PubMed Health⌕ Search

Biomedical subjects

I Carr

Publications and source records attributed to I Carr.

At least 37 records · Page 2Linked to original sources

Intravenous indomethacin therapy in premature infants with persistent ductus arteriosus--a double-blind controlled study.

A double-blind controlled trial of intravenous indomethacin therapy was performed using a group of 55 premature infants (27 placebo, 28 indomethacin) with a significant persistent ductus arteriosus. Indomethacin administration at a mean postnatal age of 8.9 days was followed by a significant effect on PDA in 89%; 75% of successes were attributable to indomethacin and 25% to spontaneous effects, an improvement by indomethacin of 86% in infants not undergoing spontaneous improvement. The short-term side effects of indomethacin were transient; urinary output and serum sodium concentration decreased and serum potassium concentration increased. Indomethacin administration was associated with a decreased need for assisted ventilation and a decreased need for surgical closure of PDA. There was no significant difference between the placebo and indomethacin groups in mortality and bronchopulmonary dysplasia morbidity. The infants who developed BPD had higher RDS scores and lower PO2 values, requiring higher FIO2s within four hours of birth than those who did not develop BPD, indicating a more severe underlying pulmonary disability present birth.

Clinical Trials as Topic↗

Upper airways obstruction. Presentation with systemic hypertension.

Of 14 patients whose final diagnosis was upper airways obstruction associated with heart failure, 3 presented with systemic hypertension (up to 200/100 mmHg). In 2 the hypertension was so severe that at first it had to be considered as a possible cause of the presenting symptoms. The subsequent history indicated that it was an effect of the upper airways obstruction with heart failure.

Airway Obstruction↗

Improved lung compliance following indomethacin therapy in premature infants with persistent ductus arteriosus.

In the course of a double-blind controlled study of intravenous indomethacin therapy in premature infants with patent ducts arteriosus (PDA), dynamic lung compliance (CL) was determined in 11 infants (six control, five indomethacin) who were not on assisted ventilation during the study period. The clinical, biochemical and laboratory data before the study were comparable between the groups. Following therapy with indomethacin there was a significant decrease in left atrial/aortic root ratio (LA/Ao), left ventricular end-diastolic dimension (LVEDD) on echocardiogram, and an increase in tidal volume (VT) and CL. In the control group, these variables did not change significantly. The improved lung compliance following early indomethacin closure of PDA may alter the clinical course and outcome of these premature infants.

Birth Weight↗

Lymphatic metastasis of mammary adenocarcinoma. An experimental study in the rat with a brief review of the literature.

When 5 million cells of the solid form 13762 rat mammary carcinoma are implanted into the footpad of syngeneic rats there is consistent (approximately 100%) metastasis to the draining popliteal node and thence up the lymphatic chain to the lungs. With the transmission electron microscope tumor cells are seen to penetrate gaps in the lymphatic endothelium, probably but not certainly, between endothelial cells. There is neither widespread patency nor significant destruction of lymphatic endothelium. The tumor cells penetrate in groups and lie in the lymphatic in groups with some evidence of acinar differentiation. Tumor cells lodge in groups in the subcapsular sinus and progressively pass down the radial sinusoids and destroy the node; as they grow there is extensive differentiation into adenocarcinoma. The draining lymph obtained by cannulation does not contain an increase in total cells. A few tumor cells are present mostly in clumps. Recruitment is continuous but not progressively increasing. Any theories on neoplastic invasion and metastasis must take into consideration possible aggregation of some tumor cell types in groups. The literature on experimental lymphatic metastasis is reviewed briefly.

Adenocarcinoma↗

Lysozyme production by a granuloma in vivo: output in blood and lymph in relation to ultrastructure and immunochemistry.

The output of lysozyme into the venous and lymphatic drainage of a B.C.G. experimental granuloma has been studied. There is a massive output of lysozyme by both routes maximal in the lymph at 28 days, and in the serum at 35 days after induction of the granuloma. There is no similar excretion of acid phosphatase. The lactic dehydrogenase level both in blood draining the granuloma and blood draining the normal limb is elevated but not in precise synchrony with lysozyme output. Macrophages in the granuloma show ultrastructural features suggestive of secretion of dense granules, by appearance of electron dense material in the Golgi zone, and condensation therefrom. Granules are discharged on to the surface of lipid droplets, presumably representing attempted phagocytosis, but are not discharged elsewhere on the cell surface. Granules are released by cell disintegration both of macrophages and polymorphs. Lysozyme was demonstrated immunocytochemically in macrophage granules. The macrophages in the granuloma are biosynthetically active as shown by uptake of tritiated tyrosine. The findings support the view that granulomas export lysozyme and that this is due partly to exocytosis of material by macrophages on to the surface of lipid globules and partly to cell disintegration.

Acid Phosphatase↗

Lymphatic metastasis: invasion of lymphatic vessels and efflux of tumour cells in the afferent popliteal lymph as seen in the Walker rat carcinoma.

When twenty million Walker rat carcinoma cells are injected into the footpad of albino outbred rats, there is progressive metastasis to the draining popliteal and thence para-aortic lymph nodes. The lymphatic duct efferent from the footpad and afferent to the popliteal node has been cannulated; it has been shown that there is a continuous and progressively increasing output of tumour cells, small and large lymphocytes, macrophages and polymorphs from the footpad. About 20 per cent of the cells are tumour cells. The number of tumour cells in the popliteal and para-aortic nodes has been counted using a Coulter counter and subsequent differential counting of stained smears; the nodes contain a progressively increasing number of both tumour cells and lymphoreticular cells. The early accumulation of tumour cells in the para-aortic nodes makes it evident that tumour cells pass rapidly through the primary node. Examination of the simulated primary tumour by transmission electron microscopy suggests that tumour cells move actively toward lymphatics and protrude cytoplasmic processes through gaps in the endothelium. The endothelial cell then degenerates in close proximity to tumour cell processes. This leaves gaps through which tumour cells may pass and ultimately results in lymphatics with large defects in their walls.

