Exogenous Ceramide Serves as a Precursor to Endogenous Ceramide Synthesis and as a Modulator of Keratinocyte Differentiation

Since ceramide is a key epidermal barrier constituent and its deficiency causes barrier-compromised skin, several molecular types of ceramides are formulated in commercial topical agents to improve barrier function. Topical ceramide localizes on the skin surface and in the stratum corneum, but certain amounts of ceramide penetrate the stratum granulosum, becoming precursors to endogenous ceramide synthesis following molecular modification. Moreover, exogenous ceramide as a lipid mediator could modulate keratinocyte proliferation/differentiation. We here investigated the biological roles of exogenous NP (non-hydroxy ceramide containing 4-hydroxy dihydrosphingosine) and NDS (non-hydroxy ceramide containing dihydrosphingosine), both widely used as topical ceramide agents, in differentiated-cultured human keratinocytes. NDS, but not NP, becomes a precursor for diverse ceramide species that are required for a vital permeability barrier. Loricrin (late differentiation marker) production is increased in keratinocytes treated with both NDS and NP vs. control, while bigger increases in involucrin (an early differentiation marker) synthesis were observed in keratinocytes treated with NDS vs. NP and control. NDS increases levels of a key antimicrobial peptide (an innate immune component), cathelicidin antimicrobial peptide (CAMP/LL-37), that is upregulated by a ceramide metabolite, sphingosine-1-phosphate. Our studies demonstrate that NDS could be a multi-potent ceramide species, forming heterogenous ceramide molecules and a lipid mediator to enhance differentiation and innate immunity.

Design, Synthesis, and Structure-Activity Relationships Study of N-Pyrimidyl/Pyridyl-2-thiazolamine Analogues as Novel Positive Allosteric Modulators of M3 Muscarinic Acetylcholine Receptor

The M₃ muscarinic acetylcholine receptor (mAChR) plays an essential pharmacological role in mediating a broad range of actions of acetylcholine (ACh) released throughout the periphery and central nerve system (CNS). Nevertheless, its agonistic functions remain unclear due to the lack of available subtype-selective agonists or positive allosteric modulators (PAMs). In the course of our extended structure-activity relationships (SARs) study on 2-acylaminothiazole derivative 1, a previously reported PAM of the M₃ mAChR, we successfully identified N-pyrimidyl/pyridyl-2-thiazolamine analogues as new scaffolds. The SARs study was rationalized using conformational analyses based on intramolecular interactions. A comprehensive study of a series of analogues described in this paper suggests that a unique sulfur-nitrogen nonbonding interaction in the N-pyrimidyl/pyridyl-2-thiazolamine moiety enable conformations that are essential for activity. Further, a SARs study around the N-pyrimidyl/pyridyl-2-thiazolamine core culminated in the discovery of compound 3g, which showed potent in vitro PAM activity for the M₃ mAChR with excellent subtype selectivity. Compound 3g also showed a distinct pharmacological effect on isolated smooth muscle tissue from rat bladder and favorable pharmacokinetics profiles, suggesting its potential as a chemical tool for probing the M₃ mAChR in further research.

Medicinal plant extracts protect epithelial cells from infection and DNA damage caused by colibactin-producing Escherichia coli, and inhibit the growth of bacteria

AIMS

To investigate the biological activity of Thai medicinal plant extracts and their active substances on the inhibition of growth and the transcription of colibactin genes of colibactin-producing Escherichia coli, and effect on the pathogenesis from colibactin toxin including transient infections and colibactin-induced DNA damage.

METHODS AND RESULTS

Among 16 medicinal plants examined, aqueous extracts of Terminalia catappa, Psidium guajava and Sandoricum koetjape demonstrated the growth inhibition against E. coli ATCC 25922, which is known to produce colibactin toxin. These plant extracts contain the active phytochemical compounds, tannin and quercetin, which are able to inhibit the growth of E. coli ATCC 25922. Interestingly, the extracts of T. catappa, P. guajava and S. koetjape, and their compounds tannin and quercetin, protected the eukaryotic epithelial cells of Vero cells and Caco-2 cells from infection and DNA damage by E. coli ATCC 25922. Moreover, these plant extracts and compounds exhibited efficacy to downregulate the expression of five genes (clbA, clbB, clbM, clbN and clbP) that are required for colibactin biosynthesis.

CONCLUSIONS

The extracts of T. catappa, P. guajava and S. koetjape, and their compounds of tannin and quercetin had ability to inhibit the growth and transcription of colibactin genes of colibactin-producing Escherichia coli. Hence, these plant extracts and compounds could protect the transient infection and DNA damage of the eukaryotic epithelial cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first of its kind to report on the enhancement of the biological properties of T. catappa, P. guajava and S. koetjape, and to support the exogenous compound usage of tannin and quercetin, which may be able to protect against the transient infection and DNA damage of eukaryotic cells from E. coli carrying colibactin toxin.

Low Molecular Weight Trypsin-Plasmin Inhibitors Isolated from Papain Treated Urinary Trypsin Inhibitor

Papain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.

In Vitro and in Vivo Measurement of Total Antiplasmin Activity

Total antiplasmin was measured in vitro and in vivo. In the former case, rabbit plasma was mixed with various concentrations of Urokinase (UK) and the least concentration for appearance of fibrinolytic activity was estimated. This concentration was multiplied by the plasma volume of the rabbit to give the in vitro total antiplasmin. The mean value for 14 rabbits was 4,068.6 units.

In order to estimate the total antiplasmin in vivo, UK solution was infused into rabbits. The infusion speed was multiplied by the time of the first appearance of fibrinolytic activity to give the total antiplasmin, although when the infusion speed was low, fibrinolytic activity did not appear during infusion. The mean in vivo total antiplasmin calculated for 6 cases where the infusion speed was high and fibrinolytic activity was observed, was 28,699.8 units, i.e. about 7 (range, 3-11) times the in vitro value.

