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Abstract Background Lithium is a benchmark treatment for bipolar illness in adults. However, there has been relatively little methodologically stringent research regarding the use of lithium in youth suffering from bipolarity. Methods Under the auspices of the Best Pharmaceuticals for Children Act (BPCA), a Written Request (WR) pertaining to the study of lithium in pediatric mania was issued by the United States Food and Drug Administration (FDA) to the National Institute of Child Health and Human Development (NICHD) in 2004. Accordingly, the NICHD issued a Request for Proposals (RFP) soliciting submissions to pursue this research. Subsequently, the NICHD awarded a contract to a group of investigators in order to conduct these studies. Results The Collaborative Lithium Trials (CoLT) investigators, the BPCA-Coordinating Center, and the NICHD developed protocols to provide data that will: (1) establish evidence-based dosing strategies for lithium; (2) characterize the pharmacokinetics and biodisposition of lithium; (3) examine the acute efficacy of lithium in pediatric bipolarity; (4) investigate the long-term effectiveness of lithium treatment; and (5) characterize the short- and long-term safety of lithium. By undertaking two multi-phase trials rather than multiple single-phase studies (as was described in the WR), the feasibility of the research to be undertaken was enhanced while ensuring all the data outlined in the WR would be obtained. The first study consists of: (1) an 8-week open-label, randomized, escalating dose Pharmacokinetic Phase; (2) a 16-week Long-Term Effectiveness Phase; (3) a 28-week double-blind Discontinuation Phase; and (4) an 8-week open-label Restabilization Phase. The second study consists of: (1) an 8-week, double-blind, parallel-group, placebo-controlled Efficacy Phase; (2) an open-label Long-Term Effectiveness lasting either 16 or 24 weeks (depending upon blinded treatment assignment during the Efficacy Phase); (3) a 28-week double-blind Discontinuation Phase; and (4) an 8-week open-label Restabilization Phase. In December of 2006, enrollment into the first of these studies began across seven sites. Conclusion These innovative studies will not only provide data to inform the labeling of lithium in children and adolescents with bipolar disorder, but will also enhance clinical decision-making regarding the use of lithium treatment in pediatric bipolar illness. Trial Registration NCT00442039

Time-course microarray experiments are capable of capturing dynamic gene expression profiles. It is important to study how these dynamic profiles depend on the multiple factors that characterize the experimental condition under which the time course is observed. Analytic methods are needed to simultaneously handle the time course and factorial structure in the data. We developed a method to evaluate factor effects by pooling information across the time course while accounting for multiple testing and nonnormality of the microarray data. The method effectively extracts gene-specific response features and models their dependency on the experimental factors. Both longitudinal and cross-sectional time-course data can be handled by our approach. The method was used to analyze the impact of age on the temporal gene response to burn injury in a large-scale clinical study. Our analysis reveals that 21% of the genes responsive to burn are age-specific, among which expressions of mitochondria and immunoglobulin genes are differentially perturbed in pediatric and adult patients by burn injury. These new findings in the body's response to burn injury between children and adults support further investigations of therapeutic options targeting specific age groups. The methodology proposed here has been implemented in R package "TANOVA" and submitted to the Comprehensive R Archive Network at http://www.r-project.org/. It is also available for download at http://gluegrant1.stanford.edu/TANOVA/.

