Acute bilineal leukemia: a rare disease with poor outcome

Most cases of acute leukemia can be assigned to the myeloid, B or T lineage. In a few cases, definitive assignment cannot be achieved because blasts express antigens of more than one lineage. A subset of these, referred to as acute bilineal leukemias (aBLLs), is characterized by the presence of more than one population of blasts, each comprising a single lineage. We identified 19 cases of aBLL, including 10 mixed T and myeloid (T-My) and nine mixed B and myeloid (B-My); no mixed B and T cases were identified. Cytogenetic data were available for 16 patients. Three of seven patients with B-My had a t(9;22)(q34q11.2), two had 11q23 translocations and one had del(9). Two of nine patients with T-My had 2p13 translocations; five had other unrelated abnormalities. Of 16 patients with outcome data, only six achieved complete remission and only two remain free of disease 2.5 and 4.5 years after chemotherapy or stem cell transplantation. aBLL is a rare disease that combines B or T and myeloid blasts. Cytogenetic abnormalities of t(9;22) and 11q23 are common in, and may be restricted to, B-My cases, while T-My cases have frequent but generally non-recurring abnormalities. Both types of aBLL are associated with poor outcome.

Monoclonal nicotine-specific antibodies reduce nicotine distribution to brain in rats: dose- and affinity-response relationships

Vaccination against nicotine is being studied as a potential treatment for nicotine dependence. Some of the limitations of vaccination, such as variability in antibody titer and affinity, might be overcome by instead using passive immunization with nicotine-specific monoclonal antibodies. The effects of antibodies on nicotine distribution to brain were studied using nicotine-specific monoclonal antibodies (NICmAbs) with K(d) values ranging from 60 to 250 nM and a high-affinity polyclonal rabbit antiserum (K(d) = 1.6 nM). Pretreatment with NICmAbs substantially increased the binding of nicotine in serum after a single nicotine dose, reduced the unbound nicotine concentration in serum, and reduced the distribution of nicotine to brain. Efficacy was directly related to antibody affinity for nicotine. Efficacy of the highest affinity NICmAb, NICmAb311, was dose-related, with the highest dose reducing nicotine distribution to brain by 78%. NICmAb311 decreased nicotine clearance by 90% and prolonged the terminal half-life of nicotine by 120%. At equivalent doses, NICmAb311 was less effective than the higher affinity rabbit antiserum but comparable efficacy could be achieved by increasing the NICmAb311 dose. These data suggest that passive immunization with nicotine-specific monoclonal antibodies substantially alters nicotine pharmacokinetics in a manner similar to that previously reported for vaccination against nicotine. Antibody efficacy is a function of both dose and affinity for nicotine.

Infertility rates following POMB/ACE chemotherapy for male and female germ cell tumours - a retrospective long-term follow-up study

The risk of chemotherapy-induced infertility in male and female germ cell tumour (GCT) survivors is unclear, but may correlate with cisplatin dose. Here, we examine a large series of GCT patients for the effect of chemotherapy on those attempting to have children. Our GCT database was screened for nonseminomatous GCT patients who had (1) received POMB/ACE chemotherapy (cisplatin, vincristine, methotrexate, bleomycin alternating with actinomycin D, cyclophosphamide and etoposide) and (2) stage I male GCT patients who were untreated between 1977 and 1996. Fertility was assessed by questionnaire and medical records. A total of 64 of 153 treated and 35 of 115 untreated men attempted to have children. In all, 28% (18 out of 64) receiving POMB/ACE were unsuccessful. Radiotherapy (six), atrophic remaining testis (one) or prior infertility (three) were implicated in 10 cases, so chemotherapy-induced infertility may have occurred in only 11% (eight out of 64). Strikingly, 26% (nine out of 35) of untreated stage I patients also failed to have children (three had radiotherapy, three prior infertility). Moreover, in treated men, no association was seen between cisplatin dose and infertility. In contrast, radiotherapy significantly increased male infertility (P=0.001). Of 28 treated women who attempted to have children, 25% (seven out of 28) were unsuccessful. One previously had infertility and one subsequently had successful IVF so chemotherapy-induced infertility potentially occurred in only 18% (five out of 28) and was not related to cisplatin dose. In conclusion, the risk of chemotherapy-induced infertility is low in both male and female GCT patients and does not clearly correlate with the cumulative cisplatin dose.

