The plasma lipoproteins of a 1-year-old Japanese infant were studied because of malnutrition, severe decrease in plasma lipid level, and acanthocytosis. Plasma lipoprotein analysis revealed that low-density lipoproteins were deficient; however, low levels of triglyceride-rich lipoproteins were found in the plasma. On sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis, apoprotein B-48 and a faint band corresponding to apoprotein B-100 were detected in the lipoprotein fraction of density less than 1.006 g/mL when the infant was 6 months old. Apoprotein B-48 was more clearly detected after 1 year, but the band corresponding to apoprotein B-100 on the sodium dodecylsulfate gel electrophoresis had disappeared. The apoprotein B-48 content of the fraction with density less than 1.006 g/mL was about 0.05 to 0.3 mg/dL. The patient's lipoproteins consisted mainly of high-density lipoproteins. These results suggest that the disorder in this patient is caused by apoprotein B-100 deficiency.

Abetalipoproteinemia↗

PubMed1985

Naviculo-cuneiform coalition. A report of two cases.

This solidus article reports on two unique cases of naviculo-medial cuneiform coalition in a 20-year-old man and a 22-year-old woman. In the first patient, arthrodesis was successful in relieving the localized pain, whereas in the second patient the pain gradually decreased without treatment.

Adult↗

PubMed1985

Cure of mice bearing P388 leukemia by vincristine in combination with a calcium channel blocker.

Mice inoculated with P388 leukemia were treated initially with vincristine (VCR) at a dose of either 1.5 or 2.0 mg/kg. After 1 week, VCR alone (0.1 mg/kg) was given daily for ten treatments, but no mice were cured with this regimen. However, when the calcium channel blocker verapamil (75 mg/kg) was administered with VCR at 1.5 or 2.0 mg/kg, lifespans were prolonged and one of ten or six of ten mice were cured, respectively. As reported previously, verapamil renders less sensitive or resistant tumor cells susceptible to VCR by inhibiting the VCR efflux mechanism, especially in resistant cells. Therefore, verapamil in combination with VCR apparently can result in total cell kill under the conditions used.

Animals↗

PubMed1985

Cardiac effects of fenoterol hydrobromide on newborn versus adult rats.

The toxicity of fenoterol hydrobromide, a beta-adrenoceptor stimulant, was studied in newborn and adult SD-rats dosed with 0 (control), 2.5, 75 and 600 mg/kg/day by gavage for 35 days. 600 mg/kg was lethal for both age groups: newborn rats died either from gastro-intestinal disorders during the lactation period or from underweight and cachexia immediately after weaning. Adult rats which died from 600 mg/kg showed extended myocardial scars. No substance-related myocardial lesions were observed in newborn rats killed terminally, whereas adult rats had a dose-dependent increase in heart weights, at 600 mg/kg also extended myocardial scars.

Aging↗

PubMed1984

Comparison of Clostridium botulinum toxins type D and C1 in molecular property, antigenicity and binding ability to rat-brain synaptosomes.

Botulinum type D neurotoxin was purified 950-fold from the culture supernatant with an overall yield of 32%. The purified toxin had a specific toxicity of 5.8 X 10(7) mouse minimal lethal dose per mg of protein and a relative molecular mass of 140000. The purified toxin had a di-chain structure consisting of heavy and light chains with relative molecular masses of 85000 and 55000, respectively, linked by one disulfide bond. These subunits had different amino acid compositions and antigenicities. A similarity in molecular constructions and amino acid compositions was observed between type D and type C1 toxins as well as between their subunits. Among the seven kinds of monoclonal antibodies against type D toxin, six reacted with the heavy chain of type D toxin, while one of the six also reacted with the heavy chain of type C1 toxin and neutralized the toxicities of the two toxins. The other one of monoclonal antibodies reacted with the light chains of both toxins. This evidence indicates that both toxins have common antigenic sites on their heavy and light chains and that the antigenic site on the heavy chain may contribute to the neutralization of both toxins by antibody. The binding of type D toxin to rat brain synaptosomes was examined by use of 125I-labelled type D toxin. The binding was competitively inhibited not only by unlabelled type D and C1 toxins, but also by the heavy chains of both toxins, however, it was not inhibited by the light chain of type D toxin. These results suggest that the toxin receptors on synaptosomal membrane are common for type D and C1 toxins, and that the heavy chain contributes to the binding of toxin to synaptosomes and the structure of the binding sites on the heavy chains of both toxins is quite similar.

Amino Acids↗

PubMed1984

Self-adaptive modification of red-cell membrane lipids in lecithin: cholesterol acyltransferase deficiency. Lipid analysis and spin labeling.

