Elevated metabolites of acetaminophen in cord blood of children with obesity.

BACKGROUND: High-throughput metabolomics has been used cross-sectionally to evaluate differential metabolic profiles associated with human obesity. OBJECTIVES: This study longitudinally assessed the cord blood metabolome to explore if metabolic signatures of obesity at age 3-5 are apparent at birth. METHODS: In a nested case-control design, metabolomics analysis was performed on umbilical cord blood of 25 children who developed obesity by age 3-5 years, compared with 25 sex-matched non-obese children enrolled as part of an ongoing birth cohort. Logistic regression models were used to identify significant metabolites, adjusting for maternal pre-pregnancy obesity. RESULTS: Children who had obesity by age 3-5 years had elevated levels of medium and long chain fatty acids including stearate, oleate and palmitate at birth. Children with obesity were also more likely to have elevated levels of acetaminophen metabolites at birth, specifically: 3-(N-acetyl-L-cystein-S-yl) acetaminophen, 2-hydroxyacetaminophen sulfate, 2-methoxyacetaminophen glucuronide and p-acetamidophenyl glucuronide. CONCLUSION: Although the observed increases in lipids are consistent with previous metabolomic studies of obesity, this study is the first to report associations between acetaminophen metabolites and obesity in children; however, we lack mechanistic insights for this link. Larger human studies with longer follow-up and laboratory-controlled animal experiments are needed to clarify associations.

Exploration of a new model of care in a psychiatry unit.

The model established at Orillia Soldiers Memorial Hospital involves family physicians as the most responsible physician. They act as "admission gatekeeper" for all unattached patients who are admitted to the psychiatry in-patient unit. A PubMed, EBSCO, OVID Medline, Embase, CINAHL, and Web of Science database review of the last 10 years (2006-2016) was undertaken. A satisfaction survey was undertaken. An intensive literature review found this model to be unique. The model has proved to be extremely efficient and cost-effective.

Flows through forest canopies in complex terrain.

Recent progress on boundary layer flow within and above tall forest canopies in complex terrain is reviewed from the perspective of developing methods to interpret carbon dioxide fluxes from tower measurements in real terrain. Two examples of complex terrain are considered in detail: a forest edge, which exemplifies nonuniform forests, and hilly terrain, which can lead to drainage currents at night. Dynamical arguments show that, when boundary layer winds approach a forest edge, the mean wind adjusts on a length scale of approximately 3L(c), where L(c) is the canopy drag length scale, which depends inversely on the leaf area density of the forest. Over a further distance that also scales on L(c), turbulence in the flow adjusts, and the mixing and transport in the canopy approaches the homogeneous limit. Even low hills change the neutral flow within and above the forest canopy substantially. When the canopy is tall, pressure gradients drive flow up both the upwind and downwind slopes of the hill, leading to an ejection of air out of the top of the canopy just downwind of the crest. This flow at the crest can then advect scalar out of the top of the forest, leading to large variations in the flux of scalar across the hill. At night, when the air near the ground cools and becomes stably stratified, turbulence within the canopy can collapse, even when the flow above the canopy remains turbulent. This leads to a decoupling of the air motions within the canopy from those above. The air above the canopy can then continue to pass up and over the hill, as it does in the neutral case, but at the same time, air within the canopy drains down the hill slopes as drainage currents. These analyses will help us understand when flux towers are reliably measuring the net ecosystem exchange and suggest ways of correcting the flux tower data in more complex situations.

Immunolocalization of ecto-nucleoside triphosphate diphosphohydrolase 3 in rat brain: implications for modulation of multiple homeostatic systems including feeding and sleep-wake behaviors.

