A phase II study of a human anti-PDGFRα monoclonal antibody (olaratumab, IMC-3G3) in previously treated patients with metastatic gastrointestinal stromal tumors.

Background: This study evaluated tumor response to olaratumab (an anti-PDGFRα monoclonal antibody) in previously treated patients with metastatic gastrointestinal stromal tumor (GIST) with or without PDGFRα mutations (cohorts 1 and 2, respectively). Patients and methods: Patients received olaratumab 20 mg/kg intravenously every 14 days until disease progression, death, or intolerable toxicity occurred. Outcome measures were 12-week tumor response, progression-free survival (PFS), overall survival (OS), and safety. Results: Of 30 patients enrolled, 21 patients received ≥1 dose of olaratumab. In the evaluable population (cohort 1, n = 6; cohort 2, n = 14), no complete response (CR) or partial response (PR) was observed. Stable disease (SD) was observed in 3 patients (50.0%) in cohort 1 and 2 patients (14.3%) in cohort 2. Progressive disease (PD) was observed in 3 patients (50.0%) in cohort 1 and 12 patients (85.7%) in cohort 2. The 12-week clinical benefit rate (CR + PR + SD) (90% CI) was 50.0% (15.3-84.7%) in cohort 1 and 14.3% (2.6-38.5%) in cohort 2. SD lasted beyond 12 weeks in 5 patients (cohort 1, n = 3; cohort 2, n = 2). Median PFS (90% CI) was 32.1 (5.0-35.9) weeks in cohort 1 and 6.1 (5.7-6.3) weeks in cohort 2. Median OS was not reached in cohort 1 and was 24.9 (14.4-49.1) weeks in cohort 2. All patients in cohort 1 and 9 (64.3%) in cohort 2 experienced an olaratumab-related adverse event (AE), most commonly fatigue (38.1%), nausea (19.0%), and peripheral edema (14.3%). Two grade ≥3 olaratumab-related events were reported (cohort 1, syncope; cohort 2, hypertension). Conclusions: Olaratumab had an acceptable AE profile in patients with GIST. While there was no apparent effect on PFS in patients without PDGFRα mutations, patients with PDGFRα-mutant GIST (all with D842V mutations) treated with olaratumab had longer disease control compared with historical data for this genotype. ClinicalTrials.gov Identifier: NCT01316263.

Open-label, randomized study of individualized, pharmacokinetically (PK)-guided dosing of paclitaxel combined with carboplatin or cisplatin in patients with advanced non-small-cell lung cancer (NSCLC).

BACKGROUND: Variable chemotherapy exposure may cause toxicity or lack of efficacy. This study was initiated to validate pharmacokinetically (PK)-guided paclitaxel dosing in patients with advanced non-small-cell lung cancer (NSCLC) to avoid supra- or subtherapeutic exposure. PATIENTS AND METHODS: Patients with newly diagnosed, advanced NSCLC were randomly assigned to receive up to 6 cycles of 3-weekly carboplatin AUC 6 or cisplatin 80 mg/m(2) either with standard paclitaxel at 200 mg/m(2) (arm A) or PK-guided dosing of paclitaxel (arm B). In arm B, initial paclitaxel dose was adjusted to body surface area, age, sex, and subsequent doses were guided by neutropenia and previous-cycle paclitaxel exposure [time above a plasma concentration of 0.05 µM (Tc>0.05)] determined from a single blood sample on day 2. The primary end point was grade 4 neutropenia; secondary end points included neuropathy, radiological response, progression-free survival (PFS) and overall survival (OS). RESULTS: Among 365 patients randomly assigned, grade 4 neutropenia was similar in both arms (19% versus 16%; P = 0.10). Neuropathy grade ≥2 (38% versus 23%, P < 0.001) and grade ≥3 (9% versus 2%, P < 0.001) was significantly lower in arm B, independent of the platinum drug used. The median final paclitaxel dose was significantly lower in arm B (199 versus 150 mg/m(2), P < 0.001). Response rate was similar in arms A and B (31% versus 27%, P = 0.405), as was adjusted median PFS [5.5 versus 4.9 months, hazard ratio (HR) 1.16, 95% confidence interval (CI) 0.91-1.49, P = 0.228] and OS (10.1 versus 9.5 months, HR 1.05, 95% CI 0.81-1.37, P = 0.682). CONCLUSION: PK-guided dosing of paclitaxel does not improve severe neutropenia, but reduces paclitaxel-associated neuropathy and thereby improves the benefit-risk profile in patients with advanced NSCLC. CLINICAL TRIAL INFORMATION: NCT01326767 (https://clinicaltrials.gov/ct2/show/NCT01326767).

