Structure and phase transitions in Ca2CoSi2O7-Ca2ZnSi2O7 solid-solution crystals.

While the incommensurability in melilites is well documented, the underlying atomic configurations and the composition-dependent phase behavior are not yet clear. We have studied the transition from the incommensurate phase to the high-temperature normal phase (IC-N), and to the low-temperature commensurate phase (IC-C) of selected members of the Ca(2)Co(1 - x)Zn(x)Si(2)O(7) system using X-ray and single-crystal electron diffraction, as well as calorimetric measurements. The space group of the unmodulated normal phase and of the basic structure of the incommensurate phase is P42(1)m; the commensurate lock-in superstructure was refined as a pseudomerohedral twin in the orthorhombic space group P2(1)2(1)2. We found that the commensurate modulation is mainly connected with a sawtooth-like periodicity of rotations of the T(1) tetrahedra in the 3 x 3 superstructure. In this structure, the clustering of the low-coordinated Ca(2+) ions is not complete so that only imperfect octagons were detected. Generally, the effect of increasing substitution of Co by Zn was a continuous reduction of the IC-N and IC-C transition temperatures.

Transition from the incommensurately modulated structure to the lock-in phase in Co-åkermanite.

The adaptation of the incommensurate structure modulation in Ca(2)CoSi(2)O(7) (dicalcium cobalt disilicate) single crystals to decreasing temperature has been examined using in situ high-resolution transmission electron microscopy and electron diffraction. The transition from the incommensurate to the commensurate lock-in phase of Co-åkermanite exhibits a pronounced hysteresis of a highly strained metastable state with a characteristic microdomain morphology. A network of domain walls surrounding single orientation domains develops out of the room-temperature tartan pattern, the domains increase in size and their alignment changes from crystallographic to random. At 100 K the phase transition becomes almost complete. In parallel, the evolution of the modulation structure can be described by a change from a loose arrangement of octagonal tilings into a close-packed configuration of overlapping octagons in the commensurate low-temperature lock-in phase. Thereby, the octagon represents the ordered distribution of low-coordinated Ca clusters within a nanodomain extending over 4 x 4 subunits, on average [Riester et al. (2000). Z. Kristallogr. 215, 102--109]. The modulation wavevector was found to change from q(1,2) = 0.295 (a* +/- b*) at 300 K to q(1,2) = 0.320 (a* +/- b*) at 100 K.

CD40 stimulation promotes human secondary immunoglobulin responses in HuPBL-SCID chimeras.

Antibodies to CD40 have been demonstrated to promote B-cell growth and differentiation in vitro. In order to determine if CD40 stimulation could promote antigen-specific human immunoglobulin (Ig) production in vivo, we examined the effects of anti-human CD40 MoAb in an in vivo system where human peripheral blood lymphocytes (huPBL) were engrafted into mice with severe combined immune deficiency (SCID). The huPBL-SCID mice were then given various doses of diphtheria-tetanus toxoid (DT) vaccine and were examined for the presence of human DT-specific antibodies by ELISA. Surprisingly, treatment with anti-CD40 significantly lowered background DT responses versus untreated chimeras in unimmunized huPBL-SCID mice. However, after immunization, huPBL-SCID mice treated with anti-CD40 MoAb responded to a significantly greater extent in response to the vaccine compared with control huPBL-SCID mice, although total Ig levels were sometimes lower in anti-CD40-treated mice. The predominant Ig isotype induced after immunization was IgG. Thus, CD40 stimulation promotes human secondary IgG responses in huPBL-SCID mice. These data demonstrate that CD40 stimulation is capable of promoting antigen-specific human B-cell responses in vivo.

Interleukin 1 alpha increases serum leptin concentrations in humans.

