Double-blind and placebo-controlled study of lithium for adolescent bipolar disorders with secondary substance dependency

OBJECTIVE

To perform a double-blind, placebo-controlled, random assignment, parallel group, pharmacokinetically dosed study of lithium for adolescents with bipolar disorders (BP) and temporally secondary substance dependency disorders (SDD).

METHOD

Subjects were 16.3 +/- 1.2 years old and were comprehensively assessed during a 6-week outpatient protocol that included random weekly urine collection for drug assays and random and weekly serum collection for lithium levels.

RESULTS

Using both intent-to-treat (N = 25) and completer (n = 21) analyses, there were significant differences on continuous and categorical measures between the active and placebo groups for both psychopathology measures and weekly random urine drug assays. The mean scheduled weekly serum lithium level of active responders was 0.9 mEq/L. Addiction to both alcohol and marijuana was the most frequent category of SDD. Mean age at onset of BP was 9.6 +/- 3.9 years and of SDD was 15.3 +/- 1.3 years. There were multigenerational mood disorders in 96% and multigenerational SDD in 56% of families.

CONCLUSIONS

Lithium treatment of BP with secondary SDD in adolescents was an efficacious treatment for both disorders. These results warrant replication with a long-term maintenance phase. The mean 6-year interval between the onset of BP and onset of SDD strongly argues for earliest recognition of BP.

Identity of viridans streptococci isolated from cases of infective endocarditis

The oral streptococci have undergone considerable taxonomic revision in recent years but there is still little information concerning associations between the newly defined species and disease. This study examined the identities of 47 strains of oral streptococci collected from 42 confirmed cases of infective endocarditis. By means of recently described physiological schemes, the most common species identified were Streptococcus sanguis sensu stricto (31.9%), S. oralis (29.8%) and S. gordonii (12.7%). Other related species including S. mitis and "S. parasanguis" were less common. This indicates that attention should be focused on S. sanguis sensu stricto and S. oralis when considering possible pathogenic mechanisms involved in viridans streptococcal endocarditis.

Hyaluronidase induction of a WW domain-containing oxidoreductase that enhances tumor necrosis factor cytotoxicity

To determine how hyaluronidase increases certain cancer cell sensitivity to tumor necrosis factor (TNF) cytotoxicity, we report here the isolation and characterization of a hyaluronidase-induced murine WW domain-containing oxidoreductase (WOX1). WOX1 is composed of two N-terminal WW domains, a nuclear localization sequence, and a C-terminal alcohol dehydrogenase (ADH) domain. WOX1 is mainly located in the mitochondria, and the mitochondrial targeting sequence was mapped within the ADH domain. Induction of mitochondrial permeability transition by TNF, staurosporine, and atractyloside resulted in WOX1 release from mitochondria and subsequent nuclear translocation. TNF-mediated WOX1 nuclear translocation occurred shortly after that of nuclear factor-kappaB nuclear translocation, whereas both were independent events. WOX1 enhanced TNF cytotoxicity in L929 cells via its WW and ADH domains as determined using stable cell transfectants. In parallel with this observation, WOX1 also enhanced TRADD (TNF receptor-associated death domain protein)-mediated cell death in transient expression experiments. Antisense expression of WOX1 raised TNF resistance in L929 cells. Enhancement of TNF cytotoxicity by WOX1 is due, in part, to its significant down-regulation of the apoptosis inhibitors Bcl-2 and Bcl-x(L) (>85%), but up-regulation of pro-apoptotic p53 ( approximately 200%) by the ADH domain. When overexpressed, the ADH domain mediated apoptosis, probably due to modulation of expression of these proteins. The WW domains failed to modulate the expression of these proteins, but sensitized COS-7 cells to TNF killing and mediated apoptosis in various cancer cells independently of caspases. Transient cotransfection of cells with both p53 and WOX1 induced apoptosis in a synergistic manner. WOX1 colocalizes with p53 in the cytosol and binds to the proline-rich region of p53 via its WW domains. Blocking of WOX1 expression by antisense mRNA abolished p53 apoptosis. Thus, WOX1 is a mitochondrial apoptogenic protein and an essential partner of p53 in cell death.

