First measurement of the neutron beta asymmetry with ultracold neutrons

We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer. We determine a value for the beta-asymmetry parameter A_{0}=-0.1138+/-0.0046+/-0.0021.

Cross-sectional comparison of physical activity and inactivity patterns in Chinese and Filipino youth

BACKGROUND

To compare and contrast youth physical activity (PA) and inactivity patterns in two developing Asian countries: the Philippines and China.

METHODS

Comparative analysis of 1997-1999 Cebu Longitudinal Health and Nutrition Survey and the 1997 China Health and Nutrition Survey, large-scale surveys that included questions on type, frequency and duration of: commuting mode to school, sports/exercise in and outside of school, select sedentary activities and chores.

RESULTS

Filipino data included 760 males and 872 females aged 14-16 years. The comparable Chinese sample consisted of 202 males and 197 females. Active commuting is proportionately high in both countries (70-71% in the Philippines vs. 77-90% in China), although commuting by bicycling is rare in the Philippines (<1%) vs. China ( approximately 35%). Patterns of school sport/exercise participation differ between countries by gender; more Filipino males report school sport/exercise than females (63 vs. 49%) vs. China, where more females participate than males (75 vs. 69%). Sport/exercise outside of school is proportionately low (6-12%) for youth from both countries with a single exception: 74% of Filipino males participate in extra-curricular sport/exercise. Although a higher percentage of Filipino youth report watching television >4 h/day (<10%) vs. Chinese youth (<1%), both are lower than comparable US reports.

CONCLUSION

In the Philippines, continued modernization augurs a decrease in local primary PA sources (chores and active commuting). In China, where youth already are not expected to perform chores, shifts to more passive commuting modes (i.e. increased motorized transportation) are anticipated.

Studies on the encapsulation of oxymatrine into liposomes by ethanol injection and pH gradient method

Oxymatrine is the major active alkaloid constituent extracted from traditional Chinese herb medicine Sophora flavescens Ait (Kushen) and Sophora alopecuroides (Kudouzi). In recent years, oxymatrine had been found to posses remarkable anti-hepatic activity and has been used for treating hepatitis B in clinical therapy in China. In this study, we attempted to entrap oxymatrine into liposomes to facilitate the delivery of oxymatrine to the liver and enhance the therapeutic efficiency for hepatitis. Preformulation investigation was performed to obtain the drug physicochemical properties such as solubility, pKa, and logP for rational liposomes preparation design. Liposomes were prepared with soybean lecithin by ethanol injection and pH gradient loading methods. At the same time the factors affecting the entrapment efficiencies were investigated and compared. Ethanol injection method yielded liposomes with entrapment efficiency less than 20%. The lipid composition and aqueous medium had some effects on entrapment efficiency. However, liposomes could be produced with entrapment efficiency above 50% by pH gradient method. The internal pH buffer capacity, the lipid composition, and drug-to-lipid ratio greatly influenced the entrapment efficiency, while the incubation temperature had almost no effect on entrapment efficiency in the active loading procedure.

Measuring the full economic costs of diet, physical activity and obesity-related chronic diseases

Most studies that have focused on the costs of obesity have ignored the direct effects of obesity-related patterns of diet and physical activity. This study reviews the full effects of each component--poor dietary and physical activity patterns and obesity--on morbidity, mortality and productivity. The direct healthcare costs are based on a review of the effects of these factors on key diseases and the related medical care costs of each disease. The indirect costs on reduced disability, mortality and sickness during the period of active labour force participation prior to retirement are also examined. A case study is prepared for China to provide some guidance in the utilization of this review for economic analysis of obesity. The case study shows that the indirect costs are often far more important than the direct medical care costs. The Chinese case study found that the indirect effects of obesity and obesity-related dietary and physical activity patterns range between 3.58% and 8.73% of gross national product (GNP) in 2000 and 2025 respectively.

Trends in the distribution of body mass index among Chinese adults, aged 20-45 years (1989-2000)

OBJECTIVE

To describe body mass index (BMI, in kg/m(2)) distribution patterns and trends among Chinese adults, aged 20-45 years (1989-2000).

DESIGN

A descriptive, population-based study of BMI change.

SETTING

Chinese provinces (eight in 1989 and 1997; nine in 2000), representative of the household-based surveys (the China Health and Nutrition Survey, 1989-2000) using multistage, random cluster sampling, supplemented with annual household consumption survey data of the State Statistical Bureau (SSB).

SUBJECTS

A total of 4527, 4507 and 4046 adults, aged 20-45 years, in 1989, 1997 and 2000, respectively.

MEASUREMENTS

BMI (underweight: BMI<18.5 kg/m(2) and overweight: BMI>/=25 kg/m(2)). Percentile curves for BMI in 1989 and 2000 were constructed by gender and age using the LMS (lambda, mu, sigma) method.

RESULTS

Compared with 1989, the 2000 BMI distribution curves flattened at higher levels of BMI (men and women). There was a 13.7% increase in the proportion of men and a 7.9% increase of women who were overweight or obese with a resulting greater change in the annualized prevalence rate for men. This increase in the prevalence of overweight and obesity was far greater than the decrease (2.1% for men; 2.2% for women) in that of underweight. Age-gender-specific percentile curves showed BMI increases mainly among women, aged 35-45 years, and among men at all age groups.

CONCLUSIONS

Chinese BMI dynamics show much greater rates of change among men, aged 20-45 years, than among women, with the increase among women concentrated between ages 35 and 45 years. These changes portend large shifts in other diet-related non-communicable diseases in China over the following decades. Controlling the increasing trends of BMI, especially in men, is an important public health problem facing China.

Enhanced oral bioavailability of breviscapine after encapsulation in a liposomal formulation

This report firstly describes the pharmacokinetic study of liposomal breviscapine (LB) after oral administration in rats. The mean Cmax and AUC(0-->t) of LB were 3.3 and 3.1-fold higher than those of breviscapine solution (BS). The oral absorption of breviscapine was significantly increased after encapsulation in the liposomal formulation.

Histological measurement of human retinal thickness

The fresh eye balls from the accidental death adults were placed on low temperature slicer to cut into slices. The fresh sections was subjected to the direct measurement of retinal thickness by using CMIAS multi-function real color pathologic imaging analysis system. The results showed that in the total of 6 eye balls measured, the mean retinal thickness was 310.92 +/- 34.14 microns. It was concluded that it was simple and had high confidence for the fresh eye ball low temperature frozen sections to directly measure the retinal thickness, which provided a histological method for the measurement of retinal thickness and the reference of retinal thickness of Chinese adults.

Physical activity and inactivity in Chinese school-aged youth: the China Health and Nutrition Survey

OBJECTIVE

To describe physical activity (PA) and inactivity levels and patterns in Chinese school children (aged 6-18 y).

