Younger patients have a higher rate of recovery of taste function after middle ear surgery

BACKGROUND

Although the chorda tympani nerve (CTN) is frequently damaged during tympanoplasty, little attention has been given to the patients' symptoms and taste function.

OBJECTIVE

To investigate patients' symptoms and the functional recovery of taste after surgery using electrogustometry (EGM).

DESIGN

Prospective study.

PATIENTS

Analysis of 163 ears of 156 patients who underwent middle ear surgery from April 1997 through December 1999. There were 18 ears with noninflammatory diseases, 80 with chronic otitis media, and 65 with cholesteatoma. The patients' taste functions were examined 2 days before surgery and 2 weeks and 6 months after surgery.

MAIN OUTCOME MEASURES

The taste disturbance before and after middle ear surgery and the relationship between age and the recovery rate of CTN function.

RESULTS

Two weeks after surgery, the mean EGM threshold was elevated in all groups regardless of preservation or section of the CTN. Numbness in the tongue and taste disturbance were more frequently found in patients with preservation of CTN than in those with section of the CTN (P =.008 and P =.001, respectively). In patients with preservation of the CTN, 6 months after surgery, the recovery rate of EGM threshold was 83% in those aged 20 years or younger (P =.008 compared with the 2 older groups), 53% in the those aged 21 to 40 years, and 44% in those aged 41 to 60 years.

CONCLUSION

Age is an important factor for recovery of taste function after middle ear surgery, which is useful information when explaining complications to patients.

Generation of definitive hematopoietic stem cells from murine early yolk sac and paraaortic splanchnopleures by aorta-gonad-mesonephros region-derived stromal cells

There is controversy as to whether murine definitive hematopoiesis originates from yolk sac (YS) or the intraembryonic region. This study reports the generation of definitive hematopoietic stem cells (HSCs) from both early YS and intraembryonic paraaortic splanchnopleures (P-Sp) on AGM-S3 stromal cells derived from the aorta-gonad-mesonephros (AGM) region at 10.5 days post coitum (dpc). YS and P-Sp cells at 8.5 dpc generated no definitive hematopoiesis-derived colony-forming cells in cocultures with AGM-S3 cells, but spleen colony-forming cells and HSCs capable of reconstituting definitive hematopoiesis in adult mice simultaneously appeared on day 4 of coculture. Precursors for definitive HSCs were present in YS and P-Sp at 8.0 dpc, a time when YS and embryo were not connected by blood vessels. It is proposed that precursors with the potential to generate definitive HSCs appear independently in YS and intraembryonic P-Sp and that the P-Sp or AGM region affords the microenvironment that facilitates generation of definitive hematopoiesis from precursors.

Development of human lymphohematopoietic stem and progenitor cells defined by expression of CD34 and CD81

In this study, cord blood CD34(+) cells expressed CD81, a member of the transmembrane 4 superfamily, and were classified into 3 subpopulations on the basis of their expression levels: CD34(+)CD81(+), CD34(low)CD81(+), and CD34(+)CD81(high). The lymphohematopoietic activity of each subpopulation was then examined by using suspension and clonogenic cultures for hematopoietic potential, coculture with MS-5 cells for B-cell potential, organ cultures of thymus lobes from nonobese diabetic/severe combined immunodeficiency disease (NOD/SCID) fetal mice, coculture with stromal cells derived from NOD/SCID fetal-mouse liver tissue for natural killer (NK) cell and mast cell potentials, and xenotransplantation into NOD/SCID mice for long-term repopulating (LTR) ability. CD34(+)CD81(+) cells represented a heterogeneous population that had all the lymphohematopoietic activities, including NOD/SCID mouse-repopulating ability. CD34(low)CD81(+) cells were enriched in erythroid, megakaryocytic, and NK lineage potentials but had lost T-cell and B-cell potentials and LTR ability. The CD34(+)CD81(high) fraction was depleted of most lymphohematopoietic potentials except NK cell and mast cell potentials. Thus, along the differentiation cascade from CD34(+)CD81(+) lymphohematopoietic stem cells, an up-regulation of CD81 or a down-regulation of CD34 results in a change in lymphohematopoietic properties. CD81 may serve as a marker for defining developmental stages of lymphohematopoietic stem cells. (Blood. 2001;97:3755-3762)