Nature of the bleeding vessel in recurrently bleeding gastric ulcers

An unselected consecutive series of 826 patients admitted for acute upper gastrointestinal bleeding underwent urgent endoscopy. Peptic ulcers were found in 402 (49%). Of the 329 ulcer craters that could be fully examined, visible vessels were identified in 156 (47%), other stigmata of recent hemorrhage in 66, and no stigmata of recent hemorrhage in 107. One hundred twenty-nine patients with stigmata of recent hemorrhage (93 of whom had visible vessels) randomly allocated to no endoscopic treatment were observed for evidence of further bleeding. Fifty-four of the 93 patients (58%) with visible vessels rebled, compared with 2 of 36 (6%) with other stigmata of recent hemorrhage. No patient without stigmata of recent hemorrhage rebled. Twenty-seven patients in whom a visible vessel in a gastric ulcer was identified at endoscopy underwent urgent partial gastrectomy because of recurrent bleeding. The vessel identified at endoscopy was found in 26 of 27 resection specimens (96%). The arterial vessel wall protruded above the surface of the ulcer crater in 10 specimens, and clot in continuity with a breach in the vessel wall protruded in a further 10 specimens. Postoperative angiography, when technically possible, showed that the breached artery ran across the base of the ulcer in all of these specimens. Pathological changes were common in the bleeding artery and included arteritis in 24 of 29 (83%) eroded arteries found in these specimens, with aneurysmal dilatation in 14 of 27 (52%) bleeding points that could be fully examined. The ulcer had penetrated to serosa in 13 specimens (45%). The bleeding artery had a mean external diameter of 0.7 mm with a range of 0.1-1.8 mm. This study provides new information about the nature of the bleeding vessel in gastric ulcers, and some of this information is relevant in planning studies of endoscopic therapy for bleeding peptic ulcers. It validates the endoscopic identification of a visible vessel, and confirms that such identification has a high predictive value for the development of recurrent hemorrhage.

Baculovirus expression of the nucleoprotein gene of measles virus and utility of the recombinant protein in diagnostic enzyme immunoassays

A recombinant baculovirus that expresses the nucleoprotein gene of measles virus (Edmonston vaccine strain) under the transcriptional control of the polyhedrin promoter was generated. The expressed protein (B-MVN) comigrated with the authentic viral nucleoprotein as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it was phosphorylated. The B-MVN protein proved to be reactive with monoclonal antibodies in radioimmunoprecipitations, and it was immunogenic, eliciting in mice antisera that recognized the native nucleoprotein. In addition, the B-MVN protein was evaluated as a replacement source of antigen for whole virus in enzyme immunoassays (EIAs) for detection of measles virus-specific immunoglobulin M (IgM) and IgG antibodies. A capture IgM EIA with the B-MVN protein as antigen detected specific IgM antibodies in 18 (72%) acute- and all convalescent-phase specimens from 25 clinical measles cases and exceeded 99% specificity with 120 control specimens. An indirect IgG EIA with the B-MVN protein detected specific IgG antibodies in 129 of 131 (98%) serum specimens with antibodies to measles virus, and results obtained from testing 268 additional serum specimens were better correlated with measles virus-neutralizing antibodies than those obtained with a commercial EIA.

SHLD2/FAM35A co-operates with REV7 to coordinate DNA double-strand break repair pathway choice

DNA double-strand breaks (DSBs) can be repaired by two major pathways: non-homologous end-joining (NHEJ) and homologous recombination (HR). DNA repair pathway choice is governed by the opposing activities of 53BP1, in complex with its effectors RIF1 and REV7, and BRCA1. However, it remains unknown how the 53BP1/RIF1/REV7 complex stimulates NHEJ and restricts HR to the S/G2 phases of the cell cycle. Using a mass spectrometry (MS)-based approach, we identify 11 high-confidence REV7 interactors and elucidate the role of SHLD2 (previously annotated as FAM35A and RINN2) as an effector of REV7 in the NHEJ pathway. FAM35A depletion impairs NHEJ-mediated DNA repair and compromises antibody diversification by class switch recombination (CSR) in B cells. FAM35A accumulates at DSBs in a 53BP1-, RIF1-, and REV7-dependent manner and antagonizes HR by limiting DNA end resection. In fact, FAM35A is part of a larger complex composed of REV7 and SHLD1 (previously annotated as C20orf196 and RINN3), which promotes NHEJ and limits HR Together, these results establish SHLD2 as a novel effector of REV7 in controlling the decision-making process during DSB repair.

