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Biomedical subjects

G W Sybrecht

Publications and source records attributed to G W Sybrecht.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Therapy of nocturnal asthma: salmeterol versus nocturnal administration of retard theophylline--comparison of effectiveness and tolerance].

The aim of the present study was to compare the efficacy and the tolerability of salmeterol and theophylline in patients with nocturnal asthma. 16 patients were entered into a randomized, double-blind, crossover trial. Using a double-dummy technique, salmeterol (50 micrograms b.i.d. by MDI) or theophylline (Uniphyllin; 600 mg nocte orally) were given for periods of 7 days with a wash-out period of 7 days between treatment periods. With salmeterol the number of nights with an overnight fall in peak expiratory peak flow rate (PEFR) of at least 20% was reduced by about 20% compared to about 10% with theophyllin (p < 0.05 for the difference between salmeterol and theophylline). With respect to nocturnal symptoms 62.6% of the patients had rare or non symptoms without and 84.7% with salmeterol, compared to 46.5% without and 67.3% with theophylline (p < 0.05). With respect to the improvement of early morning symptoms, the increase of nights with none or rare symptoms was 46.2% with salmeterol compared to 25.8% with theophylline. The overall parameter of efficacy defined as a) the number of nights with an overnight fall in PEFR or less than 20% als well as b) none or rare nocturnal symptoms and c) none or rare early morning symptoms increased from 23.4% at baseline to 75.1% during treatment with salmeterol compared to an increase from 24.5% at baseline with 54.8% during treatment with theophylline (p < 0.05). 12 patients preferred salmeterol over theophylline (p < 0.05). 3 patients had gastrointestinal disturbances during theophylline treatment. It can be concluded that both salmeterol and theophylline are effective in the treatment of nocturnal asthma. With respect to the overall efficacy and the tolerability salmeterol is superior to theophylline.

Adult↗
PubMed1996

[The prevalence of sleep-related breathing disorders in patients with implanted cardioverter-defibrillators. The effect on the incidence and circadian distribution of malignant ventricular tachyarrhythmias].

OBJECTIVE: To determine the prevalence of sleep-related breathing disorders (SRBD) on patients who, because of malignant ventricular tachyarrhythmias associated with cardiac disease, have an implanted cardioverter-defibrillator (ICD). It was also investigated whether the frequency and circadian distribution of spontaneous ventricular tachycardia and (or) fibrillation (VTF) can be influenced by SRBD. PATIENTS AND METHODS: 29 consecutive ICD patients (28 men, one woman; mean age 64 +/- 8 years) were investigated by multifunction recordings. 22 patients had coronary heart disease, and seven dilated cardiomyopathy. For each patient the number of VIF episodes per month were recorded, as well as the percentage distribution of the episodes during the day per hour and after grouping into four time periods. RESULTS: SRBDs were recorded in 13 of the 29 patients (45%) (apnoea-hypopnea index [AHI] > 10). The other 16 patients had normal findings (AHI < or = 10). Mean frequency of the registered VTF attacks was similar in both groups (0.41/month with AHI < or = 10 vs 0.44/month with AHI > 10; difference not statistically significant). Averaged percentage distribution pattern showed a maximum frequency in both groups between 6 o'clock and 12 o'clock a.m. There was no significant increase of VTF during the night (10 o'clock p.m.-6 o'clock a.m.) in the group with SRBD (19% with AHI > 10 vs 18.2% with ATF < or = 10; difference not significant). CONCLUSION: There was a high prevalence of SRBD in the patients with ICD and underlying cardiac disease. No influence of SRBD on frequency and circadian distribution of VTF was demonstrated in patients with ICD during long-term observation.

Aged↗
PubMed1996

[Proportional assisted ventilation--clinical use of a new ventilation mode].

BACKGROUND: Proportional assist ventilation (PAV), a new mode for assist ventilation, allows the patient not only to trigger the ventilator but enables him to keep his breathing pattern. The basis of PAV is a positive feed back between patient and ventilator. PATIENTS AND METHOD: PAV was applied in 6 patients, who were under long-term ventilation and who were stable. The ventilator was adjusted to compensate for the endotracheal tube, different parts between 90 and 40% of resistance and elastance were assisted. Airway pressure, flow and tidal volume were measured. PAV was compared with pressure support ventilation (PSV). RESULT: No difference in blood gases were found in PAV as compared to PSV. Airway pressure were lower in PAV than in PSV (10.4 +/- 3.3 cm H2O vs. 18.8 +/- 5.9 cm H2O in PSV). Breathing frequency was higher (22.4 +/- 8.1 vs. 15.8 +/- 5.9 in PSV). CONCLUSION: The higher breathing frequencies in PAV were associated with the underlying diseases and resulted in a better synchronisation with the respiratory center output.

