Semi-Automatic Detection of Errors in Genome-Scale Metabolic Models.

Background: Genome-Scale Metabolic Models (GSMMs) are used for numerous tasks requiring computational estimates of metabolic fluxes, from predicting novel drug targets to engineering microbes to produce valuable compounds. A key limiting step in most applications of GSMMs is ensuring their representation of the target organism's metabolism is complete and accurate. Identifying and visualizing errors in GSMMs is complicated by the fact that they contain thousands of densely interconnected reactions. Furthermore, many errors in GSMMs only become apparent when considering pathways of connected reactions collectively, as opposed to examining reactions individually. Results: We present Metabolic Accuracy Check and Analysis Workflow (MACAW), a collection of algorithms for detecting errors in GSMMs. The relative frequencies of errors we detect in manually curated GSMMs appear to reflect the different approaches used to curate them. Changing the method used to automatically create a GSMM from a particular organism's genome can have a larger impact on the kinds of errors in the resulting GSMM than using the same method with a different organism's genome. Our algorithms are particularly capable of identifying errors that are only apparent at the pathway level, including loops, and nontrivial cases of dead ends. Conclusions: MACAW is capable of identifying inaccuracies of varying severity in a wide range of GSMMs. Correcting these errors can measurably improve the predictive capacity of a GSMM. The relative prevalence of each type of error we identify in a large collection of GSMMs could help shape future efforts for further automation of error correction and GSMM creation.

Nuclear Charge Radius of

Collinear laser spectroscopy was performed on the isomer of the aluminium isotope ^{26m}Al. The measured isotope shift to ^{27}Al in the 3s^{2}3p ^{2}P_{3/2}^{○}→3s^{2}4s ^{2}S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of ^{26m}Al, resulting in R_{c}=3.130(15) fm. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed ß decay of ^{26m}Al. Its corrected Ft value, important for the estimation of V_{ud} in the Cabibbo-Kobayashi-Maskawa matrix, is thus shifted by 1 standard deviation to 3071.4(1.0) s.

Impact of Nuclear Deformation and Pairing on the Charge Radii of Palladium Isotopes.

The impact of nuclear deformation can been seen in the systematics of nuclear charge radii, with radii generally expanding with increasing deformation. In this Letter, we present a detailed analysis of the precise relationship between nuclear quadrupole deformation and the nuclear size. Our approach combines the first measurements of the changes in the mean-square charge radii of well-deformed palladium isotopes between A=98 and A=118 with nuclear density functional calculations using Fayans functionals, specifically Fy(std) and Fy(Δr,HFB), and the UNEDF2 functional. The changes in mean-square charge radii are extracted from collinear laser spectroscopy measurements on the 4d^{9}5s ^{3}D_{3}→4d^{9}5p ^{3}P_{2} atomic transition. The analysis of the Fayans functional calculations reveals a clear link between a good reproduction of the charge radii for the neutron-rich Pd isotopes and the overestimated odd-even staggering: Both aspects can be attributed to the strength of the pairing correlations in the particular functional which we employ.

Evidence of a sudden increase in the nuclear size of proton-rich silver-96.

Understanding the evolution of the nuclear charge radius is one of the long-standing challenges for nuclear theory. Recently, density functional theory calculations utilizing Fayans functionals have successfully reproduced the charge radii of a variety of exotic isotopes. However, difficulties in the isotope production have hindered testing these models in the immediate region of the nuclear chart below the heaviest self-conjugate doubly-magic nucleus 100Sn, where the near-equal number of protons (Z) and neutrons (N) lead to enhanced neutron-proton pairing. Here, we present an optical excursion into this region by crossing the N = 50 magic neutron number in the silver isotopic chain with the measurement of the charge radius of 96Ag (N = 49). The results provide a challenge for nuclear theory: calculations are unable to reproduce the pronounced discontinuity in the charge radii as one moves below N = 50. The technical advancements in this work open the N = Z region below 100Sn for further optical studies, which will lead to more comprehensive input for nuclear theory development.

Complex landscape of alternative splicing in myeloid neoplasms.

