Expression profile of pattern recognition receptors in skeletal muscle of SOD1(G93A) amyotrophic lateral sclerosis (ALS) mice and sporadic ALS patients.

AIMS: Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of motoneurons and progressive muscle wasting. Inflammatory processes, mediated by non-neuronal cells, such as glial cells, are known to contribute to disease progression. Inflammasomes consist of pattern recognition receptors (PRRs), apoptosis-associated speck-like protein (ASC) and caspase 1 and are essential for interleukin (IL) processing and a rapid immune response after tissue damage. Recently, we described inflammasome activation in the spinal cord of ALS patients and in SOD1(G93A) ALS mice. Since pathological changes in the skeletal muscle are early events in ALS, we hypothesized that PRRs might be abnormally expressed in muscle fibre degeneration. METHODS: Western blot analysis, real-time PCR and immunohistochemistry were performed with muscle tissue from presymptomatic and early-symptomatic male SOD1(G93A) mice and with muscle biopsies of control and sporadic ALS (sALS) patients. Analysed PRRs include nucleotide-binding oligomerization domain-like (NOD-like) receptor protein 1 (NLRP1), NLR protein 3 (NLRP3), NLR family CARD domain-containing 4 (NLRC4) and absent in melanoma 2. Additionally, expression levels of ASC, caspase 1, interleukin 1 beta (IL1ß) and interleukin 18 (IL18) were evaluated. RESULTS: Expression of PRRs and ASC was detected in murine and human tissue. The PRR NLRC4, caspase 1 and IL1ß were significantly elevated in denervated muscle of SOD1(G93A) mice and sALS patients. Furthermore, levels of caspase 1 and IL1ß were already increased in presymptomatic animals. CONCLUSION: Our findings suggest that increased inflammasome activation may be involved in skeletal muscle pathology in ALS. Furthermore, elevated levels of NLRC4, caspase 1 and IL1ß reflect early changes in the skeletal muscle and may contribute to the denervation process.

[Nontuberculous mycobacterial infections]. / Infektionen mit nichttuberkulösen Mykobakterien.

Nontuberculous mycobacterial (NTM) are found ubiquitously in the environment and are usually of low pathogenicity. Infection occurs via inhalation of aerosols, and some species may cause severe infections. The incidence of NTM infections is rising worldwide. The risk of developing NTM disease depends on the susceptibility of the host as well as the frequency and duration of exposure. In addition to congenital immune deficiencies and immunosuppressive therapy, structural lung and systemic diseases, including rheumatoid arthritis (RA), are associated with an increased risk for NTM infections. The immune response to NTM is complex and relies on the interplay between professional phagocytes and lymphoid cells. This interplay is concerted by three key cytokines: interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Targeted immunotherapies, e. g., treatment with TNF inhibitors, interfere with these essential pathways and increase the risk of NTM infection significantly. This review focuses on the relationship between the immune response to NTM and intrinsic and iatrogenic dispositions for NTM infection, with an emphasis on RA.

[Immune response to Mycobacterium tuberculosis]. / Immunität gegen Mycobacterium tuberculosis.

Infections with Mycobacterium tuberculosis (MTB) induce complex immune responses involving an orchestrated interplay of innate and adaptive immune mechanisms. Why the immune system fails to eradicate the pathogen and at best achieves control of infection in the latent stage, still remains an unsolved mystery even more than 100 years after the discovery of MTB by Robert Koch. This article provides an overview of the current state of the art in the constantly evolving field of tuberculosis (TB) immunology. This review focuses on a change of paradigm proposing that in the latent stage MTB is anything but dormant and that latent TB is not merely a state of bacterial stasis but a state of dynamic bacterial and immunological equilibrium. The understanding of these dynamics is crucial for the development of new drugs against MTB as well as vaccines that aim to provide effective protection against the disease.

Anti-irritant and anti-inflammatory effects of glycerol and xylitol in sodium lauryl sulphate-induced acute irritation.

