Haemophilia A: database of nucleotide substitutions, deletions, insertions and rearrangements of the factor VIII gene, second edition.

A large number of different mutations in the factor VIII (F8) gene have been identified as a cause of haemophilia A. This compilation lists known single base-pair substitutions, deletions and insertions in the F8 gene and reviews the status of the inversional events which account for a substantial proportion of mutations causing severe haemophilia A.     

Measurements of urinary adipic acid and suberic acid using high-performance liquid chromatography

A sensitive and specific method was developed for measuring medium-chain dicarboxylic acids (adipic and suberic acid) in urine. These acids were extracted from urine with diethyl ether and converted into fluorescent derivatives with 9-anthryldiazomethane, which can be separated by high-performance liquid chromatography. The reproducibility was high and the recovery from urine was above 90%. Urinary concentrations of adipic acid in streptozotocin-induced diabetic rats were significantly higher than those in control rats. In diabetic patients, both adipic acid and suberic acid tended to be high, but not significantly. This method should be useful for measuring dicarboxylic acids in urine     

A unique electrophoretic slow-moving glucose 6-phosphate dehydrogenase variant (G6PD Asahikawa) with a markedly acidic pH optimum

Summary A new glucose 6-phosphate dehydrogenase (G6PD) variant associated with chronic nonspherocytic hemolytic anemia was discovered in Japan. The patient showed hemolytic crises after upper respiratory infections. The enzyme activity was about 3.8% of the normal. The partially purified enzyme revealed slow anodal electrophoretic mobility, high Km NADP, marked thermal-instability, and increased affinity for a substrate analogue (deamino-NADP). A particular characteristic of this enzyme was a biphasic pH curve with a greatly increased activity at low pH values. From these results, this variant was clearly different from hitherto observed G6PD variants, and was designated G6PD Asahikawa.     

Localization of triphosphoinositide in the cochlea

Summary Triphosphoinositide (TPI) has been demonstrated to be a receptor for aminoglycosides in the cochlea and may regulate ionic permeability by its binding with Ca⁺⁺. This phospholipid was localized by a protein A-gold technique in the cochlea at the electronmicroscopic level. TPI was prepared by a neomycin column and antibodies to it were raised in rabbits. The antibody used in this study reacted virtually only to TPI among the tested lipids. TPI was localized mainly at stereocilia, cuticular plates, head plates of Deiter's cells, plasma membrane, and mitochondria of various cells in the organ of Corti. In the vascular stria, TPI was found mainly at the plasma membrane of basal infoldings of the marginal cells. Possible physiological and pathophysiological roles of TPI in the cochlea are briefly discussed.     

Immunological responses of hamsters in the acquired immune state to Mycoplasma pneumoniae infection

Protective effects of vaccination of hamsters against Mycoplasma pneumoniae infection, evaluated according to the recovery of mycoplasmas and histopathological changes in the respiratory tract after challenge infection, persisted for at least 6 months after the final vaccination. Serum antibody levels reached a maximum in the second week after the last vaccination and decreased markedly between the first and the third months, but increased again in sera obtained from animals given booster injections. Metabolism-inhibiting antibodies were detected in bronchial washings of animals showing high resistance obtained by vaccinal or passive immunization. Antiserum transfer was also effective for protection but cell-mediated immune responses were not demonstrated in any animals up to 6 months after the vaccination. Even after 10 months, suppression of both mycoplasmal proliferation and lung lesions was apparent, and a single dose of the vaccine induced a significant booster effect. These findings suggest that (1) humoral immunity is more important than cell-mediated immunity in resistance of hamsters to M. pneumoniae pneumonia, and (2) the antibody secreted in the respiratory tract may be involved in the local defense mechanisms.     

Trichoclin,a new furocoumarin from trichocline incana

The structure for trichoclin, (E)-8-(3-methyl-4-hydroxy-2-butenyloxy)-psoralen, a new furocoumarin isolated from Trichocline incana, has been established. Phellopterin and isopimpinellin were also obtained. The new side chain of trichoclin was confirmed by synthesis.     

Autoprocessing of Drosophila copia gag precursor to generate a unique laminate structure in Escherichia coli.

Drosophila copia protease is likely to be encoded in the gag gene. We have expressed copia gag polyprotein precursor in E. coli. The gag precursor was correctly processed to generate a unique laminate structure in E. coli. The processing was almost completely blocked by a mutation at the putative active site of copia protease, and resulted in accumulation of the precursor. Furthermore, the laminate structure was not found in E. coli expressing the mutant precursor. These results indicate that the protease is involved in cleaving the gag precursor itself. Also, the assembly of copia gag protein should correlate to the autoprocessing of copia gag polyprotein precursor.     

Effect of aliphatic alcohols on the conformation of poly (l-ornithine hydrobromide) as studied by square-pulse and reversing-pulse electric birefringence

The electric birefringence and circular dichroism spectra of poly(l-ornithine hydrobromide) have been measured in ethanol/water, 2-propanol/water and tertiary butyl alcohol/water mixtures of various compositions. This charged polypeptide underwent a transition from the coil conformation to the helical conformation at high alcohol content in every case tested. Anomalous birefringence signals, indicative of a field-induced helix-to-coil transition. were observed at high electric fields only in the case of ethanol/water mixtures. The reversing-pulse electric birefringence of this polypeptide has been studied in ethanol/water mixtures and in neutral aqueous solution. Upon rapid reversal of the pulse field, no transient could be observed. This confirms that the electric-field orientation of poly(l-ornithine hydrobromide) results predominantly from the contribution of the counterion-induced dipole moment, regardless of its molecular conformations. It is very probable that the backbone permanent dipole moment of the helical conformation is largely suppressed by the counterion-induced dipole moment in the ionized form.