Studies on Blood Coagulation and Fibrinolysis in Patients Bitten by Bothrops jararaca (jararaca)

The blood coagulation and the fibrinolytic systems of nine patients envenomed by Bothrops jararaca in São Paulo (Brazil) were studied. Five of the accidents were caused by young snakes (<50 cm). On admission, four patients had non-clotting and three partially-clotting blood. Fibrinogen levels were decreased due to the thrombin-like activity of the venom as expected. Consequent secondary activation of the fibrinolytic system was evident from the low levels of alpha-2-antiplasmin and the high titres of fibrin(ogen) degradation products. High titres of cross-linked fibrin fragment D (D-dimer) in seven patients together with decreased platelet counts and/or factor V, and/or factor VIII in some, suggests intrinsic thrombin formation as these factors are not consumed in the defibrinogenation induced by venom thrombin-like fractions such as Ancrod and Batroxobin. However, normal or increased levels of antithrombin III in all and normal levels of factor II in eight patients do not support this interpretation. The existence of variable concentrations of other proteins in the venom of B. jararaca such as botrocetin and thrombocytin isolated from B. jararaca and B. atrox or crotalocytin from Crotaliis horridus venom should be considered. Such proteins are known to activate factors V, VIII, XIII, and platelets without affecting prothrombin (factor II) and antithrombin III. Slower recovery of the haemostatic disturbances after antivenom administration to patients bitten by young snakes suggests a more severe coagulopathy in such accidents. This is supported by clinical observations.

Fibrinolytic Activity of Cerebro-Spinal Fluid and the Development of Artificial Cerebral Haematomas in Dogs

Blood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.

A long-term follow-up study of open reduction using Ludloff's approach for congenital or developmental dislocation of the hip

Objectives

There are several reports clarifying successful results following open reduction using Ludloff’s medial approach for congenital (CDH) or developmental dislocation of the hip (DDH). This study aimed to reveal the long-term post-operative course until the period of hip-joint maturity after the conventional surgical treatments.

Methods

A long-term follow-up beyond the age of hip-joint maturity was performed for 115 hips in 103 patients who underwent open reduction using Ludloff’s medial approach in our hospital. The mean age at surgery was 8.5 months (2 to 26) and the mean follow-up was 20.3 years (15 to 28). The radiological condition at full growth of the hip joint was evaluated by Severin’s classification.

Results

All 115 hips successfully attained reduction after surgery; however, 74 hips (64.3%) required corrective surgery at a mean age of 2.6 years (one to six). According to Severin’s classification, 69 hips (60.0%) were classified as group I or II, which were considered to represent acceptable results. A total of 39 hips (33.9%) were group III and the remaining seven hips (6.1%) group IV. As to re-operation, 20 of 21 patients who underwent surgical reduction after 12 months of age required additional corrective surgeries during the growth period as the hip joint tended to subluxate gradually.

Conclusion

Open reduction using Ludloff’s medial approach accomplished successful joint reduction for persistent CDH or DDH, but this surgical treatment was only appropriate before the ambulating stage.

Cite this article: Bone Joint Res 2014;3:1–6.

A heterobimetallic Ga/Yb-Schiff base complex for catalytic asymmetric alpha-addition of isocyanides to aldehydes

Development of a new heterobimetallic Ga(O-iPr)(3)/Yb(OTf)(3)/Schiff base 2d complex for catalytic asymmetric alpha-additions of isocyanides to aldehydes is described. Schiff base 2d derived from o-vanillin was suitable to utilize cationic rare earth metal triflates with good Lewis acidity in bimetallic Schiff base catalysis. The Ga(O-iPr)(3)/Yb(OTf)(3)/Schiff base 2d complex promoted asymmetric alpha-additions of alpha-isocyanoacetamides to aryl, heteroaryl, alkenyl, and alkyl aldehydes in good to excellent enantioselectivity (88-98% ee).

Disease-specific expression of VEGF and its receptors in AML cells: possible autocrine pathway of VEGF/type1 receptor of VEGF in t(15;17) AML and VEGF/type2 receptor of VEGF in t(8;21) AML

Various angiogenic factors, such as vascular endothelial growth factor (VEGF) and an associated molecule, placenta growth factor (PlGF), are thought to be important for normal and malignant hematopoiesis. This study examined mRNA expression of VEGF, PlGF and receptors for these molecules in AML cells and identified the disease-specific patterns of expression. AML M3 having t(15;17) abnormality showed highest expression of VEGF and VEGF receptor type 1 (VEGFR1), suggesting the autocrine pathway of VEGF-VEGFR1. Then, t(8;21) AML demonstrated augmented expression of VEGF and VEGF receptor type 2 (VEGFR2), suggesting VEGF-VEGFR2 autocrine pathway. Then, addition of VEGFR2 kinase inhibitor in Kasumi-1, a t(8;21) AML cell line, resulted in marked inhibition of cell growth, although growth inhibitory effect of R2 kinase inhibitor to HL-60 was marginal. In addition, cell cycle analysis study showed S-phase cell population reduction by R2 kinase inhibitor in Kasumi-1, but not in HL-60. This observation is thought to be the rationale for novel molecular target therapy directed to angiogenic molecules.

