Phylogenetic relationship of the genus Oncorhynchus species inferred from nuclear and mitochondrial markers

The phylogenetic relationship among the salmonid fishes of the genus Oncorhynchus has been analyzed using various kinds of markers for a long time. However, there are three major disagreements among those studies; (1) the authenticity of the Pacific salmon group as a monophyletic cluster, (2) the phylogenetic relationship among three Pacific salmons (pink salmon, sockeye salmon, and chum salmon), and (3) the phylogenetic position of masu salmon. We used allozyme electrophoresis to clarify the phylogenetic relationship between the Pacific salmon group and the Pacific trout group. Furthermore, we reanalysed published mitochondrial DNA D-loop sequences (Shedlock et al., 1992). Allozymic data and mtDNA data indicated the following consistent results; (1) all Pacific salmons formed a monophyletic cluster, (2) chum salmon and pink salmon were clustered within those Pacific salmons, (3) masu salmon formed a cluster with other Pacific salmons and diverged first in this group.

Familial hypocholinesterasemia found in a family and a new confirmed mutation

A 45-year-old man was hospitalized because of acute hepatitis. His serum cholinesterase (ChE) was below 10 IU/l (normal range: 105-240 IU/l) during the disease course and after his recovery. The patient was suspected of having familial hypocholinesterasemia. His family members were healthy except that his father had hypertension and gall stones. Analysis of ChE gene in the propositus and his family revealed three point mutations at nucleotides 298 (CCA to TCA), 1,410 (CGT to CGG) and 1,615 (GCA to ACA). The first mutation caused an amino acid change at codon 100 from proline to serine, which was a new mutation not previously reported, but the second one was a silent mutation. The third mutation resulted in an amino acid alteration from alanine to threonine at codon 539 in exon 4 of the ChE gene. The mode of transmission of these mutations is described.

FK960 N-(4-acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate ameliorates the memory deficits in rats through a novel mechanism of action

With passive avoidance (PA), Morris water maze (WM) and eight-arm radial maze tasks, we evaluated the memory-enhancing action of FK960 [N-(4-acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate], a compound which we have found through rational drug screening based on our hypothesis that penile erection is a valid predictor of central cholinergic activation. Memory performance in the tasks was impaired in aged (24- to 26-months-old) rats as well as in rats with nucleus basalis magnocellularis lesions. Scopolamine (1 mg/kg i.p.) treatment induced memory impairment in PA and WM; treatment with cysteamine (200 mg/kg s.c.) induced memory impairment in PA but not in WM, whereas fimbria fornix lesioning affected the rats in the opposite manner. FK960 (0.1-10 mg/kg i.p.) ameliorated all the memory impairments except those induced by cysteamine or fimbria fornix lesion, and the dose-response curves were bell shaped with maximal response at 1 to 3.2 mg/kg. The effects of FK960 on the scopolamine-induced memory impairment in the PA and/or WM were abolished by cysteamine (200 mg/kg s.c.), dl-p-chlorophenylalanine methyl ester hydrochloride (150 mg/kg i.p. for 3 days) or raphe lesioning, but not by neonatal 6-hydroxydopamine (35 micrograms/head) treatment. Neurochemical analysis revealed that cysteamine and raphe lesions reduced brain somatostatin and serotonin contents, respectively. The treatment with FK960 (0.32-320 mg/kg p.o.) dose-dependently increased both serotonin and 5-hydroxyindoleacetic acid levels in the brain areas examined and significantly increased hippocampal somatostatin contents at the smaller doses. From these results, we conclude that FK960 ameliorates cognitive dysfunction through an activation of the somatostatinergic-serotonergic link.

