[Birth cohort studies in China: a review]

With longer than 100-year experience of development, methods used on birth cohort study have been viewed as having important roles in exploring the probable effects of health and environment exposure both prior to and during the pregnancy in the life circle as infants, children, adolescents, adults, and the elderly. However in China, birth cohort studies started late but with rapid development. Recently, some well-known methods on birth cohort studies were established in mainland China, Hong Kong and Taiwan area. This paper presented an overall review on the progress about birth cohort studies and their prospects, in China.

Patients' perceptions of day surgery: a survey study in China surgery

OBJECTIVE

To investigate patients' perceptions of day surgery, specifically their convenience; social, functional and economic values; risk perceptions; and patient satisfaction.

DESIGN

Cross-sectional questionnaire survey.

SETTING

West China Hospital in Chengdu City, China.

PARTICIPANTS

All the day-surgery patients admitted to the Centre for Day Surgery in December 2011.

MAIN OUTCOME MEASURES

Demographic profiles, each patient's value and risk perceptions about day surgery, as well as overall satisfaction with day surgery.

RESULTS

Convenience value and social value were emphasised by 87% and 60% of the 153 valid respondents, respectively. Comparatively speaking, functional and economic value were respectively chosen by 50% and 43% of the respondents, while 75% worried about postoperative complications and adverse events, only 53% and 27% worried about rehabilitation knowledge and psychological risks, respectively. More than 95% of the respondents were satisfied with the clinic service and staff attitudes, hospital surgery environment, operating skills and results, but fewer (84%) were satisfied with the communication processes surrounding day surgery.

CONCLUSION

Patients exhibited high acceptance and satisfaction regarding day surgery. The convenience experienced by patients and their families is the main perceived value of day surgery. Nevertheless, during the recovery process patients are concerned about possible adverse events, treatment of postoperative complications, and lack of information. These aspects of care delivery warrant improvement through redesign of the day surgery service.

Analysis of polyethylene-glycol-polylactide nano-dimension artificial red blood cells in maintaining systemic hemoglobin levels and prevention of methemoglobin formation

We have recently reported our study on novel nano-dimension red blood cell (rbc) substitute based on ultrathin PEG-PLA membrane nanocapsules (80-150 nanometer diameter) containing hemoglobin (Hb) and enzymes. These have a markedly increased the circulation half-times as compared to our earlier PLA membrane nanocapsules. In the present study to be reported here, instead of looking at this from a pharmacodynamic point of view, we design the Hb nanocapsules from the point of view of transfusion medicine. For instance, the maximal levels of systemic non-red blood cell (rbc) Hb that can be attained after one infusion of 30% blood volume of 10 gm/dl Hb in the form of different types of PEG-PLA Hb nanocapsules or polyHb. Also the length of time one infusion can maintain a given systemic non-rbc hemoglobin Hb level. Of the two types of polyhemoglobins similar to those in clinical trials but prepared in this laboratory, the maximal levels of Hb reached were 3.35 gm/dl and 3.10 gm/dl respectively. The times for the hemoglobin level to fall to 1.67 gm/dl were 14 hours and 10. hours respectively, corresponding to 24 hours and 17 hours in human. The best PEG-PLA Hb nanocapsules are prepared using a combination of the following 4 factors: use of polymerized Hb, the use of higher M.W. PLA, the use of higher concentrations of PEG-PLA and the crosslinking of the newly formed PEG-PLA Hb nanocapsules. With this, the maximal non-rbc systemic Hb reached was 3.66 gm/dl and the time to reach 1.67 gm/dl was 24.2 hours, or 41.5 hours in human if extrapolated using the results obtained with polyHb in rats.

