[Effect of cepharanthin on peripheral leukocytopenia caused by antineoplastic agents]

One of the problems in administration of anticancer drugs is a decrease of peripheral blood leucocytes which causes reduction of defense mechanism against various infections. In this study, for the purpose of protecting leucopenia after administration of anticancer drugs, an effect of cepharanthine which is a kind of alkaroid materials was examined in normal and tumor-bearing mice. Peripheral leucocytes of both normal and tumor-bearing mice receiving anticancer drugs gradually decreased during first two weeks, and in third and forth week they decreased rapidly. On the other hand, leucopenia was improved by simultaneous administration of anticancer drugs and cepharanthin; however, a complete repairment was hardly expected when anticancer drugs were continuously administered. A significant recovery of leucocytes was observed in mice receiving cepharanthin compared to those receiving only anticancer drugs. In any process of decreasing and recovering from peripheral leucocytes, proportions of differential counts of leucocytes were approximately identical. On the colony forming experiment for granulocytic stem cell (CFU-C) using bone marrow cells of normal, anticancer drugs-treated, and anticancer drugs plus cepharanthin-treated mice, it has been suggested that cepharanthin might have some influencing activity on hematopoietic cells or cell-mediated activity on hematopoiesis only in vivo.

Priming of reovirus transcription by GppppG and formation of CpG(5')GpC

Compounds of general structure N(5')pn(5')N were used by the reovirus-associated RNA polymerase as primers for template-directed synthesis of virus-specific oligonucleotides and RNA. Structural requirements for activity included a guanosine residue and at least four phosphates--i.e., G(5')pppp(5')N. Gp4G incubated with viral cores in the presence of CTP yielded Gp4GpC and CpGp4GpC. In a complete transcription mixture, Gp4G was also incorporated into the 5' termini of full-length transcripts in the unmethylated forms Gp4GpC and CpGp4GpC, in contrast to viral mRNAs that contain 5'-terminal m7GpppGmpC formed de novo. Gp5G, Gp6G, and Gp4A but not Gp2G, Gp3G, and Ap4A also primed reovirus transcription and inhibited RNA methylation.

Serum levels of acetate and TCA cycle intermediates during hemodialysis in relation to symptoms

In order to study the metabolism of acetate transferred from dialysate, the plasma concentrations of organic acids including the tricarboxylic acid cycle (TCA cycle) intermediates were measured during hemodialysis in a comparative study between acetate dialysate and bicarbonate dialysate in 17 patients on maintenance hemodialysis treatment. Continuous measurements of serum concentrations of these organic acids during hemodialysis were performed using the filtrate obtained through an ultrafiltrate sampling device. The organic acids were measured by isotachophoresis. Serum acetate, malate and citrate concentration increased with time in acetate dialysis compared with bicarbonate dialysis. Correlations were found between these organic acids. Isocitrate became detectable when the serum acetate concentration was over 7 mmol/l which was correlated to the acetate concentration, and was accompanied by the development of symptoms. The above results suggest that an acetate overload on the patients during acetate dialysis affects acetate metabolism through the TCA cycle resulting in an accumulation of organic acids in the serum and the development of symptoms.

[Clinical evaluation of cefroxadine dry syrup in children (author's transl)]

Clinical efficacy of cefroxadine dry syrup, a new oral cephalosporin antibiotic, was evaluated in children, and the following results were obtained. 1. Three children were given a single oral dose of about 10 mg/kg of the drug when fasting, and its blood concentrations were determined. Blood concentrations were maximum at 30 approximately 60 minutes, i.e., 16.9 approximately 18.2 microgram/ml, and markedly low at 4 hours. 2. Thirty-six patients with the following diseases were tested with 23.1 approximately 44.4 mg/kg/day of the drug in 3 to 4 divided doses; 21 patients with lacunar tonsillitis, 2 with tonsillitis, 1 with scarlet fever, 4 with bronchitis and tonsillitis, 2 with cystitis, 4 with pyelonephritis, 1 with impetigo and 1 with probable Mycoplasma pneumonia. An overall efficacy rate in 35 patients excluding the last mentioned case was 91.4%, i.e., excellent in 20, good in 12 and poor in 3, and an eradication rate of the causative organisms was 88.9%. 3. Adverse reactions noted were diarrhea in 1 patient, eruption and diarrhea in 1 transient neutropenia in 1, eosinophilia in 3 and an elevation of GOT and GPT in 1. None were significant. 4. Taste and flavor of the drug was considered to be well palatable to children. 5. Taking into consideration of the results of fundamental evaluation of the drug, cefroxadine dry syrup is considered to be a potent new antibiotic in children, and the recommended dose will be 10 mg/kg 3 to 4 times a day.

