Haptoglobin polymorphism and the immune response after hepatitis B vaccination

One hundred healthy Caucasian medical students (age 22 +/- 1 years) were vaccinated with a recombinant hepatitis B vaccine and their haptoglobin types were determined. A relationship between haptoglobin type and immune response to the vaccine was observed. Subjects with a 2-2 haptoglobin phenotype produced significantly lower hepatitis B antibody titres than those having a 1-1 or 2-1 haptoglobin phenotype. The haptoglobin phenotypes not only influenced the magnitude but also the kinetics of the anti-HBs response. For all haptoglobin types, haptoglobin concentration and immune response to the vaccine behaved independently.

Coagulation system activation and increase of D-dimer levels in peripheral arterial occlusive disease

The aim of the present study was to document coagulation system activation and basal fibrinolysis in peripheral arterial occlusive disease (PAOD) at stage II of Fontaine's classification. In 34 patients, prothrombin fragment (F1 + 2), thrombin-antithrombin III complexes (TAT), and D-dimer concentrations were evaluated before and after a standard treadmill test. Basal levels in PAOD of F1 + 2 (1.25 +/- 0.19 nmol/liter) and of TAT (3.34 +/- 0.35 micrograms/liter) were significantly increased compared to those obtained in age- and sex-matched healthy controls (0.68 +/- 0.06 nmol/liter and 2.30 +/- 0.33 micrograms/liter, respectively), showing baseline activation of the clotting cascade. A secondary activation of the fibrinolytic system was evidenced by the highly significant increase of basal D-dimers (719 +/- 99 ng/dl in PAOD vs. 229 +/- 37 ng/dl in controls). Treadmill exercise failed to increase the study parameters significantly further. Walking distance (583 +/- 40 m) was correlated with the preexercise ankle to brachial systolic blood pressure ratio (r = 0.485, P < 0.005) and inversely with the level of D-dimers (r = -0.425, P < 0.02). Under baseline conditions, the latter parameter was correlated as well with the antigen concentration of urokinase-type plasminogen activator (u-PA; r = 0.503, P < 0.002). These results indicate that stage II PAOD is characterized by an activation of the clotting cascade in baseline conditions evidenced by increased F1 + 2 and TAT. A secondary activation of the fibrinolytic system with increased u-PA antigen levels accounts for the elevated D-dimers. Treadmill exercise was unable to increase these parameters further.

On the relationship between regional circulation and systemic blood pressure

OBJECTIVES

The relationship between regional circulation (blood flow or calculated resistance) and systemic blood pressure (BP) is only poorly documented in the range of intermediate to low BP.

METHODS

In 75 subjects covering the BP range from low, over intermediate, to high BP, venous occlusion plethysmographic recordings were performed at the calf and finger vessels. Correlations were calculated between regional blood flow or vascular resistance and BP defined from office and from 24 h ambulatory BP registrations, at rest and during reactive hyperaemia.

RESULTS

At any BP level, finger blood flow at rest and during reactive hyperemia was higher than calf blood flow, and resistance was lower. The interval of 90-100 mmHg office diastolic BP was characterized by significantly (p < 0.001) higher resting finger blood flow; the increase in resting muscle blood flow was less pronounced. At rest and during reactive hyperaemia there was a stepwise increase in calf regional vascular resistance in parallel with increasing BP. For the finger circulation, increased vascular resistance was only observed for the higher BP values. Correlations between calf and finger vascular resistances and BP were positive and highly significant over the whole BP range, both for office (0.650 < r < 0.776) and for ambulatory BP (0.531 < r < 0.781). These correlations remained significant after adjustment for the age dependency. Increases in calf and finger blood flow induced by arterial occlusion were highest for the lowest BP quintiles.

CONCLUSIONS

Our data further indicated that the capacity to dilate decreased progressively with increasing BP level (from asymptomatic low to high BP) for both calf and finger circulation.

Skin capillary erythrocyte velocity and mean 24 hour ambulatory blood pressure level

This study aimed to examine the relation between capillary dynamics and parameters of ambulatory blood pressure (BP) recordings in a range covering very low to high BP (mean arterial BP: 70-140 mm Hg). A total number of 45 subjects underwent a 24 h ambulatory BP recording at 30 min intervals. The subjects did not receive any medication. Then the subjects were subdivided in 5 categories along their mean 24 h arterial BP values < 80, 80-90, 91-105, 106-115, > 115 mm Hg. Nailfold capillaries were examined at the level of the fourth finger using TV-microscopy. Our results demonstrate that erythrocyte velocity could be maintained relatively constant (mean velocities 700-800 microns/s) within the ambulatory mean arterial blood pressure range of 80-115 mm Hg. For very low and high blood pressures significant decreases (p < 0.01) were noted. Using office mean arterial blood pressure comparable results were obtained.