Liposarcoma of the Spermatic Cord: Impact of Final Surgical Intervention--An Institutional Experience.

BACKGROUND: Paratesticular liposarcomas are almost always mistakenly diagnosed as inguinal hernias subsequently followed by inadequate operation. METHODS: 14 consecutive patients with paratesticular liposarcoma were retrospectively reviewed. Preoperative management was evaluated. Disease-free and overall survival were determined. RESULTS: In 11 patients primary and in 3 patients recurrent liposarcoma of the spermatic cord were diagnosed. Regarding primary treatment in primary surgical intervention resection was radical (R0) in 7 of 14 (50%) patients, marginal (R1) in 6 (43%) patients, and incomplete with macroscopic residual tumour (R2) in 1 (7%) patient. Primary treatment secondary surgical intervention was performed in 4 patients: resection was radical (R0) in 3 (75%) patients and marginal (R1) in 1 (25%) patient. Regarding secondary treatment in recurrent disease resection was marginal (R1) in 3 patients (100%). Final histologic margins were negative in 10 patients with primary disease (71%) and positive in 4 patients with subsequent recurrent disease. After radical resection disease-free survival rates at 3 years were 100%. Overall survival at 4.5 years (54 (18-180) months) was 64%. CONCLUSION: An incomplete first surgical step increases the number of positive margins leading to local recurrences and adverse prognoses. Aggressive surgery should be attempted to attain 3-dimensional negative margins.

[Pulmonary infection in neutropenia]. / Pulmonale Infektion bei Neutropenie - Fall 1/2015.

UNLABELLED: MEDICAL HISTORY AND CLINICAL COURSE: A 42-year-old patient with hairy cell leukemia had been treated for 3 years by a hematologist in private practice. Initially the patient received 1 course of cladribine upon which the disease went into complete remission. 6 weeks ago a relapse was diagnosed and combination therapy with cladibrin and rituximab was initiated. Now the patient presented to the emergency room with shortness of breath and pain when breathing. INVESTIGATIONS, TREATMENT AND COURSE: In the chest x-ray, patchy infiltrates and pleural effusions were found on both sides. The subsequently performed computed tomography showed bilateral compactions with an Halo suspicious for fungal infiltrates. Upon admission to the hospital, an empirical antibiotic therapy with clarithromycin and piperacillin/tazobactam was initiated, which was later escalated to meropenem and linezolid. Additionally, an antifungal therapy with voriconazole was started and later switched to liposomal amphotericin B. At his admission, a positive aspergillus antigen could be detected in the microbiological laboratory. Under antimycotic treatment the aspergillus antigen was repeatedly negative. The patient presented with pronounced cytopenias and after a switch of therapy to vemurafenib and filgrastim, the hematopoiesis could only be stimulated insufficiently. The patient was transferred to the intensive care unit three days after admission with severe respiratory failure. He died on day 8 after admission. AUTOPSY AND DIAGNOSIS: Diagnosis was consistent with relapse of hairy cell leukemia with positive BRAF mutation and a bone marrow infiltration > 80 %. Autopsy revealed a significant hepato-splenomegaly, a lack of erythro-, granulo- and thrombopoiesis. Clots interspersed with fungal hyphae were found in both lungs and an infarction of the spleen with evidence of fungal hyphae was detected. The cultural findings post mortem on yeast or mold were negative. CONCLUSION: Patients with refractory hairy cell leukemia and prolonged neutropenia are at increased risk for systemic fungal infections. Therefore, prohylactic antimycotic therapy should be considered early in this group of patients. The therapeutic approach of vemurafenib in treatment-refractory hairy cell leukemia is promising and offers an additional treatment option. In the present case, the patient could unfortunately not be stabilized due to the septic complications.