Three anti-peptide antisera were raised against three distinct amino acid sequences of ecto-nucleoside triphosphate diphosphohydrolase 3 (NTPDase3), characterized by Western blot analyses, and used to determine the distribution of NTPDase3 protein in adult rat brain. The three antisera all yielded similar immunolocalization data, leading to increased reliability of the results obtained. Unlike NTPDase1 and NTPDase2, NTPDase3 immunoreactivity was detected exclusively in neurons. Immunoreactivity was localized primarily to axon-like structures with prominent staining of presynaptic elements. Specific perikaryal immunostaining was detected primarily in scattered neurons near the lateral hypothalamic area and the perifornical nucleus. High densities of immunoreactive axon-like fibers were present in midline regions of the forebrain and midbrain. Highly scattered NTPDase3 positive fibers were observed in the cerebral cortex, the hippocampal formation, and the basal ganglia. Moreover, very high densities of immunostained fibers were detected in the mediobasal hypothalamus, with the overall mesencephalic pattern of staining associated closely with hormone responsive nuclei. High densities of NTPDase3 positive terminals were also associated with noradrenergic neurons. However, co-immunolocalization studies revealed clearly that NTPDase3 immunoreactivity was not localized within the noradrenaline cells or terminals. In contrast, nearly all of the NTPDase3 immunopositive hypothalamic cells, and most fibers in the mid- and hindbrain, also expressed hypocretin-1/orexin-A. The overall pattern of expression and co-localization with hypocretin-1/orexin-A suggests that NTPDase3, by regulating the extracellular turnover of ATP, may modulate feeding, sleep-wake, and other behaviors through diverse homeostatic systems.

Sustainable development of urban transport systems and human exposure to air pollution.

DAPPLE (Dispersion of Air Pollution and Penetration into the Local Environment, http://www.dapple.org.uk) is a major research project that will provide the understanding necessary to assess the sustainability of urban road transport in terms of exposure to traffic-related air pollution as an alternative to current indicators based on emissions, roadside, or far-from-road air pollution levels. The methodology is described, which combines on-street and laboratory measurement with modelling of the movement of air, vehicles, and vehicle exhaust emissions. The relationship between this kind of assessment and more realistic indicators of sustainability is discussed. The value of large-scale interdisciplinary research in this area is thus demonstrated.

Introduction to the DAPPLE Air Pollution Project.

The Dispersion of Air Pollution and its Penetration into the Local Environment (DAPPLE) project brings together a multidisciplinary research group that is undertaking field measurements, wind tunnel modelling and computer simulations in order to provide better understanding of the physical processes affecting street and neighbourhood-scale flow of air, traffic and people, and their corresponding interactions with the dispersion of pollutants at street canyon intersections. The street canyon intersection is of interest as it provides the basic case study to demonstrate most of the factors that will apply in a wide range of urban situations. The aims of this paper are to introduce the background of the DAPPLE project, the study design and methodology for data collection, some preliminary results from the first field campaign in central London (28 April-24 May 2003) and the future for this work. Updated information and contact details are available on the web site at http://www.dapple.org.uk.

Time course and manner of Purkinje neuron death following a single ethanol exposure on postnatal day 4 in the developing rat.

The present study was designed to evaluate the time course and manner of Purkinje cell death following a single ethanol dose delivered intragastrically on postnatal day (PN) 4 to rat pups. Analysis included immunolabeling of Purkinje cells with antibody specific for calbindin D28k and counting of Purkinje cells in each lobule of a mid-vermal slice. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling analysis and immunodetection for cleaved (activated) caspase-3 enzyme was used to identify apoptosis, with calbindin D28k co-immunolabeling to identify apoptotic Purkinje cells. Finally, immunodetection for cytochrome c, again with co-labeling using calbindin D28k antibody, identified intracellular release of cytochrome c from the mitochondria into the cytoplasm of Purkinje cells. The data demonstrate that a single dose of ethanol results in a significant and extensive, lobular dependent loss of Purkinje cells within 24 h after administration. Extensive loss in the early developing lobules (I-III, VIII-X) and less to no loss in the later developing lobules (IV-VII) is consistent with prior literature reports on the ethanol-induced effects on Purkinje cells at this age. Clear and consistent evidence of apoptotic Purkinje cells was identified and the pattern was transient in nature. Finally, cytochrome c is released from the mitochondria of Purkinje cells in a time course consistent with the activation of the mitochondrial pathway of apoptosis. These data support the hypothesis that ethanol-induced loss of Purkinje cells involves apoptotic mechanisms. Furthermore, the initiation of apoptosis by ethanol is consistent with ethanol-induced interruptions of Purkinje cell neurotrophic support leading to activation of the mitochondrial pathway of apoptosis.

Estrogenic actions in the brain: estrogen, phytoestrogens, and rapid intracellular signaling mechanisms.