Leptin, the protein product of the ob gene, regulates appetite and body weight in animals. Endotoxin and cytokines, induced by endotoxin, interleukin (IL) 1 and tumor necrosis factor, increase expression of leptin in mice and hamsters. We measured serum leptin concentrations in patients with cancer before and after administration of recombinant human IL-1 alpha. Fourteen patients received IL-1 alpha at one of three dose levels (0.03, 0.1, or 0.3 microgram/kg.day) for 5 days. Serum leptin concentrations increased in all but two patients within 24 h after the first dose. The increase in leptin was correlated directly with IL-1 alpha dose (P = 0.0030). Despite continued administration of IL-1 alpha, serum leptin concentrations returned to pretreatment levels by day 5 of therapy. An increase in serum leptin concentrations may be one mechanism by which anorexia is induced by IL-1 alpha. However, tachyphylaxis of the leptin response suggests that other mechanisms also are involved.

[Is SnorEx also ApneaEx? A study with a new intra-oral prosthesis as a form of therapy of obstructive sleep apnea syndrome]. / Ist SnorEx auch ApnoeEx? Eine Studie zu einer neuen intraoralen Prothese als Therapieform des obstruktiven Schlafapnoesyndroms.

UNLABELLED: In recent years different kinds of dental devices have been advocated for treating sleep apnoea. In this study we report on our results with a kind of prosthesis ("Snor-Ex", DEPITA, 29336 Nienhagen) designed to relieve upper airway obstruction in sleep in pulling forward the tongue by a truss pad positioned in the posterior area of the tongue. We performed the study to test the effectiveness of the device in reducing the number of obstructive events. PATIENTS: 23 patients with OSA (22 male, age: 53.7 +/- 8.6 years, Body mass index: 31.1 +/- 3.9 kg/m2, Apnoea index: 33.5 +/- 18.4, Respiratory disturbance index: 45.6 +/- 19.7, mean apnoea duration: 20.4 +/- 4.4 sec) were included. STUDY DESIGN: Before the study was started, polysomnography was performed and the OSA associated symptoms/claims were standardised with the help of visual analogue scales (VAS). The prosthesis were made by the dental laboratory. Between the 28th and 42nd day after beginning with the study the patients had to come to the hospital for control. The effect of the therapy was documented only by a further polysomnography in patients who could sleep for at least 2.5 hours with the prosthesis. The effects of the device on changing OSA-associated symptoms and snoring were reevaluated by the above mentioned VAS. During the control the patients were divided into non-responders (NR) and responders (R) according to the results. RESULTS: The NR prevail in the study with 75% (17/23). They are characterised by inacceptable loco-regional side effects of the prosthesis, missing improvement of the state of daytime wellbeing and constant obstructive events. Only 25% of the patients are R. They locally tolerated the prosthesis, which is the precondition for long-term therapy. The severity of OSA diminished. Snoring also diminished significantly. CONCLUSION: According to our results the insufficient acceptance and the low effectivity of the SnorEx-prosthesis preclude large-scale indication for OSA patients. The prosthesis should not be prescribed without contacting a sleep lab.

[Value of various intra- and extraoral therapeutic procedures for treatment of obstructive sleep apnea and snoring]. / Wertigkeit verschiedener intra- und extraoraler Therapieverfahren für die Behandlung der obstruktiven Schlafapnoe und des Schnarchens.

BACKGROUND: Recently intra- and extraoral devices are increasingly used in order to treat obstructive sleep apnea (OSA) and snoring. We examined the value of some devices according to the literature and our own results. PATIENTS AND METHODS: The mandibular advancing devices aim at increasing upper airway diameter. The active part of the tongue extending device (SnorEx) is a stamp connected to a piston which exerts pressure at the base of the tongue causing its forward displacement; we studied 23 patients. The principle of an optically stimulating system ("eye-cover", Snore-Stop) consists of a microphone and light diods which are integrated in the eye-cover. After detecting acoustic signals (for example snoring) optical stimuli are generated in front of the eyes, which are thought to induce arousals causing a change of body position and the reduction of the snoring and apneas; we measured 24 patients. The principle of the tongue-retainer (Snore-Master) is the fixation of the tongue in a ventral position, which is thought to enlarge the mesopharyngeal area; we studied 14 patients. The nose plaster (Breathe-Right) contains an elastic spine that pulls the alae nasi cranial. This manipulation is thought to increase the diameter of the nostril and reduce the airway resistance. We measured 30 patients with obstructive sleep apnea and 20 snoring subjects without obstructive sleep apnea. RESULTS: Regarding the mandibular advancing due to different appliance designs and study protocols variable success rates have been documented. In patients with mild to moderate obstructive sleep apnea a reduction of the sleep related breathing disorder could be shown. Non compliance (NC) to the tongue extending device was 75% (17/23). Non-compliance-patients were characterized by unacceptable local-side-effects of the prosthesis, lacking improvement of symptoms and of the respiratory disturbance index. Both tongue-retainer and -extensor are characterized by a high incidence of local side effects. Neither the eye-cover nor the nose plaster could improve the severity of obstructive sleep apnoe or snoring. In contrast to another study we could not show a significant effect of the tongue-retainer. CONCLUSIONS: Neither the nose plaster nor the optical stimulating device influenced the degree of obstructive sleep apnea and snoring. There are conflicting data regarding the tongue retainer. The high rate of non-compliant subjects and the low efficacy of the tongue extending prosthesis precludes large-scale use of this treatment modality in patients with obstructive sleep apnoe and snoring. In selected individuals suffering from a mild to moderate degree of obstructive sleep apnea with CPAP-inefficiency and -incompliance the mandibular advancing principle may be an therapeutic alternative to CPAP.