Background: Lithium is a benchmark treatment for bipolar illness in adults. However, there has been relatively little methodologically stringent research regarding the use of lithium in youth suffering from bipolarity., Methods: Under the auspices of the Best Pharmaceuticals for Children Act (BPCA), a Written Request (WR) pertaining to the study of lithium in pediatric mania was issued by the United States Food and Drug Administration (FDA) to the National Institute of Child Health and Human Development (NICHD) in 2004. Accordingly, the NICHD issued a Request for Proposals (RFP) soliciting submissions to pursue this research. Subsequently, the NICHD awarded a contract to a group of investigators in order to conduct these studies., Results: The Collaborative Lithium Trials (CoLT) investigators, the BPCA-Coordinating Center, and the NICHD developed protocols to provide data that will: (1) establish evidence-based dosing strategies for lithium; (2) characterize the pharmacokinetics and biodisposition of lithium; (3) examine the acute efficacy of lithium in pediatric bipolarity; (4) investigate the long-term effectiveness of lithium treatment; and (5) characterize the short- and long-term safety of lithium. By undertaking two multi-phase trials rather than multiple single-phase studies (as was described in the WR), the feasibility of the research to be undertaken was enhanced while ensuring all the data outlined in the WR would be obtained. The first study consists of: (1) an 8-week open-label, randomized, escalating dose Pharmacokinetic Phase; (2) a 16-week Long-Term Effectiveness Phase; (3) a 28-week double-blind Discontinuation Phase; and (4) an 8-week open-label Restabilization Phase. The second study consists of: (1) an 8-week, double-blind, parallel-group, placebo-controlled Efficacy Phase; (2) an open-label Long-Term Effectiveness lasting either 16 or 24 weeks (depending upon blinded treatment assignment during the Efficacy Phase); (3) a 28-week double-blind Discontinuation Phase; and (4) an 8-week open-label Restabilization Phase. In December of 2006, enrollment into the first of these studies began across seven sites., Conclusion: These innovative studies will not only provide data to inform the labeling of lithium in children and adolescents with bipolar disorder, but will also enhance clinical decision-making regarding the use of lithium treatment in pediatric bipolar illness., Trial Registration: NCT00442039.

We hypothesized that broad-scale expression profiling would provide insight into the regulatory pathways that control gene expression in response to stress and potentially identify novel heat-responsive genes. HEp2 cells, a human malignant epithelial cell line, were heated at 37 degrees C to 43 degrees C for 60 min to gauge the heat shock response, using as a proxy inducible Hsp70 quantified by Western blot analysis. Based on these results, microarray experiments were conducted at 37 degrees C, 40 degrees C, 41 degrees C, 42 degrees C, and 43 degrees C. Using linear modeling, we compared the sets of microarrays at 40 degrees C, 41 degrees C, 42 degrees C, and 43 degrees C with the 37 degrees C baseline temperature and took the union of the genes exhibiting differential gene expression signal to create two sets of "heat shock response" genes, each set reflecting either increased or decreased RNA abundance. Leveraging human and mouse orthologous alignments, we used the two lists of coexpressed genes to predict transcription factor binding sites in silico, including those for heat shock factor (HSF) 1 and HSF2 transcription factors. We discovered HSF1 and HSF2 binding sites in 15 genes not previously associated with the heat shock response. We conclude that microarray experiments coupled with upstream promoter analysis can be used to identify novel genes that respond to heat shock. Additional experiments are required to validate these putative heat shock proteins and facilitate a deeper understanding of the mechanisms involved during the stress response.

The tilted (tlt) mouse carries a recessive mutation causing vestibular dysfunction. The defect in tlt homozygous mice is limited to the utricle and saccule of the inner ear, which completely lack otoconia. Genetic mapping of tlt placed it in a region orthologous with human 4p16.3-p15 that contains two loci, DFNA6 and DFNA14, responsible for autosomal dominant, nonsyndromic hereditary hearing impairment. To identify a possible relationship between tlt in mice and DFNA6 and DFNA14 in humans, we have refined the mouse genetic map, assembled a BAC contig spanning the tlt locus, and developed a comprehensive comparative map between mouse and human. We have determined the position of tlt relative to 17 mouse chromosome 5 genes with orthologous loci in the human 4p16.3-p15 region. This analysis identified an inversion between the mouse and human genomes that places tlt and DFNA6/14 in close proximity.

This unit provides an introduction to the use of yeast artificial chromosome-bearing yeast clones (hereafter referred to as YAC clones) in genome analysis. It describes criteria for designing a polymerase chain reaction (PCR) assay to be used in screening a YAC core library and discusses the rationale for verification and characterization of YAC clones obtained from these core laboratories. Protocols for maintaining YAC clones, analyzing YAC insert structure, preparing YAC DNA, and subcloning YAC inserts into other vectors are presented elsewhere in this volume.