Lack of B7-1/BB1 and B7-2/B70 expression on thyrocytes of patients with Graves' disease. Delivery of costimulatory signals from bystander professional antigen-presenting cells

We have previously demonstrated that thyrocytes from patients with Graves' disease induce autologous peripheral blood T cell proliferation in response to soluble antigens, and a synergistic augmentation of T cell response by adding suboptimal numbers of monocytes. In the present study, we examined the role of costimulatory molecules, expressed on the surface of thyrocytes and intrathyroidal mononuclear cells, in antigen-specific T cell proliferation. Intercellular associated molecule (ICAM)-1 and lymphocyte function associated antigen-3 were constitutively expressed on the surface of both normal and Graves' thyrocytes. However, ICAM-2, vascular cell adhesion molecule-1, B7-1, and B7-2 were not detected and induced by cytokines. B7-1, was expressed on intrathyroidal monocytes only, while B7-2 was present on intrathyroidal lymphocytes, peripheral blood monocytes, and intrathyroidal monocytes. Furthermore, the density of B7-2 was higher on intrathyroidal monocytes than on peripheral blood monocytes. The intensity of CD28 expression on intrathyroidal CD8bright+ cells was less than that on peripheral blood CD8bright+ cells. The antigen-specific T cell response induced by thyrocytes was blocked completely by anti-human leukocyte antigen-DR monoclonal antibody (mAb) and partially by anti-ICAM-1 mAb and anti-lymphocyte function associated antigen-3 mAb. Furthermore, the synergistic augmentation of T cell response, induced by the addition of suboptimal number of monocytes, was suppressed completely by combining anti-B7-1 mAb and anti-B7-2 mAb, to a level equivalent to that observed when thyrocytes were used alone as antigen-presenting cells. Our results suggest that T cell proliferation was induced by cooperation of thyrocytes and infiltrating professional antigen-presenting cells.

Effects of gemfibrozil administration on very low density lipoprotein receptor mRNA levels in rabbits

To elucidate the regulation of very low density lipoprotein (VLDL) receptor gene expression, we administered to rabbits for 14 days gemfibrozil, a fabric acid derivative and a lipid lowering drug that is also included among peroxisome proliferators. VLDL receptor mRNA levels were examined by Northern blot analysis. The VLDL receptor mRNA levels in retroperitoneal adipose tissue and in gastrocnemius muscle were increased 6.9-fold and 3.7-fold, respectively, with gemfibrozil treatment, but no marked changes were observed in the heart, the organ in which VLDL receptor is most highly expressed. In the liver, VLDL receptor mRNA was not detected either before or after gemfibrozil administration. Lipoprotein lipase (LPL) and long-chain acyl coenzyme A synthetase (ACS) mRNA levels were also increased in parallel in adipose tissue. The enhanced expression of VLDL receptor mRNA may contribute to the increase of triglyceride-rich lipoprotein catabolism in peripheral tissues such as adipose tissue and muscles.

The glycine/NMDA receptor antagonist HA-966 impairs visual recognition memory in rhesus monkeys

Recent studies have shown that strychnine-insensitive glycine binding sites positively modulate the N-methyl-D-asparate (NMDA) subclass of glutamate receptors, which are important in neural pathways involved in cognitive function. We examined the effect of (+/-)-3-amino-1-hydroxy-2-pyrrolidone (HA-966), a highly specific antagonist of this glycine modulatory site on the NMDA receptor, on visual recognition memory in four rhesus monkeys performing a computer-automated version of delayed nonmatching-to-sample (DNMS) with a list length of 20 trial-unique graphic symbols. In addition, the effect of HA-966 was compared with that of (+)-5-methyl-10, 11-dihydro-5H-dibenzo[a,d]cyclohepten-5, 10-imine (dizocilpine; MK-801), a noncompetitive NMDA channel blocker. Administration of HA-966 (0.1-10 mg/kg, i.m.) 30 min before testing impaired DNMS performance dose-dependently, starting at doses of 3.2 mg/kg; the memory deficity following the highest dose (10 mg/kg) was associated with prolonged response latencies. Similar impairments in recognition memory were observed following treatment with MK-801, though at much lower doses (3.2-32 micrograms/kg) than those at which HA-966 was effective. Administration of low doses of HA-966 (1 mg/kg) and MK-801 (10 micrograms/kg), each of which had no significant effect on performance when given alone, also failed to impair performance when given concurrently. Combined administration of both drugs, each at amnesia-producing doses (3.2 mg/kg of HA-966 plus 32 micrograms/kg of MK-801), markedly impaired performance in an additive, not a synergistic, manner. From these results, we propose that the recognition memory impairment observed in our monkeys following HA-966 administration is via an action on the glycine modulatory site of the NMDA receptor complex.

