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Biomedical subjects

H Sakamoto

Publications and source records attributed to H Sakamoto.

At least 703 records · Page 39Linked to original sources
PubMed1989

Calibration of target amounts of DNA in hybridization experiments using monoclonal anti-nucleoside antibodies.

Two anti-nucleoside monoclonal antibodies (A-16 and G-K21) were raised after immunizing mice with adenosine or guanosine coupled to bovine serum albumin by periodate oxidation. They were selected for their ability to detect these immunogens and single-stranded DNA in an enzyme-linked immunosorbent assay test. The antibodies were purified from ascitic fluids, their isotypes were determined and their ability to detect DNAs and RNAs on nitrocellulose membranes was tested. They belonged to the IgG1 subclass and were both able to recognize picogram amounts of single-stranded DNAs on nitrocellulose sheets, whatever the origin of the nucleic acid, but were unable to detect RNA efficiently. The same monoclonal antibodies were used to estimate minute amounts of target staphylococci DNAs to permit standardization of non-radioactive hybridization experiments for detection of antibiotic resistance genes.

Adenosine↗
PubMed1989

Effect of the cap structure on pre-mRNA splicing in Xenopus oocyte nuclei.

The effect of the 5' cap structure on the splicing of precursor mRNAs was investigated after the RNAs were injected into Xenopus oocyte nuclei. The precursor mRNAs synthesized in vitro in a prokaryotic transcription system with a dinucleotide, ApppG, as a primer, were extremely stable when injected into the nuclei yet behaved like uncapped pre-mRNAs in the in vitro splicing reaction. The ApppG-primed precursor mRNAs served as a control (uncapped) in the injection experiments, and their splicing reactions were compared with those of their capped (m7GpppG-primed) counterparts. The capped precursors were spliced more efficiently than the uncapped precursors. Examination of splicing of the precursor mRNA that contained three exons and two introns with a single molecule has revealed that the cap structure exerts its effect primarily on the 5'-proximal intron. Thus, the cap structure not only stabilizes precursor mRNAs but also plays a positive role in the splicing of precursor mRNAs in cells.

Animals↗
PubMed1989

The reactive cellular population and expression of blood group substance in human colorectal cancer.

The correlation between the expression of blood group substance (BGS) and the host's immune response was studied in 23 samples of human colorectal carcinoma tissue. Several monoclonal antibodies against lymphocyte subsets and histiocytes were used for immunostaining of frozen sections, and MoAbs against BGS (A, B, H) for paraffin sections. In proximal colon cancers (10 cases), the cancer tissues showing expression of BGS revealed a greater increase in cells reactive for OKT11, Leu-7, and Leu-M3 than those with deletion of BGS. However, in distal large bowel cancers (13 cases), there was no significant difference between the cancer tissues without BGS expression and those with BGS re-expression. In all locations of the large bowel, cancer tissue showing expression of incompatible antigen revealed a greater reduction of reactive cells than those with expression of compatible antigen. These results suggest that there are disparities in the host's immune response to proximal colon and distal bowel carcinoma, and that factors other than BGS (A, B, H) might influence the immune response in cases with expression of incompatible antigen.

Antibodies, Monoclonal↗
PubMed1989

Effects of non-shunting operation on azygos venous blood flow in cirrhotic patients.

Azygos venous blood flow and other haemodynamic parameters were measured in 14 cirrhotic patients to investigate the effects of a non-shunting operation, oesophageal transection with paraoesophagogastric devascularisation. Azygos venous blood flow measured by the local continuous thermal dilution method was significantly reduced by 13.8% after the operation (428 (41) v 369 (33) ml/min). Hepatic venous pressure gradient (HVPG) was also significantly decreased from 14.5 (0.8) to 12.8 (0.7) mmHg (-11.8%). Cardiac output and routine liver tests did not change remarkably postoperatively. In this haemodynamic study before and after non-shunting operation, moderate but significant decreases were seen in azygos venous blood flow and portal pressure (HVPG), without substantial changes in systemic circulation. This suggests that blood flow through the portosystemic collaterals other than oesophageal varices may be decreased but still adequate after the operation. Well preserved portosystemic collaterals without oesophageal varices are thus considered an optimally balanced state after non-shunting operation.