The endogenous gonadal steroid 17beta-estradiol (E2) plays an important role in the development, maturation, and function of a wide variety of reproductive and nonreproductive tissues, including those of the nervous system. The actions of E2 at target tissues can be divided into 1) long-term "genomic" actions that are mediated by intracellular estrogen receptor-induced changes in gene expression and 2) rapid actions that modulate a diverse array of intracellular signal transduction cascades. Environmental estrogens are compounds present in the environment that can mimic, and in some cases antagonize, the effects of endogenous estrogens. As a result of these actions, there is currently much interest within the scientific community regarding the relative benefits or threats associated with exposure to different environmental estrogens. Within the general public there is considerable acceptance of the benefits associated with increased use of "natural" estrogens as a component of a healthy diet and in postmenopausal women as an alternative to estrogen replacement therapies. First, this review will focus attention on the role of estrogens in the central nervous system by briefly discussing some of the known mechanisms through which estrogen's effects are mediated, focusing on rapid intracellular signaling mechanisms during neurodevelopment. Second, with the hope of bringing attention to an area of study that until recently has received little consideration, we will briefly discuss phytoestrogens and suggest that these compounds have the potential to influence rapid E2-induced mechanisms in the nervous system in ways that may result in modified brain functions.

Early postnatal ethanol exposure selectively decreases BDNF and truncated TrkB-T2 receptor mRNA expression in the rat cerebellum.

Binge-like ethanol exposure on postnatal day (PN) 4 induces a concentration dependent loss of Purkinje cells in the rat cerebellum. The mechanism of this ethanol-induced Purkinje cell vulnerability is not presently understood. Nevertheless, the specific timing of this vulnerability leads us to consider the neurotrophin system crucial to the regulation of neuronal development. Differentiation, maturation, and survival of Purkinje cells are shown to involve an intimate interaction between brain-derived nerve growth factor (BDNF) and neurotrophin-3 (NT3) acting primarily through their specific tyrosine-kinase (Trk) receptors. We believe that the specific ethanol vulnerability, and the timing of this vulnerability result from alterations in the BDNF-NT3 interplay. We hypothesize that disruption of TrkB and/or TrkC mediated neurotrophin communication is, in part, responsible for the ethanol-induced loss of Purkinje cells during development. The current study was undertaken to define the impact of ethanol exposure at the onset of ethanol vulnerability on the relative concentrations of mRNA encoding the neurotrophic factor receptors TrkB and TrkC. The reverse transcriptase (RT) polymerase chain reaction (PCR) amplification technique was used to identify the relative expression levels of mRNA specific to these receptors as well as the truncated TrkB receptor isoforms. We identify a specific decrease in overall TrkB receptor mRNA expression that is primarily a function of the TrkB-T2 receptor isoform. Concurrent decreases in mRNA specific to BDNF were also identified. No significant alterations to the expression of TrkC mRNA were found indicating that ethanol-exposure appears to act selectively on the BDNF communication system.

Simplified serum- and steroid-free culture conditions for high-throughput viability analysis of primary cultures of cerebellar granule neurons.

A serum- and steroid-free primary culture system was developed for the maintenance and automated analysis of cerebellar granule cell viability. Conventional poly-lysine coated 96-well tissue culture plates serve as a platform for growth, experimental manipulation and subsequent automated analysis of these primary cultured neurons. Cerebellar granule neurons were seeded at densities ranging from 2 x 10(4) to 1.25 x 10(6) cells/cm(2) and maintained in serum- and steroid-free culture conditions for 7 days. Viability was subsequently determined by the reduction of [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), and the degree of cell death occurring over that period was determined by the release of lactate dehydrogenase (LDH). At appropriate cell densities, the results of the MTS reduction and LDH release assays were directly proportional to the initial number of cerebellar granule cells plated. Those results indicate that an initial cell density of 0.5 - 1.0 x 10(5) cells per well (0.32 cm(2)) was appropriate for simultaneous analysis with the MTS reduction and LDH release assays. Both assays were then used to demonstrate the utility of this model system for analysis of tert-butyl-hydroperoxide and hydrogen peroxide induced oxidative stress. Additionally, the MTS reduction assay was used to demonstrate that the NMDA-receptor selective antagonist MK-801 was neuroprotective against glutamate-mediated excitotoxicity. This study defines a powerful and flexible primary culture system for cerebellar neurons that is useful for high-throughput analysis of factors that influence neuronal viability.

