Antibodies to human platelet antigens form a significant proportion of platelet antibodies detected in Indian patients with refractoriness to platelet transfusions

BACKGROUND

The transfusion of platelets is an important therapeutic strategy in bleeding patients with thrombocytopenia. However, some chronically transfused patients fail to achieve the appropriate platelet count increment following transfusion due to the presence of platelet alloantibodies.

OBJECTIVES

The aims of this research were to study the prevalence of platelet alloimmunisation and to characterise the platelet-reactive (PR) antibodies in haematology patients refractory to platelet transfusions in an Indian setting.

PATIENTS AND METHODS

A total of 80 patients with a prior history of multiple transfusions (minimum of five cellular transfusions) were included in the study if they did not achieve an adequate corrected count increment within 24 h of the platelet transfusion. Patients with non-immunological causes of platelet refractoriness were excluded from the study. The test was performed on a blood sample of 4 mL of Ethylenediaminetetraacetic acid (EDTA) blood sample in which plasma was separated and stored at -80 °C and underwent batch testing in PAK-2LE.

RESULTS

The overall prevalence of platelet alloimmunisation in our study was 60%. Of the 48 patients who were detected to have platelet antibodies, the combination of anti-human leucocyte antigen (HLA) and platelet-specific (PS) antibodies together constituted the majority of 54·2%. The overall prevalence of anti-HLA antibodies was 51·25% and of PS antibodies was 41·25% in the total study population of 80.

CONCLUSION

The overall prevalence of PS antibodies in our study was greater than that reported by other groups in India and other countries. This needs to be considered, particularly in the management of patients refractory to platelet transfusions, where HLA-matched platelets constitute current best practice.

Valvular dysfunction in antiphospholipid syndrome: prevalence, clinical features, and treatment

Valvular abnormalities develop in 36% and 35% of patients with primary antiphospholipid syndrome (PAPS) and with systemic lupus erythematosus (SLE) respectively, and in 48% of patients with SLE and antiphospholipid antibodies (aPL). Valvulopathy includes leaflet thickening, vegetations, regurgitation, and stenosis. A literature survey shows that significant morbidity from valvular dysfunction, mostly mitral regurgitation leading to congestive heart failure, occurs in 4% and 6% of SLE and PAPS patients, respectively. The pathogenesis of valvulopathy may involve interaction of aPL with antigens on the valve surface, resulting in valvulitis. Current therapy includes symptomatic measures and valve replacement. A novel approach for symptomatic antiphospholipid syndrome (APS) related valvulopathy involves treatment with systemic corticosteroid. We describe four such patients and their dramatic clinical and hemodynamic response to treatment with prednisone when symptomatic measures failed.

Polyarteritis nodosa and drug abuse: is there a connection?

Drug abuse has been controversially linked to polyarteritis nodosa. A 28-year-old man with a history of drug abuse with inhaled heroin presented with an enigmatic illness consisting of refractory fever, bilateral pleural effusions, migratory polyarthritis, and a leukaemoid reaction. An abdominal angiography confirmed the diagnosis of polyarteritis nodosa, and treatment with both prednisone and cyclophosphamide resulted in significant clinical and laboratory improvement.

Salmonella mycotic aneurysm of the aortic arch: case report and review

Salmonella mycotic aneurysms of the thoracic aorta are exceedingly rare. We describe what we believe is only the third reported case involving the aortic arch. The patient was treated with surgical intervention and a prolonged course of antibiotics, which resulted in long-term survival. We review 13 previously reported cases of salmonella mycotic aneurysms of the thoracic aorta. The overall outcome was abysmal, with 10 of 13 patients dying within 1 month after the diagnosis was made. We discuss the pathogenesis, clinical presentation, diagnostic approach, and management (including surgical intervention and duration of antibiotic therapy) of this condition on the basis of the findings in these cases.

