Expression of Vincristin-induced Peripheral Neuropathy Related to Different Administration Methods.

Vincristine (VCR) is an important drug used in R-CHOP regimens for the treatment of non-Hodgkin's lymphoma. The purpose of this study was to examine whether the administration method affects the incidence of VCR-induced peripheral neuropathy. We investigated the ratio of VCR-induced peripheral neuropathy during rapid intravenous infusion and intravenous drip infusion. A total of 71 patients who had received six or more courses of R-CHOP from January, 2015 to December, 2016 at Komaki City Hospital and Ogaki Municipal Hospital were retrospectively investigated. Peripheral neuropathy was observed in 27/39 patients (69 %) and 24/32 (75 %) in rapid intravenous infusion and intravenous drip infusion of VCR, respectively (P = 0.79). Peripheral neuropathy was observed at a high frequency in this study. Additionally, there was no difference in frequency of peripheral neuropathy due to the difference in administration method. In both groups, the degree of peripheral neuropathy was grade 1 and grade 2 in most patients. However, in rapid intravenous infusion, grade 3 peripheral neuropathy was observed. Some cases required dose reduction and discontinuation in rapid intravenous infusion. In contrast, there were no discontinuing patients in the intravenous drip infusion. Therefore, it was suggested that intravenous drip infusion of VCR reduced serious peripheral neuropathy because the ratio requiring dose reduction and discontinuation was less than that in the rapid group. In conclusion, this study is informative as there are few reports focusing on the administration method of vincristine.

Association between immune-related dermatologic adverse events and efficacy of pembrolizumab in non-small cell lung cancer patients.

We retrospectively evaluated the incidence of skin immune-related adverse effects (irAEs) in patients treated with pembrolizumab (PMB) and explored and the relationship between skin irAEs and PMB efficacy. Thirty-two patients with non-small cell lung cancer treated with PMB between April 2017 and May 2018 were enrolled. The patients were separated into two groups, namely, skin irAEs and no-skin irAEs group. We investigated the ratio and degree of express skin irAEs, period of skin irAEs and treatment, and the PFS between the two groups. Additionally, we evaluated the PFS between the irAE and no-irAEs groups. The median patient age was 76.5 (range 56-92) years. The European Cooperative Oncology Group Performance Status (ECOG PS) score of 26, 5, and 1 was 0-1, 2, and 3, respectively. The male/female ratio was 23/9. In terms of clinical stages, 6, 21, and 5 patients were in stages III and IV, and postoperative relapse, respectively. Skin irAEs were observed in 10 patients (31%). The progression-free survival of patients with skin irAEs (median, 390 days) was longer than that of patients without skin irAEs (median, 128.5 days). Overall, we suggested a significant association between skin irAEs and the efficacy of PMB in treating non-small cell lung cancer. As skin irAEs can be an indicator of treatment efficacy, it is important for medical staff, including pharmacists, to closely observe these adverse events.

Bone marrow-derived stromal cells are associated with gastric cancer progression.

BACKGROUND: The aim of this study was to clarify the role of bone marrow-derived stromal cells (BM-SCs) expressing CD271 in the development of gastric cancer. METHODS: The effect of human BM-SCs on the proliferation and motility of six gastric cancer cell lines, OCUM-2M, OCUM-2MD3, OCUM-12, KATO-III, NUGC-3, and MKN-74, was examined. CD271 expression levels in BM-SCs were analysed by flow cytometry. We also generated a gastric tumour model by orthotopic inoculation of OCUM-2MLN cells in mice that had received transplantation of bone marrow from the CAG-EGFP mice. The correlation between the clinicopathological features of 279 primary gastric carcinomas and CD271 expression in tumour stroma was examined by immunohistochemistry. RESULTS: Numerous BM-SCs infiltrated the gastric tumour microenvironment; CD271 expression was found in ∼25% of BM-SCs. Conditioned medium from BM-SCs significantly increased the proliferation of gastric cancer cell lines. Furthermore, conditioned medium from gastric cancer cells significantly increased the number of BM-SCs, whereas migration of OCUM-12 and NUGC-3 cells was significantly increased by conditioned medium from BM-SCs. CD271 expression in stromal cells was significantly associated with macroscopic type-4 cancers, diffuse-type tumours, and tumour invasion depth. The overall survival of patients (n=279) with CD271-positive stromal cells was significantly worse compared with that of patients with CD271-negative stromal cells. This is the first report of the significance of BM-SCs in gastric cancer progression. CONCLUSIONS: Bone marrow-derived stromal cells might have an important role in gastric cancer progression, and CD271-positive BM-SCs might be a useful prognostic factor for gastric cancer patients.

