Use of abdominal ultrasonography to assess pediatric splenic trauma. Potential pitfalls in the diagnosis.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of abdominal ultrasonography (US) for screening and grading pediatric splenic injury. SUMMARY BACKGROUND DATA: The use of abdominal US has increased rapidly as a method of evaluating organ damage after blunt abdominal trauma. Despite US's increasing use, little is known about its accuracy in children with splenic injury. METHODS: Children (N = 32) suffering blunt abdominal trauma who were diagnosed with splenic injury by computerized tomography (CT) scan prospectively were enlisted in this study. Degree of splenic injury was evaluated by both CT and US. The ultrasounds were evaluated by an initial reading as well as by a radiologist who was blinded as to the results of the CT. RESULTS: Twelve (38%) of the 32 splenic injuries found on CT were missed completely on the initial reading of the US. When the ultrasounds were graded in a blinded fashion, 10 (31%) of the splenic lacerations were missed and 17 (53%) were downgraded. Seven (22%) of the 32 splenic fractures were not associated with any free intraperitoneal fluid on the CT scan. CONCLUSIONS: This study has shown that US has a low level of sensitivity (62% to 78%) in detecting splenic injury and downgrades the degree of injury in the majority of cases. Reliance on free intraperitoneal fluid may be inaccurate because not all patients with splenic injury have free intra-abdominal fluid. Based on these findings, US may be of limited use in the initial assessment, management, and follow-up of pediatric splenic trauma.     

Pyloroplasty divides vagus nerve fibers to the greater curvature of the stomach. An axonal tracing study.

Recent studies have demonstrated the location in the dorsal motor nucleus of the vagus nerve (dmnX) of nerve cells that project preganglionic efferent vagus nerve fibers to the greater curvature of the stomach. Although it is clear that these fibers are contained within the vagus nerve trunks, the intra-abdominal pathways of these fibers are unknown. When a neurotracer was applied to the right gastroepiploic pedicle, nerve cells in the bilateral dmnX were labeled. If a preliminary anterior or posterior pyloroplasty was performed before the application of the neurotracer, cellular labeling was seen on the right or left side of the dmnX, respectively. Furthermore, division of the anterior Latarjet nerve eliminated labeling in cells of the left dmnX. This study demonstrates that the preganglionic vagus nerve fibers within the right gastroepiploic pedicle traverse an intramural course across the pylorus and are contained in the Latarjet nerve.     

The value of serial determination of MEGX and hyaluronic acid early after orthotopic liver transplantation

Abstract. Post-transplant assessment of early graft function has become an essential part of monitoring, especially when deciding on retransplantation. If primary non-function is indicated, retransplantation is inevitable; early graft dysfunction may be related to subsequent complications. In a prospective study in 84 patients after orthotopic liver transplantation (OLT) we measured aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), bilirubin (BIL), prothrombin time, MEGX formation, hyaluronic acid (HA) and soluble interleukin-2 receptor (sIL-2R) concentrations during the first 2 postoperative weeks; graft outcome was followed over 4 months. The aim of this study was to determine whether graft survival could be predicted by such variables early after OLT. Compared with patients with stable graft function (n= 25), patients with post-transplant icteric cholestasis (n= 30) exhibited no difference in graft survival, despite a decrease in MEGX formation to a nadir median of 12 μgL^-1 on day 10. Patients with rejection (n= 8) and septicaemia (n= 6) showed a marked decrease in MEGX values and an increase in HA and sIL-2R concentrations between postoperative days 3 and 7. Patients with primary non-function (PNF; n= 5) were characterized by strongly reduced MEGX formation (median 4 μgL) and increased HA values (median 2300 μgL^-1) on day 3 after OLT. A total of 24/84 grafts were lost within 120 days. In a survival analysis using the Cox proportional hazards regression, HA and MEGX values on day 1 were the only independent variables entering the model that showed an adequate prognostic sensitivity. At cut-off points of 22 μgL^-1 (MEGX) and 730 μgL^-1 (HA) the combined use of these parameters in a parallel approach yielded a sensitivity of 58% with a corresponding specificity of 95% for 120-day graft survival. These findings suggest that the inclusion of MEGX and HA in postoperative monitoring of OLT patients may be helpful in the early prediction of graft survival.     

