Dipyridamole-thallium myocardial scanning in the pre-operative assessment of patients undergoing abdominal aortic aneurysmectomy

Dipyridamole thallium scanning (DTS) is an imaging technique with good sensitivity for coronary artery disease (CAD). The purpose of this study was to compare the haemodynamic courses and the correlation between pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) in patients with normal DTS (Group 1: n = 12) with those whose scans demonstrated CAD (Group2: n = 11). Haemodynamic profiles were obtained prior to anaesthesia and at several times during surgery. The haemodynamic courses in both groups were similar with significant decreases in cardiac index, stroke index, and left ventricular stroke work index during aortic cross-clamping compared with values prior to anaesthesia. There were no significant changes in PCWP and CVP throughout the study. The correlations between PCWP and CVP were significant in both groups as were the correlations between the changes in PCWP and the changes in CVP observed at the time of cross-clamping. These correlations all had large standard errors of the estimate, however, making it impossible to predict the PCWP from the CVP with precision. It is concluded that, in a limited study population, an abnormal DTS did not identify patients in whom the PCWP and CVP correlated poorly during abdominal aortic aneurysmectomy.     

Circadian timekeeping during pregnancy: endogenous phase relationships between maternal plasma hormones and the maternal body temperature rhythm in pregnant rhesus monkeys.

Nine pregnant rhesus monkeys maintained in constant low level lighting (5 Lux) from 56-80 days gestation (dGA) onward were studied to assess the presence or absence of circadian maternal body temperature and maternal plasma hormone variations. Maternal arterial blood samples were taken every 4 h in six monkeys (105-120 dGA) for 48-56 h and every 2 h in three monkeys (108-115 dGA) for 60 h. Maternal intraabdominal temperature was recorded continuously. Cosinor analysis was used to determine circadian rhythmicity. Individual endogenous timekeeping was demonstrated by 1) free-running circadian variations in maternal body temperature in all nine animals, 2) consistent internal acrophase relationships between the maternal body temperature and maternal plasma cortisol rhythm, and 3) idiosyncrasy of the temporal relationship of detectable rhythms to the external environment in individual animals. Only one animal had a significant maternal plasma ACTH rhythm, whereas the presence of 24-h variations in the other hormones varied in individual animals. The mean +/- SD acrophase profiles in hours from the temperature acrophase in those animals who showed significant rhythms were 19.7 +/- 0.6 (n = 8) for cortisol, 19.4 +/- 2.4 (n = 6) for dehydroepiandrosterone sulfate, 8.3 +/- 1.1 (n = 6) for progesterone, and 18.9 +/- 1.6 (n = 3) for estradiol. We conclude that 24-h variations in maternal plasma hormones are truly endogenously generated and not passively dependent on the light-dark cycle. The maternal circadian system regulates the 24 h temporal organization of endogenous plasma hormone variations. We hypothesize that rhythms in cortisol, dehydroepiandrosterone sulfate, progesterone, and estradiol during pregnancy are directly or indirectly governed by the maternal hypothalamus via the circadian oscillatory output of the maternal adrenal.     

Evaluation of a hand-held spirometer, the Respiradyne, for the measurement of forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR)

A hand-held spirometer, the Respiradyne (R), was evaluated for the measurement of forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) by comparing it with a Vitalograph spirometer (V) and a Wright's peak flow meter (W) in 70 subjects (normals and patients). The results showed close agreement for FEV1; r = 0.99, R = 0.961V + 0.03 X 10(-5) and FVC; r = 0.99, R = 1.003V-0.044. Results for PEFR using the Respiradyne were generally higher than with the peak flow meter; r = 0.98, R = 1.151W-17.576. The Respiradyne is portable and simple to operate and may be suited to use in a variety of non-laboratory situations.     

Laying the Cytotaxonomic Foundations of a New Model Grass, Brachypodium distachyon (L.) Beauv.

Brachypodium distachyon is a ubiquitous, temperate grass species which is being developed and exploited as an alternative model to rice, in order to gain access to important syntenic regions of the genomes of less tractable relatives such as wheat. As part of this initiative, this paper describes for the first time the cytotaxonomy of members of the polyploid series of this species, and challenges the assumption that the series evolved simply by chromosome doubling. In situ hybridization using genomic DNA probes and rDNA markers uncovers a hybrid origin of several of the polyploid ecotypes, and sheds light upon the complex evolution of this species and its close relatives.     

The measurement of preoperative anxiety.

Preoperative anxiety was assessed using the hospital anxiety and depression (HAD) scale, multiple affect adjective check list (MAACL) and linear analogue anxiety scale (LAAS) in 100 consecutive day case patients undergoing termination of pregnancy. The HAD scale, a recently introduced self assessment scale comprising 7 multiple choice questions, was readily accepted and easily understood by patients. There was a high degree of correlation between the HAD scale and both the MAACL (correlation coefficient 0.74) and the LAAS (correlation coefficient 0.67). There was only a moderate degree of correlation between the HAD scale and the anaesthetist's assessment of anxiety (correlation coefficient 0.46). The HAD scale is a useful method of subjective measurement of preoperative anxiety.