Generation of a recombinant Fab antibody reactive with the Alzheimer's disease-related Abeta peptide

A recombinant Fab antibody, designated 1E8-4b, which reacts with the Alzheimer's disease (AD)-related Abeta peptides, Abeta[1-40], Abeta[1-42] and Abeta[1-43] has been developed. The 1E8-4b Fab was constructed by cloning the V(H)C(H1) and V(L)C(L) domains from the parent hybridoma 1E8 antibody, reported previously to recognize these Abeta peptides. Briefly, a C-terminal Flag tag sequence was incorporated into this construct, which was ligated into the vector pHFA2 and expressed in Escherichia coli. Following purification on an M2 anti-Flag affinity column, the 1E8-4b recombinant Fab antibody was shown to bind plaques within sections of brain tissue from CERAD-defined AD patients by immunohistochemistry. ELISA, epitope mapping and immunoblotting confirmed the recognition of the Abeta1-40/42/43] peptides by the 1E8-4b Fab. The 1E8-4b Fab did not recognize APP695 or APP770 which contain the Abeta sequence. The Abeta specificity of the recombinant 1E8-4b Fab antibody was identical to the parent 1E8 monoclonal antibody.

Informatics for Peru in the new millennium

INTRODUCTION

As efforts continue to narrow the digital divide between the North and South, a new biomedical and health informatics training effort has been launched in Peru. This report describes the first year of work on this collaborative effort between the University of Washington (Seattle) Universidad Peruana Cayetano Heredia and Universidad Nacional de San Marcos (Peru)

OBJECTIVES

To describe activities in the first year of a new International Research and Training Program in Biomedical and Health Informatics.

METHODS

Descriptive analysis of key activities including an assessment of electronic environment through observation and survey, an in country short course with quantitative evaluation, and first round of recruitment of Peruvian scholars for long-term training in Seattle.

RESULTS

A two-week short course on informatics was held in the country. Participants' success in learning was demonstrated through pretest/posttest. A systematic assessment of electronic environment in Peru was carried out and two scholars for long-term training were enrolled at the University of Washington, Seattle.

DISCUSSION

Initial activity in the collaborative training effort has been high. Of particular importance in this environment is orchestration of efforts among interested parties with similar goals in Peru, and integration of informatics skills into ongoing large-scale research projects in country.

The effect of early pregnancy following chemotherapy on disease relapse and foetal outcome in women treated for gestational trophoblastic tumours

Little literature exists on the safety of early pregnancy following chemotherapy. Here we assess the rate of relapse and foetal outcome in women who have completed single and multi-agent chemotherapy for gestational trophoblastic tumours. The records of 1532 patients treated for persistent gestational trophoblastic tumours at Charing Cross Hospital between 1969 and 1998 were reviewed. Patients were defined as receiving single agent or multi-agent treatment. Relapse rates and foetal outcome were reviewed in the 230 patients who became pregnant within 12 months of completing chemotherapy. In the single agent group 153 (22%) of 691 patients conceived early. Three subsequently relapsed. In the multi-agent group, 77 (10%) of 779 patients conceived early, two then relapsed. Relapse rates were 2% (3 out of 153) and 2.5% (2 out of 77) for each group compared to 5% and 5.6% in the comparative non-pregnant groups. Outcomes of 230 early pregnancies: 164 (71%) delivered at full term, 35 (15%) terminations, 26 (11%) spontaneous abortions, three (1.3%) new hydatidiform moles and two (1%) stillbirths. Early pregnancies were more common in the single agent group (P<0.001), but spontaneous miscarriages and terminations were more likely to occur in the multi-agent group (P=0.04 and 0.03, respectively). Of the full-term pregnancies, three (1.8%) babies were born with congenital abnormalities. Patients in either group who conceive within 12 months of completing chemotherapy are not at increased risk of relapse. Though, we still advise avoiding pregnancy within 12 months of completing chemotherapy, those that do conceive can be reassured of a likely favourable outcome. DOI: 10.1038/sj/bjc/6600041 www.bjcancer.comCopyright 2002 The Cancer Research Campaign