Down-regulation of WW Domain-containing Oxidoreductase Induces Tau Phosphorylation in Vitro

Numerous enzymes hyperphosphorylate Tau in vivo, leading to the formation of neurofibrillary tangles (NFTs) in the neurons of Alzheimer's disease (AD). Compared with age-matched normal controls, we demonstrated here that the protein levels of WW domain-containing oxidoreductase WOX1 (also known as WWOX or FOR), its Tyr33-phosphorylated form, and WOX2 were significantly down-regulated in the neurons of AD hippocampi. Remarkably knock-down of WOX1 expression by small interfering RNA in neuroblastoma SK-N-SH cells spontaneously induced Tau phosphorylation at Thr212/Thr231 and Ser515/Ser516, enhanced phosphorylation of glycogen synthase kinase 3beta (GSK-3beta) and ERK, and enhanced NFT formation. Also an increased binding of phospho-GSK-3beta with phospho-Tau was observed in these WOX1 knock-down cells. In comparison, increased phosphorylation of Tau, GSK-3beta, and ERK, as well as NFT formation, was observed in the AD hippocampi. Activation of JNK1 by anisomycin further increased Tau phosphorylation, and SP600125 (a JNK inhibitor) and PD-98059 (an MEK1/2 inhibitor) blocked Tau phosphorylation and NFT formation in these WOX1 knock-down cells. Ectopic or endogenous WOX1 colocalized with Tau, JNK1, and GSK-3beta in neurons and cultured cells. 17Beta-estradiol, a neuronal protective hormone, increased the binding of WOX1 and GSK-3beta with Tau. Mapping analysis showed that WOX1 bound Tau via its COOH-terminal short-chain alcohol dehydrogenase/reductase domain. Together WOX1 binds Tau via its short-chain alcohol dehydrogenase/reductase domain and is likely to play a critical role in regulating Tau hyperphosphorylation and NFT formation in vivo.

Battered pets and domestic violence: animal abuse reported by women experiencing intimate violence and by nonabused women

Women residing at domestic violence shelters (S group) were nearly 11 times more likely to report that their partner had hurt or killed pets than a comparison group of women who said they had not experienced intimate violence (NS group). Reports of threatened harm to pets were more than 4 times higher for the S group. Using the Conflict Tactics Scale, the authors demonstrated that severe physical violence was a significant predictor of pet abuse. The vast majority of shelter women described being emotionally close to their pets and distraught by the abuse family pets experienced. Children were often exposed to pet abuse, and most reported being distressed by these experiences. A substantial minority of S-group women reported that their concern for their pets' welfare prevented them from seeking shelter sooner. This seemed truer for women without children, who may have had stronger pet attachments. This obstacle to seeking safety should be addressed by domestic violence agencies.

Influence of obesity, impaired glucose tolerance, and NIDDM on LDL structure and composition. Possible link between hyperinsulinemia and atherosclerosis

The possible causes of the enhanced risk for coronary heart disease (CHD) were examined in morbidly obese women with normoglycemia, impaired glucose tolerance (IGT), and non-insulin-dependent diabetes mellitus (NIDDM) before and after gastric bypass surgery. Compared with age-matched lean women, plasma lipid and apolipoprotein concentrations of the obese women before surgery favored atherogenesis. The risk for CHD may further be exacerbated in the IGT and NIDDM groups by the prevalence of smaller and denser low-density-lipoprotein (LDL) particles. LDL size correlated negatively with plasma insulin levels independent of triglyceride levels, age, or body mass index (BMI). After surgery, BMI, plasma insulin, and triglyceride levels decreased, but LDL size increased, and LDL density decreased. Neither cholesterol nor LDL cholesterol levels were affected after surgery, but high-density-lipoprotein cholesterol was increased in all patients after surgery. Although the mechanisms underlying the changes in the properties of LDL could not be determined from this study, these changes appear to be of benefit in reducing CHD risk in these patients.

Airway involvement in ulcerative colitis

Two patients with ulcerative colitis developed progressive obstructive pulmonary disease. In one, the abnormality was a sclerosing peribronchiolitis confined to small airways, while the other demonstrated a large airway fibrotic obliterative bronchitis. A review of airway involvement in ulcerative colitis and a discussion of the possible similarity to another extraintestinal manifestation of ulcerative colitis, sclerosing cholangitis, are presented.

