Dengue 2 virus enhancement in asthmatic and non asthmatic individual.

During the 1981 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) Cuban epidemic, bronchial asthma (BA) was frequently found as a personal or family antecedent in dengue hemorrhagic fever patients. Considering that antibody dependent enhancement (ADE) plays an important role in the etiopathogenic mechanism of DHF/DSS, we decide to study the Dengue 2 virus (D2V) capability of replication in peripheral blood leukocytes (PBL) from asthmatic patients and healthy persons. In 90% of asthmatic patients and 53.8% of control group it was obtained PBL with a significant D2V enhancing activity (X2 p < 0.01). Power enhancement was higher in asthmatic group. This is the first in vitro study relating BA and the dengue 2 virus immuno enhancement. The results obtained support the role of BA as a risk factor for DHF/DSS as already described on epidemiological data.

Kerosene-induced asthma.

Clinical evaluation of 286 asthmatic women showed 15.5% of those who improved clinically had contact with kerosene, while 43.9% of those who failed to improve used kerosene as fuel for cooking. In 16 women the onset of asthma occurred soon after they began to use kerosene. Kerosene can cause and aggravate asthma.

Role of chemical mediators in bronchoconstriction induced by kerosene.

Kerosene is a by product of petroleum used in some countries for cleaning, lighting and cooking purposes. Rodriguez de la Vega et al (1981) have presented evidences of the relation between bronchial asthma and the manipulation of kerosene. Since the experiments performed by our group showed that the acute inhalation of the aerosol of kerosene induces bronchoconstriction in rabbits (Casacó et al 1982), we investigated its effect on guinea pig respiratory physiology. In order to elucidate the implication of histamine and arachidonic acid metabolites in kerosene induced bronchoconstriction, we investigated the influence of the administration to guinea pig of a single dose of the histamine H1 antagonist mepyramine (0.1 mg/kg i.v.) 10 minutes before the aerosol and also the effect of the steroidal antinflammatory drug triamcinolone in rabbits (5 mg/kg i.m.) daily during 4 days before the inhalation of kerosene. The histamine concentrations in guinea pig blood before and after the aerosol were also compared. The inhalation of kerosene during 5 min. (20.4 mg/L) by guinea pigs resulted in an increase of airway resistance without increase of blood histamine concentration. On the other hand, the bronchoconstrictive effect of kerosene in guinea pigs and rabbits was not modified by the previous treatment with mepyramine or triamcinolone respectively. The results suggest that the acute bronchoconstriction induced by kerosene is mediated neither by stimulation of histamine H1 receptors nor by the release of chemical mediators.

Relationships between verapamil plasma concentrations and its antihypertensive action.

Twenty-seven hypertensive outpatients were studied to evaluate the efficacy of verapamil after a single oral dose as well as following a short-term treatment and also in combination with oxprenolol. Blood pressure was significantly reduced (p 0.01) after verapamil monotherapy and the combined treatment. PR interval was lengthened from 30 min to 4 h during acute testing, and also after short-term treatment. QT was only prolonged after the verapamil monotherapy. Systolic time intervals (STIs) were not modified, except left ventricular ejection time (LVETc). Direct correlations were found among verapamil plasma concentrations and changes provoked on blood pressure and PR interval. The mean side effects found were disturbance of atrioventricular conduction in two patients without ulterior complications. The results suggest that verapamil monotherapy or in combination with oxprenolol could be useful in the treatment of essential hypertension.

[Bronchial hyperreactivity]. / Hiperreactividad bronquial.

Bronchial hyperreactivity is a condition in which the airways show a much greater bronchoconstriction response to provocative stimuli than what is normal. The stimuli may be specific (different allergens) or non-specific (exercise, infection, cold, air, ozone, kerosene or a variety of inhalant irritants). The normal control of the airways is regulated by: parasympathetic cholinergic nerves, sympathetic adrenergic nerves and non-adrenergic bronchodilator system. The activity in all these pathways regulates bronchomotor tone which is affected by many different reflexes. Such changes play a role in hyperreactivity. Exposure to allergens is another cause of inflammation and specific hyperreactivity which may increase the degree of non-specific bronchial reactivity. Inheritance has been implicated in bronchial hyperreactivity according to animal experiments and human twins studies. Calcium ions are involved in most cellular processes and their role in bronchial hyperreactivity is related to defects in calcium regulation and metabolism. Based on this speculation, calcium antagonist drugs have been used in the treatment of bronchial asthma, though no clinical improvement has been observed by most authors.

Effects of kerosene on airway sensitization to egg albumin in guinea pig.

We undertook a study to determine if pre-exposure to kerosene smoke enhances airway sensitization to egg albumin in the guinea pig. Kerosene vapor inhalation for 15 days, 1 hour daily, in similar conditions to which some housewives who use kerosene as cooking fuel are exposed elicited tracheal damage characterized by signs of dysplasia and inflammatory infiltrate. When these animals were exposed to egg albumin aerosol there was an increase in the antialbumin antibody blood titer and an increased response to egg albumin in the isolated tracheal preparation (Schultz-Dale reaction), We conclude that the airway damage elicited by inhalation of kerosene vapor increase antigen absorption and thereby antibody formation.

Induction of acetylcholinesterase inhibition in the guinea pig trachea by kerosene.

The effect of kerosene on in vivo and in vitro tracheal acetylcholinesterase (CHE) activity of guinea pigs has been investigated. Kerosene aerosol administered to guinea pigs during 20 min at a mean concentration of 20.4 mg/l elicited immediately, 1 h and 24 h later tracheal CHE inhibition by 30, 48.8, and 32.3% of control values (p less than 0.05). Kerosene at 1% concentration inhibited significantly, after 1 h of incubation in vitro, the CHE activity by 44.9% of control values. The tracheal CHE inhibition induced by kerosene could actually increase the acetylcholine concentration acting on smooth muscle of airways, and this partially explains the respiratory symptoms which are frequently observed after kerosene intoxication.

