Delayed calf muscle phosphocreatine recovery after exercise identifies peripheral arterial disease.

OBJECTIVES: In this study we intend to characterize phosphocreatine (PCr) recovery kinetics with phosphorus-31 ((31)P) magnetic resonance spectroscopy in symptomatic peripheral arterial disease (PAD) patients compared with control subjects and determine the diagnostic value and reproducibility of this parameter. BACKGROUND: Due to the inconsistent relationship between flow and function in PAD, novel techniques focused on the end-organ are needed to assess disease severity and measure therapeutic response. METHODS: Fourteen normal subjects (5 men, age 45 +/- 14 years) and 20 patients with mild-to-moderate symptomatic PAD (12 men, age 67 +/- 10 years, mean ankle brachial index 0.62 +/- 0.13) were studied. Subjects exercised one leg to exhaustion while supine in a 1.5-T magnetic resonance scanner using a custom-built plantar flexion device. Surface coil-localized, free induction decay acquisition localized to the mid-calf was used. Each 31P spectrum consisted of 25 signal averages at a repetition time of 550 ms. The PCr recovery time constant was calculated by monoexponential fit of PCr versus time, beginning at exercise completion. RESULTS: Median exercise time was 195.0 s in normal subjects and 162.5 s in PAD patients (p = 0.06). Despite shorter exercise times in patients, the median recovery time constant of PCr was 34.7 s in normal subjects and 91.0 s in PAD patients. Area under the receiver-operating characteristic curve was 0.925 +/- 0.045. Test-retest reliability was excellent. CONCLUSIONS: The PCr recovery time constant is prolonged in patients with symptomatic PAD compared with normal subjects. The method is reproducible and may be useful in the identification of disease. Further study of this parameter's ability to track response to therapy as well as its prognostic capability is warranted.     

Primary cardiac tumours: eighteen years of surgical experience on 21 patients

BACKGROUND: The literature on primary cardiac tumours is relatively limited because of their rare occurrence. OBJECTIVE: To report the authors' experience with primary cardiac tumours at McGill University teaching hospitals, Montreal, Quebec. In addition, four exceedingly rare primary cardiac tumours are presented--three valve myxomas and the seventh reported case of a primary synovial sarcoma. METHODS: Twenty-one patients resected for primary cardiac tumours were retrospectively reviewed in terms of their clinical presentation, surgical treatment, histopathological findings and outcome. Postoperative success was defined by disease-free survival after resection. A survival analysis was performed using the Kaplan-Meier life-table method. RESULTS: The mean age at the time of resection was 45.5 years (range birth to 74 years). The most common clinical presentation in adults was dyspnea (38%) or central nervous system/embolic phenomena (24%), and in the pediatric group, it was hypoxia (50%). All but one of the tumours were visualized using transthoracic echocardiography. Coronary angiography was performed in 11 patients, with a diagnosis of coronary artery disease in five patients (45%), all of whom underwent coronary artery bypass grafting. The surgical approach was uniatrial in 10 patients (48%)--seven (33%) via the left atrium and three (14%) via the right atrium. Eight patients (38%) required a biatrial approach; the remaining three patients (14%) with ventricular tumours required a ventricular approach. Of the 21 cases, 17 were adults and four were pediatric cases. There were 16 myxomas (76%), two rhabdomyomas (10%), one fibroma (5%), one angiosarcoma (5%) and one synovial sarcoma (5%). In adults, myxoma was the most common primary cardiac tumour (88%), whereas rhabdomyoma occurred most frequently in the pediatric population (50%). Three valve myxomas, two involving the mitral valve and one involving the tricuspid valve, were encountered; all underwent conservative leaflet resection and valve repair. The probability of disease-free survival for all patients was 80.7% (95% CI 63.6 to 97.7) at one year, and 75.6% (95% CI 57.0 to 94.3) at both five and 10 years after resection. For adult benign tumours, the probability of disease-free survival was 93% (95% CI 79.4 to 100.0) at one, five and 10 years. There was a total of five deaths. CONCLUSIONS: The results suggest that complete surgical resection of primary cardiac tumours prolongs symptom-free survival and is associated with a low recurrence rate. Benign primary cardiac tumours have an excellent prognosis in the adult population compared with in the pediatric population (93% versus 50% survival, respectively, in the present cohort). Furthermore, conservative leaflet resection with valve repair of valve myxomas, rather than radical excision and valve replacement, should be strongly considered. Early identification and diagnosis of primary cardiac tumours are necessary for expeditious surgical resection if a cure is desired, especially when encountering malignant primary cardiac sarcomas.     

