Genomic DNA released by dying cells induces the maturation of APCs.

Mature APCs play a key role in the induction of Ag-specific immunity. This work examines whether genomic DNA released by dying cells provides a stimulus for APC maturation. Double-stranded but not single-stranded genomic DNA triggered APC to up-regulate expression of MHC class I/II and various costimulatory molecules. Functionally, dsDNA enhanced APC function in vitro and improved primary cellular and humoral immune responses in vivo. These effects were dependent on the length and concentration of the dsDNA but were independent of nucleotide sequence. The maturation of APC induced by dsDNA may promote host survival by improving immune surveillance at sites of tissue injury/infection.

Treatment of Vogt-Koyanagi- Harada's disease during pregnancy.

BACKGROUND: Caution should be exercised in treating patients with autoimmune diseases during pregnancy. CASES: We successfully treated three cases of Vogt-Koyanagi-Harada's disease (VKH disease) during pregnancy. OBSERVATIONS: In the second trimester (14-27 weeks) of 1 patient, inflammation was mild and could be treated by topical corticosteroid. There is the possibility that her immune response had been modified by pregnancy. Systemic corticosteroid in a high dose was administered to the two cases in the second and third trimesters of pregnancy (28-41 weeks). The severity of inflammation in these 2 patients was similar to that in nonpregnant women. Inflammation subsided immediately without recurrence in all cases. No abnormality was found during the deliveries or in the babies. CONCLUSIONS: Treatment for VKH disease during pregnancy should be chosen according to the severity of inflammation, the stage of pregnancy, and the maternal and fetal conditions.

Graves' disease: a host defense mechanism gone awry.

In this report we summarize evidence to support a model for the development of Graves' disease. The model suggests that Graves' disease is initiated by an insult to the thyrocyte in an individual with a normal immune system. The insult, infectious or otherwise, causes double strand DNA or RNA to enter the cytoplasm of the cell. This causes abnormal expression of major histocompatibility (MHC) class I as a dominant feature, but also aberrant expression of MHC class II, as well as changes in genes or gene products needed for the thyrocyte to become an antigen presenting cell (APC). These include increased expression of proteasome processing proteins (LMP2), transporters of antigen peptides (TAP), invariant chain (Ii), HLA-DM, and the co-stimulatory molecule, B7, as well as STAT and NF-kappaB activation. A critical factor in these changes is the loss of normal negative regulation of MHC class I, class II, and thyrotropin receptor (TSHR) gene expression, which is necessary to maintain self-tolerance during the normal changes in gene expression involved in hormonally-increased growth and function of the cell. Self-tolerance to the TSHR is maintained in normals because there is a population of CD8- cells which normally suppresses a population of CD4+ cells that can interact with the TSHR if thyrocytes become APCs. This is a host self-defense mechanism that we hypothesize leads to autoimmune disease in persons, for example, with a specific viral infection, a genetic predisposition, or even, possibly, a TSHR polymorphism. The model is suggested to be important to explain the development of other autoimmune diseases including systemic lupus or diabetes.

Relationship among oxygenation, myoelectric activity, and lactic acid accumulation in vastus lateralis muscle during exercise with constant work rate.

