Amphos-Mediated Conversion of Alkyl Azides to Diazo Compounds and One-Pot Azide-Site Selective Transient Protection, Click Conjugation, and Deprotective Transformation

A one-pot conversion of alkyl azides to diazo compounds is outlined. After the reaction of α-azidocarbonyl compounds with Amphos, treatment of the resulting phosphazides with silica gel in a wet solvent afforded α-diazo carbonyl products. Through the azido group protection property of Amphos, inter- and intramolecular azide-site selective reactions of azido group protection, click functionalization, and deprotection of the diazo group have been demonstrated in one pot.

Pore opening, not voltage sensor movement, underpins the voltage-dependence of facilitation by a hERG blocker

A drug that blocks the cardiac myocyte voltage-gated K+ channels encoded by the human Ether-à-go-go-Related Gene (hERG) carries a potential risk of long QT syndrome and life-threatening cardiac arrhythmia, including Torsade de Points Interestingly, certain hERG blockers can also facilitate hERG activation to increase hERG currents, which may reduce proarrhythmic potential. However, the molecular mechanism involved in the facilitation effect of hERG blockers remains unclear. The hallmark feature of the facilitation effect by hERG blockers is that a depolarizing preconditioning pulse shifts voltage-dependence of hERG activation to more negative voltages. Here we utilize a D540K hERG mutant to study the mechanism of the facilitation effect. D540K hERG is activated by not only depolarization but also hyperpolarization. This unusual gating property enables tests of the mechanism by which voltage induces facilitation of hERG by blockers. With D540K hERG, we find that nifekalant, a hERG blocker and Class III antiarrhythmic agent, blocks and facilitates not only current activation by depolarization but also current activation by hyperpolarization, suggesting a shared gating process upon depolarization and hyperpolarization. Moreover, in response to hyperpolarizing conditioning pulses, nifekalant facilitates D540K hERG currents but not wild-type currents. Our results indicate that induction of facilitation is coupled to pore opening, not voltage per se We propose that gated access to the hERG central cavity underlies the voltage-dependence of induction of facilitation. This study identifies hERG channel pore gate opening as the conformational change facilitated by nifekalant, a clinically important antiarrhythmic agent. Significance Statement Nifekalant is a clinically important antiarrhythmic agent and a hERG blocker which can also facilitate voltage-dependent activation of hERG channels after a preconditioning pulse. Here we show that the mechanism of action of the preconditioning pulse is to open a conductance gate to enable drug access to a facilitation site. Moreover, we find that facilitation increases hERG currents by altering pore dynamics, rather than acting through voltage sensors.

Supramolecular linear coordination polymers of human serum albumin and haemoglobin

We describe the synthesis, structure, and functionalities of water-soluble linear coordination polymers of human serum albumin and haemoglobin, which are connected via a bis(terpyridyl)-Fe²⁺ complex. These protein fibres were self-assembled by lyophilisation and were transformed into single-wall nanotubes. The biological activities of the protein units were perfectly preserved in the long fibres.

Neural substrates of social facilitation effects on incentive-based performance

Throughout our lives we must perform tasks while being observed by others. Previous studies have shown that the presence of an audience can cause increases in an individual’s performance as compared to when they are not being observed—a phenomenon called ‘social facilitation’. However, the neural mechanisms underlying this effect, in the context of skilled-task performance for monetary incentives, are not well understood. We used functional magnetic resonance imaging to monitor brain activity while healthy human participants performed a skilled-task during conditions in which they were paid based on their performance and observed and not observed by an audience. We found that during social facilitation, social signals represented in the dorsomedial prefrontal cortex (dmPFC) enhanced reward value computations in ventromedial prefrontal cortex (vmPFC). We also found that functional connectivity between dmPFC and ventral striatum was enhanced when participants exhibited social facilitation effects, indicative of a means by which social signals serve to modulate brain regions involved in regulating behavioral motivation. These findings illustrate how neural processing of social judgments gives rise to the enhanced motivational state that results in social facilitation of incentive-based performance.

Good appearance of food gives an appetizing impression and increases cerebral blood flow of frontal pole in healthy subjects

We investigated the effect of food appearance on appetite and on left-frontal pole blood flow in healthy young subjects. The iEat, a new form of foods with good appearance and greater softness was hypothesized to have the better effects to the subjects than blender-processed foods. The effect on appetite and left-frontal pole blood flow using hemoencephalography was assessed while participants were viewing the slideshows of two kinds of foods respectively. The slideshows were used to control the showing time and other variables. The pictures of iEat foods stimulated both of them more than the blender-processed ones. The measurement of cerebral blood flow could be a useful method to monitor the cognitive and emotional aspects of feeding behavior that are important for humans. Like iEat, the foods that look as good as ordinary food yet are softer can be used for people with poor appetite and eating difficulties to ordinary food.

Neural mechanisms underlying human consensus decision-making

Consensus building in a group is a hallmark of animal societies, yet little is known about its underlying computational and neural mechanisms. Here, we applied a computational framework to behavioral and fMRI data from human participants performing a consensus decision-making task with up to five other participants. We found that participants reached consensus decisions through integrating their own preferences with information about the majority group members' prior choices, as well as inferences about how much each option was stuck to by the other people. These distinct decision variables were separately encoded in distinct brain areas-the ventromedial prefrontal cortex, posterior superior temporal sulcus/temporoparietal junction, and intraparietal sulcus-and were integrated in the dorsal anterior cingulate cortex. Our findings provide support for a theoretical account in which collective decisions are made through integrating multiple types of inference about oneself, others, and environments, processed in distinct brain modules.