Conserved synteny between the Fugu and human PTEN locus and the evolutionary conservation of vertebrate PTEN function

Mutations of PTEN, which encodes a protein-tyrosine and lipid phosphatase, are prevalent in a variety of human cancers. The human genome 'draft' sequence still lacks organization and much of the PTEN and adjacent loci remain undefined. The pufferfish, Fugu rubripes, by virtue of having a compact genome represents an excellent template for rapid vertebrate gene discovery. Sequencing of 56 kb from the Fugu pten (fpten) locus identified four complete genes and one partial gene homologous to human genes. Genes neighboring fpten include a PAPS synthase (fpapss2) differentially expressed between non-metastatic/metastatic human carcinoma cell lines, an inositol phosphatase (fminpp1) and an omega class glutathione-S-transferase (fgsto). We have determined the order of human BAC clones at the hPTEN locus and that the locus contains hPAPSS2 and hMINPP1 genes oriented as are their Fugu orthologs. Although the human genes span 500 kb, the Fugu genes lie within only 22 kb due to the compressed intronic and intergenic regions that typify this genome. Interestingly, and providing striking evidence of regulatory element conservation between widely divergent vertebrate species, the compact 2.1 kb fpten promoter is active in human cells. Also, like hPTEN, fpten has a growth and tumor suppressor activity in human glioblastoma cells, demonstrating conservation of protein function.

Two future generations of blood substitutes based on polyhemoglobin-SOD-catalase and nanoencapsulation

This paper discusses our research on two new generation blood substitutes. One is based on the crosslinking of hemoglobin, superoxide dismutase(SOD) and catalase (CAT) to form polyhemoglobin-SOD-CAT. This is being investigated for use in conditions with potential problems related to ischemia-reperfusion injuries as in severe hemorrhagic shock, stroke and other conditions. The second one is based on biodegradable polymeric nanocapsules containing hemoglobin and enzymes. In this form, the hemoglobin and enzymes are separated from the external environment. Furthermore, modifications of the polymeric membrane can result in increase in circulation time.

Sustained drug release characteristics of biodegradable composite poly(d,l)lactic acid-poly(l)lactic acid microcapsules containing ciprofloxacin

Ciprofloxacin polylactic microcapsules were prepared by the phase separation process. Two types of polylactic acid, poly(d,l)lactic acid and poly(l)lactic acid were combined as membrane materials to prevent the aggregation which happened frequently in the phase separation process. The polymer compositions of the microcapsules can influence the release rate of Ciprofloxacin. The optimal release rate of the drug can be obtained by modifying microcapsule compositions. Poly(d,l)lactic acid is superior in slowing the rate of drug release than poly(l)lactic acid. However, poly(l)lactic acid is necessary in the preparation of the microcapsules to prevent aggregation.

Biodegradable polylactic acid nanocapsules containing ciprofloxacin: preparation and characterization

Nanocapsules have been studied as carriers to deliver different types of drugs into macrophages. Many studies have shown that the nanocapsules can enhance the biological response of the drugs. In this study, we prepared ciprofloxacin nanocapsules with polylactic acid. The ciprofloxacin is an antibacterial agent. The ciprofloxacin nanocapsules prepared have a means diameter of 168 nm. In phosphate buffer at pH 7.4, high encapsulation rate was obtained. The nanocapsules with high encapsulation rate can also be made from ciprofloxacin base.

Insulin secretagogues activate the secretory granule receptor-like protein-tyrosine phosphatase IAR

To investigate the potential role of protein-tyrosine phosphatases (PTPs) in regulated secretion, cellular PTP activity was measured in pancreatic beta cell lines after exposure to insulin secretagogues. A peak of elevated PTP activity was detected in whole cell lysates after 15-20 min of treatment of the cells with high KCl, glucose, or TPA, which did not appear upon treatment with control compounds. Neither was it detected in cells that do not undergo regulated secretion. The PTP activation was transient, SDS-resistant, and localized to the cytoskeleton fraction of cells. The cytoskeletal localization of IAR, a receptor-like PTP associated with secretory granules of neuroendocrine cells, suggested the possibility that IAR is the secretagogue-activated PTP. The transient expression of human IAR in betaTC3 and HIT-T15 beta cells, followed by treatment with secretagogues or control compounds and immunoprecipitation of human IAR, showed that immunoprecipitates from the secretagogue-treated cells contained an elevated PTP activity. The secretagogue-induced activation of IAR had identical kinetics to that of the endogenous PTP. Although ectopic IAR was present in membrane and cytoskeletal fractions from the cells, only the cytoskeleton-associated IAR could be activated. Thus IAR represents the endogenous secretagogue-responsive PTP, or at least a component of it, and is one of the few receptor-like PTPs for which enzymatic activation has been demonstrated. Insulin secretion is detected prior to IAR activation, suggesting that IAR is not required for immediate secretion but likely plays a role in events downstream of insulin secretion or in another pathway related to the specialized function of secretory cells.