Oral health promotion evaluation--time for development

Increasing emphasis is now being placed upon the evaluation of health service interventions to demonstrate their effects. A series of effectiveness reviews of the oral health education and promotion literature has demonstrated that many of these interventions are poorly and inadequately evaluated. It is therefore difficult to determine the effectiveness of many interventions. Based upon developments from the field of health promotion research this paper explores options for improving the quality of oral health promotion evaluation. It is essential that the methods and measures used in the evaluation of oral health promotion are appropriate to the intervention. For many oral health promotion interventions clinical measures and methods of evaluation may not be appropriate. This paper outlines an evaluation framework which can be used to assess the range of effects of oral health promotion programmes. Improving the quality of oral health promotion evaluation is a shared responsibility between researchers and those involved in the provision of programmes. The provision of adequate resources and training are essential requirements for this to be successfully achieved.

Biomedical and Health Informatics Research and Education at the University of Washington

Although an extensive medical informatics research program as well as courses and training experiences in biomedical informatics have existed at the University of Washington (UW) for many years, a formal home did not exist until 1997 when the Division of Biomedical Informatics was created in the Department of Medical Education, School of Medicine. Since that time the expansion of the research, service and teaching programs has been rapid with a key milestone being a university commitment to provide funding, space and faculty to support the development of a new graduate program in Biomedical and Health Informatics.

Hallmarks of the biomedical and health informatics program at the University of Washington include:

- Strong shared belief that informatics research can contribute to the improvement of healthcare and health;

- Large, multidisciplinary faculty including faculty from computer science, library and information science as well as the health sciences schools (dentistry, medicine, nursing, pharmacy, and public health and community medicine);

- Comprehensive research and development partnership with the University of Washington Medical Centers information systems group and the UW Primary Care Network to move research from the laboratory to operational clinical systems;

- Extensive and diverse regional setting in which to study information needs and develop informatics solutions in primary care settings;

- Lack of barriers to interdisciplinary research and teaching.

The intact retroviral Env glycoprotein of human foamy virus is a trimer

Electron microscopy of negatively stained human foamy virus particles provides direct evidence for the trimeric nature of intact Env surface glycoproteins. Three-dimensional image reconstruction reveals that the Env trimer is a tapering spike 14 nm in length. The spikes were often arranged in hexagonal rings which shared adjacent Env trimers.

A conformational switch controlling HIV-1 morphogenesis

Assembly of infectious human immunodeficiency virus type 1 (HIV-1) proceeds in two steps. Initially, an immature virus with a spherical capsid shell consisting of uncleaved Gag polyproteins is formed. Extracellular proteolytic maturation causes rearrangement of the inner virion structure, leading to the conical capsid of the infectious virus. Using an in vitro assembly system, we show that the same HIV-1 Gag-derived protein can form spherical particles, virtually indistinguishable from immature HIV-1 capsids, as well as tubular or conical particles, resembling the mature core. The assembly phenotype could be correlated with differential binding of the protein to monoclonal antibodies recognizing epitopes in the HIV-1 capsid protein (CA), suggesting distinct conformations of this domain. Only tubular and conical particles were observed when the protein lacked spacer peptide SP1 at the C-terminus of CA, indicating that SP1 may act as a molecular switch, whose presence determines spherical capsid formation, while its cleavage leads to maturation.

Biomdecial and Health Informatics Research and Education at the University of Washington

Although an extensive medical informatics research program as well as courses and training experiences in biomedical informatics have existed at the University of Washington (UW) for many years, a formal home did not exist until 1997 when the Division of Biomedical Informatics was created in the Department of Medical Education, School of Medicine. Since that time the expansion of the research, service and teaching programs has been rapid with a key milestone being a university commitment to provide funding, space and faculty to support the development of a new graduate program in Biomedical and Health Informatics. Hallmarks of the biomedical and health informatics program at the University of Washington include: - Strong shared belief that informatics research can contribute to the improvement of healthcare and health; - Large, multidisciplinary faculty including faculty from computer science, library and information science as well as the health sciences schools (dentistry, medicine, nursing, pharmacy, and public health and community medicine); - Comprehensive research and development partnership with the University of Washington Medical Centers information systems group and the UW Primary Care Network to move research from the laboratory to operational clinical systems; - Extensive and diverse regional setting in which to study information needs and develop informatics solutions in primary care settings; - Lack of barriers to interdisciplinary research and teaching.

