Acute heart failure in the parturient--do not forget phaeochromocytoma

Phaeochromocytoma is a rare condition and extremely rare in pregnancy. Diagnosis is notoriously difficult, as phaeochromocytoma may present a broad spectrum of clinical manifestations. The key to a successful outcome is a high index of suspicion of its existence and its early diagnosis.

Specifics on the refinement and application of two serological assays for the detection of antibodies to HHV-8

BACKGROUND

Serologic assays for the detection of antibodies to human herpesvirus type 8 (HHV-8) are important for epidemiological studies and to further investigate the proposed pathogenesis of the virus in cancer. Although a variety of assays are available, a lack of optimization and standardization makes their usefulness uncertain, and may be responsible for the controversy concerning the prevalence of infection.

OBJECTIVES

To refine an indirect immunofluorescent assay (IFA) for the detection of latent antibodies and a recombinant ORF 65 ELISA for the detection of lytic antibodies in order to increase their ability to differentiate individuals at higher and lower risk for HHV-8 infection.

STUDY DESIGN

Sera from Kaposi's sarcoma (KS) patients and blood donors (BDs) were used to modify assay parameters in an attempt to better discriminate between the two populations. Modifications included methods of substrate fixation, incubation times, sample dilution, and antigen/conjugate concentrations.

RESULTS

Optimal modifications to the latent IFA included acetone fixation of substrate, and dilution of sera to 1:64 which enhanced detection of HHV-8 antibodies from 68 to 92% in the KS population. Similarly, successful refinement of the ORF 65 ELISA to increase the signal-to-noise ratio included the use of 88 ng of ORF 65 antigen per well and serum dilutions of 1:50. Optical density-to-cut-off ratios directly correlated with titers, thereby introducing a strategy to predict antibody concentrations. The ORF 65 ELISA and the latent IFA were both able to discriminate between the two populations but with different efficiencies.

CONCLUSIONS

Although neither the latent IFA nor the ORF 65 ELISA produced perfect test indices, improvement in their performances was noted following the optimization strategies. The ELISA produced better detection of antibodies to the virus than the IFA and permitted prediction of sample titers, thus improving cost and time effectiveness.

A robust mixed linear model analysis for longitudinal data

This paper describes robust procedures for estimating parameters of a mixed effects linear model as applied to longitudinal data. In addition to fixed regression parameters, the model incorporates random subject effects to accommodate between-subjects variability and autocorrelation for within-subject variability. Robust empirical Bayesian estimation of subject effects is briefly discussed. As an illustration, the procedures are applied to data from a multiple sclerosis clinical trial.

Results of a randomized study of IM862 nasal solution in the treatment of AIDS-related Kaposi's sarcoma

PURPOSE

Although advances have been made in the treatment of AIDS-related Kaposi's sarcoma (AIDS-KS) with systemic chemotherapy, less toxic therapies are needed. IM862 is a naturally occurring peptide with antiangiogenic properties and was thus studied in patients with AIDS-KS.

PATIENTS AND METHODS

IM862 was given as intranasal drops at a dose of 5 mg. Patients were randomized to two dosing schedules given in repeated cycles until disease progression or unacceptable toxicity: 5 days of therapy followed by 5 days off (n = 18) and every other day dosing (n = 26).

RESULTS

Forty-two male patients and two female patients with a median age of 38 years (range, 22 to 53 years) were accrued. Twenty-one patients (47%) had more than 50 mucocutaneous lesions, 14 (32%) had lymphedema, and none had visceral involvement. Thirty-three patients (75%) had received prior systemic chemotherapy. Twenty-four patients (55%) had CD4(+) lymphocyte count </= 200/mm(3). All but five patients were being treated with concurrent protease inhibitor(s), for a median of 10 months (range, 0 to 24 months). Major responses were documented in 36%, with five complete and 11 partial remissions, occurring after a median of 6 weeks (range, 3 to 26 weeks) and lasting a median of 33+ weeks (range, 12+ to 95+ weeks). Twenty-one patients had stable disease for periods of 7 to 72+ weeks. Adverse effects to IM862 were limited to mild and transient headache, fatigue, tingling, and nausea. No hematologic adverse effects attributed to treatment were reported.

