Distribution and functional characterization of human Nav1.3 splice variants

The focus of the present study is the molecular and functional characterization of four splice variants of the human Nav1.3 alpha subunit. These subtypes arise due to the use of alternative splice donor sites of exon 12, which encodes a region of the alpha subunit that resides in the intracellular loop between domains I and II. This region contains several important phosphorylation sites that modulate Na+ channel kinetics in related sodium channels, i.e. Nav1.2. While three of the four Nav1.3 isoforms, 12v1, 12v3 and 12v4 have been previously identified in human, 12v2 has only been reported in rat. Herein, we evaluate the distribution of these splice variants in human tissues and the functional characterization of each of these subtypes. We demonstrate by reverse transcriptase-polymerase chain reaction (RT-PCR) that each subtype is expressed in the spinal cord, thalamus, amygdala, cerebellum, adult and fetal whole brain and heart. To investigate the functional properties of these different splice variants, each alpha subunit isoform was cloned by RT-PCR from human fetal brain and expressed in Xenopus oocytes. Each isoform exhibited functional voltage-dependent Na+ channels with similar sensitivities to tetrodotoxin (TTX) and comparable current amplitudes. Subtle shifts in the V 1/2 of activation and inactivation (2-3 mV) were observed among the four isoforms, although the functional significance of these differences remains unclear. This study has demonstrated that all four human splice variants of the Nav1.3 channel alpha subunit are widely expressed and generate functional TTX-sensitive Na+ channels that likely modulate cellular excitability.

A pilot-scale photocatalyst-membrane hybrid reactor: performance and characterization

We developed and tested a pilot-scale photocatalyst-membrane hybrid reactor for water treatment. The performance of the pilot-scale reactor was evaluated by monitoring the degradation efficiency of several organic pollutants and the membrane suction pressure at different operating conditions. The concentration of humic acids rather increased in the initial period of UV illumination and then decreased gradually, which could be ascribed to the photoinduced desorption of humic acids from the TiO2 surface. The decoloring rate of methylene blue was faster than that of rhodamine B, whereas the order of mineralization rates of the dyes was reversed. 4-chlorophenol of 100 ppb was fully degraded under UV irradiation in 2 hours, which suggests that this hybrid reactor would be more suitable in removing micropollutants in water. The reactor was operated with either continuous or intermittent suction mode. In a continuous suction mode, the formation of TiO2 cake layers on the membrane surface occurred and caused a substantial increase in suction pressure. However, no further fouling (or suction pressure build-up) took place with an intermittent suction mode with the 9-min suction and 3-min pause period. The photocatalyst-membrane hybrid reactor system developed in this study could be an attractive option for controlling micropollutants in water.

Parental exposure to polycyclic aromatic hydrocarbons and the risk of childhood brain tumors: The SEARCH International Childhood Brain Tumor Study

Experimental evidence suggests that parental exposure to polycyclic aromatic hydrocarbons (PAH), which occurs primarily through tobacco smoke, occupational exposure, and air pollution, could increase the risk of cancer during childhood. Population-based case-control studies carried out in seven countries as part of the SEARCH Program compared data for 1,218 cases of childhood brain tumors and 2,223 controls (1976-1994). Parental occupational exposure to PAH during the 5-year period before birth was estimated with a job exposure matrix. Risk estimates were adjusted for child's age, sex, and study center. Paternal preconceptional occupational exposure to PAH was associated with increased risks of all childhood brain tumors (odds ratio (OR) = 1.3, 95% confidence interval: 1.1, 1.6) and astroglial tumors (OR = 1.4, 95% confidence interval: 1.1, 1.7). However, there was no trend of increasing risk with predicted level of exposure. Paternal smoking alone (OR = 1.4) was also associated with the risk of astroglial tumors in comparison with nonsmoking, non-occupationally-exposed fathers. Risks for paternal occupational exposure were higher, with (OR = 1.6) or without (OR = 1.7) smoking. Maternal occupational exposure to PAH before conception or during pregnancy was rare, and this exposure was not associated with any type of childhood brain tumor. This large study supports the hypothesis that paternal preconceptional exposure to PAH increases the risk of brain tumors in humans.

Computer-assisted treatment planning and analysis

The Invisalign orthodontic system (Align Technology, Inc, Santa Clara, CA) is a series of clear removable appliances that is worn by a patient to correct malocclusions. Introduced in 1999, it has been applied to successfully correct an increasingly wide variety of malocclusions. Part of the success of the system is because of the innovative technologies inherent in the design of the appliances. During the development of the system, many challenges and issues needed to be overcome to realize the product. Many of these issues were not specific to Invisalign, and represented general problems in the area of computer-aided orthodontics. The general problems of developing a virtual model of a patient's dentition appropriate for use in orthodontics, performing a treatment plan on a virtual dentition model, and analyzing how accurately the virtual treatment plan executed in the patient's mouth are presented.

Validation of Align Technology's Treat IIITM digital model superimposition tool and its case application

OBJECTIVE

An assessment of the efficacy and accuracy of three-dimensional computer-based predictive orthodontic systems requires that new methods of treatment analysis be developed and validated.

DESIGN

Invisalign is a digitally fabricated, removable orthodontic appliance that has been commercially available since 1999. It is made up of two main components: 1) computerized graphical images of a patient's teeth moving through a series of stages from initial to final position; 2) pressure formed clear plastic appliances made from stereolithography models of the images in the first component.

SETTING AND SAMPLE POPULATION

The manufacturer of Invisalign (Align Technology, Inc.) has created a software tool that can be used to superimpose digital models to evaluate treatment outcomes in three dimensions. Using this software, research was conducted to determine if a single operator could repeatedly superimpose two identical digital models using 12 selected points from the palatal rugae over 10 trials. The tool was then applied to one subject's orthodontic treatment. EXPERIMENT VARIABLES: The output from this tool includes rotations, translations and morphological changes. For this study, translations and rotations were chosen.