Sequential regulation of DOCK2 dynamics by two phospholipids during neutrophil chemotaxis

During chemotaxis, activation of the small guanosine triphosphatase Rac is spatially regulated to organize the extension of membrane protrusions in the direction of migration. In neutrophils, Rac activation is primarily mediated by DOCK2, an atypical guanine nucleotide exchange factor. Upon stimulation, we found that DOCK2 rapidly translocated to the plasma membrane in a phosphatidylinositol 3,4,5-trisphosphate-dependent manner. However, subsequent accumulation of DOCK2 at the leading edge required phospholipase D-mediated synthesis of phosphatidic acid, which stabilized DOCK2 there by means of interaction with a polybasic amino acid cluster, resulting in increased local actin polymerization. When this interaction was blocked, neutrophils failed to form leading edges properly and exhibited defects in chemotaxis. Thus, intracellular DOCK2 dynamics are sequentially regulated by distinct phospholipids to localize Rac activation during neutrophil chemotaxis.

The modified glucose clearance test: a novel non-invasive method for differentiating non-erosive reflux disease and erosive oesophagitis

BACKGROUND

Impaired salivary secretion has been reported to cause abnormal acid clearance from the oesophagus in gastro-oesophageal reflux disease (GERD). However, few studies have explained the differences between non-erosive reflux disease (NERD) and erosive oesophagitis (EO) with respect to salivary secretion. Aim To elucidate these differences, we measured salivary secretion by using the modified glucose clearance test (mGCT).

METHODS

All subjects completed endoscopic examinations, the frequency scale for the symptoms of GERD questionnaire and the mGCT comprising a resting GCT (measured as RGC time) and a chewing-stimulated GCT (SGC time).

RESULTS

Resting glucose clearance time was 18.5 min in control group and significantly longer in NERD and EO groups (28.5 and 39.0 min respectively). SGC time was 6.1 min in control group and 7.2 min in NERD group and significantly longer in EO group (10.2 min) than in the control and NERD groups.

CONCLUSIONS

In the EO group, both resting and stimulated salivary secretions were less than in control group. However, in the NERD group, resting salivary secretion was decreased, but stimulated salivary secretion was similar to that of the control group. Therefore, these results may help in explaining the differences in the pathogenesis of NERD and EO.

Chiral-catalyst-based convergent synthesis of HIV protease inhibitor GRL-06579A

Catalytic asymmetric synthesis of GRL-06579A (1), an HIV-1 protease inhibitor effective against multi-protease-inhibitor-resistant viruses, is described. A convergent strategy that utilizes heterobimetallic multifunctional catalysts developed in our group is a key feature of the synthesis. The chirality of the bicyclic tetrahydrofuran unit of 1 was introduced through Al-Li-bis(binaphthoxide) (ALB) catalyst-controlled Michael addition of dimethyl malonate to racemic 4-O-protected cyclopentenone. ALB afforded not only the trans adduct with up to 96% ee from a matched substrate through kinetic resolution, but also the cis adduct with 99% ee through a catalyst-controlled Michael addition to a mismatched substrate. The Michael addition to produce the unusual cis adduct is described in detail. The framework of the bicyclic tetrahydrofuran was constructed by an intramolecular oxy-Michael reaction. The amino alcohol unit was constructed by an La-Li3-tris(binaphthoxide) (LLB)-catalyzed diastereoselective nitroaldol reaction of N-Boc aldehyde (Boc = tert-butoxycarbonyl) derived from L-phenylalanine. LLB promoted the nitroaldol reaction without racemization of the chiral aldehyde to give the nitroaldol adduct in 85% yield and with 93:7 diastereoselectivity and over 99% ee.

Catalytic asymmetric phase-transfer Michael reaction and Mannich-type reaction of glycine Schiff bases with tartrate-derived diammonium salts

Catalytic asymmetric Michael and Mannich-type reactions of glycine Schiff bases with chiral two-center organocatalysts, tartrate-derived diammonium salts (TaDiASs), are described. On the basis of conformational studies, optimized TaDiASs with a 2,6-disubstituted cyclohexane spiroacetal were newly designed. These TaDiASs catalyzed the asymmetric Michael and Mannich-type reactions of glycine Schiff bases with higher enantioselectivity than previous catalysts. In the Mannich-type reaction, aromatic N-Boc-protected imines (Boc = tert-butoxycarbonyl) as well as enolizable alkyl imines were applicable. As a synthetic application of the catalytic asymmetric Mannich-type reaction with the optimized TaDiASs, we developed a catalytic asymmetric total synthesis of (+)-nemonapride, which is an antipsychotic agent.

Symptoms of depression, prescription of benzodiazepines, and the risk of death in hemodialysis patients in Japan

Many hemodialysis patients in Japan have symptoms of depression, but whether those patients are treated appropriately is unknown. As part of the Dialysis Outcomes and Practice Patterns Study, data on symptoms of depression, physician-diagnosed depression, prescribed medications, and death were collected prospectively in cohorts in Japan (n=1603) and 11 other countries (n=5872). Symptoms of depression were as prevalent in Japan as elsewhere, but in Japan a much smaller percentage of patients had physician-diagnosed depression: only 2% in Japan vs 17% elsewhere. Antidepressants were much less commonly prescribed in Japan: only 1% in Japan vs 17% elsewhere for patients with many and frequent symptoms of depression, and 16% in Japan vs 34% elsewhere for patients with physician-diagnosed depression. In Japan, symptoms of depression were associated with prescription of benzodiazepines (without antidepressants), and patients with physician-diagnosed depression were twice as likely to be given benzodiazepines: 32% in Japan vs 16% elsewhere. Benzodiazepine monotherapy was associated with death (relative risk 1.56, 95% confidence interval (CI), 1.25-1.94), even after adjustments for 13 likely confounders (relative risk 1.27, 95% CI, 1.01-1.59). Hemodialysis patients in Japan with symptoms of depression are given not antidepressants but benzodiazepines, a practice associated with higher mortality.

