Morbidity and mortality associated with gastrointestinal dysfunction in neuromuscular disease: a single-centre case series.

Gastrointestinal dysfunction in neuromuscular disease is associated with significant morbidity and mortality. It is often underreported despite its prevalence in this cohort. There are a number of issues reported, with gastrointestinal dysmotility and intestinal pseudo-obstruction carrying a poor outcome.

Paradoxical upgrading reaction in extra-pulmonary tuberculosis: association with vitamin D therapy.

Setting: Glasgow, Scotland, UK.

Background: Paradoxical reactions in tuberculosis (TB) are a notable example of our incomplete understanding of host-pathogen interactions during anti-tuberculosis treatment.

Objectives: To determine risk factors for a TB paradoxical reaction, and specifically to assess for an independent association with vitamin D use.

Predictors of survival in patients with chronic obstructive pulmonary disease receiving long-term oxygen therapy.

Aim: Chronic obstructive pulmonary disease (COPD) affects 2-4% of the UK's population and has significant mortality, however prognostication is difficult. Long-term oxygen therapy (LTOT) has been identified by the Gold Standards Framework as a clinical indicator of advancing disease. We hypothesised the ADO index (for 'Age, Dyspnoea and airflow Obstruction'), which predicts mortality, could be applied to our LTOT population to help identify patients with poor prognosis.

The relationship between the components of pulmonary artery pressure remains constant under all conditions in both health and disease.

Background: The relationships among systolic pulmonary artery pressure (SPAP), diastolic pulmonary artery pressure (DPAP), and mean pulmonary artery pressure (MPAP) have been found to be constant in humans breathing air, at rest, while supine. It would be important for those studying the pulmonary circulation if this relationship were maintained under other circumstances, such as change in posture, during exercise, or after pharmacologic manipulation. In particular, it would be useful if the relationship were maintained when treating pulmonary hypertension because this would allow different methods of measurement to be compared, such as SPAP from echocardiography and MPAP from right heart catheterization.

Ambulatory pulmonary artery pressure monitoring during sleep and exercise in normal individuals and patients with COPD.

Background: Pulmonary hypertension is a common complication of chronic obstructive airways disease (COPD) and its presence implies a poor prognosis. However, it is difficult to measure and its specific contribution to symptoms is difficult to quantify. A micromanometer tipped pulmonary artery catheter was used to measure pulmonary artery pressure (PAP) during sleep and on exercise.

Pulmonary artery pressure measurement during exercise testing in patients with suspected pulmonary hypertension.

It is recognized that exercise produces abnormally large increases in pulmonary artery pressure in patients with pulmonary vascular disease as a consequence of a variety of disorders, but the relationship between pressure and cardiopulmonary exercise performance is poorly understood. This lack of understanding is due (in part) to difficulty making measurements of pulmonary haemodynamics using conventional fluid filled catheters. This article seeks to improve understanding by comparing variables measured during formal exercise testing with simultaneous measurements of pulmonary artery pressure using a micro-manometer tipped catheter.

Pulmonary artery pressure variation in patients with connective tissue disease: 24 hour ambulatory pulmonary artery pressure monitoring.

Background: The specific contribution of secondary pulmonary hypertension to the morbidity and mortality of patients with underlying lung disease can be difficult to assess from single measurements of pulmonary artery pressure. We have studied patients with secondary pulmonary hypertension using an ambulatory system for measuring continuous pulmonary artery pressure (PAP). We chose to study patients with connective tissue disease because they represent a group at high risk of pulmonary vascular disease, but with little disturbance of lung function.

Orthovoltage radiation therapy treatment planning using Monte Carlo simulation: treatment of neuroendocrine carcinoma of the maxillary sinus.

Dose distributions that result from treating a patient with orthovoltage beams are best determined with a treatment planning system that uses the Monte Carlo method, and such systems are not readily available. In the present work, the Monte Carlo method was used to develop a computer code for determining absorbed dose distributions in orthovoltage radiation therapy. The code was used in planning treatment of a patient with a neuroendocrine carcinoma of the maxillary sinus.

Designing, benchmarking, and applying a Monte Carlo electron transport code.

The design of a Monte Carlo electron transport code is described, with particular attention being given to the modeling of multiple-scattering, ionization, and bremsstrahlung production. Comparisons of code predictions with experimental data are presented, together with simple radiation therapy applications.

