Tolerance in TCR/Cognate Antigen Double-Transgenic Mice Mediated by Incomplete Thymic Deletion and Peripheral Receptor Downregulation

Influenza nucleoprotein (NP)-specific T-cell receptor transgenic mice (F5) were crossed with transgenic mice expressing the cognate antigenic protein under the control of the H- 2K^b promoter. Double-transgenic mice show negative selection of thymocytes at the CD4⁺8⁺TCR¹⁰ to CD4⁺8⁺TCR^hi transition stage. A few CD8 T cells, however, escape clonal deletion, and in the peripheral lymphoid organs of these mice, they exhibit low levels of the transgenic receptor and upregulated levels of the CD44 memory marker. Such cells do not proliferate upon exposure to antigen stimulation in vivo or ex vivo, however, they can develop low but detectable levels of antigen-specific cytotoxic function after stimulation in vitro in the presence of IL-2.     

Inefficient clustering of tyrosine-phosphorylated proteins at the immunological synapse in response to an antagonist peptide

Interactions of T cells with MHC plus peptide in the peripheral lymphoid system are important for their survival. In this study we investigated further the molecular consequences of such interactions using F5 TCR transgenic mice and peptides previously shown to induce either negative or positive selection in the thymus. Following TCR ligation with the negatively selecting agonist peptide, mature CD8(+) cells proliferated and up-regulated the activation marker CD69. Interestingly, ligation of this TCR with MHC molecules loaded with high concentrations of the positively selecting peptide also resulted in the aforementioned changes, but with slower kinetics. Analysis of the biochemical changes that occur following stimulation with these peptides showed that phosphorylation of key signaling molecules, such as ZAP-70, CD3zeta, Vav, SLP-76, LAT, and ERK-1 and 2, could be detected after exposure to agonist but not antagonist peptide. Confocal microscopy, however, revealed infrequent phosphorylation 'patches' at the site of contact between T cells and APC presenting the antagonist peptide. Our data suggest that peptides capable of inducing positive selection in the thymus can be recognized by mature T cells and cause proliferation, up-regulation of CD69 and accumulation of phosphorylated proteins at the immunological synapse with low efficiency; however no phosphorylation of signaling molecules can be detected using conventional biochemical assays.     

Gabapentin in the acute treatment of refractory bipolar disorder

Background: Gabapentin, a new anti-epileptic agent, has been anecdotally reported to be effective in the treatment of mania. We systematically assessed the response rate in bipolar patients being treated adjunctively with gabapentin for manic symptoms, depressive symptoms, or rapid cycling not responsive to standard treatments.
Method: Twenty-eight bipolar patients experiencing manic (n=18), depressive (n=5), or rapid-cycling (n=5) symptoms inadequately responsive to at least one mood stabilizer were treated in an open fashion with adjunctive gabapentin. Illness response was assessed using the Clinical Global Impression Scale modified for bipolar disorder (CGI-BP). A 'positive response' was operationalized as a CGI response of much or very much improved.
Results: Fourteen of the 18 (78%) treated for hypomania or mania had a positive response to a dosage range of 600–3600 mg/day. Patients with hypomania responded fastest, with a positive response achieved in 12.7±7.2 days. Patients with classic mania had a mean time to positive response of 25±12 days, and in patients with mixed mania it was 31.8±20.9 days. All of the five patients treated for depression had a positive response within 21±13.9 days. Only one of five patients with rapid cycling had a positive response. Gabapentin was well tolerated by all patients, with the most common side-effect being sedation.
Conclusions: Gabapentin appears to have acute anti-manic and anti-depressant properties as an adjunctive agent for refractory bipolar illness. Prospective double-blind studies are needed to further delineate its acute efficacy when used as monotherapy and its prophylactic efficacy as monotherapy or in conjuction with other mood stabilizers.     

Combined Clozapine and Electroconvulsive Therapy

We reviewed consecutive patients (n = 12) at McLean Hospital from 1990 through 1991 treated with the combination of the atypical antipsychotic agent clozapine and electroconvulsive therapy (ECT). There were no adverse effects. Three patients had a marked clinical improvement, one a moderate response, four a minimal response, two minimal to no response, and two no response. Using daily doses of up to 550 mg clozapine, this combination appears to be safe, and may be useful in some patients with treatment-refractory psychosis.     

Two-year syndromal and functional recovery in 219 cases of first-episode major affective disorder with psychotic features

OBJECTIVE: Psychotic affective disorders are the most prevalent idiopathic psychoses, but their outcome from onset has rarely been studied. In this study, the authors determined the rate and latency of syndromal recovery and rates of functional recovery after first lifetime hospitalization in patients with first-episode psychotic affective disorders. METHOD: From first lifetime hospitalization in 1989-1996, 219 patients with a DSM-IV psychotic affective illness were assessed at intervals over 24 months. Time to syndromal recovery (no longer meeting DSM-IV episode criteria) was assessed by survival analysis, and functional recovery (regaining baseline vocational and residential status) was rated. Factors associated with recovery were identified by bivariate and multivariate methods. RESULTS: By 3, 6, 12, and 24 months after first hospitalization, syndromal recovery was attained by 65.1%, 83.7%, 91.1%, and 97.5%, respectively, of subjects. Time to syndromal recovery (6.1 weeks to 50% of subjects recovered) was shorter for patients who had bipolar disorder, were married, were age 30 or older at onset, lacked comorbidity, required relatively brief hospitalization, and received fewer medicines. Functional recovery by 6 (30.4%) and 24 months (37. 6% of patients) was 2.6-2.7 times less likely than syndromal recovery; 63.1% of those recovering syndromally did not recover functionally by 2 years. Functional recovery was associated with older age at onset and shorter hospitalization. Annual recovery rates remained stable as mean hospital length of stay decreased 3. 6-fold over the 8-year study period. CONCLUSIONS: Syndromal recovery was attained by most psychotic affective disorder patients soon after hospitalization, but only one-third recovered functionally by 24 months. The findings suggest that these very common psychotic illnesses can carry a grave functional prognosis from the initial episode and first hospitalization.     

Comparison of the internal state scale to clinician-administered scales in asthma patients receiving corticosteroid therapy

Mood symptoms are reported frequently in asthma patients, particularly during corticosteroid therapy. This investigation compared the Internal State Scale (ISS), a self-report measure of symptoms of mania and depression, to the Hamilton Rating Scale for Depression (HRSD), Young Mania Rating Scale (YMRS), and Brief Psychiatric Rating Scale (BPRS) in a group of asthma patients (n=60 at baseline) before, during, and after a 1-2 week burst of prednisone. The depression and well being subscales of the ISS correlated well with HDRS scores. The perceived conflict subscale correlated with the BPRS scores. However, none of the ISS subscales correlated consistently and specifically with the YMRS in this population. Possible explanations for differences observed in bipolar versus asthma patients given the ISS are discussed. These data suggest the ISS may be a useful tool for depression symptoms and overall psychopathology in asthma patients and in patients receiving corticosteroid therapy. However, its ability may be attenuated outside of the population for which it was designed.