Hepatitis E virus (HEV): molecular cloning and sequencing of the full-length viral genome

We have recently described the cloning of a portion of the hepatitis E virus (HEV) and confirmed its etiologic association with enterically transmitted (waterborne, epidemic) non-A, non-B hepatitis. The virus consists of a single-stranded, positive-sense RNA genome of approximately 7.5 kb, with a polyadenylated 3' end. We now report on the cloning and nucleotide sequencing of an overlapping, contiguous set of cDNA clones representing the entire genome of the HEV Burma strain [HEV(B)]. The largest open reading frame extends approximately 5 kb from the 5' end and contains the RNA-directed RNA polymerase and nucleoside triphosphate binding motifs. The second major open reading frame (ORF2) begins 37 bp downstream of the first and extends approximately 2 kb to the termination codon present 65 bp from the 3' terminal stretch of poly(A) residues. ORF2 contains a consensus signal peptide sequence at its amino terminus and a capsid-like region with a high content of basic amino acids similar to that seen with other virus capsid proteins. A third open reading frame partially overlaps the first and second and encompasses only 369 bp. In addition to the 7.5-kb full-length genomic transcript, two subgenomic polyadenylated messages of approximately 3.7 and 2.0 kb were detected in infected liver using a probe from the 3' third of the genome. The genomic organization of the virus is consistent with the 5' end encoding nonstructural and the 3' end encoding the viral structural gene(s). The expression strategy of the virus involves the use of three different open reading frames and at least three different transcripts. HEV was previously determined to be a nonenveloped particle with a diameter of 27-34 nm. These findings on the genetic organization and expression strategy of HEV suggest that it is the prototype human pathogen for a new class of RNA virus or perhaps a separate genus within the Caliciviridae family.

Diabetes as a risk factor for dementia and mild cognitive impairment: a meta-analysis of longitudinal studies

This study examined the association of diabetes with the onset of dementia (including Alzheimer's disease (AD), vascular dementia (VD) and any dementia) and mild cognitive impairment (MCI) by using a quantitative meta-analysis of longitudinal studies. EMBASE and MEDLINE were searched for articles published up to December 2010. All studies that examined the relationship between diabetes and the onset of dementia or MCI were included. Pooled relative risks were calculated using fixed and random effects models. Nineteen studies met our inclusion criteria for this meta-analysis, and 6184 subjects with diabetes and 38 530 subjects without diabetes were included respectively. All subjects were without dementia or MCI at baseline. The quantitative meta-analysis showed that subjects with diabetes had higher risk for AD (relative risk (RR):1.46, 95% confidence interval (CI): 1.20-1.77), VD (RR: 2.48, 95% CI: 2.08-2.96), any dementia (RR: 1.51, 95% CI: 1.31-1.74) and MCI (RR: 1.21, 95% CI: 1.02-1.45) than those without. The quantitative meta-analysis showed that diabetes was a risk factor for incident dementia (including AD, VD and any dementia) and MCI.

Generation of destabilized green fluorescent protein as a transcription reporter

The green fluorescent protein (GFP) is a widely used reporter in gene expression and protein localization studies. GFP is a stable protein; this property allows its accumulation and easy detection in cells. However, this stability also limits its application in studies that require rapid reporter turnover. We created a destabilized GFP for use in such studies by fusing amino acids 422-461 of the degradation domain of mouse ornithine decarboxylase (MODC) to the C-terminal end of an enhanced variant of GFP (EGFP). The fusion protein, unlike EGFP, was unstable in the presence of cycloheximide and had a fluorescence half-life of 2 h. Western blot analysis indicated that the fluorescence decay of EGFP-MODC-(422-461) was correlated with degradation of the fusion protein. We mutated key amino acids in the PEST sequence of EGFP-MODC-(422-461) and identified several mutants with variable half-lives. The suitability of destabilized EGFP as a transcription reporter was tested by linking it to NFkappaB binding sequences and monitoring tumor necrosis factor alpha-mediated NFkappaB activation. We obtained time course induction and dose response kinetics similar to secreted alkaline phosphatase obtained in transfected cells. This result did not occur when unmodified EGFP was used as the reporter. Because of its autofluorescence, destabilized EGFP can be used to directly correlate gene induction with biochemical change, such as NFkappaB translocation to the nucleus.