CONCLUSION

IM862 given as intranasal drops is well tolerated and has antitumor activity in patients with AIDS-KS. A randomized double-blinded study to define the activity of IM862 in patients with AIDS-KS is in progress.

c-Src mediates mitogenic signals and associates with cytoskeletal proteins upon vascular endothelial growth factor stimulation in Kaposi's sarcoma cells

Vascular endothelial growth factor (VEGF) appears to be a critical cytokine modulating the growth and spread of Kaposi's sarcoma (KS). Furthermore, infection with the KS herpes virus results in up-regulation of VEGF and triggering of VEGF receptor activation. The molecular mechanisms regulating such cytokine-driven proliferation of KS cells are not well characterized. We investigated the role of Src-related tyrosine kinases in VEGF-mediated signaling in model KS 38 tumor cells. VEGF stimulation specifically activated c-Src kinase activity but not that of other related Src kinases such as Lyn, Fyn, or Hck in KS cells. Pyrazolopyrimidine, a selective inhibitor of Src family tyrosine kinases, significantly blocked the VEGF-induced growth of KS cells. Further studies using mutants of c-Src kinase revealed that Src mediates mitogen-activated protein kinase activation induced by VEGF. We also observed that VEGF stimulation resulted in increased tyrosine phosphorylation of the focal adhesion components paxillin and p130cas. Furthermore, VEGF induction enhanced the complex formation between Src kinase and paxillin. Src kinase appears to play an important functional role in VEGF-induced signaling in KS cells and may act to link pathways from the VEGF receptor to mitogen-activated protein kinase and cytoskeletal components, thereby effecting tumor proliferation and migration.

Azidothymidine and interferon-alpha induce apoptosis in herpesvirus-associated lymphomas

Lymphoproliferative diseases that occur in immunocompromised patients are frequently associated with herpesviruses. These patients often fare poorly after treatment with conventional chemotherapy. We reported previously that patients with AIDS-related Burkitt's lymphoma (BL) responded to parenteral azidothymidine (AZT) and IFN-alpha. We found that EBV-positive lymphoma cells derived from these patients cultured with AZT express CD95 and undergo apoptosis. AZT-mediated apoptosis was caspase dependent and occurred despite Fas receptor blockade. In contrast, EBV-negative lymphomas were resistant to AZT-induced apoptosis, as were EBV-positive lymphomas that expressed high levels of bcl-2. Primary effusion lymphoma (PEL) cell lines infected with human herpesvirus type 8 required IFN-alpha to potentiate AZT-induced apoptosis. IFN-alpha did not up-regulate CD95 in BL or PEL but did induce expression of the death receptor ligand, CD95 ligand. AZT-sensitive lymphomas also accumulated significantly higher intracellular AZT monophosphate than did resistant lymphomas. Our data demonstrated distinct apoptotic responses to AZT and IFN-alpha in herpesvirus-associated lymphomas. EBV-positive BL cells that expressed low BCL-2 levels were sensitive to AZT alone; PEL cells required the addition of IFN-alpha to enhance apoptosis, and EBV-negative lymphomas were insensitive to both agents. AZT-sensitive BL cells transfected with BCL-2 became resistant. Susceptibility to antivirus-mediated apoptosis may be exploited to improve the therapy of certain herpesvirus-associated lymphomas.

Educating medical students for work in culturally diverse societies

CONTEXT

Recent attention has focused on whether government health service institutions, particularly in the United Kingdom, reflect cultural sensitivity and competence and whether medical students receive proper guidance in this area.

OBJECTIVE

To systematically identify educational programs for medical students on cultural diversity, in particular, racial and ethnic diversity.

DATA SOURCES

The following databases were searched: MEDLINE (1963-August 1998); Bath International Data Service (BIDS) Institute for Scientific Information science and social science citation indexes (1981-August 1998); BIDS International Bibliography for the Social Sciences (1981-August 1998); and the Educational Resources Information Centre (1981-August 1998). In addition, the following online data sets were searched: Kings Fund; Centre for Ethnic Relations, University of Warwick; Health Education Authority; European Research Centre on Migration and Ethnic Relations, University of Utrecht; International Centre for Intercultural Studies, University of London; the Refugee Studies Programme, University of Oxford. Medical education and academic medicine journals (1994-1998) were searched manually and experts in medical education were contacted.

STUDY SELECTION

Studies included in the analysis were articles published in English before August 1998 that described specific programs for medical students on racial and ethnic diversity. Of 1456 studies identified by the literature search, 17 met the criteria. Two of the authors performed the study selection independently.

