Efficacy and tolerability of myrtol standardized in acute bronchitis. A multi-centre, randomised, double-blind, placebo-controlled parallel group clinical trial vs. cefuroxime and ambroxol

Myrtol standardized (Gelomyrtol forte) is a phytotherapeutic extract (distillate) consisting mainly of three monoterpenes: (+)alpha-pinene, d-limonene and 1,8-cineole. OBJECTIVE: This study describes and compares the efficacy, safety and tolerability of a 2-week treatment with myrtol stand. (4 x 300 mg, day 1-14), cefuroxime (CAS 55268-75-2) (2 x 250 mg daily for day 1-6), ambroxol (CAS 18683-91-5) (3 x 30 mg for day 1-3, 2 x 30 mg for days 4-14) and matched placebo in acute bronchitis. PATIENTS: 676 male and female outpatients, aged > or = 18 years, with acute bronchitis of recent onset (within last 5 days), with an FEV1 > 75% of the normal EGKS-value and without evidence or suspicion of chronic pulmonary disease or any further confounding illness were included in the study. INTERVENTION: Patients were randomly assigned to a 2-week treatment course with either myrtol stand. (N = 170), cefuroxime (N = 171), ambroxol (N = 163) or placebo (N = 172) in a double-blind, placebo-matched, parallel-group fashion. Evaluations were at baseline (visit 1), after 1 and 2 weeks of treatment (visits 2 and 3) and at 2 weeks after conclusion of the treatments (visit 4). CRITERIA: Responder- and non-responder rates (primary), signs (abnormal auscultation), symptoms (daily diary data on nightly cough, coughing fits during the day, sputum consistence and general well-being; visit data on bronchial hyperreactivity and absence/presence of associated symptoms), FEV1, overall efficacy, absence of relapse, safety and tolerability (adverse events, laboratory screens, vital signs and physical examination). Criteria were evaluated for the intention-to-treat data-set (ITT) and the 'efficacy evaluable' sample (EAP), i.e. excluding patients with missing values (incl. discontinued non-responders and drop-outs for other reasons) at the time of assessment. RESULTS: The signs and symptoms of acute bronchitis regressed readily in all treatment groups, but regression was slower and less complete in the patients treated with placebo. In patients treated with placebo, the acute bronchitis was considered to have deteriorated to such an extent that discontinuation was indicated ('non-responder') in 36 patients (ITT: 20.9%, 95% CI: 15.1 to 27.8% and EAP: 21.3%, CI: 15.4 to 28.3%) after 1 week (visit 2) and in 19 further patients (ITT: 11.0%, CI: 6.8 to 16.7%; EAP: 14.8%, CI: 9.2 to 22.2%) after 1 further week (visit 3). In contrast, in the group of patients treated with myrtol stand. the non-responder rates at visits 2 and 3 were only 5.3% (ITT, CI: 2.4 to 9.8%; EAP: 5.4%, CI: 2.5 to 10.0%) and 1.2% (ITT, CI: 0.1 to 4.2%; EAP: 1.3%, CI: 0.2 to 4.7%); the responder rates at visit 2 were statistically significantly higher (p < 0.001) for myrtol stand. (ITT: 92.9%, CI: 88.0 to 96.3) compared to placebo (ITT: 77.3%, CI: 70.3 to 83.4), and similar to those for cefuroxime (ITT: 92.4%, CI: 87.4 to 95.9) and ambroxol (ITT: 89.6%, CI: 83.8 to 93.8%). The superiority of the active treatments vs. placebo with little difference among the treatments was confirmed for all further criteria of evaluation. There was no evidence of bronchoconstriction or relapse in any treatment group for the patients continuing treatment (i.e. for those who were not discontinued because of non-response). The treatments were safe and comparably well tolerated. CONCLUSION: Compared to placebo, treatment with myrtol stand. was well tolerated but evidently superior in terms of efficacy, resulting in a more rapid and more complete recovery; although well comparable with the other active treatments, myrtol stand. tended to be superior to cefuroxime and ambroxol for several ancillary criteria. Myrtol stand. is a well-evidenced alternative to antibiotics for acute bronchitis without specified infective agent, without the risk to promote the development of bacterial resistance.     

