Phthalocyanine Tetrasulfonates Affect the Amyloid Formation and Cytotoxicity of α-Synuclein†

Alpha-synuclein is a pathological component of Parkinson's disease by constituting the filamentous component of Lewy bodies. Phthalocyanine (Pc) effects on the amyloidosis of alpha-synuclein have been examined. The copper complex of phthalocyanine tetrasulfonate (PcTS-Cu(2+)) caused the self-oligomerization of alpha-synuclein while Pc-Cu(2+) did not affect the protein, indicating that introduction of the sulfonate groups was critical for the selective protein interaction. The PcTS-Cu(2+) interaction with alpha-synuclein has occurred predominantly at the N-terminal region of the protein with a K(d) of 0.83 microM apart from the hydrophobic NAC (non-Abeta component of Alzheimer's disease amyloid) segment. Phthalocyanine tetrasulfonate (PcTS) lacking the intercalated copper ion also showed a considerable affinity toward alpha-synuclein with a K(d) of 3.12 microM, and its binding site, on the other hand, was located at the acidic C-terminus. These mutually exclusive interactions between PcTS and PcTS-Cu(2+) toward alpha-synuclein resulted in distinctive features on the kinetics of protein aggregation, morphologies of the final aggregates, and their in vitro cytotoxicities. The PcTS actually suppressed the fibrous amyloid formation of alpha-synuclein, but it produced the chopped-wood-looking protein aggregates. The aggregates showed rather low toxicity (9.5%) on human neuroblastoma cells (SH-SY5Y). In fact, the PcTS was shown to effectively rescue the cell death of alpha-synuclein overexpressing cells caused by the lactacystin treatment as a proteasome inhibitor. The anti-aggregative and anti-amyloidogenic properties of PcTS were also demonstrated with alcohol dehydrogenase, glutathione S-transferase, and amyloid beta/A4 protein under their aggregative conditions. The PcTS-Cu(2+), on the other hand, promoted the protein aggregation of alpha-synuclein, which gave rise to the fibrillar protein aggregates whose cytotoxicity became significant to 35.8%. Taken together, the data provided in this study indicate that PcTS/PcTS-Cu(2+) could be considered as possible candidates for the development of therapeutic or prophylactic strategies against the alpha-synuclein-related neurodegenerative disorders.

Bruton's tyrosine kinase phosphorylates cAMP-responsive element-binding protein at serine 133 during neuronal differentiation in immortalized hippocampal progenitor cells

Bruton's tyrosine kinase (BTK) is a member of the Tec family of kinases, which is a subgroup of the nonreceptor cytoplasmic protein tyrosine kinases. BTK has been shown to be important in the proliferation, differentiation, and signal transduction of B cells. Mutations in BTK result in B cell immune deficiency disorders, such as X-linked agammaglobulinemia in humans and X-linked immunodeficiency in mice. Although BTK plays multiple roles in the life of a B cell, its functional role in neuronal cells has not been elucidated. In the present study, we demonstrate that BTK activates transcription factor, cAMP response element (CRE)-binding protein (CREB), and subsequent CRE-mediated gene transcription during basic fibroblast growth factor (bFGF)-induced neuronal differentiation in immortalized hippocampal progenitor cells (H19-7). The kinase activity of BTK is also induced by bFGF, and BTK directly phosphorylates CREB at Ser-133 residue, indicating that BTK has a dual protein kinase activity. In addition, blockading BTK activation significantly inhibits CREB phosphorylation as well as the neurite outgrowth induced by bFGF in H19-7 cells. These results suggest that the activation of BTK and the subsequent phosphorylation of CREB at Ser-133 are important in the neuronal differentiation of hippocampal progenitor cells.