Adult↗
PubMed1989

Ultrastructure and synaptic architecture of spinal motoneurons in the frog (Rana catesbeiana).

An electron-microscopic analysis of spinal motoneurons and their synapses was carried out in a frog (Rana catesbeiana). Six different types of boutons (S, F, M, P, C and GS) have been identified. Their distribution on spinal motoneuron somata and proximal dendrites is described. The mean linear percentage of the surface area covered by boutons is 26.1 +/- 1.9%. S-type boutons are preferentially concentrated on the soma and proximal dendrites. The relative number of S-type boutons (58.7%) was greater (p less than 0.01) than that of F-type boutons (41.3%). This is in contrast to mammalian spinal motoneurons where F-type boutons are much more numerous on the soma than S-type boutons. F-type boutons are randomly distributed and the average ratio of S:F-type boutons is 20:14 (S:F ratio = 1.4). In contrast, M-type boutons synapse exclusively on the distal part of the dorsal dendrites and are restricted to the intermediate zone or to the dorsal horn. P-type boutons form synapses upon the large M-type boutons. The polarity of these axoaxonic synapses is always from P to M. Similarities and differences between the synaptology of frog and mammalian spinal motoneurons are discussed.

Animals↗
PubMed1989

[Effects of tricyclic antidepressant drugs on receptor binding sites and Ca2+ binding to sarcoplasmic reticulum in rat heart].

The effects of tricyclic antidepressant drugs on cardiac receptor binding sites and Ca2+ binding to cardiac sarcoplasmic reticulum were investigated in rats. 1) Quinupramine was found to possess higher affinity for muscarinic cholinergic receptor binding sites in brain and heart, compared with imipramine. 2) Repeated quinupramine treatment induced a significant increase in the Bmax value in cardiac muscarinic cholinergic receptors. 3) In imipramine treated heart, isoproterenol-induced stimulation of ornithine decarboxylase activity was significantly decreased compared with that in the vehicle control. 4) Repeated quinupramine and imipramine treatment caused a significant reduction of Bmax of 45Ca2+ binding in cardiac sarcoplasmic reticulum fractions. 5) After single quinupramine treatment, its concentrations in heart were higher than those in brain and plasma. 6) After the repeated quinupramine treatment, its concentration in heart was 2.4 times higher than that after single treatment. These results demonstrate that repeated tricyclic antidepressant drug treatment caused a functional impairment in Ca2+ binding sites of cardiac sarcoplasmic reticulum and adaptive changes of receptor binding sites.

Animals↗
PubMed1989

Quantitation of autoantibody-secreting B cells in systemic lupus erythematosus.

An ELISA spot assay was used to quantitate the number of autoantibody-secreting B cells in the peripheral blood of patients with systemic lupus erythematosus. Patients with active disease had 20 fold more anti-DNA, 4 fold more anti-actin and 3 fold more anti-myosin secreting lymphocytes than controls but normal numbers of anti-cardiolipin and anti-transferrin secreting B cells. 60% of SLE patients had increased numbers of B cells reactive with multiple autoantigens. These data suggest that B cell activation in SLE may be influenced by both antigen-specific and antigen-independent factors.

Actins↗
PubMed1989

[Clinical evaluation of PIVKA-II as a marker of hepatocellular carcinoma].