Features of cardioembolic stroke with persistent and paroxysmal atrial fibrillation - a study with the Japan Stroke Registry.

BACKGROUND AND PURPOSE: The stroke severity on admission and clinical outcomes were compared between ischaemic stroke patients with non-valvular atrial fibrillation (NVAF) of the persistent (PeAF) and paroxysmal (PAF) types. METHODS: The study comprised 9293 patients with cardioembolic stroke and NVAF who were registered in the Japanese stroke databank: 6522 had PeAF (70.2%) and 2771 had PAF (29.8%). Stroke severity on admission and the clinical outcomes on discharge were retrospectively compared between these patient groups. RESULTS: The National Institutes of Health Stroke Scale score on admission (median, interquartile range) was 10 (3-20) for PeAF patients and 7 (2-17) for PAF patients, indicating that stroke severity on admission was significantly worse in PeAF patients than PAF patients (P < 0.001). Good outcomes (modified Rankin scale score ≤2) were achieved by 45% PeAF patients and 53% PAF patients. Thus, PeAF patients had significantly poorer clinical outcomes than PAF patients (P < 0.001). In-hospital mortality was significantly higher amongst PeAF patients (11%) than PAF patients (8%) (P < 0.001). Multivariate analysis of factors contributing to clinical outcomes showed that PeAF was a contributing factor for in-hospital mortality (odds ratio 1.261; 95% confidence interval 1.011-1.652; P = 0.045). CONCLUSIONS: Amongst cardioembolic stroke patients with NVAF, those with PeAF have significantly higher stroke severity on admission than those with PAF, and PeAF is a factor contributing to in-hospital mortality. Thus, our study suggests that the type of atrial fibrillation affects stroke severity and clinical outcomes following cerebral infarction.

Effects of biosurfactants, mannosylerythritol lipids, on the hydrophobicity of solid surfaces and infection behaviours of plant pathogenic fungi.

AIMS: To investigate the effects of mannosylerythritol lipids (MELs) on the hydrophobicity of solid surfaces, their suppressive activity against the early infection behaviours of several phytopathogenic fungal conidia, and their suppressive activity against disease occurrences on fungal host plant leaves. METHODS AND RESULTS: The changes in the hydrophobicity of plastic film surfaces resulting from treatments with MEL solutions (MEL-A, MEL-B, MEL-C and isoMEL-B) and synthetic surfactant solutions were evaluated based on the changes in contact angles of water droplets placed on the surfaces. The droplet angles on surfaces treated with MELs were verified to decrease within 100 s after placement, with contact angles similar to those observed on Tween 20-treated surfaces, indicating decreases in surface hydrophobicity after MEL treatments. Next, conidial germination, germ tube elongation and the formation of appressorium of Blumeria graminis f. sp. tritici, Colletotrichum dematium, Glomerella cingulata and Magnaporthe grisea were evaluated on plastic surfaces that were pretreated with surfactant solutions. On the surfaces of MEL-treated plastic film, inhibition of conidial germination, germ tube elongation, and suppression of appressoria formation tended to be observed, although the level of effect was dependent on the combination of fungal species and type of MEL. Inoculation tests revealed that the powdery mildew symptom caused by B. graminis f. sp. tritici was significantly suppressed on wheat leaf segments treated with MELs. CONCLUSIONS: MELs exhibited superior abilities in reducing the hydrophobicity of solid surfaces, and have the potential to suppress powdery mildew in wheat plants, presumably due to the inhibition of conidial germination. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides significant evidence of the potential for MELs to be used as novel agricultural chemical pesticides.