This unit provides a series of protocols describing the analysis and manipulation of an isolated YAC clone. The procedures are based upon the use of the YAC vector pYAC4. Once an isolated YAC clone has been obtained from a core laboratory, the clone can be analyzed as described herein. Methods for analysis involve growing and storing YAC-containing yeast strains and purifying YAC DNA in a form suitable for assessing the size of the artificial chromosome and for conventional Southern blotting. Preparation of yeast chromosomes in agarose plugs for subsequent analysis by pulsed-field gel electrophoresis is also described. Additional protocols are provided for recovering DNA fragments from the ends of a YAC genomic insert to be used as probes for detecting chimerism and for chromosome walking. Finally, preparation of high-molecular-weight YAC DNA is described and a general method for subcloning YAC inserts into cosmid or lambda vectors for higher-resolution analysis is provided.

The traditional approach to the study of biology employs small-scale experimentation that results in the description of a molecular sequence of known function or relevance. In the era of the genome the reverse is true, as large-scale cloning and gene sequencing come first, followed by the use of computational methods to systematically determine gene function and regulation. The overarching goal of this new approach is to translate the knowledge learned from a systematic, global analysis of genomic data into a complete understanding of biology. For investigators who study shock, the specific goal is to increase understanding of the adaptive response to injury at the level of the entire genome. This review describes our initial experience using DNA microarrays to profile stress-induced changes in gene expression. We conclude that efforts to apply genomics to the study of injury are best coordinated by multi-disciplinary groups, because of the extensive expertise required.

Plasmodium falciparum is a protozoan parasite responsible for the most severe forms of human malaria. All the clinical symptoms and pathological changes seen during human infection are caused by the asexual blood stages of Plasmodium. Within host red blood cells, the parasite undergoes enormous developmental changes during its maturation. In order to analyse the expression of genes during intraerythrocytic development, DNA microarrays were constructed and probed with stage-specific cDNA. Developmental upregulation of specific mRNAs was found to cluster into functional groups and revealed a co-ordinated programme of gene expression. Those involved in protein synthesis (ribosomal proteins, translation factors) peaked early in development, followed by those involved in metabolism, most dramatically glycolysis genes. Adhesion/invasion genes were turned on later in the maturation process. At the end of intraerythrocytic development (late schizogony), there was a general shut-off of gene expression, although a small set of genes, including a number of protein kinases, were turned on at this stage. Nearly all genes showed some regulation over the course of development. A handful of genes remained constant and should be useful for normalizing mRNA levels between stages. These data will facilitate functional analysis of the P. falciparum genome and will help to identify genes with a critical role in parasite progression and multiplication in the human host.

A yeast artificial chromosome sequence-tagged site-based (YAC/STS) physical map of 22.5 Mb of the Xq24-q26 cytogenetic band region of the human X chromosome has been assembled. DNA coverage includes 857 large-insert clones formatted with 405 STSs to provide ninefold depth of DNA. At five points, no bridging clones have been recovered from 20 X-chromosome equivalents of human DNA in YACs or bacterial clones, but the placement of 25 ("CA")n polymorphic markers permits the ordering of contigs by comparison with the genetic linkage map and radiation hybrid data. The map localizes the X3000 translocation breakpoint and six genes (ANT2, NDUFA1, LAMP2, OCRL, IGSF1, and HDGF) at better than 100-kb resolution. The relatively gene-poor nature of the region is consistent with relatively low uniform 34-42% GC content in STSs across nearly all of the region., (Copyright 1998 Academic Press.)

The 15Mb region between DXS997 and DXS8054 in Xp21.3-p11.3 has been mapped at seven-fold average coverage in yeast artificial chromosomes (YACs) and 100 kb inter-sequence tagged site (STS) distance. YACs from six different collections show self-consistent maps. The STSs include 18 (CA) repeat and one tetranucleotide repeat marker that detect polymorphism, as well as eight well-studied genes, a second site for MXS1 sequences, and three expressed sequence tags (ESTs). One of the ESTs maps to intron 7 of Duchenne muscular dystrophy, and seems to be a processed intronic sequence with a poly(A) tail.