RESULTS

The results showed that the digital superimposition was reproducible, and that after multiple trials, the superimposition error decreased. The average error in x, y, z, Rx, Ry and Rz after 10 trials was determined to approach approximately 0.2 mm in translation and less than 1 degree in rotation, with a standard deviation of 0.15 mm and 0.7 mm, respectively. The treatment outcome from a single Invisalign-treated bicuspid extraction case was also evaluated tooth-by-tooth in x, y, z, Rx, Ry and Rz dimensions.

CONCLUSION

Using the palate, as a stable reference seemed to work well and the evaluation of the single case showed that many, but not all, of the planned movements occurred.

Human kinesin superfamily member 4 is dominantly localized in the nuclear matrix and is associated with chromosomes during mitosis

In a previous study, we identified the human counterpart of murine kinesin superfamily member 4 (KIF4), a microtubule-based motor protein [Oh, Hahn, Torrey, Shin, Choi, Lee, Morse and Kim (2000) Biochim. Biophys. Acta 1493, 219-224]. As an initial step to understand the function(s) of human KIF4, its subcellular localization in HeLa cells was examined by using immunocytochemical and subcellular fractionation methods, and it was found that most KIF4 is localized in the nucleus. Since murine KIF4 is known to transport cytoplasmic vesicles, dominant nuclear localization of the human counterpart was somewhat surprising. Subsequent subnuclear fractionation revealed predominant association of KIF4 with the nuclear matrix. These results clearly indicate that human KIF4 is, at least, a nuclear protein. In further confirmation of this conclusion, the hexapeptide PKLRRR (amino acids 773-778) in the molecule was found to function as a nuclear localization signal. During the mitotic phase of the cell cycle, human KIF4 was associated with the chromosomes, suggesting that human KIF4 might be a microtubule-based mitotic motor, with DNA as its cargo.

Chronic hepatitis: in vivo proton MR spectroscopic evaluation of the liver and correlation with histopathologic findings

PURPOSE

To correlate the in vivo hydrogen 1 ((1)H) magnetic resonance (MR) spectroscopic features of the chronic hepatitis-involved liver with the histopathologic stages of fibrosis.

MATERIALS AND METHODS

Seventy-five patients with chronic hepatitis were examined with (1)H MR spectroscopy, which was performed in the right hepatic lobe. The peak areas of glutamine and glutamate complex (Glx), phosphomonoesters (PME), glycogen and glucose complex (Glyu), and lipid were measured on the liver spectra. The histopathologic features were correlated with the in vivo (1)H MR spectroscopic findings at each stage of chronic hepatitis. Fifteen healthy volunteers also were included as a control group.

RESULTS

(1)H MR spectroscopy depicted Glx, PME, Glyu, and lipid in all livers. In the normal livers, the calculated mean (+/- SD) relative metabolite-to-lipid ratios of Glx, PME, and Glyu were 0.14 +/- 0.04, 0.03 +/- 0.01, and 0.21 +/- 0.04, respectively. The mean value of each metabolite-to-lipid ratio was significantly different between all stages of chronic hepatitis, and with the exception of the mean ratio at the interval between stages 0 and 1 (P > .05), the mean value increased significantly with increasing stage (P < .05). A pronounced peak was demonstrated at 3.9-4.1 ppm at (1)H MR spectroscopy of all stages of chronic hepatitis except stage 0.

CONCLUSION

The increased Glx, PME, and Glyu levels relative to the lipid content with chronic hepatitis indicated the severity of fibrosis and thus were concordant with the histopathologic stages. In vivo (1)H MR spectroscopy might be a substitute for liver biopsy in the diagnosis and staging of chronic hepatitis.

Genes expressed during early stages of rice infection with the rice blast fungus Magnaporthe grisea

summary A system-wide approach was adopted to further elucidate mechanisms regulating disease outcome between rice and the fungal pathogen Magnaporthe grisea. First, a cDNA library was constructed from M. grisea infected rice at 48 h post-inoculation. The 5' end-sequencing of 619 randomly selected clones revealed 359 expressed sequence tags (ESTs) that had not previously been described. A total of 124 from 260 ESTs with high and moderate similarity scores, based on BlastX, were organized into categories according to their putative function. The largest category of sequences (21%) contained stress or defence response genes. Eleven per cent of identified ESTs were redundant. In a second approach, differential hybridization analysis of the cDNA library using high-density filters resulted in the identification of novel genes and previously characterized M. grisea genes, including several that had previously been implicated in the infection process. A survey of up-regulated cDNA clones revealed clone 29003, which corresponded to the rice peroxidase POX22.3. This gene is known to be expressed in rice upon infection with Xanthomonas oryzae pv. oryzae, the bacterial blight pathogen. Importantly, this approach demonstrates the utility of gene discovery, through ESTs, for revealing novel genes in addition to those previously characterized as being potentially implicated in host-pathogen interactions.

The predictive parameters of erythropoietin hyporesponsiveness in patients on continuous ambulatory peritoneal dialysis

BACKGROUND

The present study was aimed at investigating the predictive parameters of erythropoietin (epoetin) hyporesponsiveness in patients on continuous ambulatory peritoneal dialysis (CAPD).

METHODS

We studied 40 patients with end-stage renal disease who had been receiving CAPD for at least 6 months and epoetin therapy for at least more than 2 months. Pearson's simple correlation and multiple stepwise linear regression analysis was used to discover what parameter can predict epoetin resistance. We expressed epoetin resistance index (ERI) as weekly epoetin dose/hematocrit/body weight'. The dose of epoetin is titrated by about 25% every 2 to 4 weeks to maintain a target hematocrit level between 33% and 36%.

