PubMed Health⌕ Search

Biomedical subjects

J Mackinnon

Publications and source records attributed to J Mackinnon.

At least 19 recordsLinked to original sources
PubMed2000

[Detection and characterization by ultrasonography of soft tissue foreign bodies].

BACKGROUND: Soft tissue foreign bodies are a frequent cause of consultation in emergency rooms. It is difficult to verify their existence since conventional radiology only detects radio opaque objects. Ultrasound can be a useful diagnostic procedure. AIM: To report our experience in the detection of soft tissue foreign bodies by ultrasound examination. PATIENTS AND METHODS: The ultrasonographic appearance of vegetables, glass and plastic, metal, bone and stones was studied in gelatin preparations. In a second stage, 52 patients (27 male, aged 3 to 88 years old) were studied, in whom the presence of a soft tissue foreign body was confirmed surgically. RESULTS: The mean error of the procedure for the assessment of foreign body size was 0.2 mm in vitro and 0.5 mm in vivo. The deepness and involved planes were correctly diagnosed in 96%, the number of fragments were diagnosed correctly in 94% of cases. The type of foreign body was identified correctly in 77% of cases and complications were detected in 100% of cases. CONCLUSIONS: Ultrasound is a sensitive and accurate method for the detection of soft tissue foreign bodies.

Adolescent↗
PubMed1992

Hypertension in aortic valve disease and its response to valve replacement.

We have investigated the prevalence of hypertension and the response of blood pressure to operation in 87 patients with lone aortic valve disease who underwent aortic valve replacement. In patients with aortic stenosis alone 26% were hypertensive pre-operatively (age and sex adjusted blood pressure greater than 160 systolic and or greater than 95 mmHg diastolic) and 24% were hypertensive post-operatively. In those with aortic regurgitation alone, hypertension was present in 65% before and 57% after valve replacement using the same criterion. For combined stenosis and regurgitation, the prevalence was 54% and 62%, respectively. The post-operative increase in systolic pressure in patients with aortic stenosis occurred mainly in those with a history of left ventricular failure. In those with aortic regurgitation or combined stenosis with regurgitation, diastolic pressure rose after valve replacement resulting in a prevalence of diastolic hypertension of 44% and 35%, respectively. Blood pressure changes were not predicted by the type of valve inserted nor its size. Our data show that despite severe symptomatic aortic valve disease, systolic hypertension was common in aortic stenosis and diastolic hypertension was found in aortic regurgitation. This underlines the importance of blood pressure monitoring in patients following aortic valve replacement.

Adult↗
PubMed1989

Characterization of coronavirus JHM variants isolated from Wistar Furth rats with a viral-induced demyelinating disease.

Murine hepatitis virus (MHV) can cause neurological disease when inoculated intracerebrally (ic) into mice and rats. Specifically the JHM strain of MHV (MHV-JHM) generally causes an acute encephalitis when inoculated ic into 2-day-old Wistar Furth rats. In contrast, JHM generally produces a chronic demyelinating disease with resulting posterior paralysis when inoculated ic into 10-day-old Wistar Furth rats. In addition, while JHM readily produces a productive infection in a mouse fibroblast cell line (L-2), it does not form syncytia or replicate well in a tissue cell line of glial origin (G26-24). We have isolated and characterized three MHV-JHM viral variants from the central nervous system of two Wistar Furth rats with a MHV-JHM-induced demyelinating disease. The pattern of viral-specific mRNA for all three of these variants differed from what was observed for the wild-type parental MHV-JHM that had been passaged only in tissue culture. One of these variants, ATllf cord virus, which induced a chronic demyelinating disease in 2- or 10-day-old intracerebrally inoculated Wistar Furth rats, had a deletion in the coding region of the peplomer glycoprotein mRNA. In addition, this variant formed massive syncytia and replicated well in G26-24 cells. We have not detected this deletion in the other two JHM variants, ATllf brain virus and ATlle brain virus. ATllf brain virus and ATlle brain virus primarily produced an acute encephalitis when reinoculated into 2- or 10-day-old Wistar Furth rats. In addition, these two variants did not form syncytia and had a reduced ability to replicate in G26-24 cells.

Animals↗
PubMed1988

The St Georg sledge for unicompartmental replacement of the knee. A prospective study of 115 cases.