DESIGN

PA and inactivity were assessed in a youth cohort enrolled in the China Health and Nutrition Survey (CHNS) in 1997.

SUBJECTS

A total of 1423 males (11.5+/-3.2 y) and 1252 females (11.5+/-3.3 y).

MEASUREMENTS

PA and inactivity were assessed by self-reported usual activity (questionnaire). Children under 10 y were assisted by parents.

RESULTS

Approximately 84% of Chinese youth actively commute to school for a median of 100-150 min/week. A total of 72% engage in in-school moderate/vigorous (MOD/VIG) PA for a median of 90-110 min/week. Relatively few children ( approximately 8%) participate in any MOD/VIG PA outside of school. A total of 72% engage in study-related activities outside of school for a median of 420 min/week. Only 8% of Chinese school children, regardless of gender, watch television > or =2 h/day; less than 1% watch > or =4 h/day. Chores related to housework are not a part of life for Chinese school children; fewer than 20% performed these tasks.

CONCLUSION

Chinese youth are unique compared to those in other developing countries because they do not perform household chores. Instead, they are under pressure to achieve scholastically. Participation in MOD/VIG PA outside of school is almost nonexistent. Current television watching habits are relatively low compared to developed countries and walking/biking is a common form of commuting. The descriptive analysis herein represents the foundation upon which future longitudinal studies of PA in this population will be based.

[Use of transcranial Doppler in monitoring cerebral blood flow velocity during peri-operation]

Transcranial Doppler was used to monitor 45 patients' middle cerebral artery blood flow velocity during anesthesia and cardiopulmonary bypass. The result was that the change in middle cerebral artery blood flow velocity was in correspondence with cerebral blood flow. This paper suggests that transcranial Doppler is a simple and practical instrument for monitoring cerebral blood flow.

Synthesis and reactivity of the monocarbon molybdenacarborane anion [1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)](-)

The reagent Li[7-NHBu(t)()-nido-7-CB(10)H(12)] reacts with [Mo(CO)(6)] in NCMe at reflux temperatures, followed by addition of [N(PPh(3))(2)]Cl, to give [N(PPh(3))(2)][1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (1). The tungsten (2) and chromium (3) analogues were similarly obtained, but the latter is unstable and was isolated in low yield. An X-ray diffraction study of 2 confirmed that the exo-polyhedral NHBu(t) group forms a bridge between the cage-carbon atom and the tungsten. For 1, this intramolecular donor bond is lifted on protonation in the presence of donor molecules L (CO, PPh(3), PMe(3), PEt(3), PMe(2)Ph) when zwitterionic complexes [1-NH(2)Bu(t)()-2,2,2-(CO)(3)-2-L-closo-2,1-MoCB(10)H(10)] (4) are formed. In contrast, protonation with HCl gives a salt [N(PPh(3))(2)][1-NH(2)Bu(t)()-2,2,2-(CO)(3)-2-Cl-closo-2,1-MoCB(10)H(10)] (5). Complex 1 in CH(2)Cl(2) with CNBu(t) is oxidized by iodine, affording [1,2-mu-NHBu(t)()-2,2,2-(CNBu(t)())(3)-2-I-closo-2,1-MoCB(10)H(10)] (6a). Treatment of 1 with [CuCl(PPh(3))](4) in the presence of Tl[PF(6)] yields the bimetallic compound [exo-[Cu(PPh(3))]-1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (8), whereas reaction with [AuCl(PPh(3))] and Tl[PF(6)] affords a mixture of [1,2-mu-NHBu(t)-2-[Au(PPh(3))]-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (9) and [Au(PPh(3))(2)][2,2'-mu-Au-[1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(1)(0)H(10)](2)] (10a). In solution, 9 disproportionates, giving 10a. The [N(PPh(3))(2)](+) salt (10b) is readily prepared by treating 1 with [AuCl(THT)] (THT = tetrahydrothiophene) and Tl[PF(6)], and its structure was determined by X-ray diffraction.

Vaccinia virus telomeres: interaction with the viral I1, I6, and K4 proteins

The 192-kb linear DNA genome of vaccinia virus has covalently closed hairpin termini that are extremely AT rich and contain 12 extrahelical bases. Vaccinia virus telomeres have previously been implicated in the initiation of viral genome replication; therefore, we sought to determine whether the telomeres form specific protein-DNA complexes. Using an electrophoretic mobility shift assay, we found that extracts prepared from virions and from the cytoplasm of infected cells contain telomere binding activity. Four shifted complexes were detected using hairpin probes representing the viral termini, two of which represent an interaction with the "flip" isoform and two with the "flop" isoform. All of the specificity for protein binding lies within the terminal 65-bp hairpin sequence. Viral hairpins lacking extrahelical bases cannot form the shifted complexes, suggesting that DNA structure is crucial for complex formation. Using an affinity purification protocol, we purified the proteins responsible for hairpin-protein complex formation. The vaccinia virus I1 protein was identified as being necessary and sufficient for the formation of the upper doublet of shifted complexes, and the vaccinia virus I6 protein was shown to form the lower doublet of shifted complexes. Competition and challenge experiments confirmed that the previously uncharacterized I6 protein binds tightly and with great specificity to the hairpin form of the viral telomeric sequence. Incubation of viral hairpins with extracts from infected cells also generates a smaller DNA fragment that is likely to reflect specific nicking at the apex of the hairpin; we show that the vaccinia virus K4 protein is necessary and sufficient for this reaction. We hypothesize that these telomere binding proteins may play a role in the initiation of vaccinia virus genome replication and/or genome encapsidation.

[Distributions of body mass index of Chinese adults]

Based on the Third China National Nutrition Survey conducted in 1992, the distribution of body mass index (BMI) in 44,485 adults aged 20-60 y was analyzed, and the cutoff points of BMI for overweight and obesity were also explored. The results showed that the BMI of Chinese adults was in logarithmic normal distribution. The average BMI of this population was 22.1 +/- 3.1. The 50th, 85th and 95th percentiles of BMI were 21.6, 24.9 and 27.4 kg/m2 respectively. The 85th percentile of BMI was much closer to the BMI cutoff points for overweight recommended by WHO, but the 95th percentile was much lower than WHO's cutoff points for obesity. The distribution of BMI based on age, gender and urban/rural areas was different and with statistical significance. It is considered that age and gender should be taken into account while setting up BMI cutoff points for the overweight and obesity of a population, as well as considering the relationships among BMI and morbidity and mortality, body fat composition, and some blood biochemical indexes.

