High sensitivity cardiac troponin T is a useful biomarker for predicting prognosis of the patients with sarcoidosis

Background

Cardiac involvement is one of the most significant prognostic factors for the patients with sarcoidosis. In spite of the advancement of diagnostic tools, such as cardiac magnetic resonance imaging or 18F-fluoro-2-deoxyglucose positron emission tomography, there is still significant room for improvement in cardiac screening and prognostic prediction.

Purpose

To evaluate the prognostic factors for the patients with sarcoidosis.

Methods and results

We prospectively studied 133 patients with sarcoidosis and evaluated clinical data including biomarkers. The mean age at diagnosis was 62.1±12.8 years. During a mean follow up period of 5.6±4.1 years, nine patients died and 27 patients suffered from cardiac events (cardiac death, heart failure admission, arrhythmic event). We divided patients into two groups according to cardiac events, event group had high serum high-sensitivity cardiac troponin T (hs-cTnT) (0.028±0.017 vs. 0.015±0.011 ng/ml, p<0.001), high BNP (409.2±634.0 vs. 122.4±195.8 pg/ml, p<0.001), low EF (43.1±16.4 vs. 59.2±15.5%, p<0.001). This was observed even if those patients were not diagnosed with cardiac involvement at the enrollment. On the other hand, there were no significant differences in the values of angiotensin-converting enzyme, lysozyme, soluble interleukin-2 receptor, or calcium in both groups. Multivariate analysis revealed that hs-cTnT was an independent biomarker to predict cardiac events (hs-cTnT >0.014 ng/ml: HR 3.2, 95% CI 1.02 to 10.19, p=0.046).

Conclusion

Hs-cTnT was a useful biomarker for predicting cardiac events for the patients with sarcoidosis even if cardiac involvement was not detected at initial evaluation.

Figure 1

Funding Acknowledgement

Type of funding source: None

The rice endosperm ADP-glucose pyrophosphorylase large subunit is essential for optimal catalysis and allosteric regulation of the heterotetrameric enzyme

Although an alternative pathway has been suggested, the prevailing view is that starch synthesis in cereal endosperm is controlled by the activity of the cytosolic isoform of ADPglucose pyrophosphorylase (AGPase). In rice, the cytosolic AGPase isoform is encoded by the OsAGPS2b and OsAGPL2 genes, which code for the small (S2b) and large (L2) subunits of the heterotetrameric enzyme, respectively. In this study, we isolated several allelic missense and nonsense OsAGPL2 mutants by N-methyl-N-nitrosourea (MNU) treatment of fertilized egg cells and by TILLING (Targeting Induced Local Lesions in Genomes). Interestingly, seeds from three of the missense mutants (two containing T139I and A171V) were severely shriveled and had seed weight and starch content comparable with the shriveled seeds from OsAGPL2 null mutants. Results from kinetic analysis of the purified recombinant enzymes revealed that the catalytic and allosteric regulatory properties of these mutant enzymes were significantly impaired. The missense heterotetramer enzymes and the S2b homotetramer had lower specific (catalytic) activities and affinities for the activator 3-phosphoglycerate (3-PGA). The missense heterotetramer enzymes showed more sensitivity to inhibition by the inhibitor inorganic phosphate (Pi) than the wild-type AGPase, while the S2b homotetramer was profoundly tolerant to Pi inhibition. Thus, our results provide definitive evidence that starch biosynthesis during rice endosperm development is controlled predominantly by the catalytic activity of the cytoplasmic AGPase and its allosteric regulation by the effectors. Moreover, our results show that the L2 subunit is essential for both catalysis and allosteric regulatory properties of the heterotetramer enzyme.

Preoperative routine evaluation of bilateral adrenal glands by endoscopic ultrasound and fine-needle aspiration in patients with potentially resectable lung cancer

BACKGROUND AND STUDY AIMS

The aim of the current study was to assess the detection rate of the right adrenal gland and the diagnostic ability of endoscopic ultrasound (EUS) and fine-needle aspiration (FNA) for the diagnosis of adrenal metastasis in potentially resectable lung cancer.

PATIENTS AND METHODS

This retrospective cohort study included a consecutive series of 150 patients undergoing EUS/EUS - FNA for staging of lung cancer. The detection rate of the right adrenal gland by EUS and the diagnostic accuracies of computed tomography (CT), positron emission tomography-CT (PET-CT), and EUS/EUS - FNA for the diagnosis of adrenal metastasis were evaluated.

