Selective regulation of T cell IL-5 synthesis by OM-01, JTE-711 and p38 MAP kinase inhibitor: independent control of Th2 cytokines, IL-4 and IL-5

BACKGROUND: Helper T cells are involved in chronic eosinophilic inflammation. Control of cytokine production seems to be an effective management. METHODS: The effect of nonactin, SB203580, a p38 MAP kinase inhibitor, and JTE-711 on the cytokine production of allergen-specific T cell clones was determined. The effect of nonactin on the airway eosinophilia was investigated using murine asthma model. RESULTS: Nonactin suppressed IL-5 synthesis by human Th cells in a dose-dependent manner without affecting IL-2 or IL-4 synthesis, and still significantly suppressed murine airway eosinophilia induced by the antigen inhalation. SB203580 and JTE-711 also selectively inhibited IL-5 synthesis in vitro. CONCLUSION: Synthesis of IL-5 by human Th cells can be differentially regulated from that of other major T cell cytokines. The in vivo effects of selective IL-5 synthesis inhibitors suggest that IL-5 is the reasonable target for the regulation of allergic disorders accompanied by eosinophilic inflammation.     

Histamine downregulates CD14 expression via H2 receptors on human monocytes

Lipopolysaccharide (LPS) binds to LPS-binding protein (LBP) in plasma and is delivered to the cell surface receptor CD14 on human monocyte. LPS is transferred to the transmembrane signaling receptor toll-like receptor (TLR) 4. In the present study, the effect of histamine on the expression of CD14 on human monocytes was investigated. Histamine concentration- and time-dependently decreased the expression of cell surface CD14, whereas histamine did not decrease mRNA for CD14 nor increase soluble CD14 (sCD14). The inhibitory effects of histamine on CD14 expression were antagonized by H2-receptor antagonist, but not by H1 and H3/H4 antagonist. The effects of selective H2-receptor agonists, 4-methylhistamine and dimaprit, on CD14 expression mimicked that of histamine indicating that histamine regulated CD14 expression through the stimulation of H2-receptors. The pretreatment with histamine partially inhibited the LPS-induced TNF-alpha production in human peripheral blood mononuclear cells (PBMC). Such inhibition might be due to the down-regulation of CD14 expression on monocytes by histamine.     

Simultaneous occurrence of medullary and follicular carcinoma in the same thyroid lobe

A rare case of the simultaneous development of medullary and follicular carcinoma of the thyroid gland in a 51-year-old Japanese woman is examined. A preoperative diagnosis was made by needle aspiration cytology. Neoplastic cells of the medullary carcinoma were positive for calcitonin and carcinoembryonic antigen, whereas the tumor cells of the follicular carcinoma were negative for these substances. This case presents evidence that, in rare cases, two malignant epithelial neoplasms of different origins can occur in the same lobe of the thyroid.     

Analysis of sensitization to carboxymethylcellulose: Identification of high risk group using ELISA and histamine release experiment

Objective and Design: Carboxymethylcellulose (CMC) has been considered to be inert and is commonly used as an additive in medicines, foods and cosmetics. However, we experienced a patient who developed an anaphylactic reaction to CMC after an upper gastrointestinal examination using a barium meal containing CMC. Therefore, we examined the incidence of sensitization by CMC in healthy subjects, and categorized the high risk group prone to developing anaphylactic response to CMC.Methods: An ELISA for detecting CMC-specific IgE antibody was developed using serum from the patient as a positive control. In the ten subjects exhibiting high anti-CMC IgE among 387 normal populations, histamine release from isolated leukocytes was performed.Results: Five of ten subjects with a high IgE titer showed a significant CMC-induced histamine release from leukocyte preparations in vitro as observed in the patient, and were classified as high risk group. There was a correlation between sensitization by CMC and that by Japanese cedar pollen. The incidence of sensitization in females was 2.4 fold higher than that in males.Conclusions: The combination of ELISA and histamine release experiment made it possible to identify the high risk group for developing anaphylactic response. The administration of high dose CMC as a suspending agent in barium sulfate or injectable corticosteroids to this group should be avoided to prevent anaphylactic reactions in the clinic.Received 18 August 2003; returned for revision 29 September 2003; accepted by M. J. Parnham 10 December 2003     

Two-week, but not 1-week, hypoxic exposure enhances nitric oxide-mediated basal tone regulation in rat resistance pulmonary arteries

We measured internal diameter (ID) changes in resistance and conduit pulmonary arteries of 1- and 2-week hypoxic rats and normoxic control rats in response to nitric oxide synthase (NOS) inhibitors in vivo. At 2 weeks of hypoxic exposure, the ID reduction as a result of NOS inhibition was enhanced within the resistance arteries, but not at 1 week of hypoxia.     

