Colloid volume loading does not mitigate decreases in central blood volume during simulated haemorrhage while heat stressed.

Heat stress results in profound reductions in the capacity to withstand a simulated haemorrhagic challenge; however, this capacity is normalized if the individual is volume loaded prior to the challenge. The present study tested the hypothesis that volume loading during passive heat stress attenuates the reduction in regional blood volumes during a simulated haemorrhagic challenge imposed via lower-body negative pressure (LBNP). Seven subjects underwent 30 mmHg LBNP while normothermic, during passive heat stress (increased internal temperature ∼1◦C), and while continuing to be heated after intravenous colloid volume loading (11 ml kg⁻¹).

Diagnostic evaluation of three cardiac software packages using a consecutive group of patients.

Purpose: The aim of this study was to compare the diagnostic performance of the three software packages 4DMSPECT (4DM), Emory Cardiac Toolbox (ECTb), and Cedars Quantitative Perfusion SPECT (QPS) for quantification of myocardial perfusion scintigram (MPS) using a large group of consecutive patients.

Methods: We studied 1,052 consecutive patients who underwent 2-day stress/rest 99mTc-sestamibi MPS studies. The reference/gold-standard classifications for the MPS studies were obtained from three physicians, with more than 25 years each of experience in nuclear cardiology, who re-evaluated all MPS images.

Atrial Natriuretic Peptide and Acute Changes in Central Blood Volume by Hyperthermia in Healthy Humans.

Background: Hyperthermia induces vasodilatation that reduces central blood volume (CBV), central venous pressure (CVP) and mean arterial pressure (MAP). Inhibition of atrial natriuretic peptide (ANP) could be a relevant homeostatic defense mechanism during hyperthermia with a decrease in CBV. The present study evaluated how changes in plasma ANP reflect the changes in CBV during hyperthermia.

Use of neural networks to improve quality control of interpretations in myocardial perfusion imaging.

Background: The aim of this study was to explore the feasibility of using a technique based on artificial neural networks for quality assurance of image reporting. The networks were used to identify potentially suboptimal or erroneous interpretations of myocardial perfusion scintigrams (MPS).

Methods: Reversible perfusion defects (ischaemia) in each of five myocardial regions, as interpreted by one experienced nuclear medicine physician during his daily routine of clinical reporting, were assessed by artificial neural networks in 316 consecutive patients undergoing stress/rest 99mTc-sestamibi myocardial perfusion scintigraphy.

EANM/ESC guidelines for radionuclide imaging of cardiac function.

Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes, LV regional function, LV diastolic function, reports and image display and reference values from the literature of RVEF, LVEF and LV volumes.

Effects of passive heating on central blood volume and ventricular dimensions in humans.

Mixed findings regarding the effects of whole-body heat stress on central blood volume have been reported. This study evaluated the hypothesis that heat stress reduces central blood volume and alters blood volume distribution. Ten healthy experimental and seven healthy time control (i.

The role of SPECT-CT in the lymphoscintigraphic identification of sentinel nodes in patients with oral cancer.

Conclusion: SPECT-CT may improve the localization of sentinel nodes (SNs) in patients with oral squamous cell carcinoma (OSCC). Compared with planar lymphoscintigraphy SPECT-CT detected more SNs and provided additional anatomical and spatial information about their localization. New generation SPECT with higher resolution CT scanners are expected to provide more accurate information about the localization of SNs.

Continuous methimazole therapy and its effect on the cure rate of hyperthyroidism using radioactive iodine: an evaluation by a randomized trial.

Background: A randomized clinical trial was performed to clarify whether continuous use of methimazole (MTZ) during radioiodine ((131)I) therapy influences the final outcome of this therapy.

Design: Consecutive patients with Graves' disease (n = 30) or a toxic nodular goiter (n = 45) were rendered euthyroid by MTZ and randomized to stop MTZ 8 d before (131)I (-MTZ; n = 36) or to continue MTZ until 4 wk after (131)I (+MTZ; n = 39). Calculation of the (131)I activity included an assessment of the (131)I half-life and the thyroid volume.

Total zinc absorption in young women, but not fractional zinc absorption, differs between vegetarian and meat-based diets with equal phytic acid content.