A prospective randomized trial of intravenous magnesium versus intravenous propranolol in acute myocardial infarction

A total of 266 patients entered into a study comparing the effect of intravenous magnesium and propranolol following acute myocardial infarction. Of these, 97 were able to receive either drug and were therefore randomized into the magnesium (n = 51) or propranolol group (n = 46). 88 patients were unable to receive propranolol and formed a third group (NR) while a further 81 patients could not receive either drug and formed a fourth group (N). The study showed that intravenous magnesium was as effective in preventing potentially lethal arrhythmias as propranolol and could be given to some 70 per cent of such patients whereas propranolol could only be given to 36 per cent.

Long-term follow-up after acute myocardial infarction in patients randomized to treatment with intravenous magnesium or intravenous propranolol in the acute phase

Ninety-five patients with acute myocardial infarction were followed up for 6 months to 3 years (mean 25.4 months) in a preliminary study to compare the effects of intravenous magnesium (49 patients) with that of intravenous propranolol (44 patients) given immediately after admission to the intensive care unit. There were four cardiac deaths in the propranolol group and no deaths in the magnesium group (P < 0.046) and 27 per cent of patients who received propranolol subsequently developed cardiac failure as opposed to 12 per cent of those who had received magnesium (P < 0.04). Intravenous magnesium given in the early stages of myocardial infarction reduces the subsequent cardiac death rate possibly by reducing infarct size.

Progression and regression of coronary artery disease in one year. Quantitative angiographic assessment in patients with stable angina pectoris

The rate of progression of coronary artery stenoses (CAS) is not clear. Spontaneous regression may also occur. Seventy-one CAS in 25 patients who were enrolled in a study of the effects of chromium on CAS were analysed. Coronary angiography was performed in multiple views and patients randomised to chromium or placebo treatment. Videodensitometric quantitative analysis was performed using a Vanguard XR70 Analyzer. After 1 year all patients were recatheterised. Corresponding frames from identical views were analysed. CAS were assessed with the observers blinded to the initial study results. No differences were found between chromium or placebo and the results have been combined. There was no overall progression of CAS as assessed by % area stenosis (p = 0.65), % diameter stenosis (p = 0.19), stenotic area (p = 0.87), or stenotic diameter (p = 0.99). However, 20% of individual lesions progressed, while 10% regressed, and 70% remained the same. These changes must be taken into account in studies of interventions which may modify the course of coronary atherosclerosis, and if coronary by-pass surgery is to be performed with a 1 year delay after angiography.

An unusual case of Q fever endocarditis

We describe a patient with unusual features of Q fever endocarditis. The unusual features of this case were the presence of an abscess surrounding the involved aortic valve and the appearance of circulating anticoagulants in the patient's serum.

Brucellosis with nephrotic syndrome, nephritis and IgA nephropathy

A patient with systemic brucellosis due to Brucella melitensis had severe renal involvement. Clinical features included hypertension, macroscopic haematuria, massive proteinuria of 10 g per 24 hours and azotaemia. Following treatment with antibiotics, the azotaemia resolved and proteinuria decreased to less than 0.5 g per 24 hours, but microscopic haematuria and hypertension persisted. Renal biopsy during recovery revealed IgA nephropathy with minimal mesangial changes, suggesting a causal relation between brucellosis and IgA nephropathy with a reversible nephrotic syndrome.

Serum and mononuclear cell potassium, magnesium, sodium and calcium in pregnancy and labour and their relation to uterine muscle contraction