Parkin cleaves intracellular alpha-synuclein inclusions via the activation of calpain

Mutations in the alpha-synuclein and parkin genes cause heritable forms of Parkinson's disease. In the present study, we examined the possible functional relationship between the parkin and alpha-synuclein genes in a conditionally immortalized embryonic hippocampal cell (H19-7) line. Whereas transient transfection of alpha-synuclein into neuronal H19-7 cells caused the formation of its intracytoplasmic inclusions and a significant cell death, the combined overexpression of parkin restored the alpha-synuclein-induced decrease in cell viability to control levels. In addition, the overexpression of parkin was found to generate selective cleavage of alpha-synuclein. Furthermore, the cytoprotective effect of parkin on alpha-synuclein-induced cell death was not inhibited in the presence of a proteasome inhibitor. Interestingly, the overexpression of parkin induced the activation of an intracellular cysteine protease, calpain, but not caspase, and the cytoprotective effect of parkin on alpha-synuclein cytotoxicity was significantly inhibited by the presence of calpain-specific inhibitors. In conclusion, our results suggest that parkin accelerates the degradation of alpha-synuclein via the activation of the nonproteasomal protease, calpain, leading to the prevention of alpha-synuclein-induced cell death in embryonic hippocampal progenitor cells.

Induction of MUC8 gene expression by interleukin-1 beta is mediated by a sequential ERK MAPK/RSK1/CREB cascade pathway in human airway epithelial cells

Mucins are the major components of the mucus layer that covers and protects the respiratory, digestive, and reproductive tracts. Our previous studies showed that MUC8 gene expression was overexpressed in in vivo polyp epithelium in chronic sinusitis and was also increased by treatment with inflammatory mediators in an in vitro culture condition. However, the mechanisms by which the inflammatory mediators-induced MUC8 gene expression in normal nasal epithelial cells evolved remain unclear. We examined the mechanism by which the important proinflammatory mediator, interleukin (IL)-1 beta, increases MUC8 gene expression levels. We found that pharmacologic and genetic inhibition of ERK MAPK pathway abolished IL-1 beta-induced MUC8 gene expression in normal human nasal epithelial cells. Moreover, the overexpression of wide-type or of the dominant-negative mutant of p90 ribosomal S6 protein kinase 1 (RSK1) enhanced or suppressed, respectively, IL-1 beta-induced MUC8 gene expression. RSK1 was found to directly phosphorylate cAMP-response element-binding protein (CREB), and this event led to the stimulation of subsequent CRE-mediated gene transcription. In conclusion, IL-1 beta was found to induce MUC8 gene expression via a sequential ERK/RSK1/CREB pathway in human airway epithelial cells.

Regulation of Cyr61/CCN1 gene expression through RhoA GTPase and p38MAPK signaling pathways

Cysteine-rich protein 61 (Cyr61/CCN1) is an angiogenic factor and a member of a family of growth factor-inducible immediate-early genes with functions in cell adhesion, proliferation and differentiation. We investigated the regulatory mechanisms and signaling pathways involved in Cyr61/CCN1gene activation in smooth muscle cells. Treatment of these cells with sphingosine 1-phosphate (S1P), a bioactive lysolipid, increased rapidly but transiently the expression of the Cyr61/CCN1 gene at both the mRNA and protein levels. Cyr61/CCN1 mRNA stability was not altered but the transcription rate of the Cyr61/CCN1 gene was increased fivefold in isolated nuclei from S1P-stimulated cells indicating that the level of control is primarily transcriptional. Transfection experiments showed that a 936-bp promoter fragment of the human Cyr61/CCN1 gene is functional and induces a reporter gene activity in S1P-treated cells. Using a combination of cis-element mutagenesis and expression of dominant negative inhibitors of transcription factors, we showed that both a CRE and AP-1 site and their cognate transcription factors, cAMP response element binding protein (CREB) and AP-1, were responsible for the promoter activity in S1P-stimulated cells. Furthermore, by using either pharmacological inhibitors or active forms of known signaling molecules, we showed that inducible Cyr61/CCN1 gene expression occurs through RhoA GTPase and that additional signaling through the p38 pathway is required. In particular, p38 seems to regulate Cyr61/CCN1 promoter activity through modulation of phosphorylation of CREB and the CREB kinase, MSK1. These findings demonstrate the transcriptional regulation of the Cyr61/CCN1 gene and provide clues to the signaling molecules and transcription factors involved in such regulation.