Brain somatostatin depletion by cysteamine attenuates the penile erection induced by serotonergic and dopaminergic, but not by cholinergic, activation in rats

To clarify the role of brain somatostatin in the expression of penile erection, the effects of cysteamine, a somatostatin depletor, on the penile erection induced by serotonergic, cholinergic and dopaminergic stimulants were investigated in rats. Fenfluramine (0.1-10 mg/kg, i.p.), pilocarpine (0.032-3.2 mg/kg, i.p.) and apomorphine (0.01-1 mg/kg, i.p.) induced penile erection in rats, with bell-shaped dose-response curves. Pretreatment with cysteamine (200 mg/kg, s.c.) significantly attenuated the penile erection induced by fenfluramine and apomorphine, but scarcely affected that induced by pilocarpine. Neurochemical measures revealed that cysteamine pretreatment significantly reduced the somatostatin content in all brain regions examined. These results provide the first pharmacological evidence that the brain somatostatin may play an important role in drug-induced penile erection.

D-cycloserine, a partial agonist at the glycine site coupled to N-methyl-D-aspartate receptors, improves visual recognition memory in rhesus monkeys

Strychnine-insensitive glycine binding sites have recently been shown to positively modulate N-methyl-D-aspartate (NMDA) receptors. In the present study, the effects on recognition memory of D-cycloserine, a partial agonist at the glycine modulatory site on the NMDA receptor, were evaluated in rhesus monkeys performing a computer-automated version of delayed nonmatching-to-sample (DNMS) with a list length of 20 trail-unique graphic symbols. Single administration of D-cycloserine (100-1000 micrograms/kg i.m.) facilitated DNMS performance significantly with an inverted U-shaped dose-response curve when given 30 min before testing. To assess further the possible neural mechanisms, D-cycloserine was evaluated for its effects on the memory impairments after blockade of the glycine sites by HA-966, N-methyl-D-aspartate receptors by MK-801, or cholinergic receptors by scopolamine. D-Cycloserine completely reversed the visual recognition memory deficits produced by HA-966 (3.2 mg/kg i.m.). D-Cycloserine also dose-dependently and significantly restored the memory deficits produced by MK-801 (32 micrograms/kg i.m.). In addition, D-cycloserine produced a partial, though significant, improvement on the recognition memory deficits after cholinergic blockade with scopolamine (10 micrograms/kg i.m.). From these results, we propose that D-cycloserine has a cognition-enhancing property in non-human primates and that it may have a potential value in treating dementias. Furthermore, the present results provide new evidence for the important role for the glycine sites in the regulation of recognition memory.

Inhibition of Fas antigen-mediated apoptosis of rheumatoid synovial cells in vitro by transforming growth factor beta 1

OBJECTIVE

To investigate the mitogenic and anti-apoptotic effects of transforming growth factor beta 1 (TGF beta 1) on rheumatoid synovial cells in vitro.

METHODS

Synovial cells were cultured with or without TGF beta 1. After incubation, the proliferative response of synovial cells and the expression of Fas antigen and bcl-2 on synovial cells were examined. Finally, Fas antigen-mediated apoptosis of synovial cells was investigated by the addition of anti-Fas antibody.

RESULTS

TGF beta 1 enhanced the proliferation of synovial cells in a dose-dependent manner. In addition, Fas antigen expression on synovial cells was inhibited by the addition of TGF beta 1 with up-regulation of bcl-2 expression. The addition of anti-Fas antibody induced synovial cell apoptosis. However, stimulation of synovial cells with TGF beta 1 became markedly resistant to Fas antigen-mediated apoptosis. The results were not affected by the addition of a neutralizing antibody to platelet-derived growth factor type AA (PDGF-AA), which suggests that the effect of TGF beta 1 on synovial cells was promoted via PDGF-AA-independent mechanisms.

CONCLUSION

Our results suggest that TGF beta 1 promotes synovial cell proliferation through its mitogenic effect on synovial cells and interference with the apoptotic process mediated by the Fas antigen, resulting in the perpetuation of the synovial hyperplasia in patients with rheumatoid arthritis.

