Open-label, randomized comparison of itraconazole versus caspofungin for prophylaxis in patients with hematologic malignancies.

Invasive fungal infection remains the most common cause of infectious death in acute leukemia. In this open-label, randomized study, we compared the efficacy and safety of caspofungin with that of intravenous itraconazole for antifungal prophylaxis in patients undergoing induction chemotherapy for acute myelogenous leukemia or myelodysplastic syndrome. Of 200 patients, 192 were evaluable for efficacy (86 for itraconazole, 106 for caspofungin). Duration of prophylaxis (median, 21 days [range, 1 to 38 days]), demographics, and prognostic factors were similar in both groups. Ninety-nine patients completed antifungal prophylaxis without developing fungal infection (44 [51%] with itraconazole, 55 [52%] with caspofungin). Twelve patients developed documented invasive fungal infections, five in the itraconazole group (four with candidemia and one with Aspergillus pneumonia), and seven in the caspofungin group (two with candidemia, two with disseminated trichosporon species, two with Aspergillus pneumonia, and one with disseminated Fusarium spp). Two patients in the itraconazole group and four in the caspofungin group died of fungal infection (P = 0.57). Grade 3 to 4 adverse event rates were comparable between groups; the most common event in both was reversible hyperbilirubinemia. No evidence of cardiovascular toxicity from intravenous itraconazole was noted among patients older than 60. In conclusion, intravenous itraconazole and caspofungin provided similar protection against invasive fungal infection during induction chemotherapy, and both drugs were well tolerated.

Beneficial pharmacokinetic interaction between cyclosporine and itraconazole in renal transplant recipients.

BACKGROUND: Itraconazole is often given for fungal prophylaxis to renal transplant recipients, who require concomitant cyclosporine in the immediate posttransplant period. We determined the extent of the pharmacokinetic interaction between cyclosporine and itraconazole oral solution in renal transplant recipients and the effect on daily drug costs. METHOD: This was a single-center, open-label, nonrandomized study. Posttransplantation, renal transplant recipients received itraconazole solution 200 mg twice daily and cyclosporine, dosed to achieve target concentrations. Once at steady state, blood samples were collected over 12 hours for pharmacokinetic evaluation of cyclosporine, itraconazole, and hydroxy-itraconazole. Itraconazole was discontinued after approximately a 3-month prophylaxis regimen. Cyclosporine doses were titrated to achieve target concentrations and cyclosporine concentrations were once again determined when steady state was achieved. A noncompartmental analysis was used to analyze cyclosporine pharmacokinetic parameters. The pharmacoeconomic impact was measured based on the percent change in dose of cyclosporine when administered with and without itraconazole. Drug costs were calculated using the average wholesale price. The cost per patient, as well as the average cost, was calculated for the cyclosporine/itraconazole combination, as well as the cyclosporine regimen alone. RESULTS: Eight renal transplant recipients completed the study. All were included for itraconazole analyses and seven for cyclosporine analyses. Mean peak and trough itraconazole levels were 1.64 +/- 0.82 and 1.23 +/- 0.90 microg/mL respectively. Mean peak and trough hydroxy-itraconazole levels were 2.37 +/- 1.55 and 2.20 +/- 1.48 microg/mL, respectively. While on itraconazole, a 48% reduction in the mean total daily dose of cyclosporine was necessary to maintain target concentrations (171 +/- 63.6 versus 329 +/- 103.5 mg, P =.003). This reduction in cyclosporine dose resulted in a discounted itraconazole daily drug cost of approximately 29.5%. CONCLUSION: Administering itraconazole with cyclosporine allows for a decrease in the cyclosporine dose, thus lowering daily drug costs and providing adequate antifungal coverage with itraconazole and hydroxy-itraconazole trough concentrations above the MIC(90) of Candida and Aspergillus spp.

Pharmacokinetics of nevirapine and lamivudine in patients with HIV-1 infection.