Factors affecting survival after living-related liver transplantation

The purpose of this study was to determine the perioperative factors that influence patient and graft outcome in living-related liver transplantation (LRLT). Between April 1995 and October 1998, we performed a series of 46 LRLT procedures, including 11 adult cased, at our institute. Mean age and weight of the recipients were 12.0 +/- 2.3 years and 23.7 +/- 2.6 kg, respectively. Seven out of the 46 patients had renal failure and received hemodialysis therapy before and after LRLT or kidney transplantation. The recipients were divided into two groups: those who survived for 7-48 months after LRLT (group 1, n = 36), and those who died within 4 months after surgery (group 2, n = 10). Factors analyzed included recipient age and weight, graft/recipient body weight ratio (G/R ratio), emergent vs elective surgery, United Network for Organ Sharing (UNOS) status, presence of preoperative plasmapheresis (PEX) and renal failure, and so on. Recipients in group 1 compared with group 2 had less advanced liver disease (i. e., a lower rate of emergent surgery, 14% vs 50%, and fewer patients with UNOS status 1, 14% versus 70%; P < 0.05 and P < 0.001, respectively). Group 1 recipients also had a lower percentage of preoperative treatment with plasmapheresis (22% vs 70%, P < 0.01). However, neither the G/R ratio nor the presence of renal failure affected the patient survival rate. In conclusion, factors independently associated with reduced patient survival after LRLT include emergent surgery, Child-Pugh class, UNOS status 1, and preoperative plasmapheresis.

Dexamethasone enhances SOX9 expression in chondrocytes

SOX9 is a transcription factor that activates type II procollagen (Col2a1) gene expression during chondrocyte differentiation. Glucocorticoids are also known to promote chondrocyte differentiation via unknown molecular mechanisms. We therefore investigated the effects of a synthetic glucocorticoid, dexamethasone (DEX), on Sox9 gene expression in chondrocytes prepared from rib cartilage of newborn mice. Sox9 mRNA was expressed at high levels in these chondrocytes. Treatment with DEX enhanced Sox9 mRNA expression within 24 h and this effect was observed at least up to 48 h. The effect of DEX was dose dependent, starting at 0.1 nM and maximal at 10 nM. The half life of Sox9 mRNA was approximately 45 min in the presence or absence of DEX. Western blot analysis revealed that DEX also enhanced the levels of SOX9 protein expression. Treatment with DEX enhanced Col2a1 mRNA expression in these chondrocytes and furthermore, DEX enhanced the activity of Col2-CAT (chloramphenicol acetyltransferase) construct containing a 1.6 kb intron fragment where chondrocyte-specific Sry/Sox- consensus sequence is located. The enhancing effect of DEX was specific to SOX9, as DEX did not alter the levels of Sox6 mRNA expression. These data suggest that DEX promotes chondrocyte differentiation through enhancement of SOX9.

Vitamin D(3) enhances the expression of I-mfa, an inhibitor of the MyoD family, in osteoblasts

I-mfa (inhibitor of the MyoD family) is a transcription modulator that binds to and suppresses the transcriptional activity of MyoD family members. I-mfa transcripts are expressed in sclerotome, suggesting a role of I-mfa in skeletogenesis. The aim of this study was to examine the expression and regulation of I-mfa in osteoblasts. We found that I-mfa is expressed at a low level in an osteoblast-like cell line, MC3T3E1, and a pluripotent differentiation modulator, 1,25-dihydroxyvitamin D(3), specifically enhanced I-mfa mRNA expression. This effect was completely blocked by the presence of an RNA polymerase inhibitor, but not by a protein synthesis inhibitor, suggesting that 1,25-dihydroxyvitamin D(3) upregulates transcription of the I-mfa gene without requirement for new protein synthesis. Western blot analysis indicated that 1,25-dihydroxyvitamin D(3) increased the I-mfa protein levels severalfold in MC3T3E1 cells. I-mfa expression was also observed in primary mouse calvaria cells and ROS17/2.8 cells and 1,25-dihydroxyvitamin D(3) enhanced I-mfa expression in these cells. These data indicate that I-mfa is a novel transcriptional regulator gene expressed in osteoblasts and that its level is under the control of 1,25-dihydroxyvitamin D(3).

