The Cam-type Deformity of the Proximal Femur Arises in Childhood in Response to Vigorous Sporting Activity

Background: The prevalence of a cam-type deformity in athletes and its association with vigorous sports activities during and after the growth period is unknown. Questions/purposes: We therefore compared the prevalence and occurrence of a cam-type deformity by MRI in athletes during childhood and adolescence with an age-matched control group. Patients and Methods: We retrospectively reviewed 72 hips in 37 male basketball players with a mean age of 17.6years (range, 9-25years) and 76 asymptomatic hips of 38 age-matched volunteers who had not participated in sporting activities at a high level. Results: Eleven (15%) of the 72 hips in the athletes were painful and had positive anterior impingement tests on physical examination. Internal rotation of the hip averaged 30.1° (range, 15°-45°) in the control group compared with only 18.9° (range, 0°-45°) in the athletes. The maximum value of the alpha angle throughout the anterosuperior head segment was larger in the athletes (average, 60.5°±9°), compared with the control group (47.4°±4°). These differences became more pronounced after closure of the capital growth plate. Overall, the athletes had a 10-fold increased likelihood of having an alpha angle greater than 55° at least at one measurement position. Conclusions: Our observations suggest a high intensity of sports activity during adolescence is associated with a substantial increase in the risk of cam-type impingement. These patients also may be at increased risk of subsequent development of secondary coxarthrosis. Level of Evidence: Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidenc

The efficacy of mupirocin ointment and chlorhexidine body scrubs in the eradication of nasal carriage of Staphylococcus aureus among patients undergoing long-term hemodialysis

Patients undergoing long-term hemodialysis have a high prevalence of Staphylococcus aureus nasal carriage, which may lead to serious infections. Mupirocin ointment has been used intranasally to eradicate S. aureus carriage in health human volunteers and health care workers. Chlorhexidine, an antiseptic with excellent antistaphylococcal activity, is widely used for handwashing and skin cleansing. METHODS: Anterior nares cultures were obtained from patients older than 18 years who were undergoing long-term hemodialysis. Patients with S. aureus nasal carriage were enrolled in the study. Axillae and groins were cultured. Patients were given mupirocin ointment intranasally twice per day for 7 days and chlorhexidine body scrubs daily for the first 3 days. Follow-up cultures were obtained from anterior nares, axillae, and groins at 1 day, and 1, 4, 8 and 12 weeks after treatment. RESULTS: One day after completion of treatment nasal carriage was eradicated in 83% of patients (15/18). After 12 weeks, 69% of patients (11/16) were free of nasal carriage. CONCLUSIONS: Success rates of eradication were excellent compared with those in other published reports. This simple and effective regimen had no major side effect

Awareness and use of intertrochanteric osteotomies in current clinical practice. An international survey

Current literature shows that intertrochanteric osteotomies can produce excellent results in selected hip disorders in specific groups of patients. However, it appears that this surgical option is considered an historical one that has no role to play in modern practice. In order to examine current awareness of and views on intertrochanteric osteotomies among international hip surgeons, an online survey was carried out. The survey consisted of a set of questions regarding current clinical practice and awareness of osteotomies. The second part of the survey consisted of five clinical cases and sought to elicit views on preoperative radiological investigations and preferred (surgical) treatments. The results of our survey showed that most of these experts believe that intertrochanteric osteotomies should still be performed in selected cases. Only 56% perform intertrochanteric osteotomies themselves and of those, only 11% perform more than five per year. The responses to the cases show that about 30–40% recommend intertrochanteric osteotomies in young symptomatic patients. This survey shows that the role of intertrochanteric osteotomies is declining in clinical practice

Oxygen Consumption Can Regulate the Growth of Tumors, a New Perspective on the Warburg Effect

The unique metabolism of tumors was described many years ago by Otto Warburg, who identified tumor cells with increased glycolysis and decreased mitochondrial activity. However, "aerobic glycolysis" generates fewer ATP per glucose molecule than mitochondrial oxidative phosphorylation, so in terms of energy production, it is unclear how increasing a less efficient process provides tumors with a growth advantage.We carried out a screen for loss of genetic elements in pancreatic tumor cells that accelerated their growth as tumors, and identified mitochondrial ribosomal protein L28 (MRPL28). Knockdown of MRPL28 in these cells decreased mitochondrial activity, and increased glycolysis, but paradoxically, decreased cellular growth in vitro. Following Warburg's observations, this mutation causes decreased mitochondrial function, compensatory increase in glycolysis and accelerated growth in vivo. Likewise, knockdown of either mitochondrial ribosomal protein L12 (MRPL12) or cytochrome oxidase had a similar effect. Conversely, expression of the mitochondrial uncoupling protein 1 (UCP1) increased oxygen consumption and decreased tumor growth. Finally, treatment of tumor bearing animals with dichloroacetate (DCA) increased pyruvate consumption in the mitochondria, increased total oxygen consumption, increased tumor hypoxia and slowed tumor growth.We interpret these findings to show that non-oncogenic genetic changes that alter mitochondrial metabolism can regulate tumor growth through modulation of the consumption of oxygen, which appears to be a rate limiting substrate for tumor proliferation

Interaction of Cationic Proteins and Polypeptides with Biocompatible Cationically-Anchored PEG Brushes

Polyetheylene glycol (PEG) brushes, for instance, physically tethered to a surface via the adsorbing portion of a PEG-containing copolymer, are a popular protein-resistant surface treatment. Though physisorbed brushes might be displaced by competing species, they continue to dominate diagnostic chips and other applications. In this work, we examine the interactions of two cationic species, poly L-lysine (PLL) and lysozyme, with a popular type of PEG brush, formed by the adsorption of a graft copolymer of PLL PEG on negative silica. Here, 20K molecular weight (MW) PLL comprises the main backbone that adsorbs to the silica and the PEG side chains (2K or SK, in different samples) form tethers. This work examines variations in brush heights and densities, still confining the study to brush architectures (near 30% functionalization of the PLL by PEG side chains) that completely prevent the adsorption of blood proteins such as fibrinogen and albumin. It is found that lysozyme adsorbs to interfaces passivated with these PLL PEG copolymers in amounts that increase with the amount of PEG in the brush. This suggests attractions between the PEG tethers and lysozyme itself. When PLL PEG brushes are challenged by homopolymer PLL (a random coil at the physiological pH studied here), the PLL PEG is almost completely displaced from the silica substrate. The rapid displacement kinetics (with complete loss of protein repellence) for all brush architectures suggest the absence of a steric barrier against PLL penetration of the PEG brush. A small overshoot in surface coverage prior to the displacement of the PLL PEG chains demonstrates the adsorption of PLL on regions of silica at the base of the brush prior to chain displacement, further arguing for the accessibility of the substrate despite the presence of the brush. Differences between the interactions of lysozyme or PLL with the brush suggest an important role of the globular nature of folded proteins compared with random coil polypeptides in protein brush interactions and brush penetration. The results emphasize the technological challenge of retaining seemingly robust brushes adsorbed to interfaces, and eliminating protein adhesion from the brush itself