Search PubMed⌕ Search

Biomedical subjects

H Ward

Publications and source records attributed to H Ward.

At least 127 records · Page 7Linked to original sources
PubMed1984

Laser recannalization of atheromatous vessels using fiber optics.

A laser endoscope was devised using optic fibers in order to provide a means of visualization and removal of atheromatous plaques from arteries in cadavers and experimental animals. Atheromatous plaques were satisfactorily lased off in a few seconds, although contraction of lased vessels was observed. A self-focusing fiber was shown to provide laser access to and visualization of the body via a single optic fiber of feasibly less than 0.2 mm diameter.

Angioplasty, Balloon↗
PubMed1983

Destructive, nonclassical "beating" of acoustic waves and electric field generation in lased heart muscle.

Increased use of the laser in heart research warranted examination of the physical effects of the laser on the heart muscle. Laser action on the heart muscle was found to induce nonclassical (nonlinear) properties in the muscle such as low-frequency harmonics of acoustic transients. This "beating" effect resulted in a destructive thermal-wave propagation within the tissue. The nonlinear effects found in lased heart muscle had not been previously observed and occurred at laser intensities two or three orders of magnitude lower than those which occur in nonbiological media. One possible explanation of this nonlinear behavior at lower intensities was the finding that the laser induced an electric field in heart muscle which interfered with cell-membrane resting potential, and conduction. Temperatures above 300 degrees C were recorded. These are very high, considering that cells are 80-90% water, and that the boiling point of water is 100 degrees C. The laser crater profile exhibited a two-stage effect which was atypical according to conventional thermal theory. Electron micrographs demonstrated an unexpected capillary growth which had occurred postmortem in the lased heart muscle.

Animals↗
PubMed1983

Relationships between plasma theophylline clearance, liver volume and body weight in children and adults.

The influence of liver volume and body weight on plasma theophylline clearance was investigated in asthmatic children and adults. A linear relationship (r = +0.99) was demonstrated between ideal body weight and liver volume estimated by an ultrasonic scanning technique. Age-related changes in liver volume-to-body weight ratio could account for only 30% of differences in plasma theophylline clearance (1/h/kg) between children and adults. It is summized that increased hepatic mixed function oxidase activity is the major contributor to the higher plasma theophylline clearance in children.

Adult↗
PubMed1983

Small intestinal nodular lymphoid hyperplasia in patients with giardiasis and normal serum immunoglobulins.

Nodular lymphoid hyperplasia of the upper small intestine was demonstrated in 25 patients with giardiasis. All had normal serum immunoglobulin levels and seven patients initially presented with clinical findings suggestive of an abdominal lymphoma. In only two, however, was the diagnosis of primary jejunal lymphoma confirmed. It is possible that an aetiological relationship exists between recurrent parasitic infestation and nodular lymphoid hyperplasia of the upper small intestine.

Adolescent↗
PubMed1979

Consulting to children in crisis.

Although community consultation is common for psychiatrists, such activity is usually carried out on an elective rather than emergency basis. In a world troubled by community disaster situations--children are often at risk. Psychiatrists, through the use of skillful crisis consultation, can be of great help to these young people. This report describes the effort of a mental health consultation team to meet the needs of a large population of children under acute stress.

Acculturation↗
PubMed1979

Antenatal search for fetal beta-thalassaemia in a twin pregnancy.

The antenatal search for fetal beta-thalassaemia in a twin pregnancy is described. Thalassaemia major was correctly excluded in both fetuses, and some of the problems of identifying patients at risk are outlined as well as those of obtaining fetal blood in the second trimester of pregnancy.

Adult↗
PubMed1978

Plasma non-esterified fatty acids, cortisol and glucose in maternal blood during abortion induced with intra-amniotic prostaglandin F2alpha.