DATA EXTRACTION

The following data were extracted: publication year, program setting, student year, whether a program was required or optional, the teaching staff and involvement of minority racial and ethnic communities, program length, content and teaching methods, student assessment, and nature of program evaluation.

DATA SYNTHESIS

Of the 17 selected programs, 13 were conducted in North America. Eleven programs were exclusively for students in years 1 or 2. Fewer than half (n = 7) the programs were part of core teaching. Only 1 required program reported that the students were assessed on the session in cultural diversity.

CONCLUSIONS

Our study suggests that there is limited information available on an increasingly important subject in medical education. Further research is needed to identify effective components of educational programs on cultural diversity and valid methods of student assessment and program evaluation.

Changing doctor prescribing behaviour

The aim of this overview was to identify interventions that change doctor prescribing behaviour and to derive conclusions for practice and further research. Relevant studies (indicating prescribing as a behaviour change) were located from a database of studies maintained by the Cochrane Collaboration on Effective Professional Practice. This register is kept up to date by searching the following databases for reports of relevant research: DHSS-DATA; EMBASE; MEDLINE; SIGLE; Resource Database in Continuing Medical Education (1975-1994), along with bibliographies of related topics, hand searching of key journals and personal contact with content area experts. Randomised controlled trials and non-equivalent group designs with pre- and post-intervention measures were included. Outcome measures were those used by the study authors. For each study we determined whether these were positive, negative or inconclusive. Positive studies (+) were those that demonstrated a statistically significant change in the majority of outcomes measured at level of p < or = 0.05 between the intervention and control groups. Negative studies (-) showed a significant change in the opposite direction and inconclusive studies (approximately) showed no significant change compared to control or no overall positive findings. We identified 79 eligible studies which described 96 separate interventions to change prescribing behaviour. Of these interventions, 49 (51%, 41%-61%) showed a positive significant change compared to the control group but interpretation of specific interventions is limited due to wide and overlapping confidence intervals.

Expression of the human immunodeficiency virus-Tat gene in lymphoid tissues of transgenic mice is associated with B-cell lymphoma

The human immunodeficiency virus type 1 (HIV-1) Tat gene, a potent transactivator of viral and cellular genes, has been proposed as a key agent in the pathogenesis of acquired immune deficiency syndrome related disorders, including non-Hodgkin's lymphoma. In cultured cells, the HIV-1 Tat protein can induce the expression of the cytokines interleukin-6 (IL-6) and IL-10, which are known to induce proliferation and differentiation of lymphoid cells. Such alterations in cytokine expression, together with a secondary genetic event, are thought to ultimately lead to oncogenic transformation. To address the influence of Tat on lymphoid development in the context of the whole organism, we produced several transgenic mouse lines that express the Tat gene under the control of an actin promoter. We show here that this promoter directs expression to a variety of sites, including spleen, bone marrow, and lymph nodes. Approximately 25% to 30% of the Tat-transgenic population developed enlarged spleens within 1 year after birth. On histological examination, a significant number of spleens from Tat-transgenic mice exhibited malignant lymphoma of B-cell origin. IgG heavy chain rearrangement confirmed the clonal B-cell nature of these lymphoproliferations. In contrast, T-cell receptor genes exhibited a germline (unrearranged) structure. Reverse transcription polymerase chain reaction analysis of transgenic spleens revealed that mRNA encoding cytokines IL-6 and IL-10 was upregulated, suggesting a possible mechanism for the B-cell expansion in vivo.

Paclitaxel is safe and effective in the treatment of advanced AIDS-related Kaposi's sarcoma

PURPOSE

Liposomal anthracyclines are the present standard treatment for advanced AIDS-related Kaposi's sarcoma (KS). No effective therapies have been defined for use after treatment failure of these agents. A phase II trial was thus conducted with paclitaxel in patients with advanced KS to assess safety and antitumor activity.

MATERIALS AND METHODS

A regimen of paclitaxel at a dose of 100 mg/m(2) was given every 2 weeks to patients with advanced AIDS-related KS. Patients were treated until complete remission, disease progression, or unacceptable toxicity occurred.

