Real-time determination of enantiomeric and isomeric content using photoelectron elliptical dichroism

The fast and accurate analysis of chiral chemical mixtures is crucial for many applications but remains challenging. Here we use elliptically-polarized femtosecond laser pulses at high repetition rates to photoionize chiral molecules. The 3D photoelectron angular distribution produced provides molecular fingerprints, showing a strong forward-backward asymmetry which depends sensitively on the molecular structure and degree of ellipticity. Continuously scanning the laser ellipticity and analyzing the evolution of the rich, multi-dimensional molecular signatures allows us to observe real-time changes in the chemical and chiral content present with unprecedented speed and accuracy. We measure the enantiomeric excess of a compound with an accuracy of 0.4% in 10 min acquisition time, and follow the evolution of a mixture with an accuracy of 5% with a temporal resolution of 3 s. This method is even able to distinguish isomers, which cannot be easily distinguished by mass-spectrometry.

Angiotensin II receptor blocker pretreatment of rats undergoing sudden renal ablation

BACKGROUND

Subtotal nephrectomy (N) in rats results in progressive hypertension, proteinuria and renal lesions. Renin-angiotensin system blockade initiated at N prevents these changes; treatments failing to reduce hypertension and proteinuria do not.

METHODS

Ten Munich-Wistar rats underwent 1½ surgical N; eight littermates were pretreated with losartan (L) only for 6 weeks prior to 1½ N (N + L). Pretreated (n = 8; C + L) and untreated controls (C; n = 8) had sham operations.

RESULTS

Over 6 months, N and N + L rats developed ∼80% increase in glomerular filtration rate per nephron over C and C + L, P < 0.001). Hypertension (intra-arterial mean blood pressure 116 ± 6.8 mmHg in N rats versus 102 ± 3.2 in C, 104 ± 8.4 in C + L, and 104 ± 8.4 in N + L rats, P < 0.001 for all) and proteinuria (120 ± 20 mg/day in N versus 39 ± 10 in C, 34 ± 8 in C + L and 35 ± 8 in N + L, P < 0.001 for all) developed only in N. Focal segmental glomerulosclerosis (FSGS) (%) at 6 months was 20 ± 8 in N and 17.5 ± 8 in N + L (ns) and <1 in C and C + L (P < 0.001 versus N and N + L). Interstitial fractional volume (Vv), 4.0 ± 1.7% in C and 4.4 ± 1.6% in C + L (ns), was similarly increased to 7.5 ± 2.5% in N and 9.0 ± 3.9% in N+L (P < 0.04 versus C and C + L). Atrophic tubule Vv was increased by >300% in N and N + L over C and C + L (P < 0.02 for all). Glomerular volume doubled in N and N + L (P < 0.001). Podocyte foot process effacement was greater in N and NL than in C or C + L (P ≤ 0.02 for all). Thus, L given for 6 weeks prior to 1&frac12; N prevented hypertension and proteinuria over the subsequent 6 months without reducing glomerular hypertrophy, hyperfiltration or interstitial, tubular or FSGS lesions or foot process effacement.

CONCLUSIONS

These studies dissociated systemic hypertension and proteinuria from the renal lesions in this model. Durable effects of losartan on blood pressure and proteinuria likely represent epigenetic processes.

Altered interactions of tryptophan metabolites in first-episode neuroleptic-naive patients with schizophrenia

