THE IMPACT OF DIABETES MELLITUS ON SKELETAL MUSCLE MASS AND STRENGTH IN OLDER ADULTS

In older adults, diabetes is a serious public health problem because of high prevalence as well as its devastating consequences such as functional disability and high mortality. Loss of muscle mass and strength, called sarcopenia, has been considered as a common pathway leading to loss of function and frailty in older adults. We investigated the impact of diabetes on skeletal muscle mass and strength in 3,075 older adults aged 70 to 79, enrolled in the Health, Aging and Body Composition Study. Diabetes was defined not only by self report or medication use, but also by fasting plasma glucose and the result of 75-g oral glucose challenge test. Muscle mass was measured by state of the art techniques such as dual-energy X-ray absorptiometry (DXA) and computed tomography (CT). Muscle strength was assessed quantitatively by isometric and isokinetic dynamometers. Muscle quality was defined as maximal muscle strength per unit muscle mass. In cross-sectional study, we found that muscle strength was significantly lower in men with diabetes and not higher in women with diabetes despite of having greater muscle mass than those without diabetes. Muscle quality was consistently lower in both men and women with diabetes than non-diabetic counterparts in both upper and lower extremities. We also found that longer duration (greater than or equal to 6 yrs) and poor glycemic control (A1c > 8.0 %) were associated with even lower muscle quality. In longitudinal study, older adults with diabetes showed about 50% greater declines in leg muscle strength compared with those without diabetes. Leg muscle quality also declined more rapidly in older adults with diabetes. Skeletal muscle mass, estimated by DXA, declined more rapidly in older adults with diabetes. Interestingly, loss of muscle mass was more pronounced in undiagnosed diabetes. Thigh muscle area by CT declined two times faster in older women with either diagnosed or undiagnosed diabetes than non-diabetic women. The public health importance of these findings is that diabetes is clearly a risk factor for loss of muscle mass and strength in older adults. We need to develop a strategy to prevent rapid loss of muscle mass and strength in this high risk population

Salmonella typhimurium harboring plasmid expressing interleukin-12 induced attenuation of infection and protective immune responses

IL-12 is known to be an essential cytokine which appears to provide protective immunity against intracellular bacteria, such as Salmonella. In this study, we investigated the possibility of developing a vaccine using IL-12 against virulent Salmonella. We used the host defense system activated by cytokine IL-12. The highly virulent Salmonella strain (Salmonella typhimurium UK-1) was transformed with cytokine-expressing plasmids. These live, wild-type pathogens were used as vaccine strains without undergoing any other biological or genetic attenuating processes. The newly developed strains induced partial protection from infections (30-40%). Of note, the interleukin-12 transformed pathogen was safe upon immunization with low doses (103 CFU), induced IgG responses, and stimulated protective immune responses against Salmonella Typhimurium in mice (80-100%). These results suggest that IL-12 induced attenuation of wild-type Salmonella in the host infection stage and vaccine development using the wild-type strain harboring IL-12 secreting plasmids may be considered as an alternative process for intracellular bacterial vaccine development without the inconvenience of time-consuming attenuation processes

Development of a Chaff Dispense Program for Target Tracking Radar Deception

This study aims to develop an appropriate chaff dispensing program to deceive the target tracking radar (TTR) effectively. Chaff is a countermeasure commonly used by fighter aircraft to deceive TTR. However, there has been a lack of methodology for calculating chaff dispense programs that take into account the specific characteristics of the fighter, chaff, and TTR. This study proposes a methodology that considers these variables to calculate chaff dispense programs and addresses this gap. The proposed method is demonstrated through TESS engagement, which shows its effectiveness in various engagement situations