Safety of tacrolimus in patients with rheumatoid arthritis: long-term experience.

OBJECTIVE: To evaluate the long-term safety of tacrolimus 3 mg/day in patients with rheumatoid arthritis (RA). METHODS: Patients with active RA who had discontinued all DMARDs for at least 2 weeks and had at least five tender/painful joints and three swollen joints, and required DMARD treatment in the opinion of the investigator, were enrolled into this open-label long-term safety trial. In addition, patients who had completed at least 3 months of treatment with tacrolimus 2 mg/day, tacrolimus 3 mg/day or placebo in a Phase III double-blind efficacy trial were allowed to roll over into this study. This latter group of patients did not have to fulfil any joint count requirements prior to entry into the long-term safety study, provided that no more than 14 days had elapsed between the end of their participation in the double-blind study and screening for the long-term safety study. All patients enrolled received tacrolimus 3 mg/day in addition to their current regimen of NSAIDs and corticosteroids. RESULTS: 896 patients received at least one dose of tacrolimus 3 mg. The median duration of treatment was 359 days. 145 patients (16.2%) withdrew from the study for adverse events possibly or probably related to tacrolimus, 33 patients (3.7%) withdrew from the study for adverse events unrelated to tacrolimus and 112 (12.5%) withdrew for lack of efficacy. No adverse event with an incidence >0.7% appeared for the first time after the first 3 months of treatment with 3 mg tacrolimus. 529 patients (59%) experienced an adverse event that was possibly or probably related to tacrolimus; the most common were diarrhoea (14.6%), nausea (10.3%), tremor (9.0%), headache (8.7%), abdominal pain (7.9%), dyspepsia (7.6%), increased creatinine (6.8%) and hypertension (5.4%). Twenty-four patients (2.7%) experienced serious adverse events possibly or probably related to study drug; the most common were pneumonia (0.6%), hyperglycaemia (0.3%), gastroenteritis (0.2%), pancreatitis (0.2%) and diabetes mellitus (0.2%). The mean creatinine level increased from 67+/-19 micromol/l (0.76+/-0.22 mg/dl) at baseline to 75+/-26 micromol/l (0.85+/-0.30 mg/dl) (P<0.0001) at end of treatment. 351 (40.3%) of the 872 patients for whom creatinine levels were available at both baseline and during treatment had > or =30% increase from baseline in serum creatinine during the study, either related or unrelated to tacrolimus, with 73 patients (8.4%) having creatinine levels exceeding the normal range. At end of treatment, 177 patients (20.3%) had a > or =30% increase from baseline in creatinine. Serum creatinine remained within the normal range throughout the trial in approximately 90% of patients. At the end of treatment, the ACR20, ACR50 and ACR70 response rates were 38.4%, 18.6% and 9.0% respectively. Over 26% of patients had at least a 70% improvement in both swollen and painful/tender joints. CONCLUSION: This study demonstrates that tacrolimus was safe and well-tolerated and provided clinical benefit over a period of at least 12 months.

Carbon hydroxylation of alkyltetrahydropyranols: a paradigm for spiroacetal biosynthesis in Bactrocera sp.

[figure: see text] In a number of Bactrocera species the penultimate step in the biosynthesis of spiroacetals is shown to be the hydroxylation of an alkyltetrahydropyranol followed by cyclization. The monooxygenases that catalyze this side chain hydroxylation show a strong preference for oxidation four carbons from the hemiketal center, to produce the spiroacetal. The hydroxy spiroacetals observed in Bactrocera appear to derive from direct oxidation of the parent spiroacetals and not from alternate precursors.

Neurophysiologic mechanisms of attention: a selective review of early information processing in schizophrenics.

Attention is an integral component of information processing. A pronounced attention deficit exists among people with schizophrenia and their first-degree relatives as compared to persons without this pathology. Schizophrenics demonstrate marked deficiencies on psychophysical tasks that require temporal and / or spatial integration, properties that are associated with the two primary visual pathways composed of magnocellular (M) and parvocellular (P) cells, respectively. The deficit expresses itself as a dysfunctional information processing system that affects higher order processes, for example, perceptual ability and memory. The focus of this review is to integrate results from several divergent areas of research to include those studies that identify the contributions of the M and P pathways associated with information processing and the attention deficit. The diverse approaches reviewed in this chapter converge to provide a neurophysiologic explanation of the attention deficit in schizophrenia.

