Identification of polypeptides encoded in open reading frame 1b of the putative polymerase gene of the murine coronavirus mouse hepatitis virus A59.

The polypeptides encoded in open reading frame (ORF) 1b of the mouse hepatitis virus A59 putative polymerase gene of RNA 1 were identified in the products of in vitro translation of genome RNA. Two antisera directed against fusion proteins containing sequences encoded in portions of the 3'-terminal 2.0 kb of ORF 1b were used to immunoprecipitate p90, p74, p53, p44, and p32 polypeptides. These polypeptides were clearly different in electrophoretic mobility, antiserum reactivity, and partial protease digestion pattern from viral structural proteins and from polypeptides encoded in the 5' end of ORF 1a, previously identified by in vitro translation. The largest of these polypeptides had partial protease digestion patterns similar to those of polypeptides generated by in vitro translation of a synthetic mRNA derived from the 3' end of ORF 1b. The polypeptides encoded in ORF 1b accumulated more slowly during in vitro translation than polypeptides encoded in ORF 1a. This is consistent with the hypothesis that translation of gene A initiates at the 5' end of ORF 1a and that translation of ORF 1b occurs following a frameshift at the ORF 1a-ORF 1b junction. The use of in vitro translation of genome RNA and immunoprecipitation with antisera directed against various regions of the polypeptides encoded in gene A should make it possible to study synthesis and processing of the putative coronavirus polymerase.     

The nucleotide sequence of a nematode vitellogenin gene.

The nematode, Caenorhabditis elegans, contains a family of six genes that code for vitellogenins. Here we report the complete nucleotide sequence of one of these genes, vit-5. The gene specifies a mRNA of 4869 nucleotides, including untranslated regions of 9 bases at the 5' end and 51 bases at the 3' end. Vit-5 contains four short introns totalling 218 bp. The predicted vitellogenin, yp170A, has a molecular weight of 186,430. At its N terminus it is clearly related to the vitellogenins of vertebrates. However, the vit-5-encoded protein does not contain a serine-rich sequence related to the vertebrate vitellin, phosvitin. In fact, the amino acid composition of the nematode protein is very similar to that of the vertebrate protein without phosvitin. Vit-5 has a highly asymmetric codon choice dictionary. The favored codons are different from those favored in other organisms, but are characteristic of highly expressed C. elegans genes. The strong selection against rare codons is not as great near the 5' end of the gene; rare codons are 15 times more frequent within the first 54 bp than in the next 4.8 kb.     

Ah receptor for 2,3,7,8-tetrachlorodibenzo-p-dioxin: ontogeny in chick embryo liver

Aryl hydrocarbon hydroxylase (AHH, cytochrome P1-450) is induced in chick liver very early during embryonic development if embryos are treated with 3-methylcholanthrene-type compounds such as 3,4,3'4'-tetrachlorobiphenyl. In mammals, AHH induction is known to be mediated by the Ah receptor. Liver from embryonic and newly hatched chicks was found to contain a cytosolic receptor for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) which has properties that are very similar to properties of the Ah receptor previously characterized in mammalian tissues. In chick embryo liver, cytosolic binding sites for TCDD were of high affinity (Kd for [3-H]-TCDD = 0.2 nM) and were specific for 3-methylcholanthrene-type inducers. The specific binding component sedimented at about 9S on sucrose density gradients prepared at low ionic strength. A high level of Ah receptor was detected in chick embryo liver by the fifth day of incubation (5 DI); this is at least 24 hours prior to the onset of AHH inducibility. The Ah receptor concentration increased from 5 DI to 8 DI, the period when chick liver is undergoing early morphological differentiation. After 8 DI, Ah receptor levels dropped substantially and remained low into the posthatching period. In contrast, AHH inducibility was high by 7 DI and remained high throughout embryonic development and into the posthatching period. The discrepancy between Ah receptor levels and the degree of AHH inducibility suggests that only a small fraction of the Ah receptor population is required for maximal AHH induction.     

A mutation causing Alport syndrome with tardive hearing loss is common in the western United States.