Evaluating imaging and computer-aided detection and diagnosis devices at the FDA

This report summarizes the Joint FDA-MIPS Workshop on Methods for the Evaluation of Imaging and Computer-Assist Devices. The purpose of the workshop was to gather information on the current state of the science and facilitate consensus development on statistical methods and study designs for the evaluation of imaging devices to support US Food and Drug Administration submissions. Additionally, participants expected to identify gaps in knowledge and unmet needs that should be addressed in future research. This summary is intended to document the topics that were discussed at the meeting and disseminate the lessons that have been learned through past studies of imaging and computer-aided detection and diagnosis device performance.     

Illness perceptions among osteoporotic men and women: correlates and gender differences

BackgroundAlthough osteoporosis is a major public concern, little research attention has been paid to evaluating the manner in which osteoporotic patients perceive their illness.The aim of the current study was to examine osteoporotic patients’ cognitive and emotional illness representations and to see, specifically, if any differences could be correlated with gender.MethodsA convenience sample of 102 women and 100 men (mean age 66 years in both groups) who were diagnosed with osteoporosis, and who were attending bone and mineral clinics at four major medical centers in Israel, participated in the study. Participants were interviewed face-to-face at the clinics or in their homes, using an adapted version of the Illness Perceptions Questionnaire (IPQ). Emotional illness representations were assessed using the state anxiety subscale from the State-Trait Personality Inventory (SPTI).ResultsParticipants perceived osteoporosis as a chronic but controllable disease. They perceived the disease as having few symptoms and mild consequences on their lives.ConclusionsOsteoporotic patients maintained a logical cognitive and emotional structure of their illness. Regarding gender differences, findings showed that women were more pessimistic than men regarding most of the illness representations’ dimensions. Gender differences in illness representations suggest women and men may benefit from different intervention programs, tailored according to their unique perceptions.     

The role of the heterochronic microRNA let-7 in the progression of aging

Aging results in reduced tissue homeostasis and declined ability to replace damaged cells by new functional ones. In many tissues, homeostasis and repair are supported by tissue-specific stem cells that induce to generate differentiated cells in accordance with physiological requirements. Heterochronic genes, initially described in worms, specify the timing of fate decisions in each cell type and thus ensure a synchronized program of development throughout the animal. The heterochronic let-7 microRNA plays an important role in development by repressing cell fate regulators to promote stage progression. Recent studies reveal a new role of let-7 which occurs much later in life and regulates aging of several tissues, across species. In this article I review the current knowledge on the fate mechanisms of tissue stem cells during aging that are modulate by let-7, as well as its co-partners and its target genes. I also discuss the therapeutic potential of controlling heterochronic events as a possible treatment for aging‐related disorders. Timing is a clear dimension of organisms' development that may be difficult to witness in aging stages that are not as defined as in embryonic development. Exploring the regulation of stem cell aging by let-7 may ultimately reveal novel timing mechanisms.     

Childhood Pityriasis Rosea

Abstract: Pityriasis rosea (PR) is an acute, self‐limiting papulosquamous disorder of unknown etiology. Published studies of childhood PR are scarce and most are reviews. The aim of this study was to determine the demographic and clinical features of childhood PR.