A novel endo-type chitinase possessing chitobiase activity derived from the chitinolytic bacterium, Chitiniphilus shinanonensis SAY3T

One of the chitinases (ChiG) derived from the chitinolytic bacterium Chitiniphilus shinanonensis SAY3T exhibited chitobiase activity cleaving dimers of N-acetyl-D-glucosamine (GlcNAc) into monomers, which is not detected in typical endo-type chitinases. Analysis of the reaction products for GlcNAc hexamers revealed that all the five internal glycosidic bonds were cleaved at the initial stage. The overall reaction catalyzed by chitobiases toward GlcNAc dimers was similar to that catalyzed by N-acetyl-D-glucosaminidases (NAGs). SAY3 possesses two NAGs (ChiI and ChiT) that are thought to be important in chitin catabolism. Unexpectedly, a triple gene-disrupted mutant (ΔchiIΔchiTΔchiG) was still able to grow on synthetic medium containing GlcNAc dimers or powdered chitin, similar to the wild-type SAY3, although it exhibited only 3% of total cellular NAG activity compared to the wild-type. This indicates the presence of unidentified enzyme(s) capable of supporting normal bacterial growth on the chitin medium by NAG activity compensation.

Distinct Profiles of Desensitization of µ-Opioid Receptors Caused by Remifentanil or Fentanyl: In Vitro Assay with Cells and Three-Dimensional Structural Analyses

Remifentanil (REM) and fentanyl (FEN) are commonly used analgesics that act by activating a µ-opioid receptor (MOR). Although optimal concentrations of REM can be easily maintained during surgery, it is sometimes switched to FEN for optimal pain regulation. However, standards for this switching protocol remain unclear. Opioid anesthetic efficacy is decided in part by MOR desensitization; thus, in this study, we investigated the desensitization profiles of REM and FEN to MOR. The efficacy and potency during the 1st administration of REM or FEN in activating the MOR were almost equal. Similarly, in β arrestin recruitment, which determines desensitization processes, they showed no significant differences. In contrast, the 2nd administration of FEN resulted in a stronger MOR desensitization potency than that of REM, whereas REM showed a higher internalization potency than FEN. These results suggest that different β arrestin-mediated signaling caused by FEN or REM led to their distinct desensitization and internalization processes. Our three-dimensional analysis, with in silico binding of REM and FEN to MOR models, highlighted that REM and FEN bound to similar but distinct sites of MOR and led to distinct β arrestin-mediated profiles, suggesting that distinct binding profiles to MOR may alter β arrestin activity, which accounts for MOR desensitization and internalization.

In Vitro Analyses of Spinach-Derived Opioid Peptides, Rubiscolins: Receptor Selectivity and Intracellular Activities through G Protein- and β-Arrestin-Mediated Pathways

Activated opioid receptors transmit internal signals through two major pathways: the G-protein-mediated pathway, which exerts analgesia, and the β-arrestin-mediated pathway, which leads to unfavorable side effects. Hence, G-protein-biased opioid agonists are preferable as opioid analgesics. Rubiscolins, the spinach-derived naturally occurring opioid peptides, are selective δ opioid receptor agonists, and their p.o. administration exhibits antinociceptive effects. Although the potency and effect of rubiscolins as G-protein-biased molecules are partially confirmed, their in vitro profiles remain unclear. We, therefore, evaluated the properties of rubiscolins, in detail, through several analyses, including the CellKey^TM assay, cADDis^® cAMP assay, and PathHunter^® β-arrestin recruitment assay, using cells stably expressing µ, δ, κ, or µ/δ heteromer opioid receptors. In the CellKey^TM assay, rubiscolins showed selective agonistic effects for δ opioid receptor and little agonistic or antagonistic effects for µ and κ opioid receptors. Furthermore, rubiscolins were found to be G-protein-biased δ opioid receptor agonists based on the results obtained in cADDis^® cAMP and PathHunter^® β-arrestin recruitment assays. Finally, we found, for the first time, that they are also partially agonistic for the µ/δ dimers. In conclusion, rubiscolins could serve as attractive seeds, as δ opioid receptor-specific agonists, for the development of novel opioid analgesics with reduced side effects.

Inhibition of endothelin A receptor by a novel, selective receptor antagonist enhances morphine-induced analgesia: Possible functional interaction of dimerized endothelin A and μ-opioid receptors

BACKGROUND

The misuse of opioids has led to an epidemic in recent times. The endothelin A receptor (ETAR) has recently attracted attention as a novel therapeutic target to enhance opioid analgesia. We hypothesized that endothelin A receptors may affect pain mechanisms by heterodimerization with μ opioid receptors. We examined the mechanisms of ETAR-mediated pain and the potential therapeutic effects of an ETAR antagonist, Compound-E, as an agent for analgesia.