Myeloid neoplasms are characterized by frequent mutations in at least seven components of the spliceosome that have distinct roles in the process of pre-mRNA splicing. Hotspot mutations in SF3B1, SRSF2, U2AF1 and loss of function mutations in ZRSR2 have revealed widely different aberrant splicing signatures with little overlap. However, previous studies lacked the power necessary to identify commonly mis-spliced transcripts in heterogeneous patient cohorts. By performing RNA-Seq on bone marrow samples from 1258 myeloid neoplasm patients and 63 healthy bone marrow donors, we identified transcripts frequently mis-spliced by mutated splicing factors (SF), rare SF mutations with common alternative splicing (AS) signatures, and SF-dependent neojunctions. We characterized 17,300 dysregulated AS events using a pipeline designed to predict the impact of mis-splicing on protein function. Meta-splicing analysis revealed a pattern of reduced levels of retained introns among disease samples that was exacerbated in patients with splicing factor mutations. These introns share characteristics with "detained introns," a class of introns that have been shown to promote differentiation by detaining pro-proliferative transcripts in the nucleus. In this study, we have functionally characterized 17,300 targets of mis-splicing by the SF mutations, identifying a common pathway by which AS may promote maintenance of a proliferative state.

Comprehensive database and evolutionary dynamics of U12-type introns.

During nuclear maturation of most eukaryotic pre-messenger RNAs and long non-coding RNAs, introns are removed through the process of RNA splicing. Different classes of introns are excised by the U2-type or the U12-type spliceosomes, large complexes of small nuclear ribonucleoprotein particles and associated proteins. We created intronIC, a program for assigning intron class to all introns in a given genome, and used it on 24 eukaryotic genomes to create the Intron Annotation and Orthology Database (IAOD). We then used the data in the IAOD to revisit several hypotheses concerning the evolution of the two classes of spliceosomal introns, finding support for the class conversion model explaining the low abundance of U12-type introns in modern genomes.

HINCUTs in cancer: hypoxia-induced noncoding ultraconserved transcripts.

Recent data have linked hypoxia, a classic feature of the tumor microenvironment, to the function of specific microRNAs (miRNAs); however, whether hypoxia affects other types of noncoding transcripts is currently unknown. Starting from a genome-wide expression profiling, we demonstrate for the first time a functional link between oxygen deprivation and the modulation of long noncoding transcripts from ultraconserved regions, termed transcribed-ultraconserved regions (T-UCRs). Interestingly, several hypoxia-upregulated T-UCRs, henceforth named 'hypoxia-induced noncoding ultraconserved transcripts' (HINCUTs), are also overexpressed in clinical samples from colon cancer patients. We show that these T-UCRs are predominantly nuclear and that the hypoxia-inducible factor (HIF) is at least partly responsible for the induction of several members of this group. One specific HINCUT, uc.475 (or HINCUT-1) is part of a retained intron of the host protein-coding gene, O-linked N-acetylglucosamine transferase, which is overexpressed in epithelial cancer types. Consistent with the hypothesis that T-UCRs have important function in tumor formation, HINCUT-1 supports cell proliferation specifically under hypoxic conditions and may be critical for optimal O-GlcNAcylation of proteins when oxygen tension is limiting. Our data gives a first glimpse of a novel functional hypoxic network comprising protein-coding transcripts and noncoding RNAs (ncRNAs) from the T-UCRs category.

MicroRNA-221/222 confers breast cancer fulvestrant resistance by regulating multiple signaling pathways.

