The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Guidelines for the use and interpretation of assays for monitoring autophagy

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

A reversible posterior leukoencephalopathy syndrome

BACKGROUND AND METHODS

In some patients who are hospitalized for acute illness, we have noted a reversible syndrome of headache, altered mental functioning, seizures, and loss of vision associated with findings indicating predominantly posterior leukoencephalopathy on imaging studies. To elucidate this syndrome, we searched the log books listing computed tomographic (CT) and magnetic resonance imaging (MRI) studies performed at the New England Medical Center in Boston and Hôpital Sainte Anne in Paris; we found 15 such patients who were evaluated from 1988 through 1994.

RESULTS

Of the 15 patients, 7 were receiving immunosuppressive therapy after transplantation or as treatment for aplastic anemia, 1 was receiving interferon for melanoma, 3 had eclampsia, and 4 had acute hypertensive encephalopathy associated with renal disease (2 with lupus nephritis, 1 with acute glomerulonephritis, and 1 with acetaminophen-induced hepatorenal failure). Altogether, 12 patients had abrupt increases in blood pressure, and 8 had some impairment of renal function. The clinical findings included headaches, vomiting, confusion, seizures, cortical blindness and other visual abnormalities, and motor signs. CT and MRI studies showed extensive bilateral white-matter abnormalities suggestive of edema in the posterior regions of the cerebral hemispheres, but the changes often involved other cerebral areas, the brain stem, or the cerebellum. The patients were treated with antihypertensive medications, and immunosuppressive therapy was withdrawn or the dose was reduced. In all 15 patients, the neurologic deficits resolved within two weeks.

CONCLUSIONS

Reversible, predominantly posterior leukoencephalopathy may develop in patients who have renal insufficiency or hypertension or who are immunosuppressed. The findings on neuroimaging are characteristic of subcortical edema without infarction.

Quantitation of mRNA by the polymerase chain reaction

A method for the quantitation of specific mRNA species by the polymerase chain reaction (PCR) has been developed by using a synthetic RNA as an internal standard. The specific target mRNA and the internal standard are coamplified in one reaction in which the same primers are used. The amount of mRNA is then quantitated by extrapolating against the standard curve generated with the internal standard. The synthetic internal standard RNA consists of a linear array of the sequences of upstream primers of multiple target genes followed by the complementary sequences to their downstream primers in the same order. This quantitative PCR method provides a rapid and reliable way to quantify the amount of a specific mRNA in a sample of less than 0.1 ng of total RNA. In addition, the same internal standard RNA is used, with appropriate primer pairs, to quantitate multiple different mRNA species.

Mitochondrial DNA sequences of primates: tempo and mode of evolution

We cloned and sequenced a segment of mitochondrial DNA from human, chimpanzee, gorilla, orangutan, and gibbon. This segment is 896 bp in length, contains the genes for three transfer RNAs and parts of two proteins, and is homologous in all 5 primates. The 5 sequences differ from one another by base substitutions at 283 positions and by a deletion of one base pair. The sequence differences range from 9 to 19% among species, in agreement with estimates from cleavage map comparisons, thus confirming that the rate of mtDNA evolution in primates is 5 to 10 times higher than in nuclear DNA. The most striking new finding to emerge from these comparisons is that transitions greatly outnumber transversions. Ninety-two percent of the differences among the most closely related species (human, chimpanzee, and gorilla) are transitions. For pairs of species with longer divergence times, the observed percentage of transitions falls until, in the case of comparisons between primates and non-primates, it reaches a value of 45. The time dependence is probably due to obliteration of the record of transitions by multiple substitutions at the same nucleotide site. This finding illustrates the importance of choosing closely related species for analysis of evolutionary process. The remarkable bias toward transitions in mtDNA evolution necessitates the revision of equations that correct for multiple substitutions at the same site. With revised equations, we calculated the incidence of silent and replacement substitutions in the two protein-coding genes. The silent substitution rate is 4 to 6 times higher than the replacement rate, indicating strong functional constraints at replacement sites. Moreover, the silent rate for these two genes is about 10% per million years, a value 10 times higher than the silent rate for the nuclear genes studied so far. In addition, the mean substitution rate in the three mitochondrial tRNA genes is at least 100 times higher than in nuclear tRNA genes. Finally, genealogical analysis of the sequence differences supports the view that the human lineage branched off only slightly before the gorilla and chimpanzee lineages diverged and strengthens the hypothesis that humans are more related to gorillas and chimpanzees than is the orangutan.