Sensitization to acid-hydrolyzed wheat protein by transdermal administration to BALB/c mice, and comparison with gluten

BACKGROUND

An increasing number of studies have shown that hydrolyzed wheat protein (HWP) can induce IgE-mediated hypersensitivity by skin contact and/or food ingestion. However, there has been no study of the sensitizing potential of HWP. In this study, the possibility of transdermal pathway for sensitization to acid-HWP (HWP1) was investigated using BALB/c mice, and compared with that of gluten.

METHODS

HWP1 or gluten (500 μg/mouse) was transdermally administered using patches. After three or four cycles of sensitization for 3 days/week, active systemic anaphylaxis (ASA) was induced by intraperitoneal injection of the antigen, and rectal temperatures, scores of anaphylactic responses, and plasma histamine levels were determined. Because HWP1 was included in facial soap in Japan, the effect of detergent on the sensitizing potential was also investigated.

RESULTS

Transdermal administration of HWP1 induced dose-dependent production of IgE and IgG1. After sensitization for 3 or 4 weeks, intraperitoneal injection of HWP1 caused ASA, leading to decreased rectal temperatures, increased anaphylaxis scores, and increased plasma histamine levels. In addition, splenocytes harvested after ASA produced IL-4, IL-5, and IL-10 by re-stimulation with HWP1. Transdermal exposure to gluten also induced IgE and IgG1 production, and intraperitoneal injection of gluten also induced ASA only in mice sensitized in the presence of sodium dodecyl sulfate.

CONCLUSIONS

Transdermal exposure to HWP1 is sufficient to activate key immune pathways necessary for sensitizing mice for immediate hypersensitivity reactions. This study shows that HWP has a sensitizing potential as well as gluten, whereas its allergenicity may be different from that of gluten.

Description of International Caenorhabditis elegans Experiment first flight (ICE-FIRST)

Traveling, living and working in space is now a reality. The number of people and length of time in space is increasing. With new horizons for exploration it becomes more important to fully understand and provide countermeasures to the effects of the space environment on the human body. In addition, space provides a unique laboratory to study how life and physiologic functions adapt from the cellular level to that of the entire organism. Caenorhabditis elegans is a genetic model organism used to study physiology on Earth. Here we provide a description of the rationale, design, methods, and space culture validation of the ICE-FIRST payload, which engaged C. elegans researchers from four nations. Here we also show C. elegans growth and development proceeds essentially normally in a chemically defined liquid medium on board the International Space Station (10.9 day round trip). By setting flight constraints first and bringing together established C. elegans researchers second, we were able to use minimal stowage space to successfully return a total of 53 independent samples, each containing more than a hundred individual animals, to investigators within one year of experiment concept. We believe that in the future, bringing together individuals with knowledge of flight experiment operations, flight hardware, space biology, and genetic model organisms should yield similarly successful payloads.

Genetic analysis of ryanodine receptor function in Caenorhabditis elegans based on unc-68 revertants

The Caenorhabditis elegans ryanodine receptor is encoded by the unc-68 gene, and functions as a Ca2+-induced Ca2+ release channel during muscle contraction. To investigate the factors that suppress calcium release and identify molecules that interact with the ryanodine receptor, we isolated revertants from two unc-68 mutants. Three of the revertants obtained from the null allele unc-68(e540), which displayed normal motility, had intragenic mutations that resulted in failure to splice out intron 21. The other two, kh53 and kh55, had amino acid insertions in the third of the four RyR domains. The brood size and the egg laying rate remain abnormal in these revertants. This suggests the third RyR domain may be required for egg laying and embryogenesis, although we can not determine a molecular mechanism. Five ketamine sensitive revertants recovered from the missense mutant unc-68(kh30) showed altered responses to caffeine, ryanodine, levamisole and ouabain relative to those of the unc-68(kh30) animals. These may carry second-site suppressor mutations, which may define genes for proteins that regulate the Ca2+ concentration in body-wall muscle. One of these mutants, kh52, shows lower motility and higher sensitivity to drugs, and this mutation was mapped to chromosome X. These observations provide a basis for the study of ryanodine receptor functions in embryogenesis and in calcium-mediated regulation of muscle contraction in C. elegans. This is the first study to show that the conserved RyR domain of the receptor acts in egg laying and embryogenesis.

[Multi-institutional cooperative study on combination chemotherapy with THP, CDDP and 5-FU for squamous cell carcinoma of the head and neck]

