Inter-patient heterogeneity in the hepatic ischemia-reperfusion injury transcriptome: Implications for research and diagnostics

Cellular responses induced by surgical procedure or ischemia-reperfusion injury (IRI) may severely alter transcriptome profiles and complicate molecular diagnostics. To investigate this effect, we characterized such pre-analytical effects in 143 non-malignant liver samples obtained from 30 patients at different time points of ischemia during surgery from two individual cohorts treated either with the Pringle manoeuvre or total vascular exclusion. Transcriptomics profiles were analyzed by Affymetrix microarrays and expression of selected mRNAs was validated by RT-PCR. We found 179 mutually deregulated genes which point to elevated cytokine signaling with NFκB as a dominant pathway in ischemia responses. In contrast to ischemia, reperfusion induced pro-apoptotic and pro-inflammatory cascades involving TNF, NFκB and MAPK pathways. FOS and JUN were down-regulated in steatosis compared to their up-regulation in normal livers. Surprisingly, molecular signatures of underlying primary and secondary cancers were present in non-tumor tissue. The reported inter-patient variability might reflect differences in individual stress responses and impact of underlying disease conditions. Furthermore, we provide a set of 230 pre-analytically highly robust genes identified from histologically normal livers (<2% covariation across both cohorts) that might serve as reference genes and could be particularly suited for future diagnostic applications.

[Sterile puncture of large joints]

OBJECTIVE

Puncture of large joints is performed for diagnostic purposes on the one hand and for the treatment of joint pathologies on the other. Puncture can be used for rapid pain relief by relieving effusions or intra-articular hematomas. The obtained puncture specimen allows immediate visual assessment and subsequent microscopic-cytological and microbiological evaluation in the laboratory.

INDICATIONS

The indication for puncture of a large joint is for diagnosis and/or therapy of inflammatory, traumatic or postoperative joint problems. Diagnostic punctures are used to obtain punctate, to differentiate the location of pain or (rarely) to apply contrast medium for magnetic resonance arthrography. Therapeutic punctures allow the injection of drugs or platelet-rich plasma (PRP) as well as the relief or drainage of effusions.

CONTRAINDICATIONS

If there are inflammatory skin alterations-especially purulent inflammation-joint punctures through these lesions are absolutely contraindicated. Special attention is necessary if the patients are on anticoagulants.

SURGICAL TECHNIQUE

Absolute sterile handling is mandatory. Unnecessary pain can be avoided by a sterile skin wheal of local anesthesia, safe puncture points, and careful handling of the cannulas.

POSTOPERATIVE MANAGEMENT

Joint aspiration material has to be handled according to the local, intrahospital rules in a timely manner. Puncture sites are covered with sterile dressings, and if intra-articular medication is administered, the joints have to be passively moved through the range of motion to distribute the medication. Thereafter, compression therapy from distally to proximally while also covering the puncture site avoids recurrence of swelling or hematoma.

FACTS

If sterile conditions are guaranteed, infections rarely occur (0.04-0.08%, 4-8/10,000 cases). The risk of false-positive detection of microorganisms is extremely low.

Increasing the throughput of label-free cell assays to study the activation of G-protein-coupled receptors by using a serial agonist exposure protocol

Label-free, holistic assays, monitoring, for example, the impedance of cells on electrodes, are gaining increasing popularity in the evaluation of G-protein-coupled receptor (GPCR) ligands. It is the strength of these approaches to provide the integrated cellular response non-invasively, highly automated and with a device-dependent time resolution down to several milliseconds. With an increasing number of samples to be studied in parallel, the available time resolution is, however, reduced and the cost for the disposable sensor arrays may become limiting. Inspired by protocols from organ pharmacology, we investigated a simple serial agonist addition assay that circumvents these limitations in impedance-based cellular assays. Using a serial addition of increasing concentrations of a GPCR agonist while continuously monitoring the sample's impedance, we were able to establish a full concentration-response curve for the endogenous agonist histamine on a single layer of U-373 MG cells endogenously expressing the histamine 1 receptor (H1R). This approach is validated with respect to conventional, parallel agonist addition protocols and studies using H1R antagonists such as mepyramine. Applicability of the serial agonist addition assay was shown for other GPCRs known for their signaling via one of the canonical G-protein pathways, Gq, Gi/0 or Gs as well. The serial agonist addition protocol has the potential to further strengthen the output of label-free analysis of GPCR activation.

Initial Characterization of Transgenic Mice Overexpressing Human Histamine H2 Receptors

In an integrative approach, we studied the role of histamine H₂ receptors in the mouse heart. We noted that histamine, added cumulatively to the organ bath, failed to affect the force of contraction in left atrial preparations and did not change spontaneous heart rate in right atrial preparations from wild-type mice. By contrast, in the same preparations from mice that overexpressed the human H₂ receptor in a cardiac-specific way, histamine exerted concentration- and time-dependent positive inotropic and positive chronotropic effects. Messenger RNA of the human H₂ receptor was only detected in transgenic mice. Likewise, immunohistology and autoradiography only gave signals in transgenic but not in wild-type cardiac preparations. Similarly, a positive inotropic and positive chronotropic effect was observed with histamine in echocardiography of living transgenic mice and isolated perfused hearts (Langendorff preparation). Phosphorylation of phospholamban was increased in atrial and ventricular preparations from transgenic mice, but not in wild-type animals. The effects of histamine were mimicked by dimaprit and amthamine and antagonized by cimetidine. In summary, we generated a new model to study the physiologic and pathophysiologic cardiac role of the human H₂ receptor.

The negative effect of unloading exceeds the bone-sparing effect of alkaline supplementation: a bed rest study

Potassium bicarbonate was administrated to an already alkaline diet in seven male subjects during a 21-day bed rest study and was able to decrease bed rest induced increased calcium excretion but failed to prevent bed rest-induced bone resorption.

INTRODUCTION

Supplementation with alkali salts appears to positively influence calcium and bone metabolism and, thus, could be a countermeasure for population groups with an increased risk for bone loss. However, the extent to which alkalization counteracts acid-induced bone resorption or whether it merely has a calcium and bone maintenance effect is still not completely understood. In the present study, we hypothesized that additional alkalization to an already alkaline diet can further counteract bed rest-induced bone loss.

METHODS

Seven healthy male subjects completed two parts of a crossover designed 21-day bed rest study: bed rest only (control) and bed rest supplemented with 90 mmol potassium bicarbonate (KHCO₃) daily.

RESULTS

KHCO₃supplementation during bed rest resulted in a more alkaline status compared to the control intervention, demonstrated by the increase in pH and buffer capacity level (pH p = 0.023, HCO₃p = 0.02, ABE p = 0.03). Urinary calcium excretion was decreased during KHCO₃ supplementation (control 6.05 ± 2.74 mmol/24 h; KHCO₃ 4.87 ± 2.21 mmol/24 h, p = 0.03); whereas, bone formation was not affected by additional alkalization (bAP p = 0.58; PINP p = 0.60). Bone resorption marker UCTX tended to be lower during alkaline supplementation (UCTX p = 0.16).

