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Biomedical subjects

W Biernacki

Publications and source records attributed to W Biernacki.

At least 19 recordsLinked to original sources

Exhaled carbon monoxide levels elevated in diabetes and correlated with glucose concentration in blood: a new test for monitoring the disease?

PURPOSE: In diabetes, the interaction of glycated proteins with their cell-surface binding sites leads to oxidative stress and induction of the stress protein heme oxygenase (HO)-1. Considering that carbon monoxide (CO) is a product of HO activity, we studied the level of exhaled CO as a marker of oxidative stress in diabetes. METHODS: Eight patients with insulin-dependent diabetes mellitus (type 1) (4 men, 4 women; [mean +/- SEM] age, 50 +/- 8 years) were studied, of whom 2 had peripheral neuropathy and 1 had renal failure. Sixteen patients with non-insulin-dependent diabetes mellitus (type 2) (5 men, 11 women; age 63 +/- 8 years) were studied, of whom 2 had peripheral neuropathy. Glycosylated hemoglobin (HbA(1)c) levels were higher (7.4 +/- 0.3%) in patients with type 1 (mean duration of the disease, 20 +/- 5 years) than in type 2 (4.9 +/- 0.4%; p < 0.05; mean duration of the disease, 11 +/- 2 years). All of the patients were lifelong nonsmokers. RESULTS: Levels of exhaled CO were higher in patients with diabetes (type 1, 4.0 +/- 0.7 ppm; type 2, 5.0 +/- 0.4 ppm) when compared to 37 nonsmoking healthy subjects (20 men, 17 women; age, 33 +/- 3 years) (2.9 +/- 0.2 ppm; p < 0.05). There was a positive correlation between exhaled CO levels and the incidence of glycemia in all subjects (r = 0.52, p < 0.05) and the duration of diabetes (r = 0.48, p < 0.05), but there was not a strong correlation with concentrations of HbA(1)c (r = 0.06, p = 0.8). In addition, an oral glucose tolerance test was performed in five healthy nonsmoking volunteers (three men; age, 33 +/- 4 years). The maximal glucose increase (from 3.9 +/- 0.2 to 5.5 +/- 0.1 mmol/L at 15 min; p < 0.05) was associated with a significant increase in exhaled CO concentration (from 3.0 +/- 0.5 to 6.3 +/- 1.0 ppm; p < 0. 05). Both parameters returned to the baseline at 40 min after glucose administration. CONCLUSIONS: Elevated levels of exhaled CO in diabetes may reflect HO-1 induction and oxidative stress. The measurement of CO may be a new tool for disease monitoring.

Adult↗

Acupuncture in treatment of stable asthma.

Previous studies of acupuncture in asthma have reported conflicting results, some claiming benefit for some patients. We conducted a randomized, double-blind (patient and evaluator) study in 23 non-smoking asthmatics (10 M; 13 F) aged 43 +/- 15 years with forced expiratory volume in 1 s (FEV1) 59 +/- 16% pred. After initial assessment (respiratory function tests and Asthma Quality Life Questionnaire) patients were randomized to receive either 'real' or 'sham' acupuncture. The measurements were repeated within 1 h and after 2 weeks. Patients were recording peak expiratory flow rate (PEFR) throughout the period of the study. After 2 weeks patients who received 'real' treatment on the first visit received 'sham' treatment and vice versa. The measurements were again repeated within 1 h and after 2 weeks. There was no improvement in any aspects of respiratory function measured after either form of acupuncture. Despite this there was a significant improvement in AQLQ and parallel reduction in the usage of bronchodilators. We concluded that in some patients acupuncture could be useful in improving quality of life and reducing the need for using bronchodilators either by having a placebo effect or that the exact site of needle puncture on the chest is unimportant.

Acupuncture Therapy↗

Measurement of CT lung density in patients with chronic asthma.

Evidence for the presence of emphysema in patients with asthma is controversial. We have previously shown that decreased lung density, measured by computed tomographic (CT) scanning, preoperatively, correlates with morphometric measurements of microscopic emphysema in subsequently resected lungs. The aim of this study was to compare CT lung density, in 17 patients with chronic asthma (forced expiratory volume in one second (FEV1) 1.98 (SD 0.77) L), 17 patients with chronic bronchitis and emphysema (FEV1 0.97 (0.56) L) and seven normal subjects (FEV1 3.5 (034) L). All subjects underwent CT scanning of the lungs and respiratory function testing within 2 days of each other. In five of the asthmatic patients a CT scan was performed on two occasions before and after treatment with nebulized bronchodilator. In a different group of five asthmatics these measurements were performed at the end of and 6 weeks after an exacerbation. The mean value of the lowest fifth percentile of the CT lung density in the patients with chronic obstructive pulmonary disease (COPD) was -942 (SD 36) Hounsfield units (HU), in the 17 asthmatic patients was -912 (34) HU, and in normal subjects was -880 (13). Despite a significant increase in peak expiratory flow rate from 266 (SD 102) to 406 (83) L x s(-1) (p<0.02) following nebulized beta2-agonist in five patients with chronic asthma, there was no significant change in CT lung density (p>0.05) Our study indicates that at least some patients with chronic, stable asthma develop a reduction in computed tomography lung density, similar to that in patients with emphysema.