Determinacion de inmunoglobulina E (IgE) en pacientes asmaticos. / Deterination of immunoglobulin E (IgE) in asthmatic patients

Se presentan los valores de IgE encontrados en pacientes de asma bronquial en Cuba utilizando el metodo de Phadebas IgE PRIST Se constato una alta cifra de IgE en suero (mas de 1.000 U/ml) en la mayoria de los pacientes atipicos. Se pudo constatar que la buena evolucion clinica no va seguida de una disminucion de los valores de IgE en el suero y que por lo tanto no tiene valor como parametro evolutivo en el tratamiento. Se presentan los cuadros con los resultados obtenidos y las referencias bibliograficas consultadas

Determinacion de inmunoglobulina E (IgE) en pacientes asmaticos. / Determination of immunoglobulin E (IgE) in asthmatic patients

Se presentan los valores de IgE encontrados en pacientes de asma bronquial en Cuba utilizando el metodo de Phadebas IgE PRIST Se constato una alta cifra de IgE en suero (mas de 1.000 U/ml) en la mayoria de los pacientes atipicos. Se pudo constatar que la buena evolucion clinica no va seguida de una disminucion de los valores de IgE en el suero y que por lo tanto no tiene valor como parametro evolutivo en el tratamiento. Se presentan los cuadros con los resultados obtenidos y las referencias bibliograficas consultadas

Clonidine and prazosin in the treatment of hypertensive outpatients--a preliminary study.

Clinical assessment of a novel antihypertensive drug combination was undertaken in a group of essential hypertensive patients (n = 20). The effects of several doses of clonidine and its association with prazosin on blood pressure (BP), systolic time intervals (STI), and electrocardiogram (ECG) were investigated. Clonidine monotherapy induced a good BP control at 60%. BP was controlled in those patients in which prazosin was combined with clonidine (87.7%). LVETc was reduced by 0.3, 0.6, and 0.9 mg clonidine daily (p less than 0.05). PEPc was increased by only 0.9 mg, and it was diminished after its combination with 20 mg prazosin daily (p less than 0.05). PEP/LVET index was significantly increased by a higher dose of clonidine (p less than 0.05). ECG intervals did not change with the exception of PR, which was prolonged by 0.9 mg clonidine daily (p less than 0.05). Dry mouth, sedation, constipation, and drowsiness were the main side effects observed during the investigation. These results suggest an alternative treatment of essential hypertension, with a novel clinical application of drugs such as clonidine and prazosin, which have pharmacologic action via different alpha-adrenergic mechanisms.

Disodium cromoglycate inhibits bronchoconstriction by kerosine aerosol in rabbits.

To determine whether or not disodium cromoglycate (DSCG) inhibits the bronchoconstriction induced by inhalation of kerosene aerosol in rabbits, we carried out a study in 31 normal rabbits which were divided into four groups. DSCG was administered through the tracheal cannula twenty minutes before exposure to kerosene aerosol. Twenty and forty milligrams of DSCG as total doses inhibited kerosene induced bronchoconstriction in large airways (RL), but 5 mg of drug did not have any effect. DSCG at any tested dose did not inhibit the decreased dynamic lung compliance (CL) which was observed after kerosene aerosol. Our findings suggest that DSCG at high dose inhibit the bronchoconstrictor effect of kerosene in large airways of rabbits.

Investigation of the prevalence and inheritance of bronchial asthma in San Antonio de los Baños, Cuba.

A survey of bronchial asthma prevalence and inheritance patterns was carried out in the municipality of San Antonio de los Banõs, La Habana, Cuba, employing as a sample 3,295 of the area's inhabitants. These persons, selected by stratified, non-restricted sampling techniques, represented 11.02 per cent of the total population. The asthma prevalence found in this sample, which was considered representative of the local population, was 9.74 percent. No significant variations were noted in male and female prevalence rates. The occurrence of bronchial asthma is strongly influenced by inheritance. Our survey supported this view, and also showed that the age of asthma onset is influenced by whether or not the subject's family has a positive history of allergy or not. However, patients with a positive history on one side of their family had an age of onset that was not significantly different from patients with a positive history on both sides (p less than 0.35). Overall, the results tend to confirm that the inheritance of bronchial asthma is autosomal and does not conform to simple dominant or recessive inheritance patterns. Rather, asthma inheritance appears multifactorial, perhaps involving varying degrees of expression, indicating that more is involved than absence or deficiency of a single enzyme.

Investigation of the prevalence and inheritance of bronchial asthma in San Antonio de los Baños, Cuba

A survey of bronchial asthma prevalence and inheritance patterns was carried out in the municipality of San Antonio de los Banâs, La Habana, Cuba, employing as a sample 3,295 of the area's inhabitants. These persons, selected by stratified, non-restricted sampling techniques, represented 11.02 per cent of the total population. The asthma prevalence found in this sample, which was considered representative of the local population, was 9.74 percent. No significant variations were noted in male and female prevalence rates. The occurrence of bronchial asthma is strongly influenced by inheritance. Our survey supported this view, and also showed that the age of asthma onset is influenced by whether or not the subject's family has a positive history of allergy or not. However, patients with a positive history on one side of their family had an age of onset that was not significantly different from patients with a positive history on both sides (p less than 0.35). Overall, the results tend to confirm that the inheritance of bronchial asthma is autosomal and does not conform to simple dominant or recessive inheritance patterns. Rather, asthma inheritance appears multifactorial, perhaps involving varying degrees of expression, indicating that more is involved than absence or deficiency of a single enzyme (Au)