Extraction of aluminum from fly-ash by commercial and microbiologically-produced citric acid

Summary Aluminum extraction from two aluminum-rich fly-ashes by commercial and microbiologically-produced citric acids was tested. Up to 12% Al₂O₃ of the total was extracted by a 21 hrs¹ shaking treatment at 60° C. Extraction efficiency is considerably affected by extracting acid concentration and extraction temperature. The extraction efficiency of microbiologically-produced citric acids was only slightly lower than that of commercial citric acid of equal molarity.     

Alterations in the time of X chromosome replication induced by 5-azacytidine in a patient with 48,XXXY/47,XXY

It has recently been shown that 5-azacytidine (5-azaC) can induce altered replication patterns of the late-replicating X chromosome in normal female cells. This has been demonstrated by bromodeoxyuridine labelling of cells late in the S phase. In the present study the same method was applied to the lymphocytes of a Klinefelter patient (48,XXXY/47,XXY). Significant 5-azaC-induced changes in the replication of the entire inactive X chromosome, from late to early, were found in the lymphocytes of this patient. These results indicate that hypomethylating agents can not only alter the replication of individual bands, but also change the gross replication schedule of multiple inactive X chromosomes in the presence of a Y chromosome.     

Pseudohypoparathyroidism type Ia: two new heterozygous frameshift mutations in exons 5 and 10 of the Gsα gene

Pseudohypoparathyroidism type Ia (PHP-Ia) is a hereditary disease characterized by resistance to PTH and other hormones that act via cAMP. Patients have deficient activity of Gs, the subunit of the G protein, which couples hormone receptors to stimulation of adenylate cyclase. We describe two new mutations discovered in two sporadic patients with PHP-Ia. Using genomic DNA, we have amplified exons 2–13 of the Gs gene (GNAS1) by PCR, and sequenced the resulting products. Both patients had Albright's hereditary osteodystrophy, resistance to multiple hormones, and deficient Gs activity. In the first patient, a deletion of a C in exon 5 at codon 115 was found. In the second patient, an insertion of a C in exon 10 at codon 267 was detected. Both these heterozygous mutations cause frameshift, and predict decreased production of Gs. This report adds two new Gs mutations to the known ten mutations recently described.     

Detection of aflatoxigenic molds in grains by PCR.

Aflatoxins are carcinogenic metabolites produced by several members of the Aspergillus flavus group in grains and floods. Three genes, ver-1, omt-1, and apa-2, coding for key enzymes and a regulatory factor in aflatoxin biosynthesis, respectively, have been identified, and their DNA sequences have been published. In the present study, three primer pairs, each complementing the coding portion of one of the genes, were generated. DNA extracted from mycelia of five Aspergillus species, four Penicillium species, and two Fusarium species was used as PCR template for each of the primer pairs. DNA extracted from peanut, corn, and three insect species commonly found in stored grains was also tested. Positive results (DNA amplification) were achieved only with DNA of the aflatoxigenic molds Aspergillus parasiticus and A. flavus in all three primer pairs. The detection limit of the PCR was determined by using the primer pairs complementing the omt-1 and ver-1 genes. Sterile corn flour was inoculated separately with six different molds, each at several spore concentrations. Positive results were obtained only after a 24-h incubation in enriched media, with extracts of corn inoculated with A. parasiticus or A. flavus, even at the lowest spore concentration applied (10(2) spores per g). No DNA spores per g). It is concluded that genes involved in the aflatoxin biosynthetic pathway may form the basis for an accurate, sensitive, and specific detection system, using PCR, for aflatoxigenic strains in grains and foods.     

Ecdysteroid level and the change in sensitivity to a juvenile hormone analogue in Ephestia cautella larvae (Lepidoptera,Phycitidae)

A double-antibody ecdysone-specific radioimmunoassay was used to clarify whether the effects on metamorphosis of the juvenile hormone analogue methoprene are correlated with changes in ecdysteroids level. It appears that a small ecdysteroids peak, 5 days before pupation, is responsible for the transition from inhibition to defective metamorphosis. Study of the changes in ecdysteroid titer in last-instar larvae treated with the JHA 2 days prior to the appearance of the above small ecdysteroids' peak showed an immediate reduction in ecdysteroid level, followed by cyclic, successively reduced titer for about 20 days. After this period the larvae ceased to feed and entered to a diapauselike stage which ended in the death of the larvae. A similar effect on ecdysteroid titer and developmental arrest was exhibited by JHA-treated first-instar larvae. The mechanism of the interactions between JHA and ecdysteroid level deserves further investigation.     

Modifications of myelin basic protein which occur during its isolation.

Abstract— Chromatography of myelin basic protein (BP) on carboxymethylcellulose gives a pattern of multiple components, of which three are major. Component 1 is considered the unmodified species of BP while component 2 has been found to be modified primarily by deamidation and component 3 by phosphorylation (Chou et al., 1976). ³ 3 The numbering system for the components is that used by DEIBLER & MARTENSON (1973) for guinea pig BP and is preferred over the reverse system of numbering used by CHOU et al. (1976); i.e. components 1, 2 and 3 of DEIBLER & MARTENSON (1973) are the same as components 6, 5 and 4 of CHOU et al. (1976), respectively.
In contrast to BP prepared from tissue delipidated in the standard fashion in chloroform–methanol (CM powder), BP prepared from tissue delipidated first in acetone and then in chloroform–methanol (ACM powder) gave an elution pattern on carboxymethylcellulose characterized by a decrease in component 1 and an increase in the earlier eluting, less basic components. Studies with radiolabelled component 1 showed that this difference in elution patterns was due to the partial conversion of component 1 to less basic components during the extraction of ACM powder at neutral pH. The components derived from component 1 (D2, D3 and D4) were then isolated and subjected to tryptic peptide map analyses and determination of their carboxy-terminal arginine content and content of phosphorus. None of the derived components contained phosphorus but tryptic peptide map analyses did show the presence of two minor peptides, T14M₂ and T20M, previously found in component 2 from CM powder and considered to be the deamidation products of their parent peptides T14 and T20 (Chou et al., 1976). In addition components D3 and D4 were shown to have lost appreciable arginine from their carboxy-termini. Since none of the efforts to reduce enzyme activity in vitro had any appreciable effect on components 2 and 3 it was concluded that phosphorylation probably occurs exclusively in vivo, that deamidation occurs both in vivo and in vitro and that loss of carboxy-terminal arginine occurs exclusively in vitro.