DNA modifications by the mutagen glyoxal: adduction to G and C, deamination of C and GC and GA cross-linking

OBJECTIVE: This study aimed to describe the clinical and histopathologic findings in four patients with complex limbal choristomas associated with linear nevus sebaceous syndrome (LNSS), a rare disorder including nevus sebaceous, seizures, and mental retardation, and often accompanied by ocular anomalies. DESIGN: Small observational case series. METHODS: A retrospective review of the clinical and histopathologic records of four patients. RESULTS: Each of four patients had complex limbal choristomas in the setting of clinical and histopathologic LNSS. The limbal choristomas were multiple in three patients and bilateral in two patients. Most choristomas involved the superotemporal limbus (6 of 10), although nasal (3 of 10) and inferior (1 of 10) limbal tumors also were present. Three patients had significant corneal astigmatism or involvement of the central cornea requiring surgical removal of their choristomas, one accompanied by a lamellar keratoplasty and another accompanied by two consecutive penetrating keratoplasties. Each graft eventually vascularized, reducing vision. One patient's vision was limited by amblyopia and another by occipital cortical dysgenesis with visual impairment. Histopathologic examination of the excised choristomas showed foci of lacrimal gland (3 of 4 patients), adipose tissue (3 of 4), neural tissue (1 of 4), cartilage (1 of 4), lymphoid follicles (1 of 4), skin adnexal tissue (1 of 4), and smooth muscle (1 of 4). Other associated ocular findings included an eyelid mass (1 of 4), colobomas of the eyelid (3 of 4), colobomas of the choroid and retina (2 of 4), nonparalytic strabismus (2 of 4), scleral ectasia (1 of 4), partial oculomotor palsy with ptosis and anisocoria (1 of 4), microphthalmia (1 of 4), hypertelorism (1 of 4), and cortical visual impairment (1 of 4). CONCLUSIONS: Complex limbal choristomas, although rare, can occur in the setting of LNSS and can be associated with multiple ocular and systemic abnormalities. Visual prognosis appears poor in most cases despite aggressive management.     

Purification of four forms of the beta gamma subunit complex of G proteins containing different gamma subunits

To investigate the physiological significance of the diversity of gamma subunits of G proteins, we purified four forms of beta gamma of G proteins from bovine brain (beta gamma-B1, beta gamma-B2, beta gamma-B3), and spleen (beta gamma-S1) by the sequential chromatography on columns of DEAE-Sephacel, Ultrogel AcA 34, heptylamine-Sepharose, phenyl-5PW, and DEAE-5PW. Electrophoretic analyses showed that each beta gamma mainly contained the 36-kDa beta and a distinct but homogeneous gamma. These beta gamma complexes were subjected directly to proteolytic digestion and subsequent amino acid sequence analyses of their fragments. It was revealed that beta gamma-B1, -B2, and -B3 were identical to beta 1 gamma 7 (with a low level of beta 2 gamma 7), beta 1 gamma 2 and beta 1 gamma 3, respectively, while beta gamma-S1 was composed of beta 1 and an unidentified form of gamma. Then we examined the functional differences among these beta gamma complexes and the beta gamma of transducin (beta gamma-T, beta 1 gamma 1). Few differences were observed among all beta gamma complexes to enhance pertussis toxin-catalyzed ADP-ribosylation of the alpha subunits of G(o) and Gt. The four forms of beta gamma complexes purified from brain and spleen showed indistinguishable inhibitory effects on the release of GDP from G(o) alpha, but beta gamma-T was much less effective. Brain and spleen beta gamma complexes were equally effective in inhibiting calmodulin-stimulated adenylyl-cyclase activity, but beta gamma-T had a very weak inhibitory effect. Five forms of beta gamma facilitated metarhodopsin II-catalyzed binding of GTP gamma S to Gt alpha in a concentration-dependent manner with the following rank order of effectiveness: beta gamma-S1 > beta gamma-T > beta gamma-B1 > beta gamma-B2 > beta gamma-B3. Because the beta gamma complexes used in this study mostly contained the same beta subunit, the functional differences must be dependent on the gamma subunits. Thus, it seems likely that the receptor, the alpha subunits, and the effector are able to distinguish between the various gamma subunits.     