PIVKA-II (protein induced vitamin K absence or antagonist-II) levels in plasma were measured using ELISA in patients with hepatocellular carcinoma (HCC). PIVKA-II was detected in 53 of 97 patients (54.6%) of HCC, and the combination assay of PIVKA-II and AFP identified 69 of 97 patients (71.1%) with HCC. However, the positive rate of PIVKA-II (6.1%) was lower than that of AFP (37.5%) in patients with HCC less than 2 cm in diameter. The concentration of PIVKA-II was markedly reduced within 2 weeks after treatment in patients with HCC showing a favorable response to Lp-TAE or Lp-TAI. Although PIVKA-II is a valuable marker for the diagnosis and follow-up of patients with HCC, it must be noted that the change to negative concentration of PIVKA-II after treatment does not mean complete necrosis of the tumor.

Aged↗
PubMed1989

[Clinical evaluation of clarithromycin in treatment of acute dental infections. Comparative double-blind study using josamycin as the control].

In order to objectively evaluate the usefulness of clarithromycin (TE-031, A-56268), a new oral macrolide antibiotic, in the treatment of acute dental infections, a double-blind comparative clinical trail was conducted using josamycin (JM) as the control drug. TE-031 was administered at a daily dosage of 400 mg in 2 divided doses, and JM was given at a daily dosage of 1,200 mg in 3 divided doses. The administration period was, as a rule, 7 days. A total of 302 patients were administered with the test substances (TE-031 and JM), and the clinical efficacy was evaluated by investigators for 284 patients and by a committee using a score method for 273 patients. Efficacy rates as evaluated by the investigators were 77.2% (105/136) in the TE-031 group and 69.6% (103/148) in the JM group. Efficacy rates as evaluated by the committee by the score method were 86.0% (111/129) in the TE-031 group and 80.6% (116/144) in the JM group. The differences between the 2 drug groups were not statistically significant. The investigators' evaluation of the clinical efficacy in the treatment of osteitis of the jaw gave an efficacy rate of 83.0% (44/53) in the TE-031 group and 64.7% (33/51) in the JM group. The efficacy rate in the TE-031 group was statistically higher than that in the JM group. Side effects were recorded in 7 patients (4.8%) in the TE-031 group and 3 patients (2.0%) in the JM group, while abnormal laboratory test values were detected in 3 cases each in the TE-031 and JM groups. None of these differences were statistically significant. The usefulness rates ("satisfactory" plus "very satisfactory" cases) were 73.9% in the TE-031 group and 70.3% in the JM group and were thus almost the same for the 2 drug groups. On the basis of the above results, TE-031 was concluded to be a useful drug in the treatment of acute dental infections and is expected to be able to achieve almost identical clinical efficacy as JM at only one-third of the usual dosage of JM.

Acute Disease↗
PubMed1989

[Anatomical study of the ramification and intramuscular distribution of the intercostal nerves in man].

Minute dissection was performed on the ventral primary rami of the thoracic and the first lumbar nerves in the left half of an adult male cadaver in order to obtain more detailed data of the nerve supply to the muscles of the thorax and abdomen. The ribs, costal cartilages, sternum and vertebral column were removed to facilitate dissection. The origin, course and intramuscular distribution of the muscular branches of each nerve were examined in precise detail. The main findings are as follows: 1. The intercostal nerves The collateral branches were found in approximately 1/3 of the segments examined. Each branch rejoined the main trunk close to point in which the lateral cutaneous branch pierces through the intercostal muscles. Each lateral cutaneous branch arose from the main trunk proximal to the midaxillary line. The branch had some communications with the main trunk, and occasionally received a twig from the collateral branch. 2. The muscular branches 1) In general, the nerves to each intercostalis externus arose from the main trunk proximal to the costal angle. Additional slender twigs were occasionally found arising from the lateral cutaneous branch and joining the main supply nerve. 2) For the convenience of description of the nerve supply to the intercostalis interni et intimi, each intercostal nerve is divided into three parts from proximal to distal: part 1, the outside of the intercostalis intimus; part 2, between the intercostalis intimus and intercostalis internus; and part 3, inside the intercostalis internus. Branches to the intercostalis intimus arose in part 1, predominantly from the initial portion of the main trunk, either independently or with the branches of the intercostalis externus. In part 2, the branches generally originated as a common trunk with the branches of the intercostalis internus. 3) Branches to each subcostalis arose from the initial portion of the intercostal nerve belonging to the same intercostal space as the upper half of the muscle. The branches originated either independently or formed a common trunk with the branch to the intercostalis externus. 4) Branches to the transversus thoracis arose relatively independently from the third to sixth intercostal nerves. These branches ran inside of the nerves to the intercostalis internus and the common trunks of the intercostales internus and intimus branches, and entered the muscle from the anterior side. Each digit of the muscle was innervated by a nerve from the intercostal nerve corresponding to that costal attachment. The lower digit had an additional branch from the nerve of the upper adjoining space.(ABSTRACT TRUNCATED AT 400 WORDS)

