Enhanced expression of activity-regulated cytoskeleton-associated protein in the medial prefrontal cortex is involved in working memory performance

Working memory (WM) is a cognitive function important for guiding the on-going or upcoming behavior. A memory-related protein Arc (activity-regulated cytoskeleton-associated protein) is implicated in long-term memory consolidation. Recent evidence further suggests the involvement of hippocampal Arc in spatial WM. The medial prefrontal cortex (mPFC) is a key brain region mediating WM. However, the role of mPFC Arc in WM is still uncertain. To investigate whether mPFC Arc protein is involved in WM performance, delayed non-match to sample (DNMS) T-maze task was performed in rats with or without blocking new synthesis of mPFC Arc. In DNMS task, a 10-s or 30-s delay between the sample run and the choice run was given to evaluate WM performance. To block new Arc protein synthesis during the DNMS task, Arc antisense oligodeoxynucleotides (ODNs) were injected to the bilateral mPFC. The results show that, in rats without surgery for cannula implantation and subsequent intracerebral injection of ODNs, WM was functioning well during the DNMS task with a delay of 10 s but not 30 s, which was accompanied with a significantly increased level of mPFC Arc protein, indicating a possible link between enhanced Arc protein expression and the performance of WM. After preventing the enhancement of mPFC Arc protein expression with Arc antisense ODNs, rat's WM performance was impaired. These findings support enhanced mPFC Arc protein expression playing a role during WM performance.

Histone deacetylase inhibitor attenuates the effects of 27-hydroxycholesterol on the rat brain

Hypercholesterolemia is a risk factor for Alzheimer's disease (AD). Plasma cholesterol does not pass the blood-brain barrier whereas its metabolite 27-hydroxycholesterol (27-OHC) can enter the brain. High 27-OHC in the brain has been suggested to mediate hypercholesterolemia-induced impairments of learning and memory through promoting amyloid-β accumulation and facilitating synaptic disruption. In AD brains, the activity of histone deacetylase (HDAC) is elevated. Treating AD animals with HDAC inhibitors decreases amyloid-β levels and synaptic damages, which leads to memory improvement. Whether HDAC activity is involved in the actions of 27-OHC is still uncertain. In this study, 4 weekly injections of 27-OHC/vehicle were given to rats followed by 3 daily injections of HDAC inhibitor trichostatin (TSA)/vehicle. The results of Morris water maze test reveal that all rats have intact spatial learning ability during the 5-d training phase. However, the behavioral performance during the probe trial was impaired by 27-OHC treatment, which was improved by adding TSA treatments. Furthermore, 27-OHC treatments reduced the hippocampal levels of acetylated histone H3, acetylated α tubulin, insulin-degrading enzyme and postsynaptic protein PSD-95, indicating that 27-OHC treatments may induce enhanced HDAC activity, decreased amyloid-β clearance and synaptic disruption. All reduced levels returned to the basal levels by adding TSA treatments. These findings support our hypothesis that HDAC activity is enhanced following long-term exposure to excess 27-OHC.

[Application of microfluidic assays for cardiovascular disease markers in early warning and rapid diagnosis]

Cardiovascular disease is a major threat to human health and has become the leading cause of death worldwide; therefore, early diagnosis and treatment are of great value. Due to its miniaturization, integration, and ease of operation, microfluidic technology enables the rapid, multi-target detection of cardiovascular disease markers and significantly facilitates the early and rapid diagnosis of cardiovascular disease. This article reviews the research progress of microfluidics in cardiovascular disease detection, analyzes its advantages and weaknesses in the rapid detection of protein, lipid, and nucleic acid biomarkers, hopes to provide a reference to promote the quick detection technology of cardiovascular disease, and thus proposes new considerations for the early management of cardiovascular disease.

Chondrocyte Thrombomodulin Protects against Osteoarthritis

Osteoarthritis (OA) is a prevalent form of arthritis that affects over 32.5 million adults worldwide, causing significant cartilage damage and disability. Unfortunately, there are currently no effective treatments for OA, highlighting the need for novel therapeutic approaches. Thrombomodulin (TM), a glycoprotein expressed by chondrocytes and other cell types, has an unknown role in OA. Here, we investigated the function of TM in chondrocytes and OA using various methods, including recombinant TM (rTM), transgenic mice lacking the TM lectin-like domain (TM^LeD/LeD), and a microRNA (miRNA) antagomir that increased TM expression. Results showed that chondrocyte-expressed TM and soluble TM [sTM, like recombinant TM domain 1 to 3 (rTMD123)] enhanced cell growth and migration, blocked interleukin-1β (IL-1β)-mediated signaling and protected against knee function and bone integrity loss in an anterior cruciate ligament transection (ACLT)-induced mouse model of OA. Conversely, TM^LeD/LeD mice exhibited accelerated knee function loss, while treatment with rTMD123 protected against cartilage loss even one-week post-surgery. The administration of an miRNA antagomir (miR-up-TM) also increased TM expression and protected against cartilage damage in the OA model. These findings suggested that chondrocyte TM plays a crucial role in counteracting OA, and miR-up-TM may represent a promising therapeutic approach to protect against cartilage-related disorders.

[Trend of age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019]

Objective: To analyze the trends of the age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019. Methods: Data were extracted from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019. A total of 253 037 Han girls aged 9 to 18 years with complete data on menarche were selected in this study. They were asked one-on-one about their menstrual status, age and residence information. The median age of menarche was estimated by probability regression. U tests were used to compare the difference in median age at menarche in different years. Results: The median age at menarche (95%CI) among Chinese Han girls was 12.47 (12.09-12.83) years in 2010, 12.17 (11.95-12.38) years in 2014 and 12.05 (10.82-13.08) years in 2019, respectively. Compared with that in 2010, the median age at menarche in 2019 decreased by 0.42 years (U=-77.27, P<0.001). The annual average changes were -0.076 years from 2010 to 2014 (U=-57.19, P<0.001) and -0.023 years from 2014 to 2019 (U=-21.41, P<0.001), respectively. The average annual changes in urban areas in the periods of 2010 to 2014 and 2014 to 2019 were -0.071 years and 0.006 years, respectively, while those in rural areas were -0.082 years and -0.053 years, respectively. The average annual changes in the regions of north, northeast, east, south central, southwest and northwest were -0.064, -0.099, -0.091, -0.080, -0.096 and -0.041 years in the period of 2010 to 2014 and 0.001, -0.040, -0.002, -0.005, -0.043 and -0.081 years in the period of 2014 to 2019. Conclusion: The age of menarche among Chinese Han girls aged 9 to 18 years shows an advanced trend from 2010 to 2019, and the trends in urban and rural areas and different regions have different characteristics.

[Prevalence trend of malnutrition among Chinese Han children and adolescents aged 7-18 years from 2010 to 2019]

Objective: To analyze the prevalence trend of malnutrition among Chinese Han children and adolescents aged 7-18 years from 2010 to 2019. Methods: Based on the data from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019, about 215 102, 214 268 and 212 713 Han students aged 7-18 years were included in this study. According to the National Screening Standard for Malnutrition of School-age Children and Adolescents, the detection rate of malnutrition among Chinese Han children and adolescents aged 7-18 was calculated, and the prevalence trend of malnutrition from 2010 to 2019 was analyzed. Results: In 2019, the detection rate of malnutrition among Chinese Han students aged 7-18 years was 8.64% (18 381/212 713), of which the rate of growth retardation, moderate-to-severe wasting and mild wasting was 0.50% (1 062/212 713), 3.25% (6 914/212 713) and 4.89% (10 405/212 713), respectively. In 2019, the detection rate of malnutrition in these boys was higher than that of girls (9.97% vs. 7.31%), and the detection rate in rural areas was higher than that in cities (9.30% vs. 7.98%). The detection rates were 9.74% (5 252/53 916), 8.17% (4 408/53 937), 7.29% (3 885/53 310), and 9.38% (4 836/51 550) in 7-9, 10-12, 13-15, and 16-18 years groups, and 8.14% (6 563/80 618), 7.61% (4 237/55 694) and 9.92% (7 581/76 401) in the eastern, central, and western regions. Malnutrition among students in China was mainly caused by mild wasting, and the detection rate of growth retardation accounted for only 5.78% (1 062/18 381). Malnutrition was mostly concentrated in the southwest region, and the rate was relatively low in eastern provinces. In three surveys from 2010 to 2019, the detection rate of malnutrition among Han students aged 7-18 in China decreased gradually, and the differences were statistically significant (P<0.05). Among them, the detection rates in western rural areas decreased significantly, as well as the gap between urban and rural areas. Compared with that in 2014, the detection rate of malnutrition in Shandong, Hunan, Qinghai and Hainan provinces in 2019 decreased significantly (P<0.05). Conclusion: In 2019, the malnutrition of Chinese children and adolescents aged 7-18 years is dominated by wasting malnutrition. The detection rate shows a downward trend from 2010 to 2019, with regional differences.

