Risk stratification and prevention of sudden death in hypertrophic cardiomyopathy

Sudden unexpected death, often occurring in young, asymptomatic patients, is the most devastating facet of the natural history of hypertrophic cardiomyopathy, and appears to be the consequence of primary ventricular tachyarrhythmias arising in an electrically unstable myocardial substrate characterized by disorganized cellular architecture, ischemia, cell death, and replacement scarring. Although precise identification of all hypertrophic cardiomyopathy patients at high risk for a catastrophic event is a clinical challenge, effective treatment strategies for the prevention of sudden death with the implantable cardioverter-defibrillator are now available.     

Secretoglobins SCGB3A1 and SCGB3A2 define secretory cell subsets in mouse and human airways

Clara cell secretory protein (CCSP) is expressed abundantly within the conducting airway epithelium and is thought to have immunoregulatory functions. Differences in the localization of CCSP between mouse and human airways led us to hypothesize that functional homologues of CCSP may compensate for the lack of CCSP expression in proximal airway locations. We previously identified an expressed sequence tag (W82219) whose expression is induced within Clara cells of CCSP knockout mice. Expressed sequence tag W82219 is distantly related to CCSP and represents a member of a new subfamily of secretoglobins (MmSCGB3A2). Another member of the mouse SCGB3 family (MmSCGB3A1) as well as human orthologues (HsSCGB3A1 and HsSCGB3A2) that possess structural homology to CCSP were identified, suggesting they may share common functional properties. SCGB3A1 messenger RNA localizes to a subset of SCGB3A2-expressing cells within bronchi of both mouse and neonatal human lungs. CCSP, SCGB3A1, and SCGB3A2 were decreased in airways of neonates with bronchopulmonary dysplasia and in mice after airway injury. We conclude that secretory cells of the conducting airway epithelium express distinct members of the secretoglobin family in a partially overlapping fashion. Altered expression of secretoglobins in airway disease may contribute to immunoregulatory perturbations commonly seen in chronic airway disease.     

Optical imaging of intrinsic signals in somatosensory cortex

The experiments address the problem of bimanual coordination in a familiar task of everyday life. A goal-directed drawer-pulling task, with asymmetrical assignments among hands, was analyzed with the objective to detect discrete kinematic events ('anchors') that potentially could serve in proper goal synchronization. The left hand reached out for the drawer and opened it while the right hand performed a prehension movement to pick up a peg from the drawer. The task was smoothly performed, independently of vision. Typically, trajectories and velocity profiles of the leading pull-hand were more stereotypical than the more variable ones of the pick-hand. The pull-hand had a large velocity peak during reaching, followed by a small peak during pulling. Velocity profiles of the pick-hand were not bell-shaped and exhibited one or two broad waves, often with an irregular and probing evolution. Velocity profiles of both hands were aligned with the first or the second velocity peak of the leading pull-hand. In the majority of cases, temporal associations of events in the kinematics of the two limbs could thus be identified, which could serve to synchronize the hands at the goal. The nearly straight biphasic reach-and-pull trajectory of the leading hand contrasted with the more curved trajectory of the right pick-hand whereas, in the same unimanual action, the latter trajectories were quasi-rectilinear. Changing constraints (no vision, cutaneous anesthesia of pulling fingers) could change the coordination pattern. We argue that bimanual coordination relies on two interacting mechanisms: (1) feedforward control on the basis of sensorimotor memory; (2) temporal adjustments during the evolving bimanual synergy. Multiple strategies, imposed by the leading pull-hand, appeared to be responsible for feedback-induced corrections in the pick-hand and were found to contribute to the goal-invariance and to the principle of motor equivalence.     

Hepatic tumor detection: MR imaging and conventional US versus pulse-inversion harmonic US of NC100100 during its reticuloendothelial system-specific phase

PURPOSE: To compare conventional ultrasonography (US) and magnetic resonance (MR) imaging with contrast agent-enhanced US for detection of VX-2 liver tumors in rabbits. MATERIALS AND METHODS: Conventional gray-scale liver US was performed in 65 rabbits, 38 of which had VX-2 hepatic tumor implants. Twenty minutes after contrast agent injection, gray-scale pulse-inversion harmonic US images of the liver-specific phase were obtained. Following sacrifice of the animals, T1- and T2-weighted MR imaging was performed at 4-mm intervals. Pathologic analysis was performed as the reference standard. The capability of each imaging modality to correctly depict tumor presence or absence and the number of tumors was compared. RESULTS: Conventional US correctly depicted the presence or absence of tumors in 54 rabbits, for an accuracy of 83%, sensitivity of 71%, and specificity of 100%. With contrast-enhanced US, accuracy increased to 92% (60 correct cases); sensitivity, to 87%; and specificity, to 100%. MR imaging facilitated 56 correct diagnoses, for an accuracy of 86%, sensitivity of 82%, and specificity of 93%. There was a marginally significant difference between US with and US without contrast agent (P =.07) but not between MR imaging and contrast-enhanced US (P > or = .34). When the numbers of correctly detected tumors were compared, contrast-enhanced US performed significantly better than MR imaging (P =.02) and conventional US (P =.04). CONCLUSION: There was no significant difference between contrast-enhanced US and MR imaging in the detection of hepatic tumors, whereas contrast-enhanced US had the highest accuracy (92%) of the three modalities studied.     

