Impact of changes in heart rate and stroke volume on the cross sectional flow velocity distribution of diastolic mitral blood flow

The effect of changes in stroke volume on the cross sectional velocity distribution in the mitral orifice during passive mitral inflow was studied in six patients with total atrioventricular block, atrial fibrillation and VVI pacemakers during periods with different heart rates. The time velocity integrals recorded both in the left ventricular outflow tract and at the mitral orifice decreased significantly as the heart rate was increased from 60 to 80 and from 80 to 100 beats per minute. Instantaneous cross sectional flow velocity profiles were constructed by time interpolation of the velocity data from each point in sequentially delayed two dimensional digital ultrasound maps. Each patient had a characteristic cross sectional flow velocity profile in the mitral orifice recorded at the level of the leaflet tips in a four chamber view. The velocity profiles varied between the patients. With increase in heart rate only minimal changes in the flow profiles from individual patients were seen. The maximum velocity through the mitral orifice overestimated the cross sectional mean velocity at the same time by a factor of 1.4–1.9. The maximum time velocity integral overestimated the cross sectional mean by a factor of 1.4–1.8. The observed cross sectional skew varied between patients but did not change significantly with increasing heart rate and decrease in stroke volume.     

Metabolic markers in blood can separate prostate cancer from benign prostatic hyperplasia

Background:

An individualised risk-stratified screening for prostate cancer (PCa) would select the patients who will benefit from further investigations as well as therapy. Current detection methods suffer from low sensitivity and specificity, especially for separating PCa from benign prostatic conditions. We have investigated the use of metabolomics analyses of blood samples for separating PCa patients and controls with benign prostatic hyperplasia (BPH).

Methods:

Blood plasma and serum samples from 29 PCa patient and 21 controls with BPH were analysed by metabolomics analysis using magnetic resonance spectroscopy, mass spectrometry and gas chromatography. Differences in blood metabolic patterns were examined by multivariate and univariate statistics.

Results:

By combining results from different methodological platforms, PCa patients and controls were separated with a sensitivity and specificity of 81.5% and 75.2%, respectively.

Conclusions:

The combined analysis of serum and plasma samples by different metabolomics measurement techniques gave successful discrimination of PCa and controls, and provided metabolic markers and insight into the processes characteristic of PCa. Our results suggest changes in fatty acid (acylcarnitines), choline (glycerophospholipids) and amino acid metabolism (arginine) as markers for PCa compared with BPH.     

Should we educate about the risks of medication overuse headache?

Background

Medication-overuse headache (MOH) is caused by the regular use of medications to treat headache. There has been a lack of research into awareness of MOH. We distributed an electronic survey to undergraduate students and their contacts via social networking sites. Analgesic use, awareness of MOH, perceived change in behaviour following educational intervention about the risks of MOH and preferred terminology for MOH was evaluated.

Findings

485 respondents completed the questionnaire (41% having received healthcare training). 77% were unaware of the possibility of MOH resulting from regular analgesic use for headache. Following education about MOH, 80% stated they would reduce analgesic consumption or seek medical advice. 83% indicated that over the counter analgesia should carry a warning of MOH. The preferred terminology for MOH was painkiller-induced headache.

Conclusions

This study highlights the lack of awareness of MOH. Improved education about MOH and informative packaging of analgesics, highlighting the risks in preferred lay terminology (i.e. painkiller-induced headache), may reduce this iatrogenic morbidity and warrants further evaluation.     

Platelet-derived growth factor promotes polymorphonuclear leukocyte activation

The platelet-derived growth factor (PDGF) has several well defined important biologic activities. Platelet-derived growth factor is the major mitogen in human serum for cells of mesenchymal origins; it is a potent chemoattractant protein for human monocytes, neutrophils, fibroblasts, and smooth muscle cells; and has been implicated in transformation by simian sarcoma virus and perhaps in transformation by other agents as well. In this article, PDGF has been shown to stimulate activation of human peripheral blood neutrophils defined by loss of membrane associated calcium as reflected by loss of chlortetracycline fluorescence, release of superoxide anion and specific granule enzymes, and enhanced neutrophil adherence and aggregation. These responses occurred in a dose-dependent fashion at concentrations of PDGF between 10 ng/mL (0.4 nmol/L) and 40 ng/mL (1.5 nmol/L) and were comparable to effects obtained with optimal concentrations of fMLP and C5a. Degranulation induced by PDGF was selective for secondary (specific) granules and not primary (azurophil) granules. Platelet-derived growth factor thus is ideally suited for a pivotal role in attracting inflammatory cells locally and initiating neutrophil activation at sites of blood vessel injury. Platelet-derived growth factor or a closely related protein also may play an important role in attracting and activating neutrophils in association with inflammatory tumors.     

Pneumocystis carinii pneumonia studied by gallium-67 scanning

The validity and reliability of gallium-67 (Ga-67) scanning for diagnosis and follow-up of Pneumocystis carinii pneumonia (PCP) were assessed in 34 patients thought to have pulmonary complications of acquired immunodeficiency syndrome (AIDS). Overall sensitivity was 94% and specificity 74%. Among patients with normal or equivocal chest radiographs at the time of admission, sensitivity was 86% and specificity 85%. The authors consider Ga-67 scanning a valid and reliable adjunct in the diagnosis of PCP in AIDS patients with respiratory symptoms when the chest radiograph is normal or equivocal.     

Isolated congenital tricuspid valve dysplasia: A rare condition mimicking persistent pulmonary hypertension of the newborn

ABSTRACT Isolated congenital tricuspid valve dysplasia is a rare and potentially lethal congenital heart disease that can be easily confused with persistent pulmonary hypertension of the newborn. We describe a neonate with isolated congenital tricuspid valve dysplasia who did not respond to mechanical ventilation but improved by tolazoline. Clinicians should be aware that the initial fulminant course of this condition may be reversed by reducing the pulmonary vascular resistance, thereby allowing time for spontaneous recovery.     

Digital subtraction angiography of the thoracic aorta

Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.