Bacterial cysteine desulfurases: their function and mechanisms

Cysteine desulfurase is a pyridoxal 5'-phosphate (PLP)-dependent homodimeric enzyme that catalyzes the conversion of L-cysteine to L-alanine and sulfane sulfur via the formation of a protein-bound cysteine persulfide intermediate on a conserved cysteine residue. Increased evidence for the functions of cysteine desulfurases has revealed their important roles in the biosyntheses of Fe-S clusters, thiamine, thionucleosides in tRNA, biotin, lipoic acid, molybdopterin, and NAD. The enzymes are also proposed to be involved in cellular iron homeostasis and in the biosynthesis of selenoproteins. The mechanisms for sulfur mobilization mediated by cysteine desulfurases are as yet unknown, but enzymes capable of providing a variety of biosynthetic pathways for sulfur/selenium-containing biomolecules are probably applicable to the production of cofactors and the bioconversion of useful compounds.

Cutaneous sarcoidosis successfully treated with topical tacrolimus

Sarcoidosis is a disorder characterized by macrophage- and T-cell-mediated responses to as yet unidentified infectious antigens or autoantigens. We describe a 62-year-old woman with a 10-year history of orange-yellow plaques of sarcoidosis on her face. Her cutaneous lesions responded to topical tacrolimus ointment after unsuccessful treatment with topical and systemic corticosteroids. No adverse effects were noted with topical tacrolimus in this patient. We discuss the mode of action by which this immunosuppressive agent may act against sarcoidosis.

Up-regulation of the urokinase-type plasminogen activator receptor by monocyte chemotactic proteins

The urokinase-type plasminogen activator receptor (uPAR) is a multifunctional molecule involved in migration and adhesion of leukocytes to sites of inflammation. Based on our hypothesis that a chemoattractant can stimulate uPAR expression by its target cell, thereby promoting cell migration, we employed three chemokines [monocyte chemotactic protein (MCP)-1, MCP-2 and MCP-3] as chemoattractants, and examined their effect on uPAR expression in a human monocyte-like cell line, U937. Northern blot analysis demonstrated that all three chemokines tested increased the level of uPAR mRNA in time-dependent and dose-dependent manners. Among them, MCP-3 exhibited the most potent effect. Scatchard analysis showed that incubation with MCP-3 (1 x 10(-8) mol/l) for 16 h resulted in a significant increase in the number of uPAR from (6.8 +/- 0.3) x 10(3) to (10.3 +/- 1.6) x 10(3)/cell, and in a slight increase in the equilibrium dissociation constant, K(d). The effect of anti-uPAR antibodies on MCP-3-induced U937 cell migration across an endothelial cell monolayer and a type I collagen layer was assessed by means of the modified Boyden chamber assay. Although MCP-3 caused a three-fold increase in migration, incubation with an antibody to uPAR markedly abrogated the induced cell migration. These results support our hypothesis and suggest that up-regulation of uPAR in target cells might be an important and common feature of chemoattractants.

Expression of endothelial cell-associated molecules in AML cells

Recently, it has been clarified that interaction between hematopoietic cells and endothelial cells is important in normal hematopoiesis and leukemogenesis. In this study, we examined the relationship between AML cells and endothelial cells by analyzing the expression profile of angiogenic factors, angiopoietin-1 (Ang-1), Ang-2, Tie-2 (a receptor for angiopoietins) and vascular endothelial growth factor (VEGF). Our results demonstrated that CD7(+)AML expressed Ang-2 mRNA frequently and integrin-family adhesion molecules (CD11c and CD18) intensively, suggesting the close correlation with endothelial cells. On the other hand, in t(8;21) AML cells, expression of Ang-2 was infrequent and expression of integrin-family adhesion molecules (CD11b, CD11c and CD18) was weak, suggesting the sparse association with endothelial cells. As for CD7(+)AML cells, despite the frequent and intense expression of endothelial cell-associated molecules (such as Ang-2, CD11c and CD18), intensity of Tie-2 expression was quite low (P < 0.05). Ang-2 expressed in CD7(+)AML cells is not considered to act in an autocrine fashion, but to work on endothelial cells to "feed" leukemic cells. Although Ang-2 is recognized as a natural antagonist for Tie-2, our data presented here suggested the alternative role of Ang-2 in the relationship between endothelial cells and leukemia cells, at least in a subset of leukemia such as CD7(+)AML. These results were supported by the study using AML cell lines, KG-1 (CD7 negative) and its subline KG-1a (CD7 positive); KG-1 had mRNA expression profile of Ang-1(+)Ang-2(-)Tie-2(+), while KG-1a showed Ang-1(+)Ang-2(+)Tie-2(-). These difference in the expression profile of angiogenic factors between CD7(+)AML and t(8;21)AML may explain the characteristic morphological features of these leukemias (CD7(+)AML as blastic type and t(8;21)AML as differentiative type).

Follow-up study of conservative treatment for atlantoaxial rotatory displacement

Rotatory displacement of the atlantoaxial joint is one of the causes of torticollis in children. Some of these cases show persistent symptoms and may lead to rotatory fixation; however, only a few studies have been directed to the prognosis of atlantoaxial rotatory displacement after conservative treatment. Clinical and radiographic reviews were performed in 35 patients (16 male and 19 female) with rotatory displacement of the atlantoaxial joint. The mean age at admission was 6.5 (range: 2-12) years old, and the mean follow-up period was 3.4 (1.4-5.8) years. All patients successfully achieved reduction after 2 to 3 weeks of continuous halter traction; however, 9 patients (25.7%) experienced recurrence, and 7 patients (20.0%) had a slight torticollis at follow-up. The duration of symptoms before treatment affected the recurrence rate, and the torticollis was apt to remain in cases with severe displacement at admission.

