Persistent magnetic coherence in magnets.

When excited, the magnetization in a magnet precesses around the field in an anticlockwise manner on a timescale governed by viscous magnetization damping, after which any information carried by the initial actuation seems to be lost. This damping appears to be a fundamental bottleneck for the use of magnets in information processing. However, here we demonstrate the recall of the magnetization-precession phase after times that exceed the damping timescale by two orders of magnitude using dedicated two-colour microwave pump-probe experiments for a Y3Fe5O12 microstructured film. Time-resolved magnetization state tomography confirms the persistent magnetic coherence by revealing a double-exponential decay of magnetization correlation. We attribute persistent magnetic coherence to a feedback effect, that is, coherent coupling of the uniform precession with long-lived excitations at the minima of the spin-wave dispersion relation. Our finding liberates magnetic systems from the strong damping in nanostructures that has limited their use in coherent information storage and processing.

COVID-19 transmission in dental and oral/maxillofacial surgical practice during pandemic: questionnaire survey in 51 university hospitals in Japan.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has become a major public health problem. Dental procedures that generate aerosols are considered to impose a high risk of infection; therefore, dental professionals, such as dentists and dental hygienists, may be at high risk of viral transmission. However, few studies have reported COVID-19 clusters in dental care settings. AIM: To investigate whether dental and oral/maxillofacial procedures are associated with the occurrence of COVID-19 clusters and measures taken to prevent nosocomial infection in dental clinics. METHODS: An online questionnaire survey on clinical activities (administrative control), infection control measures (environmental/engineering control, personal protective equipment, etc.), and confirmed or probable COVID-19 cases among patients and clinical staff was administered to the faculties of the dental and oral/maxillofacial surgical departments of university hospitals. FINDINGS: Fifty-one faculty members completed the questionnaire. All members were engaged in the treatment of dental and oral surgical outpatients and actively implemented standard precautions. Fourteen faculty members treated patients with COVID-19, but no infections transmitted from the patients to the medical staff were observed. In seven facilities, patients were found to have the infection after treatment (medical staff came in close contact), but there was no transmission from patients to medical staff. Four facilities had medical staff with infections, but none of them exhibited disease transmission from staff to patients. CONCLUSION: COVID-19 clusters are unlikely to occur in dental and oral surgical care settings if appropriate protective measures are implemented.

Direct renal pelvicocystostomy using tube cystoplasty in a cat with ureteral obstruction.

We describe a surgical technique to re-establish urine flow in a 3-year-old Scottish Fold cat. A ureteral stent and subcutaneous urinary bypass failed after their placement due to rapid mineralisation of the lumen. Direct pelvicocystostomy anastomosis using a modified tube cystoplasty technique was performed. A wide rectangular apex-based full-thickness flap was created from the ventral aspect of the urinary bladder, which was sutured longitudinally to form a large-diameter tube. The resulting tube-shaped portion of the bladder was then directly anastomosed to the renal pelvis. No major postoperative complications were observed and no further recurrence of obstruction of the upper urinary tract was noted during follow-up. The cat died at home 481 days postoperatively from an undetermined cause. A pelvicocystostomy technique can be considered as an alternative salvage surgical technique for obstructive ureteral disease in cats.

Spin/orbital and magnetic quantum number selective magnetization measurements for CoFeB/MgO multilayer films.

Spin selective magnetic hysteresis (SSMH) curves, orbital selective magnetic hysteresis (OSMH) curves and magnetic quantum number selective SSMH curves are obtained for CoFeB/MgO multilayer films by combining magnetic Compton profile measurements and superconducting quantum interference device (SQUID) magnetometer measurements. Although the SQUID magnetometer measurements do not show perpendicular magnetic anisotropy (PMA) in the CoFeB/MgO multilayer film, PMA behavior is observed in the OSMH and SSMH curves for the |m| = 2 magnetic quantum number states. These facts indicate that magnetization switching behavior is dominated by the orbital magnetization of the |m| = 2 magnetic quantum number states.

Production of three-dimensional tissue-engineered cartilage through mutual fusion of chondrocyte pellets.