BACKGROUND: Glycerol is known to possess anti-irritant and hydrating properties and previous studies suggested that xylitol may also have similar effects. OBJECTIVE: Our aim was to study whether different concentrations of these polyols restore skin barrier function and soothe inflammation in sodium lauryl sulphate (SLS)-induced acute irritation. METHODS: The experiments were performed on male SKH-1 hairless mice. The skin of the dorsal region was exposed to SLS (5%) for 3 h alone or together with 5% or 10% of glycerol respectively. Further two groups received xylitol solutions (8.26% and 16.52% respectively) using the same osmolarities, which were equivalent to those of the glycerol treatments. The control group was treated with purified water. Transepidermal water loss (TEWL) and skin hydration were determined. Microcirculatory parameters of inflammation were observed by means of intravital videomicroscopy (IVM). Furthermore, accumulation of neutrophil granulocytes and lymphocytes, the expression of inflammatory cytokines and SLS penetration were assessed, as well. RESULTS: Treatment with the 10% of glycerol and both concentrations of xylitol inhibited the SLS-induced elevation of TEWL and moderated the irritant-induced increase in dermal blood flow and in the number of leucocyte-endothelial interactions. All concentrations of the applied polyols improved hydration and prevented the accumulation of lymphocytes near the treatment site. At the mRNA level, neither glycerol nor xylitol influenced the expression of interleukin-1 alpha. However, expression of interleukin-1 beta was significantly decreased by the 10% glycerol treatment, while expression of tumour necrosis factor-alpha decreased upon the same treatment, as well as in response to xylitol. Higher polyol treatments decreased the SLS penetration to the deeper layers of the stratum corneum. CONCLUSION: Both of the analysed polyols exert considerable anti-irritant and anti-inflammatory properties, but the effective concentration of xylitol is lower than that of glycerol.

Clinical status, psychosocial impairments, medical treatment and health care costs for patients with inflammatory bowel disease (IBD) in Germany: an online IBD registry.

BACKGROUND: The aim of this cross-sectional study was to establish an online inflammatory bowel disease (IBD) registry for a first picture of the situation of IBD outpatients' treatment in Germany. METHODS: Between March 2006 and July 2007 IBD outpatients from 24 gastroenterological specialist practices and two hospitals in Germany were enrolled in an Internet-based registry to evaluate the outpatients' clinical status, psychological impairments, provided health care, as well as medical treatment and medication costs. RESULTS: 1032 IBD patients (ulcerative colitis/UC: 519; Crohn's disease/CD: 511; indeterminate colitis: 2) were enrolled in the study (age: 43 ± 14 years/M ± SD). Disease duration of all patients averaged 10 ± 8.5 years. In 519 UC-patients (49% male; 33% pancolitis), 66% were in remission as were 55% of CD patients (37 % male; 41 % active smokers). Associated with higher rates of disease activity (CDAI ≥ 150; CAI>4) were corticosteroids (CD, UC), topical medication (UC), relevant reported depressive symptoms (15%; 6-31%) and impairments in sexuality (21%; 9-42%). Relevant medication groups prescribed were oral aminosalicylates (UC: 70%; CD: 47%); immunosuppressive therapy - mostly azathioprine/6 MP (CD: 47%; UC: 26%), and Infliximab (CD: 8%; UC: 3%). Strongly associated with their clinical disease activity in UC as well as CD patients, 15% (6-31%) reported relevant depressive symptoms and 21% (9-42%) relevant impairments in sexuality. CONCLUSIONS: The registry constitutes a large complemental database for the patient population in Germany. About one third of the IBD patients were not in clinical remission (CDAI ≥150/CAI >4) (CD: 45%; UC: 27%), although high rates of immunosuppressive drugs (CD: 47%; UC 26%) were administered. This study shows a large burden of active disease associated with an unexpectedly high (co)morbidity and high psychosocial impairments, indicating a reduced health state in IBD patients.

["Back pain coach". A project for patients with back pain]. / "Rücken-Coach". Ein Projekt für Patienten mit Rückenschmerzen.

QUESTION: Back pain is a challenge for case management but is a health insurance fund (HIF) that identifies high risk patients and includes them in a back pain assessment and a multimodal program cost-effective? METHODS: Case managers of a HIF contacted selected patients and requested information on pain and current perspectives. Patients in the intervention group were offered a multimodal assessment and, if applicable, a multimodal treatment program. Control group patients received verbal or written (back book) information. Cost data were evaluated with respect to the interview data 1 year prior and 1 year afterwards. FINDINGS: Of the 800 insured persons contacted 621 were nationwide, 88 were regional controls and 91 were intervention patients. Inability to work was still rising in all groups but less in the intervention group versus both control groups. Drugs, hospital as well as cure/adjuvant costs were less for intervention patients than in both control groups. The investment for the program was thus more than refinanced. INTERPRETATION: Case management was well accepted but the intervention was in need of training for case managers and the specific diagnostic and treatment option regionally. FUNDING: The HIF was responsible for the study investment and project partners shared the training of the HIF regional case managers.