CONCLUSIONS

The more alkaline acid-base status, achieved by KHCO₃ supplementation, reduced renal calcium excretion during bed rest, but was not able to prevent immobilization-induced bone resorption. However, advantages of alkaline salts on bone metabolism may occur under acidic metabolic conditions or with respect to the positive effect of reduced calcium excretion within a longer time frame.

TRIAL REGISTRATION

Trial number: NCT01509456.

Label-free versus conventional cellular assays: Functional investigations on the human histamine H1 receptor

A set of histamine H₁ receptor (H₁R) agonists and antagonists was characterized in functional assays, using dynamic mass redistribution (DMR), electric cell-substrate impedance sensing (ECIS) and various signaling pathway specific readouts (Fura-2 and aequorin calcium assays, arrestin recruitment (luciferase fragment complementation) assay, luciferase gene reporter assay). Data were gained from genetically engineered HEK293T cells and compared with reference data from GTPase assays and radioligand binding. Histamine and the other H₁R agonists gave different assay-related pEC₅₀ values, however, the order of potency was maintained. In the luciferase fragment complementation assay, the H₁R preferred β-arrestin2 over β-arrestin1. The calcium and the impedimetric assay depended on G_q coupling of the H₁R, as demonstrated by complete inhibition of the histamine-induced signals in the presence of the G_q inhibitor FR900359 (UBO-QIC). Whereas partial inhibition by FR900359 was observed in DMR and the gene reporter assay, pertussis toxin substantially decreased the response in DMR, but increased the luciferase signal, reflecting the contribution of both, G_q and G_i, to signaling in these assays. For antagonists, the results from DMR were essentially compatible with those from conventional readouts, whereas the impedance-based data revealed a trend towards higher pK_b values. ECIS and calcium assays apparently only reflect G_q signaling, whereas DMR and gene reporter assays appear to integrate both, G_q and G_i mediated signaling. The results confirm the value of the label-free methods, DMR and ECIS, for the characterization of H₁R ligands. Both noninvasive techniques are complementary to each other, but cannot fully replace reductionist signaling pathway focused assays.

Like or Dislike? Impact of Facebook on Ewing Sarcoma Treatment

Background

An increasing number of patients are raising their voices in online forums to exchange health-related information. Facebook is the leading social media platform with more than 1 billion international daily users recorded in the summer of 2015. Facebook has a dynamic audience and is utilized in a number of ways, discussing medical issues being one of them. Ewing sarcoma mainly affects teenagers and young adults. Additionally, many individuals within this age group are regular users of Facebook. However, little is known about the impact of this modern way of communication via Web-based platforms on patients with Ewing sarcoma and their social environment.

Objective

The aim of this study was to analyze and compare Ewing sarcoma patients’ and relatives’ behavior on Facebook to draw conclusions regarding the impact of Facebook on Ewing sarcoma treatment.

Methods

We examined a Facebook group named “Ewing Sarcoma Awareness” that is used to exchange information for both patients and relatives regarding Ewing sarcoma. A self-designed questionnaire was used to compare patients’ and relatives’ answers. Additionally, we analyzed all processes (posts, likes, threads, links) in the group for 6 consecutive months. A total of 65 members of the Facebook group (26 patients, 39 relatives) out of 2227 international group members participated in our study.

Results

More than 70% (46/65) of all participants reported that they use the group Ewing Sarcoma Awareness as a source of information about Ewing sarcoma. Of the participants, 89% (58/65) agreed on our scale from a little to a lot that being in contact with other affected people through the group makes it easier to handle the diagnosis. In this study, 20% (13/65) of all participants reported that the group affected their choice of treatment and 15% (10/65) of participants were influenced in the selection of their specialist. Regarding the recommendation of the Facebook group toward other people, significant differences (P=.003) were found comparing patients’ and relatives’ results. During the last 6 months most activities in the group concerned sharing destiny and handling the diagnosis.

Conclusions

The Facebook group Ewing Sarcoma Awareness has a relevant impact on group members regarding their choice of treatment. Moreover, participants turn toward the group to receive mental and emotional support in everyday life. Statements made within the group are in part questionable from a medical point of view and the impact made by these statements on patients’ care requires further evaluation.

[The Effect of Intraoperative Screw Monitoring (Root Monitoring) with the INS-1 System (NUVASIVE) on the Radiological Outcome of Dorsal Instrumentation of the Lumbar Spine]

INTRODUCTION

Transpedicular screw fixation of spinal segments has been described for a variety of surgical indications and is a key element in spinal surgery. The aim of transpedicular screw fixation is to achieve maximal stability. Screw malposition should be obviated to avoid neurological complications. There are published methods of applying evoked EMG to control screw position in relation to neural structures. These studies demonstrated that an intact bony pedicle wall acts as an electrical isolator between the screw and spinal nerve root. The aim of our study was to evaluate the impact of intraoperative pedicle screw monitoring on screw positioning.

MATERIAL AND METHODS

We enrolled 22 patients in this prospective randomised study, who underwent spinal instrumentation after being split into two equal groups. In the first group, dorsal instrumentation was supplemented with intraoperative nerve root monitoring using the INS-1-System (NuVasive, San Diego USA). In the second group, screws were inserted without additional pedicle monitoring. All patients underwent monosegmental instrumentation with "free hand implanted" pedicle screws. 44 screws were inserted in each group. The screw position was evaluated postoperatively using CT scans. The position of the screws in relation to the pedicle was measured in three different planes: sagittal, axial and coronal. The accuracy of the screw position was described using the Berlemann classification system. Screw position is classified in three groups: type 1 correct screw position, type 2 encroachment on the inner cortical wall, type 3 pedicle cortical perforation. Screw angulation and secondary operative criteria were also evaluated.

RESULTS

The use of neuromonitoring did not influence the distance between the centre of the screws and the pedicle wall. Distances only depended on the implantation side (right and left) and the height of implantation (caudal or cranial screw). Because of the low number of cases, no conclusion could be reached about the influence of root monitoring on the correct positioning of the screws. There was at least a non-significant trend towards more frequent perforation of the pedicle in the monitor group. In the present study, we showed that root monitoring had a significant effect on the scattering of transversal angles. These were increased compared to the control group. Otherwise, the implantation angle was not shown to depend on the use of neuromonitoring. Neuromonitoring did not influence blood loss or operative time.

DISCUSSION

The data did not permit any conclusion as to whether this technique can minimise the frequency of pedicle screw malposition. The four coronal plane distances did not depend on the use of neuromonitoring. The inclination angle was also unaffected by neuromonitoring. The only parameter for which we found any effect was the transverse angle. The mean values were similar in both groups, but the variances were not equal. The effect of monitoring on the only parameter which could not be evaluated by fluoroscopy is thus rather unfavourable.

Molecular determinants for the high constitutive activity of the human histamine H4 receptor: functional studies on orthologues and mutants

BACKGROUND AND PURPOSE

Some histamine H4 receptor ligands act as inverse agonists at the human H4 receptor (hH4 R), a receptor with exceptionally high constitutive activity, but as neutral antagonists or partial agonists at the constitutively inactive mouse H4 receptor (mH4 R) and rat H4 receptor (rH4 R). To study molecular determinants of constitutive activity, H4 receptor reciprocal mutants were constructed: single mutants: hH4 R-F169V, mH4 R-V171F, hH4 R-S179A, hH4 R-S179M; double mutants: hH4 R-F169V+S179A, hH4 R-F169V+S179M and mH4 R-V171F+M181S.

