Innovation in cardiovascular drugs: drug development portfolios. 3-4 March 1999, London, UK

This conference, organized by SMi, brought together representatives from some of the leading companies in cardiovascular (CV) drug development. The two-day meeting was chaired by Dr Ajay Kakkar (Thrombosis Research Institute, London, UK) and covered drug development portfolios, genetic approaches to therapy and innovative therapeutic strategies.

Molecular-weight-dependent effects of nonanticoagulant heparins on allergic airway responses

We have hypothesized that antiallergic activity of inhaled heparin is molecular weight dependent and mediated by "nonanticoagulant fractions" (NAF-heparin). Therefore, we studied comparative effects of high-, medium-, and ultralow-molecular-weight (HMW, MMW, and ULMW, respectively) NAF-heparins on acute bronchoconstrictor response (ABR) and airway hyperresponsiveness (AHR) in allergic sheep. Specific lung resistance was measured in 23 allergic sheep, before and immediately after challenge with Ascaris suum antigen, without and after pretreatment with inhaled NAF-heparins. Airway responsiveness was estimated before and 2 h postantigen as the cumulative provocating dose of carbachol in breath units, which increased specific lung resistance by 400%. NAF-heparins attenuated ABR and AHR in a molecular-weight-dependent fashion. HMW NAF-heparin (n = 8) was the least effective agent: it attenuated ABR [inhibitory dose causing 50% protection (ID50) = 4 mg/kg] but had no effect on AHR. MMW NAF-heparin (n = 8) showed intermediate efficacy (ABR ID50 = 0.8 mg/kg, AHR ID50 = 1.4 mg/kg), whereas ULMW NAF-heparin (n = 7) was the most effective agent (ABR ID50 = 0.4 mg/kg, AHR ID50 = 0.2 mg/kg). ULMW NAF-heparin was 3.5 times more potent in attenuating antigen-induced AHR when administered "after" antigen challenge and failed to inhibit the bronchoconstrictor response to carbachol and histamine. In 15 additional sheep, segmental antigen challenge caused a marked increase in histamine in bronchoalveolar lavage fluid that was not prevented by any of the inhaled NAF-heparins. These data indicate that antiallergic activity of inhaled heparin is independent of its anticoagulant action and resides in the <2,500 ULMW chains. The antiallergic activity of NAF-heparins is mediated by an unknown biological action and may have therapeutic potential.

A study of the cost effectiveness of selective health interventions for the control of intestinal parasites in rural Bangladesh

The study examined the cost effectiveness of 4 different regimens in reducing the prevalence and intensity of infection of Ascaris lumbricoides, Trichuris trichiura, and hookworm over an 18-mo period in randomized community samples of children aged 2-8 yr living in rural Bangladesh. The household was the unit of randomization in each community. The 4 regimens were (1) only chemotherapy to all household members at the commencement of the study (i.e., at an interval of 18 mo), (2) same as group (1) and regular health education throughout the study period, (3) chemotherapy to all household members at the commencement of the study and subsequent chemotherapy to all children at intervals of 6 mo, and (4) same as group 3 with the addition of regular health education throughout the study period. Health education (through home and school visits and focus group discussions) was aimed at increasing awareness of worm transmission and the disabilities caused by intestinal helminths. Simple ways of improving personal hygiene and sanitation through hand washing, nail trimming, wearing of shoes, and use of a latrine and clean water supplies were encouraged. Because albendazole is a broad spectrum anthelmintic, the cost effectiveness of the 4 interventions were compared by the weighted percentage reduction in prevalence and the weighted percentage reduction in intensities of infection as measured by geometric mean egg loads of all 3 worms combined. The most cost-effective strategy was the single albendazole mass chemotherapy at an interval of 18 mo. The 2 regimens involving health education were the least cost effective.