The neuroprotective agent ebselen modifies NMDA receptor function via the redox modulatory site

Ebselen is a seleno-organic compound currently in clinical trials for the treatment of ischemic stroke and subarachnoid hemorrhage. Its putative mode of action as a neuroprotectant is via cyclical reduction and oxidation reactions, in a manner akin to glutathione peroxidase. For this reason, we have investigated the effects of ebselen on the redox-sensitive NMDA receptor. We have found that ebselen readily reversed dithiothreitol (DTT) potentiation of NMDA-mediated currents in cultured neurons and in Chinese hamster ovary (CHO) cells expressing wild-type NMDA NR1/NR2B receptors. In contrast, ebselen was unable to modulate NMDA-induced currents in neurons previously exposed to the thiol oxidant 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), or in CHO cells expressing a mutant receptor lacking the NR1 redox modulatory site, suggesting that ebselen oxidizes the NMDA receptor via this site. In addition, ebselen was substantially less effective in modifying NMDA responses in neurons exposed to alkylating agent N-ethylmaleimide (NEM) following DTT treatment. Ebselen also reversed DTT block of carbachol-mediated currents in Cos-7 cells expressing the alpha(2)beta delta epsilon subunits of the acetylcholine receptor, an additional redox-sensitive ion channel. Ebselen was observed to significantly increase cell viability following a 30-min NMDA exposure in cultured neurons. In contrast, other more typical antioxidant compounds did not afford neuroprotection in a similar paradigm. We conclude that ebselen may be neuroprotective in part due to its actions as a modulator of the NMDA receptor redox modulatory site.

[Transition of dietary pattern in China]

The implications of dietary transition in China during the past 50 years were investigated. Data were collected from the representative national surveys, China Health and Nutrition Survey (1989-1997), China National Nutrition Survey (1982 and 1992), the Annual Household Consumption Surveys of the State Statistic Bureau and the Annual Death Report of China. In the early part of the major economic transformation, cereal intake increased before 1985 and decreased thereafter. There was also a long-term reduction of vegetable consumption, which has stabilized now. Intakes of animal foods increased slowly before 1979 and more quickly after the economic reforms occurred. The total energy intake has reduced, as energy expenditure has, large changes in the composition of energy have occurred. The proportion of energy from fat increased quickly and reached 27.3% in average and 32.8% in urban residents in 1997. More than one third of all Chinese adults and 58.4% of adults in urban areas consuming over 30% of their energy from fat. These changes resulted in rapid increases the prevalence of overweight and obesity and dietary-related chronic non-communicable diseases in urban residents. The traditional Chinese diet is shifting towards a diet with high fat, high energy density and low dietary fiber. The Chinese diets have entered into a new stage of transition.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

Structural and mechanistic investigation of 3-deoxy-D-manno-octulosonate-8-phosphate synthase by solid-state REDOR NMR

15N¿(31)P¿ REDOR NMR experiments were applied to lyophilized binary complexes of 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS), with each of its natural substrates, phosphoenolpyruvate (PEP) and arabinose-5-phsophate (A5P), and with a mechanism-based inhibitor (K(i) = 0.4 microM), directly characterizing the active site basic residues involved in the binding of their carboxylate and phosphate moieties. KDO8PS was labeled uniformly with (15)N or [eta-(15)N(2)]Arg, and the ligands were selectively labeled with (13)C and (15)N. The NMR data established that PEP is bound by KDO8PS via a preserved set of structurally rigid and chemically unique Arg and Lys residues, with 5 A (upper limit) between epsilon-(15)N of this Lys and (31)P of PEP. A5P is bound in its cyclic forms to KDO8PS via a different set of Lys and Arg residues. The two sets arise from adjacent subsites that are capable of independent and sufficiently strong binding. The inhibitor is best characterized as an A5P-based substrate analogue inhibitor of KDO8PS. Five mutants in which highly conserved arginines were replaced with alanines were prepared and kinetically characterized. Our solid-state NMR observations complement the crystallographic structure of KDO8PS, and in combination with the mutagenesis results enable tentative assignment of the NMR-identified active site residues. Lys-138 and Arg-168 located at the most recessed part of the active site cavity are the chemically distinct and structurally rigid residues that bind PEP phosphate; R168A resulted in 0.1% of wild-type activity. Arg-63, exposed at the opening of the active site barrel, is the flexible residue with a generic chemical shift that binds A5P; R63A resulted in complete deactivation. The mechanistic implications of our results are discussed.

NMDA and glutamate evoke excitotoxicity at distinct cellular locations in rat cortical neurons in vitro

The development of cortical neurons in vivo and in vitro is accompanied by alterations in NMDA receptor subunit expression and concomitant modifications in the pharmacological profile of NMDA-activated ionic currents. For example, we observed that with decreasing NR2B/NR2A subunit expression ratio, the block of NMDA receptor-mediated whole-cell responses by the NR2B-selective antagonist haloperidol was also decreased. In mature cultures (>22 d in vitro), however, NMDA responses obtained from excised nucleated macropatches, which comprised a large portion of the soma, remained strongly antagonized by haloperidol. These results suggest that in more mature neurons NR1/NR2B receptors appear to be preferentially expressed in the cell body. As predicted from the whole-cell recording pharmacological profile, NMDA-induced toxicity was largely unaffected by haloperidol in mature cultures. However, haloperidol effectively blocked glutamate toxicity in the same cultures, suggesting that the neurotoxic actions of this amino acid were mostly due to the activation of somatic NMDA receptors. In experiments in which the potency of glutamate toxicity was increased by the transport inhibitor l-trans-pyrrolidine-2,4-dicarboxylic acid, the neuroprotective effects of haloperidol were significantly diminished. This was likely because of the fact that glutamate, now toxic at much lower concentrations, was able to reach and activate dendritic receptors under these conditions. These results strongly argue that exogenous glutamate and NMDA normally induce excitotoxicity at distinct cellular locations in mature mixed neuronal cultures and that NR1/NR2B receptors remain an important component in the expression of glutamate, but not NMDA-induced excitotoxicity.

Role of tumor necrosis factor-alpha in neuronal and glial apoptosis after spinal cord injury

We investigated the role of tumor necrosis factor (TNF)-alpha in the onset of neuronal and glial apoptosis after traumatic spinal cord crush injury in rats. A few TUNEL-positive cells were first observed within and surrounding the lesion area 4 h after injury, with the largest number observed 24-48 h after injury. Double-labeling of cells using cell type-specific markers revealed that TUNEL-positive cells were either neurons or oligodendrocytes. One hour after injury, an intense immunoreactivity to TNF-alpha was observed in neurons and glial cells in the lesion area, but also seen in cells several mm from the lesion site rostrally and caudally. The level of nitric oxide (NO) also significantly increased in the spinal cord 4 h after injury. The injection of a neutralizing antibody against TNF-alpha into the lesion site several min after injury significantly reduced both the level of NO observed 4 h thereafter as well as the number of apoptotic cells observed 24 h after spinal cord trauma. An inhibitor of nitric oxide synthase (NOS), N(G)-monomethyl-l-arginine acetate (l-NMMA), also reduced the number of apoptotic cells. This reduction of apoptotic cells was associated with a decrease in DNA laddering on agarose gel electrophoresis. These results suggest that: (i) TNF-alpha may function as an external signal initiating apoptosis in neurons and oligodendrocytes after spinal cord injury; and (ii) TNF-alpha-initiated apoptosis may be mediated in part by NO as produced by a NOS expressed in response to TNF-alpha.