EXPERIMENTAL APPROACH

Site-directed mutagenesis with pVL1392 plasmids containing hH4 or mH4 receptors were performed. Wild-type or mutant receptors were co-expressed with Gαi2 and Gβ1 γ2 in Sf9 cells. Membranes were studied in saturation and competition binding assays ([(3) H]-histamine), and in functional [(35) S]-GTPγS assays with inverse, partial and full agonists of the hH4 receptor.

KEY RESULTS

Constitutive activity decreased from the hH4 receptor via the hH4 R-F169V mutant to the hH4 R-F169V+S179A and hH4 R-F169V+S179M double mutants. F169 alone or in concert with S179 plays a major role in stabilizing a ligand-free active state of the hH4 receptor. Partial inverse hH4 receptor agonists like JNJ7777120 behaved as neutral antagonists or partial agonists at species orthologues with lower or no constitutive activity. Some partial and full hH4 receptor agonists showed decreased maximal effects and potencies at hH4 R-F169V and double mutants. However, the mutation of S179 in the hH4 receptor to M as in mH4 receptor or A as in rH4 receptor did not significantly reduce constitutive activity.

CONCLUSIONS AND IMPLICATIONS

F169 and S179 are key amino acids for the high constitutive activity of hH4 receptors and may also be of relevance for other constitutively active GPCRs.

LINKED ARTICLES

This article is part of a themed issue on Histamine Pharmacology Update published in volume 170 issue 1. To view the other articles in this issue visit http://onlinelibrary.wiley.com/doi/10.1111/bph.2013.170.issue-1/issuetoc.

Prosthetic joint infection following total hip replacement: results of one-stage versus two-stage exchange

PURPOSE

Prosthetic hip joint infection remains a challenging socio-economic problem. Curative treatment is usually a one- or two-stage revision surgery, but neither of these options has yet emerged as the treatment of choice. The aim of this study was to evaluate which of these methods produced superior outcomes.

METHODS

A retrospective study was performed including 92 patients with deep infections after implantation of primary total hip arthroplasty (THA) who had undergone either one-stage or two-stage revision surgery at a single centre. Infections were classified according to McPherson and we evaluated the rate of persisting infection or reinfection after surgical intervention.

RESULTS

The two-stage revision surgery revealed superior outcomes for the analysed infection categories compared to the one-stage procedure except for the least serious category of infections (i.e. McPherson Stage I/A/1, early postoperative infection, no systemic comorbidities, local status uncompromised). Eradication of prosthetic infection was achieved in 94.5 % (n = 52) within the group of two-stage exchange, and 56.8 % (n = 21) of patients treated with a one-stage procedure. Outcome of patients following a one-stage or a two-stage exchange was overall significantly different with p < 0.001. Further deviations between the described two procedures were noted in the subgroups following the classification described by McPherson.

CONCLUSIONS

Our results indicate superiority of two-stage revision surgery in case of serious infections. The authors believe that decisions on the surgical approach for the treatment of deep prosthesis infections should be made on the basis of standardized staging systems.

Efficacy of BCNU and paclitaxel loaded subcutaneous implants in the interstitial chemotherapy of U-87 MG human glioblastoma xenografts

Nude mice were challenged with human U-87 MG glioblastoma tumors to assess the efficacy of different cytostatics and different application protocols. While the intraperitoneal application of BCNU solutions (3 times 20 mg BCNU/kg) had no effect on tumor growth, the application of polymer matrices made of a physical mixture of poly(1,3-bis[carboxyphenoxpropane]-co-sebacic acid) 20:80 with poly(D,L-lactic-co-glycolic acid) loaded with 0.25 mg BCNU, slowed down the growth of tumors significantly. When the animals were treated with implants carrying 0.25 mg BCNU they responded to the treatment whether the tumor had been inoculated recently (9 days ago) or whether it was fully established (after 20 days). After its sensitivity was proven, the xenograft model was used to further investigate the efficacy of anticancer drugs and some treatment regimens using polymer implants. Thus the tumor model allowed to discriminate between the efficacy of different doses of BCNU. Only implants loaded with 0.75 or 1 mg of BCNU led to a substantial suppression of tumor growth over approximately 2 months. While BCNU was only able to suppress the growth of the tumor, the combination of BCNU with paclitaxel led to a complete remission in some animals. These preliminary results suggest that combinations of cytostatics might improve local chemotherapy of malignant glioma substantially. Based on our data it will be worthwhile to investigate implants that release drugs such as BCNU and paclitaxel closer. Amongst other factors we will try to elucidate the effect of repetitive doses of drugs using programmable implants.

Does [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine] dichloroplatinum(II) act as an immune response modifier? IV. Inhibition of the proliferation-increasing effect of progressively growing MXT-M-3,2 breast cancer on phagocytes by the title compound

In female B6D2F1 mice bearing an MXT-M-3,2 breast cancer graft the level of the phagocytic cells (e.g. of granulocytes and macrophages in the spleen and of granulocytes and monocytes in the blood) is significantly elevated. The positive correlation between the number of the phagocytic cells and the weight of the tumor indicates that the MXT-M-3,2 breast cancer promotes myelopoiesis, presumably by secretion of hematopoietic growth factors like GM-CSF. This process can be described for each phagocyte type by a regression equation. Due to its hormonal potency [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine] dichloroplatinum(II) (meso-1-PtCl2) can reduce the excessive numbers of the granulocytes and macrophages, which seem to be responsible for the progressive growth of the MXT-M-3,2 breast cancer. This process leads to an interruption of the vicious circle of mutual growth stimulation of breast cancer cells and these phagocytes. The target of meso-1-PtCl2 is the estrogen receptor (ER) of the breast cancer cell. The interaction between meso-1-PtCl2 and the ER presumably results in a diminished secretion of hematopoietic growth factors and hence in a decline of the number of phagocytic cells. Meso-1-PtCl2 does not inhibit the proliferation of tumor cells by direct interaction with their DNA, as is described for platinum complexes like cDDP. In its mode of action the equipotent, breast cancer inhibiting drug cDDP differs from meso-1-PtCl2. This is obvious from the fact that in cDDP--but not in meso-1-PtCl2-treated, tumor bearing mice the number of granulocytes and macrophages does not markedly deviate from that in untreated control mice with tumors of the same weight. The drug cDDP probably does not interfere with the mechanism of the secretion of hematopoietic growth factors. The reduction of the number of tumor cells by cDDP leads to a decline of the number of phagocytic cells in accordance with the respective regression equations. In contrast to meso-1-PtCl2 and cDDP, ovariectomy causes elevated phagocyte numbers, probably due to the strongly reduced estrogen level. The studies described in this publication indicate that the anti-breast cancer activity of meso-1-PtCl2 is caused by a decimation of phagocytes and with this by an abolition of the tumor promoting effect. Furthermore, a restoration of the natural immunosurveillance seems to be of importance.