RESULTS

We analyzed the relationship between ERI and other predictive parameters by Pearson's correlation. These results showed ERI has a statistically significant correlation with transferrin saturation (TS) (r = -0.327, p = 0.042), total weekly Kt/Vurea (r = -0.423, p = 0.018), serum albumin level (r = -0.458, p = 0.003), normalized protein catabolic rate (nPCR) (r = -0.479, p = 0.006), normalized protein equivalent of total nitrogen appearance (nPNA) (r = -0.488, p = 0.005) and serum C-reactive protein (CRP) (r = 0.332, p = 0.036). Regression analysis was performed using stepwise linear regression for multiple variables to discover the most independent variable which is correlated with ERI. ERI was entered as a dependent variable, whereas the other parameters (age, duration of peritoneal dialysis, serum albumin level, CRP, serum ferritin, total weekly Kt/Vurea, nPCR, nPNA, serum iPTH, serum aluminium, TS) were entered as independent variables. This analysis showed CRP is the most significant variable and, if CRP is excluded, nPNA is the significant variable. CRP has a statistically significant correlation with serum albumin level (r = -0.418, p = 0.007) and total weekly Kt/Vurea (r = -0.366, p = 0.043). High CRP group has more increased level of ERI (p < 0.05), age (p < 0.05) and serum creatinine level (p < 0.05) than normal control, but more decreased level of serum albumin (p < 0.01) and serum iron levels (p < 0.05).

CONCLUSION

These results indicate that CRP is the most important predictor of epoetin hyporesponsiveness.

A simple rule for classification of polychlorinated dibenzo-p-dioxin congeners on the basis of IR frequency patterns

The IR spectra of 76 dioxin congeners with zero to eight chlorines have been calculated by the DFT (B3LYP) method. Close inspection of the calculated spectra provides a simple rule for IR spectral analysis in polychlorinated dibenzo-p-dioxins (PCDDs). All congeners with a common structural motif of chlorine substitution in either of two benzene rings share the same main IR frequency, and the chlorination of one ring has little influence on the vibrational frequencies of the other ring. As a result, the main ring vibrational frequencies of all dioxin congeners could be classified into 10 groups according to the chlorine substitution pattern. This simplifies the complex IR spectral analysis of PCDDs to identifying two main peaks in essence, each of which corresponds to either of two chlorinated benzene rings. The systematic trend originates from the mass effect of the substituted chlorines. The C-H bending (in plane) character in the ring skeleton vibration mode is affected in quite different ways, depending on whether the chlorine is substituted on longitudinal or lateral positions. In particular, when all the lateral positions (2, 3, 7, 8) are chlorinated in PCDDs, the vibrational frequency of a b(1u) mode (or its analogues in other symmetry) gives a characteristic IR peak around 1392 cm(-1). This peak is unique to all toxic congeners and could be used as an indicator for them.

Lysophosphatidylcholine derived from deer antler extract suppresses hyphal transition in Candida albicans through MAP kinase pathway

A family of 2-lysophosphatidylcholines (lyso-PCs) was isolated from deer antler extract, guided exclusively by hyphal transition inhibitory activity in Candida albicans. Structural determination of the isolated lyso-PCs by spectroscopic methods, including infrared spectroscopy, 1H nuclear magnetic resonance (NMR), 13C NMR, 2D correlation spectroscopy NMR, fast atom bombardment mass spectrometry and tandem mass spectrometry, confirmed that the natural products were composed of at least four different lyso-PCs varying in fatty acid moiety at the sn-1 position of the glycerol backbone. The major lyso-PCs were confirmed as 1-stearoyl-, 1-oleoyl-, 1-linoleoyl- and 1-palmitoyl-2-lyso-sn-glycero-3-phosphatidylcholines. Lyso-PC specifically suppressed the morphogenic transition from yeast to hyphae in C. albicans, without affecting the growth of either yeast or hyphae. Lyso-PC exerted hyphal transition that suppressed activity in the broad spectrum of the Candida species, such as C. albicans, Candida krusei, Candida guilliermondii and Candida parapsilosis. Northern analysis indicated that the suppression was mediated through the mitogen-activated protein kinase pathway.

Visible light-induced degradation of carbon tetrachloride on dye-sensitized TiO2

This study investigated an application of TiO2 photocatalyst sensitized with tris(4,4'-dicarboxy-2,2'-bipyridyl)ruthenium-(II) complex to CCl4 degradation under visible light irradiation. By injecting electrons from the photoexcited sensitizer to the conduction band, the sensitized TiO2 degraded CCl4 under the irradiation of lambda > 420 nm. The quantum yield of CCl4 dechlorination was about 10(-3). The dechlorination rate of CCl4 was reduced in the presence of dissolved O2 due to its competition for conduction band electrons. The photolysis rate was dependent on pH due to the strong pH dependence of the sensitizer adsorption on TiO2 surface with a maximum degradation rate achieved at pH approximately 3. A two-site Langmurian model successfully described the adsorption of the sensitizer on TiO2 particles. The monolayer coverage was achieved at the added sensitizer concentration of 10 microM at [TiO2] = 0.5 g/L. However, the photolysis rate of CCl4 showed a maximum at a sensitizer surface coverage of 0.3 monolayer. Since the photoinduced electron injection gradually depleted active sensitizer molecules on TiO2, sacrificial electron donors to regenerate the sensitizer were sought. 2-Propanol as an electron donor was efficient in the present RuIIL3/TiO2/CCl4 system, which showed no sign of deceleration in the dechlorination rate up to 6 h of irradiation.