Identification of a developmental gradient of estrogen receptor expression and cellular localization in the developing and adult female rat primary somatosensory cortex.

Immunohistochemistry was used to investigate the spatiotemporal distribution of estrogen receptor alpha and beta (ER alpha, ER beta) in the posteromedial barrel subfield (PMBS) of the cerebral cortex in developing and adult female rats. Counting of immunopositive cells in predefined areas from each layer of the PMBS showed that at PN3, ER alpha immunoreactivity (IR) was present in every cell, whereas ER beta-IR was not detected. At PN6, about 59% of the cells were ER alpha immunopositive and low levels of ER beta-IR were observed in scattered cells. At PN18 the proportion of ER alpha-IR cells decreased to 49%; however, ER beta-IR became widespread and was detected in 39% of cells. By PN25 only faint ER alpha-IR was observed and in the adults ER alpha-IR was not detected. In contrast, at PN25 and in adults, ER beta-IR was detected in about half the cells of the PMBS. Regarding the cellular localization of ER-IR, at PN3 an outside-in gradient of cytoplasmic to nuclear localization of ER alpha-IR was observed. At PN18 and in adults ER beta-IR was preferentially localized to the nucleus of principal neurons, and to the cytoplasm of small, stellate-shaped interneurons. Together, these observations reveal a developmental transition of ER expression in the PMBS; ER alpha is expressed during early development, ER alpha and ER beta are co-expressed at later developmental times, and only ER beta is expressed in adults. These changes in ER expression and localization suggest that ER alpha and ER beta may play important, but different roles in the formation and function of the PMBS region of the primary somatosensory cortex.

Estrogen receptor beta immunoreactivity in differentiating cells of the developing rat cerebellum.

Estrogen receptors (ER) play a significant role in the development of some regions of the mammalian brain. Recently, ER-beta (ERbeta) mRNA and protein were shown to be expressed in the rat cerebellum. In the present study, the ontogeny of ERbeta protein expression was examined in the rat cerebellum during postnatal development. Western blot analysis indicated that a single ERbeta-like immunoreactive species of approximately 55 kDa was present in protein lysates prepared from the cerebella of female and male Sprague-Dawley rat pups. Immunocytochemical analysis of cerebellar sections from the midline vermis revealed that during development, the expression of ERbeta varied with age and cell-type, but not sex. In the developing cerebellum, highest levels of ERbeta-immunoreactivity (IR) were detected in neurons during neurite growth, and in some glia during migration. Throughout the first postnatal week, ERbeta-IR was localized to differentiating granule cells in the external germinal layer and to migrating glia. Differentiating granule cells expressed detectable levels of ERbeta throughout development. In Purkinje cells, ERbeta-IR was first detected on postnatal day 6 (P6), with peak intensities of immunostaining coinciding with the initiation of axonal and dendritic growth that occurs between P7 and P8. Expression of ERbeta-IR remained high during maturation of Purkinje cell dendrites, and then decreased to a lower level maintained in the adult. From the third postnatal week, ERbeta-IR was also detected in the later developing Golgi, stellate, and basket neurons. These results suggest that ERbeta may play a role in growth-related mechanisms during differentiation of cerebellar neurons and glia.

Regulated expression of estrogen receptor alpha and beta mRNA in granule cells during development of the rat cerebellum.

A semi-quantitative RT-PCR approach was used to characterize expression of the mRNA encoding estrogen receptors in developing cerebellar granule cells of the rat. Evidence is presented for expression of both ERalpha and ERbeta transcripts in granule cells throughout the first 15 postnatal days. While transcripts encoding both ERalpha and ERbeta were expressed in granule cells, the relative levels of expression varied significantly during the first two postnatal weeks of cerebellar development. The ERalpha mRNA was expressed at the lowest level on the first day following birth; whereas expression of ERbeta was highest on that day. On the fourth postnatal day the expression of ERalpha increased, while there was a significant decrease in ERbeta expression. Between postnatal day 4 and 15, the expression of the mRNA of each receptor varied in a similar fashion; expression decreased slightly between days 4 and 10 and then increased significantly on day 15. Alternative splicing of the ERbeta transcripts was also investigated and was likewise found to vary during granule cell development. Initially, the mRNA encoding the beta1 isoform was predominant, but by day 4, the beta2 isoform was the major isoform expressed. On postnatal days 7 and 10, there was not a significant difference between the level of beta1 and beta2 expressed. By day 15, beta1 was again the predominant ERbeta isoform accounting for nearly 90% of all ERbeta transcripts expressed.