Prompt and durable hematopoietic reconstitution by unrelated cord blood transplantation in a child with Fanconi anemia

We describe here the case of an 8-year-old girl with Fanconi anemia (FA) whose hematopoiesis was successfully restored by unrelated umbilical cord blood (UCB) transplantation. The patient became resistant to androgen therapy, and developed intracranial hemorrhage and dyserythropoiesis. Her hematopoietic recovery after the transplantation was excellent and a complete chimerism has been durably maintained. UCB should be considered as a stem cell source for transplantation when a patient with FA does not have an HLA-identical unaffected sibling donor.

Analysis of microcystins in sediments using MMPB method

During the course of study on the detoxification of microcystins, the adsorption on sediments in the natural environment was investigated. Because it was very difficult to extract microcystins from sediments using conventional techniques, a physicochemical screening method, the MMPB (2-methyl-3-methoxy-4-phenylbutyric acid) method, including ozonolysis and mass spectrometric detection was developed. This method consisted of the following operations: lyophilized sediments were suspended in methanol and MMPB-d(3) as an internal standard was added to this suspension, which was cooled at -78 degrees C with vigorous stirring and then treated with a stream of ozone/oxygen. After centrifugation, an aliquot of the reaction solution was subjected to EI (electron ionization)-GC/MS analysis after methylation with 14% BF(3)-methanol and liquid-liquid extraction. The established method had a potential for the analysis of microcystins in sediments that are difficult to analyze using conventional methods. Finally, this method was applied to sediment samples collected in Japanese lakes and six of the eleven samples showed positive results. The obtained results clearly indicated that the adsorption on sediments contributes to the detoxification of microcystins under natural conditions.

Risk of alanine aminotransferase flare-up among asymptomatic hepatitis C virus RNA carriers: a 10-year follow-up study

AIMS

The aim of this study was to determine the cumulative rate of flare-up of serum alanine aminotransferase (ALT) level during a 10-year follow-up period, and characterize the clinical, virologic features in 120 hepatitis C virus (HCV) RNA-positive asymptomatic carriers with persistently normal ALT levels for 6 months.

RESULTS

All flare-up cases occurred during the first 5 years of the present study, 27.4% of carriers showed ALT flare-up during this period, but none in the second half of the study. Multivariate analysis showed that C100-3 antibody (Ab) and anti-human T cell leukemia virus (HTLV)-I Ab were two independent and significant predictors of ALT flare-up in hepatitis C virus (HCV) RNA asymptomatic carriers (P = 0.04, P = 0.03, respectively). Liver biopsy was performed in 44 patients (11 with flare-up of ALT level, whereas 33 had normal ALT levels). Histological features of chronic hepatitis with lymphoid infiltration in the portal tracts were commonly observed in all specimens, and no differences were noted between the flare-up ALT group and the persistently normal ALT group.

CONCLUSIONS

Our results indicated that flare-up of ALT levels in asymptomatic HCV-RNA carriers with normal ALT levels occurs during the first 5 years of diagnosis, and that the presence of C100-3 and anti-HTLV-I antibodies are good predictors of a transient rise in ALT.

Scratch cytologic findings on surgically resected solitary fibrous tumors of the pleura

OBJECTIVE

To ascertain the cytologic characteristics of solitary fibrous tumors of the pleura (SFTPs) on smear preparations.

STUDY DESIGN

Fine needle aspiration cytology (FNAC) was initially attempted preoperatively in five cases, but the specimens were inappropriate for interpretation because only a few tumor cells were obtained. Therefore, scratch smears made at the time of operation were used. Papanicolaou and immunocytochemical staining was performed in all 10 cases, 2 of which were malignant.

RESULTS

As expected, cellular tumors yielded more cells. The cytologic appearance was variable, showing spindle/bipolar, dendritic/stellate and intermediate cells. Atypical cells reminiscent of sarcoma were also present in cellular, benign tumors. Highly atypical epithelioid cells were obtained in two malignant cases. Immunocytochemically, the tumor cells were positive for CD34 and vimentin and negative for cytokeratin, regardless of histologic differences and cell shape.