Chemical methylation of RNA and DNA viral genomes as a probe of in situ structure

We used [methyl-(3)H] dimethyl sulfate to probe the genome structures of several RNA and DNA viruses. We compared sites of modification in nucleic acids that were methylated chemically before and after extraction from purified virions. With both single-stranded and double-stranded substrates alkylation occurred mainly at the N7 position of guanine. However, adenine N1 atoms were differentially accessible in single-stranded RNA and DNA. For example, the ratios of 1-methyladenosine to 7-methylguanosine for reovirus mRNA and deproteinized genome RNA were 0.43 and 0.03, respectively. Members of the Reoviridae methylated in situ yielded RNAs with ratios of 0.04 to 0.08, indicating that the intravirion genomes were double stranded. We obtained ratios of 0.26 and 0.35 for the RNAs of dimethyl sulfate-treated brome mosaic and avian sarcoma virions, respectively, which was consistent with partial protection of adenine N1 sites by structural proteins or genome conformation or both. The ratios of 1-methyladenosine to 7-methylguanosine for vaccinia virus DNAs methylated in situ (0.10) and after phenol extraction (0.14) were less than the ratios for phiX174 and M13 DNAs (0.39 to 0.64) but considerably greater than the ratio observed with adenovirus DNA (0.002 to 0.02). The presence of a single-stranded region(s) in the vaccinia virus genome was confirmed by S1 nuclease digestion of [methyl-(3)H] DNA; the released radiolabeled fraction had a ratio of 0.41, compared with 0.025 for the residual duplex DNA. In addition to the structure-dependent accessibility of adenine N1, methylation of adenine N3 was severalfold lower in the intravirion genomes of vaccinia virus, phiX174, and adenovirus than in the corresponding extracted DNAs. Chemical methylation of virions and subviral particles should be useful for in situ analyses of specific regions of RNA and DNA genomes, such as the sites of protein binding during virus maturation.

Excess synthesis of viral mRNA 5-terminal oligonucleotides by reovirus transcriptase

Short oligonucleotides corresponding to the 5'-terminal sequence of reovirus mRNAs were produced in vitro by virion-associated transcriptase activity. Both capped and uncapped oligonucleotides were synthesized in molar excess relative to mRNA. Yields of uncapped oligomers including ppG-C and ppG-C-U were severalfold greater than the homologous capped structures. In partial reaction mixtures that were nonsupportive for mRNA chain elongation, capped oligomer synthesis was increased. Similarly, oligonucleotide formation was differentially resistant in viral preparations that were inactivated with respect to mRNA synthesis by modification of the genome RNA by dimethyl sulfate alkylation or psoralen photoreaction. The results suggest that reovirus mRNA synthesis involves excessive initiation by reiterative transcription of promoter sites by the reovirus polymerase. Only a small fraction of the resulting oligonucleotides are capped and extended to form full length mRNAs during a subsequent elongation step which is apparently mediated by transcriptase molecules that escape the reiterative phase of transcription.

[An evaluation of characteristics of motion corrector attached to a gamma-camera (author's transl)]

The characteristics of the motion corrector system attached to LFOV gamma-camera (Searle) was evaluated using a T-shaped plane source and point sources. The random movement without rotation of a T-shaped plane source was successfully corrected. However, rotating motion of the plane source was not corrected. When a point source placed on a rotating table, ring images were obtained. When motion corrector was used, the radius of ring images was increased with the increase of rotating speed and it was decreased with the increase of radioactivity of the source. Line images were obtained when point sources were placed on a shaker, which caused linear periodic motion of the sources. The use of the motion corrector reduced the length of line images.

The quantitative structure-selectivity relationship of anthracycline antitumor activity and cardiac toxicity

Quantitative structure-activity relationships (QSAR) are developed for both the antitumor activity (B-16 melanoma) and cardiotoxicity of a set of anthracycline derivatives, for the purposes of finding exploitable differences between the two which would lead to improvements in the therapeutic indices of these compounds. It was found that most structural features which lead to improvement in antitumor activity, such as increases in drug hydrophilicity, also lead to increases in cardiotoxicity. However, demethoxylation and demethoxylation at the 4-position of these molecules appears to have much greater effect on cardiotoxicity than on antitumor activity. If these effects are brought about by alterations in the oxidation-reduction potential of the quinone structure, as is suggested, then it may be possible to make analogs with a better therapeutic index by the introduction of small hydrophilic electron-releasing groups in the A-ring of these adriamycin derivatives that are conjugated with the carbonyl functions.

Superiority of hemofiltration to hemodialysis for treatment of chronic renal failure: comparative studies between hemofiltration and hemodialysis on dialysis disequilibrium syndrome

A significantly lower incidence of DDS, hypotension, and impending shock was found during and after hemofiltration as compared with conventional hemodialysis. Hemofiltration, in contrast to hemodialysis, showed less decrease of circulating plasma volume, mild change in plasma osmolality without red cell swelling, better compensation of acidosis despite less uptake of acetate, more stable PCO2 during the procedure, less paradoxical acidosis in cerebrospinal fluid, and a lower urea concentration gradient between cerebrospinal fluid and plasma. These phenomena might be explained by better mass transfer between compartments bithin the body during hemofiltration. Mass transfer from the intracellular as well as the extracellular space to circulating plasma occurred more rapidly and smoothly during HF than during HD. HF is preferable to HD in patients with severe cardiovascular complications such as hypertension, as well as hypotension and cardiac failure, and in those subject to DDS during HD. Accordingly, hemofiltration therapy promises patients more comfortable and more stable treatment of chronic uremia.

Translation of animal virus RNA in the cytoplasm of a plant cell

Isolated Acetabularia crenulata nuclei were injected with Mengo virus RNA solution and then implanted into anucleate posterior Acetabularia mediterranea cell fragments or fused with Acetabularia ryukyuensis cytoplasts. The injected animal virus RNA was actively translated in the plant cell cytoplasm. Mengo virus proteins were detected and localized in Acetabularia cytoplasts by use of an immunofluorescence method on the first to fifth day after injection.