Nebulised sodium cromoglycate in the treatment of wheezy bronchitis. A multicentre double-blind placebo controlled study

The efficacy of nebulised sodium cromoglycate (SCG) used as a prophylactic treatment of wheezy bronchitis in children aged 1 to 4 years was evaluated in a multicentre double-blind placebo controlled, group comparative study. Fifty-four patients completed the 10-week trial (29 treated with SCG and 25 treated with placebo), preceded by 4-8 weeks baseline. Nebulised SCG did not prove significantly superior to placebo in reducing day wheezing, day coughing, or sleep disturbance due to wheezing or coughing at night. Neither was there significant difference in the use of supportive medicine (beta 2-agonist and theophylline) between the groups. Extra doctor visits, hospital admissions, and parental preference did not show significant difference either.

Inhibition by oral N-acetylcysteine of cigarette smoke-induced "bronchitis" in the rat

Specific pathogen-free rats were exposed to the cigarette smoke (CS) of 25 cigarettes daily for 14 days and concurrently given N-acetylcysteine (Nac) as 1% of their drinking water (average daily dose 973 mg/kg). The thickness of the epithelium was measured at four airway levels and the numbers of mucus-containing secretory cells, stained for neutral or acidic glycoprotein (NGP or AGP respectively), were counted in surface epithelium at eight airway levels. Cigarette smoke increased the thickness of the epithelium at three of the airway levels studied by between 37 and 72%. The number of secretory cells was increased at all airway levels distal to the upper trachea by between 102 and 421%. Secretory cells containing NGP were reduced in number but this was more than offset by a large increase in the number of secretory cells containing AGP at all airway levels. N-acetylcysteine inhibited CS-induced epithelial thickening. Nac also inhibited the CS-induced increase in the number of secretory cells with AGP, but had little effect on the CS-induced reduction in the number of cells with NGP. Thus, prophylactic oral N-acetylcysteine led to an overall inhibition of CS-induced mucous cell hyperplasia and epithelial hypertrophy. The results suggest a novel anti-inflammatory action for a drug with known mucolytic effects.

Anti-inflammatory drugs and experimental bronchitis

Chronic bronchitis (chronic hypersecretion) and chronic bronchiolitis (small airways disease) are two conditions associated with cigarette smoking: both contribute to airflow obstruction in man, the latter associated with progressive deterioration in lung function. Mucous metaplasia and hyperplasia are characteristic histological changes. Experimentally, cigarette smoke given daily for two weeks, induces similar histological changes in the airways of specific pathogen-free rats, providing a suitable animal model for study: an early proliferation of basal cells, accompanied by mucous metaplasia of surface epithelial serous cells is followed by proliferation of newly formed mucous cells. There is also a significant increase in epithelial thickness due to cell hypertrophy without stratification or prior ulceration. Experimentally, secretory cell hyperplasia is inhibited completely or to varying degrees by prophylactic administration (intraperitoneal injection) of either indomethacin, flurbiprofen, dexamethasone, prednisolone, hydrocortisone (each at 2 or 4 mg/kg body weight) or a mucolytic drug, N-acetylcysteine(Nac), given orally as a 1% solution of the drinking water. Nac also inhibits the associated mucus-hypersecretion. It takes between 21 and 84 days, depending on airway level, for the increase in secretory cell number to return to control values (ie recover). Indomethacin and flurbiprofen (4 mg/kg, by ip injection) shorten recovery to between 4 and 9 days in intrapulmonary airways but have no effect on recovery time in the rat trachea. Nac is effective in 6 of 7 airway levels which showed cigarette smoke-induced mucous cell hyperplasia. In conclusion, in the rat, the response to cigarette smoke is one of mucous cell metaplasia and both basal and mucous cell proliferation. Cigarette smoke-induced mucous cell hyperplasia can be inhibited when selected drugs are given concurrently with the cigarette smoke: indomethacin, fluriprofen and Nac are also therapeutic.

Oral immunisation with killed Haemophilus influenzae for protection against acute bronchitis in chronic obstructive lung disease

Fifty patients with chronic obstructive lung disease were randomly allocated to three groups, to assess whether an oral vaccine containing non-typable Haemophilus influenzae protected against acute bronchitis. The double-blind prospective study over a three-month winter period included two placebo groups and one test group. Oral immunisation with H influenzae induced a tenfold reduction in the incidence of infection (p less than 0.001). During the subsequent winter, without further immunisation, protection by the vaccine was no longer statistically significant. There was no clear correlation between clinical protection and either carriage of H influenzae or the level of antibody to H influenzae antigen in saliva.

Managing the older bronchitis patient

In this era of cost containment, it is not appropriate to obtain a complete blood cell count, Gram's stain of sputum, sputum culture, or blood cultures for elderly outpatients with an exacerbation of chronic bronchitis. For monitoring antibiotic therapy of infectious exacerbations, clinicians rely on the patient's observations that dyspnea is less severe, and that sputum volume is reduced and appears more mucoid than purulent. These criteria may be rudimentary, but they have withstood the test of time.