CONCLUSION

It seems difficult to diagnose SFTPs with certainty by FNAC, partly because the cell morphology of SFTPs resembles a wide variety of heterogeneous groups of spindle cell tumors and partly because only a few tumor cells were available in the FNAC specimens in the present study. However, a cytologic diagnosis of SFTP is possible if cytologic preparations yield CD34-positive cells with spindle/bipolar or dendritic/stellate morphology.

Parathyroid hormone-induced bone resorption does not occur in the absence of osteopontin

Osteopontin is an RGDS-containing protein that acts as a ligand for the alpha(v)beta(3) integrin, which is abundantly expressed in osteoclasts, cells responsible for bone resorption in osteopenic diseases such as osteoporosis and hyperparathyroidism. However, the role of osteopontin in the process of bone resorption has not yet been fully understood. Therefore, we investigated the direct function of osteopontin in bone resorption using an organ culture system. The amount of (45)Ca released from the osteopontin-deficient bones was not significantly different from the basal release from wild type bones. However, in contrast to the parathyroid hormone (PTH) enhancement of the (45)Ca release from wild type bones, PTH had no effect on (45)Ca release from organ cultures of osteopontin-deficient bones. Because PTH is located upstream of receptor activator of NF-kappaB ligand (RANKL), that directly promotes bone resorption, we also examined the effect of RANKL. Soluble RANKL with macrophage-colony stimulating factor enhanced (45)Ca release from the bones of wild type fetal mice but not from the bones of osteopontin-deficient mice. To obtain insight into the cellular mechanism underlying the phenomena observed in osteopontin-deficient bone, we investigated the number of tartrate-resistant acid phosphatase (TRAP)-positive cells in the bones subjected to PTH treatment in cultures. The number of TRAP-positive cells was increased significantly by PTH in wild type bone; however, no such PTH-induced increase in TRAP-positive cells was observed in osteopontin-deficient bones. These results indicate that the absence of osteopontin suppressed PTH-induced increase in bone resorption via preventing the increase in the number of osteoclasts in the local milieu of bone.

Initial strength of highpressed extrusion poly-L-lactide screw

We developed a poly-L-lactide material strengthened by a highpressed extrusion technique. The bending strength of a rod made of that material is higher than that of the same size rods made of poly-L-lactide strengthened by drawing technique, which has been used in clinical cases. The purposes of this study were, first to clarify if the initial strength of extrusion-strengthened poly-L-lactide screws is higher than that of draw-strengthened poly-L-lactide screws, and, secondly to investigate the safe torque for driving the screws in clinical usage. In accordance with AO screw design, five kinds of screws were manufactured. In a pull-out test and a twisting test using a DYRACON blocks, the strength of the highpressed extrusion-strengthened poly-L-lactide material was also higher than that of the draw-strengthened poly-L-lactide material after milling into screws. In the simulation using minipig bones and the 4.5 mm psi cortical screws, when the thickness was below 0.5 mm, between 0.5 and 2 mm or over 3 mm, the break locations were in the cortical bone, the thread of the screw and the under head fillet respectively. In the simulation using minipig bones and the 4.0 mm psi cancellous screws, breakage occurred not on the screws but on the cancellous bone in all screws.

"Mitotic drive" of expanded CTG repeats in myotonic dystrophy type 1 (DM1)

In myotonic dystrophy type 1 (DM1), an expanded CTG repeat shows repeat size instability in somatic and germ line tissues with a strong bias toward further expansion. To investigate the mechanism of this expansion bias, 29 DM1 and six normal lymphoblastoid cell lines (LBCLs) were single-cell cloned from blood cells of 18 DM1 patients and six normal subjects. In all 29 cell lines, the expanded CTG repeat alleles gradually shifted toward further expansion by "step-wise" mutations. Of these 29 cell lines, eight yielded a rapidly proliferating mutant with a gain of large repeat size that became the major allele population, eventually replacing the progenitor allele population. By mixing cell lines with different repeat expansions, we found that cells with larger CTG repeat expansion had a growth advantage over those with smaller expansions in culture. This growth advantage was attributable to increased cell proliferation mediated by Erk1,2 activation, which is negatively regulated by p21(WAF1). This phenomenon, which we designated "mitotic drive" , is a novel mechanism which can explain the expansion bias of DM1 CTG repeat instability at the tissue level, on a basis independent of the DNA-based expansion models. The lifespans of the DM1 LBCLs were significantly shorter than normal cell lines. Thus, we propose a hypothesis that DM1 LBCLs drive themselves to extinction through a process related to increased proliferation.