[Trends of age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019]

Objective: To analyze the trends of the age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019. Methods: Data were extracted from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019. A total of 253 037 Han girls aged 9 to 18 years with complete data on menarche were selected in this study. They were asked one-on-one about their menstrual status, age and residence information. The median age of menarche was estimated by probability regression. U tests were used to compare the difference in median age at menarche in different years. Results: The median age at menarche (95%CI) among Chinese Han girls was 12.47 (12.09-12.83) years in 2010, 12.17 (11.95-12.38) years in 2014 and 12.05 (10.82-13.08) years in 2019, respectively. Compared with that in 2010, the median age at menarche in 2019 decreased by 0.42 years (U=-77.27, P<0.001). The annual average changes were-0.076 years from 2010 to 2014 (U=-57.19, P<0.001) and-0.023 years from 2014 to 2019 (U=-21.41, P<0.001), respectively. The average annual changes in urban areas in the periods of 2010 to 2014 and 2014 to 2019 were-0.071 years and 0.006 years, respectively, while those in rural areas were-0.082 years and-0.053 years, respectively. The average annual changes in the regions of north, northeast, east, south central, southwest and northwest were-0.064, -0.099, -0.091, -0.080, -0.096 and-0.041 years in the period of 2010 to 2014 and 0.001, -0.040, -0.002, -0.005, -0.043 and-0.081 years in the period of 2014 to 2019. Conclusion: The age of menarche among Chinese Han girls aged 9 to 18 years shows an advanced trend from 2010 to 2019, and the trends in urban and rural areas and different regions have different characteristics.

The D2 Dopamine Receptor Gene as a Determinant of Reward Deficiency Syndrome

The dopaminergic system, and in particular the dopamine D2 receptor, has been profoundly implicated in reward mechanisms in the brain. Dysfunction of the D2 dopamine receptors leads to aberrant substance seeking behaviour (alcohol, drug, tobacco, and food) and other related behaviours (pathological gambling, Tourette's syndrome, and attention deficit hyperactivity disorder). We propose that variants of the D2 dopamine receptor gene are important common genetic determinants of the ‘reward deficiency syndrome’.

Severe Hyperemesis Gravidarum Masking the Presentations of Hyperthyroidism

Hyperemesis gravidarum may present with weight loss and tachycardia secondary to dehydration. Its severity correlates with the level of the serum chorionic gonadotropin which can interfere with the assay of the thyroid stimulating hormone. Therefore, hyperemesis gravidarum are at times difficult to be distinguished from hyperthyroidism. Missing hyperthyroidism during pregnancy results not only in inappropriate maternal care, but adverse neonatal outcomes including low birth weight. The authors report a case of hyperemesis gravidarum complicated by the concurrence of hyperthyroidism. Goiter and refractory tachycardia are the useful clues to detect occult hyperthyroidism in patients with hyperemesis gravidarum.

[A twin study of genetic and environmental influences on relationship between attention deficit and anxiety/depression in children and adolescents]

Objective: To understand the genetic and environmental influences on the relationship between attention deficit and anxiety/depression in children and adolescents. Methods: A total of 1 062 same-sex twins aged 6-18 years were included in this study. A parent-rated child behavior checklist (CBCL) was used in the assessment. Software Mx was used to fit the univariate model of structural equation. The relationship between attention deficit and anxiety/depression was analyzed through bivariate genetic modeling. Results: The genetic factor had influence on the relationship between attention deficit and anxiety/depression (r(g)=0.48). Shared and non-shared environmental correlation scores of attention deficit and anxiety/depression were 0.86 and 0.14 respectively. Conclusion: Common genetic and shared environmental influences can explain the relationship between attention deficit and anxiety/depression in children and adolescents.

The Cholinergic Signaling Responsible for the Expression of a Memory-Related Protein in Primary Rat Cortical Neurons

Cholinergic dysfunction in the brain is closely related to cognitive impairment including memory loss. In addition to the degeneration of basal forebrain cholinergic neurons, deficits in the cholinergic receptor signaling may also play an important role. In the present study, to examine the cholinergic signaling pathways responsible for the induction of a memory-related postsynaptic protein, a cholinergic agonist carbachol was used to induce the expression of activity-regulated cytoskeleton associated protein (Arc) in primary rat cortical neurons. After pretreating neurons with various antagonists or inhibitors, the levels of carbachol-induced Arc protein expression were detected by Western blot analysis. The results show that carbachol induces Arc protein expression mainly through activating M1 acetylcholine receptors and the downstream phospholipase C pathway, which may lead to the activation of the MAPK/ERK signaling pathway. Importantly, carbachol-mediated M2 receptor activation exerts negative effects on Arc protein expression and thus counteracts the enhanced effects of M1 activation. Furthermore, it is suggested for the first time that M1-mediated enhancement of N-methyl-D-aspartate receptor (NMDAR) responses, leading to Ca(2+) entry through NMDARs, contributes to carbachol-induced Arc protein expression. These findings reveal a more complete cholinergic signaling that is responsible for carbachol-induced Arc protein expression, and thus provide more information for developing treatments that can modulate cholinergic signaling and consequently alleviate cognitive impairment. J. Cell. Physiol. 231: 2428-2438, 2016. © 2016 Wiley Periodicals, Inc.

Nonlethal dose of silver nanoparticles attenuates TNF-α-induced hepatic epithelial cell death through HSP70 overexpression

Silver nanoparticles (Ag-nps) have been widely used in various biomedical products. Compared with its hazardous effects extensively being studied, rare attention has been paid to the potential protective effect of Ag-nps to human health. The present study was designed to evaluate the protective effects of Ag-nps and heat shock treatment on tumor necrosis factor-α (TNF-α)-induced cell damage in Clone 9 cells. Clone 9 cells were pretreated with nonlethal concentration of Ag-nps (1 μg/ml) or heat shock, and then cell damages were induced by TNF-α (1 ng/ml). Protective effects of Ag-nps administration or heat shock treatment were determined by examining the TNF-α-induced changes in cell viabilities. The results showed that the intensity of cytotoxicity produced by TNF-α was alleviated upon treatment with nonlethal concentration of Ag-nps (1 μg/ml). Similar protective effects were also found upon heat shock treatment. These data demonstrate that Ag-nps and heat shock treatment were equally capable of inducing heat shock protein 70 (HSP70) protein expression in Clone 9 cells. The results suggest that clinically Ag-nps administration is a viable strategy to induce endogenous HSP70 expression instead of applying heat shock. In conclusion, our study for the first time provides evidence that Ag-nps may act as a viable alternative for HSP70 induction clinically.