RESULTS

The right adrenal gland was visualized by EUS in 131 patients (87.3 %); the left adrenal gland was visualized in all patients. Findings suggestive of metastasis in either one of the adrenal glands or in both were observed in 6 patients (4.0 %) by CT, in 5 patients (3.3 %) by PET-CT, and in 11 patients (7.3 %) by EUS. EUS - FNA was performed simultaneously in the 11 patients, and in 4 patients the diagnosis of metastasis was established. The accuracy for the diagnosis of adrenal metastasis was 100 % for EUS/EUS - FNA, 96.0 % for CT, and 97.0 % for PET-CT (P = 0.1146).

CONCLUSIONS

As well as the left adrenal gland, the right adrenal gland was also usually visible by EUS. EUS/EUS - FNA provided an accurate diagnosis of adrenal metastasis, although the prevalence of adrenal metastasis was relatively low in these patients with potentially resectable lung cancer.

The rubble-pile asteroid Itokawa as observed by Hayabusa

During the interval from September through early December 2005, the Hayabusa spacecraft was in close proximity to near-Earth asteroid 25143 Itokawa, and a variety of data were taken on its shape, mass, and surface topography as well as its mineralogic and elemental abundances. The asteroid's orthogonal axes are 535, 294, and 209 meters, the mass is 3.51 x 10(10) kilograms, and the estimated bulk density is 1.9 +/- 0.13 grams per cubic centimeter. The correspondence between the smooth areas on the surface (Muses Sea and Sagamihara) and the gravitationally low regions suggests mass movement and an effective resurfacing process by impact jolting. Itokawa is considered to be a rubble-pile body because of its low bulk density, high porosity, boulder-rich appearance, and shape. The existence of very large boulders and pillars suggests an early collisional breakup of a preexisting parent asteroid followed by a re-agglomeration into a rubble-pile object.

Touchdown of the Hayabusa Spacecraft at the Muses Sea on Itokawa

After global observations of asteroid 25143 Itokawa by the Hayabusa spacecraft, we selected the smooth terrain of the Muses Sea for two touchdowns carried out on 19 and 25 November 2005 UTC for the first asteroid sample collection with an impact sampling mechanism. Here, we report initial findings about geological features, surface condition, regolith grain size, compositional variation, and constraints on the physical properties of this site by using both scientific and housekeeping data during the descent sequence of the first touchdown. Close-up images revealed the first touchdown site as a regolith field densely filled with size-sorted, millimeter- to centimeter-sized grains.

Knock-in of nuclear localised beta-galactosidase reveals that the tyrosine phosphatase Ptprv is specifically expressed in cells of the bone collar

Ptprv is a member of the transmembrane tyrosine phosphatase gene family reported to be expressed in osteoblasts and gonads. To better define the developmental and tissue specificity of Ptprv expression, we generated knock-in mice expressing a nuclear localised beta-galactosidase reporter under the control of resident Ptprv regulatory elements. Histochemical staining of Ptprv-nLacZ mice revealed that Ptprv expression is readily detectable in the foetal gonadal ridge of both sexes and in adult gonads where it is localised to Sertoli cells of the testis and celomic epithelial cells of the ovaries. During early limb development, Ptprv expression is prominent in the apical ectodermal ridge of the limb bud. At latter stages of development, Ptprv is predominantly expressed in the perichondrial and periosteal region of long bones, known as the bone collar. In contrast to previous indications from in vitro studies, there is little if any expression in mature osteoblasts in vivo. Analysis of Ptprv mRNA localisation by in situ hybridization in parallel with molecular markers of chondrocytes and osteoblasts confirmed the specific expression of Ptprv in immature bone collar cells. The specificity of Ptprv expression in these cells may be a useful tool to elucidate their role in the transition of skeletal elements from cartilage template to bone.

Analysis of sequential immunoglobulin E-binding epitope of Japanese cedar pollen allergen (Cry j 2) in humans, monkeys and mice

BACKGROUND

Japanese cedar (Cryptomeria japonica; CJ) pollinosis has been reported to occur naturally in Japanese monkeys (Macaca fuscata) as well as in humans. Most human patients and monkeys with pollinosis have specific IgE for Cry j 2, a major allergen of CJ pollen.

OBJECTIVE

The main purpose of this study was to identify IgE B cell epitopes of Cry j 2 using a synthetic peptide in humans, monkeys and mice.

METHODS

We synthesized 38 overlapping peptides that span the entire length of Cry j 2. We examined the B cell epitopes of Cry j 2 that are recognized by IgE in the sera of human patients and monkeys with pollinosis and immunized mice using synthetic peptides of Cry j 2. We also examined the reaction of Cry j 2-specific mouse monoclonal IgG antibodies to the peptides. Furthermore, we conducted a histamine release assay with leucocytes from a pollinosis patient using human serum albumin (HSA) conjugated with the peptides as a B cell epitope.