Thyroid-stimulating hormone inhibits Fas antigen-mediated apoptosis of human thyrocytes in vitro

The mechanisms of TSH-induced growth stimulation of thyrocytes in vivo have yet to be elucidated. We examined the antiapoptotic effect of TSH toward Fas antigen-mediated apoptosis of thyrocytes. Fas antigen was expressed on approximately 40% of unstimulated thyrocytes, and the expression was significantly inhibited by the addition of TSH in a dose-dependent manner. Treatment of thyrocytes with 8-bromo-cAMP mimicked the effect of TSH, suggesting that the inhibitory effect of TSH on Fas antigen expression was mediated by activating protein kinase A. In contrast, treatment of thyrocytes with either interleukin-1 beta (IL-1 beta) or interferon- gamma (IFN gamma) markedly increased Fas antigen expression on thyrocytes, and these effects were inhibited in the presence of TSH. The expression of the protooncogene product Bcl-2 did not change after the addition of TSH, 8-bromo-cAMP, IL-1 beta, IFN gamma, or a combination of TSH and IL-1 beta or IFN gamma. When thyrocytes stimulated with either IL-1 beta or IFN gamma were treated with anti-Fas IgM mAb, the cells were committed to apoptosis, whereas this apoptotic process was significantly inhibited by the addition of TSH. These results indicate that the Fas antigen is functionally expressed on the surface of thyrocytes, and TSH inhibits Fas antigen-mediated apoptosis of thyrocytes through the inhibitory effect of Fas antigen expression, resulting in the promotion of growth of the thyroid gland.

Staphylococcal enterotoxin B-specific adhesion of murine splenic T cells to a human endothelial cell line

The presence of a putative autoantigen of autoimmune disorder in a target organ may cause accumulation of specific T cells in the inflammatory region. One of the mechanisms of such accumulation involves the migration of specific-circulating T cells through the endothelial cells into the target lesion. The presence of only a few specific T cells responsive to a putative autoantigen has hampered the investigation of specific migration of circulating T cells to the target organ. We used a superantigen to investigate specific T-cell adhesion to endothelial cells, because it stimulates a large proportion of T cells with particular V beta elements and adhesion of T cells to the endothelium is a vital step in the migration process. Adhesion of murine T cells to the human endothelial cell line, EA.hy926, was specifically increased in the presence of staphylococcal enterotoxin B (SEB). The increase was interferon-gamma (IFN-gamma)-dependent, and consisted mainly of CD4+ T cells. V beta 8.1,2+ T cells preferentially adhered to endothelial cells in the presence of SEB compared with V beta 6+ T cells. Pretreatment of endothelial cells with SEB increased the adherence of V beta 8.1,2+ T cells, while anti-human leucocyte antigen (HLA)-DR and -DQ antibodies inhibited the increased adherence of V beta 8.1,2+ T cells. Our results demonstrate that increased T-cell adhesion to endothelial cells is SEB specific, and that the specificity is dependent on major histocompatibility complex (MHC) class II molecules expressed on endothelial cells and on the recognition of the SEB-MHC class II complex by V beta 8.1,2+ T cells.

[Untoward effects of low dose methotrexate therapy in rheumatoid arthritis]

Sixty patients with rheumatoid arthritis who were administered weekly low dose methotrexate (MTX) were retrospectively analyzed for their untoward effects of MTX by interviewing to the patients and by the medical records. Cough and sputa were the most frequent symptoms (23.3%) and gastrointestinal symptoms were the next (20%). Five of 60 patients (8.2%) showed liver function test abnormalities, and four (6.7%) exhibited transient exacerbation of arthralgia for several hours to a few days after MTX administration. Three patients (5%) suffered from interstitial pneumonitis. Hair loss was seen in 3 patients (5%), and headache, leucocytepenia, fever, skin eruption, abnormal taste, hemorrhagic cystitis, and flashing were experienced in a patient, respectively. Three (5%) suffered from fungal infection, and herpes zoster, sepsis, and osteomyelitis were experienced in each one patient, respectively. MTX was withdrawn in three patients (5%) because of cough and sputa the drug was withdrawn in other three patients because of the interstitial pneumonia, and was drawn in another three patients because of transient exacerbation of arthralgia. The drug was withdrawn in each one patient, because of nausea and vomiting, skin eruption, osteomyelitis, and sepsis, respectively. Overall, MTX were withdrawn in 21 patients (35%), and, of those, 13 patients (21.7%) because of untoward effects and 8 patients (13.3%) because of the lack of efficacy.