Assessing outcome after hand surgery: the current state

An overview of the current state of outcome measurement after hand surgery is presented. The paper focuses on the development, application and strengths and weaknesses of it also reviews the existing questionnaires and suggests recommendations for use in research or clinical practice.

Interleukin-1 beta and tumor necrosis factor-alpha induce MUC5AC overexpression through a mechanism involving ERK/p38 mitogen-activated protein kinases-MSK1-CREB activation in human airway epithelial cells

Mucin hypersecretion is commonly observed in many inflammatory diseases of the respiratory tract. MUC5AC is generally recognized to be a major airway mucin because MUC5AC is highly expressed in the goblet cells of human airway epithelium. Moreover, it is regulated by various inflammatory cytokines. However, the mechanisms by which the interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha induce MUC5AC gene expression in normal nasal epithelial cells, and the signal molecules involved, especially in the downstream signaling of mitogen-activated protein (MAP) kinases, remain unclear. Here we show that pharmacologic or genetic inhibition of either ERK or p38 MAP kinase pathway abolished IL-1beta- and TNF-alpha-induced MUC5AC gene expression in normal human nasal epithelial cells. Our results also indicate that the activation of mitogen- and stress-activated protein kinase 1 (MSK1) and cAMP-response element-binding protein and cAMP-response element signaling cascades via ERK and p38 MAP kinases are crucial aspects of the intracellular mechanisms that mediate MUC5AC gene expression. Taken together, these studies give additional insights into the molecular mechanism of IL-1beta- and TNF-alpha-induced MUC5AC gene expression and enhance our understanding on mucin hypersecretion during inflammation.

Expression of angiogenic factor Cyr61 during neuronal cell death via the activation of c-Jun N-terminal kinase and serum response factor

The immediate early gene, cyr61, is transcriptionally activated within minutes by serum and serum growth factors. The encoded Cyr61 protein is secreted into the extracellular matrix and promotes cell adhesion and migration. In this study, we sought to examine the expression profile of cyr61 gene during neuronal cell death induced by various toxic stimuli and the mechanisms involved. Our data show that toxic stimuli, such as etoposide, significantly increased cyr61 mRNA levels in immortalized hippocampal progenitor (H19-7) cells. Cyr61 transcriptional activation was corroborated at the protein level as well. To identify the upstream signaling cascades involved in cyr61 gene induction, the blocking effect of either JNK or p38 kinase-signaling pathway on cyr61 induction in response to etoposide was tested. Transfection of the cells with a kinase-deficient mutant MEKK, an upstream activator of JNK, significantly decreased the cyr61 expression induced by etoposide. In contrast, cyr61 mRNA levels did not change after pretreatment with SB203580, the p38 kinase inhibitor. When the induction of cyr61 was tested by using several of its deleted promoters driving the expression of reporter gene, the promoter activation occurred primarily within the region containing an SRE-like CArG box. In addition, the SRF, which binds to the CArG site, was directly phosphorylated by active JNK. Furthermore, the blockade of cyr61 gene expression using an antisense encoding cyr61 sequence significantly inhibited the cell death induced by etoposide. Overall, these results suggest that the induction of the immediate early gene, cyr61, is important for neuronal cell death in the central nervous system hippocampal progenitor cells, and JNK activation, but not of p38, as well as the subsequent SRF phosphorylation are involved in cyr61 gene induction.