Long-term beneficial effect of protease inhibitors on the intrinsic apoptosis of peripheral blood mononuclear cells in HIV-infected patients.

BACKGROUND: Viral suppression by antiretroviral therapy (ART) inhibits HIV-induced apoptosis and CD4 T-cell loss. It has been suggested that protease inhibitors (PIs) have nonviral antiapoptotic effects by maintaining mitochondrial integrity. Long-term clinical effects of PI-based ART on mitochondrial toxicity and lymphocyte apoptosis beyond viral suppression have not been exploited to date. METHODS: We conducted a 7-year study on HIV-1-infected patients from the Cologne HIV cohort with sufficient viral suppression under either a PI-based or nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen. Eight patients on PI and eight on NNRTI were eligible for inclusion in the analysis. The primary outcome measure was defined as a change in the mitochondrial-to-nuclear DNA ratio in PBMCs. Further key molecules involved in extrinsic [tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), Fas ligand (FasL) and caspase 8], intrinsic [B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase 9 and lactate-to-pyruvate ratio] and overall apoptosis [Annexin+/7-aminoactinomycin D (7-AAD)- and caspase 3/7] and viral activity [negative regulatory factor (Nef), interferon-α (IFN-α) and myxovirus resistance protein A (MxA)] were measured. RESULTS: Demographic and baseline clinical parameters were similar in the two groups, except that patients in the PI group had a higher mean age. After 7 years of treatment, CD4 T-cell count increased and the expression of genes encoding the proapoptotic viral protein Nef and HIV-induced cytokine IFN-α and its downstream effector MxA decreased in both groups. Focusing on the different pathways of apoptosis, only in the PI group intrinsic apoptosis decreased significant and in the inter-group comparison the decrease was significantly higher than in the NNRTI group. CONCLUSIONS: Our study provides evidence that long-term therapy with a PI-based regimen may be superior to that with a NNRTI-based regimen with regard to its intrinsic antiapoptotic effect.

Reactive oxygen species initiate luminal but not basal cell death in cultured human mammary alveolar structures: a potential regulator of involution.

Post-lactational involution of the mammary gland is initiated within days of weaning. Clearing of cells occurs by apoptosis of the milk-secreting luminal cells in the alveoli and through stromal tissue remodeling to return the gland almost completely to its pre-pregnant state. The pathways that specifically target involution of the luminal cells in the alveoli but not the basal and ductal cells are poorly understood. In this study we show in cultured human mammary alveolar structures that the involution process is initiated by fresh media withdrawal, and is characterized by cellular oxidative stress, expression of activated macrophage marker CD68 and finally complete clearing of the luminal but not basal epithelial layer. This process can be simulated by ectopic addition of reactive oxygen species (ROS) in cultures without media withdrawal. Cells isolated from post-involution alveoli were enriched for the CD49f(+) mammary stem cell (MaSC) phenotype and were able to reproduce a complete alveolar structure in subcultures without any significant loss in viability. We propose that the ROS produced by accumulated milk breakdown post-weaning may be the mechanism underlying the selective involution of secretory alveolar luminal cells, and that our culture model represents an useful means to investigate this and other mechanisms further.

Muscarinic receptor subtypes in cilia-driven transport and airway epithelial development.

Ciliary beating of airway epithelial cells drives the removal of mucus and particles from the airways. Mucociliary transport and possibly airway epithelial development are governed by muscarinic acetylcholine receptors but the precise roles of the subtypes involved are unknown. This issue was addressed by determining cilia-driven particle transport, ciliary beat frequency, and the composition and ultrastructural morphology of the tracheal epithelium in M1-M5 muscarinic receptor gene-deficient mice. Knockout of M3 muscarinic receptors prevented an increase in particle transport speed and ciliary beat frequency in response to muscarine. Furthermore, the ATP response after application of muscarine was blunted. Pretreatment with atropine before application of muscarine restored the response to ATP. Additional knockout of the M2 receptor in these mice partially restored the muscarine effect, most likely through the M1 receptor, and normalised the ATP response. M1, M4 and M5 receptor-deficient mice exhibited normal responses to muscarine. None of the investigated mutant mouse strains had any impairment of epithelial cellular structure or composition. In conclusion, M3 receptors stimulate whereas M2 receptors inhibit cilia-driven particle transport. The M1 receptor increases cilia-driven particle transport if the M3 and M2 receptors are missing. None of the receptors is necessary for epithelial development.