Performance enhancement using a non-uniform vertical electric field and polymer networks for in-plane switching of multi-pretilt, vertically aligned liquid crystal devices

A simple and reproducible alignment method for fabricating vertically aligned (VA) liquid crystal (LC) cells with a multi-pretilt structure is developed. A non-uniform vertical electric field is employed in the LC/monomer mixed cells during the photocuring process, and two pretilt domains with a functional small pretilt angle (∼1.6°) in the stabilized VA LC/polymer cells are achieved. The enhanced electro-optical performance of the cell driven by an in-plane switching field is demonstrated. Compared to the pure cell, the 2 wt.% pretilt angle cell shows 36%, 64%, and 76% improvement in the optical switch, the gray-level rise time, and the gray-level fall time responses, respectively, which are obtained at a low driving voltage (≤12  V). When applied to LC devices, the proposed method not only effectively benefits the LC molecular alignment, but it also significantly boosts the electro-optical performance.

Insulin can induce the expression of a memory-related synaptic protein through facilitating AMPA receptor endocytosis in rat cortical neurons

Learning and memory depend on long-term synaptic plasticity including long-term potentiation (LTP) and depression (LTD). Activity-regulated cytoskeleton-associated protein (Arc) plays versatile roles in synaptic plasticity mainly through inducing F-actin formation, underlying consolidation of LTP, and promoting AMPA receptor (AMPAR) endocytosis, underlying LTD. Insulin can also induce LTD by facilitating the internalization of AMPARs. In neuroblastoma cells, insulin induced a dramatic increase in Arc mRNA and Arc protein levels, which may underlie the memory-enhancing action of insulin. Thus, a hypothesis was made that, in response to insulin, increased AMPAR endocytosis leads to enhanced Arc expression, and vice versa. Primary cultures of neonatal Sprague-Dawley rat cortical neurons were used. Using Western-blot analysis and immunofluorescent staining, our results reveal that inhibiting AMPAR-mediated responses with AMPAR antagonists significantly enhanced whereas blocking AMPAR endocytosis with various reagents significantly prevented insulin (200 nM, 2 h)-induced Arc expression. Furthermore, via surface biotinylation assay, we demonstrate that acute blockade of new Arc synthesis after insulin stimulation using Arc antisense oligodeoxynucleotide prevented insulin-stimulated AMPAR endocytosis. These findings suggest for the first time that an interaction exists between insulin-stimulated AMPAR endocytosis and insulin-induced Arc expression.

Exercise prevents the increased anxiety-like behavior in lactational di-(2-ethylhexyl) phthalate-exposed female rats in late adolescence by improving the regulation of hypothalamus-pituitary-adrenal axis

Both the detrimental effects of early life adversity and the beneficial effects of exercise on the hypothalamic-pituitary-adrenal (HPA) axis have been reported. Early life exposure to di-(2-ethylhexyl)-phthalate (DEHP) may impair the development of endocrine system. In this study, we investigated the effects of lactational DEHP exposure on stress responses in late adolescent female rats and examined the protective role of treadmill running. Sprague-Dawley dams were fed with DEHP (10mg/kg per day) or vehicle during lactation. After weaning, the female offspring rats were trained to exercise on a treadmill for 5 weeks and then stressed by exploring on an elevated plus maze. The activities of HPA axis were evaluated by measuring the plasma levels of ACTH and corticosterone, the expressions of adrenal enzymes cholesterol side-chain cleavage enzyme (CYP11A1) and cytochrome P-450 11β-hydroxylase (CYP11B1), and the expression of hypothalamic glucocorticoid receptors (GR). The results demonstrate that DEHP-exposed rats exhibited enhanced anxiety-like behaviors. Increased hypothalamic GR and plasma ACTH levels, but decreased adrenal CYP11A1 and corticosterone levels, were observed in DEHP-exposed animals under stressed condition. Importantly, in DEHP-exposed animals, exercise during childhood-adolescence reduced anxiety-like behaviors by normalizing stress-induced alterations in ACTH level and adrenal CYP11A1 expression. The findings of this study suggest that treadmill running may provide beneficial effects on ameliorating the dysregulation of HPA axis in lactational DEHP-exposed adolescent female rats.

Baicalein Inhibits HMGB1 Release and MMP-2/-9 Expression in Lipopolysaccharide-Induced Cardiac Hypertrophy

Myocardial dysfunction, a common complication after sepsis, significantly contributes to the death of patients with septic shock. In the search for potentially effective drugs to decrease mortality from sepsis, we investigated the cardioprotective effects of baicalein, a flavonoid present in the root of Scutellaria baicalensis, on lipopolysaccharide (LPS)-induced pro-inflammatory cytokine production and matrix metalloproteinase-2 and -9 (MMP-2/-9) expression. We found that baicalein significantly attenuated LPS-induced cardiac hypertrophy and counteracted reactive oxygen species (ROS) generation in neonatal rat cardiomyocytes. In addition, pretreatment with baicalein inhibited LPS-induced early (e.g., tumor necrosis factor-α (TNF-α) and interleukin-6) and late (e.g., high mobility group box 1 (HMGB1) pro-inflammatory cytokine release, inducible nitric oxide synthase (iNOS) expression and NO production. Finally, baicalein also significantly down-regulated the expression of MMP-2/-9 and attenuated HMGB1 translocation from the nucleus to the cytoplasm. These results suggest that baicalein can protect cardiomyocytes from LPS-induced cardiac injury via the inhibition of ROS and inflammatory cytokine production. These cardioprotective effects are possibly mediated through the inhibition of the HMGB1 and MMP-2/-9 signaling pathways.

Baicalein, an active component of Scutellaria baicalensis Georgi, prevents lysophosphatidylcholine-induced cardiac injury by reducing reactive oxygen species production, calcium overload and apoptosis via MAPK pathways

Background

Lysophosphatidylcholine (lysoPC), a metabolite from membrane phospholipids, accumulates in the ischemic myocardium and plays an important role in the development of myocardial dysfunction ventricular arrhythmia. In this study, we investigated if baicalein, a major component of Huang Qui, can protect against lysoPC-induced cytotoxicity in rat H9c2 embryonic cardiomyocytes.

Methods

Cell viability was detected by the MTT assay; ROS levels were assessed using DCFH-DA; and intracellular free calcium concentrations were assayed by spectrofluorophotometer. Cell apoptosis and necrosis were evaluated by the flow cytometry assay and Hoechst staining. Mitogen-Activated Protein Kinases (MAPKs), which included the ERK, JNK, and p38, and the apoptotic mechanisms including Bcl-2/Bax, caspase-3, caspase-9 and cytochrome c pathways were examined by Western blot analysis. The activation of MAPKs was examined by enzyme-linked immunosorbent assay.

Results

We found that lysoPC induced death and apoptosis of H9c2 cells in a dose-dependent manner. Baicalein could prevent lysoPC-induced cell death, production of reactive oxygen species (ROS), and increase of intracellular calcium concentration in H9c2 cardiomyoctes. In addition, baicalein also inhibited lysoPC-induced apoptosis, with associated decreased pro-apoptotic Bax protein, increased anti-apoptotic Bcl-2 protein, resulting in an increase in the Bcl-2/Bax ratio. Finally, baicalein attenuated lysoPC-induced the expression of cytochrome c, casapase-3, casapase-9, and the phosphorylations of ERK1/2, JNK, and p38. LysoPC-induced ERK1/2, JNK, and p38 activations were inhibited by baicalein.

Conclusions

Baicalein protects cardiomyocytes from lysoPC-induced apoptosis by reducing ROS production, inhibition of calcium overload, and deactivations of MAPK signaling pathways.

