Search PubMed⌕ Search

Biomedical subjects

S Jamieson

Publications and source records attributed to S Jamieson.

At least 37 records · Page 2Linked to original sources
PubMed1986

Dedifferentiation of rat mammary myoepithelial-like cell lines after passage in vivo or cloning in vitro.

Myoepithelial-like cell lines from normal mammary glands of neonatal Ludwig Wistar rats, rat mammary (Rama) 401 and Rama 704E, were injected into fat pads of syngeneic animals or were single-cell cloned in vitro. Rama 401 produced tumors that were predominantly composed of elongated cells, while the subclones of both cell lines yielded multilayered structures of elongated cells when grown on floating 0.3% collagen gels in vitro. Immunocytochemical analysis of histologic sections for markers of myoepithelial cells revealed that anti-actin-myosin and human keratin sera failed to stain the Rama 401 tumor cells or subclones of both cell lines on collagen gels, but both were stained with antilaminin serum. Immunofluorescent analysis of cultures of Rama 401 tumors showed that the resulting elongated cells failed to stain with antikeratin serum, but abundant staining was observed with antilaminin and antivimentin sera, as in the tumors. Ultrastructural analysis of the Rama 401 tumor cells identified intermediate junctions and extracellular basement membrane-like material in the vicinity of plasma membrane-associated pinocytotic vesicles, but neither true desmosomes nor myofilamental bundles were observed. Thus growth of rat mammary myoepithelial-like cells as tumors in syngeneic animals or as subclones in vitro can lead to selective loss of myofilaments and prekeratin-containing intermediate filaments. Similar relatively undifferentiated elongated cells may be responsible for some of the cellular heterogeneity observed in certain carcinogen-induced rat mammary tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1983

Bronchial reactivity in asthmatic adults with normal spirometric values.

A comparison was made between airways obstruction produced by exercise. Hyperventilation of cold air, hyperventilation of room air, and inhalation of ultrasonically nebulised distilled water. Seven asthmatics with no airflow obstruction were studied together with seven normal controls. All four provocations produced comparable mean reductions in forced expired volume in one second in the asthmatic patients, but no reduction was obtained in the controls. Whereas exercise, hyperventilation of cold air, and hyperventilation of room air were associated with heat loss from airways, inhalation of nebulised distilled water was not. Inhalation of ultrasonically nebulised distilled water offers a simple additional diagnostic test for asthma. Changes in the osmolality of airway surface liquid may possibly be the common mechanism by which "fog" and hyperventilation produce bronchoconstruction.

Adult↗
PubMed1979

Cardiac allograft survival in rhesus primates treated with combined total lymphoid irradiation and rabbit antithymocyte globulin.

Eighteen abdominal heterotopic cardiac allografts were performed in outbred rhesus primates. For immunosuppression seven animals received six 100-rad/day total lymphoid irradiation (TLI) doses the week preceding transplant and three 3-mg/kg i.m. rabbit antithymocyte globulin (RATG) doses on postoperative days -1, 0, and +1; five animals were given this RATG dose but no irradiation; three were given TLI alone; and three were given no immunosuppressive therapy. Circulating T lymphocyte counts were monitored in all animals (rosettes). Graft survival in the combined TLI-RATG therapy group (169 +/- 15 days) was significantly greater than in untreated (11 +/- 1 days), RATG alone (22 +/- 12 days), or TLI alone (38 +/- 6 days) treated animals (P less than 0.001, 0.0001, and 0.001, respectively). The animals receiving combined TLI-RATG therapy also achieved significantly greater and more prolonged T lymphopenia than that obtained in the other three groups. Six of seven cardiac allografts placed in animals receiving TLI-RATG therapy were removed electively before cessation of electrical activity; however, in four of these rejection pathology was noted. Thus, it seems that combined TLI-RATG therapy may be of benefit in the management of transplant recipients, but its use will probably not abolish these patients' requirements for immunosuppressive maintenance measures.

Animals↗
PubMed1978

The effect of ICI 55,897 and clofibrate on platelet function and other tests abnormal in atherosclerosis.