Pyrrolidine dithiocarbamate-induced neuronal cell death is mediated by Akt, casein kinase 2, c-Jun N-terminal kinase, and IkappaB kinase in embryonic hippocampal progenitor cells

Pyrrolidine dithiocarbamate (PDTC) is known to induce cell death by the stimulation of intracellular zinc transport and subsequent modulation of nuclear factor-kappaB (NF-kappaB) activity. Zinc is a signaling messenger that is released by neuronal activity at many central excitatory synapses. Excessive synaptic release of zinc followed by entry into vulnerable neurons contributes to severe neuronal cell death. In the present study, we explored how PDTC modulates intracellular signal transduction pathways, leading to neuronal cell death. The exposure of immortalized embryonic hippocampal cells (H19-7) to PDTC within the range of 1-100 microM caused cell death in a dose-dependent manner. During the cell death, NF-kappaB activity increased in response to PDTC, and this activity corresponded well with the increase of intracellular free zinc levels, implying that the activation of NF-kappaB transmits the cell death signals of PDTC. Furthermore, PDTC caused the activation of IkappaB kinase (IKK), casein kinase 2 (CK2), phosphatidylinositol 3-kinase (PI-3K), and Akt, as well as mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), but not p38 kinase. The blockade of PI-3K, JNK, and CK2 pathways resulted in a remarkable suppression of PDTC-induced cell death and also the activation of IKK, which subsequently led to a decrease of IkappaB phosphorylation. Although the overexpression of dominant-negative SEK in a transient manner did not inhibit the activation of Akt by PDTC, the transfection of kinase-inactive Akt mutants did cause a remarkable blockade of JNK activation, implying that Akt is present upstream of JNK in the PDTC-signaling pathways. Moreover, whereas selective CK2 inhibitors suppressed PDTC-induced JNK activation, the inhibition of JNK did not affect CK2 activity, suggesting that CK2 is directly related to the regulation of cell viability by PDTC and that the CK2-JNK pathway could be a downstream target of PDTC. Taken together, our results suggest that PDTC-mediated accumulation of intracellular zinc ions may affect cell viability by modulating several intracellular signaling pathways in neuronal hippocampal progenitor cells.

Evidence that alpha-synuclein functions as a negative regulator of Ca(++)-dependent alpha-granule release from human platelets

alpha-Synuclein has been implicated in the pathogenesis of Parkinson disease (PD) and related neurodegenerative disorders. More recently, it has been suggested to be an important regulatory component of vesicle transport in neuronal cells. alpha-Synuclein is also highly expressed in platelets and is loosely associated with the membrane of the secretory alpha-granules. However, the functional significance of these observations is unknown. In this study, the possible function of alpha-synuclein in vesicle transport, with particular regard to alpha-granule release from the platelets, was investigated. The results showed that ionomycin- or thrombin-induced alpha-granule secretion was inhibited by exogenous alpha-synuclein addition in a dose-dependent manner. However, [(3)H]5-HT release from the dense granules and hexosaminidase release from the lysosomal granules were not affected. Two point mutants (A30P and A53T) found in some familial types of PD, in addition to beta-synuclein and alpha-synuclein112, effectively inhibited PF4 release from the alpha-granules. However, the deletion mutants, which completely lacked either the N-terminal region or the C-terminal tail, did not affect alpha-granule release. Interestingly, exogenously added alpha-synuclein appeared to enter the platelets but did not change the Ca(++) level in the platelets at the resting state and the increase in the Ca(++) level on stimulation. Electron microscopy also supported that alpha-synuclein inhibits alpha-granule release. These results suggest that alpha-synuclein may function as a specific negative regulator of alpha-granule release in platelets.

alpha-Synuclein interacts with phospholipase D isozymes and inhibits pervanadate-induced phospholipase D activation in human embryonic kidney-293 cells

