Characterization of a thyroiditis-inducing thyroglobulin-specific T-cell clone restricted by the H-2 molecule of a low responder mouse strain.

We established a thyroglobulin (Tg)-specific, thyroiditis-inducing T-cell clone, B12G, from B6C3F1 mice by the immunization of mouse Tg with lipopolysaccharide (LPS) from Klebsiella strain LEN (O3:K1). B12G was Thy-1.2+, CD3+, CD4+, CD18+, and CD8-, and could transfer thyroiditis to recipient mice after in vitro stimulation with mouse or bovine Tg. Histological examination showed severe thyroiditis with predominant infiltrations of polymorphonuclear cells; few mononuclear cells were observed. B12G proliferated in response to bovine, mouse, porcine, and rat Tg in the presence of irradiated spleen cells, but did not respond to chicken or human Tg. H-2b, a low-responder haplotype of experimental autoimmune thyroiditis, governed the response of the clone to Tg. B12G produced interleukin-4 (IL-4) and IL-6, but not IL-2 or interferon-gamma (IFN-gamma), on stimulation with mouse Tg. These findings were different from characteristics of previously reported Tg-specific T-cell clones from high-responder mice in terms of epitope specificity and cytokine production pattern, raising the possibility that the specificities and functions of T cells involved in the development of autoimmune thyroiditis in low-responder mice differ from those in high responders.     

Preparation of polyaniline by oxidation of aniline using H2O2 in the presence of an iron(II) catalyst

Oxidative polymerization of aniline using the H₂O₂-FeSO₄ system gave polyaniline under mild conditions. The prepared powdery emeraldine base, a form of polyaniline, is blue black and shows high solubility in organic solvents (e.g., ca. 200 mg/mL in N-methylpyrrolidone). The number-average molecular weight (M _n) of the polymer obtained was 1,3–1,7 · 10⁴ (via gel permeation chromatography vs. polystyrene) and M _w/M _n = 1,6–2,2. Poly(2-ethylaniline) and poly-(2-propylaniline) with high molecular weights were also synthesized by this procedure in high yield.     

G protein modulation of voltage-sensitive muscarinic receptor signalling in mouse pancreatic acinar cells

Submaximal stimulation of mouse pancreatic acinar cells by acetylcholine (ACh) generates periodic Ca2+ responses sensitive to the membrane potential. Monitoring the muscarinic Ca2+ responses using patch-clamp whole-cell current recordings, we examined the mechanism of guanine nucleotide-binding protein (G protein)-receptor interaction in terms of the membrane potential. The lowest ACh concentration able to elicit consistent repetitive spikes was 50 nM, in the presence of which hyperpolarization increased and depolarization decreased the spike frequency. The saturating concentration was 10 microM, this induced a sustained response insensitive to voltage. Internal guanosine 5'-tri- and diphosphates (GTP, GDP) depressed and potentiated the voltage sensitivity, respectively, but not for the response to a saturating ACh concentration (10 microM). Internal guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) abolished the voltage sensitivity. The results indicate that the ACh-induced Ca2+ response is sensitive to the membrane potential and that a close linkage exists between voltage sensitivity and the G protein association/dissociation cycle in the muscarinic receptor.     

A possible role of two hydrophobic amino acids in antigen recognition by synovial T cells in rheumatoid arthritis

Synovial T cells play a crucial role in the pathogenesis of rheumatoid arthritis (RA) synovitis. We have quantitatively analyzed the T cell receptor (TcR) variable (V) region gene repertoire of freshly isolated synovial fluid (SF) T cells, comparing it with that of peripheral blood (PB) T cells in RA. The TcR V gene repertoire of PB and SF T cells in RA and osteoarthritis was heterogeneous. In contrast, Vail in SF was expressed to a greater degree in three of five RA patients, and increased levels of Vp6, 1-3 were found in the SF of four of six RA, compared with paired PB. Of note, Vβ6, 1–3 was universally used in four RA patients with a disease duration of less than 10 years, irrespective of their HLA-DR types. This was in contrast to two other RA patients, suffering for more than 20 years, who showed different Vα and Vβ usages. β-chain sequence analysis in RA patients with a preference for Vβ6, 1–3 has shown that a few clones dominated in SF, whereas polyclonality was observed in PB. These findings suggest oligoclonal expansion of T cells in response to specific antigen(s) in the SF of these patients with RA of relatively short duration. Concomitant use of two hydrophobic amino acids, leucine and valine, in the Dβ region was noticeable among the predominant SF clones. These two amino acids might directly contact a peptide specific for the induction of synovitis in RA patients. TcR-directed therapy may, therefore, be useful for the treatment of early RA synovitis.     