Antibodies to the protein tyrosine phosphatases IAR and IA-2 are associated with progression to insulin-dependent diabetes (IDDM) in first-degree relatives at-risk for IDDM

Insulin-dependent diabetes mellitus (IDDM) is preceded by the presence of antibodies against islet proteins including a protein tyrosine phosphatase (PTP) designated IA-2. Recently, we cloned a novel PTP named IAR which shares 43% sequence identity with IA-2 and is recognised by antibodies from a majority of patients with IDDM. The aim of the present study was to determine whether IAR antibodies (IAR Ab) or IA-2 antibodies (IA-2 Ab) are associated with progression to IDDM in first-degree relatives "at-risk" for IDDM (operationally defined as those with islet cell antibodies [ICA] > or = 20JDFU or insulin autoantibodies [IAA] > or = 100 nU/ml), and to examine combinations of IAR Ab and IA-2 Ab in these subjects. The sensitivity and specificity of these antibodies were also examined in patients with recent-onset IDDM. Using Cox's Proportional Hazards Model, the number of siblings with IDDM was associated with progression to IDDM in "at-risk" relatives, but other covariables (age, sex, number of affected offspring or parents) were not significantly associated. Using number of affected siblings as a covariable, both IAR and IA-2 antibodies were significantly associated with progression to IDDM (p < 0.005). Combinations of both antibodies, however, did not result in a significantly stronger association with progression to IDDM. The threshold of positivity for IAR Ab (0.5 units) and IA-2 Ab (3.0 units) assays was adjusted to give the same specificity (97.9%) for each assay in 144 healthy control subjects, to allow standardised comparisons. Levels of IAR Ab and IA-2 Ab were strongly correlated in 53 recent-onset IDDM patients (r = 0.70, p < 0.0001) but 11.3% had IAR Ab in the absence of IA-2 Ab and 16.9% had IA-2 Ab in the absence of IAR Ab. The sensitivity for IDDM (defined as the proportion of IDDM patients positive) was 56.6% for IAR Ab and 62.3% for IA-2 Ab. We conclude that there is considerable overlap in IA-2 Ab and IAR Ab positivity, although either antibody can occur independently in IDDM patients. Both IAR Ab and IA-2 antibodies are associated with progression to IDDM in first-degree relatives at-risk of IDDM, but the use of IAR and IA-2 antibodies in combination are not significantly more strongly associated with progression than single antibodies. IAR Ab may play an important role in the prediction of IDDM.

Preparation of polylactic acid microcapsules containing ciprofloxacin

Microcapsules have been used as drug delivery systems in the pharmaceutical field for sustained or controlled release of drug, and for artificial cells and organs. Biodegradable polymers, especially polylactic acid, have been widely used in this field. In this study, an attempt was made to develop a new method to prepare polylactic acid microcapsules for drug delivery. The biodegradable polylactic acid microcapsules were made by the phase separation process: two types of polylactic acid, poly[(D,L)lactic acid] and poly[(L)lactic acid] were combined as the membrane material. Because of the difference of the crystal properties of the two polymers, the aggregation which happens frequently in the phase separation process was prevented. As a model drug, Ciprofloxacin was encapsulated in the polylactic acid microcapsules.