Since 1974, we have made a prospective study in Bristol of the results of unicompartmental knee replacement using the St Georg sledge prosthesis. A total of 115 knees in 100 patients have been followed up for 2 to 12 years (mean, 4 years 9 months). Results have assessed both by the Bristol knee score and by survivorship studies on the total series of 138 knees. Results were excellent or good in 86% and fair or poor in 14%. The survivorship study (based on a definition of failure which included significant pain or a dissatisfied patient or the need for revision) showed a cumulative success rate of 76.4% at six years, with no further failures after that time. Seven knees have been revised, in most cases for deterioration of the contralateral compartment. The operation is recommended as a satisfactory and durable form of treatment for osteoarthritis affecting a single tibiofemoral compartment.

Adult↗
PubMed1988

Interscapulothoracic resection. A case report and review of the literature.

There is a trend away from amputation for limb cancer; salvage procedures are becoming more widespread. We describe one case of interscapulothoracic resection of the shoulder and discuss methods of maximising the residual function of the arm. The procedure is recommended for patients with the correct indications.

Adolescent↗
PubMed1981

Left ventricular function in diabetes mellitus. II: Relation between clinical features and left ventricular function.

We have shown a close relation between clinical microvascular complications and abnormalities of left ventricular function in 185 established diabetics without clinical heart disease. In 50 insulin-dependent diabetics who presented at under 20 years of age there was a correlation between the duration of diabetes and the isovolumic relaxation time, minimal dimension to mitral valve opening, and ratio of pre-ejection period to left ventricular ejection time. Diabetics with mild microvascular complications were similar to diabetics with no complications except for minor prolongation of the diastolic time intervals. Those with severe complications were significantly different from diabetes with milder complications and normal controls in all variables of left ventricular function. A close relation between left ventricular function and the microvascular complications index (code 0 when no complications to code 7 when all present and severe) was found for the following variables: isovolumic relaxation time, the interval from minimal dimension to mitral valve opening, ratio of pre-ejection period to left ventricular ejection time, and pre-ejection period index. It is concluded that in diabetes abnormalities of left ventricular function are related to duration of disease and complications; and that a diabetic specific heart muscle disorder occurs frequently in patients with severe microvascular complications.

Adult↗
PubMed1981

Echocardiographic features of malignant hypertension.

Computerised apex- and echocardiography was used to study left ventricular dimensions and function in 13 patients with untreated malignant hypertension and eight with severe benign hypertension. All patients had normal left ventricular cavity dimensions. Five benign hypertensives and malignant hypertensives with a previous history of hypertension had significant thickening of the septum and posterior wall. In eight malignant hypertensives without a previous history wall thicknesses were normal. The absence of ventricular hypertrophy in some cases of malignant hypertension suggests that it is sometimes of rapid onset and not preceded by a non-malignant phase. although fractional shortening and peak Vcf were normal in all the hypertensives, diastolic left ventricular function was frequently abnormal with delayed mitral valve opening, reduced peak rate of filling, and outward endocardial motion during isovolumic relaxation. Malignant hypertensives showed a cavity shape change during isovolumic contraction, and in those without a previous history the aortic second heart sound occurred earlier. The abnormalities of function are probably the result of a combination of factors including pressure overload, abnormal myocardial properties, and myocardial ischaemia, either regional or generalized and secondary to arteriolitis.

Adult↗
PubMed1979

Intravascular haemolysis after valve replacement: comparative study between Starr-Edwards (ball valve) and Björk-Shiley (disc valve) prosthesis.

Seventy-four patients with single prosthetic valves (Björk-Shiley or Starr-Edwards) in the mitral or aortic position and 18 controls with rheumatic valvar heart disease were investigated for evidence of intravascular haemolysis. Serum lactate dehydrogenase (LDH) was used as the most sensitive indicator of haemolysis. Raised concentrations were found in a third of 39 patients with Björk-Shiley prostheses (mean 281 IU/l) and in all 35 patients with Starr-Edwards prostheses (mean 859 IU/l. Values were considerably higher in patients with Starr-Edwards prostheses and particularly in those with aortic prostheses (mean 927 IU/l). Eight out of 12 patients with haemosiderinuria had Starr-Edwards valves. Intravascular haemolysis was of little clinical significance in patients with Björk-Shiley prostheses, but some patients with Starr-Edwards prostheses became iron deficient as a result.

Aortic Valve↗