RESULTS

Fifty-six patients with advanced AIDS-related KS were accrued. Tumor-associated edema was present in 70% of patients and visceral involvement in 45%. Forty patients (71%) had received prior systemic therapy; 31 of these were resistant to an anthracycline. The median entry CD4(+) lymphocyte count was 20 cells/mm(3) (range, 0 to 358). A median of 10 cycles (range, 1 to 54+) of paclitaxel was administered. Fifty-nine percent of patients showed complete (n = 1) or partial response (n = 32) to paclitaxel. The median duration of response was 10.4 months (range, 2.8 to 26.7+ months) and the median survival was 15.4 months. The main side effects of therapy were grade 3 or 4 neutropenia in 61% of patients and mild-to-moderate alopecia in 87%.

CONCLUSION

Paclitaxel at 100 mg/m(2) given every 2 weeks is active and well tolerated in the treatment of advanced and previously treated AIDS-related KS. The median duration of response is among the longest observed for any regimen or single agent reported for AIDS-related KS. Paclitaxel at this dosage and schedule is a treatment option for patients with advanced AIDS-related KS, including those who have experienced treatment failure of prior systemic therapy.

The effect of doctor ethnicity and country of qualification on prescribing patterns: an ecological study

OBJECTIVE

To assess the effect of doctor ethnicity and country of qualification on prescribing patterns.

DESIGN

Ecological study.

SETTING

90 Family Health Services Authorities in the U.K.

RESULTS

Being an Asian doctor and qualifying from the Indian subcontinent contributes to 5% of the observed variation seen in the frequency of prescribing, but not the cost. The major determinant of variation in prescribing is deprivation, which accounts for 14% of the cost and 32% of the frequency of prescribing.

CONCLUSIONS

Being an Asian doctor and qualifying from the Indian subcontinent contributes to the frequency, but not the cost of prescribing variation. As this study was at the FHSA level, 'ecological fallacy' exists and further research is advocated at the individual doctor level.

Antineoplastic urinary protein inhibits Kaposi's sarcoma and angiogenesis in vitro and in vivo

Kaposi's sarcoma (KS) is the most common tumor in human immunodeficiency virus infection and acquired immune deficiency syndrome. Recent clinical trials with human chorionic gonadotropin (hCG) prepared from early pregnancy urine have shown encouraging results in the resolution of KS lesions. A urinary protein with antitumor activity, ANUP (antineoplastic urinary protein), a dimer of 32 kD, has previously been shown to inhibit the growth of various tumor cell lines in vivo. It was thus studied for its activity in KS cell lines in vitro and in vivo to determine whether it could be a source of the anti-KS activity observed in hCG preparations. ANUP is a strong growth inhibitor for KS cell lines, but has little or no effect on fibroblast, aortic smooth muscle, T- and B-lymphocyte, and monocyte cell lines. ANUP also inhibited the proliferation of endothelial cell lines, suggesting that the in vitro effects were endothelial cell lineage-specific. However, ANUP antibodies did not block the inhibitory effect of certain commercial preparations of hCG, previously shown to be active in KS. Thus, the active protein in these commercial preparations of hCG may be distinct from ANUP. The antitumor activity of ANUP was further confirmed in a chicken allantoic membrane (CAM) assay in which vascular endothelial growth factor (VEGF) and beta fibroblast growth factor (bFGF)-induced angiogenesis was inhibited by ANUP in a dose-dependent manner. In vivo activity of ANUP was demonstrated in the murine model of KS, where ANUP inhibited tumor growth. ANUP is thus a potential candidate for development in the treatment of KS and other diseases in which angiogenesis plays an important role.

Vascular endothelial growth factor chimeric toxin is highly active against endothelial cells

Angiogenesis is a critical step in a benign tumor's evolution toward malignancy and metastasis. Tumor cells acquire such a phenotype by their ability to secrete angiogenic factors such as vascular endothelial growth factor (VEGF). VEGF receptors (VEGFRs) flt-1/VEGFR-1 and Flk-1/ KDR/VEGFR-2 are restricted to activated endothelial cells, with the highest expression being in the tumor vasculature. The present study was undertaken to target the VEGFRs. Targeted toxins were developed by recombinant methods by fusing VEGF165 or VEGF121 to the diphtheria toxin (DT) translocation and enzymatic domain (DT390-VEGF165 or DT390-VEGF121). Both fusion proteins were found to be highly toxic to proliferating endothelial cells but not to vascular smooth muscle cells. The fusion protein is also active in Kaposi's sarcoma, a tumor type that expresses high levels of VEGFRs. These fusion proteins completely inhibit the basic fibroblast growth factor-induced growth of new blood vessels in the chick chorioallantoic membrane assay. Furthermore, the fusion toxin substantially retards the growth of Kaposi's sarcoma tumors in mice. Because nearly all tumors induce local angiogenesis with high VEGFR expression, VEGF-derived toxins may have wide application in cancer therapy.