The purpose of this parallel treatment group, double-blind, multicenter study was to characterize the pharmacokinetics of nevirapine and lamivudine when coadministered to patients with the HIV-1 infection. This pharmacokinetic interaction study was nested within a larger Phase III clinical trial conducted to characterize the safety and efficacy of coadministered nevirapine and lamivudine. One hundred HIV-1 infected patients with CD4+ lymphocyte counts < 200 cells/mm3and who were on a background of nucleoside (zidovudine [ZDV], didanosine [ddI], zalcitabine [ddC], stavudine [d4T]) therapy were randomly assigned to be treated with either nucleoside + lamivudine + nevirapine or nucleoside + lamivudine + placebo. Each patient underwent blood sampling at defined times for the purpose of determining the concentration of nevirapine in plasma and lamivudine in serum under steady-state conditions. Each patient was also monitored closely for concomitant administration of other drugs, including ZDV, ddI, ddC, d4T and cotrimoxazole. The pharmacokinetics of nevirapine and lamivudine were characterized using nonlinear mixed-effects modeling. There were no reported serious adverse events during the 40-day pharmacokinetic study. The results of the modeling analysis revealed that nevirapine had no effect on the pharmacokinetics of lamivudine. Estimates of the apparent clearance for nevirapine (CL/F = 3.3 L/hour; 95% confidence interval [CI] 2.9 to 3.7 L/hour) and lamivudine (CL/F 27.6 L/hour; 95% CI 22 to 33.2 L/hour) were consistent with the values reported in earlier trials. However, the results also showed that concomitant administration of lamivudine with cotrimoxazole resulted in a 31% reduction in the apparent clearance of lamivudine, resulting in a 43% increase in the average steady-state lamivudine serum concentrations. These results indicate that chronic concurrent administration of cotrimoxazole with lamivudine may significantly affect the steady-state pharmacokinetics of lamivudine.

Inhibitory receptors alter natural killer cell interactions with target cells yet allow simultaneous killing of susceptible targets.

Inhibitory receptors expressed on natural killer (NK) cells abrogate positive signals upon binding corresponding major histocompatibility complex (MHC) class I molecules on various target cells. By directly micromanipulating the effector-target cell encounter using an optical tweezers system which allowed temporal and spatial control, we demonstrate that Ly49-MHC class I interactions prevent characteristic cellular responses in NK cells upon binding to target cells. Furthermore, using this system, we directly demonstrate that an NK cell already bound to a resistant target cell may simultaneously bind and kill a susceptible target cell. Thus, although Ly49-mediated inhibitory signals can prevent many types of effector responses, they do not globally inhibit cellular function, but rather the inhibitory signal is spatially restricted towards resistant targets.

High-dose nevirapine in previously untreated human immunodeficiency virus type 1-infected persons does not result in sustained suppression of viral replication.

High-dose nevirapine treatment has been reported to confer sustained antiretroviral effects, despite a rapid development of resistance. The use of this strategy was evaluated in 20 previously untreated human immunodeficiency virus type 1 (HIV-1) p24 antigenemic persons with CD4 cell counts between 100 and 500/mm3. Treatment consisted of 400 mg of nevirapine, after a 2-week lead-in dose of 200 mg. Rash was the most frequently reported adverse event, occurring in 25%. While sustained declines in p24 antigen levels were observed in the majority, serum HIV-1 RNA load and CD4 cell counts returned to baseline values within 12 weeks in virtually all subjects. The resistance-conferring tyrosine-to-cysteine substitution at reverse transcriptase position 181 was detected after 4 weeks in most subjects. These observations suggest that plasma drug levels attained with high-dose nevirapine were not sufficient to inhibit nevirapine-resistant virus, although they were approximately 2-fold higher than reported IC50 values of resistant virus.

Micromanipulation of statoliths in gravity-sensing Chara rhizoids by optical tweezers.