In this study, the mutual fusion of chondrocyte pellets was promoted in order to produce large-sized tissue-engineered cartilage with a three-dimensional (3D) shape. Five pellets of human auricular chondrocytes were first prepared, which were then incubated in an agarose mold. After 3 weeks of culture in matrix production-promoting medium under 5.78g/cm(2) compression, the tissue-engineered cartilage showed a sufficient mechanical strength. To confirm the usefulness of these methods, a transplantation experiment was performed using beagles. Tissue-engineered cartilage prepared with 50 pellets of beagle chondrocytes was transplanted subcutaneously into the cell-donor dog for 2 months. The tissue-engineered cartilage of the beagles maintained a rod-like shape, even after harvest. Histology showed fair cartilage regeneration. Furthermore, 20 pellets were made and placed on a beta-tricalcium phosphate prism, and this was then incubated within the agarose mold for 3 weeks. The construct was transplanted into a bone/cartilage defect in the cell-donor beagle. After 2 months, bone and cartilage regeneration was identified on micro-computed tomography and magnetic resonance imaging. This approach involving the fusion of small pellets into a large structure enabled the production of 3D tissue-engineered cartilage that was close to physiological cartilage tissue in property, without conventional polyper scaffolds.

Reduced preoperative serum albumin and absence of peritoneal dissemination may be predictive factors for long-term survival with advanced gastric cancer with positive cytology test.

BACKGROUND: Peritoneal lavage cytology cancer-positive (CY1) is a critical prognostic factor and is taken as representing stage IV in gastric cancer. There is no consensus treatment strategy for CY1-gastric cancer, and the detailed clinicopathological features remain obscure. PATIENTS AND METHODS: Among 790 gastric cancer patients between 2005 and 2009, 52 cases of CY1 were identified (6.6%). A multivariate prognostic model was applied to the univariate prognostic factors to identify independent prognostic factors and factors associated with long-term survival in CY1-gastric cancer. RESULTS: (1) Five-year overall survival (OS) was 17.6% in CY1-gastric cancer as compared with 93.9% in CYX and 77.7% in CY0 (77.7%), where tumors with pT2 or beyond were included in 11% of CYX, 73% of CY0, and 98% of CY1 cases. (2) On univariate analysis, factors associated with a negative prognosis were the presence of peritoneal dissemination (p = 0.029) and high preoperative serum albumin (p = 0.011) in CY1-gastric cancer. The multivariate Cox proportional hazards and logistic regression model using propensity score identified preoperative albumin as a critical independent prognostic indicator. (3) Long-term survivors were identified and, were often characterized by long-term postoperative adjuvant treatment. CONCLUSION: Reduced preoperative serum albumin and absence of peritoneal dissemination may be predictive factors for long-term survival in patients with advanced gastric cancer with positive cytology test. Long-term postoperative adjuvant therapy might improve survival of patients with CY1.

Early detection of ovarian and fallopian tube cancer by examination of cytological samples from the endometrial cavity.

BACKGROUND: Accumulating evidence suggests that many ovarian high-grade serous carcinomas (HGSCs) originate in the fallopian tube. Malignant cells shed by tubal lesions can be detected by examination of cytological samples from the endometrial cavity (endometrial cytological testing). To evaluate the use of this method for detecting HGSC, we examined epithelial ovarian, fallopian tube, and primary peritoneal cancer patients. METHODS: Endometrial cytological testing was performed for endometrial cancer screening in asymptomatic women and for pre-treatment evaluation in symptomatic suspected ovarian, tubal, and peritoneal cancer patients. RESULTS: Of the 122 ovarian, tubal, and peritoneal cancer patients, malignant cells were identified in 5 patients who did not show detectable abnormalities on imaging studies. Cervicovaginal cytology was positive in only one of these five patients. Four patients were asymptomatic and one was symptomatic. Three asymptomatic patients had early-stage HGSCs, and the other asymptomatic patient had positive peritoneal cytology findings but no detectable tumour. HGSC patients were significantly more likely to have positive findings on endometrial cytology than patients with other histological types (23% vs 6%, P=0.02). CONCLUSION: Endometrial cytological testing can detect early-stage ovarian, tubal, and peritoneal HGSCs without detectable pelvic masses and may be useful for ovarian cancer screening.

Assisting the diagnosis of Graves' hyperthyroidism with Bayesian-type and SOM-type neural networks by making use of a set of three routine tests and their correlation with free T4.

