Nocturnal hypoxemia and associated electrocardiographic changes in patients with chronic obstructive airways disease

To study the direct effects of nocturnal hypoxemia on the heart, we recorded electrocardiographic tracings and arterial oxygen saturation (SaO2) during the night in patients with chronic obstructive airways disease. In seven "blue-bloater" patients the mean basal SaO2 was less than 80 per cent, and it fell by more than 10 per cent during 29 episodes of transient hypoxemia. Only five such episodes occurred in three of five "pink-puffer" patients. All "blue bloaters" with low basal mean SaO2 had multiple atrial and ventricular premature contractions and a high heart rate at rest; six patients has a prolonged QTc, three had ST-T depression, and one had right-bundle-branch block. Oxygen therapy increased basal mean SaO2, reduced ectopic activity, abolished ST-T changes and bundle-branch block, significantly reduced the resting heart rate and the amplitude of the R and S waves, and shortened the QTc in four nonsmokers. These results suggest that sustained hypoxemia contributes to myocardial dysfunction and heart failure in "blue-bloater" patients.

Comparison of antianginal efficacy of one conventional and three long acting beta-adrenoreceptor blocking agents in stable angina pectoris

We compared the antianginal efficacy of one conventional and three long acting beta-adrenoreceptor blocking agents in a randomised manner in 12 patients with stable angina pectoris. An exercise test was performed initially and in the 24th hour after a single daily dose of 160 mg of each beta-blocker at the end of a two week treatment period. In addition, glyceryl trinitrate consumption, anginal attack rate, and activity scores were recorded. No titration studies to an equivalent degree of beta-blockade were undertaken; a fixed dose was used even though these drugs are not equipotent. Conventional propranolol in a single daily dose of 160 mg was as effective in controlling the frequency of anginal attacks as long acting propranolol and sustained release oxprenolol. Exercise tolerance was less with sustained release oxprenolol than with conventional propranolol, long acting propranolol, and nadolol. Nadolol produced a significantly greater reduction in exercise-induced tachycardia than did long acting propranolol, sustained release oxprenolol, and conventional propranolol, and also the lowest anginal attack rate, the lowest trinitrin consumption, and significantly less ST segment depression than the other three. These findings suggest that nadolol is more potent than long acting propranolol, sustained release oxprenolol, and conventional propranolol, and the antianginal benefit at the 24th hour relates to the degree of beta-adrenoreceptor blockade achieved.

Evidence for inhibitory and anti-ouabain-like factors in leukaemic blood

1. At a high dilution in Ringer solution (1:200), leukaemic plasma significantly (P less than 0.05) decreased the ouabain-sensitive and increased ouabain-insensitive components of sodium efflux from erythrocytes. At a low dilution (1:10) leukaemic plasma predominantly decreased the total and ouabain-insensitive component of sodium efflux (P less than 0.01). 2. Erythrocytes from patients with leukaemia had a high affinity for the plasma factor which inhibited the total and ouabain-insensitive efflux (inhibitory factor). 3. Washings of leukaemic erythrocytes which had been incubated in leukaemic plasma contained a factor which significantly decreased the ouabain-sensitive and increased ouabain-insensitive components of sodium efflux (the anti-ouabain-like factor). 4. These studies show that leukaemic blood contains two factors which have opposite effects on sodium efflux from erythrocytes. These factors may contribute to the high incidence of multiple electrolyte disturbances in acute myeloid leukaemia.

Response of ectopic prostatic ACTH production to metyrapone

A case of ectopic prostatic ACTH production exhibiting a good response to metyrapone is reported.

Lysozyme and hypokalaemia

Serum potassium, lysozyme and urinary lysozyme measurements were made in 98 patients with tuberculosis, 18 with sarcoidosis and 30 with acute myeloid leukaemia. Serum K concentration fell below 3·5 mmol/l in 17 of the 30 leukaemic patients and only 7 of these had raised serum lysozyme concentrations. None of the patients in the tuberculosis-sarcoidosis group with lysozymaemia or lysozymuria developed hypokalaemia. This study suggests that raised lysozyme concentrations are not causally related to hypokalaemia.

Usefulness of serum lysozyme measurement in diagnosis of intrathoracic lymphadenopathy

We studied the value of serum lysozyme as a helpful test in distinguising tuberculous involvement of intrathoracic glands from lymphoma. Nineteen of the 28 patients (all Asian immigrants) with intrathoracic glandular tuberculosis had raised serum lysozyme level as compared with 2 of the 29 patients with lymphoma. While a normal serum lysozyme level is unhelpful, a raised level in an Asian immigrant with hilar or mediastinal lymphadenopathy makes tuberculosis a highly probable diagnosis.

