No abstract

Background: Our study seeks to clarify the extent of differences in analytical results, from a clinical perspective, among 4 leading technologies currently used in clinical reference laboratories for the analysis of LDL subfractions: gradient gel electrophoresis (GGE), ultracentrifugation-vertical auto profile (VAP), nuclear magnetic resonance (NMR), and tube gel electrophoresis (TGE). Methods: We collected 4 simultaneous blood samples from 40 persons (30 males and 10 females) to determine LDL subclasses in 4 different clinical reference laboratories using different methods for analysis. LDL subfractions were assessed according to LDL particle size and the results categorized according to LDL phenotype. We compared results obtained from the different technologies. Results: We observed substantial heterogeneity of results and interpretations among the 4 methods. Complete agreement among methods with respect to LDL subclass phenotyping occurred in only 8% (n ‫؍‬ 3) of the persons studied. NMR and GGE agreed most frequently at 70% (n ‫؍‬ 28), whereas VAP matched least often. Conclusions: As measurement of LDL subclasses becomes increasingly important, standardization of methods is needed. Variation among currently available methods renders them unreliable and limits their clinical usefulness.

An increased level of oxidative stress was associated with high levels of physical exertion of training in a cold environment at moderate altitude. The antioxidant mixture tested did not attenuate the mean oxidative stress levels in the entire group of test subjects, but it may have reduced the oxidative stress of some individuals with low initial antioxidant status.

Unstimulated whole saliva and stimulated whole, parotid, and labial minor gland saliva samples were collectedfrom 25 patients with oral lichen planus and from 25 age-and sex-matched controls between the ages of 25 and 87 years. All subjects did not smoke or chew tobacco, had no serious illnesses, and were unmedicated. There were no significant differences in flow rates between the two groups. However, a significant age-related decrease in labial minor gland saliva flow rate was found in both the lichen planus group and the controls. Flow rates of unstimulated and stimulated whole saliva and stimulated parotid saliva were not related to age in either group.

Special Operations place great physical demands on personnel. In most Navy settings, greater physical demands are associated with greater musculoskeletal injury rates. Within the Special Operations community, Special Boat operators have a unique set of risks. Small boats operating in the open ocean are subject to large shock and vibration forces. Exposure to such forces can lead to discomfort, injury and performance degradation. In an effort to begin assessing the prevalence of injuries related to operations in small Special Operations craft, a self-report survey of injuries (SBUIS) was administered to 154 operator personnel drawn from Special Boat Units 12,20 and 22. Sample mean age was 32.0 ± 5.9 yr., mean years of military service was 12.0 ± 5.5, and mean time in Special Boats was 4.7 ± 3.0 yr. The SBUIS obtained demographic information, unit assignment and role information, past general pain levels, details about up to three specific injuries, and exercise history information. Specific injury information included type and location of injury, and type and duration of care for that injury. Of the respondents, 95 reported one injury event, 11 reported 2, and 5 reported 3. The 121 injury events resulted in 153 separate injuries.The most prevalent type of injury was sprains and strains (49.3%) followed by disc problems (7.9%) and trauma (7.9%). The most prevalent injury sites were the lower back (33.6%), knee rates for the Navy as a whole. Hospitalization incidence for the survey respondents was 2,687 per 100,000 person-years exposure. The overall Navy rate for the combination of injuries reported in this sample was 479 per 100,000 personyears. Only constructionmen (CN), seamen (SN), firemen (FN), and airmen (AN) had greater hospitalization rates than SBU respondents. We conclude that SBU personnel are at greater than average risk of injury associated with SBU training and operations. These findings need to be confirmed. If confirmed, methods to reduce the injury risk must be identified and implemented.