Histopathology of spontaneous brain herniations into the middle ear

Two patients with spontaneous brain herniation into the middle ear have been operated on with a combined otoneurological approach. In case No. 1, two 2 x 3 mm arachnoid tissue herniations were found in the tegmen antri of the left ear. Six years later, a 8 x 9 mm mass consisting of prolapsed brain was removed from the right ear. The histological examination showed normal but disorganized nervous tissue. The surface consisted of middle ear mucosa or modified glial cells. More deeply numerous well preserved neurons and synapses were observed. In case No. 2, a 2 x 1 cm herniation was found in contact with the ossicles and the bony walls of the middle ear. The herniation consisted of partly degenerated nervous tissue which could explain the episode of temporal lobe seizure the patient experienced 8 years before surgery. In the world literature during the last 40 years, 29 cases of spontaneous or idiopathic brain herniation into the middle ear and mastoid have been reported. In 10, the herniations were multiple, as in our case No. 1. Case No. 1 is interesting also because the spontaneous brain herniation was bilateral.

A semiautomated method for measuring brain infarct volume

An accurate, reproducible method for determining the infarct volumes of gray matter structures is presented for use with presently available image analysis systems. Areas of stained sections with optical densities above that of a threshold value are automatically recognized and measured. This eliminates the potential error and bias inherent in manually delineating infarcted regions. Moreover, the volume of surviving normal gray matter is determined rather than that of the infarct. This approach minimizes the error that is introduced by edema, which distorts and enlarges the infarcted tissue and surrounding white matter.

Serial evaluation of ventricular function after percutaneous aortic balloon valvuloplasty

To evaluate the serial changes in right and left ventricular performance after percutaneous aortic balloon valvuloplasty, 15 patients, mean age 75 +/- 18 years, and in New York Heart Association (NYHA) class III, were studied with first-pass radionuclide angiocardiography (RNA) immediately before, then 5 minutes, 2 hours, 4 hours, 6 hours, and 3 days after valvuloplasty. No change was observed in heart rate, aortic root systolic pressure, Fick, or RNA cardiac output, amount of aortic insufficiency measured either angiographically or with the regurgitant fraction determination immediately after valvuloplasty. However, significant changes were observed in the peak-to-peak aortic valve gradient (63 to 35 mm Hg; p less than 0.001), mean aortic valve gradient (54 to 33 mm Hg; p less than 0.001), aortic valve area (0.60 to 0.90 cm2; p less than 0.001), and meridional wall stress (79 to 50 10(3) dynes/cm2; p less than 0.01) immediately following valvuloplasty. In addition, left ventricular end-diastolic volume decreased from 186 to 153 ml (p less than 0.001), end-systolic volume decreased from 114 to 86 ml (p less than 0.001), micromanometric left ventricular end-diastolic pressure decreased from 20 to 14 mm Hg (p less than 0.02), and left ventricular ejection fraction increased from 0.39 to 0.45 (p less than 0.001). Peak positive left ventricular dP/dt and end-systolic pressure-volume ratio did not change after valvuloplasty (1700 to 1550 mm Hg/sec, 2.1 to 2.5 mm Hg/ml, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Interface between geriatric and general medicine

Information about their practice has been obtained from 652 consultant physicians in geriatric medicine representing 203 (78%) of the 259 health districts in the United Kingdom (UK). Joint appointments in general and geriatric medicine are held by 19.6%. Admissions policies included admissions selected by suitability for the department (58%) or on an age-related basis (37%)--the most common cut-off age being 75 years. In only a minority, however, were all medical patients above the designated age accepted. The policy generally applied only as long as empty geriatric beds were available. Integrated service (admitting geriatric and internal medicine patients of all ages to a common pool of beds) was practised in 5% of districts. Only one provided long-term care alone. Specialist interests within or in addition to geriatrics were reported by 26% of whole time and 48% of joint appointees. 'Pure' geriatrics remains the most popular form of practice.