Function and mechanism of zinc metalloenzymes

Zinc is required for the activity of > 300 enzymes, covering all six classes of enzymes. Zinc binding sites in proteins are often distorted tetrahedral or trigonal bipyramidal geometry, made up of the sulfur of cysteine, the nitrogen of histidine or the oxygen of aspartate and glutamate, or a combination. Zinc in proteins can either participate directly in chemical catalysis or be important for maintaining protein structure and stability. In all catalytic sites, the zinc ion functions as a Lewis acid. Researchers in our laboratory are dissecting the determinants of molecular recognition and catalysis in the zinc-binding site of carbonic anhydrase. These studies demonstrate that the chemical nature of the direct ligands and the structure of the surrounding hydrogen bond network are crucial for both the activity of carbonic anhydrase and the metal ion affinity of the zinc-binding site. An understanding of naturally occurring zinc-binding sites will aid in creating de novo zinc-binding proteins and in designing new metal sites in existing proteins for novel purposes such as to serve as metal ion biosensors.

First-line erlotinib versus gemcitabine/cisplatin in patients with advanced EGFR mutation-positive non-small-cell lung cancer: analyses from the phase III, randomized, open-label, ENSURE study

BACKGROUND

The phase III, randomized, open-label ENSURE study (NCT01342965) evaluated first-line erlotinib versus gemcitabine/cisplatin (GP) in patients from China, Malaysia and the Philippines with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients ≥18 years old with histologically/cytologically confirmed stage IIIB/IV EGFR mutation-positive NSCLC and Eastern Cooperative Oncology Group performance status 0-2 were randomized 1:1 to receive erlotinib (oral; 150 mg once daily until progression/unacceptable toxicity) or GP [G 1250 mg/m(2) i.v. days 1 and 8 (3-weekly cycle); P 75 mg/m(2) i.v. day 1, (3-weekly cycle) for up to four cycles]. Primary end point: investigator-assessed progression-free survival (PFS). Other end points include objective response rate (ORR), overall survival (OS), and safety.

RESULTS

A total of 217 patients were randomized: 110 to erlotinib and 107 to GP. Investigator-assessed median PFS was 11.0 months versus 5.5 months, erlotinib versus GP, respectively [hazard ratio (HR), 0.34, 95% confidence interval (CI) 0.22-0.51; log-rank P < 0.0001]. Independent Review Committee-assessed median PFS was consistent (HR, 0.42). Median OS was 26.3 versus 25.5 months, erlotinib versus GP, respectively (HR, 0.91, 95% CI 0.63-1.31; log-rank P = .607). ORR was 62.7% for erlotinib and 33.6% for GP. Treatment-related serious adverse events (AEs) occurred in 2.7% versus 10.6% of erlotinib and GP patients, respectively. The most common grade ≥3 AEs were rash (6.4%) with erlotinib, and neutropenia (25.0%), leukopenia (14.4%), and anemia (12.5%) with GP.

CONCLUSION

These analyses demonstrate that first-line erlotinib provides a statistically significant improvement in PFS versus GP in Asian patients with EGFR mutation-positive NSCLC (NCT01342965).

Neurologic complications in children with enterovirus 71 infection

BACKGROUND

Enterovirus 71 infection causes hand-foot-and-mouth disease in young children, which is characterized by several days of fever and vomiting, ulcerative lesions in the oral mucosa, and vesicles on the backs of the hands and feet. The initial illness resolves but is sometimes followed by aseptic meningitis, encephalomyelitis, or even acute flaccid paralysis similar to paralytic poliomyelitis.

METHODS

We describe the neurologic complications associated with the enterovirus 71 epidemic that occurred in Taiwan in 1998. At three major hospitals we identified 41 children with culture-confirmed enterovirus 71 infection and acute neurologic manifestations. Magnetic resonance imaging (MRI) was performed in 4 patients with acute flaccid paralysis and 24 with rhombencephalitis.

RESULTS

The mean age of the patients was 2.5 years (range, 3 months to 8.2 years). Twenty-eight patients had hand-foot-and-mouth disease (68 percent), and 6 had herpangina (15 percent). The other seven patients had no skin or mucosal lesions. Three neurologic syndromes were identified: aseptic meningitis (in 3 patients); brain-stem encephalitis, or rhombencephalitis (in 37); and acute flaccid paralysis (in 4), which followed rhombencephalitis in 3 patients. In 20 patients with rhombencephalitis, the syndrome was characterized by myoclonic jerks and tremor, ataxia, or both (grade I disease). Ten patients had myoclonus and cranial-nerve involvement (grade II disease). In seven patients the brain-stem infection produced transient myoclonus followed by the rapid onset of respiratory distress, cyanosis, poor peripheral perfusion, shock, coma, loss of the doll's eye reflex, and apnea (grade III disease); five of these patients died within 12 hours after admission. In 17 of the 24 patients with rhombencephalitis who underwent MRI, T2-weighted scans showed high-intensity lesions in the brain stem, most commonly in the pontine tegmentum. At follow-up, two of the patients with acute flaccid paralysis had residual limb weakness, and five of the patients with rhombencephalitis had persistent neurologic deficits, including myoclonus (in one child), cranial-nerve deficits (in two), and ventilator-dependent apnea (in two).