The purpose of this study was to determine whether oxygenation in localized working muscle depended on the muscle activity and on the lactic acidosis level. Seven healthy male subjects underwent the five 6-min cycling exercises with work rates of 50 watts (25.0 +/- 5.0% VO2max), 100 watts (36.6 +/- 6.2% VO2max), 150 watts (50.6 +/- 7.7% VO2max), 200 watts (67.8 + 6.9% VO2max), and 250 watts (82.9 +/- 7.5% VO2max) while gas exchange parameters and blood lactate concentration (BL) were measured. We also measured oxygenated hemoglobin and myoglobin concentration (oxy-Hb/Mb) with continuous-wave near infrared spectroscopy (NIR) and surface myoelectric activity with surface electrodes (EMG). The NIR probe and electrodes were positioned on the vastus lateralis muscle of the right leg. The relative change in oxy-Hb/Mb was estimated by regarding oxy-Hb/Mb in the resting condition as 100% and that obtained during thigh occlusion as 0%. The mean values of oxy-Hb/Mb and integrated EMG (iEMG) were determined from 5'30" to 6'00" at each work rate. The percentage of oxy-Hb/Mb was sustained at the first two work rates corresponding to 25.0 +/- 5.0 and 36.6 +/- 6.2% VO2max and decreased slightly at 150 watts corresponding to 50.6 +/- 7.7% VO2max, which was followed by a linear decrease at 200 and 250 watts corresponding to 67.8 +/- 6.9 and 82.9 +/- 7.5% VO2max. The iEMG, however, was increased slowly at 25.0 +/- 5.0 to 50.6 +/- 7.7% VO2max, and a rapid increment of the iEMG occurred at 67.8 +/- 6.9 and 82.9 +/- 7.5% VO2max. BL was sustained at 25.0 +/- 5.0 to 50.6 +/- 7.7% VO2max and increased linearly at 67.8 +/- 6.9 and 82.9 +/- 7.5% VO2max. There was a significant negative correlation for each subject between the percentage of oxy-Hb/Mb and iEMG (r = -0.947 to -0.993), between the percentage of oxy-Hb/Mb and BL (r = -0.890 to -0.982), and between the percentage of oxy-Hb/Mb and VO2 (r = -0.929 to -0.994) These results indicated that oxygenated hemoglobin/myoglobin concentration measured with NIR reflected the muscle activity and the lactic acidosis.

Expression of transforming growth factor-beta1 and transforming growth factor-beta Type-II receptor mRNA in papillary thyroid carcinoma.

Transforming growth factor-beta1 (TGF-beta1) is a potent inhibitor of epithelial cell proliferation. Signal transduction by TGF-beta1 involves direct binding to the TGF-beta Type-II receptor and then the formation of a heterodimeric complex of TGF-beta Type-I and Type-II receptor. To explore the role of TGF-beta1 in thyroid carcinoma, we examined the expression of TGF-beta1 and TGF-beta Type-II receptor mRNA by northern blotting analysis in both 14 papillary thyroid carcinomas and surrounding normal thyroid tissues. Relative mRNA level was determined by scanning densitometry of the autoradiogram and corrected for loading differences using a human beta-actin cDNA probe. The relative mRNA levels of TGF-beta1 in 12 out of 14 papillary thyroid carcinomas were higher than those in surrounding normal thyroid tissues. In contrast, the relative mRNA levels of TGF-beta Type-II receptor were reduced to 60.1+/-18.3% of those of normal thyroid tissues in 10 papillary thyroid carcinomas. There were no clear relationships between the relative mRNA levels for TGF-beta1 and TGF-beta Type-II receptor and the histological characteristics of papillary thyroid carcinomas. The relative mRNA levels for TGF-beta1 and TGF-beta Type-II receptor did not show significant differences in thyroid carcinomas with or without lymph node metastases. There was a negative correlation between the TGF-beta Type-II receptor mRNA level and tumor size, while no significant correlation was observed between the TGF-beta1 mRNA level and tumor size. In conclusion, most papillary thyroid carcinomas overexpress TGF-beta1 mRNA but exhibit a reduction in TGF-beta Type-II receptor mRNA. The reduction of TGF-beta Type-II receptor mRNA may play a role in the pathogenesis of papillary thyroid carcinoma.

Hyponatremia in a patient with chronic inflammatory disease.

A 66-year-old man was admitted with destructive arthropathy, and calcium pyrophosphate dihydrate was demonstrated in the synovial fluid specimen. He was found to have a hyponatremia. The serum sodium concentration was 121 mmol/l, plasma arginine vasopressin (AVP) 6.6 pmol/l, and serum interleukin (IL)-6 96 pg/l. The clinical findings suggest the diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH). However, destructive arthropathy with increased values of C-reactive protein and IL-6 is the only background of SIADH in this patient. We suggest the possibility that IL-6 produced at inflammatory lesions may have stimulated an excessive release of AVP resulting in the hyponatremia and hypochloremia of SIADH.

Interferon-alpha-induced thyroid dysfunction in patients with chronic active hepatitis C: a transient, reversible and self-limited dysfunction.