Sexing the human fetus and identification of polyploid nuclei by DNA-DNA in situ hybridisation in interphase nuclei

Samples of human adult lymphocytes, fetal lymphocytes, amniotic fluid cells, and chorionic villus cells were sexed independently by cytogenetics and DNA-DNA in situ hybridisation to a tritiated Y probe. For the in situ hybridisation analysis, the presence of Y bodies (hybridisation bodies) in 100 interphase nuclei were scored after autoradiography. In all, 82/83 samples were sexed in this way (one technical failure) and 78/82 were sexed by both in situ hybridisation and cytogenetics. There was complete agreement between the two methods. There was a considerable variation (40-100%) in the percentage of interphase nuclei with a hybridisation body among the male samples, but very few nuclei from female samples showed significant hybridisation. In situ hybridisation could be used to sex the conceptus when males but not females are at risk for various X-linked genetic disorders and may also be useful for detecting 45,X/46,XY mosaicism or polyploid/diploid mosaicism. This would be particularly useful for direct preparations of chorionic villus samples, which often prove difficult to analyse cytogenetically but offer the best means of avoiding maternal contamination. Some interphase nuclei had more than one hybridisation body, and this was most commonly found among amniotic fluid cells. Comparison of sizes of nuclei with one or two hybridisation bodies strongly suggested that most of the amniotic fluid cell nuclei with two hybridisation bodies were tetraploid.

Determination of the molecular size distribution of immunoglobulin G (IgG) in intravenous IgG-albumin formulations by high-performance liquid chromatography

Recent reports have expressed concern about the safety of intravenous human immunoglobulin G (IgG) preparations. Evidence seems to indicate that aggregates in these formulations are responsible for several adverse reactions in some patients, including anaphylaxis and dyspnea. Therefore, monitoring the molecular size distribution of IgG in these products is essential for ensuring their safety. This paper describes a sensitive and precise two-stage high-performance liquid chromatographic method for determining the molecular size distribution profile of IgG in an intravenous formulation stabilized with albumin. In the first step, all molecular forms of IgG are separated from all molecular forms of albumin by anion-exchange chromatography. In the second stage, a portion of the collected IgG fraction is re-chromatographed by size-exclusion chromatography and separated into its aggregate, dimer, and monomer components. Although some minor losses of aggregate do occur in the procedure, the overall molecular size distribution is not significantly affected. The method described is both time-efficient and accurate, and represents an improvement over existing methods.

New child abuse spectrum in an era of increased awareness

Three hundred eight-two children were evaluated for abuse or neglect during a 30-month period in a pediatric clinic in a county hospital. Fifty-one percent presented for sexual abuse, 34% for physical abuse, and 15% for neglect. Thirteen children were hospitalized. Children examined for sexual abuse had a mean age of 5.8 years and a median age of 5 years; 71% had normal findings on examination, including 48% of those with a history of penetration. Fourteen children were brought for evaluation on the basis of caretakers' misinterpretation, overconcern, or malice. The current spectrum of patients seen for child abuse or neglect reflects increased public and professional awareness of the problem. Earlier recognition of abuse, especially greater readiness to consider sexual abuse, brings younger, less physically injured children to the clinic.

Dietitian-patient communication: a critical appraisal and approach to training

This paper argues that dietetic interviews are strongly influenced by the traditional model of the medical consultation. Evidence concerning the limitations of this model, in terms of patient satisfaction and compliance, for both doctor-patient and dietitian-patient communication, is reviewed. The interpretation of this evidence suggests that dissatisfaction and non-compliance are related to two sets of variables: cognitive and socio-emotional. A programme of training on communication and counselling skills for dietetic students, which aims to enable students to address these problems, is described and a short-term evaluation by the students of this programme is reported. The paper concludes with an evaluation of the course by staff members and some comments as to possible future trends in dietetic education.

Sino-atrial arrest due to temporal lobe epilepsy

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Relations between erythrocyte lithium efflux, blood pressure and family histories of hypertension and cardiovascular disease: studies in a factory workforce and hypertension clinic

Sodium-dependent lithium efflux was measured in erythrocytes from 399 factory workers and 125 patients attending a hypertension clinic. Thirty-two factory workers had unsuspected essential hypertension (diastolic blood pressure phase V greater than 90 mmHg). These subjects had the same average erythrocyte lithium efflux as those with normal blood pressure, whereas lithium efflux was increased on average in the clinic hypertensives. Lithium efflux was greater in those subjects from both groups who had a family history of high blood pressure. Our clinic hypertensives did not have raised lithium efflux when they were matched for family history; the increased lithium efflux in the group as a whole (and in analysis of published reports) was explained by an excess of subjects with a family history of hypertension. Furthermore, when a family history of hypertension was present, lithium efflux was increased on average only in those whose relatives also had a cardiovascular event associated with their high blood pressure. These results, in conjunction with detailed analysis of the distributions of lithium efflux within the groups, suggest that, though not linked to blood pressure itself, an increase in lithium efflux is an inherited marker for those at risk from the cardiovascular complications associated with high blood pressure.

