Chromosomal assignment of amplified genes in hydroxyurea-resistant hamster cells

We have shown previously that cDNAs for the M1 and M2 subunits of ribonucleotide reductase, ornithine decarboxylase (ODC), and p5-8, a 55,000-Dalton protein, hybridize to amplified genomic sequences in a highly hydroxyurea-resistant hamster cell line. We have extended these observations to include two additional, independently isolated, hydroxyurea-resistant cell lines: SC8, a single-step hamster ovary cell line, and KH450, a multistep human myeloid leukemic cell line, have also undergone genomic amplification for sequences homologous to ODC and p5-8 cDNAs. However, neither SC8 nor KH450 contains amplified genomic sequences homologous to an M1 cDNA probe. A panel of mouse-hamster somatic cell hybrids was used to map sequences homologous to M1, M2, ODC, and 5-8 cDNAs in the hamster genome. The M2, ODC, and p5-8 cDNAs hybridized to DNA fragments that segregated with hamster chromosome 7. In contrast, M1 cDNA hybridized to DNA fragments that segregated with hamster chromosome 3. These data suggest that the genes RRM2, (M2), ODC, and p5-8, but not RRMI (M1), are linked and may have been co-amplified in the selection of the hydroxyurea-resistant hamster and human cell lines.     

Escherichia coli CAN lacks a tRNA-processing nuclease.

Escherichia coli strain CAN is unable to support the growth of bacteriophage T4 strains requiring the suppressor function of T4 tRNASer. Biochemical analysis of the mutant strain revealed that it is deficient in a RNase which acts on the artificial tRNA precursor tRNA-C-U.     

Multi-Targeting Tacrine Conjugates with Cholinesterase and Amyloid-Beta Inhibitory Activities: New Anti-Alzheimer's Agents

Alzheimer's disease (AD) is a severe age dependent and chronic problem with no cure so far. The available treatments are temporary, acting over short period of time. The main pathological hallmark of the disease includes cholinergic dysfunction, oxidative stress, accumulation of Aβ fibrils and tau tangles. In context with the multi-factorial nature of this disease, two different series of molecules were developed to hit the multifactorial disease targets. Mainly, the molecules were designed to inhibit the AChE and aggregation of Aβ, and also oxidative damage. Two novel series of TAC-fenbufen/menbutone conjugated molecules were designed, synthesized and bio-assayed. All compounds showed inhibition capacity towards AChE, Aβ aggregation and moderate to good radical scavenging capacity. Particularly, five TAC-menbutone molecules showed improved AChE and Aβ aggregation inhibition capacity compared to TAC-fenbufen conjugated molecules. Overall, these novel series of molecules may be potential drug lead molecules in the treatment of AD.     

Preliminary X-ray investigation of a bifunctional inhibitor from Indian finger millet (ragi).

A bifunctional alpha-amylase/trypsin inhibitor that has two binding sites has been purified from ragi. The inhibitor has been crystallized from its ammonium sulphate solution by the vapour diffusion method. The crystals belong to the orthogonal space group P2(1)2(1)2(1) with unit cell dimensions a = 30.49 A, b = 56.30 A, c = 73.65 A and Z = 4.     

Certain observations on Scytonema stuposum (Kuetz.) Born. (Cyanophyta,Nostocales)

Some interesting cultural observations on Scytonema stuposum (Kuetz.) Born., were recorded. It was observed that frequently one or more terminal cells of a branch get cut off but they still remain attached over the sheath of the mother filament. Even in this condition such structures continue their growth and may become a multicellular body. Later, such a structure gets detached from the mother filament and serve as a hormogonium.     

Influence of capsaicin,curcumin and ferulic acid in rats fed high fat diets

Three compounds capsaicin, curcumin and ferulic acid showing hypolipidemic activity have been tested in adult Wistar rats fed high fat diets. Capsaicin (0.20 mg%) fed to female rats along with a 30% saturated fat diet lowered the rate of weight gain, liver and serum triglycerides. In male rats it lowered only the liver and serum total and very low density and low density lipoprotein triglycerides whether fed continuously for 13 or 8 weeks after interchanging the control and test diets from the 5th week onwards. Capsaicin fed to female rats in 30% mixed fat diet increased the rate of weight gain, lowered liver and serum triglycerides, lowered adipose tissue lipoprotein lipase, elevated the hormone sensitive lipase and serum free fatty acids. Capsaicin in 30% saturated fat diet lowered both the enzyme activities to a much lesser extent. Curcumin and ferulic acid (both at 25 mg%) in 30% saturated fat diet tended to lower the rate of weight gain, liver total lipids and serum triglycerides. It is of significance that a common dietary compound ‘capsaicin’ in the range of human intake triggers lipid lowering action in rats fed high fat diets. This paper was presented at the 55th Annual Meeting of the Society of Biological Chemists (India) held at Trivandrum during December 15–17th, 1986.