Zn bioavailability is often lower in vegetarian diets mainly due to low Zn and high phytic acid contents. The objective of the present study was to determine the fractional and total absorption of Zn from a vegetarian diet in comparison with meat diets with equal concentrations of phytic acid. A randomized cross-over design, comprising three whole-day diet periods of 5 d each, with a vegetarian diet or diets containing Polish-produced meat or Danish-produced meat, was conducted.

Pork meat increases iron absorption from a 5-day fully controlled diet when compared to a vegetarian diet with similar vitamin C and phytic acid content.

Meat increases absorption of non-haem iron in single-meal studies. The aim of the present study was to investigate, over a 5 d period, the potential increasing effect of consumption of pork meat in a whole diet on the fractional absorption of non-haem iron and the total absorption of iron, when compared to a vegetarian diet. A randomised cross-over design with 3 x 5 d whole-diet periods with diets containing Danish-produced meat, Polish-produced meat or a vegetarian diet was conducted.

Propylthiouracil before 131I therapy of hyperthyroid diseases: effect on cure rate evaluated by a randomized clinical trial.

A randomized clinical trial was performed to clarify whether pretreatment with propylthiouracil (PTU) before radioiodine ((131)I) therapy influences the final outcome of this therapy, as has been indicated by retrospective studies. Untreated consecutive hyperthyroid patients with Graves' disease (n = 23) or a toxic nodular goiter (n = 57) were randomized to either PTU (+PTU; n = 39) or no pretreatment (-PTU; n = 41) before compensated (131)I therapy. The median PTU dose was 100 mg, which was discontinued 4 d before treatment.

Acute effects of smoking on left ventricular function and neuro-humoral responses in patients with known or suspected ischaemic heart disease.

Systolic left ventricular function was examined by radionuclide ventriculography in 12 habitual smokers with known or suspected ischaemic heart disease, aged 33-69 years, before, during, and after smoking of two cigarettes in a row and was repeated on a non-smoking control day. Plasma concentrations of adrenaline, noradrenaline, renin, and angiotensin II were determined on the smoking day, before and immediately after smoking. During smoking, there were significant increases in heart rate (+27%), rate-pressure product (+23%), and cardiac output (+14%) in the face of a significant increase in left ventricular end-systolic volume (+5%) and significant decreases in ejection fraction (-6%) and stroke volume (-8%).

Resumption of methimazole after 131I therapy of hyperthyroid diseases: effect on thyroid function and volume evaluated by a randomized clinical trial.

Objective: Retrospective studies have indicated that anti-thyroid drugs (ATD) might possess a radioprotective effect, leading to a higher rate of recurrence of hyperthyroidism after iodine-131 ((131)I) therapy.

Design: A randomized clinical trial was performed to clarify whether resumption of methimazole after (131)I influences the final outcome of this treatment.

Methods: We assigned 149 patients with Graves' disease or a toxic nodular goitre to groups either to resume (+ATD) or not to resume (-ATD) methimazole 7 days after (131)I.

The diagnostic value of digital subtraction arthrography and radionuclide bone scan in revision hip arthroplasty.

A prospective analysis of plain serial radigraphs (PSR), digital subtraction arthrography (DSA), and radionuclide bone scans (RBS) was performed in 56 cemented total hip arthroplasties to evaluate the efficacy and usefulness of each study in the diagnosis of loosening. To avoid selection bias in the evaluation of DSA and RBS, the decision to perform repeat surgery was based exclusively on the clinical history and PSR. Results of each study were compared with intraoperative assessment of the status of components and expressed in terms of sensitivity, specificity, and accuracy.

Myocardial perfusion imaging and coronary angiography in patients with known or suspected stable angina pectoris.

Introduction: The patho-physiological cause of angina pectoris is myocardial ischaemia, which can be objectified by myocardial perfusion imaging (MPI).

Methodology: MPI was undertaken prior to coronary angiography (CAG) in 86 randomly selected patients with known or suspected stable angina pectoris.

Results: Among 78 adequately stressed patients, MPI was normal in 28 (36%) and showed reversible and irreversible perfusion abnormalities in 30 (38%) and 20 patients (26%), respectively.