Neurophysiologic mechanisms of attention deficits in schizophrenia.

BACKGROUND: Despite advances in the pharmacologic treatment of schizophrenia, the neurophysiologic mechanism(s) of disordered attention in schizophrenia remain elusive. OBJECTIVE: The goal of the present study was to assess specific components of attention, including disengagement, movement, re-engagement, and the inhibitory processes involved their control. METHODS: Thirteen chronic schizophrenics from the inpatient and outpatient units of the Veterans Administration Medical Center (New Orleans, LA) and thirteen normal control subjects were administered a saccadic eye movements task. Saccade latency was measured in the presence of contra-lateral distracter stimuli that preceded the target onset (Distracter-before), followed the target onset (Distracter - after) or in the absence of a distracter (No-distracter). In order to assess the interactive process of fixation disengagement and target selection, fixation was either offset before the target (Gap) or it remained on in the presence of the target (Overlap). RESULTS: Repeated measures analysis of variance revealed that saccadic latency in patients with schizophrenia is prolonged to a greater extent than in normal control subjects in the presence of distracter stimuli. Patients with schizophrenia are also characterized by a greater percentage of error saccades directed to the distracter, and require a longer latency to "issue" corrective saccades following error saccades. CONCLUSIONS: The findings suggest that patients with schizophrenia are required to invoke volitional control under distracter conditions, whereas normal control subjects require minimal volitional control. The results are interpreted in terms of the inhibitory mechanisms that regulate attention.

Smooth pursuit tracking deficits of patients with schizophrenia at specific within-sine wave bins.

BACKGROUND: Early information processing deficits are consistently reported for patients with schizophrenia on smooth pursuit tracking tasks. A growing number of studies have applied a transient (magnocellular) or sustained (parvocellular) explanation to account for deficient processing of briefly presented visual stimuli, moving stimuli, and particularly, stimuli requiring smooth tracking eye movements in patients with schizophrenia. OBJECTIVE: Although the preponderance of findings offer support for transient (where is it?) as opposed to sustained (what is it?) deficit, a need remains for specific depiction of the deficit. This was accomplished by applying a unique analytic method to a smooth pursuit tracking task. METHODS: Fourteen patients with schizophrenia and fifteen normal control subjects were tested on smooth pursuit tracking performance at five different "within-wave" dot velocity frequencies that ranged from .3 to 1.1 hz. Performance data was extracted from each of the five frequencies and then separated into 12 discrete components that corresponded to light velocity (i.e., 12 bins). RESULTS: A repeated measures multivariate analysis of covariance indicated that the performance of patients with schizophrenia was significantly poorer than that of their normal counterparts for three separate analyses of the time in smooth pursuit, F(11,594) = 8.99; p <0.00001, percentage of time in smooth pursuit, F(11,594) = 3.06; p <0.0005, and time in saccade eye movement, F(11,594) = 3.11; p <0.0004. A regression analysis revealed that the medication dosage was not significantly associated with performance on any of the critical measures, although trends were observed. CONCLUSIONS: The findings provide support for an early information processing deficit in patients with schizophrenia. In addition, the results support the current neurophysiologic model for abnormal smooth pursuit tracking in patients with schizophrenia, specifically implicating a transient channel deficiency.

High velocity transient visual processing deficits diminish ability of patients with schizophrenia to recognize objects.