[Pressure influence on mRNA expression and protein synthesis of inducible nitric oxide synthetase in bovine trabecular meshwork cell]

OBJECTIVE

To investigate the inducible nitric oxide synthetase (iNOS) mRNA expression and protein synthesis in bovine trabecular meshwork cell and discuss the possible effects of nitric oxide (NO) in the development of glaucoma.

METHODS

20 mm Hg, 40 mm Hg, 60 mm Hg and 80 mm Hg pressure were respectively added on cultured trabecular cells of new born bovine. No pressure group was set as the control. The changes of iNOS mRNA and protein in trabecular meshwork cells under different pressures were demonstrated qualitatively and quantitatively by in situ hybridization and nicotinamide-adenine dinucleotide phosphate diaphorase (NADPH-d) histochemical assay.

RESULTS

The expression of iNOS mRNA and its protein synthesis became higher and higher as the pressure was increased. There was weak iNOS mRNA expression in the control and 20 mm Hg groups, and no significant difference between them. 40 mm Hg and 60 mm Hg groups had a statistical difference from the control group. And 80 mm Hg group had a very significant difference from the control group. There was no difference between 40 mm Hg and 60 mm Hg groups, but they had significant difference from 80 mm Hg group. NADPH-d histochemical assay showed almost the same results except that there was significant difference between 40 mm Hg and 60 mm Hg groups.

CONCLUSIONS

Pressure can evoke the expression of iNOS mRNA, and the nitric oxide thus produced can be one of the causes of trabecular meshwork destruction, that may induce or aggravate glaucoma.

The inhibitory effects of IFN alpha-2b on EGFR expression and growth of cultured subconjunctival fibroblasts

To investigate to what extent the growth of cultured subconjunctival fibroblasts was regulated by epidermal growth factor receptor (EGFR), we observed the expression of EGFR inhibited by interferon alpha-2b (IFN alpha-2b) and determined the growth of cultured subconjunctival fibroblasts by immunohistochemical and MTT methods. The linear relationships between the concentration of IFN alpha-2b and EGFR expression or growth were y = 1252.7-554.61 lgx (r = -0.98, P < 0.01), y = 0.523-0.0421 lgx (r = -0.93, P < 0.05) respectively. The concentration of IFN alpha-2b at doubled IC50 to EGFR (6.55 x 10(3) IU/ml) only inhibited the cell growth by 25.13%. The results suggested that the growth of subconjunctival fibroblasts may be controlled by many other growth factors because it was only partially inhibited by decreasing EGFR expression.

Rapid increase in immunoreactivity to GFAP in astrocytes in vitro induced by acidic pH is mediated by calcium influx and calpain I

In higher vertebrates, reactive gliosis resulting from injury to the central nervous system (CNS) is characterized by a rapid increase in immunoreactivity (IR) to glial fibrillary acidic protein (GFAP). Little is known about the extracellular signals that initiate the increase in GFAP-IR following CNS injury. We demonstrated recently [T.H. Oh, G.J. Markelonis, J.R. Von Visger, B. Baik, M.T. Shipley, Acidic pH rapidly increases immunoreactivity of glial fibrillary acidic protein in cultured astrocytes, Glia 13 (1995) 319-322] that a rapid increase in GFAP-IR can be evoked in mature astrocyte cultures by exposing the cells to an acidic medium. We investigated the intracellular pathway(s) involved in initiating increased GFAP-IR, a hallmark of reactive astrocytes. The increase in GFAP-IR produced by exposure to acidic medium was blocked by pretreatment with nickel ions, by such blockers of L-type calcium channels as nifedipine, verapamil and diltiazem, by calpain inhibitor I, or by the intracellular calcium chelator, BAPTA-AM. At physiological pH, treatment with the calcium ionophore, A23187, resulted in increased GFAP-IR which could be blocked by pretreatment with calpain inhibitor I. Astrocytes exposed to low pH exhibited a marked increase in a GFAP fragment with a molecular weight of 48 kDa. In astrocytes exposed to acidic medium, alpha-fodrin, a selective endogenous substrate of calpain, was also found to be hydrolyzed producing fragments with molecular weights of 120-150 kDa. As anticipated, pretreatment with calpain inhibitor I prevented the proteolytic degradation of both GFAP and alpha-fodrin in these samples. These results suggest that the initial increase in GFAP-IR after CNS injury appears to be linked to Ca(++) influx, and is mediated further by a proteolytic process that seemingly involves the activation of the calcium-dependent protease, calpain I.

Immunogenicity of porcine transmissible gastroenteritis virus spike protein expressed in plants

Transgenic plants expressing recombinant proteins from pathogenic microorganisms provide an inexpensive edible vaccine for induction of local immunity. Three transgenic plant lines were generated expressing the spike (S) protein of transmissible gastroenteritis virus (TGEV), a protein crucial for establishing mucosal immunity. All three of them were driven by a strong plant promoter. One construct contained the 3.7 kb 5' end of the native S gene sequence. In the second construct part of the S gene, from nucleotide 49 to 1785, was modified for optimal plant recognition and was fused to a plant signal peptide coding sequence. The third construct contained the D epitope-coding region of the S gene, from nucleotide 1201 to 1591, which was fused to the alfalfa beta-amylase gene. The S gene products were detected by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Antigens from all three transgenic plant lines induced TGEV-specific immune responses in pigs as determined by virus neutralization and ELISA, and the resultant antibody titers for all three constructs were similar.

[Measurement of human retinal thickness at posterior pole with retinal thickness analyzer in normal and glaucomatous eyes]

OBJECTIVE

To determine the diagnostic value of retinal thickness analyzer (RTA) in glaucoma.

METHODS

RTA was used to measure the retinal thickness at the posterior pole in 77 normal persons (116 eyes) at various ages and 22 cases (35 eyes) with glaucoma. The obtained images were processed by a computer to yield the retinal thickness value and the thickness map at this location, and the data were analyzed with SAS software package.

RESULTS

The mean retina thickness of normal subjects was (171.83 +/- 18.50) microm with no significant difference among the various age groups (F = 2.68, P > 0.05), and very significant between the sexes; the thickest retina was at the location between macula and optic nerve head, and the macular nasal retina is 11.7% thicker than its temporal side. The upper and lower retinas of the fovea were basically symmetrical. The retinal thickness in glaucoma patients showed diffuse or local thinning, and there was a very significant difference between the normal group and the glaucomatous group in retina thickness (F = 11.98, P = 0.0001). The sensitivity rate for detecting glaucoma with RTA was up to 80.8%, and specificity to 78.5%.