Combination chemotherapy with THP, CDDP and 5-FU for squamous cell carcinoma of the head and neck was conducted in 13 institutions in Hyogo Prefecture as a multi-institutional cooperative study. In the initial study (Nov. 1990-Nov. 1993), THP was administered intravenously at 20 mg/m2 on day 1, CDDP at 80 mg/m2 on day 2, and 5-FU at 1,000 mg/body/day in a continuous drip infusion for 120 hours from day 2 to day 6. In the second study (May, 1996-Mar. 1998), THP was administered at 20 mg/m2 on day 1, 5-FU at 10 mg/kg/day from day 1 to day 5, and CDDP at 70 mg/m2 on day 6 in the same way as the initial study. Forty-nine patients (Stage I in 3, Stage II in 12 including 2 recurrent cases, Stage III in 6, Stage IV in 28 including 3 recurrent cases; 1 course chemotherapy in 13 and 2 or more courses in 36) were subjected as complete cases in the initial study, and 36 patients (Stage I in 5 including one recurrent case, Stage II in 11 including 1 recurrent case, Stage III in 9 including 2 recurrent cases, Stage IV in 11 including one recurrent case; 1 course in 18 and 2 or more courses in 18) in the second. The overall response rate was 65.3% (CR in 3 cases) in the initial study and 63.9% (CR in 5 cases) in the second. Primary cases showed a response rate of 65.9% (29/44) in the initial study and 71.0% (22/31) in the second, whereas recurrent cases showed a 60.0% (3/5) response rate in the initial study and a 20.0% (1/5) rate in the second. Treatment-naive patients showed a response rate of 72.7% (24/33) in the initial study and 71.0% (22/31) in the second, whereas previously treated patients showed a 50.0% (8/16) response rate in the initial study and a 20.0% (1/5) rate in the second. Adverse reactions of more than Grade 3 in the initial study were leukopenia in 18.4%, thrombocytopenia in 8.2%, decrease of hemoglobin in 6.1%, loss of hair in 6.1%, anorexia in 36.7%, nausea and vomiting in 26.5%, and diarrhea in 4.1%, whereas those of Grade 3 in the second study were decrease of hemoglobin in 2.8%, anorexia in 22.2% and nausea and vomiting in 8.3%. From these results, it is suggested that the regimen in the second study was more useful than that in the initial study.

Traffic control: Rab GTPases and the regulation of interorganellar transport

Membrane proteins, membrane lipids, and luminal contents are exchanged among the intracellular compartments of eukaryotic cells by vesicular transport. This process must be highly ordered to maintain cellular architecture in the face of rapid membrane turnover. The Ras-related Rab GTPases play multiple roles in regulating this traffic.

Calmodulin binding to the C-terminus of the small-conductance Ca2+-activated K+ channel hSK1 is affected by alternative splicing

We identified three splice variants of hSK1 whose C-terminal structures are determined by the independent deletion of two contiguous nucleotide sequences. The upstream sequence extends 25 bases in length, is initiated by a donor splice site within exon 8, and terminates at the end of the exon. The downstream sequence consists of nine bases that compose exon 9. When the upstream sequence (hSK1(-)(25b)) or both sequences (hSK1(-)(34b)) are deleted, truncated proteins are encoded in which the terminal 118 amino acids are absent. The binding of calmodulin to these variants is diminished, particularly in the absence of Ca2+ ions. The first 20 amino acids of the segment deleted from hSK1(-)(25b) and hSK1(-)(34b) contain a 1-8-14 Ca2+ calmodulin binding motif, and synthetic oligopeptides based on this region bind calmodulin better in the presence than absence of Ca2+ ions. When the downstream sequence (hSK1(-)(9b)) alone is deleted, only the three amino acids A452, Q453, and K454 are removed, and calmodulin binding is not reduced. On the basis of the relative abundance of mRNA encoding each of the four isoforms, the full-length variant appears to account for most hSK1 in the human hippocampus, while hSK1(-)(34b) predominates in reticulocytes, and hSK1(-)(9b) is especially abundant in human erythroleukemia cells in culture. We conclude that the binding of calmodulin by hSK1 can be modulated through alternative splicing.

Incident-angle dependence of the sensitivity of second-harmonic generation of an oxacyanine dye in an LB film

The second-harmonic generation of a cyanine dye in an LB film was investigated by varying the incident angle of the excitation laser. There was a clear dependence on the incident angle, which was simulated by a simple model. Thus, a highly sensitive determination should be carried out at such an angle where the efficiency of the second-harmonic generation shows its maximum.

U73122 inhibits the dephosphorylation and translocation of cofilin in activated macrophage-like U937 cells

Cofilin, an actin-binding protein, plays an important role in the migration, phagocytosis, and superoxide production of activated phagocytes through cytoskeletal reorganization. In unstimulated phagocytes, cofilin is a major phosphoprotein. However, upon activation, the phosphoprotein is dephosphorylated and translocated from cytosol to plasma membranes. Only the unphosphorylated form of cofilin is an active form that binds actin, whereas the regulatory mechanisms of cofilin have not been elucidated. We found that 1-[6-[[17beta-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122), an inhibitor of phospholipase C (PLC), suppressed both opsonized zymosan (OZ)-induced dephosphorylation and translocation of cofilin in macrophage-like U937 cells at 4 microM concentration. OZ triggered an increase in inositol 1,4,5-trisphosphate (IP3), and U73122 inhibited it. 1-[6-[[17beta-3-Methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-pyrrodione-dione (U73343), which was employed as an inactive analogue, had no such inhibitory activities as did U73122. Furthermore, herbimycin A, an inhibitor of src-type tyrosine kinase, also inhibited OZ-triggered IP3 formation. These results suggest that the activity and localization of cofilin are regulated by PLC at the downstream of src-family tyrosine kinase.