alpha-Synuclein has been implicated in the pathogenesis of many neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. Although the function of alpha-synuclein remains largely unknown, recent studies have demonstrated that this protein can interact with phospholipids. To address the role of alpha-synuclein in neurodegenerative disease, we have investigated whether it binds phospholipase D (PLD) and affects PLD activity in human embryonic kidney (HEK)-293 cells overexpressing wild type alpha-synuclein or the mutant forms of alpha-synuclein (A53T, A30P) associated with Parkinson's disease. Tyrosine phosphorylation of alpha-synuclein appears to play a modulatory role in the inhibition of PLD, because mutation of Tyr(125) to Phe slightly increases inhibitory effect of alpha-synuclein on PLD activity. Treatment with pervanadate or phorbol myristate acetate inhibits PLD more in HEK 293 cells overexpressing alpha-synuclein than in control cells. Binding of alpha-synuclein to PLD requires phox and pleckstrin homology domain of PLD and the amphipathic repeat region and non-Abeta component of alpha-synuclein. Although biologically important, co-transfection studies indicate that the interaction of alpha-synuclein with PLD does not influence the tendency of alpha-synuclein to form pathological inclusions. These results suggest that the association of alpha-synuclein with PLD, and modulation of PLD activity, is biologically important, but PLD does not appear to play an essential role in the pathophysiology of alpha-synuclein.

Stress-induced aggregation profiles of GST-alpha-synuclein fusion proteins: role of the C-terminal acidic tail of alpha-synuclein in protein thermosolubility and stability

Alpha-synuclein is a well-known heat-resistant protein that does not aggregate upon heat treatment, whereas glutathione S-transferase (GST) is a heat-labile protein that easily precipitates as a result of thermal stress. This paper reports the role of the C-terminal acidic tail of alpha-synuclein in protein thermosolubility and stability. The region of alpha-synuclein that is responsible for the heat resistance was initially investigated using a series of deletion mutants, and the C-terminal acidic tail (residues 96-140) was found to be crucial for the thermosolubility of alpha-synuclein. The thermal behavior of the GST-alpha-synuclein fusion protein was next investigated, and the fusion protein was seen to be extremely heat-resistant. Using a series of GST-synuclein deletion mutants, the C-terminal acidic tail of alpha-synuclein was shown to play a critical role in conferring the heat resistance of the fusion proteins. Furthermore, the acidic tail appeared to protect the fusion protein from pH- and metal-induced protein aggregation, suggesting that the acidic tail can increase the virtual stability of the protein by protecting it from the aggregation induced by environmental stresses. Interestingly, the acidic tail also appeared to protect the GST enzyme from the thermal inactivation to a considerable extent. However, CD analysis of the heat-induced secondary structural changes of the GST-alpha-synuclein fusion protein revealed that the fusion protein is irreversibly denatured by heat treatment with a slightly lowered melting temperature (Tm). Thus, the results demonstrate that introducing an acidic tail into GST promotes the thermosolubility and virtual stability of the fusion protein, although it might be unfavorable for its intrinsic stability.

Association between maternal diabetes mellitus and newborn oral cleft

Diabetes mellitus has been implicated in several studies as a possible etiological factor of various congenital anomalies. Oral clefts are common congenital malformations that may severely affect the quality of life. The authors conducted a population-based case-control study using the 1996 National Center for Health Statistics United States Natality database to investigate whether maternal diabetes mellitus is a risk factor (p < 0.05) for having a newborn with an oral cleft. The patients consisted of 2,207 live births with cleft lip/palate, and the control subjects were 4,414 randomly selected live births, excluding those with other congenital defects. After adjusting for potential confounding variables, diabetic mothers were found to be 1.352 times (95% confidence interval, 1.004-1.821; p < 0.05) more likely than nondiabetic mothers to have a newborn with cleft lip/palate. In counseling expectant mothers, early glycemic control may be an important factor in decreasing the incidence of this congenital anomaly.

Is negative ulnar variance a risk factor for Kienböck's disease? A meta-analysis

Current treatment for Kienbock's disease using joint-leveling procedures is based on the hypothesis that the disease is caused by negative ulnar variance. The authors conducted a meta-analysis to evaluate this hypothesis, and assessed the quality of available published studies. They searched MEDLINE to collect literature that evaluated this association. Only 3 of 18 collected studies had sufficient data or study design to meet their inclusion criteria. A summary odds ratio (OR) calculated using a conservative random-effect method showed that the odds of Kienböck's disease was 3.10 times more likely for those with negative ulnar variance than those with positive or neutral ulnar variance, but this was not significant (95% confidence interval, 0.95-10.05; p = 0.06). The combined OR was unstable because of marked heterogeneity across the studies. This meta-analysis reveals that there is insufficient data to support a significant (p < 0.05) association between negative ulnar variance and Kienbock's disease.