Serial estimations were made of plasma non-esterified fatty acids (NEFA) and glucose in 43 patients, and of plasma cortisol in 27 patients, during mid-trimester abortions induced with intra-amniotic prostaglandin F2alpha (PGF2alpha). The mean plasma concentrations of NEFA, cortisol and glucose showed rises after PGF2alpha. There was no relation betweeen these rises and the induction-delivery interval, signs of fetal distress or of intrauterine fetal death. The changes in plasma NEFA were related to the fasting level and there was an inverse relation between the changes and the patients' weight. A positive correlation existed between the change in plasma concentrations of cortisol and glucose.

Abortion, Therapeutic↗
PubMed1976

The value of amniotic fluid diamine oxidase estimations in the management of severe rhesus iso-immunization.

Serial estimations of the enzyme, diamine oxidase (D.A.O.) in liquor amnii were made in 82 rhesus sensitised women. Normal levels were found in severe disease with a favourable fetal outcome, but abnormal levels were found in 50% of the pregnancies in which severe disease was associated with fetal death. In addition, when liquor bilirubin levels predicted moderate-severe disease, D.A.O. levels were abnormal in 75% of the pregnancies in which the fetus succumbed. Abnormally low D.A.O. levels in amniotic fluid were frequently associated with the subsequent development of disseminated intra-vascular coagulation in the infant. Serial estimations of D.A.O. in amniotic fluid could be a helphful adjunct to serial liquor bilirubin estimations in the management of severe rhesus iso-immunisation.

Amine Oxidase (Copper-Containing)↗
PubMedDate not supplied

Depression in the medically ill: management considerations.

This article reviews the management of depression in three medical conditions associated with a high frequency of depression: coronary artery disease (CAD), cancer, and human immunodeficiency virus (HIV) infection. Major depression significantly increases mortality in patients with CAD. This effect of depression may be mediated by a decrease in heart rate variability. Tricyclic antidepressants (TCAs) possess Type 1A antiarrhythmic activity, which may increase the risk of sudden death. Initial data suggest that tricyclic antidepressants also may decrease heart rate variability. Antidepressant therapy is effective and can improve quality of life for patients with cancer or HIV infection. Strong social support or psychosocial interventions that improve coping skills may positively affect outcome in HIV infection and cancer. Selective serotonin reuptake inhibitors (SSRIs) and new agents may be well suited for use in depressed patients with medical illnesses because they lack the significant adverse anticholinergic and cardiovascular effects of TCAs and other classes of antidepressants.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Impaired endothelium-dependent vasodilation of coronary resistance vessels in severely stunned porcine myocardium.

The effect of stunning on endothelium-dependent responses of resistance vessels in vivo remains of interest. We utilized the coronary pressure-flow relationship during maximal vasodilation in anesthetized swine to identify subtle changes in flow reserve within stunned myocardium. Prior to and following stunning, the coronary pressure-flow relationship during maximal doses of intracoronary adenosine was compared with that of the endothelium-dependent vasodilator ATP. In 11 anesthetized swine, 30 min of partial LAD occlusion and 40 min of reperfusion reduced fractional shortening from 16 +/- 4% to 6 +/- 5% (p < 0.05). This caused a rightward shift of the coronary pressure-flow relationships during infusions of either adenosine or ATP, suggestive of increased extra vascular compressive forces. With adenosine, the slope of the linear portion of the relationship (i.e., coronary pressures > 30 mmHg) was 1.31 +/- 0.54 ml/min-mmHg at baseline and 1.30 +/- 0.55 ml/min-mmHg following stunning (NS). With ATP however, the slope decreased from 1.34 +/- 0.48 ml/min-mmHg at baseline to 1.08 +/- 0.47 ml/min-mmHg following reperfusion (p < 0.05), indicating an attenuation of endothelium-dependent vasodilator capacity. In five of the animals, the slope of the pressure-flow relationship during intracoronary nitroprusside was unchanged post-stunning, which is similar to the adenosine results. In conclusion, the data support the hypothesis that endothelium-dependent vasodilation of resistance vessels in the intact animal is altered within severely stunned myocardium. The rightward shift of the coronary pressure-flow relationships with both classes of vasodilators suggest that extra vascular factors may also play a role in limiting coronary flow reserve.

Adenosine↗