Cyberostracism: effects of being ignored over the Internet

Ostracism is such a widely used and powerful tactic that the authors tested whether people would be affected by it even under remote and artificial circumstances. In Study 1, 1,486 participants from 62 countries accessed the authors' on-line experiment on the Internet. They were asked to use mental visualization while playing a virtual tossing game with two others (who were actually computer generated and controlled). Despite the minimal nature of their experience, the more participants were ostracized, the more they reported feeling bad, having less control, and losing a sense of belonging. In Study 2, ostracized participants were more likely to conform on a subsequent task. The results are discussed in terms of supporting K. D. Williams's (1997) need threat theory of ostracism.

Cyberostracism: effects of being ignored over the Internet

Ostracism is such a widely used and powerful tactic that the authors tested whether people would be affected by it even under remote and artificial circumstances. In Study 1, 1,486 participants from 62 countries accessed the authors' on-line experiment on the Internet. They were asked to use mental visualization while playing a virtual tossing game with two others (who were actually computer generated and controlled). Despite the minimal nature of their experience, the more participants were ostracized, the more they reported feeling bad, having less control, and losing a sense of belonging. In Study 2, ostracized participants were more likely to conform on a subsequent task. The results are discussed in terms of supporting K. D. Williams's (1997) need threat theory of ostracism.

Cross-resistance of a chlorpyrifos-methyl resistant strain of Oryzaephilus surinamensis (Coleoptera: Cucujidae) to fumigant toxicity of essential oil extracted from Eucalyptus globulus and its major monoterpene, 1,8-cineole

The fumigant toxicities of eucalyptus essential oil and 1,8-cineole, the major component of eucalyptus oil, were tested against a chlorpyrifos-methyl resistant strain and a reference strain of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.). The resistant strain showed 1.9- and 2.2-fold higher tolerance against essential oil and 1,8-cineole fumigation toxicity, respectively, relative to the susceptible strain. The increased tolerance for the essential oil may be the result of cross-resistance. The resistance mechanisms in the resistant strain are discussed in relation to elevated detoxifying enzymes such as cytochrome P450 and esterases.

Molecular characterization of human SUR2-containing K(ATP) channels

The distribution of human sulfonylurea receptor-2 (SUR2)-containing K(ATP) channels was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR). mRNA for SUR2B was detected in a variety of tissues including brain, skeletal, cardiac and smooth muscle, whereas SUR2A message was restricted to cardiac and skeletal muscle. An additional splice variant of SUR2 that lacked exon 17 was also identified by RT-PCR in tissues expressing both SUR2A and SUR2B or SUR2B alone. Quantification of RNA for SUR2 exon 17+ and SUR2 exon 17- splice variants using real-time Taqman PCR indicated differential levels of expression in brain, kidney, skeletal muscle, heart and small intestine. Interestingly, the SUR2 exon 17+ variant is the major species expressed in all tissues examined in this study. Each of the SUR2 splice variants transiently expressed with the inward rectifier Kir 6.2 formed functional K(ATP) channels in HEK 293 cells as assessed either by changes in DiBAC(4)(3) fluorescence responses or glyburide-sensitive whole cell currents. Collectively, our findings demonstrate that various SUR2 splice variants have distinct expression patterns and can form functional K(ATP) channels.

Identification of the human homologue of mouse KIF4, a kinesin superfamily motor protein

A combination of RT-PCR with cDNA library screening led to the identification of the human homologue of murine KIF4 (mKIF4), a microtubule-based motor protein. The nucleotide sequence of human KIF4 (hKIF4) comprised part of the 5' untranslated region (UTR), a long open reading frame (ORF) encoding 1232 amino acids, and the entire 3' UTR. Homologies with mKIF4 were 82% and 85% for nucleotides and amino acids, respectively. A single transcript of 5. 0 kb was highly expressed in hematopoietic tissues including fetal liver, spleen, and thymus, and adult thymus and bone marrow. Comparison of the ORF with that of mKIF4 revealed some dissimilarities in the putative cargo binding domain which might affect binding specificities.

Expression of translationally controlled tumor protein mRNA in human colon cancer

The translationally controlled tumor protein (TCTP) was first identified as a tumor-associated protein. Here we described the expression profile of TCTP mRNA using a panel of normal human tissues. We also investigated the cell-cycle-dependent expression of the TCTP mRNA using synchronized cultures of Saccahromyces cerevisiae. The TCTP gene was constantly expressed through the yeast cell cycle. The expression of TCTP mRNA from three human colon carcinoma cell lines and their tumors xenografted in a nude mouse was studied. Our data imply that the TCTP is a housekeeping gene and that its deregulation may be involved in the tumor development of colon carcinoma.

Ultrastructural changes in microvessel with age in the hippocampus of senescence-accelerated mouse (SAM)-P/10

Microvessels in the hippocampus of aged SAM-P/10 (14 months old) showed the following ultrastructural changes compared with those of young-mature controls (3 months old): (1) the majority of capillaries had lost the smooth contours typical of young cases; (2) the luminal surface of capillaries showed irregularity; (3) the endothelial cytoplasm was thicker; (4) vesicles appeared more frequently in the endothelium; (5) interendothelial tight junctions and basement membranes, however, seemed to show no significant abnormalities; (6) pericytes, especially those of arterioles and venules, contained many enlarged cytoplasmic inclusions with honeycomb-like vacuoles; (7) the area of glial perivascular end feet was greater. These morphological findings raise the possibility of impaired blood-brain barrier function and microhemodynamic disturbances in aged SAM-P/10 hippocampus.

Gastric malignant stromal tumor with long stalk impacted into duodenum

Most GIST have traditionally been classified as submucosal origin by upper gastrointestinal series (UGIS) or endoscopy. However, we experienced a gastrointestinal mesenchymal origin tumor expressed by polypoid mass with a long stalk. The gastric outlet was obstructed by the polypoid mass on the duodenum. The microscopic findings of the resected mass showed a stromal cell component by immunohistochemical stain. We experienced gastric stromal tumor found as a polypoid mass with long stalk which was easily detected by endoscopy. It would not have been suspected as a stromal tumor as a result of endoscopic findings only.