To survey the prognoses of interferon-alpha (IFNalpha)-induced thyroid dysfunction, a total of 100 patients (49 males and 51 females) with biopsy-proven chronic active hepatitis C were studied. Either during or after IFNalpha therapy, 29 patients (33.7%) revealed suppression/elevation of thyroid stimulating hormone (TSH) or both, transient thyrotoxicosis (TSH less than 0.1 microU/ml) or transient hypothyroidism (TSH 5.0-190.95 microU/ml). However, the thyroid function normalized without supplementation of the thyroid hormone in the follow-up period. In the same period, one of the 14 control patients (7.1%) developed thyroid dysfunction. Thyroid abnormalities developed significantly more in patients with IFNalpha therapy than in those without IFNalpha therapy. The findings suggest that the occult autoimmune disorder becomes overt with IFNalpha treatment in patients with pre-existent autoimmune thyroid disease. IFNalpha-induced thyroid dysfunction is transient, reversible and self-limited. It is not necessary to discontinue IFNalpha therapy when thyroid dysfunction develops.

Does prolonged exercise alter diet-induced thermogenesis?

Diet-induced thermogenesis (DIT) is mainly an insulin-mediated response and the result of fat and glycogen synthesis. We investigated DIT at rest and after exercise to clarify the mechanism of exercise-induced changes in DIT in 6 healthy men (mean age 36 +/- 16 years). Subjects exercised for 1 h at 58% of maximal O2 consumption on a bicycle ergometer and then rested for 8 h sitting in a comfortable chair (exercise experiment). On a different day, subjects rested for 8 h without preceding exercising (non-exercise experiment). At 12.30 h, the subjects were given their second meal. DIT to individual meal did not differ significantly between the exercise and non-exercise days. Increased insulin sensitivity and increased free fatty acid oxidation by exercise may facilitate the conversion of glucose to glycogen in muscle. On the other hand, insulin secretion expressed as the ratio of plasma levels of insulin to glucose after the meal was significantly decreased in the exercise experiment (p < 0.05). Study of heart rate variability showed that sympathetic tone, a primary hormonal determinant of glucose metabolism during exercise, was increased and parasympathetic tone was decreased during the recovery period in the exercise experiment (p < 0.05). These findings suggest that changes in DIT are affected by many factors and may be related to the balance between these counteracting factors.

Diffusion-weighted imaging of the human optic nerve: a new approach to evaluate optic neuritis in multiple sclerosis.

The apparent diffusion coefficient (ADC) in the optic nerve was measured from diffusion-weighted magnetic resonance imaging using an intravoxel incoherent motion (IVIM) sequence. The subjects were seven normal volunteers and eight patients with multiple sclerosis (MS) with a total of four optic nerves with acute neuritis and nine nerves with chronic neuritis. The mean ADC (4.18 +/- 1.13 x 10(-3) mm2/s, n = 9) in the optic nerves with chronic neuritis was significantly higher than that in normal volunteers (1.56 +/- 0.675 x 10(-3) mm2/s, n = 14) and that in the nerves with acute neuritis (0.94 +/- 0.43 x 10(-3) mm2/s n = 4) (P < 0.001). The ADC is useful in assessing MS foci in the optic nerves.

Serum androgen levels in hyperthyroid women.

Thyroid hormone is known to affect androgen metabolism, however, there are few studies in which alterations of androgen metabolism are simultaneously examined in patients with clinical thyroid disorders. In this study, we investigated the alterations of thyroid hormone and androgens before and during treatment in patients with hyperthyroidism. Fifteen female patients with hyperthyroidism due to Graves' disease were studied. From these patients, blood samples were obtained before treatment and at 1 month (M), 2M, 3M, 4M and 6M after beginning of treatment. Concentrations of free T4(FT4), free T3(FT3), testosterone (T), androstenedione (delta 4A), dihydrotestosterone (DHT), 5 alpha-androstane-3 alpha, 17 beta-diol(3 alpha-diol) and androsterone (AD) and sex hormone binding globulin (SHBG) were measured by radioimmunoassays (RIAs) or immunoradiometric assay (IRMA). As normal controls, ten healthy women were also studied. Before treatment concentrations of DHT (mean +/- SD: 3.35 +/- 0.78 nmol/L), 3 alpha-diol (0.78 +/- 0.11 nmol/L), AD (6.73 +/- 0.64 nmol/L) and SHBG (184.9 +/- 68.1 nmol/L) were significantly elevated compared with those of normal controls. T and delta 4A levels were not significantly different from normal values. DHT/T ratio indicating 5 alpha-reductase activity was 4.62 +/- 2.55 and significantly higher than that in normal controls. At 2 months after beginning of treatment with anti-thyroid drugs, thyroid function (FT4 and FT3) became normal and at 3 months after beginning of treatment, DHT, 3 alpha-diol, AD and DHT/T ratio decreased to normal range. SHBG level was gradually decreased, however still higher than that of the normal control group at 6 months after beginning of treatment. There was a time lag in recovery between serum androgen levels and SHBG level.