In our previous paper, we proposed a novel screening method that assists the diagnosis of Graves' hyperthyroidism via two types of neural networks by making use of routine test data. This method can be applied by non-specialists during physical check-ups at a low cost and is expected to lead to rapid referrals for examination and treatment by thyroid specialists, that is, to improve patients' QOL. In this report, the amount of female sample data was increased and routine test data (14 parameters) from 120 subjects with a known diagnosis (35 patients with Graves' hyperthyroidism and 85 healthy volunteers) were adopted as training data, before 171 individuals who had also undergone the same routine tests at the Tohoku University Hospital were screened by the network for Graves' hyperthyroidism. The present re-examination of the screening method showed its high screening ability with the set of parameters used (low serum creatinine was added to the established measures of elevated alkaline phosphatase and low total cholesterol that appear in the Graves' hyperthyroidism guidelines) and robustness due to the increase of the training sample data. It was also found that there is a strong correlation between the three parameters and serum free thyroxine (FT4) in Graves' hyperthyroidism, which supports the usefulness of our screening method.

Involvement of fibroblast growth factor 18 in dedifferentiation of cultured human chondrocytes.

OBJECTIVE: Chondrocytes inevitably decrease production of cartilaginous matrices during long-term cultures with repeated passaging; this is termed dedifferentiation. To learn more concerning prevention of dedifferentiation, we have focused here on the fibroblast growth factor (FGF) family that influences chondrocyte proliferation or differentiation. MATERIALS AND METHODS: We have compared gene expression between differentiated cells in passage 3 (P3) and dedifferentiated ones in P8 of human cultured chondrocytes. We also performed ligand administration of the responsive factor or its gene silencing, using small interfering RNA (siRNA). RESULTS: FGFs 1, 5, 10, 13 and 18 were higher at P8 compared to P3, while FGFs 9 and 14 were lower. Especially, FGF18 showed a 10-fold increase by P8. Ligand administration of FGF18 in the P3 cells, or its gene silencing using siRNA in the P8 cells, revealed dose-dependent increase and decrease respectively in type II collagen/type I collagen ratio. Exogenous FGF18 also upregulated expression of transforming growth factor beta (TGF-beta), the anabolic factor of chondrocytes, in P3 chondrocytes, but P8 cells maintained a low level of TGF-beta expression, suggesting a decrease in responsiveness of TGF-beta to FGF18 stimulation in the dedifferentiated chondrocytes. CONCLUSION: FGF18 seems to play a role in maintenance of chondrocyte properties, although its expression was rather high in dedifferentiated chondrocytes. Upregulation of FGF18 in dedifferentiated chondrocytes implied that it may be a marker of dedifferentiation.

Selection of highly osteogenic and chondrogenic cells from bone marrow stromal cells in biocompatible polymer-coated plates.

To enrich the subpopulation that preserves self-renewal and multipotentiality from conventionally prepared bone marrow stromal cells (MSCs), we attempted to use 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer-coated plates that selected the MSCs with strong adhesion ability and evaluated the proliferation ability or osteogenic/chondrogenic potential of the MPC polymer-selected MSCs. The number of MSCs that were attached to the MPC polymer-coated plates decreased with an increase in the density of MPC unit (0-10%), whereas no significant difference in the proliferation ability was seen among these cells. The surface epitopes of CD29, CD44, CD105, and CD166, and not CD34 or CD45, were detectable in the cells of all MPC polymer-coated plates, implying that they belong to the MSC category. In the osteogenic and chondrogenic induction, the MSCs selected by the 2-5% MPC unit composition showed higher expression levels of osteoblastic and chondrocytic markers (COL1A1/ALP, or COL2A1/COL10A1/Sox9) at passage 2, compared with those of 0-1% or even 10% MPC unit composition, while the enhanced effects continued by passage 5. The selection based on the adequate cell adhesiveness by the MPC polymer-coated plates could improve the osteogenic and chondrogenic potential of MSCs, which would provide cell sources that can be used to treat the more severe and various bone/cartilage diseases.

The application of atelocollagen gel in combination with porous scaffolds for cartilage tissue engineering and its suitable conditions.