Power-frequency electric and magnetic fields and risk of childhood leukemia in Canada

In a case-control study of childhood leukemia in relation to exposure to power-frequency electric and magnetic fields (EMF), 399 children resident in five Canadian provinces who were diagnosed at ages 0-14 years between 1990 and 1994 (June 1995 in British Columbia and Quebec) were enrolled, along with 399 controls. Exposure assessment included 48-hour personal EMF measurement, wire coding and magnetic field measurements for subjects' residences from conception to diagnosis/reference date, and a 24-hour magnetic field bedroom measurement. Personal magnetic fields were not related to risk of leukemia (adjusted odds ratio (OR) = 0.95, p for trend = 0.73) or acute lymphatic leukemia (OR = 0.93, p for trend = 0.64). There were no clear associations with predicted magnetic field exposure 2 years before the diagnosis/reference date or over the subject's lifetime or with personal electric field exposure. A statistically nonsignificant elevated risk of acute lymphatic leukemia was observed with very high wiring configurations among residences of subjects 2 years before the diagnosis/reference date (OR = 1.72 compared with underground wiring, 95% confidence interval 0.54-5.45). These results provide little support for a relation between power-frequency EMF exposure and risk of childhood leukemia.

Prenatal vitamin supplementation and risk of childhood brain tumors

An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976 to 1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1,051 cases and for 1,919 controls from 8 geographic areas in North America, Europe and Israel. While risk estimates varied by study center, combined results suggest that maternal supplementation for 2 trimesters decreased risk of brain tumor [odds ratio (OR) = 0.7; 95% confidence interval (CI) = 0.5, 0.9], with a trend of less risk with longer duration of use (p trend = 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all 3 trimesters (OR = 0.5; CI = 0.3, 0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breastfeeding. Our findings are largely driven by data from the United States, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied markedly from 3% in Israel and in France, 21% in Italy, 33% in Canada and 52% in Spain to 86-92% at the 3 U.S. centers. The composition of the various multivitamin compounds taken also varied: daily dose of vitamin C ranged from 0 to 600 mg; vitamin E from 0 to 70 mg; vitamin A from 0 to 30,000 IU; and folate from 0 to 2,000 micrograms. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine the potential independent effects of these micronutrients.

Prenatal vitamin supplementation and pediatric brain tumors: huge international variation in use and possible reduction in risk

An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976-1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1051 cases and for 1919 controls in eight geographic areas of North America, Europe and Israel. While risk estimates varied by study center, combined results suggest that maternal supplementation for two trimesters may decrease risk of brain tumor [odds ratio (OR)=0.7; 95% confidence interval (CI)=0.5-0.9], with a trend toward less risk with longer duration of use (P trend= 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all three trimesters (OR=0.5; CI=0.3- 0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breast feeding. These findings are largely driven by data from the US, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied tremendously, from 3% in Israel and in France through 21% in Italy, 33% in Canada, 52% in Spain to 86-92% at the three US centers. The composition of the various multivitamin compounds taken also varied: daily dose of vitamin C ranged from 0 up to 600 mg; vitamin E from 0 to 70 mg; vitamin A from 0 to 30,000 IU and folate from 0 to 2000 mg. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine potential independent effects of these micronutrients.

Binding of murine leukemia virus Gag polyproteins to KIF4, a microtubule-based motor protein

A cDNA clone encoding a cellular protein that interacts with murine leukemia virus (MuLV) Gag proteins was isolated from a T-cell lymphoma library. The sequence of the clone is identical to the C terminus of a cellular protein, KIF4, a microtubule-associated motor protein that belongs to the kinesin superfamily. KIF4-MuLV Gag associations have been detected in vitro and in vivo in mammalian cells. We suggest that KIF4 could be involved in Gag polyprotein translocation from the cytoplasm to the cell membrane.

Results from an international case-control study of childhood brain tumors: the role of prenatal vitamin supplementation

An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976 to 1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1051 cases and 1919 controls from eight geographic areas in North America, Europe, and Israel. Although risk estimates varied by study center, combined results suggest that maternal supplementation for two trimesters may decrease risk of brain tumor (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.5-0.9), with a trend of less risk with longer duration of use (p trend = 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all three trimesters (OR 0.5, CI 0.3-0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breast feeding. These findings are largely driven by data from the United States, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied tremendously: from 3% in Israel and France, 21% in Italy, 33% in Canada, 52% in Spain and 86 to 92% at the three U.S. centers. The composition of the various multivitamin compounds taken also varied: the daily dose of vitamin C ranged from 0 to 600 mg, vitamin E ranged from 0 to 70 mg, vitamin A ranged from 0 to 30,000 IU, and folate ranged from 0 to 2000 micrograms. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine potential independent effects of these micronutrients.

Implementation of natural attenuation at a JP-4 jet fuel release after active remediation

After eighteen months of active remediation at a JP-4 jet-fuel spill, a residual of unremediated hydrocarbon remained. Further site characterization was conducted to evaluate the contribution of natural attenuation to control exposure to hazards associated with the residual contamination in the subsurface. Activities included the detailed characterization of ground-water flow through the spill; the distribution of fuel contaminants in groundwater; and the analysis of soluble electron acceptors moving into the spill from upgradient. These activities allowed a rigorous evaluation of the transport of contaminants from the spill to the receptor of groundwater, the Pasquotank River. The transport of dissolved contaminants of concern, that is benzene, toluene, ethyl benzene, xylene isomers (BTEX) and methyl-tertiary-butyl ether (MTBE), into the river from the source area was controlled by equilibrium dissolution from the fuel spill to the adjacent groundwater, diffusion in groundwater from the spill to permeable layers in the aquifer, and advective transport in the permeable layers. The estimated yearly loading of BTEX compounds and MTBE into the receptor was trivial even without considering biological degradation. The biodegradation of hydrocarbon dissolved in groundwater through aerobic respiration, denitrification, sulfate reduction, and iron reduction was estimated from changes in ground-water chemistry along the flow path. The concentrations of target components in permanent monitoring wells continue to decline over time. Long term monitoring will ensure that the plume is under control, and no further active remediation is required.