As part of the Human Genome Project, the Washington University Genome Sequencing Center has commenced systematic sequencing of human chromsome 7. To organize and supply the effort, we have undertaken the construction of sequence-ready physical maps for defined chromosomal intervals. Map construction is a serial process composed of three main activities. First, candidate STS-positive large-insert PAC and BAC clones are identified. Next, these candidate clones are subjected to fingerprint analysis. Finally, the fingerprint data are used to assemble sequence-ready maps. The fingerprinting method we have devised is key to the success of the overall approach. We present here the details of the method and show that the fingerprints are of sufficient quality to permit the construction of megabase-size contigs in defined regions of the human genome. We anticipate that the high throughput and precision characteristic of our fingerprinting method will make it of general utility.

Patella fracture is a recognized complication of ACL reconstruction with an autogenous patella tendon graft. Typically, fracture occurs as a result of a fall. The incidence of fracture is approximately 0.5%. Accelerated rehabilitation protocols can place stress on the patella, especially in the initial stages of recovery. Therapists are reminded to observe constraints placed on patients by biological tissues, recovering neuromuscular status, and previous level of conditioning. Rehabilitation protocols should be revised according to these factors.

A description of dance injuries in a Broadway show using ballet technique is reported for the first time. Presentation of this material is used as a vehicle to discuss issues in dance epidemiology and etiology. As interest and research in dance medicine increases, standardization of reporting methods and definitions becomes critical in discussions of epidemiology and etiology. Borrowing from sports medicine classifications, which define sports injury as "time lost from play," we suggest dance injury be defined as "time lost from performing". The overall injury rate was 40.0%, which was low compared with those of classical ballet companies. The majority of injuries involved the foot and ankle, similar to previous reports of classical ballet companies. Reasons for the low injury rates and types of injuries are discussed. The information necessary to facilitate comparison of data with other studies is outlined. We hope this article will contribute to further discussion regarding adoption of universal language and details necessary for reporting injury. Additional areas of research are suggested.

A YAC/STS map of the X chromosome has reached an inter-STS resolution of 75 kb. The map density is sufficient to provide YACs or other large-insert clones that are cross-validated as sequencing substrates across the chromosome. Marker density also permits estimates of regional gene content and a detailed comparison of genetic and physical map distances. Five regions are detected with relatively high G + C, correlated with gene richness; and a 17-Mb region with very low recombination is revealed between the Xq13.3 [XIST] and Xq21.3 XY homology loci.

We screened two human yeast artificial chromosome (YAC) libraries by polymerase chain reaction (PCR) with oligonucleotides specific to the BCL1 major translocation breakpoint cluster region at 11q13. Five YACs were isolated. Two of them were chimeric. One of these and remaining three YACs were characterized by hybridization with various known 11q13 probes, Alu-PCR fingerprinting, in situ hybridization, and isolation of YAC ends. A map of this ca 700-kb YAC contig was obtained. This map was consistent with maps established from total human genomic DNA. Every YAC in this region was found unstable and gave rise to reproducibly deleted lineages. Analysis in detail of these deletions over many generations showed that more than a single sequence might be involved. The availability of cloned material will facilitate the search for the still elusive genetic elements responsible for amplifications, deletions and translocations observed at 11q13 in malignancies.

A map of the type-I interferon gene cluster located on the short arm of human chromosome 9 (9p) has been constructed using a contig of YAC clones. This map contains 26 interferon (IFN) genes and pseudogenes, and it accounts for all, except one, of the IFN sequences previously reported by other authors, plus a new IFNW pseudogene. The most distal gene on 9p is IFNB, and the most proximal one is IFNWP19. The direction of transcription for the 20 most distal IFN sequences is toward the telomere and for the 6 most proximal sequences, toward the centromere. Several regions of the cluster show evidence of ancestral duplication events. Some of these events may be explained by unequal crossing over between adjacent tandem genes. The location of several breakpoints within the cluster, from deletions associated with leukemias and gliomas, was also determined.

We have previously described a strategy for integrating selectable marker genes into yeast artificial chromosomes (YACs) to facilitate their transfer into embryonic stem (ES) cells. Here we apply this technology to create mice carrying the core region of the human immunoglobulin (Ig) kappa light chain locus. A YAC was isolated which contains a 300 kb insert spanning three V kappa segments, the J kappa cluster, the C kappa region and extending downstream of the Kde element. After modification of this YAC to integrate the selectable neo marker gene, the YAC was introduced into ES cells by protoplast fusion. Several ES cell clones were obtained which appeared to harbor one complete copy of the YAC while retaining little or no other yeast DNA. The ES cells were injected into blastocysts and the chimaeric mice were shown to rearrange the introduced human light chain genes with the resultant production of antibodies containing human kappa light chains in the serum.