There is considerable evidence that the quantity or quality of plasma lipids influences platelet function tests, and clofibrate reduces high plasma lipids and alters some platelet tests. Clofibrate was accordingly given to patients with vascular disease who were at risk of thrombosis. The heparin thrombin clotting time (HTCT), initially short and thus possibly reflecting increased activation, was regularly returned to normal after about a month's delay. The fibrinogen was also normalized but the initially abnormal anti-thrombic activity became more abnormal. ICI 55,897, an analogue of clofibrate, also normalized the HTCT and the fibrinogen and had no adverse effect on the anti-thrombin levels. This compound has no effect on plasma lipids. If it can be shown that the correction of abnormal tests conveys clinical benefit these findings suggest that ICI 55,897 might clinically be more beneficial than clofibrate. However, direct comparison of clofibrate and ICI 55,897 suggests that clofibrate is more effective in normalizing the HTCT. The mechanism underlying these drug-induced changes are unknown but they cannot be directly related to lipid changes.

Aged↗
PubMed1977

Transatrial repair of ventricular septal defects with reference to their anatomic classification.

A consecutive series of 50 children undergoing elective operations for ventricular septal defect (VSD) is presented. Atriotomy was performed routinely. Repair of the defect through the tricuspid valve was attempted in all cases and achieved in 72 percent. There was a 24 percent incidence of right bundle branch block. All patients improved symptomatically after the operation. The mortality rate was 4 percent. The right atrial route is considered to be preferable as a primary approach and has no disadvantages.

Child↗
PubMed1976

Effect of a diet of polyunsaturated fats on some platelet-function tests.

The fat in the normal diet of 19 apparently well men was partly replaced by linoleic acid. This produced striking changes in many platelet-function tests, suggesting decreased platelet activation. Twenty controls maintaining their normal diet showed no change. It is concluded that normal people have a degree of platelet activation which can be decreased. This may be relevant to the benefits attributed to a diet containing polyunsaturated fats.

Adult↗
PubMed1976

Acute platelet changes after large meals of saturated and unsaturated fats.

Large amounts of saturated fats (S.F.) or unsaturated fats (U.S.F.) were given to healthy volunteers at a single meal. The heparin thrombin clotting-time, which may measure platelet factor 4 released from platelets into the plasma, was shortened after S.F. and prolonged after U.S.F. The antithrombin clotting activity decreased after S.F. and increased after U.S.F. The platelet-count decreased and the platelet volume increased after both S.F. and U.S.F.

Adult↗
PubMed1975

Blood changes in atherosclerosis and long after myocardial infarction and venous thrombosis.

The following clinical groups of volunteers were studied: patients long after recovery from myocardial infarction (MI), others after recovery from deep vein thrombosis (DVT), patients with intermittent claudication, with diabetes, and male and female controls who were well matched. All were subjected to many platelet and clotting tests together with clinical, biochemical and haematological measurements in an attempt to find long term abnormalities in these various diseases. The male MIs differed very significantly from the controls in having much more heparin neutralizing activity (P less than 0.001)and less anti-thrombin (P less than 0.01). Less significantly, some bleeding time tests indicated less bleeding and the patients' platelets were larger. The females with MI had in general the same abnormalities but to a lesser degree. The patients with intermittent claudication, none of whom had a history of MI, had almost the same abnormalities and to the same degree. In deep vein thrombosis the heparin neutralizing activity was also clearly increased; the other tests were generally in the same direction but many were not significant. The diabetics had shorter bleeding times but little else abnormal relative to the controls, suggesting a different pathological process. When all male patients and controls were "scored" according to the degree of atherosclerosis there was a close overall correlation between the degree of atherosclerosis and the increase in the HNA level (r = --0.50, n = 66, P less than 0.001) and the decreased anti-thrombin (r = 0.25, n = 66, P less than 0.05).

Antithrombins↗
PubMed1975

Heparin neutralizing activity test in the diagnosis of acute myocardial infarction.

We have previously shown in patients after recovery from a myocardial infarct (post-MI) that the heparin neutralizing activity (HNA) in the plasma is raised and that this activity may come from platelet factor 4 derived from activated platelets. This report concerns 89 patients admitted with acute chest pain; in 54, with evidence of acute infarction, the level of HNA is much higher than in a post-MI group or controls. Over the ensuing weeks the HNA decreases to the post-MI level. In 34 patients the evidence subsequently collected excluded a diagnosis of infarction; in these there were almost always normal amounts of HNA and little overlap with the results from the patients with infarcts. This easy test is therefore likely to prove clinically useful. Its significance is discussed. The platelet count and platelet volume are both abnormal in patients with acute infarction and also in the chest pain group so these tests do not help to discriminate.

Acute Disease↗