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Biomedical subjects

S Maki

Publications and source records attributed to S Maki.

At least 145 records · Page 8Linked to original sources
PubMed1985

Histological studies of electrically induced intramedullary callus.

The author studied the early changes of electrically stimulated bone marrow and carried out histological examinations. A constant current of 10 microAmp was delivered to the cathode which was placed in the humerus of each rabbit. On the 5th, 14th and 21 st day, the rabbits were killed, and the intramedullary tissues around the tip of the cathode were processed for light and electron microscopic observations. In the early stages after electrical stimulation, the leakage of erythrocytes, membranocystic degeneration of lipid cells, and proliferation of undifferentiated mesenchymal cells with moderately developed rER and collagen bundles were recognized. These findings indicate that the oxygen tension around the cathode was diminished in advance of the electrically stimulated callus formation. After prolonged electrical stimulation, both membranous and endochondral ossifications were more active than those in the control group.

Animals↗
PubMed1984

Selective targeting of anti-cancer drug and simultaneous image enhancement in solid tumors by arterially administered lipid contrast medium.

Twenty-four patients with various solid tumors including metastatic liver cancer and cancer of the lung, gallbladder, and pancreas were treated with a lipophilic macromolecular drug, copoly(styrene-maleic acid) conjugated neocarzinostatin (SMANCS). The drug was dissolved in a lipid contrast medium Lipiodol and administered by catheterizing the respective feeding arteries under x-ray monitoring. The advantages of this therapy include: (1) selective deposition of Lipiodol with the anti-cancer drug in the target tumor, (2) a pronounced and long-lasting anti-cancer effect, (3) enhanced visualization of the tumor on x-ray examinations for a prolonged period which also facilitated the long-term follow-up, (4) semiquantitative evaluation of the dosage regimen by x-ray examination before further administration, (5) general applicability due to procedural simplicity, and (6) little side effect. Since the amount of Lipiodol and SMANCS used per administration for a patient (1.0-5.0 ml; 1.0-5.0 mg) was far less than the anticipated toxicity (LD50 of Lipiodol = 95 ml/60 kg, dog, intravenously; and that of SMANCS = 3.4 mg/kg, mouse, IV), no deleterious effects to such critical organs as the brain, heart, lung, liver, or kidneys were observed upon radiologic and general clinical examination.

Adenocarcinoma↗
PubMed1984

DNA sequence of an amber replication mutant indicates that a 29 kd protein is the product of the F plasmid replication gene.

DNA sequencing shows that the mutational alteration resulting from an amber-suppressible replication-defective mutation of F plasmid is a single base pair change from C:G to T:A which yields an amber codon in the coding frame for a 29 kd polypeptide located in the minimal replication region. We thus identified the gene indispensable for F DNA replication as the coding frame which encodes a 29 kd polypeptide. We will designate this gene repA.

Base Sequence↗
PubMed1984

[Arterial administration of SMANCS and other antitumor agents dissolved in lipiodol for various malignant solid tumors].

Selective deposition of lipiodol in primary and metastatic liver cancer, lung cancer, gallbladder cancer, pancreatic cancer and renal cancer was elucidated by plain X-ray film and CT. Selective delivery of anticancer agent, SMANCS was also proved by measurement of its biological activities of removed specimen. Because of these selective delivery of anticancer agent and embolization of neovasculature in the tumor, highly effective chemotherapy of unresectable cancer was established. Drug was given via celiac, the hepatic, bronchial or renal artery mostly 1-5 mg in 1-5 ml of lipiodol once every 3-8 weeks. Antitumor effects of this therapy for hepatocellular carcinoma was confirmed based on decrease in AFP levels (92% of the cases), reduction in tumor size (90% of the cases) and histology. In 76 percent of the patients with the other malignant solid tumors reduction in tumor size was recognized. Decrease in CEA level occurred in 88 percent of the cases with metastatic liver cancer and lung cancer. Major side effect was transient fever in about 50% of cases. Mitomycin C and aclarubicin dissolved in lipiodol showed remarkable antitumor effects for experimental liver cancer.

Aclarubicin↗
PubMed1984

[Tumor selective drug delivery with lipid contrast medium (smancs/lipiodol): sustained antitumor effect, enhanced diagnostic value and quantification of dosage regimen].

A new method for the treatment of solid tumor, in particular, primary and metastatic liver cancer using a hydrophobic-polymer conjugated macromolecular anticancer agent, smancs is described. Smancs was dissolving in a lipid contrast medium, Lipiodol, as an injection into the feeding artery. The marked antitumor effect was observed in both experimental animals and human trials. In the patients with hepatocellular carcinoma, both reductions in tumor size and alpha-feto-protein were observed in 91% of the patients. The survival period of the treated patient with highly advanced stage and inoperable cases was comparable to or better than that of resected cases. No major side effect such as bone marrow suppression or liver toxicity was observed due to selective drug delivery to the tumor. About half of the patients, however, showed a transitory fever (37-39 degrees C) for 1-3 days. The mechanism for such selective tumor targeting of anticancer agent appears to be due to the difference in the vascularity of tumor and normal tissue. Furthermore, we found that lack of lymphatic clearance system in the tumor made the prolonged and selective retention of such lipophilic drug in the tumor tissue possible. Another advantages of this method are found in radiological approaches. Differential diagnosis of primary or metastatic cancer became possible and dosing regimen can be determined since a presence of the contrast medium is restricted to the tumor area and it parallels to that of the drug being dissolved. Insufficiency in X-ray staining indicates a need for subsequent injection. The selective remaining of Lipiodol in the tumor for long period may help follow-up study as well.