A c-Met inhibitor increases the chemosensitivity of cancer stem cells to the irinotecan in gastric carcinoma.

BACKGROUND: Cancer stem cells (CSCs) may be postulated mediators of the chemoresistance. This study aimed to determine an effective signal inhibitor with effects on the proliferation of CSCs in combination with anticancer drugs. METHODS: We used three gastric cancer cell lines and three side population (SP)-enriched CSC cell lines. We examined the combined effects of inhibitors against stemness signals, including c-Met inhibitor SU11274, and five anticancer drugs on the CSC proliferation and mRNA expression of chemoresistance-associated genes. RESULTS: The IC50 of irinotecan in SP-enriched CSC was 10.5 times higher than parent OCUM-2M cells, whereas that of oxaliplatin, taxol, gemcitabine, and 5-fluorouracil was 2.0, 2.8, 2.0, and 1.2, respectively. The SP cell lines had higher expression levels of UGT1A1, ABCG2, and ABCB1 than their parent cell lines. There was a synergistic antiproliferative effect with a combination of SU11274 and SN38 in SP cells, but not other inhibitors. The SU11274 significantly decreased the expression of UGT1A1, but not ABCG2 and ABCB1. The SN38 plus SU11274 group more effectively suppressed in vivo tumour growth by OCUM-2M/SP cells than either group alone. CONCLUSION: Cancer stem cells have chemoresistance to irinotecan. The c-Met inhibitor may be a promising target molecule for irinotecan-based chemotherapy of gastric cancer.

Usefulness of MRA-DWI mismatch in neuroendovascular therapy for acute cerebral infarction.

BACKGROUND: This study evaluated the usefulness of MR angiography (MRA)-diffusion-weighted imaging (DWI) mismatch in neuroendovascular therapy over 3 h after onset of acute cerebral infarction. METHODS: The subjects were 14 cases (age, 73 ± 8.4 years) who had an anterior circulation deficit on DWI/MRA on arrival and underwent neuroendovascular therapy over 3 h after onset. MRA-DWI mismatch (MDM) (+) was defined as 'major artery lesion (+) and diffusion-weighted image-Alberta Stroke Program Early CT Score (DWI-ASPECTS) ≥6'; MDM (-) was defined as 'major artery lesion (+) and DWI-ASPECTS <6'. RESULTS: Reperfusion was achieved in nine of 14 patients (64%) undergoing neuroendovascular therapy. Within the reperfusion group, in the five MDM (+) patients and the four MDM (-) patients, the outcome was a favorable clinical response in the MDM (+) group. The modified Rankin Scale (mRS) scores after 90 days were 0-2 in 3 (60%) and 3-6 in 2 (40%) of the MDM (+) group patients and 0-2 in 0 (0%) and 3-6 in 4 (100%) of the MDM (-) group patients. In the MDM (+) group, a good outcome was achieved. However, the number of cases was small, so this was not a significant difference. Within the non-reperfusion group, in the three MDM (+) patients and the two MDM (-) patients, the mRS scores after 90 days were 0-2 in 1 (33%) and 3-6 in 2 (67%) of the MDM (+) group patients and 0-2 in 0 (0%) and 3-6 in 2 (100%) of the MDM (-) group patients. In both groups, the outcome was poor. CONCLUSIONS: With neuroendovascular therapy, a good outcome with reperfusion was achieved in the MDM (+) group compared to the MDM (-) group. This suggests that the presence or absence of MDM may be useful in determining prognosis after reperfusion.

Systemic lupus erythematosus presenting with Kikuchi-Fujimoto's disease as a long-term sequela of drug-induced hypersensitivity syndrome. A possible role of Epstein-Barr virus reactivation.