Neuroleukin mediated differentiation induction of myelogenous leukemia cells

Leukemia cells enriched from peripheral blood of a patient with myelogenous leukemia were induced to differentiate with a purified T cell lymphokine neuroleukin. With sufficient neuroleukin concentrations, cells with macrophage-like morphology were identified among the developing adherent cells. After 2-5 days, approximately 38-50% of the suspension cells became macrophage-like and acquired CD21, alpha-naphthyl acetate reactivity and immune adherence capability. The amount of these nonproliferating cells increased along with cells containing fragmented DNA. Induction with insufficient neuroleukin quantity or with patient plasma alone developed few or no mature cells, indicating differentiation to mature cells is dose-dependent. The possibility of insufficient quantity of neuroleukin in regulation of patient plasma for differentiation was discussed.

In vitro effects and clinical evaluation of a human chorionic gonadotrophin preparation in acute leukemia

Commercial human chorionic gonadotrophin (HCG) preparations decrease the tumorigenicity of human tumors in immunodeficient mice and induce apoptotic cell death in animal tumor models. Preliminary studies in humans have demonstrated tumor regression in patients with Kaposi's sarcoma given intralesional injections of HCG. To further evaluate HCG's antitumor activity we conducted in vitro and clinical evaluations of HCG in acute myeloid leukemia (AML). In HL-60 leukemic cell lines, a 20-40% inhibition of cell density was demonstrated by trypan blue exclusion method at low concentrations of an HCG preparation (2 x 10(-3)-2 x 10(-2)). Similar concentrations also resulted in a reduction in the proportion of cells in G2M phase of the cell cycle, as well as enhanced differentiation compared to control cells. Fifteen patients with advanced AML with marrow blast counts >30%, and five with marrow blast counts between 10 and 26% were given daily subcutaneous injections of HCG 2-4 IU and oral levamisole 50 mg weekly. Five patients with absolute blast counts in the blood ranging from 0 to 3500/microl and percent blasts in the marrow ranging from 16 to 81% were observed to have no progressive increase in either marrow or peripheral blast counts for 70-121 days. One patient with a pretreatment blast count of 10% in the marrow, no circulating blasts and minor cytopenias had a decrease in marrow blasts to less than 5% which has persisted at 550 days. No significant improvement from baseline levels of neutrophils, hemoglobin or platelets were observed in any nl the patients treated. Increases in apoptotic cell death were observed in over 50% of patients' cells with some demonstrating peak levels similar to experiences in patients treated with DNA-damaging chemotherapy. A decreased expression of bcl-2 was seen in the majority of patients ranging from 6 to 62%. These new observations suggest that HCG preparations may inhibit leukemic cell growth through enhancement of cell death mechanisms and could be used in judicious combinations with other approaches. The results confirm the pro-apoptotic effects of HCG preparations reported in patients with Kaposi's sarcoma. Identification of the active component of HCG preparations and further understanding of its growth modulatory action will be important in its development as a clinically useful agent.

The role of peritoneal drains in treatment of perforated necrotizing enterocolitis: recommendations from recent experience

BACKGROUND/PURPOSE

Intraperitoneal drains have been used in the treatment of perforated necrotizing enterocolitis (NEC), especially in infants less than 1,000 g, yet their role is still debated. The authors wished to examine their more recent experience in the treatment of NEC to make recommendations for operative management.

METHODS

The authors reviewed the records of all infants seen between 1989 and 1995 who had clinical and radiological evidence of NEC at the Hospital for Sick Children, Toronto, Ontario. One hundred sixty-seven infants were treated for NEC and 73 (44%) infants required surgical intervention.

RESULTS

Forty-five patients had perforated NEC; 23 were treated initially by peritoneal drainage and 22 by primary laparotomy. The 23 newborns who had peritoneal drainage were of significantly lower birth weight, and 19 (83%) of these infants required subsequent laparotomy for worsening disease. The overall mortality rate for perforated NEC was 36%.

CONCLUSION

Insertion of a peritoneal drain is still useful in resuscitating small critically ill infants with NEC; however, the majority of these infants will also require laparotomy.

