High bone density masks architectural deficiencies in an individual with spinal cord injury

Context

Spinal cord injury (SCI) causes a decline of bone mineral density (BMD) in the paralyzed extremities via the gradual degradation and resorption of trabecular elements. Clinical tools that report BMD may not offer insight into trabecular architecture flaws that could affect bone''s ability to withstand loading. We present a case of a woman with a 30-year history of SCI and abnormally high distal femur BMD.

Findings

Peripheral quantitative-computed tomography-based BMD for this subject was ∼20% higher than previously published non-SCI values. Computed tomography (CT) revealed evidence of sclerotic bone deposition in the trabecular envelope, most likely due to glucocorticoid-induced osteonecrosis. Volumetric topologic analysis of trabecular architecture indicated that the majority of the bone mineral was organized into thick, plate-like structures rather than a multi-branched trabecular network. Visual analysis of the CT stack confirmed that the sclerotic bone regions were continuous with the cortex at only a handful of points.

Conclusions

Conventional clinical BMD analysis could have led to erroneous assumptions about this subject''s bone quality. CT-based analysis revealed that this subject''s high BMD masked underlying architectural flaws. For patients who received prolonged glucocorticoid therapy, excessively high BMD should be viewed with caution. The ability of this subject''s bone to resist fracture is, in our view, extremely suspect. A better understanding of the mechanical competency of this very dense, but architecturally flawed bone would be desirable before this subject engaged in activities that load the limbs.     

Identification of a second T-cell antigen receptor in human and mouse by an anti-peptide gamma-chain-specific monoclonal antibody.

We developed a monoclonal antibody (mAb) (9D7) against a synthetic peptide (P13K) selected from the deduced amino acid sequence of the constant region of the gamma chain of the murine T-cell antigen receptor (TCR) (amino acids 118-130). Using this mAb, we identified a putative second TCR expressed on peripheral blood lymphocytes from a patient with severe combined immunodeficiency (SCID) that were propagated in culture with recombinant interleukin 2 (rIL-2) and Con A. This mAb immunoprecipitated two polypeptide chains of 40 and 58 kDa under nonreducing conditions and of 40 and 56 kDa under reducing conditions from 125I-labeled denatured lysates of T3+ WT31- lymphocytes expanded in culture from a SCID patient. These polypeptide chains were not disulfide linked and were not present on human peripheral blood lymphocytes from normal donors cultured for 5 days with phytohemagglutinin or for 2 weeks with rIL-2 and polyclonal activators or on cells of the Jurkat lymphoblastoid human T-cell line. Chemical crosslinking of 125I-labeled cells followed by immunoprecipitation with anti-Leu-4 mAb under nonreducing or reducing conditions revealed that the 40- and 56-kDa polypeptide chains were associated with the T3 differentiation antigen. These results were confirmed by sequential immunoprecipitation with anti-Leu-4 mAb followed by 9D7 anti-P13K mAb. The 9D7 anti-P13K mAb immunoprecipitated two polypeptide chains of 43 and 64 kDa from denatured lysates of lymphocytes from a patient with severe common variable immunodeficiency (CVI) that were expanded in culture with rIL-2 and Con A. Thus, this second TCR may be composed of two polypeptide chains (gamma gamma'), both of which appear to be the product of the gamma-chain gene. These experiments were done with polyclonal cell populations. Cloned T3+ WT31- cell populations are required to determine whether this TCR contains two gamma polypeptide chains. In contrast, only one polypeptide chain of 56 kDa was immunoprecipitated by the 9D7 anti-P13K mAb from peripheral blood lymphocytes from a patient with mild CVI expanded in culture with rIL-2 and polyclonal activators. Using the same 9D7 anti-P13K mAb and immunoblotting analysis, we identified a 35 kDa gamma-chain polypeptide under reducing conditions expressed on purified L3T4- Lyt2- BALB/c mouse thymocytes. This gamma-chain TCR is disulfide linked and has a molecular mass of 80 kDa under nonreducing conditions.     

Functional T cells in athymic nude mice.

After passage of spleen cells from nu/nu mice over a nylon wool column, concanavalin A-responsive cells can be detected in the presence of 2-mercaptoethanol, and specific cytotoxic T lymphocytes can be generated without exposure to interleukin 2 (IL-2). The spleen cells of the nu/nu mice born of nu/nu parents and nursed by nu/nu mothers had significantly fewer Thy-1+ T cells and a lesser capacity to generate cytotoxic T lymphocytes than did the conventionally bred nu/nu mice. Nonetheless, such cells were clearly present. IL-2 may act to cause these post-thymic T cells to proliferate. Therefore, it seems inappropriate to consider IL-2 as an inducer of the differentiation of T cells in the absence of thymic influence on the basis of the capacity of IL-2 to induce the appearance of a T-lymphocyte population in nu/nu mice.     

A nationwide analysis of clinical outcomes among newborns with esophageal atresia and tracheoesophageal fistulas in the United States

Background

The aim of this study was to examine national outcomes in newborn patients with esophageal atresia and tracheoesophageal fistula (EA/TEF) in the United Sates.

Methods

Kid's Inpatient Database (KID) is designed to identify, track, and analyze national outcomes for hospitalized children in the United States. Inpatient admissions for pediatric patients with EA/TEF for kid's Inpatient Database years 2000, 2003, 2006, and 2009 were analyzed. Patient demographics, socioeconomic measures, disposition, survival and surgical procedures performed were analyzed using standard statistical methods.

Results

A total of 4168 cases were identified with diagnosis of EA/TEF. The overall in-hospital mortality was 9%. Univariate analysis revealed lower survival in patients with associated acute respiratory distress syndrome, ventricular septal defect (VSD), birth weight (BW) < 1500 g, gestational age (GA), time of operation within 24 h of admission, coexisting renal anomaly, imperforate anus, African American race, and lowest economic status. Multivariate logistic regression identified BW < 1500 g (odds ratio [OR] = 4.5, P < 0.001), operation within 24 h (OR = 6.9, P < 0.001), GA <28 wk (OR = 2.2, P < 0.030), and presence of VSD (OR = 3.8, P < 0.001) as independent predictors of in-hospital mortality. Children's general hospital and children's unit in a general hospital were found to have a lower mortality rate compared with not identified as a children's hospital after excluding immediate transfers (P = 0.008).

Conclusions

BW < 1500 g, operation within 24 h, GA < 28 wk, and presence of VSD are the factors that predict higher mortality in EA/TEF population. Despite dealing with more complicated cases, children's general hospital and children's unit in a general hospital were able to achieve a lower mortality rate than not identified as a children's hospital.