CONCLUSIONS

In the 1998 enterovirus 71 epidemic in Taiwan, the chief neurologic complication was rhombencephalitis, which had a fatality rate of 14 percent. The most common initial symptoms were myoclonic jerks, and MRI usually showed evidence of brainstem involvement.

Far-field acoustic response: origins in the cat

Short-latency evoked potentials recorded from the vertex of adult cats in response to click stimulation (the far-field acoustic response) were analyzed in a series of lesion experiments to determine the origins of each component. The resultant data indicate that the primary generator of potential is the acoustic nerve; of potential 2, the cochlear nucleus; of potential 3, neurons of the superior olivary complex activated by projections crossing the midline; of potential 4, neurons of the ventral nucleus of the lateral lemniscus and preolivary region activated equally by crossed and uncrossed projections; and of potential 5, neurons of the inferior colliculus activated primarily by crossed projections.

Geometric packing constraints in egg phosphatidylcholine vesicles

This investigation presents a quantitative analysis of the asymmetric transmembrane lipid packing geometry in egg phosphatidylcholine vesicles. The analysis uses hydrodynamic and nuclear magnetic resonance data obtained for homogeneous egg phosphatidylcholine vesicles and demonstrates that the average area per lipid head group and effective length of the lipid are greater on the outer monolayer than on the inner monolayer of the egg phosphatidylcholine vesicle. Results also indicate that the bilayer of the egg phosphatidylcholine vesicles has an asymmetrical interface through its center.

Design of an artificial skin. II. Control of chemical composition

Detailed methodology is described for the reproducible preparation of collagen--glycosaminoglycan (GAG) membranes with known chemical composition. These membranes have been used to cover satisfactorily large experimental full-thickness skin wounds in guinea pigs over the past few years. Such membranes have effectively protected these wounds from infection and fluid loss for over 25 days without rejection and without requiring change or other invasive manipulation. When appropriately designed for the purpose, the membranes have also strongly retarded wound contraction and have become replaced by newly synthesized, stable connective tissue. In our work, purified, fully native collagen from two mammalian sources is precipitated from acid dispersion by addition of chondroitin 6-sulfate. The relative amount of GAG in the coprecipitate varies with the amount of GAG added and with the pH. Since coprecipitated GAG is generally eluted from collagen fibers by physiological fluids, control of the chemical composition of membranes is arrived at by crosslinking the collagen--GAG ionic complex with glutaraldehyde, or, alternately, by use of high-temperature vacuum dehydration. Appropriate use of the crosslinking treatment allows separate study of changes in membrane composition due to elution of GAG by extracellular fluid in animal studies from changes in composition due to enzymatic degradation of the grafted or implanted membrane in these studies. Exhaustive in vitro elution studies extending up to 20 days showed that these crosslinking treatments insolubilize in an apparently permanent manner a fraction of the ionically complexed GAG, although it could not be directly confirmed that glutaraldehyde treatment covalently crosslinks GAG to collagen. By contrast, the available evidence suggests strongly that high-temperature vacuum dehydration leads to formation of chemical bonds between collagen and GAG. Procedures are described for control of insolubilized and "free" GAG in these membranes as well as for control of the molecular weight between crosslinks (Mc). The insolubilized GAG can be controlled in the range 0.5--10 wt. % while "free" GAG can be independently controlled up to at least 25 wt. %; Mc can be controlled in the range 2500--40,000. Studies by infrared spectroscopy have shown that treatment of collagen--GAG membranes by glutaraldehyde or under high-temperature vacuum does not alter the configuration of the collagen triple helix in the membranes. Neither do these treatments modify the native banding pattern of collagen as viewed by electron microscopy. Collagen--GAG membranes appear to be useful as chemically well-characterized, solid macromolecular probes of biomaterial--tissue interactions.