Schizophrenia is characterized by complex and dynamically interacting perturbations in multiple neurochemical systems. In the past, evidence for these alterations has been collected piecemeal, limiting our understanding of the interactions among relevant biological systems. Earlier, both hyper- and hyposerotonemia were variously associated with the longitudinal course of schizophrenia, suggesting a disturbance in the central serotonin (5-hydroxytryptamine (5-HT)) function. Using a targeted electrochemistry-based metabolomics platform, we compared metabolic signatures consisting of 13 plasma tryptophan (Trp) metabolites simultaneously between first-episode neuroleptic-naive patients with schizophrenia (FENNS, n=25) and healthy controls (HC, n=30). We also compared these metabolites between FENNS at baseline (BL) and 4 weeks (4w) after antipsychotic treatment. N-acetylserotonin was increased in FENNS-BL compared with HC (P=0.0077, which remained nearly significant after Bonferroni correction). N-acetylserotonin/Trp and melatonin (Mel)/serotonin ratios were higher, and Mel/N-acetylserotonin ratio was lower in FENNS-BL (all P-values<0.0029), but not after treatment, compared with HC volunteers. All three groups had highly significant correlations between Trp and its metabolites, Mel, kynurenine, 3-hydroxykynurenine and tryptamine. However, in the HC, but in neither of the FENNS groups, serotonin was highly correlated with Trp, Mel, kynurenine or tryptamine, and 5-hydroxyindoleacetic acid (5HIAA) was highly correlated with Trp, Mel, kynurenine or 3-hydroxykynurenine. A significant difference between HC and FENNS-BL was further shown only for the Trp-5HIAA correlation. Thus, some metabolite interactions within the Trp pathway seem to be altered in the FENNS-BL patients. Conversion of serotonin to N-acetylserotonin by serotonin N-acetyltransferase may be upregulated in FENNS patients, possibly related to the observed alteration in Trp-5HIAA correlation. Considering N-acetylserotonin as a potent antioxidant, such increases in N-acetylserotonin might be a compensatory response to increased oxidative stress, implicated in the pathogenesis of schizophrenia.

Efficacy and Safety of N-3 Phosphatidylserine in Children with Attention Deficit and Hyperactivity Disorder (ADHD)

Attention-deficit/hyperactivity disorder (ADHD) encompasses a broad constellation of behavioral and learning problems. These patients are also characterized by low blood long-chain polyunsaturated fatty acid concentrations; however their supplementation effect on ADHD symptoms is not clear. It was recently (1) shown in children with inattention that consumption of n-3 phosphatidylserine (PS) for 3-mo favorably affected their visual sustained attention performance. We aimed to evaluate in children with ADHD the effect of n-3 PS on ADHD symptoms and wellbeing.

Methods:

In this 15-week, randomized, double-blind, placebo-controlled, parallel study the impact and tolerability of 150 mg b.i.d. n-3 PS were investigated in 200 children (6-13-y) with ADHD. Efficacy was assessed by teachers’ Conners Rating Scale (CRS) and strength and difficulties questionnaires (SDQ) - school version and clinicians who filled Clinical Global Impression of Improvement. Additional measures included parental rating of behavior (CRS and SDQ - home version) and wellbeing (Child Health questionnaire - Parental Form 50), and continuous performance test (Test of Variables of Attention). Safety evaluation included adverse event reports, vital signs, and parents’ Barkley’ side effects rating scale.

Results:

The interim results of the first group of children that were randomly assigned in a 2:1 ratio to n-3 PS or placebo will be presented.

Conclusions:

n-3 PS impact on ADHD symptoms at school and home as evaluated by teachers, clinicians, and parents will be discussed.

Acknowledgement:

This work was sponsored by Enzymotec LTD.

Angiotensin II receptor blockade blocker pre-treatment largely prevents injury from gradual renal ablation in rats

INTRODUCTION

Reduction in renal mass in rats results in progressive proteinuria, hypertension, focal-segmental glomerulosclerosis (FSG), atrophy of tubules (AT), and interstitial expansion. We reported that slow reduction of renal tissue in rats (slow ablation) ending in the removal of 1.5 kidneys is associated, over the next six months, with higher albumin excretion rates (AER) and accelerated development of FSG lesions compared to sudden equivalent renal mass reduction. It was hypothesised that slow reduction of nephron numbers allows for a process of conditioning of residual nephrons that increases their susceptibility to subsequent injury.

METHODS

To test this idea we treated Münich-Wistar rats with the angiotensin receptor blocker (ARB) losartan for six weeks during the gradual staged surgical removal of 1.5 kidneys, and compared them to sham operated controls, and parallel groups untreated by losartan.

RESULTS

Despite discontinuation of losartan over the subsequent six months, ARB pre-treatment completely prevented proteinuria and hypertension in these slow renal ablation rats. ARB pre-treatment also largely prevented the subsequent development of FSG, AT, and interstitial expansion in these animals. Both losartan-treated and untreated renal ablation groups had glomerular enlargement and compensatory hyperfiltration and this was uninfluenced by losartan.

CONCLUSION

Temporary ARB administration during gradual renal mass reduction resulted in long-term prevention of hypertension and albuminuria and greatly reduced FSG and tubular and interstitial lesions. We hypothesise that the preconditioning of residual nephrons in the gradual ablation model which facilitates their subsequent injury, is blunted by renin-angiotensin system blockade.