In a patient with lecithin: cholesterol acyltransferase deficiency, free cholesterol was markedly increased, and esterified cholesterol was diminished. In the patient's plasma, an increase in phosphatidylcholine (PC) and a decrease in sphingomyelin were observed. Concomitantly, an increase in a shorter acyl chain 16:0 was noted in PC, sphingomyelin and phosphatidylethanolamine (PE). In contrast to these results, longer chains such as 22:0 and 24:0 were decreased, especially in sphingomyelin. Unsaturated double bonds such as 18:1 was also increased in PC and PE. In the red-cell membrane lipids, the increase in free cholesterol was counteracted by an increase in PC and by a decrease in sphingomyelin and PE, reflecting changes in the patient's plasma lipids. Increased 16:0 (in PC) and decreased 18:0 and 24:0 were observed. The increased plasma free cholesterol due to metabolic defect (lecithin: cholesterol acyltransferase deficiency) led to decreased red-cell membrane fluidity. This effect appeared to be counteracted by changing phospholipid composition (increased PC and decreased sphingomyelin and PE), by increasing shorter chains (16:0), by decreasing longer chains (18:0 and 24:0) and by increasing unsaturated double bonds (18:2). These results can be interpreted as a self-adaptive modification of lecithin: cholesterol acyltransferase deficiency-induced red-cell membrane abnormalities, to maintain normal membrane fluidity. This speculation was supported by the ESR spin-label studies on the patient's membrane lipids. The normal order parameters in intact red cells and in total lipid liposomes were decreased if cholesterol-depleted membrane liposomes were prepared. Thus, the hardening effect of cholesterol appeared to be counteracted by the softening effects described above. Overall membrane fluidity in intact red cells of the lecithin: cholesterol acyltransferase-deficient patient was maintained normally, judged by order parameters in ESR spin-label studies.

Cholesterol↗

PubMed1984

Morphological studies of the goldfish hindgut mucosa in organ culture.

The morphology of the absorptive cells of the goldfish hindgut mucosa, and their capability for horseradish peroxidase (HRP) uptake, were investigated by electron microscopy after a 24-h organ culture. The columnar appearance and the fine structure of the absorptive cells were well preserved for 24 h at room temperature and 37 degrees C with 5% CO2 in air, in all the media used in this study. Mitoses were frequently observed in the epithelium at the bottom of cultured mucosal folds, and re-epitheliazation was also observed in many explants. Some structural changes were, however, noted in the cultured absorptive cells, as compared with the non-cultured absorptive cells; the deep invaginations of the surface membrane between the microvilli decreased in number; supranuclear giant vacuoles were reduced in size or almost disappeared; the distributional pattern of mitochondria in the absorptive cells was altered. The HRP uptake experiments showed that the absorptive cells cultured for 24 h could still take up HRP by endocytosis and transport it, indicating that the absorptive cells maintained their capability of macromolecule uptake and transport after 24 h of culture. In addition, HRP experiments, in which reaction product was detected within numerous cytoplasmic tubules (CT), various vacuoles and CT-vacuole complexes, suggested a close relationship between CT and vacuolar system in the apical cytoplasm during endocytotic events in the absorptive cells.

Animals↗

PubMed1984

Alterations in erythrocyte membrane lipids in abetalipoproteinemia: phospholipid and fatty acyl composition.

Scanning electron microscopic observation revealed that there were wide variations including typical acanthocytes in morphology of erythrocytes from a patient with abetalipoproteinemia. The erythrocyte membrane phospholipids and cholesterol contents from a patient was higher by 25% compared to an age-matched control subject. Analysis of phospholipid composition of red blood cells showed an increase of sphingomyelin (25.1----30.1%) with a concomitant decrease of lecithin (27.5----21.0%). Thus, the sphingomyelin/lecithin ratio was increased dramatically (0.91----1.43). As for fatty acyl chain composition of main phospholipids, an increased percentage of palmitic acid and docosahexaenoic acid and a decreased proportion of arachidonic acid and lignoceric acid were observed for sphingomyelin. There was an increment of palmitic acid which was accompanied with a decrease of linoleic acid in lecithin. On the other hand, no significant difference was shown in the fatty acid composition of phosphatidylethanolamine and phosphatidylserine plus phosphatidylinositol between a patient and control.

Abetalipoproteinemia↗

PubMed1984

Specific early-G1 blocks accompanied with stringent response in Saccharomyces cerevisiae lead to growth arrest in resting state similar to the G0 of higher eucaryotes.

