Neuron-immune interactions in the sensitized thalamus induced by mustard oil application to rat molar pulp

We have reported that mustard oil application to the rat dental pulp induces neuronal activation in the thalamus. To address the mechanisms involved in the thalamic changes, we performed neuronal responsiveness recording, immunohistochemistry, and molecular biological analysis. After mustard oil application, neuronal responsiveness was increased in the mediodorsal nucleus. When MK801 (an N-methyl-D-aspartate receptor antagonist) was applied to the mediodorsal nucleus, the enhanced responsiveness was decreased. N-methyl-D-aspartate receptor 2D, glial fibrillary acidic protein, and antigen-presenting cell-related gene mRNAs in the contralateral thalamus were up-regulated at 10 minutes after mustard oil application, but were down-regulated within 10 minutes after the antagonist application. OX6-expressing microglia and glial fibrillary acidic protein-expressing astrocytes did not increase until 60 minutes after mustard oil application. These results suggested that the thalamic neurons play some roles in regulating the glial cell activation in the mediodorsal nucleus via N-methyl-D-aspartate receptor 2D during pulp inflammation-induced central sensitization.

A CONTRIBUTION TO THE ETIOLOGY AND PATHOLOGY OF RAT-BITE FEVER

Of the two postmortem examinations on rat-bite fever previously reported, the patient of Miura and Toriyama, a woman, aged 32 years, died on the 70th day after the onset of the disease. Anatomically there were no marked changes. Histological examinations were not made. Macroscopically, the following findings are reported: increase of cerebrospinal fluid, hyperemia of the meninges, inflammatory edema of the lungs, cloudy swelling of the liver, etc. The other, Blake's case, was a woman of 67, who died 1 month after the bite of a rat. The anatomical findings were acute ulcerative endocarditis, subacute myocarditis, interstitial hepatitis, glomerular and interstitial nephritis. The suprarenals contained a large amount of perivascular fluid. There were infarcts in the spleen and kidney. In general, the organs were hyperemic; the lung showed hemorrhages and edema, Histologically, Blake found marked degeneration, necrosis, and infiltration in the cardiac muscles, infiltration of polynuclear cells, and increase in the interstices of the liver, also marked polynuclear infiltration of the shrunken kidney.

Clinico-epidemiologic study of the metabolic syndrome and lifestyle factors associated with the risk of colon adenoma and adenocarcinoma

BACKGROUND

The numbers of patients with colorectal cancer and associated deaths have been increasing in Japan, probably due to rapid lifestyle changes. Prevention is clearly important and the present study aimed to clarify risk factors and to promote colon cancer screening.

METHODS

We investigated lifestyle factors, biochemical data, and pathological features of 727 individuals who underwent colonoscopy. Data were subjected to statistical analysis using SPSS software.

RESULTS

Low-grade adenoma was more frequent among the elderly and in men. All of the men and 87.5% of the women with high-grade adenoma or adenocarcinoma were aged≥45 and≥50 years, respectively. In women, a larger waist circumference (=80 cm) increased the odds ratio for colon adenoma or adenocarcinoma (colon tumors) by 1.033 (95% confidence index (CI), 1.001-1.066; p=0.040). Metabolic syndrome significantly increased the odds ratio of colon tumors in men, but not in women. Cigarette smoking, drinking alcohol, and increased physical activity were significant risk factors for colon tumors in men, with odds ratios of 1.001 (95% CI, 1.000-1.002; p=0.001), 1.001 (95% CI, 1.000-1.003; p=0.047), and 1.406 (95% CI 1.038-1.904; p=0.028), respectively.

CONCLUSIONS

Colon tumors have a high prevalence in the elderly. A larger waist circumference in women and metabolic syndrome in both men and women elevate the risk of colon tumors. In addition, smoking, drinking, and excessive physical activity are risk factors for adenoma and adenocarcinoma in men. For early detection of colorectal cancer, men older than 45 years and women older than 50 years with these risk factors are recommended to undergo colonoscopy.