The adenylate cyclase gene MAC1 of Magnaporthe grisea controls appressorium formation and other aspects of growth and development

Magnaporthe grisea, the causal agent of rice blast disease, differentiates a specialized infection structure called an appressorium that is crucial for host plant penetration. Previously, it was found that cAMP regulates appressorium formation. To further understand the cellular mechanisms involved in appressorium formation, we have cloned a gene (MAC1) encoding adenylate cyclase, a membrane-bound enzyme that catalyzes the production of cAMP from ATP, by using a polymerase chain reaction-based strategy. The entire gene was isolated and subcloned from a large insert bacterial artificial chromosome library. Sequence characterization showed that MAC1 has a high degree of identity with other adenylate cyclase genes from several filamentous fungi as well as yeasts. Gene deletion resulted in reduced vegetative growth, conidiation, and conidial germination. Transformants lacking MAC1 were unable to form appressoria on an inductive surface and were unable to penetrate susceptible rice leaves. mac1- transformants were also sterile and produced no perithecia. Appressorium formation was restored in the presence of exogenous cAMP derivatives. These results confirm that cell signaling involving cAMP plays a central role in the development and pathogenicity of M. grisea.

Expression of Alzheimer's amyloid precursor protein in human lymphocyte

Beta-amyloid precursor protein (betaAPP) has been shown to be involved in cell growth regulation. In spleen, the majority of cells showing betaAPP like immunoreactivity was found in the T cell-dependent zone. In Northern blot, the expression of betaAPP was increased to reach the peak at 72 h after the treatment of phytohemagglutinin (PHA). But, in cytofluorometry, almost all CD4(+) T helper/inducer cells and the majority of CD(8+) T suppressor/cytotoxic cells show betaAPP immunoreactivity which remained constant during the stimulation with PHA. These results suggest that betaAPP is a surface molecule of T lymphocyte and the turnover or release of APP might be increased with the treatment of T cell mitogen.

Novel anticholinesterase and antiamnesic activities of dehydroevodiamine, a constituent of Evodia rutaecarpa

To find a new compound with antiamnesic activity, we screened 29 natural products for their abilities to inhibit acetylcholinesterase and reverse scopolamine-induced amnesia. Among the plants tested Evodia rutaecarpa Bentham showed a strong inhibitory effect on acetylcholinesterase in vitro and an anti-amnesic effect in vivo. By sequential fractionation of E. rutaecarpa, the active component was finally identified as dehydroevodiamine hydrochloride (DHED). DHED inhibited acetylcholinesterase activity in a dose-dependent and non-competitive manner. The IC50 value of DHED is 37.8 microM. A single administration of DHED to rats (6.25 mg/kg) significantly reversed the scopolamine-induced memory impairment in a passive avoidance test. The antiamnesic effect of DHED was more potent than that of tacrine which is the only drug for Alzheimer's disease approved by FDA. This potent antiamnesic effect of DHED was thought to be due to the combined effects of acetylcholinesterase inhibition and the known cerebral blood flow enhancement. These results indicate that DHED has novel anti-cholinesterase and antiamnesic activities and might have therapeutic potential in various disorders including Alzheimer's disease.

Evaluation of therapeutic regimens for the treatment of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is currently considered the most important exogenous factor in the genesis of gastritis and peptic ulcer disease. However, the optimum regimen for the eradication of H. pylori remains unclear. The purpose of this study was to evaluate the eradication rate of H. pylori, the side effects, and the patients' compliance with regard to various drug regimens. We also analyzed factors influencing the eradication of H. pylori. One hundred and eighty patients were included and divided into four groups: 42 patients (Group I) received tripotassium dicitrato bismuthate (240 mg b.i.d.), metronidazole (250 mg t.i.d.) and amoxicillin (500 mg t.i.d.) for 14 days; 55 patients (Group 2) received omeprazole (20 mg b.i.d.) and amoxicillin (1000 mg b.i.d.) for 14 days; 36 patients (Group 3) were treated with omeprazole (20 mg b.i.d.), metronidazole (250 mg t.i.d.) and amoxicillin (500 mg t.i.d.) for 14 days; and 47 patients (Group 4) received omeprazole (20 mg q.d.) and amoxicillin (500 mg t.i.d.) for 14 days and then tripotassium dicitrato bismuthate (240 mg b.i.d.) and nizatidine (150 mg q.d.) for 14 days. The diagnosis of H. pylori was made by histology. The eradication of H. pylori was defined both by histology (H&E and Giemsa stain) and by rapid urease test (CLOR) showing negative for H. pylori 4 weeks after the completion of therapy. Of the 180 patients, 95 patients had non-ulcer dyspepsia, 40 patients had gastric ulcer and 45 patients had duodenal ulcer. The eradication rate of H. pylori was highest (89.3%) in Group 3, as compared with Group 1 (68.9%), Group 2 (65.4%), and Group 4 (48.9%). The eradication rate was significantly higher in Group 3 than in Groups 2 and 4 (p < 0.05). There was no significant difference in the eradication rate among clinical diagnosis, sex and age. But, in the conventional triple therapy (Group 1), the eradication rate was higher in male (78.6%) than in female (46.2%). The side effects in order, were nausea (22.1%), dizziness (19.5%), abdominal pain (11.6%) and diarrhea (97%), and there was no difference among the drug regimens. The compliance of the patients was good (more than 80% irrespective of drug regimen). On the basis of these findings, the side effects of the drugs seemed minimal, and the compliance of patients was good irrespective of the drug regimen. In conclusion, the triple therapy with omeprazole, metronidazole and amoxicillin was the most effective regimen and could be recommended for H. pylori eradication.