Ag/AgBr/TiO2Visible Light Photocatalyst for Destruction of Azodyes and Bacteria

Ag/AgBr/TiO2 was prepared by the deposition-precipitation method and was found to be a novel visible light driven photocatalyst. The catalyst showed high efficiency for the degradation of nonbiodegradable azodyes and the killing of Escherichia coli under visible light irradiation (lambda>420 nm). The catalyst activity was maintained effectively after successive cyclic experiments under UV or visible light irradiation without the destruction of AgBr. On the basis of the characterization of X-ray diffraction, X-ray photoelectron spectroscopy, and Auger electron spectroscopy, the surface Ag species mainly exist as Ag0 in the structure of all samples before and after reaction, and Ag0 species scavenged hVB+ and then trapped eCB- in the process of photocatalytic reaction, inhibiting the decomposition of AgBr. The studies of ESR and H2O2 formation revealed that *OH and O2*- were formed in visible light irradiated aqueous Ag/AgBr/TiO2 suspension, while there was no reactive oxygen species in the visible light irradiated Ag0/TiO2 system. The results indicate that AgBr is the main photoactive species for the destruction of azodyes and bacteria under visible light. In addition, the bactericidal efficiency and killing mechanism of Ag/AgBr/TiO2 under visible light irradiation are illustrated and discussed.

Molecular cloning of a complementary DNA encoding human macrophage-specific colony-stimulating factor (CSF-1)

Complementary DNA (cDNA) clones encoding human macrophage-specific specific colony-stimulating factor (CSF-1) were isolated. One cDNA clone codes for a mature polypeptide of 224 amino acids and a putative leader of 32 amino acids. This cDNA, which was cloned in the Okayama-Berg expression vector, specifies the synthesis of biologically active CSF-1 in COS cells, as determined by a specific radioreceptor assay, macrophage bone marrow colony formation, and antibody neutralization. Most of the cDNA isolates contain part of an intron sequence that changes the reading frame, resulting in an abrupt termination of translation; these cDNA's were inactive in COS cells. The CSF-1 appears to be encoded by a single-copy gene, but its expression results in the synthesis of several messenger RNA species, ranging in size from about 1.5 to 4.5 kilobases.

Molecular cloning of the complementary DNA for human tumor necrosis factor

Tumor necrosis factor (TNF) is a soluble protein that causes damage to tumor cells but has no effect on normal cells. Human TNF was purified to apparent homogeneity as a 17.3-kilodalton protein from HL-60 leukemia cells and showed cytotoxic and cytostatic activities against various human tumor cell lines. The amino acid sequence was determined for the amino terminal end of the purified protein, and oligodeoxyribonucleotide probes were synthesized on the basis of this sequence. Complementary DNA (cDNA) encoding human TNF was cloned from induced HL-60 messenger RNA and was confirmed by hybrid-selection assay, direct expression in COS-7 cells, and nucleotide sequence analysis. The human TNF cDNA is 1585 base pairs in length and encodes a protein of 233 amino acids. The mature protein begins at residue 77, leaving a long leader sequence of 76 amino acids. Expression of high levels of human TNF in Escherichia coli was accomplished under control of the bacteriophage lambda PL promoter and gene N ribosome binding site.