Inhibitory effect of clarithromycin on costimulatory molecule expression and cytokine production by synovial fibroblast-like cells

This study was undertaken to investigate the immunomodulatory effect of clarithromycin against synovial fibroblast-like cells (synoviocytes). Synovial tissue obtained from rheumatoid arthritis (RA) or osteoarthritis (OA) patients was enzymatically digested to separate synoviocytes. The synoviocytes were cultured with or without cytokines in the presence of various concentrations of clarithromycin. The expression of costimulatory molecules was examined on the surface of the synoviocytes, using specific MoAbs and flow cytometry. The production of cytokines by synoviocytes was also measured using an immunoenzymatic assay. Finally, autologous T cells were stimulated by interferon-gamma (IFN-gamma)-treated synoviocytes in response to purified protein derivative (PPD). In some experiments, MoAbs specific for costimulatory molecules or clarithromycin were added and 3H-thymidine incorporation was counted. Intercellular adhesion molecule-1 (ICAM-1), LFA-3 and vascular cell adhesion molecule-1 (VCAM-1) were detected on the surface of both RA and OA synoviocytes. However, ICAM-2, B7-1 and B7-2 were not detected, and cytokines failed to induce these molecules. Both spontaneous and up-regulated expression of ICAM-1, LFA-3 and VCAM-1 by IFN-gamma, IL-1beta or 12-o-tetradecanoyl phorbol 13-acetate (TPA) were markedly suppressed by clarithromycin in a dose-dependent manner at concentrations between 0.1 and 10 microg/ml. The production of IL-1beta, IL-6, IL-8, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) but not IL-1alpha and tumour necrosis factor-alpha (TNF-alpha) by synoviocytes was detected. Clarithromycin significantly suppressed the production of these cytokines, but did not enhance IL-10 production. Finally, autologous T cells were stimulated by IFN-gamma-treated synoviocytes in response to PPD. As clarithromycin suppressed HLA-DR and costimulatory molecule expression was enhanced by IFN-gamma, autologous T cell proliferation was markedly inhibited by clarithromycin. Clarithromycin has a considerable immunosuppressive effect on synoviocytes by inhibiting costimulatory molecule expression, cytokine production and antigen-specific T cell proliferation induced by synoviocytes.

[A case of sensitive urethra treated by continent vesicostomy using detrusor tube]

A case of sensitive urethra treated with continent vesicostomy is reported. She suffered from atonic bladder due to a previous pelvic surgery and could not continue clean intermittent self-catheterization because of pain and discomfort, or sensitive urethra. Continent vesicostomy using detrusor tube following Mitrofanoff principle was performed. Postoperatively, the daily life activity improved markedly. Mitrofanoff operation is considered to be applicable to the cases with sensitive urethra after sufficient explanation and consent.

Cholinergic-glutamatergic interactions in visual recognition memory of rhesus monkeys

Administration of either a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801 (dizocilpine), or a muscarinic antagonist, scopolamine, produces dose-related impairments in performance of a visual recognition memory task, delayed non-matching to sample (DNMS) with lists of 20 symbols, in rhesus monkeys. In the present study, low doses of these two drugs, which were ineffective when given alone, significantly impaired performance when given in combination. Moreover, the effect was greater than additive, indicating a synergistic interaction. These results suggest that interactions between cholinergic and glutamatergic systems play an important role in regulation of visual recognition memory.