METHODS

Real-time in vitro effect of Compound-E on morphine response was assessed in HEK293 cells expressing both endothelin A and μ opioid receptors through CellKey™ and cADDis cAMP assays. Endothelin A/μ opioid receptor dimerization was assessed by immunoprecipitation and live cell imaging. The in vivo effect of Compound-E was evaluated using a morphine analgesia mouse model that observed escape response behavior, body temperature, and locomotor activity.

RESULTS

In CellKey™ and cAMP assays, pretreatment of cells with endothelin-1 attenuated morphine-induced responses. These responses were improved by Compound-E, but not by BQ-123 nor by bosentan, an ETAR and endothelin B receptor antagonist. Dimerization of ETARs and μ opioid receptors was confirmed by Western blot and total internal reflection fluorescence microscopy in live cells. In vivo, Compound-E potentiated and prolonged the analgesic effects of morphine, enhanced hypothermia, and increased locomotor activity compared to morphine alone.

CONCLUSION

The results suggest that attenuation by endothelin-1 of morphine analgesia may be caused by dimerization of Endothelin A/μ opioid receptors. The novel ETAR antagonist Compound-E could be an effective adjunct to reduce opioid use.

The G Protein Signal-Biased Compound TRV130; Structures, Its Site of Action and Clinical Studies

Opioid agonists elicit their analgesic action mainly via μ opioid receptors; however, their use is limited because of adverse events including constipation and respiratory depression. It has been shown that analgesic action is transduced by the G protein-mediated pathway whereas adverse events are by the β-arrestin-mediated pathway through μ opioid receptor signaling. The first new-generation opioid TRV130, which preferentially activates G protein- but not β-arrestin-mediated signal, was constructed and developed to reduce adverse events. TRV130 and other G protein-biased compounds tend to elicit desirable analgesic action with less adverse effects. In clinical trials, the intravenous TRV130 (oliceridine) was evaluated in Phase I, II and III clinical studies. Here we review the discovery and synthesis of TRV130, its main action as a novel analgesic having less adverse events, its up-to-date status in clinical trials, and additional concerns about TRV130 as demonstrated in the literature.

Peripartum type B aortic dissection in patients with Marfan syndrome who underwent aortic root replacement: a case series study

OBJECTIVE

To investigate pregnancy outcomes, especially the risk of pregnancy-related aortic dissection (AD), in patients with Marfan syndrome (MFS) after prophylactic aortic root replacement (ARR).

DESIGN

Retrospective case series study.

SETTING

Tertiary perinatal care centre at a university hospital.

POPULATION

Pregnant women fulfilling the revised Ghent nosology (2010) criteria for MFS who were managed at our institute.

METHODS

The pregnancy outcomes of all patients with MFS managed at our institute between 1982 and September 2016 were reviewed retrospectively based on medical records.

MAIN OUTCOME MEASURES

Obstetrical management and complication including the incidence of AD throughout the peripartum period.

RESULTS

Among 22 patients (28 pregnancies) who had been managed as potential MFS or related disorders, 14 (17 pregnancies) fulfilled the revised Ghent nosology (2010) criteria for MFS and were enrolled in this study. Five patients (five pregnancies) had received ARR before conception: three (60%) developed type B aortic dissection [AD(B)] during the peripartum period, compared with only one of 10 patients (12 pregnancies) without ARR (P < 0.05, Chi-square test).

CONCLUSIONS

Our study results suggest that MFS patients after prophylactic ARR are still at high risk of AD(B) during the peripartum period. Careful pre-pregnancy counselling and multidisciplinary care throughout the peripartum period are essential for the management of MFS, even after surgical repair of an ascending aortic aneurysm.

TWEETABLE ABSTRACT

MFS patients after prophylactic ARR are still at high risk of type B aortic dissection during the peripartum period.

