RESUMO
In order to better understand the relationship between dopamine and the release of diapause hormone into the blood, we cloned and characterized cDNAs encoding Bombyx mori dopamine receptor-1 and -2 (BmDopR1 and 2) from the pupal brain-suboesophageal ganglion. BmDopR1 and 2 had high similarities to group 1 (Drosophila melanogaster DOP1 and Apis mellifera DOP1) and group 2 (D. melanogaster DopR99B, A. mellifera DOP2 and Papilio xuthus DOP1), respectively. When BmDopR1 and 2 were expressed in human embryonic kidney (HEK) cells, they responded to dopamine by increasing intracellular cAMP levels, thus indicating the presence of D1-like receptors. There were no clear differences in BmDopR1 and 2 mRNA levels between brain-suboesophageal ganglion complexes of diapause and nondiapause egg producers during pupal-adult development. BmDopR1 and 2 mRNAs were concentrated in the mushroom body calyx rather than in the suboesophageal ganglion. Taking into account the results of earlier experiments on excised regions corresponding to mushroom bodies, BmDopR1 and 2 in the mushroom body apparently play a role in the release of diapause hormone.
Assuntos
Bombyx/genética , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/metabolismo , Linhagem Celular , Clonagem Molecular , DNA Complementar/genética , Feminino , Gânglios dos Invertebrados/química , Gânglios dos Invertebrados/metabolismo , Humanos , Hibridização In Situ , Dados de Sequência Molecular , Neuropeptídeos/fisiologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , TransfecçãoRESUMO
Low- and non-leucite-containing commercial porcelains with low firing temperatures have become popular. However, improving the strength of glass porcelains is difficult. The purpose of this study was to determine if dispersed glass particles could be used as a reinforcing agent for an all-glass porcelain. We produced 3 feldspathic glasses (high-fusing, medium-fusing, low-fusing) by melting powders consisting of potassium-feldspar and 0, 5, or 20 mass% Na2O, respectively. For high-fusing, medium-fusing, and low-fusing feldspathic glasses, the deformation temperatures were 945 degrees C, 647 degrees C, and 518 degrees C, and the thermal expansion coefficient values were 8.6 x 10(-6)/degrees C, 10.3 x 10(-6)/degrees C, and 13.4 x 10(-6)/degrees C between 25 degrees C and the glass-transition temperature, respectively. The high-fusing-glass (or medium-fusing-glass) powders were mixed with low-fusing-glass powders before being fired into test specimens. The mean flexural strength and fracture toughness (K1C) of 3 single-glass porcelains ranged from 57 to 63 MPa and from 0.68 to 0.73 MPa m(1/2), respectively, presenting no significant differences in one-way ANOVA. However, the flexural strength of 50% high-fusing-glass + 50% low-fusing-glass porcelain was 114 MPa (p < 0.05) and K1C was 1.2 MPa m(1/2) (p < 0.05). Microcracks were observed with a back-scattered scanning electron microscope and were associated with the high- (or medium-) fusing glass particles, suggesting residual stress in the low-fusing-glass matrix due to a coefficient of thermal expansion mismatch between the dispersed glass particles and the matrix glass. The dispersing glass particles appeared to act as a reinforcing agent for strengthening a glassy porcelain.
Assuntos
Silicatos de Alumínio/química , Porcelana Dentária/química , Vidro/química , Compostos de Potássio/química , Análise de Variância , Temperatura Alta , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Óxidos/química , Maleabilidade , Potássio/química , Pós , Compostos de Sódio/química , Estresse Mecânico , Propriedades de Superfície , TermodinâmicaRESUMO
Superelastic Ni-Ti wire is widely used in orthodontic clinics, but delayed fracture in the oral cavity has been observed. Because hydrogen embrittlement is known to cause damage to Ti alloy systems, orthodontic wires were charged with hydrogen using an electro-chemical system in saline. Tensile tests were carried out, and fracture surfaces were observed after hydrogen charging. The strength of the Co-Cr alloy and stainless steel used in orthodontic treatment, was not affected by the hydrogen charging. However, Ni-Ti wire showed significant decreases in strength. The critical stress of martensite transformation was increased with increasing hydrogen charging, and the alloy was embrittled. The fractured surface of the alloys with severe hydrogen charging exhibited dimple patterns similar to those in the alloys from patients. In view of the galvanic current in the mouth, the fracture of the Ni-Ti alloys might be attributed to the degradation of the mechanical properties due to hydrogen absorption.