Cervical posterior fusion with wave-shaped rod under local anesthesia for cervical spondylotic myelopathy: review of 12 patients

STUDY DESIGN

Clinical evaluation of cervical interspinous fusion under local anesthesia in elderly patients with cervical spondylotic myelopathy.

OBJECTIVES

To evaluate the effectiveness of cervical posterior fusion with wave-shaped rods inserted under local anesthesia for elderly high-risk patients with cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

A substantial number of patients cannot undergo surgical interventions under general anesthesia because of their general medical complications. Although such patients would become unable to walk, which might induce a worsening of their general condition, conservative treatments had been adopted as the only treatment for these patients. The authors have obtained satisfactory results by means of posterior interspinous fusion under local anesthesia even in the high-risk patients with severe cervical spondylotic myelopathy. The aims of this surgical technique were to adjust cervical alignment and to stabilize the motion segment(s) without decompression.

PATIENTS AND METHODS

Between May 1989 and August 1998, 12 elderly patients (3 men and 9 women) with cervical spondylotic myelopathy were treated with posterior interspinous fusion using wave-shaped rods inserted under local anesthesia. The average age at the surgery was 76.9 years. The average follow-up period was 5 years 6 months. All patients were unable to walk without any assistance because of their advanced myelopathy. It was felt that all of them would be unable to accept general anesthesia because of their generally poor medical conditions. Preoperative severity of the clinical symptoms and postoperative recovery were evaluated by a scoring system proposed by the Japanese Orthopaedic Association, which had 17 points at full mark.

RESULTS

The average duration of the surgical procedure was 122.8 minutes. The average total blood loss was 118.6 g. No instrument failures were denoted. Neither neural deterioration nor major complication was observed relating to the surgery. Radiographic bony union of the grafted bone was achieved in all patients. Progression of myelopathy was arrested in all 12 patients, and clinical symptoms were improved in 10 patients. The mean Japanese Orthopaedic Association scores had increased from 5.0 to 10.2 points.

CONCLUSIONS

Twelve high-risk patients with cervical spondylotic myelopathy were treated with posterior interspinous fusion using wave-shaped rods inserted under local anesthesia. This method was evaluated as an effective surgical salvage without any mortal complications even in the elderly high-risk patients.

Construction of peptides with nucleobase amino acids: design and synthesis of the nucleobase-conjugated peptides derived from HIV-1 Rev and their binding properties to HIV-1 RRE RNA

In order to develop a novel molecule that recognizes a specific structure of RNA, we have attempted to design peptides having L-alpha-amino acids with a nucleobase at the side chain (nucleobase amino acid (NBA)), expecting that the function of a nucleobase which can specifically recognize a base in RNA is regulated in a peptide conformation. In this study, to demonstrate the applicability of the NBA units in the peptide to RNA recognition, we designed and synthesized a variety of NBA-conjugated peptides, derived from HIV-1 Rev. Circular dichroism study revealed that the conjugation of the Rev peptide with an NBA unit did not disturb the peptide conformation. RNA-binding affinities of the designed peptides with RRE IIB RNA were dependent on the structure of the nucleobase moieties in the peptides. The peptide having the cytosine NBA at the position of the Asn40 site in the Rev showed a higher binding ability for RRE IIB RNA, despite the diminishing the Asn40 function. Furthermore, the peptide having the guanine NBA at the position of the Arg44 site, which is the most important residue for the RNA binding in the Rev, bound to RRE IIB RNA in an ability similar to Rev34-50 with native sequence. These results demonstrate that an appropriate NBA unit in the peptide plays an important role in the RNA binding with a specific contact such as hydrogen bonding, and the interaction between the nucleobase in the peptide and the base in the RNA can enhance the RNA-binding affinity and specificity.

HIV Rev peptides conjugated with peptide nucleic acids and their efficient binding to RRE RNA

HIV Rev peptides conjugated with peptide nucleic acids (PNAs) were designed and synthesized to develop a designing approach for a novel RNA-binding molecule. The binding affinities of PNA-peptides with the Rev responsive element (RRE) RNA were determined by the competition assay using a rhodamine-labeled Rev. The peptide conjugated with an antisense PNA (TGCGC) bound RRE RNA more efficiently than the molecule without the PNA or the peptide sequence.

Construction of peptide conjugates with peptide nucleic acids containing an anthracene probe and their interactions with DNA

We designed and synthesized the peptide nucleic acid (PNA)-peptide conjugates having anthracene chromophores and investigated their interactions with calf thymus DNA, [d(AT)(10)](2), [d(GC)(10)](2), and [d(AT)(10)dA(6)](2). Considering the synthesis compatibility and expecting that a novel DNA analogue, PNA, can improve DNA binding properties of alpha-helix peptides, we attempted to attach thymine PNA oligomers at the C-terminus of a 14 amino acid alpha-helix peptide that contained a pair of artificial intercalators, anthracene, as a probe, and to examine their interactions with DNA using anthracene UV, fluorescence and circular dichroism properties. The results observed in this study showed that the designed peptide folded in an alpha-helix structure in the presence of calf thymus DNA, [d(AT)(10)](2), and [d(AT)(10)dA(6)](2) with the chromophores at the side-chain being fixed with a left-handed chiral-sense orientation. The alpha-helix and the anthracene signals were not observed for [d(GC)(10)](2). Incorporation of thymine PNA oligomers into the designed alpha-helix peptide increased the DNA binding ability to [d(AT)(10)dA(6)](2) with increasing the length of the PNA without changing the conformations of the peptide backbone and the anthracene side-chains.

Biomechanical comparison of posterior cervical fixation

STUDY DESIGN

Biomechanical stability using four different posterior cervical fixation techniques was evaluated in human cadaveric spine.