Subunit-specific and homeostatic regulation of glutamate receptor localization by CaMKII in Drosophila neuromuscular junctions

For the efficient transfer of information across neural circuits, the number of synaptic components at synapses must be appropriately regulated. Here, we found that postsynaptic calcium/calmodulin dependent protein kinase II (CaMKII) modulates the localization of glutamate receptors (GluRs) at Drosophila larval neuromuscular junctions (NMJs). Expression of an inhibitory peptide of CaMKII, Ala, in muscle cells enhanced the density of GluRIIA, which is a major and calcium-permeable subunit of GluR, at synapses of third instar larval NMJs. On the other hand, postsynaptic expression of a constitutively active form of CaMKII (T287D) reduced synaptic GluRIIA. These results suggest that CaMKII regulates GluRIIA at NMJs. Moreover, postsynaptic expression of T287D abolished the accumulation of the scaffolding protein discs large (DLG) at synapses, while exerting no significant effects on the presynaptic area and the localization of cell adhesion molecule fasciclin II (FasII). The amplitude of excitatory junctional potentials (EJPs) was enhanced in Ala-expressing larvae, whereas it was unaffected in T287D-expressing larvae in spite of the prominent loss of GluRIIA. The amplitude of miniature EJPs (mEJPs) was significantly reduced and quantal content was significantly increased in T287D-expressing larvae. Notably, another class of GluR containing GluRIIB was enhanced by the postsynaptic expression of T287D. These results suggest that the homeostatic mechanism in T287D larvae works to maintain the level of synaptic responses. Thus, the Drosophila larval NMJs have several regulatory systems to ensure efficient muscle excitability which is necessary for proper larval movement.

Bioactivation of titanium surfaces using coatings of TiO(2) nanotubes rapidly pre-loaded with synthetic hydroxyapatite

Apatite depositions from simulated body fluid (SBF) have been widely used for the in vitro assessment of the bioactivity of bone- and dental-implant materials. In previous work, we reported that titanium-based implant materials can be coated with an anodic TiO(2) nanotube layer which can significantly stimulate apatite formation. In the present work, we demonstrate that the tubular nature of such coatings makes them highly suitable for the application of a treatment called "alternative immersion method (AIM)", which preloads the coatings with synthetic hydroxyapatite. This treatment is indeed found to additionally promote natural apatite formation significantly. To study the AIM effect, layers of nanotubes with various diameters and crystal structures (amorphous, anatase/rutile) were produced, AIM-treated, and the formation of apatite in SBF10 (10mmol1(-1) HCO(3)(-)) was evaluated. The results show a drastic enhancement of apatite deposition rates (in some cases >20-fold acceleration) for AIM-treated TiO(2) nanotube layers in comparison with non-treated TiO(2) surfaces.

Presence of functional domains in NADPH-dependent cytosolic 3,5,3'-Triiodo-L-thyronine (T3)-binding protein (p38CTBP) molecule: analyses with deletion mutants

Functional domains required for NADPH-binding, T(3)-binding, protein dimerization and cytosolic retention were analyzed in NADPH-dependent cytosolic 3,5,3'-triiodothyronine (T(3))-binding protein (p38CTBP) by using the deletion mutants. Wild-type p38CTBP (amino acids; 1-314) and a series of deletion mutants (amino acids; 1-79, 1-128, 1-146, 1-216, 37-314, and 1-145 with 270-314) were bacterially induced. NADPH-dependent T(3)-binding activity was not observed in all mutant p38CTBPs studied, although wild-type p38CTBP showed high-affinity T(3)-binding activity. Wild-type p38CTBP was able to bind a CL-6B column, none of the mutant p38CTBPs showed any binding activity. Pull-down analyses demonstrated that two regions between amino acid 128 and 146, and between 216 and 270, both of which possess helical structures, were required for homodimeric p38CTBP binding. In fluoroscopic studies, GFP-tagged p38CTBP was preferentially observed in cytoplasm. However, C-terminal region-deleted p38CTBP(1-216) was not only observed in cytoplasm, but also in nucleus. These results suggest that 1) multiple regions in p38CTBP molecule are required for T(3)-binding and NADPH binding, 2) two helical structures in p38CTBP molecule may be important in the homodimer formation, and 3) C-terminal region of p38CTBP contains the function to preserve the protein in cytoplasm.

Cloning and expression of CitPDS1, a gene encoding phytoene desaturase in citrus

A cDNA clone encoding phytoene desaturase (PDS) was isolated from citrus (Citrus unshiu Marc.). The transcript of the isolated PDS (CitPDS1) was not detected by conventional RNA gel-blot analysis; instead, it was detected by a sensitive reverse transcription-PCR (RT-PCR). The CitPDS1 transcript in the juice sacs/segment epidermis (edible part) was at a low level in the young fruit, and it increased toward maturation like citrus phytoene synthase (CitPSY1). In the peel, in contrast to CitPSY1, the transcript of which was induced toward maturation, the level of the CitPDS1 transcript remained constant after an increase in July, indicating non-coordinate regulation of CitPDS1 and CitPSY1 in the peel.