Comparison of methods for counting cells in the mouse glomerulus

BACKGROUND

Researchers have long been interested in counting the number of cells within the glomerulus. Investigators using different techniques have yielded conflicting results. The most direct method is to count the cells in serial sections from the entire glomerulus. This Exhaustive Count method is not usually practical. The disector/fractionator method counts the number of cells in a fraction of sections. The total is estimated from the product of the cell count and the reciprocal of the fraction. The Weibel-Gomez method determines the density of cells per glomerulus, then multiplies this density by glomerular volume to obtain cell number. In this study, we compared the disector/fractionator and Weibel-Gomez methods to identify a practical alternative for the time-consuming Exhaustive Count method.

METHODS

Glomeruli from a normal mouse kidney were completely sectioned and images obtained. Appropriate images were used to count glomerular cell number using each method.

RESULTS

The Exhaustive Count method yielded 213 +/- 22 (mean +/- SD) cells/glomerulus vs. the disector/fractionator average of 211 +/- 29 cells/glomerulus (p = 0.82). The Weibel-Gomez method average of 235 +/- 26 cells/glomerulus was statistically different from the Exhaustive Count method (p = 0.003).

CONCLUSION

The Weibel-Gomez produced a 10% overestimation, whereas the disector/fractionator method was unbiased and thus a good substitute for the Exhaustive Count method.

Enalapril accelerates remodeling of the renal interstitium after release of unilateral ureteral obstruction in rats

Complete ureteral obstruction in rats rapidly leads to renal interstitial expansion and fibrosis and this process is ameliorated by concomitant angiotensin converting enzyme inhibition (ACEI). However, models of intervention initiated after unilateral ureteral obstruction (UUO) release may be more analogous to human obstructive renal disease where treatment could more reasonably follow the discovery of obstructive uropathy as compared to models where treatment is initiated at the time of experimentally induced obstruction. We studied interstitial changes in rats before and after release of UUO and examined the effect of ACEI with 200mg/L of enalapril (E) in the drinking water on these changes. Rats were sacrificed after 10 (n=10) and 20 (n=10) days (D) of UUO or 10D after release of 10D of UUO (n=18). Eleven rats received E for 10D after UUO release. Cortical interstitial volume fraction [Vv(I/C)] measured by point counting was increased at 10D (0.32 +/- 0.05) and 20D (0.41 +/- 0.05) of UUO compared to contralateral and sham-operated kidneys (both 0.05 +/- 0.01, ANOVA, p <0.001). Vv(I/C) 10D after release from 10D of UUO (0.26 +/- 0.04) was lower than that of 10D of UUO (p<0.05) and much lower than those with 20D of UUO (p<0.001). However, rats treated with E from the time of UUO release had lower Vv(I/C) (0.21 +/- 0.07) than UUO released E untreated rats (p<0.05). Release of UUO initiates regression of interstitial expansion in rats. ACEI with enalapril significantly accelerates reversal of interstitial expansion after UUO release. This could have important implications for treatment of obstructive nephropathy in humans.

Synthesis of alpha-fluorocarboxylates from the corresponding acids using acetyl hypofluorite

alpha-Fluorocarboxylic esters and acids were synthesized in good yields. The corresponding esters and acids were converted to their ketene acetals, and these enol derivatives reacted with AcOF made directly from fluorine. This route circumvents the problems associated with nucleophilic fluorinations such as various eliminations and rearrangements. alpha- and beta-branched carboxylic acid derivatives that cannot be directly fluorinated gave by this electrophilic fluorination the corresponding alpha-fluoro derivatives in good yield. Both the fluorination reaction and the preparation of AcOF are fast and suitable for [18]F incorporation into acids and esters needed for working with PET. alpha-Fluoroibuprofen (20) and methyl 2-fluoro-3,3,3-triphenylpropionate (32) are two examples of this general reaction.

The AZFc region of the Y chromosome features massive palindromes and uniform recurrent deletions in infertile men

Deletions of the AZFc (azoospermia factor c) region of the Y chromosome are the most common known cause of spermatogenic failure. We determined the complete nucleotide sequence of AZFc by identifying and distinguishing between near-identical amplicons (massive repeat units) using an iterative mapping-sequencing process. A complex of three palindromes, the largest spanning 3 Mb with 99.97% identity between its arms, encompasses the AZFc region. The palindromes are constructed from six distinct families of amplicons, with unit lengths of 115-678 kb, and may have resulted from tandem duplication and inversion during primate evolution. The palindromic complex contains 11 families of transcription units, all expressed in testis. Deletions of AZFc that cause infertility are remarkably uniform, spanning a 3.5-Mb segment and bounded by 229-kb direct repeats that probably served as substrates for homologous recombination.