Oligodendrocyte population dynamics and the role of PDGF in vivo

Oligodendrocyte progenitors originate near the floor plate of the spinal cord, then proliferate and migrate throughout the cord before giving rise to oligodendrocytes. Progenitor cell proliferation stops before birth because the cell cycle slows down, linked to an increase in differentiation and death. Experiments with transgenic mice show that platelet-derived growth factor (PDGF) drives progenitor cell division and suggest that slowing of and exit from the cycle reflects a decline in PDGF signaling. Overexpressing PDGF induces hyperproliferation of progenitor cells and excessive, ectopic production of oligodendrocytes. However, the superfluous oligodendrocytes die at an immature stage of differentiation, leaving a normal complement of myelin-forming cells. Therefore, cell survival controls override proliferation controls for determining the final number and distribution of mature oligodendrocytes.

Identification of a domain on the beta-subunit of the rod cGMP-gated cation channel that mediates inhibition by calcium-calmodulin

The cGMP-gated cation channel mediating phototransduction in retinal rods has recently been shown to be inhibited by calcium-calmodulin, through direct binding of the latter to the beta-subunit of the heterotetrameric channel complex. Here, we report the characterization of this inhibition and the identification of a domain crucial for this modulation. Heterologous expression of the alpha- and beta-subunits of the human rod channel in HEK 293 cells produced a cGMP-gated current that was highly sensitive to calcium-calmodulin, with half-maximal inhibition at approximately 4 nM. In biochemical and electrophysiological experiments on deletion mutants of the beta-subunit, we have identified a region on its cytoplasmic N terminus that binds calmodulin and is necessary for the calmodulin-mediated inhibition of the channel. However, in gel shift assays and fluorescence emission experiments, peptides derived from this region indicated a low calmodulin affinity, with dissociation constants of approximately 3-10 microM. On the C terminus, a region was also found to bind calmodulin, but it was likewise of low affinity, and its deletion did not abolish the calmodulin-mediated inhibition. We suggest that although the identified region on the N terminus of the beta-subunit is crucial for the calmodulin effect, other regions are likely to be involved as well. In this respect, the rod channel appears to differ from the olfactory cyclic nucleotide-gated channel, which is also modulated by calcium-calmodulin.

Identification of components of a phosphoinositide signaling pathway in retinal rod outer segments

Phototransduction in retinal rods involves a G protein-coupled signaling cascade that leads to cGMP hydrolysis and the closure of cGMP-gated cation channels that are open in darkness, producing a membrane hyperpolarization as the light response. For many years there have also been reports of the presence of a phosphoinositide pathway in the rod outer segment, though its functions and the molecular identities of its components are still unclear. Using immunocytochemistry with antibodies against various phosphoinositide-specific phospholipase C (PLC) isozymes (beta1-4, gamma1-2, and delta1-2), we have found PLCbeta4-like immunoreactivity in rod outer segments. Similar experiments with antibodies against the alpha-subunits of the G(q) family of G proteins, which are known to activate PLCbeta4, have also demonstrated G(alpha11)-like immunoreactivity in this location. Immunoblots of total proteins from whole retina or partially purified rod outer segments with anti-PLCbeta4 and anti-G(alpha11) antibodies gave, respectively, a single protein band of the expected molecular mass, suggesting specific labelings. The retinal locations of the two proteins were also supported by in situ hybridization experiments on mouse retina with probes specific for the corresponding mouse genes. These two proteins, or immunologically identical isoforms, therefore likely mediate the phosphoinositide signaling pathway in the rod outer segment. At present, G(alpha11) or a G(alpha11)-like protein represents the only G protein besides transducin (which mediates phototransduction) identified so far in the rod outer segment. Although absent in the outer segment layer, other PLC isoforms as well as G(alpha q) (another G(q) family member), are present elsewhere in the retina.