Growth arrests of Saccharomyces cerevisiae cells in early G1 phase brought by various means were classified into two types according to the mode of growth recovery after release of the restraints against growth. The first type, including arrests caused by cdc25, cdc33, cdc35, and ils1 mutations at the nonpermissive temperature and also by sulfur starvation, showed a subsequent delay in the onset of budding when shifted back to permissive conditions. The length of the delay was positively correlated with the time that cells had been arrested. The second type, including those caused by cdc28 and cdc24 mutations and by alpha factor, did not affect the mode of growth recovery after the shift to permissive conditions irrespective of the time that cell proliferation had been restricted. Growth arrests of the first type seem to allow yeast cells to enter a resting state equivalent to the G0 state of higher eucaryotes because features of the G0 shown with lymphocytes and other cultured cells including unusually long delay before the growth recovery (L.H. Augenlicht and R. Baserga, 1974, Exp. Cell Res., 89:255-262; and Kumagai, J., H. Akiyama, S. Iwashita, H. lida, and I. Yahara, 1981, J. Immunol., 126:1249-1254) appeared to be associated with this type. We have noted that arrests of the first type were always accompanied with a stringent response of macromolecular synthesis and its partial release by cycloheximide. Mapping of arrest points along the path of the cell cycle by the reciprocal shift experiment suggested that arrest points in G1 that led to the G0-like arrest precede or are near the step sensitive to alpha-factor.

Cell Cycle↗

PubMed1984

Durable synthesis of high molecular weight heat shock proteins in G0 cells of the yeast and other eucaryotes.

We report that eucaryotic cells were induced to synthesize a specific class of heat shock proteins (hsps) when they entered the resting state, G0. This finding was originally made with Saccharomyces cerevisiae cells by taking advantage of the system in which we can distinguish between G1 arrests leading to G0 and those that do not result in G0 (Iida, H., and I. Yahara, 1984, J. Cell Biol. 98:1185-1193). Similar observations were subsequently made with higher eucaryotic cells including chick embryonic fibroblasts (CEF), mouse T lymphocytes, and Drosophila GM1 cells. The induction of hsps in G0 cells was distinct from that in heat-shocked cells in two respects. First, hsps with molecular weight around 25,000 were not induced in G0 cells, whereas most, if not all, high molecular weight (HMW) hsps were commonly induced both in G0 cells and in heat-shocked cells. Second, in contrast to the transient synthesis of hsps in heat-shocked cells, G0 cells continued to synthesize hsps at the stimulated rate for a relatively long period. These results suggest the possibility that high molecular weight hsps might function in a transition from the proliferating state to G0 or in maintaining G0 in the eucaryote.

Animals↗

PubMed1984

A heat shock-resistant mutant of Saccharomyces cerevisiae shows constitutive synthesis of two heat shock proteins and altered growth.

A heat shock-resistant mutant of the budding yeast Saccharomyces cerevisiae was isolated at the mutation frequency of 10(-7) from a culture treated with ethyl methane sulfonate. Cells of the mutant are approximately 1,000-fold more resistant to lethal heat shock than those of the parental strain. Tetrad analysis indicates that phenotypes revealed by this mutant segregated together in the ratio 2+:2- from heterozygotes constructed with the wild-type strain of the opposite mating type, and are, therefore, attributed to a single nuclear mutation. The mutated gene in the mutant was herein designated hsr1 (heat shock response). The hsr1 allele is recessive to the HSR1+ allele of the wild-type strain. Exponentially growing cells of hsr1 mutant were found to constitutively synthesize six proteins that are not synthesized or are synthesized at reduced rates in HSR1+ cells unless appropriately induced. These proteins include one hsp/G0-protein (hsp48A), one hsp (hsp48B), and two G0-proteins (p73, p56). Heterozygous diploid (hsr1/HSR1+) cells do not synthesize the proteins constitutively induced in hsr1 cells, which suggests that the product of the HSR1 gene might negatively regulate the synthesis of these proteins. The hsr1 mutation also led to altered growth of the mutant cells. The mutation elongated the duration of G1 period in the cell cycle and affected both growth arrest by sulfur starvation and growth recovery from it. We discuss the problem of which protein(s) among those constitutively expressed in growing cells of the hsr1 mutant is responsible for heat shock resistance and alterations in the growth control.

Crosses, Genetic↗

PubMed1984

Treatment of headache with antidepressant.

Headache was classified, in conformity to the classification of headache as specified by the Ad Hoc Committee, into migraine, contraction and combined types and others. Tricyclic antidepressant clomipramine having pharmacological properties, which are said to relatively and uniquely inhibit the reuptake of serotonin in the synapses, was administered for headaches and the clinical effects on headaches were examined. Headaches assumed to be attributable to depression were excluded by means of quationing and Zung's self-rating depression scale. Furthermore, the MMPI, MPI and MAS mentality tests were also employed to clarify the characters and traits of these patients with headache. Also, the biochemical mechanism playing a part in the occurrence of headache was conjectured from the pharmacological action pattern of the antidepressant.

Adult↗