[Gastrointestinal stromal tumours bigger than 20 cm: experience with imatinib chemotherapy in neoadjuvant intention]. / Gastrointestinale Stromatumore größer als 20 cm: Erfahrungen mit Imatinib in neoadjuvanter Intention.

The size of the primary tumour is considered the most important risk factor for the development of metastasis or local recurrence in case of gastrointestinal stromal tumour (GIST). Until now no prospective data are available in the literature about the role of neadjuvant therapy with Imatinib. Between 2009 and 2012 seven patients with a giant GIST > 20 cm underwent a neadjuvant treatment with Imatinib, a radical operation, followed by an adjuvant therapy. These patients were controlled with regard to peri- and postoperative morbidity and disease-free survival. Two patients were considered not resectable and one patient showed liver metastasis at the time of diagnosis. RECIST responses to the neoadjuvant Imatinib were: 2/7 patients with stable disease, 3/7 partial response, 2/7 partial response with down-staging (resectable disease). Because of the following tumour localisations (6 gastric and 1 rectal), six gastrectomies (one en-bloc with left pancreas) and one Holm operation were performed. The patient with simultaneous liver metastasis developed a tumour progression during the follow-up but the others are still tumour free after 2 years. We detected a significant tumour volume regression due to the neadjuvant chemotherapy in cases of GIST > 20 cm (30 %). Our series showed good results for a neadjuvant therapy in cases of giant GIST with the achievement of 100 % R0 resection without a high morbidity rate (in the literature a tumor size > 10 cm and poor localisation is associated to a high risk of R1 - 2 and high morbidity). Peri- and postoperative morbidity are acceptable and the tumour free survival at 2 years is 85 %.

Effect of concurrent chemotherapy and hyperthermia on outcome of preoperative radiotherapy of high-risk soft tissue sarcomas.

BACKGROUND AND PURPOSE: As treatment results for high-risk soft tissue sarcoma are still disappointing, treatment intensification is warranted. We performed a retrospective analysis of multimodal preoperative treatment to evaluate the additional effect of concurrent chemotherapy and/or locoregional hyperthermia in comparison to radiotherapy alone. PATIENTS AND METHODS: Between 1999 and 2011, 28 patients were treated with neoadjuvant radiotherapy to a median 45 Gy for high-risk soft tissue sarcoma. All tumors were deep-seated and grade 2 or 3, 86% (n = 24) larger than 5 cm. Multimodal treatment (n = 12) consisted of ifosfamide (n = 7), locoregional hyperthermia (n = 3), or both modalities (n = 2) concurrent to radiotherapy. RESULTS: Prognostic factors (grade, size, histology, location) were balanced in the groups with and without concurrent multimodal treatment. There was a significant improvement of disease-specific survival (100% vs. 70% at 3 years, p = 0.03) with multimodal treatment. Distant metastases-free survival was influenced, but was not statistically significant. Local control and disease-free survival did not differ in the two groups. CONCLUSION: Our data suggest that multimodal treatment with ifosfamide and/or locoregional hyperthermia in combination with neoadjuvant radiotherapy might improve outcome in high-risk soft tissue sarcomas.

Pemetrexed in patients with refractory soft tissue sarcoma: a non-comparative multicenter phase II study of the German Sarcoma Group AIO-STS 005.