Assuntos
Níquel , Fios Ortodônticos/efeitos adversos , Titânio , Absorção , Ligas/farmacocinética , Biodegradação Ambiental , Elasticidade , Eletroquímica , Humanos , Hidrogênio , Técnicas In Vitro , Teste de Materiais , Boca/metabolismo , Níquel/farmacocinética , Propriedades de Superfície , Resistência à Tração , Titânio/farmacocinéticaRESUMO
We developed a new high-performance liquid chromatographic method using an ODS column and a chiral column for the assay of racemic 4-OH-PL sulfate and enantiomeric 4-OH-PL sulfates, respectively. The method was successfully applied to measure phenolsulfotransferase (PST) activities for 4-OH-PL in cytosolic fractions from livers of Japanese monkeys (Macaca fuscata) and for comparison with its activity of cytosolic fractions from rat, rabbit, dog, and human livers and Hep G2 cells. The activity was ranked as Hep G2 cells > monkeys = humans = dogs = rats > rabbits. To evaluate the Japanese monkey as a nonhuman animal model in drug metabolism studies, we further characterized sulfation of 4-OH-PL as a further metabolic pathway in monkey livers to compare that with human livers. Inhibition studies in which cytosolic fractions were preincubated at 43 degrees C or 2,6-dichloro-4-nitrophenol (DCNP) used as a PST inhibitor indicated that two kinds of PSTs, thermolabile, low-Km and DCNP-resistant PST and thermostable, high-Km and DCNP-sensitive PST were involved in 4-OH-PL sulfation by monkey liver cytosol, which is very similar to the reported profile of 4-OH-PL sulfation by human liver cytosol. Sulfation kinetics in a low concentration range of 4-OH-PL enantiomers demonstrated that apparent Km values were similar between human and monkey liver cytosolic fractions, but the Vmax values were different, so that intrinsic clearance values (Vmax/Km, Clint) were higher in monkeys than in humans. Furthermore, enantiomer selectivity of [R(+)-4-OH-PL > S(-)-4-OH-PL] was observed in the Vmax and CLint values of monkey liver cytosol. These results indicate that the profile of sulfation of 4-OH-PL by liver cytosolic fractions is similar in humans and Japanese monkeys.
Assuntos
Fígado/metabolismo , Propranolol/análogos & derivados , Propranolol/metabolismo , Sulfatos/metabolismo , Adulto , Idoso , Animais , Arilsulfotransferase/metabolismo , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Citosol/enzimologia , Citosol/metabolismo , Cães , Humanos , Cinética , Fígado/enzimologia , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/metabolismo , Macaca , Masculino , Pessoa de Meia-Idade , Coelhos , Ratos , Ratos Wistar , Especificidade da Espécie , Estereoisomerismo , Células Tumorais CultivadasRESUMO
The purpose of this study was to determine if short fibres of CaO-P2O5-SiO2-Al2O3 (CPSA) glass possessing a particular aspect ratio (length/diameter) could be used as a reinforcing agent for glass-ionomer cement. The powder of a commercial glass-ionomer cement (not resin modified) was mixed with variously sized CPSA glass short fibres before mixing with the liquid of the glass-ionomer cement. The mixed powders containing 60 mass% CPSA glass short fibres (diameter, 9.7 +/- 2.1 microm, aspect ratio, 5.0 +/- 0.9) obtained maximum values of 18 and 35 MPa for the diametral tensile strength (DTS) and flexural strength (FS) of set cements, respectively, after 24 h. These DTS and FS values were 1.8 and 4.5 times larger, respectively, than those of the set glass-ionomer cement not containing short fibres. Moreover, it was found that the addition of CPSA glass short fibres was remarkably more effective in the strengthening than electric glass (a typical glass fibre) short fibres. The results suggested that the CPSA glass short fibres acted as a reinforcing agent for strengthening the glass-ionomer cement, because of the shape of short fibres and reactivity between the mixing liquid and short fibres.