Thirty women in their third trimester of pregnancy (37-42 weeks), 40 women during and 72 h after labour and 18 non-pregnant controls were studied for changes in serum and mononuclear cell cation content, and their relationship to cervical effacement and intensity of pain as measured by plasma beta endorphin concentrations during labour. Serum magnesium fell from 0.95 +/- 0.01 (mean +/- SEM) to 0.84 +/- 0.02 mmol/litre at late pregnancy and further to 0.76 +/- 0.01 during labour (P < 0.001); serum potassium fell from 4.25 +/- 0.05 to 3.79 +/- 0.06 mmol/litre (P < 0.0001) during labour; and serum calcium fell from 2.40 +/- 0.02 to 2.28 +/- 0.01 mmol/litre at late pregnancy (P < 0.001) and further to 2.25 +/- 0.02 mmol/litre during labour (P < 0.001). Mononuclear cell magnesium content rose from 4.5 +/- 0.3 to 5.6 +/- 0.04 fmol/cell (P < 0.02); potassium content rose from 37.7 +/- 2.0 to 50.9 +/- 3.0 fmol/cell (P < 0.001); and calcium content rose from 4.4 +/- 0.4 to 7.6 +/- 1.1 fmol/cell (P < 0.105). On the other hand, mononuclear cell sodium content fell from 7.2 +/- 0.5 to 3.8 +/- 0.3 fmol/cell (P < 0.001). Plasma beta endorphin concentrations increased with increasing degrees of effacement, as did intracellular Na, whereas intracellular Mg and K showed an inverse trend. A significant correlation was found between intracellular cation and beta endorphin levels (r = -0.98, Mg; -0.99, K; 0.83, Na). These changes are probably due either to intercompartmental cation shifts or possibly to endometrial ischaemia and damage during labour.

The effects of chromium supplementation on serum glucose and lipids in patients with and without non-insulin-dependent diabetes

Seventy-six patients with established atherosclerotic disease were treated daily with either 250 micrograms of chromium orally as chromium chloride or a placebo for a period of 7 to 16 months (mean, 11.1 months). Serum chromium increased from 2.69 +/- 0.09 to 12.12 +/- 0.77 nmol/L (mean +/- SE, P less than .005). Serum triglycerides were lower (1.68 +/- 0.11 and 2.10 +/- 0.14 nmol/L, respectively; P less than .02) in the chromium-treated patients than in the patients who received placebo, and serum high-density lipoprotein (HDL) increased (from 0.94 +/- 0.05 to 1.14 +/- 0.07 mmol/L, P less than .005) in the patients who received chromium. There was no change in serum cholesterol or blood glucose during the study.

Effects of hydrochlorothiazide, diltiazem and enalapril on mononuclear cell sodium and magnesium levels in systemic hypertension

Sixteen patients (mean age 68 years) with mild to moderate hypertension were treated with either diltiazem or hydrochlorothiazide for 6 weeks, followed by enalapril for a further 6 weeks. A second group of 40 patients (mean age 71 years) was treated with either hydrochlorothiazide or enalapril for 12 weeks; nonresponders received both drugs for 8 weeks. Treatment with hydrochlorothiazide or enalapril resulted in a lowering of systolic and diastolic blood pressures, but diastolic pressure was lower in patients treated with enalapril (89 +/- 2 and 82 +/- 2 mm Hg, respectively; p less than 0.05). Treatment with diltiazem resulted in a decrease in diastolic pressure only. Treatment with hydrochlorothiazide resulted in a 17% decrease in serum potassium (p less than 0.05), which returned to normal when enalapril was substituted. Hydrochlorothiazide also produced a 23% decrease in mononuclear cell sodium content at 4 weeks (p less than 0.01), with a further 15% decrease at 12 weeks (p less than 0.05). Mononuclear cell potassium and magnesium also decreased at 12 weeks by 18 and 16%, respectively (p less than 0.05). All these effects were reversed when enalapril was substituted. A similar pattern of events was seen with diltiazem, which was again reversed with enalapril. Finally, there was no relation between changes in mononuclear cell sodium or other cation content and changes in blood pressure.

The rise of serum creatinine levels during labor

Serum creatinine, blood urea nitrogen and creatine phosphokinase were measured in 32 women during the last 3 weeks of pregnancy and, in a further 39 women, during and after labor. The serum creatinine increased from 61.9 +/- 0.9 to 69.8 +/- 1.8 mumol/l (mean +/- SEM) (P less than 0.05) in the third stage of labor and returned to normal by 72 h after delivery. The muscle creatine phosphokinase increased from 54 +/- 7 to 77 +/- 9.9 units (P less than 0.05) during the third stage and remained high (87 +/- 13.3 units) 72 h later. We conclude that these changes are due to muscle contraction and injury during delivery.