BACKGROUND: This study evaluated efficacy and safety of pemetrexed in patients with refractory soft tissue sarcoma. METHODS: Patients received pemetrexed intravenously at a dose of 500 mg/m² every 21 days until progression or unacceptable toxicity. The primary endpoint was objective tumor response. RESULTS: Fourty-eight of 53 screened patients were included and received a total of 200 cycles (median 2; range 1-30). Median age was 53 years (range, 20-81). The observed toxicity profile was favorable. NCI-CTC hematologic grade 3/4 toxicity consisted of neutropenia in 13 %, anemia in 15 %, and febrile neutropenia in 4 % of patients of patients, respectively. Non-hematologic CTC grade 3/4 toxicity consisted of elevated ASAT/ALAT in 10 %, hyperglycemia in 6 %, infection with or without neutropenia in 6 %, nausea in 2 % and stomatitis in 2 % of patients. No other grade 3 toxicities and no treatment-related toxic deaths were observed. Overall response as defined by RECIST was 5 %, 16 patients experienced stable disease (40 %). The estimated 3- and 6-months progression-free rates were 33.3 % and 14.6 %, respectively. CONCLUSIONS: In patients with refractory STS, pemetrexed is well tolerated and moderately effective. The confirmed objective response rate in STS is low, however, disease stabilizations are seen in a high proportion of patients (ClinicalTrials.gov NCT00427466).

Clear-cell sarcoma of the soft tissue--a rare diagnosis with a fatal outcome.

Clear-cell sarcomas account for less than 1% of all soft tissue tumours. They most often occur in middle-aged adults as a deeply located lesion with predilection to the tendons and aponeuroses. The aim of the present study was to show possible influencing factors on the outcome after surgical treatment in a detailed case series. We reviewed the medical records of 11 patients with the diagnosis of a clear-cell sarcoma of the soft tissue. These cases were analysed with regard to age, gender, localisation, tumour size, recurrence free survival and overall survival. A minimum follow up of 12 months was achieved. The mean age at the point of diagnosis was 47.9 years. Metastases occurred after a mean of 19.2 months. In the cases with a tumour diameter >5 cm, metastases occurred earlier. When treated in a specialist centre, metastases occurred later. Patients died a mean of 18.4 months after developing metastatic disease. Patients with tumour size >5 cm at the point of primary diagnosis died earlier than patients with a tumour size <5 cm. It is important to detect clear-cell sarcomas as soon as possible and the final surgical treatment should be performed in a centre familiar with the treatment of soft tissue tumours not only to prolong overall survival, but also to treat the patient in a multiprofessional team.

Contamination of autologous peripheral blood progenitor cell grafts predicts overall survival after high-dose chemotherapy in multiple myeloma.

BACKGROUND: Despite of the introduction of novel treatment modalities for multiple myeloma, high-dose chemotherapy with hematopoietic stem-cell rescue is still considered the standard of care for eligible patients <65 years of age. As we have previously reported, stem-cell grafts regularly contain quantities of plasma cells measurable by flow cytometry. However, the pathogenetic significance of this finding remains unknown. METHODS: Multiple myeloma patients (n = 60) were mobilized with chemotherapy and filgrastim. Peripheral blood stem cell grafts were obtained by standard leukapheresis, and the number of CD38++/CD138+ cells/kg was determined by flow cytometry. Plasma cell contamination above a threshold of 4.5 x 10(5) plasma cells/kg was considered "high", whereas lower quantities of plasma cells or absent plasma cells in the graft were considered "low". RESULTS: Progression-free survival: the median statistical progression-free survival was 33.5 months (range 11-99 months) in the high-contamination group (n = 16) versus 47 months (range 8-148 months) in the low-contamination group (n = 44). This difference turned out not to be statistically significant (P = 0.15). However, the difference was highly significant regarding overall survival with 53 months (range 11-119 months) in the high-contamination group and with 114 months (range 8-158 months) in the low-contamination group (P = 0.012). CONCLUSIONS: Patients with >4.5 x 10(5) plasma cells/kg contaminating the peripheral blood stem cell graft received after high-dose chemotherapy have a significantly reduced overall survival. Whether high contamination of grafts with plasma cells might reflect residual in vivo tumor mass prior to stem cell transplantation and a generally more aggressive behavior of malignant myeloma cells in these patients, or whether reinfused plasma cells contribute to an unfavorable course of disease remains to be determined.

Beta-galactosidase staining on bone marrow. The osteoclast pitfall.