Abdominal Muscles↗
PubMed1989

Biological significance of the hst-1 gene.

hst-1, or HSTF1 in human gene nomenclature, was originally identified as a transforming gene in DNA samples from human stomach cancer by NIH3T3 transfection assay. Many reports have followed to show the presence of a transforming hst-1 gene in various types of cancerous and noncancerous tissues, suggesting that the hst-1 gene is the most common non-ras transforming gene. We cloned the hst-1 genomic fragments from DNAs of a normal individual and a patient with leukemia and also from NIH3T3 cells themselves. All of these clones transformed NIH3T3 cells upon transfection. Sequence analysis of the cDNA and genomic hst-1 led us to conclude that the normal hst-1 protein transforms NIH3T3 cells when its expression is deregulated. The hst-1 protein has 40-50% homology to basic and acidic fibroblast growth factors (FGFs) and to the int-2 protein. The purified hst-1 protein synthesized in a baculovirus system was a potent heparin-binding growth factor for a variety of cells, including human endothelial cells. The hst-1 protein, when it was added to the culture medium, induced morphological transformation of NIH3T3 cells and anchorage-independent growth of NRK cells. The hst-1 gene is located 35 kbp downstream of one of its homologous genes, int-2, on human chromosome 11 at band q13.3. As in the case with the int-2 gene, the hst-1 transcripts were not detected in adult mice but found in mouse embryos. A relatively large amount of the hst-1 message was present in a mouse teratocarcinoma cell line, F9, while the int-2 mRNA was barely detected. Upon induction of differentiation in vitro, the hst-1 transcription was depressed to almost nil, and the int-2 message increased dramatically. The hst-1 and int-2 genes were coamplified in a variety of cancer cells, most notably in more than 50% of esophageal cancers.

Animals↗
PubMed1989

[A case of summer type hypersensitivity pneumonitis resulting in chronic respiratory failure and cor pulmonale].

A female case of Japanese summer-type hypersensitivity pneumonitis who was a smoker developed in chronic respiratory failure several years later. Biopsy specimen on first admission showed findings of granulomatous bronchioloalveolitis distributed in the center of secondary lobules. Pulmonary function studies demonstrated restrictive disease with high RV% and low airway conductance. In spite of steroid therapy, dyspnea persisted and the same symptoms were found on next summer. Six years later symptoms of chronic respiratory failure and cor pulmonale developed. Chest X-Ray showed dilated pulmonary artery, cardiomegaly and overinflation without apparent fibrosis. Hypoxemia and hypercapnia were also seen on blood gas analysis. Pulmonary function was unchanged compared to the findings on first admission. Since then long term oxygen therapy was started. It was thought that irreversible small airway disease caused by hypersensitivity pneumonitis was attributable to cor pulmonale and chronic respiratory failure because of her smoking habit and long period of exposure to antigen. As a patient with summer type hypersensitivity pneumonitis always has a possibility of chronic disease developing after long term exposure to antigen, such as a farmer's lung, the cessation of exposure to antigen by complete cleaning up of the patient's environment or moving out were considered to be important.

Alveolitis, Extrinsic Allergic↗