Phase II trial of liposomal daunorubicin in the treatment of AIDS-related pulmonary Kaposi's sarcoma

PURPOSE

Kaposi's sarcoma (KS) is the most common tumor in patients with AIDS and can be fatal in patients with lung involvement. Systemic chemotherapy is the most effective treatment for pulmonary KS. We thus conducted this study to determine the efficacy of liposomal daunorubicin in the treatment of patients with pulmonary KS.

METHODS

Patients with biopsy-proven, symptomatic pulmonary KS were accrued. Liposomal daunorubicin was given at a dose of 60 mg/m2 intravenously every 2 weeks. Response was monitored by chest radiographs, pulmonary function tests, arterial blood gases, and grading of pulmonary symptoms.

RESULTS

Fifty-three male patients were accrued. The median CD4+ lymphocyte count was 13/microL (range, 0 to 200); 70% reported a prior AIDS-defining opportunistic infection. All patients were symptomatic, with cough reported in all patients, shortness of breath in 94%, and hemoptysis in 55%. The mean study entry diffusing capacity of carbon monoxide (DLCO) was 58.5% (percent of predicted). The median dose of liposomal daunorubicin delivered was 360 mg/m2 (range, 60 to 1,380). More than 75% of patients had complete or partial resolution of baseline pulmonary symptoms. Complete or partial improvement in DLCO was observed in 22%; complete or partial resolution of radiographic abnormalities was reported in 32%. The most common treatment-related toxicity was neutropenia, which occurred in 85%. There were no instances of cardiac toxicity observed, even at high cumulative doses.

CONCLUSION

Liposomal daunorubicin at 60 mg/m2 is safe and active in patients with pulmonary KS. Trials combining liposomal daunorubicin with other active agents in KS should be considered.

Emerging treatments for epidemic (AIDS-related) Kaposi's sarcoma

Kaposi's sarcoma (KS) is an opportunistic tumor that develops with increased frequency (100,000-fold) after HIV infection. KS causes significant morbidity from mucocutaneous involvement and mortality from complications of visceral sites of disease such as the lungs, gastrointestinal tract, and the liver. Progressive unraveling of the KS pathogenesis has lead to the development of novel therapeutic approaches. Newest therapies are first evaluated in patients with limited tumor burden. These include: 1) inhibitors of angiogenesis such as vascular endothelial growth factor signaling inhibitor (SU 5416), and several other inhibitors of angiogenesis such as the dipeptide IM 862, TNP-470, Col-3, and thalidomide; 2) topical and systemic retinoids; 3) antiviral agents specific for Kaposi's sarcoma herpesvirus and human herpesvirus-8, or HIV; and 4) pregnancy-related factors. Patients with advanced disease such as widespread mucocutaneous disease, lymphedema, and visceral disease are treated most effectively with cytotoxic agents. The most active agents include liposomal anthracyclines, paclitaxel, vinca alkaloids, and bleomycin. The combination of liposomal anthracyclines and paclitaxel, with and without the most promising biologicals, should now be studied to further reduce the toxicity, and enhance the antitumor effects. Furthermore, identification of risk factors for KS should serve to explore prophylactic therapies.

Liposome-anchored vascular endothelial growth factor aptamers

Nuclease-resistant aptamers identified from randomized nucleic acid libraries represent a novel class of drug candidates. Aptamers are synthesized chemically and therefore can be readily modified with functional groups that modulate their properties. We report here on the preparation, initial characterization, and functional properties of a nuclease-resistant vascular endothelial growth factor (VEGF) aptamer anchored in liposome bilayers through a lipid group on the aptamer. While the high-affinity binding to VEGF is maintained, the plasma residence time of the liposome-anchored aptamer is considerably improved compared with that of the free aptamer. The lipid group attachment and/or liposome anchoring leads to a dramatic improvement in inhibitory activity of the aptamer toward VEGF-induced endothelial cell proliferation in vitro and vascular permeability increase and angiogenesis in vivo.