Animals↗

Sarcoid macrophage giant cells. Ultrastructure and lysozyme content.

Examination of the sarcoid granuloma by electron microscopic and electron microscopic immunocytochemical techniques shows that the sarcoid macrophage giant cell is rich in lysozyme, present within the centre of the syncytium in dense granules approximately 200 nm in diameter. The ultrastructure of the syncytium is that of an actively secretory cell, suggesting that the sarcoid macrophage giant cell actively produces as well as stores lysozyme, rather than being a fusion product of mononuclear cells which produce lysozyme, or being a site of storage of ingested lysozyme.

Humans↗

Pharmacokinetics of intravenously administered indomethacin in premature infants.

We studied the pharmacokinetics of indomethacin (0.3 mg/kg) given intravenously in 17 premature infants to promote closure of persistent ductus arteriosus. The decay of indomethacin generally showed an initial rapid distribution (alpha) phase followed by a slower elimination (beta) phase. The mean half-life of elimination (20.7 +/- 8 hours) was three times longer, and the mean clearance rate (13 +/0 9.5 ml/kg/hour) was seven times less than that reported in adults. The indomethacin clearance rate was linearly correlated with postnatal age (r = 0.71, P < 0.01). There was strong evidence of later re-entry of indomethacin into the plasma, suggesting that enterohepatic recirculation may be common in premature infants and may contribute to the relatively long half-life of elimination. Our data do not clarify the question of target concentration or minimal exposure time above which permanent closure may occur, but the group of infants who had permanent PDA closure after only one dose (8/17) had a significantly higher plasma indomethacin concentration time integral than the group (9/17) who needed more than one dose (P < 0.01). A 24-hour dosage interval was often sufficient when an iv indomethacin bolus of 0.3 mg/kg was used but, below the age of nonresponsiveness to indomethacin, a shorter interval may be preferable as postnatal age increases.

Double-Blind Method↗

Lymphatic metastasis of tumour; persistent transport of cells.

A model of lymphatic metastasis established by injecting Walker rat carcinoma cells into the rat footpad was used to study the output of tumour cells from the footpad. The lymphatic efferent from the footpad was cannulated in a group of rats with advanced neoplasm; it was shown that the output of tumour cells was continuous over periods up to 90 min and ranged from 10(2)-10(5) cells/min.

Animals↗

Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring.

Clinical and angiographic or autopsy data, or both, on three children with a subdivided left atrium (cor triatriatum) and an associated endocardial cushion defect are reviewed. (One child had ostium primum defect, and two had complete atrioventricular [A-V] canal.) A fourth patient demonstrates the difficulties in differentiating subdivided left atrium from supravalve mitral stenosis in the presence of an endocardial cushion defect. The clinical findings are greatly influenced by the endocardial cushion defect. A pressure gradient between the pulmonary wedge and (left or right) ventricular end-diastolic pressures in patients with an endocardial cushion defect indicates pulmonary venous obstruction and should alert one to the possibility of these combined lesions. The exact diagnosis is made with injections of angiographic contrast medium into the proximal and distal left atrial chambers, to documented the respective relations of the pulmonary veins, left atrial appendage and A-V valves to these atrial chambers. All three patients with an endocardial cushion defect and a subdivided left atrium had an associated patent ductus arteriosus. The common association of subdivided left atrium with intracardiac, pulmonary venous and aortic anomalies is again demonstrated.

Cardiac Catheterization↗

Truncus arteriosus communis with intact ventricular septum.

This is the first documented case of truncus arteriosus communis with intact ventricular septum in which extensive clinical, haemodynamic, angiographic, and pathological data are available. Angiography suggested the presence of two discrete semilunar valves but necropsy showed a basically single semilunar valve. This case fills a gap in the spectrum of aorticopulmonary, truncal, and infundibular septal defects, and reinforces the belief that the essence of truncus arteriosus communis is a single semilunar valve, common to both ventricles, which need not be associated with the defects in the adjacent parts of the structural continuum.

Angiocardiography↗

Taussig-Bing anomaly with straddling mitral valve.

Five patients with the left-sided or intermediate type (Lev) of the Taussig-Bing anomaly were found to have an associated straddling of the mitral valve. In four patients the anomaly of the mitral valve was not recognized preoperatively, and all four died postoperatively. The persistent subpulmonic obstruction caused by the abnormal attachment of the anterior mitral leaflet is considered a significant factor in the poor operative outcome. Retrospective study of angiograms in these four patients revealed diagnostic clues of straddling mitral valve which enabled us to diagnose a fifth patient angiographically and confirm the diagnosis by cross-sectional echocardiography. A surgical approach to correct this association of abnormalities is proposed which avoids operating upon the mitral valve. Its function is thereby preserved, yet the hemodynamic problem caused by the straddling is bypassed. The fifth patient in this series was successfully treated by the proposed operative method.

Adolescent↗

Solitary pulmonary nodules due to sarcoidosis.

Two patients, a 67-year-old woman and a 33-year-old man, had asymptomatic solitary nodular masses in the lung detected by roentgenographic examination. The preoperative investigations failed to make a firm diagnosis or to rule out the presence of a malignant lesion. In both patients the lesions were resected and found to contain noncaseating granulomas. Electron microscopy and immunochemical studies for lysozyme supported the diagnosis of solitary nodular sarcoidosis. Such roentgenographic presentations of sarcoid are rare.

Adult↗