Prmt7 Deficiency Causes Reduced Skeletal Muscle Oxidative Metabolism and Age-Related Obesity.

Maintenance of skeletal muscle function is critical for metabolic health and the disruption of which exacerbates many chronic diseases such as obesity and diabetes. Skeletal muscle responds to exercise or metabolic demands by a fiber-type switch regulated by signaling-transcription networks that remains to be fully defined. Here, we report that protein arginine methyltransferase 7 (Prmt7) is a key regulator for skeletal muscle oxidative metabolism. Prmt7 is expressed at the highest levels in skeletal muscle and decreased in skeletal muscles with age or obesity. Prmt7(-/-) muscles exhibit decreased oxidative metabolism with decreased expression of genes involved in muscle oxidative metabolism, including PGC-1α. Consistently, Prmt7(-/-) mice exhibited significantly reduced endurance exercise capacities. Furthermore, Prmt7(-/-) mice exhibit decreased energy expenditure, which might contribute to the exacerbated age-related obesity of Prmt7(-/-) mice. Similarly to Prmt7(-/-) muscles, Prmt7 depletion in myoblasts also reduces PGC-1α expression and PGC-1α-promoter driven reporter activities. Prmt7 regulates PGC-1α expression through interaction with and activation of p38 mitogen-activated protein kinase (p38MAPK), which in turn activates ATF2, an upstream transcriptional activator for PGC-1α. Taken together, Prmt7 is a novel regulator for muscle oxidative metabolism via activation of p38MAPK/ATF2/PGC-1α.

[Effectiveness of boric acid as a stomach poison for the German cockroach (Blattella germanica L.) Control]

The author carried out a study on the effectiveness of the boric acid as a stomach poison for German cockroach control from July to September 1971. The test was performed by the feeding method under conditions of 20 degrees C and 80 per cent relative humidity. The baits were composed of one control group and five different combination groups with boric acid and sugar as follows. 1)10 g sugar only(control group), 2)1 g powedered boric acid to 9 g sugar(1:9 poison baits), 3)2 g powdered boric acid to 8 g sugar(2:8 poison baits), 4)4 g powdered boric acid to 6 g sugar(4:6 poison baits), 5)5 g powdered boric acid to 5g sugar(5:5 poison baits), 6)10 g powdered boric acid only (10:0 poison baits). The insects were composed of 360 female adult German cockroaches collected by traps at the kitchens of restaurants and house holds in Seoul City. The results were as follows: 1.The total mortality by poison baits in 72 hours after treatment were: 1)44.3 % by 1:9 poison baits, 2)79.4 % by 2: poison baits, 3)96.7 % by 4:6 poison baits(the most effective poison baits), 4)88.3 % by 5:5 poison baits, 5)91.1 % by 10:0 poison baits. 2.The peak mortality by the treatment hours were: 1)Up to 21 hours: 23.3 % by 5:5 poison baits, 20.0 % by 10:10 poison baits, 2)From 24 to 48 hours: 71.1 % by 4:6 poison baits, 55.6 % by 10:0 poison baits, 3)From 48 to 72 hours: 21.9 % by 2:8 poison baits, 19.6 % by 1:9 poison baits. The most effective treatment hours was from 24 to 48 hours.

[Susceptibility Of Cockroaches (Blattella Germanica Linneaus) To Various Insecticides]

During the period from May to October 1969, the authors carried out a series of tests with the aim to ascertain the present status of susceptibility of adult cockraoches to various insecticides. The tests on the susceptibility of cockroaches to dieldrin, D.D.V.P., Diazinon; Dibrom, Malathion and lindane were performed with the topical application and the residual film methods under the conditions of 26 degrees C and 80% of relative humidity. The insects tested were collected from Seoul City and were reared at the laboratory. Some of the important results so far obtained can be summarized as follows: 1. The median lethal doses (LD-(50)) of the five insecticides against female adult cockroaches were: 0.4 microgram/roach or 4.02 microgram/body weight (gm) by Dieldrin, 0.29/roach or 2.88 microgram/body weight (gm) by D.D.V.P., 0.29 microgram/roach or 2.96 microgram/body weight (gm) by Diazinon, 0.54 microgram/roach or 5.37 microgram/body weight (gm) by Dibrom, and 2.96 microgram/roach or 29.60 microgram/body weight (gm) by Malathion. And those against male adult cockroaches were: 0.18 microgram/roach or 3.29 microgram/body weight (gm) by Dieldrin, 0.27 microgram/roach or 4.89 microgram/body weight (gm) by D.D.V.P., 0.16 microgram/roach or 2.91 microgram/body weight (gm) by Diazinon, 0.49 microgram/roach or 8.97 microgram/body weight (gm) by Dibrom, and 1.32 microgram/roach or 24.19 microgram/body weight (gm) by Malathion. 2. The level of susceptibility of adult cockroaches to the insecticides tested was 1.0-1.6 times higher as compared with the results obtained on the Japanese Takashi strain. 3. The median knockdown times (LT-(50)) of the female adult cockroaches by insectcides at 1% concentration of 3 mg per square centimetre were 1.82 hours by Malathion, 1.36 hours by Diazinon, 0.56 hours by Lindane, 0.50 hours by Dibrom, and 2.56 hours by D.D.V.P. 4. Amarked difference was seen to exist between the males and the females. The female cockroaches were more resistant than the male to Dieldrin, Diazinon and Malathion.

[Insecticide resistance in bedbugs(Cimex lectularius) in Korea]

In the summer of 1969 from July through October, authors carried out a study of susceptibility in adult female bed bug(Cimex lectularius) in order to ascertain any development of resistance to insecticides in Korea. The test to DDT and Dieldrin was performed in laboratory by the continuous exposure of residues method, with standard impregnated paper used for adult mosqitoes. Some results so far obtained can be summarised as follows: 1. LC(50) were 2.839% in DDT and 0.167% in Dieldrin. 2. The resistance has been arisen 2.4~2.9 times in DDT and 1.6~2.4 times in Dieldrin as compared with London laboratory strain, but they were susceptible 1.4 times in DDT and 180 times in Dieldrin as compared to Israel resistance strain.