CONCLUSIONS

The thickness map for the retina at posterior pole across the macula in normal subjects is "horse shoe" shaped, that is well matched with the topography of retinal ganglion cell and the retinal nerve fibers in human retina. Diffuse or local thinning of retinal thickness in glaucomatous patients, which is in agreement with the corresponding visual field defect, and the sensitivity of RTA is higher than that of perimeter. The RTA examination is easy to operate, has high reproducibility, no invasion, therefore it is an ideal method to measure the human retinal thickness in vivo.

Establishment of labeling primer reverse transcription in situ polymerase chain reaction and detection of hepatitis C virus in liver tissues

OBJECTIVE

To establish bio-11-photosoralen (BP) labeling primer reverse transcription in situ polymerase chain reaction (PCR), and to detect the location and distribution of hepatitis C virus in 30 cases liver tissues embedded with paraffin.

METHODS

BPs were labeled in tymidine (T) position under ultraviolet lamp. The method was compared with indirect RT-in situ PCR and in situ hybridization for detecting hepatitis C virus (HCV) RNA.

RESULTS

Serum HCV PCR and southern blot showed that BP labeling psimer PCR was possible, and had a good specificity. The HCV positive rate was 53% (16/30) by indirect in situ PCR, 50% (15/30) positive specimens were found by BP labeling primer in situ PCR. Statistical analysis revealed P > or = 0.05 and the two methods had no dominant differences. Meanwhile, only 23% (7/30) positive signals were seen by in situ hybridization, which was lower than two in situ PCR(P < or = 0.05). HCV was mainly located in hepatic-plasmas, and positive signals were found in monocytes and cholangiolar epithelia.

CONCLUSIONS

Both indirect in situ PCR and BP labeling in situ PCR have good sensitivity and specificity for detecting HCV RNA of liver tissues. HCV RNA is located in hepatocytes, monocytes and cholangiolar epithelia.

Current methods for estimating dietary iron bioavailability do not work in China

Three current equations for estimating iron bioavailability were evaluated, and adjustments were proposed that would allow us to most effectively study iron bioavailability in China. Dietary intake data were obtained from 24-h dietary recalls taken over three consecutive days as part of the third Chinese National Nutrition Survey. Hemoglobin status was measured for 42,606 Chinese adults aged 18-60 y. The mean iron intake was 24.4 mg per capita per day, which was 177% of the Chinese RDA (209% of U.S. RDA). About 18% of the sample was classified as being anemic, indicating a large iron deficiency anemia and iron bioavailability problem in China. A number of methods proposed by World Health Organization and U.S. scholars were examined for adjusting iron bioavailability. Even the methods that consider several iron enhancers and inhibitors did not work adequately for the Chinese diet. The statistical assessment of the fit between iron bioavailability and hemoglobin status provided direction for adjusting the best of these predictive equations. We propose a new predictive approach for iron bioavailability which is more predictive of Chinese iron status. Consideration of additional dietary elements such as rice and bean consumption patterns are important. Our findings provide insight into additional factors which may influence iron bioavailability as well as possible improved methods for estimating the combined effect of multiple dietary factors on iron bioavailability, particularly in a vegetarian diet.

Preliminary studies on the application of retinal thickness analyzer in the diagnosis of glaucoma

The patients with glaucoma underwent the examination of retinal thickness analyzer (RTA) to explore the diagnostic value of RTA in glaucoma. The retina of 6 mm x 6 mm size (approximately 20 degrees, centered on the macula) at the posterior pole was scanned by using RTA to obtain the images in 35 eyes of 22 patients with glaucoma. The images were processed by using SAS software package. The retinal thickness in the patients with glaucoma showed diffuse or local thinning. Twenty-seven eyes was definitely diagnosed as having glaucoma. There was a very significant difference in retinal thickness measurements by RTA between normal group and glaucomatous group (P = 0.0012). Except the measurements at the detected point 6 having no difference, the measurements at the detected point 3 showed a significant difference and the remaining 7 detected points presented a very significant difference between the two groups. Of the detected 9 points, the changes at the points 4, 8, and 9 were the most obvious. The discrete analysis was performed on the glaucomatous patients by a discriminant function established through the data at the detected points 4, 8 and 9 and the accurate estimate rate for the diagnosis of glaucoma was up to 80.77%. The measurements of RTA examination was consistent with the results of the vision field test. It was suggested that diffuse or local thinning of retinal thickness exists in the patients with glaucoma. The temporal inferior arcuate fibers and the papillomacular bundle between the macular and optic nerve heads showed a serious damage. The sensitivity of RTA examination was higher than visual field test.

Towards the development of novel antibiotics: synthesis and evaluation of a mechanism-based inhibitor of Kdo8P synthase

The design and two synthetic pathways to aminophosphonate 4 which mimics the ionic and steric properties of putative oxocarbenium intermediate 3 in the Kdo8P synthase-catalyzed reaction are reported. It was found that 4 is a slow-binding, most potent inhibitor of the enzyme yet tested, with a Ki value of 0.4 microM.

Regulated expression of a highly conserved regulatory gene cluster is necessary for controlling photosynthesis gene expression in response to anaerobiosis in Rhodobacter capsulatus

We utilized primer extension analysis to demonstrate that the divergently transcribed regB and senC-regA-hvrA transcripts contain stable 5' ends 43 nucleotides apart within the regB-senC intergenic region. DNA sequence analysis indicates that this region contains two divergent promoters with overlapping sigma70 type -35 and -10 promoter recognition sequences. In vivo analysis of expression patterns of regB::lacZ and senC-regA-hvrA::lacZ reporter gene fusions demonstrates that the regB and senC-regA-hvrA transcripts are both negatively regulated by the phosphorylated form of the global response regulator RegA. DNase I protection assays with a constitutively active variant of RegA indicate that RegA binds between regB and senC overlapping -10 and -35 promoter recognition sequences. Two mutations were also isolated in a regB-deficient background that increased expression of the senC-regA-hvrA operon 10- and 5-fold, respectively. As a consequence of increased RegA expression, these mutants exhibited elevated aerobic and anaerobic photosynthesis (puf) gene expression, even in the absence of the sensor kinase RegB. These results indicate that autoregulation by RegA is a factor contributing to the maintenance of an optimal low level of RegA expression that allows responsiveness to activation by phosphorylation.