A naturally occurring protective system in urea-rich cells: mechanism of osmolyte protection of proteins against urea denaturation

Trimethylamine N-oxide (TMAO) is a solute concentrated in the urea-rich cells of elasmobranchs and coelacanth to offset the damaging effects of urea on intracellular protein structure and function. On the basis of transfer free energy measurements, favorable interaction of TMAO with amino acid side chains promote protein denaturation. This effect is more than offset by highly unfavorable TMAO-peptide backbone interactions that not only oppose denaturation but also provide stabilization against denaturation by urea. By combining transfer free energies of side chains and backbone with surface area exposure in the native and unfolded states of ribonuclease T1, the transfer free energies of native and unfolded protein from water to 1 M TMAO are estimated as 1.7 and 5.9 kcal/mol, respectively. These estimates agree favorably with the respective values of 1.2 and 5.4 kcal/mol determined experimentally by Lin and Timasheff [(1994) Biochemistry 33, 12695-12701]. The unfavorable transfer free energies of native and unfolded protein from water to TMAO provides a molecular level rationale for preferential hydration of proteins by osmolytes. Promotion of denaturation by urea is found to be offset by TMAO in a manner that is roughly additive of the combined effects of both solutes. The favorable interaction of urea with the backbone provides the dominant driving force for protein unfolding by this denaturant, and the unfavorable interaction of TMAO with backbone is the dominant force opposing urea denaturation. In solutions that contain significant organic solute concentration, the ascendance of the role of the peptide backbone over that of side chains can explain many observed effects in protein denaturation and stability induced by a variety of stabilizing and destabilizing organic solutes.

Correction of deafness in shaker-2 mice by an unconventional myosin in a BAC transgene

The shaker-2 mouse mutation, the homolog of human DFNB3, causes deafness and circling behavior. A bacterial artificial chromosome (BAC) transgene from the shaker-2 critical region corrected the vestibular defects, deafness, and inner ear morphology of shaker-2 mice. An unconventional myosin gene, Myo15, was discovered by DNA sequencing of this BAC. Shaker-2 mice were found to have an amino acid substitution at a highly conserved position within the motor domain of this myosin. Auditory hair cells of shaker-2 mice have very short stereocilia and a long actin-containing protrusion extending from their basal end. This histopathology suggests that Myo15 is necessary for actin organization in the hair cells of the cochlea.

Functional isolation and characterization of human hematopoietic stem cells

Hematopoietic cells differentiate in steps marked by the acquisition or loss of specific phenotypic characteristics. Human bone marrow cells that were responsive to the early-acting cytokines Kit ligand and interleukin-3 were forced to a metabolic death. The subfraction remaining represented 1 in 10(5) bone marrow mononuclear cells, were determined to be quiescent by cell cycle analysis, and had a stem cell immunophenotype. The cells were highly enriched for long-term culture-initiating cells, were capable of secondary colony formation, and produced both myeloid and lymphoid progeny. Thus, this technically simple strategy led to the efficient purification of cells with characteristics of hematopoietic stem cells.

Association of unconventional myosin MYO15 mutations with human nonsyndromic deafness DFNB3

DFNB3, a locus for nonsyndromic sensorineural recessive deafness, maps to a 3-centimorgan interval on human chromosome 17p11.2, a region that shows conserved synteny with mouse shaker-2. A human unconventional myosin gene, MYO15, was identified by combining functional and positional cloning approaches in searching for shaker-2 and DFNB3. MYO15 has at least 50 exons spanning 36 kilobases. Sequence analyses of these exons in affected individuals from three unrelated DFNB3 families revealed two missense mutations and one nonsense mutation that cosegregated with congenital recessive deafness.