RESULTS

We found that 16 of the 20 pollinosis patients who had specific IgE to Cry j 2 also exhibited IgE reaction with some Cry j 2 peptides. Of these 16 patients, 10 exhibited IgE reaction with Cry j 2 peptide no. 13 (121GQCKWVNGREICNDRDRPTA140). Five of the seven monkeys with CJ pollinosis exhibited a reaction with peptide no. 13. Furthermore, IgE in mice immunized with Cry j 2 and two mouse monoclonal IgG antibodies reacted with peptide no. 13. Peptide no. 13-conjugated HSA showed the release of histamine from basophils. Furthermore, to determine the minimum epitope in peptide no. 13, we conducted an enzyme-linked immunosorbent assay inhibition test. The core of the epitope in humans, monkeys and mice was 124KWVNGREI131.

CONCLUSION

We found that 124KWVNGREI131 is an important B cell epitope recognized by IgE in humans, monkeys and mice.

Preclinical evaluation of an immunotherapeutic peptide comprising 7 T-cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen allergens

BACKGROUND

Peptide immunotherapy is a new approach to treating allergic diseases, but a therapeutic peptide for Japanese cedar pollinosis has not yet been developed.

OBJECTIVE

The aim of this study is to prepare and preclinically evaluate a hybrid peptide comprising 7 T-cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen allergens.

METHODS

The recombinant hybrid peptide was prepared after immunodominance of 7 T-cell determinants was confirmed by means of PBMC proliferation assay in 113 volunteers with pollinosis. The hybrid peptide was compared with a mixture of the 7 T-cell determinants in a dose-dependent PBMC proliferation assay in 6 volunteers with pollinosis. PBMC proliferation and binding activity of serum IgE antibody against the hybrid peptide, Cry j 1, and Cry j 2 were investigated in 48 volunteers with pollinosis.

RESULTS

The hybrid peptide induced T-cell proliferation with an average 100-fold lower concentration than a mixture of the 7 peptides. PBMCs from 44 (92%) of 48 volunteers proliferated against the hybrid peptide, with significant correlation (r = 0.87) in T-cell proliferation against Cry j 1 and Cry j 2. No serum IgE antibodies specific to Cry j 1 or Cry j 2 bound to the hybrid peptide.

CONCLUSION

A hybrid peptide comprising 7 T-cell determinants has the potential for inducing T-cell proliferative responses that is superior to the potential of a mixture of the T-cell determinants and comparable with that of Cry j 1 and Cry j 2. The hybrid peptide will be of use in specific immunotherapy against Japanese cedar pollinosis.

Targeted disruption of cadherin-11 leads to a reduction in bone density in calvaria and long bone metaphyses

The migration and adhesion of osteoblasts requires several classical cadherins. Cadherin-11, one of the classical cadherins, was expressed in mouse osteoblasts in skull bone and femur, revealed by immunohistochemistry. To elucidate the function of cadherin-11 in osteoblastogenesis, cadherin-11 null mutant mice were investigated. Although apparently normal at birth, Alizarin red staining of null mutant mice showed a reduced calcified area at the frontal suture that caused a round-shaped calvaria with increasing animal age to 3 months. Consequently, there was a reduction in bone density at the femoral metaphyses and the diploë of calvaria in null mutant mice. In the in vitro culture of newborn calvarial cells, the calcified area of mutant cells was smaller than those derived from wild-type littermates. These results show that absence of cadherin-11 leads to reduced bone density in some parts of skeletons including calvaria and long bone metaphyses, and thus suggest that cadherin-11 plays roles in the regulation of osteoblast differentiation and in the mineralization of the osteoid matrix.

Characteristics of proper names and temporal memory of social news events

Long-term memory of social news events was investigated by means of a questionnaire methodology with a large sample of participants. In Experiment 1, a total of 501 university students were asked to give proper names (i.e., persons and places) that related to a certain news event, and to estimate the date of the event. The accuracy of proper names (especially person names) was superior to that of estimated date (i.e., year). In addition, telescoping effects were found in the events that occurred more than 3 years ago, but time expansion effects emerged in the events that occurred less than 2 years ago. In Experiment 2, in which 182 students participated, the accuracy of proper names and the date estimates tended to be high on the events that participants judged to be given frequent exposure by the mass media. Based on these results, we discuss long-term memory and temporal schemata regarding social news events.