In vitro activation and repression of photosynthesis gene transcription in Rhodobacter capsulatus

It has been known for over half a century that anoxygenic photosynthetic bacteria maximally synthesize their photosystems in the absence of oxygen. During the last decade, it has become clear that this regulation is largely at the transcriptional level, with photosynthesis genes expressed only under anaerobic conditions. We describe here in vitro reconstitution of activation and repression of three photosynthesis promoters, bch (bacteriochlorophyll biosynthesis), puc (light-harvesting II apoproteins) and puf (reaction centre and light-harvesting I apoproteins) using purified transcription factors and RNA polymerase from Rhodobacter capsulatus. Previous genetic results have indicated that each of these three promoters is differentially regulated by three key regulators: CrtJ acting as a repressor of bch and puc and the two-component regulators RegA/RegB, which are activators of puc and puf. These regulators are distinct from those that mediate oxygen control in enteric bacteria. Our in vitro studies show that these purified regulators directly control the expression of the housekeeping RNA polymerase at these promoters. High-level basal expression of the bch promoter is shown to be repressed by CrtJ. The puc promoter is activated by the RegB-phosphorylated RegA protein and additionally repressed by CrtJ. At the puc promoter, CrtJ effectively competes for promoter binding with RegA, while at the bch promoter, repression appears to be by competition for the RNA polymerase binding site. In contrast to what has been suggested previously, the RegA-activated puf promoter is demonstrated as being recognized by the housekeeping RNA polymerase. We also discuss evidence that RegA approximately P activation of the puc and puf promoters involves recruitment of RNA polymerase by different modes of protein-protein interaction.

Autophosphorylation, phosphotransfer, and DNA-binding properties of the RegB/RegA two-component regulatory system in Rhodobacter capsulatus

In the purple, photosynthetic bacterium, Rhodobacter capsulatus, the RegB/RegA two-component system is required for activation of several anaerobic processes, such as synthesis of the photosynthetic apparatus and assimilation of CO2 and N2. It is believed that RegB is an integral membrane histidine kinase that monitors the external environment. Under anaerobic growth conditions, it transduces a signal through phosphorylation of the response regulator, RegA, which then induces target gene expression. We used an in vitro assay to characterize the phosphorylation of wild-type RegA and a mutant variant (RegA*) that is responsible for abnormally high photosynthesis gene expression under both aerobic and anaerobic growth conditions. Phosphorylation assays indicate that phosphorylated RegA* (RegA* approximately P) is much more stable than RegA approximately P, indicating that it may be locked in a conformation that is resistant to dephosphorylation. DNase I footprint assays also indicate that unphosphorylated RegA* has a much higher affinity for specific DNA binding sites than the wild-type protein. Phosphorylation of RegA* increases DNA binding 2. 5-fold, whereas phosphorylation of RegA increases DNA binding more than 16-fold. Collectively, these results support the hypothesis that RegA* is a constitutively active variant that does not require phosphorylation to assume a structural conformation required to bind DNA.

Calcium influx and activation of calpain I mediate acute reactive gliosis in injured spinal cord

Buffering extracellular pH at the site of a spinal cord crush-injury may stimulate axonal regeneration in rats (1; Guth et al., Exp. Neurol. 88: 44-55, 1985). We demonstrated in cultured astrocytes that acidic pH initiates a rapid increase in immunoreactivity for GFAP (GFAP-IR), a hallmark of reactive gliosis (2; Oh et al., Glia 13: 319-322, 1995). We extended these studies by investigating the effects of certain treatments on reactive gliosis developing in situ in a rat spinal cord injury model. A significant reactive gliosis was observed within 2 days of cord lesion in untreated crush or vehicle-treated, crush control animals as evidenced by increased GFAP-IR and hypertrophy of astrocytes. By contrast, infusion of Pipes buffer (pH 7.4) into the lesion site significantly reduced this increase. The increased GFAP-IR appeared to be linked to Ca2+ influx since infusion of a blocker of L-type calcium channels, nifedipine, reduced the ensuing reactive gliosis significantly. While Ca2+ modulates many signaling pathways within cells, its effect on reactive gliosis appeared to result from an activation of calpain I. Calpain inhibitor I, a selective inhibitor of mu-calpain, also significantly reduced reactive gliosis. However, calpain inhibitor II, a close structural analog which blocks m-calpain, had no salutary effect. We suggest, therefore, that the initial reactive gliosis seen in vivo may result from the activation of a neutral, Ca2+-dependent protease, calpain I, through calcium influx.

A clinical trial on yu cong tang in treatment of senile dementia

Yu Cong Tang ([symbol: see text]), a TCM decoction, was used to treat senile dementia. It has the action of invigorating the spleen, reinforcing the kidney, nourishing yin, strengthening yang, improving blood circulation, dredging the channels, removing phlegm and restoring consciousness. CT, EEG, REG, Hb, PaO2, Tch, TG and 17-OHCS were tested, showing significant differences (P < 0.05 or < 0.01) before and after the treatment. Remarkable improvement was found in clinical symptoms, and the effective rate was 94.1%. Significant differences were found between the TCM and western medicine (WM) groups in symptom improvement (P < 0.05-0.01) and therapeutic results (P < 0.001).

[Long-term follow-up of combined therapy with large-dose zinc sulfate and low-dose penicillamine in children with hepatolenticular degeneration]

OBJECTIVE

To summarize the long-term effect of combined treatment with large-dose zinc sulfate and low-dose penicillamine in children with hepatolenticular degeneration (HLD).

METHODS

The patients who had symptoms were treated with large-dose zinc sulfate (100-150mg, <6yr; 150-200mg, 6-8yr; 200-300mg, 9-10yr; 300mg,>10yr; 3 times a day) in addition to low-dose penicillamine(8-10mg/kg/d) at the beginning of treatment. Zinc sulfate alone was given to the presymptomatic patients and it was used as maintenance therapy when clinical improvement was obtained. 31 children were followed up for 4-11 years.

RESULTS

In 3 presymptomatic patients, no clinical abnormalities were found. Among 28 patients with symptoms, 23 patients (82%) had their symptoms and signs subsided or much improved, 2 patients(7%) remained unchanged, and 3(11%) died. Blood concentrations of copper were persistently lower than normal. Urine copper excretion of 24 hours was significantly lower than that before the combined therapy in all patients, and it became normal in 5 cases(16%) after 6 months of treatment, and in 26 cases(84%) after 1-2 years of treatment. Higher blood concentrations of zinc were found in 20 cases(65%), and higher urine zinc excretion was noted in 25 cases(81%) once or more times during the therapy.

CONCLUSION

Combined therapy of large-dose zinc sulfate and low-dose penicillamine is an effective, safe and cheap treatment for children with HLD.

[A study of interferon alpha-2b as an accessory drug after glaucoma filtration surgery]

OBJECTIVE

To elucidate the inhibitory action of interferon alpha-2b (IFN alpha-2b) on the cicatrization under conjunctiva and the best way to use it after glaucoma filtration surgery.