For improving the quality of tissue-engineered cartilage, we examined the in vivo usefulness of porous bodies as scaffolds combined with an atelocollagen hydrogel, and investigated the suitable conditions for atelocollagen and seeding cells within the engineered tissues. We made tissue-engineered constructs using a collagen sponge (CS) or porous poly(L-lactide) (PLLA) with human chondrocytes and 1% hydrogel, the concentration of which maximized the accumulation of cartilage matrices. The CS was soft with a Young's modulus of less than 1 MPa, whereas the porous PLLA was very rigid with a Young's modulus of 10 MPa. Although the constructs with the CS shrank to 50% in size after a 2-month subcutaneous transplantation in nude mice, the PLLA constructs maintained their original sizes. Both of the porous scaffolds contained some cartilage regeneration in the presence of the chondrocytes and hydrogel, but the PLLA counterpart significantly accumulated abundant matrices in vivo. Regarding the conditions of the chondrocytes, the cartilage regeneration was improved in inverse proportion to the passage numbers among passages 3-8, and was linear with the cell densities (10(6) to 10(8) cells/mL). Thus, the rigid porous scaffold can maintain the size of the tissue-engineered cartilage and realize fair cartilage regeneration in vivo when combined with 1% atelocollagen and some conditioned chondrocytes.

Single administration of 1-benzyl-1,2,3,4-tetrahydroisoquinoline increases the extracellular concentration of dopamine in rat striatum.

We performed a combined neurochemical and behavioral study to determine the effects of 1-benzyl-1,2,3,4-tetrahydroisoquinoline (1-BnTIQ) on the extracellular dopamine concentrations in the striatum. Single dose administration of 1-BnTIQ (20, 40, and 80 mg/kg i.p.) increased striatal dopamine extracellular levels in a dose-dependent manner when an in vivo microdialysis technique was used to assess dopamine levels in the striatum of rats. Enhancement of striatal dopamine levels by systemic administration of a single dose of 1-BnTIQ was suppressed by perfusion of tetrodotoxin and a calcium ion-free solution into the striatum. This 1-BnTIQ-induced increase in extracellular dopamine concentration was also inhibited by pre-treatment with a dopamine uptake inhibitor, GBR12909 (1-(2-[bis(4-Fluorophenyl)-4-(3-phenylpropyl)piperazine dihydrochloride). Local application of 1-BnTIQ into the striatum via a dialysis probe failed to enhance the extracellular concentration of dopamine. However, microinjection of 1-BnTIQ into the substantia nigra pars compacta increased the extracellular dopamine levels in the striatum. Locomotor activity was increased by systemic administration of a single dose of 1-BnTIQ in a dose-dependent manner. This 1-BnTIQ-induced locomotor activity was attenuated by pre-treatment with SCH23390 (R(+)-7-Chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochlodride) and raclopride, D(1) and D(2) dopaminergic receptor antagonists, respectively. Moreover, 1-BnTIQ induced ipsilateral rotational behavior in 6-hydroxydopamine-lesioned rats. These results suggest that systemic administration of a single dose of 1-BnTIQ increases striatal extracellular dopamine concentration through activation of dopaminergic nigra striatal neurons via the dopamine transporter.

[Postoperative risk management of chest surgery in intensive care unit (ICU)].

The postoperative risk management of chest surgery in intensive care unit (ICU) must be considered in the measure of patient safety of the hospital organization, ICU and chest surgery itself. In reference to a patient safety, measures of a section promoting medical safety, a maintenance and check of ventilators and machines especially in the ICU, and an improvement of knowledge for treatment of critical ill patients must are warranted. In the postoperative patient undergoing chest surgery such as a lobectomy, the postoperative pain management is important and measures for early ambulation to maintenance of vital capacity must be performed.

Efficacy of open patch-grafting under cardiopulmonary bypass for pulmonic stenosis in small dogs.

OBJECTIVE: To assess the efficacy of an open patch-graft technique under cardiopulmonary bypass (CPB) in small dogs. DESIGN AND METHODS: A retrospective analysis of 10 dogs with pulmonic stenosis. Records between 1992 and 2002 were reviewed. The effect of surgical correction was evaluated and perioperative parameters were compared between survivors and non-survivors. RESULTS: The postoperative pulmonary pressure gradient was reduced in all seven surviving patients. Mean +/- SE was 21.5 +/- 7.4 mmHg (range 3.0-54.2 mmHg) and 6/7 dogs were < 40 mmHg at 3 months postoperatively. Comparing the data between those patients that survived and those that did not, the preoperative pressure gradient (P = 0.04) and volume of the Glucose-Insulin-Kalium solution used (P = 0.001) were significantly higher in those that did not survive. CONCLUSION: Open patch-grafting can be performed in small-breed dogs and decreased the pulmonary pressure gradient in survivors at 3 months postoperatively. However, this technique is more invasive than balloon valvuloplasty and should be used cautiously in severely stenosed patients.