Left ventricular function and regression of left ventricular hypertrophy in essential hypertension

Although left ventricular hypertrophy (LVH) is an adaptive response to the increased load imposed on the heart in patients with hypertension, it ultimately is itself a major risk factor for cardiovascular disease. The influence of LVH on left ventricular function and on the coronary circulation, and the occurrence of serious ventricular arrhythmias are the major mechanisms of this increased risk. There is no doubt that regression of LVH occurs, but there are clear differences in this respect among antihypertensive drugs: angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists produce the best response. Whether regression of LVH also causes an improvement in left ventricular function is unclear; various studies using the same drugs have yielded contradictory results. Furthermore, it has yet to be determined whether regression of LVH has a positive influence on the long-term prognosis in such patients; the results of the European Multicenter Study OvA will help in shedding more light on this important question.

Myocardial oxygen demands of job activities in post-myocardial infarct patients

In 17 patients who returned to work following rehabilitation after an uncomplicated acute myocardial infarction (AMI), the myocardial oxygen demands (MOD) of various job activities were assessed using discontinuous ambulatory heart rate (HR) and blood pressure measurements. All patients were on beta-blocking agents. HR and rate-pressure product (RPP) reserves were calculated as the differences between maximal values observed during a symptom-limited maximal bicycle exercise test and basal values. Basal values were either pre-test resting values or mean values from night-time registrations between 0100h and 0500h. Night-time values of basal HR and RPP were 7.7 and 18.7% lower respectively as compared to pre-test resting values. The myocardial energy demands of various job activities were calculated as the percentage use of the reserves. This resulted in lower MOD estimations when pre-test values were used as compared to night-time values. These differences were larger for the estimation of MOD of light physical work (mean difference 25%) than for heavy physical work (mean difference 12%). The estimations of MOD using HR reserve or RPP reserve were very similar. In patients who performed the same job activities no correlation was found between MOD and left ventricle ejection fraction. We believe these data provide useful information about the functional capacity of AMI patients. They also emphasise the great importance that has to be attached to the definition of basal values.

Influence of isosorbide dinitrate on superior mesenteric artery impedance in humans

In a randomized, double-blind, placebo-controlled crossover study the acute effect of isosorbide dinitrate (ISDN) on the superior mesenteric artery velocity waveform was studied in 10 healthy subjects (mean age 48.2 years) over a 10-minute period. The superior mesenteric artery pulsatility index (PI), which quantifies the blood velocity waveform, increased from the second minute following sublingual administration of 5 mg ISDN (basal PI 4.88 +/- 0.32) and reached its upper level (8.22 +/- 1.38) from the fourth minute on. In comparison with placebo, the significant rise of PI (second minute) occurred before the significant decrease of systolic blood pressure (ninth minute) and before the significant increase in the heart rate (fourth minute). Diastolic and mean arterial blood pressures remained unchanged. These observations suggest an immediate vasoconstrictive effect of ISDN on the resistance vessels of the vascular bed of the superior mesenteric artery.

Right atrial invasive thymoma with protrusion through the tricuspid valve

A patient with superior caval vein compression due to malignant thymoma with infrequent intracavitary cardiac growth is presented. Diagnostic accuracy of cardiac involvement was higher using transesophageal echocardiography compared to transthoracic echocardiography. The majority of the rare intracavitary cardiac thymomas seem to be confined to the right side of the heart.

Comparison of lisinopril and nitrendipine on the pulsatility index in mild essential arterial hypertension

A double-blind, randomized crossover study was performed in 21 patients with essential arterial hypertension. Nitrendipine 20 mg o.d. and lisinopril 20 mg o.d. were given in a randomized order during a period of each 8 weeks. Nitrendipine and lisinopril decreased systolic and mean arterial blood pressure to a similar level without a significant increase in heart rate. The mean diastolic blood pressure was smaller with the lisinopril treatment than with the nitrendipine treatment. The blood pressure decrease was maintained in the sitting and standing position. Furthermore, only nitrendipine decreased the pulsatility index at the tibial posterior arteries, while lisinopril did not influence it significantly. This finding means that mechanisms other than the blood-pressure lowering effect are involved in the decrease of the pulsatility index.