Serum and intracellular electrolytes in patients with and without pain

The effect of acute stress, with and without pain, on serum and mononuclear cell cation content was studied in 205 healthy women in their last trimester of pregnancy or during normal labour, in patients with acute medical conditions in which pain was or was not present, in acute surgical conditions, and immediately prior to elective surgery. In all subjects there was a fall in serum sodium, potassium, magnesium and calcium concentrations during stress, with an apparent shift into the intracellular space. An inverse correlation was present between the severity of pain and the fall in serum cations.

Chromium and cholesterol-induced atherosclerosis in rabbits

Thirty-three rabbits on a cholesterol-enriched diet were randomized into 6 groups and treated with daily injections of either water, 20 micrograms of potassium chromate or 1, 5, 10 or 20 micrograms of chromium chloride, respectively, for 135 days with a 2- to 10-fold increase in serum chromium. There was a marked reduction in the percentage of aortic intimal surface covered by plaque, in aortic weight and cholesterol content in the treated animals. Rabbits treated with 20 micrograms of chromium chloride showed a better response than those treated with either 10 or 20 micrograms of potassium chromate.

The relationship between beta-endorphin levels and uterine muscle contractions during labor

Plasma beta-endorphin (BE) levels (8.6 +/- 0.8 pmol/l) (mean +/- SE) were lower in the third trimester than in non-pregnant controls (14.8 +/- 1.1 pmol/l) (P less than 0.001), increased during labor, to 29.3 +/- 4.4 pmol/l (P less than 0.005) and decreased, 72 h after delivery, to 3.5 +/- 0.4 pmol/l (P less than 0.001). BE levels were found to correlate significantly with uterine muscle contraction (r = 0.966, P less than 0.05) and with cervical effacement (r = 0.974, P less than 0.05) during labor.

A routine method for the measurement of the sodium, potassium, magnesium and calcium content of human lymphocytes

We describe a rapid, single-step procedure for the isolation of human lymphocytes from whole blood, suitable for a routine clinical laboratory. Lymphocyte content of sodium, potassium, magnesium and calcium were measured simultaneously in a group of controls and found to fall within expected ranges. Expression of results per mg protein produced less inter-individual variation than per unit cell. In order to examine another, physiologically different but normal population, women during pregnancy were also studied. The cation content of lymphocytes expressed per mg protein was significantly lower than for controls due to a 44% increase in protein content per cell.

Potassium and magnesium status in ischaemic heart disease

This paper summarizes the evidence that magnesium and potassium ions play a vital role in the generation of ventricular tachyarrhythmias in patients with acute myocardial infarction. In particular, the protective role of magnesium is stressed. Patients with acute myocardial infarction treated prophylactically with magnesium intravenously for the first 24 hours after admission have a much lower incidence of potentially fatal tachyarrhythmias and a low in-hospital mortality. The role of intracellular cation measurements in defining prognosis after acute myocardial infarction is also discussed as is the effect of diuretic therapy.

Factitious injury of an extremity: a Munchausen variant

Self-induced injury of one or more of the extremities may represent a distinct variety of Munchausen syndrome. The nature of the injury may be infectious, dermatologic or orthopedic. The mechanism may be secondary gain or another unconscious motivation that causes a craving for attention. In many cases, the underlying psychopathology is personality disorder.

Influence of chronic diuretic therapy on serum, lymphocyte and erythrocyte potassium, magnesium and calcium concentrations

Serum, lymphocyte and erythrocyte potassium, magnesium and calcium concentrations were measured in 31 patients with congestive cardiac failure and 14 patients with mild noncomplicated hypertension, who had been receiving either furosemide or chlorothiazide (with or without potassium supplementation) or a combination of hydrochlorothiazide and amiloride for more than 6 months. Lymphocyte potassium concentrations (pmol/100 cells +/- SE) were as follows: controls 18.1 +/- 1.5, furosemide 14.1 +/- 0.9 (p less than 0.001), furosemide + potassium 12.3 +/- 0.7 (p less than 0.001), chlorothiazide 13.1 +/- 1.0 (p less than 0.001) and hydrochlorothiazide + amiloride 18.6 +/- 0.7 (p = NS). There was a statistically significant relationship between the number of months the patients had been on diuretics and their lymphocyte potassium concentrations. Serum electrolytes, apart from the group receiving chlorothiazide who showed a significant fall in serum K, were unchanged.