Fas antigen expression on synovial cells was down-regulated by interleukin 1 beta

Recent reports revealed that Fas antigen is functionally expressed on human synovial cells and apoptosis can be induced in these cells by anti-Fas antibody. We examined the effect of interleukin 1 beta (IL-1 beta) on Fas antigen-mediated apoptosis on human synovial cells in vitro. Using flowcytometric analysis, IL-1 beta inhibited Fas antigen expression on synovial cells in a dose-dependent fashion. No significant difference of Fas antigen gene expression between IL-1 beta-treated and untreated synovial cells was observed by RT-PCR analysis, suggesting that the inhibitory effect of Fas antigen expression by IL-1 beta is at posttranscriptional level. Apoptosis of synovial cells was easily induced by treatment of these cells with anti-Fas antibody. In contrast, pretreatment of synovial cells with IL-1 beta protected these cells against Fas antigen-mediated apoptosis. The expression of bcl-2 on synovial cells, known to interfere with the apoptotic process mediated by the Fas antigen, was not influenced by IL-1 beta. Our results suggest that IL-1 beta inhibits Fas antigen-mediated apoptosis of synovial cells and may perpetuate the hyperplasia of the synovium in patients with rheumatoid arthritis.

Regulation of very-low-density lipoprotein receptor in hypertrophic rat heart

To elucidate the regulation of very-low density-lipoprotein (VLDL) receptor, we have studied its gene expression in the heart of spontaneously hypertensive rats-stroke prone (SHR-SP, an animal model for hypertension-induced cardiac hypertrophy) compared with Wistar-Kyoto rats. RNase protection assay showed that ventricular VLDL receptor mRNA falls to 41% of normal levels at 4 weeks when hypertension is not yet fully developed, and drops further to 14% at 13 weeks, when cardiac hypertrophy is established. Lipoprotein lipase mRNA decreases in parallel with VLDL receptor mRNA. In cultured neonatal rat ventricular cardiomyocytes, VLDL receptor mRNA decreases in parallel with the process of cardiocyte hypertrophy during the 24 hours after treatment with 10-8 mol/L endothelin-1, falling to 40% of the initial value. These results demonstrate that there is downregulation of VLDL receptor gene expression in cardiac hypertrophy both in vivo and in vitro and suggest that the regulation of the VLDL receptor is possibly linked with the switch in energy substrate from lipid to glucose known to occur in cardiac hypertrophy.

Decreased expression of the very low density lipoprotein receptor mRNA in the cardiac ventricle of spontaneously hypertensive rats

1. To elucidate the functional implication of very low density lipoprotein (VLDL) receptor, we studied the gene expression of VLDL receptor in rats. The VLDL receptor mRNA was highly expressed in the cardiac ventricle and skeletal muscle. Intermediate amounts of VLDL receptor mRNA were detected in adipose tissue, adrenal gland, brain and lung. Thus the tissue distribution of VLDL receptor mRNA in rats was similar to that reported previously in rabbits. 2. We studied the gene expression of the VLDL receptor in the heart of stroke-prone spontaneously hypertensive rats (SHRSP), an animal model for hypertension-induced cardiac hypertrophy. RNase protection assay showed that the level of ventricular VLDL receptor mRNA was already decreased to one half when hypertension was not fully developed, and further diminished to one fifth when cardiac hypertrophy was established. 3. It is reported that energy utilization in SHRSP hypertrophied myocardium is impaired. Our results suggest that inactive fatty acid metabolism in the ventricle of SHRSP is related to the lowered expression of the VLDL receptor which is postulated as a gate for triglyceride-rich lipoprotein particle.

Changes in brain somatostatin in memory-deficient rats: comparison with cholinergic markers