A physical map of the human Y chromosome

The non-recombining region of the human Y chromosome (NRY), which comprises 95% of the chromosome, does not undergo sexual recombination and is present only in males. An understanding of its biological functions has begun to emerge from DNA studies of individuals with partial Y chromosomes, coupled with molecular characterization of genes implicated in gonadal sex reversal, Turner syndrome, graft rejection and spermatogenic failure. But mapping strategies applied successfully elsewhere in the genome have faltered in the NRY, where there is no meiotic recombination map and intrachromosomal repetitive sequences are abundant. Here we report a high-resolution physical map of the euchromatic, centromeric and heterochromatic regions of the NRY and its construction by unusual methods, including genomic clone subtraction and dissection of sequence family variants. Of the map's 758 DNA markers, 136 have multiple locations in the NRY, reflecting its unusually repetitive sequence composition. The markers anchor 1,038 bacterial artificial chromosome clones, 199 of which form a tiling path for sequencing.

BrF3, an underutilized reagent in organic chemistry: a novel C-C-N to C-N-C rearrangement

Little is known about bromine trifluoride in organic chemistry. Under the right conditions, it can be a useful tool and generate a new and unprecedented chemistry. Thus, when reacted with oxime methyl ethers of alpha-ketoesters, BrF3 was able to convert the oxime group into a CF2 group and through a new type of rearrangement cause a shift of the carboxylate group to the nitrogen atom. The novel structure of the alpha,alpha-difluorocarbamate was also proven by 15N NMR as demonstrated for compounds 3, 8, 9, 12, 15, and 18. Another novel "double rearrangement" was observed during the formation of 19. Dynamic 19F NMR experiments indicate a high nitrogen inversion-rotation (NIR) barrier for these novel carbamates of about 12.5 kcal/mol.

A simple procedure for the analysis of single nucleotide polymorphisms facilitates map-based cloning in Arabidopsis

We developed a modified allele-specific PCR procedure for assaying single nucleotide polymorphisms (SNPs) and used the procedure (called SNAP for single-nucleotide amplified polymorphisms) to generate 62 Arabidopsis mapping markers. SNAP primers contain a single base pair mismatch within three nucleotides from the 3' end of one allele (the specific allele) and in addition have a 3' mismatch with the nonspecific allele. A computer program called SNAPER was used to facilitate the design of primers that generate at least a 1,000-fold difference in the quantity of the amplification products from the specific and nonspecific SNP alleles. Because SNAP markers can be readily assayed by electrophoresis on standard agarose gels and because a public database of over 25,000 SNPs is available between the Arabidopsis Columbia and Landsberg erecta ecotypes, the SNAP method greatly facilitates the map-based cloning of Arabidopsis genes defined by a mutant phenotype.

Deletion of azoospermia factor a (AZFa) region of human Y chromosome caused by recombination between HERV15 proviruses

Deletion of any of three regions of the human Y chromosome results in spermatogenic failure and infertility. We previously sequenced one of these regions, azoospermia factor a (AZFa) and found that it spanned approximately 800 kb. By sequence-tagged site (STS) content mapping, we roughly defined deletion breakpoints in two unrelated, azoospermic men with AZFa deletions. The positions of proximal and distal breakpoints were similar in the two men. Hypothesizing that the deletions might have been generated by homologous recombination, we searched electronically for DNA sequence similarities between the proximal and distal breakpoint regions. These comparisons revealed the most striking sequence similarities anywhere along or near the AZFa region. In the proximal breakpoint region, we identified a 10 kb provirus of the recently defined HERV15 class of endogenous retroviruses. In the distal breakpoint region, we found a second HERV15 provirus, 94% identical in DNA sequence to the first and in the same orientation. (A partial LINE insertion in this distal provirus proved to be the basis of the previously described DYS11/p12f polymorphism.) The AZFa deletions in the two men differed slightly, but all breakpoints fell within the HERV15 proviruses. Indeed, sequencing of deletion junctions from the two men revealed that homologous recombination had occurred within large domains of absolute sequence identity between the proximal and distal proviruses. When combined with published STS mapping data for other AZFa-deleted men, our findings suggest that recombination between these two HERV15 proviruses could account for most AZFa deletions.