Repeat sequences in block 2 of Plasmodium falciparum merozoite surface protein 1 are targets of antibodies associated with protection from malaria

Human antibodies to the block 2 region of Plasmodium falciparum merozoite surface protein 1 (MSP1) are associated with a reduced prospective risk of clinical malaria. Block 2 is highly polymorphic, but all known alleles can be grouped into three major types. Two of these types (the K1-like and MAD20-like types) contain type-specific sequences (found in all alleles of a particular type) that flank polymorphic tripeptide repeats. These repeats contain both type-specific and subtype-specific sequences. To evaluate the antibody recognition of these parts of block 2, a new panel of six recombinant proteins was used (fused type-specific flanking sequences and two representative repeat sequences for each of the K1-like and MAD20-like types separately). Extensive testing of these antigens and full-length block 2 antigens showed that human serum immunoglobulin G antibodies induced by infection can recognize (i) type-specific epitopes in the repeats, (ii) subtype-specific epitopes in the repeats, or (iii) type-specific epitopes in flanking sequences. A large prospective study in The Gambia showed that antibodies to the repeats are strongly associated with protection from clinical malaria. The results are important for design of a vaccine to induce protective antibodies, and they address hypotheses about repeat sequences in malaria antigens.     

Linkage of human cytomegalovirus glycoprotein gO variant groups identified from worldwide clinical isolates with gN genotypes, implications for disease associations and evidence for N-terminal sites of positive selection

Previously, we identified the glycoprotein gO gene, UL74, as a hypervariable locus in the human cytomegalovirus (HCMV) genome [Virology 293 (2002) 281]. Here, we analyze gO from 50 isolates from congenitally infected newborns, transplant recipients, and HIV/AIDS patients from Italy, Australia, and UK. These are compared to four gO groups described from USA transplantation patients [J. Virol. 76 (2002) 10841]. Phylogenetic analyses identified seven genotypes. Divergence between genotypes was up to 55% and within 3%. Discrete linkage was shown between seven hypervariable gO and gN genotypes, but not with gB. This suggests interactions, while gN and gO are known to form complexes with distinct conserved glycoproteins gM, gH/gL, respectively, both are involved in fusogenic entry and exit. Codon-based maximum likelihood models showed evidence for sites of positive selection. Further analyses of disease relationships should take into account these newly defined gO/gN groups.     

Alternate Pathway Activation in Sickle Cell Disease and ��-Thalassemia Major

Total hemolytic complement activity (CH50), immuno-electrophoretic conversion of Factor B (C3PA), and of C3 were studied in 16 patients with sickle cell disease in a steady state, eight patients in crisis, and ten patients with β-thalassemia major anemia maintained on a constant transfusion regimen. Patients with sickle cell disease in a steady state have moderatley 56 (percent) depressed conversion of Factor B in addition to markedly decreased conversion of C3 in four of ten patients. One of the three sickle cell patients and two of the four thalassemia patients with low C3 conversion levels have died subsequent to the studies. The combination of chronically decreased Factor B conversion in the face of markedly decreased C3 conversion may make these patients occasionally vulnerable to overwhelming infection analagous to the situation seen in postsplenectomy cases.     

Visualizing and quantifying evoked cortical activity assessed with intrinsic signal imaging

Intrinsic signal imaging (ISI) measures changes in light reflectance from the illuminated cortex (intrinsic signals or IS) attributed to various vascular and metabolic sources that, when using illumination in the 600 nm range, appear to co-localize with neuronal activity. Given the multiple sources contributing to the collected IS, the common practice of averaging across an extended post-stimulus time epoch before dividing by baseline data typically visualizes evoked IS overlying both the cortical tissue and the large surface blood vessels. In rat PMBSF, the contribution from these vessels are problematic as they do not co-localize with known PMBSF function. Determining a means for quantifying the evoked IS area poses an additional challenge. Here, we describe how exploiting IS collected shortly after stimulus onset (within 1.5 s), which coincides with fast oxygen consumption of active neurons, visualizes evoked IS overlying the cortical tissue without the large surface vessels. We also describe how the use of absolute thresholds combined with a baseline determined from data collected immediately prior to stimulus onset (within 1 s) targets most precisely a specific evoked IS amplitude, a method that should be especially useful when evoked areas are expected to occupy a substantial portion of the total imaged area and/or when peak activity is expected to differ between subjects.     

Does Body Position Affect Ultrasound Measurements of Bladder-Wall Elasticity?

Ultrasound bladder vibrometry (UBV) parameters have been shown in previous studies to strongly correlate with measurements from urodynamic studies. Just like urodynamic studies, UBV can be performed in supine and sitting positions. The objective of this study is to compare UBV parameters obtained in the two different positions using statistical methods. We recruited eight volunteers with healthy bladders for this purpose. The elasticity, group velocity squared and thickness of the bladder were the UBV parameters of interest, and their values were recorded at different bladder volumes for each volunteer. The results presented indicate that the measurements made in the two positions are in agreement using the Bland–Altman method and a parameter q which compares the values at each bladder volume for each volunteer. UBV parameters were also repeatable for measurements recorded in the supine and sitting positions.