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Biomedical subjects

A Mackay

Publications and source records attributed to A Mackay.

At least 55 records · Page 3Linked to original sources
PubMed1982

Genetic and antigenic variation in type 3 polioviruses: characterization of strains by monoclonal antibodies and T1 oligonucleotide mapping.

Considerable genetic and antigenic heterogeneity was detected among a collection of 17 poliovirus type 3 strains isolated between 1939 and 1958 in studies using monoclonal antibodies and by T1 oligonucleotide mapping. Heterogeneity was detected even amongst a collection of nine viruses designated Saukett and assumed to originate from the same prototype virus. The monoclonal antibodies were found to differ in their strain specificities for poliovirus type 3 strains in virus neutralization or single-radial-immunodiffusion tests. Relationships between strains detected in this way were in general consistent with those detected by oligonucleotide mapping. One of the monoclonal antibodies (NIBp 56) was able to distinguish between certain Saukett virus strains which differed by as little as a single specific oligonucleotide. The heterogeneity detected amongst Saukett viruses is of potential practical importance since these strains are used widely in the manufacture of inactivated poliovirus vaccine.

Antibodies, Monoclonal↗
PubMed1982

Immunochemical studies of polioviruses: identification of immunoreactive virus capsid polypeptides.

Investigation of the immunological reactions with individual poliovirus capsid polypeptides of antisera and monoclonal antibodies raised against poliovirus type 3 antigens are described. Virus polypeptides were separated by electrophoresis, transferred electrophoretically to nitrocellulose sheets and treated with antibody preparations. Antibody binding specifically to the virus polypeptides was then detected by application of 125I-labelled anti-immunoglobulin followed by autoradiography. The technique readily enabled the identification of the polypeptides recognized by the antibody. Antibodies present in polyclonal, type-specific neutralizing sera to poliovirus type 3 bound to the two largest capsid polypeptides (VP1 and VP2) of the homotypic poliovirus, and also to the VP1 of poliovirus type 1 and type 2. There was no obvious difference between the antibody binding patterns obtained with neutralizing and non-neutralizing antisera or between C-specific and D-specific antisera. VP1 appeared to be the immunodominant virus polypeptide. Among monoclonal antibodies specific for the C antigen of poliovirus type 3, a proportion reacted homotypically with the VP1 of poliovirus type 3. Other monoclonal antibodies of C antigen or D antigen specificity, or which reacted both with D and C antigens, some of which had potent virus-neutralizing activity, failed to give demonstrable binding reactions. The non-correlation of neutralization and immunoblot reactivity suggests that sequence determinants alone do not mediate virus neutralization which may depend on antigenic determinants specified by complex conformational arrangements of the virus capsid proteins.

Antibodies, Monoclonal↗
PubMed1981

Does inhibition of prostaglandin synthesis increase the diagnostic accuracy of the intravenous urogram in renal artery stenosis?

Intravenous urography is the standard screening test for renovascular hypertension but there is a significant incidence of false negative and false positive results. In an attempt to improve the detection rate, indomethacin was administered orally to nine patients with renal artery stenosis (proven by arteriography and by divided ureteric function studies) before rapid-series intravenous urography. This urogram was compared independently by two observers with prior similar-series urograms. Indomethacin did not alter diagnostic accuracy.

Adolescent↗
PubMed1981

Assessment of total and divided renal plasma flow by 123I-hippuran renography.

We studied 23 patients with suspected renal hypertension, including 12 with renal artery stenosis, or occlusion. Total effective renal plasma flow (ERPF) was measured in all patients by conventional p-aminohippurate (PAH) clearance and by 123I-hippuran clearance performed on the same day. A close correlation between the two techniques was obtained (r = 0.87, P less than 0.001) with the latter technique underestimating the former by a mean ratio of 0.89:1.00. We describe a technique for deriving ERPF for individual kidneys by 123I-hippuran renography, and the data obtained by this method correlate well with data obtained from bilateral ureteric catheterization studies (r = 0.076, P less than 0.001 for both affected and unaffected sides) in 17 patients. The renographic technique is particularly accurate in quantitating ERPF in the 12 patients with renal artery stenosis, and is recommended as the investigation of choice in the assessment of ERPF in patients with this condition.

Adolescent↗
PubMed1981

Recovery of renal function after renovascular surgery.

