Aerobic or Resistance Exercise, or Both, in Dieting Obese Older Adults.

BACKGROUND: Obesity causes frailty in older adults; however, weight loss might accelerate age-related loss of muscle and bone mass and resultant sarcopenia and osteopenia. METHODS: In this clinical trial involving 160 obese older adults, we evaluated the effectiveness of several exercise modes in reversing frailty and preventing reduction in muscle and bone mass induced by weight loss. Participants were randomly assigned to a weight-management program plus one of three exercise programs - aerobic training, resistance training, or combined aerobic and resistance training - or to a control group (no weight-management or exercise program). The primary outcome was the change in Physical Performance Test score from baseline to 6 months (scores range from 0 to 36 points; higher scores indicate better performance). Secondary outcomes included changes in other frailty measures, body composition, bone mineral density, and physical functions. RESULTS: A total of 141 participants completed the study. The Physical Performance Test score increased more in the combination group than in the aerobic and resistance groups (27.9 to 33.4 points [21% increase] vs. 29.3 to 33.2 points [14% increase] and 28.8 to 32.7 points [14% increase], respectively; P=0.01 and P=0.02 after Bonferroni correction); the scores increased more in all exercise groups than in the control group (P<0.001 for between-group comparisons). Peak oxygen consumption (milliliters per kilogram of body weight per minute) increased more in the combination and aerobic groups (17.2 to 20.3 [17% increase] and 17.6 to 20.9 [18% increase], respectively) than in the resistance group (17.0 to 18.3 [8% increase]) (P<0.001 for both comparisons). Strength increased more in the combination and resistance groups (272 to 320 kg [18% increase] and 288 to 337 kg [19% increase], respectively) than in the aerobic group (265 to 270 kg [4% increase]) (P<0.001 for both comparisons). Body weight decreased by 9% in all exercise groups but did not change significantly in the control group. Lean mass decreased less in the combination and resistance groups than in the aerobic group (56.5 to 54.8 kg [3% decrease] and 58.1 to 57.1 kg [2% decrease], respectively, vs. 55.0 to 52.3 kg [5% decrease]), as did bone mineral density at the total hip (grams per square centimeter; 1.010 to 0.996 [1% decrease] and 1.047 to 1.041 [0.5% decrease], respectively, vs. 1.018 to 0.991 [3% decrease]) (P<0.05 for all comparisons). Exercise-related adverse events included musculoskeletal injuries. CONCLUSIONS: Of the methods tested, weight loss plus combined aerobic and resistance exercise was the most effective in improving functional status of obese older adults. (Funded by the National Institutes of Health; LITOE ClinicalTrials.gov number, NCT01065636 .).

Documented vancomycin-induced severe immune-mediated thrombocytopaenia.

A 69-year-old man developed Propionibacterium acnes left knee hardware infection after suffering from an infected ingrown toenail. The hardware was removed and he was treated with intravenous vancomycin. Ten days after initiation of vancomycin, he developed severe thrombocytopaenia, epistaxis and petechiae. Vancomycin was discontinued, and platelets rapidly recovered. Serum vancomycin IgG were positive. Patient completed a 6-week course of ceftriaxone with no further complications.

Hepatocyte growth factor/scatter factor promotes retinal angiogenesis through increased urokinase expression.

PURPOSE: The purpose of this study was to determine the role of hepatocyte growth factor (HGF) and c-Met in the initiation and development of retinal neovascularization and to determine whether inhibition of this system can suppress the extent of angiogenesis in an animal model. METHODS: Retinal tissues from animals with oxygen-induced neovascularization were analyzed for HGF and c-Met expression and localization. The effect of HGF on the migratory and invasive behavior of isolated retinal endothelial cells was quantitated, and the role of the extracellular proteinase urokinase in facilitating this process was determined. Mice were treated with intraocular injections of anti-c-Met antibody, and the extent of neovascularization was quantitated. RESULTS: HGF and c-Met were upregulated in the retinas of mice with hypoxia-induced retinal neovascularization. HGF was active, as evidenced by the increased presence of the phosphorylated form of c-Met in the tissues. c-Met was localized to various cell types in the retina, including vascular cells, and HGF was produced by cells in the ganglion and inner nuclear layers. HGF stimulated the secretion of urokinase and its receptor, uPAR, in isolated retinal endothelial cells. HGF increased the migratory and invasive capacity of these cells, which could be inhibited by the disruption of urokinase/uPAR interactions with the A6 peptide. Inhibition of c-Met activation in vivo resulted in a 70% decrease in retinal angiogenesis and a 40% decrease in urokinase activity in the retina. CONCLUSIONS: These studies suggest that HGF may play an important role in the initial stages of retinal angiogenesis by stimulating a migratory phenotype in endothelial cells mediated by increased urokinase activity.