Di-(2-ethylhexyl)-phthalate reduces MyoD and myogenin expression and inhibits myogenic differentiation in C2C12 cells

The purpose of this study was to investigate the effects of di-(2-ethylhexyl) phthalate (DEHP) treatment on MyoD and myogenin expression and myotube formation in the murine C2C12 cells. Myogenic differentiation is principally regulated by activities of myogenic regulatory factors, such as MyoD and myogenin, leading the elongation and fusion of mononucleated myoblasts into multinucleated myotubes. In the present study, myogenic differentiation of C2C12 cells was induced by serum deprivation with medium containing vehicle or DEHP (10, 100, 1,000 μg/ml) for 5 days. Using 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay clearly demonstrated cell viability was not affected by DEHP at any given dose. At the dose of 1,000 μg/ml DEHP, the elongation of multinucleated myotubes, and the percent of nuclei incorporated into myosin heavy chain (MyHC)-stained myotubes were markedly reduced. In addition, immunoblotting revealed expression of muscle specific marker MyHC, as well as myogenic regulatory factors MyoD and myogenin, were reduced in DEHP-treated myotubes during myogenic differentiation. Taken together, the results showed that DEHP may impair myogenic differentiation through repression of myogenic regulatory factors, such as MyoD and myogenin, resulting in a reduction of MyHC expression. This in vitro study suggests that DEHP may be an environmental risk factor for myogenesis.

Both PKMζ and KIBRA are closely related to reference memory but not working memory in a T-maze task in rats

Protein kinase M zeta (PKMζ) and the kidney and brain protein (KIBRA) play important roles in various forms of memories. However, whether they are involved in performing the T-maze task is still unknown. In this study, the delayed nonmatch-to-sample (DNMS) task in a T-maze was given to rats. The percentage of correct choices denoting the performance accuracy was calculated and the protein levels of PKMζ and KIBRA in rat's prefrontal cortex were measured. The results showed significantly increased performance accuracy after the training phase, which was maintained on the next day in groups with a delay of 10 s but not 30 s, indicating that 30 s is too long for rats to maintain working memory. As for the expressions of PKMζ and KIBRA, significant increases were observed 1 day after the training phase, indicating that the formation of reference memory accompanies an increase in PKMζ and KIBRA. No significant difference was found among groups with various delay intervals, indicating that the expressions of PKMζ and KIBRA exert no effects on the performance of working memory. These results provide the first evidence that KIBRA as well as PKMζ is closely related to reference memory but not working memory in rats.

Severe Hyperemesis Gravidarum Masking the Presentations of Hyperthyroidism

Hyperemesis gravidarum may present with weight loss and tachycardia secondary to dehydration. Its severity correlates with the level of the serum chorionic gonadotropin which can interfere with the assay of the thyroid stimulating hormone. Therefore, hyperemesis gravidarum are at times difficult to be distinguished from hyperthyroidism. Missing hyperthyroidism during pregnancy results not only in inappropriate maternal care, but adverse neonatal outcomes including low birth weight. The authors report a case of hyperemesis gravidarum complicated by the concurrence of hyperthyroidism. Goiter and refractory tachycardia are the useful clues to detect occult hyperthyroidism in patients with hyperemesis gravidarum.

Amyloid-beta interrupts the PI3K-Akt-mTOR signaling pathway that could be involved in brain-derived neurotrophic factor-induced Arc expression in rat cortical neurons

The deposition of amyloid-beta (Abeta) contributes to the pathogenesis of Alzheimer's disease. Even at low levels, Abeta may interfere with various signaling cascades critical for the synaptic plasticity that underlies learning and memory. Brain-derived neurotrophic factor (BDNF) is well known to be capable of inducing the synthesis of activity-regulated cytoskeleton-associated protein (Arc), which plays a fundamental role in modulating synaptic plasticity. Our recent study has demonstrated that treatment of fibrillar Abeta at a nonlethal level was sufficient to impair BDNF-induced Arc expression in cultured rat cortical neurons. In this study, BDNF treatment alone induced the activation of the phosphatidylinositol 3-kinase-Akt-mammlian target of rapamycin (PI3K-Akt-mTOR) signaling pathway, the phosphorylation of eukaryotic initiation factor 4E binding protein (4EBP1) and p70 ribosomal S6 kinase (p70S6K), the dephosphorylation of eukaryotic elongation factor 2 (eEF2), and the expression of Arc. Interrupting the PI3K-Akt-mTOR signaling pathway by inhibitors prevented the effects of BDNF, indicating the involvement of this pathway in BDNF-induced 4EBP1 phosphorylation, p70S6K phosphorylation, eEF2 dephosphorylation, and Arc expression. Nonlethal Abeta pretreatment partially blocked these effects of BDNF. Double- immunofluorescent staining in rat cortical neurons further confirmed the coexistence of eEF2 dephosphorylation and Arc expression following BDNF treatment regardless of the presence of Abeta. These results reveal that, in cultured rat cortical neurons, Abeta interrupts the PI3K-Akt-mTOR signaling pathway that could be involved in BDNF-induced Arc expression. Moreover, this study also provides the first evidence that there is a close correlation between BDNF-induced eEF2 dephosphorylation and BDNF-induced Arc expression. (c) 2009 Wiley-Liss, Inc.

Malignancies associated with dermatomyositis and polymyositis in Taiwan: a nationwide population-based study

BACKGROUND

Previous studies showed that idiopathic inflammatory myopathies (IIM) carried an increased risk of cancers. However, no large-scale study of IIM has been conducted in the Chinese population.

OBJECTIVES

We sought to delineate the association of IIM and various cancer types from a nationwide database in Taiwan.

METHODS

We analysed the published national data from records of National Health Insurance claims. Cases of dermatomyositis (DM) and polymyositis (PM) from 2000 to 2005 and cancers registered in the catastrophic illness profile from 1997 to 2006 were collected. A nationally representative cohort of 1,000,000 enrollees was included for comparison.

RESULTS

In total, 136 patients (12.8%) among 1059 cases of DM and 46 persons (7.0%) among 661 cases of PM carried internal malignancies. Patients with DM tended to have cancers of nasopharynx, lung and breast. On the other hand, patients with PM tended to have breast, uterine cervix and lung cancers. Compared with the general population, DM gave a 10-fold increased risk for cancers, in which a 66-fold increased risk for nasopharyngeal carcinoma and a 31-fold increased risk for lung cancer were the two most significant. For patients with PM, a 6-fold increased risk for cancer was observed. Juvenile DM had a 16-fold increased risk for haematopoietic or lymphoid malignancy. Two thirds of comorbid malignancies were detected shortly after the diagnoses of IIM, within a mean of 1-2 years. Overall, younger patients with IIM carried the highest risk for malignancies, especially those in their twenties and thirties.

CONCLUSIONS

This is the first large-scale study to report the associated malignancies and the cancer risk of IIM in Taiwan.

Functional changes on ascending auditory pathway in rats caused by germanium dioxide exposure: an electrophysiological study

The semiconductor element, germanium (Ge), is essential for the manufacture of modern integrated circuits. Because of its anti-tumor and immunomodulative effects, Ge-containing compounds are also used as health-promoting ingredients in food. However, some histological studies have shown the toxic effects of Ge-containing compounds on various organs, including the central nervous system. Even now, the effect of germanium on auditory system function is not completely clear. To clarify this question, brainstem auditory evoked potentials (BAEPs) were applied to examine the effect of germanium dioxide (GeO(2)) on the ascending auditory pathway. Since the voltage-gated sodium channel is important to neuron activation and nerve conduction, the effect of GeO(2) on voltage-gated sodium channels was also examined. The result revealed GeO(2) elevated the BAEPs threshold dose-dependently. GeO(2) also prolonged latencies and interpeak latencies (IPLs) of BAEPs, but the amplitudes of suprathreshold intensities (90dB) did not show any obvious change. In addition, the results of whole cell patch clamp studies indicated GeO(2) reduced inward sodium current. These results suggest the toxic effect of GeO(2) on the conduction of the auditory system, and that inhibitory effect of GeO(2) on the voltage-gated sodium channels might play a role in GeO(2)-induced abnormal hearing loss.