The poliovirus receptor CD155 mediates cell-to-matrix contacts by specifically binding to vitronectin

The human receptor for poliovirus (CD155) is an immunoglobulin-like molecule with unknown normal function(s). Here we provide evidence that CD155 binds specifically to vitronectin with a dissociation constant (K(d)) of 72 nM as determined by surface plasmon resonance. Based on sequence homology to the CD155 gene, three poliovirus receptor-related genes (PRR1, PRR2, and PRR3) were cloned recently. PRR proteins were reported by others to mediate homophilic cell adhesion. Neither PRR1 nor PRR2 binds poliovirus and it is assumed that their physiological functions differ from that of CD155. Indeed, mPRR2 was found to bind to vitronectin only weakly, while its self-adhesion activity is characterized by a K(d) of 310 nM. Moreover, there is no evidence for CD155 self-adhesion. Both CD155 and vitronectin colocalize to follicular dendritic cells and B cells inside the germinal centers of secondary lymphoid tissue (tonsils)-an observation suggesting that the CD155/vitronectin interaction is required for the establishment of a proper immune response in this particular context.

Programmable biodegradable implants

Pulsatile release implants were developed that release substances up to 58 days post implantation. With a cylindrical size of 2 mm diameter and 1.8 mm height the matrices can carry as much as 1 mg of drug and allow even for intracranial implantation into a rodent model. The matrices are made of materials that have been used for parenteral applications in humans before such as surface eroding polyanhydrides and bulk eroding poly(D,L-lactic acid) or poly(D,L-lactic acid-co-glycolic acid). The onset of drug release is controlled by the degradation of bulk eroding polymers which are known to exhibit a certain stability over a defined period of time and which start eroding after they reach a critical degree of degradation. The time of drug release onset was found to depend on the molecular weight and the chemical state of the carboxylic acid end of the polymer chain. For testing the onset of release in vivo a nude mouse model was developed where the release of Evan's blue could be observed visually after subcutaneous application. By combining individual matrices with different release onset, a therapeutic system can be composed that releases drugs after implantation at predetermined time points in a preprogrammed way. Potential applications for such matrices is vaccination and local tumor therapy.

Chiral separation of pheniramine-like 3-phenyl-3-heteroarylpropylamines by CE and HPLC methods

Analytical CE and HPLC methods were developed for the chiral separation of halogen-substituted 3-phenyl-3-(2-pyridyl)propylamines 1-4 (1: 3-(4-fluorophenyl) approximately, 2: 3-(3,4-difluorophenyl) approximately, 3: 3-(4-chlorophenyl) approximately, 4: 3-(3,4-dichlorophenyl) approximately ), 3-(4-fluorophenyl)-3-(2-thiazolyl)propylamine (5), and 3-(4-fluorophenyl)-3-(1-benzylimidazol-2-yl)propylamine (6), which are building blocks for the preparation of very potent arpromidine-type histamine H(2) receptor agonists. All amines were enantioseparated by CE with resolutions of at least 1.8 using alpha-, beta-, or gamma-cyclodextrin (CD) as chiral selectors. With heparin as buffer additive for CE the optical antipodes of 1-4 and 6 were separated with resolutions > or = 1.8. On RP-18 columns the separation of the (+)-(S)-acetylmandelic acid amides of racemic 2 (R = 0.9, alpha = 1.07) and the thioureas prepared by addition of 6 to 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (R = 2.0, alpha = 1.20) was successful, whereas the diastereomeric ureas prepared from 3 and (+)-(S)-1-(1-naphthyl)ethyl isocyanate could not be resolved. Separation of the diastereomeric isoindoles prepared from 1-5, o-phthaldialdehyde and 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranoside was achieved on a RP-18 phase (R > or = 0.4, a > or = 1.02). Direct separation of the enantiomers of 3 and 4 was achieved on a Cyclobond I column (R > or = 0.9, alpha > or = 1.07). alpha- and beta-CD were also useful as mobile phase additives for HPLC (3 and 4: RP-18 column, beta-CD, R > or = 0.4, alpha > or = 1.03; 3: RP-18 column, alpha-CD: R = 0.5, alpha = 1.04).

1-(2,6-dichloro-4-hydroxyphenyl)-2-phenylethanes--new biological response modifiers for the therapy of breast cancer. Synthesis and evaluation of estrogenic/antiestrogenic properties

[meso-1,2-Bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]platinum(II) complexes (meso-1-PtLL'; L,L' = Cl or L = H2O and L' = OSO3) are highly effective towards hormone-sensitive, rodent breast cancers due to their significant estrogenic potencies. Their antitumor activities are caused by modification of the immune response. The pharmacophor of these compounds, the 1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethane (23H), was used as the lead structure in a structure-activity study with the goal of finding new biological response modifiers for the therapy of breast cancer. As intermediates for the synthesis of the 23H derivatives, the CH3O-substituted stilbenes 12E/12Z-16E/16Z were prepared by reaction of the related benzyltriphenylphosphonium halides with 2,6-dichloro-4-methoxybenzaldehyde by the method of Wittig/Campbell and Donald, respectively. Separation of the E/Z-mixtures was performed by fractional crystallization and/or column chromatography. The E-1,2-bis(2,6-dichloro-4-methoxyphenyl)ethene (17E) was obtained by reductive coupling of 2,6-dichloro-4-methoxybenzaldehyde with TiCl4/Zn according to the method of Mukaiyama. Illumination of the solution of 17E in benzene with UV light resulted in an E/Z-isomerization. Compound 17Z could be isolated from this mixture. The CH3O-substituted stilbenes were transformed into their 1,2-diphenylethanes (12H-17H) by catalytic hydrogenation of the C1=C2 double bond. Ether cleavage of the compounds was performed with BBr3. In the estrogen receptor binding assay all OH-substituted 1,2-diphenylethanes showed affinity to the estrogen receptor, which was about two orders of magnitude lower than that of 17 beta-estradiol. In the uterus weight test on the immature mouse 1,2-diphenylethanes with 4-substituted OH groups proved to be "true" estrogens (19H: 2-F/4-OH; 20H: 2-Cl/4-OH; 23H: 2,6-Cl2/4-OH), while those with a 3-substituted OH group in the 2-phenyl ring showed the properties of a "partial" estrogen (18H: 3-OH) or of an "impeded" estrogen (21H: 2-Cl/3-OH; 22H: 2-Cl/5-OH). The latter also showed significant additional antiestrogenic activity. The related E-stilbenes mostly exhibit similar hormonal activities. As a rule, the replacement of the OH groups by the CH3O groups and the change from the E- to the Z-configuration led to a reduction of the estrogenic potencies. Several of the 1-(2,6-dichloro-4-methoxyphenyl)-2-phenylethenes (12E: 3-OCH3; 12Z: 3-OCH3; 15E: 2-Cl/3-OCH3; 15Z: 2-Cl/3-OCH3; 16E: 2-Cl/5-OCH3) produced antiestrogenic effects in the uterus weight test. It is supposed that those new 1-(2,6-dichloro-4-hydroxyphenyl)-2-phenylethanes endowed with marked estrogenic properties are also active as biological response modifiers in animals bearing hormone-sensitive breast cancer. The antiestrogenic derivatives presumably inhibit the breast cancer development by competing with tumor growth stimulating endogenous estrogens for the binding to the receptor. This is to be confirmed in a further study.