Fulvestrant is a selective estrogen receptor downregulator (SERD) and highly effective antagonist to hormone-sensitive breast cancers following failure of previous tamoxifen or aromatase inhibitor therapies. However, after prolonged fulvestrant therapy, acquired resistance eventually occurs in the majority of breast cancer patients, due to poorly understood mechanisms. To examine a possible role(s) of aberrantly expressed microRNAs (miRNAs) in acquired fulvestrant resistance, we compared antiestrogen-resistant and -sensitive breast cancer cells, revealing the overexpression of miR-221/222 in the SERD-resistant cell lines. Fulvestrant treatment of estradiol (E2)- and fulvestrant-sensitive MCF7 cells resulted in increased expression of endogenous miR-221/222. Ectopic upregulation of miR-221/222 in estrogen receptor-α (ERα)-positive cell lines counteracted the effects of E2 depletion or fulvestrant-induced cell death, thus also conferring hormone-independent growth and fulvestrant resistance. In cells with acquired resistance to fulvestrant, miR-221/222 expression was essential for cell growth and cell cycle progression. To identify possible miR-221/222 targets, miR-221- or miR-222- induced alterations in global gene expression profiles and target gene expression at distinct time points were determined, revealing that miR-221/222 overexpression resulted in deregulation of multiple oncogenic signaling pathways previously associated with drug resistance. Activation of ß-catenin by miR-221/222 contributed to estrogen-independent growth and fulvestrant resistance, whereas TGF-ß-mediated growth inhibition was repressed by the two miRNAs. This first in-depth investigation into the role of miR-221/222 in acquired fulvestrant resistance, a clinically important problem, demonstrates that these two 'oncomirs' may represent promising therapeutic targets for treating hormone-independent, SERD-resistant breast cancer.

The prevention of 'dry socket' with topical metronidazole in general dental practice.

OBJECTIVE: The purpose of the study was to determine if the intra-alveolar application of topical metronidazole gel could reduce the incidence of alveolar osteitis (dry socket) following routine tooth extraction in molar and premolar extraction sites. DESIGN: This was a multicentre, double blind, randomised, placebo-controlled clinical trial. A total of 302 patients took part, of which 23 returned with alveolar osteitis. Of these, eight had received the metronidazole gel and 15 the placebo. SETTING: The study was carried out in three general dental practices by general dental practitioners working in England over the period 2000-2003. MAIN OUTCOME MEASURES: Following extraction of either a molar or premolar tooth, either a 25% metronidazole gel or KY Jelly was syringed gently into the socket. A painful post operative complication was recorded if either a dry socket was present or the patient returned with pain. RESULTS AND CONCLUSIONS: The difference in the incidence of alveolar osteitis between the placebo and the active gel groups was not significant and it was concluded that 25% topical metronidazole gel was not effective in reducing the incidence of alveolar osteitis. It was found that the incidence of alveolar osteitis reduced with increasing age and was more likely to occur in a patient with a previous history of the condition.

Communicating information on cardiopulmonary resuscitation to hospitalised patients.

AIM: The primary aim of the study was to evaluate two different methods of communicating information on cardiopulmonary resuscitation (CPR) to patients admitted to general medical and elderly care wards. The information was either in the form of a detailed information leaflet (appendix I) or a summary document (appendix II). The study examined the willingness of patients in seeking detailed information on cardiopulmonary issues. SETTING: The study was conducted over three months on a general medical ward and an acute elderly care ward in two district general hospitals. METHODS: A detailed information leaflet on CPR was provided to the nursing staff on the wards. An A4 summary document summarising the CPR decision making process and basic information on cardiopulmonary issues was placed in a folder at the foot of each bed on the elderly care ward. On the general medical ward it was displayed prominently over the head of all beds. RESULTS: Out of the 274 patients admitted to the general medical ward only two requests were received for the detailed information leaflet. On the elderly care ward there were 182 admissions but no patients or their relatives requested the leaflet. CONCLUSIONS: Availability of basic information on cardiopulmonary resuscitation to all patients is practical and does not lead to unnecessary distress or offence to patients or their carers. It makes the decision making process more transparent. Detailed information leaflets are of value for a minority of hospitalised patients.

Seabirds as indicators of changes in marine ecosystems: ecological monitoring on Machias Seal Island.