Drugs Affecting Lipid Metabolism--XIII International Symposium. 30 May-3 June 1998, Florence, Italy

This meeting convened over four days in the historical city of Florence, Italy. It attracted around 2500 attendees mainly from academia and pharmaceutical companies but also included clinical cardiologists from around the world. The conference covered a wide range of topics in the field of heart disease and lipid lowering drugs in the plenary sessions, workshops, and over 300 posters. The plenary sessions and series of workshops entitled "Drugs affecting lipid metabolism" were well attended and stimulated much discussion. There was a noticeably high content of basic research in the workshops, particularly in the field of molecular biology, although clinical studies also made up a large part of the data.

Humoral immune and clinical responses to food antigens following acute diarrhoea in children

OBJECTIVE

To investigate the effect of acute watery diarrhoea in children upon humoral immune responses to food antigens and the subsequent development of food allergy.

METHODOLOGY

Serum antibodies to cows' milk, beta-lactoglobulin, alpha-lactalbumin, bovine serum albumin and ovalbumin were measured in 30 children with acute diarrhoea in the acute phase and 1 month after recovery. The children were followed for 1 year to assess the development of food allergy.

RESULTS

IgG antibeta-lactoglobulin titres for the study group increased 1 month after recovery compared to the titres during the acute phase (P = 0.02). Antibody concentration for the other antigens studied did not rise. Four children developed positive IgE antibodies to one or more of the allergens after the diarrhoeal episode, although the titres were very low. None showed evidence of allergy to cows' milk or egg during the year-long follow-up.

CONCLUSIONS

Acute diarrhoea in children resulted in increased production of IgG antibody to beta-lactoglobulin and had a priming effect for development of positive IgE antibody to cows' milk. Clinical food allergy was not observed in any of the children during the year-long follow-up.

Inhibition of antigen-induced airway hyperresponsiveness by ultralow molecular-weight heparin

Unfractionated heparin (UF-heparin) has been shown to prevent antigen-induced airway hyperresponsiveness (AHR), but it is ineffective when administered after the antigen challenge. We hypothesized that the failure of UF-heparin to modify postantigen AHR might depend on molecular weight. We therefore studied the effects of UF-heparin and three low-molecular-weight heparin fractions (medium-molecular-weight heparin [MMWH]; low-molecular-weight heparin [LMWH]; and ultralow-molecular-weight heparin [ULMWH]) on antigen-induced AHR and histamine release in bronchoalveolar lavage fluid (BALF). Specific lung resistance (SRL) was measured in 20 allergic sheep before, immediately after, and up to 2 h after challenge with Ascaris suum antigen. Airway responsiveness was expressed as the cumulative provocative dose of carbachol, in breath units, that increased SRL by 400% (PD400). PD400 was determined before and 2 h after antigen, both without and after treatment with aerosolized UF-heparin (1,000 U/kg) and various heparin fractions (0.04 mg/kg to 5 mg/kg) administered after the antigen challenge. Inhaled UF-heparin (n = 4), MMWH (n = 4), and LMWH (n = 6) failed to modify postantigen AHR when administered after the challenge. Only ULMWH (n = 6) inhibited postantigen AHR in a dose-dependent manner (percent protection ranged from 31% to 139%). In eight additional sheep, histamine in BALF was measured with a radioimmunoassay (RIA) before and after the segmental antigen challenge, without and after pretreatment with inhaled UF-heparin, LMWH, or ULMWH. Inhaled UF-heparin and LMWH inhibited antigen-induced histamine release as measured in BALF by 81% and 75%, respectively; whereas ULMWH was ineffective in this respect. We conclude that: (1) modification of antigen-induced AHR by fractionated heparins is molecular-weight dependent; and (2) only ULMWH attenuates AHR when administered after antigen challenge, via an unknown mast-cell-independent action.