Does [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloroplatinum(II) act on the hormone-sensitive, murine breast cancer as a biological response modifier? Part II. Studies on the influence of [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine] dichloroplatinum(II) on the specific immune defense in MXT-M-3,2 breast cancer bearing mice

The anti-tumor activity of [meso-1,2-bis(2,6-dichloro-4- hydroxyphenyl)ethylenediamine]dichloroplatinum(II) on the MXT-M-3,2 breast cancer implanted into B6D2F1 mice was not significantly reduced by splenectomy or co-administration of cyclosporine A. Neither did the use of T-lymphocyte-deficient NMRI (nu/nu) mice as hosts substantially influence its anti-tumor effect. Obviously, [meso-1,2-bis(2,6-dichloro-4- hydroxyphenyl)ethylenediamine]dichloroplatinum(II) does not act by an enhancement of the specific immune defense.

Does [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloro-platinum(II) act as an immune response modifier? Part III: Progressively growing MXT-M-3,2 breast cancer stimulates the proliferation of phagocytes in B6D2F1 mice

MXT-M-3,2 breast cancer implanted into female B6D2F1 mice accelerates the growth of an identical second tumor. This process is accompanied by a significant increase of the granulocyte and monocyte numbers in the blood and of the granulocyte and macrophage numbers in the spleen. A significant positive correlation of strong intensity was found between the tumor weight on the one hand and the number of the granulocytes and macrophages on the other hand. The tumor-dependent promotion of the myelopoiesis is explained with a secretion of hematopoietic growth factors, e.g. of the granulocyte-macrophage-stimulating growth factor (GM-CSF), by the breast cancer cells.

Structure-activity relationships of neuropeptide Y Y1 receptor antagonists related to BIBP 3226

Analogues of BIBP 3226, (R)-N(alpha)-diphenylacetyl-N-(4-hydroxybenzyl)argininamide, were synthesized and investigated for Y1 antagonism (Ca2+-assay, HEL cells) and binding on Y1, Y2 and Y5 receptors. Replacing the benzylamino by a tetrahydrobenzazepinyl group preserves most of the Y1 activity. Combination with a N(G)-phenylpropyl arginine and a N(alpha)-p-biphenylylacetyl moiety shifted the NPY receptor selectivity towards Y5.

Poliovirus and its cellular receptor: a molecular genetic dissection of a virus/receptor affinity interaction

The ability of a virus to attach to a susceptible host cell is of utmost importance for the initiation of viral life cycle. Cell surface proteins called viral receptors mediate the initial steps of virus attachment and uptake. Poliovirus (PV) is one of the most studied animal viruses and its interaction with its cellular receptor, the human poliovirus receptor (hPVR) has been well characterized. This review will present our current understanding of the PV/hPVR interaction at the genetic and biochemical level. In addition, we will also discuss the implications of the PV/hPVR interaction on PV tissue tropism and the evolution of the three PV serotypes.

Identification of a nuclear respiratory factor-1 binding site within the core promoter of the human polio virus receptor/CD155 gene

In this report we describe a cis-acting element within the core promoter of the CD155 gene specifying the polio virus receptor that is bound by the nuclear respiratory factor-1 (NRF-1) transcription factor. DNase I footprint analysis identified a nuclear protein binding site from -282 to -264 nucleotides upstream of the translation initiation codon of the CD155 gene, which we have called foot print IV (FPIV). Linker scanning mutagenesis revealed that a tandem repeat motif, GCGCAGGCGCAG, located within FPIV was essential for the basal activity of the CD155 core promoter. The results of the electrophoretic mobility shift assay experiments suggested that identical FPIV binding activities were present in a variety of nuclear extracts and that the tandem repeat was essential for binding. A one-hybrid screen was then carried out using FPIV as bait to clone the cDNA of the FPIV binding factor. The sequences of the cDNAs that were cloned from the screen were identical to NRF-1, a result that was confirmed by further electrophoretic mobility shift assay experiments. Overexpression of full-length NRF-1 and a dominant-negative form of NRF-1 modulated reporter gene expression driven by the core promoter. Remarkably, CD155 is the first gene shown to be regulated by NRF-1 that possesses an expression profile during embryogenesis correlating with this factor's proposed role in the development of the vertebrate optic system. We propose that NRF-1, which has been shown by others to be expressed during embryogenesis in animal systems, may be involved in regulating the expression of CD155 at specific stages of central nervous system development.

Sphingosine-1-phosphate is a ligand for the G protein-coupled receptor EDG-6

EDG-6 is a recently cloned member of the endothelial differentiation gene (EDG) G protein-coupled receptor family that is expressed in lymphoid and hematopoietic tissue and in the lung. Homology of EDG-6 to the known sphingosine-1-phosphate (SPP) receptors EDG-1, EDG-3, and EDG-5 and lysophosphatidic acid (LPA) receptors EDG-2 and EDG-4 suggested that its ligand may be a lysophospholipid or lysosphingolipid. We examined the binding of [(32)P]SPP to HEK293 cells, transiently transfected with cDNA encoding EDG-6. Binding of [(32)P]SPP was saturable, demonstrating high affinity (K(D) = 63 nmol/L). Binding was also specific for SPP, as only unlabeled SPP and sphinganine-1-phosphate, which lacks the trans double bond at the 4 position, potently displaced radiolabeled SPP. LPA did not compete for binding of SPP at any concentration tested, whereas sphingosylphosphorylcholine competed for binding to EDG-6, but only at very high concentrations. In addition, SPP activated extracellular signal-regulated kinase (Erk) in EDG-6 transfected cells in a pertussis toxin-sensitive manner. These results indicate that EDG-6 is a high affinity receptor for SPP, which couples to a G(i/o) protein, resulting in the activation of growth-related signaling pathways. (Blood. 2000;95:2624-2629)

Does [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloroplatinum(II) act on the hormone-sensitive, murine breast cancer as a biological response modifier? Part 1: The MXT-M-3.2 breast cancer stimulates the growth of an identical second graft; [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]dichloroplat inum (II) inhibits this process

The MXT-M-3.2 breast cancer implanted into female B6D2F1 mice accelerates the growth of an identical second tumor. This process is inhibited by [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl) ethylenediamine]dichloroplatinum(II). The possible modes of action of this compound as a biological response modifier are discussed.