Acute Disease↗

[Evaluation of emphysema progression as measured by computed tomography in patients with chronic obstructive pulmonary disease].

It has been difficult to assess the progression of pulmonary emphysema since accurate quantification of the extent of this condition has only previously been possible on post mortem or resected lungs. Previously we have shown that measurements of CT lung density correlated with the degree of emphysema, measured morphometrically in resected lungs. We have therefore employed this technique to assess the progression of emphysema in 17 patients (12M, 5F) with wide range of chronic airflow limitation (FEV1 15-68% predicted). There was little change in the degree of airflow limitation, hyperinflation or arterial blood gas values over 30 +/- 4 months of follow up (p > 0.05). However during this period there was a significant decrease in the lowest 5th percentile of CT density, which fell from -920 +/- 32 to -940 +/- 36 Hounsfield units (p < 0.005) associated with significant fall in the diffusing capacity for carbon monoxide. We believe that these data show the ability of CT scanning to assess the progression of emphysema in patients with chronic obstructive pulmonary disease.

Aged↗

Assessment of the right ventricle by magnetic resonance imaging in chronic obstructive lung disease.

Right ventricular wall and chamber volume were measured by magnetic resonance imaging in 16 patients with stable chronic obstructive lung disease who subsequently underwent measurement of pulmonary haemodynamics by right heart catheterisation. The patients had a forced expiratory volume in one second of 0.7 (SD 0.3) litres, a forced vital capacity of 2.4 (1.0) l, an arterial oxygen tension (PaO2) of 6.5 (1.3) kPa, an arterial carbon dioxide tension (PaCO2) of 6.5 (1.0) kPa, and a mean pulmonary arterial pressure 30 (10) mm Hg. The mean right ventricular free wall volume was 57.1 (22.6) cm3, compared with a mean value of 115.0 (44.3) cm3 for the left ventricle and interventricular septal volume. The right ventricular chamber volume at end systole was 44.8 (23.4) cm3, whereas the left ventricular end systolic chamber volume was 51.1 (35.1) cm3. The right ventricular free wall volume correlated with the right ventricular chamber volume (r = 0.71), systolic (r = 0.74) and mean (r = 0.72) pulmonary arterial pressure, pulmonary vascular resistance (r = 0.67), and PaCO2 (r = 0.56). There was no significant correlation between the right ventricular free wall volume and PaO2 or the right ventricular ejection fraction, measured by radionuclide ventriculography. Assessment of the right ventricle by magnetic resonance imaging may help to better define patients with cor pulmonable and assess the long term effects of treatment in such patients.

Adult↗

The effect of six months of daily treatment with the beta-2 agonist oral pirbuterol on pulmonary hemodynamics in patients with chronic hypoxic cor pulmonale receiving long-term oxygen therapy.

We studied the acute and long-term effect of the oral beta-2 agonist pirbuterol on pulmonary hemodynamics and right and left ventricular ejection fractions in 11 patients with stable hypoxic chronic bronchitis and emphysema who were maintained on long-term oxygen therapy. We have used a double-blind study with random allocation of patients to receive either pirbuterol or an identical-appearing placebo. Six patients received 15 mg pirbuterol thrice daily, and five patients received a similar placebo thrice daily, over a 6-month period. The first 15-mg dose of pirbuterol by mouth at the beginning of the study raised the heart rate from 84 +/- 13 to 100 +/- 16 beats/min (mean +/- SD) (p less than 0.01), and cardiac output from 5.2 +/- 0.9 to 6.4 +/- 0.8 L/min (p less than 0.01) and right ventricular ejection fraction (RVEF) from 0.28 +/- 0.10 to 0.33 +/- 0.12 (p less than 0.01) within 120 min after receiving the drug, but without significant change in the mean pulmonary arterial pressure. None of these variables changed significantly after an acute dose of placebo in another four patients. Repeated measurements after 6 months of chronic oral therapy with either pirbuterol or placebo showed that 16 h after the last 15-mg oral dose of pirbuterol or placebo, the heart rate, mean pulmonary arterial pressure, cardiac output, total pulmonary vascular resistance, and RVEF were all not significantly different from the values 6 months previously, before receiving either pirbuterol or the placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗

Pulmonary hemodynamics, gas exchange, and the severity of emphysema as assessed by quantitative CT scan in chronic bronchitis and emphysema.