Changes in marine ecosystems can be manifested in many different ways, on different temporal and spatial scales. Seabirds are top consumers in marine foodwebs and offer opportunities to detect and assess the biological effects of changes in physical parameters (sea-surface temperature [SST], salinity, depth of thermocline etc.) of the marine ecosystem. We compare six-eight years' of data on the biology (diet, and breeding success) of four species of seabird (arctic tern Sterna paradisaea and common tern S. hirundo, which feed at the sea surface; and Atlantic puffin Fratercula antica and razorbill Alca torda, which dive 30-60 m for their prey) breeding on Machias Seal Island (MSI) in the Bay of Fundy with both our own meteorological and oceanographic measurements, and with standard measurements from conventional sources. These are compared with fisheries data on changes in the main prey of all the seabirds concerned (juvenile or '0-group' herring Clupea harengus) which are the most direct link between the seabirds and the physical properties of the marine system. We explore relationships between seabird productivity and diet, and other aspects of both herring biology (larval surveys, and fat content) and oceanography (SST data from the island, and remotely sensed data from the entrance to the Bay of Fundy). Timing of laying by puffins followed SST variation at neither the local (MSI) nor regional scales, but at the scale of the North Atlantic, following the trend of populations breeding off northern Norway. The proportion of herring in the diet of terns over 6 years varied inversely with herring larval abundance the previous fall; this relationship was not statistically significant in the puffin and razorbill. A major new finding is the considerable (approximately 50%) inter-annual variation in the energy density (fat content) of juvenile herring that are the main seabird prey; breeding success of both species of tern varied in parallel with the energy density of juvenile herring in the diet until the last two years of the study, when sandlance (Ammodytes sp.) and euphausid shrimp predominated in the diet. Our long-term research approach combines traditional population monitoring (of numbers of breeding birds) with demographic, behavioural and environmental monitoring, to provide new understanding of the marine ecosystem as well as of seabirds.

Muscarinic acetylcholine receptor compounds alter net Ca2+ flux and contractility in an invertebrate smooth muscle.

Responses of a holothurian smooth muscle to a range of muscarinic (M(1) to M(5)) acetylcholine receptor (mAChR) agonists and antagonists were surveyed using calcium (Ca(2+))-selective electrodes and a mechanical recording technique. Most of the mAChR agonists and antagonists tested increased both contractility and net Ca(2+) efflux, with M(1)-specific agents like oxotremorine M being the most potent in their action. To investigate the possible sources of Ca(2+) used during mAChR activation, agents that disrupt intracellular Ca(2+) ion sequestration [cyclopiazonic acid (CPA), caffeine, ryanodine], the phosphoinositide signaling pathway [lithium chloride (LiCl)], and L-type Ca(2+) channels (diltiazem and verapamil) were used to challenge contractions induced by oxotremorine M. These contractions were blocked by treatment with CPA, caffeine, LiCl, and by channel blockers, diltiazem and verapamil, but were unaltered by ryanodine. Our data suggest that this smooth muscle had an M(1,3,5)-like receptor that was associated with the phosphoinositide signaling pathway that relied on intracellular Ca(2+) stores, but secondarily used extracellular Ca(2+) via the opening of L-type channels.

5-Hydroxytryptamine stimulates net Ca2+ flux in the ventricular muscle of a mollusc (Busycon canaliculatum) during cardioexcitation.

Noninvasive, self-referencing calcium (Ca2+) electrodes were used to study the mechanisms by which 5-hydroxytryptamine (5-HT) affects net Ca2+ flux across the sarcolemma of myocytes from ventricular trabeculae (from a marine gastropod, Busycon canaliculatum). Treatment of isolated trabeculae with 5-HT causes a net Ca2+ efflux, which is 30% blocked by verapamil. These findings suggest that the efflux is in part the result of a previous Ca2+ influx through L-type Ca2+ channels and is due to a rapid Ca2+ extrusion mechanism inherent to the sarcolemma of these myocytes. 5-HT-induced net Ca2+ efflux is also reduced by about 40% by treatment with a sodium (Na+)-free, lithium (Li+)-substituted saline, which shuts down the Na-Ca exchanger during Ca2+ extrusion. Cyclopiazonic acid (CPA), an inhibitor of the sarcoplasmic reticulum (SR) Ca2+ ATPase, almost completely abolishes the 5-HT-induced net Ca2+ efflux, suggesting that the SR rather than the extracellular pool is the primary Ca2+ reservoir serving 5-HT-induced excitation.