General medicine in the 'eighties

The general physician with or without an interest is directly responsible for the initial and continuing care in most acute medicine. Specialty interests cover the whole range of medicine but in most instances are subordinate to the claims of general medicine. Consultants in district general hospitals carry a bigger caseload in acute medicine than their colleagues in teaching hospitals, and this has implications for undergraduate and postgraduate training. The management of patients in intensive care units remains very much the task of the general physician. The general physician will continue to be an essential member of the hospital service in the foreseeable future.

Enalapril in moderate to severe hypertension: a comparison with atenolol

Patients with moderate to severe essential hypertension (mean untreated supine blood pressure 190/112 mm Hg) received once daily enalapril 20-40 mg or atenolol 50-100 mg, supplemented if required by hydrochlorothiazide 25-100 mg, in a randomized observer-blind trial. Both regimens produced a highly significant reduction in supine and standing blood pressure. There was no significant difference in the antihypertensive effects of enalapril and atenolol when they were used as monotherapy. After hydrochlorothiazide was added to patients not achieving 'target' blood pressure, the fall in systolic pressure was significantly greater in the enalapril group than in the atenolol group, despite similar dosage of hydrochlorothiazide in the two groups. At the end of 6 months' treatment, a supine diastolic blood pressure of 90 mm Hg or below was achieved in 74% of patients on enalapril plus hydrochlorothiazide and 56% of patients on atenolol plus hydrochlorothiazide. This difference was not statistically significant. A small rise in plasma urea and creatinine was observed in the enalapril group and a small rise of urea only in the atenolol group. These changes were statistically significant but of uncertain clinical importance. This study confirms that once daily enalapril and atenolol, both alone and in combination with hydrochlorothiazide, are effective drugs in the management of moderate to severe hypertension.

Bruising: a useful physical sign in ruptured knee joint

The clinical distinction of a ruptured knee joint or popliteal cyst from a deep venous thrombosis is important in the planning of treatment, particularly to avoid anticoagulant therapy. Bruising, which may be severe, may occur when inappropriate anticoagulants are administered. It is less well recognised that spontaneous bruising may occur with a ruptured knee joint even when anticoagulant therapy has not been given. A case is presented which demonstrates this useful physical sign and shows also the value of the patient's history in eliciting the diagnosis. The bruising extended to the foot, its gravitational and propulsive advance being halted by the pressure of footwear. This appearance has not been emphasised in the rheumatology literature.

A study of two diuretic/potassium combinations in heart failure

The effect of potassium supplements was studied in 28 patients taking long term frusemide (40-80 mg daily). Plasma potassium fell when supplements were stopped, and rose towards prior values on the potassium/frusemide combination, Diumide K. In a crossover study in 14 of these patients comparing equivalent doses of frusemide, Diumide K (frusemide 40 mg, potassium 8 mmol), bumetanide, and Burinex K (bumetanide 0.5 mg, potassium 7.7 mmol) plasma potassium was lower on frusemide than on bumetanide. On Diumide K and Burinex K plasma potassium rose significantly but did not reach the levels on prior therapy. Small doses of potassium in combined formulations seem to be effective in countering the mild hypokalaemia caused by loop diuretics.

