Characterization of glutathione S-transferase expression in lymphocytes from chronic lymphocytic leukemia patients

Chronic lymphocytic leukemia (CLL) is a disease state which frequently responds to alkylating agent chemotherapy but ultimately becomes refractory through acquired resistance mechanisms. In the present study, we have examined the expression of glutathione S-transferases (GST) in both CLL and normal control lymphocytes, as these enzymes have been implicated in mechanisms of natural and acquired resistance. Lymphocyte GST was purified from samples by high-pressure liquid affinity chromatography, and subunits were identified by two-dimensional gel electrophoresis and immunoblotting by using polyclonal antibodies specific for individual subunits. Analysis of CLL lymphocyte GST activity using the general substrate 1-chloro-2,4-dinitrobenzene showed a statistically significant 2-fold increase in cells from chlorambucil-resistant patients over those from untreated patients and normal individuals. Furthermore, chlorambucil therapy was seen to cause a 1.3- to 1.5-fold elevation of enzyme activity in three previously drug-naive patients. Analysis of GST isozyme subunits indicated that 95% of the CLL patients examined were positive for the pi isozyme, and this appeared quantitatively to be the major isozyme present. The alpha and mu isozymes were also expressed in 63 and 53% of the patients, respectively. Examination of control lymphocytes, as well as separated B- and T-cell subpopulations, yielded similar results. The present study indicates that a high degree of interindividual variation occurs and that the pattern of CLL lymphocyte GST expression differs from that of other tumor tissues. While there were no obvious correlations between the disease state or stage and isozymes expressed, the quantitative increase in GST activity in chlorambucil-resistant CLL patients may be of relevance to the overall resistant phenotype.     

An isolated perfused rat lung preparation for the study of aerosolized drug deposition and absorption

The isolated, perfused rat lung preparation was modified to allow characterized solid aerosol delivery. Deposition and airway-to-perfusate transfer of disodium fluorescein from 3-4 micron dae solid aerosols were studied under different ventilatory regimes. The lungs inhaled from an aerosol stream of constant concentration via a tracheal cannula. Air displacement from a sealed artificial thorax housing the lungs provided the driving force for inhalation. The lungs were suspended in a physiologically normal position and both left and right sides of the heart were cannulated for constant rate perfusate flow. Fractional deposition was inversely proportional to respiratory frequency implying that sedimentation was the primary deposition mechanism. Increasing tidal volumes similarly enhanced the ratio of amount deposited/amount administered. Fluorescein transfer to the perfusate occurred from the lung regions containing intact vasculature, was apparent first-order, and independent of perfusate flow. The average rate constant for transfer was 0.057 +/- 0.02 min-1 (t1/2 = 12.2 +/- 4.2 min-1). The ratio of transferable amount/amount deposited appeared to indicate the depth of aerosol penetration. This increased at high respiratory frequency and tidal volume, while decreasing with increasing aerosol particle size. Potential applications of the model are discussed in the light of these results.     

Zur Meßsicherheit der oszillometrischen Blutdruckmeßgeräte Dinamap 1846 und HP M-1008B

Using the PTB simulator, which emits real signals from patients, we examined the precision of the oscillometric blood pressure measurement with the Dinamap 1846 (Critikon) and the HP M-1008B (Hewlett Packard). For this purpose we simultaneously registered invasive arterial pulsewave, cuff pressure and cuff pressure oscillations of 20 patients from our intensive care unit and stored them in the database of the simulator. The invasive reference blood pressure values were determined following the recommendations given by the Association for the Advancement of Medical Instrumentation. The invasive system showed a cut-off frequency of 35?Hz; the damping constant was 0.21. With 49 record signals from patients we carried out 15 simulated measurements each. From a total of 49 bio-signals from patients the Dinamap 1846 was able to process 41 signals and the HP M-1008B 47 signals. The mean error of the oscillometric blood pressure measurement of the systolic, diastolic and mean arterial pressure amounted to ?2.50?mmHg, 3.35?mmHg (P<0.05) and 1.51?mmHg with the Dinamap 1846 and to ?8.5?mmHg (P<0.001), ?5.15?mmHg (P<0.001) and ?5.58?mmHg (P<0.001) for the HP M-1008B. The 95% confidence limit for the systolic, diastolic and the mean arterial pressure amounts to 56?mmHg, 30?mmHg and 35?mmHg for the Dinamap 1846 and 50?mmHg, 38?mmHg and 35?mmHg for the HP M-1008B. The differences between that two instruments could be caused by the different algorithms for the calculation of blood pressure values and different artefact detection and elimination techniques. The results of the performance tests we achieved with the PTB simulator correspond to the results of other clinical examinations. The American Association for the Advanecement of Medical Instrumentation recommends a maximum mean error of 5±8?mmHg. None of the examined instruments lay within these limits. Due to the systematic and stochastic errors, we think that the Dinamap 1846 (Critikon) and the HP M-1008B (Hewlett Packard) do not achieve performance levels that are adequate for measuring critically ill patients.     

LHRH analogues do not protect the germinal epithelium during chemotherapy

Summary The protective effect of Decapeptyl, a d-Trp⁶-LHRH analogue, on the germinal epithelium of rats during chemotherapy was examined in an experimental animal study. Four groups were formed consisting of 15 (groups A and B) and 20 (groups C and D) Sprague-Dawley rats, respectively. The animals were treated as follows: group A (control group) was given 0.9% NaCl i.m.; group B (LHRH group) d-Trp⁶-LHRH analogue (Decapeptyl); group C (LHRH + chemotherapy group) Decapeptyl +_cyclophosphamide; group D (chemotherapy group) cyclophosphamide. The gonads were removed before therapy was initiated and on days 13, 52, and 182 after treatment and examined histologically. In addition, follicle-stimulating hormone (FSH) levels in the serum, a sensitive indicator of tubular damage, were determined. The most damaging effects of chemotherapy on histology and hormone levels were observed in the animals in group C, which were additionally treated with LHRH analogues. Therefore, it is not possible to protect the germinal epithelium of the rat with LHRH analogues during chemotherapy.     

Carcinoma of the small intestine

The radiological features of five cases of primary adenocarcinoma of the jejunum are described and the differential diagnosis is discussed. Barium examination is the best method for detecting adenocarcinoma in the small intestine and angiography is useful for pre-operative assessment.     

Is osteoporosis in postmenopausal female patients related to previous pregnancies and/or miscarriages?

OBJECTIVE: To investigate if osteopenia and osteoporosis in postmenopausal female patients are related to previous pregnancies and/or miscarriages. PATIENTS AND METHODS: We studied 81 postmenopausal female patients, 40 with osteopenia or osteoporosis and 41 without osteopenia or osteoporosis, carefully matched for age (control group). In the two groups, the presence or not of osteopenia, osteoporosis, or both, were analyzed and compared with the number of childbirths and/or miscarriages. RESULTS: Overall, no statistical difference was found among the 40 patients with one, two, three or more than three childbirths and osteopenia or osteoporosis compared with the control group (p=0.5363, p=0.5782, p=0.0763, p=0.1931, respectively). Similarly, no differences were found between the osteopenia/osteoporosis group and the control group in relation to previous one, two, three or more than three miscarriages. When both childbirths and miscarriages were added together (three, four, five, six, more than six), again no statistical difference was found between the osteopenia/osteoporosis group and the control group. CONCLUSIONS: In postmenopausal women, the obstetric history of previous childbirths and/or miscarriages, independent of the number, did not seem to be a risk factor for osteopenia or osteoporosis.