Vasodilator reactivity to calcitonin gene-related peptide is increased in mesenteric arteries of rats during early pregnancy

The objective of the present study was to determine the effect of early pregnancy on the sensitivity to, and endogenous production of calcitonin gene-related peptide (CGRP). Contractile responses of arteries of 10-day pregnant and nonpregnant rats were studied in myographs. During contractions induced by 40 mmol/l K(+), exogenous CGRP elicited an approximately 30% stronger relaxation in mesenteric arteries in pregnancy, an effect not seen in renal and uterine arteries. Capsaicin treatment during K(+)-induced contractions caused a persistent potentiation of the contractile response in mesenteric arteries, indicating that K(+) stimulates the endogenous release of CGRP. This potentiation was similar in the pregnant and nonpregnant state (+81 +/- 23% and +82 +/- 23%, respectively), suggesting no effect of pregnancy on the endogenous CGRP release. The latter was paralleled by comparable CGRP content in the arteries of both groups, indicating similar tissue CGRP availability. The results of this study support the concept that early pregnancy is associated with a rise in the vascular sensitivity to CGRP in selected areas of the vascular bed without concomitant increase in the vascular CGRP production and release.     

The v-erbA oncogene blocks expression of alpha2/beta1 integrin a normal inhibitor of erythroid progenitor proliferation

T2EC are chicken erythrocytic progenitors that balance between self-renewal and differentiation as a function of response to specific growth factors. Their transformation by the v-erbA oncogene locks them into the self-renewal program. We show here that the expression of the VLA-2 integrin alpha2 subunit mRNA is downregulated by v-erbA and that VLA-2 engagement and clustering, brought about by treatment with an alpha2-specific antibody or by culture on the VLA-2 ligand collagen I, inhibits T2EC proliferation. From competition studies using antibodies, VLA-2 was shown to be involved in the collagen-induced response. While engagement of VLA-2 inhibited proliferation, it was not sufficient to induce differentiation. The transformation of T2EC by v-erbA decreased their interaction with collagen I and the VLA-2 brake on cell proliferation, which may account for the increased proliferation potential of transformed erythrocytic progenitors and for their shedding into the blood of infected chickens. Our data suggest that the interaction between erythroid progenitors and collagen, mediated by VLA-2, play a major role in the control of erythropoiesis in vitro and that this pathway is a target of the v-erbA oncogene.     

Acute transient encephalopathy after paclitaxel infusion: report of three cases.

Paclitaxel (Taxol) is a diterpene plant product and antineoplastic agent that promotes the assembly of microtubules as well as stabilizing their formation by preventing depolymerization. Myelosuppression was found to be dose-limiting, but peripheral neurotoxicity is also a well known side-effect. Central nervous system toxicity is rare, probably because paclitaxel does not cross the blood-brain barrier. We observed three patients who presented with acute encephalopathy within 6 h after infusion of paclitaxel at normal doses. All patients had received prior whole brain irradiation (WBI) and one patient had prior brain metastasectomy. Computer tomography and magnetic resonance imaging showed no evidence of cerebral metastases. An effect from other organ toxicities was excluded in all patients. All recovered spontaneously within 4-6 h. From this we can conclude that paclitaxel can cause severe acute transient encephalopathy, which may occur more frequently after prior WBI and/or surgery due to alteration of small vessel function.     

Benzo[a]pyrene at an environmentally relevant dose is slowly absorbed by, and extensively metabolized in, tracheal epithelium

While tobacco smoke has been conclusively identified as a lung carcinogen, there is much debate over which smoke constituent(s) are primarily responsible for its carcinogenicity. Previous studies in our laboratory suggested that highly lipophilic carcinogens are slowly absorbed in the thicker epithelium of the conducting airways, potentially allowing for substantial local metabolism. The bioactivation of polycyclic aromatic hydrocarbons in airway epithelium may, hence, be important in tobacco smoke-induced carcinogenesis. In the present study, the hypothesis of slow absorption and substantial local metabolic activation of highly lipophilic carcinogen in airway epithelium was tested in dogs. A single dose of tritiated benzo[a]pyrene (BaP) dissolved in a saline/phospholipid suspension was instilled in the trachea, just anterior to the carina. At intervals of a few minutes up to 30 min over a 3-h period, blood samples were drawn from the azygous vein, which drains the area around the point of instillation, and from the systemic circulation. Tissue samples were taken at the end of the experiment. The concentration of BaP with depth into the tracheal mucosa was determined with autoradiography. BaP was slowly absorbed into the trachea with a half-time of approximately 73 min, which is consistent with diffusion-limited passage through the epithelium and lead to local doses in the tracheal epithelium that were more than a 1000-fold those of other tissues. The long retention of BaP in the epithelium provided the local metabolizing enzymes with high substrate levels over a long period, resulting in extensive metabolism. At 3 h after the exposure, 23% of the BaP-equivalent activity remained in the tracheal mucosa. Of this fraction, 13% was parent compound, 28% was organic extractable, 31% was water-soluble, and 28-7% of the instilled dose was bound to tracheal tissues. These results explain the tendency of highly lipophilic carcinogens, such as BaP, to induce tumors at the site of entry and, furthermore, indicate that the highly lipophilic components of tobacco smoke and polluted air may be the most important contributors to lung tumors of the conducting airways.      