Adherence to thiopurine treatment in out-patients with Crohn's disease.

BACKGROUND: High frequency of incomplete or non-response to azathioprine (AZA) and/or mercaptopurine (MP) limit their use in Crohn's disease (CD). Non-adherence is considered to be of relevance for ineffectiveness. AIM: To assess adherence to thiopurines in CD out-patients treated in a single gastroenterology practice. METHODS: Patients were eligible for inclusion if they received AZA/MP for at least 3 months. After follow-up of 3 months, adherence to AZA/MP was assessed by quantitation of relevant thiopurine metabolite levels in red blood cells as well as by patients' self-report using standardized questionnaire. RESULTS: Sixty-five patients were prospectively included. Six patients (9.2%) had metabolite profiles indicative of non-adherence. Self-assessed questionnaire revealed non-adherence in four of 56 patients (7.1%). Therapeutic drug monitoring (TDM) and self-assessment as two independent methods had a concordance rate of 75%. Metabolite levels and self-assessed adherence were not significantly different between patients in remission compared with those with active disease. CONCLUSIONS: Out-patients with CD treated in a single gastroenterology practice had a satisfactory adherence (>90%) to thiopurine therapy. Different measures of adherence (TDM and self-report) applied to the same patient suggest comparable levels. TDM appears to be a reliable tool to assess adherence to thiopurines in clinical practice.

Anatomy of the lactating human breast redefined with ultrasound imaging.

The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast. The breasts of 21 fully lactating women (1-6 months post partum) were scanned using an ACUSON XP10 (5-10 MHz linear array probe). The number of main ducts was measured, ductal morphology was determined, and the distribution of glandular and adipose tissue was recorded. Milk ducts appeared as hypoechoic tubular structures with echogenic walls that often contained echoes. Ducts were easily compressed and did not display typical sinuses. All ducts branched within the areolar radius, the first branch occurring 8.0 +/- 5.5 mm from the nipple. Duct diameter was 1.9 +/- 0.6 mm, 2.0 +/- 90.7 mm and the number of main ducts was 9.6 +/- 2.9, 9.2 +/- 2.9, for left and right breast, respectively. Milk ducts are superficial, easily compressible and echoes within the duct represent fat globules in breastmilk. The low number and size of the ducts, the rapid branching under the areola and the absence of sinuses suggest that ducts transport breastmilk, rather than store it. The distribution of adipose and glandular tissue showed wide variation between women but not between breasts within women. The proportion of glandular and fat tissue and the number and size of ducts were not related to milk production. This study highlights inconsistencies in anatomical literature that impact on breast physiology, breastfeeding management and ultrasound assessment.

Cytokine and nitric oxide responses of monocyte-derived human macrophages to microsporidian spores.

Microsporidia are obligate intracellular parasites that emerged as opportunistic pathogens since the onset of the AIDS pandemic. They are capable of disseminating through the body using macrophages as vehicles. We incubated human macrophages with spores of all three Encephalitozoon spp. as well as with Vittaforma corneae, and the number of intracellular spores per cell was determined by fluorescence microscopy. Cell culture supernatants were collected and the content of TNF-alpha, INF-gamma, IL-10, and of nitric oxide was determined. Microsporidian spores did not induce a nitric oxide response in macrophages and there was a negative correlation between the number of intracellular spores and the amount of nitric oxide. TNF-alpha, INF-gamma, and IL-10 increased after simulation of macrophages with microsporidian spores but for TNF-alpha and INF-gamma no clear correlation of cytokine levels with the number of intracellular spores could be observed. A modulation of the nitric oxide response by intracellular microsporidia may contribute to the survival of microsporidia within the macrophage by a mechanism yet unknown.

The effect of supplementation with fish oil during pregnancy on breast milk immunoglobulin A, soluble CD14, cytokine levels and fatty acid composition.