Molecular physiology, biochemistry, and pharmacology of Alzheimer's amyloid precursor protein (APP)

The function of APP is not yet known in detail but growing evidence exists that APP may mediate cell interactions with the cell surface or soluble glycoproteins and defense mechanisms in the CNS involving the immune system. We describe here the finding that almost all CD4+ lymphocytes and the majority of CD8+ lymphocytes were positive for A beta and the antibodies against A beta or APP did not inhibit the [3H]-thymidine uptake of mitogen-treated lymphocytes significantly. There were no differences in the A beta immunoreactivity on the cell surface of lymphocytes between Alzheimer's disease (AD) and control samples. Excessive amyloidogenic pathway of APP processing may be the final common pathway involved in the pathogenesis of AD. Thus, the identification of proteases or factors leading to aberrant proteolysis which process APP to yield a variety of potentially amyloidogenic fragments would promise pharmacological targets to develop anti-AD drugs. In attempts to define the proteases or factors which alter the balance between nonamyloidogenic and amyloidogenic processing pathways, our study indicates that thrombin or acetylcholinesterase(AChE)-associated protease may be involved in the amyloidogenic processing pathway of APP in vivo to generate amyloidogenic intermediates linked to amyloid deposition. Highly specific and dose-dependent direct modulation of APP processing by biologically available metal ions including Ca2+, Zn2+, Fe2+/Fe3+ and Al3+ suggest the disrupted metal homeostasis as factors leading to overaccumulation of APP and subsequent aberrant proteolysis utilizing excessive amyloidogenic processing pathway. There is mounting evidence that at least some of the neurotoxicity associated with AD is due to fragments from APP. Most research has focused on the toxic effect and the ion channel activity of A beta in causation of the disease. The possible role of other cleaved products of APP is less clear. We investigated the channel-forming ability of various products of APP when applied to Xenopus oocytes and their neurotoxicity in vitro. CT105 peptide was found to be exceedingly potent at 500 nM concentration in forming nonselective ion channels during application from either outside or inside the oocyte and more toxic than either of the A beta fragments, A beta 25-35, or A beta 1-40. Taken together, these results suggest the possible involvement of CT peptide in inducing the neurotoxicity characteristic of AD through the direct damage on the cell membrane. Therefore, we hypothesize that amyloidogenic CT may make nonselective ion channels or pores in the membrane and may cause neuronal death in the early stage of AD and then further metabolized to more stable and less toxic A beta which may be finally deposited in the brain where it could inflict further toxicity to neurons. Here we report successful inhibition of APP gene expression by antisense oligodeoxynucleotides at the mRNA or the protein level in in vitro and cell culture systems.

Age-related changes of mRNA expression of amyloid precursor protein in the brain of senescence-accelerated mouse

APP695 mRNA is only expressed in the brains of SAM. The expression of APP mRNA in SAM P1 mice brains is more marked than that in SAM R1 mice brain. APP mRNA expression was increased with advancing age in all brain regions of SAM P1 mice compared with SAM R1. Especially, the changes of the amount of APP mRNA in the prosencephalon and the mesencephalon are significant at P value of 0.05. We suggest that overexpression of APP mRNA may be related to accelerated aging phenomenon in the SAM brain. This is the first report of age-related increase in the amount of APP mRNA in the SAM brain.

Complete nucleotide sequence and tissue-specific expression of the rat phenylethanolamine N-methyltransferase gene

The rat phenylethanolamine N-methyltransferase (PNMT) gene was isolated from a genomic library by cross-hybridization with a bovine PNMT cDNA probe. Complete nucleotide sequence analysis of a genomic clone showed that this gene contained three exons and spanned about 2.8 kb in length. There were the acute-phase response element, TATA, SP1, and GRE sequences. The physicochemical properties of rat adrenal PNMT were different from those of the brainstem PNMT. However, northern blot and reverse transcription-polymerase chain reaction analysis showed that the rat PNMT gene may not express the multiple forms of mRNA. These results suggest that the rat PNMT gene might produce a single enzyme protein, whose activity may be differentially modulated by tissue-specific environment in the central and peripheral systems.

Changing trends in histologic types of lung cancer during the last decade (1981-1990) in Korea: a hospital-based study

A review of the histopathology and past history of 2229 patients with primary lung cancer diagnosed at the Yonsei University Medical Center from 1981 to 1990 was performed to investigate the changes in histologic types and the relationship to smoking history. The most frequent histologic type of lung cancer was squamous cell carcinoma (956 patients, 54.0%) followed by adenocarcinoma (311 patients, 17.6%) in males (1772 patients), and adenocarcinoma (206 patients, 45.1%) followed by squamous cell carcinoma (126 patients, 27.6%) in females (457 patients). In both sexes, the predominant type was adenocarcinoma under the age of 40, whereas squamous cell carcinoma was the most frequent type above the age of 40. While squamous cell carcinoma decreased over 10 years (54.3% in 1981, 44.3% in 1990), adenocarcinoma showed a gradually increased incidence (17.0% in 1981, 28.3% in 1990) in both sexes, and the proportion of small cell carcinoma and large cell carcinoma remained unchanged. These changes in histologic type were more prominent in non-smokers. In conclusion, the increasing incidence of adenocarcinoma in both sexes, especially in non-smokers, suggests the possible presence of etiologic factors other than smoking, such as environmental pollution.