To clarify the functional role of the brain somatostatinergic system in cognitive processes, changes in the performance in passive avoidance and water maze tasks and in brain somatostatin contents were comparatively investigated in young Fischer rats subjected to brain cholinergic and somatostatinergic depletion, and in aged Fischer rats. Lesioning of the nucleus basalis magnocellularis and administration of cysteamine (200 mg/kg, s.c.), a depletor of somatostatin, resulted in significant deficits in passive avoidance, but complete transection of the fimbria-fornix hardly affected the performance in the task. When cognitive performance was assessed in the Morris water maze, lesions of the nucleus basalis magnocellularis and the fimbria-fornix, and administration of cysteamine, significantly impaired the acquisition of navigatory spatial memories of rats. On the other hand, aged rats (24-27 months) showed severe impairments of memory acquisition in both tasks. Neurochemistry measurements showed that lesions of the nucleus basalis magnocellularis produced a selective reduction both in the cortical cholinergic marker choline acetyltransferase and in striatal somatostatin level, whereas lesioning of the fimbria-fornix caused a marked loss of choline acetyltransferase in the hippocampus and posterior cortex, and a significant reduction in hippocampal somatostatin. On the other hand, treatment with cysteamine significantly reduced the contents of somatostatin in all the brain regions examined, but minimally affected choline acetyltransferase activity. However, significant reduction in the striatal choline acetyltransferase activity and elevation in somatostatin content in the frontal cortex were found in aged rats compared with young rats. Taken together, these results strongly suggest that changes in the brain somatostatinergic transmission are involved in the cognitive deficits in the experimental animal models of dementia presently employed. Furthermore, the present comparative study further implies that there are differences in the relative involvement of the cholinergic and somatostatinergic systems in the performance of rats on two different tests of mnemonic function.

Transforming growth factor beta 1 induces apoptotic cell death in cultured human umbilical vein endothelial cells with down-regulated expression of bcl-2

Transforming growth factor beta 1 (TGF-beta 1) is a potent growth inhibitor of human umbilical vein endothelial cells (HUVEC). We investigated whether apoptosis is involved in the TGF-beta 1 mediated HUVEC growth inhibition. Using immunofluorescence microscopy and staining by propidium iodide, we showed HUVEC treated with TGF-beta 1 contained characteristic apoptotic nuclei with condensation of chromatin. FACS analysis demonstrated that the number of cells with hypodiploid DNA contents were increased in HUVEC treated with TGF-beta 1. The DNA fragmentation assay exhibited typical ladder formation in TGF-beta 1-treated HUVEC. Using Western blot analysis, the expression of bcl-2 on HUVEC was down-regulated by TGF-beta 1-treatment. These findings suggest that TGF-beta 1 regulates the growth of HUVEC by inducing apoptosis accompanied with down-regulation of bcl-2 expression.

Involvement of raphe-hippocampal serotonergic and septo-hippocampal cholinergic mechanisms in the penile erection induced by FR121196, a putative cognitive enhancer

FR121196 (N-[4-acetyl-1-piperazinyl]-4-fluorobenzenesulfonamide), a putative cognitive enhancer, induced penile erection in naive rats; the dose-response curve was bell-shaped with the maximum response obtained at the dose of 3.2 mg/kg. The response to FR121196 was abolished in rats treated with intra-raphe injections of 5,7-dihydroxytryptamine or systemic injections of p-chlorphenylalanine (150 mg/kg, i.p. for three consecutive days) as well as in rats with electrolytic medial-septum lesion or surgical fimbria-fornix lesion. In addition, the penile erection induced by FR121196 (3.2 mg/kg) was dose-dependently attenuated by pindolol (0.1-3.2 mg/kg), a serotonin (5-HT)1 antagonist with beta-antagonistic activity, but not by metoprolol, a selective beta=antagonist. The inhibitory activity was shared by ICS205-930, a 5-HT3 antagonist, but not by ketanserin, a 5-HT2 antagonist, or sulpiride, a dopamine D2 antagonist. Scopolamine (0.032-1 mg/kg), but not methyl-scopolamine (0.032-1 mg/kg), also attenuated the penile erection induced by FR121196. Neurochemical analysis revealed that intraperitoneal injection of FR121196 significantly elevated the levels of 5-HT and its major metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the hippocampus and that raphe-lesion significantly reduced both 5-HT and 5-HIAA levels without affecting choline-acetyltransferase activity in all cortical and subcortical regions examined. It is thus postulated that FR121196 facilitates the raphe-hippocampal serotonergic pathway resulting in an activation of the septo-hippocampal cholinergic pathway and finally induces the penile erectile response.