Evidence for multiclonality in multicentric Kaposi's sarcoma

Kaposi's sarcoma (KS) develops in a variety of clinical states and is the most common tumor seen in patients with HIV-1 infection. KS develops as a multifocal mucocutaneous disease with subsequent spread to visceral organs, and it has been argued to be a benign proliferation caused by its multifocality at initial presentation, lack of aneuploidy, and spontaneous regression upon withdrawal of immunosuppressive agents in iatrogenically induced disease. We wished to determine whether KS lesions are clonal, indicative of a true neoplasm. Also, we tested whether multifocal KS lesions are clonally related, derived from a common progenitor cell or of independent cellular origin. We studied the X-chromosome inactivation pattern of the human androgen receptor gene in tumor biopsies of women with KS. This procedure tests for the clonality of a tissue specimen, a hallmark of neoplasia. Each specimen was microdissected to minimize normal cell contamination. Of 12 evaluable cases, 10 were HIV-seropositive and 2 were HIV-seronegative. Twenty-four biopsies from the 12 patients were examined. Five cases were consistent with individual KS lesions being clonal. In two cases, multiple KS specimens derived from the individual patients had different androgen receptor alleles inactivated, proving unequivocally that these KS lesions arose independently from distinct transformed cells. In seven cases, only a polyclonal pattern of inactivation was observed, whereas two others had tumor areas of both clonal and polyclonal inactivation patterns. These findings suggest that KS can be a clonal neoplasm, and in some of the cases multiple KS lesions in a given patient can arise from independent cellular origins and acquire clonal characteristics. The polyclonal inactivation pattern observed in other KS lesions may represent a premalignant stage or false negative results.

Detection and titration of human herpesvirus-8-specific antibodies in sera from blood donors, acquired immunodeficiency syndrome patients, and Kaposi's sarcoma patients using a whole virus enzyme-linked immunosorbent assay

A human herpesvirus-8 (HHV-8) enzyme-linked immunosorbent assay (ELISA) with a whole virus lysate as antigen was developed and used to measure the seroprevalence rate and levels of IgG antibodies to HHV-8 in sera/plasma of various patient groups and blood donors. The virus antigen was prepared from the KS-1 cell line, which produces lytic virus, and therefore contains a broad array of viral proteins. Seroprevalence studies using this ELISA showed the following: 10 of 91 blood donors (11%) had an average HHV-8 antibody titer of 118; 67 of 72 (93%) classic Kaposi's sarcoma (KS) patients were positive with an average titer of 14,111; and 57 of 62 (92%) KS/human immunodeficiency virus (HIV) patients were positive with an average titer of 4,000. A study on a very limited number of serial serum samples from patients before and after diagnosis with KS showed highly elevated antibody titers to HHV-8 virus after KS lesions developed. Preliminary data show that 50% of the sera from HIV-1(+) homosexual patients contain IgG antibodies to HHV-8 suggesting that this population is at high risk for developing KS. Antibody results correlated well with the confirmatory immunofluorescent assays (IFA) using KS-1 cells as the substrate. This HHV-8 IgG antibody detection ELISA is sensitive and specific and does not cross-react with Epstein-Barr virus (EBV) or other human herpesviruses. The results of this HHV-8 antibody survey suggest that this rapid ELISA assay can be used to screen large numbers of sera to find those at risk for developing KS.

IL-4R expression in AIDS-KS cells and response to rhIL-4 and IL-4 toxin (DAB389-IL-4)

Interleukin-4 (IL-4) is a pleiotropic cytokine affecting growth and differentiation of various cell types as well as regulating other cytokines. To study the effect of IL-4 on AIDS-related Kaposi's sarcoma (AIDS-KS) cells, we first examined the tumor cells for IL-4 receptor (IL-4R) expression. KS cells express a single 4 kB IL-4R-specific mRNA and 1828 +/- 408 high affinity IL-4 binding sites per cell with a dissociation constant (Kd) of 154 +/- 37 pM. Addition of recombinant human IL-4 (rIL-4) minimally inhibited AIDS-KS cell growth and expression of IL-6. We then studied the effects of a chimeric fusion toxin DAB389-IL-4 which exerts cellular toxicity only on cells expressing IL-4R. DAB389-IL-4 inhibited protein synthesis in AIDS-KS cells at low concentrations (IC50 of 5 x 10(-11) M). This effect was abrogated by neutralizing antibody to IL-4 (25D2). We conclude that KS cells express a functional IL-4R and this receptor could serve as a target for novel therapy with agents such as DAB389-IL-4.