Nitric oxide induces chemotaxis of neutrophil-like HL-60 cells and translocation of cofilin to plasma membranes

Nitric oxide (NO) plays various important roles in the physiological system. With regard to chemotaxis of neutrophils, there are reports that endogenous NO is a mediator of chemotaxis, and others that exogenous NO inhibits chemotaxis. It is also reported that NO itself expressed chemotactic activity. On the other hand, we have recently proposed the importance of cofilin, an actin-binding phosphoprotein, in phagocyte functions through dephosphorylation and translocation to the plasma membrane regions. Because chemotaxis is a phenomenon of dynamic cell movement, cofilin, a regulator of the cytoskeletal system, may be involved in its mechanisms. To clarify further the effect of NO on functions of leukocytes and to examine the effect of NO on cofilin, we investigated the chemotaxis of neutrophil-like HL-60 cells induced by NO, as well as the influence of NO on the phosphorylation and intracellular distribution of cofilin. Two NO donors, 3-[2-hydroxy-1-(1-methylethyl)-2-nitrosohydrazino]-1-propanamin e (NOC5) and S-nitroso-N-acetylpenicillamine (SNAP), were shown to cause chemotaxis, and, 2-(4-carboxyphenyl)-4,4,5, 5-tetramethylimidazole-1-oxyl 3-oxide (carboxy-PTIO), a NO-specific scavenger, inhibited the chemotaxis induced by NO-donors, suggesting that NO itself released from the NO donors has chemotactic activity. LY-83583 and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ), inhibitors of soluble guanylate cyclase, inhibited the chemotaxis to NO donors, which implies that soluble guanylate cyclase is involved in the signaling pathway of this NO action. We also found that NO caused translocation of cofilin to the cell periphery, though dephosphorylation of cofilin was not detected. These results demonstrate that NO has chemotactic activity for neutrophils and caused the translocation of cofilin to the plasma membrane regions without its dephosphorylation.

Gene structure and promoter function of murine Munc18-2, a nonneuronal exocytic Sec1 homolog

Sec1 family proteins are regulators of diverse exocytic processes, from yeast to man. Three mammalian homologues, Munc18-1, -2, and -3 have been described. We have studied the structure and expression of the mouse Munc18-2 gene. The Munc18-2 gene comprises 19 exons whose sizes range from 50 to 158 bp, with a total gene size of approximately 11 kb. A single transcript of 2.1 kb is expressed in multiple non-neuronal murine tissues. Munc18-2 has a striking resemblance to Munc18-1 in structure despite only 60% sequence identity, suggesting a recent gene duplication event. Analysis of the region upstream of the transcription start site shows that Munc18-2 has a TATA-less promoter, with a consensus initiator (Inr) sequence at the start of transcription, several Sp1 binding sites, and strong promoter activity in RBL-2H3 mast cells. The region from +5 to -430 is more active than +5 to -800, suggesting upstream repressor elements.

Genomic organization, chromosomal localization, and expression of the murine RAB3D gene

Rab proteins, members of the Ras superfamily of small GTPases, play regulatory roles in intercompartmental vesicular transport. Each step of traffic seems to require the participation of at least one distinct Rab, with the Rab3 subfamily involved in stimulated exocytosis. We report our studies on the murine rab3D gene, one of the four mammalian Rab3 isoforms. We located this gene on chromosome 13, region A(2-3). The rab3D gene consists of 5 exons spanning 10.6 kb, and the structural gene is contained in exons 2 through 5 with one canonical GTP-binding motif in each exon. Organization of the rab3D gene is identical to that of rab3A but different from other rab genes. Alternative poly-A(+) signals in the 3' untranslated region account for the identities of multiple transcripts detected by Northern blot analysis. Rab3D is expressed in all tissues studied, predominantly in heart, lung, and liver, and binding sites for multiple transcription factors are found in the TATA-less promoter region.

Bisphosphonates for steroid induced osteoporosis

OBJECTIVES

To assess the effects of bisphosphonates for the prevention and treatment of corticosteroid-induced osteoporosis.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Group trials register, Medline up to 1997 and Embase1988-1997), and selected hand searching of reference lists was conducted. Hand searching of scientific abstracts from relevant meetings for the last five years was also done. An electronic search in Current Contents was done for the last six months. The Cochrane Controlled Trials Register (CCTR) will be searched for future updates. All languages were included in the search. For practical reasons only those in English were included, but all languages will be retrieved and translated for future updates.

SELECTION CRITERIA

All controlled clinical trials (CCTs) dealing with prevention or treatment of corticosteroid-induced osteoporosis with bisphosphonates of any type and reporting the outcomes of interest were assessed. Trials had to involve adults only, and subjects had to be taking a mean steroid dose of 7.5 mg/day or more.

DATA COLLECTION AND ANALYSIS

All data extraction was performed by two independent reviewers. Outcomes of interest included change in bone mineral density (BMD) at the lumbar spine and femoral neck at six and 12 months. If present, data on number of new fractures and withdrawals due to adverse effects were also extracted. All data extraction was performed by two independent reviewers. Both continuous and dichotomous data were analyzed using fixed effects models. When significant heterogeneity was present, a random effects model was used.

MAIN RESULTS

A total of 13 trials, including 842 patients are included in this meta-analysis. Results are reported as a weighted mean difference of the percent change in BMD between the treatment and placebo groups, with trials being weighted by the inverse of their variance. The 95% confidence intervals (95% CI) are presented. At the lumbar spine, the weighted mean difference of BMD between the treatment and placebo groups was 4.3% (95% CI 2.7, 5.9). At the femoral neck, the weighted mean difference was 2.1% (95%CI 0. 01, 3.8). Although there was a 24% reduction in odds of spinal fractures [OR 0.76 (95%CI 0.37, 1.53)], this result was not statistically significant.

REVIEWER'S CONCLUSIONS

Bisphosphonates are effective at preventing and treating corticosteroid-induced bone loss at the lumbar spine and femoral neck. Efficacy regarding fracture prevention cannot be concluded from this analysis, although bone density changes are correlated with fracture risk.