Isolation of amantadine-resistant influenza a viruses (H3N2) from patients following administration of amantadine in Japan

In Japan, the use of amantadine for treatment of influenza A virus infection was not accepted until November 1998, although it was widely used for treatment of Parkinsonism. Since then, we have monitored the emergence of amantadine-resistant viruses and isolated two viruses from patients on long-term treatment with amantadine.

Panic disorder cases in Japanese-Brazilians in Japan: their ethnic and cultural confusion

The comparatively high salaries made in Japan are attractive to many Japanese-Brazilians. The number of individuals from this ethnic group being treated in Japanese mental hospitals has increased. We hypothesized that Japanese-Brazilian patients with panic disorders adjusted better to Japanese society and culture than those with other mental disorders. The subjects in the present study are 40 Japanese-Brazilian patients undergoing treatment at the Department of Psychiatry at Jichi Medical School, Japan, from May 1990 to September 1998. Patients were divided into a panic disorder group, a schizophrenic group, a mood disorder group and a neurosis group. Demographic data (Japanese language ability, duration of residence in Japan etc.) were collected. A comparison was made among the four groups. Patients in the panic disorder group showed a significant tendency to be fluent speakers of Japanese. Patients in the panic disorder group also had been in Japan for a significantly longer period of time than those in the other three groups. Japanese ability and length of residence in Japan rule out exacerbating factors due to a foreign living environment. Panic disorder patients usually have resolved the problems inherent in living and working in a foreign country. In general, Japanese-Brazilians are more comfortable both financially and socially in Japan than other foreign laborers because of their cultural and family background. The emotional conflict experienced by such patients may result from concern over whether to live in Brazil or Japan in the future. Their ethnic and cultural identity may be confused, fluctuating between identifying with Brazil and with Japan, and this may cause vague feelings of anxiety.

Evidence for the presence of murine primitive megakaryocytopoiesis in the early yolk sac

During mouse embryogenesis, primitive erythropoiesis occurs in blood islands of the yolk sac (YS) on the seventh day of gestation. This study demonstrated for the first time the presence of unique primitive megakaryocytic (Mk) progenitors in the early YS, which disappeared by 13.5 days postcoitum (dpc). When 7.5 dpc YS cells were incubated in the presence of stem cell factor (SCF), interleukin (IL)-3, IL-6, erythropoietin (EPO), thrombopoietin (TPO), and granulocyte colony-stimulating factor in methylcellulose clonal culture, not only erythroid bursts but also megakaryocyte colonies were observed. The megakaryocytes in the colonies matured to proplatelet stages and produced platelets as early as day 3 of culture, much earlier than those from adult bone marrow, although their ploidy class was lower. These megakaryocytes were stained with acetylcholine esterase, and expressed platelet glycoprotein (GP)Ib beta, GPIIIa, and platelet factor 4 by reverse transcription-polymerase chain reaction analysis. The analysis of hemoglobin types in erythrocytes obtained from hematopoietic multilineage colonies containing the megakaryocytes indicated that the Mk progenitors originated from primitive hematopoiesis. The primitive Mk progenitors formed colonies in the absence of any cytokines in fetal bovine serum (FBS)-containing culture, and SCF, IL-3, EPO, and TPO significantly enhanced the Mk colony formation. In FBS-free culture, however, no colony formation was induced without these cytokines. Because megakaryocytes were detected in 8.5-dpc YS, these unique primitive Mk progenitors may rapidly mature and give rise to platelets to prevent hemorrhage in the simultaneously developing blood vessels until definitive hematopoiesis begins to produce platelets. (Blood. 2001;97:2016-2022)

Comparative study on reduction of bone loss and lipid metabolism abnormality in ovariectomized rats by soy isoflavones, daidzin, genistin, and glycitin