Novel method for studying mRNA phenotypes in single or small numbers of cells

Biological processes, such as growth control, are often governed by biochemical steps involving mRNA transcripts that are short-lived and have a low copy number. Furthermore, the cells involved in these processes are often available in low numbers from in vivo sources. We now report a method that is superior to in situ hybridization, RNA blot analysis, and the nuclease protection assay for the study of short-lived, low-copy-number mRNA transcripts. The method consists of a microprocedure for isolating RNA from one to a few thousand cells and two coupled enzymatic steps: reverse transcription of whole cellular RNA, followed by amplification of the cDNA by a specifically primed polymerase chain reaction to give specific cDNA fragments that can be visualized on agarose gels by ethidium bromide staining. With this method we have detected actin mRNA from a single cell, or less than 100 cRNA molecules, and have quantified differences in RNA concentrations of less than threefold. The reverse transcription reaction products can be divided for the polymerase chain reaction, and several mRNA species can be assayed simultaneously. Therefore, we call the method single-cell mRNA phenotyping. This technique is applicable to the analysis of low-copy-number growth factor transcripts in cells in culture and in vivo.

Expression of primary cilia in mammalian cells

Mammalian cells in vivo frequently express primary cilia. Although some fully differentiated cell types rarely, if ever, express them, most do, indicating that they are regular cell organelles. Their expression can also be explored in vitro, where conditions--physical and chemical, intrinsic and extrinsic--permit experimental approaches which give far greater control than in vivo. This 'state of the art' paper covers briefly the general biology of primary cilia, highlights the current situation with regard to our understanding of their relevance and importance in cell biology from various facets of our recent research, much of it in collaboration with other laboratories world-wide, and outline future work aimed at answering some basic and applied questions about them, within a context of an increasing awareness that signalling between cells is of the utmost importance in understanding proliferation control and its value in cancer research, the major remit of this unit.

Hemifacial spasm: clinical findings and treatment

Hemifacial spasm (HFS) is a peripherally induced movement disorder characterized by involuntary, unilateral, intermittent, irregular, tonic or clonic contractions of muscles innervated by the ipsilateral facial nerve. We reviewed the clinical features and response to different treatments in 158 patients (61% women) with HFS evaluated at our Movement Disorders Clinic. The mean age at onset was 48.5+/-14.1 years (range: 15-87) and the mean duration of symptoms was 11.4+/-8.5 (range: 0.5-53) years. The left side was affected in 56% instances; 5 patients had bilateral HFS. The lower lid was the most common site of the initial involvement followed by cheek and perioral region. Involuntary eye closure which interfered with vision and social embarrassment were the most common complaints. HFS was associated with trigeminal neuralgia in 5.1% of the cases and 5.7% had prior history of Bell's palsy. Although vascular abnormalities, facial nerve injury, and intracranial tumor were responsible for symptoms in some patients, most patients had no apparent etiology. Botulinum toxin type A (BTX-A) injections, used in 110 patients, provided marked to moderate improvement in 95% of patients. Seven of the 25 (28%) patients who had microvascular decompression reported permanent complications and the HFS recurred in 5 (20%). Although occasionally troublesome, HFS is generally a benign disorder that can be treated effectively with either BTX-A or microvascular decompression.

Changes in hydrolytic enzyme activities of naïve Atlantic salmon Salmo salar skin mucus due to infection with the salmon louse Lepeophtheirus salmonis and cortisol implantation