Drug-induced hypersensitivity syndrome (DIHS) is a severe form of drug eruptions associated with viral reactivations. Autoimmune diseases have been reported to develop several months or years after the resolution of DIHS. We describe a 36-year-old man with cervical lymphadenopathy and an erythematous eruption affecting the face and neck, which evolved into clinically evident systemic lupus erythematosus. He had had an episode of DIHS 4 years previously, in which human herpesvirus-6 and Epstein-Barr virus (EBV) were reactivated. Expression of EBV-encoded RNA was detected in the lymph node. On the basis of findings in this patient, we suggest that EBV is pathogenically important in the sequence of events leading to the onset of systemic lupus erythematosus and that patients with a history of DIHS may be at a risk of eventually developing autoimmune diseases.

Activation of fibroblast growth factor receptor by axotomy, through downstream p38 in dorsal root ganglion, contributes to neuropathic pain.

The possible involvement of fibroblast growth factor receptor (FGFR) activation in the dorsal root ganglion (DRG) was examined following peripheral nerve injury in the rat. Ligation of the sciatic nerve down-regulated FGFR2, -3 and -4 mRNA; however, the expression of FGFR1 mRNA showed no change. Activation of FGFR was examined by immunohistochemistry using an antibody of the phosphorylated form of FGFR1-4. Ligation of the sciatic nerve produced phosphorylation of FGFR in the L4 and 5 DRG ipsilateral to the injury, starting at 3 days after the lesion and persisting for more than 30 days. Substantial activation of FGFR was observed, mainly in unmyelinated small DRG neurons that co-expressed phosphorylated p38 mitogen-activated protein kinase (MAPK). Continuous intrathecal infusion of the FGFR1 inhibitor, 3-[3-(2-carboxyethyl)-4-methylpyrrol-2-methylidenyl]-2-indolinone, reduced p38 MAPK phosphorylation in the DRG and pain-related behaviors in the partial sciatic nerve model rat without affecting on the activation of spinal glia cells (microglia and astrocyte). In the injured small DRG neurons, activation of FGFR1 may contribute to the generation of neuropathic pain by activating p38 MAPK.

Hyperkalemia in both surgically and medically treated patients with primary aldosteronism.

Hyperkalemia is an important complication of adrenalectomy for patients with primary aldosteronism (PA). The frequency of hyperkalemia after medication using mineralocorticoid receptor antagonists (MRAs) for PA is unclear. The aim of this study is to investigate the frequency and the risk factors of hyperkalemia after surgery and medication for PA. The data of 376 patients with PA registered in a multicentre-collaborative study in Japan, including surgically treated patients (group A; n=142) and medically treated patients with MRAs (group B; n=234) were studied. The prevalence of hyperkalemic patients (serum potassium >5.0 mEq l-1) after treatment was higher in group A than group B (9.9 vs 3.8%, P<0.01). At diagnosis, the hyperkalemic patients were older and had a poorer renal function than the non-hyperkalemic patients in both groups (P<0.05). The hyperkalemic patients had severer PA in group A and milder PA in group B. The independent risk factor by a logistic regression analysis was only age in both groups. After treatment, the percentages of patients withdrawing antihypertensive drugs and the normalization of aldosterone renin ratio were not different between hyperkalemic and non-hyperkalemic patients in group A. The type and dose of MRAs and the combination of other antihypertensive drugs were not different between hyperkalemic and non-hyperkalemic patients in group B. In conclusion, the potential occurrence of hyperkalemia should be considered after medical as well as surgical treatment for PA, especially in patients with older age (>60 years) and impaired renal function (estimated glomerular filtration rate <70 ml min-1 per 1.73 m2) at diagnosis.

Significance of adrenal computed tomography in predicting laterality and indicating adrenal vein sampling in primary aldosteronism.

Although laterality assessed by computed tomography (CT) in primary aldosteronism (PA) is not always concordant with that assessed by adrenal vein sampling (AVS), it is unclear whether all patients diagnosed with PA should undergo AVS for subtype classification. The aim of the current study was to investigate the accuracy of CT in subtype classification and to develop a prediction score for bilateral subtype in patients without adrenal tumour. As part of the WAVES-J study, 393 patients with PA were analysed. Subtyping using CT was concordant with that using AVS in 68% (269/393) of patients in the total sample, and in 38% (68/156) of patients with unilateral tumours, 56% (5/9) of patients with bilateral tumours and 89% (204/228) of patients without tumour. In patients without tumour, female gender, plasma aldosterone concentration (pg ml-1) to plasma renin activity ratio ⩽550 and serum potassium ⩾3.8 mEq l-1 were shown to be independent predictors for bilateral subtype. A prediction score based on these three variables was constructed with one point attributed to each variable. A score of three points had 29% sensitivity and 96% specificity in a receiver operating characteristic curve analysis. The results suggest that although CT is not sufficiently accurate for subtype classification in patients with adrenal tumours, it is sufficient to determine bilateral subtype in patients without tumour. Moreover, using our clinical prediction score in patients without tumour could be useful in determining the necessity of AVS for subtype classification.