Heparin is essential for the storage of specific granule proteases in mast cells

All mammals produce heparin, a negatively charged glycosaminoglycan that is a major constituent of the secretory granules of mast cells which are found in the peritoneal cavity and most connective tissues. Although heparin is one of the most studied molecules in the body, its physiological function has yet to be determined. Here we describe transgenic mice, generated by disrupting the N-deacetylase/N-sulphotransferase-2 gene, that cannot express fully sulphated heparin. The mast cells in the skeletal muscle that normally contain heparin lacked metachromatic granules and failed to store appreciable amounts of mouse mast-cell protease (mMCP)-4, mMCP-5 and carboxypeptidase A (mMC-CPA), even though they contained substantial amounts of mMCP-7. We developed mast cells from the bone marrow of the transgenic mice. Although these cultured cells contained high levels of various protease transcripts and had substantial amounts of mMCP-6 protein in their granules, they also failed to express mMCP-5 and mMC-CPA. Our data show that heparin controls, through a post-translational mechanism, the levels of specific cassettes of positively charged proteases inside mast cells.

Obesity induces expression of uncoupling protein-2 in hepatocytes and promotes liver ATP depletion

Uncoupling protein 2 (UCP2) uncouples respiration from oxidative phosphorylation and may contribute to obesity through effects on energy metabolism. Because basal metabolic rate is decreased in obesity, UCP2 expression is predicted to be reduced. Paradoxically, hepatic expression of UCP2 mRNA is increased in genetically obese (ob/ob) mice. In situ hybridization and immunohistochemical analysis of ob/ob livers demonstrate that UCP2 mRNA and protein expression are increased in hepatocytes, which do not express UCP2 in lean mice. Mitochondria isolated from ob/ob livers exhibit an increased rate of H+ leak which partially dissipates the mitochondrial membrane potential when the rate of electron transport is suppressed. In addition, hepatic ATP stores are reduced and these livers are more vulnerable to necrosis after transient hepatic ischemia. Hence, hepatocytes adapt to obesity by up-regulating UCP2. However, because this decreases the efficiency of energy trapping, the cells become vulnerable to ATP depletion when energy needs increase acutely.

Discrimination of Alzheimer's disease and mild cognitive impairment by equivalent EEG sources: a cross-sectional and longitudinal study

OBJECTIVES

The spatial aspects of brain electrical activity can be assessed by equivalent EEG frequency band generators. We aimed to describe alterations of these EEG generators in Alzheimer's disease (AD) and healthy aging and whether they could serve as predictive markers of AD in subjects at risk.

METHODS

The amplitude and 3-dimensional localization of equivalent EEG sources were evaluated using FFT dipole approximation in 38 mild AD patients, 31 subjects with mild cognitive impairment (MCI) and 24 healthy control subjects.

RESULTS

AD patients showed an increase of delta and theta global field power (GFP), which corresponds to the generalized EEG amplitude, as well as a reduction of alpha GFP when compared to the controls. A decrease of alpha and beta GFP was found in AD patients, as compared to the MCI subjects. With respect to topography in the antero-posterior direction, sources of alpha and beta activity shifted more anteriorly in AD patients compared to both the controls and MCI subjects. No significant difference was found between MCI and controls. Combined alpha and theta GFP were the best discriminating variables between AD patients and controls (84% correct classification) and AD and MCI subjects (78% correctly classified). MCI subjects were followed longitudinally (25 months on average) in order to compare differences in baseline EEG variables between MCI subjects who progressed to AD (PMCI) and those who remained stable (SMCI). Compared to SMCI, PMCI had decreased alpha GFP and a more anterior localization of sources of theta, alpha and beta frequency. In a linear discriminant analysis applied on baseline values of the two MCI subgroups, the best predictor of future development of AD was found to be antero-posterior localization of alpha frequency.

CONCLUSIONS

FFT dipole approximation and frequency analysis performed by conventional FFT showed comparable classification accuracy between the studied groups. We conclude that localization and amplitude of equivalent EEG sources could be promising markers of early AD.

Manganism and idiopathic parkinsonism: similarities and differences

From the comparison we have made between PD and manganism, we draw the following conclusions: 1. There are similarities between PD and manganism, notably the presence of (a) generalized bradykinesia and (b) widespread rigidity. 2. There are also dissimilarities between PD and manganism, notably the following in manganism: (a) less-frequent resting tremor, (b) more frequent dystonia, (c) a particular propensity to fall backward, (d) failure to achieve a sustained therapeutic response to levodopa, and (e) failure to detect a reduction in fluorodopa uptake by PET. Further studies are likely to yield more discriminants between PD and manganism. For example, PET with raclopride may be useful in early cases of manganism, and MRI may be helpful in patients with advanced manganism.

