Citations

The inverse problems in the area of the acoustic scattering often concern the determination of the size, shape, and orientation of an object using the scattered field data. This paper presents a method to retrieve the shape information of an underwater object using illuminated lengths, which can be obtained from the ramp response signatures of the object. An ellipsoidal object submerged in water is considered. Both the low and high backscattered frequency data have been employed to calculate the illuminated lengths. The calculated results show that the illuminated lengths will be more accurate, if only the high-frequency-range data are employed. For ellipsoidal objects, any three illuminated lengths that are not of a same plane can in theory fully determine the shape of the ellipsoid. As the calculated illuminated lengths contain numerical errors, the calculated results of the three semiaxes of the ellipsoid will deteriorate and become unreliable, especially when the three incident directions of the illuminated lengths become close. The reason is that the condition number of the coefficient matrix becomes big in such situations, which leads to an increase of the relative error upper limit in the calculated results. To avoid such errors in close incident wave cases, it is found that the use of more than three incident waves works very well in the shape identification of an underwater object.

Abstract Glucocorticoids (GCs) are commonly used to treat inflammatory disease; unfortunately, the long-term use of these steroids leads to a large number of debilitating side effects. The antiinflammatory effects of GCs are a result of GC receptor (GR)-mediated inhibition of expression of proinflammatory genes as well as GR-mediated activation of antiinflammatory genes. Similarly, side effects are most likely due to both activated and repressed GR target genes in affected tissues. An as yet unachieved pharmaceutical goal is the development of a compound capable of separating detrimental side effects from antiinflammatory activity. We describe the discovery and characterization of AL-438, a GR ligand that exhibits an altered gene regulation profile, able to repress and activate only a subset of the genes normally regulated by GCs. When tested in vivo, AL-438 retains full antiinflammatory efficacy and potency comparable to steroids but its negative effects on bone metabolism and glucose control are reduced at equivalently antiinflammatory doses. The mechanism underlying this selective in vitro and in vivo activity may be the result of differential cofactor recruitment in response to ligand. AL-438 reduces the interaction between GR and peroxisomal proliferator-activated receptor γ coactivator-1, a cofactor critical for steroid-mediated glucose up-regulation, while maintaining normal interactions with GR-interacting protein 1. This compound serves as a prototype for a unique, nonsteroidal alternative to conventional GCs in treating inflammatory disease.

BACKGROUNDA 13‐year retrospective study was undertaken to determine the incidence of posttonsillectomy hemorrhage, to evaluate potential risk factors, and to assess the efficacy and safety of ambulatory tonsillectomy.METHODSFrom January 1985 to December 1997, 4662 patients underwent tonsillectomy at our institution. Ninety patients with posttonsillectomy bleeding were identified. For each patient with posttonsillectomy bleeding, 2 nonbleeding control subjects were selected and matched by age and sex to evaluate potential risk factors.RESULTSAge was the only factor found to be statistically significant among the bleeding patients and the control group. The highest incidence (3.61%) of posttonsillectomy hemorrhage occurred in patients 21 to 30 years of age. In our experience, secondary hemorrhage was more common than primary hemorrhage, presenting most frequently on postoperative days 5 to 7.CONCLUSIONSThe incidence of posttonsillectomy bleeding in this review was 1.93%, and about half (47%) of the patients with posttonsillectomy hemorrhage returned to the operating room for hemorrhage control. The highest incidence (3.61%) of posttonsillectomy hemorrhage occurred in patients 21 to 30 years of age. Patients with posttonsillectomy hemorrhage, regardless of management, had a 12% incidence of subsequent hemorrhage. We found no difference in the incidence of posttonsillectomy bleeding between outpatient and inpatient procedures.

ABSTRACT In a previous study which evaluated the BACTEC 9240 automated blood culture system (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.), we noted a 1.3% “instrument false-positive” rate. That is, the BACTEC system signaled that a bottle (BACTEC Plus Aerobic/F bottle or BACTEC Anaerobic Lytic/10 bottle) culture was positive but a Gram stain was negative and there was no growth of bacteria or yeasts on subculture to chocolate agar. Furthermore, from the same sample of blood, cultures for fungi using the Isolator blood culture system (Wampole Laboratories, Cranbury, N.J.) were negative for growth. For the present study, we evaluated 76 instrument false-positive samples for the presence of 16S ribosomal DNA using the MicroSeq 500 kit (PE Biosystems, Foster City, Calif.). These samples also were negative for fungi by the Isolator method. This kit has a PCR module and sequencing module for the amplification and sequencing of the 16S RNA gene and provides a database for sequence alignment and identification of bacteria. To optimize the assay, we evaluated the effect of adding 0.5% bovine serum albumin to the sample from blood culture bottles and found that it decreased the effects of inhibitors on the PCR. Two control groups of blood culture specimens were also evaluated. One group ( n = 45) were “instrument true positives”; the instrument signaled positive, and subsequent Gram stains were positive and subcultures on chocolate agar grew bacteria. The other group ( n = 20) were “instrument true negatives”; the instrument signaled negative, the Gram stain was negative, and subcultures on chocolate agar and from the Isolator tube on fungal media showed no growth. None of the 76 instrument false-positive samples had evidence for 16S rRNA gene sequences. All of the instrument true-positive samples and all of the instrument true-negative specimens were positive and negative, respectively, using the MicroSeq 500 kit. Total peripheral white blood cell counts were statistically significantly higher for patients who had instrument false-positive results than for patients who had instrument true-positive or true-negative results ( P = 0.001). We conclude that instrument false positives signaled by the BACTEC 9240 system are not due to bacteria in the blood culture samples.

ABSTRACTDuring the first 45 days after intracerebral infection with Theiler's murine encephalomyelitis virus (TMEV), the levels of mRNAs encoding chemokines MCP-1/CCL2, RANTES/CCL5, and IP-10/CXCL10 in the central nervous system (CNS) are closely related to the sites of virus gene expression and tissue inflammation. In the present study, these chemokines were monitored during the latter 135 days of a 6-month course of TMEV-induced disease in susceptible (PLJ) or resistant (C57BL/6) mice that possessed or lacked either CD4+or CD8+T cells. These data were additionally correlated to mouse genotype, virus persistence in the CNS, antiviral antibody titers, mortality, and the severity of neurological disease. Surprisingly, the major determinant of chemokine expression was virus persistence: the factors of susceptible or resistant genotype, severity of neuropathology, and presence or absence of regulatory T cells exerted minimal effects. Our observations indicated that chemokine expression in the CNS in this chronic viral disorder was intrinsic to the CNS innate immune response to infection and was not governed by elements of the adaptive immune system.