Infrared laser traps (optical tweezers) were used to micromanipulate statoliths in gravity-sensing rhizoids of the green alga Chara vulgaris Vail. We were able to hold and move statoliths with high accuracy and to observe directly the effects of statolith position on cell growth in horizontally positioned rhizoids. The first step in gravitropism, namely the physical action of gravity on statoliths, can be simulated by optical tweezers. The direct laser microirradiation of the rhizoid apex did not cause any visible damage to the cells. Through lateral positioning of statoliths a differential growth of the opposite flank of the cell wall could be induced, corresponding to bending growth in gravitropism. The acropetal displacement of the statolith complex into the extreme apex of the rhizoid caused a temporary decrease in cell growth rate. The rhizoids regained normal growth after remigration of the statoliths to their initial position 10-30 micrometers basal to the rhizoid apex. During basipetal displacement of statoliths, cell growth continued and the statoliths remigrated towards the rhizoid tip after release from the optical trap. The resistance to statolith displacement increased towards the nucleus. The basipetal displacement of the whole complex of statoliths for a long distance (>100 micrometers) caused an increase in cell diameter and a subsequent regaining of normal growth after the statoliths reappeared in the rhizoid apex. We conclude that the statolith displacement interferes with the mechanism of tip growth, i.e. with the transport of Golgi vesicles, either directly by mechanically blocking their flow and/or, indirectly, by disturbing the actomyosin system. In the presence of the actin inhibitor cytochalasin B the optical forces required for acropetal and basipetal displacement of statoliths were significantly reduced to a similar level. The lateral displacement of statoliths was not changed by cytochalasin B. The results indicate: (i) the viscous resistance to optical displacement of statoliths depend mainly on actin, (ii) the lateral displacement of statoliths is not impeded by actin filaments, (iii) the axially directed actin-mediated forces against optical displacement of statoliths (for a distance of 10 micrometers) are stronger in the basipetal than in the acropetal direction, (iv) the forces acting on single statoliths by axially oriented actin filaments are estimated to be in the range of 11-110 pN for acropetal and of 18-180 pN for basipetal statolith displacements.

Recombinant human interferon-gamma in patients with chronic granulomatous disease--European follow up study.

This was an uncontrolled, open-label follow up study of a previous 12-month, randomized, double-blind, placebo-controlled trial performed to assess the long-term efficacy and safety of Recombinant Human Interferon Gamma (rIFN-gamma) in patients with chronic granulomatous disease (CGD). In two centres, 28 patients (24 male, 4 female) with a mean age of 16 years (range 3-37) entered the open-label phase. The patients were treated for a mean of 880 days (range 97-1375 days). Visits were scheduled every 180 days and patients completed one to six visits. rIFN-gamma was administered subcutaneously three times weekly at a dose of 0.05 mg per m2. During the open-label phase of the study 12 patients experienced a serious infection requiring hospitalization within 880 days. The median infection-free time was 993 days. No obvious increase of infections over time was seen. Phagocyte superoxide anion production and phagocyte staphylococcal killing were not influenced by therapy. Seven patients were withdrawn from the study, one because of an adverse reaction, three on their own wish and the other three because they changed to another trial. No patient died during the study. Conclusion. Treatment of patients with CGD with intracellular active antibiotics and additional interferon gamma as infection prophylaxis is safe and justified.

Laser micromanipulators for biotechnology and genome research.

The use of lasers for complete micromanipulation of metaphase chromosomes, cells and subcellular structures is reviewed. DNA probes from single microdissected chromosome segments can be prepared using Alu or Adaptor PCR. In plant biotechnology, laser microsurgery can be used to prepare non-enzymatically protoplasts from Medicago sativa. Microgravity can be simulated in the alga Chara by lifting intracellular gravity transmitting elements with the optical tweezers.

UV-B-laser-induced DNA damage in lymphocytes observed by single-cell gel electrophoresis.

Human lymphocytes from a cell culture were irradiated with 12 mJ pulses (524 J m-2) of an XeCl excimer laser (308 nm). DNA strand breaks were analysed with the "comet assay", a single-cell method. The DNA damage of individual cells could be investigated depending on the energy and the irradiated volume. DNA damage could be detected already after a single laser pulse of 12 mJ. Since the irradiation time is short compared with the DNA repair time, DNA damage is solely dependent on the total number of photons. A quantitative evaluation of the number of damaged cells vs. number of photons can be best explained by a detection threshold model. The calculated threshold is 1.25 x 10(8) photons cell-1. From this and the principal sensitivity of the comet assay, one can estimate that the upper limit for DNA damaging efficiency is 400,000 photons.