Retinal atrophy induced by intravitreous colchicine

Colchicine is known to inhibit axoplasmic transport in ganglion cells. Previous studies have shown considerable, but largely reversible, retinal changes after low dosages of intravitreal colchicine in experimental animals. In the present study, the effects of 1.0 to 100 micrograms of intravitreal colchicine in monkeys were studied by ophthalmoscopy, light microscopy, and electron microscopy. Optic atrophy was ophthalmoscopically evident within 4 weeks after a single dose of 10 micrograms or more. Morphologic changes included progressive swelling of retinal neurons, accumulation of a fibrillogranular material, displacement of organelles, and loss of microtubules. Plasmalemmal rupture was observed in ganglion cells and in photoreceptors after as little as 1 microgram of colchicine. Relative sparing of the cone cells was noted. The retina of monkeys appears to be more sensitive to intravitreal colchicine than that of certain lower animals.

Insulin receptors in calf and human retinal blood vessels

A system for isolation of capillaries from the retina has been adapted to biochemical studies in vitro. Insulin receptors were identified in human and calf retinal blood vessels. Binding of 125I insulin by calf retinal blood vessels takes place through high affinity (low capacity) and low affinity (high capacity) receptor sites. Insulin binding is inhibited by glucagon, and cGMP and proinsulin. Dissociation of insulin receptor protein or lipid with Triton X-100 or phospholipase results in significant decreases in 125I insulin binding by retinal blood vessels. Dissociation of insulin bound occurs only at 0 degrees C which may be due to rapid internalization of insulin at higher temperatures. Activities of cAMP and cGMP phosphodiesterases and cyclase of retinal vessels were not significantly changed by incubation with insulin. At high concentrations in the media human growth hormone stimulates and then inhibits I125 insulin binding by retinal capillaries.

Attitudes of faculty members of schools of public health toward public service

Public service has long been considered one of a traditional triad of academic functions--teaching, research, and service. Yet even in schools of public health, where service is purported to be an integral component of the institution's mission, faculty generally do not accord as high a value to service performance or approach it with the same degree of commitment as they do research and teaching. A study was conducted to examine faculty perceptions and attitudes toward the service function and its relationship to teaching and research within schools of public health. The data were taken from a mailed questionnaire survey of 20-30 faculty members in each of 20 schools of public health in the United States. The response rate was 71 percent, or 387 returned questionnaires. Respondents generally felt that the greatest value of service lies in its potential for enhancing the image and prestige of the school, and in the fulfillment of the community obligation of the institution. The possibility that service might bring about improvements in faculty research and teaching, or improvements in health services and public health, was rated significantly lower. Thus, respondents did not view service as useful for its contribution to their own careers or to public health practice as much as they regarded it as a beneficial contribution to the reputation of the institution. This view undermines the traditionally held notion that public service either benefits a particular constituency outside the school or enhances the professional development of faculty members themselves.

The heterogeneity of essential hypertension. Relation between lithium efflux and sodium content of erythrocytes and a family history of hypertension

The lithium efflux and sodium content of erythrocytes were measured in 75 patients with untreated essential hypertension. The average values of both were higher than those of normotensive control subjects. Values above the range in the controls were found only in patients with a family history of hypertension, and in these the frequency of raised lithium efflux was 76% and of raised sodium content was 36%. Measurement of lithium efflux and sodium content, together with the family history, allows patients with essential hypertension to be categorised into four groups.

An universal and accurate replica technique for scanning electron microscope study in clinical dentistry

One of the main concerns of dental research is the observation of the oral tissues and the materials applied to the dentition. The changes in composition and structure of the outer surfaces and the materials deposited on these surfaces are of special interest. In the literature, a variety of replica techniques for these purposes is described (Grundy in 1971 [12]; Saxton in 1973 [25]). The use of these techniques is limited because of artifacts in the samples, and a restricted resolution power resulting from useful magnifications in the order of 800x. An accurate and universal replica technique for the examination of specimens to be viewed under the SEM has been developed. The first impression is made by a light body silicone elastomer (President Coltene). The positive replica is made by electrodeposition of copper in an electro plating bath (Acru plat 5 electronic, Dr. Th. Wieland, D-7530 Pforzheim). The reliability and accuracy of this replica technique was verified by a scanning electron microscopic comparison of the replicas and the actual structures of etched enamel. To illustrate the applicability of the replica technique to structures with much lower hardness, also high resolution images of dental plaque were produced. The copper surface offers a perfect, original and proper electroconductive medium that withstands the bombardment of electrons and the relatively severe conditions in the scanning electron microscope. Reproducibility was accurate as judged by the duplication in position, size, and shape of the fine detail at magnifications of 7500x offering a resolution of 25 nm.