Origins of spinal cord oligodendrocytes: possible developmental and evolutionary relationships with motor neurons

Spinal cord oligodendrocytes develop from migratory glial progenitor cells that are generated by a small subset of neuroepithelial cells in the ventral part of the neural tube. Specification of these neuroepithelial oligodendrocyte precursors, in common with other ventral cells such as motor neurons, depends on morphogenetic signals from the notochord and/or floor plate. The ventrally derived signals can be mimicked in vitro by purified Sonic hedgehog (Shh) protein. Oligodendrocytes and motor neurons are induced over the same range of concentrations of Shh, consistent with the idea that Shh might specify a common precursor of motor neurons and oligodendrocytes. A lineage relationship between motor neurons and oligodendrocytes has previously been suggested by clonal analysis in the embryonic chick spinal cord. We propose a lineage diagram that connects oligodendrocytes and motor neurons and that takes into account the fact that motor neurons and oligodendrocyte precursors are generated at different times during development. Oligodendrocytes might originally have evolved to ensheath motor axons and facilitate a rapid escape response. If so, oligodendrocyte ontogeny and phylogeny might share a common basis.

Cloning and characterization of islet cell antigen-related protein-tyrosine phosphatase (PTP), a novel receptor-like PTP and autoantigen in insulin-dependent diabetes

Cloning of the cDNA encoding a novel human protein- tyrosine phosphatase (PTP) called islet cell antigen-related PTP (IAR) predicts a receptor-like molecule with an extracellular domain of 614 amino acids containing a hydrophobic signal peptide, one potential N-glycosylation site, and an RGDS peptide which is a possible adhesive recognition sequence. The 376-amino acid intracellular region contains a single catalytic domain. Recombinant IAR polypeptide has phosphatase activity. Northern blot analysis shows tissue-specific expression of two IAR transcripts of 5.5 and 3. 7 kilobases, which are most abundant in brain and pancreas. The IAR PTP is homologous in its intracellular region to IA-2, a putative PTP that is an insulin-dependent diabetes mellitus (IDDM) autoantigen. IAR is also reactive with IDDM patient sera. IAR and IA-2 may distinguish different populations of IDDM autoantibodies since they identify overlapping but nonidentical sets of IDDM patients. Thus IAR is likely to be an islet cell antigen useful in the preclinical screening of individuals for risk of IDDM.

Molecular cloning, functional expression and chromosomal localization of a human homolog of the cyclic nucleotide-gated ion channel of retinal cone photoreceptors

We have cloned from human retina a cyclic nucleotide-gated (CNG) ion channel that is distinct from the one found in rod photoreceptors. This channel protein is highly homologous to the CNG channel that recently has been cloned from bovine testis and kidney and has been shown to be present in retinal cone photoreceptors. When expressed in human embryonic kidney cells, the protein forms functional ion channels with properties broadly similar to those described for the cloned bovine channel. The gene for this channel resides on chromosome 2.

Determination of neuroepithelial cell fate: induction of the oligodendrocyte lineage by ventral midline cells and sonic hedgehog

Near the floor plate of the embryonic neural tube there is a group of neuroepithelial precursor cells that are specialized for production of the oligodendrocyte lineage. We performed experiments to test whether specification of these neuroepithelial oligodendrocyte precursors, like other ventral neural cell types, depends on signals from the notochord and/or floor plate. We analyzed heterozygous Danforth's short tail (Sd/+) mutant mice, which lack a notochord and floor plate in caudal regions of the neural tube, and found that oligodendrocyte precursors did not appear at the ventricular surface where there was no floor plate. Moreover, oligodendrocytes did not develop in explant cultures of Sd/+ spinal cord in the absence of a floor plate. When a second notochord was grafted into an ectopic position dorsolateral to the endogenous notochord of a chicken embryo, an additional floor plate was induced along with an ectopic focus of oligodendrocyte precursors at the ventricular surface. Oligodendrocytes developed in explants of intermediate neural tube only when they were cocultured with fragments of notochord or in the presence of purified Sonic hedgehog (Shh) protein. Thus, signals from the notochord/floor plate, possibly involving Shh, are necessary and sufficient to induce the development of ventrally derived oligodendroglia. These signals appear to act by specifying the future fate(s) of neuroepithelial cells at the ventricular surface rather than by influencing the proliferation or differentiation of prespecified progenitor cells in the parenchyma of the cord.