A 48-year-old woman with generalised atheromatous disease had a right nephrectomy for a renal artery occlusion in 1977. Fourteen months later she presented with severe hypertension and anuria, caused by occlusion of the left renal artery. Emergency reconstructive surgery was successful in bringing about recovery of renal function and lowering of her blood pressure. Because renal function had deteriorated slightly after the first operation and improved after the second, a comparison was made of the effects of unilateral nephrectomy and reconstructive surgery on renal function in a further 26 patients with renal artery stenosis. In 15 patients having nephrectomy, renal function deteriorated in most, while in 11 having reconstruction it improved in nine and remained constant in two.

Adolescent↗
PubMed1981

Minoxidil in the management of intractable hypertension.

Eighty-seven patients with intractable hypertension received minoxidil for a mean duration of 27 months (range three months to five years). A significant reduction in mean outpatient blood pressure from 206/129 to 158/98 mmHg (p less than 0.001 for both systolic and diastolic values) was recorded after one month's treatment. In 26 patients who received minoxidil for four or more years a further reduction in mean blood pressure to 147/89 mmHg was achieved. The mean daily dose of minoxidil was 23 mg (range 2.5 to 60 mg). In all patients a beta adrenergic neurone blocker and a diuretic were prescribed with minoxidil to counteract tachycardia and fluid retention. Thirteen patients required the addition of a fourth hypotensive agent. The use of minoxidil led to simpler drug regimens with the majority of patients well controlled on twice daily or once daily schedules. Most patients commented spontaneously on a feeling of improved wellbeing while taking minoxidil which also appeared to be relatively free from side effects commonly encountered with other hypotensive drugs, particularly drowsiness, dizziness and impotence. Fluid retention of 7 kg or more occurred in 18 patients, more commonly in those with renal impairment, but could be controlled by increasing the dose or potency of diuretics. Four patients with end stage renal failure and one patient with normal renal function developed pericardial effusions. Hirsutism was universal and limited the usefulness of the drug in women. We currently recommend minoxidil for hypertensive men who diastolic blood pressure remains greater than or equal to 110 mmHg despite an adequate trial of a beta adrenergic neurone blocker, diuretic and an additional drug, or for patients who find the side effects of such therapy intolerable.

Adolescent↗
PubMed1980

Reconstructive surgery versus nephrectomy in renal artery stenosis: comparison of effects on total and divided renal function and on blood pressure.

Twenty-six hypertensive patients with unilateral renal artery disease and normal overall renal function were treated surgically: eleven underwent arterial reconstruction and 15 unilateral nephrectomy. One year after operation there was similar reduction in blood pressure in each group (delta mean BP 45:3 mm Hg (p < 0.001) and 36.8 mm Hg (p < 0.001) respectively. contrary to previous reports, however, a small but significant improvement in overall renal function was observed in patients who underwent reconstructive surgery (delta mean serum creatinine--13.3 mumol/1 (p < 0.01); this was associated with a significant rise in para-aminohippurate (PAH) clearance in the operated kidney, while PAH clearance fell on the contralateral side. Overall renal function deteriorated in the patients who underwent unilateral nephrectomy (delta mean serum creatinine +22.7 mumol/1 (p < 0.01)). The latter was due partly to diminished clearance in the remaining kidney and partly to the loss of the excised kidney. The findings emphasise the superiority of renal artery reconstruction over nephrectomy in patients with renovascular hypertension.

Adolescent↗
PubMed1980

Oral sustained-release aminophylline in medical inpatients: factors related to toxicity and plasma theophylline concentrations.

1 Consecutive medical inpatients expected to benefit from a theophyllinate were treated with sustained-release aminophylline in a protocol conforming with ordinary practice. Of 16 patients, five had toxicity with aminophylline 450 mg daily, and a further three with 900 mg daily. Toxicity was serious in three patients. 2 Toxicity was significantly less common in cigarette smokers, and was related to higher plasma theophylline concentrations. However, there was a large overlap between concentrations associated with toxicity (as low as 9 micrograms/ml) and the accepted therapeutic range (5-20 micrograms/ml). Most patients with toxicity had theophylline levels within the therapeutic range. 3 For the same dose of aminophylline there was sevenfold variation between patients in plasma theophylline, with higher concentrations in non-smokers, infrequent alcohol users, older patients, those with left ventricular failure and those with lower serum transaminases. There variables could not be separated completely because of the small number of observations. 4 A nomogram for aminophylline dosage or monitoring of serum theophylline levels would have prevented little of the toxicity observed in these patients, although these measures would ensure that therapeutic concentrations were attained, and might prevent life-threatening toxicity.