Activation of p38 mitogen-activated protein kinase is required for in vivo brain-derived neurotrophic factor production in the rat hippocampus

Several lines of evidence strongly suggest that brain-derived neurotrophic factor (BDNF) is associated with the formation, storage and recall of memory in the hippocampus and that it is important to maintain a considerable level of hippocampal BDNF in order to keep normal functions. BDNF can be synthesized in an activity-dependent manner. In fact, kainic acid or AMPA enhances BDNF levels in hippocampal granule neurons. However, the mechanisms of BDNF production are largely unclear. Recently, we have found that riluzole, which blocks voltage-gated sodium channels and thereby reduces glutamate release, actually strengthens immunoreactivity of BDNF in hippocampal granule neurons of rats. Therefore, we examined the riluzole-activated signaling pathways for BDNF production. Riluzole increased levels of phospho-p38 mitogen-activated protein kinase (p38 MAPK), as well as BDNF levels. Inhibition of p38 MAPK by SB203580 reduced riluzole effects, while activation of p38 MAPK by anisomycin increased levels of BDNF, suggesting that p38 MAPK can mediate BDNF production. Riluzole-induced elevation of phospho-activating transcription factor-2, a transcription factor downstream of p38 MAPK, was also observed. A blocker of N-type voltage-gated calcium channels reduced the effects of riluzole on BDNF production and p38 MAPK activation. We also examined a possible involvement of the adenosine A1 receptor in BDNF production because riluzole can influence ecto-nucleotide levels. An A1 receptor agonist inhibited riluzole-induced elevation of BDNF levels, whereas an antagonist not only increased levels of BDNF and active p38 MAPK but also augmented riluzole effects. These results indicate that, in the rat hippocampus, there is an in vivo signaling pathway for BDNF synthesis mediated by p38 MAPK, and that N-type voltage-gated calcium channels and/or adenosine A1 receptors contribute to p38 MAPK activation.

Antigen-presenting cells in human radicular granulomas

Substantial numbers of dendritic cells have been detected in radicular granulomas. To test the hypothesis that local antigen presentation from dendritic cells to T-cells is involved critically in immunological responses within radicular granulomas, we compared characteristics of dendritic cells and macrophages by morphological and biological analyses. Under light microscopy, HLA-DR+ and CD68+ cells showed diverse profiles, including dendritic-shaped cells. Transmission electron microscopy revealed that HLA-DR+ dendritic cells, with long cytoplasmic processes and lacking distinct phagosomes, were concentrated in the lymphocyte-rich area. HLA-DR alpha-chain, CD83, and CD86 mRNAs from HLA-DR+ dendritic cells, and CD28 mRNA from CD28+ T-cells were up-regulated in lymphocyte-rich area. Scanning electron microscopy demonstrated that the density of gold particles on dendritic cells was higher than that on HLA-DR+ macrophages. These results suggest that dendritic cells in radicular granulomas are associated with local defense reactions as stronger antigen-presenting cells, as compared with macrophages.

CD30+ large cell transformation of mycosis fungoides after psoralen plus ultraviolet A photochemotherapy

Psoralen plus ultraviolet A (PUVA) photochemotherapy is widely used for the therapy of mycosis fungoides (MF). Clinical progression of MF is often associated with an increase in the size of tumour cells known as transformation. We report two patients with CD30+ large cell transformation that appeared after low-dose PUVA therapy for MF. Clinical data, histopathology, immunohistopathology and T-cell receptor gene rearrangement were studied. Nodules consisted of atypical large cells that expressed CD30. Monoclonal rearrangement of T-cell receptors was observed in one case. Low-dose PUVA therapy may be associated with CD30+ large cell transformation in patients with MF.