OBJECTIVES

To introduce an alternative interspinous fixation technique using wavy-shaped rods, and to compare its in vitro biomechanical stability with that of other posterior cervical fixation techniques.

SUMMARY OF BACKGROUND DATA

Fixation of the posterior cervical spine with interspinous wiring is well known as Rogers' or Bohlman's technique. Recently, several plate fixation techniques have been used for posterior cervical stabilization. Since 1983, the authors have developed the wavy-shaped rod system as an alternative to the interspinous fixation technique. This unique technique has been proven clinically useful in Japan. However, the authors are not aware of any prior biomechanical studies.

METHODS

Seven fresh frozen cervical human spines were tested at the C5-C6 motion segment. Nondestructive static biomechanical testing was performed with flexion-extension, lateral bending, and axial rotation for the following stabilization techniques: intact spine, creation of a Stage 3 distractive-flexion injury followed by fixation with the wavy-shaped rods bounded by three multistrand cables, interspinous wiring with a multistrand cable, triple wiring technique using multistrand cables with a pair of unicortical grafts from the ilium, and lateral mass plate fixation with Magerl's screw technique. Testing was performed on a material testing machine (MTS 858 Bionix test system, MTS, Minneapolis, MN), and load displacement curves were obtained using four linear extensometers and one rotatory extensometer across the C5-C6 motion segment.

RESULTS

In axial compression loading, the reconstructed specimens showed significant differences in range of motion measured at the anterior and posterior positions, and statistical analysis was performed using one-way analysis of variance. In a comparison of the four fixation techniques, the construct with the wavy-shaped rod indicated significantly less motion both anteriorly and posteriorly than with the other fixation techniques. Also in flexion-extension loading, all the techniques significantly limited the intervertebral motion below the level of the intact motion segment. Particularly, the construct with the wavy-shaped rod showed the smallest mobility, 49.9% anteriorly and 9.3% posteriorly, compared with that of the intact spine. In lateral bending, the lateral mass plate provided the greatest stability, which was superior to the intact segment, but the difference was not statistically significant. In axial rotation, all the reconstruction techniques limited the angular motion below the intact level (wavy rod, 68.0%; Rogers' wiring, 75.2%; Bohlman's triple wiring, 59.8%; lateral mass plate, 71.7%), but no significant differences were observed using one-way analysis of variance, as compared with the intact segment.

CONCLUSIONS

All four reconstruction techniques restored the stability of the cervical motion segment to at least the level of the intact motion segment before destabilization. An alternative cervical posterior fixation technique, the Wavy Rod system, was considered the most effective technique in stabilizing a cervical motion segment, particularly in axial compression and flexion extension loading.

Multipeptide-metalloporphyrin assembly on a dendrimer template and photoinduced electron transfer based on the dendrimer structure

To construct an artificial photosynthetic system, peptide dendrimers [n-(X-HLY)PAMAMs: X = R, E; Y= L, F; n=4, 8, 16, 32 and 64 segments], in which amphiphilic alpha-helix peptides (X-HLY: R-HLL, E-HLL and R-HLF) were introduced at the end groups of polyamidoamine dendrimers (PAMAMs), were designed and synthesized. The peptide dendrimers 64-(X-HLY)PAMAMs are novel synthetic biopolymers with an enormous molecular weight, about 160 kDa, and with a regulated amino acid sequence and three-dimensional conformation. The peptide dendrimers bound Fe(III)- or Zn(II)-mesoporphyrin IX per two alpha-helices; this afforded a multimetalloporphyrin assembly similar to the natural light-harvesting antennae in photosynthetic bacteria. Circular dichroism studies and peroxidase activity measurements revealed that metalloporphyrins were coordinated to the peptide dendrimers in a regulated manner and packed more densely with the growth of the dendrimer generation. Fluorescence quenching and photoreduction studies with methylviologen demonstrated that the photoinduced electron-transfer function with the peptide dendrimer-multi-Zn-MP was accomplished more effectively as the dendrimer generation increased. Thus, the three-dimensional assembly of metalloporphyrins and peptides in the dendrimer was an effective module for light-harvesting antennae in an artificial photosynthetic system.

Malignant lymphoma of the bone associated with systemic sarcoidosis

A 57-year-old woman was hospitalized with malignant lymphoma of the right talus. After treatment, complete remission was obtained. Gallium-67 scintigraphy to confirm the remission demonstrated increased uptake in the whole body skeletal muscle, especially in her thighs. Biopsy of right gastrocnemius muscle showed epithelioid granuloma. Serum angiotensin-converting enzyme activity (ACE) and lysozyme had increased to several times the normal range. We diagnosed her disease as bone-associated sarcoidosis-lymphoma syndrome. Human herpes virus 8 (HHV-8) genome was examined in the bone marrow specimen, and the relationship between sarcoidosis-lymphoma syndrome and HHV-8 was discussed.

Long-term follow-up results of anterior interbody fusion applied for cervical myelopathy due to ossification of the posterior longitudinal ligament

STUDY DESIGN

A long-term follow-up study was carried out in 30 patients who underwent anterior interbody fusion for cervical myelopathy associated with ossification of the posterior longitudinal ligament (OPLL).

OBJECTIVE

To investigate whether anterior interbody fusion without decompression is an appropriate surgical method for long-term relief of cervical OPLL myelopathy.

SUMMARY OF BACKGROUND DATA

Several studies of operative results after posterior decompression for cervical myelopathy due to ossification of the posterior longitudinal ligament have been reported. There has been no report about anterior interbody fusion without decompression. The postoperative results of this treatment method applied in cervical OPLL myelopathy have been evaluated by the authors of the present study for more than 10 years. No reports on such a long-term follow-up study have been published in the literature.