Lithium for prepubertal depressed children with family history predictors of future bipolarity: a double-blind, placebo-controlled study

BACKGROUND

Because of negative studies of TCAs for prepubertal major depressive disorder (PMDD) and because of the potentially high switch rate of PMDD to prepubertal bipolarity (BP), it was hypothesized that lithium would be efficacious treatment for PMDD in children who also had family history (FH) predictors of future BP.

METHODS

A double-blind, placebo-controlled, and pharmacokinetically dosed study of lithium for PMDD with FH predictors of future BP was performed. Random assignment was stratified by FH of BP-I or mania versus loaded/multigenerational (L/M) FH of MDD without BP-I or mania. Comprehensive assessments were done during a six week outpatient protocol that included weekly serum lithium levels.

RESULTS

Mean age was 10.7+/-1.2 years; 17 subjects were randomized to active and 13 to placebo; 80% had FH of BP-I or mania (40% of parents had BP-I or mania); and 20% had FH of L/M MDD. Using both intent to treat with last observation carried forward (n = 30) and completer (n = 24) analyses, there were no significant differences on continuous or categorical measures between active and placebo groups. Mean serum lithium level was 0.99+/-0.16 mEq/l. There were no significant differences between mean total daily dose or mean serum lithium levels between responders and non-responders.

LIMITATIONS

Four subjects on active drug were discontinued because of dose-limiting side effects (three were cognitive impairment). Future studies of treatment for PMDD should consider alternative drugs.

CLINICAL RELEVANCE

Lithium was not significantly more efficacious than placebo for PMDD with FH predictors of future BP.

Transforming growth factor beta1 signaling via interaction with cell surface Hyal-2 and recruitment of WWOX/WOX1

Transforming growth factor beta (TGF-beta) initiates multiple signal pathways and activates many downstream kinases. Here, we determined that TGF-beta1 bound cell surface hyaluronidase Hyal-2 on microvilli in type II TGF-beta receptor-deficient HCT116 cells, as determined by immunoelectron microscopy. This binding resulted in recruitment of proapoptotic WOX1 (also named WWOX or FOR) and formation of Hyal-2.WOX1 complexes for relocation to the nuclei. TGF-beta1 strengthened the binding of the catalytic domain of Hyal-2 with the N-terminal Tyr-33-phosphorylated WW domain of WOX1, as determined by time lapse fluorescence resonance energy transfer analysis in live cells, co-immunoprecipitation, and yeast two-hybrid domain/domain mapping. In promoter activation assay, ectopic WOX1 or Hyal-2 alone increased the promoter activity driven by Smad. In combination, WOX1 and Hyal-2 dramatically enhanced the promoter activation (8-9-fold increases), which subsequently led to cell death (>95% of promoter-activated cells). TGF-beta1 supports L929 fibroblast growth. In contrast, transiently overexpressed WOX1 and Hyal-2 sensitized L929 to TGF-beta1-induced apoptosis. Together, TGF-beta1 invokes a novel signaling by engaging cell surface Hyal-2 and recruiting WOX1 for regulating the activation of Smad-driven promoter, thereby controlling cell growth and death.

A new method for generating point mutations in bacterial artificial chromosomes by homologous recombination in Escherichia coli

Bacterial artificial chromosomes (BACs) and P1 artificial chromosomes (PACs), which contain large fragments of genomic DNA, have been successfully used as transgenes to create mouse models of dose-dependent diseases. They are also potentially valuable as transgenes for dominant diseases given that point mutations and/or small rearrangements can be accurately introduced. Here, we describe a new method to introduce small alterations in BACs, which results in the generation of point mutations with high frequency. The method involves homologous recombination between the original BAC and a shuttle vector providing the mutation. Each recombination step is monitored using positive and negative selection markers, which are the Kanamycin-resistance gene, the sacB gene and temperature-sensitive replication, all conferred by the shuttle plasmid. We have used this method to introduce four different point mutations and the insertion of the ss-galactosidase gene in a BAC, which has subsequently been used for transgenic animal production.