Protein kinase Dyrk1 activates cAMP response element-binding protein during neuronal differentiation in hippocampal progenitor cells

Dyrk is a dual specific protein kinase thought to be involved in normal embryo neurogenesis and brain development. Defects/imperfections in this kinase have been suggested to play an important role in the mental retardation of patients with Down's syndrome. The transcriptional factor cAMP response element-binding protein (CREB) has been implicated in the formation of many types of synaptic plasticity, such as learning and memory. In the present study we show that Dyrk1 activity is markedly induced during the differentiation of immortalized hippocampal progenitor (H19-7) cells. The addition of a neurogenic factor, basic fibroblast growth factor, to the H19-7 cells results in an increased specific binding of Dyrk1 to active CREB. In addition, Dyrk1 directly phosphorylates CREB, leading to the stimulation of subsequent CRE-mediated gene transcription during the neuronal differentiation in H19-7 cells. Blockade of Dyrk1 activation significantly inhibits the neurite outgrowth as well as CREB phosphorylation induced by basic fibroblast growth factor. These findings suggest that Dyrk1 activation and subsequent CREB phosphorylation is important in the neuronal differentiation of central nervous system hippocampal cells.

Inhibitory effect of dry needling on the spontaneous electrical activity recorded from myofascial trigger spots of rabbit skeletal muscle

OBJECTIVE

Dry needling of myofascial trigger points can relieve myofascial pain if local twitch responses are elicited during needling. Spontaneous electrical activity (SEA) recorded from an active locus in a myofascial trigger point region has been used to assess the myofascial trigger point sensitivity. This study was to investigate the effect of dry needling on SEA.

DESIGN

Nine adult New Zealand rabbits were studied. Dry needling with rapid insertion into multiple sites within the myofascial trigger spot region was performed to the biceps femoris muscle to elicit sufficient local twitch responses. Very slow needle insertion with minimal local twitch response elicitation was conducted to the other biceps femoris muscle for the control study. SEA was recorded from 15 different active loci of the myofascial trigger spot before and immediately after treatment for both sides. The raw data of 1-sec SEA were rectified and integrated to calculate the average integrated value of SEA.

RESULTS

Seven of nine rabbits demonstrated significantly lower normalized average integrated value of SEA in the treatment side compared with the control side (P < 0.05). The results of two-way analysis of variance show that the mean of the normalized average integrated value of SEA in the treatment group (0.565 +/- 0.113) is significantly (P < 0.05) lower than that of the control (0.983 +/- 0.121).

CONCLUSIONS

Dry needling of the myofascial trigger spot is effective in diminishing SEA if local twitch responses are elicited. The local twitch response elicitation, other than trauma effects of needling, seems to be the primary inhibitory factor on SEA during dry needling.

Differential activation of phospholipases by mitogenic EGF and neurogenic PDGF in immortalized hippocampal stem cell lines

In several neuronal systems, nerve growth factor (NGF) and platelet-derived growth factor (PDGF) act as neurogenic agents, whereas epidermal growth factor (EGF) acts as a mitogenic agent. Hippocampal stem cell lines (HiB5) immortalized by the expression of a temperature-sensitive SV40 large T antigen also respond differentially to EGF and PDGF. While EGF treatment at the permissive temperature induces proliferation, the addition of PDGF induces differentiation at the non-permissive temperature. However, the mechanism responsible for these different cellular fates has not been clearly elucidated. In order to clarify possible critical signaling events leading to these distinct cellular outcomes, we examined whether either EGF or PDGF differentially induces the activation of phospholipases, such as phospholipase A(2) (PLA(2)), C (PLC), or D (PLD). Although EGF stimulation did not induce phospholipases, PDGF caused a rapid and transient activation of PLC and PLD, but not PLA(2). When the activation of PLC or PLD was blocked, the neurite outgrowth induced by PDGF was significantly inhibited. Although the activation of PLD occurred faster than PLC, blocking of PLD activity by transient expression of lipase-inactive mutants did not inhibit the induction of PLC activity by PDGF. These results suggest that the differential activation of phospholipases may play an important role in signal transduction by mitogenic EGF and neurotrophic PDGF in HiB5 neuronal hippocampal stem cells. In particular, the activation of phospholipase C and D may contribute to neuronal differentiation by neurogenic PDGF in the HiB5 cells.