Allergic reactions to 6-mercaptopurine during treatment of inflammatory bowel disease

Hypersensitivity reactions to 6-mercaptopurine (6-MP) or azathioprine occur during the treatment of inflammatory bowel disease (IBD), raising significant diagnostic and therapeutic challenges. Charts of 591 patient with IBD treated with 6-MP in a single center were retrospectively reviewed. All allergic reactions were recorded along with results of rechallenge, desensitization, and subsequent course of IBD. Sixteen (2.7%) allergic reactions to 6-MP were noted, with fever being the most common (14 cases). Nine of these were rechallenged with 6-MP with recurrence of the same symptoms. Azathioprine was tried in six patients and in five the same symptoms recurred. Four patients underwent successful desensitization to either 6-MP or azathioprine; all four plus another patient who tolerated direct switch to azathioprine entered long-term remission. Among the remaining 11, 5 required surgery, 2 are well on methotrexate, and 4 have chronic symptoms while being treated with other medications. If an allergic reaction to 6-MP occurs during the treatment of IBD, direct switching to azathioprine is probably not justified. Instead, desensitization to either 6-MP or azathioprine should be attempted. Patients who can tolerate these medications after previous allergic reactions have improved outcomes compared with patients who resort to other forms of treatment.

Epitopic overload at the site of injection may result in suppression of the immune response to combined capsular polysaccharide conjugate vaccines

Capsular polysaccharide (CP) conjugate vaccines targeting a variety of bacterial infections are currently under development and clinical evaluation. The inclusion of multiple CP serotypes combined in a single injection is an important maneuver being evaluated. The combination of CP conjugate vaccines into a single multivalent injection may result in competition among the different components and adversely affect the immunogenicity of any individual conjugate. We observed a reduction of 30-90% in antibody responses to several serotypes in mice when immunogenicity of a 12-valent Escherichia coli (E. coli) lipopolysaccharide (LPS) conjugate vaccine was compared to the immunogenicity of each monovalent vaccine evaluated separately. A reduction of 30% was observed in the Staphylococcus aureus (S. aureus) type 8 CP antibodies when a type 8-rEPA conjugate was combined with a type 5-rEPA conjugate. S. aureus types 5 and 8-rEPA conjugates were combined with 100 micrograms of either rEPA (homologous) or diphtheria toxoid (DT) (heterologous) carrier proteins, and evaluated in rEPA or DT primed mice. The addition of the homologous protein resulted in a 64% reduction in type 5 CP antibodies. The heterologous protein did not affect the immunogenicity of the type 5. We postulate that the free protein competed with the conjugate and recruited most of the rEPA primed T cells. In the case of the DT conjugates, the DT targeted different populations of the T cells, thus interference was not observed. These data suggested that the epitopic load rather than the antigenic load at the site of injection caused reduced immunogenicity of the conjugates. We theorize that individual components of multivalent CP vaccines conjugated to the same carrier proteins would compete for a limited number of specific carrier protein primed T cells. This would result in one or more components being unavailable in eliciting a sufficient immune response. The use of multiple carrier proteins should be considered as an approach to reduce interference when multivalent conjugate vaccines are to be formulated into a single injection.

Biogeographic origins of goannas (Varanidae): a molecular perspective

This project aims to clarify the phylogenetic relationships among the extant species of Varanus in order to elucidate the origins of Varanidae, using DNA sequences. Results obtained for a minimum of 662 nucleotides of 12S rRNA sequence data from each of 21 extant species of Varanus indicate that the Australian varanids form a single monophyletic clade and also suggest that within the Australian varanids, members of the subgenus Odatria (pygmy monitors) may from a clade separate from those in the subgenus Varanus (large monitors). The Asian species appear to be sister taxa to the Australian species, while the two African species investigated were most divergent, suggesting that the Varanidae are not Gondwanic in origin. Hypothesis testing analyses were performed and involved constraining the 12S sequence data according to previously described topologies and testing the difference using parametric and nonparametric statistics. The phylogeny generated using 12S sequence data was statistically different from previously described morphological trees, while there was some support for topologies based on chomosomal and immunological datasets. Overall, our results suggest that the Australian species may be derived from an Asian source and are, therefore, in agreement with the hypothesis based on the fossil record suggesting that Varanidae may be Asian in origin.