Animals↗
PubMed1983

An amber replication mutant of F plasmid mapped in the minimal replication region.

We have constructed a mini-F derivative (pKP1013) consisting of a 5.4 kilobase pairs (kb) segment (44.0 to 49.4 kb) of mini-F and fragments carrying the chloramphenicol and spectinomycin resistance genes that originated from the R plasmid NR1. The plasmid pKP1013 replicates autonomously in a manner indistinguishable from that of the parental mini-F. An amber mutant defective in replication has been isolated from pKP1013 by localized mutagenesis using N-methyl-N'-nitro-N-nitrosoguanidine. The virtual absence of incorporation of [3H]-thymidine into the plasmid DNA as well as the kinetics of appearance of plasmid-free segregants suggest that plasmid DNA synthesis is primarily affected under nonpermissive conditions. The amber mutation has been mapped within the 530 base pairs (bp) region that extends from 45.25 (XmaI) to 45.78 Kb (PstI) by extensive analysis of in vitro recombinants constructed from rep+ and rep- plasmids.

Chromosome Mapping↗
PubMed1983

Lesions of the mediodorsal thalamic nucleus do not change thresholds for hypothalamic defensive attack in cats.

Electrolytic lesions of the mediodorsal thalamic nucleus (nMD) were made in 10 cats to evaluate their effects on thresholds for hypothalamic defensive attack and emotional reactivity to noxious stimuli. Only 2 cats showed minimal threshold changes after the lesions, one of which was accompanied by an increased emotional reactivity to noxious stimuli; however, this was attributed to damage to the fornical column. The nMD appeared not to be involved directly in the central mechanism of defensive attack.

Animals↗
PubMed1983

Effect of arterial administration of high-molecular-weight anticancer agent SMANCS with lipid lymphographic agent on hepatoma: a preliminary report.

A clinical evaluation of arterial infusion of high-molecular-weight antitumor agent SMANCS dissolved in lipid lymphographic agent (thiodol) in 44 patients with mostly unresectable hepatoma is described. The treatment regimen demonstrated significant merits both therapeutically and diagnostically. Marked antitumor effects were shown in the decreased serum alpha-fetoprotein levels (86% of cases) and tumor size (95% of cases), and in survival period and histological findings. Furthermore, there was increased diagnostic sensitivity using CT scan, plain X-rays or ultrasound. The procedure of selective arterial administration of 3-4 mg of SMANCS in 3-4 ml of ethiodol per dose was simple to perform and was required only once every 3-4 weeks. Both ethiodol and the drug accumulated more selectively in tumor than in any other tissues and their activity remained for more than 3 weeks. Only minimal side-effects were associated with SMANCS and ethiodol during this study.

Adult↗
PubMed1982

Cloning of colicin E1 tolerant tolC (mtcB) gene of Escherichia coli K12 and identification of its gene product.

A mutation in the tolC(mtcB) gene of Escherichia coli K12 results in increased sensitivity to sodium dodecylsulfate (SDS), sodium deoxycholate, basic dyes, mitomycin C, and bleomycin, and makes the cell tolerant to the killing action of colicin E1. From lysogens with lambda cI857S7 integrated at a secondary attachment site, a transducing phage (lambda dtolC+) that transduces a tolC recipient to SDS resistance was isolated. A recombinant DNA molecule was constructed in vitro from plasmid pBR322 as a vector, and an EcoRI-BamHI fragment of lambda tolC+ DNA. The resulting plasmid, designated pOK1, was 5.6 megadaltons (Md). The tolC bacteria transformed with plasmid pOK1 restored the TolC+ phenotype with regard to mitomycin C, SDS, and colicin E1 sensitivities. A plasmid with an amber mutation in the tolC gene, designated pOK18, was isolated by the same procedure used for the isolation of pOK1. The plasmid had a molecular weight of 5.6 Md and produced the same size of DNA fragments as the tolC+ plasmid, pOK1, after digestion with the indicated restriction enzymes. The plasmid, pOK18, conferred the TolC+ phenotype when introduced into a tolC strain in the presence of, but not the absence of, an amber suppressor. Plasmid-specified polypeptides were determined by using maxicells of strains uvrA recAsup+ and uvrA recA tyrT, containing each plasmid. Three additional proteins of 54,000 (54K), 29K, and 27K were produced in maxicells containing pOK1. These three proteins were synthesized in maxicells of the uvrA recA tyrT strain carrying pOK18, whereas synthesis of the 54K protein by pOK18 did not take place in maxicells of the uvrA recA sup+ strain, although the other two proteins were produced in normal amounts. From these results we concluded that the product of the tolC gene is a protein with a molecular weight of 54K.

Bacteriophage lambda↗