Histochemical demonstration of endogenous estrogen in breast carcinomas: Biochemical and clinical correlation

Summary In a study of 277 patients with breast carcinomas, the PAP immunoperoxidase method for demonstrating endogenous estrogen was correlated with the sucrose density gradient (SDG) assay and with histologic and clinical features. The results from the PAP method and SDG assay agreed in 59 of 84 patients (82.1%) on whom both methods were performed. Histologically, the PAP method was positive in 7 of 7 patients with non-invasive carcinomas, in 164 of 233 patients (70.4%) with common invasive ductal carcinoma, and in 21 of 22 of those with special histological types of invasive carcinomas not including Paget's disease, medullary or apocrine carcinoma, where only 5 of 14 were positive. Clinically, 15 of 18 patients with positive endogenous estrogen showed a response to endocrine therapy as opposed to 1 of 9 patients with a negative endogenous estrogen. The mean survival was 31.2 and 15.6 months, respectively for patients with positive and negative endogenous estrogen. Remission for longer than 2 years was seen more often in patients with positive endogenous estrogen. These results suggest a clinical utility of the present PAP method which, therefore, deserves a further trial as an alternative to histochemical methods aiming at the estrogen receptors.This work was supported by Grants-in Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (No. 56480119).This paper was presented at the 72nd Annual Meeding of International Academy of Pathology (United States-Canadian Division), Atlanta, Georgia, March 1, 1983.     

Effects of non-MHC background genes on the induction of CD4+ T cells that prevent rejection of a highly immunogenic tumor, FBL-3

This study showed that non-MHC genes common to (DBA/2 H-2^d)and (DBA/1 H-2^q) gave rise to suppressor T (T_a) cells in thehybrid F₁ mice between C57BL/6 (B6) strain in the antl-FBL-3tumor responses. FBL-3, a Friend virus-induced tumor cell lineof B6 mouse origin, is highly immunogenic as shown by findingsthat syngenelc and hybrid F₁ mice with several other inbredstrains rejected up to 3 x 10⁷ tumor cells inoculated s.c. andgenerated potent CTL responses after mixed lymphocyte tumorcell culture. In contrast to these mice, (B6 x DBA/2) and (B6x DBA/1)F1 mice did not reject the tumor as the tumor dosesincreased. Progressive tumor growth in these F₁ mice was blockedby an I.p. Injection of cyclophosphamlde (250 mg/kg) on day10, but not on day 5, after tumor cell inoculation. Antl-CD4(GK1.5) mAb exerted similar therapeutic effects against tumorwhen given twice, between day 0 and 10, whereas the additionalinjection of antl-CD8 mAb enhanced the tumor growth in micethat otherwise rejected the tumor. Thus, In the response of(B6 x DBA/2)F, mice to FBL-3 tumor cells, CD4⁺ T₈ seemed todown-regulate the immunologically mediated regression of thetumor produced by CD8⁺ CTL. This was evidenced by limiting dilutionculture analyses, which showed that the frequency of an FBL-3-speclflcCTL precursor in the (B6 x DBA/2)F1 mice that rejected the tumorwith antl-CD4 mAb was 7- to 9-fold higher than that in micein which the tumor regressed spontaneously. That more than onegene was involved in suppressor T cell induction was shown bythe tumor growth pattern in (B6 x DBA/2)F₁ x B6 backcross andB6D2F2 mice.     

Significance of Levocarnitine Treatment in Dialysis Patients

Carnitine is a naturally occurring amino acid derivative that is involved in the transport of long-chain fatty acids to the mitochondrial matrix. There, these substrates undergo β-oxidation, producing energy. The major sources of carnitine are dietary intake, although carnitine is also endogenously synthesized in the liver and kidney. However, in patients on dialysis, serum carnitine levels progressively fall due to restricted dietary intake and deprivation of endogenous synthesis in the kidney. Furthermore, serum-free carnitine is removed by hemodialysis treatment because the molecular weight of carnitine is small (161 Da) and its protein binding rates are very low. Therefore, the dialysis procedure is a major cause of carnitine deficiency in patients undergoing hemodialysis. This deficiency may contribute to several clinical disorders in such patients. Symptoms of dialysis-related carnitine deficiency include erythropoiesis-stimulating agent-resistant anemia, myopathy, muscle weakness, and intradialytic muscle cramps and hypotension. However, levocarnitine administration might replenish the free carnitine and help to increase carnitine levels in muscle. This article reviews the previous research into levocarnitine therapy in patients on maintenance dialysis for the treatment of renal anemia, cardiac dysfunction, dyslipidemia, and muscle and dialytic symptoms, and it examines the efficacy of the therapeutic approach and related issues.