The effect of site and type of nerve injury on the expression of brain-derived neurotrophic factor in the dorsal root ganglion and on neuropathic pain behavior.

A number of rat neuropathy models have been developed to simulate human neuropathic pain conditions, such as spontaneous pain, hyperalgesia, and allodynia. In the present study, to determine the relative importance of injury site (proximal or distal to the primary afferent neurons) and injury type (motor or sensory), we examined pain-related behaviors and changes of brain-derived neurotrophic factor expression in the dorsal root ganglion in sham-operated rats, and in the L5 dorsal rhizotomy, L5 ventral rhizotomy, L5 dorsal rhizotomy+ventral rhizotomy, and L5 spinal nerve transection models. L5 ventral rhizotomy and spinal nerve transection produced not only mechanical and heat hypersensitivity, but also an increase in brain-derived neurotrophic factor mRNA/protein in the L5 dorsal root ganglion at 7 days after surgery. In contrast, rats in the L5 dorsal rhizotomy and dorsal rhizotomy+ventral rhizotomy groups did not show both pain behaviors at 7 days after surgery, despite brain-derived neurotrophic factor upregulation in medium- and large-size neurons in the L5 dorsal root ganglion. On the other hand, L5 spinal nerve transection, but not dorsal rhizotomy, dorsal rhizotomy+ventral rhizotomy or ventral rhizotomy, increased the expression of brain-derived neurotrophic factor in the L4 dorsal root ganglion at 7 days after surgery. Taken together, these findings suggest that the upregulation of brain-derived neurotrophic factor expression in the L4 and L5 dorsal root ganglion neurons may be, at least in part, involved in the pathophysiological mechanisms of neuropathic pain and that the selective nerve root injury models may be useful for studying the underlying mechanisms of chronic pain after nerve injury.

Noxious cold stimulation induces mitogen-activated protein kinase activation in transient receptor potential (TRP) channels TRPA1- and TRPM8-containing small sensory neurons.

Two cold-sensitive transient receptor potential (TRP) channels, TRPA1 and TRPM8, have been identified and considered interesting because of their possible roles in thermosensation, nociception and other functions. Recently, we have reported that the phosphorylation of extracellular signal-regulated protein kinase and p38 mitogen-activated protein kinase occurred in primary afferent neurons in response to noxious heat stimulation of the peripheral tissue, i.e. activity-dependent activation of extracellular signal-regulated protein kinase and p38 in dorsal root ganglion neurons. In the present study, we investigated the phosphorylation of extracellular signal-regulated protein kinase, p38, and c-Jun N-terminal kinase in the rat dorsal root ganglion by cold stimulation using immunohistochemistry. Cold stimuli (28-4 degrees C) were applied by immersion of the hind paw into a water bath (six times of 10 s stimulation and 10 s interval, total 2 min). Noxious cold stimulation induced phosphorylated-extracellular signal-regulated protein kinase and phosphorylated-p38, but not phosphorylated-c-Jun N-terminal kinase, in small to medium diameter sensory neurons with a peak at 2 min after stimulation. We found that a cold stimulation at 4 degrees C showed a marked increase in the number of activated neurons. Furthermore, double staining for phosphorylated-extracellular signal-regulated protein kinase and phosphorylated-p38 showed no colocalization in the dorsal root ganglion neurons. We then performed double-labeling experiments for TRPA1 and TRPM8 mRNA and phosphorylation of mitogen-activated protein kinase. The majority of phosphorylated-extracellular signal-regulated protein kinase-positive neurons also expressed TRPM8 mRNA, whereas phosphorylated-p38 heavily colocalized with TRPA1 mRNA after noxious cold stimulation. Our data suggest that the noxious, but not innocuous, cold stimulation in vivo induced differential activation of extracellular signal-regulated protein kinase and p38 pathways in each subpopulation containing TRPA1 or TRPM8 in dorsal root ganglion.