Molecular mechanisms underlying WOX1 activation during apoptotic and stress responses

Human WWOX gene encodes a putative tumor suppressor WW domain-containing oxidoreductase WOX1 (also known as WWOX or FOR). A high frequency of loss of heterozygosity (LOH) of this gene has been shown in prostate, lung, breast and other cancers. In addition, numerous aberrant WWOX mRNA transcripts have been found in cancer cells. WOX1 is a proapoptotic protein. In response to stress or apoptotic stimuli, WOX1 became phosphorylated at Tyr33, which enabled its complex formation with activated p53 and JNK1. The p53/WOX1 complex translocated to the mitochondria and further to the nuclei to mediate apoptosis. WOX1 mutants, which were inactivated for nuclear translocation or Tyr33 phosphorylation, failed to induce apoptosis, indicating that activation of WOX1 via Tyr33 phosphorylation, followed by nuclear translocation, is essential for inducing cell death. WOX1 induced apoptosis synergistically with p53. In contrast, transiently activated JNK1 induced anti-apoptotic response, and this protective activity inhibited WOX1-induced apoptosis. Taken together, WOX1 is involved in stress and apoptotic responses, and is likely to regulate the activation of both p53 and JNK1.

Experimental measles. II. Infection and immunity in the rhesus macaque

Measles infection and the host immune response to measles virus was compared using naive and immunized rhesus monkeys. The monkeys were experimentally challenged with a wild-type strain of measles virus inoculated intranasally. After pathogenic virus challenge, measles virus was detected in mononuclear cells of peripheral blood, lymph node, and spleen in naive monkeys and viremia peaked on Day 7. However, only one of five vaccinated monkeys had a lower virus titer in peripheral blood mononuclear cells at one time point after challenge. No virus was detected in the lymphoid tissues from an immunized monkeys that was euthanized on Day 7 of infection. Measles-specific IgM, IgG, neutralizing antibody, and cytotoxic T lymphocytes were detected in vaccinated monkeys before challenge, but antibody titers were significantly lower in immunized monkeys than in naive monkey after challenge. Measles-specific IgG antibody and cytotoxic T cell responses were still detected more than 1 year after vaccination or infection. This animal model is useful for the further study of measles pathogenesis, immunosuppression, and immunologic memories.

An exploratory randomized controlled trial comparing telephone and hospital follow-up after treatment for colorectal cancer

AIM

Following treatment for colorectal cancer it is common practice for patients to attend hospital clinics at regular intervals for routine monitoring, although debate persists on the benefits of this approach. Nurse-led telephone follow-up is effective in meeting information and psycho-social needs in other patient groups. We explored the potential benefits of nurse-led telephone follow-up for colorectal cancer patients.

METHOD

Sixty-five patients were randomized to either telephone or hospital follow-up in an exploratory randomized trial.

RESULTS

The telephone intervention was deliverable in clinical practice and acceptable to patients and health professionals. Seventy-five per cent of eligible patients agreed to randomization. High levels of satisfaction were evident in both study groups. Appointments in the hospital group were shorter (median 14.0 min, range 2.3-58.0) than appointments in the telephone group (median 28.9 min, range 6.1-48.3). Patients in the telephone arm were more likely to raise concerns during consultations.

CONCLUSION

Historical approaches to follow-up unsupported by evidence of effectiveness and efficiency are not sustainable. Telephone follow-up by specialist nurses may be a feasible option. A main trial comparing hospital and telephone follow-up is justified, although consideration needs to be given to trial design and practical issues related to the availability of specialist nurses at study locations.

Activation of human matrix metalloproteinase 2 by gingival crevicular fluid and Porphyromonas gingivalis

AIM

To assess the potential of gingival crevicular fluid (GCF) from adult periodontitis patients and Porphyromonas gingivalis proteases to activate matrix metalloproteinase 2 (MMP-2) in vitro.

MATERIAL AND METHODS

GCF samples were collected from each of 15 adult periodontitis patients, from a clinically healthy site, a deep (>6 mm) bleeding site, and a deep nonbleeding site. The GCF samples were examined for general proteolytic activity, gelatinolytic activity and ability to activate pro-MMP-2 by zymography. Ultrasonic extracts of a range of clinical isolates of P. gingivalis cells and purified arg- and lys-gingipains were also assessed for their ability to activate pro-MMP-2.