Structure, expression, and conserved physical linkage of mouse testicular cell adhesion molecule-1 (TCAM-1) gene

Isolation and characterization were performed for cDNA encoding mouse testicular cell adhesion molecule-1 (TCAM-1) using 2908 bases coding for a protein having 548 amino acids (60 kDa). Mouse TCAM-1 protein was found to consist of seven domains for signal sequence, five immunoglobulin (Ig) domains, and the transmembrane plus cytoplasmic domain. TCAM-1 gene and the region linking it to growth hormone (GH) gene located downstream from the TCAM-1 gene were then analyzed. The mouse TCAM-1 gene was 11.6 kb in length with 8 exons; the same as for the 12.0 kb rat gene. The distance from the TCAM-1 to GH gene was 12.5 kb in the mouse genome, and 7.6 kb in the rat. By Northern hybridization, 3.1-kb TCAM-1 mRNA was detected in 17-day testis and would appear present in pachytene spermatocytes and round spermatids.

Selective inhibition of cyclooxygenase-2 with antisense oligodeoxynucleotide restricts induction of rat adjuvant-induced arthritis

The effects of cyclooxygenase (COX)-2 antisense oligodeoxynucleotide (ODN) in induction of adjuvant-induced arthritis were investigated. Female Lewis rats were injected with Mycobacterium butyricum intradermally at the base of tails to induce arthritis. Synthetic 18 mer phosphorothioate ODNs corresponding to the translation initiation site of rat COX-2 mRNA were prepared. The antisense (AS), sense (S), and "scrambled" (Sc) ODNs were intraperitoneally administered. Arthropathy was evaluated with arthritis score, paw edema, and histological examination. Expression of COX-1 and -2 protein and mRNA were examined with immunostaining and reverse-transcription polymerase chain reaction, respectively. COX-2 AS ODN significantly suppressed induction of arthritis in a dose-dependent manner without severe adverse effects, whereas S and Sc ODNs did not show significant inhibitory effects. COX-2 mRNA and protein expression were also suppressed only by COX-2 AS ODN without any alteration of COX-1 expression. These data suggest that selective inhibition of COX-2 with AS ODN may have a therapeutic potency in the treatment of rheumatoid arthritis.

A tyramine receptor gene mutation causes a defective olfactory behavior in Drosophila melanogaster

We characterized molecular profiles of a new olfactory mutant line, honoka (hono), which was found among 500 viable P-element insertion lines screened first by 5-bromo-4-chloro-3-indrolyl-beta-D-galactopyranoside (X-gal) staining on the third segment of the antenna, and then by behavioral assays to several pure chemicals. The behavioral responses of hono mutants to repellents such as ethyl acetate (EA), benzaldehyde (BZ) and 4-methylcycrohexanol (MCH), were reduced compared with those of a control strain. The location of the P-element insertion was determined to be about 100bp) upstream of the first exon of the tyramine receptor gene. The level of 3.6kb tyramine receptor mRNA expression was reduced in hono compared with that of wild-type flies. The tyramine receptor cDNA hybridized to the chromosomal division 79C-D, the same locus as the P-element insertion point in hono, and not to 99A-B, previously reported by Arakawa et al. (1990. Neuron 2, 343-354). Electrophysiological responses to octopamine and tyramine were examined by measuring the excitatory junctional potential (EJP) amplitude from larval body-wall muscles of the hono mutant. The hono was impaired with responding to tyramine, while displaying normal response to octopamine. These results indicate that tyramine has a functional role in the Drosophila olfactory system as a neurotransmitter or a neuromodulator, and hono is the first tyramine receptor mutant. This study provides the first step toward understanding of the molecular genetics of tyramine-mediated neural functions in Drosophila.

Molecular cloning of a homologue of dad-1 gene in citrus: distinctive expression during fruit development

A cDNA homologue to the human defender against apoptotic death gene (dad-1), which is involved in programmed cell death, was isolated from satsuma mandarin (Citrus unshiu Marc.) fruit. It (Citdad-1-1) was 345 bp long, with a deduced protein sequence of 115 amino acids. Southern hybridization suggests that dad-1-related sequences are present as a small gene family in the citrus genome. Expression of Citdad-1-1 was progressively down-regulated in leaves as they matured, but not in juice sac/segment epidermis (edible part) towards fruit ripening. The role of dad-1 during citrus development is also discussed.