Humans↗
PubMed1996

DNA amplification on chromosome 3q26.1-q26.3 in squamous cell carcinoma of the lung detected by reverse chromosome painting.

Multiple genetic lesions have been reported in small cell lung carcinoma (SCLC), while considerably less information is available on squamous cell carcinoma (SCC). We used reverse chromosome painting to screen a total of nine SCCs for DNA amplifications. In three of the nine SCCs, hybridisation signals were found at chromosome region 3q26.1-q26.3, which does not contain any known oncogene. In one of the three SCCs, there were additional hybridisation signals at 1q, 5p and 6p21.1. The high frequency of a consistent amplification (3q26.1-q26.3) in SCC strongly indicates a novel gene at 3q26.1-q26.3 that is important in the pathology of SCC.

Aged↗
PubMed1995

Tolerance, safety, and kinetics of the new antineoplastic compound dexniguldipine-HCl after oral administration: a phase I dose-escalation trial.

Dexniguldipine-HCl is a new dihydropyridine compound that exerts selective antiproliferative activity in a variety of tumor models and, in addition, has a high potency in overcoming multidrug resistance. The purpose of this trial was to determine the toxicity and pharmacokinetics of dexniguldipine and to establish a recommended dose for phase II trials. A total of 37 patients with cancer were treated with oral dexniguldipine in increasing doses for up to 7 days. The main parameters evaluated were subjective tolerance and laboratory and cardiovascular parameters (blood pressure and ECG). Blood samples were drawn for analysis of the drug's pharmacokinetics. Dizziness and nausea were the major adverse events observed in seven patients, but episodes were generally mild and not clearly dose-related. Vomiting occurred in one patient. Hypotensive effects and orthostatic dysregulation were observed in some patients but were not considered to be dose-limiting. Therefore, no dose-limiting toxicity was found and the maximally tolerable dose could not be determined. Pharmacokinetic data showed wide interindividual variation and a dose-dependent increase in steady-state serum concentrations at doses of up to 1,000 mg daily, with no clear further increase being observed at higher doses. Consistently high concentrations were achieved with the 2,500-mg dose. Despite the lack of dose-limiting toxicity, higher doses of dexniguldipine do not appear to be useful for clinical evaluation because of the pharmacokinetic properties of the compound: therefore, 2,500 mg/day is recommended as the daily dose for phase II trials.

Administration, Oral↗
PubMed1995

Effects of the mixed phosphodiesterase III/IV inhibitor, zardaverine, on airway function in patients with chronic airflow obstruction.

Zardaverine is a selective inhibitor of phosphodiesterase (PDE) III and IV isozymes. It has been shown to exert potent bronchodilator effects in animals. In order to study the efficacy and safety in man, a phase II clinical trial in 10 patients with partially reversible chronic airflow obstruction was carried out. The trial was designed as a double-blind, randomized, five-period change-over study. Zardaverine (at single doses of 1.5 mg, 3.0 mg, or 6.0 mg), salbutamol (0.3 mg) and placebo were administered by metered dose inhaler on separate days. As evaluated by spirometry over a time period of 4 h, salbutamol induced a significant bronchodilatation. In contrast, zardaverine did not improve airway function in these patients. Unwanted effects of the study medication were not observed.

Aged↗
PubMed1995

[18FDG in the primary staging of lung tumors. Results with a gamma camera and a 511 keV collimator].

The diagnosis of primary lung tumors requires a precise staging according to the TNM classification. In contrast to established imaging methods 18FDG describes the functional metabolic processes in the tumor tissue due to increased glycolysis. This paper describes the use of 18FDG in the primary staging of lung tumors and metastases. 44 patients were studied with a gamma camera and a 511 keV collimator. In comparison to pulmonary tumors and metastases detected by other imaging methods (107) the accumulation of 18FDG has a sensitivity of 85%, in lesions verified by histology (50) of 89%, in primary tumors (35) of 100% and in metastases (63) of 76%. As an alternative to FDG PET studies, primary staging of lung tumors is possible with a gamma camera, suitable for ECT and fitted with a 511 keV collimator.

Adult↗
PubMed1995

[Tumor markers as prognostic factors in non-small-cell bronchial carcinoma].