Binding of the A1-selective adenosine antagonist 8-cyclopentyl-1,3-dipropylxanthine to rat brain membranes

8-Cyclopentyl-1,3-dipropylxanthine (PD 116,948) is a very potent, very A1-selective adenosine antagonist, with a Ki of 0.46 nM in 3H-CHA binding to A1 receptors in rat whole brain membranes and 340 nM in 3H-NECA binding to A2 receptors in rat striatal membranes. Its 740-fold A1-selectivity is the highest reported for an adenosine antagonist. 3H-PD 116,948 (117 Ci/mmol) was prepared by reduction of the diallyl analog. 3H-PD 116,948 bound to a single site in rat whole brain membranes, with a Bmax of 46 pmol/g wet weight and Kd of 0.42 nM. Nonspecific binding was extremely low, amounting to about 3% of total binding under standard conditions and less than 1% when higher tissue concentrations were used. Affinities of compounds for inhibition of 3H-PD 116,948 binding were highly consistent with an A1 adenosine receptor. Antagonists were equally potent in 3H-PD 116,948 binding and in 3H-CHA binding, while agonists were consistently about 12-fold more potent in 3H-CHA binding. Hill coefficients were 1.0 for antagonists and about 0.65 for agonists. 3H-PD 116,948 should be a useful antagonist ligand for adenosine A1 receptors.

Early dexamethasone therapy in preterm infants: a follow-up study

OBJECTIVES

To study the outcome at 2-year corrected age of infants who participated in a double-blind controlled trial of early (<12 hours) dexamethasone therapy for the prevention of chronic lung disease (CLD).

METHODS AND MATERIALS

A total of 133 children (70 in the control group, 63 in the dexamethasone-treated group) who survived the initial study period and lived to 2 years of age were studied. All infants had birth weights of 500 to 1999 g and had severe respiratory distress syndrome requiring mechanical ventilation within 6 hours after birth. For infants in the treatment group, dexamethasone was started at a mean age of 8.1 hours and given 0.25 mg/kg every 12 hours for 1 week and then tapered off gradually over a 3-week period. The following variables were evaluated: interim medical history, socioeconomic background, physical growth, neurologic examinations, mental and psychomotor development index score (MDI and PDI), pulmonary function, electroencephalogram, and auditory and visual evoked potential.

RESULTS

Infants in the control group tended to have a higher incidence of upper respiratory infection and rehospitalization than did the dexamethasone-treated group because of respiratory problems. Although there was no difference between the groups in somatic growth in girls, the dexamethasone-treated boys had significantly lower body weight and shorter height than the control boys (10.7 +/- 3.0 vs 11.9 +/- 2.0 kg; 84.9 +/- 5.7 vs 87.5 +/- 4.8 cm). The dexamethasone-treated group had a significantly higher incidence of neuromotor dysfunction (25/63 vs 12/70) than did the control group. The dexamethasone-treated infants also had a lower PDI score (79 +/- 26) than did the control group (87 +/- 23), but the difference was not statistically significant. Both groups were comparable in MDI, incidence of vision impairment, and auditory and visual evoked potential. Significant handicap, defined as severe neurologic defect and/or intellectual defect (MDI and/or PDI </= 69), was seen in 22 children (31.4%) in the control group and 26 (41.2%) in the dexamethasone-treated group.

CONCLUSIONS

Although early postnatal dexamethasone therapy for 4 weeks significantly reduces the incidence of CLD, this therapeutic regimen cannot be recommended at present because of its adverse effects on neuromotor function and somatic growth in male infants, detected at 2 years of age. A longer follow-up is needed. If early dexamethasone therapy is to be used for the prevention of CLD, the therapeutic regimen should be modified. The proper route of administration, the critical time to initiate the therapy, and the dosage and duration of therapy remain to be defined further.

Molecular cloning and sequencing of the Mexico isolate of hepatitis E virus (HEV)