Use of three free flaps based on a single vascular pedicle for complex hand reconstruction in an electrical burn injury: a case report

The use of conjoint flaps based on the dorsalis pedis artery enabled a transfer of 3 free flaps-dorsalis pedis flap, fillet flap of the second toe, and trimmed large toe-to reconstruct a severely traumatized hand in a 12-year-old girl. High-voltage electrical burn injury had caused a large wound over the volar wrist and exposed the flexor tendons and median/ulnar nerves. In addition, she suffered a partial loss of the thumb and had an open wound at the base of the index finger. The application of the conjoint flaps restored hand function in a one-stage procedure.

The frequency and epidemiology of hand and forearm fractures in the United States

The purpose of this study was to estimate the frequency and describe the epidemiology of hand and forearm fractures in the United States. We extracted cases with ICD-9-CM diagnostic codes of 813.0 to 817.1 from the 1998 National Hospital Ambulatory Medical Care Survey. In 1998 there were 1,465,874 estimated cases of hand/forearm fractures, accounting for 1.5% of all emergency department cases. Radius and/or ulna fractures comprised the largest proportion of fractures (44%). The most affected age group was 5 to 14 years of age (26%). Private insurance paid for 49% of the cases. Most of the fractures occurred at home (30%); the street/highway was the second most likely fracture location (14%). Accidental falls caused the majority (47%) of fractures. Large database analysis provides important information that can be used to target interventions toward vulnerable populations and to allocate adequate resources for treating upper extremity fractures.

Zn2+-induced ERK activation mediated by reactive oxygen species causes cell death in differentiated PC12 cells

Recent studies have provided evidence that Zn2+ plays a crucial role in ischemia- and seizure-induced neuronal death. However, the intracellular signaling pathways involved in Zn2+-induced cell death are largely unknown. In the present study, we investigated the roles of mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinase (JNK), p38 MAPK and extracellular signal-regulated kinase (ERK), and of reactive oxygen species (ROS) in Zn2+-induced cell death using differentiated PC12 cells. Intracellular accumulation of Zn2+ induced by the combined application of pyrithione (5 microM), a Zn2+ ionophore, and Zn2+ (10 microM) caused cell death and activated JNK and ERK, but not p38 MAPK. Preventing JNK activation by the expression of dominant negative SEK1 (SEKAL) did not attenuate Zn2+-induced cell death, whereas the inhibition of ERK with PD98059 and the expression of dominant negative Ras mutant (RasN17) significantly prevented cell death. Inhibition of protein kinase C (PKC) and phosphatidylinositol-3 kinase had little effect on Zn2+-induced ERK activation. Intracellular Zn2+ accumulation resulted in the generation of ROS, and antioxidants prevented both the ERK activation and the cell death induced by Zn2+. Therefore, we conclude that although Zn2+ activates JNK and ERK, only ERK contributes to Zn2+-induced cell death, and that ERK activation is mediated by ROS via the Ras/Raf/MEK/ERK signaling pathway.

Multiple ligand interaction of alpha-synuclein produced various forms of protein aggregates in the presence of Abeta25-35, copper, and eosin

Various protein aggregates of alpha-synuclein developed by way of the common protein self-oligomerization in the presence of Abeta25-35, copper, and eosin were examined. All the aggregates exhibited congo red birefringence although the actual amounts of the aggregates were varied as determined by thioflavin T binding fluorescence. When their morphologies were analyzed in relation to in vitro cytotoxicity, the smallest granular aggregates obtained with copper exhibited the highest cytotoxicity, while the fibrous structures by eosin did not affect the cell.