Cloning and functional expression of the hNPY Y5 receptor in human endometrial cancer (HEC-1B) cells

Aiming to develop a functional assay for the human NPY Y5 receptor based on adenylyl cyclase activity, HEC-1B cells, in which cAMP synthesis can be efficiently stimulated with forskolin, were selected for the transfection with the pcDNA3-Y5-FLAG and the pcDEF3-Y5 vectors. After optimization of the transfection procedure, the binding of [3H]propionyl-NPY to transiently and stably expressed Y5 receptors was determined. The affinities of NPY, NPY derivatives, and rPP (pNPY >= p(Leu31Pro34)NPY = p(2-36)NPY >= p(D-Trp32)NPY > p(13-36)NPY > rPP) were in accordance with the NPY Y5 receptor subtype. For [3H]propionyl-pNPY approximately 1.7 × 105 and 1 × 106 binding sites per transiently and stably transfected cell, respectively, were determined. The KD values were 2.4 ± 0.4 and 1.7 ± 0.2 nM, respectively. Due to the high expression of the receptor protein, both stably and transiently transfected cells can be conveniently used in routine radioligand binding studies. By contrast, functional assays were only feasible with HEC-1B cells stably expressing the Y5 receptor. In these cells, 10 nM pNPY inhibited the forskolin-stimulated cAMP synthesis by 75%. This effect was partially antagonized by the Y5 antagonist N-{trans-[4-(2-naphthylmethylamino)- methyl]cyclohexylmethyl}naphthalene-2-sulfonamide. Although the genetic variability of cancer cells is in principle incompatible with a stable phenotype, both ligand binding characteristics and functionality of the Y5 receptor remained unchanged for more than 30 passages.Key words: human NPY Y5 receptor, HEC-1B cells, stable expression, radioligand binding, cAMP assay.

Cloning and functional expression of the hNPY Y5 receptor in human endometrial cancer (HEC-1B) cells

Aiming to develop a functional assay for the human NPY Y5 receptor based on adenylyl cyclase activity, HEC-1B cells, in which cAMP synthesis can be efficiently stimulated with forskolin, were selected for the transfection with the pcDNA3-Y5-FLAG and the pcDEF3-Y5 vectors. After optimization of the transfection procedure, the binding of [3H]propionyl-NPY to transiently and stably expressed Y5 receptors was determined. The affinities of NPY, NPY derivatives, and rPP (pNPY > or = p(Leu31Pro34)NPY = p(2-36)NPY > or = p(D-Trp32)NPY > p(13-36)NPY > rPP) were in accordance with the NPY Y5 receptor subtype. For [3H]propionyl-pNPY approximately 1.7 x 10(5) and 1 x 10(6) binding sites per transiently and stably transfected cell, respectively, were determined. The KD values were 2.4 +/- 0.4 and 1.7 +/-0.2 nM, respectively. Due to the high expression of the receptor protein, both stably and transiently transfected cells can be conveniently used in routine radioligand binding studies. By contrast, functional assays were only feasible with HEC-1B cells stably expressing the Y5 receptor. In these cells, 10 nM pNPY inhibited the forskolin-stimulated cAMP synthesis by 75%. This effect was partially antagonized by the Y5 antagonist N-¿trans-[4-(2-naphthylmethylamino)-methyl]cyclohexylmethyl) naphthalene-2-sulfonamide. Although the genetic variability of cancer cells is in principle incompatible with a stable phenotype, both ligand binding characteristics and functionality of the Y5 receptor remained unchanged for more than 30 passages.

Antispasmodic activity of Thymus vulgaris extract on the isolated guinea-pig trachea: discrimination between drug and ethanol effects

The effect of an extract of Thymus vulgaris on induced spasms was investigated on guinea-pig trachea preparations. By the experimental setup used, effects of ethanol as the vehicle could be differentiated from the activity of the herbal constituents. The extract reversibly and concentration-dependently antagonized the contraction of the Musculus transversus tracheae, provoked by four different spasmogens (BaCl2, carbachol, histamine, prostaglandin F2 alpha). The degree of the antispasmodic activity was dependent on the individual spasmogen with prostaglandin F2 alpha being most efficiently antagonized.

[meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine] sulfatoplatinum(II)--pharmacokinetic studies

The maximally attainable level of the non-plasma protein bound fraction of a single 10.0 mumol/kg i.p. dose of [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine] sulfatoplatinum(II), a drug active on the murine, hormone-sensitive MXT-M-3.2 breast cancer, lies markedly below the concentration causing a significant cytotoxic effect on a cell line derived from this tumor. This result confirms our opinion that the strong in vivo activity of this drug on hormone-sensitive breast cancers is mediated by its estrogenic potency by analogy with high dosed steroidal and non-steroidal estrogens. A specific cytotoxic effect utilizing the estrogen receptor as carrier, as formerly postulated, is unlikely.

[meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl) ethylenediamine]dichloroplatinum(II), a compound with a specific activity on hormone-sensitive breast cancers--evidence for a diethylstilbestrol-like mode of action

[meso-1,2-Bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloroplatinum(II) (meso-1-PtCl2), an estrogenic and cytotoxic platinum complex, shows activity against ER+ but not against ER- breast cancers in vivo (ER: estrogen receptor; ER+ and ER- indicate the presence or absence of the ER). To clarify whether its estrogenic or its cytotoxic potency or both properties are the cause of this specific inhibitory effect, we tested meso-1-PtCl2 comparatively in vivo on an ER+ and an ER- murine breast cancer (MXT-M-3.2 MC and MXT-M-3.2(ovex) MC, respectively), and in vitro on two cell lines derived from the former in vivo models (MXT+ and MXT-, respectively). The estrogens diethylstilbestrol (DES) and the ligand of meso-1-PtCl2 (meso-1), responsible for the hormonal effect of meso-1-PtCl2, and the cytotoxic drug cisplatin (cDDP) were used as comparative substances. Meso-1-PtCl2. DES and cDDP showed a strong and comparable activity on the ER+ MXT-M-3.2 MC in vivo, meso-1 being somewhat less inhibitory. In experiments on the murine, ER- MXT-M-3.2(ovex) MC only cDDP caused a marked inhibitory effect. The other compounds were inactive or only marginally active. In accordance with the in vivo results cDDP was also very active on the MXT+ and MXT- breast cancer cell line. In contrast to this meso-1-PtCl2, meso-1, and DES proved to be only weakly active or inactive on both cell lines. From these results it can be concluded that there is only little if any contribution of the cytotoxic PtCl2 moiety of meso-1-PtCl2 to the anti-breast cancer activity in vivo. On the ER+ MXT-M-3.2 MC transplanted into ovariectomized mice meso-1-PtCl2 yielded a biphasic dose activity curve, i.e. an increase of the tumor growth at low doses followed by a decrease at high doses, identical with those of the estrogens DES and meso-1. These results indicate that meso-1-PtCl2 inhibits ER+ breast cancers by its estrogenicity in the same manner as meso-1 and DES. The complex mechanism of anti-breast cancer active estrogens involves presumably the endocrine and/or the immune system. Its investigation is the subject of further studies.