Neural expression of hikaru genki protein during embryonic and larval development of Drosophila melanogaster

Hikaru genki (HIG) is a putative secreted protein of Drosophila that belongs to immunoglobulin and complement-binding protein superfamilies. Previous studies reported that, during pupal and adult stages, HIG protein is synthesized in subsets of neurons and appears to be secreted to the synaptic clefts of neuron-neuron synapses in the central nervous system (CNS). Here we report the analyses of distribution patterns of HIG protein at embryonic and larval stages. In embryos, HIG was mainly observed in subsets of neurons of the CNS that include pCC interneurons and RP5 motorneurons. At third instar larval stage, this protein was detected in a limited number of cells in the brain and ventral nerve cord. Among them are the motorneurons that extend their axons to make neuromuscular junctions on body wall muscle 8. Immunoelectron microscopy showed that these axonal processes as well as the neuromuscular terminals contain numerous vesicles with HIG staining, suggesting that HIG is in a pathway of secretion at this stage. Some neurosecretory cells were also found to express this protein. These data suggest that HIG functions in the nervous system through most developmental stages and may serve as a secreted signalling molecule to modulate the property of synapses or the physiology of the postsynaptic cells.

Cloning and expression analysis of vacuolar H+-ATPase 69-kDa catalytic subunit cDNA in citrus (Citrus unshiu marc.)1

To investigate the mechanism of sugar accumulation in fruit vacuoles, a full length cDNA (CitVATP-A) encoding the vacuolar H+-ATPase 69-kDa catalytic subunit was isolated from a cDNA library constructed from citrus fruit (Citrus unshiu Marc.). A 2304-bp insert of CitVATP-A was coded for a 623 amino acid polypeptide with a predicted molecular mass of 68.68 kDa. The deduced amino acid sequence for CitVATP-A showed a 96.5% homology with the carrot homologue. Genomic Southern blot analysis suggested that CitVATP-A is a low-copy number gene. Northern blot analysis of leaves and fruits during the developing stages showed that the level of expression is high in young leaves and is low in mature leaves, and that it increased in both the edible parts and the peel, during fruit growth and maturity.

[Hansen's disease and nephropathy as its sequence]

Nephropathy as the sequences of Hansen's disease before and after the introduction of chemotherapy was compared referring to the report by Hayashi in 1943 and the summary of the autopsy reports from 1978 to 1981 at National Hansen's disease hospital Zenseien. Unlike the high rates of tuberculosis as the cause of death before the introduction of chemotherapy (41.3%) those thereafter decreased to be negligible. On the other hand the comparison of the rates of nephropathy with the same way as that of tuberculosis was impossible since the description about nephropathy by Hayashi was not sufficient to characterize each nephropathy since he included arteriolitis, glomerulonephritis and interstitial nephritis together in the term of nephritis. Death rate due to nephritis among Hansen's disease patients according to Hayashi at that time was 21.2% which was twice as many comparing to that in the other cases. According to the report about the cases of Zenseien those reported to have glomerulonephritis was 37.3% though those were not necessarily listed as the cause of death. Also the nephropathy including fibrinoid angitis with occasional microaneurysmal dilatation of afferent arteries, glomerulitis, sclerosis and stricture of efferent arteries likewise ischemic acute tubular necrosis possibly as the result of these angiopathy seemed to be present. These vascular changes partially resemble to that of microscopic periarteritis nodosa but seems to be common in the smaller arteries. In conclusion, unlike the case of tuberculosis the rate of nephritis including glomerulitis, arteriolitis and interstitial nephritis as Hayashi used as his criteria does not seem to have decreased. Therefore, the critical analysis of the nephropathy especially of that relating to the arteriolitis should be done to obtain the knowledge to suppress its occurrence.

Genetic dissection of sexual behavior in Drosophila melanogaster

Mating of Drosophila melanogaster is a sterotypically patterned behavior consisting of a fixed sequence of actions that are primarily under genetic control. Mutations that disrupt specific aspects of mating activities offer a starting point for exploring the molecular machineries underlying sexual behavior. Several genes, identified as causing aberrant sexual behavior when mutated, have been isolated and cloned, providing molecular probes for expression and mosaic analyses that can be used in specifying the cells responsible for the behavior. This review presents current understandings of mating behavior obtained by such molecular and cellular approaches and provides an overview of future directions of research in behavioral genetics.

Cloning and molecular analysis of cDNAs encoding three sucrose phosphate synthase isoforms from a citrus fruit (Citrus unshiu Marc.)