The changes in the activities of mucus hydrolytic enzymes and plasma cortisol levels were examined following infection of Atlantic salmon Salmo salar with the salmon louse Lepeophtheirus salmonis and these changes were compared with those resulting from elevated plasma cortisol. Salmon were infected at high (Trial 1; 178 +/- 67) and low (Trial 2; 20 +/- 13) numbers of lice per fish and the activities of proteases, alkaline phosphatase, esterase and lysozyme in the mucus, as well as plasma cortisol levels were determined. At both levels of infection, there were significant increases of protease activity over time (1-way K-WANOVA; Trial 1, p = 0.004; Trial 2, p < 0.001). On several sampling days, generally on later days in the infections, the mucus protease activities of infected fish were significantly higher than control fish (Student's t-tests; p < 0.05). In addition, zymography experiments demonstrated bands of proteases at 17 to 22 kDa in the mucus of infected salmon that were absent in the mucus from non-infected fish and absent in the plasma of salmon. The intensity of these protease bands increased in the mucus over the course of both infections. However, plasma cortisol levels were elevated only in the heavily infected fish from the first trial. At high infection levels (Trial 1), alkaline phosphatase activity was higher in the mucus of infected fish at all days (t-test, p < 0.05). However, at the lower infection level (Trial 2), the mucus alkaline phosphatase activity did not differ significantly between infected and non-infected fish. Esterase and lysozyme activities were very low and did not change with time nor between non-infected and infected salmon in either challenge. Mucus enzyme activities of cortisol-implanted salmon did not change over time, nor were there any differences in activities between cortisol-implanted and control salmon. The present study demonstrates biochemical changes resulting from sea lice infection of Atlantic salmon occurring at the site of host-pathogen interaction, the mucus layer. However, the origin of these enzymes, whether host or pathogen, remains to be determined.

Inhibition of 4-nitroquinoline-1-oxide-induced rat tongue carcinogenesis by the naturally occurring plant phenolics caffeic, ellagic, chlorogenic and ferulic acids

The modifying effects of dietary administration of the plant phenolic antioxidants caffeic acid (CA), ellagic acid (EA), chlorogenic acid (CGA) and ferulic acid (FA) during the initiation phase on 4-nitroquinoline-1-oxide (4-NQO)-induced tongue carcinogenesis and on the number and area of silver-stained nucleolar organizer region proteins (AgNORs), a new cell proliferation marker, of the tongue squamous epithelium were investigated in male F344 rats. Rats were fed the diet containing 500 p.p.m. CA, 400 p.p.m. EA, 250 p.p.m. CGA or 500 p.p.m. FA for 7 weeks. One week after the commencement of the diets, 4-NQO (20 p.p.m.) was administered in the drinking water for 5 weeks. Feeding of four phenolic compounds significantly reduced the incidences of tongue neoplasms (squamous cell papilloma and carcinoma) and preneoplastic lesions (hyperplasia and dysplasia) by 32 weeks, and rats fed CA or EA had no tongue neoplasms. The number and area of AgNORs per nucleus were decreased significantly by dietary treatment with these four phenolics. Thus, CA, EA, CGA and FA inhibited the tongue carcinogenesis induced by 4-NQO when they were administered concurrently with the carcinogen. These results might suggest possible application of these natural substances for cancer chemoprevention in tongue in addition to other tissues (skin, lung, liver and esophagus).

Site-specific mutagenesis of the human interleukin-2 gene: structure-function analysis of the cysteine residues

The gene encoding human interleukin-2 (IL-2) has been cloned from human spleen cells, peripheral blood lymphocytes, and the Jurkat cell line. Nucleotide sequence analysis of the gene revealed that the encoded IL-2 protein has three cysteines located at amino acid residues 58, 105, and 125 of the mature protein. Site-specific mutagenesis procedures were used to modify the IL-2 gene by changing each of the cysteine codons individually to serine codons. Substitution of serine for cysteine residues at either position 58 or 105 of the IL-2 protein substantially reduced biological activity, indicating that the cysteines at these positions are necessary for maintenance of the biologically active conformation and may therefore be linked by a disulfide bridge. The modified IL-2 protein containing a substitution at position 125 retained full biological activity, suggesting that the cysteine at this position is not involved in a disulfide bond and that a free sulfhydryl group at that position is not necessary for receptor binding.

Intracellular hyaluronan: a new frontier for inflammation?