Cellular immunity in autoimmune thyroid disease

Autoimmune thyroid disease occurs in a genetically susceptible patient after triggering events including bacterial and viral infections, environmental insults, drugs or hormones. These triggering events may break the tolerance to self-antigen, leading to emergence of autoreactive T cells. One or more T cell clones that recognize the self-antigen is(are) assumed to be involved in initiating autoimmune processes. Following this, T cell clones expand and migrate from the peripheral blood into the thyroid gland. Migration of mononuclear cells is controlled by inflammatory cytokines and adhesion molecules. Intrathyroidal T cells may interact with dendritic-like cells, thyrocytes expressed with HLA-DR antigens, B cells and extracellular matrix, resulting in the proliferation of T cells, production of cytokines and autoantibodies. These interactions are also regulated by inflammatory cytokines and adhesion molecules. When the initial immune response is completed, a secondary immune response ensues, that may be of considerable complexity involving reaction of infiltrating T cells to a variety of tissue-specific and tissue-non-specific antigens. These immune responses may contribute to the recurring immunologic activity and maintenance of autoantibody overproduction.

FR121196, a potential antidementia drug, ameliorates the impaired memory of rat in the Morris water maze

We investigated the effects of FR121196 N-(4-acetyl-1-piperazinyl)-4-fluorobenzenesulfonamide on the performance of rats in the Morris water maze using a two-trial-per-day regimen. Escape latency to find the platform was significantly prolonged in young rats subjected to scopolamine (1 mg/kg) treatment or to nucleus basalis magnocellularis (NBM) or fimbria-fornix (FF) lesioning compared with the respective control animals. Similar memory deficit was observed in aged rats (24-26 months old) compared with young rats. Daily treatment with FR121196 (0.1-1.0 mg/kg i.p.) ameliorated all the memory deficits except in the FF-lesioned rats, whereas physostigmine (0.032-0.32 mg/kg) ameliorated the memory deficits in scopolamine-treated rats but not in the NBM-lesioned, FF-lesioned or aged rats. Methamphetamine (0.32-3.2 mg/kg) hardly ameliorated the memory deficits and, rather, aggravated those in the scopolamine-treated, NBM-lesioned and aged rats. Neurochemical analysis of the brain showed that dopamine, norepinephrine and serotonin levels were significantly reduced in the hippocampus of the FF-lesioned rats compared with the sham control, and a significant reduction of dopamine level in the cortex was also observed in the aged rats compared with young rats. None of these parameters were changed after NBM lesioning. We concluded that FR121196 ameliorates the memory deficits of rats with cholinergic dysfunction through the action on the hippocampal monoaminergic (possibly serotonergic) neurons.

Endogenous antigen presentation by autoantigen-transfected Epstein-Barr virus-lymphoblastoid cells: T cell receptor N-region hydrophobicity relates to thyroid antigen recognition

Seven human T cell lines from a patient with Graves' disease were raised against endogenously generated human thyroid peroxidase (hTPO) with stimulation indices ranging from 2.1 to 7.6. Clonal expansion within these T cell lines was demonstrated by sequencing multiple bacterial colonies containing RT-PCR-generated fragments derived from the expressed hTcRs. Some lines had more than one human T cell receptor (hTcR) alpha and beta chain mRNAs as judged by RT-PCR. Stopcodons present in several hTcR sequences indicated that only one V alpha and one V beta gene were translated. Both the V alpha/beta gene families and the J alpha/beta gene segments differed amongst the lines and no characteristic recognition sequences were discernable in the CDR3 regions. Using Kyte-Doolittle analysis we found hydrophobic peaks in most N alpha-regions (but not N beta regions) suggesting that hydrophobic interactions may be important in the recognition of hTPO. However, increasing affinity values, as measured by SI, were strongly correlated with decreasing hydrophobicity in the N alpha region (1st order regression, r = -0.93138, p < 0.01). Thus, lower affinity, self-reactive, T cells may be more hydrophobic ('sticky') in their N alpha regions while higher affinity cells may be characterized by TcRs with lower hydrophobicity. These findings demonstrate a substantial role for hydrophobic interactions in hTPO-reactive T cell receptors and further support a role for the TcR alpha chain in the recognition of thyroid autoantigen.