At Last, 1,10-Phenanthroline-N,N'-dioxide, A New Type of Helicene, has been Synthesized using HOF small middle dotCH(3)CN

For more than 50 years the synthesis of 1,10-phenanthroline-N,N'-dioxide (2) has been sought. The reason for the failure of all the earlier attempts is that the limited space in the bay area of the starting material 1,10-phenanthroline (1) cannot accommodate two oxygen atoms. The oxidation has now been achieved with the oxygen-transfer agent HOF small middle dotCH(3)CN, and X-ray studies have revealed that the product is not planar but is a new type of helicene-in this way the "space problem" for the two oxygen atoms has been solved.

New techniques for DNA sequence classification

DNA sequence classification is the activity of determining whether or not an unlabeled sequence S belongs to an existing class C. This paper proposes two new techniques for DNA sequence classification. The first technique works by comparing the unlabeled sequence S with a group of active motifs discovered from the elements of C and by distinction with elements outside of C. The second technique generates and matches gapped fingerprints of S with elements of C. Experimental results obtained by running these algorithms on long and well conserved Alu sequences demonstrate the good performance of the presented methods compared with FASTA. When applied to less conserved and relatively short functional sites such as splice-junctions, a variation of the second technique combining fingerprinting with consensus sequence analysis gives better results than the current classifiers employing text compression and machine learning algorithms.

A high-density integrated genetic linkage and radiation hybrid map of the laboratory rat

The laboratory rat (Rattus norvegicus) is a key animal model for biomedical research. However, the genetic infrastructure required for connecting phenotype and genotype in the rat is currently incomplete. Here, we report the construction and integration of two genomic maps: a dense genetic linkage map of the rat and the first radiation hybrid (RH) map of the rat. The genetic map was constructed in two F2 intercrosses (SHRSP x BN and FHH x ACI), containing a total of 4736 simple sequence length polymorphism (SSLP) markers. Allele sizes for 4328 of the genetic markers were characterized in 48 of the most commonly used inbred strains. The RH map is a lod >/= 3 framework map, including 983 SSLPs, thereby allowing integration with markers on various genetic maps and with markers mapped on the RH panel. Together, the maps provide an integrated reference to >3000 genes and ESTs and >8500 genetic markers (5211 of our SSLPs and >3500 SSLPs developed by other groups). [Bihoreau et al. (1997); James and Tanigami, RHdb (http:www.ebi.ac.uk/RHdb/index.html); Wilder (http://www.nih.gov/niams/scientific/ratgbase); Serikawa et al. (1992); RATMAP server (http://ratmap.gen.gu.se)] RH maps (v. 2.0) have been posted on our web sites at http://goliath.ifrc.mcw.edu/LGR/index.html or http://curatools.curagen.com/ratmap. Both web sites provide an RH mapping server where investigators can localize their own RH vectors relative to this map. The raw data have been deposited in the RHdb database. Taken together, these maps provide the basic tools for rat genomics. The RH map provides the means to rapidly localize genetic markers, genes, and ESTs within the rat genome. These maps provide the basic tools for rat genomics. They will facilitate studies of multifactorial disease and functional genomics, allow construction of physical maps, and provide a scaffold for both directed and large-scale sequencing efforts and comparative genomics in this important experimental organism.

The LabFlow system for workflow management in large scale biology research laboratories

LabFlow is a workflow management system designed for large scale biology research laboratories. It provides a workflow model in which objects flow from task to task under programmatic control. The model supports parallelism, meaning that an object can flow down several paths simultaneously, and sub-workflows which can be invoked subroutine-style from a task. The system allocates tasks to Unix processes to achieve requisite levels of multiprocessing. The system uses the LabBase data management system to store workflow-state and laboratory results. LabFlow provides a Per15 object-oriented framework for defining workflows, and an engine for executing these. The software is freely available.

