Comparison between semiquantitative and quantitative methods for the assessment of knee synovitis in osteoarthritis using non-enhanced and gadolinium-enhanced MRI.

OBJECTIVE: To compare different semiquantitative and quantitative methods using both non-enhanced and gadolinium-enhanced MRI techniques for the assessment of synovitis in knee osteoarthritis (OA). METHODS: Knees with end-stage clinical OA in patients undergoing total knee replacement surgery were included in this cross-sectional study. MRI was performed on all knees. Standard non-enhanced and gadolinium-enhanced sequences were acquired. Using non-enhanced MRI, we semiquantitatively assessed two features widely used as surrogates for synovitis: effusion-synovitis and Hoffa-synovitis. Using gadolinium-enhanced sequences, we semiquantitatively assessed synovial thickness. We quantitatively evaluated the total synovial volume on the gadolinium-enhanced sequences as well. We assessed the correlations of effusion-synovitis and Hoffa-synovitis with synovial thickness and volume, applying Spearman correlation analysis. The diagnostic performance of both synovitis features on non-enhanced MRI was assessed using synovial thickness on gadolinium-enhanced MRI as the reference. RESULTS: A total of 104 subjects (one knee per subject) were included. Correlations of effusion-synovitis with synovial thickness and volume were r = 0.41 and r = 0.43 (P < .001) r = 0.32 and r = 0.39 (P < .0001). CONCLUSION: Using synovial thickness assessed on gadolinium-enhanced sequences as the reference, effusion-synovitis showed superior correlations and sensitivity. Effusion-synovitis should be preferred over Hoffa-synovitis as a surrogate marker for synovial thickening, in studies of knee OA for which gadolinium-enhanced sequences are not available.

Reversible and Species-Specific Depigmentation Effects of AZD3293, a BACE Inhibitor for the Treatment of Alzheimer's Disease, Are Related to BACE2 Inhibition and Confined to Epidermis and Hair.

BACKGROUND: AZD3293 (also known as LY3314814) is a novel, potent, non-selective BACE1/BACE2 inhibitor currently in Phase 3 clinical development for the treatment of Alzheimer's disease. OBJECTIVES: The purpose of these studies was to characterize the effects, putative mechanism, and reversibility of hypopigmentation following treatment with AZD3293 in pigmented Long-Evans rats, Beagle dogs, human cell cultures, and humans. DESIGN: Nonclinical studies were conducted in Long-Evans pigmented rats, and both young and older Beagle dogs using a variety of oral dose levels of AZD3293 or AZD3839 (BACE inhibition reference compound; used in older dogs only) for dosing durations of 13 to 26 weeks. In vitro studies of normal human epidermal melanocytes and reconstituted human epidermis were also conducted. Skin biopsy data from a multiple-dose Phase 1 clinical study of AZD3293 (NCT01795339) are also reported. SETTING: Nonclinical in vivo and in vitro studies were conducted in laboratory settings in the US, Canada, and France; the multiple dose clinical study was conducted in a specialized inpatient setting in the US. PARTICIPANTS: Beagle dogs: 13-week study N=36 young (8-10 mo) animals; 39-week study N=64 young animals; and a second 13-week study N=32 older (30-32 mo) animals. Long-Evans rats: N=68 animals. Multiple-dose clinical study: only data for subjects enrolled in Part 2 of this study are included in this report (N=16). INTERVENTIONS: AZD3293 was the primary intervention used in these studies. AZD3839, a relatively BACE1-selective reference inhibitor compound was used in one group in the 13 week study in older Beagle dogs and one in vitro assessment. Finally, AZ1340, another relatively BACE1-selective reference inhibitor compound was used only in one in vitro assessment. MEASUREMENTS: Measurements for the nonclinical studies in dogs and rats included macroscopic observation and assessment of skin biopsies via histopathology, immunochemistry, and electron microscopy. Measurements for the in vitro studies included melanocyte premelanosome protein (PMEL) processing, cytotoxicity, melanin synthesis, Pmel17 labeling, and melanocyte dendricity. Measurements in the clinical study included scoring of melanin content in skin biopsies taken before and after dosing with AZD3293 over 14 days at dose levels up to 150 mg. RESULTS: Depigmentation in rats and dogs was limited to skin, hair, and mucosa with no effects on other pigmented tissues. At a cellular level depigmentation was observed within a week of treatment, whereas the appearance of depigmentation in skin and hair did not become apparent until, at earliest, 4 weeks of treatment. The depigmentation effects were reversible, not associated with degenerative or inflammatory changes, and were dose- and species-dependent in severity. Full recovery of melanization was observed at the microscopic (cellular) level and at least partial recovery was seen in the macroscopic appearance of animals by the end of the 12-week recovery period in both rats and dogs. Interestingly, no changes in melanin production or melanocyte morphology were seen in human primary melanocytes or reconstituted human epidermis in vitro. Finally, there were no changes in melanization level in skin biopsies following 12 days of daily AZD3293 treatment at doses of AZD3293 up to 150 mg/day in human subjects. CONCLUSIONS: AZD3293, a novel, potent, non-selective BACE1/BACE2 inhibitor is in development as a potentially disease-modifying treatment for Alzheimer's disease. Chronic nonclinical studies in Beagle dogs and pigmented rats showed macroscopic and microscopic hypopigmentation effects of AZD3293 that were limited to skin, hair, and mucosa. These effects were shown to be reversible in both species. Analysis of data from nonclinical and in vitro studies suggests that hypopigmentation is caused by BACE2 inhibition resulting in accumulation of a premelanosome protein fragment, which interrupts the normal production of melanin. No macroscopic or microscopic reports of hypopigmentation were observed in a Phase 1 clinical study following 13 doses of AZD3293 over 14 days at dose levels up to 150 mg/day. These data suggest that hypopigmentation is species-specific and humans appear to be least sensitive to the depigmentation effect caused by BACE2 inhibition.