Thermostabilization of a chimeric enzyme by residue substitutions: four amino acid residues in loop regions are responsible for the thermostability of Thermus thermophilus isopropylmalate dehydrogenase

A chimeric 3-isopropylmalate dehydrogenase, named 2T2M6T, made of parts from an extreme thermophile, Thermus thermophilus, and a mesophile, Bacillus subtilis, was found to be considerably more labile than the T. thermophilus wild-type isopropylmalate dehydrogenase. In order to identify the molecular basis of the thermal stability of the T. thermophilus isopropylmalate dehydrogenase, 11 amino acid residues in the mesophilic portion of the chimera were substituted by the corresponding residues of the T. thermophilus enzyme, and the effects of the side chain substitutions were analyzed by comparing the reaction rate of irreversible heat denaturation and catalytic parameters of the mutant chimeras with those of the original chimera, 2T2M6T. Four single-site mutants were successfully stabilized without any loss of the catalytic function. All these four sites are located in loop regions of the enzyme. Our results strongly suggest the importance of these loop structures to the extreme stability of the T. thermophilus isopropylmalate dehydrogenase.

The transition of cadherin expression in osteoblast differentiation from mesenchymal cells: consistent expression of cadherin-11 in osteoblast lineage

Osteoblasts are derived originally from pluripotent mesenchymal stem cells on migration into the bone matrix. To elucidate the contribution of classical cadherins in this differentiation pathway, we developed a new protocol for their analysis and studied their specific expressions in various cell lines of the mesenchymal lineage, including osteoblasts. N-cadherin was expressed constitutively in all cell lines examined except an osteocyte-like cell line whereas cadherin-11 was expressed selectively in preosteoblast and preadipocyte cell lines. P-cadherin also was expressed in primary cultures of calvarial cells and mature osteoblasts at a relatively low level compared with N-cadherin and cadherin-11. M-cadherin was expressed only in a premyoblast cell line. We observed the transition of cadherin expression from M-cadherin to cadherin-11 in the premyoblast cell line when osteogenic differentiation was induced by treatment with bone morphogenetic protein 2 (BMP-2), while the expression of N-cadherin remained unchanged. In contrast, when a preadipocyte cell line, which shows a similar pattern of cadherin expression to osteoblasts, was induced to undergo adipogenic differentiation, the expression of N-cadherin and cadherin-11 was decreased. These observations characterize the cadherin expression profile of mesenchymal lineage cells, especially osteoblasts, which regularly express cadherin-11. Cadherin-11 may affect cell sorting, alignment, and separation through differentiation.

Identification of a sequential B-cell epitope on major allergen (Cry j 1) of Japanese cedar (Cryptomeria japonica) pollen in mice

BACKGROUND

Japanese cedar (Cryptomeria japonica; CJ) pollinosis is one of the most common allergic diseases in Japan. B cell epitopes on Cry j 1, a major allergen of CJ pollen, have been analyzed by the specific monoclonal antibodies to Cry j 1, and most of these epitopes may be conformational, but no previous report has addressed the analysis of sequential epitope mapping with synthetic peptides. The main purpose of the present study is to identify IgE and IgG B cell epitopes on Cry j 1 by using a synthetic peptide approach in mice.

METHODS

We synthesized 35 overlapping peptides that cover the entire length of Cry j 1 and examined whether mouse IgE and IgG antibodies produced by immunization with Cry j 1 reacted to the Cry j 1 peptides.

RESULTS AND CONCLUSION

We found that mouse IgE and IgG antibodies reacted strongly to Cry j 1 peptide No. 15 ((141)GVEPVHPQDGDALTLRTATN(160)), though those antibodies did not react with other peptides. IgE and IgG antibody binding to peptide No. 15 was completely inhibited by Cry j 1 and the peptide. To determine the minimum epitope in peptide No. 15, we conducted an ELISA inhibition test. IgE and IgG antibody binding to peptide No. 15 was inhibited by smaller peptides of this peptide. We found the core of the epitope to be (145)VHPQDGDA(152).

The initial step of the thermal unfolding of 3-isopropylmalate dehydrogenase detected by the temperature-jump Laue method

A temperature-jump (T-jump) time-resolved X-ray crystallographic technique using the Laue method was developed to detect small, localized structural changes of proteins in crystals exposed to a temperature increase induced by laser irradiation. In a chimeric protein between thermophilic and mesophilic 3-isopropylmalate dehydrogenases (2T2M6T), the initial structural change upon T-jump to a denaturing temperature (approximately 90 degrees C) was found to be localized at a region which includes a beta-turn and a loop located between the two domains of the enzyme. A mutant, 2T2M6T-E110P/S111G/S113E, having amino acid replacements in this beta-turn region with the corresponding residues of the thermophilic enzyme, showed greater stability than the original chimera (increase of T:(m) by approximately 10 degrees C) and no T-jump-induced structural change in this region was detected by our method. These results indicate that thermal unfolding of the original chimeric enzyme, 2T2M6T, is triggered in this beta-turn region.