Assuntos
Cimentos Dentários/química , Vidro/química , Microscopia Eletrônica de VarreduraRESUMO
We examined and compared enantioselectivity in the oxidation of propranolol (PL) by liver microsomes from humans and Japanese monkeys (Macaca fuscata). PL was oxidized at the naphthalene ring to 4-hydroxypropranolol, 5-hydroxypropranolol and side chain N-desisopropylpropranolol by human liver microsomes with enantioselectivity of [R(+)>S(-)] in PL oxidation rates at substrate concentrations of 10 microM and 1 mM. In contrast, reversed enantioselectivity [R(+)
Assuntos
Citocromo P-450 CYP2D6/metabolismo
, Microssomos Hepáticos/enzimologia
, Propranolol/química
, Propranolol/metabolismo
, Estereoisomerismo
, Animais
, Baculoviridae/genética
, Citocromo P-450 CYP2D6/genética
, Humanos
, Hidroxilação
, Cinética
, Macaca
, Oxirredução
, Proteínas Recombinantes/metabolismo
, Especificidade da Espécie
, Spodoptera/metabolismo
, Especificidade por Substrato
, Transfecção
RESUMO
OBJECT: Recombinant adenovirus is used as a competent vector in a wide spectrum of cancer gene therapies because of its high efficiency in gene delivery. To study the feasibility of gene therapy in malignant gliomas, the authors examined the antiproliferative effect of the adenovirally transduced wild-type p53 tumor suppressor gene by using 15 different high-grade glioma cell lines. METHODS: Although growth suppression in association with a high adenoviral p53 transduction efficiency was seen in five of 15 cell lines, it was not observed in the remaining 10 cell lines. To clarify the underlying mechanism, we examined the expression levels of the Coxsackievirus and adenovirus receptor (CAR), which is the primary receptor for adenovirus, and of the integrins alpha vbeta3 and alpha vbeta5, which promote adenoviral internalization. The expression level of the CAR gene showed a close correlation to adenoviral gene transduction efficiency in the tested cell lines, whereas the expression levels of the integrins did not. The CAR expression was decreased by wild-type p53 transduction in U251MG cells harboring mutant p53 and increased by antisense inhibition of p53 in LN443 cells with endogenous wild-type p53. CONCLUSIONS: The results of this study indicate that CAR expression is a critical determinant of transduction efficiencies in adenovirus-based gene therapy for human malignant gliomas.
Assuntos
Adenoviridae/genética , Expressão Gênica , Técnicas de Transferência de Genes , Glioma/genética , Receptores Virais/genética , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , Glioma/metabolismo , Humanos , Integrinas/genética , RNA Mensageiro/metabolismo , Receptores de Vitronectina/genética , Transfecção , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Sawa-J, CSJ02 and N601 x C601 are selected mutant strains of Bombyx mori, which grow on various artificial diets or temporarily ingest various plant leaves. To examine the mechanisms mediating diet breadth of caterpillars, gustatory spike responses of the silkworms, called 'polyphagous" strains, were compared with normal strains, N137 x C146 and C02. There were notable differences in their feeding habits and in their sensitivity to salicin in deterrent cells in the maxillary medial styloconic sensilla and the epipharyngeal sensilla. By contrast, the deterrent cells of all strains responded similarly to strychnine nitrate in a dose-dependent manner. In additional comparisons of Sawa-J and N137 x C146, Sawa-J maxillary deterrent cells were significantly less sensitive to phloridzin, amygdalin and arbutin, but responded to some alkaloids and 20-hydroxyecdysone with similar or even higher firing rate. These results suggest that the deficiency of the sensitivity to some deterrent compounds on the deterrent cell of the polyphagous strains may be caused by mutant genes and affects the diet breadth of caterpillars.