METHODS

Immunohistochemical PAP method and image biological system 2000 (IBAS 2000) were utilized to quantitatively analyze the inhibitory effect of IFN alpha-2b on the expression of epidermal growth factor receptor (EGFR) of cultured calf fibroblasts; the effects of IFN alpha-2b on collagen contents in suture-caused cicatrization under conjunctiva and changes of aqueous humor protein after trabeculectomy performed on rabbits have also been observed.

RESULTS

IFN alpha-2b reduced the expression of EGFR of cultured bovine fibroblasts at a dose-dependent manner. The relationship between the EGFR and the dosage of IFN alpha-2b is Y = 2953.8 - 554.5 lgx (r = -0.98, P < 0.01). With 4.67 x 10(-5) micromol/L IFN alpha-2b not only reduced about 50% of the collagen in suture-caused cicatrization, but also significantly decreased the protein concentration of aqueous humour 3 and 72 hours after trabeculectomy.

CONCLUSION

It is promising that IFN alpha-2b can be used after glaucoma filtration surgery to reduce excessive cicatrization with many advantages compared with antimetabolites.

Detection of GB virus C/hepatitis G virus RNA by reverse-transcription polymerase chain reaction

Recently, a novel RNA virus, designated GB virus C or hepatitis G virus (GBV-C/HGV) has been identified which may possibly be associated with human hepatitis. In this study, the nucleotide sequences of the partial nonstructural 5 (NS5) gene of GBV-C/HGV derived from sera of eight Chinese patients were determined. The overall degree of nucleotide conservation and the existence of regional highly conserved sequences make this part of the genome suitable for the development of diagnostic reagents. On the basis of sequence analysis, two sets of oligonucleotide primers were designed to establish a nested polymerase chain reaction (PCR) for detection of GBV-C/HGV RNA. The efficacy of three PCR methods (first, one stage PCR, second, nested PCR with primers from the NS5 region designed according to the prototype sequence and the third, our newly developed PCR) was compared in 133 Chinese patients with liver disease. The positive rates of these three methods were 8.3%, 11.3% and 18.0% respectively. The specificity of our PCR detecting system was verified by sequencing and restriction fragment length polymorphism (RFLP). In conclusion, because of the heterogeneity and geographic distribution character of GBV-C/HGV, it is necessary to assess the sequence variation among Chinese patients infected with GBV-C/HGV. This may allow to identify GBV-C/HGV RNA with high sensitivity and specificity.

Measurement of retinal thickness in normal subjects with retinal thickness analyzer

The retinal thickness at posterior pole of normal subjects was measured by using retinal thickness analyzer (RTA) to determine the values of retinal thickness and to establish map of retinal thickness in normal subjects. The retina of 6 mm x 6 mm in size (approximately 20 degrees, centered on the macula) at the posterior pole was scanned by using RTA to obtain images of 116 normal eyes of 77 cases of various age group. The images were processed by a computer to obtain the retinal thickness values and the thickness map of this location. The data were analyzed with SAS software package. The mean retinal thickness was 171.77 +/- 26.13 microns with no significant difference among the various age groups (P > 0.05). The thickness maps of the retina of 6 mm x 6 mm size at the posterior pole around the macula rendered a "U"-shaped pattern, extending from the disc to the superior and inferior of the fovea. The retina was found to be thin at temporal side of the fovea, with the thinnest area being at the macula central fovea. The U-shaped pattern of the retinal thickness maps was well in agreement with the topography of the ganglion cells and the retinal nerve fibers in human retina. The measurement of the retinal thickness by RTA reflected the changes in the layers of ganglion cells and the retinal nerve fiber. Each scanning session of RTA examination can yield multiple optical cross-section images of the retina and obtain retinal thickness maps of posterior pole of living eyes.

DNA binding characteristics of RegA. A constitutively active anaerobic activator of photosynthesis gene expression in Rhodobacter capsulatus

In the purple non-sulfur bacterium Rhodobacter capsulatus, RegA and RegB comprise a two-component regulatory system that is required for maximal anaerobic transcription of key photosynthesis genes. RegB is a sensor kinase that uses ATP to phosphorylate its cognate response regulator, RegA. The mechanism under which RegA approximately P influences transcription of target genes has been unclear given that past attempts to demonstrate DNA binding activity by isolated RegA have failed. This led to a model invoking a role for RegA approximately P as an intermediate in a more complex multicomponent phosphoryl transfer cascade. In the present study, we describe the isolation of a mutant version of RegA (RegA*) which promotes high level expression of photosynthesis genes independent of RegB. DNase I footprint analyses show that purified RegA* binds to the promoters of the puf and puc operons at locations that are consistent with RegA functioning as a transcriptional activator for these operons. We conclude that RegA functions, like most members of the response regulator family, as a DNA-binding protein that directly affects the expression of its target genes.

[An experimental study on mechanism of intraocular pressure decline after allogeneic transplantation of trabecular meshwork]

OBJECTIVE

To study the mechanism of intraocular pressure (IOP) decline after allogeneic transplantation of trabecular meshwork (TM) in primate experimental glaucoma.

METHODS

The experimental open-angle glaucoma models were created in 8 rhesus monkey eyes by repeated pangoniophotocoagulation on functional TM using argon laser. After 2, 3, 5 months respectively, avidin-gold or self-erythrocytes, which acted as tracers of the aqueous humor outflow, were perfused into the anterior chamber under normal pressure and volume conditions. 30 minutes later, 2.5% glutaraldehyde was perfused into the anterior chamber under the same conditions. Allograft TMs and photocoagulated area (serving as the control) were observed by light, transmission, scanning electron microscopy and ultrahistochemistry study.

RESULTS

The IOP of 5 eyes of 6 experimental eyes became normal. A blood reflux into Schlemm's canal was seen by gonioscopy in 4 eyes. The surface of TMs from graft showed the normal uveal TM cords and intertrabecular spaces. Erythrocytes were found in the intertrabecular spaces and Schlemm's canal. Avidin-gold and vacuolar containing gold were observed in the cells of TM and Schlemm's canal. The TMs of photocoagulated area appeared to be fewer and narrower intertrabecular spaces. The uveal cords of this zone were confused. The content of acid mucopolysaccharides in the grafts was closer to normal than that in the photocoagulated areas.

CONCLUSION

TM of allogeneic transplantation not only can survive but also function as an aqueous humor outflow pathway. We consider that this operative procedure can be used for treatment of some cases with glaucoma cautiously.