Lessons learned from a study-group pilot program for medical students perceived to be 'at risk'.

BACKGROUND: At the University of New Mexico School of Medicine (UNM-SOM) we have noticed that some first year medical students have difficulty accurately assessing their academic skills and are often afraid to seek help. This leads to marginal performance and sometimes even failure. Therefore, we developed a preemptive intervention using peer-led study groups based on the personalized System of Instruction (PSI). AIM: The goal of this pilot study was to evaluate this approach for assisting students, interms of student success, and cast benefit. METHODS: Thirteen first-year medical students considered to be 'at risk' of academic difficulty took part in a six-month pilot intervention. They participated in structured study groups that were facilitated by upper-level medical students. The groups met twice weekly for up to two hours each time. The at-risk students took short multiple-choice quizzes and discussed major concepts. If students did not achieve 80% or better on the quizzes, they were required to take a second quiz to demonstrate mastery. Summative exam scores from four groups of students were compared: those with Medical College Admission Test (MCAT) scores <25, who received the study group intervention; their classmates with MCAT scores >25 who did not receive the intervention; and two matched groups from the previous year, none of whom had access to the structured study groups. RESULTS: No significant differences in exam scores were seen between the group who received the intervention and the matched group who did not. CONCLUSIONS: Despite this result, we learned several useful lessons about study groups and interactions between first-year and upper-level medical students: (1) Students perceived participation in the study groups as a good learning strategy, but preferred participation not be mandated. It may be preferable to train and encourage students to run their own study groups. (2) Both students and proctors acknowledged interpersonal benefits from the program but, as these benefits can be achieved by other means, an expensive proctor-based program is not, we believe, the best use of academic support resources. (3) Focus in the study groups was on content for the quizzes, but more attention to how-to-learn strategies may have had greater impact.

Near death by milk of magnesia.

We report a case of hypermagnesemia associated with the use of milk of magnesia in a male patient with end-stage renal disease. After experiencing nausea and vomiting, he developed severe bradycardia and then asystole. Resuscitation efforts were successful; however, he developed atrial fibrillation with severe widening of the QRS and diffuse ST elevation, hypothermia, hypotension and apnoea requiring intubation. Initial diagnoses included ST-elevation myocardial infarction, cardiogenic and/or septic shock and hyperkalaemia. However, serum magnesium was later found to be >4.1 mmol/L (equivalent to >10 mg/dL). He underwent haemodialysis (HD) to remove serum magnesium with remarkable overall improvement. Severe hypermagnesemia can manifest with severe bradycardia and asystole, shock, hypothermia and respiratory failure and can mimic acute coronary syndromes complicated with cardiogenic shock or septic shock. Therefore, clinicians should be aware of this life-threatening condition in patients with significant renal dysfunction. Timely treatment with HD is highly effective and lifesaving.

CD36 mediates endothelial dysfunction downstream of circulating factors induced by O3 exposure.

Inhaled pollutants induce the release of vasoactive factors into the systemic circulation, but little information is available regarding the nature of these factors or their receptors. The pattern recognition receptor CD36 interacts with many damage-related circulating molecules, leading to activation of endothelial cells and promoting vascular inflammation; therefore, we hypothesized that CD36 plays a pivotal role in mediating cross talk between inhaled ozone (O3)-induced circulating factors and systemic vascular dysfunction. O3 exposure (1 ppm × 4h) induced lung inflammation in wild-type (WT) mice, which was absent in the CD36 deficient (CD36(-/-)) mice. Acetylcholine (ACh)-evoked vasorelaxation was impaired in isolated aortas from O3-exposed WT mice but not in vessels from CD36(-/-) mice. To delineate whether vascular impairments were caused by lung inflammation or CD36-mediated generation of circulating factors, naïve aortas were treated with diluted serum from control or O3-exposed WT mice, which recapitulated the impairments of vasorelaxation observed after inhalation exposures. Aortas from CD36(-/-) mice were insensitive to the effects of O3-induced circulating factors, with robust vasorelaxation responses in the presence of serum from O3-exposed WT mice. Lung inflammation was not a requirement for production of circulating vasoactive factors, as serum from O3-exposed CD36(-/-) mice could inhibit vasorelaxation in naïve WT aortas. These results suggest that O3 inhalation induces the release of circulating bioactive factors capable of impairing vasorelaxation to ACh via a CD36-dependent signaling mechanism. Although lung inflammatory and systemic vascular effects were both dependent on CD36, the presence of circulating factors appears to be independent of CD36 and inflammatory responses.