Hepatitis E virus (HEV) is the major causative agent of hepatitis E or what was formerly known as enterically transmitted non-A, non-B hepatitis. The disease has a worldwide distribution but occurs principally in developing countries in any of three forms: large epidemics, smaller outbreaks, or sporadic infections. Genetic variation of different HEV strains was previously noted and it will be important to determine the extent to which this variation may pose problems in the diagnosis and treatment of HEV infection. To analyze differences at the genetic level between HEV(Mexico; M) and the previously characterized HEV(Burma; B) and HEV(Pakistan; P) isolates, overlapping cDNAs were cloned from samples obtained from an infected human and an experimentally inoculated cynomolgus macaque. These cDNA clones, representing the nearly complete (7185-bp) genome of HEV(M), confirmed an expression strategy for the virus that involves the use of 3 forward open reading frames (ORFs). The HEV(M) strain has an overall 76 and 77% nucleic acid identity with the HEV(B) strain and HEV(P) strain, respectively; however, the degree of sequence variation was not uniform throughout the viral genome. A hypervariable region was identified in ORF1 that exhibited a 58 and 54% nucleic acid sequence and 13% amino acid similarity with the Burma strain and the Pakistan strain, respectively. A large number of the nucleotide differences occurred at the third codon position, with the deduced amino acid sequences similarity of 83, 93, and 87% between HEV(M) and HEV(B) isolates in ORF1, ORF2, and ORF3, respectively, and with 84, 93, and 87% amino acid identities between HEV(M) and HEV(P) isolates in ORF1, ORF2, and ORF3, respectively. The nucleotide sequences derived from the highly conserved regions of HEV genome will be useful in developing polymerase chain reaction-based tests to confirm the viral infection. Knowledge of the extent of the sequence variation encountered with HEV will not only aid in the future development of diagnostic and vaccine reagents but also further our understanding of how HEV strain variation might impact the pathological outcome of infection.

Body mass index during childhood, adolescence and young adulthood in relation to adult overweight and adiposity: the Fels Longitudinal Study

BACKGROUND

Childhood overweight develops during 'critical periods', but the relationship of body mass index (BMI) patterns during 'critical periods' from childhood into adulthood with subsequent overweight and adiposity has not been previously investigated. BMI patterns during early childhood, pubescence and post-pubescence and their independent effects on overweight and body fatness at 35-45 y of age were examined along with birth weight and the effects of adult lifestyle factors.

METHODS

BMI parameters describing the timing, velocity minimum (min) and maximum (max) values from 2 to 25 y of age were related to adulthood BMI values and total and percentage body fat (TBF, %BF) at 35-45 y. These data were from 180 males and 158 females in the Fels Longitudinal Study.

RESULTS

There was no sex difference in the timing of BMI rebound, but the age of BMI maximum velocity and maximum BMI were both earlier in girls. Children with an earlier BMI rebound had larger BMI values at rebound and at maximum velocity. Children who reached maximum BMI at later age had larger maximum BMI values. Maximum BMI was a strong predictor for adult BMI and in females, a strong predictor of adulthood TBF and %BF. Maximum BMI was closely related to maximum BMI velocity in females and in males, BMI at maximum velocity is a strong predictor of TBF and %BF.

CONCLUSIONS

Changes in childhood BMI were related to adult overweight and adiposity more so in females than males. BMI rebound is a significant important period related to overweight at 35-45 y in females but not in males. However BMI patterns during and post-adolescence were more important than the BMI rebound for adulthood TBF and %BF status. There is marked tracking in BMI from approximately 20 y into 35-45 y. The pattern of BMI changes from 2 to 25 y had stronger effects on subsequent adult overweight than birth weight and adult lifestyle variables.

Endotoxemia in patients with chronic liver diseases: relationship to severity of liver diseases, presence of esophageal varices, and hyperdynamic circulation

Plasma endotoxin levels were investigated using a quantitative Limulus assay in patients with chronic liver diseases and correlated with the severity of liver diseases, the presence of esophageal varices, and hemodynamic parameters. The plasma endotoxin levels were significantly higher in chronic hepatitis patients with acute exacerbation (10.1 +/- 1.3 pg/ml, n = 13, p < 0.05) and patients with cirrhosis (7.0 +/- 0.7 pg/ml, n = 126, p < 0.05) than in healthy subjects (2.9 +/- 0.2 pg/ml, n = 45). Chronic hepatitis patients (n = 30) had plasma endotoxin levels which were similar to those in healthy subjects (4.6 +/- 0.5 vs. 2.9 +/- 0.2 pg/ml, p > 0.05) but lower than those in chronic hepatitis patients with acute exacerbation (4.6 +/- 0.5 vs. 10.1 +/- 1.3 pg/ml, p < 0.05). Endotoxemia (plasma endotoxin level > 5.7 pg/ml) was found in 27%, 85% and 41% of patients with chronic hepatitis, chronic hepatitis with acute exacerbation, and cirrhosis, respectively. In patients with cirrhosis, the plasma endotoxin levels progressively increased in relation to the severity of liver dysfunction (Pugh's class A/B/C = 4.9 +/- 0.5/7.9 +/- 1.4/10.2 +/- 2.0 pg/ml, p < 0.05). In contrast, plasma endotoxin levels were comparable between patients with cirrhosis with and without esophageal varices (p > 0.05). Chronic hepatitis patients with acute exacerbation (no collaterization) had much higher plasma endotoxin levels than those in patients with cirrhosis and large varices (p < 0.05), whereas compensated patients with cirrhosis and large esophageal varices had plasma endotoxin levels similar to those seen in chronic hepatitis patients (no collaterization) (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Resveratrol suppresses cell transformation and induces apoptosis through a p53-dependent pathway