Fumagillin analog in the treatment of Kaposi's sarcoma: a phase I AIDS Clinical Trial Group study. AIDS Clinical Trial Group No. 215 Team

PURPOSE

Angiogenesis is a major component of Kaposi's sarcoma (KS) and a critical process in tumor growth. The present study was designed primarily to test the toxicity and pharmacokinetics (PK) of the angiogenesis inhibitor TNP-470 and secondarily to evaluate tumor response in patients with early AIDS-related KS.

PATIENTS AND METHODS

Patients with AIDS-related KS were required to have cutaneous disease with > or = 5 measurable lesions and no evidence of pulmonary, symptomatic gastrointestinal, or acutely life-threatening KS. Thirty-eight patients received TNP-470 by weekly intravenous infusion over 1 hour at one of six dose levels for up to 24 weeks.

RESULTS

The dose levels tested included 10, 20, 30, 40, 50 and 70 mg/m2. Median CD4 count was 24 cells/microl (range, 0 to 460). Fourteen patients (36%) had > or = 50 cutaneous lesions and 19 (49%) had oral lesions. Adverse events included neutropenia (n = 2), hemorrhage (n = 3), and urticaria (n = 1). PK studies showed wide interpatient and intrapatient variability. Elimination half-life values were short (range, 0.01 to 0.61 hours). Seven patients (18%) achieved a partial response. The median time to partial response was 4 weeks (range, 2 to 25), and the median duration of response was 11 weeks (range, 3 to 26+).

CONCLUSION

TNP-470, administered as a weekly, 1-hour infusion to patients with early AIDS-KS is well-tolerated at doses up to and including the highest dose tested. Tumor responses were observed in a substantial number of cases and occurred at various dose levels. TNP-470 should be evaluated further in patients with AIDS-KS as a single agent and in combination with other biologic response modifiers in early disease or after initial response to cytotoxic chemotherapy.

Interleukin-1 regulation of corticotropin-releasing factor (CRF), glucocorticoid receptor, c-fos and c-jun messenger RNA in the NPLC-KC cell line

The NPLC-KC human hepatoma cell line expresses corticotropin-releasing factor (CRF) and it has been demonstrated that CRF secretion and synthesis in this cell line increases in response to activators of the protein kinase A (PKA) and C (PKC) pathways as well as interleukin-1 (IL1). CRF expression with all three agents can be inhibited with the synthetic steroid-dexamethasone (DEX). In this report, we have examined the effect of IL1 (beta form) in the presence and absence of DEX on CRF mRNA (mRNA) expression as well as the expression of human glucocorticoid receptor (GR) mRNA and the mRNA of the proto-oncogenes (c-jun and c-fos) that have been implicated in CRF regulation. NPLC-KC cells were incubated with picomolar concentrations of IL1. Following this total RNA was extracted from the cells and Northern Blots were probed with 32P-labelled human DNA probes for the CRF, GR, c-jun and c-fos genes. Levels of mRNA expression were measured using a PhosphoImager and were normalized to mRNA levels of control probe glyceraldehyde-3-phosphate dehydrogenase (GAPD). CRF mRNA was significantly increased with IL1 treatment in a time and concentration dependent manner. CRF mRNA expression increased with increasing concentrations of IL1 over the range of 1-100 pM; expression of CRF mRNA also peaked after 24 h of 100 pM IL1 treatment and reached a level of expression approximately seven times higher than control. This pattern of expression was significantly inhibited in the presence of 100 nM DEX. Levels of the GR, c-fos and c-jun mRNAs were also significantly increased in the presence of IL1 and inhibited when DEX was co-incubated with IL1. The results reveal that IL1 stimulation of CRF mRNA expression by IL1 in the NPLC-KC cell line is accompanied by activation of GR mRNA as well as the mRNA of the immediate early genes--c-fos and c-jun. The results also demonstrate that this cell line may serve as a model system for the molecular mechanisms by which IL1 regulates CRF in central nervous system (CNS) neurons.