The Canadian SCORE questionnaire: optimizing the use of technology for low bone density assessment. Simple Calculated Osteoporosis Risk Estimate

The Simple Calculated Osteoporosis Risk Estimation (SCORE) questionnaire is a tool to assist physicians to identify women who might require bone densitometry. The purpose of this study was to develop a Canadian SCORE and to assess validity and reliability. Twenty sites enrolled 307 postmenopausal women ages 50-70 yr. SCORE results were compared to hip and lumbar spine bone density assessed by dual X-ray absorptiometry. Sensitivity and specificity of a range of SCORE cut-points were assessed in a receiver operating characteristics analysis to determine the optimal cut-point for SCORE. With low bone density defined as a T-score < or = -2.0, a SCORE cut-point of 6 in women ages 50-59 yr displayed a sensitivity of 0. 96, 95% confidence interval (CI) (0.89, 1.00), a specificity of 0.51, 95% CI (0.43, 0.58). In women ages 60-70 yr, a SCORE cut-point of 8 displayed a sensitivity of 0.90, 95% CI (0.80, 0.97) and a specificity of 0.20, 95% CI (0.11, 0.29). The test-retest reliability (intraclass correlation coefficient) was 0.95. SCORE performed better in women in their fifties than women in ther sixties. Older women require higher SCORE cut-points. The use of SCORE as an initial measure for identifying those at risk for osteoporosis may reduce costs by limiting unnecessary tests.

Herbimycin A inhibits both dephosphorylation and translocation of cofilin induced by opsonized zymosan in macrophagelike U937 cells

We previously reported that a 21-kDa phosphoprotein may play an important role in superoxide production through dephosphorylation by neutrophillike differentiated HL-60 cells (Suzuki et al., 1995, Biochim Biophys Acta 1266: 261-267). The phosphoprotein was identified as cofilin, an actin-binding protein, and the activation-induced changes in its intracellular distribution have been described elsewhere (Suzuki et al., 1995, J Biol Chem 270:19551-19556). However, the physiologic roles of cofilin in phagocytes remain to be established, and the regulatory mechanisms for dephosphorylation and translocation of cofilin are unknown. In the present study, we investigated the roles of cofilin in the opsonized zymosan (OZ)-activated macrophagelike U937 cells by using herbimycin A, an inhibitor for protein tyrosine kinase. In the individual adherent phagocytes, OZ induced many events: 1) production of superoxide, 2) phagocytosis of the insoluble particles OZ, 3) dephosphorylation of cofilin, 4) translocation of cofilin from cytosol to plasma membrane regions, 5) decrease in intracellular pH from 7.4 to aprroximately 6.8, and 6) rapid and transient increase in filamentous actin at the cell periphery. All of these events were inhibited or reduced significantly by herbimycin A. OZ increased phosphorylation of tyrosine in 110-, 50-, 34-, and 29-kDa proteins, whereas herbimycin A inhibited it. These results suggest that tyrosine kinase plays an essential role upstream of these events through phosphorylation of such proteins. Furthermore, microinjection of anti-cofilin antibody to the differentiated U937 cells caused inhibition of the phagocytosis. These results suggest that cofilin plays critical roles in phagocytic functions through changes in cytoskeletal organization.

Synaptotagmin II negatively regulates Ca2+-triggered exocytosis of lysosomes in mast cells

Synaptotagmins (Syts) I and II are believed to act as Ca2+ sensors in the control of neurotransmission. Here we demonstrate that mast cells express Syt II in their lysosomal fraction. We further show that activation of mast cells by either aggregation of FcepsilonRI or by Ca2+ ionophores results in exocytosis of lysosomes, in addition to the well documented exocytosis of their secretory granules. Syt II directly regulates lysosomal exocytosis, whereby overexpression of Syt II inhibited Ca2+-triggered release of the lysosomal processed form of cathepsin D, whereas suppression of Syt II expression markedly potentiated this release. These findings provide evidence for a novel function of Syt II in negatively regulating Ca2+-triggered exocytosis of lysosomes, and suggest that Syt II-regulated secretion from lysosomes may play an important role in mast cell biology.

Participation of cofilin in opsonized zymosan-triggered activation of neutrophil-like HL-60 cells through rapid dephosphorylation and translocation to plasma membranes

We studied the roles of cofilin, an actin-binding phosphoprotein, in superoxide production of neutrophil-like HL-60 cells triggered by opsonized zymosan (OZ). OZ caused dephosphorylation of cofilin as well as a transient increase of F-actin. Both reactions were complete within 30 s. Okadaic acid (OA) magnified the OZ-triggered O2--production 3.3-fold at 1 microM, but inhibited it completely at 5 microM. We used these critical concentrations to study the effects of OA on changes in phosphorylation and intracellular localization of cofilin. The OZ-induced dephosphorylation of cofilin was inhibited by 5 microM OA but not by 1 microM OA. Subcellular fractionation and immunoblotting revealed that 1 microM OA increased cofilin on the phagosomal membranous fraction but 5 microM OA decreased it. At 1 microM, OA increased translocation of p47phox to membranes, which may explain in part the enhancing effect of 1 microM OA. Confocal laser scanning microscopy showed that: (i) Cofilin diffused throughout the cytosol of resting cells, but accumulated at the plasma membranes forming phagocytic vesicles in activated cells. (ii) At 1 microM, OA had little effect on the OZ-evoked translocation of cofilin, whereas 5 microM OA suppressed it completely. (iii) OA alone, which could not trigger the phagocytic respiratory burst, did not cause any change in the distribution of cofilin at such concentrations. Furthermore, in a superoxide-producing cell-free system employing membranous and cytosolic fractions, affinity-purified anti-cofilin antibody showed an enhancing effect. These results suggest that cofilin participates in the superoxide production of the OZ-activated phagocytes through dephosphorylation and translocation. The roles of cofilin in the activated leukocytes will be discussed.