Germanium dioxide induces mitochondria-mediated apoptosis in Neuro-2A cells

Germanium (Ge) is commonly used in the semiconductor industry as well as health-promoting and medical field. Biologically, germanium possesses erythropoietic, anti-microbial, anti-tumor, anti-amyloidosis, and immunomodulative effects. However, toxic effects of Ge-containing compounds on kidney, muscle, neuronal cells, and nerves have been reported. Mitochondrial dysfunction was found to be involved in the pathogenesis of GeO(2)-induced nephropathy and myopathy. Since it is well known that mitochondria play a major role in apoptosis triggered by many stimuli, an effort was made to examine whether the Ge-induced neurotoxicity occurs through mitochondria-mediated apoptosis. A mouse neuroblastoma cell line, Neuro-2A, was used in the present study. After incubating with 0.1-800microM of GeO(2) for 0-72h, the cell viability of Neuro-2A cells was inhibited in a dose- and time-dependent manner. Further analysis showed that aside from the changes in the nuclear morphology responsible for apoptosis, the release of cytochrome c, the loss of mitochondrial membrane potential, the translocation of Bax, and the reduction of Bcl-2 expression were also observed in Neuro-2A cells after GeO(2) treatment. These results indicate that the mitochondria-mediated apoptosis is involved in this in vitro model of GeO(2)-induced neurotoxicity.

The prescriptions frequencies and patterns of Chinese herbal medicine for allergic rhinitis in Taiwan

BACKGROUND

The evaluation of Chinese herbal medicines (CHM) to allergic rhinitis (AR) by large-scale pharmaco-epidemiological study is not ease found, although CHM had been reported to have potential effect for AR in some clinical trials.

AIMS OF THE STUDY

To explore the frequency and pattern of CHM prescriptions on AR, we have the study by analysing the population-based CHM database in Taiwan.

METHODS

The way for this study was linked and processed the complete traditional Chinese medicine database for Taiwanese recorded in the year 2002. The diagnosis of AR was extracted with the only single ICD-9 Code of 477 to calculate the frequency and pattern of prescriptions. Association rule was applied to analyse co-prescription of CHM for patients with AR.

RESULTS

In the year 2002, among the 22 520 776 valid beneficiaries of the National Health Insurance, Taiwan, 914 612 subjects (3.8% of the total valid beneficiaries) have diagnosed AR. There were 35.6% of AR patients been treated by CHM. The peak age of AR patients treated by CHM was at the first decade (0-10). For the AR patients, the most common Chinese herbal formula prescription was Shin-yi-qing-fei-tang, or Angelica dahurica (Bai-zhi) for the single Chinese herb. While for the combination treatments the most common prescription was the two formulae, Xiao-qing-long-tang and Shin-yi-san.

CONCLUSIONS

Because of the high utilization rate of the CHM treatment for AR, a large-scale randomized trial warrants further research for its efficacy and safety.

Amyloid-β at sublethal level impairs BDNF-induced arc expression in cortical neurons

Alzheimer's disease (AD) is characterized by progressive memory loss and cognitive dysfunction that probably due to a deficit in synaptic plasticity. One member of neurotrophins, brain-derived neurotrophic factor (BDNF), is known to be involved in the hippocampal long-term potentiation (LTP), a cellular model for learning and memory. Moreover, activity-regulated cytoskeleton-associated gene (Arc), an immediate early gene, is found to be a downstream effector of the BDNF signaling cascade. Inhibition of Arc protein synthesis impairs both the maintenance of LTP and the consolidation of long-term memory. In addition, the formation of senile plaques is a pathological feature in AD and mainly consists of the deposition of amyloid-beta (Abeta), a proteolytic product of amyloid precursor protein. Several studies concerning neurobehavioral performance have suggested that Abeta at sublethal levels interfere with the signaling cascades critical for synaptic plasticity and thus lead to the cognitive impairment in early stage of AD. Whether the BDNF-mediated Arc synthesis is impaired by sublethal Abeta in early AD is still unclear. Therefore, in the present study, primary cultures of neonatal rat cortical neurons were used to evaluate the effect of sublethal Abeta on the BDNF-induced Arc protein expression. Consistent with the literature, Arc, an indicator of synaptic plasticity, was induced by BDNF (25 ng/ml) in both dose- and time-dependent manners. After treating cultures with sublethal Abeta (5 microM), a significant suppression was observed on the level of BDNF-induced Arc protein expression. This result indicates that Abeta at sublethal level impairs the BDNF-mediated signaling in cortical neurons and thus underlies the deficits of synaptic plasticity occurred at the early stage of AD before significant neuronal loss.

Cdc42 participates in the regulation of ADF/cofilin and retinal growth cone filopodia by brain derived neurotrophic factor

Rho family GTPases have important roles in mediating the effects of guidance cues and growth factors on the motility of neuronal growth cones. We previously showed that the neurotrophin BDNF regulates filopodial dynamics on growth cones of retinal ganglion cell axons through activation of the actin regulatory proteins ADF and cofilin by inhibiting a RhoA-dependent pathway that phosphorylates (inactivates) ADF/cofilin. The GTPase Cdc42 has also been implicated in mediating the effects of positive guidance cues. In this article we investigated whether Cdc42 is involved in the effects of BDNF on filopodial dynamics. BDNF treatment increases Cdc42 activity in retinal neurons, and neuronal incorporation of constitutively active Cdc42 mimics the increases in filopodial number and length. Furthermore, constitutively active and dominant negative Cdc42 decreased and increased, respectively, the activity of RhoA in retinal growth cones, indicating crosstalk between these GTPases in retinal growth cones. Constitutively active Cdc42 mimicked the activation of ADF/cofilin that resulted from BDNF treatment, while dominant negative Cdc42 blocked the effects of BDNF on filopodia and ADF/cofilin. The inability of dominant negative Cdc42 to block ADF/cofilin activation and stimulation of filopodial dynamics by the ROCK inhibitor Y-27632 indicate interaction between Cdc42 and RhoA occurs upstream of ROCK. Our results demonstrate crosstalk occurs between GTPases in mediating the effects of BDNF on growth cone motility, and Cdc42 activity can promote actin dynamics via activation of ADF/cofilin.

Neurobehavioral changes in Taiwanese lead-exposed workers

OBJECTIVE

The dysfunction of the central nervous system (CNS) caused by lead exposure was evaluated.

METHODS

Workers who have been exposed to lead for at least 3 years and have been informed of having elevated blood lead levels (BLLs) were recruited. According to their current BLLs, 33 and 28 males were assigned to the medium (40-80 microg/dL) and low (<40 microg/dL) BLLs groups, respectively. Sixty-two nonexposed healthy men served as the control group. Their neurobehaviors were examined by a computerized evaluation system.

RESULTS

Significantly impaired neurobehavioral functions were shown in the medium BLLs group, which included slow performance of psychomotor tasks, impaired processing of visual-spatial information, reduced memory and learning functions, low performance accuracy, slow execution of responses, and poor attentional control.

CONCLUSIONS

Subtle CNS dysfunction could be detected from lead-exposed workers who have no obvious neurologic and cognitive deficits.