The application of comparative genomic hybridization as an additional tool in the chromosome analysis of acute myeloid leukemia and myelodysplastic syndromes.

In acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) there are frequently complex karyotypes with multiple structurally altered chromosomes, many of which are marker chromosomes of unknown origin. The aim of this study was to apply comparative genomic hybridization (CGH) to cases of AML or MDS in transformation submitted for routine cytogenetic analysis to investigate whether this approach would yield any further information and, if possible, to predict which cases would benefit from CGH analysis. Nineteen cases with AML or MDS in transformation were analyzed. CGH revealed nine cases with gains or losses of chromosomal material. In six of these cases the chromosomal location of this material was not apparent from cytogenetic analysis especially when multiple markers were present. By using fluorescence in situ hybridization (FISH) with specific libraries for the chromosome regions that showed discordance between CGH and conventional cytogenetics, we were able to identify the chromosome location of material within the karyotype. In this group of six patients, four cases of an unbalanced translocation involving regions of chromosomes 5 and 17 were characterized. Three of these cases had additional abnormalities, including two cases with regions of amplification in which oncogenes are located (MYC, MLL) and one case with a dic(7;21)(p10;p10). In all six cases it was possible to characterize complex chromosomal aberrations such as derivative chromosomes, marker chromosomes, and ring chromosomes. This study demonstrates that CGH can detect true gain and loss of critical chromosome regions more accurately than conventional karyotyping in cases with very complex karyotypes, and can thus prove useful in predicting prognosis and pinpointing areas of the genome that require further study. Also, CGH can be a useful technique to identify the origin of marker chromosomes, and it can assist in choice of probes for confirmatory FISH, when there is no clue provided from the analysis of G-banded chromosomes.

Variability in measurement of radiomorphometric indices by general dental practitioners.

OBJECTIVES: To assess the variability of general dental practitioners (GDPs) in measurement of radiomorphometric indices on panoramic radiographs following basic instruction and to examine whether the variability could be reduced by more individualised instruction. METHODS: Nine GDPs measured Gonion Index (GI), Antegonion Index (AI), Mental Index (MI) and Mandibular Cortical Index (MCI) on copies of 10 panoramic radiographs following a lecture on osteoporosis and the use of radiomorphometric indices. Their measurements were related to expert-derived measurements of the same copy radiographs. Mean differences and limits of agreement (2x standard deviation of differences) were calculated for quantitative indices (GI, AI, MI) and agreement of GDPs with expert-derived MCI assessments was determined using weighted kappa. Following individualised feedback to GDPs, all measurements were repeated after 2 weeks and the statistical analysis repeated. RESULTS: There was extensive variation amongst GDPs in measurement of GI, AI and MI and in assessment of MCI. There was a general tendency of GDPs to record thicker mandibular cortices than did the experts. Limits of agreement were wide relative to the mean values of each quantitative index at both readings. Agreement of the GDPs with experts in assessment of MCI was moderate at both readings, but with a wide range in assessment. CONCLUSIONS: Variability in measuring radiomorphometric indices amongst the GDPs was high and was not predictably improved by individualised instruction. This study casts considerable doubt on the potential value of radiomorphometric indices given their lack of precision.

The pharmacology of gamma-aminobutyric acid and acetylcholine receptors at the echinoderm neuromuscular junction.