A new tongue advancement technique for sleep-disordered breathing: side effects and efficacy.

We examined the efficacy and the acceptance of an oral device (SnorEx) causing a forward displacement of the tongue for the treatment of sleep-disordered breathing (SDB). Twenty-three consecutive subjects with SDB were investigated. Noncompliance (NC) of use of the oral appliance was observed in 74% (17 of 23) of the subjects. NC patients were characterized by unacceptable local side effects of the prosthesis, lacking improvement of indicators of daytime well-being, and a missing reduction of the respiratory disturbance index (RDI). The device was tolerated without side effects in 26% (6 of 23) of the subjects. In these compliant (C) subjects the RDI, EDS, and snoring improved significantly (p < 0.05) compared with baseline values. After 6 mo using the device, five of the six C patients were still using it. We conclude that the high rate of noncompliance and the low efficacy of the SnorEx prosthesis preclude large-scale use of this treatment modality in patients with SDB and snoring since the local side effects are the principal cause of NC. No useful predictive parameter of treatment compliance or treatment success was found. Thus, this dental appliance should be prescribed only for selected patients failing other treatment modalities seen by an experienced sleep-disorders specialist.

Immunologic and hematopoietic effects of CD40 stimulation after syngeneic bone marrow transplantation in mice.

CD40 is a molecule present on multiple cell types including B lymphocyte lineage cells. CD40 has been shown to play an important role in B cell differentiation and activation in vitro, although little is known concerning the effects of CD40 stimulation in vivo. We therefore examined the effects of CD40 stimulation in mice using a syngeneic bone marrow transplantation (BMT) model in an effort to augment B cell recovery after high dose therapy with hematopoietic reconstitution. After the BMT, mice were treated with or without 2-6 microg of a soluble recombinant murine CD40 ligand (srmCD40L) given intraperitoneally twice a week. A significant increase in B cell progenitors (B220+/ surface IgM-) was observed in the bone marrow of mice receiving the srmCD40L. The treated recipients also demonstrated improved B-cell function with increases in total serum immunoglobulin and increased splenic mitogen responsiveness to LPS being noted. Additionally, srmCD40L treatment promoted secondary lymphoid organ repopulation, accelerating germinal center formation in the lymph nodes. Total B cell numbers in the periphery were not significantly affected even with continuous srmCD40L administration. Lymphocytes obtained from mice treated with the ligand also had increases in T cell mitogen and anti-CD3 mAb responsiveness and acquired the capability to produce IL-4. Surprisingly, treatment with srmCD40L also produced hematopoietic effects in mice, resulting in an increase of BM and splenic hematopoietic progenitor cells in the mice after BMT. Treatment with srmCD40L significantly increased granulocyte and platelet recovery in the peripheral blood. Incubation of BMC with srmCD40L in vitro also resulted in increased progenitor proliferation, demonstrating that the hematopoietic effects of the ligand may be direct. Thus, stimulation of CD40 by its ligand may be beneficial in accelerating both immune and hematopoietic recovery in the setting of bone marrow transplantation.