Long-time exposure of mouse embryos to the sperm produces high levels of reactive oxygen species in culture medium and relates to poor embryo development.

Small amounts of reactive oxygen species (ROS), metabolites of oxygen, are necessary for sperm-fertilizing capability. However, in excessive levels, their role in infertility has been extensively studied. The conventional in vitro fertilization (IVF) method employs a prolonged co-incubation of gametes for 16-18 h to reach fertilization. However, it has been shown that this long period might create high levels of ROS. We aimed at finding out whether ROS increases in vitro during prolonged incubation with fertilized oocytes and whether high level of ROS relates to poor embryo development. To confirm if levels of ROS relate to length of time, we measured the ROS levels in fertilization medium (FM), which contained mouse embryos exposed to spermatozoa. To evaluate the contribution of sperm in production of ROS, we measured the ROS in the medium with only sperm. The measurements were performed by chemiluminescence assay using luminol as a probe after 4 and 18 h of incubation separately. The ROS levels were significantly increased after 18 h as compared with 4 h (p < 0.0001). Moreover, ROS in the medium with only sperm was also increased after 18 h (p < 0.0001), demonstrating that they were generated either by spermatozoa or as a result of possible reaction of sperm with medium during prolonged incubation. In addition, we compared embryo development after 2, 4, 6, 8, 10, 12 and 18 h of incubation. The number of degenerated embryos exposed to sperm for 12 and 18 h was significantly higher than those exposed for 4 or 6 h (p < 0.01). These results demonstrate that ROS concentrations appear to be related to the length of incubation time, and their excessive levels have a negative effect on embryo development. We suggest reducing incubation time to at least 4 h.

Effect of Lipo-PGE1 on health-related quality of life in patients with systemic sclerosis and systemic lupus erythematosus in Japan.

We investigated the effect of Lipo-PGE(1), a prostaglandin (PG) E(1) preparation used to treat cutaneous ulcers associated with systemic sclerosis (SS) and systemic lupus erythematosus (SLE), on health-related quality of life (HR-QOL) using the Medical Outcome Study 36-item Short-Form Health Survey (SF-36) questionnaire. A total of 192 SS and SLE patients were treated for 3 months. At baseline the scores for each of the five SF-36 subscales were significantly lower than the age- and sex-adjusted standard values for the Japanese general population. After treatment, mean (+/- SD) SF-36 scores for body pain and general health perception significantly increased from 48.6 +/- 24.1 to 55.3 +/- 26.1 and from 36.8 +/- 16.7 to 40.2 +/- 17, respectively. Emotional QOL parameters including vitality and mental health, however, showed no improvement. Physician-rated symptom scores significantly improved after administration of Lipo-PGE(1). In conclusion, Lipo-PGE(1) improved both cutaneous ulcers and HR-QOL, especially physical QOL.

Involvement of the protein kinase Cgamma isoform in development of tolerance to nitrous oxide-induced antinociception in mice.

Prolonged exposure to nitrous oxide (N2O) results in development of acute tolerance to its antinociceptive effect. Cross-tolerance to N2O-induced antinociception is also observed in morphine-tolerant animals. Despite increasing evidence of tolerance development to N2O-induced antinociception, the details of the mechanisms that underlie this tolerance remain unknown. The present study was conducted to investigate the involvement of brain protein kinase C (PKC) isoform in these two types of tolerance to N2O-induced antinociception in mice. Prolonged exposure (41 min in total, including 30 min pre-exposure and 11 min of antinociceptive testing) to 70% N2O produced a reduction in N2O-induced antinociception, indicating development of acute tolerance. The prolonged exposure to 70% N2O caused an activation of PKCgamma isoform in the brain, but not the PKCepsilon isoform. Pretreatment with a PKCgamma-antisense oligonucleotide but not the corresponding mismatch oligonucleotide (i.c.v.) prevented the development of acute tolerance to N2O-induced antinociception. Chronic morphine treatment (10 mg/kg, s.c., b.i.d. for 5 days) resulted in development of tolerance to morphine-induced antinociception and cross-tolerance to N2O-induced antinociception. The development of tolerance to morphine and cross-tolerance to N2O were both inhibited by pretreatment with PKC inhibitor, chelerythrine (1 nmol, i.c.v.). Morphine-tolerant mice showed an activation of PKC within the brain, which was suppressed by pretreatment with chelerythrine (1 nmol, i.c.v.). Thus, activation of brain PKC, in particular, the PKCgamma isoform, appears to play an important role in the development of both acute tolerance and cross-tolerance to N2O-induced antinociception in mice.