[A temporal feature of memory for plans]

How do we remember future plans? In this study, three experiments were conducted to examine this issue. Thirty to forty different undergraduate or graduate students participated as subjects in each experiment. In Experiment 1, subjects were asked to memorize plans for a day, assuming that they were of tomorrow in the 'future' condition and that they were of yesterday in the 'past' condition. The result showed that plans for the morning and the evening were recalled better than plans for the daytime (the U-shape effect), only in the future condition. In Experiment 2, plans were presented without time, so that subjects could not use any specific schema associated with time. In this condition, the U-shape effect disappeared. In Experiment 3, subjects were required to memorize plans for two days, tomorrow and the day after tomorrow. The result showed the U-shape effect for each day, not for two consecutive days. These results lead to the conclusion that some 'temporal information' about a day may affect the memory for future plans.

Effect of patellar taping on knee kinetics of patients with patellofemoral pain syndrome

STUDY DESIGN

Single-group repeated measures examining patients with patellofemoral pain syndrome.

OBJECTIVE

To examine the effect of McConnell patellar taping on single-leg vertical jump height and knee extensor moment and power during a vertical jump and lateral step-up.

BACKGROUND

Patellar taping is used by clinicians in an attempt to maximize knee extensor function during sporting activities and rehabilitation of patients with patellofemoral pain syndrome. No studies have examined the effect of patellar taping on vertical jump height and knee extensor moment and power during a maximal vertical jump or lateral step-up.

METHODS AND MEASURES

Fourteen women (24.4 +/- 5.8 years) with unilateral patellofemoral pain performed a single-leg vertical jump and lateral step-up during 4 knee conditions: patellar tape, placebo tape, no tape, and the uninvolved knee. Maximal knee extensor moment, knee power, and vertical jump height were measured for each condition using a force platform and motion analysis system.

RESULTS

Analysis of variance and post hoc analyses revealed a main effect for knee condition. The patellar tape condition resulted in a greater knee extensor moment (1.57 +/- 0.32 N.m/kg) and power (3.47 +/- 0.67 W/kg) than did the no-tape (1.31 +/- 0.39 N.m/kg and 2.79 +/- 1.21 W/kg) and placebo tape (1.33 +/- 0.30 N.m/kg and 2.70 +/- 0.99 W/kg) conditions. Additional analyses showed that the vertical-jump height was significantly greater in the uninvolved lower extremity (25.69 +/- 2.66 cm) compared with the patellar tape (23.33 +/- 4.22 cm), placebo tape (23.08 +/- 4.20 cm), and no-tape (23.45 +/- 4.54 cm) conditions. The patellar tape condition did not show a different vertical jump height than the placebo or no-tape conditions.

CONCLUSIONS

These results suggest that patellar taping compared with no tape may improve the knee extensor moment and power during weight-bearing activities such as the lateral step-up exercise and the vertical jump.

Expression and function of the splice variant of the human cadherin-11 gene in subordination to intact cadherin-11

Cadherin-11, a member of the type II classic cadherin subfamily, differs from type I family molecules such as P-, E-, and N-cadherins. An isoform of the human cadherin-11 gene, termed the variant form, encodes a truncated protein with a different cytoplasmic domain. The resulting protein does not possess any part of the cytoplasmic domain common to other cadherins. In the present study, analysis of the genomic organization of the cadherin-11 gene revealed that an insertion of 179 bp in an intron generates an alternatively spliced form. The mRNA expression of the variant form of cadherin-11 was examined in normal tissues by reverse transcription-polymerase chain reaction and/or Northern blot analyses. The variant form was expressed in the heart, brain, placenta, lung, and bone, but not in the kidney, skeletal muscle, pancreas, and liver. Western blot analyses revealed that the variant form is expressed as an 85 kDa protein, and that an additional secreted form also exists as an 80 kDa protein originated from cleavage of the intact form. Gene transfer of the variant form into L cells demonstrated that it lacked the adhesion properties characteristic of the intact form of cadherin-11 but enhanced the activity of Ca2+-dependent adhesion of the intact form of cadherin-11. The variant was expressed on the surface together with the intact form and stabilized the interaction between the intact form and beta-catenin. These findings suggest that expression of the variant form of human cadherin-11 may regulate the intact cadherin-11-mediated adhesion and alter the morphogenetic processes during mesenchymal cell differentiation including osteoblasts.

