible evolutional history of POMC mRNA in mammalian species may be revealed from the finding of this characteristic that salmon POMC mRNA lacks the region corresponding to gamma-MSH.

Amino Acid Sequence↗
PubMed1988

Primary intracranial germ-cell tumors. A retrospective analysis with special reference to long-term results of treatment and the behavior of rare types of tumors.

Thirty cases of primary intracranial germ-cell tumors were reviewed with reference to the effect of treatment. Histologically, there were 23 pure germinomas, while the remaining tumors had more unusual histology; 3 of these were teratomas, and 4 germ-cell tumors with the admixture of yolk sac tumor (YST) or embryonal carcinoma (EMC). Three of these rare cases are presented. The performed surgery and radiotherapy, seemed adequate for pure germinomas, and all these cases lived tumor-free after an observation time of 13 to 139 months although 4 patients developed intellectual retardation or cerebral dullness after radiotherapy. Four cases with YST and EMC elements, indicated by the elevation of AFP and HCG values in serum, were resistant to radio- and chemotherapy and developed, despite surgically total removal of the tumor, intra- or extracranial metastases. A review of the literature is included.

Adolescent↗
PubMed1988

[Biological function of DNA topoisomerases and its implication in cancer chemotherapy].

It has been generally recognized that in a variety of biological systems the structural changes such as circularization, looping and supercoiling of DNA play important roles in carrying out genetic processes such as replication, transcription, recombination etc. Since the discovery of DNA topoisomerase I in 1971 (then named omega protein) in E. coli type I and type II topoisomerases have been found in a wide variety of organisms. In addition the finding that these enzymes are the only ones which can cope with the torsional strain accumulating within the DNA molecules carrying out the genetic processes by swiveling the strands through breakage and rejoining of phosphodiester bonds strongly suggests that they are involved in various aspects of DNA metabolism such as replication, transcription, recombination, differentiation etc. In this article the function of DNA topoisomerases elucidated so far in prokaryotic and eukaryotic cells with special emphasis on their roles in gene expression has been briefly reviewed.

Antineoplastic Agents↗
PubMed1988

[Nutritional condition and absorptive capacity of 14 infants with short bowel syndrome].

We examined the absorptive capacity and the nutritional condition of 14 infants with short bowel syndrome, whose residual small intestine was 90 cm or less. Their age ranged from 1 year to 18 years. Examined items were body weight, height, serum albumin, total cholesterol, triglyceride, fat soluble vitamins, trace elements and rapid turn over protein as markers of the nutritional condition. Fecal fat, fecal bile acid, d-xylose absorption test, sugar-, amino acid-evoked potential difference in the small intestine and disaccharidase activity of the mucosa were examined as markers of the absorptive capacity. Our results showed that the body weight was below the normal range in the patients with small intestine of less than 50 cm. Most nutritional markers were within normal range, however, cholesterol and vitamin D were low in the patients with fat malabsorption, especially in patients with less than 50 cm of small intestine. Fecal bile acid was higher than the normal range in all the patients. Potential difference was in normal range or slightly lower than normal in all the patients. We concluded that infants with less than 50 cm of small intestine had malabsorption of sugar, protein and fat. Therefore, prolonged nutrient support, especially fat, is necessary.

Adolescent↗
PubMed1987

Mechanism of inhibition of mammalian DNA topoisomerase I by heparin.

We have previously shown that heparin is a potent inhibitor of a mammalian DNA topoisomerase I. We have now investigated the mechanism of its inhibition. This was carried out first by scrutinizing the structural features of heparin molecules responsible for the inhibition. Commercial heparin preparation was fractionated by antithrombin III-Sepharose into non-adsorbed, low-affinity and high-affinity fractions, of which only the high-affinity fraction of heparin is known to contain a specific oligosaccharide sequence responsible for the binding to antithrombin III. These fractions all exhibited essentially similar inhibitory activities. Furthermore, when chemically sulphated to an extent comparable with or higher than heparin, otherwise inactive glycosaminoglycans such as heparan sulphate, chondroitin 4-sulphate, dermatan sulphate and neutral polysaccharides such as dextran and amylose were converted into potent inhibitors. Sulphated dermatan sulphate, one of the model compounds, was further shown to bind competitively to the same sites on the enzyme as heparin. These observations strongly suggested that topoisomerase inhibition by heparin is attributable primarily, if not entirely, to the highly sulphated polyanionic nature of the molecules. In a second series of experiments we examined whether heparin inhibits only one or both of the topoisomerase reactions, i.e. nicking and re-joining. It was demonstrated that both reactions were inhibited by heparin, but the nicking reaction was more severely affected than was the re-joining reaction.

Antithrombin III↗