Resveratrol, a plant constituent enriched in the skin of grapes, is one of the most promising agents for the prevention of cancer. However, the mechanism of the anti-carcinogenic activity of resveratrol is not well understood. Here we offer a possible explanation of its anti-cancer effect. Resveratrol suppresses tumor promoter-induced cell transformation and markedly induces apoptosis, transactivation of p53 activity and expression of p53 protein in the same cell line and at the same dosage. Also, resveratrol-induced apoptosis occurs only in cells expressing wild-type p53 (p53+/+), but not in p53-deficient (p53-/-) cells, while there is no difference in apoptosis induction between normal lymphoblasts and sphingomyelinase-deficient cell lines. These results demonstrate for the first time that resveratrol induces apoptosis through activation of p53 activity, suggesting that its anti-tumor activity may occur through the induction of apoptosis.

Clinical spectrum of enterovirus 71 infection in children in southern Taiwan, with an emphasis on neurological complications

An outbreak of enterovirus 71 (EV71) infection occurred in Taiwan in 1998. The clinical spectrums and laboratory findings for 97 patients with virus culture-proven EV71 infections were analyzed. Eighty-seven percent of the patients were younger than age 5 years. Hand-foot-and-mouth syndrome occurred in 79% of the children and central nervous system (CNS) involvement in 35%, including nine fatal cases. The predominant neurological presentations were myoclonus (68%), vomiting (53%), and ataxia (35%). Brain stem encephalitis was the cardinal feature of EV71 CNS involvement during this outbreak. Magnetic resonance imaging and pathological findings illustrated that the midbrain, pons, and medulla were the target areas. EV71 brain stem encephalitis can present either with cerebellar signs and an initially mild, reversible course or with overwhelming neurogenic shock and neurogenic pulmonary edema (NPE) resulting in a fatal outcome. Brain stem encephalitis that progressed abruptly to neurogenic shock and NPE was indicative of poor prognosis in this epidemic. Early aggressive treatment and close monitoring of the neurological signs are mandatory to improve the chance of survival.

Risk factors for primary lung cancer among non-smoking women in Taiwan

BACKGROUND

Although cigarette smoking is considered to be the most important cause of lung cancer, smoking behaviour cannot fully explain the epidemiological characteristics of lung cancer in Taiwanese women, who rarely smoke but contract lung cancer relatively often. There are other causes of lung cancer that have produced variability in lung cancer incidence.

METHODS

A case-control study involving interviews with 117 female patients (including 106 non-smoking) suffering from lung cancer and the same number of individually matched hospital controls was conducted in Kaohsiung, Taiwan between 1992 and 1993. The questionnaire administered to cases and controls collected information on cigarette smoking and suspected risk factors for lung cancer. Multivariate logistic regression analysis was applied to assess smoking for all women and suspected risk factors for non-smoking women.

RESULTS

The relationship between cigarette smoking and lung cancer was statistically significant although only a small proportion (9.4%) of female patients had smoked. However, the risk of contracting cancer for non-smoking women appears to be associated with certain cooking practices, especially preparing meals in kitchens not equipped with a fume extractor at cooking age of 20-40 years (odds ratio [OR] = 8.3; 95% confidence interval [CI]: 3.1-22.7. These factors and a history of pulmonary tuberculosis plus low consumption of fresh vegetables explained 78% of the summary attributable risks for non-smoking women in a multivariate logistic regression model.