Three partial cDNA clones (pSPS1, pSPS2 and pSPS3) encoding sucrose phosphate synthases (SPS) were isolated by Reverse Transcription (RT)-PCR using first-strand cDNA prepared from the leaf or fruit of citrus (Citrus unshiu Marc.). The nucleotide and deduced amino acid sequences of the three clones showed significant similarities to SPS previously isolated in other plants. A full-length, cDNA clone, CitSPS1, was isolated from a fruit (juice sacs and pulp segment) cDNA library using one (pSPS1) of the three partial clones as a probe. The 3539-bp CitSPS1 clone coded for a 1057-amino acid polypeptide with a predicted molecular mass of 117.8 kDa. The amino acid sequence deduced from the CitSPS1 clone showed homology with SPS from maize (55.8% identity) and spinach (74.0% identity). Genomic Southern blot analysis suggested that CitSPS1 clone represents a lowcopy-number gene. RNA blot analysis of leaf, flower and fruit showed that CitSPS1 and pSPS2 were expressed in all organs. However, the levels of expression of CitSPS1 in young leaves, flowers and immature fruits were low, but high in mature leaves, and fruit. pSPS2 transcripts were barely detectable in young leaves and immature fruits, low in mature leaves, and high in flowers and mature fruits. pSPS3 transcripts were only detected in young and in mature leaves.

A study of the development of atherosclerosis in childhood and young adults: risk factors and the prevention of progression in Japan and the USA. The Pathobiological Determinants of Atherosclerosis in Youth (PDAY) Research Group

Coronary heart disease (CHD), one of the prevalent results of atherosclerotic disease, has been a leading cause of death in many Western countries for several decades, and now is the second most prevalent cause of death in Japan. Thus attention must also be paid to atherosclerosis in Japan. While there has been a remarkable reduction in the mortality rate from CHD in some Western countries, an undesirable stabilized mortality rate has recently been reported by the government of Japan. This report emphasises the importance of preventing atherosclerosis at an early stage from the viewpoint of cardiovascular pathology, using evidence from statistical data derived from autopsied cases in Japan and the USA.

On the beta-glucuronidase binding protein (BGBP) of microorganisms. Its purification, the antiserum preparation against that and its localization in leproma and the other infectious lesions shown by immunohistologic method

Our previous studies suggested that M. leprae (ML) grow in peripheral nerves and lepra cells because ML metabolize hyaluronic acid (HA), and use its component for their growth by the aid of host enzyme combined to the bacilli derived beta-glucuronidase binding protein (BGBP). In this study, therefore, we examined the method to purify BGBP from a mycobacterium HI-75 originally separated from a leproma and cultured by modified Ogawa's medium containing split products of HA (glucuronic acid and N-acetylglucosamine). The distribution of BGBP in leproma and the other lesions consisting of hepatitis B virus infected liver and M. avium-intracellulare infected lung tissue were also immunohistologically examined. As the result, the best method to get BGBP was preparatory electrophoresis in the final step of the purification and not the molecular sieving. The BGBP was actually proven in leproma and the other infected tissues as described, indicating the abilities of these microorganisms to utilize the metabolic machinery of the host with the similar ways to that of ML.

Purification and characterization of two lectins from the sea cucumber Stichopus japonicus

Two Ca(2+)-dependent lectins were purified from the sea cucumber Stichopus japonicus by affinity chromatography on lactosyl-Sepharose 4B and ion-exchange chromatography on Q-Sepharose. Their molecular masses were estimated to be 13kDa (SJL-I) and 15 kDa (SJL-II) on SDS-PAGE. SJL-I agglutinated rabbit erythrocytes as well as human A, B, and O-type erythrocytes, but SJL-II agglutinated only rabbit erythrocytes. Hemagglutination by SJL-I was competitively inhibited by N-acetyl-D-galactosamine and galactose-containing carbohydrates. On the other hand, only lactose, melibiose, and raffinose gave weak inhibition of hemagglutination by SJL-II, suggesting that SJL-II may have high specificity for particular complex carbohydrate(s) on the surface of rabbit erythrocytes. SJL-II was activated at ten times lower Ca2+ concentration than SJL-I. Both lectins lost activity in acidic pH, while SJL-I appeared more stable down to pH 4.5.

[The interaction between neural activity and intracellular pH]

The regulation of intracellular pH (pH(i)) in the nervous system has been vigorously studied using a variety of animal cells in the last decade, through advances in techniques for measuring pH(i) accurately in living cells. These studies have elucidated the mechanisms of pH(i) regulation, such as intracellular buffering and acid transport across the cell membrane, in neurons and glial cells. Following an outline of pH(i) regulation, the interaction between neural activity and acid-base balance is discussed. The dynamic change of pH(i), produced by neural activity, and the effect of pH(i) on the electrical properties of neurons and other excitable cells is emphasized.