OBJECTIVE: Early information processing deficits are consistently reported for patients with schizophrenia. A growing number of studies have applied a transient (magnocellular) or sustained (parvocellular) explanation to account for deficient processing of briefly presented visual stimuli, moving stimuli, and stimuli requiring eye movements in patients with schizophrenia. This reasoning is based on research that makes the distinction between a magnocellular channel, which primarily responds to low spatial frequency and moving or rapidly presented visual information, and a parvocellular channel, which is primarily responsive to high spatial frequency and detailed information. BACKGROUND: Although the preponderance of findings offer support for transient ("where is it") as opposed to sustained ("what is it") deficit in patients with schizophrenia, there remains a need for more specific depiction of the deficit. METHOD: The present study evaluated normal control subjects and patients with schizophrenia recruited from in-patient and out-patient settings. A Motion Defined Letter task was used, owing to its sensitivity to transient (magnocellular) activation. RESULTS: Twenty-three patients with schizophrenia and sixteen normal control subjects were tested on eight dot velocity levels, ranging from 88 arc min/sec to 0.69 arc min/sec. A repeated measures analysis of variance indicated that the performance of patients with schizophrenia was significantly poorer than that of their normal counterparts on the three fastest dot velocity conditions (88 arc min/sec, p < 0.0001, 44 arc min/sec, p < 0.00001, and 22 arc min/sec, p < 0.00003), but performance did not differ on the five slower dot velocity conditions. A regression analysis revealed that the dosage of medication was positively associated with performance on three middle range dot velocity conditions (11 arc min/sec F (1,22) = 6.99; p < 0.025; 5.5 arc min/sec, F (2,20) = 0.379; p = 0.05, and 2.25 arc min/sec F (2,20) = 7.37; p < 0.005). CONCLUSIONS: The findings afford support for an early information processing deficit in schizophrenics. These data also support the neurophysiologic model that explains the poor performance of patients with schizophrenia as it relates to a transient channel deficiency.

Antiretroviral antibodies: implications for schizophrenia, schizophrenia spectrum disorders, and bipolar disorder.

BACKGROUND: Some retroviral antigens share structural homology within a group of related retroviruses. It is possible that antibodies directed against one virus may cross-react with antigens from a different virus in the group. METHODS: Using this principle, the human immunodeficiency virus 1 (HIV-1) Western blot assay was used as an available source of human retroviral antigens to screen serum samples from an archived collection to ascertain whether there was an association between serum antiretroviral antibodies and mental illnesses. RESULTS: A statistically significant proportion (28/54, 52%) of patients suffering from psychiatric disorders had serum antibodies that recognized at least one antigen present on the blot, culminating in indeterminate HIV-1 tests. The majority of the reactive samples were directed against the HIV-1 group antigens p24 and p17. These findings contrast with those of nonpsychiatric patients, who had 4/16 (25%) indeterminate blots. CONCLUSIONS: The results suggest exposure to retroviral antigens related to those of HIV-1 in subpopulations of schizophrenic, schizophrenic spectrum disorder, and bipolar disorder patients.

Preliminary study of the safety and efficacy of SC-58635, a novel cyclooxygenase 2 inhibitor: efficacy and safety in two placebo-controlled trials in osteoarthritis and rheumatoid arthritis, and studies of gastrointestinal and platelet effects.

OBJECTIVE: To investigate the efficacy and safety of SC-58635 (celecoxib), an antiinflammatory and analgesic agent that acts by selective cyclooxygenase 2 (COX-2) inhibition and is not expected to cause the typical gastrointestinal (GI), renal, and platelet-related side effects associated with inhibition of the COX-1 enzyme. METHODS: Four phase II trials were performed: a 2-week osteoarthritis efficacy trial, a 4-week rheumatoid arthritis efficacy trial, a 1-week endoscopic study of GI mucosal effects, and a 1-week study of effects on platelet function. RESULTS: The 2 arthritis trials identified SC-58635 dosage levels that were consistently effective in treating the signs and symptoms of arthritis and were distinguished from placebo on standard arthritis scales. In the upper GI endoscopy study, 19% of subjects receiving naproxen (6 of 32) developed gastric ulcers, whereas no ulcers occurred in subjects receiving SC-58635 or placebo. The study of platelet effects revealed no meaningful effect of SC-58635 on platelet aggregation or thromboxane B2 levels, whereas aspirin caused significant decreases in 2 of 3 platelet aggregation measures and thromboxane B2 levels. In all 4 trials, SC-58635 was well tolerated, with a safety profile similar to that of placebo. CONCLUSION: SC-58635 achieves analgesic and antiinflammatory efficacy in arthritis through selective COX-2 inhibition, without showing any evidence of 2 of the toxic effects of COX-1 inhibition associated with nonsteroidal antiinflammatory drugs.

A peptidomimetic that specifically inhibits human leukocyte antigen DRB1*0401-restricted T cell proliferation.