Lead-induced attenuation in the aggregation of acetylcholine receptors during the neuromuscular junction formation

Lead (Pb2+) toxicity is more common in children and is associated with cognitive deficits, which may reflect lead-induced changes in central synaptic development and function. Aside from neurotoxicity, lead exposure may also impact mature neuromuscular junction (NMJ) and cause muscle weakness. NMJ is known as a peripheral cholinergic synapse and its signaling cascades responsible for development are similar to those for the central synapses. However, the effect of lead exposure on the formation of NMJ in mammals is unclear. In the present study, a NG108-15/C2C12 coculture model was used to measure the acetylcholine receptor (AChR) aggregates formed on the myotubes which was an early hallmark for the NMJ formation. AChR aggregates were identified by alpha-bungarotoxin under fluorescent microscope. Single dose of lead acetate with final concentrations at 10(-3), 10(-1), or 10 microM was applied to dishes at the beginning of coculturing. Following 3-day exposure, although NG108-15 cells could extend long neurites to nearby myotubes, obvious dose-dependent attenuation in AChR aggregation was shown. The averaged area of an AChR aggregate, the averaged number of AChR aggregates per myotube, and the total area of AChR aggregates per myotube were all significantly decreased. In addition, the distribution percentages of various sizes of AChR aggregates showed that almost half of the AChR aggregates were formed with a size of 2-5 microm2 regardless of lead exposure. After treating 10 microM of lead acetate, significantly more AChR aggregates ranged from 2 to 20 microm2 were formed and significantly less AChR aggregates larger than 20 microm2 were formed. These results indicated that lead exposure reduced the extent of AChR aggregation concerning both the size and number of AChR aggregates and large AChR aggregates could hardly be formed after acute high-level lead exposure. No significant change was found in the total amount of AChRs on the myotubes after lead exposure, which indicated that the attenuation of AChR aggregation was not caused by reducing the synthesis of AChRs but by remaining dispersed pattern of AChRs on the myotubes. These data suggest that lead exposure exerts detrimental effects on the formation of NMJ.

Implication of nNOS in the enlargement of AChR aggregates but not the initial aggregate formation in a novel coculture model

The aggregation of nicotinic acetylcholine receptors (AChRs) is an early hallmark of the formation of neuromuscular junction (NMJ), and nitric oxide is recently known to play an important role. In many NMJ studies, nerve-muscle coculture model was used, and NG108-15 cells, a neuroblastoma x glioma hybrid cell line, were the most frequently used nerve cells. However, possible contributions from glial cells could not be excluded. In this study, Neuro-2a neuroblastoma cells were used instead of [corrected] coculture with myotubes, and the relationship between AChR aggregation and spatiotemporal expression and activation of nNOS (neuronal nitric oxide synthase) was examined. Upon coculture, AChR aggregates were observed by FITC-conjugated alpha-bungarotoxin, and double labeling of AChRs and neurofilament showed that the neurites of a Neuro-2a cell innervated several myotubes. After treating the cocultures with single dose of L-NAME at the end of 1-day [corrected] coculturing, only slight effect on AChR aggregation could be found indicating that nNOS is not related to the initial formation of AChR aggregates. In contrast, when L-NAME treatment was given at the end of a 3-day coculturing, the day just before reaching the maximum extent of AChR aggregation, new AChR aggregates were hardly formed and the preformed AChR aggregates were even dispersed indicating that the enlargement of AChR aggregates is highly dependent on the nNOS activity. Double-labeling study of nNOS and AChR further showed that the coupling of membranous nNOS to regions nearby the AChR aggregates was essential for the enlargement of AChR aggregates. These results not only revealed the spatiotemporal relationship between AChR aggregation and nNOS activity but also verified the feasibility and usefulness of using Neuro-2a cells in a coculture model.

Modifier of cell adhesion regulates N-cadherin-mediated cell-cell adhesion and neurite outgrowth

Modifier of cell adhesion (MOCA) is a member of the dedicator of cytokinesis 180 family of proteins and is highly expressed in CNS neurons. MOCA is associated with Alzheimer's disease tangles and regulates the accumulation of amyloid precursor protein and beta-amyloid. Here, we report that MOCA modulates cell-cell adhesion and morphology. MOCA increases the accumulation of adherens junction proteins, including N-cadherin and beta-catenin, whereas reducing endogenous MOCA expression lowers cell-cell aggregation and N-cadherin expression. MOCA colocalizes with N-cadherin and actin in areas of cell-cell and cell substratum contact and is expressed in neuronal processes. MOCA accumulates during neuronal differentiation, and its expression enhances NGF-induced neurite outgrowth and morphological complexity. We conclude that MOCA regulates N-cadherin-mediated cell-cell adhesion and neurite outgrowth.

Co-induction of growth-associated protein GAP-43 and neuronal nitric oxide synthase in the cochlear nucleus following cochleotomy

In adult animals, cochlear lesioning leads to a reactive synaptogenesis with a reemergence of growth-associated protein, GAP-43, in the auditory brainstem nuclei. In addition, nitric oxide (NO) is also implicated in synaptogenesis. Three isoforms of nitric oxide synthase (NOS) responsible for generating NO have been identified and, in neurons, the predominant isoform is neuronal NOS (nNOS). Studies in visual or olfactory systems have found that the NOS expression often correlates with periods of axonal outgrowth and synapse formation; whether NO plays a similar role in the auditory brainstem needs to be examined. In the present study, a unilateral cochleotomy was performed in adult mice to examine the relationship between the reemergence of GAP-43 and the expression pattern of nNOS. Following surgery, GAP-43 re-emerged in the ipsilateral anterior ventral cochlear nucleus (AVCN) and the immunoreactivity reached a climax around postoperative day (POD) 8; the same expression pattern as that reported in the previous literature is the indicator of synaptogenesis. As for the nNOS immunoreactivity, a dramatic redistribution from a mostly cytoplasmal to a predominantly membranous localization in the ipsilateral AVCN was found especially at POD 4. A similar redistribution pattern in the ipsilateral AVCN for the N-methyl-D-aspartate (NMDA) receptor was also observed at POD 4, corresponding to the fact that the activation of nNOS is coupled to calcium influx via the NMDA-receptor. Furthermore, the expression of cyclic guanosine monophosphate (cGMP) is an indicator for activity of soluble guanylyl cyclase (sGC), the substrate of NO, which reveals the target area of NO. Therefore, cGMP immunoreactivity was also examined and an obvious increase of cytoplasmal cGMP expression was observed around POD 4. Accordingly, it is suggested that nNOS activity correlates closely with the reactive synaptogenesis following a cochleotomy. Further evidence is shown by the results of fluorescent double staining; nNOS-positive cells were surrounded by GAP-43 labeled regions that appeared to be presynaptic boutons, and the vast majority of nNOS-positive cells also expressed cGMP. The former result indicates that, after surgery, there should be new terminal endings projecting onto the nNOS-positive cells in the AVCN. Furthermore, the latter result suggests a possible role of an autocrine mediator for nNOS in the AVCN.

Induction of VX2 carcinoma in rabbit liver: comparison of two inoculation methods

Direct injection of VX2 cell suspension into the liver is simple and widely used. Implantation of a fragment of VX2 tumour into the liver using a surgical technique has also been developed in the last decade. In this study, we compared these two methods in order to find a better modality for establishing VX2 liver mass. Forty rabbits, each weighing 2.8-3.2 kg, were divided into two groups, 20 rabbits in each. In Group 1, a tumour cell suspension containing 1 x 10(6) cells in a volume of 0.1 ml, was injected slowly into the liver parenchyma using a 27-gauge needle during laparotomy. In Group 2, a 1 mm(3) fragment of VX2 carcinoma was inoculated into the sub-capsule of the left anterior lobe of the liver. In Group 1, three rabbits showed no tumour growth and 10 rabbits showed evidence of leakage and tumour seeding outside of the liver. In Group 2, all but one rabbit showed tumour growth and none showed evidence of tumour seeding. The leakage rates were 50% and 0% for Group 1 and Group 2, respectively. Overall, the success inoculation rate was 35% for Group 1 and 95% for Group 2. In conclusion, to create the VX2 liver tumour model in rabbits, direct implantation of VX2 tumour fragment into the liver achieved better results than injecting cell suspension of VX2 tumour into the liver.

Trends in prescribing proton pump inhibitors in Taiwan: 1997 - 2000

OBJECTIVE

The prescribing of proton pump inhibitors (PPIs) had increased greatly in recent years worldwide. Aim of our study was to analyze the utilization patterns of PPIs within the National Health Insurance program in Taiwan from 1997 - 2000.