Identification and characterization of the cis-acting elements of the human CD155 gene core promoter

The CD155 protein is the founding member of a new group of related molecules within the immunoglobulin superfamily sharing a V-C2-C2 domain structure and significant amino acid identity. We have recently isolated the promoter of the CD155 gene so that we may determine the transcription factors that regulate its expression and possibly gain insight into the cell biology of this gene. Here we report the mapping of three cis-elements within the CD155 core promoter, designated FPI, II, and III. The results of linker scanning mutagenesis suggest that all three of these cis-elements are required in varying degrees for the promoter activity of the core promoter fragment. The relative contribution of each region ranked in the following order: III > II > I. Interestingly, footprint and electrophoretic mobility shift assays show that FPIII binding activity is much reduced in a human cell line that does not express CD155. Additionally, protein binding to FPI and FPII was also investigated. DNase I footprinting using recombinant hAP-2alpha indicated that this transcription factor bound to both the FPI and FPII regions of the CD155 core promoter fragment. Electrophoretic mobility shift assays and supershift analysis confirmed the binding of AP-2 from crude nuclear extracts to FPI and to FPII. Lastly, cotransfection of the CD155 promoter with an AP-2alpha expression vector indicates that overexpression of AP-2alpha modulated the promoter activity of a CD155 promoter construct.

Stability and cellular studies of [rac-1,2-bis(4-fluorophenyl)-ethylenediamine][cyclobutane-1,1- dicarboxylato]platinum(II), a novel, highly active carboplatin derivative

The synthesis of the diastereomeric [1,2-bis(4-fluorophenyl)ethylenediamine][cyclobutane-1, 1-dicarboxylato]platinum(II) complexes, rac- and meso-4F-Pt(CBDC), the evaluation of their structures, their tumor-inhibiting properties and their stability in physiological environment are described (reference complexes: the dichloro- and sulfatoplatinum(II) analogues, carboplatin and cisplatin). The most interesting diastereomer, rac-4F-Pt(CBDC), equals cisplatin and surpasses carboplatin in its effect on human breast cancer cell lines (MCF-7 and MDA-MB-231). Rac-4F-Pt(CBDC) is largely insensitive against attack of nucleophiles e.g. Cl-, a prerequisite for sufficient stability in vivo and for fewer side effects. In accordance with this, in vitro studies on the binding of rac-4F-Pt(CBDC) to albumin, the main plasma protein, show that the free, non-protein-bound fraction is relatively high, coming close to that of carboplatin. These properties are of importance for the transferability of the promising effects found in the cell culture experiments to in vivo conditions. The distinctly better anti-breast cancer activity of rac-4F-Pt(CBDC) than of carboplatin has been attributed to its ability to accumulate in the tumor cells. The human ovarian cancer cell line NIH-OVCAR-3 is also strongly inhibited by rac-4F-Pt(CBDC).

Downstream activation of a TATA-less promoter by Oct-2, Bob1, and NF-kappaB directs expression of the homing receptor BLR1 to mature B cells

The chemokine receptor, BLR1, is a major regulator of the microenvironmental homing of B cells in lymphoid organs. In vitro studies identify three essential elements of the TATA-less blr1 core promoter that confer cell type- and differentiation-specific expression in the B cells of both humans and mice, a functional promoter region (-36 with respect to the transcription start site), a NF-kappaB motif (+44), and a noncanonical octamer motif (+157). The importance of these sites was confirmed by in vivo studies in gene-targeted mice deficient of either Oct-2, Bob1, or both NF-kappaB subunits p50 and p52. In all of these animals, the expression of BLR1 was reduced or absent. In mice deficient only of p52/NF-kappaB, BLR1 expression was unaffected. Thus our data demonstrate that BLR1 is a target gene for Oct-2, Bob1, and members of the NF-kappaB/Rel family and provides a link to the impaired B cell functions in mice deficient for these factors.

EDG6, a novel G-protein-coupled receptor related to receptors for bioactive lysophospholipids, is specifically expressed in lymphoid tissue

EDG receptors constitute a novel subfamily of G-protein-coupled receptors displaying a heterogeneous expression pattern. It was shown recently that the four members of this family thus far identified can bind lysophospholipids or lysosphingolipids as ligands. Here we report the identification and characterization of EDG6, a novel member of the EDG receptor family, isolated from in vitro differentiated human and murine dendritic cells. EDG6 is specifically expressed in fetal and adult lymphoid and hematopoietic tissue as well as in lung. The expression pattern of edg6 is strongly conserved in human and mouse. The human edg6 gene was mapped to chromosome 19p13.3 at the D19S120 marker. Considering the lymphoid-specific expression pattern of edg6 and the strong identity to the phospholipid-binding EDG receptor family, we propose that EDG6 may also act as a receptor for a lipid-derived ligand. Because of the known mitogenic and chemotactic activity of bioactive lipids, we believe that EDG6 may play an essential role in lymphocyte cell signaling.

NPY Y1 antagonists: structure-activity relationships of arginine derivatives and hybrid compounds with arpromidine-like partial structures

Previously, omega-guanidino- and omega-aminoalkanamides, structurally derived from arpromidine-like histamine H2 receptor agonists, were reported as novel neuropeptide Y Y1 antagonists. Regardless of the backbone, they resemble BIBP 3226, an argininamide with high NPY Y1 receptor affinity and selectivity, with respect to nature and arrangement of the 'terminal' diaryl, guanidine, and hydroxyphenyl groups. Hybrid compounds were synthesized combining the argininamide backbone of BIBP 3226 or partial structures derived from the C-terminal dipeptide of NPY with characteristic substructures of arpromidine- or amide-type NPY antagonists. Additionally, some analogs of BIBP 3226 with reduced flexibility were prepared. Structure-activity relationships indicate that, in contrast to alkanamides, homologs and/or isomers of BIBP 3226 with vicinal arrangement of the phenyl rings have decreased Y1 antagonistic activity (Ca2+-assay in HEL cells). Replacement of the hydroxybenzyl group by an imidazole ring further decreases activity. It is concluded that the binding sites of NPY antagonists with one and with two basic groups are not identical. Analogs with a rigid tetrahydro-2-benzazepine or an indan group in place of the benzyl moiety in BIBP 3226 are active, indicating the role of the OH group and supporting the model proposed for the interaction of BIBP 3226 with the Y1 receptor.

Quantitation of hyaluronidases by the Morgan-Elson reaction: comparison of the enzyme activities in the plasma of tumor patients and healthy volunteers

The Morgan-Elson reaction, a method for the determination of hyaluronidase activity, was optimized for the quantitation of the enzyme in biological material. Based on HPLC and spectrometric (UV-Vis, LC-MS) studies, the structure of the red-colored product (mesomeric forms of N3-protonated 3-acetylimino-2-(4-dimethylaminophenyl)methylidene-5-(1,2-++ +dihydroxyethyl)furane) formed by condensation of chromogen III with p-dimethylaminobenzaldehyde is proposed. Activities corresponding to > or = 0.1 IU of endogenous and therapeutically administered hyaluronidase can be detected in 50 microl samples. Application of the method for the determination of the enzyme in plasma of tumor patients revealed no difference in activity levels, interindividual variability and pH profile compared to healthy volunteers.