Rab3D, a small GTPase, is localized on mast cell secretory granules and translocates to the plasma membrane upon exocytosis

Although mast cell secretion has been intensively studied because of its pivotal role in allergic reactions and its advantages as a physiologic model, the molecular composition of the secretory machine is virtually unknown. In view of the guanine-nucleotide dependency of mast cell exocytosis and the participation of Rab3 proteins in synaptic vesicle release, we hypothesized that a Rab3 isoform regulates mast cell secretion. Fragments of Rab3A, 3B, and 3D were cloned from RBL-2H3 mast cells by reverse transcription- polymerase chain reaction (RT-PCR). Northern blot analysis revealed Rab3D transcripts to be relatively abundant, Rab3B substantially less so, and Rab3A and 3C undetectable. By ribonuclease (RNase) protection assay, Rab3D transcripts were at least 10-fold more abundant than those of other isoforms, and by immunoblot analysis, Rab3D protein was at least 60-fold more abundant than that of Rab3B. Rab3D was more abundant in RBL cells than in brain, but the total mass of Rab3 proteins in RBL cells was 10-fold less than in brain. Rab3D only partly colocalized with secretory granules in RBL cells, but fully colocalized in mature peritoneal mast cells. There was a descending concentration gradient of Rab3D from peripheral to central granules, and no cytoplasmic pool was detectable in resting mast cells. Following exocytotic degranulation, Rab3D translocated to the plasma membrane and remained there for at least 15 min. These studies suggest that Rab3D is a component of the regulated exocytotic machine of mast cells, and identify differences between mast cells and neurons in Rab3 expression and trafficking.

Atrial natriuretic peptide modulates alveolar type 2 cell adenylyl and guanylyl cyclases and inhibits surfactant secretion

Alveolar epithelial type 2 (T2) cells isolated from the lungs of adult rats responded to exogenous atrial natriuretic peptide (ANP) by two signalling mechanisms. First, ANP induced a dose-dependent reduction of ligand-stimulated adenylyl cyclase activity and cAMP accumulation. This effect was inhibited by the addition of GDPbetaS or by pretreatment with pertussis toxin (PT), consistent with mediation by a Gi protein(s). PT-catalyzed [32P]ADP-ribosylation, immunoblots with specific antisera, and Northern blot analysis demonstrated that T2 cells contain the G-proteins Gi2 and Gi3 which could transduce this signal. ANP also promoted PT-insensitive, dose-dependent accumulation of cGMP, consistent with activation of a receptor guanylyl cyclase. Isoproterenol-stimulated phosphatidylcholine secretion was markedly attenuated by ANP, and this effect was inhibited by PT pretreatment, consistent with mediation by a Gi protein(s). These data indicate that in addition to the lung being a major clearance organ for circulating ANP, lung parenchymal cells are targets of ANP action.

Measurement of cytokine levels by coronary sinus blood sampling during cardiac surgery with cardiopulmonary bypass

Interleukin-6, interleukin-8, and polymorphonuclear leukocyte elastase levels in coronary sinus blood were measured and compared with those in arterial blood drawn from the radial artery before and immediately after cardiopulmonary bypass (CPB) during coronary artery bypass grafting in 20 patients. We introduced coronary sinus blood sampling as a useful method for evaluation of myocardial metabolism, myocardial protection, and reperfusion injury during CPB, especially by measurement of cytokines. Because interleukin-6, interleukin-8, and polymorphonuclear leukocyte elastase are inflammatory mediators, we speculated that they might show higher levels in coronary sinus blood than in systemic arterial blood. The results obtained from the 20 patients showed that levels of interleukin-6, interleukin-8, and polymorphonuclear leukocyte elastase increased immediately after CPB (p < .01), but there was no significant difference in these levels between coronary sinus and systemic arterial blood. We conclude that the myocardium is not a predominant source of their release during CPB. Our results also showed that the measurement of these cytokines in systemic arterial blood reflected their levels in the whole body, including the myocardium, even during cardiac operation with CPB.

Comparison of chorionic villus sampling and amniocentesis: current status of prenatal diagnosis in Japan

Data were tabulated and compared for cases involving prenatal diagnostic procedures performed in the 8 years between January 1985 and December 1992. Of a total of 2781 pregnancies, 2546 cases (91.5 per cent) were diagnosed by amniocentesis, and 235 (8.5 per cent) by chorionic villus sampling (CVS). These findings reflect the fact that amniocentesis has taken deep root as the prenatal diagnostic procedure widely acknowledged by society, whereas even the existence of CVS has yet to be generally recognized. Analysis of our clinical and laboratory results and complication rates, however, suggests that CVS is a safe and accurate alternative to amniocentesis which should and can be positively presented to all patients who are candidates for prenatal diagnosis.