The early and late effects of digoxin treatment on the sodium transport, sodium content and Na+K+- ATPase or erythrocytes

1 Erythrocyte sodium content, sodium transport (ouabain sensitive sodium flux Eos, and ouabain sensitive efflux rate constant ERCos) sodium, potassium activated ouabain sensitive adenosine triphosphatase (Na+K+ATPase) and plasma digoxin were measured in patients during acute digitalisation and in patients who were on long-term digoxin treatment. 2 In the six patients who were studied during digitalisation, the ERCos and Na+K+ATPase activity decreased and erythrocyte sodium content increased during days 2-4 treatment, but there was no change in Eos. 3 In 39 patients on long term digoxin therapy (2-119 months) the erythrocyte sodium content was normal, but the erythrocyte Na+K+ATPase activity was higher than the control group. When the results from these 39 patients were divided according to the duration of treatment it was found that the erythrocyte sodium content was higher in patients treated for 2-4 months than in patients treated for longer periods and the erythrocyte Na+K+ATPase activity increased with duration of treatment. In eight patients (duration of treatment greater than 29 months) in whom ERCos and Eos were measured, ERCos and Eos were higher than the control group. 4 The results suggest that the effects of digoxin on erythrocytes which occur during acute digoxin treatment do not persist in the long term. 5 The possible explanation for the higher ERCos, Eos and Na+K+ATPase activity in patients treated with digoxin for more than 2 months is discussed.

Arthropathy in Dressler's syndrome

Three patients developed a polyarthritis in association with Dressler's (post-myocardial infarction) syndrome. Joint involvement was more pronounced in the upper limbs and persisted many months after other features of Dressler's syndrome had settled. In 2 cases the findings in the joints were slight and might have been overlooked but for the persistently raised ESR. There was a prompt symptomatic response to prednisone.

The erythrocyte sodium and potassium in patients treated with digoxin

1 Four healthy persons and ten patients with heart failure were studied for 5 to 20 days after they started taking digoxin. The sodium content of their erythrocytes increased and there was an equimolar decrease in potassium content. 2 The increase in erythrocyte sodium for a given increase in plasma digoxin during this acute digitalization was less on average and varied more in the patients than in the healthy persons, that is the patients' erythrocytes were less responsive to digoxin. 3 The average erythrocyte sodium was greater in 183 patients who had been taking digoxin for at least 2 months than in 100 healthy persons not taking digoxin but there was no significant correlation between the plasma digoxin concentrations and erythrocyte sodium concentration in the patients. Indeed, there was no apparent change in the erythrocyte sodium in many of the patients taking digoxin. 4 If the erythrocyte sodium concentration is a reliable guide to the tissue effects of digoxin then the results suggest that there is a wide variation in the response to digoxin between patients both during acute digitalization and during chronic treatment with digoxin.

Qualitative and quantitative methods of studying the effect of lipids on bacteria grown on the surface of solid culture media

New qualitative and quantitative methods are described for the investigation of the antibacterial activity of lipids on solid media by the application of lipid-impregnated filter paper over a lawn of the organisms. The methods have been used to investigate the antibacterial activity of unsaturated fatty acids that are important in skin defence. Oleic and linoleic acids inhibited Streptococcus pyogenes markedly, Staphylococcus aureus and Staph epidermidis to a lesser extent and had no effect on Escherichia coli and Pseudomonas aeruginosa. The inhibition of growth of a strain of Str. pyogenes from a sore throat was greater than that of a strain from an outbreak of impetigo. Linoleic acid was a more potent inhibitor of bacterial growth than oleic acid, and with both acids inhibition was more pronounced under aerobic than under anaerobic conditions of incubation. The methods described could be applied in other fields such as pharmacology, horticulture and industry.

