Search PubMed⌕ Search

Biomedical subjects

M R Thomas

Publications and source records attributed to M R Thomas.

At least 163 records · Page 9Linked to original sources
PubMed1976

IgE levels in Hodgkin's disease.

Serum IgE levels were determined in a retrospectively selected group of 37 patients with Hodgkin's disease. IgE was determined by a double-antibody radioimmunoassay and expressed as International Units/ml. Patients were analyzed by stage and histologic classification of disease and compared to a group of 102 normal controls. IgE levels for the total group with Hodgkin's disease were significantly higher (p = .02) than controls but there was considerable overlap in ranges. Significant elevation of IgE was found in nodular sclerosing (p = .005) and Stage II Hodgkin's disease p = .0025). IgE elevations seen in other stages and histologic classes were not significant. While not conclusive, the IgE elevations that were found would be consistent with a suppressor T cell dysfunction in Hodgkin's disease.

Hodgkin Disease↗
PubMed1971

The function of the paramedian reticular nucleus in the control of heart rate in the cat.

1. Selective electrical stimulation of the paramedian reticular nucleus (PRN) in anaesthetized and decerebrate-anaesthetized cats elicited cardiac slowing which was shown to be due to inhibition of the sympathetic input to the heart.2. In decerebrate preparations stimulation of the PRN elicited cardioacceleration which was abolished by bilateral vagotomy.3. It is suggested that these changes in heart rate in opposite directions can be accounted for by an inhibitory influence of the PRN on both neural inputs to the heart. In the absence of vagal activity, demonstrated in anaesthetized and decerebrate-anaesthetized preparations, the response to stimulation of the PRN resulted in cardiac slowing. In contrast, when both sympathetic and parasympathetic pathways were active (decerebrate preparation) stimulation of the PRN resulted in cardio-acceleration, due to simultaneous inhibition of the two neural inputs to the heart.4. It is concluded that the two inhibitory functions of the PRN are probably mediated by two different populations of neurones and that the PRN plays an integrative role in the medullary control of heart rate.

Anesthesia, Intravenous↗
PubMedDate not supplied

The value of transthoracic echocardiography during percutaneous balloon mitral valvuloplasty.

Percutaneous balloon mitral valvuloplasty is a standard alternative to surgery in a selected group of patients with symptomatic dominant rheumatic mitral stenosis. With careful transthoracic and transesophageal echocardiographic selection of patients, there is a low complication and high success rate. Echocardiography has also been established as extremely useful in the long-term follow-up of patients. We present four cases that highlight our view that transthoracic echocardiography should be performed during the procedure, after each balloon inflation, and before and after the intervention. In our experience transthoracic echocardiography during balloon mitral valvuloplasty is invaluable in assessing commissural separation, increasing mitral valve area, new mitral regurgitation, and occasional unexpected anatomic sequelae of balloon inflation.

Adult↗
PubMedDate not supplied

Left atrial spontaneous echo contrast assessed by TEE in patients with either native mitral valve disease or mitral valve replacement.

The incidence of spontaneous echo contrast in the left atrium, the factors with which it is associated, and its clinical significance were studied in 128 patients with native mitral valve disease or mitral valve replacement. All patients underwent both transesophageal and transthoracic echocardiography. Spontaneous echo contrast was visualized in 42 patients (33%) during transesophageal and in none during transthoracic echocardiography. Patients with spontaneous echo contrast had a significantly larger left atrial diameter (6.1 [1.1] cm vs 4.9 [0.9] cm, p < 0.001) and a greater incidence of both atrial fibrillation (54% vs 4%, p < 0.001) and left atrial thrombi (60% vs 28%, p < 0.01) compared with patients without spontaneous echo contrast. Multivariant analysis confirmed that these factors were independently associated with spontaneous echo contrast (left atrial size, p < 0.001; atrial fibrillation, p < 0.001; left atrial thrombus, p < 0.01). Patients with pure mitral regurgitation did not have any spontaneous echo contrast and anticoagulation did not influence its incidence. Spontaneous echo contrast was the only factor that was associated with a previous history of systemic embolization (history of systemic emboli in 28.6% of patients with spontaneous echo contrast vs 13.9% without spontaneous echo contrast, p < 0.05). In conclusion, spontaneous echo contrast is a common finding in the left atrium of patients with mitral valve disease or mitral valve replacement and represents a marker of increased thromboembolic risk in these patients.

Adult↗
PubMedDate not supplied

Aortoatrial fistulae diagnosed by transthoracic and transesophageal echocardiography: advantages of the transesophageal approach.

Aortoatrial fistulae are uncommon, providing a difficult diagnostic challenge both in the clinical diagnosis and in the choice of an imaging modality that fully delineates the abnormal anatomy and flow patterns. This report describes four cases of aortoatrial fistula resulting from three different underlying causes. The fistula communicated with the right atrium in three cases and the left atrium in one. We also describe the diagnostic information obtained during both transthoracic and transesophageal echocardiography and stress that full detail of the abnormal anatomy and shunting could be obtained only with the transesophageal approach, with its improved image quality of the aortic root. No extra information, other than the coronary anatomy, was obtained during aortography in the two patients who underwent cardiac catheterization. Transesophageal echocardiography should, therefore, be the investigation of choice in patients in whom there is a suspicion of aortoatrial shunting after clinical examination and routine transthoracic studies, and it may avoid the need for invasive investigation in these potentially hemodynamically unstable patients.

Adult↗
PubMedDate not supplied

Transesophageal echocardiography in the detection and surgical management of a papillary fibroelastoma of the mitral valve causing partial mitral valve obstruction.

Primary mitral valve tumors are rare. We describe the transesophageal appearances of a papillary fibroelastoma (Lambl's giant excrescence) of the anterior mitral valve leaflet causing partial mitral valve obstruction. Transesophageal echocardiography proved particularly useful in identifying the limited attachment of the tumor to the anterior mitral valve leaflet and excluding its attachment to the interatrial septum. These features helped to exclude the possibility of the tumor being a left atrial myxoma, the primary differential diagnosis of the lesion. Transesophageal echocardiography enabled the planned surgical option to be mitral valve repair and also allowed intraoperative monitoring to assess the results of the surgical repair.

Aged↗
PubMedDate not supplied

Comparison of macronutrient concentration of preterm human milk between two milk expression techniques and two techniques for quantitation of energy.

Generally, when newborns in intensive care units receive human milk, we do not know the quantity of nutrients in that milk because such analysis is time-consuming and expensive. In our study, however, we sought to compare fat, protein, lactose, and energy concentration of a three-times-a-day sampling with a 24-h expression and to measure the difference between the calculated energy yield from protein, fat, and carbohydrate measurements and bomb calorimetry. At 14-18 days postpartum, 20 mothers of premature infants (30-34 weeks' gestation) expressed milk three times a day: 8 a.m., 12 p.m., and 8 p.m. At these three times, each mother expressed 3-5 ml of fore-milk and 3-5 ml of hind-milk for the sampling; the result was pooled for a 24-h expression. Only fat concentration differed significantly between fore- and hind-milk samples. Protein, fat, lactose, and energy concentration did not differ significantly between the two collection methods, 24-h expression and sampling. Moreover, we found no significant difference between the calculated number for energy content and the bomb calorimetry method of energy determination. The average fore- and hind-milk samples at 12 p.m. matched the 24-h milk expression. For clinical use, a milk sample obtained around 12 p.m. can predict macronutrient concentration, therefore allowing us to calculate an infant's approximate nutrient consumption.

Calorimetry↗