A comparison of new nonsedating and classical antihistamines in the treatment of primary acquired cold urticaria (ACU).

The efficacy of the new nonsedating antihistamines loratadine and cetirizine was compared in a randomized, single-blind, crossover, controlled study with that of the classical antihistamines cyproheptadine and ketotifen in seven patients with primary acquired cold urticaria (ACU). The patients received each of the four drugs for 14 consecutive days with a 7-day interval between drugs. We evaluated clinical symptomatology, adverse effects, minimum time of cold contact stimulation required to induce an immediate coalescent wheal (CSTT), and inhibition of histamine-induced wheal response. Both loratadine and cetirizine showed suppression of symptoms with infrequent adverse effects. Important side-effects were observed in patients receiving cyproheptadine. Improvement in CSTT was statistically significant for all drugs compared with baseline values, without differences among them. The histamine-induced skin test was significantly inhibited by all antihistamines. Wheal reductions were 34.6% for loratadine and 50.9% for cetirizine. This study suggests that both loratadine and cetirizine may be effective in the treatment of primary ACU.     

Levels of cardiovascular risk factors in type 2 diabetes mellitus are dependent on the stage of proteinuria.

Levels of cardiovascular risk factors were determined in 75 patients with Type 2 diabetes mellitus. The patients were divided into three groups according to their urinary protein excretion (UPE): (a) normal proteinuria (less than or equal to 70 mg d-1); (b) microproteinuria (70-500 mg d-1); and (c) macroproteinuria (greater than 500 mg d-1). A significant stepwise increase in mean systolic blood pressure, LDL-cholesterol and fibrinogen levels was observed from the first to the third investigated group of patients. Mean apoprotein B levels were significantly increased in the group with macroproteinuria compared to the other two groups. Significant linear correlations were found between UPE and LDL-cholesterol, total cholesterol, apoprotein B, creatinine, systolic blood pressure and diabetes duration. In summary, it is concluded that the levels of some cardiovascular risk factors increase with the stage of proteinuria in Type 2 diabetes mellitus.     

Ugandan HIV-1 V3 loop sequences closely related to the U.S./European consensus.

The third variable (V3) loop of the human immunodeficiency virus type 1 (HIV-1) envelope protein is an important determinant for virus neutralization and cell tropism. V3 loop sequences from uncultured lymphocytes obtained in 1990 from 22 Ugandan HIV-1-infected patients could, with the exception of two patients' sequences, be divided into two groups (A and B) on the basis the V3 loop size and sequence. The V3 loop consensus sequences from both groups showed a high degree of homology to a U.S./European consensus, a characteristic also reflected by the results of peptide serology. In the case of group B the difference in sequence was only five amino acids. In contrast, the V3-flanking regions for both groups showed greater homology to an earlier (1986/1987) Ugandan consensus. The discovery of these two new Ugandan V3 loop genotypes, which are closely related to the U.S./European consensus, has implications for the understanding of the evolution of HIV-1 and for the future design of a vaccine for use in Africa.     

Abnormalities of thirst regulation in patients with chronic renal failure on hemodialysis.

To determine whether thirst mechanisms are altered in nondiabetic patients with chronic renal failure on hemodialysis, 4 patients with an average weight gain between dialysis sessions of more than 5% of dry body weight (group I), 5 patients with less than 3% weight gain (group II), and a group of 6 healthy subjects (group III) were submitted to infusion of hypertonic saline. After infusion the subjects had free access to water. Thirst was evaluated by visual analogue rating scales. Despite similar increments of effective plasma osmolality during saline infusion, patients of group I were thirstier than groups II and III (p less than 0.005 and p less than 0.01, respectively). Changes in thirst ratings were similar in groups II and III. Osmotic thresholds for thirst onset were similar in groups II and III (288.9 +/- 8.5 and 289.8 +/- 3.4 mosm/kg, respectively), but lower in group I (277.6 +/- 7.6 mosm/kg). Nevertheless, great variations were observed in the latter group. Thus, 2 patients showed thresholds for thirst within the normal range, whereas the others had low osmolar thresholds for thirst and baseline plasma osmolalities and high basal thirst scores. During the drinking period, the patients of group I drank more (14.2 +/- 2.8 ml/kg) than those of groups II (5.3 +/- 1.6 ml/kg; p less than 0.02) and III (10.2 +/- 1.6 ml/kg; n.s.) The plasma levels of angiotensin II in uremic patients were higher than in healthy subjects, although there were no differences between groups I and II and no correlation between basal angiotensin II levels and the interdialytic weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)     

Natural history of experimental pulmonary atelectasis in dogs with closed chest

In order to establish an animal model of pulmonary vasoconstriction we followed the time course of intrapulmonary shunt (Qs/Qt) in a canine model of lobar atelectasis with closed chest. Ten mongrel dogs were studied. Bronchial occlusion of the right lower lobe (RLL) was performed by inflating the balloon of a Foley catheter placed through a rigid bronchoscopy. Analysis of variance was used for statistical analysis. (15 minutes) After occlusion Qs/Qt reached its maximum increasing from 8.2 +/- 3.6 to 29.7 +/- 11.7% (p less than 0.05) and PaO2 decreased from 357 +/- 49 to 100 +/- 43 mm Hg (p less than 0.05). Afterwards, there was a progressive decline of Qs/QT accompanied by an also progressive increase in PaO2. At the end of the experiment (3 hrs post atelectasis) Qs/Qt was 11.2 +/- 4.9 and PaO2 251 +/- 124 mm Hg (p less than 0.05). Pulmonary vascular resistance increased post atelectasis from 439 +/- 168 to 598 +/- 256 d.s.cm-5 (p less than 0.05). Complete atelectasis of the RLL was confirmed postmortem. As the changes in Qs/Qt and PaO2 did not parallel the change in cardiac output we conclude that the mechanism of decrease in Qs/Qt was hypoxic vasoconstriction.     

Doppler echocardiography in the diagnosis of pulmonary hypertension

Review of the current state of knowledge about Doppler diagnosis of pulmonary hypertension is presented. The authors compare the findings of numerous studies with their own data and analyse the causes of discrepancies and controversies that have remained to date. Doppler estimation of mean pulmonary artery pressure (PAP) using acceleration time (ACT) measurement in the right ventricular outflow tract or main pulmonary artery has been shown to correlate closely with simultaneously measured values of PAP both at rest and during exercise (r = -0.92 and -0.94, respectively). ACT values show sufficient sensitivity for the detection of pulmonary hypertension (89%), at maximum (100%) specificity. However, Doppler values not obtained simultaneously do not necessarily correlate with PAP in view of rapid physiological variations of PAP. For everyday diagnostic practice in cardiology, prediction based upon mere qualitative estimation of the type of velocity curve seems sufficient. Doppler diagnosis of pulmonary hypertension, little demanding on both technical skills and equipment, is gaining a priority status among the non-invasive methods available.