The enteropathogenic E. coli effector EspH promotes actin pedestal formation and elongation via WASP-interacting protein (WIP).

Enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC and EHEC) are diarrheagenic pathogens that colonize the gut mucosa via attaching-and-effacing lesion formation. EPEC and EHEC utilize a type III secretion system (T3SS) to translocate effector proteins that subvert host cell signalling to sustain colonization and multiplication. EspH, a T3SS effector that modulates actin dynamics, was implicated in the elongation of the EHEC actin pedestals. In this study we found that EspH is necessary for both efficient pedestal formation and pedestal elongation during EPEC infection. We report that EspH induces actin polymerization at the bacterial attachment sites independently of the Tir tyrosine residues Y474 and Y454, which are implicated in binding Nck and IRSp53/ITRKS respectively. Moreover, EspH promotes recruitment of neural Wiskott-Aldrich syndrome protein (N-WASP) and the Arp2/3 complex to the bacterial attachment site, in a mechanism involving the C-terminus of Tir and the WH1 domain of N-WASP. Dominant negative of WASP-interacting protein (WIP), which binds the N-WASP WH1 domain, diminished EspH-mediated actin polymerization. This study implicates WIP in EPEC-mediated actin polymerization and pedestal elongation and represents the first instance whereby N-WASP is efficiently recruited to the EPEC attachment sites independently of the Tir:Nck and Tir:IRTKS/IRSp53 pathways. Our study reveals the intricacies of Tir and EspH-mediated actin signalling pathways that comprise of distinct, convergent and synergistic signalling cascades.

The interplay between the Escherichia coli Rho guanine nucleotide exchange factor effectors and the mammalian RhoGEF inhibitor EspH.

UNLABELLED: Rho GTPases are important regulators of many cellular processes. Subversion of Rho GTPases is a common infection strategy employed by many important human pathogens. Enteropathogenic Escherichia coli and enterohemorrhagic Escherichia coli (EPEC and EHEC) translocate the effector EspH, which inactivates mammalian Rho guanine exchange factors (GEFs), as well as Map, EspT, and EspM2, which, by mimicking mammalian RhoGEFs, activate Rho GTPases. In this study we found that EspH induces focal adhesion disassembly, triggers cell detachment, activates caspase-3, and induces cytotoxicity. EspH-induced cell detachment and caspase-3 activation can be offset by EspT, EspM2, and the Salmonella Cdc42/Rac1 GEF effector SopE, which remain active in the presence of EspH. EPEC and EHEC therefore use a novel strategy of controlling Rho GTPase activity by translocating one effector to inactivate mammalian RhoGEFs, replacing them with bacterial RhoGEFs. This study also expands the functional range of bacterial RhoGEFs to include cell adhesion and survival. IMPORTANCE: Many human pathogens use a type III secretion system to translocate effectors that can functionally be divided into signaling, disabling, and countervirulence effectors. Among the signaling effectors are those that activate Rho GTPases, which play a central role in coordinating actin dynamics. However, many pathogens also translocate effectors with antagonistic or counteractive functions. For example, Salmonella translocates SopE and SptP, which sequentially turn Rac1 and Cdc42 on and off. In this paper, we show that enteropathogenic E. coli translocates EspH, which inactivates mammalian RhoGEFs and triggers cytotoxicity and at the same time translocates the bacterial RhoGEFs EspM2 and EspT, which are insensitive to EspH, and so neutralizes EspH-induced focal adhesion disassembly, cell detachment, and caspase-3 activation. Our data point to an intriguing infection strategy in which EPEC and EHEC override cellular Rho GTPase signaling by disabling mammalian RhoGEFs and replacing them with with bacterial RhoGEFs that promote cell adhesion and survival.