The effects of the soy isoflavone glycoside, daidzin, genistin, and glycitin on bone loss and lipid metabolism in ovariectomized (ovx) rats were compared with those of estrone. Thirty-six 11-week-old female Sprague-Dawley rats were assigned to six groups, sham-operated, ovx, ovx+glycitin, ovx+daidzin, ovx+genistin, and ovx+estrone and fed matched amounts of a commercial calcium-deficient diet for 4 weeks. Throughout this period, daidzin, genistin or glycitin (25, 50 or 100 mg/kg/d) was given orally using a stomach tube, or estrone (7.5 microg/kg/d) was administered subcutaneously. Daidzin, genistin and glycitin significantly prevented bone loss in ovx rats at a dose of 50 mg/kg/d, like estrone. At this dose glycitin and daidzin also prevented ovx-induced uterine atrophy and increases in body weight gain, abdominal fat, serum total cholesterol and triglyceride, and urinary excretion of pyridinoline and deoxypyridinoline with statistical significance, like estrone. On the other hand, genistin prevented ovx-induced uterine atrophy only at a dose of 100 mg/kg, but did not block any other change of ovx rats at a dose of 50 or 100 mg/kg. These findings indicate that daidzin, glycitin, and genistin are effective in preventing bone loss and the former two compounds are effective in reversing the unfavorable changes of lipid metabolism in this model. It is suggested that the preventive effect of daidzin or glycitin on bone loss in ovx rats is due to suppression of bone turnover, as in the case of estrone, but genistin has a different mechanism of action from the other compounds. Soy isoflavone glycosides may represent a potential alternative therapy in the treatment of bone loss and lipid metabolism abnormality in ovarian hormone-deficient women.

Osteopontin deficiency reduces experimental tumor cell metastasis to bone and soft tissues

Osteopontin has been implicated in the metastasis of tumors, and human tumors with high metastatic activity often express osteopontin at high levels. Osteopontin contains an arginine-glycine-aspartate (RGD) motif that is recognized by integrin family members to promote various cell activities including attachment to substrate and it is abundant in bone, to which certain tumors preferentially metastasize. Therefore, we investigated the role of osteopontin in the experimental metastasis of tumor cells using recently established osteopontin-deficient mice. B16 melanoma cells, which produce little osteopontin, were injected into the left ventricle of osteopontin-deficient mice or wild-type mice. Animals were killed 2 weeks after injection. The number of tumors was reduced in the bones of osteopontin-deficient mice compared with the bones in wild-type mice. The number of tumors in the adrenal gland also was reduced. To investigate the osteopontin effect on metastases via a different route, we injected B16 melanoma cells into the femoral vein. Through this route, the number of lung tumors formed was higher than in the intracardiac route and was again less in osteopontin-deficient mice compared with wild-type mice. In conclusion, in an experimental metastasis assay, the number of tumors found in bone (after intracardiac injection) and lung (after left femoral vein injection) was significantly reduced in osteopontin-deficient mice compared with wild-type mice. Tumor numbers in other organs examined were small and not significantly different in the two situations.

Effect of facial affect stimuli on auditory and visual P300 in healthy subjects

This study investigated whether or not P300 components are influenced by emotional affect such as sadness and pleasure in twenty healthy subjects and whether or not the P300 effects of facial affect stimuli are influenced by auditory and visual stimulus modalities. Written informed consent was taken from each subject before the study. Each subject was asked to stare at a simple picture of a facial expression (crying or smiling faces) during the auditory and visual oddball tasks. P300 amplitude and area were significantly larger when viewing a crying face (sadness) than a smiling face (pleasure) under both conditions with auditory and visual stimulus. P300 latency was significantly longer while viewing sadness than while viewing pleasure only with auditory stimuli. Reaction time was not changed by facial stimuli. Amplitude and area of P300 were significantly larger in women than men in their modalities, but the effects of facial affect on P300 amplitude and area in women were similar to those in men. These results suggest that amplitude and area of P300 with both modalities recorded while viewing sadness may induce larger attentional resource than pleasure. Gender was a less potent influence of facial expression on P300 parameters. The influence of facial emotion may be important to investigate the recognition processes of subjects.