Large-scale preparation of recombinant human calcitonin from a multimeric fusion protein produced in Escherichia coli

In order to develop a large-scale, high-yield production process for human calcitonin (hCT) in Escherichia coli, a stable expression plasmid was constructed and the expressed protein was modified for efficient cleavage by protease. Multiple copies of a synthetic gene encoding hCT-Leu-Arg, a substrate for C-terminal amidation by carboxypeptidase Y (CPY), were inserted into the stable expression plasmid. Using this plasmid, the expression of a multimeric fusion protein was induced by shifting the temperature from 34 to 38 degrees C. The multimeric fusion protein was accumulated as inclusion bodies. After the fermentation, the cells were harvested and disrupted by a homogenizer. The insoluble multimeric fusion protein was suspended in 6.6 M urea solution. At this time, however, the protein could not be solubilized and thus the efficiency of cleavage by protease was low. To solubilize the protein and protect Lys residues against digestion by trypsin, the protein was citraconilated with citraconic anhydride. Following S-sulfonation with Na2SO3-CuSO4, almost all the protein was solubilized. The solubilized, citraconilated, and S-sulfonated protein was digested with trypsin efficiently. By treatment with trypsin, the multimeric fusion protein was cleaved into monomers of citraconilated and S-sulfonated hCT-Leu-Arg (S-hCT-Leu-Arg). The subsequent decitraconilation was performed at low pH. S-hCT-Leu-Arg, isolated by preparative HPLC, was directly converted into S-hCT-HN2 by CPY without removal of the Arg residue. Finally, S-hCT-NH2 was desulfonated and converted into mature hCT. In this way, a large amount of recombinant mature hCT was obtained in a tank fermentation. To our knowledge, this is the first report of industrial-scale, human calcitonin production using a multimeric fusion protein expression system.

How thick are the paraffin-embedded tissue sections routinely prepared in laboratory? A morphometric study using a confocal laser scanning microscope

In order to evaluate the differences between cut and measured thicknesses of formalin-fixed, paraffin-embedded tissue sections, formalin-fixed, paraffin-embedded blocks of liver tissue were prepared from four male Wistar rats. The sections were cut at preselected thicknesses of 3, 6, 9, 12, 15 and 18 microns, and observed under confocal laser scanning microscopy. The maximum and minimum section thicknesses were measured using a vertically cut section image constructed by the software incorporated in the microscope. The surface of the section was not smooth but showed fine undulations in addition to a slight inclination. The mean and range of the section thicknesses measured were 4.3 +/- 1.3, 7.0 +/- 1.7, 9.8 +/- 2.1, 12.0 +/- 2.6, 14.1 +/- 3.0, and 17.7 +/- 3.8 microns for the preselected cut thicknesses of 3, 6, 9, 12, 15 and 18 microns. It is stressed that the evaluated parameters of the section (volume or surface densities) include standard errors of up to 10% caused by the differences between the cut and real thicknesses.

The crystal structure of thermostable mutants of chimeric 3-isopropylmalate dehydrogenase, 2T2M6T

A chimeric 3-isopropylmalate dehydrogenase (IPMDH), 2T2M6T, was produced by replacing the amino acid sequences of the Thermus thermophilus enzyme with those of the Bacillus subtilis enzyme from residues 75 to 113. Decreased thermostability of the chimeric enzyme was recovered by either evolutionary engineering (I93L) or site-directed mutagenesis (S82R). The 3-D structures of the mutants have been determined by X-ray diffraction at 2.1 A resolution. Although S82R was refined routinely, I93L required the preliminary rigid-body refinement of each domain. The R-factors were reduced to 0.18 for both mutants. Removal of the unfavorable torsion angle at isoleucine 93 may have made I93L more thermostable than 2T2M6T. In the case of S82R, the replaced arginine residue contributed to the extra hydrogen bond with water molecules. The large replaced residue decreased the entropy of the solvent, which may have caused the improvement in enzyme thermostability. Denaturation by heating may be interpreted from these structural results.

Transfer of autoimmune diabetes from diabetic NOD mice to NOD athymic nude mice: the roles of T cell subsets in the pathogenesis