Gastric mucin is expressed in a subset of endocervical tunnel clusters: type A tunnel clusters of gastric phenotype.

AIMS: Gastric mucin expression has been demonstrated in a group of endocervical glandular lesions. The aim of this study was to gain further insight into endocervical lesions with a gastric phenotype. METHODS AND RESULTS: Various types of tunnel clusters (TC) were examined for gastric mucin by alcian blue/periodic acid-Schiff staining and immunohistochemistry for HIK1083. Five of 34 cases of TC expressed gastric mucin defined by PAS dominant neutral mucin and immunopositivity for pyloric gland mucin. Histologically, TC expressing gastric mucin showed lobular arrangements of small to medium-sized glands composed of mucin-rich columnar cells and were classified as Flumann's type A TC. Neither type B TC nor normal endocervical glands expressed PAS dominant neutral mucin and none of them was immunopositive for pyloric gland mucin. Five patients with type A TC of gastric phenotype ranged in age from 33 to 79 years (mean 58 years) and were multiparous. Type A TC of gastric phenotype, ranging from 2 to 4 mm in maximum diameter, were incidental findings in hysterectomy specimens. CONCLUSION: Type A TC of gastric phenotype could be related to lobular endocervical glandular hyperplasia of gastric phenotype. The pathogenesis of gastric metaplasia in TC remains unclear.

Hard tissue formation in subcutaneously transplanted rat dental pulp.

While dental pulp appears to be able to form mineralized matrices that do not always resemble dentin, the precise characteristics of the hard tissue and the mechanism of its induction remain unknown. Therefore, we evaluated hard tissue induced by transplantation of pulp into subcutaneous tissue. Seven days after transplantation, initial hard tissue was formed at the inner periphery of the pulp. After 14 days, this hard tissue expanded inwardly. Mineralized matrix was immunopositive for osteocalcin, osteopontin, and bone sialoprotein, but negative for dentin sialoprotein. Transplantation of GFP-labeled pulp into wild-type rats showed these formative cells to have been derived from the transplant. TEM observation revealed apatite crystals within necrotic cells and matrix vesicles at the initial stage of calcification. These results indicate that pulp cells possess the ability to form a bone- or cementum-like matrix. Calcification of the matrix may occur in necrotic cells and matrix vesicles, followed by collagenous calcification.

Ca channel currents inhibited by serum from select patients with Guillain-Barré syndrome.

We performed an electrophysiological study demonstrating inhibition of spontaneous muscle action potentials within a coculture of rat muscle and spinal cord by exposure to serum, as well as purified IgG, from patients with the acute motor axonal neuropathy (AMAN) variant of Guillain-Barré syndrome (GBS). However, exposure to serum from two patients with the acute inflammatory demyelinating polyneuropathy (AIDP) form of GBS had no effect. Using a whole-cell recording technique, we then investigated the effects of serum and purified IgG from patients with GBS on voltage-dependent calcium channel (VDCC) currents in nerve growth factor-differentiated PC12 cells. Serum from patients with GBS (AMAN) inhibited VDCC currents in PC12 cells, which was fully reversible by washing with the bath solution. Similarly, purified IgG from the serum of two patients with GBS (AMAN) also inhibited VDCC currents in PC12 cells. In contrast, sera from patients with AIDP and healthy volunteers did not affect VDCC currents in PC12 cells. These results suggest that muscle weakness in some patients with GBS might be induced by inhibition of Ca2+ channel currents within motor nerve terminals.