Semicontinuous penicillin production by two Penicillium chrysogenum strains immobilized in calcium alginate beads

Summary The growth rates of immobilized Penicillium chrysogenum strains are important in their application to semicontinuous penicillin production. Immobilized P. chrysogenum strains produced about 10–15% less biomass but about 1–2 times more penicillin than free suspended mycelia.In a chemically defined medium an industrial P. chrysogenum strain, S₁, produced about 10–12 times more penicillin than strain ATCC 12690. In a complex medium the immobilized P. chrysogenum S₁ produced about 12% penicillin more than in shaken cultures. In bubble column fermentations, penicillin production was 163% higher in the complex medium than in the chemically defined medium.     

Prostaglandin profiles in nervous tissue and blood vessels of the brain of various animals

The endogenous formation of prostaglandin (PG) D2, E2, F2 alpha, and 6-keto-PGF1 alpha was determined in homogenates of mouse, rat, and rabbit brain, and of rat cerebral blood vessels, using gas chromatography mass spectrometry. In all species tested, 6-keto-PGF1 alpha could be identified in the brain homogenates, but was a minor component in relation to other PGs. In contrast 6-keto-PGF1 alpha was the most abundant PG in the blood vessels, being present in about 40-fold higher levels than in the brain tissue. PGD2 was the most abundant PG in rat and mouse brains, but was below detection limits in the analyzed blood vessels. These studies indicating differential metabolism of PG endoperoxides in nervous and vascular tissue, provide a biochemical basis for further studies on the role of the PGs in brain circulation and neuronal activity.     

A new mechanism of regulation of rat liver acetyl-CoA carboxylase activity

A factor has been found in rat liver supernatant solution which inhibits acetyl-CoA carboxylase activity regardless of the presence or absence of Mg2+ and ATP. Inactivation of the enzyme has been demonstrated via radiochemical and spectrophotometric assay procedures. The inactivation of acetyl-CoA carboxylase is not attributable to either malonyl-CoA decarboxylase activity, to phosphorylation of the enzyme, or to action on substrates or cofactors of the reaction. The activity of the inhibitor is destroyed by heating to 70-80 degrees C for 5 min or by treatment with trypsin. Dialyzing the inhibitor for 24 h at 4 degrees C does not alter its activity in inhibiting acetyl-CoA carboxylase. Hence, it appears that the inhibitor is a regulatory protein that acts directly on acetyl-CoA carboxylase.     

Trisubstituted and tetrasubstituted pyrazolines as a novel class of cell-growth inhibitors in tumor cells with wild type p53

Derivatives with scaffolds of 1,3,5-tri-substituted pyrazoline and 1,3,4,5-tetra-substituted pyrazoline were synthesized and tested for their inhibitory effects versus the p53^+/+ HCT116 and p53^?/? H1299 human tumor cell lines. Several compounds were active against the two cell lines displaying IC₅₀ values in the low micromolar range with a clearly more pronounced effect on the p53^+/+ HCT116 cells. The compound class shows excellent developability due to the modular synthesis, allowing independent optimization of all three to four key substituents to improve the properties of the molecules.     

Non-traditional Alu evolution and primate genomic diversity

Alu elements belonging to the previously identified "young" subfamilies are thought to have inserted in the human genome after the divergence of humans from non-human primates and therefore should not be present in non-human primate genomes. Polymerase chain reaction (PCR) based screening of over 500 Alu insertion loci resulted in the recovery of a few "young" Alu elements that also resided at orthologous positions in non-human primate genomes. Sequence analysis demonstrated these "young" Alu insertions represented gene conversion events of pre-existing ancient Alu elements or independent parallel insertions of older Alu elements in the same genomic region. The level of gene conversion between Alu elements suggests that it may have a significant influence on the single nucleotide diversity within the genome. All the instances of multiple independent Alu insertions within the same small genomic regions were recovered from the owl monkey genome, indicating a higher Alu amplification rate in owl monkeys relative to many other primates. This study suggests that the majority of Alu insertions in primate genomes are the products of unique evolutionary events.     