A physical map of 30,000 human genes

A map of 30,181 human gene-based markers was assembled and integrated with the current genetic map by radiation hybrid mapping. The new gene map contains nearly twice as many genes as the previous release, includes most genes that encode proteins of known function, and is twofold to threefold more accurate than the previous version. A redesigned, more informative and functional World Wide Web site (www.ncbi.nlm.nih.gov/genemap) provides the mapping information and associated data and annotations. This resource constitutes an important infrastructure and tool for the study of complex genetic traits, the positional cloning of disease genes, the cross-referencing of mammalian genomes, and validated human transcribed sequences for large-scale studies of gene expression.

The LabBase system for data management in large scale biology research laboratories

MOTIVATION

The development of laboratory information management systems (LIMSs) for large scale biology research projects can be a challenging problem. Many such projects generate complex datasets via complex procedures that undergo continuous refinement. A key software challenge is to simplify the database-development task so that databases can be built and modified quickly enough to keep pace with changing project-requirements.

RESULTS

LabBase extends the facilities offered by relational database systems to simplify the task of creating databases for large scale biology research projects. LabBase provides a structural object data model, similar to ACEDB, and adds to this the concepts of Materials, Steps, and States: Materials are objects representing the identifiable things that participate in a laboratory protocol; Steps are objects reporting the results of a laboratory or analytical procedure; and States are objects denoting places in a laboratory protocol. The system provides a data definition language for succinctly defining laboratory databases, and operations for conveniently storing and retrieving data in such databases. The system also provides support for workflow management. LabBase is implemented in Perl5 and provides a natural interface for laboratory application programs written in Perl.

AVAILABILITY

The software is freely available. Contact the authors.

CONTACT

nat@jax.org

Large-scale identification, mapping, and genotyping of single-nucleotide polymorphisms in the human genome

Single-nucleotide polymorphisms (SNPs) are the most frequent type of variation in the human genome, and they provide powerful tools for a variety of medical genetic studies. In a large-scale survey for SNPs, 2.3 megabases of human genomic DNA was examined by a combination of gel-based sequencing and high-density variation-detection DNA chips. A total of 3241 candidate SNPs were identified. A genetic map was constructed showing the location of 2227 of these SNPs. Prototype genotyping chips were developed that allow simultaneous genotyping of 500 SNPs. The results provide a characterization of human diversity at the nucleotide level and demonstrate the feasibility of large-scale identification of human SNPs.

A map of 75 human ribosomal protein genes

We mapped 75 genes that collectively encode >90% of the proteins found in human ribosomes. Because localization of ribosomal protein genes (rp genes) is complicated by the existence of processed pseudogenes, multiple strategies were devised to identify PCR-detectable sequence-tagged sites (STSs) at introns. In some cases we exploited specific, pre-existing information about the intron/exon structure of a given human rp gene or its homolog in another vertebrate. When such information was unavailable, selection of PCR primer pairs was guided by general insights gleaned from analysis of all mammalian rp genes whose intron/exon structures have been published. For many genes, PCR amplification of introns was facilitated by use of YAC pool DNAs rather than total human genomic DNA as templates. We then assigned the rp gene STSs to individual human chromosomes by typing human-rodent hybrid cell lines. The genes were placed more precisely on the physical map of the human genome by typing of radiation hybrids or screening YAC libraries. Fifty-one previously unmapped rp genes were localized, and 24 previously reported rp gene localizations were confirmed, refined, or corrected. Though functionally related and coordinately expressed, the 75 mapped genes are widely dispersed: Both sex chromosomes and at least 20 of the 22 autosomes carry one or more rp genes. Chromosome 19, known to have a high gene density, contains an unusually large number of rp genes (12). This map provides a foundation for the study of the possible roles of ribosomal protein deficiencies in chromosomal and Mendelian disorders.

The DAZ gene cluster on the human Y chromosome arose from an autosomal gene that was transposed, repeatedly amplified and pruned

It is widely believed that most or all Y-chromosomal genes were once shared with the X chromosome. The DAZ gene is a candidate for the human Y-chromosomal Azoospermia Factor (AZF). We report multiple copies of DAZ (> 99% identical in DNA sequence) clustered in the AZF region and a functional DAZ homologue (DAZH) on human chromosome 3. The entire gene family appears to be expressed in germ cells. Sequence analysis indicates that the Y-chromosomal DAZ cluster arose during primate evolution by (i) transposing the autosomal gene to the Y, (ii) amplifying and pruning exons within the transposed gene and (iii) amplifying the modified gene. These results challenge prevailing views of sex chromosome evolution, suggesting that acquisition of autosomal fertility genes is an important process in Y chromosome evolution.