CONCLUSIONS

Exposure to fumes from cooking oils, when not reduced by an extractor, may be an important factor in causing lung cancer in non-smoking Taiwanese women.

p38 kinase mediates UV-induced phosphorylation of p53 protein at serine 389

The p53 tumor suppressor protein is a transcription factor that plays a key role in the process of apoptosis and the cell's defense against tumor development. Activation of p53 occurs, at least in part, by phosphorylation of its protein. Very recently it has been reported that UV induced a functional activation of p53 via phosphorylation at serine 389. Here, we report that the UV-induced phosphorylation of p53 at serine 389 is mediated by p38 kinase. UVC-induced phosphorylation of p53 at serine 389 was markedly impaired by either pretreatment of cells with p38 kinase inhibitor, SB202190, or stable expression of a dominant negative mutant of p38 kinase. In contrast, there was no inhibition observed in cells treated with specific MEK1 inhibitor, PD98059, or with stable expression of a dominant negative mutant of ERK2 or JNK1. Most importantly, p38 kinase could be co-immunoprecipitated with p53 by using antibodies against p53. Incubation of active p38 kinase with p53 protein caused the phosphorylation of p53 protein at serine 389 in vitro, while no phosphorylation of p53 at serine 389 was observed when p53 was incubated with activated JNK2 or ERK2. Furthermore, pretreatment of cells with SB202190 blocked the p53 DNA binding activity and p53-dependent transcription. These results strongly suggest that the p38 kinase is at least one of the most important mediators of p53 phosphorylation at serine 389 induced by UVC radiation.

Prognostic significance of angiogenesis in human pancreatic cancer

To evaluate whether angiogenic factors are of clinical relevance to actual human pancreatic cancers, we studied the intratumoral microvessel density (IMD), and PD-ECGF, VEGF protein expression in 40 pancreatic cancers using immunohistochemistry. We also investigated PD-ECGF and VEGF gene expression using reverse transcriptase-PCR (RT-PCR). Of the 40 pancreatic cancers studied, 30 carcinomas (75.0%) were evaluated to be PD-ECGF-positive and 10 carcinomas (25.0%) were determined to be PD-ECGF-negative. In contrast, 27 carcinomas (67.5%) were evaluated to be VEGF-positive, whereas 13 carcinomas (32.5%) were VEGF-negative. VEGF gene expression was moderately associated with an increase in the IMD (r2 = 0.181, P = 0.006), but no significant relationship was found between PD-ECGF gene expression and the IMD (r2 = 0.093, P = 0.059). However, tumours with positive expression for both PD-ECGF and VEGF had a higher IMD (P = 0.027). The results of the immunohistochemistry agreed well with the results of the quantitative RT-PCR. The median survival time of the hypervascular group was significantly shorter than that of the hypovascular group (P < 0.0001). In comparing the survival according to PD-ECGF and VEGF gene expression, the median survival time of the patients with positive PD-ECGF expression was significantly shorter than those with negative PD-ECGF expression (P = 0.040). Furthermore, the median survival time of the patients with positive VEGF expression was significantly shorter than those with negative VEGF expression (P = 0.048). However, the Cox multivariate analysis indicated that the IMD and VEGF expression were independent prognostic factors of the various clinicopathologic variables in pancreatic cancer patients (P = 0.0021 and P = 0.0443, respectively).

Toll-like receptor 4 mediates intracellular signaling without TNF-alpha release in response to Cryptococcus neoformans polysaccharide capsule

Toll-like receptors (TLR) 2 and 4 are cell surface receptors that in association with CD14 enable phagocytic inflammatory responses to a variety of microbial products. Activation via these receptors triggers signaling cascades, resulting in nuclear translocation of NF-kappa B and a proinflammatory response including TNF-alpha production. We investigated whether TLRs participate in the host response to Cryptococcus neoformans glucuronoxylomannan (GXM), the major capsular polysaccharide of this fungus. Chinese hamster ovary fibroblasts transfected with human TLR2, TLR4, and/or CD14 bound fluorescently labeled GXM. The transfected Chinese hamster ovary cells were challenged with GXM, and activation of an NF-kappa B-dependent reporter construct was evaluated. Activation was observed in cells transfected with both CD14 and TLR4. GXM also stimulated nuclear NF-kappa B translocation in PBMC and RAW 264.7 cells. However, stimulation of these cells with GXM resulted in neither TNF-alpha secretion nor activation of the extracellular signal-regulated kinase 1/2, p38, and stress-activated protein kinase/c-Jun N-terminal kinase mitogen-activated protein kinase pathways. These findings suggest that TLRs, in conjunction with CD14, function as pattern recognition receptors for GXM. Furthermore, whereas GXM stimulates cells to translocate NF-kappa B to the nucleus, it does not induce activation of mitogen-activated protein kinase pathways or release of TNF-alpha. Taken together, these observations suggest a novel scenario whereby GXM stimulates cells via CD14 and TLR4, resulting in an incomplete activation of pathways necessary for TNF-alpha production.