Hypokalaemia and diuretics: an analysis of publications

Published data have been used to define the characteristics of the fall in serum potassium concentration after taking diuretics and the efficacy of the various treatments given to prevent or correct it. The average fall is less after the usual doses of frusemide (about 0.3 mmol/l) than after the usual doses of thiazides (about 0.6 mmol/l) and is little influenced by the dose or duration of treatment. The fall with a given drug is the same in heart failure and hypertension, but the initial serum potassium concentration is higher in heart failure, so that the final value is lower in hypertension. In standard doses potassium supplements are less effective than potassium-retaining diuretics in correcting the hypokalaemia. The relation between the average serum potassium value and the frequency of low values (hypokalaemia) is such that very low values after taking diuretics are unusual in patients with hypertension or heart failure. Hypokalaemia would almost disappear as an important complication of diuretic treatment if it was defined as a value less than 3.0 mmol/l rather than as a value less than 3.5 mmol/l.

Comparison of five beta-adrenoreceptor antagonists with different ancillary properties during sustained twice daily therapy in angina pectoris

The effects of five beta-adrenoreceptor blocking agents and placebo during twice daily sustained therapy were compared in 23 patients with stable, exertional angina pectoris. The study was double blind in design, and each drug was prescribed for a period of one month in a random fashion. The number of anginal attacks and consumption of glyceryl trinitrate tablets during the one month period were significantly reduced by a similar degree during therapy with all five beta blocking drugs in comparison to the placebo (P less than 0.01). Exercise tolerance, when assessed 12 hours after a previous dose had been given and 1 hour after the morning dose was given, also improved by a similar degree with all five drugs in comparison to the placebo (P less than 0.01). The increase in exercise duration was associated with a significant reduction in the S-T segment depression, heart rate, systolic blood pressure, and the product of heart rate and systolic blood pressure, with each of the five drugs--effects markedly different from those obtained with the placebo (P less than 0.01). These data show that noncardioselective (propranolol and oxprenolol) and cardioselective (practolol, metoprolol and tolamolol) agents, as well as drugs with intrinsic sympathomimetic activity (oxprenolol and practolol), were equally effective antianginal agents during sustained therapy. Furthermore, twice daily therapy with any of these drugs was effective in the management of patients with angina pectoris.

Comparison of the immediate effects of five beta-adrenoreceptor-blocking drugs with different ancillary properties in angina pectoris

We compared the immediate effects of five beta-adrenoreceptor-blocking agents in 16 patients with stable angina pectoris. Acute dose-response studies showed that all five drugs improved exercise tolerance and reduced ST-segment depression, heart rate and blood pressure by a similar degree in comparison with a placebo (P less than 0.01). Near maximum improvement in exercise tolerance occurred when the acute cumulative oral dose had reached 160 mg for propranolol and oxprenolol, 200 mg for metoprolol and tolamolol and 400 mg for practolol. When these drugs were administered as a single doses, increase in walking time before the development of angina and reduction in ST-segment depression, heart rate and systolic blood pressure all occurred within one hour and persisted for eight hours--effects markedly different from the response to a placebo (P less than 0.01). These data show that non-cardioselective agents (propranolol and oxprenolol), cardioselective agents (practolol, metoprolol and tolamolol), as well as drugs with intrinsic sympathomimetic activity (oxprenolol and practolol), were equally effective in the treatment of angina pectoris.

The effects of potassium supplements, spironolactone of amiloride on the potassium status of patients with heart failure

Extra potassium supplements, spironolactone or amiloride were given for 5 months to forty-nine patients with heart failure who were taking furosemide and were in a steady state. Plasma potassium increased with all three treatments but there was no significant increase in total body potassium or red cell potassium. These findings together with other studies suggest that patients with heart failure taking diuretics do not have a significant depletion of body potassium.

Potassium depletion in heart failure and its relation to long-term treatment with diuretics: a review of the literature

There have been many studies which suggest that patients with heart failure were potassium depleted. This depletion has been attributed to the use of potent diuretics, and these are now given with either potassium supplements or potassium-retaining diuretics. A detailed examination of the studies suggests that the reported decrease in body potassium compared with the results in healthy persons is not due to the diuretics. It can be partly explained by a failure to match patients and controls in terms of age, and the remaining difference can be explained by muscle wasting. There is therefore no evidence of a potassium depletion in these patients with heart failure.