Need for follow up in coeliac disease

The use of follow up studies was evaluated in 128 patients with coeliac disease during their first visit to a department for adults. The original diagnosis had been made in childhood in all patients. Fifty eight (45%) of the subjects were following a gluten free diet, 23 (18%) were following a gluten free diet but with occasional gluten consumption, and 47 (37%) had adopted an unrestricted, gluten containing diet for a mean of 11.2 years. There was no correlation in individual subjects between the presence of symptoms, biochemical and immunological abnormalities, severity of histological findings, and the amount of dietary gluten, despite the greater frequency of symptoms in the group following an unrestricted diet than in the other two groups. Short stature and epilepsy with cerebral calcifications only occurred in patients following an unrestricted diet. As only diagnosis based on two or three biopsy samples and regular follow up correlated positively with dietary compliance, it is suggested that a histologically confirmed diagnosis of coeliac disease and regular lifelong follow up are essential in the management of these patients.     

Elderly Patients with Suppressed Serum TSH but Normal Free Thyroid Hormone Levels Usually Have Mild Thyroid Overactivity and are at Increased Risk of Developing Overt Hyperthyroidism

The clinical and biochemical characteristics of 15 elderly patientswith low levels of thyrotrophin (TSH) (<0.1 mU/L) but normalfree tri-iodothyronine, (T3) and free thyroxine (T4) (groupS) were compared with 10 euthyroid subjects (group E) and 10hyperthyroid patients (group T). Free T3 and free T4 were significantlyhigher (p<0.05) in group S(6.3±0.5 and 18.6±1.0pmol/l, respectively) than in group E(4.6±0.3, 12.6+0.6).In common with elderly hyperthyroid patients (group T)patientsin group S had few signs or symptoms of thyrotoxocosis, butthe Wayne score (clinical index of hyperthyroidism) was higherin group S than in euthyroid subjects (p<0.05). Thyroid microsomal,thyrogolobulin or thyrotrophin receptor antibodies were commonin group T (n=9)but not in groups S(n=2) or E(n=1). This suggestsa low prevalence of Graves' disease in group S compared to groupT. Combined thyrotrophin releasing hormone (TRH; 200 µgi.v.) and gonadotrophin releasing hormone GnRH; 100 µgi.v.) tests were performed; no cases of low TSH due to hypopituitarismwere identified in group S. During a mean of 7.9 (4–12)months of observation TSH reverted to the normal range (>0.2mU/L)in 7 of 15 patients in group S; thyroid hormone concentrationsrose above the normal range in four, however, only two patientsrequired treatment for hyperthyroidism. It is unlikely thatthe suppressed TSH of patients in group S was due to mild thyroidhormone excess; although this is often a transitory phenomenon,these patients are at increased risk of developing overt hyperthyroidism.     

Alpha 1-adrenoreceptor blockade reduces the angiotensin II-induced vascular smooth muscle cell DNA synthesis in the rat thoracic aorta and carotid artery.

We explored effects of alpha 1-adrenoreceptor blockade with prazosin on the increased vascular smooth muscle cell (SMC) DNA synthesis induced by angiotensin II (Ang II) in rats. Ang II was infused with or without prazosin or its solvent. Observations were compared with those in rats receiving saline or solvent. In group A, Ang II was infused for 2 weeks by subcutaneously implanted osmotic minipumps at a rate of 35 ng/100 g per minute. Group B received Ang II together with the alpha 1-adrenoreceptor antagonist prazosin (0.35 micrograms/100 g per minute). Group C received Ang II and 50% dimethyl sulfoxide (DMSO), the solvent of prazosin; group D received 50% DMSO; and group E received 0.9% NaCl (Ang II vehicle). All animals were infused with 5-bromo-2'-deoxyuridine for 2 weeks via separate minipumps to measure DNA synthesis. Ang II significantly increased the fraction of DNA synthesizing SMCs in the media of the thoracic aorta from 0.4 +/- 0.1% (mean +/- SD) in group E (n = 6) to 10.8 +/- 7.0% in group A (n = 8). Addition of prazosin to Ang II reduced the labeling fraction of SMCs to 3.0 +/- 2.2% (group B, n = 9). The remaining SMC DNA synthesis in the prazosin-treated group was probably due to the effects of the solvent of prazosin, i.e., 50% DMSO, since infusion of 50% DMSO alone increased the labeling fraction to 4.1 +/- 2.0% (group D, n = 6).(ABSTRACT TRUNCATED AT 250 WORDS)