RESULTS

GCF from deep nonbleeding sites showed higher general proteolytic activity than samples from deep bleeding and healthy sites but this did not reach statistical significance. Pefabloc, a general serine protease inhibitor, inhibited the majority (92%) of the proteolytic activity. GCF samples contained neutrophil MMP-9 in its latent form in 93% of the samples, and in its activated form in 40% of the samples. In contrast, MMP-2 was present in only trace amounts in 9% of the samples. When latent MMP-2 was added to these GCF samples, it was converted to the activated form (59 kDa) in 68% of the samples. Lower molecular weight (55 and 45 kDa) activated forms also appeared in 53% of the samples, particularly those from deep sites. Activation to the 55 and 45 kDa forms was inhibited by MSAAPket (a neutrophil elastase inhibitor), whereas Pefabloc completely inhibited the activation of latent MMP-2. All ultrasonic extracts of P. gingivalis activated latent MMP-2 in a concentration- and time-dependent manner. Also, latent MMP-2 was activated by purified arg-gingipain but less efficiently by lys-gingipain.

CONCLUSION

These findings suggest that P. gingivalis arg-gingipain and neutrophil elastase present in GCF can activate latent MMP-2, which may contribute in vivo to local periodontal tissue destruction.

Appearance of functional insulin receptors during the differentiation of embryonal carcinoma cells

The insulin-receptor binding activity and insulin-stimulated growth response of PC13 clone 5 cells were investigated for both the embryo carcinoma (EC) and retinoic acid-induced differentiated derivatives of this cell line. Whereas the EC cell was found to have very few, if any, receptors and showed no demonstrable dependence on insulin for growth, the differentiated derivative cell expressed a large number of insulin receptors and, when challenged with the hormone, showed stimulation of both DNA synthesis and cell division. The same data were obtained for five independent PC13 clones. These results, coupled with previous observations, lend weight to the suggestion that the appearance of specific receptors for growth regulatory substances may be a manifestation of a general change in growth-regulatory mechanisms accompanying EC cell differentiation and loss of malignancy.

A General Synthetic Approach for Designing Epitope Targeted Macrocyclic Peptide Ligands

We describe a general synthetic strategy for developing high-affinity peptide binders against specific epitopes of challenging protein biomarkers. The epitope of interest is synthesized as a polypeptide, with a detection biotin tag and a strategically placed azide (or alkyne) presenting amino acid. This synthetic epitope (SynEp) is incubated with a library of complementary alkyne or azide presenting peptides. Library elements that bind the SynEp in the correct orientation undergo the Huisgen cycloaddition, and are covalently linked to the SynEp. Hit peptides are tested against the full-length protein to identify the best binder. We describe development of epitope-targeted linear or macrocycle peptide ligands against 12 different diagnostic or therapeutic analytes. The general epitope targeting capability for these low molecular weight synthetic ligands enables a range of therapeutic and diagnostic applications, similar to those of monoclonal antibodies.

The role of immunoglobulin G and fibrinogen in platelet aggregation by Streptococcus sanguis

Previous work has shown that the type strain of Streptococcus sanguis, NCTC 7863, induces aggregation of normal platelets by a complement-dependent mechanism. We investigated the roles of IgG and fibrinogen in the aggregation process. Plasma depleted of IgG by passage through protein A-sepharose failed to support platelet aggregation, as did plasma absorbed at 0 degrees C with whole bacteria. However, absorption of plasma with a non-aggregating strain of S. sanguis, SK96, did not remove aggregating activity for NCTC 7863. Supplementing 0 degrees C-absorbed plasma with purified IgG restored the aggregation supporting activity. A monoclonal antibody to the Fc gammaRII receptor inhibited platelet aggregation by the bacteria, indicating a requirement for bacteria-IgG complexes interacting with the Fc receptor in platelet aggregation. There was a lag time to the onset of platelet aggregation of 7-19 min depending upon the platelet donor, but the length of this lag did not correlate with either total IgG concentration recognizing NCTC 7863 in subjects' plasma, or the concentration any of the four IgG subclasses or with IgG avidity levels. Fibrinogen was shown to bind rapidly to the bacterial cell surface. Monoclonal antibody to GPIIb/IIIa, RGDS peptide, and a specific antagonist for the platelet fibrinogen receptor, GPIIb/IIIa, FK633, inhibited platelet aggregation by NCTC 7863, indicating that platelet aggregation is fibrinogen dependent. These data suggest that platelet aggregation by some strains of S. sanguis requires multiple stimuli/agonists, including IgG-Fc receptor interaction, complement and fibrinogen.