Mutations in the COL4A5 gene, located at Xq22, cause Alport syndrome (AS), a nephritis characterized by progressive deterioration of the glomerular basement membrane and usually associated with progressive hearing loss. We have identified a novel mutation, L1649R, present in 9 of 121 independently ascertained families. Affected males shared the same haplotype of eight polymorphic markers tightly linked to COL4A5, indicating common ancestry. Genealogical studies place the birth of this ancestor >200 years ago. The L1649R mutation is a relatively common cause of Alport syndrome in the western United States, in part because of the rapid growth and migratory expansion of mid-nineteenth-century pioneer populations carrying the gene. L1649R affects a highly conserved residue in the NC1 domain, which is involved in key inter- and intramolecular interactions, but results in a relatively mild disease phenotype. Renal failure in an L1649R male typically occurs in the 4th or 5th decade and precedes the onset of significant hearing loss by approximately 10 years.     

Bacterial ecology of an old-growth douglas fir canopy

Microbial populations associated with the major substrates of the canopy of a single 70 m old-growth Douglas fir were studied to determine potential activities. Seasonal samples from bark, foliage, epiphytic moss, lichens, and litter accumulations were collected to: (a) obtain population data, (b) isolate the major groups of microorganisms present, (c) measure enzymatic activities associated with cellulose and xylan degradation, and (d) examine the potential for nitrogen fixation. We tested 562 bacterial isolates for utilization of 25 compounds associated with the canopy substrates, and for activities in nitrogen and sulfur cycle transformations. Total bacterial populations, reflecting seasonal temperature and moisture conditions, were lowest on bark and foliage [21–266×10³ colony-forming units (CFU/g)] and highest on moss and lodged litter (19–610×10⁵ CFU/g). Lichens contained intermediate numbers of bacteria (3.3–270×10⁵ CFU/g). The majority of the bacteria were classified as species ofArthrobacter, Bacillus, Flavobacterium, andXanthomonas. Isolates ofAlcaligenes (Achromobacter), Aeromonas, Chromobacterium, Micrococcus, andPseudomonas were less common. No measurable rates of nitrogen fixation attributable to free-living bacteria were detected by acetylene reduction. Eleven species in six genera of lichens containing a blue-green algal phycobiont showed positive acetylene reduction. One species,Lobaria oregana, accounted for 51% of the total lichen biomass of the canopy. Cellulase and xylanase activity was routinely detected in moss and litter samples, and less frequently in lichens. There was a strong correlation between the two activities for moss (r=0.94) and litter (r=0.81).     

Exercise training in childhood-onset systemic lupus erythematosus: a controlled randomized trial

Introduction

Exercise training has emerged as a promising therapeutic strategy to counteract physical dysfunction in adult systemic lupus erythematosus. However, no longitudinal studies have evaluated the effects of an exercise training program in childhood-onset systemic lupus erythematosus (C-SLE) patients. The objective was to evaluate the safety and the efficacy of a supervised aerobic training program in improving the cardiorespiratory capacity in C-SLE patients.

Methods

Nineteen physically inactive C-SLE patients were randomly assigned into two groups: trained (TR, n = 10, supervised moderate-intensity aerobic exercise program) and non-trained (NT, n = 9). Gender-, body mass index (BMI)- and age-matched healthy children were recruited as controls (C, n = 10) for baseline (PRE) measurements only. C-SLE patients were assessed at PRE and after 12 weeks of training (POST). Main measurements included exercise tolerance and cardiorespiratory measurements in response to a maximal exercise (that is, peak VO₂, chronotropic reserve (CR), and the heart rate recovery (ΔHRR) (that is, the difference between HR at peak exercise and at both the first (ΔHRR1) and second (ΔHRR2) minutes of recovery after exercise).

Results

The C-SLE NT patients did not present changes in any of the cardiorespiratory parameters at POST (P > 0.05). In contrast, the exercise training program was effective in promoting significant increases in time-to-exhaustion (P = 0.01; ES = 1.07), peak speed (P = 0.01; ES = 1.08), peak VO₂ (P = 0.04; ES = 0.86), CR (P = 0.06; ES = 0.83), and in ΔHRR1 and ΔHRR2 (P = 0.003; ES = 1.29 and P = 0.0008; ES = 1.36, respectively) in the C-SLE TR when compared with the NT group. Moreover, cardiorespiratory parameters were comparable between C-SLE TR patients and C subjects after the exercise training intervention, as evidenced by the ANOVA analysis (P > 0.05, TR vs. C). SLEDAI-2K scores remained stable throughout the study.

Conclusion

A 3-month aerobic exercise training was safe and capable of ameliorating the cardiorespiratory capacity and the autonomic function in C-SLE patients.

Trial registration

NCT01515163.