We have used the CT transthoracic scan to measure regional lung density in vivo, as our previous studies have shown that this correlates with the increase in size of distal air spaces, which is a defining characteristic of emphysema. We have studied 32 patients with chronic airflow limitation (FEV1, 15 to 68% predicted) caused by chronic bronchitis and emphysema (synonym, COPD), with a wide range of arterial PO2 (38 to 90 mm Hg) and PCO2 (32 to 63 mm Hg) while breathing air at rest. We could find no significant relationships between the extent of emphysema (as assessed in vivo by the EMI number defining the lowest fifth percentile of the CT density histogram of the lung fields) and either arterial blood gas tensions, mean pulmonary arterial pressure, cardiac output, or calculated total pulmonary vascular resistance while at rest (n = 32) or during supine leg exercise (n = 29). We conclude that the extent of emphysema does not correlate with the clinical or pathologic features of the "pink and puffing" (i.e., mild hypoxemia, no CO2 retention, no pulmonary hypertension, etc.) or "blue and bloated" (i.e., hypoxemia, CO2 retention, pulmonary hypertension) pattern of patients with COPD nor to the spectrum of hemodynamic and gas exchange abnormalities that commonly occur in patients between these two extreme examples. Thus, "pink puffers" should not be equated with "the emphysematous" pattern of this disease. Although these clinicophysiologic patterns remain valid as descriptions, they do not relate to the extent of underlying emphysema in COPD.

Aged↗

Doxazosin, a new alpha-1-antagonist drug, controls hypertension without causing airways obstruction in asthma and COPD.

The treatment of systemic hypertension in patients with coexisting chronic airflow limitation is difficult. Even a 'cardioselective' beta-blocker potentially can increase airflow limitation. However it is very unlikely that alpha 1 blockers can bronchoconstrict. We have therefore evaluated the efficacy and safety of doxazosin, a new orally active selective alpha 1 blocker, in patients with systemic hypertension with concomitant airflow limitation. We studied 21 patients (11M, 10F) whose diastolic blood pressure was 95-114 mmHg and FEV1 22-73% of predicted. In the 19 patients who completed the study the dose of doxazosin to achieve satisfactory control of the systemic hypertension lay between 1 and 16 mg (mean 6 +/- 3.6 mg). This doxazosin dosage reduced the diastolic blood pressure on average from 103 to 91 mmHg (P = 0.0001). However this produced no significant changes in peak expiratory flow rate (PEFR) over the days of the study (P greater than 0.05). The mean variations in PEFR both 'day to day' (P less than 0.001) and 'within day' (P less than 0.002) were reduced during doxazosin therapy, and FEV1 rose on average from 1.6 to 1.7 (P less than 0.05). We conclude that doxazosin is an effective oral antihypertensive drug, which does not exacerbate pre-existing airflow limitation.

Adrenergic alpha-Antagonists↗

Does right ventricular function predict survival in patients with chronic obstructive lung disease?

Non-invasive measurements of the right ventricular ejection fraction by radionuclide ventriculography were made in 115 patients with chronic obstructive lung disease. Survival was assessed over a mean period of 918 days. The right ventricular ejection fraction was reasonably normal in most patients (mean 0.42, range 0.10-0.66) but was lower in those with peripheral oedema, indicating cor pulmonale (mean 0.31 (SD 0.07); p less than 0.0001). Right ventricular ejection fraction was related to survival, but the relationship was weak (p = 0.03) by comparison with the association between the arterial oxygen and carbon dioxide tensions and survival (both p less than 0.0001). It is concluded that, although right ventricular function is predictive of survival in patients with chronic obstructive lung disease, it is probably a reflection of severity of disease and does not directly affect the prognosis.

Adult↗

Pulmonary hypertension and right ventricular function in patients with COPD.

In 100 patients with chronic obstructive pulmonary disease (COPD), we found no significant correlation between simultaneous measurements of right ventricular ejection fraction, using radionuclide ventriculography, and pulmonary arterial pressure. There was, however, a weak but significant correlation between right ventricular ejection fraction and the pulmonary vascular resistance (r = 0.40, p less than 0.005). In 52 of these patients, 37 with pulmonary hypertension, right ventricular end-systolic volume index was 53 +/- 21 ml.m-2 and end-diastolic volume index was 86 +/- 27 ml.m-2, compared with a calculated mean of 33 ml.m-2 and 79 ml.m-2, respectively, for normal subjects. In 24 of these patients where the measurements were made at rest and on exercise, the mean right ventricular end-systolic volume increased from 66 +/- 20 ml.m-2 to 87 +/- 32 ml.m-2, with an increase in right ventricular systolic pressure from 28 +/- 9 mm Hg to 55 +/- 15 mm Hg. Analysis of the slope of the right ventricular end-systolic pressure volume relationship at rest and on exercise suggested relatively normal right ventricular contractility in the majority of patients. Thus, in these patients with stable COPD, despite the presence of pulmonary hypertension, right ventricular contractility remained relatively normal.

Blood Pressure↗