Friedreich ataxia (FA) is a severe autosomal recessive neurodegenerative disease. The defective gene has been previously assigned to chromosome 9q13-q21 by demonstration of tight linkage to the two independent loci D9S15 and D9S5. Linkage data indicate that FRDA is at less than 1 cM from both markers. Previous physical mapping has shown that probes defining D9S15 (MCT112) and D9S5 (26P) are less than 260 kb apart and are surrounded by at least six CpG clusters within 450 kb, which might indicate the presence of "candidate" genes for FA. We isolated and characterized a 530 kb YAC (yeast artificial chromosome) contig that contains five of the CpG clusters. The YACs were used to search for new polymorphic markers needed to map FRDA precisely with respect to the cloned segment. In particular, we found a (CA)n microsatellite polymorphism, GS4, that detects 13 alleles with a PIC value of 0.83 and allows the definition of haplotypes extending over 310 kb when used in combination with polymorphic markers at D9S5 and D9S15.

The yeast artificial chromosome (YAC) system (Burke et al., 1987, Science 236: 806-812) allows the direct cloning of large regions of the genome. A YAC contig map of approximately 700 kb encompassing the region surrounding the type 1 neurofibromatosis (NF1) locus on 17q11.2 has been constructed. A single YAC containing the entire NF1 locus has been constructed by homologous recombination in yeast. In the process of contig construction a novel method of YAC end rescue has been developed by YAC circularization in yeast and plasmid rescue in bacteria. YACs containing homology to the NF1 region but mapping to another chromosome have also been discovered. Sequences of portions of the homologous locus indicate that this other locus is a nonprocessed pseudogene.

The genetic defects in Prader-Willi syndrome (PWS) and Angelman syndrome (AS) map to 15q11-13. Using microdissection, we have recently isolated several DNA probes for the critical region. Here we report that microclone MN7 detects multiple loci in 15q11-13 and 16p11.2. Eight yeast artificial chromosome (YAC) clones, two genomic phage clones, and two placenta cDNA clones were isolated to analyze these loci in detail. Two of the YAC clones map to 16p. Six YAC clones and two genomic phage clones contain a total of four or five different MN7 copies, which are spread over a large distance within 15q11-13. One cDNA clone is from chromosome 15 and one is from chromosome 16. The chromosome 15 cDNA detects transcripts of 14 and 8 kilobases in various human tissues. The presence of multiple copies of the MN7 gene family in proximal 15q may conceivably be related to the instability of this region and thus to the etiology of associated disorders.

The region surrounding the steroid sulfatase (STS) locus on Xp22.3 is of particular interest since it represents a deletion hot spot, shares homology with the proximal long arm of the Y chromosome (Yq11.2), and contains genes for several well-described X-linked disorders. Here we describe yeast artificial chromosomes (YACs) covering 450 kb around the STS gene. Eight YAC clones were isolated from a human YAC library. Their STS exon content was determined and the overlap of the clones characterized. Two of the YAC clones were found to contain the entire STS gene. The most proximal and the most distal ends of the YAC contig were cloned but neither of them crossed the breakpoints in any of the previously described patients with entire STS gene deletions. This is consistent with deletions larger than 500 kb in all these patients. One of the YAC clones was found to contain sequences from the STS pseudogene on Yq11.2. Two anonymous DNA sequences, GMGXY19 and GMGXY3, previously mapped in the vicinity of the STS locus, were found within the YAC contig and their assignment with respect to the STS locus was thus possible. This contig is useful for the overlap cloning of the Xp22.3 region and for reverse genetic strategies for the isolation of disease genes in the region. Furthermore, it may provide insight into the molecular mechanisms of deletion and translocation events on Xp22.3 and in the evolution of sex chromosomes.

To understand better the organization and linkage of the interleukin genes, IL4 and IL5, we prepared long-range restriction maps of five yeast artificial chromosomes (YACs) containing IL5. We determined that IL4 and IL5 are within 100-170 kb, and that the regions surrounding these genes contain several GC-rich areas. Fluorescence in situ chromosomal analysis demonstrated that three of the five YAC clones contain non-contiguous genomic sequences originating from multiple human chromosomes.