MATERIAL AND METHOD

The systemic sampling data-sets from the National Health Insurance Research Database served as data sources. Units of measurement for PPIs were numbers of prescription items and defined daily doses (DDDs). To estimate the proportion of the population treated daily with PPIs, numbers of DDDs per 1,000 inhabitants per day were calculated. In order to realize the role of PPIs in treating Helicobacter pylori-related disorders, we also analyzed various combined prescriptions of PPIs with amoxicillin, clarithromycin, metronidazole, tetracycline and bismuth.

RESULTS

In the study period, PPI prescriptions increased nearly 2-fold at the outpatient sector and more than 3-fold at the inpatient sector. Men received more PPI prescriptions, as a whole, than women. Most PPIs were prescribed at the outpatient sector: 93.9% in 1997, 92.3% in 1998, 90.4% in 1999 and 87.3% in 2000. The numbers of DDDs per 1,000 inhabitants per day for all kinds of PPIs were 0.59, 0.78, 1.07, and 1.13 from 1997 - 2000, respectively. While the percentage of monotherapy increased from 63.6% in 1997 to 75.5% in 2000, the combination therapies did not experience a rapid and sustained growth. Among the combination therapies, PPI + amoxicillin + metronidazole and PPI + amoxicillin were popular in 1997 and 1998, but triple therapy with PPI + amoxicillin + clarithromycin predominated in 1999 and 2000.

CONCLUSIONS

Despite increasing use, prescribing volumes of PPIs in Taiwan were far fewer than those in other developed countries. Treatment of Helicobacter pylori-related disorders in Taiwan followed universal standard.

Analysis of marker or complex chromosomal rearrangements present in pre- and post-natal karyotypes utilizing a combination of G-banding, spectral karyotyping and fluorescence in situ hybridization

The significance of complex chromosomal rearrangements presents a diagnostic dilemma. In the past, the use of G-banding coupled with fluorescence in situ hybridization (FISH) has been the standard approach. The recent development of spectral karyotyping (SKY) and multicolor FISH (M-FISH) has resulted in an increased accuracy of identification of marker or other complex chromosomal rearrangements. However, owing to the additional cost and time associated with SKY or M-FISH, and the restricted availability of such imaging facilities in many centers, it is not feasible to perform these procedures routinely on every sample. In addition, the identification of an aberration by SKY or M-FISH will often require confirmation by FISH. A practical approach is needed to take advantage of the complementary strengths of each method. In our center we utilize an algorithm that dictates the use of routine G-banding for the initial preliminary evaluation of a patient, followed by SKY characterization if marker chromosomes or complex translocations are detected by the G-banding analysis. According to this algorithm, FISH is used to verify the results once the origin of the abnormal chromosome has been determined by SKY. To demonstrate the effectiveness of this algorithm, we have analyzed both amniocyte and lymphocyte slides, using a combination of G-banding, SKY, and FISH. Our results confirm that an algorithm which selectively uses SKY or M-FISH will provide an efficient and improved method for pre- and post-natal chromosomal analysis.

Increased vulnerability of auditory system to noise exposure in mdx mice

OBJECTIVES

Dystrophin is a cytoskeletal protein mainly found just beneath the sarcolemma. Lack of dystrophin is known to be the cause of Duchenne muscular dystrophy (DMD). Other tissues, including the brain, retina, and cochlear hair cells, also express dystrophin. Recently, a gene (Xp21.2) associated with sensorineural hearing impairment has been mapped within the localization site for dystrophin in two families. Thus, it is reasonable to assume that dystrophin may play a role in auditory function. However, animal studies have produced conflicting results.

STUDY DESIGN

An attempt was made to clarify the differences between the auditory systems of dystrophin-deficient mdx mice and control B-10 mice by exposure to noise.

METHODS

In the present study, mdx mice and B-10 mice were used. Animals were exposed daily to noise for 1 month, and their auditory functions were evaluated by recording the brainstem auditory evoked potentials (BAEPs).

RESULTS

Before noise exposure, the mdx mouse demonstrated normal BAEP threshold when compared with the B-10 mouse. After 1 month of noise exposure, the B-10 mouse showed no apparent change in hearing threshold and BAEP latencies. In contrast, significantly increased hearing threshold and prolonged BAEP peak and interpeak latencies were observed in the mdx mouse after noise exposure.

CONCLUSIONS

These results indicate that the mdx mice are more vulnerable to noise damage. This involves not only the peripheral auditory system, but also the brainstem central auditory pathway. Therefore, a significant role for dystrophin in the auditory system, especially under noise stress, is suggested.

Administration of chinese herbal medicines facilitates the locomotor activity in dystrophin-deficient mice

The purpose of this study was to access the effects of chinese herbal medicines on Duchenne muscular dystrophy (DMD). We use dystrophin-deficient mice (mdx), an animal model of DMD, to evaluate the effect of chinese herbal medicines on locomotor activity. The consumption of water for each mouse was controlled during the three-month experimental session. Each mouse was allowed to drink 3 ml water with or without herbal medicines daily for three months. The estimated intake of chinese herbal medicine in adult mdx mouse with 30 g weight is 100 mg/kg per day, close to a dose used in human. The locomotor activity of the mdx mice was measured every month. Monitoring the locomotor activity of mdx mice after three-month administration of chinese herbal medicines, the results showed that liu-wei-di-huang-wan (LDW) and san-lin-pai-tsu-san (SPS) can facilitate locomotor activity with the parameters of horizontal activity, total distance, number of movements, movement time, vertical activity, number of vertical movements, vertical movement time, stereotypy, number of stereotyped movements, and stereotyped movement time. These results suggest that either LDW or SPS can act as a potent herbal medicine for the pharmacological treatment of DMD patients.

An initial assessment of the feasibility and effectiveness of implementing diabetes shared care system in Taiwan--some experiences from I-Lan County

Diabetes is the fifth leading cause of death in Taiwan and the burden of suffering is still increasing. Building a comprehensive and efficient health care system is crucial to improve the outcome of the diabetics. We implemented the first diabetes shared care system of Taiwan in I-Lan County since August 1996 under the support of Department of Health, the Executive Yuan. This county-wide system was named 'Lan-Yang Diabetes Shared Care System' by the regional steering committee. Regional guidelines for diabetes management were developed after extensive discussion. A multidisciplinary diabetes care team was organized through a training and certification process. Registered patients held diabetes passports to keep clinical record. Physicians of the system use shared referral protocols and sheets. By the end of June 1999, 99 medical professionals had completed their training for diabetes shared care and been certified. The shared care system awarded 26 clinics to hang the lamp signs with the system logo to make them distinguishable. Such clinics have now been available throughout 12 townships in I-Lan County. The number of registered patients carrying diabetes passport increased to 3484 and there was a community-based patient group in every township of I-Lan County. The amount of continuing diabetes clinical training delivered by the specialists to the primary care physicians and non-physician professionals increased to 1681 person-hours per year. The proportion of registered patients undertaking fundus examination within 1 year increased to 30.9%, checking urine micro-albumin to 28.0% and checking HbA(1c) 72.8%, respectively. Mean HbA(1c) value decreased from 8.7% in the first year to 7.9% in the third year. Our study showed that under the co-ordination by regional health bureau with integration of different levels of medical facilities, governmental sectors and non-governmental community resources, the diabetes shared care model is feasible in Taiwan. Through its implementation, quality of regional diabetes care has achieved preliminary improvement.

p53 and p21 expression in precancerous lesions and carcinomas of the uterine cervix: overexpression of p53 predicts poor disease outcome

OBJECTIVES

Abnormal expression of the p53 and p21(waf1/cip1) tumor suppressor genes has been observed in a variety of human tumors, but little is known about its expression during cervical tumorigenesis. To identify the potential implications of both genes in the development of cervical carcinoma and explore the clinical importance of changes in gene expression, we assessed the levels of both proteins in precancerous lesions and carcinomas of the cervix.

METHODS

In our study, 10 low-grade squamous intraepithelial lesions (LSIL), 35 high-grade squamous intraepithelial lesions (HSIL), 12 microinvasive carcinomas, and 103 invasive carcinomas were evaluated. The expression of p53 and p21 was studied by immunohistochemistry using monoclonal antibodies specific for these proteins.

