Gender differences in subjective distress attributable to anticipation of combat among U.S. Army soldiers deployed to the Persian Gulf during Operation Desert Storm

This study compares perceptions of stress, cohesion, and psychological well-being among 856 male soldiers and 169 female soldiers from combat support and combat service support units deployed to the Persian Gulf during Operation Desert Storm. Three different types of stressors were measured: anticipation of combat, operational stress, and personal stress. Female soldiers scored higher than male soldiers on all three measures of stress but scored lower than males on horizontal and vertical cohesion. In a stepwise discriminant function analysis, anticipation of combat was the most significant discriminator between the genders, followed by horizontal cohesion. Anticipation of combat was a significant predictor of increased psychological symptoms for both genders, but it had a greater effect on the psychological symptoms of female soldiers compared with male soldiers.     

Responses and limitations of the respiratory system to exercise

During maximal exercise, the gas exchange function of the lung is challenged because of the major cardiopulmonary changes that must occur to meet the increased metabolic demands imposed by exercise. In healthy untrained young adults, the respiratory system is able to meet these demands imposed on it during maximal exercise by implementing several key mechanisms. Nonetheless, there are several exceptional cases in which the lung is unable to accommodate the demands of exercise because of vascular or airway limitations.     

Is Human Ovulation Concealed? Evidence from Conception Beliefs in a Hunter-Gatherer Society

Several researchers have suggested that ovulation may not be concealed in humans living under natural conditions with minimal hygiene. Because measuring coital frequency in such a population is problematic, I tested this proposition indirectly by asking Hadza hunter-gatherers of Tanzania when a woman can get pregnant. If people (1) know that pregnancy is caused by sex, and people (2) say that women conceive in the middle of the menstrual cycle, we might infer that people think women conceive in the middle of the cycle because most copulations occur then. If copulation peaks strongly around ovulation, it is not concealed. The Hadza know that pregnancy is caused by sex but most say conception occurs right after menstruation ends. Hadza conception beliefs therefore do not suggest that ovulation is more detectable in humans under more natural conditions.     

Minimally invasive total knee replacement: principles and technique

Recent attention toward minimally invasive approaches to joint replacement has resulted in new MIS TKA techniques for the implant of conventional TKA implant components. These proposed techniques must be evaluated thoroughly and changes approached with caution. Medial and lateral techniques that minimize interruption and dissection of neuro-vascular tissues, muscles, tendons, and ligament shave been described. Patients who have undergone these procedures have benefited short term from quicker recovery time and less pain and have benefited long term from the use of conventional prosthesis. Before MIS can become an accepted surgical technique for TKA, a clear understanding of the unique guiding principles behind MIS TKA must be understood and realized. Once these basic principles are followed and the surgeon is familiar with MIS TKA techniques, this technique should prove to be a substantial step forward in the continuum of TKA procedure development.     

Application of an rRNA probe matrix for rapid identification of bacteria and fungi from routine blood cultures

One of the most important functions of the clinical microbiology laboratory is the identification of the etiology of sepsis. For this study, aliquots from 405 positive blood cultures were tested against a unique array of DNA probes directed against rRNA subsequences of bacteria and fungi for identification. Another 280 samples that were negative after 5 days of incubation were also tested. Blood culture bottles were incubated in a BacT/Alert3D instrument. For the rRNA assay, a 0.4-ml aliquot was removed, and the cells were pelleted by centrifugation. The pellet was washed and frozen at -70 degrees C. Analysis of the pellet involved a lysis step and then the addition of samples to the reaction wells containing the probes in a microtiter plate format. Analysis was performed by using a hybridization protection assay. Results were taken through a series of deductive steps to obtain species, or in some cases genus, identification. Batch sample preparation required approximately 15 min, and sample analysis required another 60 min. Probe results were compared to conventional biochemical identifications. The probe test was negative for the 280 samples that were negative by the BacT/Alert 3D system and for another 21 samples that were false positive (the instrument signaled, but there was no growth). Microorganisms from the remaining 384 signal-positive samples included 60 Enterobacteriaceae, 10 Pseudomonas aeruginosa, 10 other gram-negative bacteria, 40 Staphylococcus aureus, 152 coagulase-negative staphylococci, 28 streptococci, 22 enterococci, 21 other gram-positive bacteria, 8 anaerobes, and 16 yeast organisms. Seventeen cultures were polymicrobial, and one was gram positive and culture negative. Discordance between probe and conventional identification results was noted for only 12 (1.75%) samples. This novel rapid molecular approach to the identification of bacteria and yeast in blood cultures was highly sensitive (100%) and specific (96%).     

Fenestral and cochlear otosclerosis: computed tomographic evaluation

Computed tomography has replaced conventional multidirectional tomography in the imaging of patients with the presumed diagnosis of otosclerosis. In addition to obliterative disease, which was easily diagnosed with multidirectional tomography, anterior and posterior foci of varying sizes can now also be visualized preoperatively. Active cochlear otosclerosis (otospongiosis) is diagnosed in the presence of foci of demineralization in the otic capsule. Diagnosis of these entities has been of great interest to our referring otologic surgeons.     

In vivo emergence of drug-resistant mutations at less than 50 HIV-1 RNA copies/mL that are maintained at viral rebound in longitudinal plasma samples from human immunodeficiency virus type-1-infected patients on highly active antiretroviral therapy

OBJECTIVE: Emergence of human immunodeficiency virus type-1 (HIV-1) genotypic drug resistance is generally attributed to noncompliance, poorly absorbed drugs, or drug-to-drug interaction. Attempts to determine emerging genotypic drug resistance from study subjects on highly active antiretroviral therapy (HAART) relied on insensitive polymerase chain reaction (PCR) techniques, revealing wild type HIV-1 or precursor resistant genotypes from few plasma samples successfully amplified with <50 copies/mL. STUDY DESIGN/METHODS: In this analysis, using Applied Biosystems' ViroSeq HIV-1 Genotyping Systems, Version 2.0 (Applied Biosystems, Foster City, CA, USA) and the supplemental, for research use only, nested PCR primers, genotypic drug resistance was determined in longitudinal plasma samples from 11 study subjects on HAART. RESULTS: In 4 of 11 study subjects, newly emerging genotypic primary resistant mutations were detected in plasma samples with <50 copies/mL. Most of these primary drug-resistant mutations were detected in subsequent longitudinal samples with detectable viral load (viral breakthrough). CONCLUSIONS: This analysis suggests sufficient viral replication <50 copies/mL to generate genotypic drug resistance in study subjects on suppressive HAART.