The recently developed technique for cloning genomic DNA fragments of several hundred kilobases or more into yeast artificial chromosomes (YACs) makes it possible to isolate gene families while preserving their structural integrity. We have analyzed five independent yeast clones identified by PCR screening using oligonucleotides derived from the adult human beta-globin gene. Analysis of the five clones containing YACs by conventional and pulsed-field gel electrophoresis revealed that all of the clones include a YAC with sequences from the adult beta-globin gene as expected. One of the clones contains multiple, unstable YACs. Two other clones carry single YACs in which there are at least two unrelated human genomic inserts. The remaining two clones contain single YACs, 150 and 220 kb in size, that contain the entire beta-globin gene family and flanking regions in a single, structurally intact genomic fragment. These should prove useful in future studies of the regulation of expression of genes in the beta-globin gene cluster.

The leukocyte-common antigen (CD45) is a transmembrane protein tyrosine phosphatase expressed uniquely by cells of hematopoietic origin. There are multiple isoforms of CD45 that are generated by the variable use of three exons (exons 4-6). The use of the variable exons results in changes near the amino-terminus of the mature glycoprotein. The gene is located on chromosome 1 for both human and mouse in a region that is homologous between these two species. This conserved linkage group contains a number of genes of immunological interest, such as the genes for complement regulatory proteins and the FCG2 receptor. Yeast artificial chromosomes provide a vector system in which large fragments of foreign DNA can be isolated and are suited to long-range physical mapping. To this end, three yeast artificial chromosomes containing the human CD45 gene have been isolated and characterized. They overlap to span 475 kb, establishing the largest physical map for DNA within the conserved linkage group. The CD45 gene is entirely encoded within one yeast artificial chromosome clone as determined by mapping with cDNA probes. A mouse B cell line transfected with this YAC clone expressed the low-molecular-weight isoform of the protein into the cell surface. The size of the human CD45 gene was determined to be approximately 120 +/- 10 kb.

A new method for screening of YAC libraries is described. Individual YACs were pooled into groups of 384 clones and prepared as samples suitable for pulsed-field gel electrophoresis. A five hit human YAC library (Brownstein et al., 1989) containing approximately 60,000 clones was condensed into 150 such pools and chromosomal DNAs in each sample were separated on three pulsed field gels containing 50 samples each. Southern blots prepared from these gels were hybridized with probes of interest to identify pools containing homologous YACs. Further purification was performed using standard colony hybridization procedures. Twenty-one probes used thus far have identified 47 positive pools and corresponding YACs have been purified from 28 of these. Some significant advantages of this method include avoidance of DNA sequence analysis and primer generation prior to YAC screening and the ability to handle the entire library on three filters. The screening approach described here permits rapid isolation of YACs corresponding to unsequenced loci and will accelerate establishment of YAC contigs for large chromosomal segments.

Wilms tumor is an embryonal kidney tumor involving complex pathology and genetics. The Wilms tumor locus on chromosome 11p13 is defined by the region of overlap of constitutional and tumor-associated deletions. Chromosome walking and yeast artificial chromosome (YAC) cloning were used to clone and map 850 kilobases of DNA. Nine CpG islands, constituting a "CpG island archipelago," were identified, including three islands that were not apparent by conventional pulsed-field mapping, and thus were at least partially methylated. Three distinct transcriptional units were found closely associated with a CpG island within the boundaries of a homozygous DNA deletion in a Wilms tumor.