Mutant alleles of the MRS2 gene of yeast nuclear DNA suppress mutations in the catalytic core of a mitochondrial group II intron.

Previous studies show that some yeast strains carrying point mutations of domain 5 that block splicing of a mitochondrial group II intron yield spontaneous revertants in which splicing is partially restored by dominant mutations of nuclear genes. Here we cloned and sequenced the suppressor allele of one such gene, and found it to be a missense mutation of the MRS2 gene (MRS2-L232F). The MRS2 gene was first implicated in group II intron splicing by the finding that overexpression of the wild-type gene weakly suppresses the splicing defect of a mutation of another intron. Tetrad analysis showed that independently isolated suppressors of two other domain 5 mutations are also allelles of the MRS2 gene and DNA sequencing identified a new missense mutation in each strain (MRS2-T230I and MRS2-L213M). All three suppressor mutations cause a temperature-sensitive respiration defect that is dominant negative in heterozygous diploids, but those strains splice the mutant intron at the elevated temperature. The three mutations are in a domain of the protein that is likely to be a helix-turn-helix region, so that effects of the mutations on protein-protein interactions may contribute to these phenotypes. These mutations suppress the splicing defect of many, but not all, of the available splicing defective mutations of aI5gamma, including mutations of several intron domains. Protein and RNA blot experiments show that the level of the protein encoded by the MRS2 gene, but not the mRNA, is elevated by these mutations. Interestingly, overexpression of the wild-type protein restores much lower levels of splicing than were obtained with similar elevated levels of the mutated Mrs2 proteins. The splicing phenotypes of these strains suggest a direct role for Mrs2 protein on group II intron splicing, but an indirect effect is not yet ruled out.

High-affinity kainate-type ion channels in rat cerebellar granule cells.

1. Patch-clamp recordings were made from rat cerebellar granule cells in primary culture. In cells pre-exposed to concanavalin A (ConA) to remove kainate receptor desensitization, concentration-response data for kainate showed two components. The EC50 value for the high-affinity component (4 microM) was consistent with activation of kainate-type channels. ConA enhanced the apparent potency of the kainate receptor ligand SYM 2081 by 100-fold. 2. In ConA-treated granule cells, currents evoked by 10 microM kainate were not significantly reduced by the AMPA receptor antagonist GYKI 53655, nor were these currents significantly reduced by the co-application of 100 microM AMPA. Currents activated by low concentrations of kainate in the presence of AMPA were completely inhibited by 10 microM La3+. 3. Single-cell reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicated that granule cells express both unedited (Q) and edited (R) versions of GluR5, with the majority of the GluR5 transcripts being unedited. In contrast, BluR6(R) was detected in seven cells and GluR6(Q) was detected in one granule cell. 4. Whole-cell current-voltage curves for kainate-type currents in granule cells were measured and the ratio of the slope conductances at +40 MV and -40 mV was used as an index of rectification. The mean +40 mV/-40 mV ratio determined from thirty-six granule cells was 1.3 +/- 0.1. Spectral density analysis of kainate-evoked whole-cell current noise gave values for the apparent single-channel conductance, gamma(noise), that were on average about 1 pS. 5. To compare further the properties of recombinant kainate channels with the native kainate-type channels in granule cells, we determined EC50 and gamma(noise) values for SYM 2081 in stable cell lines expressing either (GluR6(R) or GluR6(R) and KA2. Co-expression of KA2 with GluR6(R) shifts the EC50 and gamma(noise) values determined for SYM 2081 closer to the values typically found for native kainate-type channels in granule cells. 6. The results demonstrate that cerebellar granule cells in culture express functional kainate-type channels and that in most cells these channels show properties that are similar to those determined for heteromeric channels formed from GluR6(R) and KA2. However, the results also suggest that different granule cells express different repertoires of kainate-type channels with different, and perhaps variable, subunit composition.

Localization of the m2 muscarinic acetylcholine receptor protein and mRNA in cortical neurons of the normal and cholinergically deafferented rhesus monkey.