Enteropathogenic and enterohaemorrhagic Escherichia coli: even more subversive elements.

The human pathogens enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) share a unique mechanism of colonization that results from the concerted action of effector proteins translocated into the host cell by a type III secretion system (T3SS). EPEC and EHEC not only induce characteristic attaching and effacing (A/E) lesions, but also subvert multiple host cell signalling pathways during infection. Our understanding of the mechanisms by which A/E pathogens hijack host cell signalling has advanced dramatically in recent months with the identification of novel activities for many effectors. In addition to further characterization of established effectors (Tir, EspH and Map), new effectors have emerged as important mediators of virulence through activities such as mimicry of Rho guanine nucleotide exchange factors (Map and EspM), inhibition of apoptosis (NleH and NleD), interference with inflammatory signalling pathways (NleB, NleC, NleE and NleH) and phagocytosis (EspF, EspH and EspJ). The findings have highlighted the multifunctional nature of the effectors and their ability to participate in redundant, synergistic or antagonistic relationships, acting in a co-ordinated spatial and temporal manner on different host organelles and cellular pathways during infection.

A new population-enrichment strategy to improve efficiency of placebo-controlled clinical trials of antidepressant drugs.

The rate-limiting factor in the discovery of novel antidepressants is the inefficient methodology of traditional multicenter randomized clinical trials (RCTs). We applied a model-based approach to a large clinical database (five RCTs in major depressive disorder (MDD), involving 1,837 patients from 124 recruitment centers) with two objectives: (i) to learn about the role of center-specific placebo response in RCT failure and (ii) to apply what is learned to improve the efficiency of RCTs by enhancing the detection of treatment effect (TE). Sensitivity analysis indicated that center-specific placebo response was the most relevant predictor of RCT failure. To reduce the statistical "noise" generated by centers with nonplausible, excessively high/low placebo responses, we developed an enrichment-window strategy. Clinical trial simulation was used to assess the enrichment strategy applied before the standard statistical analysis, resulting in an overall reduction in failure of RCTs from ~50 to ~10%.

American Academy of Pediatrics. Committee on Child Abuse and Neglect and Committee on Community Health Services. Investigation and review of unexpected infant and child deaths.

Although there is a continuing need for timely review of child deaths, no uniform system exists for investigation in the United States. Investigation of a death that is traumatic, unexpected, obscure, suspicious, or otherwise unexplained in a child younger than 18 years requires a scene investigation and an autopsy. Review of these deaths requires the participation of pediatricians and other professionals, usually as a child death review team. An appropriately constituted team should evaluate the death investigation process, review difficult cases, and compile child death statistics.

Recombinant retrovirus vectors for the expression of MHC class II heterodimers.

Class II antigens are critical in determining the fate of vascularized allografts across major histocompatibility differences. We have recently developed a new approach to induce transplantation tolerance in miniature swine by creating MHC class II antigen "molecular chimerism" in bone marrow cells of potential recipients through retrovirus-mediated gene transfer. As part of this project, the ability of a recombinant double-expression vector (ZQ32N) to express MHC class II DQA and DQB was investigated. Flow cytometry analyses of ZQ32N transfected virus-producer cells demonstrated the cell surface expression of DQa/DQb heterodimers, thus suggesting a correct transcription, translation, and transport of the swine polypeptides to the cell surface. The analyses of RNA isolated from virus particles produced from ZQ32N transfected virus-producer cells indicated the DQ sequences to be correctly packaged. However, the DQ-negative cells transduced with the ZQ32N retrovirus did not show any DQ-retrovirus surface expression. Southern and Northern blot analyses of ZQ32N transfected and transduced cells strongly suggested DNA rearrangements and deletions which could account for transgene expression loss. An analysis of transduced cell genomes suggested DNA recombinations targeted to homologous sequences within the recombinant provirus. The implications of the sequence instability in designing vectors for gene therapy of organ transplantation are discussed.

Changing patterns of illicit substance use among schizophrenic patients: 1984-1996.

Over 1,700 psychiatric emergency room visits of schizophrenic and schizoaffective patients between 1984 and 1996 were reviewed, and urine drug screens (UDS) were recorded. Illicit drug use increased significantly over the 12-year period, with a large increase for cocaine (0% to 73% of positive UDS), a decline for amphetamines (60% to 0%), and a small increase for marijuana (0% to 27%). Opiate and sedative use remained unchanged. The results support the impression that cocaine use increased dramatically among urban schizophrenic patients beginning in 1988 and continuing to the present. Furthermore, cocaine seems to have replaced amphetamines as the preferred drug of abuse among schizophrenic persons following the crack epidemic.

Schizencephaly associated with psychosis.