Gene transfer of alpha interferon into hematopoietic stem cells

Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. IFN-alpha has been used in the management of leukemia, and gene transfer of the IFN-alpha gene into hematopoietic progenitor cells may have great potential for the treatment of chronic myelogenous leukemia (CML). Therefore, we examined the ability of adenovirus (Ad)-IFN-alpha gene construct to transfect normal bone marrow hematopoietic CD34+ stem cells and the production of IFN-alpha protein by these cells. Ad-cytomegalovirus (CMV) promoter-driven IFN-alpha at multiple doses was assessed to transfect highly purified CD34+ cells in liquid culture. Optimal transduction of CD34+ cells with the AdCMV-IFN-alpha construct was achieved using 120 plaque forming units (pfu). Flow cytometric determinations revealed that there was no significant difference in CD34+ cell viability for the 8 or 12-h transfection periods. Immunoassay of IFN-alpha produced by CD34+ cells shows that IFN-alpha levels increased several fold in transfected cells and this was not seen in CD34+ cells transfected with the heme oxygenase gene (HO-1). These in vitro data suggest that adenovirus-mediated gene transfer of IFN-alpha into hematopoietic stem cells can be achieved and that the IFN-alpha protein is produced by viable CD34 progenitor cells.

Groin complications associated with collagen plug closure of femoral arterial puncture sites in anticoagulated patients

A retrospective study was conducted to determine the frequency and nature of groin complications when the Vasoseal (Datascope Corp., NJ) hemostasis device was used on 204 occasions to enable removal of the groin sheath in anticoagulated patients. The patients had undergone balloon angioplasty (53%), coronary stenting (20%), and diagnostic angiography (27%). Complications included vascular surgery in 5% including 2 embolized collagen plugs, failure to achieve hemostasis (2%), late external bleeding (2%), purulent discharge (1.5%), a minor ooze of blood (7%), hematomas >6 cm (6%), and hematomas < or = 6 cm (7%). One or more complications occurred with 64 of 204 (30.5%) uses. Multivariate analysis identified diagnostic angiography to be associated with a reduced risk of complications [odds ratio (OR) 0.25], while stent procedure (OR 2.7) and female gender (OR 2.5) were associated with increased risk. This complication rate is similar to other reported series except for a higher rate of vascular surgery. The high incidence of anticoagulation in our study patients (94%) may explain this difference. We recommend caution and adherence to the recommended technique when the device is used in anticoagulated patients.

Mixed effects of 2,6-dithiopurine against cyclophosphamide mediated bladder and lung toxicity in mice

2,6-Dithiopurine (DTP) has been proposed as a possible chemopreventive agent because of its ability to react with electrophiles. Acrolein, an electrophilic metabolite of cyclophosphamide (CP) involved in the toxicities of this anticancer drug, can be scavenged by DTP. The present study examined the effect of DTP treatment on CP-mediated bladder and lung toxicity in male ICR mice. Mice fed a diet containing 4% DTP that were treated intraperitoneally (i.p.) with 350 mg/kg CP showed no significant bladder damage (measured as bladder blood content at 48 h) with respect to the group fed a control diet. DTP (50 and 100 mg/kg), given i.p. 0.5 and 7 h after the initial injection of CP, also prevented the bladder damage when compared with the group receiving CP alone. Surprisingly, although neither parenteral CP nor DTP alone caused any mortality at these doses, the combined treatment resulted in 67% mortality within 3 days. At 24 h after CP + DTP, blood urea nitrogen was elevated 6-fold and urine volumes decreased by 70%. Histopathological analyses revealed a diffuse myocardial degeneration and necrosis, severe granular degeneration in the liver, abundant cellularity and infiltrates in interalveolar spaces in the lung and swollen nephron epithelial cells with some necrosis. All mice survived treatment when the dose of CP was lowered to 250 and 25-75 mg/kg DTP was given i.p. 0.5 and 7 h after CP. These DTP regimens reduced the degree of CP-induced lung toxicity, measured by [3H]thymidine incorporation into lung DNA 7 days after CP, in a dose-dependent manner. DTP (75 mg/kg) also reduced CP-induced lung fibrosis estimated by lung hydroxyproline content 28 days after CP. Analyses of urine from mice given CP + DTP revealed large amounts of the metabolic product dithiouric acid, smaller amounts of the parent DTP and several smaller peaks. The major unique metabolite peak was collected and analyzed by mass spectrometry, but did not correspond to either acrolein-DTP or acrolein-dithiouric acid. Thus, either very small amounts of an acrolein adduct are generated, the adduct is broken down to an unidentified product, or the ability of DTP to prevent CP-induced lung and bladder damage is related to some other mechanism. The possibility that mercapturic acid metabolites of acrolein released the parent electrophile in the urine was not supported by the finding that probenecid did not prevent CP-induced bladder toxicity.