METHODS

Thirty patients who underwent anterior interbody fusion for cervical OPLL myelopathy were evaluated clinically and radiographically. The mean follow-up period was 14.7 years (range, 10-23 years).

RESULTS

Clinical results were evaluated according to Okamoto's classification. At the time of the final follow-up evaluation, 16 patients had improved in functional score by two grades, and their surgical results were regarded as excellent; eight patients improved by one grade, and their clinical outcomes were regarded as good; five patients showed no change; and the condition of one patient deteriorated. As for radiographic analysis, the type of ossification had changed in four cases. Ossification width and thickness increased in 26 patients. Postoperative alignment of the cervical spine showed kyphosis in three patients, straight spine in 11 patients, and lordosis in 16 patients.

CONCLUSION

Anterior interbody fusion without decompression is an effective treatment for cervical OPLL myelopathy that resulted in stable long-lasting conditions.

Hypertrophy of the posterior longitudinal ligament is a prodromal condition to ossification: a cervical myelopathy case report

STUDY DESIGN

A histopathologic examination of a specimen that showed hypertrophy of the posterior longitudinal ligament of the cervical spine.

OBJECTIVES

To illustrate the possibility of hypertrophy of the posterior longitudinal ligament as a prodromal condition to ossification of the posterior longitudinal ligament.

SUMMARY OF BACKGROUND DATA

Despite much study, the pathology of ossification of the posterior longitudinal ligament still remains unclear. Hypertrophic change often is seen in the part of the ossified ligament; however, there have been few histopathologic reports on hypertrophy of the posterior longitudinal ligament. Some reports have suggested that hypertrophy of the posterior longitudinal ligament is a prodrome of ossification of the posterior longitudinal ligament.

METHODS

A 64-year-old man was admitted to the hospital because of gait disturbance and developed oliguria. In a plain radiograph, segmental ossification of the posterior longitudinal ligament was found at C4, C5, and C6. Computed tomograph myelogram revealed a soft tissue shadow, maximum 3.8 mm in diameter, on the dorsal side of the ossification of the posterior longitudinal ligament at C5 and C6. Magnetic resonance T1-weighted image (T1WI) showed an equivalent signal with the intervertebral disc on the dorsal side of ossification of the posterior longitudinal ligament. This lesion was enhanced with Gd-DTPA and confirmed as hypertrophy of the posterior longitudinal ligament. Cervical anterior decompression and fusion were performed using Yamaura's technique. The ossified and thickened lesion was elevated and removed en bloc. Then, hematoxylin-eosin and toluidine blue staining was performed to detect metachromasia.

RESULTS

Macroscopic examination of the specimen revealed that soft tissue formation was connected with the C4-C5 intervertebral space and extended downward to C6-C7. Histopatholgically, collagen fibers were proliferating in the long-axis direction on both ventral and dorsal sides. This was surrounded by extended nucleus pulposus-like chondrocyte tissue, where endplate cartilage was detected around the C4 pedicle. Roux staining was low, and partial vascular and cellular infiltration was observed, although it was not marked.

CONCLUSION

The herniated nucleus pulposus involving endplate cartilage from C4-C5 was limited to the superficial layer, and proliferation of nucleus pulposus-like chondrocytes occurred in the herniated tissue, where they might undergo a change in cell phenotype. The results of the present study support the hypothesis that hypertrophy of the posterior longitudinal ligament is a prodromal condition to ossification of the posterior longitudinal ligament.

Removal of soluble selenium by a selenate-reducing bacterium Bacillus sp. SF-1

In order to develop a biological process for removal of selenium from industrial wastewater, Bacillus sp. strain SF-1 was isolated from selenium-contaminated sediment. The bacterium reduces selenate to selenite and subsequently to nontoxic insoluble elemental selenium using lactate as an electron donor and selenate as an electron acceptor in an anaerobic condition. Elemental selenium transformed from soluble selenium was deposited both inside and outside of the cells. Since the selenate reduction rate of the strain SF-1 was higher than the selenite reduction rate, selenite was transiently accumulated. In an experiment of the repeated soluble selenium reduction by strain SF-1, 0.5 mM of selenate was sequentially treatable with a cycle of one day. Thus, our sequential system for removal of soluble selenium is very useful.

Design and synthesis of 3?-helix peptides forming a cavity for a fluorescent ligand

As a model of receptor protein, a series of 3alpha-helix bundle peptides constructed on a template peptide were designed so as to possess a hydrophobic cavity. The size of cavity was modulated by simple replacements of Leu residues to Ala residues in the hydrophobic core. Binding abilities to 8-anilino-1-naphthalenesulfonic acid (ANS) were estimated by the increase of fluorescence intensity. The peptide having three or four Ala residues in the hydrophobic core remarkably increased the binding ability for ANS, though the peptide having two Ala residues gave an inefficient cavity for ANS. The peptide having six Ala residues decreased the binding ability due to crucial destabilization of the helix bundle structure. This scaffold can be utilized to a receptor model, while further tuning of the sequence is necessary.