The m2 muscarinic acetylcholine receptor in the cerebral cortex has traditionally been thought of as an autoreceptor located on cholinergic fibers that originate from neurons in the nucleus basalis of Meynert. We now provide evidence for widespread localization of the m2 receptor in noncholinergic neurons and fibers of the cerebral cortex. The cellular and subcellular distribution of the m2 receptor protein and mRNA were examined in normal monkeys and in monkeys in which the cortical cholinergic afferents were selectively lesioned by injection of the specific immunotoxin, anti-p75NTR-saporin into the nucleus basalis. Both in normal and immunolesioned monkeys, the m2 mRNA and protein were localized in pyramidal and nonpyramidal neurons. In pyramidal neurons, membrane-associated receptor immunoreactivity was found exclusively in dendritic spines receiving asymmetric synapses, indicating that the m2 receptor may modulate excitatory neurotransmission at these sites. In nonpyramidal neurons, the m2 immunoreactivity was present along the cytoplasmic surface of membranes in cell bodies, dendrites and axons. Both in pyramidal and nonpyramidal neurons of normal and lesioned monkeys, the m2 receptor was located peri- and extra-synaptically, suggesting that it may be contacted by acetylcholine via volume transmission. The localization of the m2 receptor in cortical neurons and the sparing of m2 immunoreactivity in lesioned monkeys indicates that the m2 receptor is synthesized largely within the cortex and/or is localized to noncholinergic terminals of either intrinsic or extrinsic origin. These findings open the possibility that the loss of the m2 receptor in Alzheimer's disease may in part be due to degenerative changes in m2 positive neurons of the cortex rather than entirely due to the loss of autoreceptors.

Characterization of RNA editing of the glutamate-receptor subunits GluR5 and GluR6 in granule cells during cerebellar development.

The non-NMDA class of ionotropic glutamate receptors are subject to RNA editing resulting in single amino acid changes within individual subunits that make up these oligomeric receptors. These amino acid changes result in significant alterations of important channel properties. Both edited and unedited versions of the kainate-receptor subunits GluR5 and GluR6 are present in brain, but whether this reflects the expression of both versions in individual types of neurons or differences in editing between different cell types is unclear. To characterize editing in a single identified type of central neuron, we have determined the extent to which GluR5 and GluR6 mRNAs are edited in acutely isolated cerebellar granule cells. RT-PCR analysis revealed that editing at each site in GluR5 and GluR6 increased during early postnatal development. The Q/R site was predominantly unedited in GluR5, whereas GluR6 was mostly edited. The Q/R and Y/C sites of GluR6 were edited to similar extents, whereas a smaller percentage of transcripts were edited at the I/V site. The expression of two double-stranded RNA adenosine deaminases implicated in GluR editing (DRADA and RED1) increased in granule cells between postnatal days 1 and 15. Finally, cerebellar granule cells express a previously unreported variant of RED1 which appears to arise from developmentally regulated alternative splicing.

A new sodium channel alpha-subunit gene (Scn9a) from Schwann cells maps to the Scn1a, Scn2a, Scn3a cluster of mouse chromosome 2.

We have used a total of 27 AXB/BXA recombinant inbred mouse strains to determine the chromosomal location of a newly identified gene encoding an alpha-subunit isoform of the sodium channel from Schwann cells, Scn9a. Linkage analysis established that Scn9a mapped to the proximal segment of mouse chromosome 2. The segregation of restriction fragment length polymorphisms in 145 progeny from a Mus spretus x C57BL/6J backcross indicates that Scn9a is very tightly linked to Scn1a (gene encoding the type I sodium channel alpha-subunit of the brain) and forms part of a cluster of four Scna genes located on mouse chromosome 2.

Cloning of the cDNA encoding the sodium channel beta 1 subunit from rabbit.

Here, we report the nucleotide (nt) sequence of the cDNA encoding the sodium channel beta 1 subunit from rabbit (o beta 1). Cloning of the o beta 1 cDNA was accomplished by reverse transcription-polymerase chain reaction using rabbit brain RNA as a template for cDNA synthesis. The nt sequence of the o beta 1 cDNA predicts a 218-amino-acid polypeptide which is 96.3 and 97.3% identical to the beta 1 from human (h beta 1) and rat (r beta 1), respectively.