Effects of socioeconomic factors, psychological stress, smoking, alcohol and caffeine on preterm delivery

The relation between preterm birth and socioeconomic and psychological factors, smoking, alcohol and caffeine consumption are studied. Gestational age was determined from ultrasound and maternal dates. Adverse social circumstances are associated with preterm birth which inturn effects fetal growth.

Inhibition of allergic airway responses by inhaled low-molecular-weight heparins: molecular-weight dependence

Inhaled heparin prevents antigen-induced bronchoconstriction and inhibits anti-immunoglobulin E-mediated mast cell degranulation. We hypothesized that the antiallergic action of heparin may be molecular weight dependent. Therefore, we studied the effects of three different low-molecular-weight fractions of heparin [medium-, low-, and ultralow-molecular-weight heparin (MMWH, LMWH, ULMWH, respectively)] on the antigen-induced acute bronchoconstrictor response (ABR) and airway hyperresponsiveness (AHR) in allergic sheep. Specific lung resistance was measured in 22 sheep before and after airway challenge with Ascaris suum antigen, without and after pretreatment with inhaled fractionated heparins at doses of 0.31-5.0 mg/kg. Airway responsiveness was estimated before and 2 h postantigen as the cumulative provocating dose of carbachol in breath units that increased specific lung resistance by 400%. All fractionated heparins caused a dose-dependent inhibition of ABR and AHR. ULMWH was the most effective fraction, with the inhibitory dose causing 50% protection (ID50) against ABR of 0.5 mg/kg, whereas ID50 values of LMWH and MMWH were 1.25 and 1.8 mg/kg, respectively. ULMWH was also the most effective fraction in attenuating AHR; the ID50 values for ULMWH, LMWH, and MMWH were 0.5, 2.5, and 4.7 mg/kg, respectively. These data suggest that 1) fractionated low-molecular-weight heparins attenuate antigen-induced ABR and AHR; 2) there is an inverse relationship between the antiallergic activity of heparin fractions and molecular weight; and 3) ULMWH is the most effective fraction preventing allergic bronchoconstriction and airway hyperresponsiveness.

Gastrointestinal allergy to food: a review

Gastrointestinal food allergy still poses a challenge to the clinician because of its variable symptomatology and lack of reliable diagnostic tests. Its prevalence is estimated at 2 approximately 5%, higher in children than in older age-groups. Allergy to food usually diminishes with advancing age. Although a wide variety of foods can cause allergic reactions, cow's milk is the most common cause of food allergy in infants and young children. Depending upon the speed of onset of symptoms, immediate and delayed types of food allergy have been described. Gastrointestinal symptoms in food allergy have been explained by alterations in transport across the intestinal wall (increased secretory and/or decreased absorptive functions), increased permeability, and motility of the intestine. The exact pathogenesis of food allergy is still not clear. However, immediate type of food allergy is believed to be mediated by type I hypersensitivity reaction, involving mast cells and food-specific IgE antibodies. The diagnosis of food allergy is based upon a favorable response to an elimination diet and a response to a challenge with the suspected food. The condition is treated by eliminating the allergenic food from diet for as long as 9-12 months in case of cow's milk allergy. While exclusive breast-feeding for the initial four months or more reduces the chances of development of food allergy, the role of diet restrictions in the mother in reducing the incidence of food allergy in the infant is controversial. Data on food allergy from developing countries are limited. This may be due to lack of diagnosis or less attention given to the condition relative to other diseases including infectious diarrheas and acute respiratory infections. The role of cow's milk allergy in the pathogenesis of persistent diarrhoea, a major problem in the developing world, remains speculative. Frequent intestinal infections and reduced secretory IgA, which are associated with malnutrition, alter intestinal permeability and result in an increased uptake of food antigens. The increased antigenic load combined with factors such as an atopic predisposition may initiate an abnormal mucosal immune response resulting in chronic enteropathy.