Photoinduced hydrogen evolution with peptide dendrimer-multi-Zn(II)-porphyrin, viologen, and hydrogenase

To construct an artificial photosynthetic system, multi-Zn(II)-mesoporphyrins in peptide dendrimers were equipped as a photosensitizer of photoinduced hydrogen evolution in a four-component system (electron donor, photosensitizer, electron carrier, and catalyst), so that hydrogen was evolved effectively by the dendrimer architecture, for the first time. The hydrogen evolution activity was correlated to the photoreduction ability of viologen by the Zn-porphyrin-peptide dendrimers. Additionally, using positively charged methyl-viologen as an electron carrier, the photoinduced hydrogen evolution function with the positively charged peptide dendrimer was superior to that with the negatively charged peptide dendrimer, despite that the positive dendrimer did not strongly bind the positively charged methyl-viologen with the electrostatic interaction. By contrast, when zwitterionic propylviologen sulfonate was used, photoreduction and hydrogen evolution properties were identical between the positively and the negatively charged dendrimers. These results demonstrated that the dynamic interaction between the positive dendrimer and methyl-viologen was preferable for the photoreduction and hydrogen evolution, and that the three-dimensional assembly of Zn(II)-mesoporphyrins using the peptide dendrimers was effective as a photosensitizer in the artificial photosynthesis.

Design, synthesis and peroxidase-like activity of 3alpha-helix proteins covalently bound to heme

As a model of artificial peroxidase, de novo designed three-alpha-helix proteins, 3alpha-H9 and 3alpha-H12, covalently bound to Fe(III)-mesoporphyrin IX were synthesized and examined for a peroxidase-like activity. The activity was regulated according to the positions of His residues in the proteins, and the His residues played a role in an acid-base catalytic function.

Gene cloning, purification, and characterization of two cyanobacterial NifS homologs driving iron-sulfur cluster formation

Iron-sulfur proteins are essential in the photosynthetic system and many other biological processes. We have isolated and characterized enzymes driving the formation of iron-sulfur clusters from Synechocystis sp. PCC6803. Two genes (slr0387 and sll0704), showing similarity to nifS of Azotobacter vinelandii, were cloned, and their gene products (SsCsdl and SsCsd2) were purified. They catalyzed the desulfuration of L-cysteine. Reconstitution of a [2Fe-2S] cluster of cyanobacterial ferredoxin proceeded much faster in the presence of L-cysteine and either of these enzymes than when using sodium sulfide. These results suggest that SsCsdl and SsCsd2 facilitate the iron-sulfur cluster assembly by producing inorganic sulfur from L-cysteine. Synechocystis sp. PCC6803 has no gene coding for a protein with similarity to the N-terminal domain of NifU of A. vinelandii, which is believed to cooperate with NifS to assemble iron-sulfur clusters. Thus, the cluster formation in the cyanobacterium probably proceeds through a mechanism that is different from that in A. vinelandii.

Construction of two-stranded alpha-helix peptides based on influenza virus M1 protein selectively bound to RNA

Various 2alpha-helix peptides were designed and synthesized based on the RNA-binding region of matrix protein M1 in influenza virus. The binding properties of the peptides to model ssRNA, ssDNA, dsDNA, and virus RNA were examined by the fluorescence studies of a dansyl group incorporated into the peptides. The peptide containing the hydrophilic residues of M1 RNA-binding region bound RNAs selectively.

Mutational analysis of designed peptides that undergo structural transition from alpha helix to beta sheet and amyloid fibril formation

BACKGROUND

Conformational alteration and fibril formation of proteins have a key role in a variety of amyloid diseases. A simplified model peptide would lead to a better understanding of underlying mechanisms whereby protein misfolding and aggregation occur. Recently, we reported the design of peptides that undergo a self-initiated structural transition from an alpha helix to a beta sheet and form amyloid fibrils. In this study, we focus on two glutamine residues in the peptide, and report a mutational analysis of these residues.

RESULTS

A coiled-coil alpha-helix structure bearing a hydrophobic adamantanecarbonyl (Ad) group at the N terminus was designed (parent peptide Ad-QQ). In neutral aqueous solution, the double Gln-->Ala mutant (Ad-AA) underwent the alpha-->beta structural transition within four hours, which was similar to the case of Ad-QQ. In contrast, two kinds of single Gln-->Ala mutant (Ad-QA and Ad-AQ) required three days for the transition. Furthermore, Ad-QQ and Ad-AA formed amyloid fibrils, whereas Ad-QA and Ad-AQ did not. Interestingly, however, Ad-QA and Ad-AQ complementarily assembled into the fibrils when they were mixed.

CONCLUSIONS

The Gln-->Ala substitution in the peptide significantly alters the alpha-->beta transitional properties and the ability to form amyloid fibrils. A heterogeneous assembly of two peptide species into the fibrils is also presented. These results suggest that the secondary structural transition and self-assembly into the well-organized fibril may depend strictly on the primary structure, which determines the beta-sheet packing. The results might provide insights into misfolding and fibril formation of disease-associated mutant proteins.

Peptide design based on an antibody complementarity-determining region (CDR): construction of porphyrin-binding peptides and their affinity maturation by a combinatorial method

We have utilized sequence information from an antiheme monoclonal antibody to develop novel porphyrin-binding peptides. Several peptides which have an intramolecular disulfide bond in different positions and different chain lengths were prepared. The affinities of peptides for meso-tetrakis(4-carboxyphenyl)porphyrin were increased by an appropriate conformational restraint using a disulfide bond. Detailed studies with a representative 12-peptide, 12C4, whose length was reduced from 20 residues of the complementarity-determining region (CDR), indicated that both the hydrophobic and electrostatic interactions were essential factors in the peptide-porphyrin binding. Moreover, two-dimensional 1H NMR spectroscopy revealed the conformation of the peptide and the critical residues for the porphyrin-binding. According to the obtained results, a further minimized 9-peptide, 9L, was successfully redesigned with a sequence capable of forming a beta-turn instead of a disulfide bond. Furthermore, affinity maturation studies of 9L were performed by using a combinatorial approach such as the spot-synthesis method. Peptides with an improved affinity for porphyrins were prepared by systematic amino acid replacement. Thus, the design of peptides targeted to porphyrins was demonstrated by the combination of antibody information and the rationally designed combinatorial method.