Assuntos
Bombyx/fisiologia , Mutação/fisiologia , Paladar/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Alcaloides/farmacologia , Animais , Álcoois Benzílicos/farmacologia , Bombyx/genética , Relação Dose-Resposta a Droga , Glucosídeos , Valores de Referência , Órgãos dos Sentidos/citologia , Órgãos dos Sentidos/efeitos dos fármacos , Órgãos dos Sentidos/fisiologia , Estimulação Química , Estricnina/farmacologiaRESUMO
OBJECT: The sealing properties of fibrin sealant with high concentrated fibrin (fibrin patch) were examined. MATERIAL AND METHODS: A commercial fibrin sealant (Bolheal) produced from pooled human plasma was utilized for this study. The fibrin sealant made of fibrinogen and thrombin solutions mixed in a volume ratio 5:1 was applied as the fibrin sealant with high concentrated fibrin (fibrin patch). The burst pressure of the fibrin clots of either 1:1 or 5:1 mixing ratio, which sealed the small holes, was measured by a water-leak preventing model. The tensile strength of the fibrin patch was measured by the breaking pressure of the fibrin clot. The burst pressure of the fibrin patch, which sealed the dural defect with a diameter of 15 mm, was compared with that of expanded polytetrafluoroethylene (ePTFE). RESULTS: The burst pressure was elevated from 287 +/- 23.1 to 445 +/- 30.5 mmHg by changing the mixing ratio from 1:1 to 5:1. The breaking pressure of the fibrin patch showed 131 +/- 25.4 mmHg and that of the patch mixed at the ratio of 1:1 showed 46.6 +/- 9.9 mmHg. The result of dural repair with the fibrin patch revealed higher sealing effectiveness than that of ePTFE. The burst pressure averaged 70.5 +/- 21.4 mmHg in the fibrin patch samples and 51.4 +/- 13 mmHg in the ePTFE samples. CONCLUSION: The fibrin patch revealed higher performance as a sealant and has the potential to be a candidate for acceptance as the new dural repair material.
Assuntos
Adesivo Tecidual de Fibrina/normas , Politetrafluoretileno/normas , Encéfalo/cirurgia , Estudos de Avaliação como Assunto , Fibrina/química , Humanos , Resistência à TraçãoRESUMO
Thermocycling and water storage effects on fracture toughness (KIC) of chemically or thermally tempered metal-ceramic disks were investigated to evaluate the durability of tempering effects with regard to oral aqueous environment. Metal-ceramic disks (phi 10 mm x 2.0 mm) consisting of opaque porcelain (0.2 mm thick), body porcelain (1.3 mm) and Ni-Cr-Be alloy (0.5 mm) were prepared and the porcelain surfaces were polished with 1-micron diamond paste. The disks were subjected to ion exchange (potassium or rubidium) or thermal tempering treatments, then with the as-polished or further annealed disks, thermocycled for 8000, 15,000, and 22,000 cycles between 5 degrees C and 60 degrees C or stored in water at 37 degrees C for 33 days. After aging, KIC values of disks were determined by a Vickers indentation technique. Statistical analyses indicated that the KIC values of ion-exchanged and annealed disks were not significantly affected by the limited number of cycles and water storage, while the thermally tempered and untreated disks revealed a significant decrease in mean KIC from even 8000 cycles and after storage. However, there was no significant difference between thermocycling and water-storage effects on mean KIC of all surface treatment groups. Results indicate that chemical tempering (ion exchange) produced more durable residual stresses than does thermal tempering for metal-ceramic restorations. A low-thermal load only was unlikely to affect the apparent fracture toughness of porcelain.