[Gross anatomical study of veins in the orbit]

The aim of this study is to clarify the major route of venous return in the orbit. Minute dissections were performed in 10 adult cadavers (5 males and 5 females) after being fixed in a 10% formalin solution. The superior ophthalmic vein (SOV) and its ascending anastomotic branch were consistently well-developed (the average maximum diameter: 6.2mm and 3.2mm, respectively) and these two veins formed the main venous channel from the orbital contents. The ascending anastomotic branch ran between the optic nerve and the medial rectus just behind the eyeball and joined the SOV. A large number of veins, including the inferior ophthalmic vein, which originated from the inferior contents of the orbit, drained into the ascending anastomotic branch. Arteries and/or nerves did not accompany their respective veins in the orbit, except for the lacrimal and ethmoidal veins. The posterior end of the SOV was severely narrowed lateral to the aponeurosis of the lateral rectus, while being conspicuously dilated just behind the eyeball. The above findings suggested that the dilated portion of SOV may act as a reservoir of the venous return of the orbit.

[Radiation therapy for unresected gastric lymphoma]

Six consecutive patients with unresected gastric lymphoma which were treated by radiation therapy between November, 1976 and March 1989 were reviewed. Radiation therapy was performed using involved fields, total radiation dosages of which ranged from 25.2 to 36 Gy (mean, 29.3 Gy). Five out of the 6 patients were treated with chemotherapy combined with radiation. Regimen of the chemotherapy was CHOP (cyclophosphamide, adriamycin, vincristine and prednisone) in most cases. Three out of the 6 underwent probe laparotomy, but the tumors were diagnosed as unresectable due to locally invading the adjacent structures. They were treated by chemo-radiotherapy and 2 of them are surviving as of the present study (40 and 116 months). The other 3 patients were diagnosed as with clinical stage IV disease and 2 of them were successfully treated with chemo-radiotherapy (21 and 66 months, surviving). These data suggest that unresected gastric lymphomas, which are locally advanced or stage IV disease, are treated by chemoradiotherapy with high curability without any serious complications.

[The role of gallium-67 citrate scintigraphy in gastro-intestinal malignant lymphoma]

To evaluate the clinical usefulness of gallium-67 scintigraphy in the detection of the gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, gallium-67 scintigraphy was reviewed on 24 cases (25 lesions; stomach in 20, ileum in 2, and terminal ileum and/or cecum in 3). Twenty-three out of the 25 lesions (92.0%) were detected by gallium-67 scintigraphy, while barium study could detect all of the 25 lesions. The sizes of the gallium-67 negative 2 lesions were the smallest of all (2.5 and 3.0 cm). The tumor size was considered to the most important factor in the detection by gallium-67 scintigraphy, while the histological classification and the location of the tumor were not related to its detectability. Findings in follow-up gallium-67 scintigraphy after therapy on 10 cases were correlated well with the therapeutic effects. These data suggest that gallium-67 scintigraphy is useful for the detection of GI involvement of NHL and for the assessment of therapeutic effects.

Mutational and gene dosage analysis of calcium-activated potassium channels in Drosophila: correlation of micro- and macroscopic currents

In Drosophila, two Ca2(+)-activated K+ currents, ICF and ICS, have previously been distinguished in conventional voltage clamp experiments. The slowpoke (slo) mutation eliminates ICF specifically. We report that in patch clamp recordings a single-channel Ca2(+)-activated K+ current is readily distinguished from other channel activities in normal larval muscle membrane, whereas no such current is observed in slo muscles. This single-channel current thus correlates with the macroscopic ICF. No obvious differences in amplitude or properties were detected between normal (+/+) and heterozygous (slo/+) ICF channels in whole-cell voltage clamp recordings or single-channel patch clamp recordings. These results are consistent with the hypothesis that slo is a structural gene for the ICF channels only under certain conditions. The selective effect of the slo mutation may reflect a defect in a regulatory mechanism that is specific for the functioning of the ICF channel protein.

The role of gallium 67 imaging in non-Hodgkin's lymphoma of the gastrointestinal tract

To evaluate the clinical usefulness of gallium 67 imaging in the detection of gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, images were reviewed in 24 cases (25 lesions: stomach, 20; ileum, 2; and terminal ileum and or cecum, 3) and were compared using barium studies and, in 16 cases, computerized tomography (CT). In all, 23 (92.0%) of the 25 lesions were detected by 67Ga citrate imaging, the barium studies detected all 25, and CT detected 15 of 16 lesions (93.8%). The two lesions not identified by imaging and the one not found by CT were the smallest of all. In 2 (8.7%) of the 23 lesions positively identified by 67Ga-citrate imaging, both CT and imaging revealed the extent of the tumor more accurately than did the barium studies. In all but one of the patients, a close correlation existed between the imaging results and the therapeutic effects. These data suggest that 67Ga imaging is useful in conjunction with CT and barium studies for the detection of GI NHL and for the assessment of both the spatial extent of disease and the therapeutic effects, although a lack of 67Ga uptake after therapy does not always indicate a good therapeutic effect.