Comparative anti-hypertensive effectiveness of beta-adrenoreceptor antagonists with different pharmacological properties: dose-response studies during acute and chronic administration

1. Immediate and long-term blood pressure-lowering activity of five beta-adrenoreceptor antagonists with different ancillary pharmacological properties were compared in a randomized double-blind placebo controlled factorial trial in twenty-five previously untreated patients with stable uncomplicated essential hypertension. 2. In doses which produced similar reductions in exercise tachycardia, all drugs exerted similar anti-hypertensive activity, which was greater on systolic than diastolic pressure and greatest during exercise. 3. These effects were maximum within an hour and lasted for over 8 h after a single oral dose. 4. Blood pressure-lowering activity, particularly the reduction in exercise systolic pressure, was significantly related to the logarithm of the dose of each drug. 5. Anti-hypertensive activity was maximally enhanced after 4 weeks of sustained treatment at any given dose. There was no short-term habituation to treatment and substitution with placebo resulted in a return of the blood pressure to pretreatment values within 4 weeks without subsequent overshoot. 6. The blood pressure-lowering activity of these drugs was predominantly related to their common property of competitive antagonism of cardiac beta-adrenoreceptors; their ancillary pharmacological properties, with the exception of intrinsic vasodilator activity, played little part in this response.

Effect of long-term diuretic treatment on body-potassium in heart-disease

Plasma and total body potassium have been measured in 151 patients with chronic heart-disease, 83 of whom were taking diuretics and potassium supplements. After allowance for age and body-size, the deficit in total body-potassium was only 3-5% (100-150 mmol) in the diuretic group. 13 of the 83 patients taking diuretic had hypokalaemia (less than 3-5 mmol/1) but the potassium deficit was no greater than in the patients with normal plasma-potassium. There was no relation between the dose of potassium supplements and either the plasma-potassium or the total body-potasium. It is suggested that potassium depletion is not a major problem in patients with heart-failure treated with diuretics. The dose of potassium supplements should therefore be determined entirely by the plasma-potassium.

Diurnal pattern of water and electrolyte excretion and body weight in idiopathic orthostatic hypotension. The effect of three treatments

The diurnal pattern of water and solute excretion and body weight were examined in five control subjects and in a patient with idiopathic orthostatic hypotension before and during treatment. The patient had a reversed diurnal pattern of excretion of sodium, urea and water but not of potassium and creatinine, and there was an excessive diurnal variation in body weight. The effects of three treatments, high salt diet alone and then with the addition of head-up tilt, and later fludrocortisone, were studied. Fludrocortisone caused marked clinical improvement and retention of sodium and water. Once a steady state was achieved none of the treatments had any significant effect either on the diurnal variation in weight or on the water and solute xcretion pattern except for a small reduction in sodium excretion at night when the patient slept with a head-up tilt. In is concluded that these treatments cause symptomatic improvement in idiopathic orthostatic hypotension through an increase in extracellular fluid volume rather than through any change in the abnormal diurnal pattern of water and salt excretion.

Comparison of antihypertensive activity of beta-blocking drugs during chronic treatment

The hypotensive activity of five beta-adrenoceptor antagonists with different ancillary pharmacological properties was compared in a randomised double-blind factorial trial in 25 untreated patients with stable, uncomplicated essential hypertension. In doses that produced similar reductions in exercise tachycardia all drugs had similar blood-pressure lowering activity, greater on systolic than diastolic pressure and greatest during exercise. With the exception of vasodilator activity the possession of any particular combinaton of ancillary pharmacological properties did not significantly influence the specific antihypertensive activity of these compounds.

A comparative study of the activity of beta-adrenoceptor antagonists in man

1. In healthy subjects the plasma concentration of unchanged drug, heart rate response to excerise and attenuation of isoprenaline tachycardia were maximal at one hour after ingestion of a range of doses of propranolol, oxprenolol, practolol, tolamolol, atenolol and metoprolol. 2. There was a within-drug relationship between plasma concentration of unchanged drug and the attenuation of exercise and iosprenaline tachycardia. There was no similar between-drug relationship. 3. There was a similar exponential relationship between oral dose and reduction of exercise tachycardia for all six drugs. 4. The linear relationship between oral dose and antagonism of infused isoprenaline was significantly greater for oxprenolol and propranolol than for the other four drugs. 5. "Cardioselective" activity was the only ancillary pharmacological property which differentiated the activity of these drugs in normal subjects.