Toxicologic effects of an oligodeoxynucleotide phosphorothioate and its analogs following intravenous administration in rats

The aim of the present study is to evaluate the in vivo toxicologic effects of a phosphorothioate oligodeoxynucleotide (PS oligo) and three of its analogs [PS oligo containing four methylphosphonate linkages at the 3' and 5'-ends (MBO 1), PS oligo containing four 2'-O-methylribonucleosides at both the 3'- and 5'-ends (MBO 2), and PS oligo containing an 8 bp loop region at the 3'-end (self-stabilized oligo)]. Oligodeoxynucleotides were administrated intravenously to male and female rats at doses of 3, 10, and 30 mg/kg/day for 14 days. Rats were killed on day 15, blood samples were collected for hematology and clinical chemistry determinations, and tissues, including lymph nodes, spleens, livers, and kidneys, were subjected to pathologic examinations. The toxicity profiles of the four oligodeoxynucleotides were very similar, but differed in magnitude. In terms of the severity of the abnormalities caused by the oligodeoxynucleotides, the order was MBO 2 > PS oligo > self-stabilized oligo > MBO 1. Alterations in hematology parameters included thrombocytopenia, anemia, and neutropenia. Abnormalities in clinical chemistry parameters observed with PS oligo or MBO 2 were dose-dependent elevation of liver transaminases and reduction of the levels of alkaline phosphatase, albumin, and total protein. In addition, MBO 2 caused elevation of the total bilirubin level in male rats at the 30 mg/kg dose. No major alterations in hematology or clinical chemistry were observed in rats receiving MBO 1 or self-stabilized oligo. Dose-dependent enlargements of spleen, liver, and kidney were observed, especially in rats receiving PS oligo and MBO 2. Pathologic studies showed a generalized hyperplasia of the reticuloendothelial (RE) system in the tissues examined. Alterations in the spleen were mainly RE cell hyperplasia and hematopoietic cell proliferation. In addition to RE cell hyperplasia, lymph nodes showed necrosis, hepatocytes showed cytologic alterations and necrosis, and kidneys showed renal tubule regeneration. The severity of pathologic changes observed was oligodeoxynucleotide dependent, in the order of MBO 2 > PS oligo > self-stabilized oligo > MBO 1.

Are Randomized Controlled Trials the (G)old Standard? From Clinical Intelligence to Prescriptive Analytics

Despite the accelerating pace of scientific discovery, the current clinical research enterprise does not sufficiently address pressing clinical questions. Given the constraints on clinical trials, for a majority of clinical questions, the only relevant data available to aid in decision making are based on observation and experience. Our purpose here is 3-fold. First, we describe the classic context of medical research guided by Poppers' scientific epistemology of "falsificationism." Second, we discuss challenges and shortcomings of randomized controlled trials and present the potential of observational studies based on big data. Third, we cover several obstacles related to the use of observational (retrospective) data in clinical studies. We conclude that randomized controlled trials are not at risk for extinction, but innovations in statistics, machine learning, and big data analytics may generate a completely new ecosystem for exploration and validation.

Vision screening in children by Plusoptix Vision Screener compared with gold-standard orthoptic assessment

BACKGROUND/AIMS

To evaluate a new autorefractor, the Plusoptix Vision Screener (PVS), as a screening tool to detect risk factors for amblyopia by comparing it with gold-standard orthoptic vision screening in children.

METHODS

Community-based screening study including 288 children age 4-7 years who were screened with the PVS and by orthoptic assessment (distance acuity, cover test, extraocular movements, 20 PD prism test, Lang stereotest). Follow-up comprehensive eye examination of screening-positive children included manual cycloplegic retinoscopy.

RESULTS

Testability was high for both methods. Orthoptic screening identified 36 children with reduced vision and/or factors associated with amblyopia (referral rate 12.5%). The PVS identified 16 children with potential vision problems (referral rate 5.6%), indicating only moderate sensitivity (44%; 95% CI 27.9 to 61.9%), but high specificity (100%; 95% CI 98.5 to 100%) to detect factors associated with amblyopia. The PVS underestimated visually significant refractive errors.

CONCLUSIONS

Use of the PVS as single screening test in young children may miss a significant number of children with amblyopia or amblyogenic risk factors.