Magnesium therapy for acute myocardial infarction

Acute myocardial infarction carries a high risk of potentially fatal ventricular arrhythmias during the first 24 hours after the infarct. At this time there is an efflux of K and Mg ions from the injured cells with an associated rise in these cations in the lymphocytes of the peripheral blood. There is a close association between these arrhythmias and the levels of these cations, with a high K level associated with an increased incidence of arrhythmias and a high Mg level being associated with a protective effect. Treatment with a continuous infusion of Mg is highly effective in the prevention of these arrhythmias resulting in a fall in inhospital mortality.

Effects of enalapril on lymphocyte sodium, potassium, magnesium and calcium levels in patients with severe congestive heart failure

Fifteen patients (median age 73 years) with severe congestive heart failure were treated with Enalapril for a total of 12 weeks with a significant improvement in their right atrial pressures and in their functional state. Renal function, serum potassium, magnesium and calcium levels were unchanged. Lymphocyte sodium, potassium and calcium levels were generally lower than control values throughout the study but these differences were only statistically significant early in the study. Lymphocyte magnesium levels were unchanged. These findings are in contrast to those previously reported in the literature for such patients treated with conventional diuretics.

Lymphocyte potassium and magnesium concentrations as prognostic factors after acute myocardial infarction

215 patients admitted with acute myocardial infarction were prospectively evaluated for prognostic factors. When lymphocyte potassium concentration increased by up to twofold of normal, a high lymphocyte magnesium concentration was associated with a good prognosis. However, when the increase in lymphocyte potassium concentration was greater than twofold, the presence of a high lymphocyte magnesium made no difference to mortality. Age, the female sex, anterior wall infarction, high serum enzymes, heart failure, diabetes mellitus in females and serious arrhythmias were all bad prognostic signs.

The effect of prolonged treatment with differing doses of chromium on glucose homeostasis in rabbits

The effect of prolonged treatment with chromium on glucose homeostasis was assessed in rabbits. Thirty-one male rabbits were divided into 6 groups. All were fed for 30 days with a standard ad libitum diet. Twenty-seven rabbits were injected daily during a further 120 days with different doses of potassium chromate (3-20 micrograms) while 4 rabbits served as controls. No significant rise in serum glucose levels was observed, insulin levels were the same in the different groups, and glycosylated hemoglobin concentration also did not change after the administration of chromium. Serum chromium levels increased proportionally to the dose injected to an almost a 14 fold increase in the 20 micrograms chromium treated group. Although others have shown that chromium may have a hyperglycemic effect with inhibition of insulin secretion, we have not been able to confirm this finding.

Magnesium in the prevention of lethal arrhythmias in acute myocardial infarction

Seven of 48 patients (14.6%) with acute myocardial infarction who were given 2.4 g of magnesium sulfate as a single intravenous dose had potentially lethal arrhythmias during the first 24 hours after admission, whereas 16 (34.8%) of 46 patients receiving placebo had similar arrhythmias. In addition, 14 of these 16 patients in the placebo group had their first arrhythmia (in the intensive coronary-care unit) within two hours after the start of the study, whereas in the magnesium-treated group, there were no such arrhythmias until some four hours later. The higher the lymphocyte potassium concentration, the greater the reduction in the incidence of arrhythmias. Serum magnesium levels increased by 16.5% and lymphocyte magnesium concentrations by 72% in the magnesium treated group. Intravenous magnesium reduces the incidence of serious arrhythmias after acute myocardial infarction.