Effect of Holding Time on Damage State in a Thermal Barrier Coating

Spallation is a major failure condition experienced by thermal barrier coatings (TBCs) subjected to thermal and mechanical loads. Although evidence of spallation is substantiated and mechanistic models to describe the failure condition is prevalent in literature, the progressive nature of damage evolution leading to spallation has not been addressed adequately. In this study, the effect of holding time on damage evolution in partially stabilized zirconia TBC on Nickel-based single crystal superalloy, Rene N5, was studied. Button specimens with Electron Beam - Physical Vapor Deposition (EB-PVD) TBC coating were thermally cycled. The bond coat was PtAl. Two different thermal cycle profiles were used to assess damage development. Damage state was tracked using microscopy and thermal wave imaging technique on samples subjected to a series of thermal cycles. It was found that if the sum of hold times at the same peak temperature are kept constant for two different thermal cycles profiles, similar damage states can be obtained.

Adenovirus mediated alpha interferon (IFN-alpha) gene transfer into CD34+ cells and CML mononuclear cells

Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. Interferon-alpha (IFN-alpha) has been used in the management of leukemia but its diverse adverse activities with multiple potential side effects, possibly unrelated to therapeutic targets, may negatively influence the ability of IFN-alpha to treat this disorder. Therefore, we examined the ability of adenovirus (Ad)-IFN-alpha gene construct to transfect normal (CD34+ cells) and chronic myelogenous leukemia (CML) bone marrow mononuclear cells (BMMNC) and the transient overexpression of IFN-alpha in these cells. Ad-cytomegalovirus promoter driven IFN-alpha (AdCMV-IFN-alpha) at multiple doses was assessed to transfect highly purified CD34+ cells in liquid culture, and optimal transduction of CD34+ cells was achieved using 120 plaque forming units. Flow cytometric determinations revealed that there was no significant difference in cell viability for the 4 h or 24 h transfection periods. Immunoassay of IFN-alpha produced by CD34+ cells shows that IFN-alpha levels increased several fold in transfected cells. Transient expression of the IFN-alpha gene did not suppress proliferation of CD34+ progenitors as indicated by BFU-E or colony forming units-granulocyte-macrophage (CFU-GM) growth. Reverse transcriptase/polymerase chain reaction analysis of RNA from CD34+ harvested CFU-GM progenitor cells demonstrated transient IFN-alpha mRNA expression. Similarly, CML BMMNC were transfected with AdCMV-IFN-alpha under similar conditions as described for CD34+ cells. BMMNC cells exposed to adenovirus for 24 h and 48 h were found to express IFN-alpha at a substantial level. This in vitro data suggest that Ad-mediated gene transfer of IFN-alpha into hematopoietic stem cells can be achieved and that the IFN-alpha gene can be translated into its specific mRNA in CD34 progenitor cells.

Value of clinical features in the diagnosis of enteric fever

There is no objective data on the value of individual clinical symptoms or signs in the diagnosis of enteric fever in a febrile patient. The purpose of the study was to assess the value of some clinical and simple laboratory features in the diagnosis of enteric fever. One hundred & six patients with microbiologically confirmed enteric fever and 170 patients with other established febrile illnesses were included in the evaluation. History of stepladder pattern of rise of temperature, loose motions, relative bradycardia and coated tongue proved to be powerful markers of enteric fever with high specificity (100%, 94.71%, 94.71%, 94.12% respectively), positive and negative predictive values. Headache, hepatomegaly and splenomegaly were moderately powerful. ESR and WBC count appeared to have little value in the diagnosis of enteric fever. Pattern of onset and loose motions did not discriminate between typhoid and paratyphoid fever. Most of these patients had illness persisting beyond one week by which viral infections and infectious enterocolitides were largely excluded. Elucidation of power of these markers in distinguishing enteric fever from other febrile illnesses with the help of better designed prospective studies would lessen our dependence on expensive and time consuming laboratory investigations.

