Fracture healing following high energy tibial trauma: Ilizarov versus Taylor Spatial Frame

Introduction

The optimal treatment of high energy tibial fractures remains controversial and a challenging orthopaedic problem. The role of external fixators for all these tibial fractures has been shown to be crucial.

Methods

A five-year consecutive series was reviewed retrospectively, identifying two treatment groups: Ilizarov and Taylor Spatial Frame (TSF; Smith & Nephew, Memphis, TN, US). Fracture healing time was the primary outcome measure.

Results

A total of 112 patients (85 Ilizarov, 37 TSF) were identified for the review with a mean age of 45 years. This was higher in women (57 years) than in men (41 years). There was no significant difference between frame types (p=0.83). The median healing time was 163 days in both groups. There was no significant difference in healing time between smokers and non-smokers (180 vs 165 days respectively, p=0.07), open or closed fractures (p=0.13) or age and healing time (Spearman''s r=0.12, p=0.18). There was no incidence of non-union or re-fracture following frame removal in either group.

Conclusions

Despite the assumption of the rigid construct of the TSF, the median time to union was similar to that of the Ilizarov frame and the TSF therefore can play a significant role in complex tibial fractures.     

Efficacy and safety of adenosine in the treatment of supraventricular tachycardia in infants and children.

One hundred and seventeen episodes of supraventricular tachycardia in 50 children, including 28 infants, were treated with intravenous adenosine. Adenosine was prepared in a sterile solution of 0.9% saline (1 mg/ml) and given in incremental doses of 0.05 mg/kg every two minutes to a maximum of 0.25 mg/kg. Ninety of the 117 episodes were terminated. This included 88 of the 102 episodes of junctional tachycardia (79 of the 92 episodes of atrioventricular reentry tachycardia, seven of the eight episodes of atrioventricular nodal reentry tachycardia, and both of the episodes of long R-P' tachycardia). Only one of four episodes of His bundle tachycardia and one of the eight episodes of ectopic atrial tachycardia were terminated. None of the three episodes of atrial flutter were terminated. Side effects were frequent but mild and included transient complete atrioventricular block (less than 6 s), sinus bradycardia (less than 40 s), ventricular extrasystoles, flushing, nausea, headache, and respiratory disturbance. Reinitiation (within 5 s) of supraventricular tachycardia occurred in 13 of the terminated episodes. Although reinitiation limited its clinical efficacy in some patients, intravenous adenosine offered a safe and efficient method of rapid termination of most episodes of supraventricular tachycardia and in some cases facilitated diagnosis of the mechanism.     

The effects of recombinant-DNA-derived interferons on the growth of myeloid progenitor cells

Interferons (IFNs) have been shown to have significant effects on hematopoietic cell growth. Previous studies defining these effects have utilized mouse and human alpha-, beta-, and gamma-IFN isolated from supernatants of stimulated cells. Despite purification, the possible presence of other lymphokines and soluble factors remains a concern. In this study, the effects of gene-cloned alpha- and gamma-IFN on colony- forming units of granulocyte/macrophage (CFU-GM) progenitors cultured from the peripheral blood of normal volunteers were examined. In addition, blast cell colonies from one patient with acute myelogenous leukemia (AML) were studied. The growth of normal CFU-GM and AML blast cell colonies was inhibited in a dose-dependent manner by gamma- and alpha-IFN. gamma-IFN was ten to 100 times more potent than alpha-IFN in that this species of IFN reduced colony formation by greater than 50% at concentrations of less than 15 antiviral U/mL. The effects of gamma- IFN were neutralized by a monoclonal antibody specific for gamma-IFN. These in vitro studies indicate that human gamma-IFN may be an important modulator of myelopoiesis. Although these data indicate a possible efficacy of gamma-IFN in the treatment of AML, the in vitro results should be considered for their in vivo significance.     