A variety of obstacles have hindered the ultrastructural localization of hyaluronan (HA). These include a lack of adequate fixation techniques to prevent the loss of HA, the lack of highly sensitive and specific probes, and a lack of accessibility due to the masking of HA by HA-binding macromolecules such as proteoglycans and glycoproteins. Despite these problems, a number of studies, both biochemical and histochemical, have been published indicating that HA is not restricted to the extracellular milieu, but is also present intracellularly. This review focuses on the possible functions of intracellular HA, its potential relationships to extracellular HA structures, and implications for inflammatory processes.

The effect of 8 or 5 years of denosumab treatment in postmenopausal women with osteoporosis: results from the FREEDOM Extension study

The FREEDOM study and its Extension provide long-term information about the effects of denosumab for the treatment of postmenopausal osteoporosis. Treatment for up to 8 years was associated with persistent reduction of bone turnover, continued increases in bone mineral density, low fracture incidence, and a favorable benefit/risk profile.

INTRODUCTION

This study aims to report the results through year 5 of the FREEDOM Extension study, representing up to 8 years of continued denosumab treatment in postmenopausal women with osteoporosis.

METHODS

Women who completed the 3-year FREEDOM study were eligible to enter the 7-year open-label FREEDOM Extension in which all participants are scheduled to receive denosumab, since placebo assignment was discontinued for ethical reasons. A total of 4550 women enrolled in the Extension (2343 long-term; 2207 cross-over). In this analysis, women in the long-term and cross-over groups received denosumab for up to 8 and 5 years, respectively.

RESULTS

Throughout the Extension, sustained reduction of bone turnover markers (BTMs) was observed in both groups. In the long-term group, mean bone mineral density (BMD) continued to increase significantly at each time point measured, for cumulative 8-year gains of 18.4 and 8.3 % at the lumbar spine and total hip, respectively. In the cross-over group, mean BMD increased significantly from the Extension baseline for 5-year cumulative gains of 13.1 and 6.2 % at the lumbar spine and total hip, respectively. The yearly incidence of new vertebral and nonvertebral fractures remained low in both groups. The incidence of adverse and serious adverse events did not increase over time. Through Extension year 5, eight events of osteonecrosis of the jaw and two events of atypical femoral fracture were confirmed.

CONCLUSIONS

Denosumab treatment for up to 8 years was associated with persistent reductions of BTMs, continued BMD gains, low fracture incidence, and a consistent safety profile.

Massive pulmonary edema and death after prostacyclin infusion in a patient with pulmonary veno-occlusive disease

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension associated with fibrotic occlusion of the smaller pulmonary veins. Although vasodilator therapy is effective in many patients with primary pulmonary hypertension, the role of vasodilators in PVOD is unclear because of concerns about precipitating pulmonary edema. Recently, however, there have been reports of successful therapy with oral vasodilators or intravenous administration of prostacyclin in patients with PVOD. In contrast, a patient with PVOD is described who developed acute pulmonary edema and respiratory failure during low-dose prostacyclin infusion, leading to death. This report suggests that vasodilators, especially prostacyclin, must be used with extreme caution in patients with known PVOD.

Exacerbation of radiocontrast nephrotoxicity by endothelin receptor antagonism

BACKGROUND

Endothelin is a potent vasoconstrictor that has been implicated in the pathogenesis of radiocontrast nephrotoxicity. Endothelin antagonists may reduce the renal hemodynamic abnormalities following radiocontrast administration.

METHODS

One hundred fifty-eight patients with chronic renal insufficiency [mean serum creatinine +/- SD = 2.7 +/- 1.0 mg/dL (242. 3 to +/- 92.8 micromol/L)] and undergoing cardiac angiography were randomized to receive either a mixed endothelin A and B receptor antagonist, SB 290670, or placebo. All patients received intravenous hydration with 0.45% saline before and after radiocontrast administration. Serum creatinine concentrations were measured at baseline, 24 hours, 48 hours, and 3 to 5 days after radiocontrast administration. The primary end point was the mean change in serum creatinine concentration from baseline at 48 hours; the secondary end point was the incidence of radiocontrast nephrotoxicity, defined as an increase in serum creatinine of > or =0.5 mg/dL (44 micromol/L) or > or = 25% from baseline within 48 hours of radiocontrast administration.