Chemokines in acute anterior uveitis.

PURPOSE: The aim of this study was to define the expression of chemoattractant cytokines (chemokines) in human aqueous humor, obtained from patients with idiopathic acute anterior uveitis (AU). The chemokines assayed included macrophage inflammatory proteins-1 alpha and -1 beta (MIP-1 alpha and -1 beta), monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), interferon-inducible protein-10 (IP-10), and regulated on activation, normal T-expressed and secreted (RANTES). METHODS: We studied fifteen patients (7 females) with idiopathic acute AU, at various stages of disease activity, and two control subjects undergoing elective cataract extraction. Aqueous humor was collected under aseptic conditions, after obtaining informed consent. Chemokine concentrations were measured using specific ELISA. Correlation was sought between chemokine concentrations and disease activity, evaluated by slit lamp biomicroscopy and graded using a standardized scale of disease severity. RESULTS: IL-8 was detected (35.9 +/- 13.6, mean +/- SE) in three of seven subjects in active, untreated stages of AU (clinical score 2-4), and it was undetectable in subjects sampled in the quiescent phase of the disease. IP-10 had a mean concentration of 40.6 ng/ml +/- 20.9 in the active group (N = 7), declining to 0.8 ng/ml +/- 0.3 in the samples from patients with inactive disease (N = 7, P = 0.001). Similarly, substantial expression of MCP-1 was noted, with a maximum concentration of 145 ng/ml, in acute (active) AU (N = 6), (26.7 +/- 19.7), falling to undetectable levels in those with inactive disease, and in control subjects (P = 0.001). MIP-1 beta (N = 7), (3.4 +/- 1.5, P = 0.001) and RANTES (N = 7, 8.8 +/- 4.2) levels were significantly increased in acute disease (P = 0.001) and related to the activity of the disease, although the concentrations were not as high as MCP-1, IP-10 and IL-8. IP-10, RANTES and MIP-1 beta were detected at low concentrations in the aqueous humor of the control subjects. CONCLUSIONS: This is the first study of chemokine concentrations in the aqueous humor of patients with acute anterior uveitis. The concentration of chemokines: IL-8, IP-10, MCP-1, RANTES and MIP-1 beta were significantly increased during the active stages of AU, and correlated with the clinical severity of the disease. These chemoattractant cytokines probably play a critical role in leucocyte recruitment in acute AU.

Induction of interleukin 1 receptor antagonist after interleukin 1 therapy in patients with cancer.

The interleukin 1 receptor antagonist (IL-1ra) is a naturally occurring molecule that shares homology with IL-1alpha and IL-1beta and binds competitively to IL-1 receptors. Serum concentrations of IL-1ra were measured by ELISA in patients enrolled in Phase I clinical trials of IL-1alpha and IL-1beta given by 15-min infusion. Pretreatment levels of IL-1ra were <1500 (mean, 453 +/- 57) pg/ml. IL-1ra levels were increased in some patients within 1 h of completing the IL-1 infusion. By 2 h after infusion, serum levels of IL-1ra had increased dramatically, and they remained stable 4 h after infusion. There was evidence that peak IL-1ra levels were IL-1 dose dependent. Seven patients treated with IL-1alpha had IL-1ra levels that exceeded 1 microgram/ml. In contrast, serum levels of IL-1 declined rapidly and were undetectable 1 h after completing IL-1 infusion in most patients receiving <1.0 microgram/kg. IL-1ra levels remained slightly elevated over pretreatment values in serum obtained 18-24 h after IL-1 infusion, but there was no evidence for progressive accumulation over repeated days of therapy. A similar pattern of IL-1ra elevation was observed after the last IL-1 infusion on day 6. This study shows that cancer patients produce 2 to >6 log incremental increases in IL-1ra rapidly following treatment with IL-1, a response that has implications for the design of future clinical trials with IL-1 and with agents thought to induce IL-1 production.

Antibodies to CD40 prevent Epstein-Barr virus-mediated human B-cell lymphomagenesis in severe combined immune deficient mice given human peripheral blood lymphocytes.