alpha-Interferon (IFN-alpha) induced unique ultrastructural alterations in peripheral blood and splenic hairy cell leukemia (HCL) cells (14 of 20 cases) treated in vitro. To further investigate the effects of B-cell growth factor (BCGF) and IFN-alpha on target hairy cells (HCs), we utilized immunogold labeling in conjunction with scanning electron microscopy. This methodology, in contrast to other immunological methods, facilitated direct view of the expression, density, and rearrangement of selected antigens/receptors on individual cells before and after BCGF or IFN-alpha treatment. In addition to inducing proliferation of HCL cells, BCGF enhanced the expression of interleukin 2 receptors (CD25; T-activated cell antigen) with no change in the expression of class I and class II human leukocyte antigen. On the other hand, IFN-alpha did not exert a noticeable proliferative effect on HCL cells but rather inhibited the proliferation of BCGF-treated cells. In addition, IFN-alpha treatment revealed an enhanced expression of class I (4 of 9) and class II (12 of 15) human leukocyte antigen on target HCs. Two-day exposure of HCs to IFN-alpha resulted in enhanced expression of CD25 (11 of 14), whereas a decrease in CD25 expression was recorded in 4 of 5 cases treated with IFN-alpha for 3 days. Also, no significant change in the expression of two other HCL-related surface antigens, CD22 (S-HCL-1; Leu-14) and CD11c(S-HCL-3; Leu-M5), was recorded following up to 3 days of IFN-alpha or BCGF treatment. However, a 5-day exposure to IFN-alpha resulted in a significant decrease in expression of CD11c on treated HCs. Finally, the IFN-alpha-induced immunoultrastructural changes in target HCs were primarily encountered in cells from HCL cases classified as responders to in vivo IFN-alpha therapy. Our data add support to the concept that the effect of IFN-alpha in HCL is mediated by impairment of the response to B-cell growth factors and induction of further differentiation of the target cells.

Receptors for immunoglobulin G immune complexes (Fc gamma RII and Fc gamma RIII) are expressed on most hematopoietic cells and show much structural and functional diversity. In order to determine the genetic basis for this diversity, a family of genes encoding the human and mouse receptors was isolated and characterized. Humans have five distinct genes for low-affinity Fc gamma Rs, in contrast to two in the mouse. With the use of yeast artificial chromosomes, the genes encoding the human receptors were oriented and linked, which established the structure of this complex locus. Comparison of the human and mouse genes generated a model for the evolutionary amplification of this locus.

The nature of the interleukin 2 (IL-2) receptor on purified human B lymphocytes was examined. Both normal and malignant cells showed evidence of a 70-75,000 mol. wt (p75) IL-2 binding molecule as assessed by 125I-labeled IL-2 binding and receptor cross-linking. On normal, Tac-negative B lymphocytes the estimated number of p75 binding sites was 1100 per cell and the dissociation constant (Kd) was 1.7 nM. Consistent with this, cross-linking experiments demonstrated the presence of an IL-2 binding molecule of 70-75,000 mol. wt. Purified B cells from patients with hairy cell leukemia and chronic lymphocytic leukemia (CLL) also expressed the p75 IL-2 binding molecule. In the HCL samples, a small number of high-affinity IL-2 binding sites were detected (27-90) while the majority of binding sites (2100-10,800) were typical of low-affinity p55 Tac binding. IL-2 added to the purified normal and CLL B lymphocytes led to the induction of p55 Tac expression and the generation of high-affinity IL-2 receptors. This response to IL-2 was equivalent to the response observed when normal B lymphocytes were stimulated by Staphylococcus aureus Cowan I.

The mechanism of the antineoplastic effect of interferon (IFN) is not known and may result from direct effects on the neoplastic cells themselves, activation of intermediary effector cells, or a combination of these effects. The synthesis of specific proteins is induced in hairy cells when they are exposed to alpha-IFN in vitro. In particular, the called p80, is markedly induced. We investigated this effect in the hairy cells of seven patients in the leukemic phase of hairy cell leukemia who were being treated with subcutaneous (SC) IFN alpha 2b (r-Hu-IFN-alpha 2). Polyacrylamide gel electrophoresis (PAGE) was carried out on [35S]methionine-labeled whole cell lysates visualized by autoradiography and silver staining. Within 2 days of starting IFN therapy, induction of specific protein synthesis, including p80 was seen by [35S]methionine labeling in freshly isolated circulating hairy cells from 6 of 6 patients tested. Therefore, alpha-IFN has a direct biochemical effect on hairy cells in vivo that is similar to in vitro effects, at least with regard to p80 synthesis, although the kinetics of this effect may vary in the two situations.