Submicron polymer membrane hemoglobin nanocapsules as potential blood substitutes: preparation and characterization

Biodegradable polymer membrane nanocapsules containing hemoglobin have been prepared with phase separation and polymer precipitation methods. We have used different polymers including polylactic acid and polyisobutyl-cyanoacrylate. The mean diameter of the hemoglobin nanocapsules can be as low as 0.07 mu and up to 0.39 mu dependent on the method of preparation. The concentration of the hemoglobin in the suspension can be up to 11 gm/dl, as compared to 15 gm/dl in whole blood. The viscosity of the preparation is slightly lower than that of human blood. In vitro tests show that P50 of these nanocapsules containing bovine hemoglobin is identical to free bovine hemoglobin solution. The surface of the nanocapsules can be modified for example with polyethylene glycol(PEG) or with PEG 2000 PE. Preliminary in vivo tests show that surface modified nanocapsules containing hemoglobin can survive longer in the circulation.

Complete structures of three rice sucrose synthase isogenes and differential regulation of their expressions

By cloning and sequencing cDNA and genomic DNA and transcription initiation site mapping, the total structures including at least 1 kb of putative regulatory sequences upstream of the transcription initiation sites of three genes encoding rice sucrose synthase isoprotomers were either newly established or amended. The third type of SS gene, RSus3, has not been found in other plants. The structures of the three genes and the gene products were compared and their evolutionary sequence was proposed. Specific probes for the three SS mRNA's were developed and used for analyzing their steady state levels at different organs and under some physiological stress conditions. It appears that RSus2 is a house-keeping gene, RSus3 is highly specific to the grain, and the expression of RSus1 shows a tendency to complement that of RSus3. A possible cause of the presence of the third rice SS gene was discussed. We also reported a novel method to synthesize single-stranded DNA for S1 mapping of a transcription initiation site associated with extended secondary structures.

Embryonic expression of myelin genes: evidence for a focal source of oligodendrocyte precursors in the ventricular zone of the neural tube

2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNP) is an abundant protein of myelinating oligodendrocytes. We report that one of the alternatively spliced CNP mRNAs is also expressed in cultured oligodendrocyte progenitor cells. In situ hybridization revealed a thin longitudinal column of CNP-positive cells in the ventral ventricular zone of the embryonic day 14 rat spinal cord, coincident in time and space with cells that express the platelet-derived growth factor alpha receptor, another putative marker of the oligodendrocyte lineage. These data support the hypothesis that the oligodendrocyte lineage originates at a discrete location in the ventral ventricular zone of the embryonic day 14 rat spinal cord. We further report that transcripts encoding the myelin proteolipid protein (PLP/DM-20) are expressed in an unidentified population of neural progenitors in the ventricular zone abutting the floor plate. Our results support the idea that the ventricular zone is a mosaic of specialized progenitor cells.

Anti-metastatic activity of MDP-L-alanyl-cholesterol incorporated into various types of nanocapsules

A lipophilic immunomodulator (MTP-Chol) was included in nanocapsules prepared from different polymers and the anti-metastatic effects of the resulting drug delivery systems were evaluated in a murine model of liver metastases. Loaded nanocapsules were effective if they were given 2 days before tumor inoculation. Neither the nature of the polymer nor the total dose of immunomodulator affected the antimetastatic capacity. However, enhanced anti-metastatic activity was obtained when indomethacin nanocapsules were associated with MTP-Chol nanocapsules. These results show that nanocapsules containing an immunomodulator possess anti-metastatic activity, but only when given as a prophylactic treatment; this would correspond, in the clinic, to patients undergoing surgery for a primary tumor and at risk of developing liver metastases.