Serum, lymphocyte, and erythrocyte potassium, magnesium, and calcium concentrations and their relation to tachyarrhythmias in patients with acute myocardial infarction

Serum, lymphocyte, and erythrocyte potassium, magnesium, and calcium levels were measured in 215 patients during the five days following acute myocardial infarction. Serum potassium fell from 4.25 +/- 0.05 to 4.08 +/- 0.06 mmol/liter (p less than 0.001), magnesium from 0.93 +/- 0.01 to 0.85 +/- 0.01 mmol/liter (p less than 0.001), and calcium from 2.4 +/- 0.02 to 2.2 +/- 0.08 mmol/liter (p less than 0.001). Lymphocyte potassium increased from 18.1 +/- 1.5 to 51.6 +/- 4.3 pmol/100 cells (p less than 0.001) and magnesium from 2.0 +/- 0.1 to 8.2 +/- 0.8 pmol/100 cells (p less than 0.001), whereas calcium decreased from 2.9 +/- 0.27 to 1.4 +/- 0.25 pmol/100 cells (p less than 0.001). Erythrocyte cations remained constant. There was a larger increase in lymphocyte potassium in patients with tachyarrhythmias than in patients without (70.4 and 46.9 pmol/100 cells, respectively, p less than 0.001), whereas the presence of a high lymphocyte magnesium level was associated with a significant decrease in the development of tachyarrhythmias, despite high potassium concentrations. It is suggested that lymphocyte cation concentrations mirror myocardial interstitial concentrations and that a high interstitial magnesium level has a protective effect on the increased cell excitability due to, and despite, a high interstitial potassium level.

Intracellular cations and diuretic therapy following acute myocardial infarction

In a controlled, prospective, randomized study of the effects of diuretic therapy on serum, lymphocyte, and erythrocyte potassium, magnesium, and calcium concentrations, 155 patients were followed up for six months after experiencing acute myocardial infarction. Of these, 48 patients received furosemide and potassium; 37 patients received hydrochlorothiazide and amiloride hydrochloride; and 70 patients did not require diuretics. Lymphocyte and erythrocyte cation concentrations were all statistically significantly lower in the furosemide-treated patients when compared with the patients in the nondiuretic-therapy group or the hydrochlorothiazide-amiloride-treated group, with no change in serum levels. Since the combination of low intracellular potassium and magnesium concentrations in patients with recent myocardial infarction may be of importance in the cause of arrhythmias, we suggest that potassium- (and magnesium-) sparing diuretics be used in the treatment of patients, when necessary, unless their diuretic needs cannot be met by such agents.

Effect of amiodarone on blood lipids

Amiodarone is a potent antiarrhythmic drug with a prolonged half life. The administration of amiodarone for 6 weeks in rabbits caused a significant elevation of serum lipids. We measured serum lipoproteins in 24 patients before, 30 and 90 days after treatment with amiodarone. Serum triglycerides decreased for all patients from 140.1 +/- 11.6 to 122.7 +/- 10.2 (p less than 0.05) whilst total cholesterol decreased from 211.4 +/- 19.5 to 194.4 +/- 13.3 (p = 0.08) in female patients only. There was no change in high density lipoprotein concentrations. These data are in contrast to those found in rabbits and are probably due to the smaller doses of amiodarone used on our patients.

Digoxin treatment and control in the elderly

The efficacy and the risk of toxicity of long-term digoxin therapy were assessed in 81 elderly patients. The findings show that the serum digoxin level did not correlate with the clinical state. Only 47% of the patients were on a dosage considered to be effective by serum digoxin analysis, whereas 38% of the patients had levels below the therapeutic range; 51% of the patients had been treated with pediatric or semipediatric doses only. Electrocardiographic evidence of digoxin toxicity was found in 17%. Routine periodic measurement of serum digoxin did not correlate with better management. The optimum dosage of digoxin in the elderly patient who is not in overt renal failure and who is not particularly underweight would seem to be 0.19 mg/day, i.e., one and one-half tablets of 0.25 mg on alternate days.