[Myocardial scintigraphy and coronary arteriography in patients with known or suspected stable angina pectoris].

Introduction: Myocardial perfusion imaging (MPI) demonstrates regional hypoperfusion, whereas coronary angiography shows anatomical stenoses in epicardial arteries. Both modalities are potentially relevant in patients with stable angina pectoris.

Materials And Methods: MPI was undertaken before angiography in 86 randomly selected patients with stable angina pectoris.

Effect of a full bladder on urine production in humans.

Objective: To demonstrate the reduction in urine production in healthy humans upon bladder distension and to identify the factors responsible for this reduction.

Materials And Methods: Twelve healthy females were investigated twice in a cross-over designed experiment: once with the urinary bladder empty at the start and once pre-filled to 60% of the maximum bladder capacity. Glomerular filtration rate, effective renal plasma flow, urine content of catecholamines, blood pressure, pulse rate, plasma arginine vasopressin (AVP) and plasma concentration of renine and electrolytes were analysed together with serum osmolality.

Vertebral artery flow and spinal manipulation: a randomized, controlled and observer-blinded study.

Background: Several studies have been published on the effect of cervical rotation alone upon blood flow in the vertebral arteries. However, we have not found articles addressing the question of how spinal manipulative therapy per se affects the vertebral artery flow.

Objective: The aim of the present study was to investigate whether any changes occur in peak flow velocity in the vertebral artery after spinal manipulative therapy as measured using the latest Doppler ultrasound technology.

Survival of autotransfused red cells. 51Cr studies in 10 knee arthroplasty patients.

We determined the long-term survival of red blood cells collected postoperatively from the surgical drains, filtered and autotransfused with the Constavac Blood Conservation System. 10 patients with knee arthrosis were treated with cementless total knee arthroplasty and postoperatively connected to the autotransfusion system. Shed blood was collected for 6 hours postoperatively and then reinfused.

Sarcoidosis causes abnormal seasonal variation in 1,25-dihydroxy-cholecalciferol.

Objectives: The spontaneous seasonal variations in the calcium regulating hormones 1,25-dihydroxy-cholecalciferol (1,25-DHCC) and parathyroid hormone (PTH) were investigated in patients with sarcoidosis.

Design: Controlled, prospective observational study with measurements in the winter and summer seasons, respectively.

Subjects: Twelve patients (age: median 33, range 21-54 years) with biopsy-verified (n = 8) sarcoidosis were included as well as 11 age-matched healthy control subjects.

Left ventricle haemodynamics and vaso-active hormones during graded supine exercise in healthy male subjects.

Left ventricle systolic and diastolic functional parameters were measured by gated equilibrium radionuclide cardiography in 12 healthy men (age 33-51 years) at rest and during graded supine exercise. The leftventricle end-diastolic volume showed an initial small (11%) increase during low submaximal exercise [from mean 163 (SD 40) at rest to mean 181 (SD 48) ml], while left ventricle end-systolic volume decreased successively [from mean 59 (SD 19) to mean 39 (SD 21) ml] with increasing exercise. Stroke volume was therefore elevated at all exercise levels compared with rest [mean 104 (SD 23) ml], and the peak value [mean 128 (SD 33) ml] was found at the lowest exercise level, contributing 40% to the initial increase in cardiac output.

Angiotensin converting enzyme inhibition at rest and during exercise in congestive heart failure.

The haemodynamic effects of the sulfhydryl-containing angiotensin converting enzyme inhibitor, zofenopril, were studied in patients in New York Heart Association functional class II and III. Twenty-one clinically stable patients with coronary artery disease or cardiomyopathy completed a randomized double-blind treatment period of 2 months with either 15 mg zofenopril once daily or placebo. Regular therapy with digoxin and diuretic drugs was continued.

Acute plasma expansion: left ventricular hemodynamics and endocrine function during exercise.

In 11 healthy subjects (8 males and 3 females, age 21-59 yr) left ventricular end-diastolic (LVEDV) and end-systolic (LVESV) volumes were measured in the supine position by isotope cardiography at rest and during two submaximal one-legged exercise loads before and 1 h after acute plasma expansion (PE) by use of a 6% dextran solution (500-750 ml). After PE, blood volume increased from 5.22 +/- 0.