PURPOSE: Considerations of different therapeutic approaches require a realistic estimation of the prognosis. The usefulness of tumor markers as prognostic indicators was evaluated by means of a multivariate analysis. PATIENTS AND METHODS: The data of 300 patients who had been irradiated for their primary tumor were analysed retrospectively. The serum concentrations of CEA, SCCA, NSE, and LDH were available before treatment and 3 months thereafter in a sufficient number of cases. The prognostic factors for survival and progression-free survival resulting from univariate tests were further evaluated by a Cox-proportional-hazards model. RESULTS: The serum levels of the particular tumor markers were pathologically elevated in 25 to 36.5% of the cases. Their values correlated with the stage of the disease and separately the N-stage too. A normalization of increased marker levels after irradiation occurred in 37.5 to 67% of the cases. Survival of patients with increased pretherapeutic values of CEA, SCCA, and LDH was significantly worse compared to those with normal values. In the case of a post-therapeutic return to normal levels, prognosis was significantly better than for those where the elevation persisted. However, after inclusion of all other parameters in multivariate analysis the tumor markers were meaningless. Karnofsky-performance status, total dose of radiotherapy, stage of the disease, and weight-loss evolved as independent prognostic factors for survival. For progression-free survival only stage of the disease was important. All subgroup analyses (restriction on patients with favorable prognosis) showed the same results. CONCLUSIONS: A prognostic importance of NSE could not be demonstrated. CEA, SCCA, and LDH were univariate predictors for survival and progression-free survival. But they proved to be dependent on the stage of the disease and were not confirmed as independent variables in the Cox-model. Their importance during the follow-up is diminished by the frequent lack of therapeutic approaches in the case of disease progression. Certainly a more favorable prognosis in case of a post-therapeutic normalization of previously elevated values was found.

Biomarkers, Tumor↗
PubMed1995

[Death or uncertain cause].

The unclear case of death usually occurs suddenly and unexpectedly, but can mostly be attributed to a underlying disease which was unknown during the life-time of the patient. A reduction of mortality might be achieved by improved preventive measures and early treatment. During the last years, the sleeping apnea syndrome as an example turned out to be a considerable risk factor for cardiovascular diseases and accidents. Nevertheless, very many patients exist with an unrecognized sleeping apnea syndrome and are in urgent need of therapy. At first, unclear cases of death in the area of internal medicine can mostly be solved by an autopsy. Autopsy results are demonstrating that only one of three pulmonary embolism has been recognized clinically. The correct diagnosis for an unexpected death in the area of internal medicine could be almost ever found by a more careful differential diagnosis; only a few cases of death remain unclear after optimal diagnostics. At first, one has to think of a pulmonary embolism, cardiac arrhythmias or myocardial ischemia when a sudden death has occurred. Additionally, a pneumothorax, an alimentary bolus or an asthma attack may cause death unexpectedly. Metabolic dysfunctions, poisoning or a ruptured aortic aneurysm are often not recognized as the cause of death if it is not especially looked for.

Asthma↗
PubMed1994

T helper cell alveolitis after bacillus Calmette-Guerin immunotherapy for superficial bladder tumor.

We report a case of T helper cell alveolitis after intravesical bacillus Calmette-Guerin (BCG) immunotherapy for a superficial bladder tumor. Despite the clinical appearance of miliary pulmonary tuberculosis no mycobacterial agent was found. Therefore, we concluded that the patient had a hypersensitivity reaction similar to sarcoidosis. The condition improved after immunosuppressive therapy with glucocorticosteroids. Differentiation of bronchoalveolar cells could be useful in distinguishing hypersensitivity to infection with BCG.

Aged↗
PubMed1993

Adenosine receptor-blocking xanthines as inhibitors of phosphodiesterase isozymes.

The pharmacological actions of methylxanthines such as theophylline and caffeine may be due to blockade of adenosine receptors and/or inhibition of phosphodiesterase (PDE) activities. In the last years, potent xanthines have been developed that display some selectivity for A1 and A2 adenosine receptors. Little is known about the PDE inhibitory potency of these xanthines. The aim of the present study was to determine the potencies of A1 and A2 receptor selective xanthines as inhibitors of several PDE isozymes, the PDE I-V subtypes. The IC50 values of 8-phenyl- and 8-cycloalkyl-1,3-dialkylxanthines for inhibition of PDE isozymes from different sources are up to 10,000-fold higher than their antagonistic potencies at adenosine receptors. However, the A1 receptor selective antagonists 1,3-diethyl-8-phenylxanthine and 1,3-dipropyl-8-cyclopentylxanthine are comparatively potent inhibitors of PDE IV activity with IC50 values in the 10 microM range and are, therefore, nearly as potent as the PDE IV selective inhibitor, rolipram. The A2 receptor selective 1,3-dipropyl-7-methylxanthine is about 10-300-fold more potent as an adenosine receptor antagonist than as a PDE inhibitor. The results indicate that some of these novel xanthines can be used as selective adenosine receptor antagonists without interference due to inhibitory effects on PDEs.

1-Methyl-3-isobutylxanthine↗