A recently developed cloning system based on the propagation of large DNA molecules as linear, artificial chromosomes in the yeast Saccharomyces cerevisiae provides a potential method of cloning the entire human genome in segments of several hundred kilobase pairs. Most application of this system will require the ability to recover specific sequences from libraries of yeast artificial chromosome clones and to propagate these sequences in yeast without alterations. Two single-copy genes have now been cloned from a library of yeast artificial chromosome clones that was prepared from total human DNA. Multiple, independent isolates were obtained of the genes encoding factor IX and plasminogen activator inhibitor type 2. The clones, which ranged in size from 60 to 650 kilobases, were stable on prolonged propagation in yeast and appear to contain faithful replicas of human DNA.

The structure, synthesis, and post-transcriptional modifications of 23-S and 16-S ribosomal RNAs (rRNAs) have been studied in the facultatively parasitic bacterium, Bdellovibrio bacteriovorus. The mature 23-S and 16-S type of rRNAs in Bdellovibrio are larger than the analogous molecules in Escherichia coli by at least 1.0 - 10(5) and 0.5 - 10(5) daltons, respectively, and have a conformation different from E. coli rRNAs as judged by relative electrophoretic mobilities in polyacrylamide gels with and without denaturing conditions. Studies on the kinetics of synthesis and maturation of ribosomal RNA in Bdellovibrio show that precursor forms analogous to p23-S and p16-S in E. coli are synthesized. In addition, some earlier precursor rRNAs in Bdellovibrio are seen that appear analogous to the 25S and 17.5-S pre-rRNAs that have only been observed in the RNAase III deficient mutant of E. coli strain AB301-105 (Nikolaev, Birenbaum, M. and Schlessinger, D. (1975) Biocheim, Biophys. Acta 395, 478-489). These early precursor stages have not been observed in other procaryotic species, including E. coli that have normal levels of RNAase III. The results from the Bdellovibrio system provide that the 25-s and 17.5-S pre-rRNAs are normal stages of rRNA modification and are part of a multiple step maturation process, and therefore are not aberrations associated with the RNase III deficient mutation.

Despite the striking antiproliferative effect of alpha-interferon (alpha-IFN) in hairy cell leukemia, gamma-interferon (gamma-IFN) does not appear to have such an effect. We have previously demonstrated the induction of synthesis of specific proteins by alpha-IFN, both in vitro and in vivo. We have now shown that gamma-IFN induces synthesis of specific proteins, but the pattern differs from that seen after alpha-IFN exposure. The prominent 80,000-dalton protein induced by alpha-IFN was not induced by gamma-IFN, and the prominent 62,000-dalton protein induced by gamma-IFN was only rarely induced by alpha-IFN. Two other proteins were induced by both alpha-IFN and gamma-IFN. The other proteins induced by alpha-IFN were not induced by gamma-IFN. These differences may be related to the different biological response of hairy cells to the two types of IFN. We also showed for both alpha-IFN and gamma-IFN that some IFN-induced proteins are probably transported to the nucleus of the hairy cell, although the majority of proteins induced by both alpha-IFN and gamma-IFN were in the cytosol/membrane fraction of the cell. We have therefore demonstrated that gamma-IFN does have a biochemical effect on hairy cells in terms of induction of specific protein synthesis, leading to the inference that hairy cells must possess another receptor at least functionally analogous to the type II IFN receptors on fibroblasts, with which gamma-IFN interacts.

The striking clinical response of hairy cell leukemia to alpha-interferon led us to investigate the effects of interferon on hairy cells in vitro. We examined the nature of protein induction by interferon in the target hairy cells. To do this, we analyzed whole cell lysates of hairy cells from 11 patients by one-dimensional polyacrylamide gel electrophoresis. With this method, we showed the induction of 16 proteins, which ranged from Mr 140,000 to 12,000. Exposure to alpha-interferon caused very rapid induction of specific proteins in hairy cells, and induction continued for at least 9 days. Proteins were induced at extremely low interferon concentrations, and a dose-response effect was seen with increasing concentrations. A larger number of proteins was induced in hairy cells than in other lymphoid cells under the same conditions. Induction of most proteins was inhibited by actinomycin D, showing that new messenger RNA synthesis was required for their induction to occur. The number or pattern of induced proteins, or their prolonged induction, may be relevant to a change in the target hairy cells which is part of the process resulting in the antiproliferative effect of interferon in hairy cell leukemia.