BACKGROUND: Breast milk contains many immunomodulatory factors (soluble CD14 (sCD14), IgA and cytokines) with the potential to influence infant immune development. OBJECTIVE: To determine if changes in breast milk omega-3 polyunsaturated fatty acid (n-3 PUFA) composition as a result of maternal dietary fish oil supplementation during pregnancy can modify levels of these immunological parameters in breast milk. METHOD: In a randomized controlled trial, 83 atopic women received either 4 g fish oil capsules (containing 3.7 g n-3 PUFA) (n = 40) or 4 g olive oil capsules (n = 43) from 20 weeks gestation until delivery. Breast milk was collected 3 days post-partum and fatty acids were analysed by gas liquid chromatography and IgA, sCD14 and cytokines (IL-5, IL-6, IL-10, TNF-alpha and IFN-gamma) were quantitated by ELISA or time resolved fluorescence (TRF). RESULTS: Omega-3 docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3) levels were significantly higher (P < 0.001) in breast milk from women supplemented with fish oil (n = 33, DHA mean 1.15%, SD 0.47% and EPA mean 0.16%, SD 0.07%) than in samples from the control group (n = 40, DHA mean 0.50%, SD 0.17% and EPA mean 0.05%, SD 0.02%). Breast milk arachidonic acid (AA; 20:4n-6) levels were significantly lower (P = 0.045) in the fish oil group (mean 0.55%, SD 0.12%) compared with the control group (mean 0.61%, SD 0.14%). Breast milk IgA was positively correlated with DHA (P = 0.046) and 22:5n-3 (P = 0.003), but inversely correlated with linoleic acid (LA; 18:2n-6) (P=0.034). Levels of sCD14 were also positively correlated with 22:5n-3 (P=0.009). Cytokines involved in IgA synthesis (IL-10 and IL-6) were also significantly correlated with both IgA and n-3 PUFA levels, although there were no differences in the levels of breast milk IgA, sCD14 or cytokines between study groups. CONCLUSION: Supplementation with fish oil during pregnancy significantly alters early post-partum breast milk fatty acid composition. omega-3 PUFA levels were positively associated with IgA and sCD14 levels, suggesting a relationship between fatty acid status and mucosal immune function.

Nicotinic receptor mediated stimulation of NO-generation in neurons of rat thoracic dorsal root ganglia.

The contribution of nicotinic acetylcholine receptors (nAChRs) to stimulation of NO-production was investigated in isolated rat dorsal root ganglion (DRG) neurons utilizing an NO-sensitive fluorescent indicator 4,5-diaminofluorescein-diacetate (DAF-2DA) and appropriate channel blockers. RT-PCR and immunohistochemical analysis of NOS isoforms in cultured neurons revealed the expression of eNOS in the vast majority of neurons, nNOS in about 5-10%, and iNOS only exceptionally. Application of nicotine resulted in an abrupt increase in DAF-2T fluorescence in 65% of neuronal cell bodies that was fully sensitive to the general nAChR antagonist mecamylamine. Methyllycaconitine reduced the number of nicotine-sensitive neurons and the extent of NO-generation. Thus, alpha7- and/or alpha9/10-nAChRs are required for nicotine-induced NO-production in a subpopulation of DRG neurons, and appear to be partially involved in the remaining, larger subpopulation.

Unusual and severe symptomatic impairment of neutrophil function after one cycle of temozolomide in patients with malignant glioma.

Temozolomide, a recently approved cytotoxic agent for the treatment of malignant glioma, has shown promising results in the treatment studies published so far. However, cytopenia and related infectious complications have been reported in 2-8% of cases. Here we present three treatment-naive patients with malignant glioma experiencing cytopenia and/or infectious complications after the first cycle of temozolomide. Neutrophils obtained from each patient up to 6 weeks after the end of the temozolomide application showed normal phagocytic capacity but decreased oxygen radical production and thus impairment of microcidal activity. Our data suggest that a prolonged impairment of the immunological defense may occur in temozolomide-treated patients.

BEACOPP therapeutic regimen for patients with Hodgkin's disease and HIV infection.