Effect of cerebral venous congestion on the pressure-volume index in the evaluation of intracranial pressure dynamics

Translocation of cerebrospinal fluid (CSF) between the intracranial and spinal subarachnoid space was blocked by ligating the cervical spinal core in eight cats under pentobarbital and nitrous oxide anesthesia, and the effects of cerebral venous congestion on the pressure-volume index (PVI), a measure relating the change in intracranial volume, and the logarithm of intracranial pressure (ICP) were evaluated. The changes in the volume-pressure response (VPR), a measure of intracranial elastance, were calculated simultaneously. Cerebral venous congestion was induced by lowering the head relative to the level of the heart by tilting the trunk of the animals to 20 degrees below horizontal. The presence of venous congestion was confirmed by an increase in the sagittal sinus pressure (SSP). The body position was shifted from horizontal prone (H1 group) to head-down tilt (D1 group) in four animals (group 1) and from head-down tilt (D2 group) to horizontal prone (H2 group) in the other four animals (group 2), and PVI and VPR were determined in each group. The changes in ICP and SSP with change of body position in group 1 were not significantly different from those in group 2, with both pressures changing by 7-8 mm Hg. PVI showed no significant differences between the H1 group and H2 group or between the D1 group and D2 group. The mean (+/- SEM) PVI for all measurements in the head-down tilt position (D1 and D2 groups) was significantly higher (0.50 +/- 0.02 ml; p < 0.01) than in the horizontal position (H1 and H2 groups; 0.35 +/- 0.02 ml).(ABSTRACT TRUNCATED AT 250 WORDS)

99mTc-HMDP accumulation in a phyllodes tumor of the breast, a case report

In a patient with breast tumor, 99mTc-HMDP accumulation in the tumor was recognized in evaluating bone metastasis. Surgery and histopathology revealed that the tumor was a phyllodes tumor. This scintigraphic finding was thought to be rare and phyllodes tumor should be included in differential diagnosis when 99mTc-HMDP accumulation in the breast was recognized.

Effects of lipid peroxidation on surface charge density of the porcine intestinal brush-border membranes

The effects of lipid peroxidation on the surface charge density of the porcine intestinal brush-border membranes were studied using an oxygen-radical-generating system consisting of ascorbic acid, ferrous ion and tert-butyl hydroperoxide (tert-BuOOH). Changes in the membrane surface charge density were monitored using a fluorescent dye, 8-anilino-1-naphthalenesulfonate (ANS). The incubation of the membranes with ascorbic acid/Fe2+/tert-BuOOH resulted in a decrease of the fluorescence intensity of the ANS-membrane complex with a red-shift in the emission maximum, depending on the hydroperoxide concentration and the incubation time. The kinetic studies on ANS-binding showed that the apparent dissociation constant of ANS-membrane complex decreased by treatment with ascorbic acid/Fe2+/tert-BuOOH. Similar results were also obtained by treatment of the membranes with other oxidizing systems, hematin/tert-BuOOH and dipyridyl/Fe2+/tert-BuOOH. These results proposed the possibility that lipid peroxidation of the membranes causes an increase of the positive charge on the membrane surface. The results of the dependence of the ionic strength with increasing KCl concentrations in the medium upon the ANS-binding affinity for the membranes further supported this interpretation.

Molecular analysis of five independent Japanese mutant genes responsible for hypoxanthine guanine phosphoribosyltransferase (HPRT) deficiency

Five independent mutations in the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene were identified in a partially HPRT deficient patient with gout and in four Lesch-Nyhan patients. Using the polymerase chain reaction (PCR) technique coupled with direct sequencing, the nucleotide sequences of the entire HPRT coding region amplified from the cDNA and also of each exon amplified form the genomic DNA were analyzed. Three independent point mutations in the coding region were detected in the partially HPRT deficient patient (Case 1) and in two Lesch-Nyhan patients (Case 2 and 3), resulting in single amino acid substitutions. The family study of Case 3, utilizing a PvuII restriction site created in the mutant gene, indicated that the mother was a heterozygote, and a sister and a fetal brother had inherited the normal HPRT gene from the mother. In two other mutants causing Lesch-Nyhan syndrome, a portion of the HPRT gene was deleted, and RNA splicing was missing in both mutants. A 4-bp deletion at the 5' end of exon 4 resulted in formation of three different types of abnormal mRNA (Case 4). The other mutant (Case 5) produced abnormal mRNA including 26 bp of intron 8 instead of the deleted 58 bp at the 5' end of exon 9, because of a 74-bp deletion from intron 8 to exon 9.

[Mathematical simulation of intracranial condition--Part 1. Linear model stimulation]

We developed a linear mathematical model of the intracranial vessels, which reflects changes of the pulse wave (pulse pressure) of intracranial pressure after ligation of the internal jugular vein. The model composed of eight major variables: 1. resistance of arteries, 2. resistance of small arteries and capillary vessels, 3. resistance of veins, 4. resistance of internal jugular and vertebral veins, 5. compliance of arteries, 6. compliance of small arteries and capillary vessels, 7. compliance of veins and 8. intracranial compliance. All variables are presumed to have linear elements and replaced with electrical elements. The model of neck dissection is expressed as the change of resistance of the internal jugular and vertebral veins. Intracranial condition is expressed as the pulse wave (pulse pressure) of intracranial pressure and driving pressure. After unilateral ligation of the internal jugular vein, the pulse wave of intracranial pressure increased 24% and, after bilateral ligation of the internal jugular vein, it increased 55%. After unilateral ligation of the internal jugular vein, the pulse wave of intracranial pressure increased 27%, and, after bilateral ligation, it increased 79%. When intracranial compliance is normal, the respective ratios of pulse wave of intracranial pressure and driving pressure to cross-sectional area decreased, whereas those after increase of intracranial compliance increased.