Comparison of early season suppressive anthelmintic prophylactic methods for parasitic gastroenteritis and bronchitis in calves

A comparison was made of the material costs and effectiveness of three methods of early season suppression by anthelmintic medication of Ostertagia species and two of Dictyocaulus viviparus in calves, each method suppressing faecal egg output for different lengths of time from the start of spring grazing. The anthelmintics used were: Morantel bolus administered five days before going to grazing; oxfendazole given three times at three, six and nine weeks after the start of grazing and ivermectin injected three, eight and 13 weeks after going to pasture. The effectiveness of each was estimated by comparison with worm numbers in untreated control calves. Oxfendazole, which was active for the shortest time (about 65 days) from the start of grazing (May 1), produced a 78.1 per cent reduction in Ostertagia species and an 84.4 per cent reduction in D viviparus. The morantel bolus was estimated to be active for 90 days and resulted in a 94.3 per cent reduction of Ostertagia species. The ivermectin treatment, which, because of the prolonged excretion of the chemical and different sensitivity of worm species, was estimated to suppress Ostertagia species for 105 days and D viviparus for 119 days, caused reductions of 98.7 per cent of the former and 97.4 per cent of the latter species. Material costs per calf were estimated at pounds 1.25 for oxfendazole, pounds 2.00 for ivermectin and pounds 10 for the morantel bolus.

Field evaluation of a method for the chemoprophylaxis of parasitic bronchitis in calves

Studies on the epidemiology of Dictyocaulus viviparus infections in Denmark have suggested that the adult lungworms present in calves around the sixth week after turnout play an important role in determining the subsequent pattern of disease. This trial was designed to test whether prophylactic treatment at this time would control disease in calves kept under British conditions. Thirty autumn-born Friesian or Friesian-cross bull calves were allowed to graze the whole of a 5 hectare field for six weeks after turnout. The field was then divided into two and the calves split into matching groups, one group being put into each of the paddocks. One group was treated with levamisole at this time and again two weeks later while the other was kept as an untreated control. Anthelmintic treatment resulted in a marked reduction in larval excretion and considerably delayed the build-up of infection on pasture. This in turn delayed the onset and reduced the severity of clinical signs in the treated group. However, as disease was not eliminated completely this prophylactic programme cannot be recommended to the British farmer in its present form. These findings are discussed in the context of the yet incomplete knowledge of the epidemiology of parasitic bronchitis.

[Multicenter double-blind study of the action of Broncho-Vaxom in chronic bronchitis]

The efficacy of Broncho-Vaxom has been evaluated by a multicentric working group of physicians in 75 patients with chronic bronchitis using a randomized double-blind trial. Initial data of the selected patients showed no significant differences in history, previous medication, individual state and spirometric lung function values between the control group (n = 39) and the cases treated with the test medication (n = 36). After 30-day initial treatment both physician and patient favoured the active substance (p less than 0.01) although there was statistically no evidence of a curative effect measured by objective criteria. Longterm follow-up over a period of six months again revealed a more effective course in the Broncho-Vaxom group according to individual observations (p less than 0.05). In fact there was an impressive trend towards reduction of clinical symptoms with Broncho-Vaxom medication. However, statistical analysis of individual symptoms' scores and lung function tests did not show significant alterations within the two groups. Taking in account the complexity of bronchitic disease, statistical demonstration of a beneficial effect of Broncho-Vaxom with respect to clinical symptoms and lung function tests probably needs a longer observation period, a larger population and a choice of more sensitive methods.

[Vaccination against infectious bronchitis in young chickens--carriers or not of maternal antibodies]

The immunity to infectious bronchitis afforded by spray vaccination of mycoplasma free two days-old broilers with maternal antibodies to infectious bronchitis virus was tested by comparing zootechnical scores, clinical signs, macroscopical and microscopical changes, frequency of infectious bronchitis virus isolation following challenge at one, three and five weeks of age in vaccinated, unvaccinated, challenged and unchallenged birds. This vaccination gave a very good protection to infectious bronchitis for the most part of broiler economical life; growth delays were especially avoided. However, vaccinated and unvaccinated one-week-old birds were not protected enough. No correlation was observed between haemagglutinating antibodies titres and protection. At last this vaccination caused a notable reaction in specific pathogen free control birds of the same age.

Intranasal vaccine trial for canine infectious tracheobronchitis (kennel cough)

Two field trials were conducted during periods of endemic (summer) and epizootic (winter) canine infectious tracheobronchitis activity to evaluate the efficacy of three intranasal vaccines in a closed commercial beagle breeding kennel. A trivalent vaccine containing Bordetella bronchiseptica, canine parainfluenza, and canine adenovirus-2 was administered at 3 weeks of age. The vaccine was 71.2% and 81.8% effective in decreasing the incidence of coughing during the winter and summer trials, respectively. The number of deaths was lower in each of the vaccine groups than in the placebo groups. No adverse reactions were observed with any of the intranasal vaccines.

Intranasal vaccination of dogs with liver avirulent Bordetella bronchiseptica: correlation of serum agglutination titer and the formation of secretory IgA with protection against experimentally induced infectious tracheobronchitis

Dogs inoculated intranasally with a live avirulent Bordetella bronchiseptica vaccine were monitored for the development of resistance to experimentally induced infectious tracheobronchitis (canine cough). Dogs were challenge exposed with a virulent strains of B bronchiseptica at various times after they were vaccinated. Clinical protection was detectable as early as 48 hours. At postvaccination days 4, 5, and 14, 56%, 83%, and 95% protection was observed. Humoral immunoglobulin (Ig) titers ranged from 1:8.6 on day 0 to 1:147 on postvaccination day 21. In the monitoring of B bronchiseptica-specific secretory IgA by indirect immunofluorescence, titers appeared as early as day 4 after vaccination. The IgA titers ranged from 1:16 on day 4 to 1: 1,024 on day 21. The appearance of IgA titers correlated with the development of resistance to clinical infection.