The ability of a peptidomimetic (SC-67655) to block the peptide binding site of the rheumatoid arthritis-linked human leukocyte antigen encoded by the DRB1*0401 allele was evaluated. The inhibitor bound to purified DRB1*0401 molecules with an affinity similar to that of the well-characterized peptide ligand HA307-319. Cell binding assays demonstrated that, in contrast to the promiscuous HA307-319 peptide, the peptidomimetic was highly specific for DRB1*0401. The inhibitor also blocked functional T cell responses to peptide antigens but did not block T cell proliferation in response to protein antigens. Furthermore, it did not appear to be taken up by cells. An analog of the peptidomimetic that was conjugated to a signal peptide sequence did inhibit a T cell proliferative response to protein antigen. Thus, the peptidomimetic must be taken up by cells to block the presentation of peptides derived from protein antigens. These findings have implications for the rational development of inhibitors that block the class II peptide binding groove for the treatment of autoimmune diseases.

Clinical and histological assessment of collagen-induced arthritis progression in the diabetes-resistant BB/Wor rat.

Collagen-induced arthritis in the diabetes-resistant BB (DR BB)/Wor rat is a severe, aggressive disease initiated by immunization with heterologous native Type II collagen. Onset of clinical symptoms reproducibly occurs in 100% of animals between days 10 and 12 following collagen immunization. Hypertrophy of the synovial lining is the first histological manifestation of the early inflammatory arthritis. A mild inflammatory infiltrate in the synovium rapidly becomes a fibrovascular pannus eroding articular cartilage and subchondral bone. Beginning at the joint margins, an active synovitis is present. Light microscopy and immunohistochemical staining show the infiltrate to be comprised of mononuclear (lymphocytes, macrophages) and polymorphonuclear inflammatory cells. In addition, there is histological evidence for chronic inflammatory nodules and necrotizing vasculitis in connective tissue from diseased joints, both morphologic features associated with rheumatoid arthritis in humans. Subchondral bone erosion appears to be mediated largely by the resorptive action of activated osteoclasts. These histological parameters of disease progression in the DR BB/Wor rat are similar to human rheumatoid arthritis. The extensive degree of similarity in the pathology of DR BB/Wor rat collagen-induced arthritis and human rheumatoid arthritis supports the role of this model as an in vivo disease model for human rheumatoid arthritis.

Attentional mechanisms of saccadic eye movements in schizophrenia.

Saccadic latency of schizophrenics (N = 15) and normal controls (N = 11) was measured to the left and right visual fields with three fixation conditions that differentially affect saccade latency. Fixation was offset either 1) prior to the target (gap condition), 2) simultaneous with the target onset (control condition), or 3) after target onset (overlap condition). Saccade latencies are typically reduced in the gap condition, which is attributed to the fixation offset acting to facilitate attentional disengagement or as a preparatory warning signal. Repeated measures Analysis of Variance (ANOVA) revealed that whereas the saccadic latencies of schizophrenics and normal controls do not differ for right visual field targets, the schizophrenics' latencies were prolonged to left visual field targets. This difference was most pronounced in the overlap condition, where normal controls produced faster saccades to the left visual field targets, whereas schizophrenics showed the opposite asymmetry. Because the overlap condition provides no early warning of the upcoming target, the lateralized finding suggests a deficit in the right hemisphere mechanisms responsible for sustained attention.

Naturally processed peptides from rheumatoid arthritis associated and non-associated HLA-DR alleles.

Naturally processed peptides from immunoaffinity-purified HLA-DRB1*0401, -DRB1*0404 (rheumatoid arthritis (RA)-associated), and -DRB1*0402 (non-RA-associated) molecules were analyzed by capillary liquid chromatography and mass spectrometry. The molecular weights observed for more than 60 eluted peptides from each HLA-DR protein ranged from 788 to 3535 atomic mass units, corresponding to peptides 7 to 32 amino acids in length. Sequencing of more than 60 of the abundant peptides revealed nested sets of peptides that were derived from only 12 different proteins. The majority of these proteins were membrane-associated (HLA class I, class II, and Ig molecules). Synthetic peptides, corresponding to endogenous peptide sequences, bound with high affinity (5 to 80 nM) to the HLA-DR molecules from which they were eluted. In addition, most were promiscuous binding peptides in that they also bound to other HLA-DR molecules. Truncations of eluted peptide sequences and alanine scanning mutational analysis of a Mycobacterium leprae peptide were used to identify the peptide residues involved in binding to DRB1*0404 and DRB1*0402 molecules. Furthermore, an invariant chain peptide was eluted from the DRB1*0402 molecules but not from the RA-associated molecules. The lack of invariant chain peptides from DRB1*0401 and DRB1*0404 molecules may contribute to the loading of autoantigen peptides into these molecules and to their association with disease.