This review describes the various subtypes of gamma-aminobutyric acid (GABA) receptors found at the echinoderm neuromuscular junction (NMJ), based on pharmacological and physiological studies. The review focuses mainly on holothurian GABA receptors at the NMJ located between the radial nerve and longitudinal muscle of the body wall (LMBW) and compares them to GABA receptors described at other echinoderm NMJs. Since a primary action of GABA on the holothurian LMBW is to modulate contractile responses to the excitatory neurotransmitter, acetylcholine (ACh), the pharmacology of echinoderm nicotinic ACh receptors (nAChRs) and muscarinic ACh receptors (mAChRs) is also addressed. GABA responses have been described in the asteroids, echinoids and holothuroids but not in the other echinoderm classes. Some actions of GABA on echinoderm muscle include regulation of basal tone and spontaneous rhythmic contractions and modulation of cholinergic responses. Both GABA A and B receptor subtypes are present at the echinoderm NMJ, a feature also common to the arthropods, molluscs and chordates. Echinoderm GABA A receptors may mediate the excitatory responses to GABA. The GABA A receptor antagonist bicuculline has a paradoxical effect on contractility, stimulating large protracted contractions of the LMBW. The GABA A agonist muscimol potentiates cholinergic contractions of the holothurian LMBW. Another population of GABA receptors is inhibitory and is sensitive to the GABA B agonist baclofen and GABA B antagonists phaclofen and 2-OH-saclofen. The pre- and/or postsynaptic location of the GABA A and B receptors is not currently known. The folded GABA analogue 4-cis-aminocrotonic acid has no effect on the contractility of the holothurian LMBW so GABA C receptors are probably lacking in this preparation. Pharmacological studies have shown that distinct nAChRs and mAChRs are colocalized in numerous echinoderm muscle preparations. Most recently, nAChR agonists were used to characterize pharmacologically receptors at the holothurian LMBW that bind ACh. Nicotinic AChRs with unique pharmacological profiles are localized both pre- and postsynaptically at this NMJ, where their physiological action is to enhance muscle tone. Muscarinic agonists also have excitatory actions on the LMBW but their action is to stimulate phasic, rhythmic contractions of the muscle. The location of mAChRs at the echinoderm NMJ, however, is unknown. Since most of the studies described in the present review have used whole-mount preparations consisting largely of a combination of muscle fibers, neurons and connective tissue, it is extremely difficult to determine pharmacologically the exact location of the various receptor subtypes. Additional electrophysiological studies on isolated neurons and muscle fibers are therefore required to clearly define extra-, pre- and/or postsynaptic sites for the receptor subtypes at the echinoderm NMJ.

Persistent tubular conduction in vacuolated amphibian skeletal muscle following osmotic shock.

The transverse (T-)tubules primarily function in conducting the action potentials that initiate excitation contraction coupling in skeletal muscle but may additionally subserve longer-term roles in volume regulation, membrane fusion and other trafficking processes. Osmotic shock thus both electrically detaches the T-tubules from surface membrane ('detubulation') and produces tubular vacuolation. The present experiments separated these effects. An established, reference osmotic shock protocol that exposed muscles to Ca2+/Mg2+-Ringer and gradual cooling to 10 degrees C after 18 min in glycerol-Ringer accomplished significant detubulation (77.5+/-13.15%, mean +/- SEM; n = 4). In contrast, a test protocol conducted entirely at room temperature using Mg2+-rather than Ca2+/ Mg2+-Ringer yielded reduced (P < 0.05, post hoc Duncan's multiple range test) detubulation indices (1.67+/-1.67%, n = 6) statistically indistinguishable from findings in fibres spared osmotic shock. Yet both osmotic shocks caused a formation of closed vacuoles, demonstrated by Sulphorhodamine B trapping, that occupied statistically similar fractions of total fibre volume (reference procedure: 14.38+/-2.7%, n = 6; test procedure: 13.36+/-2.00%, n = 22) in turn higher than determinations in control fibres (P < 0.05). The findings reconcile reports associating detubulation with vacuolation in osmotically shocked muscle [S. Nik-Zainal et al. (1999) J Muscle Res Cell Motil 20: 45-53; K.N. Khan et al. (2000) J Muscle Res Cell Motil 21: 79-90] with the persistence of tubular electrical activity in extensively vacuolated amphibian fibres following fatigue [J. Lannergren and H. Westerblad (1987) Acta Physiol Scand 129: 311-318; J. Lannergren et al. (1999) J Muscle Res Cell Motil 20: 19-32]. Furthermore test protocols produced higher densities of open vacuoles (13.38+/-2.33%, n = 9) than did reference protocols (6.66+/-1.63%, n = 20) contrary to their possible involvement in the electrophysiological changes. Abolition of tubular electrophysiological activity thus either follows or is independent of tubular vacuolation whilst sharing some of its underlying osmotic mechanisms.