Oxidative stress induced by intermittent exposure at a simulated altitude of 4000 m decreases mitochondrial superoxide dismutase content in soleus muscle of rats

The effects were examined of 6-month intermittent hypobaric (4000 m) exposure on the antioxidant enzyme systems in soleus and tibialis muscles of rats. At the end of the 6-month experimental exposure, the six rats in both the exposed group and the control group were sacrificed. Immunoreactive mitochondrial superoxide dismutase (Mn-SOD) contents were measured as well as the activities of antioxidant enzymes [Mn-SOD, cytosolic SOD (Cu,Zn-SOD), catalase (CAT), and glutathione peroxidase (GPX)]. Thiobarbituric acid-reactive substances (TBARS) were also determined as an indicator of lipid peroxidation. The high altitude exposure resulted in a marked increase in TBARS content in soleus muscle, suggesting increased levels of oxygen free radicals. Conversely, significant decreases in both Mn-SOD content and activity in soleus muscle were noted after exposure. Such trends were not noticed in tibialis muscle. On the other hand, no significant changes in Cu,Zn-SOD, CAT, or GPX were observed in either muscle. These results suggested that the increases in lipid peroxidation were most probably a result of decreased Mn-SOD function which was more depressed in oxidative than in glycolytic muscle.

Bacterial expression, purification of full length and carboxyl terminal fragment of Alzheimer amyloid precursor protein and their proteolytic processing by thrombin

Human amyloid protein precursor(APP770) and its carboxyl terminal portion (CT105) including beta/A4 domain were highly expressed using strong expression systems in E. coli. These recombinant APP peptides were purified with a combination of urea solubilization and ion-exchange chromatography and used for proteolytic processing by thrombin. Three thrombin cleavage sites were predicted by the decrease of APP770 and the appearance of M(r) 56, 27 and 18 kDa fragments containing beta/A4 domain on SDS-PAGE gel and on the immunoblot. A similar but limited proteolysis of platelet APPs exposed to thrombin resulted in the stimulated production of 60 and 27 KDa carboxyl terminal peptides containing the intact beta/A4. This thrombin mediated proteolysis was completely blocked by hirudin, the specific thrombin inhibitor. These results suggest that thrombin may play a role in altered processing of APP to generate potentially amyloidogenic intermediates in vivo leading to amyloid deposition.

Ligand binding characteristics of [3H] dihydroalprenolol in cerebral cortical membranes of young and old senescence-accelerated mouse

1. The values of both Kd and Bmax of [3H] dihydroalprenolol binding in the cerebral cortical membranes of old-aged (12 month old) SAM-P/1 were not significantly different compared with those of young (2 month old) SAM-P/1. 2. The values of Ki of metoprolol in the young and old aged SAM were 119 +/- 39.5 nM and 157 +/- 55 nM, respectively. 3. The values of beta 1/beta 2 ratio of the young and old aged SAM were 1.67 +/- 0.15 and 1.64 +/- 0.13, respectively. 4. These results suggest that there were no significant changes of binding characteristics of beta 1 and beta 2 adrenoceptors during aging in the cerebral cortex of SAM.

Lung cancer following Hodgkin's disease: a case-control study

It is recognized that survivors of Hodgkin's disease are at a substantially increased risk of lung cancer. A collaborative group of population-based cancer registries and major treatment centers carried out a case-control study, in which 98 cases of lung cancer were identified in patients who had survived at least 1 year following a diagnosis of Hodgkin's disease. A total of 259 matched controls were selected from patients with Hodgkin's disease who did not develop subsequent lung cancer, and for both cases and controls detailed information was abstracted from medical records concerning stage and treatment of Hodgkin's disease. Patients treated with chemotherapy alone had about twice the risk of developing lung cancer than those treated by radiotherapy alone or both modalities. There was no increase in risk with cumulative number of cycles of chemotherapy. Among patients treated with radiotherapy alone, there was an increase in risk related to estimated radiation dose to the lung. There was also a strong association between cigarette smoking and the risk of lung cancer. The finding of a higher risk following chemotherapy than following radiotherapy was unexpected, but could not be explained by any identified methodological flaws. A plausible inference from the study is that all forms of Hodgkin's disease therapy are carcinogenic to the lung and that, in particular, chemotherapy is associated with an increase in risk which is at least comparable to and perhaps higher than the risk produced by radiotherapy.

Public objections to environmental tobacco smoke

METHODS. A randomly selected sample of Californian adults was surveyed by telephone to assess their knowledge, attitudes, and behaviors with respect to tobacco use and its control. The questions asked of this sample were whether they had recently (in the past 12 months) asked someone not to smoke in certain situations and whether they would ever consider doing such a thing. RESULTS. Results of the survey indicated that 59.1% of nonsmokers and 44.4% of smokers had asserted themselves within the past 12 months, while another 28.2 and 29.1% of the nonsmokers and smokers, respectively, indicated that they would consider asking someone not to smoke. Only 12.7% of the nonsmokers and 26.4% of the smokers indicated that they would not consider doing such a thing. Those more likely to object publicly to tobacco smoke are generally younger, are more educated, and have anti-tobacco attitudes related to either a specific health belief or social influence.

Very large deflection with quadratic voltage dependence of ZnO on Si(3)N(4) bimorph

ZnO on Si(3)N(4) bimorphs have shown large deflections with quadratic dependence on applied voltages. Several effects are suggested that might explain these large deflections. No conclusion on the origin of these large deflections can yet be given.

The constituent equations of piezoelectric heterogeneous bimorphs

The electromechanical characteristics of a heterogeneous piezoelectric bender subjected to various electrical and mechanical boundary conditions are discussed based on the results of the free bender analysis. The mechanical boundary conditions considered are: a mechanical moment at the end of the bender, a force applied perpendicularly to the tip of the bender, and a uniform load applied over the entire length of the bender. The constituent equations of the bender under these electromechanical influences are derived by calculating the internal energy assuming thermodynamic equilibrium.