Regulation of human monocyte HLA-DR and CD4 antigen expression, and antigen presentation by 1,25-dihydroxyvitamin D3

1,25-Dihydroxyvitamin D3 (1,25(OH)2-D) has been shown to be a macrophage-derived cytokine, capable of regulating myeloid differentiation and T-cell activation in vitro. Therefore, we examined the effects of 1,25(OH)2-D on the monocyte phenotype and function of human peripheral blood monocytes as an index of its biologic role at an inflammatory site. 1,25(OH)2-D treatment consistently and specifically reduced HLA-DR and CD4 expression by monocytes, while CD14 and class I HLA antigen expression were unaffected. Expression of Fc gamma R I-III on monocytes was variably modulated by 1,25(OH)2-D treatment, but no differences in antibody-dependent cell cytotoxicity (ADCC) were observed, measured using either ADCC or anti-Fc gamma R-antibody expressing hybridomas. In contrast, the ability of monocytes to induce antigen-dependent T-cell proliferation was markedly reduced by 1,25(OH)2-D pretreatment for as little as 6 hours. Addition of interleukin-1 (IL-1), IL-6, or indomethacin did not restore antigen-dependent T-cell proliferation, suggesting that this observation was not secondary to changes in IL-1, IL-6, or PGE2 production induced by 1,25(OH)2-D. These data suggest that 1,25(OH)2-D treatment specifically modulates human monocyte phenotype and function, altering HLA-DR antigen expression and antigen presentation, while leaving lytic function intact. These findings may be relevant to the immunobiologic role of 1,25(OH)2-D.     

Effect of Colesevelam HCl Monotherapy on Lipid Particles in Type 2 Diabetes Mellitus

Purpose

In addition to lowering hemoglobin A1C, colesevelam has been shown to improve the atherogenic lipoprotein profile of subjects with type 2 diabetes mellitus (T2DM) when used in combination with metformin and/or sulfonylureas. A recent study evaluated the effects of colesevelam as antidiabetes monotherapy in adults with T2DM who had inadequate glycemic control (hemoglobin A1C ≥7.5 to ≤9.5 %) with diet and exercise alone; we report here the effects on lipoprotein particle subclasses.

Methods

Subjects were randomized to receive oral colesevelam 3.75 g/day (n?=?176) or placebo (n?=?181) for 24 weeks. Changes in lipoprotein particle subclasses were determined by nuclear magnetic resonance spectroscopy.

Results

At Week 24 with last observation carried forward, colesevelam produced a reduction in total low-density lipoprotein (LDL) particle concentration (baseline: 1,611 nmol/L; least-squares [LS] mean treatment difference: ?143 nmol/L, p?<?0.0001) versus placebo; reductions were also seen in large, small, and very small LDL particle concentrations (all p?<?0.05). There was also a reduction in total very low-density lipoprotein (VLDL) and chylomicron particle concentration (baseline: 88 nmol/L; LS mean treatment difference: ?1 nmol/L, p?=?0.82) that resulted from a lowering in small VLDL particle concentration (baseline: 45 nmol/L; LS mean treatment difference: ?5 nmol/L, p?=?0.03). In addition, with colesevelam there was an increase in total high-density lipoprotein (HDL) particle concentration versus placebo (baseline: 31 μmol/L; LS mean treatment difference: +0.6 μmol/L, p?=?0.20), due to increases in the large (baseline: 5 μmol/L; LS mean treatment difference: +0.5 μmol/L, p?=?0.007) and medium (baseline: 3 μmol/L; LS mean treatment difference: +0.8 μmol/L, p?=?0.02) HDL subclasses.

Conclusions

Colesevelam monotherapy in subjects with T2DM resulted in generally favorable changes in certain lipoprotein subclass profiles compared with placebo.     

A Comparative Study of Three-Year Weight Loss and Outcomes After Laparoscopic Gastric Bypass in Patients with “Yellow Light” Psychological Clearance

The relationship between psychological factors and bariatric surgical outcomes is unclear. While some psychological contraindications to bariatric surgery are described, there is no consensus on preoperative psychological evaluation or on factors that can predict bariatric outcomes. Our aim was to determine whether full or reserved psychological clearance predicts early weight loss or compliance with follow-up. We found no clinically significant differences in short-term weight loss outcomes or in attendance at scheduled follow-up visits between patients receiving full or “green light” clearance versus “yellow light” clearance, meaning clearance with recommendations for ongoing therapy. Further research may identify psychological predictors of success following bariatric surgery and help optimize preoperative evaluation practices.     