Osteopontin facilitates angiogenesis, accumulation of osteoclasts, and resorption in ectopic bone

Osteoclastic bone resorption requires a number of complex steps that are under the control of local regulatory molecules. Osteopontin is expressed in osteoclasts and is also present in bone matrix; however, its biological function has not been fully understood. To elucidate the role of osteopontin in the process of osteoclastic bone resorption, we conducted ectopic bone implantation experiments using wild-type and osteopontin knockout mouse. In the wild-type group, bone discs from calvariae implanted ectopically in muscle were resorbed, and their mass was reduced by 25% within 4 weeks. In contrast, the mass of the bone discs from calvariae of osteopontin knockout mice was reduced by only 5% when implanted in osteopontin knockout mice. Histological analyses indicated that the number of osteoclasts associated with the implanted bones was reduced in the osteopontin knockout mice. As osteopontin deficiency does not suppress osteoclastogenesis per se, we further examined vascularization immunohistologically and found that the number of vessels containing CD31-positive endothelial cells around the bone discs implanted in muscle was reduced in the osteopontin knockout mice. Furthermore, sc implantation assays indicated that the length and branching points of the newly formed vasculatures associated with the bone discs were also reduced in the absence of osteopontin. In this assay, tartrate-resistant acid phosphatase-positive area of the bone discs was also reduced in the osteopontin knockout mice, indicating further the link between the osteopontin-dependent vascularization and osteoclast accumulation. The bone resorption defect could be rescued by topical administration of recombinant osteopontin to the bones implanted in muscle. These observations indicate that osteopontin is required for efficient vascularization by the hemangiogenic endothelial cells and subsequent osteoclastic resorption of bones.

XAFS study on the sulfidation mechanisms of Co-Mo catalysts supported on activated carbon and alumina: effect of complexing agent

The effect of nitrilotriacetic acid (NTA) as a complexing agent on the sulfidation mechanisms of Co-Mo catalysts supported on activated carbon and alumina was examined by the XAFS technique. The XAFS results revealed that NTA interacted with Co atoms and formed the Co-NTA interaction, while it showed almost no influence on the local structures around Mo atoms. The Co-NTA interaction suppressed the aggregation of cobalt atoms and the interaction between cobalt and alumina during sulfiding, and consequently promoted the formation of the Co-Mo-S phase.

Microencapsulation of pesticides and their improved handling safety

The purpose of pesticide formulations and recent requirements of pesticide industry are discussed, and the importance of research work on pesticide delivery systems, is pointed out. For this purpose, the microcapsules, as one of the typical controlled release formulations, play an important role. Handling safety of the pesticides is improved considerably by microencapsulation due to hazard and exposure reduction.

Characterization and subcellular localization of KCNQ1 with a heterozygous mutation in the C terminus

Numerous mutations in KCNQ1, a gene encoding the alpha -subunit of cardiac delayed rectifier potassium channels, have been found in long QT syndrome (LQTS). Among them, several mutations in the C terminus have been shown to cause autosomal recessive or subclinical autosomal dominant LQTS. Here, we report a heterozygous mutation, T587M, which is also in the KCNQ1 C-terminal domain. The same mutation was found in three independent probands that were clearly symptomatic with family history of cardiac sudden death. Functional assay using a heterologous expression system with a mammalian cell line (COS7 cells) revealed that the mutant displayed neither functional channels when expressed alone nor dominant-negative effect when co-expressed with wild-type (WT) KCNQ1. To examine the cellular trafficking of KCNQ1, green fluorescent protein (GFP) was tagged to the cytoplasmic C terminus of WT or mutant KCNQ1. This procedure did not affect the essential properties of expressed WT KCNQ1 channels. On confocal microscopic images, GFP-tagged WT KCNQ1 showed a plasma membrane fluorescence pattern, whereas the GFP-tagged mutant showed a perinuclear fluorescence pattern. Co-expression of the mutant with GFP-tagged WT KCNQ1 did not influence its normal cellular transport. Therefore, the T587M mutant cannot traffic to the plasma membrane and may form no subunit assembly with WT KCNQ1. These findings provide a novel molecular basis for the clinical finding that this C-terminal mutation produced a severe form of RWS-type LQTS.