Acquired Hypolipoproteinemia

We present a six-year follow-up of a boy with a novel type of hypolipoproteinemia, with clinical and biochemical features distinct from classical hypoalphalipoproteinemias. There were abnormally low concentrations of total and high-density lipoprotein (HDL) cholesterol, apolipoprotein (apo) B, apo A-I, and apo A-II, and the phospholipids were decreased. The most striking abnormality was an extra fraction containing mainly phospholipids and apo A-I in the HDL3 subfraction. This fraction is reminiscent of concentric 20- to 50-nm-diameter lamellar phospholipid liposomes. Plasma lecithin:cholesterol acyltransferase activity was strongly decreased. We noted a persisting polyclonal hypergammaglobulinemia, hematological abnormalities (hemolytic anemia and thrombocytopenia), and a progressive splenomegaly. After the five-year follow-up, the patient had recurrent severe infections; moderate hematuria and proteinuria developed gradually. Treatment with corticosteroids and immunoglobulins improved thrombocytopenia and hypolipoproteinemia. These clinical and biochemical findings differ from those in the known primary and secondary hypo-alpha-lipoproteinemia syndromes. Although investigation of the relatives suggests a familial predisposition for hypo-alpha-lipoproteinemia, the subject's condition can be regarded as acquired.

Acquired hypolipoproteinemia

We present a six-year follow-up of a boy with a novel type of hypolipoproteinemia, with clinical and biochemical features distinct from classical hypoalphalipoproteinemias. There were abnormally low concentrations of total and high-density lipoprotein (HDL) cholesterol, apolipoprotein (apo) B, apo A-I, and apo A-II, and the phospholipids were decreased. The most striking abnormality was an extra fraction containing mainly phospholipids and apo A-I in the HDL3 subfraction. This fraction is reminiscent of concentric 20- to 50-nm-diameter lamellar phospholipid liposomes. Plasma lecithin:cholesterol acyltransferase activity was strongly decreased. We noted a persisting polyclonal hypergammaglobulinemia, hematological abnormalities (hemolytic anemia and thrombocytopenia), and a progressive splenomegaly. After the five-year follow-up, the patient had recurrent severe infections; moderate hematuria and proteinuria developed gradually. Treatment with corticosteroids and immunoglobulins improved thrombocytopenia and hypolipoproteinemia. These clinical and biochemical findings differ from those in the known primary and secondary hypo-alpha-lipoproteinemia syndromes. Although investigation of the relatives suggests a familial predisposition for hypo-alpha-lipoproteinemia, the subject's condition can be regarded as acquired.

Blood pressure load determines left ventricular mass in essential hypertension

In a series of 35 newly diagnosed, previously untreated patients (mean age 46 years) with mild to moderate essential hypertension, office blood pressure measurements, 24-hour ambulatory blood pressure monitoring, and determination of left ventricular mass index by echocardiography according to the formula of Devereux were performed. We aimed at correlating left ventricular mass index with systolic and diastolic office blood pressure, mean 24-hour systolic and mean 24-hour diastolic blood pressure, systolic and diastolic load. Left ventricular mass index did not correlate with office systolic and office diastolic blood pressure. On the contrary, all correlations with ambulatory blood pressure parameters and left ventricular mass index turned out to be significant (mean 24-hour systolic blood pressure: r = 0.344, P = 0.026; systolic load: r = 0.408, P = 0.020; mean 24-hour diastolic blood pressure: r = 0.490, P = 0.004; diastolic load: r = 0.504, P = 0.003). These results clearly demonstrate that ambulatory blood pressure determinants but not the office blood pressure parameters are well correlated with left ventricular mass index in mild to moderate essential hypertension. Blood pressure load is as important as mean 24-hour blood pressure in this regard.

Impaired microcirculation in mild-to-moderate essential arterial hypertension

OBJECTIVE

The aim of this study was to correlate capillary morphology and erythrocyte velocity to blood pressure in mild-to-moderate essential arterial hypertension.

DESIGN

Ambulatory blood pressure measurement may provide more precise information about a patient's mean blood pressure than office measurements.

METHODS

Fifteen patients with recently diagnosed, previously untreated mild-to-moderate essential hypertension underwent 24-h ambulatory blood pressure recording and a capillaroscopic examination of finger microcirculation. Erythrocyte velocity was determined by the flying spot technique.

RESULTS

Both mean 24-h ambulatory systolic blood pressure (SBP) and mean 24-h ambulatory diastolic blood pressure (DBP) were significantly inversely correlated with capillary erythrocyte velocity. However, the correlation between erythrocyte velocity and office SBP and office DBP was less significant. Capillary length was related to 24-h ambulatory DBP but not to office DBP. Capillary number was not related to any blood pressure parameter.

CONCLUSIONS

These results indicate that, in patients with mild-to-moderate essential hypertension, erythrocyte velocity is significantly lower than for matched controls. It is also inversely related to mean 24-h ambulatory SBP and 24-h ambulatory DBP.