An intralaboratory quality control program for quantitation of CD34+ cells by flow cytometry

This study was undertaken to develop a quality control protocol to monitor instrument, operator, and CD34 assay performance. A dual level control system was established by cryopreserving aliquots of cells from peripheral blood progenitor cell (PBPC) collections exhibiting different percentages of CD34+ cells. Twenty-five samples from each control specimen were assayed to establish a control range (mean +/- 2 SD). Levey-Jennings graphs were prepared for each control specimen to plot multiple measurements of CD34%. No significant differences were observed between fresh or cryopreserved PBPC aliquots in terms of light scatter properties or CD34 antigen density within the gated cell population. Cryopreserved PBPC samples are ideal for serving as a positive methodology control for daily CD34 analysis. Furthermore, such a system can help identify problems with assay reagents, sample preparation technique, or incorrect data analysis.

Immune response to food antigens: kinetics of food-specific antibodies in the normal population

The role of food-specific antibodies in the pathogenesis of food allergy is controversial. The first step in solving this controversy may be the assessment of antibody response to food antigens in the normal population. Most of the existing data in this field come from studies that used assays of different standards. This study investigated food-specific antibodies in the normal population using standardized assays. Normal levels of antibody titers were also derived for use as reference. Two hundred and eight individuals from different age groups participated. Immunoglobulin G (IgG) antibodies to cow's milk and its component proteins, and to hen's egg ovalbumin, IgA and IgM antibodies to beta-lactoglobulin and ovalbumin were measured by enzyme-linked immunosorbent assay. The sepharose-radioallergosorbent test was used to measure IgE antibodies to cow's milk and ovalbumin. Titers of IgG antibodies to cow's milk and its component proteins revealed an age-related trend, peaking in the 5 months-1 year age group and then decreased to negligible values in adults. A similar trend was observed with IgG anti-ovalbumin antibodies. Temporal association was less evident for antibodies of other classes. Only six subjects had positive IgE antibodies to cow's milk, while none had positive IgE anti-ovalbumin antibody. The prevalences of IgG antibodies to cow's milk, its component proteins, and ovalbumin are influenced by age and feeding habits. Cross-reactivity to related food antigens is common. The presence of IgE antibodies to food antigens is not a physiological phenomenon.

Inhibition of antigen-induced acute bronchoconstriction, airway hyperresponsiveness, and mast cell degranulation by a nonanticoagulant heparin: comparison with a low molecular weight heparin

Inhaled heparin prevents antigen-induced bronchoconstriction and inhibits anti-IgE-mediated mast-cell degranulation. We hypothesized that the antiallergic action of heparin may be dependent on molecular weight and related to its nonanticoagulant properties. Therefore, in the present investigation we studied the effects of a nonanticoagulant fraction of heparin (LA-heparin) on antigen-induced bronchoconstriction, airway hyperresponsiveness (AHR), and mast-cell degranulation, and compared its antiallergic activity with that of a low molecular weight heparin (LMW-heparin, fragmin). Specific lung resistance (SRL) was measured in 15 sheep before, immediately after, and serially for as long as 2 h after airway challenge with Ascaris suum antigen, without and after pretreatment with inhaled fractionated heparins at doses of 2.5 and 5 mg/kg. Airway responsiveness was estimated before, and 2 h after antigen as the cumulative provocating dose (PD400) of carbachol in breath units, which increased SRL by 400% (one breath unit was defined as one breath of 1% carbachol solution). LA-heparin caused a dose-dependent inhibition of antigen-induced bronchoconstriction, and a 5-mg/kg nebulized dose caused a 67% inhibition of allergic bronchoconstriction, whereas a 2.5-mg/kg dose was ineffective (20% inhibition). Inhaled fragmin was more potent than LA-heparin, as shown by 84% (2.5 mg/kg) and 82% (5 mg/kg) inhibition of allergic bronchoconstriction. Fragmin (5 mg/kg) also attenuated the postantigen AHR, whereas LA-heparin was ineffective. In vitro, preincubation with both LA-heparin and fragmin inhibited the anti-IgE-induced degranulation of rat peritoneal mast-cells in a dose-dependent fashion. LA-heparin was fourfold more potent than fragmin, with IC50 of 80 and 320 microg/ml, respectively. These data suggest that: (1) fractionated heparins attenuate antigen-induced acute bronchoconstriction, (2) nonanticoagulant fractions mediate the antiallergic activity of inhaled heparin, and (3) antiallergic activity of nonanticoagulant heparin and LMW-heparin may be related to prevention of mast-cell degranulation.