Creation of a mouse model for non-neurological (type B) Niemann-Pick disease by stable, low level expression of lysosomal sphingomyelinase in the absence of secretory sphingomyelinase: relationship between brain intra-lysosomal enzyme activity and central nervous system function.

Most lysosomal storage diseases result in neurodegeneration, but deficiencies in the same enzymes can also lead to syndromes without neurologic manifestations. The hypothesis that low levels of residual, intra-lysosomal enzymatic activities in the central nervous system (CNS) are protective has been difficult to prove because of inconsistencies in assays of tissue samples. Experimental correction of lysosomal enzyme deficiencies in animal models suggests that low-level enzymatic activity may reduce CNS pathology, but these results are difficult to interpret owing to the partial and transient nature of the improvements, the presence of secretory hydrolases, and other confounding factors. Using a novel transgenic/knockout strategy to manipulate the intracellular targeting of a hydrolase, we created a mouse that stably expresses low levels of lysosomal sphingomyelinase (L-SMase) in the complete absence of secretory sphingomyelinase (S-SMase). The brains of these mice exhibited 11.5-18.2% of wild-type L-SMase activity, but the cerebellar Purkinje cell layer, which is lost by 4 months of age in mice completely lacking L- and S-SMase, was preserved for at least 8 months. The L-SMase activities in other organs were 1-14% of wild-type levels, and by 8 months of age all peripheral organs had accumulated sphingomyelin and demonstrated pathological intracellular inclusions. Most importantly, L-SMase-expressing mice showed no signs of the severe neurologic disease observed in completely deficient mice, and their life span and general health were essentially normal. These findings show that stable, continuous, low-level expression of intra-lysosomal enzyme activity in the brain can preserve CNS function in the absence of secretory enzyme or other confounding factors.

17beta-estradiol vaginal tablet versus conjugated equine estrogen vaginal cream to relieve menopausal atrophic vaginitis.

OBJECTIVES: The efficacy and safety of 25-microg 17beta-estradiol vaginal tablets (Vagifem) were assessed and compared with 1.25-mg conjugated equine estrogen vaginal cream (Premarin Vaginal Cream) for the relief of menopausal-derived atrophic vaginitis, resulting from estrogen deficiency. DESIGN: In a multicenter, open-label, randomized, parallel-group study, 159 menopausal women were treated for 24 weeks with either vaginal tablets or vaginal cream. Efficacy was evaluated by relief of vaginal symptoms and concentrations of serum estradiol and follicle-stimulating hormone. Safety was monitored by the incidence of adverse events, evaluation of endometrial biopsies, and clinical laboratory results. Patients also assessed the acceptability of the study medications. RESULTS: Composite scores of vaginal symptoms (dryness, soreness, and irritation) demonstrated that both treatments provided equivalent relief of the symptoms of atrophic vaginitis. At weeks 2, 12, and 24, increases in serum estradiol concentrations and suppression of follicle-stimulating hormone were observed in significantly more patients who were using the vaginal cream than in those who were using the vaginal tablets (p < 0.001). Fewer patients who were using the vaginal tablets experienced endometrial proliferation or hyperplasia compared with patients who were using the vaginal cream. Significantly more patients who were using the vaginal tablets rated their medication favorably than did patients who were using the vaginal cream (p < or = 0.001). Patients who were receiving the vaginal tablets also had a lower incidence of patient withdrawal (10% versus 32%). CONCLUSIONS: Treatment regimens with 25-microg 17beta-estradiol vaginal tablets and with 1.25-mg conjugated equine estrogen vaginal cream were equivalent in relieving symptoms of atrophic vaginitis. The vaginal tablets demonstrated a localized effect without appreciable systemic estradiol increases or estrogenic side effects. Vaginal tablet therapy resulted in greater patient acceptance and lower withdrawal rates compared with vaginal cream therapy.