Reversible cholestatic jaundice and hyperamylasaemia associated with captopril treatment

Images

Correlation between manifestations of digoxin toxicity and serum digoxin, calcium, potassium, and magnesium concentrations and arterial pH

In 18 patients with gastrointestinal manifestations of digoxin toxicity the mean serum digoxin concentration (+/- SEM) was 3.16 micrograms/l (+/- 0.25), the calcium to potassium ratio 0.31 (+/- 0.01), and the mean arterial pH 7.406 (+/- 0.017). In contrast 19 patients with digoxin induced automaticity had a mean serum digoxin concentration of 1.24 micrograms/l (+/- 0.15; p less than 0.001), a calcium to potassium ratio of 0.38 (+/- 0.01; p less than 0.01), and an arterial pH of 7.498 (+/- 0.008; p less than 0.001). Eight out of 13 patients with digoxin induced cardiotoxicity had serum concentrations of the drug within the therapeutic range (0.8-2.0 micrograms/l). The calcium to potassium ratio, however, was lower than in the patients with automaticity (0.31 +/- 0.02; p less than 0.01) and the arterial pH was 7.370 (+/- 0.033; p less than 0.05). Serum magnesium concentrations were similar in all groups. In this study patients with digoxin induced gastrointestinal symptoms had high serum concentrations of the drug, whereas those with drug induced automaticity had therapeutic concentrations. This second group, however, was identified by their higher calcium to potassium ratios and higher pH values.

The action of chromium on serum lipids and on atherosclerosis in cholesterol-fed rabbits

Eight rabbits, fed on a 1% cholesterol diet for 30 days, were injected daily with potassium chromate for a further 60 days. A 50% reduction in aortic intimal plaque area and in aortic total cholesterol content was observed. However, although levels of serum cholesterol and triglycerides were consistently lower and levels of high density lipoprotein fractions consistently higher in the chromium-treated as compared to the control rabbits, these differences did not reach statistical significance. A further 6 rabbits were injected with potassium chromate and fed on a 1% cholesterol diet for 12 weeks. Mean aortic cholesterol content (+/-SEM) was 40.23 mg/10 cm aortic length (+/-7.50) as compared to 66.24 mg/10 cm (+/- 7.89) in a control group (P less than 0.05), whereas the area of aortic intima covered by macroscopic plaques was 67.5% (+/-2.79) and 81.1% (+/-3.14) (P less than 0.01) respectively.

The effect of chromium on cholesterol-induced atherosclerosis in rabbits

Rabbits fed on a 1% cholesterol diet for 30 days were injected daily with potassium chromate for a further 60 days. A 50% reduction in aortic intimal plaque area and in aortic total cholesterol content was observed. Control rabbits treated with chromium showed a significant increase in the chromium concentration of their aortas, liver and kidneys but not of the myocardium. Cholesterol-fed rabbits treated with chromium showed a significant increase in chromium concentrations in the liver and kidneys only. Serum cholesterol levels were consistently lower in the chromium-treated animals, although the differences did not reach significant levels.

Hypertransaminasemia with subcutaneous heparin therapy

An elevation of serum aspartate aminotransferase (GOT) and alanine aminotransferase (GPT) may be produced in patients treated with i.v. full-dose HEPARIN. We studied the influence of low-dose s.c. HEPARIN (5,000 IU X 2) in 34 patients with acute myocardial infarction (AMI) and in 7 with cerebrovascular accidents or calf thrombophlebitis. Twelve patients (all males) with AMI showed a secondary elevation of GOT and GPT at about the sixth or seventh day after the commencement of therapy that persisted throughout the period of treatment. Four patients (two males and two females) with cerebrovascular accidents or thrombophlebitis showed similar increases of GOT and GPT.

Changes in the magnesium content of tissues following myocardial damage in rats

The magnesium content of blood, heart and striated muscle, liver, spleen, kidney and bone was determined in rats, 15, 30 and 60 minutes, 6 and 24 hours after isoprenaline induced myocardial damage. The magnesium concentration increased significantly in the serum (but not in the red cells) in the first three groups of animals, while the magnesium concentration of heart muscle fell in all groups. There was no evidence of magnesium flux in the other tissues.