Genetic variability and characterization of non-structural region 5 of hepatitis C virus genome from Chinese patients

Sequence variation in the putative non-structural region 5b (NS5b) of hepatitis C virus (HCV) was analyzed in China. Complementary DNA fragments from sera of 49 Chinese patients were amplified by polymerase chain reaction (PCR) and the products were cloned and sequenced. Based on the comparison in NS5b of 33 clones of genotype 1b and 16 clones of genotype 2a, Chinese isolates of HCV belong to the same subtype as HCV-J, and HC-J6 from Japan. There does exist, however, some heterogeneity in the primary structure of the nucleotide acid. Higher homology was found among Chinese isolates than among Chinese isolates and Japanese isolates. Furthermore, among Chinese isolates, we found some conserved nucleotide acid positions different from those of Japanese isolates. Comparison of average homology among the 33 clones of genotype 1b and the 16 clones of genotype 2a indicated that the average homology among genotype 2a was lower than that among genotype 1b. In addition, a deletion of three nucleotide acids and a frame-shift, resulting in the introduction of an in-frame stop codon, were first observed in the NS5b region. These results indicated geographical differences in the distribution of individual HCV isolates, and the existence of a local variant in the same subtype. Our findings also suggested the need for further study on the sequence of genotype 2a, to improve diagnosis and help to advance the development of a vaccine.

[Studies on multiple infection with hepatitis B, C and G viruses]

OBJECTIVE

To study if there exists superinfection and multiple infection in the patients with hepatitis G virus (HCV) infection.

METHODS

Reverse transcription polymerase chain reaction (RT-PCR) technique in non-structural gene 3 (NS3) region of HGV was used to detect HGV RNA in serially diluted quality control sera and HGV-C reference panel of samples provided by Abbott Co. Ltd, in 90 cases with positive hepatitis C virus (HCV) RNA, and 12 blood donors with super-infection of hepatitis B virus (HBV) and hepatitis C virus (HCV).

RESULTS

Serially diluted quality control sera showed positive for HGV RNA at dilutions of 10(-1) to 10(-5), but negative at dilutions of 10(-6) to 10(-8). HGV RNA was positive in two samples of HGV-C serum provided by Abbott Co. HGV RNA was positive in eight of the 90 cases with positive HCV RNA and in four of the 12 cases with super-infection with HCV and HBV.

CONCLUSION

There are not only super-infection of HBV and HCV, but also multiple infection.

[Variation in hepatitis C virus NS 5b nucleotide sequence and its relationship with interferon treatment]

In order to investigate variation in hepatitis C virus (HCV) nonstructural 5b (NS5b) nucleotide sequence and the relationship with interferon treatment, cDNA containing in this region were obtained by reverse transcription-polymerase chain reaction from the sera of 4 HCV RNA positive asymptomatic chronic carriers and 9 chronic hepatitis C patients. The cDNA were then directly analysed by polymerase-chain-reaction-directed sequencing. Compared with three published HCV type II/1b sequences (HCV-J, HC-C2 and HCV-BDS), the homology of HCV was lower in the patients with chronic hepatitis C (93.52% +/- 2.09% average), especially in nonresponders to interferon (92.70 +/- 1.90% average), than in asymptomatic HCV carriers (95.65 +/- 2.61%). In 5 patients, HCV RNA was eliminated by interferon treatment. In the remaining 4 interferon-treated HCV survived patients there were 9-48 nucleotide substitutions in HCV mutants out of 380 nucleotides, resulting 6-20 amino acids changes out of 126 amino acids. These results suggested that NS5b region variants play an important role in maintaining persistent infection and the evolution of NS5b is associated with the effect of interferon treatment.

[Sequence analysis of 5' non-coding region of hepatitis G viruses and preliminary classification of genotypes]

For analyzing the structural characteristics of hepatitis G virus (HGV or GBV-C), 277 nucleic acids of 5' non-coding region of HGV were amplified using PCR from the sera of 2 paid donors, 2 chronic hepatitis patients and 2 patients with liver cirrohsis. The products were cloned and sequenced. The data were analyzed with the computer programs. The results indicated that the gene sequence homologies among 6 HGV isolates (G001-G006) obtained in this study were above 96.2%. The comparison of these 6 isolates and 3 foreign isolates reported previously showed that the sequence homologies were in the range from 86.9% to 91.6%. According to the variability of gene sequences, the preliminary division of genotypes of 6 Chinese HGV isolates (G001-G006) and 3 isolates reported abroad were classified into three distinct groups. The results suggest that the gene sequences of Chinese HGV isolates are highly homologous but have an obvious divergence with the foreign isolates. The 5' untranslated regions of all isolates analyzed probably contain a stable and similar secondary structure.

[Epidemiological study on human prostate cancer in Wuhan City]

In America, Canada and many European countries, prostate cancer is the most common cancer and the second leading cause of cancer death in men. In China, the morbidity rate and mortality rate of prostate cancer are unknown. Based on the reports of Wuhan cancer surveillance in 1990-1992, this study researched the epidemiological characterics of prostate cancer. The results showed that morbidity rate and mortality rate in Wuhan city are 1.37 and 0.75 per 100,000 respectively, and the standardized morbidity rate and standardized mortality rate are 1.10 and 0.66 per 100,000 respectively. They also showed that history of urinary diseases (OR = 5.42, 95% confidence interval (CI): 1.56-18.83), children number with more than 3 (OR = 2.43, 95% CI: 1.17-5.02), coitus with more than 3 times per week in youth (OR = 3.38, 95% CI: 1.51-7.58), frequent use of sexual drugs (OR = 4.12, 95% CI: 1.65-10.25) and high body mass index (OR = 2.58; 95% CI: 1.30-5.11) are identified as risk factors of prostate cancer statistically, but physical labor (OR = 0.35, 95% CI: 0.17-0.71) and age of first nocturnal emission after 18 years old (OR = 0.20, 95% CI: 0.08-0.52) are protective factors.

[Relationship between dietary nutrients intakes and human prostate cancer]

In order to study the relationship between dietary nutrients intakes and prostate cancer, 1 : 1 matched case-control study was carried out with 102 patients suffered from histologically confirmed prostate cancer and 102 healthy controls. Total calories and 11 nutrients including protein, lipid and carbohydrates were calculated based on the mean food intakes in the latest 3 days. Analyzed by matched t-test and conditional logistic regression method, the results showed that high intakes of lipid, carbohydrates, and retinol increased the risk of prostate cancer, but vitamin C and vitamin B1 decreased the risk of prostate cancer. The multivariable adjusted ORs were 1.65 (95% confident interval (CI) 1.39-1.96) for lipid, 1.22 (95% CI 1.13-1.31) for carbohydrates, 3.21 (95% CI 2.18-4.75) for retinol, 0.61 (95% CI 0.6-0.80) for vitamin C, and 0.029 (95% CI 0.009-0.09) for vitamin B1. The authors discussed the possible mechanism of dietary nutrients contributing to the risk of prostate cancer.