Evaluation of the metabolic compensation after treadmill test in patients with peripheral occlusive arterial disease

Patterns of release of lactate, hypoxanthine, and arginine into the bloodstream after a standardized treadmill test (twelve minutes, 1.6-2.8 mph, inclination 0,5,10,15%) were recorded in 21 consecutive patients with stage II peripheral arterial occlusive disease. Heart rate, systolic blood pressure, ankle blood pressure, and ankle/brachial systolic blood pressure ratio (A/B ratio), as well as plasma lactate, plasma hypoxanthine and serum arginine were recorded before and at fifteen to thirty-minute intervals for up to two hours after the treadmill test. Immediately after the treadmill test, lactate levels (36.6 +/- 3.7 mg/L) and hypoxanthine levels (2.73 +/- 0.19 mmol/L) were significantly (p less than 0.001) increased but returned to preexercise levels after thirty and sixty minutes, respectively. Arginine levels did not change significantly. Ankle blood pressure (57 +/- 5 mm Hg) and A/B ratio (0.40 +/- 0.04) were significantly (p less than 0.001) decreased after exercise, while heart rate and systolic blood pressure were increased. These parameters returned to normal as well within a half hour after exercise. Absolute walking distance correlated significantly (p less than 0.01) with the postexercise systolic blood pressure (r = -0.62), ankle pressure (r = 0.63) and A/B ratio (r = 0.72). Induced hypoxanthine and lactate production intercorrelated significantly positively (r = 0.57, p = 0.007) but were independent of the absolute walking distance. In contrast with lactate, hypoxanthine production correlated significantly with postexercise ankle pressure (r = 0.49, p = 0.02) and exercise-induced fall in A/B ratio (r = 0.66, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Examination of Raynaud's phenomenon in traumatic vasospastic disorders

Certain types of occupation-related vibrations can cause traumatic vasospastic disorders. Findings from clinical examination are often normal at the office consultation. Measurements of finger blood flow using plethysmography while the local ambient temperature is changed can give important information about the severity of traumatic vasospastic disorder and the concomitant disability. This technique can also be used for follow-up of the finger blood flow after withdrawal from vibrations.

Venous responses to rhythmic exercise in contralateral forearm and calf

Ten normal healthy subjects performed a rhythmic handgrip at 30% MVC (maximal voluntary contraction) with and without arterial occlusion of the same limb. Contralateral forearm and calf venous capacitance were simultaneously measured by venous occlusion plethysmography. During rhythmic handgrip at 30% MVC contralateral venous capacitance decreased by -7.17% in the forearm and by -5.14% in the calf. With arterial occlusion the decreases in venous capacitance were even more pronounced: contralateral forearm -14.4% and calf -13.1%. In a second set of experiments (n = 5) rhythmic handgrip at 30% MVC with arrest of the forearm circulation 5 s prior to the cessation of contraction was applied to examine the influence of chemically sensitive metaboreceptors per se on the evoked limb venoconstriction. During the postexercise arterial occlusion forearm venous volume decreased further to -30.6% whereas calf venous volume increased slightly but remained below the control value. After the cessation of the arterial occlusion both forearm and calf capacitance returned to baseline values. Thus, this study provided evidence that as well as a chemically generated reflex arising from the working muscle, central command was found to be involved in the increase in venomotor tone in the nonexercising limbs during rhythmic handgrip at 30% MVC.

Value of ambulatory blood pressure recordings

In the present paper, the value of ambulatory blood pressure recordings is discussed. Such recordings can be very helpful in the management of high and low blood pressure. The fact that more readings are obtained and that they are made in normal life conditions are the strongest arguments in favour of those recordings. Whether ambulatory recordings predict long term prognosis better than office blood pressure is still open for discussion; the long term European study OvA should help clarifying this important question. Data coming from these techniques are especially useful when conflicting elements are present such as high pressure with no organ damage or blood pressure resistant to all drugs and side effects occurring with even minor doses of antihypertensive drugs. Short term episodes of high or low pressure are best documented with ambulatory blood pressure recordings and this holds particularly true in patients with arterial hypotension. Finally several research aspects can be approached by ambulatory recordings of pressure such as the study of pharmacokinetics of drugs and analysis of blood pressure variability.

Ambulatory blood pressure and prognosis: summary of ongoing studies

Two multicenter European trials studying the correlation between ambulatory blood pressure and long-term prognosis of hypertension are at present underway. The Office versus Ambulatory trial (OvA) has accepted primary hypertensives of all ages, with systolic and diastolic hypertension; in the Systolic Hypertension in the Elderly study (Syst-Eur) only elderly patients with systolic hypertension are being studied. In both trials, blood pressure is being recorded at intervals of 30 min over 24 h, using fully validated non-invasive recorders. Treatment in both studies is based on office blood pressure. As both studies are expected to answer many current questions on the value of ambulatory blood pressure recordings, participation is strongly encouraged.