Hyaluronidase additional to standard chemotherapy improves outcome for children with malignant brain tumors

Ex vivo experiments with vital brain tumor samples show that hyaluronidase enhances the permeation of carboplatin into tumor tissue with a matrix rich in hyaluronic acid. We achieved long-lasting second remissions for children with relapsed malignant brain tumors treated with carboplatin, etoposide and this enzyme. Thereafter, we initiated a pilot study where we added hyaluronidase to the first line standard therapy to prevent the deadly relapses right from the beginning. All 19 patients with malignant brain tumors admitted to our pediatric neurooncological center from 1992 to 1994 were included in the study. Kaplan-Meier estimation of event-free survival and overall survival after 3 years follow-up indicates a significantly better outcome for the hyaluronidase-treated group. The children receiving supportive hyaluronidase suffered significantly less relapses (P = 0.034) and had a significantly better chance for survival (P = 0.045) compared to the historical control of 21 children treated with the same standard regimen but without supportive hyaluronidase (product limit analysis and the log-rank test, P < 0.05). Children aged >3 years receiving hyaluronidase together with primary treatment seemed to gain the most benefit.

Pharmacokinetics and tissue distribution of bovine testicular hyaluronidase and vinblastine in mice: an attempt to optimize the mode of adjuvant hyaluronidase administration in cancer chemotherapy

The influence of the route of administration (i.v., i.p. and s.c.) on pharmacokinetics and tissue distribution of bovine testicular hyaluronidase and vinblastine was studied in mice (plasma, skeletal muscle, liver, kidney and human melanoma). After i.v. injection, hyaluronidase was accumulated in liver and kidney, whereas i.p. and s.c. administration led to almost equal distribution in plasma, muscle, liver and kidney. In melanoma, the highest levels of hyaluronidase were found after s.c. injection of the enzyme close to the tumor. Hyaluronidase s.c. increased the intratumoral concentration of s.c. co-administered vinblastine most efficiently, making local simultaneous application as in interstitial chemotherapy most promising.

Intracellular and surface expression of the HIV-1 coreceptor CXCR4/fusin on various leukocyte subsets: rapid internalization and recycling upon activation

We describe the expression and regulation of the HIV-1 coreceptor CXCR4/fusin. Using anti-CXCR4 mAb, we demonstrate that this chemokine receptor is highly expressed on neutrophils, monocytes, B cells, and naive T cells among peripheral blood cells. In secondary lymphoid organs CXCR4 was found to be expressed on B cells. However, individual variations with regard to surface expression could be observed on T cells. Expression of the receptor is not confined to the cell surface, as large amounts of intracellular stores can be found on various leukocytes. Upon activation with phorbol esters the amount of cell surface-expressed CXCR4 on lymphocytes increases twofold within 30 s before it is completely down-regulated within the next 2 min. Incubation of leukocytes with stroma derived factor-1alpha, the natural ligand for CXCR4, induces down-regulation of up to 60% of surface-expressed receptors in a pertussis toxin-insensitive manner. Interestingly, receptor cross-linking caused by incubation of cells with anti-CXCR4 mAb triggers receptor trafficking, in that the receptor is rapidly internalized and recycled to the cell surface. Therefore, receptor internalization and recycling may regulate the functional interaction of the receptor with envelope proteins during an initial step of HIV-1 infection.

Synthesis and neuropeptide Y Y1 receptor antagonistic activity of N,N-disubstituted omega-guanidino- and omega-aminoalkanoic acid amides

Potent arpromidine-type histamine H2 receptor agonists such as BU-E-76 (He 90481) were among the first non-peptides reported to display weak neuropeptide Y (NPY) Y1 receptor antagonist activity. In search of new chemical leads for the development of more potent NPY antagonists, a series of N,N-disubstituted omega-guanidino and omega-aminoalkanoic acid amides were synthesized on the basis of structure-activity relationships and molecular modeling studies of arpromidine and related imidazolylpropylguanidines. In one group of compounds the imidazole ring was retained whereas in the second group it was replaced with a phenol group representing a putative mimic of Tyr36 in NPY. Although the substitution patterns have not yet been optimized, the title compounds are NPY Y1 antagonists in human erythroleukemia (HEL) cells (Ca2+ assay) achieving pKB values in the range of 6.3-6.6. For representative new substances tested in the isolated guinea pig right atrium histamine H2 receptor agonism could not be found. In the N-(diphenylalkyl)amide series, compounds with a trimethylene chain were more active Y1 antagonists than the ethylene homologs. Concerning the spacer in the omega-amino or omega-guanidinoalkanoyl portion, the best activity was found in compounds with a four- or five-membered alkyl chain or a 1,4-cyclohexylene group. Surprisingly, in contrast to the phenol series, in the imidazole series the compounds with a side chain amino group turned out to be considerably more potent than the correspondence strongly basic guanidines. Thus, the structure-activity relationships appear to be different for the diphenylalkylamide NPY antagonists with one or two basic groups.

Analyzing cytotoxic T lymphocyte activity: a simple and reliable flow cytometry-based assay

A flow cytometry-based assay for analyzing cytotoxic T lymphocyte (CTL) activity is presented. This new approach is characterized by easy handling, the generation of highly reproducible data sets and is not dependent on the use of radioactivity. Before exposure to primed CTL effector cells the target cells were labeled with the green fluorescent dye DiO18(3) which is incorporated stably into the cell membrane. After a 4-h incubation period, samples were counterstained with the red fluorescent nuclear dye propidium iodide in order to permit discrimination between live and dead cells within both cell populations. The assay has been used to quantitate CTL effector activity against allogeneic lymphoblasts. Results derived from this novel flow cytometry assay show an excellent correlation (r = 0.988) with data obtained using the standard 51chromium release assay. An additional advantage of the assay is that freshly prepared splenocytes may be used as target cells because culturing and activation of target cells is no longer required. The results demonstrate that the fluorescent dyes DiO18(3) and propidium iodide in combination with flow cytometry permit accurate analysis of cytotoxic T cell activity.

High-resolution reversed-phase high-performance liquid chromatography analysis of polyamines and their monoacetyl conjugates by fluorescence detection after derivatization with N-hydroxysuccinimidyl 6-quinolinyl carbamate

A highly sensitive, accurate, and reproducible HPLC method for the determination of all natural polyamines and their monoacetyl conjugates is described. The presented method is based on precolumn derivatization with N-hydroxysuccinimidyl 6-quinolinyl carbamate (HSQC) followed by C18-HPLC separation using a ternary gradient and fluorescence detection (lambda Ex = 248 nm, lambda Em = 398 nm). The derivatives of the four main polyamines (putrescine, cadaverine, spermidine, and spermine) and the internal standard were synthesized on a preparative scale and characterized, especially with respect to their molar absorptivities and fluorescence quantum yields. The limits of detection of the highly stable derivatives ranged from 30 to 130 fmol (injection volume 10 microliters) for putrescine and N-acetylcadaverine, respectively (signal to noise ratio = 10), with excellent linearity within the range from 1 to 100 microM. High reproducibility for both retention times and peak areas, with coefficients of variation ranging from 0.14 to 0.88% and from 1.83 to 3.80%, respectively, were achieved. Provided that deproteinization of the samples was carried out immediately, recoveries of the analytes from homogenates of pancreatic cancer xenografts were high and reproducible. The optimized method was applied to the determination of the polyamine content of cultured pancreatic cancer cells and of tissue from colorectal adenocarcinoma, proving precise and reproducible quantification in these complex biological matrices.