Brain-derived neurotrophic factor increases in the uninjured dorsal root ganglion neurons in selective spinal nerve ligation model.

Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are two major members of the neurotrophin family. Using immunohistochemistry and in situ hybridization histochemistry, we examined the effect of L5 spinal nerve ligation (SPNL), a neuropathic pain model, on the expression of BDNF in the uninjured L4 dorsal root ganglion (DRG). After L5 SPNL, both immunoreactivity for BDNF and the hybridization intensity for BDNF mRNA increased mainly in the small- and medium-sized neurons. The percentage of BDNF mRNA-expressing neurons increased in the ipsilateral L4 DRG compared with the contralateral DRG from the third to 28th day after ligation. A significantly greater number of BDNF-immunoreactive neurons were observed in the ipsilateral L4 DRG than contralateral side 14 d after ligation. To test the contribution of BDNF to the thermal hyperalgesia produced in this model, we intrathecally injected anti-BDNF antibody at third day after ligation. This treatment clearly attenuated thermal hyperalgesia for a few hours. Almost all BDNF mRNA-expressing neurons coexpressed trkA, a high-affinity NGF receptor, mRNA. The percentage of BDNF mRNA-expressing cells of trkA cells significantly increased in the ipsilateral L4 DRG 14 d after ligation. Furthermore, we examined the contribution of NGF on this phenotypic change using ELISA, Northern blot analysis, and anti-NGF antibody. NGF content in the ipsilateral L4 DRG linearly increased and reached a statistical significant level 14 d after L5 SPNL. Moreover, at this time point, the increase in NGF mRNA was observed in the ipsilateral L5 DRG and sciatic nerve, but not in the ipsilateral L4 DRG or L4 spinal nerve. Local application of anti-NGF antibody to the L4 spinal nerve beside the L5 spinal nerve-ligation site prevented the development of thermal hyperalgesia for 5 d after ligation. Our data suggest that BDNF, which increased in the uninjured L4 DRG neurons, acts as a sensory neuromodulator in the dorsal horn and contributes to thermal hyperalgesia in this neuropathic pain model. The contribution of locally synthesized NGF to thermal hyperalgesia was also demonstrated. These dynamic alterations in the expression and content of BDNF and NGF in the uninjured DRG neurons might be involved in the pathomechanisms of neuropathic pain.

Platelet-derived growth factor induces apoptosis in vascular smooth muscle cells: roles of the Bcl-2 family.

Apoptosis (programmed cell death) is observed in vascular smooth muscle cells (VSMC) in atherosclerotic lesions and stenotic lesions after injury, and modulates the cellularity of these lesions. It is recognized that cell growth and apoptosis are two linked processes. Platelet-derived growth factor (PDGF) induces VSMC proliferation and migration in vitro. We studied the effect of PDGF on apoptosis in VSMC. Cultured rat VSMC were treated with PDGF-AA or PDGF-BB. PDGF-BB induced cell death in cultured VSMC in a time- and dose-dependent manner, but PDGF-AA did not. Gel electrophoresis of genomic DNA and in situ DNA labeling confirmed that the cell death induced by PDGF-BB is apoptosis. PDGF-BB treatment reduced bcl-2 mRNA and bcl-xl mRNA expression, in contrast, induced bcl-xs mRNA expression, linked with the induction of apoptosis in cultured VSMC.

Induction of plasminogen activator inhibitor-1 and -2 in dorsal root ganglion neurons after peripheral nerve injury.