Idiopathic acquired generalized anhidrosis due to occlusion of proximal coiled ducts

Idiopathic acquired generalized anhidrosis is a very rare disease of unknown pathogenesis. We report a 25-year-old man with acquired generalized anhidrosis due to occlusion of the coiled ducts. He did not have sweat secretion over the entire surface of the body, including the palms and soles. Sweat-inducing stimuli provoked tingling pain on the skin. Pilocarpine iontophoresis on the forearm did not induce sweat secretion. Neurological examination did not reveal any abnormality in the central or peripheral nervous system. Skin biopsy showed that the coiled ducts were occluded by an amorphous eosinophilic substance. This amorphous eosinophilic substance was positive with periodic acid-Schiff (PAS) staining and was resistant to digestion by diastase. Electron microscopy demonstrated that the coiled ducts were completely occluded by an amorphous substance. The substance occluding the coiled ducts contained fibrous structures. These findings suggested that the acquired generalized anhidrosis in this patient was caused by occlusion of the coiled ducts by a PAS-positive substance probably derived from dark cell granules.

Curative treatment of central hemangioma in the mandible by direct puncture and embolisation with n-butyl-cyanoacrylate (NBCA)

Management of central hemangioma in the mandible is difficult because of the abundant vascular network in this region. One of the most common signs of these patients, especially in the mixed dentition period, is hypermobility of the teeth with spontaneous hemorrhage from the surrounding gingival sulcus. Various therapeutic modalities have been considered, but surgery is the most frequently used. In cases of a large extensive lesion, however, intralesional injections of sclerosing agents have often been successful. A case of central hemangioma of the mandible with arteriovenous malformations in a 10-year-old girl is reported. She was treated with direct injection of an embolic material, n-butyl-cyanoacrylate, which brought satisfactory results. Preoperative embolisation of feeder vessels with Gelfoam and Avitene soaked in thrombin together with this direct injection is a safe treatment modality that is as effective as surgery.

An enzymatic cycling method for the measurement of myo-inositol in biological samples

INTRODUCTION

A sensitive and simple enzymatic cycling method is described for the quantitation of myo-inositol in biological samples.

METHODS

The method involves the use of a sensitive and simple enzymatic cycling method is described for the quantitation of myo-inositol in biological samples. The method involves use of thio-NAD(+), NADH and thermostable myo-inositol dehydrogenase (IDH; EC. 1.1.1.18) and measurement of the increase in absorbance at 405 nm of thio-NADH at 37 degrees C.

RESULTS

The calibration curve for myo-inositol was linear (r=1.00) between 10 and 400 micromol/l. Analytical recoveries of exogenous myo-inositol added to serum and urine were 100-105% and 98-103%, respectively. Within-run and between-run coefficient of variation (CV) were 0.6-2.1% and 1.1-3.0%, respectively. This method was free from interference by hemoglobin, bilirubin, ascorbate, chyle, various sugars, sugar alcohol and myo-inositol phosphates. With the use of myo-inositol as a standard solution, the serum myo-inositol concentration (mean+/-SD) was significantly greater in patients with diabetes mellitus (DM) without nephropathy (73.0+/-13.8 micromol/l, n=7) than in healthy individuals without DM (61.0+/-12.4 micromol/l, n=20). The urinary myo-inositol concentration was also significantly greater in patients with DM without nephropathy (793.3+/-870.3 micromol/l, n=7) than in healthy individuals without DM (76.0+/-63.0 micromol/l, n=13).

CONCLUSIONS

This new method is simple, sensitive and enables quantitative analysis of myo-inositol.

Terminal deoxynucleotidyltransferase is negatively regulated by direct interaction with proliferating cell nuclear antigen

BACKGROUND

The repertoires of Ig and TcR are generated by a combinatorial rearrangement of variable (V), diversity (D), and joining (J) segments (V(D)J recombination) in B- and T-cells. Terminal deoxynucleotidyltransferase (TdT) adds extra nucleotides (N nucleotides) at the junctions of the gene segments to enhance the Ig and TcR genes diversity. Using an anti-TdT antibody column, TdT has been purified as a member of a megadalton protein complex from rat thymus. The N region would be synthesized with the large protein complex.

RESULTS

The cDNAs for proliferating cell nuclear antigen (PCNA) were isolated by yeast two-hybrid screening as the gene products which directly interacted with TdT. The interaction between PCNA and TdT was confirmed by co-immunoprecipitation, both in vitro and in vivo. TdT binds directly to a PCNA trimer, as shown by gel filtration. TdT interacts with PCNA in its DNA polymerization domain (DPD), but not in its BRCA-1 C-terminal (BRCT) domain. TdT activity was reduced to 17% of the maximum value by TdT/PCNA complex formation.