Submicron biodegradable polymer membrane hemoglobin nanocapsules as potential blood substitutes: a preliminary report

We used biodegradable polymers like polylactic acid, poly-isobutylcyanoacrylate and others to prepare nanocapsules containing hemoglobin. We prepared the optimal mean diameters of between 0.08 to 0.12 micron (80-120 nm). They are spherical and homogeneous. The membrane thickness is 0.005-0.015 micron (5-15nm). With different formulation, the hemoglobin contents in the particles may be varied from 30-45%. Phospholipid is not required in bovine hemoglobin. It is required for human hemoglobin in order to retain cofactors required for optimal P50. The P50 of the biodegradable polymer membrane containing bovine hemoglobin was between 27-29 mmHg. This is the same P50 as bovine hemoglobin used in the preparation. Thus the procedure of preparation did not damage hemoglobin.

Presence of three rice sucrose synthase genes as revealed by cloning and sequencing of cDNA

By sequencing cDNA clones, we have concluded that three distinct sucrose genes are expressed in rice (Oryza sativa cv. Tainong 67). When the amino acid sequences deduced from these cDNAs as well as those of known sucrose synthase are compared, the highest divergence is found in the C-termini. The most suitable DNA sequences for use as specific for the mRNA derived from these genes have been suggested.

Anti-metastatic activity in vivo of MDP-L-alanyl-cholesterol (MTP-Chol) entrapped in nanocapsules

A lipophilic muramylpeptide (MTP-Chol), capable of rendering macrophages cytostatic towards tumour cells, was encapsulated within polyisobutylcyanoacrylate nanocapsules and administered to mice carrying an experimental model of liver metastasis. Treatment by intravenous injections twice a week beginning before the establishment of metastases significantly reduced the number of liver colonies. Treatment started later was less effective. The dose of MTP-Chol in each injection, and the tumour burden in the mice did not change the percentage inhibition of metastases significantly. Anti-metastatic activity was also observed after administering nanocapsules containing MTP-Chol by the oral route.

Intervention trial with selenium for the prevention of lung cancer among tin miners in Yunnan, China. A pilot study

This pilot study evaluated the feasibility and effectiveness of conducting a double-blind clinical trial for the prevention of lung cancer with selenium (Se) in Yunnan Tin Corporation, the People's Republic of China, where the incidence rates of lung cancer are extraordinarily high among the miners. Forty healthy miners were randomized to either 300 micrograms of Se in high Se malt cakes or an identical placebo of malt cakes daily for one year. Subjects consumed their usual daily diet. The low Se concentrations in plasma (0.05 +/- 0.008 microgram/mL) and hair (0.442 +/- 0.085 microgram/g) reflected their low dietary Se intake in the control subjects. In Se-supplemented group, the Se status was increased by 178% for serum and 194.8% for hair. The serum GSHpx activity was increased by 155.7%, whereas the lipid peroxide level was reduced by 74.5% compared to the placebo. The results of UDS assay indicated that the lymphocyte DNA damage induced by ultraviolet irradiation and carcinogen 3,4-benzpyrene could be protected by Se supplementation. Se-supplementation did not affect the liver function test (SGPT), as well as the concentrations of hemoglobin, albumin, and cholesterol. Thus, daily intake of 300 micrograms Se in form of Se-malt as a chemopreventive measure is safe and effective to humans with low Se status.

Chemoprevention trial of human hepatitis with selenium supplementation in China

A three-year study has been conducted for prevention of infectious hepatitis with supplementation of table salt fortified with 15 ppm anhydrous sodium selenite to the general population of 20,847 persons in a township M.Z. at Qidong County, Jiangsu Province, China. The results showed that the incidence of virus hepatitis infection in the test township was significantly lower than that of controls provided with normal table salt. The incidence rate of infectious hepatitis in the treated township M.Z. was 1.20 and 4.52 per 1,000, whereas the average incidence in the 6 surrounding control townships was 2.96 and 10.48 per 1,000 in 1986 and 1987, respectively. The incidence of hepatitis B surface antigen (HBsAg+) was 13.2% vs 19.23% for males and 10.42% vs 12.24% for females in the supplemented vs nonsupplemented neighboring township, respectively. Epidemiological studies have demonstrated that a low grain Se content is associated with a high regional incidence of hepatitis B virus infections.