We have previously found that tissue type and urokinase type plasminogen activators (tPA and uPA) are induced in dorsal root ganglia (DRG) neurons after peripheral axotomy and that tPA plays crucial roles in generating neuropathic pain. Here we examined whether the plasminogen activator inhibitor-1 and -2 (PAI-1 and PAI-2) mRNA, endogenous inhibitors of tPA and uPA, are induced in the DRG following sciatic nerve transection. L4 and L5 DRG sections were examined using in situ hybridization histochemistry. The results showed that both PAI-1 and PAI-2 mRNA were up-regulated in DRG neurons within 1 day, and peaked at 1-3 days, after injury. Reduction of these mRNA was observed from 7 days after injury. The precise expression patterns of PAI-1 and PAI-2 mRNA at 3 days after axotomy revealed that PAI-1 mRNA was observed in predominantly small neurons, while much of the PAI-2 mRNA was expressed in large neurons. Double-labeling analysis of these mRNAs with activated transcription factor 3, known as an injury marker, revealed that most PAI-1 and PAI-2 mRNAs was induced in injured neurons. Co-expression of PAI-1, 2 with tPA and uPA in DRG neurons suggests that these inhibitors may act in an autocrine manner to modulate extracellular proteolytic activity after nerve injury.

A potential anti-allodynic mechanism of GDNF following L5 spinal nerve ligation; Mitigation of NPY up-regulation in the touch sense pathway.

Intrathecal delivery of glial cell line-derived neurotrophic factor (GDNF) reverses mechanical allodynia after 5th lumbar (L5) spinal nerve ligation (SNL). However, the molecular mechanism behind this process is not fully understood. Following sciatic nerve injury, primary afferent neurons in the injured dorsal root ganglion (DRG) begin to express neuropeptide Y (NPY) that is absent in normal DRG. The aim of the current study was to determine the relationship of this de novo expression of NPY and the anti-allodynic effect of GDNF. Following L5 SNL, 73% of neurons began to express NPY mRNA in the ipsilateral L5 DRG and robust NPY-immunoreactive fibers appeared in the ipsilateral GN where the touch-sense mediating A-fiber primary afferents from the hindpaw terminate. Seven-daylong intrathecal infusion of GDNF at the L5 DRG level, starting on day three when mechanical allodynia had fully developed, reversed once-established these changes. The GN neurons normally expressed NPY Y1 receptor, but not Y2, Y4, or Y5 receptors, and L5 SNL did not change the expression pattern. Bolus intracisternal injection of BIBP3226, a Y1 receptor antagonist, dose-dependently reversed mechanical allodynia. We demonstrated that GDNF reversed once-established mechanical allodynia as well as NPY induction in the touch-sense processing pathway. NPY could facilitate touch-sense processing by Y1 receptor in the gracile nucleus after peripheral nerve injury. GDNF may exert anti-allodynic effects through mitigation of this NPY up-regulation. The effectiveness of delayed treatment further indicates the therapeutic potential of GDNF on neuropathic pain.

De novo expression of Nav1.7 in injured putative proprioceptive afferents: Multiple tetrodotoxin-sensitive sodium channels are retained in the rat dorsal root after spinal nerve ligation.

Tetrodotoxin-sensitive (TTX-s) spontaneous activity is recorded from the dorsal roots after peripheral nerve injury. Primary sensory neurons in the dorsal root ganglion (DRG) express multiple TTX-s voltage-gated sodium channel α-subunits (Navs). Since Nav1.3 increases, whereas all other Navs decrease, in the DRG neurons after peripheral nerve lesion, Nav1.3 is proposed to be critical for the generation of these spontaneous discharges and the contributions of other Navs have been ignored. Here, we re-evaluate the changes in expression of three other TTX-s Navs, Nav1.1, Nav1.6 and Nav1.7, in the injured 5th lumbar (L5) primary afferent components following L5 spinal nerve ligation (SNL) using in situ hybridization histochemistry and immunohistochemistry. While the overall signal intensities for these Nav mRNAs decreased, many injured DRG neurons still expressed these transcripts at clearly detectable levels. All these Nav proteins accumulated at the proximal stump of the ligated L5 spinal nerve. The immunostaining patterns of Nav1.6 and Nav1.7 associated with the nodes of Ranvier were maintained in the ipsilateral L5 dorsal root. Interestingly, putative proprioceptive neurons characterized by α3 Na+/K+ ATPase-immunostaining specifically lacked Nav1.7 mRNA in naïve DRG but displayed de novo expression of this transcript following SNL. Nav1.7-immunoreactive fibers were significantly increased in the ipsilateral gracile nucleus where central axonal branches of the injured A-fiber afferents terminated. These data indicate that multiple TTX-s channel subunits could contribute to the generation and propagation of the spontaneous discharges in the injured primary afferents. Specifically, Nav1.7 may cause some functional changes in sensory processing in the gracile nucleus after peripheral nerve injury.