Optimal electron-beam treatment planning for retinoblastoma using a new three-dimensional Monte Carlo-based treatment planning system.

Electron-beam treatment planning for retinoblastoma was investigated and an optimal treatment plan was devised for a particular case using a new three-dimensional Monte Carlo-based treatment planning system known to be capable of correctly predicting dose perturbations caused by body surface obliquities and tissue heterogeneities. Computed tomography (CT) data files were used to construct a three-dimensional eye phantom representing the anatomy of a child's orbit. Dose distributions in sagittal, transverse, and coronal planes were predicted with 1-mm resolution.

The accuracy of single-seed dose superposition for I-125 implants.

The Monte Carlo method was used to study perturbations of single I-125 seed dose distributions created by the presence of one or three neighboring seeds for the case of seeds immersed in a water phantom. Perturbation factors were determined within the geometric shadow of neighboring seeds for two-seed designs, four-seed spacings, and several choices of dose point. The results were compared to dose estimates obtained by the simple superposition of single-seed data for one- and two-plane implants.

An improved electron multiple-scattering distribution for Monte Carlo transport simulation.

An improved electron multiple-scattering distribution is presented in the form of a composite function which combines three expressions valid over different scattering angle regions: a modified relativistic Mott single-scattering term for large angle scattering, a modified Moliere Gaussian term for small angle scattering, and an exponential term for the intermediate angle scattering region. The exponential term has two adjustable parameters which make possible the smooth transition from the large to the small scattering angle regions. The proposed distribution exhibits better agreement with experiment than other multiple-scattering distributions commonly used in Monte Carlo electron transport codes, is amenable to direct sampling over a continuous range of electron energies and step sizes, can be used for elements of any atomic number, and is particularly suitable for use on small memory computers.

Two-dimensional dose distribution around a commercial 125I seed.

The Monte Carlo method was used to investigate the dose distribution around a 3M Company model 6711 125I seed immersed in a water phantom. Dose rate per unit activity data are presented as a matrix of 63 points surrounding the seed. Relative dose data are presented graphically for two mutually perpendicular directions and compared with the corresponding data for the only other 125I seed currently available, the 3M Company model 6702 125I seed.

Monte Carlo simulation of the dose distribution around 125I seeds.

The Monte Carlo method was used to investigate dose distributions around the 3M Company model 6701 and model 6702 125I brachytherapy seeds. The transverse axis dose distributions of the two seed models were found to be nearly identical, but the longitudinal axis dose distributions differed significantly. Seed design influences upon dose distributions also were investigated.

Metabolism and salvage of adenine and hypoxanthine by myocytes isolated from mature rat heart.

Adenine and hypoxanthine can be utilised by cardiac muscle cells as substrates for the synthesis of ATP. A possible therapeutic advantage of these compounds as high-energy precursors is their lack of vasoactive properties. Myocytes isolated from mature rat heart have been used to establish in kinetic detail the capacity of the heart to incorporate adenine, hypoxanthine and ribose into cellular nucleotides.

Removal of streaking artifact in computed tomography.

In transmission computed tomography, relative X-ray attenuation measurements are made at various angles around a patient's body. These input projection data are reconstructed to yield a cross-sectional view of internal structure. If the body section contains material that severely attenuates the X-ray beam (e.

An interactive program to calculate the treatment time for 60Co single beam, opposing beam, and rotational beam radiation therapy.

An interactive computer program for calculating treatment times for 60Co single beam, opposing beam, or rotational beam radiation therapy is described. The program allows the user to enter parameters specific to his machine. Analytic expressions are used to represent the depth dose, backscatter factor, tissue-air ratio, collimator factor, and beam attenuation of a block-carrying tray.

Confirmation of a speculation concerning average tissue-air ratio determinations for rotational Co-60 radiation therapy treatment planning.

The question of the number of radii which are necessary to accurately determine the average tissue-air ratio (TAR) to be used in 60Co rotational radiation therapy treatment planning was studied using actual patient contours. It was found that 12 radii adequately determine the average TAR for clinical purposes.

A pattern recognition method for the removal of streaking artifact in computed tomography.

A new method is presented for the removal of streaking artifact in computed tomography. The method uses a nearest-neighbor pattern recognition technique to redetermine ray sums that intersect the foreign object responsible for the streaking. When the method is applied to the removal of streaking artifact caused by lead in a skull phantom, excellent results are obtained.