Assuntos
Porcelana Dentária , Temperatura Alta , Teste de Materiais , Ligas Metalo-Cerâmicas/química , Ligas de Cromo/química , Falha de Equipamento , Análise de Falha de Equipamento , Troca Iônica , Metais/química , Microscopia Eletrônica de Varredura , Modelos Teóricos , Estresse Mecânico , Propriedades de Superfície , Água/químicaRESUMO
The current density of Ti-56mass%Ni (Ti-50at.%) alloy after abrasion in simulated bioliquids was measured using a potentiostat to estimate the amount of metallic ions released from the alloy during repassivation and maturation. The current density in saline, saline with and without N2 bubbling, and Hanks' solutions with and without proteins after abrasion was measured and the amount of released ion was calculated from the integrated current density with time, assuming that Ti4+ and Ni2+ are equivalently released. No difference in the amount of released ion was observed between saline with and without N2 bubbling. Also, no difference was observed between saline and pH 7.4 Hanks' solution. More Ti4+ and Ni2+ were released in bioliquids with proteins than in saline with and without N2 bubbling (p < 0.05). That is, dissolved oxygen and inorganic ions in Hanks' solution did not influence the amount of released ion, but proteins influenced it. The release of metallic ions from metals and alloys in biological systems can be estimated by the methodology employed in this study.
Assuntos
Ligas/química , Materiais Biocompatíveis , Teste de Materiais , Níquel/química , Titânio/química , Íons Pesados , Concentração de Íons de Hidrogênio , Modelos Químicos , Nitrogênio/química , Oxigênio/química , Cloreto de Sódio/química , Soluções/química , Propriedades de SuperfícieAssuntos
Orelha Externa/inervação , Nervo Facial/cirurgia , Paralisia Facial/cirurgia , Nervo Hipoglosso/cirurgia , Nervos Periféricos/transplante , Procedimentos de Cirurgia Plástica , Anastomose Cirúrgica , Humanos , Procedimentos Neurocirúrgicos/métodos , Procedimentos de Cirurgia Plástica/métodosRESUMO
TRF (terminal restriction fragments) length in various tissues of non-human primates such as Macaca mulatta (rhesus monkey), Macaca fuscata (Japanese monkey), Macaca fascicularis (crab-eating monkey), Pan troglodytes (common chimpanzee), and Pongo pygmaeus (orangutan) was at least 23 kb without exception, which was quite different from that of human somatic tissues (smaller than 10 kb). The distribution pattern of telomerase activity among tissues was similar between human and non-human primates, while the activity level showed some differences such as that strong telomerase activity was observed in gastrointestinal and lymphocytic tissues from non-human primates. The human appears to be a unique species among primates in terms of telomere length.
Assuntos
Hominidae/genética , Macaca/genética , Telômero , Envelhecimento/genética , Animais , Senescência Celular/genética , Enzimas de Restrição do DNA , Feminino , Humanos , Masculino , Pan troglodytes/genética , Pongo pygmaeus/genética , Telomerase/análise , Distribuição TecidualRESUMO
Many compounds that taste bitter to humans also inhibit feeding in insects. Caterpillars (e.g., Manduca sexta) detect these compounds with a few bitter-sensitive taste cells. This study examined the role of these taste cells in feeding inhibition. Behavioral studies demonstrated that 3 bitter compounds (caffeine, salicin, and aristolochic acid) all inhibited feeding rapidly in Manduca sexta. Electrophysiological studies revealed that each pair of bitter-sensitive taste cell differs in responsiveness to the bitter compounds. Ablation studies indicated that (a) those pairs of bitter-sensitive taste cells that responded vigorously to a particular bitter compound were sufficient to inhibit feeding on diets containing the same compound, but that (b) no pair of bitter-sensitive taste cells was necessary for inhibiting feeding. Thus, the different pairs of bitter-sensitive taste cells appear to make partially redundant contributions to feeding inhibition.
Assuntos
Comportamento Alimentar/fisiologia , Inibição Psicológica , Manduca/fisiologia , Paladar/fisiologia , Animais , Fenômenos Fisiológicos Celulares , InsetosRESUMO
We report a case of stage IV ovarian clear cell adenocarcinoma successfully controlled by a combination of cisplatin-cyclophosphamide (CP) and paclitaxel-carboplatin (TJ). A 64-year-old female with advanced ovarian cancer and pleural effusion underwent 4 courses of combination chemotherapy with CP. The giant ovarian tumor showed a relative reduction in size and the pleural effusion disappeared. Serum CA-125 levels and CA 19-9 levels markedly decreased. Thus, the patient underwent a total hysterectomy and bilateral salphingoophorectomy. During the operation, a giant ovarian clear cell adenocarcinoma was found, but there was no peritoneal dissemination and no cancer cells in her peritoneal fluid. Thereafter, she underwent 3 courses of combination chemotherapy with TJ. She has had 13 months of stable, tumor-free survival since the operation and normal serum CA-125 and CA 19-9 levels. Ovarian clear cell adenocarcinoma generally responds poorly to cisplatin and carboplatin, but in combination chemotherapy with paclitaxel-carboplatin these may be effective.