Decreased contraction economy in mouse EDL muscle injured by eccentric contractions.

The objective of this study was to find out whether basal and/or active energy metabolism are altered in isolated mouse extensor digitorum longus muscle injured by eccentric (Ecc) contractions. Measurements of basal O2 consumption and isometric tetanus O2 recovery cost were made at 25 degrees C on muscles that had done either 10 Ecc, 10 isometric (Iso), or no contractions (No). In parallel experiments, rates of lactate and pyruvate production were measured to estimate the anaerobic contribution. Basal O2 consumption was unaffected by the type of protocol performed (P = 0.07). However, the tetanus O2 cost per force-time integral was elevated by 30-36% for the Ecc protocol muscles over that for the Iso and No protocol muscles. When including the increased lactate production by the Ecc protocol muscles, the total energetic cost per force-time integral was 53% higher than that for the Iso protocol muscles [2.35 +/- 0.17 vs. 1.54 +/- 0.18 mumol O2/(N.m.s)]. The decreased economy was attributed to two factors. First, in skinned fibers isolated from the injured muscles, the ratio of maximal actomyosin adenosinetriphosphatase activity to force production was up by 37.5%, suggesting uncoupling of ATP hydrolysis from force production. Second, increased reliance on anaerobic metabolism along with the fluorescent microscopic study of mitochondrial membrane potential and histochemical study of ATP synthase suggested an uncoupling of oxidative phosphorylation in the injured muscles.

Insufficient expression of Fas antigen on helper T cells in Behçet's disease.

AIMS: To investigate the lack of equilibrium in the regulatory mechanism of the immune system in Behçet's disease (BD), the expression of Fas antigen, an apoptosis related antigen, on peripheral blood lymphocytes from BD patients was analysed. METHODS: Twenty one BD patients were the subjects in this study. Ten healthy adults were examined as controls. Cell surface antigens of lymphocytes were analysed with flow cytometry. RESULTS: There was a significant (p < 0.01) difference in the proportion of CD4 positive cells with CD25 between BD patients with active uveoretinitis (27.6% (SD 8.4%)) and the controls (14.7% (2.3%)), but no significant difference in the proportion of CD4 or CD45RO positive cells with Fas. On the other hand, the proportion of CD8 positive cells with Fas was significantly (p < 0.01) higher in BD patients with active uveoretinitis (45.6% (11.6%)) than in those with inactive uveoretinitis (23.8% (8.1%)) or in the controls (24.4% (2.5%)). The proportion of CD19 positive cells with Fas was also significantly (p < 0.01) higher in BD patients with active uveoretinitis (13.0% (5.0%)) than in the controls (5.1% (2.1%)). CONCLUSION: The insufficient expression of Fas on activated CD4 positive T cells and its high expression on CD8 positive T cells seem to play an important role in the chronic inflammation in BD.

Attenuation of Ca(2+)-induced increase in oxidative metabolism by cooling and calmodulin antagonist in mammalian brain neurons: a flow-cytometric study.

Effects of cooling and calmodulin antagonist on ionomycin-induced increase in oxidative metabolism (or formation of reactive oxygen species) of rat cerebellar neurons was examined using a flow cytometer and 2',7'-dichlorofluorescin diacetate, a fluorescent dye for intracellular hydrogen peroxide. Cooling neurons to temperatures below 16 degrees C greatly attenuated ionomycin-induced augmentation of oxidative metabolism without affecting the Ca2+ influx produced by ionomycin. Rewarming neurons to 36 degrees C in presence of ionomycin increased the oxidative metabolism, indicating a temperature-sensitive metabolic process. Substitution of Ca2+ with Ba2+ or Sr2+ completely abolished an ionomycin-induced increase in the oxidative metabolism. Pretreatment with W-7, a calmodulin antagonist, at concentrations of 10 microM or higher (up to 100 microM) produced a dose-dependent attenuation of ionomycin-induced increase in oxidative metabolism. Results suggest that calmodulin is involved in the ionomycin-induced increase in oxidative metabolism of dissociated cerebellar neurons.