Fetal cells in the maternal circulation: detection of Y-sequence by gene amplification

Detection of a Y-specific sequence in the maternal circulation has clinical importance because it would be useful in determining fetal gender in mothers with severe X-linked disorders. The method described in this paper has the advantage of requiring only small amounts of maternal blood. Numerous attempts have been made to identify XY cells in the blood of mothers bearing male fetuses; however, the results have been controversial. In this study, a member of the DYZ1 family and the XY homologous region of the amelogenin gene were used as targets for polymerase chain reaction detection of the Y chromosome. The subjects in this study were a group of 100 pregnant women at 17-20 weeks' gestation and 30 puerperal women who had given birth 2-5 days previously. All of the former underwent amniocentesis, with venous blood samples drawn before the procedure. Forty-five fetuses were confirmed as male by karyotyping amniocytes, and 30 of these were positive for the Y sequence in the DYZ1 region (sensitivity 66.7%). However, ten of the 55 cases diagnosed as female were also positive, giving a specificity of only 81.8%. Thus, the positive and negative predictive values were each 75%. In the amelogenin gene study, a positive Y signal was not detected in any of the cases examined. This study demonstrates the usefulness of polymerase chain reaction detection of Y-specific sequences in the maternal circulation. However, further investigation is necessary to increase the reliability for clinical application, because the method does produce false-positive results.

[Assessment of myocardial viability with 201Tl myocardial SPECT 24 hours after injection]

Recently many investigators reported that conventional stress-redistribution myocardial scintigraphy with 201Tl underestimated the presence of ischemic but viable myocardium. We studied the usefulness of 24 hour 201Tl myocardial single photon emission computed tomography (SPECT) to assess myocardial viability and investigated the factors affect to the quality of 24 hour SPECT images. Study patients were consisted with 70 patients with old myocardial infarction (OMI), 72 patients with angina pectoris without OMI (AP) and 43 patients with angiographically proven normal coronary arteries. To obtain SPECT images, 10 minute and 4 hour imagings were sampled 30 seconds per projection. Twenty-four hour imaging was sampled 60 seconds per projection. Twenty-four hour images were visually interpreted as good, moderate and poor quality. Then study patients were divided into 2 groups, group A with good 24 hour images and group B with moderate or poor 24 hour images. One hundred and fifty-eight patients (85.4%) of study patients had 24 hour SPECT images on a good quality. Only 4 patients (2.2%) had poor quality SPECT. All of these 4 patients had broad myocardial infarction. In patients with OMI 61 patients (87.1%), in AP 63 patients (87.5%) and in normal 35 patients (81.4%) had a good 24 hour SPECT. Total sampling counts and myocardial ROI counts were significantly higher in group A than in group B. Body weight was significantly higher and there were more male patients in group B than in group A. Late redistribution was seen in 20 patients (28.5%) with OMI and in 11 patients (15.3%) with AP.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of selenium in generalized and localized argyria: report of four cases with X-ray microanalysis

Electron microscopic and X-ray microanalytic studies were performed on four cases of argyria; one generalized and three localized. Deposition of electron dense granules was predominantly found on elastic fibers and around basal laminas of secretory portions of eccrine glands, although the amount of deposition was much less in the case of generalized argyria. In all four cases, X-ray microanalysis revealed that the depositions consisted mainly of silver, selenium, and sulfur. The importance of selenium in the detoxification of heavy metals was discussed.

Changes in surface charge density of lecithin liposomes by lipid peroxidation. A fluorescence study with 8-anilino-1-naphthalenesulfonate

Treatment of lecithin liposomes with 100 microM ascorbic acid and 10 microM ferrous ion resulted in the formation of fluorescent products exhibiting an emission maximum at 430 nm and a decrease in the fluorescence intensity of 8-anilino-1-naphthalenesulfonate (ANS) bound to the liposomes without change in the emission maximum. The degree of ascorbic acid/Fe(2+)-induced decrease in the ANS fluorescence was dependent on the extent of fluorescent product formation. The results of kinetic studies on ANS-binding to the liposomes showed that treatment of the liposomes with ascorbic acid/Fe2+ causes an increase of the apparent dissociation constant (Kd) of ANS-liposome complex. This indicates that lipid peroxidation of the liposomes by treatment with ascorbic acid/Fe2+ decreases the binding affinity of ANS to the liposomes. In addition, it was also found that there is a good correlation between degrees of the Kd value and the formation of fluorescent products. The fluorescence properties, i.e. emission maximum and response of the fluorescence intensity for borohydride reduction, of the products formed by lipid peroxidation of the liposomes were similar to those derived from modification of the liposomes with monofunctional aldehydes such as acetaldehyde and heptaldehyde. From these results, it is suggested that the decrease of ANS-binding affinity to the liposomes by treatment with ascorbic acid/Fe2+ may be due to changes in the surface charge density of the liposomes relating to the formation of fluorescent products.

Prenatal diagnosis of rubella infection by fetal blood sampling

Prenatal diagnosis of rubella infection was attempted at 21 to 23 weeks of gestation by measuring rubella-specific IgM by ELISA in blood obtained from 16 fetuses whose mothers had been confirmed rubella infection during pregnancy. Specific IgM was detected in 9 fetuses. In 1 case, the time of the appearance of the rash was 20 weeks of gestation and this pregnancy went to term resulting in a healthy baby without clinical evidence of congenital rubella. The remaining 8 patients had their pregnancies terminated, and fetal infection was confirmed by blood tests after the abortion. No specific IgM was detected in the 7 other fetuses. However, in 2 IgM fetal blood negative cases whose mothers had had the rash at 17 and 20 weeks of gestation, the neonates showed positive IgM findings, but were apparently healthy. The reasons for the false-negative findings are discussed.