Age-related changes in cerebral white matter measured by computed cranial tomography

Changes in the cerebral white matter in relation to aging were studied quantitatively by computed cranial tomography (CT) in 70 healthy subjects aged 30 to 94 years. There were no age-related changes in the CT number of the white matter (WMCT) in 41 younger subjects aged 30 to 65 years. But, there was a significant negative correlation between age and the WMCT in 29 elderly subjects aged 66 to 94 years. Brain atrophy was significantly correlated with the WMCT. The WMCT decreased with aging even in neurologically healthy elderly persons.

Central respiratory oscillator: phase-response analysis

To investigate properties of the central respiratory oscillator, phrenic nerve activity, perturbed by electrical stimulation of the middle external intercostal nerve, was analyzed in rabbit by using a phase-response curve (PRC). During inspiration, the stimuli (4-8 pulses) caused all-or-none responses, i.e. a phase advance or no phase shift, and strong stimuli (10 pulses) induced only phase advances. During expiration only graded phase delays were observed. The overall slope of PRC was 0 for 2 pulses and 1 for 10 pulses. At the transition from expiration (E) to inspiration (I), the PRC was discontinuous. This discontinuity corresponds to a phase singularity. In contrast, at the transition from I to E, the PRC was continuous. Therefore, our findings indicate that E-I switching may differ from I-E switching in nature. The respiratory rhythm could not be stopped by perturbation at the phase singularity as predicted from the PRCs. Similarities between the reported PRCs, obtained by inhibitory stimulation of an endogenous bursting neuron and the PRCs in the present study, suggest a possibility that endogenous bursting neurons take part in the function of a mammalian central respiratory oscillator.

Application of a drug delivery system to a steroidal ophthalmic preparation with lipid microspheres

The applicability of a drug delivery system to an ophthalmic preparation was examined using lipid microspheres containing hydrocortisone 17-butyrate 21-propionate (HBP). A 3H-labelled HBP ophthalmic suspension and 3H-labelled HBP lipid microspheres were applied to rabbit eyes, which were then enucleated at fixed intervals to determine the level of 3H-labelled HBP in ocular tissues. The lipid microspheres were shown to deliver the drug to the anterior ocular tissues more effectively than the ophthalmic suspension. It is suggested that a lipid microsphere ophthalmic preparation of various lipophilic drugs including steroids may be useful as a drug delivery system for ophthalmic therapy.

Normal pressure hydrocephalus. Neuropathological study

The pathological changes in the brains of seven patients who had been clinically diagnosed as normal pressure hydrocephalus (NPH) are described and the possible etiological mechanisms are discussed. The pathological findings in all cases consisted of demyelination akin to Binswanger's type of encephalopathy, especially in the frontal lobes. Arteriosclerosis accompanied by occasional organized thrombi and scattered microinfarcts in the periventricular white matter were seen. Focal leptomeningeal fibrosis, diminution of arachnoidal granulations, and non-specific aging processes were noted. Among the above of particular interest, was the degeneration of both periventricular and deep white matters with microinfarcts, and moderate to severe arteriosclerosis. On the basis of these observations, we assume that the degeneration in the white matter is not merely a secondary change due to the result of enlargement of ventricle, but plays an important role in the development of NPH. The development of NPH requires not only the disturbance of cerebrospinal fluid, but also the pre- or coexisting vulnerability in the white matter caused by variables such as ischemia, hypoxia, and trauma.

Amplification of N-myc in a rhabdomyosarcoma

N-myc is a member of the myc oncogene family and has been thought to be specific to neurogenic cells, since it is amplified in some neuroblastomas, retinoblastomas and small-cell lung carcinomas with endocrine properties. Hybridization analyses of DNAs isolated from surgically removed tumors revealed that N-myc was amplified about 6-fold in one of the three embryonic rhabdomyosarcomas examined. The rhabdomyosarcoma containing the amplified N-myc had metastasized into bone marrow, which is preferentially involved in the metastasis of neuroblastomas but is usually not involved in the case of rhabdomyosarcomas. Since rhabdomyoblasts are derived from mesenchyme, this indicates that N-myc gene amplification is not restricted to neurogenic tumors.

Synaptic input driving respiratory motoneurons in dragonfly larvae

Intracellular recordings were made from respiratory motoneurons in dragonfly larvae. Current injection into a motoneuron did not affect other respiratory motoneuron activity. Long-lasting hyperpolarizing current injection revealed that both inspiratory and expiratory motoneurons receive excitatory and inhibitory synaptic input with a reverse phase.