Changes in myosin heavy chain isoform expression of overloaded rat skeletal muscles.

1. The effect of functional overload produced by tenotomy of synergistic gastrocnemius muscle on the expression of myosin heavy chain (MHC) isoforms in the plantaris and soleus muscles of the rat was studied using gradient sodium dodecyl sulfate-acrylamide gel electrophoresis. 2. Five weeks tenotomy, the plantaris and soleus muscle weights induced by tenotomy of the gastrocnemius muscle were 44.3% (P < 0.005) and 37.4% (P < 0.005), respectively, heavier than the contralateral control muscles. 3. Although four types of MHC isoforms were observed in both control and experimental plantaris, the percentage of MHC isoforms in the control and experimental muscles differed; the hypertrophied plantaris muscle contained more HCI (P < 0.05), HCIIa and HCIId (P < 0.05) and less HCIIb (P < 0.05) than the control muscle. 4. The control soleus muscle contained two MHC isoforms, HCI and HCIIa. However, there was only a single HCI isoform in the hypertrophied soleus muscle. 5. These results indicate that overloading a skeletal muscle by removing its synergists produces not only the muscle hypertrophy but also the changes in the expression of MHC isoforms.

Myosin light chain patterns in histochemically typed single fibers of the rat skeletal muscle.

1. This study was conducted to investigate the relationship between histochemical fiber types and myosin light chain patterns in rat single muscle fibers. 2. The hybrid of fast and slow light chains was observed in type I and II fibers of the soleus and type II fibers of the red portion of lateral head of the gastrocnemius muscles. 3. We also observed 7 types of light chain composition. Of the 7 types, 5 types were explainable by assuming the coexistence of isomyosins with either fast or slow light chains. However, the other 2 types could not be accounted for without hypothesizing the presence of isomyosins with promiscuous light chain distribution.

Triphenyltin-induced increase in the intracellular Ca2+ of dissociated mammalian CNS neuron: its independence from voltage-dependent Ca2+ channels.

To test the possibility that triphenyltin (TPT) increases the intracellular Ca2+ ([Ca2+]i) in neurons as found previously in thymocytes, the effect of TPT on [Ca2+]i was examined in rat cerebellar neurons by a flow-cytometer with fluorescent dyes. TPT at concentrations ranging from 3 x 10(-7) M to 1 x 10(-5) M dose-dependently increased the [Ca2+]i. The TPT-induced increase in [Ca2+]i was not attenuated by a Ca2+ channel blocker, suggesting that it was not dependent on voltage-dependent Ca2+ channels. As the concentration of external Ca2+ ([Ca2+]e) increased, TPT produced a more profound increase in the [Ca2+]i. However, the increase in the [Ca2+]i by TPT was observed even in nominally [Ca2+]e-free solution. These results suggest two possibilities. First, TPT may promote Ca(2+)-influx to the neuron. Secondly, TPT may affect the intracellular Ca-store sites. This study is relevant to the neurotoxicity of organotins because it has become progressively clear that sustained increases in the [Ca2+]i can activate various Ca(2+)-dependent degradative processes.

Myosin heavy chain isoform transition in ageing fast and slow muscles of the rat.

Using gradient sodium dodecyl sulphate-polyacrylamide gel electrophoresis, myosin heavy chain (MHC) isoforms were studied in the extensor digitorum longus (EDL) and the soleus muscles of male Wistar rats at different ages (5, 10, 20 weeks, 1 and 2 years). In the EDL muscle, four types of MHC isoforms were observed in all age groups. There was an increase in the percentage of HCIId and a concomitant decrease in the percentage of HCIIb with increasing age. No significant difference was observed in the percentages of HCI and HCIIa isoforms in all the age groups. In contrast, the soleus muscle contained two MHC isoforms, HCI and HCIIa. There was an increase in the percentage of HCI and a concomitant decrease in the percentage of HCIIa with increasing age. These results suggest that age-related changes in the MHC isoforms in both the fast-twitch EDL and the slow-twitch soleus muscles are one factor underlying the age-related decrease in the speed of muscle contraction.