The NOD mouse, which spontaneously develops insulitis and overt diabetes, is a model of autoimmune type I diabetes mellitus. To analyze of the roles of CD4+ and CD8+ T cells in the pathogenesis of this mouse, we have been doing a series of studies on the induction of insulitis and diabetes in NOD athymic nude mice by means of T cell transfer. To complement our previous study dealing with the induction of insulitis and cyclophosphamide-induced diabetes in recipients that had been reconstituted with each T cell subset derived from the nondiabetic mice, the present study was conducted to observe the transfer of spontaneous diabetes by injecting T cells harvested from diabetic mice. Any possible in vivo increase in the contaminating T cell subset was prevented by injecting the antibody homologous to it. Transfer of untreated or complement-treated splenic lymphocytes of diabetic mice containing both T cell subsets induced spontaneous diabetes 30 to 58 days after the cell transfer as well as insulitis, while spleen cells from nondiabetic mice rarely produced diabetes. On the other hand, transfer of either CD4+ cell-depleted or CD8+ cell-depleted splenic lymphocytes of diabetic mice did not cause diabetes at least up to 60 days after the cell transfer. Also, transfer of only the CD4+ T cell-depleted fraction did not cause insulitis. In contrast, transfer of only the CD8+ T cell-depleted fraction induced insulitis in all the recipients. However, insulitis was less potent in this group of mice than in the diabetic recipients given both subsets: only a low insulitis score was obtained and a number of beta-cells remained alive despite the insulitis in mice given the CD8+ T cell-depleted fraction, whereas islet damage was very severe and insulin-secreting beta-cells were no longer detected in the diabetic mice. Thus, the present results agree with the previous ones concerning transfer of diabetes, with the aid of cyclophosphamide treatment, by T cells of nondiabetic mouse origin. Consideration of our results together with earlier findings led to the conclusion that CD4+ T cells are primarily responsible for insulitis and that CD8+ T cells migrate into islets and are differentiated into mature killer cells against beta-cells with the aid of CD4+ T cells in both spontaneous and cyclophosphamide-induced diabetes.

Analysis of the roles of CD4+ and CD8+ T cells in autoimmune diabetes of NOD mice using transfer to NOD athymic nude mice

The NOD mouse, which spontaneously develops insulitis and overt diabetes, is a model of autoimmune type I diabetes mellitus. For the precise analysis of the roles of CD4+ and CD8+ T cells in the pathogenesis of this mouse, these subsets must be transferred into recipients that are completely free of T cells and pathological changes. We used athymic NOD nude mice, which congenitally lack mature T cells and are free of insulitis and hyperglycemia up to the age of 60 weeks, as recipients for this purpose. To the nude recipients we transferred either one of a highly purified CD4+ or CD8+ T cell subset derived from non-diabetic female NOD mice; any in vivo increase in the contaminating T cell subsets was prevented by injecting the antibody homologous to it. Most of the T cell-reconstituted recipients were treated with cyclophosphamide to promote the onset of overt diabetes. Transfer of the CD8+ T cell subset alone did not induce insulitis or hyperglycemia. In contrast, transfer of the CD4+ T cell subset alone produced insulitis, but not hyperglycemia, in all the recipients. However, the subsequent transfer of CD8+ T cells into CD4+ T cell-reconstituted recipients induced severe insulitis and hyperglycemia in almost all the recipients. In these diabetic recipients, we observed severe damage of the pancreatic islets and the infiltration of a large number of CD8+ T cells into the remaining islets; insulin-secreting beta cells were no longer detected. These results suggest that CD4+ T cells play a predominant role in the development of insulitis and that CD8+ T cells migrate into the islets and are subsequently, with the aid of CD4+ T cells, differentiated into killer cells which act against beta cells.

[Measurement of the feeling of knowing: norms of 216 general-information questions]

The purpose of this study is to provide the normalized list of questions for investigating the feeling of knowing. Normative data were collected on 216 general-information questions from a wide variety of topics, including history, sports, art, literature, and so on. Three hundred and sixty-three undergraduates made a one-word response to each question, or rated their feeling of knowing on a 7-point scale if they could not recall any responses. The results showed that the questions distributed over a wide range on a scale of difficulty. There were few incorrect responses to the questions. Feeling-of-knowing ratings were moderately correlated with the probabilities of correct answers. These findings suggested that the questions provided in this study would serve for the research on the feeling of knowing. It was also suggested that the use of easier questions should generate a strong feeling of knowing.

Prevalence of Listeria (spp.) in wild rats captured in the Kanto area of Japan

In the Kanto area a total of 245 wild rats were captured. All rats captured in Ikebukuro (110 rats) and 9 out of 41 rats in Yokohama were Rattus rattus, and all other 126 rats were Rattus norvegicus. In Kashima and Ikebukuro, listeria was isolated from 28 rats (77.8%) and 27 rats (24.5%), respectively, but in the other 4 areas listeria was isolated from 0-7% rats. Listeria monocytogenes was isolated from 12 rats (10.9%) captured in Ikebukuro and 2 rats in Kashima and Numazu. The frequent isolation of L. monocytogenes in buildings suggests the possibility of R. rattus as a reservoir of L. monocytogenes and the continual environmental contamination in buildings by L. monocytogenes.