Administration, Oral↗
PubMed1980

Ischaemic heart disease in young hypertensive women.

The association between hypertension and ischaemic heart disease was explored in a retrospective analysis of 50 severely hypertensive premenopausal women (presenting diatolic pressure greater than or equal to 120 mmHg) under 45 years of age who were seen over a seven-year period. Twenty-two per cent of these patients had angina pectoris, and 38 per cent had Minnesota code 4-1 or 5-1 changes on the resting electrocardiogram. The contribution of other risk factors, including smoking habits, was assessed: 72 per cent of the patients smoked; significantly less smoking was found among two groups of age-matched women with less severe hypertension [diastolic pressures of 90 to 104 mmHg (n=50) and 105 to 119 mmHg (n=50)]. In these latter groups, only one patient had angina pectoris and none had 4-1 or 5-1 changes on the electrocardiogram.

Adult↗
PubMed1979

Relationship between exchangeable sodium and blood pressure in different forms of hypertension in man.

1. Arterial pressure and exchangeable sodium (NaE) were measured in patients with Conn's syndrome, essential hypertension, renal artery stenosis and chronic renal failure. Comparison was made with a control group. Urine sodium excretion was measured separately from the two kidneys in patients with renal artery stenosis. 2. Compared with control, mean NaE was significantly increased in Conn's syndrome, and was normal in essential hypertension, renal artery stenosis and chronic renal failure. 3. The correlation of arterial pressure with NaE was positive and significant in Conn's syndrome, essential hypertension and chronic renal failure. 4. In contrast the correlation was significantly negative in unilateral renal artery stenosis. Patients with lowest NaE had hyponatraemia, hypokalaemia and secondary hyperaldosteronism. 5. Urinary sodium excretion from the unaffected kidney in unilateral renal artery stenosis correlated positively with arterial pressure, possibly reflecting the phenomenon of pressure-natriuresis. Patients subsequently responding least well to surgery excreted least sodium from the untouched kidney for a given arterial pressure. 6. The findings suggest important roles for arterial pressure in the regulation of sodium balance (predominant in renal artery stenosis), and for sodium balance in the regulation of arterial pressure (predominant in Conn's syndrome). The observations in essential hypertension are compatible either with an exact balance between these mechanisms or with the existence of some other mechanism raising blood pressure.

Adult↗
PubMed1979

Renal artery stenosis with severe hypertension. A rare case with detailed assessment of renin-angiotensin system before and after development of lesion.

The rare opportunity arose to assess in detail the renin-angiotensin system before and after the development of a renal artery stenosis with severe hypertension. Peripheral plasma concentrations of renin, angiotensin II, and aldosterone were known to be normal before the development of renal artery stenosis, and there were no lateralising features on renal vein sampling. Acute hypertension associated with very high peripheral plasma concentrations of renin and angiotensin II, and with pronounced lateralisation on renal vein sampling followed the development of acute unilateral renal artery stenosis. These measurements all returned to normal after nephrectomy, conforming with the pattern of changes previously established only in experimental animals.

Adult↗
PubMed1979

Self-poisoning--a complication of epilepsy.

From 1972 to 1976 130 epileptics presented 171 times to the Western Infirmary, Glasgow, as medical emergencies with self-poisoning. They constituted 3.5 per cent of 3,733 patients poisoning themselves on 4,121 occasions. Repetition of self-poisoning was commoner in epileptics (18.5 per cent) than in non-epileptics (7.0 per cent). The 130 epileptics have been compared with a non-epileptic group of self-poisoners matched for age, sex, and number of repetitions and have been found to have less alcohol excess but significantly more psychopathy. Possible explanations and prophylactic measures are discussed. In view of the relative incidence of epilepsy and self-poisoning in the community, and of epilepsy among self-poisoners in this and other studies, it is concluded that self-poisoning is a common complication of epilepsy.

Adolescent↗