CD40 is expressed on both normal and neoplastic B lymphocytes. Signal transduction through CD40 in vitro has been shown to exert stimulatory effects on normal B cells and inhibitory effects on Epstein-Barr virus (EBV)-induced B-cell lymphoma lines and some other cell lines derived from patients with aggressive histology lymphoma. The transfer of normal human peripheral blood lymphocytes (huPBL) from EBV-seropositive donors into severe combined immune deficient (SCID) mice has been previously shown to result in the generation of human B-cell lymphomas. These tumors are similar to the highly aggressive EBV-induced lymphomas that can arise clinically after transplantation or in the setting of immunodeficiency. Treatment of huPBL-SCID chimeric mice with anti-CD40 or anti-CD20 monoclonal antibodies (MoAb) significantly delayed the development of EBV-induced B-cell lymphoma. However, the effects of the two MoAb were mechanistically distinct. Anti-CD40 treatment prevented lymphoma generation, while still allowing for functional human B-cell engraftment in the huPBL-SCID mice compared with mice receiving no treatment, all of which succumbed to lymphoma. By contrast, treatment with anti-CD20 significantly inhibited total human B-cell engraftment in the SCID recipients, which accounted for the absence of lymphomas. In vitro assays examining the transformation of human B cells by EBV also indicated that anti-CD40 could directly inhibit EBV-transformation, whereas anti-CD20 antibodies had no effect. Thus, anti-CD40 exerts selective effects to allow for the engraftment of normal human B cells and prevent the emergence of EBV lymphomas. Stimulation of CD40 by antibodies or its physiologic ligand may, therefore, be of significant clinical use in the prevention of EBV-induced B lymphomas that may arise when EBV-seropositive individuals receive immunosuppressive regimens after transplantation or in immune deficiency states, such as acquired immune deficiency syndrome.

Continuous infusion of the anti-CD22 immunotoxin IgG-RFB4-SMPT-dgA in patients with B-cell lymphoma: a phase I study.

IgG-RFB4-SMPT-dgA consists of deglycosylated ricin A chain (dgA) coupled to the monoclonal antihuman CD22 antibody, RFB4. This study determined the maximally tolerated dose (MTD) of this immunotoxin (IT) administered as a continuous 8-day infusion to 18 patients with B-cell lymphoma (30% CD22+ tumor cells) over 8 days. The MTD was 19.2 mg/m2/192 h (maximum toxicity grade 1), with vascular leak syndrome (VLS) as dose-limiting toxicity (DLT) at 28.8 mg/m2/192 h (grades 3 through 5 in 7 of 11 patients). Predictors of severe VLS included serum IT concentrations greater than 1,000 ng/mL and the absence of circulating tumor cells. Decreased urine sodium excreted in 24 hours provided evidence for mild VLS without notable changes in serum albumin. Four partial responses, 3 minor responses, 6 stable disease, and 3 progression of disease were observed. The mean maximal serum concentration (Cmax) in initial courses at the MTD (19.2 mg/m2) was 443 +/- 144 ng/mL (n = 3; range, 326 to 604). At 28.8 mg/m2/192 h, the Cmax was highly variable (n = 11; mean, 1,102 +/- 702; range, 9.6 to 2,032 ng/mL). Human antimouse or antiricin antibodies developed in 6 of 16 (37.5%) patients after one course of IT. However, 10 eligible patients received multiple courses of IT. Changes in serum cytokines and cytokine receptors did not correlate with toxicity but decreased soluble interleukin-2 receptor concentrations correlated with clinical response. Comparison to a prior study with the same IT administered by intermittent bolus infusions (Amlot et al, Blood 82:2624, 1993) suggests similar clinical response, toxicity, and immunogenicity.

Intraperitoneal lymphokine-activated killer cell/interleukin-2 therapy in patients with intra-abdominal cancer: immunologic considerations.

Lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) were administered by the ip route to patients with intra-abdominal malignancies. Pharmacokinetic studies of IL-2 revealed 10- to 100-fold higher concentrations of IL-2 in peritoneal fluid versus serum. Ip levels of IL-2 were maintained well above those required to generate and maintain LAK cells in vitro. LAK cell activity was detectable in the peritoneal fluid for the duration of each treatment cycle and did not disappear until IL-2 was discontinued. Detection of interferon-gamma (IFN-gamma) in the peritoneal fluid of all patients was consistent with production in situ by activated lymphocytes. In some patients, low but detectable levels of IFN-gamma were also found in the serum. In vivo activation of monocytes in the peritoneal fluid as measured by in vitro production of hydrogen peroxide was documented in the majority of patients. Neither interleukin-1 nor tumor necrosis factor-alpha was detected in the peritoneal fluid. We found no correlation between the presence or levels of IL-2, IFN-gamma, or LAK cell lytic activity in peritoneal fluid or serum and response or nonresponse to therapy.

The generation of monoclonal anti-idiotype antibodies to human B cell-derived leukemias and lymphomas.

We developed murine anti-idiotype monoclonal antibodies for each of four patients with B cell-derived leukemias and lymphomas. Idiotypic immunoglobulin was isolated from mouse X human tumor-cell hybridomas or from patients' serum and was used to immunize mice for the development of murine anti-idiotype monoclonal antibodies. Each patient's anti-idiotype antibodies demonstrated reactivity restricted to the immunizing immunoglobulin, thereby limiting their therapeutic utility to a single individual. In addition, we isolated isotype switch variants of hybridomas producing monoclonal anti-idiotypic antibody. The restricted specificity of these antibodies was found to be of value for the analysis of the extent of malignant B cell infiltration in a variety of tissues from several patients. Large populations of idiotype-bearing cells were detectable in biopsy specimens from patients K.T. and L.H. In contrast, although bone marrow specimens from patient G.D. were apparently devoid of morphologically abnormal cells, a small, highly fluorescent population of cells was demonstrable underscoring the potential utility of these antibodies for posttreatment evaluation as well as for therapy. In a fourth patient, H.M., anti-idiotype antibodies developed against the circulating macroglobulin isolated from his plasma failed to react with either his circulating or bone marrow hairy cell leukemia cells. However, examination of an enlarged inguinal lymph node revealed the presence of a large number of idiotype-bearing cells. Thus, the presence of two distinct malignant B cell clones were discovered in this individual through the use of anti-idiotype monoclonal antibodies. Anti-idiotype antibodies, therefore, represent a highly specific tool for the evaluation and potential therapy of B cell malignancies in individual patients.

The generation of stable human T-cell hybridomas which constitutively produce interleukin-2 and chemotactic factor.

We report the successful generation of human T-cell hybridomas that constitutively secrete lymphokines. An acute lymphoblastic leukemia T-cell line, CCRF-H-SB2, free of reverse transcriptase and mycoplasma, was sensitized to hypoxanthine, aminopterin, and thymidine (HAT) by selecting out a mutant deficient in hypoxanthine guanine phosphoribosyl transferase (HGPRT) in 8-azaguanine. Peripheral blood T lymphocytes from normal donors were incubated in vitro with 10 micrograms/ml of concanavalin A for 48 h and subsequently fused with the CCRF-H-SB2 HAT-sensitive cell line. Following 5 weeks in culture, 38 of 440 wells (8.6%) demonstrated hybridoma growth. Supernatants of these cultures were screened for interleukin-2 (IL-2), chemotactic factor, interferon, migration inhibition factor, and macrophage-activating factor activities. Twelve (of 38) hybrids exhibited IL-2 activity, and eight of these were successfully cloned. The highest secreting clone was demonstrated to have mRNA to IL-2 while the parent CCRF-H-SB2 had no detectable mRNA to IL-2. Three hybrid cultures produced chemotactic factor; one was successfully cloned and grown in serum-free medium, where it continued to constitutively produce chemotactic factor as well as IL-2 activity. The chemotactic factor was determined to have the same molecular weight (12,500 daltons) as leukocyte-derived chemotactic factor. Constitutive IL-2 production remained stable for over 12 months. None of the hybridomas tested produced detectable levels of gamma interferon, migration inhibition factor, or macrophage activation factor. Because these T-cell hybridomas produce lymphokines constitutively and this phenotype is stable, they can be an important source of highly purified human lymphokines for clinical and laboratory investigations.