HLA typing in women with breast implants.

Since the 1970s, anecdotal reports have described a relatively small number of women who received silicone gel breast implants and later developed either a recognized rheumatologic disease or unexplained symptoms suggestive of an autoimmune disorder. The study reported here examined whether there is any association between the symptoms seen in implant patients and HLA molecules. One-hundred and ninety-nine subjects were evaluated by HLA typing: symptomatic patients with implants (group I, n = 77), asymptomatic women with implants (group II, n = 37), healthy female volunteers without implants (group III, n = 54), and fibromyalgia patients without implants (group IV, n = 31). A statistically significant 68 percent of group I were positive for HLA-DR53, compared with 35 percent of group II and 52 percent of group III. The fibromyalgia patients were strikingly similar to group I women in terms of HLA-DR molecules, with 65 percent of group IV being positive for DR53. Group I also had a statistically significant increased frequency of HLA-DQ2. Asymptomatic women with implants (group II) had an increased frequency of DR1 and DQ1. In addition, 42 percent of symptomatic patients with implants formed autoantibodies to their own B cells; of these, 81 percent were DR53-positive. Although frequencies of capsular contracture and implant rupture were not significantly different in the two groups with implants, there were statistically significant associations in group I between contractures and ruptures and the presence of DR53 and B-cell autoantibodies. These data suggest that symptomatic patients with implants share important genetic characteristics (primarily HLA-DR53 positivity) that differentiate them from their asymptomatic counterparts. DR53 may be a marker of women who are predisposed by their HLA genotype to develop symptoms following exposure to silicone gel breast implants.

Negatively charged residues interacting with the p4 pocket confer binding specificity to DRB1*0401.

OBJECTIVE: To identify critical residues involved in the binding of a selective peptide to DRB1*0401. METHODS: The binding of peptides to native or site-directed mutant DR molecules was evaluated using enzyme-linked immunosorbent assay and flow cytometry. RESULTS: Amino acid substitutions at DR and peptide residues, which were predicted to contribute to interactions within the DR p4 pocket, had the greatest effects on the specificity of binding. CONCLUSION: Differences in the peptide-binding repertoires of DR molecules may contribute to associations with autoimmune diseases.

Smooth pursuit eye movement differences between familial and non-familial schizophrenia.

Disrupted smooth pursuit eye tracking characterizes a greater proportion of individuals with schizophrenia than in the normal population. The finding of a similar increased incidence of eye tracking abnormality in first degree relatives of schizophrenics implicates this disorder as a potential biological marker for schizophrenia. To test the assumption that the eye tracking dysfunction of schizophrenics is genetically related, left and right smooth pursuit gain and phase shift were compared between 20 schizophrenics with a family history of schizophrenia or schizophrenia-related disorders, 18 schizophrenics without a family history, as well as for 18 normal controls. Subjects tracked pendular targets on an LED light bar moving at frequencies of 0.2 and 0.7 Hz. Horizontal eye movements were recorded using DC-electro-oculography. Results indicate that schizophrenics with a positive family history had significantly reduced right pursuit gain compared with controls, while right gain for negative family history schizophrenics did not differ from either group. Schizophrenic subjects also were administered neuropsychological tests. Linear regression by groups analyses reveal that neuropsychological measures significantly predicted right gain to slower targets (0.2 Hz) for the positive family history schizophrenics, but not for negative family history schizophrenics.

Collagen-induced arthritis in the BB rat. Prevention of disease by treatment with CTLA-4-Ig.