The enzyme beta-galactosidase, encoded by the bacterial gene lac-Z, is commonly used as a histochemical reporter to track transplanted cells in vivo or to analyze temporospatial gene expression patterns by coupling expression of specific target genes to beta-galactosidase activity. Previously, endogenous beta-galactosidase activity has been recognized as a confounding factor in the study of different soft tissues, but there is no description of the typical background on bone marrow sections when using the chromogenic substrate 5-Bromo-4-chloro-3-indolyl beta-D-Galactoside (X-Gal). In this report, we show that osteoclasts in bone marrow sections specifically and robustly stain blue with X-Gal. This leads to a typical background when bone marrow is examined that is present from the first day post partum throughout the adult life of experimental mice and can be confused with transgenic, bacterial beta-galactosidase expressing hematopoietic or stromal cells. Experimental variations in the X-Gal staining procedure, such as pH and time of exposure to substrate, were not sufficient to avoid this background. Therefore, these data demonstrate the need for strenuous controls when evaluating beta-galactosidase positive bone marrow cells. Verifiable bacterial beta-galactosidase positive bone marrow cells should be further identified using immunohistological or other approaches. Specifically, beta-galactosidase positive hematopoietic or stromal cells should be proven specifically not to be osteoclasts by co-staining or staining adjacent sections for specific markers of hematopoietic and stromal cells.

Thrombopoietic cells and the bone marrow vascular niche.

Megakaryocytes and platelets have been known to secrete angiogenic growth factors for a long time. However, there is little in vivo data on the regulation of angiogenesis by thrombopoietic cells. Both megakaryocytes and platelets are known to carry and release a multitude of both pro- and antiangiogenic mediators. Thus, it remained unknown how the "angiogenic phenotype" of thrombopoietic cells would be determined. Our group established that platelets contribute to angiogenesis as carriers of SDF-1, which is released by platelets in response to stimulation with hematopoietic cytokines. Indeed, even the action of VEGF-A seems to be mediated in part by the release of SDF-1 from stimulated platelets, thereby attracting proangiogenic hematopoietic cells. Moreover, the analysis of murine plasma and serum showed that similar to VEGF-A, SDF-1 is almost exclusively derived from platelets, and only trace amounts are detectable in platelet poor plasma. Because tumor patients' platelets have been shown to contain lower amounts of thrombospondin (Tsp), we generated Tsp-1 and Tsp-2 double knockout mice by crossing the single knockout lines. Interestingly, megakaryocytes and platelets derived from these mice confer a proangiogenic phenotype both in the bone marrow and in reperfusion of ischemic hindlimbs, thereby verifying the hypothesis of pro- and antiangiogenic platelet constituents "in balance."

Rituximab consolidation after high-dose chemotherapy and autologous blood stem cell transplantation in follicular and mantle cell lymphoma: a prospective, multicenter phase II study.

BACKGROUND: Patients with follicular (FL) or mantle cell lymphoma (MCL) are incurable with conventional therapy. We investigated the safety and efficacy of rituximab consolidation after autologous stem cell transplantation (ASCT) in order to prevent relapse by clearance of minimal residual disease (MRD). METHODS: Rituximab was given approximately 8 weeks after CD34+ cell enriched ASCT at 375 mg/m2, weekly for 4 weeks. Monitoring of MRD was performed by repetitive PCR analyses. RESULTS: Thirty-one patients were included; one died early after ASCT before rituximab administration. Thirty patients (20 FL, 10 MCL) were evaluable after rituximab consolidation, and 27 of these were assessable for MRD detection. Rituximab consolidation post-ASCT was safe, the most common toxicity being infection. At a median follow-up of 42 months (range 13-96) after ASCT, 25 patients were censored with an actuarial event-free survival (EFS) of 81% at 4 and 5 years. Four patients (two FL, two MCL) relapsed, and one additional MCL patient died unexpectedly in complete remission. PCR-negativity was observed in 22% of the patients before ASCT, 53% post-ASCT (P=0.0547), 72% after rituximab (P=0.0018) and 100% at 6 months post-transplant (P < 0.001). CONCLUSIONS: One single course of rituximab consolidation given after ASCT is safe, may help to eliminate MRD and may translate into improved EFS in both FL and MCL patients.