Granulocyte-macrophage colony-stimulating factor/interleukin-3 fusion protein versus granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for non-Hodgkin's lymphoma: results of a randomized double-blind trial

PURPOSE

A phase III trial to compare PIXY321 with granulocyte-macrophage colony-stimulating factor (GM-CSF) following high-dose therapy and autologous bone marrow transplant (ABMT) was conducted to evaluate the time to hematopoietic recovery.

PATIENTS AND METHODS

One hundred seventy-seven patients with non-Hodgkin's lymphoma (NHL) receiving ABMT were randomized to receive either PIXY321 750 micrograms/m2/d divided into two subcutaneous (SC) doses or GM-CSF 250 micrograms/m2/d as a 2-hour intravenous (IV) infusion starting on day 0 post-ABMT for a maximum of 28 days.

RESULTS

The median time to reach an absolute neutrophil count (ANC) > or = 500/microL in the PIXY321 group was 17 days versus 19 days in the GM-CSF group (P = .07) and the median time to reach platelet transfusion independence in the PIXY321 group was 25 days versus 23 days in the GM-CSF group (P = .30). The toxicity profiles of the two agents appeared to be equivalent with the exception of more patients in the PIXY321 group with a rash (64%) compared with the GM-CSF group (48%) (P = .028). A logistic regression model identified the use of a non-total-body irradiation (TBI) regimen and/or receipt of unpurged marrow and a body-surface area greater than 2.0 m2 as predictive of faster neutrophil engraftment, and those three factors, as well as the receipt of < or = two prior chemotherapy regimens as predictive for rapid platelet engraftment.

CONCLUSION

There was a trend toward a slight improvement in neutrophil engraftment post-ABMT with the PIXY321 administered by an SC route compared with GM-CSF administered by an IV route. However, no differences could be identified between the two agents with respect to the time to platelet transfusion independence. Patient, regimen, and graft characteristics were most predictive of the engraftment tempo.

A randomized trial of high- vs standard-dose mitoxantrone with cytarabine in elderly patients with acute myeloid leukemia

To evaluate the efficacy and tolerability of a high-dose mitoxantrone-based induction regimen without consolidation therapy in patients over age 60 with newly diagnosed acute myeloid leukemia (AML), 54 patients aged 60-83 were randomized to receive mitoxantrone, either 80 mg/m2 on day 2, or 12 mg/m2 on days 1-3 in addition to cytarabine, 3 g/m2 on days 1-5. Significant toxicity included mucositis, diarrhea, transient hyperbilirubinemia and cardiac events. No difference in toxicity was observed between the two dosage regimens. Overall, 27 patients achieved a complete remission (CR), 16/28 CR in the high-dose and 11/25 in the lower-dose group. Induction death occurred in 11 patients, three in the high-dose and eight in the low-dose arm. Actuarial median survival was 6 months for the low-dose and 9 months for the high-dose group, and the respective relapse-free survival is 3 and 5 months. The observed differences in outcome were not statistically significant. patients in both arms of this trial, who received no consolidation, appear to have response and survival rates equivalent to those of standard-dose induction with repetitive consolidation. This approach might offer elderly patients equivalent outcome with fewer days of treatment, presumably enhancing quality of life.