RESULTS

The mean increase in serum creatinine 48 hours after angiography was higher in the SB 209670 group [0.7 +/- 0. 7 mg/dL (63.5 +/- 58.6 micromol/L)] than in the placebo group [0.4 +/- 0.6 mg/dL (33.6 +/- 55.1 micromol/L), P = 0.002]. The incidence of radiocontrast nephrotoxicity was also higher in the SB 209670 group (56%) compared with placebo (29%, P = 0.002). This negative effect of SB 209670 was apparent in both diabetic and nondiabetic patients. Adverse effects, especially hypotension or decreased blood pressure, were more common in the SB 209670 group.

CONCLUSIONS

In patients with chronic renal insufficiency who were undergoing cardiac angiography, endothelin receptor antagonism with SB 209670 and intravenous hydration exacerbate radiocontrast nephrotoxicity compared with hydration alone.

A comparative metabolomics study of flavonoids in sweet potato with different flesh colors (Ipomoea batatas (L.) Lam)

To study the diversity and cultivar-specific of phytochemicals in sweet potato, Liquid Chromatography-Electrospray Ionization-Mass Spectrometry was used to analyze the metabolic profiles of five sweet potato cultivars exhibiting different flesh colors: purple, yellow/orange, and white. A total of 213 metabolites, including 29 flavonoids and 27 phenolic acids, were characterized. The flavonoid profiles of the five different cultivars were distinguished using PCA, the results suggested the flesh color accounted for the observed metabolic differences. In addition to anthocyanins, quinic acids and ferulic acids were the prominent phenolic acids, O-hexoside of quercetin, chrysoeriol were the prominent flavonoids in sweet potato tubers, and they were all higher in the OFSP and PFSP than WFSP. The main differential metabolic pathways between the OFSP, PFSP and the WFSP included those relating to phenylpropanoid and flavonoid biosynthesis. This study provides new insights into the differences in metabolite profiles among sweet potatoes with different flesh colors.

Localization and physical properties experiments conducted by Spirit at Gusev Crater

The precise location and relative elevation of Spirit during its traverses from the Columbia Memorial station to Bonneville crater were determined with bundle-adjusted retrievals from rover wheel turns, suspension and tilt angles, and overlapping images. Physical properties experiments show a decrease of 0.2% per Mars solar day in solar cell output resulting from deposition of airborne dust, cohesive soil-like deposits in plains and hollows, bright and dark rock coatings, and relatively weak volcanic rocks of basaltic composition. Volcanic, impact, aeolian, and water-related processes produced the encountered landforms and materials.

Stress reinstates nicotine seeking but not sucrose solution seeking in rats

RATIONALE

Intermittent footshock stress effectively reinstates extinguished heroin-, cocaine- and alcohol-taking behaviors, but not behaviors previously maintained by food reinforcers. Here we tested further the generality of the phenomenon of stress-induced reinstatement by determining the effect of footshock on reinstatement of operant responding previously maintained by nicotine or palatable sucrose solutions.

METHODS

Groups of rats were trained to self-administer either nicotine (0.03 mg/kg per infusion, 14 days) or sucrose (10 or 30% w/v, 14-20 days). After extinction of the nicotine- or the sucrose-reinforced behaviors for 5-15 days, the rats were exposed to intermittent footshock stress (5 and 15 min, 0.8 mA) during tests for reinstatement.

RESULTS

Footshock reliably reinstated nicotine seeking after extinction of the drug-reinforced behavior. In contrast, the same parameters of footshock stress did not consistently reinstate operant responding previously maintained by sucrose solutions.

CONCLUSIONS

These and previous data suggest that stressors may be more effective stimuli for reinstatement of behaviors previously maintained by drug reinforcers as compared with non-drug reinforcers.