CONCLUSION

TdT interacts directly with PCNA through its DPD. A functional consequence of this interaction is the negative regulation of TdT activity. These findings suggest that TdT catalyses the addition of N nucleotides under the negative control of PCNA during V(D)J recombination.

Terminal deoxynucleotidyltransferase directly interacts with a novel nuclear protein that is homologous to p65

BACKGROUND

Terminal deoxynucleotidyltransferase (TdT) is a DNA polymerase that enhances Ig and TcR gene diversity in the N region in B- and T-cells. TdT is found as a member of a large protein complex in the lysate of the thymocytes. To elucidate the molecular mechanism of the synthesis of the N region, we first attempted to isolate the genes with products that are interacting directly with TdT.

RESULTS

Using a yeast two-hybrid system, we isolated a cDNA clone encoding a novel nuclear protein that interacts with TdT. This protein was designated as TdT interacting factor 1 (TdIF1). TdIF1 has a high degree of homology to the transcription factor p65, which belongs to the nuclear receptor superfamily. TdIF1 contains HMG-I and HMG-Y DNA binding domains (AT-hooks) and can bind to single- and double-stranded DNA. TdT and TdIF1 were co-eluted at position 232 kDa by gel filtration of MOLT4 lysate. TdIF1 can enhance TdT activity fourfold in vitro assay system using oligo(dT)16 as primers.

CONCLUSIONS

TdIF1 binds directly to TdT, both in vitro and in vivo. TdIF1 and TdT exist as the members of a 232 kDa protein complex. TdIF1 can enhance TdT activity maximum fourfold in vitro assay system, suggesting that it positively regulates the synthesis of the N region during V(D)J recombination in the Ig and TcR genes.

Structure-sweetness relationship in thaumatin: importance of lysine residues

To clarify the structural basis for the sweetness of thaumatin I, lysine-modified derivatives and carboxyl-group-modified derivatives were prepared by chemical modification followed by chromatographic purification. The sweetness of derivatives was evaluated by sensory analysis. Phosphopyridoxylation of lysine residues Lys78, Lys97, Lys106, Lys137 and Lys187 markedly reduced sweetness. The intensity of sweetness was returned to that of native thaumatin by dephosphorylation of these phosphopyridoxylated lysine residues except Lys106. Pyridoxamine modification of the carboxyl group of Asp21, Glu42, Asp60, Asp129 or Ala207 (C-terminal) did not markedly change sweetness. Analysis by far-UV circular dichroism spectroscopy indicated that the secondary structure of all derivatives remained unchanged, suggesting that the loss of sweetness was not a result of major disruption in protein structure. The five lysine residues, modification of which affected sweetness, are separate and spread over a broad surface region on one side of the thaumatin I molecule. These lysine residues exist in thaumatin, but not in non-sweet thaumatin-like proteins, suggesting that these lysine residues are required for sweetness. These lysine residues may play an important role in sweetness through a multipoint interaction with a putative thaumatin receptor.

Sweetness of sweet protein thaumatin is more thermoresistant under acid conditions than under neutral or alkaline conditions

Thermostability of thaumatin and mechanisms of thermoinactivation were examined at 80 degrees C in the pH range from 2 to 10. The sweetness of thaumatin disappeared on heating at pH above 7 for 15 min, but the sweetness remained even after heating at 80 degrees C for 4 h at pH 2. This indicated that the sweet protein thaumatin is more thermoresistant under acid conditions than under neutral or alkaline conditions. Prolonged heating of thaumatin under acid conditions slowly reduced sweetness, and produced a heterogeneous population of molecules, all of which was soluble and monomeric. The resultant molecules were clearly distinct from those generated by heating at pH above 7. Hydrolysis of peptide bonds and other irreversible chemical reactions slowly took place in the molecule heated under acid conditions, and it would be, in part, a cause of thermoinactivation of thaumatin under acid conditions. The thermostability of thaumatin and the mechanism of thermoinactivation were largely dependent on pH.