Carrier extraction circuit

Feedback loop extracts demodulated reference signals from IF input and feeds signal back to demodulator. Since reference signal is extracted directly from carrier, no separate reference need be transmitted. Circuit obtains coherent carrier from balanced or unbalanced four-phase signal of varying characteristics

Clozapine-induced myocarditis

Approved in 1989 for the management of treatment-resistant schizophrenia, Clozapine is a last-line atypical antipsychotic drug used with increasing frequency. In addition to its well-known side effect of agranulocytosis, this drug also carries with it rare but serious adverse cardiovascular risk of myocarditis. We present a patient on Clozapine who was admitted to the cardiology service with chest pain, ST segment elevations and elevated troponin concerning for acute myocardial infarction. Evaluation with imaging revealed decreased left ventricular function, however, no coronary artery disease was present on catheterization; findings consistent with a diagnosis of myocarditis. Subsequent discontinuation of the patient’s Clozapine and initiation of brief supportive medical therapy resulted in full recovery of systolic left ventricular function. Given the potential cardiovascular mortality risk, it is important for physicians on cardiology services caring for psychiatric patients to be aware of the presentation of symptoms, diagnostic findings and management of Clozapine induced myocarditis

Spontaneous coronary artery dissection: a rare diagnosis in a postmenopausal woman

We report a case of a 50-year-old ex-smoker, postmenopausal woman presenting with an acute myocardial infarction caused by a spontaneous coronary artery dissection of a long ‘wrap-around’ left anterior descending coronary artery. After the diagnostic coronary angiography, she was treated medically with subsequent improvement

Percutaneous management of ostial stenosis of the left internal mammary artery graft

A 61-year-old man, who had undergone coronary artery bypass surgery 10 years earlier, presented with a non-ST segment elevation myocardial infarction. He was treated with medical therapy and taken to the Cardiac Catheterization Laboratory. A left heart catheterization demonstrated an ostial stenosis in the left internal mammary artery graft, which was felt to be the culprit lesion. This was successfully repaired with a drug eluting stent. This case is presented as an unusual location for a de novo coronary stenosis. The pathophysiology of these lesions is not well understood

Feasibility of Focused Cardiac Ultrasound in Pre-participation Screening

Objective: Current American Heart Association (AHA) guidelines for pre-participation athletic screening recommend a 12-point history and exam to minimize the risk of sudden cardiac death. We tested the hypothesis that focused cardiac ultrasound (FCU) performed and simultaneously interpreted by a cardiologist using a handheld ultrasound device would be a feasible addition. Methods: We performed pre-participation screening according to AHA recommendations on high school athletes in a multi-purpose room at their school. In addition to the standard 12-point assessment, a cardiologist simultaneously performed and interpreted a FCU on each athlete using a handheld ultrasound. Results: The mean age of the athletes was 16.6 ± 3.4 years; 68% were male. No evidence of left ventricular hypertrophy, cardiomyopathy, bicuspid aortic valve, or aortopathy was identified. Coronary ostia could not be visualized. Echocardiography added 1.35 ± 0.51 minutes to the standard exam. Conclusion: This feasibility study suggests that the addition of handheld echocardiography with real-time interpretation performed by a cardiologist to a standard AHA pre-participation screening adds less than two minutes of time to the assessment. While the study is not as comprehensive as an office based echocardiogram, it can provide valuable information which may be useful in ruling out some of the most common causes of sudden cardiac death in the young athlete or in selecting those who would benefit from further testing

Higher Education in the USA, Student fees, financial aid and access

In 2006 the English higher education system will be facing the introduction of variable - albeit capped - tuition fees, alongside a new system of government financial support for students and a market in institutional bursaries and scholarships. Concerns about the potential impact on different groups of students, and on efforts to widen participation in HE have led to the requirement for institutions to make Access agreements and to commit to certain levels of bursary and outreach support. This report of a study trip conducted in June 2005 looks at the US experience of fees, student support, student debt and the implications for access and admissions. It sets out the federal context then reports from the Illinois Student Financial Aid Commission, and two Illinois universities - one private (De Paul University in Chicago) and one public (University of Illinois, Urbana-Champaign). The US has always had a fee culture and a market driven economy in higher education, that includes private universities. The report describes current trends in rising fees, the shift from grants to loans and long-term student debt in the US, and the implications for access and admissions policies - including sophisticated modelling of student academic profile and financial circumstances of the kind that English institutions may have to consider adopting. The report draws out lessons for England and identifies some key issues facing those working to widen access in both the US and England -including the different expectations of equitable treatment in the two countries, the implications of long-term student debt accrued at increasingly high levels and the need to consider what policy and finance levers are appropriate in directing institutional policy towards access and widening participation

The theophylline‐enoxacin interaction: I. Effect of enoxacin dose size on theophylline disposition

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110004/1/cptclpt1988197.pd

High prevalence of <i>Rickettsia africae</i> variants in <i>Amblyomma variegatum</i> ticks from domestic mammals in rural western Kenya: implications for human health

Tick-borne spotted fever group (SFG) rickettsioses are emerging human diseases caused by obligate intracellular Gram-negative bacteria of the genus Rickettsia. Despite being important causes of systemic febrile illnesses in travelers returning from sub-Saharan Africa, little is known about the reservoir hosts of these pathogens. We conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western Kenya. Of the 100 serum specimens tested from each species of domestic ruminant 43% of goats, 23% of sheep, and 1% of cattle had immunoglobulin G (IgG) antibodies to the SFG rickettsiae. None of these sera were positive for IgG against typhus group rickettsiae. We detected Rickettsia africae–genotype DNA in 92.6% of adult Amblyomma variegatum ticks collected from domestic ruminants, but found no evidence of the pathogen in blood specimens from cattle, goats, or sheep. Sequencing of a subset of 21 rickettsia-positive ticks revealed R. africae variants in 95.2% (20/21) of ticks tested. Our findings show a high prevalence of R. africae variants in A. variegatum ticks in western Kenya, which may represent a low disease risk for humans. This may provide a possible explanation for the lack of African tick-bite fever cases among febrile patients in Kenya