Microencapsulation of hepatitis B core antigen for vaccine preparation

PURPOSE: To prepare poly(lactide-co-glycolide)(PLGA) microspheres containing recombinant hepatitis B core antigen (HBcAg; Mw = 3,600,000) by a w/o/w emulsion/solvent evaporation method and evaluate the possibility of this system as a potent long-acting carrier for hepatitis B core antigen in mice. METHODS: Various additives had been incorporated in the internal aqueous phase during the process of microencapsulating HBcAg, HBcAg antigenicity in the medium extracted from the prepared microspheres were measured by ELISA. Shape confirmation of the HBcAg antigen was performed by a sucrose gradient velocity centrifugal technique. For in vivo study, prepared microspheres were administered subcutaneously to Balb/C mice, and the serum IgG level was determined by ELISA. RESULTS: The inactivation of HBcAg by methylene chloride was dramatically reduced by the addition of gelatin (4-8% (w/v)) to the internal aqueous phase during the preparation. Further improvement of the loading efficiency to almost 61% resulted with cooling (4 degrees C). The prepared microspheres (4.27 microm+/-1.23 microm) containing 0.15% HBcAg displayed burst release (50-60% within 2 days). In subcutaneous inoculation, the adjuvant effect of PLGA microspheres was almost the same as that of the complete Freund's adjuvant. Whereas oral inoculation using the microspheres was not effective. CONCLUSIONS: The pH of the added gelatin seemed to be the key to the stabilization of HBcAg from various stability tests and CD spectrum study. Finally, the possibility of using this system as a potent long-acting hepatitis B vaccine was demonstrated.     

A primary algorithm for the understanding of logic circuit diagrams

This paper describes a primary algorithm that inputs information of logic circuit diagrams by designers into a computer automatically executing a local area processing. The algorithm tracks signal lines that have thickness using a line sensor. A line sensor detects particular areas such as branches, crosses, L type junctions, logic symbol areas and so on. When the pending signal line is recognized as ending at the output-side of a logic symbol, its input-side is examined precisely and the kind (OR, AND or INVERTER), the numbers of input signal lines and so forth are recognized.     

Analyses of microbial community within a composter operated using household garbage with special reference to the addition of soybean oil

A commercially available composter was operated using fixed composition of garbage with or without the addition of soybean oil. The composter was operated without adding seed microorganisms or bulking materials. Microflora within the composter were analyzed by denaturing gradient gel electrophoresis (DGGE) in the case of oil addition, or by 16/18 S rRNA gene sequencing of the isolated microorganisms in the case of no oil addition. The results showed that, irrespective of the addition of oil, the bacteria identified were all gram positive, and that lactobacilli seemed to be the key microorganisms. Based on the results, suitable microflora for use in a household composter are discussed.     

The rate of an exchange reaction of hydrogen and deuterium in a Mg2Ni bed

Hydrides of intermetallic compounds of Mg₂Ni have a comparatively large isotopic effect in the equilibrium isotherm between hydrogen and deuterium or tritium. An experimental and analytical study is made on the isotopic exchange reaction of hydrogen and deuterium in a Mg₂Ni bed for isotope separation. Values of the first moment, the second moment and a height equivalent to a theoretical plate (HETP) are obtained on the basis of a pulse or a step change of an influent deuterium concentration. It is found that the HETP values have the least at an optimum temperature and linear velocity, and the value is about 3 cm. The activation energy of the isotopic exchange reaction of Mg₂Ni is 18.5 kJ mol⁻¹. Thus the Mg₂Ni bed serves as an effective method for the isotopic separation of hydrogen isotopes.