Gender verification of female Olympic athletes

Gender verification of female athletes has long been criticized by geneticists, endocrinologists, and others in the medical community. Problems include invalid screening tests, failure to understand the problems of intersex, the discriminatory singling out of women based only on laboratory results, and the stigmatization and emotional trauma experienced by individuals screened positive. Genuine sex-impostors have not been uncovered by laboratory-based genetic testing; however, gender verification procedures have resulted in substantial harm to a number of women athletes born with relatively rare genetic abnormalities. Individuals with sex-related genetic abnormalities raised as females have no unfair physical advantage and should not be excluded or stigmatized, including those with 5-alpha-steroid-reductase deficiency, partial or complete androgen insensitivity, and chromosomal mosaicism. In 1990, the International Amateur Athletics Federation (IAAF) called for ending genetic screening of female athletes and in 1992 adopted an approach designed to prevent only male impostors from competing. The IAAF recommended that the "medical delegate" have the ultimate authority in all medical matters, including the authority to arrange for the determination of the gender of the competitor if that approach is judged necessary. The new policy advocated by the IAAF, and conditionally adopted by the International Olympic Committee, protects the rights and privacy of athletes while safeguarding fairness of competition, and the American Medical Association recommends that it become the permanent approach.     

Influence of peak VO2 and muscle fiber type on the efficiency of moderate exercise

PURPOSE: The purpose of this study was to determine if %Type I fibers and/or aerobic fitness (as peak .VO(2)) would predict Delta efficiency (DeltaEff) and Delta.VO(2)/Deltawork rate (WR) for moderate (below lactate threshold 0.05). CONCLUSION: These results suggest that aerobic fitness affects the energetic response to changes in power output during moderate exercise, such that the more aerobically fit a subject, the greater the increase in oxygen cost (.VO(2)) (reduced efficiency) as work rate increases. Further, Delta.VO(2)/DeltaWR reflects the inverse of DeltaEff for moderate-intensity exercise in healthy fed subjects.     

The future of catheter-based angiography: implications for the vascular interventionalist

Based on the assumptions mentioned previously, the author makes the following predictions regarding catheter-based angiography and related procedures: 1. Most diagnostic angiography will be performed with noninvasive methods. In the peripheral circulation. MRA will be the predominant method, with CTA having an important role in aortic imaging and coronary imaging. MRA will have increased use for elective diagnosis and in clinical emergencies. 2. Catheter-based angiography will have an important role as an adjunct or preliminary procedure related to interventions. This is significant for planning catheter development and functionality of future angiographic equipment. 3. The need for angiographic equipment will continue to grow despite this decrease in diagnostic application, as a result of increase in interventional therapy. This increase in therapy will be a result of a variety of factors, including aging population, early diagnosis, and increasing acceptance of less invasive therapy. 4. Interventionists should be considering and planning for vascular imaging devices--MRA, CTA, and US--to be included as part of the interventional sections and the workload. 5. Cardiovascular imaging should be a clinical imaging specialty, with patient interaction at the time of imaging. 6. These changes should be embraced by vascular interventionalists, who should incorporate these tools into their clinical practice. 7. The changes, if they occur as predicted, will create significant problems in training skilled interventionists who will not have the foundation of diagnostic angiography on which to build complex endovascular skills.     

Risk factors for deep vein thrombosis in short-haul cockpit crews: a prospective study

BACKGROUND: Venous thrombosis is a concern receiving international attention, especially for passengers traveling on long distance flights. However, there are no data on the effect on cockpit crew of multiple short duration flights. METHODS: Cockpit crew flew two or more internal flights per day. At sign on, 15 ml of blood was venesected from the subjects; at sign off, 20 ml of blood was venesected. All flights originated and terminated at Johannesburg Airport. A full blood count, differential, and D-dimer levels were determined. All participants completed detailed questionnaires stating their ages, alcohol consumption 24 h prior to flight duty, the amount of liquid consumed during flying time, the number of times they went to the toilet, and the amount of time spent sitting during flights. RESULTS: Blood tests on 27 cockpit crew were performed. D-dimers were reduced from 163 ng x ml(-1) to 133 ng x ml(-1) (p = 0.03). Hemoglobin levels dropped from 16.0 g x dl(-1) to 15.8 g x dl(-1) (p = 0.004). Hematocrit levels decreased from 47.2 ml x 100 ml(-1) to 46.9 ml x 100 ml(-1) (p = 0.04). Platelets increased from 221 x 10(9) x L(-1) to 241 x 10(9) x L(-1) (p = 0.001). White cell counts increased from 6.4 x 10(9) x L(-1) to 7.01 x 10(9) x L(-1) (p = 0.0063). Correlation analysis was performed between blood test results and the parameters of the questionnaire. No correlation was found between any of the parameters and the blood results. CONCLUSION: There is no evidence of sub-clinical thrombotic events in this group of subjects. Cockpit crew who fly multiple short duration flights do not suffer sub-clinical thrombotic events as evidenced by an absence of increased D-dimers.     

Treatment and outcome of patients with intracystic papillary carcinoma of the breast

BACKGROUND: Intracystic papillary carcinoma (IPC) of the breast is a rare form of noninvasive breast cancer. An appreciation of associated pathology with IPC may be critical in surgical decision-making. METHODS: The medical records of all patients with IPC treated between 1985 and 2001 were retrospectively reviewed. Three patient groups were identified according to the pathologic features of the primary tumor: IPC alone, IPC with associated ductal carcinoma in situ (DCIS), and IPC with associated invasion with or without DCIS. Types of treatment and outcomes were compared between groups. RESULTS: Forty patients were treated for IPC during the study period. Fourteen had pure IPC, 13 had IPC with DCIS, and 13 had IPC with invasion. The incidence of recurrence and the likelihood of dying of IPC did not differ between the three groups regardless of the type of surgery (mastectomy or segmental mastectomy) performed and whether radiation therapy was administered. The disease-specific survival rate was 100%. CONCLUSIONS: When IPC is identified, it is frequently associated with DCIS and or invasion. Standard therapy should be based on associated pathology. The role of radiation therapy in pure IPC remains to be determined.