Assuntos
Adenocarcinoma de Células Claras/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Carboplatina/administração & dosagem , Cisplatino/administração & dosagem , Ciclofosfamida/administração & dosagem , Esquema de Medicação , Feminino , Humanos , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Derrame Pleural Maligno/tratamento farmacológico , Indução de RemissãoRESUMO
OBJECTIVE AND IMPORTANCE: Oculomotor schwannoma is extremely rare. We report a case of oculomotor schwannoma with consideration of its surgical management. CLINICAL PRESENTATION: A 64-year-old woman with a history of chronic headache underwent a computed tomographic scan, which revealed a mass lesion in the right prepontine cistern. She had no neurological deficits at admission. INTERVENTION: The tumor originated from the right oculomotor nerve. It was subtotally removed, leaving a tiny part attached to the nerve. The nerve trunk was preserved. A pathological examination revealed a schwannoma. Transient right oculomotor nerve palsy occurred postoperatively, but it improved almost completely. CONCLUSION: The tumor in the present case was resected, preserving serviceable oculomotor function. However, among 16 patients reported in the literature, all but one developed or maintained severe postsurgical oculomotor nerve palsy. We conclude that surgical resection generally is not indicated for oculomotor schwannomas, excluding large tumors that cause intractable symptoms.
Assuntos
Neoplasias dos Nervos Cranianos/diagnóstico , Neoplasias dos Nervos Cranianos/cirurgia , Neurilemoma/diagnóstico , Neurilemoma/cirurgia , Doenças do Nervo Oculomotor/diagnóstico , Doenças do Nervo Oculomotor/cirurgia , Neoplasias dos Nervos Cranianos/patologia , Craniotomia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Neurilemoma/patologia , Nervo Oculomotor/diagnóstico por imagem , Nervo Oculomotor/patologia , Doenças do Nervo Oculomotor/patologia , Tomografia Computadorizada por Raios XRESUMO
OBJECT: In this study the authors investigated the histomorphometric background and microsurgical anatomy associated with surgically created direct hypoglossal-facial nerve side-to-end communication or nerve "anastomosis." METHODS: Histomorphometric analyses of the facial and hypoglossal nerves were performed using 24 cadaveric specimens and three surgically obtained specimens of severed facial nerve. Both the hypoglossal nerve at the level of the atlas and the facial nerve just distal to the external genu were monofascicular. The number of myelinated axons in the facial nerve (7228 +/- 950) was 73.2% of those in the normal hypoglossal nerve (9778 +/- 1516). Myelinated fibers in injured facial nerves were remarkably decreased in number. The cross-sectioned area of the normal facial nerve (0.948 mm2) accounted for 61.5% of the area of the hypoglossal nerve (1.541 mm2), whereas that of the injured facial nerve (0.66 mm2) was less than 50% of the area of the hypoglossal nerve. Surgical dissection and morphometric measurements were performed using 18 sides of 11 adult cadaver heads. The length of the facial nerve from the pes anserinus to the external genu ranged from 22 to 42 mm (mean 30.5 +/- 4.4 mm). The distance from the pes anserinus to the nearest point on the hypoglossal nerve ranged from 14 to 22 mm (mean 17.3 +/- 2.5 mm). The former was always longer than the latter; the excess ranged from 6 to 20 mm (mean 13.1 +/- 3.4 mm). Surgical anatomy and procedures used to accomplish the nerve connection are described. CONCLUSIONS: The size of a half-cut end of the hypoglossal nerve matches a cut end of the injured facial nerve very well. By using the technique described, a length of facial nerve sufficient to achieve a tensionless communication can consistently be obtained.