Incorporation of chlorohexidin diacetate into cotton fabrics grafted with glycidyl methacrylate and cyclodextrin

Linear electron beam radiation was used to induce grafting of glycidyl methacrylate/β-cyclodextrin mixture onto cotton fabric. Chlorohexidin diacetate was incorporated to the cavities of cyclodextrin fixed on the cotton fabric to form an inclusion complex having antimicrobial activity. After incorporating chlorohexidin diacetate, the fabric was subjected to several washing cycles to examine the durability of the antimicrobial finishing. Control and grafted cotton fabrics (before and after loading with antimicrobial agent) were characterized for their antimicrobial activity against different kinds of bacteria and fungi.Grafted fabrics loaded with antimicrobial agent were found to show good antimicrobial activity in comparison with control and grafted fabrics which are not loaded with antimicrobial agent. The grafted fabrics loaded with antimicrobial agent were found also to exhibit good antimicrobial activity after five washings and this lasting antimicrobial activity can be attributed to the inclusion complex formed between chlorohexidin diacetate molecules and the cavities of cyclodextrin.     

Distribution of the HIV resistance CCR5-Delta32 allele among Egyptians and Syrians

A mutant allele of the beta-chemokine receptor gene CCR5 bearing a 32-basepair (bp) deletion that prevents cell invasion by the primary transmitting strain of HIV-1 has recently been characterized. Individuals homozygous for the mutation are resistant to infection, even after repeated high-risk exposure, but this resistance appears not absolute, as isolated cases of HIV-positive deletion homozygotes are emerging. The consequence of the heterozygous state is not clear, but it may delay the progression to AIDS in infected individuals. In order to evaluate the frequency distribution of CCR5-Delta32 polymorphism among Egyptians, a total of 200 individuals (154 from Ismailia and 46 from Sinai) were tested. Only two heterozygous individuals from Ismailia carried the CCR5-Delta32 allele (0.6%), and no homozygous (Delta32/Delta32) individuals were detected among the tested samples. The presence of the CCR5-Delta32 allele among Egyptians may be attributed to the admixture with people of European descent. Thus we conclude that the protective deletion CCR5-Delta32 is largely absent in the Egyptian population.     

Analysis of the human <Emphasis Type="Italic">Alu</Emphasis> Ye lineage

Background  

Alu elements are short (~300 bp) interspersed elements that amplify in primate genomes through a process termed retroposition. The expansion of these elements has had a significant impact on the structure and function of primate genomes. Approximately 10 % of the mass of the human genome is comprised of Alu elements, making them the most abundant short interspersed element (SINE) in our genome. The majority of Alu amplification occurred early in primate evolution, and the current rate of Alu retroposition is at least 100 fold slower than the peak of amplification that occurred 30–50 million years ago. Alu elements are therefore a rich source of inter- and intra-species primate genomic variation.     

Preparation and characterization of poly(acrylic acid)-hydroxyethyl cellulose graft copolymer

Poly(acrylic acid) hydroxyethyl cellulose [poly(AA)-HEC] graft copolymer was prepared by polymerizing acrylic acid (AA) with hydroxyethyl cellulose (HEC) using potassium bromate/thiourea dioxide (KBrO(3)/TUD) as redox initiation system. The polymerization reaction was carried out under a variety of conditions including concentrations of AA, KBrO(3) and TUD, material to liquor ratio and polymerization temperature. The polymerization reaction was monitored by withdrawing samples from the reaction medium and measuring the total conversion. The rheological properties of the poly(AA)-HEC graft copolymer were investigated. The total conversion and rheological properties of the graft copolymer depended on the ratio of KBrO(3) to TUD and on acrylic acid concentration as well as temperature and material to liquor ratio. Optimum conditions of the graft copolymer preparation were 30mmol KBrO(3) and 30mmol TUD/100g HEC, 100% AA (based on weight of HEC), duration 2h at temperature 50°C using a material to liquor ratio of 1:10.