Induction of neuronal cell death by Rab5A-dependent endocytosis of alpha-synuclein

The presynaptic alpha-synuclein is a prime suspect for contributing to Lewy pathology and clinical aspects of diseases, including Parkinson's disease, dementia with Lewy bodies, and a Lewy body variant of Alzheimer's disease. Here we examined the pathogenic mechanism of neuronal cell death induced by alpha-synuclein. The exogenous addition of alpha-synuclein caused a marked decrease of cell viability in primary and immortalized neuronal cells. The neuronal cell death appeared to be correlated with the Rab5A-specific endocytosis of alpha-synuclein that subsequently caused the formation of Lewy body-like intracytoplasmic inclusions. This was further supported by the fact that the expression of GTPase-deficient Rab5A resulted in a significant decrease of its cytotoxicity as a result of incomplete endocytosis of alpha-synuclein.

The behavior of a poly(aniline) solid contact pH selective electrode based on N,N,N',N'-tetrabenzylethanediamine ionophore

A hydrogen ion-selective solid-contact electrode based on N,N,N',N'-tetrabenzylethanediamine has shown the best Nernstian slope and selectivity and the widest response range in a Tris buffered pH sample solution. Its linear dynamic range was pH 3.50-11.94, and the Nernstian slope showed 52.1 mV/pH (at 20 +/- 0.2 degrees C). When it was directly applied to human whole blood (in pH range 6.0-8.5) we could obtain the same satisfying results. This electrode continuously contacted a Tris 7.47 buffered solution, human whole blood and a hydrofluoric acid solution for one month without any loss of performance. Also, hydrofluoric acid did not influence the surface of this electrode, and thus it was maintained without showing any changes in potentials after being used in a hydrofluoric acid solution. The standard deviation in the determined e.m.f. differences was 1.5 mV (N = 5) for Tris buffer solutions of pH 6.5 and 1.1 mV at a Tris buffer solutions of pH 8.5. The 90% response time of the electrodes obtained by injecting of hydrochloric acid into the Tris buffer sample solution was less than 10 s. Especially, in the this paper, with these potential response characteristics of hydrogen ion selective poly(aniline) solid contact electrode, we have also presented the pH response mechanism of this electrode and the role of poly(aniline) and a doped anion in a poly(aniline) layer.

Basic fibroblast growth factor-induced activation of novel CREB kinase during the differentiation of immortalized hippocampal cells

Growth factors bind to their specific receptors on the responsive cell surface and thereby initiate dramatic changes in the proliferation, differentiation, and survival of their target cells. In the present study we have examined the mechanism by which growth factor-induced signals are propagated to the nucleus, leading to the activation of transcription factor, cis-acting cAMP response element (CRE)-binding protein (CREB), in immortalized hippocampal progenitor cells (H19-7). During the differentiation of H19-7 cells by basic fibroblast growth factor (bFGF) a critical regulatory Ser(133) residue of CREB was phosphorylated followed by an increase of CRE-mediated gene transcription. Expression of S133A CREB mutants blocked the differentiation of H19-7 cells by bFGF. Although the kinetics of CREB phosphorylation by EGF was transient, bFGF induced a prolonged pattern of CREB phosphorylation. Interestingly, bFGF-induced CREB phosphorylation and subsequent CRE-mediated gene transcription is not likely to be mediated by any of previously known signaling pathways that lead to phosphorylation of CREB, such as mitogen-activated protein kinases, protein kinase A, protein kinase C, phosphatidylinositol 3-kinase-p70(S6K), calcium/calmodulin dependent protein kinase, and casein kinase 2. By using in vitro in gel kinase assay the presence of a novel 120-kDa bFGF-inducible CREB kinase was identified. These findings identify a new growth factor-activated signaling pathway that regulates gene expression at the CRE.