Seroepidemiological survey of lymphocytic choriomeningitis virus in wild house mouse (Mus musculus) in Yokohama Port, Japan

From 1985 to 1989, a total of 129 mice was captured from 7 piers of Yokohama port. Of these, 9 (7.0%) were positive to lymphocytic choriomeningitis virus (LCMV) antigen in indirect fluorescence antibody test. Six out of 31 mice (19.4%) in 1985 and 3 out of 23 mice (13.0%) captured in 1986 were positive. All the mice (74) captured in 1988 and 1989 were negative. Although 7 out of 17 mice (41.2%) in Osanbashi-Shinko pier and 2 out of 23 (8.7%) in Honmoku pier were positive in 1985 and 1986, all mice captured in other piers were negative. This is the first report detecting LCMV antibody in wild house mice in Japan.

PT pretreatment inhibits 48/80-induced activation of Ca(+)-permeable channels in rat peritoneal mast cells

We recently reported that the secretagogue, compound 48/80, activated Ca2(+)-permeable channels of mast cells possibly via a second messenger [Kuno, Okada, and Shibata. Am. J. Physiol. 256 (Cell Physiol. 25): C560-C568, 1989]. The effects of pretreatment with pertussis toxin (PT) on compound 48/80 (48/80)-induced activation of the Ca2(+)-permeable channel have now been investigated by measuring Ca2+ signals of cell suspensions using the Ca2+ indicator fura-2 and by recording Ba2+ currents through the channel using the patch-clamp technique. In the presence of extracellular Ca2+, the fluorescence change was biphasic, with an immediate rise and a delayed peak at room temperature. The delayed peak, mainly due to Ca2+ entry through plasma membranes, was greatly reduced by pretreatment with PT. The quenching of the fluorescence by 48/80-induced Mn2+ influx was also decreased by PT, whereas the Ca2+ transients due to Ca2+ release from the intracellular stores apparently did not change. In patch-clamp recordings from cell-attached patches with pipettes containing isotonic Ba2+, the 48/80-induced Ba2+ currents were either suppressed or delayed in the PT-treated cells, under conditions where degranulation was absent. These results suggest that PT-sensitive GTP-binding protein is involved in activating the Ca2(+)-permeable channel in mast cells during stimulus-secretion coupling.

[The effects of conscious and subconscious processing of hostility- or friendliness-related words on the personality impression of others]

Four experiments were conducted to investigate how the prior processing of trait relevant information influenced upon the impression formation. Twenty university students participated in each experiment. First subjects performed a cognitive task in which they processed hostility (Exp. I, II) or friendliness (Exp. III, IV) related words, consciously (Exp. I, III) or subconsciously (Exp. II, IV). In another ostensibly unrelated task, subjects rated a stimulus person on several trait scales based on an ambiguous behavioral description, regarding to hostility (Exp. I, II) or friendliness (Exp. III, IV). It was shown that the more hostility words subjects processed either consciously or subconsciously, the more extreme and negative ratings they yielded. As for friendliness words, however, such effects were found only when they were subconsciously processed, not when they were consciously processed. It was argued that conscious processing was affected by positiveness or negativeness of trait words, but subconscious processing was not.

[Conscious levels of processing a preceding stimulus and priming effect]

This study was conducted to investigate how two different conditions of processing a prime would affect the lexical decision time of a target. One condition was called the conscious condition, where a prime was presented for 250 ms and a subject was instructed to expect any target from that prime. Another condition was the unconscious condition, where a prime was briefly exposed and followed by a pattern mask so that a subject could not identify it. The effect of an associative strength of prime-target relatedness was also investigated. The associative strength of prime-target relatedness in the related condition was relatively weak in Exp. I, and strong in Exp. II. In the conscious condition, facilitation and inhibition were found both in Exp. I and in Exp. II. On the other hand, in the unconscious condition, only inhibition was found in Exp. I, but only facilitation in Exp. II. These results suggest that automatic activation and attention system were both needed to account for priming effect.

[Semantic priming effect on the perception of a Kanji]

A priming experiment was conducted to investigate how semantic context affects the perception of a briefly exposed Kanji target. On each trial, a Kanji or a plus (neutral) was presented as the prime stimulus for 1 s. When the prime was a Kanji, subjects were required to imagine any compound word, the first letter of which was to be that prime. After a blank of 500 ms, a target Kanji was briefly exposed followed by a patterned mask and two response alternatives, one of which the subject was asked to choose. The duration of the target was so adjusted that each subject could respond correctly at approximately 75% level. The % choice response was higher when the prime and the target made up a compound word (related condition) and also matched to the imagined word (facilitation) than when not (neutral condition). When the prime and the target were unrelated, the performance was the worst (inhibition). In the related condition, however, responses were more accurate even when the prime-target pair did not match to the imagined compound word than in the unrelated condition. These results suggest that semantic priming effect occurs automatically regardless of whether the subject may expect the target or not.