The laser microbeam trap as an optical tool for living cells.

Pulsed ultraviolet lasers coupled into a microscope can be used for micromanipulation of cells and subcellular structures. In addition, continuous infrared lasers can be used as ultrafine optical tweezers (or synonymously: optical trap). The pulsed UV lasers (for example excimer lasers or nitrogen lasers) can be used as optical scalpels for the preparation of protoplasts from plant root hairs. The precise microdissection of chromosomes with the laser microbeam provides access to chromosome segments where a specific gene is supported to be localized. From such segments, specific DNA libraries can be prepared for the search after such genes or markers in their environment. With the optical trap contact between effector cells of the immune system and their target cells can be established in a very simple and gentle way. The kinetics of the attack of a natural killer on an erythroleukemia cell can be studied from the first seconds after contact. Isolated plant cells as well as cells in a plant embryo tissue can be perforated and DNA or fluorescent molecules can be injected. From the temperature dependence of laser induced membrane lesions one can obtain predictions on laser induced cell fusion, which can be performed at slightly modified irradiation conditions under total microscopic control. Since focusing into the depth of a cell with an accuracy of better than a micrometer is possible, one can work on subcellular structures in the interior of a cell without opening it. For example, in rapeseed protoplasts subcellular structures such as mitochondria or chloroplasts can be perforated or moved out of their original position. Interestingly, such structures find their way back into the original position after the laser is switched off. From their speed one can obtain estimates on intracellular viscoelasticity.

[Simple alloplastic treatment of severe hip dysplasias and replacement operations in extreme loosening]. / Einfache alloplastische Versorgung schwerster Hüftdysplasien und Wechseloperationen bei extremer Auslockerung.

In extremely dysplastic hips the implantation of Judet's prothesis is rather simple, following the described technique. For exchange operations the author will not miss Judet's acetabular cup with screwbrim. Possible combination with the femoral part of Lord's type seems of essential advantage.

[Subcapital femoral osteotomy and invasive reposition of sudden total femur head displacement]. / Die subkapitale Femurosteotomie und blutige Reposition des plötzlichen totalen Hüftkopfabrutsches.

Full correction of extremely slipped heads of femora by subcapital osteotomy has the serious risk of necrosis (30%). Complications also may actually develop after Imhäuser's intertrochanteric osteotomy, doubtless in a smaller number of cases as described in own patients.

[Results of modified capitate bone dislocation in lunate bone malacia]. / Ergebnisse einer modifizierten Kapitatumverschiebung bei Lunatummalazie.

Long-term follow-up after simple "elongating osteotomy" of the capitate in aseptic necrosis of the lunate has failed to produce the good results which would clearly make this procedure the treatment of choice. The surprisingly high subjective evaluation does not correlate well with the prognostically poor X-ray appearances.

Necessarily disappointing results after tripleosteotomy in the dysplastic hip joint.

Not only the high risk of necrobiotic alterations in the acetabulum fragment, but more important the osteoarthritic signs and pains very few years after tripleosteotomy are cogent arguments against this measure. The bad results of tripleosteotomy are well explained by simple biomechanic causes.

[The individuality of weightbearing-patterns of human gait (author's transl)]. / Die Individualität der Belastungsmuster des menschlichen Ganges (Messungen der beim Gehen auftretenden Kräfte auf dem Boden).

Measurements have been carried out on a quartz-crystal multicomponent platform. The forces exerted by people walking on it could be measured as transverse, horizontal and vertical forces. The total was assessed mit the aid of the components. The torsion-element in the vertical axis was also measured. The patterns varied significantly with individuals. In general, pressures rose with walking speed. Individual patterns of movements, like elastic or stiff gait, showed clear differences. These are explained by the individual dynamic associated movements. These measurements do not permit direct conclusions as to weightbearing, but they demonstrate forces of dynamic movement. They do support the conclusion that static considerations of weightbearing, which omit the likely weightbearing-reducing forces of associated movements of the limbs, will give only a very fragmentary impression.