Serum chromium and ageing

Serum chromium levels were measured in 81 subjects (56 males and 25 females) with a mean age of 54 years (range 22-91 years). The mean serum chromium level in those under the age of 60 years was 1.6 +/- (SE) 0.125 ppb (30.7 +/- 2.4 nmol/l) whereas in those over the age 60 years it was 1.9 +/- 0.195 ppb (36.5 +/- 3.7 nmol/l). There was no evidence of any change in serum chromium levels with increasing age (r = 0.0096; p greater than 0.1) when all the subjects were considered. However, amongst the males a small but definite increase in serum chromium from 1.5 +/- 0.135 ppb (28.8 +/- 2.6 nmol/l to 2.1 +/- 0.25 ppb (40.6 +/- 4.8 nmol/l) was demonstrated.

The effect of chromium on established atherosclerotic plaques in rabbits

Twenty-three rabbits were fed for 8 weeks with standard diet to which was added a 1.5% cholesterol supplement. After this the cholesterol supplement was discontinued, but 11 rabbits received a daily intraperitoneal injection of 20 micrograms of potassium chromate while the remaining 12 received distilled water. The aortas were examined after a further 30 weeks; their mean weight per unit length was 1.27 g (SE +/- 0.17) in the control group and 0.81 g (SE +/- 0.08) in the chromium treated group (t = 2.36; P < 0.05). The percentage area of intimal surface covered by plaques was 94.8% (SE +/- 1.7) and 62.6% (SE +/- 10.4), respectively (t = 3.53; P < 0.005), and the total cholesterol content per unit length of aorta was 729 mg/100 ml (SE +/- 44.0) and 457.8 mg/100 ml (SE +/- 117.1), respectively (t = 23; P < 0.05). The results show a significant effect of chromium on the regression of cholesterol-induced atherosclerotic plaques in rabbits.

Serum chromium in patients with recent and old myocardial infarction

The serum chromium in 45 subjects with no clinical evidence of ischemic heart disease was found to be 1.71 parts per billion (ppb) (S.E. +/- 0.14). In 34 patients with a previously documented myocardial infarction, it was 1.84 ppb (S.E. +/- 0.18). The difference was not significant nor was there any difference with age or sex. In 37 patients with acute myocardial infarction the serum chromium level rose to a mean of 6.36 ppb (S.E. +/- 0.51; p less than 0.001) during the first five days following the infarct, returning to normal over the next five days. There was no correlation between the serum chromium and blood glucose levels in these patients or in a further 14 patients who were receiving glucose infusions (chest pain without electrocardiographic or enzyme changes) or who were diabetics.

Differential diagnosis of chest pain. Use of isoenzyme LDH1 level as a criterion

Changes in level of isoenzyme LDH1 seem to be a valuable criterion in differentiating acute myocardial infarction from active coronary insufficiency without infarction. LDH1 level increases noticeably within 48 hours after onset of pain from acute myocardial infarction but tends to decrease if the pain is due to active coronary insufficiency.

Magnesium levels in patients with chronic ischemic heart disease

Serum magnesium was measured in 89 control subjects ages 19 to 86 years and in 64 patients (ages 35 to 82 years) who had suffered from acute myocardial infarction at least 6 months previously. No differences were found in the serum magnesium levels due to age or sex nor was there any statistical difference between the mean levels in the two groups. It is concluded that the level of serum magnesium is not associated with the presence or absence of clinically evident ischemic heart disease.

Myocardial infarction with patent coronary arteries

A 62-year-old patient suffered an acute anterior wall infarction as documented by clinical, electrocardiographic and enzymatic evidence. His ECG returned to a near normal pattern on the 5th day. The next day the patient died suddenly. Post mortem examination revealed a transmural anterior infarction with a mural thrombus, and a fresh thrombus in the left renal artery, but the coronary arteries were patient with only slight arteriosclerotic changes. We assume that a coronary thrombus might have been the cause of the infarction, with subsequent lysis. Such early lysis (6 days after the infarction) has not yet been demonstrated in earlier reports.

Fever: genuine or factitious?

Although patients with factitious fever form a small subgroup of all patients investigated for fever of unknown origin, the diagnosis should be kept in mind. If unsuspected, this phenomenon can lead to a multiplicity of laboratory investigations and misuse of hospital beds, as well as to unnecessary risk to the patient.