A gene map of the human genome

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

An STS-based map of the human genome

A physical map has been constructed of the human genome containing 15,086 sequence-tagged sites (STSs), with an average spacing of 199 kilobases. The project involved assembly of a radiation hybrid map of the human genome containing 6193 loci and incorporated a genetic linkage map of the human genome containing 5264 loci. This information was combined with the results of STS-content screening of 10,850 loci against a yeast artificial chromosome library to produce an integrated map, anchored by the radiation hybrid and genetic maps. The map provides radiation hybrid coverage of 99 percent and physical coverage of 94 percent of the human genome. The map also represents an early step in an international project to generate a transcript map of the human genome, with more than 3235 expressed sequences localized. The STSs in the map provide a scaffold for initiating large-scale sequencing of the human genome.

Diverse spermatogenic defects in humans caused by Y chromosome deletions encompassing a novel RNA-binding protein gene

We have detected deletions of portions of the Y chromosome long arm in 12 of 89 men with azoospermia (no sperm in semen). No Y deletions were detected in their male relatives or in 90 other fertile males. The 12 deletions overlap, defining a region likely to contain one or more genes required for spermatogenesis (the Azoospermia Factor, AZF). Deletion of the AZF region is associated with highly variable testicular defects, ranging from complete absence of germ cells to spermatogenic arrest with occasional production of condensed spermatids. We find no evidence of YRRM genes, recently proposed as AZF candidates, in the AZF region. The region contains a single-copy gene, DAZ (Deleted in AZoospermia), which is transcribed in the adult testis and appears to encode an RNA binding protein. The possibility that DAZ is AZF should now be explored.

Eosinophilic pleural effusion in cutaneous myiasis

We have reported the case of a 54-year-old man with recurrent painful migratory subcutaneous nodules associated with marked blood eosinophilia and an eosinophilic pleural effusion. The entire syndrome was subsequently determined to be due to cutaneous myiasis caused by the larvae of Hypoderma lineatum, the cattle botfly. Infestation by this or other dipterous fly larvae should be among the parasitic diseases considered in the differential diagnosis of any patient with similar symptoms.

Familial colon cancer in the Tel-Aviv area and the influence of ethnic origin

The family history of colon cancer was investigated in 38,823 individuals (2,129 families) who comprised a control and an oncology patient series from Tel-Aviv and nearby areas. A significant increased risk for colon cancer was observed among first-degree relatives of colon cancer patients when compared to controls. When the patient sample was divided into two groups based on country and continent of birth--European (Ashkenazim) and other (nonAshkenazim)--the relatives of the nonAshkenazi subjects showed a greater relative risk for colon cancer (P less than 0.05). Colon cancer was found to be less frequent in nonAshkenazim than in Ashkenazim controls. These findings suggest that although the colon cancer frequency in the nonAshkenazi group is lower, the genetic component may be more important than for the Ashkenazi sample. The nonAshkenazi Jews may represent distinct subgroups that differ with respect to either primary genetic susceptibility to colorectal cancer and/or they may have been subjected to peculiar, environmental carcinogenic exposures when compared to their Ashkenazim brethren.

Familial colon cancer in the Tel-Aviv area and the influence of ethnic origin

The family history of colon cancer was investigated in 38,823 individuals (2,129 families) who comprised a control and an oncology patient series from Tel-Aviv and nearby areas. A significant increased risk for colon cancer was observed among first-degree relatives of colon cancer patients when compared to controls. When the patient sample was divided into two groups based on country and continent of birth--European (Ashkenazim) and other (nonAshkenazim)--the relatives of the nonAshkenazi subjects showed a greater relative risk for colon cancer (P less than 0.05). Colon cancer was found to be less frequent in nonAshkenazim than in Ashkenazim controls. These findings suggest that although the colon cancer frequency in the nonAshkenazi group is lower, the genetic component may be more important than for the Ashkenazi sample. The nonAshkenazi Jews may represent distinct subgroups that differ with respect to either primary genetic susceptibility to colorectal cancer and/or they may have been subjected to peculiar, environmental carcinogenic exposures when compared to their Ashkenazim brethren.

Marfanoid hypermobility syndrome associated with Duane's retraction syndrome

Marfanoid hypermobility syndrome together with Duane's retraction syndrome in two sisters is presented. To our knowledge, this is the first report of such a combination. A possible mode of inheritance is suggested.