BACKGROUND: Hodgkin's disease (HD) is the most common non-AIDS-defining tumor diagnosed in HIV-infected patients. Antineoplastic treatment is difficult considering the underlying immunodeficiency caused by HIV itself and may increase the risk of opportunistic infections. The purpose of this study was to evaluate the efficacy and safety of the chemotherapeutic regimen bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine and prednisone (BEACOPP) in HIV-infected patients with HD (HIV-HD). PATIENTS AND METHODS: Twelve patients with HIV-HD were scheduled to receive six cycles of BEACOPP. Five patients received concomitant antiretroviral therapy. Two patients received additional radiotherapy. Restaging was carried out after three and six cycles of chemotherapy. CD4 counts and HIV RNA levels were regularly monitored during the course of chemotherapy. RESULTS: Complete remission (CR) was achieved in all patients. Of 12 patients, eight patients received the intended six cycles of BEACOPP. Two patients died of opportunistic infections within the treatment period, one patient died of a relapse after 26 months. The other nine patients remain in CR for their individual follow-up period, median 49 months (range 13-108). The most commonly observed toxicity was bone marrow suppression with National Cancer Institute Common Toxicity Criteria (NCI-CTC) grade 3/4 leukopenia in 75% of all cases. The mean decline of CD4+ lymphocytes was 238 +/- 230/ micro l, with a mean recovery of 272 +/- 329/ micro l 6 months after the last cycle. Plasma levels of HIV RNA increased moderately or even declined under chemotherapy if highly active anti-retroviral therapy was given concomitantly with BEACOPP. CONCLUSIONS: The BEACOPP regimen is feasible and highly effective in HIV-HD patients. With respect to its overall moderate toxicity, BEACOPP is a safe regimen even in the immunocompromised patient.

Expression and distribution of vasoactive intestinal polypeptide receptor VPAC(2) mRNA in human airways.

SUMMARY: Vasoactive intestinal polypeptide (VIP) is a putative neurotransmitter of the inhibitory non-adrenergic non-cholinergic nervous system and influences many aspects of mammalian airway function. VIP binds to two G-protein-coupled VPAC receptors that are highly homologous structurally but distinguished by their different affinities for peptide analogues of VIP. As VIP binding sites in the respiratory tract have only been examined by ligand binding and cytochemical techniques, we studied the distribution of the mRNA that encodes the inducible receptor subtype VPAC(2) in the human respiratory tract. Northern blots demonstrated the expression of VPAC(2) mRNA in human airways and other tissues. A human-specific VPAC(2) cRNA probe was used to detect VPAC(2) mRNA expression in human lung by nonradioactive in situ hybridization. In larger airways, positive VPAC(2) mRNA signals were localized to tracheal and bronchial ciliated epithelial cells. There was also marked staining of mucous and serous cells of submucosal glands. No signals were obtained in airway and vascular smooth muscle myocytes and endothelial cells. In peripheral lung tissues, VPAC(2) mRNA expression was localized to epithelial cells of the bronchioles. Specific staining was detected in immune cells and alveolar macrophages. In summary, VPAC(2) is localized in airway epithelial, glandular, and immune cells of the lung but not in airway and vascular smooth muscle. The absence of VPAC(2) mRNA in vascular and airway smooth muscle myocytes may indicate that the effects of VIP on vasodilation and bronchodilation are mediated by VPAC(1) or undefined receptors. However, a paracrine modulation of the two most prominent effects of VIP in the respiratory tract by VPAC(2) cannot be excluded.

Randomized controlled monocentric comparison of once daily ceftriaxone with tobramycin and cefotaxime three times daily with tobramycin in neutropenic fever.

A prospective, randomized, controlled monocentric trial was performed to evaluate the efficacy and safety of once daily ceftriaxone 2 g plus tobramycin 5 mg/kg in comparison to cefotaxime 2 g t.i.d. plus tobramycin 5 mg/kg qd in the treatment of neutropenic fever. In cases of fever > or = 38.5 degrees C and a neutrophil count below 1000/microliter, patients with hematological malignancies were assigned to ceftriaxone or cefotaxime, each with tobramycin. The primary endpoint was defined as defervescence < 37.5 degrees C on day 4-6 followed by at least 7 afebrile days. Secondary endpoints were overall response, defined as defervescence on day 25 and toxicity. There were 160 episodes of 114 patients included. Fever of unknown origin accounted for 79 episodes (51%), microbiologically defined infection for 36 (23%), clinically defined infection for 27 (17%), and both clinically and microbiologically defined infection for 14 episodes (9%). On an intent-to-treat basis 156 episodes could be evaluated for the primary endpoint. Ceftriaxone plus tobramycin and cefotaxime plus tobramycin resulted in a primary response in 46.9% and 45.3%, respectively. Overall response was achieved on study day 25 in 87.7% and 80%, respectively. No significant difference in toxicity was observed. Once-daily ceftriaxone plus tobramycin was not inferior to cefotaxime t.i.d. plus tobramycin qd in the empirical treatment of neutropenic fever.