Purpose of review The measurement of cardiac output in the critically ill constitutes a vital part in the management of these patients. Minimally invasive techniques are gaining popularity as they allow continuous cardiac output monitoring while avoiding the risks associated with pulmonary artery catheterization. This article focuses on some of the commonly used minimally invasive devices that rely on pulse contour waveform analysis. Recent findings The current studies in the literature that assess the validity and the clinical applications of calibrated and noncalibrated arterial waveform derived cardiac output devices are discussed. Summary The minimally invasive cardiac output monitoring devices available differ in their methodology and application. Currently there is conflicting evidence as to the accuracy of some of these systems and further investigation into their clinical application is required.

Background. Two cases of invasive Haemophilus influenzae type b (Hib) infection were reported in immunized children in a day nursery within 1 week. Both cases were younger than 18 months of age, cared for in the same room. We aimed to characterize carriage of Hib and response to eradication therapy in this setting. Methods. Ninety-four children were enrolled in the nursery, cared for by 21 staff in 4 rooms, divided by age. Two children of a part time teacher also attended. Oropharyngeal swabs were taken to detect Hib carriage before introduction of rifampin prophylaxis (20 mg/kg/day for 4 days). A questionnaire addressing risk factors for colonization was administered to parents and staff. Carriage was reassessed in children and carers from the same room as the index cases 1 month later. Results. Eighty-nine children and all 21 staff were swabbed. Two additional Hib carriers, 1 child and 1 staff member, were identified from the same room as the cases. These isolates appeared identical with those causing invasive disease. Given the small numbers no clear risk factors for carriage could be confirmed. Compliance with rifampin prophylaxis was 97.4%. One month later no carriers were found among the 7 children and 3 staff tested from the room in which the cases were originally identified. Conclusions. Although immunization against Hib has resulted in a reduction in the incidence of this disease in the UK, individual protection cannot be assumed to be infallible. The importance of timely chemoprophylaxis of close contacts of a child with invasive Hib disease is reinforced.

Conventional MRI systems rely on large magnets to generate a field that is both strong and extremely uniform. This field is usually produced by a heavy permanent magnet or a cryogenically cooled superconductor. An alternative approach, called prepolarized MRI (PMRI), employs two separate fields produced by two different magnets. A strong and inhomogeneous magnetic field is used to polarize the sample. After polarization, a weak magnetic field is used for readout. These fields can be produced by two separate resistive electromagnets that cost significantly less than a single permanent or superconducting magnet. At Stanford, the authors are constructing a PMRI prototype scanner suitable for imaging human extremities roughly 20 cm in diameter. With this system the authors hope to demonstrate comparable image quality to MRI with reduced system cost. The authors' initial work on low-frequency reception indicates that it will be possible to obtain comparable image signal-to-noise ratio to an MRI scanner operating at the same polarizing field strength. To reduce the capital cost of the system, the authors use resistive electromagnets. Here the authors discuss the full development of the readout magnet including important design considerations, shimming, and field plots. These encouraging results are an important step toward evaluating the cost effectiveness of PMRI.

A clinical trial testing the safety and immunogenicity of a newly developed human diploid cell rabies vaccine (Lyssavac-HDC) was conducted on subjects at three colleges of verterinary medicine in the United States. Lyssavac-HDC is a sterile lyophilized vaccine containing no antibiotics or preservatives and is administered intramuscularly as a 0.5 ml dose of vaccine containing at least 2.5 IU of rabies inactivated antigen per dose. Subjects were given either a three dose pre-exposure series (days 0, 7, and 28), followed by one booster dose of vaccine (day 360); or a five dose simulated post-exposure series of injections (days 0, 3, 7, 14, and 28). All subjects in the post-exposure and pre-exposure groups possessed adequate levels of rabies neutralizing antibody (≥5) when tested on day 14 and day 28, respectively. Subjects in the pre-exposure group demonstrated a vigorous anamnestic response after the administration of one booster dose of vaccine on day 360. The type and severity of local and systemic reactions observed were comparable to other primary cell culture rabies vaccines. Significantly, there were no type III hypersensitivity reactions reported in subjects previously immunized with Lyssavac-HDC after the administration of a booster dose of vaccine on day 360. Published by Elsevier Science Ltd.

Fasting serum high-density lipoprotein (HDL) cholesterol, other lipid concentrations and related characteristics have been measured in 87% of 261 residents aged over 5 years on the small isolated island of Salt Cay, Turks and Caicos Isles. Only one subject, a hypertensive woman, had a major electrocardiographic Q wave abnormality, and none of the islanders had clinical coronary heart disease. These findings, together with local clinical experience indicated a low incidence of coronary heart disease in this community. Adult mean concentrations of HDL cholesterol (1.6 mmol/l) and serum total triglyceride (0.81 mmol/l) were relatively high and low respectively compared with those of men and women in North American communities. Unlike findings in North America, there was no significant sex difference in HDL cholesterol concentration apparent in adulthood and this was not explained by sex differences in alcohol consumption (positively correlated with HDL cholesterol in both sexes) or adiposity (negatively correlated with HDL cholesterol in men only). Residents who were recovering from an epidemic of mild upper respiratory infection had on average a 9% reduction in HDL cholesterol concentration compared with the remainder of the community. The lipoprotein lipid pattern in these people is consistent with a low cardiovascular risk status, and might account for the apparent absence of coronary heart disease on the island.

AbstractFür die Cyclohexanderivate (I) sowie verschiedene ähnliche Verbindungen werden anhand von NMR‐Untersuchungen die Konformationen diskutiert.

John Docker, Australian Cultural Elites: Intellectual Traditions in Sydney and Melbourne, Angus and Robertson, Sydney, 1974, pp. xii + 182. $5.95, paper.