RESULTS

p21 was expressed in all samples of normal epithelium, LSIL, and HSIL, and the mean values of expression were 50.3, 42.5, and 44.5%, respectively. Conversely, the expression of p21 was significantly reduced in microinvasive (30.7%) and invasive carcinomas (9.9%). p53 nuclear staining was not detected in normal epithelium samples or LSILs, while 4 (11.4%) of 35 HSILs, 1 (8.3%) of 12 microinvasive carcinomas, and 38 (36.9%) of 103 invasive carcinomas were positive for p53. Compared with the results of the control group, precancerous lesions, and microinvasive carcinoma, the mean value of p53 expression (4.8%) in invasive carcinoma was significantly higher. Furthermore, p53 overexpression was significantly associated with advanced stage of the tumor (P < 0.001) [16/67 (23.9%) stage I, 15/28 (53.6%) stage II, and 7/8 (87.5%) stage III/IV]. In univariate analysis, p53 overexpression was a significant predictor of poor survival, whereas it had no independent influence on overall survival using the Cox regression method. Our data also revealed that no association between p53 immunostaining and p21 expression was found.

CONCLUSIONS

The trend of reduced p21 expression in microinvasive and invasive carcinomas suggests that p21 may play a tumor-suppressor function in neoplastic transformation in cervical epithelium and inactivation of p21 may be an early event in cervical carcinogenesis. Our results indicated that p53 overexpression was a significant predictor of poor disease outcome in univariate analysis. Moreover, significantly increased expression of p53 in advanced-stage cervical carcinoma implies that inactivation of p53 is associated with tumor progression. Finally, this study further supports the notion that induction of p21 expression can be regulated in a p53-independent manner.

Acute myocardial infarction after upper gastrointestinal gastroscopy

We describe a patient with gastric ulcer confirmed by upper gastrointestinal endoscopy who developed an acute Q wave myocardial infarction involving both the anterior and inferior wall shortly after the procedure. This life-threatening complication of gastroendoscopy was clearly demonstrated through studies of electrocardiogram, cardiac enzymes, echocardiogram and cardiac catherterization. We suggest that preventive measures should be implemented so that endoscopy can be performed under optimal conditions, especially for elderly patients with history of heart disease.

Concomitant prescription of non-steroidal anti-inflammatory drugs and antacids in the outpatient setting of a medical center in taiwan: a prescription database study

OBJECTIVE

Although antacids were ineffective in preventing serious gastrointestinal complications caused by non-steroidal anti-inflammatory drugs (NSAIDs), many physicians in Taiwan still prescribe antacids concomitantly with NSAIDs. A survey of an outpatient prescription database was performed to measure the extent of such a combination and to explore its associated factors.

METHODS

One month of the outpatient prescription data in the polyclinic of a medical center in Taiwan served to estimate the frequency of concomitant antacid prescription with NSAIDs. The age of patients, duration of NSAID prescriptions, concomitant prescription of corticosteroid or ulcer-healing drugs, and inter-departmental variations were compared between the NSAID prescriptions with and without antacids.

RESULTS

Antacids were present in 87.3% of prescriptions with NSAIDs but only in 34.4% of prescriptions without NSAIDs (P<0.001). The prescription of antacids was significantly associated with the prescription of NSAIDs. The age of patients and duration of NSAID prescriptions did not influence the co-prescription of NSAIDs and antacids. Significant inter-departmental variations were noted in which the surgeons and orthopedic doctors tended to co-prescribe antacids with NSAIDs more often than the internists.

CONCLUSION

The physicians in Taiwan tended to prescribe NSAIDs together with antacids. The rationality of this co-prescription deserves further investigation.

Association analysis for dopamine D2 receptor Taq1 polymorphism with P300 event-related potential for normal young females

P300 has been demonstrated abnormal for a variety of neuropsychiatric disorders, and heritability has been proposed. We analyzed the event-related potentials for three DRD2 genotype groups in 134 normal young females. The results demonstrate that there is no association for DRD2 genotype and P300 components. Our negative findings in normal subjects suggest association demonstrated for P300 latency and the DRD2 allele may be disease dependent.

Novel SNP at the common primer site of exon IIIa of FGFR2 gene causes error in molecular diagnosis of craniosynostosis syndrome

Most mutations in Crouzon, Pfeiffer, and Apert syndromes are in the extracellular, third immunoglobulin-like domain and adjacent linker regions (exons IIIa and IIIc) of the fibroblast growth factor receptor 2 (FGFR2) gene. Using the published primers for PCR, a patient with Crouzon syndrome was found to be homozygous for a mutation that results in a Q289P amino acid substitution in FGFR2. Two additional patients; one with Apert syndrome and P253R mutation, the other with Pfeiffer syndrome and S267P mutation, also appeared to be homozygous. Using a new primer located 146 bp 5' of exon IIIa for PCR followed by sequencing revealed an A to G polymorphism at -62 [corrected] position of exon IIIa. All three patients were heterozygous for both the mutation and the polymorphism. These results indicate that the polymorphism and the mutation are not on the same chromosome. The single nucleotide polymorphism is located at the second to the last base of the 3' end of the published primer. This primer mismatch caused the failure of amplification of the normal chromosome and thus, the apparent homozygosity. The frequency of this novel polymorphism was determined to be 0.03 by studying 326 chromosomes from the general population. We propose that a new primer should be used for mutational analysis of exon IIIa of FGFR2 to avoid misdiagnosis caused by primer mismatch.

Severe lactic acidosis caused by a novel frame-shift mutation in mitochondrial-encoded cytochrome c oxidase subunit II

We report the first frame-shift truncation mutation in a mitochondrial DNA (mtDNA)-encoded subunit II of cytochrome c oxidase (COXII). The mutation was identified by temporal temperature gradient gel electrophoresis (TTGE) followed by direct DNA sequencing in an infant who died at 12 days of age following a course of apnea, bradycardia, and severe lactic acidosis. The patient had a twin brother who died at two days of age of similar course. The mutation, 8042delAT, produced a truncated protein that was 72 amino acids shorter than the wild type protein. The mutant protein, missing one third of the amino acid residues at the C-terminal essential for hydrophilic interaction with cytochrome c, ligand binding to CuA and Mg, and the formation of proton and water channels, apparently has devastating effects on mitochondrial respiratory function.

Antibiotic usage in primary care units in Taiwan after the institution of national health insurance

To understand antibiotic usage in primary care units in Taiwan after the institution of national health insurance, we collected all prescriptions for one week in March each year from 1996 to 1999 from out-patient clinics of randomly sampled public health stations located in various parts of Taiwan. We sampled 114 health stations with 40,891 patient-visits and 68,386 diagnoses made in 1996; 154 health stations were sampled with 53,992 patient-visits and 99,466 diagnoses in 1997; 166 health stations were sampled with 49,112 patient-visits and 96,161 diagnoses in 1998; and 162 health stations were sampled with 46,976 patient-visits and 93,641 diagnoses in 1999. The percentages of total patient-visits that resulted in antibiotic treatment were 14.2%, 12.5%, 14.1% and 13.0% in the four time periods, respectively. Among patient-visits, patient group under the age of 11 received the highest percentage of antibiotic treatment. Common cold was the most frequent diagnosis for which antibiotic was prescribed during the four time periods, accounting for 32.3% of total antibiotic prescriptions. Among patients with the diagnosis of common cold, 31.3% received antibiotic treatment, and the highest figure was among pediatric patients (<16 year of age). Penicillins, cephalosporins and macrolides were the most commonly prescribed classes of antibiotics. They accounted for 35.4%, 26.5% and 21.6% of all prescribed antibiotics in these four study periods. From this study, it was found that, after institution of the national health insurance system, antibiotics are still very commonly used in primary care units in Taiwan and still seem to be overused.