Hypersensitivity pneumonitis associated with the use of trofosfamide.

Trofosfamide (Ixoten; Baxter Oncology, Germany) is an alkylating agent that, as with other oxazaphosphorine derivatives, has to be activated by hepatic cytochrome P450 oxidases. The bioavailability is nearly 100% after oral application, and the main metabolites are 4-hydroxytrofosfamide, and 4-hydroxyifosfamide. The main side-chain metabolites ifosfamide and cyclophosphamide can be further activated by oxidation and formation of their respective phosphoramide mustards. Oral continuous low-dose therapy has been the most widely used schedule. The toxicity profile consists mainly of dose-dependent hematotoxicity and, rarely, hemorrhagic cystitis. Nausea and vomiting are infrequently seen. Higher grades of nephrotoxicity or neurotoxicity--side-effects that typically limit the use of ifosfamide-have not been reported with low-dose continuous trofosfamide treatment. We report herein a case of a 83-year-old female patient with a disseminated malignant peripheral nerve sheath tumor treated with trofosfamide developing pulmonal toxicity. To our knowledge, this is the first reported case of exogenous allergic alveolitis after exposure to this drug.

Correlations between hematopoietic progenitor cell counts as measured by Sysmex and CD34+ cell harvest yields following mobilization with different regimens.

PURPOSE: The Sysmex SE-9000 cell counter provides an estimate of immature cells referred to as hematopoietic progenitor cells (HPC). HPC counts should correlate with CD34+ counts in mobilized peripheral blood and apheresis to allow optimization of apheresis timing. METHODS: We correlated the HPC counts as measured in the immature information channel with CD34+ cell levels as determined by FACS (HPCA-2 antibody, Becton Dickinson) from mobilized peripheral blood in 40 samples (27 patients and three healthy donors) and in aphereses ( n=113, 41 patients and 20 healthy donors). RESULTS: In mobilized blood, HPC counts were correlated with CD34+ cells ( r=0.78, P<0.0001, n=40). The HPC counts were about 1.5-fold higher than CD34+ cell counts with a median (range) of 84 (1-747)/microl and 57 (1-370)/microl, respectively. In CD34+ selected cell preparations ( n=8), HPC counts were about fourfold lower than CD34+ cell counts with a median (range) of 179 (67-693)/microl and 760 (191-4309)/microl, respectively. In apheresis preparations, linear regression analyses were performed for the group of stem cell donors ( n=44), the group of lymphoma patients ( n=23), the multiple myeloma group ( n=21), and the group of solid tumors ( n=25). Interestingly, no correlation between HPC counts and CD34+ cell counts was found in the G-CSF-mobilized healthy donor group ( r=0.23, P=0.13). Pairing of HPC counts and CD34+ counts was effective in the group of patients receiving chemotherapy + G-CSF for stem cell mobilization: lymphoma group ( r=0.67, P=0.0005), multiple myeloma group ( r=0.56, P=0.008), and the group of solid tumors ( r=0.52, P=0.007). CONCLUSIONS: Lymphoma and multiple myeloma patients who were moderately pretreated and mobilized with chemotherapy and G-CSF showed the best results in correlation analyses even at low HPC counts. Therefore, HPC measurement can be used for timing of apheresis in these patients.

[In the grey area body body, psyche and social difficulties. I: New developments in diagnosis and therapy of somatoform disorders (exemplified by chronic pain patients)]. / Im Graubereich zwischen Körper, Psyche und sozialen Schwierigkeiten. Teil I: Neue Entwicklungen in der Diagnose und Therapie von somatoformen Störungen (am Beispiel von chronischen Schmerzpatienten).

The so-called psychosomatic or functional conditions (notably somatoform pain disorders) often cause difficulties in diagnostic classification, clinical management and assessment of disability. Recent trends in diagnosis are reviewed. We describe our first clinical experience of interdisciplinary evaluation of pain patients by functional capacity evaluation and an ergonomically oriented rehabilitation program. This interdisciplinary approach could constitute a new field of close collaboration between physiatry/physical medicine, physiotherapy and psychiatry.