Antigen-specific T cell activation requires two independent signalling events, one mediated through T cell receptor engagement by the antigen-presenting cell-expressed peptide/class II major histocompatibility complex, and the second through the cognate interactions of costimulatory molecules expressed on the T cell and antigen-presenting cell. There is evidence from in vitro and in vivo experimental systems suggesting that the CD28/B7 costimulatory pathway is crucial for induction of maximal T cell proliferation and T helper-B cell collaboration for IgG production. This pathway can be blocked by CTLA-4-Ig, a soluble form of CTLA-4 which binds with high avidity to the CD28 ligands, B7-1 and B7-2. Here, we show that CTLA-4-Ig treatment prevents clinical and histological manifestations of disease in a collagen-induced arthritis model of rheumatoid arthritis in the diabetes resistant BB/Wor rat, when therapy is initiated before immunization with bovine type II collagen (BIIC). Anti-BIIC antibody titers are reduced in CTLA-4-Ig-treated rats compared to diseased control animals. Histologically, joints from CTLA-4-Ig-treated animals show no histological abnormalities, in contrast to control antibody-treated animals, which show complete erosion of the articular cartilage and bone. Despite the efficacy of CTLA-4-Ig in preventing clinical and histological signs of arthritis and reducing antibody responses to BIIC, delayed type hypersensitivity responses to collagen 18 d or more after CTLA-4-Ig treatment ends are similar in CTLA-4-Ig-treated and untreated rats, suggesting that the prolonged disease suppression observed does not result from induction of T cell anergy.

Pocket 4 of the HLA-DR(alpha,beta 1*0401) molecule is a major determinant of T cells recognition of peptide.

To investigate the functional roles of individual HLA-DR residues in T cell recognition, transfectants expressing wild-type or mutant DR(alpha,beta 1*0401) molecules with single amino acid substitutions at 14 polymorphic positions of the DR beta 1*0401 chain or 19 positions of the DR alpha chain were used as antigen-presenting cells for five T cell clones specific for the influenza hemagglutinin peptide, HA307-19. Of the six polymorphic positions in the DR beta floor that were examined, mutations at only two positions eliminated T cell recognition: positions 13 (four clones) and 28 (one clone). In contrast, individual mutations at DR beta positions 70, 71, 78, and 86 on the alpha helix eliminated recognition by each of the clones, and mutations at positions 74 and 67 eliminated recognition by four and two clones, respectively. Most of the DR alpha mutations had minimal or no effect on most of the clones, although one clone was very sensitive to changes in the DR alpha chain, with loss of recognition in response to 10 mutants. Mutants that abrogated recognition by all of the clones were assessed for peptide binding, and only the beta 86 mutation drastically decreased peptide binding. Single amino acid substitutions at polymorphic positions in the central part of the DR beta alpha helix disrupted T cell recognition much more frequently than substitutions in the floor, suggesting that DR beta residues on the alpha helix make relatively greater contributions than those in the floor to the ability of the DR(alpha,beta 1*0401) molecule to present HA307-19. The data indicate that DR beta residues 13, 70, 71, 74, and 78, which are located in pocket 4 of the peptide binding site in the crystal structure of the DR1 molecule, exert a major and disproportionate influence on the outcome of T cell recognition, compared with other polymorphic residues.

Utilization of soluble fusion proteins for induction of T cell proliferation.

A peptide display library was evaluated as a means to identify peptide binding motifs for class II molecules. Peptides expressed as part of a soluble fusion protein with a maltose binding protein (malE) were produced by Escherichia coli. Constructs containing the high-affinity binding influenza hemagglutinin peptide 307W-319 (mal-HA) or the low-affinity binding tetanus toxoid peptide 830-843 (mal-TT) were used as controls. mal-HA, but not mal-TT, inhibited synthetic biotinylated-HA peptide from binding to purified DR4 Dw4 molecules in a dose-dependent manner. The fusion-peptide presentation system was also evaluated for its ability to induce antigen-specific T cell proliferation. DR4 Dw4+ B cells pulsed with mal-HA, but not mal-TT, induced dose-dependent proliferation of an HA-specific DR4 Dw4-restricted T cell line to the same extent as synthetic HA peptide. Using this type of peptide display library, it may be possible to determine the antigenic specificity of T cell clones isolated from patients with autoimmune diseases.