Aplastic anaemia: an analysis of 174 patients

The authors summarize their experience with 174 patients with aplastic anaemia (AA) with particular reference to course, prognostic factors, conversion to other blood disorders, treatment and outcome. Aplastic anaemia was defined as pancytopenia and a hypocellular marrow at some time during the illness. Seven patients terminated with acute leukaemia, 8 developed haematological features of sideroblastic anaemia and 5 showed a red cell membrane defect commonly found in paroxysmal noctural haemoglobinuria. Complete recovery occurred in only 4 patients; 70 others showed a partial remission with some residual haematological abnormality in peripheral blood. Eighteen of these had spontaneous remission. Remission was brief in 27 patients who died; only 32 patients remained in partial remission. Twenty-five per cent. of the patients with AA run an acute course and die within 6 months of the time of diagnosis. The remainder run a subacute or chronic course, punctuated in some cases by a transient remission, but in others by a conversion to other related haematological disorders. An acute course is suggested by a rapid onset of symptoms, a falling neutrophil count, a haemoglobin level less than 5 g/dl and a very low platelet count. A chronic course is likely in those patients who have a slow onset of symptoms, a stable neutrophil count and a Hb level in excess of 5 g/dl. The authors' experience shows that the disease runs either of the 2 courses irrespective of the supportive therapy.

Metabolic disorders in acute myeloid leukaemia

Metabolic balance studies were carried out in 17 unselected patients with acute myeloid leukaemia. Widespread metabolic disturbances were observed. Serum Na fell below 135 mmol/1 in 14 patients (82%) and 11 patients (64%) developed hypokalaemia. An increased osmolal clearance caused by a release of electrolyte and blast cell waste (i.e. urea, urate, etc.) during chemotherapy appeared to be the principle cause of natriuresis and hyperkaluria. Seven patients had proteinuria before and eight others developed it during antileukemic therapy. Nine patients (53%) developed proximal renal tubular dysfunction with aminoaciduria, hyperphosphaturia and incomplete reabsorption of urate. No significant relation was found between this widespread glomerulo-tubular dysfunction and lysozymuria. We suggest that antileukaemic drugs release unidentified substances from blast cells which are toxic to the kidney. Metabolic alkalosis in six patients (35%) was probably related to volume depletion and hypokalaemia, while two patients developed acidaemia with the onset of renal failure. Hypocalcemia in seven patients (41%) had a multifactorial basis: hyperphosphaturia, septicaemia, malnutrition and cytotoxic drugs were among the probable causes.

Evidence for non-infiltrative cardiomyopathy in acute leukaemia and lymphoma. A clinical and echocardiographic study

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Regional lymph gland biopsy in tubercular synovitis of the knee

One hundred patients with proved tubercular synovitis of the knee were studied and 50 patients underwent inguinal lymph node biopsy. Results for and experience with lymph node biopsy in tubercular synovitis of the knee are presented.

Hypoimmunoglobulinaemia and aplastic anaemia

Serum immunoglobulin levels were estimated in 19 patients with aplastic anaemia. Although the mean levels for IgG, IgA and IgM for the group as a whole were within the normal range, 8 individual cases showed low levels of one or more immunoglobulin class, suggesting a disturbance in immunoglobulin production. One of these patients had a thymoma, and another positive tests for anti-nuclear factor, but there was no evidence of auto-immune disease in the others. It is suggested that 'aplastic anaemia' may sometimes be a disease due to injury of a stem cell subserving both haemopoietic and immunological function.

Lysozyme: a brief review

Serum lysozyme (muramidase) estimation is a simple, convenient and useful laboratory investigation. A review of the literature shows that lysozyme has been implicated as an aetiological factor in various disorders, and credited with being a prognostic indicator in acute myeloid leukaemia, but these promises have not been fulfilled. This low molecular weight protein is found in the urine of some patients with renal tubular disorders, but some workers have emphasized its importance as a causal agent in hypokalaemia of acute myeloid leukaemia. Research should be concentrated on muramidase as an expression of cell functions rather than as an aetiological factor. Hypokalaemia in acute myeloid leukaemia may be caused by an unidentified substance of molecular weight similar to that of lysozyme.

Altered membrane sodium transport and the presence of a plasma ouabain-like inhibitory factor in acute myeloid leukaemia

1. Sodium transport studies were performed in erythrocytes from normal subjects and from patients with acute myeloid leukaemia. Sodium influx and efflux rates were increased in erythrocytes from leukaemic patients. 2. The ouabain-sensitive component of sodium efflux was increased in leukaemic erythrocytes. 3. The high sodium efflux from leukaemic erythrocytes was decreased when the incubation media contained leukaemic plasma, suggesting the presence of an ouabain-like factor in the plasma. Paired experiments failed to show the presence of a similar factor in normal plasma. 4. Leukaemic erythrocytes showed a significantly greater ouabain uptake than the normal cells. 5. The results are discussed in relation to the wide-spread electrolyte disturbances in acute myeloid leukaemia.

A new translocation associated with the Ph1 chromosome and an acute course of chronic granulocytic leukaemia

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