[In the gray area between body, psyche and social difficulties. II: Psychiatric assessment of somatoform disorders (exemplified by chronic pain patients]. / Im Graubereich zwischen Körper, Psyche und sozialen Schwierigkeiten. Teil II: Die psychiatrische Begutachtung von somatoformen Störungen (am Beispiel von chronischen Schmerzpatienten).

Medico-legal assessment for long-term disability benefits in patients with mainly somatoform pain disorders is in increasing demand. Since impairment does not explain the loss of function in somatoform disorders, the expert must determine to what extent the patient is able to cope more actively with pain in order to attain a higher level of functioning. Consistency of behavioral signs, flexibility and initiative in the way of coping are helpful criteria in this respect. Special attention is given to problems in the assessment of migrants with these disorders. We strongly support the concept of an interdisciplinary approach in medico-legal assessment. Postgraduate medical training in this field should receive greater attention accordingly.

Effect of isosorbiddinitrate on exogenously expressed slowly activating K+ channels and endogenous K+ channels in Xenopus oocytes.

1. The effects of isosorbiddinitrate (ISDN) were tested on membrane currents and resting potential in Xenopus laevis oocytes which were either uninjected or injected with cRNA encoding for K+ channels from three distinct families (slowly activating IsK channels, delayed-rectifying Kv1.1 or inwardly rectifying IRK1 K+ channels). 2. In uninjected oocytes ISDN (1 mM) resulted in a decrease of the holding current at potentials more positive than -100 mV and in an increase at potentials below -100 mV. Increasing extracellular K+ to 100 mM shifted the reversal potential for ISDN-mediated effects to approximately -12 mV, suggesting an inhibition of a K+ conductance by ISDN. 3. In current clamp studies ISDN (1 mM) and Ba2+ (3 mM) depolarized cell membrane. ISDN and Ba2+ had no additive effects on membrane potential when applied simultaneously. In voltage clamp studies, corresponding results were observed for the effects of ISDN and Ba2+ on the holding current with an apparent K(m) of 0.21 and 0.08 mM, respectively. 4. In contrast to ISDN, the nitric oxide (NO) donors isosorbidmononitrate (ISMN) and S-nitrosocysteine (SNOC) had no effects on the holding currents in Xenopus oocytes. Moreover, the guanylate inhibitor LY 83583 did not affect ISDN-mediated holding current alterations, suggesting that ISDN acts independently of the second messenger NO. 5. ISDN inhibited exogenously expressed IsK channels with an apparent K(m) of 0.15 mM, but at 1 mM only weakly inhibited Kv1.1 and IRK1 channels. 6. It is concluded that ISDN inhibits an endogenous K+ conductance in Xenopus oocytes with a similar potency to that shown by expressed IsK channels. These effects are independent of the second messenger NO.

[Loss of bone mass in patients with anorexia on tube feeding and its prevention with biphosphonates]. / Knochensubstanzverlust bei Anorexie-Patientinnen unter Sondenernährung und dessen Prävention mit Bisphosphonaten.

Women with long-lasting anorexia nervosa often display osteopenia. Furthermore, we have observed additional marked loss of bone mass under tube feeding in underweight anorexia patients. Such loss of bone substances can lead to spontaneous fractures. Therefore, we investigated in this study whether this undesirable effect of tube-feeding might be prevented by administration of bisphosphonates (Didronel), a substance that inhibits the activity of osteoclasts. Bone density was assessed by a high-precision, low dose, quantitative computed tomography of the distal radius and the distal tibia. A group of 6 anorexia patients (tube feeding with an initial underweight of 74.9 +/- 10.3% of ideal weight, mean +/- SD) treated with bisphosphonates showed only slight loss of trabecular bone (0.8 +/- 0.2%, mean +/- SEM) after 2 months of observation, whereas in 2 control groups a marked diminution of trabecular bone was observed (4.4 +/- 0.7% and 7.6 +/- 1.1% respectively, p less than 0.001 for each comparison). Cortical bone was unchanged throughout. Treatment with bisphosphonates provides effective prevention of bone loss observed in tube-feeding.