Stress injury of the rib in a swimmer

Rib stress injuries are uncommonly reported but have been documented among athletes, most notably rowers. There have only been two prior case reports of rib stress injuries in swimmers, both of which were young females. Magnetic resonance (MR) imaging was either not obtained or the imaging characteristics were incompletely described. We present a case of an isolated third rib stress injury in a collegiate male swimmer diagnosed via MR imaging. We briefly discuss the possible etiologies for rib stress injuries, their MR appearance, as well as their treatment.     

Incidence and costs of severe hypoglycaemia requiring attendance by the emergency medical services in South Central England

Aims The aim was to estimate the incidence of severe hypoglycaemia requiring emergency ambulance assistance, its management and associated costs. Methods A retrospective observational study used routinely collected data for a 1‐year period from December 2009 to November 2010 from the South Central Ambulance Service National Health Service Trust, UK. The main outcome was episodes reported by ambulance personnel and costs were estimated from published data. Results During the 1‐year study period, 398 409 emergency calls were received, of which 4081 (1.02%) were coded as hypoglycaemia. The overall numbers (and annual rate) of hypoglycaemia recorded among people ≥ 15 years with presumed diabetes was 3962 (2.1%), but for those aged 15–35 years was 516 (7.5%) and for those aged ≥ 65 years was 1886 (1.9%). Of those attended, 1441 (35.3%) were taken to hospital. The estimated total cost of initial ambulance attendance and treatment at scene was £553 000; if transport to hospital was necessary, the additional ambulance costs were £223 000 plus emergency department costs of £140 000; and the cost of primary care follow‐up was estimated as £61 000. The average cost per emergency call was £263. The estimated annual cost of emergency calls for severe hypoglycaemia is £13.6m for England. Conclusions Our estimates suggest prevalence of severe hypoglycaemia attended by the emergency services is high in younger age groups and lower for older age groups, although the absolute numbers of severe events in older age groups contribute substantially to the overall costs of providing emergency assistance for hypoglycaemia.     

Familial protein S deficiency with a variant protein S molecule in plasma and platelets

A protein S deficient family presenting a variant protein S molecule in plasma and platelets is described. The propositus, age 20, and two brothers suffered from venous thrombotic disease. The propositus, the only family member studied while taking oral anticoagulants, had a protein S antigen (ag) level of 17% and undetectable activity. As demonstrated by immunoblotting both the propositus and one clinically affected brother (42% ag, 7% activity) presented variant protein S molecules of 65,000 molecular weight (mol wt) while the other clinically affected brother (64% ag, 11% activity) had only protein S with normal electrophoretic mobility of 70,000 mol wt. The mother had normal protein S levels (93% ag, 100% activity) but had both normal and variant protein S molecules and based on her functional protein S data a normal anticoagulant activity of the variant molecule is suggested. One asymptomatic but protein S deficient sister (68% ag, 9% activity) as well as the asymptomatic protein S deficient father (59% ag, 10% activity) had only protein S molecules of 70,000 mol wt. The variant protein S bound to C4b-binding protein in plasma, and differed from normal protein S in carbohydrate content. Platelets of each family member contained the same immunoblotting pattern of normal and variant protein S forms as found in plasma, consistent with the hypothesis that protein S gene expression involves codominant expression of two alleles that is similar in cells that control the synthesis of both platelet and plasma forms of protein S.     

Expression of CD27 and its ligand, CD70, on chronic lymphocytic leukemia B cells

Crosslinking the CD27 antigen on T cells provides a costimulatory signal that, in concert with T-cell receptor crosslinking, can induce T- cell proliferation and cellular immune activation. We find that chronic lymphocytic leukemia (CLL) B cells from most patients coexpress both membrane-bound and soluble CD27, along with its newly identified ligand, CD70. The expression of soluble CD27 may preclude leukemic B cells from stimulating T cells via CD70, thereby potentially impairing their ability to function as effective antigen-presenting cells. We find that leukemic B-cell expression of soluble and membrane-bound CD27 can be downmodulated through a CD40-dependent signal. This signal also induces enhanced expression of CD70 on both normal and leukemic B cells. We find that tumor necrosis factor (TNF)-alpha, or the Th1 cytokine interferon (IFN)-gamma, also can induce downmodulation of CD27, whereas Th2-associated cytokines interleukin-4 (IL-4) or IL-10 can enhance leukemic B-cell expression of this accessory molecule. The modulation of CD27 induced by these conditions is accompanied by reciprocal changes in the expression levels of CD70, suggesting that these accessory molecules may be engaged in reciprocal receptor-ligand downmodulation. Consistent with this, we observe that co-culture of CLL B cells with transfected murine plasmacytoma cells that express human CD70 affects downmodulation of CD27 and enhanced expression of CD70 on leukemic B cells, but does not affect expression of CD27 mRNA. However, we find that CD40-crosslinking, in addition to reducing the level of CD27 protein, also reduces leukemic B-cell expression of CD27 mRNA. This argues that the changes in the expression levels of CD27 following CD40-signaling are not simply due to induced increases in the expression levels of CD70. Finally, we demonstrate that reciprocal changes in expression of CD27 and CD70 may contribute to the enhanced antigen-presenting capacity of CLL B cells after CD40-dependent leukemic B-cell activation. These findings expand the understanding of the regulation of costimulatory molecules important in antigen presentation and also have implications for the immunobiology of and therapy for CLL.     

Glycated haemoglobin predicts progression to diabetes mellitus in Pima Indians with impaired glucose tolerance

Summary Glycated haemoglobin could offer several practical advantages over the OGTT for assessing glucose metabolism. Initial cross-sectional studies (1983–1985) on 381 subjects (mostly Pima Indians) described the relationship between HbA_1c (a specific glycated Hb) and the OGTT. We performed follow-up OGTTs and HbA_1c measurements on 257 of these same subjects 1.6–6.1 years later. Subjects were again grouped according to both the result of the OGTT (normal, IGT or diabetes, by WHO criteria) and HbA_1c result (normal or elevated based on mean ± 1.96 SD of normal). Of 66 subjects with IGT at baseline, 47 (71%) had normal HbA_1c and 19 (29%) had elevated HbA_1c. Twentysix (39%) of these subjects had diabetes at follow-up. Of these subjects with IGT, a significantly greater percentage of subjects with elevated HbA_1c at baseline (68%) showed worsening to diabetes than those with a normal HbA_1c (28%); (chi-square=7.8, df=1, p<0.01). Thus, in subjects with IGT, glycated Hb may be a useful predictor of progression to diabetes.Abbreviations OGTT Oral glucose tolerance test - WHO World Health Organisation - IGT impaired glucose tolerance