Novel cis element for tissue-specific transcription of rat platelet-derived growth factor beta-receptor gene.

Platelet-derived growth factor (PDGF) and its receptors are widely expressed in several tissues in the stage of cellular growth and development. In adulthood, PDGF beta-receptor (PDGFbetaR) is mainly detected in pathological conditions such as atherosclerotic lesions and injured vascular wall. The purpose of the present study was to elucidate the underlying mechanism of PDGFbetaR gene expression under pathological conditions in vascular smooth muscle cells (VSMC) and to identify the important cis elements responsible for tissue-specific gene transcription. Gel mobility shift assay and supershift assay indicated that the CCAAT motif located at -67 (C67) was mainly interacted with NF-YC, and this element drove the basal promoter activity of the gene as a putative promoter. On the other hand, another important sequence essential for the basal transcription was found at a 30-bp region (R30) spanning -150 to -121. To test whether R30 actually regulates the tissue-specific transcription of PDGFbetaR gene, electromobility shift pattern was compared between VSMC and hepatoma cell line (HTC). We obtained the result that DNA-protein complex seen only in nuclear extracts from HTC suppressed the promoter activity in HTC in a tissue-specific manner. Furthermore, cis element decoy transfection experiments for C67 and R30 also revealed that both elements were functionally important in mRNA expression of PDGFbetaR in VSMC. From these results, we concluded that the basal activity of PDGFbetaR gene expression was transactivated by the interaction or coordination of both C67 and R30, and the latter one mainly controlled the tissue-specific gene expression in VSMC.

Postprandial hypotension is associated with asymptomatic cerebrovascular damage in essential hypertensive patients.

offelucidate the relationship between postprandial hypotension (PPH) and asymptomatic cerebrovascular damage, we evaluated changes in blood pressure after a meal by 24-hour blood pressure monitoring in 70 hospitalized essential hypertensive patients aged >/=50 years. They received a diet containing standard nutritional ingredients with 120 mmol (7 g) NaCl and were free from medication for at least 1 week. PPH was defined as the mean reduction of systolic blood pressure during 2 hours after a meal. Patients were divided into three groups according to mean values of PPH after 3 meals: PPH-1 (n=16, 5 mm Hg/=10 mm Hg), and normal (n=36, PPH<5 mm Hg). As asymptomatic cerebrovascular damage, lacunae and leukoaraiosis were evaluated by magnetic resonance imaging. PPH did not correlate with daytime or nighttime blood pressure or the nondipper phenomenon; however, PPH was significantly related to asymptomatic cerebrovascular damage. The prevalence of lacunae in the normal, PPH-1, and PPH-2 groups was 44%, 69%, and 83%, respectively (chi2=8.22, P<0.05). The number of lacunae in the normal, PPH-1, and PPH-2 groups was 1.0+/-1.3, 1.3+/-1.2, and 1. 9+/-1.4, respectively (F[2,67]=3.2, P<0.05). The prevalence of advanced leukoaraiosis in the normal, PPH-1, and PPH-2 groups was 44%, 50%, and 83%, respectively (chi2=7.63, P<0.05). Severity score of leukoaraiosis in the normal, PPH-1, and PPH-2 groups was 1.5+/-0. 7, 1.7+/-0.8, and 2.1+/-0.7, respectively (F[2,67]=4.3, P<0.05). These findings indicate that elderly hypertensive patients with marked PPH should be considered to have advanced cerebrovascular damage even in the absence of abnormal neurological findings.