Practical application of nutritional assessment protein and inflammatory marker in the nutrition support team (NST)

Recently nutrition support team (NST) has been established for the purpose of prevention of complications which are caused by nutrition disorders and reduction of the medical expenses. Although physical examinations and blood biochemical data had been used as the indexes evaluating nutritional of patients, they were not suitable for the evaluation for the short-term in-patient. On the contrary, serum albumin (ALB) has been wildly used as a nutritional marker. However, it is impossible to evaluate nutrition state for the short-term in-patient and acute phase disease patient accurately, because the plasma half-life is 21 days and it takes long time to detect the change in nutritional state by its value. Rapid turnover proteins (RTP), whose plasma half-life is shorter, has paid attention to evaluate nutritional state for the short-term in-patients and acute phase disease patients. Although, prognostic inflammatory and nutritional index (PINI) was considered as a useful maker for evaluating inflammatory and nutritional states using the concentrations of transthyretin (TTR), a RTP, alpha1-acid glycoprotein (alpha1-AG), a chronic inflammation marker, C reactive protein (CRP), a acute inflammation marker, and ALB, However, it has several pitfalls. We newly made serum amyloid A (SAA) index using SAA instead of CRP. When we compared SAA index with PINI in many diseases, it turned out that SAA index became a more effective index which reflected the patient condition than did PINI. As for this index, it is expected to be used by NST while further alternation may be needed.     

Doxorubicin, an RNA synthesis inhibitor, prevents vasoconstriction and inhibits aberrant expression of endothelin-1 in the cerebral vasospasm model of the rat

The present study investigates the effects of bis(7)-tacrine, a novel dimeric acetylcholinesterase inhibitor, on hydrogen peroxide(H₂O₂)-induced cell injury with comparison to the corresponding monomer, tacrine. Exposure of rat pheochromocytoma line PC12 cells to H₂O₂ induced significant cell damage. This reagent also caused redox desequilibrium as indicated by a decrease in activities of intracellular antioxidant enzymes such as glutathione peroxidase as well as catalase and an accumulation of malondialdehyde, a product of lipid peroxidation. Pretreatment of cells with bis(7)-tacrine or tacrine attenuated H₂O₂-induced cell toxicity, and bis(7)-tacrine demonstrated higher potency than tacrine in improving redox desequilibrium. These results suggest that bis(7)-tacrine and tacrine significantly protect against H₂O₂ insult, which might be beneficial for their potential usage in the prevention and treatment of Alzheimer's disease.     

Hemorrhages of dorsal root ganglia and spinal cord in congenitally hydrocephalic HTX rat

The effects on the brain caused by hydrocephalus have been examined in detail. However, only little attention has been paid to the possibility that hydrocephalus may affect the spinal cord and the spinal ganglia via the spinal canal. Therefore, the present study focused on the pathological changes seen in the spinal cord and the dorsal root ganglia. A total of 651 congenitally hydrocephalic HTX rats were used in this study. The age ranged from postnatal day 0 to postnatal day 520. All of the HTX rats were from littermates raised in our laboratory. Macroscopic and microscopic investigations demonstrated hemorrhages of the dorsal root ganglia in 134 rats among the 235 affected HTX rats. The hemorrhages of the dorsal root ganglia were observed most frequently in the lumbar ganglia and, less frequently, in the cervical ganglia. Of the 134 rats with hemorrhages in the dorsal root ganglia, 34 rats had hemorrhages both in the spinal cord and in the dorsal root ganglia. The spinal cord hemorrhages were distributed mainly around the central canal and in the ventral parts of the posterior funiculus at the lower thoracic and upper lumbar cords. These hemorrhages were seen only in those rats having progressive hydrocephalus. These findings suggest that increased cerebrospinal fluid pressure can cause congestion of the radicular veins, leading to hemorrhages of the spinal cord and the dorsal root ganglia.     

Immunohistochemical evaluation of the neurotoxic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on dopaminergic nigrostriatal neurons of young adult mice using dopamine and tyrosine hydroxylase antibodies

The recovery of dopamine (DA) neurons in young adult mice from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) damage was analyzed at various times after MPTP treatment with DA and tyrosine hydroxylase (TH) immunohistochemistry and also by chemical DA assay. A remarkable discrepancy in the recovery rate of DA and TH reactivities of the nigral neurons was observed: the TH immunoreactivities of both cell bodies in the substantia nigra and terminals in the neostriatum were markedly reduced 4 days after MPTP. However, these reactivities progressively improved and almost fully recovered after 25 days, while the DA immunoreactivities were maximally depleted 10 days after, and the depletion continued even through the 25th day. The alteration of DA levels was correlated with that of DA immunoreactivity. These findings suggest that a major effect of MPTP on the DA neurons of young adult mice is a transient neurotoxicity, and that the TH content improves more promptly than that of DA.