B-cell growth factor receptor expression and B-cell growth factor response of leukemic B cell precursors and B lineage lymphoid progenitor cells

The purpose of this study was to analyze the expression of B cell growth factor (BCGF) receptors and to elucidate the biologic effects of biochemically purified natural BCGF at the B cell precursor stage of human B lineage lymphoid differentiation. The specific binding of radioiodinated high-mol-wt BCGF (125I-HMW-BCGF) and low-molecular-wt BCGF (125I-LMW-BCGF) to fresh marrow blasts from B cell precursor acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated BCGF molecules bound per blast ranged from undetectable to 24.3 X 10(3) for HMW-BCGF, and from 11.5 X 10(3) to 457.8 X 10(3) for LMW-BCGF. In 3H-TdR incorporation assays, 75% of cases showed a significant response to LMW-BCGF with a median stimulation index of 9.3. By comparison, only 33% of cases showed a significant response to HMW-BCGF with a median stimulation index of 2.4. Subsequently, B cell precursor colony assays were performed to assess and compare the biologic effects of BCGF on leukemic B lineage lymphoid progenitor cells. Among 28 cases studied, 57% responded to both HMW-BCGF and LMW-BCGF, 21% responded only to LMW-BCGF, and the remaining cases showed no proliferative response to either growth factor. The response patterns of virtually pure populations of FACS- sorted leukemic B cell precursors were essentially identical to the proliferative responses of unsorted leukemic B-cell precursors. Synergistic effects between HMW-BCGF and LMW-BCGF were observed in 80% of the cases that responded to both. The numbers of cell-bound radioiodinated BCGF molecules, the stimulation indices, as well as the number of B cell precursor colonies in BCGF-stimulated cultures showed a marked interpatient variation. Patients with structural chromosomal abnormalities (SCAs) involving 12p11-13 or patients with a Philadelphia chromosome showed a greater HMW-BCGF response at the level of leukemic progenitor cells than did other patients (P = .02). The LMW-BCGF response was significantly greater for patients with SCA than for patients without SCA (P = .04). The response of leukemic progenitor cells to HMW-BCGF or LMW-BCGF did not correlate with sex, age, disease status, FAB morphology, WBC at diagnosis, or immunophenotype. To our knowledge, this study represents the first detailed analyses of BCGF receptor expression and BCGF effects in B cell precursor ALL. The data presented provide direct evidence for the expression of functional receptors for both HMW-BCGF and LMW-BCGF in B cell precursor ALL.     

Utility of selection methods for specialist medical training: A BEME (best evidence medical education) systematic review: BEME guide no. 45

Background: Selection into specialty training is a high-stakes and resource-intensive process. While substantial literature exists on selection into medical schools, and there are individual studies in postgraduate settings, there seems to be paucity of evidence concerning selection systems and the utility of selection tools in postgraduate training environments.

Aim: To explore, analyze and synthesize the evidence related to selection into postgraduate medical specialty training.

Method: Core bibliographic databases including PubMed; Ovid Medline; Embase, CINAHL; ERIC and PsycINFO were searched, and a total of 2640 abstracts were retrieved. After removing duplicates and screening against the inclusion criteria, 202 full papers were coded, of which 116 were included.

Results: Gaps in underlying selection frameworks were illuminated. Frameworks defined by locally derived selection criteria, and heavily weighed on academic parameters seem to be giving way to the evidencing of competency-based selection approaches in some settings.

Regarding selection tools, we found favorable psychometric evidence for multiple mini-interviews, situational judgment tests and clinical problem-solving tests, although the bulk of evidence was mostly limited to the United Kingdom. The evidence around the robustness of curriculum vitae, letters of recommendation and personal statements was equivocal. The findings on the predictors of past performance were limited to academic criteria with paucity of long-term evaluations. The evidence around nonacademic criteria was inadequate to make an informed judgment.

Conclusions: While much has been gained in understanding the utility of individual selection methods, though the evidence around many of them is equivocal, the underlying theoretical and conceptual frameworks for designing holistic and equitable selection systems are yet to be developed.