Schizencephaly is a rare disorder of brain development resulting in the formation of abnormal unilateral or bilateral clefts in the cerebral hemispheres. It is often accompanied by partial seizures, mental retardation, and hemiparesis. Two patients are described with clear psychotic symptoms with either unilateral or bilateral schizencephaly. The implications of the association between schizencephaly and psychosis in these patients for understanding the biology of the psychoses are discussed.

Failure to detect Borna disease virus infection in peripheral blood leukocytes from humans with psychiatric disorders.

The presence of antibodies reactive with Borna disease virus (BDV) in the sera of some patients with certain psychiatric illnesses has been taken as evidence that this veterinary neurotrophic virus may occasionally infect and cause psychiatric disorders in humans. In this paper, we report the results of our studies concerning the detection of BDV-specific RNA in blood cells from patients with psychiatric diseases. Contrary to the results obtained by others, we have found no evidence for the presence of BDV-RNA in such cells. Prior work with BDV sequences in the assay environment, together with the exquisite sensitivity of RT-PCR, may account for the sporadic appearance of false positive evidence that BDV-specific RNA is present in human blood cells.

Quantitative trait loci contributing to phencyclidine-induced and amphetamine-induced locomotor behavior in inbred mice.

Phencyclidine (PCP) and amphetamine (AMP) can induce psychotic syndromes in humans, whereas administration of these drugs to mice results in behavioral activation that is influenced by genetic factors. Quantitative trait loci (QTL) underlying genetic differences in response to PCP and AMP in mice were provisionally identified by correlating allelic variation at known marker loci in the BXD series of recombinant inbred (RI) mice and its progenitors (C57BL/6J and DBA/2J inbred strains) with the locomotor response of each strain to PCP and AMP. Total distance traveled for individual mice from each of the 26 BXD RI and two progenitor strains was measured after injections of normal saline and 7.5 mg/kg i.p. injection of PCP. This procedure was repeated after 1 week, using 5.0 mg/kg of AMP, instead of PCP. Markers significantly (p < .01) correlated with response to PCP map to murine chromosomes 1, 14, and 15. Response to amphetamine was correlated with markers mapping to chromosomes 4, 5, 6, 8, 14, and 18. Identification of the QTL underlying PCP-induced and AMP-induced behavior in mice may provide clues into the complicated genetics of psychosis in humans.

Current and emerging concepts in child abuse.

Within the three decades since Henry Kempe first popularized the concept of "the battered child syndrome," much has been learned not only about physical abuse but also neglect and sexual abuse. More recently, physicians with an interest in child abuse have expanded their focus to include child death review and other prevention strategies. Despite the increasing specialization of child abuse evaluation and management, all physicians working with children are likely to encounter child abuse in their practice. In 1994, more than 3.1 million reports of child abuse were made, of which more than 1 million had enough evidence to substantiate the allegations. Approximately one-half of all substantiated child abuse reports were for neglect. Physical abuse was involved in 21% and sexual abuse in about 11%. In 3% of the cases, the newer category of mental injury (emotional abuse/neglect) also was present. Despite the increase in the reporting of child abuse, the percentage of adults who have experienced child maltreatment (approximately 25% to 33%) probably has not changed significantly during this century. Most people who are victims of child abuse still never come to the overt attention of physicians, social workers, or other professionals, but the hidden emotional consequences have a considerable impact on the mental and medical health care systems. This article will briefly review the following three major categories of child abuse to highlight some of the thinking behind recent advances: Neglect; Physical Abuse; and Sexual Abuse. We will also discuss Prevention.

Minor physical anomalies in schizophrenia.

Using the Waldrop scale, minor physical anomalies were studied in 82 Caucasian subjects, including 41 schizophrenic and 8 bipolar adults, as well as 14 normal and 19 mentally retarded adults. An increased incidence of minor physical anomalies was found in the mentally retarded adults relative to the other groups. Consistent with previous studies, there was a trend for the total mean Waldrop score of the schizophrenic group to be higher than the mean score of the normal group. Minor physical anomalies (assessed by the Waldrop scale), however, appear to be of questionable utility in identifying "congenital" schizophrenia, at least as this putative subgroup of schizophrenia is currently conceptualized.

Quantitative trait loci mapping of three loci controlling morphine preference using inbred mouse strains.

Quantitative trait loci mapping was used to identify the chromosomal location of genes which contribute to oral morphine preference (in a two-bottle choice paradigm) of C57BL/6J mice, compared to DBA/2J mice. An F2 intercross of these two strains (606 mice) was phenotyped for morphine preference and those mice demonstrating extreme values for morphine consumption (the highest and lowest 7.7%) were genotyped for 157 murine microsatellite polymorphisms. Maximum likelihood methods revealed three loci on murine chromosomes 1, 6 and 10 which are responsible for nearly 85% of the genetic variance observed between the two parental strains.